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v5.14.15
   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
   4 *		operating system.  INET is implemented using the  BSD Socket
   5 *		interface as the means of communication with the user level.
   6 *
   7 *		Definitions for the AF_INET socket handler.
   8 *
   9 * Version:	@(#)sock.h	1.0.4	05/13/93
  10 *
  11 * Authors:	Ross Biro
  12 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  13 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
  14 *		Florian La Roche <flla@stud.uni-sb.de>
  15 *
  16 * Fixes:
  17 *		Alan Cox	:	Volatiles in skbuff pointers. See
  18 *					skbuff comments. May be overdone,
  19 *					better to prove they can be removed
  20 *					than the reverse.
  21 *		Alan Cox	:	Added a zapped field for tcp to note
  22 *					a socket is reset and must stay shut up
  23 *		Alan Cox	:	New fields for options
  24 *	Pauline Middelink	:	identd support
  25 *		Alan Cox	:	Eliminate low level recv/recvfrom
  26 *		David S. Miller	:	New socket lookup architecture.
  27 *              Steve Whitehouse:       Default routines for sock_ops
  28 *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
  29 *              			protinfo be just a void pointer, as the
  30 *              			protocol specific parts were moved to
  31 *              			respective headers and ipv4/v6, etc now
  32 *              			use private slabcaches for its socks
  33 *              Pedro Hortas	:	New flags field for socket options
  34 */
  35#ifndef _SOCK_H
  36#define _SOCK_H
  37
  38#include <linux/hardirq.h>
  39#include <linux/kernel.h>
  40#include <linux/list.h>
  41#include <linux/list_nulls.h>
  42#include <linux/timer.h>
  43#include <linux/cache.h>
  44#include <linux/bitops.h>
  45#include <linux/lockdep.h>
  46#include <linux/netdevice.h>
  47#include <linux/skbuff.h>	/* struct sk_buff */
  48#include <linux/mm.h>
  49#include <linux/security.h>
  50#include <linux/slab.h>
  51#include <linux/uaccess.h>
  52#include <linux/page_counter.h>
  53#include <linux/memcontrol.h>
  54#include <linux/static_key.h>
  55#include <linux/sched.h>
  56#include <linux/wait.h>
  57#include <linux/cgroup-defs.h>
  58#include <linux/rbtree.h>
  59#include <linux/filter.h>
  60#include <linux/rculist_nulls.h>
  61#include <linux/poll.h>
  62#include <linux/sockptr.h>
  63#include <linux/indirect_call_wrapper.h>
  64#include <linux/atomic.h>
  65#include <linux/refcount.h>
 
  66#include <net/dst.h>
  67#include <net/checksum.h>
  68#include <net/tcp_states.h>
  69#include <linux/net_tstamp.h>
  70#include <net/l3mdev.h>
 
  71
  72/*
  73 * This structure really needs to be cleaned up.
  74 * Most of it is for TCP, and not used by any of
  75 * the other protocols.
  76 */
  77
  78/* Define this to get the SOCK_DBG debugging facility. */
  79#define SOCK_DEBUGGING
  80#ifdef SOCK_DEBUGGING
  81#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
  82					printk(KERN_DEBUG msg); } while (0)
  83#else
  84/* Validate arguments and do nothing */
  85static inline __printf(2, 3)
  86void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
  87{
  88}
  89#endif
  90
  91/* This is the per-socket lock.  The spinlock provides a synchronization
  92 * between user contexts and software interrupt processing, whereas the
  93 * mini-semaphore synchronizes multiple users amongst themselves.
  94 */
  95typedef struct {
  96	spinlock_t		slock;
  97	int			owned;
  98	wait_queue_head_t	wq;
  99	/*
 100	 * We express the mutex-alike socket_lock semantics
 101	 * to the lock validator by explicitly managing
 102	 * the slock as a lock variant (in addition to
 103	 * the slock itself):
 104	 */
 105#ifdef CONFIG_DEBUG_LOCK_ALLOC
 106	struct lockdep_map dep_map;
 107#endif
 108} socket_lock_t;
 109
 110struct sock;
 111struct proto;
 112struct net;
 113
 114typedef __u32 __bitwise __portpair;
 115typedef __u64 __bitwise __addrpair;
 116
 117/**
 118 *	struct sock_common - minimal network layer representation of sockets
 119 *	@skc_daddr: Foreign IPv4 addr
 120 *	@skc_rcv_saddr: Bound local IPv4 addr
 121 *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
 122 *	@skc_hash: hash value used with various protocol lookup tables
 123 *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
 124 *	@skc_dport: placeholder for inet_dport/tw_dport
 125 *	@skc_num: placeholder for inet_num/tw_num
 126 *	@skc_portpair: __u32 union of @skc_dport & @skc_num
 127 *	@skc_family: network address family
 128 *	@skc_state: Connection state
 129 *	@skc_reuse: %SO_REUSEADDR setting
 130 *	@skc_reuseport: %SO_REUSEPORT setting
 131 *	@skc_ipv6only: socket is IPV6 only
 132 *	@skc_net_refcnt: socket is using net ref counting
 133 *	@skc_bound_dev_if: bound device index if != 0
 134 *	@skc_bind_node: bind hash linkage for various protocol lookup tables
 135 *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
 136 *	@skc_prot: protocol handlers inside a network family
 137 *	@skc_net: reference to the network namespace of this socket
 138 *	@skc_v6_daddr: IPV6 destination address
 139 *	@skc_v6_rcv_saddr: IPV6 source address
 140 *	@skc_cookie: socket's cookie value
 141 *	@skc_node: main hash linkage for various protocol lookup tables
 142 *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
 143 *	@skc_tx_queue_mapping: tx queue number for this connection
 144 *	@skc_rx_queue_mapping: rx queue number for this connection
 145 *	@skc_flags: place holder for sk_flags
 146 *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
 147 *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
 148 *	@skc_listener: connection request listener socket (aka rsk_listener)
 149 *		[union with @skc_flags]
 150 *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
 151 *		[union with @skc_flags]
 152 *	@skc_incoming_cpu: record/match cpu processing incoming packets
 153 *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
 154 *		[union with @skc_incoming_cpu]
 155 *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
 156 *		[union with @skc_incoming_cpu]
 157 *	@skc_refcnt: reference count
 158 *
 159 *	This is the minimal network layer representation of sockets, the header
 160 *	for struct sock and struct inet_timewait_sock.
 161 */
 162struct sock_common {
 163	/* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
 164	 * address on 64bit arches : cf INET_MATCH()
 165	 */
 166	union {
 167		__addrpair	skc_addrpair;
 168		struct {
 169			__be32	skc_daddr;
 170			__be32	skc_rcv_saddr;
 171		};
 172	};
 173	union  {
 174		unsigned int	skc_hash;
 175		__u16		skc_u16hashes[2];
 176	};
 177	/* skc_dport && skc_num must be grouped as well */
 178	union {
 179		__portpair	skc_portpair;
 180		struct {
 181			__be16	skc_dport;
 182			__u16	skc_num;
 183		};
 184	};
 185
 186	unsigned short		skc_family;
 187	volatile unsigned char	skc_state;
 188	unsigned char		skc_reuse:4;
 189	unsigned char		skc_reuseport:1;
 190	unsigned char		skc_ipv6only:1;
 191	unsigned char		skc_net_refcnt:1;
 192	int			skc_bound_dev_if;
 193	union {
 194		struct hlist_node	skc_bind_node;
 195		struct hlist_node	skc_portaddr_node;
 196	};
 197	struct proto		*skc_prot;
 198	possible_net_t		skc_net;
 199
 200#if IS_ENABLED(CONFIG_IPV6)
 201	struct in6_addr		skc_v6_daddr;
 202	struct in6_addr		skc_v6_rcv_saddr;
 203#endif
 204
 205	atomic64_t		skc_cookie;
 206
 207	/* following fields are padding to force
 208	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
 209	 * assuming IPV6 is enabled. We use this padding differently
 210	 * for different kind of 'sockets'
 211	 */
 212	union {
 213		unsigned long	skc_flags;
 214		struct sock	*skc_listener; /* request_sock */
 215		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
 216	};
 217	/*
 218	 * fields between dontcopy_begin/dontcopy_end
 219	 * are not copied in sock_copy()
 220	 */
 221	/* private: */
 222	int			skc_dontcopy_begin[0];
 223	/* public: */
 224	union {
 225		struct hlist_node	skc_node;
 226		struct hlist_nulls_node skc_nulls_node;
 227	};
 228	unsigned short		skc_tx_queue_mapping;
 229#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
 230	unsigned short		skc_rx_queue_mapping;
 231#endif
 232	union {
 233		int		skc_incoming_cpu;
 234		u32		skc_rcv_wnd;
 235		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
 236	};
 237
 238	refcount_t		skc_refcnt;
 239	/* private: */
 240	int                     skc_dontcopy_end[0];
 241	union {
 242		u32		skc_rxhash;
 243		u32		skc_window_clamp;
 244		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
 245	};
 246	/* public: */
 247};
 248
 249struct bpf_local_storage;
 
 250
 251/**
 252  *	struct sock - network layer representation of sockets
 253  *	@__sk_common: shared layout with inet_timewait_sock
 254  *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
 255  *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
 256  *	@sk_lock:	synchronizer
 257  *	@sk_kern_sock: True if sock is using kernel lock classes
 258  *	@sk_rcvbuf: size of receive buffer in bytes
 259  *	@sk_wq: sock wait queue and async head
 260  *	@sk_rx_dst: receive input route used by early demux
 
 
 261  *	@sk_dst_cache: destination cache
 262  *	@sk_dst_pending_confirm: need to confirm neighbour
 263  *	@sk_policy: flow policy
 264  *	@sk_rx_skb_cache: cache copy of recently accessed RX skb
 265  *	@sk_receive_queue: incoming packets
 266  *	@sk_wmem_alloc: transmit queue bytes committed
 267  *	@sk_tsq_flags: TCP Small Queues flags
 268  *	@sk_write_queue: Packet sending queue
 269  *	@sk_omem_alloc: "o" is "option" or "other"
 270  *	@sk_wmem_queued: persistent queue size
 271  *	@sk_forward_alloc: space allocated forward
 
 272  *	@sk_napi_id: id of the last napi context to receive data for sk
 273  *	@sk_ll_usec: usecs to busypoll when there is no data
 274  *	@sk_allocation: allocation mode
 275  *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
 276  *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
 277  *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
 278  *	@sk_sndbuf: size of send buffer in bytes
 279  *	@__sk_flags_offset: empty field used to determine location of bitfield
 280  *	@sk_padding: unused element for alignment
 281  *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
 282  *	@sk_no_check_rx: allow zero checksum in RX packets
 283  *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
 284  *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
 285  *	@sk_route_forced_caps: static, forced route capabilities
 286  *		(set in tcp_init_sock())
 287  *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
 288  *	@sk_gso_max_size: Maximum GSO segment size to build
 289  *	@sk_gso_max_segs: Maximum number of GSO segments
 290  *	@sk_pacing_shift: scaling factor for TCP Small Queues
 291  *	@sk_lingertime: %SO_LINGER l_linger setting
 292  *	@sk_backlog: always used with the per-socket spinlock held
 293  *	@sk_callback_lock: used with the callbacks in the end of this struct
 294  *	@sk_error_queue: rarely used
 295  *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
 296  *			  IPV6_ADDRFORM for instance)
 297  *	@sk_err: last error
 298  *	@sk_err_soft: errors that don't cause failure but are the cause of a
 299  *		      persistent failure not just 'timed out'
 300  *	@sk_drops: raw/udp drops counter
 301  *	@sk_ack_backlog: current listen backlog
 302  *	@sk_max_ack_backlog: listen backlog set in listen()
 303  *	@sk_uid: user id of owner
 304  *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
 305  *	@sk_busy_poll_budget: napi processing budget when busypolling
 306  *	@sk_priority: %SO_PRIORITY setting
 307  *	@sk_type: socket type (%SOCK_STREAM, etc)
 308  *	@sk_protocol: which protocol this socket belongs in this network family
 
 309  *	@sk_peer_pid: &struct pid for this socket's peer
 310  *	@sk_peer_cred: %SO_PEERCRED setting
 311  *	@sk_rcvlowat: %SO_RCVLOWAT setting
 312  *	@sk_rcvtimeo: %SO_RCVTIMEO setting
 313  *	@sk_sndtimeo: %SO_SNDTIMEO setting
 314  *	@sk_txhash: computed flow hash for use on transmit
 
 315  *	@sk_filter: socket filtering instructions
 316  *	@sk_timer: sock cleanup timer
 317  *	@sk_stamp: time stamp of last packet received
 318  *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
 319  *	@sk_tsflags: SO_TIMESTAMPING flags
 
 
 
 320  *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
 321  *	              for timestamping
 322  *	@sk_tskey: counter to disambiguate concurrent tstamp requests
 323  *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
 324  *	@sk_socket: Identd and reporting IO signals
 325  *	@sk_user_data: RPC layer private data
 326  *	@sk_frag: cached page frag
 327  *	@sk_peek_off: current peek_offset value
 328  *	@sk_send_head: front of stuff to transmit
 329  *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
 330  *	@sk_tx_skb_cache: cache copy of recently accessed TX skb
 331  *	@sk_security: used by security modules
 332  *	@sk_mark: generic packet mark
 333  *	@sk_cgrp_data: cgroup data for this cgroup
 334  *	@sk_memcg: this socket's memory cgroup association
 335  *	@sk_write_pending: a write to stream socket waits to start
 336  *	@sk_state_change: callback to indicate change in the state of the sock
 337  *	@sk_data_ready: callback to indicate there is data to be processed
 338  *	@sk_write_space: callback to indicate there is bf sending space available
 339  *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
 340  *	@sk_backlog_rcv: callback to process the backlog
 341  *	@sk_validate_xmit_skb: ptr to an optional validate function
 342  *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
 343  *	@sk_reuseport_cb: reuseport group container
 344  *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
 345  *	@sk_rcu: used during RCU grace period
 346  *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
 347  *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
 348  *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
 349  *	@sk_txtime_unused: unused txtime flags
 
 
 350  */
 351struct sock {
 352	/*
 353	 * Now struct inet_timewait_sock also uses sock_common, so please just
 354	 * don't add nothing before this first member (__sk_common) --acme
 355	 */
 356	struct sock_common	__sk_common;
 357#define sk_node			__sk_common.skc_node
 358#define sk_nulls_node		__sk_common.skc_nulls_node
 359#define sk_refcnt		__sk_common.skc_refcnt
 360#define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
 361#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
 362#define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
 363#endif
 364
 365#define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
 366#define sk_dontcopy_end		__sk_common.skc_dontcopy_end
 367#define sk_hash			__sk_common.skc_hash
 368#define sk_portpair		__sk_common.skc_portpair
 369#define sk_num			__sk_common.skc_num
 370#define sk_dport		__sk_common.skc_dport
 371#define sk_addrpair		__sk_common.skc_addrpair
 372#define sk_daddr		__sk_common.skc_daddr
 373#define sk_rcv_saddr		__sk_common.skc_rcv_saddr
 374#define sk_family		__sk_common.skc_family
 375#define sk_state		__sk_common.skc_state
 376#define sk_reuse		__sk_common.skc_reuse
 377#define sk_reuseport		__sk_common.skc_reuseport
 378#define sk_ipv6only		__sk_common.skc_ipv6only
 379#define sk_net_refcnt		__sk_common.skc_net_refcnt
 380#define sk_bound_dev_if		__sk_common.skc_bound_dev_if
 381#define sk_bind_node		__sk_common.skc_bind_node
 382#define sk_prot			__sk_common.skc_prot
 383#define sk_net			__sk_common.skc_net
 384#define sk_v6_daddr		__sk_common.skc_v6_daddr
 385#define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
 386#define sk_cookie		__sk_common.skc_cookie
 387#define sk_incoming_cpu		__sk_common.skc_incoming_cpu
 388#define sk_flags		__sk_common.skc_flags
 389#define sk_rxhash		__sk_common.skc_rxhash
 390
 
 
 
 
 
 391	socket_lock_t		sk_lock;
 392	atomic_t		sk_drops;
 393	int			sk_rcvlowat;
 394	struct sk_buff_head	sk_error_queue;
 395	struct sk_buff		*sk_rx_skb_cache;
 396	struct sk_buff_head	sk_receive_queue;
 397	/*
 398	 * The backlog queue is special, it is always used with
 399	 * the per-socket spinlock held and requires low latency
 400	 * access. Therefore we special case it's implementation.
 401	 * Note : rmem_alloc is in this structure to fill a hole
 402	 * on 64bit arches, not because its logically part of
 403	 * backlog.
 404	 */
 405	struct {
 406		atomic_t	rmem_alloc;
 407		int		len;
 408		struct sk_buff	*head;
 409		struct sk_buff	*tail;
 410	} sk_backlog;
 
 411#define sk_rmem_alloc sk_backlog.rmem_alloc
 412
 413	int			sk_forward_alloc;
 
 414#ifdef CONFIG_NET_RX_BUSY_POLL
 415	unsigned int		sk_ll_usec;
 416	/* ===== mostly read cache line ===== */
 417	unsigned int		sk_napi_id;
 418#endif
 419	int			sk_rcvbuf;
 420
 421	struct sk_filter __rcu	*sk_filter;
 422	union {
 423		struct socket_wq __rcu	*sk_wq;
 424		/* private: */
 425		struct socket_wq	*sk_wq_raw;
 426		/* public: */
 427	};
 428#ifdef CONFIG_XFRM
 429	struct xfrm_policy __rcu *sk_policy[2];
 430#endif
 431	struct dst_entry	*sk_rx_dst;
 432	struct dst_entry __rcu	*sk_dst_cache;
 433	atomic_t		sk_omem_alloc;
 434	int			sk_sndbuf;
 435
 436	/* ===== cache line for TX ===== */
 437	int			sk_wmem_queued;
 438	refcount_t		sk_wmem_alloc;
 439	unsigned long		sk_tsq_flags;
 440	union {
 441		struct sk_buff	*sk_send_head;
 442		struct rb_root	tcp_rtx_queue;
 443	};
 444	struct sk_buff		*sk_tx_skb_cache;
 445	struct sk_buff_head	sk_write_queue;
 446	__s32			sk_peek_off;
 447	int			sk_write_pending;
 448	__u32			sk_dst_pending_confirm;
 449	u32			sk_pacing_status; /* see enum sk_pacing */
 450	long			sk_sndtimeo;
 451	struct timer_list	sk_timer;
 452	__u32			sk_priority;
 453	__u32			sk_mark;
 454	unsigned long		sk_pacing_rate; /* bytes per second */
 455	unsigned long		sk_max_pacing_rate;
 456	struct page_frag	sk_frag;
 457	netdev_features_t	sk_route_caps;
 458	netdev_features_t	sk_route_nocaps;
 459	netdev_features_t	sk_route_forced_caps;
 460	int			sk_gso_type;
 461	unsigned int		sk_gso_max_size;
 462	gfp_t			sk_allocation;
 463	__u32			sk_txhash;
 464
 465	/*
 466	 * Because of non atomicity rules, all
 467	 * changes are protected by socket lock.
 468	 */
 469	u8			sk_padding : 1,
 470				sk_kern_sock : 1,
 471				sk_no_check_tx : 1,
 472				sk_no_check_rx : 1,
 473				sk_userlocks : 4;
 474	u8			sk_pacing_shift;
 475	u16			sk_type;
 476	u16			sk_protocol;
 477	u16			sk_gso_max_segs;
 478	unsigned long	        sk_lingertime;
 479	struct proto		*sk_prot_creator;
 480	rwlock_t		sk_callback_lock;
 481	int			sk_err,
 482				sk_err_soft;
 483	u32			sk_ack_backlog;
 484	u32			sk_max_ack_backlog;
 485	kuid_t			sk_uid;
 
 486#ifdef CONFIG_NET_RX_BUSY_POLL
 487	u8			sk_prefer_busy_poll;
 488	u16			sk_busy_poll_budget;
 489#endif
 490	spinlock_t		sk_peer_lock;
 
 491	struct pid		*sk_peer_pid;
 492	const struct cred	*sk_peer_cred;
 493
 494	long			sk_rcvtimeo;
 495	ktime_t			sk_stamp;
 496#if BITS_PER_LONG==32
 497	seqlock_t		sk_stamp_seq;
 498#endif
 499	u16			sk_tsflags;
 500	int			sk_bind_phc;
 501	u8			sk_shutdown;
 502	u32			sk_tskey;
 503	atomic_t		sk_zckey;
 
 
 504
 505	u8			sk_clockid;
 506	u8			sk_txtime_deadline_mode : 1,
 507				sk_txtime_report_errors : 1,
 508				sk_txtime_unused : 6;
 
 509
 510	struct socket		*sk_socket;
 511	void			*sk_user_data;
 512#ifdef CONFIG_SECURITY
 513	void			*sk_security;
 514#endif
 515	struct sock_cgroup_data	sk_cgrp_data;
 516	struct mem_cgroup	*sk_memcg;
 517	void			(*sk_state_change)(struct sock *sk);
 518	void			(*sk_data_ready)(struct sock *sk);
 519	void			(*sk_write_space)(struct sock *sk);
 520	void			(*sk_error_report)(struct sock *sk);
 521	int			(*sk_backlog_rcv)(struct sock *sk,
 522						  struct sk_buff *skb);
 523#ifdef CONFIG_SOCK_VALIDATE_XMIT
 524	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
 525							struct net_device *dev,
 526							struct sk_buff *skb);
 527#endif
 528	void                    (*sk_destruct)(struct sock *sk);
 529	struct sock_reuseport __rcu	*sk_reuseport_cb;
 530#ifdef CONFIG_BPF_SYSCALL
 531	struct bpf_local_storage __rcu	*sk_bpf_storage;
 532#endif
 533	struct rcu_head		sk_rcu;
 
 
 534};
 535
 536enum sk_pacing {
 537	SK_PACING_NONE		= 0,
 538	SK_PACING_NEEDED	= 1,
 539	SK_PACING_FQ		= 2,
 540};
 541
 542/* Pointer stored in sk_user_data might not be suitable for copying
 543 * when cloning the socket. For instance, it can point to a reference
 544 * counted object. sk_user_data bottom bit is set if pointer must not
 545 * be copied.
 
 
 
 
 
 
 
 
 
 
 546 */
 547#define SK_USER_DATA_NOCOPY	1UL
 548#define SK_USER_DATA_BPF	2UL	/* Managed by BPF */
 549#define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF)
 
 
 550
 551/**
 552 * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
 553 * @sk: socket
 554 */
 555static inline bool sk_user_data_is_nocopy(const struct sock *sk)
 556{
 557	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
 558}
 559
 560#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
 561
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 562#define rcu_dereference_sk_user_data(sk)				\
 
 
 563({									\
 564	void *__tmp = rcu_dereference(__sk_user_data((sk)));		\
 565	(void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK);		\
 566})
 567#define rcu_assign_sk_user_data(sk, ptr)				\
 568({									\
 569	uintptr_t __tmp = (uintptr_t)(ptr);				\
 570	WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);			\
 571	rcu_assign_pointer(__sk_user_data((sk)), __tmp);		\
 572})
 573#define rcu_assign_sk_user_data_nocopy(sk, ptr)				\
 574({									\
 575	uintptr_t __tmp = (uintptr_t)(ptr);				\
 576	WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);			\
 577	rcu_assign_pointer(__sk_user_data((sk)),			\
 578			   __tmp | SK_USER_DATA_NOCOPY);		\
 579})
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 580
 581/*
 582 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
 583 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
 584 * on a socket means that the socket will reuse everybody else's port
 585 * without looking at the other's sk_reuse value.
 586 */
 587
 588#define SK_NO_REUSE	0
 589#define SK_CAN_REUSE	1
 590#define SK_FORCE_REUSE	2
 591
 592int sk_set_peek_off(struct sock *sk, int val);
 593
 594static inline int sk_peek_offset(struct sock *sk, int flags)
 595{
 596	if (unlikely(flags & MSG_PEEK)) {
 597		return READ_ONCE(sk->sk_peek_off);
 598	}
 599
 600	return 0;
 601}
 602
 603static inline void sk_peek_offset_bwd(struct sock *sk, int val)
 604{
 605	s32 off = READ_ONCE(sk->sk_peek_off);
 606
 607	if (unlikely(off >= 0)) {
 608		off = max_t(s32, off - val, 0);
 609		WRITE_ONCE(sk->sk_peek_off, off);
 610	}
 611}
 612
 613static inline void sk_peek_offset_fwd(struct sock *sk, int val)
 614{
 615	sk_peek_offset_bwd(sk, -val);
 616}
 617
 618/*
 619 * Hashed lists helper routines
 620 */
 621static inline struct sock *sk_entry(const struct hlist_node *node)
 622{
 623	return hlist_entry(node, struct sock, sk_node);
 624}
 625
 626static inline struct sock *__sk_head(const struct hlist_head *head)
 627{
 628	return hlist_entry(head->first, struct sock, sk_node);
 629}
 630
 631static inline struct sock *sk_head(const struct hlist_head *head)
 632{
 633	return hlist_empty(head) ? NULL : __sk_head(head);
 634}
 635
 636static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
 637{
 638	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
 639}
 640
 641static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
 642{
 643	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
 644}
 645
 646static inline struct sock *sk_next(const struct sock *sk)
 647{
 648	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
 649}
 650
 651static inline struct sock *sk_nulls_next(const struct sock *sk)
 652{
 653	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
 654		hlist_nulls_entry(sk->sk_nulls_node.next,
 655				  struct sock, sk_nulls_node) :
 656		NULL;
 657}
 658
 659static inline bool sk_unhashed(const struct sock *sk)
 660{
 661	return hlist_unhashed(&sk->sk_node);
 662}
 663
 664static inline bool sk_hashed(const struct sock *sk)
 665{
 666	return !sk_unhashed(sk);
 667}
 668
 669static inline void sk_node_init(struct hlist_node *node)
 670{
 671	node->pprev = NULL;
 672}
 673
 674static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
 675{
 676	node->pprev = NULL;
 677}
 678
 679static inline void __sk_del_node(struct sock *sk)
 680{
 681	__hlist_del(&sk->sk_node);
 682}
 683
 684/* NB: equivalent to hlist_del_init_rcu */
 685static inline bool __sk_del_node_init(struct sock *sk)
 686{
 687	if (sk_hashed(sk)) {
 688		__sk_del_node(sk);
 689		sk_node_init(&sk->sk_node);
 690		return true;
 691	}
 692	return false;
 693}
 694
 695/* Grab socket reference count. This operation is valid only
 696   when sk is ALREADY grabbed f.e. it is found in hash table
 697   or a list and the lookup is made under lock preventing hash table
 698   modifications.
 699 */
 700
 701static __always_inline void sock_hold(struct sock *sk)
 702{
 703	refcount_inc(&sk->sk_refcnt);
 704}
 705
 706/* Ungrab socket in the context, which assumes that socket refcnt
 707   cannot hit zero, f.e. it is true in context of any socketcall.
 708 */
 709static __always_inline void __sock_put(struct sock *sk)
 710{
 711	refcount_dec(&sk->sk_refcnt);
 712}
 713
 714static inline bool sk_del_node_init(struct sock *sk)
 715{
 716	bool rc = __sk_del_node_init(sk);
 717
 718	if (rc) {
 719		/* paranoid for a while -acme */
 720		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
 721		__sock_put(sk);
 722	}
 723	return rc;
 724}
 725#define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
 726
 727static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
 728{
 729	if (sk_hashed(sk)) {
 730		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
 731		return true;
 732	}
 733	return false;
 734}
 735
 736static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
 737{
 738	bool rc = __sk_nulls_del_node_init_rcu(sk);
 739
 740	if (rc) {
 741		/* paranoid for a while -acme */
 742		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
 743		__sock_put(sk);
 744	}
 745	return rc;
 746}
 747
 748static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
 749{
 750	hlist_add_head(&sk->sk_node, list);
 751}
 752
 753static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
 754{
 755	sock_hold(sk);
 756	__sk_add_node(sk, list);
 757}
 758
 759static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
 760{
 761	sock_hold(sk);
 762	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
 763	    sk->sk_family == AF_INET6)
 764		hlist_add_tail_rcu(&sk->sk_node, list);
 765	else
 766		hlist_add_head_rcu(&sk->sk_node, list);
 767}
 768
 769static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
 770{
 771	sock_hold(sk);
 772	hlist_add_tail_rcu(&sk->sk_node, list);
 773}
 774
 775static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 776{
 777	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
 778}
 779
 780static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
 781{
 782	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
 783}
 784
 785static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 786{
 787	sock_hold(sk);
 788	__sk_nulls_add_node_rcu(sk, list);
 789}
 790
 791static inline void __sk_del_bind_node(struct sock *sk)
 792{
 793	__hlist_del(&sk->sk_bind_node);
 794}
 795
 796static inline void sk_add_bind_node(struct sock *sk,
 797					struct hlist_head *list)
 798{
 799	hlist_add_head(&sk->sk_bind_node, list);
 800}
 801
 
 
 
 
 
 
 
 
 
 
 802#define sk_for_each(__sk, list) \
 803	hlist_for_each_entry(__sk, list, sk_node)
 804#define sk_for_each_rcu(__sk, list) \
 805	hlist_for_each_entry_rcu(__sk, list, sk_node)
 806#define sk_nulls_for_each(__sk, node, list) \
 807	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
 808#define sk_nulls_for_each_rcu(__sk, node, list) \
 809	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
 810#define sk_for_each_from(__sk) \
 811	hlist_for_each_entry_from(__sk, sk_node)
 812#define sk_nulls_for_each_from(__sk, node) \
 813	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
 814		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
 815#define sk_for_each_safe(__sk, tmp, list) \
 816	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
 817#define sk_for_each_bound(__sk, list) \
 818	hlist_for_each_entry(__sk, list, sk_bind_node)
 
 
 819
 820/**
 821 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
 822 * @tpos:	the type * to use as a loop cursor.
 823 * @pos:	the &struct hlist_node to use as a loop cursor.
 824 * @head:	the head for your list.
 825 * @offset:	offset of hlist_node within the struct.
 826 *
 827 */
 828#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
 829	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
 830	     pos != NULL &&						       \
 831		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
 832	     pos = rcu_dereference(hlist_next_rcu(pos)))
 833
 834static inline struct user_namespace *sk_user_ns(struct sock *sk)
 835{
 836	/* Careful only use this in a context where these parameters
 837	 * can not change and must all be valid, such as recvmsg from
 838	 * userspace.
 839	 */
 840	return sk->sk_socket->file->f_cred->user_ns;
 841}
 842
 843/* Sock flags */
 844enum sock_flags {
 845	SOCK_DEAD,
 846	SOCK_DONE,
 847	SOCK_URGINLINE,
 848	SOCK_KEEPOPEN,
 849	SOCK_LINGER,
 850	SOCK_DESTROY,
 851	SOCK_BROADCAST,
 852	SOCK_TIMESTAMP,
 853	SOCK_ZAPPED,
 854	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
 855	SOCK_DBG, /* %SO_DEBUG setting */
 856	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
 857	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
 858	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
 859	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
 860	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
 861	SOCK_FASYNC, /* fasync() active */
 862	SOCK_RXQ_OVFL,
 863	SOCK_ZEROCOPY, /* buffers from userspace */
 864	SOCK_WIFI_STATUS, /* push wifi status to userspace */
 865	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
 866		     * Will use last 4 bytes of packet sent from
 867		     * user-space instead.
 868		     */
 869	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
 870	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
 871	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
 872	SOCK_TXTIME,
 873	SOCK_XDP, /* XDP is attached */
 874	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
 
 875};
 876
 877#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
 878
 879static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
 880{
 881	nsk->sk_flags = osk->sk_flags;
 882}
 883
 884static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
 885{
 886	__set_bit(flag, &sk->sk_flags);
 887}
 888
 889static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
 890{
 891	__clear_bit(flag, &sk->sk_flags);
 892}
 893
 894static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
 895				     int valbool)
 896{
 897	if (valbool)
 898		sock_set_flag(sk, bit);
 899	else
 900		sock_reset_flag(sk, bit);
 901}
 902
 903static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
 904{
 905	return test_bit(flag, &sk->sk_flags);
 906}
 907
 908#ifdef CONFIG_NET
 909DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
 910static inline int sk_memalloc_socks(void)
 911{
 912	return static_branch_unlikely(&memalloc_socks_key);
 913}
 914
 915void __receive_sock(struct file *file);
 916#else
 917
 918static inline int sk_memalloc_socks(void)
 919{
 920	return 0;
 921}
 922
 923static inline void __receive_sock(struct file *file)
 924{ }
 925#endif
 926
 927static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
 928{
 929	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
 930}
 931
 932static inline void sk_acceptq_removed(struct sock *sk)
 933{
 934	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
 935}
 936
 937static inline void sk_acceptq_added(struct sock *sk)
 938{
 939	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
 940}
 941
 942/* Note: If you think the test should be:
 943 *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
 944 * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
 945 */
 946static inline bool sk_acceptq_is_full(const struct sock *sk)
 947{
 948	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
 949}
 950
 951/*
 952 * Compute minimal free write space needed to queue new packets.
 953 */
 954static inline int sk_stream_min_wspace(const struct sock *sk)
 955{
 956	return READ_ONCE(sk->sk_wmem_queued) >> 1;
 957}
 958
 959static inline int sk_stream_wspace(const struct sock *sk)
 960{
 961	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
 962}
 963
 964static inline void sk_wmem_queued_add(struct sock *sk, int val)
 965{
 966	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
 967}
 968
 969void sk_stream_write_space(struct sock *sk);
 970
 971/* OOB backlog add */
 972static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
 973{
 974	/* dont let skb dst not refcounted, we are going to leave rcu lock */
 975	skb_dst_force(skb);
 976
 977	if (!sk->sk_backlog.tail)
 978		WRITE_ONCE(sk->sk_backlog.head, skb);
 979	else
 980		sk->sk_backlog.tail->next = skb;
 981
 982	WRITE_ONCE(sk->sk_backlog.tail, skb);
 983	skb->next = NULL;
 984}
 985
 986/*
 987 * Take into account size of receive queue and backlog queue
 988 * Do not take into account this skb truesize,
 989 * to allow even a single big packet to come.
 990 */
 991static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
 992{
 993	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
 994
 995	return qsize > limit;
 996}
 997
 998/* The per-socket spinlock must be held here. */
 999static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1000					      unsigned int limit)
1001{
1002	if (sk_rcvqueues_full(sk, limit))
1003		return -ENOBUFS;
1004
1005	/*
1006	 * If the skb was allocated from pfmemalloc reserves, only
1007	 * allow SOCK_MEMALLOC sockets to use it as this socket is
1008	 * helping free memory
1009	 */
1010	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1011		return -ENOMEM;
1012
1013	__sk_add_backlog(sk, skb);
1014	sk->sk_backlog.len += skb->truesize;
1015	return 0;
1016}
1017
1018int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1019
 
 
 
1020static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1021{
1022	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1023		return __sk_backlog_rcv(sk, skb);
1024
1025	return sk->sk_backlog_rcv(sk, skb);
 
 
 
1026}
1027
1028static inline void sk_incoming_cpu_update(struct sock *sk)
1029{
1030	int cpu = raw_smp_processor_id();
1031
1032	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1033		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1034}
1035
1036static inline void sock_rps_record_flow_hash(__u32 hash)
1037{
1038#ifdef CONFIG_RPS
1039	struct rps_sock_flow_table *sock_flow_table;
1040
1041	rcu_read_lock();
1042	sock_flow_table = rcu_dereference(rps_sock_flow_table);
1043	rps_record_sock_flow(sock_flow_table, hash);
1044	rcu_read_unlock();
1045#endif
1046}
1047
1048static inline void sock_rps_record_flow(const struct sock *sk)
1049{
1050#ifdef CONFIG_RPS
1051	if (static_branch_unlikely(&rfs_needed)) {
1052		/* Reading sk->sk_rxhash might incur an expensive cache line
1053		 * miss.
1054		 *
1055		 * TCP_ESTABLISHED does cover almost all states where RFS
1056		 * might be useful, and is cheaper [1] than testing :
1057		 *	IPv4: inet_sk(sk)->inet_daddr
1058		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1059		 * OR	an additional socket flag
1060		 * [1] : sk_state and sk_prot are in the same cache line.
1061		 */
1062		if (sk->sk_state == TCP_ESTABLISHED)
1063			sock_rps_record_flow_hash(sk->sk_rxhash);
1064	}
1065#endif
1066}
1067
1068static inline void sock_rps_save_rxhash(struct sock *sk,
1069					const struct sk_buff *skb)
1070{
1071#ifdef CONFIG_RPS
1072	if (unlikely(sk->sk_rxhash != skb->hash))
1073		sk->sk_rxhash = skb->hash;
1074#endif
1075}
1076
1077static inline void sock_rps_reset_rxhash(struct sock *sk)
1078{
1079#ifdef CONFIG_RPS
1080	sk->sk_rxhash = 0;
1081#endif
1082}
1083
1084#define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1085	({	int __rc;						\
1086		release_sock(__sk);					\
1087		__rc = __condition;					\
1088		if (!__rc) {						\
1089			*(__timeo) = wait_woken(__wait,			\
1090						TASK_INTERRUPTIBLE,	\
1091						*(__timeo));		\
1092		}							\
1093		sched_annotate_sleep();					\
1094		lock_sock(__sk);					\
1095		__rc = __condition;					\
1096		__rc;							\
1097	})
1098
1099int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1100int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1101void sk_stream_wait_close(struct sock *sk, long timeo_p);
1102int sk_stream_error(struct sock *sk, int flags, int err);
1103void sk_stream_kill_queues(struct sock *sk);
1104void sk_set_memalloc(struct sock *sk);
1105void sk_clear_memalloc(struct sock *sk);
1106
1107void __sk_flush_backlog(struct sock *sk);
1108
1109static inline bool sk_flush_backlog(struct sock *sk)
1110{
1111	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1112		__sk_flush_backlog(sk);
1113		return true;
1114	}
1115	return false;
1116}
1117
1118int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1119
1120struct request_sock_ops;
1121struct timewait_sock_ops;
1122struct inet_hashinfo;
1123struct raw_hashinfo;
1124struct smc_hashinfo;
1125struct module;
1126struct sk_psock;
1127
1128/*
1129 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1130 * un-modified. Special care is taken when initializing object to zero.
1131 */
1132static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1133{
1134	if (offsetof(struct sock, sk_node.next) != 0)
1135		memset(sk, 0, offsetof(struct sock, sk_node.next));
1136	memset(&sk->sk_node.pprev, 0,
1137	       size - offsetof(struct sock, sk_node.pprev));
1138}
1139
1140/* Networking protocol blocks we attach to sockets.
1141 * socket layer -> transport layer interface
1142 */
1143struct proto {
1144	void			(*close)(struct sock *sk,
1145					long timeout);
1146	int			(*pre_connect)(struct sock *sk,
1147					struct sockaddr *uaddr,
1148					int addr_len);
1149	int			(*connect)(struct sock *sk,
1150					struct sockaddr *uaddr,
1151					int addr_len);
1152	int			(*disconnect)(struct sock *sk, int flags);
1153
1154	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
1155					  bool kern);
1156
1157	int			(*ioctl)(struct sock *sk, int cmd,
1158					 unsigned long arg);
1159	int			(*init)(struct sock *sk);
1160	void			(*destroy)(struct sock *sk);
1161	void			(*shutdown)(struct sock *sk, int how);
1162	int			(*setsockopt)(struct sock *sk, int level,
1163					int optname, sockptr_t optval,
1164					unsigned int optlen);
1165	int			(*getsockopt)(struct sock *sk, int level,
1166					int optname, char __user *optval,
1167					int __user *option);
1168	void			(*keepalive)(struct sock *sk, int valbool);
1169#ifdef CONFIG_COMPAT
1170	int			(*compat_ioctl)(struct sock *sk,
1171					unsigned int cmd, unsigned long arg);
1172#endif
1173	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1174					   size_t len);
1175	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1176					   size_t len, int noblock, int flags,
1177					   int *addr_len);
1178	int			(*sendpage)(struct sock *sk, struct page *page,
1179					int offset, size_t size, int flags);
1180	int			(*bind)(struct sock *sk,
1181					struct sockaddr *addr, int addr_len);
1182	int			(*bind_add)(struct sock *sk,
1183					struct sockaddr *addr, int addr_len);
1184
1185	int			(*backlog_rcv) (struct sock *sk,
1186						struct sk_buff *skb);
1187	bool			(*bpf_bypass_getsockopt)(int level,
1188							 int optname);
1189
1190	void		(*release_cb)(struct sock *sk);
1191
1192	/* Keeping track of sk's, looking them up, and port selection methods. */
1193	int			(*hash)(struct sock *sk);
1194	void			(*unhash)(struct sock *sk);
1195	void			(*rehash)(struct sock *sk);
1196	int			(*get_port)(struct sock *sk, unsigned short snum);
 
1197#ifdef CONFIG_BPF_SYSCALL
1198	int			(*psock_update_sk_prot)(struct sock *sk,
1199							struct sk_psock *psock,
1200							bool restore);
1201#endif
1202
1203	/* Keeping track of sockets in use */
1204#ifdef CONFIG_PROC_FS
1205	unsigned int		inuse_idx;
1206#endif
1207
 
 
 
 
1208	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1209	bool			(*stream_memory_read)(const struct sock *sk);
1210	/* Memory pressure */
1211	void			(*enter_memory_pressure)(struct sock *sk);
1212	void			(*leave_memory_pressure)(struct sock *sk);
1213	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
 
1214	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
 
1215	/*
1216	 * Pressure flag: try to collapse.
1217	 * Technical note: it is used by multiple contexts non atomically.
1218	 * All the __sk_mem_schedule() is of this nature: accounting
1219	 * is strict, actions are advisory and have some latency.
1220	 */
1221	unsigned long		*memory_pressure;
1222	long			*sysctl_mem;
1223
1224	int			*sysctl_wmem;
1225	int			*sysctl_rmem;
1226	u32			sysctl_wmem_offset;
1227	u32			sysctl_rmem_offset;
1228
1229	int			max_header;
1230	bool			no_autobind;
1231
1232	struct kmem_cache	*slab;
1233	unsigned int		obj_size;
1234	slab_flags_t		slab_flags;
1235	unsigned int		useroffset;	/* Usercopy region offset */
1236	unsigned int		usersize;	/* Usercopy region size */
1237
1238	struct percpu_counter	*orphan_count;
1239
1240	struct request_sock_ops	*rsk_prot;
1241	struct timewait_sock_ops *twsk_prot;
1242
1243	union {
1244		struct inet_hashinfo	*hashinfo;
1245		struct udp_table	*udp_table;
1246		struct raw_hashinfo	*raw_hash;
1247		struct smc_hashinfo	*smc_hash;
1248	} h;
1249
1250	struct module		*owner;
1251
1252	char			name[32];
1253
1254	struct list_head	node;
1255#ifdef SOCK_REFCNT_DEBUG
1256	atomic_t		socks;
1257#endif
1258	int			(*diag_destroy)(struct sock *sk, int err);
1259} __randomize_layout;
1260
1261int proto_register(struct proto *prot, int alloc_slab);
1262void proto_unregister(struct proto *prot);
1263int sock_load_diag_module(int family, int protocol);
1264
1265#ifdef SOCK_REFCNT_DEBUG
1266static inline void sk_refcnt_debug_inc(struct sock *sk)
1267{
1268	atomic_inc(&sk->sk_prot->socks);
1269}
1270
1271static inline void sk_refcnt_debug_dec(struct sock *sk)
1272{
1273	atomic_dec(&sk->sk_prot->socks);
1274	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1275	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1276}
1277
1278static inline void sk_refcnt_debug_release(const struct sock *sk)
1279{
1280	if (refcount_read(&sk->sk_refcnt) != 1)
1281		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1282		       sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1283}
1284#else /* SOCK_REFCNT_DEBUG */
1285#define sk_refcnt_debug_inc(sk) do { } while (0)
1286#define sk_refcnt_debug_dec(sk) do { } while (0)
1287#define sk_refcnt_debug_release(sk) do { } while (0)
1288#endif /* SOCK_REFCNT_DEBUG */
1289
1290INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1291
 
 
 
 
 
 
 
 
 
1292static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1293{
1294	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1295		return false;
1296
1297#ifdef CONFIG_INET
1298	return sk->sk_prot->stream_memory_free ?
1299		INDIRECT_CALL_1(sk->sk_prot->stream_memory_free,
1300			        tcp_stream_memory_free,
1301				sk, wake) : true;
1302#else
1303	return sk->sk_prot->stream_memory_free ?
1304		sk->sk_prot->stream_memory_free(sk, wake) : true;
1305#endif
1306}
1307
1308static inline bool sk_stream_memory_free(const struct sock *sk)
1309{
1310	return __sk_stream_memory_free(sk, 0);
1311}
1312
1313static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1314{
1315	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1316	       __sk_stream_memory_free(sk, wake);
1317}
1318
1319static inline bool sk_stream_is_writeable(const struct sock *sk)
1320{
1321	return __sk_stream_is_writeable(sk, 0);
1322}
1323
1324static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1325					    struct cgroup *ancestor)
1326{
1327#ifdef CONFIG_SOCK_CGROUP_DATA
1328	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1329				    ancestor);
1330#else
1331	return -ENOTSUPP;
1332#endif
1333}
1334
1335static inline bool sk_has_memory_pressure(const struct sock *sk)
1336{
1337	return sk->sk_prot->memory_pressure != NULL;
1338}
1339
1340static inline bool sk_under_memory_pressure(const struct sock *sk)
1341{
1342	if (!sk->sk_prot->memory_pressure)
1343		return false;
1344
1345	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1346	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
1347		return true;
1348
1349	return !!*sk->sk_prot->memory_pressure;
1350}
1351
1352static inline long
1353sk_memory_allocated(const struct sock *sk)
1354{
1355	return atomic_long_read(sk->sk_prot->memory_allocated);
1356}
1357
1358static inline long
 
 
 
 
 
 
 
 
 
1359sk_memory_allocated_add(struct sock *sk, int amt)
1360{
1361	return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
 
 
 
 
 
 
 
 
1362}
1363
1364static inline void
1365sk_memory_allocated_sub(struct sock *sk, int amt)
1366{
1367	atomic_long_sub(amt, sk->sk_prot->memory_allocated);
 
 
 
 
 
 
 
 
1368}
1369
1370#define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1371
1372static inline void sk_sockets_allocated_dec(struct sock *sk)
1373{
1374	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1375				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1376}
1377
1378static inline void sk_sockets_allocated_inc(struct sock *sk)
1379{
1380	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1381				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1382}
1383
1384static inline u64
1385sk_sockets_allocated_read_positive(struct sock *sk)
1386{
1387	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1388}
1389
1390static inline int
1391proto_sockets_allocated_sum_positive(struct proto *prot)
1392{
1393	return percpu_counter_sum_positive(prot->sockets_allocated);
1394}
1395
1396static inline long
1397proto_memory_allocated(struct proto *prot)
1398{
1399	return atomic_long_read(prot->memory_allocated);
1400}
1401
1402static inline bool
1403proto_memory_pressure(struct proto *prot)
1404{
1405	if (!prot->memory_pressure)
1406		return false;
1407	return !!*prot->memory_pressure;
1408}
1409
1410
1411#ifdef CONFIG_PROC_FS
1412/* Called with local bh disabled */
1413void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1414int sock_prot_inuse_get(struct net *net, struct proto *proto);
1415int sock_inuse_get(struct net *net);
1416#else
1417static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1418		int inc)
 
 
 
 
1419{
1420}
1421#endif
1422
1423
1424/* With per-bucket locks this operation is not-atomic, so that
1425 * this version is not worse.
1426 */
1427static inline int __sk_prot_rehash(struct sock *sk)
1428{
1429	sk->sk_prot->unhash(sk);
1430	return sk->sk_prot->hash(sk);
1431}
1432
1433/* About 10 seconds */
1434#define SOCK_DESTROY_TIME (10*HZ)
1435
1436/* Sockets 0-1023 can't be bound to unless you are superuser */
1437#define PROT_SOCK	1024
1438
1439#define SHUTDOWN_MASK	3
1440#define RCV_SHUTDOWN	1
1441#define SEND_SHUTDOWN	2
1442
1443#define SOCK_SNDBUF_LOCK	1
1444#define SOCK_RCVBUF_LOCK	2
1445#define SOCK_BINDADDR_LOCK	4
1446#define SOCK_BINDPORT_LOCK	8
1447
1448struct socket_alloc {
1449	struct socket socket;
1450	struct inode vfs_inode;
1451};
1452
1453static inline struct socket *SOCKET_I(struct inode *inode)
1454{
1455	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1456}
1457
1458static inline struct inode *SOCK_INODE(struct socket *socket)
1459{
1460	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1461}
1462
1463/*
1464 * Functions for memory accounting
1465 */
1466int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1467int __sk_mem_schedule(struct sock *sk, int size, int kind);
1468void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1469void __sk_mem_reclaim(struct sock *sk, int amount);
1470
1471/* We used to have PAGE_SIZE here, but systems with 64KB pages
1472 * do not necessarily have 16x time more memory than 4KB ones.
1473 */
1474#define SK_MEM_QUANTUM 4096
1475#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1476#define SK_MEM_SEND	0
1477#define SK_MEM_RECV	1
1478
1479/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1480static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1481{
1482	long val = sk->sk_prot->sysctl_mem[index];
1483
1484#if PAGE_SIZE > SK_MEM_QUANTUM
1485	val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1486#elif PAGE_SIZE < SK_MEM_QUANTUM
1487	val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1488#endif
1489	return val;
1490}
1491
1492static inline int sk_mem_pages(int amt)
1493{
1494	return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1495}
1496
1497static inline bool sk_has_account(struct sock *sk)
1498{
1499	/* return true if protocol supports memory accounting */
1500	return !!sk->sk_prot->memory_allocated;
1501}
1502
1503static inline bool sk_wmem_schedule(struct sock *sk, int size)
1504{
 
 
1505	if (!sk_has_account(sk))
1506		return true;
1507	return size <= sk->sk_forward_alloc ||
1508		__sk_mem_schedule(sk, size, SK_MEM_SEND);
1509}
1510
1511static inline bool
1512sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1513{
 
 
1514	if (!sk_has_account(sk))
1515		return true;
1516	return size <= sk->sk_forward_alloc ||
1517		__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1518		skb_pfmemalloc(skb);
1519}
1520
 
 
 
 
 
 
 
 
 
 
 
 
 
1521static inline void sk_mem_reclaim(struct sock *sk)
1522{
 
 
1523	if (!sk_has_account(sk))
1524		return;
1525	if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1526		__sk_mem_reclaim(sk, sk->sk_forward_alloc);
 
 
 
1527}
1528
1529static inline void sk_mem_reclaim_partial(struct sock *sk)
1530{
1531	if (!sk_has_account(sk))
1532		return;
1533	if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1534		__sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1535}
1536
1537static inline void sk_mem_charge(struct sock *sk, int size)
1538{
1539	if (!sk_has_account(sk))
1540		return;
1541	sk->sk_forward_alloc -= size;
1542}
1543
1544static inline void sk_mem_uncharge(struct sock *sk, int size)
1545{
1546	if (!sk_has_account(sk))
1547		return;
1548	sk->sk_forward_alloc += size;
1549
1550	/* Avoid a possible overflow.
1551	 * TCP send queues can make this happen, if sk_mem_reclaim()
1552	 * is not called and more than 2 GBytes are released at once.
1553	 *
1554	 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1555	 * no need to hold that much forward allocation anyway.
1556	 */
1557	if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1558		__sk_mem_reclaim(sk, 1 << 20);
1559}
1560
1561DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
1562static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1563{
1564	sk_wmem_queued_add(sk, -skb->truesize);
1565	sk_mem_uncharge(sk, skb->truesize);
1566	if (static_branch_unlikely(&tcp_tx_skb_cache_key) &&
1567	    !sk->sk_tx_skb_cache && !skb_cloned(skb)) {
1568		skb_ext_reset(skb);
1569		skb_zcopy_clear(skb, true);
1570		sk->sk_tx_skb_cache = skb;
1571		return;
1572	}
1573	__kfree_skb(skb);
1574}
1575
1576static inline void sock_release_ownership(struct sock *sk)
1577{
1578	if (sk->sk_lock.owned) {
1579		sk->sk_lock.owned = 0;
1580
1581		/* The sk_lock has mutex_unlock() semantics: */
1582		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1583	}
1584}
1585
1586/*
1587 * Macro so as to not evaluate some arguments when
1588 * lockdep is not enabled.
1589 *
1590 * Mark both the sk_lock and the sk_lock.slock as a
1591 * per-address-family lock class.
1592 */
1593#define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1594do {									\
1595	sk->sk_lock.owned = 0;						\
1596	init_waitqueue_head(&sk->sk_lock.wq);				\
1597	spin_lock_init(&(sk)->sk_lock.slock);				\
1598	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1599			sizeof((sk)->sk_lock));				\
1600	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1601				(skey), (sname));				\
1602	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1603} while (0)
1604
1605static inline bool lockdep_sock_is_held(const struct sock *sk)
1606{
1607	return lockdep_is_held(&sk->sk_lock) ||
1608	       lockdep_is_held(&sk->sk_lock.slock);
1609}
1610
1611void lock_sock_nested(struct sock *sk, int subclass);
1612
1613static inline void lock_sock(struct sock *sk)
1614{
1615	lock_sock_nested(sk, 0);
1616}
1617
1618void __lock_sock(struct sock *sk);
1619void __release_sock(struct sock *sk);
1620void release_sock(struct sock *sk);
1621
1622/* BH context may only use the following locking interface. */
1623#define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1624#define bh_lock_sock_nested(__sk) \
1625				spin_lock_nested(&((__sk)->sk_lock.slock), \
1626				SINGLE_DEPTH_NESTING)
1627#define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1628
1629bool lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1630
1631/**
1632 * unlock_sock_fast - complement of lock_sock_fast
1633 * @sk: socket
1634 * @slow: slow mode
1635 *
1636 * fast unlock socket for user context.
1637 * If slow mode is on, we call regular release_sock()
1638 */
1639static inline void unlock_sock_fast(struct sock *sk, bool slow)
1640	__releases(&sk->sk_lock.slock)
1641{
1642	if (slow) {
1643		release_sock(sk);
1644		__release(&sk->sk_lock.slock);
1645	} else {
 
1646		spin_unlock_bh(&sk->sk_lock.slock);
1647	}
1648}
1649
 
 
 
 
 
1650/* Used by processes to "lock" a socket state, so that
1651 * interrupts and bottom half handlers won't change it
1652 * from under us. It essentially blocks any incoming
1653 * packets, so that we won't get any new data or any
1654 * packets that change the state of the socket.
1655 *
1656 * While locked, BH processing will add new packets to
1657 * the backlog queue.  This queue is processed by the
1658 * owner of the socket lock right before it is released.
1659 *
1660 * Since ~2.3.5 it is also exclusive sleep lock serializing
1661 * accesses from user process context.
1662 */
1663
1664static inline void sock_owned_by_me(const struct sock *sk)
1665{
1666#ifdef CONFIG_LOCKDEP
1667	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1668#endif
1669}
1670
1671static inline bool sock_owned_by_user(const struct sock *sk)
1672{
1673	sock_owned_by_me(sk);
1674	return sk->sk_lock.owned;
1675}
1676
1677static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1678{
1679	return sk->sk_lock.owned;
1680}
1681
 
 
 
 
 
 
 
 
 
 
1682/* no reclassification while locks are held */
1683static inline bool sock_allow_reclassification(const struct sock *csk)
1684{
1685	struct sock *sk = (struct sock *)csk;
1686
1687	return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
 
1688}
1689
1690struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1691		      struct proto *prot, int kern);
1692void sk_free(struct sock *sk);
1693void sk_destruct(struct sock *sk);
1694struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1695void sk_free_unlock_clone(struct sock *sk);
1696
1697struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1698			     gfp_t priority);
1699void __sock_wfree(struct sk_buff *skb);
1700void sock_wfree(struct sk_buff *skb);
1701struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1702			     gfp_t priority);
1703void skb_orphan_partial(struct sk_buff *skb);
1704void sock_rfree(struct sk_buff *skb);
1705void sock_efree(struct sk_buff *skb);
1706#ifdef CONFIG_INET
1707void sock_edemux(struct sk_buff *skb);
1708void sock_pfree(struct sk_buff *skb);
1709#else
1710#define sock_edemux sock_efree
1711#endif
1712
 
 
1713int sock_setsockopt(struct socket *sock, int level, int op,
1714		    sockptr_t optval, unsigned int optlen);
1715
 
 
1716int sock_getsockopt(struct socket *sock, int level, int op,
1717		    char __user *optval, int __user *optlen);
1718int sock_gettstamp(struct socket *sock, void __user *userstamp,
1719		   bool timeval, bool time32);
1720struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1721				    int noblock, int *errcode);
1722struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1723				     unsigned long data_len, int noblock,
1724				     int *errcode, int max_page_order);
 
 
 
 
 
 
 
 
1725void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1726void sock_kfree_s(struct sock *sk, void *mem, int size);
1727void sock_kzfree_s(struct sock *sk, void *mem, int size);
1728void sk_send_sigurg(struct sock *sk);
1729
 
 
 
 
 
 
 
1730struct sockcm_cookie {
1731	u64 transmit_time;
1732	u32 mark;
1733	u16 tsflags;
1734};
1735
1736static inline void sockcm_init(struct sockcm_cookie *sockc,
1737			       const struct sock *sk)
1738{
1739	*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1740}
1741
1742int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1743		     struct sockcm_cookie *sockc);
1744int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1745		   struct sockcm_cookie *sockc);
1746
1747/*
1748 * Functions to fill in entries in struct proto_ops when a protocol
1749 * does not implement a particular function.
1750 */
1751int sock_no_bind(struct socket *, struct sockaddr *, int);
1752int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1753int sock_no_socketpair(struct socket *, struct socket *);
1754int sock_no_accept(struct socket *, struct socket *, int, bool);
1755int sock_no_getname(struct socket *, struct sockaddr *, int);
1756int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1757int sock_no_listen(struct socket *, int);
1758int sock_no_shutdown(struct socket *, int);
1759int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1760int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1761int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1762int sock_no_mmap(struct file *file, struct socket *sock,
1763		 struct vm_area_struct *vma);
1764ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1765			 size_t size, int flags);
1766ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1767				int offset, size_t size, int flags);
1768
1769/*
1770 * Functions to fill in entries in struct proto_ops when a protocol
1771 * uses the inet style.
1772 */
1773int sock_common_getsockopt(struct socket *sock, int level, int optname,
1774				  char __user *optval, int __user *optlen);
1775int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1776			int flags);
1777int sock_common_setsockopt(struct socket *sock, int level, int optname,
1778			   sockptr_t optval, unsigned int optlen);
1779
1780void sk_common_release(struct sock *sk);
1781
1782/*
1783 *	Default socket callbacks and setup code
1784 */
1785
1786/* Initialise core socket variables */
1787void sock_init_data(struct socket *sock, struct sock *sk);
1788
1789/*
1790 * Socket reference counting postulates.
1791 *
1792 * * Each user of socket SHOULD hold a reference count.
1793 * * Each access point to socket (an hash table bucket, reference from a list,
1794 *   running timer, skb in flight MUST hold a reference count.
1795 * * When reference count hits 0, it means it will never increase back.
1796 * * When reference count hits 0, it means that no references from
1797 *   outside exist to this socket and current process on current CPU
1798 *   is last user and may/should destroy this socket.
1799 * * sk_free is called from any context: process, BH, IRQ. When
1800 *   it is called, socket has no references from outside -> sk_free
1801 *   may release descendant resources allocated by the socket, but
1802 *   to the time when it is called, socket is NOT referenced by any
1803 *   hash tables, lists etc.
1804 * * Packets, delivered from outside (from network or from another process)
1805 *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1806 *   when they sit in queue. Otherwise, packets will leak to hole, when
1807 *   socket is looked up by one cpu and unhasing is made by another CPU.
1808 *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1809 *   (leak to backlog). Packet socket does all the processing inside
1810 *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1811 *   use separate SMP lock, so that they are prone too.
1812 */
1813
1814/* Ungrab socket and destroy it, if it was the last reference. */
1815static inline void sock_put(struct sock *sk)
1816{
1817	if (refcount_dec_and_test(&sk->sk_refcnt))
1818		sk_free(sk);
1819}
1820/* Generic version of sock_put(), dealing with all sockets
1821 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1822 */
1823void sock_gen_put(struct sock *sk);
1824
1825int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1826		     unsigned int trim_cap, bool refcounted);
1827static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1828				 const int nested)
1829{
1830	return __sk_receive_skb(sk, skb, nested, 1, true);
1831}
1832
1833static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1834{
1835	/* sk_tx_queue_mapping accept only upto a 16-bit value */
1836	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1837		return;
1838	sk->sk_tx_queue_mapping = tx_queue;
1839}
1840
1841#define NO_QUEUE_MAPPING	USHRT_MAX
1842
1843static inline void sk_tx_queue_clear(struct sock *sk)
1844{
1845	sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1846}
1847
1848static inline int sk_tx_queue_get(const struct sock *sk)
1849{
1850	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1851		return sk->sk_tx_queue_mapping;
1852
1853	return -1;
1854}
1855
1856static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
 
 
1857{
1858#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
1859	if (skb_rx_queue_recorded(skb)) {
1860		u16 rx_queue = skb_get_rx_queue(skb);
1861
1862		if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1863			return;
1864
1865		sk->sk_rx_queue_mapping = rx_queue;
1866	}
1867#endif
1868}
1869
 
 
 
 
 
 
 
 
 
 
1870static inline void sk_rx_queue_clear(struct sock *sk)
1871{
1872#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
1873	sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1874#endif
1875}
1876
1877static inline int sk_rx_queue_get(const struct sock *sk)
1878{
1879#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
1880	if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1881		return sk->sk_rx_queue_mapping;
 
 
 
 
1882#endif
1883
1884	return -1;
1885}
1886
1887static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1888{
1889	sk->sk_socket = sock;
1890}
1891
1892static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1893{
1894	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1895	return &rcu_dereference_raw(sk->sk_wq)->wait;
1896}
1897/* Detach socket from process context.
1898 * Announce socket dead, detach it from wait queue and inode.
1899 * Note that parent inode held reference count on this struct sock,
1900 * we do not release it in this function, because protocol
1901 * probably wants some additional cleanups or even continuing
1902 * to work with this socket (TCP).
1903 */
1904static inline void sock_orphan(struct sock *sk)
1905{
1906	write_lock_bh(&sk->sk_callback_lock);
1907	sock_set_flag(sk, SOCK_DEAD);
1908	sk_set_socket(sk, NULL);
1909	sk->sk_wq  = NULL;
1910	write_unlock_bh(&sk->sk_callback_lock);
1911}
1912
1913static inline void sock_graft(struct sock *sk, struct socket *parent)
1914{
1915	WARN_ON(parent->sk);
1916	write_lock_bh(&sk->sk_callback_lock);
1917	rcu_assign_pointer(sk->sk_wq, &parent->wq);
1918	parent->sk = sk;
1919	sk_set_socket(sk, parent);
1920	sk->sk_uid = SOCK_INODE(parent)->i_uid;
1921	security_sock_graft(sk, parent);
1922	write_unlock_bh(&sk->sk_callback_lock);
1923}
1924
1925kuid_t sock_i_uid(struct sock *sk);
1926unsigned long sock_i_ino(struct sock *sk);
1927
1928static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1929{
1930	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1931}
1932
1933static inline u32 net_tx_rndhash(void)
1934{
1935	u32 v = prandom_u32();
1936
1937	return v ?: 1;
1938}
1939
1940static inline void sk_set_txhash(struct sock *sk)
1941{
1942	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
1943	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
1944}
1945
1946static inline bool sk_rethink_txhash(struct sock *sk)
1947{
1948	if (sk->sk_txhash) {
1949		sk_set_txhash(sk);
1950		return true;
1951	}
1952	return false;
1953}
1954
1955static inline struct dst_entry *
1956__sk_dst_get(struct sock *sk)
1957{
1958	return rcu_dereference_check(sk->sk_dst_cache,
1959				     lockdep_sock_is_held(sk));
1960}
1961
1962static inline struct dst_entry *
1963sk_dst_get(struct sock *sk)
1964{
1965	struct dst_entry *dst;
1966
1967	rcu_read_lock();
1968	dst = rcu_dereference(sk->sk_dst_cache);
1969	if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1970		dst = NULL;
1971	rcu_read_unlock();
1972	return dst;
1973}
1974
1975static inline void __dst_negative_advice(struct sock *sk)
1976{
1977	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1978
1979	if (dst && dst->ops->negative_advice) {
1980		ndst = dst->ops->negative_advice(dst);
1981
1982		if (ndst != dst) {
1983			rcu_assign_pointer(sk->sk_dst_cache, ndst);
1984			sk_tx_queue_clear(sk);
1985			sk->sk_dst_pending_confirm = 0;
1986		}
1987	}
1988}
1989
1990static inline void dst_negative_advice(struct sock *sk)
1991{
1992	sk_rethink_txhash(sk);
1993	__dst_negative_advice(sk);
1994}
1995
1996static inline void
1997__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1998{
1999	struct dst_entry *old_dst;
2000
2001	sk_tx_queue_clear(sk);
2002	sk->sk_dst_pending_confirm = 0;
2003	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2004					    lockdep_sock_is_held(sk));
2005	rcu_assign_pointer(sk->sk_dst_cache, dst);
2006	dst_release(old_dst);
2007}
2008
2009static inline void
2010sk_dst_set(struct sock *sk, struct dst_entry *dst)
2011{
2012	struct dst_entry *old_dst;
2013
2014	sk_tx_queue_clear(sk);
2015	sk->sk_dst_pending_confirm = 0;
2016	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
2017	dst_release(old_dst);
2018}
2019
2020static inline void
2021__sk_dst_reset(struct sock *sk)
2022{
2023	__sk_dst_set(sk, NULL);
2024}
2025
2026static inline void
2027sk_dst_reset(struct sock *sk)
2028{
2029	sk_dst_set(sk, NULL);
2030}
2031
2032struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2033
2034struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2035
2036static inline void sk_dst_confirm(struct sock *sk)
2037{
2038	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2039		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2040}
2041
2042static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2043{
2044	if (skb_get_dst_pending_confirm(skb)) {
2045		struct sock *sk = skb->sk;
2046		unsigned long now = jiffies;
2047
2048		/* avoid dirtying neighbour */
2049		if (READ_ONCE(n->confirmed) != now)
2050			WRITE_ONCE(n->confirmed, now);
2051		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2052			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
 
2053	}
2054}
2055
2056bool sk_mc_loop(struct sock *sk);
2057
2058static inline bool sk_can_gso(const struct sock *sk)
2059{
2060	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2061}
2062
2063void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2064
2065static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
2066{
2067	sk->sk_route_nocaps |= flags;
2068	sk->sk_route_caps &= ~flags;
2069}
2070
2071static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2072					   struct iov_iter *from, char *to,
2073					   int copy, int offset)
2074{
2075	if (skb->ip_summed == CHECKSUM_NONE) {
2076		__wsum csum = 0;
2077		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2078			return -EFAULT;
2079		skb->csum = csum_block_add(skb->csum, csum, offset);
2080	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2081		if (!copy_from_iter_full_nocache(to, copy, from))
2082			return -EFAULT;
2083	} else if (!copy_from_iter_full(to, copy, from))
2084		return -EFAULT;
2085
2086	return 0;
2087}
2088
2089static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2090				       struct iov_iter *from, int copy)
2091{
2092	int err, offset = skb->len;
2093
2094	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2095				       copy, offset);
2096	if (err)
2097		__skb_trim(skb, offset);
2098
2099	return err;
2100}
2101
2102static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2103					   struct sk_buff *skb,
2104					   struct page *page,
2105					   int off, int copy)
2106{
2107	int err;
2108
2109	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2110				       copy, skb->len);
2111	if (err)
2112		return err;
2113
2114	skb->len	     += copy;
2115	skb->data_len	     += copy;
2116	skb->truesize	     += copy;
2117	sk_wmem_queued_add(sk, copy);
2118	sk_mem_charge(sk, copy);
2119	return 0;
2120}
2121
2122/**
2123 * sk_wmem_alloc_get - returns write allocations
2124 * @sk: socket
2125 *
2126 * Return: sk_wmem_alloc minus initial offset of one
2127 */
2128static inline int sk_wmem_alloc_get(const struct sock *sk)
2129{
2130	return refcount_read(&sk->sk_wmem_alloc) - 1;
2131}
2132
2133/**
2134 * sk_rmem_alloc_get - returns read allocations
2135 * @sk: socket
2136 *
2137 * Return: sk_rmem_alloc
2138 */
2139static inline int sk_rmem_alloc_get(const struct sock *sk)
2140{
2141	return atomic_read(&sk->sk_rmem_alloc);
2142}
2143
2144/**
2145 * sk_has_allocations - check if allocations are outstanding
2146 * @sk: socket
2147 *
2148 * Return: true if socket has write or read allocations
2149 */
2150static inline bool sk_has_allocations(const struct sock *sk)
2151{
2152	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2153}
2154
2155/**
2156 * skwq_has_sleeper - check if there are any waiting processes
2157 * @wq: struct socket_wq
2158 *
2159 * Return: true if socket_wq has waiting processes
2160 *
2161 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2162 * barrier call. They were added due to the race found within the tcp code.
2163 *
2164 * Consider following tcp code paths::
2165 *
2166 *   CPU1                CPU2
2167 *   sys_select          receive packet
2168 *   ...                 ...
2169 *   __add_wait_queue    update tp->rcv_nxt
2170 *   ...                 ...
2171 *   tp->rcv_nxt check   sock_def_readable
2172 *   ...                 {
2173 *   schedule               rcu_read_lock();
2174 *                          wq = rcu_dereference(sk->sk_wq);
2175 *                          if (wq && waitqueue_active(&wq->wait))
2176 *                              wake_up_interruptible(&wq->wait)
2177 *                          ...
2178 *                       }
2179 *
2180 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2181 * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2182 * could then endup calling schedule and sleep forever if there are no more
2183 * data on the socket.
2184 *
2185 */
2186static inline bool skwq_has_sleeper(struct socket_wq *wq)
2187{
2188	return wq && wq_has_sleeper(&wq->wait);
2189}
2190
2191/**
2192 * sock_poll_wait - place memory barrier behind the poll_wait call.
2193 * @filp:           file
2194 * @sock:           socket to wait on
2195 * @p:              poll_table
2196 *
2197 * See the comments in the wq_has_sleeper function.
2198 */
2199static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2200				  poll_table *p)
2201{
2202	if (!poll_does_not_wait(p)) {
2203		poll_wait(filp, &sock->wq.wait, p);
2204		/* We need to be sure we are in sync with the
2205		 * socket flags modification.
2206		 *
2207		 * This memory barrier is paired in the wq_has_sleeper.
2208		 */
2209		smp_mb();
2210	}
2211}
2212
2213static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2214{
2215	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
2216	u32 txhash = READ_ONCE(sk->sk_txhash);
2217
2218	if (txhash) {
2219		skb->l4_hash = 1;
2220		skb->hash = txhash;
2221	}
2222}
2223
2224void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2225
2226/*
2227 *	Queue a received datagram if it will fit. Stream and sequenced
2228 *	protocols can't normally use this as they need to fit buffers in
2229 *	and play with them.
2230 *
2231 *	Inlined as it's very short and called for pretty much every
2232 *	packet ever received.
2233 */
2234static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2235{
2236	skb_orphan(skb);
2237	skb->sk = sk;
2238	skb->destructor = sock_rfree;
2239	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2240	sk_mem_charge(sk, skb->truesize);
2241}
2242
2243static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2244{
2245	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2246		skb_orphan(skb);
2247		skb->destructor = sock_efree;
2248		skb->sk = sk;
2249		return true;
2250	}
2251	return false;
2252}
2253
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2254void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2255		    unsigned long expires);
2256
2257void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2258
2259void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2260
2261int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2262			struct sk_buff *skb, unsigned int flags,
2263			void (*destructor)(struct sock *sk,
2264					   struct sk_buff *skb));
2265int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2266int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 
 
 
 
 
 
 
2267
2268int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2269struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2270
2271/*
2272 *	Recover an error report and clear atomically
2273 */
2274
2275static inline int sock_error(struct sock *sk)
2276{
2277	int err;
2278
2279	/* Avoid an atomic operation for the common case.
2280	 * This is racy since another cpu/thread can change sk_err under us.
2281	 */
2282	if (likely(data_race(!sk->sk_err)))
2283		return 0;
2284
2285	err = xchg(&sk->sk_err, 0);
2286	return -err;
2287}
2288
2289void sk_error_report(struct sock *sk);
2290
2291static inline unsigned long sock_wspace(struct sock *sk)
2292{
2293	int amt = 0;
2294
2295	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2296		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2297		if (amt < 0)
2298			amt = 0;
2299	}
2300	return amt;
2301}
2302
2303/* Note:
2304 *  We use sk->sk_wq_raw, from contexts knowing this
2305 *  pointer is not NULL and cannot disappear/change.
2306 */
2307static inline void sk_set_bit(int nr, struct sock *sk)
2308{
2309	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2310	    !sock_flag(sk, SOCK_FASYNC))
2311		return;
2312
2313	set_bit(nr, &sk->sk_wq_raw->flags);
2314}
2315
2316static inline void sk_clear_bit(int nr, struct sock *sk)
2317{
2318	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2319	    !sock_flag(sk, SOCK_FASYNC))
2320		return;
2321
2322	clear_bit(nr, &sk->sk_wq_raw->flags);
2323}
2324
2325static inline void sk_wake_async(const struct sock *sk, int how, int band)
2326{
2327	if (sock_flag(sk, SOCK_FASYNC)) {
2328		rcu_read_lock();
2329		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2330		rcu_read_unlock();
2331	}
2332}
2333
2334/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2335 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2336 * Note: for send buffers, TCP works better if we can build two skbs at
2337 * minimum.
2338 */
2339#define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2340
2341#define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2342#define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2343
2344static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2345{
2346	u32 val;
2347
2348	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2349		return;
2350
2351	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
 
2352
2353	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2354}
2355
2356struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2357				    bool force_schedule);
2358
2359/**
2360 * sk_page_frag - return an appropriate page_frag
2361 * @sk: socket
2362 *
2363 * Use the per task page_frag instead of the per socket one for
2364 * optimization when we know that we're in the normal context and owns
2365 * everything that's associated with %current.
2366 *
2367 * gfpflags_allow_blocking() isn't enough here as direct reclaim may nest
2368 * inside other socket operations and end up recursing into sk_page_frag()
2369 * while it's already in use.
 
2370 *
2371 * Return: a per task page_frag if context allows that,
2372 * otherwise a per socket one.
2373 */
2374static inline struct page_frag *sk_page_frag(struct sock *sk)
2375{
2376	if (gfpflags_normal_context(sk->sk_allocation))
2377		return &current->task_frag;
2378
2379	return &sk->sk_frag;
2380}
2381
2382bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2383
2384/*
2385 *	Default write policy as shown to user space via poll/select/SIGIO
2386 */
2387static inline bool sock_writeable(const struct sock *sk)
2388{
2389	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2390}
2391
2392static inline gfp_t gfp_any(void)
2393{
2394	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2395}
2396
 
 
 
 
 
2397static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2398{
2399	return noblock ? 0 : sk->sk_rcvtimeo;
2400}
2401
2402static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2403{
2404	return noblock ? 0 : sk->sk_sndtimeo;
2405}
2406
2407static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2408{
2409	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2410
2411	return v ?: 1;
2412}
2413
2414/* Alas, with timeout socket operations are not restartable.
2415 * Compare this to poll().
2416 */
2417static inline int sock_intr_errno(long timeo)
2418{
2419	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2420}
2421
2422struct sock_skb_cb {
2423	u32 dropcount;
2424};
2425
2426/* Store sock_skb_cb at the end of skb->cb[] so protocol families
2427 * using skb->cb[] would keep using it directly and utilize its
2428 * alignement guarantee.
2429 */
2430#define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2431			    sizeof(struct sock_skb_cb)))
2432
2433#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2434			    SOCK_SKB_CB_OFFSET))
2435
2436#define sock_skb_cb_check_size(size) \
2437	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2438
2439static inline void
2440sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2441{
2442	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2443						atomic_read(&sk->sk_drops) : 0;
2444}
2445
2446static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2447{
2448	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2449
2450	atomic_add(segs, &sk->sk_drops);
2451}
2452
2453static inline ktime_t sock_read_timestamp(struct sock *sk)
2454{
2455#if BITS_PER_LONG==32
2456	unsigned int seq;
2457	ktime_t kt;
2458
2459	do {
2460		seq = read_seqbegin(&sk->sk_stamp_seq);
2461		kt = sk->sk_stamp;
2462	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2463
2464	return kt;
2465#else
2466	return READ_ONCE(sk->sk_stamp);
2467#endif
2468}
2469
2470static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2471{
2472#if BITS_PER_LONG==32
2473	write_seqlock(&sk->sk_stamp_seq);
2474	sk->sk_stamp = kt;
2475	write_sequnlock(&sk->sk_stamp_seq);
2476#else
2477	WRITE_ONCE(sk->sk_stamp, kt);
2478#endif
2479}
2480
2481void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2482			   struct sk_buff *skb);
2483void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2484			     struct sk_buff *skb);
2485
2486static inline void
2487sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2488{
2489	ktime_t kt = skb->tstamp;
2490	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2491
2492	/*
2493	 * generate control messages if
2494	 * - receive time stamping in software requested
2495	 * - software time stamp available and wanted
2496	 * - hardware time stamps available and wanted
2497	 */
2498	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2499	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2500	    (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2501	    (hwtstamps->hwtstamp &&
2502	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2503		__sock_recv_timestamp(msg, sk, skb);
2504	else
2505		sock_write_timestamp(sk, kt);
2506
2507	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2508		__sock_recv_wifi_status(msg, sk, skb);
2509}
2510
2511void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2512			      struct sk_buff *skb);
2513
2514#define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2515static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2516					  struct sk_buff *skb)
2517{
2518#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)			| \
2519			   (1UL << SOCK_RCVTSTAMP))
 
2520#define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2521			   SOF_TIMESTAMPING_RAW_HARDWARE)
2522
2523	if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2524		__sock_recv_ts_and_drops(msg, sk, skb);
2525	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2526		sock_write_timestamp(sk, skb->tstamp);
2527	else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2528		sock_write_timestamp(sk, 0);
2529}
2530
2531void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2532
2533/**
2534 * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2535 * @sk:		socket sending this packet
2536 * @tsflags:	timestamping flags to use
2537 * @tx_flags:	completed with instructions for time stamping
2538 * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2539 *
2540 * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2541 */
2542static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2543				      __u8 *tx_flags, __u32 *tskey)
2544{
2545	if (unlikely(tsflags)) {
2546		__sock_tx_timestamp(tsflags, tx_flags);
2547		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2548		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2549			*tskey = sk->sk_tskey++;
2550	}
2551	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2552		*tx_flags |= SKBTX_WIFI_STATUS;
2553}
2554
2555static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2556				     __u8 *tx_flags)
2557{
2558	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2559}
2560
2561static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2562{
2563	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2564			   &skb_shinfo(skb)->tskey);
2565}
2566
2567DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
 
 
 
 
2568/**
2569 * sk_eat_skb - Release a skb if it is no longer needed
2570 * @sk: socket to eat this skb from
2571 * @skb: socket buffer to eat
2572 *
2573 * This routine must be called with interrupts disabled or with the socket
2574 * locked so that the sk_buff queue operation is ok.
2575*/
2576static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2577{
2578	__skb_unlink(skb, &sk->sk_receive_queue);
2579	if (static_branch_unlikely(&tcp_rx_skb_cache_key) &&
2580	    !sk->sk_rx_skb_cache) {
2581		sk->sk_rx_skb_cache = skb;
2582		skb_orphan(skb);
2583		return;
2584	}
2585	__kfree_skb(skb);
2586}
2587
2588static inline
2589struct net *sock_net(const struct sock *sk)
2590{
2591	return read_pnet(&sk->sk_net);
2592}
2593
2594static inline
2595void sock_net_set(struct sock *sk, struct net *net)
2596{
2597	write_pnet(&sk->sk_net, net);
2598}
2599
2600static inline bool
2601skb_sk_is_prefetched(struct sk_buff *skb)
2602{
2603#ifdef CONFIG_INET
2604	return skb->destructor == sock_pfree;
2605#else
2606	return false;
2607#endif /* CONFIG_INET */
2608}
2609
2610/* This helper checks if a socket is a full socket,
2611 * ie _not_ a timewait or request socket.
2612 */
2613static inline bool sk_fullsock(const struct sock *sk)
2614{
2615	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2616}
2617
2618static inline bool
2619sk_is_refcounted(struct sock *sk)
2620{
2621	/* Only full sockets have sk->sk_flags. */
2622	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2623}
2624
2625/**
2626 * skb_steal_sock - steal a socket from an sk_buff
2627 * @skb: sk_buff to steal the socket from
2628 * @refcounted: is set to true if the socket is reference-counted
2629 */
2630static inline struct sock *
2631skb_steal_sock(struct sk_buff *skb, bool *refcounted)
2632{
2633	if (skb->sk) {
2634		struct sock *sk = skb->sk;
2635
2636		*refcounted = true;
2637		if (skb_sk_is_prefetched(skb))
2638			*refcounted = sk_is_refcounted(sk);
2639		skb->destructor = NULL;
2640		skb->sk = NULL;
2641		return sk;
2642	}
2643	*refcounted = false;
2644	return NULL;
2645}
2646
2647/* Checks if this SKB belongs to an HW offloaded socket
2648 * and whether any SW fallbacks are required based on dev.
2649 * Check decrypted mark in case skb_orphan() cleared socket.
2650 */
2651static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2652						   struct net_device *dev)
2653{
2654#ifdef CONFIG_SOCK_VALIDATE_XMIT
2655	struct sock *sk = skb->sk;
2656
2657	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2658		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2659#ifdef CONFIG_TLS_DEVICE
2660	} else if (unlikely(skb->decrypted)) {
2661		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2662		kfree_skb(skb);
2663		skb = NULL;
2664#endif
2665	}
2666#endif
2667
2668	return skb;
2669}
2670
2671/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2672 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2673 */
2674static inline bool sk_listener(const struct sock *sk)
2675{
2676	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2677}
2678
2679void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2680int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2681		       int type);
2682
2683bool sk_ns_capable(const struct sock *sk,
2684		   struct user_namespace *user_ns, int cap);
2685bool sk_capable(const struct sock *sk, int cap);
2686bool sk_net_capable(const struct sock *sk, int cap);
2687
2688void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2689
2690/* Take into consideration the size of the struct sk_buff overhead in the
2691 * determination of these values, since that is non-constant across
2692 * platforms.  This makes socket queueing behavior and performance
2693 * not depend upon such differences.
2694 */
2695#define _SK_MEM_PACKETS		256
2696#define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
2697#define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2698#define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2699
2700extern __u32 sysctl_wmem_max;
2701extern __u32 sysctl_rmem_max;
2702
2703extern int sysctl_tstamp_allow_data;
2704extern int sysctl_optmem_max;
2705
2706extern __u32 sysctl_wmem_default;
2707extern __u32 sysctl_rmem_default;
2708
 
2709DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2710
2711static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2712{
2713	/* Does this proto have per netns sysctl_wmem ? */
2714	if (proto->sysctl_wmem_offset)
2715		return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2716
2717	return *proto->sysctl_wmem;
2718}
2719
2720static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2721{
2722	/* Does this proto have per netns sysctl_rmem ? */
2723	if (proto->sysctl_rmem_offset)
2724		return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2725
2726	return *proto->sysctl_rmem;
2727}
2728
2729/* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2730 * Some wifi drivers need to tweak it to get more chunks.
2731 * They can use this helper from their ndo_start_xmit()
2732 */
2733static inline void sk_pacing_shift_update(struct sock *sk, int val)
2734{
2735	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2736		return;
2737	WRITE_ONCE(sk->sk_pacing_shift, val);
2738}
2739
2740/* if a socket is bound to a device, check that the given device
2741 * index is either the same or that the socket is bound to an L3
2742 * master device and the given device index is also enslaved to
2743 * that L3 master
2744 */
2745static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2746{
 
2747	int mdif;
2748
2749	if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2750		return true;
2751
2752	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2753	if (mdif && mdif == sk->sk_bound_dev_if)
2754		return true;
2755
2756	return false;
2757}
2758
2759void sock_def_readable(struct sock *sk);
2760
2761int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
2762void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
2763int sock_set_timestamping(struct sock *sk, int optname,
2764			  struct so_timestamping timestamping);
2765
2766void sock_enable_timestamps(struct sock *sk);
2767void sock_no_linger(struct sock *sk);
2768void sock_set_keepalive(struct sock *sk);
2769void sock_set_priority(struct sock *sk, u32 priority);
2770void sock_set_rcvbuf(struct sock *sk, int val);
2771void sock_set_mark(struct sock *sk, u32 val);
2772void sock_set_reuseaddr(struct sock *sk);
2773void sock_set_reuseport(struct sock *sk);
2774void sock_set_sndtimeo(struct sock *sk, s64 secs);
2775
2776int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
2777
 
 
 
 
 
 
 
 
 
 
2778#endif	/* _SOCK_H */
v6.2
   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
   4 *		operating system.  INET is implemented using the  BSD Socket
   5 *		interface as the means of communication with the user level.
   6 *
   7 *		Definitions for the AF_INET socket handler.
   8 *
   9 * Version:	@(#)sock.h	1.0.4	05/13/93
  10 *
  11 * Authors:	Ross Biro
  12 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  13 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
  14 *		Florian La Roche <flla@stud.uni-sb.de>
  15 *
  16 * Fixes:
  17 *		Alan Cox	:	Volatiles in skbuff pointers. See
  18 *					skbuff comments. May be overdone,
  19 *					better to prove they can be removed
  20 *					than the reverse.
  21 *		Alan Cox	:	Added a zapped field for tcp to note
  22 *					a socket is reset and must stay shut up
  23 *		Alan Cox	:	New fields for options
  24 *	Pauline Middelink	:	identd support
  25 *		Alan Cox	:	Eliminate low level recv/recvfrom
  26 *		David S. Miller	:	New socket lookup architecture.
  27 *              Steve Whitehouse:       Default routines for sock_ops
  28 *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
  29 *              			protinfo be just a void pointer, as the
  30 *              			protocol specific parts were moved to
  31 *              			respective headers and ipv4/v6, etc now
  32 *              			use private slabcaches for its socks
  33 *              Pedro Hortas	:	New flags field for socket options
  34 */
  35#ifndef _SOCK_H
  36#define _SOCK_H
  37
  38#include <linux/hardirq.h>
  39#include <linux/kernel.h>
  40#include <linux/list.h>
  41#include <linux/list_nulls.h>
  42#include <linux/timer.h>
  43#include <linux/cache.h>
  44#include <linux/bitops.h>
  45#include <linux/lockdep.h>
  46#include <linux/netdevice.h>
  47#include <linux/skbuff.h>	/* struct sk_buff */
  48#include <linux/mm.h>
  49#include <linux/security.h>
  50#include <linux/slab.h>
  51#include <linux/uaccess.h>
  52#include <linux/page_counter.h>
  53#include <linux/memcontrol.h>
  54#include <linux/static_key.h>
  55#include <linux/sched.h>
  56#include <linux/wait.h>
  57#include <linux/cgroup-defs.h>
  58#include <linux/rbtree.h>
 
  59#include <linux/rculist_nulls.h>
  60#include <linux/poll.h>
  61#include <linux/sockptr.h>
  62#include <linux/indirect_call_wrapper.h>
  63#include <linux/atomic.h>
  64#include <linux/refcount.h>
  65#include <linux/llist.h>
  66#include <net/dst.h>
  67#include <net/checksum.h>
  68#include <net/tcp_states.h>
  69#include <linux/net_tstamp.h>
  70#include <net/l3mdev.h>
  71#include <uapi/linux/socket.h>
  72
  73/*
  74 * This structure really needs to be cleaned up.
  75 * Most of it is for TCP, and not used by any of
  76 * the other protocols.
  77 */
  78
  79/* Define this to get the SOCK_DBG debugging facility. */
  80#define SOCK_DEBUGGING
  81#ifdef SOCK_DEBUGGING
  82#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
  83					printk(KERN_DEBUG msg); } while (0)
  84#else
  85/* Validate arguments and do nothing */
  86static inline __printf(2, 3)
  87void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
  88{
  89}
  90#endif
  91
  92/* This is the per-socket lock.  The spinlock provides a synchronization
  93 * between user contexts and software interrupt processing, whereas the
  94 * mini-semaphore synchronizes multiple users amongst themselves.
  95 */
  96typedef struct {
  97	spinlock_t		slock;
  98	int			owned;
  99	wait_queue_head_t	wq;
 100	/*
 101	 * We express the mutex-alike socket_lock semantics
 102	 * to the lock validator by explicitly managing
 103	 * the slock as a lock variant (in addition to
 104	 * the slock itself):
 105	 */
 106#ifdef CONFIG_DEBUG_LOCK_ALLOC
 107	struct lockdep_map dep_map;
 108#endif
 109} socket_lock_t;
 110
 111struct sock;
 112struct proto;
 113struct net;
 114
 115typedef __u32 __bitwise __portpair;
 116typedef __u64 __bitwise __addrpair;
 117
 118/**
 119 *	struct sock_common - minimal network layer representation of sockets
 120 *	@skc_daddr: Foreign IPv4 addr
 121 *	@skc_rcv_saddr: Bound local IPv4 addr
 122 *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
 123 *	@skc_hash: hash value used with various protocol lookup tables
 124 *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
 125 *	@skc_dport: placeholder for inet_dport/tw_dport
 126 *	@skc_num: placeholder for inet_num/tw_num
 127 *	@skc_portpair: __u32 union of @skc_dport & @skc_num
 128 *	@skc_family: network address family
 129 *	@skc_state: Connection state
 130 *	@skc_reuse: %SO_REUSEADDR setting
 131 *	@skc_reuseport: %SO_REUSEPORT setting
 132 *	@skc_ipv6only: socket is IPV6 only
 133 *	@skc_net_refcnt: socket is using net ref counting
 134 *	@skc_bound_dev_if: bound device index if != 0
 135 *	@skc_bind_node: bind hash linkage for various protocol lookup tables
 136 *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
 137 *	@skc_prot: protocol handlers inside a network family
 138 *	@skc_net: reference to the network namespace of this socket
 139 *	@skc_v6_daddr: IPV6 destination address
 140 *	@skc_v6_rcv_saddr: IPV6 source address
 141 *	@skc_cookie: socket's cookie value
 142 *	@skc_node: main hash linkage for various protocol lookup tables
 143 *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
 144 *	@skc_tx_queue_mapping: tx queue number for this connection
 145 *	@skc_rx_queue_mapping: rx queue number for this connection
 146 *	@skc_flags: place holder for sk_flags
 147 *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
 148 *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
 149 *	@skc_listener: connection request listener socket (aka rsk_listener)
 150 *		[union with @skc_flags]
 151 *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
 152 *		[union with @skc_flags]
 153 *	@skc_incoming_cpu: record/match cpu processing incoming packets
 154 *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
 155 *		[union with @skc_incoming_cpu]
 156 *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
 157 *		[union with @skc_incoming_cpu]
 158 *	@skc_refcnt: reference count
 159 *
 160 *	This is the minimal network layer representation of sockets, the header
 161 *	for struct sock and struct inet_timewait_sock.
 162 */
 163struct sock_common {
 
 
 
 164	union {
 165		__addrpair	skc_addrpair;
 166		struct {
 167			__be32	skc_daddr;
 168			__be32	skc_rcv_saddr;
 169		};
 170	};
 171	union  {
 172		unsigned int	skc_hash;
 173		__u16		skc_u16hashes[2];
 174	};
 175	/* skc_dport && skc_num must be grouped as well */
 176	union {
 177		__portpair	skc_portpair;
 178		struct {
 179			__be16	skc_dport;
 180			__u16	skc_num;
 181		};
 182	};
 183
 184	unsigned short		skc_family;
 185	volatile unsigned char	skc_state;
 186	unsigned char		skc_reuse:4;
 187	unsigned char		skc_reuseport:1;
 188	unsigned char		skc_ipv6only:1;
 189	unsigned char		skc_net_refcnt:1;
 190	int			skc_bound_dev_if;
 191	union {
 192		struct hlist_node	skc_bind_node;
 193		struct hlist_node	skc_portaddr_node;
 194	};
 195	struct proto		*skc_prot;
 196	possible_net_t		skc_net;
 197
 198#if IS_ENABLED(CONFIG_IPV6)
 199	struct in6_addr		skc_v6_daddr;
 200	struct in6_addr		skc_v6_rcv_saddr;
 201#endif
 202
 203	atomic64_t		skc_cookie;
 204
 205	/* following fields are padding to force
 206	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
 207	 * assuming IPV6 is enabled. We use this padding differently
 208	 * for different kind of 'sockets'
 209	 */
 210	union {
 211		unsigned long	skc_flags;
 212		struct sock	*skc_listener; /* request_sock */
 213		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
 214	};
 215	/*
 216	 * fields between dontcopy_begin/dontcopy_end
 217	 * are not copied in sock_copy()
 218	 */
 219	/* private: */
 220	int			skc_dontcopy_begin[0];
 221	/* public: */
 222	union {
 223		struct hlist_node	skc_node;
 224		struct hlist_nulls_node skc_nulls_node;
 225	};
 226	unsigned short		skc_tx_queue_mapping;
 227#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
 228	unsigned short		skc_rx_queue_mapping;
 229#endif
 230	union {
 231		int		skc_incoming_cpu;
 232		u32		skc_rcv_wnd;
 233		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
 234	};
 235
 236	refcount_t		skc_refcnt;
 237	/* private: */
 238	int                     skc_dontcopy_end[0];
 239	union {
 240		u32		skc_rxhash;
 241		u32		skc_window_clamp;
 242		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
 243	};
 244	/* public: */
 245};
 246
 247struct bpf_local_storage;
 248struct sk_filter;
 249
 250/**
 251  *	struct sock - network layer representation of sockets
 252  *	@__sk_common: shared layout with inet_timewait_sock
 253  *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
 254  *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
 255  *	@sk_lock:	synchronizer
 256  *	@sk_kern_sock: True if sock is using kernel lock classes
 257  *	@sk_rcvbuf: size of receive buffer in bytes
 258  *	@sk_wq: sock wait queue and async head
 259  *	@sk_rx_dst: receive input route used by early demux
 260  *	@sk_rx_dst_ifindex: ifindex for @sk_rx_dst
 261  *	@sk_rx_dst_cookie: cookie for @sk_rx_dst
 262  *	@sk_dst_cache: destination cache
 263  *	@sk_dst_pending_confirm: need to confirm neighbour
 264  *	@sk_policy: flow policy
 
 265  *	@sk_receive_queue: incoming packets
 266  *	@sk_wmem_alloc: transmit queue bytes committed
 267  *	@sk_tsq_flags: TCP Small Queues flags
 268  *	@sk_write_queue: Packet sending queue
 269  *	@sk_omem_alloc: "o" is "option" or "other"
 270  *	@sk_wmem_queued: persistent queue size
 271  *	@sk_forward_alloc: space allocated forward
 272  *	@sk_reserved_mem: space reserved and non-reclaimable for the socket
 273  *	@sk_napi_id: id of the last napi context to receive data for sk
 274  *	@sk_ll_usec: usecs to busypoll when there is no data
 275  *	@sk_allocation: allocation mode
 276  *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
 277  *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
 278  *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
 279  *	@sk_sndbuf: size of send buffer in bytes
 280  *	@__sk_flags_offset: empty field used to determine location of bitfield
 281  *	@sk_padding: unused element for alignment
 282  *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
 283  *	@sk_no_check_rx: allow zero checksum in RX packets
 284  *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
 285  *	@sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
 
 
 286  *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
 287  *	@sk_gso_max_size: Maximum GSO segment size to build
 288  *	@sk_gso_max_segs: Maximum number of GSO segments
 289  *	@sk_pacing_shift: scaling factor for TCP Small Queues
 290  *	@sk_lingertime: %SO_LINGER l_linger setting
 291  *	@sk_backlog: always used with the per-socket spinlock held
 292  *	@sk_callback_lock: used with the callbacks in the end of this struct
 293  *	@sk_error_queue: rarely used
 294  *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
 295  *			  IPV6_ADDRFORM for instance)
 296  *	@sk_err: last error
 297  *	@sk_err_soft: errors that don't cause failure but are the cause of a
 298  *		      persistent failure not just 'timed out'
 299  *	@sk_drops: raw/udp drops counter
 300  *	@sk_ack_backlog: current listen backlog
 301  *	@sk_max_ack_backlog: listen backlog set in listen()
 302  *	@sk_uid: user id of owner
 303  *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
 304  *	@sk_busy_poll_budget: napi processing budget when busypolling
 305  *	@sk_priority: %SO_PRIORITY setting
 306  *	@sk_type: socket type (%SOCK_STREAM, etc)
 307  *	@sk_protocol: which protocol this socket belongs in this network family
 308  *	@sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred
 309  *	@sk_peer_pid: &struct pid for this socket's peer
 310  *	@sk_peer_cred: %SO_PEERCRED setting
 311  *	@sk_rcvlowat: %SO_RCVLOWAT setting
 312  *	@sk_rcvtimeo: %SO_RCVTIMEO setting
 313  *	@sk_sndtimeo: %SO_SNDTIMEO setting
 314  *	@sk_txhash: computed flow hash for use on transmit
 315  *	@sk_txrehash: enable TX hash rethink
 316  *	@sk_filter: socket filtering instructions
 317  *	@sk_timer: sock cleanup timer
 318  *	@sk_stamp: time stamp of last packet received
 319  *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
 320  *	@sk_tsflags: SO_TIMESTAMPING flags
 321  *	@sk_use_task_frag: allow sk_page_frag() to use current->task_frag.
 322  *			   Sockets that can be used under memory reclaim should
 323  *			   set this to false.
 324  *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
 325  *	              for timestamping
 326  *	@sk_tskey: counter to disambiguate concurrent tstamp requests
 327  *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
 328  *	@sk_socket: Identd and reporting IO signals
 329  *	@sk_user_data: RPC layer private data. Write-protected by @sk_callback_lock.
 330  *	@sk_frag: cached page frag
 331  *	@sk_peek_off: current peek_offset value
 332  *	@sk_send_head: front of stuff to transmit
 333  *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
 
 334  *	@sk_security: used by security modules
 335  *	@sk_mark: generic packet mark
 336  *	@sk_cgrp_data: cgroup data for this cgroup
 337  *	@sk_memcg: this socket's memory cgroup association
 338  *	@sk_write_pending: a write to stream socket waits to start
 339  *	@sk_state_change: callback to indicate change in the state of the sock
 340  *	@sk_data_ready: callback to indicate there is data to be processed
 341  *	@sk_write_space: callback to indicate there is bf sending space available
 342  *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
 343  *	@sk_backlog_rcv: callback to process the backlog
 344  *	@sk_validate_xmit_skb: ptr to an optional validate function
 345  *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
 346  *	@sk_reuseport_cb: reuseport group container
 347  *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
 348  *	@sk_rcu: used during RCU grace period
 349  *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
 350  *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
 351  *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
 352  *	@sk_txtime_unused: unused txtime flags
 353  *	@ns_tracker: tracker for netns reference
 354  *	@sk_bind2_node: bind node in the bhash2 table
 355  */
 356struct sock {
 357	/*
 358	 * Now struct inet_timewait_sock also uses sock_common, so please just
 359	 * don't add nothing before this first member (__sk_common) --acme
 360	 */
 361	struct sock_common	__sk_common;
 362#define sk_node			__sk_common.skc_node
 363#define sk_nulls_node		__sk_common.skc_nulls_node
 364#define sk_refcnt		__sk_common.skc_refcnt
 365#define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
 366#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
 367#define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
 368#endif
 369
 370#define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
 371#define sk_dontcopy_end		__sk_common.skc_dontcopy_end
 372#define sk_hash			__sk_common.skc_hash
 373#define sk_portpair		__sk_common.skc_portpair
 374#define sk_num			__sk_common.skc_num
 375#define sk_dport		__sk_common.skc_dport
 376#define sk_addrpair		__sk_common.skc_addrpair
 377#define sk_daddr		__sk_common.skc_daddr
 378#define sk_rcv_saddr		__sk_common.skc_rcv_saddr
 379#define sk_family		__sk_common.skc_family
 380#define sk_state		__sk_common.skc_state
 381#define sk_reuse		__sk_common.skc_reuse
 382#define sk_reuseport		__sk_common.skc_reuseport
 383#define sk_ipv6only		__sk_common.skc_ipv6only
 384#define sk_net_refcnt		__sk_common.skc_net_refcnt
 385#define sk_bound_dev_if		__sk_common.skc_bound_dev_if
 386#define sk_bind_node		__sk_common.skc_bind_node
 387#define sk_prot			__sk_common.skc_prot
 388#define sk_net			__sk_common.skc_net
 389#define sk_v6_daddr		__sk_common.skc_v6_daddr
 390#define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
 391#define sk_cookie		__sk_common.skc_cookie
 392#define sk_incoming_cpu		__sk_common.skc_incoming_cpu
 393#define sk_flags		__sk_common.skc_flags
 394#define sk_rxhash		__sk_common.skc_rxhash
 395
 396	/* early demux fields */
 397	struct dst_entry __rcu	*sk_rx_dst;
 398	int			sk_rx_dst_ifindex;
 399	u32			sk_rx_dst_cookie;
 400
 401	socket_lock_t		sk_lock;
 402	atomic_t		sk_drops;
 403	int			sk_rcvlowat;
 404	struct sk_buff_head	sk_error_queue;
 
 405	struct sk_buff_head	sk_receive_queue;
 406	/*
 407	 * The backlog queue is special, it is always used with
 408	 * the per-socket spinlock held and requires low latency
 409	 * access. Therefore we special case it's implementation.
 410	 * Note : rmem_alloc is in this structure to fill a hole
 411	 * on 64bit arches, not because its logically part of
 412	 * backlog.
 413	 */
 414	struct {
 415		atomic_t	rmem_alloc;
 416		int		len;
 417		struct sk_buff	*head;
 418		struct sk_buff	*tail;
 419	} sk_backlog;
 420
 421#define sk_rmem_alloc sk_backlog.rmem_alloc
 422
 423	int			sk_forward_alloc;
 424	u32			sk_reserved_mem;
 425#ifdef CONFIG_NET_RX_BUSY_POLL
 426	unsigned int		sk_ll_usec;
 427	/* ===== mostly read cache line ===== */
 428	unsigned int		sk_napi_id;
 429#endif
 430	int			sk_rcvbuf;
 431
 432	struct sk_filter __rcu	*sk_filter;
 433	union {
 434		struct socket_wq __rcu	*sk_wq;
 435		/* private: */
 436		struct socket_wq	*sk_wq_raw;
 437		/* public: */
 438	};
 439#ifdef CONFIG_XFRM
 440	struct xfrm_policy __rcu *sk_policy[2];
 441#endif
 442
 443	struct dst_entry __rcu	*sk_dst_cache;
 444	atomic_t		sk_omem_alloc;
 445	int			sk_sndbuf;
 446
 447	/* ===== cache line for TX ===== */
 448	int			sk_wmem_queued;
 449	refcount_t		sk_wmem_alloc;
 450	unsigned long		sk_tsq_flags;
 451	union {
 452		struct sk_buff	*sk_send_head;
 453		struct rb_root	tcp_rtx_queue;
 454	};
 
 455	struct sk_buff_head	sk_write_queue;
 456	__s32			sk_peek_off;
 457	int			sk_write_pending;
 458	__u32			sk_dst_pending_confirm;
 459	u32			sk_pacing_status; /* see enum sk_pacing */
 460	long			sk_sndtimeo;
 461	struct timer_list	sk_timer;
 462	__u32			sk_priority;
 463	__u32			sk_mark;
 464	unsigned long		sk_pacing_rate; /* bytes per second */
 465	unsigned long		sk_max_pacing_rate;
 466	struct page_frag	sk_frag;
 467	netdev_features_t	sk_route_caps;
 
 
 468	int			sk_gso_type;
 469	unsigned int		sk_gso_max_size;
 470	gfp_t			sk_allocation;
 471	__u32			sk_txhash;
 472
 473	/*
 474	 * Because of non atomicity rules, all
 475	 * changes are protected by socket lock.
 476	 */
 477	u8			sk_gso_disabled : 1,
 478				sk_kern_sock : 1,
 479				sk_no_check_tx : 1,
 480				sk_no_check_rx : 1,
 481				sk_userlocks : 4;
 482	u8			sk_pacing_shift;
 483	u16			sk_type;
 484	u16			sk_protocol;
 485	u16			sk_gso_max_segs;
 486	unsigned long	        sk_lingertime;
 487	struct proto		*sk_prot_creator;
 488	rwlock_t		sk_callback_lock;
 489	int			sk_err,
 490				sk_err_soft;
 491	u32			sk_ack_backlog;
 492	u32			sk_max_ack_backlog;
 493	kuid_t			sk_uid;
 494	u8			sk_txrehash;
 495#ifdef CONFIG_NET_RX_BUSY_POLL
 496	u8			sk_prefer_busy_poll;
 497	u16			sk_busy_poll_budget;
 498#endif
 499	spinlock_t		sk_peer_lock;
 500	int			sk_bind_phc;
 501	struct pid		*sk_peer_pid;
 502	const struct cred	*sk_peer_cred;
 503
 504	long			sk_rcvtimeo;
 505	ktime_t			sk_stamp;
 506#if BITS_PER_LONG==32
 507	seqlock_t		sk_stamp_seq;
 508#endif
 509	atomic_t		sk_tskey;
 
 
 
 510	atomic_t		sk_zckey;
 511	u32			sk_tsflags;
 512	u8			sk_shutdown;
 513
 514	u8			sk_clockid;
 515	u8			sk_txtime_deadline_mode : 1,
 516				sk_txtime_report_errors : 1,
 517				sk_txtime_unused : 6;
 518	bool			sk_use_task_frag;
 519
 520	struct socket		*sk_socket;
 521	void			*sk_user_data;
 522#ifdef CONFIG_SECURITY
 523	void			*sk_security;
 524#endif
 525	struct sock_cgroup_data	sk_cgrp_data;
 526	struct mem_cgroup	*sk_memcg;
 527	void			(*sk_state_change)(struct sock *sk);
 528	void			(*sk_data_ready)(struct sock *sk);
 529	void			(*sk_write_space)(struct sock *sk);
 530	void			(*sk_error_report)(struct sock *sk);
 531	int			(*sk_backlog_rcv)(struct sock *sk,
 532						  struct sk_buff *skb);
 533#ifdef CONFIG_SOCK_VALIDATE_XMIT
 534	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
 535							struct net_device *dev,
 536							struct sk_buff *skb);
 537#endif
 538	void                    (*sk_destruct)(struct sock *sk);
 539	struct sock_reuseport __rcu	*sk_reuseport_cb;
 540#ifdef CONFIG_BPF_SYSCALL
 541	struct bpf_local_storage __rcu	*sk_bpf_storage;
 542#endif
 543	struct rcu_head		sk_rcu;
 544	netns_tracker		ns_tracker;
 545	struct hlist_node	sk_bind2_node;
 546};
 547
 548enum sk_pacing {
 549	SK_PACING_NONE		= 0,
 550	SK_PACING_NEEDED	= 1,
 551	SK_PACING_FQ		= 2,
 552};
 553
 554/* flag bits in sk_user_data
 555 *
 556 * - SK_USER_DATA_NOCOPY:      Pointer stored in sk_user_data might
 557 *   not be suitable for copying when cloning the socket. For instance,
 558 *   it can point to a reference counted object. sk_user_data bottom
 559 *   bit is set if pointer must not be copied.
 560 *
 561 * - SK_USER_DATA_BPF:         Mark whether sk_user_data field is
 562 *   managed/owned by a BPF reuseport array. This bit should be set
 563 *   when sk_user_data's sk is added to the bpf's reuseport_array.
 564 *
 565 * - SK_USER_DATA_PSOCK:       Mark whether pointer stored in
 566 *   sk_user_data points to psock type. This bit should be set
 567 *   when sk_user_data is assigned to a psock object.
 568 */
 569#define SK_USER_DATA_NOCOPY	1UL
 570#define SK_USER_DATA_BPF	2UL
 571#define SK_USER_DATA_PSOCK	4UL
 572#define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
 573				  SK_USER_DATA_PSOCK)
 574
 575/**
 576 * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
 577 * @sk: socket
 578 */
 579static inline bool sk_user_data_is_nocopy(const struct sock *sk)
 580{
 581	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
 582}
 583
 584#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
 585
 586/**
 587 * __locked_read_sk_user_data_with_flags - return the pointer
 588 * only if argument flags all has been set in sk_user_data. Otherwise
 589 * return NULL
 590 *
 591 * @sk: socket
 592 * @flags: flag bits
 593 *
 594 * The caller must be holding sk->sk_callback_lock.
 595 */
 596static inline void *
 597__locked_read_sk_user_data_with_flags(const struct sock *sk,
 598				      uintptr_t flags)
 599{
 600	uintptr_t sk_user_data =
 601		(uintptr_t)rcu_dereference_check(__sk_user_data(sk),
 602						 lockdep_is_held(&sk->sk_callback_lock));
 603
 604	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
 605
 606	if ((sk_user_data & flags) == flags)
 607		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
 608	return NULL;
 609}
 610
 611/**
 612 * __rcu_dereference_sk_user_data_with_flags - return the pointer
 613 * only if argument flags all has been set in sk_user_data. Otherwise
 614 * return NULL
 615 *
 616 * @sk: socket
 617 * @flags: flag bits
 618 */
 619static inline void *
 620__rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
 621					  uintptr_t flags)
 622{
 623	uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
 624
 625	WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
 626
 627	if ((sk_user_data & flags) == flags)
 628		return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
 629	return NULL;
 630}
 631
 632#define rcu_dereference_sk_user_data(sk)				\
 633	__rcu_dereference_sk_user_data_with_flags(sk, 0)
 634#define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags)		\
 635({									\
 636	uintptr_t __tmp1 = (uintptr_t)(ptr),				\
 637		  __tmp2 = (uintptr_t)(flags);				\
 638	WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK);			\
 639	WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK);			\
 
 
 
 
 
 
 
 
 
 640	rcu_assign_pointer(__sk_user_data((sk)),			\
 641			   __tmp1 | __tmp2);				\
 642})
 643#define rcu_assign_sk_user_data(sk, ptr)				\
 644	__rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
 645
 646static inline
 647struct net *sock_net(const struct sock *sk)
 648{
 649	return read_pnet(&sk->sk_net);
 650}
 651
 652static inline
 653void sock_net_set(struct sock *sk, struct net *net)
 654{
 655	write_pnet(&sk->sk_net, net);
 656}
 657
 658/*
 659 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
 660 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
 661 * on a socket means that the socket will reuse everybody else's port
 662 * without looking at the other's sk_reuse value.
 663 */
 664
 665#define SK_NO_REUSE	0
 666#define SK_CAN_REUSE	1
 667#define SK_FORCE_REUSE	2
 668
 669int sk_set_peek_off(struct sock *sk, int val);
 670
 671static inline int sk_peek_offset(const struct sock *sk, int flags)
 672{
 673	if (unlikely(flags & MSG_PEEK)) {
 674		return READ_ONCE(sk->sk_peek_off);
 675	}
 676
 677	return 0;
 678}
 679
 680static inline void sk_peek_offset_bwd(struct sock *sk, int val)
 681{
 682	s32 off = READ_ONCE(sk->sk_peek_off);
 683
 684	if (unlikely(off >= 0)) {
 685		off = max_t(s32, off - val, 0);
 686		WRITE_ONCE(sk->sk_peek_off, off);
 687	}
 688}
 689
 690static inline void sk_peek_offset_fwd(struct sock *sk, int val)
 691{
 692	sk_peek_offset_bwd(sk, -val);
 693}
 694
 695/*
 696 * Hashed lists helper routines
 697 */
 698static inline struct sock *sk_entry(const struct hlist_node *node)
 699{
 700	return hlist_entry(node, struct sock, sk_node);
 701}
 702
 703static inline struct sock *__sk_head(const struct hlist_head *head)
 704{
 705	return hlist_entry(head->first, struct sock, sk_node);
 706}
 707
 708static inline struct sock *sk_head(const struct hlist_head *head)
 709{
 710	return hlist_empty(head) ? NULL : __sk_head(head);
 711}
 712
 713static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
 714{
 715	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
 716}
 717
 718static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
 719{
 720	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
 721}
 722
 723static inline struct sock *sk_next(const struct sock *sk)
 724{
 725	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
 726}
 727
 728static inline struct sock *sk_nulls_next(const struct sock *sk)
 729{
 730	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
 731		hlist_nulls_entry(sk->sk_nulls_node.next,
 732				  struct sock, sk_nulls_node) :
 733		NULL;
 734}
 735
 736static inline bool sk_unhashed(const struct sock *sk)
 737{
 738	return hlist_unhashed(&sk->sk_node);
 739}
 740
 741static inline bool sk_hashed(const struct sock *sk)
 742{
 743	return !sk_unhashed(sk);
 744}
 745
 746static inline void sk_node_init(struct hlist_node *node)
 747{
 748	node->pprev = NULL;
 749}
 750
 
 
 
 
 
 751static inline void __sk_del_node(struct sock *sk)
 752{
 753	__hlist_del(&sk->sk_node);
 754}
 755
 756/* NB: equivalent to hlist_del_init_rcu */
 757static inline bool __sk_del_node_init(struct sock *sk)
 758{
 759	if (sk_hashed(sk)) {
 760		__sk_del_node(sk);
 761		sk_node_init(&sk->sk_node);
 762		return true;
 763	}
 764	return false;
 765}
 766
 767/* Grab socket reference count. This operation is valid only
 768   when sk is ALREADY grabbed f.e. it is found in hash table
 769   or a list and the lookup is made under lock preventing hash table
 770   modifications.
 771 */
 772
 773static __always_inline void sock_hold(struct sock *sk)
 774{
 775	refcount_inc(&sk->sk_refcnt);
 776}
 777
 778/* Ungrab socket in the context, which assumes that socket refcnt
 779   cannot hit zero, f.e. it is true in context of any socketcall.
 780 */
 781static __always_inline void __sock_put(struct sock *sk)
 782{
 783	refcount_dec(&sk->sk_refcnt);
 784}
 785
 786static inline bool sk_del_node_init(struct sock *sk)
 787{
 788	bool rc = __sk_del_node_init(sk);
 789
 790	if (rc) {
 791		/* paranoid for a while -acme */
 792		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
 793		__sock_put(sk);
 794	}
 795	return rc;
 796}
 797#define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
 798
 799static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
 800{
 801	if (sk_hashed(sk)) {
 802		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
 803		return true;
 804	}
 805	return false;
 806}
 807
 808static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
 809{
 810	bool rc = __sk_nulls_del_node_init_rcu(sk);
 811
 812	if (rc) {
 813		/* paranoid for a while -acme */
 814		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
 815		__sock_put(sk);
 816	}
 817	return rc;
 818}
 819
 820static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
 821{
 822	hlist_add_head(&sk->sk_node, list);
 823}
 824
 825static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
 826{
 827	sock_hold(sk);
 828	__sk_add_node(sk, list);
 829}
 830
 831static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
 832{
 833	sock_hold(sk);
 834	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
 835	    sk->sk_family == AF_INET6)
 836		hlist_add_tail_rcu(&sk->sk_node, list);
 837	else
 838		hlist_add_head_rcu(&sk->sk_node, list);
 839}
 840
 841static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
 842{
 843	sock_hold(sk);
 844	hlist_add_tail_rcu(&sk->sk_node, list);
 845}
 846
 847static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 848{
 849	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
 850}
 851
 852static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
 853{
 854	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
 855}
 856
 857static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 858{
 859	sock_hold(sk);
 860	__sk_nulls_add_node_rcu(sk, list);
 861}
 862
 863static inline void __sk_del_bind_node(struct sock *sk)
 864{
 865	__hlist_del(&sk->sk_bind_node);
 866}
 867
 868static inline void sk_add_bind_node(struct sock *sk,
 869					struct hlist_head *list)
 870{
 871	hlist_add_head(&sk->sk_bind_node, list);
 872}
 873
 874static inline void __sk_del_bind2_node(struct sock *sk)
 875{
 876	__hlist_del(&sk->sk_bind2_node);
 877}
 878
 879static inline void sk_add_bind2_node(struct sock *sk, struct hlist_head *list)
 880{
 881	hlist_add_head(&sk->sk_bind2_node, list);
 882}
 883
 884#define sk_for_each(__sk, list) \
 885	hlist_for_each_entry(__sk, list, sk_node)
 886#define sk_for_each_rcu(__sk, list) \
 887	hlist_for_each_entry_rcu(__sk, list, sk_node)
 888#define sk_nulls_for_each(__sk, node, list) \
 889	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
 890#define sk_nulls_for_each_rcu(__sk, node, list) \
 891	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
 892#define sk_for_each_from(__sk) \
 893	hlist_for_each_entry_from(__sk, sk_node)
 894#define sk_nulls_for_each_from(__sk, node) \
 895	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
 896		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
 897#define sk_for_each_safe(__sk, tmp, list) \
 898	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
 899#define sk_for_each_bound(__sk, list) \
 900	hlist_for_each_entry(__sk, list, sk_bind_node)
 901#define sk_for_each_bound_bhash2(__sk, list) \
 902	hlist_for_each_entry(__sk, list, sk_bind2_node)
 903
 904/**
 905 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
 906 * @tpos:	the type * to use as a loop cursor.
 907 * @pos:	the &struct hlist_node to use as a loop cursor.
 908 * @head:	the head for your list.
 909 * @offset:	offset of hlist_node within the struct.
 910 *
 911 */
 912#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
 913	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
 914	     pos != NULL &&						       \
 915		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
 916	     pos = rcu_dereference(hlist_next_rcu(pos)))
 917
 918static inline struct user_namespace *sk_user_ns(const struct sock *sk)
 919{
 920	/* Careful only use this in a context where these parameters
 921	 * can not change and must all be valid, such as recvmsg from
 922	 * userspace.
 923	 */
 924	return sk->sk_socket->file->f_cred->user_ns;
 925}
 926
 927/* Sock flags */
 928enum sock_flags {
 929	SOCK_DEAD,
 930	SOCK_DONE,
 931	SOCK_URGINLINE,
 932	SOCK_KEEPOPEN,
 933	SOCK_LINGER,
 934	SOCK_DESTROY,
 935	SOCK_BROADCAST,
 936	SOCK_TIMESTAMP,
 937	SOCK_ZAPPED,
 938	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
 939	SOCK_DBG, /* %SO_DEBUG setting */
 940	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
 941	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
 942	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
 943	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
 944	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
 945	SOCK_FASYNC, /* fasync() active */
 946	SOCK_RXQ_OVFL,
 947	SOCK_ZEROCOPY, /* buffers from userspace */
 948	SOCK_WIFI_STATUS, /* push wifi status to userspace */
 949	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
 950		     * Will use last 4 bytes of packet sent from
 951		     * user-space instead.
 952		     */
 953	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
 954	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
 955	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
 956	SOCK_TXTIME,
 957	SOCK_XDP, /* XDP is attached */
 958	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
 959	SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
 960};
 961
 962#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
 963
 964static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
 965{
 966	nsk->sk_flags = osk->sk_flags;
 967}
 968
 969static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
 970{
 971	__set_bit(flag, &sk->sk_flags);
 972}
 973
 974static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
 975{
 976	__clear_bit(flag, &sk->sk_flags);
 977}
 978
 979static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
 980				     int valbool)
 981{
 982	if (valbool)
 983		sock_set_flag(sk, bit);
 984	else
 985		sock_reset_flag(sk, bit);
 986}
 987
 988static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
 989{
 990	return test_bit(flag, &sk->sk_flags);
 991}
 992
 993#ifdef CONFIG_NET
 994DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
 995static inline int sk_memalloc_socks(void)
 996{
 997	return static_branch_unlikely(&memalloc_socks_key);
 998}
 999
1000void __receive_sock(struct file *file);
1001#else
1002
1003static inline int sk_memalloc_socks(void)
1004{
1005	return 0;
1006}
1007
1008static inline void __receive_sock(struct file *file)
1009{ }
1010#endif
1011
1012static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
1013{
1014	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
1015}
1016
1017static inline void sk_acceptq_removed(struct sock *sk)
1018{
1019	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
1020}
1021
1022static inline void sk_acceptq_added(struct sock *sk)
1023{
1024	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
1025}
1026
1027/* Note: If you think the test should be:
1028 *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
1029 * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
1030 */
1031static inline bool sk_acceptq_is_full(const struct sock *sk)
1032{
1033	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
1034}
1035
1036/*
1037 * Compute minimal free write space needed to queue new packets.
1038 */
1039static inline int sk_stream_min_wspace(const struct sock *sk)
1040{
1041	return READ_ONCE(sk->sk_wmem_queued) >> 1;
1042}
1043
1044static inline int sk_stream_wspace(const struct sock *sk)
1045{
1046	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
1047}
1048
1049static inline void sk_wmem_queued_add(struct sock *sk, int val)
1050{
1051	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
1052}
1053
1054void sk_stream_write_space(struct sock *sk);
1055
1056/* OOB backlog add */
1057static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
1058{
1059	/* dont let skb dst not refcounted, we are going to leave rcu lock */
1060	skb_dst_force(skb);
1061
1062	if (!sk->sk_backlog.tail)
1063		WRITE_ONCE(sk->sk_backlog.head, skb);
1064	else
1065		sk->sk_backlog.tail->next = skb;
1066
1067	WRITE_ONCE(sk->sk_backlog.tail, skb);
1068	skb->next = NULL;
1069}
1070
1071/*
1072 * Take into account size of receive queue and backlog queue
1073 * Do not take into account this skb truesize,
1074 * to allow even a single big packet to come.
1075 */
1076static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
1077{
1078	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
1079
1080	return qsize > limit;
1081}
1082
1083/* The per-socket spinlock must be held here. */
1084static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1085					      unsigned int limit)
1086{
1087	if (sk_rcvqueues_full(sk, limit))
1088		return -ENOBUFS;
1089
1090	/*
1091	 * If the skb was allocated from pfmemalloc reserves, only
1092	 * allow SOCK_MEMALLOC sockets to use it as this socket is
1093	 * helping free memory
1094	 */
1095	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1096		return -ENOMEM;
1097
1098	__sk_add_backlog(sk, skb);
1099	sk->sk_backlog.len += skb->truesize;
1100	return 0;
1101}
1102
1103int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1104
1105INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
1106INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
1107
1108static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1109{
1110	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1111		return __sk_backlog_rcv(sk, skb);
1112
1113	return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
1114				  tcp_v6_do_rcv,
1115				  tcp_v4_do_rcv,
1116				  sk, skb);
1117}
1118
1119static inline void sk_incoming_cpu_update(struct sock *sk)
1120{
1121	int cpu = raw_smp_processor_id();
1122
1123	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1124		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1125}
1126
1127static inline void sock_rps_record_flow_hash(__u32 hash)
1128{
1129#ifdef CONFIG_RPS
1130	struct rps_sock_flow_table *sock_flow_table;
1131
1132	rcu_read_lock();
1133	sock_flow_table = rcu_dereference(rps_sock_flow_table);
1134	rps_record_sock_flow(sock_flow_table, hash);
1135	rcu_read_unlock();
1136#endif
1137}
1138
1139static inline void sock_rps_record_flow(const struct sock *sk)
1140{
1141#ifdef CONFIG_RPS
1142	if (static_branch_unlikely(&rfs_needed)) {
1143		/* Reading sk->sk_rxhash might incur an expensive cache line
1144		 * miss.
1145		 *
1146		 * TCP_ESTABLISHED does cover almost all states where RFS
1147		 * might be useful, and is cheaper [1] than testing :
1148		 *	IPv4: inet_sk(sk)->inet_daddr
1149		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1150		 * OR	an additional socket flag
1151		 * [1] : sk_state and sk_prot are in the same cache line.
1152		 */
1153		if (sk->sk_state == TCP_ESTABLISHED)
1154			sock_rps_record_flow_hash(sk->sk_rxhash);
1155	}
1156#endif
1157}
1158
1159static inline void sock_rps_save_rxhash(struct sock *sk,
1160					const struct sk_buff *skb)
1161{
1162#ifdef CONFIG_RPS
1163	if (unlikely(sk->sk_rxhash != skb->hash))
1164		sk->sk_rxhash = skb->hash;
1165#endif
1166}
1167
1168static inline void sock_rps_reset_rxhash(struct sock *sk)
1169{
1170#ifdef CONFIG_RPS
1171	sk->sk_rxhash = 0;
1172#endif
1173}
1174
1175#define sk_wait_event(__sk, __timeo, __condition, __wait)		\
1176	({	int __rc;						\
1177		release_sock(__sk);					\
1178		__rc = __condition;					\
1179		if (!__rc) {						\
1180			*(__timeo) = wait_woken(__wait,			\
1181						TASK_INTERRUPTIBLE,	\
1182						*(__timeo));		\
1183		}							\
1184		sched_annotate_sleep();					\
1185		lock_sock(__sk);					\
1186		__rc = __condition;					\
1187		__rc;							\
1188	})
1189
1190int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1191int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1192void sk_stream_wait_close(struct sock *sk, long timeo_p);
1193int sk_stream_error(struct sock *sk, int flags, int err);
1194void sk_stream_kill_queues(struct sock *sk);
1195void sk_set_memalloc(struct sock *sk);
1196void sk_clear_memalloc(struct sock *sk);
1197
1198void __sk_flush_backlog(struct sock *sk);
1199
1200static inline bool sk_flush_backlog(struct sock *sk)
1201{
1202	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1203		__sk_flush_backlog(sk);
1204		return true;
1205	}
1206	return false;
1207}
1208
1209int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1210
1211struct request_sock_ops;
1212struct timewait_sock_ops;
1213struct inet_hashinfo;
1214struct raw_hashinfo;
1215struct smc_hashinfo;
1216struct module;
1217struct sk_psock;
1218
1219/*
1220 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1221 * un-modified. Special care is taken when initializing object to zero.
1222 */
1223static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1224{
1225	if (offsetof(struct sock, sk_node.next) != 0)
1226		memset(sk, 0, offsetof(struct sock, sk_node.next));
1227	memset(&sk->sk_node.pprev, 0,
1228	       size - offsetof(struct sock, sk_node.pprev));
1229}
1230
1231/* Networking protocol blocks we attach to sockets.
1232 * socket layer -> transport layer interface
1233 */
1234struct proto {
1235	void			(*close)(struct sock *sk,
1236					long timeout);
1237	int			(*pre_connect)(struct sock *sk,
1238					struct sockaddr *uaddr,
1239					int addr_len);
1240	int			(*connect)(struct sock *sk,
1241					struct sockaddr *uaddr,
1242					int addr_len);
1243	int			(*disconnect)(struct sock *sk, int flags);
1244
1245	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
1246					  bool kern);
1247
1248	int			(*ioctl)(struct sock *sk, int cmd,
1249					 unsigned long arg);
1250	int			(*init)(struct sock *sk);
1251	void			(*destroy)(struct sock *sk);
1252	void			(*shutdown)(struct sock *sk, int how);
1253	int			(*setsockopt)(struct sock *sk, int level,
1254					int optname, sockptr_t optval,
1255					unsigned int optlen);
1256	int			(*getsockopt)(struct sock *sk, int level,
1257					int optname, char __user *optval,
1258					int __user *option);
1259	void			(*keepalive)(struct sock *sk, int valbool);
1260#ifdef CONFIG_COMPAT
1261	int			(*compat_ioctl)(struct sock *sk,
1262					unsigned int cmd, unsigned long arg);
1263#endif
1264	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
1265					   size_t len);
1266	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
1267					   size_t len, int flags, int *addr_len);
 
1268	int			(*sendpage)(struct sock *sk, struct page *page,
1269					int offset, size_t size, int flags);
1270	int			(*bind)(struct sock *sk,
1271					struct sockaddr *addr, int addr_len);
1272	int			(*bind_add)(struct sock *sk,
1273					struct sockaddr *addr, int addr_len);
1274
1275	int			(*backlog_rcv) (struct sock *sk,
1276						struct sk_buff *skb);
1277	bool			(*bpf_bypass_getsockopt)(int level,
1278							 int optname);
1279
1280	void		(*release_cb)(struct sock *sk);
1281
1282	/* Keeping track of sk's, looking them up, and port selection methods. */
1283	int			(*hash)(struct sock *sk);
1284	void			(*unhash)(struct sock *sk);
1285	void			(*rehash)(struct sock *sk);
1286	int			(*get_port)(struct sock *sk, unsigned short snum);
1287	void			(*put_port)(struct sock *sk);
1288#ifdef CONFIG_BPF_SYSCALL
1289	int			(*psock_update_sk_prot)(struct sock *sk,
1290							struct sk_psock *psock,
1291							bool restore);
1292#endif
1293
1294	/* Keeping track of sockets in use */
1295#ifdef CONFIG_PROC_FS
1296	unsigned int		inuse_idx;
1297#endif
1298
1299#if IS_ENABLED(CONFIG_MPTCP)
1300	int			(*forward_alloc_get)(const struct sock *sk);
1301#endif
1302
1303	bool			(*stream_memory_free)(const struct sock *sk, int wake);
1304	bool			(*sock_is_readable)(struct sock *sk);
1305	/* Memory pressure */
1306	void			(*enter_memory_pressure)(struct sock *sk);
1307	void			(*leave_memory_pressure)(struct sock *sk);
1308	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1309	int  __percpu		*per_cpu_fw_alloc;
1310	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1311
1312	/*
1313	 * Pressure flag: try to collapse.
1314	 * Technical note: it is used by multiple contexts non atomically.
1315	 * All the __sk_mem_schedule() is of this nature: accounting
1316	 * is strict, actions are advisory and have some latency.
1317	 */
1318	unsigned long		*memory_pressure;
1319	long			*sysctl_mem;
1320
1321	int			*sysctl_wmem;
1322	int			*sysctl_rmem;
1323	u32			sysctl_wmem_offset;
1324	u32			sysctl_rmem_offset;
1325
1326	int			max_header;
1327	bool			no_autobind;
1328
1329	struct kmem_cache	*slab;
1330	unsigned int		obj_size;
1331	slab_flags_t		slab_flags;
1332	unsigned int		useroffset;	/* Usercopy region offset */
1333	unsigned int		usersize;	/* Usercopy region size */
1334
1335	unsigned int __percpu	*orphan_count;
1336
1337	struct request_sock_ops	*rsk_prot;
1338	struct timewait_sock_ops *twsk_prot;
1339
1340	union {
1341		struct inet_hashinfo	*hashinfo;
1342		struct udp_table	*udp_table;
1343		struct raw_hashinfo	*raw_hash;
1344		struct smc_hashinfo	*smc_hash;
1345	} h;
1346
1347	struct module		*owner;
1348
1349	char			name[32];
1350
1351	struct list_head	node;
1352#ifdef SOCK_REFCNT_DEBUG
1353	atomic_t		socks;
1354#endif
1355	int			(*diag_destroy)(struct sock *sk, int err);
1356} __randomize_layout;
1357
1358int proto_register(struct proto *prot, int alloc_slab);
1359void proto_unregister(struct proto *prot);
1360int sock_load_diag_module(int family, int protocol);
1361
1362#ifdef SOCK_REFCNT_DEBUG
1363static inline void sk_refcnt_debug_inc(struct sock *sk)
1364{
1365	atomic_inc(&sk->sk_prot->socks);
1366}
1367
1368static inline void sk_refcnt_debug_dec(struct sock *sk)
1369{
1370	atomic_dec(&sk->sk_prot->socks);
1371	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1372	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1373}
1374
1375static inline void sk_refcnt_debug_release(const struct sock *sk)
1376{
1377	if (refcount_read(&sk->sk_refcnt) != 1)
1378		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1379		       sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1380}
1381#else /* SOCK_REFCNT_DEBUG */
1382#define sk_refcnt_debug_inc(sk) do { } while (0)
1383#define sk_refcnt_debug_dec(sk) do { } while (0)
1384#define sk_refcnt_debug_release(sk) do { } while (0)
1385#endif /* SOCK_REFCNT_DEBUG */
1386
1387INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
1388
1389static inline int sk_forward_alloc_get(const struct sock *sk)
1390{
1391#if IS_ENABLED(CONFIG_MPTCP)
1392	if (sk->sk_prot->forward_alloc_get)
1393		return sk->sk_prot->forward_alloc_get(sk);
1394#endif
1395	return sk->sk_forward_alloc;
1396}
1397
1398static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1399{
1400	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1401		return false;
1402
 
 
 
 
 
 
1403	return sk->sk_prot->stream_memory_free ?
1404		INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
1405				     tcp_stream_memory_free, sk, wake) : true;
1406}
1407
1408static inline bool sk_stream_memory_free(const struct sock *sk)
1409{
1410	return __sk_stream_memory_free(sk, 0);
1411}
1412
1413static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1414{
1415	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1416	       __sk_stream_memory_free(sk, wake);
1417}
1418
1419static inline bool sk_stream_is_writeable(const struct sock *sk)
1420{
1421	return __sk_stream_is_writeable(sk, 0);
1422}
1423
1424static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1425					    struct cgroup *ancestor)
1426{
1427#ifdef CONFIG_SOCK_CGROUP_DATA
1428	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1429				    ancestor);
1430#else
1431	return -ENOTSUPP;
1432#endif
1433}
1434
1435static inline bool sk_has_memory_pressure(const struct sock *sk)
1436{
1437	return sk->sk_prot->memory_pressure != NULL;
1438}
1439
1440static inline bool sk_under_memory_pressure(const struct sock *sk)
1441{
1442	if (!sk->sk_prot->memory_pressure)
1443		return false;
1444
1445	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1446	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
1447		return true;
1448
1449	return !!*sk->sk_prot->memory_pressure;
1450}
1451
1452static inline long
1453proto_memory_allocated(const struct proto *prot)
1454{
1455	return max(0L, atomic_long_read(prot->memory_allocated));
1456}
1457
1458static inline long
1459sk_memory_allocated(const struct sock *sk)
1460{
1461	return proto_memory_allocated(sk->sk_prot);
1462}
1463
1464/* 1 MB per cpu, in page units */
1465#define SK_MEMORY_PCPU_RESERVE (1 << (20 - PAGE_SHIFT))
1466
1467static inline void
1468sk_memory_allocated_add(struct sock *sk, int amt)
1469{
1470	int local_reserve;
1471
1472	preempt_disable();
1473	local_reserve = __this_cpu_add_return(*sk->sk_prot->per_cpu_fw_alloc, amt);
1474	if (local_reserve >= SK_MEMORY_PCPU_RESERVE) {
1475		__this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve);
1476		atomic_long_add(local_reserve, sk->sk_prot->memory_allocated);
1477	}
1478	preempt_enable();
1479}
1480
1481static inline void
1482sk_memory_allocated_sub(struct sock *sk, int amt)
1483{
1484	int local_reserve;
1485
1486	preempt_disable();
1487	local_reserve = __this_cpu_sub_return(*sk->sk_prot->per_cpu_fw_alloc, amt);
1488	if (local_reserve <= -SK_MEMORY_PCPU_RESERVE) {
1489		__this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve);
1490		atomic_long_add(local_reserve, sk->sk_prot->memory_allocated);
1491	}
1492	preempt_enable();
1493}
1494
1495#define SK_ALLOC_PERCPU_COUNTER_BATCH 16
1496
1497static inline void sk_sockets_allocated_dec(struct sock *sk)
1498{
1499	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
1500				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1501}
1502
1503static inline void sk_sockets_allocated_inc(struct sock *sk)
1504{
1505	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
1506				 SK_ALLOC_PERCPU_COUNTER_BATCH);
1507}
1508
1509static inline u64
1510sk_sockets_allocated_read_positive(struct sock *sk)
1511{
1512	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1513}
1514
1515static inline int
1516proto_sockets_allocated_sum_positive(struct proto *prot)
1517{
1518	return percpu_counter_sum_positive(prot->sockets_allocated);
1519}
1520
 
 
 
 
 
 
1521static inline bool
1522proto_memory_pressure(struct proto *prot)
1523{
1524	if (!prot->memory_pressure)
1525		return false;
1526	return !!*prot->memory_pressure;
1527}
1528
1529
1530#ifdef CONFIG_PROC_FS
1531#define PROTO_INUSE_NR	64	/* should be enough for the first time */
1532struct prot_inuse {
1533	int all;
1534	int val[PROTO_INUSE_NR];
1535};
1536
1537static inline void sock_prot_inuse_add(const struct net *net,
1538				       const struct proto *prot, int val)
1539{
1540	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
1541}
1542
1543static inline void sock_inuse_add(const struct net *net, int val)
1544{
1545	this_cpu_add(net->core.prot_inuse->all, val);
1546}
1547
1548int sock_prot_inuse_get(struct net *net, struct proto *proto);
1549int sock_inuse_get(struct net *net);
1550#else
1551static inline void sock_prot_inuse_add(const struct net *net,
1552				       const struct proto *prot, int val)
1553{
1554}
1555
1556static inline void sock_inuse_add(const struct net *net, int val)
1557{
1558}
1559#endif
1560
1561
1562/* With per-bucket locks this operation is not-atomic, so that
1563 * this version is not worse.
1564 */
1565static inline int __sk_prot_rehash(struct sock *sk)
1566{
1567	sk->sk_prot->unhash(sk);
1568	return sk->sk_prot->hash(sk);
1569}
1570
1571/* About 10 seconds */
1572#define SOCK_DESTROY_TIME (10*HZ)
1573
1574/* Sockets 0-1023 can't be bound to unless you are superuser */
1575#define PROT_SOCK	1024
1576
1577#define SHUTDOWN_MASK	3
1578#define RCV_SHUTDOWN	1
1579#define SEND_SHUTDOWN	2
1580
 
 
1581#define SOCK_BINDADDR_LOCK	4
1582#define SOCK_BINDPORT_LOCK	8
1583
1584struct socket_alloc {
1585	struct socket socket;
1586	struct inode vfs_inode;
1587};
1588
1589static inline struct socket *SOCKET_I(struct inode *inode)
1590{
1591	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1592}
1593
1594static inline struct inode *SOCK_INODE(struct socket *socket)
1595{
1596	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1597}
1598
1599/*
1600 * Functions for memory accounting
1601 */
1602int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1603int __sk_mem_schedule(struct sock *sk, int size, int kind);
1604void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1605void __sk_mem_reclaim(struct sock *sk, int amount);
1606
 
 
 
 
 
1607#define SK_MEM_SEND	0
1608#define SK_MEM_RECV	1
1609
1610/* sysctl_mem values are in pages */
1611static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1612{
1613	return READ_ONCE(sk->sk_prot->sysctl_mem[index]);
 
 
 
 
 
 
 
1614}
1615
1616static inline int sk_mem_pages(int amt)
1617{
1618	return (amt + PAGE_SIZE - 1) >> PAGE_SHIFT;
1619}
1620
1621static inline bool sk_has_account(struct sock *sk)
1622{
1623	/* return true if protocol supports memory accounting */
1624	return !!sk->sk_prot->memory_allocated;
1625}
1626
1627static inline bool sk_wmem_schedule(struct sock *sk, int size)
1628{
1629	int delta;
1630
1631	if (!sk_has_account(sk))
1632		return true;
1633	delta = size - sk->sk_forward_alloc;
1634	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
1635}
1636
1637static inline bool
1638sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1639{
1640	int delta;
1641
1642	if (!sk_has_account(sk))
1643		return true;
1644	delta = size - sk->sk_forward_alloc;
1645	return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
1646		skb_pfmemalloc(skb);
1647}
1648
1649static inline int sk_unused_reserved_mem(const struct sock *sk)
1650{
1651	int unused_mem;
1652
1653	if (likely(!sk->sk_reserved_mem))
1654		return 0;
1655
1656	unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
1657			atomic_read(&sk->sk_rmem_alloc);
1658
1659	return unused_mem > 0 ? unused_mem : 0;
1660}
1661
1662static inline void sk_mem_reclaim(struct sock *sk)
1663{
1664	int reclaimable;
1665
1666	if (!sk_has_account(sk))
1667		return;
1668
1669	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
1670
1671	if (reclaimable >= (int)PAGE_SIZE)
1672		__sk_mem_reclaim(sk, reclaimable);
1673}
1674
1675static inline void sk_mem_reclaim_final(struct sock *sk)
1676{
1677	sk->sk_reserved_mem = 0;
1678	sk_mem_reclaim(sk);
 
 
1679}
1680
1681static inline void sk_mem_charge(struct sock *sk, int size)
1682{
1683	if (!sk_has_account(sk))
1684		return;
1685	sk->sk_forward_alloc -= size;
1686}
1687
1688static inline void sk_mem_uncharge(struct sock *sk, int size)
1689{
1690	if (!sk_has_account(sk))
1691		return;
1692	sk->sk_forward_alloc += size;
1693	sk_mem_reclaim(sk);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1694}
1695
1696/*
1697 * Macro so as to not evaluate some arguments when
1698 * lockdep is not enabled.
1699 *
1700 * Mark both the sk_lock and the sk_lock.slock as a
1701 * per-address-family lock class.
1702 */
1703#define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1704do {									\
1705	sk->sk_lock.owned = 0;						\
1706	init_waitqueue_head(&sk->sk_lock.wq);				\
1707	spin_lock_init(&(sk)->sk_lock.slock);				\
1708	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1709			sizeof((sk)->sk_lock));				\
1710	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1711				(skey), (sname));				\
1712	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1713} while (0)
1714
1715static inline bool lockdep_sock_is_held(const struct sock *sk)
1716{
1717	return lockdep_is_held(&sk->sk_lock) ||
1718	       lockdep_is_held(&sk->sk_lock.slock);
1719}
1720
1721void lock_sock_nested(struct sock *sk, int subclass);
1722
1723static inline void lock_sock(struct sock *sk)
1724{
1725	lock_sock_nested(sk, 0);
1726}
1727
1728void __lock_sock(struct sock *sk);
1729void __release_sock(struct sock *sk);
1730void release_sock(struct sock *sk);
1731
1732/* BH context may only use the following locking interface. */
1733#define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1734#define bh_lock_sock_nested(__sk) \
1735				spin_lock_nested(&((__sk)->sk_lock.slock), \
1736				SINGLE_DEPTH_NESTING)
1737#define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1738
1739bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
1740
1741/**
1742 * lock_sock_fast - fast version of lock_sock
1743 * @sk: socket
1744 *
1745 * This version should be used for very small section, where process wont block
1746 * return false if fast path is taken:
1747 *
1748 *   sk_lock.slock locked, owned = 0, BH disabled
1749 *
1750 * return true if slow path is taken:
1751 *
1752 *   sk_lock.slock unlocked, owned = 1, BH enabled
1753 */
1754static inline bool lock_sock_fast(struct sock *sk)
1755{
1756	/* The sk_lock has mutex_lock() semantics here. */
1757	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
1758
1759	return __lock_sock_fast(sk);
1760}
1761
1762/* fast socket lock variant for caller already holding a [different] socket lock */
1763static inline bool lock_sock_fast_nested(struct sock *sk)
1764{
1765	mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
1766
1767	return __lock_sock_fast(sk);
1768}
1769
1770/**
1771 * unlock_sock_fast - complement of lock_sock_fast
1772 * @sk: socket
1773 * @slow: slow mode
1774 *
1775 * fast unlock socket for user context.
1776 * If slow mode is on, we call regular release_sock()
1777 */
1778static inline void unlock_sock_fast(struct sock *sk, bool slow)
1779	__releases(&sk->sk_lock.slock)
1780{
1781	if (slow) {
1782		release_sock(sk);
1783		__release(&sk->sk_lock.slock);
1784	} else {
1785		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1786		spin_unlock_bh(&sk->sk_lock.slock);
1787	}
1788}
1789
1790void sockopt_lock_sock(struct sock *sk);
1791void sockopt_release_sock(struct sock *sk);
1792bool sockopt_ns_capable(struct user_namespace *ns, int cap);
1793bool sockopt_capable(int cap);
1794
1795/* Used by processes to "lock" a socket state, so that
1796 * interrupts and bottom half handlers won't change it
1797 * from under us. It essentially blocks any incoming
1798 * packets, so that we won't get any new data or any
1799 * packets that change the state of the socket.
1800 *
1801 * While locked, BH processing will add new packets to
1802 * the backlog queue.  This queue is processed by the
1803 * owner of the socket lock right before it is released.
1804 *
1805 * Since ~2.3.5 it is also exclusive sleep lock serializing
1806 * accesses from user process context.
1807 */
1808
1809static inline void sock_owned_by_me(const struct sock *sk)
1810{
1811#ifdef CONFIG_LOCKDEP
1812	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1813#endif
1814}
1815
1816static inline bool sock_owned_by_user(const struct sock *sk)
1817{
1818	sock_owned_by_me(sk);
1819	return sk->sk_lock.owned;
1820}
1821
1822static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1823{
1824	return sk->sk_lock.owned;
1825}
1826
1827static inline void sock_release_ownership(struct sock *sk)
1828{
1829	if (sock_owned_by_user_nocheck(sk)) {
1830		sk->sk_lock.owned = 0;
1831
1832		/* The sk_lock has mutex_unlock() semantics: */
1833		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1834	}
1835}
1836
1837/* no reclassification while locks are held */
1838static inline bool sock_allow_reclassification(const struct sock *csk)
1839{
1840	struct sock *sk = (struct sock *)csk;
1841
1842	return !sock_owned_by_user_nocheck(sk) &&
1843		!spin_is_locked(&sk->sk_lock.slock);
1844}
1845
1846struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1847		      struct proto *prot, int kern);
1848void sk_free(struct sock *sk);
1849void sk_destruct(struct sock *sk);
1850struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1851void sk_free_unlock_clone(struct sock *sk);
1852
1853struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1854			     gfp_t priority);
1855void __sock_wfree(struct sk_buff *skb);
1856void sock_wfree(struct sk_buff *skb);
1857struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1858			     gfp_t priority);
1859void skb_orphan_partial(struct sk_buff *skb);
1860void sock_rfree(struct sk_buff *skb);
1861void sock_efree(struct sk_buff *skb);
1862#ifdef CONFIG_INET
1863void sock_edemux(struct sk_buff *skb);
1864void sock_pfree(struct sk_buff *skb);
1865#else
1866#define sock_edemux sock_efree
1867#endif
1868
1869int sk_setsockopt(struct sock *sk, int level, int optname,
1870		  sockptr_t optval, unsigned int optlen);
1871int sock_setsockopt(struct socket *sock, int level, int op,
1872		    sockptr_t optval, unsigned int optlen);
1873
1874int sk_getsockopt(struct sock *sk, int level, int optname,
1875		  sockptr_t optval, sockptr_t optlen);
1876int sock_getsockopt(struct socket *sock, int level, int op,
1877		    char __user *optval, int __user *optlen);
1878int sock_gettstamp(struct socket *sock, void __user *userstamp,
1879		   bool timeval, bool time32);
 
 
1880struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1881				     unsigned long data_len, int noblock,
1882				     int *errcode, int max_page_order);
1883
1884static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1885						  unsigned long size,
1886						  int noblock, int *errcode)
1887{
1888	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1889}
1890
1891void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1892void sock_kfree_s(struct sock *sk, void *mem, int size);
1893void sock_kzfree_s(struct sock *sk, void *mem, int size);
1894void sk_send_sigurg(struct sock *sk);
1895
1896static inline void sock_replace_proto(struct sock *sk, struct proto *proto)
1897{
1898	if (sk->sk_socket)
1899		clear_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
1900	WRITE_ONCE(sk->sk_prot, proto);
1901}
1902
1903struct sockcm_cookie {
1904	u64 transmit_time;
1905	u32 mark;
1906	u32 tsflags;
1907};
1908
1909static inline void sockcm_init(struct sockcm_cookie *sockc,
1910			       const struct sock *sk)
1911{
1912	*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1913}
1914
1915int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
1916		     struct sockcm_cookie *sockc);
1917int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1918		   struct sockcm_cookie *sockc);
1919
1920/*
1921 * Functions to fill in entries in struct proto_ops when a protocol
1922 * does not implement a particular function.
1923 */
1924int sock_no_bind(struct socket *, struct sockaddr *, int);
1925int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1926int sock_no_socketpair(struct socket *, struct socket *);
1927int sock_no_accept(struct socket *, struct socket *, int, bool);
1928int sock_no_getname(struct socket *, struct sockaddr *, int);
1929int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1930int sock_no_listen(struct socket *, int);
1931int sock_no_shutdown(struct socket *, int);
1932int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1933int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1934int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1935int sock_no_mmap(struct file *file, struct socket *sock,
1936		 struct vm_area_struct *vma);
1937ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1938			 size_t size, int flags);
1939ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1940				int offset, size_t size, int flags);
1941
1942/*
1943 * Functions to fill in entries in struct proto_ops when a protocol
1944 * uses the inet style.
1945 */
1946int sock_common_getsockopt(struct socket *sock, int level, int optname,
1947				  char __user *optval, int __user *optlen);
1948int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1949			int flags);
1950int sock_common_setsockopt(struct socket *sock, int level, int optname,
1951			   sockptr_t optval, unsigned int optlen);
1952
1953void sk_common_release(struct sock *sk);
1954
1955/*
1956 *	Default socket callbacks and setup code
1957 */
1958
1959/* Initialise core socket variables */
1960void sock_init_data(struct socket *sock, struct sock *sk);
1961
1962/*
1963 * Socket reference counting postulates.
1964 *
1965 * * Each user of socket SHOULD hold a reference count.
1966 * * Each access point to socket (an hash table bucket, reference from a list,
1967 *   running timer, skb in flight MUST hold a reference count.
1968 * * When reference count hits 0, it means it will never increase back.
1969 * * When reference count hits 0, it means that no references from
1970 *   outside exist to this socket and current process on current CPU
1971 *   is last user and may/should destroy this socket.
1972 * * sk_free is called from any context: process, BH, IRQ. When
1973 *   it is called, socket has no references from outside -> sk_free
1974 *   may release descendant resources allocated by the socket, but
1975 *   to the time when it is called, socket is NOT referenced by any
1976 *   hash tables, lists etc.
1977 * * Packets, delivered from outside (from network or from another process)
1978 *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1979 *   when they sit in queue. Otherwise, packets will leak to hole, when
1980 *   socket is looked up by one cpu and unhasing is made by another CPU.
1981 *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1982 *   (leak to backlog). Packet socket does all the processing inside
1983 *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1984 *   use separate SMP lock, so that they are prone too.
1985 */
1986
1987/* Ungrab socket and destroy it, if it was the last reference. */
1988static inline void sock_put(struct sock *sk)
1989{
1990	if (refcount_dec_and_test(&sk->sk_refcnt))
1991		sk_free(sk);
1992}
1993/* Generic version of sock_put(), dealing with all sockets
1994 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1995 */
1996void sock_gen_put(struct sock *sk);
1997
1998int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1999		     unsigned int trim_cap, bool refcounted);
2000static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
2001				 const int nested)
2002{
2003	return __sk_receive_skb(sk, skb, nested, 1, true);
2004}
2005
2006static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
2007{
2008	/* sk_tx_queue_mapping accept only upto a 16-bit value */
2009	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
2010		return;
2011	sk->sk_tx_queue_mapping = tx_queue;
2012}
2013
2014#define NO_QUEUE_MAPPING	USHRT_MAX
2015
2016static inline void sk_tx_queue_clear(struct sock *sk)
2017{
2018	sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
2019}
2020
2021static inline int sk_tx_queue_get(const struct sock *sk)
2022{
2023	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
2024		return sk->sk_tx_queue_mapping;
2025
2026	return -1;
2027}
2028
2029static inline void __sk_rx_queue_set(struct sock *sk,
2030				     const struct sk_buff *skb,
2031				     bool force_set)
2032{
2033#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2034	if (skb_rx_queue_recorded(skb)) {
2035		u16 rx_queue = skb_get_rx_queue(skb);
2036
2037		if (force_set ||
2038		    unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
2039			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
 
2040	}
2041#endif
2042}
2043
2044static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
2045{
2046	__sk_rx_queue_set(sk, skb, true);
2047}
2048
2049static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
2050{
2051	__sk_rx_queue_set(sk, skb, false);
2052}
2053
2054static inline void sk_rx_queue_clear(struct sock *sk)
2055{
2056#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2057	WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
2058#endif
2059}
2060
2061static inline int sk_rx_queue_get(const struct sock *sk)
2062{
2063#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
2064	if (sk) {
2065		int res = READ_ONCE(sk->sk_rx_queue_mapping);
2066
2067		if (res != NO_QUEUE_MAPPING)
2068			return res;
2069	}
2070#endif
2071
2072	return -1;
2073}
2074
2075static inline void sk_set_socket(struct sock *sk, struct socket *sock)
2076{
2077	sk->sk_socket = sock;
2078}
2079
2080static inline wait_queue_head_t *sk_sleep(struct sock *sk)
2081{
2082	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
2083	return &rcu_dereference_raw(sk->sk_wq)->wait;
2084}
2085/* Detach socket from process context.
2086 * Announce socket dead, detach it from wait queue and inode.
2087 * Note that parent inode held reference count on this struct sock,
2088 * we do not release it in this function, because protocol
2089 * probably wants some additional cleanups or even continuing
2090 * to work with this socket (TCP).
2091 */
2092static inline void sock_orphan(struct sock *sk)
2093{
2094	write_lock_bh(&sk->sk_callback_lock);
2095	sock_set_flag(sk, SOCK_DEAD);
2096	sk_set_socket(sk, NULL);
2097	sk->sk_wq  = NULL;
2098	write_unlock_bh(&sk->sk_callback_lock);
2099}
2100
2101static inline void sock_graft(struct sock *sk, struct socket *parent)
2102{
2103	WARN_ON(parent->sk);
2104	write_lock_bh(&sk->sk_callback_lock);
2105	rcu_assign_pointer(sk->sk_wq, &parent->wq);
2106	parent->sk = sk;
2107	sk_set_socket(sk, parent);
2108	sk->sk_uid = SOCK_INODE(parent)->i_uid;
2109	security_sock_graft(sk, parent);
2110	write_unlock_bh(&sk->sk_callback_lock);
2111}
2112
2113kuid_t sock_i_uid(struct sock *sk);
2114unsigned long sock_i_ino(struct sock *sk);
2115
2116static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
2117{
2118	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
2119}
2120
2121static inline u32 net_tx_rndhash(void)
2122{
2123	u32 v = get_random_u32();
2124
2125	return v ?: 1;
2126}
2127
2128static inline void sk_set_txhash(struct sock *sk)
2129{
2130	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
2131	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
2132}
2133
2134static inline bool sk_rethink_txhash(struct sock *sk)
2135{
2136	if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
2137		sk_set_txhash(sk);
2138		return true;
2139	}
2140	return false;
2141}
2142
2143static inline struct dst_entry *
2144__sk_dst_get(struct sock *sk)
2145{
2146	return rcu_dereference_check(sk->sk_dst_cache,
2147				     lockdep_sock_is_held(sk));
2148}
2149
2150static inline struct dst_entry *
2151sk_dst_get(struct sock *sk)
2152{
2153	struct dst_entry *dst;
2154
2155	rcu_read_lock();
2156	dst = rcu_dereference(sk->sk_dst_cache);
2157	if (dst && !atomic_inc_not_zero(&dst->__refcnt))
2158		dst = NULL;
2159	rcu_read_unlock();
2160	return dst;
2161}
2162
2163static inline void __dst_negative_advice(struct sock *sk)
2164{
2165	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
2166
2167	if (dst && dst->ops->negative_advice) {
2168		ndst = dst->ops->negative_advice(dst);
2169
2170		if (ndst != dst) {
2171			rcu_assign_pointer(sk->sk_dst_cache, ndst);
2172			sk_tx_queue_clear(sk);
2173			sk->sk_dst_pending_confirm = 0;
2174		}
2175	}
2176}
2177
2178static inline void dst_negative_advice(struct sock *sk)
2179{
2180	sk_rethink_txhash(sk);
2181	__dst_negative_advice(sk);
2182}
2183
2184static inline void
2185__sk_dst_set(struct sock *sk, struct dst_entry *dst)
2186{
2187	struct dst_entry *old_dst;
2188
2189	sk_tx_queue_clear(sk);
2190	sk->sk_dst_pending_confirm = 0;
2191	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2192					    lockdep_sock_is_held(sk));
2193	rcu_assign_pointer(sk->sk_dst_cache, dst);
2194	dst_release(old_dst);
2195}
2196
2197static inline void
2198sk_dst_set(struct sock *sk, struct dst_entry *dst)
2199{
2200	struct dst_entry *old_dst;
2201
2202	sk_tx_queue_clear(sk);
2203	sk->sk_dst_pending_confirm = 0;
2204	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
2205	dst_release(old_dst);
2206}
2207
2208static inline void
2209__sk_dst_reset(struct sock *sk)
2210{
2211	__sk_dst_set(sk, NULL);
2212}
2213
2214static inline void
2215sk_dst_reset(struct sock *sk)
2216{
2217	sk_dst_set(sk, NULL);
2218}
2219
2220struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2221
2222struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2223
2224static inline void sk_dst_confirm(struct sock *sk)
2225{
2226	if (!READ_ONCE(sk->sk_dst_pending_confirm))
2227		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2228}
2229
2230static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2231{
2232	if (skb_get_dst_pending_confirm(skb)) {
2233		struct sock *sk = skb->sk;
 
2234
 
 
 
2235		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2236			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2237		neigh_confirm(n);
2238	}
2239}
2240
2241bool sk_mc_loop(struct sock *sk);
2242
2243static inline bool sk_can_gso(const struct sock *sk)
2244{
2245	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2246}
2247
2248void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2249
2250static inline void sk_gso_disable(struct sock *sk)
2251{
2252	sk->sk_gso_disabled = 1;
2253	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
2254}
2255
2256static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2257					   struct iov_iter *from, char *to,
2258					   int copy, int offset)
2259{
2260	if (skb->ip_summed == CHECKSUM_NONE) {
2261		__wsum csum = 0;
2262		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2263			return -EFAULT;
2264		skb->csum = csum_block_add(skb->csum, csum, offset);
2265	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2266		if (!copy_from_iter_full_nocache(to, copy, from))
2267			return -EFAULT;
2268	} else if (!copy_from_iter_full(to, copy, from))
2269		return -EFAULT;
2270
2271	return 0;
2272}
2273
2274static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2275				       struct iov_iter *from, int copy)
2276{
2277	int err, offset = skb->len;
2278
2279	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2280				       copy, offset);
2281	if (err)
2282		__skb_trim(skb, offset);
2283
2284	return err;
2285}
2286
2287static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2288					   struct sk_buff *skb,
2289					   struct page *page,
2290					   int off, int copy)
2291{
2292	int err;
2293
2294	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2295				       copy, skb->len);
2296	if (err)
2297		return err;
2298
2299	skb_len_add(skb, copy);
 
 
2300	sk_wmem_queued_add(sk, copy);
2301	sk_mem_charge(sk, copy);
2302	return 0;
2303}
2304
2305/**
2306 * sk_wmem_alloc_get - returns write allocations
2307 * @sk: socket
2308 *
2309 * Return: sk_wmem_alloc minus initial offset of one
2310 */
2311static inline int sk_wmem_alloc_get(const struct sock *sk)
2312{
2313	return refcount_read(&sk->sk_wmem_alloc) - 1;
2314}
2315
2316/**
2317 * sk_rmem_alloc_get - returns read allocations
2318 * @sk: socket
2319 *
2320 * Return: sk_rmem_alloc
2321 */
2322static inline int sk_rmem_alloc_get(const struct sock *sk)
2323{
2324	return atomic_read(&sk->sk_rmem_alloc);
2325}
2326
2327/**
2328 * sk_has_allocations - check if allocations are outstanding
2329 * @sk: socket
2330 *
2331 * Return: true if socket has write or read allocations
2332 */
2333static inline bool sk_has_allocations(const struct sock *sk)
2334{
2335	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2336}
2337
2338/**
2339 * skwq_has_sleeper - check if there are any waiting processes
2340 * @wq: struct socket_wq
2341 *
2342 * Return: true if socket_wq has waiting processes
2343 *
2344 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2345 * barrier call. They were added due to the race found within the tcp code.
2346 *
2347 * Consider following tcp code paths::
2348 *
2349 *   CPU1                CPU2
2350 *   sys_select          receive packet
2351 *   ...                 ...
2352 *   __add_wait_queue    update tp->rcv_nxt
2353 *   ...                 ...
2354 *   tp->rcv_nxt check   sock_def_readable
2355 *   ...                 {
2356 *   schedule               rcu_read_lock();
2357 *                          wq = rcu_dereference(sk->sk_wq);
2358 *                          if (wq && waitqueue_active(&wq->wait))
2359 *                              wake_up_interruptible(&wq->wait)
2360 *                          ...
2361 *                       }
2362 *
2363 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2364 * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
2365 * could then endup calling schedule and sleep forever if there are no more
2366 * data on the socket.
2367 *
2368 */
2369static inline bool skwq_has_sleeper(struct socket_wq *wq)
2370{
2371	return wq && wq_has_sleeper(&wq->wait);
2372}
2373
2374/**
2375 * sock_poll_wait - place memory barrier behind the poll_wait call.
2376 * @filp:           file
2377 * @sock:           socket to wait on
2378 * @p:              poll_table
2379 *
2380 * See the comments in the wq_has_sleeper function.
2381 */
2382static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2383				  poll_table *p)
2384{
2385	if (!poll_does_not_wait(p)) {
2386		poll_wait(filp, &sock->wq.wait, p);
2387		/* We need to be sure we are in sync with the
2388		 * socket flags modification.
2389		 *
2390		 * This memory barrier is paired in the wq_has_sleeper.
2391		 */
2392		smp_mb();
2393	}
2394}
2395
2396static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2397{
2398	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
2399	u32 txhash = READ_ONCE(sk->sk_txhash);
2400
2401	if (txhash) {
2402		skb->l4_hash = 1;
2403		skb->hash = txhash;
2404	}
2405}
2406
2407void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2408
2409/*
2410 *	Queue a received datagram if it will fit. Stream and sequenced
2411 *	protocols can't normally use this as they need to fit buffers in
2412 *	and play with them.
2413 *
2414 *	Inlined as it's very short and called for pretty much every
2415 *	packet ever received.
2416 */
2417static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2418{
2419	skb_orphan(skb);
2420	skb->sk = sk;
2421	skb->destructor = sock_rfree;
2422	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2423	sk_mem_charge(sk, skb->truesize);
2424}
2425
2426static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2427{
2428	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2429		skb_orphan(skb);
2430		skb->destructor = sock_efree;
2431		skb->sk = sk;
2432		return true;
2433	}
2434	return false;
2435}
2436
2437static inline struct sk_buff *skb_clone_and_charge_r(struct sk_buff *skb, struct sock *sk)
2438{
2439	skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC));
2440	if (skb) {
2441		if (sk_rmem_schedule(sk, skb, skb->truesize)) {
2442			skb_set_owner_r(skb, sk);
2443			return skb;
2444		}
2445		__kfree_skb(skb);
2446	}
2447	return NULL;
2448}
2449
2450static inline void skb_prepare_for_gro(struct sk_buff *skb)
2451{
2452	if (skb->destructor != sock_wfree) {
2453		skb_orphan(skb);
2454		return;
2455	}
2456	skb->slow_gro = 1;
2457}
2458
2459void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2460		    unsigned long expires);
2461
2462void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2463
2464void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2465
2466int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2467			struct sk_buff *skb, unsigned int flags,
2468			void (*destructor)(struct sock *sk,
2469					   struct sk_buff *skb));
2470int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2471
2472int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
2473			      enum skb_drop_reason *reason);
2474
2475static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
2476{
2477	return sock_queue_rcv_skb_reason(sk, skb, NULL);
2478}
2479
2480int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2481struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2482
2483/*
2484 *	Recover an error report and clear atomically
2485 */
2486
2487static inline int sock_error(struct sock *sk)
2488{
2489	int err;
2490
2491	/* Avoid an atomic operation for the common case.
2492	 * This is racy since another cpu/thread can change sk_err under us.
2493	 */
2494	if (likely(data_race(!sk->sk_err)))
2495		return 0;
2496
2497	err = xchg(&sk->sk_err, 0);
2498	return -err;
2499}
2500
2501void sk_error_report(struct sock *sk);
2502
2503static inline unsigned long sock_wspace(struct sock *sk)
2504{
2505	int amt = 0;
2506
2507	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2508		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2509		if (amt < 0)
2510			amt = 0;
2511	}
2512	return amt;
2513}
2514
2515/* Note:
2516 *  We use sk->sk_wq_raw, from contexts knowing this
2517 *  pointer is not NULL and cannot disappear/change.
2518 */
2519static inline void sk_set_bit(int nr, struct sock *sk)
2520{
2521	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2522	    !sock_flag(sk, SOCK_FASYNC))
2523		return;
2524
2525	set_bit(nr, &sk->sk_wq_raw->flags);
2526}
2527
2528static inline void sk_clear_bit(int nr, struct sock *sk)
2529{
2530	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2531	    !sock_flag(sk, SOCK_FASYNC))
2532		return;
2533
2534	clear_bit(nr, &sk->sk_wq_raw->flags);
2535}
2536
2537static inline void sk_wake_async(const struct sock *sk, int how, int band)
2538{
2539	if (sock_flag(sk, SOCK_FASYNC)) {
2540		rcu_read_lock();
2541		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2542		rcu_read_unlock();
2543	}
2544}
2545
2546/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2547 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2548 * Note: for send buffers, TCP works better if we can build two skbs at
2549 * minimum.
2550 */
2551#define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2552
2553#define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2554#define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2555
2556static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2557{
2558	u32 val;
2559
2560	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2561		return;
2562
2563	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2564	val = max_t(u32, val, sk_unused_reserved_mem(sk));
2565
2566	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2567}
2568
 
 
 
2569/**
2570 * sk_page_frag - return an appropriate page_frag
2571 * @sk: socket
2572 *
2573 * Use the per task page_frag instead of the per socket one for
2574 * optimization when we know that we're in process context and own
2575 * everything that's associated with %current.
2576 *
2577 * Both direct reclaim and page faults can nest inside other
2578 * socket operations and end up recursing into sk_page_frag()
2579 * while it's already in use: explicitly avoid task page_frag
2580 * when users disable sk_use_task_frag.
2581 *
2582 * Return: a per task page_frag if context allows that,
2583 * otherwise a per socket one.
2584 */
2585static inline struct page_frag *sk_page_frag(struct sock *sk)
2586{
2587	if (sk->sk_use_task_frag)
2588		return &current->task_frag;
2589
2590	return &sk->sk_frag;
2591}
2592
2593bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2594
2595/*
2596 *	Default write policy as shown to user space via poll/select/SIGIO
2597 */
2598static inline bool sock_writeable(const struct sock *sk)
2599{
2600	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2601}
2602
2603static inline gfp_t gfp_any(void)
2604{
2605	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2606}
2607
2608static inline gfp_t gfp_memcg_charge(void)
2609{
2610	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2611}
2612
2613static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2614{
2615	return noblock ? 0 : sk->sk_rcvtimeo;
2616}
2617
2618static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2619{
2620	return noblock ? 0 : sk->sk_sndtimeo;
2621}
2622
2623static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2624{
2625	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2626
2627	return v ?: 1;
2628}
2629
2630/* Alas, with timeout socket operations are not restartable.
2631 * Compare this to poll().
2632 */
2633static inline int sock_intr_errno(long timeo)
2634{
2635	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2636}
2637
2638struct sock_skb_cb {
2639	u32 dropcount;
2640};
2641
2642/* Store sock_skb_cb at the end of skb->cb[] so protocol families
2643 * using skb->cb[] would keep using it directly and utilize its
2644 * alignement guarantee.
2645 */
2646#define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2647			    sizeof(struct sock_skb_cb)))
2648
2649#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2650			    SOCK_SKB_CB_OFFSET))
2651
2652#define sock_skb_cb_check_size(size) \
2653	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2654
2655static inline void
2656sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2657{
2658	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2659						atomic_read(&sk->sk_drops) : 0;
2660}
2661
2662static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2663{
2664	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2665
2666	atomic_add(segs, &sk->sk_drops);
2667}
2668
2669static inline ktime_t sock_read_timestamp(struct sock *sk)
2670{
2671#if BITS_PER_LONG==32
2672	unsigned int seq;
2673	ktime_t kt;
2674
2675	do {
2676		seq = read_seqbegin(&sk->sk_stamp_seq);
2677		kt = sk->sk_stamp;
2678	} while (read_seqretry(&sk->sk_stamp_seq, seq));
2679
2680	return kt;
2681#else
2682	return READ_ONCE(sk->sk_stamp);
2683#endif
2684}
2685
2686static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2687{
2688#if BITS_PER_LONG==32
2689	write_seqlock(&sk->sk_stamp_seq);
2690	sk->sk_stamp = kt;
2691	write_sequnlock(&sk->sk_stamp_seq);
2692#else
2693	WRITE_ONCE(sk->sk_stamp, kt);
2694#endif
2695}
2696
2697void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2698			   struct sk_buff *skb);
2699void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2700			     struct sk_buff *skb);
2701
2702static inline void
2703sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2704{
2705	ktime_t kt = skb->tstamp;
2706	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2707
2708	/*
2709	 * generate control messages if
2710	 * - receive time stamping in software requested
2711	 * - software time stamp available and wanted
2712	 * - hardware time stamps available and wanted
2713	 */
2714	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2715	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2716	    (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2717	    (hwtstamps->hwtstamp &&
2718	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2719		__sock_recv_timestamp(msg, sk, skb);
2720	else
2721		sock_write_timestamp(sk, kt);
2722
2723	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2724		__sock_recv_wifi_status(msg, sk, skb);
2725}
2726
2727void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2728		       struct sk_buff *skb);
2729
2730#define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2731static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
2732				   struct sk_buff *skb)
2733{
2734#define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)			| \
2735			   (1UL << SOCK_RCVTSTAMP)			| \
2736			   (1UL << SOCK_RCVMARK))
2737#define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2738			   SOF_TIMESTAMPING_RAW_HARDWARE)
2739
2740	if (sk->sk_flags & FLAGS_RECV_CMSGS || sk->sk_tsflags & TSFLAGS_ANY)
2741		__sock_recv_cmsgs(msg, sk, skb);
2742	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2743		sock_write_timestamp(sk, skb->tstamp);
2744	else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2745		sock_write_timestamp(sk, 0);
2746}
2747
2748void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2749
2750/**
2751 * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2752 * @sk:		socket sending this packet
2753 * @tsflags:	timestamping flags to use
2754 * @tx_flags:	completed with instructions for time stamping
2755 * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
2756 *
2757 * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2758 */
2759static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2760				      __u8 *tx_flags, __u32 *tskey)
2761{
2762	if (unlikely(tsflags)) {
2763		__sock_tx_timestamp(tsflags, tx_flags);
2764		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2765		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2766			*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
2767	}
2768	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2769		*tx_flags |= SKBTX_WIFI_STATUS;
2770}
2771
2772static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2773				     __u8 *tx_flags)
2774{
2775	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2776}
2777
2778static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2779{
2780	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2781			   &skb_shinfo(skb)->tskey);
2782}
2783
2784static inline bool sk_is_tcp(const struct sock *sk)
2785{
2786	return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP;
2787}
2788
2789/**
2790 * sk_eat_skb - Release a skb if it is no longer needed
2791 * @sk: socket to eat this skb from
2792 * @skb: socket buffer to eat
2793 *
2794 * This routine must be called with interrupts disabled or with the socket
2795 * locked so that the sk_buff queue operation is ok.
2796*/
2797static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2798{
2799	__skb_unlink(skb, &sk->sk_receive_queue);
 
 
 
 
 
 
2800	__kfree_skb(skb);
2801}
2802
 
 
 
 
 
 
 
 
 
 
 
 
2803static inline bool
2804skb_sk_is_prefetched(struct sk_buff *skb)
2805{
2806#ifdef CONFIG_INET
2807	return skb->destructor == sock_pfree;
2808#else
2809	return false;
2810#endif /* CONFIG_INET */
2811}
2812
2813/* This helper checks if a socket is a full socket,
2814 * ie _not_ a timewait or request socket.
2815 */
2816static inline bool sk_fullsock(const struct sock *sk)
2817{
2818	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2819}
2820
2821static inline bool
2822sk_is_refcounted(struct sock *sk)
2823{
2824	/* Only full sockets have sk->sk_flags. */
2825	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2826}
2827
2828/**
2829 * skb_steal_sock - steal a socket from an sk_buff
2830 * @skb: sk_buff to steal the socket from
2831 * @refcounted: is set to true if the socket is reference-counted
2832 */
2833static inline struct sock *
2834skb_steal_sock(struct sk_buff *skb, bool *refcounted)
2835{
2836	if (skb->sk) {
2837		struct sock *sk = skb->sk;
2838
2839		*refcounted = true;
2840		if (skb_sk_is_prefetched(skb))
2841			*refcounted = sk_is_refcounted(sk);
2842		skb->destructor = NULL;
2843		skb->sk = NULL;
2844		return sk;
2845	}
2846	*refcounted = false;
2847	return NULL;
2848}
2849
2850/* Checks if this SKB belongs to an HW offloaded socket
2851 * and whether any SW fallbacks are required based on dev.
2852 * Check decrypted mark in case skb_orphan() cleared socket.
2853 */
2854static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2855						   struct net_device *dev)
2856{
2857#ifdef CONFIG_SOCK_VALIDATE_XMIT
2858	struct sock *sk = skb->sk;
2859
2860	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2861		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2862#ifdef CONFIG_TLS_DEVICE
2863	} else if (unlikely(skb->decrypted)) {
2864		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2865		kfree_skb(skb);
2866		skb = NULL;
2867#endif
2868	}
2869#endif
2870
2871	return skb;
2872}
2873
2874/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2875 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2876 */
2877static inline bool sk_listener(const struct sock *sk)
2878{
2879	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2880}
2881
2882void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2883int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2884		       int type);
2885
2886bool sk_ns_capable(const struct sock *sk,
2887		   struct user_namespace *user_ns, int cap);
2888bool sk_capable(const struct sock *sk, int cap);
2889bool sk_net_capable(const struct sock *sk, int cap);
2890
2891void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2892
2893/* Take into consideration the size of the struct sk_buff overhead in the
2894 * determination of these values, since that is non-constant across
2895 * platforms.  This makes socket queueing behavior and performance
2896 * not depend upon such differences.
2897 */
2898#define _SK_MEM_PACKETS		256
2899#define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
2900#define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2901#define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2902
2903extern __u32 sysctl_wmem_max;
2904extern __u32 sysctl_rmem_max;
2905
2906extern int sysctl_tstamp_allow_data;
2907extern int sysctl_optmem_max;
2908
2909extern __u32 sysctl_wmem_default;
2910extern __u32 sysctl_rmem_default;
2911
2912#define SKB_FRAG_PAGE_ORDER	get_order(32768)
2913DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2914
2915static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2916{
2917	/* Does this proto have per netns sysctl_wmem ? */
2918	if (proto->sysctl_wmem_offset)
2919		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
2920
2921	return READ_ONCE(*proto->sysctl_wmem);
2922}
2923
2924static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2925{
2926	/* Does this proto have per netns sysctl_rmem ? */
2927	if (proto->sysctl_rmem_offset)
2928		return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
2929
2930	return READ_ONCE(*proto->sysctl_rmem);
2931}
2932
2933/* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2934 * Some wifi drivers need to tweak it to get more chunks.
2935 * They can use this helper from their ndo_start_xmit()
2936 */
2937static inline void sk_pacing_shift_update(struct sock *sk, int val)
2938{
2939	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2940		return;
2941	WRITE_ONCE(sk->sk_pacing_shift, val);
2942}
2943
2944/* if a socket is bound to a device, check that the given device
2945 * index is either the same or that the socket is bound to an L3
2946 * master device and the given device index is also enslaved to
2947 * that L3 master
2948 */
2949static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2950{
2951	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
2952	int mdif;
2953
2954	if (!bound_dev_if || bound_dev_if == dif)
2955		return true;
2956
2957	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2958	if (mdif && mdif == bound_dev_if)
2959		return true;
2960
2961	return false;
2962}
2963
2964void sock_def_readable(struct sock *sk);
2965
2966int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
2967void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
2968int sock_set_timestamping(struct sock *sk, int optname,
2969			  struct so_timestamping timestamping);
2970
2971void sock_enable_timestamps(struct sock *sk);
2972void sock_no_linger(struct sock *sk);
2973void sock_set_keepalive(struct sock *sk);
2974void sock_set_priority(struct sock *sk, u32 priority);
2975void sock_set_rcvbuf(struct sock *sk, int val);
2976void sock_set_mark(struct sock *sk, u32 val);
2977void sock_set_reuseaddr(struct sock *sk);
2978void sock_set_reuseport(struct sock *sk);
2979void sock_set_sndtimeo(struct sock *sk, s64 secs);
2980
2981int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
2982
2983int sock_get_timeout(long timeo, void *optval, bool old_timeval);
2984int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
2985			   sockptr_t optval, int optlen, bool old_timeval);
2986
2987static inline bool sk_is_readable(struct sock *sk)
2988{
2989	if (sk->sk_prot->sock_is_readable)
2990		return sk->sk_prot->sock_is_readable(sk);
2991	return false;
2992}
2993#endif	/* _SOCK_H */