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net: net_cls: move cgroupfs classid handling into core
[deliverable/linux.git] / net / core / sock.c
1 /*
2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
5 *
6 * Generic socket support routines. Memory allocators, socket lock/release
7 * handler for protocols to use and generic option handler.
8 *
9 *
10 * Authors: Ross Biro
11 * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12 * Florian La Roche, <flla@stud.uni-sb.de>
13 * Alan Cox, <A.Cox@swansea.ac.uk>
14 *
15 * Fixes:
16 * Alan Cox : Numerous verify_area() problems
17 * Alan Cox : Connecting on a connecting socket
18 * now returns an error for tcp.
19 * Alan Cox : sock->protocol is set correctly.
20 * and is not sometimes left as 0.
21 * Alan Cox : connect handles icmp errors on a
22 * connect properly. Unfortunately there
23 * is a restart syscall nasty there. I
24 * can't match BSD without hacking the C
25 * library. Ideas urgently sought!
26 * Alan Cox : Disallow bind() to addresses that are
27 * not ours - especially broadcast ones!!
28 * Alan Cox : Socket 1024 _IS_ ok for users. (fencepost)
29 * Alan Cox : sock_wfree/sock_rfree don't destroy sockets,
30 * instead they leave that for the DESTROY timer.
31 * Alan Cox : Clean up error flag in accept
32 * Alan Cox : TCP ack handling is buggy, the DESTROY timer
33 * was buggy. Put a remove_sock() in the handler
34 * for memory when we hit 0. Also altered the timer
35 * code. The ACK stuff can wait and needs major
36 * TCP layer surgery.
37 * Alan Cox : Fixed TCP ack bug, removed remove sock
38 * and fixed timer/inet_bh race.
39 * Alan Cox : Added zapped flag for TCP
40 * Alan Cox : Move kfree_skb into skbuff.c and tidied up surplus code
41 * Alan Cox : for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
42 * Alan Cox : kfree_s calls now are kfree_skbmem so we can track skb resources
43 * Alan Cox : Supports socket option broadcast now as does udp. Packet and raw need fixing.
44 * Alan Cox : Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
45 * Rick Sladkey : Relaxed UDP rules for matching packets.
46 * C.E.Hawkins : IFF_PROMISC/SIOCGHWADDR support
47 * Pauline Middelink : identd support
48 * Alan Cox : Fixed connect() taking signals I think.
49 * Alan Cox : SO_LINGER supported
50 * Alan Cox : Error reporting fixes
51 * Anonymous : inet_create tidied up (sk->reuse setting)
52 * Alan Cox : inet sockets don't set sk->type!
53 * Alan Cox : Split socket option code
54 * Alan Cox : Callbacks
55 * Alan Cox : Nagle flag for Charles & Johannes stuff
56 * Alex : Removed restriction on inet fioctl
57 * Alan Cox : Splitting INET from NET core
58 * Alan Cox : Fixed bogus SO_TYPE handling in getsockopt()
59 * Adam Caldwell : Missing return in SO_DONTROUTE/SO_DEBUG code
60 * Alan Cox : Split IP from generic code
61 * Alan Cox : New kfree_skbmem()
62 * Alan Cox : Make SO_DEBUG superuser only.
63 * Alan Cox : Allow anyone to clear SO_DEBUG
64 * (compatibility fix)
65 * Alan Cox : Added optimistic memory grabbing for AF_UNIX throughput.
66 * Alan Cox : Allocator for a socket is settable.
67 * Alan Cox : SO_ERROR includes soft errors.
68 * Alan Cox : Allow NULL arguments on some SO_ opts
69 * Alan Cox : Generic socket allocation to make hooks
70 * easier (suggested by Craig Metz).
71 * Michael Pall : SO_ERROR returns positive errno again
72 * Steve Whitehouse: Added default destructor to free
73 * protocol private data.
74 * Steve Whitehouse: Added various other default routines
75 * common to several socket families.
76 * Chris Evans : Call suser() check last on F_SETOWN
77 * Jay Schulist : Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
78 * Andi Kleen : Add sock_kmalloc()/sock_kfree_s()
79 * Andi Kleen : Fix write_space callback
80 * Chris Evans : Security fixes - signedness again
81 * Arnaldo C. Melo : cleanups, use skb_queue_purge
82 *
83 * To Fix:
84 *
85 *
86 * This program is free software; you can redistribute it and/or
87 * modify it under the terms of the GNU General Public License
88 * as published by the Free Software Foundation; either version
89 * 2 of the License, or (at your option) any later version.
90 */
91
92 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
93
94 #include <linux/capability.h>
95 #include <linux/errno.h>
96 #include <linux/errqueue.h>
97 #include <linux/types.h>
98 #include <linux/socket.h>
99 #include <linux/in.h>
100 #include <linux/kernel.h>
101 #include <linux/module.h>
102 #include <linux/proc_fs.h>
103 #include <linux/seq_file.h>
104 #include <linux/sched.h>
105 #include <linux/timer.h>
106 #include <linux/string.h>
107 #include <linux/sockios.h>
108 #include <linux/net.h>
109 #include <linux/mm.h>
110 #include <linux/slab.h>
111 #include <linux/interrupt.h>
112 #include <linux/poll.h>
113 #include <linux/tcp.h>
114 #include <linux/init.h>
115 #include <linux/highmem.h>
116 #include <linux/user_namespace.h>
117 #include <linux/static_key.h>
118 #include <linux/memcontrol.h>
119 #include <linux/prefetch.h>
120
121 #include <asm/uaccess.h>
122
123 #include <linux/netdevice.h>
124 #include <net/protocol.h>
125 #include <linux/skbuff.h>
126 #include <net/net_namespace.h>
127 #include <net/request_sock.h>
128 #include <net/sock.h>
129 #include <linux/net_tstamp.h>
130 #include <net/xfrm.h>
131 #include <linux/ipsec.h>
132 #include <net/cls_cgroup.h>
133 #include <net/netprio_cgroup.h>
134
135 #include <linux/filter.h>
136
137 #include <trace/events/sock.h>
138
139 #ifdef CONFIG_INET
140 #include <net/tcp.h>
141 #endif
142
143 #include <net/busy_poll.h>
144
145 static DEFINE_MUTEX(proto_list_mutex);
146 static LIST_HEAD(proto_list);
147
148 #ifdef CONFIG_MEMCG_KMEM
149 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
150 {
151 struct proto *proto;
152 int ret = 0;
153
154 mutex_lock(&proto_list_mutex);
155 list_for_each_entry(proto, &proto_list, node) {
156 if (proto->init_cgroup) {
157 ret = proto->init_cgroup(memcg, ss);
158 if (ret)
159 goto out;
160 }
161 }
162
163 mutex_unlock(&proto_list_mutex);
164 return ret;
165 out:
166 list_for_each_entry_continue_reverse(proto, &proto_list, node)
167 if (proto->destroy_cgroup)
168 proto->destroy_cgroup(memcg);
169 mutex_unlock(&proto_list_mutex);
170 return ret;
171 }
172
173 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
174 {
175 struct proto *proto;
176
177 mutex_lock(&proto_list_mutex);
178 list_for_each_entry_reverse(proto, &proto_list, node)
179 if (proto->destroy_cgroup)
180 proto->destroy_cgroup(memcg);
181 mutex_unlock(&proto_list_mutex);
182 }
183 #endif
184
185 /*
186 * Each address family might have different locking rules, so we have
187 * one slock key per address family:
188 */
189 static struct lock_class_key af_family_keys[AF_MAX];
190 static struct lock_class_key af_family_slock_keys[AF_MAX];
191
192 #if defined(CONFIG_MEMCG_KMEM)
193 struct static_key memcg_socket_limit_enabled;
194 EXPORT_SYMBOL(memcg_socket_limit_enabled);
195 #endif
196
197 /*
198 * Make lock validator output more readable. (we pre-construct these
199 * strings build-time, so that runtime initialization of socket
200 * locks is fast):
201 */
202 static const char *const af_family_key_strings[AF_MAX+1] = {
203 "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX" , "sk_lock-AF_INET" ,
204 "sk_lock-AF_AX25" , "sk_lock-AF_IPX" , "sk_lock-AF_APPLETALK",
205 "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE" , "sk_lock-AF_ATMPVC" ,
206 "sk_lock-AF_X25" , "sk_lock-AF_INET6" , "sk_lock-AF_ROSE" ,
207 "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI" , "sk_lock-AF_SECURITY" ,
208 "sk_lock-AF_KEY" , "sk_lock-AF_NETLINK" , "sk_lock-AF_PACKET" ,
209 "sk_lock-AF_ASH" , "sk_lock-AF_ECONET" , "sk_lock-AF_ATMSVC" ,
210 "sk_lock-AF_RDS" , "sk_lock-AF_SNA" , "sk_lock-AF_IRDA" ,
211 "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE" , "sk_lock-AF_LLC" ,
212 "sk_lock-27" , "sk_lock-28" , "sk_lock-AF_CAN" ,
213 "sk_lock-AF_TIPC" , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV" ,
214 "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN" , "sk_lock-AF_PHONET" ,
215 "sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG" ,
216 "sk_lock-AF_NFC" , "sk_lock-AF_VSOCK" , "sk_lock-AF_MAX"
217 };
218 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
219 "slock-AF_UNSPEC", "slock-AF_UNIX" , "slock-AF_INET" ,
220 "slock-AF_AX25" , "slock-AF_IPX" , "slock-AF_APPLETALK",
221 "slock-AF_NETROM", "slock-AF_BRIDGE" , "slock-AF_ATMPVC" ,
222 "slock-AF_X25" , "slock-AF_INET6" , "slock-AF_ROSE" ,
223 "slock-AF_DECnet", "slock-AF_NETBEUI" , "slock-AF_SECURITY" ,
224 "slock-AF_KEY" , "slock-AF_NETLINK" , "slock-AF_PACKET" ,
225 "slock-AF_ASH" , "slock-AF_ECONET" , "slock-AF_ATMSVC" ,
226 "slock-AF_RDS" , "slock-AF_SNA" , "slock-AF_IRDA" ,
227 "slock-AF_PPPOX" , "slock-AF_WANPIPE" , "slock-AF_LLC" ,
228 "slock-27" , "slock-28" , "slock-AF_CAN" ,
229 "slock-AF_TIPC" , "slock-AF_BLUETOOTH", "slock-AF_IUCV" ,
230 "slock-AF_RXRPC" , "slock-AF_ISDN" , "slock-AF_PHONET" ,
231 "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG" ,
232 "slock-AF_NFC" , "slock-AF_VSOCK" ,"slock-AF_MAX"
233 };
234 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
235 "clock-AF_UNSPEC", "clock-AF_UNIX" , "clock-AF_INET" ,
236 "clock-AF_AX25" , "clock-AF_IPX" , "clock-AF_APPLETALK",
237 "clock-AF_NETROM", "clock-AF_BRIDGE" , "clock-AF_ATMPVC" ,
238 "clock-AF_X25" , "clock-AF_INET6" , "clock-AF_ROSE" ,
239 "clock-AF_DECnet", "clock-AF_NETBEUI" , "clock-AF_SECURITY" ,
240 "clock-AF_KEY" , "clock-AF_NETLINK" , "clock-AF_PACKET" ,
241 "clock-AF_ASH" , "clock-AF_ECONET" , "clock-AF_ATMSVC" ,
242 "clock-AF_RDS" , "clock-AF_SNA" , "clock-AF_IRDA" ,
243 "clock-AF_PPPOX" , "clock-AF_WANPIPE" , "clock-AF_LLC" ,
244 "clock-27" , "clock-28" , "clock-AF_CAN" ,
245 "clock-AF_TIPC" , "clock-AF_BLUETOOTH", "clock-AF_IUCV" ,
246 "clock-AF_RXRPC" , "clock-AF_ISDN" , "clock-AF_PHONET" ,
247 "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG" ,
248 "clock-AF_NFC" , "clock-AF_VSOCK" , "clock-AF_MAX"
249 };
250
251 /*
252 * sk_callback_lock locking rules are per-address-family,
253 * so split the lock classes by using a per-AF key:
254 */
255 static struct lock_class_key af_callback_keys[AF_MAX];
256
257 /* Take into consideration the size of the struct sk_buff overhead in the
258 * determination of these values, since that is non-constant across
259 * platforms. This makes socket queueing behavior and performance
260 * not depend upon such differences.
261 */
262 #define _SK_MEM_PACKETS 256
263 #define _SK_MEM_OVERHEAD SKB_TRUESIZE(256)
264 #define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
265 #define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
266
267 /* Run time adjustable parameters. */
268 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
269 EXPORT_SYMBOL(sysctl_wmem_max);
270 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
271 EXPORT_SYMBOL(sysctl_rmem_max);
272 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
273 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
274
275 /* Maximal space eaten by iovec or ancillary data plus some space */
276 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
277 EXPORT_SYMBOL(sysctl_optmem_max);
278
279 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
280 EXPORT_SYMBOL_GPL(memalloc_socks);
281
282 /**
283 * sk_set_memalloc - sets %SOCK_MEMALLOC
284 * @sk: socket to set it on
285 *
286 * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
287 * It's the responsibility of the admin to adjust min_free_kbytes
288 * to meet the requirements
289 */
290 void sk_set_memalloc(struct sock *sk)
291 {
292 sock_set_flag(sk, SOCK_MEMALLOC);
293 sk->sk_allocation |= __GFP_MEMALLOC;
294 static_key_slow_inc(&memalloc_socks);
295 }
296 EXPORT_SYMBOL_GPL(sk_set_memalloc);
297
298 void sk_clear_memalloc(struct sock *sk)
299 {
300 sock_reset_flag(sk, SOCK_MEMALLOC);
301 sk->sk_allocation &= ~__GFP_MEMALLOC;
302 static_key_slow_dec(&memalloc_socks);
303
304 /*
305 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
306 * progress of swapping. However, if SOCK_MEMALLOC is cleared while
307 * it has rmem allocations there is a risk that the user of the
308 * socket cannot make forward progress due to exceeding the rmem
309 * limits. By rights, sk_clear_memalloc() should only be called
310 * on sockets being torn down but warn and reset the accounting if
311 * that assumption breaks.
312 */
313 if (WARN_ON(sk->sk_forward_alloc))
314 sk_mem_reclaim(sk);
315 }
316 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
317
318 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
319 {
320 int ret;
321 unsigned long pflags = current->flags;
322
323 /* these should have been dropped before queueing */
324 BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
325
326 current->flags |= PF_MEMALLOC;
327 ret = sk->sk_backlog_rcv(sk, skb);
328 tsk_restore_flags(current, pflags, PF_MEMALLOC);
329
330 return ret;
331 }
332 EXPORT_SYMBOL(__sk_backlog_rcv);
333
334 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
335 {
336 struct timeval tv;
337
338 if (optlen < sizeof(tv))
339 return -EINVAL;
340 if (copy_from_user(&tv, optval, sizeof(tv)))
341 return -EFAULT;
342 if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
343 return -EDOM;
344
345 if (tv.tv_sec < 0) {
346 static int warned __read_mostly;
347
348 *timeo_p = 0;
349 if (warned < 10 && net_ratelimit()) {
350 warned++;
351 pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
352 __func__, current->comm, task_pid_nr(current));
353 }
354 return 0;
355 }
356 *timeo_p = MAX_SCHEDULE_TIMEOUT;
357 if (tv.tv_sec == 0 && tv.tv_usec == 0)
358 return 0;
359 if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
360 *timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
361 return 0;
362 }
363
364 static void sock_warn_obsolete_bsdism(const char *name)
365 {
366 static int warned;
367 static char warncomm[TASK_COMM_LEN];
368 if (strcmp(warncomm, current->comm) && warned < 5) {
369 strcpy(warncomm, current->comm);
370 pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
371 warncomm, name);
372 warned++;
373 }
374 }
375
376 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
377
378 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
379 {
380 if (sk->sk_flags & flags) {
381 sk->sk_flags &= ~flags;
382 if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
383 net_disable_timestamp();
384 }
385 }
386
387
388 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
389 {
390 int err;
391 int skb_len;
392 unsigned long flags;
393 struct sk_buff_head *list = &sk->sk_receive_queue;
394
395 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
396 atomic_inc(&sk->sk_drops);
397 trace_sock_rcvqueue_full(sk, skb);
398 return -ENOMEM;
399 }
400
401 err = sk_filter(sk, skb);
402 if (err)
403 return err;
404
405 if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
406 atomic_inc(&sk->sk_drops);
407 return -ENOBUFS;
408 }
409
410 skb->dev = NULL;
411 skb_set_owner_r(skb, sk);
412
413 /* Cache the SKB length before we tack it onto the receive
414 * queue. Once it is added it no longer belongs to us and
415 * may be freed by other threads of control pulling packets
416 * from the queue.
417 */
418 skb_len = skb->len;
419
420 /* we escape from rcu protected region, make sure we dont leak
421 * a norefcounted dst
422 */
423 skb_dst_force(skb);
424
425 spin_lock_irqsave(&list->lock, flags);
426 skb->dropcount = atomic_read(&sk->sk_drops);
427 __skb_queue_tail(list, skb);
428 spin_unlock_irqrestore(&list->lock, flags);
429
430 if (!sock_flag(sk, SOCK_DEAD))
431 sk->sk_data_ready(sk, skb_len);
432 return 0;
433 }
434 EXPORT_SYMBOL(sock_queue_rcv_skb);
435
436 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
437 {
438 int rc = NET_RX_SUCCESS;
439
440 if (sk_filter(sk, skb))
441 goto discard_and_relse;
442
443 skb->dev = NULL;
444
445 if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) {
446 atomic_inc(&sk->sk_drops);
447 goto discard_and_relse;
448 }
449 if (nested)
450 bh_lock_sock_nested(sk);
451 else
452 bh_lock_sock(sk);
453 if (!sock_owned_by_user(sk)) {
454 /*
455 * trylock + unlock semantics:
456 */
457 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
458
459 rc = sk_backlog_rcv(sk, skb);
460
461 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
462 } else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
463 bh_unlock_sock(sk);
464 atomic_inc(&sk->sk_drops);
465 goto discard_and_relse;
466 }
467
468 bh_unlock_sock(sk);
469 out:
470 sock_put(sk);
471 return rc;
472 discard_and_relse:
473 kfree_skb(skb);
474 goto out;
475 }
476 EXPORT_SYMBOL(sk_receive_skb);
477
478 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
479 {
480 struct dst_entry *dst = __sk_dst_get(sk);
481
482 if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
483 sk_tx_queue_clear(sk);
484 RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
485 dst_release(dst);
486 return NULL;
487 }
488
489 return dst;
490 }
491 EXPORT_SYMBOL(__sk_dst_check);
492
493 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
494 {
495 struct dst_entry *dst = sk_dst_get(sk);
496
497 if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
498 sk_dst_reset(sk);
499 dst_release(dst);
500 return NULL;
501 }
502
503 return dst;
504 }
505 EXPORT_SYMBOL(sk_dst_check);
506
507 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
508 int optlen)
509 {
510 int ret = -ENOPROTOOPT;
511 #ifdef CONFIG_NETDEVICES
512 struct net *net = sock_net(sk);
513 char devname[IFNAMSIZ];
514 int index;
515
516 /* Sorry... */
517 ret = -EPERM;
518 if (!ns_capable(net->user_ns, CAP_NET_RAW))
519 goto out;
520
521 ret = -EINVAL;
522 if (optlen < 0)
523 goto out;
524
525 /* Bind this socket to a particular device like "eth0",
526 * as specified in the passed interface name. If the
527 * name is "" or the option length is zero the socket
528 * is not bound.
529 */
530 if (optlen > IFNAMSIZ - 1)
531 optlen = IFNAMSIZ - 1;
532 memset(devname, 0, sizeof(devname));
533
534 ret = -EFAULT;
535 if (copy_from_user(devname, optval, optlen))
536 goto out;
537
538 index = 0;
539 if (devname[0] != '\0') {
540 struct net_device *dev;
541
542 rcu_read_lock();
543 dev = dev_get_by_name_rcu(net, devname);
544 if (dev)
545 index = dev->ifindex;
546 rcu_read_unlock();
547 ret = -ENODEV;
548 if (!dev)
549 goto out;
550 }
551
552 lock_sock(sk);
553 sk->sk_bound_dev_if = index;
554 sk_dst_reset(sk);
555 release_sock(sk);
556
557 ret = 0;
558
559 out:
560 #endif
561
562 return ret;
563 }
564
565 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
566 int __user *optlen, int len)
567 {
568 int ret = -ENOPROTOOPT;
569 #ifdef CONFIG_NETDEVICES
570 struct net *net = sock_net(sk);
571 char devname[IFNAMSIZ];
572
573 if (sk->sk_bound_dev_if == 0) {
574 len = 0;
575 goto zero;
576 }
577
578 ret = -EINVAL;
579 if (len < IFNAMSIZ)
580 goto out;
581
582 ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
583 if (ret)
584 goto out;
585
586 len = strlen(devname) + 1;
587
588 ret = -EFAULT;
589 if (copy_to_user(optval, devname, len))
590 goto out;
591
592 zero:
593 ret = -EFAULT;
594 if (put_user(len, optlen))
595 goto out;
596
597 ret = 0;
598
599 out:
600 #endif
601
602 return ret;
603 }
604
605 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
606 {
607 if (valbool)
608 sock_set_flag(sk, bit);
609 else
610 sock_reset_flag(sk, bit);
611 }
612
613 /*
614 * This is meant for all protocols to use and covers goings on
615 * at the socket level. Everything here is generic.
616 */
617
618 int sock_setsockopt(struct socket *sock, int level, int optname,
619 char __user *optval, unsigned int optlen)
620 {
621 struct sock *sk = sock->sk;
622 int val;
623 int valbool;
624 struct linger ling;
625 int ret = 0;
626
627 /*
628 * Options without arguments
629 */
630
631 if (optname == SO_BINDTODEVICE)
632 return sock_setbindtodevice(sk, optval, optlen);
633
634 if (optlen < sizeof(int))
635 return -EINVAL;
636
637 if (get_user(val, (int __user *)optval))
638 return -EFAULT;
639
640 valbool = val ? 1 : 0;
641
642 lock_sock(sk);
643
644 switch (optname) {
645 case SO_DEBUG:
646 if (val && !capable(CAP_NET_ADMIN))
647 ret = -EACCES;
648 else
649 sock_valbool_flag(sk, SOCK_DBG, valbool);
650 break;
651 case SO_REUSEADDR:
652 sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
653 break;
654 case SO_REUSEPORT:
655 sk->sk_reuseport = valbool;
656 break;
657 case SO_TYPE:
658 case SO_PROTOCOL:
659 case SO_DOMAIN:
660 case SO_ERROR:
661 ret = -ENOPROTOOPT;
662 break;
663 case SO_DONTROUTE:
664 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
665 break;
666 case SO_BROADCAST:
667 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
668 break;
669 case SO_SNDBUF:
670 /* Don't error on this BSD doesn't and if you think
671 * about it this is right. Otherwise apps have to
672 * play 'guess the biggest size' games. RCVBUF/SNDBUF
673 * are treated in BSD as hints
674 */
675 val = min_t(u32, val, sysctl_wmem_max);
676 set_sndbuf:
677 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
678 sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
679 /* Wake up sending tasks if we upped the value. */
680 sk->sk_write_space(sk);
681 break;
682
683 case SO_SNDBUFFORCE:
684 if (!capable(CAP_NET_ADMIN)) {
685 ret = -EPERM;
686 break;
687 }
688 goto set_sndbuf;
689
690 case SO_RCVBUF:
691 /* Don't error on this BSD doesn't and if you think
692 * about it this is right. Otherwise apps have to
693 * play 'guess the biggest size' games. RCVBUF/SNDBUF
694 * are treated in BSD as hints
695 */
696 val = min_t(u32, val, sysctl_rmem_max);
697 set_rcvbuf:
698 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
699 /*
700 * We double it on the way in to account for
701 * "struct sk_buff" etc. overhead. Applications
702 * assume that the SO_RCVBUF setting they make will
703 * allow that much actual data to be received on that
704 * socket.
705 *
706 * Applications are unaware that "struct sk_buff" and
707 * other overheads allocate from the receive buffer
708 * during socket buffer allocation.
709 *
710 * And after considering the possible alternatives,
711 * returning the value we actually used in getsockopt
712 * is the most desirable behavior.
713 */
714 sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
715 break;
716
717 case SO_RCVBUFFORCE:
718 if (!capable(CAP_NET_ADMIN)) {
719 ret = -EPERM;
720 break;
721 }
722 goto set_rcvbuf;
723
724 case SO_KEEPALIVE:
725 #ifdef CONFIG_INET
726 if (sk->sk_protocol == IPPROTO_TCP &&
727 sk->sk_type == SOCK_STREAM)
728 tcp_set_keepalive(sk, valbool);
729 #endif
730 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
731 break;
732
733 case SO_OOBINLINE:
734 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
735 break;
736
737 case SO_NO_CHECK:
738 sk->sk_no_check = valbool;
739 break;
740
741 case SO_PRIORITY:
742 if ((val >= 0 && val <= 6) ||
743 ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
744 sk->sk_priority = val;
745 else
746 ret = -EPERM;
747 break;
748
749 case SO_LINGER:
750 if (optlen < sizeof(ling)) {
751 ret = -EINVAL; /* 1003.1g */
752 break;
753 }
754 if (copy_from_user(&ling, optval, sizeof(ling))) {
755 ret = -EFAULT;
756 break;
757 }
758 if (!ling.l_onoff)
759 sock_reset_flag(sk, SOCK_LINGER);
760 else {
761 #if (BITS_PER_LONG == 32)
762 if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
763 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
764 else
765 #endif
766 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
767 sock_set_flag(sk, SOCK_LINGER);
768 }
769 break;
770
771 case SO_BSDCOMPAT:
772 sock_warn_obsolete_bsdism("setsockopt");
773 break;
774
775 case SO_PASSCRED:
776 if (valbool)
777 set_bit(SOCK_PASSCRED, &sock->flags);
778 else
779 clear_bit(SOCK_PASSCRED, &sock->flags);
780 break;
781
782 case SO_TIMESTAMP:
783 case SO_TIMESTAMPNS:
784 if (valbool) {
785 if (optname == SO_TIMESTAMP)
786 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
787 else
788 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
789 sock_set_flag(sk, SOCK_RCVTSTAMP);
790 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
791 } else {
792 sock_reset_flag(sk, SOCK_RCVTSTAMP);
793 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
794 }
795 break;
796
797 case SO_TIMESTAMPING:
798 if (val & ~SOF_TIMESTAMPING_MASK) {
799 ret = -EINVAL;
800 break;
801 }
802 sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
803 val & SOF_TIMESTAMPING_TX_HARDWARE);
804 sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
805 val & SOF_TIMESTAMPING_TX_SOFTWARE);
806 sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
807 val & SOF_TIMESTAMPING_RX_HARDWARE);
808 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
809 sock_enable_timestamp(sk,
810 SOCK_TIMESTAMPING_RX_SOFTWARE);
811 else
812 sock_disable_timestamp(sk,
813 (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
814 sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
815 val & SOF_TIMESTAMPING_SOFTWARE);
816 sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
817 val & SOF_TIMESTAMPING_SYS_HARDWARE);
818 sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
819 val & SOF_TIMESTAMPING_RAW_HARDWARE);
820 break;
821
822 case SO_RCVLOWAT:
823 if (val < 0)
824 val = INT_MAX;
825 sk->sk_rcvlowat = val ? : 1;
826 break;
827
828 case SO_RCVTIMEO:
829 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
830 break;
831
832 case SO_SNDTIMEO:
833 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
834 break;
835
836 case SO_ATTACH_FILTER:
837 ret = -EINVAL;
838 if (optlen == sizeof(struct sock_fprog)) {
839 struct sock_fprog fprog;
840
841 ret = -EFAULT;
842 if (copy_from_user(&fprog, optval, sizeof(fprog)))
843 break;
844
845 ret = sk_attach_filter(&fprog, sk);
846 }
847 break;
848
849 case SO_DETACH_FILTER:
850 ret = sk_detach_filter(sk);
851 break;
852
853 case SO_LOCK_FILTER:
854 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
855 ret = -EPERM;
856 else
857 sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
858 break;
859
860 case SO_PASSSEC:
861 if (valbool)
862 set_bit(SOCK_PASSSEC, &sock->flags);
863 else
864 clear_bit(SOCK_PASSSEC, &sock->flags);
865 break;
866 case SO_MARK:
867 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
868 ret = -EPERM;
869 else
870 sk->sk_mark = val;
871 break;
872
873 /* We implement the SO_SNDLOWAT etc to
874 not be settable (1003.1g 5.3) */
875 case SO_RXQ_OVFL:
876 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
877 break;
878
879 case SO_WIFI_STATUS:
880 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
881 break;
882
883 case SO_PEEK_OFF:
884 if (sock->ops->set_peek_off)
885 sock->ops->set_peek_off(sk, val);
886 else
887 ret = -EOPNOTSUPP;
888 break;
889
890 case SO_NOFCS:
891 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
892 break;
893
894 case SO_SELECT_ERR_QUEUE:
895 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
896 break;
897
898 #ifdef CONFIG_NET_RX_BUSY_POLL
899 case SO_BUSY_POLL:
900 /* allow unprivileged users to decrease the value */
901 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
902 ret = -EPERM;
903 else {
904 if (val < 0)
905 ret = -EINVAL;
906 else
907 sk->sk_ll_usec = val;
908 }
909 break;
910 #endif
911
912 case SO_MAX_PACING_RATE:
913 sk->sk_max_pacing_rate = val;
914 sk->sk_pacing_rate = min(sk->sk_pacing_rate,
915 sk->sk_max_pacing_rate);
916 break;
917
918 default:
919 ret = -ENOPROTOOPT;
920 break;
921 }
922 release_sock(sk);
923 return ret;
924 }
925 EXPORT_SYMBOL(sock_setsockopt);
926
927
928 void cred_to_ucred(struct pid *pid, const struct cred *cred,
929 struct ucred *ucred)
930 {
931 ucred->pid = pid_vnr(pid);
932 ucred->uid = ucred->gid = -1;
933 if (cred) {
934 struct user_namespace *current_ns = current_user_ns();
935
936 ucred->uid = from_kuid_munged(current_ns, cred->euid);
937 ucred->gid = from_kgid_munged(current_ns, cred->egid);
938 }
939 }
940 EXPORT_SYMBOL_GPL(cred_to_ucred);
941
942 int sock_getsockopt(struct socket *sock, int level, int optname,
943 char __user *optval, int __user *optlen)
944 {
945 struct sock *sk = sock->sk;
946
947 union {
948 int val;
949 struct linger ling;
950 struct timeval tm;
951 } v;
952
953 int lv = sizeof(int);
954 int len;
955
956 if (get_user(len, optlen))
957 return -EFAULT;
958 if (len < 0)
959 return -EINVAL;
960
961 memset(&v, 0, sizeof(v));
962
963 switch (optname) {
964 case SO_DEBUG:
965 v.val = sock_flag(sk, SOCK_DBG);
966 break;
967
968 case SO_DONTROUTE:
969 v.val = sock_flag(sk, SOCK_LOCALROUTE);
970 break;
971
972 case SO_BROADCAST:
973 v.val = sock_flag(sk, SOCK_BROADCAST);
974 break;
975
976 case SO_SNDBUF:
977 v.val = sk->sk_sndbuf;
978 break;
979
980 case SO_RCVBUF:
981 v.val = sk->sk_rcvbuf;
982 break;
983
984 case SO_REUSEADDR:
985 v.val = sk->sk_reuse;
986 break;
987
988 case SO_REUSEPORT:
989 v.val = sk->sk_reuseport;
990 break;
991
992 case SO_KEEPALIVE:
993 v.val = sock_flag(sk, SOCK_KEEPOPEN);
994 break;
995
996 case SO_TYPE:
997 v.val = sk->sk_type;
998 break;
999
1000 case SO_PROTOCOL:
1001 v.val = sk->sk_protocol;
1002 break;
1003
1004 case SO_DOMAIN:
1005 v.val = sk->sk_family;
1006 break;
1007
1008 case SO_ERROR:
1009 v.val = -sock_error(sk);
1010 if (v.val == 0)
1011 v.val = xchg(&sk->sk_err_soft, 0);
1012 break;
1013
1014 case SO_OOBINLINE:
1015 v.val = sock_flag(sk, SOCK_URGINLINE);
1016 break;
1017
1018 case SO_NO_CHECK:
1019 v.val = sk->sk_no_check;
1020 break;
1021
1022 case SO_PRIORITY:
1023 v.val = sk->sk_priority;
1024 break;
1025
1026 case SO_LINGER:
1027 lv = sizeof(v.ling);
1028 v.ling.l_onoff = sock_flag(sk, SOCK_LINGER);
1029 v.ling.l_linger = sk->sk_lingertime / HZ;
1030 break;
1031
1032 case SO_BSDCOMPAT:
1033 sock_warn_obsolete_bsdism("getsockopt");
1034 break;
1035
1036 case SO_TIMESTAMP:
1037 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1038 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1039 break;
1040
1041 case SO_TIMESTAMPNS:
1042 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1043 break;
1044
1045 case SO_TIMESTAMPING:
1046 v.val = 0;
1047 if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
1048 v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
1049 if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
1050 v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
1051 if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
1052 v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
1053 if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
1054 v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
1055 if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
1056 v.val |= SOF_TIMESTAMPING_SOFTWARE;
1057 if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
1058 v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
1059 if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
1060 v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
1061 break;
1062
1063 case SO_RCVTIMEO:
1064 lv = sizeof(struct timeval);
1065 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1066 v.tm.tv_sec = 0;
1067 v.tm.tv_usec = 0;
1068 } else {
1069 v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1070 v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1071 }
1072 break;
1073
1074 case SO_SNDTIMEO:
1075 lv = sizeof(struct timeval);
1076 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1077 v.tm.tv_sec = 0;
1078 v.tm.tv_usec = 0;
1079 } else {
1080 v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1081 v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1082 }
1083 break;
1084
1085 case SO_RCVLOWAT:
1086 v.val = sk->sk_rcvlowat;
1087 break;
1088
1089 case SO_SNDLOWAT:
1090 v.val = 1;
1091 break;
1092
1093 case SO_PASSCRED:
1094 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1095 break;
1096
1097 case SO_PEERCRED:
1098 {
1099 struct ucred peercred;
1100 if (len > sizeof(peercred))
1101 len = sizeof(peercred);
1102 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1103 if (copy_to_user(optval, &peercred, len))
1104 return -EFAULT;
1105 goto lenout;
1106 }
1107
1108 case SO_PEERNAME:
1109 {
1110 char address[128];
1111
1112 if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1113 return -ENOTCONN;
1114 if (lv < len)
1115 return -EINVAL;
1116 if (copy_to_user(optval, address, len))
1117 return -EFAULT;
1118 goto lenout;
1119 }
1120
1121 /* Dubious BSD thing... Probably nobody even uses it, but
1122 * the UNIX standard wants it for whatever reason... -DaveM
1123 */
1124 case SO_ACCEPTCONN:
1125 v.val = sk->sk_state == TCP_LISTEN;
1126 break;
1127
1128 case SO_PASSSEC:
1129 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1130 break;
1131
1132 case SO_PEERSEC:
1133 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1134
1135 case SO_MARK:
1136 v.val = sk->sk_mark;
1137 break;
1138
1139 case SO_RXQ_OVFL:
1140 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1141 break;
1142
1143 case SO_WIFI_STATUS:
1144 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1145 break;
1146
1147 case SO_PEEK_OFF:
1148 if (!sock->ops->set_peek_off)
1149 return -EOPNOTSUPP;
1150
1151 v.val = sk->sk_peek_off;
1152 break;
1153 case SO_NOFCS:
1154 v.val = sock_flag(sk, SOCK_NOFCS);
1155 break;
1156
1157 case SO_BINDTODEVICE:
1158 return sock_getbindtodevice(sk, optval, optlen, len);
1159
1160 case SO_GET_FILTER:
1161 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1162 if (len < 0)
1163 return len;
1164
1165 goto lenout;
1166
1167 case SO_LOCK_FILTER:
1168 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1169 break;
1170
1171 case SO_SELECT_ERR_QUEUE:
1172 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1173 break;
1174
1175 #ifdef CONFIG_NET_RX_BUSY_POLL
1176 case SO_BUSY_POLL:
1177 v.val = sk->sk_ll_usec;
1178 break;
1179 #endif
1180
1181 case SO_MAX_PACING_RATE:
1182 v.val = sk->sk_max_pacing_rate;
1183 break;
1184
1185 default:
1186 return -ENOPROTOOPT;
1187 }
1188
1189 if (len > lv)
1190 len = lv;
1191 if (copy_to_user(optval, &v, len))
1192 return -EFAULT;
1193 lenout:
1194 if (put_user(len, optlen))
1195 return -EFAULT;
1196 return 0;
1197 }
1198
1199 /*
1200 * Initialize an sk_lock.
1201 *
1202 * (We also register the sk_lock with the lock validator.)
1203 */
1204 static inline void sock_lock_init(struct sock *sk)
1205 {
1206 sock_lock_init_class_and_name(sk,
1207 af_family_slock_key_strings[sk->sk_family],
1208 af_family_slock_keys + sk->sk_family,
1209 af_family_key_strings[sk->sk_family],
1210 af_family_keys + sk->sk_family);
1211 }
1212
1213 /*
1214 * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1215 * even temporarly, because of RCU lookups. sk_node should also be left as is.
1216 * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1217 */
1218 static void sock_copy(struct sock *nsk, const struct sock *osk)
1219 {
1220 #ifdef CONFIG_SECURITY_NETWORK
1221 void *sptr = nsk->sk_security;
1222 #endif
1223 memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1224
1225 memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1226 osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1227
1228 #ifdef CONFIG_SECURITY_NETWORK
1229 nsk->sk_security = sptr;
1230 security_sk_clone(osk, nsk);
1231 #endif
1232 }
1233
1234 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1235 {
1236 unsigned long nulls1, nulls2;
1237
1238 nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1239 nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1240 if (nulls1 > nulls2)
1241 swap(nulls1, nulls2);
1242
1243 if (nulls1 != 0)
1244 memset((char *)sk, 0, nulls1);
1245 memset((char *)sk + nulls1 + sizeof(void *), 0,
1246 nulls2 - nulls1 - sizeof(void *));
1247 memset((char *)sk + nulls2 + sizeof(void *), 0,
1248 size - nulls2 - sizeof(void *));
1249 }
1250 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1251
1252 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1253 int family)
1254 {
1255 struct sock *sk;
1256 struct kmem_cache *slab;
1257
1258 slab = prot->slab;
1259 if (slab != NULL) {
1260 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1261 if (!sk)
1262 return sk;
1263 if (priority & __GFP_ZERO) {
1264 if (prot->clear_sk)
1265 prot->clear_sk(sk, prot->obj_size);
1266 else
1267 sk_prot_clear_nulls(sk, prot->obj_size);
1268 }
1269 } else
1270 sk = kmalloc(prot->obj_size, priority);
1271
1272 if (sk != NULL) {
1273 kmemcheck_annotate_bitfield(sk, flags);
1274
1275 if (security_sk_alloc(sk, family, priority))
1276 goto out_free;
1277
1278 if (!try_module_get(prot->owner))
1279 goto out_free_sec;
1280 sk_tx_queue_clear(sk);
1281 }
1282
1283 return sk;
1284
1285 out_free_sec:
1286 security_sk_free(sk);
1287 out_free:
1288 if (slab != NULL)
1289 kmem_cache_free(slab, sk);
1290 else
1291 kfree(sk);
1292 return NULL;
1293 }
1294
1295 static void sk_prot_free(struct proto *prot, struct sock *sk)
1296 {
1297 struct kmem_cache *slab;
1298 struct module *owner;
1299
1300 owner = prot->owner;
1301 slab = prot->slab;
1302
1303 security_sk_free(sk);
1304 if (slab != NULL)
1305 kmem_cache_free(slab, sk);
1306 else
1307 kfree(sk);
1308 module_put(owner);
1309 }
1310
1311 #if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
1312 void sock_update_netprioidx(struct sock *sk)
1313 {
1314 if (in_interrupt())
1315 return;
1316
1317 sk->sk_cgrp_prioidx = task_netprioidx(current);
1318 }
1319 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1320 #endif
1321
1322 /**
1323 * sk_alloc - All socket objects are allocated here
1324 * @net: the applicable net namespace
1325 * @family: protocol family
1326 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1327 * @prot: struct proto associated with this new sock instance
1328 */
1329 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1330 struct proto *prot)
1331 {
1332 struct sock *sk;
1333
1334 sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1335 if (sk) {
1336 sk->sk_family = family;
1337 /*
1338 * See comment in struct sock definition to understand
1339 * why we need sk_prot_creator -acme
1340 */
1341 sk->sk_prot = sk->sk_prot_creator = prot;
1342 sock_lock_init(sk);
1343 sock_net_set(sk, get_net(net));
1344 atomic_set(&sk->sk_wmem_alloc, 1);
1345
1346 sock_update_classid(sk);
1347 sock_update_netprioidx(sk);
1348 }
1349
1350 return sk;
1351 }
1352 EXPORT_SYMBOL(sk_alloc);
1353
1354 static void __sk_free(struct sock *sk)
1355 {
1356 struct sk_filter *filter;
1357
1358 if (sk->sk_destruct)
1359 sk->sk_destruct(sk);
1360
1361 filter = rcu_dereference_check(sk->sk_filter,
1362 atomic_read(&sk->sk_wmem_alloc) == 0);
1363 if (filter) {
1364 sk_filter_uncharge(sk, filter);
1365 RCU_INIT_POINTER(sk->sk_filter, NULL);
1366 }
1367
1368 sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1369
1370 if (atomic_read(&sk->sk_omem_alloc))
1371 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1372 __func__, atomic_read(&sk->sk_omem_alloc));
1373
1374 if (sk->sk_peer_cred)
1375 put_cred(sk->sk_peer_cred);
1376 put_pid(sk->sk_peer_pid);
1377 put_net(sock_net(sk));
1378 sk_prot_free(sk->sk_prot_creator, sk);
1379 }
1380
1381 void sk_free(struct sock *sk)
1382 {
1383 /*
1384 * We subtract one from sk_wmem_alloc and can know if
1385 * some packets are still in some tx queue.
1386 * If not null, sock_wfree() will call __sk_free(sk) later
1387 */
1388 if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1389 __sk_free(sk);
1390 }
1391 EXPORT_SYMBOL(sk_free);
1392
1393 /*
1394 * Last sock_put should drop reference to sk->sk_net. It has already
1395 * been dropped in sk_change_net. Taking reference to stopping namespace
1396 * is not an option.
1397 * Take reference to a socket to remove it from hash _alive_ and after that
1398 * destroy it in the context of init_net.
1399 */
1400 void sk_release_kernel(struct sock *sk)
1401 {
1402 if (sk == NULL || sk->sk_socket == NULL)
1403 return;
1404
1405 sock_hold(sk);
1406 sock_release(sk->sk_socket);
1407 release_net(sock_net(sk));
1408 sock_net_set(sk, get_net(&init_net));
1409 sock_put(sk);
1410 }
1411 EXPORT_SYMBOL(sk_release_kernel);
1412
1413 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1414 {
1415 if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1416 sock_update_memcg(newsk);
1417 }
1418
1419 /**
1420 * sk_clone_lock - clone a socket, and lock its clone
1421 * @sk: the socket to clone
1422 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1423 *
1424 * Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1425 */
1426 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1427 {
1428 struct sock *newsk;
1429
1430 newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1431 if (newsk != NULL) {
1432 struct sk_filter *filter;
1433
1434 sock_copy(newsk, sk);
1435
1436 /* SANITY */
1437 get_net(sock_net(newsk));
1438 sk_node_init(&newsk->sk_node);
1439 sock_lock_init(newsk);
1440 bh_lock_sock(newsk);
1441 newsk->sk_backlog.head = newsk->sk_backlog.tail = NULL;
1442 newsk->sk_backlog.len = 0;
1443
1444 atomic_set(&newsk->sk_rmem_alloc, 0);
1445 /*
1446 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1447 */
1448 atomic_set(&newsk->sk_wmem_alloc, 1);
1449 atomic_set(&newsk->sk_omem_alloc, 0);
1450 skb_queue_head_init(&newsk->sk_receive_queue);
1451 skb_queue_head_init(&newsk->sk_write_queue);
1452 #ifdef CONFIG_NET_DMA
1453 skb_queue_head_init(&newsk->sk_async_wait_queue);
1454 #endif
1455
1456 spin_lock_init(&newsk->sk_dst_lock);
1457 rwlock_init(&newsk->sk_callback_lock);
1458 lockdep_set_class_and_name(&newsk->sk_callback_lock,
1459 af_callback_keys + newsk->sk_family,
1460 af_family_clock_key_strings[newsk->sk_family]);
1461
1462 newsk->sk_dst_cache = NULL;
1463 newsk->sk_wmem_queued = 0;
1464 newsk->sk_forward_alloc = 0;
1465 newsk->sk_send_head = NULL;
1466 newsk->sk_userlocks = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1467
1468 sock_reset_flag(newsk, SOCK_DONE);
1469 skb_queue_head_init(&newsk->sk_error_queue);
1470
1471 filter = rcu_dereference_protected(newsk->sk_filter, 1);
1472 if (filter != NULL)
1473 sk_filter_charge(newsk, filter);
1474
1475 if (unlikely(xfrm_sk_clone_policy(newsk))) {
1476 /* It is still raw copy of parent, so invalidate
1477 * destructor and make plain sk_free() */
1478 newsk->sk_destruct = NULL;
1479 bh_unlock_sock(newsk);
1480 sk_free(newsk);
1481 newsk = NULL;
1482 goto out;
1483 }
1484
1485 newsk->sk_err = 0;
1486 newsk->sk_priority = 0;
1487 /*
1488 * Before updating sk_refcnt, we must commit prior changes to memory
1489 * (Documentation/RCU/rculist_nulls.txt for details)
1490 */
1491 smp_wmb();
1492 atomic_set(&newsk->sk_refcnt, 2);
1493
1494 /*
1495 * Increment the counter in the same struct proto as the master
1496 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1497 * is the same as sk->sk_prot->socks, as this field was copied
1498 * with memcpy).
1499 *
1500 * This _changes_ the previous behaviour, where
1501 * tcp_create_openreq_child always was incrementing the
1502 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1503 * to be taken into account in all callers. -acme
1504 */
1505 sk_refcnt_debug_inc(newsk);
1506 sk_set_socket(newsk, NULL);
1507 newsk->sk_wq = NULL;
1508
1509 sk_update_clone(sk, newsk);
1510
1511 if (newsk->sk_prot->sockets_allocated)
1512 sk_sockets_allocated_inc(newsk);
1513
1514 if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1515 net_enable_timestamp();
1516 }
1517 out:
1518 return newsk;
1519 }
1520 EXPORT_SYMBOL_GPL(sk_clone_lock);
1521
1522 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1523 {
1524 __sk_dst_set(sk, dst);
1525 sk->sk_route_caps = dst->dev->features;
1526 if (sk->sk_route_caps & NETIF_F_GSO)
1527 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1528 sk->sk_route_caps &= ~sk->sk_route_nocaps;
1529 if (sk_can_gso(sk)) {
1530 if (dst->header_len) {
1531 sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1532 } else {
1533 sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1534 sk->sk_gso_max_size = dst->dev->gso_max_size;
1535 sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1536 }
1537 }
1538 }
1539 EXPORT_SYMBOL_GPL(sk_setup_caps);
1540
1541 /*
1542 * Simple resource managers for sockets.
1543 */
1544
1545
1546 /*
1547 * Write buffer destructor automatically called from kfree_skb.
1548 */
1549 void sock_wfree(struct sk_buff *skb)
1550 {
1551 struct sock *sk = skb->sk;
1552 unsigned int len = skb->truesize;
1553
1554 if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1555 /*
1556 * Keep a reference on sk_wmem_alloc, this will be released
1557 * after sk_write_space() call
1558 */
1559 atomic_sub(len - 1, &sk->sk_wmem_alloc);
1560 sk->sk_write_space(sk);
1561 len = 1;
1562 }
1563 /*
1564 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1565 * could not do because of in-flight packets
1566 */
1567 if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1568 __sk_free(sk);
1569 }
1570 EXPORT_SYMBOL(sock_wfree);
1571
1572 void skb_orphan_partial(struct sk_buff *skb)
1573 {
1574 /* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1575 * so we do not completely orphan skb, but transfert all
1576 * accounted bytes but one, to avoid unexpected reorders.
1577 */
1578 if (skb->destructor == sock_wfree
1579 #ifdef CONFIG_INET
1580 || skb->destructor == tcp_wfree
1581 #endif
1582 ) {
1583 atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1584 skb->truesize = 1;
1585 } else {
1586 skb_orphan(skb);
1587 }
1588 }
1589 EXPORT_SYMBOL(skb_orphan_partial);
1590
1591 /*
1592 * Read buffer destructor automatically called from kfree_skb.
1593 */
1594 void sock_rfree(struct sk_buff *skb)
1595 {
1596 struct sock *sk = skb->sk;
1597 unsigned int len = skb->truesize;
1598
1599 atomic_sub(len, &sk->sk_rmem_alloc);
1600 sk_mem_uncharge(sk, len);
1601 }
1602 EXPORT_SYMBOL(sock_rfree);
1603
1604 void sock_edemux(struct sk_buff *skb)
1605 {
1606 struct sock *sk = skb->sk;
1607
1608 #ifdef CONFIG_INET
1609 if (sk->sk_state == TCP_TIME_WAIT)
1610 inet_twsk_put(inet_twsk(sk));
1611 else
1612 #endif
1613 sock_put(sk);
1614 }
1615 EXPORT_SYMBOL(sock_edemux);
1616
1617 kuid_t sock_i_uid(struct sock *sk)
1618 {
1619 kuid_t uid;
1620
1621 read_lock_bh(&sk->sk_callback_lock);
1622 uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1623 read_unlock_bh(&sk->sk_callback_lock);
1624 return uid;
1625 }
1626 EXPORT_SYMBOL(sock_i_uid);
1627
1628 unsigned long sock_i_ino(struct sock *sk)
1629 {
1630 unsigned long ino;
1631
1632 read_lock_bh(&sk->sk_callback_lock);
1633 ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1634 read_unlock_bh(&sk->sk_callback_lock);
1635 return ino;
1636 }
1637 EXPORT_SYMBOL(sock_i_ino);
1638
1639 /*
1640 * Allocate a skb from the socket's send buffer.
1641 */
1642 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1643 gfp_t priority)
1644 {
1645 if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1646 struct sk_buff *skb = alloc_skb(size, priority);
1647 if (skb) {
1648 skb_set_owner_w(skb, sk);
1649 return skb;
1650 }
1651 }
1652 return NULL;
1653 }
1654 EXPORT_SYMBOL(sock_wmalloc);
1655
1656 /*
1657 * Allocate a skb from the socket's receive buffer.
1658 */
1659 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1660 gfp_t priority)
1661 {
1662 if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1663 struct sk_buff *skb = alloc_skb(size, priority);
1664 if (skb) {
1665 skb_set_owner_r(skb, sk);
1666 return skb;
1667 }
1668 }
1669 return NULL;
1670 }
1671
1672 /*
1673 * Allocate a memory block from the socket's option memory buffer.
1674 */
1675 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1676 {
1677 if ((unsigned int)size <= sysctl_optmem_max &&
1678 atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1679 void *mem;
1680 /* First do the add, to avoid the race if kmalloc
1681 * might sleep.
1682 */
1683 atomic_add(size, &sk->sk_omem_alloc);
1684 mem = kmalloc(size, priority);
1685 if (mem)
1686 return mem;
1687 atomic_sub(size, &sk->sk_omem_alloc);
1688 }
1689 return NULL;
1690 }
1691 EXPORT_SYMBOL(sock_kmalloc);
1692
1693 /*
1694 * Free an option memory block.
1695 */
1696 void sock_kfree_s(struct sock *sk, void *mem, int size)
1697 {
1698 kfree(mem);
1699 atomic_sub(size, &sk->sk_omem_alloc);
1700 }
1701 EXPORT_SYMBOL(sock_kfree_s);
1702
1703 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1704 I think, these locks should be removed for datagram sockets.
1705 */
1706 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1707 {
1708 DEFINE_WAIT(wait);
1709
1710 clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1711 for (;;) {
1712 if (!timeo)
1713 break;
1714 if (signal_pending(current))
1715 break;
1716 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1717 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1718 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1719 break;
1720 if (sk->sk_shutdown & SEND_SHUTDOWN)
1721 break;
1722 if (sk->sk_err)
1723 break;
1724 timeo = schedule_timeout(timeo);
1725 }
1726 finish_wait(sk_sleep(sk), &wait);
1727 return timeo;
1728 }
1729
1730
1731 /*
1732 * Generic send/receive buffer handlers
1733 */
1734
1735 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1736 unsigned long data_len, int noblock,
1737 int *errcode, int max_page_order)
1738 {
1739 struct sk_buff *skb = NULL;
1740 unsigned long chunk;
1741 gfp_t gfp_mask;
1742 long timeo;
1743 int err;
1744 int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1745 struct page *page;
1746 int i;
1747
1748 err = -EMSGSIZE;
1749 if (npages > MAX_SKB_FRAGS)
1750 goto failure;
1751
1752 timeo = sock_sndtimeo(sk, noblock);
1753 while (!skb) {
1754 err = sock_error(sk);
1755 if (err != 0)
1756 goto failure;
1757
1758 err = -EPIPE;
1759 if (sk->sk_shutdown & SEND_SHUTDOWN)
1760 goto failure;
1761
1762 if (atomic_read(&sk->sk_wmem_alloc) >= sk->sk_sndbuf) {
1763 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1764 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1765 err = -EAGAIN;
1766 if (!timeo)
1767 goto failure;
1768 if (signal_pending(current))
1769 goto interrupted;
1770 timeo = sock_wait_for_wmem(sk, timeo);
1771 continue;
1772 }
1773
1774 err = -ENOBUFS;
1775 gfp_mask = sk->sk_allocation;
1776 if (gfp_mask & __GFP_WAIT)
1777 gfp_mask |= __GFP_REPEAT;
1778
1779 skb = alloc_skb(header_len, gfp_mask);
1780 if (!skb)
1781 goto failure;
1782
1783 skb->truesize += data_len;
1784
1785 for (i = 0; npages > 0; i++) {
1786 int order = max_page_order;
1787
1788 while (order) {
1789 if (npages >= 1 << order) {
1790 page = alloc_pages(sk->sk_allocation |
1791 __GFP_COMP | __GFP_NOWARN,
1792 order);
1793 if (page)
1794 goto fill_page;
1795 }
1796 order--;
1797 }
1798 page = alloc_page(sk->sk_allocation);
1799 if (!page)
1800 goto failure;
1801 fill_page:
1802 chunk = min_t(unsigned long, data_len,
1803 PAGE_SIZE << order);
1804 skb_fill_page_desc(skb, i, page, 0, chunk);
1805 data_len -= chunk;
1806 npages -= 1 << order;
1807 }
1808 }
1809
1810 skb_set_owner_w(skb, sk);
1811 return skb;
1812
1813 interrupted:
1814 err = sock_intr_errno(timeo);
1815 failure:
1816 kfree_skb(skb);
1817 *errcode = err;
1818 return NULL;
1819 }
1820 EXPORT_SYMBOL(sock_alloc_send_pskb);
1821
1822 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1823 int noblock, int *errcode)
1824 {
1825 return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1826 }
1827 EXPORT_SYMBOL(sock_alloc_send_skb);
1828
1829 /* On 32bit arches, an skb frag is limited to 2^15 */
1830 #define SKB_FRAG_PAGE_ORDER get_order(32768)
1831
1832 /**
1833 * skb_page_frag_refill - check that a page_frag contains enough room
1834 * @sz: minimum size of the fragment we want to get
1835 * @pfrag: pointer to page_frag
1836 * @prio: priority for memory allocation
1837 *
1838 * Note: While this allocator tries to use high order pages, there is
1839 * no guarantee that allocations succeed. Therefore, @sz MUST be
1840 * less or equal than PAGE_SIZE.
1841 */
1842 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio)
1843 {
1844 int order;
1845
1846 if (pfrag->page) {
1847 if (atomic_read(&pfrag->page->_count) == 1) {
1848 pfrag->offset = 0;
1849 return true;
1850 }
1851 if (pfrag->offset + sz <= pfrag->size)
1852 return true;
1853 put_page(pfrag->page);
1854 }
1855
1856 /* We restrict high order allocations to users that can afford to wait */
1857 order = (prio & __GFP_WAIT) ? SKB_FRAG_PAGE_ORDER : 0;
1858
1859 do {
1860 gfp_t gfp = prio;
1861
1862 if (order)
1863 gfp |= __GFP_COMP | __GFP_NOWARN;
1864 pfrag->page = alloc_pages(gfp, order);
1865 if (likely(pfrag->page)) {
1866 pfrag->offset = 0;
1867 pfrag->size = PAGE_SIZE << order;
1868 return true;
1869 }
1870 } while (--order >= 0);
1871
1872 return false;
1873 }
1874 EXPORT_SYMBOL(skb_page_frag_refill);
1875
1876 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1877 {
1878 if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1879 return true;
1880
1881 sk_enter_memory_pressure(sk);
1882 sk_stream_moderate_sndbuf(sk);
1883 return false;
1884 }
1885 EXPORT_SYMBOL(sk_page_frag_refill);
1886
1887 static void __lock_sock(struct sock *sk)
1888 __releases(&sk->sk_lock.slock)
1889 __acquires(&sk->sk_lock.slock)
1890 {
1891 DEFINE_WAIT(wait);
1892
1893 for (;;) {
1894 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1895 TASK_UNINTERRUPTIBLE);
1896 spin_unlock_bh(&sk->sk_lock.slock);
1897 schedule();
1898 spin_lock_bh(&sk->sk_lock.slock);
1899 if (!sock_owned_by_user(sk))
1900 break;
1901 }
1902 finish_wait(&sk->sk_lock.wq, &wait);
1903 }
1904
1905 static void __release_sock(struct sock *sk)
1906 __releases(&sk->sk_lock.slock)
1907 __acquires(&sk->sk_lock.slock)
1908 {
1909 struct sk_buff *skb = sk->sk_backlog.head;
1910
1911 do {
1912 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1913 bh_unlock_sock(sk);
1914
1915 do {
1916 struct sk_buff *next = skb->next;
1917
1918 prefetch(next);
1919 WARN_ON_ONCE(skb_dst_is_noref(skb));
1920 skb->next = NULL;
1921 sk_backlog_rcv(sk, skb);
1922
1923 /*
1924 * We are in process context here with softirqs
1925 * disabled, use cond_resched_softirq() to preempt.
1926 * This is safe to do because we've taken the backlog
1927 * queue private:
1928 */
1929 cond_resched_softirq();
1930
1931 skb = next;
1932 } while (skb != NULL);
1933
1934 bh_lock_sock(sk);
1935 } while ((skb = sk->sk_backlog.head) != NULL);
1936
1937 /*
1938 * Doing the zeroing here guarantee we can not loop forever
1939 * while a wild producer attempts to flood us.
1940 */
1941 sk->sk_backlog.len = 0;
1942 }
1943
1944 /**
1945 * sk_wait_data - wait for data to arrive at sk_receive_queue
1946 * @sk: sock to wait on
1947 * @timeo: for how long
1948 *
1949 * Now socket state including sk->sk_err is changed only under lock,
1950 * hence we may omit checks after joining wait queue.
1951 * We check receive queue before schedule() only as optimization;
1952 * it is very likely that release_sock() added new data.
1953 */
1954 int sk_wait_data(struct sock *sk, long *timeo)
1955 {
1956 int rc;
1957 DEFINE_WAIT(wait);
1958
1959 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1960 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1961 rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1962 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1963 finish_wait(sk_sleep(sk), &wait);
1964 return rc;
1965 }
1966 EXPORT_SYMBOL(sk_wait_data);
1967
1968 /**
1969 * __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1970 * @sk: socket
1971 * @size: memory size to allocate
1972 * @kind: allocation type
1973 *
1974 * If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1975 * rmem allocation. This function assumes that protocols which have
1976 * memory_pressure use sk_wmem_queued as write buffer accounting.
1977 */
1978 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1979 {
1980 struct proto *prot = sk->sk_prot;
1981 int amt = sk_mem_pages(size);
1982 long allocated;
1983 int parent_status = UNDER_LIMIT;
1984
1985 sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1986
1987 allocated = sk_memory_allocated_add(sk, amt, &parent_status);
1988
1989 /* Under limit. */
1990 if (parent_status == UNDER_LIMIT &&
1991 allocated <= sk_prot_mem_limits(sk, 0)) {
1992 sk_leave_memory_pressure(sk);
1993 return 1;
1994 }
1995
1996 /* Under pressure. (we or our parents) */
1997 if ((parent_status > SOFT_LIMIT) ||
1998 allocated > sk_prot_mem_limits(sk, 1))
1999 sk_enter_memory_pressure(sk);
2000
2001 /* Over hard limit (we or our parents) */
2002 if ((parent_status == OVER_LIMIT) ||
2003 (allocated > sk_prot_mem_limits(sk, 2)))
2004 goto suppress_allocation;
2005
2006 /* guarantee minimum buffer size under pressure */
2007 if (kind == SK_MEM_RECV) {
2008 if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2009 return 1;
2010
2011 } else { /* SK_MEM_SEND */
2012 if (sk->sk_type == SOCK_STREAM) {
2013 if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2014 return 1;
2015 } else if (atomic_read(&sk->sk_wmem_alloc) <
2016 prot->sysctl_wmem[0])
2017 return 1;
2018 }
2019
2020 if (sk_has_memory_pressure(sk)) {
2021 int alloc;
2022
2023 if (!sk_under_memory_pressure(sk))
2024 return 1;
2025 alloc = sk_sockets_allocated_read_positive(sk);
2026 if (sk_prot_mem_limits(sk, 2) > alloc *
2027 sk_mem_pages(sk->sk_wmem_queued +
2028 atomic_read(&sk->sk_rmem_alloc) +
2029 sk->sk_forward_alloc))
2030 return 1;
2031 }
2032
2033 suppress_allocation:
2034
2035 if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2036 sk_stream_moderate_sndbuf(sk);
2037
2038 /* Fail only if socket is _under_ its sndbuf.
2039 * In this case we cannot block, so that we have to fail.
2040 */
2041 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2042 return 1;
2043 }
2044
2045 trace_sock_exceed_buf_limit(sk, prot, allocated);
2046
2047 /* Alas. Undo changes. */
2048 sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2049
2050 sk_memory_allocated_sub(sk, amt);
2051
2052 return 0;
2053 }
2054 EXPORT_SYMBOL(__sk_mem_schedule);
2055
2056 /**
2057 * __sk_reclaim - reclaim memory_allocated
2058 * @sk: socket
2059 */
2060 void __sk_mem_reclaim(struct sock *sk)
2061 {
2062 sk_memory_allocated_sub(sk,
2063 sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
2064 sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
2065
2066 if (sk_under_memory_pressure(sk) &&
2067 (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2068 sk_leave_memory_pressure(sk);
2069 }
2070 EXPORT_SYMBOL(__sk_mem_reclaim);
2071
2072
2073 /*
2074 * Set of default routines for initialising struct proto_ops when
2075 * the protocol does not support a particular function. In certain
2076 * cases where it makes no sense for a protocol to have a "do nothing"
2077 * function, some default processing is provided.
2078 */
2079
2080 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2081 {
2082 return -EOPNOTSUPP;
2083 }
2084 EXPORT_SYMBOL(sock_no_bind);
2085
2086 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2087 int len, int flags)
2088 {
2089 return -EOPNOTSUPP;
2090 }
2091 EXPORT_SYMBOL(sock_no_connect);
2092
2093 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2094 {
2095 return -EOPNOTSUPP;
2096 }
2097 EXPORT_SYMBOL(sock_no_socketpair);
2098
2099 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2100 {
2101 return -EOPNOTSUPP;
2102 }
2103 EXPORT_SYMBOL(sock_no_accept);
2104
2105 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2106 int *len, int peer)
2107 {
2108 return -EOPNOTSUPP;
2109 }
2110 EXPORT_SYMBOL(sock_no_getname);
2111
2112 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2113 {
2114 return 0;
2115 }
2116 EXPORT_SYMBOL(sock_no_poll);
2117
2118 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2119 {
2120 return -EOPNOTSUPP;
2121 }
2122 EXPORT_SYMBOL(sock_no_ioctl);
2123
2124 int sock_no_listen(struct socket *sock, int backlog)
2125 {
2126 return -EOPNOTSUPP;
2127 }
2128 EXPORT_SYMBOL(sock_no_listen);
2129
2130 int sock_no_shutdown(struct socket *sock, int how)
2131 {
2132 return -EOPNOTSUPP;
2133 }
2134 EXPORT_SYMBOL(sock_no_shutdown);
2135
2136 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2137 char __user *optval, unsigned int optlen)
2138 {
2139 return -EOPNOTSUPP;
2140 }
2141 EXPORT_SYMBOL(sock_no_setsockopt);
2142
2143 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2144 char __user *optval, int __user *optlen)
2145 {
2146 return -EOPNOTSUPP;
2147 }
2148 EXPORT_SYMBOL(sock_no_getsockopt);
2149
2150 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2151 size_t len)
2152 {
2153 return -EOPNOTSUPP;
2154 }
2155 EXPORT_SYMBOL(sock_no_sendmsg);
2156
2157 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2158 size_t len, int flags)
2159 {
2160 return -EOPNOTSUPP;
2161 }
2162 EXPORT_SYMBOL(sock_no_recvmsg);
2163
2164 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2165 {
2166 /* Mirror missing mmap method error code */
2167 return -ENODEV;
2168 }
2169 EXPORT_SYMBOL(sock_no_mmap);
2170
2171 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2172 {
2173 ssize_t res;
2174 struct msghdr msg = {.msg_flags = flags};
2175 struct kvec iov;
2176 char *kaddr = kmap(page);
2177 iov.iov_base = kaddr + offset;
2178 iov.iov_len = size;
2179 res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2180 kunmap(page);
2181 return res;
2182 }
2183 EXPORT_SYMBOL(sock_no_sendpage);
2184
2185 /*
2186 * Default Socket Callbacks
2187 */
2188
2189 static void sock_def_wakeup(struct sock *sk)
2190 {
2191 struct socket_wq *wq;
2192
2193 rcu_read_lock();
2194 wq = rcu_dereference(sk->sk_wq);
2195 if (wq_has_sleeper(wq))
2196 wake_up_interruptible_all(&wq->wait);
2197 rcu_read_unlock();
2198 }
2199
2200 static void sock_def_error_report(struct sock *sk)
2201 {
2202 struct socket_wq *wq;
2203
2204 rcu_read_lock();
2205 wq = rcu_dereference(sk->sk_wq);
2206 if (wq_has_sleeper(wq))
2207 wake_up_interruptible_poll(&wq->wait, POLLERR);
2208 sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2209 rcu_read_unlock();
2210 }
2211
2212 static void sock_def_readable(struct sock *sk, int len)
2213 {
2214 struct socket_wq *wq;
2215
2216 rcu_read_lock();
2217 wq = rcu_dereference(sk->sk_wq);
2218 if (wq_has_sleeper(wq))
2219 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2220 POLLRDNORM | POLLRDBAND);
2221 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2222 rcu_read_unlock();
2223 }
2224
2225 static void sock_def_write_space(struct sock *sk)
2226 {
2227 struct socket_wq *wq;
2228
2229 rcu_read_lock();
2230
2231 /* Do not wake up a writer until he can make "significant"
2232 * progress. --DaveM
2233 */
2234 if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2235 wq = rcu_dereference(sk->sk_wq);
2236 if (wq_has_sleeper(wq))
2237 wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2238 POLLWRNORM | POLLWRBAND);
2239
2240 /* Should agree with poll, otherwise some programs break */
2241 if (sock_writeable(sk))
2242 sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2243 }
2244
2245 rcu_read_unlock();
2246 }
2247
2248 static void sock_def_destruct(struct sock *sk)
2249 {
2250 kfree(sk->sk_protinfo);
2251 }
2252
2253 void sk_send_sigurg(struct sock *sk)
2254 {
2255 if (sk->sk_socket && sk->sk_socket->file)
2256 if (send_sigurg(&sk->sk_socket->file->f_owner))
2257 sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2258 }
2259 EXPORT_SYMBOL(sk_send_sigurg);
2260
2261 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2262 unsigned long expires)
2263 {
2264 if (!mod_timer(timer, expires))
2265 sock_hold(sk);
2266 }
2267 EXPORT_SYMBOL(sk_reset_timer);
2268
2269 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2270 {
2271 if (del_timer(timer))
2272 __sock_put(sk);
2273 }
2274 EXPORT_SYMBOL(sk_stop_timer);
2275
2276 void sock_init_data(struct socket *sock, struct sock *sk)
2277 {
2278 skb_queue_head_init(&sk->sk_receive_queue);
2279 skb_queue_head_init(&sk->sk_write_queue);
2280 skb_queue_head_init(&sk->sk_error_queue);
2281 #ifdef CONFIG_NET_DMA
2282 skb_queue_head_init(&sk->sk_async_wait_queue);
2283 #endif
2284
2285 sk->sk_send_head = NULL;
2286
2287 init_timer(&sk->sk_timer);
2288
2289 sk->sk_allocation = GFP_KERNEL;
2290 sk->sk_rcvbuf = sysctl_rmem_default;
2291 sk->sk_sndbuf = sysctl_wmem_default;
2292 sk->sk_state = TCP_CLOSE;
2293 sk_set_socket(sk, sock);
2294
2295 sock_set_flag(sk, SOCK_ZAPPED);
2296
2297 if (sock) {
2298 sk->sk_type = sock->type;
2299 sk->sk_wq = sock->wq;
2300 sock->sk = sk;
2301 } else
2302 sk->sk_wq = NULL;
2303
2304 spin_lock_init(&sk->sk_dst_lock);
2305 rwlock_init(&sk->sk_callback_lock);
2306 lockdep_set_class_and_name(&sk->sk_callback_lock,
2307 af_callback_keys + sk->sk_family,
2308 af_family_clock_key_strings[sk->sk_family]);
2309
2310 sk->sk_state_change = sock_def_wakeup;
2311 sk->sk_data_ready = sock_def_readable;
2312 sk->sk_write_space = sock_def_write_space;
2313 sk->sk_error_report = sock_def_error_report;
2314 sk->sk_destruct = sock_def_destruct;
2315
2316 sk->sk_frag.page = NULL;
2317 sk->sk_frag.offset = 0;
2318 sk->sk_peek_off = -1;
2319
2320 sk->sk_peer_pid = NULL;
2321 sk->sk_peer_cred = NULL;
2322 sk->sk_write_pending = 0;
2323 sk->sk_rcvlowat = 1;
2324 sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
2325 sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
2326
2327 sk->sk_stamp = ktime_set(-1L, 0);
2328
2329 #ifdef CONFIG_NET_RX_BUSY_POLL
2330 sk->sk_napi_id = 0;
2331 sk->sk_ll_usec = sysctl_net_busy_read;
2332 #endif
2333
2334 sk->sk_max_pacing_rate = ~0U;
2335 sk->sk_pacing_rate = ~0U;
2336 /*
2337 * Before updating sk_refcnt, we must commit prior changes to memory
2338 * (Documentation/RCU/rculist_nulls.txt for details)
2339 */
2340 smp_wmb();
2341 atomic_set(&sk->sk_refcnt, 1);
2342 atomic_set(&sk->sk_drops, 0);
2343 }
2344 EXPORT_SYMBOL(sock_init_data);
2345
2346 void lock_sock_nested(struct sock *sk, int subclass)
2347 {
2348 might_sleep();
2349 spin_lock_bh(&sk->sk_lock.slock);
2350 if (sk->sk_lock.owned)
2351 __lock_sock(sk);
2352 sk->sk_lock.owned = 1;
2353 spin_unlock(&sk->sk_lock.slock);
2354 /*
2355 * The sk_lock has mutex_lock() semantics here:
2356 */
2357 mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2358 local_bh_enable();
2359 }
2360 EXPORT_SYMBOL(lock_sock_nested);
2361
2362 void release_sock(struct sock *sk)
2363 {
2364 /*
2365 * The sk_lock has mutex_unlock() semantics:
2366 */
2367 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2368
2369 spin_lock_bh(&sk->sk_lock.slock);
2370 if (sk->sk_backlog.tail)
2371 __release_sock(sk);
2372
2373 if (sk->sk_prot->release_cb)
2374 sk->sk_prot->release_cb(sk);
2375
2376 sk->sk_lock.owned = 0;
2377 if (waitqueue_active(&sk->sk_lock.wq))
2378 wake_up(&sk->sk_lock.wq);
2379 spin_unlock_bh(&sk->sk_lock.slock);
2380 }
2381 EXPORT_SYMBOL(release_sock);
2382
2383 /**
2384 * lock_sock_fast - fast version of lock_sock
2385 * @sk: socket
2386 *
2387 * This version should be used for very small section, where process wont block
2388 * return false if fast path is taken
2389 * sk_lock.slock locked, owned = 0, BH disabled
2390 * return true if slow path is taken
2391 * sk_lock.slock unlocked, owned = 1, BH enabled
2392 */
2393 bool lock_sock_fast(struct sock *sk)
2394 {
2395 might_sleep();
2396 spin_lock_bh(&sk->sk_lock.slock);
2397
2398 if (!sk->sk_lock.owned)
2399 /*
2400 * Note : We must disable BH
2401 */
2402 return false;
2403
2404 __lock_sock(sk);
2405 sk->sk_lock.owned = 1;
2406 spin_unlock(&sk->sk_lock.slock);
2407 /*
2408 * The sk_lock has mutex_lock() semantics here:
2409 */
2410 mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2411 local_bh_enable();
2412 return true;
2413 }
2414 EXPORT_SYMBOL(lock_sock_fast);
2415
2416 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2417 {
2418 struct timeval tv;
2419 if (!sock_flag(sk, SOCK_TIMESTAMP))
2420 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2421 tv = ktime_to_timeval(sk->sk_stamp);
2422 if (tv.tv_sec == -1)
2423 return -ENOENT;
2424 if (tv.tv_sec == 0) {
2425 sk->sk_stamp = ktime_get_real();
2426 tv = ktime_to_timeval(sk->sk_stamp);
2427 }
2428 return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2429 }
2430 EXPORT_SYMBOL(sock_get_timestamp);
2431
2432 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2433 {
2434 struct timespec ts;
2435 if (!sock_flag(sk, SOCK_TIMESTAMP))
2436 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2437 ts = ktime_to_timespec(sk->sk_stamp);
2438 if (ts.tv_sec == -1)
2439 return -ENOENT;
2440 if (ts.tv_sec == 0) {
2441 sk->sk_stamp = ktime_get_real();
2442 ts = ktime_to_timespec(sk->sk_stamp);
2443 }
2444 return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2445 }
2446 EXPORT_SYMBOL(sock_get_timestampns);
2447
2448 void sock_enable_timestamp(struct sock *sk, int flag)
2449 {
2450 if (!sock_flag(sk, flag)) {
2451 unsigned long previous_flags = sk->sk_flags;
2452
2453 sock_set_flag(sk, flag);
2454 /*
2455 * we just set one of the two flags which require net
2456 * time stamping, but time stamping might have been on
2457 * already because of the other one
2458 */
2459 if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2460 net_enable_timestamp();
2461 }
2462 }
2463
2464 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2465 int level, int type)
2466 {
2467 struct sock_exterr_skb *serr;
2468 struct sk_buff *skb, *skb2;
2469 int copied, err;
2470
2471 err = -EAGAIN;
2472 skb = skb_dequeue(&sk->sk_error_queue);
2473 if (skb == NULL)
2474 goto out;
2475
2476 copied = skb->len;
2477 if (copied > len) {
2478 msg->msg_flags |= MSG_TRUNC;
2479 copied = len;
2480 }
2481 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2482 if (err)
2483 goto out_free_skb;
2484
2485 sock_recv_timestamp(msg, sk, skb);
2486
2487 serr = SKB_EXT_ERR(skb);
2488 put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2489
2490 msg->msg_flags |= MSG_ERRQUEUE;
2491 err = copied;
2492
2493 /* Reset and regenerate socket error */
2494 spin_lock_bh(&sk->sk_error_queue.lock);
2495 sk->sk_err = 0;
2496 if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2497 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2498 spin_unlock_bh(&sk->sk_error_queue.lock);
2499 sk->sk_error_report(sk);
2500 } else
2501 spin_unlock_bh(&sk->sk_error_queue.lock);
2502
2503 out_free_skb:
2504 kfree_skb(skb);
2505 out:
2506 return err;
2507 }
2508 EXPORT_SYMBOL(sock_recv_errqueue);
2509
2510 /*
2511 * Get a socket option on an socket.
2512 *
2513 * FIX: POSIX 1003.1g is very ambiguous here. It states that
2514 * asynchronous errors should be reported by getsockopt. We assume
2515 * this means if you specify SO_ERROR (otherwise whats the point of it).
2516 */
2517 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2518 char __user *optval, int __user *optlen)
2519 {
2520 struct sock *sk = sock->sk;
2521
2522 return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2523 }
2524 EXPORT_SYMBOL(sock_common_getsockopt);
2525
2526 #ifdef CONFIG_COMPAT
2527 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2528 char __user *optval, int __user *optlen)
2529 {
2530 struct sock *sk = sock->sk;
2531
2532 if (sk->sk_prot->compat_getsockopt != NULL)
2533 return sk->sk_prot->compat_getsockopt(sk, level, optname,
2534 optval, optlen);
2535 return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2536 }
2537 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2538 #endif
2539
2540 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2541 struct msghdr *msg, size_t size, int flags)
2542 {
2543 struct sock *sk = sock->sk;
2544 int addr_len = 0;
2545 int err;
2546
2547 err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2548 flags & ~MSG_DONTWAIT, &addr_len);
2549 if (err >= 0)
2550 msg->msg_namelen = addr_len;
2551 return err;
2552 }
2553 EXPORT_SYMBOL(sock_common_recvmsg);
2554
2555 /*
2556 * Set socket options on an inet socket.
2557 */
2558 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2559 char __user *optval, unsigned int optlen)
2560 {
2561 struct sock *sk = sock->sk;
2562
2563 return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2564 }
2565 EXPORT_SYMBOL(sock_common_setsockopt);
2566
2567 #ifdef CONFIG_COMPAT
2568 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2569 char __user *optval, unsigned int optlen)
2570 {
2571 struct sock *sk = sock->sk;
2572
2573 if (sk->sk_prot->compat_setsockopt != NULL)
2574 return sk->sk_prot->compat_setsockopt(sk, level, optname,
2575 optval, optlen);
2576 return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2577 }
2578 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2579 #endif
2580
2581 void sk_common_release(struct sock *sk)
2582 {
2583 if (sk->sk_prot->destroy)
2584 sk->sk_prot->destroy(sk);
2585
2586 /*
2587 * Observation: when sock_common_release is called, processes have
2588 * no access to socket. But net still has.
2589 * Step one, detach it from networking:
2590 *
2591 * A. Remove from hash tables.
2592 */
2593
2594 sk->sk_prot->unhash(sk);
2595
2596 /*
2597 * In this point socket cannot receive new packets, but it is possible
2598 * that some packets are in flight because some CPU runs receiver and
2599 * did hash table lookup before we unhashed socket. They will achieve
2600 * receive queue and will be purged by socket destructor.
2601 *
2602 * Also we still have packets pending on receive queue and probably,
2603 * our own packets waiting in device queues. sock_destroy will drain
2604 * receive queue, but transmitted packets will delay socket destruction
2605 * until the last reference will be released.
2606 */
2607
2608 sock_orphan(sk);
2609
2610 xfrm_sk_free_policy(sk);
2611
2612 sk_refcnt_debug_release(sk);
2613
2614 if (sk->sk_frag.page) {
2615 put_page(sk->sk_frag.page);
2616 sk->sk_frag.page = NULL;
2617 }
2618
2619 sock_put(sk);
2620 }
2621 EXPORT_SYMBOL(sk_common_release);
2622
2623 #ifdef CONFIG_PROC_FS
2624 #define PROTO_INUSE_NR 64 /* should be enough for the first time */
2625 struct prot_inuse {
2626 int val[PROTO_INUSE_NR];
2627 };
2628
2629 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2630
2631 #ifdef CONFIG_NET_NS
2632 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2633 {
2634 __this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2635 }
2636 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2637
2638 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2639 {
2640 int cpu, idx = prot->inuse_idx;
2641 int res = 0;
2642
2643 for_each_possible_cpu(cpu)
2644 res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2645
2646 return res >= 0 ? res : 0;
2647 }
2648 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2649
2650 static int __net_init sock_inuse_init_net(struct net *net)
2651 {
2652 net->core.inuse = alloc_percpu(struct prot_inuse);
2653 return net->core.inuse ? 0 : -ENOMEM;
2654 }
2655
2656 static void __net_exit sock_inuse_exit_net(struct net *net)
2657 {
2658 free_percpu(net->core.inuse);
2659 }
2660
2661 static struct pernet_operations net_inuse_ops = {
2662 .init = sock_inuse_init_net,
2663 .exit = sock_inuse_exit_net,
2664 };
2665
2666 static __init int net_inuse_init(void)
2667 {
2668 if (register_pernet_subsys(&net_inuse_ops))
2669 panic("Cannot initialize net inuse counters");
2670
2671 return 0;
2672 }
2673
2674 core_initcall(net_inuse_init);
2675 #else
2676 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2677
2678 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2679 {
2680 __this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2681 }
2682 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2683
2684 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2685 {
2686 int cpu, idx = prot->inuse_idx;
2687 int res = 0;
2688
2689 for_each_possible_cpu(cpu)
2690 res += per_cpu(prot_inuse, cpu).val[idx];
2691
2692 return res >= 0 ? res : 0;
2693 }
2694 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2695 #endif
2696
2697 static void assign_proto_idx(struct proto *prot)
2698 {
2699 prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2700
2701 if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2702 pr_err("PROTO_INUSE_NR exhausted\n");
2703 return;
2704 }
2705
2706 set_bit(prot->inuse_idx, proto_inuse_idx);
2707 }
2708
2709 static void release_proto_idx(struct proto *prot)
2710 {
2711 if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2712 clear_bit(prot->inuse_idx, proto_inuse_idx);
2713 }
2714 #else
2715 static inline void assign_proto_idx(struct proto *prot)
2716 {
2717 }
2718
2719 static inline void release_proto_idx(struct proto *prot)
2720 {
2721 }
2722 #endif
2723
2724 int proto_register(struct proto *prot, int alloc_slab)
2725 {
2726 if (alloc_slab) {
2727 prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2728 SLAB_HWCACHE_ALIGN | prot->slab_flags,
2729 NULL);
2730
2731 if (prot->slab == NULL) {
2732 pr_crit("%s: Can't create sock SLAB cache!\n",
2733 prot->name);
2734 goto out;
2735 }
2736
2737 if (prot->rsk_prot != NULL) {
2738 prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2739 if (prot->rsk_prot->slab_name == NULL)
2740 goto out_free_sock_slab;
2741
2742 prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2743 prot->rsk_prot->obj_size, 0,
2744 SLAB_HWCACHE_ALIGN, NULL);
2745
2746 if (prot->rsk_prot->slab == NULL) {
2747 pr_crit("%s: Can't create request sock SLAB cache!\n",
2748 prot->name);
2749 goto out_free_request_sock_slab_name;
2750 }
2751 }
2752
2753 if (prot->twsk_prot != NULL) {
2754 prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2755
2756 if (prot->twsk_prot->twsk_slab_name == NULL)
2757 goto out_free_request_sock_slab;
2758
2759 prot->twsk_prot->twsk_slab =
2760 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2761 prot->twsk_prot->twsk_obj_size,
2762 0,
2763 SLAB_HWCACHE_ALIGN |
2764 prot->slab_flags,
2765 NULL);
2766 if (prot->twsk_prot->twsk_slab == NULL)
2767 goto out_free_timewait_sock_slab_name;
2768 }
2769 }
2770
2771 mutex_lock(&proto_list_mutex);
2772 list_add(&prot->node, &proto_list);
2773 assign_proto_idx(prot);
2774 mutex_unlock(&proto_list_mutex);
2775 return 0;
2776
2777 out_free_timewait_sock_slab_name:
2778 kfree(prot->twsk_prot->twsk_slab_name);
2779 out_free_request_sock_slab:
2780 if (prot->rsk_prot && prot->rsk_prot->slab) {
2781 kmem_cache_destroy(prot->rsk_prot->slab);
2782 prot->rsk_prot->slab = NULL;
2783 }
2784 out_free_request_sock_slab_name:
2785 if (prot->rsk_prot)
2786 kfree(prot->rsk_prot->slab_name);
2787 out_free_sock_slab:
2788 kmem_cache_destroy(prot->slab);
2789 prot->slab = NULL;
2790 out:
2791 return -ENOBUFS;
2792 }
2793 EXPORT_SYMBOL(proto_register);
2794
2795 void proto_unregister(struct proto *prot)
2796 {
2797 mutex_lock(&proto_list_mutex);
2798 release_proto_idx(prot);
2799 list_del(&prot->node);
2800 mutex_unlock(&proto_list_mutex);
2801
2802 if (prot->slab != NULL) {
2803 kmem_cache_destroy(prot->slab);
2804 prot->slab = NULL;
2805 }
2806
2807 if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2808 kmem_cache_destroy(prot->rsk_prot->slab);
2809 kfree(prot->rsk_prot->slab_name);
2810 prot->rsk_prot->slab = NULL;
2811 }
2812
2813 if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2814 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2815 kfree(prot->twsk_prot->twsk_slab_name);
2816 prot->twsk_prot->twsk_slab = NULL;
2817 }
2818 }
2819 EXPORT_SYMBOL(proto_unregister);
2820
2821 #ifdef CONFIG_PROC_FS
2822 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2823 __acquires(proto_list_mutex)
2824 {
2825 mutex_lock(&proto_list_mutex);
2826 return seq_list_start_head(&proto_list, *pos);
2827 }
2828
2829 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2830 {
2831 return seq_list_next(v, &proto_list, pos);
2832 }
2833
2834 static void proto_seq_stop(struct seq_file *seq, void *v)
2835 __releases(proto_list_mutex)
2836 {
2837 mutex_unlock(&proto_list_mutex);
2838 }
2839
2840 static char proto_method_implemented(const void *method)
2841 {
2842 return method == NULL ? 'n' : 'y';
2843 }
2844 static long sock_prot_memory_allocated(struct proto *proto)
2845 {
2846 return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2847 }
2848
2849 static char *sock_prot_memory_pressure(struct proto *proto)
2850 {
2851 return proto->memory_pressure != NULL ?
2852 proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2853 }
2854
2855 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2856 {
2857
2858 seq_printf(seq, "%-9s %4u %6d %6ld %-3s %6u %-3s %-10s "
2859 "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2860 proto->name,
2861 proto->obj_size,
2862 sock_prot_inuse_get(seq_file_net(seq), proto),
2863 sock_prot_memory_allocated(proto),
2864 sock_prot_memory_pressure(proto),
2865 proto->max_header,
2866 proto->slab == NULL ? "no" : "yes",
2867 module_name(proto->owner),
2868 proto_method_implemented(proto->close),
2869 proto_method_implemented(proto->connect),
2870 proto_method_implemented(proto->disconnect),
2871 proto_method_implemented(proto->accept),
2872 proto_method_implemented(proto->ioctl),
2873 proto_method_implemented(proto->init),
2874 proto_method_implemented(proto->destroy),
2875 proto_method_implemented(proto->shutdown),
2876 proto_method_implemented(proto->setsockopt),
2877 proto_method_implemented(proto->getsockopt),
2878 proto_method_implemented(proto->sendmsg),
2879 proto_method_implemented(proto->recvmsg),
2880 proto_method_implemented(proto->sendpage),
2881 proto_method_implemented(proto->bind),
2882 proto_method_implemented(proto->backlog_rcv),
2883 proto_method_implemented(proto->hash),
2884 proto_method_implemented(proto->unhash),
2885 proto_method_implemented(proto->get_port),
2886 proto_method_implemented(proto->enter_memory_pressure));
2887 }
2888
2889 static int proto_seq_show(struct seq_file *seq, void *v)
2890 {
2891 if (v == &proto_list)
2892 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2893 "protocol",
2894 "size",
2895 "sockets",
2896 "memory",
2897 "press",
2898 "maxhdr",
2899 "slab",
2900 "module",
2901 "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2902 else
2903 proto_seq_printf(seq, list_entry(v, struct proto, node));
2904 return 0;
2905 }
2906
2907 static const struct seq_operations proto_seq_ops = {
2908 .start = proto_seq_start,
2909 .next = proto_seq_next,
2910 .stop = proto_seq_stop,
2911 .show = proto_seq_show,
2912 };
2913
2914 static int proto_seq_open(struct inode *inode, struct file *file)
2915 {
2916 return seq_open_net(inode, file, &proto_seq_ops,
2917 sizeof(struct seq_net_private));
2918 }
2919
2920 static const struct file_operations proto_seq_fops = {
2921 .owner = THIS_MODULE,
2922 .open = proto_seq_open,
2923 .read = seq_read,
2924 .llseek = seq_lseek,
2925 .release = seq_release_net,
2926 };
2927
2928 static __net_init int proto_init_net(struct net *net)
2929 {
2930 if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
2931 return -ENOMEM;
2932
2933 return 0;
2934 }
2935
2936 static __net_exit void proto_exit_net(struct net *net)
2937 {
2938 remove_proc_entry("protocols", net->proc_net);
2939 }
2940
2941
2942 static __net_initdata struct pernet_operations proto_net_ops = {
2943 .init = proto_init_net,
2944 .exit = proto_exit_net,
2945 };
2946
2947 static int __init proto_init(void)
2948 {
2949 return register_pernet_subsys(&proto_net_ops);
2950 }
2951
2952 subsys_initcall(proto_init);
2953
2954 #endif /* PROC_FS */
Linux kernel - Deliverables
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