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, <bir7@leland.Stanford.Edu>
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/config.h>
44 #include <linux/list.h>
45 #include <linux/timer.h>
46 #include <linux/cache.h>
47 #include <linux/module.h>
48 #include <linux/netdevice.h>
49 #include <linux/skbuff.h> /* struct sk_buff */
50 #include <linux/security.h>
51
52 #include <linux/filter.h>
53
54 #include <asm/atomic.h>
55 #include <net/dst.h>
56 #include <net/checksum.h>
57
58 /*
59 * This structure really needs to be cleaned up.
60 * Most of it is for TCP, and not used by any of
61 * the other protocols.
62 */
63
64 /* Define this to get the sk->sk_debug debugging facility. */
65 #define SOCK_DEBUGGING
66 #ifdef SOCK_DEBUGGING
67 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && ((sk)->sk_debug)) \
68 printk(KERN_DEBUG msg); } while (0)
69 #else
70 #define SOCK_DEBUG(sk, msg...) do { } while (0)
71 #endif
72
73 /* This is the per-socket lock. The spinlock provides a synchronization
74 * between user contexts and software interrupt processing, whereas the
75 * mini-semaphore synchronizes multiple users amongst themselves.
76 */
77 struct sock_iocb;
78 typedef struct {
79 spinlock_t slock;
80 struct sock_iocb *owner;
81 wait_queue_head_t wq;
82 } socket_lock_t;
83
84 #define sock_lock_init(__sk) \
85 do { spin_lock_init(&((__sk)->sk_lock.slock)); \
86 (__sk)->sk_lock.owner = NULL; \
87 init_waitqueue_head(&((__sk)->sk_lock.wq)); \
88 } while(0)
89
90 struct sock;
91
92 /**
93 * struct sock_common - minimal network layer representation of sockets
94 * @skc_family - network address family
95 * @skc_state - Connection state
96 * @skc_reuse - %SO_REUSEADDR setting
97 * @skc_bound_dev_if - bound device index if != 0
98 * @skc_node - main hash linkage for various protocol lookup tables
99 * @skc_bind_node - bind hash linkage for various protocol lookup tables
100 * @skc_refcnt - reference count
101 *
102 * This is the minimal network layer representation of sockets, the header
103 * for struct sock and struct tcp_tw_bucket.
104 */
105 struct sock_common {
106 unsigned short skc_family;
107 volatile unsigned char skc_state;
108 unsigned char skc_reuse;
109 int skc_bound_dev_if;
110 struct hlist_node skc_node;
111 struct hlist_node skc_bind_node;
112 atomic_t skc_refcnt;
113 };
114
115 /**
116 * struct sock - network layer representation of sockets
117 * @__sk_common - shared layout with tcp_tw_bucket
118 * @sk_zapped - ax25 & ipx means !linked
119 * @sk_shutdown - mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
120 * @sk_use_write_queue - wheter to call sk->sk_write_space in sock_wfree
121 * @sk_userlocks - %SO_SNDBUF and %SO_RCVBUF settings
122 * @sk_lock - synchronizer
123 * @sk_rcvbuf - size of receive buffer in bytes
124 * @sk_sleep - sock wait queue
125 * @sk_dst_cache - destination cache
126 * @sk_dst_lock - destination cache lock
127 * @sk_policy - flow policy
128 * @sk_rmem_alloc - receive queue bytes committed
129 * @sk_receive_queue - incoming packets
130 * @sk_wmem_alloc - transmit queue bytes committed
131 * @sk_write_queue - Packet sending queue
132 * @sk_omem_alloc - "o" is "option" or "other"
133 * @sk_wmem_queued - persistent queue size
134 * @sk_forward_alloc - space allocated forward
135 * @sk_allocation - allocation mode
136 * @sk_sndbuf - size of send buffer in bytes
137 * @sk_flags - %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, %SO_OOBINLINE settings
138 * @sk_no_check - %SO_NO_CHECK setting, wether or not checkup packets
139 * @sk_debug - %SO_DEBUG setting
140 * @sk_rcvtstamp - %SO_TIMESTAMP setting
141 * @sk_no_largesend - whether to sent large segments or not
142 * @sk_route_caps - route capabilities (e.g. %NETIF_F_TSO)
143 * @sk_lingertime - %SO_LINGER l_linger setting
144 * @sk_hashent - hash entry in several tables (e.g. tcp_ehash)
145 * @sk_backlog - always used with the per-socket spinlock held
146 * @sk_callback_lock - used with the callbacks in the end of this struct
147 * @sk_error_queue - rarely used
148 * @sk_prot - protocol handlers inside a network family
149 * @sk_err - last error
150 * @sk_err_soft - errors that don't cause failure but are the cause of a persistent failure not just 'timed out'
151 * @sk_ack_backlog - current listen backlog
152 * @sk_max_ack_backlog - listen backlog set in listen()
153 * @sk_priority - %SO_PRIORITY setting
154 * @sk_type - socket type (%SOCK_STREAM, etc)
155 * @sk_localroute - route locally only, %SO_DONTROUTE setting
156 * @sk_protocol - which protocol this socket belongs in this network family
157 * @sk_peercred - %SO_PEERCRED setting
158 * @sk_rcvlowat - %SO_RCVLOWAT setting
159 * @sk_rcvtimeo - %SO_RCVTIMEO setting
160 * @sk_sndtimeo - %SO_SNDTIMEO setting
161 * @sk_filter - socket filtering instructions
162 * @sk_protinfo - private area, net family specific, when not using slab
163 * @sk_slab - the slabcache this instance was allocated from
164 * @sk_timer - sock cleanup timer
165 * @sk_stamp - time stamp of last packet received
166 * @sk_socket - Identd and reporting IO signals
167 * @sk_user_data - RPC layer private data
168 * @sk_owner - module that owns this socket
169 * @sk_sndmsg_page - cached page for sendmsg
170 * @sk_sndmsg_off - cached offset for sendmsg
171 * @sk_send_head - front of stuff to transmit
172 * @sk_write_pending - a write to stream socket waits to start
173 * @sk_queue_shrunk - write queue has been shrunk recently
174 * @sk_state_change - callback to indicate change in the state of the sock
175 * @sk_data_ready - callback to indicate there is data to be processed
176 * @sk_write_space - callback to indicate there is bf sending space available
177 * @sk_error_report - callback to indicate errors (e.g. %MSG_ERRQUEUE)
178 * @sk_backlog_rcv - callback to process the backlog
179 * @sk_destruct - called at sock freeing time, i.e. when all refcnt == 0
180 */
181 struct sock {
182 /*
183 * Now struct tcp_tw_bucket also uses sock_common, so please just
184 * don't add nothing before this first member (__sk_common) --acme
185 */
186 struct sock_common __sk_common;
187 #define sk_family __sk_common.skc_family
188 #define sk_state __sk_common.skc_state
189 #define sk_reuse __sk_common.skc_reuse
190 #define sk_bound_dev_if __sk_common.skc_bound_dev_if
191 #define sk_node __sk_common.skc_node
192 #define sk_bind_node __sk_common.skc_bind_node
193 #define sk_refcnt __sk_common.skc_refcnt
194 volatile unsigned char sk_zapped;
195 unsigned char sk_shutdown;
196 unsigned char sk_use_write_queue;
197 unsigned char sk_userlocks;
198 socket_lock_t sk_lock;
199 int sk_rcvbuf;
200 wait_queue_head_t *sk_sleep;
201 struct dst_entry *sk_dst_cache;
202 rwlock_t sk_dst_lock;
203 struct xfrm_policy *sk_policy[2];
204 atomic_t sk_rmem_alloc;
205 struct sk_buff_head sk_receive_queue;
206 atomic_t sk_wmem_alloc;
207 struct sk_buff_head sk_write_queue;
208 atomic_t sk_omem_alloc;
209 int sk_wmem_queued;
210 int sk_forward_alloc;
211 unsigned int sk_allocation;
212 int sk_sndbuf;
213 unsigned long sk_flags;
214 char sk_no_check;
215 unsigned char sk_debug;
216 unsigned char sk_rcvtstamp;
217 unsigned char sk_no_largesend;
218 int sk_route_caps;
219 unsigned long sk_lingertime;
220 int sk_hashent;
221 /*
222 * The backlog queue is special, it is always used with
223 * the per-socket spinlock held and requires low latency
224 * access. Therefore we special case it's implementation.
225 */
226 struct {
227 struct sk_buff *head;
228 struct sk_buff *tail;
229 } sk_backlog;
230 rwlock_t sk_callback_lock;
231 struct sk_buff_head sk_error_queue;
232 struct proto *sk_prot;
233 int sk_err,
234 sk_err_soft;
235 unsigned short sk_ack_backlog;
236 unsigned short sk_max_ack_backlog;
237 __u32 sk_priority;
238 unsigned short sk_type;
239 unsigned char sk_localroute;
240 unsigned char sk_protocol;
241 struct ucred sk_peercred;
242 int sk_rcvlowat;
243 long sk_rcvtimeo;
244 long sk_sndtimeo;
245 struct sk_filter *sk_filter;
246 void *sk_protinfo;
247 kmem_cache_t *sk_slab;
248 struct timer_list sk_timer;
249 struct timeval sk_stamp;
250 struct socket *sk_socket;
251 void *sk_user_data;
252 struct module *sk_owner;
253 struct page *sk_sndmsg_page;
254 __u32 sk_sndmsg_off;
255 struct sk_buff *sk_send_head;
256 int sk_write_pending;
257 void *sk_security;
258 __u8 sk_queue_shrunk;
259 /* three bytes hole, try to pack */
260 void (*sk_state_change)(struct sock *sk);
261 void (*sk_data_ready)(struct sock *sk, int bytes);
262 void (*sk_write_space)(struct sock *sk);
263 void (*sk_error_report)(struct sock *sk);
264 int (*sk_backlog_rcv)(struct sock *sk,
265 struct sk_buff *skb);
266 void (*sk_destruct)(struct sock *sk);
267 };
268
269 /*
270 * Hashed lists helper routines
271 */
272 static inline struct sock *__sk_head(struct hlist_head *head)
273 {
274 return hlist_entry(head->first, struct sock, sk_node);
275 }
276
277 static inline struct sock *sk_head(struct hlist_head *head)
278 {
279 return hlist_empty(head) ? NULL : __sk_head(head);
280 }
281
282 static inline struct sock *sk_next(struct sock *sk)
283 {
284 return sk->sk_node.next ?
285 hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
286 }
287
288 static inline int sk_unhashed(struct sock *sk)
289 {
290 return hlist_unhashed(&sk->sk_node);
291 }
292
293 static inline int sk_hashed(struct sock *sk)
294 {
295 return sk->sk_node.pprev != NULL;
296 }
297
298 static __inline__ void sk_node_init(struct hlist_node *node)
299 {
300 node->pprev = NULL;
301 }
302
303 static __inline__ void __sk_del_node(struct sock *sk)
304 {
305 __hlist_del(&sk->sk_node);
306 }
307
308 static __inline__ int __sk_del_node_init(struct sock *sk)
309 {
310 if (sk_hashed(sk)) {
311 __sk_del_node(sk);
312 sk_node_init(&sk->sk_node);
313 return 1;
314 }
315 return 0;
316 }
317
318 /* Grab socket reference count. This operation is valid only
319 when sk is ALREADY grabbed f.e. it is found in hash table
320 or a list and the lookup is made under lock preventing hash table
321 modifications.
322 */
323
324 static inline void sock_hold(struct sock *sk)
325 {
326 atomic_inc(&sk->sk_refcnt);
327 }
328
329 /* Ungrab socket in the context, which assumes that socket refcnt
330 cannot hit zero, f.e. it is true in context of any socketcall.
331 */
332 static inline void __sock_put(struct sock *sk)
333 {
334 atomic_dec(&sk->sk_refcnt);
335 }
336
337 static __inline__ int sk_del_node_init(struct sock *sk)
338 {
339 int rc = __sk_del_node_init(sk);
340
341 if (rc) {
342 /* paranoid for a while -acme */
343 WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
344 __sock_put(sk);
345 }
346 return rc;
347 }
348
349 static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list)
350 {
351 hlist_add_head(&sk->sk_node, list);
352 }
353
354 static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list)
355 {
356 sock_hold(sk);
357 __sk_add_node(sk, list);
358 }
359
360 static __inline__ void __sk_del_bind_node(struct sock *sk)
361 {
362 __hlist_del(&sk->sk_bind_node);
363 }
364
365 static __inline__ void sk_add_bind_node(struct sock *sk,
366 struct hlist_head *list)
367 {
368 hlist_add_head(&sk->sk_bind_node, list);
369 }
370
371 #define sk_for_each(__sk, node, list) \
372 hlist_for_each_entry(__sk, node, list, sk_node)
373 #define sk_for_each_from(__sk, node) \
374 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
375 hlist_for_each_entry_from(__sk, node, sk_node)
376 #define sk_for_each_continue(__sk, node) \
377 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
378 hlist_for_each_entry_continue(__sk, node, sk_node)
379 #define sk_for_each_safe(__sk, node, tmp, list) \
380 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
381 #define sk_for_each_bound(__sk, node, list) \
382 hlist_for_each_entry(__sk, node, list, sk_bind_node)
383
384 /* Sock flags */
385 enum sock_flags {
386 SOCK_DEAD,
387 SOCK_DONE,
388 SOCK_URGINLINE,
389 SOCK_KEEPOPEN,
390 SOCK_LINGER,
391 SOCK_DESTROY,
392 SOCK_BROADCAST,
393 SOCK_TIMESTAMP,
394 };
395
396 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
397 {
398 __set_bit(flag, &sk->sk_flags);
399 }
400
401 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
402 {
403 __clear_bit(flag, &sk->sk_flags);
404 }
405
406 static inline int sock_flag(struct sock *sk, enum sock_flags flag)
407 {
408 return test_bit(flag, &sk->sk_flags);
409 }
410
411 static inline void sk_acceptq_removed(struct sock *sk)
412 {
413 sk->sk_ack_backlog--;
414 }
415
416 static inline void sk_acceptq_added(struct sock *sk)
417 {
418 sk->sk_ack_backlog++;
419 }
420
421 static inline int sk_acceptq_is_full(struct sock *sk)
422 {
423 return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
424 }
425
426 /*
427 * Compute minimal free write space needed to queue new packets.
428 */
429 static inline int sk_stream_min_wspace(struct sock *sk)
430 {
431 return sk->sk_wmem_queued / 2;
432 }
433
434 static inline int sk_stream_wspace(struct sock *sk)
435 {
436 return sk->sk_sndbuf - sk->sk_wmem_queued;
437 }
438
439 extern void sk_stream_write_space(struct sock *sk);
440
441 static inline int sk_stream_memory_free(struct sock *sk)
442 {
443 return sk->sk_wmem_queued < sk->sk_sndbuf;
444 }
445
446 extern void sk_stream_rfree(struct sk_buff *skb);
447
448 static inline void sk_stream_set_owner_r(struct sk_buff *skb, struct sock *sk)
449 {
450 skb->sk = sk;
451 skb->destructor = sk_stream_rfree;
452 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
453 sk->sk_forward_alloc -= skb->truesize;
454 }
455
456 static inline void sk_stream_free_skb(struct sock *sk, struct sk_buff *skb)
457 {
458 sk->sk_queue_shrunk = 1;
459 sk->sk_wmem_queued -= skb->truesize;
460 sk->sk_forward_alloc += skb->truesize;
461 __kfree_skb(skb);
462 }
463
464 /* The per-socket spinlock must be held here. */
465 #define sk_add_backlog(__sk, __skb) \
466 do { if (!(__sk)->sk_backlog.tail) { \
467 (__sk)->sk_backlog.head = \
468 (__sk)->sk_backlog.tail = (__skb); \
469 } else { \
470 ((__sk)->sk_backlog.tail)->next = (__skb); \
471 (__sk)->sk_backlog.tail = (__skb); \
472 } \
473 (__skb)->next = NULL; \
474 } while(0)
475
476 #define sk_wait_event(__sk, __timeo, __condition) \
477 ({ int rc; \
478 release_sock(__sk); \
479 rc = __condition; \
480 if (!rc) { \
481 *(__timeo) = schedule_timeout(*(__timeo)); \
482 rc = __condition; \
483 } \
484 lock_sock(__sk); \
485 rc; \
486 })
487
488 extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
489 extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
490 extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
491 extern int sk_stream_error(struct sock *sk, int flags, int err);
492 extern void sk_stream_kill_queues(struct sock *sk);
493
494 extern int sk_wait_data(struct sock *sk, long *timeo);
495
496 /* Networking protocol blocks we attach to sockets.
497 * socket layer -> transport layer interface
498 * transport -> network interface is defined by struct inet_proto
499 */
500 struct proto {
501 void (*close)(struct sock *sk,
502 long timeout);
503 int (*connect)(struct sock *sk,
504 struct sockaddr *uaddr,
505 int addr_len);
506 int (*disconnect)(struct sock *sk, int flags);
507
508 struct sock * (*accept) (struct sock *sk, int flags, int *err);
509
510 int (*ioctl)(struct sock *sk, int cmd,
511 unsigned long arg);
512 int (*init)(struct sock *sk);
513 int (*destroy)(struct sock *sk);
514 void (*shutdown)(struct sock *sk, int how);
515 int (*setsockopt)(struct sock *sk, int level,
516 int optname, char __user *optval,
517 int optlen);
518 int (*getsockopt)(struct sock *sk, int level,
519 int optname, char __user *optval,
520 int __user *option);
521 int (*sendmsg)(struct kiocb *iocb, struct sock *sk,
522 struct msghdr *msg, size_t len);
523 int (*recvmsg)(struct kiocb *iocb, struct sock *sk,
524 struct msghdr *msg,
525 size_t len, int noblock, int flags,
526 int *addr_len);
527 int (*sendpage)(struct sock *sk, struct page *page,
528 int offset, size_t size, int flags);
529 int (*bind)(struct sock *sk,
530 struct sockaddr *uaddr, int addr_len);
531
532 int (*backlog_rcv) (struct sock *sk,
533 struct sk_buff *skb);
534
535 /* Keeping track of sk's, looking them up, and port selection methods. */
536 void (*hash)(struct sock *sk);
537 void (*unhash)(struct sock *sk);
538 int (*get_port)(struct sock *sk, unsigned short snum);
539
540 /* Memory pressure */
541 void (*enter_memory_pressure)(void);
542 atomic_t *memory_allocated; /* Current allocated memory. */
543 atomic_t *sockets_allocated; /* Current number of sockets. */
544 /*
545 * Pressure flag: try to collapse.
546 * Technical note: it is used by multiple contexts non atomically.
547 * All the sk_stream_mem_schedule() is of this nature: accounting
548 * is strict, actions are advisory and have some latency.
549 */
550 int *memory_pressure;
551 int *sysctl_mem;
552 int *sysctl_wmem;
553 int *sysctl_rmem;
554 int max_header;
555
556 kmem_cache_t *slab;
557 int slab_obj_size;
558
559 struct module *owner;
560
561 char name[32];
562
563 struct {
564 int inuse;
565 u8 __pad[SMP_CACHE_BYTES - sizeof(int)];
566 } stats[NR_CPUS];
567 };
568
569 extern int sk_alloc_slab(struct proto *prot, char *name);
570 extern void sk_free_slab(struct proto *prot);
571
572 static inline void sk_alloc_slab_error(struct proto *proto)
573 {
574 printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n", proto->name);
575 }
576
577 static __inline__ void sk_set_owner(struct sock *sk, struct module *owner)
578 {
579 /*
580 * One should use sk_set_owner just once, after struct sock creation,
581 * be it shortly after sk_alloc or after a function that returns a new
582 * struct sock (and that down the call chain called sk_alloc), e.g. the
583 * IPv4 and IPv6 modules share tcp_create_openreq_child, so if
584 * tcp_create_openreq_child called sk_set_owner IPv6 would have to
585 * change the ownership of this struct sock, with one not needed
586 * transient sk_set_owner call.
587 */
588 BUG_ON(sk->sk_owner != NULL);
589
590 sk->sk_owner = owner;
591 __module_get(owner);
592 }
593
594 /* Called with local bh disabled */
595 static __inline__ void sock_prot_inc_use(struct proto *prot)
596 {
597 prot->stats[smp_processor_id()].inuse++;
598 }
599
600 static __inline__ void sock_prot_dec_use(struct proto *prot)
601 {
602 prot->stats[smp_processor_id()].inuse--;
603 }
604
605 /* About 10 seconds */
606 #define SOCK_DESTROY_TIME (10*HZ)
607
608 /* Sockets 0-1023 can't be bound to unless you are superuser */
609 #define PROT_SOCK 1024
610
611 #define SHUTDOWN_MASK 3
612 #define RCV_SHUTDOWN 1
613 #define SEND_SHUTDOWN 2
614
615 #define SOCK_SNDBUF_LOCK 1
616 #define SOCK_RCVBUF_LOCK 2
617 #define SOCK_BINDADDR_LOCK 4
618 #define SOCK_BINDPORT_LOCK 8
619
620 /* sock_iocb: used to kick off async processing of socket ios */
621 struct sock_iocb {
622 struct list_head list;
623
624 int flags;
625 int size;
626 struct socket *sock;
627 struct sock *sk;
628 struct scm_cookie *scm;
629 struct msghdr *msg, async_msg;
630 struct iovec async_iov;
631 struct kiocb *kiocb;
632 };
633
634 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
635 {
636 return (struct sock_iocb *)iocb->private;
637 }
638
639 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
640 {
641 return si->kiocb;
642 }
643
644 struct socket_alloc {
645 struct socket socket;
646 struct inode vfs_inode;
647 };
648
649 static inline struct socket *SOCKET_I(struct inode *inode)
650 {
651 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
652 }
653
654 static inline struct inode *SOCK_INODE(struct socket *socket)
655 {
656 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
657 }
658
659 extern void __sk_stream_mem_reclaim(struct sock *sk);
660 extern int sk_stream_mem_schedule(struct sock *sk, int size, int kind);
661
662 #define SK_STREAM_MEM_QUANTUM ((int)PAGE_SIZE)
663
664 static inline int sk_stream_pages(int amt)
665 {
666 return (amt + SK_STREAM_MEM_QUANTUM - 1) / SK_STREAM_MEM_QUANTUM;
667 }
668
669 static inline void sk_stream_mem_reclaim(struct sock *sk)
670 {
671 if (sk->sk_forward_alloc >= SK_STREAM_MEM_QUANTUM)
672 __sk_stream_mem_reclaim(sk);
673 }
674
675 static inline void sk_stream_writequeue_purge(struct sock *sk)
676 {
677 struct sk_buff *skb;
678
679 while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
680 sk_stream_free_skb(sk, skb);
681 sk_stream_mem_reclaim(sk);
682 }
683
684 static inline int sk_stream_rmem_schedule(struct sock *sk, struct sk_buff *skb)
685 {
686 return (int)skb->truesize <= sk->sk_forward_alloc ||
687 sk_stream_mem_schedule(sk, skb->truesize, 1);
688 }
689
690 /* Used by processes to "lock" a socket state, so that
691 * interrupts and bottom half handlers won't change it
692 * from under us. It essentially blocks any incoming
693 * packets, so that we won't get any new data or any
694 * packets that change the state of the socket.
695 *
696 * While locked, BH processing will add new packets to
697 * the backlog queue. This queue is processed by the
698 * owner of the socket lock right before it is released.
699 *
700 * Since ~2.3.5 it is also exclusive sleep lock serializing
701 * accesses from user process context.
702 */
703 #define sock_owned_by_user(sk) ((sk)->sk_lock.owner)
704
705 extern void FASTCALL(lock_sock(struct sock *sk));
706 extern void FASTCALL(release_sock(struct sock *sk));
707
708 /* BH context may only use the following locking interface. */
709 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
710 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
711
712 extern struct sock * sk_alloc(int family, int priority, int zero_it,
713 kmem_cache_t *slab);
714 extern void sk_free(struct sock *sk);
715
716 extern struct sk_buff *sock_wmalloc(struct sock *sk,
717 unsigned long size, int force,
718 int priority);
719 extern struct sk_buff *sock_rmalloc(struct sock *sk,
720 unsigned long size, int force,
721 int priority);
722 extern void sock_wfree(struct sk_buff *skb);
723 extern void sock_rfree(struct sk_buff *skb);
724
725 extern int sock_setsockopt(struct socket *sock, int level,
726 int op, char __user *optval,
727 int optlen);
728
729 extern int sock_getsockopt(struct socket *sock, int level,
730 int op, char __user *optval,
731 int __user *optlen);
732 extern struct sk_buff *sock_alloc_send_skb(struct sock *sk,
733 unsigned long size,
734 int noblock,
735 int *errcode);
736 extern void *sock_kmalloc(struct sock *sk, int size, int priority);
737 extern void sock_kfree_s(struct sock *sk, void *mem, int size);
738 extern void sk_send_sigurg(struct sock *sk);
739
740 /*
741 * Functions to fill in entries in struct proto_ops when a protocol
742 * does not implement a particular function.
743 */
744 extern int sock_no_bind(struct socket *,
745 struct sockaddr *, int);
746 extern int sock_no_connect(struct socket *,
747 struct sockaddr *, int, int);
748 extern int sock_no_socketpair(struct socket *,
749 struct socket *);
750 extern int sock_no_accept(struct socket *,
751 struct socket *, int);
752 extern int sock_no_getname(struct socket *,
753 struct sockaddr *, int *, int);
754 extern unsigned int sock_no_poll(struct file *, struct socket *,
755 struct poll_table_struct *);
756 extern int sock_no_ioctl(struct socket *, unsigned int,
757 unsigned long);
758 extern int sock_no_listen(struct socket *, int);
759 extern int sock_no_shutdown(struct socket *, int);
760 extern int sock_no_getsockopt(struct socket *, int , int,
761 char __user *, int __user *);
762 extern int sock_no_setsockopt(struct socket *, int, int,
763 char __user *, int);
764 extern int sock_no_sendmsg(struct kiocb *, struct socket *,
765 struct msghdr *, size_t);
766 extern int sock_no_recvmsg(struct kiocb *, struct socket *,
767 struct msghdr *, size_t, int);
768 extern int sock_no_mmap(struct file *file,
769 struct socket *sock,
770 struct vm_area_struct *vma);
771 extern ssize_t sock_no_sendpage(struct socket *sock,
772 struct page *page,
773 int offset, size_t size,
774 int flags);
775
776 /*
777 * Functions to fill in entries in struct proto_ops when a protocol
778 * uses the inet style.
779 */
780 extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
781 char __user *optval, int __user *optlen);
782 extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
783 struct msghdr *msg, size_t size, int flags);
784 extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
785 char __user *optval, int optlen);
786
787 extern void sk_common_release(struct sock *sk);
788
789 /*
790 * Default socket callbacks and setup code
791 */
792
793 /* Initialise core socket variables */
794 extern void sock_init_data(struct socket *sock, struct sock *sk);
795
796 /**
797 * sk_filter - run a packet through a socket filter
798 * @sk: sock associated with &sk_buff
799 * @skb: buffer to filter
800 * @needlock: set to 1 if the sock is not locked by caller.
801 *
802 * Run the filter code and then cut skb->data to correct size returned by
803 * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller
804 * than pkt_len we keep whole skb->data. This is the socket level
805 * wrapper to sk_run_filter. It returns 0 if the packet should
806 * be accepted or -EPERM if the packet should be tossed.
807 *
808 */
809
810 static inline int sk_filter(struct sock *sk, struct sk_buff *skb, int needlock)
811 {
812 int err;
813
814 err = security_sock_rcv_skb(sk, skb);
815 if (err)
816 return err;
817
818 if (sk->sk_filter) {
819 struct sk_filter *filter;
820
821 if (needlock)
822 bh_lock_sock(sk);
823
824 filter = sk->sk_filter;
825 if (filter) {
826 int pkt_len = sk_run_filter(skb, filter->insns,
827 filter->len);
828 if (!pkt_len)
829 err = -EPERM;
830 else
831 skb_trim(skb, pkt_len);
832 }
833
834 if (needlock)
835 bh_unlock_sock(sk);
836 }
837 return err;
838 }
839
840 /**
841 * sk_filter_release: Release a socket filter
842 * @sk: socket
843 * @fp: filter to remove
844 *
845 * Remove a filter from a socket and release its resources.
846 */
847
848 static inline void sk_filter_release(struct sock *sk, struct sk_filter *fp)
849 {
850 unsigned int size = sk_filter_len(fp);
851
852 atomic_sub(size, &sk->sk_omem_alloc);
853
854 if (atomic_dec_and_test(&fp->refcnt))
855 kfree(fp);
856 }
857
858 static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
859 {
860 atomic_inc(&fp->refcnt);
861 atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
862 }
863
864 /*
865 * Socket reference counting postulates.
866 *
867 * * Each user of socket SHOULD hold a reference count.
868 * * Each access point to socket (an hash table bucket, reference from a list,
869 * running timer, skb in flight MUST hold a reference count.
870 * * When reference count hits 0, it means it will never increase back.
871 * * When reference count hits 0, it means that no references from
872 * outside exist to this socket and current process on current CPU
873 * is last user and may/should destroy this socket.
874 * * sk_free is called from any context: process, BH, IRQ. When
875 * it is called, socket has no references from outside -> sk_free
876 * may release descendant resources allocated by the socket, but
877 * to the time when it is called, socket is NOT referenced by any
878 * hash tables, lists etc.
879 * * Packets, delivered from outside (from network or from another process)
880 * and enqueued on receive/error queues SHOULD NOT grab reference count,
881 * when they sit in queue. Otherwise, packets will leak to hole, when
882 * socket is looked up by one cpu and unhasing is made by another CPU.
883 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
884 * (leak to backlog). Packet socket does all the processing inside
885 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
886 * use separate SMP lock, so that they are prone too.
887 */
888
889 /* Ungrab socket and destroy it, if it was the last reference. */
890 static inline void sock_put(struct sock *sk)
891 {
892 if (atomic_dec_and_test(&sk->sk_refcnt))
893 sk_free(sk);
894 }
895
896 /* Detach socket from process context.
897 * Announce socket dead, detach it from wait queue and inode.
898 * Note that parent inode held reference count on this struct sock,
899 * we do not release it in this function, because protocol
900 * probably wants some additional cleanups or even continuing
901 * to work with this socket (TCP).
902 */
903 static inline void sock_orphan(struct sock *sk)
904 {
905 write_lock_bh(&sk->sk_callback_lock);
906 sock_set_flag(sk, SOCK_DEAD);
907 sk->sk_socket = NULL;
908 sk->sk_sleep = NULL;
909 write_unlock_bh(&sk->sk_callback_lock);
910 }
911
912 static inline void sock_graft(struct sock *sk, struct socket *parent)
913 {
914 write_lock_bh(&sk->sk_callback_lock);
915 sk->sk_sleep = &parent->wait;
916 parent->sk = sk;
917 sk->sk_socket = parent;
918 write_unlock_bh(&sk->sk_callback_lock);
919 }
920
921 extern int sock_i_uid(struct sock *sk);
922 extern unsigned long sock_i_ino(struct sock *sk);
923
924 static inline struct dst_entry *
925 __sk_dst_get(struct sock *sk)
926 {
927 return sk->sk_dst_cache;
928 }
929
930 static inline struct dst_entry *
931 sk_dst_get(struct sock *sk)
932 {
933 struct dst_entry *dst;
934
935 read_lock(&sk->sk_dst_lock);
936 dst = sk->sk_dst_cache;
937 if (dst)
938 dst_hold(dst);
939 read_unlock(&sk->sk_dst_lock);
940 return dst;
941 }
942
943 static inline void
944 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
945 {
946 struct dst_entry *old_dst;
947
948 old_dst = sk->sk_dst_cache;
949 sk->sk_dst_cache = dst;
950 dst_release(old_dst);
951 }
952
953 static inline void
954 sk_dst_set(struct sock *sk, struct dst_entry *dst)
955 {
956 write_lock(&sk->sk_dst_lock);
957 __sk_dst_set(sk, dst);
958 write_unlock(&sk->sk_dst_lock);
959 }
960
961 static inline void
962 __sk_dst_reset(struct sock *sk)
963 {
964 struct dst_entry *old_dst;
965
966 old_dst = sk->sk_dst_cache;
967 sk->sk_dst_cache = NULL;
968 dst_release(old_dst);
969 }
970
971 static inline void
972 sk_dst_reset(struct sock *sk)
973 {
974 write_lock(&sk->sk_dst_lock);
975 __sk_dst_reset(sk);
976 write_unlock(&sk->sk_dst_lock);
977 }
978
979 static inline struct dst_entry *
980 __sk_dst_check(struct sock *sk, u32 cookie)
981 {
982 struct dst_entry *dst = sk->sk_dst_cache;
983
984 if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
985 sk->sk_dst_cache = NULL;
986 return NULL;
987 }
988
989 return dst;
990 }
991
992 static inline struct dst_entry *
993 sk_dst_check(struct sock *sk, u32 cookie)
994 {
995 struct dst_entry *dst = sk_dst_get(sk);
996
997 if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
998 sk_dst_reset(sk);
999 return NULL;
1000 }
1001
1002 return dst;
1003 }
1004
1005 static inline void sk_charge_skb(struct sock *sk, struct sk_buff *skb)
1006 {
1007 sk->sk_wmem_queued += skb->truesize;
1008 sk->sk_forward_alloc -= skb->truesize;
1009 }
1010
1011 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1012 struct sk_buff *skb, struct page *page,
1013 int off, int copy)
1014 {
1015 if (skb->ip_summed == CHECKSUM_NONE) {
1016 int err = 0;
1017 unsigned int csum = csum_and_copy_from_user(from,
1018 page_address(page) + off,
1019 copy, 0, &err);
1020 if (err)
1021 return err;
1022 skb->csum = csum_block_add(skb->csum, csum, skb->len);
1023 } else if (copy_from_user(page_address(page) + off, from, copy))
1024 return -EFAULT;
1025
1026 skb->len += copy;
1027 skb->data_len += copy;
1028 skb->truesize += copy;
1029 sk->sk_wmem_queued += copy;
1030 sk->sk_forward_alloc -= copy;
1031 return 0;
1032 }
1033
1034 /*
1035 * Queue a received datagram if it will fit. Stream and sequenced
1036 * protocols can't normally use this as they need to fit buffers in
1037 * and play with them.
1038 *
1039 * Inlined as it's very short and called for pretty much every
1040 * packet ever received.
1041 */
1042
1043 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1044 {
1045 sock_hold(sk);
1046 skb->sk = sk;
1047 skb->destructor = sock_wfree;
1048 atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1049 }
1050
1051 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1052 {
1053 skb->sk = sk;
1054 skb->destructor = sock_rfree;
1055 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1056 }
1057
1058 extern void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1059 unsigned long expires);
1060
1061 extern void sk_stop_timer(struct sock *sk, struct timer_list* timer);
1062
1063 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
1064 {
1065 int err = 0;
1066 int skb_len;
1067
1068 /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
1069 number of warnings when compiling with -W --ANK
1070 */
1071 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
1072 (unsigned)sk->sk_rcvbuf) {
1073 err = -ENOMEM;
1074 goto out;
1075 }
1076
1077 /* It would be deadlock, if sock_queue_rcv_skb is used
1078 with socket lock! We assume that users of this
1079 function are lock free.
1080 */
1081 err = sk_filter(sk, skb, 1);
1082 if (err)
1083 goto out;
1084
1085 skb->dev = NULL;
1086 skb_set_owner_r(skb, sk);
1087
1088 /* Cache the SKB length before we tack it onto the receive
1089 * queue. Once it is added it no longer belongs to us and
1090 * may be freed by other threads of control pulling packets
1091 * from the queue.
1092 */
1093 skb_len = skb->len;
1094
1095 skb_queue_tail(&sk->sk_receive_queue, skb);
1096
1097 if (!sock_flag(sk, SOCK_DEAD))
1098 sk->sk_data_ready(sk, skb_len);
1099 out:
1100 return err;
1101 }
1102
1103 static inline int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
1104 {
1105 /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
1106 number of warnings when compiling with -W --ANK
1107 */
1108 if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
1109 (unsigned)sk->sk_rcvbuf)
1110 return -ENOMEM;
1111 skb_set_owner_r(skb, sk);
1112 skb_queue_tail(&sk->sk_error_queue, skb);
1113 if (!sock_flag(sk, SOCK_DEAD))
1114 sk->sk_data_ready(sk, skb->len);
1115 return 0;
1116 }
1117
1118 /*
1119 * Recover an error report and clear atomically
1120 */
1121
1122 static inline int sock_error(struct sock *sk)
1123 {
1124 int err = xchg(&sk->sk_err, 0);
1125 return -err;
1126 }
1127
1128 static inline unsigned long sock_wspace(struct sock *sk)
1129 {
1130 int amt = 0;
1131
1132 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1133 amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1134 if (amt < 0)
1135 amt = 0;
1136 }
1137 return amt;
1138 }
1139
1140 static inline void sk_wake_async(struct sock *sk, int how, int band)
1141 {
1142 if (sk->sk_socket && sk->sk_socket->fasync_list)
1143 sock_wake_async(sk->sk_socket, how, band);
1144 }
1145
1146 #define SOCK_MIN_SNDBUF 2048
1147 #define SOCK_MIN_RCVBUF 256
1148
1149 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1150 {
1151 if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1152 sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued / 2);
1153 sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1154 }
1155 }
1156
1157 static inline struct sk_buff *sk_stream_alloc_pskb(struct sock *sk,
1158 int size, int mem, int gfp)
1159 {
1160 struct sk_buff *skb = alloc_skb(size + sk->sk_prot->max_header, gfp);
1161
1162 if (skb) {
1163 skb->truesize += mem;
1164 if (sk->sk_forward_alloc >= (int)skb->truesize ||
1165 sk_stream_mem_schedule(sk, skb->truesize, 0)) {
1166 skb_reserve(skb, sk->sk_prot->max_header);
1167 return skb;
1168 }
1169 __kfree_skb(skb);
1170 } else {
1171 sk->sk_prot->enter_memory_pressure();
1172 sk_stream_moderate_sndbuf(sk);
1173 }
1174 return NULL;
1175 }
1176
1177 static inline struct sk_buff *sk_stream_alloc_skb(struct sock *sk,
1178 int size, int gfp)
1179 {
1180 return sk_stream_alloc_pskb(sk, size, 0, gfp);
1181 }
1182
1183 static inline struct page *sk_stream_alloc_page(struct sock *sk)
1184 {
1185 struct page *page = NULL;
1186
1187 if (sk->sk_forward_alloc >= (int)PAGE_SIZE ||
1188 sk_stream_mem_schedule(sk, PAGE_SIZE, 0))
1189 page = alloc_pages(sk->sk_allocation, 0);
1190 else {
1191 sk->sk_prot->enter_memory_pressure();
1192 sk_stream_moderate_sndbuf(sk);
1193 }
1194 return page;
1195 }
1196
1197 #define sk_stream_for_retrans_queue(skb, sk) \
1198 for (skb = (sk)->sk_write_queue.next; \
1199 (skb != (sk)->sk_send_head) && \
1200 (skb != (struct sk_buff *)&(sk)->sk_write_queue); \
1201 skb = skb->next)
1202
1203 /*
1204 * Default write policy as shown to user space via poll/select/SIGIO
1205 */
1206 static inline int sock_writeable(const struct sock *sk)
1207 {
1208 return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf / 2);
1209 }
1210
1211 static inline int gfp_any(void)
1212 {
1213 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
1214 }
1215
1216 static inline long sock_rcvtimeo(const struct sock *sk, int noblock)
1217 {
1218 return noblock ? 0 : sk->sk_rcvtimeo;
1219 }
1220
1221 static inline long sock_sndtimeo(const struct sock *sk, int noblock)
1222 {
1223 return noblock ? 0 : sk->sk_sndtimeo;
1224 }
1225
1226 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
1227 {
1228 return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
1229 }
1230
1231 /* Alas, with timeout socket operations are not restartable.
1232 * Compare this to poll().
1233 */
1234 static inline int sock_intr_errno(long timeo)
1235 {
1236 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1237 }
1238
1239 static __inline__ void
1240 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
1241 {
1242 struct timeval *stamp = &skb->stamp;
1243 if (sk->sk_rcvtstamp) {
1244 /* Race occurred between timestamp enabling and packet
1245 receiving. Fill in the current time for now. */
1246 if (stamp->tv_sec == 0)
1247 do_gettimeofday(stamp);
1248 put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP, sizeof(struct timeval),
1249 stamp);
1250 } else
1251 sk->sk_stamp = *stamp;
1252 }
1253
1254 /**
1255 * sk_eat_skb - Release a skb if it is no longer needed
1256 * @sk - socket to eat this skb from
1257 * @skb - socket buffer to eat
1258 *
1259 * This routine must be called with interrupts disabled or with the socket
1260 * locked so that the sk_buff queue operation is ok.
1261 */
1262 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
1263 {
1264 __skb_unlink(skb, &sk->sk_receive_queue);
1265 __kfree_skb(skb);
1266 }
1267
1268 extern void sock_enable_timestamp(struct sock *sk);
1269 extern int sock_get_timestamp(struct sock *, struct timeval __user *);
1270
1271 /*
1272 * Enable debug/info messages
1273 */
1274
1275 #if 0
1276 #define NETDEBUG(x) do { } while (0)
1277 #define LIMIT_NETDEBUG(x) do {} while(0)
1278 #else
1279 #define NETDEBUG(x) do { x; } while (0)
1280 #define LIMIT_NETDEBUG(x) do { if (net_ratelimit()) { x; } } while(0)
1281 #endif
1282
1283 /*
1284 * Macros for sleeping on a socket. Use them like this:
1285 *
1286 * SOCK_SLEEP_PRE(sk)
1287 * if (condition)
1288 * schedule();
1289 * SOCK_SLEEP_POST(sk)
1290 *
1291 * N.B. These are now obsolete and were, afaik, only ever used in DECnet
1292 * and when the last use of them in DECnet has gone, I'm intending to
1293 * remove them.
1294 */
1295
1296 #define SOCK_SLEEP_PRE(sk) { struct task_struct *tsk = current; \
1297 DECLARE_WAITQUEUE(wait, tsk); \
1298 tsk->state = TASK_INTERRUPTIBLE; \
1299 add_wait_queue((sk)->sk_sleep, &wait); \
1300 release_sock(sk);
1301
1302 #define SOCK_SLEEP_POST(sk) tsk->state = TASK_RUNNING; \
1303 remove_wait_queue((sk)->sk_sleep, &wait); \
1304 lock_sock(sk); \
1305 }
1306
1307 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
1308 {
1309 if (valbool)
1310 sock_set_flag(sk, bit);
1311 else
1312 sock_reset_flag(sk, bit);
1313 }
1314
1315 extern __u32 sysctl_wmem_max;
1316 extern __u32 sysctl_rmem_max;
1317
1318 #ifdef CONFIG_NET
1319 int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg);
1320 #else
1321 static inline int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
1322 {
1323 return -ENODEV;
1324 }
1325 #endif
1326
1327 #endif /* _SOCK_H */
1328
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