xref: /linux/include/net/sock.h (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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/list.h>
44 #include <linux/timer.h>
45 #include <linux/cache.h>
46 #include <linux/module.h>
47 #include <linux/lockdep.h>
48 #include <linux/netdevice.h>
49 #include <linux/skbuff.h>	/* struct sk_buff */
50 #include <linux/mm.h>
51 #include <linux/security.h>
52 
53 #include <linux/filter.h>
54 
55 #include <asm/atomic.h>
56 #include <net/dst.h>
57 #include <net/checksum.h>
58 
59 /*
60  * This structure really needs to be cleaned up.
61  * Most of it is for TCP, and not used by any of
62  * the other protocols.
63  */
64 
65 /* Define this to get the SOCK_DBG debugging facility. */
66 #define SOCK_DEBUGGING
67 #ifdef SOCK_DEBUGGING
68 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
69 					printk(KERN_DEBUG msg); } while (0)
70 #else
71 #define SOCK_DEBUG(sk, msg...) do { } while (0)
72 #endif
73 
74 /* This is the per-socket lock.  The spinlock provides a synchronization
75  * between user contexts and software interrupt processing, whereas the
76  * mini-semaphore synchronizes multiple users amongst themselves.
77  */
78 struct sock_iocb;
79 typedef struct {
80 	spinlock_t		slock;
81 	struct sock_iocb	*owner;
82 	wait_queue_head_t	wq;
83 	/*
84 	 * We express the mutex-alike socket_lock semantics
85 	 * to the lock validator by explicitly managing
86 	 * the slock as a lock variant (in addition to
87 	 * the slock itself):
88 	 */
89 #ifdef CONFIG_DEBUG_LOCK_ALLOC
90 	struct lockdep_map dep_map;
91 #endif
92 } socket_lock_t;
93 
94 struct sock;
95 struct proto;
96 
97 /**
98  *	struct sock_common - minimal network layer representation of sockets
99  *	@skc_family: network address family
100  *	@skc_state: Connection state
101  *	@skc_reuse: %SO_REUSEADDR setting
102  *	@skc_bound_dev_if: bound device index if != 0
103  *	@skc_node: main hash linkage for various protocol lookup tables
104  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
105  *	@skc_refcnt: reference count
106  *	@skc_hash: hash value used with various protocol lookup tables
107  *	@skc_prot: protocol handlers inside a network family
108  *
109  *	This is the minimal network layer representation of sockets, the header
110  *	for struct sock and struct inet_timewait_sock.
111  */
112 struct sock_common {
113 	unsigned short		skc_family;
114 	volatile unsigned char	skc_state;
115 	unsigned char		skc_reuse;
116 	int			skc_bound_dev_if;
117 	struct hlist_node	skc_node;
118 	struct hlist_node	skc_bind_node;
119 	atomic_t		skc_refcnt;
120 	unsigned int		skc_hash;
121 	struct proto		*skc_prot;
122 };
123 
124 /**
125   *	struct sock - network layer representation of sockets
126   *	@__sk_common: shared layout with inet_timewait_sock
127   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
128   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
129   *	@sk_lock:	synchronizer
130   *	@sk_rcvbuf: size of receive buffer in bytes
131   *	@sk_sleep: sock wait queue
132   *	@sk_dst_cache: destination cache
133   *	@sk_dst_lock: destination cache lock
134   *	@sk_policy: flow policy
135   *	@sk_rmem_alloc: receive queue bytes committed
136   *	@sk_receive_queue: incoming packets
137   *	@sk_wmem_alloc: transmit queue bytes committed
138   *	@sk_write_queue: Packet sending queue
139   *	@sk_async_wait_queue: DMA copied packets
140   *	@sk_omem_alloc: "o" is "option" or "other"
141   *	@sk_wmem_queued: persistent queue size
142   *	@sk_forward_alloc: space allocated forward
143   *	@sk_allocation: allocation mode
144   *	@sk_sndbuf: size of send buffer in bytes
145   *	@sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, %SO_OOBINLINE settings
146   *	@sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
147   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
148   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
149   *	@sk_lingertime: %SO_LINGER l_linger setting
150   *	@sk_backlog: always used with the per-socket spinlock held
151   *	@sk_callback_lock: used with the callbacks in the end of this struct
152   *	@sk_error_queue: rarely used
153   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, IPV6_ADDRFORM for instance)
154   *	@sk_err: last error
155   *	@sk_err_soft: errors that don't cause failure but are the cause of a persistent failure not just 'timed out'
156   *	@sk_ack_backlog: current listen backlog
157   *	@sk_max_ack_backlog: listen backlog set in listen()
158   *	@sk_priority: %SO_PRIORITY setting
159   *	@sk_type: socket type (%SOCK_STREAM, etc)
160   *	@sk_protocol: which protocol this socket belongs in this network family
161   *	@sk_peercred: %SO_PEERCRED setting
162   *	@sk_rcvlowat: %SO_RCVLOWAT setting
163   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
164   *	@sk_sndtimeo: %SO_SNDTIMEO setting
165   *	@sk_filter: socket filtering instructions
166   *	@sk_protinfo: private area, net family specific, when not using slab
167   *	@sk_timer: sock cleanup timer
168   *	@sk_stamp: time stamp of last packet received
169   *	@sk_socket: Identd and reporting IO signals
170   *	@sk_user_data: RPC layer private data
171   *	@sk_sndmsg_page: cached page for sendmsg
172   *	@sk_sndmsg_off: cached offset for sendmsg
173   *	@sk_send_head: front of stuff to transmit
174   *	@sk_security: used by security modules
175   *	@sk_write_pending: a write to stream socket waits to start
176   *	@sk_state_change: callback to indicate change in the state of the sock
177   *	@sk_data_ready: callback to indicate there is data to be processed
178   *	@sk_write_space: callback to indicate there is bf sending space available
179   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
180   *	@sk_backlog_rcv: callback to process the backlog
181   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
182  */
183 struct sock {
184 	/*
185 	 * Now struct inet_timewait_sock also uses sock_common, so please just
186 	 * don't add nothing before this first member (__sk_common) --acme
187 	 */
188 	struct sock_common	__sk_common;
189 #define sk_family		__sk_common.skc_family
190 #define sk_state		__sk_common.skc_state
191 #define sk_reuse		__sk_common.skc_reuse
192 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
193 #define sk_node			__sk_common.skc_node
194 #define sk_bind_node		__sk_common.skc_bind_node
195 #define sk_refcnt		__sk_common.skc_refcnt
196 #define sk_hash			__sk_common.skc_hash
197 #define sk_prot			__sk_common.skc_prot
198 	unsigned char		sk_shutdown : 2,
199 				sk_no_check : 2,
200 				sk_userlocks : 4;
201 	unsigned char		sk_protocol;
202 	unsigned short		sk_type;
203 	int			sk_rcvbuf;
204 	socket_lock_t		sk_lock;
205 	wait_queue_head_t	*sk_sleep;
206 	struct dst_entry	*sk_dst_cache;
207 	struct xfrm_policy	*sk_policy[2];
208 	rwlock_t		sk_dst_lock;
209 	atomic_t		sk_rmem_alloc;
210 	atomic_t		sk_wmem_alloc;
211 	atomic_t		sk_omem_alloc;
212 	struct sk_buff_head	sk_receive_queue;
213 	struct sk_buff_head	sk_write_queue;
214 	struct sk_buff_head	sk_async_wait_queue;
215 	int			sk_wmem_queued;
216 	int			sk_forward_alloc;
217 	gfp_t			sk_allocation;
218 	int			sk_sndbuf;
219 	int			sk_route_caps;
220 	int			sk_gso_type;
221 	int			sk_rcvlowat;
222 	unsigned long 		sk_flags;
223 	unsigned long	        sk_lingertime;
224 	/*
225 	 * The backlog queue is special, it is always used with
226 	 * the per-socket spinlock held and requires low latency
227 	 * access. Therefore we special case it's implementation.
228 	 */
229 	struct {
230 		struct sk_buff *head;
231 		struct sk_buff *tail;
232 	} sk_backlog;
233 	struct sk_buff_head	sk_error_queue;
234 	struct proto		*sk_prot_creator;
235 	rwlock_t		sk_callback_lock;
236 	int			sk_err,
237 				sk_err_soft;
238 	unsigned short		sk_ack_backlog;
239 	unsigned short		sk_max_ack_backlog;
240 	__u32			sk_priority;
241 	struct ucred		sk_peercred;
242 	long			sk_rcvtimeo;
243 	long			sk_sndtimeo;
244 	struct sk_filter      	*sk_filter;
245 	void			*sk_protinfo;
246 	struct timer_list	sk_timer;
247 	struct timeval		sk_stamp;
248 	struct socket		*sk_socket;
249 	void			*sk_user_data;
250 	struct page		*sk_sndmsg_page;
251 	struct sk_buff		*sk_send_head;
252 	__u32			sk_sndmsg_off;
253 	int			sk_write_pending;
254 	void			*sk_security;
255 	void			(*sk_state_change)(struct sock *sk);
256 	void			(*sk_data_ready)(struct sock *sk, int bytes);
257 	void			(*sk_write_space)(struct sock *sk);
258 	void			(*sk_error_report)(struct sock *sk);
259   	int			(*sk_backlog_rcv)(struct sock *sk,
260 						  struct sk_buff *skb);
261 	void                    (*sk_destruct)(struct sock *sk);
262 };
263 
264 /*
265  * Hashed lists helper routines
266  */
267 static inline struct sock *__sk_head(const struct hlist_head *head)
268 {
269 	return hlist_entry(head->first, struct sock, sk_node);
270 }
271 
272 static inline struct sock *sk_head(const struct hlist_head *head)
273 {
274 	return hlist_empty(head) ? NULL : __sk_head(head);
275 }
276 
277 static inline struct sock *sk_next(const struct sock *sk)
278 {
279 	return sk->sk_node.next ?
280 		hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
281 }
282 
283 static inline int sk_unhashed(const struct sock *sk)
284 {
285 	return hlist_unhashed(&sk->sk_node);
286 }
287 
288 static inline int sk_hashed(const struct sock *sk)
289 {
290 	return !sk_unhashed(sk);
291 }
292 
293 static __inline__ void sk_node_init(struct hlist_node *node)
294 {
295 	node->pprev = NULL;
296 }
297 
298 static __inline__ void __sk_del_node(struct sock *sk)
299 {
300 	__hlist_del(&sk->sk_node);
301 }
302 
303 static __inline__ int __sk_del_node_init(struct sock *sk)
304 {
305 	if (sk_hashed(sk)) {
306 		__sk_del_node(sk);
307 		sk_node_init(&sk->sk_node);
308 		return 1;
309 	}
310 	return 0;
311 }
312 
313 /* Grab socket reference count. This operation is valid only
314    when sk is ALREADY grabbed f.e. it is found in hash table
315    or a list and the lookup is made under lock preventing hash table
316    modifications.
317  */
318 
319 static inline void sock_hold(struct sock *sk)
320 {
321 	atomic_inc(&sk->sk_refcnt);
322 }
323 
324 /* Ungrab socket in the context, which assumes that socket refcnt
325    cannot hit zero, f.e. it is true in context of any socketcall.
326  */
327 static inline void __sock_put(struct sock *sk)
328 {
329 	atomic_dec(&sk->sk_refcnt);
330 }
331 
332 static __inline__ int sk_del_node_init(struct sock *sk)
333 {
334 	int rc = __sk_del_node_init(sk);
335 
336 	if (rc) {
337 		/* paranoid for a while -acme */
338 		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
339 		__sock_put(sk);
340 	}
341 	return rc;
342 }
343 
344 static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list)
345 {
346 	hlist_add_head(&sk->sk_node, list);
347 }
348 
349 static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list)
350 {
351 	sock_hold(sk);
352 	__sk_add_node(sk, list);
353 }
354 
355 static __inline__ void __sk_del_bind_node(struct sock *sk)
356 {
357 	__hlist_del(&sk->sk_bind_node);
358 }
359 
360 static __inline__ void sk_add_bind_node(struct sock *sk,
361 					struct hlist_head *list)
362 {
363 	hlist_add_head(&sk->sk_bind_node, list);
364 }
365 
366 #define sk_for_each(__sk, node, list) \
367 	hlist_for_each_entry(__sk, node, list, sk_node)
368 #define sk_for_each_from(__sk, node) \
369 	if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
370 		hlist_for_each_entry_from(__sk, node, sk_node)
371 #define sk_for_each_continue(__sk, node) \
372 	if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
373 		hlist_for_each_entry_continue(__sk, node, sk_node)
374 #define sk_for_each_safe(__sk, node, tmp, list) \
375 	hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
376 #define sk_for_each_bound(__sk, node, list) \
377 	hlist_for_each_entry(__sk, node, list, sk_bind_node)
378 
379 /* Sock flags */
380 enum sock_flags {
381 	SOCK_DEAD,
382 	SOCK_DONE,
383 	SOCK_URGINLINE,
384 	SOCK_KEEPOPEN,
385 	SOCK_LINGER,
386 	SOCK_DESTROY,
387 	SOCK_BROADCAST,
388 	SOCK_TIMESTAMP,
389 	SOCK_ZAPPED,
390 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
391 	SOCK_DBG, /* %SO_DEBUG setting */
392 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
393 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
394 	SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
395 };
396 
397 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
398 {
399 	nsk->sk_flags = osk->sk_flags;
400 }
401 
402 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
403 {
404 	__set_bit(flag, &sk->sk_flags);
405 }
406 
407 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
408 {
409 	__clear_bit(flag, &sk->sk_flags);
410 }
411 
412 static inline int sock_flag(struct sock *sk, enum sock_flags flag)
413 {
414 	return test_bit(flag, &sk->sk_flags);
415 }
416 
417 static inline void sk_acceptq_removed(struct sock *sk)
418 {
419 	sk->sk_ack_backlog--;
420 }
421 
422 static inline void sk_acceptq_added(struct sock *sk)
423 {
424 	sk->sk_ack_backlog++;
425 }
426 
427 static inline int sk_acceptq_is_full(struct sock *sk)
428 {
429 	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
430 }
431 
432 /*
433  * Compute minimal free write space needed to queue new packets.
434  */
435 static inline int sk_stream_min_wspace(struct sock *sk)
436 {
437 	return sk->sk_wmem_queued / 2;
438 }
439 
440 static inline int sk_stream_wspace(struct sock *sk)
441 {
442 	return sk->sk_sndbuf - sk->sk_wmem_queued;
443 }
444 
445 extern void sk_stream_write_space(struct sock *sk);
446 
447 static inline int sk_stream_memory_free(struct sock *sk)
448 {
449 	return sk->sk_wmem_queued < sk->sk_sndbuf;
450 }
451 
452 extern void sk_stream_rfree(struct sk_buff *skb);
453 
454 static inline void sk_stream_set_owner_r(struct sk_buff *skb, struct sock *sk)
455 {
456 	skb->sk = sk;
457 	skb->destructor = sk_stream_rfree;
458 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
459 	sk->sk_forward_alloc -= skb->truesize;
460 }
461 
462 static inline void sk_stream_free_skb(struct sock *sk, struct sk_buff *skb)
463 {
464 	skb_truesize_check(skb);
465 	sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
466 	sk->sk_wmem_queued   -= skb->truesize;
467 	sk->sk_forward_alloc += skb->truesize;
468 	__kfree_skb(skb);
469 }
470 
471 /* The per-socket spinlock must be held here. */
472 static inline void sk_add_backlog(struct sock *sk, struct sk_buff *skb)
473 {
474 	if (!sk->sk_backlog.tail) {
475 		sk->sk_backlog.head = sk->sk_backlog.tail = skb;
476 	} else {
477 		sk->sk_backlog.tail->next = skb;
478 		sk->sk_backlog.tail = skb;
479 	}
480 	skb->next = NULL;
481 }
482 
483 #define sk_wait_event(__sk, __timeo, __condition)		\
484 ({	int rc;							\
485 	release_sock(__sk);					\
486 	rc = __condition;					\
487 	if (!rc) {						\
488 		*(__timeo) = schedule_timeout(*(__timeo));	\
489 	}							\
490 	lock_sock(__sk);					\
491 	rc = __condition;					\
492 	rc;							\
493 })
494 
495 extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
496 extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
497 extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
498 extern int sk_stream_error(struct sock *sk, int flags, int err);
499 extern void sk_stream_kill_queues(struct sock *sk);
500 
501 extern int sk_wait_data(struct sock *sk, long *timeo);
502 
503 struct request_sock_ops;
504 struct timewait_sock_ops;
505 
506 /* Networking protocol blocks we attach to sockets.
507  * socket layer -> transport layer interface
508  * transport -> network interface is defined by struct inet_proto
509  */
510 struct proto {
511 	void			(*close)(struct sock *sk,
512 					long timeout);
513 	int			(*connect)(struct sock *sk,
514 				        struct sockaddr *uaddr,
515 					int addr_len);
516 	int			(*disconnect)(struct sock *sk, int flags);
517 
518 	struct sock *		(*accept) (struct sock *sk, int flags, int *err);
519 
520 	int			(*ioctl)(struct sock *sk, int cmd,
521 					 unsigned long arg);
522 	int			(*init)(struct sock *sk);
523 	int			(*destroy)(struct sock *sk);
524 	void			(*shutdown)(struct sock *sk, int how);
525 	int			(*setsockopt)(struct sock *sk, int level,
526 					int optname, char __user *optval,
527 					int optlen);
528 	int			(*getsockopt)(struct sock *sk, int level,
529 					int optname, char __user *optval,
530 					int __user *option);
531 	int			(*compat_setsockopt)(struct sock *sk,
532 					int level,
533 					int optname, char __user *optval,
534 					int optlen);
535 	int			(*compat_getsockopt)(struct sock *sk,
536 					int level,
537 					int optname, char __user *optval,
538 					int __user *option);
539 	int			(*sendmsg)(struct kiocb *iocb, struct sock *sk,
540 					   struct msghdr *msg, size_t len);
541 	int			(*recvmsg)(struct kiocb *iocb, struct sock *sk,
542 					   struct msghdr *msg,
543 					size_t len, int noblock, int flags,
544 					int *addr_len);
545 	int			(*sendpage)(struct sock *sk, struct page *page,
546 					int offset, size_t size, int flags);
547 	int			(*bind)(struct sock *sk,
548 					struct sockaddr *uaddr, int addr_len);
549 
550 	int			(*backlog_rcv) (struct sock *sk,
551 						struct sk_buff *skb);
552 
553 	/* Keeping track of sk's, looking them up, and port selection methods. */
554 	void			(*hash)(struct sock *sk);
555 	void			(*unhash)(struct sock *sk);
556 	int			(*get_port)(struct sock *sk, unsigned short snum);
557 
558 	/* Memory pressure */
559 	void			(*enter_memory_pressure)(void);
560 	atomic_t		*memory_allocated;	/* Current allocated memory. */
561 	atomic_t		*sockets_allocated;	/* Current number of sockets. */
562 	/*
563 	 * Pressure flag: try to collapse.
564 	 * Technical note: it is used by multiple contexts non atomically.
565 	 * All the sk_stream_mem_schedule() is of this nature: accounting
566 	 * is strict, actions are advisory and have some latency.
567 	 */
568 	int			*memory_pressure;
569 	int			*sysctl_mem;
570 	int			*sysctl_wmem;
571 	int			*sysctl_rmem;
572 	int			max_header;
573 
574 	struct kmem_cache		*slab;
575 	unsigned int		obj_size;
576 
577 	atomic_t		*orphan_count;
578 
579 	struct request_sock_ops	*rsk_prot;
580 	struct timewait_sock_ops *twsk_prot;
581 
582 	struct module		*owner;
583 
584 	char			name[32];
585 
586 	struct list_head	node;
587 #ifdef SOCK_REFCNT_DEBUG
588 	atomic_t		socks;
589 #endif
590 	struct {
591 		int inuse;
592 		u8  __pad[SMP_CACHE_BYTES - sizeof(int)];
593 	} stats[NR_CPUS];
594 };
595 
596 extern int proto_register(struct proto *prot, int alloc_slab);
597 extern void proto_unregister(struct proto *prot);
598 
599 #ifdef SOCK_REFCNT_DEBUG
600 static inline void sk_refcnt_debug_inc(struct sock *sk)
601 {
602 	atomic_inc(&sk->sk_prot->socks);
603 }
604 
605 static inline void sk_refcnt_debug_dec(struct sock *sk)
606 {
607 	atomic_dec(&sk->sk_prot->socks);
608 	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
609 	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
610 }
611 
612 static inline void sk_refcnt_debug_release(const struct sock *sk)
613 {
614 	if (atomic_read(&sk->sk_refcnt) != 1)
615 		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
616 		       sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
617 }
618 #else /* SOCK_REFCNT_DEBUG */
619 #define sk_refcnt_debug_inc(sk) do { } while (0)
620 #define sk_refcnt_debug_dec(sk) do { } while (0)
621 #define sk_refcnt_debug_release(sk) do { } while (0)
622 #endif /* SOCK_REFCNT_DEBUG */
623 
624 /* Called with local bh disabled */
625 static __inline__ void sock_prot_inc_use(struct proto *prot)
626 {
627 	prot->stats[smp_processor_id()].inuse++;
628 }
629 
630 static __inline__ void sock_prot_dec_use(struct proto *prot)
631 {
632 	prot->stats[smp_processor_id()].inuse--;
633 }
634 
635 /* With per-bucket locks this operation is not-atomic, so that
636  * this version is not worse.
637  */
638 static inline void __sk_prot_rehash(struct sock *sk)
639 {
640 	sk->sk_prot->unhash(sk);
641 	sk->sk_prot->hash(sk);
642 }
643 
644 /* About 10 seconds */
645 #define SOCK_DESTROY_TIME (10*HZ)
646 
647 /* Sockets 0-1023 can't be bound to unless you are superuser */
648 #define PROT_SOCK	1024
649 
650 #define SHUTDOWN_MASK	3
651 #define RCV_SHUTDOWN	1
652 #define SEND_SHUTDOWN	2
653 
654 #define SOCK_SNDBUF_LOCK	1
655 #define SOCK_RCVBUF_LOCK	2
656 #define SOCK_BINDADDR_LOCK	4
657 #define SOCK_BINDPORT_LOCK	8
658 
659 /* sock_iocb: used to kick off async processing of socket ios */
660 struct sock_iocb {
661 	struct list_head	list;
662 
663 	int			flags;
664 	int			size;
665 	struct socket		*sock;
666 	struct sock		*sk;
667 	struct scm_cookie	*scm;
668 	struct msghdr		*msg, async_msg;
669 	struct kiocb		*kiocb;
670 };
671 
672 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
673 {
674 	return (struct sock_iocb *)iocb->private;
675 }
676 
677 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
678 {
679 	return si->kiocb;
680 }
681 
682 struct socket_alloc {
683 	struct socket socket;
684 	struct inode vfs_inode;
685 };
686 
687 static inline struct socket *SOCKET_I(struct inode *inode)
688 {
689 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
690 }
691 
692 static inline struct inode *SOCK_INODE(struct socket *socket)
693 {
694 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
695 }
696 
697 extern void __sk_stream_mem_reclaim(struct sock *sk);
698 extern int sk_stream_mem_schedule(struct sock *sk, int size, int kind);
699 
700 #define SK_STREAM_MEM_QUANTUM ((int)PAGE_SIZE)
701 
702 static inline int sk_stream_pages(int amt)
703 {
704 	return (amt + SK_STREAM_MEM_QUANTUM - 1) / SK_STREAM_MEM_QUANTUM;
705 }
706 
707 static inline void sk_stream_mem_reclaim(struct sock *sk)
708 {
709 	if (sk->sk_forward_alloc >= SK_STREAM_MEM_QUANTUM)
710 		__sk_stream_mem_reclaim(sk);
711 }
712 
713 static inline void sk_stream_writequeue_purge(struct sock *sk)
714 {
715 	struct sk_buff *skb;
716 
717 	while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
718 		sk_stream_free_skb(sk, skb);
719 	sk_stream_mem_reclaim(sk);
720 }
721 
722 static inline int sk_stream_rmem_schedule(struct sock *sk, struct sk_buff *skb)
723 {
724 	return (int)skb->truesize <= sk->sk_forward_alloc ||
725 		sk_stream_mem_schedule(sk, skb->truesize, 1);
726 }
727 
728 static inline int sk_stream_wmem_schedule(struct sock *sk, int size)
729 {
730 	return size <= sk->sk_forward_alloc ||
731 	       sk_stream_mem_schedule(sk, size, 0);
732 }
733 
734 /* Used by processes to "lock" a socket state, so that
735  * interrupts and bottom half handlers won't change it
736  * from under us. It essentially blocks any incoming
737  * packets, so that we won't get any new data or any
738  * packets that change the state of the socket.
739  *
740  * While locked, BH processing will add new packets to
741  * the backlog queue.  This queue is processed by the
742  * owner of the socket lock right before it is released.
743  *
744  * Since ~2.3.5 it is also exclusive sleep lock serializing
745  * accesses from user process context.
746  */
747 #define sock_owned_by_user(sk)	((sk)->sk_lock.owner)
748 
749 /*
750  * Macro so as to not evaluate some arguments when
751  * lockdep is not enabled.
752  *
753  * Mark both the sk_lock and the sk_lock.slock as a
754  * per-address-family lock class.
755  */
756 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) 	\
757 do {									\
758 	sk->sk_lock.owner = NULL;					\
759 	init_waitqueue_head(&sk->sk_lock.wq);				\
760 	spin_lock_init(&(sk)->sk_lock.slock);				\
761 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
762 			sizeof((sk)->sk_lock));				\
763 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
764 		       	(skey), (sname));				\
765 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
766 } while (0)
767 
768 extern void FASTCALL(lock_sock_nested(struct sock *sk, int subclass));
769 
770 static inline void lock_sock(struct sock *sk)
771 {
772 	lock_sock_nested(sk, 0);
773 }
774 
775 extern void FASTCALL(release_sock(struct sock *sk));
776 
777 /* BH context may only use the following locking interface. */
778 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
779 #define bh_lock_sock_nested(__sk) \
780 				spin_lock_nested(&((__sk)->sk_lock.slock), \
781 				SINGLE_DEPTH_NESTING)
782 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
783 
784 extern struct sock		*sk_alloc(int family,
785 					  gfp_t priority,
786 					  struct proto *prot, int zero_it);
787 extern void			sk_free(struct sock *sk);
788 extern struct sock		*sk_clone(const struct sock *sk,
789 					  const gfp_t priority);
790 
791 extern struct sk_buff		*sock_wmalloc(struct sock *sk,
792 					      unsigned long size, int force,
793 					      gfp_t priority);
794 extern struct sk_buff		*sock_rmalloc(struct sock *sk,
795 					      unsigned long size, int force,
796 					      gfp_t priority);
797 extern void			sock_wfree(struct sk_buff *skb);
798 extern void			sock_rfree(struct sk_buff *skb);
799 
800 extern int			sock_setsockopt(struct socket *sock, int level,
801 						int op, char __user *optval,
802 						int optlen);
803 
804 extern int			sock_getsockopt(struct socket *sock, int level,
805 						int op, char __user *optval,
806 						int __user *optlen);
807 extern struct sk_buff 		*sock_alloc_send_skb(struct sock *sk,
808 						     unsigned long size,
809 						     int noblock,
810 						     int *errcode);
811 extern void *sock_kmalloc(struct sock *sk, int size,
812 			  gfp_t priority);
813 extern void sock_kfree_s(struct sock *sk, void *mem, int size);
814 extern void sk_send_sigurg(struct sock *sk);
815 
816 /*
817  * Functions to fill in entries in struct proto_ops when a protocol
818  * does not implement a particular function.
819  */
820 extern int                      sock_no_bind(struct socket *,
821 					     struct sockaddr *, int);
822 extern int                      sock_no_connect(struct socket *,
823 						struct sockaddr *, int, int);
824 extern int                      sock_no_socketpair(struct socket *,
825 						   struct socket *);
826 extern int                      sock_no_accept(struct socket *,
827 					       struct socket *, int);
828 extern int                      sock_no_getname(struct socket *,
829 						struct sockaddr *, int *, int);
830 extern unsigned int             sock_no_poll(struct file *, struct socket *,
831 					     struct poll_table_struct *);
832 extern int                      sock_no_ioctl(struct socket *, unsigned int,
833 					      unsigned long);
834 extern int			sock_no_listen(struct socket *, int);
835 extern int                      sock_no_shutdown(struct socket *, int);
836 extern int			sock_no_getsockopt(struct socket *, int , int,
837 						   char __user *, int __user *);
838 extern int			sock_no_setsockopt(struct socket *, int, int,
839 						   char __user *, int);
840 extern int                      sock_no_sendmsg(struct kiocb *, struct socket *,
841 						struct msghdr *, size_t);
842 extern int                      sock_no_recvmsg(struct kiocb *, struct socket *,
843 						struct msghdr *, size_t, int);
844 extern int			sock_no_mmap(struct file *file,
845 					     struct socket *sock,
846 					     struct vm_area_struct *vma);
847 extern ssize_t			sock_no_sendpage(struct socket *sock,
848 						struct page *page,
849 						int offset, size_t size,
850 						int flags);
851 
852 /*
853  * Functions to fill in entries in struct proto_ops when a protocol
854  * uses the inet style.
855  */
856 extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
857 				  char __user *optval, int __user *optlen);
858 extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
859 			       struct msghdr *msg, size_t size, int flags);
860 extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
861 				  char __user *optval, int optlen);
862 extern int compat_sock_common_getsockopt(struct socket *sock, int level,
863 		int optname, char __user *optval, int __user *optlen);
864 extern int compat_sock_common_setsockopt(struct socket *sock, int level,
865 		int optname, char __user *optval, int optlen);
866 
867 extern void sk_common_release(struct sock *sk);
868 
869 /*
870  *	Default socket callbacks and setup code
871  */
872 
873 /* Initialise core socket variables */
874 extern void sock_init_data(struct socket *sock, struct sock *sk);
875 
876 /**
877  *	sk_filter - run a packet through a socket filter
878  *	@sk: sock associated with &sk_buff
879  *	@skb: buffer to filter
880  *	@needlock: set to 1 if the sock is not locked by caller.
881  *
882  * Run the filter code and then cut skb->data to correct size returned by
883  * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller
884  * than pkt_len we keep whole skb->data. This is the socket level
885  * wrapper to sk_run_filter. It returns 0 if the packet should
886  * be accepted or -EPERM if the packet should be tossed.
887  *
888  */
889 
890 static inline int sk_filter(struct sock *sk, struct sk_buff *skb)
891 {
892 	int err;
893 	struct sk_filter *filter;
894 
895 	err = security_sock_rcv_skb(sk, skb);
896 	if (err)
897 		return err;
898 
899 	rcu_read_lock_bh();
900 	filter = sk->sk_filter;
901 	if (filter) {
902 		unsigned int pkt_len = sk_run_filter(skb, filter->insns,
903 				filter->len);
904 		err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM;
905 	}
906  	rcu_read_unlock_bh();
907 
908 	return err;
909 }
910 
911 /**
912  * 	sk_filter_rcu_free: Free a socket filter
913  *	@rcu: rcu_head that contains the sk_filter to free
914  */
915 static inline void sk_filter_rcu_free(struct rcu_head *rcu)
916 {
917 	struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu);
918 	kfree(fp);
919 }
920 
921 /**
922  *	sk_filter_release: Release a socket filter
923  *	@sk: socket
924  *	@fp: filter to remove
925  *
926  *	Remove a filter from a socket and release its resources.
927  */
928 
929 static inline void sk_filter_release(struct sock *sk, struct sk_filter *fp)
930 {
931 	unsigned int size = sk_filter_len(fp);
932 
933 	atomic_sub(size, &sk->sk_omem_alloc);
934 
935 	if (atomic_dec_and_test(&fp->refcnt))
936 		call_rcu_bh(&fp->rcu, sk_filter_rcu_free);
937 }
938 
939 static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
940 {
941 	atomic_inc(&fp->refcnt);
942 	atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
943 }
944 
945 /*
946  * Socket reference counting postulates.
947  *
948  * * Each user of socket SHOULD hold a reference count.
949  * * Each access point to socket (an hash table bucket, reference from a list,
950  *   running timer, skb in flight MUST hold a reference count.
951  * * When reference count hits 0, it means it will never increase back.
952  * * When reference count hits 0, it means that no references from
953  *   outside exist to this socket and current process on current CPU
954  *   is last user and may/should destroy this socket.
955  * * sk_free is called from any context: process, BH, IRQ. When
956  *   it is called, socket has no references from outside -> sk_free
957  *   may release descendant resources allocated by the socket, but
958  *   to the time when it is called, socket is NOT referenced by any
959  *   hash tables, lists etc.
960  * * Packets, delivered from outside (from network or from another process)
961  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
962  *   when they sit in queue. Otherwise, packets will leak to hole, when
963  *   socket is looked up by one cpu and unhasing is made by another CPU.
964  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
965  *   (leak to backlog). Packet socket does all the processing inside
966  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
967  *   use separate SMP lock, so that they are prone too.
968  */
969 
970 /* Ungrab socket and destroy it, if it was the last reference. */
971 static inline void sock_put(struct sock *sk)
972 {
973 	if (atomic_dec_and_test(&sk->sk_refcnt))
974 		sk_free(sk);
975 }
976 
977 extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
978 			  const int nested);
979 
980 /* Detach socket from process context.
981  * Announce socket dead, detach it from wait queue and inode.
982  * Note that parent inode held reference count on this struct sock,
983  * we do not release it in this function, because protocol
984  * probably wants some additional cleanups or even continuing
985  * to work with this socket (TCP).
986  */
987 static inline void sock_orphan(struct sock *sk)
988 {
989 	write_lock_bh(&sk->sk_callback_lock);
990 	sock_set_flag(sk, SOCK_DEAD);
991 	sk->sk_socket = NULL;
992 	sk->sk_sleep  = NULL;
993 	write_unlock_bh(&sk->sk_callback_lock);
994 }
995 
996 static inline void sock_graft(struct sock *sk, struct socket *parent)
997 {
998 	write_lock_bh(&sk->sk_callback_lock);
999 	sk->sk_sleep = &parent->wait;
1000 	parent->sk = sk;
1001 	sk->sk_socket = parent;
1002 	security_sock_graft(sk, parent);
1003 	write_unlock_bh(&sk->sk_callback_lock);
1004 }
1005 
1006 static inline void sock_copy(struct sock *nsk, const struct sock *osk)
1007 {
1008 #ifdef CONFIG_SECURITY_NETWORK
1009 	void *sptr = nsk->sk_security;
1010 #endif
1011 
1012 	memcpy(nsk, osk, osk->sk_prot->obj_size);
1013 #ifdef CONFIG_SECURITY_NETWORK
1014 	nsk->sk_security = sptr;
1015 	security_sk_clone(osk, nsk);
1016 #endif
1017 }
1018 
1019 extern int sock_i_uid(struct sock *sk);
1020 extern unsigned long sock_i_ino(struct sock *sk);
1021 
1022 static inline struct dst_entry *
1023 __sk_dst_get(struct sock *sk)
1024 {
1025 	return sk->sk_dst_cache;
1026 }
1027 
1028 static inline struct dst_entry *
1029 sk_dst_get(struct sock *sk)
1030 {
1031 	struct dst_entry *dst;
1032 
1033 	read_lock(&sk->sk_dst_lock);
1034 	dst = sk->sk_dst_cache;
1035 	if (dst)
1036 		dst_hold(dst);
1037 	read_unlock(&sk->sk_dst_lock);
1038 	return dst;
1039 }
1040 
1041 static inline void
1042 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1043 {
1044 	struct dst_entry *old_dst;
1045 
1046 	old_dst = sk->sk_dst_cache;
1047 	sk->sk_dst_cache = dst;
1048 	dst_release(old_dst);
1049 }
1050 
1051 static inline void
1052 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1053 {
1054 	write_lock(&sk->sk_dst_lock);
1055 	__sk_dst_set(sk, dst);
1056 	write_unlock(&sk->sk_dst_lock);
1057 }
1058 
1059 static inline void
1060 __sk_dst_reset(struct sock *sk)
1061 {
1062 	struct dst_entry *old_dst;
1063 
1064 	old_dst = sk->sk_dst_cache;
1065 	sk->sk_dst_cache = NULL;
1066 	dst_release(old_dst);
1067 }
1068 
1069 static inline void
1070 sk_dst_reset(struct sock *sk)
1071 {
1072 	write_lock(&sk->sk_dst_lock);
1073 	__sk_dst_reset(sk);
1074 	write_unlock(&sk->sk_dst_lock);
1075 }
1076 
1077 extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1078 
1079 extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1080 
1081 static inline int sk_can_gso(const struct sock *sk)
1082 {
1083 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1084 }
1085 
1086 static inline void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1087 {
1088 	__sk_dst_set(sk, dst);
1089 	sk->sk_route_caps = dst->dev->features;
1090 	if (sk->sk_route_caps & NETIF_F_GSO)
1091 		sk->sk_route_caps |= NETIF_F_GSO_MASK;
1092 	if (sk_can_gso(sk)) {
1093 		if (dst->header_len)
1094 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1095 		else
1096 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1097 	}
1098 }
1099 
1100 static inline void sk_charge_skb(struct sock *sk, struct sk_buff *skb)
1101 {
1102 	sk->sk_wmem_queued   += skb->truesize;
1103 	sk->sk_forward_alloc -= skb->truesize;
1104 }
1105 
1106 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1107 				   struct sk_buff *skb, struct page *page,
1108 				   int off, int copy)
1109 {
1110 	if (skb->ip_summed == CHECKSUM_NONE) {
1111 		int err = 0;
1112 		__wsum csum = csum_and_copy_from_user(from,
1113 						     page_address(page) + off,
1114 							    copy, 0, &err);
1115 		if (err)
1116 			return err;
1117 		skb->csum = csum_block_add(skb->csum, csum, skb->len);
1118 	} else if (copy_from_user(page_address(page) + off, from, copy))
1119 		return -EFAULT;
1120 
1121 	skb->len	     += copy;
1122 	skb->data_len	     += copy;
1123 	skb->truesize	     += copy;
1124 	sk->sk_wmem_queued   += copy;
1125 	sk->sk_forward_alloc -= copy;
1126 	return 0;
1127 }
1128 
1129 /*
1130  * 	Queue a received datagram if it will fit. Stream and sequenced
1131  *	protocols can't normally use this as they need to fit buffers in
1132  *	and play with them.
1133  *
1134  * 	Inlined as it's very short and called for pretty much every
1135  *	packet ever received.
1136  */
1137 
1138 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1139 {
1140 	sock_hold(sk);
1141 	skb->sk = sk;
1142 	skb->destructor = sock_wfree;
1143 	atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1144 }
1145 
1146 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1147 {
1148 	skb->sk = sk;
1149 	skb->destructor = sock_rfree;
1150 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1151 }
1152 
1153 extern void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1154 			   unsigned long expires);
1155 
1156 extern void sk_stop_timer(struct sock *sk, struct timer_list* timer);
1157 
1158 extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1159 
1160 static inline int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
1161 {
1162 	/* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
1163 	   number of warnings when compiling with -W --ANK
1164 	 */
1165 	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
1166 	    (unsigned)sk->sk_rcvbuf)
1167 		return -ENOMEM;
1168 	skb_set_owner_r(skb, sk);
1169 	skb_queue_tail(&sk->sk_error_queue, skb);
1170 	if (!sock_flag(sk, SOCK_DEAD))
1171 		sk->sk_data_ready(sk, skb->len);
1172 	return 0;
1173 }
1174 
1175 /*
1176  *	Recover an error report and clear atomically
1177  */
1178 
1179 static inline int sock_error(struct sock *sk)
1180 {
1181 	int err;
1182 	if (likely(!sk->sk_err))
1183 		return 0;
1184 	err = xchg(&sk->sk_err, 0);
1185 	return -err;
1186 }
1187 
1188 static inline unsigned long sock_wspace(struct sock *sk)
1189 {
1190 	int amt = 0;
1191 
1192 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1193 		amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1194 		if (amt < 0)
1195 			amt = 0;
1196 	}
1197 	return amt;
1198 }
1199 
1200 static inline void sk_wake_async(struct sock *sk, int how, int band)
1201 {
1202 	if (sk->sk_socket && sk->sk_socket->fasync_list)
1203 		sock_wake_async(sk->sk_socket, how, band);
1204 }
1205 
1206 #define SOCK_MIN_SNDBUF 2048
1207 #define SOCK_MIN_RCVBUF 256
1208 
1209 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1210 {
1211 	if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1212 		sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued / 2);
1213 		sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1214 	}
1215 }
1216 
1217 static inline struct sk_buff *sk_stream_alloc_pskb(struct sock *sk,
1218 						   int size, int mem,
1219 						   gfp_t gfp)
1220 {
1221 	struct sk_buff *skb;
1222 	int hdr_len;
1223 
1224 	hdr_len = SKB_DATA_ALIGN(sk->sk_prot->max_header);
1225 	skb = alloc_skb_fclone(size + hdr_len, gfp);
1226 	if (skb) {
1227 		skb->truesize += mem;
1228 		if (sk_stream_wmem_schedule(sk, skb->truesize)) {
1229 			skb_reserve(skb, hdr_len);
1230 			return skb;
1231 		}
1232 		__kfree_skb(skb);
1233 	} else {
1234 		sk->sk_prot->enter_memory_pressure();
1235 		sk_stream_moderate_sndbuf(sk);
1236 	}
1237 	return NULL;
1238 }
1239 
1240 static inline struct sk_buff *sk_stream_alloc_skb(struct sock *sk,
1241 						  int size,
1242 						  gfp_t gfp)
1243 {
1244 	return sk_stream_alloc_pskb(sk, size, 0, gfp);
1245 }
1246 
1247 static inline struct page *sk_stream_alloc_page(struct sock *sk)
1248 {
1249 	struct page *page = NULL;
1250 
1251 	page = alloc_pages(sk->sk_allocation, 0);
1252 	if (!page) {
1253 		sk->sk_prot->enter_memory_pressure();
1254 		sk_stream_moderate_sndbuf(sk);
1255 	}
1256 	return page;
1257 }
1258 
1259 #define sk_stream_for_retrans_queue(skb, sk)				\
1260 		for (skb = (sk)->sk_write_queue.next;			\
1261 		     (skb != (sk)->sk_send_head) &&			\
1262 		     (skb != (struct sk_buff *)&(sk)->sk_write_queue);	\
1263 		     skb = skb->next)
1264 
1265 /*from STCP for fast SACK Process*/
1266 #define sk_stream_for_retrans_queue_from(skb, sk)			\
1267 		for (; (skb != (sk)->sk_send_head) &&                   \
1268 		     (skb != (struct sk_buff *)&(sk)->sk_write_queue);	\
1269 		     skb = skb->next)
1270 
1271 /*
1272  *	Default write policy as shown to user space via poll/select/SIGIO
1273  */
1274 static inline int sock_writeable(const struct sock *sk)
1275 {
1276 	return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf / 2);
1277 }
1278 
1279 static inline gfp_t gfp_any(void)
1280 {
1281 	return in_atomic() ? GFP_ATOMIC : GFP_KERNEL;
1282 }
1283 
1284 static inline long sock_rcvtimeo(const struct sock *sk, int noblock)
1285 {
1286 	return noblock ? 0 : sk->sk_rcvtimeo;
1287 }
1288 
1289 static inline long sock_sndtimeo(const struct sock *sk, int noblock)
1290 {
1291 	return noblock ? 0 : sk->sk_sndtimeo;
1292 }
1293 
1294 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
1295 {
1296 	return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
1297 }
1298 
1299 /* Alas, with timeout socket operations are not restartable.
1300  * Compare this to poll().
1301  */
1302 static inline int sock_intr_errno(long timeo)
1303 {
1304 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1305 }
1306 
1307 static __inline__ void
1308 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
1309 {
1310 	struct timeval stamp;
1311 
1312 	skb_get_timestamp(skb, &stamp);
1313 	if (sock_flag(sk, SOCK_RCVTSTAMP)) {
1314 		/* Race occurred between timestamp enabling and packet
1315 		   receiving.  Fill in the current time for now. */
1316 		if (stamp.tv_sec == 0)
1317 			do_gettimeofday(&stamp);
1318 		skb_set_timestamp(skb, &stamp);
1319 		put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP, sizeof(struct timeval),
1320 			 &stamp);
1321 	} else
1322 		sk->sk_stamp = stamp;
1323 }
1324 
1325 /**
1326  * sk_eat_skb - Release a skb if it is no longer needed
1327  * @sk: socket to eat this skb from
1328  * @skb: socket buffer to eat
1329  * @copied_early: flag indicating whether DMA operations copied this data early
1330  *
1331  * This routine must be called with interrupts disabled or with the socket
1332  * locked so that the sk_buff queue operation is ok.
1333 */
1334 #ifdef CONFIG_NET_DMA
1335 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1336 {
1337 	__skb_unlink(skb, &sk->sk_receive_queue);
1338 	if (!copied_early)
1339 		__kfree_skb(skb);
1340 	else
1341 		__skb_queue_tail(&sk->sk_async_wait_queue, skb);
1342 }
1343 #else
1344 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1345 {
1346 	__skb_unlink(skb, &sk->sk_receive_queue);
1347 	__kfree_skb(skb);
1348 }
1349 #endif
1350 
1351 extern void sock_enable_timestamp(struct sock *sk);
1352 extern int sock_get_timestamp(struct sock *, struct timeval __user *);
1353 
1354 /*
1355  *	Enable debug/info messages
1356  */
1357 
1358 #ifdef CONFIG_NETDEBUG
1359 #define NETDEBUG(fmt, args...)	printk(fmt,##args)
1360 #define LIMIT_NETDEBUG(fmt, args...) do { if (net_ratelimit()) printk(fmt,##args); } while(0)
1361 #else
1362 #define NETDEBUG(fmt, args...)	do { } while (0)
1363 #define LIMIT_NETDEBUG(fmt, args...) do { } while(0)
1364 #endif
1365 
1366 /*
1367  * Macros for sleeping on a socket. Use them like this:
1368  *
1369  * SOCK_SLEEP_PRE(sk)
1370  * if (condition)
1371  * 	schedule();
1372  * SOCK_SLEEP_POST(sk)
1373  *
1374  * N.B. These are now obsolete and were, afaik, only ever used in DECnet
1375  * and when the last use of them in DECnet has gone, I'm intending to
1376  * remove them.
1377  */
1378 
1379 #define SOCK_SLEEP_PRE(sk) 	{ struct task_struct *tsk = current; \
1380 				DECLARE_WAITQUEUE(wait, tsk); \
1381 				tsk->state = TASK_INTERRUPTIBLE; \
1382 				add_wait_queue((sk)->sk_sleep, &wait); \
1383 				release_sock(sk);
1384 
1385 #define SOCK_SLEEP_POST(sk)	tsk->state = TASK_RUNNING; \
1386 				remove_wait_queue((sk)->sk_sleep, &wait); \
1387 				lock_sock(sk); \
1388 				}
1389 
1390 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
1391 {
1392 	if (valbool)
1393 		sock_set_flag(sk, bit);
1394 	else
1395 		sock_reset_flag(sk, bit);
1396 }
1397 
1398 extern __u32 sysctl_wmem_max;
1399 extern __u32 sysctl_rmem_max;
1400 
1401 #ifdef CONFIG_NET
1402 int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg);
1403 #else
1404 static inline int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
1405 {
1406 	return -ENODEV;
1407 }
1408 #endif
1409 
1410 extern void sk_init(void);
1411 
1412 #ifdef CONFIG_SYSCTL
1413 extern struct ctl_table core_table[];
1414 #endif
1415 
1416 extern int sysctl_optmem_max;
1417 
1418 extern __u32 sysctl_wmem_default;
1419 extern __u32 sysctl_rmem_default;
1420 
1421 #endif	/* _SOCK_H */
1422