xref: /linux/include/net/sock.h (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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/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 SOCK_DBG debugging facility. */
65 #define SOCK_DEBUGGING
66 #ifdef SOCK_DEBUGGING
67 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
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 	/*
83 	 * We express the mutex-alike socket_lock semantics
84 	 * to the lock validator by explicitly managing
85 	 * the slock as a lock variant (in addition to
86 	 * the slock itself):
87 	 */
88 #ifdef CONFIG_DEBUG_LOCK_ALLOC
89 	struct lockdep_map dep_map;
90 #endif
91 } socket_lock_t;
92 
93 struct sock;
94 struct proto;
95 
96 /**
97  *	struct sock_common - minimal network layer representation of sockets
98  *	@skc_family: network address family
99  *	@skc_state: Connection state
100  *	@skc_reuse: %SO_REUSEADDR setting
101  *	@skc_bound_dev_if: bound device index if != 0
102  *	@skc_node: main hash linkage for various protocol lookup tables
103  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
104  *	@skc_refcnt: reference count
105  *	@skc_hash: hash value used with various protocol lookup tables
106  *	@skc_prot: protocol handlers inside a network family
107  *
108  *	This is the minimal network layer representation of sockets, the header
109  *	for struct sock and struct inet_timewait_sock.
110  */
111 struct sock_common {
112 	unsigned short		skc_family;
113 	volatile unsigned char	skc_state;
114 	unsigned char		skc_reuse;
115 	int			skc_bound_dev_if;
116 	struct hlist_node	skc_node;
117 	struct hlist_node	skc_bind_node;
118 	atomic_t		skc_refcnt;
119 	unsigned int		skc_hash;
120 	struct proto		*skc_prot;
121 };
122 
123 /**
124   *	struct sock - network layer representation of sockets
125   *	@__sk_common: shared layout with inet_timewait_sock
126   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
127   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
128   *	@sk_lock:	synchronizer
129   *	@sk_rcvbuf: size of receive buffer in bytes
130   *	@sk_sleep: sock wait queue
131   *	@sk_dst_cache: destination cache
132   *	@sk_dst_lock: destination cache lock
133   *	@sk_policy: flow policy
134   *	@sk_rmem_alloc: receive queue bytes committed
135   *	@sk_receive_queue: incoming packets
136   *	@sk_wmem_alloc: transmit queue bytes committed
137   *	@sk_write_queue: Packet sending queue
138   *	@sk_async_wait_queue: DMA copied packets
139   *	@sk_omem_alloc: "o" is "option" or "other"
140   *	@sk_wmem_queued: persistent queue size
141   *	@sk_forward_alloc: space allocated forward
142   *	@sk_allocation: allocation mode
143   *	@sk_sndbuf: size of send buffer in bytes
144   *	@sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, %SO_OOBINLINE settings
145   *	@sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
146   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
147   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
148   *	@sk_lingertime: %SO_LINGER l_linger setting
149   *	@sk_backlog: always used with the per-socket spinlock held
150   *	@sk_callback_lock: used with the callbacks in the end of this struct
151   *	@sk_error_queue: rarely used
152   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt, IPV6_ADDRFORM for instance)
153   *	@sk_err: last error
154   *	@sk_err_soft: errors that don't cause failure but are the cause of a persistent failure not just 'timed out'
155   *	@sk_ack_backlog: current listen backlog
156   *	@sk_max_ack_backlog: listen backlog set in listen()
157   *	@sk_priority: %SO_PRIORITY setting
158   *	@sk_type: socket type (%SOCK_STREAM, etc)
159   *	@sk_protocol: which protocol this socket belongs in this network family
160   *	@sk_peercred: %SO_PEERCRED setting
161   *	@sk_rcvlowat: %SO_RCVLOWAT setting
162   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
163   *	@sk_sndtimeo: %SO_SNDTIMEO setting
164   *	@sk_filter: socket filtering instructions
165   *	@sk_protinfo: private area, net family specific, when not using slab
166   *	@sk_timer: sock cleanup timer
167   *	@sk_stamp: time stamp of last packet received
168   *	@sk_socket: Identd and reporting IO signals
169   *	@sk_user_data: RPC layer private data
170   *	@sk_sndmsg_page: cached page for sendmsg
171   *	@sk_sndmsg_off: cached offset for sendmsg
172   *	@sk_send_head: front of stuff to transmit
173   *	@sk_security: used by security modules
174   *	@sk_write_pending: a write to stream socket waits to start
175   *	@sk_state_change: callback to indicate change in the state of the sock
176   *	@sk_data_ready: callback to indicate there is data to be processed
177   *	@sk_write_space: callback to indicate there is bf sending space available
178   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
179   *	@sk_backlog_rcv: callback to process the backlog
180   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
181  */
182 struct sock {
183 	/*
184 	 * Now struct inet_timewait_sock also uses sock_common, so please just
185 	 * don't add nothing before this first member (__sk_common) --acme
186 	 */
187 	struct sock_common	__sk_common;
188 #define sk_family		__sk_common.skc_family
189 #define sk_state		__sk_common.skc_state
190 #define sk_reuse		__sk_common.skc_reuse
191 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
192 #define sk_node			__sk_common.skc_node
193 #define sk_bind_node		__sk_common.skc_bind_node
194 #define sk_refcnt		__sk_common.skc_refcnt
195 #define sk_hash			__sk_common.skc_hash
196 #define sk_prot			__sk_common.skc_prot
197 	unsigned char		sk_shutdown : 2,
198 				sk_no_check : 2,
199 				sk_userlocks : 4;
200 	unsigned char		sk_protocol;
201 	unsigned short		sk_type;
202 	int			sk_rcvbuf;
203 	socket_lock_t		sk_lock;
204 	wait_queue_head_t	*sk_sleep;
205 	struct dst_entry	*sk_dst_cache;
206 	struct xfrm_policy	*sk_policy[2];
207 	rwlock_t		sk_dst_lock;
208 	atomic_t		sk_rmem_alloc;
209 	atomic_t		sk_wmem_alloc;
210 	atomic_t		sk_omem_alloc;
211 	struct sk_buff_head	sk_receive_queue;
212 	struct sk_buff_head	sk_write_queue;
213 	struct sk_buff_head	sk_async_wait_queue;
214 	int			sk_wmem_queued;
215 	int			sk_forward_alloc;
216 	gfp_t			sk_allocation;
217 	int			sk_sndbuf;
218 	int			sk_route_caps;
219 	int			sk_gso_type;
220 	int			sk_rcvlowat;
221 	unsigned long 		sk_flags;
222 	unsigned long	        sk_lingertime;
223 	/*
224 	 * The backlog queue is special, it is always used with
225 	 * the per-socket spinlock held and requires low latency
226 	 * access. Therefore we special case it's implementation.
227 	 */
228 	struct {
229 		struct sk_buff *head;
230 		struct sk_buff *tail;
231 	} sk_backlog;
232 	struct sk_buff_head	sk_error_queue;
233 	struct proto		*sk_prot_creator;
234 	rwlock_t		sk_callback_lock;
235 	int			sk_err,
236 				sk_err_soft;
237 	unsigned short		sk_ack_backlog;
238 	unsigned short		sk_max_ack_backlog;
239 	__u32			sk_priority;
240 	struct ucred		sk_peercred;
241 	long			sk_rcvtimeo;
242 	long			sk_sndtimeo;
243 	struct sk_filter      	*sk_filter;
244 	void			*sk_protinfo;
245 	struct timer_list	sk_timer;
246 	struct timeval		sk_stamp;
247 	struct socket		*sk_socket;
248 	void			*sk_user_data;
249 	struct page		*sk_sndmsg_page;
250 	struct sk_buff		*sk_send_head;
251 	__u32			sk_sndmsg_off;
252 	int			sk_write_pending;
253 	void			*sk_security;
254 	void			(*sk_state_change)(struct sock *sk);
255 	void			(*sk_data_ready)(struct sock *sk, int bytes);
256 	void			(*sk_write_space)(struct sock *sk);
257 	void			(*sk_error_report)(struct sock *sk);
258   	int			(*sk_backlog_rcv)(struct sock *sk,
259 						  struct sk_buff *skb);
260 	void                    (*sk_destruct)(struct sock *sk);
261 };
262 
263 /*
264  * Hashed lists helper routines
265  */
266 static inline struct sock *__sk_head(const struct hlist_head *head)
267 {
268 	return hlist_entry(head->first, struct sock, sk_node);
269 }
270 
271 static inline struct sock *sk_head(const struct hlist_head *head)
272 {
273 	return hlist_empty(head) ? NULL : __sk_head(head);
274 }
275 
276 static inline struct sock *sk_next(const struct sock *sk)
277 {
278 	return sk->sk_node.next ?
279 		hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
280 }
281 
282 static inline int sk_unhashed(const struct sock *sk)
283 {
284 	return hlist_unhashed(&sk->sk_node);
285 }
286 
287 static inline int sk_hashed(const struct sock *sk)
288 {
289 	return !sk_unhashed(sk);
290 }
291 
292 static __inline__ void sk_node_init(struct hlist_node *node)
293 {
294 	node->pprev = NULL;
295 }
296 
297 static __inline__ void __sk_del_node(struct sock *sk)
298 {
299 	__hlist_del(&sk->sk_node);
300 }
301 
302 static __inline__ int __sk_del_node_init(struct sock *sk)
303 {
304 	if (sk_hashed(sk)) {
305 		__sk_del_node(sk);
306 		sk_node_init(&sk->sk_node);
307 		return 1;
308 	}
309 	return 0;
310 }
311 
312 /* Grab socket reference count. This operation is valid only
313    when sk is ALREADY grabbed f.e. it is found in hash table
314    or a list and the lookup is made under lock preventing hash table
315    modifications.
316  */
317 
318 static inline void sock_hold(struct sock *sk)
319 {
320 	atomic_inc(&sk->sk_refcnt);
321 }
322 
323 /* Ungrab socket in the context, which assumes that socket refcnt
324    cannot hit zero, f.e. it is true in context of any socketcall.
325  */
326 static inline void __sock_put(struct sock *sk)
327 {
328 	atomic_dec(&sk->sk_refcnt);
329 }
330 
331 static __inline__ int sk_del_node_init(struct sock *sk)
332 {
333 	int rc = __sk_del_node_init(sk);
334 
335 	if (rc) {
336 		/* paranoid for a while -acme */
337 		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
338 		__sock_put(sk);
339 	}
340 	return rc;
341 }
342 
343 static __inline__ void __sk_add_node(struct sock *sk, struct hlist_head *list)
344 {
345 	hlist_add_head(&sk->sk_node, list);
346 }
347 
348 static __inline__ void sk_add_node(struct sock *sk, struct hlist_head *list)
349 {
350 	sock_hold(sk);
351 	__sk_add_node(sk, list);
352 }
353 
354 static __inline__ void __sk_del_bind_node(struct sock *sk)
355 {
356 	__hlist_del(&sk->sk_bind_node);
357 }
358 
359 static __inline__ void sk_add_bind_node(struct sock *sk,
360 					struct hlist_head *list)
361 {
362 	hlist_add_head(&sk->sk_bind_node, list);
363 }
364 
365 #define sk_for_each(__sk, node, list) \
366 	hlist_for_each_entry(__sk, node, list, sk_node)
367 #define sk_for_each_from(__sk, node) \
368 	if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
369 		hlist_for_each_entry_from(__sk, node, sk_node)
370 #define sk_for_each_continue(__sk, node) \
371 	if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
372 		hlist_for_each_entry_continue(__sk, node, sk_node)
373 #define sk_for_each_safe(__sk, node, tmp, list) \
374 	hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
375 #define sk_for_each_bound(__sk, node, list) \
376 	hlist_for_each_entry(__sk, node, list, sk_bind_node)
377 
378 /* Sock flags */
379 enum sock_flags {
380 	SOCK_DEAD,
381 	SOCK_DONE,
382 	SOCK_URGINLINE,
383 	SOCK_KEEPOPEN,
384 	SOCK_LINGER,
385 	SOCK_DESTROY,
386 	SOCK_BROADCAST,
387 	SOCK_TIMESTAMP,
388 	SOCK_ZAPPED,
389 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
390 	SOCK_DBG, /* %SO_DEBUG setting */
391 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
392 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
393 	SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
394 };
395 
396 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
397 {
398 	nsk->sk_flags = osk->sk_flags;
399 }
400 
401 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
402 {
403 	__set_bit(flag, &sk->sk_flags);
404 }
405 
406 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
407 {
408 	__clear_bit(flag, &sk->sk_flags);
409 }
410 
411 static inline int sock_flag(struct sock *sk, enum sock_flags flag)
412 {
413 	return test_bit(flag, &sk->sk_flags);
414 }
415 
416 static inline void sk_acceptq_removed(struct sock *sk)
417 {
418 	sk->sk_ack_backlog--;
419 }
420 
421 static inline void sk_acceptq_added(struct sock *sk)
422 {
423 	sk->sk_ack_backlog++;
424 }
425 
426 static inline int sk_acceptq_is_full(struct sock *sk)
427 {
428 	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
429 }
430 
431 /*
432  * Compute minimal free write space needed to queue new packets.
433  */
434 static inline int sk_stream_min_wspace(struct sock *sk)
435 {
436 	return sk->sk_wmem_queued / 2;
437 }
438 
439 static inline int sk_stream_wspace(struct sock *sk)
440 {
441 	return sk->sk_sndbuf - sk->sk_wmem_queued;
442 }
443 
444 extern void sk_stream_write_space(struct sock *sk);
445 
446 static inline int sk_stream_memory_free(struct sock *sk)
447 {
448 	return sk->sk_wmem_queued < sk->sk_sndbuf;
449 }
450 
451 extern void sk_stream_rfree(struct sk_buff *skb);
452 
453 static inline void sk_stream_set_owner_r(struct sk_buff *skb, struct sock *sk)
454 {
455 	skb->sk = sk;
456 	skb->destructor = sk_stream_rfree;
457 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
458 	sk->sk_forward_alloc -= skb->truesize;
459 }
460 
461 static inline void sk_stream_free_skb(struct sock *sk, struct sk_buff *skb)
462 {
463 	skb_truesize_check(skb);
464 	sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
465 	sk->sk_wmem_queued   -= skb->truesize;
466 	sk->sk_forward_alloc += skb->truesize;
467 	__kfree_skb(skb);
468 }
469 
470 /* The per-socket spinlock must be held here. */
471 static inline void sk_add_backlog(struct sock *sk, struct sk_buff *skb)
472 {
473 	if (!sk->sk_backlog.tail) {
474 		sk->sk_backlog.head = sk->sk_backlog.tail = skb;
475 	} else {
476 		sk->sk_backlog.tail->next = skb;
477 		sk->sk_backlog.tail = skb;
478 	}
479 	skb->next = NULL;
480 }
481 
482 #define sk_wait_event(__sk, __timeo, __condition)		\
483 ({	int rc;							\
484 	release_sock(__sk);					\
485 	rc = __condition;					\
486 	if (!rc) {						\
487 		*(__timeo) = schedule_timeout(*(__timeo));	\
488 	}							\
489 	lock_sock(__sk);					\
490 	rc = __condition;					\
491 	rc;							\
492 })
493 
494 extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
495 extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
496 extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
497 extern int sk_stream_error(struct sock *sk, int flags, int err);
498 extern void sk_stream_kill_queues(struct sock *sk);
499 
500 extern int sk_wait_data(struct sock *sk, long *timeo);
501 
502 struct request_sock_ops;
503 struct timewait_sock_ops;
504 
505 /* Networking protocol blocks we attach to sockets.
506  * socket layer -> transport layer interface
507  * transport -> network interface is defined by struct inet_proto
508  */
509 struct proto {
510 	void			(*close)(struct sock *sk,
511 					long timeout);
512 	int			(*connect)(struct sock *sk,
513 				        struct sockaddr *uaddr,
514 					int addr_len);
515 	int			(*disconnect)(struct sock *sk, int flags);
516 
517 	struct sock *		(*accept) (struct sock *sk, int flags, int *err);
518 
519 	int			(*ioctl)(struct sock *sk, int cmd,
520 					 unsigned long arg);
521 	int			(*init)(struct sock *sk);
522 	int			(*destroy)(struct sock *sk);
523 	void			(*shutdown)(struct sock *sk, int how);
524 	int			(*setsockopt)(struct sock *sk, int level,
525 					int optname, char __user *optval,
526 					int optlen);
527 	int			(*getsockopt)(struct sock *sk, int level,
528 					int optname, char __user *optval,
529 					int __user *option);
530 	int			(*compat_setsockopt)(struct sock *sk,
531 					int level,
532 					int optname, char __user *optval,
533 					int optlen);
534 	int			(*compat_getsockopt)(struct sock *sk,
535 					int level,
536 					int optname, char __user *optval,
537 					int __user *option);
538 	int			(*sendmsg)(struct kiocb *iocb, struct sock *sk,
539 					   struct msghdr *msg, size_t len);
540 	int			(*recvmsg)(struct kiocb *iocb, struct sock *sk,
541 					   struct msghdr *msg,
542 					size_t len, int noblock, int flags,
543 					int *addr_len);
544 	int			(*sendpage)(struct sock *sk, struct page *page,
545 					int offset, size_t size, int flags);
546 	int			(*bind)(struct sock *sk,
547 					struct sockaddr *uaddr, int addr_len);
548 
549 	int			(*backlog_rcv) (struct sock *sk,
550 						struct sk_buff *skb);
551 
552 	/* Keeping track of sk's, looking them up, and port selection methods. */
553 	void			(*hash)(struct sock *sk);
554 	void			(*unhash)(struct sock *sk);
555 	int			(*get_port)(struct sock *sk, unsigned short snum);
556 
557 	/* Memory pressure */
558 	void			(*enter_memory_pressure)(void);
559 	atomic_t		*memory_allocated;	/* Current allocated memory. */
560 	atomic_t		*sockets_allocated;	/* Current number of sockets. */
561 	/*
562 	 * Pressure flag: try to collapse.
563 	 * Technical note: it is used by multiple contexts non atomically.
564 	 * All the sk_stream_mem_schedule() is of this nature: accounting
565 	 * is strict, actions are advisory and have some latency.
566 	 */
567 	int			*memory_pressure;
568 	int			*sysctl_mem;
569 	int			*sysctl_wmem;
570 	int			*sysctl_rmem;
571 	int			max_header;
572 
573 	kmem_cache_t		*slab;
574 	unsigned int		obj_size;
575 
576 	atomic_t		*orphan_count;
577 
578 	struct request_sock_ops	*rsk_prot;
579 	struct timewait_sock_ops *twsk_prot;
580 
581 	struct module		*owner;
582 
583 	char			name[32];
584 
585 	struct list_head	node;
586 #ifdef SOCK_REFCNT_DEBUG
587 	atomic_t		socks;
588 #endif
589 	struct {
590 		int inuse;
591 		u8  __pad[SMP_CACHE_BYTES - sizeof(int)];
592 	} stats[NR_CPUS];
593 };
594 
595 extern int proto_register(struct proto *prot, int alloc_slab);
596 extern void proto_unregister(struct proto *prot);
597 
598 #ifdef SOCK_REFCNT_DEBUG
599 static inline void sk_refcnt_debug_inc(struct sock *sk)
600 {
601 	atomic_inc(&sk->sk_prot->socks);
602 }
603 
604 static inline void sk_refcnt_debug_dec(struct sock *sk)
605 {
606 	atomic_dec(&sk->sk_prot->socks);
607 	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
608 	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
609 }
610 
611 static inline void sk_refcnt_debug_release(const struct sock *sk)
612 {
613 	if (atomic_read(&sk->sk_refcnt) != 1)
614 		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
615 		       sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
616 }
617 #else /* SOCK_REFCNT_DEBUG */
618 #define sk_refcnt_debug_inc(sk) do { } while (0)
619 #define sk_refcnt_debug_dec(sk) do { } while (0)
620 #define sk_refcnt_debug_release(sk) do { } while (0)
621 #endif /* SOCK_REFCNT_DEBUG */
622 
623 /* Called with local bh disabled */
624 static __inline__ void sock_prot_inc_use(struct proto *prot)
625 {
626 	prot->stats[smp_processor_id()].inuse++;
627 }
628 
629 static __inline__ void sock_prot_dec_use(struct proto *prot)
630 {
631 	prot->stats[smp_processor_id()].inuse--;
632 }
633 
634 /* With per-bucket locks this operation is not-atomic, so that
635  * this version is not worse.
636  */
637 static inline void __sk_prot_rehash(struct sock *sk)
638 {
639 	sk->sk_prot->unhash(sk);
640 	sk->sk_prot->hash(sk);
641 }
642 
643 /* About 10 seconds */
644 #define SOCK_DESTROY_TIME (10*HZ)
645 
646 /* Sockets 0-1023 can't be bound to unless you are superuser */
647 #define PROT_SOCK	1024
648 
649 #define SHUTDOWN_MASK	3
650 #define RCV_SHUTDOWN	1
651 #define SEND_SHUTDOWN	2
652 
653 #define SOCK_SNDBUF_LOCK	1
654 #define SOCK_RCVBUF_LOCK	2
655 #define SOCK_BINDADDR_LOCK	4
656 #define SOCK_BINDPORT_LOCK	8
657 
658 /* sock_iocb: used to kick off async processing of socket ios */
659 struct sock_iocb {
660 	struct list_head	list;
661 
662 	int			flags;
663 	int			size;
664 	struct socket		*sock;
665 	struct sock		*sk;
666 	struct scm_cookie	*scm;
667 	struct msghdr		*msg, async_msg;
668 	struct iovec		async_iov;
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 extern void FASTCALL(lock_sock(struct sock *sk));
750 extern void FASTCALL(release_sock(struct sock *sk));
751 
752 /* BH context may only use the following locking interface. */
753 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
754 #define bh_lock_sock_nested(__sk) \
755 				spin_lock_nested(&((__sk)->sk_lock.slock), \
756 				SINGLE_DEPTH_NESTING)
757 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
758 
759 extern struct sock		*sk_alloc(int family,
760 					  gfp_t priority,
761 					  struct proto *prot, int zero_it);
762 extern void			sk_free(struct sock *sk);
763 extern struct sock		*sk_clone(const struct sock *sk,
764 					  const gfp_t priority);
765 
766 extern struct sk_buff		*sock_wmalloc(struct sock *sk,
767 					      unsigned long size, int force,
768 					      gfp_t priority);
769 extern struct sk_buff		*sock_rmalloc(struct sock *sk,
770 					      unsigned long size, int force,
771 					      gfp_t priority);
772 extern void			sock_wfree(struct sk_buff *skb);
773 extern void			sock_rfree(struct sk_buff *skb);
774 
775 extern int			sock_setsockopt(struct socket *sock, int level,
776 						int op, char __user *optval,
777 						int optlen);
778 
779 extern int			sock_getsockopt(struct socket *sock, int level,
780 						int op, char __user *optval,
781 						int __user *optlen);
782 extern struct sk_buff 		*sock_alloc_send_skb(struct sock *sk,
783 						     unsigned long size,
784 						     int noblock,
785 						     int *errcode);
786 extern void *sock_kmalloc(struct sock *sk, int size,
787 			  gfp_t priority);
788 extern void sock_kfree_s(struct sock *sk, void *mem, int size);
789 extern void sk_send_sigurg(struct sock *sk);
790 
791 /*
792  * Functions to fill in entries in struct proto_ops when a protocol
793  * does not implement a particular function.
794  */
795 extern int                      sock_no_bind(struct socket *,
796 					     struct sockaddr *, int);
797 extern int                      sock_no_connect(struct socket *,
798 						struct sockaddr *, int, int);
799 extern int                      sock_no_socketpair(struct socket *,
800 						   struct socket *);
801 extern int                      sock_no_accept(struct socket *,
802 					       struct socket *, int);
803 extern int                      sock_no_getname(struct socket *,
804 						struct sockaddr *, int *, int);
805 extern unsigned int             sock_no_poll(struct file *, struct socket *,
806 					     struct poll_table_struct *);
807 extern int                      sock_no_ioctl(struct socket *, unsigned int,
808 					      unsigned long);
809 extern int			sock_no_listen(struct socket *, int);
810 extern int                      sock_no_shutdown(struct socket *, int);
811 extern int			sock_no_getsockopt(struct socket *, int , int,
812 						   char __user *, int __user *);
813 extern int			sock_no_setsockopt(struct socket *, int, int,
814 						   char __user *, int);
815 extern int                      sock_no_sendmsg(struct kiocb *, struct socket *,
816 						struct msghdr *, size_t);
817 extern int                      sock_no_recvmsg(struct kiocb *, struct socket *,
818 						struct msghdr *, size_t, int);
819 extern int			sock_no_mmap(struct file *file,
820 					     struct socket *sock,
821 					     struct vm_area_struct *vma);
822 extern ssize_t			sock_no_sendpage(struct socket *sock,
823 						struct page *page,
824 						int offset, size_t size,
825 						int flags);
826 
827 /*
828  * Functions to fill in entries in struct proto_ops when a protocol
829  * uses the inet style.
830  */
831 extern int sock_common_getsockopt(struct socket *sock, int level, int optname,
832 				  char __user *optval, int __user *optlen);
833 extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
834 			       struct msghdr *msg, size_t size, int flags);
835 extern int sock_common_setsockopt(struct socket *sock, int level, int optname,
836 				  char __user *optval, int optlen);
837 extern int compat_sock_common_getsockopt(struct socket *sock, int level,
838 		int optname, char __user *optval, int __user *optlen);
839 extern int compat_sock_common_setsockopt(struct socket *sock, int level,
840 		int optname, char __user *optval, int optlen);
841 
842 extern void sk_common_release(struct sock *sk);
843 
844 /*
845  *	Default socket callbacks and setup code
846  */
847 
848 /* Initialise core socket variables */
849 extern void sock_init_data(struct socket *sock, struct sock *sk);
850 
851 /**
852  *	sk_filter - run a packet through a socket filter
853  *	@sk: sock associated with &sk_buff
854  *	@skb: buffer to filter
855  *	@needlock: set to 1 if the sock is not locked by caller.
856  *
857  * Run the filter code and then cut skb->data to correct size returned by
858  * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller
859  * than pkt_len we keep whole skb->data. This is the socket level
860  * wrapper to sk_run_filter. It returns 0 if the packet should
861  * be accepted or -EPERM if the packet should be tossed.
862  *
863  */
864 
865 static inline int sk_filter(struct sock *sk, struct sk_buff *skb, int needlock)
866 {
867 	int err;
868 
869 	err = security_sock_rcv_skb(sk, skb);
870 	if (err)
871 		return err;
872 
873 	if (sk->sk_filter) {
874 		struct sk_filter *filter;
875 
876 		if (needlock)
877 			bh_lock_sock(sk);
878 
879 		filter = sk->sk_filter;
880 		if (filter) {
881 			unsigned int pkt_len = sk_run_filter(skb, filter->insns,
882 							     filter->len);
883 			err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM;
884 		}
885 
886 		if (needlock)
887 			bh_unlock_sock(sk);
888 	}
889 	return err;
890 }
891 
892 /**
893  *	sk_filter_release: Release a socket filter
894  *	@sk: socket
895  *	@fp: filter to remove
896  *
897  *	Remove a filter from a socket and release its resources.
898  */
899 
900 static inline void sk_filter_release(struct sock *sk, struct sk_filter *fp)
901 {
902 	unsigned int size = sk_filter_len(fp);
903 
904 	atomic_sub(size, &sk->sk_omem_alloc);
905 
906 	if (atomic_dec_and_test(&fp->refcnt))
907 		kfree(fp);
908 }
909 
910 static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp)
911 {
912 	atomic_inc(&fp->refcnt);
913 	atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc);
914 }
915 
916 /*
917  * Socket reference counting postulates.
918  *
919  * * Each user of socket SHOULD hold a reference count.
920  * * Each access point to socket (an hash table bucket, reference from a list,
921  *   running timer, skb in flight MUST hold a reference count.
922  * * When reference count hits 0, it means it will never increase back.
923  * * When reference count hits 0, it means that no references from
924  *   outside exist to this socket and current process on current CPU
925  *   is last user and may/should destroy this socket.
926  * * sk_free is called from any context: process, BH, IRQ. When
927  *   it is called, socket has no references from outside -> sk_free
928  *   may release descendant resources allocated by the socket, but
929  *   to the time when it is called, socket is NOT referenced by any
930  *   hash tables, lists etc.
931  * * Packets, delivered from outside (from network or from another process)
932  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
933  *   when they sit in queue. Otherwise, packets will leak to hole, when
934  *   socket is looked up by one cpu and unhasing is made by another CPU.
935  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
936  *   (leak to backlog). Packet socket does all the processing inside
937  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
938  *   use separate SMP lock, so that they are prone too.
939  */
940 
941 /* Ungrab socket and destroy it, if it was the last reference. */
942 static inline void sock_put(struct sock *sk)
943 {
944 	if (atomic_dec_and_test(&sk->sk_refcnt))
945 		sk_free(sk);
946 }
947 
948 extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb);
949 
950 /* Detach socket from process context.
951  * Announce socket dead, detach it from wait queue and inode.
952  * Note that parent inode held reference count on this struct sock,
953  * we do not release it in this function, because protocol
954  * probably wants some additional cleanups or even continuing
955  * to work with this socket (TCP).
956  */
957 static inline void sock_orphan(struct sock *sk)
958 {
959 	write_lock_bh(&sk->sk_callback_lock);
960 	sock_set_flag(sk, SOCK_DEAD);
961 	sk->sk_socket = NULL;
962 	sk->sk_sleep  = NULL;
963 	write_unlock_bh(&sk->sk_callback_lock);
964 }
965 
966 static inline void sock_graft(struct sock *sk, struct socket *parent)
967 {
968 	write_lock_bh(&sk->sk_callback_lock);
969 	sk->sk_sleep = &parent->wait;
970 	parent->sk = sk;
971 	sk->sk_socket = parent;
972 	write_unlock_bh(&sk->sk_callback_lock);
973 }
974 
975 extern int sock_i_uid(struct sock *sk);
976 extern unsigned long sock_i_ino(struct sock *sk);
977 
978 static inline struct dst_entry *
979 __sk_dst_get(struct sock *sk)
980 {
981 	return sk->sk_dst_cache;
982 }
983 
984 static inline struct dst_entry *
985 sk_dst_get(struct sock *sk)
986 {
987 	struct dst_entry *dst;
988 
989 	read_lock(&sk->sk_dst_lock);
990 	dst = sk->sk_dst_cache;
991 	if (dst)
992 		dst_hold(dst);
993 	read_unlock(&sk->sk_dst_lock);
994 	return dst;
995 }
996 
997 static inline void
998 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
999 {
1000 	struct dst_entry *old_dst;
1001 
1002 	old_dst = sk->sk_dst_cache;
1003 	sk->sk_dst_cache = dst;
1004 	dst_release(old_dst);
1005 }
1006 
1007 static inline void
1008 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1009 {
1010 	write_lock(&sk->sk_dst_lock);
1011 	__sk_dst_set(sk, dst);
1012 	write_unlock(&sk->sk_dst_lock);
1013 }
1014 
1015 static inline void
1016 __sk_dst_reset(struct sock *sk)
1017 {
1018 	struct dst_entry *old_dst;
1019 
1020 	old_dst = sk->sk_dst_cache;
1021 	sk->sk_dst_cache = NULL;
1022 	dst_release(old_dst);
1023 }
1024 
1025 static inline void
1026 sk_dst_reset(struct sock *sk)
1027 {
1028 	write_lock(&sk->sk_dst_lock);
1029 	__sk_dst_reset(sk);
1030 	write_unlock(&sk->sk_dst_lock);
1031 }
1032 
1033 extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1034 
1035 extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1036 
1037 static inline int sk_can_gso(const struct sock *sk)
1038 {
1039 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1040 }
1041 
1042 static inline void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1043 {
1044 	__sk_dst_set(sk, dst);
1045 	sk->sk_route_caps = dst->dev->features;
1046 	if (sk->sk_route_caps & NETIF_F_GSO)
1047 		sk->sk_route_caps |= NETIF_F_GSO_MASK;
1048 	if (sk_can_gso(sk)) {
1049 		if (dst->header_len)
1050 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1051 		else
1052 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1053 	}
1054 }
1055 
1056 static inline void sk_charge_skb(struct sock *sk, struct sk_buff *skb)
1057 {
1058 	sk->sk_wmem_queued   += skb->truesize;
1059 	sk->sk_forward_alloc -= skb->truesize;
1060 }
1061 
1062 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1063 				   struct sk_buff *skb, struct page *page,
1064 				   int off, int copy)
1065 {
1066 	if (skb->ip_summed == CHECKSUM_NONE) {
1067 		int err = 0;
1068 		unsigned int csum = csum_and_copy_from_user(from,
1069 						     page_address(page) + off,
1070 							    copy, 0, &err);
1071 		if (err)
1072 			return err;
1073 		skb->csum = csum_block_add(skb->csum, csum, skb->len);
1074 	} else if (copy_from_user(page_address(page) + off, from, copy))
1075 		return -EFAULT;
1076 
1077 	skb->len	     += copy;
1078 	skb->data_len	     += copy;
1079 	skb->truesize	     += copy;
1080 	sk->sk_wmem_queued   += copy;
1081 	sk->sk_forward_alloc -= copy;
1082 	return 0;
1083 }
1084 
1085 /*
1086  * 	Queue a received datagram if it will fit. Stream and sequenced
1087  *	protocols can't normally use this as they need to fit buffers in
1088  *	and play with them.
1089  *
1090  * 	Inlined as it's very short and called for pretty much every
1091  *	packet ever received.
1092  */
1093 
1094 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1095 {
1096 	sock_hold(sk);
1097 	skb->sk = sk;
1098 	skb->destructor = sock_wfree;
1099 	atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1100 }
1101 
1102 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
1103 {
1104 	skb->sk = sk;
1105 	skb->destructor = sock_rfree;
1106 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
1107 }
1108 
1109 extern void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1110 			   unsigned long expires);
1111 
1112 extern void sk_stop_timer(struct sock *sk, struct timer_list* timer);
1113 
1114 extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
1115 
1116 static inline int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb)
1117 {
1118 	/* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
1119 	   number of warnings when compiling with -W --ANK
1120 	 */
1121 	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
1122 	    (unsigned)sk->sk_rcvbuf)
1123 		return -ENOMEM;
1124 	skb_set_owner_r(skb, sk);
1125 	skb_queue_tail(&sk->sk_error_queue, skb);
1126 	if (!sock_flag(sk, SOCK_DEAD))
1127 		sk->sk_data_ready(sk, skb->len);
1128 	return 0;
1129 }
1130 
1131 /*
1132  *	Recover an error report and clear atomically
1133  */
1134 
1135 static inline int sock_error(struct sock *sk)
1136 {
1137 	int err;
1138 	if (likely(!sk->sk_err))
1139 		return 0;
1140 	err = xchg(&sk->sk_err, 0);
1141 	return -err;
1142 }
1143 
1144 static inline unsigned long sock_wspace(struct sock *sk)
1145 {
1146 	int amt = 0;
1147 
1148 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
1149 		amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
1150 		if (amt < 0)
1151 			amt = 0;
1152 	}
1153 	return amt;
1154 }
1155 
1156 static inline void sk_wake_async(struct sock *sk, int how, int band)
1157 {
1158 	if (sk->sk_socket && sk->sk_socket->fasync_list)
1159 		sock_wake_async(sk->sk_socket, how, band);
1160 }
1161 
1162 #define SOCK_MIN_SNDBUF 2048
1163 #define SOCK_MIN_RCVBUF 256
1164 
1165 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
1166 {
1167 	if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
1168 		sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued / 2);
1169 		sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
1170 	}
1171 }
1172 
1173 static inline struct sk_buff *sk_stream_alloc_pskb(struct sock *sk,
1174 						   int size, int mem,
1175 						   gfp_t gfp)
1176 {
1177 	struct sk_buff *skb;
1178 	int hdr_len;
1179 
1180 	hdr_len = SKB_DATA_ALIGN(sk->sk_prot->max_header);
1181 	skb = alloc_skb_fclone(size + hdr_len, gfp);
1182 	if (skb) {
1183 		skb->truesize += mem;
1184 		if (sk_stream_wmem_schedule(sk, skb->truesize)) {
1185 			skb_reserve(skb, hdr_len);
1186 			return skb;
1187 		}
1188 		__kfree_skb(skb);
1189 	} else {
1190 		sk->sk_prot->enter_memory_pressure();
1191 		sk_stream_moderate_sndbuf(sk);
1192 	}
1193 	return NULL;
1194 }
1195 
1196 static inline struct sk_buff *sk_stream_alloc_skb(struct sock *sk,
1197 						  int size,
1198 						  gfp_t gfp)
1199 {
1200 	return sk_stream_alloc_pskb(sk, size, 0, gfp);
1201 }
1202 
1203 static inline struct page *sk_stream_alloc_page(struct sock *sk)
1204 {
1205 	struct page *page = NULL;
1206 
1207 	page = alloc_pages(sk->sk_allocation, 0);
1208 	if (!page) {
1209 		sk->sk_prot->enter_memory_pressure();
1210 		sk_stream_moderate_sndbuf(sk);
1211 	}
1212 	return page;
1213 }
1214 
1215 #define sk_stream_for_retrans_queue(skb, sk)				\
1216 		for (skb = (sk)->sk_write_queue.next;			\
1217 		     (skb != (sk)->sk_send_head) &&			\
1218 		     (skb != (struct sk_buff *)&(sk)->sk_write_queue);	\
1219 		     skb = skb->next)
1220 
1221 /*from STCP for fast SACK Process*/
1222 #define sk_stream_for_retrans_queue_from(skb, sk)			\
1223 		for (; (skb != (sk)->sk_send_head) &&                   \
1224 		     (skb != (struct sk_buff *)&(sk)->sk_write_queue);	\
1225 		     skb = skb->next)
1226 
1227 /*
1228  *	Default write policy as shown to user space via poll/select/SIGIO
1229  */
1230 static inline int sock_writeable(const struct sock *sk)
1231 {
1232 	return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf / 2);
1233 }
1234 
1235 static inline gfp_t gfp_any(void)
1236 {
1237 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
1238 }
1239 
1240 static inline long sock_rcvtimeo(const struct sock *sk, int noblock)
1241 {
1242 	return noblock ? 0 : sk->sk_rcvtimeo;
1243 }
1244 
1245 static inline long sock_sndtimeo(const struct sock *sk, int noblock)
1246 {
1247 	return noblock ? 0 : sk->sk_sndtimeo;
1248 }
1249 
1250 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
1251 {
1252 	return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
1253 }
1254 
1255 /* Alas, with timeout socket operations are not restartable.
1256  * Compare this to poll().
1257  */
1258 static inline int sock_intr_errno(long timeo)
1259 {
1260 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
1261 }
1262 
1263 static __inline__ void
1264 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
1265 {
1266 	struct timeval stamp;
1267 
1268 	skb_get_timestamp(skb, &stamp);
1269 	if (sock_flag(sk, SOCK_RCVTSTAMP)) {
1270 		/* Race occurred between timestamp enabling and packet
1271 		   receiving.  Fill in the current time for now. */
1272 		if (stamp.tv_sec == 0)
1273 			do_gettimeofday(&stamp);
1274 		skb_set_timestamp(skb, &stamp);
1275 		put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP, sizeof(struct timeval),
1276 			 &stamp);
1277 	} else
1278 		sk->sk_stamp = stamp;
1279 }
1280 
1281 /**
1282  * sk_eat_skb - Release a skb if it is no longer needed
1283  * @sk: socket to eat this skb from
1284  * @skb: socket buffer to eat
1285  * @copied_early: flag indicating whether DMA operations copied this data early
1286  *
1287  * This routine must be called with interrupts disabled or with the socket
1288  * locked so that the sk_buff queue operation is ok.
1289 */
1290 #ifdef CONFIG_NET_DMA
1291 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1292 {
1293 	__skb_unlink(skb, &sk->sk_receive_queue);
1294 	if (!copied_early)
1295 		__kfree_skb(skb);
1296 	else
1297 		__skb_queue_tail(&sk->sk_async_wait_queue, skb);
1298 }
1299 #else
1300 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early)
1301 {
1302 	__skb_unlink(skb, &sk->sk_receive_queue);
1303 	__kfree_skb(skb);
1304 }
1305 #endif
1306 
1307 extern void sock_enable_timestamp(struct sock *sk);
1308 extern int sock_get_timestamp(struct sock *, struct timeval __user *);
1309 
1310 /*
1311  *	Enable debug/info messages
1312  */
1313 
1314 #ifdef CONFIG_NETDEBUG
1315 #define NETDEBUG(fmt, args...)	printk(fmt,##args)
1316 #define LIMIT_NETDEBUG(fmt, args...) do { if (net_ratelimit()) printk(fmt,##args); } while(0)
1317 #else
1318 #define NETDEBUG(fmt, args...)	do { } while (0)
1319 #define LIMIT_NETDEBUG(fmt, args...) do { } while(0)
1320 #endif
1321 
1322 /*
1323  * Macros for sleeping on a socket. Use them like this:
1324  *
1325  * SOCK_SLEEP_PRE(sk)
1326  * if (condition)
1327  * 	schedule();
1328  * SOCK_SLEEP_POST(sk)
1329  *
1330  * N.B. These are now obsolete and were, afaik, only ever used in DECnet
1331  * and when the last use of them in DECnet has gone, I'm intending to
1332  * remove them.
1333  */
1334 
1335 #define SOCK_SLEEP_PRE(sk) 	{ struct task_struct *tsk = current; \
1336 				DECLARE_WAITQUEUE(wait, tsk); \
1337 				tsk->state = TASK_INTERRUPTIBLE; \
1338 				add_wait_queue((sk)->sk_sleep, &wait); \
1339 				release_sock(sk);
1340 
1341 #define SOCK_SLEEP_POST(sk)	tsk->state = TASK_RUNNING; \
1342 				remove_wait_queue((sk)->sk_sleep, &wait); \
1343 				lock_sock(sk); \
1344 				}
1345 
1346 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
1347 {
1348 	if (valbool)
1349 		sock_set_flag(sk, bit);
1350 	else
1351 		sock_reset_flag(sk, bit);
1352 }
1353 
1354 extern __u32 sysctl_wmem_max;
1355 extern __u32 sysctl_rmem_max;
1356 
1357 #ifdef CONFIG_NET
1358 int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg);
1359 #else
1360 static inline int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
1361 {
1362 	return -ENODEV;
1363 }
1364 #endif
1365 
1366 extern void sk_init(void);
1367 
1368 #ifdef CONFIG_SYSCTL
1369 extern struct ctl_table core_table[];
1370 #endif
1371 
1372 extern int sysctl_optmem_max;
1373 
1374 extern __u32 sysctl_wmem_default;
1375 extern __u32 sysctl_rmem_default;
1376 
1377 #endif	/* _SOCK_H */
1378