Version:  2.0.40 2.2.26 2.4.37 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 4.6

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_KCM"      ,
225   "sk_lock-AF_MAX"
226 };
227 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
228   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
229   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
230   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
231   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
232   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
233   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
234   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
235   "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
236   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
237   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
238   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
239   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
240   "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG"      ,
241   "slock-AF_NFC"   , "slock-AF_VSOCK"    ,"slock-AF_KCM"       ,
242   "slock-AF_MAX"
243 };
244 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
245   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
246   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
247   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
248   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
249   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
250   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
251   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
252   "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
253   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
254   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
255   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
256   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
257   "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG"      ,
258   "clock-AF_NFC"   , "clock-AF_VSOCK"    , "clock-AF_KCM"      ,
259   "clock-AF_MAX"
260 };
261 
262 /*
263  * sk_callback_lock locking rules are per-address-family,
264  * so split the lock classes by using a per-AF key:
265  */
266 static struct lock_class_key af_callback_keys[AF_MAX];
267 
268 /* Take into consideration the size of the struct sk_buff overhead in the
269  * determination of these values, since that is non-constant across
270  * platforms.  This makes socket queueing behavior and performance
271  * not depend upon such differences.
272  */
273 #define _SK_MEM_PACKETS         256
274 #define _SK_MEM_OVERHEAD        SKB_TRUESIZE(256)
275 #define SK_WMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
276 #define SK_RMEM_MAX             (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
277 
278 /* Run time adjustable parameters. */
279 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
280 EXPORT_SYMBOL(sysctl_wmem_max);
281 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
282 EXPORT_SYMBOL(sysctl_rmem_max);
283 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
284 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
285 
286 /* Maximal space eaten by iovec or ancillary data plus some space */
287 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
288 EXPORT_SYMBOL(sysctl_optmem_max);
289 
290 int sysctl_tstamp_allow_data __read_mostly = 1;
291 
292 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
293 EXPORT_SYMBOL_GPL(memalloc_socks);
294 
295 /**
296  * sk_set_memalloc - sets %SOCK_MEMALLOC
297  * @sk: socket to set it on
298  *
299  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
300  * It's the responsibility of the admin to adjust min_free_kbytes
301  * to meet the requirements
302  */
303 void sk_set_memalloc(struct sock *sk)
304 {
305         sock_set_flag(sk, SOCK_MEMALLOC);
306         sk->sk_allocation |= __GFP_MEMALLOC;
307         static_key_slow_inc(&memalloc_socks);
308 }
309 EXPORT_SYMBOL_GPL(sk_set_memalloc);
310 
311 void sk_clear_memalloc(struct sock *sk)
312 {
313         sock_reset_flag(sk, SOCK_MEMALLOC);
314         sk->sk_allocation &= ~__GFP_MEMALLOC;
315         static_key_slow_dec(&memalloc_socks);
316 
317         /*
318          * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
319          * progress of swapping. SOCK_MEMALLOC may be cleared while
320          * it has rmem allocations due to the last swapfile being deactivated
321          * but there is a risk that the socket is unusable due to exceeding
322          * the rmem limits. Reclaim the reserves and obey rmem limits again.
323          */
324         sk_mem_reclaim(sk);
325 }
326 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
327 
328 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
329 {
330         int ret;
331         unsigned long pflags = current->flags;
332 
333         /* these should have been dropped before queueing */
334         BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
335 
336         current->flags |= PF_MEMALLOC;
337         ret = sk->sk_backlog_rcv(sk, skb);
338         tsk_restore_flags(current, pflags, PF_MEMALLOC);
339 
340         return ret;
341 }
342 EXPORT_SYMBOL(__sk_backlog_rcv);
343 
344 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
345 {
346         struct timeval tv;
347 
348         if (optlen < sizeof(tv))
349                 return -EINVAL;
350         if (copy_from_user(&tv, optval, sizeof(tv)))
351                 return -EFAULT;
352         if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
353                 return -EDOM;
354 
355         if (tv.tv_sec < 0) {
356                 static int warned __read_mostly;
357 
358                 *timeo_p = 0;
359                 if (warned < 10 && net_ratelimit()) {
360                         warned++;
361                         pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
362                                 __func__, current->comm, task_pid_nr(current));
363                 }
364                 return 0;
365         }
366         *timeo_p = MAX_SCHEDULE_TIMEOUT;
367         if (tv.tv_sec == 0 && tv.tv_usec == 0)
368                 return 0;
369         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
370                 *timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
371         return 0;
372 }
373 
374 static void sock_warn_obsolete_bsdism(const char *name)
375 {
376         static int warned;
377         static char warncomm[TASK_COMM_LEN];
378         if (strcmp(warncomm, current->comm) && warned < 5) {
379                 strcpy(warncomm,  current->comm);
380                 pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
381                         warncomm, name);
382                 warned++;
383         }
384 }
385 
386 static bool sock_needs_netstamp(const struct sock *sk)
387 {
388         switch (sk->sk_family) {
389         case AF_UNSPEC:
390         case AF_UNIX:
391                 return false;
392         default:
393                 return true;
394         }
395 }
396 
397 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
398 {
399         if (sk->sk_flags & flags) {
400                 sk->sk_flags &= ~flags;
401                 if (sock_needs_netstamp(sk) &&
402                     !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
403                         net_disable_timestamp();
404         }
405 }
406 
407 
408 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
409 {
410         int err;
411         unsigned long flags;
412         struct sk_buff_head *list = &sk->sk_receive_queue;
413 
414         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
415                 atomic_inc(&sk->sk_drops);
416                 trace_sock_rcvqueue_full(sk, skb);
417                 return -ENOMEM;
418         }
419 
420         err = sk_filter(sk, skb);
421         if (err)
422                 return err;
423 
424         if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
425                 atomic_inc(&sk->sk_drops);
426                 return -ENOBUFS;
427         }
428 
429         skb->dev = NULL;
430         skb_set_owner_r(skb, sk);
431 
432         /* we escape from rcu protected region, make sure we dont leak
433          * a norefcounted dst
434          */
435         skb_dst_force(skb);
436 
437         spin_lock_irqsave(&list->lock, flags);
438         sock_skb_set_dropcount(sk, skb);
439         __skb_queue_tail(list, skb);
440         spin_unlock_irqrestore(&list->lock, flags);
441 
442         if (!sock_flag(sk, SOCK_DEAD))
443                 sk->sk_data_ready(sk);
444         return 0;
445 }
446 EXPORT_SYMBOL(sock_queue_rcv_skb);
447 
448 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
449 {
450         int rc = NET_RX_SUCCESS;
451 
452         if (sk_filter(sk, skb))
453                 goto discard_and_relse;
454 
455         skb->dev = NULL;
456 
457         if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
458                 atomic_inc(&sk->sk_drops);
459                 goto discard_and_relse;
460         }
461         if (nested)
462                 bh_lock_sock_nested(sk);
463         else
464                 bh_lock_sock(sk);
465         if (!sock_owned_by_user(sk)) {
466                 /*
467                  * trylock + unlock semantics:
468                  */
469                 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
470 
471                 rc = sk_backlog_rcv(sk, skb);
472 
473                 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
474         } else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
475                 bh_unlock_sock(sk);
476                 atomic_inc(&sk->sk_drops);
477                 goto discard_and_relse;
478         }
479 
480         bh_unlock_sock(sk);
481 out:
482         sock_put(sk);
483         return rc;
484 discard_and_relse:
485         kfree_skb(skb);
486         goto out;
487 }
488 EXPORT_SYMBOL(sk_receive_skb);
489 
490 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
491 {
492         struct dst_entry *dst = __sk_dst_get(sk);
493 
494         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
495                 sk_tx_queue_clear(sk);
496                 RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
497                 dst_release(dst);
498                 return NULL;
499         }
500 
501         return dst;
502 }
503 EXPORT_SYMBOL(__sk_dst_check);
504 
505 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
506 {
507         struct dst_entry *dst = sk_dst_get(sk);
508 
509         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
510                 sk_dst_reset(sk);
511                 dst_release(dst);
512                 return NULL;
513         }
514 
515         return dst;
516 }
517 EXPORT_SYMBOL(sk_dst_check);
518 
519 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
520                                 int optlen)
521 {
522         int ret = -ENOPROTOOPT;
523 #ifdef CONFIG_NETDEVICES
524         struct net *net = sock_net(sk);
525         char devname[IFNAMSIZ];
526         int index;
527 
528         /* Sorry... */
529         ret = -EPERM;
530         if (!ns_capable(net->user_ns, CAP_NET_RAW))
531                 goto out;
532 
533         ret = -EINVAL;
534         if (optlen < 0)
535                 goto out;
536 
537         /* Bind this socket to a particular device like "eth0",
538          * as specified in the passed interface name. If the
539          * name is "" or the option length is zero the socket
540          * is not bound.
541          */
542         if (optlen > IFNAMSIZ - 1)
543                 optlen = IFNAMSIZ - 1;
544         memset(devname, 0, sizeof(devname));
545 
546         ret = -EFAULT;
547         if (copy_from_user(devname, optval, optlen))
548                 goto out;
549 
550         index = 0;
551         if (devname[0] != '\0') {
552                 struct net_device *dev;
553 
554                 rcu_read_lock();
555                 dev = dev_get_by_name_rcu(net, devname);
556                 if (dev)
557                         index = dev->ifindex;
558                 rcu_read_unlock();
559                 ret = -ENODEV;
560                 if (!dev)
561                         goto out;
562         }
563 
564         lock_sock(sk);
565         sk->sk_bound_dev_if = index;
566         sk_dst_reset(sk);
567         release_sock(sk);
568 
569         ret = 0;
570 
571 out:
572 #endif
573 
574         return ret;
575 }
576 
577 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
578                                 int __user *optlen, int len)
579 {
580         int ret = -ENOPROTOOPT;
581 #ifdef CONFIG_NETDEVICES
582         struct net *net = sock_net(sk);
583         char devname[IFNAMSIZ];
584 
585         if (sk->sk_bound_dev_if == 0) {
586                 len = 0;
587                 goto zero;
588         }
589 
590         ret = -EINVAL;
591         if (len < IFNAMSIZ)
592                 goto out;
593 
594         ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
595         if (ret)
596                 goto out;
597 
598         len = strlen(devname) + 1;
599 
600         ret = -EFAULT;
601         if (copy_to_user(optval, devname, len))
602                 goto out;
603 
604 zero:
605         ret = -EFAULT;
606         if (put_user(len, optlen))
607                 goto out;
608 
609         ret = 0;
610 
611 out:
612 #endif
613 
614         return ret;
615 }
616 
617 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
618 {
619         if (valbool)
620                 sock_set_flag(sk, bit);
621         else
622                 sock_reset_flag(sk, bit);
623 }
624 
625 bool sk_mc_loop(struct sock *sk)
626 {
627         if (dev_recursion_level())
628                 return false;
629         if (!sk)
630                 return true;
631         switch (sk->sk_family) {
632         case AF_INET:
633                 return inet_sk(sk)->mc_loop;
634 #if IS_ENABLED(CONFIG_IPV6)
635         case AF_INET6:
636                 return inet6_sk(sk)->mc_loop;
637 #endif
638         }
639         WARN_ON(1);
640         return true;
641 }
642 EXPORT_SYMBOL(sk_mc_loop);
643 
644 /*
645  *      This is meant for all protocols to use and covers goings on
646  *      at the socket level. Everything here is generic.
647  */
648 
649 int sock_setsockopt(struct socket *sock, int level, int optname,
650                     char __user *optval, unsigned int optlen)
651 {
652         struct sock *sk = sock->sk;
653         int val;
654         int valbool;
655         struct linger ling;
656         int ret = 0;
657 
658         /*
659          *      Options without arguments
660          */
661 
662         if (optname == SO_BINDTODEVICE)
663                 return sock_setbindtodevice(sk, optval, optlen);
664 
665         if (optlen < sizeof(int))
666                 return -EINVAL;
667 
668         if (get_user(val, (int __user *)optval))
669                 return -EFAULT;
670 
671         valbool = val ? 1 : 0;
672 
673         lock_sock(sk);
674 
675         switch (optname) {
676         case SO_DEBUG:
677                 if (val && !capable(CAP_NET_ADMIN))
678                         ret = -EACCES;
679                 else
680                         sock_valbool_flag(sk, SOCK_DBG, valbool);
681                 break;
682         case SO_REUSEADDR:
683                 sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
684                 break;
685         case SO_REUSEPORT:
686                 sk->sk_reuseport = valbool;
687                 break;
688         case SO_TYPE:
689         case SO_PROTOCOL:
690         case SO_DOMAIN:
691         case SO_ERROR:
692                 ret = -ENOPROTOOPT;
693                 break;
694         case SO_DONTROUTE:
695                 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
696                 break;
697         case SO_BROADCAST:
698                 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
699                 break;
700         case SO_SNDBUF:
701                 /* Don't error on this BSD doesn't and if you think
702                  * about it this is right. Otherwise apps have to
703                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
704                  * are treated in BSD as hints
705                  */
706                 val = min_t(u32, val, sysctl_wmem_max);
707 set_sndbuf:
708                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
709                 sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
710                 /* Wake up sending tasks if we upped the value. */
711                 sk->sk_write_space(sk);
712                 break;
713 
714         case SO_SNDBUFFORCE:
715                 if (!capable(CAP_NET_ADMIN)) {
716                         ret = -EPERM;
717                         break;
718                 }
719                 goto set_sndbuf;
720 
721         case SO_RCVBUF:
722                 /* Don't error on this BSD doesn't and if you think
723                  * about it this is right. Otherwise apps have to
724                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
725                  * are treated in BSD as hints
726                  */
727                 val = min_t(u32, val, sysctl_rmem_max);
728 set_rcvbuf:
729                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
730                 /*
731                  * We double it on the way in to account for
732                  * "struct sk_buff" etc. overhead.   Applications
733                  * assume that the SO_RCVBUF setting they make will
734                  * allow that much actual data to be received on that
735                  * socket.
736                  *
737                  * Applications are unaware that "struct sk_buff" and
738                  * other overheads allocate from the receive buffer
739                  * during socket buffer allocation.
740                  *
741                  * And after considering the possible alternatives,
742                  * returning the value we actually used in getsockopt
743                  * is the most desirable behavior.
744                  */
745                 sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
746                 break;
747 
748         case SO_RCVBUFFORCE:
749                 if (!capable(CAP_NET_ADMIN)) {
750                         ret = -EPERM;
751                         break;
752                 }
753                 goto set_rcvbuf;
754 
755         case SO_KEEPALIVE:
756 #ifdef CONFIG_INET
757                 if (sk->sk_protocol == IPPROTO_TCP &&
758                     sk->sk_type == SOCK_STREAM)
759                         tcp_set_keepalive(sk, valbool);
760 #endif
761                 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
762                 break;
763 
764         case SO_OOBINLINE:
765                 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
766                 break;
767 
768         case SO_NO_CHECK:
769                 sk->sk_no_check_tx = valbool;
770                 break;
771 
772         case SO_PRIORITY:
773                 if ((val >= 0 && val <= 6) ||
774                     ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
775                         sk->sk_priority = val;
776                 else
777                         ret = -EPERM;
778                 break;
779 
780         case SO_LINGER:
781                 if (optlen < sizeof(ling)) {
782                         ret = -EINVAL;  /* 1003.1g */
783                         break;
784                 }
785                 if (copy_from_user(&ling, optval, sizeof(ling))) {
786                         ret = -EFAULT;
787                         break;
788                 }
789                 if (!ling.l_onoff)
790                         sock_reset_flag(sk, SOCK_LINGER);
791                 else {
792 #if (BITS_PER_LONG == 32)
793                         if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
794                                 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
795                         else
796 #endif
797                                 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
798                         sock_set_flag(sk, SOCK_LINGER);
799                 }
800                 break;
801 
802         case SO_BSDCOMPAT:
803                 sock_warn_obsolete_bsdism("setsockopt");
804                 break;
805 
806         case SO_PASSCRED:
807                 if (valbool)
808                         set_bit(SOCK_PASSCRED, &sock->flags);
809                 else
810                         clear_bit(SOCK_PASSCRED, &sock->flags);
811                 break;
812 
813         case SO_TIMESTAMP:
814         case SO_TIMESTAMPNS:
815                 if (valbool)  {
816                         if (optname == SO_TIMESTAMP)
817                                 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
818                         else
819                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
820                         sock_set_flag(sk, SOCK_RCVTSTAMP);
821                         sock_enable_timestamp(sk, SOCK_TIMESTAMP);
822                 } else {
823                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
824                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
825                 }
826                 break;
827 
828         case SO_TIMESTAMPING:
829                 if (val & ~SOF_TIMESTAMPING_MASK) {
830                         ret = -EINVAL;
831                         break;
832                 }
833 
834                 if (val & SOF_TIMESTAMPING_OPT_ID &&
835                     !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
836                         if (sk->sk_protocol == IPPROTO_TCP &&
837                             sk->sk_type == SOCK_STREAM) {
838                                 if (sk->sk_state != TCP_ESTABLISHED) {
839                                         ret = -EINVAL;
840                                         break;
841                                 }
842                                 sk->sk_tskey = tcp_sk(sk)->snd_una;
843                         } else {
844                                 sk->sk_tskey = 0;
845                         }
846                 }
847                 sk->sk_tsflags = val;
848                 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
849                         sock_enable_timestamp(sk,
850                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
851                 else
852                         sock_disable_timestamp(sk,
853                                                (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
854                 break;
855 
856         case SO_RCVLOWAT:
857                 if (val < 0)
858                         val = INT_MAX;
859                 sk->sk_rcvlowat = val ? : 1;
860                 break;
861 
862         case SO_RCVTIMEO:
863                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
864                 break;
865 
866         case SO_SNDTIMEO:
867                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
868                 break;
869 
870         case SO_ATTACH_FILTER:
871                 ret = -EINVAL;
872                 if (optlen == sizeof(struct sock_fprog)) {
873                         struct sock_fprog fprog;
874 
875                         ret = -EFAULT;
876                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
877                                 break;
878 
879                         ret = sk_attach_filter(&fprog, sk);
880                 }
881                 break;
882 
883         case SO_ATTACH_BPF:
884                 ret = -EINVAL;
885                 if (optlen == sizeof(u32)) {
886                         u32 ufd;
887 
888                         ret = -EFAULT;
889                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
890                                 break;
891 
892                         ret = sk_attach_bpf(ufd, sk);
893                 }
894                 break;
895 
896         case SO_ATTACH_REUSEPORT_CBPF:
897                 ret = -EINVAL;
898                 if (optlen == sizeof(struct sock_fprog)) {
899                         struct sock_fprog fprog;
900 
901                         ret = -EFAULT;
902                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
903                                 break;
904 
905                         ret = sk_reuseport_attach_filter(&fprog, sk);
906                 }
907                 break;
908 
909         case SO_ATTACH_REUSEPORT_EBPF:
910                 ret = -EINVAL;
911                 if (optlen == sizeof(u32)) {
912                         u32 ufd;
913 
914                         ret = -EFAULT;
915                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
916                                 break;
917 
918                         ret = sk_reuseport_attach_bpf(ufd, sk);
919                 }
920                 break;
921 
922         case SO_DETACH_FILTER:
923                 ret = sk_detach_filter(sk);
924                 break;
925 
926         case SO_LOCK_FILTER:
927                 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
928                         ret = -EPERM;
929                 else
930                         sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
931                 break;
932 
933         case SO_PASSSEC:
934                 if (valbool)
935                         set_bit(SOCK_PASSSEC, &sock->flags);
936                 else
937                         clear_bit(SOCK_PASSSEC, &sock->flags);
938                 break;
939         case SO_MARK:
940                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
941                         ret = -EPERM;
942                 else
943                         sk->sk_mark = val;
944                 break;
945 
946         case SO_RXQ_OVFL:
947                 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
948                 break;
949 
950         case SO_WIFI_STATUS:
951                 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
952                 break;
953 
954         case SO_PEEK_OFF:
955                 if (sock->ops->set_peek_off)
956                         ret = sock->ops->set_peek_off(sk, val);
957                 else
958                         ret = -EOPNOTSUPP;
959                 break;
960 
961         case SO_NOFCS:
962                 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
963                 break;
964 
965         case SO_SELECT_ERR_QUEUE:
966                 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
967                 break;
968 
969 #ifdef CONFIG_NET_RX_BUSY_POLL
970         case SO_BUSY_POLL:
971                 /* allow unprivileged users to decrease the value */
972                 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
973                         ret = -EPERM;
974                 else {
975                         if (val < 0)
976                                 ret = -EINVAL;
977                         else
978                                 sk->sk_ll_usec = val;
979                 }
980                 break;
981 #endif
982 
983         case SO_MAX_PACING_RATE:
984                 sk->sk_max_pacing_rate = val;
985                 sk->sk_pacing_rate = min(sk->sk_pacing_rate,
986                                          sk->sk_max_pacing_rate);
987                 break;
988 
989         case SO_INCOMING_CPU:
990                 sk->sk_incoming_cpu = val;
991                 break;
992 
993         case SO_CNX_ADVICE:
994                 if (val == 1)
995                         dst_negative_advice(sk);
996                 break;
997         default:
998                 ret = -ENOPROTOOPT;
999                 break;
1000         }
1001         release_sock(sk);
1002         return ret;
1003 }
1004 EXPORT_SYMBOL(sock_setsockopt);
1005 
1006 
1007 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1008                           struct ucred *ucred)
1009 {
1010         ucred->pid = pid_vnr(pid);
1011         ucred->uid = ucred->gid = -1;
1012         if (cred) {
1013                 struct user_namespace *current_ns = current_user_ns();
1014 
1015                 ucred->uid = from_kuid_munged(current_ns, cred->euid);
1016                 ucred->gid = from_kgid_munged(current_ns, cred->egid);
1017         }
1018 }
1019 
1020 int sock_getsockopt(struct socket *sock, int level, int optname,
1021                     char __user *optval, int __user *optlen)
1022 {
1023         struct sock *sk = sock->sk;
1024 
1025         union {
1026                 int val;
1027                 struct linger ling;
1028                 struct timeval tm;
1029         } v;
1030 
1031         int lv = sizeof(int);
1032         int len;
1033 
1034         if (get_user(len, optlen))
1035                 return -EFAULT;
1036         if (len < 0)
1037                 return -EINVAL;
1038 
1039         memset(&v, 0, sizeof(v));
1040 
1041         switch (optname) {
1042         case SO_DEBUG:
1043                 v.val = sock_flag(sk, SOCK_DBG);
1044                 break;
1045 
1046         case SO_DONTROUTE:
1047                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
1048                 break;
1049 
1050         case SO_BROADCAST:
1051                 v.val = sock_flag(sk, SOCK_BROADCAST);
1052                 break;
1053 
1054         case SO_SNDBUF:
1055                 v.val = sk->sk_sndbuf;
1056                 break;
1057 
1058         case SO_RCVBUF:
1059                 v.val = sk->sk_rcvbuf;
1060                 break;
1061 
1062         case SO_REUSEADDR:
1063                 v.val = sk->sk_reuse;
1064                 break;
1065 
1066         case SO_REUSEPORT:
1067                 v.val = sk->sk_reuseport;
1068                 break;
1069 
1070         case SO_KEEPALIVE:
1071                 v.val = sock_flag(sk, SOCK_KEEPOPEN);
1072                 break;
1073 
1074         case SO_TYPE:
1075                 v.val = sk->sk_type;
1076                 break;
1077 
1078         case SO_PROTOCOL:
1079                 v.val = sk->sk_protocol;
1080                 break;
1081 
1082         case SO_DOMAIN:
1083                 v.val = sk->sk_family;
1084                 break;
1085 
1086         case SO_ERROR:
1087                 v.val = -sock_error(sk);
1088                 if (v.val == 0)
1089                         v.val = xchg(&sk->sk_err_soft, 0);
1090                 break;
1091 
1092         case SO_OOBINLINE:
1093                 v.val = sock_flag(sk, SOCK_URGINLINE);
1094                 break;
1095 
1096         case SO_NO_CHECK:
1097                 v.val = sk->sk_no_check_tx;
1098                 break;
1099 
1100         case SO_PRIORITY:
1101                 v.val = sk->sk_priority;
1102                 break;
1103 
1104         case SO_LINGER:
1105                 lv              = sizeof(v.ling);
1106                 v.ling.l_onoff  = sock_flag(sk, SOCK_LINGER);
1107                 v.ling.l_linger = sk->sk_lingertime / HZ;
1108                 break;
1109 
1110         case SO_BSDCOMPAT:
1111                 sock_warn_obsolete_bsdism("getsockopt");
1112                 break;
1113 
1114         case SO_TIMESTAMP:
1115                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1116                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1117                 break;
1118 
1119         case SO_TIMESTAMPNS:
1120                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1121                 break;
1122 
1123         case SO_TIMESTAMPING:
1124                 v.val = sk->sk_tsflags;
1125                 break;
1126 
1127         case SO_RCVTIMEO:
1128                 lv = sizeof(struct timeval);
1129                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1130                         v.tm.tv_sec = 0;
1131                         v.tm.tv_usec = 0;
1132                 } else {
1133                         v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1134                         v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1135                 }
1136                 break;
1137 
1138         case SO_SNDTIMEO:
1139                 lv = sizeof(struct timeval);
1140                 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1141                         v.tm.tv_sec = 0;
1142                         v.tm.tv_usec = 0;
1143                 } else {
1144                         v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1145                         v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1146                 }
1147                 break;
1148 
1149         case SO_RCVLOWAT:
1150                 v.val = sk->sk_rcvlowat;
1151                 break;
1152 
1153         case SO_SNDLOWAT:
1154                 v.val = 1;
1155                 break;
1156 
1157         case SO_PASSCRED:
1158                 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1159                 break;
1160 
1161         case SO_PEERCRED:
1162         {
1163                 struct ucred peercred;
1164                 if (len > sizeof(peercred))
1165                         len = sizeof(peercred);
1166                 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1167                 if (copy_to_user(optval, &peercred, len))
1168                         return -EFAULT;
1169                 goto lenout;
1170         }
1171 
1172         case SO_PEERNAME:
1173         {
1174                 char address[128];
1175 
1176                 if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1177                         return -ENOTCONN;
1178                 if (lv < len)
1179                         return -EINVAL;
1180                 if (copy_to_user(optval, address, len))
1181                         return -EFAULT;
1182                 goto lenout;
1183         }
1184 
1185         /* Dubious BSD thing... Probably nobody even uses it, but
1186          * the UNIX standard wants it for whatever reason... -DaveM
1187          */
1188         case SO_ACCEPTCONN:
1189                 v.val = sk->sk_state == TCP_LISTEN;
1190                 break;
1191 
1192         case SO_PASSSEC:
1193                 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1194                 break;
1195 
1196         case SO_PEERSEC:
1197                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1198 
1199         case SO_MARK:
1200                 v.val = sk->sk_mark;
1201                 break;
1202 
1203         case SO_RXQ_OVFL:
1204                 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1205                 break;
1206 
1207         case SO_WIFI_STATUS:
1208                 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1209                 break;
1210 
1211         case SO_PEEK_OFF:
1212                 if (!sock->ops->set_peek_off)
1213                         return -EOPNOTSUPP;
1214 
1215                 v.val = sk->sk_peek_off;
1216                 break;
1217         case SO_NOFCS:
1218                 v.val = sock_flag(sk, SOCK_NOFCS);
1219                 break;
1220 
1221         case SO_BINDTODEVICE:
1222                 return sock_getbindtodevice(sk, optval, optlen, len);
1223 
1224         case SO_GET_FILTER:
1225                 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1226                 if (len < 0)
1227                         return len;
1228 
1229                 goto lenout;
1230 
1231         case SO_LOCK_FILTER:
1232                 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1233                 break;
1234 
1235         case SO_BPF_EXTENSIONS:
1236                 v.val = bpf_tell_extensions();
1237                 break;
1238 
1239         case SO_SELECT_ERR_QUEUE:
1240                 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1241                 break;
1242 
1243 #ifdef CONFIG_NET_RX_BUSY_POLL
1244         case SO_BUSY_POLL:
1245                 v.val = sk->sk_ll_usec;
1246                 break;
1247 #endif
1248 
1249         case SO_MAX_PACING_RATE:
1250                 v.val = sk->sk_max_pacing_rate;
1251                 break;
1252 
1253         case SO_INCOMING_CPU:
1254                 v.val = sk->sk_incoming_cpu;
1255                 break;
1256 
1257         default:
1258                 /* We implement the SO_SNDLOWAT etc to not be settable
1259                  * (1003.1g 7).
1260                  */
1261                 return -ENOPROTOOPT;
1262         }
1263 
1264         if (len > lv)
1265                 len = lv;
1266         if (copy_to_user(optval, &v, len))
1267                 return -EFAULT;
1268 lenout:
1269         if (put_user(len, optlen))
1270                 return -EFAULT;
1271         return 0;
1272 }
1273 
1274 /*
1275  * Initialize an sk_lock.
1276  *
1277  * (We also register the sk_lock with the lock validator.)
1278  */
1279 static inline void sock_lock_init(struct sock *sk)
1280 {
1281         sock_lock_init_class_and_name(sk,
1282                         af_family_slock_key_strings[sk->sk_family],
1283                         af_family_slock_keys + sk->sk_family,
1284                         af_family_key_strings[sk->sk_family],
1285                         af_family_keys + sk->sk_family);
1286 }
1287 
1288 /*
1289  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1290  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1291  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1292  */
1293 static void sock_copy(struct sock *nsk, const struct sock *osk)
1294 {
1295 #ifdef CONFIG_SECURITY_NETWORK
1296         void *sptr = nsk->sk_security;
1297 #endif
1298         memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1299 
1300         memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1301                osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1302 
1303 #ifdef CONFIG_SECURITY_NETWORK
1304         nsk->sk_security = sptr;
1305         security_sk_clone(osk, nsk);
1306 #endif
1307 }
1308 
1309 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1310 {
1311         unsigned long nulls1, nulls2;
1312 
1313         nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1314         nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1315         if (nulls1 > nulls2)
1316                 swap(nulls1, nulls2);
1317 
1318         if (nulls1 != 0)
1319                 memset((char *)sk, 0, nulls1);
1320         memset((char *)sk + nulls1 + sizeof(void *), 0,
1321                nulls2 - nulls1 - sizeof(void *));
1322         memset((char *)sk + nulls2 + sizeof(void *), 0,
1323                size - nulls2 - sizeof(void *));
1324 }
1325 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1326 
1327 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1328                 int family)
1329 {
1330         struct sock *sk;
1331         struct kmem_cache *slab;
1332 
1333         slab = prot->slab;
1334         if (slab != NULL) {
1335                 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1336                 if (!sk)
1337                         return sk;
1338                 if (priority & __GFP_ZERO) {
1339                         if (prot->clear_sk)
1340                                 prot->clear_sk(sk, prot->obj_size);
1341                         else
1342                                 sk_prot_clear_nulls(sk, prot->obj_size);
1343                 }
1344         } else
1345                 sk = kmalloc(prot->obj_size, priority);
1346 
1347         if (sk != NULL) {
1348                 kmemcheck_annotate_bitfield(sk, flags);
1349 
1350                 if (security_sk_alloc(sk, family, priority))
1351                         goto out_free;
1352 
1353                 if (!try_module_get(prot->owner))
1354                         goto out_free_sec;
1355                 sk_tx_queue_clear(sk);
1356                 cgroup_sk_alloc(&sk->sk_cgrp_data);
1357         }
1358 
1359         return sk;
1360 
1361 out_free_sec:
1362         security_sk_free(sk);
1363 out_free:
1364         if (slab != NULL)
1365                 kmem_cache_free(slab, sk);
1366         else
1367                 kfree(sk);
1368         return NULL;
1369 }
1370 
1371 static void sk_prot_free(struct proto *prot, struct sock *sk)
1372 {
1373         struct kmem_cache *slab;
1374         struct module *owner;
1375 
1376         owner = prot->owner;
1377         slab = prot->slab;
1378 
1379         cgroup_sk_free(&sk->sk_cgrp_data);
1380         security_sk_free(sk);
1381         if (slab != NULL)
1382                 kmem_cache_free(slab, sk);
1383         else
1384                 kfree(sk);
1385         module_put(owner);
1386 }
1387 
1388 /**
1389  *      sk_alloc - All socket objects are allocated here
1390  *      @net: the applicable net namespace
1391  *      @family: protocol family
1392  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1393  *      @prot: struct proto associated with this new sock instance
1394  *      @kern: is this to be a kernel socket?
1395  */
1396 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1397                       struct proto *prot, int kern)
1398 {
1399         struct sock *sk;
1400 
1401         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1402         if (sk) {
1403                 sk->sk_family = family;
1404                 /*
1405                  * See comment in struct sock definition to understand
1406                  * why we need sk_prot_creator -acme
1407                  */
1408                 sk->sk_prot = sk->sk_prot_creator = prot;
1409                 sock_lock_init(sk);
1410                 sk->sk_net_refcnt = kern ? 0 : 1;
1411                 if (likely(sk->sk_net_refcnt))
1412                         get_net(net);
1413                 sock_net_set(sk, net);
1414                 atomic_set(&sk->sk_wmem_alloc, 1);
1415 
1416                 sock_update_classid(&sk->sk_cgrp_data);
1417                 sock_update_netprioidx(&sk->sk_cgrp_data);
1418         }
1419 
1420         return sk;
1421 }
1422 EXPORT_SYMBOL(sk_alloc);
1423 
1424 void sk_destruct(struct sock *sk)
1425 {
1426         struct sk_filter *filter;
1427 
1428         if (sk->sk_destruct)
1429                 sk->sk_destruct(sk);
1430 
1431         filter = rcu_dereference_check(sk->sk_filter,
1432                                        atomic_read(&sk->sk_wmem_alloc) == 0);
1433         if (filter) {
1434                 sk_filter_uncharge(sk, filter);
1435                 RCU_INIT_POINTER(sk->sk_filter, NULL);
1436         }
1437         if (rcu_access_pointer(sk->sk_reuseport_cb))
1438                 reuseport_detach_sock(sk);
1439 
1440         sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1441 
1442         if (atomic_read(&sk->sk_omem_alloc))
1443                 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1444                          __func__, atomic_read(&sk->sk_omem_alloc));
1445 
1446         if (sk->sk_peer_cred)
1447                 put_cred(sk->sk_peer_cred);
1448         put_pid(sk->sk_peer_pid);
1449         if (likely(sk->sk_net_refcnt))
1450                 put_net(sock_net(sk));
1451         sk_prot_free(sk->sk_prot_creator, sk);
1452 }
1453 
1454 static void __sk_free(struct sock *sk)
1455 {
1456         if (unlikely(sock_diag_has_destroy_listeners(sk) && sk->sk_net_refcnt))
1457                 sock_diag_broadcast_destroy(sk);
1458         else
1459                 sk_destruct(sk);
1460 }
1461 
1462 void sk_free(struct sock *sk)
1463 {
1464         /*
1465          * We subtract one from sk_wmem_alloc and can know if
1466          * some packets are still in some tx queue.
1467          * If not null, sock_wfree() will call __sk_free(sk) later
1468          */
1469         if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1470                 __sk_free(sk);
1471 }
1472 EXPORT_SYMBOL(sk_free);
1473 
1474 /**
1475  *      sk_clone_lock - clone a socket, and lock its clone
1476  *      @sk: the socket to clone
1477  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1478  *
1479  *      Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1480  */
1481 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1482 {
1483         struct sock *newsk;
1484         bool is_charged = true;
1485 
1486         newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1487         if (newsk != NULL) {
1488                 struct sk_filter *filter;
1489 
1490                 sock_copy(newsk, sk);
1491 
1492                 /* SANITY */
1493                 if (likely(newsk->sk_net_refcnt))
1494                         get_net(sock_net(newsk));
1495                 sk_node_init(&newsk->sk_node);
1496                 sock_lock_init(newsk);
1497                 bh_lock_sock(newsk);
1498                 newsk->sk_backlog.head  = newsk->sk_backlog.tail = NULL;
1499                 newsk->sk_backlog.len = 0;
1500 
1501                 atomic_set(&newsk->sk_rmem_alloc, 0);
1502                 /*
1503                  * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1504                  */
1505                 atomic_set(&newsk->sk_wmem_alloc, 1);
1506                 atomic_set(&newsk->sk_omem_alloc, 0);
1507                 skb_queue_head_init(&newsk->sk_receive_queue);
1508                 skb_queue_head_init(&newsk->sk_write_queue);
1509 
1510                 rwlock_init(&newsk->sk_callback_lock);
1511                 lockdep_set_class_and_name(&newsk->sk_callback_lock,
1512                                 af_callback_keys + newsk->sk_family,
1513                                 af_family_clock_key_strings[newsk->sk_family]);
1514 
1515                 newsk->sk_dst_cache     = NULL;
1516                 newsk->sk_wmem_queued   = 0;
1517                 newsk->sk_forward_alloc = 0;
1518                 newsk->sk_send_head     = NULL;
1519                 newsk->sk_userlocks     = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1520 
1521                 sock_reset_flag(newsk, SOCK_DONE);
1522                 skb_queue_head_init(&newsk->sk_error_queue);
1523 
1524                 filter = rcu_dereference_protected(newsk->sk_filter, 1);
1525                 if (filter != NULL)
1526                         /* though it's an empty new sock, the charging may fail
1527                          * if sysctl_optmem_max was changed between creation of
1528                          * original socket and cloning
1529                          */
1530                         is_charged = sk_filter_charge(newsk, filter);
1531 
1532                 if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1533                         /* It is still raw copy of parent, so invalidate
1534                          * destructor and make plain sk_free() */
1535                         newsk->sk_destruct = NULL;
1536                         bh_unlock_sock(newsk);
1537                         sk_free(newsk);
1538                         newsk = NULL;
1539                         goto out;
1540                 }
1541                 RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1542 
1543                 newsk->sk_err      = 0;
1544                 newsk->sk_priority = 0;
1545                 newsk->sk_incoming_cpu = raw_smp_processor_id();
1546                 atomic64_set(&newsk->sk_cookie, 0);
1547                 /*
1548                  * Before updating sk_refcnt, we must commit prior changes to memory
1549                  * (Documentation/RCU/rculist_nulls.txt for details)
1550                  */
1551                 smp_wmb();
1552                 atomic_set(&newsk->sk_refcnt, 2);
1553 
1554                 /*
1555                  * Increment the counter in the same struct proto as the master
1556                  * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1557                  * is the same as sk->sk_prot->socks, as this field was copied
1558                  * with memcpy).
1559                  *
1560                  * This _changes_ the previous behaviour, where
1561                  * tcp_create_openreq_child always was incrementing the
1562                  * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1563                  * to be taken into account in all callers. -acme
1564                  */
1565                 sk_refcnt_debug_inc(newsk);
1566                 sk_set_socket(newsk, NULL);
1567                 newsk->sk_wq = NULL;
1568 
1569                 if (mem_cgroup_sockets_enabled && sk->sk_memcg)
1570                         sock_update_memcg(newsk);
1571 
1572                 if (newsk->sk_prot->sockets_allocated)
1573                         sk_sockets_allocated_inc(newsk);
1574 
1575                 if (sock_needs_netstamp(sk) &&
1576                     newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1577                         net_enable_timestamp();
1578         }
1579 out:
1580         return newsk;
1581 }
1582 EXPORT_SYMBOL_GPL(sk_clone_lock);
1583 
1584 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1585 {
1586         u32 max_segs = 1;
1587 
1588         sk_dst_set(sk, dst);
1589         sk->sk_route_caps = dst->dev->features;
1590         if (sk->sk_route_caps & NETIF_F_GSO)
1591                 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1592         sk->sk_route_caps &= ~sk->sk_route_nocaps;
1593         if (sk_can_gso(sk)) {
1594                 if (dst->header_len) {
1595                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1596                 } else {
1597                         sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1598                         sk->sk_gso_max_size = dst->dev->gso_max_size;
1599                         max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1600                 }
1601         }
1602         sk->sk_gso_max_segs = max_segs;
1603 }
1604 EXPORT_SYMBOL_GPL(sk_setup_caps);
1605 
1606 /*
1607  *      Simple resource managers for sockets.
1608  */
1609 
1610 
1611 /*
1612  * Write buffer destructor automatically called from kfree_skb.
1613  */
1614 void sock_wfree(struct sk_buff *skb)
1615 {
1616         struct sock *sk = skb->sk;
1617         unsigned int len = skb->truesize;
1618 
1619         if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1620                 /*
1621                  * Keep a reference on sk_wmem_alloc, this will be released
1622                  * after sk_write_space() call
1623                  */
1624                 atomic_sub(len - 1, &sk->sk_wmem_alloc);
1625                 sk->sk_write_space(sk);
1626                 len = 1;
1627         }
1628         /*
1629          * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1630          * could not do because of in-flight packets
1631          */
1632         if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1633                 __sk_free(sk);
1634 }
1635 EXPORT_SYMBOL(sock_wfree);
1636 
1637 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1638 {
1639         skb_orphan(skb);
1640         skb->sk = sk;
1641 #ifdef CONFIG_INET
1642         if (unlikely(!sk_fullsock(sk))) {
1643                 skb->destructor = sock_edemux;
1644                 sock_hold(sk);
1645                 return;
1646         }
1647 #endif
1648         skb->destructor = sock_wfree;
1649         skb_set_hash_from_sk(skb, sk);
1650         /*
1651          * We used to take a refcount on sk, but following operation
1652          * is enough to guarantee sk_free() wont free this sock until
1653          * all in-flight packets are completed
1654          */
1655         atomic_add(skb->truesize, &sk->sk_wmem_alloc);
1656 }
1657 EXPORT_SYMBOL(skb_set_owner_w);
1658 
1659 void skb_orphan_partial(struct sk_buff *skb)
1660 {
1661         /* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1662          * so we do not completely orphan skb, but transfert all
1663          * accounted bytes but one, to avoid unexpected reorders.
1664          */
1665         if (skb->destructor == sock_wfree
1666 #ifdef CONFIG_INET
1667             || skb->destructor == tcp_wfree
1668 #endif
1669                 ) {
1670                 atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1671                 skb->truesize = 1;
1672         } else {
1673                 skb_orphan(skb);
1674         }
1675 }
1676 EXPORT_SYMBOL(skb_orphan_partial);
1677 
1678 /*
1679  * Read buffer destructor automatically called from kfree_skb.
1680  */
1681 void sock_rfree(struct sk_buff *skb)
1682 {
1683         struct sock *sk = skb->sk;
1684         unsigned int len = skb->truesize;
1685 
1686         atomic_sub(len, &sk->sk_rmem_alloc);
1687         sk_mem_uncharge(sk, len);
1688 }
1689 EXPORT_SYMBOL(sock_rfree);
1690 
1691 /*
1692  * Buffer destructor for skbs that are not used directly in read or write
1693  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1694  */
1695 void sock_efree(struct sk_buff *skb)
1696 {
1697         sock_put(skb->sk);
1698 }
1699 EXPORT_SYMBOL(sock_efree);
1700 
1701 kuid_t sock_i_uid(struct sock *sk)
1702 {
1703         kuid_t uid;
1704 
1705         read_lock_bh(&sk->sk_callback_lock);
1706         uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1707         read_unlock_bh(&sk->sk_callback_lock);
1708         return uid;
1709 }
1710 EXPORT_SYMBOL(sock_i_uid);
1711 
1712 unsigned long sock_i_ino(struct sock *sk)
1713 {
1714         unsigned long ino;
1715 
1716         read_lock_bh(&sk->sk_callback_lock);
1717         ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1718         read_unlock_bh(&sk->sk_callback_lock);
1719         return ino;
1720 }
1721 EXPORT_SYMBOL(sock_i_ino);
1722 
1723 /*
1724  * Allocate a skb from the socket's send buffer.
1725  */
1726 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1727                              gfp_t priority)
1728 {
1729         if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1730                 struct sk_buff *skb = alloc_skb(size, priority);
1731                 if (skb) {
1732                         skb_set_owner_w(skb, sk);
1733                         return skb;
1734                 }
1735         }
1736         return NULL;
1737 }
1738 EXPORT_SYMBOL(sock_wmalloc);
1739 
1740 /*
1741  * Allocate a memory block from the socket's option memory buffer.
1742  */
1743 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1744 {
1745         if ((unsigned int)size <= sysctl_optmem_max &&
1746             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1747                 void *mem;
1748                 /* First do the add, to avoid the race if kmalloc
1749                  * might sleep.
1750                  */
1751                 atomic_add(size, &sk->sk_omem_alloc);
1752                 mem = kmalloc(size, priority);
1753                 if (mem)
1754                         return mem;
1755                 atomic_sub(size, &sk->sk_omem_alloc);
1756         }
1757         return NULL;
1758 }
1759 EXPORT_SYMBOL(sock_kmalloc);
1760 
1761 /* Free an option memory block. Note, we actually want the inline
1762  * here as this allows gcc to detect the nullify and fold away the
1763  * condition entirely.
1764  */
1765 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
1766                                   const bool nullify)
1767 {
1768         if (WARN_ON_ONCE(!mem))
1769                 return;
1770         if (nullify)
1771                 kzfree(mem);
1772         else
1773                 kfree(mem);
1774         atomic_sub(size, &sk->sk_omem_alloc);
1775 }
1776 
1777 void sock_kfree_s(struct sock *sk, void *mem, int size)
1778 {
1779         __sock_kfree_s(sk, mem, size, false);
1780 }
1781 EXPORT_SYMBOL(sock_kfree_s);
1782 
1783 void sock_kzfree_s(struct sock *sk, void *mem, int size)
1784 {
1785         __sock_kfree_s(sk, mem, size, true);
1786 }
1787 EXPORT_SYMBOL(sock_kzfree_s);
1788 
1789 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1790    I think, these locks should be removed for datagram sockets.
1791  */
1792 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1793 {
1794         DEFINE_WAIT(wait);
1795 
1796         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1797         for (;;) {
1798                 if (!timeo)
1799                         break;
1800                 if (signal_pending(current))
1801                         break;
1802                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1803                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1804                 if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1805                         break;
1806                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1807                         break;
1808                 if (sk->sk_err)
1809                         break;
1810                 timeo = schedule_timeout(timeo);
1811         }
1812         finish_wait(sk_sleep(sk), &wait);
1813         return timeo;
1814 }
1815 
1816 
1817 /*
1818  *      Generic send/receive buffer handlers
1819  */
1820 
1821 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1822                                      unsigned long data_len, int noblock,
1823                                      int *errcode, int max_page_order)
1824 {
1825         struct sk_buff *skb;
1826         long timeo;
1827         int err;
1828 
1829         timeo = sock_sndtimeo(sk, noblock);
1830         for (;;) {
1831                 err = sock_error(sk);
1832                 if (err != 0)
1833                         goto failure;
1834 
1835                 err = -EPIPE;
1836                 if (sk->sk_shutdown & SEND_SHUTDOWN)
1837                         goto failure;
1838 
1839                 if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
1840                         break;
1841 
1842                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
1843                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1844                 err = -EAGAIN;
1845                 if (!timeo)
1846                         goto failure;
1847                 if (signal_pending(current))
1848                         goto interrupted;
1849                 timeo = sock_wait_for_wmem(sk, timeo);
1850         }
1851         skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
1852                                    errcode, sk->sk_allocation);
1853         if (skb)
1854                 skb_set_owner_w(skb, sk);
1855         return skb;
1856 
1857 interrupted:
1858         err = sock_intr_errno(timeo);
1859 failure:
1860         *errcode = err;
1861         return NULL;
1862 }
1863 EXPORT_SYMBOL(sock_alloc_send_pskb);
1864 
1865 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1866                                     int noblock, int *errcode)
1867 {
1868         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1869 }
1870 EXPORT_SYMBOL(sock_alloc_send_skb);
1871 
1872 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
1873                    struct sockcm_cookie *sockc)
1874 {
1875         struct cmsghdr *cmsg;
1876 
1877         for_each_cmsghdr(cmsg, msg) {
1878                 if (!CMSG_OK(msg, cmsg))
1879                         return -EINVAL;
1880                 if (cmsg->cmsg_level != SOL_SOCKET)
1881                         continue;
1882                 switch (cmsg->cmsg_type) {
1883                 case SO_MARK:
1884                         if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1885                                 return -EPERM;
1886                         if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
1887                                 return -EINVAL;
1888                         sockc->mark = *(u32 *)CMSG_DATA(cmsg);
1889                         break;
1890                 default:
1891                         return -EINVAL;
1892                 }
1893         }
1894         return 0;
1895 }
1896 EXPORT_SYMBOL(sock_cmsg_send);
1897 
1898 /* On 32bit arches, an skb frag is limited to 2^15 */
1899 #define SKB_FRAG_PAGE_ORDER     get_order(32768)
1900 
1901 /**
1902  * skb_page_frag_refill - check that a page_frag contains enough room
1903  * @sz: minimum size of the fragment we want to get
1904  * @pfrag: pointer to page_frag
1905  * @gfp: priority for memory allocation
1906  *
1907  * Note: While this allocator tries to use high order pages, there is
1908  * no guarantee that allocations succeed. Therefore, @sz MUST be
1909  * less or equal than PAGE_SIZE.
1910  */
1911 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
1912 {
1913         if (pfrag->page) {
1914                 if (page_ref_count(pfrag->page) == 1) {
1915                         pfrag->offset = 0;
1916                         return true;
1917                 }
1918                 if (pfrag->offset + sz <= pfrag->size)
1919                         return true;
1920                 put_page(pfrag->page);
1921         }
1922 
1923         pfrag->offset = 0;
1924         if (SKB_FRAG_PAGE_ORDER) {
1925                 /* Avoid direct reclaim but allow kswapd to wake */
1926                 pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
1927                                           __GFP_COMP | __GFP_NOWARN |
1928                                           __GFP_NORETRY,
1929                                           SKB_FRAG_PAGE_ORDER);
1930                 if (likely(pfrag->page)) {
1931                         pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
1932                         return true;
1933                 }
1934         }
1935         pfrag->page = alloc_page(gfp);
1936         if (likely(pfrag->page)) {
1937                 pfrag->size = PAGE_SIZE;
1938                 return true;
1939         }
1940         return false;
1941 }
1942 EXPORT_SYMBOL(skb_page_frag_refill);
1943 
1944 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1945 {
1946         if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1947                 return true;
1948 
1949         sk_enter_memory_pressure(sk);
1950         sk_stream_moderate_sndbuf(sk);
1951         return false;
1952 }
1953 EXPORT_SYMBOL(sk_page_frag_refill);
1954 
1955 static void __lock_sock(struct sock *sk)
1956         __releases(&sk->sk_lock.slock)
1957         __acquires(&sk->sk_lock.slock)
1958 {
1959         DEFINE_WAIT(wait);
1960 
1961         for (;;) {
1962                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1963                                         TASK_UNINTERRUPTIBLE);
1964                 spin_unlock_bh(&sk->sk_lock.slock);
1965                 schedule();
1966                 spin_lock_bh(&sk->sk_lock.slock);
1967                 if (!sock_owned_by_user(sk))
1968                         break;
1969         }
1970         finish_wait(&sk->sk_lock.wq, &wait);
1971 }
1972 
1973 static void __release_sock(struct sock *sk)
1974         __releases(&sk->sk_lock.slock)
1975         __acquires(&sk->sk_lock.slock)
1976 {
1977         struct sk_buff *skb = sk->sk_backlog.head;
1978 
1979         do {
1980                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1981                 bh_unlock_sock(sk);
1982 
1983                 do {
1984                         struct sk_buff *next = skb->next;
1985 
1986                         prefetch(next);
1987                         WARN_ON_ONCE(skb_dst_is_noref(skb));
1988                         skb->next = NULL;
1989                         sk_backlog_rcv(sk, skb);
1990 
1991                         /*
1992                          * We are in process context here with softirqs
1993                          * disabled, use cond_resched_softirq() to preempt.
1994                          * This is safe to do because we've taken the backlog
1995                          * queue private:
1996                          */
1997                         cond_resched_softirq();
1998 
1999                         skb = next;
2000                 } while (skb != NULL);
2001 
2002                 bh_lock_sock(sk);
2003         } while ((skb = sk->sk_backlog.head) != NULL);
2004 
2005         /*
2006          * Doing the zeroing here guarantee we can not loop forever
2007          * while a wild producer attempts to flood us.
2008          */
2009         sk->sk_backlog.len = 0;
2010 }
2011 
2012 /**
2013  * sk_wait_data - wait for data to arrive at sk_receive_queue
2014  * @sk:    sock to wait on
2015  * @timeo: for how long
2016  * @skb:   last skb seen on sk_receive_queue
2017  *
2018  * Now socket state including sk->sk_err is changed only under lock,
2019  * hence we may omit checks after joining wait queue.
2020  * We check receive queue before schedule() only as optimization;
2021  * it is very likely that release_sock() added new data.
2022  */
2023 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2024 {
2025         int rc;
2026         DEFINE_WAIT(wait);
2027 
2028         prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2029         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2030         rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb);
2031         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2032         finish_wait(sk_sleep(sk), &wait);
2033         return rc;
2034 }
2035 EXPORT_SYMBOL(sk_wait_data);
2036 
2037 /**
2038  *      __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2039  *      @sk: socket
2040  *      @size: memory size to allocate
2041  *      @kind: allocation type
2042  *
2043  *      If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2044  *      rmem allocation. This function assumes that protocols which have
2045  *      memory_pressure use sk_wmem_queued as write buffer accounting.
2046  */
2047 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2048 {
2049         struct proto *prot = sk->sk_prot;
2050         int amt = sk_mem_pages(size);
2051         long allocated;
2052 
2053         sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
2054 
2055         allocated = sk_memory_allocated_add(sk, amt);
2056 
2057         if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2058             !mem_cgroup_charge_skmem(sk->sk_memcg, amt))
2059                 goto suppress_allocation;
2060 
2061         /* Under limit. */
2062         if (allocated <= sk_prot_mem_limits(sk, 0)) {
2063                 sk_leave_memory_pressure(sk);
2064                 return 1;
2065         }
2066 
2067         /* Under pressure. */
2068         if (allocated > sk_prot_mem_limits(sk, 1))
2069                 sk_enter_memory_pressure(sk);
2070 
2071         /* Over hard limit. */
2072         if (allocated > sk_prot_mem_limits(sk, 2))
2073                 goto suppress_allocation;
2074 
2075         /* guarantee minimum buffer size under pressure */
2076         if (kind == SK_MEM_RECV) {
2077                 if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2078                         return 1;
2079 
2080         } else { /* SK_MEM_SEND */
2081                 if (sk->sk_type == SOCK_STREAM) {
2082                         if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2083                                 return 1;
2084                 } else if (atomic_read(&sk->sk_wmem_alloc) <
2085                            prot->sysctl_wmem[0])
2086                                 return 1;
2087         }
2088 
2089         if (sk_has_memory_pressure(sk)) {
2090                 int alloc;
2091 
2092                 if (!sk_under_memory_pressure(sk))
2093                         return 1;
2094                 alloc = sk_sockets_allocated_read_positive(sk);
2095                 if (sk_prot_mem_limits(sk, 2) > alloc *
2096                     sk_mem_pages(sk->sk_wmem_queued +
2097                                  atomic_read(&sk->sk_rmem_alloc) +
2098                                  sk->sk_forward_alloc))
2099                         return 1;
2100         }
2101 
2102 suppress_allocation:
2103 
2104         if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2105                 sk_stream_moderate_sndbuf(sk);
2106 
2107                 /* Fail only if socket is _under_ its sndbuf.
2108                  * In this case we cannot block, so that we have to fail.
2109                  */
2110                 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2111                         return 1;
2112         }
2113 
2114         trace_sock_exceed_buf_limit(sk, prot, allocated);
2115 
2116         /* Alas. Undo changes. */
2117         sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2118 
2119         sk_memory_allocated_sub(sk, amt);
2120 
2121         if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2122                 mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2123 
2124         return 0;
2125 }
2126 EXPORT_SYMBOL(__sk_mem_schedule);
2127 
2128 /**
2129  *      __sk_mem_reclaim - reclaim memory_allocated
2130  *      @sk: socket
2131  *      @amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2132  */
2133 void __sk_mem_reclaim(struct sock *sk, int amount)
2134 {
2135         amount >>= SK_MEM_QUANTUM_SHIFT;
2136         sk_memory_allocated_sub(sk, amount);
2137         sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2138 
2139         if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2140                 mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2141 
2142         if (sk_under_memory_pressure(sk) &&
2143             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2144                 sk_leave_memory_pressure(sk);
2145 }
2146 EXPORT_SYMBOL(__sk_mem_reclaim);
2147 
2148 
2149 /*
2150  * Set of default routines for initialising struct proto_ops when
2151  * the protocol does not support a particular function. In certain
2152  * cases where it makes no sense for a protocol to have a "do nothing"
2153  * function, some default processing is provided.
2154  */
2155 
2156 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2157 {
2158         return -EOPNOTSUPP;
2159 }
2160 EXPORT_SYMBOL(sock_no_bind);
2161 
2162 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2163                     int len, int flags)
2164 {
2165         return -EOPNOTSUPP;
2166 }
2167 EXPORT_SYMBOL(sock_no_connect);
2168 
2169 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2170 {
2171         return -EOPNOTSUPP;
2172 }
2173 EXPORT_SYMBOL(sock_no_socketpair);
2174 
2175 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2176 {
2177         return -EOPNOTSUPP;
2178 }
2179 EXPORT_SYMBOL(sock_no_accept);
2180 
2181 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2182                     int *len, int peer)
2183 {
2184         return -EOPNOTSUPP;
2185 }
2186 EXPORT_SYMBOL(sock_no_getname);
2187 
2188 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2189 {
2190         return 0;
2191 }
2192 EXPORT_SYMBOL(sock_no_poll);
2193 
2194 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2195 {
2196         return -EOPNOTSUPP;
2197 }
2198 EXPORT_SYMBOL(sock_no_ioctl);
2199 
2200 int sock_no_listen(struct socket *sock, int backlog)
2201 {
2202         return -EOPNOTSUPP;
2203 }
2204 EXPORT_SYMBOL(sock_no_listen);
2205 
2206 int sock_no_shutdown(struct socket *sock, int how)
2207 {
2208         return -EOPNOTSUPP;
2209 }
2210 EXPORT_SYMBOL(sock_no_shutdown);
2211 
2212 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2213                     char __user *optval, unsigned int optlen)
2214 {
2215         return -EOPNOTSUPP;
2216 }
2217 EXPORT_SYMBOL(sock_no_setsockopt);
2218 
2219 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2220                     char __user *optval, int __user *optlen)
2221 {
2222         return -EOPNOTSUPP;
2223 }
2224 EXPORT_SYMBOL(sock_no_getsockopt);
2225 
2226 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2227 {
2228         return -EOPNOTSUPP;
2229 }
2230 EXPORT_SYMBOL(sock_no_sendmsg);
2231 
2232 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2233                     int flags)
2234 {
2235         return -EOPNOTSUPP;
2236 }
2237 EXPORT_SYMBOL(sock_no_recvmsg);
2238 
2239 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2240 {
2241         /* Mirror missing mmap method error code */
2242         return -ENODEV;
2243 }
2244 EXPORT_SYMBOL(sock_no_mmap);
2245 
2246 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2247 {
2248         ssize_t res;
2249         struct msghdr msg = {.msg_flags = flags};
2250         struct kvec iov;
2251         char *kaddr = kmap(page);
2252         iov.iov_base = kaddr + offset;
2253         iov.iov_len = size;
2254         res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2255         kunmap(page);
2256         return res;
2257 }
2258 EXPORT_SYMBOL(sock_no_sendpage);
2259 
2260 /*
2261  *      Default Socket Callbacks
2262  */
2263 
2264 static void sock_def_wakeup(struct sock *sk)
2265 {
2266         struct socket_wq *wq;
2267 
2268         rcu_read_lock();
2269         wq = rcu_dereference(sk->sk_wq);
2270         if (skwq_has_sleeper(wq))
2271                 wake_up_interruptible_all(&wq->wait);
2272         rcu_read_unlock();
2273 }
2274 
2275 static void sock_def_error_report(struct sock *sk)
2276 {
2277         struct socket_wq *wq;
2278 
2279         rcu_read_lock();
2280         wq = rcu_dereference(sk->sk_wq);
2281         if (skwq_has_sleeper(wq))
2282                 wake_up_interruptible_poll(&wq->wait, POLLERR);
2283         sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2284         rcu_read_unlock();
2285 }
2286 
2287 static void sock_def_readable(struct sock *sk)
2288 {
2289         struct socket_wq *wq;
2290 
2291         rcu_read_lock();
2292         wq = rcu_dereference(sk->sk_wq);
2293         if (skwq_has_sleeper(wq))
2294                 wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2295                                                 POLLRDNORM | POLLRDBAND);
2296         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2297         rcu_read_unlock();
2298 }
2299 
2300 static void sock_def_write_space(struct sock *sk)
2301 {
2302         struct socket_wq *wq;
2303 
2304         rcu_read_lock();
2305 
2306         /* Do not wake up a writer until he can make "significant"
2307          * progress.  --DaveM
2308          */
2309         if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2310                 wq = rcu_dereference(sk->sk_wq);
2311                 if (skwq_has_sleeper(wq))
2312                         wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2313                                                 POLLWRNORM | POLLWRBAND);
2314 
2315                 /* Should agree with poll, otherwise some programs break */
2316                 if (sock_writeable(sk))
2317                         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2318         }
2319 
2320         rcu_read_unlock();
2321 }
2322 
2323 static void sock_def_destruct(struct sock *sk)
2324 {
2325 }
2326 
2327 void sk_send_sigurg(struct sock *sk)
2328 {
2329         if (sk->sk_socket && sk->sk_socket->file)
2330                 if (send_sigurg(&sk->sk_socket->file->f_owner))
2331                         sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2332 }
2333 EXPORT_SYMBOL(sk_send_sigurg);
2334 
2335 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2336                     unsigned long expires)
2337 {
2338         if (!mod_timer(timer, expires))
2339                 sock_hold(sk);
2340 }
2341 EXPORT_SYMBOL(sk_reset_timer);
2342 
2343 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2344 {
2345         if (del_timer(timer))
2346                 __sock_put(sk);
2347 }
2348 EXPORT_SYMBOL(sk_stop_timer);
2349 
2350 void sock_init_data(struct socket *sock, struct sock *sk)
2351 {
2352         skb_queue_head_init(&sk->sk_receive_queue);
2353         skb_queue_head_init(&sk->sk_write_queue);
2354         skb_queue_head_init(&sk->sk_error_queue);
2355 
2356         sk->sk_send_head        =       NULL;
2357 
2358         init_timer(&sk->sk_timer);
2359 
2360         sk->sk_allocation       =       GFP_KERNEL;
2361         sk->sk_rcvbuf           =       sysctl_rmem_default;
2362         sk->sk_sndbuf           =       sysctl_wmem_default;
2363         sk->sk_state            =       TCP_CLOSE;
2364         sk_set_socket(sk, sock);
2365 
2366         sock_set_flag(sk, SOCK_ZAPPED);
2367 
2368         if (sock) {
2369                 sk->sk_type     =       sock->type;
2370                 sk->sk_wq       =       sock->wq;
2371                 sock->sk        =       sk;
2372         } else
2373                 sk->sk_wq       =       NULL;
2374 
2375         rwlock_init(&sk->sk_callback_lock);
2376         lockdep_set_class_and_name(&sk->sk_callback_lock,
2377                         af_callback_keys + sk->sk_family,
2378                         af_family_clock_key_strings[sk->sk_family]);
2379 
2380         sk->sk_state_change     =       sock_def_wakeup;
2381         sk->sk_data_ready       =       sock_def_readable;
2382         sk->sk_write_space      =       sock_def_write_space;
2383         sk->sk_error_report     =       sock_def_error_report;
2384         sk->sk_destruct         =       sock_def_destruct;
2385 
2386         sk->sk_frag.page        =       NULL;
2387         sk->sk_frag.offset      =       0;
2388         sk->sk_peek_off         =       -1;
2389 
2390         sk->sk_peer_pid         =       NULL;
2391         sk->sk_peer_cred        =       NULL;
2392         sk->sk_write_pending    =       0;
2393         sk->sk_rcvlowat         =       1;
2394         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
2395         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
2396 
2397         sk->sk_stamp = ktime_set(-1L, 0);
2398 
2399 #ifdef CONFIG_NET_RX_BUSY_POLL
2400         sk->sk_napi_id          =       0;
2401         sk->sk_ll_usec          =       sysctl_net_busy_read;
2402 #endif
2403 
2404         sk->sk_max_pacing_rate = ~0U;
2405         sk->sk_pacing_rate = ~0U;
2406         sk->sk_incoming_cpu = -1;
2407         /*
2408          * Before updating sk_refcnt, we must commit prior changes to memory
2409          * (Documentation/RCU/rculist_nulls.txt for details)
2410          */
2411         smp_wmb();
2412         atomic_set(&sk->sk_refcnt, 1);
2413         atomic_set(&sk->sk_drops, 0);
2414 }
2415 EXPORT_SYMBOL(sock_init_data);
2416 
2417 void lock_sock_nested(struct sock *sk, int subclass)
2418 {
2419         might_sleep();
2420         spin_lock_bh(&sk->sk_lock.slock);
2421         if (sk->sk_lock.owned)
2422                 __lock_sock(sk);
2423         sk->sk_lock.owned = 1;
2424         spin_unlock(&sk->sk_lock.slock);
2425         /*
2426          * The sk_lock has mutex_lock() semantics here:
2427          */
2428         mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2429         local_bh_enable();
2430 }
2431 EXPORT_SYMBOL(lock_sock_nested);
2432 
2433 void release_sock(struct sock *sk)
2434 {
2435         /*
2436          * The sk_lock has mutex_unlock() semantics:
2437          */
2438         mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2439 
2440         spin_lock_bh(&sk->sk_lock.slock);
2441         if (sk->sk_backlog.tail)
2442                 __release_sock(sk);
2443 
2444         /* Warning : release_cb() might need to release sk ownership,
2445          * ie call sock_release_ownership(sk) before us.
2446          */
2447         if (sk->sk_prot->release_cb)
2448                 sk->sk_prot->release_cb(sk);
2449 
2450         sock_release_ownership(sk);
2451         if (waitqueue_active(&sk->sk_lock.wq))
2452                 wake_up(&sk->sk_lock.wq);
2453         spin_unlock_bh(&sk->sk_lock.slock);
2454 }
2455 EXPORT_SYMBOL(release_sock);
2456 
2457 /**
2458  * lock_sock_fast - fast version of lock_sock
2459  * @sk: socket
2460  *
2461  * This version should be used for very small section, where process wont block
2462  * return false if fast path is taken
2463  *   sk_lock.slock locked, owned = 0, BH disabled
2464  * return true if slow path is taken
2465  *   sk_lock.slock unlocked, owned = 1, BH enabled
2466  */
2467 bool lock_sock_fast(struct sock *sk)
2468 {
2469         might_sleep();
2470         spin_lock_bh(&sk->sk_lock.slock);
2471 
2472         if (!sk->sk_lock.owned)
2473                 /*
2474                  * Note : We must disable BH
2475                  */
2476                 return false;
2477 
2478         __lock_sock(sk);
2479         sk->sk_lock.owned = 1;
2480         spin_unlock(&sk->sk_lock.slock);
2481         /*
2482          * The sk_lock has mutex_lock() semantics here:
2483          */
2484         mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2485         local_bh_enable();
2486         return true;
2487 }
2488 EXPORT_SYMBOL(lock_sock_fast);
2489 
2490 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2491 {
2492         struct timeval tv;
2493         if (!sock_flag(sk, SOCK_TIMESTAMP))
2494                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2495         tv = ktime_to_timeval(sk->sk_stamp);
2496         if (tv.tv_sec == -1)
2497                 return -ENOENT;
2498         if (tv.tv_sec == 0) {
2499                 sk->sk_stamp = ktime_get_real();
2500                 tv = ktime_to_timeval(sk->sk_stamp);
2501         }
2502         return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2503 }
2504 EXPORT_SYMBOL(sock_get_timestamp);
2505 
2506 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2507 {
2508         struct timespec ts;
2509         if (!sock_flag(sk, SOCK_TIMESTAMP))
2510                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2511         ts = ktime_to_timespec(sk->sk_stamp);
2512         if (ts.tv_sec == -1)
2513                 return -ENOENT;
2514         if (ts.tv_sec == 0) {
2515                 sk->sk_stamp = ktime_get_real();
2516                 ts = ktime_to_timespec(sk->sk_stamp);
2517         }
2518         return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2519 }
2520 EXPORT_SYMBOL(sock_get_timestampns);
2521 
2522 void sock_enable_timestamp(struct sock *sk, int flag)
2523 {
2524         if (!sock_flag(sk, flag)) {
2525                 unsigned long previous_flags = sk->sk_flags;
2526 
2527                 sock_set_flag(sk, flag);
2528                 /*
2529                  * we just set one of the two flags which require net
2530                  * time stamping, but time stamping might have been on
2531                  * already because of the other one
2532                  */
2533                 if (sock_needs_netstamp(sk) &&
2534                     !(previous_flags & SK_FLAGS_TIMESTAMP))
2535                         net_enable_timestamp();
2536         }
2537 }
2538 
2539 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2540                        int level, int type)
2541 {
2542         struct sock_exterr_skb *serr;
2543         struct sk_buff *skb;
2544         int copied, err;
2545 
2546         err = -EAGAIN;
2547         skb = sock_dequeue_err_skb(sk);
2548         if (skb == NULL)
2549                 goto out;
2550 
2551         copied = skb->len;
2552         if (copied > len) {
2553                 msg->msg_flags |= MSG_TRUNC;
2554                 copied = len;
2555         }
2556         err = skb_copy_datagram_msg(skb, 0, msg, copied);
2557         if (err)
2558                 goto out_free_skb;
2559 
2560         sock_recv_timestamp(msg, sk, skb);
2561 
2562         serr = SKB_EXT_ERR(skb);
2563         put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2564 
2565         msg->msg_flags |= MSG_ERRQUEUE;
2566         err = copied;
2567 
2568 out_free_skb:
2569         kfree_skb(skb);
2570 out:
2571         return err;
2572 }
2573 EXPORT_SYMBOL(sock_recv_errqueue);
2574 
2575 /*
2576  *      Get a socket option on an socket.
2577  *
2578  *      FIX: POSIX 1003.1g is very ambiguous here. It states that
2579  *      asynchronous errors should be reported by getsockopt. We assume
2580  *      this means if you specify SO_ERROR (otherwise whats the point of it).
2581  */
2582 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2583                            char __user *optval, int __user *optlen)
2584 {
2585         struct sock *sk = sock->sk;
2586 
2587         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2588 }
2589 EXPORT_SYMBOL(sock_common_getsockopt);
2590 
2591 #ifdef CONFIG_COMPAT
2592 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2593                                   char __user *optval, int __user *optlen)
2594 {
2595         struct sock *sk = sock->sk;
2596 
2597         if (sk->sk_prot->compat_getsockopt != NULL)
2598                 return sk->sk_prot->compat_getsockopt(sk, level, optname,
2599                                                       optval, optlen);
2600         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2601 }
2602 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2603 #endif
2604 
2605 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
2606                         int flags)
2607 {
2608         struct sock *sk = sock->sk;
2609         int addr_len = 0;
2610         int err;
2611 
2612         err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
2613                                    flags & ~MSG_DONTWAIT, &addr_len);
2614         if (err >= 0)
2615                 msg->msg_namelen = addr_len;
2616         return err;
2617 }
2618 EXPORT_SYMBOL(sock_common_recvmsg);
2619 
2620 /*
2621  *      Set socket options on an inet socket.
2622  */
2623 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2624                            char __user *optval, unsigned int optlen)
2625 {
2626         struct sock *sk = sock->sk;
2627 
2628         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2629 }
2630 EXPORT_SYMBOL(sock_common_setsockopt);
2631 
2632 #ifdef CONFIG_COMPAT
2633 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2634                                   char __user *optval, unsigned int optlen)
2635 {
2636         struct sock *sk = sock->sk;
2637 
2638         if (sk->sk_prot->compat_setsockopt != NULL)
2639                 return sk->sk_prot->compat_setsockopt(sk, level, optname,
2640                                                       optval, optlen);
2641         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2642 }
2643 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2644 #endif
2645 
2646 void sk_common_release(struct sock *sk)
2647 {
2648         if (sk->sk_prot->destroy)
2649                 sk->sk_prot->destroy(sk);
2650 
2651         /*
2652          * Observation: when sock_common_release is called, processes have
2653          * no access to socket. But net still has.
2654          * Step one, detach it from networking:
2655          *
2656          * A. Remove from hash tables.
2657          */
2658 
2659         sk->sk_prot->unhash(sk);
2660 
2661         /*
2662          * In this point socket cannot receive new packets, but it is possible
2663          * that some packets are in flight because some CPU runs receiver and
2664          * did hash table lookup before we unhashed socket. They will achieve
2665          * receive queue and will be purged by socket destructor.
2666          *
2667          * Also we still have packets pending on receive queue and probably,
2668          * our own packets waiting in device queues. sock_destroy will drain
2669          * receive queue, but transmitted packets will delay socket destruction
2670          * until the last reference will be released.
2671          */
2672 
2673         sock_orphan(sk);
2674 
2675         xfrm_sk_free_policy(sk);
2676 
2677         sk_refcnt_debug_release(sk);
2678 
2679         if (sk->sk_frag.page) {
2680                 put_page(sk->sk_frag.page);
2681                 sk->sk_frag.page = NULL;
2682         }
2683 
2684         sock_put(sk);
2685 }
2686 EXPORT_SYMBOL(sk_common_release);
2687 
2688 #ifdef CONFIG_PROC_FS
2689 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
2690 struct prot_inuse {
2691         int val[PROTO_INUSE_NR];
2692 };
2693 
2694 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2695 
2696 #ifdef CONFIG_NET_NS
2697 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2698 {
2699         __this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2700 }
2701 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2702 
2703 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2704 {
2705         int cpu, idx = prot->inuse_idx;
2706         int res = 0;
2707 
2708         for_each_possible_cpu(cpu)
2709                 res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2710 
2711         return res >= 0 ? res : 0;
2712 }
2713 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2714 
2715 static int __net_init sock_inuse_init_net(struct net *net)
2716 {
2717         net->core.inuse = alloc_percpu(struct prot_inuse);
2718         return net->core.inuse ? 0 : -ENOMEM;
2719 }
2720 
2721 static void __net_exit sock_inuse_exit_net(struct net *net)
2722 {
2723         free_percpu(net->core.inuse);
2724 }
2725 
2726 static struct pernet_operations net_inuse_ops = {
2727         .init = sock_inuse_init_net,
2728         .exit = sock_inuse_exit_net,
2729 };
2730 
2731 static __init int net_inuse_init(void)
2732 {
2733         if (register_pernet_subsys(&net_inuse_ops))
2734                 panic("Cannot initialize net inuse counters");
2735 
2736         return 0;
2737 }
2738 
2739 core_initcall(net_inuse_init);
2740 #else
2741 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2742 
2743 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2744 {
2745         __this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2746 }
2747 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2748 
2749 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2750 {
2751         int cpu, idx = prot->inuse_idx;
2752         int res = 0;
2753 
2754         for_each_possible_cpu(cpu)
2755                 res += per_cpu(prot_inuse, cpu).val[idx];
2756 
2757         return res >= 0 ? res : 0;
2758 }
2759 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2760 #endif
2761 
2762 static void assign_proto_idx(struct proto *prot)
2763 {
2764         prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2765 
2766         if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2767                 pr_err("PROTO_INUSE_NR exhausted\n");
2768                 return;
2769         }
2770 
2771         set_bit(prot->inuse_idx, proto_inuse_idx);
2772 }
2773 
2774 static void release_proto_idx(struct proto *prot)
2775 {
2776         if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2777                 clear_bit(prot->inuse_idx, proto_inuse_idx);
2778 }
2779 #else
2780 static inline void assign_proto_idx(struct proto *prot)
2781 {
2782 }
2783 
2784 static inline void release_proto_idx(struct proto *prot)
2785 {
2786 }
2787 #endif
2788 
2789 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
2790 {
2791         if (!rsk_prot)
2792                 return;
2793         kfree(rsk_prot->slab_name);
2794         rsk_prot->slab_name = NULL;
2795         kmem_cache_destroy(rsk_prot->slab);
2796         rsk_prot->slab = NULL;
2797 }
2798 
2799 static int req_prot_init(const struct proto *prot)
2800 {
2801         struct request_sock_ops *rsk_prot = prot->rsk_prot;
2802 
2803         if (!rsk_prot)
2804                 return 0;
2805 
2806         rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
2807                                         prot->name);
2808         if (!rsk_prot->slab_name)
2809                 return -ENOMEM;
2810 
2811         rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
2812                                            rsk_prot->obj_size, 0,
2813                                            prot->slab_flags, NULL);
2814 
2815         if (!rsk_prot->slab) {
2816                 pr_crit("%s: Can't create request sock SLAB cache!\n",
2817                         prot->name);
2818                 return -ENOMEM;
2819         }
2820         return 0;
2821 }
2822 
2823 int proto_register(struct proto *prot, int alloc_slab)
2824 {
2825         if (alloc_slab) {
2826                 prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2827                                         SLAB_HWCACHE_ALIGN | prot->slab_flags,
2828                                         NULL);
2829 
2830                 if (prot->slab == NULL) {
2831                         pr_crit("%s: Can't create sock SLAB cache!\n",
2832                                 prot->name);
2833                         goto out;
2834                 }
2835 
2836                 if (req_prot_init(prot))
2837                         goto out_free_request_sock_slab;
2838 
2839                 if (prot->twsk_prot != NULL) {
2840                         prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2841 
2842                         if (prot->twsk_prot->twsk_slab_name == NULL)
2843                                 goto out_free_request_sock_slab;
2844 
2845                         prot->twsk_prot->twsk_slab =
2846                                 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2847                                                   prot->twsk_prot->twsk_obj_size,
2848                                                   0,
2849                                                   prot->slab_flags,
2850                                                   NULL);
2851                         if (prot->twsk_prot->twsk_slab == NULL)
2852                                 goto out_free_timewait_sock_slab_name;
2853                 }
2854         }
2855 
2856         mutex_lock(&proto_list_mutex);
2857         list_add(&prot->node, &proto_list);
2858         assign_proto_idx(prot);
2859         mutex_unlock(&proto_list_mutex);
2860         return 0;
2861 
2862 out_free_timewait_sock_slab_name:
2863         kfree(prot->twsk_prot->twsk_slab_name);
2864 out_free_request_sock_slab:
2865         req_prot_cleanup(prot->rsk_prot);
2866 
2867         kmem_cache_destroy(prot->slab);
2868         prot->slab = NULL;
2869 out:
2870         return -ENOBUFS;
2871 }
2872 EXPORT_SYMBOL(proto_register);
2873 
2874 void proto_unregister(struct proto *prot)
2875 {
2876         mutex_lock(&proto_list_mutex);
2877         release_proto_idx(prot);
2878         list_del(&prot->node);
2879         mutex_unlock(&proto_list_mutex);
2880 
2881         kmem_cache_destroy(prot->slab);
2882         prot->slab = NULL;
2883 
2884         req_prot_cleanup(prot->rsk_prot);
2885 
2886         if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2887                 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2888                 kfree(prot->twsk_prot->twsk_slab_name);
2889                 prot->twsk_prot->twsk_slab = NULL;
2890         }
2891 }
2892 EXPORT_SYMBOL(proto_unregister);
2893 
2894 #ifdef CONFIG_PROC_FS
2895 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2896         __acquires(proto_list_mutex)
2897 {
2898         mutex_lock(&proto_list_mutex);
2899         return seq_list_start_head(&proto_list, *pos);
2900 }
2901 
2902 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2903 {
2904         return seq_list_next(v, &proto_list, pos);
2905 }
2906 
2907 static void proto_seq_stop(struct seq_file *seq, void *v)
2908         __releases(proto_list_mutex)
2909 {
2910         mutex_unlock(&proto_list_mutex);
2911 }
2912 
2913 static char proto_method_implemented(const void *method)
2914 {
2915         return method == NULL ? 'n' : 'y';
2916 }
2917 static long sock_prot_memory_allocated(struct proto *proto)
2918 {
2919         return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2920 }
2921 
2922 static char *sock_prot_memory_pressure(struct proto *proto)
2923 {
2924         return proto->memory_pressure != NULL ?
2925         proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2926 }
2927 
2928 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2929 {
2930 
2931         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2932                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2933                    proto->name,
2934                    proto->obj_size,
2935                    sock_prot_inuse_get(seq_file_net(seq), proto),
2936                    sock_prot_memory_allocated(proto),
2937                    sock_prot_memory_pressure(proto),
2938                    proto->max_header,
2939                    proto->slab == NULL ? "no" : "yes",
2940                    module_name(proto->owner),
2941                    proto_method_implemented(proto->close),
2942                    proto_method_implemented(proto->connect),
2943                    proto_method_implemented(proto->disconnect),
2944                    proto_method_implemented(proto->accept),
2945                    proto_method_implemented(proto->ioctl),
2946                    proto_method_implemented(proto->init),
2947                    proto_method_implemented(proto->destroy),
2948                    proto_method_implemented(proto->shutdown),
2949                    proto_method_implemented(proto->setsockopt),
2950                    proto_method_implemented(proto->getsockopt),
2951                    proto_method_implemented(proto->sendmsg),
2952                    proto_method_implemented(proto->recvmsg),
2953                    proto_method_implemented(proto->sendpage),
2954                    proto_method_implemented(proto->bind),
2955                    proto_method_implemented(proto->backlog_rcv),
2956                    proto_method_implemented(proto->hash),
2957                    proto_method_implemented(proto->unhash),
2958                    proto_method_implemented(proto->get_port),
2959                    proto_method_implemented(proto->enter_memory_pressure));
2960 }
2961 
2962 static int proto_seq_show(struct seq_file *seq, void *v)
2963 {
2964         if (v == &proto_list)
2965                 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2966                            "protocol",
2967                            "size",
2968                            "sockets",
2969                            "memory",
2970                            "press",
2971                            "maxhdr",
2972                            "slab",
2973                            "module",
2974                            "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2975         else
2976                 proto_seq_printf(seq, list_entry(v, struct proto, node));
2977         return 0;
2978 }
2979 
2980 static const struct seq_operations proto_seq_ops = {
2981         .start  = proto_seq_start,
2982         .next   = proto_seq_next,
2983         .stop   = proto_seq_stop,
2984         .show   = proto_seq_show,
2985 };
2986 
2987 static int proto_seq_open(struct inode *inode, struct file *file)
2988 {
2989         return seq_open_net(inode, file, &proto_seq_ops,
2990                             sizeof(struct seq_net_private));
2991 }
2992 
2993 static const struct file_operations proto_seq_fops = {
2994         .owner          = THIS_MODULE,
2995         .open           = proto_seq_open,
2996         .read           = seq_read,
2997         .llseek         = seq_lseek,
2998         .release        = seq_release_net,
2999 };
3000 
3001 static __net_init int proto_init_net(struct net *net)
3002 {
3003         if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
3004                 return -ENOMEM;
3005 
3006         return 0;
3007 }
3008 
3009 static __net_exit void proto_exit_net(struct net *net)
3010 {
3011         remove_proc_entry("protocols", net->proc_net);
3012 }
3013 
3014 
3015 static __net_initdata struct pernet_operations proto_net_ops = {
3016         .init = proto_init_net,
3017         .exit = proto_exit_net,
3018 };
3019 
3020 static int __init proto_init(void)
3021 {
3022         return register_pernet_subsys(&proto_net_ops);
3023 }
3024 
3025 subsys_initcall(proto_init);
3026 
3027 #endif /* PROC_FS */
3028 

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