1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the AF_INET socket handler.
8 *
9 * Version: @(#)sock.h 1.0.4 05/13/93
10 *
11 * Authors: Ross Biro
12 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
13 * Corey Minyard <wf-rch!minyard@relay.EU.net>
14 * Florian La Roche <flla@stud.uni-sb.de>
15 *
16 * Fixes:
17 * Alan Cox : Volatiles in skbuff pointers. See
18 * skbuff comments. May be overdone,
19 * better to prove they can be removed
20 * than the reverse.
21 * Alan Cox : Added a zapped field for tcp to note
22 * a socket is reset and must stay shut up
23 * Alan Cox : New fields for options
24 * Pauline Middelink : identd support
25 * Alan Cox : Eliminate low level recv/recvfrom
26 * David S. Miller : New socket lookup architecture.
27 * Steve Whitehouse: Default routines for sock_ops
28 * Arnaldo C. Melo : removed net_pinfo, tp_pinfo and made
29 * protinfo be just a void pointer, as the
30 * protocol specific parts were moved to
31 * respective headers and ipv4/v6, etc now
32 * use private slabcaches for its socks
33 * Pedro Hortas : New flags field for socket options
34 */
35 #ifndef _SOCK_H
36 #define _SOCK_H
37
38 #include <linux/hardirq.h>
39 #include <linux/kernel.h>
40 #include <linux/list.h>
41 #include <linux/list_nulls.h>
42 #include <linux/timer.h>
43 #include <linux/cache.h>
44 #include <linux/bitops.h>
45 #include <linux/lockdep.h>
46 #include <linux/netdevice.h>
47 #include <linux/skbuff.h> /* struct sk_buff */
48 #include <linux/mm.h>
49 #include <linux/security.h>
50 #include <linux/slab.h>
51 #include <linux/uaccess.h>
52 #include <linux/page_counter.h>
53 #include <linux/memcontrol.h>
54 #include <linux/static_key.h>
55 #include <linux/sched.h>
56 #include <linux/wait.h>
57 #include <linux/cgroup-defs.h>
58 #include <linux/rbtree.h>
59 #include <linux/filter.h>
60 #include <linux/rculist_nulls.h>
61 #include <linux/poll.h>
62 #include <linux/sockptr.h>
63
64 #include <linux/atomic.h>
65 #include <linux/refcount.h>
66 #include <net/dst.h>
67 #include <net/checksum.h>
68 #include <net/tcp_states.h>
69 #include <linux/net_tstamp.h>
70 #include <net/l3mdev.h>
71 #ifdef CONFIG_NEWIP
72 #include <uapi/linux/nip_addr.h>
73 #endif
74
75 /*
76 * This structure really needs to be cleaned up.
77 * Most of it is for TCP, and not used by any of
78 * the other protocols.
79 */
80
81 /* Define this to get the SOCK_DBG debugging facility. */
82 #define SOCK_DEBUGGING
83 #ifdef SOCK_DEBUGGING
84 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
85 printk(KERN_DEBUG msg); } while (0)
86 #else
87 /* Validate arguments and do nothing */
88 static inline __printf(2, 3)
SOCK_DEBUG(const struct sock * sk,const char * msg,...)89 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
90 {
91 }
92 #endif
93
94 /* This is the per-socket lock. The spinlock provides a synchronization
95 * between user contexts and software interrupt processing, whereas the
96 * mini-semaphore synchronizes multiple users amongst themselves.
97 */
98 typedef struct {
99 spinlock_t slock;
100 int owned;
101 wait_queue_head_t wq;
102 /*
103 * We express the mutex-alike socket_lock semantics
104 * to the lock validator by explicitly managing
105 * the slock as a lock variant (in addition to
106 * the slock itself):
107 */
108 #ifdef CONFIG_DEBUG_LOCK_ALLOC
109 struct lockdep_map dep_map;
110 #endif
111 } socket_lock_t;
112
113 struct sock;
114 struct proto;
115 struct net;
116
117 typedef __u32 __bitwise __portpair;
118 typedef __u64 __bitwise __addrpair;
119
120 /**
121 * struct sock_common - minimal network layer representation of sockets
122 * @skc_daddr: Foreign IPv4 addr
123 * @skc_rcv_saddr: Bound local IPv4 addr
124 * @skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
125 * @skc_hash: hash value used with various protocol lookup tables
126 * @skc_u16hashes: two u16 hash values used by UDP lookup tables
127 * @skc_dport: placeholder for inet_dport/tw_dport
128 * @skc_num: placeholder for inet_num/tw_num
129 * @skc_portpair: __u32 union of @skc_dport & @skc_num
130 * @skc_family: network address family
131 * @skc_state: Connection state
132 * @skc_reuse: %SO_REUSEADDR setting
133 * @skc_reuseport: %SO_REUSEPORT setting
134 * @skc_ipv6only: socket is IPV6 only
135 * @skc_net_refcnt: socket is using net ref counting
136 * @skc_bound_dev_if: bound device index if != 0
137 * @skc_bind_node: bind hash linkage for various protocol lookup tables
138 * @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
139 * @skc_prot: protocol handlers inside a network family
140 * @skc_net: reference to the network namespace of this socket
141 * @skc_v6_daddr: IPV6 destination address
142 * @skc_v6_rcv_saddr: IPV6 source address
143 * @skc_cookie: socket's cookie value
144 * @skc_node: main hash linkage for various protocol lookup tables
145 * @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
146 * @skc_tx_queue_mapping: tx queue number for this connection
147 * @skc_rx_queue_mapping: rx queue number for this connection
148 * @skc_flags: place holder for sk_flags
149 * %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
150 * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
151 * @skc_listener: connection request listener socket (aka rsk_listener)
152 * [union with @skc_flags]
153 * @skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
154 * [union with @skc_flags]
155 * @skc_incoming_cpu: record/match cpu processing incoming packets
156 * @skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
157 * [union with @skc_incoming_cpu]
158 * @skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
159 * [union with @skc_incoming_cpu]
160 * @skc_refcnt: reference count
161 *
162 * This is the minimal network layer representation of sockets, the header
163 * for struct sock and struct inet_timewait_sock.
164 */
165 struct sock_common {
166 union {
167 __addrpair skc_addrpair;
168 struct {
169 __be32 skc_daddr;
170 __be32 skc_rcv_saddr;
171 };
172 };
173 union {
174 unsigned int skc_hash;
175 __u16 skc_u16hashes[2];
176 };
177 /* skc_dport && skc_num must be grouped as well */
178 union {
179 __portpair skc_portpair;
180 struct {
181 __be16 skc_dport;
182 __u16 skc_num;
183 };
184 };
185
186 unsigned short skc_family;
187 volatile unsigned char skc_state;
188 unsigned char skc_reuse:4;
189 unsigned char skc_reuseport:1;
190 unsigned char skc_ipv6only:1;
191 unsigned char skc_net_refcnt:1;
192 int skc_bound_dev_if;
193 union {
194 struct hlist_node skc_bind_node;
195 struct hlist_node skc_portaddr_node;
196 };
197 struct proto *skc_prot;
198 possible_net_t skc_net;
199
200 #if IS_ENABLED(CONFIG_IPV6)
201 struct in6_addr skc_v6_daddr;
202 struct in6_addr skc_v6_rcv_saddr;
203 #endif
204
205 #if IS_ENABLED(CONFIG_NEWIP)
206 struct nip_addr nip_daddr; /* NIP */
207 struct nip_addr nip_rcv_saddr; /* NIP */
208 #endif
209
210 atomic64_t skc_cookie;
211
212 /* following fields are padding to force
213 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
214 * assuming IPV6 is enabled. We use this padding differently
215 * for different kind of 'sockets'
216 */
217 union {
218 unsigned long skc_flags;
219 struct sock *skc_listener; /* request_sock */
220 struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
221 };
222 /*
223 * fields between dontcopy_begin/dontcopy_end
224 * are not copied in sock_copy()
225 */
226 /* private: */
227 int skc_dontcopy_begin[0];
228 /* public: */
229 union {
230 struct hlist_node skc_node;
231 struct hlist_nulls_node skc_nulls_node;
232 };
233 unsigned short skc_tx_queue_mapping;
234 #ifdef CONFIG_XPS
235 unsigned short skc_rx_queue_mapping;
236 #endif
237 union {
238 int skc_incoming_cpu;
239 u32 skc_rcv_wnd;
240 u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */
241 };
242
243 refcount_t skc_refcnt;
244 /* private: */
245 int skc_dontcopy_end[0];
246 union {
247 u32 skc_rxhash;
248 u32 skc_window_clamp;
249 u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */
250 };
251 /* public: */
252 };
253
254 struct bpf_local_storage;
255
256 /**
257 * struct sock - network layer representation of sockets
258 * @__sk_common: shared layout with inet_timewait_sock
259 * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
260 * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
261 * @sk_lock: synchronizer
262 * @sk_kern_sock: True if sock is using kernel lock classes
263 * @sk_rcvbuf: size of receive buffer in bytes
264 * @sk_wq: sock wait queue and async head
265 * @sk_rx_dst: receive input route used by early demux
266 * @sk_dst_cache: destination cache
267 * @sk_dst_pending_confirm: need to confirm neighbour
268 * @sk_policy: flow policy
269 * @sk_rx_skb_cache: cache copy of recently accessed RX skb
270 * @sk_receive_queue: incoming packets
271 * @sk_wmem_alloc: transmit queue bytes committed
272 * @sk_tsq_flags: TCP Small Queues flags
273 * @sk_write_queue: Packet sending queue
274 * @sk_omem_alloc: "o" is "option" or "other"
275 * @sk_wmem_queued: persistent queue size
276 * @sk_forward_alloc: space allocated forward
277 * @sk_napi_id: id of the last napi context to receive data for sk
278 * @sk_ll_usec: usecs to busypoll when there is no data
279 * @sk_allocation: allocation mode
280 * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
281 * @sk_pacing_status: Pacing status (requested, handled by sch_fq)
282 * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
283 * @sk_sndbuf: size of send buffer in bytes
284 * @__sk_flags_offset: empty field used to determine location of bitfield
285 * @sk_padding: unused element for alignment
286 * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
287 * @sk_no_check_rx: allow zero checksum in RX packets
288 * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
289 * @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
290 * @sk_route_forced_caps: static, forced route capabilities
291 * (set in tcp_init_sock())
292 * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
293 * @sk_gso_max_size: Maximum GSO segment size to build
294 * @sk_gso_max_segs: Maximum number of GSO segments
295 * @sk_pacing_shift: scaling factor for TCP Small Queues
296 * @sk_lingertime: %SO_LINGER l_linger setting
297 * @sk_backlog: always used with the per-socket spinlock held
298 * @sk_callback_lock: used with the callbacks in the end of this struct
299 * @sk_error_queue: rarely used
300 * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
301 * IPV6_ADDRFORM for instance)
302 * @sk_err: last error
303 * @sk_err_soft: errors that don't cause failure but are the cause of a
304 * persistent failure not just 'timed out'
305 * @sk_drops: raw/udp drops counter
306 * @sk_ack_backlog: current listen backlog
307 * @sk_max_ack_backlog: listen backlog set in listen()
308 * @sk_uid: user id of owner
309 * @sk_priority: %SO_PRIORITY setting
310 * @sk_type: socket type (%SOCK_STREAM, etc)
311 * @sk_protocol: which protocol this socket belongs in this network family
312 * @sk_peer_pid: &struct pid for this socket's peer
313 * @sk_peer_cred: %SO_PEERCRED setting
314 * @sk_rcvlowat: %SO_RCVLOWAT setting
315 * @sk_rcvtimeo: %SO_RCVTIMEO setting
316 * @sk_sndtimeo: %SO_SNDTIMEO setting
317 * @sk_txhash: computed flow hash for use on transmit
318 * @sk_filter: socket filtering instructions
319 * @sk_timer: sock cleanup timer
320 * @sk_stamp: time stamp of last packet received
321 * @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
322 * @sk_tsflags: SO_TIMESTAMPING socket options
323 * @sk_tskey: counter to disambiguate concurrent tstamp requests
324 * @sk_zckey: counter to order MSG_ZEROCOPY notifications
325 * @sk_socket: Identd and reporting IO signals
326 * @sk_user_data: RPC layer private data. Write-protected by @sk_callback_lock.
327 * @sk_frag: cached page frag
328 * @sk_peek_off: current peek_offset value
329 * @sk_send_head: front of stuff to transmit
330 * @tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
331 * @sk_tx_skb_cache: cache copy of recently accessed TX skb
332 * @sk_security: used by security modules
333 * @sk_mark: generic packet mark
334 * @sk_cgrp_data: cgroup data for this cgroup
335 * @sk_memcg: this socket's memory cgroup association
336 * @sk_write_pending: a write to stream socket waits to start
337 * @sk_state_change: callback to indicate change in the state of the sock
338 * @sk_data_ready: callback to indicate there is data to be processed
339 * @sk_write_space: callback to indicate there is bf sending space available
340 * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
341 * @sk_backlog_rcv: callback to process the backlog
342 * @sk_validate_xmit_skb: ptr to an optional validate function
343 * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
344 * @sk_reuseport_cb: reuseport group container
345 * @sk_bpf_storage: ptr to cache and control for bpf_sk_storage
346 * @sk_rcu: used during RCU grace period
347 * @sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
348 * @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
349 * @sk_txtime_report_errors: set report errors mode for SO_TXTIME
350 * @sk_txtime_unused: unused txtime flags
351 */
352 struct sock {
353 /*
354 * Now struct inet_timewait_sock also uses sock_common, so please just
355 * don't add nothing before this first member (__sk_common) --acme
356 */
357 struct sock_common __sk_common;
358 #define sk_node __sk_common.skc_node
359 #define sk_nulls_node __sk_common.skc_nulls_node
360 #define sk_refcnt __sk_common.skc_refcnt
361 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
362 #ifdef CONFIG_XPS
363 #define sk_rx_queue_mapping __sk_common.skc_rx_queue_mapping
364 #endif
365
366 #define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
367 #define sk_dontcopy_end __sk_common.skc_dontcopy_end
368 #define sk_hash __sk_common.skc_hash
369 #define sk_portpair __sk_common.skc_portpair
370 #define sk_num __sk_common.skc_num
371 #define sk_dport __sk_common.skc_dport
372 #define sk_addrpair __sk_common.skc_addrpair
373 #define sk_daddr __sk_common.skc_daddr
374 #define sk_rcv_saddr __sk_common.skc_rcv_saddr
375 #define sk_family __sk_common.skc_family
376 #define sk_state __sk_common.skc_state
377 #define sk_reuse __sk_common.skc_reuse
378 #define sk_reuseport __sk_common.skc_reuseport
379 #define sk_ipv6only __sk_common.skc_ipv6only
380 #define sk_net_refcnt __sk_common.skc_net_refcnt
381 #define sk_bound_dev_if __sk_common.skc_bound_dev_if
382 #define sk_bind_node __sk_common.skc_bind_node
383 #define sk_prot __sk_common.skc_prot
384 #define sk_net __sk_common.skc_net
385 #define sk_v6_daddr __sk_common.skc_v6_daddr
386 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
387 #define sk_cookie __sk_common.skc_cookie
388 #define sk_incoming_cpu __sk_common.skc_incoming_cpu
389 #define sk_flags __sk_common.skc_flags
390 #define sk_rxhash __sk_common.skc_rxhash
391
392 socket_lock_t sk_lock;
393 atomic_t sk_drops;
394 int sk_rcvlowat;
395 struct sk_buff_head sk_error_queue;
396 struct sk_buff *sk_rx_skb_cache;
397 struct sk_buff_head sk_receive_queue;
398 /*
399 * The backlog queue is special, it is always used with
400 * the per-socket spinlock held and requires low latency
401 * access. Therefore we special case it's implementation.
402 * Note : rmem_alloc is in this structure to fill a hole
403 * on 64bit arches, not because its logically part of
404 * backlog.
405 */
406 struct {
407 atomic_t rmem_alloc;
408 int len;
409 struct sk_buff *head;
410 struct sk_buff *tail;
411 } sk_backlog;
412 #define sk_rmem_alloc sk_backlog.rmem_alloc
413
414 int sk_forward_alloc;
415 #ifdef CONFIG_NET_RX_BUSY_POLL
416 unsigned int sk_ll_usec;
417 /* ===== mostly read cache line ===== */
418 unsigned int sk_napi_id;
419 #endif
420 int sk_rcvbuf;
421
422 struct sk_filter __rcu *sk_filter;
423 union {
424 struct socket_wq __rcu *sk_wq;
425 /* private: */
426 struct socket_wq *sk_wq_raw;
427 /* public: */
428 };
429 #ifdef CONFIG_XFRM
430 struct xfrm_policy __rcu *sk_policy[2];
431 #endif
432 struct dst_entry __rcu *sk_rx_dst;
433 struct dst_entry __rcu *sk_dst_cache;
434 atomic_t sk_omem_alloc;
435 int sk_sndbuf;
436
437 /* ===== cache line for TX ===== */
438 int sk_wmem_queued;
439 refcount_t sk_wmem_alloc;
440 unsigned long sk_tsq_flags;
441 union {
442 struct sk_buff *sk_send_head;
443 struct rb_root tcp_rtx_queue;
444 };
445 struct sk_buff *sk_tx_skb_cache;
446 struct sk_buff_head sk_write_queue;
447 __s32 sk_peek_off;
448 int sk_write_pending;
449 __u32 sk_dst_pending_confirm;
450 u32 sk_pacing_status; /* see enum sk_pacing */
451 long sk_sndtimeo;
452 struct timer_list sk_timer;
453 __u32 sk_priority;
454 __u32 sk_mark;
455 unsigned long sk_pacing_rate; /* bytes per second */
456 unsigned long sk_max_pacing_rate;
457 struct page_frag sk_frag;
458 netdev_features_t sk_route_caps;
459 netdev_features_t sk_route_nocaps;
460 netdev_features_t sk_route_forced_caps;
461 int sk_gso_type;
462 unsigned int sk_gso_max_size;
463 gfp_t sk_allocation;
464 __u32 sk_txhash;
465
466 /*
467 * Because of non atomicity rules, all
468 * changes are protected by socket lock.
469 */
470 u8 sk_padding : 1,
471 sk_kern_sock : 1,
472 sk_no_check_tx : 1,
473 sk_no_check_rx : 1,
474 sk_userlocks : 4;
475 u8 sk_pacing_shift;
476 u16 sk_type;
477 u16 sk_protocol;
478 u16 sk_gso_max_segs;
479 unsigned long sk_lingertime;
480 struct proto *sk_prot_creator;
481 rwlock_t sk_callback_lock;
482 int sk_err,
483 sk_err_soft;
484 u32 sk_ack_backlog;
485 u32 sk_max_ack_backlog;
486 kuid_t sk_uid;
487 spinlock_t sk_peer_lock;
488 struct pid *sk_peer_pid;
489 const struct cred *sk_peer_cred;
490
491 long sk_rcvtimeo;
492 ktime_t sk_stamp;
493 #if BITS_PER_LONG==32
494 seqlock_t sk_stamp_seq;
495 #endif
496 u16 sk_tsflags;
497 u8 sk_shutdown;
498 u32 sk_tskey;
499 atomic_t sk_zckey;
500
501 u8 sk_clockid;
502 u8 sk_txtime_deadline_mode : 1,
503 sk_txtime_report_errors : 1,
504 sk_txtime_unused : 6;
505
506 struct socket *sk_socket;
507 void *sk_user_data;
508 #ifdef CONFIG_SECURITY
509 void *sk_security;
510 #endif
511 struct sock_cgroup_data sk_cgrp_data;
512 struct mem_cgroup *sk_memcg;
513 void (*sk_state_change)(struct sock *sk);
514 void (*sk_data_ready)(struct sock *sk);
515 void (*sk_write_space)(struct sock *sk);
516 void (*sk_error_report)(struct sock *sk);
517 int (*sk_backlog_rcv)(struct sock *sk,
518 struct sk_buff *skb);
519 #ifdef CONFIG_SOCK_VALIDATE_XMIT
520 struct sk_buff* (*sk_validate_xmit_skb)(struct sock *sk,
521 struct net_device *dev,
522 struct sk_buff *skb);
523 #endif
524 void (*sk_destruct)(struct sock *sk);
525 struct sock_reuseport __rcu *sk_reuseport_cb;
526 #ifdef CONFIG_BPF_SYSCALL
527 struct bpf_local_storage __rcu *sk_bpf_storage;
528 #endif
529 struct rcu_head sk_rcu;
530 };
531
532 enum sk_pacing {
533 SK_PACING_NONE = 0,
534 SK_PACING_NEEDED = 1,
535 SK_PACING_FQ = 2,
536 };
537
538 /* flag bits in sk_user_data
539 *
540 * - SK_USER_DATA_NOCOPY: Pointer stored in sk_user_data might
541 * not be suitable for copying when cloning the socket. For instance,
542 * it can point to a reference counted object. sk_user_data bottom
543 * bit is set if pointer must not be copied.
544 *
545 * - SK_USER_DATA_BPF: Mark whether sk_user_data field is
546 * managed/owned by a BPF reuseport array. This bit should be set
547 * when sk_user_data's sk is added to the bpf's reuseport_array.
548 *
549 * - SK_USER_DATA_PSOCK: Mark whether pointer stored in
550 * sk_user_data points to psock type. This bit should be set
551 * when sk_user_data is assigned to a psock object.
552 */
553 #define SK_USER_DATA_NOCOPY 1UL
554 #define SK_USER_DATA_BPF 2UL
555 #define SK_USER_DATA_PSOCK 4UL
556 #define SK_USER_DATA_PTRMASK ~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
557 SK_USER_DATA_PSOCK)
558
559 /**
560 * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
561 * @sk: socket
562 */
sk_user_data_is_nocopy(const struct sock * sk)563 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
564 {
565 return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
566 }
567
568 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
569
570 /**
571 * __rcu_dereference_sk_user_data_with_flags - return the pointer
572 * only if argument flags all has been set in sk_user_data. Otherwise
573 * return NULL
574 *
575 * @sk: socket
576 * @flags: flag bits
577 */
578 static inline void *
__rcu_dereference_sk_user_data_with_flags(const struct sock * sk,uintptr_t flags)579 __rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
580 uintptr_t flags)
581 {
582 uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
583
584 WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
585
586 if ((sk_user_data & flags) == flags)
587 return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
588 return NULL;
589 }
590
591 #define rcu_dereference_sk_user_data(sk) \
592 __rcu_dereference_sk_user_data_with_flags(sk, 0)
593 #define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags) \
594 ({ \
595 uintptr_t __tmp1 = (uintptr_t)(ptr), \
596 __tmp2 = (uintptr_t)(flags); \
597 WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK); \
598 WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK); \
599 rcu_assign_pointer(__sk_user_data((sk)), \
600 __tmp1 | __tmp2); \
601 })
602 #define rcu_assign_sk_user_data(sk, ptr) \
603 __rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
604
605 /*
606 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
607 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
608 * on a socket means that the socket will reuse everybody else's port
609 * without looking at the other's sk_reuse value.
610 */
611
612 #define SK_NO_REUSE 0
613 #define SK_CAN_REUSE 1
614 #define SK_FORCE_REUSE 2
615
616 int sk_set_peek_off(struct sock *sk, int val);
617
sk_peek_offset(struct sock * sk,int flags)618 static inline int sk_peek_offset(struct sock *sk, int flags)
619 {
620 if (unlikely(flags & MSG_PEEK)) {
621 return READ_ONCE(sk->sk_peek_off);
622 }
623
624 return 0;
625 }
626
sk_peek_offset_bwd(struct sock * sk,int val)627 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
628 {
629 s32 off = READ_ONCE(sk->sk_peek_off);
630
631 if (unlikely(off >= 0)) {
632 off = max_t(s32, off - val, 0);
633 WRITE_ONCE(sk->sk_peek_off, off);
634 }
635 }
636
sk_peek_offset_fwd(struct sock * sk,int val)637 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
638 {
639 sk_peek_offset_bwd(sk, -val);
640 }
641
642 /*
643 * Hashed lists helper routines
644 */
sk_entry(const struct hlist_node * node)645 static inline struct sock *sk_entry(const struct hlist_node *node)
646 {
647 return hlist_entry(node, struct sock, sk_node);
648 }
649
__sk_head(const struct hlist_head * head)650 static inline struct sock *__sk_head(const struct hlist_head *head)
651 {
652 return hlist_entry(head->first, struct sock, sk_node);
653 }
654
sk_head(const struct hlist_head * head)655 static inline struct sock *sk_head(const struct hlist_head *head)
656 {
657 return hlist_empty(head) ? NULL : __sk_head(head);
658 }
659
__sk_nulls_head(const struct hlist_nulls_head * head)660 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
661 {
662 return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
663 }
664
sk_nulls_head(const struct hlist_nulls_head * head)665 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
666 {
667 return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
668 }
669
sk_next(const struct sock * sk)670 static inline struct sock *sk_next(const struct sock *sk)
671 {
672 return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
673 }
674
sk_nulls_next(const struct sock * sk)675 static inline struct sock *sk_nulls_next(const struct sock *sk)
676 {
677 return (!is_a_nulls(sk->sk_nulls_node.next)) ?
678 hlist_nulls_entry(sk->sk_nulls_node.next,
679 struct sock, sk_nulls_node) :
680 NULL;
681 }
682
sk_unhashed(const struct sock * sk)683 static inline bool sk_unhashed(const struct sock *sk)
684 {
685 return hlist_unhashed(&sk->sk_node);
686 }
687
sk_hashed(const struct sock * sk)688 static inline bool sk_hashed(const struct sock *sk)
689 {
690 return !sk_unhashed(sk);
691 }
692
sk_node_init(struct hlist_node * node)693 static inline void sk_node_init(struct hlist_node *node)
694 {
695 node->pprev = NULL;
696 }
697
sk_nulls_node_init(struct hlist_nulls_node * node)698 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
699 {
700 node->pprev = NULL;
701 }
702
__sk_del_node(struct sock * sk)703 static inline void __sk_del_node(struct sock *sk)
704 {
705 __hlist_del(&sk->sk_node);
706 }
707
708 /* NB: equivalent to hlist_del_init_rcu */
__sk_del_node_init(struct sock * sk)709 static inline bool __sk_del_node_init(struct sock *sk)
710 {
711 if (sk_hashed(sk)) {
712 __sk_del_node(sk);
713 sk_node_init(&sk->sk_node);
714 return true;
715 }
716 return false;
717 }
718
719 /* Grab socket reference count. This operation is valid only
720 when sk is ALREADY grabbed f.e. it is found in hash table
721 or a list and the lookup is made under lock preventing hash table
722 modifications.
723 */
724
sock_hold(struct sock * sk)725 static __always_inline void sock_hold(struct sock *sk)
726 {
727 refcount_inc(&sk->sk_refcnt);
728 }
729
730 /* Ungrab socket in the context, which assumes that socket refcnt
731 cannot hit zero, f.e. it is true in context of any socketcall.
732 */
__sock_put(struct sock * sk)733 static __always_inline void __sock_put(struct sock *sk)
734 {
735 refcount_dec(&sk->sk_refcnt);
736 }
737
sk_del_node_init(struct sock * sk)738 static inline bool sk_del_node_init(struct sock *sk)
739 {
740 bool rc = __sk_del_node_init(sk);
741
742 if (rc) {
743 /* paranoid for a while -acme */
744 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
745 __sock_put(sk);
746 }
747 return rc;
748 }
749 #define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
750
__sk_nulls_del_node_init_rcu(struct sock * sk)751 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
752 {
753 if (sk_hashed(sk)) {
754 hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
755 return true;
756 }
757 return false;
758 }
759
sk_nulls_del_node_init_rcu(struct sock * sk)760 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
761 {
762 bool rc = __sk_nulls_del_node_init_rcu(sk);
763
764 if (rc) {
765 /* paranoid for a while -acme */
766 WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
767 __sock_put(sk);
768 }
769 return rc;
770 }
771
__sk_add_node(struct sock * sk,struct hlist_head * list)772 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
773 {
774 hlist_add_head(&sk->sk_node, list);
775 }
776
sk_add_node(struct sock * sk,struct hlist_head * list)777 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
778 {
779 sock_hold(sk);
780 __sk_add_node(sk, list);
781 }
782
sk_add_node_rcu(struct sock * sk,struct hlist_head * list)783 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
784 {
785 sock_hold(sk);
786 if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
787 sk->sk_family == AF_INET6)
788 hlist_add_tail_rcu(&sk->sk_node, list);
789 else
790 hlist_add_head_rcu(&sk->sk_node, list);
791 }
792
sk_add_node_tail_rcu(struct sock * sk,struct hlist_head * list)793 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
794 {
795 sock_hold(sk);
796 hlist_add_tail_rcu(&sk->sk_node, list);
797 }
798
__sk_nulls_add_node_rcu(struct sock * sk,struct hlist_nulls_head * list)799 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
800 {
801 hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
802 }
803
__sk_nulls_add_node_tail_rcu(struct sock * sk,struct hlist_nulls_head * list)804 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
805 {
806 hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
807 }
808
sk_nulls_add_node_rcu(struct sock * sk,struct hlist_nulls_head * list)809 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
810 {
811 sock_hold(sk);
812 __sk_nulls_add_node_rcu(sk, list);
813 }
814
__sk_del_bind_node(struct sock * sk)815 static inline void __sk_del_bind_node(struct sock *sk)
816 {
817 __hlist_del(&sk->sk_bind_node);
818 }
819
sk_add_bind_node(struct sock * sk,struct hlist_head * list)820 static inline void sk_add_bind_node(struct sock *sk,
821 struct hlist_head *list)
822 {
823 hlist_add_head(&sk->sk_bind_node, list);
824 }
825
826 #define sk_for_each(__sk, list) \
827 hlist_for_each_entry(__sk, list, sk_node)
828 #define sk_for_each_rcu(__sk, list) \
829 hlist_for_each_entry_rcu(__sk, list, sk_node)
830 #define sk_nulls_for_each(__sk, node, list) \
831 hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
832 #define sk_nulls_for_each_rcu(__sk, node, list) \
833 hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
834 #define sk_for_each_from(__sk) \
835 hlist_for_each_entry_from(__sk, sk_node)
836 #define sk_nulls_for_each_from(__sk, node) \
837 if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
838 hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
839 #define sk_for_each_safe(__sk, tmp, list) \
840 hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
841 #define sk_for_each_bound(__sk, list) \
842 hlist_for_each_entry(__sk, list, sk_bind_node)
843
844 /**
845 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
846 * @tpos: the type * to use as a loop cursor.
847 * @pos: the &struct hlist_node to use as a loop cursor.
848 * @head: the head for your list.
849 * @offset: offset of hlist_node within the struct.
850 *
851 */
852 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \
853 for (pos = rcu_dereference(hlist_first_rcu(head)); \
854 pos != NULL && \
855 ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \
856 pos = rcu_dereference(hlist_next_rcu(pos)))
857
sk_user_ns(struct sock * sk)858 static inline struct user_namespace *sk_user_ns(struct sock *sk)
859 {
860 /* Careful only use this in a context where these parameters
861 * can not change and must all be valid, such as recvmsg from
862 * userspace.
863 */
864 return sk->sk_socket->file->f_cred->user_ns;
865 }
866
867 /* Sock flags */
868 enum sock_flags {
869 SOCK_DEAD,
870 SOCK_DONE,
871 SOCK_URGINLINE,
872 SOCK_KEEPOPEN,
873 SOCK_LINGER,
874 SOCK_DESTROY,
875 SOCK_BROADCAST,
876 SOCK_TIMESTAMP,
877 SOCK_ZAPPED,
878 SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
879 SOCK_DBG, /* %SO_DEBUG setting */
880 SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
881 SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
882 SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
883 SOCK_MEMALLOC, /* VM depends on this socket for swapping */
884 SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
885 SOCK_FASYNC, /* fasync() active */
886 SOCK_RXQ_OVFL,
887 SOCK_ZEROCOPY, /* buffers from userspace */
888 SOCK_WIFI_STATUS, /* push wifi status to userspace */
889 SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
890 * Will use last 4 bytes of packet sent from
891 * user-space instead.
892 */
893 SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
894 SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
895 SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
896 SOCK_TXTIME,
897 SOCK_XDP, /* XDP is attached */
898 SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
899 };
900
901 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
902
sock_copy_flags(struct sock * nsk,struct sock * osk)903 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
904 {
905 nsk->sk_flags = osk->sk_flags;
906 }
907
sock_set_flag(struct sock * sk,enum sock_flags flag)908 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
909 {
910 __set_bit(flag, &sk->sk_flags);
911 }
912
sock_reset_flag(struct sock * sk,enum sock_flags flag)913 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
914 {
915 __clear_bit(flag, &sk->sk_flags);
916 }
917
sock_valbool_flag(struct sock * sk,enum sock_flags bit,int valbool)918 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
919 int valbool)
920 {
921 if (valbool)
922 sock_set_flag(sk, bit);
923 else
924 sock_reset_flag(sk, bit);
925 }
926
sock_flag(const struct sock * sk,enum sock_flags flag)927 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
928 {
929 return test_bit(flag, &sk->sk_flags);
930 }
931
932 #ifdef CONFIG_NET
933 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
sk_memalloc_socks(void)934 static inline int sk_memalloc_socks(void)
935 {
936 return static_branch_unlikely(&memalloc_socks_key);
937 }
938
939 void __receive_sock(struct file *file);
940 #else
941
sk_memalloc_socks(void)942 static inline int sk_memalloc_socks(void)
943 {
944 return 0;
945 }
946
__receive_sock(struct file * file)947 static inline void __receive_sock(struct file *file)
948 { }
949 #endif
950
sk_gfp_mask(const struct sock * sk,gfp_t gfp_mask)951 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
952 {
953 return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
954 }
955
sk_acceptq_removed(struct sock * sk)956 static inline void sk_acceptq_removed(struct sock *sk)
957 {
958 WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
959 }
960
sk_acceptq_added(struct sock * sk)961 static inline void sk_acceptq_added(struct sock *sk)
962 {
963 WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
964 }
965
sk_acceptq_is_full(const struct sock * sk)966 static inline bool sk_acceptq_is_full(const struct sock *sk)
967 {
968 return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
969 }
970
971 /*
972 * Compute minimal free write space needed to queue new packets.
973 */
sk_stream_min_wspace(const struct sock * sk)974 static inline int sk_stream_min_wspace(const struct sock *sk)
975 {
976 return READ_ONCE(sk->sk_wmem_queued) >> 1;
977 }
978
sk_stream_wspace(const struct sock * sk)979 static inline int sk_stream_wspace(const struct sock *sk)
980 {
981 return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
982 }
983
sk_wmem_queued_add(struct sock * sk,int val)984 static inline void sk_wmem_queued_add(struct sock *sk, int val)
985 {
986 WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
987 }
988
989 void sk_stream_write_space(struct sock *sk);
990
991 /* OOB backlog add */
__sk_add_backlog(struct sock * sk,struct sk_buff * skb)992 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
993 {
994 /* dont let skb dst not refcounted, we are going to leave rcu lock */
995 skb_dst_force(skb);
996
997 if (!sk->sk_backlog.tail)
998 WRITE_ONCE(sk->sk_backlog.head, skb);
999 else
1000 sk->sk_backlog.tail->next = skb;
1001
1002 WRITE_ONCE(sk->sk_backlog.tail, skb);
1003 skb->next = NULL;
1004 }
1005
1006 /*
1007 * Take into account size of receive queue and backlog queue
1008 * Do not take into account this skb truesize,
1009 * to allow even a single big packet to come.
1010 */
sk_rcvqueues_full(const struct sock * sk,unsigned int limit)1011 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
1012 {
1013 unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
1014
1015 return qsize > limit;
1016 }
1017
1018 /* The per-socket spinlock must be held here. */
sk_add_backlog(struct sock * sk,struct sk_buff * skb,unsigned int limit)1019 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
1020 unsigned int limit)
1021 {
1022 if (sk_rcvqueues_full(sk, limit))
1023 return -ENOBUFS;
1024
1025 /*
1026 * If the skb was allocated from pfmemalloc reserves, only
1027 * allow SOCK_MEMALLOC sockets to use it as this socket is
1028 * helping free memory
1029 */
1030 if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
1031 return -ENOMEM;
1032
1033 __sk_add_backlog(sk, skb);
1034 sk->sk_backlog.len += skb->truesize;
1035 return 0;
1036 }
1037
1038 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
1039
sk_backlog_rcv(struct sock * sk,struct sk_buff * skb)1040 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
1041 {
1042 if (sk_memalloc_socks() && skb_pfmemalloc(skb))
1043 return __sk_backlog_rcv(sk, skb);
1044
1045 return sk->sk_backlog_rcv(sk, skb);
1046 }
1047
sk_incoming_cpu_update(struct sock * sk)1048 static inline void sk_incoming_cpu_update(struct sock *sk)
1049 {
1050 int cpu = raw_smp_processor_id();
1051
1052 if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
1053 WRITE_ONCE(sk->sk_incoming_cpu, cpu);
1054 }
1055
sock_rps_record_flow_hash(__u32 hash)1056 static inline void sock_rps_record_flow_hash(__u32 hash)
1057 {
1058 #ifdef CONFIG_RPS
1059 struct rps_sock_flow_table *sock_flow_table;
1060
1061 rcu_read_lock();
1062 sock_flow_table = rcu_dereference(rps_sock_flow_table);
1063 rps_record_sock_flow(sock_flow_table, hash);
1064 rcu_read_unlock();
1065 #endif
1066 }
1067
sock_rps_record_flow(const struct sock * sk)1068 static inline void sock_rps_record_flow(const struct sock *sk)
1069 {
1070 #ifdef CONFIG_RPS
1071 if (static_branch_unlikely(&rfs_needed)) {
1072 /* Reading sk->sk_rxhash might incur an expensive cache line
1073 * miss.
1074 *
1075 * TCP_ESTABLISHED does cover almost all states where RFS
1076 * might be useful, and is cheaper [1] than testing :
1077 * IPv4: inet_sk(sk)->inet_daddr
1078 * IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
1079 * OR an additional socket flag
1080 * [1] : sk_state and sk_prot are in the same cache line.
1081 */
1082 if (sk->sk_state == TCP_ESTABLISHED)
1083 sock_rps_record_flow_hash(sk->sk_rxhash);
1084 }
1085 #endif
1086 }
1087
sock_rps_save_rxhash(struct sock * sk,const struct sk_buff * skb)1088 static inline void sock_rps_save_rxhash(struct sock *sk,
1089 const struct sk_buff *skb)
1090 {
1091 #ifdef CONFIG_RPS
1092 if (unlikely(sk->sk_rxhash != skb->hash))
1093 sk->sk_rxhash = skb->hash;
1094 #endif
1095 }
1096
sock_rps_reset_rxhash(struct sock * sk)1097 static inline void sock_rps_reset_rxhash(struct sock *sk)
1098 {
1099 #ifdef CONFIG_RPS
1100 sk->sk_rxhash = 0;
1101 #endif
1102 }
1103
1104 #define sk_wait_event(__sk, __timeo, __condition, __wait) \
1105 ({ int __rc; \
1106 release_sock(__sk); \
1107 __rc = __condition; \
1108 if (!__rc) { \
1109 *(__timeo) = wait_woken(__wait, \
1110 TASK_INTERRUPTIBLE, \
1111 *(__timeo)); \
1112 } \
1113 sched_annotate_sleep(); \
1114 lock_sock(__sk); \
1115 __rc = __condition; \
1116 __rc; \
1117 })
1118
1119 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
1120 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
1121 void sk_stream_wait_close(struct sock *sk, long timeo_p);
1122 int sk_stream_error(struct sock *sk, int flags, int err);
1123 void sk_stream_kill_queues(struct sock *sk);
1124 void sk_set_memalloc(struct sock *sk);
1125 void sk_clear_memalloc(struct sock *sk);
1126
1127 void __sk_flush_backlog(struct sock *sk);
1128
sk_flush_backlog(struct sock * sk)1129 static inline bool sk_flush_backlog(struct sock *sk)
1130 {
1131 if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
1132 __sk_flush_backlog(sk);
1133 return true;
1134 }
1135 return false;
1136 }
1137
1138 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
1139
1140 struct request_sock_ops;
1141 struct timewait_sock_ops;
1142 struct inet_hashinfo;
1143 struct raw_hashinfo;
1144 struct smc_hashinfo;
1145 struct module;
1146
1147 /*
1148 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
1149 * un-modified. Special care is taken when initializing object to zero.
1150 */
sk_prot_clear_nulls(struct sock * sk,int size)1151 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1152 {
1153 if (offsetof(struct sock, sk_node.next) != 0)
1154 memset(sk, 0, offsetof(struct sock, sk_node.next));
1155 memset(&sk->sk_node.pprev, 0,
1156 size - offsetof(struct sock, sk_node.pprev));
1157 }
1158
1159 /* Networking protocol blocks we attach to sockets.
1160 * socket layer -> transport layer interface
1161 */
1162 struct proto {
1163 void (*close)(struct sock *sk,
1164 long timeout);
1165 int (*pre_connect)(struct sock *sk,
1166 struct sockaddr *uaddr,
1167 int addr_len);
1168 int (*connect)(struct sock *sk,
1169 struct sockaddr *uaddr,
1170 int addr_len);
1171 int (*disconnect)(struct sock *sk, int flags);
1172
1173 struct sock * (*accept)(struct sock *sk, int flags, int *err,
1174 bool kern);
1175
1176 int (*ioctl)(struct sock *sk, int cmd,
1177 unsigned long arg);
1178 int (*init)(struct sock *sk);
1179 void (*destroy)(struct sock *sk);
1180 void (*shutdown)(struct sock *sk, int how);
1181 int (*setsockopt)(struct sock *sk, int level,
1182 int optname, sockptr_t optval,
1183 unsigned int optlen);
1184 int (*getsockopt)(struct sock *sk, int level,
1185 int optname, char __user *optval,
1186 int __user *option);
1187 void (*keepalive)(struct sock *sk, int valbool);
1188 #ifdef CONFIG_COMPAT
1189 int (*compat_ioctl)(struct sock *sk,
1190 unsigned int cmd, unsigned long arg);
1191 #endif
1192 int (*sendmsg)(struct sock *sk, struct msghdr *msg,
1193 size_t len);
1194 int (*recvmsg)(struct sock *sk, struct msghdr *msg,
1195 size_t len, int noblock, int flags,
1196 int *addr_len);
1197 int (*sendpage)(struct sock *sk, struct page *page,
1198 int offset, size_t size, int flags);
1199 int (*bind)(struct sock *sk,
1200 struct sockaddr *addr, int addr_len);
1201 int (*bind_add)(struct sock *sk,
1202 struct sockaddr *addr, int addr_len);
1203
1204 int (*backlog_rcv) (struct sock *sk,
1205 struct sk_buff *skb);
1206
1207 void (*release_cb)(struct sock *sk);
1208
1209 /* Keeping track of sk's, looking them up, and port selection methods. */
1210 int (*hash)(struct sock *sk);
1211 void (*unhash)(struct sock *sk);
1212 void (*rehash)(struct sock *sk);
1213 int (*get_port)(struct sock *sk, unsigned short snum);
1214
1215 /* Keeping track of sockets in use */
1216 #ifdef CONFIG_PROC_FS
1217 unsigned int inuse_idx;
1218 #endif
1219
1220 bool (*stream_memory_free)(const struct sock *sk, int wake);
1221 bool (*stream_memory_read)(const struct sock *sk);
1222 /* Memory pressure */
1223 void (*enter_memory_pressure)(struct sock *sk);
1224 void (*leave_memory_pressure)(struct sock *sk);
1225 atomic_long_t *memory_allocated; /* Current allocated memory. */
1226 struct percpu_counter *sockets_allocated; /* Current number of sockets. */
1227 /*
1228 * Pressure flag: try to collapse.
1229 * Technical note: it is used by multiple contexts non atomically.
1230 * All the __sk_mem_schedule() is of this nature: accounting
1231 * is strict, actions are advisory and have some latency.
1232 */
1233 unsigned long *memory_pressure;
1234 long *sysctl_mem;
1235
1236 int *sysctl_wmem;
1237 int *sysctl_rmem;
1238 u32 sysctl_wmem_offset;
1239 u32 sysctl_rmem_offset;
1240
1241 int max_header;
1242 bool no_autobind;
1243
1244 struct kmem_cache *slab;
1245 unsigned int obj_size;
1246 slab_flags_t slab_flags;
1247 unsigned int useroffset; /* Usercopy region offset */
1248 unsigned int usersize; /* Usercopy region size */
1249
1250 unsigned int __percpu *orphan_count;
1251
1252 struct request_sock_ops *rsk_prot;
1253 struct timewait_sock_ops *twsk_prot;
1254
1255 union {
1256 struct inet_hashinfo *hashinfo;
1257 struct udp_table *udp_table;
1258 struct raw_hashinfo *raw_hash;
1259 struct smc_hashinfo *smc_hash;
1260 } h;
1261
1262 struct module *owner;
1263
1264 char name[32];
1265
1266 struct list_head node;
1267 #ifdef SOCK_REFCNT_DEBUG
1268 atomic_t socks;
1269 #endif
1270 int (*diag_destroy)(struct sock *sk, int err);
1271 } __randomize_layout;
1272
1273 int proto_register(struct proto *prot, int alloc_slab);
1274 void proto_unregister(struct proto *prot);
1275 int sock_load_diag_module(int family, int protocol);
1276
1277 #ifdef SOCK_REFCNT_DEBUG
sk_refcnt_debug_inc(struct sock * sk)1278 static inline void sk_refcnt_debug_inc(struct sock *sk)
1279 {
1280 atomic_inc(&sk->sk_prot->socks);
1281 }
1282
sk_refcnt_debug_dec(struct sock * sk)1283 static inline void sk_refcnt_debug_dec(struct sock *sk)
1284 {
1285 atomic_dec(&sk->sk_prot->socks);
1286 printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
1287 sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
1288 }
1289
sk_refcnt_debug_release(const struct sock * sk)1290 static inline void sk_refcnt_debug_release(const struct sock *sk)
1291 {
1292 if (refcount_read(&sk->sk_refcnt) != 1)
1293 printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
1294 sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
1295 }
1296 #else /* SOCK_REFCNT_DEBUG */
1297 #define sk_refcnt_debug_inc(sk) do { } while (0)
1298 #define sk_refcnt_debug_dec(sk) do { } while (0)
1299 #define sk_refcnt_debug_release(sk) do { } while (0)
1300 #endif /* SOCK_REFCNT_DEBUG */
1301
__sk_stream_memory_free(const struct sock * sk,int wake)1302 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
1303 {
1304 if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
1305 return false;
1306
1307 return sk->sk_prot->stream_memory_free ?
1308 sk->sk_prot->stream_memory_free(sk, wake) : true;
1309 }
1310
sk_stream_memory_free(const struct sock * sk)1311 static inline bool sk_stream_memory_free(const struct sock *sk)
1312 {
1313 return __sk_stream_memory_free(sk, 0);
1314 }
1315
__sk_stream_is_writeable(const struct sock * sk,int wake)1316 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
1317 {
1318 return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
1319 __sk_stream_memory_free(sk, wake);
1320 }
1321
sk_stream_is_writeable(const struct sock * sk)1322 static inline bool sk_stream_is_writeable(const struct sock *sk)
1323 {
1324 return __sk_stream_is_writeable(sk, 0);
1325 }
1326
sk_under_cgroup_hierarchy(struct sock * sk,struct cgroup * ancestor)1327 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
1328 struct cgroup *ancestor)
1329 {
1330 #ifdef CONFIG_SOCK_CGROUP_DATA
1331 return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
1332 ancestor);
1333 #else
1334 return -ENOTSUPP;
1335 #endif
1336 }
1337
sk_has_memory_pressure(const struct sock * sk)1338 static inline bool sk_has_memory_pressure(const struct sock *sk)
1339 {
1340 return sk->sk_prot->memory_pressure != NULL;
1341 }
1342
sk_under_memory_pressure(const struct sock * sk)1343 static inline bool sk_under_memory_pressure(const struct sock *sk)
1344 {
1345 if (!sk->sk_prot->memory_pressure)
1346 return false;
1347
1348 if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
1349 mem_cgroup_under_socket_pressure(sk->sk_memcg))
1350 return true;
1351
1352 return !!*sk->sk_prot->memory_pressure;
1353 }
1354
1355 static inline long
sk_memory_allocated(const struct sock * sk)1356 sk_memory_allocated(const struct sock *sk)
1357 {
1358 return atomic_long_read(sk->sk_prot->memory_allocated);
1359 }
1360
1361 static inline long
sk_memory_allocated_add(struct sock * sk,int amt)1362 sk_memory_allocated_add(struct sock *sk, int amt)
1363 {
1364 return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
1365 }
1366
1367 static inline void
sk_memory_allocated_sub(struct sock * sk,int amt)1368 sk_memory_allocated_sub(struct sock *sk, int amt)
1369 {
1370 atomic_long_sub(amt, sk->sk_prot->memory_allocated);
1371 }
1372
sk_sockets_allocated_dec(struct sock * sk)1373 static inline void sk_sockets_allocated_dec(struct sock *sk)
1374 {
1375 percpu_counter_dec(sk->sk_prot->sockets_allocated);
1376 }
1377
sk_sockets_allocated_inc(struct sock * sk)1378 static inline void sk_sockets_allocated_inc(struct sock *sk)
1379 {
1380 percpu_counter_inc(sk->sk_prot->sockets_allocated);
1381 }
1382
1383 static inline u64
sk_sockets_allocated_read_positive(struct sock * sk)1384 sk_sockets_allocated_read_positive(struct sock *sk)
1385 {
1386 return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
1387 }
1388
1389 static inline int
proto_sockets_allocated_sum_positive(struct proto * prot)1390 proto_sockets_allocated_sum_positive(struct proto *prot)
1391 {
1392 return percpu_counter_sum_positive(prot->sockets_allocated);
1393 }
1394
1395 static inline long
proto_memory_allocated(struct proto * prot)1396 proto_memory_allocated(struct proto *prot)
1397 {
1398 return atomic_long_read(prot->memory_allocated);
1399 }
1400
1401 static inline bool
proto_memory_pressure(struct proto * prot)1402 proto_memory_pressure(struct proto *prot)
1403 {
1404 if (!prot->memory_pressure)
1405 return false;
1406 return !!*prot->memory_pressure;
1407 }
1408
1409
1410 #ifdef CONFIG_PROC_FS
1411 /* Called with local bh disabled */
1412 void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
1413 int sock_prot_inuse_get(struct net *net, struct proto *proto);
1414 int sock_inuse_get(struct net *net);
1415 #else
sock_prot_inuse_add(struct net * net,struct proto * prot,int inc)1416 static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
1417 int inc)
1418 {
1419 }
1420 #endif
1421
1422
1423 /* With per-bucket locks this operation is not-atomic, so that
1424 * this version is not worse.
1425 */
__sk_prot_rehash(struct sock * sk)1426 static inline int __sk_prot_rehash(struct sock *sk)
1427 {
1428 sk->sk_prot->unhash(sk);
1429 return sk->sk_prot->hash(sk);
1430 }
1431
1432 /* About 10 seconds */
1433 #define SOCK_DESTROY_TIME (10*HZ)
1434
1435 /* Sockets 0-1023 can't be bound to unless you are superuser */
1436 #define PROT_SOCK 1024
1437
1438 #define SHUTDOWN_MASK 3
1439 #define RCV_SHUTDOWN 1
1440 #define SEND_SHUTDOWN 2
1441
1442 #define SOCK_SNDBUF_LOCK 1
1443 #define SOCK_RCVBUF_LOCK 2
1444 #define SOCK_BINDADDR_LOCK 4
1445 #define SOCK_BINDPORT_LOCK 8
1446
1447 struct socket_alloc {
1448 struct socket socket;
1449 struct inode vfs_inode;
1450 };
1451
SOCKET_I(struct inode * inode)1452 static inline struct socket *SOCKET_I(struct inode *inode)
1453 {
1454 return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
1455 }
1456
SOCK_INODE(struct socket * socket)1457 static inline struct inode *SOCK_INODE(struct socket *socket)
1458 {
1459 return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
1460 }
1461
1462 /*
1463 * Functions for memory accounting
1464 */
1465 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
1466 int __sk_mem_schedule(struct sock *sk, int size, int kind);
1467 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
1468 void __sk_mem_reclaim(struct sock *sk, int amount);
1469
1470 /* We used to have PAGE_SIZE here, but systems with 64KB pages
1471 * do not necessarily have 16x time more memory than 4KB ones.
1472 */
1473 #define SK_MEM_QUANTUM 4096
1474 #define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
1475 #define SK_MEM_SEND 0
1476 #define SK_MEM_RECV 1
1477
1478 /* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
sk_prot_mem_limits(const struct sock * sk,int index)1479 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
1480 {
1481 long val = READ_ONCE(sk->sk_prot->sysctl_mem[index]);
1482
1483 #if PAGE_SIZE > SK_MEM_QUANTUM
1484 val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
1485 #elif PAGE_SIZE < SK_MEM_QUANTUM
1486 val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
1487 #endif
1488 return val;
1489 }
1490
sk_mem_pages(int amt)1491 static inline int sk_mem_pages(int amt)
1492 {
1493 return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
1494 }
1495
sk_has_account(struct sock * sk)1496 static inline bool sk_has_account(struct sock *sk)
1497 {
1498 /* return true if protocol supports memory accounting */
1499 return !!sk->sk_prot->memory_allocated;
1500 }
1501
sk_wmem_schedule(struct sock * sk,int size)1502 static inline bool sk_wmem_schedule(struct sock *sk, int size)
1503 {
1504 int delta;
1505
1506 if (!sk_has_account(sk))
1507 return true;
1508 delta = size - sk->sk_forward_alloc;
1509 return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
1510 }
1511
1512 static inline bool
sk_rmem_schedule(struct sock * sk,struct sk_buff * skb,int size)1513 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
1514 {
1515 int delta;
1516
1517 if (!sk_has_account(sk))
1518 return true;
1519 delta = size - sk->sk_forward_alloc;
1520 return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
1521 skb_pfmemalloc(skb);
1522 }
1523
sk_mem_reclaim(struct sock * sk)1524 static inline void sk_mem_reclaim(struct sock *sk)
1525 {
1526 if (!sk_has_account(sk))
1527 return;
1528 if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
1529 __sk_mem_reclaim(sk, sk->sk_forward_alloc);
1530 }
1531
sk_mem_reclaim_partial(struct sock * sk)1532 static inline void sk_mem_reclaim_partial(struct sock *sk)
1533 {
1534 if (!sk_has_account(sk))
1535 return;
1536 if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
1537 __sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
1538 }
1539
sk_mem_charge(struct sock * sk,int size)1540 static inline void sk_mem_charge(struct sock *sk, int size)
1541 {
1542 if (!sk_has_account(sk))
1543 return;
1544 sk->sk_forward_alloc -= size;
1545 }
1546
sk_mem_uncharge(struct sock * sk,int size)1547 static inline void sk_mem_uncharge(struct sock *sk, int size)
1548 {
1549 if (!sk_has_account(sk))
1550 return;
1551 sk->sk_forward_alloc += size;
1552
1553 /* Avoid a possible overflow.
1554 * TCP send queues can make this happen, if sk_mem_reclaim()
1555 * is not called and more than 2 GBytes are released at once.
1556 *
1557 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
1558 * no need to hold that much forward allocation anyway.
1559 */
1560 if (unlikely(sk->sk_forward_alloc >= 1 << 21))
1561 __sk_mem_reclaim(sk, 1 << 20);
1562 }
1563
1564 DECLARE_STATIC_KEY_FALSE(tcp_tx_skb_cache_key);
sk_wmem_free_skb(struct sock * sk,struct sk_buff * skb)1565 static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
1566 {
1567 sk_wmem_queued_add(sk, -skb->truesize);
1568 sk_mem_uncharge(sk, skb->truesize);
1569 if (static_branch_unlikely(&tcp_tx_skb_cache_key) &&
1570 !sk->sk_tx_skb_cache && !skb_cloned(skb)) {
1571 skb_ext_reset(skb);
1572 skb_zcopy_clear(skb, true);
1573 sk->sk_tx_skb_cache = skb;
1574 return;
1575 }
1576 __kfree_skb(skb);
1577 }
1578
sock_release_ownership(struct sock * sk)1579 static inline void sock_release_ownership(struct sock *sk)
1580 {
1581 if (sk->sk_lock.owned) {
1582 sk->sk_lock.owned = 0;
1583
1584 /* The sk_lock has mutex_unlock() semantics: */
1585 mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
1586 }
1587 }
1588
1589 /*
1590 * Macro so as to not evaluate some arguments when
1591 * lockdep is not enabled.
1592 *
1593 * Mark both the sk_lock and the sk_lock.slock as a
1594 * per-address-family lock class.
1595 */
1596 #define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
1597 do { \
1598 sk->sk_lock.owned = 0; \
1599 init_waitqueue_head(&sk->sk_lock.wq); \
1600 spin_lock_init(&(sk)->sk_lock.slock); \
1601 debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
1602 sizeof((sk)->sk_lock)); \
1603 lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
1604 (skey), (sname)); \
1605 lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
1606 } while (0)
1607
1608 #ifdef CONFIG_LOCKDEP
lockdep_sock_is_held(const struct sock * sk)1609 static inline bool lockdep_sock_is_held(const struct sock *sk)
1610 {
1611 return lockdep_is_held(&sk->sk_lock) ||
1612 lockdep_is_held(&sk->sk_lock.slock);
1613 }
1614 #endif
1615
1616 void lock_sock_nested(struct sock *sk, int subclass);
1617
lock_sock(struct sock * sk)1618 static inline void lock_sock(struct sock *sk)
1619 {
1620 lock_sock_nested(sk, 0);
1621 }
1622
1623 void __release_sock(struct sock *sk);
1624 void release_sock(struct sock *sk);
1625
1626 /* BH context may only use the following locking interface. */
1627 #define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
1628 #define bh_lock_sock_nested(__sk) \
1629 spin_lock_nested(&((__sk)->sk_lock.slock), \
1630 SINGLE_DEPTH_NESTING)
1631 #define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
1632
1633 bool lock_sock_fast(struct sock *sk);
1634 /**
1635 * unlock_sock_fast - complement of lock_sock_fast
1636 * @sk: socket
1637 * @slow: slow mode
1638 *
1639 * fast unlock socket for user context.
1640 * If slow mode is on, we call regular release_sock()
1641 */
unlock_sock_fast(struct sock * sk,bool slow)1642 static inline void unlock_sock_fast(struct sock *sk, bool slow)
1643 {
1644 if (slow)
1645 release_sock(sk);
1646 else
1647 spin_unlock_bh(&sk->sk_lock.slock);
1648 }
1649
1650 /* Used by processes to "lock" a socket state, so that
1651 * interrupts and bottom half handlers won't change it
1652 * from under us. It essentially blocks any incoming
1653 * packets, so that we won't get any new data or any
1654 * packets that change the state of the socket.
1655 *
1656 * While locked, BH processing will add new packets to
1657 * the backlog queue. This queue is processed by the
1658 * owner of the socket lock right before it is released.
1659 *
1660 * Since ~2.3.5 it is also exclusive sleep lock serializing
1661 * accesses from user process context.
1662 */
1663
sock_owned_by_me(const struct sock * sk)1664 static inline void sock_owned_by_me(const struct sock *sk)
1665 {
1666 #ifdef CONFIG_LOCKDEP
1667 WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
1668 #endif
1669 }
1670
sock_owned_by_user(const struct sock * sk)1671 static inline bool sock_owned_by_user(const struct sock *sk)
1672 {
1673 sock_owned_by_me(sk);
1674 return sk->sk_lock.owned;
1675 }
1676
sock_owned_by_user_nocheck(const struct sock * sk)1677 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
1678 {
1679 return sk->sk_lock.owned;
1680 }
1681
1682 /* no reclassification while locks are held */
sock_allow_reclassification(const struct sock * csk)1683 static inline bool sock_allow_reclassification(const struct sock *csk)
1684 {
1685 struct sock *sk = (struct sock *)csk;
1686
1687 return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
1688 }
1689
1690 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1691 struct proto *prot, int kern);
1692 void sk_free(struct sock *sk);
1693 void sk_destruct(struct sock *sk);
1694 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
1695 void sk_free_unlock_clone(struct sock *sk);
1696
1697 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1698 gfp_t priority);
1699 void __sock_wfree(struct sk_buff *skb);
1700 void sock_wfree(struct sk_buff *skb);
1701 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1702 gfp_t priority);
1703 void skb_orphan_partial(struct sk_buff *skb);
1704 void sock_rfree(struct sk_buff *skb);
1705 void sock_efree(struct sk_buff *skb);
1706 #ifdef CONFIG_INET
1707 void sock_edemux(struct sk_buff *skb);
1708 void sock_pfree(struct sk_buff *skb);
1709 #else
1710 #define sock_edemux sock_efree
1711 #endif
1712
1713 int sock_setsockopt(struct socket *sock, int level, int op,
1714 sockptr_t optval, unsigned int optlen);
1715
1716 int sock_getsockopt(struct socket *sock, int level, int op,
1717 char __user *optval, int __user *optlen);
1718 int sock_gettstamp(struct socket *sock, void __user *userstamp,
1719 bool timeval, bool time32);
1720 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1721 int noblock, int *errcode);
1722 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1723 unsigned long data_len, int noblock,
1724 int *errcode, int max_page_order);
1725 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
1726 void sock_kfree_s(struct sock *sk, void *mem, int size);
1727 void sock_kzfree_s(struct sock *sk, void *mem, int size);
1728 void sk_send_sigurg(struct sock *sk);
1729
1730 struct sockcm_cookie {
1731 u64 transmit_time;
1732 u32 mark;
1733 u16 tsflags;
1734 };
1735
sockcm_init(struct sockcm_cookie * sockc,const struct sock * sk)1736 static inline void sockcm_init(struct sockcm_cookie *sockc,
1737 const struct sock *sk)
1738 {
1739 *sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
1740 }
1741
1742 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
1743 struct sockcm_cookie *sockc);
1744 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1745 struct sockcm_cookie *sockc);
1746
1747 /*
1748 * Functions to fill in entries in struct proto_ops when a protocol
1749 * does not implement a particular function.
1750 */
1751 int sock_no_bind(struct socket *, struct sockaddr *, int);
1752 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
1753 int sock_no_socketpair(struct socket *, struct socket *);
1754 int sock_no_accept(struct socket *, struct socket *, int, bool);
1755 int sock_no_getname(struct socket *, struct sockaddr *, int);
1756 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
1757 int sock_no_listen(struct socket *, int);
1758 int sock_no_shutdown(struct socket *, int);
1759 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
1760 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
1761 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
1762 int sock_no_mmap(struct file *file, struct socket *sock,
1763 struct vm_area_struct *vma);
1764 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
1765 size_t size, int flags);
1766 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
1767 int offset, size_t size, int flags);
1768
1769 /*
1770 * Functions to fill in entries in struct proto_ops when a protocol
1771 * uses the inet style.
1772 */
1773 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1774 char __user *optval, int __user *optlen);
1775 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1776 int flags);
1777 int sock_common_setsockopt(struct socket *sock, int level, int optname,
1778 sockptr_t optval, unsigned int optlen);
1779
1780 void sk_common_release(struct sock *sk);
1781
1782 /*
1783 * Default socket callbacks and setup code
1784 */
1785
1786 /* Initialise core socket variables using an explicit uid. */
1787 void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid);
1788
1789 /* Initialise core socket variables.
1790 * Assumes struct socket *sock is embedded in a struct socket_alloc.
1791 */
1792 void sock_init_data(struct socket *sock, struct sock *sk);
1793
1794 /*
1795 * Socket reference counting postulates.
1796 *
1797 * * Each user of socket SHOULD hold a reference count.
1798 * * Each access point to socket (an hash table bucket, reference from a list,
1799 * running timer, skb in flight MUST hold a reference count.
1800 * * When reference count hits 0, it means it will never increase back.
1801 * * When reference count hits 0, it means that no references from
1802 * outside exist to this socket and current process on current CPU
1803 * is last user and may/should destroy this socket.
1804 * * sk_free is called from any context: process, BH, IRQ. When
1805 * it is called, socket has no references from outside -> sk_free
1806 * may release descendant resources allocated by the socket, but
1807 * to the time when it is called, socket is NOT referenced by any
1808 * hash tables, lists etc.
1809 * * Packets, delivered from outside (from network or from another process)
1810 * and enqueued on receive/error queues SHOULD NOT grab reference count,
1811 * when they sit in queue. Otherwise, packets will leak to hole, when
1812 * socket is looked up by one cpu and unhasing is made by another CPU.
1813 * It is true for udp/raw, netlink (leak to receive and error queues), tcp
1814 * (leak to backlog). Packet socket does all the processing inside
1815 * BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
1816 * use separate SMP lock, so that they are prone too.
1817 */
1818
1819 /* Ungrab socket and destroy it, if it was the last reference. */
sock_put(struct sock * sk)1820 static inline void sock_put(struct sock *sk)
1821 {
1822 if (refcount_dec_and_test(&sk->sk_refcnt))
1823 sk_free(sk);
1824 }
1825 /* Generic version of sock_put(), dealing with all sockets
1826 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
1827 */
1828 void sock_gen_put(struct sock *sk);
1829
1830 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
1831 unsigned int trim_cap, bool refcounted);
sk_receive_skb(struct sock * sk,struct sk_buff * skb,const int nested)1832 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
1833 const int nested)
1834 {
1835 return __sk_receive_skb(sk, skb, nested, 1, true);
1836 }
1837
sk_tx_queue_set(struct sock * sk,int tx_queue)1838 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
1839 {
1840 /* sk_tx_queue_mapping accept only upto a 16-bit value */
1841 if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
1842 return;
1843 sk->sk_tx_queue_mapping = tx_queue;
1844 }
1845
1846 #define NO_QUEUE_MAPPING USHRT_MAX
1847
sk_tx_queue_clear(struct sock * sk)1848 static inline void sk_tx_queue_clear(struct sock *sk)
1849 {
1850 sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
1851 }
1852
sk_tx_queue_get(const struct sock * sk)1853 static inline int sk_tx_queue_get(const struct sock *sk)
1854 {
1855 if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
1856 return sk->sk_tx_queue_mapping;
1857
1858 return -1;
1859 }
1860
sk_rx_queue_set(struct sock * sk,const struct sk_buff * skb)1861 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
1862 {
1863 #ifdef CONFIG_XPS
1864 if (skb_rx_queue_recorded(skb)) {
1865 u16 rx_queue = skb_get_rx_queue(skb);
1866
1867 if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
1868 return;
1869
1870 sk->sk_rx_queue_mapping = rx_queue;
1871 }
1872 #endif
1873 }
1874
sk_rx_queue_clear(struct sock * sk)1875 static inline void sk_rx_queue_clear(struct sock *sk)
1876 {
1877 #ifdef CONFIG_XPS
1878 sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
1879 #endif
1880 }
1881
1882 #ifdef CONFIG_XPS
sk_rx_queue_get(const struct sock * sk)1883 static inline int sk_rx_queue_get(const struct sock *sk)
1884 {
1885 if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
1886 return sk->sk_rx_queue_mapping;
1887
1888 return -1;
1889 }
1890 #endif
1891
sk_set_socket(struct sock * sk,struct socket * sock)1892 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
1893 {
1894 sk->sk_socket = sock;
1895 }
1896
sk_sleep(struct sock * sk)1897 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
1898 {
1899 BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
1900 return &rcu_dereference_raw(sk->sk_wq)->wait;
1901 }
1902 /* Detach socket from process context.
1903 * Announce socket dead, detach it from wait queue and inode.
1904 * Note that parent inode held reference count on this struct sock,
1905 * we do not release it in this function, because protocol
1906 * probably wants some additional cleanups or even continuing
1907 * to work with this socket (TCP).
1908 */
sock_orphan(struct sock * sk)1909 static inline void sock_orphan(struct sock *sk)
1910 {
1911 write_lock_bh(&sk->sk_callback_lock);
1912 sock_set_flag(sk, SOCK_DEAD);
1913 sk_set_socket(sk, NULL);
1914 sk->sk_wq = NULL;
1915 write_unlock_bh(&sk->sk_callback_lock);
1916 }
1917
sock_graft(struct sock * sk,struct socket * parent)1918 static inline void sock_graft(struct sock *sk, struct socket *parent)
1919 {
1920 WARN_ON(parent->sk);
1921 write_lock_bh(&sk->sk_callback_lock);
1922 rcu_assign_pointer(sk->sk_wq, &parent->wq);
1923 parent->sk = sk;
1924 sk_set_socket(sk, parent);
1925 sk->sk_uid = SOCK_INODE(parent)->i_uid;
1926 security_sock_graft(sk, parent);
1927 write_unlock_bh(&sk->sk_callback_lock);
1928 }
1929
1930 kuid_t sock_i_uid(struct sock *sk);
1931 unsigned long sock_i_ino(struct sock *sk);
1932
sock_net_uid(const struct net * net,const struct sock * sk)1933 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
1934 {
1935 return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
1936 }
1937
net_tx_rndhash(void)1938 static inline u32 net_tx_rndhash(void)
1939 {
1940 u32 v = prandom_u32();
1941
1942 return v ?: 1;
1943 }
1944
sk_set_txhash(struct sock * sk)1945 static inline void sk_set_txhash(struct sock *sk)
1946 {
1947 /* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
1948 WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
1949 }
1950
sk_rethink_txhash(struct sock * sk)1951 static inline bool sk_rethink_txhash(struct sock *sk)
1952 {
1953 if (sk->sk_txhash) {
1954 sk_set_txhash(sk);
1955 return true;
1956 }
1957 return false;
1958 }
1959
1960 static inline struct dst_entry *
__sk_dst_get(struct sock * sk)1961 __sk_dst_get(struct sock *sk)
1962 {
1963 return rcu_dereference_check(sk->sk_dst_cache,
1964 lockdep_sock_is_held(sk));
1965 }
1966
1967 static inline struct dst_entry *
sk_dst_get(struct sock * sk)1968 sk_dst_get(struct sock *sk)
1969 {
1970 struct dst_entry *dst;
1971
1972 rcu_read_lock();
1973 dst = rcu_dereference(sk->sk_dst_cache);
1974 if (dst && !atomic_inc_not_zero(&dst->__refcnt))
1975 dst = NULL;
1976 rcu_read_unlock();
1977 return dst;
1978 }
1979
__dst_negative_advice(struct sock * sk)1980 static inline void __dst_negative_advice(struct sock *sk)
1981 {
1982 struct dst_entry *ndst, *dst = __sk_dst_get(sk);
1983
1984 if (dst && dst->ops->negative_advice) {
1985 ndst = dst->ops->negative_advice(dst);
1986
1987 if (ndst != dst) {
1988 rcu_assign_pointer(sk->sk_dst_cache, ndst);
1989 sk_tx_queue_clear(sk);
1990 sk->sk_dst_pending_confirm = 0;
1991 }
1992 }
1993 }
1994
dst_negative_advice(struct sock * sk)1995 static inline void dst_negative_advice(struct sock *sk)
1996 {
1997 sk_rethink_txhash(sk);
1998 __dst_negative_advice(sk);
1999 }
2000
2001 static inline void
__sk_dst_set(struct sock * sk,struct dst_entry * dst)2002 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
2003 {
2004 struct dst_entry *old_dst;
2005
2006 sk_tx_queue_clear(sk);
2007 sk->sk_dst_pending_confirm = 0;
2008 old_dst = rcu_dereference_protected(sk->sk_dst_cache,
2009 lockdep_sock_is_held(sk));
2010 rcu_assign_pointer(sk->sk_dst_cache, dst);
2011 dst_release(old_dst);
2012 }
2013
2014 static inline void
sk_dst_set(struct sock * sk,struct dst_entry * dst)2015 sk_dst_set(struct sock *sk, struct dst_entry *dst)
2016 {
2017 struct dst_entry *old_dst;
2018
2019 sk_tx_queue_clear(sk);
2020 sk->sk_dst_pending_confirm = 0;
2021 old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
2022 dst_release(old_dst);
2023 }
2024
2025 static inline void
__sk_dst_reset(struct sock * sk)2026 __sk_dst_reset(struct sock *sk)
2027 {
2028 __sk_dst_set(sk, NULL);
2029 }
2030
2031 static inline void
sk_dst_reset(struct sock * sk)2032 sk_dst_reset(struct sock *sk)
2033 {
2034 sk_dst_set(sk, NULL);
2035 }
2036
2037 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
2038
2039 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
2040
sk_dst_confirm(struct sock * sk)2041 static inline void sk_dst_confirm(struct sock *sk)
2042 {
2043 if (!READ_ONCE(sk->sk_dst_pending_confirm))
2044 WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
2045 }
2046
sock_confirm_neigh(struct sk_buff * skb,struct neighbour * n)2047 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
2048 {
2049 if (skb_get_dst_pending_confirm(skb)) {
2050 struct sock *sk = skb->sk;
2051 unsigned long now = jiffies;
2052
2053 /* avoid dirtying neighbour */
2054 if (READ_ONCE(n->confirmed) != now)
2055 WRITE_ONCE(n->confirmed, now);
2056 if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
2057 WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
2058 }
2059 }
2060
2061 bool sk_mc_loop(struct sock *sk);
2062
sk_can_gso(const struct sock * sk)2063 static inline bool sk_can_gso(const struct sock *sk)
2064 {
2065 return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
2066 }
2067
2068 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
2069
sk_nocaps_add(struct sock * sk,netdev_features_t flags)2070 static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
2071 {
2072 sk->sk_route_nocaps |= flags;
2073 sk->sk_route_caps &= ~flags;
2074 }
2075
skb_do_copy_data_nocache(struct sock * sk,struct sk_buff * skb,struct iov_iter * from,char * to,int copy,int offset)2076 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
2077 struct iov_iter *from, char *to,
2078 int copy, int offset)
2079 {
2080 if (skb->ip_summed == CHECKSUM_NONE) {
2081 __wsum csum = 0;
2082 if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
2083 return -EFAULT;
2084 skb->csum = csum_block_add(skb->csum, csum, offset);
2085 } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
2086 if (!copy_from_iter_full_nocache(to, copy, from))
2087 return -EFAULT;
2088 } else if (!copy_from_iter_full(to, copy, from))
2089 return -EFAULT;
2090
2091 return 0;
2092 }
2093
skb_add_data_nocache(struct sock * sk,struct sk_buff * skb,struct iov_iter * from,int copy)2094 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
2095 struct iov_iter *from, int copy)
2096 {
2097 int err, offset = skb->len;
2098
2099 err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
2100 copy, offset);
2101 if (err)
2102 __skb_trim(skb, offset);
2103
2104 return err;
2105 }
2106
skb_copy_to_page_nocache(struct sock * sk,struct iov_iter * from,struct sk_buff * skb,struct page * page,int off,int copy)2107 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
2108 struct sk_buff *skb,
2109 struct page *page,
2110 int off, int copy)
2111 {
2112 int err;
2113
2114 err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
2115 copy, skb->len);
2116 if (err)
2117 return err;
2118
2119 skb->len += copy;
2120 skb->data_len += copy;
2121 skb->truesize += copy;
2122 sk_wmem_queued_add(sk, copy);
2123 sk_mem_charge(sk, copy);
2124 return 0;
2125 }
2126
2127 /**
2128 * sk_wmem_alloc_get - returns write allocations
2129 * @sk: socket
2130 *
2131 * Return: sk_wmem_alloc minus initial offset of one
2132 */
sk_wmem_alloc_get(const struct sock * sk)2133 static inline int sk_wmem_alloc_get(const struct sock *sk)
2134 {
2135 return refcount_read(&sk->sk_wmem_alloc) - 1;
2136 }
2137
2138 /**
2139 * sk_rmem_alloc_get - returns read allocations
2140 * @sk: socket
2141 *
2142 * Return: sk_rmem_alloc
2143 */
sk_rmem_alloc_get(const struct sock * sk)2144 static inline int sk_rmem_alloc_get(const struct sock *sk)
2145 {
2146 return atomic_read(&sk->sk_rmem_alloc);
2147 }
2148
2149 /**
2150 * sk_has_allocations - check if allocations are outstanding
2151 * @sk: socket
2152 *
2153 * Return: true if socket has write or read allocations
2154 */
sk_has_allocations(const struct sock * sk)2155 static inline bool sk_has_allocations(const struct sock *sk)
2156 {
2157 return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
2158 }
2159
2160 /**
2161 * skwq_has_sleeper - check if there are any waiting processes
2162 * @wq: struct socket_wq
2163 *
2164 * Return: true if socket_wq has waiting processes
2165 *
2166 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
2167 * barrier call. They were added due to the race found within the tcp code.
2168 *
2169 * Consider following tcp code paths::
2170 *
2171 * CPU1 CPU2
2172 * sys_select receive packet
2173 * ... ...
2174 * __add_wait_queue update tp->rcv_nxt
2175 * ... ...
2176 * tp->rcv_nxt check sock_def_readable
2177 * ... {
2178 * schedule rcu_read_lock();
2179 * wq = rcu_dereference(sk->sk_wq);
2180 * if (wq && waitqueue_active(&wq->wait))
2181 * wake_up_interruptible(&wq->wait)
2182 * ...
2183 * }
2184 *
2185 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
2186 * in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
2187 * could then endup calling schedule and sleep forever if there are no more
2188 * data on the socket.
2189 *
2190 */
skwq_has_sleeper(struct socket_wq * wq)2191 static inline bool skwq_has_sleeper(struct socket_wq *wq)
2192 {
2193 return wq && wq_has_sleeper(&wq->wait);
2194 }
2195
2196 /**
2197 * sock_poll_wait - place memory barrier behind the poll_wait call.
2198 * @filp: file
2199 * @sock: socket to wait on
2200 * @p: poll_table
2201 *
2202 * See the comments in the wq_has_sleeper function.
2203 */
sock_poll_wait(struct file * filp,struct socket * sock,poll_table * p)2204 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
2205 poll_table *p)
2206 {
2207 if (!poll_does_not_wait(p)) {
2208 poll_wait(filp, &sock->wq.wait, p);
2209 /* We need to be sure we are in sync with the
2210 * socket flags modification.
2211 *
2212 * This memory barrier is paired in the wq_has_sleeper.
2213 */
2214 smp_mb();
2215 }
2216 }
2217
skb_set_hash_from_sk(struct sk_buff * skb,struct sock * sk)2218 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
2219 {
2220 /* This pairs with WRITE_ONCE() in sk_set_txhash() */
2221 u32 txhash = READ_ONCE(sk->sk_txhash);
2222
2223 if (txhash) {
2224 skb->l4_hash = 1;
2225 skb->hash = txhash;
2226 }
2227 }
2228
2229 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
2230
2231 /*
2232 * Queue a received datagram if it will fit. Stream and sequenced
2233 * protocols can't normally use this as they need to fit buffers in
2234 * and play with them.
2235 *
2236 * Inlined as it's very short and called for pretty much every
2237 * packet ever received.
2238 */
skb_set_owner_r(struct sk_buff * skb,struct sock * sk)2239 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
2240 {
2241 skb_orphan(skb);
2242 skb->sk = sk;
2243 skb->destructor = sock_rfree;
2244 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
2245 sk_mem_charge(sk, skb->truesize);
2246 }
2247
skb_set_owner_sk_safe(struct sk_buff * skb,struct sock * sk)2248 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
2249 {
2250 if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
2251 skb_orphan(skb);
2252 skb->destructor = sock_efree;
2253 skb->sk = sk;
2254 return true;
2255 }
2256 return false;
2257 }
2258
2259 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
2260 unsigned long expires);
2261
2262 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
2263
2264 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
2265
2266 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
2267 struct sk_buff *skb, unsigned int flags,
2268 void (*destructor)(struct sock *sk,
2269 struct sk_buff *skb));
2270 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2271 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
2272
2273 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
2274 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
2275
2276 /*
2277 * Recover an error report and clear atomically
2278 */
2279
sock_error(struct sock * sk)2280 static inline int sock_error(struct sock *sk)
2281 {
2282 int err;
2283
2284 /* Avoid an atomic operation for the common case.
2285 * This is racy since another cpu/thread can change sk_err under us.
2286 */
2287 if (likely(data_race(!sk->sk_err)))
2288 return 0;
2289
2290 err = xchg(&sk->sk_err, 0);
2291 return -err;
2292 }
2293
sock_wspace(struct sock * sk)2294 static inline unsigned long sock_wspace(struct sock *sk)
2295 {
2296 int amt = 0;
2297
2298 if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
2299 amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
2300 if (amt < 0)
2301 amt = 0;
2302 }
2303 return amt;
2304 }
2305
2306 /* Note:
2307 * We use sk->sk_wq_raw, from contexts knowing this
2308 * pointer is not NULL and cannot disappear/change.
2309 */
sk_set_bit(int nr,struct sock * sk)2310 static inline void sk_set_bit(int nr, struct sock *sk)
2311 {
2312 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2313 !sock_flag(sk, SOCK_FASYNC))
2314 return;
2315
2316 set_bit(nr, &sk->sk_wq_raw->flags);
2317 }
2318
sk_clear_bit(int nr,struct sock * sk)2319 static inline void sk_clear_bit(int nr, struct sock *sk)
2320 {
2321 if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
2322 !sock_flag(sk, SOCK_FASYNC))
2323 return;
2324
2325 clear_bit(nr, &sk->sk_wq_raw->flags);
2326 }
2327
sk_wake_async(const struct sock * sk,int how,int band)2328 static inline void sk_wake_async(const struct sock *sk, int how, int band)
2329 {
2330 if (sock_flag(sk, SOCK_FASYNC)) {
2331 rcu_read_lock();
2332 sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
2333 rcu_read_unlock();
2334 }
2335 }
2336
2337 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
2338 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
2339 * Note: for send buffers, TCP works better if we can build two skbs at
2340 * minimum.
2341 */
2342 #define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
2343
2344 #define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
2345 #define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
2346
sk_stream_moderate_sndbuf(struct sock * sk)2347 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
2348 {
2349 u32 val;
2350
2351 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
2352 return;
2353
2354 val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
2355
2356 WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
2357 }
2358
2359 struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
2360 bool force_schedule);
2361
2362 /**
2363 * sk_page_frag - return an appropriate page_frag
2364 * @sk: socket
2365 *
2366 * Use the per task page_frag instead of the per socket one for
2367 * optimization when we know that we're in process context and own
2368 * everything that's associated with %current.
2369 *
2370 * Both direct reclaim and page faults can nest inside other
2371 * socket operations and end up recursing into sk_page_frag()
2372 * while it's already in use: explicitly avoid task page_frag
2373 * usage if the caller is potentially doing any of them.
2374 * This assumes that page fault handlers use the GFP_NOFS flags.
2375 *
2376 * Return: a per task page_frag if context allows that,
2377 * otherwise a per socket one.
2378 */
sk_page_frag(struct sock * sk)2379 static inline struct page_frag *sk_page_frag(struct sock *sk)
2380 {
2381 if ((sk->sk_allocation & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC | __GFP_FS)) ==
2382 (__GFP_DIRECT_RECLAIM | __GFP_FS))
2383 return ¤t->task_frag;
2384
2385 return &sk->sk_frag;
2386 }
2387
2388 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
2389
2390 /*
2391 * Default write policy as shown to user space via poll/select/SIGIO
2392 */
sock_writeable(const struct sock * sk)2393 static inline bool sock_writeable(const struct sock *sk)
2394 {
2395 return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
2396 }
2397
gfp_any(void)2398 static inline gfp_t gfp_any(void)
2399 {
2400 return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
2401 }
2402
sock_rcvtimeo(const struct sock * sk,bool noblock)2403 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
2404 {
2405 return noblock ? 0 : sk->sk_rcvtimeo;
2406 }
2407
sock_sndtimeo(const struct sock * sk,bool noblock)2408 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
2409 {
2410 return noblock ? 0 : sk->sk_sndtimeo;
2411 }
2412
sock_rcvlowat(const struct sock * sk,int waitall,int len)2413 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
2414 {
2415 int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
2416
2417 return v ?: 1;
2418 }
2419
2420 /* Alas, with timeout socket operations are not restartable.
2421 * Compare this to poll().
2422 */
sock_intr_errno(long timeo)2423 static inline int sock_intr_errno(long timeo)
2424 {
2425 return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
2426 }
2427
2428 struct sock_skb_cb {
2429 u32 dropcount;
2430 };
2431
2432 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
2433 * using skb->cb[] would keep using it directly and utilize its
2434 * alignement guarantee.
2435 */
2436 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
2437 sizeof(struct sock_skb_cb)))
2438
2439 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
2440 SOCK_SKB_CB_OFFSET))
2441
2442 #define sock_skb_cb_check_size(size) \
2443 BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
2444
2445 static inline void
sock_skb_set_dropcount(const struct sock * sk,struct sk_buff * skb)2446 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
2447 {
2448 SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
2449 atomic_read(&sk->sk_drops) : 0;
2450 }
2451
sk_drops_add(struct sock * sk,const struct sk_buff * skb)2452 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
2453 {
2454 int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
2455
2456 atomic_add(segs, &sk->sk_drops);
2457 }
2458
sock_read_timestamp(struct sock * sk)2459 static inline ktime_t sock_read_timestamp(struct sock *sk)
2460 {
2461 #if BITS_PER_LONG==32
2462 unsigned int seq;
2463 ktime_t kt;
2464
2465 do {
2466 seq = read_seqbegin(&sk->sk_stamp_seq);
2467 kt = sk->sk_stamp;
2468 } while (read_seqretry(&sk->sk_stamp_seq, seq));
2469
2470 return kt;
2471 #else
2472 return READ_ONCE(sk->sk_stamp);
2473 #endif
2474 }
2475
sock_write_timestamp(struct sock * sk,ktime_t kt)2476 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
2477 {
2478 #if BITS_PER_LONG==32
2479 write_seqlock(&sk->sk_stamp_seq);
2480 sk->sk_stamp = kt;
2481 write_sequnlock(&sk->sk_stamp_seq);
2482 #else
2483 WRITE_ONCE(sk->sk_stamp, kt);
2484 #endif
2485 }
2486
2487 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
2488 struct sk_buff *skb);
2489 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
2490 struct sk_buff *skb);
2491
2492 static inline void
sock_recv_timestamp(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)2493 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
2494 {
2495 ktime_t kt = skb->tstamp;
2496 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
2497
2498 /*
2499 * generate control messages if
2500 * - receive time stamping in software requested
2501 * - software time stamp available and wanted
2502 * - hardware time stamps available and wanted
2503 */
2504 if (sock_flag(sk, SOCK_RCVTSTAMP) ||
2505 (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
2506 (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
2507 (hwtstamps->hwtstamp &&
2508 (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
2509 __sock_recv_timestamp(msg, sk, skb);
2510 else
2511 sock_write_timestamp(sk, kt);
2512
2513 if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
2514 __sock_recv_wifi_status(msg, sk, skb);
2515 }
2516
2517 void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2518 struct sk_buff *skb);
2519
2520 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
sock_recv_ts_and_drops(struct msghdr * msg,struct sock * sk,struct sk_buff * skb)2521 static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
2522 struct sk_buff *skb)
2523 {
2524 #define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
2525 (1UL << SOCK_RCVTSTAMP))
2526 #define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \
2527 SOF_TIMESTAMPING_RAW_HARDWARE)
2528
2529 if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
2530 __sock_recv_ts_and_drops(msg, sk, skb);
2531 else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
2532 sock_write_timestamp(sk, skb->tstamp);
2533 else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
2534 sock_write_timestamp(sk, 0);
2535 }
2536
2537 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
2538
2539 /**
2540 * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
2541 * @sk: socket sending this packet
2542 * @tsflags: timestamping flags to use
2543 * @tx_flags: completed with instructions for time stamping
2544 * @tskey: filled in with next sk_tskey (not for TCP, which uses seqno)
2545 *
2546 * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
2547 */
_sock_tx_timestamp(struct sock * sk,__u16 tsflags,__u8 * tx_flags,__u32 * tskey)2548 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2549 __u8 *tx_flags, __u32 *tskey)
2550 {
2551 if (unlikely(tsflags)) {
2552 __sock_tx_timestamp(tsflags, tx_flags);
2553 if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
2554 tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
2555 *tskey = sk->sk_tskey++;
2556 }
2557 if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
2558 *tx_flags |= SKBTX_WIFI_STATUS;
2559 }
2560
sock_tx_timestamp(struct sock * sk,__u16 tsflags,__u8 * tx_flags)2561 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
2562 __u8 *tx_flags)
2563 {
2564 _sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
2565 }
2566
skb_setup_tx_timestamp(struct sk_buff * skb,__u16 tsflags)2567 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
2568 {
2569 _sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
2570 &skb_shinfo(skb)->tskey);
2571 }
2572
2573 DECLARE_STATIC_KEY_FALSE(tcp_rx_skb_cache_key);
2574 /**
2575 * sk_eat_skb - Release a skb if it is no longer needed
2576 * @sk: socket to eat this skb from
2577 * @skb: socket buffer to eat
2578 *
2579 * This routine must be called with interrupts disabled or with the socket
2580 * locked so that the sk_buff queue operation is ok.
2581 */
sk_eat_skb(struct sock * sk,struct sk_buff * skb)2582 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
2583 {
2584 __skb_unlink(skb, &sk->sk_receive_queue);
2585 if (static_branch_unlikely(&tcp_rx_skb_cache_key) &&
2586 !sk->sk_rx_skb_cache) {
2587 sk->sk_rx_skb_cache = skb;
2588 skb_orphan(skb);
2589 return;
2590 }
2591 __kfree_skb(skb);
2592 }
2593
2594 static inline
sock_net(const struct sock * sk)2595 struct net *sock_net(const struct sock *sk)
2596 {
2597 return read_pnet(&sk->sk_net);
2598 }
2599
2600 static inline
sock_net_set(struct sock * sk,struct net * net)2601 void sock_net_set(struct sock *sk, struct net *net)
2602 {
2603 write_pnet(&sk->sk_net, net);
2604 }
2605
2606 static inline bool
skb_sk_is_prefetched(struct sk_buff * skb)2607 skb_sk_is_prefetched(struct sk_buff *skb)
2608 {
2609 #ifdef CONFIG_INET
2610 return skb->destructor == sock_pfree;
2611 #else
2612 return false;
2613 #endif /* CONFIG_INET */
2614 }
2615
2616 /* This helper checks if a socket is a full socket,
2617 * ie _not_ a timewait or request socket.
2618 */
sk_fullsock(const struct sock * sk)2619 static inline bool sk_fullsock(const struct sock *sk)
2620 {
2621 return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
2622 }
2623
2624 static inline bool
sk_is_refcounted(struct sock * sk)2625 sk_is_refcounted(struct sock *sk)
2626 {
2627 /* Only full sockets have sk->sk_flags. */
2628 return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
2629 }
2630
2631 /**
2632 * skb_steal_sock - steal a socket from an sk_buff
2633 * @skb: sk_buff to steal the socket from
2634 * @refcounted: is set to true if the socket is reference-counted
2635 */
2636 static inline struct sock *
skb_steal_sock(struct sk_buff * skb,bool * refcounted)2637 skb_steal_sock(struct sk_buff *skb, bool *refcounted)
2638 {
2639 if (skb->sk) {
2640 struct sock *sk = skb->sk;
2641
2642 *refcounted = true;
2643 if (skb_sk_is_prefetched(skb))
2644 *refcounted = sk_is_refcounted(sk);
2645 skb->destructor = NULL;
2646 skb->sk = NULL;
2647 return sk;
2648 }
2649 *refcounted = false;
2650 return NULL;
2651 }
2652
2653 /* Checks if this SKB belongs to an HW offloaded socket
2654 * and whether any SW fallbacks are required based on dev.
2655 * Check decrypted mark in case skb_orphan() cleared socket.
2656 */
sk_validate_xmit_skb(struct sk_buff * skb,struct net_device * dev)2657 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
2658 struct net_device *dev)
2659 {
2660 #ifdef CONFIG_SOCK_VALIDATE_XMIT
2661 struct sock *sk = skb->sk;
2662
2663 if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
2664 skb = sk->sk_validate_xmit_skb(sk, dev, skb);
2665 #ifdef CONFIG_TLS_DEVICE
2666 } else if (unlikely(skb->decrypted)) {
2667 pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
2668 kfree_skb(skb);
2669 skb = NULL;
2670 #endif
2671 }
2672 #endif
2673
2674 return skb;
2675 }
2676
2677 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
2678 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
2679 */
sk_listener(const struct sock * sk)2680 static inline bool sk_listener(const struct sock *sk)
2681 {
2682 return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
2683 }
2684
2685 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
2686 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
2687 int type);
2688
2689 bool sk_ns_capable(const struct sock *sk,
2690 struct user_namespace *user_ns, int cap);
2691 bool sk_capable(const struct sock *sk, int cap);
2692 bool sk_net_capable(const struct sock *sk, int cap);
2693
2694 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
2695
2696 /* Take into consideration the size of the struct sk_buff overhead in the
2697 * determination of these values, since that is non-constant across
2698 * platforms. This makes socket queueing behavior and performance
2699 * not depend upon such differences.
2700 */
2701 #define _SK_MEM_PACKETS 256
2702 #define _SK_MEM_OVERHEAD SKB_TRUESIZE(256)
2703 #define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2704 #define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
2705
2706 extern __u32 sysctl_wmem_max;
2707 extern __u32 sysctl_rmem_max;
2708
2709 extern int sysctl_tstamp_allow_data;
2710 extern int sysctl_optmem_max;
2711
2712 extern __u32 sysctl_wmem_default;
2713 extern __u32 sysctl_rmem_default;
2714
2715 #define SKB_FRAG_PAGE_ORDER get_order(32768)
2716 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2717
sk_get_wmem0(const struct sock * sk,const struct proto * proto)2718 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
2719 {
2720 /* Does this proto have per netns sysctl_wmem ? */
2721 if (proto->sysctl_wmem_offset)
2722 return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
2723
2724 return READ_ONCE(*proto->sysctl_wmem);
2725 }
2726
sk_get_rmem0(const struct sock * sk,const struct proto * proto)2727 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
2728 {
2729 /* Does this proto have per netns sysctl_rmem ? */
2730 if (proto->sysctl_rmem_offset)
2731 return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
2732
2733 return READ_ONCE(*proto->sysctl_rmem);
2734 }
2735
2736 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
2737 * Some wifi drivers need to tweak it to get more chunks.
2738 * They can use this helper from their ndo_start_xmit()
2739 */
sk_pacing_shift_update(struct sock * sk,int val)2740 static inline void sk_pacing_shift_update(struct sock *sk, int val)
2741 {
2742 if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
2743 return;
2744 WRITE_ONCE(sk->sk_pacing_shift, val);
2745 }
2746
2747 /* if a socket is bound to a device, check that the given device
2748 * index is either the same or that the socket is bound to an L3
2749 * master device and the given device index is also enslaved to
2750 * that L3 master
2751 */
sk_dev_equal_l3scope(struct sock * sk,int dif)2752 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
2753 {
2754 int mdif;
2755
2756 if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
2757 return true;
2758
2759 mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
2760 if (mdif && mdif == sk->sk_bound_dev_if)
2761 return true;
2762
2763 return false;
2764 }
2765
2766 void sock_def_readable(struct sock *sk);
2767
2768 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
2769 void sock_enable_timestamps(struct sock *sk);
2770 void sock_no_linger(struct sock *sk);
2771 void sock_set_keepalive(struct sock *sk);
2772 void sock_set_priority(struct sock *sk, u32 priority);
2773 void sock_set_rcvbuf(struct sock *sk, int val);
2774 void sock_set_mark(struct sock *sk, u32 val);
2775 void sock_set_reuseaddr(struct sock *sk);
2776 void sock_set_reuseport(struct sock *sk);
2777 void sock_set_sndtimeo(struct sock *sk, s64 secs);
2778
2779 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
2780
2781 #endif /* _SOCK_H */
2782