Version:  2.0.40 2.2.26 2.4.37 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 4.0 4.1

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 int sysctl_tstamp_allow_data __read_mostly = 1;
329 
330 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
331 EXPORT_SYMBOL_GPL(memalloc_socks);
332 
333 /**
334  * sk_set_memalloc - sets %SOCK_MEMALLOC
335  * @sk: socket to set it on
336  *
337  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
338  * It's the responsibility of the admin to adjust min_free_kbytes
339  * to meet the requirements
340  */
341 void sk_set_memalloc(struct sock *sk)
342 {
343         sock_set_flag(sk, SOCK_MEMALLOC);
344         sk->sk_allocation |= __GFP_MEMALLOC;
345         static_key_slow_inc(&memalloc_socks);
346 }
347 EXPORT_SYMBOL_GPL(sk_set_memalloc);
348 
349 void sk_clear_memalloc(struct sock *sk)
350 {
351         sock_reset_flag(sk, SOCK_MEMALLOC);
352         sk->sk_allocation &= ~__GFP_MEMALLOC;
353         static_key_slow_dec(&memalloc_socks);
354 
355         /*
356          * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
357          * progress of swapping. SOCK_MEMALLOC may be cleared while
358          * it has rmem allocations due to the last swapfile being deactivated
359          * but there is a risk that the socket is unusable due to exceeding
360          * the rmem limits. Reclaim the reserves and obey rmem limits again.
361          */
362         sk_mem_reclaim(sk);
363 }
364 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
365 
366 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
367 {
368         int ret;
369         unsigned long pflags = current->flags;
370 
371         /* these should have been dropped before queueing */
372         BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
373 
374         current->flags |= PF_MEMALLOC;
375         ret = sk->sk_backlog_rcv(sk, skb);
376         tsk_restore_flags(current, pflags, PF_MEMALLOC);
377 
378         return ret;
379 }
380 EXPORT_SYMBOL(__sk_backlog_rcv);
381 
382 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
383 {
384         struct timeval tv;
385 
386         if (optlen < sizeof(tv))
387                 return -EINVAL;
388         if (copy_from_user(&tv, optval, sizeof(tv)))
389                 return -EFAULT;
390         if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
391                 return -EDOM;
392 
393         if (tv.tv_sec < 0) {
394                 static int warned __read_mostly;
395 
396                 *timeo_p = 0;
397                 if (warned < 10 && net_ratelimit()) {
398                         warned++;
399                         pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
400                                 __func__, current->comm, task_pid_nr(current));
401                 }
402                 return 0;
403         }
404         *timeo_p = MAX_SCHEDULE_TIMEOUT;
405         if (tv.tv_sec == 0 && tv.tv_usec == 0)
406                 return 0;
407         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
408                 *timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
409         return 0;
410 }
411 
412 static void sock_warn_obsolete_bsdism(const char *name)
413 {
414         static int warned;
415         static char warncomm[TASK_COMM_LEN];
416         if (strcmp(warncomm, current->comm) && warned < 5) {
417                 strcpy(warncomm,  current->comm);
418                 pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
419                         warncomm, name);
420                 warned++;
421         }
422 }
423 
424 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
425 
426 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
427 {
428         if (sk->sk_flags & flags) {
429                 sk->sk_flags &= ~flags;
430                 if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
431                         net_disable_timestamp();
432         }
433 }
434 
435 
436 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
437 {
438         int err;
439         unsigned long flags;
440         struct sk_buff_head *list = &sk->sk_receive_queue;
441 
442         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
443                 atomic_inc(&sk->sk_drops);
444                 trace_sock_rcvqueue_full(sk, skb);
445                 return -ENOMEM;
446         }
447 
448         err = sk_filter(sk, skb);
449         if (err)
450                 return err;
451 
452         if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
453                 atomic_inc(&sk->sk_drops);
454                 return -ENOBUFS;
455         }
456 
457         skb->dev = NULL;
458         skb_set_owner_r(skb, sk);
459 
460         /* we escape from rcu protected region, make sure we dont leak
461          * a norefcounted dst
462          */
463         skb_dst_force(skb);
464 
465         spin_lock_irqsave(&list->lock, flags);
466         sock_skb_set_dropcount(sk, skb);
467         __skb_queue_tail(list, skb);
468         spin_unlock_irqrestore(&list->lock, flags);
469 
470         if (!sock_flag(sk, SOCK_DEAD))
471                 sk->sk_data_ready(sk);
472         return 0;
473 }
474 EXPORT_SYMBOL(sock_queue_rcv_skb);
475 
476 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
477 {
478         int rc = NET_RX_SUCCESS;
479 
480         if (sk_filter(sk, skb))
481                 goto discard_and_relse;
482 
483         skb->dev = NULL;
484 
485         if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
486                 atomic_inc(&sk->sk_drops);
487                 goto discard_and_relse;
488         }
489         if (nested)
490                 bh_lock_sock_nested(sk);
491         else
492                 bh_lock_sock(sk);
493         if (!sock_owned_by_user(sk)) {
494                 /*
495                  * trylock + unlock semantics:
496                  */
497                 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
498 
499                 rc = sk_backlog_rcv(sk, skb);
500 
501                 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
502         } else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
503                 bh_unlock_sock(sk);
504                 atomic_inc(&sk->sk_drops);
505                 goto discard_and_relse;
506         }
507 
508         bh_unlock_sock(sk);
509 out:
510         sock_put(sk);
511         return rc;
512 discard_and_relse:
513         kfree_skb(skb);
514         goto out;
515 }
516 EXPORT_SYMBOL(sk_receive_skb);
517 
518 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
519 {
520         struct dst_entry *dst = __sk_dst_get(sk);
521 
522         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
523                 sk_tx_queue_clear(sk);
524                 RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
525                 dst_release(dst);
526                 return NULL;
527         }
528 
529         return dst;
530 }
531 EXPORT_SYMBOL(__sk_dst_check);
532 
533 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
534 {
535         struct dst_entry *dst = sk_dst_get(sk);
536 
537         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
538                 sk_dst_reset(sk);
539                 dst_release(dst);
540                 return NULL;
541         }
542 
543         return dst;
544 }
545 EXPORT_SYMBOL(sk_dst_check);
546 
547 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
548                                 int optlen)
549 {
550         int ret = -ENOPROTOOPT;
551 #ifdef CONFIG_NETDEVICES
552         struct net *net = sock_net(sk);
553         char devname[IFNAMSIZ];
554         int index;
555 
556         /* Sorry... */
557         ret = -EPERM;
558         if (!ns_capable(net->user_ns, CAP_NET_RAW))
559                 goto out;
560 
561         ret = -EINVAL;
562         if (optlen < 0)
563                 goto out;
564 
565         /* Bind this socket to a particular device like "eth0",
566          * as specified in the passed interface name. If the
567          * name is "" or the option length is zero the socket
568          * is not bound.
569          */
570         if (optlen > IFNAMSIZ - 1)
571                 optlen = IFNAMSIZ - 1;
572         memset(devname, 0, sizeof(devname));
573 
574         ret = -EFAULT;
575         if (copy_from_user(devname, optval, optlen))
576                 goto out;
577 
578         index = 0;
579         if (devname[0] != '\0') {
580                 struct net_device *dev;
581 
582                 rcu_read_lock();
583                 dev = dev_get_by_name_rcu(net, devname);
584                 if (dev)
585                         index = dev->ifindex;
586                 rcu_read_unlock();
587                 ret = -ENODEV;
588                 if (!dev)
589                         goto out;
590         }
591 
592         lock_sock(sk);
593         sk->sk_bound_dev_if = index;
594         sk_dst_reset(sk);
595         release_sock(sk);
596 
597         ret = 0;
598 
599 out:
600 #endif
601 
602         return ret;
603 }
604 
605 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
606                                 int __user *optlen, int len)
607 {
608         int ret = -ENOPROTOOPT;
609 #ifdef CONFIG_NETDEVICES
610         struct net *net = sock_net(sk);
611         char devname[IFNAMSIZ];
612 
613         if (sk->sk_bound_dev_if == 0) {
614                 len = 0;
615                 goto zero;
616         }
617 
618         ret = -EINVAL;
619         if (len < IFNAMSIZ)
620                 goto out;
621 
622         ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
623         if (ret)
624                 goto out;
625 
626         len = strlen(devname) + 1;
627 
628         ret = -EFAULT;
629         if (copy_to_user(optval, devname, len))
630                 goto out;
631 
632 zero:
633         ret = -EFAULT;
634         if (put_user(len, optlen))
635                 goto out;
636 
637         ret = 0;
638 
639 out:
640 #endif
641 
642         return ret;
643 }
644 
645 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
646 {
647         if (valbool)
648                 sock_set_flag(sk, bit);
649         else
650                 sock_reset_flag(sk, bit);
651 }
652 
653 bool sk_mc_loop(struct sock *sk)
654 {
655         if (dev_recursion_level())
656                 return false;
657         if (!sk)
658                 return true;
659         switch (sk->sk_family) {
660         case AF_INET:
661                 return inet_sk(sk)->mc_loop;
662 #if IS_ENABLED(CONFIG_IPV6)
663         case AF_INET6:
664                 return inet6_sk(sk)->mc_loop;
665 #endif
666         }
667         WARN_ON(1);
668         return true;
669 }
670 EXPORT_SYMBOL(sk_mc_loop);
671 
672 /*
673  *      This is meant for all protocols to use and covers goings on
674  *      at the socket level. Everything here is generic.
675  */
676 
677 int sock_setsockopt(struct socket *sock, int level, int optname,
678                     char __user *optval, unsigned int optlen)
679 {
680         struct sock *sk = sock->sk;
681         int val;
682         int valbool;
683         struct linger ling;
684         int ret = 0;
685 
686         /*
687          *      Options without arguments
688          */
689 
690         if (optname == SO_BINDTODEVICE)
691                 return sock_setbindtodevice(sk, optval, optlen);
692 
693         if (optlen < sizeof(int))
694                 return -EINVAL;
695 
696         if (get_user(val, (int __user *)optval))
697                 return -EFAULT;
698 
699         valbool = val ? 1 : 0;
700 
701         lock_sock(sk);
702 
703         switch (optname) {
704         case SO_DEBUG:
705                 if (val && !capable(CAP_NET_ADMIN))
706                         ret = -EACCES;
707                 else
708                         sock_valbool_flag(sk, SOCK_DBG, valbool);
709                 break;
710         case SO_REUSEADDR:
711                 sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
712                 break;
713         case SO_REUSEPORT:
714                 sk->sk_reuseport = valbool;
715                 break;
716         case SO_TYPE:
717         case SO_PROTOCOL:
718         case SO_DOMAIN:
719         case SO_ERROR:
720                 ret = -ENOPROTOOPT;
721                 break;
722         case SO_DONTROUTE:
723                 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
724                 break;
725         case SO_BROADCAST:
726                 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
727                 break;
728         case SO_SNDBUF:
729                 /* Don't error on this BSD doesn't and if you think
730                  * about it this is right. Otherwise apps have to
731                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
732                  * are treated in BSD as hints
733                  */
734                 val = min_t(u32, val, sysctl_wmem_max);
735 set_sndbuf:
736                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
737                 sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
738                 /* Wake up sending tasks if we upped the value. */
739                 sk->sk_write_space(sk);
740                 break;
741 
742         case SO_SNDBUFFORCE:
743                 if (!capable(CAP_NET_ADMIN)) {
744                         ret = -EPERM;
745                         break;
746                 }
747                 goto set_sndbuf;
748 
749         case SO_RCVBUF:
750                 /* Don't error on this BSD doesn't and if you think
751                  * about it this is right. Otherwise apps have to
752                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
753                  * are treated in BSD as hints
754                  */
755                 val = min_t(u32, val, sysctl_rmem_max);
756 set_rcvbuf:
757                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
758                 /*
759                  * We double it on the way in to account for
760                  * "struct sk_buff" etc. overhead.   Applications
761                  * assume that the SO_RCVBUF setting they make will
762                  * allow that much actual data to be received on that
763                  * socket.
764                  *
765                  * Applications are unaware that "struct sk_buff" and
766                  * other overheads allocate from the receive buffer
767                  * during socket buffer allocation.
768                  *
769                  * And after considering the possible alternatives,
770                  * returning the value we actually used in getsockopt
771                  * is the most desirable behavior.
772                  */
773                 sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
774                 break;
775 
776         case SO_RCVBUFFORCE:
777                 if (!capable(CAP_NET_ADMIN)) {
778                         ret = -EPERM;
779                         break;
780                 }
781                 goto set_rcvbuf;
782 
783         case SO_KEEPALIVE:
784 #ifdef CONFIG_INET
785                 if (sk->sk_protocol == IPPROTO_TCP &&
786                     sk->sk_type == SOCK_STREAM)
787                         tcp_set_keepalive(sk, valbool);
788 #endif
789                 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
790                 break;
791 
792         case SO_OOBINLINE:
793                 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
794                 break;
795 
796         case SO_NO_CHECK:
797                 sk->sk_no_check_tx = valbool;
798                 break;
799 
800         case SO_PRIORITY:
801                 if ((val >= 0 && val <= 6) ||
802                     ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
803                         sk->sk_priority = val;
804                 else
805                         ret = -EPERM;
806                 break;
807 
808         case SO_LINGER:
809                 if (optlen < sizeof(ling)) {
810                         ret = -EINVAL;  /* 1003.1g */
811                         break;
812                 }
813                 if (copy_from_user(&ling, optval, sizeof(ling))) {
814                         ret = -EFAULT;
815                         break;
816                 }
817                 if (!ling.l_onoff)
818                         sock_reset_flag(sk, SOCK_LINGER);
819                 else {
820 #if (BITS_PER_LONG == 32)
821                         if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
822                                 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
823                         else
824 #endif
825                                 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
826                         sock_set_flag(sk, SOCK_LINGER);
827                 }
828                 break;
829 
830         case SO_BSDCOMPAT:
831                 sock_warn_obsolete_bsdism("setsockopt");
832                 break;
833 
834         case SO_PASSCRED:
835                 if (valbool)
836                         set_bit(SOCK_PASSCRED, &sock->flags);
837                 else
838                         clear_bit(SOCK_PASSCRED, &sock->flags);
839                 break;
840 
841         case SO_TIMESTAMP:
842         case SO_TIMESTAMPNS:
843                 if (valbool)  {
844                         if (optname == SO_TIMESTAMP)
845                                 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
846                         else
847                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
848                         sock_set_flag(sk, SOCK_RCVTSTAMP);
849                         sock_enable_timestamp(sk, SOCK_TIMESTAMP);
850                 } else {
851                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
852                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
853                 }
854                 break;
855 
856         case SO_TIMESTAMPING:
857                 if (val & ~SOF_TIMESTAMPING_MASK) {
858                         ret = -EINVAL;
859                         break;
860                 }
861 
862                 if (val & SOF_TIMESTAMPING_OPT_ID &&
863                     !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
864                         if (sk->sk_protocol == IPPROTO_TCP) {
865                                 if (sk->sk_state != TCP_ESTABLISHED) {
866                                         ret = -EINVAL;
867                                         break;
868                                 }
869                                 sk->sk_tskey = tcp_sk(sk)->snd_una;
870                         } else {
871                                 sk->sk_tskey = 0;
872                         }
873                 }
874                 sk->sk_tsflags = val;
875                 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
876                         sock_enable_timestamp(sk,
877                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
878                 else
879                         sock_disable_timestamp(sk,
880                                                (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
881                 break;
882 
883         case SO_RCVLOWAT:
884                 if (val < 0)
885                         val = INT_MAX;
886                 sk->sk_rcvlowat = val ? : 1;
887                 break;
888 
889         case SO_RCVTIMEO:
890                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
891                 break;
892 
893         case SO_SNDTIMEO:
894                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
895                 break;
896 
897         case SO_ATTACH_FILTER:
898                 ret = -EINVAL;
899                 if (optlen == sizeof(struct sock_fprog)) {
900                         struct sock_fprog fprog;
901 
902                         ret = -EFAULT;
903                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
904                                 break;
905 
906                         ret = sk_attach_filter(&fprog, sk);
907                 }
908                 break;
909 
910         case SO_ATTACH_BPF:
911                 ret = -EINVAL;
912                 if (optlen == sizeof(u32)) {
913                         u32 ufd;
914 
915                         ret = -EFAULT;
916                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
917                                 break;
918 
919                         ret = sk_attach_bpf(ufd, sk);
920                 }
921                 break;
922 
923         case SO_DETACH_FILTER:
924                 ret = sk_detach_filter(sk);
925                 break;
926 
927         case SO_LOCK_FILTER:
928                 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
929                         ret = -EPERM;
930                 else
931                         sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
932                 break;
933 
934         case SO_PASSSEC:
935                 if (valbool)
936                         set_bit(SOCK_PASSSEC, &sock->flags);
937                 else
938                         clear_bit(SOCK_PASSSEC, &sock->flags);
939                 break;
940         case SO_MARK:
941                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
942                         ret = -EPERM;
943                 else
944                         sk->sk_mark = val;
945                 break;
946 
947         case SO_RXQ_OVFL:
948                 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
949                 break;
950 
951         case SO_WIFI_STATUS:
952                 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
953                 break;
954 
955         case SO_PEEK_OFF:
956                 if (sock->ops->set_peek_off)
957                         ret = sock->ops->set_peek_off(sk, val);
958                 else
959                         ret = -EOPNOTSUPP;
960                 break;
961 
962         case SO_NOFCS:
963                 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
964                 break;
965 
966         case SO_SELECT_ERR_QUEUE:
967                 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
968                 break;
969 
970 #ifdef CONFIG_NET_RX_BUSY_POLL
971         case SO_BUSY_POLL:
972                 /* allow unprivileged users to decrease the value */
973                 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
974                         ret = -EPERM;
975                 else {
976                         if (val < 0)
977                                 ret = -EINVAL;
978                         else
979                                 sk->sk_ll_usec = val;
980                 }
981                 break;
982 #endif
983 
984         case SO_MAX_PACING_RATE:
985                 sk->sk_max_pacing_rate = val;
986                 sk->sk_pacing_rate = min(sk->sk_pacing_rate,
987                                          sk->sk_max_pacing_rate);
988                 break;
989 
990         default:
991                 ret = -ENOPROTOOPT;
992                 break;
993         }
994         release_sock(sk);
995         return ret;
996 }
997 EXPORT_SYMBOL(sock_setsockopt);
998 
999 
1000 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1001                           struct ucred *ucred)
1002 {
1003         ucred->pid = pid_vnr(pid);
1004         ucred->uid = ucred->gid = -1;
1005         if (cred) {
1006                 struct user_namespace *current_ns = current_user_ns();
1007 
1008                 ucred->uid = from_kuid_munged(current_ns, cred->euid);
1009                 ucred->gid = from_kgid_munged(current_ns, cred->egid);
1010         }
1011 }
1012 
1013 int sock_getsockopt(struct socket *sock, int level, int optname,
1014                     char __user *optval, int __user *optlen)
1015 {
1016         struct sock *sk = sock->sk;
1017 
1018         union {
1019                 int val;
1020                 struct linger ling;
1021                 struct timeval tm;
1022         } v;
1023 
1024         int lv = sizeof(int);
1025         int len;
1026 
1027         if (get_user(len, optlen))
1028                 return -EFAULT;
1029         if (len < 0)
1030                 return -EINVAL;
1031 
1032         memset(&v, 0, sizeof(v));
1033 
1034         switch (optname) {
1035         case SO_DEBUG:
1036                 v.val = sock_flag(sk, SOCK_DBG);
1037                 break;
1038 
1039         case SO_DONTROUTE:
1040                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
1041                 break;
1042 
1043         case SO_BROADCAST:
1044                 v.val = sock_flag(sk, SOCK_BROADCAST);
1045                 break;
1046 
1047         case SO_SNDBUF:
1048                 v.val = sk->sk_sndbuf;
1049                 break;
1050 
1051         case SO_RCVBUF:
1052                 v.val = sk->sk_rcvbuf;
1053                 break;
1054 
1055         case SO_REUSEADDR:
1056                 v.val = sk->sk_reuse;
1057                 break;
1058 
1059         case SO_REUSEPORT:
1060                 v.val = sk->sk_reuseport;
1061                 break;
1062 
1063         case SO_KEEPALIVE:
1064                 v.val = sock_flag(sk, SOCK_KEEPOPEN);
1065                 break;
1066 
1067         case SO_TYPE:
1068                 v.val = sk->sk_type;
1069                 break;
1070 
1071         case SO_PROTOCOL:
1072                 v.val = sk->sk_protocol;
1073                 break;
1074 
1075         case SO_DOMAIN:
1076                 v.val = sk->sk_family;
1077                 break;
1078 
1079         case SO_ERROR:
1080                 v.val = -sock_error(sk);
1081                 if (v.val == 0)
1082                         v.val = xchg(&sk->sk_err_soft, 0);
1083                 break;
1084 
1085         case SO_OOBINLINE:
1086                 v.val = sock_flag(sk, SOCK_URGINLINE);
1087                 break;
1088 
1089         case SO_NO_CHECK:
1090                 v.val = sk->sk_no_check_tx;
1091                 break;
1092 
1093         case SO_PRIORITY:
1094                 v.val = sk->sk_priority;
1095                 break;
1096 
1097         case SO_LINGER:
1098                 lv              = sizeof(v.ling);
1099                 v.ling.l_onoff  = sock_flag(sk, SOCK_LINGER);
1100                 v.ling.l_linger = sk->sk_lingertime / HZ;
1101                 break;
1102 
1103         case SO_BSDCOMPAT:
1104                 sock_warn_obsolete_bsdism("getsockopt");
1105                 break;
1106 
1107         case SO_TIMESTAMP:
1108                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1109                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1110                 break;
1111 
1112         case SO_TIMESTAMPNS:
1113                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1114                 break;
1115 
1116         case SO_TIMESTAMPING:
1117                 v.val = sk->sk_tsflags;
1118                 break;
1119 
1120         case SO_RCVTIMEO:
1121                 lv = sizeof(struct timeval);
1122                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1123                         v.tm.tv_sec = 0;
1124                         v.tm.tv_usec = 0;
1125                 } else {
1126                         v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1127                         v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1128                 }
1129                 break;
1130 
1131         case SO_SNDTIMEO:
1132                 lv = sizeof(struct timeval);
1133                 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1134                         v.tm.tv_sec = 0;
1135                         v.tm.tv_usec = 0;
1136                 } else {
1137                         v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1138                         v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1139                 }
1140                 break;
1141 
1142         case SO_RCVLOWAT:
1143                 v.val = sk->sk_rcvlowat;
1144                 break;
1145 
1146         case SO_SNDLOWAT:
1147                 v.val = 1;
1148                 break;
1149 
1150         case SO_PASSCRED:
1151                 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1152                 break;
1153 
1154         case SO_PEERCRED:
1155         {
1156                 struct ucred peercred;
1157                 if (len > sizeof(peercred))
1158                         len = sizeof(peercred);
1159                 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1160                 if (copy_to_user(optval, &peercred, len))
1161                         return -EFAULT;
1162                 goto lenout;
1163         }
1164 
1165         case SO_PEERNAME:
1166         {
1167                 char address[128];
1168 
1169                 if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1170                         return -ENOTCONN;
1171                 if (lv < len)
1172                         return -EINVAL;
1173                 if (copy_to_user(optval, address, len))
1174                         return -EFAULT;
1175                 goto lenout;
1176         }
1177 
1178         /* Dubious BSD thing... Probably nobody even uses it, but
1179          * the UNIX standard wants it for whatever reason... -DaveM
1180          */
1181         case SO_ACCEPTCONN:
1182                 v.val = sk->sk_state == TCP_LISTEN;
1183                 break;
1184 
1185         case SO_PASSSEC:
1186                 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1187                 break;
1188 
1189         case SO_PEERSEC:
1190                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1191 
1192         case SO_MARK:
1193                 v.val = sk->sk_mark;
1194                 break;
1195 
1196         case SO_RXQ_OVFL:
1197                 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1198                 break;
1199 
1200         case SO_WIFI_STATUS:
1201                 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1202                 break;
1203 
1204         case SO_PEEK_OFF:
1205                 if (!sock->ops->set_peek_off)
1206                         return -EOPNOTSUPP;
1207 
1208                 v.val = sk->sk_peek_off;
1209                 break;
1210         case SO_NOFCS:
1211                 v.val = sock_flag(sk, SOCK_NOFCS);
1212                 break;
1213 
1214         case SO_BINDTODEVICE:
1215                 return sock_getbindtodevice(sk, optval, optlen, len);
1216 
1217         case SO_GET_FILTER:
1218                 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1219                 if (len < 0)
1220                         return len;
1221 
1222                 goto lenout;
1223 
1224         case SO_LOCK_FILTER:
1225                 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1226                 break;
1227 
1228         case SO_BPF_EXTENSIONS:
1229                 v.val = bpf_tell_extensions();
1230                 break;
1231 
1232         case SO_SELECT_ERR_QUEUE:
1233                 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1234                 break;
1235 
1236 #ifdef CONFIG_NET_RX_BUSY_POLL
1237         case SO_BUSY_POLL:
1238                 v.val = sk->sk_ll_usec;
1239                 break;
1240 #endif
1241 
1242         case SO_MAX_PACING_RATE:
1243                 v.val = sk->sk_max_pacing_rate;
1244                 break;
1245 
1246         case SO_INCOMING_CPU:
1247                 v.val = sk->sk_incoming_cpu;
1248                 break;
1249 
1250         default:
1251                 /* We implement the SO_SNDLOWAT etc to not be settable
1252                  * (1003.1g 7).
1253                  */
1254                 return -ENOPROTOOPT;
1255         }
1256 
1257         if (len > lv)
1258                 len = lv;
1259         if (copy_to_user(optval, &v, len))
1260                 return -EFAULT;
1261 lenout:
1262         if (put_user(len, optlen))
1263                 return -EFAULT;
1264         return 0;
1265 }
1266 
1267 /*
1268  * Initialize an sk_lock.
1269  *
1270  * (We also register the sk_lock with the lock validator.)
1271  */
1272 static inline void sock_lock_init(struct sock *sk)
1273 {
1274         sock_lock_init_class_and_name(sk,
1275                         af_family_slock_key_strings[sk->sk_family],
1276                         af_family_slock_keys + sk->sk_family,
1277                         af_family_key_strings[sk->sk_family],
1278                         af_family_keys + sk->sk_family);
1279 }
1280 
1281 /*
1282  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1283  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1284  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1285  */
1286 static void sock_copy(struct sock *nsk, const struct sock *osk)
1287 {
1288 #ifdef CONFIG_SECURITY_NETWORK
1289         void *sptr = nsk->sk_security;
1290 #endif
1291         memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1292 
1293         memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1294                osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1295 
1296 #ifdef CONFIG_SECURITY_NETWORK
1297         nsk->sk_security = sptr;
1298         security_sk_clone(osk, nsk);
1299 #endif
1300 }
1301 
1302 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1303 {
1304         unsigned long nulls1, nulls2;
1305 
1306         nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1307         nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1308         if (nulls1 > nulls2)
1309                 swap(nulls1, nulls2);
1310 
1311         if (nulls1 != 0)
1312                 memset((char *)sk, 0, nulls1);
1313         memset((char *)sk + nulls1 + sizeof(void *), 0,
1314                nulls2 - nulls1 - sizeof(void *));
1315         memset((char *)sk + nulls2 + sizeof(void *), 0,
1316                size - nulls2 - sizeof(void *));
1317 }
1318 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1319 
1320 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1321                 int family)
1322 {
1323         struct sock *sk;
1324         struct kmem_cache *slab;
1325 
1326         slab = prot->slab;
1327         if (slab != NULL) {
1328                 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1329                 if (!sk)
1330                         return sk;
1331                 if (priority & __GFP_ZERO) {
1332                         if (prot->clear_sk)
1333                                 prot->clear_sk(sk, prot->obj_size);
1334                         else
1335                                 sk_prot_clear_nulls(sk, prot->obj_size);
1336                 }
1337         } else
1338                 sk = kmalloc(prot->obj_size, priority);
1339 
1340         if (sk != NULL) {
1341                 kmemcheck_annotate_bitfield(sk, flags);
1342 
1343                 if (security_sk_alloc(sk, family, priority))
1344                         goto out_free;
1345 
1346                 if (!try_module_get(prot->owner))
1347                         goto out_free_sec;
1348                 sk_tx_queue_clear(sk);
1349         }
1350 
1351         return sk;
1352 
1353 out_free_sec:
1354         security_sk_free(sk);
1355 out_free:
1356         if (slab != NULL)
1357                 kmem_cache_free(slab, sk);
1358         else
1359                 kfree(sk);
1360         return NULL;
1361 }
1362 
1363 static void sk_prot_free(struct proto *prot, struct sock *sk)
1364 {
1365         struct kmem_cache *slab;
1366         struct module *owner;
1367 
1368         owner = prot->owner;
1369         slab = prot->slab;
1370 
1371         security_sk_free(sk);
1372         if (slab != NULL)
1373                 kmem_cache_free(slab, sk);
1374         else
1375                 kfree(sk);
1376         module_put(owner);
1377 }
1378 
1379 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
1380 void sock_update_netprioidx(struct sock *sk)
1381 {
1382         if (in_interrupt())
1383                 return;
1384 
1385         sk->sk_cgrp_prioidx = task_netprioidx(current);
1386 }
1387 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1388 #endif
1389 
1390 /**
1391  *      sk_alloc - All socket objects are allocated here
1392  *      @net: the applicable net namespace
1393  *      @family: protocol family
1394  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1395  *      @prot: struct proto associated with this new sock instance
1396  */
1397 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1398                       struct proto *prot)
1399 {
1400         struct sock *sk;
1401 
1402         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1403         if (sk) {
1404                 sk->sk_family = family;
1405                 /*
1406                  * See comment in struct sock definition to understand
1407                  * why we need sk_prot_creator -acme
1408                  */
1409                 sk->sk_prot = sk->sk_prot_creator = prot;
1410                 sock_lock_init(sk);
1411                 sock_net_set(sk, get_net(net));
1412                 atomic_set(&sk->sk_wmem_alloc, 1);
1413 
1414                 sock_update_classid(sk);
1415                 sock_update_netprioidx(sk);
1416         }
1417 
1418         return sk;
1419 }
1420 EXPORT_SYMBOL(sk_alloc);
1421 
1422 static void __sk_free(struct sock *sk)
1423 {
1424         struct sk_filter *filter;
1425 
1426         if (sk->sk_destruct)
1427                 sk->sk_destruct(sk);
1428 
1429         filter = rcu_dereference_check(sk->sk_filter,
1430                                        atomic_read(&sk->sk_wmem_alloc) == 0);
1431         if (filter) {
1432                 sk_filter_uncharge(sk, filter);
1433                 RCU_INIT_POINTER(sk->sk_filter, NULL);
1434         }
1435 
1436         sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1437 
1438         if (atomic_read(&sk->sk_omem_alloc))
1439                 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1440                          __func__, atomic_read(&sk->sk_omem_alloc));
1441 
1442         if (sk->sk_peer_cred)
1443                 put_cred(sk->sk_peer_cred);
1444         put_pid(sk->sk_peer_pid);
1445         put_net(sock_net(sk));
1446         sk_prot_free(sk->sk_prot_creator, sk);
1447 }
1448 
1449 void sk_free(struct sock *sk)
1450 {
1451         /*
1452          * We subtract one from sk_wmem_alloc and can know if
1453          * some packets are still in some tx queue.
1454          * If not null, sock_wfree() will call __sk_free(sk) later
1455          */
1456         if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1457                 __sk_free(sk);
1458 }
1459 EXPORT_SYMBOL(sk_free);
1460 
1461 /*
1462  * Last sock_put should drop reference to sk->sk_net. It has already
1463  * been dropped in sk_change_net. Taking reference to stopping namespace
1464  * is not an option.
1465  * Take reference to a socket to remove it from hash _alive_ and after that
1466  * destroy it in the context of init_net.
1467  */
1468 void sk_release_kernel(struct sock *sk)
1469 {
1470         if (sk == NULL || sk->sk_socket == NULL)
1471                 return;
1472 
1473         sock_hold(sk);
1474         sock_release(sk->sk_socket);
1475         sock_net_set(sk, get_net(&init_net));
1476         sock_put(sk);
1477 }
1478 EXPORT_SYMBOL(sk_release_kernel);
1479 
1480 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1481 {
1482         if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1483                 sock_update_memcg(newsk);
1484 }
1485 
1486 /**
1487  *      sk_clone_lock - clone a socket, and lock its clone
1488  *      @sk: the socket to clone
1489  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1490  *
1491  *      Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1492  */
1493 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1494 {
1495         struct sock *newsk;
1496         bool is_charged = true;
1497 
1498         newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1499         if (newsk != NULL) {
1500                 struct sk_filter *filter;
1501 
1502                 sock_copy(newsk, sk);
1503 
1504                 /* SANITY */
1505                 get_net(sock_net(newsk));
1506                 sk_node_init(&newsk->sk_node);
1507                 sock_lock_init(newsk);
1508                 bh_lock_sock(newsk);
1509                 newsk->sk_backlog.head  = newsk->sk_backlog.tail = NULL;
1510                 newsk->sk_backlog.len = 0;
1511 
1512                 atomic_set(&newsk->sk_rmem_alloc, 0);
1513                 /*
1514                  * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1515                  */
1516                 atomic_set(&newsk->sk_wmem_alloc, 1);
1517                 atomic_set(&newsk->sk_omem_alloc, 0);
1518                 skb_queue_head_init(&newsk->sk_receive_queue);
1519                 skb_queue_head_init(&newsk->sk_write_queue);
1520 
1521                 spin_lock_init(&newsk->sk_dst_lock);
1522                 rwlock_init(&newsk->sk_callback_lock);
1523                 lockdep_set_class_and_name(&newsk->sk_callback_lock,
1524                                 af_callback_keys + newsk->sk_family,
1525                                 af_family_clock_key_strings[newsk->sk_family]);
1526 
1527                 newsk->sk_dst_cache     = NULL;
1528                 newsk->sk_wmem_queued   = 0;
1529                 newsk->sk_forward_alloc = 0;
1530                 newsk->sk_send_head     = NULL;
1531                 newsk->sk_userlocks     = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1532 
1533                 sock_reset_flag(newsk, SOCK_DONE);
1534                 skb_queue_head_init(&newsk->sk_error_queue);
1535 
1536                 filter = rcu_dereference_protected(newsk->sk_filter, 1);
1537                 if (filter != NULL)
1538                         /* though it's an empty new sock, the charging may fail
1539                          * if sysctl_optmem_max was changed between creation of
1540                          * original socket and cloning
1541                          */
1542                         is_charged = sk_filter_charge(newsk, filter);
1543 
1544                 if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk))) {
1545                         /* It is still raw copy of parent, so invalidate
1546                          * destructor and make plain sk_free() */
1547                         newsk->sk_destruct = NULL;
1548                         bh_unlock_sock(newsk);
1549                         sk_free(newsk);
1550                         newsk = NULL;
1551                         goto out;
1552                 }
1553 
1554                 newsk->sk_err      = 0;
1555                 newsk->sk_priority = 0;
1556                 newsk->sk_incoming_cpu = raw_smp_processor_id();
1557                 atomic64_set(&newsk->sk_cookie, 0);
1558                 /*
1559                  * Before updating sk_refcnt, we must commit prior changes to memory
1560                  * (Documentation/RCU/rculist_nulls.txt for details)
1561                  */
1562                 smp_wmb();
1563                 atomic_set(&newsk->sk_refcnt, 2);
1564 
1565                 /*
1566                  * Increment the counter in the same struct proto as the master
1567                  * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1568                  * is the same as sk->sk_prot->socks, as this field was copied
1569                  * with memcpy).
1570                  *
1571                  * This _changes_ the previous behaviour, where
1572                  * tcp_create_openreq_child always was incrementing the
1573                  * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1574                  * to be taken into account in all callers. -acme
1575                  */
1576                 sk_refcnt_debug_inc(newsk);
1577                 sk_set_socket(newsk, NULL);
1578                 newsk->sk_wq = NULL;
1579 
1580                 sk_update_clone(sk, newsk);
1581 
1582                 if (newsk->sk_prot->sockets_allocated)
1583                         sk_sockets_allocated_inc(newsk);
1584 
1585                 if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1586                         net_enable_timestamp();
1587         }
1588 out:
1589         return newsk;
1590 }
1591 EXPORT_SYMBOL_GPL(sk_clone_lock);
1592 
1593 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1594 {
1595         __sk_dst_set(sk, dst);
1596         sk->sk_route_caps = dst->dev->features;
1597         if (sk->sk_route_caps & NETIF_F_GSO)
1598                 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1599         sk->sk_route_caps &= ~sk->sk_route_nocaps;
1600         if (sk_can_gso(sk)) {
1601                 if (dst->header_len) {
1602                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1603                 } else {
1604                         sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1605                         sk->sk_gso_max_size = dst->dev->gso_max_size;
1606                         sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1607                 }
1608         }
1609 }
1610 EXPORT_SYMBOL_GPL(sk_setup_caps);
1611 
1612 /*
1613  *      Simple resource managers for sockets.
1614  */
1615 
1616 
1617 /*
1618  * Write buffer destructor automatically called from kfree_skb.
1619  */
1620 void sock_wfree(struct sk_buff *skb)
1621 {
1622         struct sock *sk = skb->sk;
1623         unsigned int len = skb->truesize;
1624 
1625         if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1626                 /*
1627                  * Keep a reference on sk_wmem_alloc, this will be released
1628                  * after sk_write_space() call
1629                  */
1630                 atomic_sub(len - 1, &sk->sk_wmem_alloc);
1631                 sk->sk_write_space(sk);
1632                 len = 1;
1633         }
1634         /*
1635          * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1636          * could not do because of in-flight packets
1637          */
1638         if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1639                 __sk_free(sk);
1640 }
1641 EXPORT_SYMBOL(sock_wfree);
1642 
1643 void skb_orphan_partial(struct sk_buff *skb)
1644 {
1645         /* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1646          * so we do not completely orphan skb, but transfert all
1647          * accounted bytes but one, to avoid unexpected reorders.
1648          */
1649         if (skb->destructor == sock_wfree
1650 #ifdef CONFIG_INET
1651             || skb->destructor == tcp_wfree
1652 #endif
1653                 ) {
1654                 atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1655                 skb->truesize = 1;
1656         } else {
1657                 skb_orphan(skb);
1658         }
1659 }
1660 EXPORT_SYMBOL(skb_orphan_partial);
1661 
1662 /*
1663  * Read buffer destructor automatically called from kfree_skb.
1664  */
1665 void sock_rfree(struct sk_buff *skb)
1666 {
1667         struct sock *sk = skb->sk;
1668         unsigned int len = skb->truesize;
1669 
1670         atomic_sub(len, &sk->sk_rmem_alloc);
1671         sk_mem_uncharge(sk, len);
1672 }
1673 EXPORT_SYMBOL(sock_rfree);
1674 
1675 /*
1676  * Buffer destructor for skbs that are not used directly in read or write
1677  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1678  */
1679 void sock_efree(struct sk_buff *skb)
1680 {
1681         sock_put(skb->sk);
1682 }
1683 EXPORT_SYMBOL(sock_efree);
1684 
1685 kuid_t sock_i_uid(struct sock *sk)
1686 {
1687         kuid_t uid;
1688 
1689         read_lock_bh(&sk->sk_callback_lock);
1690         uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1691         read_unlock_bh(&sk->sk_callback_lock);
1692         return uid;
1693 }
1694 EXPORT_SYMBOL(sock_i_uid);
1695 
1696 unsigned long sock_i_ino(struct sock *sk)
1697 {
1698         unsigned long ino;
1699 
1700         read_lock_bh(&sk->sk_callback_lock);
1701         ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1702         read_unlock_bh(&sk->sk_callback_lock);
1703         return ino;
1704 }
1705 EXPORT_SYMBOL(sock_i_ino);
1706 
1707 /*
1708  * Allocate a skb from the socket's send buffer.
1709  */
1710 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1711                              gfp_t priority)
1712 {
1713         if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1714                 struct sk_buff *skb = alloc_skb(size, priority);
1715                 if (skb) {
1716                         skb_set_owner_w(skb, sk);
1717                         return skb;
1718                 }
1719         }
1720         return NULL;
1721 }
1722 EXPORT_SYMBOL(sock_wmalloc);
1723 
1724 /*
1725  * Allocate a memory block from the socket's option memory buffer.
1726  */
1727 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1728 {
1729         if ((unsigned int)size <= sysctl_optmem_max &&
1730             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1731                 void *mem;
1732                 /* First do the add, to avoid the race if kmalloc
1733                  * might sleep.
1734                  */
1735                 atomic_add(size, &sk->sk_omem_alloc);
1736                 mem = kmalloc(size, priority);
1737                 if (mem)
1738                         return mem;
1739                 atomic_sub(size, &sk->sk_omem_alloc);
1740         }
1741         return NULL;
1742 }
1743 EXPORT_SYMBOL(sock_kmalloc);
1744 
1745 /* Free an option memory block. Note, we actually want the inline
1746  * here as this allows gcc to detect the nullify and fold away the
1747  * condition entirely.
1748  */
1749 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
1750                                   const bool nullify)
1751 {
1752         if (WARN_ON_ONCE(!mem))
1753                 return;
1754         if (nullify)
1755                 kzfree(mem);
1756         else
1757                 kfree(mem);
1758         atomic_sub(size, &sk->sk_omem_alloc);
1759 }
1760 
1761 void sock_kfree_s(struct sock *sk, void *mem, int size)
1762 {
1763         __sock_kfree_s(sk, mem, size, false);
1764 }
1765 EXPORT_SYMBOL(sock_kfree_s);
1766 
1767 void sock_kzfree_s(struct sock *sk, void *mem, int size)
1768 {
1769         __sock_kfree_s(sk, mem, size, true);
1770 }
1771 EXPORT_SYMBOL(sock_kzfree_s);
1772 
1773 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1774    I think, these locks should be removed for datagram sockets.
1775  */
1776 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1777 {
1778         DEFINE_WAIT(wait);
1779 
1780         clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1781         for (;;) {
1782                 if (!timeo)
1783                         break;
1784                 if (signal_pending(current))
1785                         break;
1786                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1787                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1788                 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1789                         break;
1790                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1791                         break;
1792                 if (sk->sk_err)
1793                         break;
1794                 timeo = schedule_timeout(timeo);
1795         }
1796         finish_wait(sk_sleep(sk), &wait);
1797         return timeo;
1798 }
1799 
1800 
1801 /*
1802  *      Generic send/receive buffer handlers
1803  */
1804 
1805 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1806                                      unsigned long data_len, int noblock,
1807                                      int *errcode, int max_page_order)
1808 {
1809         struct sk_buff *skb;
1810         long timeo;
1811         int err;
1812 
1813         timeo = sock_sndtimeo(sk, noblock);
1814         for (;;) {
1815                 err = sock_error(sk);
1816                 if (err != 0)
1817                         goto failure;
1818 
1819                 err = -EPIPE;
1820                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1821                         goto failure;
1822 
1823                 if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
1824                         break;
1825 
1826                 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1827                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1828                 err = -EAGAIN;
1829                 if (!timeo)
1830                         goto failure;
1831                 if (signal_pending(current))
1832                         goto interrupted;
1833                 timeo = sock_wait_for_wmem(sk, timeo);
1834         }
1835         skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
1836                                    errcode, sk->sk_allocation);
1837         if (skb)
1838                 skb_set_owner_w(skb, sk);
1839         return skb;
1840 
1841 interrupted:
1842         err = sock_intr_errno(timeo);
1843 failure:
1844         *errcode = err;
1845         return NULL;
1846 }
1847 EXPORT_SYMBOL(sock_alloc_send_pskb);
1848 
1849 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1850                                     int noblock, int *errcode)
1851 {
1852         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1853 }
1854 EXPORT_SYMBOL(sock_alloc_send_skb);
1855 
1856 /* On 32bit arches, an skb frag is limited to 2^15 */
1857 #define SKB_FRAG_PAGE_ORDER     get_order(32768)
1858 
1859 /**
1860  * skb_page_frag_refill - check that a page_frag contains enough room
1861  * @sz: minimum size of the fragment we want to get
1862  * @pfrag: pointer to page_frag
1863  * @gfp: priority for memory allocation
1864  *
1865  * Note: While this allocator tries to use high order pages, there is
1866  * no guarantee that allocations succeed. Therefore, @sz MUST be
1867  * less or equal than PAGE_SIZE.
1868  */
1869 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
1870 {
1871         if (pfrag->page) {
1872                 if (atomic_read(&pfrag->page->_count) == 1) {
1873                         pfrag->offset = 0;
1874                         return true;
1875                 }
1876                 if (pfrag->offset + sz <= pfrag->size)
1877                         return true;
1878                 put_page(pfrag->page);
1879         }
1880 
1881         pfrag->offset = 0;
1882         if (SKB_FRAG_PAGE_ORDER) {
1883                 pfrag->page = alloc_pages((gfp & ~__GFP_WAIT) | __GFP_COMP |
1884                                           __GFP_NOWARN | __GFP_NORETRY,
1885                                           SKB_FRAG_PAGE_ORDER);
1886                 if (likely(pfrag->page)) {
1887                         pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
1888                         return true;
1889                 }
1890         }
1891         pfrag->page = alloc_page(gfp);
1892         if (likely(pfrag->page)) {
1893                 pfrag->size = PAGE_SIZE;
1894                 return true;
1895         }
1896         return false;
1897 }
1898 EXPORT_SYMBOL(skb_page_frag_refill);
1899 
1900 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1901 {
1902         if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1903                 return true;
1904 
1905         sk_enter_memory_pressure(sk);
1906         sk_stream_moderate_sndbuf(sk);
1907         return false;
1908 }
1909 EXPORT_SYMBOL(sk_page_frag_refill);
1910 
1911 static void __lock_sock(struct sock *sk)
1912         __releases(&sk->sk_lock.slock)
1913         __acquires(&sk->sk_lock.slock)
1914 {
1915         DEFINE_WAIT(wait);
1916 
1917         for (;;) {
1918                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1919                                         TASK_UNINTERRUPTIBLE);
1920                 spin_unlock_bh(&sk->sk_lock.slock);
1921                 schedule();
1922                 spin_lock_bh(&sk->sk_lock.slock);
1923                 if (!sock_owned_by_user(sk))
1924                         break;
1925         }
1926         finish_wait(&sk->sk_lock.wq, &wait);
1927 }
1928 
1929 static void __release_sock(struct sock *sk)
1930         __releases(&sk->sk_lock.slock)
1931         __acquires(&sk->sk_lock.slock)
1932 {
1933         struct sk_buff *skb = sk->sk_backlog.head;
1934 
1935         do {
1936                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1937                 bh_unlock_sock(sk);
1938 
1939                 do {
1940                         struct sk_buff *next = skb->next;
1941 
1942                         prefetch(next);
1943                         WARN_ON_ONCE(skb_dst_is_noref(skb));
1944                         skb->next = NULL;
1945                         sk_backlog_rcv(sk, skb);
1946 
1947                         /*
1948                          * We are in process context here with softirqs
1949                          * disabled, use cond_resched_softirq() to preempt.
1950                          * This is safe to do because we've taken the backlog
1951                          * queue private:
1952                          */
1953                         cond_resched_softirq();
1954 
1955                         skb = next;
1956                 } while (skb != NULL);
1957 
1958                 bh_lock_sock(sk);
1959         } while ((skb = sk->sk_backlog.head) != NULL);
1960 
1961         /*
1962          * Doing the zeroing here guarantee we can not loop forever
1963          * while a wild producer attempts to flood us.
1964          */
1965         sk->sk_backlog.len = 0;
1966 }
1967 
1968 /**
1969  * sk_wait_data - wait for data to arrive at sk_receive_queue
1970  * @sk:    sock to wait on
1971  * @timeo: for how long
1972  *
1973  * Now socket state including sk->sk_err is changed only under lock,
1974  * hence we may omit checks after joining wait queue.
1975  * We check receive queue before schedule() only as optimization;
1976  * it is very likely that release_sock() added new data.
1977  */
1978 int sk_wait_data(struct sock *sk, long *timeo)
1979 {
1980         int rc;
1981         DEFINE_WAIT(wait);
1982 
1983         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1984         set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1985         rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1986         clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1987         finish_wait(sk_sleep(sk), &wait);
1988         return rc;
1989 }
1990 EXPORT_SYMBOL(sk_wait_data);
1991 
1992 /**
1993  *      __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1994  *      @sk: socket
1995  *      @size: memory size to allocate
1996  *      @kind: allocation type
1997  *
1998  *      If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1999  *      rmem allocation. This function assumes that protocols which have
2000  *      memory_pressure use sk_wmem_queued as write buffer accounting.
2001  */
2002 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2003 {
2004         struct proto *prot = sk->sk_prot;
2005         int amt = sk_mem_pages(size);
2006         long allocated;
2007         int parent_status = UNDER_LIMIT;
2008 
2009         sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
2010 
2011         allocated = sk_memory_allocated_add(sk, amt, &parent_status);
2012 
2013         /* Under limit. */
2014         if (parent_status == UNDER_LIMIT &&
2015                         allocated <= sk_prot_mem_limits(sk, 0)) {
2016                 sk_leave_memory_pressure(sk);
2017                 return 1;
2018         }
2019 
2020         /* Under pressure. (we or our parents) */
2021         if ((parent_status > SOFT_LIMIT) ||
2022                         allocated > sk_prot_mem_limits(sk, 1))
2023                 sk_enter_memory_pressure(sk);
2024 
2025         /* Over hard limit (we or our parents) */
2026         if ((parent_status == OVER_LIMIT) ||
2027                         (allocated > sk_prot_mem_limits(sk, 2)))
2028                 goto suppress_allocation;
2029 
2030         /* guarantee minimum buffer size under pressure */
2031         if (kind == SK_MEM_RECV) {
2032                 if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2033                         return 1;
2034 
2035         } else { /* SK_MEM_SEND */
2036                 if (sk->sk_type == SOCK_STREAM) {
2037                         if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2038                                 return 1;
2039                 } else if (atomic_read(&sk->sk_wmem_alloc) <
2040                            prot->sysctl_wmem[0])
2041                                 return 1;
2042         }
2043 
2044         if (sk_has_memory_pressure(sk)) {
2045                 int alloc;
2046 
2047                 if (!sk_under_memory_pressure(sk))
2048                         return 1;
2049                 alloc = sk_sockets_allocated_read_positive(sk);
2050                 if (sk_prot_mem_limits(sk, 2) > alloc *
2051                     sk_mem_pages(sk->sk_wmem_queued +
2052                                  atomic_read(&sk->sk_rmem_alloc) +
2053                                  sk->sk_forward_alloc))
2054                         return 1;
2055         }
2056 
2057 suppress_allocation:
2058 
2059         if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2060                 sk_stream_moderate_sndbuf(sk);
2061 
2062                 /* Fail only if socket is _under_ its sndbuf.
2063                  * In this case we cannot block, so that we have to fail.
2064                  */
2065                 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2066                         return 1;
2067         }
2068 
2069         trace_sock_exceed_buf_limit(sk, prot, allocated);
2070 
2071         /* Alas. Undo changes. */
2072         sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2073 
2074         sk_memory_allocated_sub(sk, amt);
2075 
2076         return 0;
2077 }
2078 EXPORT_SYMBOL(__sk_mem_schedule);
2079 
2080 /**
2081  *      __sk_reclaim - reclaim memory_allocated
2082  *      @sk: socket
2083  */
2084 void __sk_mem_reclaim(struct sock *sk)
2085 {
2086         sk_memory_allocated_sub(sk,
2087                                 sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
2088         sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
2089 
2090         if (sk_under_memory_pressure(sk) &&
2091             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2092                 sk_leave_memory_pressure(sk);
2093 }
2094 EXPORT_SYMBOL(__sk_mem_reclaim);
2095 
2096 
2097 /*
2098  * Set of default routines for initialising struct proto_ops when
2099  * the protocol does not support a particular function. In certain
2100  * cases where it makes no sense for a protocol to have a "do nothing"
2101  * function, some default processing is provided.
2102  */
2103 
2104 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2105 {
2106         return -EOPNOTSUPP;
2107 }
2108 EXPORT_SYMBOL(sock_no_bind);
2109 
2110 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2111                     int len, int flags)
2112 {
2113         return -EOPNOTSUPP;
2114 }
2115 EXPORT_SYMBOL(sock_no_connect);
2116 
2117 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2118 {
2119         return -EOPNOTSUPP;
2120 }
2121 EXPORT_SYMBOL(sock_no_socketpair);
2122 
2123 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2124 {
2125         return -EOPNOTSUPP;
2126 }
2127 EXPORT_SYMBOL(sock_no_accept);
2128 
2129 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2130                     int *len, int peer)
2131 {
2132         return -EOPNOTSUPP;
2133 }
2134 EXPORT_SYMBOL(sock_no_getname);
2135 
2136 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2137 {
2138         return 0;
2139 }
2140 EXPORT_SYMBOL(sock_no_poll);
2141 
2142 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2143 {
2144         return -EOPNOTSUPP;
2145 }
2146 EXPORT_SYMBOL(sock_no_ioctl);
2147 
2148 int sock_no_listen(struct socket *sock, int backlog)
2149 {
2150         return -EOPNOTSUPP;
2151 }
2152 EXPORT_SYMBOL(sock_no_listen);
2153 
2154 int sock_no_shutdown(struct socket *sock, int how)
2155 {
2156         return -EOPNOTSUPP;
2157 }
2158 EXPORT_SYMBOL(sock_no_shutdown);
2159 
2160 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2161                     char __user *optval, unsigned int optlen)
2162 {
2163         return -EOPNOTSUPP;
2164 }
2165 EXPORT_SYMBOL(sock_no_setsockopt);
2166 
2167 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2168                     char __user *optval, int __user *optlen)
2169 {
2170         return -EOPNOTSUPP;
2171 }
2172 EXPORT_SYMBOL(sock_no_getsockopt);
2173 
2174 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2175 {
2176         return -EOPNOTSUPP;
2177 }
2178 EXPORT_SYMBOL(sock_no_sendmsg);
2179 
2180 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2181                     int flags)
2182 {
2183         return -EOPNOTSUPP;
2184 }
2185 EXPORT_SYMBOL(sock_no_recvmsg);
2186 
2187 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2188 {
2189         /* Mirror missing mmap method error code */
2190         return -ENODEV;
2191 }
2192 EXPORT_SYMBOL(sock_no_mmap);
2193 
2194 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2195 {
2196         ssize_t res;
2197         struct msghdr msg = {.msg_flags = flags};
2198         struct kvec iov;
2199         char *kaddr = kmap(page);
2200         iov.iov_base = kaddr + offset;
2201         iov.iov_len = size;
2202         res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2203         kunmap(page);
2204         return res;
2205 }
2206 EXPORT_SYMBOL(sock_no_sendpage);
2207 
2208 /*
2209  *      Default Socket Callbacks
2210  */
2211 
2212 static void sock_def_wakeup(struct sock *sk)
2213 {
2214         struct socket_wq *wq;
2215 
2216         rcu_read_lock();
2217         wq = rcu_dereference(sk->sk_wq);
2218         if (wq_has_sleeper(wq))
2219                 wake_up_interruptible_all(&wq->wait);
2220         rcu_read_unlock();
2221 }
2222 
2223 static void sock_def_error_report(struct sock *sk)
2224 {
2225         struct socket_wq *wq;
2226 
2227         rcu_read_lock();
2228         wq = rcu_dereference(sk->sk_wq);
2229         if (wq_has_sleeper(wq))
2230                 wake_up_interruptible_poll(&wq->wait, POLLERR);
2231         sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2232         rcu_read_unlock();
2233 }
2234 
2235 static void sock_def_readable(struct sock *sk)
2236 {
2237         struct socket_wq *wq;
2238 
2239         rcu_read_lock();
2240         wq = rcu_dereference(sk->sk_wq);
2241         if (wq_has_sleeper(wq))
2242                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2243                                                 POLLRDNORM | POLLRDBAND);
2244         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2245         rcu_read_unlock();
2246 }
2247 
2248 static void sock_def_write_space(struct sock *sk)
2249 {
2250         struct socket_wq *wq;
2251 
2252         rcu_read_lock();
2253 
2254         /* Do not wake up a writer until he can make "significant"
2255          * progress.  --DaveM
2256          */
2257         if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2258                 wq = rcu_dereference(sk->sk_wq);
2259                 if (wq_has_sleeper(wq))
2260                         wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2261                                                 POLLWRNORM | POLLWRBAND);
2262 
2263                 /* Should agree with poll, otherwise some programs break */
2264                 if (sock_writeable(sk))
2265                         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2266         }
2267 
2268         rcu_read_unlock();
2269 }
2270 
2271 static void sock_def_destruct(struct sock *sk)
2272 {
2273         kfree(sk->sk_protinfo);
2274 }
2275 
2276 void sk_send_sigurg(struct sock *sk)
2277 {
2278         if (sk->sk_socket && sk->sk_socket->file)
2279                 if (send_sigurg(&sk->sk_socket->file->f_owner))
2280                         sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2281 }
2282 EXPORT_SYMBOL(sk_send_sigurg);
2283 
2284 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2285                     unsigned long expires)
2286 {
2287         if (!mod_timer(timer, expires))
2288                 sock_hold(sk);
2289 }
2290 EXPORT_SYMBOL(sk_reset_timer);
2291 
2292 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2293 {
2294         if (del_timer(timer))
2295                 __sock_put(sk);
2296 }
2297 EXPORT_SYMBOL(sk_stop_timer);
2298 
2299 void sock_init_data(struct socket *sock, struct sock *sk)
2300 {
2301         skb_queue_head_init(&sk->sk_receive_queue);
2302         skb_queue_head_init(&sk->sk_write_queue);
2303         skb_queue_head_init(&sk->sk_error_queue);
2304 
2305         sk->sk_send_head        =       NULL;
2306 
2307         init_timer(&sk->sk_timer);
2308 
2309         sk->sk_allocation       =       GFP_KERNEL;
2310         sk->sk_rcvbuf           =       sysctl_rmem_default;
2311         sk->sk_sndbuf           =       sysctl_wmem_default;
2312         sk->sk_state            =       TCP_CLOSE;
2313         sk_set_socket(sk, sock);
2314 
2315         sock_set_flag(sk, SOCK_ZAPPED);
2316 
2317         if (sock) {
2318                 sk->sk_type     =       sock->type;
2319                 sk->sk_wq       =       sock->wq;
2320                 sock->sk        =       sk;
2321         } else
2322                 sk->sk_wq       =       NULL;
2323 
2324         spin_lock_init(&sk->sk_dst_lock);
2325         rwlock_init(&sk->sk_callback_lock);
2326         lockdep_set_class_and_name(&sk->sk_callback_lock,
2327                         af_callback_keys + sk->sk_family,
2328                         af_family_clock_key_strings[sk->sk_family]);
2329 
2330         sk->sk_state_change     =       sock_def_wakeup;
2331         sk->sk_data_ready       =       sock_def_readable;
2332         sk->sk_write_space      =       sock_def_write_space;
2333         sk->sk_error_report     =       sock_def_error_report;
2334         sk->sk_destruct         =       sock_def_destruct;
2335 
2336         sk->sk_frag.page        =       NULL;
2337         sk->sk_frag.offset      =       0;
2338         sk->sk_peek_off         =       -1;
2339 
2340         sk->sk_peer_pid         =       NULL;
2341         sk->sk_peer_cred        =       NULL;
2342         sk->sk_write_pending    =       0;
2343         sk->sk_rcvlowat         =       1;
2344         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
2345         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
2346 
2347         sk->sk_stamp = ktime_set(-1L, 0);
2348 
2349 #ifdef CONFIG_NET_RX_BUSY_POLL
2350         sk->sk_napi_id          =       0;
2351         sk->sk_ll_usec          =       sysctl_net_busy_read;
2352 #endif
2353 
2354         sk->sk_max_pacing_rate = ~0U;
2355         sk->sk_pacing_rate = ~0U;
2356         /*
2357          * Before updating sk_refcnt, we must commit prior changes to memory
2358          * (Documentation/RCU/rculist_nulls.txt for details)
2359          */
2360         smp_wmb();
2361         atomic_set(&sk->sk_refcnt, 1);
2362         atomic_set(&sk->sk_drops, 0);
2363 }
2364 EXPORT_SYMBOL(sock_init_data);
2365 
2366 void lock_sock_nested(struct sock *sk, int subclass)
2367 {
2368         might_sleep();
2369         spin_lock_bh(&sk->sk_lock.slock);
2370         if (sk->sk_lock.owned)
2371                 __lock_sock(sk);
2372         sk->sk_lock.owned = 1;
2373         spin_unlock(&sk->sk_lock.slock);
2374         /*
2375          * The sk_lock has mutex_lock() semantics here:
2376          */
2377         mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2378         local_bh_enable();
2379 }
2380 EXPORT_SYMBOL(lock_sock_nested);
2381 
2382 void release_sock(struct sock *sk)
2383 {
2384         /*
2385          * The sk_lock has mutex_unlock() semantics:
2386          */
2387         mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2388 
2389         spin_lock_bh(&sk->sk_lock.slock);
2390         if (sk->sk_backlog.tail)
2391                 __release_sock(sk);
2392 
2393         /* Warning : release_cb() might need to release sk ownership,
2394          * ie call sock_release_ownership(sk) before us.
2395          */
2396         if (sk->sk_prot->release_cb)
2397                 sk->sk_prot->release_cb(sk);
2398 
2399         sock_release_ownership(sk);
2400         if (waitqueue_active(&sk->sk_lock.wq))
2401                 wake_up(&sk->sk_lock.wq);
2402         spin_unlock_bh(&sk->sk_lock.slock);
2403 }
2404 EXPORT_SYMBOL(release_sock);
2405 
2406 /**
2407  * lock_sock_fast - fast version of lock_sock
2408  * @sk: socket
2409  *
2410  * This version should be used for very small section, where process wont block
2411  * return false if fast path is taken
2412  *   sk_lock.slock locked, owned = 0, BH disabled
2413  * return true if slow path is taken
2414  *   sk_lock.slock unlocked, owned = 1, BH enabled
2415  */
2416 bool lock_sock_fast(struct sock *sk)
2417 {
2418         might_sleep();
2419         spin_lock_bh(&sk->sk_lock.slock);
2420 
2421         if (!sk->sk_lock.owned)
2422                 /*
2423                  * Note : We must disable BH
2424                  */
2425                 return false;
2426 
2427         __lock_sock(sk);
2428         sk->sk_lock.owned = 1;
2429         spin_unlock(&sk->sk_lock.slock);
2430         /*
2431          * The sk_lock has mutex_lock() semantics here:
2432          */
2433         mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2434         local_bh_enable();
2435         return true;
2436 }
2437 EXPORT_SYMBOL(lock_sock_fast);
2438 
2439 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2440 {
2441         struct timeval tv;
2442         if (!sock_flag(sk, SOCK_TIMESTAMP))
2443                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2444         tv = ktime_to_timeval(sk->sk_stamp);
2445         if (tv.tv_sec == -1)
2446                 return -ENOENT;
2447         if (tv.tv_sec == 0) {
2448                 sk->sk_stamp = ktime_get_real();
2449                 tv = ktime_to_timeval(sk->sk_stamp);
2450         }
2451         return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2452 }
2453 EXPORT_SYMBOL(sock_get_timestamp);
2454 
2455 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2456 {
2457         struct timespec ts;
2458         if (!sock_flag(sk, SOCK_TIMESTAMP))
2459                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2460         ts = ktime_to_timespec(sk->sk_stamp);
2461         if (ts.tv_sec == -1)
2462                 return -ENOENT;
2463         if (ts.tv_sec == 0) {
2464                 sk->sk_stamp = ktime_get_real();
2465                 ts = ktime_to_timespec(sk->sk_stamp);
2466         }
2467         return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2468 }
2469 EXPORT_SYMBOL(sock_get_timestampns);
2470 
2471 void sock_enable_timestamp(struct sock *sk, int flag)
2472 {
2473         if (!sock_flag(sk, flag)) {
2474                 unsigned long previous_flags = sk->sk_flags;
2475 
2476                 sock_set_flag(sk, flag);
2477                 /*
2478                  * we just set one of the two flags which require net
2479                  * time stamping, but time stamping might have been on
2480                  * already because of the other one
2481                  */
2482                 if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2483                         net_enable_timestamp();
2484         }
2485 }
2486 
2487 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2488                        int level, int type)
2489 {
2490         struct sock_exterr_skb *serr;
2491         struct sk_buff *skb;
2492         int copied, err;
2493 
2494         err = -EAGAIN;
2495         skb = sock_dequeue_err_skb(sk);
2496         if (skb == NULL)
2497                 goto out;
2498 
2499         copied = skb->len;
2500         if (copied > len) {
2501                 msg->msg_flags |= MSG_TRUNC;
2502                 copied = len;
2503         }
2504         err = skb_copy_datagram_msg(skb, 0, msg, copied);
2505         if (err)
2506                 goto out_free_skb;
2507 
2508         sock_recv_timestamp(msg, sk, skb);
2509 
2510         serr = SKB_EXT_ERR(skb);
2511         put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2512 
2513         msg->msg_flags |= MSG_ERRQUEUE;
2514         err = copied;
2515 
2516 out_free_skb:
2517         kfree_skb(skb);
2518 out:
2519         return err;
2520 }
2521 EXPORT_SYMBOL(sock_recv_errqueue);
2522 
2523 /*
2524  *      Get a socket option on an socket.
2525  *
2526  *      FIX: POSIX 1003.1g is very ambiguous here. It states that
2527  *      asynchronous errors should be reported by getsockopt. We assume
2528  *      this means if you specify SO_ERROR (otherwise whats the point of it).
2529  */
2530 int 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         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2536 }
2537 EXPORT_SYMBOL(sock_common_getsockopt);
2538 
2539 #ifdef CONFIG_COMPAT
2540 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2541                                   char __user *optval, int __user *optlen)
2542 {
2543         struct sock *sk = sock->sk;
2544 
2545         if (sk->sk_prot->compat_getsockopt != NULL)
2546                 return sk->sk_prot->compat_getsockopt(sk, level, optname,
2547                                                       optval, optlen);
2548         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2549 }
2550 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2551 #endif
2552 
2553 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
2554                         int flags)
2555 {
2556         struct sock *sk = sock->sk;
2557         int addr_len = 0;
2558         int err;
2559 
2560         err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
2561                                    flags & ~MSG_DONTWAIT, &addr_len);
2562         if (err >= 0)
2563                 msg->msg_namelen = addr_len;
2564         return err;
2565 }
2566 EXPORT_SYMBOL(sock_common_recvmsg);
2567 
2568 /*
2569  *      Set socket options on an inet socket.
2570  */
2571 int 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         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2577 }
2578 EXPORT_SYMBOL(sock_common_setsockopt);
2579 
2580 #ifdef CONFIG_COMPAT
2581 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2582                                   char __user *optval, unsigned int optlen)
2583 {
2584         struct sock *sk = sock->sk;
2585 
2586         if (sk->sk_prot->compat_setsockopt != NULL)
2587                 return sk->sk_prot->compat_setsockopt(sk, level, optname,
2588                                                       optval, optlen);
2589         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2590 }
2591 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2592 #endif
2593 
2594 void sk_common_release(struct sock *sk)
2595 {
2596         if (sk->sk_prot->destroy)
2597                 sk->sk_prot->destroy(sk);
2598 
2599         /*
2600          * Observation: when sock_common_release is called, processes have
2601          * no access to socket. But net still has.
2602          * Step one, detach it from networking:
2603          *
2604          * A. Remove from hash tables.
2605          */
2606 
2607         sk->sk_prot->unhash(sk);
2608 
2609         /*
2610          * In this point socket cannot receive new packets, but it is possible
2611          * that some packets are in flight because some CPU runs receiver and
2612          * did hash table lookup before we unhashed socket. They will achieve
2613          * receive queue and will be purged by socket destructor.
2614          *
2615          * Also we still have packets pending on receive queue and probably,
2616          * our own packets waiting in device queues. sock_destroy will drain
2617          * receive queue, but transmitted packets will delay socket destruction
2618          * until the last reference will be released.
2619          */
2620 
2621         sock_orphan(sk);
2622 
2623         xfrm_sk_free_policy(sk);
2624 
2625         sk_refcnt_debug_release(sk);
2626 
2627         if (sk->sk_frag.page) {
2628                 put_page(sk->sk_frag.page);
2629                 sk->sk_frag.page = NULL;
2630         }
2631 
2632         sock_put(sk);
2633 }
2634 EXPORT_SYMBOL(sk_common_release);
2635 
2636 #ifdef CONFIG_PROC_FS
2637 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
2638 struct prot_inuse {
2639         int val[PROTO_INUSE_NR];
2640 };
2641 
2642 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2643 
2644 #ifdef CONFIG_NET_NS
2645 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2646 {
2647         __this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2648 }
2649 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2650 
2651 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2652 {
2653         int cpu, idx = prot->inuse_idx;
2654         int res = 0;
2655 
2656         for_each_possible_cpu(cpu)
2657                 res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2658 
2659         return res >= 0 ? res : 0;
2660 }
2661 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2662 
2663 static int __net_init sock_inuse_init_net(struct net *net)
2664 {
2665         net->core.inuse = alloc_percpu(struct prot_inuse);
2666         return net->core.inuse ? 0 : -ENOMEM;
2667 }
2668 
2669 static void __net_exit sock_inuse_exit_net(struct net *net)
2670 {
2671         free_percpu(net->core.inuse);
2672 }
2673 
2674 static struct pernet_operations net_inuse_ops = {
2675         .init = sock_inuse_init_net,
2676         .exit = sock_inuse_exit_net,
2677 };
2678 
2679 static __init int net_inuse_init(void)
2680 {
2681         if (register_pernet_subsys(&net_inuse_ops))
2682                 panic("Cannot initialize net inuse counters");
2683 
2684         return 0;
2685 }
2686 
2687 core_initcall(net_inuse_init);
2688 #else
2689 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2690 
2691 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2692 {
2693         __this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2694 }
2695 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2696 
2697 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2698 {
2699         int cpu, idx = prot->inuse_idx;
2700         int res = 0;
2701 
2702         for_each_possible_cpu(cpu)
2703                 res += per_cpu(prot_inuse, cpu).val[idx];
2704 
2705         return res >= 0 ? res : 0;
2706 }
2707 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2708 #endif
2709 
2710 static void assign_proto_idx(struct proto *prot)
2711 {
2712         prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2713 
2714         if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2715                 pr_err("PROTO_INUSE_NR exhausted\n");
2716                 return;
2717         }
2718 
2719         set_bit(prot->inuse_idx, proto_inuse_idx);
2720 }
2721 
2722 static void release_proto_idx(struct proto *prot)
2723 {
2724         if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2725                 clear_bit(prot->inuse_idx, proto_inuse_idx);
2726 }
2727 #else
2728 static inline void assign_proto_idx(struct proto *prot)
2729 {
2730 }
2731 
2732 static inline void release_proto_idx(struct proto *prot)
2733 {
2734 }
2735 #endif
2736 
2737 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
2738 {
2739         if (!rsk_prot)
2740                 return;
2741         kfree(rsk_prot->slab_name);
2742         rsk_prot->slab_name = NULL;
2743         if (rsk_prot->slab) {
2744                 kmem_cache_destroy(rsk_prot->slab);
2745                 rsk_prot->slab = NULL;
2746         }
2747 }
2748 
2749 static int req_prot_init(const struct proto *prot)
2750 {
2751         struct request_sock_ops *rsk_prot = prot->rsk_prot;
2752 
2753         if (!rsk_prot)
2754                 return 0;
2755 
2756         rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
2757                                         prot->name);
2758         if (!rsk_prot->slab_name)
2759                 return -ENOMEM;
2760 
2761         rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
2762                                            rsk_prot->obj_size, 0,
2763                                            0, NULL);
2764 
2765         if (!rsk_prot->slab) {
2766                 pr_crit("%s: Can't create request sock SLAB cache!\n",
2767                         prot->name);
2768                 return -ENOMEM;
2769         }
2770         return 0;
2771 }
2772 
2773 int proto_register(struct proto *prot, int alloc_slab)
2774 {
2775         if (alloc_slab) {
2776                 prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2777                                         SLAB_HWCACHE_ALIGN | prot->slab_flags,
2778                                         NULL);
2779 
2780                 if (prot->slab == NULL) {
2781                         pr_crit("%s: Can't create sock SLAB cache!\n",
2782                                 prot->name);
2783                         goto out;
2784                 }
2785 
2786                 if (req_prot_init(prot))
2787                         goto out_free_request_sock_slab;
2788 
2789                 if (prot->twsk_prot != NULL) {
2790                         prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2791 
2792                         if (prot->twsk_prot->twsk_slab_name == NULL)
2793                                 goto out_free_request_sock_slab;
2794 
2795                         prot->twsk_prot->twsk_slab =
2796                                 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2797                                                   prot->twsk_prot->twsk_obj_size,
2798                                                   0,
2799                                                   prot->slab_flags,
2800                                                   NULL);
2801                         if (prot->twsk_prot->twsk_slab == NULL)
2802                                 goto out_free_timewait_sock_slab_name;
2803                 }
2804         }
2805 
2806         mutex_lock(&proto_list_mutex);
2807         list_add(&prot->node, &proto_list);
2808         assign_proto_idx(prot);
2809         mutex_unlock(&proto_list_mutex);
2810         return 0;
2811 
2812 out_free_timewait_sock_slab_name:
2813         kfree(prot->twsk_prot->twsk_slab_name);
2814 out_free_request_sock_slab:
2815         req_prot_cleanup(prot->rsk_prot);
2816 
2817         kmem_cache_destroy(prot->slab);
2818         prot->slab = NULL;
2819 out:
2820         return -ENOBUFS;
2821 }
2822 EXPORT_SYMBOL(proto_register);
2823 
2824 void proto_unregister(struct proto *prot)
2825 {
2826         mutex_lock(&proto_list_mutex);
2827         release_proto_idx(prot);
2828         list_del(&prot->node);
2829         mutex_unlock(&proto_list_mutex);
2830 
2831         if (prot->slab != NULL) {
2832                 kmem_cache_destroy(prot->slab);
2833                 prot->slab = NULL;
2834         }
2835 
2836         req_prot_cleanup(prot->rsk_prot);
2837 
2838         if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2839                 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2840                 kfree(prot->twsk_prot->twsk_slab_name);
2841                 prot->twsk_prot->twsk_slab = NULL;
2842         }
2843 }
2844 EXPORT_SYMBOL(proto_unregister);
2845 
2846 #ifdef CONFIG_PROC_FS
2847 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2848         __acquires(proto_list_mutex)
2849 {
2850         mutex_lock(&proto_list_mutex);
2851         return seq_list_start_head(&proto_list, *pos);
2852 }
2853 
2854 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2855 {
2856         return seq_list_next(v, &proto_list, pos);
2857 }
2858 
2859 static void proto_seq_stop(struct seq_file *seq, void *v)
2860         __releases(proto_list_mutex)
2861 {
2862         mutex_unlock(&proto_list_mutex);
2863 }
2864 
2865 static char proto_method_implemented(const void *method)
2866 {
2867         return method == NULL ? 'n' : 'y';
2868 }
2869 static long sock_prot_memory_allocated(struct proto *proto)
2870 {
2871         return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2872 }
2873 
2874 static char *sock_prot_memory_pressure(struct proto *proto)
2875 {
2876         return proto->memory_pressure != NULL ?
2877         proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2878 }
2879 
2880 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2881 {
2882 
2883         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2884                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2885                    proto->name,
2886                    proto->obj_size,
2887                    sock_prot_inuse_get(seq_file_net(seq), proto),
2888                    sock_prot_memory_allocated(proto),
2889                    sock_prot_memory_pressure(proto),
2890                    proto->max_header,
2891                    proto->slab == NULL ? "no" : "yes",
2892                    module_name(proto->owner),
2893                    proto_method_implemented(proto->close),
2894                    proto_method_implemented(proto->connect),
2895                    proto_method_implemented(proto->disconnect),
2896                    proto_method_implemented(proto->accept),
2897                    proto_method_implemented(proto->ioctl),
2898                    proto_method_implemented(proto->init),
2899                    proto_method_implemented(proto->destroy),
2900                    proto_method_implemented(proto->shutdown),
2901                    proto_method_implemented(proto->setsockopt),
2902                    proto_method_implemented(proto->getsockopt),
2903                    proto_method_implemented(proto->sendmsg),
2904                    proto_method_implemented(proto->recvmsg),
2905                    proto_method_implemented(proto->sendpage),
2906                    proto_method_implemented(proto->bind),
2907                    proto_method_implemented(proto->backlog_rcv),
2908                    proto_method_implemented(proto->hash),
2909                    proto_method_implemented(proto->unhash),
2910                    proto_method_implemented(proto->get_port),
2911                    proto_method_implemented(proto->enter_memory_pressure));
2912 }
2913 
2914 static int proto_seq_show(struct seq_file *seq, void *v)
2915 {
2916         if (v == &proto_list)
2917                 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2918                            "protocol",
2919                            "size",
2920                            "sockets",
2921                            "memory",
2922                            "press",
2923                            "maxhdr",
2924                            "slab",
2925                            "module",
2926                            "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2927         else
2928                 proto_seq_printf(seq, list_entry(v, struct proto, node));
2929         return 0;
2930 }
2931 
2932 static const struct seq_operations proto_seq_ops = {
2933         .start  = proto_seq_start,
2934         .next   = proto_seq_next,
2935         .stop   = proto_seq_stop,
2936         .show   = proto_seq_show,
2937 };
2938 
2939 static int proto_seq_open(struct inode *inode, struct file *file)
2940 {
2941         return seq_open_net(inode, file, &proto_seq_ops,
2942                             sizeof(struct seq_net_private));
2943 }
2944 
2945 static const struct file_operations proto_seq_fops = {
2946         .owner          = THIS_MODULE,
2947         .open           = proto_seq_open,
2948         .read           = seq_read,
2949         .llseek         = seq_lseek,
2950         .release        = seq_release_net,
2951 };
2952 
2953 static __net_init int proto_init_net(struct net *net)
2954 {
2955         if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
2956                 return -ENOMEM;
2957 
2958         return 0;
2959 }
2960 
2961 static __net_exit void proto_exit_net(struct net *net)
2962 {
2963         remove_proc_entry("protocols", net->proc_net);
2964 }
2965 
2966 
2967 static __net_initdata struct pernet_operations proto_net_ops = {
2968         .init = proto_init_net,
2969         .exit = proto_exit_net,
2970 };
2971 
2972 static int __init proto_init(void)
2973 {
2974         return register_pernet_subsys(&proto_net_ops);
2975 }
2976 
2977 subsys_initcall(proto_init);
2978 
2979 #endif /* PROC_FS */
2980 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us