Version:  2.0.40 2.2.26 2.4.37 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 3.16 3.17

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 capability 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 socket 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, 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_tx = 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                 if (val & SOF_TIMESTAMPING_OPT_ID &&
852                     !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
853                         if (sk->sk_protocol == IPPROTO_TCP) {
854                                 if (sk->sk_state != TCP_ESTABLISHED) {
855                                         ret = -EINVAL;
856                                         break;
857                                 }
858                                 sk->sk_tskey = tcp_sk(sk)->snd_una;
859                         } else {
860                                 sk->sk_tskey = 0;
861                         }
862                 }
863                 sk->sk_tsflags = val;
864                 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
865                         sock_enable_timestamp(sk,
866                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
867                 else
868                         sock_disable_timestamp(sk,
869                                                (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
870                 break;
871 
872         case SO_RCVLOWAT:
873                 if (val < 0)
874                         val = INT_MAX;
875                 sk->sk_rcvlowat = val ? : 1;
876                 break;
877 
878         case SO_RCVTIMEO:
879                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
880                 break;
881 
882         case SO_SNDTIMEO:
883                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
884                 break;
885 
886         case SO_ATTACH_FILTER:
887                 ret = -EINVAL;
888                 if (optlen == sizeof(struct sock_fprog)) {
889                         struct sock_fprog fprog;
890 
891                         ret = -EFAULT;
892                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
893                                 break;
894 
895                         ret = sk_attach_filter(&fprog, sk);
896                 }
897                 break;
898 
899         case SO_DETACH_FILTER:
900                 ret = sk_detach_filter(sk);
901                 break;
902 
903         case SO_LOCK_FILTER:
904                 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
905                         ret = -EPERM;
906                 else
907                         sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
908                 break;
909 
910         case SO_PASSSEC:
911                 if (valbool)
912                         set_bit(SOCK_PASSSEC, &sock->flags);
913                 else
914                         clear_bit(SOCK_PASSSEC, &sock->flags);
915                 break;
916         case SO_MARK:
917                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
918                         ret = -EPERM;
919                 else
920                         sk->sk_mark = val;
921                 break;
922 
923                 /* We implement the SO_SNDLOWAT etc to
924                    not be settable (1003.1g 5.3) */
925         case SO_RXQ_OVFL:
926                 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
927                 break;
928 
929         case SO_WIFI_STATUS:
930                 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
931                 break;
932 
933         case SO_PEEK_OFF:
934                 if (sock->ops->set_peek_off)
935                         ret = sock->ops->set_peek_off(sk, val);
936                 else
937                         ret = -EOPNOTSUPP;
938                 break;
939 
940         case SO_NOFCS:
941                 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
942                 break;
943 
944         case SO_SELECT_ERR_QUEUE:
945                 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
946                 break;
947 
948 #ifdef CONFIG_NET_RX_BUSY_POLL
949         case SO_BUSY_POLL:
950                 /* allow unprivileged users to decrease the value */
951                 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
952                         ret = -EPERM;
953                 else {
954                         if (val < 0)
955                                 ret = -EINVAL;
956                         else
957                                 sk->sk_ll_usec = val;
958                 }
959                 break;
960 #endif
961 
962         case SO_MAX_PACING_RATE:
963                 sk->sk_max_pacing_rate = val;
964                 sk->sk_pacing_rate = min(sk->sk_pacing_rate,
965                                          sk->sk_max_pacing_rate);
966                 break;
967 
968         default:
969                 ret = -ENOPROTOOPT;
970                 break;
971         }
972         release_sock(sk);
973         return ret;
974 }
975 EXPORT_SYMBOL(sock_setsockopt);
976 
977 
978 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
979                           struct ucred *ucred)
980 {
981         ucred->pid = pid_vnr(pid);
982         ucred->uid = ucred->gid = -1;
983         if (cred) {
984                 struct user_namespace *current_ns = current_user_ns();
985 
986                 ucred->uid = from_kuid_munged(current_ns, cred->euid);
987                 ucred->gid = from_kgid_munged(current_ns, cred->egid);
988         }
989 }
990 
991 int sock_getsockopt(struct socket *sock, int level, int optname,
992                     char __user *optval, int __user *optlen)
993 {
994         struct sock *sk = sock->sk;
995 
996         union {
997                 int val;
998                 struct linger ling;
999                 struct timeval tm;
1000         } v;
1001 
1002         int lv = sizeof(int);
1003         int len;
1004 
1005         if (get_user(len, optlen))
1006                 return -EFAULT;
1007         if (len < 0)
1008                 return -EINVAL;
1009 
1010         memset(&v, 0, sizeof(v));
1011 
1012         switch (optname) {
1013         case SO_DEBUG:
1014                 v.val = sock_flag(sk, SOCK_DBG);
1015                 break;
1016 
1017         case SO_DONTROUTE:
1018                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
1019                 break;
1020 
1021         case SO_BROADCAST:
1022                 v.val = sock_flag(sk, SOCK_BROADCAST);
1023                 break;
1024 
1025         case SO_SNDBUF:
1026                 v.val = sk->sk_sndbuf;
1027                 break;
1028 
1029         case SO_RCVBUF:
1030                 v.val = sk->sk_rcvbuf;
1031                 break;
1032 
1033         case SO_REUSEADDR:
1034                 v.val = sk->sk_reuse;
1035                 break;
1036 
1037         case SO_REUSEPORT:
1038                 v.val = sk->sk_reuseport;
1039                 break;
1040 
1041         case SO_KEEPALIVE:
1042                 v.val = sock_flag(sk, SOCK_KEEPOPEN);
1043                 break;
1044 
1045         case SO_TYPE:
1046                 v.val = sk->sk_type;
1047                 break;
1048 
1049         case SO_PROTOCOL:
1050                 v.val = sk->sk_protocol;
1051                 break;
1052 
1053         case SO_DOMAIN:
1054                 v.val = sk->sk_family;
1055                 break;
1056 
1057         case SO_ERROR:
1058                 v.val = -sock_error(sk);
1059                 if (v.val == 0)
1060                         v.val = xchg(&sk->sk_err_soft, 0);
1061                 break;
1062 
1063         case SO_OOBINLINE:
1064                 v.val = sock_flag(sk, SOCK_URGINLINE);
1065                 break;
1066 
1067         case SO_NO_CHECK:
1068                 v.val = sk->sk_no_check_tx;
1069                 break;
1070 
1071         case SO_PRIORITY:
1072                 v.val = sk->sk_priority;
1073                 break;
1074 
1075         case SO_LINGER:
1076                 lv              = sizeof(v.ling);
1077                 v.ling.l_onoff  = sock_flag(sk, SOCK_LINGER);
1078                 v.ling.l_linger = sk->sk_lingertime / HZ;
1079                 break;
1080 
1081         case SO_BSDCOMPAT:
1082                 sock_warn_obsolete_bsdism("getsockopt");
1083                 break;
1084 
1085         case SO_TIMESTAMP:
1086                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1087                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1088                 break;
1089 
1090         case SO_TIMESTAMPNS:
1091                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1092                 break;
1093 
1094         case SO_TIMESTAMPING:
1095                 v.val = sk->sk_tsflags;
1096                 break;
1097 
1098         case SO_RCVTIMEO:
1099                 lv = sizeof(struct timeval);
1100                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1101                         v.tm.tv_sec = 0;
1102                         v.tm.tv_usec = 0;
1103                 } else {
1104                         v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1105                         v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1106                 }
1107                 break;
1108 
1109         case SO_SNDTIMEO:
1110                 lv = sizeof(struct timeval);
1111                 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1112                         v.tm.tv_sec = 0;
1113                         v.tm.tv_usec = 0;
1114                 } else {
1115                         v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1116                         v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1117                 }
1118                 break;
1119 
1120         case SO_RCVLOWAT:
1121                 v.val = sk->sk_rcvlowat;
1122                 break;
1123 
1124         case SO_SNDLOWAT:
1125                 v.val = 1;
1126                 break;
1127 
1128         case SO_PASSCRED:
1129                 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1130                 break;
1131 
1132         case SO_PEERCRED:
1133         {
1134                 struct ucred peercred;
1135                 if (len > sizeof(peercred))
1136                         len = sizeof(peercred);
1137                 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1138                 if (copy_to_user(optval, &peercred, len))
1139                         return -EFAULT;
1140                 goto lenout;
1141         }
1142 
1143         case SO_PEERNAME:
1144         {
1145                 char address[128];
1146 
1147                 if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1148                         return -ENOTCONN;
1149                 if (lv < len)
1150                         return -EINVAL;
1151                 if (copy_to_user(optval, address, len))
1152                         return -EFAULT;
1153                 goto lenout;
1154         }
1155 
1156         /* Dubious BSD thing... Probably nobody even uses it, but
1157          * the UNIX standard wants it for whatever reason... -DaveM
1158          */
1159         case SO_ACCEPTCONN:
1160                 v.val = sk->sk_state == TCP_LISTEN;
1161                 break;
1162 
1163         case SO_PASSSEC:
1164                 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1165                 break;
1166 
1167         case SO_PEERSEC:
1168                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1169 
1170         case SO_MARK:
1171                 v.val = sk->sk_mark;
1172                 break;
1173 
1174         case SO_RXQ_OVFL:
1175                 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1176                 break;
1177 
1178         case SO_WIFI_STATUS:
1179                 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1180                 break;
1181 
1182         case SO_PEEK_OFF:
1183                 if (!sock->ops->set_peek_off)
1184                         return -EOPNOTSUPP;
1185 
1186                 v.val = sk->sk_peek_off;
1187                 break;
1188         case SO_NOFCS:
1189                 v.val = sock_flag(sk, SOCK_NOFCS);
1190                 break;
1191 
1192         case SO_BINDTODEVICE:
1193                 return sock_getbindtodevice(sk, optval, optlen, len);
1194 
1195         case SO_GET_FILTER:
1196                 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1197                 if (len < 0)
1198                         return len;
1199 
1200                 goto lenout;
1201 
1202         case SO_LOCK_FILTER:
1203                 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1204                 break;
1205 
1206         case SO_BPF_EXTENSIONS:
1207                 v.val = bpf_tell_extensions();
1208                 break;
1209 
1210         case SO_SELECT_ERR_QUEUE:
1211                 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1212                 break;
1213 
1214 #ifdef CONFIG_NET_RX_BUSY_POLL
1215         case SO_BUSY_POLL:
1216                 v.val = sk->sk_ll_usec;
1217                 break;
1218 #endif
1219 
1220         case SO_MAX_PACING_RATE:
1221                 v.val = sk->sk_max_pacing_rate;
1222                 break;
1223 
1224         default:
1225                 return -ENOPROTOOPT;
1226         }
1227 
1228         if (len > lv)
1229                 len = lv;
1230         if (copy_to_user(optval, &v, len))
1231                 return -EFAULT;
1232 lenout:
1233         if (put_user(len, optlen))
1234                 return -EFAULT;
1235         return 0;
1236 }
1237 
1238 /*
1239  * Initialize an sk_lock.
1240  *
1241  * (We also register the sk_lock with the lock validator.)
1242  */
1243 static inline void sock_lock_init(struct sock *sk)
1244 {
1245         sock_lock_init_class_and_name(sk,
1246                         af_family_slock_key_strings[sk->sk_family],
1247                         af_family_slock_keys + sk->sk_family,
1248                         af_family_key_strings[sk->sk_family],
1249                         af_family_keys + sk->sk_family);
1250 }
1251 
1252 /*
1253  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1254  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1255  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1256  */
1257 static void sock_copy(struct sock *nsk, const struct sock *osk)
1258 {
1259 #ifdef CONFIG_SECURITY_NETWORK
1260         void *sptr = nsk->sk_security;
1261 #endif
1262         memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1263 
1264         memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1265                osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1266 
1267 #ifdef CONFIG_SECURITY_NETWORK
1268         nsk->sk_security = sptr;
1269         security_sk_clone(osk, nsk);
1270 #endif
1271 }
1272 
1273 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1274 {
1275         unsigned long nulls1, nulls2;
1276 
1277         nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1278         nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1279         if (nulls1 > nulls2)
1280                 swap(nulls1, nulls2);
1281 
1282         if (nulls1 != 0)
1283                 memset((char *)sk, 0, nulls1);
1284         memset((char *)sk + nulls1 + sizeof(void *), 0,
1285                nulls2 - nulls1 - sizeof(void *));
1286         memset((char *)sk + nulls2 + sizeof(void *), 0,
1287                size - nulls2 - sizeof(void *));
1288 }
1289 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1290 
1291 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1292                 int family)
1293 {
1294         struct sock *sk;
1295         struct kmem_cache *slab;
1296 
1297         slab = prot->slab;
1298         if (slab != NULL) {
1299                 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1300                 if (!sk)
1301                         return sk;
1302                 if (priority & __GFP_ZERO) {
1303                         if (prot->clear_sk)
1304                                 prot->clear_sk(sk, prot->obj_size);
1305                         else
1306                                 sk_prot_clear_nulls(sk, prot->obj_size);
1307                 }
1308         } else
1309                 sk = kmalloc(prot->obj_size, priority);
1310 
1311         if (sk != NULL) {
1312                 kmemcheck_annotate_bitfield(sk, flags);
1313 
1314                 if (security_sk_alloc(sk, family, priority))
1315                         goto out_free;
1316 
1317                 if (!try_module_get(prot->owner))
1318                         goto out_free_sec;
1319                 sk_tx_queue_clear(sk);
1320         }
1321 
1322         return sk;
1323 
1324 out_free_sec:
1325         security_sk_free(sk);
1326 out_free:
1327         if (slab != NULL)
1328                 kmem_cache_free(slab, sk);
1329         else
1330                 kfree(sk);
1331         return NULL;
1332 }
1333 
1334 static void sk_prot_free(struct proto *prot, struct sock *sk)
1335 {
1336         struct kmem_cache *slab;
1337         struct module *owner;
1338 
1339         owner = prot->owner;
1340         slab = prot->slab;
1341 
1342         security_sk_free(sk);
1343         if (slab != NULL)
1344                 kmem_cache_free(slab, sk);
1345         else
1346                 kfree(sk);
1347         module_put(owner);
1348 }
1349 
1350 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
1351 void sock_update_netprioidx(struct sock *sk)
1352 {
1353         if (in_interrupt())
1354                 return;
1355 
1356         sk->sk_cgrp_prioidx = task_netprioidx(current);
1357 }
1358 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1359 #endif
1360 
1361 /**
1362  *      sk_alloc - All socket objects are allocated here
1363  *      @net: the applicable net namespace
1364  *      @family: protocol family
1365  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1366  *      @prot: struct proto associated with this new sock instance
1367  */
1368 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1369                       struct proto *prot)
1370 {
1371         struct sock *sk;
1372 
1373         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1374         if (sk) {
1375                 sk->sk_family = family;
1376                 /*
1377                  * See comment in struct sock definition to understand
1378                  * why we need sk_prot_creator -acme
1379                  */
1380                 sk->sk_prot = sk->sk_prot_creator = prot;
1381                 sock_lock_init(sk);
1382                 sock_net_set(sk, get_net(net));
1383                 atomic_set(&sk->sk_wmem_alloc, 1);
1384 
1385                 sock_update_classid(sk);
1386                 sock_update_netprioidx(sk);
1387         }
1388 
1389         return sk;
1390 }
1391 EXPORT_SYMBOL(sk_alloc);
1392 
1393 static void __sk_free(struct sock *sk)
1394 {
1395         struct sk_filter *filter;
1396 
1397         if (sk->sk_destruct)
1398                 sk->sk_destruct(sk);
1399 
1400         filter = rcu_dereference_check(sk->sk_filter,
1401                                        atomic_read(&sk->sk_wmem_alloc) == 0);
1402         if (filter) {
1403                 sk_filter_uncharge(sk, filter);
1404                 RCU_INIT_POINTER(sk->sk_filter, NULL);
1405         }
1406 
1407         sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1408 
1409         if (atomic_read(&sk->sk_omem_alloc))
1410                 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1411                          __func__, atomic_read(&sk->sk_omem_alloc));
1412 
1413         if (sk->sk_peer_cred)
1414                 put_cred(sk->sk_peer_cred);
1415         put_pid(sk->sk_peer_pid);
1416         put_net(sock_net(sk));
1417         sk_prot_free(sk->sk_prot_creator, sk);
1418 }
1419 
1420 void sk_free(struct sock *sk)
1421 {
1422         /*
1423          * We subtract one from sk_wmem_alloc and can know if
1424          * some packets are still in some tx queue.
1425          * If not null, sock_wfree() will call __sk_free(sk) later
1426          */
1427         if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1428                 __sk_free(sk);
1429 }
1430 EXPORT_SYMBOL(sk_free);
1431 
1432 /*
1433  * Last sock_put should drop reference to sk->sk_net. It has already
1434  * been dropped in sk_change_net. Taking reference to stopping namespace
1435  * is not an option.
1436  * Take reference to a socket to remove it from hash _alive_ and after that
1437  * destroy it in the context of init_net.
1438  */
1439 void sk_release_kernel(struct sock *sk)
1440 {
1441         if (sk == NULL || sk->sk_socket == NULL)
1442                 return;
1443 
1444         sock_hold(sk);
1445         sock_release(sk->sk_socket);
1446         release_net(sock_net(sk));
1447         sock_net_set(sk, get_net(&init_net));
1448         sock_put(sk);
1449 }
1450 EXPORT_SYMBOL(sk_release_kernel);
1451 
1452 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1453 {
1454         if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1455                 sock_update_memcg(newsk);
1456 }
1457 
1458 /**
1459  *      sk_clone_lock - clone a socket, and lock its clone
1460  *      @sk: the socket to clone
1461  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1462  *
1463  *      Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1464  */
1465 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1466 {
1467         struct sock *newsk;
1468         bool is_charged = true;
1469 
1470         newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1471         if (newsk != NULL) {
1472                 struct sk_filter *filter;
1473 
1474                 sock_copy(newsk, sk);
1475 
1476                 /* SANITY */
1477                 get_net(sock_net(newsk));
1478                 sk_node_init(&newsk->sk_node);
1479                 sock_lock_init(newsk);
1480                 bh_lock_sock(newsk);
1481                 newsk->sk_backlog.head  = newsk->sk_backlog.tail = NULL;
1482                 newsk->sk_backlog.len = 0;
1483 
1484                 atomic_set(&newsk->sk_rmem_alloc, 0);
1485                 /*
1486                  * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1487                  */
1488                 atomic_set(&newsk->sk_wmem_alloc, 1);
1489                 atomic_set(&newsk->sk_omem_alloc, 0);
1490                 skb_queue_head_init(&newsk->sk_receive_queue);
1491                 skb_queue_head_init(&newsk->sk_write_queue);
1492 #ifdef CONFIG_NET_DMA
1493                 skb_queue_head_init(&newsk->sk_async_wait_queue);
1494 #endif
1495 
1496                 spin_lock_init(&newsk->sk_dst_lock);
1497                 rwlock_init(&newsk->sk_callback_lock);
1498                 lockdep_set_class_and_name(&newsk->sk_callback_lock,
1499                                 af_callback_keys + newsk->sk_family,
1500                                 af_family_clock_key_strings[newsk->sk_family]);
1501 
1502                 newsk->sk_dst_cache     = NULL;
1503                 newsk->sk_wmem_queued   = 0;
1504                 newsk->sk_forward_alloc = 0;
1505                 newsk->sk_send_head     = NULL;
1506                 newsk->sk_userlocks     = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1507 
1508                 sock_reset_flag(newsk, SOCK_DONE);
1509                 skb_queue_head_init(&newsk->sk_error_queue);
1510 
1511                 filter = rcu_dereference_protected(newsk->sk_filter, 1);
1512                 if (filter != NULL)
1513                         /* though it's an empty new sock, the charging may fail
1514                          * if sysctl_optmem_max was changed between creation of
1515                          * original socket and cloning
1516                          */
1517                         is_charged = sk_filter_charge(newsk, filter);
1518 
1519                 if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk))) {
1520                         /* It is still raw copy of parent, so invalidate
1521                          * destructor and make plain sk_free() */
1522                         newsk->sk_destruct = NULL;
1523                         bh_unlock_sock(newsk);
1524                         sk_free(newsk);
1525                         newsk = NULL;
1526                         goto out;
1527                 }
1528 
1529                 newsk->sk_err      = 0;
1530                 newsk->sk_priority = 0;
1531                 /*
1532                  * Before updating sk_refcnt, we must commit prior changes to memory
1533                  * (Documentation/RCU/rculist_nulls.txt for details)
1534                  */
1535                 smp_wmb();
1536                 atomic_set(&newsk->sk_refcnt, 2);
1537 
1538                 /*
1539                  * Increment the counter in the same struct proto as the master
1540                  * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1541                  * is the same as sk->sk_prot->socks, as this field was copied
1542                  * with memcpy).
1543                  *
1544                  * This _changes_ the previous behaviour, where
1545                  * tcp_create_openreq_child always was incrementing the
1546                  * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1547                  * to be taken into account in all callers. -acme
1548                  */
1549                 sk_refcnt_debug_inc(newsk);
1550                 sk_set_socket(newsk, NULL);
1551                 newsk->sk_wq = NULL;
1552 
1553                 sk_update_clone(sk, newsk);
1554 
1555                 if (newsk->sk_prot->sockets_allocated)
1556                         sk_sockets_allocated_inc(newsk);
1557 
1558                 if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1559                         net_enable_timestamp();
1560         }
1561 out:
1562         return newsk;
1563 }
1564 EXPORT_SYMBOL_GPL(sk_clone_lock);
1565 
1566 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1567 {
1568         __sk_dst_set(sk, dst);
1569         sk->sk_route_caps = dst->dev->features;
1570         if (sk->sk_route_caps & NETIF_F_GSO)
1571                 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1572         sk->sk_route_caps &= ~sk->sk_route_nocaps;
1573         if (sk_can_gso(sk)) {
1574                 if (dst->header_len) {
1575                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1576                 } else {
1577                         sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1578                         sk->sk_gso_max_size = dst->dev->gso_max_size;
1579                         sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1580                 }
1581         }
1582 }
1583 EXPORT_SYMBOL_GPL(sk_setup_caps);
1584 
1585 /*
1586  *      Simple resource managers for sockets.
1587  */
1588 
1589 
1590 /*
1591  * Write buffer destructor automatically called from kfree_skb.
1592  */
1593 void sock_wfree(struct sk_buff *skb)
1594 {
1595         struct sock *sk = skb->sk;
1596         unsigned int len = skb->truesize;
1597 
1598         if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1599                 /*
1600                  * Keep a reference on sk_wmem_alloc, this will be released
1601                  * after sk_write_space() call
1602                  */
1603                 atomic_sub(len - 1, &sk->sk_wmem_alloc);
1604                 sk->sk_write_space(sk);
1605                 len = 1;
1606         }
1607         /*
1608          * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1609          * could not do because of in-flight packets
1610          */
1611         if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1612                 __sk_free(sk);
1613 }
1614 EXPORT_SYMBOL(sock_wfree);
1615 
1616 void skb_orphan_partial(struct sk_buff *skb)
1617 {
1618         /* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1619          * so we do not completely orphan skb, but transfert all
1620          * accounted bytes but one, to avoid unexpected reorders.
1621          */
1622         if (skb->destructor == sock_wfree
1623 #ifdef CONFIG_INET
1624             || skb->destructor == tcp_wfree
1625 #endif
1626                 ) {
1627                 atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1628                 skb->truesize = 1;
1629         } else {
1630                 skb_orphan(skb);
1631         }
1632 }
1633 EXPORT_SYMBOL(skb_orphan_partial);
1634 
1635 /*
1636  * Read buffer destructor automatically called from kfree_skb.
1637  */
1638 void sock_rfree(struct sk_buff *skb)
1639 {
1640         struct sock *sk = skb->sk;
1641         unsigned int len = skb->truesize;
1642 
1643         atomic_sub(len, &sk->sk_rmem_alloc);
1644         sk_mem_uncharge(sk, len);
1645 }
1646 EXPORT_SYMBOL(sock_rfree);
1647 
1648 void sock_edemux(struct sk_buff *skb)
1649 {
1650         struct sock *sk = skb->sk;
1651 
1652 #ifdef CONFIG_INET
1653         if (sk->sk_state == TCP_TIME_WAIT)
1654                 inet_twsk_put(inet_twsk(sk));
1655         else
1656 #endif
1657                 sock_put(sk);
1658 }
1659 EXPORT_SYMBOL(sock_edemux);
1660 
1661 kuid_t sock_i_uid(struct sock *sk)
1662 {
1663         kuid_t uid;
1664 
1665         read_lock_bh(&sk->sk_callback_lock);
1666         uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1667         read_unlock_bh(&sk->sk_callback_lock);
1668         return uid;
1669 }
1670 EXPORT_SYMBOL(sock_i_uid);
1671 
1672 unsigned long sock_i_ino(struct sock *sk)
1673 {
1674         unsigned long ino;
1675 
1676         read_lock_bh(&sk->sk_callback_lock);
1677         ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1678         read_unlock_bh(&sk->sk_callback_lock);
1679         return ino;
1680 }
1681 EXPORT_SYMBOL(sock_i_ino);
1682 
1683 /*
1684  * Allocate a skb from the socket's send buffer.
1685  */
1686 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1687                              gfp_t priority)
1688 {
1689         if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1690                 struct sk_buff *skb = alloc_skb(size, priority);
1691                 if (skb) {
1692                         skb_set_owner_w(skb, sk);
1693                         return skb;
1694                 }
1695         }
1696         return NULL;
1697 }
1698 EXPORT_SYMBOL(sock_wmalloc);
1699 
1700 /*
1701  * Allocate a memory block from the socket's option memory buffer.
1702  */
1703 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1704 {
1705         if ((unsigned int)size <= sysctl_optmem_max &&
1706             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1707                 void *mem;
1708                 /* First do the add, to avoid the race if kmalloc
1709                  * might sleep.
1710                  */
1711                 atomic_add(size, &sk->sk_omem_alloc);
1712                 mem = kmalloc(size, priority);
1713                 if (mem)
1714                         return mem;
1715                 atomic_sub(size, &sk->sk_omem_alloc);
1716         }
1717         return NULL;
1718 }
1719 EXPORT_SYMBOL(sock_kmalloc);
1720 
1721 /*
1722  * Free an option memory block.
1723  */
1724 void sock_kfree_s(struct sock *sk, void *mem, int size)
1725 {
1726         kfree(mem);
1727         atomic_sub(size, &sk->sk_omem_alloc);
1728 }
1729 EXPORT_SYMBOL(sock_kfree_s);
1730 
1731 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1732    I think, these locks should be removed for datagram sockets.
1733  */
1734 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1735 {
1736         DEFINE_WAIT(wait);
1737 
1738         clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1739         for (;;) {
1740                 if (!timeo)
1741                         break;
1742                 if (signal_pending(current))
1743                         break;
1744                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1745                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1746                 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1747                         break;
1748                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1749                         break;
1750                 if (sk->sk_err)
1751                         break;
1752                 timeo = schedule_timeout(timeo);
1753         }
1754         finish_wait(sk_sleep(sk), &wait);
1755         return timeo;
1756 }
1757 
1758 
1759 /*
1760  *      Generic send/receive buffer handlers
1761  */
1762 
1763 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1764                                      unsigned long data_len, int noblock,
1765                                      int *errcode, int max_page_order)
1766 {
1767         struct sk_buff *skb = NULL;
1768         unsigned long chunk;
1769         gfp_t gfp_mask;
1770         long timeo;
1771         int err;
1772         int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1773         struct page *page;
1774         int i;
1775 
1776         err = -EMSGSIZE;
1777         if (npages > MAX_SKB_FRAGS)
1778                 goto failure;
1779 
1780         timeo = sock_sndtimeo(sk, noblock);
1781         while (!skb) {
1782                 err = sock_error(sk);
1783                 if (err != 0)
1784                         goto failure;
1785 
1786                 err = -EPIPE;
1787                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1788                         goto failure;
1789 
1790                 if (atomic_read(&sk->sk_wmem_alloc) >= sk->sk_sndbuf) {
1791                         set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1792                         set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1793                         err = -EAGAIN;
1794                         if (!timeo)
1795                                 goto failure;
1796                         if (signal_pending(current))
1797                                 goto interrupted;
1798                         timeo = sock_wait_for_wmem(sk, timeo);
1799                         continue;
1800                 }
1801 
1802                 err = -ENOBUFS;
1803                 gfp_mask = sk->sk_allocation;
1804                 if (gfp_mask & __GFP_WAIT)
1805                         gfp_mask |= __GFP_REPEAT;
1806 
1807                 skb = alloc_skb(header_len, gfp_mask);
1808                 if (!skb)
1809                         goto failure;
1810 
1811                 skb->truesize += data_len;
1812 
1813                 for (i = 0; npages > 0; i++) {
1814                         int order = max_page_order;
1815 
1816                         while (order) {
1817                                 if (npages >= 1 << order) {
1818                                         page = alloc_pages(sk->sk_allocation |
1819                                                            __GFP_COMP |
1820                                                            __GFP_NOWARN |
1821                                                            __GFP_NORETRY,
1822                                                            order);
1823                                         if (page)
1824                                                 goto fill_page;
1825                                         /* Do not retry other high order allocations */
1826                                         order = 1;
1827                                         max_page_order = 0;
1828                                 }
1829                                 order--;
1830                         }
1831                         page = alloc_page(sk->sk_allocation);
1832                         if (!page)
1833                                 goto failure;
1834 fill_page:
1835                         chunk = min_t(unsigned long, data_len,
1836                                       PAGE_SIZE << order);
1837                         skb_fill_page_desc(skb, i, page, 0, chunk);
1838                         data_len -= chunk;
1839                         npages -= 1 << order;
1840                 }
1841         }
1842 
1843         skb_set_owner_w(skb, sk);
1844         return skb;
1845 
1846 interrupted:
1847         err = sock_intr_errno(timeo);
1848 failure:
1849         kfree_skb(skb);
1850         *errcode = err;
1851         return NULL;
1852 }
1853 EXPORT_SYMBOL(sock_alloc_send_pskb);
1854 
1855 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1856                                     int noblock, int *errcode)
1857 {
1858         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1859 }
1860 EXPORT_SYMBOL(sock_alloc_send_skb);
1861 
1862 /* On 32bit arches, an skb frag is limited to 2^15 */
1863 #define SKB_FRAG_PAGE_ORDER     get_order(32768)
1864 
1865 /**
1866  * skb_page_frag_refill - check that a page_frag contains enough room
1867  * @sz: minimum size of the fragment we want to get
1868  * @pfrag: pointer to page_frag
1869  * @gfp: priority for memory allocation
1870  *
1871  * Note: While this allocator tries to use high order pages, there is
1872  * no guarantee that allocations succeed. Therefore, @sz MUST be
1873  * less or equal than PAGE_SIZE.
1874  */
1875 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
1876 {
1877         if (pfrag->page) {
1878                 if (atomic_read(&pfrag->page->_count) == 1) {
1879                         pfrag->offset = 0;
1880                         return true;
1881                 }
1882                 if (pfrag->offset + sz <= pfrag->size)
1883                         return true;
1884                 put_page(pfrag->page);
1885         }
1886 
1887         pfrag->offset = 0;
1888         if (SKB_FRAG_PAGE_ORDER) {
1889                 pfrag->page = alloc_pages(gfp | __GFP_COMP |
1890                                           __GFP_NOWARN | __GFP_NORETRY,
1891                                           SKB_FRAG_PAGE_ORDER);
1892                 if (likely(pfrag->page)) {
1893                         pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
1894                         return true;
1895                 }
1896         }
1897         pfrag->page = alloc_page(gfp);
1898         if (likely(pfrag->page)) {
1899                 pfrag->size = PAGE_SIZE;
1900                 return true;
1901         }
1902         return false;
1903 }
1904 EXPORT_SYMBOL(skb_page_frag_refill);
1905 
1906 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1907 {
1908         if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1909                 return true;
1910 
1911         sk_enter_memory_pressure(sk);
1912         sk_stream_moderate_sndbuf(sk);
1913         return false;
1914 }
1915 EXPORT_SYMBOL(sk_page_frag_refill);
1916 
1917 static void __lock_sock(struct sock *sk)
1918         __releases(&sk->sk_lock.slock)
1919         __acquires(&sk->sk_lock.slock)
1920 {
1921         DEFINE_WAIT(wait);
1922 
1923         for (;;) {
1924                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1925                                         TASK_UNINTERRUPTIBLE);
1926                 spin_unlock_bh(&sk->sk_lock.slock);
1927                 schedule();
1928                 spin_lock_bh(&sk->sk_lock.slock);
1929                 if (!sock_owned_by_user(sk))
1930                         break;
1931         }
1932         finish_wait(&sk->sk_lock.wq, &wait);
1933 }
1934 
1935 static void __release_sock(struct sock *sk)
1936         __releases(&sk->sk_lock.slock)
1937         __acquires(&sk->sk_lock.slock)
1938 {
1939         struct sk_buff *skb = sk->sk_backlog.head;
1940 
1941         do {
1942                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1943                 bh_unlock_sock(sk);
1944 
1945                 do {
1946                         struct sk_buff *next = skb->next;
1947 
1948                         prefetch(next);
1949                         WARN_ON_ONCE(skb_dst_is_noref(skb));
1950                         skb->next = NULL;
1951                         sk_backlog_rcv(sk, skb);
1952 
1953                         /*
1954                          * We are in process context here with softirqs
1955                          * disabled, use cond_resched_softirq() to preempt.
1956                          * This is safe to do because we've taken the backlog
1957                          * queue private:
1958                          */
1959                         cond_resched_softirq();
1960 
1961                         skb = next;
1962                 } while (skb != NULL);
1963 
1964                 bh_lock_sock(sk);
1965         } while ((skb = sk->sk_backlog.head) != NULL);
1966 
1967         /*
1968          * Doing the zeroing here guarantee we can not loop forever
1969          * while a wild producer attempts to flood us.
1970          */
1971         sk->sk_backlog.len = 0;
1972 }
1973 
1974 /**
1975  * sk_wait_data - wait for data to arrive at sk_receive_queue
1976  * @sk:    sock to wait on
1977  * @timeo: for how long
1978  *
1979  * Now socket state including sk->sk_err is changed only under lock,
1980  * hence we may omit checks after joining wait queue.
1981  * We check receive queue before schedule() only as optimization;
1982  * it is very likely that release_sock() added new data.
1983  */
1984 int sk_wait_data(struct sock *sk, long *timeo)
1985 {
1986         int rc;
1987         DEFINE_WAIT(wait);
1988 
1989         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1990         set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1991         rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1992         clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1993         finish_wait(sk_sleep(sk), &wait);
1994         return rc;
1995 }
1996 EXPORT_SYMBOL(sk_wait_data);
1997 
1998 /**
1999  *      __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2000  *      @sk: socket
2001  *      @size: memory size to allocate
2002  *      @kind: allocation type
2003  *
2004  *      If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2005  *      rmem allocation. This function assumes that protocols which have
2006  *      memory_pressure use sk_wmem_queued as write buffer accounting.
2007  */
2008 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2009 {
2010         struct proto *prot = sk->sk_prot;
2011         int amt = sk_mem_pages(size);
2012         long allocated;
2013         int parent_status = UNDER_LIMIT;
2014 
2015         sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
2016 
2017         allocated = sk_memory_allocated_add(sk, amt, &parent_status);
2018 
2019         /* Under limit. */
2020         if (parent_status == UNDER_LIMIT &&
2021                         allocated <= sk_prot_mem_limits(sk, 0)) {
2022                 sk_leave_memory_pressure(sk);
2023                 return 1;
2024         }
2025 
2026         /* Under pressure. (we or our parents) */
2027         if ((parent_status > SOFT_LIMIT) ||
2028                         allocated > sk_prot_mem_limits(sk, 1))
2029                 sk_enter_memory_pressure(sk);
2030 
2031         /* Over hard limit (we or our parents) */
2032         if ((parent_status == OVER_LIMIT) ||
2033                         (allocated > sk_prot_mem_limits(sk, 2)))
2034                 goto suppress_allocation;
2035 
2036         /* guarantee minimum buffer size under pressure */
2037         if (kind == SK_MEM_RECV) {
2038                 if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2039                         return 1;
2040 
2041         } else { /* SK_MEM_SEND */
2042                 if (sk->sk_type == SOCK_STREAM) {
2043                         if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2044                                 return 1;
2045                 } else if (atomic_read(&sk->sk_wmem_alloc) <
2046                            prot->sysctl_wmem[0])
2047                                 return 1;
2048         }
2049 
2050         if (sk_has_memory_pressure(sk)) {
2051                 int alloc;
2052 
2053                 if (!sk_under_memory_pressure(sk))
2054                         return 1;
2055                 alloc = sk_sockets_allocated_read_positive(sk);
2056                 if (sk_prot_mem_limits(sk, 2) > alloc *
2057                     sk_mem_pages(sk->sk_wmem_queued +
2058                                  atomic_read(&sk->sk_rmem_alloc) +
2059                                  sk->sk_forward_alloc))
2060                         return 1;
2061         }
2062 
2063 suppress_allocation:
2064 
2065         if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2066                 sk_stream_moderate_sndbuf(sk);
2067 
2068                 /* Fail only if socket is _under_ its sndbuf.
2069                  * In this case we cannot block, so that we have to fail.
2070                  */
2071                 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2072                         return 1;
2073         }
2074 
2075         trace_sock_exceed_buf_limit(sk, prot, allocated);
2076 
2077         /* Alas. Undo changes. */
2078         sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2079 
2080         sk_memory_allocated_sub(sk, amt);
2081 
2082         return 0;
2083 }
2084 EXPORT_SYMBOL(__sk_mem_schedule);
2085 
2086 /**
2087  *      __sk_reclaim - reclaim memory_allocated
2088  *      @sk: socket
2089  */
2090 void __sk_mem_reclaim(struct sock *sk)
2091 {
2092         sk_memory_allocated_sub(sk,
2093                                 sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
2094         sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
2095 
2096         if (sk_under_memory_pressure(sk) &&
2097             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2098                 sk_leave_memory_pressure(sk);
2099 }
2100 EXPORT_SYMBOL(__sk_mem_reclaim);
2101 
2102 
2103 /*
2104  * Set of default routines for initialising struct proto_ops when
2105  * the protocol does not support a particular function. In certain
2106  * cases where it makes no sense for a protocol to have a "do nothing"
2107  * function, some default processing is provided.
2108  */
2109 
2110 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2111 {
2112         return -EOPNOTSUPP;
2113 }
2114 EXPORT_SYMBOL(sock_no_bind);
2115 
2116 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2117                     int len, int flags)
2118 {
2119         return -EOPNOTSUPP;
2120 }
2121 EXPORT_SYMBOL(sock_no_connect);
2122 
2123 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2124 {
2125         return -EOPNOTSUPP;
2126 }
2127 EXPORT_SYMBOL(sock_no_socketpair);
2128 
2129 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2130 {
2131         return -EOPNOTSUPP;
2132 }
2133 EXPORT_SYMBOL(sock_no_accept);
2134 
2135 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2136                     int *len, int peer)
2137 {
2138         return -EOPNOTSUPP;
2139 }
2140 EXPORT_SYMBOL(sock_no_getname);
2141 
2142 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2143 {
2144         return 0;
2145 }
2146 EXPORT_SYMBOL(sock_no_poll);
2147 
2148 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2149 {
2150         return -EOPNOTSUPP;
2151 }
2152 EXPORT_SYMBOL(sock_no_ioctl);
2153 
2154 int sock_no_listen(struct socket *sock, int backlog)
2155 {
2156         return -EOPNOTSUPP;
2157 }
2158 EXPORT_SYMBOL(sock_no_listen);
2159 
2160 int sock_no_shutdown(struct socket *sock, int how)
2161 {
2162         return -EOPNOTSUPP;
2163 }
2164 EXPORT_SYMBOL(sock_no_shutdown);
2165 
2166 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2167                     char __user *optval, unsigned int optlen)
2168 {
2169         return -EOPNOTSUPP;
2170 }
2171 EXPORT_SYMBOL(sock_no_setsockopt);
2172 
2173 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2174                     char __user *optval, int __user *optlen)
2175 {
2176         return -EOPNOTSUPP;
2177 }
2178 EXPORT_SYMBOL(sock_no_getsockopt);
2179 
2180 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2181                     size_t len)
2182 {
2183         return -EOPNOTSUPP;
2184 }
2185 EXPORT_SYMBOL(sock_no_sendmsg);
2186 
2187 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2188                     size_t len, int flags)
2189 {
2190         return -EOPNOTSUPP;
2191 }
2192 EXPORT_SYMBOL(sock_no_recvmsg);
2193 
2194 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2195 {
2196         /* Mirror missing mmap method error code */
2197         return -ENODEV;
2198 }
2199 EXPORT_SYMBOL(sock_no_mmap);
2200 
2201 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2202 {
2203         ssize_t res;
2204         struct msghdr msg = {.msg_flags = flags};
2205         struct kvec iov;
2206         char *kaddr = kmap(page);
2207         iov.iov_base = kaddr + offset;
2208         iov.iov_len = size;
2209         res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2210         kunmap(page);
2211         return res;
2212 }
2213 EXPORT_SYMBOL(sock_no_sendpage);
2214 
2215 /*
2216  *      Default Socket Callbacks
2217  */
2218 
2219 static void sock_def_wakeup(struct sock *sk)
2220 {
2221         struct socket_wq *wq;
2222 
2223         rcu_read_lock();
2224         wq = rcu_dereference(sk->sk_wq);
2225         if (wq_has_sleeper(wq))
2226                 wake_up_interruptible_all(&wq->wait);
2227         rcu_read_unlock();
2228 }
2229 
2230 static void sock_def_error_report(struct sock *sk)
2231 {
2232         struct socket_wq *wq;
2233 
2234         rcu_read_lock();
2235         wq = rcu_dereference(sk->sk_wq);
2236         if (wq_has_sleeper(wq))
2237                 wake_up_interruptible_poll(&wq->wait, POLLERR);
2238         sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2239         rcu_read_unlock();
2240 }
2241 
2242 static void sock_def_readable(struct sock *sk)
2243 {
2244         struct socket_wq *wq;
2245 
2246         rcu_read_lock();
2247         wq = rcu_dereference(sk->sk_wq);
2248         if (wq_has_sleeper(wq))
2249                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2250                                                 POLLRDNORM | POLLRDBAND);
2251         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2252         rcu_read_unlock();
2253 }
2254 
2255 static void sock_def_write_space(struct sock *sk)
2256 {
2257         struct socket_wq *wq;
2258 
2259         rcu_read_lock();
2260 
2261         /* Do not wake up a writer until he can make "significant"
2262          * progress.  --DaveM
2263          */
2264         if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2265                 wq = rcu_dereference(sk->sk_wq);
2266                 if (wq_has_sleeper(wq))
2267                         wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2268                                                 POLLWRNORM | POLLWRBAND);
2269 
2270                 /* Should agree with poll, otherwise some programs break */
2271                 if (sock_writeable(sk))
2272                         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2273         }
2274 
2275         rcu_read_unlock();
2276 }
2277 
2278 static void sock_def_destruct(struct sock *sk)
2279 {
2280         kfree(sk->sk_protinfo);
2281 }
2282 
2283 void sk_send_sigurg(struct sock *sk)
2284 {
2285         if (sk->sk_socket && sk->sk_socket->file)
2286                 if (send_sigurg(&sk->sk_socket->file->f_owner))
2287                         sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2288 }
2289 EXPORT_SYMBOL(sk_send_sigurg);
2290 
2291 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2292                     unsigned long expires)
2293 {
2294         if (!mod_timer(timer, expires))
2295                 sock_hold(sk);
2296 }
2297 EXPORT_SYMBOL(sk_reset_timer);
2298 
2299 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2300 {
2301         if (del_timer(timer))
2302                 __sock_put(sk);
2303 }
2304 EXPORT_SYMBOL(sk_stop_timer);
2305 
2306 void sock_init_data(struct socket *sock, struct sock *sk)
2307 {
2308         skb_queue_head_init(&sk->sk_receive_queue);
2309         skb_queue_head_init(&sk->sk_write_queue);
2310         skb_queue_head_init(&sk->sk_error_queue);
2311 #ifdef CONFIG_NET_DMA
2312         skb_queue_head_init(&sk->sk_async_wait_queue);
2313 #endif
2314 
2315         sk->sk_send_head        =       NULL;
2316 
2317         init_timer(&sk->sk_timer);
2318 
2319         sk->sk_allocation       =       GFP_KERNEL;
2320         sk->sk_rcvbuf           =       sysctl_rmem_default;
2321         sk->sk_sndbuf           =       sysctl_wmem_default;
2322         sk->sk_state            =       TCP_CLOSE;
2323         sk_set_socket(sk, sock);
2324 
2325         sock_set_flag(sk, SOCK_ZAPPED);
2326 
2327         if (sock) {
2328                 sk->sk_type     =       sock->type;
2329                 sk->sk_wq       =       sock->wq;
2330                 sock->sk        =       sk;
2331         } else
2332                 sk->sk_wq       =       NULL;
2333 
2334         spin_lock_init(&sk->sk_dst_lock);
2335         rwlock_init(&sk->sk_callback_lock);
2336         lockdep_set_class_and_name(&sk->sk_callback_lock,
2337                         af_callback_keys + sk->sk_family,
2338                         af_family_clock_key_strings[sk->sk_family]);
2339 
2340         sk->sk_state_change     =       sock_def_wakeup;
2341         sk->sk_data_ready       =       sock_def_readable;
2342         sk->sk_write_space      =       sock_def_write_space;
2343         sk->sk_error_report     =       sock_def_error_report;
2344         sk->sk_destruct         =       sock_def_destruct;
2345 
2346         sk->sk_frag.page        =       NULL;
2347         sk->sk_frag.offset      =       0;
2348         sk->sk_peek_off         =       -1;
2349 
2350         sk->sk_peer_pid         =       NULL;
2351         sk->sk_peer_cred        =       NULL;
2352         sk->sk_write_pending    =       0;
2353         sk->sk_rcvlowat         =       1;
2354         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
2355         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
2356 
2357         sk->sk_stamp = ktime_set(-1L, 0);
2358 
2359 #ifdef CONFIG_NET_RX_BUSY_POLL
2360         sk->sk_napi_id          =       0;
2361         sk->sk_ll_usec          =       sysctl_net_busy_read;
2362 #endif
2363 
2364         sk->sk_max_pacing_rate = ~0U;
2365         sk->sk_pacing_rate = ~0U;
2366         /*
2367          * Before updating sk_refcnt, we must commit prior changes to memory
2368          * (Documentation/RCU/rculist_nulls.txt for details)
2369          */
2370         smp_wmb();
2371         atomic_set(&sk->sk_refcnt, 1);
2372         atomic_set(&sk->sk_drops, 0);
2373 }
2374 EXPORT_SYMBOL(sock_init_data);
2375 
2376 void lock_sock_nested(struct sock *sk, int subclass)
2377 {
2378         might_sleep();
2379         spin_lock_bh(&sk->sk_lock.slock);
2380         if (sk->sk_lock.owned)
2381                 __lock_sock(sk);
2382         sk->sk_lock.owned = 1;
2383         spin_unlock(&sk->sk_lock.slock);
2384         /*
2385          * The sk_lock has mutex_lock() semantics here:
2386          */
2387         mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2388         local_bh_enable();
2389 }
2390 EXPORT_SYMBOL(lock_sock_nested);
2391 
2392 void release_sock(struct sock *sk)
2393 {
2394         /*
2395          * The sk_lock has mutex_unlock() semantics:
2396          */
2397         mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2398 
2399         spin_lock_bh(&sk->sk_lock.slock);
2400         if (sk->sk_backlog.tail)
2401                 __release_sock(sk);
2402 
2403         /* Warning : release_cb() might need to release sk ownership,
2404          * ie call sock_release_ownership(sk) before us.
2405          */
2406         if (sk->sk_prot->release_cb)
2407                 sk->sk_prot->release_cb(sk);
2408 
2409         sock_release_ownership(sk);
2410         if (waitqueue_active(&sk->sk_lock.wq))
2411                 wake_up(&sk->sk_lock.wq);
2412         spin_unlock_bh(&sk->sk_lock.slock);
2413 }
2414 EXPORT_SYMBOL(release_sock);
2415 
2416 /**
2417  * lock_sock_fast - fast version of lock_sock
2418  * @sk: socket
2419  *
2420  * This version should be used for very small section, where process wont block
2421  * return false if fast path is taken
2422  *   sk_lock.slock locked, owned = 0, BH disabled
2423  * return true if slow path is taken
2424  *   sk_lock.slock unlocked, owned = 1, BH enabled
2425  */
2426 bool lock_sock_fast(struct sock *sk)
2427 {
2428         might_sleep();
2429         spin_lock_bh(&sk->sk_lock.slock);
2430 
2431         if (!sk->sk_lock.owned)
2432                 /*
2433                  * Note : We must disable BH
2434                  */
2435                 return false;
2436 
2437         __lock_sock(sk);
2438         sk->sk_lock.owned = 1;
2439         spin_unlock(&sk->sk_lock.slock);
2440         /*
2441          * The sk_lock has mutex_lock() semantics here:
2442          */
2443         mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2444         local_bh_enable();
2445         return true;
2446 }
2447 EXPORT_SYMBOL(lock_sock_fast);
2448 
2449 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2450 {
2451         struct timeval tv;
2452         if (!sock_flag(sk, SOCK_TIMESTAMP))
2453                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2454         tv = ktime_to_timeval(sk->sk_stamp);
2455         if (tv.tv_sec == -1)
2456                 return -ENOENT;
2457         if (tv.tv_sec == 0) {
2458                 sk->sk_stamp = ktime_get_real();
2459                 tv = ktime_to_timeval(sk->sk_stamp);
2460         }
2461         return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2462 }
2463 EXPORT_SYMBOL(sock_get_timestamp);
2464 
2465 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2466 {
2467         struct timespec ts;
2468         if (!sock_flag(sk, SOCK_TIMESTAMP))
2469                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2470         ts = ktime_to_timespec(sk->sk_stamp);
2471         if (ts.tv_sec == -1)
2472                 return -ENOENT;
2473         if (ts.tv_sec == 0) {
2474                 sk->sk_stamp = ktime_get_real();
2475                 ts = ktime_to_timespec(sk->sk_stamp);
2476         }
2477         return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2478 }
2479 EXPORT_SYMBOL(sock_get_timestampns);
2480 
2481 void sock_enable_timestamp(struct sock *sk, int flag)
2482 {
2483         if (!sock_flag(sk, flag)) {
2484                 unsigned long previous_flags = sk->sk_flags;
2485 
2486                 sock_set_flag(sk, flag);
2487                 /*
2488                  * we just set one of the two flags which require net
2489                  * time stamping, but time stamping might have been on
2490                  * already because of the other one
2491                  */
2492                 if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2493                         net_enable_timestamp();
2494         }
2495 }
2496 
2497 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2498                        int level, int type)
2499 {
2500         struct sock_exterr_skb *serr;
2501         struct sk_buff *skb, *skb2;
2502         int copied, err;
2503 
2504         err = -EAGAIN;
2505         skb = skb_dequeue(&sk->sk_error_queue);
2506         if (skb == NULL)
2507                 goto out;
2508 
2509         copied = skb->len;
2510         if (copied > len) {
2511                 msg->msg_flags |= MSG_TRUNC;
2512                 copied = len;
2513         }
2514         err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2515         if (err)
2516                 goto out_free_skb;
2517 
2518         sock_recv_timestamp(msg, sk, skb);
2519 
2520         serr = SKB_EXT_ERR(skb);
2521         put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2522 
2523         msg->msg_flags |= MSG_ERRQUEUE;
2524         err = copied;
2525 
2526         /* Reset and regenerate socket error */
2527         spin_lock_bh(&sk->sk_error_queue.lock);
2528         sk->sk_err = 0;
2529         if ((skb2 = skb_peek(&sk->sk_error_queue)) != NULL) {
2530                 sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
2531                 spin_unlock_bh(&sk->sk_error_queue.lock);
2532                 sk->sk_error_report(sk);
2533         } else
2534                 spin_unlock_bh(&sk->sk_error_queue.lock);
2535 
2536 out_free_skb:
2537         kfree_skb(skb);
2538 out:
2539         return err;
2540 }
2541 EXPORT_SYMBOL(sock_recv_errqueue);
2542 
2543 /*
2544  *      Get a socket option on an socket.
2545  *
2546  *      FIX: POSIX 1003.1g is very ambiguous here. It states that
2547  *      asynchronous errors should be reported by getsockopt. We assume
2548  *      this means if you specify SO_ERROR (otherwise whats the point of it).
2549  */
2550 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2551                            char __user *optval, int __user *optlen)
2552 {
2553         struct sock *sk = sock->sk;
2554 
2555         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2556 }
2557 EXPORT_SYMBOL(sock_common_getsockopt);
2558 
2559 #ifdef CONFIG_COMPAT
2560 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2561                                   char __user *optval, int __user *optlen)
2562 {
2563         struct sock *sk = sock->sk;
2564 
2565         if (sk->sk_prot->compat_getsockopt != NULL)
2566                 return sk->sk_prot->compat_getsockopt(sk, level, optname,
2567                                                       optval, optlen);
2568         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2569 }
2570 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2571 #endif
2572 
2573 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2574                         struct msghdr *msg, size_t size, int flags)
2575 {
2576         struct sock *sk = sock->sk;
2577         int addr_len = 0;
2578         int err;
2579 
2580         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2581                                    flags & ~MSG_DONTWAIT, &addr_len);
2582         if (err >= 0)
2583                 msg->msg_namelen = addr_len;
2584         return err;
2585 }
2586 EXPORT_SYMBOL(sock_common_recvmsg);
2587 
2588 /*
2589  *      Set socket options on an inet socket.
2590  */
2591 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2592                            char __user *optval, unsigned int optlen)
2593 {
2594         struct sock *sk = sock->sk;
2595 
2596         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2597 }
2598 EXPORT_SYMBOL(sock_common_setsockopt);
2599 
2600 #ifdef CONFIG_COMPAT
2601 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2602                                   char __user *optval, unsigned int optlen)
2603 {
2604         struct sock *sk = sock->sk;
2605 
2606         if (sk->sk_prot->compat_setsockopt != NULL)
2607                 return sk->sk_prot->compat_setsockopt(sk, level, optname,
2608                                                       optval, optlen);
2609         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2610 }
2611 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2612 #endif
2613 
2614 void sk_common_release(struct sock *sk)
2615 {
2616         if (sk->sk_prot->destroy)
2617                 sk->sk_prot->destroy(sk);
2618 
2619         /*
2620          * Observation: when sock_common_release is called, processes have
2621          * no access to socket. But net still has.
2622          * Step one, detach it from networking:
2623          *
2624          * A. Remove from hash tables.
2625          */
2626 
2627         sk->sk_prot->unhash(sk);
2628 
2629         /*
2630          * In this point socket cannot receive new packets, but it is possible
2631          * that some packets are in flight because some CPU runs receiver and
2632          * did hash table lookup before we unhashed socket. They will achieve
2633          * receive queue and will be purged by socket destructor.
2634          *
2635          * Also we still have packets pending on receive queue and probably,
2636          * our own packets waiting in device queues. sock_destroy will drain
2637          * receive queue, but transmitted packets will delay socket destruction
2638          * until the last reference will be released.
2639          */
2640 
2641         sock_orphan(sk);
2642 
2643         xfrm_sk_free_policy(sk);
2644 
2645         sk_refcnt_debug_release(sk);
2646 
2647         if (sk->sk_frag.page) {
2648                 put_page(sk->sk_frag.page);
2649                 sk->sk_frag.page = NULL;
2650         }
2651 
2652         sock_put(sk);
2653 }
2654 EXPORT_SYMBOL(sk_common_release);
2655 
2656 #ifdef CONFIG_PROC_FS
2657 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
2658 struct prot_inuse {
2659         int val[PROTO_INUSE_NR];
2660 };
2661 
2662 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2663 
2664 #ifdef CONFIG_NET_NS
2665 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2666 {
2667         __this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2668 }
2669 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2670 
2671 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2672 {
2673         int cpu, idx = prot->inuse_idx;
2674         int res = 0;
2675 
2676         for_each_possible_cpu(cpu)
2677                 res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2678 
2679         return res >= 0 ? res : 0;
2680 }
2681 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2682 
2683 static int __net_init sock_inuse_init_net(struct net *net)
2684 {
2685         net->core.inuse = alloc_percpu(struct prot_inuse);
2686         return net->core.inuse ? 0 : -ENOMEM;
2687 }
2688 
2689 static void __net_exit sock_inuse_exit_net(struct net *net)
2690 {
2691         free_percpu(net->core.inuse);
2692 }
2693 
2694 static struct pernet_operations net_inuse_ops = {
2695         .init = sock_inuse_init_net,
2696         .exit = sock_inuse_exit_net,
2697 };
2698 
2699 static __init int net_inuse_init(void)
2700 {
2701         if (register_pernet_subsys(&net_inuse_ops))
2702                 panic("Cannot initialize net inuse counters");
2703 
2704         return 0;
2705 }
2706 
2707 core_initcall(net_inuse_init);
2708 #else
2709 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2710 
2711 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2712 {
2713         __this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2714 }
2715 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2716 
2717 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2718 {
2719         int cpu, idx = prot->inuse_idx;
2720         int res = 0;
2721 
2722         for_each_possible_cpu(cpu)
2723                 res += per_cpu(prot_inuse, cpu).val[idx];
2724 
2725         return res >= 0 ? res : 0;
2726 }
2727 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2728 #endif
2729 
2730 static void assign_proto_idx(struct proto *prot)
2731 {
2732         prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2733 
2734         if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2735                 pr_err("PROTO_INUSE_NR exhausted\n");
2736                 return;
2737         }
2738 
2739         set_bit(prot->inuse_idx, proto_inuse_idx);
2740 }
2741 
2742 static void release_proto_idx(struct proto *prot)
2743 {
2744         if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2745                 clear_bit(prot->inuse_idx, proto_inuse_idx);
2746 }
2747 #else
2748 static inline void assign_proto_idx(struct proto *prot)
2749 {
2750 }
2751 
2752 static inline void release_proto_idx(struct proto *prot)
2753 {
2754 }
2755 #endif
2756 
2757 int proto_register(struct proto *prot, int alloc_slab)
2758 {
2759         if (alloc_slab) {
2760                 prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2761                                         SLAB_HWCACHE_ALIGN | prot->slab_flags,
2762                                         NULL);
2763 
2764                 if (prot->slab == NULL) {
2765                         pr_crit("%s: Can't create sock SLAB cache!\n",
2766                                 prot->name);
2767                         goto out;
2768                 }
2769 
2770                 if (prot->rsk_prot != NULL) {
2771                         prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2772                         if (prot->rsk_prot->slab_name == NULL)
2773                                 goto out_free_sock_slab;
2774 
2775                         prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2776                                                                  prot->rsk_prot->obj_size, 0,
2777                                                                  SLAB_HWCACHE_ALIGN, NULL);
2778 
2779                         if (prot->rsk_prot->slab == NULL) {
2780                                 pr_crit("%s: Can't create request sock SLAB cache!\n",
2781                                         prot->name);
2782                                 goto out_free_request_sock_slab_name;
2783                         }
2784                 }
2785 
2786                 if (prot->twsk_prot != NULL) {
2787                         prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2788 
2789                         if (prot->twsk_prot->twsk_slab_name == NULL)
2790                                 goto out_free_request_sock_slab;
2791 
2792                         prot->twsk_prot->twsk_slab =
2793                                 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2794                                                   prot->twsk_prot->twsk_obj_size,
2795                                                   0,
2796                                                   SLAB_HWCACHE_ALIGN |
2797                                                         prot->slab_flags,
2798                                                   NULL);
2799                         if (prot->twsk_prot->twsk_slab == NULL)
2800                                 goto out_free_timewait_sock_slab_name;
2801                 }
2802         }
2803 
2804         mutex_lock(&proto_list_mutex);
2805         list_add(&prot->node, &proto_list);
2806         assign_proto_idx(prot);
2807         mutex_unlock(&proto_list_mutex);
2808         return 0;
2809 
2810 out_free_timewait_sock_slab_name:
2811         kfree(prot->twsk_prot->twsk_slab_name);
2812 out_free_request_sock_slab:
2813         if (prot->rsk_prot && prot->rsk_prot->slab) {
2814                 kmem_cache_destroy(prot->rsk_prot->slab);
2815                 prot->rsk_prot->slab = NULL;
2816         }
2817 out_free_request_sock_slab_name:
2818         if (prot->rsk_prot)
2819                 kfree(prot->rsk_prot->slab_name);
2820 out_free_sock_slab:
2821         kmem_cache_destroy(prot->slab);
2822         prot->slab = NULL;
2823 out:
2824         return -ENOBUFS;
2825 }
2826 EXPORT_SYMBOL(proto_register);
2827 
2828 void proto_unregister(struct proto *prot)
2829 {
2830         mutex_lock(&proto_list_mutex);
2831         release_proto_idx(prot);
2832         list_del(&prot->node);
2833         mutex_unlock(&proto_list_mutex);
2834 
2835         if (prot->slab != NULL) {
2836                 kmem_cache_destroy(prot->slab);
2837                 prot->slab = NULL;
2838         }
2839 
2840         if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2841                 kmem_cache_destroy(prot->rsk_prot->slab);
2842                 kfree(prot->rsk_prot->slab_name);
2843                 prot->rsk_prot->slab = NULL;
2844         }
2845 
2846         if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2847                 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2848                 kfree(prot->twsk_prot->twsk_slab_name);
2849                 prot->twsk_prot->twsk_slab = NULL;
2850         }
2851 }
2852 EXPORT_SYMBOL(proto_unregister);
2853 
2854 #ifdef CONFIG_PROC_FS
2855 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2856         __acquires(proto_list_mutex)
2857 {
2858         mutex_lock(&proto_list_mutex);
2859         return seq_list_start_head(&proto_list, *pos);
2860 }
2861 
2862 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2863 {
2864         return seq_list_next(v, &proto_list, pos);
2865 }
2866 
2867 static void proto_seq_stop(struct seq_file *seq, void *v)
2868         __releases(proto_list_mutex)
2869 {
2870         mutex_unlock(&proto_list_mutex);
2871 }
2872 
2873 static char proto_method_implemented(const void *method)
2874 {
2875         return method == NULL ? 'n' : 'y';
2876 }
2877 static long sock_prot_memory_allocated(struct proto *proto)
2878 {
2879         return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2880 }
2881 
2882 static char *sock_prot_memory_pressure(struct proto *proto)
2883 {
2884         return proto->memory_pressure != NULL ?
2885         proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2886 }
2887 
2888 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2889 {
2890 
2891         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2892                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2893                    proto->name,
2894                    proto->obj_size,
2895                    sock_prot_inuse_get(seq_file_net(seq), proto),
2896                    sock_prot_memory_allocated(proto),
2897                    sock_prot_memory_pressure(proto),
2898                    proto->max_header,
2899                    proto->slab == NULL ? "no" : "yes",
2900                    module_name(proto->owner),
2901                    proto_method_implemented(proto->close),
2902                    proto_method_implemented(proto->connect),
2903                    proto_method_implemented(proto->disconnect),
2904                    proto_method_implemented(proto->accept),
2905                    proto_method_implemented(proto->ioctl),
2906                    proto_method_implemented(proto->init),
2907                    proto_method_implemented(proto->destroy),
2908                    proto_method_implemented(proto->shutdown),
2909                    proto_method_implemented(proto->setsockopt),
2910                    proto_method_implemented(proto->getsockopt),
2911                    proto_method_implemented(proto->sendmsg),
2912                    proto_method_implemented(proto->recvmsg),
2913                    proto_method_implemented(proto->sendpage),
2914                    proto_method_implemented(proto->bind),
2915                    proto_method_implemented(proto->backlog_rcv),
2916                    proto_method_implemented(proto->hash),
2917                    proto_method_implemented(proto->unhash),
2918                    proto_method_implemented(proto->get_port),
2919                    proto_method_implemented(proto->enter_memory_pressure));
2920 }
2921 
2922 static int proto_seq_show(struct seq_file *seq, void *v)
2923 {
2924         if (v == &proto_list)
2925                 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2926                            "protocol",
2927                            "size",
2928                            "sockets",
2929                            "memory",
2930                            "press",
2931                            "maxhdr",
2932                            "slab",
2933                            "module",
2934                            "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2935         else
2936                 proto_seq_printf(seq, list_entry(v, struct proto, node));
2937         return 0;
2938 }
2939 
2940 static const struct seq_operations proto_seq_ops = {
2941         .start  = proto_seq_start,
2942         .next   = proto_seq_next,
2943         .stop   = proto_seq_stop,
2944         .show   = proto_seq_show,
2945 };
2946 
2947 static int proto_seq_open(struct inode *inode, struct file *file)
2948 {
2949         return seq_open_net(inode, file, &proto_seq_ops,
2950                             sizeof(struct seq_net_private));
2951 }
2952 
2953 static const struct file_operations proto_seq_fops = {
2954         .owner          = THIS_MODULE,
2955         .open           = proto_seq_open,
2956         .read           = seq_read,
2957         .llseek         = seq_lseek,
2958         .release        = seq_release_net,
2959 };
2960 
2961 static __net_init int proto_init_net(struct net *net)
2962 {
2963         if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
2964                 return -ENOMEM;
2965 
2966         return 0;
2967 }
2968 
2969 static __net_exit void proto_exit_net(struct net *net)
2970 {
2971         remove_proc_entry("protocols", net->proc_net);
2972 }
2973 
2974 
2975 static __net_initdata struct pernet_operations proto_net_ops = {
2976         .init = proto_init_net,
2977         .exit = proto_exit_net,
2978 };
2979 
2980 static int __init proto_init(void)
2981 {
2982         return register_pernet_subsys(&proto_net_ops);
2983 }
2984 
2985 subsys_initcall(proto_init);
2986 
2987 #endif /* PROC_FS */
2988 

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