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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#include <linux/rbtree.h>
64#include <linux/filter.h>
65#include <linux/rculist_nulls.h>
66#include <linux/poll.h>
67
68#include <linux/atomic.h>
69#include <linux/refcount.h>
70#include <net/dst.h>
71#include <net/checksum.h>
72#include <net/tcp_states.h>
73#include <linux/net_tstamp.h>
74#include <net/smc.h>
75#include <net/l3mdev.h>
76
77/*
78 * This structure really needs to be cleaned up.
79 * Most of it is for TCP, and not used by any of
80 * the other protocols.
81 */
82
83/* Define this to get the SOCK_DBG debugging facility. */
84#define SOCK_DEBUGGING
85#ifdef SOCK_DEBUGGING
86#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
87 printk(KERN_DEBUG msg); } while (0)
88#else
89/* Validate arguments and do nothing */
90static inline __printf(2, 3)
91void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
92{
93}
94#endif
95
96/* This is the per-socket lock. The spinlock provides a synchronization
97 * between user contexts and software interrupt processing, whereas the
98 * mini-semaphore synchronizes multiple users amongst themselves.
99 */
100typedef struct {
101 spinlock_t slock;
102 int owned;
103 wait_queue_head_t wq;
104 /*
105 * We express the mutex-alike socket_lock semantics
106 * to the lock validator by explicitly managing
107 * the slock as a lock variant (in addition to
108 * the slock itself):
109 */
110#ifdef CONFIG_DEBUG_LOCK_ALLOC
111 struct lockdep_map dep_map;
112#endif
113} socket_lock_t;
114
115struct sock;
116struct proto;
117struct net;
118
119typedef __u32 __bitwise __portpair;
120typedef __u64 __bitwise __addrpair;
121
122/**
123 * struct sock_common - minimal network layer representation of sockets
124 * @skc_daddr: Foreign IPv4 addr
125 * @skc_rcv_saddr: Bound local IPv4 addr
126 * @skc_hash: hash value used with various protocol lookup tables
127 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
128 * @skc_dport: placeholder for inet_dport/tw_dport
129 * @skc_num: placeholder for inet_num/tw_num
130 * @skc_family: network address family
131 * @skc_state: Connection state
132 * @skc_reuse: %SO_REUSEADDR setting
133 * @skc_reuseport: %SO_REUSEPORT setting
134 * @skc_bound_dev_if: bound device index if != 0
135 * @skc_bind_node: bind hash linkage for various protocol lookup tables
136 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
137 * @skc_prot: protocol handlers inside a network family
138 * @skc_net: reference to the network namespace of this socket
139 * @skc_node: main hash linkage for various protocol lookup tables
140 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
141 * @skc_tx_queue_mapping: tx queue number for this connection
142 * @skc_flags: place holder for sk_flags
143 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
144 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
145 * @skc_incoming_cpu: record/match cpu processing incoming packets
146 * @skc_refcnt: reference count
147 *
148 * This is the minimal network layer representation of sockets, the header
149 * for struct sock and struct inet_timewait_sock.
150 */
151struct sock_common {
152 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
153 * address on 64bit arches : cf INET_MATCH()
154 */
155 union {
156 __addrpair skc_addrpair;
157 struct {
158 __be32 skc_daddr;
159 __be32 skc_rcv_saddr;
160 };
161 };
162 union {
163 unsigned int skc_hash;
164 __u16 skc_u16hashes[2];
165 };
166 /* skc_dport && skc_num must be grouped as well */
167 union {
168 __portpair skc_portpair;
169 struct {
170 __be16 skc_dport;
171 __u16 skc_num;
172 };
173 };
174
175 unsigned short skc_family;
176 volatile unsigned char skc_state;
177 unsigned char skc_reuse:4;
178 unsigned char skc_reuseport:1;
179 unsigned char skc_ipv6only:1;
180 unsigned char skc_net_refcnt:1;
181 int skc_bound_dev_if;
182 union {
183 struct hlist_node skc_bind_node;
184 struct hlist_node skc_portaddr_node;
185 };
186 struct proto *skc_prot;
187 possible_net_t skc_net;
188
189#if IS_ENABLED(CONFIG_IPV6)
190 struct in6_addr skc_v6_daddr;
191 struct in6_addr skc_v6_rcv_saddr;
192#endif
193
194 atomic64_t skc_cookie;
195
196 /* following fields are padding to force
197 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
198 * assuming IPV6 is enabled. We use this padding differently
199 * for different kind of 'sockets'
200 */
201 union {
202 unsigned long skc_flags;
203 struct sock *skc_listener; /* request_sock */
204 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
205 };
206 /*
207 * fields between dontcopy_begin/dontcopy_end
208 * are not copied in sock_copy()
209 */
210 /* private: */
211 int skc_dontcopy_begin[0];
212 /* public: */
213 union {
214 struct hlist_node skc_node;
215 struct hlist_nulls_node skc_nulls_node;
216 };
217 int skc_tx_queue_mapping;
218 union {
219 int skc_incoming_cpu;
220 u32 skc_rcv_wnd;
221 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */
222 };
223
224 refcount_t skc_refcnt;
225 /* private: */
226 int skc_dontcopy_end[0];
227 union {
228 u32 skc_rxhash;
229 u32 skc_window_clamp;
230 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */
231 };
232 /* public: */
233};
234
235/**
236 * struct sock - network layer representation of sockets
237 * @__sk_common: shared layout with inet_timewait_sock
238 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
239 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
240 * @sk_lock: synchronizer
241 * @sk_kern_sock: True if sock is using kernel lock classes
242 * @sk_rcvbuf: size of receive buffer in bytes
243 * @sk_wq: sock wait queue and async head
244 * @sk_rx_dst: receive input route used by early demux
245 * @sk_dst_cache: destination cache
246 * @sk_dst_pending_confirm: need to confirm neighbour
247 * @sk_policy: flow policy
248 * @sk_receive_queue: incoming packets
249 * @sk_wmem_alloc: transmit queue bytes committed
250 * @sk_tsq_flags: TCP Small Queues flags
251 * @sk_write_queue: Packet sending queue
252 * @sk_omem_alloc: "o" is "option" or "other"
253 * @sk_wmem_queued: persistent queue size
254 * @sk_forward_alloc: space allocated forward
255 * @sk_napi_id: id of the last napi context to receive data for sk
256 * @sk_ll_usec: usecs to busypoll when there is no data
257 * @sk_allocation: allocation mode
258 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
259 * @sk_pacing_status: Pacing status (requested, handled by sch_fq)
260 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
261 * @sk_sndbuf: size of send buffer in bytes
262 * @__sk_flags_offset: empty field used to determine location of bitfield
263 * @sk_padding: unused element for alignment
264 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
265 * @sk_no_check_rx: allow zero checksum in RX packets
266 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
267 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
268 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
269 * @sk_gso_max_size: Maximum GSO segment size to build
270 * @sk_gso_max_segs: Maximum number of GSO segments
271 * @sk_pacing_shift: scaling factor for TCP Small Queues
272 * @sk_lingertime: %SO_LINGER l_linger setting
273 * @sk_backlog: always used with the per-socket spinlock held
274 * @sk_callback_lock: used with the callbacks in the end of this struct
275 * @sk_error_queue: rarely used
276 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
277 * IPV6_ADDRFORM for instance)
278 * @sk_err: last error
279 * @sk_err_soft: errors that don't cause failure but are the cause of a
280 * persistent failure not just 'timed out'
281 * @sk_drops: raw/udp drops counter
282 * @sk_ack_backlog: current listen backlog
283 * @sk_max_ack_backlog: listen backlog set in listen()
284 * @sk_uid: user id of owner
285 * @sk_priority: %SO_PRIORITY setting
286 * @sk_type: socket type (%SOCK_STREAM, etc)
287 * @sk_protocol: which protocol this socket belongs in this network family
288 * @sk_peer_pid: &struct pid for this socket's peer
289 * @sk_peer_cred: %SO_PEERCRED setting
290 * @sk_rcvlowat: %SO_RCVLOWAT setting
291 * @sk_rcvtimeo: %SO_RCVTIMEO setting
292 * @sk_sndtimeo: %SO_SNDTIMEO setting
293 * @sk_txhash: computed flow hash for use on transmit
294 * @sk_filter: socket filtering instructions
295 * @sk_timer: sock cleanup timer
296 * @sk_stamp: time stamp of last packet received
297 * @sk_tsflags: SO_TIMESTAMPING socket options
298 * @sk_tskey: counter to disambiguate concurrent tstamp requests
299 * @sk_zckey: counter to order MSG_ZEROCOPY notifications
300 * @sk_socket: Identd and reporting IO signals
301 * @sk_user_data: RPC layer private data
302 * @sk_frag: cached page frag
303 * @sk_peek_off: current peek_offset value
304 * @sk_send_head: front of stuff to transmit
305 * @sk_security: used by security modules
306 * @sk_mark: generic packet mark
307 * @sk_cgrp_data: cgroup data for this cgroup
308 * @sk_memcg: this socket's memory cgroup association
309 * @sk_write_pending: a write to stream socket waits to start
310 * @sk_state_change: callback to indicate change in the state of the sock
311 * @sk_data_ready: callback to indicate there is data to be processed
312 * @sk_write_space: callback to indicate there is bf sending space available
313 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
314 * @sk_backlog_rcv: callback to process the backlog
315 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
316 * @sk_reuseport_cb: reuseport group container
317 * @sk_rcu: used during RCU grace period
318 */
319struct sock {
320 /*
321 * Now struct inet_timewait_sock also uses sock_common, so please just
322 * don't add nothing before this first member (__sk_common) --acme
323 */
324 struct sock_common __sk_common;
325#define sk_node __sk_common.skc_node
326#define sk_nulls_node __sk_common.skc_nulls_node
327#define sk_refcnt __sk_common.skc_refcnt
328#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
329
330#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
331#define sk_dontcopy_end __sk_common.skc_dontcopy_end
332#define sk_hash __sk_common.skc_hash
333#define sk_portpair __sk_common.skc_portpair
334#define sk_num __sk_common.skc_num
335#define sk_dport __sk_common.skc_dport
336#define sk_addrpair __sk_common.skc_addrpair
337#define sk_daddr __sk_common.skc_daddr
338#define sk_rcv_saddr __sk_common.skc_rcv_saddr
339#define sk_family __sk_common.skc_family
340#define sk_state __sk_common.skc_state
341#define sk_reuse __sk_common.skc_reuse
342#define sk_reuseport __sk_common.skc_reuseport
343#define sk_ipv6only __sk_common.skc_ipv6only
344#define sk_net_refcnt __sk_common.skc_net_refcnt
345#define sk_bound_dev_if __sk_common.skc_bound_dev_if
346#define sk_bind_node __sk_common.skc_bind_node
347#define sk_prot __sk_common.skc_prot
348#define sk_net __sk_common.skc_net
349#define sk_v6_daddr __sk_common.skc_v6_daddr
350#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
351#define sk_cookie __sk_common.skc_cookie
352#define sk_incoming_cpu __sk_common.skc_incoming_cpu
353#define sk_flags __sk_common.skc_flags
354#define sk_rxhash __sk_common.skc_rxhash
355
356 socket_lock_t sk_lock;
357 atomic_t sk_drops;
358 int sk_rcvlowat;
359 struct sk_buff_head sk_error_queue;
360 struct sk_buff_head sk_receive_queue;
361 /*
362 * The backlog queue is special, it is always used with
363 * the per-socket spinlock held and requires low latency
364 * access. Therefore we special case it's implementation.
365 * Note : rmem_alloc is in this structure to fill a hole
366 * on 64bit arches, not because its logically part of
367 * backlog.
368 */
369 struct {
370 atomic_t rmem_alloc;
371 int len;
372 struct sk_buff *head;
373 struct sk_buff *tail;
374 } sk_backlog;
375#define sk_rmem_alloc sk_backlog.rmem_alloc
376
377 int sk_forward_alloc;
378#ifdef CONFIG_NET_RX_BUSY_POLL
379 unsigned int sk_ll_usec;
380 /* ===== mostly read cache line ===== */
381 unsigned int sk_napi_id;
382#endif
383 int sk_rcvbuf;
384
385 struct sk_filter __rcu *sk_filter;
386 union {
387 struct socket_wq __rcu *sk_wq;
388 struct socket_wq *sk_wq_raw;
389 };
390#ifdef CONFIG_XFRM
391 struct xfrm_policy __rcu *sk_policy[2];
392#endif
393 struct dst_entry *sk_rx_dst;
394 struct dst_entry __rcu *sk_dst_cache;
395 atomic_t sk_omem_alloc;
396 int sk_sndbuf;
397
398 /* ===== cache line for TX ===== */
399 int sk_wmem_queued;
400 refcount_t sk_wmem_alloc;
401 unsigned long sk_tsq_flags;
402 union {
403 struct sk_buff *sk_send_head;
404 struct rb_root tcp_rtx_queue;
405 };
406 struct sk_buff_head sk_write_queue;
407 __s32 sk_peek_off;
408 int sk_write_pending;
409 __u32 sk_dst_pending_confirm;
410 u32 sk_pacing_status; /* see enum sk_pacing */
411 long sk_sndtimeo;
412 struct timer_list sk_timer;
413 __u32 sk_priority;
414 __u32 sk_mark;
415 u32 sk_pacing_rate; /* bytes per second */
416 u32 sk_max_pacing_rate;
417 struct page_frag sk_frag;
418 netdev_features_t sk_route_caps;
419 netdev_features_t sk_route_nocaps;
420 netdev_features_t sk_route_forced_caps;
421 int sk_gso_type;
422 unsigned int sk_gso_max_size;
423 gfp_t sk_allocation;
424 __u32 sk_txhash;
425
426 /*
427 * Because of non atomicity rules, all
428 * changes are protected by socket lock.
429 */
430 unsigned int __sk_flags_offset[0];
431#ifdef __BIG_ENDIAN_BITFIELD
432#define SK_FL_PROTO_SHIFT 16
433#define SK_FL_PROTO_MASK 0x00ff0000
434
435#define SK_FL_TYPE_SHIFT 0
436#define SK_FL_TYPE_MASK 0x0000ffff
437#else
438#define SK_FL_PROTO_SHIFT 8
439#define SK_FL_PROTO_MASK 0x0000ff00
440
441#define SK_FL_TYPE_SHIFT 16
442#define SK_FL_TYPE_MASK 0xffff0000
443#endif
444
445 unsigned int sk_padding : 1,
446 sk_kern_sock : 1,
447 sk_no_check_tx : 1,
448 sk_no_check_rx : 1,
449 sk_userlocks : 4,
450 sk_protocol : 8,
451 sk_type : 16;
452#define SK_PROTOCOL_MAX U8_MAX
453 u16 sk_gso_max_segs;
454 u8 sk_pacing_shift;
455 unsigned long sk_lingertime;
456 struct proto *sk_prot_creator;
457 rwlock_t sk_callback_lock;
458 int sk_err,
459 sk_err_soft;
460 u32 sk_ack_backlog;
461 u32 sk_max_ack_backlog;
462 kuid_t sk_uid;
463 struct pid *sk_peer_pid;
464 const struct cred *sk_peer_cred;
465 long sk_rcvtimeo;
466 ktime_t sk_stamp;
467 u16 sk_tsflags;
468 u8 sk_shutdown;
469 u32 sk_tskey;
470 atomic_t sk_zckey;
471 struct socket *sk_socket;
472 void *sk_user_data;
473#ifdef CONFIG_SECURITY
474 void *sk_security;
475#endif
476 struct sock_cgroup_data sk_cgrp_data;
477 struct mem_cgroup *sk_memcg;
478 void (*sk_state_change)(struct sock *sk);
479 void (*sk_data_ready)(struct sock *sk);
480 void (*sk_write_space)(struct sock *sk);
481 void (*sk_error_report)(struct sock *sk);
482 int (*sk_backlog_rcv)(struct sock *sk,
483 struct sk_buff *skb);
484 void (*sk_destruct)(struct sock *sk);
485 struct sock_reuseport __rcu *sk_reuseport_cb;
486 struct rcu_head sk_rcu;
487};
488
489enum sk_pacing {
490 SK_PACING_NONE = 0,
491 SK_PACING_NEEDED = 1,
492 SK_PACING_FQ = 2,
493};
494
495#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
496
497#define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk)))
498#define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr)
499
500/*
501 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
502 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
503 * on a socket means that the socket will reuse everybody else's port
504 * without looking at the other's sk_reuse value.
505 */
506
507#define SK_NO_REUSE 0
508#define SK_CAN_REUSE 1
509#define SK_FORCE_REUSE 2
510
511int sk_set_peek_off(struct sock *sk, int val);
512
513static inline int sk_peek_offset(struct sock *sk, int flags)
514{
515 if (unlikely(flags & MSG_PEEK)) {
516 return READ_ONCE(sk->sk_peek_off);
517 }
518
519 return 0;
520}
521
522static inline void sk_peek_offset_bwd(struct sock *sk, int val)
523{
524 s32 off = READ_ONCE(sk->sk_peek_off);
525
526 if (unlikely(off >= 0)) {
527 off = max_t(s32, off - val, 0);
528 WRITE_ONCE(sk->sk_peek_off, off);
529 }
530}
531
532static inline void sk_peek_offset_fwd(struct sock *sk, int val)
533{
534 sk_peek_offset_bwd(sk, -val);
535}
536
537/*
538 * Hashed lists helper routines
539 */
540static inline struct sock *sk_entry(const struct hlist_node *node)
541{
542 return hlist_entry(node, struct sock, sk_node);
543}
544
545static inline struct sock *__sk_head(const struct hlist_head *head)
546{
547 return hlist_entry(head->first, struct sock, sk_node);
548}
549
550static inline struct sock *sk_head(const struct hlist_head *head)
551{
552 return hlist_empty(head) ? NULL : __sk_head(head);
553}
554
555static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
556{
557 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
558}
559
560static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
561{
562 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
563}
564
565static inline struct sock *sk_next(const struct sock *sk)
566{
567 return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
568}
569
570static inline struct sock *sk_nulls_next(const struct sock *sk)
571{
572 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
573 hlist_nulls_entry(sk->sk_nulls_node.next,
574 struct sock, sk_nulls_node) :
575 NULL;
576}
577
578static inline bool sk_unhashed(const struct sock *sk)
579{
580 return hlist_unhashed(&sk->sk_node);
581}
582
583static inline bool sk_hashed(const struct sock *sk)
584{
585 return !sk_unhashed(sk);
586}
587
588static inline void sk_node_init(struct hlist_node *node)
589{
590 node->pprev = NULL;
591}
592
593static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
594{
595 node->pprev = NULL;
596}
597
598static inline void __sk_del_node(struct sock *sk)
599{
600 __hlist_del(&sk->sk_node);
601}
602
603/* NB: equivalent to hlist_del_init_rcu */
604static inline bool __sk_del_node_init(struct sock *sk)
605{
606 if (sk_hashed(sk)) {
607 __sk_del_node(sk);
608 sk_node_init(&sk->sk_node);
609 return true;
610 }
611 return false;
612}
613
614/* Grab socket reference count. This operation is valid only
615 when sk is ALREADY grabbed f.e. it is found in hash table
616 or a list and the lookup is made under lock preventing hash table
617 modifications.
618 */
619
620static __always_inline void sock_hold(struct sock *sk)
621{
622 refcount_inc(&sk->sk_refcnt);
623}
624
625/* Ungrab socket in the context, which assumes that socket refcnt
626 cannot hit zero, f.e. it is true in context of any socketcall.
627 */
628static __always_inline void __sock_put(struct sock *sk)
629{
630 refcount_dec(&sk->sk_refcnt);
631}
632
633static inline bool sk_del_node_init(struct sock *sk)
634{
635 bool rc = __sk_del_node_init(sk);
636
637 if (rc) {
638 /* paranoid for a while -acme */
639 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
640 __sock_put(sk);
641 }
642 return rc;
643}
644#define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
645
646static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
647{
648 if (sk_hashed(sk)) {
649 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
650 return true;
651 }
652 return false;
653}
654
655static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
656{
657 bool rc = __sk_nulls_del_node_init_rcu(sk);
658
659 if (rc) {
660 /* paranoid for a while -acme */
661 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
662 __sock_put(sk);
663 }
664 return rc;
665}
666
667static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
668{
669 hlist_add_head(&sk->sk_node, list);
670}
671
672static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
673{
674 sock_hold(sk);
675 __sk_add_node(sk, list);
676}
677
678static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
679{
680 sock_hold(sk);
681 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
682 sk->sk_family == AF_INET6)
683 hlist_add_tail_rcu(&sk->sk_node, list);
684 else
685 hlist_add_head_rcu(&sk->sk_node, list);
686}
687
688static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
689{
690 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
691}
692
693static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
694{
695 sock_hold(sk);
696 __sk_nulls_add_node_rcu(sk, list);
697}
698
699static inline void __sk_del_bind_node(struct sock *sk)
700{
701 __hlist_del(&sk->sk_bind_node);
702}
703
704static inline void sk_add_bind_node(struct sock *sk,
705 struct hlist_head *list)
706{
707 hlist_add_head(&sk->sk_bind_node, list);
708}
709
710#define sk_for_each(__sk, list) \
711 hlist_for_each_entry(__sk, list, sk_node)
712#define sk_for_each_rcu(__sk, list) \
713 hlist_for_each_entry_rcu(__sk, list, sk_node)
714#define sk_nulls_for_each(__sk, node, list) \
715 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
716#define sk_nulls_for_each_rcu(__sk, node, list) \
717 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
718#define sk_for_each_from(__sk) \
719 hlist_for_each_entry_from(__sk, sk_node)
720#define sk_nulls_for_each_from(__sk, node) \
721 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
722 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
723#define sk_for_each_safe(__sk, tmp, list) \
724 hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
725#define sk_for_each_bound(__sk, list) \
726 hlist_for_each_entry(__sk, list, sk_bind_node)
727
728/**
729 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
730 * @tpos: the type * to use as a loop cursor.
731 * @pos: the &struct hlist_node to use as a loop cursor.
732 * @head: the head for your list.
733 * @offset: offset of hlist_node within the struct.
734 *
735 */
736#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \
737 for (pos = rcu_dereference(hlist_first_rcu(head)); \
738 pos != NULL && \
739 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \
740 pos = rcu_dereference(hlist_next_rcu(pos)))
741
742static inline struct user_namespace *sk_user_ns(struct sock *sk)
743{
744 /* Careful only use this in a context where these parameters
745 * can not change and must all be valid, such as recvmsg from
746 * userspace.
747 */
748 return sk->sk_socket->file->f_cred->user_ns;
749}
750
751/* Sock flags */
752enum sock_flags {
753 SOCK_DEAD,
754 SOCK_DONE,
755 SOCK_URGINLINE,
756 SOCK_KEEPOPEN,
757 SOCK_LINGER,
758 SOCK_DESTROY,
759 SOCK_BROADCAST,
760 SOCK_TIMESTAMP,
761 SOCK_ZAPPED,
762 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
763 SOCK_DBG, /* %SO_DEBUG setting */
764 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
765 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
766 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
767 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
768 SOCK_MEMALLOC, /* VM depends on this socket for swapping */
769 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
770 SOCK_FASYNC, /* fasync() active */
771 SOCK_RXQ_OVFL,
772 SOCK_ZEROCOPY, /* buffers from userspace */
773 SOCK_WIFI_STATUS, /* push wifi status to userspace */
774 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
775 * Will use last 4 bytes of packet sent from
776 * user-space instead.
777 */
778 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
779 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
780 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
781};
782
783#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
784
785static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
786{
787 nsk->sk_flags = osk->sk_flags;
788}
789
790static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
791{
792 __set_bit(flag, &sk->sk_flags);
793}
794
795static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
796{
797 __clear_bit(flag, &sk->sk_flags);
798}
799
800static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
801{
802 return test_bit(flag, &sk->sk_flags);
803}
804
805#ifdef CONFIG_NET
806extern struct static_key memalloc_socks;
807static inline int sk_memalloc_socks(void)
808{
809 return static_key_false(&memalloc_socks);
810}
811#else
812
813static inline int sk_memalloc_socks(void)
814{
815 return 0;
816}
817
818#endif
819
820static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
821{
822 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
823}
824
825static inline void sk_acceptq_removed(struct sock *sk)
826{
827 sk->sk_ack_backlog--;
828}
829
830static inline void sk_acceptq_added(struct sock *sk)
831{
832 sk->sk_ack_backlog++;
833}
834
835static inline bool sk_acceptq_is_full(const struct sock *sk)
836{
837 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
838}
839
840/*
841 * Compute minimal free write space needed to queue new packets.
842 */
843static inline int sk_stream_min_wspace(const struct sock *sk)
844{
845 return sk->sk_wmem_queued >> 1;
846}
847
848static inline int sk_stream_wspace(const struct sock *sk)
849{
850 return sk->sk_sndbuf - sk->sk_wmem_queued;
851}
852
853void sk_stream_write_space(struct sock *sk);
854
855/* OOB backlog add */
856static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
857{
858 /* dont let skb dst not refcounted, we are going to leave rcu lock */
859 skb_dst_force(skb);
860
861 if (!sk->sk_backlog.tail)
862 sk->sk_backlog.head = skb;
863 else
864 sk->sk_backlog.tail->next = skb;
865
866 sk->sk_backlog.tail = skb;
867 skb->next = NULL;
868}
869
870/*
871 * Take into account size of receive queue and backlog queue
872 * Do not take into account this skb truesize,
873 * to allow even a single big packet to come.
874 */
875static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
876{
877 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
878
879 return qsize > limit;
880}
881
882/* The per-socket spinlock must be held here. */
883static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
884 unsigned int limit)
885{
886 if (sk_rcvqueues_full(sk, limit))
887 return -ENOBUFS;
888
889 /*
890 * If the skb was allocated from pfmemalloc reserves, only
891 * allow SOCK_MEMALLOC sockets to use it as this socket is
892 * helping free memory
893 */
894 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
895 return -ENOMEM;
896
897 __sk_add_backlog(sk, skb);
898 sk->sk_backlog.len += skb->truesize;
899 return 0;
900}
901
902int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
903
904static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
905{
906 if (sk_memalloc_socks() && skb_pfmemalloc(skb))
907 return __sk_backlog_rcv(sk, skb);
908
909 return sk->sk_backlog_rcv(sk, skb);
910}
911
912static inline void sk_incoming_cpu_update(struct sock *sk)
913{
914 int cpu = raw_smp_processor_id();
915
916 if (unlikely(sk->sk_incoming_cpu != cpu))
917 sk->sk_incoming_cpu = cpu;
918}
919
920static inline void sock_rps_record_flow_hash(__u32 hash)
921{
922#ifdef CONFIG_RPS
923 struct rps_sock_flow_table *sock_flow_table;
924
925 rcu_read_lock();
926 sock_flow_table = rcu_dereference(rps_sock_flow_table);
927 rps_record_sock_flow(sock_flow_table, hash);
928 rcu_read_unlock();
929#endif
930}
931
932static inline void sock_rps_record_flow(const struct sock *sk)
933{
934#ifdef CONFIG_RPS
935 if (static_key_false(&rfs_needed)) {
936 /* Reading sk->sk_rxhash might incur an expensive cache line
937 * miss.
938 *
939 * TCP_ESTABLISHED does cover almost all states where RFS
940 * might be useful, and is cheaper [1] than testing :
941 * IPv4: inet_sk(sk)->inet_daddr
942 * IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
943 * OR an additional socket flag
944 * [1] : sk_state and sk_prot are in the same cache line.
945 */
946 if (sk->sk_state == TCP_ESTABLISHED)
947 sock_rps_record_flow_hash(sk->sk_rxhash);
948 }
949#endif
950}
951
952static inline void sock_rps_save_rxhash(struct sock *sk,
953 const struct sk_buff *skb)
954{
955#ifdef CONFIG_RPS
956 if (unlikely(sk->sk_rxhash != skb->hash))
957 sk->sk_rxhash = skb->hash;
958#endif
959}
960
961static inline void sock_rps_reset_rxhash(struct sock *sk)
962{
963#ifdef CONFIG_RPS
964 sk->sk_rxhash = 0;
965#endif
966}
967
968#define sk_wait_event(__sk, __timeo, __condition, __wait) \
969 ({ int __rc; \
970 release_sock(__sk); \
971 __rc = __condition; \
972 if (!__rc) { \
973 *(__timeo) = wait_woken(__wait, \
974 TASK_INTERRUPTIBLE, \
975 *(__timeo)); \
976 } \
977 sched_annotate_sleep(); \
978 lock_sock(__sk); \
979 __rc = __condition; \
980 __rc; \
981 })
982
983int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
984int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
985void sk_stream_wait_close(struct sock *sk, long timeo_p);
986int sk_stream_error(struct sock *sk, int flags, int err);
987void sk_stream_kill_queues(struct sock *sk);
988void sk_set_memalloc(struct sock *sk);
989void sk_clear_memalloc(struct sock *sk);
990
991void __sk_flush_backlog(struct sock *sk);
992
993static inline bool sk_flush_backlog(struct sock *sk)
994{
995 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
996 __sk_flush_backlog(sk);
997 return true;
998 }
999 return false;
1000}
1001
1002int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1003
1004struct request_sock_ops;
1005struct timewait_sock_ops;
1006struct inet_hashinfo;
1007struct raw_hashinfo;
1008struct smc_hashinfo;
1009struct module;
1010
1011/*
1012 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1013 * un-modified. Special care is taken when initializing object to zero.
1014 */
1015static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1016{
1017 if (offsetof(struct sock, sk_node.next) != 0)
1018 memset(sk, 0, offsetof(struct sock, sk_node.next));
1019 memset(&sk->sk_node.pprev, 0,
1020 size - offsetof(struct sock, sk_node.pprev));
1021}
1022
1023/* Networking protocol blocks we attach to sockets.
1024 * socket layer -> transport layer interface
1025 */
1026struct proto {
1027 void (*close)(struct sock *sk,
1028 long timeout);
1029 int (*pre_connect)(struct sock *sk,
1030 struct sockaddr *uaddr,
1031 int addr_len);
1032 int (*connect)(struct sock *sk,
1033 struct sockaddr *uaddr,
1034 int addr_len);
1035 int (*disconnect)(struct sock *sk, int flags);
1036
1037 struct sock * (*accept)(struct sock *sk, int flags, int *err,
1038 bool kern);
1039
1040 int (*ioctl)(struct sock *sk, int cmd,
1041 unsigned long arg);
1042 int (*init)(struct sock *sk);
1043 void (*destroy)(struct sock *sk);
1044 void (*shutdown)(struct sock *sk, int how);
1045 int (*setsockopt)(struct sock *sk, int level,
1046 int optname, char __user *optval,
1047 unsigned int optlen);
1048 int (*getsockopt)(struct sock *sk, int level,
1049 int optname, char __user *optval,
1050 int __user *option);
1051 void (*keepalive)(struct sock *sk, int valbool);
1052#ifdef CONFIG_COMPAT
1053 int (*compat_setsockopt)(struct sock *sk,
1054 int level,
1055 int optname, char __user *optval,
1056 unsigned int optlen);
1057 int (*compat_getsockopt)(struct sock *sk,
1058 int level,
1059 int optname, char __user *optval,
1060 int __user *option);
1061 int (*compat_ioctl)(struct sock *sk,
1062 unsigned int cmd, unsigned long arg);
1063#endif
1064 int (*sendmsg)(struct sock *sk, struct msghdr *msg,
1065 size_t len);
1066 int (*recvmsg)(struct sock *sk, struct msghdr *msg,
1067 size_t len, int noblock, int flags,
1068 int *addr_len);
1069 int (*sendpage)(struct sock *sk, struct page *page,
1070 int offset, size_t size, int flags);
1071 int (*bind)(struct sock *sk,
1072 struct sockaddr *uaddr, int addr_len);
1073
1074 int (*backlog_rcv) (struct sock *sk,
1075 struct sk_buff *skb);
1076
1077 void (*release_cb)(struct sock *sk);
1078
1079 /* Keeping track of sk's, looking them up, and port selection methods. */
1080 int (*hash)(struct sock *sk);
1081 void (*unhash)(struct sock *sk);
1082 void (*rehash)(struct sock *sk);
1083 int (*get_port)(struct sock *sk, unsigned short snum);
1084
1085 /* Keeping track of sockets in use */
1086#ifdef CONFIG_PROC_FS
1087 unsigned int inuse_idx;
1088#endif
1089
1090 bool (*stream_memory_free)(const struct sock *sk);
1091 bool (*stream_memory_read)(const struct sock *sk);
1092 /* Memory pressure */
1093 void (*enter_memory_pressure)(struct sock *sk);
1094 void (*leave_memory_pressure)(struct sock *sk);
1095 atomic_long_t *memory_allocated; /* Current allocated memory. */
1096 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
1097 /*
1098 * Pressure flag: try to collapse.
1099 * Technical note: it is used by multiple contexts non atomically.
1100 * All the __sk_mem_schedule() is of this nature: accounting
1101 * is strict, actions are advisory and have some latency.
1102 */
1103 unsigned long *memory_pressure;
1104 long *sysctl_mem;
1105
1106 int *sysctl_wmem;
1107 int *sysctl_rmem;
1108 u32 sysctl_wmem_offset;
1109 u32 sysctl_rmem_offset;
1110
1111 int max_header;
1112 bool no_autobind;
1113
1114 struct kmem_cache *slab;
1115 unsigned int obj_size;
1116 slab_flags_t slab_flags;
1117 unsigned int useroffset; /* Usercopy region offset */
1118 unsigned int usersize; /* Usercopy region size */
1119
1120 struct percpu_counter *orphan_count;
1121
1122 struct request_sock_ops *rsk_prot;
1123 struct timewait_sock_ops *twsk_prot;
1124
1125 union {
1126 struct inet_hashinfo *hashinfo;
1127 struct udp_table *udp_table;
1128 struct raw_hashinfo *raw_hash;
1129 struct smc_hashinfo *smc_hash;
1130 } h;
1131
1132 struct module *owner;
1133
1134 char name[32];
1135
1136 struct list_head node;
1137#ifdef SOCK_REFCNT_DEBUG
1138 atomic_t socks;
1139#endif
1140 int (*diag_destroy)(struct sock *sk, int err);
1141} __randomize_layout;
1142
1143int proto_register(struct proto *prot, int alloc_slab);
1144void proto_unregister(struct proto *prot);
1145int sock_load_diag_module(int family, int protocol);
1146
1147#ifdef SOCK_REFCNT_DEBUG
1148static inline void sk_refcnt_debug_inc(struct sock *sk)
1149{
1150 atomic_inc(&sk->sk_prot->socks);
1151}
1152
1153static inline void sk_refcnt_debug_dec(struct sock *sk)
1154{
1155 atomic_dec(&sk->sk_prot->socks);
1156 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1157 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1158}
1159
1160static inline void sk_refcnt_debug_release(const struct sock *sk)
1161{
1162 if (refcount_read(&sk->sk_refcnt) != 1)
1163 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1164 sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1165}
1166#else /* SOCK_REFCNT_DEBUG */
1167#define sk_refcnt_debug_inc(sk) do { } while (0)
1168#define sk_refcnt_debug_dec(sk) do { } while (0)
1169#define sk_refcnt_debug_release(sk) do { } while (0)
1170#endif /* SOCK_REFCNT_DEBUG */
1171
1172static inline bool sk_stream_memory_free(const struct sock *sk)
1173{
1174 if (sk->sk_wmem_queued >= sk->sk_sndbuf)
1175 return false;
1176
1177 return sk->sk_prot->stream_memory_free ?
1178 sk->sk_prot->stream_memory_free(sk) : true;
1179}
1180
1181static inline bool sk_stream_is_writeable(const struct sock *sk)
1182{
1183 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1184 sk_stream_memory_free(sk);
1185}
1186
1187static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1188 struct cgroup *ancestor)
1189{
1190#ifdef CONFIG_SOCK_CGROUP_DATA
1191 return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1192 ancestor);
1193#else
1194 return -ENOTSUPP;
1195#endif
1196}
1197
1198static inline bool sk_has_memory_pressure(const struct sock *sk)
1199{
1200 return sk->sk_prot->memory_pressure != NULL;
1201}
1202
1203static inline bool sk_under_memory_pressure(const struct sock *sk)
1204{
1205 if (!sk->sk_prot->memory_pressure)
1206 return false;
1207
1208 if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1209 mem_cgroup_under_socket_pressure(sk->sk_memcg))
1210 return true;
1211
1212 return !!*sk->sk_prot->memory_pressure;
1213}
1214
1215static inline long
1216sk_memory_allocated(const struct sock *sk)
1217{
1218 return atomic_long_read(sk->sk_prot->memory_allocated);
1219}
1220
1221static inline long
1222sk_memory_allocated_add(struct sock *sk, int amt)
1223{
1224 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1225}
1226
1227static inline void
1228sk_memory_allocated_sub(struct sock *sk, int amt)
1229{
1230 atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1231}
1232
1233static inline void sk_sockets_allocated_dec(struct sock *sk)
1234{
1235 percpu_counter_dec(sk->sk_prot->sockets_allocated);
1236}
1237
1238static inline void sk_sockets_allocated_inc(struct sock *sk)
1239{
1240 percpu_counter_inc(sk->sk_prot->sockets_allocated);
1241}
1242
1243static inline int
1244sk_sockets_allocated_read_positive(struct sock *sk)
1245{
1246 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1247}
1248
1249static inline int
1250proto_sockets_allocated_sum_positive(struct proto *prot)
1251{
1252 return percpu_counter_sum_positive(prot->sockets_allocated);
1253}
1254
1255static inline long
1256proto_memory_allocated(struct proto *prot)
1257{
1258 return atomic_long_read(prot->memory_allocated);
1259}
1260
1261static inline bool
1262proto_memory_pressure(struct proto *prot)
1263{
1264 if (!prot->memory_pressure)
1265 return false;
1266 return !!*prot->memory_pressure;
1267}
1268
1269
1270#ifdef CONFIG_PROC_FS
1271/* Called with local bh disabled */
1272void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1273int sock_prot_inuse_get(struct net *net, struct proto *proto);
1274int sock_inuse_get(struct net *net);
1275#else
1276static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1277 int inc)
1278{
1279}
1280#endif
1281
1282
1283/* With per-bucket locks this operation is not-atomic, so that
1284 * this version is not worse.
1285 */
1286static inline int __sk_prot_rehash(struct sock *sk)
1287{
1288 sk->sk_prot->unhash(sk);
1289 return sk->sk_prot->hash(sk);
1290}
1291
1292/* About 10 seconds */
1293#define SOCK_DESTROY_TIME (10*HZ)
1294
1295/* Sockets 0-1023 can't be bound to unless you are superuser */
1296#define PROT_SOCK 1024
1297
1298#define SHUTDOWN_MASK 3
1299#define RCV_SHUTDOWN 1
1300#define SEND_SHUTDOWN 2
1301
1302#define SOCK_SNDBUF_LOCK 1
1303#define SOCK_RCVBUF_LOCK 2
1304#define SOCK_BINDADDR_LOCK 4
1305#define SOCK_BINDPORT_LOCK 8
1306
1307struct socket_alloc {
1308 struct socket socket;
1309 struct inode vfs_inode;
1310};
1311
1312static inline struct socket *SOCKET_I(struct inode *inode)
1313{
1314 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1315}
1316
1317static inline struct inode *SOCK_INODE(struct socket *socket)
1318{
1319 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1320}
1321
1322/*
1323 * Functions for memory accounting
1324 */
1325int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1326int __sk_mem_schedule(struct sock *sk, int size, int kind);
1327void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1328void __sk_mem_reclaim(struct sock *sk, int amount);
1329
1330/* We used to have PAGE_SIZE here, but systems with 64KB pages
1331 * do not necessarily have 16x time more memory than 4KB ones.
1332 */
1333#define SK_MEM_QUANTUM 4096
1334#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1335#define SK_MEM_SEND 0
1336#define SK_MEM_RECV 1
1337
1338/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1339static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1340{
1341 long val = sk->sk_prot->sysctl_mem[index];
1342
1343#if PAGE_SIZE > SK_MEM_QUANTUM
1344 val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1345#elif PAGE_SIZE < SK_MEM_QUANTUM
1346 val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1347#endif
1348 return val;
1349}
1350
1351static inline int sk_mem_pages(int amt)
1352{
1353 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1354}
1355
1356static inline bool sk_has_account(struct sock *sk)
1357{
1358 /* return true if protocol supports memory accounting */
1359 return !!sk->sk_prot->memory_allocated;
1360}
1361
1362static inline bool sk_wmem_schedule(struct sock *sk, int size)
1363{
1364 if (!sk_has_account(sk))
1365 return true;
1366 return size <= sk->sk_forward_alloc ||
1367 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1368}
1369
1370static inline bool
1371sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1372{
1373 if (!sk_has_account(sk))
1374 return true;
1375 return size<= sk->sk_forward_alloc ||
1376 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1377 skb_pfmemalloc(skb);
1378}
1379
1380static inline void sk_mem_reclaim(struct sock *sk)
1381{
1382 if (!sk_has_account(sk))
1383 return;
1384 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1385 __sk_mem_reclaim(sk, sk->sk_forward_alloc);
1386}
1387
1388static inline void sk_mem_reclaim_partial(struct sock *sk)
1389{
1390 if (!sk_has_account(sk))
1391 return;
1392 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1393 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1394}
1395
1396static inline void sk_mem_charge(struct sock *sk, int size)
1397{
1398 if (!sk_has_account(sk))
1399 return;
1400 sk->sk_forward_alloc -= size;
1401}
1402
1403static inline void sk_mem_uncharge(struct sock *sk, int size)
1404{
1405 if (!sk_has_account(sk))
1406 return;
1407 sk->sk_forward_alloc += size;
1408
1409 /* Avoid a possible overflow.
1410 * TCP send queues can make this happen, if sk_mem_reclaim()
1411 * is not called and more than 2 GBytes are released at once.
1412 *
1413 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1414 * no need to hold that much forward allocation anyway.
1415 */
1416 if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1417 __sk_mem_reclaim(sk, 1 << 20);
1418}
1419
1420static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1421{
1422 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1423 sk->sk_wmem_queued -= skb->truesize;
1424 sk_mem_uncharge(sk, skb->truesize);
1425 __kfree_skb(skb);
1426}
1427
1428static inline void sock_release_ownership(struct sock *sk)
1429{
1430 if (sk->sk_lock.owned) {
1431 sk->sk_lock.owned = 0;
1432
1433 /* The sk_lock has mutex_unlock() semantics: */
1434 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1435 }
1436}
1437
1438/*
1439 * Macro so as to not evaluate some arguments when
1440 * lockdep is not enabled.
1441 *
1442 * Mark both the sk_lock and the sk_lock.slock as a
1443 * per-address-family lock class.
1444 */
1445#define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1446do { \
1447 sk->sk_lock.owned = 0; \
1448 init_waitqueue_head(&sk->sk_lock.wq); \
1449 spin_lock_init(&(sk)->sk_lock.slock); \
1450 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1451 sizeof((sk)->sk_lock)); \
1452 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1453 (skey), (sname)); \
1454 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1455} while (0)
1456
1457#ifdef CONFIG_LOCKDEP
1458static inline bool lockdep_sock_is_held(const struct sock *sk)
1459{
1460 return lockdep_is_held(&sk->sk_lock) ||
1461 lockdep_is_held(&sk->sk_lock.slock);
1462}
1463#endif
1464
1465void lock_sock_nested(struct sock *sk, int subclass);
1466
1467static inline void lock_sock(struct sock *sk)
1468{
1469 lock_sock_nested(sk, 0);
1470}
1471
1472void release_sock(struct sock *sk);
1473
1474/* BH context may only use the following locking interface. */
1475#define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1476#define bh_lock_sock_nested(__sk) \
1477 spin_lock_nested(&((__sk)->sk_lock.slock), \
1478 SINGLE_DEPTH_NESTING)
1479#define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1480
1481bool lock_sock_fast(struct sock *sk);
1482/**
1483 * unlock_sock_fast - complement of lock_sock_fast
1484 * @sk: socket
1485 * @slow: slow mode
1486 *
1487 * fast unlock socket for user context.
1488 * If slow mode is on, we call regular release_sock()
1489 */
1490static inline void unlock_sock_fast(struct sock *sk, bool slow)
1491{
1492 if (slow)
1493 release_sock(sk);
1494 else
1495 spin_unlock_bh(&sk->sk_lock.slock);
1496}
1497
1498/* Used by processes to "lock" a socket state, so that
1499 * interrupts and bottom half handlers won't change it
1500 * from under us. It essentially blocks any incoming
1501 * packets, so that we won't get any new data or any
1502 * packets that change the state of the socket.
1503 *
1504 * While locked, BH processing will add new packets to
1505 * the backlog queue. This queue is processed by the
1506 * owner of the socket lock right before it is released.
1507 *
1508 * Since ~2.3.5 it is also exclusive sleep lock serializing
1509 * accesses from user process context.
1510 */
1511
1512static inline void sock_owned_by_me(const struct sock *sk)
1513{
1514#ifdef CONFIG_LOCKDEP
1515 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1516#endif
1517}
1518
1519static inline bool sock_owned_by_user(const struct sock *sk)
1520{
1521 sock_owned_by_me(sk);
1522 return sk->sk_lock.owned;
1523}
1524
1525static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1526{
1527 return sk->sk_lock.owned;
1528}
1529
1530/* no reclassification while locks are held */
1531static inline bool sock_allow_reclassification(const struct sock *csk)
1532{
1533 struct sock *sk = (struct sock *)csk;
1534
1535 return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1536}
1537
1538struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1539 struct proto *prot, int kern);
1540void sk_free(struct sock *sk);
1541void sk_destruct(struct sock *sk);
1542struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1543void sk_free_unlock_clone(struct sock *sk);
1544
1545struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1546 gfp_t priority);
1547void __sock_wfree(struct sk_buff *skb);
1548void sock_wfree(struct sk_buff *skb);
1549struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1550 gfp_t priority);
1551void skb_orphan_partial(struct sk_buff *skb);
1552void sock_rfree(struct sk_buff *skb);
1553void sock_efree(struct sk_buff *skb);
1554#ifdef CONFIG_INET
1555void sock_edemux(struct sk_buff *skb);
1556#else
1557#define sock_edemux sock_efree
1558#endif
1559
1560int sock_setsockopt(struct socket *sock, int level, int op,
1561 char __user *optval, unsigned int optlen);
1562
1563int sock_getsockopt(struct socket *sock, int level, int op,
1564 char __user *optval, int __user *optlen);
1565struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1566 int noblock, int *errcode);
1567struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1568 unsigned long data_len, int noblock,
1569 int *errcode, int max_page_order);
1570void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1571void sock_kfree_s(struct sock *sk, void *mem, int size);
1572void sock_kzfree_s(struct sock *sk, void *mem, int size);
1573void sk_send_sigurg(struct sock *sk);
1574
1575struct sockcm_cookie {
1576 u32 mark;
1577 u16 tsflags;
1578};
1579
1580int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1581 struct sockcm_cookie *sockc);
1582int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1583 struct sockcm_cookie *sockc);
1584
1585/*
1586 * Functions to fill in entries in struct proto_ops when a protocol
1587 * does not implement a particular function.
1588 */
1589int sock_no_bind(struct socket *, struct sockaddr *, int);
1590int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1591int sock_no_socketpair(struct socket *, struct socket *);
1592int sock_no_accept(struct socket *, struct socket *, int, bool);
1593int sock_no_getname(struct socket *, struct sockaddr *, int);
1594__poll_t sock_no_poll(struct file *, struct socket *,
1595 struct poll_table_struct *);
1596int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1597int sock_no_listen(struct socket *, int);
1598int sock_no_shutdown(struct socket *, int);
1599int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1600int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1601int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1602int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1603int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1604int sock_no_mmap(struct file *file, struct socket *sock,
1605 struct vm_area_struct *vma);
1606ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1607 size_t size, int flags);
1608ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1609 int offset, size_t size, int flags);
1610
1611/*
1612 * Functions to fill in entries in struct proto_ops when a protocol
1613 * uses the inet style.
1614 */
1615int sock_common_getsockopt(struct socket *sock, int level, int optname,
1616 char __user *optval, int __user *optlen);
1617int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1618 int flags);
1619int sock_common_setsockopt(struct socket *sock, int level, int optname,
1620 char __user *optval, unsigned int optlen);
1621int compat_sock_common_getsockopt(struct socket *sock, int level,
1622 int optname, char __user *optval, int __user *optlen);
1623int compat_sock_common_setsockopt(struct socket *sock, int level,
1624 int optname, char __user *optval, unsigned int optlen);
1625
1626void sk_common_release(struct sock *sk);
1627
1628/*
1629 * Default socket callbacks and setup code
1630 */
1631
1632/* Initialise core socket variables */
1633void sock_init_data(struct socket *sock, struct sock *sk);
1634
1635/*
1636 * Socket reference counting postulates.
1637 *
1638 * * Each user of socket SHOULD hold a reference count.
1639 * * Each access point to socket (an hash table bucket, reference from a list,
1640 * running timer, skb in flight MUST hold a reference count.
1641 * * When reference count hits 0, it means it will never increase back.
1642 * * When reference count hits 0, it means that no references from
1643 * outside exist to this socket and current process on current CPU
1644 * is last user and may/should destroy this socket.
1645 * * sk_free is called from any context: process, BH, IRQ. When
1646 * it is called, socket has no references from outside -> sk_free
1647 * may release descendant resources allocated by the socket, but
1648 * to the time when it is called, socket is NOT referenced by any
1649 * hash tables, lists etc.
1650 * * Packets, delivered from outside (from network or from another process)
1651 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1652 * when they sit in queue. Otherwise, packets will leak to hole, when
1653 * socket is looked up by one cpu and unhasing is made by another CPU.
1654 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1655 * (leak to backlog). Packet socket does all the processing inside
1656 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1657 * use separate SMP lock, so that they are prone too.
1658 */
1659
1660/* Ungrab socket and destroy it, if it was the last reference. */
1661static inline void sock_put(struct sock *sk)
1662{
1663 if (refcount_dec_and_test(&sk->sk_refcnt))
1664 sk_free(sk);
1665}
1666/* Generic version of sock_put(), dealing with all sockets
1667 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1668 */
1669void sock_gen_put(struct sock *sk);
1670
1671int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1672 unsigned int trim_cap, bool refcounted);
1673static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1674 const int nested)
1675{
1676 return __sk_receive_skb(sk, skb, nested, 1, true);
1677}
1678
1679static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1680{
1681 sk->sk_tx_queue_mapping = tx_queue;
1682}
1683
1684static inline void sk_tx_queue_clear(struct sock *sk)
1685{
1686 sk->sk_tx_queue_mapping = -1;
1687}
1688
1689static inline int sk_tx_queue_get(const struct sock *sk)
1690{
1691 return sk ? sk->sk_tx_queue_mapping : -1;
1692}
1693
1694static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1695{
1696 sk_tx_queue_clear(sk);
1697 sk->sk_socket = sock;
1698}
1699
1700static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1701{
1702 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1703 return &rcu_dereference_raw(sk->sk_wq)->wait;
1704}
1705/* Detach socket from process context.
1706 * Announce socket dead, detach it from wait queue and inode.
1707 * Note that parent inode held reference count on this struct sock,
1708 * we do not release it in this function, because protocol
1709 * probably wants some additional cleanups or even continuing
1710 * to work with this socket (TCP).
1711 */
1712static inline void sock_orphan(struct sock *sk)
1713{
1714 write_lock_bh(&sk->sk_callback_lock);
1715 sock_set_flag(sk, SOCK_DEAD);
1716 sk_set_socket(sk, NULL);
1717 sk->sk_wq = NULL;
1718 write_unlock_bh(&sk->sk_callback_lock);
1719}
1720
1721static inline void sock_graft(struct sock *sk, struct socket *parent)
1722{
1723 WARN_ON(parent->sk);
1724 write_lock_bh(&sk->sk_callback_lock);
1725 sk->sk_wq = parent->wq;
1726 parent->sk = sk;
1727 sk_set_socket(sk, parent);
1728 sk->sk_uid = SOCK_INODE(parent)->i_uid;
1729 security_sock_graft(sk, parent);
1730 write_unlock_bh(&sk->sk_callback_lock);
1731}
1732
1733kuid_t sock_i_uid(struct sock *sk);
1734unsigned long sock_i_ino(struct sock *sk);
1735
1736static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1737{
1738 return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1739}
1740
1741static inline u32 net_tx_rndhash(void)
1742{
1743 u32 v = prandom_u32();
1744
1745 return v ?: 1;
1746}
1747
1748static inline void sk_set_txhash(struct sock *sk)
1749{
1750 sk->sk_txhash = net_tx_rndhash();
1751}
1752
1753static inline void sk_rethink_txhash(struct sock *sk)
1754{
1755 if (sk->sk_txhash)
1756 sk_set_txhash(sk);
1757}
1758
1759static inline struct dst_entry *
1760__sk_dst_get(struct sock *sk)
1761{
1762 return rcu_dereference_check(sk->sk_dst_cache,
1763 lockdep_sock_is_held(sk));
1764}
1765
1766static inline struct dst_entry *
1767sk_dst_get(struct sock *sk)
1768{
1769 struct dst_entry *dst;
1770
1771 rcu_read_lock();
1772 dst = rcu_dereference(sk->sk_dst_cache);
1773 if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1774 dst = NULL;
1775 rcu_read_unlock();
1776 return dst;
1777}
1778
1779static inline void dst_negative_advice(struct sock *sk)
1780{
1781 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1782
1783 sk_rethink_txhash(sk);
1784
1785 if (dst && dst->ops->negative_advice) {
1786 ndst = dst->ops->negative_advice(dst);
1787
1788 if (ndst != dst) {
1789 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1790 sk_tx_queue_clear(sk);
1791 sk->sk_dst_pending_confirm = 0;
1792 }
1793 }
1794}
1795
1796static inline void
1797__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1798{
1799 struct dst_entry *old_dst;
1800
1801 sk_tx_queue_clear(sk);
1802 sk->sk_dst_pending_confirm = 0;
1803 old_dst = rcu_dereference_protected(sk->sk_dst_cache,
1804 lockdep_sock_is_held(sk));
1805 rcu_assign_pointer(sk->sk_dst_cache, dst);
1806 dst_release(old_dst);
1807}
1808
1809static inline void
1810sk_dst_set(struct sock *sk, struct dst_entry *dst)
1811{
1812 struct dst_entry *old_dst;
1813
1814 sk_tx_queue_clear(sk);
1815 sk->sk_dst_pending_confirm = 0;
1816 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1817 dst_release(old_dst);
1818}
1819
1820static inline void
1821__sk_dst_reset(struct sock *sk)
1822{
1823 __sk_dst_set(sk, NULL);
1824}
1825
1826static inline void
1827sk_dst_reset(struct sock *sk)
1828{
1829 sk_dst_set(sk, NULL);
1830}
1831
1832struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1833
1834struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1835
1836static inline void sk_dst_confirm(struct sock *sk)
1837{
1838 if (!sk->sk_dst_pending_confirm)
1839 sk->sk_dst_pending_confirm = 1;
1840}
1841
1842static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
1843{
1844 if (skb_get_dst_pending_confirm(skb)) {
1845 struct sock *sk = skb->sk;
1846 unsigned long now = jiffies;
1847
1848 /* avoid dirtying neighbour */
1849 if (n->confirmed != now)
1850 n->confirmed = now;
1851 if (sk && sk->sk_dst_pending_confirm)
1852 sk->sk_dst_pending_confirm = 0;
1853 }
1854}
1855
1856bool sk_mc_loop(struct sock *sk);
1857
1858static inline bool sk_can_gso(const struct sock *sk)
1859{
1860 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1861}
1862
1863void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1864
1865static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1866{
1867 sk->sk_route_nocaps |= flags;
1868 sk->sk_route_caps &= ~flags;
1869}
1870
1871static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1872 struct iov_iter *from, char *to,
1873 int copy, int offset)
1874{
1875 if (skb->ip_summed == CHECKSUM_NONE) {
1876 __wsum csum = 0;
1877 if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
1878 return -EFAULT;
1879 skb->csum = csum_block_add(skb->csum, csum, offset);
1880 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1881 if (!copy_from_iter_full_nocache(to, copy, from))
1882 return -EFAULT;
1883 } else if (!copy_from_iter_full(to, copy, from))
1884 return -EFAULT;
1885
1886 return 0;
1887}
1888
1889static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1890 struct iov_iter *from, int copy)
1891{
1892 int err, offset = skb->len;
1893
1894 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1895 copy, offset);
1896 if (err)
1897 __skb_trim(skb, offset);
1898
1899 return err;
1900}
1901
1902static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
1903 struct sk_buff *skb,
1904 struct page *page,
1905 int off, int copy)
1906{
1907 int err;
1908
1909 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1910 copy, skb->len);
1911 if (err)
1912 return err;
1913
1914 skb->len += copy;
1915 skb->data_len += copy;
1916 skb->truesize += copy;
1917 sk->sk_wmem_queued += copy;
1918 sk_mem_charge(sk, copy);
1919 return 0;
1920}
1921
1922/**
1923 * sk_wmem_alloc_get - returns write allocations
1924 * @sk: socket
1925 *
1926 * Returns sk_wmem_alloc minus initial offset of one
1927 */
1928static inline int sk_wmem_alloc_get(const struct sock *sk)
1929{
1930 return refcount_read(&sk->sk_wmem_alloc) - 1;
1931}
1932
1933/**
1934 * sk_rmem_alloc_get - returns read allocations
1935 * @sk: socket
1936 *
1937 * Returns sk_rmem_alloc
1938 */
1939static inline int sk_rmem_alloc_get(const struct sock *sk)
1940{
1941 return atomic_read(&sk->sk_rmem_alloc);
1942}
1943
1944/**
1945 * sk_has_allocations - check if allocations are outstanding
1946 * @sk: socket
1947 *
1948 * Returns true if socket has write or read allocations
1949 */
1950static inline bool sk_has_allocations(const struct sock *sk)
1951{
1952 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1953}
1954
1955/**
1956 * skwq_has_sleeper - check if there are any waiting processes
1957 * @wq: struct socket_wq
1958 *
1959 * Returns true if socket_wq has waiting processes
1960 *
1961 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
1962 * barrier call. They were added due to the race found within the tcp code.
1963 *
1964 * Consider following tcp code paths::
1965 *
1966 * CPU1 CPU2
1967 * sys_select receive packet
1968 * ... ...
1969 * __add_wait_queue update tp->rcv_nxt
1970 * ... ...
1971 * tp->rcv_nxt check sock_def_readable
1972 * ... {
1973 * schedule rcu_read_lock();
1974 * wq = rcu_dereference(sk->sk_wq);
1975 * if (wq && waitqueue_active(&wq->wait))
1976 * wake_up_interruptible(&wq->wait)
1977 * ...
1978 * }
1979 *
1980 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1981 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
1982 * could then endup calling schedule and sleep forever if there are no more
1983 * data on the socket.
1984 *
1985 */
1986static inline bool skwq_has_sleeper(struct socket_wq *wq)
1987{
1988 return wq && wq_has_sleeper(&wq->wait);
1989}
1990
1991/**
1992 * sock_poll_wait - place memory barrier behind the poll_wait call.
1993 * @filp: file
1994 * @wait_address: socket wait queue
1995 * @p: poll_table
1996 *
1997 * See the comments in the wq_has_sleeper function.
1998 */
1999static inline void sock_poll_wait(struct file *filp,
2000 wait_queue_head_t *wait_address, poll_table *p)
2001{
2002 if (!poll_does_not_wait(p) && wait_address) {
2003 poll_wait(filp, wait_address, p);
2004 /* We need to be sure we are in sync with the
2005 * socket flags modification.
2006 *
2007 * This memory barrier is paired in the wq_has_sleeper.
2008 */
2009 smp_mb();
2010 }
2011}
2012
2013static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2014{
2015 if (sk->sk_txhash) {
2016 skb->l4_hash = 1;
2017 skb->hash = sk->sk_txhash;
2018 }
2019}
2020
2021void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2022
2023/*
2024 * Queue a received datagram if it will fit. Stream and sequenced
2025 * protocols can't normally use this as they need to fit buffers in
2026 * and play with them.
2027 *
2028 * Inlined as it's very short and called for pretty much every
2029 * packet ever received.
2030 */
2031static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2032{
2033 skb_orphan(skb);
2034 skb->sk = sk;
2035 skb->destructor = sock_rfree;
2036 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2037 sk_mem_charge(sk, skb->truesize);
2038}
2039
2040void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2041 unsigned long expires);
2042
2043void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2044
2045int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2046 struct sk_buff *skb, unsigned int flags,
2047 void (*destructor)(struct sock *sk,
2048 struct sk_buff *skb));
2049int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2050int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2051
2052int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2053struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2054
2055/*
2056 * Recover an error report and clear atomically
2057 */
2058
2059static inline int sock_error(struct sock *sk)
2060{
2061 int err;
2062 if (likely(!sk->sk_err))
2063 return 0;
2064 err = xchg(&sk->sk_err, 0);
2065 return -err;
2066}
2067
2068static inline unsigned long sock_wspace(struct sock *sk)
2069{
2070 int amt = 0;
2071
2072 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2073 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2074 if (amt < 0)
2075 amt = 0;
2076 }
2077 return amt;
2078}
2079
2080/* Note:
2081 * We use sk->sk_wq_raw, from contexts knowing this
2082 * pointer is not NULL and cannot disappear/change.
2083 */
2084static inline void sk_set_bit(int nr, struct sock *sk)
2085{
2086 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2087 !sock_flag(sk, SOCK_FASYNC))
2088 return;
2089
2090 set_bit(nr, &sk->sk_wq_raw->flags);
2091}
2092
2093static inline void sk_clear_bit(int nr, struct sock *sk)
2094{
2095 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2096 !sock_flag(sk, SOCK_FASYNC))
2097 return;
2098
2099 clear_bit(nr, &sk->sk_wq_raw->flags);
2100}
2101
2102static inline void sk_wake_async(const struct sock *sk, int how, int band)
2103{
2104 if (sock_flag(sk, SOCK_FASYNC)) {
2105 rcu_read_lock();
2106 sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2107 rcu_read_unlock();
2108 }
2109}
2110
2111/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2112 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2113 * Note: for send buffers, TCP works better if we can build two skbs at
2114 * minimum.
2115 */
2116#define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2117
2118#define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
2119#define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
2120
2121static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2122{
2123 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
2124 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2125 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
2126 }
2127}
2128
2129struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2130 bool force_schedule);
2131
2132/**
2133 * sk_page_frag - return an appropriate page_frag
2134 * @sk: socket
2135 *
2136 * If socket allocation mode allows current thread to sleep, it means its
2137 * safe to use the per task page_frag instead of the per socket one.
2138 */
2139static inline struct page_frag *sk_page_frag(struct sock *sk)
2140{
2141 if (gfpflags_allow_blocking(sk->sk_allocation))
2142 return ¤t->task_frag;
2143
2144 return &sk->sk_frag;
2145}
2146
2147bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2148
2149int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
2150 int sg_start, int *sg_curr, unsigned int *sg_size,
2151 int first_coalesce);
2152
2153/*
2154 * Default write policy as shown to user space via poll/select/SIGIO
2155 */
2156static inline bool sock_writeable(const struct sock *sk)
2157{
2158 return refcount_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2159}
2160
2161static inline gfp_t gfp_any(void)
2162{
2163 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2164}
2165
2166static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2167{
2168 return noblock ? 0 : sk->sk_rcvtimeo;
2169}
2170
2171static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2172{
2173 return noblock ? 0 : sk->sk_sndtimeo;
2174}
2175
2176static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2177{
2178 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2179}
2180
2181/* Alas, with timeout socket operations are not restartable.
2182 * Compare this to poll().
2183 */
2184static inline int sock_intr_errno(long timeo)
2185{
2186 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2187}
2188
2189struct sock_skb_cb {
2190 u32 dropcount;
2191};
2192
2193/* Store sock_skb_cb at the end of skb->cb[] so protocol families
2194 * using skb->cb[] would keep using it directly and utilize its
2195 * alignement guarantee.
2196 */
2197#define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \
2198 sizeof(struct sock_skb_cb)))
2199
2200#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2201 SOCK_SKB_CB_OFFSET))
2202
2203#define sock_skb_cb_check_size(size) \
2204 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2205
2206static inline void
2207sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2208{
2209 SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2210 atomic_read(&sk->sk_drops) : 0;
2211}
2212
2213static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2214{
2215 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2216
2217 atomic_add(segs, &sk->sk_drops);
2218}
2219
2220void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2221 struct sk_buff *skb);
2222void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2223 struct sk_buff *skb);
2224
2225static inline void
2226sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2227{
2228 ktime_t kt = skb->tstamp;
2229 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2230
2231 /*
2232 * generate control messages if
2233 * - receive time stamping in software requested
2234 * - software time stamp available and wanted
2235 * - hardware time stamps available and wanted
2236 */
2237 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2238 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2239 (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2240 (hwtstamps->hwtstamp &&
2241 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2242 __sock_recv_timestamp(msg, sk, skb);
2243 else
2244 sk->sk_stamp = kt;
2245
2246 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2247 __sock_recv_wifi_status(msg, sk, skb);
2248}
2249
2250void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2251 struct sk_buff *skb);
2252
2253#define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2254static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2255 struct sk_buff *skb)
2256{
2257#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2258 (1UL << SOCK_RCVTSTAMP))
2259#define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \
2260 SOF_TIMESTAMPING_RAW_HARDWARE)
2261
2262 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2263 __sock_recv_ts_and_drops(msg, sk, skb);
2264 else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2265 sk->sk_stamp = skb->tstamp;
2266 else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2267 sk->sk_stamp = 0;
2268}
2269
2270void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2271
2272/**
2273 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2274 * @sk: socket sending this packet
2275 * @tsflags: timestamping flags to use
2276 * @tx_flags: completed with instructions for time stamping
2277 *
2278 * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2279 */
2280static inline void sock_tx_timestamp(const struct sock *sk, __u16 tsflags,
2281 __u8 *tx_flags)
2282{
2283 if (unlikely(tsflags))
2284 __sock_tx_timestamp(tsflags, tx_flags);
2285 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2286 *tx_flags |= SKBTX_WIFI_STATUS;
2287}
2288
2289/**
2290 * sk_eat_skb - Release a skb if it is no longer needed
2291 * @sk: socket to eat this skb from
2292 * @skb: socket buffer to eat
2293 *
2294 * This routine must be called with interrupts disabled or with the socket
2295 * locked so that the sk_buff queue operation is ok.
2296*/
2297static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2298{
2299 __skb_unlink(skb, &sk->sk_receive_queue);
2300 __kfree_skb(skb);
2301}
2302
2303static inline
2304struct net *sock_net(const struct sock *sk)
2305{
2306 return read_pnet(&sk->sk_net);
2307}
2308
2309static inline
2310void sock_net_set(struct sock *sk, struct net *net)
2311{
2312 write_pnet(&sk->sk_net, net);
2313}
2314
2315static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2316{
2317 if (skb->sk) {
2318 struct sock *sk = skb->sk;
2319
2320 skb->destructor = NULL;
2321 skb->sk = NULL;
2322 return sk;
2323 }
2324 return NULL;
2325}
2326
2327/* This helper checks if a socket is a full socket,
2328 * ie _not_ a timewait or request socket.
2329 */
2330static inline bool sk_fullsock(const struct sock *sk)
2331{
2332 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2333}
2334
2335/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2336 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2337 */
2338static inline bool sk_listener(const struct sock *sk)
2339{
2340 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2341}
2342
2343void sock_enable_timestamp(struct sock *sk, int flag);
2344int sock_get_timestamp(struct sock *, struct timeval __user *);
2345int sock_get_timestampns(struct sock *, struct timespec __user *);
2346int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2347 int type);
2348
2349bool sk_ns_capable(const struct sock *sk,
2350 struct user_namespace *user_ns, int cap);
2351bool sk_capable(const struct sock *sk, int cap);
2352bool sk_net_capable(const struct sock *sk, int cap);
2353
2354void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2355
2356/* Take into consideration the size of the struct sk_buff overhead in the
2357 * determination of these values, since that is non-constant across
2358 * platforms. This makes socket queueing behavior and performance
2359 * not depend upon such differences.
2360 */
2361#define _SK_MEM_PACKETS 256
2362#define _SK_MEM_OVERHEAD SKB_TRUESIZE(256)
2363#define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2364#define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2365
2366extern __u32 sysctl_wmem_max;
2367extern __u32 sysctl_rmem_max;
2368
2369extern int sysctl_tstamp_allow_data;
2370extern int sysctl_optmem_max;
2371
2372extern __u32 sysctl_wmem_default;
2373extern __u32 sysctl_rmem_default;
2374
2375static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2376{
2377 /* Does this proto have per netns sysctl_wmem ? */
2378 if (proto->sysctl_wmem_offset)
2379 return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2380
2381 return *proto->sysctl_wmem;
2382}
2383
2384static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2385{
2386 /* Does this proto have per netns sysctl_rmem ? */
2387 if (proto->sysctl_rmem_offset)
2388 return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2389
2390 return *proto->sysctl_rmem;
2391}
2392
2393/* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2394 * Some wifi drivers need to tweak it to get more chunks.
2395 * They can use this helper from their ndo_start_xmit()
2396 */
2397static inline void sk_pacing_shift_update(struct sock *sk, int val)
2398{
2399 if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val)
2400 return;
2401 sk->sk_pacing_shift = val;
2402}
2403
2404/* if a socket is bound to a device, check that the given device
2405 * index is either the same or that the socket is bound to an L3
2406 * master device and the given device index is also enslaved to
2407 * that L3 master
2408 */
2409static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2410{
2411 int mdif;
2412
2413 if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2414 return true;
2415
2416 mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2417 if (mdif && mdif == sk->sk_bound_dev_if)
2418 return true;
2419
2420 return false;
2421}
2422
2423#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/memcontrol.h>
58#include <linux/res_counter.h>
59#include <linux/static_key.h>
60#include <linux/aio.h>
61#include <linux/sched.h>
62
63#include <linux/filter.h>
64#include <linux/rculist_nulls.h>
65#include <linux/poll.h>
66
67#include <linux/atomic.h>
68#include <net/dst.h>
69#include <net/checksum.h>
70
71struct cgroup;
72struct cgroup_subsys;
73#ifdef CONFIG_NET
74int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
75void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg);
76#else
77static inline
78int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
79{
80 return 0;
81}
82static inline
83void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
84{
85}
86#endif
87/*
88 * This structure really needs to be cleaned up.
89 * Most of it is for TCP, and not used by any of
90 * the other protocols.
91 */
92
93/* Define this to get the SOCK_DBG debugging facility. */
94#define SOCK_DEBUGGING
95#ifdef SOCK_DEBUGGING
96#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
97 printk(KERN_DEBUG msg); } while (0)
98#else
99/* Validate arguments and do nothing */
100static inline __printf(2, 3)
101void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
102{
103}
104#endif
105
106/* This is the per-socket lock. The spinlock provides a synchronization
107 * between user contexts and software interrupt processing, whereas the
108 * mini-semaphore synchronizes multiple users amongst themselves.
109 */
110typedef struct {
111 spinlock_t slock;
112 int owned;
113 wait_queue_head_t wq;
114 /*
115 * We express the mutex-alike socket_lock semantics
116 * to the lock validator by explicitly managing
117 * the slock as a lock variant (in addition to
118 * the slock itself):
119 */
120#ifdef CONFIG_DEBUG_LOCK_ALLOC
121 struct lockdep_map dep_map;
122#endif
123} socket_lock_t;
124
125struct sock;
126struct proto;
127struct net;
128
129/**
130 * struct sock_common - minimal network layer representation of sockets
131 * @skc_daddr: Foreign IPv4 addr
132 * @skc_rcv_saddr: Bound local IPv4 addr
133 * @skc_hash: hash value used with various protocol lookup tables
134 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
135 * @skc_family: network address family
136 * @skc_state: Connection state
137 * @skc_reuse: %SO_REUSEADDR setting
138 * @skc_bound_dev_if: bound device index if != 0
139 * @skc_bind_node: bind hash linkage for various protocol lookup tables
140 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
141 * @skc_prot: protocol handlers inside a network family
142 * @skc_net: reference to the network namespace of this socket
143 * @skc_node: main hash linkage for various protocol lookup tables
144 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
145 * @skc_tx_queue_mapping: tx queue number for this connection
146 * @skc_refcnt: reference count
147 *
148 * This is the minimal network layer representation of sockets, the header
149 * for struct sock and struct inet_timewait_sock.
150 */
151struct sock_common {
152 /* skc_daddr and skc_rcv_saddr must be grouped :
153 * cf INET_MATCH() and INET_TW_MATCH()
154 */
155 __be32 skc_daddr;
156 __be32 skc_rcv_saddr;
157
158 union {
159 unsigned int skc_hash;
160 __u16 skc_u16hashes[2];
161 };
162 unsigned short skc_family;
163 volatile unsigned char skc_state;
164 unsigned char skc_reuse;
165 int skc_bound_dev_if;
166 union {
167 struct hlist_node skc_bind_node;
168 struct hlist_nulls_node skc_portaddr_node;
169 };
170 struct proto *skc_prot;
171#ifdef CONFIG_NET_NS
172 struct net *skc_net;
173#endif
174 /*
175 * fields between dontcopy_begin/dontcopy_end
176 * are not copied in sock_copy()
177 */
178 /* private: */
179 int skc_dontcopy_begin[0];
180 /* public: */
181 union {
182 struct hlist_node skc_node;
183 struct hlist_nulls_node skc_nulls_node;
184 };
185 int skc_tx_queue_mapping;
186 atomic_t skc_refcnt;
187 /* private: */
188 int skc_dontcopy_end[0];
189 /* public: */
190};
191
192struct cg_proto;
193/**
194 * struct sock - network layer representation of sockets
195 * @__sk_common: shared layout with inet_timewait_sock
196 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
197 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
198 * @sk_lock: synchronizer
199 * @sk_rcvbuf: size of receive buffer in bytes
200 * @sk_wq: sock wait queue and async head
201 * @sk_dst_cache: destination cache
202 * @sk_dst_lock: destination cache lock
203 * @sk_policy: flow policy
204 * @sk_receive_queue: incoming packets
205 * @sk_wmem_alloc: transmit queue bytes committed
206 * @sk_write_queue: Packet sending queue
207 * @sk_async_wait_queue: DMA copied packets
208 * @sk_omem_alloc: "o" is "option" or "other"
209 * @sk_wmem_queued: persistent queue size
210 * @sk_forward_alloc: space allocated forward
211 * @sk_allocation: allocation mode
212 * @sk_sndbuf: size of send buffer in bytes
213 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
214 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
215 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
216 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
217 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
218 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
219 * @sk_gso_max_size: Maximum GSO segment size to build
220 * @sk_gso_max_segs: Maximum number of GSO segments
221 * @sk_lingertime: %SO_LINGER l_linger setting
222 * @sk_backlog: always used with the per-socket spinlock held
223 * @sk_callback_lock: used with the callbacks in the end of this struct
224 * @sk_error_queue: rarely used
225 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
226 * IPV6_ADDRFORM for instance)
227 * @sk_err: last error
228 * @sk_err_soft: errors that don't cause failure but are the cause of a
229 * persistent failure not just 'timed out'
230 * @sk_drops: raw/udp drops counter
231 * @sk_ack_backlog: current listen backlog
232 * @sk_max_ack_backlog: listen backlog set in listen()
233 * @sk_priority: %SO_PRIORITY setting
234 * @sk_cgrp_prioidx: socket group's priority map index
235 * @sk_type: socket type (%SOCK_STREAM, etc)
236 * @sk_protocol: which protocol this socket belongs in this network family
237 * @sk_peer_pid: &struct pid for this socket's peer
238 * @sk_peer_cred: %SO_PEERCRED setting
239 * @sk_rcvlowat: %SO_RCVLOWAT setting
240 * @sk_rcvtimeo: %SO_RCVTIMEO setting
241 * @sk_sndtimeo: %SO_SNDTIMEO setting
242 * @sk_rxhash: flow hash received from netif layer
243 * @sk_filter: socket filtering instructions
244 * @sk_protinfo: private area, net family specific, when not using slab
245 * @sk_timer: sock cleanup timer
246 * @sk_stamp: time stamp of last packet received
247 * @sk_socket: Identd and reporting IO signals
248 * @sk_user_data: RPC layer private data
249 * @sk_sndmsg_page: cached page for sendmsg
250 * @sk_sndmsg_off: cached offset for sendmsg
251 * @sk_peek_off: current peek_offset value
252 * @sk_send_head: front of stuff to transmit
253 * @sk_security: used by security modules
254 * @sk_mark: generic packet mark
255 * @sk_classid: this socket's cgroup classid
256 * @sk_cgrp: this socket's cgroup-specific proto data
257 * @sk_write_pending: a write to stream socket waits to start
258 * @sk_state_change: callback to indicate change in the state of the sock
259 * @sk_data_ready: callback to indicate there is data to be processed
260 * @sk_write_space: callback to indicate there is bf sending space available
261 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
262 * @sk_backlog_rcv: callback to process the backlog
263 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
264 */
265struct sock {
266 /*
267 * Now struct inet_timewait_sock also uses sock_common, so please just
268 * don't add nothing before this first member (__sk_common) --acme
269 */
270 struct sock_common __sk_common;
271#define sk_node __sk_common.skc_node
272#define sk_nulls_node __sk_common.skc_nulls_node
273#define sk_refcnt __sk_common.skc_refcnt
274#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
275
276#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
277#define sk_dontcopy_end __sk_common.skc_dontcopy_end
278#define sk_hash __sk_common.skc_hash
279#define sk_family __sk_common.skc_family
280#define sk_state __sk_common.skc_state
281#define sk_reuse __sk_common.skc_reuse
282#define sk_bound_dev_if __sk_common.skc_bound_dev_if
283#define sk_bind_node __sk_common.skc_bind_node
284#define sk_prot __sk_common.skc_prot
285#define sk_net __sk_common.skc_net
286 socket_lock_t sk_lock;
287 struct sk_buff_head sk_receive_queue;
288 /*
289 * The backlog queue is special, it is always used with
290 * the per-socket spinlock held and requires low latency
291 * access. Therefore we special case it's implementation.
292 * Note : rmem_alloc is in this structure to fill a hole
293 * on 64bit arches, not because its logically part of
294 * backlog.
295 */
296 struct {
297 atomic_t rmem_alloc;
298 int len;
299 struct sk_buff *head;
300 struct sk_buff *tail;
301 } sk_backlog;
302#define sk_rmem_alloc sk_backlog.rmem_alloc
303 int sk_forward_alloc;
304#ifdef CONFIG_RPS
305 __u32 sk_rxhash;
306#endif
307 atomic_t sk_drops;
308 int sk_rcvbuf;
309
310 struct sk_filter __rcu *sk_filter;
311 struct socket_wq __rcu *sk_wq;
312
313#ifdef CONFIG_NET_DMA
314 struct sk_buff_head sk_async_wait_queue;
315#endif
316
317#ifdef CONFIG_XFRM
318 struct xfrm_policy *sk_policy[2];
319#endif
320 unsigned long sk_flags;
321 struct dst_entry *sk_dst_cache;
322 spinlock_t sk_dst_lock;
323 atomic_t sk_wmem_alloc;
324 atomic_t sk_omem_alloc;
325 int sk_sndbuf;
326 struct sk_buff_head sk_write_queue;
327 kmemcheck_bitfield_begin(flags);
328 unsigned int sk_shutdown : 2,
329 sk_no_check : 2,
330 sk_userlocks : 4,
331 sk_protocol : 8,
332 sk_type : 16;
333 kmemcheck_bitfield_end(flags);
334 int sk_wmem_queued;
335 gfp_t sk_allocation;
336 netdev_features_t sk_route_caps;
337 netdev_features_t sk_route_nocaps;
338 int sk_gso_type;
339 unsigned int sk_gso_max_size;
340 u16 sk_gso_max_segs;
341 int sk_rcvlowat;
342 unsigned long sk_lingertime;
343 struct sk_buff_head sk_error_queue;
344 struct proto *sk_prot_creator;
345 rwlock_t sk_callback_lock;
346 int sk_err,
347 sk_err_soft;
348 unsigned short sk_ack_backlog;
349 unsigned short sk_max_ack_backlog;
350 __u32 sk_priority;
351#ifdef CONFIG_CGROUPS
352 __u32 sk_cgrp_prioidx;
353#endif
354 struct pid *sk_peer_pid;
355 const struct cred *sk_peer_cred;
356 long sk_rcvtimeo;
357 long sk_sndtimeo;
358 void *sk_protinfo;
359 struct timer_list sk_timer;
360 ktime_t sk_stamp;
361 struct socket *sk_socket;
362 void *sk_user_data;
363 struct page *sk_sndmsg_page;
364 struct sk_buff *sk_send_head;
365 __u32 sk_sndmsg_off;
366 __s32 sk_peek_off;
367 int sk_write_pending;
368#ifdef CONFIG_SECURITY
369 void *sk_security;
370#endif
371 __u32 sk_mark;
372 u32 sk_classid;
373 struct cg_proto *sk_cgrp;
374 void (*sk_state_change)(struct sock *sk);
375 void (*sk_data_ready)(struct sock *sk, int bytes);
376 void (*sk_write_space)(struct sock *sk);
377 void (*sk_error_report)(struct sock *sk);
378 int (*sk_backlog_rcv)(struct sock *sk,
379 struct sk_buff *skb);
380 void (*sk_destruct)(struct sock *sk);
381};
382
383/*
384 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
385 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
386 * on a socket means that the socket will reuse everybody else's port
387 * without looking at the other's sk_reuse value.
388 */
389
390#define SK_NO_REUSE 0
391#define SK_CAN_REUSE 1
392#define SK_FORCE_REUSE 2
393
394static inline int sk_peek_offset(struct sock *sk, int flags)
395{
396 if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
397 return sk->sk_peek_off;
398 else
399 return 0;
400}
401
402static inline void sk_peek_offset_bwd(struct sock *sk, int val)
403{
404 if (sk->sk_peek_off >= 0) {
405 if (sk->sk_peek_off >= val)
406 sk->sk_peek_off -= val;
407 else
408 sk->sk_peek_off = 0;
409 }
410}
411
412static inline void sk_peek_offset_fwd(struct sock *sk, int val)
413{
414 if (sk->sk_peek_off >= 0)
415 sk->sk_peek_off += val;
416}
417
418/*
419 * Hashed lists helper routines
420 */
421static inline struct sock *sk_entry(const struct hlist_node *node)
422{
423 return hlist_entry(node, struct sock, sk_node);
424}
425
426static inline struct sock *__sk_head(const struct hlist_head *head)
427{
428 return hlist_entry(head->first, struct sock, sk_node);
429}
430
431static inline struct sock *sk_head(const struct hlist_head *head)
432{
433 return hlist_empty(head) ? NULL : __sk_head(head);
434}
435
436static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
437{
438 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
439}
440
441static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
442{
443 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
444}
445
446static inline struct sock *sk_next(const struct sock *sk)
447{
448 return sk->sk_node.next ?
449 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
450}
451
452static inline struct sock *sk_nulls_next(const struct sock *sk)
453{
454 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
455 hlist_nulls_entry(sk->sk_nulls_node.next,
456 struct sock, sk_nulls_node) :
457 NULL;
458}
459
460static inline bool sk_unhashed(const struct sock *sk)
461{
462 return hlist_unhashed(&sk->sk_node);
463}
464
465static inline bool sk_hashed(const struct sock *sk)
466{
467 return !sk_unhashed(sk);
468}
469
470static inline void sk_node_init(struct hlist_node *node)
471{
472 node->pprev = NULL;
473}
474
475static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
476{
477 node->pprev = NULL;
478}
479
480static inline void __sk_del_node(struct sock *sk)
481{
482 __hlist_del(&sk->sk_node);
483}
484
485/* NB: equivalent to hlist_del_init_rcu */
486static inline bool __sk_del_node_init(struct sock *sk)
487{
488 if (sk_hashed(sk)) {
489 __sk_del_node(sk);
490 sk_node_init(&sk->sk_node);
491 return true;
492 }
493 return false;
494}
495
496/* Grab socket reference count. This operation is valid only
497 when sk is ALREADY grabbed f.e. it is found in hash table
498 or a list and the lookup is made under lock preventing hash table
499 modifications.
500 */
501
502static inline void sock_hold(struct sock *sk)
503{
504 atomic_inc(&sk->sk_refcnt);
505}
506
507/* Ungrab socket in the context, which assumes that socket refcnt
508 cannot hit zero, f.e. it is true in context of any socketcall.
509 */
510static inline void __sock_put(struct sock *sk)
511{
512 atomic_dec(&sk->sk_refcnt);
513}
514
515static inline bool sk_del_node_init(struct sock *sk)
516{
517 bool rc = __sk_del_node_init(sk);
518
519 if (rc) {
520 /* paranoid for a while -acme */
521 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
522 __sock_put(sk);
523 }
524 return rc;
525}
526#define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
527
528static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
529{
530 if (sk_hashed(sk)) {
531 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
532 return true;
533 }
534 return false;
535}
536
537static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
538{
539 bool rc = __sk_nulls_del_node_init_rcu(sk);
540
541 if (rc) {
542 /* paranoid for a while -acme */
543 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
544 __sock_put(sk);
545 }
546 return rc;
547}
548
549static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
550{
551 hlist_add_head(&sk->sk_node, list);
552}
553
554static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
555{
556 sock_hold(sk);
557 __sk_add_node(sk, list);
558}
559
560static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
561{
562 sock_hold(sk);
563 hlist_add_head_rcu(&sk->sk_node, list);
564}
565
566static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
567{
568 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
569}
570
571static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
572{
573 sock_hold(sk);
574 __sk_nulls_add_node_rcu(sk, list);
575}
576
577static inline void __sk_del_bind_node(struct sock *sk)
578{
579 __hlist_del(&sk->sk_bind_node);
580}
581
582static inline void sk_add_bind_node(struct sock *sk,
583 struct hlist_head *list)
584{
585 hlist_add_head(&sk->sk_bind_node, list);
586}
587
588#define sk_for_each(__sk, node, list) \
589 hlist_for_each_entry(__sk, node, list, sk_node)
590#define sk_for_each_rcu(__sk, node, list) \
591 hlist_for_each_entry_rcu(__sk, node, list, sk_node)
592#define sk_nulls_for_each(__sk, node, list) \
593 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
594#define sk_nulls_for_each_rcu(__sk, node, list) \
595 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
596#define sk_for_each_from(__sk, node) \
597 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
598 hlist_for_each_entry_from(__sk, node, sk_node)
599#define sk_nulls_for_each_from(__sk, node) \
600 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
601 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
602#define sk_for_each_safe(__sk, node, tmp, list) \
603 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
604#define sk_for_each_bound(__sk, node, list) \
605 hlist_for_each_entry(__sk, node, list, sk_bind_node)
606
607/* Sock flags */
608enum sock_flags {
609 SOCK_DEAD,
610 SOCK_DONE,
611 SOCK_URGINLINE,
612 SOCK_KEEPOPEN,
613 SOCK_LINGER,
614 SOCK_DESTROY,
615 SOCK_BROADCAST,
616 SOCK_TIMESTAMP,
617 SOCK_ZAPPED,
618 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
619 SOCK_DBG, /* %SO_DEBUG setting */
620 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
621 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
622 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
623 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
624 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */
625 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */
626 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */
627 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
628 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */
629 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
630 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
631 SOCK_FASYNC, /* fasync() active */
632 SOCK_RXQ_OVFL,
633 SOCK_ZEROCOPY, /* buffers from userspace */
634 SOCK_WIFI_STATUS, /* push wifi status to userspace */
635 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
636 * Will use last 4 bytes of packet sent from
637 * user-space instead.
638 */
639};
640
641static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
642{
643 nsk->sk_flags = osk->sk_flags;
644}
645
646static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
647{
648 __set_bit(flag, &sk->sk_flags);
649}
650
651static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
652{
653 __clear_bit(flag, &sk->sk_flags);
654}
655
656static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
657{
658 return test_bit(flag, &sk->sk_flags);
659}
660
661static inline void sk_acceptq_removed(struct sock *sk)
662{
663 sk->sk_ack_backlog--;
664}
665
666static inline void sk_acceptq_added(struct sock *sk)
667{
668 sk->sk_ack_backlog++;
669}
670
671static inline bool sk_acceptq_is_full(const struct sock *sk)
672{
673 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
674}
675
676/*
677 * Compute minimal free write space needed to queue new packets.
678 */
679static inline int sk_stream_min_wspace(const struct sock *sk)
680{
681 return sk->sk_wmem_queued >> 1;
682}
683
684static inline int sk_stream_wspace(const struct sock *sk)
685{
686 return sk->sk_sndbuf - sk->sk_wmem_queued;
687}
688
689extern void sk_stream_write_space(struct sock *sk);
690
691static inline bool sk_stream_memory_free(const struct sock *sk)
692{
693 return sk->sk_wmem_queued < sk->sk_sndbuf;
694}
695
696/* OOB backlog add */
697static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
698{
699 /* dont let skb dst not refcounted, we are going to leave rcu lock */
700 skb_dst_force(skb);
701
702 if (!sk->sk_backlog.tail)
703 sk->sk_backlog.head = skb;
704 else
705 sk->sk_backlog.tail->next = skb;
706
707 sk->sk_backlog.tail = skb;
708 skb->next = NULL;
709}
710
711/*
712 * Take into account size of receive queue and backlog queue
713 * Do not take into account this skb truesize,
714 * to allow even a single big packet to come.
715 */
716static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb,
717 unsigned int limit)
718{
719 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
720
721 return qsize > limit;
722}
723
724/* The per-socket spinlock must be held here. */
725static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
726 unsigned int limit)
727{
728 if (sk_rcvqueues_full(sk, skb, limit))
729 return -ENOBUFS;
730
731 __sk_add_backlog(sk, skb);
732 sk->sk_backlog.len += skb->truesize;
733 return 0;
734}
735
736static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
737{
738 return sk->sk_backlog_rcv(sk, skb);
739}
740
741static inline void sock_rps_record_flow(const struct sock *sk)
742{
743#ifdef CONFIG_RPS
744 struct rps_sock_flow_table *sock_flow_table;
745
746 rcu_read_lock();
747 sock_flow_table = rcu_dereference(rps_sock_flow_table);
748 rps_record_sock_flow(sock_flow_table, sk->sk_rxhash);
749 rcu_read_unlock();
750#endif
751}
752
753static inline void sock_rps_reset_flow(const struct sock *sk)
754{
755#ifdef CONFIG_RPS
756 struct rps_sock_flow_table *sock_flow_table;
757
758 rcu_read_lock();
759 sock_flow_table = rcu_dereference(rps_sock_flow_table);
760 rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash);
761 rcu_read_unlock();
762#endif
763}
764
765static inline void sock_rps_save_rxhash(struct sock *sk,
766 const struct sk_buff *skb)
767{
768#ifdef CONFIG_RPS
769 if (unlikely(sk->sk_rxhash != skb->rxhash)) {
770 sock_rps_reset_flow(sk);
771 sk->sk_rxhash = skb->rxhash;
772 }
773#endif
774}
775
776static inline void sock_rps_reset_rxhash(struct sock *sk)
777{
778#ifdef CONFIG_RPS
779 sock_rps_reset_flow(sk);
780 sk->sk_rxhash = 0;
781#endif
782}
783
784#define sk_wait_event(__sk, __timeo, __condition) \
785 ({ int __rc; \
786 release_sock(__sk); \
787 __rc = __condition; \
788 if (!__rc) { \
789 *(__timeo) = schedule_timeout(*(__timeo)); \
790 } \
791 lock_sock(__sk); \
792 __rc = __condition; \
793 __rc; \
794 })
795
796extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
797extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
798extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
799extern int sk_stream_error(struct sock *sk, int flags, int err);
800extern void sk_stream_kill_queues(struct sock *sk);
801
802extern int sk_wait_data(struct sock *sk, long *timeo);
803
804struct request_sock_ops;
805struct timewait_sock_ops;
806struct inet_hashinfo;
807struct raw_hashinfo;
808struct module;
809
810/* Networking protocol blocks we attach to sockets.
811 * socket layer -> transport layer interface
812 * transport -> network interface is defined by struct inet_proto
813 */
814struct proto {
815 void (*close)(struct sock *sk,
816 long timeout);
817 int (*connect)(struct sock *sk,
818 struct sockaddr *uaddr,
819 int addr_len);
820 int (*disconnect)(struct sock *sk, int flags);
821
822 struct sock * (*accept)(struct sock *sk, int flags, int *err);
823
824 int (*ioctl)(struct sock *sk, int cmd,
825 unsigned long arg);
826 int (*init)(struct sock *sk);
827 void (*destroy)(struct sock *sk);
828 void (*shutdown)(struct sock *sk, int how);
829 int (*setsockopt)(struct sock *sk, int level,
830 int optname, char __user *optval,
831 unsigned int optlen);
832 int (*getsockopt)(struct sock *sk, int level,
833 int optname, char __user *optval,
834 int __user *option);
835#ifdef CONFIG_COMPAT
836 int (*compat_setsockopt)(struct sock *sk,
837 int level,
838 int optname, char __user *optval,
839 unsigned int optlen);
840 int (*compat_getsockopt)(struct sock *sk,
841 int level,
842 int optname, char __user *optval,
843 int __user *option);
844 int (*compat_ioctl)(struct sock *sk,
845 unsigned int cmd, unsigned long arg);
846#endif
847 int (*sendmsg)(struct kiocb *iocb, struct sock *sk,
848 struct msghdr *msg, size_t len);
849 int (*recvmsg)(struct kiocb *iocb, struct sock *sk,
850 struct msghdr *msg,
851 size_t len, int noblock, int flags,
852 int *addr_len);
853 int (*sendpage)(struct sock *sk, struct page *page,
854 int offset, size_t size, int flags);
855 int (*bind)(struct sock *sk,
856 struct sockaddr *uaddr, int addr_len);
857
858 int (*backlog_rcv) (struct sock *sk,
859 struct sk_buff *skb);
860
861 /* Keeping track of sk's, looking them up, and port selection methods. */
862 void (*hash)(struct sock *sk);
863 void (*unhash)(struct sock *sk);
864 void (*rehash)(struct sock *sk);
865 int (*get_port)(struct sock *sk, unsigned short snum);
866 void (*clear_sk)(struct sock *sk, int size);
867
868 /* Keeping track of sockets in use */
869#ifdef CONFIG_PROC_FS
870 unsigned int inuse_idx;
871#endif
872
873 /* Memory pressure */
874 void (*enter_memory_pressure)(struct sock *sk);
875 atomic_long_t *memory_allocated; /* Current allocated memory. */
876 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
877 /*
878 * Pressure flag: try to collapse.
879 * Technical note: it is used by multiple contexts non atomically.
880 * All the __sk_mem_schedule() is of this nature: accounting
881 * is strict, actions are advisory and have some latency.
882 */
883 int *memory_pressure;
884 long *sysctl_mem;
885 int *sysctl_wmem;
886 int *sysctl_rmem;
887 int max_header;
888 bool no_autobind;
889
890 struct kmem_cache *slab;
891 unsigned int obj_size;
892 int slab_flags;
893
894 struct percpu_counter *orphan_count;
895
896 struct request_sock_ops *rsk_prot;
897 struct timewait_sock_ops *twsk_prot;
898
899 union {
900 struct inet_hashinfo *hashinfo;
901 struct udp_table *udp_table;
902 struct raw_hashinfo *raw_hash;
903 } h;
904
905 struct module *owner;
906
907 char name[32];
908
909 struct list_head node;
910#ifdef SOCK_REFCNT_DEBUG
911 atomic_t socks;
912#endif
913#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
914 /*
915 * cgroup specific init/deinit functions. Called once for all
916 * protocols that implement it, from cgroups populate function.
917 * This function has to setup any files the protocol want to
918 * appear in the kmem cgroup filesystem.
919 */
920 int (*init_cgroup)(struct mem_cgroup *memcg,
921 struct cgroup_subsys *ss);
922 void (*destroy_cgroup)(struct mem_cgroup *memcg);
923 struct cg_proto *(*proto_cgroup)(struct mem_cgroup *memcg);
924#endif
925};
926
927/*
928 * Bits in struct cg_proto.flags
929 */
930enum cg_proto_flags {
931 /* Currently active and new sockets should be assigned to cgroups */
932 MEMCG_SOCK_ACTIVE,
933 /* It was ever activated; we must disarm static keys on destruction */
934 MEMCG_SOCK_ACTIVATED,
935};
936
937struct cg_proto {
938 void (*enter_memory_pressure)(struct sock *sk);
939 struct res_counter *memory_allocated; /* Current allocated memory. */
940 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
941 int *memory_pressure;
942 long *sysctl_mem;
943 unsigned long flags;
944 /*
945 * memcg field is used to find which memcg we belong directly
946 * Each memcg struct can hold more than one cg_proto, so container_of
947 * won't really cut.
948 *
949 * The elegant solution would be having an inverse function to
950 * proto_cgroup in struct proto, but that means polluting the structure
951 * for everybody, instead of just for memcg users.
952 */
953 struct mem_cgroup *memcg;
954};
955
956extern int proto_register(struct proto *prot, int alloc_slab);
957extern void proto_unregister(struct proto *prot);
958
959static inline bool memcg_proto_active(struct cg_proto *cg_proto)
960{
961 return test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
962}
963
964static inline bool memcg_proto_activated(struct cg_proto *cg_proto)
965{
966 return test_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags);
967}
968
969#ifdef SOCK_REFCNT_DEBUG
970static inline void sk_refcnt_debug_inc(struct sock *sk)
971{
972 atomic_inc(&sk->sk_prot->socks);
973}
974
975static inline void sk_refcnt_debug_dec(struct sock *sk)
976{
977 atomic_dec(&sk->sk_prot->socks);
978 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
979 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
980}
981
982inline void sk_refcnt_debug_release(const struct sock *sk)
983{
984 if (atomic_read(&sk->sk_refcnt) != 1)
985 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
986 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
987}
988#else /* SOCK_REFCNT_DEBUG */
989#define sk_refcnt_debug_inc(sk) do { } while (0)
990#define sk_refcnt_debug_dec(sk) do { } while (0)
991#define sk_refcnt_debug_release(sk) do { } while (0)
992#endif /* SOCK_REFCNT_DEBUG */
993
994#if defined(CONFIG_CGROUP_MEM_RES_CTLR_KMEM) && defined(CONFIG_NET)
995extern struct static_key memcg_socket_limit_enabled;
996static inline struct cg_proto *parent_cg_proto(struct proto *proto,
997 struct cg_proto *cg_proto)
998{
999 return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg));
1000}
1001#define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled)
1002#else
1003#define mem_cgroup_sockets_enabled 0
1004static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1005 struct cg_proto *cg_proto)
1006{
1007 return NULL;
1008}
1009#endif
1010
1011
1012static inline bool sk_has_memory_pressure(const struct sock *sk)
1013{
1014 return sk->sk_prot->memory_pressure != NULL;
1015}
1016
1017static inline bool sk_under_memory_pressure(const struct sock *sk)
1018{
1019 if (!sk->sk_prot->memory_pressure)
1020 return false;
1021
1022 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1023 return !!*sk->sk_cgrp->memory_pressure;
1024
1025 return !!*sk->sk_prot->memory_pressure;
1026}
1027
1028static inline void sk_leave_memory_pressure(struct sock *sk)
1029{
1030 int *memory_pressure = sk->sk_prot->memory_pressure;
1031
1032 if (!memory_pressure)
1033 return;
1034
1035 if (*memory_pressure)
1036 *memory_pressure = 0;
1037
1038 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1039 struct cg_proto *cg_proto = sk->sk_cgrp;
1040 struct proto *prot = sk->sk_prot;
1041
1042 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1043 if (*cg_proto->memory_pressure)
1044 *cg_proto->memory_pressure = 0;
1045 }
1046
1047}
1048
1049static inline void sk_enter_memory_pressure(struct sock *sk)
1050{
1051 if (!sk->sk_prot->enter_memory_pressure)
1052 return;
1053
1054 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1055 struct cg_proto *cg_proto = sk->sk_cgrp;
1056 struct proto *prot = sk->sk_prot;
1057
1058 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1059 cg_proto->enter_memory_pressure(sk);
1060 }
1061
1062 sk->sk_prot->enter_memory_pressure(sk);
1063}
1064
1065static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1066{
1067 long *prot = sk->sk_prot->sysctl_mem;
1068 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1069 prot = sk->sk_cgrp->sysctl_mem;
1070 return prot[index];
1071}
1072
1073static inline void memcg_memory_allocated_add(struct cg_proto *prot,
1074 unsigned long amt,
1075 int *parent_status)
1076{
1077 struct res_counter *fail;
1078 int ret;
1079
1080 ret = res_counter_charge_nofail(prot->memory_allocated,
1081 amt << PAGE_SHIFT, &fail);
1082 if (ret < 0)
1083 *parent_status = OVER_LIMIT;
1084}
1085
1086static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
1087 unsigned long amt)
1088{
1089 res_counter_uncharge(prot->memory_allocated, amt << PAGE_SHIFT);
1090}
1091
1092static inline u64 memcg_memory_allocated_read(struct cg_proto *prot)
1093{
1094 u64 ret;
1095 ret = res_counter_read_u64(prot->memory_allocated, RES_USAGE);
1096 return ret >> PAGE_SHIFT;
1097}
1098
1099static inline long
1100sk_memory_allocated(const struct sock *sk)
1101{
1102 struct proto *prot = sk->sk_prot;
1103 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1104 return memcg_memory_allocated_read(sk->sk_cgrp);
1105
1106 return atomic_long_read(prot->memory_allocated);
1107}
1108
1109static inline long
1110sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status)
1111{
1112 struct proto *prot = sk->sk_prot;
1113
1114 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1115 memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status);
1116 /* update the root cgroup regardless */
1117 atomic_long_add_return(amt, prot->memory_allocated);
1118 return memcg_memory_allocated_read(sk->sk_cgrp);
1119 }
1120
1121 return atomic_long_add_return(amt, prot->memory_allocated);
1122}
1123
1124static inline void
1125sk_memory_allocated_sub(struct sock *sk, int amt)
1126{
1127 struct proto *prot = sk->sk_prot;
1128
1129 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1130 memcg_memory_allocated_sub(sk->sk_cgrp, amt);
1131
1132 atomic_long_sub(amt, prot->memory_allocated);
1133}
1134
1135static inline void sk_sockets_allocated_dec(struct sock *sk)
1136{
1137 struct proto *prot = sk->sk_prot;
1138
1139 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1140 struct cg_proto *cg_proto = sk->sk_cgrp;
1141
1142 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1143 percpu_counter_dec(cg_proto->sockets_allocated);
1144 }
1145
1146 percpu_counter_dec(prot->sockets_allocated);
1147}
1148
1149static inline void sk_sockets_allocated_inc(struct sock *sk)
1150{
1151 struct proto *prot = sk->sk_prot;
1152
1153 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1154 struct cg_proto *cg_proto = sk->sk_cgrp;
1155
1156 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1157 percpu_counter_inc(cg_proto->sockets_allocated);
1158 }
1159
1160 percpu_counter_inc(prot->sockets_allocated);
1161}
1162
1163static inline int
1164sk_sockets_allocated_read_positive(struct sock *sk)
1165{
1166 struct proto *prot = sk->sk_prot;
1167
1168 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1169 return percpu_counter_read_positive(sk->sk_cgrp->sockets_allocated);
1170
1171 return percpu_counter_read_positive(prot->sockets_allocated);
1172}
1173
1174static inline int
1175proto_sockets_allocated_sum_positive(struct proto *prot)
1176{
1177 return percpu_counter_sum_positive(prot->sockets_allocated);
1178}
1179
1180static inline long
1181proto_memory_allocated(struct proto *prot)
1182{
1183 return atomic_long_read(prot->memory_allocated);
1184}
1185
1186static inline bool
1187proto_memory_pressure(struct proto *prot)
1188{
1189 if (!prot->memory_pressure)
1190 return false;
1191 return !!*prot->memory_pressure;
1192}
1193
1194
1195#ifdef CONFIG_PROC_FS
1196/* Called with local bh disabled */
1197extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1198extern int sock_prot_inuse_get(struct net *net, struct proto *proto);
1199#else
1200static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1201 int inc)
1202{
1203}
1204#endif
1205
1206
1207/* With per-bucket locks this operation is not-atomic, so that
1208 * this version is not worse.
1209 */
1210static inline void __sk_prot_rehash(struct sock *sk)
1211{
1212 sk->sk_prot->unhash(sk);
1213 sk->sk_prot->hash(sk);
1214}
1215
1216void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
1217
1218/* About 10 seconds */
1219#define SOCK_DESTROY_TIME (10*HZ)
1220
1221/* Sockets 0-1023 can't be bound to unless you are superuser */
1222#define PROT_SOCK 1024
1223
1224#define SHUTDOWN_MASK 3
1225#define RCV_SHUTDOWN 1
1226#define SEND_SHUTDOWN 2
1227
1228#define SOCK_SNDBUF_LOCK 1
1229#define SOCK_RCVBUF_LOCK 2
1230#define SOCK_BINDADDR_LOCK 4
1231#define SOCK_BINDPORT_LOCK 8
1232
1233/* sock_iocb: used to kick off async processing of socket ios */
1234struct sock_iocb {
1235 struct list_head list;
1236
1237 int flags;
1238 int size;
1239 struct socket *sock;
1240 struct sock *sk;
1241 struct scm_cookie *scm;
1242 struct msghdr *msg, async_msg;
1243 struct kiocb *kiocb;
1244};
1245
1246static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
1247{
1248 return (struct sock_iocb *)iocb->private;
1249}
1250
1251static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
1252{
1253 return si->kiocb;
1254}
1255
1256struct socket_alloc {
1257 struct socket socket;
1258 struct inode vfs_inode;
1259};
1260
1261static inline struct socket *SOCKET_I(struct inode *inode)
1262{
1263 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1264}
1265
1266static inline struct inode *SOCK_INODE(struct socket *socket)
1267{
1268 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1269}
1270
1271/*
1272 * Functions for memory accounting
1273 */
1274extern int __sk_mem_schedule(struct sock *sk, int size, int kind);
1275extern void __sk_mem_reclaim(struct sock *sk);
1276
1277#define SK_MEM_QUANTUM ((int)PAGE_SIZE)
1278#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1279#define SK_MEM_SEND 0
1280#define SK_MEM_RECV 1
1281
1282static inline int sk_mem_pages(int amt)
1283{
1284 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1285}
1286
1287static inline bool sk_has_account(struct sock *sk)
1288{
1289 /* return true if protocol supports memory accounting */
1290 return !!sk->sk_prot->memory_allocated;
1291}
1292
1293static inline bool sk_wmem_schedule(struct sock *sk, int size)
1294{
1295 if (!sk_has_account(sk))
1296 return true;
1297 return size <= sk->sk_forward_alloc ||
1298 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1299}
1300
1301static inline bool sk_rmem_schedule(struct sock *sk, int size)
1302{
1303 if (!sk_has_account(sk))
1304 return true;
1305 return size <= sk->sk_forward_alloc ||
1306 __sk_mem_schedule(sk, size, SK_MEM_RECV);
1307}
1308
1309static inline void sk_mem_reclaim(struct sock *sk)
1310{
1311 if (!sk_has_account(sk))
1312 return;
1313 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1314 __sk_mem_reclaim(sk);
1315}
1316
1317static inline void sk_mem_reclaim_partial(struct sock *sk)
1318{
1319 if (!sk_has_account(sk))
1320 return;
1321 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1322 __sk_mem_reclaim(sk);
1323}
1324
1325static inline void sk_mem_charge(struct sock *sk, int size)
1326{
1327 if (!sk_has_account(sk))
1328 return;
1329 sk->sk_forward_alloc -= size;
1330}
1331
1332static inline void sk_mem_uncharge(struct sock *sk, int size)
1333{
1334 if (!sk_has_account(sk))
1335 return;
1336 sk->sk_forward_alloc += size;
1337}
1338
1339static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1340{
1341 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1342 sk->sk_wmem_queued -= skb->truesize;
1343 sk_mem_uncharge(sk, skb->truesize);
1344 __kfree_skb(skb);
1345}
1346
1347/* Used by processes to "lock" a socket state, so that
1348 * interrupts and bottom half handlers won't change it
1349 * from under us. It essentially blocks any incoming
1350 * packets, so that we won't get any new data or any
1351 * packets that change the state of the socket.
1352 *
1353 * While locked, BH processing will add new packets to
1354 * the backlog queue. This queue is processed by the
1355 * owner of the socket lock right before it is released.
1356 *
1357 * Since ~2.3.5 it is also exclusive sleep lock serializing
1358 * accesses from user process context.
1359 */
1360#define sock_owned_by_user(sk) ((sk)->sk_lock.owned)
1361
1362/*
1363 * Macro so as to not evaluate some arguments when
1364 * lockdep is not enabled.
1365 *
1366 * Mark both the sk_lock and the sk_lock.slock as a
1367 * per-address-family lock class.
1368 */
1369#define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1370do { \
1371 sk->sk_lock.owned = 0; \
1372 init_waitqueue_head(&sk->sk_lock.wq); \
1373 spin_lock_init(&(sk)->sk_lock.slock); \
1374 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1375 sizeof((sk)->sk_lock)); \
1376 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1377 (skey), (sname)); \
1378 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1379} while (0)
1380
1381extern void lock_sock_nested(struct sock *sk, int subclass);
1382
1383static inline void lock_sock(struct sock *sk)
1384{
1385 lock_sock_nested(sk, 0);
1386}
1387
1388extern void release_sock(struct sock *sk);
1389
1390/* BH context may only use the following locking interface. */
1391#define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1392#define bh_lock_sock_nested(__sk) \
1393 spin_lock_nested(&((__sk)->sk_lock.slock), \
1394 SINGLE_DEPTH_NESTING)
1395#define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1396
1397extern bool lock_sock_fast(struct sock *sk);
1398/**
1399 * unlock_sock_fast - complement of lock_sock_fast
1400 * @sk: socket
1401 * @slow: slow mode
1402 *
1403 * fast unlock socket for user context.
1404 * If slow mode is on, we call regular release_sock()
1405 */
1406static inline void unlock_sock_fast(struct sock *sk, bool slow)
1407{
1408 if (slow)
1409 release_sock(sk);
1410 else
1411 spin_unlock_bh(&sk->sk_lock.slock);
1412}
1413
1414
1415extern struct sock *sk_alloc(struct net *net, int family,
1416 gfp_t priority,
1417 struct proto *prot);
1418extern void sk_free(struct sock *sk);
1419extern void sk_release_kernel(struct sock *sk);
1420extern struct sock *sk_clone_lock(const struct sock *sk,
1421 const gfp_t priority);
1422
1423extern struct sk_buff *sock_wmalloc(struct sock *sk,
1424 unsigned long size, int force,
1425 gfp_t priority);
1426extern struct sk_buff *sock_rmalloc(struct sock *sk,
1427 unsigned long size, int force,
1428 gfp_t priority);
1429extern void sock_wfree(struct sk_buff *skb);
1430extern void sock_rfree(struct sk_buff *skb);
1431
1432extern int sock_setsockopt(struct socket *sock, int level,
1433 int op, char __user *optval,
1434 unsigned int optlen);
1435
1436extern int sock_getsockopt(struct socket *sock, int level,
1437 int op, char __user *optval,
1438 int __user *optlen);
1439extern struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1440 unsigned long size,
1441 int noblock,
1442 int *errcode);
1443extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
1444 unsigned long header_len,
1445 unsigned long data_len,
1446 int noblock,
1447 int *errcode);
1448extern void *sock_kmalloc(struct sock *sk, int size,
1449 gfp_t priority);
1450extern void sock_kfree_s(struct sock *sk, void *mem, int size);
1451extern void sk_send_sigurg(struct sock *sk);
1452
1453#ifdef CONFIG_CGROUPS
1454extern void sock_update_classid(struct sock *sk);
1455#else
1456static inline void sock_update_classid(struct sock *sk)
1457{
1458}
1459#endif
1460
1461/*
1462 * Functions to fill in entries in struct proto_ops when a protocol
1463 * does not implement a particular function.
1464 */
1465extern int sock_no_bind(struct socket *,
1466 struct sockaddr *, int);
1467extern int sock_no_connect(struct socket *,
1468 struct sockaddr *, int, int);
1469extern int sock_no_socketpair(struct socket *,
1470 struct socket *);
1471extern int sock_no_accept(struct socket *,
1472 struct socket *, int);
1473extern int sock_no_getname(struct socket *,
1474 struct sockaddr *, int *, int);
1475extern unsigned int sock_no_poll(struct file *, struct socket *,
1476 struct poll_table_struct *);
1477extern int sock_no_ioctl(struct socket *, unsigned int,
1478 unsigned long);
1479extern int sock_no_listen(struct socket *, int);
1480extern int sock_no_shutdown(struct socket *, int);
1481extern int sock_no_getsockopt(struct socket *, int , int,
1482 char __user *, int __user *);
1483extern int sock_no_setsockopt(struct socket *, int, int,
1484 char __user *, unsigned int);
1485extern int sock_no_sendmsg(struct kiocb *, struct socket *,
1486 struct msghdr *, size_t);
1487extern int sock_no_recvmsg(struct kiocb *, struct socket *,
1488 struct msghdr *, size_t, int);
1489extern int sock_no_mmap(struct file *file,
1490 struct socket *sock,
1491 struct vm_area_struct *vma);
1492extern ssize_t sock_no_sendpage(struct socket *sock,
1493 struct page *page,
1494 int offset, size_t size,
1495 int flags);
1496
1497/*
1498 * Functions to fill in entries in struct proto_ops when a protocol
1499 * uses the inet style.
1500 */
1501extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
1502 char __user *optval, int __user *optlen);
1503extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1504 struct msghdr *msg, size_t size, int flags);
1505extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
1506 char __user *optval, unsigned int optlen);
1507extern int compat_sock_common_getsockopt(struct socket *sock, int level,
1508 int optname, char __user *optval, int __user *optlen);
1509extern int compat_sock_common_setsockopt(struct socket *sock, int level,
1510 int optname, char __user *optval, unsigned int optlen);
1511
1512extern void sk_common_release(struct sock *sk);
1513
1514/*
1515 * Default socket callbacks and setup code
1516 */
1517
1518/* Initialise core socket variables */
1519extern void sock_init_data(struct socket *sock, struct sock *sk);
1520
1521extern void sk_filter_release_rcu(struct rcu_head *rcu);
1522
1523/**
1524 * sk_filter_release - release a socket filter
1525 * @fp: filter to remove
1526 *
1527 * Remove a filter from a socket and release its resources.
1528 */
1529
1530static inline void sk_filter_release(struct sk_filter *fp)
1531{
1532 if (atomic_dec_and_test(&fp->refcnt))
1533 call_rcu(&fp->rcu, sk_filter_release_rcu);
1534}
1535
1536static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
1537{
1538 unsigned int size = sk_filter_len(fp);
1539
1540 atomic_sub(size, &sk->sk_omem_alloc);
1541 sk_filter_release(fp);
1542}
1543
1544static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
1545{
1546 atomic_inc(&fp->refcnt);
1547 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
1548}
1549
1550/*
1551 * Socket reference counting postulates.
1552 *
1553 * * Each user of socket SHOULD hold a reference count.
1554 * * Each access point to socket (an hash table bucket, reference from a list,
1555 * running timer, skb in flight MUST hold a reference count.
1556 * * When reference count hits 0, it means it will never increase back.
1557 * * When reference count hits 0, it means that no references from
1558 * outside exist to this socket and current process on current CPU
1559 * is last user and may/should destroy this socket.
1560 * * sk_free is called from any context: process, BH, IRQ. When
1561 * it is called, socket has no references from outside -> sk_free
1562 * may release descendant resources allocated by the socket, but
1563 * to the time when it is called, socket is NOT referenced by any
1564 * hash tables, lists etc.
1565 * * Packets, delivered from outside (from network or from another process)
1566 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1567 * when they sit in queue. Otherwise, packets will leak to hole, when
1568 * socket is looked up by one cpu and unhasing is made by another CPU.
1569 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1570 * (leak to backlog). Packet socket does all the processing inside
1571 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1572 * use separate SMP lock, so that they are prone too.
1573 */
1574
1575/* Ungrab socket and destroy it, if it was the last reference. */
1576static inline void sock_put(struct sock *sk)
1577{
1578 if (atomic_dec_and_test(&sk->sk_refcnt))
1579 sk_free(sk);
1580}
1581
1582extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1583 const int nested);
1584
1585static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1586{
1587 sk->sk_tx_queue_mapping = tx_queue;
1588}
1589
1590static inline void sk_tx_queue_clear(struct sock *sk)
1591{
1592 sk->sk_tx_queue_mapping = -1;
1593}
1594
1595static inline int sk_tx_queue_get(const struct sock *sk)
1596{
1597 return sk ? sk->sk_tx_queue_mapping : -1;
1598}
1599
1600static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1601{
1602 sk_tx_queue_clear(sk);
1603 sk->sk_socket = sock;
1604}
1605
1606static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1607{
1608 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1609 return &rcu_dereference_raw(sk->sk_wq)->wait;
1610}
1611/* Detach socket from process context.
1612 * Announce socket dead, detach it from wait queue and inode.
1613 * Note that parent inode held reference count on this struct sock,
1614 * we do not release it in this function, because protocol
1615 * probably wants some additional cleanups or even continuing
1616 * to work with this socket (TCP).
1617 */
1618static inline void sock_orphan(struct sock *sk)
1619{
1620 write_lock_bh(&sk->sk_callback_lock);
1621 sock_set_flag(sk, SOCK_DEAD);
1622 sk_set_socket(sk, NULL);
1623 sk->sk_wq = NULL;
1624 write_unlock_bh(&sk->sk_callback_lock);
1625}
1626
1627static inline void sock_graft(struct sock *sk, struct socket *parent)
1628{
1629 write_lock_bh(&sk->sk_callback_lock);
1630 sk->sk_wq = parent->wq;
1631 parent->sk = sk;
1632 sk_set_socket(sk, parent);
1633 security_sock_graft(sk, parent);
1634 write_unlock_bh(&sk->sk_callback_lock);
1635}
1636
1637extern int sock_i_uid(struct sock *sk);
1638extern unsigned long sock_i_ino(struct sock *sk);
1639
1640static inline struct dst_entry *
1641__sk_dst_get(struct sock *sk)
1642{
1643 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1644 lockdep_is_held(&sk->sk_lock.slock));
1645}
1646
1647static inline struct dst_entry *
1648sk_dst_get(struct sock *sk)
1649{
1650 struct dst_entry *dst;
1651
1652 rcu_read_lock();
1653 dst = rcu_dereference(sk->sk_dst_cache);
1654 if (dst)
1655 dst_hold(dst);
1656 rcu_read_unlock();
1657 return dst;
1658}
1659
1660extern void sk_reset_txq(struct sock *sk);
1661
1662static inline void dst_negative_advice(struct sock *sk)
1663{
1664 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1665
1666 if (dst && dst->ops->negative_advice) {
1667 ndst = dst->ops->negative_advice(dst);
1668
1669 if (ndst != dst) {
1670 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1671 sk_reset_txq(sk);
1672 }
1673 }
1674}
1675
1676static inline void
1677__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1678{
1679 struct dst_entry *old_dst;
1680
1681 sk_tx_queue_clear(sk);
1682 /*
1683 * This can be called while sk is owned by the caller only,
1684 * with no state that can be checked in a rcu_dereference_check() cond
1685 */
1686 old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1687 rcu_assign_pointer(sk->sk_dst_cache, dst);
1688 dst_release(old_dst);
1689}
1690
1691static inline void
1692sk_dst_set(struct sock *sk, struct dst_entry *dst)
1693{
1694 spin_lock(&sk->sk_dst_lock);
1695 __sk_dst_set(sk, dst);
1696 spin_unlock(&sk->sk_dst_lock);
1697}
1698
1699static inline void
1700__sk_dst_reset(struct sock *sk)
1701{
1702 __sk_dst_set(sk, NULL);
1703}
1704
1705static inline void
1706sk_dst_reset(struct sock *sk)
1707{
1708 spin_lock(&sk->sk_dst_lock);
1709 __sk_dst_reset(sk);
1710 spin_unlock(&sk->sk_dst_lock);
1711}
1712
1713extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1714
1715extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1716
1717static inline bool sk_can_gso(const struct sock *sk)
1718{
1719 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1720}
1721
1722extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1723
1724static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1725{
1726 sk->sk_route_nocaps |= flags;
1727 sk->sk_route_caps &= ~flags;
1728}
1729
1730static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1731 char __user *from, char *to,
1732 int copy, int offset)
1733{
1734 if (skb->ip_summed == CHECKSUM_NONE) {
1735 int err = 0;
1736 __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1737 if (err)
1738 return err;
1739 skb->csum = csum_block_add(skb->csum, csum, offset);
1740 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1741 if (!access_ok(VERIFY_READ, from, copy) ||
1742 __copy_from_user_nocache(to, from, copy))
1743 return -EFAULT;
1744 } else if (copy_from_user(to, from, copy))
1745 return -EFAULT;
1746
1747 return 0;
1748}
1749
1750static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1751 char __user *from, int copy)
1752{
1753 int err, offset = skb->len;
1754
1755 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1756 copy, offset);
1757 if (err)
1758 __skb_trim(skb, offset);
1759
1760 return err;
1761}
1762
1763static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1764 struct sk_buff *skb,
1765 struct page *page,
1766 int off, int copy)
1767{
1768 int err;
1769
1770 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1771 copy, skb->len);
1772 if (err)
1773 return err;
1774
1775 skb->len += copy;
1776 skb->data_len += copy;
1777 skb->truesize += copy;
1778 sk->sk_wmem_queued += copy;
1779 sk_mem_charge(sk, copy);
1780 return 0;
1781}
1782
1783static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1784 struct sk_buff *skb, struct page *page,
1785 int off, int copy)
1786{
1787 if (skb->ip_summed == CHECKSUM_NONE) {
1788 int err = 0;
1789 __wsum csum = csum_and_copy_from_user(from,
1790 page_address(page) + off,
1791 copy, 0, &err);
1792 if (err)
1793 return err;
1794 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1795 } else if (copy_from_user(page_address(page) + off, from, copy))
1796 return -EFAULT;
1797
1798 skb->len += copy;
1799 skb->data_len += copy;
1800 skb->truesize += copy;
1801 sk->sk_wmem_queued += copy;
1802 sk_mem_charge(sk, copy);
1803 return 0;
1804}
1805
1806/**
1807 * sk_wmem_alloc_get - returns write allocations
1808 * @sk: socket
1809 *
1810 * Returns sk_wmem_alloc minus initial offset of one
1811 */
1812static inline int sk_wmem_alloc_get(const struct sock *sk)
1813{
1814 return atomic_read(&sk->sk_wmem_alloc) - 1;
1815}
1816
1817/**
1818 * sk_rmem_alloc_get - returns read allocations
1819 * @sk: socket
1820 *
1821 * Returns sk_rmem_alloc
1822 */
1823static inline int sk_rmem_alloc_get(const struct sock *sk)
1824{
1825 return atomic_read(&sk->sk_rmem_alloc);
1826}
1827
1828/**
1829 * sk_has_allocations - check if allocations are outstanding
1830 * @sk: socket
1831 *
1832 * Returns true if socket has write or read allocations
1833 */
1834static inline bool sk_has_allocations(const struct sock *sk)
1835{
1836 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1837}
1838
1839/**
1840 * wq_has_sleeper - check if there are any waiting processes
1841 * @wq: struct socket_wq
1842 *
1843 * Returns true if socket_wq has waiting processes
1844 *
1845 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1846 * barrier call. They were added due to the race found within the tcp code.
1847 *
1848 * Consider following tcp code paths:
1849 *
1850 * CPU1 CPU2
1851 *
1852 * sys_select receive packet
1853 * ... ...
1854 * __add_wait_queue update tp->rcv_nxt
1855 * ... ...
1856 * tp->rcv_nxt check sock_def_readable
1857 * ... {
1858 * schedule rcu_read_lock();
1859 * wq = rcu_dereference(sk->sk_wq);
1860 * if (wq && waitqueue_active(&wq->wait))
1861 * wake_up_interruptible(&wq->wait)
1862 * ...
1863 * }
1864 *
1865 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1866 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
1867 * could then endup calling schedule and sleep forever if there are no more
1868 * data on the socket.
1869 *
1870 */
1871static inline bool wq_has_sleeper(struct socket_wq *wq)
1872{
1873 /* We need to be sure we are in sync with the
1874 * add_wait_queue modifications to the wait queue.
1875 *
1876 * This memory barrier is paired in the sock_poll_wait.
1877 */
1878 smp_mb();
1879 return wq && waitqueue_active(&wq->wait);
1880}
1881
1882/**
1883 * sock_poll_wait - place memory barrier behind the poll_wait call.
1884 * @filp: file
1885 * @wait_address: socket wait queue
1886 * @p: poll_table
1887 *
1888 * See the comments in the wq_has_sleeper function.
1889 */
1890static inline void sock_poll_wait(struct file *filp,
1891 wait_queue_head_t *wait_address, poll_table *p)
1892{
1893 if (!poll_does_not_wait(p) && wait_address) {
1894 poll_wait(filp, wait_address, p);
1895 /* We need to be sure we are in sync with the
1896 * socket flags modification.
1897 *
1898 * This memory barrier is paired in the wq_has_sleeper.
1899 */
1900 smp_mb();
1901 }
1902}
1903
1904/*
1905 * Queue a received datagram if it will fit. Stream and sequenced
1906 * protocols can't normally use this as they need to fit buffers in
1907 * and play with them.
1908 *
1909 * Inlined as it's very short and called for pretty much every
1910 * packet ever received.
1911 */
1912
1913static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1914{
1915 skb_orphan(skb);
1916 skb->sk = sk;
1917 skb->destructor = sock_wfree;
1918 /*
1919 * We used to take a refcount on sk, but following operation
1920 * is enough to guarantee sk_free() wont free this sock until
1921 * all in-flight packets are completed
1922 */
1923 atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1924}
1925
1926static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1927{
1928 skb_orphan(skb);
1929 skb->sk = sk;
1930 skb->destructor = sock_rfree;
1931 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1932 sk_mem_charge(sk, skb->truesize);
1933}
1934
1935extern void sk_reset_timer(struct sock *sk, struct timer_list *timer,
1936 unsigned long expires);
1937
1938extern void sk_stop_timer(struct sock *sk, struct timer_list *timer);
1939
1940extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1941
1942extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
1943
1944/*
1945 * Recover an error report and clear atomically
1946 */
1947
1948static inline int sock_error(struct sock *sk)
1949{
1950 int err;
1951 if (likely(!sk->sk_err))
1952 return 0;
1953 err = xchg(&sk->sk_err, 0);
1954 return -err;
1955}
1956
1957static inline unsigned long sock_wspace(struct sock *sk)
1958{
1959 int amt = 0;
1960
1961 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1962 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1963 if (amt < 0)
1964 amt = 0;
1965 }
1966 return amt;
1967}
1968
1969static inline void sk_wake_async(struct sock *sk, int how, int band)
1970{
1971 if (sock_flag(sk, SOCK_FASYNC))
1972 sock_wake_async(sk->sk_socket, how, band);
1973}
1974
1975#define SOCK_MIN_SNDBUF 2048
1976/*
1977 * Since sk_rmem_alloc sums skb->truesize, even a small frame might need
1978 * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak
1979 */
1980#define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff))
1981
1982static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1983{
1984 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1985 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
1986 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1987 }
1988}
1989
1990struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
1991
1992static inline struct page *sk_stream_alloc_page(struct sock *sk)
1993{
1994 struct page *page = NULL;
1995
1996 page = alloc_pages(sk->sk_allocation, 0);
1997 if (!page) {
1998 sk_enter_memory_pressure(sk);
1999 sk_stream_moderate_sndbuf(sk);
2000 }
2001 return page;
2002}
2003
2004/*
2005 * Default write policy as shown to user space via poll/select/SIGIO
2006 */
2007static inline bool sock_writeable(const struct sock *sk)
2008{
2009 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2010}
2011
2012static inline gfp_t gfp_any(void)
2013{
2014 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2015}
2016
2017static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2018{
2019 return noblock ? 0 : sk->sk_rcvtimeo;
2020}
2021
2022static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2023{
2024 return noblock ? 0 : sk->sk_sndtimeo;
2025}
2026
2027static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2028{
2029 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2030}
2031
2032/* Alas, with timeout socket operations are not restartable.
2033 * Compare this to poll().
2034 */
2035static inline int sock_intr_errno(long timeo)
2036{
2037 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2038}
2039
2040extern void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2041 struct sk_buff *skb);
2042extern void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2043 struct sk_buff *skb);
2044
2045static inline void
2046sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2047{
2048 ktime_t kt = skb->tstamp;
2049 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2050
2051 /*
2052 * generate control messages if
2053 * - receive time stamping in software requested (SOCK_RCVTSTAMP
2054 * or SOCK_TIMESTAMPING_RX_SOFTWARE)
2055 * - software time stamp available and wanted
2056 * (SOCK_TIMESTAMPING_SOFTWARE)
2057 * - hardware time stamps available and wanted
2058 * (SOCK_TIMESTAMPING_SYS_HARDWARE or
2059 * SOCK_TIMESTAMPING_RAW_HARDWARE)
2060 */
2061 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2062 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
2063 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
2064 (hwtstamps->hwtstamp.tv64 &&
2065 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
2066 (hwtstamps->syststamp.tv64 &&
2067 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
2068 __sock_recv_timestamp(msg, sk, skb);
2069 else
2070 sk->sk_stamp = kt;
2071
2072 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2073 __sock_recv_wifi_status(msg, sk, skb);
2074}
2075
2076extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2077 struct sk_buff *skb);
2078
2079static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2080 struct sk_buff *skb)
2081{
2082#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2083 (1UL << SOCK_RCVTSTAMP) | \
2084 (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
2085 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \
2086 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \
2087 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE))
2088
2089 if (sk->sk_flags & FLAGS_TS_OR_DROPS)
2090 __sock_recv_ts_and_drops(msg, sk, skb);
2091 else
2092 sk->sk_stamp = skb->tstamp;
2093}
2094
2095/**
2096 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2097 * @sk: socket sending this packet
2098 * @tx_flags: filled with instructions for time stamping
2099 *
2100 * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if
2101 * parameters are invalid.
2102 */
2103extern int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
2104
2105/**
2106 * sk_eat_skb - Release a skb if it is no longer needed
2107 * @sk: socket to eat this skb from
2108 * @skb: socket buffer to eat
2109 * @copied_early: flag indicating whether DMA operations copied this data early
2110 *
2111 * This routine must be called with interrupts disabled or with the socket
2112 * locked so that the sk_buff queue operation is ok.
2113*/
2114#ifdef CONFIG_NET_DMA
2115static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2116{
2117 __skb_unlink(skb, &sk->sk_receive_queue);
2118 if (!copied_early)
2119 __kfree_skb(skb);
2120 else
2121 __skb_queue_tail(&sk->sk_async_wait_queue, skb);
2122}
2123#else
2124static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2125{
2126 __skb_unlink(skb, &sk->sk_receive_queue);
2127 __kfree_skb(skb);
2128}
2129#endif
2130
2131static inline
2132struct net *sock_net(const struct sock *sk)
2133{
2134 return read_pnet(&sk->sk_net);
2135}
2136
2137static inline
2138void sock_net_set(struct sock *sk, struct net *net)
2139{
2140 write_pnet(&sk->sk_net, net);
2141}
2142
2143/*
2144 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
2145 * They should not hold a reference to a namespace in order to allow
2146 * to stop it.
2147 * Sockets after sk_change_net should be released using sk_release_kernel
2148 */
2149static inline void sk_change_net(struct sock *sk, struct net *net)
2150{
2151 put_net(sock_net(sk));
2152 sock_net_set(sk, hold_net(net));
2153}
2154
2155static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2156{
2157 if (unlikely(skb->sk)) {
2158 struct sock *sk = skb->sk;
2159
2160 skb->destructor = NULL;
2161 skb->sk = NULL;
2162 return sk;
2163 }
2164 return NULL;
2165}
2166
2167extern void sock_enable_timestamp(struct sock *sk, int flag);
2168extern int sock_get_timestamp(struct sock *, struct timeval __user *);
2169extern int sock_get_timestampns(struct sock *, struct timespec __user *);
2170
2171/*
2172 * Enable debug/info messages
2173 */
2174extern int net_msg_warn;
2175#define NETDEBUG(fmt, args...) \
2176 do { if (net_msg_warn) printk(fmt,##args); } while (0)
2177
2178#define LIMIT_NETDEBUG(fmt, args...) \
2179 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
2180
2181extern __u32 sysctl_wmem_max;
2182extern __u32 sysctl_rmem_max;
2183
2184extern void sk_init(void);
2185
2186extern int sysctl_optmem_max;
2187
2188extern __u32 sysctl_wmem_default;
2189extern __u32 sysctl_rmem_default;
2190
2191#endif /* _SOCK_H */