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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
63#include <linux/atomic.h>
64#include <linux/refcount.h>
65#include <net/dst.h>
66#include <net/checksum.h>
67#include <net/tcp_states.h>
68#include <linux/net_tstamp.h>
69#include <net/smc.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_hash: hash value used with various protocol lookup tables
122 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
123 * @skc_dport: placeholder for inet_dport/tw_dport
124 * @skc_num: placeholder for inet_num/tw_num
125 * @skc_family: network address family
126 * @skc_state: Connection state
127 * @skc_reuse: %SO_REUSEADDR setting
128 * @skc_reuseport: %SO_REUSEPORT setting
129 * @skc_bound_dev_if: bound device index if != 0
130 * @skc_bind_node: bind hash linkage for various protocol lookup tables
131 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
132 * @skc_prot: protocol handlers inside a network family
133 * @skc_net: reference to the network namespace of this socket
134 * @skc_node: main hash linkage for various protocol lookup tables
135 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
136 * @skc_tx_queue_mapping: tx queue number for this connection
137 * @skc_rx_queue_mapping: rx queue number for this connection
138 * @skc_flags: place holder for sk_flags
139 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
140 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
141 * @skc_incoming_cpu: record/match cpu processing incoming packets
142 * @skc_refcnt: reference count
143 *
144 * This is the minimal network layer representation of sockets, the header
145 * for struct sock and struct inet_timewait_sock.
146 */
147struct sock_common {
148 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
149 * address on 64bit arches : cf INET_MATCH()
150 */
151 union {
152 __addrpair skc_addrpair;
153 struct {
154 __be32 skc_daddr;
155 __be32 skc_rcv_saddr;
156 };
157 };
158 union {
159 unsigned int skc_hash;
160 __u16 skc_u16hashes[2];
161 };
162 /* skc_dport && skc_num must be grouped as well */
163 union {
164 __portpair skc_portpair;
165 struct {
166 __be16 skc_dport;
167 __u16 skc_num;
168 };
169 };
170
171 unsigned short skc_family;
172 volatile unsigned char skc_state;
173 unsigned char skc_reuse:4;
174 unsigned char skc_reuseport:1;
175 unsigned char skc_ipv6only:1;
176 unsigned char skc_net_refcnt:1;
177 int skc_bound_dev_if;
178 union {
179 struct hlist_node skc_bind_node;
180 struct hlist_node skc_portaddr_node;
181 };
182 struct proto *skc_prot;
183 possible_net_t skc_net;
184
185#if IS_ENABLED(CONFIG_IPV6)
186 struct in6_addr skc_v6_daddr;
187 struct in6_addr skc_v6_rcv_saddr;
188#endif
189
190 atomic64_t skc_cookie;
191
192 /* following fields are padding to force
193 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
194 * assuming IPV6 is enabled. We use this padding differently
195 * for different kind of 'sockets'
196 */
197 union {
198 unsigned long skc_flags;
199 struct sock *skc_listener; /* request_sock */
200 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
201 };
202 /*
203 * fields between dontcopy_begin/dontcopy_end
204 * are not copied in sock_copy()
205 */
206 /* private: */
207 int skc_dontcopy_begin[0];
208 /* public: */
209 union {
210 struct hlist_node skc_node;
211 struct hlist_nulls_node skc_nulls_node;
212 };
213 unsigned short skc_tx_queue_mapping;
214#ifdef CONFIG_XPS
215 unsigned short skc_rx_queue_mapping;
216#endif
217 union {
218 int skc_incoming_cpu;
219 u32 skc_rcv_wnd;
220 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */
221 };
222
223 refcount_t skc_refcnt;
224 /* private: */
225 int skc_dontcopy_end[0];
226 union {
227 u32 skc_rxhash;
228 u32 skc_window_clamp;
229 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */
230 };
231 /* public: */
232};
233
234struct bpf_sk_storage;
235
236/**
237 * struct sock - network layer representation of sockets
238 * @__sk_common: shared layout with inet_timewait_sock
239 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
240 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
241 * @sk_lock: synchronizer
242 * @sk_kern_sock: True if sock is using kernel lock classes
243 * @sk_rcvbuf: size of receive buffer in bytes
244 * @sk_wq: sock wait queue and async head
245 * @sk_rx_dst: receive input route used by early demux
246 * @sk_dst_cache: destination cache
247 * @sk_dst_pending_confirm: need to confirm neighbour
248 * @sk_policy: flow policy
249 * @sk_receive_queue: incoming packets
250 * @sk_wmem_alloc: transmit queue bytes committed
251 * @sk_tsq_flags: TCP Small Queues flags
252 * @sk_write_queue: Packet sending queue
253 * @sk_omem_alloc: "o" is "option" or "other"
254 * @sk_wmem_queued: persistent queue size
255 * @sk_forward_alloc: space allocated forward
256 * @sk_napi_id: id of the last napi context to receive data for sk
257 * @sk_ll_usec: usecs to busypoll when there is no data
258 * @sk_allocation: allocation mode
259 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
260 * @sk_pacing_status: Pacing status (requested, handled by sch_fq)
261 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
262 * @sk_sndbuf: size of send buffer in bytes
263 * @__sk_flags_offset: empty field used to determine location of bitfield
264 * @sk_padding: unused element for alignment
265 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
266 * @sk_no_check_rx: allow zero checksum in RX packets
267 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
268 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
269 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
270 * @sk_gso_max_size: Maximum GSO segment size to build
271 * @sk_gso_max_segs: Maximum number of GSO segments
272 * @sk_pacing_shift: scaling factor for TCP Small Queues
273 * @sk_lingertime: %SO_LINGER l_linger setting
274 * @sk_backlog: always used with the per-socket spinlock held
275 * @sk_callback_lock: used with the callbacks in the end of this struct
276 * @sk_error_queue: rarely used
277 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
278 * IPV6_ADDRFORM for instance)
279 * @sk_err: last error
280 * @sk_err_soft: errors that don't cause failure but are the cause of a
281 * persistent failure not just 'timed out'
282 * @sk_drops: raw/udp drops counter
283 * @sk_ack_backlog: current listen backlog
284 * @sk_max_ack_backlog: listen backlog set in listen()
285 * @sk_uid: user id of owner
286 * @sk_priority: %SO_PRIORITY setting
287 * @sk_type: socket type (%SOCK_STREAM, etc)
288 * @sk_protocol: which protocol this socket belongs in this network family
289 * @sk_peer_pid: &struct pid for this socket's peer
290 * @sk_peer_cred: %SO_PEERCRED setting
291 * @sk_rcvlowat: %SO_RCVLOWAT setting
292 * @sk_rcvtimeo: %SO_RCVTIMEO setting
293 * @sk_sndtimeo: %SO_SNDTIMEO setting
294 * @sk_txhash: computed flow hash for use on transmit
295 * @sk_filter: socket filtering instructions
296 * @sk_timer: sock cleanup timer
297 * @sk_stamp: time stamp of last packet received
298 * @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
299 * @sk_tsflags: SO_TIMESTAMPING socket options
300 * @sk_tskey: counter to disambiguate concurrent tstamp requests
301 * @sk_zckey: counter to order MSG_ZEROCOPY notifications
302 * @sk_socket: Identd and reporting IO signals
303 * @sk_user_data: RPC layer private data
304 * @sk_frag: cached page frag
305 * @sk_peek_off: current peek_offset value
306 * @sk_send_head: front of stuff to transmit
307 * @sk_security: used by security modules
308 * @sk_mark: generic packet mark
309 * @sk_cgrp_data: cgroup data for this cgroup
310 * @sk_memcg: this socket's memory cgroup association
311 * @sk_write_pending: a write to stream socket waits to start
312 * @sk_state_change: callback to indicate change in the state of the sock
313 * @sk_data_ready: callback to indicate there is data to be processed
314 * @sk_write_space: callback to indicate there is bf sending space available
315 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
316 * @sk_backlog_rcv: callback to process the backlog
317 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
318 * @sk_reuseport_cb: reuseport group container
319 * @sk_rcu: used during RCU grace period
320 * @sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
321 * @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
322 * @sk_txtime_unused: unused txtime flags
323 */
324struct sock {
325 /*
326 * Now struct inet_timewait_sock also uses sock_common, so please just
327 * don't add nothing before this first member (__sk_common) --acme
328 */
329 struct sock_common __sk_common;
330#define sk_node __sk_common.skc_node
331#define sk_nulls_node __sk_common.skc_nulls_node
332#define sk_refcnt __sk_common.skc_refcnt
333#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
334#ifdef CONFIG_XPS
335#define sk_rx_queue_mapping __sk_common.skc_rx_queue_mapping
336#endif
337
338#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
339#define sk_dontcopy_end __sk_common.skc_dontcopy_end
340#define sk_hash __sk_common.skc_hash
341#define sk_portpair __sk_common.skc_portpair
342#define sk_num __sk_common.skc_num
343#define sk_dport __sk_common.skc_dport
344#define sk_addrpair __sk_common.skc_addrpair
345#define sk_daddr __sk_common.skc_daddr
346#define sk_rcv_saddr __sk_common.skc_rcv_saddr
347#define sk_family __sk_common.skc_family
348#define sk_state __sk_common.skc_state
349#define sk_reuse __sk_common.skc_reuse
350#define sk_reuseport __sk_common.skc_reuseport
351#define sk_ipv6only __sk_common.skc_ipv6only
352#define sk_net_refcnt __sk_common.skc_net_refcnt
353#define sk_bound_dev_if __sk_common.skc_bound_dev_if
354#define sk_bind_node __sk_common.skc_bind_node
355#define sk_prot __sk_common.skc_prot
356#define sk_net __sk_common.skc_net
357#define sk_v6_daddr __sk_common.skc_v6_daddr
358#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
359#define sk_cookie __sk_common.skc_cookie
360#define sk_incoming_cpu __sk_common.skc_incoming_cpu
361#define sk_flags __sk_common.skc_flags
362#define sk_rxhash __sk_common.skc_rxhash
363
364 socket_lock_t sk_lock;
365 atomic_t sk_drops;
366 int sk_rcvlowat;
367 struct sk_buff_head sk_error_queue;
368 struct sk_buff *sk_rx_skb_cache;
369 struct sk_buff_head sk_receive_queue;
370 /*
371 * The backlog queue is special, it is always used with
372 * the per-socket spinlock held and requires low latency
373 * access. Therefore we special case it's implementation.
374 * Note : rmem_alloc is in this structure to fill a hole
375 * on 64bit arches, not because its logically part of
376 * backlog.
377 */
378 struct {
379 atomic_t rmem_alloc;
380 int len;
381 struct sk_buff *head;
382 struct sk_buff *tail;
383 } sk_backlog;
384#define sk_rmem_alloc sk_backlog.rmem_alloc
385
386 int sk_forward_alloc;
387#ifdef CONFIG_NET_RX_BUSY_POLL
388 unsigned int sk_ll_usec;
389 /* ===== mostly read cache line ===== */
390 unsigned int sk_napi_id;
391#endif
392 int sk_rcvbuf;
393
394 struct sk_filter __rcu *sk_filter;
395 union {
396 struct socket_wq __rcu *sk_wq;
397 struct socket_wq *sk_wq_raw;
398 };
399#ifdef CONFIG_XFRM
400 struct xfrm_policy __rcu *sk_policy[2];
401#endif
402 struct dst_entry *sk_rx_dst;
403 struct dst_entry __rcu *sk_dst_cache;
404 atomic_t sk_omem_alloc;
405 int sk_sndbuf;
406
407 /* ===== cache line for TX ===== */
408 int sk_wmem_queued;
409 refcount_t sk_wmem_alloc;
410 unsigned long sk_tsq_flags;
411 union {
412 struct sk_buff *sk_send_head;
413 struct rb_root tcp_rtx_queue;
414 };
415 struct sk_buff *sk_tx_skb_cache;
416 struct sk_buff_head sk_write_queue;
417 __s32 sk_peek_off;
418 int sk_write_pending;
419 __u32 sk_dst_pending_confirm;
420 u32 sk_pacing_status; /* see enum sk_pacing */
421 long sk_sndtimeo;
422 struct timer_list sk_timer;
423 __u32 sk_priority;
424 __u32 sk_mark;
425 unsigned long sk_pacing_rate; /* bytes per second */
426 unsigned long sk_max_pacing_rate;
427 struct page_frag sk_frag;
428 netdev_features_t sk_route_caps;
429 netdev_features_t sk_route_nocaps;
430 netdev_features_t sk_route_forced_caps;
431 int sk_gso_type;
432 unsigned int sk_gso_max_size;
433 gfp_t sk_allocation;
434 __u32 sk_txhash;
435
436 /*
437 * Because of non atomicity rules, all
438 * changes are protected by socket lock.
439 */
440 unsigned int __sk_flags_offset[0];
441#ifdef __BIG_ENDIAN_BITFIELD
442#define SK_FL_PROTO_SHIFT 16
443#define SK_FL_PROTO_MASK 0x00ff0000
444
445#define SK_FL_TYPE_SHIFT 0
446#define SK_FL_TYPE_MASK 0x0000ffff
447#else
448#define SK_FL_PROTO_SHIFT 8
449#define SK_FL_PROTO_MASK 0x0000ff00
450
451#define SK_FL_TYPE_SHIFT 16
452#define SK_FL_TYPE_MASK 0xffff0000
453#endif
454
455 unsigned int sk_padding : 1,
456 sk_kern_sock : 1,
457 sk_no_check_tx : 1,
458 sk_no_check_rx : 1,
459 sk_userlocks : 4,
460 sk_protocol : 8,
461 sk_type : 16;
462#define SK_PROTOCOL_MAX U8_MAX
463 u16 sk_gso_max_segs;
464 u8 sk_pacing_shift;
465 unsigned long sk_lingertime;
466 struct proto *sk_prot_creator;
467 rwlock_t sk_callback_lock;
468 int sk_err,
469 sk_err_soft;
470 u32 sk_ack_backlog;
471 u32 sk_max_ack_backlog;
472 kuid_t sk_uid;
473 struct pid *sk_peer_pid;
474 const struct cred *sk_peer_cred;
475 long sk_rcvtimeo;
476 ktime_t sk_stamp;
477#if BITS_PER_LONG==32
478 seqlock_t sk_stamp_seq;
479#endif
480 u16 sk_tsflags;
481 u8 sk_shutdown;
482 u32 sk_tskey;
483 atomic_t sk_zckey;
484
485 u8 sk_clockid;
486 u8 sk_txtime_deadline_mode : 1,
487 sk_txtime_report_errors : 1,
488 sk_txtime_unused : 6;
489
490 struct socket *sk_socket;
491 void *sk_user_data;
492#ifdef CONFIG_SECURITY
493 void *sk_security;
494#endif
495 struct sock_cgroup_data sk_cgrp_data;
496 struct mem_cgroup *sk_memcg;
497 void (*sk_state_change)(struct sock *sk);
498 void (*sk_data_ready)(struct sock *sk);
499 void (*sk_write_space)(struct sock *sk);
500 void (*sk_error_report)(struct sock *sk);
501 int (*sk_backlog_rcv)(struct sock *sk,
502 struct sk_buff *skb);
503#ifdef CONFIG_SOCK_VALIDATE_XMIT
504 struct sk_buff* (*sk_validate_xmit_skb)(struct sock *sk,
505 struct net_device *dev,
506 struct sk_buff *skb);
507#endif
508 void (*sk_destruct)(struct sock *sk);
509 struct sock_reuseport __rcu *sk_reuseport_cb;
510#ifdef CONFIG_BPF_SYSCALL
511 struct bpf_sk_storage __rcu *sk_bpf_storage;
512#endif
513 struct rcu_head sk_rcu;
514};
515
516enum sk_pacing {
517 SK_PACING_NONE = 0,
518 SK_PACING_NEEDED = 1,
519 SK_PACING_FQ = 2,
520};
521
522#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
523
524#define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk)))
525#define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr)
526
527/*
528 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
529 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
530 * on a socket means that the socket will reuse everybody else's port
531 * without looking at the other's sk_reuse value.
532 */
533
534#define SK_NO_REUSE 0
535#define SK_CAN_REUSE 1
536#define SK_FORCE_REUSE 2
537
538int sk_set_peek_off(struct sock *sk, int val);
539
540static inline int sk_peek_offset(struct sock *sk, int flags)
541{
542 if (unlikely(flags & MSG_PEEK)) {
543 return READ_ONCE(sk->sk_peek_off);
544 }
545
546 return 0;
547}
548
549static inline void sk_peek_offset_bwd(struct sock *sk, int val)
550{
551 s32 off = READ_ONCE(sk->sk_peek_off);
552
553 if (unlikely(off >= 0)) {
554 off = max_t(s32, off - val, 0);
555 WRITE_ONCE(sk->sk_peek_off, off);
556 }
557}
558
559static inline void sk_peek_offset_fwd(struct sock *sk, int val)
560{
561 sk_peek_offset_bwd(sk, -val);
562}
563
564/*
565 * Hashed lists helper routines
566 */
567static inline struct sock *sk_entry(const struct hlist_node *node)
568{
569 return hlist_entry(node, struct sock, sk_node);
570}
571
572static inline struct sock *__sk_head(const struct hlist_head *head)
573{
574 return hlist_entry(head->first, struct sock, sk_node);
575}
576
577static inline struct sock *sk_head(const struct hlist_head *head)
578{
579 return hlist_empty(head) ? NULL : __sk_head(head);
580}
581
582static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
583{
584 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
585}
586
587static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
588{
589 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
590}
591
592static inline struct sock *sk_next(const struct sock *sk)
593{
594 return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
595}
596
597static inline struct sock *sk_nulls_next(const struct sock *sk)
598{
599 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
600 hlist_nulls_entry(sk->sk_nulls_node.next,
601 struct sock, sk_nulls_node) :
602 NULL;
603}
604
605static inline bool sk_unhashed(const struct sock *sk)
606{
607 return hlist_unhashed(&sk->sk_node);
608}
609
610static inline bool sk_hashed(const struct sock *sk)
611{
612 return !sk_unhashed(sk);
613}
614
615static inline void sk_node_init(struct hlist_node *node)
616{
617 node->pprev = NULL;
618}
619
620static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
621{
622 node->pprev = NULL;
623}
624
625static inline void __sk_del_node(struct sock *sk)
626{
627 __hlist_del(&sk->sk_node);
628}
629
630/* NB: equivalent to hlist_del_init_rcu */
631static inline bool __sk_del_node_init(struct sock *sk)
632{
633 if (sk_hashed(sk)) {
634 __sk_del_node(sk);
635 sk_node_init(&sk->sk_node);
636 return true;
637 }
638 return false;
639}
640
641/* Grab socket reference count. This operation is valid only
642 when sk is ALREADY grabbed f.e. it is found in hash table
643 or a list and the lookup is made under lock preventing hash table
644 modifications.
645 */
646
647static __always_inline void sock_hold(struct sock *sk)
648{
649 refcount_inc(&sk->sk_refcnt);
650}
651
652/* Ungrab socket in the context, which assumes that socket refcnt
653 cannot hit zero, f.e. it is true in context of any socketcall.
654 */
655static __always_inline void __sock_put(struct sock *sk)
656{
657 refcount_dec(&sk->sk_refcnt);
658}
659
660static inline bool sk_del_node_init(struct sock *sk)
661{
662 bool rc = __sk_del_node_init(sk);
663
664 if (rc) {
665 /* paranoid for a while -acme */
666 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
667 __sock_put(sk);
668 }
669 return rc;
670}
671#define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
672
673static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
674{
675 if (sk_hashed(sk)) {
676 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
677 return true;
678 }
679 return false;
680}
681
682static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
683{
684 bool rc = __sk_nulls_del_node_init_rcu(sk);
685
686 if (rc) {
687 /* paranoid for a while -acme */
688 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
689 __sock_put(sk);
690 }
691 return rc;
692}
693
694static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
695{
696 hlist_add_head(&sk->sk_node, list);
697}
698
699static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
700{
701 sock_hold(sk);
702 __sk_add_node(sk, list);
703}
704
705static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
706{
707 sock_hold(sk);
708 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
709 sk->sk_family == AF_INET6)
710 hlist_add_tail_rcu(&sk->sk_node, list);
711 else
712 hlist_add_head_rcu(&sk->sk_node, list);
713}
714
715static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
716{
717 sock_hold(sk);
718 hlist_add_tail_rcu(&sk->sk_node, list);
719}
720
721static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
722{
723 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
724}
725
726static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
727{
728 sock_hold(sk);
729 __sk_nulls_add_node_rcu(sk, list);
730}
731
732static inline void __sk_del_bind_node(struct sock *sk)
733{
734 __hlist_del(&sk->sk_bind_node);
735}
736
737static inline void sk_add_bind_node(struct sock *sk,
738 struct hlist_head *list)
739{
740 hlist_add_head(&sk->sk_bind_node, list);
741}
742
743#define sk_for_each(__sk, list) \
744 hlist_for_each_entry(__sk, list, sk_node)
745#define sk_for_each_rcu(__sk, list) \
746 hlist_for_each_entry_rcu(__sk, list, sk_node)
747#define sk_nulls_for_each(__sk, node, list) \
748 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
749#define sk_nulls_for_each_rcu(__sk, node, list) \
750 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
751#define sk_for_each_from(__sk) \
752 hlist_for_each_entry_from(__sk, sk_node)
753#define sk_nulls_for_each_from(__sk, node) \
754 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
755 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
756#define sk_for_each_safe(__sk, tmp, list) \
757 hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
758#define sk_for_each_bound(__sk, list) \
759 hlist_for_each_entry(__sk, list, sk_bind_node)
760
761/**
762 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
763 * @tpos: the type * to use as a loop cursor.
764 * @pos: the &struct hlist_node to use as a loop cursor.
765 * @head: the head for your list.
766 * @offset: offset of hlist_node within the struct.
767 *
768 */
769#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \
770 for (pos = rcu_dereference(hlist_first_rcu(head)); \
771 pos != NULL && \
772 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \
773 pos = rcu_dereference(hlist_next_rcu(pos)))
774
775static inline struct user_namespace *sk_user_ns(struct sock *sk)
776{
777 /* Careful only use this in a context where these parameters
778 * can not change and must all be valid, such as recvmsg from
779 * userspace.
780 */
781 return sk->sk_socket->file->f_cred->user_ns;
782}
783
784/* Sock flags */
785enum sock_flags {
786 SOCK_DEAD,
787 SOCK_DONE,
788 SOCK_URGINLINE,
789 SOCK_KEEPOPEN,
790 SOCK_LINGER,
791 SOCK_DESTROY,
792 SOCK_BROADCAST,
793 SOCK_TIMESTAMP,
794 SOCK_ZAPPED,
795 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
796 SOCK_DBG, /* %SO_DEBUG setting */
797 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
798 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
799 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
800 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
801 SOCK_MEMALLOC, /* VM depends on this socket for swapping */
802 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
803 SOCK_FASYNC, /* fasync() active */
804 SOCK_RXQ_OVFL,
805 SOCK_ZEROCOPY, /* buffers from userspace */
806 SOCK_WIFI_STATUS, /* push wifi status to userspace */
807 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
808 * Will use last 4 bytes of packet sent from
809 * user-space instead.
810 */
811 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
812 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
813 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
814 SOCK_TXTIME,
815 SOCK_XDP, /* XDP is attached */
816 SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
817};
818
819#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
820
821static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
822{
823 nsk->sk_flags = osk->sk_flags;
824}
825
826static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
827{
828 __set_bit(flag, &sk->sk_flags);
829}
830
831static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
832{
833 __clear_bit(flag, &sk->sk_flags);
834}
835
836static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
837{
838 return test_bit(flag, &sk->sk_flags);
839}
840
841#ifdef CONFIG_NET
842DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
843static inline int sk_memalloc_socks(void)
844{
845 return static_branch_unlikely(&memalloc_socks_key);
846}
847#else
848
849static inline int sk_memalloc_socks(void)
850{
851 return 0;
852}
853
854#endif
855
856static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
857{
858 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
859}
860
861static inline void sk_acceptq_removed(struct sock *sk)
862{
863 sk->sk_ack_backlog--;
864}
865
866static inline void sk_acceptq_added(struct sock *sk)
867{
868 sk->sk_ack_backlog++;
869}
870
871static inline bool sk_acceptq_is_full(const struct sock *sk)
872{
873 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
874}
875
876/*
877 * Compute minimal free write space needed to queue new packets.
878 */
879static inline int sk_stream_min_wspace(const struct sock *sk)
880{
881 return READ_ONCE(sk->sk_wmem_queued) >> 1;
882}
883
884static inline int sk_stream_wspace(const struct sock *sk)
885{
886 return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
887}
888
889static inline void sk_wmem_queued_add(struct sock *sk, int val)
890{
891 WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
892}
893
894void sk_stream_write_space(struct sock *sk);
895
896/* OOB backlog add */
897static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
898{
899 /* dont let skb dst not refcounted, we are going to leave rcu lock */
900 skb_dst_force(skb);
901
902 if (!sk->sk_backlog.tail)
903 sk->sk_backlog.head = skb;
904 else
905 sk->sk_backlog.tail->next = skb;
906
907 sk->sk_backlog.tail = skb;
908 skb->next = NULL;
909}
910
911/*
912 * Take into account size of receive queue and backlog queue
913 * Do not take into account this skb truesize,
914 * to allow even a single big packet to come.
915 */
916static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
917{
918 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
919
920 return qsize > limit;
921}
922
923/* The per-socket spinlock must be held here. */
924static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
925 unsigned int limit)
926{
927 if (sk_rcvqueues_full(sk, limit))
928 return -ENOBUFS;
929
930 /*
931 * If the skb was allocated from pfmemalloc reserves, only
932 * allow SOCK_MEMALLOC sockets to use it as this socket is
933 * helping free memory
934 */
935 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
936 return -ENOMEM;
937
938 __sk_add_backlog(sk, skb);
939 sk->sk_backlog.len += skb->truesize;
940 return 0;
941}
942
943int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
944
945static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
946{
947 if (sk_memalloc_socks() && skb_pfmemalloc(skb))
948 return __sk_backlog_rcv(sk, skb);
949
950 return sk->sk_backlog_rcv(sk, skb);
951}
952
953static inline void sk_incoming_cpu_update(struct sock *sk)
954{
955 int cpu = raw_smp_processor_id();
956
957 if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
958 WRITE_ONCE(sk->sk_incoming_cpu, cpu);
959}
960
961static inline void sock_rps_record_flow_hash(__u32 hash)
962{
963#ifdef CONFIG_RPS
964 struct rps_sock_flow_table *sock_flow_table;
965
966 rcu_read_lock();
967 sock_flow_table = rcu_dereference(rps_sock_flow_table);
968 rps_record_sock_flow(sock_flow_table, hash);
969 rcu_read_unlock();
970#endif
971}
972
973static inline void sock_rps_record_flow(const struct sock *sk)
974{
975#ifdef CONFIG_RPS
976 if (static_branch_unlikely(&rfs_needed)) {
977 /* Reading sk->sk_rxhash might incur an expensive cache line
978 * miss.
979 *
980 * TCP_ESTABLISHED does cover almost all states where RFS
981 * might be useful, and is cheaper [1] than testing :
982 * IPv4: inet_sk(sk)->inet_daddr
983 * IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
984 * OR an additional socket flag
985 * [1] : sk_state and sk_prot are in the same cache line.
986 */
987 if (sk->sk_state == TCP_ESTABLISHED)
988 sock_rps_record_flow_hash(sk->sk_rxhash);
989 }
990#endif
991}
992
993static inline void sock_rps_save_rxhash(struct sock *sk,
994 const struct sk_buff *skb)
995{
996#ifdef CONFIG_RPS
997 if (unlikely(sk->sk_rxhash != skb->hash))
998 sk->sk_rxhash = skb->hash;
999#endif
1000}
1001
1002static inline void sock_rps_reset_rxhash(struct sock *sk)
1003{
1004#ifdef CONFIG_RPS
1005 sk->sk_rxhash = 0;
1006#endif
1007}
1008
1009#define sk_wait_event(__sk, __timeo, __condition, __wait) \
1010 ({ int __rc; \
1011 release_sock(__sk); \
1012 __rc = __condition; \
1013 if (!__rc) { \
1014 *(__timeo) = wait_woken(__wait, \
1015 TASK_INTERRUPTIBLE, \
1016 *(__timeo)); \
1017 } \
1018 sched_annotate_sleep(); \
1019 lock_sock(__sk); \
1020 __rc = __condition; \
1021 __rc; \
1022 })
1023
1024int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1025int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1026void sk_stream_wait_close(struct sock *sk, long timeo_p);
1027int sk_stream_error(struct sock *sk, int flags, int err);
1028void sk_stream_kill_queues(struct sock *sk);
1029void sk_set_memalloc(struct sock *sk);
1030void sk_clear_memalloc(struct sock *sk);
1031
1032void __sk_flush_backlog(struct sock *sk);
1033
1034static inline bool sk_flush_backlog(struct sock *sk)
1035{
1036 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1037 __sk_flush_backlog(sk);
1038 return true;
1039 }
1040 return false;
1041}
1042
1043int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1044
1045struct request_sock_ops;
1046struct timewait_sock_ops;
1047struct inet_hashinfo;
1048struct raw_hashinfo;
1049struct smc_hashinfo;
1050struct module;
1051
1052/*
1053 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1054 * un-modified. Special care is taken when initializing object to zero.
1055 */
1056static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1057{
1058 if (offsetof(struct sock, sk_node.next) != 0)
1059 memset(sk, 0, offsetof(struct sock, sk_node.next));
1060 memset(&sk->sk_node.pprev, 0,
1061 size - offsetof(struct sock, sk_node.pprev));
1062}
1063
1064/* Networking protocol blocks we attach to sockets.
1065 * socket layer -> transport layer interface
1066 */
1067struct proto {
1068 void (*close)(struct sock *sk,
1069 long timeout);
1070 int (*pre_connect)(struct sock *sk,
1071 struct sockaddr *uaddr,
1072 int addr_len);
1073 int (*connect)(struct sock *sk,
1074 struct sockaddr *uaddr,
1075 int addr_len);
1076 int (*disconnect)(struct sock *sk, int flags);
1077
1078 struct sock * (*accept)(struct sock *sk, int flags, int *err,
1079 bool kern);
1080
1081 int (*ioctl)(struct sock *sk, int cmd,
1082 unsigned long arg);
1083 int (*init)(struct sock *sk);
1084 void (*destroy)(struct sock *sk);
1085 void (*shutdown)(struct sock *sk, int how);
1086 int (*setsockopt)(struct sock *sk, int level,
1087 int optname, char __user *optval,
1088 unsigned int optlen);
1089 int (*getsockopt)(struct sock *sk, int level,
1090 int optname, char __user *optval,
1091 int __user *option);
1092 void (*keepalive)(struct sock *sk, int valbool);
1093#ifdef CONFIG_COMPAT
1094 int (*compat_setsockopt)(struct sock *sk,
1095 int level,
1096 int optname, char __user *optval,
1097 unsigned int optlen);
1098 int (*compat_getsockopt)(struct sock *sk,
1099 int level,
1100 int optname, char __user *optval,
1101 int __user *option);
1102 int (*compat_ioctl)(struct sock *sk,
1103 unsigned int cmd, unsigned long arg);
1104#endif
1105 int (*sendmsg)(struct sock *sk, struct msghdr *msg,
1106 size_t len);
1107 int (*recvmsg)(struct sock *sk, struct msghdr *msg,
1108 size_t len, int noblock, int flags,
1109 int *addr_len);
1110 int (*sendpage)(struct sock *sk, struct page *page,
1111 int offset, size_t size, int flags);
1112 int (*bind)(struct sock *sk,
1113 struct sockaddr *uaddr, int addr_len);
1114
1115 int (*backlog_rcv) (struct sock *sk,
1116 struct sk_buff *skb);
1117
1118 void (*release_cb)(struct sock *sk);
1119
1120 /* Keeping track of sk's, looking them up, and port selection methods. */
1121 int (*hash)(struct sock *sk);
1122 void (*unhash)(struct sock *sk);
1123 void (*rehash)(struct sock *sk);
1124 int (*get_port)(struct sock *sk, unsigned short snum);
1125
1126 /* Keeping track of sockets in use */
1127#ifdef CONFIG_PROC_FS
1128 unsigned int inuse_idx;
1129#endif
1130
1131 bool (*stream_memory_free)(const struct sock *sk, int wake);
1132 bool (*stream_memory_read)(const struct sock *sk);
1133 /* Memory pressure */
1134 void (*enter_memory_pressure)(struct sock *sk);
1135 void (*leave_memory_pressure)(struct sock *sk);
1136 atomic_long_t *memory_allocated; /* Current allocated memory. */
1137 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
1138 /*
1139 * Pressure flag: try to collapse.
1140 * Technical note: it is used by multiple contexts non atomically.
1141 * All the __sk_mem_schedule() is of this nature: accounting
1142 * is strict, actions are advisory and have some latency.
1143 */
1144 unsigned long *memory_pressure;
1145 long *sysctl_mem;
1146
1147 int *sysctl_wmem;
1148 int *sysctl_rmem;
1149 u32 sysctl_wmem_offset;
1150 u32 sysctl_rmem_offset;
1151
1152 int max_header;
1153 bool no_autobind;
1154
1155 struct kmem_cache *slab;
1156 unsigned int obj_size;
1157 slab_flags_t slab_flags;
1158 unsigned int useroffset; /* Usercopy region offset */
1159 unsigned int usersize; /* Usercopy region size */
1160
1161 struct percpu_counter *orphan_count;
1162
1163 struct request_sock_ops *rsk_prot;
1164 struct timewait_sock_ops *twsk_prot;
1165
1166 union {
1167 struct inet_hashinfo *hashinfo;
1168 struct udp_table *udp_table;
1169 struct raw_hashinfo *raw_hash;
1170 struct smc_hashinfo *smc_hash;
1171 } h;
1172
1173 struct module *owner;
1174
1175 char name[32];
1176
1177 struct list_head node;
1178#ifdef SOCK_REFCNT_DEBUG
1179 atomic_t socks;
1180#endif
1181 int (*diag_destroy)(struct sock *sk, int err);
1182} __randomize_layout;
1183
1184int proto_register(struct proto *prot, int alloc_slab);
1185void proto_unregister(struct proto *prot);
1186int sock_load_diag_module(int family, int protocol);
1187
1188#ifdef SOCK_REFCNT_DEBUG
1189static inline void sk_refcnt_debug_inc(struct sock *sk)
1190{
1191 atomic_inc(&sk->sk_prot->socks);
1192}
1193
1194static inline void sk_refcnt_debug_dec(struct sock *sk)
1195{
1196 atomic_dec(&sk->sk_prot->socks);
1197 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1198 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1199}
1200
1201static inline void sk_refcnt_debug_release(const struct sock *sk)
1202{
1203 if (refcount_read(&sk->sk_refcnt) != 1)
1204 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1205 sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1206}
1207#else /* SOCK_REFCNT_DEBUG */
1208#define sk_refcnt_debug_inc(sk) do { } while (0)
1209#define sk_refcnt_debug_dec(sk) do { } while (0)
1210#define sk_refcnt_debug_release(sk) do { } while (0)
1211#endif /* SOCK_REFCNT_DEBUG */
1212
1213static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1214{
1215 if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1216 return false;
1217
1218 return sk->sk_prot->stream_memory_free ?
1219 sk->sk_prot->stream_memory_free(sk, wake) : true;
1220}
1221
1222static inline bool sk_stream_memory_free(const struct sock *sk)
1223{
1224 return __sk_stream_memory_free(sk, 0);
1225}
1226
1227static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1228{
1229 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1230 __sk_stream_memory_free(sk, wake);
1231}
1232
1233static inline bool sk_stream_is_writeable(const struct sock *sk)
1234{
1235 return __sk_stream_is_writeable(sk, 0);
1236}
1237
1238static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1239 struct cgroup *ancestor)
1240{
1241#ifdef CONFIG_SOCK_CGROUP_DATA
1242 return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1243 ancestor);
1244#else
1245 return -ENOTSUPP;
1246#endif
1247}
1248
1249static inline bool sk_has_memory_pressure(const struct sock *sk)
1250{
1251 return sk->sk_prot->memory_pressure != NULL;
1252}
1253
1254static inline bool sk_under_memory_pressure(const struct sock *sk)
1255{
1256 if (!sk->sk_prot->memory_pressure)
1257 return false;
1258
1259 if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1260 mem_cgroup_under_socket_pressure(sk->sk_memcg))
1261 return true;
1262
1263 return !!*sk->sk_prot->memory_pressure;
1264}
1265
1266static inline long
1267sk_memory_allocated(const struct sock *sk)
1268{
1269 return atomic_long_read(sk->sk_prot->memory_allocated);
1270}
1271
1272static inline long
1273sk_memory_allocated_add(struct sock *sk, int amt)
1274{
1275 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1276}
1277
1278static inline void
1279sk_memory_allocated_sub(struct sock *sk, int amt)
1280{
1281 atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1282}
1283
1284static inline void sk_sockets_allocated_dec(struct sock *sk)
1285{
1286 percpu_counter_dec(sk->sk_prot->sockets_allocated);
1287}
1288
1289static inline void sk_sockets_allocated_inc(struct sock *sk)
1290{
1291 percpu_counter_inc(sk->sk_prot->sockets_allocated);
1292}
1293
1294static inline u64
1295sk_sockets_allocated_read_positive(struct sock *sk)
1296{
1297 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1298}
1299
1300static inline int
1301proto_sockets_allocated_sum_positive(struct proto *prot)
1302{
1303 return percpu_counter_sum_positive(prot->sockets_allocated);
1304}
1305
1306static inline long
1307proto_memory_allocated(struct proto *prot)
1308{
1309 return atomic_long_read(prot->memory_allocated);
1310}
1311
1312static inline bool
1313proto_memory_pressure(struct proto *prot)
1314{
1315 if (!prot->memory_pressure)
1316 return false;
1317 return !!*prot->memory_pressure;
1318}
1319
1320
1321#ifdef CONFIG_PROC_FS
1322/* Called with local bh disabled */
1323void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1324int sock_prot_inuse_get(struct net *net, struct proto *proto);
1325int sock_inuse_get(struct net *net);
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 int __sk_prot_rehash(struct sock *sk)
1338{
1339 sk->sk_prot->unhash(sk);
1340 return sk->sk_prot->hash(sk);
1341}
1342
1343/* About 10 seconds */
1344#define SOCK_DESTROY_TIME (10*HZ)
1345
1346/* Sockets 0-1023 can't be bound to unless you are superuser */
1347#define PROT_SOCK 1024
1348
1349#define SHUTDOWN_MASK 3
1350#define RCV_SHUTDOWN 1
1351#define SEND_SHUTDOWN 2
1352
1353#define SOCK_SNDBUF_LOCK 1
1354#define SOCK_RCVBUF_LOCK 2
1355#define SOCK_BINDADDR_LOCK 4
1356#define SOCK_BINDPORT_LOCK 8
1357
1358struct socket_alloc {
1359 struct socket socket;
1360 struct inode vfs_inode;
1361};
1362
1363static inline struct socket *SOCKET_I(struct inode *inode)
1364{
1365 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1366}
1367
1368static inline struct inode *SOCK_INODE(struct socket *socket)
1369{
1370 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1371}
1372
1373/*
1374 * Functions for memory accounting
1375 */
1376int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1377int __sk_mem_schedule(struct sock *sk, int size, int kind);
1378void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1379void __sk_mem_reclaim(struct sock *sk, int amount);
1380
1381/* We used to have PAGE_SIZE here, but systems with 64KB pages
1382 * do not necessarily have 16x time more memory than 4KB ones.
1383 */
1384#define SK_MEM_QUANTUM 4096
1385#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1386#define SK_MEM_SEND 0
1387#define SK_MEM_RECV 1
1388
1389/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1390static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1391{
1392 long val = sk->sk_prot->sysctl_mem[index];
1393
1394#if PAGE_SIZE > SK_MEM_QUANTUM
1395 val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1396#elif PAGE_SIZE < SK_MEM_QUANTUM
1397 val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1398#endif
1399 return val;
1400}
1401
1402static inline int sk_mem_pages(int amt)
1403{
1404 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1405}
1406
1407static inline bool sk_has_account(struct sock *sk)
1408{
1409 /* return true if protocol supports memory accounting */
1410 return !!sk->sk_prot->memory_allocated;
1411}
1412
1413static inline bool sk_wmem_schedule(struct sock *sk, int size)
1414{
1415 if (!sk_has_account(sk))
1416 return true;
1417 return size <= sk->sk_forward_alloc ||
1418 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1419}
1420
1421static inline bool
1422sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1423{
1424 if (!sk_has_account(sk))
1425 return true;
1426 return size<= sk->sk_forward_alloc ||
1427 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1428 skb_pfmemalloc(skb);
1429}
1430
1431static inline void sk_mem_reclaim(struct sock *sk)
1432{
1433 if (!sk_has_account(sk))
1434 return;
1435 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1436 __sk_mem_reclaim(sk, sk->sk_forward_alloc);
1437}
1438
1439static inline void sk_mem_reclaim_partial(struct sock *sk)
1440{
1441 if (!sk_has_account(sk))
1442 return;
1443 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1444 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1445}
1446
1447static inline void sk_mem_charge(struct sock *sk, int size)
1448{
1449 if (!sk_has_account(sk))
1450 return;
1451 sk->sk_forward_alloc -= size;
1452}
1453
1454static inline void sk_mem_uncharge(struct sock *sk, int size)
1455{
1456 if (!sk_has_account(sk))
1457 return;
1458 sk->sk_forward_alloc += size;
1459
1460 /* Avoid a possible overflow.
1461 * TCP send queues can make this happen, if sk_mem_reclaim()
1462 * is not called and more than 2 GBytes are released at once.
1463 *
1464 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1465 * no need to hold that much forward allocation anyway.
1466 */
1467 if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1468 __sk_mem_reclaim(sk, 1 << 20);
1469}
1470
1471DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
1472static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1473{
1474 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1475 sk_wmem_queued_add(sk, -skb->truesize);
1476 sk_mem_uncharge(sk, skb->truesize);
1477 if (static_branch_unlikely(&tcp_tx_skb_cache_key) &&
1478 !sk->sk_tx_skb_cache && !skb_cloned(skb)) {
1479 skb_zcopy_clear(skb, true);
1480 sk->sk_tx_skb_cache = skb;
1481 return;
1482 }
1483 __kfree_skb(skb);
1484}
1485
1486static inline void sock_release_ownership(struct sock *sk)
1487{
1488 if (sk->sk_lock.owned) {
1489 sk->sk_lock.owned = 0;
1490
1491 /* The sk_lock has mutex_unlock() semantics: */
1492 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1493 }
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
1515#ifdef CONFIG_LOCKDEP
1516static inline bool lockdep_sock_is_held(const struct sock *sk)
1517{
1518 return lockdep_is_held(&sk->sk_lock) ||
1519 lockdep_is_held(&sk->sk_lock.slock);
1520}
1521#endif
1522
1523void lock_sock_nested(struct sock *sk, int subclass);
1524
1525static inline void lock_sock(struct sock *sk)
1526{
1527 lock_sock_nested(sk, 0);
1528}
1529
1530void __release_sock(struct sock *sk);
1531void release_sock(struct sock *sk);
1532
1533/* BH context may only use the following locking interface. */
1534#define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1535#define bh_lock_sock_nested(__sk) \
1536 spin_lock_nested(&((__sk)->sk_lock.slock), \
1537 SINGLE_DEPTH_NESTING)
1538#define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1539
1540bool lock_sock_fast(struct sock *sk);
1541/**
1542 * unlock_sock_fast - complement of lock_sock_fast
1543 * @sk: socket
1544 * @slow: slow mode
1545 *
1546 * fast unlock socket for user context.
1547 * If slow mode is on, we call regular release_sock()
1548 */
1549static inline void unlock_sock_fast(struct sock *sk, bool slow)
1550{
1551 if (slow)
1552 release_sock(sk);
1553 else
1554 spin_unlock_bh(&sk->sk_lock.slock);
1555}
1556
1557/* Used by processes to "lock" a socket state, so that
1558 * interrupts and bottom half handlers won't change it
1559 * from under us. It essentially blocks any incoming
1560 * packets, so that we won't get any new data or any
1561 * packets that change the state of the socket.
1562 *
1563 * While locked, BH processing will add new packets to
1564 * the backlog queue. This queue is processed by the
1565 * owner of the socket lock right before it is released.
1566 *
1567 * Since ~2.3.5 it is also exclusive sleep lock serializing
1568 * accesses from user process context.
1569 */
1570
1571static inline void sock_owned_by_me(const struct sock *sk)
1572{
1573#ifdef CONFIG_LOCKDEP
1574 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1575#endif
1576}
1577
1578static inline bool sock_owned_by_user(const struct sock *sk)
1579{
1580 sock_owned_by_me(sk);
1581 return sk->sk_lock.owned;
1582}
1583
1584static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1585{
1586 return sk->sk_lock.owned;
1587}
1588
1589/* no reclassification while locks are held */
1590static inline bool sock_allow_reclassification(const struct sock *csk)
1591{
1592 struct sock *sk = (struct sock *)csk;
1593
1594 return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1595}
1596
1597struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1598 struct proto *prot, int kern);
1599void sk_free(struct sock *sk);
1600void sk_destruct(struct sock *sk);
1601struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1602void sk_free_unlock_clone(struct sock *sk);
1603
1604struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1605 gfp_t priority);
1606void __sock_wfree(struct sk_buff *skb);
1607void sock_wfree(struct sk_buff *skb);
1608struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1609 gfp_t priority);
1610void skb_orphan_partial(struct sk_buff *skb);
1611void sock_rfree(struct sk_buff *skb);
1612void sock_efree(struct sk_buff *skb);
1613#ifdef CONFIG_INET
1614void sock_edemux(struct sk_buff *skb);
1615#else
1616#define sock_edemux sock_efree
1617#endif
1618
1619int sock_setsockopt(struct socket *sock, int level, int op,
1620 char __user *optval, unsigned int optlen);
1621
1622int sock_getsockopt(struct socket *sock, int level, int op,
1623 char __user *optval, int __user *optlen);
1624int sock_gettstamp(struct socket *sock, void __user *userstamp,
1625 bool timeval, bool time32);
1626struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1627 int noblock, int *errcode);
1628struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1629 unsigned long data_len, int noblock,
1630 int *errcode, int max_page_order);
1631void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1632void sock_kfree_s(struct sock *sk, void *mem, int size);
1633void sock_kzfree_s(struct sock *sk, void *mem, int size);
1634void sk_send_sigurg(struct sock *sk);
1635
1636struct sockcm_cookie {
1637 u64 transmit_time;
1638 u32 mark;
1639 u16 tsflags;
1640};
1641
1642static inline void sockcm_init(struct sockcm_cookie *sockc,
1643 const struct sock *sk)
1644{
1645 *sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1646}
1647
1648int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1649 struct sockcm_cookie *sockc);
1650int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1651 struct sockcm_cookie *sockc);
1652
1653/*
1654 * Functions to fill in entries in struct proto_ops when a protocol
1655 * does not implement a particular function.
1656 */
1657int sock_no_bind(struct socket *, struct sockaddr *, int);
1658int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1659int sock_no_socketpair(struct socket *, struct socket *);
1660int sock_no_accept(struct socket *, struct socket *, int, bool);
1661int sock_no_getname(struct socket *, struct sockaddr *, int);
1662int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1663int sock_no_listen(struct socket *, int);
1664int sock_no_shutdown(struct socket *, int);
1665int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1666int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1667int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1668int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1669int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1670int sock_no_mmap(struct file *file, struct socket *sock,
1671 struct vm_area_struct *vma);
1672ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1673 size_t size, int flags);
1674ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1675 int offset, size_t size, int flags);
1676
1677/*
1678 * Functions to fill in entries in struct proto_ops when a protocol
1679 * uses the inet style.
1680 */
1681int sock_common_getsockopt(struct socket *sock, int level, int optname,
1682 char __user *optval, int __user *optlen);
1683int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1684 int flags);
1685int sock_common_setsockopt(struct socket *sock, int level, int optname,
1686 char __user *optval, unsigned int optlen);
1687int compat_sock_common_getsockopt(struct socket *sock, int level,
1688 int optname, char __user *optval, int __user *optlen);
1689int compat_sock_common_setsockopt(struct socket *sock, int level,
1690 int optname, char __user *optval, unsigned int optlen);
1691
1692void sk_common_release(struct sock *sk);
1693
1694/*
1695 * Default socket callbacks and setup code
1696 */
1697
1698/* Initialise core socket variables */
1699void sock_init_data(struct socket *sock, struct sock *sk);
1700
1701/*
1702 * Socket reference counting postulates.
1703 *
1704 * * Each user of socket SHOULD hold a reference count.
1705 * * Each access point to socket (an hash table bucket, reference from a list,
1706 * running timer, skb in flight MUST hold a reference count.
1707 * * When reference count hits 0, it means it will never increase back.
1708 * * When reference count hits 0, it means that no references from
1709 * outside exist to this socket and current process on current CPU
1710 * is last user and may/should destroy this socket.
1711 * * sk_free is called from any context: process, BH, IRQ. When
1712 * it is called, socket has no references from outside -> sk_free
1713 * may release descendant resources allocated by the socket, but
1714 * to the time when it is called, socket is NOT referenced by any
1715 * hash tables, lists etc.
1716 * * Packets, delivered from outside (from network or from another process)
1717 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1718 * when they sit in queue. Otherwise, packets will leak to hole, when
1719 * socket is looked up by one cpu and unhasing is made by another CPU.
1720 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1721 * (leak to backlog). Packet socket does all the processing inside
1722 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1723 * use separate SMP lock, so that they are prone too.
1724 */
1725
1726/* Ungrab socket and destroy it, if it was the last reference. */
1727static inline void sock_put(struct sock *sk)
1728{
1729 if (refcount_dec_and_test(&sk->sk_refcnt))
1730 sk_free(sk);
1731}
1732/* Generic version of sock_put(), dealing with all sockets
1733 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1734 */
1735void sock_gen_put(struct sock *sk);
1736
1737int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1738 unsigned int trim_cap, bool refcounted);
1739static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1740 const int nested)
1741{
1742 return __sk_receive_skb(sk, skb, nested, 1, true);
1743}
1744
1745static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1746{
1747 /* sk_tx_queue_mapping accept only upto a 16-bit value */
1748 if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1749 return;
1750 sk->sk_tx_queue_mapping = tx_queue;
1751}
1752
1753#define NO_QUEUE_MAPPING USHRT_MAX
1754
1755static inline void sk_tx_queue_clear(struct sock *sk)
1756{
1757 sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1758}
1759
1760static inline int sk_tx_queue_get(const struct sock *sk)
1761{
1762 if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1763 return sk->sk_tx_queue_mapping;
1764
1765 return -1;
1766}
1767
1768static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
1769{
1770#ifdef CONFIG_XPS
1771 if (skb_rx_queue_recorded(skb)) {
1772 u16 rx_queue = skb_get_rx_queue(skb);
1773
1774 if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1775 return;
1776
1777 sk->sk_rx_queue_mapping = rx_queue;
1778 }
1779#endif
1780}
1781
1782static inline void sk_rx_queue_clear(struct sock *sk)
1783{
1784#ifdef CONFIG_XPS
1785 sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1786#endif
1787}
1788
1789#ifdef CONFIG_XPS
1790static inline int sk_rx_queue_get(const struct sock *sk)
1791{
1792 if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1793 return sk->sk_rx_queue_mapping;
1794
1795 return -1;
1796}
1797#endif
1798
1799static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1800{
1801 sk_tx_queue_clear(sk);
1802 sk->sk_socket = sock;
1803}
1804
1805static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1806{
1807 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1808 return &rcu_dereference_raw(sk->sk_wq)->wait;
1809}
1810/* Detach socket from process context.
1811 * Announce socket dead, detach it from wait queue and inode.
1812 * Note that parent inode held reference count on this struct sock,
1813 * we do not release it in this function, because protocol
1814 * probably wants some additional cleanups or even continuing
1815 * to work with this socket (TCP).
1816 */
1817static inline void sock_orphan(struct sock *sk)
1818{
1819 write_lock_bh(&sk->sk_callback_lock);
1820 sock_set_flag(sk, SOCK_DEAD);
1821 sk_set_socket(sk, NULL);
1822 sk->sk_wq = NULL;
1823 write_unlock_bh(&sk->sk_callback_lock);
1824}
1825
1826static inline void sock_graft(struct sock *sk, struct socket *parent)
1827{
1828 WARN_ON(parent->sk);
1829 write_lock_bh(&sk->sk_callback_lock);
1830 rcu_assign_pointer(sk->sk_wq, &parent->wq);
1831 parent->sk = sk;
1832 sk_set_socket(sk, parent);
1833 sk->sk_uid = SOCK_INODE(parent)->i_uid;
1834 security_sock_graft(sk, parent);
1835 write_unlock_bh(&sk->sk_callback_lock);
1836}
1837
1838kuid_t sock_i_uid(struct sock *sk);
1839unsigned long sock_i_ino(struct sock *sk);
1840
1841static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1842{
1843 return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1844}
1845
1846static inline u32 net_tx_rndhash(void)
1847{
1848 u32 v = prandom_u32();
1849
1850 return v ?: 1;
1851}
1852
1853static inline void sk_set_txhash(struct sock *sk)
1854{
1855 sk->sk_txhash = net_tx_rndhash();
1856}
1857
1858static inline void sk_rethink_txhash(struct sock *sk)
1859{
1860 if (sk->sk_txhash)
1861 sk_set_txhash(sk);
1862}
1863
1864static inline struct dst_entry *
1865__sk_dst_get(struct sock *sk)
1866{
1867 return rcu_dereference_check(sk->sk_dst_cache,
1868 lockdep_sock_is_held(sk));
1869}
1870
1871static inline struct dst_entry *
1872sk_dst_get(struct sock *sk)
1873{
1874 struct dst_entry *dst;
1875
1876 rcu_read_lock();
1877 dst = rcu_dereference(sk->sk_dst_cache);
1878 if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1879 dst = NULL;
1880 rcu_read_unlock();
1881 return dst;
1882}
1883
1884static inline void dst_negative_advice(struct sock *sk)
1885{
1886 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1887
1888 sk_rethink_txhash(sk);
1889
1890 if (dst && dst->ops->negative_advice) {
1891 ndst = dst->ops->negative_advice(dst);
1892
1893 if (ndst != dst) {
1894 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1895 sk_tx_queue_clear(sk);
1896 sk->sk_dst_pending_confirm = 0;
1897 }
1898 }
1899}
1900
1901static inline void
1902__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1903{
1904 struct dst_entry *old_dst;
1905
1906 sk_tx_queue_clear(sk);
1907 sk->sk_dst_pending_confirm = 0;
1908 old_dst = rcu_dereference_protected(sk->sk_dst_cache,
1909 lockdep_sock_is_held(sk));
1910 rcu_assign_pointer(sk->sk_dst_cache, dst);
1911 dst_release(old_dst);
1912}
1913
1914static inline void
1915sk_dst_set(struct sock *sk, struct dst_entry *dst)
1916{
1917 struct dst_entry *old_dst;
1918
1919 sk_tx_queue_clear(sk);
1920 sk->sk_dst_pending_confirm = 0;
1921 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1922 dst_release(old_dst);
1923}
1924
1925static inline void
1926__sk_dst_reset(struct sock *sk)
1927{
1928 __sk_dst_set(sk, NULL);
1929}
1930
1931static inline void
1932sk_dst_reset(struct sock *sk)
1933{
1934 sk_dst_set(sk, NULL);
1935}
1936
1937struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1938
1939struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1940
1941static inline void sk_dst_confirm(struct sock *sk)
1942{
1943 if (!sk->sk_dst_pending_confirm)
1944 sk->sk_dst_pending_confirm = 1;
1945}
1946
1947static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
1948{
1949 if (skb_get_dst_pending_confirm(skb)) {
1950 struct sock *sk = skb->sk;
1951 unsigned long now = jiffies;
1952
1953 /* avoid dirtying neighbour */
1954 if (n->confirmed != now)
1955 n->confirmed = now;
1956 if (sk && sk->sk_dst_pending_confirm)
1957 sk->sk_dst_pending_confirm = 0;
1958 }
1959}
1960
1961bool sk_mc_loop(struct sock *sk);
1962
1963static inline bool sk_can_gso(const struct sock *sk)
1964{
1965 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1966}
1967
1968void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1969
1970static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1971{
1972 sk->sk_route_nocaps |= flags;
1973 sk->sk_route_caps &= ~flags;
1974}
1975
1976static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1977 struct iov_iter *from, char *to,
1978 int copy, int offset)
1979{
1980 if (skb->ip_summed == CHECKSUM_NONE) {
1981 __wsum csum = 0;
1982 if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
1983 return -EFAULT;
1984 skb->csum = csum_block_add(skb->csum, csum, offset);
1985 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1986 if (!copy_from_iter_full_nocache(to, copy, from))
1987 return -EFAULT;
1988 } else if (!copy_from_iter_full(to, copy, from))
1989 return -EFAULT;
1990
1991 return 0;
1992}
1993
1994static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1995 struct iov_iter *from, int copy)
1996{
1997 int err, offset = skb->len;
1998
1999 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2000 copy, offset);
2001 if (err)
2002 __skb_trim(skb, offset);
2003
2004 return err;
2005}
2006
2007static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2008 struct sk_buff *skb,
2009 struct page *page,
2010 int off, int copy)
2011{
2012 int err;
2013
2014 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2015 copy, skb->len);
2016 if (err)
2017 return err;
2018
2019 skb->len += copy;
2020 skb->data_len += copy;
2021 skb->truesize += copy;
2022 sk_wmem_queued_add(sk, copy);
2023 sk_mem_charge(sk, copy);
2024 return 0;
2025}
2026
2027/**
2028 * sk_wmem_alloc_get - returns write allocations
2029 * @sk: socket
2030 *
2031 * Returns sk_wmem_alloc minus initial offset of one
2032 */
2033static inline int sk_wmem_alloc_get(const struct sock *sk)
2034{
2035 return refcount_read(&sk->sk_wmem_alloc) - 1;
2036}
2037
2038/**
2039 * sk_rmem_alloc_get - returns read allocations
2040 * @sk: socket
2041 *
2042 * Returns sk_rmem_alloc
2043 */
2044static inline int sk_rmem_alloc_get(const struct sock *sk)
2045{
2046 return atomic_read(&sk->sk_rmem_alloc);
2047}
2048
2049/**
2050 * sk_has_allocations - check if allocations are outstanding
2051 * @sk: socket
2052 *
2053 * Returns true if socket has write or read allocations
2054 */
2055static inline bool sk_has_allocations(const struct sock *sk)
2056{
2057 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2058}
2059
2060/**
2061 * skwq_has_sleeper - check if there are any waiting processes
2062 * @wq: struct socket_wq
2063 *
2064 * Returns true if socket_wq has waiting processes
2065 *
2066 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2067 * barrier call. They were added due to the race found within the tcp code.
2068 *
2069 * Consider following tcp code paths::
2070 *
2071 * CPU1 CPU2
2072 * sys_select receive packet
2073 * ... ...
2074 * __add_wait_queue update tp->rcv_nxt
2075 * ... ...
2076 * tp->rcv_nxt check sock_def_readable
2077 * ... {
2078 * schedule rcu_read_lock();
2079 * wq = rcu_dereference(sk->sk_wq);
2080 * if (wq && waitqueue_active(&wq->wait))
2081 * wake_up_interruptible(&wq->wait)
2082 * ...
2083 * }
2084 *
2085 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2086 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
2087 * could then endup calling schedule and sleep forever if there are no more
2088 * data on the socket.
2089 *
2090 */
2091static inline bool skwq_has_sleeper(struct socket_wq *wq)
2092{
2093 return wq && wq_has_sleeper(&wq->wait);
2094}
2095
2096/**
2097 * sock_poll_wait - place memory barrier behind the poll_wait call.
2098 * @filp: file
2099 * @sock: socket to wait on
2100 * @p: poll_table
2101 *
2102 * See the comments in the wq_has_sleeper function.
2103 */
2104static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2105 poll_table *p)
2106{
2107 if (!poll_does_not_wait(p)) {
2108 poll_wait(filp, &sock->wq.wait, p);
2109 /* We need to be sure we are in sync with the
2110 * socket flags modification.
2111 *
2112 * This memory barrier is paired in the wq_has_sleeper.
2113 */
2114 smp_mb();
2115 }
2116}
2117
2118static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2119{
2120 if (sk->sk_txhash) {
2121 skb->l4_hash = 1;
2122 skb->hash = sk->sk_txhash;
2123 }
2124}
2125
2126void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2127
2128/*
2129 * Queue a received datagram if it will fit. Stream and sequenced
2130 * protocols can't normally use this as they need to fit buffers in
2131 * and play with them.
2132 *
2133 * Inlined as it's very short and called for pretty much every
2134 * packet ever received.
2135 */
2136static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2137{
2138 skb_orphan(skb);
2139 skb->sk = sk;
2140 skb->destructor = sock_rfree;
2141 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2142 sk_mem_charge(sk, skb->truesize);
2143}
2144
2145void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2146 unsigned long expires);
2147
2148void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2149
2150int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2151 struct sk_buff *skb, unsigned int flags,
2152 void (*destructor)(struct sock *sk,
2153 struct sk_buff *skb));
2154int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2155int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2156
2157int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2158struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2159
2160/*
2161 * Recover an error report and clear atomically
2162 */
2163
2164static inline int sock_error(struct sock *sk)
2165{
2166 int err;
2167 if (likely(!sk->sk_err))
2168 return 0;
2169 err = xchg(&sk->sk_err, 0);
2170 return -err;
2171}
2172
2173static inline unsigned long sock_wspace(struct sock *sk)
2174{
2175 int amt = 0;
2176
2177 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2178 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2179 if (amt < 0)
2180 amt = 0;
2181 }
2182 return amt;
2183}
2184
2185/* Note:
2186 * We use sk->sk_wq_raw, from contexts knowing this
2187 * pointer is not NULL and cannot disappear/change.
2188 */
2189static inline void sk_set_bit(int nr, struct sock *sk)
2190{
2191 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2192 !sock_flag(sk, SOCK_FASYNC))
2193 return;
2194
2195 set_bit(nr, &sk->sk_wq_raw->flags);
2196}
2197
2198static inline void sk_clear_bit(int nr, struct sock *sk)
2199{
2200 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2201 !sock_flag(sk, SOCK_FASYNC))
2202 return;
2203
2204 clear_bit(nr, &sk->sk_wq_raw->flags);
2205}
2206
2207static inline void sk_wake_async(const struct sock *sk, int how, int band)
2208{
2209 if (sock_flag(sk, SOCK_FASYNC)) {
2210 rcu_read_lock();
2211 sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2212 rcu_read_unlock();
2213 }
2214}
2215
2216/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2217 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2218 * Note: for send buffers, TCP works better if we can build two skbs at
2219 * minimum.
2220 */
2221#define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2222
2223#define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
2224#define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
2225
2226static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2227{
2228 u32 val;
2229
2230 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2231 return;
2232
2233 val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2234
2235 WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2236}
2237
2238struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2239 bool force_schedule);
2240
2241/**
2242 * sk_page_frag - return an appropriate page_frag
2243 * @sk: socket
2244 *
2245 * Use the per task page_frag instead of the per socket one for
2246 * optimization when we know that we're in the normal context and owns
2247 * everything that's associated with %current.
2248 *
2249 * gfpflags_allow_blocking() isn't enough here as direct reclaim may nest
2250 * inside other socket operations and end up recursing into sk_page_frag()
2251 * while it's already in use.
2252 */
2253static inline struct page_frag *sk_page_frag(struct sock *sk)
2254{
2255 if (gfpflags_normal_context(sk->sk_allocation))
2256 return ¤t->task_frag;
2257
2258 return &sk->sk_frag;
2259}
2260
2261bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2262
2263/*
2264 * Default write policy as shown to user space via poll/select/SIGIO
2265 */
2266static inline bool sock_writeable(const struct sock *sk)
2267{
2268 return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2269}
2270
2271static inline gfp_t gfp_any(void)
2272{
2273 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2274}
2275
2276static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2277{
2278 return noblock ? 0 : sk->sk_rcvtimeo;
2279}
2280
2281static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2282{
2283 return noblock ? 0 : sk->sk_sndtimeo;
2284}
2285
2286static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2287{
2288 int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2289
2290 return v ?: 1;
2291}
2292
2293/* Alas, with timeout socket operations are not restartable.
2294 * Compare this to poll().
2295 */
2296static inline int sock_intr_errno(long timeo)
2297{
2298 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2299}
2300
2301struct sock_skb_cb {
2302 u32 dropcount;
2303};
2304
2305/* Store sock_skb_cb at the end of skb->cb[] so protocol families
2306 * using skb->cb[] would keep using it directly and utilize its
2307 * alignement guarantee.
2308 */
2309#define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \
2310 sizeof(struct sock_skb_cb)))
2311
2312#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2313 SOCK_SKB_CB_OFFSET))
2314
2315#define sock_skb_cb_check_size(size) \
2316 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2317
2318static inline void
2319sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2320{
2321 SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2322 atomic_read(&sk->sk_drops) : 0;
2323}
2324
2325static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2326{
2327 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2328
2329 atomic_add(segs, &sk->sk_drops);
2330}
2331
2332static inline ktime_t sock_read_timestamp(struct sock *sk)
2333{
2334#if BITS_PER_LONG==32
2335 unsigned int seq;
2336 ktime_t kt;
2337
2338 do {
2339 seq = read_seqbegin(&sk->sk_stamp_seq);
2340 kt = sk->sk_stamp;
2341 } while (read_seqretry(&sk->sk_stamp_seq, seq));
2342
2343 return kt;
2344#else
2345 return READ_ONCE(sk->sk_stamp);
2346#endif
2347}
2348
2349static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2350{
2351#if BITS_PER_LONG==32
2352 write_seqlock(&sk->sk_stamp_seq);
2353 sk->sk_stamp = kt;
2354 write_sequnlock(&sk->sk_stamp_seq);
2355#else
2356 WRITE_ONCE(sk->sk_stamp, kt);
2357#endif
2358}
2359
2360void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2361 struct sk_buff *skb);
2362void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2363 struct sk_buff *skb);
2364
2365static inline void
2366sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2367{
2368 ktime_t kt = skb->tstamp;
2369 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2370
2371 /*
2372 * generate control messages if
2373 * - receive time stamping in software requested
2374 * - software time stamp available and wanted
2375 * - hardware time stamps available and wanted
2376 */
2377 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2378 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2379 (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2380 (hwtstamps->hwtstamp &&
2381 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2382 __sock_recv_timestamp(msg, sk, skb);
2383 else
2384 sock_write_timestamp(sk, kt);
2385
2386 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2387 __sock_recv_wifi_status(msg, sk, skb);
2388}
2389
2390void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2391 struct sk_buff *skb);
2392
2393#define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2394static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2395 struct sk_buff *skb)
2396{
2397#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2398 (1UL << SOCK_RCVTSTAMP))
2399#define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \
2400 SOF_TIMESTAMPING_RAW_HARDWARE)
2401
2402 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2403 __sock_recv_ts_and_drops(msg, sk, skb);
2404 else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2405 sock_write_timestamp(sk, skb->tstamp);
2406 else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2407 sock_write_timestamp(sk, 0);
2408}
2409
2410void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2411
2412/**
2413 * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2414 * @sk: socket sending this packet
2415 * @tsflags: timestamping flags to use
2416 * @tx_flags: completed with instructions for time stamping
2417 * @tskey: filled in with next sk_tskey (not for TCP, which uses seqno)
2418 *
2419 * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2420 */
2421static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2422 __u8 *tx_flags, __u32 *tskey)
2423{
2424 if (unlikely(tsflags)) {
2425 __sock_tx_timestamp(tsflags, tx_flags);
2426 if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2427 tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2428 *tskey = sk->sk_tskey++;
2429 }
2430 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2431 *tx_flags |= SKBTX_WIFI_STATUS;
2432}
2433
2434static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2435 __u8 *tx_flags)
2436{
2437 _sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2438}
2439
2440static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2441{
2442 _sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2443 &skb_shinfo(skb)->tskey);
2444}
2445
2446/**
2447 * sk_eat_skb - Release a skb if it is no longer needed
2448 * @sk: socket to eat this skb from
2449 * @skb: socket buffer to eat
2450 *
2451 * This routine must be called with interrupts disabled or with the socket
2452 * locked so that the sk_buff queue operation is ok.
2453*/
2454DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
2455static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2456{
2457 __skb_unlink(skb, &sk->sk_receive_queue);
2458 if (static_branch_unlikely(&tcp_rx_skb_cache_key) &&
2459 !sk->sk_rx_skb_cache) {
2460 sk->sk_rx_skb_cache = skb;
2461 skb_orphan(skb);
2462 return;
2463 }
2464 __kfree_skb(skb);
2465}
2466
2467static inline
2468struct net *sock_net(const struct sock *sk)
2469{
2470 return read_pnet(&sk->sk_net);
2471}
2472
2473static inline
2474void sock_net_set(struct sock *sk, struct net *net)
2475{
2476 write_pnet(&sk->sk_net, net);
2477}
2478
2479static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2480{
2481 if (skb->sk) {
2482 struct sock *sk = skb->sk;
2483
2484 skb->destructor = NULL;
2485 skb->sk = NULL;
2486 return sk;
2487 }
2488 return NULL;
2489}
2490
2491/* This helper checks if a socket is a full socket,
2492 * ie _not_ a timewait or request socket.
2493 */
2494static inline bool sk_fullsock(const struct sock *sk)
2495{
2496 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2497}
2498
2499/* Checks if this SKB belongs to an HW offloaded socket
2500 * and whether any SW fallbacks are required based on dev.
2501 * Check decrypted mark in case skb_orphan() cleared socket.
2502 */
2503static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2504 struct net_device *dev)
2505{
2506#ifdef CONFIG_SOCK_VALIDATE_XMIT
2507 struct sock *sk = skb->sk;
2508
2509 if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2510 skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2511#ifdef CONFIG_TLS_DEVICE
2512 } else if (unlikely(skb->decrypted)) {
2513 pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2514 kfree_skb(skb);
2515 skb = NULL;
2516#endif
2517 }
2518#endif
2519
2520 return skb;
2521}
2522
2523/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2524 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2525 */
2526static inline bool sk_listener(const struct sock *sk)
2527{
2528 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2529}
2530
2531void sock_enable_timestamp(struct sock *sk, int flag);
2532int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2533 int type);
2534
2535bool sk_ns_capable(const struct sock *sk,
2536 struct user_namespace *user_ns, int cap);
2537bool sk_capable(const struct sock *sk, int cap);
2538bool sk_net_capable(const struct sock *sk, int cap);
2539
2540void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2541
2542/* Take into consideration the size of the struct sk_buff overhead in the
2543 * determination of these values, since that is non-constant across
2544 * platforms. This makes socket queueing behavior and performance
2545 * not depend upon such differences.
2546 */
2547#define _SK_MEM_PACKETS 256
2548#define _SK_MEM_OVERHEAD SKB_TRUESIZE(256)
2549#define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2550#define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2551
2552extern __u32 sysctl_wmem_max;
2553extern __u32 sysctl_rmem_max;
2554
2555extern int sysctl_tstamp_allow_data;
2556extern int sysctl_optmem_max;
2557
2558extern __u32 sysctl_wmem_default;
2559extern __u32 sysctl_rmem_default;
2560
2561DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2562
2563static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2564{
2565 /* Does this proto have per netns sysctl_wmem ? */
2566 if (proto->sysctl_wmem_offset)
2567 return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2568
2569 return *proto->sysctl_wmem;
2570}
2571
2572static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2573{
2574 /* Does this proto have per netns sysctl_rmem ? */
2575 if (proto->sysctl_rmem_offset)
2576 return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2577
2578 return *proto->sysctl_rmem;
2579}
2580
2581/* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2582 * Some wifi drivers need to tweak it to get more chunks.
2583 * They can use this helper from their ndo_start_xmit()
2584 */
2585static inline void sk_pacing_shift_update(struct sock *sk, int val)
2586{
2587 if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val)
2588 return;
2589 sk->sk_pacing_shift = val;
2590}
2591
2592/* if a socket is bound to a device, check that the given device
2593 * index is either the same or that the socket is bound to an L3
2594 * master device and the given device index is also enslaved to
2595 * that L3 master
2596 */
2597static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2598{
2599 int mdif;
2600
2601 if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2602 return true;
2603
2604 mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2605 if (mdif && mdif == sk->sk_bound_dev_if)
2606 return true;
2607
2608 return false;
2609}
2610
2611#endif /* _SOCK_H */
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/page_counter.h>
58#include <linux/memcontrol.h>
59#include <linux/static_key.h>
60#include <linux/sched.h>
61#include <linux/wait.h>
62#include <linux/cgroup-defs.h>
63
64#include <linux/filter.h>
65#include <linux/rculist_nulls.h>
66#include <linux/poll.h>
67
68#include <linux/atomic.h>
69#include <net/dst.h>
70#include <net/checksum.h>
71#include <net/tcp_states.h>
72#include <linux/net_tstamp.h>
73
74/*
75 * This structure really needs to be cleaned up.
76 * Most of it is for TCP, and not used by any of
77 * the other protocols.
78 */
79
80/* Define this to get the SOCK_DBG debugging facility. */
81#define SOCK_DEBUGGING
82#ifdef SOCK_DEBUGGING
83#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
84 printk(KERN_DEBUG msg); } while (0)
85#else
86/* Validate arguments and do nothing */
87static inline __printf(2, 3)
88void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
89{
90}
91#endif
92
93/* This is the per-socket lock. The spinlock provides a synchronization
94 * between user contexts and software interrupt processing, whereas the
95 * mini-semaphore synchronizes multiple users amongst themselves.
96 */
97typedef struct {
98 spinlock_t slock;
99 int owned;
100 wait_queue_head_t wq;
101 /*
102 * We express the mutex-alike socket_lock semantics
103 * to the lock validator by explicitly managing
104 * the slock as a lock variant (in addition to
105 * the slock itself):
106 */
107#ifdef CONFIG_DEBUG_LOCK_ALLOC
108 struct lockdep_map dep_map;
109#endif
110} socket_lock_t;
111
112struct sock;
113struct proto;
114struct net;
115
116typedef __u32 __bitwise __portpair;
117typedef __u64 __bitwise __addrpair;
118
119/**
120 * struct sock_common - minimal network layer representation of sockets
121 * @skc_daddr: Foreign IPv4 addr
122 * @skc_rcv_saddr: Bound local IPv4 addr
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_family: network address family
128 * @skc_state: Connection state
129 * @skc_reuse: %SO_REUSEADDR setting
130 * @skc_reuseport: %SO_REUSEPORT setting
131 * @skc_bound_dev_if: bound device index if != 0
132 * @skc_bind_node: bind hash linkage for various protocol lookup tables
133 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
134 * @skc_prot: protocol handlers inside a network family
135 * @skc_net: reference to the network namespace of this socket
136 * @skc_node: main hash linkage for various protocol lookup tables
137 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
138 * @skc_tx_queue_mapping: tx queue number for this connection
139 * @skc_flags: place holder for sk_flags
140 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
141 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
142 * @skc_incoming_cpu: record/match cpu processing incoming packets
143 * @skc_refcnt: reference count
144 *
145 * This is the minimal network layer representation of sockets, the header
146 * for struct sock and struct inet_timewait_sock.
147 */
148struct sock_common {
149 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
150 * address on 64bit arches : cf INET_MATCH()
151 */
152 union {
153 __addrpair skc_addrpair;
154 struct {
155 __be32 skc_daddr;
156 __be32 skc_rcv_saddr;
157 };
158 };
159 union {
160 unsigned int skc_hash;
161 __u16 skc_u16hashes[2];
162 };
163 /* skc_dport && skc_num must be grouped as well */
164 union {
165 __portpair skc_portpair;
166 struct {
167 __be16 skc_dport;
168 __u16 skc_num;
169 };
170 };
171
172 unsigned short skc_family;
173 volatile unsigned char skc_state;
174 unsigned char skc_reuse:4;
175 unsigned char skc_reuseport:1;
176 unsigned char skc_ipv6only:1;
177 unsigned char skc_net_refcnt:1;
178 int skc_bound_dev_if;
179 union {
180 struct hlist_node skc_bind_node;
181 struct hlist_node skc_portaddr_node;
182 };
183 struct proto *skc_prot;
184 possible_net_t skc_net;
185
186#if IS_ENABLED(CONFIG_IPV6)
187 struct in6_addr skc_v6_daddr;
188 struct in6_addr skc_v6_rcv_saddr;
189#endif
190
191 atomic64_t skc_cookie;
192
193 /* following fields are padding to force
194 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
195 * assuming IPV6 is enabled. We use this padding differently
196 * for different kind of 'sockets'
197 */
198 union {
199 unsigned long skc_flags;
200 struct sock *skc_listener; /* request_sock */
201 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
202 };
203 /*
204 * fields between dontcopy_begin/dontcopy_end
205 * are not copied in sock_copy()
206 */
207 /* private: */
208 int skc_dontcopy_begin[0];
209 /* public: */
210 union {
211 struct hlist_node skc_node;
212 struct hlist_nulls_node skc_nulls_node;
213 };
214 int skc_tx_queue_mapping;
215 union {
216 int skc_incoming_cpu;
217 u32 skc_rcv_wnd;
218 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */
219 };
220
221 atomic_t skc_refcnt;
222 /* private: */
223 int skc_dontcopy_end[0];
224 union {
225 u32 skc_rxhash;
226 u32 skc_window_clamp;
227 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */
228 };
229 /* public: */
230};
231
232/**
233 * struct sock - network layer representation of sockets
234 * @__sk_common: shared layout with inet_timewait_sock
235 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
236 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
237 * @sk_lock: synchronizer
238 * @sk_rcvbuf: size of receive buffer in bytes
239 * @sk_wq: sock wait queue and async head
240 * @sk_rx_dst: receive input route used by early demux
241 * @sk_dst_cache: destination cache
242 * @sk_policy: flow policy
243 * @sk_receive_queue: incoming packets
244 * @sk_wmem_alloc: transmit queue bytes committed
245 * @sk_write_queue: Packet sending queue
246 * @sk_omem_alloc: "o" is "option" or "other"
247 * @sk_wmem_queued: persistent queue size
248 * @sk_forward_alloc: space allocated forward
249 * @sk_napi_id: id of the last napi context to receive data for sk
250 * @sk_ll_usec: usecs to busypoll when there is no data
251 * @sk_allocation: allocation mode
252 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
253 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
254 * @sk_sndbuf: size of send buffer in bytes
255 * @sk_padding: unused element for alignment
256 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
257 * @sk_no_check_rx: allow zero checksum in RX packets
258 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
259 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
260 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
261 * @sk_gso_max_size: Maximum GSO segment size to build
262 * @sk_gso_max_segs: Maximum number of GSO segments
263 * @sk_lingertime: %SO_LINGER l_linger setting
264 * @sk_backlog: always used with the per-socket spinlock held
265 * @sk_callback_lock: used with the callbacks in the end of this struct
266 * @sk_error_queue: rarely used
267 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
268 * IPV6_ADDRFORM for instance)
269 * @sk_err: last error
270 * @sk_err_soft: errors that don't cause failure but are the cause of a
271 * persistent failure not just 'timed out'
272 * @sk_drops: raw/udp drops counter
273 * @sk_ack_backlog: current listen backlog
274 * @sk_max_ack_backlog: listen backlog set in listen()
275 * @sk_priority: %SO_PRIORITY setting
276 * @sk_type: socket type (%SOCK_STREAM, etc)
277 * @sk_protocol: which protocol this socket belongs in this network family
278 * @sk_peer_pid: &struct pid for this socket's peer
279 * @sk_peer_cred: %SO_PEERCRED setting
280 * @sk_rcvlowat: %SO_RCVLOWAT setting
281 * @sk_rcvtimeo: %SO_RCVTIMEO setting
282 * @sk_sndtimeo: %SO_SNDTIMEO setting
283 * @sk_txhash: computed flow hash for use on transmit
284 * @sk_filter: socket filtering instructions
285 * @sk_timer: sock cleanup timer
286 * @sk_stamp: time stamp of last packet received
287 * @sk_tsflags: SO_TIMESTAMPING socket options
288 * @sk_tskey: counter to disambiguate concurrent tstamp requests
289 * @sk_socket: Identd and reporting IO signals
290 * @sk_user_data: RPC layer private data
291 * @sk_frag: cached page frag
292 * @sk_peek_off: current peek_offset value
293 * @sk_send_head: front of stuff to transmit
294 * @sk_security: used by security modules
295 * @sk_mark: generic packet mark
296 * @sk_cgrp_data: cgroup data for this cgroup
297 * @sk_memcg: this socket's memory cgroup association
298 * @sk_write_pending: a write to stream socket waits to start
299 * @sk_state_change: callback to indicate change in the state of the sock
300 * @sk_data_ready: callback to indicate there is data to be processed
301 * @sk_write_space: callback to indicate there is bf sending space available
302 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
303 * @sk_backlog_rcv: callback to process the backlog
304 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
305 * @sk_reuseport_cb: reuseport group container
306 * @sk_rcu: used during RCU grace period
307 */
308struct sock {
309 /*
310 * Now struct inet_timewait_sock also uses sock_common, so please just
311 * don't add nothing before this first member (__sk_common) --acme
312 */
313 struct sock_common __sk_common;
314#define sk_node __sk_common.skc_node
315#define sk_nulls_node __sk_common.skc_nulls_node
316#define sk_refcnt __sk_common.skc_refcnt
317#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
318
319#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
320#define sk_dontcopy_end __sk_common.skc_dontcopy_end
321#define sk_hash __sk_common.skc_hash
322#define sk_portpair __sk_common.skc_portpair
323#define sk_num __sk_common.skc_num
324#define sk_dport __sk_common.skc_dport
325#define sk_addrpair __sk_common.skc_addrpair
326#define sk_daddr __sk_common.skc_daddr
327#define sk_rcv_saddr __sk_common.skc_rcv_saddr
328#define sk_family __sk_common.skc_family
329#define sk_state __sk_common.skc_state
330#define sk_reuse __sk_common.skc_reuse
331#define sk_reuseport __sk_common.skc_reuseport
332#define sk_ipv6only __sk_common.skc_ipv6only
333#define sk_net_refcnt __sk_common.skc_net_refcnt
334#define sk_bound_dev_if __sk_common.skc_bound_dev_if
335#define sk_bind_node __sk_common.skc_bind_node
336#define sk_prot __sk_common.skc_prot
337#define sk_net __sk_common.skc_net
338#define sk_v6_daddr __sk_common.skc_v6_daddr
339#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
340#define sk_cookie __sk_common.skc_cookie
341#define sk_incoming_cpu __sk_common.skc_incoming_cpu
342#define sk_flags __sk_common.skc_flags
343#define sk_rxhash __sk_common.skc_rxhash
344
345 socket_lock_t sk_lock;
346 atomic_t sk_drops;
347 int sk_rcvlowat;
348 struct sk_buff_head sk_error_queue;
349 struct sk_buff_head sk_receive_queue;
350 /*
351 * The backlog queue is special, it is always used with
352 * the per-socket spinlock held and requires low latency
353 * access. Therefore we special case it's implementation.
354 * Note : rmem_alloc is in this structure to fill a hole
355 * on 64bit arches, not because its logically part of
356 * backlog.
357 */
358 struct {
359 atomic_t rmem_alloc;
360 int len;
361 struct sk_buff *head;
362 struct sk_buff *tail;
363 } sk_backlog;
364#define sk_rmem_alloc sk_backlog.rmem_alloc
365
366 int sk_forward_alloc;
367#ifdef CONFIG_NET_RX_BUSY_POLL
368 unsigned int sk_ll_usec;
369 /* ===== mostly read cache line ===== */
370 unsigned int sk_napi_id;
371#endif
372 int sk_rcvbuf;
373
374 struct sk_filter __rcu *sk_filter;
375 union {
376 struct socket_wq __rcu *sk_wq;
377 struct socket_wq *sk_wq_raw;
378 };
379#ifdef CONFIG_XFRM
380 struct xfrm_policy __rcu *sk_policy[2];
381#endif
382 struct dst_entry *sk_rx_dst;
383 struct dst_entry __rcu *sk_dst_cache;
384 atomic_t sk_omem_alloc;
385 int sk_sndbuf;
386
387 /* ===== cache line for TX ===== */
388 int sk_wmem_queued;
389 atomic_t sk_wmem_alloc;
390 unsigned long sk_tsq_flags;
391 struct sk_buff *sk_send_head;
392 struct sk_buff_head sk_write_queue;
393 __s32 sk_peek_off;
394 int sk_write_pending;
395 long sk_sndtimeo;
396 struct timer_list sk_timer;
397 __u32 sk_priority;
398 __u32 sk_mark;
399 u32 sk_pacing_rate; /* bytes per second */
400 u32 sk_max_pacing_rate;
401 struct page_frag sk_frag;
402 netdev_features_t sk_route_caps;
403 netdev_features_t sk_route_nocaps;
404 int sk_gso_type;
405 unsigned int sk_gso_max_size;
406 gfp_t sk_allocation;
407 __u32 sk_txhash;
408
409 /*
410 * Because of non atomicity rules, all
411 * changes are protected by socket lock.
412 */
413 unsigned int __sk_flags_offset[0];
414#ifdef __BIG_ENDIAN_BITFIELD
415#define SK_FL_PROTO_SHIFT 16
416#define SK_FL_PROTO_MASK 0x00ff0000
417
418#define SK_FL_TYPE_SHIFT 0
419#define SK_FL_TYPE_MASK 0x0000ffff
420#else
421#define SK_FL_PROTO_SHIFT 8
422#define SK_FL_PROTO_MASK 0x0000ff00
423
424#define SK_FL_TYPE_SHIFT 16
425#define SK_FL_TYPE_MASK 0xffff0000
426#endif
427
428 kmemcheck_bitfield_begin(flags);
429 unsigned int sk_padding : 2,
430 sk_no_check_tx : 1,
431 sk_no_check_rx : 1,
432 sk_userlocks : 4,
433 sk_protocol : 8,
434 sk_type : 16;
435#define SK_PROTOCOL_MAX U8_MAX
436 kmemcheck_bitfield_end(flags);
437
438 u16 sk_gso_max_segs;
439 unsigned long sk_lingertime;
440 struct proto *sk_prot_creator;
441 rwlock_t sk_callback_lock;
442 int sk_err,
443 sk_err_soft;
444 u32 sk_ack_backlog;
445 u32 sk_max_ack_backlog;
446 kuid_t sk_uid;
447 struct pid *sk_peer_pid;
448 const struct cred *sk_peer_cred;
449 long sk_rcvtimeo;
450 ktime_t sk_stamp;
451 u16 sk_tsflags;
452 u8 sk_shutdown;
453 u32 sk_tskey;
454 struct socket *sk_socket;
455 void *sk_user_data;
456#ifdef CONFIG_SECURITY
457 void *sk_security;
458#endif
459 struct sock_cgroup_data sk_cgrp_data;
460 struct mem_cgroup *sk_memcg;
461 void (*sk_state_change)(struct sock *sk);
462 void (*sk_data_ready)(struct sock *sk);
463 void (*sk_write_space)(struct sock *sk);
464 void (*sk_error_report)(struct sock *sk);
465 int (*sk_backlog_rcv)(struct sock *sk,
466 struct sk_buff *skb);
467 void (*sk_destruct)(struct sock *sk);
468 struct sock_reuseport __rcu *sk_reuseport_cb;
469 struct rcu_head sk_rcu;
470};
471
472#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
473
474#define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk)))
475#define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr)
476
477/*
478 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
479 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
480 * on a socket means that the socket will reuse everybody else's port
481 * without looking at the other's sk_reuse value.
482 */
483
484#define SK_NO_REUSE 0
485#define SK_CAN_REUSE 1
486#define SK_FORCE_REUSE 2
487
488int sk_set_peek_off(struct sock *sk, int val);
489
490static inline int sk_peek_offset(struct sock *sk, int flags)
491{
492 if (unlikely(flags & MSG_PEEK)) {
493 s32 off = READ_ONCE(sk->sk_peek_off);
494 if (off >= 0)
495 return off;
496 }
497
498 return 0;
499}
500
501static inline void sk_peek_offset_bwd(struct sock *sk, int val)
502{
503 s32 off = READ_ONCE(sk->sk_peek_off);
504
505 if (unlikely(off >= 0)) {
506 off = max_t(s32, off - val, 0);
507 WRITE_ONCE(sk->sk_peek_off, off);
508 }
509}
510
511static inline void sk_peek_offset_fwd(struct sock *sk, int val)
512{
513 sk_peek_offset_bwd(sk, -val);
514}
515
516/*
517 * Hashed lists helper routines
518 */
519static inline struct sock *sk_entry(const struct hlist_node *node)
520{
521 return hlist_entry(node, struct sock, sk_node);
522}
523
524static inline struct sock *__sk_head(const struct hlist_head *head)
525{
526 return hlist_entry(head->first, struct sock, sk_node);
527}
528
529static inline struct sock *sk_head(const struct hlist_head *head)
530{
531 return hlist_empty(head) ? NULL : __sk_head(head);
532}
533
534static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
535{
536 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
537}
538
539static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
540{
541 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
542}
543
544static inline struct sock *sk_next(const struct sock *sk)
545{
546 return sk->sk_node.next ?
547 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
548}
549
550static inline struct sock *sk_nulls_next(const struct sock *sk)
551{
552 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
553 hlist_nulls_entry(sk->sk_nulls_node.next,
554 struct sock, sk_nulls_node) :
555 NULL;
556}
557
558static inline bool sk_unhashed(const struct sock *sk)
559{
560 return hlist_unhashed(&sk->sk_node);
561}
562
563static inline bool sk_hashed(const struct sock *sk)
564{
565 return !sk_unhashed(sk);
566}
567
568static inline void sk_node_init(struct hlist_node *node)
569{
570 node->pprev = NULL;
571}
572
573static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
574{
575 node->pprev = NULL;
576}
577
578static inline void __sk_del_node(struct sock *sk)
579{
580 __hlist_del(&sk->sk_node);
581}
582
583/* NB: equivalent to hlist_del_init_rcu */
584static inline bool __sk_del_node_init(struct sock *sk)
585{
586 if (sk_hashed(sk)) {
587 __sk_del_node(sk);
588 sk_node_init(&sk->sk_node);
589 return true;
590 }
591 return false;
592}
593
594/* Grab socket reference count. This operation is valid only
595 when sk is ALREADY grabbed f.e. it is found in hash table
596 or a list and the lookup is made under lock preventing hash table
597 modifications.
598 */
599
600static __always_inline void sock_hold(struct sock *sk)
601{
602 atomic_inc(&sk->sk_refcnt);
603}
604
605/* Ungrab socket in the context, which assumes that socket refcnt
606 cannot hit zero, f.e. it is true in context of any socketcall.
607 */
608static __always_inline void __sock_put(struct sock *sk)
609{
610 atomic_dec(&sk->sk_refcnt);
611}
612
613static inline bool sk_del_node_init(struct sock *sk)
614{
615 bool rc = __sk_del_node_init(sk);
616
617 if (rc) {
618 /* paranoid for a while -acme */
619 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
620 __sock_put(sk);
621 }
622 return rc;
623}
624#define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
625
626static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
627{
628 if (sk_hashed(sk)) {
629 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
630 return true;
631 }
632 return false;
633}
634
635static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
636{
637 bool rc = __sk_nulls_del_node_init_rcu(sk);
638
639 if (rc) {
640 /* paranoid for a while -acme */
641 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
642 __sock_put(sk);
643 }
644 return rc;
645}
646
647static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
648{
649 hlist_add_head(&sk->sk_node, list);
650}
651
652static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
653{
654 sock_hold(sk);
655 __sk_add_node(sk, list);
656}
657
658static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
659{
660 sock_hold(sk);
661 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
662 sk->sk_family == AF_INET6)
663 hlist_add_tail_rcu(&sk->sk_node, list);
664 else
665 hlist_add_head_rcu(&sk->sk_node, list);
666}
667
668static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
669{
670 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
671 sk->sk_family == AF_INET6)
672 hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
673 else
674 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
675}
676
677static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
678{
679 sock_hold(sk);
680 __sk_nulls_add_node_rcu(sk, list);
681}
682
683static inline void __sk_del_bind_node(struct sock *sk)
684{
685 __hlist_del(&sk->sk_bind_node);
686}
687
688static inline void sk_add_bind_node(struct sock *sk,
689 struct hlist_head *list)
690{
691 hlist_add_head(&sk->sk_bind_node, list);
692}
693
694#define sk_for_each(__sk, list) \
695 hlist_for_each_entry(__sk, list, sk_node)
696#define sk_for_each_rcu(__sk, list) \
697 hlist_for_each_entry_rcu(__sk, list, sk_node)
698#define sk_nulls_for_each(__sk, node, list) \
699 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
700#define sk_nulls_for_each_rcu(__sk, node, list) \
701 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
702#define sk_for_each_from(__sk) \
703 hlist_for_each_entry_from(__sk, sk_node)
704#define sk_nulls_for_each_from(__sk, node) \
705 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
706 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
707#define sk_for_each_safe(__sk, tmp, list) \
708 hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
709#define sk_for_each_bound(__sk, list) \
710 hlist_for_each_entry(__sk, list, sk_bind_node)
711
712/**
713 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
714 * @tpos: the type * to use as a loop cursor.
715 * @pos: the &struct hlist_node to use as a loop cursor.
716 * @head: the head for your list.
717 * @offset: offset of hlist_node within the struct.
718 *
719 */
720#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \
721 for (pos = rcu_dereference((head)->first); \
722 pos != NULL && \
723 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \
724 pos = rcu_dereference(pos->next))
725
726static inline struct user_namespace *sk_user_ns(struct sock *sk)
727{
728 /* Careful only use this in a context where these parameters
729 * can not change and must all be valid, such as recvmsg from
730 * userspace.
731 */
732 return sk->sk_socket->file->f_cred->user_ns;
733}
734
735/* Sock flags */
736enum sock_flags {
737 SOCK_DEAD,
738 SOCK_DONE,
739 SOCK_URGINLINE,
740 SOCK_KEEPOPEN,
741 SOCK_LINGER,
742 SOCK_DESTROY,
743 SOCK_BROADCAST,
744 SOCK_TIMESTAMP,
745 SOCK_ZAPPED,
746 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
747 SOCK_DBG, /* %SO_DEBUG setting */
748 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
749 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
750 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
751 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
752 SOCK_MEMALLOC, /* VM depends on this socket for swapping */
753 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
754 SOCK_FASYNC, /* fasync() active */
755 SOCK_RXQ_OVFL,
756 SOCK_ZEROCOPY, /* buffers from userspace */
757 SOCK_WIFI_STATUS, /* push wifi status to userspace */
758 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
759 * Will use last 4 bytes of packet sent from
760 * user-space instead.
761 */
762 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
763 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
764 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
765};
766
767#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
768
769static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
770{
771 nsk->sk_flags = osk->sk_flags;
772}
773
774static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
775{
776 __set_bit(flag, &sk->sk_flags);
777}
778
779static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
780{
781 __clear_bit(flag, &sk->sk_flags);
782}
783
784static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
785{
786 return test_bit(flag, &sk->sk_flags);
787}
788
789#ifdef CONFIG_NET
790extern struct static_key memalloc_socks;
791static inline int sk_memalloc_socks(void)
792{
793 return static_key_false(&memalloc_socks);
794}
795#else
796
797static inline int sk_memalloc_socks(void)
798{
799 return 0;
800}
801
802#endif
803
804static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
805{
806 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
807}
808
809static inline void sk_acceptq_removed(struct sock *sk)
810{
811 sk->sk_ack_backlog--;
812}
813
814static inline void sk_acceptq_added(struct sock *sk)
815{
816 sk->sk_ack_backlog++;
817}
818
819static inline bool sk_acceptq_is_full(const struct sock *sk)
820{
821 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
822}
823
824/*
825 * Compute minimal free write space needed to queue new packets.
826 */
827static inline int sk_stream_min_wspace(const struct sock *sk)
828{
829 return sk->sk_wmem_queued >> 1;
830}
831
832static inline int sk_stream_wspace(const struct sock *sk)
833{
834 return sk->sk_sndbuf - sk->sk_wmem_queued;
835}
836
837void sk_stream_write_space(struct sock *sk);
838
839/* OOB backlog add */
840static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
841{
842 /* dont let skb dst not refcounted, we are going to leave rcu lock */
843 skb_dst_force_safe(skb);
844
845 if (!sk->sk_backlog.tail)
846 sk->sk_backlog.head = skb;
847 else
848 sk->sk_backlog.tail->next = skb;
849
850 sk->sk_backlog.tail = skb;
851 skb->next = NULL;
852}
853
854/*
855 * Take into account size of receive queue and backlog queue
856 * Do not take into account this skb truesize,
857 * to allow even a single big packet to come.
858 */
859static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
860{
861 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
862
863 return qsize > limit;
864}
865
866/* The per-socket spinlock must be held here. */
867static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
868 unsigned int limit)
869{
870 if (sk_rcvqueues_full(sk, limit))
871 return -ENOBUFS;
872
873 /*
874 * If the skb was allocated from pfmemalloc reserves, only
875 * allow SOCK_MEMALLOC sockets to use it as this socket is
876 * helping free memory
877 */
878 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
879 return -ENOMEM;
880
881 __sk_add_backlog(sk, skb);
882 sk->sk_backlog.len += skb->truesize;
883 return 0;
884}
885
886int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
887
888static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
889{
890 if (sk_memalloc_socks() && skb_pfmemalloc(skb))
891 return __sk_backlog_rcv(sk, skb);
892
893 return sk->sk_backlog_rcv(sk, skb);
894}
895
896static inline void sk_incoming_cpu_update(struct sock *sk)
897{
898 sk->sk_incoming_cpu = raw_smp_processor_id();
899}
900
901static inline void sock_rps_record_flow_hash(__u32 hash)
902{
903#ifdef CONFIG_RPS
904 struct rps_sock_flow_table *sock_flow_table;
905
906 rcu_read_lock();
907 sock_flow_table = rcu_dereference(rps_sock_flow_table);
908 rps_record_sock_flow(sock_flow_table, hash);
909 rcu_read_unlock();
910#endif
911}
912
913static inline void sock_rps_record_flow(const struct sock *sk)
914{
915#ifdef CONFIG_RPS
916 if (static_key_false(&rfs_needed)) {
917 /* Reading sk->sk_rxhash might incur an expensive cache line
918 * miss.
919 *
920 * TCP_ESTABLISHED does cover almost all states where RFS
921 * might be useful, and is cheaper [1] than testing :
922 * IPv4: inet_sk(sk)->inet_daddr
923 * IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
924 * OR an additional socket flag
925 * [1] : sk_state and sk_prot are in the same cache line.
926 */
927 if (sk->sk_state == TCP_ESTABLISHED)
928 sock_rps_record_flow_hash(sk->sk_rxhash);
929 }
930#endif
931}
932
933static inline void sock_rps_save_rxhash(struct sock *sk,
934 const struct sk_buff *skb)
935{
936#ifdef CONFIG_RPS
937 if (unlikely(sk->sk_rxhash != skb->hash))
938 sk->sk_rxhash = skb->hash;
939#endif
940}
941
942static inline void sock_rps_reset_rxhash(struct sock *sk)
943{
944#ifdef CONFIG_RPS
945 sk->sk_rxhash = 0;
946#endif
947}
948
949#define sk_wait_event(__sk, __timeo, __condition, __wait) \
950 ({ int __rc; \
951 release_sock(__sk); \
952 __rc = __condition; \
953 if (!__rc) { \
954 *(__timeo) = wait_woken(__wait, \
955 TASK_INTERRUPTIBLE, \
956 *(__timeo)); \
957 } \
958 sched_annotate_sleep(); \
959 lock_sock(__sk); \
960 __rc = __condition; \
961 __rc; \
962 })
963
964int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
965int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
966void sk_stream_wait_close(struct sock *sk, long timeo_p);
967int sk_stream_error(struct sock *sk, int flags, int err);
968void sk_stream_kill_queues(struct sock *sk);
969void sk_set_memalloc(struct sock *sk);
970void sk_clear_memalloc(struct sock *sk);
971
972void __sk_flush_backlog(struct sock *sk);
973
974static inline bool sk_flush_backlog(struct sock *sk)
975{
976 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
977 __sk_flush_backlog(sk);
978 return true;
979 }
980 return false;
981}
982
983int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
984
985struct request_sock_ops;
986struct timewait_sock_ops;
987struct inet_hashinfo;
988struct raw_hashinfo;
989struct module;
990
991/*
992 * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
993 * un-modified. Special care is taken when initializing object to zero.
994 */
995static inline void sk_prot_clear_nulls(struct sock *sk, int size)
996{
997 if (offsetof(struct sock, sk_node.next) != 0)
998 memset(sk, 0, offsetof(struct sock, sk_node.next));
999 memset(&sk->sk_node.pprev, 0,
1000 size - offsetof(struct sock, sk_node.pprev));
1001}
1002
1003/* Networking protocol blocks we attach to sockets.
1004 * socket layer -> transport layer interface
1005 */
1006struct proto {
1007 void (*close)(struct sock *sk,
1008 long timeout);
1009 int (*connect)(struct sock *sk,
1010 struct sockaddr *uaddr,
1011 int addr_len);
1012 int (*disconnect)(struct sock *sk, int flags);
1013
1014 struct sock * (*accept)(struct sock *sk, int flags, int *err);
1015
1016 int (*ioctl)(struct sock *sk, int cmd,
1017 unsigned long arg);
1018 int (*init)(struct sock *sk);
1019 void (*destroy)(struct sock *sk);
1020 void (*shutdown)(struct sock *sk, int how);
1021 int (*setsockopt)(struct sock *sk, int level,
1022 int optname, char __user *optval,
1023 unsigned int optlen);
1024 int (*getsockopt)(struct sock *sk, int level,
1025 int optname, char __user *optval,
1026 int __user *option);
1027#ifdef CONFIG_COMPAT
1028 int (*compat_setsockopt)(struct sock *sk,
1029 int level,
1030 int optname, char __user *optval,
1031 unsigned int optlen);
1032 int (*compat_getsockopt)(struct sock *sk,
1033 int level,
1034 int optname, char __user *optval,
1035 int __user *option);
1036 int (*compat_ioctl)(struct sock *sk,
1037 unsigned int cmd, unsigned long arg);
1038#endif
1039 int (*sendmsg)(struct sock *sk, struct msghdr *msg,
1040 size_t len);
1041 int (*recvmsg)(struct sock *sk, struct msghdr *msg,
1042 size_t len, int noblock, int flags,
1043 int *addr_len);
1044 int (*sendpage)(struct sock *sk, struct page *page,
1045 int offset, size_t size, int flags);
1046 int (*bind)(struct sock *sk,
1047 struct sockaddr *uaddr, int addr_len);
1048
1049 int (*backlog_rcv) (struct sock *sk,
1050 struct sk_buff *skb);
1051
1052 void (*release_cb)(struct sock *sk);
1053
1054 /* Keeping track of sk's, looking them up, and port selection methods. */
1055 int (*hash)(struct sock *sk);
1056 void (*unhash)(struct sock *sk);
1057 void (*rehash)(struct sock *sk);
1058 int (*get_port)(struct sock *sk, unsigned short snum);
1059
1060 /* Keeping track of sockets in use */
1061#ifdef CONFIG_PROC_FS
1062 unsigned int inuse_idx;
1063#endif
1064
1065 bool (*stream_memory_free)(const struct sock *sk);
1066 /* Memory pressure */
1067 void (*enter_memory_pressure)(struct sock *sk);
1068 atomic_long_t *memory_allocated; /* Current allocated memory. */
1069 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
1070 /*
1071 * Pressure flag: try to collapse.
1072 * Technical note: it is used by multiple contexts non atomically.
1073 * All the __sk_mem_schedule() is of this nature: accounting
1074 * is strict, actions are advisory and have some latency.
1075 */
1076 int *memory_pressure;
1077 long *sysctl_mem;
1078 int *sysctl_wmem;
1079 int *sysctl_rmem;
1080 int max_header;
1081 bool no_autobind;
1082
1083 struct kmem_cache *slab;
1084 unsigned int obj_size;
1085 int slab_flags;
1086
1087 struct percpu_counter *orphan_count;
1088
1089 struct request_sock_ops *rsk_prot;
1090 struct timewait_sock_ops *twsk_prot;
1091
1092 union {
1093 struct inet_hashinfo *hashinfo;
1094 struct udp_table *udp_table;
1095 struct raw_hashinfo *raw_hash;
1096 } h;
1097
1098 struct module *owner;
1099
1100 char name[32];
1101
1102 struct list_head node;
1103#ifdef SOCK_REFCNT_DEBUG
1104 atomic_t socks;
1105#endif
1106 int (*diag_destroy)(struct sock *sk, int err);
1107};
1108
1109int proto_register(struct proto *prot, int alloc_slab);
1110void proto_unregister(struct proto *prot);
1111
1112#ifdef SOCK_REFCNT_DEBUG
1113static inline void sk_refcnt_debug_inc(struct sock *sk)
1114{
1115 atomic_inc(&sk->sk_prot->socks);
1116}
1117
1118static inline void sk_refcnt_debug_dec(struct sock *sk)
1119{
1120 atomic_dec(&sk->sk_prot->socks);
1121 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1122 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1123}
1124
1125static inline void sk_refcnt_debug_release(const struct sock *sk)
1126{
1127 if (atomic_read(&sk->sk_refcnt) != 1)
1128 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1129 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
1130}
1131#else /* SOCK_REFCNT_DEBUG */
1132#define sk_refcnt_debug_inc(sk) do { } while (0)
1133#define sk_refcnt_debug_dec(sk) do { } while (0)
1134#define sk_refcnt_debug_release(sk) do { } while (0)
1135#endif /* SOCK_REFCNT_DEBUG */
1136
1137static inline bool sk_stream_memory_free(const struct sock *sk)
1138{
1139 if (sk->sk_wmem_queued >= sk->sk_sndbuf)
1140 return false;
1141
1142 return sk->sk_prot->stream_memory_free ?
1143 sk->sk_prot->stream_memory_free(sk) : true;
1144}
1145
1146static inline bool sk_stream_is_writeable(const struct sock *sk)
1147{
1148 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1149 sk_stream_memory_free(sk);
1150}
1151
1152static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1153 struct cgroup *ancestor)
1154{
1155#ifdef CONFIG_SOCK_CGROUP_DATA
1156 return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1157 ancestor);
1158#else
1159 return -ENOTSUPP;
1160#endif
1161}
1162
1163static inline bool sk_has_memory_pressure(const struct sock *sk)
1164{
1165 return sk->sk_prot->memory_pressure != NULL;
1166}
1167
1168static inline bool sk_under_memory_pressure(const struct sock *sk)
1169{
1170 if (!sk->sk_prot->memory_pressure)
1171 return false;
1172
1173 if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1174 mem_cgroup_under_socket_pressure(sk->sk_memcg))
1175 return true;
1176
1177 return !!*sk->sk_prot->memory_pressure;
1178}
1179
1180static inline void sk_leave_memory_pressure(struct sock *sk)
1181{
1182 int *memory_pressure = sk->sk_prot->memory_pressure;
1183
1184 if (!memory_pressure)
1185 return;
1186
1187 if (*memory_pressure)
1188 *memory_pressure = 0;
1189}
1190
1191static inline void sk_enter_memory_pressure(struct sock *sk)
1192{
1193 if (!sk->sk_prot->enter_memory_pressure)
1194 return;
1195
1196 sk->sk_prot->enter_memory_pressure(sk);
1197}
1198
1199static inline long
1200sk_memory_allocated(const struct sock *sk)
1201{
1202 return atomic_long_read(sk->sk_prot->memory_allocated);
1203}
1204
1205static inline long
1206sk_memory_allocated_add(struct sock *sk, int amt)
1207{
1208 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1209}
1210
1211static inline void
1212sk_memory_allocated_sub(struct sock *sk, int amt)
1213{
1214 atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1215}
1216
1217static inline void sk_sockets_allocated_dec(struct sock *sk)
1218{
1219 percpu_counter_dec(sk->sk_prot->sockets_allocated);
1220}
1221
1222static inline void sk_sockets_allocated_inc(struct sock *sk)
1223{
1224 percpu_counter_inc(sk->sk_prot->sockets_allocated);
1225}
1226
1227static inline int
1228sk_sockets_allocated_read_positive(struct sock *sk)
1229{
1230 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1231}
1232
1233static inline int
1234proto_sockets_allocated_sum_positive(struct proto *prot)
1235{
1236 return percpu_counter_sum_positive(prot->sockets_allocated);
1237}
1238
1239static inline long
1240proto_memory_allocated(struct proto *prot)
1241{
1242 return atomic_long_read(prot->memory_allocated);
1243}
1244
1245static inline bool
1246proto_memory_pressure(struct proto *prot)
1247{
1248 if (!prot->memory_pressure)
1249 return false;
1250 return !!*prot->memory_pressure;
1251}
1252
1253
1254#ifdef CONFIG_PROC_FS
1255/* Called with local bh disabled */
1256void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1257int sock_prot_inuse_get(struct net *net, struct proto *proto);
1258#else
1259static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1260 int inc)
1261{
1262}
1263#endif
1264
1265
1266/* With per-bucket locks this operation is not-atomic, so that
1267 * this version is not worse.
1268 */
1269static inline int __sk_prot_rehash(struct sock *sk)
1270{
1271 sk->sk_prot->unhash(sk);
1272 return sk->sk_prot->hash(sk);
1273}
1274
1275/* About 10 seconds */
1276#define SOCK_DESTROY_TIME (10*HZ)
1277
1278/* Sockets 0-1023 can't be bound to unless you are superuser */
1279#define PROT_SOCK 1024
1280
1281#define SHUTDOWN_MASK 3
1282#define RCV_SHUTDOWN 1
1283#define SEND_SHUTDOWN 2
1284
1285#define SOCK_SNDBUF_LOCK 1
1286#define SOCK_RCVBUF_LOCK 2
1287#define SOCK_BINDADDR_LOCK 4
1288#define SOCK_BINDPORT_LOCK 8
1289
1290struct socket_alloc {
1291 struct socket socket;
1292 struct inode vfs_inode;
1293};
1294
1295static inline struct socket *SOCKET_I(struct inode *inode)
1296{
1297 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1298}
1299
1300static inline struct inode *SOCK_INODE(struct socket *socket)
1301{
1302 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1303}
1304
1305/*
1306 * Functions for memory accounting
1307 */
1308int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1309int __sk_mem_schedule(struct sock *sk, int size, int kind);
1310void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1311void __sk_mem_reclaim(struct sock *sk, int amount);
1312
1313/* We used to have PAGE_SIZE here, but systems with 64KB pages
1314 * do not necessarily have 16x time more memory than 4KB ones.
1315 */
1316#define SK_MEM_QUANTUM 4096
1317#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1318#define SK_MEM_SEND 0
1319#define SK_MEM_RECV 1
1320
1321/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1322static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1323{
1324 long val = sk->sk_prot->sysctl_mem[index];
1325
1326#if PAGE_SIZE > SK_MEM_QUANTUM
1327 val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1328#elif PAGE_SIZE < SK_MEM_QUANTUM
1329 val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1330#endif
1331 return val;
1332}
1333
1334static inline int sk_mem_pages(int amt)
1335{
1336 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1337}
1338
1339static inline bool sk_has_account(struct sock *sk)
1340{
1341 /* return true if protocol supports memory accounting */
1342 return !!sk->sk_prot->memory_allocated;
1343}
1344
1345static inline bool sk_wmem_schedule(struct sock *sk, int size)
1346{
1347 if (!sk_has_account(sk))
1348 return true;
1349 return size <= sk->sk_forward_alloc ||
1350 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1351}
1352
1353static inline bool
1354sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1355{
1356 if (!sk_has_account(sk))
1357 return true;
1358 return size<= sk->sk_forward_alloc ||
1359 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1360 skb_pfmemalloc(skb);
1361}
1362
1363static inline void sk_mem_reclaim(struct sock *sk)
1364{
1365 if (!sk_has_account(sk))
1366 return;
1367 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1368 __sk_mem_reclaim(sk, sk->sk_forward_alloc);
1369}
1370
1371static inline void sk_mem_reclaim_partial(struct sock *sk)
1372{
1373 if (!sk_has_account(sk))
1374 return;
1375 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1376 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1377}
1378
1379static inline void sk_mem_charge(struct sock *sk, int size)
1380{
1381 if (!sk_has_account(sk))
1382 return;
1383 sk->sk_forward_alloc -= size;
1384}
1385
1386static inline void sk_mem_uncharge(struct sock *sk, int size)
1387{
1388 if (!sk_has_account(sk))
1389 return;
1390 sk->sk_forward_alloc += size;
1391
1392 /* Avoid a possible overflow.
1393 * TCP send queues can make this happen, if sk_mem_reclaim()
1394 * is not called and more than 2 GBytes are released at once.
1395 *
1396 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1397 * no need to hold that much forward allocation anyway.
1398 */
1399 if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1400 __sk_mem_reclaim(sk, 1 << 20);
1401}
1402
1403static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1404{
1405 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1406 sk->sk_wmem_queued -= skb->truesize;
1407 sk_mem_uncharge(sk, skb->truesize);
1408 __kfree_skb(skb);
1409}
1410
1411static inline void sock_release_ownership(struct sock *sk)
1412{
1413 if (sk->sk_lock.owned) {
1414 sk->sk_lock.owned = 0;
1415
1416 /* The sk_lock has mutex_unlock() semantics: */
1417 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1418 }
1419}
1420
1421/*
1422 * Macro so as to not evaluate some arguments when
1423 * lockdep is not enabled.
1424 *
1425 * Mark both the sk_lock and the sk_lock.slock as a
1426 * per-address-family lock class.
1427 */
1428#define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1429do { \
1430 sk->sk_lock.owned = 0; \
1431 init_waitqueue_head(&sk->sk_lock.wq); \
1432 spin_lock_init(&(sk)->sk_lock.slock); \
1433 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1434 sizeof((sk)->sk_lock)); \
1435 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1436 (skey), (sname)); \
1437 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1438} while (0)
1439
1440#ifdef CONFIG_LOCKDEP
1441static inline bool lockdep_sock_is_held(const struct sock *csk)
1442{
1443 struct sock *sk = (struct sock *)csk;
1444
1445 return lockdep_is_held(&sk->sk_lock) ||
1446 lockdep_is_held(&sk->sk_lock.slock);
1447}
1448#endif
1449
1450void lock_sock_nested(struct sock *sk, int subclass);
1451
1452static inline void lock_sock(struct sock *sk)
1453{
1454 lock_sock_nested(sk, 0);
1455}
1456
1457void release_sock(struct sock *sk);
1458
1459/* BH context may only use the following locking interface. */
1460#define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1461#define bh_lock_sock_nested(__sk) \
1462 spin_lock_nested(&((__sk)->sk_lock.slock), \
1463 SINGLE_DEPTH_NESTING)
1464#define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1465
1466bool lock_sock_fast(struct sock *sk);
1467/**
1468 * unlock_sock_fast - complement of lock_sock_fast
1469 * @sk: socket
1470 * @slow: slow mode
1471 *
1472 * fast unlock socket for user context.
1473 * If slow mode is on, we call regular release_sock()
1474 */
1475static inline void unlock_sock_fast(struct sock *sk, bool slow)
1476{
1477 if (slow)
1478 release_sock(sk);
1479 else
1480 spin_unlock_bh(&sk->sk_lock.slock);
1481}
1482
1483/* Used by processes to "lock" a socket state, so that
1484 * interrupts and bottom half handlers won't change it
1485 * from under us. It essentially blocks any incoming
1486 * packets, so that we won't get any new data or any
1487 * packets that change the state of the socket.
1488 *
1489 * While locked, BH processing will add new packets to
1490 * the backlog queue. This queue is processed by the
1491 * owner of the socket lock right before it is released.
1492 *
1493 * Since ~2.3.5 it is also exclusive sleep lock serializing
1494 * accesses from user process context.
1495 */
1496
1497static inline void sock_owned_by_me(const struct sock *sk)
1498{
1499#ifdef CONFIG_LOCKDEP
1500 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1501#endif
1502}
1503
1504static inline bool sock_owned_by_user(const struct sock *sk)
1505{
1506 sock_owned_by_me(sk);
1507 return sk->sk_lock.owned;
1508}
1509
1510/* no reclassification while locks are held */
1511static inline bool sock_allow_reclassification(const struct sock *csk)
1512{
1513 struct sock *sk = (struct sock *)csk;
1514
1515 return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1516}
1517
1518struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1519 struct proto *prot, int kern);
1520void sk_free(struct sock *sk);
1521void sk_destruct(struct sock *sk);
1522struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1523
1524struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1525 gfp_t priority);
1526void __sock_wfree(struct sk_buff *skb);
1527void sock_wfree(struct sk_buff *skb);
1528void skb_orphan_partial(struct sk_buff *skb);
1529void sock_rfree(struct sk_buff *skb);
1530void sock_efree(struct sk_buff *skb);
1531#ifdef CONFIG_INET
1532void sock_edemux(struct sk_buff *skb);
1533#else
1534#define sock_edemux(skb) sock_efree(skb)
1535#endif
1536
1537int sock_setsockopt(struct socket *sock, int level, int op,
1538 char __user *optval, unsigned int optlen);
1539
1540int sock_getsockopt(struct socket *sock, int level, int op,
1541 char __user *optval, int __user *optlen);
1542struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1543 int noblock, int *errcode);
1544struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1545 unsigned long data_len, int noblock,
1546 int *errcode, int max_page_order);
1547void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1548void sock_kfree_s(struct sock *sk, void *mem, int size);
1549void sock_kzfree_s(struct sock *sk, void *mem, int size);
1550void sk_send_sigurg(struct sock *sk);
1551
1552struct sockcm_cookie {
1553 u32 mark;
1554 u16 tsflags;
1555};
1556
1557int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1558 struct sockcm_cookie *sockc);
1559int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1560 struct sockcm_cookie *sockc);
1561
1562/*
1563 * Functions to fill in entries in struct proto_ops when a protocol
1564 * does not implement a particular function.
1565 */
1566int sock_no_bind(struct socket *, struct sockaddr *, int);
1567int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1568int sock_no_socketpair(struct socket *, struct socket *);
1569int sock_no_accept(struct socket *, struct socket *, int);
1570int sock_no_getname(struct socket *, struct sockaddr *, int *, int);
1571unsigned int sock_no_poll(struct file *, struct socket *,
1572 struct poll_table_struct *);
1573int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1574int sock_no_listen(struct socket *, int);
1575int sock_no_shutdown(struct socket *, int);
1576int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1577int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1578int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1579int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1580int sock_no_mmap(struct file *file, struct socket *sock,
1581 struct vm_area_struct *vma);
1582ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1583 size_t size, int flags);
1584
1585/*
1586 * Functions to fill in entries in struct proto_ops when a protocol
1587 * uses the inet style.
1588 */
1589int sock_common_getsockopt(struct socket *sock, int level, int optname,
1590 char __user *optval, int __user *optlen);
1591int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1592 int flags);
1593int sock_common_setsockopt(struct socket *sock, int level, int optname,
1594 char __user *optval, unsigned int optlen);
1595int compat_sock_common_getsockopt(struct socket *sock, int level,
1596 int optname, char __user *optval, int __user *optlen);
1597int compat_sock_common_setsockopt(struct socket *sock, int level,
1598 int optname, char __user *optval, unsigned int optlen);
1599
1600void sk_common_release(struct sock *sk);
1601
1602/*
1603 * Default socket callbacks and setup code
1604 */
1605
1606/* Initialise core socket variables */
1607void sock_init_data(struct socket *sock, struct sock *sk);
1608
1609/*
1610 * Socket reference counting postulates.
1611 *
1612 * * Each user of socket SHOULD hold a reference count.
1613 * * Each access point to socket (an hash table bucket, reference from a list,
1614 * running timer, skb in flight MUST hold a reference count.
1615 * * When reference count hits 0, it means it will never increase back.
1616 * * When reference count hits 0, it means that no references from
1617 * outside exist to this socket and current process on current CPU
1618 * is last user and may/should destroy this socket.
1619 * * sk_free is called from any context: process, BH, IRQ. When
1620 * it is called, socket has no references from outside -> sk_free
1621 * may release descendant resources allocated by the socket, but
1622 * to the time when it is called, socket is NOT referenced by any
1623 * hash tables, lists etc.
1624 * * Packets, delivered from outside (from network or from another process)
1625 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1626 * when they sit in queue. Otherwise, packets will leak to hole, when
1627 * socket is looked up by one cpu and unhasing is made by another CPU.
1628 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1629 * (leak to backlog). Packet socket does all the processing inside
1630 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1631 * use separate SMP lock, so that they are prone too.
1632 */
1633
1634/* Ungrab socket and destroy it, if it was the last reference. */
1635static inline void sock_put(struct sock *sk)
1636{
1637 if (atomic_dec_and_test(&sk->sk_refcnt))
1638 sk_free(sk);
1639}
1640/* Generic version of sock_put(), dealing with all sockets
1641 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1642 */
1643void sock_gen_put(struct sock *sk);
1644
1645int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1646 unsigned int trim_cap, bool refcounted);
1647static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1648 const int nested)
1649{
1650 return __sk_receive_skb(sk, skb, nested, 1, true);
1651}
1652
1653static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1654{
1655 sk->sk_tx_queue_mapping = tx_queue;
1656}
1657
1658static inline void sk_tx_queue_clear(struct sock *sk)
1659{
1660 sk->sk_tx_queue_mapping = -1;
1661}
1662
1663static inline int sk_tx_queue_get(const struct sock *sk)
1664{
1665 return sk ? sk->sk_tx_queue_mapping : -1;
1666}
1667
1668static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1669{
1670 sk_tx_queue_clear(sk);
1671 sk->sk_socket = sock;
1672}
1673
1674static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1675{
1676 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1677 return &rcu_dereference_raw(sk->sk_wq)->wait;
1678}
1679/* Detach socket from process context.
1680 * Announce socket dead, detach it from wait queue and inode.
1681 * Note that parent inode held reference count on this struct sock,
1682 * we do not release it in this function, because protocol
1683 * probably wants some additional cleanups or even continuing
1684 * to work with this socket (TCP).
1685 */
1686static inline void sock_orphan(struct sock *sk)
1687{
1688 write_lock_bh(&sk->sk_callback_lock);
1689 sock_set_flag(sk, SOCK_DEAD);
1690 sk_set_socket(sk, NULL);
1691 sk->sk_wq = NULL;
1692 write_unlock_bh(&sk->sk_callback_lock);
1693}
1694
1695static inline void sock_graft(struct sock *sk, struct socket *parent)
1696{
1697 write_lock_bh(&sk->sk_callback_lock);
1698 sk->sk_wq = parent->wq;
1699 parent->sk = sk;
1700 sk_set_socket(sk, parent);
1701 sk->sk_uid = SOCK_INODE(parent)->i_uid;
1702 security_sock_graft(sk, parent);
1703 write_unlock_bh(&sk->sk_callback_lock);
1704}
1705
1706kuid_t sock_i_uid(struct sock *sk);
1707unsigned long sock_i_ino(struct sock *sk);
1708
1709static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1710{
1711 return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1712}
1713
1714static inline u32 net_tx_rndhash(void)
1715{
1716 u32 v = prandom_u32();
1717
1718 return v ?: 1;
1719}
1720
1721static inline void sk_set_txhash(struct sock *sk)
1722{
1723 sk->sk_txhash = net_tx_rndhash();
1724}
1725
1726static inline void sk_rethink_txhash(struct sock *sk)
1727{
1728 if (sk->sk_txhash)
1729 sk_set_txhash(sk);
1730}
1731
1732static inline struct dst_entry *
1733__sk_dst_get(struct sock *sk)
1734{
1735 return rcu_dereference_check(sk->sk_dst_cache,
1736 lockdep_sock_is_held(sk));
1737}
1738
1739static inline struct dst_entry *
1740sk_dst_get(struct sock *sk)
1741{
1742 struct dst_entry *dst;
1743
1744 rcu_read_lock();
1745 dst = rcu_dereference(sk->sk_dst_cache);
1746 if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1747 dst = NULL;
1748 rcu_read_unlock();
1749 return dst;
1750}
1751
1752static inline void dst_negative_advice(struct sock *sk)
1753{
1754 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1755
1756 sk_rethink_txhash(sk);
1757
1758 if (dst && dst->ops->negative_advice) {
1759 ndst = dst->ops->negative_advice(dst);
1760
1761 if (ndst != dst) {
1762 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1763 sk_tx_queue_clear(sk);
1764 }
1765 }
1766}
1767
1768static inline void
1769__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1770{
1771 struct dst_entry *old_dst;
1772
1773 sk_tx_queue_clear(sk);
1774 /*
1775 * This can be called while sk is owned by the caller only,
1776 * with no state that can be checked in a rcu_dereference_check() cond
1777 */
1778 old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1779 rcu_assign_pointer(sk->sk_dst_cache, dst);
1780 dst_release(old_dst);
1781}
1782
1783static inline void
1784sk_dst_set(struct sock *sk, struct dst_entry *dst)
1785{
1786 struct dst_entry *old_dst;
1787
1788 sk_tx_queue_clear(sk);
1789 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1790 dst_release(old_dst);
1791}
1792
1793static inline void
1794__sk_dst_reset(struct sock *sk)
1795{
1796 __sk_dst_set(sk, NULL);
1797}
1798
1799static inline void
1800sk_dst_reset(struct sock *sk)
1801{
1802 sk_dst_set(sk, NULL);
1803}
1804
1805struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1806
1807struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1808
1809bool sk_mc_loop(struct sock *sk);
1810
1811static inline bool sk_can_gso(const struct sock *sk)
1812{
1813 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1814}
1815
1816void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1817
1818static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1819{
1820 sk->sk_route_nocaps |= flags;
1821 sk->sk_route_caps &= ~flags;
1822}
1823
1824static inline bool sk_check_csum_caps(struct sock *sk)
1825{
1826 return (sk->sk_route_caps & NETIF_F_HW_CSUM) ||
1827 (sk->sk_family == PF_INET &&
1828 (sk->sk_route_caps & NETIF_F_IP_CSUM)) ||
1829 (sk->sk_family == PF_INET6 &&
1830 (sk->sk_route_caps & NETIF_F_IPV6_CSUM));
1831}
1832
1833static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1834 struct iov_iter *from, char *to,
1835 int copy, int offset)
1836{
1837 if (skb->ip_summed == CHECKSUM_NONE) {
1838 __wsum csum = 0;
1839 if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
1840 return -EFAULT;
1841 skb->csum = csum_block_add(skb->csum, csum, offset);
1842 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1843 if (!copy_from_iter_full_nocache(to, copy, from))
1844 return -EFAULT;
1845 } else if (!copy_from_iter_full(to, copy, from))
1846 return -EFAULT;
1847
1848 return 0;
1849}
1850
1851static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1852 struct iov_iter *from, int copy)
1853{
1854 int err, offset = skb->len;
1855
1856 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1857 copy, offset);
1858 if (err)
1859 __skb_trim(skb, offset);
1860
1861 return err;
1862}
1863
1864static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
1865 struct sk_buff *skb,
1866 struct page *page,
1867 int off, int copy)
1868{
1869 int err;
1870
1871 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1872 copy, skb->len);
1873 if (err)
1874 return err;
1875
1876 skb->len += copy;
1877 skb->data_len += copy;
1878 skb->truesize += copy;
1879 sk->sk_wmem_queued += copy;
1880 sk_mem_charge(sk, copy);
1881 return 0;
1882}
1883
1884/**
1885 * sk_wmem_alloc_get - returns write allocations
1886 * @sk: socket
1887 *
1888 * Returns sk_wmem_alloc minus initial offset of one
1889 */
1890static inline int sk_wmem_alloc_get(const struct sock *sk)
1891{
1892 return atomic_read(&sk->sk_wmem_alloc) - 1;
1893}
1894
1895/**
1896 * sk_rmem_alloc_get - returns read allocations
1897 * @sk: socket
1898 *
1899 * Returns sk_rmem_alloc
1900 */
1901static inline int sk_rmem_alloc_get(const struct sock *sk)
1902{
1903 return atomic_read(&sk->sk_rmem_alloc);
1904}
1905
1906/**
1907 * sk_has_allocations - check if allocations are outstanding
1908 * @sk: socket
1909 *
1910 * Returns true if socket has write or read allocations
1911 */
1912static inline bool sk_has_allocations(const struct sock *sk)
1913{
1914 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1915}
1916
1917/**
1918 * skwq_has_sleeper - check if there are any waiting processes
1919 * @wq: struct socket_wq
1920 *
1921 * Returns true if socket_wq has waiting processes
1922 *
1923 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
1924 * barrier call. They were added due to the race found within the tcp code.
1925 *
1926 * Consider following tcp code paths:
1927 *
1928 * CPU1 CPU2
1929 *
1930 * sys_select receive packet
1931 * ... ...
1932 * __add_wait_queue update tp->rcv_nxt
1933 * ... ...
1934 * tp->rcv_nxt check sock_def_readable
1935 * ... {
1936 * schedule rcu_read_lock();
1937 * wq = rcu_dereference(sk->sk_wq);
1938 * if (wq && waitqueue_active(&wq->wait))
1939 * wake_up_interruptible(&wq->wait)
1940 * ...
1941 * }
1942 *
1943 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1944 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
1945 * could then endup calling schedule and sleep forever if there are no more
1946 * data on the socket.
1947 *
1948 */
1949static inline bool skwq_has_sleeper(struct socket_wq *wq)
1950{
1951 return wq && wq_has_sleeper(&wq->wait);
1952}
1953
1954/**
1955 * sock_poll_wait - place memory barrier behind the poll_wait call.
1956 * @filp: file
1957 * @wait_address: socket wait queue
1958 * @p: poll_table
1959 *
1960 * See the comments in the wq_has_sleeper function.
1961 */
1962static inline void sock_poll_wait(struct file *filp,
1963 wait_queue_head_t *wait_address, poll_table *p)
1964{
1965 if (!poll_does_not_wait(p) && wait_address) {
1966 poll_wait(filp, wait_address, p);
1967 /* We need to be sure we are in sync with the
1968 * socket flags modification.
1969 *
1970 * This memory barrier is paired in the wq_has_sleeper.
1971 */
1972 smp_mb();
1973 }
1974}
1975
1976static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
1977{
1978 if (sk->sk_txhash) {
1979 skb->l4_hash = 1;
1980 skb->hash = sk->sk_txhash;
1981 }
1982}
1983
1984void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
1985
1986/*
1987 * Queue a received datagram if it will fit. Stream and sequenced
1988 * protocols can't normally use this as they need to fit buffers in
1989 * and play with them.
1990 *
1991 * Inlined as it's very short and called for pretty much every
1992 * packet ever received.
1993 */
1994static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1995{
1996 skb_orphan(skb);
1997 skb->sk = sk;
1998 skb->destructor = sock_rfree;
1999 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2000 sk_mem_charge(sk, skb->truesize);
2001}
2002
2003void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2004 unsigned long expires);
2005
2006void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2007
2008int __sk_queue_drop_skb(struct sock *sk, struct sk_buff *skb,
2009 unsigned int flags,
2010 void (*destructor)(struct sock *sk,
2011 struct sk_buff *skb));
2012int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2013int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2014
2015int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2016struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2017
2018/*
2019 * Recover an error report and clear atomically
2020 */
2021
2022static inline int sock_error(struct sock *sk)
2023{
2024 int err;
2025 if (likely(!sk->sk_err))
2026 return 0;
2027 err = xchg(&sk->sk_err, 0);
2028 return -err;
2029}
2030
2031static inline unsigned long sock_wspace(struct sock *sk)
2032{
2033 int amt = 0;
2034
2035 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2036 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
2037 if (amt < 0)
2038 amt = 0;
2039 }
2040 return amt;
2041}
2042
2043/* Note:
2044 * We use sk->sk_wq_raw, from contexts knowing this
2045 * pointer is not NULL and cannot disappear/change.
2046 */
2047static inline void sk_set_bit(int nr, struct sock *sk)
2048{
2049 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2050 !sock_flag(sk, SOCK_FASYNC))
2051 return;
2052
2053 set_bit(nr, &sk->sk_wq_raw->flags);
2054}
2055
2056static inline void sk_clear_bit(int nr, struct sock *sk)
2057{
2058 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2059 !sock_flag(sk, SOCK_FASYNC))
2060 return;
2061
2062 clear_bit(nr, &sk->sk_wq_raw->flags);
2063}
2064
2065static inline void sk_wake_async(const struct sock *sk, int how, int band)
2066{
2067 if (sock_flag(sk, SOCK_FASYNC)) {
2068 rcu_read_lock();
2069 sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2070 rcu_read_unlock();
2071 }
2072}
2073
2074/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2075 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2076 * Note: for send buffers, TCP works better if we can build two skbs at
2077 * minimum.
2078 */
2079#define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2080
2081#define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
2082#define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
2083
2084static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2085{
2086 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
2087 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2088 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
2089 }
2090}
2091
2092struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2093 bool force_schedule);
2094
2095/**
2096 * sk_page_frag - return an appropriate page_frag
2097 * @sk: socket
2098 *
2099 * If socket allocation mode allows current thread to sleep, it means its
2100 * safe to use the per task page_frag instead of the per socket one.
2101 */
2102static inline struct page_frag *sk_page_frag(struct sock *sk)
2103{
2104 if (gfpflags_allow_blocking(sk->sk_allocation))
2105 return ¤t->task_frag;
2106
2107 return &sk->sk_frag;
2108}
2109
2110bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2111
2112/*
2113 * Default write policy as shown to user space via poll/select/SIGIO
2114 */
2115static inline bool sock_writeable(const struct sock *sk)
2116{
2117 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2118}
2119
2120static inline gfp_t gfp_any(void)
2121{
2122 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2123}
2124
2125static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2126{
2127 return noblock ? 0 : sk->sk_rcvtimeo;
2128}
2129
2130static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2131{
2132 return noblock ? 0 : sk->sk_sndtimeo;
2133}
2134
2135static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2136{
2137 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2138}
2139
2140/* Alas, with timeout socket operations are not restartable.
2141 * Compare this to poll().
2142 */
2143static inline int sock_intr_errno(long timeo)
2144{
2145 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2146}
2147
2148struct sock_skb_cb {
2149 u32 dropcount;
2150};
2151
2152/* Store sock_skb_cb at the end of skb->cb[] so protocol families
2153 * using skb->cb[] would keep using it directly and utilize its
2154 * alignement guarantee.
2155 */
2156#define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \
2157 sizeof(struct sock_skb_cb)))
2158
2159#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2160 SOCK_SKB_CB_OFFSET))
2161
2162#define sock_skb_cb_check_size(size) \
2163 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2164
2165static inline void
2166sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2167{
2168 SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2169 atomic_read(&sk->sk_drops) : 0;
2170}
2171
2172static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2173{
2174 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2175
2176 atomic_add(segs, &sk->sk_drops);
2177}
2178
2179void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2180 struct sk_buff *skb);
2181void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2182 struct sk_buff *skb);
2183
2184static inline void
2185sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2186{
2187 ktime_t kt = skb->tstamp;
2188 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2189
2190 /*
2191 * generate control messages if
2192 * - receive time stamping in software requested
2193 * - software time stamp available and wanted
2194 * - hardware time stamps available and wanted
2195 */
2196 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2197 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2198 (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2199 (hwtstamps->hwtstamp &&
2200 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2201 __sock_recv_timestamp(msg, sk, skb);
2202 else
2203 sk->sk_stamp = kt;
2204
2205 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2206 __sock_recv_wifi_status(msg, sk, skb);
2207}
2208
2209void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2210 struct sk_buff *skb);
2211
2212static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2213 struct sk_buff *skb)
2214{
2215#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2216 (1UL << SOCK_RCVTSTAMP))
2217#define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \
2218 SOF_TIMESTAMPING_RAW_HARDWARE)
2219
2220 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2221 __sock_recv_ts_and_drops(msg, sk, skb);
2222 else
2223 sk->sk_stamp = skb->tstamp;
2224}
2225
2226void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2227
2228/**
2229 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2230 * @sk: socket sending this packet
2231 * @tsflags: timestamping flags to use
2232 * @tx_flags: completed with instructions for time stamping
2233 *
2234 * Note : callers should take care of initial *tx_flags value (usually 0)
2235 */
2236static inline void sock_tx_timestamp(const struct sock *sk, __u16 tsflags,
2237 __u8 *tx_flags)
2238{
2239 if (unlikely(tsflags))
2240 __sock_tx_timestamp(tsflags, tx_flags);
2241 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2242 *tx_flags |= SKBTX_WIFI_STATUS;
2243}
2244
2245/**
2246 * sk_eat_skb - Release a skb if it is no longer needed
2247 * @sk: socket to eat this skb from
2248 * @skb: socket buffer to eat
2249 *
2250 * This routine must be called with interrupts disabled or with the socket
2251 * locked so that the sk_buff queue operation is ok.
2252*/
2253static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2254{
2255 __skb_unlink(skb, &sk->sk_receive_queue);
2256 __kfree_skb(skb);
2257}
2258
2259static inline
2260struct net *sock_net(const struct sock *sk)
2261{
2262 return read_pnet(&sk->sk_net);
2263}
2264
2265static inline
2266void sock_net_set(struct sock *sk, struct net *net)
2267{
2268 write_pnet(&sk->sk_net, net);
2269}
2270
2271static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2272{
2273 if (skb->sk) {
2274 struct sock *sk = skb->sk;
2275
2276 skb->destructor = NULL;
2277 skb->sk = NULL;
2278 return sk;
2279 }
2280 return NULL;
2281}
2282
2283/* This helper checks if a socket is a full socket,
2284 * ie _not_ a timewait or request socket.
2285 */
2286static inline bool sk_fullsock(const struct sock *sk)
2287{
2288 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2289}
2290
2291/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2292 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2293 */
2294static inline bool sk_listener(const struct sock *sk)
2295{
2296 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2297}
2298
2299/**
2300 * sk_state_load - read sk->sk_state for lockless contexts
2301 * @sk: socket pointer
2302 *
2303 * Paired with sk_state_store(). Used in places we do not hold socket lock :
2304 * tcp_diag_get_info(), tcp_get_info(), tcp_poll(), get_tcp4_sock() ...
2305 */
2306static inline int sk_state_load(const struct sock *sk)
2307{
2308 return smp_load_acquire(&sk->sk_state);
2309}
2310
2311/**
2312 * sk_state_store - update sk->sk_state
2313 * @sk: socket pointer
2314 * @newstate: new state
2315 *
2316 * Paired with sk_state_load(). Should be used in contexts where
2317 * state change might impact lockless readers.
2318 */
2319static inline void sk_state_store(struct sock *sk, int newstate)
2320{
2321 smp_store_release(&sk->sk_state, newstate);
2322}
2323
2324void sock_enable_timestamp(struct sock *sk, int flag);
2325int sock_get_timestamp(struct sock *, struct timeval __user *);
2326int sock_get_timestampns(struct sock *, struct timespec __user *);
2327int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2328 int type);
2329
2330bool sk_ns_capable(const struct sock *sk,
2331 struct user_namespace *user_ns, int cap);
2332bool sk_capable(const struct sock *sk, int cap);
2333bool sk_net_capable(const struct sock *sk, int cap);
2334
2335extern __u32 sysctl_wmem_max;
2336extern __u32 sysctl_rmem_max;
2337
2338extern int sysctl_tstamp_allow_data;
2339extern int sysctl_optmem_max;
2340
2341extern __u32 sysctl_wmem_default;
2342extern __u32 sysctl_rmem_default;
2343
2344#endif /* _SOCK_H */