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1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Definitions for the AF_INET socket handler.
7  *
8  * Version:	@(#)sock.h	1.0.4	05/13/93
9  *
10  * Authors:	Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *		Corey Minyard <wf-rch!minyard@relay.EU.net>
13  *		Florian La Roche <flla@stud.uni-sb.de>
14  *
15  * Fixes:
16  *		Alan Cox	:	Volatiles in skbuff pointers. See
17  *					skbuff comments. May be overdone,
18  *					better to prove they can be removed
19  *					than the reverse.
20  *		Alan Cox	:	Added a zapped field for tcp to note
21  *					a socket is reset and must stay shut up
22  *		Alan Cox	:	New fields for options
23  *	Pauline Middelink	:	identd support
24  *		Alan Cox	:	Eliminate low level recv/recvfrom
25  *		David S. Miller	:	New socket lookup architecture.
26  *              Steve Whitehouse:       Default routines for sock_ops
27  *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
28  *              			protinfo be just a void pointer, as the
29  *              			protocol specific parts were moved to
30  *              			respective headers and ipv4/v6, etc now
31  *              			use private slabcaches for its socks
32  *              Pedro Hortas	:	New flags field for socket options
33  *
34  *
35  *		This program is free software; you can redistribute it and/or
36  *		modify it under the terms of the GNU General Public License
37  *		as published by the Free Software Foundation; either version
38  *		2 of the License, or (at your option) any later version.
39  */
40 #ifndef _SOCK_H
41 #define _SOCK_H
42 
43 #include <linux/hardirq.h>
44 #include <linux/kernel.h>
45 #include <linux/list.h>
46 #include <linux/list_nulls.h>
47 #include <linux/timer.h>
48 #include <linux/cache.h>
49 #include <linux/bitops.h>
50 #include <linux/lockdep.h>
51 #include <linux/netdevice.h>
52 #include <linux/skbuff.h>	/* struct sk_buff */
53 #include <linux/mm.h>
54 #include <linux/security.h>
55 #include <linux/slab.h>
56 #include <linux/uaccess.h>
57 #include <linux/memcontrol.h>
58 #include <linux/res_counter.h>
59 #include <linux/static_key.h>
60 #include <linux/aio.h>
61 #include <linux/sched.h>
62 
63 #include <linux/filter.h>
64 #include <linux/rculist_nulls.h>
65 #include <linux/poll.h>
66 
67 #include <linux/atomic.h>
68 #include <net/dst.h>
69 #include <net/checksum.h>
70 #include <net/tcp_states.h>
71 #include <linux/net_tstamp.h>
72 
73 struct cgroup;
74 struct cgroup_subsys;
75 #ifdef CONFIG_NET
76 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss);
77 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg);
78 #else
79 static inline
mem_cgroup_sockets_init(struct mem_cgroup * memcg,struct cgroup_subsys * ss)80 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
81 {
82 	return 0;
83 }
84 static inline
mem_cgroup_sockets_destroy(struct mem_cgroup * memcg)85 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
86 {
87 }
88 #endif
89 /*
90  * This structure really needs to be cleaned up.
91  * Most of it is for TCP, and not used by any of
92  * the other protocols.
93  */
94 
95 /* Define this to get the SOCK_DBG debugging facility. */
96 #define SOCK_DEBUGGING
97 #ifdef SOCK_DEBUGGING
98 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
99 					printk(KERN_DEBUG msg); } while (0)
100 #else
101 /* Validate arguments and do nothing */
102 static inline __printf(2, 3)
SOCK_DEBUG(const struct sock * sk,const char * msg,...)103 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
104 {
105 }
106 #endif
107 
108 /* This is the per-socket lock.  The spinlock provides a synchronization
109  * between user contexts and software interrupt processing, whereas the
110  * mini-semaphore synchronizes multiple users amongst themselves.
111  */
112 typedef struct {
113 	spinlock_t		slock;
114 	int			owned;
115 	wait_queue_head_t	wq;
116 	/*
117 	 * We express the mutex-alike socket_lock semantics
118 	 * to the lock validator by explicitly managing
119 	 * the slock as a lock variant (in addition to
120 	 * the slock itself):
121 	 */
122 #ifdef CONFIG_DEBUG_LOCK_ALLOC
123 	struct lockdep_map dep_map;
124 #endif
125 } socket_lock_t;
126 
127 struct sock;
128 struct proto;
129 struct net;
130 
131 typedef __u32 __bitwise __portpair;
132 typedef __u64 __bitwise __addrpair;
133 
134 /**
135  *	struct sock_common - minimal network layer representation of sockets
136  *	@skc_daddr: Foreign IPv4 addr
137  *	@skc_rcv_saddr: Bound local IPv4 addr
138  *	@skc_hash: hash value used with various protocol lookup tables
139  *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
140  *	@skc_dport: placeholder for inet_dport/tw_dport
141  *	@skc_num: placeholder for inet_num/tw_num
142  *	@skc_family: network address family
143  *	@skc_state: Connection state
144  *	@skc_reuse: %SO_REUSEADDR setting
145  *	@skc_reuseport: %SO_REUSEPORT setting
146  *	@skc_bound_dev_if: bound device index if != 0
147  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
148  *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
149  *	@skc_prot: protocol handlers inside a network family
150  *	@skc_net: reference to the network namespace of this socket
151  *	@skc_node: main hash linkage for various protocol lookup tables
152  *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
153  *	@skc_tx_queue_mapping: tx queue number for this connection
154  *	@skc_refcnt: reference count
155  *
156  *	This is the minimal network layer representation of sockets, the header
157  *	for struct sock and struct inet_timewait_sock.
158  */
159 struct sock_common {
160 	/* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
161 	 * address on 64bit arches : cf INET_MATCH()
162 	 */
163 	union {
164 		__addrpair	skc_addrpair;
165 		struct {
166 			__be32	skc_daddr;
167 			__be32	skc_rcv_saddr;
168 		};
169 	};
170 	union  {
171 		unsigned int	skc_hash;
172 		__u16		skc_u16hashes[2];
173 	};
174 	/* skc_dport && skc_num must be grouped as well */
175 	union {
176 		__portpair	skc_portpair;
177 		struct {
178 			__be16	skc_dport;
179 			__u16	skc_num;
180 		};
181 	};
182 
183 	unsigned short		skc_family;
184 	volatile unsigned char	skc_state;
185 	unsigned char		skc_reuse:4;
186 	unsigned char		skc_reuseport:1;
187 	unsigned char		skc_ipv6only:1;
188 	int			skc_bound_dev_if;
189 	union {
190 		struct hlist_node	skc_bind_node;
191 		struct hlist_nulls_node skc_portaddr_node;
192 	};
193 	struct proto		*skc_prot;
194 #ifdef CONFIG_NET_NS
195 	struct net	 	*skc_net;
196 #endif
197 
198 #if IS_ENABLED(CONFIG_IPV6)
199 	struct in6_addr		skc_v6_daddr;
200 	struct in6_addr		skc_v6_rcv_saddr;
201 #endif
202 
203 	/*
204 	 * fields between dontcopy_begin/dontcopy_end
205 	 * are not copied in sock_copy()
206 	 */
207 	/* private: */
208 	int			skc_dontcopy_begin[0];
209 	/* public: */
210 	union {
211 		struct hlist_node	skc_node;
212 		struct hlist_nulls_node skc_nulls_node;
213 	};
214 	int			skc_tx_queue_mapping;
215 	atomic_t		skc_refcnt;
216 	/* private: */
217 	int                     skc_dontcopy_end[0];
218 	/* public: */
219 };
220 
221 struct cg_proto;
222 /**
223   *	struct sock - network layer representation of sockets
224   *	@__sk_common: shared layout with inet_timewait_sock
225   *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
226   *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
227   *	@sk_lock:	synchronizer
228   *	@sk_rcvbuf: size of receive buffer in bytes
229   *	@sk_wq: sock wait queue and async head
230   *	@sk_rx_dst: receive input route used by early demux
231   *	@sk_dst_cache: destination cache
232   *	@sk_dst_lock: destination cache lock
233   *	@sk_policy: flow policy
234   *	@sk_receive_queue: incoming packets
235   *	@sk_wmem_alloc: transmit queue bytes committed
236   *	@sk_write_queue: Packet sending queue
237   *	@sk_omem_alloc: "o" is "option" or "other"
238   *	@sk_wmem_queued: persistent queue size
239   *	@sk_forward_alloc: space allocated forward
240   *	@sk_napi_id: id of the last napi context to receive data for sk
241   *	@sk_ll_usec: usecs to busypoll when there is no data
242   *	@sk_allocation: allocation mode
243   *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
244   *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
245   *	@sk_sndbuf: size of send buffer in bytes
246   *	@sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
247   *		   %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
248   *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
249   *	@sk_no_check_rx: allow zero checksum in RX packets
250   *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
251   *	@sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
252   *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
253   *	@sk_gso_max_size: Maximum GSO segment size to build
254   *	@sk_gso_max_segs: Maximum number of GSO segments
255   *	@sk_lingertime: %SO_LINGER l_linger setting
256   *	@sk_backlog: always used with the per-socket spinlock held
257   *	@sk_callback_lock: used with the callbacks in the end of this struct
258   *	@sk_error_queue: rarely used
259   *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
260   *			  IPV6_ADDRFORM for instance)
261   *	@sk_err: last error
262   *	@sk_err_soft: errors that don't cause failure but are the cause of a
263   *		      persistent failure not just 'timed out'
264   *	@sk_drops: raw/udp drops counter
265   *	@sk_ack_backlog: current listen backlog
266   *	@sk_max_ack_backlog: listen backlog set in listen()
267   *	@sk_priority: %SO_PRIORITY setting
268   *	@sk_cgrp_prioidx: socket group's priority map index
269   *	@sk_type: socket type (%SOCK_STREAM, etc)
270   *	@sk_protocol: which protocol this socket belongs in this network family
271   *	@sk_peer_pid: &struct pid for this socket's peer
272   *	@sk_peer_cred: %SO_PEERCRED setting
273   *	@sk_rcvlowat: %SO_RCVLOWAT setting
274   *	@sk_rcvtimeo: %SO_RCVTIMEO setting
275   *	@sk_sndtimeo: %SO_SNDTIMEO setting
276   *	@sk_rxhash: flow hash received from netif layer
277   *	@sk_txhash: computed flow hash for use on transmit
278   *	@sk_filter: socket filtering instructions
279   *	@sk_protinfo: private area, net family specific, when not using slab
280   *	@sk_timer: sock cleanup timer
281   *	@sk_stamp: time stamp of last packet received
282   *	@sk_tsflags: SO_TIMESTAMPING socket options
283   *	@sk_tskey: counter to disambiguate concurrent tstamp requests
284   *	@sk_socket: Identd and reporting IO signals
285   *	@sk_user_data: RPC layer private data
286   *	@sk_frag: cached page frag
287   *	@sk_peek_off: current peek_offset value
288   *	@sk_send_head: front of stuff to transmit
289   *	@sk_security: used by security modules
290   *	@sk_mark: generic packet mark
291   *	@sk_classid: this socket's cgroup classid
292   *	@sk_cgrp: this socket's cgroup-specific proto data
293   *	@sk_write_pending: a write to stream socket waits to start
294   *	@sk_state_change: callback to indicate change in the state of the sock
295   *	@sk_data_ready: callback to indicate there is data to be processed
296   *	@sk_write_space: callback to indicate there is bf sending space available
297   *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
298   *	@sk_backlog_rcv: callback to process the backlog
299   *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
300  */
301 struct sock {
302 	/*
303 	 * Now struct inet_timewait_sock also uses sock_common, so please just
304 	 * don't add nothing before this first member (__sk_common) --acme
305 	 */
306 	struct sock_common	__sk_common;
307 #define sk_node			__sk_common.skc_node
308 #define sk_nulls_node		__sk_common.skc_nulls_node
309 #define sk_refcnt		__sk_common.skc_refcnt
310 #define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
311 
312 #define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
313 #define sk_dontcopy_end		__sk_common.skc_dontcopy_end
314 #define sk_hash			__sk_common.skc_hash
315 #define sk_portpair		__sk_common.skc_portpair
316 #define sk_num			__sk_common.skc_num
317 #define sk_dport		__sk_common.skc_dport
318 #define sk_addrpair		__sk_common.skc_addrpair
319 #define sk_daddr		__sk_common.skc_daddr
320 #define sk_rcv_saddr		__sk_common.skc_rcv_saddr
321 #define sk_family		__sk_common.skc_family
322 #define sk_state		__sk_common.skc_state
323 #define sk_reuse		__sk_common.skc_reuse
324 #define sk_reuseport		__sk_common.skc_reuseport
325 #define sk_ipv6only		__sk_common.skc_ipv6only
326 #define sk_bound_dev_if		__sk_common.skc_bound_dev_if
327 #define sk_bind_node		__sk_common.skc_bind_node
328 #define sk_prot			__sk_common.skc_prot
329 #define sk_net			__sk_common.skc_net
330 #define sk_v6_daddr		__sk_common.skc_v6_daddr
331 #define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
332 
333 	socket_lock_t		sk_lock;
334 	struct sk_buff_head	sk_receive_queue;
335 	/*
336 	 * The backlog queue is special, it is always used with
337 	 * the per-socket spinlock held and requires low latency
338 	 * access. Therefore we special case it's implementation.
339 	 * Note : rmem_alloc is in this structure to fill a hole
340 	 * on 64bit arches, not because its logically part of
341 	 * backlog.
342 	 */
343 	struct {
344 		atomic_t	rmem_alloc;
345 		int		len;
346 		struct sk_buff	*head;
347 		struct sk_buff	*tail;
348 	} sk_backlog;
349 #define sk_rmem_alloc sk_backlog.rmem_alloc
350 	int			sk_forward_alloc;
351 #ifdef CONFIG_RPS
352 	__u32			sk_rxhash;
353 #endif
354 	__u32			sk_txhash;
355 #ifdef CONFIG_NET_RX_BUSY_POLL
356 	unsigned int		sk_napi_id;
357 	unsigned int		sk_ll_usec;
358 #endif
359 	atomic_t		sk_drops;
360 	int			sk_rcvbuf;
361 
362 	struct sk_filter __rcu	*sk_filter;
363 	struct socket_wq __rcu	*sk_wq;
364 
365 #ifdef CONFIG_XFRM
366 	struct xfrm_policy	*sk_policy[2];
367 #endif
368 	unsigned long 		sk_flags;
369 	struct dst_entry	*sk_rx_dst;
370 	struct dst_entry __rcu	*sk_dst_cache;
371 	spinlock_t		sk_dst_lock;
372 	atomic_t		sk_wmem_alloc;
373 	atomic_t		sk_omem_alloc;
374 	int			sk_sndbuf;
375 	struct sk_buff_head	sk_write_queue;
376 	kmemcheck_bitfield_begin(flags);
377 	unsigned int		sk_shutdown  : 2,
378 				sk_no_check_tx : 1,
379 				sk_no_check_rx : 1,
380 				sk_userlocks : 4,
381 				sk_protocol  : 8,
382 #define SK_PROTOCOL_MAX U8_MAX
383 				sk_type      : 16;
384 	kmemcheck_bitfield_end(flags);
385 	int			sk_wmem_queued;
386 	gfp_t			sk_allocation;
387 	u32			sk_pacing_rate; /* bytes per second */
388 	u32			sk_max_pacing_rate;
389 	netdev_features_t	sk_route_caps;
390 	netdev_features_t	sk_route_nocaps;
391 	int			sk_gso_type;
392 	unsigned int		sk_gso_max_size;
393 	u16			sk_gso_max_segs;
394 	int			sk_rcvlowat;
395 	unsigned long	        sk_lingertime;
396 	struct sk_buff_head	sk_error_queue;
397 	struct proto		*sk_prot_creator;
398 	rwlock_t		sk_callback_lock;
399 	int			sk_err,
400 				sk_err_soft;
401 	unsigned short		sk_ack_backlog;
402 	unsigned short		sk_max_ack_backlog;
403 	__u32			sk_priority;
404 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
405 	__u32			sk_cgrp_prioidx;
406 #endif
407 	struct pid		*sk_peer_pid;
408 	const struct cred	*sk_peer_cred;
409 	long			sk_rcvtimeo;
410 	long			sk_sndtimeo;
411 	void			*sk_protinfo;
412 	struct timer_list	sk_timer;
413 	ktime_t			sk_stamp;
414 	u16			sk_tsflags;
415 	u32			sk_tskey;
416 	struct socket		*sk_socket;
417 	void			*sk_user_data;
418 	struct page_frag	sk_frag;
419 	struct sk_buff		*sk_send_head;
420 	__s32			sk_peek_off;
421 	int			sk_write_pending;
422 #ifdef CONFIG_SECURITY
423 	void			*sk_security;
424 #endif
425 	__u32			sk_mark;
426 	kuid_t			sk_uid;
427 	u32			sk_classid;
428 	struct cg_proto		*sk_cgrp;
429 	void			(*sk_state_change)(struct sock *sk);
430 	void			(*sk_data_ready)(struct sock *sk);
431 	void			(*sk_write_space)(struct sock *sk);
432 	void			(*sk_error_report)(struct sock *sk);
433 	int			(*sk_backlog_rcv)(struct sock *sk,
434 						  struct sk_buff *skb);
435 	void                    (*sk_destruct)(struct sock *sk);
436 };
437 
438 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
439 
440 #define rcu_dereference_sk_user_data(sk)	rcu_dereference(__sk_user_data((sk)))
441 #define rcu_assign_sk_user_data(sk, ptr)	rcu_assign_pointer(__sk_user_data((sk)), ptr)
442 
443 /*
444  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
445  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
446  * on a socket means that the socket will reuse everybody else's port
447  * without looking at the other's sk_reuse value.
448  */
449 
450 #define SK_NO_REUSE	0
451 #define SK_CAN_REUSE	1
452 #define SK_FORCE_REUSE	2
453 
sk_peek_offset(struct sock * sk,int flags)454 static inline int sk_peek_offset(struct sock *sk, int flags)
455 {
456 	if ((flags & MSG_PEEK) && (sk->sk_peek_off >= 0))
457 		return sk->sk_peek_off;
458 	else
459 		return 0;
460 }
461 
sk_peek_offset_bwd(struct sock * sk,int val)462 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
463 {
464 	if (sk->sk_peek_off >= 0) {
465 		if (sk->sk_peek_off >= val)
466 			sk->sk_peek_off -= val;
467 		else
468 			sk->sk_peek_off = 0;
469 	}
470 }
471 
sk_peek_offset_fwd(struct sock * sk,int val)472 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
473 {
474 	if (sk->sk_peek_off >= 0)
475 		sk->sk_peek_off += val;
476 }
477 
478 /*
479  * Hashed lists helper routines
480  */
sk_entry(const struct hlist_node * node)481 static inline struct sock *sk_entry(const struct hlist_node *node)
482 {
483 	return hlist_entry(node, struct sock, sk_node);
484 }
485 
__sk_head(const struct hlist_head * head)486 static inline struct sock *__sk_head(const struct hlist_head *head)
487 {
488 	return hlist_entry(head->first, struct sock, sk_node);
489 }
490 
sk_head(const struct hlist_head * head)491 static inline struct sock *sk_head(const struct hlist_head *head)
492 {
493 	return hlist_empty(head) ? NULL : __sk_head(head);
494 }
495 
__sk_nulls_head(const struct hlist_nulls_head * head)496 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
497 {
498 	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
499 }
500 
sk_nulls_head(const struct hlist_nulls_head * head)501 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
502 {
503 	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
504 }
505 
sk_next(const struct sock * sk)506 static inline struct sock *sk_next(const struct sock *sk)
507 {
508 	return sk->sk_node.next ?
509 		hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
510 }
511 
sk_nulls_next(const struct sock * sk)512 static inline struct sock *sk_nulls_next(const struct sock *sk)
513 {
514 	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
515 		hlist_nulls_entry(sk->sk_nulls_node.next,
516 				  struct sock, sk_nulls_node) :
517 		NULL;
518 }
519 
sk_unhashed(const struct sock * sk)520 static inline bool sk_unhashed(const struct sock *sk)
521 {
522 	return hlist_unhashed(&sk->sk_node);
523 }
524 
sk_hashed(const struct sock * sk)525 static inline bool sk_hashed(const struct sock *sk)
526 {
527 	return !sk_unhashed(sk);
528 }
529 
sk_node_init(struct hlist_node * node)530 static inline void sk_node_init(struct hlist_node *node)
531 {
532 	node->pprev = NULL;
533 }
534 
sk_nulls_node_init(struct hlist_nulls_node * node)535 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
536 {
537 	node->pprev = NULL;
538 }
539 
__sk_del_node(struct sock * sk)540 static inline void __sk_del_node(struct sock *sk)
541 {
542 	__hlist_del(&sk->sk_node);
543 }
544 
545 /* NB: equivalent to hlist_del_init_rcu */
__sk_del_node_init(struct sock * sk)546 static inline bool __sk_del_node_init(struct sock *sk)
547 {
548 	if (sk_hashed(sk)) {
549 		__sk_del_node(sk);
550 		sk_node_init(&sk->sk_node);
551 		return true;
552 	}
553 	return false;
554 }
555 
556 /* Grab socket reference count. This operation is valid only
557    when sk is ALREADY grabbed f.e. it is found in hash table
558    or a list and the lookup is made under lock preventing hash table
559    modifications.
560  */
561 
sock_hold(struct sock * sk)562 static inline void sock_hold(struct sock *sk)
563 {
564 	atomic_inc(&sk->sk_refcnt);
565 }
566 
567 /* Ungrab socket in the context, which assumes that socket refcnt
568    cannot hit zero, f.e. it is true in context of any socketcall.
569  */
__sock_put(struct sock * sk)570 static inline void __sock_put(struct sock *sk)
571 {
572 	atomic_dec(&sk->sk_refcnt);
573 }
574 
sk_del_node_init(struct sock * sk)575 static inline bool sk_del_node_init(struct sock *sk)
576 {
577 	bool rc = __sk_del_node_init(sk);
578 
579 	if (rc) {
580 		/* paranoid for a while -acme */
581 		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
582 		__sock_put(sk);
583 	}
584 	return rc;
585 }
586 #define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
587 
__sk_nulls_del_node_init_rcu(struct sock * sk)588 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
589 {
590 	if (sk_hashed(sk)) {
591 		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
592 		return true;
593 	}
594 	return false;
595 }
596 
sk_nulls_del_node_init_rcu(struct sock * sk)597 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
598 {
599 	bool rc = __sk_nulls_del_node_init_rcu(sk);
600 
601 	if (rc) {
602 		/* paranoid for a while -acme */
603 		WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
604 		__sock_put(sk);
605 	}
606 	return rc;
607 }
608 
__sk_add_node(struct sock * sk,struct hlist_head * list)609 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
610 {
611 	hlist_add_head(&sk->sk_node, list);
612 }
613 
sk_add_node(struct sock * sk,struct hlist_head * list)614 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
615 {
616 	sock_hold(sk);
617 	__sk_add_node(sk, list);
618 }
619 
sk_add_node_rcu(struct sock * sk,struct hlist_head * list)620 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
621 {
622 	sock_hold(sk);
623 	hlist_add_head_rcu(&sk->sk_node, list);
624 }
625 
__sk_nulls_add_node_rcu(struct sock * sk,struct hlist_nulls_head * list)626 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
627 {
628 	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
629 }
630 
sk_nulls_add_node_rcu(struct sock * sk,struct hlist_nulls_head * list)631 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
632 {
633 	sock_hold(sk);
634 	__sk_nulls_add_node_rcu(sk, list);
635 }
636 
__sk_del_bind_node(struct sock * sk)637 static inline void __sk_del_bind_node(struct sock *sk)
638 {
639 	__hlist_del(&sk->sk_bind_node);
640 }
641 
sk_add_bind_node(struct sock * sk,struct hlist_head * list)642 static inline void sk_add_bind_node(struct sock *sk,
643 					struct hlist_head *list)
644 {
645 	hlist_add_head(&sk->sk_bind_node, list);
646 }
647 
648 #define sk_for_each(__sk, list) \
649 	hlist_for_each_entry(__sk, list, sk_node)
650 #define sk_for_each_rcu(__sk, list) \
651 	hlist_for_each_entry_rcu(__sk, list, sk_node)
652 #define sk_nulls_for_each(__sk, node, list) \
653 	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
654 #define sk_nulls_for_each_rcu(__sk, node, list) \
655 	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
656 #define sk_for_each_from(__sk) \
657 	hlist_for_each_entry_from(__sk, sk_node)
658 #define sk_nulls_for_each_from(__sk, node) \
659 	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
660 		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
661 #define sk_for_each_safe(__sk, tmp, list) \
662 	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
663 #define sk_for_each_bound(__sk, list) \
664 	hlist_for_each_entry(__sk, list, sk_bind_node)
665 
666 /**
667  * sk_nulls_for_each_entry_offset - iterate over a list at a given struct offset
668  * @tpos:	the type * to use as a loop cursor.
669  * @pos:	the &struct hlist_node to use as a loop cursor.
670  * @head:	the head for your list.
671  * @offset:	offset of hlist_node within the struct.
672  *
673  */
674 #define sk_nulls_for_each_entry_offset(tpos, pos, head, offset)		       \
675 	for (pos = (head)->first;					       \
676 	     (!is_a_nulls(pos)) &&					       \
677 		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
678 	     pos = pos->next)
679 
sk_user_ns(struct sock * sk)680 static inline struct user_namespace *sk_user_ns(struct sock *sk)
681 {
682 	/* Careful only use this in a context where these parameters
683 	 * can not change and must all be valid, such as recvmsg from
684 	 * userspace.
685 	 */
686 	return sk->sk_socket->file->f_cred->user_ns;
687 }
688 
689 /* Sock flags */
690 enum sock_flags {
691 	SOCK_DEAD,
692 	SOCK_DONE,
693 	SOCK_URGINLINE,
694 	SOCK_KEEPOPEN,
695 	SOCK_LINGER,
696 	SOCK_DESTROY,
697 	SOCK_BROADCAST,
698 	SOCK_TIMESTAMP,
699 	SOCK_ZAPPED,
700 	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
701 	SOCK_DBG, /* %SO_DEBUG setting */
702 	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
703 	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
704 	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
705 	SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
706 	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
707 	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
708 	SOCK_FASYNC, /* fasync() active */
709 	SOCK_RXQ_OVFL,
710 	SOCK_ZEROCOPY, /* buffers from userspace */
711 	SOCK_WIFI_STATUS, /* push wifi status to userspace */
712 	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
713 		     * Will use last 4 bytes of packet sent from
714 		     * user-space instead.
715 		     */
716 	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
717 	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
718 };
719 
720 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
721 
sock_copy_flags(struct sock * nsk,struct sock * osk)722 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
723 {
724 	nsk->sk_flags = osk->sk_flags;
725 }
726 
sock_set_flag(struct sock * sk,enum sock_flags flag)727 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
728 {
729 	__set_bit(flag, &sk->sk_flags);
730 }
731 
sock_reset_flag(struct sock * sk,enum sock_flags flag)732 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
733 {
734 	__clear_bit(flag, &sk->sk_flags);
735 }
736 
sock_flag(const struct sock * sk,enum sock_flags flag)737 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
738 {
739 	return test_bit(flag, &sk->sk_flags);
740 }
741 
742 #ifdef CONFIG_NET
743 extern struct static_key memalloc_socks;
sk_memalloc_socks(void)744 static inline int sk_memalloc_socks(void)
745 {
746 	return static_key_false(&memalloc_socks);
747 }
748 #else
749 
sk_memalloc_socks(void)750 static inline int sk_memalloc_socks(void)
751 {
752 	return 0;
753 }
754 
755 #endif
756 
sk_gfp_atomic(struct sock * sk,gfp_t gfp_mask)757 static inline gfp_t sk_gfp_atomic(struct sock *sk, gfp_t gfp_mask)
758 {
759 	return GFP_ATOMIC | (sk->sk_allocation & __GFP_MEMALLOC);
760 }
761 
sk_acceptq_removed(struct sock * sk)762 static inline void sk_acceptq_removed(struct sock *sk)
763 {
764 	sk->sk_ack_backlog--;
765 }
766 
sk_acceptq_added(struct sock * sk)767 static inline void sk_acceptq_added(struct sock *sk)
768 {
769 	sk->sk_ack_backlog++;
770 }
771 
sk_acceptq_is_full(const struct sock * sk)772 static inline bool sk_acceptq_is_full(const struct sock *sk)
773 {
774 	return sk->sk_ack_backlog > sk->sk_max_ack_backlog;
775 }
776 
777 /*
778  * Compute minimal free write space needed to queue new packets.
779  */
sk_stream_min_wspace(const struct sock * sk)780 static inline int sk_stream_min_wspace(const struct sock *sk)
781 {
782 	return sk->sk_wmem_queued >> 1;
783 }
784 
sk_stream_wspace(const struct sock * sk)785 static inline int sk_stream_wspace(const struct sock *sk)
786 {
787 	return sk->sk_sndbuf - sk->sk_wmem_queued;
788 }
789 
790 void sk_stream_write_space(struct sock *sk);
791 
792 /* OOB backlog add */
__sk_add_backlog(struct sock * sk,struct sk_buff * skb)793 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
794 {
795 	/* dont let skb dst not refcounted, we are going to leave rcu lock */
796 	skb_dst_force_safe(skb);
797 
798 	if (!sk->sk_backlog.tail)
799 		sk->sk_backlog.head = skb;
800 	else
801 		sk->sk_backlog.tail->next = skb;
802 
803 	sk->sk_backlog.tail = skb;
804 	skb->next = NULL;
805 }
806 
807 /*
808  * Take into account size of receive queue and backlog queue
809  * Do not take into account this skb truesize,
810  * to allow even a single big packet to come.
811  */
sk_rcvqueues_full(const struct sock * sk,unsigned int limit)812 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
813 {
814 	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
815 
816 	return qsize > limit;
817 }
818 
819 /* The per-socket spinlock must be held here. */
sk_add_backlog(struct sock * sk,struct sk_buff * skb,unsigned int limit)820 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
821 					      unsigned int limit)
822 {
823 	if (sk_rcvqueues_full(sk, limit))
824 		return -ENOBUFS;
825 
826 	/*
827 	 * If the skb was allocated from pfmemalloc reserves, only
828 	 * allow SOCK_MEMALLOC sockets to use it as this socket is
829 	 * helping free memory
830 	 */
831 	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
832 		return -ENOMEM;
833 
834 	__sk_add_backlog(sk, skb);
835 	sk->sk_backlog.len += skb->truesize;
836 	return 0;
837 }
838 
839 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
840 
sk_backlog_rcv(struct sock * sk,struct sk_buff * skb)841 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
842 {
843 	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
844 		return __sk_backlog_rcv(sk, skb);
845 
846 	return sk->sk_backlog_rcv(sk, skb);
847 }
848 
sock_rps_record_flow_hash(__u32 hash)849 static inline void sock_rps_record_flow_hash(__u32 hash)
850 {
851 #ifdef CONFIG_RPS
852 	struct rps_sock_flow_table *sock_flow_table;
853 
854 	rcu_read_lock();
855 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
856 	rps_record_sock_flow(sock_flow_table, hash);
857 	rcu_read_unlock();
858 #endif
859 }
860 
sock_rps_reset_flow_hash(__u32 hash)861 static inline void sock_rps_reset_flow_hash(__u32 hash)
862 {
863 #ifdef CONFIG_RPS
864 	struct rps_sock_flow_table *sock_flow_table;
865 
866 	rcu_read_lock();
867 	sock_flow_table = rcu_dereference(rps_sock_flow_table);
868 	rps_reset_sock_flow(sock_flow_table, hash);
869 	rcu_read_unlock();
870 #endif
871 }
872 
sock_rps_record_flow(const struct sock * sk)873 static inline void sock_rps_record_flow(const struct sock *sk)
874 {
875 #ifdef CONFIG_RPS
876 	sock_rps_record_flow_hash(sk->sk_rxhash);
877 #endif
878 }
879 
sock_rps_reset_flow(const struct sock * sk)880 static inline void sock_rps_reset_flow(const struct sock *sk)
881 {
882 #ifdef CONFIG_RPS
883 	sock_rps_reset_flow_hash(sk->sk_rxhash);
884 #endif
885 }
886 
sock_rps_save_rxhash(struct sock * sk,const struct sk_buff * skb)887 static inline void sock_rps_save_rxhash(struct sock *sk,
888 					const struct sk_buff *skb)
889 {
890 #ifdef CONFIG_RPS
891 	if (unlikely(sk->sk_rxhash != skb->hash)) {
892 		sock_rps_reset_flow(sk);
893 		sk->sk_rxhash = skb->hash;
894 	}
895 #endif
896 }
897 
sock_rps_reset_rxhash(struct sock * sk)898 static inline void sock_rps_reset_rxhash(struct sock *sk)
899 {
900 #ifdef CONFIG_RPS
901 	sock_rps_reset_flow(sk);
902 	sk->sk_rxhash = 0;
903 #endif
904 }
905 
906 #define sk_wait_event(__sk, __timeo, __condition)			\
907 	({	int __rc;						\
908 		release_sock(__sk);					\
909 		__rc = __condition;					\
910 		if (!__rc) {						\
911 			*(__timeo) = schedule_timeout(*(__timeo));	\
912 		}							\
913 		lock_sock(__sk);					\
914 		__rc = __condition;					\
915 		__rc;							\
916 	})
917 
918 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
919 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
920 void sk_stream_wait_close(struct sock *sk, long timeo_p);
921 int sk_stream_error(struct sock *sk, int flags, int err);
922 void sk_stream_kill_queues(struct sock *sk);
923 void sk_set_memalloc(struct sock *sk);
924 void sk_clear_memalloc(struct sock *sk);
925 
926 int sk_wait_data(struct sock *sk, long *timeo);
927 
928 struct request_sock_ops;
929 struct timewait_sock_ops;
930 struct inet_hashinfo;
931 struct raw_hashinfo;
932 struct module;
933 
934 /*
935  * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
936  * un-modified. Special care is taken when initializing object to zero.
937  */
sk_prot_clear_nulls(struct sock * sk,int size)938 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
939 {
940 	if (offsetof(struct sock, sk_node.next) != 0)
941 		memset(sk, 0, offsetof(struct sock, sk_node.next));
942 	memset(&sk->sk_node.pprev, 0,
943 	       size - offsetof(struct sock, sk_node.pprev));
944 }
945 
946 /* Networking protocol blocks we attach to sockets.
947  * socket layer -> transport layer interface
948  * transport -> network interface is defined by struct inet_proto
949  */
950 struct proto {
951 	void			(*close)(struct sock *sk,
952 					long timeout);
953 	int			(*connect)(struct sock *sk,
954 					struct sockaddr *uaddr,
955 					int addr_len);
956 	int			(*disconnect)(struct sock *sk, int flags);
957 
958 	struct sock *		(*accept)(struct sock *sk, int flags, int *err);
959 
960 	int			(*ioctl)(struct sock *sk, int cmd,
961 					 unsigned long arg);
962 	int			(*init)(struct sock *sk);
963 	void			(*destroy)(struct sock *sk);
964 	void			(*shutdown)(struct sock *sk, int how);
965 	int			(*setsockopt)(struct sock *sk, int level,
966 					int optname, char __user *optval,
967 					unsigned int optlen);
968 	int			(*getsockopt)(struct sock *sk, int level,
969 					int optname, char __user *optval,
970 					int __user *option);
971 #ifdef CONFIG_COMPAT
972 	int			(*compat_setsockopt)(struct sock *sk,
973 					int level,
974 					int optname, char __user *optval,
975 					unsigned int optlen);
976 	int			(*compat_getsockopt)(struct sock *sk,
977 					int level,
978 					int optname, char __user *optval,
979 					int __user *option);
980 	int			(*compat_ioctl)(struct sock *sk,
981 					unsigned int cmd, unsigned long arg);
982 #endif
983 	int			(*sendmsg)(struct kiocb *iocb, struct sock *sk,
984 					   struct msghdr *msg, size_t len);
985 	int			(*recvmsg)(struct kiocb *iocb, struct sock *sk,
986 					   struct msghdr *msg,
987 					   size_t len, int noblock, int flags,
988 					   int *addr_len);
989 	int			(*sendpage)(struct sock *sk, struct page *page,
990 					int offset, size_t size, int flags);
991 	int			(*bind)(struct sock *sk,
992 					struct sockaddr *uaddr, int addr_len);
993 
994 	int			(*backlog_rcv) (struct sock *sk,
995 						struct sk_buff *skb);
996 
997 	void		(*release_cb)(struct sock *sk);
998 
999 	/* Keeping track of sk's, looking them up, and port selection methods. */
1000 	void			(*hash)(struct sock *sk);
1001 	void			(*unhash)(struct sock *sk);
1002 	void			(*rehash)(struct sock *sk);
1003 	int			(*get_port)(struct sock *sk, unsigned short snum);
1004 	void			(*clear_sk)(struct sock *sk, int size);
1005 
1006 	/* Keeping track of sockets in use */
1007 #ifdef CONFIG_PROC_FS
1008 	unsigned int		inuse_idx;
1009 #endif
1010 
1011 	bool			(*stream_memory_free)(const struct sock *sk);
1012 	/* Memory pressure */
1013 	void			(*enter_memory_pressure)(struct sock *sk);
1014 	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
1015 	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
1016 	/*
1017 	 * Pressure flag: try to collapse.
1018 	 * Technical note: it is used by multiple contexts non atomically.
1019 	 * All the __sk_mem_schedule() is of this nature: accounting
1020 	 * is strict, actions are advisory and have some latency.
1021 	 */
1022 	int			*memory_pressure;
1023 	long			*sysctl_mem;
1024 	int			*sysctl_wmem;
1025 	int			*sysctl_rmem;
1026 	int			max_header;
1027 	bool			no_autobind;
1028 
1029 	struct kmem_cache	*slab;
1030 	unsigned int		obj_size;
1031 	int			slab_flags;
1032 
1033 	struct percpu_counter	*orphan_count;
1034 
1035 	struct request_sock_ops	*rsk_prot;
1036 	struct timewait_sock_ops *twsk_prot;
1037 
1038 	union {
1039 		struct inet_hashinfo	*hashinfo;
1040 		struct udp_table	*udp_table;
1041 		struct raw_hashinfo	*raw_hash;
1042 	} h;
1043 
1044 	struct module		*owner;
1045 
1046 	char			name[32];
1047 
1048 	struct list_head	node;
1049 #ifdef SOCK_REFCNT_DEBUG
1050 	atomic_t		socks;
1051 #endif
1052 #ifdef CONFIG_MEMCG_KMEM
1053 	/*
1054 	 * cgroup specific init/deinit functions. Called once for all
1055 	 * protocols that implement it, from cgroups populate function.
1056 	 * This function has to setup any files the protocol want to
1057 	 * appear in the kmem cgroup filesystem.
1058 	 */
1059 	int			(*init_cgroup)(struct mem_cgroup *memcg,
1060 					       struct cgroup_subsys *ss);
1061 	void			(*destroy_cgroup)(struct mem_cgroup *memcg);
1062 	struct cg_proto		*(*proto_cgroup)(struct mem_cgroup *memcg);
1063 #endif
1064 	int			(*diag_destroy)(struct sock *sk, int err);
1065 };
1066 
1067 /*
1068  * Bits in struct cg_proto.flags
1069  */
1070 enum cg_proto_flags {
1071 	/* Currently active and new sockets should be assigned to cgroups */
1072 	MEMCG_SOCK_ACTIVE,
1073 	/* It was ever activated; we must disarm static keys on destruction */
1074 	MEMCG_SOCK_ACTIVATED,
1075 };
1076 
1077 struct cg_proto {
1078 	struct res_counter	memory_allocated;	/* Current allocated memory. */
1079 	struct percpu_counter	sockets_allocated;	/* Current number of sockets. */
1080 	int			memory_pressure;
1081 	long			sysctl_mem[3];
1082 	unsigned long		flags;
1083 	/*
1084 	 * memcg field is used to find which memcg we belong directly
1085 	 * Each memcg struct can hold more than one cg_proto, so container_of
1086 	 * won't really cut.
1087 	 *
1088 	 * The elegant solution would be having an inverse function to
1089 	 * proto_cgroup in struct proto, but that means polluting the structure
1090 	 * for everybody, instead of just for memcg users.
1091 	 */
1092 	struct mem_cgroup	*memcg;
1093 };
1094 
1095 int proto_register(struct proto *prot, int alloc_slab);
1096 void proto_unregister(struct proto *prot);
1097 
memcg_proto_active(struct cg_proto * cg_proto)1098 static inline bool memcg_proto_active(struct cg_proto *cg_proto)
1099 {
1100 	return test_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
1101 }
1102 
memcg_proto_activated(struct cg_proto * cg_proto)1103 static inline bool memcg_proto_activated(struct cg_proto *cg_proto)
1104 {
1105 	return test_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags);
1106 }
1107 
1108 #ifdef SOCK_REFCNT_DEBUG
sk_refcnt_debug_inc(struct sock * sk)1109 static inline void sk_refcnt_debug_inc(struct sock *sk)
1110 {
1111 	atomic_inc(&sk->sk_prot->socks);
1112 }
1113 
sk_refcnt_debug_dec(struct sock * sk)1114 static inline void sk_refcnt_debug_dec(struct sock *sk)
1115 {
1116 	atomic_dec(&sk->sk_prot->socks);
1117 	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1118 	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1119 }
1120 
sk_refcnt_debug_release(const struct sock * sk)1121 static inline void sk_refcnt_debug_release(const struct sock *sk)
1122 {
1123 	if (atomic_read(&sk->sk_refcnt) != 1)
1124 		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1125 		       sk->sk_prot->name, sk, atomic_read(&sk->sk_refcnt));
1126 }
1127 #else /* SOCK_REFCNT_DEBUG */
1128 #define sk_refcnt_debug_inc(sk) do { } while (0)
1129 #define sk_refcnt_debug_dec(sk) do { } while (0)
1130 #define sk_refcnt_debug_release(sk) do { } while (0)
1131 #endif /* SOCK_REFCNT_DEBUG */
1132 
1133 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_NET)
1134 extern struct static_key memcg_socket_limit_enabled;
parent_cg_proto(struct proto * proto,struct cg_proto * cg_proto)1135 static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1136 					       struct cg_proto *cg_proto)
1137 {
1138 	return proto->proto_cgroup(parent_mem_cgroup(cg_proto->memcg));
1139 }
1140 #define mem_cgroup_sockets_enabled static_key_false(&memcg_socket_limit_enabled)
1141 #else
1142 #define mem_cgroup_sockets_enabled 0
parent_cg_proto(struct proto * proto,struct cg_proto * cg_proto)1143 static inline struct cg_proto *parent_cg_proto(struct proto *proto,
1144 					       struct cg_proto *cg_proto)
1145 {
1146 	return NULL;
1147 }
1148 #endif
1149 
sk_stream_memory_free(const struct sock * sk)1150 static inline bool sk_stream_memory_free(const struct sock *sk)
1151 {
1152 	if (sk->sk_wmem_queued >= sk->sk_sndbuf)
1153 		return false;
1154 
1155 	return sk->sk_prot->stream_memory_free ?
1156 		sk->sk_prot->stream_memory_free(sk) : true;
1157 }
1158 
sk_stream_is_writeable(const struct sock * sk)1159 static inline bool sk_stream_is_writeable(const struct sock *sk)
1160 {
1161 	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1162 	       sk_stream_memory_free(sk);
1163 }
1164 
1165 
sk_has_memory_pressure(const struct sock * sk)1166 static inline bool sk_has_memory_pressure(const struct sock *sk)
1167 {
1168 	return sk->sk_prot->memory_pressure != NULL;
1169 }
1170 
sk_under_memory_pressure(const struct sock * sk)1171 static inline bool sk_under_memory_pressure(const struct sock *sk)
1172 {
1173 	if (!sk->sk_prot->memory_pressure)
1174 		return false;
1175 
1176 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1177 		return !!sk->sk_cgrp->memory_pressure;
1178 
1179 	return !!*sk->sk_prot->memory_pressure;
1180 }
1181 
sk_leave_memory_pressure(struct sock * sk)1182 static inline void sk_leave_memory_pressure(struct sock *sk)
1183 {
1184 	int *memory_pressure = sk->sk_prot->memory_pressure;
1185 
1186 	if (!memory_pressure)
1187 		return;
1188 
1189 	if (*memory_pressure)
1190 		*memory_pressure = 0;
1191 
1192 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1193 		struct cg_proto *cg_proto = sk->sk_cgrp;
1194 		struct proto *prot = sk->sk_prot;
1195 
1196 		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1197 			cg_proto->memory_pressure = 0;
1198 	}
1199 
1200 }
1201 
sk_enter_memory_pressure(struct sock * sk)1202 static inline void sk_enter_memory_pressure(struct sock *sk)
1203 {
1204 	if (!sk->sk_prot->enter_memory_pressure)
1205 		return;
1206 
1207 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1208 		struct cg_proto *cg_proto = sk->sk_cgrp;
1209 		struct proto *prot = sk->sk_prot;
1210 
1211 		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1212 			cg_proto->memory_pressure = 1;
1213 	}
1214 
1215 	sk->sk_prot->enter_memory_pressure(sk);
1216 }
1217 
sk_prot_mem_limits(const struct sock * sk,int index)1218 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1219 {
1220 	long *prot = sk->sk_prot->sysctl_mem;
1221 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1222 		prot = sk->sk_cgrp->sysctl_mem;
1223 	return prot[index];
1224 }
1225 
memcg_memory_allocated_add(struct cg_proto * prot,unsigned long amt,int * parent_status)1226 static inline void memcg_memory_allocated_add(struct cg_proto *prot,
1227 					      unsigned long amt,
1228 					      int *parent_status)
1229 {
1230 	struct res_counter *fail;
1231 	int ret;
1232 
1233 	ret = res_counter_charge_nofail(&prot->memory_allocated,
1234 					amt << PAGE_SHIFT, &fail);
1235 	if (ret < 0)
1236 		*parent_status = OVER_LIMIT;
1237 }
1238 
memcg_memory_allocated_sub(struct cg_proto * prot,unsigned long amt)1239 static inline void memcg_memory_allocated_sub(struct cg_proto *prot,
1240 					      unsigned long amt)
1241 {
1242 	res_counter_uncharge(&prot->memory_allocated, amt << PAGE_SHIFT);
1243 }
1244 
memcg_memory_allocated_read(struct cg_proto * prot)1245 static inline u64 memcg_memory_allocated_read(struct cg_proto *prot)
1246 {
1247 	u64 ret;
1248 	ret = res_counter_read_u64(&prot->memory_allocated, RES_USAGE);
1249 	return ret >> PAGE_SHIFT;
1250 }
1251 
1252 static inline long
sk_memory_allocated(const struct sock * sk)1253 sk_memory_allocated(const struct sock *sk)
1254 {
1255 	struct proto *prot = sk->sk_prot;
1256 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1257 		return memcg_memory_allocated_read(sk->sk_cgrp);
1258 
1259 	return atomic_long_read(prot->memory_allocated);
1260 }
1261 
1262 static inline long
sk_memory_allocated_add(struct sock * sk,int amt,int * parent_status)1263 sk_memory_allocated_add(struct sock *sk, int amt, int *parent_status)
1264 {
1265 	struct proto *prot = sk->sk_prot;
1266 
1267 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1268 		memcg_memory_allocated_add(sk->sk_cgrp, amt, parent_status);
1269 		/* update the root cgroup regardless */
1270 		atomic_long_add_return(amt, prot->memory_allocated);
1271 		return memcg_memory_allocated_read(sk->sk_cgrp);
1272 	}
1273 
1274 	return atomic_long_add_return(amt, prot->memory_allocated);
1275 }
1276 
1277 static inline void
sk_memory_allocated_sub(struct sock * sk,int amt)1278 sk_memory_allocated_sub(struct sock *sk, int amt)
1279 {
1280 	struct proto *prot = sk->sk_prot;
1281 
1282 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1283 		memcg_memory_allocated_sub(sk->sk_cgrp, amt);
1284 
1285 	atomic_long_sub(amt, prot->memory_allocated);
1286 }
1287 
sk_sockets_allocated_dec(struct sock * sk)1288 static inline void sk_sockets_allocated_dec(struct sock *sk)
1289 {
1290 	struct proto *prot = sk->sk_prot;
1291 
1292 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1293 		struct cg_proto *cg_proto = sk->sk_cgrp;
1294 
1295 		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1296 			percpu_counter_dec(&cg_proto->sockets_allocated);
1297 	}
1298 
1299 	percpu_counter_dec(prot->sockets_allocated);
1300 }
1301 
sk_sockets_allocated_inc(struct sock * sk)1302 static inline void sk_sockets_allocated_inc(struct sock *sk)
1303 {
1304 	struct proto *prot = sk->sk_prot;
1305 
1306 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp) {
1307 		struct cg_proto *cg_proto = sk->sk_cgrp;
1308 
1309 		for (; cg_proto; cg_proto = parent_cg_proto(prot, cg_proto))
1310 			percpu_counter_inc(&cg_proto->sockets_allocated);
1311 	}
1312 
1313 	percpu_counter_inc(prot->sockets_allocated);
1314 }
1315 
1316 static inline int
sk_sockets_allocated_read_positive(struct sock * sk)1317 sk_sockets_allocated_read_positive(struct sock *sk)
1318 {
1319 	struct proto *prot = sk->sk_prot;
1320 
1321 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1322 		return percpu_counter_read_positive(&sk->sk_cgrp->sockets_allocated);
1323 
1324 	return percpu_counter_read_positive(prot->sockets_allocated);
1325 }
1326 
1327 static inline int
proto_sockets_allocated_sum_positive(struct proto * prot)1328 proto_sockets_allocated_sum_positive(struct proto *prot)
1329 {
1330 	return percpu_counter_sum_positive(prot->sockets_allocated);
1331 }
1332 
1333 static inline long
proto_memory_allocated(struct proto * prot)1334 proto_memory_allocated(struct proto *prot)
1335 {
1336 	return atomic_long_read(prot->memory_allocated);
1337 }
1338 
1339 static inline bool
proto_memory_pressure(struct proto * prot)1340 proto_memory_pressure(struct proto *prot)
1341 {
1342 	if (!prot->memory_pressure)
1343 		return false;
1344 	return !!*prot->memory_pressure;
1345 }
1346 
1347 
1348 #ifdef CONFIG_PROC_FS
1349 /* Called with local bh disabled */
1350 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1351 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1352 #else
sock_prot_inuse_add(struct net * net,struct proto * prot,int inc)1353 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1354 		int inc)
1355 {
1356 }
1357 #endif
1358 
1359 
1360 /* With per-bucket locks this operation is not-atomic, so that
1361  * this version is not worse.
1362  */
__sk_prot_rehash(struct sock * sk)1363 static inline void __sk_prot_rehash(struct sock *sk)
1364 {
1365 	sk->sk_prot->unhash(sk);
1366 	sk->sk_prot->hash(sk);
1367 }
1368 
1369 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size);
1370 
1371 /* About 10 seconds */
1372 #define SOCK_DESTROY_TIME (10*HZ)
1373 
1374 /* Sockets 0-1023 can't be bound to unless you are superuser */
1375 #define PROT_SOCK	1024
1376 
1377 #define SHUTDOWN_MASK	3
1378 #define RCV_SHUTDOWN	1
1379 #define SEND_SHUTDOWN	2
1380 
1381 #define SOCK_SNDBUF_LOCK	1
1382 #define SOCK_RCVBUF_LOCK	2
1383 #define SOCK_BINDADDR_LOCK	4
1384 #define SOCK_BINDPORT_LOCK	8
1385 
1386 /* sock_iocb: used to kick off async processing of socket ios */
1387 struct sock_iocb {
1388 	struct list_head	list;
1389 
1390 	int			flags;
1391 	int			size;
1392 	struct socket		*sock;
1393 	struct sock		*sk;
1394 	struct scm_cookie	*scm;
1395 	struct msghdr		*msg, async_msg;
1396 	struct kiocb		*kiocb;
1397 };
1398 
kiocb_to_siocb(struct kiocb * iocb)1399 static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb)
1400 {
1401 	return (struct sock_iocb *)iocb->private;
1402 }
1403 
siocb_to_kiocb(struct sock_iocb * si)1404 static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si)
1405 {
1406 	return si->kiocb;
1407 }
1408 
1409 struct socket_alloc {
1410 	struct socket socket;
1411 	struct inode vfs_inode;
1412 };
1413 
SOCKET_I(struct inode * inode)1414 static inline struct socket *SOCKET_I(struct inode *inode)
1415 {
1416 	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1417 }
1418 
SOCK_INODE(struct socket * socket)1419 static inline struct inode *SOCK_INODE(struct socket *socket)
1420 {
1421 	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1422 }
1423 
1424 /*
1425  * Functions for memory accounting
1426  */
1427 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1428 void __sk_mem_reclaim(struct sock *sk);
1429 
1430 #define SK_MEM_QUANTUM ((int)PAGE_SIZE)
1431 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1432 #define SK_MEM_SEND	0
1433 #define SK_MEM_RECV	1
1434 
sk_mem_pages(int amt)1435 static inline int sk_mem_pages(int amt)
1436 {
1437 	return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1438 }
1439 
sk_has_account(struct sock * sk)1440 static inline bool sk_has_account(struct sock *sk)
1441 {
1442 	/* return true if protocol supports memory accounting */
1443 	return !!sk->sk_prot->memory_allocated;
1444 }
1445 
sk_wmem_schedule(struct sock * sk,int size)1446 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1447 {
1448 	if (!sk_has_account(sk))
1449 		return true;
1450 	return size <= sk->sk_forward_alloc ||
1451 		__sk_mem_schedule(sk, size, SK_MEM_SEND);
1452 }
1453 
1454 static inline bool
sk_rmem_schedule(struct sock * sk,struct sk_buff * skb,int size)1455 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1456 {
1457 	if (!sk_has_account(sk))
1458 		return true;
1459 	return size<= sk->sk_forward_alloc ||
1460 		__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
1461 		skb_pfmemalloc(skb);
1462 }
1463 
sk_mem_reclaim(struct sock * sk)1464 static inline void sk_mem_reclaim(struct sock *sk)
1465 {
1466 	if (!sk_has_account(sk))
1467 		return;
1468 	if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1469 		__sk_mem_reclaim(sk);
1470 }
1471 
sk_mem_reclaim_partial(struct sock * sk)1472 static inline void sk_mem_reclaim_partial(struct sock *sk)
1473 {
1474 	if (!sk_has_account(sk))
1475 		return;
1476 	if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1477 		__sk_mem_reclaim(sk);
1478 }
1479 
sk_mem_charge(struct sock * sk,int size)1480 static inline void sk_mem_charge(struct sock *sk, int size)
1481 {
1482 	if (!sk_has_account(sk))
1483 		return;
1484 	sk->sk_forward_alloc -= size;
1485 }
1486 
sk_mem_uncharge(struct sock * sk,int size)1487 static inline void sk_mem_uncharge(struct sock *sk, int size)
1488 {
1489 	if (!sk_has_account(sk))
1490 		return;
1491 	sk->sk_forward_alloc += size;
1492 }
1493 
sk_wmem_free_skb(struct sock * sk,struct sk_buff * skb)1494 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1495 {
1496 	sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
1497 	sk->sk_wmem_queued -= skb->truesize;
1498 	sk_mem_uncharge(sk, skb->truesize);
1499 	__kfree_skb(skb);
1500 }
1501 
1502 /* Used by processes to "lock" a socket state, so that
1503  * interrupts and bottom half handlers won't change it
1504  * from under us. It essentially blocks any incoming
1505  * packets, so that we won't get any new data or any
1506  * packets that change the state of the socket.
1507  *
1508  * While locked, BH processing will add new packets to
1509  * the backlog queue.  This queue is processed by the
1510  * owner of the socket lock right before it is released.
1511  *
1512  * Since ~2.3.5 it is also exclusive sleep lock serializing
1513  * accesses from user process context.
1514  */
1515 #define sock_owned_by_user(sk)	((sk)->sk_lock.owned)
1516 
sock_release_ownership(struct sock * sk)1517 static inline void sock_release_ownership(struct sock *sk)
1518 {
1519 	sk->sk_lock.owned = 0;
1520 }
1521 
1522 /*
1523  * Macro so as to not evaluate some arguments when
1524  * lockdep is not enabled.
1525  *
1526  * Mark both the sk_lock and the sk_lock.slock as a
1527  * per-address-family lock class.
1528  */
1529 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
1530 do {									\
1531 	sk->sk_lock.owned = 0;						\
1532 	init_waitqueue_head(&sk->sk_lock.wq);				\
1533 	spin_lock_init(&(sk)->sk_lock.slock);				\
1534 	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
1535 			sizeof((sk)->sk_lock));				\
1536 	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
1537 				(skey), (sname));				\
1538 	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
1539 } while (0)
1540 
1541 void lock_sock_nested(struct sock *sk, int subclass);
1542 
lock_sock(struct sock * sk)1543 static inline void lock_sock(struct sock *sk)
1544 {
1545 	lock_sock_nested(sk, 0);
1546 }
1547 
1548 void release_sock(struct sock *sk);
1549 
1550 /* BH context may only use the following locking interface. */
1551 #define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
1552 #define bh_lock_sock_nested(__sk) \
1553 				spin_lock_nested(&((__sk)->sk_lock.slock), \
1554 				SINGLE_DEPTH_NESTING)
1555 #define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
1556 
1557 bool lock_sock_fast(struct sock *sk);
1558 /**
1559  * unlock_sock_fast - complement of lock_sock_fast
1560  * @sk: socket
1561  * @slow: slow mode
1562  *
1563  * fast unlock socket for user context.
1564  * If slow mode is on, we call regular release_sock()
1565  */
unlock_sock_fast(struct sock * sk,bool slow)1566 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1567 {
1568 	if (slow)
1569 		release_sock(sk);
1570 	else
1571 		spin_unlock_bh(&sk->sk_lock.slock);
1572 }
1573 
1574 
1575 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1576 		      struct proto *prot);
1577 void sk_free(struct sock *sk);
1578 void sk_release_kernel(struct sock *sk);
1579 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1580 
1581 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1582 			     gfp_t priority);
1583 void sock_wfree(struct sk_buff *skb);
1584 void skb_orphan_partial(struct sk_buff *skb);
1585 void sock_rfree(struct sk_buff *skb);
1586 void sock_efree(struct sk_buff *skb);
1587 #ifdef CONFIG_INET
1588 void sock_edemux(struct sk_buff *skb);
1589 #else
1590 #define sock_edemux(skb) sock_efree(skb)
1591 #endif
1592 
1593 int sock_setsockopt(struct socket *sock, int level, int op,
1594 		    char __user *optval, unsigned int optlen);
1595 
1596 int sock_getsockopt(struct socket *sock, int level, int op,
1597 		    char __user *optval, int __user *optlen);
1598 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1599 				    int noblock, int *errcode);
1600 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1601 				     unsigned long data_len, int noblock,
1602 				     int *errcode, int max_page_order);
1603 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1604 void sock_kfree_s(struct sock *sk, void *mem, int size);
1605 void sk_send_sigurg(struct sock *sk);
1606 
1607 /*
1608  * Functions to fill in entries in struct proto_ops when a protocol
1609  * does not implement a particular function.
1610  */
1611 int sock_no_bind(struct socket *, struct sockaddr *, int);
1612 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1613 int sock_no_socketpair(struct socket *, struct socket *);
1614 int sock_no_accept(struct socket *, struct socket *, int);
1615 int sock_no_getname(struct socket *, struct sockaddr *, int *, int);
1616 unsigned int sock_no_poll(struct file *, struct socket *,
1617 			  struct poll_table_struct *);
1618 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1619 int sock_no_listen(struct socket *, int);
1620 int sock_no_shutdown(struct socket *, int);
1621 int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
1622 int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
1623 int sock_no_sendmsg(struct kiocb *, struct socket *, struct msghdr *, size_t);
1624 int sock_no_recvmsg(struct kiocb *, struct socket *, struct msghdr *, size_t,
1625 		    int);
1626 int sock_no_mmap(struct file *file, struct socket *sock,
1627 		 struct vm_area_struct *vma);
1628 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1629 			 size_t size, int flags);
1630 
1631 /*
1632  * Functions to fill in entries in struct proto_ops when a protocol
1633  * uses the inet style.
1634  */
1635 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1636 				  char __user *optval, int __user *optlen);
1637 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1638 			       struct msghdr *msg, size_t size, int flags);
1639 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1640 				  char __user *optval, unsigned int optlen);
1641 int compat_sock_common_getsockopt(struct socket *sock, int level,
1642 		int optname, char __user *optval, int __user *optlen);
1643 int compat_sock_common_setsockopt(struct socket *sock, int level,
1644 		int optname, char __user *optval, unsigned int optlen);
1645 
1646 void sk_common_release(struct sock *sk);
1647 
1648 /*
1649  *	Default socket callbacks and setup code
1650  */
1651 
1652 /* Initialise core socket variables */
1653 void sock_init_data(struct socket *sock, struct sock *sk);
1654 
1655 /*
1656  * Socket reference counting postulates.
1657  *
1658  * * Each user of socket SHOULD hold a reference count.
1659  * * Each access point to socket (an hash table bucket, reference from a list,
1660  *   running timer, skb in flight MUST hold a reference count.
1661  * * When reference count hits 0, it means it will never increase back.
1662  * * When reference count hits 0, it means that no references from
1663  *   outside exist to this socket and current process on current CPU
1664  *   is last user and may/should destroy this socket.
1665  * * sk_free is called from any context: process, BH, IRQ. When
1666  *   it is called, socket has no references from outside -> sk_free
1667  *   may release descendant resources allocated by the socket, but
1668  *   to the time when it is called, socket is NOT referenced by any
1669  *   hash tables, lists etc.
1670  * * Packets, delivered from outside (from network or from another process)
1671  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
1672  *   when they sit in queue. Otherwise, packets will leak to hole, when
1673  *   socket is looked up by one cpu and unhasing is made by another CPU.
1674  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
1675  *   (leak to backlog). Packet socket does all the processing inside
1676  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1677  *   use separate SMP lock, so that they are prone too.
1678  */
1679 
1680 /* Ungrab socket and destroy it, if it was the last reference. */
sock_put(struct sock * sk)1681 static inline void sock_put(struct sock *sk)
1682 {
1683 	if (atomic_dec_and_test(&sk->sk_refcnt))
1684 		sk_free(sk);
1685 }
1686 /* Generic version of sock_put(), dealing with all sockets
1687  * (TCP_TIMEWAIT, ESTABLISHED...)
1688  */
1689 void sock_gen_put(struct sock *sk);
1690 
1691 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested);
1692 
sk_tx_queue_set(struct sock * sk,int tx_queue)1693 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1694 {
1695 	sk->sk_tx_queue_mapping = tx_queue;
1696 }
1697 
sk_tx_queue_clear(struct sock * sk)1698 static inline void sk_tx_queue_clear(struct sock *sk)
1699 {
1700 	sk->sk_tx_queue_mapping = -1;
1701 }
1702 
sk_tx_queue_get(const struct sock * sk)1703 static inline int sk_tx_queue_get(const struct sock *sk)
1704 {
1705 	return sk ? sk->sk_tx_queue_mapping : -1;
1706 }
1707 
sk_set_socket(struct sock * sk,struct socket * sock)1708 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1709 {
1710 	sk_tx_queue_clear(sk);
1711 	sk->sk_socket = sock;
1712 }
1713 
sk_sleep(struct sock * sk)1714 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1715 {
1716 	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1717 	return &rcu_dereference_raw(sk->sk_wq)->wait;
1718 }
1719 /* Detach socket from process context.
1720  * Announce socket dead, detach it from wait queue and inode.
1721  * Note that parent inode held reference count on this struct sock,
1722  * we do not release it in this function, because protocol
1723  * probably wants some additional cleanups or even continuing
1724  * to work with this socket (TCP).
1725  */
sock_orphan(struct sock * sk)1726 static inline void sock_orphan(struct sock *sk)
1727 {
1728 	write_lock_bh(&sk->sk_callback_lock);
1729 	sock_set_flag(sk, SOCK_DEAD);
1730 	sk_set_socket(sk, NULL);
1731 	sk->sk_wq  = NULL;
1732 	write_unlock_bh(&sk->sk_callback_lock);
1733 }
1734 
sock_graft(struct sock * sk,struct socket * parent)1735 static inline void sock_graft(struct sock *sk, struct socket *parent)
1736 {
1737 	write_lock_bh(&sk->sk_callback_lock);
1738 	sk->sk_wq = parent->wq;
1739 	parent->sk = sk;
1740 	sk_set_socket(sk, parent);
1741 	sk->sk_uid = SOCK_INODE(parent)->i_uid;
1742 	security_sock_graft(sk, parent);
1743 	write_unlock_bh(&sk->sk_callback_lock);
1744 }
1745 
1746 kuid_t sock_i_uid(struct sock *sk);
1747 unsigned long sock_i_ino(struct sock *sk);
1748 
sock_net_uid(const struct net * net,const struct sock * sk)1749 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1750 {
1751 	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1752 }
1753 
1754 static inline struct dst_entry *
__sk_dst_get(struct sock * sk)1755 __sk_dst_get(struct sock *sk)
1756 {
1757 	return rcu_dereference_check(sk->sk_dst_cache, sock_owned_by_user(sk) ||
1758 						       lockdep_is_held(&sk->sk_lock.slock));
1759 }
1760 
1761 static inline struct dst_entry *
sk_dst_get(struct sock * sk)1762 sk_dst_get(struct sock *sk)
1763 {
1764 	struct dst_entry *dst;
1765 
1766 	rcu_read_lock();
1767 	dst = rcu_dereference(sk->sk_dst_cache);
1768 	if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1769 		dst = NULL;
1770 	rcu_read_unlock();
1771 	return dst;
1772 }
1773 
dst_negative_advice(struct sock * sk)1774 static inline void dst_negative_advice(struct sock *sk)
1775 {
1776 	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1777 
1778 	if (dst && dst->ops->negative_advice) {
1779 		ndst = dst->ops->negative_advice(dst);
1780 
1781 		if (ndst != dst) {
1782 			rcu_assign_pointer(sk->sk_dst_cache, ndst);
1783 			sk_tx_queue_clear(sk);
1784 		}
1785 	}
1786 }
1787 
1788 static inline void
__sk_dst_set(struct sock * sk,struct dst_entry * dst)1789 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
1790 {
1791 	struct dst_entry *old_dst;
1792 
1793 	sk_tx_queue_clear(sk);
1794 	/*
1795 	 * This can be called while sk is owned by the caller only,
1796 	 * with no state that can be checked in a rcu_dereference_check() cond
1797 	 */
1798 	old_dst = rcu_dereference_raw(sk->sk_dst_cache);
1799 	rcu_assign_pointer(sk->sk_dst_cache, dst);
1800 	dst_release(old_dst);
1801 }
1802 
1803 static inline void
sk_dst_set(struct sock * sk,struct dst_entry * dst)1804 sk_dst_set(struct sock *sk, struct dst_entry *dst)
1805 {
1806 	struct dst_entry *old_dst;
1807 
1808 	sk_tx_queue_clear(sk);
1809 	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
1810 	dst_release(old_dst);
1811 }
1812 
1813 static inline void
__sk_dst_reset(struct sock * sk)1814 __sk_dst_reset(struct sock *sk)
1815 {
1816 	__sk_dst_set(sk, NULL);
1817 }
1818 
1819 static inline void
sk_dst_reset(struct sock * sk)1820 sk_dst_reset(struct sock *sk)
1821 {
1822 	sk_dst_set(sk, NULL);
1823 }
1824 
1825 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
1826 
1827 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
1828 
1829 bool sk_mc_loop(struct sock *sk);
1830 
sk_can_gso(const struct sock * sk)1831 static inline bool sk_can_gso(const struct sock *sk)
1832 {
1833 	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
1834 }
1835 
1836 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
1837 
sk_nocaps_add(struct sock * sk,netdev_features_t flags)1838 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
1839 {
1840 	sk->sk_route_nocaps |= flags;
1841 	sk->sk_route_caps &= ~flags;
1842 }
1843 
skb_do_copy_data_nocache(struct sock * sk,struct sk_buff * skb,char __user * from,char * to,int copy,int offset)1844 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
1845 					   char __user *from, char *to,
1846 					   int copy, int offset)
1847 {
1848 	if (skb->ip_summed == CHECKSUM_NONE) {
1849 		int err = 0;
1850 		__wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
1851 		if (err)
1852 			return err;
1853 		skb->csum = csum_block_add(skb->csum, csum, offset);
1854 	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
1855 		if (!access_ok(VERIFY_READ, from, copy) ||
1856 		    __copy_from_user_nocache(to, from, copy))
1857 			return -EFAULT;
1858 	} else if (copy_from_user(to, from, copy))
1859 		return -EFAULT;
1860 
1861 	return 0;
1862 }
1863 
skb_add_data_nocache(struct sock * sk,struct sk_buff * skb,char __user * from,int copy)1864 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
1865 				       char __user *from, int copy)
1866 {
1867 	int err, offset = skb->len;
1868 
1869 	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
1870 				       copy, offset);
1871 	if (err)
1872 		__skb_trim(skb, offset);
1873 
1874 	return err;
1875 }
1876 
skb_copy_to_page_nocache(struct sock * sk,char __user * from,struct sk_buff * skb,struct page * page,int off,int copy)1877 static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
1878 					   struct sk_buff *skb,
1879 					   struct page *page,
1880 					   int off, int copy)
1881 {
1882 	int err;
1883 
1884 	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
1885 				       copy, skb->len);
1886 	if (err)
1887 		return err;
1888 
1889 	skb->len	     += copy;
1890 	skb->data_len	     += copy;
1891 	skb->truesize	     += copy;
1892 	sk->sk_wmem_queued   += copy;
1893 	sk_mem_charge(sk, copy);
1894 	return 0;
1895 }
1896 
skb_copy_to_page(struct sock * sk,char __user * from,struct sk_buff * skb,struct page * page,int off,int copy)1897 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
1898 				   struct sk_buff *skb, struct page *page,
1899 				   int off, int copy)
1900 {
1901 	if (skb->ip_summed == CHECKSUM_NONE) {
1902 		int err = 0;
1903 		__wsum csum = csum_and_copy_from_user(from,
1904 						     page_address(page) + off,
1905 							    copy, 0, &err);
1906 		if (err)
1907 			return err;
1908 		skb->csum = csum_block_add(skb->csum, csum, skb->len);
1909 	} else if (copy_from_user(page_address(page) + off, from, copy))
1910 		return -EFAULT;
1911 
1912 	skb->len	     += copy;
1913 	skb->data_len	     += copy;
1914 	skb->truesize	     += copy;
1915 	sk->sk_wmem_queued   += copy;
1916 	sk_mem_charge(sk, copy);
1917 	return 0;
1918 }
1919 
1920 /**
1921  * sk_wmem_alloc_get - returns write allocations
1922  * @sk: socket
1923  *
1924  * Returns sk_wmem_alloc minus initial offset of one
1925  */
sk_wmem_alloc_get(const struct sock * sk)1926 static inline int sk_wmem_alloc_get(const struct sock *sk)
1927 {
1928 	return atomic_read(&sk->sk_wmem_alloc) - 1;
1929 }
1930 
1931 /**
1932  * sk_rmem_alloc_get - returns read allocations
1933  * @sk: socket
1934  *
1935  * Returns sk_rmem_alloc
1936  */
sk_rmem_alloc_get(const struct sock * sk)1937 static inline int sk_rmem_alloc_get(const struct sock *sk)
1938 {
1939 	return atomic_read(&sk->sk_rmem_alloc);
1940 }
1941 
1942 /**
1943  * sk_has_allocations - check if allocations are outstanding
1944  * @sk: socket
1945  *
1946  * Returns true if socket has write or read allocations
1947  */
sk_has_allocations(const struct sock * sk)1948 static inline bool sk_has_allocations(const struct sock *sk)
1949 {
1950 	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
1951 }
1952 
1953 /**
1954  * wq_has_sleeper - check if there are any waiting processes
1955  * @wq: struct socket_wq
1956  *
1957  * Returns true if socket_wq has waiting processes
1958  *
1959  * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory
1960  * barrier call. They were added due to the race found within the tcp code.
1961  *
1962  * Consider following tcp code paths:
1963  *
1964  * CPU1                  CPU2
1965  *
1966  * sys_select            receive packet
1967  *   ...                 ...
1968  *   __add_wait_queue    update tp->rcv_nxt
1969  *   ...                 ...
1970  *   tp->rcv_nxt check   sock_def_readable
1971  *   ...                 {
1972  *   schedule               rcu_read_lock();
1973  *                          wq = rcu_dereference(sk->sk_wq);
1974  *                          if (wq && waitqueue_active(&wq->wait))
1975  *                              wake_up_interruptible(&wq->wait)
1976  *                          ...
1977  *                       }
1978  *
1979  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
1980  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
1981  * could then endup calling schedule and sleep forever if there are no more
1982  * data on the socket.
1983  *
1984  */
wq_has_sleeper(struct socket_wq * wq)1985 static inline bool wq_has_sleeper(struct socket_wq *wq)
1986 {
1987 	/* We need to be sure we are in sync with the
1988 	 * add_wait_queue modifications to the wait queue.
1989 	 *
1990 	 * This memory barrier is paired in the sock_poll_wait.
1991 	 */
1992 	smp_mb();
1993 	return wq && waitqueue_active(&wq->wait);
1994 }
1995 
1996 /**
1997  * sock_poll_wait - place memory barrier behind the poll_wait call.
1998  * @filp:           file
1999  * @wait_address:   socket wait queue
2000  * @p:              poll_table
2001  *
2002  * See the comments in the wq_has_sleeper function.
2003  */
sock_poll_wait(struct file * filp,wait_queue_head_t * wait_address,poll_table * p)2004 static inline void sock_poll_wait(struct file *filp,
2005 		wait_queue_head_t *wait_address, poll_table *p)
2006 {
2007 	if (!poll_does_not_wait(p) && wait_address) {
2008 		poll_wait(filp, wait_address, p);
2009 		/* We need to be sure we are in sync with the
2010 		 * socket flags modification.
2011 		 *
2012 		 * This memory barrier is paired in the wq_has_sleeper.
2013 		 */
2014 		smp_mb();
2015 	}
2016 }
2017 
skb_set_hash_from_sk(struct sk_buff * skb,struct sock * sk)2018 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2019 {
2020 	if (sk->sk_txhash) {
2021 		skb->l4_hash = 1;
2022 		skb->hash = sk->sk_txhash;
2023 	}
2024 }
2025 
2026 /*
2027  *	Queue a received datagram if it will fit. Stream and sequenced
2028  *	protocols can't normally use this as they need to fit buffers in
2029  *	and play with them.
2030  *
2031  *	Inlined as it's very short and called for pretty much every
2032  *	packet ever received.
2033  */
2034 
skb_set_owner_w(struct sk_buff * skb,struct sock * sk)2035 static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
2036 {
2037 	skb_orphan(skb);
2038 	skb->sk = sk;
2039 	skb->destructor = sock_wfree;
2040 	skb_set_hash_from_sk(skb, sk);
2041 	/*
2042 	 * We used to take a refcount on sk, but following operation
2043 	 * is enough to guarantee sk_free() wont free this sock until
2044 	 * all in-flight packets are completed
2045 	 */
2046 	atomic_add(skb->truesize, &sk->sk_wmem_alloc);
2047 }
2048 
skb_set_owner_r(struct sk_buff * skb,struct sock * sk)2049 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2050 {
2051 	skb_orphan(skb);
2052 	skb->sk = sk;
2053 	skb->destructor = sock_rfree;
2054 	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2055 	sk_mem_charge(sk, skb->truesize);
2056 }
2057 
2058 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2059 		    unsigned long expires);
2060 
2061 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2062 
2063 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2064 
2065 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2066 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2067 
2068 /*
2069  *	Recover an error report and clear atomically
2070  */
2071 
sock_error(struct sock * sk)2072 static inline int sock_error(struct sock *sk)
2073 {
2074 	int err;
2075 	if (likely(!sk->sk_err))
2076 		return 0;
2077 	err = xchg(&sk->sk_err, 0);
2078 	return -err;
2079 }
2080 
sock_wspace(struct sock * sk)2081 static inline unsigned long sock_wspace(struct sock *sk)
2082 {
2083 	int amt = 0;
2084 
2085 	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2086 		amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
2087 		if (amt < 0)
2088 			amt = 0;
2089 	}
2090 	return amt;
2091 }
2092 
sk_wake_async(struct sock * sk,int how,int band)2093 static inline void sk_wake_async(struct sock *sk, int how, int band)
2094 {
2095 	if (sock_flag(sk, SOCK_FASYNC))
2096 		sock_wake_async(sk->sk_socket, how, band);
2097 }
2098 
2099 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2100  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2101  * Note: for send buffers, TCP works better if we can build two skbs at
2102  * minimum.
2103  */
2104 #define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2105 
2106 #define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
2107 #define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
2108 
sk_stream_moderate_sndbuf(struct sock * sk)2109 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2110 {
2111 	if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
2112 		sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2113 		sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
2114 	}
2115 }
2116 
2117 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
2118 
2119 /**
2120  * sk_page_frag - return an appropriate page_frag
2121  * @sk: socket
2122  *
2123  * If socket allocation mode allows current thread to sleep, it means its
2124  * safe to use the per task page_frag instead of the per socket one.
2125  */
sk_page_frag(struct sock * sk)2126 static inline struct page_frag *sk_page_frag(struct sock *sk)
2127 {
2128 	if (sk->sk_allocation & __GFP_WAIT)
2129 		return &current->task_frag;
2130 
2131 	return &sk->sk_frag;
2132 }
2133 
2134 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2135 
2136 /*
2137  *	Default write policy as shown to user space via poll/select/SIGIO
2138  */
sock_writeable(const struct sock * sk)2139 static inline bool sock_writeable(const struct sock *sk)
2140 {
2141 	return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
2142 }
2143 
gfp_any(void)2144 static inline gfp_t gfp_any(void)
2145 {
2146 	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2147 }
2148 
sock_rcvtimeo(const struct sock * sk,bool noblock)2149 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2150 {
2151 	return noblock ? 0 : sk->sk_rcvtimeo;
2152 }
2153 
sock_sndtimeo(const struct sock * sk,bool noblock)2154 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2155 {
2156 	return noblock ? 0 : sk->sk_sndtimeo;
2157 }
2158 
sock_rcvlowat(const struct sock * sk,int waitall,int len)2159 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2160 {
2161 	return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
2162 }
2163 
2164 /* Alas, with timeout socket operations are not restartable.
2165  * Compare this to poll().
2166  */
sock_intr_errno(long timeo)2167 static inline int sock_intr_errno(long timeo)
2168 {
2169 	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2170 }
2171 
2172 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2173 			   struct sk_buff *skb);
2174 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2175 			     struct sk_buff *skb);
2176 
2177 static inline void
sock_recv_timestamp(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)2178 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2179 {
2180 	ktime_t kt = skb->tstamp;
2181 	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2182 
2183 	/*
2184 	 * generate control messages if
2185 	 * - receive time stamping in software requested
2186 	 * - software time stamp available and wanted
2187 	 * - hardware time stamps available and wanted
2188 	 */
2189 	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2190 	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2191 	    (kt.tv64 && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2192 	    (hwtstamps->hwtstamp.tv64 &&
2193 	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2194 		__sock_recv_timestamp(msg, sk, skb);
2195 	else
2196 		sk->sk_stamp = kt;
2197 
2198 	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2199 		__sock_recv_wifi_status(msg, sk, skb);
2200 }
2201 
2202 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2203 			      struct sk_buff *skb);
2204 
sock_recv_ts_and_drops(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)2205 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2206 					  struct sk_buff *skb)
2207 {
2208 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL)			| \
2209 			   (1UL << SOCK_RCVTSTAMP))
2210 #define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
2211 			   SOF_TIMESTAMPING_RAW_HARDWARE)
2212 
2213 	if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2214 		__sock_recv_ts_and_drops(msg, sk, skb);
2215 	else
2216 		sk->sk_stamp = skb->tstamp;
2217 }
2218 
2219 void __sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags);
2220 
2221 /**
2222  * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2223  * @sk:		socket sending this packet
2224  * @tx_flags:	completed with instructions for time stamping
2225  *
2226  * Note : callers should take care of initial *tx_flags value (usually 0)
2227  */
sock_tx_timestamp(const struct sock * sk,__u8 * tx_flags)2228 static inline void sock_tx_timestamp(const struct sock *sk, __u8 *tx_flags)
2229 {
2230 	if (unlikely(sk->sk_tsflags))
2231 		__sock_tx_timestamp(sk, tx_flags);
2232 	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2233 		*tx_flags |= SKBTX_WIFI_STATUS;
2234 }
2235 
2236 /**
2237  * sk_eat_skb - Release a skb if it is no longer needed
2238  * @sk: socket to eat this skb from
2239  * @skb: socket buffer to eat
2240  *
2241  * This routine must be called with interrupts disabled or with the socket
2242  * locked so that the sk_buff queue operation is ok.
2243 */
sk_eat_skb(struct sock * sk,struct sk_buff * skb)2244 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2245 {
2246 	__skb_unlink(skb, &sk->sk_receive_queue);
2247 	__kfree_skb(skb);
2248 }
2249 
2250 static inline
sock_net(const struct sock * sk)2251 struct net *sock_net(const struct sock *sk)
2252 {
2253 	return read_pnet(&sk->sk_net);
2254 }
2255 
2256 static inline
sock_net_set(struct sock * sk,struct net * net)2257 void sock_net_set(struct sock *sk, struct net *net)
2258 {
2259 	write_pnet(&sk->sk_net, net);
2260 }
2261 
2262 /*
2263  * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace.
2264  * They should not hold a reference to a namespace in order to allow
2265  * to stop it.
2266  * Sockets after sk_change_net should be released using sk_release_kernel
2267  */
sk_change_net(struct sock * sk,struct net * net)2268 static inline void sk_change_net(struct sock *sk, struct net *net)
2269 {
2270 	struct net *current_net = sock_net(sk);
2271 
2272 	if (!net_eq(current_net, net)) {
2273 		put_net(current_net);
2274 		sock_net_set(sk, hold_net(net));
2275 	}
2276 }
2277 
skb_steal_sock(struct sk_buff * skb)2278 static inline struct sock *skb_steal_sock(struct sk_buff *skb)
2279 {
2280 	if (skb->sk) {
2281 		struct sock *sk = skb->sk;
2282 
2283 		skb->destructor = NULL;
2284 		skb->sk = NULL;
2285 		return sk;
2286 	}
2287 	return NULL;
2288 }
2289 
2290 /* This helper checks if a socket is a full socket,
2291  * ie _not_ a timewait or request socket.
2292  * TODO: Check for TCPF_NEW_SYN_RECV when that starts to exist.
2293  */
sk_fullsock(const struct sock * sk)2294 static inline bool sk_fullsock(const struct sock *sk)
2295 {
2296 	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT);
2297 }
2298 
2299 void sock_enable_timestamp(struct sock *sk, int flag);
2300 int sock_get_timestamp(struct sock *, struct timeval __user *);
2301 int sock_get_timestampns(struct sock *, struct timespec __user *);
2302 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2303 		       int type);
2304 
2305 bool sk_ns_capable(const struct sock *sk,
2306 		   struct user_namespace *user_ns, int cap);
2307 bool sk_capable(const struct sock *sk, int cap);
2308 bool sk_net_capable(const struct sock *sk, int cap);
2309 
2310 /*
2311  *	Enable debug/info messages
2312  */
2313 extern int net_msg_warn;
2314 #define NETDEBUG(fmt, args...) \
2315 	do { if (net_msg_warn) printk(fmt,##args); } while (0)
2316 
2317 #define LIMIT_NETDEBUG(fmt, args...) \
2318 	do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0)
2319 
2320 extern __u32 sysctl_wmem_max;
2321 extern __u32 sysctl_rmem_max;
2322 
2323 extern int sysctl_optmem_max;
2324 
2325 extern __u32 sysctl_wmem_default;
2326 extern __u32 sysctl_rmem_default;
2327 
2328 #endif	/* _SOCK_H */
2329