Version:  2.6.34 2.6.35 2.6.36 2.6.37 2.6.38 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14

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

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