sock.h 62 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
 *	struct sock_common - minimal network layer representation of sockets
131 132
 *	@skc_daddr: Foreign IPv4 addr
 *	@skc_rcv_saddr: Bound local IPv4 addr
Eric Dumazet's avatar
Eric Dumazet committed
133
 *	@skc_hash: hash value used with various protocol lookup tables
134
 *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
135 136 137 138 139
 *	@skc_family: network address family
 *	@skc_state: Connection state
 *	@skc_reuse: %SO_REUSEADDR setting
 *	@skc_bound_dev_if: bound device index if != 0
 *	@skc_bind_node: bind hash linkage for various protocol lookup tables
140
 *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
141
 *	@skc_prot: protocol handlers inside a network family
142
 *	@skc_net: reference to the network namespace of this socket
143 144 145 146
 *	@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
147 148
 *
 *	This is the minimal network layer representation of sockets, the header
149 150
 *	for struct sock and struct inet_timewait_sock.
 */
Linus Torvalds's avatar
Linus Torvalds committed
151
struct sock_common {
152 153
	/* skc_daddr and skc_rcv_saddr must be grouped :
	 * cf INET_MATCH() and INET_TW_MATCH()
Eric Dumazet's avatar
Eric Dumazet committed
154
	 */
155 156
	__be32			skc_daddr;
	__be32			skc_rcv_saddr;
Eric Dumazet's avatar
Eric Dumazet committed
157

158 159 160 161
	union  {
		unsigned int	skc_hash;
		__u16		skc_u16hashes[2];
	};
Eric Dumazet's avatar
Eric Dumazet committed
162 163 164 165
	unsigned short		skc_family;
	volatile unsigned char	skc_state;
	unsigned char		skc_reuse;
	int			skc_bound_dev_if;
166 167 168 169
	union {
		struct hlist_node	skc_bind_node;
		struct hlist_nulls_node skc_portaddr_node;
	};
170
	struct proto		*skc_prot;
171
#ifdef CONFIG_NET_NS
172
	struct net	 	*skc_net;
173
#endif
174 175 176 177
	/*
	 * fields between dontcopy_begin/dontcopy_end
	 * are not copied in sock_copy()
	 */
178
	/* private: */
179
	int			skc_dontcopy_begin[0];
180
	/* public: */
181 182 183 184 185 186
	union {
		struct hlist_node	skc_node;
		struct hlist_nulls_node skc_nulls_node;
	};
	int			skc_tx_queue_mapping;
	atomic_t		skc_refcnt;
187
	/* private: */
188
	int                     skc_dontcopy_end[0];
189
	/* public: */
Linus Torvalds's avatar
Linus Torvalds committed
190 191
};

Glauber Costa's avatar
Glauber Costa committed
192
struct cg_proto;
Linus Torvalds's avatar
Linus Torvalds committed
193 194
/**
  *	struct sock - network layer representation of sockets
195
  *	@__sk_common: shared layout with inet_timewait_sock
196 197 198 199
  *	@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
200
  *	@sk_wq: sock wait queue and async head
Eric Dumazet's avatar
Eric Dumazet committed
201
  *	@sk_rx_dst: receive input route used by early tcp demux
202 203 204 205 206 207
  *	@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
208
  *	@sk_async_wait_queue: DMA copied packets
209 210 211 212 213
  *	@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
214
  *	@sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
215
  *		   %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
216 217
  *	@sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets
  *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
Eric Dumazet's avatar
Eric Dumazet committed
218
  *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
219
  *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
220
  *	@sk_gso_max_size: Maximum GSO segment size to build
221
  *	@sk_gso_max_segs: Maximum number of GSO segments
222 223 224 225
  *	@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
226 227
  *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
  *			  IPV6_ADDRFORM for instance)
228
  *	@sk_err: last error
Wang Chen's avatar
Wang Chen committed
229 230
  *	@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
231
  *	@sk_drops: raw/udp drops counter
232 233 234
  *	@sk_ack_backlog: current listen backlog
  *	@sk_max_ack_backlog: listen backlog set in listen()
  *	@sk_priority: %SO_PRIORITY setting
235
  *	@sk_cgrp_prioidx: socket group's priority map index
236 237
  *	@sk_type: socket type (%SOCK_STREAM, etc)
  *	@sk_protocol: which protocol this socket belongs in this network family
238 239
  *	@sk_peer_pid: &struct pid for this socket's peer
  *	@sk_peer_cred: %SO_PEERCRED setting
240 241 242
  *	@sk_rcvlowat: %SO_RCVLOWAT setting
  *	@sk_rcvtimeo: %SO_RCVTIMEO setting
  *	@sk_sndtimeo: %SO_SNDTIMEO setting
243
  *	@sk_rxhash: flow hash received from netif layer
244 245 246 247 248 249 250 251
  *	@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
  *	@sk_sndmsg_page: cached page for sendmsg
  *	@sk_sndmsg_off: cached offset for sendmsg
252
  *	@sk_peek_off: current peek_offset value
253
  *	@sk_send_head: front of stuff to transmit
254
  *	@sk_security: used by security modules
255
  *	@sk_mark: generic packet mark
256
  *	@sk_classid: this socket's cgroup classid
Glauber Costa's avatar
Glauber Costa committed
257
  *	@sk_cgrp: this socket's cgroup-specific proto data
258 259 260 261 262 263 264
  *	@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
265 266 267
 */
struct sock {
	/*
268
	 * Now struct inet_timewait_sock also uses sock_common, so please just
Linus Torvalds's avatar
Linus Torvalds committed
269 270 271
	 * don't add nothing before this first member (__sk_common) --acme
	 */
	struct sock_common	__sk_common;
Eric Dumazet's avatar
Eric Dumazet committed
272 273 274
#define sk_node			__sk_common.skc_node
#define sk_nulls_node		__sk_common.skc_nulls_node
#define sk_refcnt		__sk_common.skc_refcnt
275
#define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
Eric Dumazet's avatar
Eric Dumazet committed
276

277 278
#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
279
#define sk_hash			__sk_common.skc_hash
Linus Torvalds's avatar
Linus Torvalds committed
280 281 282 283 284
#define sk_family		__sk_common.skc_family
#define sk_state		__sk_common.skc_state
#define sk_reuse		__sk_common.skc_reuse
#define sk_bound_dev_if		__sk_common.skc_bound_dev_if
#define sk_bind_node		__sk_common.skc_bind_node
285
#define sk_prot			__sk_common.skc_prot
286
#define sk_net			__sk_common.skc_net
Linus Torvalds's avatar
Linus Torvalds committed
287
	socket_lock_t		sk_lock;
Eric Dumazet's avatar
Eric Dumazet committed
288
	struct sk_buff_head	sk_receive_queue;
289 290 291 292
	/*
	 * 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
293 294 295
	 * Note : rmem_alloc is in this structure to fill a hole
	 * on 64bit arches, not because its logically part of
	 * backlog.
296 297
	 */
	struct {
Eric Dumazet's avatar
Eric Dumazet committed
298 299 300 301
		atomic_t	rmem_alloc;
		int		len;
		struct sk_buff	*head;
		struct sk_buff	*tail;
302
	} sk_backlog;
Eric Dumazet's avatar
Eric Dumazet committed
303 304 305 306 307 308 309 310 311
#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;
312
	struct socket_wq __rcu	*sk_wq;
Eric Dumazet's avatar
Eric Dumazet committed
313 314 315 316 317

#ifdef CONFIG_NET_DMA
	struct sk_buff_head	sk_async_wait_queue;
#endif

318
#ifdef CONFIG_XFRM
Linus Torvalds's avatar
Linus Torvalds committed
319
	struct xfrm_policy	*sk_policy[2];
320
#endif
Eric Dumazet's avatar
Eric Dumazet committed
321
	unsigned long 		sk_flags;
Eric Dumazet's avatar
Eric Dumazet committed
322
	struct dst_entry	*sk_rx_dst;
Eric Dumazet's avatar
Eric Dumazet committed
323
	struct dst_entry	*sk_dst_cache;
Eric Dumazet's avatar
Eric Dumazet committed
324
	spinlock_t		sk_dst_lock;
Linus Torvalds's avatar
Linus Torvalds committed
325 326
	atomic_t		sk_wmem_alloc;
	atomic_t		sk_omem_alloc;
327
	int			sk_sndbuf;
Linus Torvalds's avatar
Linus Torvalds committed
328
	struct sk_buff_head	sk_write_queue;
Eric Dumazet's avatar
Eric Dumazet committed
329 330 331 332 333 334 335
	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
336
	int			sk_wmem_queued;
Al Viro's avatar
Al Viro committed
337
	gfp_t			sk_allocation;
338 339
	netdev_features_t	sk_route_caps;
	netdev_features_t	sk_route_nocaps;
340
	int			sk_gso_type;
341
	unsigned int		sk_gso_max_size;
342
	u16			sk_gso_max_segs;
343
	int			sk_rcvlowat;
Linus Torvalds's avatar
Linus Torvalds committed
344 345
	unsigned long	        sk_lingertime;
	struct sk_buff_head	sk_error_queue;
346
	struct proto		*sk_prot_creator;
Linus Torvalds's avatar
Linus Torvalds committed
347 348 349 350 351 352
	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;
353 354 355
#ifdef CONFIG_CGROUPS
	__u32			sk_cgrp_prioidx;
#endif
356 357
	struct pid		*sk_peer_pid;
	const struct cred	*sk_peer_cred;
Linus Torvalds's avatar
Linus Torvalds committed
358 359 360 361
	long			sk_rcvtimeo;
	long			sk_sndtimeo;
	void			*sk_protinfo;
	struct timer_list	sk_timer;
362
	ktime_t			sk_stamp;
Linus Torvalds's avatar
Linus Torvalds committed
363 364 365 366 367
	struct socket		*sk_socket;
	void			*sk_user_data;
	struct page		*sk_sndmsg_page;
	struct sk_buff		*sk_send_head;
	__u32			sk_sndmsg_off;
368
	__s32			sk_peek_off;
Linus Torvalds's avatar
Linus Torvalds committed
369
	int			sk_write_pending;
Alexey Dobriyan's avatar
Alexey Dobriyan committed
370
#ifdef CONFIG_SECURITY
Linus Torvalds's avatar
Linus Torvalds committed
371
	void			*sk_security;
Alexey Dobriyan's avatar
Alexey Dobriyan committed
372
#endif
373
	__u32			sk_mark;
374
	u32			sk_classid;
Glauber Costa's avatar
Glauber Costa committed
375
	struct cg_proto		*sk_cgrp;
Linus Torvalds's avatar
Linus Torvalds committed
376 377 378 379
	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
380 381
	int			(*sk_backlog_rcv)(struct sock *sk,
						  struct sk_buff *skb);
Linus Torvalds's avatar
Linus Torvalds committed
382 383 384
	void                    (*sk_destruct)(struct sock *sk);
};

385 386 387 388 389 390 391 392 393 394 395
/*
 * 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

396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419
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
420 421 422
/*
 * Hashed lists helper routines
 */
Li Zefan's avatar
Li Zefan committed
423 424 425 426 427
static inline struct sock *sk_entry(const struct hlist_node *node)
{
	return hlist_entry(node, struct sock, sk_node);
}

428
static inline struct sock *__sk_head(const struct hlist_head *head)
Linus Torvalds's avatar
Linus Torvalds committed
429 430 431 432
{
	return hlist_entry(head->first, struct sock, sk_node);
}

433
static inline struct sock *sk_head(const struct hlist_head *head)
Linus Torvalds's avatar
Linus Torvalds committed
434 435 436 437
{
	return hlist_empty(head) ? NULL : __sk_head(head);
}

438 439 440 441 442 443 444 445 446 447
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);
}

448
static inline struct sock *sk_next(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
449 450 451 452 453
{
	return sk->sk_node.next ?
		hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
}

454 455 456 457 458 459 460 461
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
462
static inline bool sk_unhashed(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
463 464 465 466
{
	return hlist_unhashed(&sk->sk_node);
}

Eric Dumazet's avatar
Eric Dumazet committed
467
static inline bool sk_hashed(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
468
{
Akinobu Mita's avatar
Akinobu Mita committed
469
	return !sk_unhashed(sk);
Linus Torvalds's avatar
Linus Torvalds committed
470 471
}

Eric Dumazet's avatar
Eric Dumazet committed
472
static inline void sk_node_init(struct hlist_node *node)
Linus Torvalds's avatar
Linus Torvalds committed
473 474 475 476
{
	node->pprev = NULL;
}

Eric Dumazet's avatar
Eric Dumazet committed
477
static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
478 479 480 481
{
	node->pprev = NULL;
}

Eric Dumazet's avatar
Eric Dumazet committed
482
static inline void __sk_del_node(struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
483 484 485 486
{
	__hlist_del(&sk->sk_node);
}

487
/* NB: equivalent to hlist_del_init_rcu */
Eric Dumazet's avatar
Eric Dumazet committed
488
static inline bool __sk_del_node_init(struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
489 490 491 492
{
	if (sk_hashed(sk)) {
		__sk_del_node(sk);
		sk_node_init(&sk->sk_node);
Eric Dumazet's avatar
Eric Dumazet committed
493
		return true;
Linus Torvalds's avatar
Linus Torvalds committed
494
	}
Eric Dumazet's avatar
Eric Dumazet committed
495
	return false;
Linus Torvalds's avatar
Linus Torvalds committed
496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516
}

/* 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
517
static inline bool sk_del_node_init(struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
518
{
Eric Dumazet's avatar
Eric Dumazet committed
519
	bool rc = __sk_del_node_init(sk);
Linus Torvalds's avatar
Linus Torvalds committed
520 521 522 523 524 525 526 527

	if (rc) {
		/* paranoid for a while -acme */
		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
		__sock_put(sk);
	}
	return rc;
}
528
#define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
Linus Torvalds's avatar
Linus Torvalds committed
529

Eric Dumazet's avatar
Eric Dumazet committed
530
static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
531 532
{
	if (sk_hashed(sk)) {
533
		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
Eric Dumazet's avatar
Eric Dumazet committed
534
		return true;
535
	}
Eric Dumazet's avatar
Eric Dumazet committed
536
	return false;
537 538
}

Eric Dumazet's avatar
Eric Dumazet committed
539
static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
540
{
Eric Dumazet's avatar
Eric Dumazet committed
541
	bool rc = __sk_nulls_del_node_init_rcu(sk);
542 543 544 545 546 547 548 549 550

	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
551
static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
Linus Torvalds's avatar
Linus Torvalds committed
552 553 554 555
{
	hlist_add_head(&sk->sk_node, list);
}

Eric Dumazet's avatar
Eric Dumazet committed
556
static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
Linus Torvalds's avatar
Linus Torvalds committed
557 558 559 560 561
{
	sock_hold(sk);
	__sk_add_node(sk, list);
}

Eric Dumazet's avatar
Eric Dumazet committed
562
static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
563 564 565 566 567
{
	sock_hold(sk);
	hlist_add_head_rcu(&sk->sk_node, list);
}

Eric Dumazet's avatar
Eric Dumazet committed
568
static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
569
{
570
	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
571 572
}

Eric Dumazet's avatar
Eric Dumazet committed
573
static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
574 575
{
	sock_hold(sk);
576
	__sk_nulls_add_node_rcu(sk, list);
577 578
}

Eric Dumazet's avatar
Eric Dumazet committed
579
static inline void __sk_del_bind_node(struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
580 581 582 583
{
	__hlist_del(&sk->sk_bind_node);
}

Eric Dumazet's avatar
Eric Dumazet committed
584
static inline void sk_add_bind_node(struct sock *sk,
Linus Torvalds's avatar
Linus Torvalds committed
585 586 587 588 589 590 591
					struct hlist_head *list)
{
	hlist_add_head(&sk->sk_bind_node, list);
}

#define sk_for_each(__sk, node, list) \
	hlist_for_each_entry(__sk, node, list, sk_node)
592 593
#define sk_for_each_rcu(__sk, node, list) \
	hlist_for_each_entry_rcu(__sk, node, list, sk_node)
594 595 596 597
#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)
Linus Torvalds's avatar
Linus Torvalds committed
598 599 600
#define sk_for_each_from(__sk, node) \
	if (__sk && ({ node = &(__sk)->sk_node; 1; })) \
		hlist_for_each_entry_from(__sk, node, sk_node)
601 602 603
#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)
Linus Torvalds's avatar
Linus Torvalds committed
604 605 606 607 608
#define sk_for_each_safe(__sk, node, tmp, list) \
	hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node)
#define sk_for_each_bound(__sk, node, list) \
	hlist_for_each_entry(__sk, node, list, sk_bind_node)

609 610 611 612 613 614 615 616 617
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
618 619 620 621 622 623 624 625 626 627 628 629 630 631
/* 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 */
632
	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
Linus Torvalds's avatar
Linus Torvalds committed
633 634
	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
	SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
635
	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
636 637 638 639 640 641 642
	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
643
	SOCK_FASYNC, /* fasync() active */
644
	SOCK_RXQ_OVFL,
645
	SOCK_ZEROCOPY, /* buffers from userspace */
646
	SOCK_WIFI_STATUS, /* push wifi status to userspace */
647 648 649 650
	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
		     * Will use last 4 bytes of packet sent from
		     * user-space instead.
		     */
Linus Torvalds's avatar
Linus Torvalds committed
651 652
};

Ralf Baechle's avatar
Ralf Baechle committed
653 654 655 656 657
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
658 659 660 661 662 663 664 665 666 667
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
668
static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
Linus Torvalds's avatar
Linus Torvalds committed
669 670 671 672
{
	return test_bit(flag, &sk->sk_flags);
}

673 674 675 676 677 678 679 680 681 682 683 684 685 686 687
#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

688 689
static inline gfp_t sk_gfp_atomic(struct sock *sk, gfp_t gfp_mask)
{
690
	return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC);
691 692
}

Linus Torvalds's avatar
Linus Torvalds committed
693 694 695 696 697 698 699 700 701 702
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
703
static inline bool sk_acceptq_is_full(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
704
{
705
	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
Linus Torvalds's avatar
Linus Torvalds committed
706 707 708 709 710
}

/*
 * Compute minimal free write space needed to queue new packets.
 */
Eric Dumazet's avatar
Eric Dumazet committed
711
static inline int sk_stream_min_wspace(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
712
{
713
	return sk->sk_wmem_queued >> 1;
Linus Torvalds's avatar
Linus Torvalds committed
714 715
}

Eric Dumazet's avatar
Eric Dumazet committed
716
static inline int sk_stream_wspace(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
717 718 719 720 721 722
{
	return sk->sk_sndbuf - sk->sk_wmem_queued;
}

extern void sk_stream_write_space(struct sock *sk);

Eric Dumazet's avatar
Eric Dumazet committed
723
static inline bool sk_stream_memory_free(const struct sock *sk)
Linus Torvalds's avatar
Linus Torvalds committed
724 725 726 727
{
	return sk->sk_wmem_queued < sk->sk_sndbuf;
}

Zhu Yi's avatar
Zhu Yi committed
728
/* OOB backlog add */
Zhu Yi's avatar
Zhu Yi committed
729
static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
730
{
Eric Dumazet's avatar
Eric Dumazet committed
731 732 733 734 735 736
	/* 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
737
		sk->sk_backlog.tail->next = skb;
Eric Dumazet's avatar
Eric Dumazet committed
738 739

	sk->sk_backlog.tail = skb;
740 741
	skb->next = NULL;
}
Linus Torvalds's avatar
Linus Torvalds committed
742

743 744
/*
 * Take into account size of receive queue and backlog queue
Eric Dumazet's avatar
Eric Dumazet committed
745 746
 * Do not take into account this skb truesize,
 * to allow even a single big packet to come.
747
 */
748 749
static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb,
				     unsigned int limit)
750 751 752
{
	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);

753
	return qsize > limit;
754 755
}

Zhu Yi's avatar
Zhu Yi committed
756
/* The per-socket spinlock must be held here. */
757 758
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
759
{
760
	if (sk_rcvqueues_full(sk, skb, limit))
Zhu Yi's avatar
Zhu Yi committed
761 762
		return -ENOBUFS;

Zhu Yi's avatar
Zhu Yi committed
763
	__sk_add_backlog(sk, skb);
Zhu Yi's avatar
Zhu Yi committed
764 765 766 767
	sk->sk_backlog.len += skb->truesize;
	return 0;
}

768 769
extern int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);

770 771
static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
772 773 774
	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
		return __sk_backlog_rcv(sk, skb);

775 776 777
	return sk->sk_backlog_rcv(sk, skb);
}

778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801
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
}

802 803
static inline void sock_rps_save_rxhash(struct sock *sk,
					const struct sk_buff *skb)
804 805
{
#ifdef CONFIG_RPS
806
	if (unlikely(sk->sk_rxhash != skb->rxhash)) {
807
		sock_rps_reset_flow(sk);
808
		sk->sk_rxhash = skb->rxhash;
809 810 811 812
	}
#endif
}

813 814 815 816 817 818 819 820
static inline void sock_rps_reset_rxhash(struct sock *sk)
{
#ifdef CONFIG_RPS
	sock_rps_reset_flow(sk);
	sk->sk_rxhash = 0;
#endif
}

821 822 823 824 825 826 827 828 829 830 831
#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
832 833 834 835 836 837

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);
838 839
extern void sk_set_memalloc(struct sock *sk);
extern void sk_clear_memalloc(struct sock *sk);
Linus Torvalds's avatar
Linus Torvalds committed
840 841 842

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

843
struct request_sock_ops;
844
struct timewait_sock_ops;
845
struct inet_hashinfo;
846
struct raw_hashinfo;
847
struct module;
848

Linus Torvalds's avatar
Linus Torvalds committed
849 850 851 852 853
/* 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
854
	void			(*close)(struct sock *sk,
Linus Torvalds's avatar
Linus Torvalds committed
855 856
					long timeout);
	int			(*connect)(struct sock *sk,
Eric Dumazet's avatar
Eric Dumazet committed
857
					struct sockaddr *uaddr,
Linus Torvalds's avatar
Linus Torvalds committed
858 859 860
					int addr_len);
	int			(*disconnect)(struct sock *sk, int flags);

Eric Dumazet's avatar
Eric Dumazet committed
861
	struct sock *		(*accept)(struct sock *sk, int flags, int *err);
Linus Torvalds's avatar
Linus Torvalds committed
862 863 864 865

	int			(*ioctl)(struct sock *sk, int cmd,
					 unsigned long arg);
	int			(*init)(struct sock *sk);
866
	void			(*destroy)(struct sock *sk);
Linus Torvalds's avatar
Linus Torvalds committed
867
	void			(*shutdown)(struct sock *sk, int how);
Eric Dumazet's avatar
Eric Dumazet committed
868
	int			(*setsockopt)(struct sock *sk, int level,
Linus Torvalds's avatar
Linus Torvalds committed
869
					int optname, char __user *optval,
870
					unsigned int optlen);
Eric Dumazet's avatar
Eric Dumazet committed
871 872 873
	int			(*getsockopt)(struct sock *sk, int level,
					int optname, char __user *optval,
					int __user *option);
874
#ifdef CONFIG_COMPAT
875 876 877
	int			(*compat_setsockopt)(struct sock *sk,
					int level,
					int optname, char __user *optval,
878
					unsigned int optlen);
879 880 881 882
	int			(*compat_getsockopt)(struct sock *sk,
					int level,
					int optname, char __user *optval,
					int __user *option);
883 884
	int			(*compat_ioctl)(struct sock *sk,
					unsigned int cmd, unsigned long arg);
885
#endif
Linus Torvalds's avatar
Linus Torvalds committed
886 887 888 889
	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
890 891
					   size_t len, int noblock, int flags,
					   int *addr_len);
Linus Torvalds's avatar
Linus Torvalds committed
892 893
	int			(*sendpage)(struct sock *sk, struct page *page,
					int offset, size_t size, int flags);
Eric Dumazet's avatar
Eric Dumazet committed
894
	int			(*bind)(struct sock *sk,
Linus Torvalds's avatar
Linus Torvalds committed
895 896
					struct sockaddr *uaddr, int addr_len);

Eric Dumazet's avatar
Eric Dumazet committed
897
	int			(*backlog_rcv) (struct sock *sk,
Linus Torvalds's avatar
Linus Torvalds committed
898 899
						struct sk_buff *skb);

Eric Dumazet's avatar
Eric Dumazet committed
900
	void		(*release_cb)(struct sock *sk);
901
	void		(*mtu_reduced)(struct sock *sk);
Eric Dumazet's avatar
Eric Dumazet committed
902

Linus Torvalds's avatar
Linus Torvalds committed
903 904 905
	/* 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
906
	void			(*rehash)(struct sock *sk);
Linus Torvalds's avatar
Linus Torvalds committed
907
	int			(*get_port)(struct sock *sk, unsigned short snum);
908
	void			(*clear_sk)(struct sock *sk, int size);
Linus Torvalds's avatar
Linus Torvalds committed
909

910
	/* Keeping track of sockets in use */
911
#ifdef CONFIG_PROC_FS
912
	unsigned int		inuse_idx;
913
#endif
914

Linus Torvalds's avatar
Linus Torvalds committed
915
	/* Memory pressure */
916
	void			(*enter_memory_pressure)(struct sock *sk);
Eric Dumazet's avatar
Eric Dumazet committed
917
	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
918
	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
Linus Torvalds's avatar
Linus Torvalds committed
919 920 921
	/*
	 * Pressure flag: try to collapse.
	 * Technical note: it is used by multiple contexts non atomically.
922
	 * All the __sk_mem_schedule() is of this nature: accounting
Linus Torvalds's avatar
Linus Torvalds committed
923 924 925
	 * is strict, actions are advisory and have some latency.
	 */
	int			*memory_pressure;
Eric Dumazet's avatar
Eric Dumazet committed
926
	long			*sysctl_mem;
Linus Torvalds's avatar
Linus Torvalds committed
927 928 929
	int			*sysctl_wmem;
	int			*sysctl_rmem;
	int			max_header;
930
	bool			no_autobind;
Linus Torvalds's avatar
Linus Torvalds committed
931

932
	struct kmem_cache	*slab;
Linus Torvalds's avatar
Linus Torvalds committed
933
	unsigned int		obj_size;
934
	int			slab_flags;
Linus Torvalds's avatar
Linus Torvalds committed
935

936
	struct percpu_counter	*orphan_count;
937

938
	struct request_sock_ops	*rsk_prot;
939
	struct timewait_sock_ops *twsk_prot;
940

941 942
	union {
		struct inet_hashinfo	*hashinfo;
943
		struct udp_table	*udp_table;
944
		struct raw_hashinfo	*raw_hash;
945
	} h;
946

Linus Torvalds's avatar
Linus Torvalds committed
947 948 949 950 951
	struct module		*owner;

	char			name[32];

	struct list_head	node;
952 953 954
#ifdef SOCK_REFCNT_DEBUG
	atomic_t		socks;
#endif
Andrew Morton's avatar
Andrew Morton committed
955
#ifdef CONFIG_MEMCG_KMEM
Glauber Costa's avatar
Glauber Costa committed
956 957 958 959 960 961
	/*
	 * 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.
	 */
962
	int			(*init_cgroup)(struct mem_cgroup *memcg,
Glauber Costa's avatar
Glauber Costa committed
963
					       struct cgroup_subsys *ss);
964
	void			(*destroy_cgroup)(struct mem_cgroup *memcg);
Glauber Costa's avatar
Glauber Costa committed
965 966 967 968
	struct cg_proto		*(*proto_cgroup)(struct mem_cgroup *memcg);
#endif
};

969 970 971 972 973 974 975 976 977 978
/*
 * 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
979 980 981 982 983 984
struct cg_proto {
	void			(*enter_memory_pressure)(struct sock *sk);
	struct res_counter	*memory_allocated;	/* Current allocated memory. */
	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
	int			*memory_pressure;
	long			*sysctl_mem;
985
	unsigned long		flags;
Glauber Costa's avatar
Glauber Costa committed
986 987 988 989 990 991 992 993 994 995
	/*
	 * memcg field is used to find which memcg we belong directly
	 * Each memcg struct can hold more than one cg_proto, so contai