1/*
   2 * INET		An implementation of the TCP/IP protocol suite for the LINUX
   3 *		operating system.  INET is implemented using the  BSD Socket
   4 *		interface as the means of communication with the user level.
   5 *
   6 *		Definitions for the AF_INET socket handler.
   7 *
   8 * Version:	@(#)sock.h	1.0.4	05/13/93
   9 *
  10 * Authors:	Ross Biro
  11 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
  13 *		Florian La Roche <flla@stud.uni-sb.de>
  14 *
  15 * Fixes:
  16 *		Alan Cox	:	Volatiles in skbuff pointers. See
  17 *					skbuff comments. May be overdone,
  18 *					better to prove they can be removed
  19 *					than the reverse.
  20 *		Alan Cox	:	Added a zapped field for tcp to note
  21 *					a socket is reset and must stay shut up
  22 *		Alan Cox	:	New fields for options
  23 *	Pauline Middelink	:	identd support
  24 *		Alan Cox	:	Eliminate low level recv/recvfrom
  25 *		David S. Miller	:	New socket lookup architecture.
  26 *              Steve Whitehouse:       Default routines for sock_ops
  27 *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
  28 *              			protinfo be just a void pointer, as the
  29 *              			protocol specific parts were moved to
  30 *              			respective headers and ipv4/v6, etc now
  31 *              			use private slabcaches for its socks
  32 *              Pedro Hortas	:	New flags field for socket options
  33 *
  34 *
  35 *		This program is free software; you can redistribute it and/or
  36 *		modify it under the terms of the GNU General Public License
  37 *		as published by the Free Software Foundation; either version
  38 *		2 of the License, or (at your option) any later version.
  39 */
  40#ifndef _SOCK_H
  41#define _SOCK_H
  42
  43#include <linux/hardirq.h>
  44#include <linux/kernel.h>
  45#include <linux/list.h>
  46#include <linux/list_nulls.h>
  47#include <linux/timer.h>
  48#include <linux/cache.h>
  49#include <linux/bitops.h>
  50#include <linux/lockdep.h>
  51#include <linux/netdevice.h>
  52#include <linux/skbuff.h>	/* struct sk_buff */
  53#include <linux/mm.h>
  54#include <linux/security.h>
  55#include <linux/slab.h>
  56#include <linux/uaccess.h>
 
  57#include <linux/memcontrol.h>
  58#include <linux/res_counter.h>
  59#include <linux/static_key.h>
  60#include <linux/aio.h>
  61#include <linux/sched.h>
  62
 
 
  63#include <linux/filter.h>
  64#include <linux/rculist_nulls.h>
  65#include <linux/poll.h>
  66
  67#include <linux/atomic.h>
 
  68#include <net/dst.h>
  69#include <net/checksum.h>
 
 
 
 
  70
  71struct cgroup;
  72struct cgroup_subsys;
  73#ifdef CONFIG_NET
  74int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
  75void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg);
  76#else
  77static inline
  78int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
  79{
  80	return 0;
  81}
  82static inline
  83void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
  84{
  85}
  86#endif
  87/*
  88 * This structure really needs to be cleaned up.
  89 * Most of it is for TCP, and not used by any of
  90 * the other protocols.
  91 */
  92
  93/* Define this to get the SOCK_DBG debugging facility. */
  94#define SOCK_DEBUGGING
  95#ifdef SOCK_DEBUGGING
  96#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
  97					printk(KERN_DEBUG msg); } while (0)
  98#else
  99/* Validate arguments and do nothing */
 100static inline __printf(2, 3)
 101void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
 102{
 103}
 104#endif
 105
 106/* This is the per-socket lock.  The spinlock provides a synchronization
 107 * between user contexts and software interrupt processing, whereas the
 108 * mini-semaphore synchronizes multiple users amongst themselves.
 109 */
 110typedef struct {
 111	spinlock_t		slock;
 112	int			owned;
 113	wait_queue_head_t	wq;
 114	/*
 115	 * We express the mutex-alike socket_lock semantics
 116	 * to the lock validator by explicitly managing
 117	 * the slock as a lock variant (in addition to
 118	 * the slock itself):
 119	 */
 120#ifdef CONFIG_DEBUG_LOCK_ALLOC
 121	struct lockdep_map dep_map;
 122#endif
 123} socket_lock_t;
 124
 125struct sock;
 126struct proto;
 127struct net;
 128
 129typedef __u32 __bitwise __portpair;
 130typedef __u64 __bitwise __addrpair;
 131
 132/**
 133 *	struct sock_common - minimal network layer representation of sockets
 134 *	@skc_daddr: Foreign IPv4 addr
 135 *	@skc_rcv_saddr: Bound local IPv4 addr
 136 *	@skc_hash: hash value used with various protocol lookup tables
 137 *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
 138 *	@skc_dport: placeholder for inet_dport/tw_dport
 139 *	@skc_num: placeholder for inet_num/tw_num
 140 *	@skc_family: network address family
 141 *	@skc_state: Connection state
 142 *	@skc_reuse: %SO_REUSEADDR setting
 143 *	@skc_reuseport: %SO_REUSEPORT setting
 144 *	@skc_bound_dev_if: bound device index if != 0
 145 *	@skc_bind_node: bind hash linkage for various protocol lookup tables
 146 *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
 147 *	@skc_prot: protocol handlers inside a network family
 148 *	@skc_net: reference to the network namespace of this socket
 149 *	@skc_node: main hash linkage for various protocol lookup tables
 150 *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
 151 *	@skc_tx_queue_mapping: tx queue number for this connection
 
 
 
 
 152 *	@skc_refcnt: reference count
 153 *
 154 *	This is the minimal network layer representation of sockets, the header
 155 *	for struct sock and struct inet_timewait_sock.
 156 */
 157struct sock_common {
 158	/* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
 159	 * address on 64bit arches : cf INET_MATCH()
 160	 */
 161	union {
 162		__addrpair	skc_addrpair;
 163		struct {
 164			__be32	skc_daddr;
 165			__be32	skc_rcv_saddr;
 166		};
 167	};
 168	union  {
 169		unsigned int	skc_hash;
 170		__u16		skc_u16hashes[2];
 171	};
 172	/* skc_dport && skc_num must be grouped as well */
 173	union {
 174		__portpair	skc_portpair;
 175		struct {
 176			__be16	skc_dport;
 177			__u16	skc_num;
 178		};
 179	};
 180
 181	unsigned short		skc_family;
 182	volatile unsigned char	skc_state;
 183	unsigned char		skc_reuse:4;
 184	unsigned char		skc_reuseport:4;
 
 
 185	int			skc_bound_dev_if;
 186	union {
 187		struct hlist_node	skc_bind_node;
 188		struct hlist_nulls_node skc_portaddr_node;
 189	};
 190	struct proto		*skc_prot;
 191#ifdef CONFIG_NET_NS
 192	struct net	 	*skc_net;
 193#endif
 194
 195#if IS_ENABLED(CONFIG_IPV6)
 196	struct in6_addr		skc_v6_daddr;
 197	struct in6_addr		skc_v6_rcv_saddr;
 198#endif
 199
 
 
 
 
 
 
 
 
 
 
 
 
 200	/*
 201	 * fields between dontcopy_begin/dontcopy_end
 202	 * are not copied in sock_copy()
 203	 */
 204	/* private: */
 205	int			skc_dontcopy_begin[0];
 206	/* public: */
 207	union {
 208		struct hlist_node	skc_node;
 209		struct hlist_nulls_node skc_nulls_node;
 210	};
 211	int			skc_tx_queue_mapping;
 212	atomic_t		skc_refcnt;
 
 
 
 
 
 
 213	/* private: */
 214	int                     skc_dontcopy_end[0];
 
 
 
 
 
 215	/* public: */
 216};
 217
 218struct cg_proto;
 219/**
 220  *	struct sock - network layer representation of sockets
 221  *	@__sk_common: shared layout with inet_timewait_sock
 222  *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
 223  *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
 224  *	@sk_lock:	synchronizer
 
 225  *	@sk_rcvbuf: size of receive buffer in bytes
 226  *	@sk_wq: sock wait queue and async head
 227  *	@sk_rx_dst: receive input route used by early demux
 228  *	@sk_dst_cache: destination cache
 229  *	@sk_dst_lock: destination cache lock
 230  *	@sk_policy: flow policy
 231  *	@sk_receive_queue: incoming packets
 232  *	@sk_wmem_alloc: transmit queue bytes committed
 
 233  *	@sk_write_queue: Packet sending queue
 234  *	@sk_async_wait_queue: DMA copied packets
 235  *	@sk_omem_alloc: "o" is "option" or "other"
 236  *	@sk_wmem_queued: persistent queue size
 237  *	@sk_forward_alloc: space allocated forward
 238  *	@sk_napi_id: id of the last napi context to receive data for sk
 239  *	@sk_ll_usec: usecs to busypoll when there is no data
 240  *	@sk_allocation: allocation mode
 241  *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
 
 242  *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
 243  *	@sk_sndbuf: size of send buffer in bytes
 244  *	@sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
 245  *		   %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
 246  *	@sk_no_check: %SO_NO_CHECK setting, whether or not checkup packets
 
 247  *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
 248  *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
 249  *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
 250  *	@sk_gso_max_size: Maximum GSO segment size to build
 251  *	@sk_gso_max_segs: Maximum number of GSO segments
 
 252  *	@sk_lingertime: %SO_LINGER l_linger setting
 253  *	@sk_backlog: always used with the per-socket spinlock held
 254  *	@sk_callback_lock: used with the callbacks in the end of this struct
 255  *	@sk_error_queue: rarely used
 256  *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
 257  *			  IPV6_ADDRFORM for instance)
 258  *	@sk_err: last error
 259  *	@sk_err_soft: errors that don't cause failure but are the cause of a
 260  *		      persistent failure not just 'timed out'
 261  *	@sk_drops: raw/udp drops counter
 262  *	@sk_ack_backlog: current listen backlog
 263  *	@sk_max_ack_backlog: listen backlog set in listen()
 
 264  *	@sk_priority: %SO_PRIORITY setting
 265  *	@sk_cgrp_prioidx: socket group's priority map index
 266  *	@sk_type: socket type (%SOCK_STREAM, etc)
 267  *	@sk_protocol: which protocol this socket belongs in this network family
 268  *	@sk_peer_pid: &struct pid for this socket's peer
 269  *	@sk_peer_cred: %SO_PEERCRED setting
 270  *	@sk_rcvlowat: %SO_RCVLOWAT setting
 271  *	@sk_rcvtimeo: %SO_RCVTIMEO setting
 272  *	@sk_sndtimeo: %SO_SNDTIMEO setting
 273  *	@sk_rxhash: flow hash received from netif layer
 274  *	@sk_filter: socket filtering instructions
 275  *	@sk_protinfo: private area, net family specific, when not using slab
 276  *	@sk_timer: sock cleanup timer
 277  *	@sk_stamp: time stamp of last packet received
 
 
 
 278  *	@sk_socket: Identd and reporting IO signals
 279  *	@sk_user_data: RPC layer private data
 280  *	@sk_frag: cached page frag
 281  *	@sk_peek_off: current peek_offset value
 282  *	@sk_send_head: front of stuff to transmit
 283  *	@sk_security: used by security modules
 284  *	@sk_mark: generic packet mark
 285  *	@sk_classid: this socket's cgroup classid
 286  *	@sk_cgrp: this socket's cgroup-specific proto data
 287  *	@sk_write_pending: a write to stream socket waits to start
 288  *	@sk_state_change: callback to indicate change in the state of the sock
 289  *	@sk_data_ready: callback to indicate there is data to be processed
 290  *	@sk_write_space: callback to indicate there is bf sending space available
 291  *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
 292  *	@sk_backlog_rcv: callback to process the backlog
 293  *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
 294 */
 
 
 295struct sock {
 296	/*
 297	 * Now struct inet_timewait_sock also uses sock_common, so please just
 298	 * don't add nothing before this first member (__sk_common) --acme
 299	 */
 300	struct sock_common	__sk_common;
 301#define sk_node			__sk_common.skc_node
 302#define sk_nulls_node		__sk_common.skc_nulls_node
 303#define sk_refcnt		__sk_common.skc_refcnt
 304#define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
 305
 306#define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
 307#define sk_dontcopy_end		__sk_common.skc_dontcopy_end
 308#define sk_hash			__sk_common.skc_hash
 309#define sk_portpair		__sk_common.skc_portpair
 310#define sk_num			__sk_common.skc_num
 311#define sk_dport		__sk_common.skc_dport
 312#define sk_addrpair		__sk_common.skc_addrpair
 313#define sk_daddr		__sk_common.skc_daddr
 314#define sk_rcv_saddr		__sk_common.skc_rcv_saddr
 315#define sk_family		__sk_common.skc_family
 316#define sk_state		__sk_common.skc_state
 317#define sk_reuse		__sk_common.skc_reuse
 318#define sk_reuseport		__sk_common.skc_reuseport
 
 
 319#define sk_bound_dev_if		__sk_common.skc_bound_dev_if
 320#define sk_bind_node		__sk_common.skc_bind_node
 321#define sk_prot			__sk_common.skc_prot
 322#define sk_net			__sk_common.skc_net
 323#define sk_v6_daddr		__sk_common.skc_v6_daddr
 324#define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
 
 
 
 
 325
 326	socket_lock_t		sk_lock;
 
 
 
 327	struct sk_buff_head	sk_receive_queue;
 328	/*
 329	 * The backlog queue is special, it is always used with
 330	 * the per-socket spinlock held and requires low latency
 331	 * access. Therefore we special case it's implementation.
 332	 * Note : rmem_alloc is in this structure to fill a hole
 333	 * on 64bit arches, not because its logically part of
 334	 * backlog.
 335	 */
 336	struct {
 337		atomic_t	rmem_alloc;
 338		int		len;
 339		struct sk_buff	*head;
 340		struct sk_buff	*tail;
 341	} sk_backlog;
 342#define sk_rmem_alloc sk_backlog.rmem_alloc
 
 343	int			sk_forward_alloc;
 344#ifdef CONFIG_RPS
 345	__u32			sk_rxhash;
 346#endif
 347#ifdef CONFIG_NET_RX_BUSY_POLL
 348	unsigned int		sk_napi_id;
 349	unsigned int		sk_ll_usec;
 
 
 350#endif
 351	atomic_t		sk_drops;
 352	int			sk_rcvbuf;
 353
 354	struct sk_filter __rcu	*sk_filter;
 355	struct socket_wq __rcu	*sk_wq;
 356
 357#ifdef CONFIG_NET_DMA
 358	struct sk_buff_head	sk_async_wait_queue;
 359#endif
 360
 361#ifdef CONFIG_XFRM
 362	struct xfrm_policy	*sk_policy[2];
 363#endif
 364	unsigned long 		sk_flags;
 365	struct dst_entry	*sk_rx_dst;
 366	struct dst_entry __rcu	*sk_dst_cache;
 367	spinlock_t		sk_dst_lock;
 368	atomic_t		sk_wmem_alloc;
 369	atomic_t		sk_omem_alloc;
 370	int			sk_sndbuf;
 371	struct sk_buff_head	sk_write_queue;
 372	kmemcheck_bitfield_begin(flags);
 373	unsigned int		sk_shutdown  : 2,
 374				sk_no_check  : 2,
 375				sk_userlocks : 4,
 376				sk_protocol  : 8,
 377				sk_type      : 16;
 378	kmemcheck_bitfield_end(flags);
 379	int			sk_wmem_queued;
 380	gfp_t			sk_allocation;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 381	u32			sk_pacing_rate; /* bytes per second */
 382	u32			sk_max_pacing_rate;
 
 383	netdev_features_t	sk_route_caps;
 384	netdev_features_t	sk_route_nocaps;
 
 385	int			sk_gso_type;
 386	unsigned int		sk_gso_max_size;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 387	u16			sk_gso_max_segs;
 388	int			sk_rcvlowat;
 389	unsigned long	        sk_lingertime;
 390	struct sk_buff_head	sk_error_queue;
 391	struct proto		*sk_prot_creator;
 392	rwlock_t		sk_callback_lock;
 393	int			sk_err,
 394				sk_err_soft;
 395	unsigned short		sk_ack_backlog;
 396	unsigned short		sk_max_ack_backlog;
 397	__u32			sk_priority;
 398#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
 399	__u32			sk_cgrp_prioidx;
 400#endif
 401	struct pid		*sk_peer_pid;
 402	const struct cred	*sk_peer_cred;
 403	long			sk_rcvtimeo;
 404	long			sk_sndtimeo;
 405	void			*sk_protinfo;
 406	struct timer_list	sk_timer;
 407	ktime_t			sk_stamp;
 
 
 
 
 408	struct socket		*sk_socket;
 409	void			*sk_user_data;
 410	struct page_frag	sk_frag;
 411	struct sk_buff		*sk_send_head;
 412	__s32			sk_peek_off;
 413	int			sk_write_pending;
 414#ifdef CONFIG_SECURITY
 415	void			*sk_security;
 416#endif
 417	__u32			sk_mark;
 418	u32			sk_classid;
 419	struct cg_proto		*sk_cgrp;
 420	void			(*sk_state_change)(struct sock *sk);
 421	void			(*sk_data_ready)(struct sock *sk);
 422	void			(*sk_write_space)(struct sock *sk);
 423	void			(*sk_error_report)(struct sock *sk);
 424	int			(*sk_backlog_rcv)(struct sock *sk,
 425						  struct sk_buff *skb);
 426	void                    (*sk_destruct)(struct sock *sk);
 
 
 
 
 
 
 
 
 427};
 428
 429#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
 430
 431#define rcu_dereference_sk_user_data(sk)	rcu_dereference(__sk_user_data((sk)))
 432#define rcu_assign_sk_user_data(sk, ptr)	rcu_assign_pointer(__sk_user_data((sk)), ptr)
 433
 434/*
 435 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
 436 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
 437 * on a socket means that the socket will reuse everybody else's port
 438 * without looking at the other's sk_reuse value.
 439 */
 440
 441#define SK_NO_REUSE	0
 442#define SK_CAN_REUSE	1
 443#define SK_FORCE_REUSE	2
 444
 
 
 445static inline int sk_peek_offset(struct sock *sk, int flags)
 446{
 447	if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
 448		return sk->sk_peek_off;
 449	else
 450		return 0;
 
 451}
 452
 453static inline void sk_peek_offset_bwd(struct sock *sk, int val)
 454{
 455	if (sk->sk_peek_off >= 0) {
 456		if (sk->sk_peek_off >= val)
 457			sk->sk_peek_off -= val;
 458		else
 459			sk->sk_peek_off = 0;
 460	}
 461}
 462
 463static inline void sk_peek_offset_fwd(struct sock *sk, int val)
 464{
 465	if (sk->sk_peek_off >= 0)
 466		sk->sk_peek_off += val;
 467}
 468
 469/*
 470 * Hashed lists helper routines
 471 */
 472static inline struct sock *sk_entry(const struct hlist_node *node)
 473{
 474	return hlist_entry(node, struct sock, sk_node);
 475}
 476
 477static inline struct sock *__sk_head(const struct hlist_head *head)
 478{
 479	return hlist_entry(head->first, struct sock, sk_node);
 480}
 481
 482static inline struct sock *sk_head(const struct hlist_head *head)
 483{
 484	return hlist_empty(head) ? NULL : __sk_head(head);
 485}
 486
 487static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
 488{
 489	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
 490}
 491
 492static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
 493{
 494	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
 495}
 496
 497static inline struct sock *sk_next(const struct sock *sk)
 498{
 499	return sk->sk_node.next ?
 500		hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
 501}
 502
 503static inline struct sock *sk_nulls_next(const struct sock *sk)
 504{
 505	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
 506		hlist_nulls_entry(sk->sk_nulls_node.next,
 507				  struct sock, sk_nulls_node) :
 508		NULL;
 509}
 510
 511static inline bool sk_unhashed(const struct sock *sk)
 512{
 513	return hlist_unhashed(&sk->sk_node);
 514}
 515
 516static inline bool sk_hashed(const struct sock *sk)
 517{
 518	return !sk_unhashed(sk);
 519}
 520
 521static inline void sk_node_init(struct hlist_node *node)
 522{
 523	node->pprev = NULL;
 524}
 525
 526static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
 527{
 528	node->pprev = NULL;
 529}
 530
 531static inline void __sk_del_node(struct sock *sk)
 532{
 533	__hlist_del(&sk->sk_node);
 534}
 535
 536/* NB: equivalent to hlist_del_init_rcu */
 537static inline bool __sk_del_node_init(struct sock *sk)
 538{
 539	if (sk_hashed(sk)) {
 540		__sk_del_node(sk);
 541		sk_node_init(&sk->sk_node);
 542		return true;
 543	}
 544	return false;
 545}
 546
 547/* Grab socket reference count. This operation is valid only
 548   when sk is ALREADY grabbed f.e. it is found in hash table
 549   or a list and the lookup is made under lock preventing hash table
 550   modifications.
 551 */
 552
 553static inline void sock_hold(struct sock *sk)
 554{
 555	atomic_inc(&sk->sk_refcnt);
 556}
 557
 558/* Ungrab socket in the context, which assumes that socket refcnt
 559   cannot hit zero, f.e. it is true in context of any socketcall.
 560 */
 561static inline void __sock_put(struct sock *sk)
 562{
 563	atomic_dec(&sk->sk_refcnt);
 564}
 565
 566static inline bool sk_del_node_init(struct sock *sk)
 567{
 568	bool rc = __sk_del_node_init(sk);
 569
 570	if (rc) {
 571		/* paranoid for a while -acme */
 572		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
 573		__sock_put(sk);
 574	}
 575	return rc;
 576}
 577#define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
 578
 579static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
 580{
 581	if (sk_hashed(sk)) {
 582		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
 583		return true;
 584	}
 585	return false;
 586}
 587
 588static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
 589{
 590	bool rc = __sk_nulls_del_node_init_rcu(sk);
 591
 592	if (rc) {
 593		/* paranoid for a while -acme */
 594		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
 595		__sock_put(sk);
 596	}
 597	return rc;
 598}
 599
 600static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
 601{
 602	hlist_add_head(&sk->sk_node, list);
 603}
 604
 605static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
 606{
 607	sock_hold(sk);
 608	__sk_add_node(sk, list);
 609}
 610
 611static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
 612{
 613	sock_hold(sk);
 614	hlist_add_head_rcu(&sk->sk_node, list);
 
 
 
 
 615}
 616
 617static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 618{
 619	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
 620}
 621
 622static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 623{
 624	sock_hold(sk);
 625	__sk_nulls_add_node_rcu(sk, list);
 626}
 627
 628static inline void __sk_del_bind_node(struct sock *sk)
 629{
 630	__hlist_del(&sk->sk_bind_node);
 631}
 632
 633static inline void sk_add_bind_node(struct sock *sk,
 634					struct hlist_head *list)
 635{
 636	hlist_add_head(&sk->sk_bind_node, list);
 637}
 638
 639#define sk_for_each(__sk, list) \
 640	hlist_for_each_entry(__sk, list, sk_node)
 641#define sk_for_each_rcu(__sk, list) \
 642	hlist_for_each_entry_rcu(__sk, list, sk_node)
 643#define sk_nulls_for_each(__sk, node, list) \
 644	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
 645#define sk_nulls_for_each_rcu(__sk, node, list) \
 646	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
 647#define sk_for_each_from(__sk) \
 648	hlist_for_each_entry_from(__sk, sk_node)
 649#define sk_nulls_for_each_from(__sk, node) \
 650	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
 651		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
 652#define sk_for_each_safe(__sk, tmp, list) \
 653	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
 654#define sk_for_each_bound(__sk, list) \
 655	hlist_for_each_entry(__sk, list, sk_bind_node)
 656
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 657static inline struct user_namespace *sk_user_ns(struct sock *sk)
 658{
 659	/* Careful only use this in a context where these parameters
 660	 * can not change and must all be valid, such as recvmsg from
 661	 * userspace.
 662	 */
 663	return sk->sk_socket->file->f_cred->user_ns;
 664}
 665
 666/* Sock flags */
 667enum sock_flags {
 668	SOCK_DEAD,
 669	SOCK_DONE,
 670	SOCK_URGINLINE,
 671	SOCK_KEEPOPEN,
 672	SOCK_LINGER,
 673	SOCK_DESTROY,
 674	SOCK_BROADCAST,
 675	SOCK_TIMESTAMP,
 676	SOCK_ZAPPED,
 677	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
 678	SOCK_DBG, /* %SO_DEBUG setting */
 679	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
 680	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
 681	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
 682	SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
 683	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
 684	SOCK_TIMESTAMPING_TX_HARDWARE,  /* %SOF_TIMESTAMPING_TX_HARDWARE */
 685	SOCK_TIMESTAMPING_TX_SOFTWARE,  /* %SOF_TIMESTAMPING_TX_SOFTWARE */
 686	SOCK_TIMESTAMPING_RX_HARDWARE,  /* %SOF_TIMESTAMPING_RX_HARDWARE */
 687	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
 688	SOCK_TIMESTAMPING_SOFTWARE,     /* %SOF_TIMESTAMPING_SOFTWARE */
 689	SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
 690	SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
 691	SOCK_FASYNC, /* fasync() active */
 692	SOCK_RXQ_OVFL,
 693	SOCK_ZEROCOPY, /* buffers from userspace */
 694	SOCK_WIFI_STATUS, /* push wifi status to userspace */
 695	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
 696		     * Will use last 4 bytes of packet sent from
 697		     * user-space instead.
 698		     */
 699	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
 700	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
 
 701};
 702
 
 
 703static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
 704{
 705	nsk->sk_flags = osk->sk_flags;
 706}
 707
 708static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
 709{
 710	__set_bit(flag, &sk->sk_flags);
 711}
 712
 713static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
 714{
 715	__clear_bit(flag, &sk->sk_flags);
 716}
 717
 718static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
 719{
 720	return test_bit(flag, &sk->sk_flags);
 721}
 722
 723#ifdef CONFIG_NET
 724extern struct static_key memalloc_socks;
 725static inline int sk_memalloc_socks(void)
 726{
 727	return static_key_false(&memalloc_socks);
 728}
 729#else
 730
 731static inline int sk_memalloc_socks(void)
 732{
 733	return 0;
 734}
 735
 736#endif
 737
 738static inline gfp_t sk_gfp_atomic(struct sock *sk, gfp_t gfp_mask)
 739{
 740	return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC);
 741}
 742
 743static inline void sk_acceptq_removed(struct sock *sk)
 744{
 745	sk->sk_ack_backlog--;
 746}
 747
 748static inline void sk_acceptq_added(struct sock *sk)
 749{
 750	sk->sk_ack_backlog++;
 751}
 752
 753static inline bool sk_acceptq_is_full(const struct sock *sk)
 754{
 755	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
 756}
 757
 758/*
 759 * Compute minimal free write space needed to queue new packets.
 760 */
 761static inline int sk_stream_min_wspace(const struct sock *sk)
 762{
 763	return sk->sk_wmem_queued >> 1;
 764}
 765
 766static inline int sk_stream_wspace(const struct sock *sk)
 767{
 768	return sk->sk_sndbuf - sk->sk_wmem_queued;
 769}
 770
 771void sk_stream_write_space(struct sock *sk);
 772
 773/* OOB backlog add */
 774static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
 775{
 776	/* dont let skb dst not refcounted, we are going to leave rcu lock */
 777	skb_dst_force(skb);
 778
 779	if (!sk->sk_backlog.tail)
 780		sk->sk_backlog.head = skb;
 781	else
 782		sk->sk_backlog.tail->next = skb;
 783
 784	sk->sk_backlog.tail = skb;
 785	skb->next = NULL;
 786}
 787
 788/*
 789 * Take into account size of receive queue and backlog queue
 790 * Do not take into account this skb truesize,
 791 * to allow even a single big packet to come.
 792 */
 793static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb,
 794				     unsigned int limit)
 795{
 796	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
 797
 798	return qsize > limit;
 799}
 800
 801/* The per-socket spinlock must be held here. */
 802static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
 803					      unsigned int limit)
 804{
 805	if (sk_rcvqueues_full(sk, skb, limit))
 806		return -ENOBUFS;
 807
 
 
 
 
 
 
 
 
 808	__sk_add_backlog(sk, skb);
 809	sk->sk_backlog.len += skb->truesize;
 810	return 0;
 811}
 812
 813int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 814
 815static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 816{
 817	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
 818		return __sk_backlog_rcv(sk, skb);
 819
 820	return sk->sk_backlog_rcv(sk, skb);
 821}
 822
 823static inline void sock_rps_record_flow_hash(__u32 hash)
 824{
 825#ifdef CONFIG_RPS
 826	struct rps_sock_flow_table *sock_flow_table;
 827
 828	rcu_read_lock();
 829	sock_flow_table = rcu_dereference(rps_sock_flow_table);
 830	rps_record_sock_flow(sock_flow_table, hash);
 831	rcu_read_unlock();
 832#endif
 833}
 834
 835static inline void sock_rps_reset_flow_hash(__u32 hash)
 836{
 837#ifdef CONFIG_RPS
 838	struct rps_sock_flow_table *sock_flow_table;
 839
 840	rcu_read_lock();
 841	sock_flow_table = rcu_dereference(rps_sock_flow_table);
 842	rps_reset_sock_flow(sock_flow_table, hash);
 843	rcu_read_unlock();
 844#endif
 845}
 846
 847static inline void sock_rps_record_flow(const struct sock *sk)
 848{
 849#ifdef CONFIG_RPS
 850	sock_rps_record_flow_hash(sk->sk_rxhash);
 851#endif
 852}
 853
 854static inline void sock_rps_reset_flow(const struct sock *sk)
 855{
 856#ifdef CONFIG_RPS
 857	sock_rps_reset_flow_hash(sk->sk_rxhash);
 
 
 
 
 
 
 858#endif
 859}
 860
 861static inline void sock_rps_save_rxhash(struct sock *sk,
 862					const struct sk_buff *skb)
 863{
 864#ifdef CONFIG_RPS
 865	if (unlikely(sk->sk_rxhash != skb->hash)) {
 866		sock_rps_reset_flow(sk);
 867		sk->sk_rxhash = skb->hash;
 868	}
 869#endif
 870}
 871
 872static inline void sock_rps_reset_rxhash(struct sock *sk)
 873{
 874#ifdef CONFIG_RPS
 875	sock_rps_reset_flow(sk);
 876	sk->sk_rxhash = 0;
 877#endif
 878}
 879
 880#define sk_wait_event(__sk, __timeo, __condition)			\
 881	({	int __rc;						\
 882		release_sock(__sk);					\
 883		__rc = __condition;					\
 884		if (!__rc) {						\
 885			*(__timeo) = schedule_timeout(*(__timeo));	\
 
 
 886		}							\
 
 887		lock_sock(__sk);					\
 888		__rc = __condition;					\
 889		__rc;							\
 890	})
 891
 892int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
 893int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
 894void sk_stream_wait_close(struct sock *sk, long timeo_p);
 895int sk_stream_error(struct sock *sk, int flags, int err);
 896void sk_stream_kill_queues(struct sock *sk);
 897void sk_set_memalloc(struct sock *sk);
 898void sk_clear_memalloc(struct sock *sk);
 899
 900int sk_wait_data(struct sock *sk, long *timeo);
 
 
 
 
 
 
 
 
 
 
 
 901
 902struct request_sock_ops;
 903struct timewait_sock_ops;
 904struct inet_hashinfo;
 905struct raw_hashinfo;
 
 906struct module;
 907
 908/*
 909 * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
 910 * un-modified. Special care is taken when initializing object to zero.
 911 */
 912static inline void sk_prot_clear_nulls(struct sock *sk, int size)
 913{
 914	if (offsetof(struct sock, sk_node.next) != 0)
 915		memset(sk, 0, offsetof(struct sock, sk_node.next));
 916	memset(&sk->sk_node.pprev, 0,
 917	       size - offsetof(struct sock, sk_node.pprev));
 918}
 919
 920/* Networking protocol blocks we attach to sockets.
 921 * socket layer -> transport layer interface
 922 * transport -> network interface is defined by struct inet_proto
 923 */
 924struct proto {
 925	void			(*close)(struct sock *sk,
 926					long timeout);
 
 
 
 927	int			(*connect)(struct sock *sk,
 928					struct sockaddr *uaddr,
 929					int addr_len);
 930	int			(*disconnect)(struct sock *sk, int flags);
 931
 932	struct sock *		(*accept)(struct sock *sk, int flags, int *err);
 
 933
 934	int			(*ioctl)(struct sock *sk, int cmd,
 935					 unsigned long arg);
 936	int			(*init)(struct sock *sk);
 937	void			(*destroy)(struct sock *sk);
 938	void			(*shutdown)(struct sock *sk, int how);
 939	int			(*setsockopt)(struct sock *sk, int level,
 940					int optname, char __user *optval,
 941					unsigned int optlen);
 942	int			(*getsockopt)(struct sock *sk, int level,
 943					int optname, char __user *optval,
 944					int __user *option);
 
 945#ifdef CONFIG_COMPAT
 946	int			(*compat_setsockopt)(struct sock *sk,
 947					int level,
 948					int optname, char __user *optval,
 949					unsigned int optlen);
 950	int			(*compat_getsockopt)(struct sock *sk,
 951					int level,
 952					int optname, char __user *optval,
 953					int __user *option);
 954	int			(*compat_ioctl)(struct sock *sk,
 955					unsigned int cmd, unsigned long arg);
 956#endif
 957	int			(*sendmsg)(struct kiocb *iocb, struct sock *sk,
 958					   struct msghdr *msg, size_t len);
 959	int			(*recvmsg)(struct kiocb *iocb, struct sock *sk,
 960					   struct msghdr *msg,
 961					   size_t len, int noblock, int flags,
 962					   int *addr_len);
 963	int			(*sendpage)(struct sock *sk, struct page *page,
 964					int offset, size_t size, int flags);
 965	int			(*bind)(struct sock *sk,
 966					struct sockaddr *uaddr, int addr_len);
 967
 968	int			(*backlog_rcv) (struct sock *sk,
 969						struct sk_buff *skb);
 970
 971	void		(*release_cb)(struct sock *sk);
 972	void		(*mtu_reduced)(struct sock *sk);
 973
 974	/* Keeping track of sk's, looking them up, and port selection methods. */
 975	void			(*hash)(struct sock *sk);
 976	void			(*unhash)(struct sock *sk);
 977	void			(*rehash)(struct sock *sk);
 978	int			(*get_port)(struct sock *sk, unsigned short snum);
 979	void			(*clear_sk)(struct sock *sk, int size);
 980
 981	/* Keeping track of sockets in use */
 982#ifdef CONFIG_PROC_FS
 983	unsigned int		inuse_idx;
 984#endif
 985
 986	bool			(*stream_memory_free)(const struct sock *sk);
 
 987	/* Memory pressure */
 988	void			(*enter_memory_pressure)(struct sock *sk);
 
 989	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
 990	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
 991	/*
 992	 * Pressure flag: try to collapse.
 993	 * Technical note: it is used by multiple contexts non atomically.
 994	 * All the __sk_mem_schedule() is of this nature: accounting
 995	 * is strict, actions are advisory and have some latency.
 996	 */
 997	int			*memory_pressure;
 998	long			*sysctl_mem;
 
 999	int			*sysctl_wmem;
1000	int			*sysctl_rmem;
 
 
 
1001	int			max_header;
1002	bool			no_autobind;
1003
1004	struct kmem_cache	*slab;
1005	unsigned int		obj_size;
1006	int			slab_flags;
 
 
1007
1008	struct percpu_counter	*orphan_count;
1009
1010	struct request_sock_ops	*rsk_prot;
1011	struct timewait_sock_ops *twsk_prot;
1012
1013	union {
1014		struct inet_hashinfo	*hashinfo;
1015		struct udp_table	*udp_table;
1016		struct raw_hashinfo	*raw_hash;
 
1017	} h;
1018
1019	struct module		*owner;
1020
1021	char			name[32];
1022
1023	struct list_head	node;
1024#ifdef SOCK_REFCNT_DEBUG
1025	atomic_t		socks;
1026#endif
1027#ifdef CONFIG_MEMCG_KMEM
1028	/*
1029	 * cgroup specific init/deinit functions. Called once for all
1030	 * protocols that implement it, from cgroups populate function.
1031	 * This function has to setup any files the protocol want to
1032	 * appear in the kmem cgroup filesystem.
1033	 */
1034	int			(*init_cgroup)(struct mem_cgroup *memcg,
1035					       struct cgroup_subsys *ss);
1036	void			(*destroy_cgroup)(struct mem_cgroup *memcg);
1037	struct cg_proto		*(*proto_cgroup)(struct mem_cgroup *memcg);
1038#endif
1039};
1040
1041/*
1042 * Bits in struct cg_proto.flags
1043 */
1044enum cg_proto_flags {
1045	/* Currently active and new sockets should be assigned to cgroups */
1046	MEMCG_SOCK_ACTIVE,
1047	/* It was ever activated; we must disarm static keys on destruction */
1048	MEMCG_SOCK_ACTIVATED,
1049};
1050
1051struct cg_proto {
1052	struct res_counter	memory_allocated;	/* Current allocated memory. */
1053	struct percpu_counter	sockets_allocated;	/* Current number of sockets. */
1054	int			memory_pressure;
1055	long			sysctl_mem[3];
1056	unsigned long		flags;
1057	/*
1058	 * memcg field is used to find which memcg we belong directly
1059	 * Each memcg struct can hold more than one cg_proto, so container_of
1060	 * won't really cut.
1061	 *
1062	 * The elegant solution would be having an inverse function to
1063	 * proto_cgroup in struct proto, but that means polluting the structure
1064	 * for everybody, instead of just for memcg users.
1065	 */
1066	struct mem_cgroup	*memcg;
1067};
1068
1069int proto_register(struct proto *prot, int alloc_slab);
1070void proto_unregister(struct proto *prot);
1071
1072static inline bool memcg_proto_active(struct cg_proto *cg_proto)
1073{
1074	return test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
1075}
1076
1077static inline bool memcg_proto_activated(struct cg_proto *cg_proto)
1078{
1079	return test_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags);
1080}
1081
1082#ifdef SOCK_REFCNT_DEBUG
1083static inline void sk_refcnt_debug_inc(struct sock *sk)
1084{
1085	atomic_inc(&sk->sk_prot->socks);
1086}
1087
1088static inline void sk_refcnt_debug_dec(struct sock *sk)
1089{
1090	atomic_dec(&sk->sk_prot->socks);
1091	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1092	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1093}
1094
1095static inline void sk_refcnt_debug_release(const struct sock *sk)
1096{
1097	if (atomic_read(&sk->sk_refcnt) != 1)
1098		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1099		       sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
1100}
1101#else /* SOCK_REFCNT_DEBUG */
1102#define sk_refcnt_debug_inc(sk) do { } while (0)
1103#define sk_refcnt_debug_dec(sk) do { } while (0)
1104#define sk_refcnt_debug_release(sk) do { } while (0)
1105#endif /* SOCK_REFCNT_DEBUG */
1106
1107#if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_NET)
1108extern struct static_key memcg_socket_limit_enabled;
1109static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1110					       struct cg_proto *cg_proto)
1111{
1112	return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg));
1113}
1114#define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled)
1115#else
1116#define mem_cgroup_sockets_enabled 0
1117static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1118					       struct cg_proto *cg_proto)
1119{
1120	return NULL;
1121}
1122#endif
1123
1124static inline bool sk_stream_memory_free(const struct sock *sk)
1125{
1126	if (sk->sk_wmem_queued >= sk->sk_sndbuf)
1127		return false;
1128
1129	return sk->sk_prot->stream_memory_free ?
1130		sk->sk_prot->stream_memory_free(sk) : true;
1131}
1132
1133static inline bool sk_stream_is_writeable(const struct sock *sk)
1134{
1135	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1136	       sk_stream_memory_free(sk);
1137}
1138
 
 
 
 
 
 
 
 
 
 
1139
1140static inline bool sk_has_memory_pressure(const struct sock *sk)
1141{
1142	return sk->sk_prot->memory_pressure != NULL;
1143}
1144
1145static inline bool sk_under_memory_pressure(const struct sock *sk)
1146{
1147	if (!sk->sk_prot->memory_pressure)
1148		return false;
1149
1150	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1151		return !!sk->sk_cgrp->memory_pressure;
 
1152
1153	return !!*sk->sk_prot->memory_pressure;
1154}
1155
1156static inline void sk_leave_memory_pressure(struct sock *sk)
1157{
1158	int *memory_pressure = sk->sk_prot->memory_pressure;
1159
1160	if (!memory_pressure)
1161		return;
1162
1163	if (*memory_pressure)
1164		*memory_pressure = 0;
1165
1166	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1167		struct cg_proto *cg_proto = sk->sk_cgrp;
1168		struct proto *prot = sk->sk_prot;
1169
1170		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1171			cg_proto->memory_pressure = 0;
1172	}
1173
1174}
1175
1176static inline void sk_enter_memory_pressure(struct sock *sk)
1177{
1178	if (!sk->sk_prot->enter_memory_pressure)
1179		return;
1180
1181	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1182		struct cg_proto *cg_proto = sk->sk_cgrp;
1183		struct proto *prot = sk->sk_prot;
1184
1185		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1186			cg_proto->memory_pressure = 1;
1187	}
1188
1189	sk->sk_prot->enter_memory_pressure(sk);
1190}
1191
1192static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1193{
1194	long *prot = sk->sk_prot->sysctl_mem;
1195	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1196		prot = sk->sk_cgrp->sysctl_mem;
1197	return prot[index];
1198}
1199
1200static inline void memcg_memory_allocated_add(struct cg_proto *prot,
1201					      unsigned long amt,
1202					      int *parent_status)
1203{
1204	struct res_counter *fail;
1205	int ret;
1206
1207	ret = res_counter_charge_nofail(&prot->memory_allocated,
1208					amt << PAGE_SHIFT, &fail);
1209	if (ret < 0)
1210		*parent_status = OVER_LIMIT;
1211}
1212
1213static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
1214					      unsigned long amt)
1215{
1216	res_counter_uncharge(&prot->memory_allocated, amt << PAGE_SHIFT);
1217}
1218
1219static inline u64 memcg_memory_allocated_read(struct cg_proto *prot)
1220{
1221	u64 ret;
1222	ret = res_counter_read_u64(&prot->memory_allocated, RES_USAGE);
1223	return ret >> PAGE_SHIFT;
1224}
1225
1226static inline long
1227sk_memory_allocated(const struct sock *sk)
1228{
1229	struct proto *prot = sk->sk_prot;
1230	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1231		return memcg_memory_allocated_read(sk->sk_cgrp);
1232
1233	return atomic_long_read(prot->memory_allocated);
1234}
1235
1236static inline long
1237sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status)
1238{
1239	struct proto *prot = sk->sk_prot;
1240
1241	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1242		memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status);
1243		/* update the root cgroup regardless */
1244		atomic_long_add_return(amt, prot->memory_allocated);
1245		return memcg_memory_allocated_read(sk->sk_cgrp);
1246	}
1247
1248	return atomic_long_add_return(amt, prot->memory_allocated);
1249}
1250
1251static inline void
1252sk_memory_allocated_sub(struct sock *sk, int amt)
1253{
1254	struct proto *prot = sk->sk_prot;
1255
1256	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1257		memcg_memory_allocated_sub(sk->sk_cgrp, amt);
1258
1259	atomic_long_sub(amt, prot->memory_allocated);
1260}
1261
1262static inline void sk_sockets_allocated_dec(struct sock *sk)
1263{
1264	struct proto *prot = sk->sk_prot;
1265
1266	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1267		struct cg_proto *cg_proto = sk->sk_cgrp;
1268
1269		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1270			percpu_counter_dec(&cg_proto->sockets_allocated);
1271	}
1272
1273	percpu_counter_dec(prot->sockets_allocated);
1274}
1275
1276static inline void sk_sockets_allocated_inc(struct sock *sk)
1277{
1278	struct proto *prot = sk->sk_prot;
1279
1280	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1281		struct cg_proto *cg_proto = sk->sk_cgrp;
1282
1283		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1284			percpu_counter_inc(&cg_proto->sockets_allocated);
1285	}
1286
1287	percpu_counter_inc(prot->sockets_allocated);
1288}
1289
1290static inline int
1291sk_sockets_allocated_read_positive(struct sock *sk)
1292{
1293	struct proto *prot = sk->sk_prot;
1294
1295	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1296		return percpu_counter_read_positive(&sk->sk_cgrp->sockets_allocated);
1297
1298	return percpu_counter_read_positive(prot->sockets_allocated);
1299}
1300
1301static inline int
1302proto_sockets_allocated_sum_positive(struct proto *prot)
1303{
1304	return percpu_counter_sum_positive(prot->sockets_allocated);
1305}
1306
1307static inline long
1308proto_memory_allocated(struct proto *prot)
1309{
1310	return atomic_long_read(prot->memory_allocated);
1311}
1312
1313static inline bool
1314proto_memory_pressure(struct proto *prot)
1315{
1316	if (!prot->memory_pressure)
1317		return false;
1318	return !!*prot->memory_pressure;
1319}
1320
1321
1322#ifdef CONFIG_PROC_FS
1323/* Called with local bh disabled */
1324void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1325int sock_prot_inuse_get(struct net *net, struct proto *proto);
 
1326#else
1327static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1328		int inc)
1329{
1330}
1331#endif
1332
1333
1334/* With per-bucket locks this operation is not-atomic, so that
1335 * this version is not worse.
1336 */
1337static inline void __sk_prot_rehash(struct sock *sk)
1338{
1339	sk->sk_prot->unhash(sk);
1340	sk->sk_prot->hash(sk);
1341}
1342
1343void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
1344
1345/* About 10 seconds */
1346#define SOCK_DESTROY_TIME (10*HZ)
1347
1348/* Sockets 0-1023 can't be bound to unless you are superuser */
1349#define PROT_SOCK	1024
1350
1351#define SHUTDOWN_MASK	3
1352#define RCV_SHUTDOWN	1
1353#define SEND_SHUTDOWN	2
1354
1355#define SOCK_SNDBUF_LOCK	1
1356#define SOCK_RCVBUF_LOCK	2
1357#define SOCK_BINDADDR_LOCK	4
1358#define SOCK_BINDPORT_LOCK	8
1359
1360/* sock_iocb: used to kick off async processing of socket ios */
1361struct sock_iocb {
1362	struct list_head	list;
1363
1364	int			flags;
1365	int			size;
1366	struct socket		*sock;
1367	struct sock		*sk;
1368	struct scm_cookie	*scm;
1369	struct msghdr		*msg, async_msg;
1370	struct kiocb		*kiocb;
1371};
1372
1373static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
1374{
1375	return (struct sock_iocb *)iocb->private;
1376}
1377
1378static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
1379{
1380	return si->kiocb;
1381}
1382
1383struct socket_alloc {
1384	struct socket socket;
1385	struct inode vfs_inode;
1386};
1387
1388static inline struct socket *SOCKET_I(struct inode *inode)
1389{
1390	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1391}
1392
1393static inline struct inode *SOCK_INODE(struct socket *socket)
1394{
1395	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1396}
1397
1398/*
1399 * Functions for memory accounting
1400 */
 
1401int __sk_mem_schedule(struct sock *sk, int size, int kind);
1402void __sk_mem_reclaim(struct sock *sk);
 
1403
1404#define SK_MEM_QUANTUM ((int)PAGE_SIZE)
 
 
 
1405#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1406#define SK_MEM_SEND	0
1407#define SK_MEM_RECV	1
1408
 
 
 
 
 
 
 
 
 
 
 
 
 
1409static inline int sk_mem_pages(int amt)
1410{
1411	return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1412}
1413
1414static inline bool sk_has_account(struct sock *sk)
1415{
1416	/* return true if protocol supports memory accounting */
1417	return !!sk->sk_prot->memory_allocated;
1418}
1419
1420static inline bool sk_wmem_schedule(struct sock *sk, int size)
1421{
1422	if (!sk_has_account(sk))
1423		return true;
1424	return size <= sk->sk_forward_alloc ||
1425		__sk_mem_schedule(sk, size, SK_MEM_SEND);
1426}
1427
1428static inline bool
1429sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1430{
1431	if (!sk_has_account(sk))
1432		return true;
1433	return size<= sk->sk_forward_alloc ||
1434		__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1435		skb_pfmemalloc(skb);
1436}
1437
1438static inline void sk_mem_reclaim(struct sock *sk)
1439{
1440	if (!sk_has_account(sk))
1441		return;
1442	if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1443		__sk_mem_reclaim(sk);
1444}
1445
1446static inline void sk_mem_reclaim_partial(struct sock *sk)
1447{
1448	if (!sk_has_account(sk))
1449		return;
1450	if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1451		__sk_mem_reclaim(sk);
1452}
1453
1454static inline void sk_mem_charge(struct sock *sk, int size)
1455{
1456	if (!sk_has_account(sk))
1457		return;
1458	sk->sk_forward_alloc -= size;
1459}
1460
1461static inline void sk_mem_uncharge(struct sock *sk, int size)
1462{
1463	if (!sk_has_account(sk))
1464		return;
1465	sk->sk_forward_alloc += size;
 
 
 
 
 
 
 
 
 
 
1466}
1467
1468static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1469{
1470	sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1471	sk->sk_wmem_queued -= skb->truesize;
1472	sk_mem_uncharge(sk, skb->truesize);
1473	__kfree_skb(skb);
1474}
1475
1476/* Used by processes to "lock" a socket state, so that
1477 * interrupts and bottom half handlers won't change it
1478 * from under us. It essentially blocks any incoming
1479 * packets, so that we won't get any new data or any
1480 * packets that change the state of the socket.
1481 *
1482 * While locked, BH processing will add new packets to
1483 * the backlog queue.  This queue is processed by the
1484 * owner of the socket lock right before it is released.
1485 *
1486 * Since ~2.3.5 it is also exclusive sleep lock serializing
1487 * accesses from user process context.
1488 */
1489#define sock_owned_by_user(sk)	((sk)->sk_lock.owned)
1490
1491static inline void sock_release_ownership(struct sock *sk)
1492{
1493	sk->sk_lock.owned = 0;
 
 
 
 
 
1494}
1495
1496/*
1497 * Macro so as to not evaluate some arguments when
1498 * lockdep is not enabled.
1499 *
1500 * Mark both the sk_lock and the sk_lock.slock as a
1501 * per-address-family lock class.
1502 */
1503#define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1504do {									\
1505	sk->sk_lock.owned = 0;						\
1506	init_waitqueue_head(&sk->sk_lock.wq);				\
1507	spin_lock_init(&(sk)->sk_lock.slock);				\
1508	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1509			sizeof((sk)->sk_lock));				\
1510	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1511				(skey), (sname));				\
1512	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1513} while (0)
1514
 
 
 
 
 
 
 
 
1515void lock_sock_nested(struct sock *sk, int subclass);
1516
1517static inline void lock_sock(struct sock *sk)
1518{
1519	lock_sock_nested(sk, 0);
1520}
1521
1522void release_sock(struct sock *sk);
1523
1524/* BH context may only use the following locking interface. */
1525#define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1526#define bh_lock_sock_nested(__sk) \
1527				spin_lock_nested(&((__sk)->sk_lock.slock), \
1528				SINGLE_DEPTH_NESTING)
1529#define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1530
1531bool lock_sock_fast(struct sock *sk);
1532/**
1533 * unlock_sock_fast - complement of lock_sock_fast
1534 * @sk: socket
1535 * @slow: slow mode
1536 *
1537 * fast unlock socket for user context.
1538 * If slow mode is on, we call regular release_sock()
1539 */
1540static inline void unlock_sock_fast(struct sock *sk, bool slow)
1541{
1542	if (slow)
1543		release_sock(sk);
1544	else
1545		spin_unlock_bh(&sk->sk_lock.slock);
1546}
1547
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1548
1549struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1550		      struct proto *prot);
1551void sk_free(struct sock *sk);
1552void sk_release_kernel(struct sock *sk);
1553struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
 
1554
1555struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1556			     gfp_t priority);
 
1557void sock_wfree(struct sk_buff *skb);
 
 
1558void skb_orphan_partial(struct sk_buff *skb);
1559void sock_rfree(struct sk_buff *skb);
 
 
1560void sock_edemux(struct sk_buff *skb);
 
 
 
1561
1562int sock_setsockopt(struct socket *sock, int level, int op,
1563		    char __user *optval, unsigned int optlen);
1564
1565int sock_getsockopt(struct socket *sock, int level, int op,
1566		    char __user *optval, int __user *optlen);
1567struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1568				    int noblock, int *errcode);
1569struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1570				     unsigned long data_len, int noblock,
1571				     int *errcode, int max_page_order);
1572void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1573void sock_kfree_s(struct sock *sk, void *mem, int size);
 
1574void sk_send_sigurg(struct sock *sk);
1575
 
 
 
 
 
 
 
 
 
 
1576/*
1577 * Functions to fill in entries in struct proto_ops when a protocol
1578 * does not implement a particular function.
1579 */
1580int sock_no_bind(struct socket *, struct sockaddr *, int);
1581int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1582int sock_no_socketpair(struct socket *, struct socket *);
1583int sock_no_accept(struct socket *, struct socket *, int);
1584int sock_no_getname(struct socket *, struct sockaddr *, int *, int);
1585unsigned int sock_no_poll(struct file *, struct socket *,
1586			  struct poll_table_struct *);
1587int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1588int sock_no_listen(struct socket *, int);
1589int sock_no_shutdown(struct socket *, int);
1590int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1591int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1592int sock_no_sendmsg(struct kiocb *, struct socket *, struct msghdr *, size_t);
1593int sock_no_recvmsg(struct kiocb *, struct socket *, struct msghdr *, size_t,
1594		    int);
1595int sock_no_mmap(struct file *file, struct socket *sock,
1596		 struct vm_area_struct *vma);
1597ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1598			 size_t size, int flags);
 
 
1599
1600/*
1601 * Functions to fill in entries in struct proto_ops when a protocol
1602 * uses the inet style.
1603 */
1604int sock_common_getsockopt(struct socket *sock, int level, int optname,
1605				  char __user *optval, int __user *optlen);
1606int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1607			       struct msghdr *msg, size_t size, int flags);
1608int sock_common_setsockopt(struct socket *sock, int level, int optname,
1609				  char __user *optval, unsigned int optlen);
1610int compat_sock_common_getsockopt(struct socket *sock, int level,
1611		int optname, char __user *optval, int __user *optlen);
1612int compat_sock_common_setsockopt(struct socket *sock, int level,
1613		int optname, char __user *optval, unsigned int optlen);
1614
1615void sk_common_release(struct sock *sk);
1616
1617/*
1618 *	Default socket callbacks and setup code
1619 */
1620
1621/* Initialise core socket variables */
1622void sock_init_data(struct socket *sock, struct sock *sk);
1623
1624/*
1625 * Socket reference counting postulates.
1626 *
1627 * * Each user of socket SHOULD hold a reference count.
1628 * * Each access point to socket (an hash table bucket, reference from a list,
1629 *   running timer, skb in flight MUST hold a reference count.
1630 * * When reference count hits 0, it means it will never increase back.
1631 * * When reference count hits 0, it means that no references from
1632 *   outside exist to this socket and current process on current CPU
1633 *   is last user and may/should destroy this socket.
1634 * * sk_free is called from any context: process, BH, IRQ. When
1635 *   it is called, socket has no references from outside -> sk_free
1636 *   may release descendant resources allocated by the socket, but
1637 *   to the time when it is called, socket is NOT referenced by any
1638 *   hash tables, lists etc.
1639 * * Packets, delivered from outside (from network or from another process)
1640 *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1641 *   when they sit in queue. Otherwise, packets will leak to hole, when
1642 *   socket is looked up by one cpu and unhasing is made by another CPU.
1643 *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1644 *   (leak to backlog). Packet socket does all the processing inside
1645 *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1646 *   use separate SMP lock, so that they are prone too.
1647 */
1648
1649/* Ungrab socket and destroy it, if it was the last reference. */
1650static inline void sock_put(struct sock *sk)
1651{
1652	if (atomic_dec_and_test(&sk->sk_refcnt))
1653		sk_free(sk);
1654}
1655/* Generic version of sock_put(), dealing with all sockets
1656 * (TCP_TIMEWAIT, ESTABLISHED...)
1657 */
1658void sock_gen_put(struct sock *sk);
1659
1660int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested);
 
 
 
 
 
 
1661
1662static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1663{
1664	sk->sk_tx_queue_mapping = tx_queue;
1665}
1666
1667static inline void sk_tx_queue_clear(struct sock *sk)
1668{
1669	sk->sk_tx_queue_mapping = -1;
1670}
1671
1672static inline int sk_tx_queue_get(const struct sock *sk)
1673{
1674	return sk ? sk->sk_tx_queue_mapping : -1;
1675}
1676
1677static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1678{
1679	sk_tx_queue_clear(sk);
1680	sk->sk_socket = sock;
1681}
1682
1683static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1684{
1685	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1686	return &rcu_dereference_raw(sk->sk_wq)->wait;
1687}
1688/* Detach socket from process context.
1689 * Announce socket dead, detach it from wait queue and inode.
1690 * Note that parent inode held reference count on this struct sock,
1691 * we do not release it in this function, because protocol
1692 * probably wants some additional cleanups or even continuing
1693 * to work with this socket (TCP).
1694 */
1695static inline void sock_orphan(struct sock *sk)
1696{
1697	write_lock_bh(&sk->sk_callback_lock);
1698	sock_set_flag(sk, SOCK_DEAD);
1699	sk_set_socket(sk, NULL);
1700	sk->sk_wq  = NULL;
1701	write_unlock_bh(&sk->sk_callback_lock);
1702}
1703
1704static inline void sock_graft(struct sock *sk, struct socket *parent)
1705{
 
1706	write_lock_bh(&sk->sk_callback_lock);
1707	sk->sk_wq = parent->wq;
1708	parent->sk = sk;
1709	sk_set_socket(sk, parent);
 
1710	security_sock_graft(sk, parent);
1711	write_unlock_bh(&sk->sk_callback_lock);
1712}
1713
1714kuid_t sock_i_uid(struct sock *sk);
1715unsigned long sock_i_ino(struct sock *sk);
1716
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1717static inline struct dst_entry *
1718__sk_dst_get(struct sock *sk)
1719{
1720	return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1721						       lockdep_is_held(&sk->sk_lock.slock));
1722}
1723
1724static inline struct dst_entry *
1725sk_dst_get(struct sock *sk)
1726{
1727	struct dst_entry *dst;
1728
1729	rcu_read_lock();
1730	dst = rcu_dereference(sk->sk_dst_cache);
1731	if (dst)
1732		dst_hold(dst);
1733	rcu_read_unlock();
1734	return dst;
1735}
1736
1737static inline void dst_negative_advice(struct sock *sk)
1738{
1739	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1740
 
 
1741	if (dst && dst->ops->negative_advice) {
1742		ndst = dst->ops->negative_advice(dst);
1743
1744		if (ndst != dst) {
1745			rcu_assign_pointer(sk->sk_dst_cache, ndst);
1746			sk_tx_queue_clear(sk);
 
1747		}
1748	}
1749}
1750
1751static inline void
1752__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1753{
1754	struct dst_entry *old_dst;
1755
1756	sk_tx_queue_clear(sk);
1757	/*
1758	 * This can be called while sk is owned by the caller only,
1759	 * with no state that can be checked in a rcu_dereference_check() cond
1760	 */
1761	old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1762	rcu_assign_pointer(sk->sk_dst_cache, dst);
1763	dst_release(old_dst);
1764}
1765
1766static inline void
1767sk_dst_set(struct sock *sk, struct dst_entry *dst)
1768{
1769	spin_lock(&sk->sk_dst_lock);
1770	__sk_dst_set(sk, dst);
1771	spin_unlock(&sk->sk_dst_lock);
 
 
 
1772}
1773
1774static inline void
1775__sk_dst_reset(struct sock *sk)
1776{
1777	__sk_dst_set(sk, NULL);
1778}
1779
1780static inline void
1781sk_dst_reset(struct sock *sk)
1782{
1783	spin_lock(&sk->sk_dst_lock);
1784	__sk_dst_reset(sk);
1785	spin_unlock(&sk->sk_dst_lock);
1786}
1787
1788struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1789
1790struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1791
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1792static inline bool sk_can_gso(const struct sock *sk)
1793{
1794	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1795}
1796
1797void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1798
1799static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1800{
1801	sk->sk_route_nocaps |= flags;
1802	sk->sk_route_caps &= ~flags;
1803}
1804
1805static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1806					   char __user *from, char *to,
1807					   int copy, int offset)
1808{
1809	if (skb->ip_summed == CHECKSUM_NONE) {
1810		int err = 0;
1811		__wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1812		if (err)
1813			return err;
1814		skb->csum = csum_block_add(skb->csum, csum, offset);
1815	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1816		if (!access_ok(VERIFY_READ, from, copy) ||
1817		    __copy_from_user_nocache(to, from, copy))
1818			return -EFAULT;
1819	} else if (copy_from_user(to, from, copy))
1820		return -EFAULT;
1821
1822	return 0;
1823}
1824
1825static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1826				       char __user *from, int copy)
1827{
1828	int err, offset = skb->len;
1829
1830	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1831				       copy, offset);
1832	if (err)
1833		__skb_trim(skb, offset);
1834
1835	return err;
1836}
1837
1838static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1839					   struct sk_buff *skb,
1840					   struct page *page,
1841					   int off, int copy)
1842{
1843	int err;
1844
1845	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1846				       copy, skb->len);
1847	if (err)
1848		return err;
1849
1850	skb->len	     += copy;
1851	skb->data_len	     += copy;
1852	skb->truesize	     += copy;
1853	sk->sk_wmem_queued   += copy;
1854	sk_mem_charge(sk, copy);
1855	return 0;
1856}
1857
1858static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1859				   struct sk_buff *skb, struct page *page,
1860				   int off, int copy)
1861{
1862	if (skb->ip_summed == CHECKSUM_NONE) {
1863		int err = 0;
1864		__wsum csum = csum_and_copy_from_user(from,
1865						     page_address(page) + off,
1866							    copy, 0, &err);
1867		if (err)
1868			return err;
1869		skb->csum = csum_block_add(skb->csum, csum, skb->len);
1870	} else if (copy_from_user(page_address(page) + off, from, copy))
1871		return -EFAULT;
1872
1873	skb->len	     += copy;
1874	skb->data_len	     += copy;
1875	skb->truesize	     += copy;
1876	sk->sk_wmem_queued   += copy;
1877	sk_mem_charge(sk, copy);
1878	return 0;
1879}
1880
1881/**
1882 * sk_wmem_alloc_get - returns write allocations
1883 * @sk: socket
1884 *
1885 * Returns sk_wmem_alloc minus initial offset of one
1886 */
1887static inline int sk_wmem_alloc_get(const struct sock *sk)
1888{
1889	return atomic_read(&sk->sk_wmem_alloc) - 1;
1890}
1891
1892/**
1893 * sk_rmem_alloc_get - returns read allocations
1894 * @sk: socket
1895 *
1896 * Returns sk_rmem_alloc
1897 */
1898static inline int sk_rmem_alloc_get(const struct sock *sk)
1899{
1900	return atomic_read(&sk->sk_rmem_alloc);
1901}
1902
1903/**
1904 * sk_has_allocations - check if allocations are outstanding
1905 * @sk: socket
1906 *
1907 * Returns true if socket has write or read allocations
1908 */
1909static inline bool sk_has_allocations(const struct sock *sk)
1910{
1911	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1912}
1913
1914/**
1915 * wq_has_sleeper - check if there are any waiting processes
1916 * @wq: struct socket_wq
1917 *
1918 * Returns true if socket_wq has waiting processes
1919 *
1920 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1921 * barrier call. They were added due to the race found within the tcp code.
1922 *
1923 * Consider following tcp code paths:
1924 *
1925 * CPU1                  CPU2
1926 *
1927 * sys_select            receive packet
 
1928 *   ...                 ...
1929 *   __add_wait_queue    update tp->rcv_nxt
1930 *   ...                 ...
1931 *   tp->rcv_nxt check   sock_def_readable
1932 *   ...                 {
1933 *   schedule               rcu_read_lock();
1934 *                          wq = rcu_dereference(sk->sk_wq);
1935 *                          if (wq && waitqueue_active(&wq->wait))
1936 *                              wake_up_interruptible(&wq->wait)
1937 *                          ...
1938 *                       }
1939 *
1940 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1941 * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
1942 * could then endup calling schedule and sleep forever if there are no more
1943 * data on the socket.
1944 *
1945 */
1946static inline bool wq_has_sleeper(struct socket_wq *wq)
1947{
1948	/* We need to be sure we are in sync with the
1949	 * add_wait_queue modifications to the wait queue.
1950	 *
1951	 * This memory barrier is paired in the sock_poll_wait.
1952	 */
1953	smp_mb();
1954	return wq && waitqueue_active(&wq->wait);
1955}
1956
1957/**
1958 * sock_poll_wait - place memory barrier behind the poll_wait call.
1959 * @filp:           file
1960 * @wait_address:   socket wait queue
1961 * @p:              poll_table
1962 *
1963 * See the comments in the wq_has_sleeper function.
1964 */
1965static inline void sock_poll_wait(struct file *filp,
1966		wait_queue_head_t *wait_address, poll_table *p)
1967{
1968	if (!poll_does_not_wait(p) && wait_address) {
1969		poll_wait(filp, wait_address, p);
1970		/* We need to be sure we are in sync with the
1971		 * socket flags modification.
1972		 *
1973		 * This memory barrier is paired in the wq_has_sleeper.
1974		 */
1975		smp_mb();
1976	}
1977}
1978
 
 
 
 
 
 
 
 
 
 
1979/*
1980 *	Queue a received datagram if it will fit. Stream and sequenced
1981 *	protocols can't normally use this as they need to fit buffers in
1982 *	and play with them.
1983 *
1984 *	Inlined as it's very short and called for pretty much every
1985 *	packet ever received.
1986 */
1987
1988static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1989{
1990	skb_orphan(skb);
1991	skb->sk = sk;
1992	skb->destructor = sock_wfree;
1993	/*
1994	 * We used to take a refcount on sk, but following operation
1995	 * is enough to guarantee sk_free() wont free this sock until
1996	 * all in-flight packets are completed
1997	 */
1998	atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1999}
2000
2001static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2002{
2003	skb_orphan(skb);
2004	skb->sk = sk;
2005	skb->destructor = sock_rfree;
2006	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2007	sk_mem_charge(sk, skb->truesize);
2008}
2009
2010void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2011		    unsigned long expires);
2012
2013void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2014
 
 
 
 
 
2015int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2016
2017int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
 
2018
2019/*
2020 *	Recover an error report and clear atomically
2021 */
2022
2023static inline int sock_error(struct sock *sk)
2024{
2025	int err;
2026	if (likely(!sk->sk_err))
2027		return 0;
2028	err = xchg(&sk->sk_err, 0);
2029	return -err;
2030}
2031
2032static inline unsigned long sock_wspace(struct sock *sk)
2033{
2034	int amt = 0;
2035
2036	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2037		amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
2038		if (amt < 0)
2039			amt = 0;
2040	}
2041	return amt;
2042}
2043
2044static inline void sk_wake_async(struct sock *sk, int how, int band)
 
 
 
 
2045{
2046	if (sock_flag(sk, SOCK_FASYNC))
2047		sock_wake_async(sk->sk_socket, how, band);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2048}
2049
2050/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2051 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2052 * Note: for send buffers, TCP works better if we can build two skbs at
2053 * minimum.
2054 */
2055#define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2056
2057#define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2058#define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2059
2060static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2061{
2062	if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
2063		sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2064		sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
2065	}
2066}
2067
2068struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
 
2069
2070/**
2071 * sk_page_frag - return an appropriate page_frag
2072 * @sk: socket
2073 *
2074 * If socket allocation mode allows current thread to sleep, it means its
2075 * safe to use the per task page_frag instead of the per socket one.
2076 */
2077static inline struct page_frag *sk_page_frag(struct sock *sk)
2078{
2079	if (sk->sk_allocation & __GFP_WAIT)
2080		return &current->task_frag;
2081
2082	return &sk->sk_frag;
2083}
2084
2085bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2086
 
 
 
 
2087/*
2088 *	Default write policy as shown to user space via poll/select/SIGIO
2089 */
2090static inline bool sock_writeable(const struct sock *sk)
2091{
2092	return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2093}
2094
2095static inline gfp_t gfp_any(void)
2096{
2097	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2098}
2099
2100static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2101{
2102	return noblock ? 0 : sk->sk_rcvtimeo;
2103}
2104
2105static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2106{
2107	return noblock ? 0 : sk->sk_sndtimeo;
2108}
2109
2110static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2111{
2112	return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2113}
2114
2115/* Alas, with timeout socket operations are not restartable.
2116 * Compare this to poll().
2117 */
2118static inline int sock_intr_errno(long timeo)
2119{
2120	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2121}
2122
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2123void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2124			   struct sk_buff *skb);
2125void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2126			     struct sk_buff *skb);
2127
2128static inline void
2129sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2130{
2131	ktime_t kt = skb->tstamp;
2132	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2133
2134	/*
2135	 * generate control messages if
2136	 * - receive time stamping in software requested (SOCK_RCVTSTAMP
2137	 *   or SOCK_TIMESTAMPING_RX_SOFTWARE)
2138	 * - software time stamp available and wanted
2139	 *   (SOCK_TIMESTAMPING_SOFTWARE)
2140	 * - hardware time stamps available and wanted
2141	 *   (SOCK_TIMESTAMPING_SYS_HARDWARE or
2142	 *   SOCK_TIMESTAMPING_RAW_HARDWARE)
2143	 */
2144	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2145	    sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
2146	    (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
2147	    (hwtstamps->hwtstamp.tv64 &&
2148	     sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
2149	    (hwtstamps->syststamp.tv64 &&
2150	     sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
2151		__sock_recv_timestamp(msg, sk, skb);
2152	else
2153		sk->sk_stamp = kt;
2154
2155	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2156		__sock_recv_wifi_status(msg, sk, skb);
2157}
2158
2159void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2160			      struct sk_buff *skb);
2161
 
2162static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2163					  struct sk_buff *skb)
2164{
2165#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)			| \
2166			   (1UL << SOCK_RCVTSTAMP)			| \
2167			   (1UL << SOCK_TIMESTAMPING_SOFTWARE)		| \
2168			   (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE)	| \
2169			   (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE))
2170
2171	if (sk->sk_flags & FLAGS_TS_OR_DROPS)
2172		__sock_recv_ts_and_drops(msg, sk, skb);
2173	else
2174		sk->sk_stamp = skb->tstamp;
 
 
2175}
2176
 
 
2177/**
2178 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2179 * @sk:		socket sending this packet
2180 * @tx_flags:	filled with instructions for time stamping
 
2181 *
2182 * Currently only depends on SOCK_TIMESTAMPING* flags.
2183 */
2184void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
 
 
 
 
 
 
 
2185
2186/**
2187 * sk_eat_skb - Release a skb if it is no longer needed
2188 * @sk: socket to eat this skb from
2189 * @skb: socket buffer to eat
2190 * @copied_early: flag indicating whether DMA operations copied this data early
2191 *
2192 * This routine must be called with interrupts disabled or with the socket
2193 * locked so that the sk_buff queue operation is ok.
2194*/
2195#ifdef CONFIG_NET_DMA
2196static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2197{
2198	__skb_unlink(skb, &sk->sk_receive_queue);
2199	if (!copied_early)
2200		__kfree_skb(skb);
2201	else
2202		__skb_queue_tail(&sk->sk_async_wait_queue, skb);
2203}
2204#else
2205static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2206{
2207	__skb_unlink(skb, &sk->sk_receive_queue);
2208	__kfree_skb(skb);
2209}
2210#endif
2211
2212static inline
2213struct net *sock_net(const struct sock *sk)
2214{
2215	return read_pnet(&sk->sk_net);
2216}
2217
2218static inline
2219void sock_net_set(struct sock *sk, struct net *net)
2220{
2221	write_pnet(&sk->sk_net, net);
2222}
2223
2224/*
2225 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
2226 * They should not hold a reference to a namespace in order to allow
2227 * to stop it.
2228 * Sockets after sk_change_net should be released using sk_release_kernel
2229 */
2230static inline void sk_change_net(struct sock *sk, struct net *net)
2231{
2232	struct net *current_net = sock_net(sk);
2233
2234	if (!net_eq(current_net, net)) {
2235		put_net(current_net);
2236		sock_net_set(sk, hold_net(net));
2237	}
2238}
2239
2240static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2241{
2242	if (skb->sk) {
2243		struct sock *sk = skb->sk;
2244
2245		skb->destructor = NULL;
2246		skb->sk = NULL;
2247		return sk;
2248	}
2249	return NULL;
2250}
2251
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2252void sock_enable_timestamp(struct sock *sk, int flag);
2253int sock_get_timestamp(struct sock *, struct timeval __user *);
2254int sock_get_timestampns(struct sock *, struct timespec __user *);
2255int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2256		       int type);
2257
2258bool sk_ns_capable(const struct sock *sk,
2259		   struct user_namespace *user_ns, int cap);
2260bool sk_capable(const struct sock *sk, int cap);
2261bool sk_net_capable(const struct sock *sk, int cap);
2262
2263/*
2264 *	Enable debug/info messages
2265 */
2266extern int net_msg_warn;
2267#define NETDEBUG(fmt, args...) \
2268	do { if (net_msg_warn) printk(fmt,##args); } while (0)
2269
2270#define LIMIT_NETDEBUG(fmt, args...) \
2271	do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
 
 
 
 
 
 
 
2272
2273extern __u32 sysctl_wmem_max;
2274extern __u32 sysctl_rmem_max;
2275
 
2276extern int sysctl_optmem_max;
2277
2278extern __u32 sysctl_wmem_default;
2279extern __u32 sysctl_rmem_default;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2280
2281#endif	/* _SOCK_H */