Version:  2.0.40 2.2.26 2.4.37 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5

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 #include <linux/sock_diag.h>
135 
136 #include <linux/filter.h>
137 #include <net/sock_reuseport.h>
138 
139 #include <trace/events/sock.h>
140 
141 #ifdef CONFIG_INET
142 #include <net/tcp.h>
143 #endif
144 
145 #include <net/busy_poll.h>
146 
147 static DEFINE_MUTEX(proto_list_mutex);
148 static LIST_HEAD(proto_list);
149 
150 /**
151  * sk_ns_capable - General socket capability test
152  * @sk: Socket to use a capability on or through
153  * @user_ns: The user namespace of the capability to use
154  * @cap: The capability to use
155  *
156  * Test to see if the opener of the socket had when the socket was
157  * created and the current process has the capability @cap in the user
158  * namespace @user_ns.
159  */
160 bool sk_ns_capable(const struct sock *sk,
161                    struct user_namespace *user_ns, int cap)
162 {
163         return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
164                 ns_capable(user_ns, cap);
165 }
166 EXPORT_SYMBOL(sk_ns_capable);
167 
168 /**
169  * sk_capable - Socket global capability test
170  * @sk: Socket to use a capability on or through
171  * @cap: The global capability to use
172  *
173  * Test to see if the opener of the socket had when the socket was
174  * created and the current process has the capability @cap in all user
175  * namespaces.
176  */
177 bool sk_capable(const struct sock *sk, int cap)
178 {
179         return sk_ns_capable(sk, &init_user_ns, cap);
180 }
181 EXPORT_SYMBOL(sk_capable);
182 
183 /**
184  * sk_net_capable - Network namespace socket capability test
185  * @sk: Socket to use a capability on or through
186  * @cap: The capability to use
187  *
188  * Test to see if the opener of the socket had when the socket was created
189  * and the current process has the capability @cap over the network namespace
190  * the socket is a member of.
191  */
192 bool sk_net_capable(const struct sock *sk, int cap)
193 {
194         return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
195 }
196 EXPORT_SYMBOL(sk_net_capable);
197 
198 /*
199  * Each address family might have different locking rules, so we have
200  * one slock key per address family:
201  */
202 static struct lock_class_key af_family_keys[AF_MAX];
203 static struct lock_class_key af_family_slock_keys[AF_MAX];
204 
205 /*
206  * Make lock validator output more readable. (we pre-construct these
207  * strings build-time, so that runtime initialization of socket
208  * locks is fast):
209  */
210 static const char *const af_family_key_strings[AF_MAX+1] = {
211   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
212   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
213   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
214   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
215   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
216   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
217   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
218   "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
219   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
220   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
221   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
222   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
223   "sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG"      ,
224   "sk_lock-AF_NFC"   , "sk_lock-AF_VSOCK"    , "sk_lock-AF_MAX"
225 };
226 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
227   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
228   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
229   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
230   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
231   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
232   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
233   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
234   "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
235   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
236   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
237   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
238   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
239   "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG"      ,
240   "slock-AF_NFC"   , "slock-AF_VSOCK"    ,"slock-AF_MAX"
241 };
242 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
243   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
244   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
245   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
246   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
247   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
248   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
249   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
250   "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
251   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
252   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
253   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
254   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
255   "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG"      ,
256   "clock-AF_NFC"   , "clock-AF_VSOCK"    , "clock-AF_MAX"
257 };
258 
259 /*
260  * sk_callback_lock locking rules are per-address-family,
261  * so split the lock classes by using a per-AF key:
262  */
263 static struct lock_class_key af_callback_keys[AF_MAX];
264 
265 /* Take into consideration the size of the struct sk_buff overhead in the
266  * determination of these values, since that is non-constant across
267  * platforms.  This makes socket queueing behavior and performance
268  * not depend upon such differences.
269  */
270 #define _SK_MEM_PACKETS         256
271 #define _SK_MEM_OVERHEAD        SKB_TRUESIZE(256)
272 #define SK_WMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
273 #define SK_RMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
274 
275 /* Run time adjustable parameters. */
276 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
277 EXPORT_SYMBOL(sysctl_wmem_max);
278 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
279 EXPORT_SYMBOL(sysctl_rmem_max);
280 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
281 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
282 
283 /* Maximal space eaten by iovec or ancillary data plus some space */
284 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
285 EXPORT_SYMBOL(sysctl_optmem_max);
286 
287 int sysctl_tstamp_allow_data __read_mostly = 1;
288 
289 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
290 EXPORT_SYMBOL_GPL(memalloc_socks);
291 
292 /**
293  * sk_set_memalloc - sets %SOCK_MEMALLOC
294  * @sk: socket to set it on
295  *
296  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
297  * It's the responsibility of the admin to adjust min_free_kbytes
298  * to meet the requirements
299  */
300 void sk_set_memalloc(struct sock *sk)
301 {
302         sock_set_flag(sk, SOCK_MEMALLOC);
303         sk->sk_allocation |= __GFP_MEMALLOC;
304         static_key_slow_inc(&memalloc_socks);
305 }
306 EXPORT_SYMBOL_GPL(sk_set_memalloc);
307 
308 void sk_clear_memalloc(struct sock *sk)
309 {
310         sock_reset_flag(sk, SOCK_MEMALLOC);
311         sk->sk_allocation &= ~__GFP_MEMALLOC;
312         static_key_slow_dec(&memalloc_socks);
313 
314         /*
315          * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
316          * progress of swapping. SOCK_MEMALLOC may be cleared while
317          * it has rmem allocations due to the last swapfile being deactivated
318          * but there is a risk that the socket is unusable due to exceeding
319          * the rmem limits. Reclaim the reserves and obey rmem limits again.
320          */
321         sk_mem_reclaim(sk);
322 }
323 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
324 
325 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
326 {
327         int ret;
328         unsigned long pflags = current->flags;
329 
330         /* these should have been dropped before queueing */
331         BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
332 
333         current->flags |= PF_MEMALLOC;
334         ret = sk->sk_backlog_rcv(sk, skb);
335         tsk_restore_flags(current, pflags, PF_MEMALLOC);
336 
337         return ret;
338 }
339 EXPORT_SYMBOL(__sk_backlog_rcv);
340 
341 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
342 {
343         struct timeval tv;
344 
345         if (optlen < sizeof(tv))
346                 return -EINVAL;
347         if (copy_from_user(&tv, optval, sizeof(tv)))
348                 return -EFAULT;
349         if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
350                 return -EDOM;
351 
352         if (tv.tv_sec < 0) {
353                 static int warned __read_mostly;
354 
355                 *timeo_p = 0;
356                 if (warned < 10 && net_ratelimit()) {
357                         warned++;
358                         pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
359                                 __func__, current->comm, task_pid_nr(current));
360                 }
361                 return 0;
362         }
363         *timeo_p = MAX_SCHEDULE_TIMEOUT;
364         if (tv.tv_sec == 0 && tv.tv_usec == 0)
365                 return 0;
366         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
367                 *timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
368         return 0;
369 }
370 
371 static void sock_warn_obsolete_bsdism(const char *name)
372 {
373         static int warned;
374         static char warncomm[TASK_COMM_LEN];
375         if (strcmp(warncomm, current->comm) && warned < 5) {
376                 strcpy(warncomm,  current->comm);
377                 pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
378                         warncomm, name);
379                 warned++;
380         }
381 }
382 
383 static bool sock_needs_netstamp(const struct sock *sk)
384 {
385         switch (sk->sk_family) {
386         case AF_UNSPEC:
387         case AF_UNIX:
388                 return false;
389         default:
390                 return true;
391         }
392 }
393 
394 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
395 {
396         if (sk->sk_flags & flags) {
397                 sk->sk_flags &= ~flags;
398                 if (sock_needs_netstamp(sk) &&
399                     !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
400                         net_disable_timestamp();
401         }
402 }
403 
404 
405 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
406 {
407         int err;
408         unsigned long flags;
409         struct sk_buff_head *list = &sk->sk_receive_queue;
410 
411         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
412                 atomic_inc(&sk->sk_drops);
413                 trace_sock_rcvqueue_full(sk, skb);
414                 return -ENOMEM;
415         }
416 
417         err = sk_filter(sk, skb);
418         if (err)
419                 return err;
420 
421         if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
422                 atomic_inc(&sk->sk_drops);
423                 return -ENOBUFS;
424         }
425 
426         skb->dev = NULL;
427         skb_set_owner_r(skb, sk);
428 
429         /* we escape from rcu protected region, make sure we dont leak
430          * a norefcounted dst
431          */
432         skb_dst_force(skb);
433 
434         spin_lock_irqsave(&list->lock, flags);
435         sock_skb_set_dropcount(sk, skb);
436         __skb_queue_tail(list, skb);
437         spin_unlock_irqrestore(&list->lock, flags);
438 
439         if (!sock_flag(sk, SOCK_DEAD))
440                 sk->sk_data_ready(sk);
441         return 0;
442 }
443 EXPORT_SYMBOL(sock_queue_rcv_skb);
444 
445 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
446 {
447         int rc = NET_RX_SUCCESS;
448 
449         if (sk_filter(sk, skb))
450                 goto discard_and_relse;
451 
452         skb->dev = NULL;
453 
454         if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
455                 atomic_inc(&sk->sk_drops);
456                 goto discard_and_relse;
457         }
458         if (nested)
459                 bh_lock_sock_nested(sk);
460         else
461                 bh_lock_sock(sk);
462         if (!sock_owned_by_user(sk)) {
463                 /*
464                  * trylock + unlock semantics:
465                  */
466                 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
467 
468                 rc = sk_backlog_rcv(sk, skb);
469 
470                 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
471         } else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
472                 bh_unlock_sock(sk);
473                 atomic_inc(&sk->sk_drops);
474                 goto discard_and_relse;
475         }
476 
477         bh_unlock_sock(sk);
478 out:
479         sock_put(sk);
480         return rc;
481 discard_and_relse:
482         kfree_skb(skb);
483         goto out;
484 }
485 EXPORT_SYMBOL(sk_receive_skb);
486 
487 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
488 {
489         struct dst_entry *dst = __sk_dst_get(sk);
490 
491         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
492                 sk_tx_queue_clear(sk);
493                 RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
494                 dst_release(dst);
495                 return NULL;
496         }
497 
498         return dst;
499 }
500 EXPORT_SYMBOL(__sk_dst_check);
501 
502 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
503 {
504         struct dst_entry *dst = sk_dst_get(sk);
505 
506         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
507                 sk_dst_reset(sk);
508                 dst_release(dst);
509                 return NULL;
510         }
511 
512         return dst;
513 }
514 EXPORT_SYMBOL(sk_dst_check);
515 
516 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
517                                 int optlen)
518 {
519         int ret = -ENOPROTOOPT;
520 #ifdef CONFIG_NETDEVICES
521         struct net *net = sock_net(sk);
522         char devname[IFNAMSIZ];
523         int index;
524 
525         /* Sorry... */
526         ret = -EPERM;
527         if (!ns_capable(net->user_ns, CAP_NET_RAW))
528                 goto out;
529 
530         ret = -EINVAL;
531         if (optlen < 0)
532                 goto out;
533 
534         /* Bind this socket to a particular device like "eth0",
535          * as specified in the passed interface name. If the
536          * name is "" or the option length is zero the socket
537          * is not bound.
538          */
539         if (optlen > IFNAMSIZ - 1)
540                 optlen = IFNAMSIZ - 1;
541         memset(devname, 0, sizeof(devname));
542 
543         ret = -EFAULT;
544         if (copy_from_user(devname, optval, optlen))
545                 goto out;
546 
547         index = 0;
548         if (devname[0] != '\0') {
549                 struct net_device *dev;
550 
551                 rcu_read_lock();
552                 dev = dev_get_by_name_rcu(net, devname);
553                 if (dev)
554                         index = dev->ifindex;
555                 rcu_read_unlock();
556                 ret = -ENODEV;
557                 if (!dev)
558                         goto out;
559         }
560 
561         lock_sock(sk);
562         sk->sk_bound_dev_if = index;
563         sk_dst_reset(sk);
564         release_sock(sk);
565 
566         ret = 0;
567 
568 out:
569 #endif
570 
571         return ret;
572 }
573 
574 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
575                                 int __user *optlen, int len)
576 {
577         int ret = -ENOPROTOOPT;
578 #ifdef CONFIG_NETDEVICES
579         struct net *net = sock_net(sk);
580         char devname[IFNAMSIZ];
581 
582         if (sk->sk_bound_dev_if == 0) {
583                 len = 0;
584                 goto zero;
585         }
586 
587         ret = -EINVAL;
588         if (len < IFNAMSIZ)
589                 goto out;
590 
591         ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
592         if (ret)
593                 goto out;
594 
595         len = strlen(devname) + 1;
596 
597         ret = -EFAULT;
598         if (copy_to_user(optval, devname, len))
599                 goto out;
600 
601 zero:
602         ret = -EFAULT;
603         if (put_user(len, optlen))
604                 goto out;
605 
606         ret = 0;
607 
608 out:
609 #endif
610 
611         return ret;
612 }
613 
614 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
615 {
616         if (valbool)
617                 sock_set_flag(sk, bit);
618         else
619                 sock_reset_flag(sk, bit);
620 }
621 
622 bool sk_mc_loop(struct sock *sk)
623 {
624         if (dev_recursion_level())
625                 return false;
626         if (!sk)
627                 return true;
628         switch (sk->sk_family) {
629         case AF_INET:
630                 return inet_sk(sk)->mc_loop;
631 #if IS_ENABLED(CONFIG_IPV6)
632         case AF_INET6:
633                 return inet6_sk(sk)->mc_loop;
634 #endif
635         }
636         WARN_ON(1);
637         return true;
638 }
639 EXPORT_SYMBOL(sk_mc_loop);
640 
641 /*
642  *      This is meant for all protocols to use and covers goings on
643  *      at the socket level. Everything here is generic.
644  */
645 
646 int sock_setsockopt(struct socket *sock, int level, int optname,
647                     char __user *optval, unsigned int optlen)
648 {
649         struct sock *sk = sock->sk;
650         int val;
651         int valbool;
652         struct linger ling;
653         int ret = 0;
654 
655         /*
656          *      Options without arguments
657          */
658 
659         if (optname == SO_BINDTODEVICE)
660                 return sock_setbindtodevice(sk, optval, optlen);
661 
662         if (optlen < sizeof(int))
663                 return -EINVAL;
664 
665         if (get_user(val, (int __user *)optval))
666                 return -EFAULT;
667 
668         valbool = val ? 1 : 0;
669 
670         lock_sock(sk);
671 
672         switch (optname) {
673         case SO_DEBUG:
674                 if (val && !capable(CAP_NET_ADMIN))
675                         ret = -EACCES;
676                 else
677                         sock_valbool_flag(sk, SOCK_DBG, valbool);
678                 break;
679         case SO_REUSEADDR:
680                 sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
681                 break;
682         case SO_REUSEPORT:
683                 sk->sk_reuseport = valbool;
684                 break;
685         case SO_TYPE:
686         case SO_PROTOCOL:
687         case SO_DOMAIN:
688         case SO_ERROR:
689                 ret = -ENOPROTOOPT;
690                 break;
691         case SO_DONTROUTE:
692                 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
693                 break;
694         case SO_BROADCAST:
695                 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
696                 break;
697         case SO_SNDBUF:
698                 /* Don't error on this BSD doesn't and if you think
699                  * about it this is right. Otherwise apps have to
700                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
701                  * are treated in BSD as hints
702                  */
703                 val = min_t(u32, val, sysctl_wmem_max);
704 set_sndbuf:
705                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
706                 sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
707                 /* Wake up sending tasks if we upped the value. */
708                 sk->sk_write_space(sk);
709                 break;
710 
711         case SO_SNDBUFFORCE:
712                 if (!capable(CAP_NET_ADMIN)) {
713                         ret = -EPERM;
714                         break;
715                 }
716                 goto set_sndbuf;
717 
718         case SO_RCVBUF:
719                 /* Don't error on this BSD doesn't and if you think
720                  * about it this is right. Otherwise apps have to
721                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
722                  * are treated in BSD as hints
723                  */
724                 val = min_t(u32, val, sysctl_rmem_max);
725 set_rcvbuf:
726                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
727                 /*
728                  * We double it on the way in to account for
729                  * "struct sk_buff" etc. overhead.   Applications
730                  * assume that the SO_RCVBUF setting they make will
731                  * allow that much actual data to be received on that
732                  * socket.
733                  *
734                  * Applications are unaware that "struct sk_buff" and
735                  * other overheads allocate from the receive buffer
736                  * during socket buffer allocation.
737                  *
738                  * And after considering the possible alternatives,
739                  * returning the value we actually used in getsockopt
740                  * is the most desirable behavior.
741                  */
742                 sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
743                 break;
744 
745         case SO_RCVBUFFORCE:
746                 if (!capable(CAP_NET_ADMIN)) {
747                         ret = -EPERM;
748                         break;
749                 }
750                 goto set_rcvbuf;
751 
752         case SO_KEEPALIVE:
753 #ifdef CONFIG_INET
754                 if (sk->sk_protocol == IPPROTO_TCP &&
755                     sk->sk_type == SOCK_STREAM)
756                         tcp_set_keepalive(sk, valbool);
757 #endif
758                 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
759                 break;
760 
761         case SO_OOBINLINE:
762                 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
763                 break;
764 
765         case SO_NO_CHECK:
766                 sk->sk_no_check_tx = valbool;
767                 break;
768 
769         case SO_PRIORITY:
770                 if ((val >= 0 && val <= 6) ||
771                     ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
772                         sk->sk_priority = val;
773                 else
774                         ret = -EPERM;
775                 break;
776 
777         case SO_LINGER:
778                 if (optlen < sizeof(ling)) {
779                         ret = -EINVAL;  /* 1003.1g */
780                         break;
781                 }
782                 if (copy_from_user(&ling, optval, sizeof(ling))) {
783                         ret = -EFAULT;
784                         break;
785                 }
786                 if (!ling.l_onoff)
787                         sock_reset_flag(sk, SOCK_LINGER);
788                 else {
789 #if (BITS_PER_LONG == 32)
790                         if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
791                                 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
792                         else
793 #endif
794                                 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
795                         sock_set_flag(sk, SOCK_LINGER);
796                 }
797                 break;
798 
799         case SO_BSDCOMPAT:
800                 sock_warn_obsolete_bsdism("setsockopt");
801                 break;
802 
803         case SO_PASSCRED:
804                 if (valbool)
805                         set_bit(SOCK_PASSCRED, &sock->flags);
806                 else
807                         clear_bit(SOCK_PASSCRED, &sock->flags);
808                 break;
809 
810         case SO_TIMESTAMP:
811         case SO_TIMESTAMPNS:
812                 if (valbool)  {
813                         if (optname == SO_TIMESTAMP)
814                                 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
815                         else
816                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
817                         sock_set_flag(sk, SOCK_RCVTSTAMP);
818                         sock_enable_timestamp(sk, SOCK_TIMESTAMP);
819                 } else {
820                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
821                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
822                 }
823                 break;
824 
825         case SO_TIMESTAMPING:
826                 if (val & ~SOF_TIMESTAMPING_MASK) {
827                         ret = -EINVAL;
828                         break;
829                 }
830 
831                 if (val & SOF_TIMESTAMPING_OPT_ID &&
832                     !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
833                         if (sk->sk_protocol == IPPROTO_TCP &&
834                             sk->sk_type == SOCK_STREAM) {
835                                 if (sk->sk_state != TCP_ESTABLISHED) {
836                                         ret = -EINVAL;
837                                         break;
838                                 }
839                                 sk->sk_tskey = tcp_sk(sk)->snd_una;
840                         } else {
841                                 sk->sk_tskey = 0;
842                         }
843                 }
844                 sk->sk_tsflags = val;
845                 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
846                         sock_enable_timestamp(sk,
847                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
848                 else
849                         sock_disable_timestamp(sk,
850                                                (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
851                 break;
852 
853         case SO_RCVLOWAT:
854                 if (val < 0)
855                         val = INT_MAX;
856                 sk->sk_rcvlowat = val ? : 1;
857                 break;
858 
859         case SO_RCVTIMEO:
860                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
861                 break;
862 
863         case SO_SNDTIMEO:
864                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
865                 break;
866 
867         case SO_ATTACH_FILTER:
868                 ret = -EINVAL;
869                 if (optlen == sizeof(struct sock_fprog)) {
870                         struct sock_fprog fprog;
871 
872                         ret = -EFAULT;
873                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
874                                 break;
875 
876                         ret = sk_attach_filter(&fprog, sk);
877                 }
878                 break;
879 
880         case SO_ATTACH_BPF:
881                 ret = -EINVAL;
882                 if (optlen == sizeof(u32)) {
883                         u32 ufd;
884 
885                         ret = -EFAULT;
886                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
887                                 break;
888 
889                         ret = sk_attach_bpf(ufd, sk);
890                 }
891                 break;
892 
893         case SO_ATTACH_REUSEPORT_CBPF:
894                 ret = -EINVAL;
895                 if (optlen == sizeof(struct sock_fprog)) {
896                         struct sock_fprog fprog;
897 
898                         ret = -EFAULT;
899                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
900                                 break;
901 
902                         ret = sk_reuseport_attach_filter(&fprog, sk);
903                 }
904                 break;
905 
906         case SO_ATTACH_REUSEPORT_EBPF:
907                 ret = -EINVAL;
908                 if (optlen == sizeof(u32)) {
909                         u32 ufd;
910 
911                         ret = -EFAULT;
912                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
913                                 break;
914 
915                         ret = sk_reuseport_attach_bpf(ufd, sk);
916                 }
917                 break;
918 
919         case SO_DETACH_FILTER:
920                 ret = sk_detach_filter(sk);
921                 break;
922 
923         case SO_LOCK_FILTER:
924                 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
925                         ret = -EPERM;
926                 else
927                         sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
928                 break;
929 
930         case SO_PASSSEC:
931                 if (valbool)
932                         set_bit(SOCK_PASSSEC, &sock->flags);
933                 else
934                         clear_bit(SOCK_PASSSEC, &sock->flags);
935                 break;
936         case SO_MARK:
937                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
938                         ret = -EPERM;
939                 else
940                         sk->sk_mark = val;
941                 break;
942 
943         case SO_RXQ_OVFL:
944                 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
945                 break;
946 
947         case SO_WIFI_STATUS:
948                 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
949                 break;
950 
951         case SO_PEEK_OFF:
952                 if (sock->ops->set_peek_off)
953                         ret = sock->ops->set_peek_off(sk, val);
954                 else
955                         ret = -EOPNOTSUPP;
956                 break;
957 
958         case SO_NOFCS:
959                 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
960                 break;
961 
962         case SO_SELECT_ERR_QUEUE:
963                 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
964                 break;
965 
966 #ifdef CONFIG_NET_RX_BUSY_POLL
967         case SO_BUSY_POLL:
968                 /* allow unprivileged users to decrease the value */
969                 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
970                         ret = -EPERM;
971                 else {
972                         if (val < 0)
973                                 ret = -EINVAL;
974                         else
975                                 sk->sk_ll_usec = val;
976                 }
977                 break;
978 #endif
979 
980         case SO_MAX_PACING_RATE:
981                 sk->sk_max_pacing_rate = val;
982                 sk->sk_pacing_rate = min(sk->sk_pacing_rate,
983                                          sk->sk_max_pacing_rate);
984                 break;
985 
986         case SO_INCOMING_CPU:
987                 sk->sk_incoming_cpu = val;
988                 break;
989 
990         default:
991                 ret = -ENOPROTOOPT;
992                 break;
993         }
994         release_sock(sk);
995         return ret;
996 }
997 EXPORT_SYMBOL(sock_setsockopt);
998 
999 
1000 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1001                           struct ucred *ucred)
1002 {
1003         ucred->pid = pid_vnr(pid);
1004         ucred->uid = ucred->gid = -1;
1005         if (cred) {
1006                 struct user_namespace *current_ns = current_user_ns();
1007 
1008                 ucred->uid = from_kuid_munged(current_ns, cred->euid);
1009                 ucred->gid = from_kgid_munged(current_ns, cred->egid);
1010         }
1011 }
1012 
1013 int sock_getsockopt(struct socket *sock, int level, int optname,
1014                     char __user *optval, int __user *optlen)
1015 {
1016         struct sock *sk = sock->sk;
1017 
1018         union {
1019                 int val;
1020                 struct linger ling;
1021                 struct timeval tm;
1022         } v;
1023 
1024         int lv = sizeof(int);
1025         int len;
1026 
1027         if (get_user(len, optlen))
1028                 return -EFAULT;
1029         if (len < 0)
1030                 return -EINVAL;
1031 
1032         memset(&v, 0, sizeof(v));
1033 
1034         switch (optname) {
1035         case SO_DEBUG:
1036                 v.val = sock_flag(sk, SOCK_DBG);
1037                 break;
1038 
1039         case SO_DONTROUTE:
1040                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
1041                 break;
1042 
1043         case SO_BROADCAST:
1044                 v.val = sock_flag(sk, SOCK_BROADCAST);
1045                 break;
1046 
1047         case SO_SNDBUF:
1048                 v.val = sk->sk_sndbuf;
1049                 break;
1050 
1051         case SO_RCVBUF:
1052                 v.val = sk->sk_rcvbuf;
1053                 break;
1054 
1055         case SO_REUSEADDR:
1056                 v.val = sk->sk_reuse;
1057                 break;
1058 
1059         case SO_REUSEPORT:
1060                 v.val = sk->sk_reuseport;
1061                 break;
1062 
1063         case SO_KEEPALIVE:
1064                 v.val = sock_flag(sk, SOCK_KEEPOPEN);
1065                 break;
1066 
1067         case SO_TYPE:
1068                 v.val = sk->sk_type;
1069                 break;
1070 
1071         case SO_PROTOCOL:
1072                 v.val = sk->sk_protocol;
1073                 break;
1074 
1075         case SO_DOMAIN:
1076                 v.val = sk->sk_family;
1077                 break;
1078 
1079         case SO_ERROR:
1080                 v.val = -sock_error(sk);
1081                 if (v.val == 0)
1082                         v.val = xchg(&sk->sk_err_soft, 0);
1083                 break;
1084 
1085         case SO_OOBINLINE:
1086                 v.val = sock_flag(sk, SOCK_URGINLINE);
1087                 break;
1088 
1089         case SO_NO_CHECK:
1090                 v.val = sk->sk_no_check_tx;
1091                 break;
1092 
1093         case SO_PRIORITY:
1094                 v.val = sk->sk_priority;
1095                 break;
1096 
1097         case SO_LINGER:
1098                 lv              = sizeof(v.ling);
1099                 v.ling.l_onoff  = sock_flag(sk, SOCK_LINGER);
1100                 v.ling.l_linger = sk->sk_lingertime / HZ;
1101                 break;
1102 
1103         case SO_BSDCOMPAT:
1104                 sock_warn_obsolete_bsdism("getsockopt");
1105                 break;
1106 
1107         case SO_TIMESTAMP:
1108                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1109                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1110                 break;
1111 
1112         case SO_TIMESTAMPNS:
1113                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1114                 break;
1115 
1116         case SO_TIMESTAMPING:
1117                 v.val = sk->sk_tsflags;
1118                 break;
1119 
1120         case SO_RCVTIMEO:
1121                 lv = sizeof(struct timeval);
1122                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1123                         v.tm.tv_sec = 0;
1124                         v.tm.tv_usec = 0;
1125                 } else {
1126                         v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1127                         v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1128                 }
1129                 break;
1130 
1131         case SO_SNDTIMEO:
1132                 lv = sizeof(struct timeval);
1133                 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1134                         v.tm.tv_sec = 0;
1135                         v.tm.tv_usec = 0;
1136                 } else {
1137                         v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1138                         v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1139                 }
1140                 break;
1141 
1142         case SO_RCVLOWAT:
1143                 v.val = sk->sk_rcvlowat;
1144                 break;
1145 
1146         case SO_SNDLOWAT:
1147                 v.val = 1;
1148                 break;
1149 
1150         case SO_PASSCRED:
1151                 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1152                 break;
1153 
1154         case SO_PEERCRED:
1155         {
1156                 struct ucred peercred;
1157                 if (len > sizeof(peercred))
1158                         len = sizeof(peercred);
1159                 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1160                 if (copy_to_user(optval, &peercred, len))
1161                         return -EFAULT;
1162                 goto lenout;
1163         }
1164 
1165         case SO_PEERNAME:
1166         {
1167                 char address[128];
1168 
1169                 if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1170                         return -ENOTCONN;
1171                 if (lv < len)
1172                         return -EINVAL;
1173                 if (copy_to_user(optval, address, len))
1174                         return -EFAULT;
1175                 goto lenout;
1176         }
1177 
1178         /* Dubious BSD thing... Probably nobody even uses it, but
1179          * the UNIX standard wants it for whatever reason... -DaveM
1180          */
1181         case SO_ACCEPTCONN:
1182                 v.val = sk->sk_state == TCP_LISTEN;
1183                 break;
1184 
1185         case SO_PASSSEC:
1186                 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1187                 break;
1188 
1189         case SO_PEERSEC:
1190                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1191 
1192         case SO_MARK:
1193                 v.val = sk->sk_mark;
1194                 break;
1195 
1196         case SO_RXQ_OVFL:
1197                 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1198                 break;
1199 
1200         case SO_WIFI_STATUS:
1201                 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1202                 break;
1203 
1204         case SO_PEEK_OFF:
1205                 if (!sock->ops->set_peek_off)
1206                         return -EOPNOTSUPP;
1207 
1208                 v.val = sk->sk_peek_off;
1209                 break;
1210         case SO_NOFCS:
1211                 v.val = sock_flag(sk, SOCK_NOFCS);
1212                 break;
1213 
1214         case SO_BINDTODEVICE:
1215                 return sock_getbindtodevice(sk, optval, optlen, len);
1216 
1217         case SO_GET_FILTER:
1218                 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1219                 if (len < 0)
1220                         return len;
1221 
1222                 goto lenout;
1223 
1224         case SO_LOCK_FILTER:
1225                 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1226                 break;
1227 
1228         case SO_BPF_EXTENSIONS:
1229                 v.val = bpf_tell_extensions();
1230                 break;
1231 
1232         case SO_SELECT_ERR_QUEUE:
1233                 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1234                 break;
1235 
1236 #ifdef CONFIG_NET_RX_BUSY_POLL
1237         case SO_BUSY_POLL:
1238                 v.val = sk->sk_ll_usec;
1239                 break;
1240 #endif
1241 
1242         case SO_MAX_PACING_RATE:
1243                 v.val = sk->sk_max_pacing_rate;
1244                 break;
1245 
1246         case SO_INCOMING_CPU:
1247                 v.val = sk->sk_incoming_cpu;
1248                 break;
1249 
1250         default:
1251                 /* We implement the SO_SNDLOWAT etc to not be settable
1252                  * (1003.1g 7).
1253                  */
1254                 return -ENOPROTOOPT;
1255         }
1256 
1257         if (len > lv)
1258                 len = lv;
1259         if (copy_to_user(optval, &v, len))
1260                 return -EFAULT;
1261 lenout:
1262         if (put_user(len, optlen))
1263                 return -EFAULT;
1264         return 0;
1265 }
1266 
1267 /*
1268  * Initialize an sk_lock.
1269  *
1270  * (We also register the sk_lock with the lock validator.)
1271  */
1272 static inline void sock_lock_init(struct sock *sk)
1273 {
1274         sock_lock_init_class_and_name(sk,
1275                         af_family_slock_key_strings[sk->sk_family],
1276                         af_family_slock_keys + sk->sk_family,
1277                         af_family_key_strings[sk->sk_family],
1278                         af_family_keys + sk->sk_family);
1279 }
1280 
1281 /*
1282  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1283  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1284  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1285  */
1286 static void sock_copy(struct sock *nsk, const struct sock *osk)
1287 {
1288 #ifdef CONFIG_SECURITY_NETWORK
1289         void *sptr = nsk->sk_security;
1290 #endif
1291         memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1292 
1293         memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1294                osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1295 
1296 #ifdef CONFIG_SECURITY_NETWORK
1297         nsk->sk_security = sptr;
1298         security_sk_clone(osk, nsk);
1299 #endif
1300 }
1301 
1302 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1303 {
1304         unsigned long nulls1, nulls2;
1305 
1306         nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1307         nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1308         if (nulls1 > nulls2)
1309                 swap(nulls1, nulls2);
1310 
1311         if (nulls1 != 0)
1312                 memset((char *)sk, 0, nulls1);
1313         memset((char *)sk + nulls1 + sizeof(void *), 0,
1314                nulls2 - nulls1 - sizeof(void *));
1315         memset((char *)sk + nulls2 + sizeof(void *), 0,
1316                size - nulls2 - sizeof(void *));
1317 }
1318 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1319 
1320 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1321                 int family)
1322 {
1323         struct sock *sk;
1324         struct kmem_cache *slab;
1325 
1326         slab = prot->slab;
1327         if (slab != NULL) {
1328                 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1329                 if (!sk)
1330                         return sk;
1331                 if (priority & __GFP_ZERO) {
1332                         if (prot->clear_sk)
1333                                 prot->clear_sk(sk, prot->obj_size);
1334                         else
1335                                 sk_prot_clear_nulls(sk, prot->obj_size);
1336                 }
1337         } else
1338                 sk = kmalloc(prot->obj_size, priority);
1339 
1340         if (sk != NULL) {
1341                 kmemcheck_annotate_bitfield(sk, flags);
1342 
1343                 if (security_sk_alloc(sk, family, priority))
1344                         goto out_free;
1345 
1346                 if (!try_module_get(prot->owner))
1347                         goto out_free_sec;
1348                 sk_tx_queue_clear(sk);
1349                 cgroup_sk_alloc(&sk->sk_cgrp_data);
1350         }
1351 
1352         return sk;
1353 
1354 out_free_sec:
1355         security_sk_free(sk);
1356 out_free:
1357         if (slab != NULL)
1358                 kmem_cache_free(slab, sk);
1359         else
1360                 kfree(sk);
1361         return NULL;
1362 }
1363 
1364 static void sk_prot_free(struct proto *prot, struct sock *sk)
1365 {
1366         struct kmem_cache *slab;
1367         struct module *owner;
1368 
1369         owner = prot->owner;
1370         slab = prot->slab;
1371 
1372         cgroup_sk_free(&sk->sk_cgrp_data);
1373         security_sk_free(sk);
1374         if (slab != NULL)
1375                 kmem_cache_free(slab, sk);
1376         else
1377                 kfree(sk);
1378         module_put(owner);
1379 }
1380 
1381 /**
1382  *      sk_alloc - All socket objects are allocated here
1383  *      @net: the applicable net namespace
1384  *      @family: protocol family
1385  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1386  *      @prot: struct proto associated with this new sock instance
1387  *      @kern: is this to be a kernel socket?
1388  */
1389 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1390                       struct proto *prot, int kern)
1391 {
1392         struct sock *sk;
1393 
1394         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1395         if (sk) {
1396                 sk->sk_family = family;
1397                 /*
1398                  * See comment in struct sock definition to understand
1399                  * why we need sk_prot_creator -acme
1400                  */
1401                 sk->sk_prot = sk->sk_prot_creator = prot;
1402                 sock_lock_init(sk);
1403                 sk->sk_net_refcnt = kern ? 0 : 1;
1404                 if (likely(sk->sk_net_refcnt))
1405                         get_net(net);
1406                 sock_net_set(sk, net);
1407                 atomic_set(&sk->sk_wmem_alloc, 1);
1408 
1409                 sock_update_classid(&sk->sk_cgrp_data);
1410                 sock_update_netprioidx(&sk->sk_cgrp_data);
1411         }
1412 
1413         return sk;
1414 }
1415 EXPORT_SYMBOL(sk_alloc);
1416 
1417 void sk_destruct(struct sock *sk)
1418 {
1419         struct sk_filter *filter;
1420 
1421         if (sk->sk_destruct)
1422                 sk->sk_destruct(sk);
1423 
1424         filter = rcu_dereference_check(sk->sk_filter,
1425                                        atomic_read(&sk->sk_wmem_alloc) == 0);
1426         if (filter) {
1427                 sk_filter_uncharge(sk, filter);
1428                 RCU_INIT_POINTER(sk->sk_filter, NULL);
1429         }
1430         if (rcu_access_pointer(sk->sk_reuseport_cb))
1431                 reuseport_detach_sock(sk);
1432 
1433         sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1434 
1435         if (atomic_read(&sk->sk_omem_alloc))
1436                 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1437                          __func__, atomic_read(&sk->sk_omem_alloc));
1438 
1439         if (sk->sk_peer_cred)
1440                 put_cred(sk->sk_peer_cred);
1441         put_pid(sk->sk_peer_pid);
1442         if (likely(sk->sk_net_refcnt))
1443                 put_net(sock_net(sk));
1444         sk_prot_free(sk->sk_prot_creator, sk);
1445 }
1446 
1447 static void __sk_free(struct sock *sk)
1448 {
1449         if (unlikely(sock_diag_has_destroy_listeners(sk) && sk->sk_net_refcnt))
1450                 sock_diag_broadcast_destroy(sk);
1451         else
1452                 sk_destruct(sk);
1453 }
1454 
1455 void sk_free(struct sock *sk)
1456 {
1457         /*
1458          * We subtract one from sk_wmem_alloc and can know if
1459          * some packets are still in some tx queue.
1460          * If not null, sock_wfree() will call __sk_free(sk) later
1461          */
1462         if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1463                 __sk_free(sk);
1464 }
1465 EXPORT_SYMBOL(sk_free);
1466 
1467 /**
1468  *      sk_clone_lock - clone a socket, and lock its clone
1469  *      @sk: the socket to clone
1470  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1471  *
1472  *      Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1473  */
1474 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1475 {
1476         struct sock *newsk;
1477         bool is_charged = true;
1478 
1479         newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1480         if (newsk != NULL) {
1481                 struct sk_filter *filter;
1482 
1483                 sock_copy(newsk, sk);
1484 
1485                 /* SANITY */
1486                 if (likely(newsk->sk_net_refcnt))
1487                         get_net(sock_net(newsk));
1488                 sk_node_init(&newsk->sk_node);
1489                 sock_lock_init(newsk);
1490                 bh_lock_sock(newsk);
1491                 newsk->sk_backlog.head  = newsk->sk_backlog.tail = NULL;
1492                 newsk->sk_backlog.len = 0;
1493 
1494                 atomic_set(&newsk->sk_rmem_alloc, 0);
1495                 /*
1496                  * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1497                  */
1498                 atomic_set(&newsk->sk_wmem_alloc, 1);
1499                 atomic_set(&newsk->sk_omem_alloc, 0);
1500                 skb_queue_head_init(&newsk->sk_receive_queue);
1501                 skb_queue_head_init(&newsk->sk_write_queue);
1502 
1503                 rwlock_init(&newsk->sk_callback_lock);
1504                 lockdep_set_class_and_name(&newsk->sk_callback_lock,
1505                                 af_callback_keys + newsk->sk_family,
1506                                 af_family_clock_key_strings[newsk->sk_family]);
1507 
1508                 newsk->sk_dst_cache     = NULL;
1509                 newsk->sk_wmem_queued   = 0;
1510                 newsk->sk_forward_alloc = 0;
1511                 newsk->sk_send_head     = NULL;
1512                 newsk->sk_userlocks     = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1513 
1514                 sock_reset_flag(newsk, SOCK_DONE);
1515                 skb_queue_head_init(&newsk->sk_error_queue);
1516 
1517                 filter = rcu_dereference_protected(newsk->sk_filter, 1);
1518                 if (filter != NULL)
1519                         /* though it's an empty new sock, the charging may fail
1520                          * if sysctl_optmem_max was changed between creation of
1521                          * original socket and cloning
1522                          */
1523                         is_charged = sk_filter_charge(newsk, filter);
1524 
1525                 if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1526                         /* It is still raw copy of parent, so invalidate
1527                          * destructor and make plain sk_free() */
1528                         newsk->sk_destruct = NULL;
1529                         bh_unlock_sock(newsk);
1530                         sk_free(newsk);
1531                         newsk = NULL;
1532                         goto out;
1533                 }
1534 
1535                 newsk->sk_err      = 0;
1536                 newsk->sk_priority = 0;
1537                 newsk->sk_incoming_cpu = raw_smp_processor_id();
1538                 atomic64_set(&newsk->sk_cookie, 0);
1539                 /*
1540                  * Before updating sk_refcnt, we must commit prior changes to memory
1541                  * (Documentation/RCU/rculist_nulls.txt for details)
1542                  */
1543                 smp_wmb();
1544                 atomic_set(&newsk->sk_refcnt, 2);
1545 
1546                 /*
1547                  * Increment the counter in the same struct proto as the master
1548                  * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1549                  * is the same as sk->sk_prot->socks, as this field was copied
1550                  * with memcpy).
1551                  *
1552                  * This _changes_ the previous behaviour, where
1553                  * tcp_create_openreq_child always was incrementing the
1554                  * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1555                  * to be taken into account in all callers. -acme
1556                  */
1557                 sk_refcnt_debug_inc(newsk);
1558                 sk_set_socket(newsk, NULL);
1559                 newsk->sk_wq = NULL;
1560 
1561                 if (mem_cgroup_sockets_enabled && sk->sk_memcg)
1562                         sock_update_memcg(newsk);
1563 
1564                 if (newsk->sk_prot->sockets_allocated)
1565                         sk_sockets_allocated_inc(newsk);
1566 
1567                 if (sock_needs_netstamp(sk) &&
1568                     newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1569                         net_enable_timestamp();
1570         }
1571 out:
1572         return newsk;
1573 }
1574 EXPORT_SYMBOL_GPL(sk_clone_lock);
1575 
1576 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1577 {
1578         u32 max_segs = 1;
1579 
1580         sk_dst_set(sk, dst);
1581         sk->sk_route_caps = dst->dev->features;
1582         if (sk->sk_route_caps & NETIF_F_GSO)
1583                 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1584         sk->sk_route_caps &= ~sk->sk_route_nocaps;
1585         if (sk_can_gso(sk)) {
1586                 if (dst->header_len) {
1587                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1588                 } else {
1589                         sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1590                         sk->sk_gso_max_size = dst->dev->gso_max_size;
1591                         max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1592                 }
1593         }
1594         sk->sk_gso_max_segs = max_segs;
1595 }
1596 EXPORT_SYMBOL_GPL(sk_setup_caps);
1597 
1598 /*
1599  *      Simple resource managers for sockets.
1600  */
1601 
1602 
1603 /*
1604  * Write buffer destructor automatically called from kfree_skb.
1605  */
1606 void sock_wfree(struct sk_buff *skb)
1607 {
1608         struct sock *sk = skb->sk;
1609         unsigned int len = skb->truesize;
1610 
1611         if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1612                 /*
1613                  * Keep a reference on sk_wmem_alloc, this will be released
1614                  * after sk_write_space() call
1615                  */
1616                 atomic_sub(len - 1, &sk->sk_wmem_alloc);
1617                 sk->sk_write_space(sk);
1618                 len = 1;
1619         }
1620         /*
1621          * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1622          * could not do because of in-flight packets
1623          */
1624         if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1625                 __sk_free(sk);
1626 }
1627 EXPORT_SYMBOL(sock_wfree);
1628 
1629 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1630 {
1631         skb_orphan(skb);
1632         skb->sk = sk;
1633 #ifdef CONFIG_INET
1634         if (unlikely(!sk_fullsock(sk))) {
1635                 skb->destructor = sock_edemux;
1636                 sock_hold(sk);
1637                 return;
1638         }
1639 #endif
1640         skb->destructor = sock_wfree;
1641         skb_set_hash_from_sk(skb, sk);
1642         /*
1643          * We used to take a refcount on sk, but following operation
1644          * is enough to guarantee sk_free() wont free this sock until
1645          * all in-flight packets are completed
1646          */
1647         atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1648 }
1649 EXPORT_SYMBOL(skb_set_owner_w);
1650 
1651 void skb_orphan_partial(struct sk_buff *skb)
1652 {
1653         /* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1654          * so we do not completely orphan skb, but transfert all
1655          * accounted bytes but one, to avoid unexpected reorders.
1656          */
1657         if (skb->destructor == sock_wfree
1658 #ifdef CONFIG_INET
1659             || skb->destructor == tcp_wfree
1660 #endif
1661                 ) {
1662                 atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1663                 skb->truesize = 1;
1664         } else {
1665                 skb_orphan(skb);
1666         }
1667 }
1668 EXPORT_SYMBOL(skb_orphan_partial);
1669 
1670 /*
1671  * Read buffer destructor automatically called from kfree_skb.
1672  */
1673 void sock_rfree(struct sk_buff *skb)
1674 {
1675         struct sock *sk = skb->sk;
1676         unsigned int len = skb->truesize;
1677 
1678         atomic_sub(len, &sk->sk_rmem_alloc);
1679         sk_mem_uncharge(sk, len);
1680 }
1681 EXPORT_SYMBOL(sock_rfree);
1682 
1683 /*
1684  * Buffer destructor for skbs that are not used directly in read or write
1685  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1686  */
1687 void sock_efree(struct sk_buff *skb)
1688 {
1689         sock_put(skb->sk);
1690 }
1691 EXPORT_SYMBOL(sock_efree);
1692 
1693 kuid_t sock_i_uid(struct sock *sk)
1694 {
1695         kuid_t uid;
1696 
1697         read_lock_bh(&sk->sk_callback_lock);
1698         uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1699         read_unlock_bh(&sk->sk_callback_lock);
1700         return uid;
1701 }
1702 EXPORT_SYMBOL(sock_i_uid);
1703 
1704 unsigned long sock_i_ino(struct sock *sk)
1705 {
1706         unsigned long ino;
1707 
1708         read_lock_bh(&sk->sk_callback_lock);
1709         ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1710         read_unlock_bh(&sk->sk_callback_lock);
1711         return ino;
1712 }
1713 EXPORT_SYMBOL(sock_i_ino);
1714 
1715 /*
1716  * Allocate a skb from the socket's send buffer.
1717  */
1718 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1719                              gfp_t priority)
1720 {
1721         if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1722                 struct sk_buff *skb = alloc_skb(size, priority);
1723                 if (skb) {
1724                         skb_set_owner_w(skb, sk);
1725                         return skb;
1726                 }
1727         }
1728         return NULL;
1729 }
1730 EXPORT_SYMBOL(sock_wmalloc);
1731 
1732 /*
1733  * Allocate a memory block from the socket's option memory buffer.
1734  */
1735 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1736 {
1737         if ((unsigned int)size <= sysctl_optmem_max &&
1738             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1739                 void *mem;
1740                 /* First do the add, to avoid the race if kmalloc
1741                  * might sleep.
1742                  */
1743                 atomic_add(size, &sk->sk_omem_alloc);
1744                 mem = kmalloc(size, priority);
1745                 if (mem)
1746                         return mem;
1747                 atomic_sub(size, &sk->sk_omem_alloc);
1748         }
1749         return NULL;
1750 }
1751 EXPORT_SYMBOL(sock_kmalloc);
1752 
1753 /* Free an option memory block. Note, we actually want the inline
1754  * here as this allows gcc to detect the nullify and fold away the
1755  * condition entirely.
1756  */
1757 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
1758                                   const bool nullify)
1759 {
1760         if (WARN_ON_ONCE(!mem))
1761                 return;
1762         if (nullify)
1763                 kzfree(mem);
1764         else
1765                 kfree(mem);
1766         atomic_sub(size, &sk->sk_omem_alloc);
1767 }
1768 
1769 void sock_kfree_s(struct sock *sk, void *mem, int size)
1770 {
1771         __sock_kfree_s(sk, mem, size, false);
1772 }
1773 EXPORT_SYMBOL(sock_kfree_s);
1774 
1775 void sock_kzfree_s(struct sock *sk, void *mem, int size)
1776 {
1777         __sock_kfree_s(sk, mem, size, true);
1778 }
1779 EXPORT_SYMBOL(sock_kzfree_s);
1780 
1781 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1782    I think, these locks should be removed for datagram sockets.
1783  */
1784 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1785 {
1786         DEFINE_WAIT(wait);
1787 
1788         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1789         for (;;) {
1790                 if (!timeo)
1791                         break;
1792                 if (signal_pending(current))
1793                         break;
1794                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1795                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1796                 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1797                         break;
1798                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1799                         break;
1800                 if (sk->sk_err)
1801                         break;
1802                 timeo = schedule_timeout(timeo);
1803         }
1804         finish_wait(sk_sleep(sk), &wait);
1805         return timeo;
1806 }
1807 
1808 
1809 /*
1810  *      Generic send/receive buffer handlers
1811  */
1812 
1813 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1814                                      unsigned long data_len, int noblock,
1815                                      int *errcode, int max_page_order)
1816 {
1817         struct sk_buff *skb;
1818         long timeo;
1819         int err;
1820 
1821         timeo = sock_sndtimeo(sk, noblock);
1822         for (;;) {
1823                 err = sock_error(sk);
1824                 if (err != 0)
1825                         goto failure;
1826 
1827                 err = -EPIPE;
1828                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1829                         goto failure;
1830 
1831                 if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
1832                         break;
1833 
1834                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1835                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1836                 err = -EAGAIN;
1837                 if (!timeo)
1838                         goto failure;
1839                 if (signal_pending(current))
1840                         goto interrupted;
1841                 timeo = sock_wait_for_wmem(sk, timeo);
1842         }
1843         skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
1844                                    errcode, sk->sk_allocation);
1845         if (skb)
1846                 skb_set_owner_w(skb, sk);
1847         return skb;
1848 
1849 interrupted:
1850         err = sock_intr_errno(timeo);
1851 failure:
1852         *errcode = err;
1853         return NULL;
1854 }
1855 EXPORT_SYMBOL(sock_alloc_send_pskb);
1856 
1857 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1858                                     int noblock, int *errcode)
1859 {
1860         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1861 }
1862 EXPORT_SYMBOL(sock_alloc_send_skb);
1863 
1864 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1865                    struct sockcm_cookie *sockc)
1866 {
1867         struct cmsghdr *cmsg;
1868 
1869         for_each_cmsghdr(cmsg, msg) {
1870                 if (!CMSG_OK(msg, cmsg))
1871                         return -EINVAL;
1872                 if (cmsg->cmsg_level != SOL_SOCKET)
1873                         continue;
1874                 switch (cmsg->cmsg_type) {
1875                 case SO_MARK:
1876                         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1877                                 return -EPERM;
1878                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
1879                                 return -EINVAL;
1880                         sockc->mark = *(u32 *)CMSG_DATA(cmsg);
1881                         break;
1882                 default:
1883                         return -EINVAL;
1884                 }
1885         }
1886         return 0;
1887 }
1888 EXPORT_SYMBOL(sock_cmsg_send);
1889 
1890 /* On 32bit arches, an skb frag is limited to 2^15 */
1891 #define SKB_FRAG_PAGE_ORDER     get_order(32768)
1892 
1893 /**
1894  * skb_page_frag_refill - check that a page_frag contains enough room
1895  * @sz: minimum size of the fragment we want to get
1896  * @pfrag: pointer to page_frag
1897  * @gfp: priority for memory allocation
1898  *
1899  * Note: While this allocator tries to use high order pages, there is
1900  * no guarantee that allocations succeed. Therefore, @sz MUST be
1901  * less or equal than PAGE_SIZE.
1902  */
1903 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
1904 {
1905         if (pfrag->page) {
1906                 if (atomic_read(&pfrag->page->_count) == 1) {
1907                         pfrag->offset = 0;
1908                         return true;
1909                 }
1910                 if (pfrag->offset + sz <= pfrag->size)
1911                         return true;
1912                 put_page(pfrag->page);
1913         }
1914 
1915         pfrag->offset = 0;
1916         if (SKB_FRAG_PAGE_ORDER) {
1917                 /* Avoid direct reclaim but allow kswapd to wake */
1918                 pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
1919                                           __GFP_COMP | __GFP_NOWARN |
1920                                           __GFP_NORETRY,
1921                                           SKB_FRAG_PAGE_ORDER);
1922                 if (likely(pfrag->page)) {
1923                         pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
1924                         return true;
1925                 }
1926         }
1927         pfrag->page = alloc_page(gfp);
1928         if (likely(pfrag->page)) {
1929                 pfrag->size = PAGE_SIZE;
1930                 return true;
1931         }
1932         return false;
1933 }
1934 EXPORT_SYMBOL(skb_page_frag_refill);
1935 
1936 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1937 {
1938         if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1939                 return true;
1940 
1941         sk_enter_memory_pressure(sk);
1942         sk_stream_moderate_sndbuf(sk);
1943         return false;
1944 }
1945 EXPORT_SYMBOL(sk_page_frag_refill);
1946 
1947 static void __lock_sock(struct sock *sk)
1948         __releases(&sk->sk_lock.slock)
1949         __acquires(&sk->sk_lock.slock)
1950 {
1951         DEFINE_WAIT(wait);
1952 
1953         for (;;) {
1954                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1955                                         TASK_UNINTERRUPTIBLE);
1956                 spin_unlock_bh(&sk->sk_lock.slock);
1957                 schedule();
1958                 spin_lock_bh(&sk->sk_lock.slock);
1959                 if (!sock_owned_by_user(sk))
1960                         break;
1961         }
1962         finish_wait(&sk->sk_lock.wq, &wait);
1963 }
1964 
1965 static void __release_sock(struct sock *sk)
1966         __releases(&sk->sk_lock.slock)
1967         __acquires(&sk->sk_lock.slock)
1968 {
1969         struct sk_buff *skb = sk->sk_backlog.head;
1970 
1971         do {
1972                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1973                 bh_unlock_sock(sk);
1974 
1975                 do {
1976                         struct sk_buff *next = skb->next;
1977 
1978                         prefetch(next);
1979                         WARN_ON_ONCE(skb_dst_is_noref(skb));
1980                         skb->next = NULL;
1981                         sk_backlog_rcv(sk, skb);
1982 
1983                         /*
1984                          * We are in process context here with softirqs
1985                          * disabled, use cond_resched_softirq() to preempt.
1986                          * This is safe to do because we've taken the backlog
1987                          * queue private:
1988                          */
1989                         cond_resched_softirq();
1990 
1991                         skb = next;
1992                 } while (skb != NULL);
1993 
1994                 bh_lock_sock(sk);
1995         } while ((skb = sk->sk_backlog.head) != NULL);
1996 
1997         /*
1998          * Doing the zeroing here guarantee we can not loop forever
1999          * while a wild producer attempts to flood us.
2000          */
2001         sk->sk_backlog.len = 0;
2002 }
2003 
2004 /**
2005  * sk_wait_data - wait for data to arrive at sk_receive_queue
2006  * @sk:    sock to wait on
2007  * @timeo: for how long
2008  * @skb:   last skb seen on sk_receive_queue
2009  *
2010  * Now socket state including sk->sk_err is changed only under lock,
2011  * hence we may omit checks after joining wait queue.
2012  * We check receive queue before schedule() only as optimization;
2013  * it is very likely that release_sock() added new data.
2014  */
2015 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2016 {
2017         int rc;
2018         DEFINE_WAIT(wait);
2019 
2020         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2021         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2022         rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb);
2023         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2024         finish_wait(sk_sleep(sk), &wait);
2025         return rc;
2026 }
2027 EXPORT_SYMBOL(sk_wait_data);
2028 
2029 /**
2030  *      __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2031  *      @sk: socket
2032  *      @size: memory size to allocate
2033  *      @kind: allocation type
2034  *
2035  *      If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2036  *      rmem allocation. This function assumes that protocols which have
2037  *      memory_pressure use sk_wmem_queued as write buffer accounting.
2038  */
2039 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2040 {
2041         struct proto *prot = sk->sk_prot;
2042         int amt = sk_mem_pages(size);
2043         long allocated;
2044 
2045         sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
2046 
2047         allocated = sk_memory_allocated_add(sk, amt);
2048 
2049         if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2050             !mem_cgroup_charge_skmem(sk->sk_memcg, amt))
2051                 goto suppress_allocation;
2052 
2053         /* Under limit. */
2054         if (allocated <= sk_prot_mem_limits(sk, 0)) {
2055                 sk_leave_memory_pressure(sk);
2056                 return 1;
2057         }
2058 
2059         /* Under pressure. */
2060         if (allocated > sk_prot_mem_limits(sk, 1))
2061                 sk_enter_memory_pressure(sk);
2062 
2063         /* Over hard limit. */
2064         if (allocated > sk_prot_mem_limits(sk, 2))
2065                 goto suppress_allocation;
2066 
2067         /* guarantee minimum buffer size under pressure */
2068         if (kind == SK_MEM_RECV) {
2069                 if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2070                         return 1;
2071 
2072         } else { /* SK_MEM_SEND */
2073                 if (sk->sk_type == SOCK_STREAM) {
2074                         if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2075                                 return 1;
2076                 } else if (atomic_read(&sk->sk_wmem_alloc) <
2077                            prot->sysctl_wmem[0])
2078                                 return 1;
2079         }
2080 
2081         if (sk_has_memory_pressure(sk)) {
2082                 int alloc;
2083 
2084                 if (!sk_under_memory_pressure(sk))
2085                         return 1;
2086                 alloc = sk_sockets_allocated_read_positive(sk);
2087                 if (sk_prot_mem_limits(sk, 2) > alloc *
2088                     sk_mem_pages(sk->sk_wmem_queued +
2089                                  atomic_read(&sk->sk_rmem_alloc) +
2090                                  sk->sk_forward_alloc))
2091                         return 1;
2092         }
2093 
2094 suppress_allocation:
2095 
2096         if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2097                 sk_stream_moderate_sndbuf(sk);
2098 
2099                 /* Fail only if socket is _under_ its sndbuf.
2100                  * In this case we cannot block, so that we have to fail.
2101                  */
2102                 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2103                         return 1;
2104         }
2105 
2106         trace_sock_exceed_buf_limit(sk, prot, allocated);
2107 
2108         /* Alas. Undo changes. */
2109         sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2110 
2111         sk_memory_allocated_sub(sk, amt);
2112 
2113         if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2114                 mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2115 
2116         return 0;
2117 }
2118 EXPORT_SYMBOL(__sk_mem_schedule);
2119 
2120 /**
2121  *      __sk_mem_reclaim - reclaim memory_allocated
2122  *      @sk: socket
2123  *      @amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2124  */
2125 void __sk_mem_reclaim(struct sock *sk, int amount)
2126 {
2127         amount >>= SK_MEM_QUANTUM_SHIFT;
2128         sk_memory_allocated_sub(sk, amount);
2129         sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2130 
2131         if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2132                 mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2133 
2134         if (sk_under_memory_pressure(sk) &&
2135             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2136                 sk_leave_memory_pressure(sk);
2137 }
2138 EXPORT_SYMBOL(__sk_mem_reclaim);
2139 
2140 
2141 /*
2142  * Set of default routines for initialising struct proto_ops when
2143  * the protocol does not support a particular function. In certain
2144  * cases where it makes no sense for a protocol to have a "do nothing"
2145  * function, some default processing is provided.
2146  */
2147 
2148 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2149 {
2150         return -EOPNOTSUPP;
2151 }
2152 EXPORT_SYMBOL(sock_no_bind);
2153 
2154 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2155                     int len, int flags)
2156 {
2157         return -EOPNOTSUPP;
2158 }
2159 EXPORT_SYMBOL(sock_no_connect);
2160 
2161 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2162 {
2163         return -EOPNOTSUPP;
2164 }
2165 EXPORT_SYMBOL(sock_no_socketpair);
2166 
2167 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2168 {
2169         return -EOPNOTSUPP;
2170 }
2171 EXPORT_SYMBOL(sock_no_accept);
2172 
2173 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2174                     int *len, int peer)
2175 {
2176         return -EOPNOTSUPP;
2177 }
2178 EXPORT_SYMBOL(sock_no_getname);
2179 
2180 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2181 {
2182         return 0;
2183 }
2184 EXPORT_SYMBOL(sock_no_poll);
2185 
2186 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2187 {
2188         return -EOPNOTSUPP;
2189 }
2190 EXPORT_SYMBOL(sock_no_ioctl);
2191 
2192 int sock_no_listen(struct socket *sock, int backlog)
2193 {
2194         return -EOPNOTSUPP;
2195 }
2196 EXPORT_SYMBOL(sock_no_listen);
2197 
2198 int sock_no_shutdown(struct socket *sock, int how)
2199 {
2200         return -EOPNOTSUPP;
2201 }
2202 EXPORT_SYMBOL(sock_no_shutdown);
2203 
2204 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2205                     char __user *optval, unsigned int optlen)
2206 {
2207         return -EOPNOTSUPP;
2208 }
2209 EXPORT_SYMBOL(sock_no_setsockopt);
2210 
2211 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2212                     char __user *optval, int __user *optlen)
2213 {
2214         return -EOPNOTSUPP;
2215 }
2216 EXPORT_SYMBOL(sock_no_getsockopt);
2217 
2218 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2219 {
2220         return -EOPNOTSUPP;
2221 }
2222 EXPORT_SYMBOL(sock_no_sendmsg);
2223 
2224 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2225                     int flags)
2226 {
2227         return -EOPNOTSUPP;
2228 }
2229 EXPORT_SYMBOL(sock_no_recvmsg);
2230 
2231 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2232 {
2233         /* Mirror missing mmap method error code */
2234         return -ENODEV;
2235 }
2236 EXPORT_SYMBOL(sock_no_mmap);
2237 
2238 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2239 {
2240         ssize_t res;
2241         struct msghdr msg = {.msg_flags = flags};
2242         struct kvec iov;
2243         char *kaddr = kmap(page);
2244         iov.iov_base = kaddr + offset;
2245         iov.iov_len = size;
2246         res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2247         kunmap(page);
2248         return res;
2249 }
2250 EXPORT_SYMBOL(sock_no_sendpage);
2251 
2252 /*
2253  *      Default Socket Callbacks
2254  */
2255 
2256 static void sock_def_wakeup(struct sock *sk)
2257 {
2258         struct socket_wq *wq;
2259 
2260         rcu_read_lock();
2261         wq = rcu_dereference(sk->sk_wq);
2262         if (skwq_has_sleeper(wq))
2263                 wake_up_interruptible_all(&wq->wait);
2264         rcu_read_unlock();
2265 }
2266 
2267 static void sock_def_error_report(struct sock *sk)
2268 {
2269         struct socket_wq *wq;
2270 
2271         rcu_read_lock();
2272         wq = rcu_dereference(sk->sk_wq);
2273         if (skwq_has_sleeper(wq))
2274                 wake_up_interruptible_poll(&wq->wait, POLLERR);
2275         sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2276         rcu_read_unlock();
2277 }
2278 
2279 static void sock_def_readable(struct sock *sk)
2280 {
2281         struct socket_wq *wq;
2282 
2283         rcu_read_lock();
2284         wq = rcu_dereference(sk->sk_wq);
2285         if (skwq_has_sleeper(wq))
2286                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2287                                                 POLLRDNORM | POLLRDBAND);
2288         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2289         rcu_read_unlock();
2290 }
2291 
2292 static void sock_def_write_space(struct sock *sk)
2293 {
2294         struct socket_wq *wq;
2295 
2296         rcu_read_lock();
2297 
2298         /* Do not wake up a writer until he can make "significant"
2299          * progress.  --DaveM
2300          */
2301         if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2302                 wq = rcu_dereference(sk->sk_wq);
2303                 if (skwq_has_sleeper(wq))
2304                         wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2305                                                 POLLWRNORM | POLLWRBAND);
2306 
2307                 /* Should agree with poll, otherwise some programs break */
2308                 if (sock_writeable(sk))
2309                         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2310         }
2311 
2312         rcu_read_unlock();
2313 }
2314 
2315 static void sock_def_destruct(struct sock *sk)
2316 {
2317 }
2318 
2319 void sk_send_sigurg(struct sock *sk)
2320 {
2321         if (sk->sk_socket && sk->sk_socket->file)
2322                 if (send_sigurg(&sk->sk_socket->file->f_owner))
2323                         sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2324 }
2325 EXPORT_SYMBOL(sk_send_sigurg);
2326 
2327 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2328                     unsigned long expires)
2329 {
2330         if (!mod_timer(timer, expires))
2331                 sock_hold(sk);
2332 }
2333 EXPORT_SYMBOL(sk_reset_timer);
2334 
2335 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2336 {
2337         if (del_timer(timer))
2338                 __sock_put(sk);
2339 }
2340 EXPORT_SYMBOL(sk_stop_timer);
2341 
2342 void sock_init_data(struct socket *sock, struct sock *sk)
2343 {
2344         skb_queue_head_init(&sk->sk_receive_queue);
2345         skb_queue_head_init(&sk->sk_write_queue);
2346         skb_queue_head_init(&sk->sk_error_queue);
2347 
2348         sk->sk_send_head        =       NULL;
2349 
2350         init_timer(&sk->sk_timer);
2351 
2352         sk->sk_allocation       =       GFP_KERNEL;
2353         sk->sk_rcvbuf           =       sysctl_rmem_default;
2354         sk->sk_sndbuf           =       sysctl_wmem_default;
2355         sk->sk_state            =       TCP_CLOSE;
2356         sk_set_socket(sk, sock);
2357 
2358         sock_set_flag(sk, SOCK_ZAPPED);
2359 
2360         if (sock) {
2361                 sk->sk_type     =       sock->type;
2362                 sk->sk_wq       =       sock->wq;
2363                 sock->sk        =       sk;
2364         } else
2365                 sk->sk_wq       =       NULL;
2366 
2367         rwlock_init(&sk->sk_callback_lock);
2368         lockdep_set_class_and_name(&sk->sk_callback_lock,
2369                         af_callback_keys + sk->sk_family,
2370                         af_family_clock_key_strings[sk->sk_family]);
2371 
2372         sk->sk_state_change     =       sock_def_wakeup;
2373         sk->sk_data_ready       =       sock_def_readable;
2374         sk->sk_write_space      =       sock_def_write_space;
2375         sk->sk_error_report     =       sock_def_error_report;
2376         sk->sk_destruct         =       sock_def_destruct;
2377 
2378         sk->sk_frag.page        =       NULL;
2379         sk->sk_frag.offset      =       0;
2380         sk->sk_peek_off         =       -1;
2381 
2382         sk->sk_peer_pid         =       NULL;
2383         sk->sk_peer_cred        =       NULL;
2384         sk->sk_write_pending    =       0;
2385         sk->sk_rcvlowat         =       1;
2386         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
2387         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
2388 
2389         sk->sk_stamp = ktime_set(-1L, 0);
2390 
2391 #ifdef CONFIG_NET_RX_BUSY_POLL
2392         sk->sk_napi_id          =       0;
2393         sk->sk_ll_usec          =       sysctl_net_busy_read;
2394 #endif
2395 
2396         sk->sk_max_pacing_rate = ~0U;
2397         sk->sk_pacing_rate = ~0U;
2398         sk->sk_incoming_cpu = -1;
2399         /*
2400          * Before updating sk_refcnt, we must commit prior changes to memory
2401          * (Documentation/RCU/rculist_nulls.txt for details)
2402          */
2403         smp_wmb();
2404         atomic_set(&sk->sk_refcnt, 1);
2405         atomic_set(&sk->sk_drops, 0);
2406 }
2407 EXPORT_SYMBOL(sock_init_data);
2408 
2409 void lock_sock_nested(struct sock *sk, int subclass)
2410 {
2411         might_sleep();
2412         spin_lock_bh(&sk->sk_lock.slock);
2413         if (sk->sk_lock.owned)
2414                 __lock_sock(sk);
2415         sk->sk_lock.owned = 1;
2416         spin_unlock(&sk->sk_lock.slock);
2417         /*
2418          * The sk_lock has mutex_lock() semantics here:
2419          */
2420         mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2421         local_bh_enable();
2422 }
2423 EXPORT_SYMBOL(lock_sock_nested);
2424 
2425 void release_sock(struct sock *sk)
2426 {
2427         /*
2428          * The sk_lock has mutex_unlock() semantics:
2429          */
2430         mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2431 
2432         spin_lock_bh(&sk->sk_lock.slock);
2433         if (sk->sk_backlog.tail)
2434                 __release_sock(sk);
2435 
2436         /* Warning : release_cb() might need to release sk ownership,
2437          * ie call sock_release_ownership(sk) before us.
2438          */
2439         if (sk->sk_prot->release_cb)
2440                 sk->sk_prot->release_cb(sk);
2441 
2442         sock_release_ownership(sk);
2443         if (waitqueue_active(&sk->sk_lock.wq))
2444                 wake_up(&sk->sk_lock.wq);
2445         spin_unlock_bh(&sk->sk_lock.slock);
2446 }
2447 EXPORT_SYMBOL(release_sock);
2448 
2449 /**
2450  * lock_sock_fast - fast version of lock_sock
2451  * @sk: socket
2452  *
2453  * This version should be used for very small section, where process wont block
2454  * return false if fast path is taken
2455  *   sk_lock.slock locked, owned = 0, BH disabled
2456  * return true if slow path is taken
2457  *   sk_lock.slock unlocked, owned = 1, BH enabled
2458  */
2459 bool lock_sock_fast(struct sock *sk)
2460 {
2461         might_sleep();
2462         spin_lock_bh(&sk->sk_lock.slock);
2463 
2464         if (!sk->sk_lock.owned)
2465                 /*
2466                  * Note : We must disable BH
2467                  */
2468                 return false;
2469 
2470         __lock_sock(sk);
2471         sk->sk_lock.owned = 1;
2472         spin_unlock(&sk->sk_lock.slock);
2473         /*
2474          * The sk_lock has mutex_lock() semantics here:
2475          */
2476         mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2477         local_bh_enable();
2478         return true;
2479 }
2480 EXPORT_SYMBOL(lock_sock_fast);
2481 
2482 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2483 {
2484         struct timeval tv;
2485         if (!sock_flag(sk, SOCK_TIMESTAMP))
2486                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2487         tv = ktime_to_timeval(sk->sk_stamp);
2488         if (tv.tv_sec == -1)
2489                 return -ENOENT;
2490         if (tv.tv_sec == 0) {
2491                 sk->sk_stamp = ktime_get_real();
2492                 tv = ktime_to_timeval(sk->sk_stamp);
2493         }
2494         return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2495 }
2496 EXPORT_SYMBOL(sock_get_timestamp);
2497 
2498 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2499 {
2500         struct timespec ts;
2501         if (!sock_flag(sk, SOCK_TIMESTAMP))
2502                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2503         ts = ktime_to_timespec(sk->sk_stamp);
2504         if (ts.tv_sec == -1)
2505                 return -ENOENT;
2506         if (ts.tv_sec == 0) {
2507                 sk->sk_stamp = ktime_get_real();
2508                 ts = ktime_to_timespec(sk->sk_stamp);
2509         }
2510         return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2511 }
2512 EXPORT_SYMBOL(sock_get_timestampns);
2513 
2514 void sock_enable_timestamp(struct sock *sk, int flag)
2515 {
2516         if (!sock_flag(sk, flag)) {
2517                 unsigned long previous_flags = sk->sk_flags;
2518 
2519                 sock_set_flag(sk, flag);
2520                 /*
2521                  * we just set one of the two flags which require net
2522                  * time stamping, but time stamping might have been on
2523                  * already because of the other one
2524                  */
2525                 if (sock_needs_netstamp(sk) &&
2526                     !(previous_flags & SK_FLAGS_TIMESTAMP))
2527                         net_enable_timestamp();
2528         }
2529 }
2530 
2531 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2532                        int level, int type)
2533 {
2534         struct sock_exterr_skb *serr;
2535         struct sk_buff *skb;
2536         int copied, err;
2537 
2538         err = -EAGAIN;
2539         skb = sock_dequeue_err_skb(sk);
2540         if (skb == NULL)
2541                 goto out;
2542 
2543         copied = skb->len;
2544         if (copied > len) {
2545                 msg->msg_flags |= MSG_TRUNC;
2546                 copied = len;
2547         }
2548         err = skb_copy_datagram_msg(skb, 0, msg, copied);
2549         if (err)
2550                 goto out_free_skb;
2551 
2552         sock_recv_timestamp(msg, sk, skb);
2553 
2554         serr = SKB_EXT_ERR(skb);
2555         put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2556 
2557         msg->msg_flags |= MSG_ERRQUEUE;
2558         err = copied;
2559 
2560 out_free_skb:
2561         kfree_skb(skb);
2562 out:
2563         return err;
2564 }
2565 EXPORT_SYMBOL(sock_recv_errqueue);
2566 
2567 /*
2568  *      Get a socket option on an socket.
2569  *
2570  *      FIX: POSIX 1003.1g is very ambiguous here. It states that
2571  *      asynchronous errors should be reported by getsockopt. We assume
2572  *      this means if you specify SO_ERROR (otherwise whats the point of it).
2573  */
2574 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2575                            char __user *optval, int __user *optlen)
2576 {
2577         struct sock *sk = sock->sk;
2578 
2579         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2580 }
2581 EXPORT_SYMBOL(sock_common_getsockopt);
2582 
2583 #ifdef CONFIG_COMPAT
2584 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2585                                   char __user *optval, int __user *optlen)
2586 {
2587         struct sock *sk = sock->sk;
2588 
2589         if (sk->sk_prot->compat_getsockopt != NULL)
2590                 return sk->sk_prot->compat_getsockopt(sk, level, optname,
2591                                                       optval, optlen);
2592         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2593 }
2594 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2595 #endif
2596 
2597 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
2598                         int flags)
2599 {
2600         struct sock *sk = sock->sk;
2601         int addr_len = 0;
2602         int err;
2603 
2604         err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
2605                                    flags & ~MSG_DONTWAIT, &addr_len);
2606         if (err >= 0)
2607                 msg->msg_namelen = addr_len;
2608         return err;
2609 }
2610 EXPORT_SYMBOL(sock_common_recvmsg);
2611 
2612 /*
2613  *      Set socket options on an inet socket.
2614  */
2615 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2616                            char __user *optval, unsigned int optlen)
2617 {
2618         struct sock *sk = sock->sk;
2619 
2620         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2621 }
2622 EXPORT_SYMBOL(sock_common_setsockopt);
2623 
2624 #ifdef CONFIG_COMPAT
2625 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2626                                   char __user *optval, unsigned int optlen)
2627 {
2628         struct sock *sk = sock->sk;
2629 
2630         if (sk->sk_prot->compat_setsockopt != NULL)
2631                 return sk->sk_prot->compat_setsockopt(sk, level, optname,
2632                                                       optval, optlen);
2633         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2634 }
2635 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2636 #endif
2637 
2638 void sk_common_release(struct sock *sk)
2639 {
2640         if (sk->sk_prot->destroy)
2641                 sk->sk_prot->destroy(sk);
2642 
2643         /*
2644          * Observation: when sock_common_release is called, processes have
2645          * no access to socket. But net still has.
2646          * Step one, detach it from networking:
2647          *
2648          * A. Remove from hash tables.
2649          */
2650 
2651         sk->sk_prot->unhash(sk);
2652 
2653         /*
2654          * In this point socket cannot receive new packets, but it is possible
2655          * that some packets are in flight because some CPU runs receiver and
2656          * did hash table lookup before we unhashed socket. They will achieve
2657          * receive queue and will be purged by socket destructor.
2658          *
2659          * Also we still have packets pending on receive queue and probably,
2660          * our own packets waiting in device queues. sock_destroy will drain
2661          * receive queue, but transmitted packets will delay socket destruction
2662          * until the last reference will be released.
2663          */
2664 
2665         sock_orphan(sk);
2666 
2667         xfrm_sk_free_policy(sk);
2668 
2669         sk_refcnt_debug_release(sk);
2670 
2671         if (sk->sk_frag.page) {
2672                 put_page(sk->sk_frag.page);
2673                 sk->sk_frag.page = NULL;
2674         }
2675 
2676         sock_put(sk);
2677 }
2678 EXPORT_SYMBOL(sk_common_release);
2679 
2680 #ifdef CONFIG_PROC_FS
2681 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
2682 struct prot_inuse {
2683         int val[PROTO_INUSE_NR];
2684 };
2685 
2686 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2687 
2688 #ifdef CONFIG_NET_NS
2689 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2690 {
2691         __this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2692 }
2693 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2694 
2695 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2696 {
2697         int cpu, idx = prot->inuse_idx;
2698         int res = 0;
2699 
2700         for_each_possible_cpu(cpu)
2701                 res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2702 
2703         return res >= 0 ? res : 0;
2704 }
2705 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2706 
2707 static int __net_init sock_inuse_init_net(struct net *net)
2708 {
2709         net->core.inuse = alloc_percpu(struct prot_inuse);
2710         return net->core.inuse ? 0 : -ENOMEM;
2711 }
2712 
2713 static void __net_exit sock_inuse_exit_net(struct net *net)
2714 {
2715         free_percpu(net->core.inuse);
2716 }
2717 
2718 static struct pernet_operations net_inuse_ops = {
2719         .init = sock_inuse_init_net,
2720         .exit = sock_inuse_exit_net,
2721 };
2722 
2723 static __init int net_inuse_init(void)
2724 {
2725         if (register_pernet_subsys(&net_inuse_ops))
2726                 panic("Cannot initialize net inuse counters");
2727 
2728         return 0;
2729 }
2730 
2731 core_initcall(net_inuse_init);
2732 #else
2733 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2734 
2735 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2736 {
2737         __this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2738 }
2739 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2740 
2741 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2742 {
2743         int cpu, idx = prot->inuse_idx;
2744         int res = 0;
2745 
2746         for_each_possible_cpu(cpu)
2747                 res += per_cpu(prot_inuse, cpu).val[idx];
2748 
2749         return res >= 0 ? res : 0;
2750 }
2751 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2752 #endif
2753 
2754 static void assign_proto_idx(struct proto *prot)
2755 {
2756         prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2757 
2758         if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2759                 pr_err("PROTO_INUSE_NR exhausted\n");
2760                 return;
2761         }
2762 
2763         set_bit(prot->inuse_idx, proto_inuse_idx);
2764 }
2765 
2766 static void release_proto_idx(struct proto *prot)
2767 {
2768         if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2769                 clear_bit(prot->inuse_idx, proto_inuse_idx);
2770 }
2771 #else
2772 static inline void assign_proto_idx(struct proto *prot)
2773 {
2774 }
2775 
2776 static inline void release_proto_idx(struct proto *prot)
2777 {
2778 }
2779 #endif
2780 
2781 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
2782 {
2783         if (!rsk_prot)
2784                 return;
2785         kfree(rsk_prot->slab_name);
2786         rsk_prot->slab_name = NULL;
2787         kmem_cache_destroy(rsk_prot->slab);
2788         rsk_prot->slab = NULL;
2789 }
2790 
2791 static int req_prot_init(const struct proto *prot)
2792 {
2793         struct request_sock_ops *rsk_prot = prot->rsk_prot;
2794 
2795         if (!rsk_prot)
2796                 return 0;
2797 
2798         rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
2799                                         prot->name);
2800         if (!rsk_prot->slab_name)
2801                 return -ENOMEM;
2802 
2803         rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
2804                                            rsk_prot->obj_size, 0,
2805                                            prot->slab_flags, NULL);
2806 
2807         if (!rsk_prot->slab) {
2808                 pr_crit("%s: Can't create request sock SLAB cache!\n",
2809                         prot->name);
2810                 return -ENOMEM;
2811         }
2812         return 0;
2813 }
2814 
2815 int proto_register(struct proto *prot, int alloc_slab)
2816 {
2817         if (alloc_slab) {
2818                 prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2819                                         SLAB_HWCACHE_ALIGN | prot->slab_flags,
2820                                         NULL);
2821 
2822                 if (prot->slab == NULL) {
2823                         pr_crit("%s: Can't create sock SLAB cache!\n",
2824                                 prot->name);
2825                         goto out;
2826                 }
2827 
2828                 if (req_prot_init(prot))
2829                         goto out_free_request_sock_slab;
2830 
2831                 if (prot->twsk_prot != NULL) {
2832                         prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2833 
2834                         if (prot->twsk_prot->twsk_slab_name == NULL)
2835                                 goto out_free_request_sock_slab;
2836 
2837                         prot->twsk_prot->twsk_slab =
2838                                 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2839                                                   prot->twsk_prot->twsk_obj_size,
2840                                                   0,
2841                                                   prot->slab_flags,
2842                                                   NULL);
2843                         if (prot->twsk_prot->twsk_slab == NULL)
2844                                 goto out_free_timewait_sock_slab_name;
2845                 }
2846         }
2847 
2848         mutex_lock(&proto_list_mutex);
2849         list_add(&prot->node, &proto_list);
2850         assign_proto_idx(prot);
2851         mutex_unlock(&proto_list_mutex);
2852         return 0;
2853 
2854 out_free_timewait_sock_slab_name:
2855         kfree(prot->twsk_prot->twsk_slab_name);
2856 out_free_request_sock_slab:
2857         req_prot_cleanup(prot->rsk_prot);
2858 
2859         kmem_cache_destroy(prot->slab);
2860         prot->slab = NULL;
2861 out:
2862         return -ENOBUFS;
2863 }
2864 EXPORT_SYMBOL(proto_register);
2865 
2866 void proto_unregister(struct proto *prot)
2867 {
2868         mutex_lock(&proto_list_mutex);
2869         release_proto_idx(prot);
2870         list_del(&prot->node);
2871         mutex_unlock(&proto_list_mutex);
2872 
2873         kmem_cache_destroy(prot->slab);
2874         prot->slab = NULL;
2875 
2876         req_prot_cleanup(prot->rsk_prot);
2877 
2878         if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2879                 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2880                 kfree(prot->twsk_prot->twsk_slab_name);
2881                 prot->twsk_prot->twsk_slab = NULL;
2882         }
2883 }
2884 EXPORT_SYMBOL(proto_unregister);
2885 
2886 #ifdef CONFIG_PROC_FS
2887 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2888         __acquires(proto_list_mutex)
2889 {
2890         mutex_lock(&proto_list_mutex);
2891         return seq_list_start_head(&proto_list, *pos);
2892 }
2893 
2894 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2895 {
2896         return seq_list_next(v, &proto_list, pos);
2897 }
2898 
2899 static void proto_seq_stop(struct seq_file *seq, void *v)
2900         __releases(proto_list_mutex)
2901 {
2902         mutex_unlock(&proto_list_mutex);
2903 }
2904 
2905 static char proto_method_implemented(const void *method)
2906 {
2907         return method == NULL ? 'n' : 'y';
2908 }
2909 static long sock_prot_memory_allocated(struct proto *proto)
2910 {
2911         return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2912 }
2913 
2914 static char *sock_prot_memory_pressure(struct proto *proto)
2915 {
2916         return proto->memory_pressure != NULL ?
2917         proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2918 }
2919 
2920 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2921 {
2922 
2923         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2924                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2925                    proto->name,
2926                    proto->obj_size,
2927                    sock_prot_inuse_get(seq_file_net(seq), proto),
2928                    sock_prot_memory_allocated(proto),
2929                    sock_prot_memory_pressure(proto),
2930                    proto->max_header,
2931                    proto->slab == NULL ? "no" : "yes",
2932                    module_name(proto->owner),
2933                    proto_method_implemented(proto->close),
2934                    proto_method_implemented(proto->connect),
2935                    proto_method_implemented(proto->disconnect),
2936                    proto_method_implemented(proto->accept),
2937                    proto_method_implemented(proto->ioctl),
2938                    proto_method_implemented(proto->init),
2939                    proto_method_implemented(proto->destroy),
2940                    proto_method_implemented(proto->shutdown),
2941                    proto_method_implemented(proto->setsockopt),
2942                    proto_method_implemented(proto->getsockopt),
2943                    proto_method_implemented(proto->sendmsg),
2944                    proto_method_implemented(proto->recvmsg),
2945                    proto_method_implemented(proto->sendpage),
2946                    proto_method_implemented(proto->bind),
2947                    proto_method_implemented(proto->backlog_rcv),
2948                    proto_method_implemented(proto->hash),
2949                    proto_method_implemented(proto->unhash),
2950                    proto_method_implemented(proto->get_port),
2951                    proto_method_implemented(proto->enter_memory_pressure));
2952 }
2953 
2954 static int proto_seq_show(struct seq_file *seq, void *v)
2955 {
2956         if (v == &proto_list)
2957                 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2958                            "protocol",
2959                            "size",
2960                            "sockets",
2961                            "memory",
2962                            "press",
2963                            "maxhdr",
2964                            "slab",
2965                            "module",
2966                            "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2967         else
2968                 proto_seq_printf(seq, list_entry(v, struct proto, node));
2969         return 0;
2970 }
2971 
2972 static const struct seq_operations proto_seq_ops = {
2973         .start  = proto_seq_start,
2974         .next   = proto_seq_next,
2975         .stop   = proto_seq_stop,
2976         .show   = proto_seq_show,
2977 };
2978 
2979 static int proto_seq_open(struct inode *inode, struct file *file)
2980 {
2981         return seq_open_net(inode, file, &proto_seq_ops,
2982                             sizeof(struct seq_net_private));
2983 }
2984 
2985 static const struct file_operations proto_seq_fops = {
2986         .owner          = THIS_MODULE,
2987         .open           = proto_seq_open,
2988         .read           = seq_read,
2989         .llseek         = seq_lseek,
2990         .release        = seq_release_net,
2991 };
2992 
2993 static __net_init int proto_init_net(struct net *net)
2994 {
2995         if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
2996                 return -ENOMEM;
2997 
2998         return 0;
2999 }
3000 
3001 static __net_exit void proto_exit_net(struct net *net)
3002 {
3003         remove_proc_entry("protocols", net->proc_net);
3004 }
3005 
3006 
3007 static __net_initdata struct pernet_operations proto_net_ops = {
3008         .init = proto_init_net,
3009         .exit = proto_exit_net,
3010 };
3011 
3012 static int __init proto_init(void)
3013 {
3014         return register_pernet_subsys(&proto_net_ops);
3015 }
3016 
3017 subsys_initcall(proto_init);
3018 
3019 #endif /* PROC_FS */
3020 

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