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TOMOYO Linux Cross Reference
Linux/net/core/sock.c

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  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/sched/mm.h>
106 #include <linux/timer.h>
107 #include <linux/string.h>
108 #include <linux/sockios.h>
109 #include <linux/net.h>
110 #include <linux/mm.h>
111 #include <linux/slab.h>
112 #include <linux/interrupt.h>
113 #include <linux/poll.h>
114 #include <linux/tcp.h>
115 #include <linux/init.h>
116 #include <linux/highmem.h>
117 #include <linux/user_namespace.h>
118 #include <linux/static_key.h>
119 #include <linux/memcontrol.h>
120 #include <linux/prefetch.h>
121 
122 #include <linux/uaccess.h>
123 
124 #include <linux/netdevice.h>
125 #include <net/protocol.h>
126 #include <linux/skbuff.h>
127 #include <net/net_namespace.h>
128 #include <net/request_sock.h>
129 #include <net/sock.h>
130 #include <linux/net_tstamp.h>
131 #include <net/xfrm.h>
132 #include <linux/ipsec.h>
133 #include <net/cls_cgroup.h>
134 #include <net/netprio_cgroup.h>
135 #include <linux/sock_diag.h>
136 
137 #include <linux/filter.h>
138 #include <net/sock_reuseport.h>
139 
140 #include <trace/events/sock.h>
141 
142 #include <net/tcp.h>
143 #include <net/busy_poll.h>
144 
145 static DEFINE_MUTEX(proto_list_mutex);
146 static LIST_HEAD(proto_list);
147 
148 static void sock_inuse_add(struct net *net, int val);
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 and separate keys for internal and
201  * userspace sockets.
202  */
203 static struct lock_class_key af_family_keys[AF_MAX];
204 static struct lock_class_key af_family_kern_keys[AF_MAX];
205 static struct lock_class_key af_family_slock_keys[AF_MAX];
206 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
207 
208 /*
209  * Make lock validator output more readable. (we pre-construct these
210  * strings build-time, so that runtime initialization of socket
211  * locks is fast):
212  */
213 
214 #define _sock_locks(x)                                            \
215   x "AF_UNSPEC",        x "AF_UNIX"     ,       x "AF_INET"     , \
216   x "AF_AX25"  ,        x "AF_IPX"      ,       x "AF_APPLETALK", \
217   x "AF_NETROM",        x "AF_BRIDGE"   ,       x "AF_ATMPVC"   , \
218   x "AF_X25"   ,        x "AF_INET6"    ,       x "AF_ROSE"     , \
219   x "AF_DECnet",        x "AF_NETBEUI"  ,       x "AF_SECURITY" , \
220   x "AF_KEY"   ,        x "AF_NETLINK"  ,       x "AF_PACKET"   , \
221   x "AF_ASH"   ,        x "AF_ECONET"   ,       x "AF_ATMSVC"   , \
222   x "AF_RDS"   ,        x "AF_SNA"      ,       x "AF_IRDA"     , \
223   x "AF_PPPOX" ,        x "AF_WANPIPE"  ,       x "AF_LLC"      , \
224   x "27"       ,        x "28"          ,       x "AF_CAN"      , \
225   x "AF_TIPC"  ,        x "AF_BLUETOOTH",       x "IUCV"        , \
226   x "AF_RXRPC" ,        x "AF_ISDN"     ,       x "AF_PHONET"   , \
227   x "AF_IEEE802154",    x "AF_CAIF"     ,       x "AF_ALG"      , \
228   x "AF_NFC"   ,        x "AF_VSOCK"    ,       x "AF_KCM"      , \
229   x "AF_QIPCRTR",       x "AF_SMC"      ,       x "AF_MAX"
230 
231 static const char *const af_family_key_strings[AF_MAX+1] = {
232         _sock_locks("sk_lock-")
233 };
234 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
235         _sock_locks("slock-")
236 };
237 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
238         _sock_locks("clock-")
239 };
240 
241 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
242         _sock_locks("k-sk_lock-")
243 };
244 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
245         _sock_locks("k-slock-")
246 };
247 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
248         _sock_locks("k-clock-")
249 };
250 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
251   "rlock-AF_UNSPEC", "rlock-AF_UNIX"     , "rlock-AF_INET"     ,
252   "rlock-AF_AX25"  , "rlock-AF_IPX"      , "rlock-AF_APPLETALK",
253   "rlock-AF_NETROM", "rlock-AF_BRIDGE"   , "rlock-AF_ATMPVC"   ,
254   "rlock-AF_X25"   , "rlock-AF_INET6"    , "rlock-AF_ROSE"     ,
255   "rlock-AF_DECnet", "rlock-AF_NETBEUI"  , "rlock-AF_SECURITY" ,
256   "rlock-AF_KEY"   , "rlock-AF_NETLINK"  , "rlock-AF_PACKET"   ,
257   "rlock-AF_ASH"   , "rlock-AF_ECONET"   , "rlock-AF_ATMSVC"   ,
258   "rlock-AF_RDS"   , "rlock-AF_SNA"      , "rlock-AF_IRDA"     ,
259   "rlock-AF_PPPOX" , "rlock-AF_WANPIPE"  , "rlock-AF_LLC"      ,
260   "rlock-27"       , "rlock-28"          , "rlock-AF_CAN"      ,
261   "rlock-AF_TIPC"  , "rlock-AF_BLUETOOTH", "rlock-AF_IUCV"     ,
262   "rlock-AF_RXRPC" , "rlock-AF_ISDN"     , "rlock-AF_PHONET"   ,
263   "rlock-AF_IEEE802154", "rlock-AF_CAIF" , "rlock-AF_ALG"      ,
264   "rlock-AF_NFC"   , "rlock-AF_VSOCK"    , "rlock-AF_KCM"      ,
265   "rlock-AF_QIPCRTR", "rlock-AF_SMC"     , "rlock-AF_MAX"
266 };
267 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
268   "wlock-AF_UNSPEC", "wlock-AF_UNIX"     , "wlock-AF_INET"     ,
269   "wlock-AF_AX25"  , "wlock-AF_IPX"      , "wlock-AF_APPLETALK",
270   "wlock-AF_NETROM", "wlock-AF_BRIDGE"   , "wlock-AF_ATMPVC"   ,
271   "wlock-AF_X25"   , "wlock-AF_INET6"    , "wlock-AF_ROSE"     ,
272   "wlock-AF_DECnet", "wlock-AF_NETBEUI"  , "wlock-AF_SECURITY" ,
273   "wlock-AF_KEY"   , "wlock-AF_NETLINK"  , "wlock-AF_PACKET"   ,
274   "wlock-AF_ASH"   , "wlock-AF_ECONET"   , "wlock-AF_ATMSVC"   ,
275   "wlock-AF_RDS"   , "wlock-AF_SNA"      , "wlock-AF_IRDA"     ,
276   "wlock-AF_PPPOX" , "wlock-AF_WANPIPE"  , "wlock-AF_LLC"      ,
277   "wlock-27"       , "wlock-28"          , "wlock-AF_CAN"      ,
278   "wlock-AF_TIPC"  , "wlock-AF_BLUETOOTH", "wlock-AF_IUCV"     ,
279   "wlock-AF_RXRPC" , "wlock-AF_ISDN"     , "wlock-AF_PHONET"   ,
280   "wlock-AF_IEEE802154", "wlock-AF_CAIF" , "wlock-AF_ALG"      ,
281   "wlock-AF_NFC"   , "wlock-AF_VSOCK"    , "wlock-AF_KCM"      ,
282   "wlock-AF_QIPCRTR", "wlock-AF_SMC"     , "wlock-AF_MAX"
283 };
284 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
285   "elock-AF_UNSPEC", "elock-AF_UNIX"     , "elock-AF_INET"     ,
286   "elock-AF_AX25"  , "elock-AF_IPX"      , "elock-AF_APPLETALK",
287   "elock-AF_NETROM", "elock-AF_BRIDGE"   , "elock-AF_ATMPVC"   ,
288   "elock-AF_X25"   , "elock-AF_INET6"    , "elock-AF_ROSE"     ,
289   "elock-AF_DECnet", "elock-AF_NETBEUI"  , "elock-AF_SECURITY" ,
290   "elock-AF_KEY"   , "elock-AF_NETLINK"  , "elock-AF_PACKET"   ,
291   "elock-AF_ASH"   , "elock-AF_ECONET"   , "elock-AF_ATMSVC"   ,
292   "elock-AF_RDS"   , "elock-AF_SNA"      , "elock-AF_IRDA"     ,
293   "elock-AF_PPPOX" , "elock-AF_WANPIPE"  , "elock-AF_LLC"      ,
294   "elock-27"       , "elock-28"          , "elock-AF_CAN"      ,
295   "elock-AF_TIPC"  , "elock-AF_BLUETOOTH", "elock-AF_IUCV"     ,
296   "elock-AF_RXRPC" , "elock-AF_ISDN"     , "elock-AF_PHONET"   ,
297   "elock-AF_IEEE802154", "elock-AF_CAIF" , "elock-AF_ALG"      ,
298   "elock-AF_NFC"   , "elock-AF_VSOCK"    , "elock-AF_KCM"      ,
299   "elock-AF_QIPCRTR", "elock-AF_SMC"     , "elock-AF_MAX"
300 };
301 
302 /*
303  * sk_callback_lock and sk queues locking rules are per-address-family,
304  * so split the lock classes by using a per-AF key:
305  */
306 static struct lock_class_key af_callback_keys[AF_MAX];
307 static struct lock_class_key af_rlock_keys[AF_MAX];
308 static struct lock_class_key af_wlock_keys[AF_MAX];
309 static struct lock_class_key af_elock_keys[AF_MAX];
310 static struct lock_class_key af_kern_callback_keys[AF_MAX];
311 
312 /* Run time adjustable parameters. */
313 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
314 EXPORT_SYMBOL(sysctl_wmem_max);
315 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
316 EXPORT_SYMBOL(sysctl_rmem_max);
317 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
318 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
319 
320 /* Maximal space eaten by iovec or ancillary data plus some space */
321 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
322 EXPORT_SYMBOL(sysctl_optmem_max);
323 
324 int sysctl_tstamp_allow_data __read_mostly = 1;
325 
326 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
327 EXPORT_SYMBOL_GPL(memalloc_socks);
328 
329 /**
330  * sk_set_memalloc - sets %SOCK_MEMALLOC
331  * @sk: socket to set it on
332  *
333  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
334  * It's the responsibility of the admin to adjust min_free_kbytes
335  * to meet the requirements
336  */
337 void sk_set_memalloc(struct sock *sk)
338 {
339         sock_set_flag(sk, SOCK_MEMALLOC);
340         sk->sk_allocation |= __GFP_MEMALLOC;
341         static_key_slow_inc(&memalloc_socks);
342 }
343 EXPORT_SYMBOL_GPL(sk_set_memalloc);
344 
345 void sk_clear_memalloc(struct sock *sk)
346 {
347         sock_reset_flag(sk, SOCK_MEMALLOC);
348         sk->sk_allocation &= ~__GFP_MEMALLOC;
349         static_key_slow_dec(&memalloc_socks);
350 
351         /*
352          * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
353          * progress of swapping. SOCK_MEMALLOC may be cleared while
354          * it has rmem allocations due to the last swapfile being deactivated
355          * but there is a risk that the socket is unusable due to exceeding
356          * the rmem limits. Reclaim the reserves and obey rmem limits again.
357          */
358         sk_mem_reclaim(sk);
359 }
360 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
361 
362 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
363 {
364         int ret;
365         unsigned int noreclaim_flag;
366 
367         /* these should have been dropped before queueing */
368         BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
369 
370         noreclaim_flag = memalloc_noreclaim_save();
371         ret = sk->sk_backlog_rcv(sk, skb);
372         memalloc_noreclaim_restore(noreclaim_flag);
373 
374         return ret;
375 }
376 EXPORT_SYMBOL(__sk_backlog_rcv);
377 
378 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
379 {
380         struct timeval tv;
381 
382         if (optlen < sizeof(tv))
383                 return -EINVAL;
384         if (copy_from_user(&tv, optval, sizeof(tv)))
385                 return -EFAULT;
386         if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
387                 return -EDOM;
388 
389         if (tv.tv_sec < 0) {
390                 static int warned __read_mostly;
391 
392                 *timeo_p = 0;
393                 if (warned < 10 && net_ratelimit()) {
394                         warned++;
395                         pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
396                                 __func__, current->comm, task_pid_nr(current));
397                 }
398                 return 0;
399         }
400         *timeo_p = MAX_SCHEDULE_TIMEOUT;
401         if (tv.tv_sec == 0 && tv.tv_usec == 0)
402                 return 0;
403         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
404                 *timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP(tv.tv_usec, USEC_PER_SEC / HZ);
405         return 0;
406 }
407 
408 static void sock_warn_obsolete_bsdism(const char *name)
409 {
410         static int warned;
411         static char warncomm[TASK_COMM_LEN];
412         if (strcmp(warncomm, current->comm) && warned < 5) {
413                 strcpy(warncomm,  current->comm);
414                 pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
415                         warncomm, name);
416                 warned++;
417         }
418 }
419 
420 static bool sock_needs_netstamp(const struct sock *sk)
421 {
422         switch (sk->sk_family) {
423         case AF_UNSPEC:
424         case AF_UNIX:
425                 return false;
426         default:
427                 return true;
428         }
429 }
430 
431 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
432 {
433         if (sk->sk_flags & flags) {
434                 sk->sk_flags &= ~flags;
435                 if (sock_needs_netstamp(sk) &&
436                     !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
437                         net_disable_timestamp();
438         }
439 }
440 
441 
442 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
443 {
444         unsigned long flags;
445         struct sk_buff_head *list = &sk->sk_receive_queue;
446 
447         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
448                 atomic_inc(&sk->sk_drops);
449                 trace_sock_rcvqueue_full(sk, skb);
450                 return -ENOMEM;
451         }
452 
453         if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
454                 atomic_inc(&sk->sk_drops);
455                 return -ENOBUFS;
456         }
457 
458         skb->dev = NULL;
459         skb_set_owner_r(skb, sk);
460 
461         /* we escape from rcu protected region, make sure we dont leak
462          * a norefcounted dst
463          */
464         skb_dst_force(skb);
465 
466         spin_lock_irqsave(&list->lock, flags);
467         sock_skb_set_dropcount(sk, skb);
468         __skb_queue_tail(list, skb);
469         spin_unlock_irqrestore(&list->lock, flags);
470 
471         if (!sock_flag(sk, SOCK_DEAD))
472                 sk->sk_data_ready(sk);
473         return 0;
474 }
475 EXPORT_SYMBOL(__sock_queue_rcv_skb);
476 
477 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
478 {
479         int err;
480 
481         err = sk_filter(sk, skb);
482         if (err)
483                 return err;
484 
485         return __sock_queue_rcv_skb(sk, skb);
486 }
487 EXPORT_SYMBOL(sock_queue_rcv_skb);
488 
489 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
490                      const int nested, unsigned int trim_cap, bool refcounted)
491 {
492         int rc = NET_RX_SUCCESS;
493 
494         if (sk_filter_trim_cap(sk, skb, trim_cap))
495                 goto discard_and_relse;
496 
497         skb->dev = NULL;
498 
499         if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
500                 atomic_inc(&sk->sk_drops);
501                 goto discard_and_relse;
502         }
503         if (nested)
504                 bh_lock_sock_nested(sk);
505         else
506                 bh_lock_sock(sk);
507         if (!sock_owned_by_user(sk)) {
508                 /*
509                  * trylock + unlock semantics:
510                  */
511                 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
512 
513                 rc = sk_backlog_rcv(sk, skb);
514 
515                 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
516         } else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
517                 bh_unlock_sock(sk);
518                 atomic_inc(&sk->sk_drops);
519                 goto discard_and_relse;
520         }
521 
522         bh_unlock_sock(sk);
523 out:
524         if (refcounted)
525                 sock_put(sk);
526         return rc;
527 discard_and_relse:
528         kfree_skb(skb);
529         goto out;
530 }
531 EXPORT_SYMBOL(__sk_receive_skb);
532 
533 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
534 {
535         struct dst_entry *dst = __sk_dst_get(sk);
536 
537         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
538                 sk_tx_queue_clear(sk);
539                 sk->sk_dst_pending_confirm = 0;
540                 RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
541                 dst_release(dst);
542                 return NULL;
543         }
544 
545         return dst;
546 }
547 EXPORT_SYMBOL(__sk_dst_check);
548 
549 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
550 {
551         struct dst_entry *dst = sk_dst_get(sk);
552 
553         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
554                 sk_dst_reset(sk);
555                 dst_release(dst);
556                 return NULL;
557         }
558 
559         return dst;
560 }
561 EXPORT_SYMBOL(sk_dst_check);
562 
563 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
564                                 int optlen)
565 {
566         int ret = -ENOPROTOOPT;
567 #ifdef CONFIG_NETDEVICES
568         struct net *net = sock_net(sk);
569         char devname[IFNAMSIZ];
570         int index;
571 
572         /* Sorry... */
573         ret = -EPERM;
574         if (!ns_capable(net->user_ns, CAP_NET_RAW))
575                 goto out;
576 
577         ret = -EINVAL;
578         if (optlen < 0)
579                 goto out;
580 
581         /* Bind this socket to a particular device like "eth0",
582          * as specified in the passed interface name. If the
583          * name is "" or the option length is zero the socket
584          * is not bound.
585          */
586         if (optlen > IFNAMSIZ - 1)
587                 optlen = IFNAMSIZ - 1;
588         memset(devname, 0, sizeof(devname));
589 
590         ret = -EFAULT;
591         if (copy_from_user(devname, optval, optlen))
592                 goto out;
593 
594         index = 0;
595         if (devname[0] != '\0') {
596                 struct net_device *dev;
597 
598                 rcu_read_lock();
599                 dev = dev_get_by_name_rcu(net, devname);
600                 if (dev)
601                         index = dev->ifindex;
602                 rcu_read_unlock();
603                 ret = -ENODEV;
604                 if (!dev)
605                         goto out;
606         }
607 
608         lock_sock(sk);
609         sk->sk_bound_dev_if = index;
610         sk_dst_reset(sk);
611         release_sock(sk);
612 
613         ret = 0;
614 
615 out:
616 #endif
617 
618         return ret;
619 }
620 
621 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
622                                 int __user *optlen, int len)
623 {
624         int ret = -ENOPROTOOPT;
625 #ifdef CONFIG_NETDEVICES
626         struct net *net = sock_net(sk);
627         char devname[IFNAMSIZ];
628 
629         if (sk->sk_bound_dev_if == 0) {
630                 len = 0;
631                 goto zero;
632         }
633 
634         ret = -EINVAL;
635         if (len < IFNAMSIZ)
636                 goto out;
637 
638         ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
639         if (ret)
640                 goto out;
641 
642         len = strlen(devname) + 1;
643 
644         ret = -EFAULT;
645         if (copy_to_user(optval, devname, len))
646                 goto out;
647 
648 zero:
649         ret = -EFAULT;
650         if (put_user(len, optlen))
651                 goto out;
652 
653         ret = 0;
654 
655 out:
656 #endif
657 
658         return ret;
659 }
660 
661 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
662 {
663         if (valbool)
664                 sock_set_flag(sk, bit);
665         else
666                 sock_reset_flag(sk, bit);
667 }
668 
669 bool sk_mc_loop(struct sock *sk)
670 {
671         if (dev_recursion_level())
672                 return false;
673         if (!sk)
674                 return true;
675         switch (sk->sk_family) {
676         case AF_INET:
677                 return inet_sk(sk)->mc_loop;
678 #if IS_ENABLED(CONFIG_IPV6)
679         case AF_INET6:
680                 return inet6_sk(sk)->mc_loop;
681 #endif
682         }
683         WARN_ON(1);
684         return true;
685 }
686 EXPORT_SYMBOL(sk_mc_loop);
687 
688 /*
689  *      This is meant for all protocols to use and covers goings on
690  *      at the socket level. Everything here is generic.
691  */
692 
693 int sock_setsockopt(struct socket *sock, int level, int optname,
694                     char __user *optval, unsigned int optlen)
695 {
696         struct sock *sk = sock->sk;
697         int val;
698         int valbool;
699         struct linger ling;
700         int ret = 0;
701 
702         /*
703          *      Options without arguments
704          */
705 
706         if (optname == SO_BINDTODEVICE)
707                 return sock_setbindtodevice(sk, optval, optlen);
708 
709         if (optlen < sizeof(int))
710                 return -EINVAL;
711 
712         if (get_user(val, (int __user *)optval))
713                 return -EFAULT;
714 
715         valbool = val ? 1 : 0;
716 
717         lock_sock(sk);
718 
719         switch (optname) {
720         case SO_DEBUG:
721                 if (val && !capable(CAP_NET_ADMIN))
722                         ret = -EACCES;
723                 else
724                         sock_valbool_flag(sk, SOCK_DBG, valbool);
725                 break;
726         case SO_REUSEADDR:
727                 sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
728                 break;
729         case SO_REUSEPORT:
730                 sk->sk_reuseport = valbool;
731                 break;
732         case SO_TYPE:
733         case SO_PROTOCOL:
734         case SO_DOMAIN:
735         case SO_ERROR:
736                 ret = -ENOPROTOOPT;
737                 break;
738         case SO_DONTROUTE:
739                 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
740                 break;
741         case SO_BROADCAST:
742                 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
743                 break;
744         case SO_SNDBUF:
745                 /* Don't error on this BSD doesn't and if you think
746                  * about it this is right. Otherwise apps have to
747                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
748                  * are treated in BSD as hints
749                  */
750                 val = min_t(u32, val, sysctl_wmem_max);
751 set_sndbuf:
752                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
753                 sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF);
754                 /* Wake up sending tasks if we upped the value. */
755                 sk->sk_write_space(sk);
756                 break;
757 
758         case SO_SNDBUFFORCE:
759                 if (!capable(CAP_NET_ADMIN)) {
760                         ret = -EPERM;
761                         break;
762                 }
763                 goto set_sndbuf;
764 
765         case SO_RCVBUF:
766                 /* Don't error on this BSD doesn't and if you think
767                  * about it this is right. Otherwise apps have to
768                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
769                  * are treated in BSD as hints
770                  */
771                 val = min_t(u32, val, sysctl_rmem_max);
772 set_rcvbuf:
773                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
774                 /*
775                  * We double it on the way in to account for
776                  * "struct sk_buff" etc. overhead.   Applications
777                  * assume that the SO_RCVBUF setting they make will
778                  * allow that much actual data to be received on that
779                  * socket.
780                  *
781                  * Applications are unaware that "struct sk_buff" and
782                  * other overheads allocate from the receive buffer
783                  * during socket buffer allocation.
784                  *
785                  * And after considering the possible alternatives,
786                  * returning the value we actually used in getsockopt
787                  * is the most desirable behavior.
788                  */
789                 sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
790                 break;
791 
792         case SO_RCVBUFFORCE:
793                 if (!capable(CAP_NET_ADMIN)) {
794                         ret = -EPERM;
795                         break;
796                 }
797                 goto set_rcvbuf;
798 
799         case SO_KEEPALIVE:
800                 if (sk->sk_prot->keepalive)
801                         sk->sk_prot->keepalive(sk, valbool);
802                 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
803                 break;
804 
805         case SO_OOBINLINE:
806                 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
807                 break;
808 
809         case SO_NO_CHECK:
810                 sk->sk_no_check_tx = valbool;
811                 break;
812 
813         case SO_PRIORITY:
814                 if ((val >= 0 && val <= 6) ||
815                     ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
816                         sk->sk_priority = val;
817                 else
818                         ret = -EPERM;
819                 break;
820 
821         case SO_LINGER:
822                 if (optlen < sizeof(ling)) {
823                         ret = -EINVAL;  /* 1003.1g */
824                         break;
825                 }
826                 if (copy_from_user(&ling, optval, sizeof(ling))) {
827                         ret = -EFAULT;
828                         break;
829                 }
830                 if (!ling.l_onoff)
831                         sock_reset_flag(sk, SOCK_LINGER);
832                 else {
833 #if (BITS_PER_LONG == 32)
834                         if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
835                                 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
836                         else
837 #endif
838                                 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
839                         sock_set_flag(sk, SOCK_LINGER);
840                 }
841                 break;
842 
843         case SO_BSDCOMPAT:
844                 sock_warn_obsolete_bsdism("setsockopt");
845                 break;
846 
847         case SO_PASSCRED:
848                 if (valbool)
849                         set_bit(SOCK_PASSCRED, &sock->flags);
850                 else
851                         clear_bit(SOCK_PASSCRED, &sock->flags);
852                 break;
853 
854         case SO_TIMESTAMP:
855         case SO_TIMESTAMPNS:
856                 if (valbool)  {
857                         if (optname == SO_TIMESTAMP)
858                                 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
859                         else
860                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
861                         sock_set_flag(sk, SOCK_RCVTSTAMP);
862                         sock_enable_timestamp(sk, SOCK_TIMESTAMP);
863                 } else {
864                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
865                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
866                 }
867                 break;
868 
869         case SO_TIMESTAMPING:
870                 if (val & ~SOF_TIMESTAMPING_MASK) {
871                         ret = -EINVAL;
872                         break;
873                 }
874 
875                 if (val & SOF_TIMESTAMPING_OPT_ID &&
876                     !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
877                         if (sk->sk_protocol == IPPROTO_TCP &&
878                             sk->sk_type == SOCK_STREAM) {
879                                 if ((1 << sk->sk_state) &
880                                     (TCPF_CLOSE | TCPF_LISTEN)) {
881                                         ret = -EINVAL;
882                                         break;
883                                 }
884                                 sk->sk_tskey = tcp_sk(sk)->snd_una;
885                         } else {
886                                 sk->sk_tskey = 0;
887                         }
888                 }
889 
890                 if (val & SOF_TIMESTAMPING_OPT_STATS &&
891                     !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
892                         ret = -EINVAL;
893                         break;
894                 }
895 
896                 sk->sk_tsflags = val;
897                 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
898                         sock_enable_timestamp(sk,
899                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
900                 else
901                         sock_disable_timestamp(sk,
902                                                (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
903                 break;
904 
905         case SO_RCVLOWAT:
906                 if (val < 0)
907                         val = INT_MAX;
908                 sk->sk_rcvlowat = val ? : 1;
909                 break;
910 
911         case SO_RCVTIMEO:
912                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
913                 break;
914 
915         case SO_SNDTIMEO:
916                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
917                 break;
918 
919         case SO_ATTACH_FILTER:
920                 ret = -EINVAL;
921                 if (optlen == sizeof(struct sock_fprog)) {
922                         struct sock_fprog fprog;
923 
924                         ret = -EFAULT;
925                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
926                                 break;
927 
928                         ret = sk_attach_filter(&fprog, sk);
929                 }
930                 break;
931 
932         case SO_ATTACH_BPF:
933                 ret = -EINVAL;
934                 if (optlen == sizeof(u32)) {
935                         u32 ufd;
936 
937                         ret = -EFAULT;
938                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
939                                 break;
940 
941                         ret = sk_attach_bpf(ufd, sk);
942                 }
943                 break;
944 
945         case SO_ATTACH_REUSEPORT_CBPF:
946                 ret = -EINVAL;
947                 if (optlen == sizeof(struct sock_fprog)) {
948                         struct sock_fprog fprog;
949 
950                         ret = -EFAULT;
951                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
952                                 break;
953 
954                         ret = sk_reuseport_attach_filter(&fprog, sk);
955                 }
956                 break;
957 
958         case SO_ATTACH_REUSEPORT_EBPF:
959                 ret = -EINVAL;
960                 if (optlen == sizeof(u32)) {
961                         u32 ufd;
962 
963                         ret = -EFAULT;
964                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
965                                 break;
966 
967                         ret = sk_reuseport_attach_bpf(ufd, sk);
968                 }
969                 break;
970 
971         case SO_DETACH_FILTER:
972                 ret = sk_detach_filter(sk);
973                 break;
974 
975         case SO_LOCK_FILTER:
976                 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
977                         ret = -EPERM;
978                 else
979                         sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
980                 break;
981 
982         case SO_PASSSEC:
983                 if (valbool)
984                         set_bit(SOCK_PASSSEC, &sock->flags);
985                 else
986                         clear_bit(SOCK_PASSSEC, &sock->flags);
987                 break;
988         case SO_MARK:
989                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
990                         ret = -EPERM;
991                 else
992                         sk->sk_mark = val;
993                 break;
994 
995         case SO_RXQ_OVFL:
996                 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
997                 break;
998 
999         case SO_WIFI_STATUS:
1000                 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1001                 break;
1002 
1003         case SO_PEEK_OFF:
1004                 if (sock->ops->set_peek_off)
1005                         ret = sock->ops->set_peek_off(sk, val);
1006                 else
1007                         ret = -EOPNOTSUPP;
1008                 break;
1009 
1010         case SO_NOFCS:
1011                 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1012                 break;
1013 
1014         case SO_SELECT_ERR_QUEUE:
1015                 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1016                 break;
1017 
1018 #ifdef CONFIG_NET_RX_BUSY_POLL
1019         case SO_BUSY_POLL:
1020                 /* allow unprivileged users to decrease the value */
1021                 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1022                         ret = -EPERM;
1023                 else {
1024                         if (val < 0)
1025                                 ret = -EINVAL;
1026                         else
1027                                 sk->sk_ll_usec = val;
1028                 }
1029                 break;
1030 #endif
1031 
1032         case SO_MAX_PACING_RATE:
1033                 if (val != ~0U)
1034                         cmpxchg(&sk->sk_pacing_status,
1035                                 SK_PACING_NONE,
1036                                 SK_PACING_NEEDED);
1037                 sk->sk_max_pacing_rate = val;
1038                 sk->sk_pacing_rate = min(sk->sk_pacing_rate,
1039                                          sk->sk_max_pacing_rate);
1040                 break;
1041 
1042         case SO_INCOMING_CPU:
1043                 sk->sk_incoming_cpu = val;
1044                 break;
1045 
1046         case SO_CNX_ADVICE:
1047                 if (val == 1)
1048                         dst_negative_advice(sk);
1049                 break;
1050 
1051         case SO_ZEROCOPY:
1052                 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1053                         if (sk->sk_protocol != IPPROTO_TCP)
1054                                 ret = -ENOTSUPP;
1055                 } else if (sk->sk_family != PF_RDS) {
1056                         ret = -ENOTSUPP;
1057                 }
1058                 if (!ret) {
1059                         if (val < 0 || val > 1)
1060                                 ret = -EINVAL;
1061                         else
1062                                 sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1063                 }
1064                 break;
1065 
1066         default:
1067                 ret = -ENOPROTOOPT;
1068                 break;
1069         }
1070         release_sock(sk);
1071         return ret;
1072 }
1073 EXPORT_SYMBOL(sock_setsockopt);
1074 
1075 
1076 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1077                           struct ucred *ucred)
1078 {
1079         ucred->pid = pid_vnr(pid);
1080         ucred->uid = ucred->gid = -1;
1081         if (cred) {
1082                 struct user_namespace *current_ns = current_user_ns();
1083 
1084                 ucred->uid = from_kuid_munged(current_ns, cred->euid);
1085                 ucred->gid = from_kgid_munged(current_ns, cred->egid);
1086         }
1087 }
1088 
1089 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1090 {
1091         struct user_namespace *user_ns = current_user_ns();
1092         int i;
1093 
1094         for (i = 0; i < src->ngroups; i++)
1095                 if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1096                         return -EFAULT;
1097 
1098         return 0;
1099 }
1100 
1101 int sock_getsockopt(struct socket *sock, int level, int optname,
1102                     char __user *optval, int __user *optlen)
1103 {
1104         struct sock *sk = sock->sk;
1105 
1106         union {
1107                 int val;
1108                 u64 val64;
1109                 struct linger ling;
1110                 struct timeval tm;
1111         } v;
1112 
1113         int lv = sizeof(int);
1114         int len;
1115 
1116         if (get_user(len, optlen))
1117                 return -EFAULT;
1118         if (len < 0)
1119                 return -EINVAL;
1120 
1121         memset(&v, 0, sizeof(v));
1122 
1123         switch (optname) {
1124         case SO_DEBUG:
1125                 v.val = sock_flag(sk, SOCK_DBG);
1126                 break;
1127 
1128         case SO_DONTROUTE:
1129                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
1130                 break;
1131 
1132         case SO_BROADCAST:
1133                 v.val = sock_flag(sk, SOCK_BROADCAST);
1134                 break;
1135 
1136         case SO_SNDBUF:
1137                 v.val = sk->sk_sndbuf;
1138                 break;
1139 
1140         case SO_RCVBUF:
1141                 v.val = sk->sk_rcvbuf;
1142                 break;
1143 
1144         case SO_REUSEADDR:
1145                 v.val = sk->sk_reuse;
1146                 break;
1147 
1148         case SO_REUSEPORT:
1149                 v.val = sk->sk_reuseport;
1150                 break;
1151 
1152         case SO_KEEPALIVE:
1153                 v.val = sock_flag(sk, SOCK_KEEPOPEN);
1154                 break;
1155 
1156         case SO_TYPE:
1157                 v.val = sk->sk_type;
1158                 break;
1159 
1160         case SO_PROTOCOL:
1161                 v.val = sk->sk_protocol;
1162                 break;
1163 
1164         case SO_DOMAIN:
1165                 v.val = sk->sk_family;
1166                 break;
1167 
1168         case SO_ERROR:
1169                 v.val = -sock_error(sk);
1170                 if (v.val == 0)
1171                         v.val = xchg(&sk->sk_err_soft, 0);
1172                 break;
1173 
1174         case SO_OOBINLINE:
1175                 v.val = sock_flag(sk, SOCK_URGINLINE);
1176                 break;
1177 
1178         case SO_NO_CHECK:
1179                 v.val = sk->sk_no_check_tx;
1180                 break;
1181 
1182         case SO_PRIORITY:
1183                 v.val = sk->sk_priority;
1184                 break;
1185 
1186         case SO_LINGER:
1187                 lv              = sizeof(v.ling);
1188                 v.ling.l_onoff  = sock_flag(sk, SOCK_LINGER);
1189                 v.ling.l_linger = sk->sk_lingertime / HZ;
1190                 break;
1191 
1192         case SO_BSDCOMPAT:
1193                 sock_warn_obsolete_bsdism("getsockopt");
1194                 break;
1195 
1196         case SO_TIMESTAMP:
1197                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1198                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1199                 break;
1200 
1201         case SO_TIMESTAMPNS:
1202                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1203                 break;
1204 
1205         case SO_TIMESTAMPING:
1206                 v.val = sk->sk_tsflags;
1207                 break;
1208 
1209         case SO_RCVTIMEO:
1210                 lv = sizeof(struct timeval);
1211                 if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1212                         v.tm.tv_sec = 0;
1213                         v.tm.tv_usec = 0;
1214                 } else {
1215                         v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1216                         v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * USEC_PER_SEC) / HZ;
1217                 }
1218                 break;
1219 
1220         case SO_SNDTIMEO:
1221                 lv = sizeof(struct timeval);
1222                 if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1223                         v.tm.tv_sec = 0;
1224                         v.tm.tv_usec = 0;
1225                 } else {
1226                         v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1227                         v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * USEC_PER_SEC) / HZ;
1228                 }
1229                 break;
1230 
1231         case SO_RCVLOWAT:
1232                 v.val = sk->sk_rcvlowat;
1233                 break;
1234 
1235         case SO_SNDLOWAT:
1236                 v.val = 1;
1237                 break;
1238 
1239         case SO_PASSCRED:
1240                 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1241                 break;
1242 
1243         case SO_PEERCRED:
1244         {
1245                 struct ucred peercred;
1246                 if (len > sizeof(peercred))
1247                         len = sizeof(peercred);
1248                 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1249                 if (copy_to_user(optval, &peercred, len))
1250                         return -EFAULT;
1251                 goto lenout;
1252         }
1253 
1254         case SO_PEERGROUPS:
1255         {
1256                 int ret, n;
1257 
1258                 if (!sk->sk_peer_cred)
1259                         return -ENODATA;
1260 
1261                 n = sk->sk_peer_cred->group_info->ngroups;
1262                 if (len < n * sizeof(gid_t)) {
1263                         len = n * sizeof(gid_t);
1264                         return put_user(len, optlen) ? -EFAULT : -ERANGE;
1265                 }
1266                 len = n * sizeof(gid_t);
1267 
1268                 ret = groups_to_user((gid_t __user *)optval,
1269                                      sk->sk_peer_cred->group_info);
1270                 if (ret)
1271                         return ret;
1272                 goto lenout;
1273         }
1274 
1275         case SO_PEERNAME:
1276         {
1277                 char address[128];
1278 
1279                 lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1280                 if (lv < 0)
1281                         return -ENOTCONN;
1282                 if (lv < len)
1283                         return -EINVAL;
1284                 if (copy_to_user(optval, address, len))
1285                         return -EFAULT;
1286                 goto lenout;
1287         }
1288 
1289         /* Dubious BSD thing... Probably nobody even uses it, but
1290          * the UNIX standard wants it for whatever reason... -DaveM
1291          */
1292         case SO_ACCEPTCONN:
1293                 v.val = sk->sk_state == TCP_LISTEN;
1294                 break;
1295 
1296         case SO_PASSSEC:
1297                 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1298                 break;
1299 
1300         case SO_PEERSEC:
1301                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1302 
1303         case SO_MARK:
1304                 v.val = sk->sk_mark;
1305                 break;
1306 
1307         case SO_RXQ_OVFL:
1308                 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1309                 break;
1310 
1311         case SO_WIFI_STATUS:
1312                 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1313                 break;
1314 
1315         case SO_PEEK_OFF:
1316                 if (!sock->ops->set_peek_off)
1317                         return -EOPNOTSUPP;
1318 
1319                 v.val = sk->sk_peek_off;
1320                 break;
1321         case SO_NOFCS:
1322                 v.val = sock_flag(sk, SOCK_NOFCS);
1323                 break;
1324 
1325         case SO_BINDTODEVICE:
1326                 return sock_getbindtodevice(sk, optval, optlen, len);
1327 
1328         case SO_GET_FILTER:
1329                 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1330                 if (len < 0)
1331                         return len;
1332 
1333                 goto lenout;
1334 
1335         case SO_LOCK_FILTER:
1336                 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1337                 break;
1338 
1339         case SO_BPF_EXTENSIONS:
1340                 v.val = bpf_tell_extensions();
1341                 break;
1342 
1343         case SO_SELECT_ERR_QUEUE:
1344                 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1345                 break;
1346 
1347 #ifdef CONFIG_NET_RX_BUSY_POLL
1348         case SO_BUSY_POLL:
1349                 v.val = sk->sk_ll_usec;
1350                 break;
1351 #endif
1352 
1353         case SO_MAX_PACING_RATE:
1354                 v.val = sk->sk_max_pacing_rate;
1355                 break;
1356 
1357         case SO_INCOMING_CPU:
1358                 v.val = sk->sk_incoming_cpu;
1359                 break;
1360 
1361         case SO_MEMINFO:
1362         {
1363                 u32 meminfo[SK_MEMINFO_VARS];
1364 
1365                 if (get_user(len, optlen))
1366                         return -EFAULT;
1367 
1368                 sk_get_meminfo(sk, meminfo);
1369 
1370                 len = min_t(unsigned int, len, sizeof(meminfo));
1371                 if (copy_to_user(optval, &meminfo, len))
1372                         return -EFAULT;
1373 
1374                 goto lenout;
1375         }
1376 
1377 #ifdef CONFIG_NET_RX_BUSY_POLL
1378         case SO_INCOMING_NAPI_ID:
1379                 v.val = READ_ONCE(sk->sk_napi_id);
1380 
1381                 /* aggregate non-NAPI IDs down to 0 */
1382                 if (v.val < MIN_NAPI_ID)
1383                         v.val = 0;
1384 
1385                 break;
1386 #endif
1387 
1388         case SO_COOKIE:
1389                 lv = sizeof(u64);
1390                 if (len < lv)
1391                         return -EINVAL;
1392                 v.val64 = sock_gen_cookie(sk);
1393                 break;
1394 
1395         case SO_ZEROCOPY:
1396                 v.val = sock_flag(sk, SOCK_ZEROCOPY);
1397                 break;
1398 
1399         default:
1400                 /* We implement the SO_SNDLOWAT etc to not be settable
1401                  * (1003.1g 7).
1402                  */
1403                 return -ENOPROTOOPT;
1404         }
1405 
1406         if (len > lv)
1407                 len = lv;
1408         if (copy_to_user(optval, &v, len))
1409                 return -EFAULT;
1410 lenout:
1411         if (put_user(len, optlen))
1412                 return -EFAULT;
1413         return 0;
1414 }
1415 
1416 /*
1417  * Initialize an sk_lock.
1418  *
1419  * (We also register the sk_lock with the lock validator.)
1420  */
1421 static inline void sock_lock_init(struct sock *sk)
1422 {
1423         if (sk->sk_kern_sock)
1424                 sock_lock_init_class_and_name(
1425                         sk,
1426                         af_family_kern_slock_key_strings[sk->sk_family],
1427                         af_family_kern_slock_keys + sk->sk_family,
1428                         af_family_kern_key_strings[sk->sk_family],
1429                         af_family_kern_keys + sk->sk_family);
1430         else
1431                 sock_lock_init_class_and_name(
1432                         sk,
1433                         af_family_slock_key_strings[sk->sk_family],
1434                         af_family_slock_keys + sk->sk_family,
1435                         af_family_key_strings[sk->sk_family],
1436                         af_family_keys + sk->sk_family);
1437 }
1438 
1439 /*
1440  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1441  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1442  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1443  */
1444 static void sock_copy(struct sock *nsk, const struct sock *osk)
1445 {
1446 #ifdef CONFIG_SECURITY_NETWORK
1447         void *sptr = nsk->sk_security;
1448 #endif
1449         memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1450 
1451         memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1452                osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1453 
1454 #ifdef CONFIG_SECURITY_NETWORK
1455         nsk->sk_security = sptr;
1456         security_sk_clone(osk, nsk);
1457 #endif
1458 }
1459 
1460 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1461                 int family)
1462 {
1463         struct sock *sk;
1464         struct kmem_cache *slab;
1465 
1466         slab = prot->slab;
1467         if (slab != NULL) {
1468                 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1469                 if (!sk)
1470                         return sk;
1471                 if (priority & __GFP_ZERO)
1472                         sk_prot_clear_nulls(sk, prot->obj_size);
1473         } else
1474                 sk = kmalloc(prot->obj_size, priority);
1475 
1476         if (sk != NULL) {
1477                 if (security_sk_alloc(sk, family, priority))
1478                         goto out_free;
1479 
1480                 if (!try_module_get(prot->owner))
1481                         goto out_free_sec;
1482                 sk_tx_queue_clear(sk);
1483         }
1484 
1485         return sk;
1486 
1487 out_free_sec:
1488         security_sk_free(sk);
1489 out_free:
1490         if (slab != NULL)
1491                 kmem_cache_free(slab, sk);
1492         else
1493                 kfree(sk);
1494         return NULL;
1495 }
1496 
1497 static void sk_prot_free(struct proto *prot, struct sock *sk)
1498 {
1499         struct kmem_cache *slab;
1500         struct module *owner;
1501 
1502         owner = prot->owner;
1503         slab = prot->slab;
1504 
1505         cgroup_sk_free(&sk->sk_cgrp_data);
1506         mem_cgroup_sk_free(sk);
1507         security_sk_free(sk);
1508         if (slab != NULL)
1509                 kmem_cache_free(slab, sk);
1510         else
1511                 kfree(sk);
1512         module_put(owner);
1513 }
1514 
1515 /**
1516  *      sk_alloc - All socket objects are allocated here
1517  *      @net: the applicable net namespace
1518  *      @family: protocol family
1519  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1520  *      @prot: struct proto associated with this new sock instance
1521  *      @kern: is this to be a kernel socket?
1522  */
1523 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1524                       struct proto *prot, int kern)
1525 {
1526         struct sock *sk;
1527 
1528         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1529         if (sk) {
1530                 sk->sk_family = family;
1531                 /*
1532                  * See comment in struct sock definition to understand
1533                  * why we need sk_prot_creator -acme
1534                  */
1535                 sk->sk_prot = sk->sk_prot_creator = prot;
1536                 sk->sk_kern_sock = kern;
1537                 sock_lock_init(sk);
1538                 sk->sk_net_refcnt = kern ? 0 : 1;
1539                 if (likely(sk->sk_net_refcnt)) {
1540                         get_net(net);
1541                         sock_inuse_add(net, 1);
1542                 }
1543 
1544                 sock_net_set(sk, net);
1545                 refcount_set(&sk->sk_wmem_alloc, 1);
1546 
1547                 mem_cgroup_sk_alloc(sk);
1548                 cgroup_sk_alloc(&sk->sk_cgrp_data);
1549                 sock_update_classid(&sk->sk_cgrp_data);
1550                 sock_update_netprioidx(&sk->sk_cgrp_data);
1551         }
1552 
1553         return sk;
1554 }
1555 EXPORT_SYMBOL(sk_alloc);
1556 
1557 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1558  * grace period. This is the case for UDP sockets and TCP listeners.
1559  */
1560 static void __sk_destruct(struct rcu_head *head)
1561 {
1562         struct sock *sk = container_of(head, struct sock, sk_rcu);
1563         struct sk_filter *filter;
1564 
1565         if (sk->sk_destruct)
1566                 sk->sk_destruct(sk);
1567 
1568         filter = rcu_dereference_check(sk->sk_filter,
1569                                        refcount_read(&sk->sk_wmem_alloc) == 0);
1570         if (filter) {
1571                 sk_filter_uncharge(sk, filter);
1572                 RCU_INIT_POINTER(sk->sk_filter, NULL);
1573         }
1574         if (rcu_access_pointer(sk->sk_reuseport_cb))
1575                 reuseport_detach_sock(sk);
1576 
1577         sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1578 
1579         if (atomic_read(&sk->sk_omem_alloc))
1580                 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1581                          __func__, atomic_read(&sk->sk_omem_alloc));
1582 
1583         if (sk->sk_frag.page) {
1584                 put_page(sk->sk_frag.page);
1585                 sk->sk_frag.page = NULL;
1586         }
1587 
1588         if (sk->sk_peer_cred)
1589                 put_cred(sk->sk_peer_cred);
1590         put_pid(sk->sk_peer_pid);
1591         if (likely(sk->sk_net_refcnt))
1592                 put_net(sock_net(sk));
1593         sk_prot_free(sk->sk_prot_creator, sk);
1594 }
1595 
1596 void sk_destruct(struct sock *sk)
1597 {
1598         if (sock_flag(sk, SOCK_RCU_FREE))
1599                 call_rcu(&sk->sk_rcu, __sk_destruct);
1600         else
1601                 __sk_destruct(&sk->sk_rcu);
1602 }
1603 
1604 static void __sk_free(struct sock *sk)
1605 {
1606         if (likely(sk->sk_net_refcnt))
1607                 sock_inuse_add(sock_net(sk), -1);
1608 
1609         if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1610                 sock_diag_broadcast_destroy(sk);
1611         else
1612                 sk_destruct(sk);
1613 }
1614 
1615 void sk_free(struct sock *sk)
1616 {
1617         /*
1618          * We subtract one from sk_wmem_alloc and can know if
1619          * some packets are still in some tx queue.
1620          * If not null, sock_wfree() will call __sk_free(sk) later
1621          */
1622         if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1623                 __sk_free(sk);
1624 }
1625 EXPORT_SYMBOL(sk_free);
1626 
1627 static void sk_init_common(struct sock *sk)
1628 {
1629         skb_queue_head_init(&sk->sk_receive_queue);
1630         skb_queue_head_init(&sk->sk_write_queue);
1631         skb_queue_head_init(&sk->sk_error_queue);
1632 
1633         rwlock_init(&sk->sk_callback_lock);
1634         lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1635                         af_rlock_keys + sk->sk_family,
1636                         af_family_rlock_key_strings[sk->sk_family]);
1637         lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1638                         af_wlock_keys + sk->sk_family,
1639                         af_family_wlock_key_strings[sk->sk_family]);
1640         lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1641                         af_elock_keys + sk->sk_family,
1642                         af_family_elock_key_strings[sk->sk_family]);
1643         lockdep_set_class_and_name(&sk->sk_callback_lock,
1644                         af_callback_keys + sk->sk_family,
1645                         af_family_clock_key_strings[sk->sk_family]);
1646 }
1647 
1648 /**
1649  *      sk_clone_lock - clone a socket, and lock its clone
1650  *      @sk: the socket to clone
1651  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1652  *
1653  *      Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1654  */
1655 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1656 {
1657         struct sock *newsk;
1658         bool is_charged = true;
1659 
1660         newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1661         if (newsk != NULL) {
1662                 struct sk_filter *filter;
1663 
1664                 sock_copy(newsk, sk);
1665 
1666                 newsk->sk_prot_creator = sk->sk_prot;
1667 
1668                 /* SANITY */
1669                 if (likely(newsk->sk_net_refcnt))
1670                         get_net(sock_net(newsk));
1671                 sk_node_init(&newsk->sk_node);
1672                 sock_lock_init(newsk);
1673                 bh_lock_sock(newsk);
1674                 newsk->sk_backlog.head  = newsk->sk_backlog.tail = NULL;
1675                 newsk->sk_backlog.len = 0;
1676 
1677                 atomic_set(&newsk->sk_rmem_alloc, 0);
1678                 /*
1679                  * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1680                  */
1681                 refcount_set(&newsk->sk_wmem_alloc, 1);
1682                 atomic_set(&newsk->sk_omem_alloc, 0);
1683                 sk_init_common(newsk);
1684 
1685                 newsk->sk_dst_cache     = NULL;
1686                 newsk->sk_dst_pending_confirm = 0;
1687                 newsk->sk_wmem_queued   = 0;
1688                 newsk->sk_forward_alloc = 0;
1689                 atomic_set(&newsk->sk_drops, 0);
1690                 newsk->sk_send_head     = NULL;
1691                 newsk->sk_userlocks     = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1692                 atomic_set(&newsk->sk_zckey, 0);
1693 
1694                 sock_reset_flag(newsk, SOCK_DONE);
1695                 mem_cgroup_sk_alloc(newsk);
1696                 cgroup_sk_alloc(&newsk->sk_cgrp_data);
1697 
1698                 rcu_read_lock();
1699                 filter = rcu_dereference(sk->sk_filter);
1700                 if (filter != NULL)
1701                         /* though it's an empty new sock, the charging may fail
1702                          * if sysctl_optmem_max was changed between creation of
1703                          * original socket and cloning
1704                          */
1705                         is_charged = sk_filter_charge(newsk, filter);
1706                 RCU_INIT_POINTER(newsk->sk_filter, filter);
1707                 rcu_read_unlock();
1708 
1709                 if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1710                         /* We need to make sure that we don't uncharge the new
1711                          * socket if we couldn't charge it in the first place
1712                          * as otherwise we uncharge the parent's filter.
1713                          */
1714                         if (!is_charged)
1715                                 RCU_INIT_POINTER(newsk->sk_filter, NULL);
1716                         sk_free_unlock_clone(newsk);
1717                         newsk = NULL;
1718                         goto out;
1719                 }
1720                 RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1721 
1722                 newsk->sk_err      = 0;
1723                 newsk->sk_err_soft = 0;
1724                 newsk->sk_priority = 0;
1725                 newsk->sk_incoming_cpu = raw_smp_processor_id();
1726                 atomic64_set(&newsk->sk_cookie, 0);
1727                 if (likely(newsk->sk_net_refcnt))
1728                         sock_inuse_add(sock_net(newsk), 1);
1729 
1730                 /*
1731                  * Before updating sk_refcnt, we must commit prior changes to memory
1732                  * (Documentation/RCU/rculist_nulls.txt for details)
1733                  */
1734                 smp_wmb();
1735                 refcount_set(&newsk->sk_refcnt, 2);
1736 
1737                 /*
1738                  * Increment the counter in the same struct proto as the master
1739                  * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1740                  * is the same as sk->sk_prot->socks, as this field was copied
1741                  * with memcpy).
1742                  *
1743                  * This _changes_ the previous behaviour, where
1744                  * tcp_create_openreq_child always was incrementing the
1745                  * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1746                  * to be taken into account in all callers. -acme
1747                  */
1748                 sk_refcnt_debug_inc(newsk);
1749                 sk_set_socket(newsk, NULL);
1750                 newsk->sk_wq = NULL;
1751 
1752                 if (newsk->sk_prot->sockets_allocated)
1753                         sk_sockets_allocated_inc(newsk);
1754 
1755                 if (sock_needs_netstamp(sk) &&
1756                     newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1757                         net_enable_timestamp();
1758         }
1759 out:
1760         return newsk;
1761 }
1762 EXPORT_SYMBOL_GPL(sk_clone_lock);
1763 
1764 void sk_free_unlock_clone(struct sock *sk)
1765 {
1766         /* It is still raw copy of parent, so invalidate
1767          * destructor and make plain sk_free() */
1768         sk->sk_destruct = NULL;
1769         bh_unlock_sock(sk);
1770         sk_free(sk);
1771 }
1772 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1773 
1774 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1775 {
1776         u32 max_segs = 1;
1777 
1778         sk_dst_set(sk, dst);
1779         sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1780         if (sk->sk_route_caps & NETIF_F_GSO)
1781                 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1782         sk->sk_route_caps &= ~sk->sk_route_nocaps;
1783         if (sk_can_gso(sk)) {
1784                 if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1785                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1786                 } else {
1787                         sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1788                         sk->sk_gso_max_size = dst->dev->gso_max_size;
1789                         max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1790                 }
1791         }
1792         sk->sk_gso_max_segs = max_segs;
1793 }
1794 EXPORT_SYMBOL_GPL(sk_setup_caps);
1795 
1796 /*
1797  *      Simple resource managers for sockets.
1798  */
1799 
1800 
1801 /*
1802  * Write buffer destructor automatically called from kfree_skb.
1803  */
1804 void sock_wfree(struct sk_buff *skb)
1805 {
1806         struct sock *sk = skb->sk;
1807         unsigned int len = skb->truesize;
1808 
1809         if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1810                 /*
1811                  * Keep a reference on sk_wmem_alloc, this will be released
1812                  * after sk_write_space() call
1813                  */
1814                 WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1815                 sk->sk_write_space(sk);
1816                 len = 1;
1817         }
1818         /*
1819          * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1820          * could not do because of in-flight packets
1821          */
1822         if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1823                 __sk_free(sk);
1824 }
1825 EXPORT_SYMBOL(sock_wfree);
1826 
1827 /* This variant of sock_wfree() is used by TCP,
1828  * since it sets SOCK_USE_WRITE_QUEUE.
1829  */
1830 void __sock_wfree(struct sk_buff *skb)
1831 {
1832         struct sock *sk = skb->sk;
1833 
1834         if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1835                 __sk_free(sk);
1836 }
1837 
1838 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1839 {
1840         skb_orphan(skb);
1841         skb->sk = sk;
1842 #ifdef CONFIG_INET
1843         if (unlikely(!sk_fullsock(sk))) {
1844                 skb->destructor = sock_edemux;
1845                 sock_hold(sk);
1846                 return;
1847         }
1848 #endif
1849         skb->destructor = sock_wfree;
1850         skb_set_hash_from_sk(skb, sk);
1851         /*
1852          * We used to take a refcount on sk, but following operation
1853          * is enough to guarantee sk_free() wont free this sock until
1854          * all in-flight packets are completed
1855          */
1856         refcount_add(skb->truesize, &sk->sk_wmem_alloc);
1857 }
1858 EXPORT_SYMBOL(skb_set_owner_w);
1859 
1860 /* This helper is used by netem, as it can hold packets in its
1861  * delay queue. We want to allow the owner socket to send more
1862  * packets, as if they were already TX completed by a typical driver.
1863  * But we also want to keep skb->sk set because some packet schedulers
1864  * rely on it (sch_fq for example).
1865  */
1866 void skb_orphan_partial(struct sk_buff *skb)
1867 {
1868         if (skb_is_tcp_pure_ack(skb))
1869                 return;
1870 
1871         if (skb->destructor == sock_wfree
1872 #ifdef CONFIG_INET
1873             || skb->destructor == tcp_wfree
1874 #endif
1875                 ) {
1876                 struct sock *sk = skb->sk;
1877 
1878                 if (refcount_inc_not_zero(&sk->sk_refcnt)) {
1879                         WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
1880                         skb->destructor = sock_efree;
1881                 }
1882         } else {
1883                 skb_orphan(skb);
1884         }
1885 }
1886 EXPORT_SYMBOL(skb_orphan_partial);
1887 
1888 /*
1889  * Read buffer destructor automatically called from kfree_skb.
1890  */
1891 void sock_rfree(struct sk_buff *skb)
1892 {
1893         struct sock *sk = skb->sk;
1894         unsigned int len = skb->truesize;
1895 
1896         atomic_sub(len, &sk->sk_rmem_alloc);
1897         sk_mem_uncharge(sk, len);
1898 }
1899 EXPORT_SYMBOL(sock_rfree);
1900 
1901 /*
1902  * Buffer destructor for skbs that are not used directly in read or write
1903  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
1904  */
1905 void sock_efree(struct sk_buff *skb)
1906 {
1907         sock_put(skb->sk);
1908 }
1909 EXPORT_SYMBOL(sock_efree);
1910 
1911 kuid_t sock_i_uid(struct sock *sk)
1912 {
1913         kuid_t uid;
1914 
1915         read_lock_bh(&sk->sk_callback_lock);
1916         uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1917         read_unlock_bh(&sk->sk_callback_lock);
1918         return uid;
1919 }
1920 EXPORT_SYMBOL(sock_i_uid);
1921 
1922 unsigned long sock_i_ino(struct sock *sk)
1923 {
1924         unsigned long ino;
1925 
1926         read_lock_bh(&sk->sk_callback_lock);
1927         ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1928         read_unlock_bh(&sk->sk_callback_lock);
1929         return ino;
1930 }
1931 EXPORT_SYMBOL(sock_i_ino);
1932 
1933 /*
1934  * Allocate a skb from the socket's send buffer.
1935  */
1936 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1937                              gfp_t priority)
1938 {
1939         if (force || refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1940                 struct sk_buff *skb = alloc_skb(size, priority);
1941                 if (skb) {
1942                         skb_set_owner_w(skb, sk);
1943                         return skb;
1944                 }
1945         }
1946         return NULL;
1947 }
1948 EXPORT_SYMBOL(sock_wmalloc);
1949 
1950 static void sock_ofree(struct sk_buff *skb)
1951 {
1952         struct sock *sk = skb->sk;
1953 
1954         atomic_sub(skb->truesize, &sk->sk_omem_alloc);
1955 }
1956 
1957 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
1958                              gfp_t priority)
1959 {
1960         struct sk_buff *skb;
1961 
1962         /* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
1963         if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
1964             sysctl_optmem_max)
1965                 return NULL;
1966 
1967         skb = alloc_skb(size, priority);
1968         if (!skb)
1969                 return NULL;
1970 
1971         atomic_add(skb->truesize, &sk->sk_omem_alloc);
1972         skb->sk = sk;
1973         skb->destructor = sock_ofree;
1974         return skb;
1975 }
1976 
1977 /*
1978  * Allocate a memory block from the socket's option memory buffer.
1979  */
1980 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1981 {
1982         if ((unsigned int)size <= sysctl_optmem_max &&
1983             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1984                 void *mem;
1985                 /* First do the add, to avoid the race if kmalloc
1986                  * might sleep.
1987                  */
1988                 atomic_add(size, &sk->sk_omem_alloc);
1989                 mem = kmalloc(size, priority);
1990                 if (mem)
1991                         return mem;
1992                 atomic_sub(size, &sk->sk_omem_alloc);
1993         }
1994         return NULL;
1995 }
1996 EXPORT_SYMBOL(sock_kmalloc);
1997 
1998 /* Free an option memory block. Note, we actually want the inline
1999  * here as this allows gcc to detect the nullify and fold away the
2000  * condition entirely.
2001  */
2002 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2003                                   const bool nullify)
2004 {
2005         if (WARN_ON_ONCE(!mem))
2006                 return;
2007         if (nullify)
2008                 kzfree(mem);
2009         else
2010                 kfree(mem);
2011         atomic_sub(size, &sk->sk_omem_alloc);
2012 }
2013 
2014 void sock_kfree_s(struct sock *sk, void *mem, int size)
2015 {
2016         __sock_kfree_s(sk, mem, size, false);
2017 }
2018 EXPORT_SYMBOL(sock_kfree_s);
2019 
2020 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2021 {
2022         __sock_kfree_s(sk, mem, size, true);
2023 }
2024 EXPORT_SYMBOL(sock_kzfree_s);
2025 
2026 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2027    I think, these locks should be removed for datagram sockets.
2028  */
2029 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2030 {
2031         DEFINE_WAIT(wait);
2032 
2033         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2034         for (;;) {
2035                 if (!timeo)
2036                         break;
2037                 if (signal_pending(current))
2038                         break;
2039                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2040                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2041                 if (refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
2042                         break;
2043                 if (sk->sk_shutdown & SEND_SHUTDOWN)
2044                         break;
2045                 if (sk->sk_err)
2046                         break;
2047                 timeo = schedule_timeout(timeo);
2048         }
2049         finish_wait(sk_sleep(sk), &wait);
2050         return timeo;
2051 }
2052 
2053 
2054 /*
2055  *      Generic send/receive buffer handlers
2056  */
2057 
2058 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2059                                      unsigned long data_len, int noblock,
2060                                      int *errcode, int max_page_order)
2061 {
2062         struct sk_buff *skb;
2063         long timeo;
2064         int err;
2065 
2066         timeo = sock_sndtimeo(sk, noblock);
2067         for (;;) {
2068                 err = sock_error(sk);
2069                 if (err != 0)
2070                         goto failure;
2071 
2072                 err = -EPIPE;
2073                 if (sk->sk_shutdown & SEND_SHUTDOWN)
2074                         goto failure;
2075 
2076                 if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
2077                         break;
2078 
2079                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2080                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2081                 err = -EAGAIN;
2082                 if (!timeo)
2083                         goto failure;
2084                 if (signal_pending(current))
2085                         goto interrupted;
2086                 timeo = sock_wait_for_wmem(sk, timeo);
2087         }
2088         skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2089                                    errcode, sk->sk_allocation);
2090         if (skb)
2091                 skb_set_owner_w(skb, sk);
2092         return skb;
2093 
2094 interrupted:
2095         err = sock_intr_errno(timeo);
2096 failure:
2097         *errcode = err;
2098         return NULL;
2099 }
2100 EXPORT_SYMBOL(sock_alloc_send_pskb);
2101 
2102 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2103                                     int noblock, int *errcode)
2104 {
2105         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2106 }
2107 EXPORT_SYMBOL(sock_alloc_send_skb);
2108 
2109 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2110                      struct sockcm_cookie *sockc)
2111 {
2112         u32 tsflags;
2113 
2114         switch (cmsg->cmsg_type) {
2115         case SO_MARK:
2116                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2117                         return -EPERM;
2118                 if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2119                         return -EINVAL;
2120                 sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2121                 break;
2122         case SO_TIMESTAMPING:
2123                 if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2124                         return -EINVAL;
2125 
2126                 tsflags = *(u32 *)CMSG_DATA(cmsg);
2127                 if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2128                         return -EINVAL;
2129 
2130                 sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2131                 sockc->tsflags |= tsflags;
2132                 break;
2133         /* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2134         case SCM_RIGHTS:
2135         case SCM_CREDENTIALS:
2136                 break;
2137         default:
2138                 return -EINVAL;
2139         }
2140         return 0;
2141 }
2142 EXPORT_SYMBOL(__sock_cmsg_send);
2143 
2144 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2145                    struct sockcm_cookie *sockc)
2146 {
2147         struct cmsghdr *cmsg;
2148         int ret;
2149 
2150         for_each_cmsghdr(cmsg, msg) {
2151                 if (!CMSG_OK(msg, cmsg))
2152                         return -EINVAL;
2153                 if (cmsg->cmsg_level != SOL_SOCKET)
2154                         continue;
2155                 ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2156                 if (ret)
2157                         return ret;
2158         }
2159         return 0;
2160 }
2161 EXPORT_SYMBOL(sock_cmsg_send);
2162 
2163 static void sk_enter_memory_pressure(struct sock *sk)
2164 {
2165         if (!sk->sk_prot->enter_memory_pressure)
2166                 return;
2167 
2168         sk->sk_prot->enter_memory_pressure(sk);
2169 }
2170 
2171 static void sk_leave_memory_pressure(struct sock *sk)
2172 {
2173         if (sk->sk_prot->leave_memory_pressure) {
2174                 sk->sk_prot->leave_memory_pressure(sk);
2175         } else {
2176                 unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2177 
2178                 if (memory_pressure && *memory_pressure)
2179                         *memory_pressure = 0;
2180         }
2181 }
2182 
2183 /* On 32bit arches, an skb frag is limited to 2^15 */
2184 #define SKB_FRAG_PAGE_ORDER     get_order(32768)
2185 
2186 /**
2187  * skb_page_frag_refill - check that a page_frag contains enough room
2188  * @sz: minimum size of the fragment we want to get
2189  * @pfrag: pointer to page_frag
2190  * @gfp: priority for memory allocation
2191  *
2192  * Note: While this allocator tries to use high order pages, there is
2193  * no guarantee that allocations succeed. Therefore, @sz MUST be
2194  * less or equal than PAGE_SIZE.
2195  */
2196 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2197 {
2198         if (pfrag->page) {
2199                 if (page_ref_count(pfrag->page) == 1) {
2200                         pfrag->offset = 0;
2201                         return true;
2202                 }
2203                 if (pfrag->offset + sz <= pfrag->size)
2204                         return true;
2205                 put_page(pfrag->page);
2206         }
2207 
2208         pfrag->offset = 0;
2209         if (SKB_FRAG_PAGE_ORDER) {
2210                 /* Avoid direct reclaim but allow kswapd to wake */
2211                 pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2212                                           __GFP_COMP | __GFP_NOWARN |
2213                                           __GFP_NORETRY,
2214                                           SKB_FRAG_PAGE_ORDER);
2215                 if (likely(pfrag->page)) {
2216                         pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2217                         return true;
2218                 }
2219         }
2220         pfrag->page = alloc_page(gfp);
2221         if (likely(pfrag->page)) {
2222                 pfrag->size = PAGE_SIZE;
2223                 return true;
2224         }
2225         return false;
2226 }
2227 EXPORT_SYMBOL(skb_page_frag_refill);
2228 
2229 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2230 {
2231         if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2232                 return true;
2233 
2234         sk_enter_memory_pressure(sk);
2235         sk_stream_moderate_sndbuf(sk);
2236         return false;
2237 }
2238 EXPORT_SYMBOL(sk_page_frag_refill);
2239 
2240 int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg,
2241                 int sg_start, int *sg_curr_index, unsigned int *sg_curr_size,
2242                 int first_coalesce)
2243 {
2244         int sg_curr = *sg_curr_index, use = 0, rc = 0;
2245         unsigned int size = *sg_curr_size;
2246         struct page_frag *pfrag;
2247         struct scatterlist *sge;
2248 
2249         len -= size;
2250         pfrag = sk_page_frag(sk);
2251 
2252         while (len > 0) {
2253                 unsigned int orig_offset;
2254 
2255                 if (!sk_page_frag_refill(sk, pfrag)) {
2256                         rc = -ENOMEM;
2257                         goto out;
2258                 }
2259 
2260                 use = min_t(int, len, pfrag->size - pfrag->offset);
2261 
2262                 if (!sk_wmem_schedule(sk, use)) {
2263                         rc = -ENOMEM;
2264                         goto out;
2265                 }
2266 
2267                 sk_mem_charge(sk, use);
2268                 size += use;
2269                 orig_offset = pfrag->offset;
2270                 pfrag->offset += use;
2271 
2272                 sge = sg + sg_curr - 1;
2273                 if (sg_curr > first_coalesce && sg_page(sge) == pfrag->page &&
2274                     sge->offset + sge->length == orig_offset) {
2275                         sge->length += use;
2276                 } else {
2277                         sge = sg + sg_curr;
2278                         sg_unmark_end(sge);
2279                         sg_set_page(sge, pfrag->page, use, orig_offset);
2280                         get_page(pfrag->page);
2281                         sg_curr++;
2282 
2283                         if (sg_curr == MAX_SKB_FRAGS)
2284                                 sg_curr = 0;
2285 
2286                         if (sg_curr == sg_start) {
2287                                 rc = -ENOSPC;
2288                                 break;
2289                         }
2290                 }
2291 
2292                 len -= use;
2293         }
2294 out:
2295         *sg_curr_size = size;
2296         *sg_curr_index = sg_curr;
2297         return rc;
2298 }
2299 EXPORT_SYMBOL(sk_alloc_sg);
2300 
2301 static void __lock_sock(struct sock *sk)
2302         __releases(&sk->sk_lock.slock)
2303         __acquires(&sk->sk_lock.slock)
2304 {
2305         DEFINE_WAIT(wait);
2306 
2307         for (;;) {
2308                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2309                                         TASK_UNINTERRUPTIBLE);
2310                 spin_unlock_bh(&sk->sk_lock.slock);
2311                 schedule();
2312                 spin_lock_bh(&sk->sk_lock.slock);
2313                 if (!sock_owned_by_user(sk))
2314                         break;
2315         }
2316         finish_wait(&sk->sk_lock.wq, &wait);
2317 }
2318 
2319 static void __release_sock(struct sock *sk)
2320         __releases(&sk->sk_lock.slock)
2321         __acquires(&sk->sk_lock.slock)
2322 {
2323         struct sk_buff *skb, *next;
2324 
2325         while ((skb = sk->sk_backlog.head) != NULL) {
2326                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2327 
2328                 spin_unlock_bh(&sk->sk_lock.slock);
2329 
2330                 do {
2331                         next = skb->next;
2332                         prefetch(next);
2333                         WARN_ON_ONCE(skb_dst_is_noref(skb));
2334                         skb->next = NULL;
2335                         sk_backlog_rcv(sk, skb);
2336 
2337                         cond_resched();
2338 
2339                         skb = next;
2340                 } while (skb != NULL);
2341 
2342                 spin_lock_bh(&sk->sk_lock.slock);
2343         }
2344 
2345         /*
2346          * Doing the zeroing here guarantee we can not loop forever
2347          * while a wild producer attempts to flood us.
2348          */
2349         sk->sk_backlog.len = 0;
2350 }
2351 
2352 void __sk_flush_backlog(struct sock *sk)
2353 {
2354         spin_lock_bh(&sk->sk_lock.slock);
2355         __release_sock(sk);
2356         spin_unlock_bh(&sk->sk_lock.slock);
2357 }
2358 
2359 /**
2360  * sk_wait_data - wait for data to arrive at sk_receive_queue
2361  * @sk:    sock to wait on
2362  * @timeo: for how long
2363  * @skb:   last skb seen on sk_receive_queue
2364  *
2365  * Now socket state including sk->sk_err is changed only under lock,
2366  * hence we may omit checks after joining wait queue.
2367  * We check receive queue before schedule() only as optimization;
2368  * it is very likely that release_sock() added new data.
2369  */
2370 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2371 {
2372         DEFINE_WAIT_FUNC(wait, woken_wake_function);
2373         int rc;
2374 
2375         add_wait_queue(sk_sleep(sk), &wait);
2376         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2377         rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2378         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2379         remove_wait_queue(sk_sleep(sk), &wait);
2380         return rc;
2381 }
2382 EXPORT_SYMBOL(sk_wait_data);
2383 
2384 /**
2385  *      __sk_mem_raise_allocated - increase memory_allocated
2386  *      @sk: socket
2387  *      @size: memory size to allocate
2388  *      @amt: pages to allocate
2389  *      @kind: allocation type
2390  *
2391  *      Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2392  */
2393 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2394 {
2395         struct proto *prot = sk->sk_prot;
2396         long allocated = sk_memory_allocated_add(sk, amt);
2397 
2398         if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2399             !mem_cgroup_charge_skmem(sk->sk_memcg, amt))
2400                 goto suppress_allocation;
2401 
2402         /* Under limit. */
2403         if (allocated <= sk_prot_mem_limits(sk, 0)) {
2404                 sk_leave_memory_pressure(sk);
2405                 return 1;
2406         }
2407 
2408         /* Under pressure. */
2409         if (allocated > sk_prot_mem_limits(sk, 1))
2410                 sk_enter_memory_pressure(sk);
2411 
2412         /* Over hard limit. */
2413         if (allocated > sk_prot_mem_limits(sk, 2))
2414                 goto suppress_allocation;
2415 
2416         /* guarantee minimum buffer size under pressure */
2417         if (kind == SK_MEM_RECV) {
2418                 if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2419                         return 1;
2420 
2421         } else { /* SK_MEM_SEND */
2422                 int wmem0 = sk_get_wmem0(sk, prot);
2423 
2424                 if (sk->sk_type == SOCK_STREAM) {
2425                         if (sk->sk_wmem_queued < wmem0)
2426                                 return 1;
2427                 } else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2428                                 return 1;
2429                 }
2430         }
2431 
2432         if (sk_has_memory_pressure(sk)) {
2433                 int alloc;
2434 
2435                 if (!sk_under_memory_pressure(sk))
2436                         return 1;
2437                 alloc = sk_sockets_allocated_read_positive(sk);
2438                 if (sk_prot_mem_limits(sk, 2) > alloc *
2439                     sk_mem_pages(sk->sk_wmem_queued +
2440                                  atomic_read(&sk->sk_rmem_alloc) +
2441                                  sk->sk_forward_alloc))
2442                         return 1;
2443         }
2444 
2445 suppress_allocation:
2446 
2447         if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2448                 sk_stream_moderate_sndbuf(sk);
2449 
2450                 /* Fail only if socket is _under_ its sndbuf.
2451                  * In this case we cannot block, so that we have to fail.
2452                  */
2453                 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2454                         return 1;
2455         }
2456 
2457         trace_sock_exceed_buf_limit(sk, prot, allocated);
2458 
2459         sk_memory_allocated_sub(sk, amt);
2460 
2461         if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2462                 mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2463 
2464         return 0;
2465 }
2466 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2467 
2468 /**
2469  *      __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2470  *      @sk: socket
2471  *      @size: memory size to allocate
2472  *      @kind: allocation type
2473  *
2474  *      If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2475  *      rmem allocation. This function assumes that protocols which have
2476  *      memory_pressure use sk_wmem_queued as write buffer accounting.
2477  */
2478 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2479 {
2480         int ret, amt = sk_mem_pages(size);
2481 
2482         sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2483         ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2484         if (!ret)
2485                 sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2486         return ret;
2487 }
2488 EXPORT_SYMBOL(__sk_mem_schedule);
2489 
2490 /**
2491  *      __sk_mem_reduce_allocated - reclaim memory_allocated
2492  *      @sk: socket
2493  *      @amount: number of quanta
2494  *
2495  *      Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2496  */
2497 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2498 {
2499         sk_memory_allocated_sub(sk, amount);
2500 
2501         if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2502                 mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2503 
2504         if (sk_under_memory_pressure(sk) &&
2505             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2506                 sk_leave_memory_pressure(sk);
2507 }
2508 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2509 
2510 /**
2511  *      __sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2512  *      @sk: socket
2513  *      @amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2514  */
2515 void __sk_mem_reclaim(struct sock *sk, int amount)
2516 {
2517         amount >>= SK_MEM_QUANTUM_SHIFT;
2518         sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2519         __sk_mem_reduce_allocated(sk, amount);
2520 }
2521 EXPORT_SYMBOL(__sk_mem_reclaim);
2522 
2523 int sk_set_peek_off(struct sock *sk, int val)
2524 {
2525         sk->sk_peek_off = val;
2526         return 0;
2527 }
2528 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2529 
2530 /*
2531  * Set of default routines for initialising struct proto_ops when
2532  * the protocol does not support a particular function. In certain
2533  * cases where it makes no sense for a protocol to have a "do nothing"
2534  * function, some default processing is provided.
2535  */
2536 
2537 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2538 {
2539         return -EOPNOTSUPP;
2540 }
2541 EXPORT_SYMBOL(sock_no_bind);
2542 
2543 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2544                     int len, int flags)
2545 {
2546         return -EOPNOTSUPP;
2547 }
2548 EXPORT_SYMBOL(sock_no_connect);
2549 
2550 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2551 {
2552         return -EOPNOTSUPP;
2553 }
2554 EXPORT_SYMBOL(sock_no_socketpair);
2555 
2556 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2557                    bool kern)
2558 {
2559         return -EOPNOTSUPP;
2560 }
2561 EXPORT_SYMBOL(sock_no_accept);
2562 
2563 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2564                     int peer)
2565 {
2566         return -EOPNOTSUPP;
2567 }
2568 EXPORT_SYMBOL(sock_no_getname);
2569 
2570 __poll_t sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2571 {
2572         return 0;
2573 }
2574 EXPORT_SYMBOL(sock_no_poll);
2575 
2576 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2577 {
2578         return -EOPNOTSUPP;
2579 }
2580 EXPORT_SYMBOL(sock_no_ioctl);
2581 
2582 int sock_no_listen(struct socket *sock, int backlog)
2583 {
2584         return -EOPNOTSUPP;
2585 }
2586 EXPORT_SYMBOL(sock_no_listen);
2587 
2588 int sock_no_shutdown(struct socket *sock, int how)
2589 {
2590         return -EOPNOTSUPP;
2591 }
2592 EXPORT_SYMBOL(sock_no_shutdown);
2593 
2594 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2595                     char __user *optval, unsigned int optlen)
2596 {
2597         return -EOPNOTSUPP;
2598 }
2599 EXPORT_SYMBOL(sock_no_setsockopt);
2600 
2601 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2602                     char __user *optval, int __user *optlen)
2603 {
2604         return -EOPNOTSUPP;
2605 }
2606 EXPORT_SYMBOL(sock_no_getsockopt);
2607 
2608 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2609 {
2610         return -EOPNOTSUPP;
2611 }
2612 EXPORT_SYMBOL(sock_no_sendmsg);
2613 
2614 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2615 {
2616         return -EOPNOTSUPP;
2617 }
2618 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2619 
2620 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2621                     int flags)
2622 {
2623         return -EOPNOTSUPP;
2624 }
2625 EXPORT_SYMBOL(sock_no_recvmsg);
2626 
2627 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2628 {
2629         /* Mirror missing mmap method error code */
2630         return -ENODEV;
2631 }
2632 EXPORT_SYMBOL(sock_no_mmap);
2633 
2634 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2635 {
2636         ssize_t res;
2637         struct msghdr msg = {.msg_flags = flags};
2638         struct kvec iov;
2639         char *kaddr = kmap(page);
2640         iov.iov_base = kaddr + offset;
2641         iov.iov_len = size;
2642         res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2643         kunmap(page);
2644         return res;
2645 }
2646 EXPORT_SYMBOL(sock_no_sendpage);
2647 
2648 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2649                                 int offset, size_t size, int flags)
2650 {
2651         ssize_t res;
2652         struct msghdr msg = {.msg_flags = flags};
2653         struct kvec iov;
2654         char *kaddr = kmap(page);
2655 
2656         iov.iov_base = kaddr + offset;
2657         iov.iov_len = size;
2658         res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2659         kunmap(page);
2660         return res;
2661 }
2662 EXPORT_SYMBOL(sock_no_sendpage_locked);
2663 
2664 /*
2665  *      Default Socket Callbacks
2666  */
2667 
2668 static void sock_def_wakeup(struct sock *sk)
2669 {
2670         struct socket_wq *wq;
2671 
2672         rcu_read_lock();
2673         wq = rcu_dereference(sk->sk_wq);
2674         if (skwq_has_sleeper(wq))
2675                 wake_up_interruptible_all(&wq->wait);
2676         rcu_read_unlock();
2677 }
2678 
2679 static void sock_def_error_report(struct sock *sk)
2680 {
2681         struct socket_wq *wq;
2682 
2683         rcu_read_lock();
2684         wq = rcu_dereference(sk->sk_wq);
2685         if (skwq_has_sleeper(wq))
2686                 wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2687         sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2688         rcu_read_unlock();
2689 }
2690 
2691 static void sock_def_readable(struct sock *sk)
2692 {
2693         struct socket_wq *wq;
2694 
2695         rcu_read_lock();
2696         wq = rcu_dereference(sk->sk_wq);
2697         if (skwq_has_sleeper(wq))
2698                 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2699                                                 EPOLLRDNORM | EPOLLRDBAND);
2700         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2701         rcu_read_unlock();
2702 }
2703 
2704 static void sock_def_write_space(struct sock *sk)
2705 {
2706         struct socket_wq *wq;
2707 
2708         rcu_read_lock();
2709 
2710         /* Do not wake up a writer until he can make "significant"
2711          * progress.  --DaveM
2712          */
2713         if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2714                 wq = rcu_dereference(sk->sk_wq);
2715                 if (skwq_has_sleeper(wq))
2716                         wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2717                                                 EPOLLWRNORM | EPOLLWRBAND);
2718 
2719                 /* Should agree with poll, otherwise some programs break */
2720                 if (sock_writeable(sk))
2721                         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2722         }
2723 
2724         rcu_read_unlock();
2725 }
2726 
2727 static void sock_def_destruct(struct sock *sk)
2728 {
2729 }
2730 
2731 void sk_send_sigurg(struct sock *sk)
2732 {
2733         if (sk->sk_socket && sk->sk_socket->file)
2734                 if (send_sigurg(&sk->sk_socket->file->f_owner))
2735                         sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2736 }
2737 EXPORT_SYMBOL(sk_send_sigurg);
2738 
2739 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2740                     unsigned long expires)
2741 {
2742         if (!mod_timer(timer, expires))
2743                 sock_hold(sk);
2744 }
2745 EXPORT_SYMBOL(sk_reset_timer);
2746 
2747 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2748 {
2749         if (del_timer(timer))
2750                 __sock_put(sk);
2751 }
2752 EXPORT_SYMBOL(sk_stop_timer);
2753 
2754 void sock_init_data(struct socket *sock, struct sock *sk)
2755 {
2756         sk_init_common(sk);
2757         sk->sk_send_head        =       NULL;
2758 
2759         timer_setup(&sk->sk_timer, NULL, 0);
2760 
2761         sk->sk_allocation       =       GFP_KERNEL;
2762         sk->sk_rcvbuf           =       sysctl_rmem_default;
2763         sk->sk_sndbuf           =       sysctl_wmem_default;
2764         sk->sk_state            =       TCP_CLOSE;
2765         sk_set_socket(sk, sock);
2766 
2767         sock_set_flag(sk, SOCK_ZAPPED);
2768 
2769         if (sock) {
2770                 sk->sk_type     =       sock->type;
2771                 sk->sk_wq       =       sock->wq;
2772                 sock->sk        =       sk;
2773                 sk->sk_uid      =       SOCK_INODE(sock)->i_uid;
2774         } else {
2775                 sk->sk_wq       =       NULL;
2776                 sk->sk_uid      =       make_kuid(sock_net(sk)->user_ns, 0);
2777         }
2778 
2779         rwlock_init(&sk->sk_callback_lock);
2780         if (sk->sk_kern_sock)
2781                 lockdep_set_class_and_name(
2782                         &sk->sk_callback_lock,
2783                         af_kern_callback_keys + sk->sk_family,
2784                         af_family_kern_clock_key_strings[sk->sk_family]);
2785         else
2786                 lockdep_set_class_and_name(
2787                         &sk->sk_callback_lock,
2788                         af_callback_keys + sk->sk_family,
2789                         af_family_clock_key_strings[sk->sk_family]);
2790 
2791         sk->sk_state_change     =       sock_def_wakeup;
2792         sk->sk_data_ready       =       sock_def_readable;
2793         sk->sk_write_space      =       sock_def_write_space;
2794         sk->sk_error_report     =       sock_def_error_report;
2795         sk->sk_destruct         =       sock_def_destruct;
2796 
2797         sk->sk_frag.page        =       NULL;
2798         sk->sk_frag.offset      =       0;
2799         sk->sk_peek_off         =       -1;
2800 
2801         sk->sk_peer_pid         =       NULL;
2802         sk->sk_peer_cred        =       NULL;
2803         sk->sk_write_pending    =       0;
2804         sk->sk_rcvlowat         =       1;
2805         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
2806         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
2807 
2808         sk->sk_stamp = SK_DEFAULT_STAMP;
2809         atomic_set(&sk->sk_zckey, 0);
2810 
2811 #ifdef CONFIG_NET_RX_BUSY_POLL
2812         sk->sk_napi_id          =       0;
2813         sk->sk_ll_usec          =       sysctl_net_busy_read;
2814 #endif
2815 
2816         sk->sk_max_pacing_rate = ~0U;
2817         sk->sk_pacing_rate = ~0U;
2818         sk->sk_pacing_shift = 10;
2819         sk->sk_incoming_cpu = -1;
2820         /*
2821          * Before updating sk_refcnt, we must commit prior changes to memory
2822          * (Documentation/RCU/rculist_nulls.txt for details)
2823          */
2824         smp_wmb();
2825         refcount_set(&sk->sk_refcnt, 1);
2826         atomic_set(&sk->sk_drops, 0);
2827 }
2828 EXPORT_SYMBOL(sock_init_data);
2829 
2830 void lock_sock_nested(struct sock *sk, int subclass)
2831 {
2832         might_sleep();
2833         spin_lock_bh(&sk->sk_lock.slock);
2834         if (sk->sk_lock.owned)
2835                 __lock_sock(sk);
2836         sk->sk_lock.owned = 1;
2837         spin_unlock(&sk->sk_lock.slock);
2838         /*
2839          * The sk_lock has mutex_lock() semantics here:
2840          */
2841         mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2842         local_bh_enable();
2843 }
2844 EXPORT_SYMBOL(lock_sock_nested);
2845 
2846 void release_sock(struct sock *sk)
2847 {
2848         spin_lock_bh(&sk->sk_lock.slock);
2849         if (sk->sk_backlog.tail)
2850                 __release_sock(sk);
2851 
2852         /* Warning : release_cb() might need to release sk ownership,
2853          * ie call sock_release_ownership(sk) before us.
2854          */
2855         if (sk->sk_prot->release_cb)
2856                 sk->sk_prot->release_cb(sk);
2857 
2858         sock_release_ownership(sk);
2859         if (waitqueue_active(&sk->sk_lock.wq))
2860                 wake_up(&sk->sk_lock.wq);
2861         spin_unlock_bh(&sk->sk_lock.slock);
2862 }
2863 EXPORT_SYMBOL(release_sock);
2864 
2865 /**
2866  * lock_sock_fast - fast version of lock_sock
2867  * @sk: socket
2868  *
2869  * This version should be used for very small section, where process wont block
2870  * return false if fast path is taken:
2871  *
2872  *   sk_lock.slock locked, owned = 0, BH disabled
2873  *
2874  * return true if slow path is taken:
2875  *
2876  *   sk_lock.slock unlocked, owned = 1, BH enabled
2877  */
2878 bool lock_sock_fast(struct sock *sk)
2879 {
2880         might_sleep();
2881         spin_lock_bh(&sk->sk_lock.slock);
2882 
2883         if (!sk->sk_lock.owned)
2884                 /*
2885                  * Note : We must disable BH
2886                  */
2887                 return false;
2888 
2889         __lock_sock(sk);
2890         sk->sk_lock.owned = 1;
2891         spin_unlock(&sk->sk_lock.slock);
2892         /*
2893          * The sk_lock has mutex_lock() semantics here:
2894          */
2895         mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2896         local_bh_enable();
2897         return true;
2898 }
2899 EXPORT_SYMBOL(lock_sock_fast);
2900 
2901 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2902 {
2903         struct timeval tv;
2904         if (!sock_flag(sk, SOCK_TIMESTAMP))
2905                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2906         tv = ktime_to_timeval(sk->sk_stamp);
2907         if (tv.tv_sec == -1)
2908                 return -ENOENT;
2909         if (tv.tv_sec == 0) {
2910                 sk->sk_stamp = ktime_get_real();
2911                 tv = ktime_to_timeval(sk->sk_stamp);
2912         }
2913         return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2914 }
2915 EXPORT_SYMBOL(sock_get_timestamp);
2916 
2917 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2918 {
2919         struct timespec ts;
2920         if (!sock_flag(sk, SOCK_TIMESTAMP))
2921                 sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2922         ts = ktime_to_timespec(sk->sk_stamp);
2923         if (ts.tv_sec == -1)
2924                 return -ENOENT;
2925         if (ts.tv_sec == 0) {
2926                 sk->sk_stamp = ktime_get_real();
2927                 ts = ktime_to_timespec(sk->sk_stamp);
2928         }
2929         return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2930 }
2931 EXPORT_SYMBOL(sock_get_timestampns);
2932 
2933 void sock_enable_timestamp(struct sock *sk, int flag)
2934 {
2935         if (!sock_flag(sk, flag)) {
2936                 unsigned long previous_flags = sk->sk_flags;
2937 
2938                 sock_set_flag(sk, flag);
2939                 /*
2940                  * we just set one of the two flags which require net
2941                  * time stamping, but time stamping might have been on
2942                  * already because of the other one
2943                  */
2944                 if (sock_needs_netstamp(sk) &&
2945                     !(previous_flags & SK_FLAGS_TIMESTAMP))
2946                         net_enable_timestamp();
2947         }
2948 }
2949 
2950 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2951                        int level, int type)
2952 {
2953         struct sock_exterr_skb *serr;
2954         struct sk_buff *skb;
2955         int copied, err;
2956 
2957         err = -EAGAIN;
2958         skb = sock_dequeue_err_skb(sk);
2959         if (skb == NULL)
2960                 goto out;
2961 
2962         copied = skb->len;
2963         if (copied > len) {
2964                 msg->msg_flags |= MSG_TRUNC;
2965                 copied = len;
2966         }
2967         err = skb_copy_datagram_msg(skb, 0, msg, copied);
2968         if (err)
2969                 goto out_free_skb;
2970 
2971         sock_recv_timestamp(msg, sk, skb);
2972 
2973         serr = SKB_EXT_ERR(skb);
2974         put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2975 
2976         msg->msg_flags |= MSG_ERRQUEUE;
2977         err = copied;
2978 
2979 out_free_skb:
2980         kfree_skb(skb);
2981 out:
2982         return err;
2983 }
2984 EXPORT_SYMBOL(sock_recv_errqueue);
2985 
2986 /*
2987  *      Get a socket option on an socket.
2988  *
2989  *      FIX: POSIX 1003.1g is very ambiguous here. It states that
2990  *      asynchronous errors should be reported by getsockopt. We assume
2991  *      this means if you specify SO_ERROR (otherwise whats the point of it).
2992  */
2993 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2994                            char __user *optval, int __user *optlen)
2995 {
2996         struct sock *sk = sock->sk;
2997 
2998         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2999 }
3000 EXPORT_SYMBOL(sock_common_getsockopt);
3001 
3002 #ifdef CONFIG_COMPAT
3003 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3004                                   char __user *optval, int __user *optlen)
3005 {
3006         struct sock *sk = sock->sk;
3007 
3008         if (sk->sk_prot->compat_getsockopt != NULL)
3009                 return sk->sk_prot->compat_getsockopt(sk, level, optname,
3010                                                       optval, optlen);
3011         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3012 }
3013 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3014 #endif
3015 
3016 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3017                         int flags)
3018 {
3019         struct sock *sk = sock->sk;
3020         int addr_len = 0;
3021         int err;
3022 
3023         err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3024                                    flags & ~MSG_DONTWAIT, &addr_len);
3025         if (err >= 0)
3026                 msg->msg_namelen = addr_len;
3027         return err;
3028 }
3029 EXPORT_SYMBOL(sock_common_recvmsg);
3030 
3031 /*
3032  *      Set socket options on an inet socket.
3033  */
3034 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3035                            char __user *optval, unsigned int optlen)
3036 {
3037         struct sock *sk = sock->sk;
3038 
3039         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3040 }
3041 EXPORT_SYMBOL(sock_common_setsockopt);
3042 
3043 #ifdef CONFIG_COMPAT
3044 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3045                                   char __user *optval, unsigned int optlen)
3046 {
3047         struct sock *sk = sock->sk;
3048 
3049         if (sk->sk_prot->compat_setsockopt != NULL)
3050                 return sk->sk_prot->compat_setsockopt(sk, level, optname,
3051                                                       optval, optlen);
3052         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3053 }
3054 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3055 #endif
3056 
3057 void sk_common_release(struct sock *sk)
3058 {
3059         if (sk->sk_prot->destroy)
3060                 sk->sk_prot->destroy(sk);
3061 
3062         /*
3063          * Observation: when sock_common_release is called, processes have
3064          * no access to socket. But net still has.
3065          * Step one, detach it from networking:
3066          *
3067          * A. Remove from hash tables.
3068          */
3069 
3070         sk->sk_prot->unhash(sk);
3071 
3072         /*
3073          * In this point socket cannot receive new packets, but it is possible
3074          * that some packets are in flight because some CPU runs receiver and
3075          * did hash table lookup before we unhashed socket. They will achieve
3076          * receive queue and will be purged by socket destructor.
3077          *
3078          * Also we still have packets pending on receive queue and probably,
3079          * our own packets waiting in device queues. sock_destroy will drain
3080          * receive queue, but transmitted packets will delay socket destruction
3081          * until the last reference will be released.
3082          */
3083 
3084         sock_orphan(sk);
3085 
3086         xfrm_sk_free_policy(sk);
3087 
3088         sk_refcnt_debug_release(sk);
3089 
3090         sock_put(sk);
3091 }
3092 EXPORT_SYMBOL(sk_common_release);
3093 
3094 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3095 {
3096         memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3097 
3098         mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3099         mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
3100         mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3101         mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
3102         mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3103         mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
3104         mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3105         mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
3106         mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3107 }
3108 
3109 #ifdef CONFIG_PROC_FS
3110 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
3111 struct prot_inuse {
3112         int val[PROTO_INUSE_NR];
3113 };
3114 
3115 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3116 
3117 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3118 {
3119         __this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3120 }
3121 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3122 
3123 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3124 {
3125         int cpu, idx = prot->inuse_idx;
3126         int res = 0;
3127 
3128         for_each_possible_cpu(cpu)
3129                 res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3130 
3131         return res >= 0 ? res : 0;
3132 }
3133 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3134 
3135 static void sock_inuse_add(struct net *net, int val)
3136 {
3137         this_cpu_add(*net->core.sock_inuse, val);
3138 }
3139 
3140 int sock_inuse_get(struct net *net)
3141 {
3142         int cpu, res = 0;
3143 
3144         for_each_possible_cpu(cpu)
3145                 res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3146 
3147         return res;
3148 }
3149 
3150 EXPORT_SYMBOL_GPL(sock_inuse_get);
3151 
3152 static int __net_init sock_inuse_init_net(struct net *net)
3153 {
3154         net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3155         if (net->core.prot_inuse == NULL)
3156                 return -ENOMEM;
3157 
3158         net->core.sock_inuse = alloc_percpu(int);
3159         if (net->core.sock_inuse == NULL)
3160                 goto out;
3161 
3162         return 0;
3163 
3164 out:
3165         free_percpu(net->core.prot_inuse);
3166         return -ENOMEM;
3167 }
3168 
3169 static void __net_exit sock_inuse_exit_net(struct net *net)
3170 {
3171         free_percpu(net->core.prot_inuse);
3172         free_percpu(net->core.sock_inuse);
3173 }
3174 
3175 static struct pernet_operations net_inuse_ops = {
3176         .init = sock_inuse_init_net,
3177         .exit = sock_inuse_exit_net,
3178 };
3179 
3180 static __init int net_inuse_init(void)
3181 {
3182         if (register_pernet_subsys(&net_inuse_ops))
3183                 panic("Cannot initialize net inuse counters");
3184 
3185         return 0;
3186 }
3187 
3188 core_initcall(net_inuse_init);
3189 
3190 static void assign_proto_idx(struct proto *prot)
3191 {
3192         prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3193 
3194         if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3195                 pr_err("PROTO_INUSE_NR exhausted\n");
3196                 return;
3197         }
3198 
3199         set_bit(prot->inuse_idx, proto_inuse_idx);
3200 }
3201 
3202 static void release_proto_idx(struct proto *prot)
3203 {
3204         if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3205                 clear_bit(prot->inuse_idx, proto_inuse_idx);
3206 }
3207 #else
3208 static inline void assign_proto_idx(struct proto *prot)
3209 {
3210 }
3211 
3212 static inline void release_proto_idx(struct proto *prot)
3213 {
3214 }
3215 
3216 static void sock_inuse_add(struct net *net, int val)
3217 {
3218 }
3219 #endif
3220 
3221 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3222 {
3223         if (!rsk_prot)
3224                 return;
3225         kfree(rsk_prot->slab_name);
3226         rsk_prot->slab_name = NULL;
3227         kmem_cache_destroy(rsk_prot->slab);
3228         rsk_prot->slab = NULL;
3229 }
3230 
3231 static int req_prot_init(const struct proto *prot)
3232 {
3233         struct request_sock_ops *rsk_prot = prot->rsk_prot;
3234 
3235         if (!rsk_prot)
3236                 return 0;
3237 
3238         rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3239                                         prot->name);
3240         if (!rsk_prot->slab_name)
3241                 return -ENOMEM;
3242 
3243         rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3244                                            rsk_prot->obj_size, 0,
3245                                            prot->slab_flags, NULL);
3246 
3247         if (!rsk_prot->slab) {
3248                 pr_crit("%s: Can't create request sock SLAB cache!\n",
3249                         prot->name);
3250                 return -ENOMEM;
3251         }
3252         return 0;
3253 }
3254 
3255 int proto_register(struct proto *prot, int alloc_slab)
3256 {
3257         if (alloc_slab) {
3258                 prot->slab = kmem_cache_create_usercopy(prot->name,
3259                                         prot->obj_size, 0,
3260                                         SLAB_HWCACHE_ALIGN | prot->slab_flags,
3261                                         prot->useroffset, prot->usersize,
3262                                         NULL);
3263 
3264                 if (prot->slab == NULL) {
3265                         pr_crit("%s: Can't create sock SLAB cache!\n",
3266                                 prot->name);
3267                         goto out;
3268                 }
3269 
3270                 if (req_prot_init(prot))
3271                         goto out_free_request_sock_slab;
3272 
3273                 if (prot->twsk_prot != NULL) {
3274                         prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3275 
3276                         if (prot->twsk_prot->twsk_slab_name == NULL)
3277                                 goto out_free_request_sock_slab;
3278 
3279                         prot->twsk_prot->twsk_slab =
3280                                 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3281                                                   prot->twsk_prot->twsk_obj_size,
3282                                                   0,
3283                                                   prot->slab_flags,
3284                                                   NULL);
3285                         if (prot->twsk_prot->twsk_slab == NULL)
3286                                 goto out_free_timewait_sock_slab_name;
3287                 }
3288         }
3289 
3290         mutex_lock(&proto_list_mutex);
3291         list_add(&prot->node, &proto_list);
3292         assign_proto_idx(prot);
3293         mutex_unlock(&proto_list_mutex);
3294         return 0;
3295 
3296 out_free_timewait_sock_slab_name:
3297         kfree(prot->twsk_prot->twsk_slab_name);
3298 out_free_request_sock_slab:
3299         req_prot_cleanup(prot->rsk_prot);
3300 
3301         kmem_cache_destroy(prot->slab);
3302         prot->slab = NULL;
3303 out:
3304         return -ENOBUFS;
3305 }
3306 EXPORT_SYMBOL(proto_register);
3307 
3308 void proto_unregister(struct proto *prot)
3309 {
3310         mutex_lock(&proto_list_mutex);
3311         release_proto_idx(prot);
3312         list_del(&prot->node);
3313         mutex_unlock(&proto_list_mutex);
3314 
3315         kmem_cache_destroy(prot->slab);
3316         prot->slab = NULL;
3317 
3318         req_prot_cleanup(prot->rsk_prot);
3319 
3320         if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3321                 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3322                 kfree(prot->twsk_prot->twsk_slab_name);
3323                 prot->twsk_prot->twsk_slab = NULL;
3324         }
3325 }
3326 EXPORT_SYMBOL(proto_unregister);
3327 
3328 int sock_load_diag_module(int family, int protocol)
3329 {
3330         if (!protocol) {
3331                 if (!sock_is_registered(family))
3332                         return -ENOENT;
3333 
3334                 return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3335                                       NETLINK_SOCK_DIAG, family);
3336         }
3337 
3338 #ifdef CONFIG_INET
3339         if (family == AF_INET &&
3340             !rcu_access_pointer(inet_protos[protocol]))
3341                 return -ENOENT;
3342 #endif
3343 
3344         return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3345                               NETLINK_SOCK_DIAG, family, protocol);
3346 }
3347 EXPORT_SYMBOL(sock_load_diag_module);
3348 
3349 #ifdef CONFIG_PROC_FS
3350 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3351         __acquires(proto_list_mutex)
3352 {
3353         mutex_lock(&proto_list_mutex);
3354         return seq_list_start_head(&proto_list, *pos);
3355 }
3356 
3357 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3358 {
3359         return seq_list_next(v, &proto_list, pos);
3360 }
3361 
3362 static void proto_seq_stop(struct seq_file *seq, void *v)
3363         __releases(proto_list_mutex)
3364 {
3365         mutex_unlock(&proto_list_mutex);
3366 }
3367 
3368 static char proto_method_implemented(const void *method)
3369 {
3370         return method == NULL ? 'n' : 'y';
3371 }
3372 static long sock_prot_memory_allocated(struct proto *proto)
3373 {
3374         return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3375 }
3376 
3377 static char *sock_prot_memory_pressure(struct proto *proto)
3378 {
3379         return proto->memory_pressure != NULL ?
3380         proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3381 }
3382 
3383 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3384 {
3385 
3386         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3387                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3388                    proto->name,
3389                    proto->obj_size,
3390                    sock_prot_inuse_get(seq_file_net(seq), proto),
3391                    sock_prot_memory_allocated(proto),
3392                    sock_prot_memory_pressure(proto),
3393                    proto->max_header,
3394                    proto->slab == NULL ? "no" : "yes",
3395                    module_name(proto->owner),
3396                    proto_method_implemented(proto->close),
3397                    proto_method_implemented(proto->connect),
3398                    proto_method_implemented(proto->disconnect),
3399                    proto_method_implemented(proto->accept),
3400                    proto_method_implemented(proto->ioctl),
3401                    proto_method_implemented(proto->init),
3402                    proto_method_implemented(proto->destroy),
3403                    proto_method_implemented(proto->shutdown),
3404                    proto_method_implemented(proto->setsockopt),
3405                    proto_method_implemented(proto->getsockopt),
3406                    proto_method_implemented(proto->sendmsg),
3407                    proto_method_implemented(proto->recvmsg),
3408                    proto_method_implemented(proto->sendpage),
3409                    proto_method_implemented(proto->bind),
3410                    proto_method_implemented(proto->backlog_rcv),
3411                    proto_method_implemented(proto->hash),
3412                    proto_method_implemented(proto->unhash),
3413                    proto_method_implemented(proto->get_port),
3414                    proto_method_implemented(proto->enter_memory_pressure));
3415 }
3416 
3417 static int proto_seq_show(struct seq_file *seq, void *v)
3418 {
3419         if (v == &proto_list)
3420                 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3421                            "protocol",
3422                            "size",
3423                            "sockets",
3424                            "memory",
3425                            "press",
3426                            "maxhdr",
3427                            "slab",
3428                            "module",
3429                            "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3430         else
3431                 proto_seq_printf(seq, list_entry(v, struct proto, node));
3432         return 0;
3433 }
3434 
3435 static const struct seq_operations proto_seq_ops = {
3436         .start  = proto_seq_start,
3437         .next   = proto_seq_next,
3438         .stop   = proto_seq_stop,
3439         .show   = proto_seq_show,
3440 };
3441 
3442 static int proto_seq_open(struct inode *inode, struct file *file)
3443 {
3444         return seq_open_net(inode, file, &proto_seq_ops,
3445                             sizeof(struct seq_net_private));
3446 }
3447 
3448 static const struct file_operations proto_seq_fops = {
3449         .open           = proto_seq_open,
3450         .read           = seq_read,
3451         .llseek         = seq_lseek,
3452         .release        = seq_release_net,
3453 };
3454 
3455 static __net_init int proto_init_net(struct net *net)
3456 {
3457         if (!proc_create("protocols", 0444, net->proc_net, &proto_seq_fops))
3458                 return -ENOMEM;
3459 
3460         return 0;
3461 }
3462 
3463 static __net_exit void proto_exit_net(struct net *net)
3464 {
3465         remove_proc_entry("protocols", net->proc_net);
3466 }
3467 
3468 
3469 static __net_initdata struct pernet_operations proto_net_ops = {
3470         .init = proto_init_net,
3471         .exit = proto_exit_net,
3472 };
3473 
3474 static int __init proto_init(void)
3475 {
3476         return register_pernet_subsys(&proto_net_ops);
3477 }
3478 
3479 subsys_initcall(proto_init);
3480 
3481 #endif /* PROC_FS */
3482 
3483 #ifdef CONFIG_NET_RX_BUSY_POLL
3484 bool sk_busy_loop_end(void *p, unsigned long start_time)
3485 {
3486         struct sock *sk = p;
3487 
3488         return !skb_queue_empty(&sk->sk_receive_queue) ||
3489                sk_busy_loop_timeout(sk, start_time);
3490 }
3491 EXPORT_SYMBOL(sk_busy_loop_end);
3492 #endif /* CONFIG_NET_RX_BUSY_POLL */
3493 

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