sock.h 62.4 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1
2
3
4
5
6
7
8
9
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Definitions for the AF_INET socket handler.
 *
 * Version:	@(#)sock.h	1.0.4	05/13/93
 *
10
 * Authors:	Ross Biro
Linus Torvalds's avatar
Linus Torvalds committed
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
 *		Florian La Roche <flla@stud.uni-sb.de>
 *
 * Fixes:
 *		Alan Cox	:	Volatiles in skbuff pointers. See
 *					skbuff comments. May be overdone,
 *					better to prove they can be removed
 *					than the reverse.
 *		Alan Cox	:	Added a zapped field for tcp to note
 *					a socket is reset and must stay shut up
 *		Alan Cox	:	New fields for options
 *	Pauline Middelink	:	identd support
 *		Alan Cox	:	Eliminate low level recv/recvfrom
 *		David S. Miller	:	New socket lookup architecture.
 *              Steve Whitehouse:       Default routines for sock_ops
 *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
 *              			protinfo be just a void pointer, as the
 *              			protocol specific parts were moved to
 *              			respective headers and ipv4/v6, etc now
 *              			use private slabcaches for its socks
 *              Pedro Hortas	:	New flags field for socket options
 *
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 */
#ifndef _SOCK_H
#define _SOCK_H

43
#include <linux/hardirq.h>
44
#include <linux/kernel.h>
Linus Torvalds's avatar
Linus Torvalds committed
45
#include <linux/list.h>
46
#include <linux/list_nulls.h>
Linus Torvalds's avatar
Linus Torvalds committed
47
48
#include <linux/timer.h>
#include <linux/cache.h>
49
#include <linux/bitops.h>
50
#include <linux/lockdep.h>
Linus Torvalds's avatar
Linus Torvalds committed
51
52
#include <linux/netdevice.h>
#include <linux/skbuff.h>	/* struct sk_buff */
Al Viro's avatar
Al Viro committed
53
#include <linux/mm.h>
Linus Torvalds's avatar
Linus Torvalds committed
54
#include <linux/security.h>
55
#include <linux/slab.h>
56
#include <linux/uaccess.h>
57
#include <linux/memcontrol.h>
Glauber Costa's avatar
Glauber Costa committed
58
#include <linux/res_counter.h>
59
#include <linux/static_key.h>
Al Viro's avatar
Al Viro committed
60
61
#include <linux/aio.h>
#include <linux/sched.h>
Linus Torvalds's avatar
Linus Torvalds committed
62
63

#include <linux/filter.h>
64
#include <linux/rculist_nulls.h>
65
#include <linux/poll.h>
Linus Torvalds's avatar
Linus Torvalds committed
66

67
#include <linux/atomic.h>
Linus Torvalds's avatar
Linus Torvalds committed
68
69
70
#include <net/dst.h>
#include <net/checksum.h>

71
72
struct cgroup;
struct cgroup_subsys;
73
#ifdef CONFIG_NET
74
75
int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg);
76
77
#else
static inline
78
int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
79
80
81
82
{
	return 0;
}
static inline
83
void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
84
85
86
{
}
#endif
Linus Torvalds's avatar
Linus Torvalds committed
87
88
89
90
91
92
93
94
95
96
97
98
/*
 * This structure really needs to be cleaned up.
 * Most of it is for TCP, and not used by any of
 * the other protocols.
 */

/* Define this to get the SOCK_DBG debugging facility. */
#define SOCK_DEBUGGING
#ifdef SOCK_DEBUGGING
#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
					printk(KERN_DEBUG msg); } while (0)
#else
99
/* Validate arguments and do nothing */
100
static inline __printf(2, 3)
Eric Dumazet's avatar
Eric Dumazet committed
101
void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
102
103
{
}
Linus Torvalds's avatar
Linus Torvalds committed
104
105
106
107
108
109
110
111
#endif

/* This is the per-socket lock.  The spinlock provides a synchronization
 * between user contexts and software interrupt processing, whereas the
 * mini-semaphore synchronizes multiple users amongst themselves.
 */
typedef struct {
	spinlock_t		slock;
112
	int			owned;
Linus Torvalds's avatar
Linus Torvalds committed
113
	wait_queue_head_t	wq;
114
115
116
117
118
119
120
121
122
	/*
	 * We express the mutex-alike socket_lock semantics
	 * to the lock validator by explicitly managing
	 * the slock as a lock variant (in addition to
	 * the slock itself):
	 */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map dep_map;
#endif
Linus Torvalds's avatar
Linus Torvalds committed
123
124
125
} socket_lock_t;

struct sock;
126
struct proto;
127
struct net;
Linus Torvalds's avatar
Linus Torvalds committed
128

129
130
131
typedef __u32 __bitwise __portpair;
typedef __u64 __bitwise __addrpair;

Linus Torvalds's avatar
Linus Torvalds committed
132
/**
133
 *	struct sock_common - minimal network layer representation of sockets
134
135
 *	@skc_daddr: Foreign IPv4 addr
 *	@skc_rcv_saddr: Bound local IPv4 addr
Eric Dumazet's avatar
Eric Dumazet committed
136
 *	@skc_hash: hash value used with various protocol lookup tables
137
 *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
138
139
 *	@skc_dport: placeholder for inet_dport/tw_dport
 *	@skc_num: placeholder for inet_num/tw_num
140
141
142
 *	@skc_family: network address family
 *	@skc_state: Connection state
 *	@skc_reuse: %SO_REUSEADDR setting
Tom Herbert's avatar
Tom Herbert committed
143
 *	@skc_reuseport: %SO_REUSEPORT setting
144
145
 *	@skc_bound_dev_if: bound device index if != 0
 *	@skc_bind_node: bind hash linkage for various protocol lookup tables
146
 *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
147
 *	@skc_prot: protocol handlers inside a network family
148
 *	@skc_net: reference to the network namespace of this socket
149
150
151
152
 *	@skc_node: main hash linkage for various protocol lookup tables
 *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
 *	@skc_tx_queue_mapping: tx queue number for this connection
 *	@skc_refcnt: reference count
153
154
 *
 *	This is the minimal network layer representation of sockets, the header
155
156
 *	for struct sock and struct inet_timewait_sock.
 */
Linus Torvalds's avatar
Linus Torvalds committed
157
struct sock_common {
158
159
	/* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
	 * address on 64bit arches : cf INET_MATCH() and INET_TW_MATCH()
Eric Dumazet's avatar
Eric Dumazet committed
160
	 */
161
	union {
162
		__addrpair	skc_addrpair;
163
164
165
166
167
		struct {
			__be32	skc_daddr;
			__be32	skc_rcv_saddr;
		};
	};
168
169
170
171
	union  {
		unsigned int	skc_hash;
		__u16		skc_u16hashes[2];
	};
172
173
	/* skc_dport && skc_num must be grouped as well */
	union {
174
		__portpair	skc_portpair;
175
176
177
178
179
180
		struct {
			__be16	skc_dport;
			__u16	skc_num;
		};
	};

Eric Dumazet's avatar
Eric Dumazet committed
181
182
	unsigned short		skc_family;
	volatile unsigned char	skc_state;
Tom Herbert's avatar
Tom Herbert committed
183
184
	unsigned char		skc_reuse:4;
	unsigned char		skc_reuseport:4;
Eric Dumazet's avatar
Eric Dumazet committed
185
	int			skc_bound_dev_if;
186
187
188
189
	union {
		struct hlist_node	skc_bind_node;
		struct hlist_nulls_node skc_portaddr_node;
	};
190
	struct proto		*skc_prot;
191
#ifdef CONFIG_NET_NS
192
	struct net	 	*skc_net;
193
#endif
194
195
196
197
	/*
	 * fields between dontcopy_begin/dontcopy_end
	 * are not copied in sock_copy()
	 */
198
	/* private: */
199
	int			skc_dontcopy_begin[0];
200
	/* public: */
201
202
203
204
205
206
	union {
		struct hlist_node	skc_node;
		struct hlist_nulls_node skc_nulls_node;
	};
	int			skc_tx_queue_mapping;
	atomic_t		skc_refcnt;
207
	/* private: */
208
	int                     skc_dontcopy_end[0];
209
	/* public: */
Linus Torvalds's avatar
Linus Torvalds committed
210
211
};

Glauber Costa's avatar
Glauber Costa committed
212
struct cg_proto;
Linus Torvalds's avatar
Linus Torvalds committed
213
214
/**
  *	struct sock - network layer representation of sockets
215
  *	@__sk_common: shared layout with inet_timewait_sock
216
217
218
219
  *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
  *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
  *	@sk_lock:	synchronizer
  *	@sk_rcvbuf: size of receive buffer in bytes
220
  *	@sk_wq: sock wait queue and async head
Eric Dumazet's avatar
Eric Dumazet committed
221
  *	@sk_rx_dst: receive input route used by early tcp demux
222
223
224
225
226
227
  *	@sk_dst_cache: destination cache
  *	@sk_dst_lock: destination cache lock
  *	@sk_policy: flow policy
  *	@sk_receive_queue: incoming packets
  *	@sk_wmem_alloc: transmit queue bytes committed
  *	@sk_write_queue: Packet sending queue
228
  *	@sk_async_wait_queue: DMA copied packets
229
230
231
232
233
  *	@sk_omem_alloc: "o" is "option" or "other"
  *	@sk_wmem_queued: persistent queue size
  *	@sk_forward_alloc: space allocated forward
  *	@sk_allocation: allocation mode
  *	@sk_sndbuf: size of send buffer in bytes
Wang Chen's avatar
Wang Chen committed
234
  *	@sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
235
  *		   %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
236
  *	@sk_no_check: %SO_NO_CHECK setting, whether or not checkup packets
237
  *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
Eric Dumazet's avatar
Eric Dumazet committed
238
  *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
239
  *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
240
  *	@sk_gso_max_size: Maximum GSO segment size to build
241
  *	@sk_gso_max_segs: Maximum number of GSO segments
242
243
244
245
  *	@sk_lingertime: %SO_LINGER l_linger setting
  *	@sk_backlog: always used with the per-socket spinlock held
  *	@sk_callback_lock: used with the callbacks in the end of this struct
  *	@sk_error_queue: rarely used
Wang Chen's avatar
Wang Chen committed
246
247
  *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
  *			  IPV6_ADDRFORM for instance)
248
  *	@sk_err: last error
Wang Chen's avatar
Wang Chen committed
249
250
  *	@sk_err_soft: errors that don't cause failure but are the cause of a
  *		      persistent failure not just 'timed out'
Eric Dumazet's avatar
Eric Dumazet committed
251
  *	@sk_drops: raw/udp drops counter
252
253
254
  *	@sk_ack_backlog: current listen backlog
  *	@sk_max_ack_backlog: listen backlog set in listen()
  *	@sk_priority: %SO_PRIORITY setting
255
  *	@sk_cgrp_prioidx: socket group's priority map index
256
257
  *	@sk_type: socket type (%SOCK_STREAM, etc)
  *	@sk_protocol: which protocol this socket belongs in this network family
258
259
  *	@sk_peer_pid: &struct pid for this socket's peer
  *	@sk_peer_cred: %SO_PEERCRED setting
260
261
262
  *	@sk_rcvlowat: %SO_RCVLOWAT setting
  *	@sk_rcvtimeo: %SO_RCVTIMEO setting
  *	@sk_sndtimeo: %SO_SNDTIMEO setting
263
  *	@sk_rxhash: flow hash received from netif layer
264
265
266
267
268
269
  *	@sk_filter: socket filtering instructions
  *	@sk_protinfo: private area, net family specific, when not using slab
  *	@sk_timer: sock cleanup timer
  *	@sk_stamp: time stamp of last packet received
  *	@sk_socket: Identd and reporting IO signals
  *	@sk_user_data: RPC layer private data
270
  *	@sk_frag: cached page frag
271
  *	@sk_peek_off: current peek_offset value
272
  *	@sk_send_head: front of stuff to transmit
273
  *	@sk_security: used by security modules
274
  *	@sk_mark: generic packet mark
275
  *	@sk_classid: this socket's cgroup classid
Glauber Costa's avatar
Glauber Costa committed
276
  *	@sk_cgrp: this socket's cgroup-specific proto data
277
278
279
280
281
282
283
  *	@sk_write_pending: a write to stream socket waits to start
  *	@sk_state_change: callback to indicate change in the state of the sock
  *	@sk_data_ready: callback to indicate there is data to be processed
  *	@sk_write_space: callback to indicate there is bf sending space available
  *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
  *	@sk_backlog_rcv: callback to process the backlog
  *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
Linus Torvalds's avatar
Linus Torvalds committed
284
285
286
 */
struct sock {
	/*
287
	 * Now struct inet_timewait_sock also uses sock_common, so please just
Linus Torvalds's avatar
Linus Torvalds committed
288
289
290
	 * don't add nothing before this first member (__sk_common) --acme
	 */
	struct sock_common	__sk_common;
Eric Dumazet's avatar
Eric Dumazet committed
291
292
293
#define sk_node			__sk_common.skc_node
#define sk_nulls_node		__sk_common.skc_nulls_node
#define sk_refcnt		__sk_common.skc_refcnt
294
#define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
Eric Dumazet's avatar
Eric Dumazet committed
295

296
297
#define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
#define sk_dontcopy_end		__sk_common.skc_dontcopy_end
Eric Dumazet's avatar
Eric Dumazet committed
298
#define sk_hash			__sk_common.skc_hash
Linus Torvalds's avatar
Linus Torvalds committed
299
300
301
#define sk_family		__sk_common.skc_family
#define sk_state		__sk_common.skc_state
#define sk_reuse		__sk_common.skc_reuse
Tom Herbert's avatar
Tom Herbert committed
302
#define sk_reuseport		__sk_common.skc_reuseport
Linus Torvalds's avatar
Linus Torvalds committed
303
304
#define sk_bound_dev_if		__sk_common.skc_bound_dev_if
#define sk_bind_node		__sk_common.skc_bind_node
305
#define sk_prot			__sk_common.skc_prot
306
#define sk_net			__sk_common.skc_net
Linus Torvalds's avatar
Linus Torvalds committed
307
	socket_lock_t		sk_lock;
Eric Dumazet's avatar
Eric Dumazet committed
308
	struct sk_buff_head	sk_receive_queue;
309
310
311
312
	/*
	 * The backlog queue is special, it is always used with
	 * the per-socket spinlock held and requires low latency
	 * access. Therefore we special case it's implementation.
Eric Dumazet's avatar
Eric Dumazet committed
313
314
315
	 * Note : rmem_alloc is in this structure to fill a hole
	 * on 64bit arches, not because its logically part of
	 * backlog.
316
317
	 */
	struct {
Eric Dumazet's avatar
Eric Dumazet committed
318
319
320
321
		atomic_t	rmem_alloc;
		int		len;
		struct sk_buff	*head;
		struct sk_buff	*tail;
322
	} sk_backlog;
Eric Dumazet's avatar
Eric Dumazet committed
323
324
325
326
327
328
329
330
331
#define sk_rmem_alloc sk_backlog.rmem_alloc
	int			sk_forward_alloc;
#ifdef CONFIG_RPS
	__u32			sk_rxhash;
#endif
	atomic_t		sk_drops;
	int			sk_rcvbuf;

	struct sk_filter __rcu	*sk_filter;
332
	struct socket_wq __rcu	*sk_wq;
Eric Dumazet's avatar
Eric Dumazet committed
333
334
335
336
337

#ifdef CONFIG_NET_DMA
	struct sk_buff_head	sk_async_wait_queue;
#endif

338
#ifdef CONFIG_XFRM
Linus Torvalds's avatar
Linus Torvalds committed
339
	struct xfrm_policy	*sk_policy[2];
340
#endif
Eric Dumazet's avatar
Eric Dumazet committed
341
	unsigned long 		sk_flags;
Eric Dumazet's avatar
Eric Dumazet committed
342
	struct dst_entry	*sk_rx_dst;
343
	struct dst_entry __rcu	*sk_dst_cache;
Eric Dumazet's avatar
Eric Dumazet committed
344
	spinlock_t		sk_dst_lock;
Linus Torvalds's avatar
Linus Torvalds committed
345
346
	atomic_t		sk_wmem_alloc;
	atomic_t		sk_omem_alloc;
347
	int			sk_sndbuf;
Linus Torvalds's avatar
Linus Torvalds committed
348
	struct sk_buff_head	sk_write_queue;
Eric Dumazet's avatar
Eric Dumazet committed
349
350
351
352
353
354
355
	kmemcheck_bitfield_begin(flags);
	unsigned int		sk_shutdown  : 2,
				sk_no_check  : 2,
				sk_userlocks : 4,
				sk_protocol  : 8,
				sk_type      : 16;
	kmemcheck_bitfield_end(flags);
Linus Torvalds's avatar
Linus Torvalds committed
356
	int			sk_wmem_queued;
Al Viro's avatar
Al Viro committed
357
	gfp_t			sk_allocation;
358
359
	netdev_features_t	sk_route_caps;
	netdev_features_t	sk_route_nocaps;
360
	int			sk_gso_type;
361
	unsigned int		sk_gso_max_size;
362
	u16			sk_gso_max_segs;
363
	int			sk_rcvlowat;
Linus Torvalds's avatar
Linus Torvalds committed
364
365
	unsigned long	        sk_lingertime;
	struct sk_buff_head	sk_error_queue;
366
	struct proto		*sk_prot_creator;
Linus Torvalds's avatar
Linus Torvalds committed
367
368
369
370
371
372
	rwlock_t		sk_callback_lock;
	int			sk_err,
				sk_err_soft;
	unsigned short		sk_ack_backlog;
	unsigned short		sk_max_ack_backlog;
	__u32			sk_priority;
373
#if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
374
375
	__u32			sk_cgrp_prioidx;
#endif
376
377
	struct pid		*sk_peer_pid;
	const struct cred	*sk_peer_cred;
Linus Torvalds's avatar
Linus Torvalds committed
378
379
380
381
	long			sk_rcvtimeo;
	long			sk_sndtimeo;
	void			*sk_protinfo;
	struct timer_list	sk_timer;
382
	ktime_t			sk_stamp;
Linus Torvalds's avatar
Linus Torvalds committed
383
384
	struct socket		*sk_socket;
	void			*sk_user_data;
385
	struct page_frag	sk_frag;
Linus Torvalds's avatar
Linus Torvalds committed
386
	struct sk_buff		*sk_send_head;
387
	__s32			sk_peek_off;
Linus Torvalds's avatar
Linus Torvalds committed
388
	int			sk_write_pending;
Alexey Dobriyan's avatar
Alexey Dobriyan committed
389
#ifdef CONFIG_SECURITY
Linus Torvalds's avatar
Linus Torvalds committed
390
	void			*sk_security;
Alexey Dobriyan's avatar
Alexey Dobriyan committed
391
#endif
392
	__u32			sk_mark;
393
	u32			sk_classid;
Glauber Costa's avatar
Glauber Costa committed
394
	struct cg_proto		*sk_cgrp;
Linus Torvalds's avatar
Linus Torvalds committed
395
396
397
398
	void			(*sk_state_change)(struct sock *sk);
	void			(*sk_data_ready)(struct sock *sk, int bytes);
	void			(*sk_write_space)(struct sock *sk);
	void			(*sk_error_report)(struct sock *sk);
Eric Dumazet's avatar
Eric Dumazet committed
399
400
	int			(*sk_backlog_rcv)(struct sock *sk,
						  struct sk_buff *skb);
Linus Torvalds's avatar
Linus Torvalds committed
401
402
403
	void                    (*sk_destruct)(struct sock *sk);
};

404
405
406
407
408
409
410
411
412
413
414
/*
 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
 * on a socket means that the socket will reuse everybody else's port
 * without looking at the other's sk_reuse value.
 */

#define SK_NO_REUSE	0
#define SK_CAN_REUSE	1
#define SK_FORCE_REUSE	2

415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
static inline int sk_peek_offset(struct sock *sk, int flags)
{
	if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
		return sk->sk_peek_off;
	else
		return 0;
}

static inline void sk_peek_offset_bwd(struct sock *sk, int val)
{
	if (sk->sk_peek_off >= 0) {
		if (sk->sk_peek_off >= val)
			sk->sk_peek_off -= val;
		else
			sk->sk_peek_off = 0;
	}
}

static inline void sk_peek_offset_fwd(struct sock *sk, int val)
{
	if (sk->sk_peek_off >= 0)
		sk->sk_peek_off += val;
}

Linus Torvalds's avatar
Linus Torvalds committed
439
440
441
/*
 * Hashed lists helper routines
 */
Li Zefan's avatar
Li Zefan committed
442
443
444
445
446
static inline struct sock *sk_entry(const struct hlist_node *node)
{
	return hlist_entry(node, struct sock, sk_node);
}

447
static inline struct sock *__sk_head(const struct hlist_head *head)
Linus Torvalds's avatar
Linus Torvalds committed
448
449
450
451
{
	return hlist_entry(head->first, struct sock, sk_node);
}

452
static inline struct sock *sk_head(const struct hlist_head *head)
Linus Torvalds's avatar
Linus Torvalds committed
453
454
455
456
{
	return hlist_empty(head) ? NULL : __sk_head(head);
}

457
458
459
460
461
462
463
464
465
466
static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
{
	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
}

static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
{
	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
}

467
static inline struct sock *sk_next(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
468
469
470
471
472
{
	return sk->sk_node.next ?
		hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
}

473
474
475
476
477
478
479
480
static inline struct sock *sk_nulls_next(const struct sock *sk)
{
	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
		hlist_nulls_entry(sk->sk_nulls_node.next,
				  struct sock, sk_nulls_node) :
		NULL;
}

Eric Dumazet's avatar
Eric Dumazet committed
481
static inline bool sk_unhashed(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
482
483
484
485
{
	return hlist_unhashed(&sk->sk_node);
}

Eric Dumazet's avatar
Eric Dumazet committed
486
static inline bool sk_hashed(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
487
{
Akinobu Mita's avatar
Akinobu Mita committed
488
	return !sk_unhashed(sk);
Linus Torvalds's avatar
Linus Torvalds committed
489
490
}

Eric Dumazet's avatar
Eric Dumazet committed
491
static inline void sk_node_init(struct hlist_node *node)
Linus Torvalds's avatar
Linus Torvalds committed
492
493
494
495
{
	node->pprev = NULL;
}

Eric Dumazet's avatar
Eric Dumazet committed
496
static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
497
498
499
500
{
	node->pprev = NULL;
}

Eric Dumazet's avatar
Eric Dumazet committed
501
static inline void __sk_del_node(struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
502
503
504
505
{
	__hlist_del(&sk->sk_node);
}

506
/* NB: equivalent to hlist_del_init_rcu */
Eric Dumazet's avatar
Eric Dumazet committed
507
static inline bool __sk_del_node_init(struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
508
509
510
511
{
	if (sk_hashed(sk)) {
		__sk_del_node(sk);
		sk_node_init(&sk->sk_node);
Eric Dumazet's avatar
Eric Dumazet committed
512
		return true;
Linus Torvalds's avatar
Linus Torvalds committed
513
	}
Eric Dumazet's avatar
Eric Dumazet committed
514
	return false;
Linus Torvalds's avatar
Linus Torvalds committed
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
}

/* Grab socket reference count. This operation is valid only
   when sk is ALREADY grabbed f.e. it is found in hash table
   or a list and the lookup is made under lock preventing hash table
   modifications.
 */

static inline void sock_hold(struct sock *sk)
{
	atomic_inc(&sk->sk_refcnt);
}

/* Ungrab socket in the context, which assumes that socket refcnt
   cannot hit zero, f.e. it is true in context of any socketcall.
 */
static inline void __sock_put(struct sock *sk)
{
	atomic_dec(&sk->sk_refcnt);
}

Eric Dumazet's avatar
Eric Dumazet committed
536
static inline bool sk_del_node_init(struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
537
{
Eric Dumazet's avatar
Eric Dumazet committed
538
	bool rc = __sk_del_node_init(sk);
Linus Torvalds's avatar
Linus Torvalds committed
539
540
541
542
543
544
545
546

	if (rc) {
		/* paranoid for a while -acme */
		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
		__sock_put(sk);
	}
	return rc;
}
547
#define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
Linus Torvalds's avatar
Linus Torvalds committed
548

Eric Dumazet's avatar
Eric Dumazet committed
549
static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
550
551
{
	if (sk_hashed(sk)) {
552
		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
Eric Dumazet's avatar
Eric Dumazet committed
553
		return true;
554
	}
Eric Dumazet's avatar
Eric Dumazet committed
555
	return false;
556
557
}

Eric Dumazet's avatar
Eric Dumazet committed
558
static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
559
{
Eric Dumazet's avatar
Eric Dumazet committed
560
	bool rc = __sk_nulls_del_node_init_rcu(sk);
561
562
563
564
565
566
567
568
569

	if (rc) {
		/* paranoid for a while -acme */
		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
		__sock_put(sk);
	}
	return rc;
}

Eric Dumazet's avatar
Eric Dumazet committed
570
static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
Linus Torvalds's avatar
Linus Torvalds committed
571
572
573
574
{
	hlist_add_head(&sk->sk_node, list);
}

Eric Dumazet's avatar
Eric Dumazet committed
575
static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
Linus Torvalds's avatar
Linus Torvalds committed
576
577
578
579
580
{
	sock_hold(sk);
	__sk_add_node(sk, list);
}

Eric Dumazet's avatar
Eric Dumazet committed
581
static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
582
583
584
585
586
{
	sock_hold(sk);
	hlist_add_head_rcu(&sk->sk_node, list);
}

Eric Dumazet's avatar
Eric Dumazet committed
587
static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
588
{
589
	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
590
591
}

Eric Dumazet's avatar
Eric Dumazet committed
592
static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
593
594
{
	sock_hold(sk);
595
	__sk_nulls_add_node_rcu(sk, list);
596
597
}

Eric Dumazet's avatar
Eric Dumazet committed
598
static inline void __sk_del_bind_node(struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
599
600
601
602
{
	__hlist_del(&sk->sk_bind_node);
}

Eric Dumazet's avatar
Eric Dumazet committed
603
static inline void sk_add_bind_node(struct sock *sk,
Linus Torvalds's avatar
Linus Torvalds committed
604
605
606
607
608
					struct hlist_head *list)
{
	hlist_add_head(&sk->sk_bind_node, list);
}

609
610
611
612
#define sk_for_each(__sk, list) \
	hlist_for_each_entry(__sk, list, sk_node)
#define sk_for_each_rcu(__sk, list) \
	hlist_for_each_entry_rcu(__sk, list, sk_node)
613
614
615
616
#define sk_nulls_for_each(__sk, node, list) \
	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
#define sk_nulls_for_each_rcu(__sk, node, list) \
	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
617
618
#define sk_for_each_from(__sk) \
	hlist_for_each_entry_from(__sk, sk_node)
619
620
621
#define sk_nulls_for_each_from(__sk, node) \
	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
622
623
624
625
#define sk_for_each_safe(__sk, tmp, list) \
	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
#define sk_for_each_bound(__sk, list) \
	hlist_for_each_entry(__sk, list, sk_bind_node)
Linus Torvalds's avatar
Linus Torvalds committed
626

627
628
629
630
631
632
633
634
635
static inline struct user_namespace *sk_user_ns(struct sock *sk)
{
	/* Careful only use this in a context where these parameters
	 * can not change and must all be valid, such as recvmsg from
	 * userspace.
	 */
	return sk->sk_socket->file->f_cred->user_ns;
}

Linus Torvalds's avatar
Linus Torvalds committed
636
637
638
639
640
641
642
643
644
645
646
647
648
649
/* Sock flags */
enum sock_flags {
	SOCK_DEAD,
	SOCK_DONE,
	SOCK_URGINLINE,
	SOCK_KEEPOPEN,
	SOCK_LINGER,
	SOCK_DESTROY,
	SOCK_BROADCAST,
	SOCK_TIMESTAMP,
	SOCK_ZAPPED,
	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
	SOCK_DBG, /* %SO_DEBUG setting */
	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
650
	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
Linus Torvalds's avatar
Linus Torvalds committed
651
652
	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
	SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
653
	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
654
655
656
657
658
659
660
	SOCK_TIMESTAMPING_TX_HARDWARE,  /* %SOF_TIMESTAMPING_TX_HARDWARE */
	SOCK_TIMESTAMPING_TX_SOFTWARE,  /* %SOF_TIMESTAMPING_TX_SOFTWARE */
	SOCK_TIMESTAMPING_RX_HARDWARE,  /* %SOF_TIMESTAMPING_RX_HARDWARE */
	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
	SOCK_TIMESTAMPING_SOFTWARE,     /* %SOF_TIMESTAMPING_SOFTWARE */
	SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */
	SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */
Eric Dumazet's avatar
Eric Dumazet committed
661
	SOCK_FASYNC, /* fasync() active */
662
	SOCK_RXQ_OVFL,
663
	SOCK_ZEROCOPY, /* buffers from userspace */
664
	SOCK_WIFI_STATUS, /* push wifi status to userspace */
665
666
667
668
	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
		     * Will use last 4 bytes of packet sent from
		     * user-space instead.
		     */
669
	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
670
	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
Linus Torvalds's avatar
Linus Torvalds committed
671
672
};

Ralf Baechle's avatar
Ralf Baechle committed
673
674
675
676
677
static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
{
	nsk->sk_flags = osk->sk_flags;
}

Linus Torvalds's avatar
Linus Torvalds committed
678
679
680
681
682
683
684
685
686
687
static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
{
	__set_bit(flag, &sk->sk_flags);
}

static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
{
	__clear_bit(flag, &sk->sk_flags);
}

Eric Dumazet's avatar
Eric Dumazet committed
688
static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
Linus Torvalds's avatar
Linus Torvalds committed
689
690
691
692
{
	return test_bit(flag, &sk->sk_flags);
}

693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
#ifdef CONFIG_NET
extern struct static_key memalloc_socks;
static inline int sk_memalloc_socks(void)
{
	return static_key_false(&memalloc_socks);
}
#else

static inline int sk_memalloc_socks(void)
{
	return 0;
}

#endif

708
709
static inline gfp_t sk_gfp_atomic(struct sock *sk, gfp_t gfp_mask)
{
710
	return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC);
711
712
}

Linus Torvalds's avatar
Linus Torvalds committed
713
714
715
716
717
718
719
720
721
722
static inline void sk_acceptq_removed(struct sock *sk)
{
	sk->sk_ack_backlog--;
}

static inline void sk_acceptq_added(struct sock *sk)
{
	sk->sk_ack_backlog++;
}

Eric Dumazet's avatar
Eric Dumazet committed
723
static inline bool sk_acceptq_is_full(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
724
{
725
	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
Linus Torvalds's avatar
Linus Torvalds committed
726
727
728
729
730
}

/*
 * Compute minimal free write space needed to queue new packets.
 */
Eric Dumazet's avatar
Eric Dumazet committed
731
static inline int sk_stream_min_wspace(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
732
{
733
	return sk->sk_wmem_queued >> 1;
Linus Torvalds's avatar
Linus Torvalds committed
734
735
}

Eric Dumazet's avatar
Eric Dumazet committed
736
static inline int sk_stream_wspace(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
737
738
739
740
741
742
{
	return sk->sk_sndbuf - sk->sk_wmem_queued;
}

extern void sk_stream_write_space(struct sock *sk);

Eric Dumazet's avatar
Eric Dumazet committed
743
static inline bool sk_stream_memory_free(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
744
745
746
747
{
	return sk->sk_wmem_queued < sk->sk_sndbuf;
}

Zhu Yi's avatar
Zhu Yi committed
748
/* OOB backlog add */
Zhu Yi's avatar
Zhu Yi committed
749
static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
750
{
Eric Dumazet's avatar
Eric Dumazet committed
751
752
753
754
755
756
	/* dont let skb dst not refcounted, we are going to leave rcu lock */
	skb_dst_force(skb);

	if (!sk->sk_backlog.tail)
		sk->sk_backlog.head = skb;
	else
757
		sk->sk_backlog.tail->next = skb;
Eric Dumazet's avatar
Eric Dumazet committed
758
759

	sk->sk_backlog.tail = skb;
760
761
	skb->next = NULL;
}
Linus Torvalds's avatar
Linus Torvalds committed
762

763
764
/*
 * Take into account size of receive queue and backlog queue
Eric Dumazet's avatar
Eric Dumazet committed
765
766
 * Do not take into account this skb truesize,
 * to allow even a single big packet to come.
767
 */
768
769
static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb,
				     unsigned int limit)
770
771
772
{
	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);

773
	return qsize > limit;
774
775
}

Zhu Yi's avatar
Zhu Yi committed
776
/* The per-socket spinlock must be held here. */
777
778
static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
					      unsigned int limit)
Zhu Yi's avatar
Zhu Yi committed
779
{
780
	if (sk_rcvqueues_full(sk, skb, limit))
Zhu Yi's avatar
Zhu Yi committed
781
782
		return -ENOBUFS;

Zhu Yi's avatar
Zhu Yi committed
783
	__sk_add_backlog(sk, skb);
Zhu Yi's avatar
Zhu Yi committed
784
785
786
787
	sk->sk_backlog.len += skb->truesize;
	return 0;
}

788
789
extern int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);

790
791
static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
792
793
794
	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
		return __sk_backlog_rcv(sk, skb);

795
796
797
	return sk->sk_backlog_rcv(sk, skb);
}

798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
static inline void sock_rps_record_flow(const struct sock *sk)
{
#ifdef CONFIG_RPS
	struct rps_sock_flow_table *sock_flow_table;

	rcu_read_lock();
	sock_flow_table = rcu_dereference(rps_sock_flow_table);
	rps_record_sock_flow(sock_flow_table, sk->sk_rxhash);
	rcu_read_unlock();
#endif
}

static inline void sock_rps_reset_flow(const struct sock *sk)
{
#ifdef CONFIG_RPS
	struct rps_sock_flow_table *sock_flow_table;

	rcu_read_lock();
	sock_flow_table = rcu_dereference(rps_sock_flow_table);
	rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash);
	rcu_read_unlock();
#endif
}

822
823
static inline void sock_rps_save_rxhash(struct sock *sk,
					const struct sk_buff *skb)
824
825
{
#ifdef CONFIG_RPS
826
	if (unlikely(sk->sk_rxhash != skb->rxhash)) {
827
		sock_rps_reset_flow(sk);
828
		sk->sk_rxhash = skb->rxhash;
829
830
831
832
	}
#endif
}

833
834
835
836
837
838
839
840
static inline void sock_rps_reset_rxhash(struct sock *sk)
{
#ifdef CONFIG_RPS
	sock_rps_reset_flow(sk);
	sk->sk_rxhash = 0;
#endif
}

841
842
843
844
845
846
847
848
849
850
851
#define sk_wait_event(__sk, __timeo, __condition)			\
	({	int __rc;						\
		release_sock(__sk);					\
		__rc = __condition;					\
		if (!__rc) {						\
			*(__timeo) = schedule_timeout(*(__timeo));	\
		}							\
		lock_sock(__sk);					\
		__rc = __condition;					\
		__rc;							\
	})
Linus Torvalds's avatar
Linus Torvalds committed
852
853
854
855
856
857

extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
extern void sk_stream_wait_close(struct sock *sk, long timeo_p);
extern int sk_stream_error(struct sock *sk, int flags, int err);
extern void sk_stream_kill_queues(struct sock *sk);
858
859
extern void sk_set_memalloc(struct sock *sk);
extern void sk_clear_memalloc(struct sock *sk);
Linus Torvalds's avatar
Linus Torvalds committed
860
861
862

extern int sk_wait_data(struct sock *sk, long *timeo);

863
struct request_sock_ops;
864
struct timewait_sock_ops;
865
struct inet_hashinfo;
866
struct raw_hashinfo;
867
struct module;
868

Linus Torvalds's avatar
Linus Torvalds committed
869
870
871
872
873
/* Networking protocol blocks we attach to sockets.
 * socket layer -> transport layer interface
 * transport -> network interface is defined by struct inet_proto
 */
struct proto {
Eric Dumazet's avatar
Eric Dumazet committed
874
	void			(*close)(struct sock *sk,
Linus Torvalds's avatar
Linus Torvalds committed
875
876
					long timeout);
	int			(*connect)(struct sock *sk,
Eric Dumazet's avatar
Eric Dumazet committed
877
					struct sockaddr *uaddr,
Linus Torvalds's avatar
Linus Torvalds committed
878
879
880
					int addr_len);
	int			(*disconnect)(struct sock *sk, int flags);

Eric Dumazet's avatar
Eric Dumazet committed
881
	struct sock *		(*accept)(struct sock *sk, int flags, int *err);
Linus Torvalds's avatar
Linus Torvalds committed
882
883
884
885

	int			(*ioctl)(struct sock *sk, int cmd,
					 unsigned long arg);
	int			(*init)(struct sock *sk);
886
	void			(*destroy)(struct sock *sk);
Linus Torvalds's avatar
Linus Torvalds committed
887
	void			(*shutdown)(struct sock *sk, int how);
Eric Dumazet's avatar
Eric Dumazet committed
888
	int			(*setsockopt)(struct sock *sk, int level,
Linus Torvalds's avatar
Linus Torvalds committed
889
					int optname, char __user *optval,
890
					unsigned int optlen);
Eric Dumazet's avatar
Eric Dumazet committed
891
892
893
	int			(*getsockopt)(struct sock *sk, int level,
					int optname, char __user *optval,
					int __user *option);
894
#ifdef CONFIG_COMPAT
895
896
897
	int			(*compat_setsockopt)(struct sock *sk,
					int level,
					int optname, char __user *optval,
898
					unsigned int optlen);
899
900
901
902
	int			(*compat_getsockopt)(struct sock *sk,
					int level,
					int optname, char __user *optval,
					int __user *option);
903
904
	int			(*compat_ioctl)(struct sock *sk,
					unsigned int cmd, unsigned long arg);
905
#endif
Linus Torvalds's avatar
Linus Torvalds committed
906
907
908
909
	int			(*sendmsg)(struct kiocb *iocb, struct sock *sk,
					   struct msghdr *msg, size_t len);
	int			(*recvmsg)(struct kiocb *iocb, struct sock *sk,
					   struct msghdr *msg,
Eric Dumazet's avatar
Eric Dumazet committed
910
911
					   size_t len, int noblock, int flags,
					   int *addr_len);
Linus Torvalds's avatar
Linus Torvalds committed
912
913
	int			(*sendpage)(struct sock *sk, struct page *page,
					int offset, size_t size, int flags);
Eric Dumazet's avatar
Eric Dumazet committed
914
	int			(*bind)(struct sock *sk,
Linus Torvalds's avatar
Linus Torvalds committed
915
916
					struct sockaddr *uaddr, int addr_len);

Eric Dumazet's avatar
Eric Dumazet committed
917
	int			(*backlog_rcv) (struct sock *sk,
Linus Torvalds's avatar
Linus Torvalds committed
918
919
						struct sk_buff *skb);

Eric Dumazet's avatar
Eric Dumazet committed
920
	void		(*release_cb)(struct sock *sk);
921
	void		(*mtu_reduced)(struct sock *sk);
Eric Dumazet's avatar
Eric Dumazet committed
922

Linus Torvalds's avatar
Linus Torvalds committed
923
924
925
	/* Keeping track of sk's, looking them up, and port selection methods. */
	void			(*hash)(struct sock *sk);
	void			(*unhash)(struct sock *sk);
Eric Dumazet's avatar
Eric Dumazet committed
926
	void			(*rehash)(struct sock *sk);
Linus Torvalds's avatar
Linus Torvalds committed
927
	int			(*get_port)(struct sock *sk, unsigned short snum);
928
	void			(*clear_sk)(struct sock *sk, int size);
Linus Torvalds's avatar
Linus Torvalds committed
929

930
	/* Keeping track of sockets in use */
931
#ifdef CONFIG_PROC_FS
932
	unsigned int		inuse_idx;
933
#endif
934

Linus Torvalds's avatar
Linus Torvalds committed
935
	/* Memory pressure */
936
	void			(*enter_memory_pressure)(struct sock *sk);
Eric Dumazet's avatar
Eric Dumazet committed
937
	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
938
	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
Linus Torvalds's avatar
Linus Torvalds committed
939
940
941
	/*
	 * Pressure flag: try to collapse.
	 * Technical note: it is used by multiple contexts non atomically.
942
	 * All the __sk_mem_schedule() is of this nature: accounting
Linus Torvalds's avatar
Linus Torvalds committed
943
944
945
	 * is strict, actions are advisory and have some latency.
	 */
	int			*memory_pressure;
Eric Dumazet's avatar
Eric Dumazet committed
946
	long			*sysctl_mem;
Linus Torvalds's avatar
Linus Torvalds committed
947
948
949
	int			*sysctl_wmem;
	int			*sysctl_rmem;
	int			max_header;
950
	bool			no_autobind;
Linus Torvalds's avatar
Linus Torvalds committed
951

952
	struct kmem_cache	*slab;
Linus Torvalds's avatar
Linus Torvalds committed
953
	unsigned int		obj_size;
954
	int			slab_flags;
Linus Torvalds's avatar
Linus Torvalds committed
955

956
	struct percpu_counter	*orphan_count;
957

958
	struct request_sock_ops	*rsk_prot;
959
	struct timewait_sock_ops *twsk_prot;
960

961
962
	union {
		struct inet_hashinfo	*hashinfo;
963
		struct udp_table	*udp_table;
964
		struct raw_hashinfo	*raw_hash;
965
	} h;
966

Linus Torvalds's avatar
Linus Torvalds committed
967
968
969
970
971
	struct module		*owner;

	char			name[32];

	struct list_head	node;
972
973
974
#ifdef SOCK_REFCNT_DEBUG
	atomic_t		socks;
#endif
Andrew Morton's avatar
Andrew Morton committed
975
#ifdef CONFIG_MEMCG_KMEM
Glauber Costa's avatar
Glauber Costa committed
976
977
978
979
980
981
	/*
	 * cgroup specific init/deinit functions. Called once for all
	 * protocols that implement it, from cgroups populate function.
	 * This function has to setup any files the protocol want to
	 * appear in the kmem cgroup filesystem.
	 */
982
	int			(*init_cgroup)(struct mem_cgroup *memcg,
Glauber Costa's avatar
Glauber Costa committed
983
					       struct cgroup_subsys *ss);
984
	void			(*destroy_cgroup)(struct mem_cgroup *memcg);
Glauber Costa's avatar
Glauber Costa committed
985
986
987
988
	struct cg_proto		*(*proto_cgroup)(struct mem_cgroup *memcg);
#endif
};

989
990
991
992
993
994
995
996
997
998
/*
 * Bits in struct cg_proto.flags
 */
enum cg_proto_flags {
	/* Currently active and new sockets should be assigned to cgroups */
	MEMCG_SOCK_ACTIVE,
	/* It was ever activated; we must disarm static keys on destruction */
	MEMCG_SOCK_ACTIVATED,
};

Glauber Costa's avatar
Glauber Costa committed
999
1000
struct cg_proto {
	void			(*enter_memory_pressure)(struct sock *sk);