net: Split sk_no_check into sk_no_check_{rx,tx}
[deliverable/linux.git] / include / net / sock.h
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Definitions for the AF_INET socket handler.
7 *
8 * Version: @(#)sock.h 1.0.4 05/13/93
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Corey Minyard <wf-rch!minyard@relay.EU.net>
13 * Florian La Roche <flla@stud.uni-sb.de>
14 *
15 * Fixes:
16 * Alan Cox : Volatiles in skbuff pointers. See
17 * skbuff comments. May be overdone,
18 * better to prove they can be removed
19 * than the reverse.
20 * Alan Cox : Added a zapped field for tcp to note
21 * a socket is reset and must stay shut up
22 * Alan Cox : New fields for options
23 * Pauline Middelink : identd support
24 * Alan Cox : Eliminate low level recv/recvfrom
25 * David S. Miller : New socket lookup architecture.
26 * Steve Whitehouse: Default routines for sock_ops
27 * Arnaldo C. Melo : removed net_pinfo, tp_pinfo and made
28 * protinfo be just a void pointer, as the
29 * protocol specific parts were moved to
30 * respective headers and ipv4/v6, etc now
31 * use private slabcaches for its socks
32 * Pedro Hortas : New flags field for socket options
33 *
34 *
35 * This program is free software; you can redistribute it and/or
36 * modify it under the terms of the GNU General Public License
37 * as published by the Free Software Foundation; either version
38 * 2 of the License, or (at your option) any later version.
39 */
40 #ifndef _SOCK_H
41 #define _SOCK_H
42
43 #include <linux/hardirq.h>
44 #include <linux/kernel.h>
45 #include <linux/list.h>
46 #include <linux/list_nulls.h>
47 #include <linux/timer.h>
48 #include <linux/cache.h>
49 #include <linux/bitops.h>
50 #include <linux/lockdep.h>
51 #include <linux/netdevice.h>
52 #include <linux/skbuff.h> /* struct sk_buff */
53 #include <linux/mm.h>
54 #include <linux/security.h>
55 #include <linux/slab.h>
56 #include <linux/uaccess.h>
57 #include <linux/memcontrol.h>
58 #include <linux/res_counter.h>
59 #include <linux/static_key.h>
60 #include <linux/aio.h>
61 #include <linux/sched.h>
62
63 #include <linux/filter.h>
64 #include <linux/rculist_nulls.h>
65 #include <linux/poll.h>
66
67 #include <linux/atomic.h>
68 #include <net/dst.h>
69 #include <net/checksum.h>
70
71 struct cgroup;
72 struct cgroup_subsys;
73 #ifdef CONFIG_NET
74 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
75 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg);
76 #else
77 static inline
78 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
79 {
80 return 0;
81 }
82 static inline
83 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
84 {
85 }
86 #endif
87 /*
88 * This structure really needs to be cleaned up.
89 * Most of it is for TCP, and not used by any of
90 * the other protocols.
91 */
92
93 /* Define this to get the SOCK_DBG debugging facility. */
94 #define SOCK_DEBUGGING
95 #ifdef SOCK_DEBUGGING
96 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
97 printk(KERN_DEBUG msg); } while (0)
98 #else
99 /* Validate arguments and do nothing */
100 static inline __printf(2, 3)
101 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
102 {
103 }
104 #endif
105
106 /* This is the per-socket lock. The spinlock provides a synchronization
107 * between user contexts and software interrupt processing, whereas the
108 * mini-semaphore synchronizes multiple users amongst themselves.
109 */
110 typedef struct {
111 spinlock_t slock;
112 int owned;
113 wait_queue_head_t wq;
114 /*
115 * We express the mutex-alike socket_lock semantics
116 * to the lock validator by explicitly managing
117 * the slock as a lock variant (in addition to
118 * the slock itself):
119 */
120 #ifdef CONFIG_DEBUG_LOCK_ALLOC
121 struct lockdep_map dep_map;
122 #endif
123 } socket_lock_t;
124
125 struct sock;
126 struct proto;
127 struct net;
128
129 typedef __u32 __bitwise __portpair;
130 typedef __u64 __bitwise __addrpair;
131
132 /**
133 * struct sock_common - minimal network layer representation of sockets
134 * @skc_daddr: Foreign IPv4 addr
135 * @skc_rcv_saddr: Bound local IPv4 addr
136 * @skc_hash: hash value used with various protocol lookup tables
137 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
138 * @skc_dport: placeholder for inet_dport/tw_dport
139 * @skc_num: placeholder for inet_num/tw_num
140 * @skc_family: network address family
141 * @skc_state: Connection state
142 * @skc_reuse: %SO_REUSEADDR setting
143 * @skc_reuseport: %SO_REUSEPORT setting
144 * @skc_bound_dev_if: bound device index if != 0
145 * @skc_bind_node: bind hash linkage for various protocol lookup tables
146 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
147 * @skc_prot: protocol handlers inside a network family
148 * @skc_net: reference to the network namespace of this socket
149 * @skc_node: main hash linkage for various protocol lookup tables
150 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
151 * @skc_tx_queue_mapping: tx queue number for this connection
152 * @skc_refcnt: reference count
153 *
154 * This is the minimal network layer representation of sockets, the header
155 * for struct sock and struct inet_timewait_sock.
156 */
157 struct sock_common {
158 /* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
159 * address on 64bit arches : cf INET_MATCH()
160 */
161 union {
162 __addrpair skc_addrpair;
163 struct {
164 __be32 skc_daddr;
165 __be32 skc_rcv_saddr;
166 };
167 };
168 union {
169 unsigned int skc_hash;
170 __u16 skc_u16hashes[2];
171 };
172 /* skc_dport && skc_num must be grouped as well */
173 union {
174 __portpair skc_portpair;
175 struct {
176 __be16 skc_dport;
177 __u16 skc_num;
178 };
179 };
180
181 unsigned short skc_family;
182 volatile unsigned char skc_state;
183 unsigned char skc_reuse:4;
184 unsigned char skc_reuseport:4;
185 int skc_bound_dev_if;
186 union {
187 struct hlist_node skc_bind_node;
188 struct hlist_nulls_node skc_portaddr_node;
189 };
190 struct proto *skc_prot;
191 #ifdef CONFIG_NET_NS
192 struct net *skc_net;
193 #endif
194
195 #if IS_ENABLED(CONFIG_IPV6)
196 struct in6_addr skc_v6_daddr;
197 struct in6_addr skc_v6_rcv_saddr;
198 #endif
199
200 /*
201 * fields between dontcopy_begin/dontcopy_end
202 * are not copied in sock_copy()
203 */
204 /* private: */
205 int skc_dontcopy_begin[0];
206 /* public: */
207 union {
208 struct hlist_node skc_node;
209 struct hlist_nulls_node skc_nulls_node;
210 };
211 int skc_tx_queue_mapping;
212 atomic_t skc_refcnt;
213 /* private: */
214 int skc_dontcopy_end[0];
215 /* public: */
216 };
217
218 struct cg_proto;
219 /**
220 * struct sock - network layer representation of sockets
221 * @__sk_common: shared layout with inet_timewait_sock
222 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
223 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
224 * @sk_lock: synchronizer
225 * @sk_rcvbuf: size of receive buffer in bytes
226 * @sk_wq: sock wait queue and async head
227 * @sk_rx_dst: receive input route used by early demux
228 * @sk_dst_cache: destination cache
229 * @sk_dst_lock: destination cache lock
230 * @sk_policy: flow policy
231 * @sk_receive_queue: incoming packets
232 * @sk_wmem_alloc: transmit queue bytes committed
233 * @sk_write_queue: Packet sending queue
234 * @sk_async_wait_queue: DMA copied packets
235 * @sk_omem_alloc: "o" is "option" or "other"
236 * @sk_wmem_queued: persistent queue size
237 * @sk_forward_alloc: space allocated forward
238 * @sk_napi_id: id of the last napi context to receive data for sk
239 * @sk_ll_usec: usecs to busypoll when there is no data
240 * @sk_allocation: allocation mode
241 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
242 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
243 * @sk_sndbuf: size of send buffer in bytes
244 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
245 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
246 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
247 * @sk_no_check_rx: allow zero checksum in RX packets
248 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
249 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
250 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
251 * @sk_gso_max_size: Maximum GSO segment size to build
252 * @sk_gso_max_segs: Maximum number of GSO segments
253 * @sk_lingertime: %SO_LINGER l_linger setting
254 * @sk_backlog: always used with the per-socket spinlock held
255 * @sk_callback_lock: used with the callbacks in the end of this struct
256 * @sk_error_queue: rarely used
257 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
258 * IPV6_ADDRFORM for instance)
259 * @sk_err: last error
260 * @sk_err_soft: errors that don't cause failure but are the cause of a
261 * persistent failure not just 'timed out'
262 * @sk_drops: raw/udp drops counter
263 * @sk_ack_backlog: current listen backlog
264 * @sk_max_ack_backlog: listen backlog set in listen()
265 * @sk_priority: %SO_PRIORITY setting
266 * @sk_cgrp_prioidx: socket group's priority map index
267 * @sk_type: socket type (%SOCK_STREAM, etc)
268 * @sk_protocol: which protocol this socket belongs in this network family
269 * @sk_peer_pid: &struct pid for this socket's peer
270 * @sk_peer_cred: %SO_PEERCRED setting
271 * @sk_rcvlowat: %SO_RCVLOWAT setting
272 * @sk_rcvtimeo: %SO_RCVTIMEO setting
273 * @sk_sndtimeo: %SO_SNDTIMEO setting
274 * @sk_rxhash: flow hash received from netif layer
275 * @sk_filter: socket filtering instructions
276 * @sk_protinfo: private area, net family specific, when not using slab
277 * @sk_timer: sock cleanup timer
278 * @sk_stamp: time stamp of last packet received
279 * @sk_socket: Identd and reporting IO signals
280 * @sk_user_data: RPC layer private data
281 * @sk_frag: cached page frag
282 * @sk_peek_off: current peek_offset value
283 * @sk_send_head: front of stuff to transmit
284 * @sk_security: used by security modules
285 * @sk_mark: generic packet mark
286 * @sk_classid: this socket's cgroup classid
287 * @sk_cgrp: this socket's cgroup-specific proto data
288 * @sk_write_pending: a write to stream socket waits to start
289 * @sk_state_change: callback to indicate change in the state of the sock
290 * @sk_data_ready: callback to indicate there is data to be processed
291 * @sk_write_space: callback to indicate there is bf sending space available
292 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
293 * @sk_backlog_rcv: callback to process the backlog
294 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
295 */
296 struct sock {
297 /*
298 * Now struct inet_timewait_sock also uses sock_common, so please just
299 * don't add nothing before this first member (__sk_common) --acme
300 */
301 struct sock_common __sk_common;
302 #define sk_node __sk_common.skc_node
303 #define sk_nulls_node __sk_common.skc_nulls_node
304 #define sk_refcnt __sk_common.skc_refcnt
305 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
306
307 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
308 #define sk_dontcopy_end __sk_common.skc_dontcopy_end
309 #define sk_hash __sk_common.skc_hash
310 #define sk_portpair __sk_common.skc_portpair
311 #define sk_num __sk_common.skc_num
312 #define sk_dport __sk_common.skc_dport
313 #define sk_addrpair __sk_common.skc_addrpair
314 #define sk_daddr __sk_common.skc_daddr
315 #define sk_rcv_saddr __sk_common.skc_rcv_saddr
316 #define sk_family __sk_common.skc_family
317 #define sk_state __sk_common.skc_state
318 #define sk_reuse __sk_common.skc_reuse
319 #define sk_reuseport __sk_common.skc_reuseport
320 #define sk_bound_dev_if __sk_common.skc_bound_dev_if
321 #define sk_bind_node __sk_common.skc_bind_node
322 #define sk_prot __sk_common.skc_prot
323 #define sk_net __sk_common.skc_net
324 #define sk_v6_daddr __sk_common.skc_v6_daddr
325 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
326
327 socket_lock_t sk_lock;
328 struct sk_buff_head sk_receive_queue;
329 /*
330 * The backlog queue is special, it is always used with
331 * the per-socket spinlock held and requires low latency
332 * access. Therefore we special case it's implementation.
333 * Note : rmem_alloc is in this structure to fill a hole
334 * on 64bit arches, not because its logically part of
335 * backlog.
336 */
337 struct {
338 atomic_t rmem_alloc;
339 int len;
340 struct sk_buff *head;
341 struct sk_buff *tail;
342 } sk_backlog;
343 #define sk_rmem_alloc sk_backlog.rmem_alloc
344 int sk_forward_alloc;
345 #ifdef CONFIG_RPS
346 __u32 sk_rxhash;
347 #endif
348 #ifdef CONFIG_NET_RX_BUSY_POLL
349 unsigned int sk_napi_id;
350 unsigned int sk_ll_usec;
351 #endif
352 atomic_t sk_drops;
353 int sk_rcvbuf;
354
355 struct sk_filter __rcu *sk_filter;
356 struct socket_wq __rcu *sk_wq;
357
358 #ifdef CONFIG_NET_DMA
359 struct sk_buff_head sk_async_wait_queue;
360 #endif
361
362 #ifdef CONFIG_XFRM
363 struct xfrm_policy *sk_policy[2];
364 #endif
365 unsigned long sk_flags;
366 struct dst_entry *sk_rx_dst;
367 struct dst_entry __rcu *sk_dst_cache;
368 spinlock_t sk_dst_lock;
369 atomic_t sk_wmem_alloc;
370 atomic_t sk_omem_alloc;
371 int sk_sndbuf;
372 struct sk_buff_head sk_write_queue;
373 kmemcheck_bitfield_begin(flags);
374 unsigned int sk_shutdown : 2,
375 sk_no_check_tx : 1,
376 sk_no_check_rx : 1,
377 sk_userlocks : 4,
378 sk_protocol : 8,
379 sk_type : 16;
380 kmemcheck_bitfield_end(flags);
381 int sk_wmem_queued;
382 gfp_t sk_allocation;
383 u32 sk_pacing_rate; /* bytes per second */
384 u32 sk_max_pacing_rate;
385 netdev_features_t sk_route_caps;
386 netdev_features_t sk_route_nocaps;
387 int sk_gso_type;
388 unsigned int sk_gso_max_size;
389 u16 sk_gso_max_segs;
390 int sk_rcvlowat;
391 unsigned long sk_lingertime;
392 struct sk_buff_head sk_error_queue;
393 struct proto *sk_prot_creator;
394 rwlock_t sk_callback_lock;
395 int sk_err,
396 sk_err_soft;
397 unsigned short sk_ack_backlog;
398 unsigned short sk_max_ack_backlog;
399 __u32 sk_priority;
400 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
401 __u32 sk_cgrp_prioidx;
402 #endif
403 struct pid *sk_peer_pid;
404 const struct cred *sk_peer_cred;
405 long sk_rcvtimeo;
406 long sk_sndtimeo;
407 void *sk_protinfo;
408 struct timer_list sk_timer;
409 ktime_t sk_stamp;
410 struct socket *sk_socket;
411 void *sk_user_data;
412 struct page_frag sk_frag;
413 struct sk_buff *sk_send_head;
414 __s32 sk_peek_off;
415 int sk_write_pending;
416 #ifdef CONFIG_SECURITY
417 void *sk_security;
418 #endif
419 __u32 sk_mark;
420 u32 sk_classid;
421 struct cg_proto *sk_cgrp;
422 void (*sk_state_change)(struct sock *sk);
423 void (*sk_data_ready)(struct sock *sk);
424 void (*sk_write_space)(struct sock *sk);
425 void (*sk_error_report)(struct sock *sk);
426 int (*sk_backlog_rcv)(struct sock *sk,
427 struct sk_buff *skb);
428 void (*sk_destruct)(struct sock *sk);
429 };
430
431 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
432
433 #define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk)))
434 #define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr)
435
436 /*
437 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
438 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
439 * on a socket means that the socket will reuse everybody else's port
440 * without looking at the other's sk_reuse value.
441 */
442
443 #define SK_NO_REUSE 0
444 #define SK_CAN_REUSE 1
445 #define SK_FORCE_REUSE 2
446
447 static inline int sk_peek_offset(struct sock *sk, int flags)
448 {
449 if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
450 return sk->sk_peek_off;
451 else
452 return 0;
453 }
454
455 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
456 {
457 if (sk->sk_peek_off >= 0) {
458 if (sk->sk_peek_off >= val)
459 sk->sk_peek_off -= val;
460 else
461 sk->sk_peek_off = 0;
462 }
463 }
464
465 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
466 {
467 if (sk->sk_peek_off >= 0)
468 sk->sk_peek_off += val;
469 }
470
471 /*
472 * Hashed lists helper routines
473 */
474 static inline struct sock *sk_entry(const struct hlist_node *node)
475 {
476 return hlist_entry(node, struct sock, sk_node);
477 }
478
479 static inline struct sock *__sk_head(const struct hlist_head *head)
480 {
481 return hlist_entry(head->first, struct sock, sk_node);
482 }
483
484 static inline struct sock *sk_head(const struct hlist_head *head)
485 {
486 return hlist_empty(head) ? NULL : __sk_head(head);
487 }
488
489 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
490 {
491 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
492 }
493
494 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
495 {
496 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
497 }
498
499 static inline struct sock *sk_next(const struct sock *sk)
500 {
501 return sk->sk_node.next ?
502 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
503 }
504
505 static inline struct sock *sk_nulls_next(const struct sock *sk)
506 {
507 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
508 hlist_nulls_entry(sk->sk_nulls_node.next,
509 struct sock, sk_nulls_node) :
510 NULL;
511 }
512
513 static inline bool sk_unhashed(const struct sock *sk)
514 {
515 return hlist_unhashed(&sk->sk_node);
516 }
517
518 static inline bool sk_hashed(const struct sock *sk)
519 {
520 return !sk_unhashed(sk);
521 }
522
523 static inline void sk_node_init(struct hlist_node *node)
524 {
525 node->pprev = NULL;
526 }
527
528 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
529 {
530 node->pprev = NULL;
531 }
532
533 static inline void __sk_del_node(struct sock *sk)
534 {
535 __hlist_del(&sk->sk_node);
536 }
537
538 /* NB: equivalent to hlist_del_init_rcu */
539 static inline bool __sk_del_node_init(struct sock *sk)
540 {
541 if (sk_hashed(sk)) {
542 __sk_del_node(sk);
543 sk_node_init(&sk->sk_node);
544 return true;
545 }
546 return false;
547 }
548
549 /* Grab socket reference count. This operation is valid only
550 when sk is ALREADY grabbed f.e. it is found in hash table
551 or a list and the lookup is made under lock preventing hash table
552 modifications.
553 */
554
555 static inline void sock_hold(struct sock *sk)
556 {
557 atomic_inc(&sk->sk_refcnt);
558 }
559
560 /* Ungrab socket in the context, which assumes that socket refcnt
561 cannot hit zero, f.e. it is true in context of any socketcall.
562 */
563 static inline void __sock_put(struct sock *sk)
564 {
565 atomic_dec(&sk->sk_refcnt);
566 }
567
568 static inline bool sk_del_node_init(struct sock *sk)
569 {
570 bool rc = __sk_del_node_init(sk);
571
572 if (rc) {
573 /* paranoid for a while -acme */
574 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
575 __sock_put(sk);
576 }
577 return rc;
578 }
579 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
580
581 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
582 {
583 if (sk_hashed(sk)) {
584 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
585 return true;
586 }
587 return false;
588 }
589
590 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
591 {
592 bool rc = __sk_nulls_del_node_init_rcu(sk);
593
594 if (rc) {
595 /* paranoid for a while -acme */
596 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
597 __sock_put(sk);
598 }
599 return rc;
600 }
601
602 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
603 {
604 hlist_add_head(&sk->sk_node, list);
605 }
606
607 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
608 {
609 sock_hold(sk);
610 __sk_add_node(sk, list);
611 }
612
613 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
614 {
615 sock_hold(sk);
616 hlist_add_head_rcu(&sk->sk_node, list);
617 }
618
619 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
620 {
621 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
622 }
623
624 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
625 {
626 sock_hold(sk);
627 __sk_nulls_add_node_rcu(sk, list);
628 }
629
630 static inline void __sk_del_bind_node(struct sock *sk)
631 {
632 __hlist_del(&sk->sk_bind_node);
633 }
634
635 static inline void sk_add_bind_node(struct sock *sk,
636 struct hlist_head *list)
637 {
638 hlist_add_head(&sk->sk_bind_node, list);
639 }
640
641 #define sk_for_each(__sk, list) \
642 hlist_for_each_entry(__sk, list, sk_node)
643 #define sk_for_each_rcu(__sk, list) \
644 hlist_for_each_entry_rcu(__sk, list, sk_node)
645 #define sk_nulls_for_each(__sk, node, list) \
646 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
647 #define sk_nulls_for_each_rcu(__sk, node, list) \
648 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
649 #define sk_for_each_from(__sk) \
650 hlist_for_each_entry_from(__sk, sk_node)
651 #define sk_nulls_for_each_from(__sk, node) \
652 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
653 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
654 #define sk_for_each_safe(__sk, tmp, list) \
655 hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
656 #define sk_for_each_bound(__sk, list) \
657 hlist_for_each_entry(__sk, list, sk_bind_node)
658
659 static inline struct user_namespace *sk_user_ns(struct sock *sk)
660 {
661 /* Careful only use this in a context where these parameters
662 * can not change and must all be valid, such as recvmsg from
663 * userspace.
664 */
665 return sk->sk_socket->file->f_cred->user_ns;
666 }
667
668 /* Sock flags */
669 enum sock_flags {
670 SOCK_DEAD,
671 SOCK_DONE,
672 SOCK_URGINLINE,
673 SOCK_KEEPOPEN,
674 SOCK_LINGER,
675 SOCK_DESTROY,
676 SOCK_BROADCAST,
677 SOCK_TIMESTAMP,
678 SOCK_ZAPPED,
679 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
680 SOCK_DBG, /* %SO_DEBUG setting */
681 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
682 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
683 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
684 SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
685 SOCK_MEMALLOC, /* VM depends on this socket for swapping */
686 SOCK_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */
687 SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */
688 SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */
689 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
690 SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */
691 SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
692 SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
693 SOCK_FASYNC, /* fasync() active */
694 SOCK_RXQ_OVFL,
695 SOCK_ZEROCOPY, /* buffers from userspace */
696 SOCK_WIFI_STATUS, /* push wifi status to userspace */
697 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
698 * Will use last 4 bytes of packet sent from
699 * user-space instead.
700 */
701 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
702 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
703 };
704
705 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
706 {
707 nsk->sk_flags = osk->sk_flags;
708 }
709
710 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
711 {
712 __set_bit(flag, &sk->sk_flags);
713 }
714
715 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
716 {
717 __clear_bit(flag, &sk->sk_flags);
718 }
719
720 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
721 {
722 return test_bit(flag, &sk->sk_flags);
723 }
724
725 #ifdef CONFIG_NET
726 extern struct static_key memalloc_socks;
727 static inline int sk_memalloc_socks(void)
728 {
729 return static_key_false(&memalloc_socks);
730 }
731 #else
732
733 static inline int sk_memalloc_socks(void)
734 {
735 return 0;
736 }
737
738 #endif
739
740 static inline gfp_t sk_gfp_atomic(struct sock *sk, gfp_t gfp_mask)
741 {
742 return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC);
743 }
744
745 static inline void sk_acceptq_removed(struct sock *sk)
746 {
747 sk->sk_ack_backlog--;
748 }
749
750 static inline void sk_acceptq_added(struct sock *sk)
751 {
752 sk->sk_ack_backlog++;
753 }
754
755 static inline bool sk_acceptq_is_full(const struct sock *sk)
756 {
757 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
758 }
759
760 /*
761 * Compute minimal free write space needed to queue new packets.
762 */
763 static inline int sk_stream_min_wspace(const struct sock *sk)
764 {
765 return sk->sk_wmem_queued >> 1;
766 }
767
768 static inline int sk_stream_wspace(const struct sock *sk)
769 {
770 return sk->sk_sndbuf - sk->sk_wmem_queued;
771 }
772
773 void sk_stream_write_space(struct sock *sk);
774
775 /* OOB backlog add */
776 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
777 {
778 /* dont let skb dst not refcounted, we are going to leave rcu lock */
779 skb_dst_force(skb);
780
781 if (!sk->sk_backlog.tail)
782 sk->sk_backlog.head = skb;
783 else
784 sk->sk_backlog.tail->next = skb;
785
786 sk->sk_backlog.tail = skb;
787 skb->next = NULL;
788 }
789
790 /*
791 * Take into account size of receive queue and backlog queue
792 * Do not take into account this skb truesize,
793 * to allow even a single big packet to come.
794 */
795 static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb,
796 unsigned int limit)
797 {
798 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
799
800 return qsize > limit;
801 }
802
803 /* The per-socket spinlock must be held here. */
804 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
805 unsigned int limit)
806 {
807 if (sk_rcvqueues_full(sk, skb, limit))
808 return -ENOBUFS;
809
810 __sk_add_backlog(sk, skb);
811 sk->sk_backlog.len += skb->truesize;
812 return 0;
813 }
814
815 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
816
817 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
818 {
819 if (sk_memalloc_socks() && skb_pfmemalloc(skb))
820 return __sk_backlog_rcv(sk, skb);
821
822 return sk->sk_backlog_rcv(sk, skb);
823 }
824
825 static inline void sock_rps_record_flow_hash(__u32 hash)
826 {
827 #ifdef CONFIG_RPS
828 struct rps_sock_flow_table *sock_flow_table;
829
830 rcu_read_lock();
831 sock_flow_table = rcu_dereference(rps_sock_flow_table);
832 rps_record_sock_flow(sock_flow_table, hash);
833 rcu_read_unlock();
834 #endif
835 }
836
837 static inline void sock_rps_reset_flow_hash(__u32 hash)
838 {
839 #ifdef CONFIG_RPS
840 struct rps_sock_flow_table *sock_flow_table;
841
842 rcu_read_lock();
843 sock_flow_table = rcu_dereference(rps_sock_flow_table);
844 rps_reset_sock_flow(sock_flow_table, hash);
845 rcu_read_unlock();
846 #endif
847 }
848
849 static inline void sock_rps_record_flow(const struct sock *sk)
850 {
851 #ifdef CONFIG_RPS
852 sock_rps_record_flow_hash(sk->sk_rxhash);
853 #endif
854 }
855
856 static inline void sock_rps_reset_flow(const struct sock *sk)
857 {
858 #ifdef CONFIG_RPS
859 sock_rps_reset_flow_hash(sk->sk_rxhash);
860 #endif
861 }
862
863 static inline void sock_rps_save_rxhash(struct sock *sk,
864 const struct sk_buff *skb)
865 {
866 #ifdef CONFIG_RPS
867 if (unlikely(sk->sk_rxhash != skb->hash)) {
868 sock_rps_reset_flow(sk);
869 sk->sk_rxhash = skb->hash;
870 }
871 #endif
872 }
873
874 static inline void sock_rps_reset_rxhash(struct sock *sk)
875 {
876 #ifdef CONFIG_RPS
877 sock_rps_reset_flow(sk);
878 sk->sk_rxhash = 0;
879 #endif
880 }
881
882 #define sk_wait_event(__sk, __timeo, __condition) \
883 ({ int __rc; \
884 release_sock(__sk); \
885 __rc = __condition; \
886 if (!__rc) { \
887 *(__timeo) = schedule_timeout(*(__timeo)); \
888 } \
889 lock_sock(__sk); \
890 __rc = __condition; \
891 __rc; \
892 })
893
894 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
895 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
896 void sk_stream_wait_close(struct sock *sk, long timeo_p);
897 int sk_stream_error(struct sock *sk, int flags, int err);
898 void sk_stream_kill_queues(struct sock *sk);
899 void sk_set_memalloc(struct sock *sk);
900 void sk_clear_memalloc(struct sock *sk);
901
902 int sk_wait_data(struct sock *sk, long *timeo);
903
904 struct request_sock_ops;
905 struct timewait_sock_ops;
906 struct inet_hashinfo;
907 struct raw_hashinfo;
908 struct module;
909
910 /*
911 * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
912 * un-modified. Special care is taken when initializing object to zero.
913 */
914 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
915 {
916 if (offsetof(struct sock, sk_node.next) != 0)
917 memset(sk, 0, offsetof(struct sock, sk_node.next));
918 memset(&sk->sk_node.pprev, 0,
919 size - offsetof(struct sock, sk_node.pprev));
920 }
921
922 /* Networking protocol blocks we attach to sockets.
923 * socket layer -> transport layer interface
924 * transport -> network interface is defined by struct inet_proto
925 */
926 struct proto {
927 void (*close)(struct sock *sk,
928 long timeout);
929 int (*connect)(struct sock *sk,
930 struct sockaddr *uaddr,
931 int addr_len);
932 int (*disconnect)(struct sock *sk, int flags);
933
934 struct sock * (*accept)(struct sock *sk, int flags, int *err);
935
936 int (*ioctl)(struct sock *sk, int cmd,
937 unsigned long arg);
938 int (*init)(struct sock *sk);
939 void (*destroy)(struct sock *sk);
940 void (*shutdown)(struct sock *sk, int how);
941 int (*setsockopt)(struct sock *sk, int level,
942 int optname, char __user *optval,
943 unsigned int optlen);
944 int (*getsockopt)(struct sock *sk, int level,
945 int optname, char __user *optval,
946 int __user *option);
947 #ifdef CONFIG_COMPAT
948 int (*compat_setsockopt)(struct sock *sk,
949 int level,
950 int optname, char __user *optval,
951 unsigned int optlen);
952 int (*compat_getsockopt)(struct sock *sk,
953 int level,
954 int optname, char __user *optval,
955 int __user *option);
956 int (*compat_ioctl)(struct sock *sk,
957 unsigned int cmd, unsigned long arg);
958 #endif
959 int (*sendmsg)(struct kiocb *iocb, struct sock *sk,
960 struct msghdr *msg, size_t len);
961 int (*recvmsg)(struct kiocb *iocb, struct sock *sk,
962 struct msghdr *msg,
963 size_t len, int noblock, int flags,
964 int *addr_len);
965 int (*sendpage)(struct sock *sk, struct page *page,
966 int offset, size_t size, int flags);
967 int (*bind)(struct sock *sk,
968 struct sockaddr *uaddr, int addr_len);
969
970 int (*backlog_rcv) (struct sock *sk,
971 struct sk_buff *skb);
972
973 void (*release_cb)(struct sock *sk);
974 void (*mtu_reduced)(struct sock *sk);
975
976 /* Keeping track of sk's, looking them up, and port selection methods. */
977 void (*hash)(struct sock *sk);
978 void (*unhash)(struct sock *sk);
979 void (*rehash)(struct sock *sk);
980 int (*get_port)(struct sock *sk, unsigned short snum);
981 void (*clear_sk)(struct sock *sk, int size);
982
983 /* Keeping track of sockets in use */
984 #ifdef CONFIG_PROC_FS
985 unsigned int inuse_idx;
986 #endif
987
988 bool (*stream_memory_free)(const struct sock *sk);
989 /* Memory pressure */
990 void (*enter_memory_pressure)(struct sock *sk);
991 atomic_long_t *memory_allocated; /* Current allocated memory. */
992 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
993 /*
994 * Pressure flag: try to collapse.
995 * Technical note: it is used by multiple contexts non atomically.
996 * All the __sk_mem_schedule() is of this nature: accounting
997 * is strict, actions are advisory and have some latency.
998 */
999 int *memory_pressure;
1000 long *sysctl_mem;
1001 int *sysctl_wmem;
1002 int *sysctl_rmem;
1003 int max_header;
1004 bool no_autobind;
1005
1006 struct kmem_cache *slab;
1007 unsigned int obj_size;
1008 int slab_flags;
1009
1010 struct percpu_counter *orphan_count;
1011
1012 struct request_sock_ops *rsk_prot;
1013 struct timewait_sock_ops *twsk_prot;
1014
1015 union {
1016 struct inet_hashinfo *hashinfo;
1017 struct udp_table *udp_table;
1018 struct raw_hashinfo *raw_hash;
1019 } h;
1020
1021 struct module *owner;
1022
1023 char name[32];
1024
1025 struct list_head node;
1026 #ifdef SOCK_REFCNT_DEBUG
1027 atomic_t socks;
1028 #endif
1029 #ifdef CONFIG_MEMCG_KMEM
1030 /*
1031 * cgroup specific init/deinit functions. Called once for all
1032 * protocols that implement it, from cgroups populate function.
1033 * This function has to setup any files the protocol want to
1034 * appear in the kmem cgroup filesystem.
1035 */
1036 int (*init_cgroup)(struct mem_cgroup *memcg,
1037 struct cgroup_subsys *ss);
1038 void (*destroy_cgroup)(struct mem_cgroup *memcg);
1039 struct cg_proto *(*proto_cgroup)(struct mem_cgroup *memcg);
1040 #endif
1041 };
1042
1043 /*
1044 * Bits in struct cg_proto.flags
1045 */
1046 enum cg_proto_flags {
1047 /* Currently active and new sockets should be assigned to cgroups */
1048 MEMCG_SOCK_ACTIVE,
1049 /* It was ever activated; we must disarm static keys on destruction */
1050 MEMCG_SOCK_ACTIVATED,
1051 };
1052
1053 struct cg_proto {
1054 struct res_counter memory_allocated; /* Current allocated memory. */
1055 struct percpu_counter sockets_allocated; /* Current number of sockets. */
1056 int memory_pressure;
1057 long sysctl_mem[3];
1058 unsigned long flags;
1059 /*
1060 * memcg field is used to find which memcg we belong directly
1061 * Each memcg struct can hold more than one cg_proto, so container_of
1062 * won't really cut.
1063 *
1064 * The elegant solution would be having an inverse function to
1065 * proto_cgroup in struct proto, but that means polluting the structure
1066 * for everybody, instead of just for memcg users.
1067 */
1068 struct mem_cgroup *memcg;
1069 };
1070
1071 int proto_register(struct proto *prot, int alloc_slab);
1072 void proto_unregister(struct proto *prot);
1073
1074 static inline bool memcg_proto_active(struct cg_proto *cg_proto)
1075 {
1076 return test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
1077 }
1078
1079 static inline bool memcg_proto_activated(struct cg_proto *cg_proto)
1080 {
1081 return test_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags);
1082 }
1083
1084 #ifdef SOCK_REFCNT_DEBUG
1085 static inline void sk_refcnt_debug_inc(struct sock *sk)
1086 {
1087 atomic_inc(&sk->sk_prot->socks);
1088 }
1089
1090 static inline void sk_refcnt_debug_dec(struct sock *sk)
1091 {
1092 atomic_dec(&sk->sk_prot->socks);
1093 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1094 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1095 }
1096
1097 static inline void sk_refcnt_debug_release(const struct sock *sk)
1098 {
1099 if (atomic_read(&sk->sk_refcnt) != 1)
1100 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1101 sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
1102 }
1103 #else /* SOCK_REFCNT_DEBUG */
1104 #define sk_refcnt_debug_inc(sk) do { } while (0)
1105 #define sk_refcnt_debug_dec(sk) do { } while (0)
1106 #define sk_refcnt_debug_release(sk) do { } while (0)
1107 #endif /* SOCK_REFCNT_DEBUG */
1108
1109 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_NET)
1110 extern struct static_key memcg_socket_limit_enabled;
1111 static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1112 struct cg_proto *cg_proto)
1113 {
1114 return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg));
1115 }
1116 #define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled)
1117 #else
1118 #define mem_cgroup_sockets_enabled 0
1119 static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1120 struct cg_proto *cg_proto)
1121 {
1122 return NULL;
1123 }
1124 #endif
1125
1126 static inline bool sk_stream_memory_free(const struct sock *sk)
1127 {
1128 if (sk->sk_wmem_queued >= sk->sk_sndbuf)
1129 return false;
1130
1131 return sk->sk_prot->stream_memory_free ?
1132 sk->sk_prot->stream_memory_free(sk) : true;
1133 }
1134
1135 static inline bool sk_stream_is_writeable(const struct sock *sk)
1136 {
1137 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1138 sk_stream_memory_free(sk);
1139 }
1140
1141
1142 static inline bool sk_has_memory_pressure(const struct sock *sk)
1143 {
1144 return sk->sk_prot->memory_pressure != NULL;
1145 }
1146
1147 static inline bool sk_under_memory_pressure(const struct sock *sk)
1148 {
1149 if (!sk->sk_prot->memory_pressure)
1150 return false;
1151
1152 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1153 return !!sk->sk_cgrp->memory_pressure;
1154
1155 return !!*sk->sk_prot->memory_pressure;
1156 }
1157
1158 static inline void sk_leave_memory_pressure(struct sock *sk)
1159 {
1160 int *memory_pressure = sk->sk_prot->memory_pressure;
1161
1162 if (!memory_pressure)
1163 return;
1164
1165 if (*memory_pressure)
1166 *memory_pressure = 0;
1167
1168 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1169 struct cg_proto *cg_proto = sk->sk_cgrp;
1170 struct proto *prot = sk->sk_prot;
1171
1172 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1173 cg_proto->memory_pressure = 0;
1174 }
1175
1176 }
1177
1178 static inline void sk_enter_memory_pressure(struct sock *sk)
1179 {
1180 if (!sk->sk_prot->enter_memory_pressure)
1181 return;
1182
1183 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1184 struct cg_proto *cg_proto = sk->sk_cgrp;
1185 struct proto *prot = sk->sk_prot;
1186
1187 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1188 cg_proto->memory_pressure = 1;
1189 }
1190
1191 sk->sk_prot->enter_memory_pressure(sk);
1192 }
1193
1194 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1195 {
1196 long *prot = sk->sk_prot->sysctl_mem;
1197 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1198 prot = sk->sk_cgrp->sysctl_mem;
1199 return prot[index];
1200 }
1201
1202 static inline void memcg_memory_allocated_add(struct cg_proto *prot,
1203 unsigned long amt,
1204 int *parent_status)
1205 {
1206 struct res_counter *fail;
1207 int ret;
1208
1209 ret = res_counter_charge_nofail(&prot->memory_allocated,
1210 amt << PAGE_SHIFT, &fail);
1211 if (ret < 0)
1212 *parent_status = OVER_LIMIT;
1213 }
1214
1215 static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
1216 unsigned long amt)
1217 {
1218 res_counter_uncharge(&prot->memory_allocated, amt << PAGE_SHIFT);
1219 }
1220
1221 static inline u64 memcg_memory_allocated_read(struct cg_proto *prot)
1222 {
1223 u64 ret;
1224 ret = res_counter_read_u64(&prot->memory_allocated, RES_USAGE);
1225 return ret >> PAGE_SHIFT;
1226 }
1227
1228 static inline long
1229 sk_memory_allocated(const struct sock *sk)
1230 {
1231 struct proto *prot = sk->sk_prot;
1232 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1233 return memcg_memory_allocated_read(sk->sk_cgrp);
1234
1235 return atomic_long_read(prot->memory_allocated);
1236 }
1237
1238 static inline long
1239 sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status)
1240 {
1241 struct proto *prot = sk->sk_prot;
1242
1243 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1244 memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status);
1245 /* update the root cgroup regardless */
1246 atomic_long_add_return(amt, prot->memory_allocated);
1247 return memcg_memory_allocated_read(sk->sk_cgrp);
1248 }
1249
1250 return atomic_long_add_return(amt, prot->memory_allocated);
1251 }
1252
1253 static inline void
1254 sk_memory_allocated_sub(struct sock *sk, int amt)
1255 {
1256 struct proto *prot = sk->sk_prot;
1257
1258 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1259 memcg_memory_allocated_sub(sk->sk_cgrp, amt);
1260
1261 atomic_long_sub(amt, prot->memory_allocated);
1262 }
1263
1264 static inline void sk_sockets_allocated_dec(struct sock *sk)
1265 {
1266 struct proto *prot = sk->sk_prot;
1267
1268 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1269 struct cg_proto *cg_proto = sk->sk_cgrp;
1270
1271 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1272 percpu_counter_dec(&cg_proto->sockets_allocated);
1273 }
1274
1275 percpu_counter_dec(prot->sockets_allocated);
1276 }
1277
1278 static inline void sk_sockets_allocated_inc(struct sock *sk)
1279 {
1280 struct proto *prot = sk->sk_prot;
1281
1282 if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1283 struct cg_proto *cg_proto = sk->sk_cgrp;
1284
1285 for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1286 percpu_counter_inc(&cg_proto->sockets_allocated);
1287 }
1288
1289 percpu_counter_inc(prot->sockets_allocated);
1290 }
1291
1292 static inline int
1293 sk_sockets_allocated_read_positive(struct sock *sk)
1294 {
1295 struct proto *prot = sk->sk_prot;
1296
1297 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1298 return percpu_counter_read_positive(&sk->sk_cgrp->sockets_allocated);
1299
1300 return percpu_counter_read_positive(prot->sockets_allocated);
1301 }
1302
1303 static inline int
1304 proto_sockets_allocated_sum_positive(struct proto *prot)
1305 {
1306 return percpu_counter_sum_positive(prot->sockets_allocated);
1307 }
1308
1309 static inline long
1310 proto_memory_allocated(struct proto *prot)
1311 {
1312 return atomic_long_read(prot->memory_allocated);
1313 }
1314
1315 static inline bool
1316 proto_memory_pressure(struct proto *prot)
1317 {
1318 if (!prot->memory_pressure)
1319 return false;
1320 return !!*prot->memory_pressure;
1321 }
1322
1323
1324 #ifdef CONFIG_PROC_FS
1325 /* Called with local bh disabled */
1326 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1327 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1328 #else
1329 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1330 int inc)
1331 {
1332 }
1333 #endif
1334
1335
1336 /* With per-bucket locks this operation is not-atomic, so that
1337 * this version is not worse.
1338 */
1339 static inline void __sk_prot_rehash(struct sock *sk)
1340 {
1341 sk->sk_prot->unhash(sk);
1342 sk->sk_prot->hash(sk);
1343 }
1344
1345 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
1346
1347 /* About 10 seconds */
1348 #define SOCK_DESTROY_TIME (10*HZ)
1349
1350 /* Sockets 0-1023 can't be bound to unless you are superuser */
1351 #define PROT_SOCK 1024
1352
1353 #define SHUTDOWN_MASK 3
1354 #define RCV_SHUTDOWN 1
1355 #define SEND_SHUTDOWN 2
1356
1357 #define SOCK_SNDBUF_LOCK 1
1358 #define SOCK_RCVBUF_LOCK 2
1359 #define SOCK_BINDADDR_LOCK 4
1360 #define SOCK_BINDPORT_LOCK 8
1361
1362 /* sock_iocb: used to kick off async processing of socket ios */
1363 struct sock_iocb {
1364 struct list_head list;
1365
1366 int flags;
1367 int size;
1368 struct socket *sock;
1369 struct sock *sk;
1370 struct scm_cookie *scm;
1371 struct msghdr *msg, async_msg;
1372 struct kiocb *kiocb;
1373 };
1374
1375 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
1376 {
1377 return (struct sock_iocb *)iocb->private;
1378 }
1379
1380 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
1381 {
1382 return si->kiocb;
1383 }
1384
1385 struct socket_alloc {
1386 struct socket socket;
1387 struct inode vfs_inode;
1388 };
1389
1390 static inline struct socket *SOCKET_I(struct inode *inode)
1391 {
1392 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1393 }
1394
1395 static inline struct inode *SOCK_INODE(struct socket *socket)
1396 {
1397 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1398 }
1399
1400 /*
1401 * Functions for memory accounting
1402 */
1403 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1404 void __sk_mem_reclaim(struct sock *sk);
1405
1406 #define SK_MEM_QUANTUM ((int)PAGE_SIZE)
1407 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1408 #define SK_MEM_SEND 0
1409 #define SK_MEM_RECV 1
1410
1411 static inline int sk_mem_pages(int amt)
1412 {
1413 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1414 }
1415
1416 static inline bool sk_has_account(struct sock *sk)
1417 {
1418 /* return true if protocol supports memory accounting */
1419 return !!sk->sk_prot->memory_allocated;
1420 }
1421
1422 static inline bool sk_wmem_schedule(struct sock *sk, 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_SEND);
1428 }
1429
1430 static inline bool
1431 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1432 {
1433 if (!sk_has_account(sk))
1434 return true;
1435 return size<= sk->sk_forward_alloc ||
1436 __sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1437 skb_pfmemalloc(skb);
1438 }
1439
1440 static inline void sk_mem_reclaim(struct sock *sk)
1441 {
1442 if (!sk_has_account(sk))
1443 return;
1444 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1445 __sk_mem_reclaim(sk);
1446 }
1447
1448 static inline void sk_mem_reclaim_partial(struct sock *sk)
1449 {
1450 if (!sk_has_account(sk))
1451 return;
1452 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1453 __sk_mem_reclaim(sk);
1454 }
1455
1456 static inline void sk_mem_charge(struct sock *sk, int size)
1457 {
1458 if (!sk_has_account(sk))
1459 return;
1460 sk->sk_forward_alloc -= size;
1461 }
1462
1463 static inline void sk_mem_uncharge(struct sock *sk, int size)
1464 {
1465 if (!sk_has_account(sk))
1466 return;
1467 sk->sk_forward_alloc += size;
1468 }
1469
1470 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1471 {
1472 sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1473 sk->sk_wmem_queued -= skb->truesize;
1474 sk_mem_uncharge(sk, skb->truesize);
1475 __kfree_skb(skb);
1476 }
1477
1478 /* Used by processes to "lock" a socket state, so that
1479 * interrupts and bottom half handlers won't change it
1480 * from under us. It essentially blocks any incoming
1481 * packets, so that we won't get any new data or any
1482 * packets that change the state of the socket.
1483 *
1484 * While locked, BH processing will add new packets to
1485 * the backlog queue. This queue is processed by the
1486 * owner of the socket lock right before it is released.
1487 *
1488 * Since ~2.3.5 it is also exclusive sleep lock serializing
1489 * accesses from user process context.
1490 */
1491 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned)
1492
1493 static inline void sock_release_ownership(struct sock *sk)
1494 {
1495 sk->sk_lock.owned = 0;
1496 }
1497
1498 /*
1499 * Macro so as to not evaluate some arguments when
1500 * lockdep is not enabled.
1501 *
1502 * Mark both the sk_lock and the sk_lock.slock as a
1503 * per-address-family lock class.
1504 */
1505 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1506 do { \
1507 sk->sk_lock.owned = 0; \
1508 init_waitqueue_head(&sk->sk_lock.wq); \
1509 spin_lock_init(&(sk)->sk_lock.slock); \
1510 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1511 sizeof((sk)->sk_lock)); \
1512 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1513 (skey), (sname)); \
1514 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1515 } while (0)
1516
1517 void lock_sock_nested(struct sock *sk, int subclass);
1518
1519 static inline void lock_sock(struct sock *sk)
1520 {
1521 lock_sock_nested(sk, 0);
1522 }
1523
1524 void release_sock(struct sock *sk);
1525
1526 /* BH context may only use the following locking interface. */
1527 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1528 #define bh_lock_sock_nested(__sk) \
1529 spin_lock_nested(&((__sk)->sk_lock.slock), \
1530 SINGLE_DEPTH_NESTING)
1531 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1532
1533 bool lock_sock_fast(struct sock *sk);
1534 /**
1535 * unlock_sock_fast - complement of lock_sock_fast
1536 * @sk: socket
1537 * @slow: slow mode
1538 *
1539 * fast unlock socket for user context.
1540 * If slow mode is on, we call regular release_sock()
1541 */
1542 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1543 {
1544 if (slow)
1545 release_sock(sk);
1546 else
1547 spin_unlock_bh(&sk->sk_lock.slock);
1548 }
1549
1550
1551 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1552 struct proto *prot);
1553 void sk_free(struct sock *sk);
1554 void sk_release_kernel(struct sock *sk);
1555 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1556
1557 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1558 gfp_t priority);
1559 void sock_wfree(struct sk_buff *skb);
1560 void skb_orphan_partial(struct sk_buff *skb);
1561 void sock_rfree(struct sk_buff *skb);
1562 void sock_edemux(struct sk_buff *skb);
1563
1564 int sock_setsockopt(struct socket *sock, int level, int op,
1565 char __user *optval, unsigned int optlen);
1566
1567 int sock_getsockopt(struct socket *sock, int level, int op,
1568 char __user *optval, int __user *optlen);
1569 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1570 int noblock, int *errcode);
1571 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1572 unsigned long data_len, int noblock,
1573 int *errcode, int max_page_order);
1574 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1575 void sock_kfree_s(struct sock *sk, void *mem, int size);
1576 void sk_send_sigurg(struct sock *sk);
1577
1578 /*
1579 * Functions to fill in entries in struct proto_ops when a protocol
1580 * does not implement a particular function.
1581 */
1582 int sock_no_bind(struct socket *, struct sockaddr *, int);
1583 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1584 int sock_no_socketpair(struct socket *, struct socket *);
1585 int sock_no_accept(struct socket *, struct socket *, int);
1586 int sock_no_getname(struct socket *, struct sockaddr *, int *, int);
1587 unsigned int sock_no_poll(struct file *, struct socket *,
1588 struct poll_table_struct *);
1589 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1590 int sock_no_listen(struct socket *, int);
1591 int sock_no_shutdown(struct socket *, int);
1592 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1593 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1594 int sock_no_sendmsg(struct kiocb *, struct socket *, struct msghdr *, size_t);
1595 int sock_no_recvmsg(struct kiocb *, struct socket *, struct msghdr *, size_t,
1596 int);
1597 int sock_no_mmap(struct file *file, struct socket *sock,
1598 struct vm_area_struct *vma);
1599 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1600 size_t size, int flags);
1601
1602 /*
1603 * Functions to fill in entries in struct proto_ops when a protocol
1604 * uses the inet style.
1605 */
1606 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1607 char __user *optval, int __user *optlen);
1608 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1609 struct msghdr *msg, size_t size, int flags);
1610 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1611 char __user *optval, unsigned int optlen);
1612 int compat_sock_common_getsockopt(struct socket *sock, int level,
1613 int optname, char __user *optval, int __user *optlen);
1614 int compat_sock_common_setsockopt(struct socket *sock, int level,
1615 int optname, char __user *optval, unsigned int optlen);
1616
1617 void sk_common_release(struct sock *sk);
1618
1619 /*
1620 * Default socket callbacks and setup code
1621 */
1622
1623 /* Initialise core socket variables */
1624 void sock_init_data(struct socket *sock, struct sock *sk);
1625
1626 /*
1627 * Socket reference counting postulates.
1628 *
1629 * * Each user of socket SHOULD hold a reference count.
1630 * * Each access point to socket (an hash table bucket, reference from a list,
1631 * running timer, skb in flight MUST hold a reference count.
1632 * * When reference count hits 0, it means it will never increase back.
1633 * * When reference count hits 0, it means that no references from
1634 * outside exist to this socket and current process on current CPU
1635 * is last user and may/should destroy this socket.
1636 * * sk_free is called from any context: process, BH, IRQ. When
1637 * it is called, socket has no references from outside -> sk_free
1638 * may release descendant resources allocated by the socket, but
1639 * to the time when it is called, socket is NOT referenced by any
1640 * hash tables, lists etc.
1641 * * Packets, delivered from outside (from network or from another process)
1642 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1643 * when they sit in queue. Otherwise, packets will leak to hole, when
1644 * socket is looked up by one cpu and unhasing is made by another CPU.
1645 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1646 * (leak to backlog). Packet socket does all the processing inside
1647 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1648 * use separate SMP lock, so that they are prone too.
1649 */
1650
1651 /* Ungrab socket and destroy it, if it was the last reference. */
1652 static inline void sock_put(struct sock *sk)
1653 {
1654 if (atomic_dec_and_test(&sk->sk_refcnt))
1655 sk_free(sk);
1656 }
1657 /* Generic version of sock_put(), dealing with all sockets
1658 * (TCP_TIMEWAIT, ESTABLISHED...)
1659 */
1660 void sock_gen_put(struct sock *sk);
1661
1662 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested);
1663
1664 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1665 {
1666 sk->sk_tx_queue_mapping = tx_queue;
1667 }
1668
1669 static inline void sk_tx_queue_clear(struct sock *sk)
1670 {
1671 sk->sk_tx_queue_mapping = -1;
1672 }
1673
1674 static inline int sk_tx_queue_get(const struct sock *sk)
1675 {
1676 return sk ? sk->sk_tx_queue_mapping : -1;
1677 }
1678
1679 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1680 {
1681 sk_tx_queue_clear(sk);
1682 sk->sk_socket = sock;
1683 }
1684
1685 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1686 {
1687 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1688 return &rcu_dereference_raw(sk->sk_wq)->wait;
1689 }
1690 /* Detach socket from process context.
1691 * Announce socket dead, detach it from wait queue and inode.
1692 * Note that parent inode held reference count on this struct sock,
1693 * we do not release it in this function, because protocol
1694 * probably wants some additional cleanups or even continuing
1695 * to work with this socket (TCP).
1696 */
1697 static inline void sock_orphan(struct sock *sk)
1698 {
1699 write_lock_bh(&sk->sk_callback_lock);
1700 sock_set_flag(sk, SOCK_DEAD);
1701 sk_set_socket(sk, NULL);
1702 sk->sk_wq = NULL;
1703 write_unlock_bh(&sk->sk_callback_lock);
1704 }
1705
1706 static inline void sock_graft(struct sock *sk, struct socket *parent)
1707 {
1708 write_lock_bh(&sk->sk_callback_lock);
1709 sk->sk_wq = parent->wq;
1710 parent->sk = sk;
1711 sk_set_socket(sk, parent);
1712 security_sock_graft(sk, parent);
1713 write_unlock_bh(&sk->sk_callback_lock);
1714 }
1715
1716 kuid_t sock_i_uid(struct sock *sk);
1717 unsigned long sock_i_ino(struct sock *sk);
1718
1719 static inline struct dst_entry *
1720 __sk_dst_get(struct sock *sk)
1721 {
1722 return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1723 lockdep_is_held(&sk->sk_lock.slock));
1724 }
1725
1726 static inline struct dst_entry *
1727 sk_dst_get(struct sock *sk)
1728 {
1729 struct dst_entry *dst;
1730
1731 rcu_read_lock();
1732 dst = rcu_dereference(sk->sk_dst_cache);
1733 if (dst)
1734 dst_hold(dst);
1735 rcu_read_unlock();
1736 return dst;
1737 }
1738
1739 static inline void dst_negative_advice(struct sock *sk)
1740 {
1741 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1742
1743 if (dst && dst->ops->negative_advice) {
1744 ndst = dst->ops->negative_advice(dst);
1745
1746 if (ndst != dst) {
1747 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1748 sk_tx_queue_clear(sk);
1749 }
1750 }
1751 }
1752
1753 static inline void
1754 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1755 {
1756 struct dst_entry *old_dst;
1757
1758 sk_tx_queue_clear(sk);
1759 /*
1760 * This can be called while sk is owned by the caller only,
1761 * with no state that can be checked in a rcu_dereference_check() cond
1762 */
1763 old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1764 rcu_assign_pointer(sk->sk_dst_cache, dst);
1765 dst_release(old_dst);
1766 }
1767
1768 static inline void
1769 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1770 {
1771 spin_lock(&sk->sk_dst_lock);
1772 __sk_dst_set(sk, dst);
1773 spin_unlock(&sk->sk_dst_lock);
1774 }
1775
1776 static inline void
1777 __sk_dst_reset(struct sock *sk)
1778 {
1779 __sk_dst_set(sk, NULL);
1780 }
1781
1782 static inline void
1783 sk_dst_reset(struct sock *sk)
1784 {
1785 spin_lock(&sk->sk_dst_lock);
1786 __sk_dst_reset(sk);
1787 spin_unlock(&sk->sk_dst_lock);
1788 }
1789
1790 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1791
1792 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1793
1794 static inline bool sk_can_gso(const struct sock *sk)
1795 {
1796 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1797 }
1798
1799 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1800
1801 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1802 {
1803 sk->sk_route_nocaps |= flags;
1804 sk->sk_route_caps &= ~flags;
1805 }
1806
1807 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1808 char __user *from, char *to,
1809 int copy, int offset)
1810 {
1811 if (skb->ip_summed == CHECKSUM_NONE) {
1812 int err = 0;
1813 __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1814 if (err)
1815 return err;
1816 skb->csum = csum_block_add(skb->csum, csum, offset);
1817 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1818 if (!access_ok(VERIFY_READ, from, copy) ||
1819 __copy_from_user_nocache(to, from, copy))
1820 return -EFAULT;
1821 } else if (copy_from_user(to, from, copy))
1822 return -EFAULT;
1823
1824 return 0;
1825 }
1826
1827 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1828 char __user *from, int copy)
1829 {
1830 int err, offset = skb->len;
1831
1832 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1833 copy, offset);
1834 if (err)
1835 __skb_trim(skb, offset);
1836
1837 return err;
1838 }
1839
1840 static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1841 struct sk_buff *skb,
1842 struct page *page,
1843 int off, int copy)
1844 {
1845 int err;
1846
1847 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1848 copy, skb->len);
1849 if (err)
1850 return err;
1851
1852 skb->len += copy;
1853 skb->data_len += copy;
1854 skb->truesize += copy;
1855 sk->sk_wmem_queued += copy;
1856 sk_mem_charge(sk, copy);
1857 return 0;
1858 }
1859
1860 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1861 struct sk_buff *skb, struct page *page,
1862 int off, int copy)
1863 {
1864 if (skb->ip_summed == CHECKSUM_NONE) {
1865 int err = 0;
1866 __wsum csum = csum_and_copy_from_user(from,
1867 page_address(page) + off,
1868 copy, 0, &err);
1869 if (err)
1870 return err;
1871 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1872 } else if (copy_from_user(page_address(page) + off, from, copy))
1873 return -EFAULT;
1874
1875 skb->len += copy;
1876 skb->data_len += copy;
1877 skb->truesize += copy;
1878 sk->sk_wmem_queued += copy;
1879 sk_mem_charge(sk, copy);
1880 return 0;
1881 }
1882
1883 /**
1884 * sk_wmem_alloc_get - returns write allocations
1885 * @sk: socket
1886 *
1887 * Returns sk_wmem_alloc minus initial offset of one
1888 */
1889 static inline int sk_wmem_alloc_get(const struct sock *sk)
1890 {
1891 return atomic_read(&sk->sk_wmem_alloc) - 1;
1892 }
1893
1894 /**
1895 * sk_rmem_alloc_get - returns read allocations
1896 * @sk: socket
1897 *
1898 * Returns sk_rmem_alloc
1899 */
1900 static inline int sk_rmem_alloc_get(const struct sock *sk)
1901 {
1902 return atomic_read(&sk->sk_rmem_alloc);
1903 }
1904
1905 /**
1906 * sk_has_allocations - check if allocations are outstanding
1907 * @sk: socket
1908 *
1909 * Returns true if socket has write or read allocations
1910 */
1911 static inline bool sk_has_allocations(const struct sock *sk)
1912 {
1913 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1914 }
1915
1916 /**
1917 * wq_has_sleeper - check if there are any waiting processes
1918 * @wq: struct socket_wq
1919 *
1920 * Returns true if socket_wq has waiting processes
1921 *
1922 * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1923 * barrier call. They were added due to the race found within the tcp code.
1924 *
1925 * Consider following tcp code paths:
1926 *
1927 * CPU1 CPU2
1928 *
1929 * sys_select receive packet
1930 * ... ...
1931 * __add_wait_queue update tp->rcv_nxt
1932 * ... ...
1933 * tp->rcv_nxt check sock_def_readable
1934 * ... {
1935 * schedule rcu_read_lock();
1936 * wq = rcu_dereference(sk->sk_wq);
1937 * if (wq && waitqueue_active(&wq->wait))
1938 * wake_up_interruptible(&wq->wait)
1939 * ...
1940 * }
1941 *
1942 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1943 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
1944 * could then endup calling schedule and sleep forever if there are no more
1945 * data on the socket.
1946 *
1947 */
1948 static inline bool wq_has_sleeper(struct socket_wq *wq)
1949 {
1950 /* We need to be sure we are in sync with the
1951 * add_wait_queue modifications to the wait queue.
1952 *
1953 * This memory barrier is paired in the sock_poll_wait.
1954 */
1955 smp_mb();
1956 return wq && waitqueue_active(&wq->wait);
1957 }
1958
1959 /**
1960 * sock_poll_wait - place memory barrier behind the poll_wait call.
1961 * @filp: file
1962 * @wait_address: socket wait queue
1963 * @p: poll_table
1964 *
1965 * See the comments in the wq_has_sleeper function.
1966 */
1967 static inline void sock_poll_wait(struct file *filp,
1968 wait_queue_head_t *wait_address, poll_table *p)
1969 {
1970 if (!poll_does_not_wait(p) && wait_address) {
1971 poll_wait(filp, wait_address, p);
1972 /* We need to be sure we are in sync with the
1973 * socket flags modification.
1974 *
1975 * This memory barrier is paired in the wq_has_sleeper.
1976 */
1977 smp_mb();
1978 }
1979 }
1980
1981 /*
1982 * Queue a received datagram if it will fit. Stream and sequenced
1983 * protocols can't normally use this as they need to fit buffers in
1984 * and play with them.
1985 *
1986 * Inlined as it's very short and called for pretty much every
1987 * packet ever received.
1988 */
1989
1990 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1991 {
1992 skb_orphan(skb);
1993 skb->sk = sk;
1994 skb->destructor = sock_wfree;
1995 /*
1996 * We used to take a refcount on sk, but following operation
1997 * is enough to guarantee sk_free() wont free this sock until
1998 * all in-flight packets are completed
1999 */
2000 atomic_add(skb->truesize, &sk->sk_wmem_alloc);
2001 }
2002
2003 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2004 {
2005 skb_orphan(skb);
2006 skb->sk = sk;
2007 skb->destructor = sock_rfree;
2008 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2009 sk_mem_charge(sk, skb->truesize);
2010 }
2011
2012 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2013 unsigned long expires);
2014
2015 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2016
2017 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2018
2019 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2020
2021 /*
2022 * Recover an error report and clear atomically
2023 */
2024
2025 static inline int sock_error(struct sock *sk)
2026 {
2027 int err;
2028 if (likely(!sk->sk_err))
2029 return 0;
2030 err = xchg(&sk->sk_err, 0);
2031 return -err;
2032 }
2033
2034 static inline unsigned long sock_wspace(struct sock *sk)
2035 {
2036 int amt = 0;
2037
2038 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2039 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
2040 if (amt < 0)
2041 amt = 0;
2042 }
2043 return amt;
2044 }
2045
2046 static inline void sk_wake_async(struct sock *sk, int how, int band)
2047 {
2048 if (sock_flag(sk, SOCK_FASYNC))
2049 sock_wake_async(sk->sk_socket, how, band);
2050 }
2051
2052 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2053 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2054 * Note: for send buffers, TCP works better if we can build two skbs at
2055 * minimum.
2056 */
2057 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2058
2059 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
2060 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
2061
2062 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2063 {
2064 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
2065 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2066 sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
2067 }
2068 }
2069
2070 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
2071
2072 /**
2073 * sk_page_frag - return an appropriate page_frag
2074 * @sk: socket
2075 *
2076 * If socket allocation mode allows current thread to sleep, it means its
2077 * safe to use the per task page_frag instead of the per socket one.
2078 */
2079 static inline struct page_frag *sk_page_frag(struct sock *sk)
2080 {
2081 if (sk->sk_allocation & __GFP_WAIT)
2082 return &current->task_frag;
2083
2084 return &sk->sk_frag;
2085 }
2086
2087 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2088
2089 /*
2090 * Default write policy as shown to user space via poll/select/SIGIO
2091 */
2092 static inline bool sock_writeable(const struct sock *sk)
2093 {
2094 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2095 }
2096
2097 static inline gfp_t gfp_any(void)
2098 {
2099 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2100 }
2101
2102 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2103 {
2104 return noblock ? 0 : sk->sk_rcvtimeo;
2105 }
2106
2107 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2108 {
2109 return noblock ? 0 : sk->sk_sndtimeo;
2110 }
2111
2112 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2113 {
2114 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2115 }
2116
2117 /* Alas, with timeout socket operations are not restartable.
2118 * Compare this to poll().
2119 */
2120 static inline int sock_intr_errno(long timeo)
2121 {
2122 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2123 }
2124
2125 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2126 struct sk_buff *skb);
2127 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2128 struct sk_buff *skb);
2129
2130 static inline void
2131 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2132 {
2133 ktime_t kt = skb->tstamp;
2134 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2135
2136 /*
2137 * generate control messages if
2138 * - receive time stamping in software requested (SOCK_RCVTSTAMP
2139 * or SOCK_TIMESTAMPING_RX_SOFTWARE)
2140 * - software time stamp available and wanted
2141 * (SOCK_TIMESTAMPING_SOFTWARE)
2142 * - hardware time stamps available and wanted
2143 * (SOCK_TIMESTAMPING_SYS_HARDWARE or
2144 * SOCK_TIMESTAMPING_RAW_HARDWARE)
2145 */
2146 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2147 sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) ||
2148 (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) ||
2149 (hwtstamps->hwtstamp.tv64 &&
2150 sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) ||
2151 (hwtstamps->syststamp.tv64 &&
2152 sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE)))
2153 __sock_recv_timestamp(msg, sk, skb);
2154 else
2155 sk->sk_stamp = kt;
2156
2157 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2158 __sock_recv_wifi_status(msg, sk, skb);
2159 }
2160
2161 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2162 struct sk_buff *skb);
2163
2164 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2165 struct sk_buff *skb)
2166 {
2167 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2168 (1UL << SOCK_RCVTSTAMP) | \
2169 (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \
2170 (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \
2171 (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE))
2172
2173 if (sk->sk_flags & FLAGS_TS_OR_DROPS)
2174 __sock_recv_ts_and_drops(msg, sk, skb);
2175 else
2176 sk->sk_stamp = skb->tstamp;
2177 }
2178
2179 /**
2180 * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2181 * @sk: socket sending this packet
2182 * @tx_flags: filled with instructions for time stamping
2183 *
2184 * Currently only depends on SOCK_TIMESTAMPING* flags.
2185 */
2186 void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags);
2187
2188 /**
2189 * sk_eat_skb - Release a skb if it is no longer needed
2190 * @sk: socket to eat this skb from
2191 * @skb: socket buffer to eat
2192 * @copied_early: flag indicating whether DMA operations copied this data early
2193 *
2194 * This routine must be called with interrupts disabled or with the socket
2195 * locked so that the sk_buff queue operation is ok.
2196 */
2197 #ifdef CONFIG_NET_DMA
2198 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2199 {
2200 __skb_unlink(skb, &sk->sk_receive_queue);
2201 if (!copied_early)
2202 __kfree_skb(skb);
2203 else
2204 __skb_queue_tail(&sk->sk_async_wait_queue, skb);
2205 }
2206 #else
2207 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, bool copied_early)
2208 {
2209 __skb_unlink(skb, &sk->sk_receive_queue);
2210 __kfree_skb(skb);
2211 }
2212 #endif
2213
2214 static inline
2215 struct net *sock_net(const struct sock *sk)
2216 {
2217 return read_pnet(&sk->sk_net);
2218 }
2219
2220 static inline
2221 void sock_net_set(struct sock *sk, struct net *net)
2222 {
2223 write_pnet(&sk->sk_net, net);
2224 }
2225
2226 /*
2227 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
2228 * They should not hold a reference to a namespace in order to allow
2229 * to stop it.
2230 * Sockets after sk_change_net should be released using sk_release_kernel
2231 */
2232 static inline void sk_change_net(struct sock *sk, struct net *net)
2233 {
2234 struct net *current_net = sock_net(sk);
2235
2236 if (!net_eq(current_net, net)) {
2237 put_net(current_net);
2238 sock_net_set(sk, hold_net(net));
2239 }
2240 }
2241
2242 static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2243 {
2244 if (skb->sk) {
2245 struct sock *sk = skb->sk;
2246
2247 skb->destructor = NULL;
2248 skb->sk = NULL;
2249 return sk;
2250 }
2251 return NULL;
2252 }
2253
2254 void sock_enable_timestamp(struct sock *sk, int flag);
2255 int sock_get_timestamp(struct sock *, struct timeval __user *);
2256 int sock_get_timestampns(struct sock *, struct timespec __user *);
2257 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2258 int type);
2259
2260 bool sk_ns_capable(const struct sock *sk,
2261 struct user_namespace *user_ns, int cap);
2262 bool sk_capable(const struct sock *sk, int cap);
2263 bool sk_net_capable(const struct sock *sk, int cap);
2264
2265 /*
2266 * Enable debug/info messages
2267 */
2268 extern int net_msg_warn;
2269 #define NETDEBUG(fmt, args...) \
2270 do { if (net_msg_warn) printk(fmt,##args); } while (0)
2271
2272 #define LIMIT_NETDEBUG(fmt, args...) \
2273 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
2274
2275 extern __u32 sysctl_wmem_max;
2276 extern __u32 sysctl_rmem_max;
2277
2278 extern int sysctl_optmem_max;
2279
2280 extern __u32 sysctl_wmem_default;
2281 extern __u32 sysctl_rmem_default;
2282
2283 #endif /* _SOCK_H */
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