Version:  2.0.40 2.2.26 2.4.37 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 3.18 3.19

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

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