Version:  2.0.40 2.2.26 2.4.37 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0

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. However, if SOCK_MEMALLOC is cleared while
358          * it has rmem allocations there is a risk that the user of the
359          * socket cannot make forward progress due to exceeding the rmem
360          * limits. By rights, sk_clear_memalloc() should only be called
361          * on sockets being torn down but warn and reset the accounting if
362          * that assumption breaks.
363          */
364         if (WARN_ON(sk->sk_forward_alloc))
365                 sk_mem_reclaim(sk);
366 }
367 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
368 
369 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
370 {
371         int ret;
372         unsigned long pflags = current->flags;
373 
374         /* these should have been dropped before queueing */
375         BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
376 
377         current->flags |= PF_MEMALLOC;
378         ret = sk->sk_backlog_rcv(sk, skb);
379         tsk_restore_flags(current, pflags, PF_MEMALLOC);
380 
381         return ret;
382 }
383 EXPORT_SYMBOL(__sk_backlog_rcv);
384 
385 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
386 {
387         struct timeval tv;
388 
389         if (optlen < sizeof(tv))
390                 return -EINVAL;
391         if (copy_from_user(&tv, optval, sizeof(tv)))
392                 return -EFAULT;
393         if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
394                 return -EDOM;
395 
396         if (tv.tv_sec < 0) {
397                 static int warned __read_mostly;
398 
399                 *timeo_p = 0;
400                 if (warned < 10 && net_ratelimit()) {
401                         warned++;
402                         pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
403                                 __func__, current->comm, task_pid_nr(current));
404                 }
405                 return 0;
406         }
407         *timeo_p = MAX_SCHEDULE_TIMEOUT;
408         if (tv.tv_sec == 0 && tv.tv_usec == 0)
409                 return 0;
410         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
411                 *timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
412         return 0;
413 }
414 
415 static void sock_warn_obsolete_bsdism(const char *name)
416 {
417         static int warned;
418         static char warncomm[TASK_COMM_LEN];
419         if (strcmp(warncomm, current->comm) && warned < 5) {
420                 strcpy(warncomm,  current->comm);
421                 pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
422                         warncomm, name);
423                 warned++;
424         }
425 }
426 
427 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
428 
429 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
430 {
431         if (sk->sk_flags & flags) {
432                 sk->sk_flags &= ~flags;
433                 if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
434                         net_disable_timestamp();
435         }
436 }
437 
438 
439 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
440 {
441         int err;
442         unsigned long flags;
443         struct sk_buff_head *list = &sk->sk_receive_queue;
444 
445         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
446                 atomic_inc(&sk->sk_drops);
447                 trace_sock_rcvqueue_full(sk, skb);
448                 return -ENOMEM;
449         }
450 
451         err = sk_filter(sk, skb);
452         if (err)
453                 return err;
454 
455         if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
456                 atomic_inc(&sk->sk_drops);
457                 return -ENOBUFS;
458         }
459 
460         skb->dev = NULL;
461         skb_set_owner_r(skb, sk);
462 
463         /* we escape from rcu protected region, make sure we dont leak
464          * a norefcounted dst
465          */
466         skb_dst_force(skb);
467 
468         spin_lock_irqsave(&list->lock, flags);
469         skb->dropcount = atomic_read(&sk->sk_drops);
470         __skb_queue_tail(list, skb);
471         spin_unlock_irqrestore(&list->lock, flags);
472 
473         if (!sock_flag(sk, SOCK_DEAD))
474                 sk->sk_data_ready(sk);
475         return 0;
476 }
477 EXPORT_SYMBOL(sock_queue_rcv_skb);
478 
479 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
480 {
481         int rc = NET_RX_SUCCESS;
482 
483         if (sk_filter(sk, skb))
484                 goto discard_and_relse;
485 
486         skb->dev = NULL;
487 
488         if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
489                 atomic_inc(&sk->sk_drops);
490                 goto discard_and_relse;
491         }
492         if (nested)
493                 bh_lock_sock_nested(sk);
494         else
495                 bh_lock_sock(sk);
496         if (!sock_owned_by_user(sk)) {
497                 /*
498                  * trylock + unlock semantics:
499                  */
500                 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
501 
502                 rc = sk_backlog_rcv(sk, skb);
503 
504                 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
505         } else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
506                 bh_unlock_sock(sk);
507                 atomic_inc(&sk->sk_drops);
508                 goto discard_and_relse;
509         }
510 
511         bh_unlock_sock(sk);
512 out:
513         sock_put(sk);
514         return rc;
515 discard_and_relse:
516         kfree_skb(skb);
517         goto out;
518 }
519 EXPORT_SYMBOL(sk_receive_skb);
520 
521 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
522 {
523         struct dst_entry *dst = __sk_dst_get(sk);
524 
525         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
526                 sk_tx_queue_clear(sk);
527                 RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
528                 dst_release(dst);
529                 return NULL;
530         }
531 
532         return dst;
533 }
534 EXPORT_SYMBOL(__sk_dst_check);
535 
536 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
537 {
538         struct dst_entry *dst = sk_dst_get(sk);
539 
540         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
541                 sk_dst_reset(sk);
542                 dst_release(dst);
543                 return NULL;
544         }
545 
546         return dst;
547 }
548 EXPORT_SYMBOL(sk_dst_check);
549 
550 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
551                                 int optlen)
552 {
553         int ret = -ENOPROTOOPT;
554 #ifdef CONFIG_NETDEVICES
555         struct net *net = sock_net(sk);
556         char devname[IFNAMSIZ];
557         int index;
558 
559         /* Sorry... */
560         ret = -EPERM;
561         if (!ns_capable(net->user_ns, CAP_NET_RAW))
562                 goto out;
563 
564         ret = -EINVAL;
565         if (optlen < 0)
566                 goto out;
567 
568         /* Bind this socket to a particular device like "eth0",
569          * as specified in the passed interface name. If the
570          * name is "" or the option length is zero the socket
571          * is not bound.
572          */
573         if (optlen > IFNAMSIZ - 1)
574                 optlen = IFNAMSIZ - 1;
575         memset(devname, 0, sizeof(devname));
576 
577         ret = -EFAULT;
578         if (copy_from_user(devname, optval, optlen))
579                 goto out;
580 
581         index = 0;
582         if (devname[0] != '\0') {
583                 struct net_device *dev;
584 
585                 rcu_read_lock();
586                 dev = dev_get_by_name_rcu(net, devname);
587                 if (dev)
588                         index = dev->ifindex;
589                 rcu_read_unlock();
590                 ret = -ENODEV;
591                 if (!dev)
592                         goto out;
593         }
594 
595         lock_sock(sk);
596         sk->sk_bound_dev_if = index;
597         sk_dst_reset(sk);
598         release_sock(sk);
599 
600         ret = 0;
601 
602 out:
603 #endif
604 
605         return ret;
606 }
607 
608 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
609                                 int __user *optlen, int len)
610 {
611         int ret = -ENOPROTOOPT;
612 #ifdef CONFIG_NETDEVICES
613         struct net *net = sock_net(sk);
614         char devname[IFNAMSIZ];
615 
616         if (sk->sk_bound_dev_if == 0) {
617                 len = 0;
618                 goto zero;
619         }
620 
621         ret = -EINVAL;
622         if (len < IFNAMSIZ)
623                 goto out;
624 
625         ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
626         if (ret)
627                 goto out;
628 
629         len = strlen(devname) + 1;
630 
631         ret = -EFAULT;
632         if (copy_to_user(optval, devname, len))
633                 goto out;
634 
635 zero:
636         ret = -EFAULT;
637         if (put_user(len, optlen))
638                 goto out;
639 
640         ret = 0;
641 
642 out:
643 #endif
644 
645         return ret;
646 }
647 
648 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
649 {
650         if (valbool)
651                 sock_set_flag(sk, bit);
652         else
653                 sock_reset_flag(sk, bit);
654 }
655 
656 bool sk_mc_loop(struct sock *sk)
657 {
658         if (dev_recursion_level())
659                 return false;
660         if (!sk)
661                 return true;
662         switch (sk->sk_family) {
663         case AF_INET:
664                 return inet_sk(sk)->mc_loop;
665 #if IS_ENABLED(CONFIG_IPV6)
666         case AF_INET6:
667                 return inet6_sk(sk)->mc_loop;
668 #endif
669         }
670         WARN_ON(1);
671         return true;
672 }
673 EXPORT_SYMBOL(sk_mc_loop);
674 
675 /*
676  *      This is meant for all protocols to use and covers goings on
677  *      at the socket level. Everything here is generic.
678  */
679 
680 int sock_setsockopt(struct socket *sock, int level, int optname,
681                     char __user *optval, unsigned int optlen)
682 {
683         struct sock *sk = sock->sk;
684         int val;
685         int valbool;
686         struct linger ling;
687         int ret = 0;
688 
689         /*
690          *      Options without arguments
691          */
692 
693         if (optname == SO_BINDTODEVICE)
694                 return sock_setbindtodevice(sk, optval, optlen);
695 
696         if (optlen < sizeof(int))
697                 return -EINVAL;
698 
699         if (get_user(val, (int __user *)optval))
700                 return -EFAULT;
701 
702         valbool = val ? 1 : 0;
703 
704         lock_sock(sk);
705 
706         switch (optname) {
707         case SO_DEBUG:
708                 if (val && !capable(CAP_NET_ADMIN))
709                         ret = -EACCES;
710                 else
711                         sock_valbool_flag(sk, SOCK_DBG, valbool);
712                 break;
713         case SO_REUSEADDR:
714                 sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
715                 break;
716         case SO_REUSEPORT:
717                 sk->sk_reuseport = valbool;
718                 break;
719         case SO_TYPE:
720         case SO_PROTOCOL:
721         case SO_DOMAIN:
722         case SO_ERROR:
723                 ret = -ENOPROTOOPT;
724                 break;
725         case SO_DONTROUTE:
726                 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
727                 break;
728         case SO_BROADCAST:
729                 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
730                 break;
731         case SO_SNDBUF:
732                 /* Don't error on this BSD doesn't and if you think
733                  * about it this is right. Otherwise apps have to
734                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
735                  * are treated in BSD as hints
736                  */
737                 val = min_t(u32, val, sysctl_wmem_max);
738 set_sndbuf:
739                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
740                 sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
741                 /* Wake up sending tasks if we upped the value. */
742                 sk->sk_write_space(sk);
743                 break;
744 
745         case SO_SNDBUFFORCE:
746                 if (!capable(CAP_NET_ADMIN)) {
747                         ret = -EPERM;
748                         break;
749                 }
750                 goto set_sndbuf;
751 
752         case SO_RCVBUF:
753                 /* Don't error on this BSD doesn't and if you think
754                  * about it this is right. Otherwise apps have to
755                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
756                  * are treated in BSD as hints
757                  */
758                 val = min_t(u32, val, sysctl_rmem_max);
759 set_rcvbuf:
760                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
761                 /*
762                  * We double it on the way in to account for
763                  * "struct sk_buff" etc. overhead.   Applications
764                  * assume that the SO_RCVBUF setting they make will
765                  * allow that much actual data to be received on that
766                  * socket.
767                  *
768                  * Applications are unaware that "struct sk_buff" and
769                  * other overheads allocate from the receive buffer
770                  * during socket buffer allocation.
771                  *
772                  * And after considering the possible alternatives,
773                  * returning the value we actually used in getsockopt
774                  * is the most desirable behavior.
775                  */
776                 sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
777                 break;
778 
779         case SO_RCVBUFFORCE:
780                 if (!capable(CAP_NET_ADMIN)) {
781                         ret = -EPERM;
782                         break;
783                 }
784                 goto set_rcvbuf;
785 
786         case SO_KEEPALIVE:
787 #ifdef CONFIG_INET
788                 if (sk->sk_protocol == IPPROTO_TCP &&
789                     sk->sk_type == SOCK_STREAM)
790                         tcp_set_keepalive(sk, valbool);
791 #endif
792                 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
793                 break;
794 
795         case SO_OOBINLINE:
796                 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
797                 break;
798 
799         case SO_NO_CHECK:
800                 sk->sk_no_check_tx = valbool;
801                 break;
802 
803         case SO_PRIORITY:
804                 if ((val >= 0 && val <= 6) ||
805                     ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
806                         sk->sk_priority = val;
807                 else
808                         ret = -EPERM;
809                 break;
810 
811         case SO_LINGER:
812                 if (optlen < sizeof(ling)) {
813                         ret = -EINVAL;  /* 1003.1g */
814                         break;
815                 }
816                 if (copy_from_user(&ling, optval, sizeof(ling))) {
817                         ret = -EFAULT;
818                         break;
819                 }
820                 if (!ling.l_onoff)
821                         sock_reset_flag(sk, SOCK_LINGER);
822                 else {
823 #if (BITS_PER_LONG == 32)
824                         if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
825                                 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
826                         else
827 #endif
828                                 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
829                         sock_set_flag(sk, SOCK_LINGER);
830                 }
831                 break;
832 
833         case SO_BSDCOMPAT:
834                 sock_warn_obsolete_bsdism("setsockopt");
835                 break;
836 
837         case SO_PASSCRED:
838                 if (valbool)
839                         set_bit(SOCK_PASSCRED, &sock->flags);
840                 else
841                         clear_bit(SOCK_PASSCRED, &sock->flags);
842                 break;
843 
844         case SO_TIMESTAMP:
845         case SO_TIMESTAMPNS:
846                 if (valbool)  {
847                         if (optname == SO_TIMESTAMP)
848                                 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
849                         else
850                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
851                         sock_set_flag(sk, SOCK_RCVTSTAMP);
852                         sock_enable_timestamp(sk, SOCK_TIMESTAMP);
853                 } else {
854                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
855                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
856                 }
857                 break;
858 
859         case SO_TIMESTAMPING:
860                 if (val & ~SOF_TIMESTAMPING_MASK) {
861                         ret = -EINVAL;
862                         break;
863                 }
864 
865                 if (val & SOF_TIMESTAMPING_OPT_ID &&
866                     !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
867                         if (sk->sk_protocol == IPPROTO_TCP) {
868                                 if (sk->sk_state != TCP_ESTABLISHED) {
869                                         ret = -EINVAL;
870                                         break;
871                                 }
872                                 sk->sk_tskey = tcp_sk(sk)->snd_una;
873                         } else {
874                                 sk->sk_tskey = 0;
875                         }
876                 }
877                 sk->sk_tsflags = val;
878                 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
879                         sock_enable_timestamp(sk,
880                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
881                 else
882                         sock_disable_timestamp(sk,
883                                                (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
884                 break;
885 
886         case SO_RCVLOWAT:
887                 if (val < 0)
888                         val = INT_MAX;
889                 sk->sk_rcvlowat = val ? : 1;
890                 break;
891 
892         case SO_RCVTIMEO:
893                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
894                 break;
895 
896         case SO_SNDTIMEO:
897                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
898                 break;
899 
900         case SO_ATTACH_FILTER:
901                 ret = -EINVAL;
902                 if (optlen == sizeof(struct sock_fprog)) {
903                         struct sock_fprog fprog;
904 
905                         ret = -EFAULT;
906                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
907                                 break;
908 
909                         ret = sk_attach_filter(&fprog, sk);
910                 }
911                 break;
912 
913         case SO_ATTACH_BPF:
914                 ret = -EINVAL;
915                 if (optlen == sizeof(u32)) {
916                         u32 ufd;
917 
918                         ret = -EFAULT;
919                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
920                                 break;
921 
922                         ret = sk_attach_bpf(ufd, sk);
923                 }
924                 break;
925 
926         case SO_DETACH_FILTER:
927                 ret = sk_detach_filter(sk);
928                 break;
929 
930         case SO_LOCK_FILTER:
931                 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
932                         ret = -EPERM;
933                 else
934                         sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
935                 break;
936 
937         case SO_PASSSEC:
938                 if (valbool)
939                         set_bit(SOCK_PASSSEC, &sock->flags);
940                 else
941                         clear_bit(SOCK_PASSSEC, &sock->flags);
942                 break;
943         case SO_MARK:
944                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
945                         ret = -EPERM;
946                 else
947                         sk->sk_mark = val;
948                 break;
949 
950                 /* We implement the SO_SNDLOWAT etc to
951                    not be settable (1003.1g 5.3) */
952         case SO_RXQ_OVFL:
953                 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
954                 break;
955 
956         case SO_WIFI_STATUS:
957                 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
958                 break;
959 
960         case SO_PEEK_OFF:
961                 if (sock->ops->set_peek_off)
962                         ret = sock->ops->set_peek_off(sk, val);
963                 else
964                         ret = -EOPNOTSUPP;
965                 break;
966 
967         case SO_NOFCS:
968                 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
969                 break;
970 
971         case SO_SELECT_ERR_QUEUE:
972                 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
973                 break;
974 
975 #ifdef CONFIG_NET_RX_BUSY_POLL
976         case SO_BUSY_POLL:
977                 /* allow unprivileged users to decrease the value */
978                 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
979                         ret = -EPERM;
980                 else {
981                         if (val < 0)
982                                 ret = -EINVAL;
983                         else
984                                 sk->sk_ll_usec = val;
985                 }
986                 break;
987 #endif
988 
989         case SO_MAX_PACING_RATE:
990                 sk->sk_max_pacing_rate = val;
991                 sk->sk_pacing_rate = min(sk->sk_pacing_rate,
992                                          sk->sk_max_pacing_rate);
993                 break;
994 
995         default:
996                 ret = -ENOPROTOOPT;
997                 break;
998         }
999         release_sock(sk);
1000         return ret;
1001 }
1002 EXPORT_SYMBOL(sock_setsockopt);
1003 
1004 
1005 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1006                           struct ucred *ucred)
1007 {
1008         ucred->pid = pid_vnr(pid);
1009         ucred->uid = ucred->gid = -1;
1010         if (cred) {
1011                 struct user_namespace *current_ns = current_user_ns();
1012 
1013                 ucred->uid = from_kuid_munged(current_ns, cred->euid);
1014                 ucred->gid = from_kgid_munged(current_ns, cred->egid);
1015         }
1016 }
1017 
1018 int sock_getsockopt(struct socket *sock, int level, int optname,
1019                     char __user *optval, int __user *optlen)
1020 {
1021         struct sock *sk = sock->sk;
1022 
1023         union {
1024                 int val;
1025                 struct linger ling;
1026                 struct timeval tm;
1027         } v;
1028 
1029         int lv = sizeof(int);
1030         int len;
1031 
1032         if (get_user(len, optlen))
1033                 return -EFAULT;
1034         if (len < 0)
1035                 return -EINVAL;
1036 
1037         memset(&v, 0, sizeof(v));
1038 
1039         switch (optname) {
1040         case SO_DEBUG:
1041                 v.val = sock_flag(sk, SOCK_DBG);
1042                 break;
1043 
1044         case SO_DONTROUTE:
1045                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
1046                 break;
1047 
1048         case SO_BROADCAST:
1049                 v.val = sock_flag(sk, SOCK_BROADCAST);
1050                 break;
1051 
1052         case SO_SNDBUF:
1053                 v.val = sk->sk_sndbuf;
1054                 break;
1055 
1056         case SO_RCVBUF:
1057                 v.val = sk->sk_rcvbuf;
1058                 break;
1059 
1060         case SO_REUSEADDR:
1061                 v.val = sk->sk_reuse;
1062                 break;
1063 
1064         case SO_REUSEPORT:
1065                 v.val = sk->sk_reuseport;
1066                 break;
1067 
1068         case SO_KEEPALIVE:
1069                 v.val = sock_flag(sk, SOCK_KEEPOPEN);
1070                 break;
1071 
1072         case SO_TYPE:
1073                 v.val = sk->sk_type;
1074                 break;
1075 
1076         case SO_PROTOCOL:
1077                 v.val = sk->sk_protocol;
1078                 break;
1079 
1080         case SO_DOMAIN:
1081                 v.val = sk->sk_family;
1082                 break;
1083 
1084         case SO_ERROR:
1085                 v.val = -sock_error(sk);
1086                 if (v.val == 0)
1087                         v.val = xchg(&sk->sk_err_soft, 0);
1088                 break;
1089 
1090         case SO_OOBINLINE:
1091                 v.val = sock_flag(sk, SOCK_URGINLINE);
1092                 break;
1093 
1094         case SO_NO_CHECK:
1095                 v.val = sk->sk_no_check_tx;
1096                 break;
1097 
1098         case SO_PRIORITY:
1099                 v.val = sk->sk_priority;
1100                 break;
1101 
1102         case SO_LINGER:
1103                 lv              = sizeof(v.ling);
1104                 v.ling.l_onoff  = sock_flag(sk, SOCK_LINGER);
1105                 v.ling.l_linger = sk->sk_lingertime / HZ;
1106                 break;
1107 
1108         case SO_BSDCOMPAT:
1109                 sock_warn_obsolete_bsdism("getsockopt");
1110                 break;
1111 
1112         case SO_TIMESTAMP:
1113                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1114                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1115                 break;
1116 
1117         case SO_TIMESTAMPNS:
1118                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1119                 break;
1120 
1121         case SO_TIMESTAMPING:
1122                 v.val = sk->sk_tsflags;
1123                 break;
1124 
1125         case SO_RCVTIMEO:
1126                 lv = sizeof(struct timeval);
1127                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1128                         v.tm.tv_sec = 0;
1129                         v.tm.tv_usec = 0;
1130                 } else {
1131                         v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1132                         v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1133                 }
1134                 break;
1135 
1136         case SO_SNDTIMEO:
1137                 lv = sizeof(struct timeval);
1138                 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1139                         v.tm.tv_sec = 0;
1140                         v.tm.tv_usec = 0;
1141                 } else {
1142                         v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1143                         v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1144                 }
1145                 break;
1146 
1147         case SO_RCVLOWAT:
1148                 v.val = sk->sk_rcvlowat;
1149                 break;
1150 
1151         case SO_SNDLOWAT:
1152                 v.val = 1;
1153                 break;
1154 
1155         case SO_PASSCRED:
1156                 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1157                 break;
1158 
1159         case SO_PEERCRED:
1160         {
1161                 struct ucred peercred;
1162                 if (len > sizeof(peercred))
1163                         len = sizeof(peercred);
1164                 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1165                 if (copy_to_user(optval, &peercred, len))
1166                         return -EFAULT;
1167                 goto lenout;
1168         }
1169 
1170         case SO_PEERNAME:
1171         {
1172                 char address[128];
1173 
1174                 if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1175                         return -ENOTCONN;
1176                 if (lv < len)
1177                         return -EINVAL;
1178                 if (copy_to_user(optval, address, len))
1179                         return -EFAULT;
1180                 goto lenout;
1181         }
1182 
1183         /* Dubious BSD thing... Probably nobody even uses it, but
1184          * the UNIX standard wants it for whatever reason... -DaveM
1185          */
1186         case SO_ACCEPTCONN:
1187                 v.val = sk->sk_state == TCP_LISTEN;
1188                 break;
1189 
1190         case SO_PASSSEC:
1191                 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1192                 break;
1193 
1194         case SO_PEERSEC:
1195                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1196 
1197         case SO_MARK:
1198                 v.val = sk->sk_mark;
1199                 break;
1200 
1201         case SO_RXQ_OVFL:
1202                 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1203                 break;
1204 
1205         case SO_WIFI_STATUS:
1206                 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1207                 break;
1208 
1209         case SO_PEEK_OFF:
1210                 if (!sock->ops->set_peek_off)
1211                         return -EOPNOTSUPP;
1212 
1213                 v.val = sk->sk_peek_off;
1214                 break;
1215         case SO_NOFCS:
1216                 v.val = sock_flag(sk, SOCK_NOFCS);
1217                 break;
1218 
1219         case SO_BINDTODEVICE:
1220                 return sock_getbindtodevice(sk, optval, optlen, len);
1221 
1222         case SO_GET_FILTER:
1223                 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1224                 if (len < 0)
1225                         return len;
1226 
1227                 goto lenout;
1228 
1229         case SO_LOCK_FILTER:
1230                 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1231                 break;
1232 
1233         case SO_BPF_EXTENSIONS:
1234                 v.val = bpf_tell_extensions();
1235                 break;
1236 
1237         case SO_SELECT_ERR_QUEUE:
1238                 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1239                 break;
1240 
1241 #ifdef CONFIG_NET_RX_BUSY_POLL
1242         case SO_BUSY_POLL:
1243                 v.val = sk->sk_ll_usec;
1244                 break;
1245 #endif
1246 
1247         case SO_MAX_PACING_RATE:
1248                 v.val = sk->sk_max_pacing_rate;
1249                 break;
1250 
1251         case SO_INCOMING_CPU:
1252                 v.val = sk->sk_incoming_cpu;
1253                 break;
1254 
1255         default:
1256                 return -ENOPROTOOPT;
1257         }
1258 
1259         if (len > lv)
1260                 len = lv;
1261         if (copy_to_user(optval, &v, len))
1262                 return -EFAULT;
1263 lenout:
1264         if (put_user(len, optlen))
1265                 return -EFAULT;
1266         return 0;
1267 }
1268 
1269 /*
1270  * Initialize an sk_lock.
1271  *
1272  * (We also register the sk_lock with the lock validator.)
1273  */
1274 static inline void sock_lock_init(struct sock *sk)
1275 {
1276         sock_lock_init_class_and_name(sk,
1277                         af_family_slock_key_strings[sk->sk_family],
1278                         af_family_slock_keys + sk->sk_family,
1279                         af_family_key_strings[sk->sk_family],
1280                         af_family_keys + sk->sk_family);
1281 }
1282 
1283 /*
1284  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1285  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1286  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1287  */
1288 static void sock_copy(struct sock *nsk, const struct sock *osk)
1289 {
1290 #ifdef CONFIG_SECURITY_NETWORK
1291         void *sptr = nsk->sk_security;
1292 #endif
1293         memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1294 
1295         memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1296                osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1297 
1298 #ifdef CONFIG_SECURITY_NETWORK
1299         nsk->sk_security = sptr;
1300         security_sk_clone(osk, nsk);
1301 #endif
1302 }
1303 
1304 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1305 {
1306         unsigned long nulls1, nulls2;
1307 
1308         nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1309         nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1310         if (nulls1 > nulls2)
1311                 swap(nulls1, nulls2);
1312 
1313         if (nulls1 != 0)
1314                 memset((char *)sk, 0, nulls1);
1315         memset((char *)sk + nulls1 + sizeof(void *), 0,
1316                nulls2 - nulls1 - sizeof(void *));
1317         memset((char *)sk + nulls2 + sizeof(void *), 0,
1318                size - nulls2 - sizeof(void *));
1319 }
1320 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1321 
1322 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1323                 int family)
1324 {
1325         struct sock *sk;
1326         struct kmem_cache *slab;
1327 
1328         slab = prot->slab;
1329         if (slab != NULL) {
1330                 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1331                 if (!sk)
1332                         return sk;
1333                 if (priority & __GFP_ZERO) {
1334                         if (prot->clear_sk)
1335                                 prot->clear_sk(sk, prot->obj_size);
1336                         else
1337                                 sk_prot_clear_nulls(sk, prot->obj_size);
1338                 }
1339         } else
1340                 sk = kmalloc(prot->obj_size, priority);
1341 
1342         if (sk != NULL) {
1343                 kmemcheck_annotate_bitfield(sk, flags);
1344 
1345                 if (security_sk_alloc(sk, family, priority))
1346                         goto out_free;
1347 
1348                 if (!try_module_get(prot->owner))
1349                         goto out_free_sec;
1350                 sk_tx_queue_clear(sk);
1351         }
1352 
1353         return sk;
1354 
1355 out_free_sec:
1356         security_sk_free(sk);
1357 out_free:
1358         if (slab != NULL)
1359                 kmem_cache_free(slab, sk);
1360         else
1361                 kfree(sk);
1362         return NULL;
1363 }
1364 
1365 static void sk_prot_free(struct proto *prot, struct sock *sk)
1366 {
1367         struct kmem_cache *slab;
1368         struct module *owner;
1369 
1370         owner = prot->owner;
1371         slab = prot->slab;
1372 
1373         security_sk_free(sk);
1374         if (slab != NULL)
1375                 kmem_cache_free(slab, sk);
1376         else
1377                 kfree(sk);
1378         module_put(owner);
1379 }
1380 
1381 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
1382 void sock_update_netprioidx(struct sock *sk)
1383 {
1384         if (in_interrupt())
1385                 return;
1386 
1387         sk->sk_cgrp_prioidx = task_netprioidx(current);
1388 }
1389 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1390 #endif
1391 
1392 /**
1393  *      sk_alloc - All socket objects are allocated here
1394  *      @net: the applicable net namespace
1395  *      @family: protocol family
1396  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1397  *      @prot: struct proto associated with this new sock instance
1398  */
1399 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1400                       struct proto *prot)
1401 {
1402         struct sock *sk;
1403 
1404         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1405         if (sk) {
1406                 sk->sk_family = family;
1407                 /*
1408                  * See comment in struct sock definition to understand
1409                  * why we need sk_prot_creator -acme
1410                  */
1411                 sk->sk_prot = sk->sk_prot_creator = prot;
1412                 sock_lock_init(sk);
1413                 sock_net_set(sk, get_net(net));
1414                 atomic_set(&sk->sk_wmem_alloc, 1);
1415 
1416                 sock_update_classid(sk);
1417                 sock_update_netprioidx(sk);
1418         }
1419 
1420         return sk;
1421 }
1422 EXPORT_SYMBOL(sk_alloc);
1423 
1424 static void __sk_free(struct sock *sk)
1425 {
1426         struct sk_filter *filter;
1427 
1428         if (sk->sk_destruct)
1429                 sk->sk_destruct(sk);
1430 
1431         filter = rcu_dereference_check(sk->sk_filter,
1432                                        atomic_read(&sk->sk_wmem_alloc) == 0);
1433         if (filter) {
1434                 sk_filter_uncharge(sk, filter);
1435                 RCU_INIT_POINTER(sk->sk_filter, NULL);
1436         }
1437 
1438         sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1439 
1440         if (atomic_read(&sk->sk_omem_alloc))
1441                 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1442                          __func__, atomic_read(&sk->sk_omem_alloc));
1443 
1444         if (sk->sk_peer_cred)
1445                 put_cred(sk->sk_peer_cred);
1446         put_pid(sk->sk_peer_pid);
1447         put_net(sock_net(sk));
1448         sk_prot_free(sk->sk_prot_creator, sk);
1449 }
1450 
1451 void sk_free(struct sock *sk)
1452 {
1453         /*
1454          * We subtract one from sk_wmem_alloc and can know if
1455          * some packets are still in some tx queue.
1456          * If not null, sock_wfree() will call __sk_free(sk) later
1457          */
1458         if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1459                 __sk_free(sk);
1460 }
1461 EXPORT_SYMBOL(sk_free);
1462 
1463 /*
1464  * Last sock_put should drop reference to sk->sk_net. It has already
1465  * been dropped in sk_change_net. Taking reference to stopping namespace
1466  * is not an option.
1467  * Take reference to a socket to remove it from hash _alive_ and after that
1468  * destroy it in the context of init_net.
1469  */
1470 void sk_release_kernel(struct sock *sk)
1471 {
1472         if (sk == NULL || sk->sk_socket == NULL)
1473                 return;
1474 
1475         sock_hold(sk);
1476         sock_release(sk->sk_socket);
1477         release_net(sock_net(sk));
1478         sock_net_set(sk, get_net(&init_net));
1479         sock_put(sk);
1480 }
1481 EXPORT_SYMBOL(sk_release_kernel);
1482 
1483 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1484 {
1485         if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1486                 sock_update_memcg(newsk);
1487 }
1488 
1489 /**
1490  *      sk_clone_lock - clone a socket, and lock its clone
1491  *      @sk: the socket to clone
1492  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1493  *
1494  *      Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1495  */
1496 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1497 {
1498         struct sock *newsk;
1499         bool is_charged = true;
1500 
1501         newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1502         if (newsk != NULL) {
1503                 struct sk_filter *filter;
1504 
1505                 sock_copy(newsk, sk);
1506 
1507                 /* SANITY */
1508                 get_net(sock_net(newsk));
1509                 sk_node_init(&newsk->sk_node);
1510                 sock_lock_init(newsk);
1511                 bh_lock_sock(newsk);
1512                 newsk->sk_backlog.head  = newsk->sk_backlog.tail = NULL;
1513                 newsk->sk_backlog.len = 0;
1514 
1515                 atomic_set(&newsk->sk_rmem_alloc, 0);
1516                 /*
1517                  * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1518                  */
1519                 atomic_set(&newsk->sk_wmem_alloc, 1);
1520                 atomic_set(&newsk->sk_omem_alloc, 0);
1521                 skb_queue_head_init(&newsk->sk_receive_queue);
1522                 skb_queue_head_init(&newsk->sk_write_queue);
1523 
1524                 spin_lock_init(&newsk->sk_dst_lock);
1525                 rwlock_init(&newsk->sk_callback_lock);
1526                 lockdep_set_class_and_name(&newsk->sk_callback_lock,
1527                                 af_callback_keys + newsk->sk_family,
1528                                 af_family_clock_key_strings[newsk->sk_family]);
1529 
1530                 newsk->sk_dst_cache     = NULL;
1531                 newsk->sk_wmem_queued   = 0;
1532                 newsk->sk_forward_alloc = 0;
1533                 newsk->sk_send_head     = NULL;
1534                 newsk->sk_userlocks     = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1535 
1536                 sock_reset_flag(newsk, SOCK_DONE);
1537                 skb_queue_head_init(&newsk->sk_error_queue);
1538 
1539                 filter = rcu_dereference_protected(newsk->sk_filter, 1);
1540                 if (filter != NULL)
1541                         /* though it's an empty new sock, the charging may fail
1542                          * if sysctl_optmem_max was changed between creation of
1543                          * original socket and cloning
1544                          */
1545                         is_charged = sk_filter_charge(newsk, filter);
1546 
1547                 if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk))) {
1548                         /* It is still raw copy of parent, so invalidate
1549                          * destructor and make plain sk_free() */
1550                         newsk->sk_destruct = NULL;
1551                         bh_unlock_sock(newsk);
1552                         sk_free(newsk);
1553                         newsk = NULL;
1554                         goto out;
1555                 }
1556 
1557                 newsk->sk_err      = 0;
1558                 newsk->sk_priority = 0;
1559                 newsk->sk_incoming_cpu = raw_smp_processor_id();
1560                 /*
1561                  * Before updating sk_refcnt, we must commit prior changes to memory
1562                  * (Documentation/RCU/rculist_nulls.txt for details)
1563                  */
1564                 smp_wmb();
1565                 atomic_set(&newsk->sk_refcnt, 2);
1566 
1567                 /*
1568                  * Increment the counter in the same struct proto as the master
1569                  * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1570                  * is the same as sk->sk_prot->socks, as this field was copied
1571                  * with memcpy).
1572                  *
1573                  * This _changes_ the previous behaviour, where
1574                  * tcp_create_openreq_child always was incrementing the
1575                  * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1576                  * to be taken into account in all callers. -acme
1577                  */
1578                 sk_refcnt_debug_inc(newsk);
1579                 sk_set_socket(newsk, NULL);
1580                 newsk->sk_wq = NULL;
1581 
1582                 sk_update_clone(sk, newsk);
1583 
1584                 if (newsk->sk_prot->sockets_allocated)
1585                         sk_sockets_allocated_inc(newsk);
1586 
1587                 if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1588                         net_enable_timestamp();
1589         }
1590 out:
1591         return newsk;
1592 }
1593 EXPORT_SYMBOL_GPL(sk_clone_lock);
1594 
1595 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1596 {
1597         __sk_dst_set(sk, dst);
1598         sk->sk_route_caps = dst->dev->features;
1599         if (sk->sk_route_caps & NETIF_F_GSO)
1600                 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1601         sk->sk_route_caps &= ~sk->sk_route_nocaps;
1602         if (sk_can_gso(sk)) {
1603                 if (dst->header_len) {
1604                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1605                 } else {
1606                         sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1607                         sk->sk_gso_max_size = dst->dev->gso_max_size;
1608                         sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1609                 }
1610         }
1611 }
1612 EXPORT_SYMBOL_GPL(sk_setup_caps);
1613 
1614 /*
1615  *      Simple resource managers for sockets.
1616  */
1617 
1618 
1619 /*
1620  * Write buffer destructor automatically called from kfree_skb.
1621  */
1622 void sock_wfree(struct sk_buff *skb)
1623 {
1624         struct sock *sk = skb->sk;
1625         unsigned int len = skb->truesize;
1626 
1627         if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1628                 /*
1629                  * Keep a reference on sk_wmem_alloc, this will be released
1630                  * after sk_write_space() call
1631                  */
1632                 atomic_sub(len - 1, &sk->sk_wmem_alloc);
1633                 sk->sk_write_space(sk);
1634                 len = 1;
1635         }
1636         /*
1637          * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1638          * could not do because of in-flight packets
1639          */
1640         if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1641                 __sk_free(sk);
1642 }
1643 EXPORT_SYMBOL(sock_wfree);
1644 
1645 void skb_orphan_partial(struct sk_buff *skb)
1646 {
1647         /* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1648          * so we do not completely orphan skb, but transfert all
1649          * accounted bytes but one, to avoid unexpected reorders.
1650          */
1651         if (skb->destructor == sock_wfree
1652 #ifdef CONFIG_INET
1653             || skb->destructor == tcp_wfree
1654 #endif
1655                 ) {
1656                 atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1657                 skb->truesize = 1;
1658         } else {
1659                 skb_orphan(skb);
1660         }
1661 }
1662 EXPORT_SYMBOL(skb_orphan_partial);
1663 
1664 /*
1665  * Read buffer destructor automatically called from kfree_skb.
1666  */
1667 void sock_rfree(struct sk_buff *skb)
1668 {
1669         struct sock *sk = skb->sk;
1670         unsigned int len = skb->truesize;
1671 
1672         atomic_sub(len, &sk->sk_rmem_alloc);
1673         sk_mem_uncharge(sk, len);
1674 }
1675 EXPORT_SYMBOL(sock_rfree);
1676 
1677 /*
1678  * Buffer destructor for skbs that are not used directly in read or write
1679  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1680  */
1681 void sock_efree(struct sk_buff *skb)
1682 {
1683         sock_put(skb->sk);
1684 }
1685 EXPORT_SYMBOL(sock_efree);
1686 
1687 #ifdef CONFIG_INET
1688 void sock_edemux(struct sk_buff *skb)
1689 {
1690         struct sock *sk = skb->sk;
1691 
1692         if (sk->sk_state == TCP_TIME_WAIT)
1693                 inet_twsk_put(inet_twsk(sk));
1694         else
1695                 sock_put(sk);
1696 }
1697 EXPORT_SYMBOL(sock_edemux);
1698 #endif
1699 
1700 kuid_t sock_i_uid(struct sock *sk)
1701 {
1702         kuid_t uid;
1703 
1704         read_lock_bh(&sk->sk_callback_lock);
1705         uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1706         read_unlock_bh(&sk->sk_callback_lock);
1707         return uid;
1708 }
1709 EXPORT_SYMBOL(sock_i_uid);
1710 
1711 unsigned long sock_i_ino(struct sock *sk)
1712 {
1713         unsigned long ino;
1714 
1715         read_lock_bh(&sk->sk_callback_lock);
1716         ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1717         read_unlock_bh(&sk->sk_callback_lock);
1718         return ino;
1719 }
1720 EXPORT_SYMBOL(sock_i_ino);
1721 
1722 /*
1723  * Allocate a skb from the socket's send buffer.
1724  */
1725 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1726                              gfp_t priority)
1727 {
1728         if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1729                 struct sk_buff *skb = alloc_skb(size, priority);
1730                 if (skb) {
1731                         skb_set_owner_w(skb, sk);
1732                         return skb;
1733                 }
1734         }
1735         return NULL;
1736 }
1737 EXPORT_SYMBOL(sock_wmalloc);
1738 
1739 /*
1740  * Allocate a memory block from the socket's option memory buffer.
1741  */
1742 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1743 {
1744         if ((unsigned int)size <= sysctl_optmem_max &&
1745             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1746                 void *mem;
1747                 /* First do the add, to avoid the race if kmalloc
1748                  * might sleep.
1749                  */
1750                 atomic_add(size, &sk->sk_omem_alloc);
1751                 mem = kmalloc(size, priority);
1752                 if (mem)
1753                         return mem;
1754                 atomic_sub(size, &sk->sk_omem_alloc);
1755         }
1756         return NULL;
1757 }
1758 EXPORT_SYMBOL(sock_kmalloc);
1759 
1760 /* Free an option memory block. Note, we actually want the inline
1761  * here as this allows gcc to detect the nullify and fold away the
1762  * condition entirely.
1763  */
1764 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
1765                                   const bool nullify)
1766 {
1767         if (WARN_ON_ONCE(!mem))
1768                 return;
1769         if (nullify)
1770                 kzfree(mem);
1771         else
1772                 kfree(mem);
1773         atomic_sub(size, &sk->sk_omem_alloc);
1774 }
1775 
1776 void sock_kfree_s(struct sock *sk, void *mem, int size)
1777 {
1778         __sock_kfree_s(sk, mem, size, false);
1779 }
1780 EXPORT_SYMBOL(sock_kfree_s);
1781 
1782 void sock_kzfree_s(struct sock *sk, void *mem, int size)
1783 {
1784         __sock_kfree_s(sk, mem, size, true);
1785 }
1786 EXPORT_SYMBOL(sock_kzfree_s);
1787 
1788 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1789    I think, these locks should be removed for datagram sockets.
1790  */
1791 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1792 {
1793         DEFINE_WAIT(wait);
1794 
1795         clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1796         for (;;) {
1797                 if (!timeo)
1798                         break;
1799                 if (signal_pending(current))
1800                         break;
1801                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1802                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1803                 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1804                         break;
1805                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1806                         break;
1807                 if (sk->sk_err)
1808                         break;
1809                 timeo = schedule_timeout(timeo);
1810         }
1811         finish_wait(sk_sleep(sk), &wait);
1812         return timeo;
1813 }
1814 
1815 
1816 /*
1817  *      Generic send/receive buffer handlers
1818  */
1819 
1820 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1821                                      unsigned long data_len, int noblock,
1822                                      int *errcode, int max_page_order)
1823 {
1824         struct sk_buff *skb;
1825         long timeo;
1826         int err;
1827 
1828         timeo = sock_sndtimeo(sk, noblock);
1829         for (;;) {
1830                 err = sock_error(sk);
1831                 if (err != 0)
1832                         goto failure;
1833 
1834                 err = -EPIPE;
1835                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1836                         goto failure;
1837 
1838                 if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
1839                         break;
1840 
1841                 set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1842                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1843                 err = -EAGAIN;
1844                 if (!timeo)
1845                         goto failure;
1846                 if (signal_pending(current))
1847                         goto interrupted;
1848                 timeo = sock_wait_for_wmem(sk, timeo);
1849         }
1850         skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
1851                                    errcode, sk->sk_allocation);
1852         if (skb)
1853                 skb_set_owner_w(skb, sk);
1854         return skb;
1855 
1856 interrupted:
1857         err = sock_intr_errno(timeo);
1858 failure:
1859         *errcode = err;
1860         return NULL;
1861 }
1862 EXPORT_SYMBOL(sock_alloc_send_pskb);
1863 
1864 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1865                                     int noblock, int *errcode)
1866 {
1867         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1868 }
1869 EXPORT_SYMBOL(sock_alloc_send_skb);
1870 
1871 /* On 32bit arches, an skb frag is limited to 2^15 */
1872 #define SKB_FRAG_PAGE_ORDER     get_order(32768)
1873 
1874 /**
1875  * skb_page_frag_refill - check that a page_frag contains enough room
1876  * @sz: minimum size of the fragment we want to get
1877  * @pfrag: pointer to page_frag
1878  * @gfp: priority for memory allocation
1879  *
1880  * Note: While this allocator tries to use high order pages, there is
1881  * no guarantee that allocations succeed. Therefore, @sz MUST be
1882  * less or equal than PAGE_SIZE.
1883  */
1884 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
1885 {
1886         if (pfrag->page) {
1887                 if (atomic_read(&pfrag->page->_count) == 1) {
1888                         pfrag->offset = 0;
1889                         return true;
1890                 }
1891                 if (pfrag->offset + sz <= pfrag->size)
1892                         return true;
1893                 put_page(pfrag->page);
1894         }
1895 
1896         pfrag->offset = 0;
1897         if (SKB_FRAG_PAGE_ORDER) {
1898                 pfrag->page = alloc_pages(gfp | __GFP_COMP |
1899                                           __GFP_NOWARN | __GFP_NORETRY,
1900                                           SKB_FRAG_PAGE_ORDER);
1901                 if (likely(pfrag->page)) {
1902                         pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
1903                         return true;
1904                 }
1905         }
1906         pfrag->page = alloc_page(gfp);
1907         if (likely(pfrag->page)) {
1908                 pfrag->size = PAGE_SIZE;
1909                 return true;
1910         }
1911         return false;
1912 }
1913 EXPORT_SYMBOL(skb_page_frag_refill);
1914 
1915 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1916 {
1917         if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1918                 return true;
1919 
1920         sk_enter_memory_pressure(sk);
1921         sk_stream_moderate_sndbuf(sk);
1922         return false;
1923 }
1924 EXPORT_SYMBOL(sk_page_frag_refill);
1925 
1926 static void __lock_sock(struct sock *sk)
1927         __releases(&sk->sk_lock.slock)
1928         __acquires(&sk->sk_lock.slock)
1929 {
1930         DEFINE_WAIT(wait);
1931 
1932         for (;;) {
1933                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1934                                         TASK_UNINTERRUPTIBLE);
1935                 spin_unlock_bh(&sk->sk_lock.slock);
1936                 schedule();
1937                 spin_lock_bh(&sk->sk_lock.slock);
1938                 if (!sock_owned_by_user(sk))
1939                         break;
1940         }
1941         finish_wait(&sk->sk_lock.wq, &wait);
1942 }
1943 
1944 static void __release_sock(struct sock *sk)
1945         __releases(&sk->sk_lock.slock)
1946         __acquires(&sk->sk_lock.slock)
1947 {
1948         struct sk_buff *skb = sk->sk_backlog.head;
1949 
1950         do {
1951                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1952                 bh_unlock_sock(sk);
1953 
1954                 do {
1955                         struct sk_buff *next = skb->next;
1956 
1957                         prefetch(next);
1958                         WARN_ON_ONCE(skb_dst_is_noref(skb));
1959                         skb->next = NULL;
1960                         sk_backlog_rcv(sk, skb);
1961 
1962                         /*
1963                          * We are in process context here with softirqs
1964                          * disabled, use cond_resched_softirq() to preempt.
1965                          * This is safe to do because we've taken the backlog
1966                          * queue private:
1967                          */
1968                         cond_resched_softirq();
1969 
1970                         skb = next;
1971                 } while (skb != NULL);
1972 
1973                 bh_lock_sock(sk);
1974         } while ((skb = sk->sk_backlog.head) != NULL);
1975 
1976         /*
1977          * Doing the zeroing here guarantee we can not loop forever
1978          * while a wild producer attempts to flood us.
1979          */
1980         sk->sk_backlog.len = 0;
1981 }
1982 
1983 /**
1984  * sk_wait_data - wait for data to arrive at sk_receive_queue
1985  * @sk:    sock to wait on
1986  * @timeo: for how long
1987  *
1988  * Now socket state including sk->sk_err is changed only under lock,
1989  * hence we may omit checks after joining wait queue.
1990  * We check receive queue before schedule() only as optimization;
1991  * it is very likely that release_sock() added new data.
1992  */
1993 int sk_wait_data(struct sock *sk, long *timeo)
1994 {
1995         int rc;
1996         DEFINE_WAIT(wait);
1997 
1998         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1999         set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
2000         rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
2001         clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
2002         finish_wait(sk_sleep(sk), &wait);
2003         return rc;
2004 }
2005 EXPORT_SYMBOL(sk_wait_data);
2006 
2007 /**
2008  *      __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2009  *      @sk: socket
2010  *      @size: memory size to allocate
2011  *      @kind: allocation type
2012  *
2013  *      If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2014  *      rmem allocation. This function assumes that protocols which have
2015  *      memory_pressure use sk_wmem_queued as write buffer accounting.
2016  */
2017 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2018 {
2019         struct proto *prot = sk->sk_prot;
2020         int amt = sk_mem_pages(size);
2021         long allocated;
2022         int parent_status = UNDER_LIMIT;
2023 
2024         sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
2025 
2026         allocated = sk_memory_allocated_add(sk, amt, &parent_status);
2027 
2028         /* Under limit. */
2029         if (parent_status == UNDER_LIMIT &&
2030                         allocated <= sk_prot_mem_limits(sk, 0)) {
2031                 sk_leave_memory_pressure(sk);
2032                 return 1;
2033         }
2034 
2035         /* Under pressure. (we or our parents) */
2036         if ((parent_status > SOFT_LIMIT) ||
2037                         allocated > sk_prot_mem_limits(sk, 1))
2038                 sk_enter_memory_pressure(sk);
2039 
2040         /* Over hard limit (we or our parents) */
2041         if ((parent_status == OVER_LIMIT) ||
2042                         (allocated > sk_prot_mem_limits(sk, 2)))
2043                 goto suppress_allocation;
2044 
2045         /* guarantee minimum buffer size under pressure */
2046         if (kind == SK_MEM_RECV) {
2047                 if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2048                         return 1;
2049 
2050         } else { /* SK_MEM_SEND */
2051                 if (sk->sk_type == SOCK_STREAM) {
2052                         if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2053                                 return 1;
2054                 } else if (atomic_read(&sk->sk_wmem_alloc) <
2055                            prot->sysctl_wmem[0])
2056                                 return 1;
2057         }
2058 
2059         if (sk_has_memory_pressure(sk)) {
2060                 int alloc;
2061 
2062                 if (!sk_under_memory_pressure(sk))
2063                         return 1;
2064                 alloc = sk_sockets_allocated_read_positive(sk);
2065                 if (sk_prot_mem_limits(sk, 2) > alloc *
2066                     sk_mem_pages(sk->sk_wmem_queued +
2067                                  atomic_read(&sk->sk_rmem_alloc) +
2068                                  sk->sk_forward_alloc))
2069                         return 1;
2070         }
2071 
2072 suppress_allocation:
2073 
2074         if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2075                 sk_stream_moderate_sndbuf(sk);
2076 
2077                 /* Fail only if socket is _under_ its sndbuf.
2078                  * In this case we cannot block, so that we have to fail.
2079                  */
2080                 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2081                         return 1;
2082         }
2083 
2084         trace_sock_exceed_buf_limit(sk, prot, allocated);
2085 
2086         /* Alas. Undo changes. */
2087         sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2088 
2089         sk_memory_allocated_sub(sk, amt);
2090 
2091         return 0;
2092 }
2093 EXPORT_SYMBOL(__sk_mem_schedule);
2094 
2095 /**
2096  *      __sk_reclaim - reclaim memory_allocated
2097  *      @sk: socket
2098  */
2099 void __sk_mem_reclaim(struct sock *sk)
2100 {
2101         sk_memory_allocated_sub(sk,
2102                                 sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
2103         sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
2104 
2105         if (sk_under_memory_pressure(sk) &&
2106             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2107                 sk_leave_memory_pressure(sk);
2108 }
2109 EXPORT_SYMBOL(__sk_mem_reclaim);
2110 
2111 
2112 /*
2113  * Set of default routines for initialising struct proto_ops when
2114  * the protocol does not support a particular function. In certain
2115  * cases where it makes no sense for a protocol to have a "do nothing"
2116  * function, some default processing is provided.
2117  */
2118 
2119 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2120 {
2121         return -EOPNOTSUPP;
2122 }
2123 EXPORT_SYMBOL(sock_no_bind);
2124 
2125 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2126                     int len, int flags)
2127 {
2128         return -EOPNOTSUPP;
2129 }
2130 EXPORT_SYMBOL(sock_no_connect);
2131 
2132 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2133 {
2134         return -EOPNOTSUPP;
2135 }
2136 EXPORT_SYMBOL(sock_no_socketpair);
2137 
2138 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2139 {
2140         return -EOPNOTSUPP;
2141 }
2142 EXPORT_SYMBOL(sock_no_accept);
2143 
2144 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2145                     int *len, int peer)
2146 {
2147         return -EOPNOTSUPP;
2148 }
2149 EXPORT_SYMBOL(sock_no_getname);
2150 
2151 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2152 {
2153         return 0;
2154 }
2155 EXPORT_SYMBOL(sock_no_poll);
2156 
2157 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2158 {
2159         return -EOPNOTSUPP;
2160 }
2161 EXPORT_SYMBOL(sock_no_ioctl);
2162 
2163 int sock_no_listen(struct socket *sock, int backlog)
2164 {
2165         return -EOPNOTSUPP;
2166 }
2167 EXPORT_SYMBOL(sock_no_listen);
2168 
2169 int sock_no_shutdown(struct socket *sock, int how)
2170 {
2171         return -EOPNOTSUPP;
2172 }
2173 EXPORT_SYMBOL(sock_no_shutdown);
2174 
2175 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2176                     char __user *optval, unsigned int optlen)
2177 {
2178         return -EOPNOTSUPP;
2179 }
2180 EXPORT_SYMBOL(sock_no_setsockopt);
2181 
2182 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2183                     char __user *optval, int __user *optlen)
2184 {
2185         return -EOPNOTSUPP;
2186 }
2187 EXPORT_SYMBOL(sock_no_getsockopt);
2188 
2189 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2190                     size_t len)
2191 {
2192         return -EOPNOTSUPP;
2193 }
2194 EXPORT_SYMBOL(sock_no_sendmsg);
2195 
2196 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2197                     size_t len, int flags)
2198 {
2199         return -EOPNOTSUPP;
2200 }
2201 EXPORT_SYMBOL(sock_no_recvmsg);
2202 
2203 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2204 {
2205         /* Mirror missing mmap method error code */
2206         return -ENODEV;
2207 }
2208 EXPORT_SYMBOL(sock_no_mmap);
2209 
2210 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2211 {
2212         ssize_t res;
2213         struct msghdr msg = {.msg_flags = flags};
2214         struct kvec iov;
2215         char *kaddr = kmap(page);
2216         iov.iov_base = kaddr + offset;
2217         iov.iov_len = size;
2218         res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2219         kunmap(page);
2220         return res;
2221 }
2222 EXPORT_SYMBOL(sock_no_sendpage);
2223 
2224 /*
2225  *      Default Socket Callbacks
2226  */
2227 
2228 static void sock_def_wakeup(struct sock *sk)
2229 {
2230         struct socket_wq *wq;
2231 
2232         rcu_read_lock();
2233         wq = rcu_dereference(sk->sk_wq);
2234         if (wq_has_sleeper(wq))
2235                 wake_up_interruptible_all(&wq->wait);
2236         rcu_read_unlock();
2237 }
2238 
2239 static void sock_def_error_report(struct sock *sk)
2240 {
2241         struct socket_wq *wq;
2242 
2243         rcu_read_lock();
2244         wq = rcu_dereference(sk->sk_wq);
2245         if (wq_has_sleeper(wq))
2246                 wake_up_interruptible_poll(&wq->wait, POLLERR);
2247         sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2248         rcu_read_unlock();
2249 }
2250 
2251 static void sock_def_readable(struct sock *sk)
2252 {
2253         struct socket_wq *wq;
2254 
2255         rcu_read_lock();
2256         wq = rcu_dereference(sk->sk_wq);
2257         if (wq_has_sleeper(wq))
2258                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2259                                                 POLLRDNORM | POLLRDBAND);
2260         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2261         rcu_read_unlock();
2262 }
2263 
2264 static void sock_def_write_space(struct sock *sk)
2265 {
2266         struct socket_wq *wq;
2267 
2268         rcu_read_lock();
2269 
2270         /* Do not wake up a writer until he can make "significant"
2271          * progress.  --DaveM
2272          */
2273         if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2274                 wq = rcu_dereference(sk->sk_wq);
2275                 if (wq_has_sleeper(wq))
2276                         wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2277                                                 POLLWRNORM | POLLWRBAND);
2278 
2279                 /* Should agree with poll, otherwise some programs break */
2280                 if (sock_writeable(sk))
2281                         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2282         }
2283 
2284         rcu_read_unlock();
2285 }
2286 
2287 static void sock_def_destruct(struct sock *sk)
2288 {
2289         kfree(sk->sk_protinfo);
2290 }
2291 
2292 void sk_send_sigurg(struct sock *sk)
2293 {
2294         if (sk->sk_socket && sk->sk_socket->file)
2295                 if (send_sigurg(&sk->sk_socket->file->f_owner))
2296                         sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2297 }
2298 EXPORT_SYMBOL(sk_send_sigurg);
2299 
2300 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2301                     unsigned long expires)
2302 {
2303         if (!mod_timer(timer, expires))
2304                 sock_hold(sk);
2305 }
2306 EXPORT_SYMBOL(sk_reset_timer);
2307 
2308 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2309 {
2310         if (del_timer(timer))
2311                 __sock_put(sk);
2312 }
2313 EXPORT_SYMBOL(sk_stop_timer);
2314 
2315 void sock_init_data(struct socket *sock, struct sock *sk)
2316 {
2317         skb_queue_head_init(&sk->sk_receive_queue);
2318         skb_queue_head_init(&sk->sk_write_queue);
2319         skb_queue_head_init(&sk->sk_error_queue);
2320 
2321         sk->sk_send_head        =       NULL;
2322 
2323         init_timer(&sk->sk_timer);
2324 
2325         sk->sk_allocation       =       GFP_KERNEL;
2326         sk->sk_rcvbuf           =       sysctl_rmem_default;
2327         sk->sk_sndbuf           =       sysctl_wmem_default;
2328         sk->sk_state            =       TCP_CLOSE;
2329         sk_set_socket(sk, sock);
2330 
2331         sock_set_flag(sk, SOCK_ZAPPED);
2332 
2333         if (sock) {
2334                 sk->sk_type     =       sock->type;
2335                 sk->sk_wq       =       sock->wq;
2336                 sock->sk        =       sk;
2337         } else
2338                 sk->sk_wq       =       NULL;
2339 
2340         spin_lock_init(&sk->sk_dst_lock);
2341         rwlock_init(&sk->sk_callback_lock);
2342         lockdep_set_class_and_name(&sk->sk_callback_lock,
2343                         af_callback_keys + sk->sk_family,
2344                         af_family_clock_key_strings[sk->sk_family]);
2345 
2346         sk->sk_state_change     =       sock_def_wakeup;
2347         sk->sk_data_ready       =       sock_def_readable;
2348         sk->sk_write_space      =       sock_def_write_space;
2349         sk->sk_error_report     =       sock_def_error_report;
2350         sk->sk_destruct         =       sock_def_destruct;
2351 
2352         sk->sk_frag.page        =       NULL;
2353         sk->sk_frag.offset      =       0;
2354         sk->sk_peek_off         =       -1;
2355 
2356         sk->sk_peer_pid         =       NULL;
2357         sk->sk_peer_cred        =       NULL;
2358         sk->sk_write_pending    =       0;
2359         sk->sk_rcvlowat         =       1;
2360         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
2361         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
2362 
2363         sk->sk_stamp = ktime_set(-1L, 0);
2364 
2365 #ifdef CONFIG_NET_RX_BUSY_POLL
2366         sk->sk_napi_id          =       0;
2367         sk->sk_ll_usec          =       sysctl_net_busy_read;
2368 #endif
2369 
2370         sk->sk_max_pacing_rate = ~0U;
2371         sk->sk_pacing_rate = ~0U;
2372         /*
2373          * Before updating sk_refcnt, we must commit prior changes to memory
2374          * (Documentation/RCU/rculist_nulls.txt for details)
2375          */
2376         smp_wmb();
2377         atomic_set(&sk->sk_refcnt, 1);
2378         atomic_set(&sk->sk_drops, 0);
2379 }
2380 EXPORT_SYMBOL(sock_init_data);
2381 
2382 void lock_sock_nested(struct sock *sk, int subclass)
2383 {
2384         might_sleep();
2385         spin_lock_bh(&sk->sk_lock.slock);
2386         if (sk->sk_lock.owned)
2387                 __lock_sock(sk);
2388         sk->sk_lock.owned = 1;
2389         spin_unlock(&sk->sk_lock.slock);
2390         /*
2391          * The sk_lock has mutex_lock() semantics here:
2392          */
2393         mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2394         local_bh_enable();
2395 }
2396 EXPORT_SYMBOL(lock_sock_nested);
2397 
2398 void release_sock(struct sock *sk)
2399 {
2400         /*
2401          * The sk_lock has mutex_unlock() semantics:
2402          */
2403         mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2404 
2405         spin_lock_bh(&sk->sk_lock.slock);
2406         if (sk->sk_backlog.tail)
2407                 __release_sock(sk);
2408 
2409         /* Warning : release_cb() might need to release sk ownership,
2410          * ie call sock_release_ownership(sk) before us.
2411          */
2412         if (sk->sk_prot->release_cb)
2413                 sk->sk_prot->release_cb(sk);
2414 
2415         sock_release_ownership(sk);
2416         if (waitqueue_active(&sk->sk_lock.wq))
2417                 wake_up(&sk->sk_lock.wq);
2418         spin_unlock_bh(&sk->sk_lock.slock);
2419 }
2420 EXPORT_SYMBOL(release_sock);
2421 
2422 /**
2423  * lock_sock_fast - fast version of lock_sock
2424  * @sk: socket
2425  *
2426  * This version should be used for very small section, where process wont block
2427  * return false if fast path is taken
2428  *   sk_lock.slock locked, owned = 0, BH disabled
2429  * return true if slow path is taken
2430  *   sk_lock.slock unlocked, owned = 1, BH enabled
2431  */
2432 bool lock_sock_fast(struct sock *sk)
2433 {
2434         might_sleep();
2435         spin_lock_bh(&sk->sk_lock.slock);
2436 
2437         if (!sk->sk_lock.owned)
2438                 /*
2439                  * Note : We must disable BH
2440                  */
2441                 return false;
2442 
2443         __lock_sock(sk);
2444         sk->sk_lock.owned = 1;
2445         spin_unlock(&sk->sk_lock.slock);
2446         /*
2447          * The sk_lock has mutex_lock() semantics here:
2448          */
2449         mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2450         local_bh_enable();
2451         return true;
2452 }
2453 EXPORT_SYMBOL(lock_sock_fast);
2454 
2455 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2456 {
2457         struct timeval tv;
2458         if (!sock_flag(sk, SOCK_TIMESTAMP))
2459                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2460         tv = ktime_to_timeval(sk->sk_stamp);
2461         if (tv.tv_sec == -1)
2462                 return -ENOENT;
2463         if (tv.tv_sec == 0) {
2464                 sk->sk_stamp = ktime_get_real();
2465                 tv = ktime_to_timeval(sk->sk_stamp);
2466         }
2467         return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2468 }
2469 EXPORT_SYMBOL(sock_get_timestamp);
2470 
2471 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2472 {
2473         struct timespec ts;
2474         if (!sock_flag(sk, SOCK_TIMESTAMP))
2475                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2476         ts = ktime_to_timespec(sk->sk_stamp);
2477         if (ts.tv_sec == -1)
2478                 return -ENOENT;
2479         if (ts.tv_sec == 0) {
2480                 sk->sk_stamp = ktime_get_real();
2481                 ts = ktime_to_timespec(sk->sk_stamp);
2482         }
2483         return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2484 }
2485 EXPORT_SYMBOL(sock_get_timestampns);
2486 
2487 void sock_enable_timestamp(struct sock *sk, int flag)
2488 {
2489         if (!sock_flag(sk, flag)) {
2490                 unsigned long previous_flags = sk->sk_flags;
2491 
2492                 sock_set_flag(sk, flag);
2493                 /*
2494                  * we just set one of the two flags which require net
2495                  * time stamping, but time stamping might have been on
2496                  * already because of the other one
2497                  */
2498                 if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2499                         net_enable_timestamp();
2500         }
2501 }
2502 
2503 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2504                        int level, int type)
2505 {
2506         struct sock_exterr_skb *serr;
2507         struct sk_buff *skb;
2508         int copied, err;
2509 
2510         err = -EAGAIN;
2511         skb = sock_dequeue_err_skb(sk);
2512         if (skb == NULL)
2513                 goto out;
2514 
2515         copied = skb->len;
2516         if (copied > len) {
2517                 msg->msg_flags |= MSG_TRUNC;
2518                 copied = len;
2519         }
2520         err = skb_copy_datagram_msg(skb, 0, msg, copied);
2521         if (err)
2522                 goto out_free_skb;
2523 
2524         sock_recv_timestamp(msg, sk, skb);
2525 
2526         serr = SKB_EXT_ERR(skb);
2527         put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2528 
2529         msg->msg_flags |= MSG_ERRQUEUE;
2530         err = copied;
2531 
2532 out_free_skb:
2533         kfree_skb(skb);
2534 out:
2535         return err;
2536 }
2537 EXPORT_SYMBOL(sock_recv_errqueue);
2538 
2539 /*
2540  *      Get a socket option on an socket.
2541  *
2542  *      FIX: POSIX 1003.1g is very ambiguous here. It states that
2543  *      asynchronous errors should be reported by getsockopt. We assume
2544  *      this means if you specify SO_ERROR (otherwise whats the point of it).
2545  */
2546 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2547                            char __user *optval, int __user *optlen)
2548 {
2549         struct sock *sk = sock->sk;
2550 
2551         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2552 }
2553 EXPORT_SYMBOL(sock_common_getsockopt);
2554 
2555 #ifdef CONFIG_COMPAT
2556 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2557                                   char __user *optval, int __user *optlen)
2558 {
2559         struct sock *sk = sock->sk;
2560 
2561         if (sk->sk_prot->compat_getsockopt != NULL)
2562                 return sk->sk_prot->compat_getsockopt(sk, level, optname,
2563                                                       optval, optlen);
2564         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2565 }
2566 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2567 #endif
2568 
2569 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2570                         struct msghdr *msg, size_t size, int flags)
2571 {
2572         struct sock *sk = sock->sk;
2573         int addr_len = 0;
2574         int err;
2575 
2576         err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2577                                    flags & ~MSG_DONTWAIT, &addr_len);
2578         if (err >= 0)
2579                 msg->msg_namelen = addr_len;
2580         return err;
2581 }
2582 EXPORT_SYMBOL(sock_common_recvmsg);
2583 
2584 /*
2585  *      Set socket options on an inet socket.
2586  */
2587 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2588                            char __user *optval, unsigned int optlen)
2589 {
2590         struct sock *sk = sock->sk;
2591 
2592         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2593 }
2594 EXPORT_SYMBOL(sock_common_setsockopt);
2595 
2596 #ifdef CONFIG_COMPAT
2597 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2598                                   char __user *optval, unsigned int optlen)
2599 {
2600         struct sock *sk = sock->sk;
2601 
2602         if (sk->sk_prot->compat_setsockopt != NULL)
2603                 return sk->sk_prot->compat_setsockopt(sk, level, optname,
2604                                                       optval, optlen);
2605         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2606 }
2607 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2608 #endif
2609 
2610 void sk_common_release(struct sock *sk)
2611 {
2612         if (sk->sk_prot->destroy)
2613                 sk->sk_prot->destroy(sk);
2614 
2615         /*
2616          * Observation: when sock_common_release is called, processes have
2617          * no access to socket. But net still has.
2618          * Step one, detach it from networking:
2619          *
2620          * A. Remove from hash tables.
2621          */
2622 
2623         sk->sk_prot->unhash(sk);
2624 
2625         /*
2626          * In this point socket cannot receive new packets, but it is possible
2627          * that some packets are in flight because some CPU runs receiver and
2628          * did hash table lookup before we unhashed socket. They will achieve
2629          * receive queue and will be purged by socket destructor.
2630          *
2631          * Also we still have packets pending on receive queue and probably,
2632          * our own packets waiting in device queues. sock_destroy will drain
2633          * receive queue, but transmitted packets will delay socket destruction
2634          * until the last reference will be released.
2635          */
2636 
2637         sock_orphan(sk);
2638 
2639         xfrm_sk_free_policy(sk);
2640 
2641         sk_refcnt_debug_release(sk);
2642 
2643         if (sk->sk_frag.page) {
2644                 put_page(sk->sk_frag.page);
2645                 sk->sk_frag.page = NULL;
2646         }
2647 
2648         sock_put(sk);
2649 }
2650 EXPORT_SYMBOL(sk_common_release);
2651 
2652 #ifdef CONFIG_PROC_FS
2653 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
2654 struct prot_inuse {
2655         int val[PROTO_INUSE_NR];
2656 };
2657 
2658 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2659 
2660 #ifdef CONFIG_NET_NS
2661 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2662 {
2663         __this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2664 }
2665 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2666 
2667 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2668 {
2669         int cpu, idx = prot->inuse_idx;
2670         int res = 0;
2671 
2672         for_each_possible_cpu(cpu)
2673                 res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2674 
2675         return res >= 0 ? res : 0;
2676 }
2677 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2678 
2679 static int __net_init sock_inuse_init_net(struct net *net)
2680 {
2681         net->core.inuse = alloc_percpu(struct prot_inuse);
2682         return net->core.inuse ? 0 : -ENOMEM;
2683 }
2684 
2685 static void __net_exit sock_inuse_exit_net(struct net *net)
2686 {
2687         free_percpu(net->core.inuse);
2688 }
2689 
2690 static struct pernet_operations net_inuse_ops = {
2691         .init = sock_inuse_init_net,
2692         .exit = sock_inuse_exit_net,
2693 };
2694 
2695 static __init int net_inuse_init(void)
2696 {
2697         if (register_pernet_subsys(&net_inuse_ops))
2698                 panic("Cannot initialize net inuse counters");
2699 
2700         return 0;
2701 }
2702 
2703 core_initcall(net_inuse_init);
2704 #else
2705 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2706 
2707 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2708 {
2709         __this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2710 }
2711 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2712 
2713 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2714 {
2715         int cpu, idx = prot->inuse_idx;
2716         int res = 0;
2717 
2718         for_each_possible_cpu(cpu)
2719                 res += per_cpu(prot_inuse, cpu).val[idx];
2720 
2721         return res >= 0 ? res : 0;
2722 }
2723 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2724 #endif
2725 
2726 static void assign_proto_idx(struct proto *prot)
2727 {
2728         prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2729 
2730         if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2731                 pr_err("PROTO_INUSE_NR exhausted\n");
2732                 return;
2733         }
2734 
2735         set_bit(prot->inuse_idx, proto_inuse_idx);
2736 }
2737 
2738 static void release_proto_idx(struct proto *prot)
2739 {
2740         if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2741                 clear_bit(prot->inuse_idx, proto_inuse_idx);
2742 }
2743 #else
2744 static inline void assign_proto_idx(struct proto *prot)
2745 {
2746 }
2747 
2748 static inline void release_proto_idx(struct proto *prot)
2749 {
2750 }
2751 #endif
2752 
2753 int proto_register(struct proto *prot, int alloc_slab)
2754 {
2755         if (alloc_slab) {
2756                 prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2757                                         SLAB_HWCACHE_ALIGN | prot->slab_flags,
2758                                         NULL);
2759 
2760                 if (prot->slab == NULL) {
2761                         pr_crit("%s: Can't create sock SLAB cache!\n",
2762                                 prot->name);
2763                         goto out;
2764                 }
2765 
2766                 if (prot->rsk_prot != NULL) {
2767                         prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2768                         if (prot->rsk_prot->slab_name == NULL)
2769                                 goto out_free_sock_slab;
2770 
2771                         prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2772                                                                  prot->rsk_prot->obj_size, 0,
2773                                                                  SLAB_HWCACHE_ALIGN, NULL);
2774 
2775                         if (prot->rsk_prot->slab == NULL) {
2776                                 pr_crit("%s: Can't create request sock SLAB cache!\n",
2777                                         prot->name);
2778                                 goto out_free_request_sock_slab_name;
2779                         }
2780                 }
2781 
2782                 if (prot->twsk_prot != NULL) {
2783                         prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2784 
2785                         if (prot->twsk_prot->twsk_slab_name == NULL)
2786                                 goto out_free_request_sock_slab;
2787 
2788                         prot->twsk_prot->twsk_slab =
2789                                 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2790                                                   prot->twsk_prot->twsk_obj_size,
2791                                                   0,
2792                                                   SLAB_HWCACHE_ALIGN |
2793                                                         prot->slab_flags,
2794                                                   NULL);
2795                         if (prot->twsk_prot->twsk_slab == NULL)
2796                                 goto out_free_timewait_sock_slab_name;
2797                 }
2798         }
2799 
2800         mutex_lock(&proto_list_mutex);
2801         list_add(&prot->node, &proto_list);
2802         assign_proto_idx(prot);
2803         mutex_unlock(&proto_list_mutex);
2804         return 0;
2805 
2806 out_free_timewait_sock_slab_name:
2807         kfree(prot->twsk_prot->twsk_slab_name);
2808 out_free_request_sock_slab:
2809         if (prot->rsk_prot && prot->rsk_prot->slab) {
2810                 kmem_cache_destroy(prot->rsk_prot->slab);
2811                 prot->rsk_prot->slab = NULL;
2812         }
2813 out_free_request_sock_slab_name:
2814         if (prot->rsk_prot)
2815                 kfree(prot->rsk_prot->slab_name);
2816 out_free_sock_slab:
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         if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2837                 kmem_cache_destroy(prot->rsk_prot->slab);
2838                 kfree(prot->rsk_prot->slab_name);
2839                 prot->rsk_prot->slab = NULL;
2840         }
2841 
2842         if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2843                 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2844                 kfree(prot->twsk_prot->twsk_slab_name);
2845                 prot->twsk_prot->twsk_slab = NULL;
2846         }
2847 }
2848 EXPORT_SYMBOL(proto_unregister);
2849 
2850 #ifdef CONFIG_PROC_FS
2851 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2852         __acquires(proto_list_mutex)
2853 {
2854         mutex_lock(&proto_list_mutex);
2855         return seq_list_start_head(&proto_list, *pos);
2856 }
2857 
2858 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2859 {
2860         return seq_list_next(v, &proto_list, pos);
2861 }
2862 
2863 static void proto_seq_stop(struct seq_file *seq, void *v)
2864         __releases(proto_list_mutex)
2865 {
2866         mutex_unlock(&proto_list_mutex);
2867 }
2868 
2869 static char proto_method_implemented(const void *method)
2870 {
2871         return method == NULL ? 'n' : 'y';
2872 }
2873 static long sock_prot_memory_allocated(struct proto *proto)
2874 {
2875         return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2876 }
2877 
2878 static char *sock_prot_memory_pressure(struct proto *proto)
2879 {
2880         return proto->memory_pressure != NULL ?
2881         proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2882 }
2883 
2884 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2885 {
2886 
2887         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2888                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2889                    proto->name,
2890                    proto->obj_size,
2891                    sock_prot_inuse_get(seq_file_net(seq), proto),
2892                    sock_prot_memory_allocated(proto),
2893                    sock_prot_memory_pressure(proto),
2894                    proto->max_header,
2895                    proto->slab == NULL ? "no" : "yes",
2896                    module_name(proto->owner),
2897                    proto_method_implemented(proto->close),
2898                    proto_method_implemented(proto->connect),
2899                    proto_method_implemented(proto->disconnect),
2900                    proto_method_implemented(proto->accept),
2901                    proto_method_implemented(proto->ioctl),
2902                    proto_method_implemented(proto->init),
2903                    proto_method_implemented(proto->destroy),
2904                    proto_method_implemented(proto->shutdown),
2905                    proto_method_implemented(proto->setsockopt),
2906                    proto_method_implemented(proto->getsockopt),
2907                    proto_method_implemented(proto->sendmsg),
2908                    proto_method_implemented(proto->recvmsg),
2909                    proto_method_implemented(proto->sendpage),
2910                    proto_method_implemented(proto->bind),
2911                    proto_method_implemented(proto->backlog_rcv),
2912                    proto_method_implemented(proto->hash),
2913                    proto_method_implemented(proto->unhash),
2914                    proto_method_implemented(proto->get_port),
2915                    proto_method_implemented(proto->enter_memory_pressure));
2916 }
2917 
2918 static int proto_seq_show(struct seq_file *seq, void *v)
2919 {
2920         if (v == &proto_list)
2921                 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2922                            "protocol",
2923                            "size",
2924                            "sockets",
2925                            "memory",
2926                            "press",
2927                            "maxhdr",
2928                            "slab",
2929                            "module",
2930                            "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2931         else
2932                 proto_seq_printf(seq, list_entry(v, struct proto, node));
2933         return 0;
2934 }
2935 
2936 static const struct seq_operations proto_seq_ops = {
2937         .start  = proto_seq_start,
2938         .next   = proto_seq_next,
2939         .stop   = proto_seq_stop,
2940         .show   = proto_seq_show,
2941 };
2942 
2943 static int proto_seq_open(struct inode *inode, struct file *file)
2944 {
2945         return seq_open_net(inode, file, &proto_seq_ops,
2946                             sizeof(struct seq_net_private));
2947 }
2948 
2949 static const struct file_operations proto_seq_fops = {
2950         .owner          = THIS_MODULE,
2951         .open           = proto_seq_open,
2952         .read           = seq_read,
2953         .llseek         = seq_lseek,
2954         .release        = seq_release_net,
2955 };
2956 
2957 static __net_init int proto_init_net(struct net *net)
2958 {
2959         if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
2960                 return -ENOMEM;
2961 
2962         return 0;
2963 }
2964 
2965 static __net_exit void proto_exit_net(struct net *net)
2966 {
2967         remove_proc_entry("protocols", net->proc_net);
2968 }
2969 
2970 
2971 static __net_initdata struct pernet_operations proto_net_ops = {
2972         .init = proto_init_net,
2973         .exit = proto_exit_net,
2974 };
2975 
2976 static int __init proto_init(void)
2977 {
2978         return register_pernet_subsys(&proto_net_ops);
2979 }
2980 
2981 subsys_initcall(proto_init);
2982 
2983 #endif /* PROC_FS */
2984 

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