Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/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 /**
149  * sk_ns_capable - General socket capability test
150  * @sk: Socket to use a capability on or through
151  * @user_ns: The user namespace of the capability to use
152  * @cap: The capability to use
153  *
154  * Test to see if the opener of the socket had when the socket was
155  * created and the current process has the capability @cap in the user
156  * namespace @user_ns.
157  */
158 bool sk_ns_capable(const struct sock *sk,
159                    struct user_namespace *user_ns, int cap)
160 {
161         return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
162                 ns_capable(user_ns, cap);
163 }
164 EXPORT_SYMBOL(sk_ns_capable);
165 
166 /**
167  * sk_capable - Socket global capability test
168  * @sk: Socket to use a capability on or through
169  * @cap: The global capbility to use
170  *
171  * Test to see if the opener of the socket had when the socket was
172  * created and the current process has the capability @cap in all user
173  * namespaces.
174  */
175 bool sk_capable(const struct sock *sk, int cap)
176 {
177         return sk_ns_capable(sk, &init_user_ns, cap);
178 }
179 EXPORT_SYMBOL(sk_capable);
180 
181 /**
182  * sk_net_capable - Network namespace socket capability test
183  * @sk: Socket to use a capability on or through
184  * @cap: The capability to use
185  *
186  * Test to see if the opener of the socket had when the socke was created
187  * and the current process has the capability @cap over the network namespace
188  * the socket is a member of.
189  */
190 bool sk_net_capable(const struct sock *sk, int cap)
191 {
192         return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
193 }
194 EXPORT_SYMBOL(sk_net_capable);
195 
196 
197 #ifdef CONFIG_MEMCG_KMEM
198 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
199 {
200         struct proto *proto;
201         int ret = 0;
202 
203         mutex_lock(&proto_list_mutex);
204         list_for_each_entry(proto, &proto_list, node) {
205                 if (proto->init_cgroup) {
206                         ret = proto->init_cgroup(memcg, ss);
207                         if (ret)
208                                 goto out;
209                 }
210         }
211 
212         mutex_unlock(&proto_list_mutex);
213         return ret;
214 out:
215         list_for_each_entry_continue_reverse(proto, &proto_list, node)
216                 if (proto->destroy_cgroup)
217                         proto->destroy_cgroup(memcg);
218         mutex_unlock(&proto_list_mutex);
219         return ret;
220 }
221 
222 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
223 {
224         struct proto *proto;
225 
226         mutex_lock(&proto_list_mutex);
227         list_for_each_entry_reverse(proto, &proto_list, node)
228                 if (proto->destroy_cgroup)
229                         proto->destroy_cgroup(memcg);
230         mutex_unlock(&proto_list_mutex);
231 }
232 #endif
233 
234 /*
235  * Each address family might have different locking rules, so we have
236  * one slock key per address family:
237  */
238 static struct lock_class_key af_family_keys[AF_MAX];
239 static struct lock_class_key af_family_slock_keys[AF_MAX];
240 
241 #if defined(CONFIG_MEMCG_KMEM)
242 struct static_key memcg_socket_limit_enabled;
243 EXPORT_SYMBOL(memcg_socket_limit_enabled);
244 #endif
245 
246 /*
247  * Make lock validator output more readable. (we pre-construct these
248  * strings build-time, so that runtime initialization of socket
249  * locks is fast):
250  */
251 static const char *const af_family_key_strings[AF_MAX+1] = {
252   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
253   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
254   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
255   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
256   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
257   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
258   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
259   "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
260   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
261   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
262   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
263   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
264   "sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG"      ,
265   "sk_lock-AF_NFC"   , "sk_lock-AF_VSOCK"    , "sk_lock-AF_MAX"
266 };
267 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
268   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
269   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
270   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
271   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
272   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
273   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
274   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
275   "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
276   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
277   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
278   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
279   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
280   "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG"      ,
281   "slock-AF_NFC"   , "slock-AF_VSOCK"    ,"slock-AF_MAX"
282 };
283 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
284   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
285   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
286   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
287   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
288   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
289   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
290   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
291   "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
292   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
293   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
294   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
295   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
296   "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG"      ,
297   "clock-AF_NFC"   , "clock-AF_VSOCK"    , "clock-AF_MAX"
298 };
299 
300 /*
301  * sk_callback_lock locking rules are per-address-family,
302  * so split the lock classes by using a per-AF key:
303  */
304 static struct lock_class_key af_callback_keys[AF_MAX];
305 
306 /* Take into consideration the size of the struct sk_buff overhead in the
307  * determination of these values, since that is non-constant across
308  * platforms.  This makes socket queueing behavior and performance
309  * not depend upon such differences.
310  */
311 #define _SK_MEM_PACKETS         256
312 #define _SK_MEM_OVERHEAD        SKB_TRUESIZE(256)
313 #define SK_WMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
314 #define SK_RMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
315 
316 /* Run time adjustable parameters. */
317 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
318 EXPORT_SYMBOL(sysctl_wmem_max);
319 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
320 EXPORT_SYMBOL(sysctl_rmem_max);
321 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
322 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
323 
324 /* Maximal space eaten by iovec or ancillary data plus some space */
325 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
326 EXPORT_SYMBOL(sysctl_optmem_max);
327 
328 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
329 EXPORT_SYMBOL_GPL(memalloc_socks);
330 
331 /**
332  * sk_set_memalloc - sets %SOCK_MEMALLOC
333  * @sk: socket to set it on
334  *
335  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
336  * It's the responsibility of the admin to adjust min_free_kbytes
337  * to meet the requirements
338  */
339 void sk_set_memalloc(struct sock *sk)
340 {
341         sock_set_flag(sk, SOCK_MEMALLOC);
342         sk->sk_allocation |= __GFP_MEMALLOC;
343         static_key_slow_inc(&memalloc_socks);
344 }
345 EXPORT_SYMBOL_GPL(sk_set_memalloc);
346 
347 void sk_clear_memalloc(struct sock *sk)
348 {
349         sock_reset_flag(sk, SOCK_MEMALLOC);
350         sk->sk_allocation &= ~__GFP_MEMALLOC;
351         static_key_slow_dec(&memalloc_socks);
352 
353         /*
354          * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
355          * progress of swapping. However, if SOCK_MEMALLOC is cleared while
356          * it has rmem allocations there is a risk that the user of the
357          * socket cannot make forward progress due to exceeding the rmem
358          * limits. By rights, sk_clear_memalloc() should only be called
359          * on sockets being torn down but warn and reset the accounting if
360          * that assumption breaks.
361          */
362         if (WARN_ON(sk->sk_forward_alloc))
363                 sk_mem_reclaim(sk);
364 }
365 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
366 
367 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
368 {
369         int ret;
370         unsigned long pflags = current->flags;
371 
372         /* these should have been dropped before queueing */
373         BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
374 
375         current->flags |= PF_MEMALLOC;
376         ret = sk->sk_backlog_rcv(sk, skb);
377         tsk_restore_flags(current, pflags, PF_MEMALLOC);
378 
379         return ret;
380 }
381 EXPORT_SYMBOL(__sk_backlog_rcv);
382 
383 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
384 {
385         struct timeval tv;
386 
387         if (optlen < sizeof(tv))
388                 return -EINVAL;
389         if (copy_from_user(&tv, optval, sizeof(tv)))
390                 return -EFAULT;
391         if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
392                 return -EDOM;
393 
394         if (tv.tv_sec < 0) {
395                 static int warned __read_mostly;
396 
397                 *timeo_p = 0;
398                 if (warned < 10 && net_ratelimit()) {
399                         warned++;
400                         pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
401                                 __func__, current->comm, task_pid_nr(current));
402                 }
403                 return 0;
404         }
405         *timeo_p = MAX_SCHEDULE_TIMEOUT;
406         if (tv.tv_sec == 0 && tv.tv_usec == 0)
407                 return 0;
408         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
409                 *timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
410         return 0;
411 }
412 
413 static void sock_warn_obsolete_bsdism(const char *name)
414 {
415         static int warned;
416         static char warncomm[TASK_COMM_LEN];
417         if (strcmp(warncomm, current->comm) && warned < 5) {
418                 strcpy(warncomm,  current->comm);
419                 pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
420                         warncomm, name);
421                 warned++;
422         }
423 }
424 
425 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
426 
427 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
428 {
429         if (sk->sk_flags & flags) {
430                 sk->sk_flags &= ~flags;
431                 if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
432                         net_disable_timestamp();
433         }
434 }
435 
436 
437 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
438 {
439         int err;
440         int skb_len;
441         unsigned long flags;
442         struct sk_buff_head *list = &sk->sk_receive_queue;
443 
444         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
445                 atomic_inc(&sk->sk_drops);
446                 trace_sock_rcvqueue_full(sk, skb);
447                 return -ENOMEM;
448         }
449 
450         err = sk_filter(sk, skb);
451         if (err)
452                 return err;
453 
454         if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
455                 atomic_inc(&sk->sk_drops);
456                 return -ENOBUFS;
457         }
458 
459         skb->dev = NULL;
460         skb_set_owner_r(skb, sk);
461 
462         /* Cache the SKB length before we tack it onto the receive
463          * queue.  Once it is added it no longer belongs to us and
464          * may be freed by other threads of control pulling packets
465          * from the queue.
466          */
467         skb_len = skb->len;
468 
469         /* we escape from rcu protected region, make sure we dont leak
470          * a norefcounted dst
471          */
472         skb_dst_force(skb);
473 
474         spin_lock_irqsave(&list->lock, flags);
475         skb->dropcount = atomic_read(&sk->sk_drops);
476         __skb_queue_tail(list, skb);
477         spin_unlock_irqrestore(&list->lock, flags);
478 
479         if (!sock_flag(sk, SOCK_DEAD))
480                 sk->sk_data_ready(sk);
481         return 0;
482 }
483 EXPORT_SYMBOL(sock_queue_rcv_skb);
484 
485 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
486 {
487         int rc = NET_RX_SUCCESS;
488 
489         if (sk_filter(sk, skb))
490                 goto discard_and_relse;
491 
492         skb->dev = NULL;
493 
494         if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) {
495                 atomic_inc(&sk->sk_drops);
496                 goto discard_and_relse;
497         }
498         if (nested)
499                 bh_lock_sock_nested(sk);
500         else
501                 bh_lock_sock(sk);
502         if (!sock_owned_by_user(sk)) {
503                 /*
504                  * trylock + unlock semantics:
505                  */
506                 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
507 
508                 rc = sk_backlog_rcv(sk, skb);
509 
510                 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
511         } else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
512                 bh_unlock_sock(sk);
513                 atomic_inc(&sk->sk_drops);
514                 goto discard_and_relse;
515         }
516 
517         bh_unlock_sock(sk);
518 out:
519         sock_put(sk);
520         return rc;
521 discard_and_relse:
522         kfree_skb(skb);
523         goto out;
524 }
525 EXPORT_SYMBOL(sk_receive_skb);
526 
527 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
528 {
529         struct dst_entry *dst = __sk_dst_get(sk);
530 
531         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
532                 sk_tx_queue_clear(sk);
533                 RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
534                 dst_release(dst);
535                 return NULL;
536         }
537 
538         return dst;
539 }
540 EXPORT_SYMBOL(__sk_dst_check);
541 
542 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
543 {
544         struct dst_entry *dst = sk_dst_get(sk);
545 
546         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
547                 sk_dst_reset(sk);
548                 dst_release(dst);
549                 return NULL;
550         }
551 
552         return dst;
553 }
554 EXPORT_SYMBOL(sk_dst_check);
555 
556 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
557                                 int optlen)
558 {
559         int ret = -ENOPROTOOPT;
560 #ifdef CONFIG_NETDEVICES
561         struct net *net = sock_net(sk);
562         char devname[IFNAMSIZ];
563         int index;
564 
565         /* Sorry... */
566         ret = -EPERM;
567         if (!ns_capable(net->user_ns, CAP_NET_RAW))
568                 goto out;
569 
570         ret = -EINVAL;
571         if (optlen < 0)
572                 goto out;
573 
574         /* Bind this socket to a particular device like "eth0",
575          * as specified in the passed interface name. If the
576          * name is "" or the option length is zero the socket
577          * is not bound.
578          */
579         if (optlen > IFNAMSIZ - 1)
580                 optlen = IFNAMSIZ - 1;
581         memset(devname, 0, sizeof(devname));
582 
583         ret = -EFAULT;
584         if (copy_from_user(devname, optval, optlen))
585                 goto out;
586 
587         index = 0;
588         if (devname[0] != '\0') {
589                 struct net_device *dev;
590 
591                 rcu_read_lock();
592                 dev = dev_get_by_name_rcu(net, devname);
593                 if (dev)
594                         index = dev->ifindex;
595                 rcu_read_unlock();
596                 ret = -ENODEV;
597                 if (!dev)
598                         goto out;
599         }
600 
601         lock_sock(sk);
602         sk->sk_bound_dev_if = index;
603         sk_dst_reset(sk);
604         release_sock(sk);
605 
606         ret = 0;
607 
608 out:
609 #endif
610 
611         return ret;
612 }
613 
614 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
615                                 int __user *optlen, int len)
616 {
617         int ret = -ENOPROTOOPT;
618 #ifdef CONFIG_NETDEVICES
619         struct net *net = sock_net(sk);
620         char devname[IFNAMSIZ];
621 
622         if (sk->sk_bound_dev_if == 0) {
623                 len = 0;
624                 goto zero;
625         }
626 
627         ret = -EINVAL;
628         if (len < IFNAMSIZ)
629                 goto out;
630 
631         ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
632         if (ret)
633                 goto out;
634 
635         len = strlen(devname) + 1;
636 
637         ret = -EFAULT;
638         if (copy_to_user(optval, devname, len))
639                 goto out;
640 
641 zero:
642         ret = -EFAULT;
643         if (put_user(len, optlen))
644                 goto out;
645 
646         ret = 0;
647 
648 out:
649 #endif
650 
651         return ret;
652 }
653 
654 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
655 {
656         if (valbool)
657                 sock_set_flag(sk, bit);
658         else
659                 sock_reset_flag(sk, bit);
660 }
661 
662 /*
663  *      This is meant for all protocols to use and covers goings on
664  *      at the socket level. Everything here is generic.
665  */
666 
667 int sock_setsockopt(struct socket *sock, int level, int optname,
668                     char __user *optval, unsigned int optlen)
669 {
670         struct sock *sk = sock->sk;
671         int val;
672         int valbool;
673         struct linger ling;
674         int ret = 0;
675 
676         /*
677          *      Options without arguments
678          */
679 
680         if (optname == SO_BINDTODEVICE)
681                 return sock_setbindtodevice(sk, optval, optlen);
682 
683         if (optlen < sizeof(int))
684                 return -EINVAL;
685 
686         if (get_user(val, (int __user *)optval))
687                 return -EFAULT;
688 
689         valbool = val ? 1 : 0;
690 
691         lock_sock(sk);
692 
693         switch (optname) {
694         case SO_DEBUG:
695                 if (val && !capable(CAP_NET_ADMIN))
696                         ret = -EACCES;
697                 else
698                         sock_valbool_flag(sk, SOCK_DBG, valbool);
699                 break;
700         case SO_REUSEADDR:
701                 sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
702                 break;
703         case SO_REUSEPORT:
704                 sk->sk_reuseport = valbool;
705                 break;
706         case SO_TYPE:
707         case SO_PROTOCOL:
708         case SO_DOMAIN:
709         case SO_ERROR:
710                 ret = -ENOPROTOOPT;
711                 break;
712         case SO_DONTROUTE:
713                 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
714                 break;
715         case SO_BROADCAST:
716                 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
717                 break;
718         case SO_SNDBUF:
719                 /* Don't error on this BSD doesn't and if you think
720                  * about it this is right. Otherwise apps have to
721                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
722                  * are treated in BSD as hints
723                  */
724                 val = min_t(u32, val, sysctl_wmem_max);
725 set_sndbuf:
726                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
727                 sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
728                 /* Wake up sending tasks if we upped the value. */
729                 sk->sk_write_space(sk);
730                 break;
731 
732         case SO_SNDBUFFORCE:
733                 if (!capable(CAP_NET_ADMIN)) {
734                         ret = -EPERM;
735                         break;
736                 }
737                 goto set_sndbuf;
738 
739         case SO_RCVBUF:
740                 /* Don't error on this BSD doesn't and if you think
741                  * about it this is right. Otherwise apps have to
742                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
743                  * are treated in BSD as hints
744                  */
745                 val = min_t(u32, val, sysctl_rmem_max);
746 set_rcvbuf:
747                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
748                 /*
749                  * We double it on the way in to account for
750                  * "struct sk_buff" etc. overhead.   Applications
751                  * assume that the SO_RCVBUF setting they make will
752                  * allow that much actual data to be received on that
753                  * socket.
754                  *
755                  * Applications are unaware that "struct sk_buff" and
756                  * other overheads allocate from the receive buffer
757                  * during socket buffer allocation.
758                  *
759                  * And after considering the possible alternatives,
760                  * returning the value we actually used in getsockopt
761                  * is the most desirable behavior.
762                  */
763                 sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
764                 break;
765 
766         case SO_RCVBUFFORCE:
767                 if (!capable(CAP_NET_ADMIN)) {
768                         ret = -EPERM;
769                         break;
770                 }
771                 goto set_rcvbuf;
772 
773         case SO_KEEPALIVE:
774 #ifdef CONFIG_INET
775                 if (sk->sk_protocol == IPPROTO_TCP &&
776                     sk->sk_type == SOCK_STREAM)
777                         tcp_set_keepalive(sk, valbool);
778 #endif
779                 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
780                 break;
781 
782         case SO_OOBINLINE:
783                 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
784                 break;
785 
786         case SO_NO_CHECK:
787                 sk->sk_no_check = valbool;
788                 break;
789 
790         case SO_PRIORITY:
791                 if ((val >= 0 && val <= 6) ||
792                     ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
793                         sk->sk_priority = val;
794                 else
795                         ret = -EPERM;
796                 break;
797 
798         case SO_LINGER:
799                 if (optlen < sizeof(ling)) {
800                         ret = -EINVAL;  /* 1003.1g */
801                         break;
802                 }
803                 if (copy_from_user(&ling, optval, sizeof(ling))) {
804                         ret = -EFAULT;
805                         break;
806                 }
807                 if (!ling.l_onoff)
808                         sock_reset_flag(sk, SOCK_LINGER);
809                 else {
810 #if (BITS_PER_LONG == 32)
811                         if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
812                                 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
813                         else
814 #endif
815                                 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
816                         sock_set_flag(sk, SOCK_LINGER);
817                 }
818                 break;
819 
820         case SO_BSDCOMPAT:
821                 sock_warn_obsolete_bsdism("setsockopt");
822                 break;
823 
824         case SO_PASSCRED:
825                 if (valbool)
826                         set_bit(SOCK_PASSCRED, &sock->flags);
827                 else
828                         clear_bit(SOCK_PASSCRED, &sock->flags);
829                 break;
830 
831         case SO_TIMESTAMP:
832         case SO_TIMESTAMPNS:
833                 if (valbool)  {
834                         if (optname == SO_TIMESTAMP)
835                                 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
836                         else
837                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
838                         sock_set_flag(sk, SOCK_RCVTSTAMP);
839                         sock_enable_timestamp(sk, SOCK_TIMESTAMP);
840                 } else {
841                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
842                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
843                 }
844                 break;
845 
846         case SO_TIMESTAMPING:
847                 if (val & ~SOF_TIMESTAMPING_MASK) {
848                         ret = -EINVAL;
849                         break;
850                 }
851                 sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
852                                   val & SOF_TIMESTAMPING_TX_HARDWARE);
853                 sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
854                                   val & SOF_TIMESTAMPING_TX_SOFTWARE);
855                 sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
856                                   val & SOF_TIMESTAMPING_RX_HARDWARE);
857                 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
858                         sock_enable_timestamp(sk,
859                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
860                 else
861                         sock_disable_timestamp(sk,
862                                                (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
863                 sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
864                                   val & SOF_TIMESTAMPING_SOFTWARE);
865                 sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
866                                   val & SOF_TIMESTAMPING_SYS_HARDWARE);
867                 sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
868                                   val & SOF_TIMESTAMPING_RAW_HARDWARE);
869                 break;
870 
871         case SO_RCVLOWAT:
872                 if (val < 0)
873                         val = INT_MAX;
874                 sk->sk_rcvlowat = val ? : 1;
875                 break;
876 
877         case SO_RCVTIMEO:
878                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
879                 break;
880 
881         case SO_SNDTIMEO:
882                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
883                 break;
884 
885         case SO_ATTACH_FILTER:
886                 ret = -EINVAL;
887                 if (optlen == sizeof(struct sock_fprog)) {
888                         struct sock_fprog fprog;
889 
890                         ret = -EFAULT;
891                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
892                                 break;
893 
894                         ret = sk_attach_filter(&fprog, sk);
895                 }
896                 break;
897 
898         case SO_DETACH_FILTER:
899                 ret = sk_detach_filter(sk);
900                 break;
901 
902         case SO_LOCK_FILTER:
903                 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
904                         ret = -EPERM;
905                 else
906                         sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
907                 break;
908 
909         case SO_PASSSEC:
910                 if (valbool)
911                         set_bit(SOCK_PASSSEC, &sock->flags);
912                 else
913                         clear_bit(SOCK_PASSSEC, &sock->flags);
914                 break;
915         case SO_MARK:
916                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
917                         ret = -EPERM;
918                 else
919                         sk->sk_mark = val;
920                 break;
921 
922                 /* We implement the SO_SNDLOWAT etc to
923                    not be settable (1003.1g 5.3) */
924         case SO_RXQ_OVFL:
925                 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
926                 break;
927 
928         case SO_WIFI_STATUS:
929                 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
930                 break;
931 
932         case SO_PEEK_OFF:
933                 if (sock->ops->set_peek_off)
934                         ret = sock->ops->set_peek_off(sk, val);
935                 else
936                         ret = -EOPNOTSUPP;
937                 break;
938 
939         case SO_NOFCS:
940                 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
941                 break;
942 
943         case SO_SELECT_ERR_QUEUE:
944                 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
945                 break;
946 
947 #ifdef CONFIG_NET_RX_BUSY_POLL
948         case SO_BUSY_POLL:
949                 /* allow unprivileged users to decrease the value */
950                 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
951                         ret = -EPERM;
952                 else {
953                         if (val < 0)
954                                 ret = -EINVAL;
955                         else
956                                 sk->sk_ll_usec = val;
957                 }
958                 break;
959 #endif
960 
961         case SO_MAX_PACING_RATE:
962                 sk->sk_max_pacing_rate = val;
963                 sk->sk_pacing_rate = min(sk->sk_pacing_rate,
964                                          sk->sk_max_pacing_rate);
965                 break;
966 
967         default:
968                 ret = -ENOPROTOOPT;
969                 break;
970         }
971         release_sock(sk);
972         return ret;
973 }
974 EXPORT_SYMBOL(sock_setsockopt);
975 
976 
977 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
978                           struct ucred *ucred)
979 {
980         ucred->pid = pid_vnr(pid);
981         ucred->uid = ucred->gid = -1;
982         if (cred) {
983                 struct user_namespace *current_ns = current_user_ns();
984 
985                 ucred->uid = from_kuid_munged(current_ns, cred->euid);
986                 ucred->gid = from_kgid_munged(current_ns, cred->egid);
987         }
988 }
989 
990 int sock_getsockopt(struct socket *sock, int level, int optname,
991                     char __user *optval, int __user *optlen)
992 {
993         struct sock *sk = sock->sk;
994 
995         union {
996                 int val;
997                 struct linger ling;
998                 struct timeval tm;
999         } v;
1000 
1001         int lv = sizeof(int);
1002         int len;
1003 
1004         if (get_user(len, optlen))
1005                 return -EFAULT;
1006         if (len < 0)
1007                 return -EINVAL;
1008 
1009         memset(&v, 0, sizeof(v));
1010 
1011         switch (optname) {
1012         case SO_DEBUG:
1013                 v.val = sock_flag(sk, SOCK_DBG);
1014                 break;
1015 
1016         case SO_DONTROUTE:
1017                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
1018                 break;
1019 
1020         case SO_BROADCAST:
1021                 v.val = sock_flag(sk, SOCK_BROADCAST);
1022                 break;
1023 
1024         case SO_SNDBUF:
1025                 v.val = sk->sk_sndbuf;
1026                 break;
1027 
1028         case SO_RCVBUF:
1029                 v.val = sk->sk_rcvbuf;
1030                 break;
1031 
1032         case SO_REUSEADDR:
1033                 v.val = sk->sk_reuse;
1034                 break;
1035 
1036         case SO_REUSEPORT:
1037                 v.val = sk->sk_reuseport;
1038                 break;
1039 
1040         case SO_KEEPALIVE:
1041                 v.val = sock_flag(sk, SOCK_KEEPOPEN);
1042                 break;
1043 
1044         case SO_TYPE:
1045                 v.val = sk->sk_type;
1046                 break;
1047 
1048         case SO_PROTOCOL:
1049                 v.val = sk->sk_protocol;
1050                 break;
1051 
1052         case SO_DOMAIN:
1053                 v.val = sk->sk_family;
1054                 break;
1055 
1056         case SO_ERROR:
1057                 v.val = -sock_error(sk);
1058                 if (v.val == 0)
1059                         v.val = xchg(&sk->sk_err_soft, 0);
1060                 break;
1061 
1062         case SO_OOBINLINE:
1063                 v.val = sock_flag(sk, SOCK_URGINLINE);
1064                 break;
1065 
1066         case SO_NO_CHECK:
1067                 v.val = sk->sk_no_check;
1068                 break;
1069 
1070         case SO_PRIORITY:
1071                 v.val = sk->sk_priority;
1072                 break;
1073 
1074         case SO_LINGER:
1075                 lv              = sizeof(v.ling);
1076                 v.ling.l_onoff  = sock_flag(sk, SOCK_LINGER);
1077                 v.ling.l_linger = sk->sk_lingertime / HZ;
1078                 break;
1079 
1080         case SO_BSDCOMPAT:
1081                 sock_warn_obsolete_bsdism("getsockopt");
1082                 break;
1083 
1084         case SO_TIMESTAMP:
1085                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1086                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1087                 break;
1088 
1089         case SO_TIMESTAMPNS:
1090                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1091                 break;
1092 
1093         case SO_TIMESTAMPING:
1094                 v.val = 0;
1095                 if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
1096                         v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
1097                 if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
1098                         v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
1099                 if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
1100                         v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
1101                 if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
1102                         v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
1103                 if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
1104                         v.val |= SOF_TIMESTAMPING_SOFTWARE;
1105                 if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
1106                         v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
1107                 if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
1108                         v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
1109                 break;
1110 
1111         case SO_RCVTIMEO:
1112                 lv = sizeof(struct timeval);
1113                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1114                         v.tm.tv_sec = 0;
1115                         v.tm.tv_usec = 0;
1116                 } else {
1117                         v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1118                         v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1119                 }
1120                 break;
1121 
1122         case SO_SNDTIMEO:
1123                 lv = sizeof(struct timeval);
1124                 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1125                         v.tm.tv_sec = 0;
1126                         v.tm.tv_usec = 0;
1127                 } else {
1128                         v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1129                         v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1130                 }
1131                 break;
1132 
1133         case SO_RCVLOWAT:
1134                 v.val = sk->sk_rcvlowat;
1135                 break;
1136 
1137         case SO_SNDLOWAT:
1138                 v.val = 1;
1139                 break;
1140 
1141         case SO_PASSCRED:
1142                 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1143                 break;
1144 
1145         case SO_PEERCRED:
1146         {
1147                 struct ucred peercred;
1148                 if (len > sizeof(peercred))
1149                         len = sizeof(peercred);
1150                 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1151                 if (copy_to_user(optval, &peercred, len))
1152                         return -EFAULT;
1153                 goto lenout;
1154         }
1155 
1156         case SO_PEERNAME:
1157         {
1158                 char address[128];
1159 
1160                 if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1161                         return -ENOTCONN;
1162                 if (lv < len)
1163                         return -EINVAL;
1164                 if (copy_to_user(optval, address, len))
1165                         return -EFAULT;
1166                 goto lenout;
1167         }
1168 
1169         /* Dubious BSD thing... Probably nobody even uses it, but
1170          * the UNIX standard wants it for whatever reason... -DaveM
1171          */
1172         case SO_ACCEPTCONN:
1173                 v.val = sk->sk_state == TCP_LISTEN;
1174                 break;
1175 
1176         case SO_PASSSEC:
1177                 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1178                 break;
1179 
1180         case SO_PEERSEC:
1181                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1182 
1183         case SO_MARK:
1184                 v.val = sk->sk_mark;
1185                 break;
1186 
1187         case SO_RXQ_OVFL:
1188                 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1189                 break;
1190 
1191         case SO_WIFI_STATUS:
1192                 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1193                 break;
1194 
1195         case SO_PEEK_OFF:
1196                 if (!sock->ops->set_peek_off)
1197                         return -EOPNOTSUPP;
1198 
1199                 v.val = sk->sk_peek_off;
1200                 break;
1201         case SO_NOFCS:
1202                 v.val = sock_flag(sk, SOCK_NOFCS);
1203                 break;
1204 
1205         case SO_BINDTODEVICE:
1206                 return sock_getbindtodevice(sk, optval, optlen, len);
1207 
1208         case SO_GET_FILTER:
1209                 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1210                 if (len < 0)
1211                         return len;
1212 
1213                 goto lenout;
1214 
1215         case SO_LOCK_FILTER:
1216                 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1217                 break;
1218 
1219         case SO_BPF_EXTENSIONS:
1220                 v.val = bpf_tell_extensions();
1221                 break;
1222 
1223         case SO_SELECT_ERR_QUEUE:
1224                 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1225                 break;
1226 
1227 #ifdef CONFIG_NET_RX_BUSY_POLL
1228         case SO_BUSY_POLL:
1229                 v.val = sk->sk_ll_usec;
1230                 break;
1231 #endif
1232 
1233         case SO_MAX_PACING_RATE:
1234                 v.val = sk->sk_max_pacing_rate;
1235                 break;
1236 
1237         default:
1238                 return -ENOPROTOOPT;
1239         }
1240 
1241         if (len > lv)
1242                 len = lv;
1243         if (copy_to_user(optval, &v, len))
1244                 return -EFAULT;
1245 lenout:
1246         if (put_user(len, optlen))
1247                 return -EFAULT;
1248         return 0;
1249 }
1250 
1251 /*
1252  * Initialize an sk_lock.
1253  *
1254  * (We also register the sk_lock with the lock validator.)
1255  */
1256 static inline void sock_lock_init(struct sock *sk)
1257 {
1258         sock_lock_init_class_and_name(sk,
1259                         af_family_slock_key_strings[sk->sk_family],
1260                         af_family_slock_keys + sk->sk_family,
1261                         af_family_key_strings[sk->sk_family],
1262                         af_family_keys + sk->sk_family);
1263 }
1264 
1265 /*
1266  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1267  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1268  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1269  */
1270 static void sock_copy(struct sock *nsk, const struct sock *osk)
1271 {
1272 #ifdef CONFIG_SECURITY_NETWORK
1273         void *sptr = nsk->sk_security;
1274 #endif
1275         memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1276 
1277         memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1278                osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1279 
1280 #ifdef CONFIG_SECURITY_NETWORK
1281         nsk->sk_security = sptr;
1282         security_sk_clone(osk, nsk);
1283 #endif
1284 }
1285 
1286 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1287 {
1288         unsigned long nulls1, nulls2;
1289 
1290         nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1291         nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1292         if (nulls1 > nulls2)
1293                 swap(nulls1, nulls2);
1294 
1295         if (nulls1 != 0)
1296                 memset((char *)sk, 0, nulls1);
1297         memset((char *)sk + nulls1 + sizeof(void *), 0,
1298                nulls2 - nulls1 - sizeof(void *));
1299         memset((char *)sk + nulls2 + sizeof(void *), 0,
1300                size - nulls2 - sizeof(void *));
1301 }
1302 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1303 
1304 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1305                 int family)
1306 {
1307         struct sock *sk;
1308         struct kmem_cache *slab;
1309 
1310         slab = prot->slab;
1311         if (slab != NULL) {
1312                 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1313                 if (!sk)
1314                         return sk;
1315                 if (priority & __GFP_ZERO) {
1316                         if (prot->clear_sk)
1317                                 prot->clear_sk(sk, prot->obj_size);
1318                         else
1319                                 sk_prot_clear_nulls(sk, prot->obj_size);
1320                 }
1321         } else
1322                 sk = kmalloc(prot->obj_size, priority);
1323 
1324         if (sk != NULL) {
1325                 kmemcheck_annotate_bitfield(sk, flags);
1326 
1327                 if (security_sk_alloc(sk, family, priority))
1328                         goto out_free;
1329 
1330                 if (!try_module_get(prot->owner))
1331                         goto out_free_sec;
1332                 sk_tx_queue_clear(sk);
1333         }
1334 
1335         return sk;
1336 
1337 out_free_sec:
1338         security_sk_free(sk);
1339 out_free:
1340         if (slab != NULL)
1341                 kmem_cache_free(slab, sk);
1342         else
1343                 kfree(sk);
1344         return NULL;
1345 }
1346 
1347 static void sk_prot_free(struct proto *prot, struct sock *sk)
1348 {
1349         struct kmem_cache *slab;
1350         struct module *owner;
1351 
1352         owner = prot->owner;
1353         slab = prot->slab;
1354 
1355         security_sk_free(sk);
1356         if (slab != NULL)
1357                 kmem_cache_free(slab, sk);
1358         else
1359                 kfree(sk);
1360         module_put(owner);
1361 }
1362 
1363 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
1364 void sock_update_netprioidx(struct sock *sk)
1365 {
1366         if (in_interrupt())
1367                 return;
1368 
1369         sk->sk_cgrp_prioidx = task_netprioidx(current);
1370 }
1371 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1372 #endif
1373 
1374 /**
1375  *      sk_alloc - All socket objects are allocated here
1376  *      @net: the applicable net namespace
1377  *      @family: protocol family
1378  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1379  *      @prot: struct proto associated with this new sock instance
1380  */
1381 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1382                       struct proto *prot)
1383 {
1384         struct sock *sk;
1385 
1386         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1387         if (sk) {
1388                 sk->sk_family = family;
1389                 /*
1390                  * See comment in struct sock definition to understand
1391                  * why we need sk_prot_creator -acme
1392                  */
1393                 sk->sk_prot = sk->sk_prot_creator = prot;
1394                 sock_lock_init(sk);
1395                 sock_net_set(sk, get_net(net));
1396                 atomic_set(&sk->sk_wmem_alloc, 1);
1397 
1398                 sock_update_classid(sk);
1399                 sock_update_netprioidx(sk);
1400         }
1401 
1402         return sk;
1403 }
1404 EXPORT_SYMBOL(sk_alloc);
1405 
1406 static void __sk_free(struct sock *sk)
1407 {
1408         struct sk_filter *filter;
1409 
1410         if (sk->sk_destruct)
1411                 sk->sk_destruct(sk);
1412 
1413         filter = rcu_dereference_check(sk->sk_filter,
1414                                        atomic_read(&sk->sk_wmem_alloc) == 0);
1415         if (filter) {
1416                 sk_filter_uncharge(sk, filter);
1417                 RCU_INIT_POINTER(sk->sk_filter, NULL);
1418         }
1419 
1420         sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1421 
1422         if (atomic_read(&sk->sk_omem_alloc))
1423                 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1424                          __func__, atomic_read(&sk->sk_omem_alloc));
1425 
1426         if (sk->sk_peer_cred)
1427                 put_cred(sk->sk_peer_cred);
1428         put_pid(sk->sk_peer_pid);
1429         put_net(sock_net(sk));
1430         sk_prot_free(sk->sk_prot_creator, sk);
1431 }
1432 
1433 void sk_free(struct sock *sk)
1434 {
1435         /*
1436          * We subtract one from sk_wmem_alloc and can know if
1437          * some packets are still in some tx queue.
1438          * If not null, sock_wfree() will call __sk_free(sk) later
1439          */
1440         if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1441                 __sk_free(sk);
1442 }
1443 EXPORT_SYMBOL(sk_free);
1444 
1445 /*
1446  * Last sock_put should drop reference to sk->sk_net. It has already
1447  * been dropped in sk_change_net. Taking reference to stopping namespace
1448  * is not an option.
1449  * Take reference to a socket to remove it from hash _alive_ and after that
1450  * destroy it in the context of init_net.
1451  */
1452 void sk_release_kernel(struct sock *sk)
1453 {
1454         if (sk == NULL || sk->sk_socket == NULL)
1455                 return;
1456 
1457         sock_hold(sk);
1458         sock_release(sk->sk_socket);
1459         release_net(sock_net(sk));
1460         sock_net_set(sk, get_net(&init_net));
1461         sock_put(sk);
1462 }
1463 EXPORT_SYMBOL(sk_release_kernel);
1464 
1465 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1466 {
1467         if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1468                 sock_update_memcg(newsk);
1469 }
1470 
1471 /**
1472  *      sk_clone_lock - clone a socket, and lock its clone
1473  *      @sk: the socket to clone
1474  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1475  *
1476  *      Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1477  */
1478 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1479 {
1480         struct sock *newsk;
1481 
1482         newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1483         if (newsk != NULL) {
1484                 struct sk_filter *filter;
1485 
1486                 sock_copy(newsk, sk);
1487 
1488                 /* SANITY */
1489                 get_net(sock_net(newsk));
1490                 sk_node_init(&newsk->sk_node);
1491                 sock_lock_init(newsk);
1492                 bh_lock_sock(newsk);
1493                 newsk->sk_backlog.head  = newsk->sk_backlog.tail = NULL;
1494                 newsk->sk_backlog.len = 0;
1495 
1496                 atomic_set(&newsk->sk_rmem_alloc, 0);
1497                 /*
1498                  * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1499                  */
1500                 atomic_set(&newsk->sk_wmem_alloc, 1);
1501                 atomic_set(&newsk->sk_omem_alloc, 0);
1502                 skb_queue_head_init(&newsk->sk_receive_queue);
1503                 skb_queue_head_init(&newsk->sk_write_queue);
1504 #ifdef CONFIG_NET_DMA
1505                 skb_queue_head_init(&newsk->sk_async_wait_queue);
1506 #endif
1507 
1508                 spin_lock_init(&newsk->sk_dst_lock);
1509                 rwlock_init(&newsk->sk_callback_lock);
1510                 lockdep_set_class_and_name(&newsk->sk_callback_lock,
1511                                 af_callback_keys + newsk->sk_family,
1512                                 af_family_clock_key_strings[newsk->sk_family]);
1513 
1514                 newsk->sk_dst_cache     = NULL;
1515                 newsk->sk_wmem_queued   = 0;
1516                 newsk->sk_forward_alloc = 0;
1517                 newsk->sk_send_head     = NULL;
1518                 newsk->sk_userlocks     = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1519 
1520                 sock_reset_flag(newsk, SOCK_DONE);
1521                 skb_queue_head_init(&newsk->sk_error_queue);
1522 
1523                 filter = rcu_dereference_protected(newsk->sk_filter, 1);
1524                 if (filter != NULL)
1525                         sk_filter_charge(newsk, filter);
1526 
1527                 if (unlikely(xfrm_sk_clone_policy(newsk))) {
1528                         /* It is still raw copy of parent, so invalidate
1529                          * destructor and make plain sk_free() */
1530                         newsk->sk_destruct = NULL;
1531                         bh_unlock_sock(newsk);
1532                         sk_free(newsk);
1533                         newsk = NULL;
1534                         goto out;
1535                 }
1536 
1537                 newsk->sk_err      = 0;
1538                 newsk->sk_priority = 0;
1539                 /*
1540                  * Before updating sk_refcnt, we must commit prior changes to memory
1541                  * (Documentation/RCU/rculist_nulls.txt for details)
1542                  */
1543                 smp_wmb();
1544                 atomic_set(&newsk->sk_refcnt, 2);
1545 
1546                 /*
1547                  * Increment the counter in the same struct proto as the master
1548                  * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1549                  * is the same as sk->sk_prot->socks, as this field was copied
1550                  * with memcpy).
1551                  *
1552                  * This _changes_ the previous behaviour, where
1553                  * tcp_create_openreq_child always was incrementing the
1554                  * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1555                  * to be taken into account in all callers. -acme
1556                  */
1557                 sk_refcnt_debug_inc(newsk);
1558                 sk_set_socket(newsk, NULL);
1559                 newsk->sk_wq = NULL;
1560 
1561                 sk_update_clone(sk, newsk);
1562 
1563                 if (newsk->sk_prot->sockets_allocated)
1564                         sk_sockets_allocated_inc(newsk);
1565 
1566                 if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1567                         net_enable_timestamp();
1568         }
1569 out:
1570         return newsk;
1571 }
1572 EXPORT_SYMBOL_GPL(sk_clone_lock);
1573 
1574 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1575 {
1576         __sk_dst_set(sk, dst);
1577         sk->sk_route_caps = dst->dev->features;
1578         if (sk->sk_route_caps & NETIF_F_GSO)
1579                 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1580         sk->sk_route_caps &= ~sk->sk_route_nocaps;
1581         if (sk_can_gso(sk)) {
1582                 if (dst->header_len) {
1583                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1584                 } else {
1585                         sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1586                         sk->sk_gso_max_size = dst->dev->gso_max_size;
1587                         sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1588                 }
1589         }
1590 }
1591 EXPORT_SYMBOL_GPL(sk_setup_caps);
1592 
1593 /*
1594  *      Simple resource managers for sockets.
1595  */
1596 
1597 
1598 /*
1599  * Write buffer destructor automatically called from kfree_skb.
1600  */
1601 void sock_wfree(struct sk_buff *skb)
1602 {
1603         struct sock *sk = skb->sk;
1604         unsigned int len = skb->truesize;
1605 
1606         if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1607                 /*
1608                  * Keep a reference on sk_wmem_alloc, this will be released
1609                  * after sk_write_space() call
1610                  */
1611                 atomic_sub(len - 1, &sk->sk_wmem_alloc);
1612                 sk->sk_write_space(sk);
1613                 len = 1;
1614         }
1615         /*
1616          * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1617          * could not do because of in-flight packets
1618          */
1619         if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1620                 __sk_free(sk);
1621 }
1622 EXPORT_SYMBOL(sock_wfree);
1623 
1624 void skb_orphan_partial(struct sk_buff *skb)
1625 {
1626         /* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1627          * so we do not completely orphan skb, but transfert all
1628          * accounted bytes but one, to avoid unexpected reorders.
1629          */
1630         if (skb->destructor == sock_wfree
1631 #ifdef CONFIG_INET
1632             || skb->destructor == tcp_wfree
1633 #endif
1634                 ) {
1635                 atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1636                 skb->truesize = 1;
1637         } else {
1638                 skb_orphan(skb);
1639         }
1640 }
1641 EXPORT_SYMBOL(skb_orphan_partial);
1642 
1643 /*
1644  * Read buffer destructor automatically called from kfree_skb.
1645  */
1646 void sock_rfree(struct sk_buff *skb)
1647 {
1648         struct sock *sk = skb->sk;
1649         unsigned int len = skb->truesize;
1650 
1651         atomic_sub(len, &sk->sk_rmem_alloc);
1652         sk_mem_uncharge(sk, len);
1653 }
1654 EXPORT_SYMBOL(sock_rfree);
1655 
1656 void sock_edemux(struct sk_buff *skb)
1657 {
1658         struct sock *sk = skb->sk;
1659 
1660 #ifdef CONFIG_INET
1661         if (sk->sk_state == TCP_TIME_WAIT)
1662                 inet_twsk_put(inet_twsk(sk));
1663         else
1664 #endif
1665                 sock_put(sk);
1666 }
1667 EXPORT_SYMBOL(sock_edemux);
1668 
1669 kuid_t sock_i_uid(struct sock *sk)
1670 {
1671         kuid_t uid;
1672 
1673         read_lock_bh(&sk->sk_callback_lock);
1674         uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1675         read_unlock_bh(&sk->sk_callback_lock);
1676         return uid;
1677 }
1678 EXPORT_SYMBOL(sock_i_uid);
1679 
1680 unsigned long sock_i_ino(struct sock *sk)
1681 {
1682         unsigned long ino;
1683 
1684         read_lock_bh(&sk->sk_callback_lock);
1685         ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1686         read_unlock_bh(&sk->sk_callback_lock);
1687         return ino;
1688 }
1689 EXPORT_SYMBOL(sock_i_ino);
1690 
1691 /*
1692  * Allocate a skb from the socket's send buffer.
1693  */
1694 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1695                              gfp_t priority)
1696 {
1697         if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1698                 struct sk_buff *skb = alloc_skb(size, priority);
1699                 if (skb) {
1700                         skb_set_owner_w(skb, sk);
1701                         return skb;
1702                 }
1703         }
1704         return NULL;
1705 }
1706 EXPORT_SYMBOL(sock_wmalloc);
1707 
1708 /*
1709  * Allocate a memory block from the socket's option memory buffer.
1710  */
1711 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1712 {
1713         if ((unsigned int)size <= sysctl_optmem_max &&
1714             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1715                 void *mem;
1716                 /* First do the add, to avoid the race if kmalloc
1717                  * might sleep.
1718                  */
1719                 atomic_add(size, &sk->sk_omem_alloc);
1720                 mem = kmalloc(size, priority);
1721                 if (mem)
1722                         return mem;
1723                 atomic_sub(size, &sk->sk_omem_alloc);
1724         }
1725         return NULL;
1726 }
1727 EXPORT_SYMBOL(sock_kmalloc);
1728 
1729 /*
1730  * Free an option memory block.
1731  */
1732 void sock_kfree_s(struct sock *sk, void *mem, int size)
1733 {
1734         kfree(mem);
1735         atomic_sub(size, &sk->sk_omem_alloc);
1736 }
1737 EXPORT_SYMBOL(sock_kfree_s);
1738 
1739 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1740    I think, these locks should be removed for datagram sockets.
1741  */
1742 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1743 {
1744         DEFINE_WAIT(wait);
1745 
1746         clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1747         for (;;) {
1748                 if (!timeo)
1749                         break;
1750                 if (signal_pending(current))
1751                         break;
1752                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1753                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1754                 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1755                         break;
1756                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1757                         break;
1758                 if (sk->sk_err)
1759                         break;
1760                 timeo = schedule_timeout(timeo);
1761         }
1762         finish_wait(sk_sleep(sk), &wait);
1763         return timeo;
1764 }
1765 
1766 
1767 /*
1768  *      Generic send/receive buffer handlers
1769  */
1770 
1771 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1772                                      unsigned long data_len, int noblock,
1773                                      int *errcode, int max_page_order)
1774 {
1775         struct sk_buff *skb = NULL;
1776         unsigned long chunk;
1777         gfp_t gfp_mask;
1778         long timeo;
1779         int err;
1780         int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1781         struct page *page;
1782         int i;
1783 
1784         err = -EMSGSIZE;
1785         if (npages > MAX_SKB_FRAGS)
1786                 goto failure;
1787 
1788         timeo = sock_sndtimeo(sk, noblock);
1789         while (!skb) {
1790                 err = sock_error(sk);
1791                 if (err != 0)
1792                         goto failure;
1793 
1794                 err = -EPIPE;
1795                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1796                         goto failure;
1797 
1798                 if (atomic_read(&sk->sk_wmem_alloc) >= sk->sk_sndbuf) {
1799                         set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1800                         set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1801                         err = -EAGAIN;
1802                         if (!timeo)
1803                                 goto failure;
1804                         if (signal_pending(current))
1805                                 goto interrupted;
1806                         timeo = sock_wait_for_wmem(sk, timeo);
1807                         continue;
1808                 }
1809 
1810                 err = -ENOBUFS;
1811                 gfp_mask = sk->sk_allocation;
1812                 if (gfp_mask & __GFP_WAIT)
1813                         gfp_mask |= __GFP_REPEAT;
1814 
1815                 skb = alloc_skb(header_len, gfp_mask);
1816                 if (!skb)
1817                         goto failure;
1818 
1819                 skb->truesize += data_len;
1820 
1821                 for (i = 0; npages > 0; i++) {
1822                         int order = max_page_order;
1823 
1824                         while (order) {
1825                                 if (npages >= 1 << order) {
1826                                         page = alloc_pages(sk->sk_allocation |
1827                                                            __GFP_COMP |
1828                                                            __GFP_NOWARN |
1829                                                            __GFP_NORETRY,
1830                                                            order);
1831                                         if (page)
1832                                                 goto fill_page;
1833                                 }
1834                                 order--;
1835                         }
1836                         page = alloc_page(sk->sk_allocation);
1837                         if (!page)
1838                                 goto failure;
1839 fill_page:
1840                         chunk = min_t(unsigned long, data_len,
1841                                       PAGE_SIZE << order);
1842                         skb_fill_page_desc(skb, i, page, 0, chunk);
1843                         data_len -= chunk;
1844                         npages -= 1 << order;
1845                 }
1846         }
1847 
1848         skb_set_owner_w(skb, sk);
1849         return skb;
1850 
1851 interrupted:
1852         err = sock_intr_errno(timeo);
1853 failure:
1854         kfree_skb(skb);
1855         *errcode = err;
1856         return NULL;
1857 }
1858 EXPORT_SYMBOL(sock_alloc_send_pskb);
1859 
1860 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1861                                     int noblock, int *errcode)
1862 {
1863         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1864 }
1865 EXPORT_SYMBOL(sock_alloc_send_skb);
1866 
1867 /* On 32bit arches, an skb frag is limited to 2^15 */
1868 #define SKB_FRAG_PAGE_ORDER     get_order(32768)
1869 
1870 /**
1871  * skb_page_frag_refill - check that a page_frag contains enough room
1872  * @sz: minimum size of the fragment we want to get
1873  * @pfrag: pointer to page_frag
1874  * @prio: priority for memory allocation
1875  *
1876  * Note: While this allocator tries to use high order pages, there is
1877  * no guarantee that allocations succeed. Therefore, @sz MUST be
1878  * less or equal than PAGE_SIZE.
1879  */
1880 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t prio)
1881 {
1882         int order;
1883 
1884         if (pfrag->page) {
1885                 if (atomic_read(&pfrag->page->_count) == 1) {
1886                         pfrag->offset = 0;
1887                         return true;
1888                 }
1889                 if (pfrag->offset + sz <= pfrag->size)
1890                         return true;
1891                 put_page(pfrag->page);
1892         }
1893 
1894         order = SKB_FRAG_PAGE_ORDER;
1895         do {
1896                 gfp_t gfp = prio;
1897 
1898                 if (order)
1899                         gfp |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY;
1900                 pfrag->page = alloc_pages(gfp, order);
1901                 if (likely(pfrag->page)) {
1902                         pfrag->offset = 0;
1903                         pfrag->size = PAGE_SIZE << order;
1904                         return true;
1905                 }
1906         } while (--order >= 0);
1907 
1908         return false;
1909 }
1910 EXPORT_SYMBOL(skb_page_frag_refill);
1911 
1912 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1913 {
1914         if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1915                 return true;
1916 
1917         sk_enter_memory_pressure(sk);
1918         sk_stream_moderate_sndbuf(sk);
1919         return false;
1920 }
1921 EXPORT_SYMBOL(sk_page_frag_refill);
1922 
1923 static void __lock_sock(struct sock *sk)
1924         __releases(&sk->sk_lock.slock)
1925         __acquires(&sk->sk_lock.slock)
1926 {
1927         DEFINE_WAIT(wait);
1928 
1929         for (;;) {
1930                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1931                                         TASK_UNINTERRUPTIBLE);
1932                 spin_unlock_bh(&sk->sk_lock.slock);
1933                 schedule();
1934                 spin_lock_bh(&sk->sk_lock.slock);
1935                 if (!sock_owned_by_user(sk))
1936                         break;
1937         }
1938         finish_wait(&sk->sk_lock.wq, &wait);
1939 }
1940 
1941 static void __release_sock(struct sock *sk)
1942         __releases(&sk->sk_lock.slock)
1943         __acquires(&sk->sk_lock.slock)
1944 {
1945         struct sk_buff *skb = sk->sk_backlog.head;
1946 
1947         do {
1948                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1949                 bh_unlock_sock(sk);
1950 
1951                 do {
1952                         struct sk_buff *next = skb->next;
1953 
1954                         prefetch(next);
1955                         WARN_ON_ONCE(skb_dst_is_noref(skb));
1956                         skb->next = NULL;
1957                         sk_backlog_rcv(sk, skb);
1958 
1959                         /*
1960                          * We are in process context here with softirqs
1961                          * disabled, use cond_resched_softirq() to preempt.
1962                          * This is safe to do because we've taken the backlog
1963                          * queue private:
1964                          */
1965                         cond_resched_softirq();
1966 
1967                         skb = next;
1968                 } while (skb != NULL);
1969 
1970                 bh_lock_sock(sk);
1971         } while ((skb = sk->sk_backlog.head) != NULL);
1972 
1973         /*
1974          * Doing the zeroing here guarantee we can not loop forever
1975          * while a wild producer attempts to flood us.
1976          */
1977         sk->sk_backlog.len = 0;
1978 }
1979 
1980 /**
1981  * sk_wait_data - wait for data to arrive at sk_receive_queue
1982  * @sk:    sock to wait on
1983  * @timeo: for how long
1984  *
1985  * Now socket state including sk->sk_err is changed only under lock,
1986  * hence we may omit checks after joining wait queue.
1987  * We check receive queue before schedule() only as optimization;
1988  * it is very likely that release_sock() added new data.
1989  */
1990 int sk_wait_data(struct sock *sk, long *timeo)
1991 {
1992         int rc;
1993         DEFINE_WAIT(wait);
1994 
1995         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1996         set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1997         rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1998         clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1999         finish_wait(sk_sleep(sk), &wait);
2000         return rc;
2001 }
2002 EXPORT_SYMBOL(sk_wait_data);
2003 
2004 /**
2005  *      __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2006  *      @sk: socket
2007  *      @size: memory size to allocate
2008  *      @kind: allocation type
2009  *
2010  *      If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2011  *      rmem allocation. This function assumes that protocols which have
2012  *      memory_pressure use sk_wmem_queued as write buffer accounting.
2013  */
2014 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2015 {
2016         struct proto *prot = sk->sk_prot;
2017         int amt = sk_mem_pages(size);
2018         long allocated;
2019         int parent_status = UNDER_LIMIT;
2020 
2021         sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
2022 
2023         allocated = sk_memory_allocated_add(sk, amt, &parent_status);
2024 
2025         /* Under limit. */
2026         if (parent_status == UNDER_LIMIT &&
2027                         allocated <= sk_prot_mem_limits(sk, 0)) {
2028                 sk_leave_memory_pressure(sk);
2029                 return 1;
2030         }
2031 
2032         /* Under pressure. (we or our parents) */
2033         if ((parent_status > SOFT_LIMIT) ||
2034                         allocated > sk_prot_mem_limits(sk, 1))
2035                 sk_enter_memory_pressure(sk);
2036 
2037         /* Over hard limit (we or our parents) */
2038         if ((parent_status == OVER_LIMIT) ||
2039                         (allocated > sk_prot_mem_limits(sk, 2)))
2040                 goto suppress_allocation;
2041 
2042         /* guarantee minimum buffer size under pressure */
2043         if (kind == SK_MEM_RECV) {
2044                 if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2045                         return 1;
2046 
2047         } else { /* SK_MEM_SEND */
2048                 if (sk->sk_type == SOCK_STREAM) {
2049                         if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2050                                 return 1;
2051                 } else if (atomic_read(&sk->sk_wmem_alloc) <
2052                            prot->sysctl_wmem[0])
2053                                 return 1;
2054         }
2055 
2056         if (sk_has_memory_pressure(sk)) {
2057                 int alloc;
2058 
2059                 if (!sk_under_memory_pressure(sk))
2060                         return 1;
2061                 alloc = sk_sockets_allocated_read_positive(sk);
2062                 if (sk_prot_mem_limits(sk, 2) > alloc *
2063                     sk_mem_pages(sk->sk_wmem_queued +
2064                                  atomic_read(&sk->sk_rmem_alloc) +
2065                                  sk->sk_forward_alloc))
2066                         return 1;
2067         }
2068 
2069 suppress_allocation:
2070 
2071         if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2072                 sk_stream_moderate_sndbuf(sk);
2073 
2074                 /* Fail only if socket is _under_ its sndbuf.
2075                  * In this case we cannot block, so that we have to fail.
2076                  */
2077                 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2078                         return 1;
2079         }
2080 
2081         trace_sock_exceed_buf_limit(sk, prot, allocated);
2082 
2083         /* Alas. Undo changes. */
2084         sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2085 
2086         sk_memory_allocated_sub(sk, amt);
2087 
2088         return 0;
2089 }
2090 EXPORT_SYMBOL(__sk_mem_schedule);
2091 
2092 /**
2093  *      __sk_reclaim - reclaim memory_allocated
2094  *      @sk: socket
2095  */
2096 void __sk_mem_reclaim(struct sock *sk)
2097 {
2098         sk_memory_allocated_sub(sk,
2099                                 sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
2100         sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
2101 
2102         if (sk_under_memory_pressure(sk) &&
2103             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2104                 sk_leave_memory_pressure(sk);
2105 }
2106 EXPORT_SYMBOL(__sk_mem_reclaim);
2107 
2108 
2109 /*
2110  * Set of default routines for initialising struct proto_ops when
2111  * the protocol does not support a particular function. In certain
2112  * cases where it makes no sense for a protocol to have a "do nothing"
2113  * function, some default processing is provided.
2114  */
2115 
2116 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2117 {
2118         return -EOPNOTSUPP;
2119 }
2120 EXPORT_SYMBOL(sock_no_bind);
2121 
2122 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2123                     int len, int flags)
2124 {
2125         return -EOPNOTSUPP;
2126 }
2127 EXPORT_SYMBOL(sock_no_connect);
2128 
2129 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2130 {
2131         return -EOPNOTSUPP;
2132 }
2133 EXPORT_SYMBOL(sock_no_socketpair);
2134 
2135 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2136 {
2137         return -EOPNOTSUPP;
2138 }
2139 EXPORT_SYMBOL(sock_no_accept);
2140 
2141 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2142                     int *len, int peer)
2143 {
2144         return -EOPNOTSUPP;
2145 }
2146 EXPORT_SYMBOL(sock_no_getname);
2147 
2148 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2149 {
2150         return 0;
2151 }
2152 EXPORT_SYMBOL(sock_no_poll);
2153 
2154 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2155 {
2156         return -EOPNOTSUPP;
2157 }
2158 EXPORT_SYMBOL(sock_no_ioctl);
2159 
2160 int sock_no_listen(struct socket *sock, int backlog)
2161 {
2162         return -EOPNOTSUPP;
2163 }
2164 EXPORT_SYMBOL(sock_no_listen);
2165 
2166 int sock_no_shutdown(struct socket *sock, int how)
2167 {
2168         return -EOPNOTSUPP;
2169 }
2170 EXPORT_SYMBOL(sock_no_shutdown);
2171 
2172 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2173                     char __user *optval, unsigned int optlen)
2174 {
2175         return -EOPNOTSUPP;
2176 }
2177 EXPORT_SYMBOL(sock_no_setsockopt);
2178 
2179 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2180                     char __user *optval, int __user *optlen)
2181 {
2182         return -EOPNOTSUPP;
2183 }
2184 EXPORT_SYMBOL(sock_no_getsockopt);
2185 
2186 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2187                     size_t len)
2188 {
2189         return -EOPNOTSUPP;
2190 }
2191 EXPORT_SYMBOL(sock_no_sendmsg);
2192 
2193 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2194                     size_t len, int flags)
2195 {
2196         return -EOPNOTSUPP;
2197 }
2198 EXPORT_SYMBOL(sock_no_recvmsg);
2199 
2200 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2201 {
2202         /* Mirror missing mmap method error code */
2203         return -ENODEV;
2204 }
2205 EXPORT_SYMBOL(sock_no_mmap);
2206 
2207 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2208 {
2209         ssize_t res;
2210         struct msghdr msg = {.msg_flags = flags};
2211         struct kvec iov;
2212         char *kaddr = kmap(page);
2213         iov.iov_base = kaddr + offset;
2214         iov.iov_len = size;
2215         res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2216         kunmap(page);
2217         return res;
2218 }
2219 EXPORT_SYMBOL(sock_no_sendpage);
2220 
2221 /*
2222  *      Default Socket Callbacks
2223  */
2224 
2225 static void sock_def_wakeup(struct sock *sk)
2226 {
2227         struct socket_wq *wq;
2228 
2229         rcu_read_lock();
2230         wq = rcu_dereference(sk->sk_wq);
2231         if (wq_has_sleeper(wq))
2232                 wake_up_interruptible_all(&wq->wait);
2233         rcu_read_unlock();
2234 }
2235 
2236 static void sock_def_error_report(struct sock *sk)
2237 {
2238         struct socket_wq *wq;
2239 
2240         rcu_read_lock();
2241         wq = rcu_dereference(sk->sk_wq);
2242         if (wq_has_sleeper(wq))
2243                 wake_up_interruptible_poll(&wq->wait, POLLERR);
2244         sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2245         rcu_read_unlock();
2246 }
2247 
2248 static void sock_def_readable(struct sock *sk)
2249 {
2250         struct socket_wq *wq;
2251 
2252         rcu_read_lock();
2253         wq = rcu_dereference(sk->sk_wq);
2254         if (wq_has_sleeper(wq))
2255                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2256                                                 POLLRDNORM | POLLRDBAND);
2257         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2258         rcu_read_unlock();
2259 }
2260 
2261 static void sock_def_write_space(struct sock *sk)
2262 {
2263         struct socket_wq *wq;
2264 
2265         rcu_read_lock();
2266 
2267         /* Do not wake up a writer until he can make "significant"
2268          * progress.  --DaveM
2269          */
2270         if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2271                 wq = rcu_dereference(sk->sk_wq);
2272                 if (wq_has_sleeper(wq))
2273                         wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2274                                                 POLLWRNORM | POLLWRBAND);
2275 
2276                 /* Should agree with poll, otherwise some programs break */
2277                 if (sock_writeable(sk))
2278                         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2279         }
2280 
2281         rcu_read_unlock();
2282 }
2283 
2284 static void sock_def_destruct(struct sock *sk)
2285 {
2286         kfree(sk->sk_protinfo);
2287 }
2288 
2289 void sk_send_sigurg(struct sock *sk)
2290 {
2291         if (sk->sk_socket && sk->sk_socket->file)
2292                 if (send_sigurg(&sk->sk_socket->file->f_owner))
2293                         sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2294 }
2295 EXPORT_SYMBOL(sk_send_sigurg);
2296 
2297 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2298                     unsigned long expires)
2299 {
2300         if (!mod_timer(timer, expires))
2301                 sock_hold(sk);
2302 }
2303 EXPORT_SYMBOL(sk_reset_timer);
2304 
2305 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2306 {
2307         if (del_timer(timer))
2308                 __sock_put(sk);
2309 }
2310 EXPORT_SYMBOL(sk_stop_timer);
2311 
2312 void sock_init_data(struct socket *sock, struct sock *sk)
2313 {
2314         skb_queue_head_init(&sk->sk_receive_queue);
2315         skb_queue_head_init(&sk->sk_write_queue);
2316         skb_queue_head_init(&sk->sk_error_queue);
2317 #ifdef CONFIG_NET_DMA
2318         skb_queue_head_init(&sk->sk_async_wait_queue);
2319 #endif
2320 
2321         sk->sk_send_head        =       NULL;
2322 
2323         init_timer(&sk->sk_timer);
2324 
2325         sk->sk_allocation       =       GFP_KERNEL;
2326         sk->sk_rcvbuf           =       sysctl_rmem_default;
2327         sk->sk_sndbuf           =       sysctl_wmem_default;
2328         sk->sk_state            =       TCP_CLOSE;
2329         sk_set_socket(sk, sock);
2330 
2331         sock_set_flag(sk, SOCK_ZAPPED);
2332 
2333         if (sock) {
2334                 sk->sk_type     =       sock->type;
2335                 sk->sk_wq       =       sock->wq;
2336                 sock->sk        =       sk;
2337         } else
2338                 sk->sk_wq       =       NULL;
2339 
2340         spin_lock_init(&sk->sk_dst_lock);
2341         rwlock_init(&sk->sk_callback_lock);
2342         lockdep_set_class_and_name(&sk->sk_callback_lock,
2343                         af_callback_keys + sk->sk_family,
2344                         af_family_clock_key_strings[sk->sk_family]);
2345 
2346         sk->sk_state_change     =       sock_def_wakeup;
2347         sk->sk_data_ready       =       sock_def_readable;
2348         sk->sk_write_space      =       sock_def_write_space;
2349         sk->sk_error_report     =       sock_def_error_report;
2350         sk->sk_destruct         =       sock_def_destruct;
2351 
2352         sk->sk_frag.page        =       NULL;
2353         sk->sk_frag.offset      =       0;
2354         sk->sk_peek_off         =       -1;
2355 
2356         sk->sk_peer_pid         =       NULL;
2357         sk->sk_peer_cred        =       NULL;
2358         sk->sk_write_pending    =       0;
2359         sk->sk_rcvlowat         =       1;
2360         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
2361         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
2362 
2363         sk->sk_stamp = ktime_set(-1L, 0);
2364 
2365 #ifdef CONFIG_NET_RX_BUSY_POLL
2366         sk->sk_napi_id          =       0;
2367         sk->sk_ll_usec          =       sysctl_net_busy_read;
2368 #endif
2369 
2370         sk->sk_max_pacing_rate = ~0U;
2371         sk->sk_pacing_rate = ~0U;
2372         /*
2373          * Before updating sk_refcnt, we must commit prior changes to memory
2374          * (Documentation/RCU/rculist_nulls.txt for details)
2375          */
2376         smp_wmb();
2377         atomic_set(&sk->sk_refcnt, 1);
2378         atomic_set(&sk->sk_drops, 0);
2379 }
2380 EXPORT_SYMBOL(sock_init_data);
2381 
2382 void lock_sock_nested(struct sock *sk, int subclass)
2383 {
2384         might_sleep();
2385         spin_lock_bh(&sk->sk_lock.slock);
2386         if (sk->sk_lock.owned)
2387                 __lock_sock(sk);
2388         sk->sk_lock.owned = 1;
2389         spin_unlock(&sk->sk_lock.slock);
2390         /*
2391          * The sk_lock has mutex_lock() semantics here:
2392          */
2393         mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2394         local_bh_enable();
2395 }
2396 EXPORT_SYMBOL(lock_sock_nested);
2397 
2398 void release_sock(struct sock *sk)
2399 {
2400         /*
2401          * The sk_lock has mutex_unlock() semantics:
2402          */
2403         mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2404 
2405         spin_lock_bh(&sk->sk_lock.slock);
2406         if (sk->sk_backlog.tail)
2407                 __release_sock(sk);
2408 
2409         /* Warning : release_cb() might need to release sk ownership,
2410          * ie call sock_release_ownership(sk) before us.
2411          */
2412         if (sk->sk_prot->release_cb)
2413                 sk->sk_prot->release_cb(sk);
2414 
2415         sock_release_ownership(sk);
2416         if (waitqueue_active(&sk->sk_lock.wq))
2417                 wake_up(&sk->sk_lock.wq);
2418         spin_unlock_bh(&sk->sk_lock.slock);
2419 }
2420 EXPORT_SYMBOL(release_sock);
2421 
2422 /**
2423  * lock_sock_fast - fast version of lock_sock
2424  * @sk: socket
2425  *
2426  * This version should be used for very small section, where process wont block
2427  * return false if fast path is taken
2428  *   sk_lock.slock locked, owned = 0, BH disabled
2429  * return true if slow path is taken
2430  *   sk_lock.slock unlocked, owned = 1, BH enabled
2431  */
2432 bool lock_sock_fast(struct sock *sk)
2433 {
2434         might_sleep();
2435         spin_lock_bh(&sk->sk_lock.slock);
2436 
2437         if (!sk->sk_lock.owned)
2438                 /*
2439                  * Note : We must disable BH
2440                  */
2441                 return false;
2442 
2443         __lock_sock(sk);
2444         sk->sk_lock.owned = 1;
2445         spin_unlock(&sk->sk_lock.slock);
2446         /*
2447          * The sk_lock has mutex_lock() semantics here:
2448          */
2449         mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2450         local_bh_enable();
2451         return true;
2452 }
2453 EXPORT_SYMBOL(lock_sock_fast);
2454 
2455 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2456 {
2457         struct timeval tv;
2458         if (!sock_flag(sk, SOCK_TIMESTAMP))
2459                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2460         tv = ktime_to_timeval(sk->sk_stamp);
2461         if (tv.tv_sec == -1)
2462                 return -ENOENT;
2463         if (tv.tv_sec == 0) {
2464                 sk->sk_stamp = ktime_get_real();
2465                 tv = ktime_to_timeval(sk->sk_stamp);
2466         }
2467         return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2468 }
2469 EXPORT_SYMBOL(sock_get_timestamp);
2470 
2471 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2472 {
2473         struct timespec ts;
2474         if (!sock_flag(sk, SOCK_TIMESTAMP))
2475                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2476         ts = ktime_to_timespec(sk->sk_stamp);
2477         if (ts.tv_sec == -1)
2478                 return -ENOENT;
2479         if (ts.tv_sec == 0) {
2480                 sk->sk_stamp = ktime_get_real();
2481                 ts = ktime_to_timespec(sk->sk_stamp);
2482         }
2483         return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2484 }
2485 EXPORT_SYMBOL(sock_get_timestampns);
2486 
2487 void sock_enable_timestamp(struct sock *sk, int flag)
2488 {
2489         if (!sock_flag(sk, flag)) {
2490                 unsigned long previous_flags = sk->sk_flags;
2491 
2492                 sock_set_flag(sk, flag);
2493                 /*
2494                  * we just set one of the two flags which require net
2495                  * time stamping, but time stamping might have been on
2496                  * already because of the other one
2497                  */
2498                 if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2499                         net_enable_timestamp();
2500         }
2501 }
2502 
2503 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2504                        int level, int type)
2505 {
2506         struct sock_exterr_skb *serr;
2507         struct sk_buff *skb, *skb2;
2508         int copied, err;
2509 
2510         err = -EAGAIN;
2511         skb = skb_dequeue(&sk->sk_error_queue);
2512         if (skb == NULL)
2513                 goto out;
2514 
2515         copied = skb->len;
2516         if (copied > len) {
2517                 msg->msg_flags |= MSG_TRUNC;
2518                 copied = len;
2519         }
2520         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2521         if (err)
2522                 goto out_free_skb;
2523 
2524         sock_recv_timestamp(msg, sk, skb);
2525 
2526         serr = SKB_EXT_ERR(skb);
2527         put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2528 
2529         msg->msg_flags |= MSG_ERRQUEUE;
2530         err = copied;
2531 
2532         /* Reset and regenerate socket error */
2533         spin_lock_bh(&sk->sk_error_queue.lock);
2534         sk->sk_err = 0;
2535         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2536                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2537                 spin_unlock_bh(&sk->sk_error_queue.lock);
2538                 sk->sk_error_report(sk);
2539         } else
2540                 spin_unlock_bh(&sk->sk_error_queue.lock);
2541 
2542 out_free_skb:
2543         kfree_skb(skb);
2544 out:
2545         return err;
2546 }
2547 EXPORT_SYMBOL(sock_recv_errqueue);
2548 
2549 /*
2550  *      Get a socket option on an socket.
2551  *
2552  *      FIX: POSIX 1003.1g is very ambiguous here. It states that
2553  *      asynchronous errors should be reported by getsockopt. We assume
2554  *      this means if you specify SO_ERROR (otherwise whats the point of it).
2555  */
2556 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2557                            char __user *optval, int __user *optlen)
2558 {
2559         struct sock *sk = sock->sk;
2560 
2561         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2562 }
2563 EXPORT_SYMBOL(sock_common_getsockopt);
2564 
2565 #ifdef CONFIG_COMPAT
2566 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2567                                   char __user *optval, int __user *optlen)
2568 {
2569         struct sock *sk = sock->sk;
2570 
2571         if (sk->sk_prot->compat_getsockopt != NULL)
2572                 return sk->sk_prot->compat_getsockopt(sk, level, optname,
2573                                                       optval, optlen);
2574         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2575 }
2576 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2577 #endif
2578 
2579 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2580                         struct msghdr *msg, size_t size, int flags)
2581 {
2582         struct sock *sk = sock->sk;
2583         int addr_len = 0;
2584         int err;
2585 
2586         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2587                                    flags & ~MSG_DONTWAIT, &addr_len);
2588         if (err >= 0)
2589                 msg->msg_namelen = addr_len;
2590         return err;
2591 }
2592 EXPORT_SYMBOL(sock_common_recvmsg);
2593 
2594 /*
2595  *      Set socket options on an inet socket.
2596  */
2597 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2598                            char __user *optval, unsigned int optlen)
2599 {
2600         struct sock *sk = sock->sk;
2601 
2602         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2603 }
2604 EXPORT_SYMBOL(sock_common_setsockopt);
2605 
2606 #ifdef CONFIG_COMPAT
2607 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2608                                   char __user *optval, unsigned int optlen)
2609 {
2610         struct sock *sk = sock->sk;
2611 
2612         if (sk->sk_prot->compat_setsockopt != NULL)
2613                 return sk->sk_prot->compat_setsockopt(sk, level, optname,
2614                                                       optval, optlen);
2615         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2616 }
2617 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2618 #endif
2619 
2620 void sk_common_release(struct sock *sk)
2621 {
2622         if (sk->sk_prot->destroy)
2623                 sk->sk_prot->destroy(sk);
2624 
2625         /*
2626          * Observation: when sock_common_release is called, processes have
2627          * no access to socket. But net still has.
2628          * Step one, detach it from networking:
2629          *
2630          * A. Remove from hash tables.
2631          */
2632 
2633         sk->sk_prot->unhash(sk);
2634 
2635         /*
2636          * In this point socket cannot receive new packets, but it is possible
2637          * that some packets are in flight because some CPU runs receiver and
2638          * did hash table lookup before we unhashed socket. They will achieve
2639          * receive queue and will be purged by socket destructor.
2640          *
2641          * Also we still have packets pending on receive queue and probably,
2642          * our own packets waiting in device queues. sock_destroy will drain
2643          * receive queue, but transmitted packets will delay socket destruction
2644          * until the last reference will be released.
2645          */
2646 
2647         sock_orphan(sk);
2648 
2649         xfrm_sk_free_policy(sk);
2650 
2651         sk_refcnt_debug_release(sk);
2652 
2653         if (sk->sk_frag.page) {
2654                 put_page(sk->sk_frag.page);
2655                 sk->sk_frag.page = NULL;
2656         }
2657 
2658         sock_put(sk);
2659 }
2660 EXPORT_SYMBOL(sk_common_release);
2661 
2662 #ifdef CONFIG_PROC_FS
2663 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
2664 struct prot_inuse {
2665         int val[PROTO_INUSE_NR];
2666 };
2667 
2668 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2669 
2670 #ifdef CONFIG_NET_NS
2671 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2672 {
2673         __this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2674 }
2675 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2676 
2677 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2678 {
2679         int cpu, idx = prot->inuse_idx;
2680         int res = 0;
2681 
2682         for_each_possible_cpu(cpu)
2683                 res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2684 
2685         return res >= 0 ? res : 0;
2686 }
2687 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2688 
2689 static int __net_init sock_inuse_init_net(struct net *net)
2690 {
2691         net->core.inuse = alloc_percpu(struct prot_inuse);
2692         return net->core.inuse ? 0 : -ENOMEM;
2693 }
2694 
2695 static void __net_exit sock_inuse_exit_net(struct net *net)
2696 {
2697         free_percpu(net->core.inuse);
2698 }
2699 
2700 static struct pernet_operations net_inuse_ops = {
2701         .init = sock_inuse_init_net,
2702         .exit = sock_inuse_exit_net,
2703 };
2704 
2705 static __init int net_inuse_init(void)
2706 {
2707         if (register_pernet_subsys(&net_inuse_ops))
2708                 panic("Cannot initialize net inuse counters");
2709 
2710         return 0;
2711 }
2712 
2713 core_initcall(net_inuse_init);
2714 #else
2715 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2716 
2717 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2718 {
2719         __this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2720 }
2721 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2722 
2723 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2724 {
2725         int cpu, idx = prot->inuse_idx;
2726         int res = 0;
2727 
2728         for_each_possible_cpu(cpu)
2729                 res += per_cpu(prot_inuse, cpu).val[idx];
2730 
2731         return res >= 0 ? res : 0;
2732 }
2733 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2734 #endif
2735 
2736 static void assign_proto_idx(struct proto *prot)
2737 {
2738         prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2739 
2740         if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2741                 pr_err("PROTO_INUSE_NR exhausted\n");
2742                 return;
2743         }
2744 
2745         set_bit(prot->inuse_idx, proto_inuse_idx);
2746 }
2747 
2748 static void release_proto_idx(struct proto *prot)
2749 {
2750         if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2751                 clear_bit(prot->inuse_idx, proto_inuse_idx);
2752 }
2753 #else
2754 static inline void assign_proto_idx(struct proto *prot)
2755 {
2756 }
2757 
2758 static inline void release_proto_idx(struct proto *prot)
2759 {
2760 }
2761 #endif
2762 
2763 int proto_register(struct proto *prot, int alloc_slab)
2764 {
2765         if (alloc_slab) {
2766                 prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2767                                         SLAB_HWCACHE_ALIGN | prot->slab_flags,
2768                                         NULL);
2769 
2770                 if (prot->slab == NULL) {
2771                         pr_crit("%s: Can't create sock SLAB cache!\n",
2772                                 prot->name);
2773                         goto out;
2774                 }
2775 
2776                 if (prot->rsk_prot != NULL) {
2777                         prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2778                         if (prot->rsk_prot->slab_name == NULL)
2779                                 goto out_free_sock_slab;
2780 
2781                         prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2782                                                                  prot->rsk_prot->obj_size, 0,
2783                                                                  SLAB_HWCACHE_ALIGN, NULL);
2784 
2785                         if (prot->rsk_prot->slab == NULL) {
2786                                 pr_crit("%s: Can't create request sock SLAB cache!\n",
2787                                         prot->name);
2788                                 goto out_free_request_sock_slab_name;
2789                         }
2790                 }
2791 
2792                 if (prot->twsk_prot != NULL) {
2793                         prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2794 
2795                         if (prot->twsk_prot->twsk_slab_name == NULL)
2796                                 goto out_free_request_sock_slab;
2797 
2798                         prot->twsk_prot->twsk_slab =
2799                                 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2800                                                   prot->twsk_prot->twsk_obj_size,
2801                                                   0,
2802                                                   SLAB_HWCACHE_ALIGN |
2803                                                         prot->slab_flags,
2804                                                   NULL);
2805                         if (prot->twsk_prot->twsk_slab == NULL)
2806                                 goto out_free_timewait_sock_slab_name;
2807                 }
2808         }
2809 
2810         mutex_lock(&proto_list_mutex);
2811         list_add(&prot->node, &proto_list);
2812         assign_proto_idx(prot);
2813         mutex_unlock(&proto_list_mutex);
2814         return 0;
2815 
2816 out_free_timewait_sock_slab_name:
2817         kfree(prot->twsk_prot->twsk_slab_name);
2818 out_free_request_sock_slab:
2819         if (prot->rsk_prot && prot->rsk_prot->slab) {
2820                 kmem_cache_destroy(prot->rsk_prot->slab);
2821                 prot->rsk_prot->slab = NULL;
2822         }
2823 out_free_request_sock_slab_name:
2824         if (prot->rsk_prot)
2825                 kfree(prot->rsk_prot->slab_name);
2826 out_free_sock_slab:
2827         kmem_cache_destroy(prot->slab);
2828         prot->slab = NULL;
2829 out:
2830         return -ENOBUFS;
2831 }
2832 EXPORT_SYMBOL(proto_register);
2833 
2834 void proto_unregister(struct proto *prot)
2835 {
2836         mutex_lock(&proto_list_mutex);
2837         release_proto_idx(prot);
2838         list_del(&prot->node);
2839         mutex_unlock(&proto_list_mutex);
2840 
2841         if (prot->slab != NULL) {
2842                 kmem_cache_destroy(prot->slab);
2843                 prot->slab = NULL;
2844         }
2845 
2846         if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2847                 kmem_cache_destroy(prot->rsk_prot->slab);
2848                 kfree(prot->rsk_prot->slab_name);
2849                 prot->rsk_prot->slab = NULL;
2850         }
2851 
2852         if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2853                 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2854                 kfree(prot->twsk_prot->twsk_slab_name);
2855                 prot->twsk_prot->twsk_slab = NULL;
2856         }
2857 }
2858 EXPORT_SYMBOL(proto_unregister);
2859 
2860 #ifdef CONFIG_PROC_FS
2861 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2862         __acquires(proto_list_mutex)
2863 {
2864         mutex_lock(&proto_list_mutex);
2865         return seq_list_start_head(&proto_list, *pos);
2866 }
2867 
2868 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2869 {
2870         return seq_list_next(v, &proto_list, pos);
2871 }
2872 
2873 static void proto_seq_stop(struct seq_file *seq, void *v)
2874         __releases(proto_list_mutex)
2875 {
2876         mutex_unlock(&proto_list_mutex);
2877 }
2878 
2879 static char proto_method_implemented(const void *method)
2880 {
2881         return method == NULL ? 'n' : 'y';
2882 }
2883 static long sock_prot_memory_allocated(struct proto *proto)
2884 {
2885         return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2886 }
2887 
2888 static char *sock_prot_memory_pressure(struct proto *proto)
2889 {
2890         return proto->memory_pressure != NULL ?
2891         proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2892 }
2893 
2894 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2895 {
2896 
2897         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2898                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2899                    proto->name,
2900                    proto->obj_size,
2901                    sock_prot_inuse_get(seq_file_net(seq), proto),
2902                    sock_prot_memory_allocated(proto),
2903                    sock_prot_memory_pressure(proto),
2904                    proto->max_header,
2905                    proto->slab == NULL ? "no" : "yes",
2906                    module_name(proto->owner),
2907                    proto_method_implemented(proto->close),
2908                    proto_method_implemented(proto->connect),
2909                    proto_method_implemented(proto->disconnect),
2910                    proto_method_implemented(proto->accept),
2911                    proto_method_implemented(proto->ioctl),
2912                    proto_method_implemented(proto->init),
2913                    proto_method_implemented(proto->destroy),
2914                    proto_method_implemented(proto->shutdown),
2915                    proto_method_implemented(proto->setsockopt),
2916                    proto_method_implemented(proto->getsockopt),
2917                    proto_method_implemented(proto->sendmsg),
2918                    proto_method_implemented(proto->recvmsg),
2919                    proto_method_implemented(proto->sendpage),
2920                    proto_method_implemented(proto->bind),
2921                    proto_method_implemented(proto->backlog_rcv),
2922                    proto_method_implemented(proto->hash),
2923                    proto_method_implemented(proto->unhash),
2924                    proto_method_implemented(proto->get_port),
2925                    proto_method_implemented(proto->enter_memory_pressure));
2926 }
2927 
2928 static int proto_seq_show(struct seq_file *seq, void *v)
2929 {
2930         if (v == &proto_list)
2931                 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2932                            "protocol",
2933                            "size",
2934                            "sockets",
2935                            "memory",
2936                            "press",
2937                            "maxhdr",
2938                            "slab",
2939                            "module",
2940                            "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2941         else
2942                 proto_seq_printf(seq, list_entry(v, struct proto, node));
2943         return 0;
2944 }
2945 
2946 static const struct seq_operations proto_seq_ops = {
2947         .start  = proto_seq_start,
2948         .next   = proto_seq_next,
2949         .stop   = proto_seq_stop,
2950         .show   = proto_seq_show,
2951 };
2952 
2953 static int proto_seq_open(struct inode *inode, struct file *file)
2954 {
2955         return seq_open_net(inode, file, &proto_seq_ops,
2956                             sizeof(struct seq_net_private));
2957 }
2958 
2959 static const struct file_operations proto_seq_fops = {
2960         .owner          = THIS_MODULE,
2961         .open           = proto_seq_open,
2962         .read           = seq_read,
2963         .llseek         = seq_lseek,
2964         .release        = seq_release_net,
2965 };
2966 
2967 static __net_init int proto_init_net(struct net *net)
2968 {
2969         if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
2970                 return -ENOMEM;
2971 
2972         return 0;
2973 }
2974 
2975 static __net_exit void proto_exit_net(struct net *net)
2976 {
2977         remove_proc_entry("protocols", net->proc_net);
2978 }
2979 
2980 
2981 static __net_initdata struct pernet_operations proto_net_ops = {
2982         .init = proto_init_net,
2983         .exit = proto_exit_net,
2984 };
2985 
2986 static int __init proto_init(void)
2987 {
2988         return register_pernet_subsys(&proto_net_ops);
2989 }
2990 
2991 subsys_initcall(proto_init);
2992 
2993 #endif /* PROC_FS */
2994 

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