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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/module.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
58#include <linux/filter.h>
59#include <linux/rculist_nulls.h>
60#include <linux/poll.h>
61
62#include <linux/atomic.h>
63#include <net/dst.h>
64#include <net/checksum.h>
65
66/*
67 * This structure really needs to be cleaned up.
68 * Most of it is for TCP, and not used by any of
69 * the other protocols.
70 */
71
72/* Define this to get the SOCK_DBG debugging facility. */
73#define SOCK_DEBUGGING
74#ifdef SOCK_DEBUGGING
75#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
76 printk(KERN_DEBUG msg); } while (0)
77#else
78/* Validate arguments and do nothing */
79static inline void __attribute__ ((format (printf, 2, 3)))
80SOCK_DEBUG(struct sock *sk, const char *msg, ...)
81{
82}
83#endif
84
85/* This is the per-socket lock. The spinlock provides a synchronization
86 * between user contexts and software interrupt processing, whereas the
87 * mini-semaphore synchronizes multiple users amongst themselves.
88 */
89typedef struct {
90 spinlock_t slock;
91 int owned;
92 wait_queue_head_t wq;
93 /*
94 * We express the mutex-alike socket_lock semantics
95 * to the lock validator by explicitly managing
96 * the slock as a lock variant (in addition to
97 * the slock itself):
98 */
99#ifdef CONFIG_DEBUG_LOCK_ALLOC
100 struct lockdep_map dep_map;
101#endif
102} socket_lock_t;
103
104struct sock;
105struct proto;
106struct net;
107
108/**
109 * struct sock_common - minimal network layer representation of sockets
110 * @skc_daddr: Foreign IPv4 addr
111 * @skc_rcv_saddr: Bound local IPv4 addr
112 * @skc_hash: hash value used with various protocol lookup tables
113 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
114 * @skc_family: network address family
115 * @skc_state: Connection state
116 * @skc_reuse: %SO_REUSEADDR setting
117 * @skc_bound_dev_if: bound device index if != 0
118 * @skc_bind_node: bind hash linkage for various protocol lookup tables
119 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
120 * @skc_prot: protocol handlers inside a network family
121 * @skc_net: reference to the network namespace of this socket
122 * @skc_node: main hash linkage for various protocol lookup tables
123 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
124 * @skc_tx_queue_mapping: tx queue number for this connection
125 * @skc_refcnt: reference count
126 *
127 * This is the minimal network layer representation of sockets, the header
128 * for struct sock and struct inet_timewait_sock.
129 */
130struct sock_common {
131 /* skc_daddr and skc_rcv_saddr must be grouped :
132 * cf INET_MATCH() and INET_TW_MATCH()
133 */
134 __be32 skc_daddr;
135 __be32 skc_rcv_saddr;
136
137 union {
138 unsigned int skc_hash;
139 __u16 skc_u16hashes[2];
140 };
141 unsigned short skc_family;
142 volatile unsigned char skc_state;
143 unsigned char skc_reuse;
144 int skc_bound_dev_if;
145 union {
146 struct hlist_node skc_bind_node;
147 struct hlist_nulls_node skc_portaddr_node;
148 };
149 struct proto *skc_prot;
150#ifdef CONFIG_NET_NS
151 struct net *skc_net;
152#endif
153 /*
154 * fields between dontcopy_begin/dontcopy_end
155 * are not copied in sock_copy()
156 */
157 /* private: */
158 int skc_dontcopy_begin[0];
159 /* public: */
160 union {
161 struct hlist_node skc_node;
162 struct hlist_nulls_node skc_nulls_node;
163 };
164 int skc_tx_queue_mapping;
165 atomic_t skc_refcnt;
166 /* private: */
167 int skc_dontcopy_end[0];
168 /* public: */
169};
170
171/**
172 * struct sock - network layer representation of sockets
173 * @__sk_common: shared layout with inet_timewait_sock
174 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
175 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
176 * @sk_lock: synchronizer
177 * @sk_rcvbuf: size of receive buffer in bytes
178 * @sk_wq: sock wait queue and async head
179 * @sk_dst_cache: destination cache
180 * @sk_dst_lock: destination cache lock
181 * @sk_policy: flow policy
182 * @sk_receive_queue: incoming packets
183 * @sk_wmem_alloc: transmit queue bytes committed
184 * @sk_write_queue: Packet sending queue
185 * @sk_async_wait_queue: DMA copied packets
186 * @sk_omem_alloc: "o" is "option" or "other"
187 * @sk_wmem_queued: persistent queue size
188 * @sk_forward_alloc: space allocated forward
189 * @sk_allocation: allocation mode
190 * @sk_sndbuf: size of send buffer in bytes
191 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
192 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
193 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
194 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
195 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
196 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
197 * @sk_gso_max_size: Maximum GSO segment size to build
198 * @sk_lingertime: %SO_LINGER l_linger setting
199 * @sk_backlog: always used with the per-socket spinlock held
200 * @sk_callback_lock: used with the callbacks in the end of this struct
201 * @sk_error_queue: rarely used
202 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
203 * IPV6_ADDRFORM for instance)
204 * @sk_err: last error
205 * @sk_err_soft: errors that don't cause failure but are the cause of a
206 * persistent failure not just 'timed out'
207 * @sk_drops: raw/udp drops counter
208 * @sk_ack_backlog: current listen backlog
209 * @sk_max_ack_backlog: listen backlog set in listen()
210 * @sk_priority: %SO_PRIORITY setting
211 * @sk_type: socket type (%SOCK_STREAM, etc)
212 * @sk_protocol: which protocol this socket belongs in this network family
213 * @sk_peer_pid: &struct pid for this socket's peer
214 * @sk_peer_cred: %SO_PEERCRED setting
215 * @sk_rcvlowat: %SO_RCVLOWAT setting
216 * @sk_rcvtimeo: %SO_RCVTIMEO setting
217 * @sk_sndtimeo: %SO_SNDTIMEO setting
218 * @sk_rxhash: flow hash received from netif layer
219 * @sk_filter: socket filtering instructions
220 * @sk_protinfo: private area, net family specific, when not using slab
221 * @sk_timer: sock cleanup timer
222 * @sk_stamp: time stamp of last packet received
223 * @sk_socket: Identd and reporting IO signals
224 * @sk_user_data: RPC layer private data
225 * @sk_sndmsg_page: cached page for sendmsg
226 * @sk_sndmsg_off: cached offset for sendmsg
227 * @sk_send_head: front of stuff to transmit
228 * @sk_security: used by security modules
229 * @sk_mark: generic packet mark
230 * @sk_classid: this socket's cgroup classid
231 * @sk_write_pending: a write to stream socket waits to start
232 * @sk_state_change: callback to indicate change in the state of the sock
233 * @sk_data_ready: callback to indicate there is data to be processed
234 * @sk_write_space: callback to indicate there is bf sending space available
235 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
236 * @sk_backlog_rcv: callback to process the backlog
237 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
238 */
239struct sock {
240 /*
241 * Now struct inet_timewait_sock also uses sock_common, so please just
242 * don't add nothing before this first member (__sk_common) --acme
243 */
244 struct sock_common __sk_common;
245#define sk_node __sk_common.skc_node
246#define sk_nulls_node __sk_common.skc_nulls_node
247#define sk_refcnt __sk_common.skc_refcnt
248#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
249
250#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
251#define sk_dontcopy_end __sk_common.skc_dontcopy_end
252#define sk_hash __sk_common.skc_hash
253#define sk_family __sk_common.skc_family
254#define sk_state __sk_common.skc_state
255#define sk_reuse __sk_common.skc_reuse
256#define sk_bound_dev_if __sk_common.skc_bound_dev_if
257#define sk_bind_node __sk_common.skc_bind_node
258#define sk_prot __sk_common.skc_prot
259#define sk_net __sk_common.skc_net
260 socket_lock_t sk_lock;
261 struct sk_buff_head sk_receive_queue;
262 /*
263 * The backlog queue is special, it is always used with
264 * the per-socket spinlock held and requires low latency
265 * access. Therefore we special case it's implementation.
266 * Note : rmem_alloc is in this structure to fill a hole
267 * on 64bit arches, not because its logically part of
268 * backlog.
269 */
270 struct {
271 atomic_t rmem_alloc;
272 int len;
273 struct sk_buff *head;
274 struct sk_buff *tail;
275 } sk_backlog;
276#define sk_rmem_alloc sk_backlog.rmem_alloc
277 int sk_forward_alloc;
278#ifdef CONFIG_RPS
279 __u32 sk_rxhash;
280#endif
281 atomic_t sk_drops;
282 int sk_rcvbuf;
283
284 struct sk_filter __rcu *sk_filter;
285 struct socket_wq __rcu *sk_wq;
286
287#ifdef CONFIG_NET_DMA
288 struct sk_buff_head sk_async_wait_queue;
289#endif
290
291#ifdef CONFIG_XFRM
292 struct xfrm_policy *sk_policy[2];
293#endif
294 unsigned long sk_flags;
295 struct dst_entry *sk_dst_cache;
296 spinlock_t sk_dst_lock;
297 atomic_t sk_wmem_alloc;
298 atomic_t sk_omem_alloc;
299 int sk_sndbuf;
300 struct sk_buff_head sk_write_queue;
301 kmemcheck_bitfield_begin(flags);
302 unsigned int sk_shutdown : 2,
303 sk_no_check : 2,
304 sk_userlocks : 4,
305 sk_protocol : 8,
306 sk_type : 16;
307 kmemcheck_bitfield_end(flags);
308 int sk_wmem_queued;
309 gfp_t sk_allocation;
310 int sk_route_caps;
311 int sk_route_nocaps;
312 int sk_gso_type;
313 unsigned int sk_gso_max_size;
314 int sk_rcvlowat;
315 unsigned long sk_lingertime;
316 struct sk_buff_head sk_error_queue;
317 struct proto *sk_prot_creator;
318 rwlock_t sk_callback_lock;
319 int sk_err,
320 sk_err_soft;
321 unsigned short sk_ack_backlog;
322 unsigned short sk_max_ack_backlog;
323 __u32 sk_priority;
324 struct pid *sk_peer_pid;
325 const struct cred *sk_peer_cred;
326 long sk_rcvtimeo;
327 long sk_sndtimeo;
328 void *sk_protinfo;
329 struct timer_list sk_timer;
330 ktime_t sk_stamp;
331 struct socket *sk_socket;
332 void *sk_user_data;
333 struct page *sk_sndmsg_page;
334 struct sk_buff *sk_send_head;
335 __u32 sk_sndmsg_off;
336 int sk_write_pending;
337#ifdef CONFIG_SECURITY
338 void *sk_security;
339#endif
340 __u32 sk_mark;
341 u32 sk_classid;
342 void (*sk_state_change)(struct sock *sk);
343 void (*sk_data_ready)(struct sock *sk, int bytes);
344 void (*sk_write_space)(struct sock *sk);
345 void (*sk_error_report)(struct sock *sk);
346 int (*sk_backlog_rcv)(struct sock *sk,
347 struct sk_buff *skb);
348 void (*sk_destruct)(struct sock *sk);
349};
350
351/*
352 * Hashed lists helper routines
353 */
354static inline struct sock *sk_entry(const struct hlist_node *node)
355{
356 return hlist_entry(node, struct sock, sk_node);
357}
358
359static inline struct sock *__sk_head(const struct hlist_head *head)
360{
361 return hlist_entry(head->first, struct sock, sk_node);
362}
363
364static inline struct sock *sk_head(const struct hlist_head *head)
365{
366 return hlist_empty(head) ? NULL : __sk_head(head);
367}
368
369static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
370{
371 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
372}
373
374static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
375{
376 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
377}
378
379static inline struct sock *sk_next(const struct sock *sk)
380{
381 return sk->sk_node.next ?
382 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
383}
384
385static inline struct sock *sk_nulls_next(const struct sock *sk)
386{
387 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
388 hlist_nulls_entry(sk->sk_nulls_node.next,
389 struct sock, sk_nulls_node) :
390 NULL;
391}
392
393static inline int sk_unhashed(const struct sock *sk)
394{
395 return hlist_unhashed(&sk->sk_node);
396}
397
398static inline int sk_hashed(const struct sock *sk)
399{
400 return !sk_unhashed(sk);
401}
402
403static __inline__ void sk_node_init(struct hlist_node *node)
404{
405 node->pprev = NULL;
406}
407
408static __inline__ void sk_nulls_node_init(struct hlist_nulls_node *node)
409{
410 node->pprev = NULL;
411}
412
413static __inline__ void __sk_del_node(struct sock *sk)
414{
415 __hlist_del(&sk->sk_node);
416}
417
418/* NB: equivalent to hlist_del_init_rcu */
419static __inline__ int __sk_del_node_init(struct sock *sk)
420{
421 if (sk_hashed(sk)) {
422 __sk_del_node(sk);
423 sk_node_init(&sk->sk_node);
424 return 1;
425 }
426 return 0;
427}
428
429/* Grab socket reference count. This operation is valid only
430 when sk is ALREADY grabbed f.e. it is found in hash table
431 or a list and the lookup is made under lock preventing hash table
432 modifications.
433 */
434
435static inline void sock_hold(struct sock *sk)
436{
437 atomic_inc(&sk->sk_refcnt);
438}
439
440/* Ungrab socket in the context, which assumes that socket refcnt
441 cannot hit zero, f.e. it is true in context of any socketcall.
442 */
443static inline void __sock_put(struct sock *sk)
444{
445 atomic_dec(&sk->sk_refcnt);
446}
447
448static __inline__ int sk_del_node_init(struct sock *sk)
449{
450 int rc = __sk_del_node_init(sk);
451
452 if (rc) {
453 /* paranoid for a while -acme */
454 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
455 __sock_put(sk);
456 }
457 return rc;
458}
459#define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
460
461static __inline__ int __sk_nulls_del_node_init_rcu(struct sock *sk)
462{
463 if (sk_hashed(sk)) {
464 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
465 return 1;
466 }
467 return 0;
468}
469
470static __inline__ int sk_nulls_del_node_init_rcu(struct sock *sk)
471{
472 int rc = __sk_nulls_del_node_init_rcu(sk);
473
474 if (rc) {
475 /* paranoid for a while -acme */
476 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
477 __sock_put(sk);
478 }
479 return rc;
480}
481
482static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list)
483{
484 hlist_add_head(&sk->sk_node, list);
485}
486
487static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list)
488{
489 sock_hold(sk);
490 __sk_add_node(sk, list);
491}
492
493static __inline__ void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
494{
495 sock_hold(sk);
496 hlist_add_head_rcu(&sk->sk_node, list);
497}
498
499static __inline__ void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
500{
501 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
502}
503
504static __inline__ void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
505{
506 sock_hold(sk);
507 __sk_nulls_add_node_rcu(sk, list);
508}
509
510static __inline__ void __sk_del_bind_node(struct sock *sk)
511{
512 __hlist_del(&sk->sk_bind_node);
513}
514
515static __inline__ void sk_add_bind_node(struct sock *sk,
516 struct hlist_head *list)
517{
518 hlist_add_head(&sk->sk_bind_node, list);
519}
520
521#define sk_for_each(__sk, node, list) \
522 hlist_for_each_entry(__sk, node, list, sk_node)
523#define sk_for_each_rcu(__sk, node, list) \
524 hlist_for_each_entry_rcu(__sk, node, list, sk_node)
525#define sk_nulls_for_each(__sk, node, list) \
526 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
527#define sk_nulls_for_each_rcu(__sk, node, list) \
528 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
529#define sk_for_each_from(__sk, node) \
530 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
531 hlist_for_each_entry_from(__sk, node, sk_node)
532#define sk_nulls_for_each_from(__sk, node) \
533 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
534 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
535#define sk_for_each_safe(__sk, node, tmp, list) \
536 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
537#define sk_for_each_bound(__sk, node, list) \
538 hlist_for_each_entry(__sk, node, list, sk_bind_node)
539
540/* Sock flags */
541enum sock_flags {
542 SOCK_DEAD,
543 SOCK_DONE,
544 SOCK_URGINLINE,
545 SOCK_KEEPOPEN,
546 SOCK_LINGER,
547 SOCK_DESTROY,
548 SOCK_BROADCAST,
549 SOCK_TIMESTAMP,
550 SOCK_ZAPPED,
551 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
552 SOCK_DBG, /* %SO_DEBUG setting */
553 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
554 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
555 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
556 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
557 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */
558 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */
559 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */
560 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
561 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */
562 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
563 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
564 SOCK_FASYNC, /* fasync() active */
565 SOCK_RXQ_OVFL,
566 SOCK_ZEROCOPY, /* buffers from userspace */
567};
568
569static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
570{
571 nsk->sk_flags = osk->sk_flags;
572}
573
574static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
575{
576 __set_bit(flag, &sk->sk_flags);
577}
578
579static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
580{
581 __clear_bit(flag, &sk->sk_flags);
582}
583
584static inline int sock_flag(struct sock *sk, enum sock_flags flag)
585{
586 return test_bit(flag, &sk->sk_flags);
587}
588
589static inline void sk_acceptq_removed(struct sock *sk)
590{
591 sk->sk_ack_backlog--;
592}
593
594static inline void sk_acceptq_added(struct sock *sk)
595{
596 sk->sk_ack_backlog++;
597}
598
599static inline int sk_acceptq_is_full(struct sock *sk)
600{
601 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
602}
603
604/*
605 * Compute minimal free write space needed to queue new packets.
606 */
607static inline int sk_stream_min_wspace(struct sock *sk)
608{
609 return sk->sk_wmem_queued >> 1;
610}
611
612static inline int sk_stream_wspace(struct sock *sk)
613{
614 return sk->sk_sndbuf - sk->sk_wmem_queued;
615}
616
617extern void sk_stream_write_space(struct sock *sk);
618
619static inline int sk_stream_memory_free(struct sock *sk)
620{
621 return sk->sk_wmem_queued < sk->sk_sndbuf;
622}
623
624/* OOB backlog add */
625static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
626{
627 /* dont let skb dst not refcounted, we are going to leave rcu lock */
628 skb_dst_force(skb);
629
630 if (!sk->sk_backlog.tail)
631 sk->sk_backlog.head = skb;
632 else
633 sk->sk_backlog.tail->next = skb;
634
635 sk->sk_backlog.tail = skb;
636 skb->next = NULL;
637}
638
639/*
640 * Take into account size of receive queue and backlog queue
641 */
642static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb)
643{
644 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
645
646 return qsize + skb->truesize > sk->sk_rcvbuf;
647}
648
649/* The per-socket spinlock must be held here. */
650static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb)
651{
652 if (sk_rcvqueues_full(sk, skb))
653 return -ENOBUFS;
654
655 __sk_add_backlog(sk, skb);
656 sk->sk_backlog.len += skb->truesize;
657 return 0;
658}
659
660static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
661{
662 return sk->sk_backlog_rcv(sk, skb);
663}
664
665static inline void sock_rps_record_flow(const struct sock *sk)
666{
667#ifdef CONFIG_RPS
668 struct rps_sock_flow_table *sock_flow_table;
669
670 rcu_read_lock();
671 sock_flow_table = rcu_dereference(rps_sock_flow_table);
672 rps_record_sock_flow(sock_flow_table, sk->sk_rxhash);
673 rcu_read_unlock();
674#endif
675}
676
677static inline void sock_rps_reset_flow(const struct sock *sk)
678{
679#ifdef CONFIG_RPS
680 struct rps_sock_flow_table *sock_flow_table;
681
682 rcu_read_lock();
683 sock_flow_table = rcu_dereference(rps_sock_flow_table);
684 rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash);
685 rcu_read_unlock();
686#endif
687}
688
689static inline void sock_rps_save_rxhash(struct sock *sk, u32 rxhash)
690{
691#ifdef CONFIG_RPS
692 if (unlikely(sk->sk_rxhash != rxhash)) {
693 sock_rps_reset_flow(sk);
694 sk->sk_rxhash = rxhash;
695 }
696#endif
697}
698
699#define sk_wait_event(__sk, __timeo, __condition) \
700 ({ int __rc; \
701 release_sock(__sk); \
702 __rc = __condition; \
703 if (!__rc) { \
704 *(__timeo) = schedule_timeout(*(__timeo)); \
705 } \
706 lock_sock(__sk); \
707 __rc = __condition; \
708 __rc; \
709 })
710
711extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
712extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
713extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
714extern int sk_stream_error(struct sock *sk, int flags, int err);
715extern void sk_stream_kill_queues(struct sock *sk);
716
717extern int sk_wait_data(struct sock *sk, long *timeo);
718
719struct request_sock_ops;
720struct timewait_sock_ops;
721struct inet_hashinfo;
722struct raw_hashinfo;
723
724/* Networking protocol blocks we attach to sockets.
725 * socket layer -> transport layer interface
726 * transport -> network interface is defined by struct inet_proto
727 */
728struct proto {
729 void (*close)(struct sock *sk,
730 long timeout);
731 int (*connect)(struct sock *sk,
732 struct sockaddr *uaddr,
733 int addr_len);
734 int (*disconnect)(struct sock *sk, int flags);
735
736 struct sock * (*accept) (struct sock *sk, int flags, int *err);
737
738 int (*ioctl)(struct sock *sk, int cmd,
739 unsigned long arg);
740 int (*init)(struct sock *sk);
741 void (*destroy)(struct sock *sk);
742 void (*shutdown)(struct sock *sk, int how);
743 int (*setsockopt)(struct sock *sk, int level,
744 int optname, char __user *optval,
745 unsigned int optlen);
746 int (*getsockopt)(struct sock *sk, int level,
747 int optname, char __user *optval,
748 int __user *option);
749#ifdef CONFIG_COMPAT
750 int (*compat_setsockopt)(struct sock *sk,
751 int level,
752 int optname, char __user *optval,
753 unsigned int optlen);
754 int (*compat_getsockopt)(struct sock *sk,
755 int level,
756 int optname, char __user *optval,
757 int __user *option);
758 int (*compat_ioctl)(struct sock *sk,
759 unsigned int cmd, unsigned long arg);
760#endif
761 int (*sendmsg)(struct kiocb *iocb, struct sock *sk,
762 struct msghdr *msg, size_t len);
763 int (*recvmsg)(struct kiocb *iocb, struct sock *sk,
764 struct msghdr *msg,
765 size_t len, int noblock, int flags,
766 int *addr_len);
767 int (*sendpage)(struct sock *sk, struct page *page,
768 int offset, size_t size, int flags);
769 int (*bind)(struct sock *sk,
770 struct sockaddr *uaddr, int addr_len);
771
772 int (*backlog_rcv) (struct sock *sk,
773 struct sk_buff *skb);
774
775 /* Keeping track of sk's, looking them up, and port selection methods. */
776 void (*hash)(struct sock *sk);
777 void (*unhash)(struct sock *sk);
778 void (*rehash)(struct sock *sk);
779 int (*get_port)(struct sock *sk, unsigned short snum);
780 void (*clear_sk)(struct sock *sk, int size);
781
782 /* Keeping track of sockets in use */
783#ifdef CONFIG_PROC_FS
784 unsigned int inuse_idx;
785#endif
786
787 /* Memory pressure */
788 void (*enter_memory_pressure)(struct sock *sk);
789 atomic_long_t *memory_allocated; /* Current allocated memory. */
790 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
791 /*
792 * Pressure flag: try to collapse.
793 * Technical note: it is used by multiple contexts non atomically.
794 * All the __sk_mem_schedule() is of this nature: accounting
795 * is strict, actions are advisory and have some latency.
796 */
797 int *memory_pressure;
798 long *sysctl_mem;
799 int *sysctl_wmem;
800 int *sysctl_rmem;
801 int max_header;
802 bool no_autobind;
803
804 struct kmem_cache *slab;
805 unsigned int obj_size;
806 int slab_flags;
807
808 struct percpu_counter *orphan_count;
809
810 struct request_sock_ops *rsk_prot;
811 struct timewait_sock_ops *twsk_prot;
812
813 union {
814 struct inet_hashinfo *hashinfo;
815 struct udp_table *udp_table;
816 struct raw_hashinfo *raw_hash;
817 } h;
818
819 struct module *owner;
820
821 char name[32];
822
823 struct list_head node;
824#ifdef SOCK_REFCNT_DEBUG
825 atomic_t socks;
826#endif
827};
828
829extern int proto_register(struct proto *prot, int alloc_slab);
830extern void proto_unregister(struct proto *prot);
831
832#ifdef SOCK_REFCNT_DEBUG
833static inline void sk_refcnt_debug_inc(struct sock *sk)
834{
835 atomic_inc(&sk->sk_prot->socks);
836}
837
838static inline void sk_refcnt_debug_dec(struct sock *sk)
839{
840 atomic_dec(&sk->sk_prot->socks);
841 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
842 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
843}
844
845static inline void sk_refcnt_debug_release(const struct sock *sk)
846{
847 if (atomic_read(&sk->sk_refcnt) != 1)
848 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
849 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
850}
851#else /* SOCK_REFCNT_DEBUG */
852#define sk_refcnt_debug_inc(sk) do { } while (0)
853#define sk_refcnt_debug_dec(sk) do { } while (0)
854#define sk_refcnt_debug_release(sk) do { } while (0)
855#endif /* SOCK_REFCNT_DEBUG */
856
857
858#ifdef CONFIG_PROC_FS
859/* Called with local bh disabled */
860extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
861extern int sock_prot_inuse_get(struct net *net, struct proto *proto);
862#else
863static void inline sock_prot_inuse_add(struct net *net, struct proto *prot,
864 int inc)
865{
866}
867#endif
868
869
870/* With per-bucket locks this operation is not-atomic, so that
871 * this version is not worse.
872 */
873static inline void __sk_prot_rehash(struct sock *sk)
874{
875 sk->sk_prot->unhash(sk);
876 sk->sk_prot->hash(sk);
877}
878
879void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
880
881/* About 10 seconds */
882#define SOCK_DESTROY_TIME (10*HZ)
883
884/* Sockets 0-1023 can't be bound to unless you are superuser */
885#define PROT_SOCK 1024
886
887#define SHUTDOWN_MASK 3
888#define RCV_SHUTDOWN 1
889#define SEND_SHUTDOWN 2
890
891#define SOCK_SNDBUF_LOCK 1
892#define SOCK_RCVBUF_LOCK 2
893#define SOCK_BINDADDR_LOCK 4
894#define SOCK_BINDPORT_LOCK 8
895
896/* sock_iocb: used to kick off async processing of socket ios */
897struct sock_iocb {
898 struct list_head list;
899
900 int flags;
901 int size;
902 struct socket *sock;
903 struct sock *sk;
904 struct scm_cookie *scm;
905 struct msghdr *msg, async_msg;
906 struct kiocb *kiocb;
907};
908
909static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
910{
911 return (struct sock_iocb *)iocb->private;
912}
913
914static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
915{
916 return si->kiocb;
917}
918
919struct socket_alloc {
920 struct socket socket;
921 struct inode vfs_inode;
922};
923
924static inline struct socket *SOCKET_I(struct inode *inode)
925{
926 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
927}
928
929static inline struct inode *SOCK_INODE(struct socket *socket)
930{
931 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
932}
933
934/*
935 * Functions for memory accounting
936 */
937extern int __sk_mem_schedule(struct sock *sk, int size, int kind);
938extern void __sk_mem_reclaim(struct sock *sk);
939
940#define SK_MEM_QUANTUM ((int)PAGE_SIZE)
941#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
942#define SK_MEM_SEND 0
943#define SK_MEM_RECV 1
944
945static inline int sk_mem_pages(int amt)
946{
947 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
948}
949
950static inline int sk_has_account(struct sock *sk)
951{
952 /* return true if protocol supports memory accounting */
953 return !!sk->sk_prot->memory_allocated;
954}
955
956static inline int sk_wmem_schedule(struct sock *sk, int size)
957{
958 if (!sk_has_account(sk))
959 return 1;
960 return size <= sk->sk_forward_alloc ||
961 __sk_mem_schedule(sk, size, SK_MEM_SEND);
962}
963
964static inline int sk_rmem_schedule(struct sock *sk, int size)
965{
966 if (!sk_has_account(sk))
967 return 1;
968 return size <= sk->sk_forward_alloc ||
969 __sk_mem_schedule(sk, size, SK_MEM_RECV);
970}
971
972static inline void sk_mem_reclaim(struct sock *sk)
973{
974 if (!sk_has_account(sk))
975 return;
976 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
977 __sk_mem_reclaim(sk);
978}
979
980static inline void sk_mem_reclaim_partial(struct sock *sk)
981{
982 if (!sk_has_account(sk))
983 return;
984 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
985 __sk_mem_reclaim(sk);
986}
987
988static inline void sk_mem_charge(struct sock *sk, int size)
989{
990 if (!sk_has_account(sk))
991 return;
992 sk->sk_forward_alloc -= size;
993}
994
995static inline void sk_mem_uncharge(struct sock *sk, int size)
996{
997 if (!sk_has_account(sk))
998 return;
999 sk->sk_forward_alloc += size;
1000}
1001
1002static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1003{
1004 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1005 sk->sk_wmem_queued -= skb->truesize;
1006 sk_mem_uncharge(sk, skb->truesize);
1007 __kfree_skb(skb);
1008}
1009
1010/* Used by processes to "lock" a socket state, so that
1011 * interrupts and bottom half handlers won't change it
1012 * from under us. It essentially blocks any incoming
1013 * packets, so that we won't get any new data or any
1014 * packets that change the state of the socket.
1015 *
1016 * While locked, BH processing will add new packets to
1017 * the backlog queue. This queue is processed by the
1018 * owner of the socket lock right before it is released.
1019 *
1020 * Since ~2.3.5 it is also exclusive sleep lock serializing
1021 * accesses from user process context.
1022 */
1023#define sock_owned_by_user(sk) ((sk)->sk_lock.owned)
1024
1025/*
1026 * Macro so as to not evaluate some arguments when
1027 * lockdep is not enabled.
1028 *
1029 * Mark both the sk_lock and the sk_lock.slock as a
1030 * per-address-family lock class.
1031 */
1032#define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1033do { \
1034 sk->sk_lock.owned = 0; \
1035 init_waitqueue_head(&sk->sk_lock.wq); \
1036 spin_lock_init(&(sk)->sk_lock.slock); \
1037 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1038 sizeof((sk)->sk_lock)); \
1039 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1040 (skey), (sname)); \
1041 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1042} while (0)
1043
1044extern void lock_sock_nested(struct sock *sk, int subclass);
1045
1046static inline void lock_sock(struct sock *sk)
1047{
1048 lock_sock_nested(sk, 0);
1049}
1050
1051extern void release_sock(struct sock *sk);
1052
1053/* BH context may only use the following locking interface. */
1054#define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1055#define bh_lock_sock_nested(__sk) \
1056 spin_lock_nested(&((__sk)->sk_lock.slock), \
1057 SINGLE_DEPTH_NESTING)
1058#define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1059
1060extern bool lock_sock_fast(struct sock *sk);
1061/**
1062 * unlock_sock_fast - complement of lock_sock_fast
1063 * @sk: socket
1064 * @slow: slow mode
1065 *
1066 * fast unlock socket for user context.
1067 * If slow mode is on, we call regular release_sock()
1068 */
1069static inline void unlock_sock_fast(struct sock *sk, bool slow)
1070{
1071 if (slow)
1072 release_sock(sk);
1073 else
1074 spin_unlock_bh(&sk->sk_lock.slock);
1075}
1076
1077
1078extern struct sock *sk_alloc(struct net *net, int family,
1079 gfp_t priority,
1080 struct proto *prot);
1081extern void sk_free(struct sock *sk);
1082extern void sk_release_kernel(struct sock *sk);
1083extern struct sock *sk_clone(const struct sock *sk,
1084 const gfp_t priority);
1085
1086extern struct sk_buff *sock_wmalloc(struct sock *sk,
1087 unsigned long size, int force,
1088 gfp_t priority);
1089extern struct sk_buff *sock_rmalloc(struct sock *sk,
1090 unsigned long size, int force,
1091 gfp_t priority);
1092extern void sock_wfree(struct sk_buff *skb);
1093extern void sock_rfree(struct sk_buff *skb);
1094
1095extern int sock_setsockopt(struct socket *sock, int level,
1096 int op, char __user *optval,
1097 unsigned int optlen);
1098
1099extern int sock_getsockopt(struct socket *sock, int level,
1100 int op, char __user *optval,
1101 int __user *optlen);
1102extern struct sk_buff *sock_alloc_send_skb(struct sock *sk,
1103 unsigned long size,
1104 int noblock,
1105 int *errcode);
1106extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
1107 unsigned long header_len,
1108 unsigned long data_len,
1109 int noblock,
1110 int *errcode);
1111extern void *sock_kmalloc(struct sock *sk, int size,
1112 gfp_t priority);
1113extern void sock_kfree_s(struct sock *sk, void *mem, int size);
1114extern void sk_send_sigurg(struct sock *sk);
1115
1116#ifdef CONFIG_CGROUPS
1117extern void sock_update_classid(struct sock *sk);
1118#else
1119static inline void sock_update_classid(struct sock *sk)
1120{
1121}
1122#endif
1123
1124/*
1125 * Functions to fill in entries in struct proto_ops when a protocol
1126 * does not implement a particular function.
1127 */
1128extern int sock_no_bind(struct socket *,
1129 struct sockaddr *, int);
1130extern int sock_no_connect(struct socket *,
1131 struct sockaddr *, int, int);
1132extern int sock_no_socketpair(struct socket *,
1133 struct socket *);
1134extern int sock_no_accept(struct socket *,
1135 struct socket *, int);
1136extern int sock_no_getname(struct socket *,
1137 struct sockaddr *, int *, int);
1138extern unsigned int sock_no_poll(struct file *, struct socket *,
1139 struct poll_table_struct *);
1140extern int sock_no_ioctl(struct socket *, unsigned int,
1141 unsigned long);
1142extern int sock_no_listen(struct socket *, int);
1143extern int sock_no_shutdown(struct socket *, int);
1144extern int sock_no_getsockopt(struct socket *, int , int,
1145 char __user *, int __user *);
1146extern int sock_no_setsockopt(struct socket *, int, int,
1147 char __user *, unsigned int);
1148extern int sock_no_sendmsg(struct kiocb *, struct socket *,
1149 struct msghdr *, size_t);
1150extern int sock_no_recvmsg(struct kiocb *, struct socket *,
1151 struct msghdr *, size_t, int);
1152extern int sock_no_mmap(struct file *file,
1153 struct socket *sock,
1154 struct vm_area_struct *vma);
1155extern ssize_t sock_no_sendpage(struct socket *sock,
1156 struct page *page,
1157 int offset, size_t size,
1158 int flags);
1159
1160/*
1161 * Functions to fill in entries in struct proto_ops when a protocol
1162 * uses the inet style.
1163 */
1164extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
1165 char __user *optval, int __user *optlen);
1166extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1167 struct msghdr *msg, size_t size, int flags);
1168extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
1169 char __user *optval, unsigned int optlen);
1170extern int compat_sock_common_getsockopt(struct socket *sock, int level,
1171 int optname, char __user *optval, int __user *optlen);
1172extern int compat_sock_common_setsockopt(struct socket *sock, int level,
1173 int optname, char __user *optval, unsigned int optlen);
1174
1175extern void sk_common_release(struct sock *sk);
1176
1177/*
1178 * Default socket callbacks and setup code
1179 */
1180
1181/* Initialise core socket variables */
1182extern void sock_init_data(struct socket *sock, struct sock *sk);
1183
1184extern void sk_filter_release_rcu(struct rcu_head *rcu);
1185
1186/**
1187 * sk_filter_release - release a socket filter
1188 * @fp: filter to remove
1189 *
1190 * Remove a filter from a socket and release its resources.
1191 */
1192
1193static inline void sk_filter_release(struct sk_filter *fp)
1194{
1195 if (atomic_dec_and_test(&fp->refcnt))
1196 call_rcu(&fp->rcu, sk_filter_release_rcu);
1197}
1198
1199static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp)
1200{
1201 unsigned int size = sk_filter_len(fp);
1202
1203 atomic_sub(size, &sk->sk_omem_alloc);
1204 sk_filter_release(fp);
1205}
1206
1207static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
1208{
1209 atomic_inc(&fp->refcnt);
1210 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
1211}
1212
1213/*
1214 * Socket reference counting postulates.
1215 *
1216 * * Each user of socket SHOULD hold a reference count.
1217 * * Each access point to socket (an hash table bucket, reference from a list,
1218 * running timer, skb in flight MUST hold a reference count.
1219 * * When reference count hits 0, it means it will never increase back.
1220 * * When reference count hits 0, it means that no references from
1221 * outside exist to this socket and current process on current CPU
1222 * is last user and may/should destroy this socket.
1223 * * sk_free is called from any context: process, BH, IRQ. When
1224 * it is called, socket has no references from outside -> sk_free
1225 * may release descendant resources allocated by the socket, but
1226 * to the time when it is called, socket is NOT referenced by any
1227 * hash tables, lists etc.
1228 * * Packets, delivered from outside (from network or from another process)
1229 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1230 * when they sit in queue. Otherwise, packets will leak to hole, when
1231 * socket is looked up by one cpu and unhasing is made by another CPU.
1232 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1233 * (leak to backlog). Packet socket does all the processing inside
1234 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1235 * use separate SMP lock, so that they are prone too.
1236 */
1237
1238/* Ungrab socket and destroy it, if it was the last reference. */
1239static inline void sock_put(struct sock *sk)
1240{
1241 if (atomic_dec_and_test(&sk->sk_refcnt))
1242 sk_free(sk);
1243}
1244
1245extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1246 const int nested);
1247
1248static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1249{
1250 sk->sk_tx_queue_mapping = tx_queue;
1251}
1252
1253static inline void sk_tx_queue_clear(struct sock *sk)
1254{
1255 sk->sk_tx_queue_mapping = -1;
1256}
1257
1258static inline int sk_tx_queue_get(const struct sock *sk)
1259{
1260 return sk ? sk->sk_tx_queue_mapping : -1;
1261}
1262
1263static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1264{
1265 sk_tx_queue_clear(sk);
1266 sk->sk_socket = sock;
1267}
1268
1269static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1270{
1271 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1272 return &rcu_dereference_raw(sk->sk_wq)->wait;
1273}
1274/* Detach socket from process context.
1275 * Announce socket dead, detach it from wait queue and inode.
1276 * Note that parent inode held reference count on this struct sock,
1277 * we do not release it in this function, because protocol
1278 * probably wants some additional cleanups or even continuing
1279 * to work with this socket (TCP).
1280 */
1281static inline void sock_orphan(struct sock *sk)
1282{
1283 write_lock_bh(&sk->sk_callback_lock);
1284 sock_set_flag(sk, SOCK_DEAD);
1285 sk_set_socket(sk, NULL);
1286 sk->sk_wq = NULL;
1287 write_unlock_bh(&sk->sk_callback_lock);
1288}
1289
1290static inline void sock_graft(struct sock *sk, struct socket *parent)
1291{
1292 write_lock_bh(&sk->sk_callback_lock);
1293 sk->sk_wq = parent->wq;
1294 parent->sk = sk;
1295 sk_set_socket(sk, parent);
1296 security_sock_graft(sk, parent);
1297 write_unlock_bh(&sk->sk_callback_lock);
1298}
1299
1300extern int sock_i_uid(struct sock *sk);
1301extern unsigned long sock_i_ino(struct sock *sk);
1302
1303static inline struct dst_entry *
1304__sk_dst_get(struct sock *sk)
1305{
1306 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1307 lockdep_is_held(&sk->sk_lock.slock));
1308}
1309
1310static inline struct dst_entry *
1311sk_dst_get(struct sock *sk)
1312{
1313 struct dst_entry *dst;
1314
1315 rcu_read_lock();
1316 dst = rcu_dereference(sk->sk_dst_cache);
1317 if (dst)
1318 dst_hold(dst);
1319 rcu_read_unlock();
1320 return dst;
1321}
1322
1323extern void sk_reset_txq(struct sock *sk);
1324
1325static inline void dst_negative_advice(struct sock *sk)
1326{
1327 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1328
1329 if (dst && dst->ops->negative_advice) {
1330 ndst = dst->ops->negative_advice(dst);
1331
1332 if (ndst != dst) {
1333 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1334 sk_reset_txq(sk);
1335 }
1336 }
1337}
1338
1339static inline void
1340__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1341{
1342 struct dst_entry *old_dst;
1343
1344 sk_tx_queue_clear(sk);
1345 /*
1346 * This can be called while sk is owned by the caller only,
1347 * with no state that can be checked in a rcu_dereference_check() cond
1348 */
1349 old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1350 rcu_assign_pointer(sk->sk_dst_cache, dst);
1351 dst_release(old_dst);
1352}
1353
1354static inline void
1355sk_dst_set(struct sock *sk, struct dst_entry *dst)
1356{
1357 spin_lock(&sk->sk_dst_lock);
1358 __sk_dst_set(sk, dst);
1359 spin_unlock(&sk->sk_dst_lock);
1360}
1361
1362static inline void
1363__sk_dst_reset(struct sock *sk)
1364{
1365 __sk_dst_set(sk, NULL);
1366}
1367
1368static inline void
1369sk_dst_reset(struct sock *sk)
1370{
1371 spin_lock(&sk->sk_dst_lock);
1372 __sk_dst_reset(sk);
1373 spin_unlock(&sk->sk_dst_lock);
1374}
1375
1376extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1377
1378extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1379
1380static inline int sk_can_gso(const struct sock *sk)
1381{
1382 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1383}
1384
1385extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1386
1387static inline void sk_nocaps_add(struct sock *sk, int flags)
1388{
1389 sk->sk_route_nocaps |= flags;
1390 sk->sk_route_caps &= ~flags;
1391}
1392
1393static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1394 char __user *from, char *to,
1395 int copy, int offset)
1396{
1397 if (skb->ip_summed == CHECKSUM_NONE) {
1398 int err = 0;
1399 __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1400 if (err)
1401 return err;
1402 skb->csum = csum_block_add(skb->csum, csum, offset);
1403 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1404 if (!access_ok(VERIFY_READ, from, copy) ||
1405 __copy_from_user_nocache(to, from, copy))
1406 return -EFAULT;
1407 } else if (copy_from_user(to, from, copy))
1408 return -EFAULT;
1409
1410 return 0;
1411}
1412
1413static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1414 char __user *from, int copy)
1415{
1416 int err, offset = skb->len;
1417
1418 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1419 copy, offset);
1420 if (err)
1421 __skb_trim(skb, offset);
1422
1423 return err;
1424}
1425
1426static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1427 struct sk_buff *skb,
1428 struct page *page,
1429 int off, int copy)
1430{
1431 int err;
1432
1433 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1434 copy, skb->len);
1435 if (err)
1436 return err;
1437
1438 skb->len += copy;
1439 skb->data_len += copy;
1440 skb->truesize += copy;
1441 sk->sk_wmem_queued += copy;
1442 sk_mem_charge(sk, copy);
1443 return 0;
1444}
1445
1446static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1447 struct sk_buff *skb, struct page *page,
1448 int off, int copy)
1449{
1450 if (skb->ip_summed == CHECKSUM_NONE) {
1451 int err = 0;
1452 __wsum csum = csum_and_copy_from_user(from,
1453 page_address(page) + off,
1454 copy, 0, &err);
1455 if (err)
1456 return err;
1457 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1458 } else if (copy_from_user(page_address(page) + off, from, copy))
1459 return -EFAULT;
1460
1461 skb->len += copy;
1462 skb->data_len += copy;
1463 skb->truesize += copy;
1464 sk->sk_wmem_queued += copy;
1465 sk_mem_charge(sk, copy);
1466 return 0;
1467}
1468
1469/**
1470 * sk_wmem_alloc_get - returns write allocations
1471 * @sk: socket
1472 *
1473 * Returns sk_wmem_alloc minus initial offset of one
1474 */
1475static inline int sk_wmem_alloc_get(const struct sock *sk)
1476{
1477 return atomic_read(&sk->sk_wmem_alloc) - 1;
1478}
1479
1480/**
1481 * sk_rmem_alloc_get - returns read allocations
1482 * @sk: socket
1483 *
1484 * Returns sk_rmem_alloc
1485 */
1486static inline int sk_rmem_alloc_get(const struct sock *sk)
1487{
1488 return atomic_read(&sk->sk_rmem_alloc);
1489}
1490
1491/**
1492 * sk_has_allocations - check if allocations are outstanding
1493 * @sk: socket
1494 *
1495 * Returns true if socket has write or read allocations
1496 */
1497static inline int sk_has_allocations(const struct sock *sk)
1498{
1499 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1500}
1501
1502/**
1503 * wq_has_sleeper - check if there are any waiting processes
1504 * @wq: struct socket_wq
1505 *
1506 * Returns true if socket_wq has waiting processes
1507 *
1508 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1509 * barrier call. They were added due to the race found within the tcp code.
1510 *
1511 * Consider following tcp code paths:
1512 *
1513 * CPU1 CPU2
1514 *
1515 * sys_select receive packet
1516 * ... ...
1517 * __add_wait_queue update tp->rcv_nxt
1518 * ... ...
1519 * tp->rcv_nxt check sock_def_readable
1520 * ... {
1521 * schedule rcu_read_lock();
1522 * wq = rcu_dereference(sk->sk_wq);
1523 * if (wq && waitqueue_active(&wq->wait))
1524 * wake_up_interruptible(&wq->wait)
1525 * ...
1526 * }
1527 *
1528 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1529 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
1530 * could then endup calling schedule and sleep forever if there are no more
1531 * data on the socket.
1532 *
1533 */
1534static inline bool wq_has_sleeper(struct socket_wq *wq)
1535{
1536
1537 /*
1538 * We need to be sure we are in sync with the
1539 * add_wait_queue modifications to the wait queue.
1540 *
1541 * This memory barrier is paired in the sock_poll_wait.
1542 */
1543 smp_mb();
1544 return wq && waitqueue_active(&wq->wait);
1545}
1546
1547/**
1548 * sock_poll_wait - place memory barrier behind the poll_wait call.
1549 * @filp: file
1550 * @wait_address: socket wait queue
1551 * @p: poll_table
1552 *
1553 * See the comments in the wq_has_sleeper function.
1554 */
1555static inline void sock_poll_wait(struct file *filp,
1556 wait_queue_head_t *wait_address, poll_table *p)
1557{
1558 if (p && wait_address) {
1559 poll_wait(filp, wait_address, p);
1560 /*
1561 * We need to be sure we are in sync with the
1562 * socket flags modification.
1563 *
1564 * This memory barrier is paired in the wq_has_sleeper.
1565 */
1566 smp_mb();
1567 }
1568}
1569
1570/*
1571 * Queue a received datagram if it will fit. Stream and sequenced
1572 * protocols can't normally use this as they need to fit buffers in
1573 * and play with them.
1574 *
1575 * Inlined as it's very short and called for pretty much every
1576 * packet ever received.
1577 */
1578
1579static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1580{
1581 skb_orphan(skb);
1582 skb->sk = sk;
1583 skb->destructor = sock_wfree;
1584 /*
1585 * We used to take a refcount on sk, but following operation
1586 * is enough to guarantee sk_free() wont free this sock until
1587 * all in-flight packets are completed
1588 */
1589 atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1590}
1591
1592static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1593{
1594 skb_orphan(skb);
1595 skb->sk = sk;
1596 skb->destructor = sock_rfree;
1597 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1598 sk_mem_charge(sk, skb->truesize);
1599}
1600
1601extern void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1602 unsigned long expires);
1603
1604extern void sk_stop_timer(struct sock *sk, struct timer_list* timer);
1605
1606extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1607
1608extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
1609
1610/*
1611 * Recover an error report and clear atomically
1612 */
1613
1614static inline int sock_error(struct sock *sk)
1615{
1616 int err;
1617 if (likely(!sk->sk_err))
1618 return 0;
1619 err = xchg(&sk->sk_err, 0);
1620 return -err;
1621}
1622
1623static inline unsigned long sock_wspace(struct sock *sk)
1624{
1625 int amt = 0;
1626
1627 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1628 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1629 if (amt < 0)
1630 amt = 0;
1631 }
1632 return amt;
1633}
1634
1635static inline void sk_wake_async(struct sock *sk, int how, int band)
1636{
1637 if (sock_flag(sk, SOCK_FASYNC))
1638 sock_wake_async(sk->sk_socket, how, band);
1639}
1640
1641#define SOCK_MIN_SNDBUF 2048
1642/*
1643 * Since sk_rmem_alloc sums skb->truesize, even a small frame might need
1644 * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak
1645 */
1646#define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff))
1647
1648static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1649{
1650 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1651 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
1652 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1653 }
1654}
1655
1656struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
1657
1658static inline struct page *sk_stream_alloc_page(struct sock *sk)
1659{
1660 struct page *page = NULL;
1661
1662 page = alloc_pages(sk->sk_allocation, 0);
1663 if (!page) {
1664 sk->sk_prot->enter_memory_pressure(sk);
1665 sk_stream_moderate_sndbuf(sk);
1666 }
1667 return page;
1668}
1669
1670/*
1671 * Default write policy as shown to user space via poll/select/SIGIO
1672 */
1673static inline int sock_writeable(const struct sock *sk)
1674{
1675 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
1676}
1677
1678static inline gfp_t gfp_any(void)
1679{
1680 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
1681}
1682
1683static inline long sock_rcvtimeo(const struct sock *sk, int noblock)
1684{
1685 return noblock ? 0 : sk->sk_rcvtimeo;
1686}
1687
1688static inline long sock_sndtimeo(const struct sock *sk, int noblock)
1689{
1690 return noblock ? 0 : sk->sk_sndtimeo;
1691}
1692
1693static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
1694{
1695 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
1696}
1697
1698/* Alas, with timeout socket operations are not restartable.
1699 * Compare this to poll().
1700 */
1701static inline int sock_intr_errno(long timeo)
1702{
1703 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1704}
1705
1706extern void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
1707 struct sk_buff *skb);
1708
1709static __inline__ void
1710sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
1711{
1712 ktime_t kt = skb->tstamp;
1713 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
1714
1715 /*
1716 * generate control messages if
1717 * - receive time stamping in software requested (SOCK_RCVTSTAMP
1718 * or SOCK_TIMESTAMPING_RX_SOFTWARE)
1719 * - software time stamp available and wanted
1720 * (SOCK_TIMESTAMPING_SOFTWARE)
1721 * - hardware time stamps available and wanted
1722 * (SOCK_TIMESTAMPING_SYS_HARDWARE or
1723 * SOCK_TIMESTAMPING_RAW_HARDWARE)
1724 */
1725 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
1726 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
1727 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
1728 (hwtstamps->hwtstamp.tv64 &&
1729 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
1730 (hwtstamps->syststamp.tv64 &&
1731 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
1732 __sock_recv_timestamp(msg, sk, skb);
1733 else
1734 sk->sk_stamp = kt;
1735}
1736
1737extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
1738 struct sk_buff *skb);
1739
1740static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
1741 struct sk_buff *skb)
1742{
1743#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
1744 (1UL << SOCK_RCVTSTAMP) | \
1745 (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
1746 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \
1747 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \
1748 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE))
1749
1750 if (sk->sk_flags & FLAGS_TS_OR_DROPS)
1751 __sock_recv_ts_and_drops(msg, sk, skb);
1752 else
1753 sk->sk_stamp = skb->tstamp;
1754}
1755
1756/**
1757 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
1758 * @sk: socket sending this packet
1759 * @tx_flags: filled with instructions for time stamping
1760 *
1761 * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if
1762 * parameters are invalid.
1763 */
1764extern int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
1765
1766/**
1767 * sk_eat_skb - Release a skb if it is no longer needed
1768 * @sk: socket to eat this skb from
1769 * @skb: socket buffer to eat
1770 * @copied_early: flag indicating whether DMA operations copied this data early
1771 *
1772 * This routine must be called with interrupts disabled or with the socket
1773 * locked so that the sk_buff queue operation is ok.
1774*/
1775#ifdef CONFIG_NET_DMA
1776static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1777{
1778 __skb_unlink(skb, &sk->sk_receive_queue);
1779 if (!copied_early)
1780 __kfree_skb(skb);
1781 else
1782 __skb_queue_tail(&sk->sk_async_wait_queue, skb);
1783}
1784#else
1785static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1786{
1787 __skb_unlink(skb, &sk->sk_receive_queue);
1788 __kfree_skb(skb);
1789}
1790#endif
1791
1792static inline
1793struct net *sock_net(const struct sock *sk)
1794{
1795 return read_pnet(&sk->sk_net);
1796}
1797
1798static inline
1799void sock_net_set(struct sock *sk, struct net *net)
1800{
1801 write_pnet(&sk->sk_net, net);
1802}
1803
1804/*
1805 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
1806 * They should not hold a reference to a namespace in order to allow
1807 * to stop it.
1808 * Sockets after sk_change_net should be released using sk_release_kernel
1809 */
1810static inline void sk_change_net(struct sock *sk, struct net *net)
1811{
1812 put_net(sock_net(sk));
1813 sock_net_set(sk, hold_net(net));
1814}
1815
1816static inline struct sock *skb_steal_sock(struct sk_buff *skb)
1817{
1818 if (unlikely(skb->sk)) {
1819 struct sock *sk = skb->sk;
1820
1821 skb->destructor = NULL;
1822 skb->sk = NULL;
1823 return sk;
1824 }
1825 return NULL;
1826}
1827
1828extern void sock_enable_timestamp(struct sock *sk, int flag);
1829extern int sock_get_timestamp(struct sock *, struct timeval __user *);
1830extern int sock_get_timestampns(struct sock *, struct timespec __user *);
1831
1832/*
1833 * Enable debug/info messages
1834 */
1835extern int net_msg_warn;
1836#define NETDEBUG(fmt, args...) \
1837 do { if (net_msg_warn) printk(fmt,##args); } while (0)
1838
1839#define LIMIT_NETDEBUG(fmt, args...) \
1840 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
1841
1842extern __u32 sysctl_wmem_max;
1843extern __u32 sysctl_rmem_max;
1844
1845extern void sk_init(void);
1846
1847extern int sysctl_optmem_max;
1848
1849extern __u32 sysctl_wmem_default;
1850extern __u32 sysctl_rmem_default;
1851
1852#endif /* _SOCK_H */
1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the AF_INET socket handler.
8 *
9 * Version: @(#)sock.h 1.0.4 05/13/93
10 *
11 * Authors: Ross Biro
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * Corey Minyard <wf-rch!minyard@relay.EU.net>
14 * Florian La Roche <flla@stud.uni-sb.de>
15 *
16 * Fixes:
17 * Alan Cox : Volatiles in skbuff pointers. See
18 * skbuff comments. May be overdone,
19 * better to prove they can be removed
20 * than the reverse.
21 * Alan Cox : Added a zapped field for tcp to note
22 * a socket is reset and must stay shut up
23 * Alan Cox : New fields for options
24 * Pauline Middelink : identd support
25 * Alan Cox : Eliminate low level recv/recvfrom
26 * David S. Miller : New socket lookup architecture.
27 * Steve Whitehouse: Default routines for sock_ops
28 * Arnaldo C. Melo : removed net_pinfo, tp_pinfo and made
29 * protinfo be just a void pointer, as the
30 * protocol specific parts were moved to
31 * respective headers and ipv4/v6, etc now
32 * use private slabcaches for its socks
33 * Pedro Hortas : New flags field for socket options
34 */
35#ifndef _SOCK_H
36#define _SOCK_H
37
38#include <linux/hardirq.h>
39#include <linux/kernel.h>
40#include <linux/list.h>
41#include <linux/list_nulls.h>
42#include <linux/timer.h>
43#include <linux/cache.h>
44#include <linux/bitops.h>
45#include <linux/lockdep.h>
46#include <linux/netdevice.h>
47#include <linux/skbuff.h> /* struct sk_buff */
48#include <linux/mm.h>
49#include <linux/security.h>
50#include <linux/slab.h>
51#include <linux/uaccess.h>
52#include <linux/page_counter.h>
53#include <linux/memcontrol.h>
54#include <linux/static_key.h>
55#include <linux/sched.h>
56#include <linux/wait.h>
57#include <linux/cgroup-defs.h>
58#include <linux/rbtree.h>
59#include <linux/filter.h>
60#include <linux/rculist_nulls.h>
61#include <linux/poll.h>
62
63#include <linux/atomic.h>
64#include <linux/refcount.h>
65#include <net/dst.h>
66#include <net/checksum.h>
67#include <net/tcp_states.h>
68#include <linux/net_tstamp.h>
69#include <net/smc.h>
70#include <net/l3mdev.h>
71
72/*
73 * This structure really needs to be cleaned up.
74 * Most of it is for TCP, and not used by any of
75 * the other protocols.
76 */
77
78/* Define this to get the SOCK_DBG debugging facility. */
79#define SOCK_DEBUGGING
80#ifdef SOCK_DEBUGGING
81#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
82 printk(KERN_DEBUG msg); } while (0)
83#else
84/* Validate arguments and do nothing */
85static inline __printf(2, 3)
86void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
87{
88}
89#endif
90
91/* This is the per-socket lock. The spinlock provides a synchronization
92 * between user contexts and software interrupt processing, whereas the
93 * mini-semaphore synchronizes multiple users amongst themselves.
94 */
95typedef struct {
96 spinlock_t slock;
97 int owned;
98 wait_queue_head_t wq;
99 /*
100 * We express the mutex-alike socket_lock semantics
101 * to the lock validator by explicitly managing
102 * the slock as a lock variant (in addition to
103 * the slock itself):
104 */
105#ifdef CONFIG_DEBUG_LOCK_ALLOC
106 struct lockdep_map dep_map;
107#endif
108} socket_lock_t;
109
110struct sock;
111struct proto;
112struct net;
113
114typedef __u32 __bitwise __portpair;
115typedef __u64 __bitwise __addrpair;
116
117/**
118 * struct sock_common - minimal network layer representation of sockets
119 * @skc_daddr: Foreign IPv4 addr
120 * @skc_rcv_saddr: Bound local IPv4 addr
121 * @skc_hash: hash value used with various protocol lookup tables
122 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
123 * @skc_dport: placeholder for inet_dport/tw_dport
124 * @skc_num: placeholder for inet_num/tw_num
125 * @skc_family: network address family
126 * @skc_state: Connection state
127 * @skc_reuse: %SO_REUSEADDR setting
128 * @skc_reuseport: %SO_REUSEPORT setting
129 * @skc_bound_dev_if: bound device index if != 0
130 * @skc_bind_node: bind hash linkage for various protocol lookup tables
131 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
132 * @skc_prot: protocol handlers inside a network family
133 * @skc_net: reference to the network namespace of this socket
134 * @skc_node: main hash linkage for various protocol lookup tables
135 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
136 * @skc_tx_queue_mapping: tx queue number for this connection
137 * @skc_rx_queue_mapping: rx queue number for this connection
138 * @skc_flags: place holder for sk_flags
139 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
140 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
141 * @skc_incoming_cpu: record/match cpu processing incoming packets
142 * @skc_refcnt: reference count
143 *
144 * This is the minimal network layer representation of sockets, the header
145 * for struct sock and struct inet_timewait_sock.
146 */
147struct sock_common {
148 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
149 * address on 64bit arches : cf INET_MATCH()
150 */
151 union {
152 __addrpair skc_addrpair;
153 struct {
154 __be32 skc_daddr;
155 __be32 skc_rcv_saddr;
156 };
157 };
158 union {
159 unsigned int skc_hash;
160 __u16 skc_u16hashes[2];
161 };
162 /* skc_dport && skc_num must be grouped as well */
163 union {
164 __portpair skc_portpair;
165 struct {
166 __be16 skc_dport;
167 __u16 skc_num;
168 };
169 };
170
171 unsigned short skc_family;
172 volatile unsigned char skc_state;
173 unsigned char skc_reuse:4;
174 unsigned char skc_reuseport:1;
175 unsigned char skc_ipv6only:1;
176 unsigned char skc_net_refcnt:1;
177 int skc_bound_dev_if;
178 union {
179 struct hlist_node skc_bind_node;
180 struct hlist_node skc_portaddr_node;
181 };
182 struct proto *skc_prot;
183 possible_net_t skc_net;
184
185#if IS_ENABLED(CONFIG_IPV6)
186 struct in6_addr skc_v6_daddr;
187 struct in6_addr skc_v6_rcv_saddr;
188#endif
189
190 atomic64_t skc_cookie;
191
192 /* following fields are padding to force
193 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
194 * assuming IPV6 is enabled. We use this padding differently
195 * for different kind of 'sockets'
196 */
197 union {
198 unsigned long skc_flags;
199 struct sock *skc_listener; /* request_sock */
200 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
201 };
202 /*
203 * fields between dontcopy_begin/dontcopy_end
204 * are not copied in sock_copy()
205 */
206 /* private: */
207 int skc_dontcopy_begin[0];
208 /* public: */
209 union {
210 struct hlist_node skc_node;
211 struct hlist_nulls_node skc_nulls_node;
212 };
213 unsigned short skc_tx_queue_mapping;
214#ifdef CONFIG_XPS
215 unsigned short skc_rx_queue_mapping;
216#endif
217 union {
218 int skc_incoming_cpu;
219 u32 skc_rcv_wnd;
220 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */
221 };
222
223 refcount_t skc_refcnt;
224 /* private: */
225 int skc_dontcopy_end[0];
226 union {
227 u32 skc_rxhash;
228 u32 skc_window_clamp;
229 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */
230 };
231 /* public: */
232};
233
234struct bpf_sk_storage;
235
236/**
237 * struct sock - network layer representation of sockets
238 * @__sk_common: shared layout with inet_timewait_sock
239 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
240 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
241 * @sk_lock: synchronizer
242 * @sk_kern_sock: True if sock is using kernel lock classes
243 * @sk_rcvbuf: size of receive buffer in bytes
244 * @sk_wq: sock wait queue and async head
245 * @sk_rx_dst: receive input route used by early demux
246 * @sk_dst_cache: destination cache
247 * @sk_dst_pending_confirm: need to confirm neighbour
248 * @sk_policy: flow policy
249 * @sk_receive_queue: incoming packets
250 * @sk_wmem_alloc: transmit queue bytes committed
251 * @sk_tsq_flags: TCP Small Queues flags
252 * @sk_write_queue: Packet sending queue
253 * @sk_omem_alloc: "o" is "option" or "other"
254 * @sk_wmem_queued: persistent queue size
255 * @sk_forward_alloc: space allocated forward
256 * @sk_napi_id: id of the last napi context to receive data for sk
257 * @sk_ll_usec: usecs to busypoll when there is no data
258 * @sk_allocation: allocation mode
259 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
260 * @sk_pacing_status: Pacing status (requested, handled by sch_fq)
261 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
262 * @sk_sndbuf: size of send buffer in bytes
263 * @__sk_flags_offset: empty field used to determine location of bitfield
264 * @sk_padding: unused element for alignment
265 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
266 * @sk_no_check_rx: allow zero checksum in RX packets
267 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
268 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
269 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
270 * @sk_gso_max_size: Maximum GSO segment size to build
271 * @sk_gso_max_segs: Maximum number of GSO segments
272 * @sk_pacing_shift: scaling factor for TCP Small Queues
273 * @sk_lingertime: %SO_LINGER l_linger setting
274 * @sk_backlog: always used with the per-socket spinlock held
275 * @sk_callback_lock: used with the callbacks in the end of this struct
276 * @sk_error_queue: rarely used
277 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
278 * IPV6_ADDRFORM for instance)
279 * @sk_err: last error
280 * @sk_err_soft: errors that don't cause failure but are the cause of a
281 * persistent failure not just 'timed out'
282 * @sk_drops: raw/udp drops counter
283 * @sk_ack_backlog: current listen backlog
284 * @sk_max_ack_backlog: listen backlog set in listen()
285 * @sk_uid: user id of owner
286 * @sk_priority: %SO_PRIORITY setting
287 * @sk_type: socket type (%SOCK_STREAM, etc)
288 * @sk_protocol: which protocol this socket belongs in this network family
289 * @sk_peer_pid: &struct pid for this socket's peer
290 * @sk_peer_cred: %SO_PEERCRED setting
291 * @sk_rcvlowat: %SO_RCVLOWAT setting
292 * @sk_rcvtimeo: %SO_RCVTIMEO setting
293 * @sk_sndtimeo: %SO_SNDTIMEO setting
294 * @sk_txhash: computed flow hash for use on transmit
295 * @sk_filter: socket filtering instructions
296 * @sk_timer: sock cleanup timer
297 * @sk_stamp: time stamp of last packet received
298 * @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
299 * @sk_tsflags: SO_TIMESTAMPING socket options
300 * @sk_tskey: counter to disambiguate concurrent tstamp requests
301 * @sk_zckey: counter to order MSG_ZEROCOPY notifications
302 * @sk_socket: Identd and reporting IO signals
303 * @sk_user_data: RPC layer private data
304 * @sk_frag: cached page frag
305 * @sk_peek_off: current peek_offset value
306 * @sk_send_head: front of stuff to transmit
307 * @sk_security: used by security modules
308 * @sk_mark: generic packet mark
309 * @sk_cgrp_data: cgroup data for this cgroup
310 * @sk_memcg: this socket's memory cgroup association
311 * @sk_write_pending: a write to stream socket waits to start
312 * @sk_state_change: callback to indicate change in the state of the sock
313 * @sk_data_ready: callback to indicate there is data to be processed
314 * @sk_write_space: callback to indicate there is bf sending space available
315 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
316 * @sk_backlog_rcv: callback to process the backlog
317 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
318 * @sk_reuseport_cb: reuseport group container
319 * @sk_rcu: used during RCU grace period
320 * @sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
321 * @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
322 * @sk_txtime_unused: unused txtime flags
323 */
324struct sock {
325 /*
326 * Now struct inet_timewait_sock also uses sock_common, so please just
327 * don't add nothing before this first member (__sk_common) --acme
328 */
329 struct sock_common __sk_common;
330#define sk_node __sk_common.skc_node
331#define sk_nulls_node __sk_common.skc_nulls_node
332#define sk_refcnt __sk_common.skc_refcnt
333#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
334#ifdef CONFIG_XPS
335#define sk_rx_queue_mapping __sk_common.skc_rx_queue_mapping
336#endif
337
338#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
339#define sk_dontcopy_end __sk_common.skc_dontcopy_end
340#define sk_hash __sk_common.skc_hash
341#define sk_portpair __sk_common.skc_portpair
342#define sk_num __sk_common.skc_num
343#define sk_dport __sk_common.skc_dport
344#define sk_addrpair __sk_common.skc_addrpair
345#define sk_daddr __sk_common.skc_daddr
346#define sk_rcv_saddr __sk_common.skc_rcv_saddr
347#define sk_family __sk_common.skc_family
348#define sk_state __sk_common.skc_state
349#define sk_reuse __sk_common.skc_reuse
350#define sk_reuseport __sk_common.skc_reuseport
351#define sk_ipv6only __sk_common.skc_ipv6only
352#define sk_net_refcnt __sk_common.skc_net_refcnt
353#define sk_bound_dev_if __sk_common.skc_bound_dev_if
354#define sk_bind_node __sk_common.skc_bind_node
355#define sk_prot __sk_common.skc_prot
356#define sk_net __sk_common.skc_net
357#define sk_v6_daddr __sk_common.skc_v6_daddr
358#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
359#define sk_cookie __sk_common.skc_cookie
360#define sk_incoming_cpu __sk_common.skc_incoming_cpu
361#define sk_flags __sk_common.skc_flags
362#define sk_rxhash __sk_common.skc_rxhash
363
364 socket_lock_t sk_lock;
365 atomic_t sk_drops;
366 int sk_rcvlowat;
367 struct sk_buff_head sk_error_queue;
368 struct sk_buff *sk_rx_skb_cache;
369 struct sk_buff_head sk_receive_queue;
370 /*
371 * The backlog queue is special, it is always used with
372 * the per-socket spinlock held and requires low latency
373 * access. Therefore we special case it's implementation.
374 * Note : rmem_alloc is in this structure to fill a hole
375 * on 64bit arches, not because its logically part of
376 * backlog.
377 */
378 struct {
379 atomic_t rmem_alloc;
380 int len;
381 struct sk_buff *head;
382 struct sk_buff *tail;
383 } sk_backlog;
384#define sk_rmem_alloc sk_backlog.rmem_alloc
385
386 int sk_forward_alloc;
387#ifdef CONFIG_NET_RX_BUSY_POLL
388 unsigned int sk_ll_usec;
389 /* ===== mostly read cache line ===== */
390 unsigned int sk_napi_id;
391#endif
392 int sk_rcvbuf;
393
394 struct sk_filter __rcu *sk_filter;
395 union {
396 struct socket_wq __rcu *sk_wq;
397 struct socket_wq *sk_wq_raw;
398 };
399#ifdef CONFIG_XFRM
400 struct xfrm_policy __rcu *sk_policy[2];
401#endif
402 struct dst_entry *sk_rx_dst;
403 struct dst_entry __rcu *sk_dst_cache;
404 atomic_t sk_omem_alloc;
405 int sk_sndbuf;
406
407 /* ===== cache line for TX ===== */
408 int sk_wmem_queued;
409 refcount_t sk_wmem_alloc;
410 unsigned long sk_tsq_flags;
411 union {
412 struct sk_buff *sk_send_head;
413 struct rb_root tcp_rtx_queue;
414 };
415 struct sk_buff *sk_tx_skb_cache;
416 struct sk_buff_head sk_write_queue;
417 __s32 sk_peek_off;
418 int sk_write_pending;
419 __u32 sk_dst_pending_confirm;
420 u32 sk_pacing_status; /* see enum sk_pacing */
421 long sk_sndtimeo;
422 struct timer_list sk_timer;
423 __u32 sk_priority;
424 __u32 sk_mark;
425 unsigned long sk_pacing_rate; /* bytes per second */
426 unsigned long sk_max_pacing_rate;
427 struct page_frag sk_frag;
428 netdev_features_t sk_route_caps;
429 netdev_features_t sk_route_nocaps;
430 netdev_features_t sk_route_forced_caps;
431 int sk_gso_type;
432 unsigned int sk_gso_max_size;
433 gfp_t sk_allocation;
434 __u32 sk_txhash;
435
436 /*
437 * Because of non atomicity rules, all
438 * changes are protected by socket lock.
439 */
440 unsigned int __sk_flags_offset[0];
441#ifdef __BIG_ENDIAN_BITFIELD
442#define SK_FL_PROTO_SHIFT 16
443#define SK_FL_PROTO_MASK 0x00ff0000
444
445#define SK_FL_TYPE_SHIFT 0
446#define SK_FL_TYPE_MASK 0x0000ffff
447#else
448#define SK_FL_PROTO_SHIFT 8
449#define SK_FL_PROTO_MASK 0x0000ff00
450
451#define SK_FL_TYPE_SHIFT 16
452#define SK_FL_TYPE_MASK 0xffff0000
453#endif
454
455 unsigned int sk_padding : 1,
456 sk_kern_sock : 1,
457 sk_no_check_tx : 1,
458 sk_no_check_rx : 1,
459 sk_userlocks : 4,
460 sk_protocol : 8,
461 sk_type : 16;
462#define SK_PROTOCOL_MAX U8_MAX
463 u16 sk_gso_max_segs;
464 u8 sk_pacing_shift;
465 unsigned long sk_lingertime;
466 struct proto *sk_prot_creator;
467 rwlock_t sk_callback_lock;
468 int sk_err,
469 sk_err_soft;
470 u32 sk_ack_backlog;
471 u32 sk_max_ack_backlog;
472 kuid_t sk_uid;
473 struct pid *sk_peer_pid;
474 const struct cred *sk_peer_cred;
475 long sk_rcvtimeo;
476 ktime_t sk_stamp;
477#if BITS_PER_LONG==32
478 seqlock_t sk_stamp_seq;
479#endif
480 u16 sk_tsflags;
481 u8 sk_shutdown;
482 u32 sk_tskey;
483 atomic_t sk_zckey;
484
485 u8 sk_clockid;
486 u8 sk_txtime_deadline_mode : 1,
487 sk_txtime_report_errors : 1,
488 sk_txtime_unused : 6;
489
490 struct socket *sk_socket;
491 void *sk_user_data;
492#ifdef CONFIG_SECURITY
493 void *sk_security;
494#endif
495 struct sock_cgroup_data sk_cgrp_data;
496 struct mem_cgroup *sk_memcg;
497 void (*sk_state_change)(struct sock *sk);
498 void (*sk_data_ready)(struct sock *sk);
499 void (*sk_write_space)(struct sock *sk);
500 void (*sk_error_report)(struct sock *sk);
501 int (*sk_backlog_rcv)(struct sock *sk,
502 struct sk_buff *skb);
503#ifdef CONFIG_SOCK_VALIDATE_XMIT
504 struct sk_buff* (*sk_validate_xmit_skb)(struct sock *sk,
505 struct net_device *dev,
506 struct sk_buff *skb);
507#endif
508 void (*sk_destruct)(struct sock *sk);
509 struct sock_reuseport __rcu *sk_reuseport_cb;
510#ifdef CONFIG_BPF_SYSCALL
511 struct bpf_sk_storage __rcu *sk_bpf_storage;
512#endif
513 struct rcu_head sk_rcu;
514};
515
516enum sk_pacing {
517 SK_PACING_NONE = 0,
518 SK_PACING_NEEDED = 1,
519 SK_PACING_FQ = 2,
520};
521
522#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
523
524#define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk)))
525#define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr)
526
527/*
528 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
529 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
530 * on a socket means that the socket will reuse everybody else's port
531 * without looking at the other's sk_reuse value.
532 */
533
534#define SK_NO_REUSE 0
535#define SK_CAN_REUSE 1
536#define SK_FORCE_REUSE 2
537
538int sk_set_peek_off(struct sock *sk, int val);
539
540static inline int sk_peek_offset(struct sock *sk, int flags)
541{
542 if (unlikely(flags & MSG_PEEK)) {
543 return READ_ONCE(sk->sk_peek_off);
544 }
545
546 return 0;
547}
548
549static inline void sk_peek_offset_bwd(struct sock *sk, int val)
550{
551 s32 off = READ_ONCE(sk->sk_peek_off);
552
553 if (unlikely(off >= 0)) {
554 off = max_t(s32, off - val, 0);
555 WRITE_ONCE(sk->sk_peek_off, off);
556 }
557}
558
559static inline void sk_peek_offset_fwd(struct sock *sk, int val)
560{
561 sk_peek_offset_bwd(sk, -val);
562}
563
564/*
565 * Hashed lists helper routines
566 */
567static inline struct sock *sk_entry(const struct hlist_node *node)
568{
569 return hlist_entry(node, struct sock, sk_node);
570}
571
572static inline struct sock *__sk_head(const struct hlist_head *head)
573{
574 return hlist_entry(head->first, struct sock, sk_node);
575}
576
577static inline struct sock *sk_head(const struct hlist_head *head)
578{
579 return hlist_empty(head) ? NULL : __sk_head(head);
580}
581
582static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
583{
584 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
585}
586
587static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
588{
589 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
590}
591
592static inline struct sock *sk_next(const struct sock *sk)
593{
594 return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
595}
596
597static inline struct sock *sk_nulls_next(const struct sock *sk)
598{
599 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
600 hlist_nulls_entry(sk->sk_nulls_node.next,
601 struct sock, sk_nulls_node) :
602 NULL;
603}
604
605static inline bool sk_unhashed(const struct sock *sk)
606{
607 return hlist_unhashed(&sk->sk_node);
608}
609
610static inline bool sk_hashed(const struct sock *sk)
611{
612 return !sk_unhashed(sk);
613}
614
615static inline void sk_node_init(struct hlist_node *node)
616{
617 node->pprev = NULL;
618}
619
620static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
621{
622 node->pprev = NULL;
623}
624
625static inline void __sk_del_node(struct sock *sk)
626{
627 __hlist_del(&sk->sk_node);
628}
629
630/* NB: equivalent to hlist_del_init_rcu */
631static inline bool __sk_del_node_init(struct sock *sk)
632{
633 if (sk_hashed(sk)) {
634 __sk_del_node(sk);
635 sk_node_init(&sk->sk_node);
636 return true;
637 }
638 return false;
639}
640
641/* Grab socket reference count. This operation is valid only
642 when sk is ALREADY grabbed f.e. it is found in hash table
643 or a list and the lookup is made under lock preventing hash table
644 modifications.
645 */
646
647static __always_inline void sock_hold(struct sock *sk)
648{
649 refcount_inc(&sk->sk_refcnt);
650}
651
652/* Ungrab socket in the context, which assumes that socket refcnt
653 cannot hit zero, f.e. it is true in context of any socketcall.
654 */
655static __always_inline void __sock_put(struct sock *sk)
656{
657 refcount_dec(&sk->sk_refcnt);
658}
659
660static inline bool sk_del_node_init(struct sock *sk)
661{
662 bool rc = __sk_del_node_init(sk);
663
664 if (rc) {
665 /* paranoid for a while -acme */
666 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
667 __sock_put(sk);
668 }
669 return rc;
670}
671#define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
672
673static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
674{
675 if (sk_hashed(sk)) {
676 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
677 return true;
678 }
679 return false;
680}
681
682static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
683{
684 bool rc = __sk_nulls_del_node_init_rcu(sk);
685
686 if (rc) {
687 /* paranoid for a while -acme */
688 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
689 __sock_put(sk);
690 }
691 return rc;
692}
693
694static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
695{
696 hlist_add_head(&sk->sk_node, list);
697}
698
699static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
700{
701 sock_hold(sk);
702 __sk_add_node(sk, list);
703}
704
705static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
706{
707 sock_hold(sk);
708 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
709 sk->sk_family == AF_INET6)
710 hlist_add_tail_rcu(&sk->sk_node, list);
711 else
712 hlist_add_head_rcu(&sk->sk_node, list);
713}
714
715static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
716{
717 sock_hold(sk);
718 hlist_add_tail_rcu(&sk->sk_node, list);
719}
720
721static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
722{
723 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
724}
725
726static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
727{
728 sock_hold(sk);
729 __sk_nulls_add_node_rcu(sk, list);
730}
731
732static inline void __sk_del_bind_node(struct sock *sk)
733{
734 __hlist_del(&sk->sk_bind_node);
735}
736
737static inline void sk_add_bind_node(struct sock *sk,
738 struct hlist_head *list)
739{
740 hlist_add_head(&sk->sk_bind_node, list);
741}
742
743#define sk_for_each(__sk, list) \
744 hlist_for_each_entry(__sk, list, sk_node)
745#define sk_for_each_rcu(__sk, list) \
746 hlist_for_each_entry_rcu(__sk, list, sk_node)
747#define sk_nulls_for_each(__sk, node, list) \
748 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
749#define sk_nulls_for_each_rcu(__sk, node, list) \
750 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
751#define sk_for_each_from(__sk) \
752 hlist_for_each_entry_from(__sk, sk_node)
753#define sk_nulls_for_each_from(__sk, node) \
754 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
755 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
756#define sk_for_each_safe(__sk, tmp, list) \
757 hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
758#define sk_for_each_bound(__sk, list) \
759 hlist_for_each_entry(__sk, list, sk_bind_node)
760
761/**
762 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
763 * @tpos: the type * to use as a loop cursor.
764 * @pos: the &struct hlist_node to use as a loop cursor.
765 * @head: the head for your list.
766 * @offset: offset of hlist_node within the struct.
767 *
768 */
769#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \
770 for (pos = rcu_dereference(hlist_first_rcu(head)); \
771 pos != NULL && \
772 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \
773 pos = rcu_dereference(hlist_next_rcu(pos)))
774
775static inline struct user_namespace *sk_user_ns(struct sock *sk)
776{
777 /* Careful only use this in a context where these parameters
778 * can not change and must all be valid, such as recvmsg from
779 * userspace.
780 */
781 return sk->sk_socket->file->f_cred->user_ns;
782}
783
784/* Sock flags */
785enum sock_flags {
786 SOCK_DEAD,
787 SOCK_DONE,
788 SOCK_URGINLINE,
789 SOCK_KEEPOPEN,
790 SOCK_LINGER,
791 SOCK_DESTROY,
792 SOCK_BROADCAST,
793 SOCK_TIMESTAMP,
794 SOCK_ZAPPED,
795 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
796 SOCK_DBG, /* %SO_DEBUG setting */
797 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
798 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
799 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
800 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
801 SOCK_MEMALLOC, /* VM depends on this socket for swapping */
802 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
803 SOCK_FASYNC, /* fasync() active */
804 SOCK_RXQ_OVFL,
805 SOCK_ZEROCOPY, /* buffers from userspace */
806 SOCK_WIFI_STATUS, /* push wifi status to userspace */
807 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
808 * Will use last 4 bytes of packet sent from
809 * user-space instead.
810 */
811 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
812 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
813 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
814 SOCK_TXTIME,
815 SOCK_XDP, /* XDP is attached */
816 SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
817};
818
819#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
820
821static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
822{
823 nsk->sk_flags = osk->sk_flags;
824}
825
826static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
827{
828 __set_bit(flag, &sk->sk_flags);
829}
830
831static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
832{
833 __clear_bit(flag, &sk->sk_flags);
834}
835
836static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
837{
838 return test_bit(flag, &sk->sk_flags);
839}
840
841#ifdef CONFIG_NET
842DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
843static inline int sk_memalloc_socks(void)
844{
845 return static_branch_unlikely(&memalloc_socks_key);
846}
847#else
848
849static inline int sk_memalloc_socks(void)
850{
851 return 0;
852}
853
854#endif
855
856static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
857{
858 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
859}
860
861static inline void sk_acceptq_removed(struct sock *sk)
862{
863 sk->sk_ack_backlog--;
864}
865
866static inline void sk_acceptq_added(struct sock *sk)
867{
868 sk->sk_ack_backlog++;
869}
870
871static inline bool sk_acceptq_is_full(const struct sock *sk)
872{
873 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
874}
875
876/*
877 * Compute minimal free write space needed to queue new packets.
878 */
879static inline int sk_stream_min_wspace(const struct sock *sk)
880{
881 return READ_ONCE(sk->sk_wmem_queued) >> 1;
882}
883
884static inline int sk_stream_wspace(const struct sock *sk)
885{
886 return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
887}
888
889static inline void sk_wmem_queued_add(struct sock *sk, int val)
890{
891 WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
892}
893
894void sk_stream_write_space(struct sock *sk);
895
896/* OOB backlog add */
897static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
898{
899 /* dont let skb dst not refcounted, we are going to leave rcu lock */
900 skb_dst_force(skb);
901
902 if (!sk->sk_backlog.tail)
903 sk->sk_backlog.head = skb;
904 else
905 sk->sk_backlog.tail->next = skb;
906
907 sk->sk_backlog.tail = skb;
908 skb->next = NULL;
909}
910
911/*
912 * Take into account size of receive queue and backlog queue
913 * Do not take into account this skb truesize,
914 * to allow even a single big packet to come.
915 */
916static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
917{
918 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
919
920 return qsize > limit;
921}
922
923/* The per-socket spinlock must be held here. */
924static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
925 unsigned int limit)
926{
927 if (sk_rcvqueues_full(sk, limit))
928 return -ENOBUFS;
929
930 /*
931 * If the skb was allocated from pfmemalloc reserves, only
932 * allow SOCK_MEMALLOC sockets to use it as this socket is
933 * helping free memory
934 */
935 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
936 return -ENOMEM;
937
938 __sk_add_backlog(sk, skb);
939 sk->sk_backlog.len += skb->truesize;
940 return 0;
941}
942
943int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
944
945static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
946{
947 if (sk_memalloc_socks() && skb_pfmemalloc(skb))
948 return __sk_backlog_rcv(sk, skb);
949
950 return sk->sk_backlog_rcv(sk, skb);
951}
952
953static inline void sk_incoming_cpu_update(struct sock *sk)
954{
955 int cpu = raw_smp_processor_id();
956
957 if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
958 WRITE_ONCE(sk->sk_incoming_cpu, cpu);
959}
960
961static inline void sock_rps_record_flow_hash(__u32 hash)
962{
963#ifdef CONFIG_RPS
964 struct rps_sock_flow_table *sock_flow_table;
965
966 rcu_read_lock();
967 sock_flow_table = rcu_dereference(rps_sock_flow_table);
968 rps_record_sock_flow(sock_flow_table, hash);
969 rcu_read_unlock();
970#endif
971}
972
973static inline void sock_rps_record_flow(const struct sock *sk)
974{
975#ifdef CONFIG_RPS
976 if (static_branch_unlikely(&rfs_needed)) {
977 /* Reading sk->sk_rxhash might incur an expensive cache line
978 * miss.
979 *
980 * TCP_ESTABLISHED does cover almost all states where RFS
981 * might be useful, and is cheaper [1] than testing :
982 * IPv4: inet_sk(sk)->inet_daddr
983 * IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
984 * OR an additional socket flag
985 * [1] : sk_state and sk_prot are in the same cache line.
986 */
987 if (sk->sk_state == TCP_ESTABLISHED)
988 sock_rps_record_flow_hash(sk->sk_rxhash);
989 }
990#endif
991}
992
993static inline void sock_rps_save_rxhash(struct sock *sk,
994 const struct sk_buff *skb)
995{
996#ifdef CONFIG_RPS
997 if (unlikely(sk->sk_rxhash != skb->hash))
998 sk->sk_rxhash = skb->hash;
999#endif
1000}
1001
1002static inline void sock_rps_reset_rxhash(struct sock *sk)
1003{
1004#ifdef CONFIG_RPS
1005 sk->sk_rxhash = 0;
1006#endif
1007}
1008
1009#define sk_wait_event(__sk, __timeo, __condition, __wait) \
1010 ({ int __rc; \
1011 release_sock(__sk); \
1012 __rc = __condition; \
1013 if (!__rc) { \
1014 *(__timeo) = wait_woken(__wait, \
1015 TASK_INTERRUPTIBLE, \
1016 *(__timeo)); \
1017 } \
1018 sched_annotate_sleep(); \
1019 lock_sock(__sk); \
1020 __rc = __condition; \
1021 __rc; \
1022 })
1023
1024int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1025int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1026void sk_stream_wait_close(struct sock *sk, long timeo_p);
1027int sk_stream_error(struct sock *sk, int flags, int err);
1028void sk_stream_kill_queues(struct sock *sk);
1029void sk_set_memalloc(struct sock *sk);
1030void sk_clear_memalloc(struct sock *sk);
1031
1032void __sk_flush_backlog(struct sock *sk);
1033
1034static inline bool sk_flush_backlog(struct sock *sk)
1035{
1036 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1037 __sk_flush_backlog(sk);
1038 return true;
1039 }
1040 return false;
1041}
1042
1043int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1044
1045struct request_sock_ops;
1046struct timewait_sock_ops;
1047struct inet_hashinfo;
1048struct raw_hashinfo;
1049struct smc_hashinfo;
1050struct module;
1051
1052/*
1053 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1054 * un-modified. Special care is taken when initializing object to zero.
1055 */
1056static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1057{
1058 if (offsetof(struct sock, sk_node.next) != 0)
1059 memset(sk, 0, offsetof(struct sock, sk_node.next));
1060 memset(&sk->sk_node.pprev, 0,
1061 size - offsetof(struct sock, sk_node.pprev));
1062}
1063
1064/* Networking protocol blocks we attach to sockets.
1065 * socket layer -> transport layer interface
1066 */
1067struct proto {
1068 void (*close)(struct sock *sk,
1069 long timeout);
1070 int (*pre_connect)(struct sock *sk,
1071 struct sockaddr *uaddr,
1072 int addr_len);
1073 int (*connect)(struct sock *sk,
1074 struct sockaddr *uaddr,
1075 int addr_len);
1076 int (*disconnect)(struct sock *sk, int flags);
1077
1078 struct sock * (*accept)(struct sock *sk, int flags, int *err,
1079 bool kern);
1080
1081 int (*ioctl)(struct sock *sk, int cmd,
1082 unsigned long arg);
1083 int (*init)(struct sock *sk);
1084 void (*destroy)(struct sock *sk);
1085 void (*shutdown)(struct sock *sk, int how);
1086 int (*setsockopt)(struct sock *sk, int level,
1087 int optname, char __user *optval,
1088 unsigned int optlen);
1089 int (*getsockopt)(struct sock *sk, int level,
1090 int optname, char __user *optval,
1091 int __user *option);
1092 void (*keepalive)(struct sock *sk, int valbool);
1093#ifdef CONFIG_COMPAT
1094 int (*compat_setsockopt)(struct sock *sk,
1095 int level,
1096 int optname, char __user *optval,
1097 unsigned int optlen);
1098 int (*compat_getsockopt)(struct sock *sk,
1099 int level,
1100 int optname, char __user *optval,
1101 int __user *option);
1102 int (*compat_ioctl)(struct sock *sk,
1103 unsigned int cmd, unsigned long arg);
1104#endif
1105 int (*sendmsg)(struct sock *sk, struct msghdr *msg,
1106 size_t len);
1107 int (*recvmsg)(struct sock *sk, struct msghdr *msg,
1108 size_t len, int noblock, int flags,
1109 int *addr_len);
1110 int (*sendpage)(struct sock *sk, struct page *page,
1111 int offset, size_t size, int flags);
1112 int (*bind)(struct sock *sk,
1113 struct sockaddr *uaddr, int addr_len);
1114
1115 int (*backlog_rcv) (struct sock *sk,
1116 struct sk_buff *skb);
1117
1118 void (*release_cb)(struct sock *sk);
1119
1120 /* Keeping track of sk's, looking them up, and port selection methods. */
1121 int (*hash)(struct sock *sk);
1122 void (*unhash)(struct sock *sk);
1123 void (*rehash)(struct sock *sk);
1124 int (*get_port)(struct sock *sk, unsigned short snum);
1125
1126 /* Keeping track of sockets in use */
1127#ifdef CONFIG_PROC_FS
1128 unsigned int inuse_idx;
1129#endif
1130
1131 bool (*stream_memory_free)(const struct sock *sk, int wake);
1132 bool (*stream_memory_read)(const struct sock *sk);
1133 /* Memory pressure */
1134 void (*enter_memory_pressure)(struct sock *sk);
1135 void (*leave_memory_pressure)(struct sock *sk);
1136 atomic_long_t *memory_allocated; /* Current allocated memory. */
1137 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
1138 /*
1139 * Pressure flag: try to collapse.
1140 * Technical note: it is used by multiple contexts non atomically.
1141 * All the __sk_mem_schedule() is of this nature: accounting
1142 * is strict, actions are advisory and have some latency.
1143 */
1144 unsigned long *memory_pressure;
1145 long *sysctl_mem;
1146
1147 int *sysctl_wmem;
1148 int *sysctl_rmem;
1149 u32 sysctl_wmem_offset;
1150 u32 sysctl_rmem_offset;
1151
1152 int max_header;
1153 bool no_autobind;
1154
1155 struct kmem_cache *slab;
1156 unsigned int obj_size;
1157 slab_flags_t slab_flags;
1158 unsigned int useroffset; /* Usercopy region offset */
1159 unsigned int usersize; /* Usercopy region size */
1160
1161 struct percpu_counter *orphan_count;
1162
1163 struct request_sock_ops *rsk_prot;
1164 struct timewait_sock_ops *twsk_prot;
1165
1166 union {
1167 struct inet_hashinfo *hashinfo;
1168 struct udp_table *udp_table;
1169 struct raw_hashinfo *raw_hash;
1170 struct smc_hashinfo *smc_hash;
1171 } h;
1172
1173 struct module *owner;
1174
1175 char name[32];
1176
1177 struct list_head node;
1178#ifdef SOCK_REFCNT_DEBUG
1179 atomic_t socks;
1180#endif
1181 int (*diag_destroy)(struct sock *sk, int err);
1182} __randomize_layout;
1183
1184int proto_register(struct proto *prot, int alloc_slab);
1185void proto_unregister(struct proto *prot);
1186int sock_load_diag_module(int family, int protocol);
1187
1188#ifdef SOCK_REFCNT_DEBUG
1189static inline void sk_refcnt_debug_inc(struct sock *sk)
1190{
1191 atomic_inc(&sk->sk_prot->socks);
1192}
1193
1194static inline void sk_refcnt_debug_dec(struct sock *sk)
1195{
1196 atomic_dec(&sk->sk_prot->socks);
1197 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1198 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1199}
1200
1201static inline void sk_refcnt_debug_release(const struct sock *sk)
1202{
1203 if (refcount_read(&sk->sk_refcnt) != 1)
1204 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1205 sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1206}
1207#else /* SOCK_REFCNT_DEBUG */
1208#define sk_refcnt_debug_inc(sk) do { } while (0)
1209#define sk_refcnt_debug_dec(sk) do { } while (0)
1210#define sk_refcnt_debug_release(sk) do { } while (0)
1211#endif /* SOCK_REFCNT_DEBUG */
1212
1213static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1214{
1215 if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1216 return false;
1217
1218 return sk->sk_prot->stream_memory_free ?
1219 sk->sk_prot->stream_memory_free(sk, wake) : true;
1220}
1221
1222static inline bool sk_stream_memory_free(const struct sock *sk)
1223{
1224 return __sk_stream_memory_free(sk, 0);
1225}
1226
1227static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1228{
1229 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1230 __sk_stream_memory_free(sk, wake);
1231}
1232
1233static inline bool sk_stream_is_writeable(const struct sock *sk)
1234{
1235 return __sk_stream_is_writeable(sk, 0);
1236}
1237
1238static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1239 struct cgroup *ancestor)
1240{
1241#ifdef CONFIG_SOCK_CGROUP_DATA
1242 return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1243 ancestor);
1244#else
1245 return -ENOTSUPP;
1246#endif
1247}
1248
1249static inline bool sk_has_memory_pressure(const struct sock *sk)
1250{
1251 return sk->sk_prot->memory_pressure != NULL;
1252}
1253
1254static inline bool sk_under_memory_pressure(const struct sock *sk)
1255{
1256 if (!sk->sk_prot->memory_pressure)
1257 return false;
1258
1259 if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1260 mem_cgroup_under_socket_pressure(sk->sk_memcg))
1261 return true;
1262
1263 return !!*sk->sk_prot->memory_pressure;
1264}
1265
1266static inline long
1267sk_memory_allocated(const struct sock *sk)
1268{
1269 return atomic_long_read(sk->sk_prot->memory_allocated);
1270}
1271
1272static inline long
1273sk_memory_allocated_add(struct sock *sk, int amt)
1274{
1275 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1276}
1277
1278static inline void
1279sk_memory_allocated_sub(struct sock *sk, int amt)
1280{
1281 atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1282}
1283
1284static inline void sk_sockets_allocated_dec(struct sock *sk)
1285{
1286 percpu_counter_dec(sk->sk_prot->sockets_allocated);
1287}
1288
1289static inline void sk_sockets_allocated_inc(struct sock *sk)
1290{
1291 percpu_counter_inc(sk->sk_prot->sockets_allocated);
1292}
1293
1294static inline u64
1295sk_sockets_allocated_read_positive(struct sock *sk)
1296{
1297 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1298}
1299
1300static inline int
1301proto_sockets_allocated_sum_positive(struct proto *prot)
1302{
1303 return percpu_counter_sum_positive(prot->sockets_allocated);
1304}
1305
1306static inline long
1307proto_memory_allocated(struct proto *prot)
1308{
1309 return atomic_long_read(prot->memory_allocated);
1310}
1311
1312static inline bool
1313proto_memory_pressure(struct proto *prot)
1314{
1315 if (!prot->memory_pressure)
1316 return false;
1317 return !!*prot->memory_pressure;
1318}
1319
1320
1321#ifdef CONFIG_PROC_FS
1322/* Called with local bh disabled */
1323void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1324int sock_prot_inuse_get(struct net *net, struct proto *proto);
1325int sock_inuse_get(struct net *net);
1326#else
1327static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1328 int inc)
1329{
1330}
1331#endif
1332
1333
1334/* With per-bucket locks this operation is not-atomic, so that
1335 * this version is not worse.
1336 */
1337static inline int __sk_prot_rehash(struct sock *sk)
1338{
1339 sk->sk_prot->unhash(sk);
1340 return sk->sk_prot->hash(sk);
1341}
1342
1343/* About 10 seconds */
1344#define SOCK_DESTROY_TIME (10*HZ)
1345
1346/* Sockets 0-1023 can't be bound to unless you are superuser */
1347#define PROT_SOCK 1024
1348
1349#define SHUTDOWN_MASK 3
1350#define RCV_SHUTDOWN 1
1351#define SEND_SHUTDOWN 2
1352
1353#define SOCK_SNDBUF_LOCK 1
1354#define SOCK_RCVBUF_LOCK 2
1355#define SOCK_BINDADDR_LOCK 4
1356#define SOCK_BINDPORT_LOCK 8
1357
1358struct socket_alloc {
1359 struct socket socket;
1360 struct inode vfs_inode;
1361};
1362
1363static inline struct socket *SOCKET_I(struct inode *inode)
1364{
1365 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1366}
1367
1368static inline struct inode *SOCK_INODE(struct socket *socket)
1369{
1370 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1371}
1372
1373/*
1374 * Functions for memory accounting
1375 */
1376int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1377int __sk_mem_schedule(struct sock *sk, int size, int kind);
1378void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1379void __sk_mem_reclaim(struct sock *sk, int amount);
1380
1381/* We used to have PAGE_SIZE here, but systems with 64KB pages
1382 * do not necessarily have 16x time more memory than 4KB ones.
1383 */
1384#define SK_MEM_QUANTUM 4096
1385#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1386#define SK_MEM_SEND 0
1387#define SK_MEM_RECV 1
1388
1389/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
1390static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1391{
1392 long val = sk->sk_prot->sysctl_mem[index];
1393
1394#if PAGE_SIZE > SK_MEM_QUANTUM
1395 val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1396#elif PAGE_SIZE < SK_MEM_QUANTUM
1397 val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1398#endif
1399 return val;
1400}
1401
1402static inline int sk_mem_pages(int amt)
1403{
1404 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1405}
1406
1407static inline bool sk_has_account(struct sock *sk)
1408{
1409 /* return true if protocol supports memory accounting */
1410 return !!sk->sk_prot->memory_allocated;
1411}
1412
1413static inline bool sk_wmem_schedule(struct sock *sk, int size)
1414{
1415 if (!sk_has_account(sk))
1416 return true;
1417 return size <= sk->sk_forward_alloc ||
1418 __sk_mem_schedule(sk, size, SK_MEM_SEND);
1419}
1420
1421static inline bool
1422sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1423{
1424 if (!sk_has_account(sk))
1425 return true;
1426 return size<= sk->sk_forward_alloc ||
1427 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1428 skb_pfmemalloc(skb);
1429}
1430
1431static inline void sk_mem_reclaim(struct sock *sk)
1432{
1433 if (!sk_has_account(sk))
1434 return;
1435 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1436 __sk_mem_reclaim(sk, sk->sk_forward_alloc);
1437}
1438
1439static inline void sk_mem_reclaim_partial(struct sock *sk)
1440{
1441 if (!sk_has_account(sk))
1442 return;
1443 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1444 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1445}
1446
1447static inline void sk_mem_charge(struct sock *sk, int size)
1448{
1449 if (!sk_has_account(sk))
1450 return;
1451 sk->sk_forward_alloc -= size;
1452}
1453
1454static inline void sk_mem_uncharge(struct sock *sk, int size)
1455{
1456 if (!sk_has_account(sk))
1457 return;
1458 sk->sk_forward_alloc += size;
1459
1460 /* Avoid a possible overflow.
1461 * TCP send queues can make this happen, if sk_mem_reclaim()
1462 * is not called and more than 2 GBytes are released at once.
1463 *
1464 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1465 * no need to hold that much forward allocation anyway.
1466 */
1467 if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1468 __sk_mem_reclaim(sk, 1 << 20);
1469}
1470
1471DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
1472static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1473{
1474 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1475 sk_wmem_queued_add(sk, -skb->truesize);
1476 sk_mem_uncharge(sk, skb->truesize);
1477 if (static_branch_unlikely(&tcp_tx_skb_cache_key) &&
1478 !sk->sk_tx_skb_cache && !skb_cloned(skb)) {
1479 skb_zcopy_clear(skb, true);
1480 sk->sk_tx_skb_cache = skb;
1481 return;
1482 }
1483 __kfree_skb(skb);
1484}
1485
1486static inline void sock_release_ownership(struct sock *sk)
1487{
1488 if (sk->sk_lock.owned) {
1489 sk->sk_lock.owned = 0;
1490
1491 /* The sk_lock has mutex_unlock() semantics: */
1492 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1493 }
1494}
1495
1496/*
1497 * Macro so as to not evaluate some arguments when
1498 * lockdep is not enabled.
1499 *
1500 * Mark both the sk_lock and the sk_lock.slock as a
1501 * per-address-family lock class.
1502 */
1503#define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1504do { \
1505 sk->sk_lock.owned = 0; \
1506 init_waitqueue_head(&sk->sk_lock.wq); \
1507 spin_lock_init(&(sk)->sk_lock.slock); \
1508 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1509 sizeof((sk)->sk_lock)); \
1510 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1511 (skey), (sname)); \
1512 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1513} while (0)
1514
1515#ifdef CONFIG_LOCKDEP
1516static inline bool lockdep_sock_is_held(const struct sock *sk)
1517{
1518 return lockdep_is_held(&sk->sk_lock) ||
1519 lockdep_is_held(&sk->sk_lock.slock);
1520}
1521#endif
1522
1523void lock_sock_nested(struct sock *sk, int subclass);
1524
1525static inline void lock_sock(struct sock *sk)
1526{
1527 lock_sock_nested(sk, 0);
1528}
1529
1530void __release_sock(struct sock *sk);
1531void release_sock(struct sock *sk);
1532
1533/* BH context may only use the following locking interface. */
1534#define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1535#define bh_lock_sock_nested(__sk) \
1536 spin_lock_nested(&((__sk)->sk_lock.slock), \
1537 SINGLE_DEPTH_NESTING)
1538#define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1539
1540bool lock_sock_fast(struct sock *sk);
1541/**
1542 * unlock_sock_fast - complement of lock_sock_fast
1543 * @sk: socket
1544 * @slow: slow mode
1545 *
1546 * fast unlock socket for user context.
1547 * If slow mode is on, we call regular release_sock()
1548 */
1549static inline void unlock_sock_fast(struct sock *sk, bool slow)
1550{
1551 if (slow)
1552 release_sock(sk);
1553 else
1554 spin_unlock_bh(&sk->sk_lock.slock);
1555}
1556
1557/* Used by processes to "lock" a socket state, so that
1558 * interrupts and bottom half handlers won't change it
1559 * from under us. It essentially blocks any incoming
1560 * packets, so that we won't get any new data or any
1561 * packets that change the state of the socket.
1562 *
1563 * While locked, BH processing will add new packets to
1564 * the backlog queue. This queue is processed by the
1565 * owner of the socket lock right before it is released.
1566 *
1567 * Since ~2.3.5 it is also exclusive sleep lock serializing
1568 * accesses from user process context.
1569 */
1570
1571static inline void sock_owned_by_me(const struct sock *sk)
1572{
1573#ifdef CONFIG_LOCKDEP
1574 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1575#endif
1576}
1577
1578static inline bool sock_owned_by_user(const struct sock *sk)
1579{
1580 sock_owned_by_me(sk);
1581 return sk->sk_lock.owned;
1582}
1583
1584static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1585{
1586 return sk->sk_lock.owned;
1587}
1588
1589/* no reclassification while locks are held */
1590static inline bool sock_allow_reclassification(const struct sock *csk)
1591{
1592 struct sock *sk = (struct sock *)csk;
1593
1594 return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1595}
1596
1597struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1598 struct proto *prot, int kern);
1599void sk_free(struct sock *sk);
1600void sk_destruct(struct sock *sk);
1601struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1602void sk_free_unlock_clone(struct sock *sk);
1603
1604struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1605 gfp_t priority);
1606void __sock_wfree(struct sk_buff *skb);
1607void sock_wfree(struct sk_buff *skb);
1608struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1609 gfp_t priority);
1610void skb_orphan_partial(struct sk_buff *skb);
1611void sock_rfree(struct sk_buff *skb);
1612void sock_efree(struct sk_buff *skb);
1613#ifdef CONFIG_INET
1614void sock_edemux(struct sk_buff *skb);
1615#else
1616#define sock_edemux sock_efree
1617#endif
1618
1619int sock_setsockopt(struct socket *sock, int level, int op,
1620 char __user *optval, unsigned int optlen);
1621
1622int sock_getsockopt(struct socket *sock, int level, int op,
1623 char __user *optval, int __user *optlen);
1624int sock_gettstamp(struct socket *sock, void __user *userstamp,
1625 bool timeval, bool time32);
1626struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1627 int noblock, int *errcode);
1628struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1629 unsigned long data_len, int noblock,
1630 int *errcode, int max_page_order);
1631void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1632void sock_kfree_s(struct sock *sk, void *mem, int size);
1633void sock_kzfree_s(struct sock *sk, void *mem, int size);
1634void sk_send_sigurg(struct sock *sk);
1635
1636struct sockcm_cookie {
1637 u64 transmit_time;
1638 u32 mark;
1639 u16 tsflags;
1640};
1641
1642static inline void sockcm_init(struct sockcm_cookie *sockc,
1643 const struct sock *sk)
1644{
1645 *sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1646}
1647
1648int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1649 struct sockcm_cookie *sockc);
1650int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1651 struct sockcm_cookie *sockc);
1652
1653/*
1654 * Functions to fill in entries in struct proto_ops when a protocol
1655 * does not implement a particular function.
1656 */
1657int sock_no_bind(struct socket *, struct sockaddr *, int);
1658int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1659int sock_no_socketpair(struct socket *, struct socket *);
1660int sock_no_accept(struct socket *, struct socket *, int, bool);
1661int sock_no_getname(struct socket *, struct sockaddr *, int);
1662int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1663int sock_no_listen(struct socket *, int);
1664int sock_no_shutdown(struct socket *, int);
1665int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1666int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1667int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1668int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1669int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1670int sock_no_mmap(struct file *file, struct socket *sock,
1671 struct vm_area_struct *vma);
1672ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1673 size_t size, int flags);
1674ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1675 int offset, size_t size, int flags);
1676
1677/*
1678 * Functions to fill in entries in struct proto_ops when a protocol
1679 * uses the inet style.
1680 */
1681int sock_common_getsockopt(struct socket *sock, int level, int optname,
1682 char __user *optval, int __user *optlen);
1683int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1684 int flags);
1685int sock_common_setsockopt(struct socket *sock, int level, int optname,
1686 char __user *optval, unsigned int optlen);
1687int compat_sock_common_getsockopt(struct socket *sock, int level,
1688 int optname, char __user *optval, int __user *optlen);
1689int compat_sock_common_setsockopt(struct socket *sock, int level,
1690 int optname, char __user *optval, unsigned int optlen);
1691
1692void sk_common_release(struct sock *sk);
1693
1694/*
1695 * Default socket callbacks and setup code
1696 */
1697
1698/* Initialise core socket variables */
1699void sock_init_data(struct socket *sock, struct sock *sk);
1700
1701/*
1702 * Socket reference counting postulates.
1703 *
1704 * * Each user of socket SHOULD hold a reference count.
1705 * * Each access point to socket (an hash table bucket, reference from a list,
1706 * running timer, skb in flight MUST hold a reference count.
1707 * * When reference count hits 0, it means it will never increase back.
1708 * * When reference count hits 0, it means that no references from
1709 * outside exist to this socket and current process on current CPU
1710 * is last user and may/should destroy this socket.
1711 * * sk_free is called from any context: process, BH, IRQ. When
1712 * it is called, socket has no references from outside -> sk_free
1713 * may release descendant resources allocated by the socket, but
1714 * to the time when it is called, socket is NOT referenced by any
1715 * hash tables, lists etc.
1716 * * Packets, delivered from outside (from network or from another process)
1717 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1718 * when they sit in queue. Otherwise, packets will leak to hole, when
1719 * socket is looked up by one cpu and unhasing is made by another CPU.
1720 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1721 * (leak to backlog). Packet socket does all the processing inside
1722 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1723 * use separate SMP lock, so that they are prone too.
1724 */
1725
1726/* Ungrab socket and destroy it, if it was the last reference. */
1727static inline void sock_put(struct sock *sk)
1728{
1729 if (refcount_dec_and_test(&sk->sk_refcnt))
1730 sk_free(sk);
1731}
1732/* Generic version of sock_put(), dealing with all sockets
1733 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1734 */
1735void sock_gen_put(struct sock *sk);
1736
1737int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1738 unsigned int trim_cap, bool refcounted);
1739static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1740 const int nested)
1741{
1742 return __sk_receive_skb(sk, skb, nested, 1, true);
1743}
1744
1745static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1746{
1747 /* sk_tx_queue_mapping accept only upto a 16-bit value */
1748 if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1749 return;
1750 sk->sk_tx_queue_mapping = tx_queue;
1751}
1752
1753#define NO_QUEUE_MAPPING USHRT_MAX
1754
1755static inline void sk_tx_queue_clear(struct sock *sk)
1756{
1757 sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1758}
1759
1760static inline int sk_tx_queue_get(const struct sock *sk)
1761{
1762 if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1763 return sk->sk_tx_queue_mapping;
1764
1765 return -1;
1766}
1767
1768static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
1769{
1770#ifdef CONFIG_XPS
1771 if (skb_rx_queue_recorded(skb)) {
1772 u16 rx_queue = skb_get_rx_queue(skb);
1773
1774 if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1775 return;
1776
1777 sk->sk_rx_queue_mapping = rx_queue;
1778 }
1779#endif
1780}
1781
1782static inline void sk_rx_queue_clear(struct sock *sk)
1783{
1784#ifdef CONFIG_XPS
1785 sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1786#endif
1787}
1788
1789#ifdef CONFIG_XPS
1790static inline int sk_rx_queue_get(const struct sock *sk)
1791{
1792 if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1793 return sk->sk_rx_queue_mapping;
1794
1795 return -1;
1796}
1797#endif
1798
1799static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1800{
1801 sk_tx_queue_clear(sk);
1802 sk->sk_socket = sock;
1803}
1804
1805static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1806{
1807 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1808 return &rcu_dereference_raw(sk->sk_wq)->wait;
1809}
1810/* Detach socket from process context.
1811 * Announce socket dead, detach it from wait queue and inode.
1812 * Note that parent inode held reference count on this struct sock,
1813 * we do not release it in this function, because protocol
1814 * probably wants some additional cleanups or even continuing
1815 * to work with this socket (TCP).
1816 */
1817static inline void sock_orphan(struct sock *sk)
1818{
1819 write_lock_bh(&sk->sk_callback_lock);
1820 sock_set_flag(sk, SOCK_DEAD);
1821 sk_set_socket(sk, NULL);
1822 sk->sk_wq = NULL;
1823 write_unlock_bh(&sk->sk_callback_lock);
1824}
1825
1826static inline void sock_graft(struct sock *sk, struct socket *parent)
1827{
1828 WARN_ON(parent->sk);
1829 write_lock_bh(&sk->sk_callback_lock);
1830 rcu_assign_pointer(sk->sk_wq, &parent->wq);
1831 parent->sk = sk;
1832 sk_set_socket(sk, parent);
1833 sk->sk_uid = SOCK_INODE(parent)->i_uid;
1834 security_sock_graft(sk, parent);
1835 write_unlock_bh(&sk->sk_callback_lock);
1836}
1837
1838kuid_t sock_i_uid(struct sock *sk);
1839unsigned long sock_i_ino(struct sock *sk);
1840
1841static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1842{
1843 return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1844}
1845
1846static inline u32 net_tx_rndhash(void)
1847{
1848 u32 v = prandom_u32();
1849
1850 return v ?: 1;
1851}
1852
1853static inline void sk_set_txhash(struct sock *sk)
1854{
1855 sk->sk_txhash = net_tx_rndhash();
1856}
1857
1858static inline void sk_rethink_txhash(struct sock *sk)
1859{
1860 if (sk->sk_txhash)
1861 sk_set_txhash(sk);
1862}
1863
1864static inline struct dst_entry *
1865__sk_dst_get(struct sock *sk)
1866{
1867 return rcu_dereference_check(sk->sk_dst_cache,
1868 lockdep_sock_is_held(sk));
1869}
1870
1871static inline struct dst_entry *
1872sk_dst_get(struct sock *sk)
1873{
1874 struct dst_entry *dst;
1875
1876 rcu_read_lock();
1877 dst = rcu_dereference(sk->sk_dst_cache);
1878 if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1879 dst = NULL;
1880 rcu_read_unlock();
1881 return dst;
1882}
1883
1884static inline void dst_negative_advice(struct sock *sk)
1885{
1886 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1887
1888 sk_rethink_txhash(sk);
1889
1890 if (dst && dst->ops->negative_advice) {
1891 ndst = dst->ops->negative_advice(dst);
1892
1893 if (ndst != dst) {
1894 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1895 sk_tx_queue_clear(sk);
1896 sk->sk_dst_pending_confirm = 0;
1897 }
1898 }
1899}
1900
1901static inline void
1902__sk_dst_set(struct sock *sk, struct dst_entry *dst)
1903{
1904 struct dst_entry *old_dst;
1905
1906 sk_tx_queue_clear(sk);
1907 sk->sk_dst_pending_confirm = 0;
1908 old_dst = rcu_dereference_protected(sk->sk_dst_cache,
1909 lockdep_sock_is_held(sk));
1910 rcu_assign_pointer(sk->sk_dst_cache, dst);
1911 dst_release(old_dst);
1912}
1913
1914static inline void
1915sk_dst_set(struct sock *sk, struct dst_entry *dst)
1916{
1917 struct dst_entry *old_dst;
1918
1919 sk_tx_queue_clear(sk);
1920 sk->sk_dst_pending_confirm = 0;
1921 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1922 dst_release(old_dst);
1923}
1924
1925static inline void
1926__sk_dst_reset(struct sock *sk)
1927{
1928 __sk_dst_set(sk, NULL);
1929}
1930
1931static inline void
1932sk_dst_reset(struct sock *sk)
1933{
1934 sk_dst_set(sk, NULL);
1935}
1936
1937struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1938
1939struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1940
1941static inline void sk_dst_confirm(struct sock *sk)
1942{
1943 if (!sk->sk_dst_pending_confirm)
1944 sk->sk_dst_pending_confirm = 1;
1945}
1946
1947static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
1948{
1949 if (skb_get_dst_pending_confirm(skb)) {
1950 struct sock *sk = skb->sk;
1951 unsigned long now = jiffies;
1952
1953 /* avoid dirtying neighbour */
1954 if (n->confirmed != now)
1955 n->confirmed = now;
1956 if (sk && sk->sk_dst_pending_confirm)
1957 sk->sk_dst_pending_confirm = 0;
1958 }
1959}
1960
1961bool sk_mc_loop(struct sock *sk);
1962
1963static inline bool sk_can_gso(const struct sock *sk)
1964{
1965 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1966}
1967
1968void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1969
1970static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1971{
1972 sk->sk_route_nocaps |= flags;
1973 sk->sk_route_caps &= ~flags;
1974}
1975
1976static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1977 struct iov_iter *from, char *to,
1978 int copy, int offset)
1979{
1980 if (skb->ip_summed == CHECKSUM_NONE) {
1981 __wsum csum = 0;
1982 if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
1983 return -EFAULT;
1984 skb->csum = csum_block_add(skb->csum, csum, offset);
1985 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1986 if (!copy_from_iter_full_nocache(to, copy, from))
1987 return -EFAULT;
1988 } else if (!copy_from_iter_full(to, copy, from))
1989 return -EFAULT;
1990
1991 return 0;
1992}
1993
1994static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1995 struct iov_iter *from, int copy)
1996{
1997 int err, offset = skb->len;
1998
1999 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2000 copy, offset);
2001 if (err)
2002 __skb_trim(skb, offset);
2003
2004 return err;
2005}
2006
2007static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2008 struct sk_buff *skb,
2009 struct page *page,
2010 int off, int copy)
2011{
2012 int err;
2013
2014 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2015 copy, skb->len);
2016 if (err)
2017 return err;
2018
2019 skb->len += copy;
2020 skb->data_len += copy;
2021 skb->truesize += copy;
2022 sk_wmem_queued_add(sk, copy);
2023 sk_mem_charge(sk, copy);
2024 return 0;
2025}
2026
2027/**
2028 * sk_wmem_alloc_get - returns write allocations
2029 * @sk: socket
2030 *
2031 * Returns sk_wmem_alloc minus initial offset of one
2032 */
2033static inline int sk_wmem_alloc_get(const struct sock *sk)
2034{
2035 return refcount_read(&sk->sk_wmem_alloc) - 1;
2036}
2037
2038/**
2039 * sk_rmem_alloc_get - returns read allocations
2040 * @sk: socket
2041 *
2042 * Returns sk_rmem_alloc
2043 */
2044static inline int sk_rmem_alloc_get(const struct sock *sk)
2045{
2046 return atomic_read(&sk->sk_rmem_alloc);
2047}
2048
2049/**
2050 * sk_has_allocations - check if allocations are outstanding
2051 * @sk: socket
2052 *
2053 * Returns true if socket has write or read allocations
2054 */
2055static inline bool sk_has_allocations(const struct sock *sk)
2056{
2057 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2058}
2059
2060/**
2061 * skwq_has_sleeper - check if there are any waiting processes
2062 * @wq: struct socket_wq
2063 *
2064 * Returns true if socket_wq has waiting processes
2065 *
2066 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2067 * barrier call. They were added due to the race found within the tcp code.
2068 *
2069 * Consider following tcp code paths::
2070 *
2071 * CPU1 CPU2
2072 * sys_select receive packet
2073 * ... ...
2074 * __add_wait_queue update tp->rcv_nxt
2075 * ... ...
2076 * tp->rcv_nxt check sock_def_readable
2077 * ... {
2078 * schedule rcu_read_lock();
2079 * wq = rcu_dereference(sk->sk_wq);
2080 * if (wq && waitqueue_active(&wq->wait))
2081 * wake_up_interruptible(&wq->wait)
2082 * ...
2083 * }
2084 *
2085 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2086 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
2087 * could then endup calling schedule and sleep forever if there are no more
2088 * data on the socket.
2089 *
2090 */
2091static inline bool skwq_has_sleeper(struct socket_wq *wq)
2092{
2093 return wq && wq_has_sleeper(&wq->wait);
2094}
2095
2096/**
2097 * sock_poll_wait - place memory barrier behind the poll_wait call.
2098 * @filp: file
2099 * @sock: socket to wait on
2100 * @p: poll_table
2101 *
2102 * See the comments in the wq_has_sleeper function.
2103 */
2104static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2105 poll_table *p)
2106{
2107 if (!poll_does_not_wait(p)) {
2108 poll_wait(filp, &sock->wq.wait, p);
2109 /* We need to be sure we are in sync with the
2110 * socket flags modification.
2111 *
2112 * This memory barrier is paired in the wq_has_sleeper.
2113 */
2114 smp_mb();
2115 }
2116}
2117
2118static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2119{
2120 if (sk->sk_txhash) {
2121 skb->l4_hash = 1;
2122 skb->hash = sk->sk_txhash;
2123 }
2124}
2125
2126void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2127
2128/*
2129 * Queue a received datagram if it will fit. Stream and sequenced
2130 * protocols can't normally use this as they need to fit buffers in
2131 * and play with them.
2132 *
2133 * Inlined as it's very short and called for pretty much every
2134 * packet ever received.
2135 */
2136static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2137{
2138 skb_orphan(skb);
2139 skb->sk = sk;
2140 skb->destructor = sock_rfree;
2141 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2142 sk_mem_charge(sk, skb->truesize);
2143}
2144
2145void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2146 unsigned long expires);
2147
2148void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2149
2150int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2151 struct sk_buff *skb, unsigned int flags,
2152 void (*destructor)(struct sock *sk,
2153 struct sk_buff *skb));
2154int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2155int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2156
2157int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2158struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2159
2160/*
2161 * Recover an error report and clear atomically
2162 */
2163
2164static inline int sock_error(struct sock *sk)
2165{
2166 int err;
2167 if (likely(!sk->sk_err))
2168 return 0;
2169 err = xchg(&sk->sk_err, 0);
2170 return -err;
2171}
2172
2173static inline unsigned long sock_wspace(struct sock *sk)
2174{
2175 int amt = 0;
2176
2177 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2178 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2179 if (amt < 0)
2180 amt = 0;
2181 }
2182 return amt;
2183}
2184
2185/* Note:
2186 * We use sk->sk_wq_raw, from contexts knowing this
2187 * pointer is not NULL and cannot disappear/change.
2188 */
2189static inline void sk_set_bit(int nr, struct sock *sk)
2190{
2191 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2192 !sock_flag(sk, SOCK_FASYNC))
2193 return;
2194
2195 set_bit(nr, &sk->sk_wq_raw->flags);
2196}
2197
2198static inline void sk_clear_bit(int nr, struct sock *sk)
2199{
2200 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2201 !sock_flag(sk, SOCK_FASYNC))
2202 return;
2203
2204 clear_bit(nr, &sk->sk_wq_raw->flags);
2205}
2206
2207static inline void sk_wake_async(const struct sock *sk, int how, int band)
2208{
2209 if (sock_flag(sk, SOCK_FASYNC)) {
2210 rcu_read_lock();
2211 sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2212 rcu_read_unlock();
2213 }
2214}
2215
2216/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2217 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2218 * Note: for send buffers, TCP works better if we can build two skbs at
2219 * minimum.
2220 */
2221#define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2222
2223#define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
2224#define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
2225
2226static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2227{
2228 u32 val;
2229
2230 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2231 return;
2232
2233 val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2234
2235 WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2236}
2237
2238struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2239 bool force_schedule);
2240
2241/**
2242 * sk_page_frag - return an appropriate page_frag
2243 * @sk: socket
2244 *
2245 * Use the per task page_frag instead of the per socket one for
2246 * optimization when we know that we're in the normal context and owns
2247 * everything that's associated with %current.
2248 *
2249 * gfpflags_allow_blocking() isn't enough here as direct reclaim may nest
2250 * inside other socket operations and end up recursing into sk_page_frag()
2251 * while it's already in use.
2252 */
2253static inline struct page_frag *sk_page_frag(struct sock *sk)
2254{
2255 if (gfpflags_normal_context(sk->sk_allocation))
2256 return ¤t->task_frag;
2257
2258 return &sk->sk_frag;
2259}
2260
2261bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2262
2263/*
2264 * Default write policy as shown to user space via poll/select/SIGIO
2265 */
2266static inline bool sock_writeable(const struct sock *sk)
2267{
2268 return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2269}
2270
2271static inline gfp_t gfp_any(void)
2272{
2273 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2274}
2275
2276static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2277{
2278 return noblock ? 0 : sk->sk_rcvtimeo;
2279}
2280
2281static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2282{
2283 return noblock ? 0 : sk->sk_sndtimeo;
2284}
2285
2286static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2287{
2288 int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2289
2290 return v ?: 1;
2291}
2292
2293/* Alas, with timeout socket operations are not restartable.
2294 * Compare this to poll().
2295 */
2296static inline int sock_intr_errno(long timeo)
2297{
2298 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2299}
2300
2301struct sock_skb_cb {
2302 u32 dropcount;
2303};
2304
2305/* Store sock_skb_cb at the end of skb->cb[] so protocol families
2306 * using skb->cb[] would keep using it directly and utilize its
2307 * alignement guarantee.
2308 */
2309#define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \
2310 sizeof(struct sock_skb_cb)))
2311
2312#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2313 SOCK_SKB_CB_OFFSET))
2314
2315#define sock_skb_cb_check_size(size) \
2316 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2317
2318static inline void
2319sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2320{
2321 SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2322 atomic_read(&sk->sk_drops) : 0;
2323}
2324
2325static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2326{
2327 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2328
2329 atomic_add(segs, &sk->sk_drops);
2330}
2331
2332static inline ktime_t sock_read_timestamp(struct sock *sk)
2333{
2334#if BITS_PER_LONG==32
2335 unsigned int seq;
2336 ktime_t kt;
2337
2338 do {
2339 seq = read_seqbegin(&sk->sk_stamp_seq);
2340 kt = sk->sk_stamp;
2341 } while (read_seqretry(&sk->sk_stamp_seq, seq));
2342
2343 return kt;
2344#else
2345 return READ_ONCE(sk->sk_stamp);
2346#endif
2347}
2348
2349static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2350{
2351#if BITS_PER_LONG==32
2352 write_seqlock(&sk->sk_stamp_seq);
2353 sk->sk_stamp = kt;
2354 write_sequnlock(&sk->sk_stamp_seq);
2355#else
2356 WRITE_ONCE(sk->sk_stamp, kt);
2357#endif
2358}
2359
2360void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2361 struct sk_buff *skb);
2362void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2363 struct sk_buff *skb);
2364
2365static inline void
2366sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2367{
2368 ktime_t kt = skb->tstamp;
2369 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2370
2371 /*
2372 * generate control messages if
2373 * - receive time stamping in software requested
2374 * - software time stamp available and wanted
2375 * - hardware time stamps available and wanted
2376 */
2377 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2378 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2379 (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2380 (hwtstamps->hwtstamp &&
2381 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2382 __sock_recv_timestamp(msg, sk, skb);
2383 else
2384 sock_write_timestamp(sk, kt);
2385
2386 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2387 __sock_recv_wifi_status(msg, sk, skb);
2388}
2389
2390void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2391 struct sk_buff *skb);
2392
2393#define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
2394static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2395 struct sk_buff *skb)
2396{
2397#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2398 (1UL << SOCK_RCVTSTAMP))
2399#define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \
2400 SOF_TIMESTAMPING_RAW_HARDWARE)
2401
2402 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2403 __sock_recv_ts_and_drops(msg, sk, skb);
2404 else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2405 sock_write_timestamp(sk, skb->tstamp);
2406 else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2407 sock_write_timestamp(sk, 0);
2408}
2409
2410void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2411
2412/**
2413 * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2414 * @sk: socket sending this packet
2415 * @tsflags: timestamping flags to use
2416 * @tx_flags: completed with instructions for time stamping
2417 * @tskey: filled in with next sk_tskey (not for TCP, which uses seqno)
2418 *
2419 * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2420 */
2421static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2422 __u8 *tx_flags, __u32 *tskey)
2423{
2424 if (unlikely(tsflags)) {
2425 __sock_tx_timestamp(tsflags, tx_flags);
2426 if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2427 tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2428 *tskey = sk->sk_tskey++;
2429 }
2430 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2431 *tx_flags |= SKBTX_WIFI_STATUS;
2432}
2433
2434static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2435 __u8 *tx_flags)
2436{
2437 _sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2438}
2439
2440static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2441{
2442 _sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2443 &skb_shinfo(skb)->tskey);
2444}
2445
2446/**
2447 * sk_eat_skb - Release a skb if it is no longer needed
2448 * @sk: socket to eat this skb from
2449 * @skb: socket buffer to eat
2450 *
2451 * This routine must be called with interrupts disabled or with the socket
2452 * locked so that the sk_buff queue operation is ok.
2453*/
2454DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
2455static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2456{
2457 __skb_unlink(skb, &sk->sk_receive_queue);
2458 if (static_branch_unlikely(&tcp_rx_skb_cache_key) &&
2459 !sk->sk_rx_skb_cache) {
2460 sk->sk_rx_skb_cache = skb;
2461 skb_orphan(skb);
2462 return;
2463 }
2464 __kfree_skb(skb);
2465}
2466
2467static inline
2468struct net *sock_net(const struct sock *sk)
2469{
2470 return read_pnet(&sk->sk_net);
2471}
2472
2473static inline
2474void sock_net_set(struct sock *sk, struct net *net)
2475{
2476 write_pnet(&sk->sk_net, net);
2477}
2478
2479static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2480{
2481 if (skb->sk) {
2482 struct sock *sk = skb->sk;
2483
2484 skb->destructor = NULL;
2485 skb->sk = NULL;
2486 return sk;
2487 }
2488 return NULL;
2489}
2490
2491/* This helper checks if a socket is a full socket,
2492 * ie _not_ a timewait or request socket.
2493 */
2494static inline bool sk_fullsock(const struct sock *sk)
2495{
2496 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2497}
2498
2499/* Checks if this SKB belongs to an HW offloaded socket
2500 * and whether any SW fallbacks are required based on dev.
2501 * Check decrypted mark in case skb_orphan() cleared socket.
2502 */
2503static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2504 struct net_device *dev)
2505{
2506#ifdef CONFIG_SOCK_VALIDATE_XMIT
2507 struct sock *sk = skb->sk;
2508
2509 if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2510 skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2511#ifdef CONFIG_TLS_DEVICE
2512 } else if (unlikely(skb->decrypted)) {
2513 pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2514 kfree_skb(skb);
2515 skb = NULL;
2516#endif
2517 }
2518#endif
2519
2520 return skb;
2521}
2522
2523/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2524 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2525 */
2526static inline bool sk_listener(const struct sock *sk)
2527{
2528 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2529}
2530
2531void sock_enable_timestamp(struct sock *sk, int flag);
2532int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2533 int type);
2534
2535bool sk_ns_capable(const struct sock *sk,
2536 struct user_namespace *user_ns, int cap);
2537bool sk_capable(const struct sock *sk, int cap);
2538bool sk_net_capable(const struct sock *sk, int cap);
2539
2540void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2541
2542/* Take into consideration the size of the struct sk_buff overhead in the
2543 * determination of these values, since that is non-constant across
2544 * platforms. This makes socket queueing behavior and performance
2545 * not depend upon such differences.
2546 */
2547#define _SK_MEM_PACKETS 256
2548#define _SK_MEM_OVERHEAD SKB_TRUESIZE(256)
2549#define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2550#define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2551
2552extern __u32 sysctl_wmem_max;
2553extern __u32 sysctl_rmem_max;
2554
2555extern int sysctl_tstamp_allow_data;
2556extern int sysctl_optmem_max;
2557
2558extern __u32 sysctl_wmem_default;
2559extern __u32 sysctl_rmem_default;
2560
2561DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2562
2563static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2564{
2565 /* Does this proto have per netns sysctl_wmem ? */
2566 if (proto->sysctl_wmem_offset)
2567 return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
2568
2569 return *proto->sysctl_wmem;
2570}
2571
2572static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2573{
2574 /* Does this proto have per netns sysctl_rmem ? */
2575 if (proto->sysctl_rmem_offset)
2576 return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
2577
2578 return *proto->sysctl_rmem;
2579}
2580
2581/* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2582 * Some wifi drivers need to tweak it to get more chunks.
2583 * They can use this helper from their ndo_start_xmit()
2584 */
2585static inline void sk_pacing_shift_update(struct sock *sk, int val)
2586{
2587 if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val)
2588 return;
2589 sk->sk_pacing_shift = val;
2590}
2591
2592/* if a socket is bound to a device, check that the given device
2593 * index is either the same or that the socket is bound to an L3
2594 * master device and the given device index is also enslaved to
2595 * that L3 master
2596 */
2597static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2598{
2599 int mdif;
2600
2601 if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2602 return true;
2603
2604 mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2605 if (mdif && mdif == sk->sk_bound_dev_if)
2606 return true;
2607
2608 return false;
2609}
2610
2611#endif /* _SOCK_H */