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.
6 * Definitions for the AF_INET socket handler.
8 * Version: @(#)sock.h 1.0.4 05/13/93
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>
16 * Alan Cox : Volatiles in skbuff pointers. See
17 * skbuff comments. May be overdone,
18 * better to prove they can be removed
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
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.
43 #include <linux/kernel.h>
44 #include <linux/list.h>
45 #include <linux/timer.h>
46 #include <linux/cache.h>
47 #include <linux/module.h>
48 #include <linux/lockdep.h>
49 #include <linux/netdevice.h>
50 #include <linux/pcounter.h>
51 #include <linux/skbuff.h> /* struct sk_buff */
53 #include <linux/security.h>
55 #include <linux/filter.h>
57 #include <asm/atomic.h>
59 #include <net/checksum.h>
62 * This structure really needs to be cleaned up.
63 * Most of it is for TCP, and not used by any of
64 * the other protocols.
67 /* Define this to get the SOCK_DBG debugging facility. */
68 #define SOCK_DEBUGGING
70 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
71 printk(KERN_DEBUG msg); } while (0)
73 /* Validate arguments and do nothing */
74 static void inline int __attribute__ ((format (printf
, 2, 3)))
75 SOCK_DEBUG(struct sock
*sk
, const char *msg
, ...)
80 /* This is the per-socket lock. The spinlock provides a synchronization
81 * between user contexts and software interrupt processing, whereas the
82 * mini-semaphore synchronizes multiple users amongst themselves.
89 * We express the mutex-alike socket_lock semantics
90 * to the lock validator by explicitly managing
91 * the slock as a lock variant (in addition to
94 #ifdef CONFIG_DEBUG_LOCK_ALLOC
95 struct lockdep_map dep_map
;
104 * struct sock_common - minimal network layer representation of sockets
105 * @skc_family: network address family
106 * @skc_state: Connection state
107 * @skc_reuse: %SO_REUSEADDR setting
108 * @skc_bound_dev_if: bound device index if != 0
109 * @skc_node: main hash linkage for various protocol lookup tables
110 * @skc_bind_node: bind hash linkage for various protocol lookup tables
111 * @skc_refcnt: reference count
112 * @skc_hash: hash value used with various protocol lookup tables
113 * @skc_prot: protocol handlers inside a network family
114 * @skc_net: reference to the network namespace of this socket
116 * This is the minimal network layer representation of sockets, the header
117 * for struct sock and struct inet_timewait_sock.
120 unsigned short skc_family
;
121 volatile unsigned char skc_state
;
122 unsigned char skc_reuse
;
123 int skc_bound_dev_if
;
124 struct hlist_node skc_node
;
125 struct hlist_node skc_bind_node
;
127 unsigned int skc_hash
;
128 struct proto
*skc_prot
;
135 * struct sock - network layer representation of sockets
136 * @__sk_common: shared layout with inet_timewait_sock
137 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
138 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
139 * @sk_lock: synchronizer
140 * @sk_rcvbuf: size of receive buffer in bytes
141 * @sk_sleep: sock wait queue
142 * @sk_dst_cache: destination cache
143 * @sk_dst_lock: destination cache lock
144 * @sk_policy: flow policy
145 * @sk_rmem_alloc: receive queue bytes committed
146 * @sk_receive_queue: incoming packets
147 * @sk_wmem_alloc: transmit queue bytes committed
148 * @sk_write_queue: Packet sending queue
149 * @sk_async_wait_queue: DMA copied packets
150 * @sk_omem_alloc: "o" is "option" or "other"
151 * @sk_wmem_queued: persistent queue size
152 * @sk_forward_alloc: space allocated forward
153 * @sk_allocation: allocation mode
154 * @sk_sndbuf: size of send buffer in bytes
155 * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
156 * %SO_OOBINLINE settings
157 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
158 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
159 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
160 * @sk_gso_max_size: Maximum GSO segment size to build
161 * @sk_lingertime: %SO_LINGER l_linger setting
162 * @sk_backlog: always used with the per-socket spinlock held
163 * @sk_callback_lock: used with the callbacks in the end of this struct
164 * @sk_error_queue: rarely used
165 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
166 * IPV6_ADDRFORM for instance)
167 * @sk_err: last error
168 * @sk_err_soft: errors that don't cause failure but are the cause of a
169 * persistent failure not just 'timed out'
170 * @sk_drops: raw drops counter
171 * @sk_ack_backlog: current listen backlog
172 * @sk_max_ack_backlog: listen backlog set in listen()
173 * @sk_priority: %SO_PRIORITY setting
174 * @sk_type: socket type (%SOCK_STREAM, etc)
175 * @sk_protocol: which protocol this socket belongs in this network family
176 * @sk_peercred: %SO_PEERCRED setting
177 * @sk_rcvlowat: %SO_RCVLOWAT setting
178 * @sk_rcvtimeo: %SO_RCVTIMEO setting
179 * @sk_sndtimeo: %SO_SNDTIMEO setting
180 * @sk_filter: socket filtering instructions
181 * @sk_protinfo: private area, net family specific, when not using slab
182 * @sk_timer: sock cleanup timer
183 * @sk_stamp: time stamp of last packet received
184 * @sk_socket: Identd and reporting IO signals
185 * @sk_user_data: RPC layer private data
186 * @sk_sndmsg_page: cached page for sendmsg
187 * @sk_sndmsg_off: cached offset for sendmsg
188 * @sk_send_head: front of stuff to transmit
189 * @sk_security: used by security modules
190 * @sk_mark: generic packet mark
191 * @sk_write_pending: a write to stream socket waits to start
192 * @sk_state_change: callback to indicate change in the state of the sock
193 * @sk_data_ready: callback to indicate there is data to be processed
194 * @sk_write_space: callback to indicate there is bf sending space available
195 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
196 * @sk_backlog_rcv: callback to process the backlog
197 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
201 * Now struct inet_timewait_sock also uses sock_common, so please just
202 * don't add nothing before this first member (__sk_common) --acme
204 struct sock_common __sk_common
;
205 #define sk_family __sk_common.skc_family
206 #define sk_state __sk_common.skc_state
207 #define sk_reuse __sk_common.skc_reuse
208 #define sk_bound_dev_if __sk_common.skc_bound_dev_if
209 #define sk_node __sk_common.skc_node
210 #define sk_bind_node __sk_common.skc_bind_node
211 #define sk_refcnt __sk_common.skc_refcnt
212 #define sk_hash __sk_common.skc_hash
213 #define sk_prot __sk_common.skc_prot
214 #define sk_net __sk_common.skc_net
215 unsigned char sk_shutdown
: 2,
218 unsigned char sk_protocol
;
219 unsigned short sk_type
;
221 socket_lock_t sk_lock
;
223 * The backlog queue is special, it is always used with
224 * the per-socket spinlock held and requires low latency
225 * access. Therefore we special case it's implementation.
228 struct sk_buff
*head
;
229 struct sk_buff
*tail
;
231 wait_queue_head_t
*sk_sleep
;
232 struct dst_entry
*sk_dst_cache
;
233 struct xfrm_policy
*sk_policy
[2];
234 rwlock_t sk_dst_lock
;
235 atomic_t sk_rmem_alloc
;
236 atomic_t sk_wmem_alloc
;
237 atomic_t sk_omem_alloc
;
239 struct sk_buff_head sk_receive_queue
;
240 struct sk_buff_head sk_write_queue
;
241 struct sk_buff_head sk_async_wait_queue
;
243 int sk_forward_alloc
;
247 unsigned int sk_gso_max_size
;
249 unsigned long sk_flags
;
250 unsigned long sk_lingertime
;
251 struct sk_buff_head sk_error_queue
;
252 struct proto
*sk_prot_creator
;
253 rwlock_t sk_callback_lock
;
257 unsigned short sk_ack_backlog
;
258 unsigned short sk_max_ack_backlog
;
260 struct ucred sk_peercred
;
263 struct sk_filter
*sk_filter
;
265 struct timer_list sk_timer
;
267 struct socket
*sk_socket
;
269 struct page
*sk_sndmsg_page
;
270 struct sk_buff
*sk_send_head
;
272 int sk_write_pending
;
275 /* XXX 4 bytes hole on 64 bit */
276 void (*sk_state_change
)(struct sock
*sk
);
277 void (*sk_data_ready
)(struct sock
*sk
, int bytes
);
278 void (*sk_write_space
)(struct sock
*sk
);
279 void (*sk_error_report
)(struct sock
*sk
);
280 int (*sk_backlog_rcv
)(struct sock
*sk
,
281 struct sk_buff
*skb
);
282 void (*sk_destruct
)(struct sock
*sk
);
286 * Hashed lists helper routines
288 static inline struct sock
*__sk_head(const struct hlist_head
*head
)
290 return hlist_entry(head
->first
, struct sock
, sk_node
);
293 static inline struct sock
*sk_head(const struct hlist_head
*head
)
295 return hlist_empty(head
) ? NULL
: __sk_head(head
);
298 static inline struct sock
*sk_next(const struct sock
*sk
)
300 return sk
->sk_node
.next
?
301 hlist_entry(sk
->sk_node
.next
, struct sock
, sk_node
) : NULL
;
304 static inline int sk_unhashed(const struct sock
*sk
)
306 return hlist_unhashed(&sk
->sk_node
);
309 static inline int sk_hashed(const struct sock
*sk
)
311 return !sk_unhashed(sk
);
314 static __inline__
void sk_node_init(struct hlist_node
*node
)
319 static __inline__
void __sk_del_node(struct sock
*sk
)
321 __hlist_del(&sk
->sk_node
);
324 static __inline__
int __sk_del_node_init(struct sock
*sk
)
328 sk_node_init(&sk
->sk_node
);
334 /* Grab socket reference count. This operation is valid only
335 when sk is ALREADY grabbed f.e. it is found in hash table
336 or a list and the lookup is made under lock preventing hash table
340 static inline void sock_hold(struct sock
*sk
)
342 atomic_inc(&sk
->sk_refcnt
);
345 /* Ungrab socket in the context, which assumes that socket refcnt
346 cannot hit zero, f.e. it is true in context of any socketcall.
348 static inline void __sock_put(struct sock
*sk
)
350 atomic_dec(&sk
->sk_refcnt
);
353 static __inline__
int sk_del_node_init(struct sock
*sk
)
355 int rc
= __sk_del_node_init(sk
);
358 /* paranoid for a while -acme */
359 WARN_ON(atomic_read(&sk
->sk_refcnt
) == 1);
365 static __inline__
void __sk_add_node(struct sock
*sk
, struct hlist_head
*list
)
367 hlist_add_head(&sk
->sk_node
, list
);
370 static __inline__
void sk_add_node(struct sock
*sk
, struct hlist_head
*list
)
373 __sk_add_node(sk
, list
);
376 static __inline__
void __sk_del_bind_node(struct sock
*sk
)
378 __hlist_del(&sk
->sk_bind_node
);
381 static __inline__
void sk_add_bind_node(struct sock
*sk
,
382 struct hlist_head
*list
)
384 hlist_add_head(&sk
->sk_bind_node
, list
);
387 #define sk_for_each(__sk, node, list) \
388 hlist_for_each_entry(__sk, node, list, sk_node)
389 #define sk_for_each_from(__sk, node) \
390 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
391 hlist_for_each_entry_from(__sk, node, sk_node)
392 #define sk_for_each_continue(__sk, node) \
393 if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
394 hlist_for_each_entry_continue(__sk, node, sk_node)
395 #define sk_for_each_safe(__sk, node, tmp, list) \
396 hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
397 #define sk_for_each_bound(__sk, node, list) \
398 hlist_for_each_entry(__sk, node, list, sk_bind_node)
411 SOCK_USE_WRITE_QUEUE
, /* whether to call sk->sk_write_space in sock_wfree */
412 SOCK_DBG
, /* %SO_DEBUG setting */
413 SOCK_RCVTSTAMP
, /* %SO_TIMESTAMP setting */
414 SOCK_RCVTSTAMPNS
, /* %SO_TIMESTAMPNS setting */
415 SOCK_LOCALROUTE
, /* route locally only, %SO_DONTROUTE setting */
416 SOCK_QUEUE_SHRUNK
, /* write queue has been shrunk recently */
419 static inline void sock_copy_flags(struct sock
*nsk
, struct sock
*osk
)
421 nsk
->sk_flags
= osk
->sk_flags
;
424 static inline void sock_set_flag(struct sock
*sk
, enum sock_flags flag
)
426 __set_bit(flag
, &sk
->sk_flags
);
429 static inline void sock_reset_flag(struct sock
*sk
, enum sock_flags flag
)
431 __clear_bit(flag
, &sk
->sk_flags
);
434 static inline int sock_flag(struct sock
*sk
, enum sock_flags flag
)
436 return test_bit(flag
, &sk
->sk_flags
);
439 static inline void sk_acceptq_removed(struct sock
*sk
)
441 sk
->sk_ack_backlog
--;
444 static inline void sk_acceptq_added(struct sock
*sk
)
446 sk
->sk_ack_backlog
++;
449 static inline int sk_acceptq_is_full(struct sock
*sk
)
451 return sk
->sk_ack_backlog
> sk
->sk_max_ack_backlog
;
455 * Compute minimal free write space needed to queue new packets.
457 static inline int sk_stream_min_wspace(struct sock
*sk
)
459 return sk
->sk_wmem_queued
>> 1;
462 static inline int sk_stream_wspace(struct sock
*sk
)
464 return sk
->sk_sndbuf
- sk
->sk_wmem_queued
;
467 extern void sk_stream_write_space(struct sock
*sk
);
469 static inline int sk_stream_memory_free(struct sock
*sk
)
471 return sk
->sk_wmem_queued
< sk
->sk_sndbuf
;
474 /* The per-socket spinlock must be held here. */
475 static inline void sk_add_backlog(struct sock
*sk
, struct sk_buff
*skb
)
477 if (!sk
->sk_backlog
.tail
) {
478 sk
->sk_backlog
.head
= sk
->sk_backlog
.tail
= skb
;
480 sk
->sk_backlog
.tail
->next
= skb
;
481 sk
->sk_backlog
.tail
= skb
;
486 #define sk_wait_event(__sk, __timeo, __condition) \
488 release_sock(__sk); \
489 __rc = __condition; \
491 *(__timeo) = schedule_timeout(*(__timeo)); \
494 __rc = __condition; \
498 extern int sk_stream_wait_connect(struct sock
*sk
, long *timeo_p
);
499 extern int sk_stream_wait_memory(struct sock
*sk
, long *timeo_p
);
500 extern void sk_stream_wait_close(struct sock
*sk
, long timeo_p
);
501 extern int sk_stream_error(struct sock
*sk
, int flags
, int err
);
502 extern void sk_stream_kill_queues(struct sock
*sk
);
504 extern int sk_wait_data(struct sock
*sk
, long *timeo
);
506 struct request_sock_ops
;
507 struct timewait_sock_ops
;
508 struct inet_hashinfo
;
511 /* Networking protocol blocks we attach to sockets.
512 * socket layer -> transport layer interface
513 * transport -> network interface is defined by struct inet_proto
516 void (*close
)(struct sock
*sk
,
518 int (*connect
)(struct sock
*sk
,
519 struct sockaddr
*uaddr
,
521 int (*disconnect
)(struct sock
*sk
, int flags
);
523 struct sock
* (*accept
) (struct sock
*sk
, int flags
, int *err
);
525 int (*ioctl
)(struct sock
*sk
, int cmd
,
527 int (*init
)(struct sock
*sk
);
528 int (*destroy
)(struct sock
*sk
);
529 void (*shutdown
)(struct sock
*sk
, int how
);
530 int (*setsockopt
)(struct sock
*sk
, int level
,
531 int optname
, char __user
*optval
,
533 int (*getsockopt
)(struct sock
*sk
, int level
,
534 int optname
, char __user
*optval
,
536 int (*compat_setsockopt
)(struct sock
*sk
,
538 int optname
, char __user
*optval
,
540 int (*compat_getsockopt
)(struct sock
*sk
,
542 int optname
, char __user
*optval
,
544 int (*sendmsg
)(struct kiocb
*iocb
, struct sock
*sk
,
545 struct msghdr
*msg
, size_t len
);
546 int (*recvmsg
)(struct kiocb
*iocb
, struct sock
*sk
,
548 size_t len
, int noblock
, int flags
,
550 int (*sendpage
)(struct sock
*sk
, struct page
*page
,
551 int offset
, size_t size
, int flags
);
552 int (*bind
)(struct sock
*sk
,
553 struct sockaddr
*uaddr
, int addr_len
);
555 int (*backlog_rcv
) (struct sock
*sk
,
556 struct sk_buff
*skb
);
558 /* Keeping track of sk's, looking them up, and port selection methods. */
559 void (*hash
)(struct sock
*sk
);
560 void (*unhash
)(struct sock
*sk
);
561 int (*get_port
)(struct sock
*sk
, unsigned short snum
);
563 /* Keeping track of sockets in use */
564 #ifdef CONFIG_PROC_FS
565 unsigned int inuse_idx
;
566 struct pcounter inuse
;
569 /* Memory pressure */
570 void (*enter_memory_pressure
)(void);
571 atomic_t
*memory_allocated
; /* Current allocated memory. */
572 atomic_t
*sockets_allocated
; /* Current number of sockets. */
574 * Pressure flag: try to collapse.
575 * Technical note: it is used by multiple contexts non atomically.
576 * All the __sk_mem_schedule() is of this nature: accounting
577 * is strict, actions are advisory and have some latency.
579 int *memory_pressure
;
585 struct kmem_cache
*slab
;
586 unsigned int obj_size
;
588 atomic_t
*orphan_count
;
590 struct request_sock_ops
*rsk_prot
;
591 struct timewait_sock_ops
*twsk_prot
;
594 struct inet_hashinfo
*hashinfo
;
595 struct hlist_head
*udp_hash
;
596 struct raw_hashinfo
*raw_hash
;
599 struct module
*owner
;
603 struct list_head node
;
604 #ifdef SOCK_REFCNT_DEBUG
609 extern int proto_register(struct proto
*prot
, int alloc_slab
);
610 extern void proto_unregister(struct proto
*prot
);
612 #ifdef SOCK_REFCNT_DEBUG
613 static inline void sk_refcnt_debug_inc(struct sock
*sk
)
615 atomic_inc(&sk
->sk_prot
->socks
);
618 static inline void sk_refcnt_debug_dec(struct sock
*sk
)
620 atomic_dec(&sk
->sk_prot
->socks
);
621 printk(KERN_DEBUG
"%s socket %p released, %d are still alive\n",
622 sk
->sk_prot
->name
, sk
, atomic_read(&sk
->sk_prot
->socks
));
625 static inline void sk_refcnt_debug_release(const struct sock
*sk
)
627 if (atomic_read(&sk
->sk_refcnt
) != 1)
628 printk(KERN_DEBUG
"Destruction of the %s socket %p delayed, refcnt=%d\n",
629 sk
->sk_prot
->name
, sk
, atomic_read(&sk
->sk_refcnt
));
631 #else /* SOCK_REFCNT_DEBUG */
632 #define sk_refcnt_debug_inc(sk) do { } while (0)
633 #define sk_refcnt_debug_dec(sk) do { } while (0)
634 #define sk_refcnt_debug_release(sk) do { } while (0)
635 #endif /* SOCK_REFCNT_DEBUG */
638 #ifdef CONFIG_PROC_FS
639 # define DEFINE_PROTO_INUSE(NAME) DEFINE_PCOUNTER(NAME)
640 # define REF_PROTO_INUSE(NAME) PCOUNTER_MEMBER_INITIALIZER(NAME, .inuse)
641 /* Called with local bh disabled */
642 extern void sock_prot_inuse_add(struct proto
*prot
, int inc
);
644 static inline int sock_prot_inuse_init(struct proto
*proto
)
646 return pcounter_alloc(&proto
->inuse
);
649 extern int sock_prot_inuse_get(struct proto
*proto
);
651 static inline void sock_prot_inuse_free(struct proto
*proto
)
653 pcounter_free(&proto
->inuse
);
656 # define DEFINE_PROTO_INUSE(NAME)
657 # define REF_PROTO_INUSE(NAME)
658 static void inline sock_prot_inuse_add(struct proto
*prot
, int inc
)
661 static int inline sock_prot_inuse_init(struct proto
*proto
)
665 static void inline sock_prot_inuse_free(struct proto
*proto
)
671 /* With per-bucket locks this operation is not-atomic, so that
672 * this version is not worse.
674 static inline void __sk_prot_rehash(struct sock
*sk
)
676 sk
->sk_prot
->unhash(sk
);
677 sk
->sk_prot
->hash(sk
);
680 /* About 10 seconds */
681 #define SOCK_DESTROY_TIME (10*HZ)
683 /* Sockets 0-1023 can't be bound to unless you are superuser */
684 #define PROT_SOCK 1024
686 #define SHUTDOWN_MASK 3
687 #define RCV_SHUTDOWN 1
688 #define SEND_SHUTDOWN 2
690 #define SOCK_SNDBUF_LOCK 1
691 #define SOCK_RCVBUF_LOCK 2
692 #define SOCK_BINDADDR_LOCK 4
693 #define SOCK_BINDPORT_LOCK 8
695 /* sock_iocb: used to kick off async processing of socket ios */
697 struct list_head list
;
703 struct scm_cookie
*scm
;
704 struct msghdr
*msg
, async_msg
;
708 static inline struct sock_iocb
*kiocb_to_siocb(struct kiocb
*iocb
)
710 return (struct sock_iocb
*)iocb
->private;
713 static inline struct kiocb
*siocb_to_kiocb(struct sock_iocb
*si
)
718 struct socket_alloc
{
719 struct socket socket
;
720 struct inode vfs_inode
;
723 static inline struct socket
*SOCKET_I(struct inode
*inode
)
725 return &container_of(inode
, struct socket_alloc
, vfs_inode
)->socket
;
728 static inline struct inode
*SOCK_INODE(struct socket
*socket
)
730 return &container_of(socket
, struct socket_alloc
, socket
)->vfs_inode
;
734 * Functions for memory accounting
736 extern int __sk_mem_schedule(struct sock
*sk
, int size
, int kind
);
737 extern void __sk_mem_reclaim(struct sock
*sk
);
739 #define SK_MEM_QUANTUM ((int)PAGE_SIZE)
740 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
741 #define SK_MEM_SEND 0
742 #define SK_MEM_RECV 1
744 static inline int sk_mem_pages(int amt
)
746 return (amt
+ SK_MEM_QUANTUM
- 1) >> SK_MEM_QUANTUM_SHIFT
;
749 static inline int sk_has_account(struct sock
*sk
)
751 /* return true if protocol supports memory accounting */
752 return !!sk
->sk_prot
->memory_allocated
;
755 static inline int sk_wmem_schedule(struct sock
*sk
, int size
)
757 if (!sk_has_account(sk
))
759 return size
<= sk
->sk_forward_alloc
||
760 __sk_mem_schedule(sk
, size
, SK_MEM_SEND
);
763 static inline int sk_rmem_schedule(struct sock
*sk
, int size
)
765 if (!sk_has_account(sk
))
767 return size
<= sk
->sk_forward_alloc
||
768 __sk_mem_schedule(sk
, size
, SK_MEM_RECV
);
771 static inline void sk_mem_reclaim(struct sock
*sk
)
773 if (!sk_has_account(sk
))
775 if (sk
->sk_forward_alloc
>= SK_MEM_QUANTUM
)
776 __sk_mem_reclaim(sk
);
779 static inline void sk_mem_reclaim_partial(struct sock
*sk
)
781 if (!sk_has_account(sk
))
783 if (sk
->sk_forward_alloc
> SK_MEM_QUANTUM
)
784 __sk_mem_reclaim(sk
);
787 static inline void sk_mem_charge(struct sock
*sk
, int size
)
789 if (!sk_has_account(sk
))
791 sk
->sk_forward_alloc
-= size
;
794 static inline void sk_mem_uncharge(struct sock
*sk
, int size
)
796 if (!sk_has_account(sk
))
798 sk
->sk_forward_alloc
+= size
;
801 static inline void sk_wmem_free_skb(struct sock
*sk
, struct sk_buff
*skb
)
803 skb_truesize_check(skb
);
804 sock_set_flag(sk
, SOCK_QUEUE_SHRUNK
);
805 sk
->sk_wmem_queued
-= skb
->truesize
;
806 sk_mem_uncharge(sk
, skb
->truesize
);
810 /* Used by processes to "lock" a socket state, so that
811 * interrupts and bottom half handlers won't change it
812 * from under us. It essentially blocks any incoming
813 * packets, so that we won't get any new data or any
814 * packets that change the state of the socket.
816 * While locked, BH processing will add new packets to
817 * the backlog queue. This queue is processed by the
818 * owner of the socket lock right before it is released.
820 * Since ~2.3.5 it is also exclusive sleep lock serializing
821 * accesses from user process context.
823 #define sock_owned_by_user(sk) ((sk)->sk_lock.owned)
826 * Macro so as to not evaluate some arguments when
827 * lockdep is not enabled.
829 * Mark both the sk_lock and the sk_lock.slock as a
830 * per-address-family lock class.
832 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
834 sk->sk_lock.owned = 0; \
835 init_waitqueue_head(&sk->sk_lock.wq); \
836 spin_lock_init(&(sk)->sk_lock.slock); \
837 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
838 sizeof((sk)->sk_lock)); \
839 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
841 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
844 extern void lock_sock_nested(struct sock
*sk
, int subclass
);
846 static inline void lock_sock(struct sock
*sk
)
848 lock_sock_nested(sk
, 0);
851 extern void release_sock(struct sock
*sk
);
853 /* BH context may only use the following locking interface. */
854 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
855 #define bh_lock_sock_nested(__sk) \
856 spin_lock_nested(&((__sk)->sk_lock.slock), \
857 SINGLE_DEPTH_NESTING)
858 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
860 extern struct sock
*sk_alloc(struct net
*net
, int family
,
863 extern void sk_free(struct sock
*sk
);
864 extern void sk_release_kernel(struct sock
*sk
);
865 extern struct sock
*sk_clone(const struct sock
*sk
,
866 const gfp_t priority
);
868 extern struct sk_buff
*sock_wmalloc(struct sock
*sk
,
869 unsigned long size
, int force
,
871 extern struct sk_buff
*sock_rmalloc(struct sock
*sk
,
872 unsigned long size
, int force
,
874 extern void sock_wfree(struct sk_buff
*skb
);
875 extern void sock_rfree(struct sk_buff
*skb
);
877 extern int sock_setsockopt(struct socket
*sock
, int level
,
878 int op
, char __user
*optval
,
881 extern int sock_getsockopt(struct socket
*sock
, int level
,
882 int op
, char __user
*optval
,
884 extern struct sk_buff
*sock_alloc_send_skb(struct sock
*sk
,
888 extern void *sock_kmalloc(struct sock
*sk
, int size
,
890 extern void sock_kfree_s(struct sock
*sk
, void *mem
, int size
);
891 extern void sk_send_sigurg(struct sock
*sk
);
894 * Functions to fill in entries in struct proto_ops when a protocol
895 * does not implement a particular function.
897 extern int sock_no_bind(struct socket
*,
898 struct sockaddr
*, int);
899 extern int sock_no_connect(struct socket
*,
900 struct sockaddr
*, int, int);
901 extern int sock_no_socketpair(struct socket
*,
903 extern int sock_no_accept(struct socket
*,
904 struct socket
*, int);
905 extern int sock_no_getname(struct socket
*,
906 struct sockaddr
*, int *, int);
907 extern unsigned int sock_no_poll(struct file
*, struct socket
*,
908 struct poll_table_struct
*);
909 extern int sock_no_ioctl(struct socket
*, unsigned int,
911 extern int sock_no_listen(struct socket
*, int);
912 extern int sock_no_shutdown(struct socket
*, int);
913 extern int sock_no_getsockopt(struct socket
*, int , int,
914 char __user
*, int __user
*);
915 extern int sock_no_setsockopt(struct socket
*, int, int,
917 extern int sock_no_sendmsg(struct kiocb
*, struct socket
*,
918 struct msghdr
*, size_t);
919 extern int sock_no_recvmsg(struct kiocb
*, struct socket
*,
920 struct msghdr
*, size_t, int);
921 extern int sock_no_mmap(struct file
*file
,
923 struct vm_area_struct
*vma
);
924 extern ssize_t
sock_no_sendpage(struct socket
*sock
,
926 int offset
, size_t size
,
930 * Functions to fill in entries in struct proto_ops when a protocol
931 * uses the inet style.
933 extern int sock_common_getsockopt(struct socket
*sock
, int level
, int optname
,
934 char __user
*optval
, int __user
*optlen
);
935 extern int sock_common_recvmsg(struct kiocb
*iocb
, struct socket
*sock
,
936 struct msghdr
*msg
, size_t size
, int flags
);
937 extern int sock_common_setsockopt(struct socket
*sock
, int level
, int optname
,
938 char __user
*optval
, int optlen
);
939 extern int compat_sock_common_getsockopt(struct socket
*sock
, int level
,
940 int optname
, char __user
*optval
, int __user
*optlen
);
941 extern int compat_sock_common_setsockopt(struct socket
*sock
, int level
,
942 int optname
, char __user
*optval
, int optlen
);
944 extern void sk_common_release(struct sock
*sk
);
947 * Default socket callbacks and setup code
950 /* Initialise core socket variables */
951 extern void sock_init_data(struct socket
*sock
, struct sock
*sk
);
954 * sk_filter - run a packet through a socket filter
955 * @sk: sock associated with &sk_buff
956 * @skb: buffer to filter
957 * @needlock: set to 1 if the sock is not locked by caller.
959 * Run the filter code and then cut skb->data to correct size returned by
960 * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller
961 * than pkt_len we keep whole skb->data. This is the socket level
962 * wrapper to sk_run_filter. It returns 0 if the packet should
963 * be accepted or -EPERM if the packet should be tossed.
967 static inline int sk_filter(struct sock
*sk
, struct sk_buff
*skb
)
970 struct sk_filter
*filter
;
972 err
= security_sock_rcv_skb(sk
, skb
);
977 filter
= rcu_dereference(sk
->sk_filter
);
979 unsigned int pkt_len
= sk_run_filter(skb
, filter
->insns
,
981 err
= pkt_len
? pskb_trim(skb
, pkt_len
) : -EPERM
;
983 rcu_read_unlock_bh();
989 * sk_filter_release: Release a socket filter
991 * @fp: filter to remove
993 * Remove a filter from a socket and release its resources.
996 static inline void sk_filter_release(struct sk_filter
*fp
)
998 if (atomic_dec_and_test(&fp
->refcnt
))
1002 static inline void sk_filter_uncharge(struct sock
*sk
, struct sk_filter
*fp
)
1004 unsigned int size
= sk_filter_len(fp
);
1006 atomic_sub(size
, &sk
->sk_omem_alloc
);
1007 sk_filter_release(fp
);
1010 static inline void sk_filter_charge(struct sock
*sk
, struct sk_filter
*fp
)
1012 atomic_inc(&fp
->refcnt
);
1013 atomic_add(sk_filter_len(fp
), &sk
->sk_omem_alloc
);
1017 * Socket reference counting postulates.
1019 * * Each user of socket SHOULD hold a reference count.
1020 * * Each access point to socket (an hash table bucket, reference from a list,
1021 * running timer, skb in flight MUST hold a reference count.
1022 * * When reference count hits 0, it means it will never increase back.
1023 * * When reference count hits 0, it means that no references from
1024 * outside exist to this socket and current process on current CPU
1025 * is last user and may/should destroy this socket.
1026 * * sk_free is called from any context: process, BH, IRQ. When
1027 * it is called, socket has no references from outside -> sk_free
1028 * may release descendant resources allocated by the socket, but
1029 * to the time when it is called, socket is NOT referenced by any
1030 * hash tables, lists etc.
1031 * * Packets, delivered from outside (from network or from another process)
1032 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1033 * when they sit in queue. Otherwise, packets will leak to hole, when
1034 * socket is looked up by one cpu and unhasing is made by another CPU.
1035 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1036 * (leak to backlog). Packet socket does all the processing inside
1037 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1038 * use separate SMP lock, so that they are prone too.
1041 /* Ungrab socket and destroy it, if it was the last reference. */
1042 static inline void sock_put(struct sock
*sk
)
1044 if (atomic_dec_and_test(&sk
->sk_refcnt
))
1048 extern int sk_receive_skb(struct sock
*sk
, struct sk_buff
*skb
,
1051 /* Detach socket from process context.
1052 * Announce socket dead, detach it from wait queue and inode.
1053 * Note that parent inode held reference count on this struct sock,
1054 * we do not release it in this function, because protocol
1055 * probably wants some additional cleanups or even continuing
1056 * to work with this socket (TCP).
1058 static inline void sock_orphan(struct sock
*sk
)
1060 write_lock_bh(&sk
->sk_callback_lock
);
1061 sock_set_flag(sk
, SOCK_DEAD
);
1062 sk
->sk_socket
= NULL
;
1063 sk
->sk_sleep
= NULL
;
1064 write_unlock_bh(&sk
->sk_callback_lock
);
1067 static inline void sock_graft(struct sock
*sk
, struct socket
*parent
)
1069 write_lock_bh(&sk
->sk_callback_lock
);
1070 sk
->sk_sleep
= &parent
->wait
;
1072 sk
->sk_socket
= parent
;
1073 security_sock_graft(sk
, parent
);
1074 write_unlock_bh(&sk
->sk_callback_lock
);
1077 extern int sock_i_uid(struct sock
*sk
);
1078 extern unsigned long sock_i_ino(struct sock
*sk
);
1080 static inline struct dst_entry
*
1081 __sk_dst_get(struct sock
*sk
)
1083 return sk
->sk_dst_cache
;
1086 static inline struct dst_entry
*
1087 sk_dst_get(struct sock
*sk
)
1089 struct dst_entry
*dst
;
1091 read_lock(&sk
->sk_dst_lock
);
1092 dst
= sk
->sk_dst_cache
;
1095 read_unlock(&sk
->sk_dst_lock
);
1100 __sk_dst_set(struct sock
*sk
, struct dst_entry
*dst
)
1102 struct dst_entry
*old_dst
;
1104 old_dst
= sk
->sk_dst_cache
;
1105 sk
->sk_dst_cache
= dst
;
1106 dst_release(old_dst
);
1110 sk_dst_set(struct sock
*sk
, struct dst_entry
*dst
)
1112 write_lock(&sk
->sk_dst_lock
);
1113 __sk_dst_set(sk
, dst
);
1114 write_unlock(&sk
->sk_dst_lock
);
1118 __sk_dst_reset(struct sock
*sk
)
1120 struct dst_entry
*old_dst
;
1122 old_dst
= sk
->sk_dst_cache
;
1123 sk
->sk_dst_cache
= NULL
;
1124 dst_release(old_dst
);
1128 sk_dst_reset(struct sock
*sk
)
1130 write_lock(&sk
->sk_dst_lock
);
1132 write_unlock(&sk
->sk_dst_lock
);
1135 extern struct dst_entry
*__sk_dst_check(struct sock
*sk
, u32 cookie
);
1137 extern struct dst_entry
*sk_dst_check(struct sock
*sk
, u32 cookie
);
1139 static inline int sk_can_gso(const struct sock
*sk
)
1141 return net_gso_ok(sk
->sk_route_caps
, sk
->sk_gso_type
);
1144 extern void sk_setup_caps(struct sock
*sk
, struct dst_entry
*dst
);
1146 static inline int skb_copy_to_page(struct sock
*sk
, char __user
*from
,
1147 struct sk_buff
*skb
, struct page
*page
,
1150 if (skb
->ip_summed
== CHECKSUM_NONE
) {
1152 __wsum csum
= csum_and_copy_from_user(from
,
1153 page_address(page
) + off
,
1157 skb
->csum
= csum_block_add(skb
->csum
, csum
, skb
->len
);
1158 } else if (copy_from_user(page_address(page
) + off
, from
, copy
))
1162 skb
->data_len
+= copy
;
1163 skb
->truesize
+= copy
;
1164 sk
->sk_wmem_queued
+= copy
;
1165 sk_mem_charge(sk
, copy
);
1170 * Queue a received datagram if it will fit. Stream and sequenced
1171 * protocols can't normally use this as they need to fit buffers in
1172 * and play with them.
1174 * Inlined as it's very short and called for pretty much every
1175 * packet ever received.
1178 static inline void skb_set_owner_w(struct sk_buff
*skb
, struct sock
*sk
)
1182 skb
->destructor
= sock_wfree
;
1183 atomic_add(skb
->truesize
, &sk
->sk_wmem_alloc
);
1186 static inline void skb_set_owner_r(struct sk_buff
*skb
, struct sock
*sk
)
1189 skb
->destructor
= sock_rfree
;
1190 atomic_add(skb
->truesize
, &sk
->sk_rmem_alloc
);
1191 sk_mem_charge(sk
, skb
->truesize
);
1194 extern void sk_reset_timer(struct sock
*sk
, struct timer_list
* timer
,
1195 unsigned long expires
);
1197 extern void sk_stop_timer(struct sock
*sk
, struct timer_list
* timer
);
1199 extern int sock_queue_rcv_skb(struct sock
*sk
, struct sk_buff
*skb
);
1201 static inline int sock_queue_err_skb(struct sock
*sk
, struct sk_buff
*skb
)
1203 /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces
1204 number of warnings when compiling with -W --ANK
1206 if (atomic_read(&sk
->sk_rmem_alloc
) + skb
->truesize
>=
1207 (unsigned)sk
->sk_rcvbuf
)
1209 skb_set_owner_r(skb
, sk
);
1210 skb_queue_tail(&sk
->sk_error_queue
, skb
);
1211 if (!sock_flag(sk
, SOCK_DEAD
))
1212 sk
->sk_data_ready(sk
, skb
->len
);
1217 * Recover an error report and clear atomically
1220 static inline int sock_error(struct sock
*sk
)
1223 if (likely(!sk
->sk_err
))
1225 err
= xchg(&sk
->sk_err
, 0);
1229 static inline unsigned long sock_wspace(struct sock
*sk
)
1233 if (!(sk
->sk_shutdown
& SEND_SHUTDOWN
)) {
1234 amt
= sk
->sk_sndbuf
- atomic_read(&sk
->sk_wmem_alloc
);
1241 static inline void sk_wake_async(struct sock
*sk
, int how
, int band
)
1243 if (sk
->sk_socket
&& sk
->sk_socket
->fasync_list
)
1244 sock_wake_async(sk
->sk_socket
, how
, band
);
1247 #define SOCK_MIN_SNDBUF 2048
1248 #define SOCK_MIN_RCVBUF 256
1250 static inline void sk_stream_moderate_sndbuf(struct sock
*sk
)
1252 if (!(sk
->sk_userlocks
& SOCK_SNDBUF_LOCK
)) {
1253 sk
->sk_sndbuf
= min(sk
->sk_sndbuf
, sk
->sk_wmem_queued
>> 1);
1254 sk
->sk_sndbuf
= max(sk
->sk_sndbuf
, SOCK_MIN_SNDBUF
);
1258 struct sk_buff
*sk_stream_alloc_skb(struct sock
*sk
, int size
, gfp_t gfp
);
1260 static inline struct page
*sk_stream_alloc_page(struct sock
*sk
)
1262 struct page
*page
= NULL
;
1264 page
= alloc_pages(sk
->sk_allocation
, 0);
1266 sk
->sk_prot
->enter_memory_pressure();
1267 sk_stream_moderate_sndbuf(sk
);
1273 * Default write policy as shown to user space via poll/select/SIGIO
1275 static inline int sock_writeable(const struct sock
*sk
)
1277 return atomic_read(&sk
->sk_wmem_alloc
) < (sk
->sk_sndbuf
>> 1);
1280 static inline gfp_t
gfp_any(void)
1282 return in_atomic() ? GFP_ATOMIC
: GFP_KERNEL
;
1285 static inline long sock_rcvtimeo(const struct sock
*sk
, int noblock
)
1287 return noblock
? 0 : sk
->sk_rcvtimeo
;
1290 static inline long sock_sndtimeo(const struct sock
*sk
, int noblock
)
1292 return noblock
? 0 : sk
->sk_sndtimeo
;
1295 static inline int sock_rcvlowat(const struct sock
*sk
, int waitall
, int len
)
1297 return (waitall
? len
: min_t(int, sk
->sk_rcvlowat
, len
)) ? : 1;
1300 /* Alas, with timeout socket operations are not restartable.
1301 * Compare this to poll().
1303 static inline int sock_intr_errno(long timeo
)
1305 return timeo
== MAX_SCHEDULE_TIMEOUT
? -ERESTARTSYS
: -EINTR
;
1308 extern void __sock_recv_timestamp(struct msghdr
*msg
, struct sock
*sk
,
1309 struct sk_buff
*skb
);
1311 static __inline__
void
1312 sock_recv_timestamp(struct msghdr
*msg
, struct sock
*sk
, struct sk_buff
*skb
)
1314 ktime_t kt
= skb
->tstamp
;
1316 if (sock_flag(sk
, SOCK_RCVTSTAMP
))
1317 __sock_recv_timestamp(msg
, sk
, skb
);
1323 * sk_eat_skb - Release a skb if it is no longer needed
1324 * @sk: socket to eat this skb from
1325 * @skb: socket buffer to eat
1326 * @copied_early: flag indicating whether DMA operations copied this data early
1328 * This routine must be called with interrupts disabled or with the socket
1329 * locked so that the sk_buff queue operation is ok.
1331 #ifdef CONFIG_NET_DMA
1332 static inline void sk_eat_skb(struct sock
*sk
, struct sk_buff
*skb
, int copied_early
)
1334 __skb_unlink(skb
, &sk
->sk_receive_queue
);
1338 __skb_queue_tail(&sk
->sk_async_wait_queue
, skb
);
1341 static inline void sk_eat_skb(struct sock
*sk
, struct sk_buff
*skb
, int copied_early
)
1343 __skb_unlink(skb
, &sk
->sk_receive_queue
);
1349 struct net
*sock_net(const struct sock
*sk
)
1351 #ifdef CONFIG_NET_NS
1359 void sock_net_set(struct sock
*sk
, struct net
*net
)
1361 #ifdef CONFIG_NET_NS
1367 * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
1368 * They should not hold a referrence to a namespace in order to allow
1370 * Sockets after sk_change_net should be released using sk_release_kernel
1372 static inline void sk_change_net(struct sock
*sk
, struct net
*net
)
1374 put_net(sock_net(sk
));
1375 sock_net_set(sk
, net
);
1378 extern void sock_enable_timestamp(struct sock
*sk
);
1379 extern int sock_get_timestamp(struct sock
*, struct timeval __user
*);
1380 extern int sock_get_timestampns(struct sock
*, struct timespec __user
*);
1383 * Enable debug/info messages
1385 extern int net_msg_warn
;
1386 #define NETDEBUG(fmt, args...) \
1387 do { if (net_msg_warn) printk(fmt,##args); } while (0)
1389 #define LIMIT_NETDEBUG(fmt, args...) \
1390 do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
1393 * Macros for sleeping on a socket. Use them like this:
1395 * SOCK_SLEEP_PRE(sk)
1398 * SOCK_SLEEP_POST(sk)
1400 * N.B. These are now obsolete and were, afaik, only ever used in DECnet
1401 * and when the last use of them in DECnet has gone, I'm intending to
1405 #define SOCK_SLEEP_PRE(sk) { struct task_struct *tsk = current; \
1406 DECLARE_WAITQUEUE(wait, tsk); \
1407 tsk->state = TASK_INTERRUPTIBLE; \
1408 add_wait_queue((sk)->sk_sleep, &wait); \
1411 #define SOCK_SLEEP_POST(sk) tsk->state = TASK_RUNNING; \
1412 remove_wait_queue((sk)->sk_sleep, &wait); \
1416 extern __u32 sysctl_wmem_max
;
1417 extern __u32 sysctl_rmem_max
;
1419 extern void sk_init(void);
1421 extern int sysctl_optmem_max
;
1423 extern __u32 sysctl_wmem_default
;
1424 extern __u32 sysctl_rmem_default
;
1426 #endif /* _SOCK_H */