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

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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
  4  *              operating system.  INET is implemented using the  BSD Socket
  5  *              interface as the means of communication with the user level.
  6  *
  7  *              Generic socket support routines. Memory allocators, socket lock/release
  8  *              handler for protocols to use and generic option handler.
  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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 87 
 88 #include <asm/unaligned.h>
 89 #include <linux/capability.h>
 90 #include <linux/errno.h>
 91 #include <linux/errqueue.h>
 92 #include <linux/types.h>
 93 #include <linux/socket.h>
 94 #include <linux/in.h>
 95 #include <linux/kernel.h>
 96 #include <linux/module.h>
 97 #include <linux/proc_fs.h>
 98 #include <linux/seq_file.h>
 99 #include <linux/sched.h>
100 #include <linux/sched/mm.h>
101 #include <linux/timer.h>
102 #include <linux/string.h>
103 #include <linux/sockios.h>
104 #include <linux/net.h>
105 #include <linux/mm.h>
106 #include <linux/slab.h>
107 #include <linux/interrupt.h>
108 #include <linux/poll.h>
109 #include <linux/tcp.h>
110 #include <linux/init.h>
111 #include <linux/highmem.h>
112 #include <linux/user_namespace.h>
113 #include <linux/static_key.h>
114 #include <linux/memcontrol.h>
115 #include <linux/prefetch.h>
116 
117 #include <linux/uaccess.h>
118 
119 #include <linux/netdevice.h>
120 #include <net/protocol.h>
121 #include <linux/skbuff.h>
122 #include <net/net_namespace.h>
123 #include <net/request_sock.h>
124 #include <net/sock.h>
125 #include <linux/net_tstamp.h>
126 #include <net/xfrm.h>
127 #include <linux/ipsec.h>
128 #include <net/cls_cgroup.h>
129 #include <net/netprio_cgroup.h>
130 #include <linux/sock_diag.h>
131 
132 #include <linux/filter.h>
133 #include <net/sock_reuseport.h>
134 #include <net/bpf_sk_storage.h>
135 
136 #include <trace/events/sock.h>
137 
138 #include <net/tcp.h>
139 #include <net/busy_poll.h>
140 
141 static DEFINE_MUTEX(proto_list_mutex);
142 static LIST_HEAD(proto_list);
143 
144 static void sock_inuse_add(struct net *net, int val);
145 
146 /**
147  * sk_ns_capable - General socket capability test
148  * @sk: Socket to use a capability on or through
149  * @user_ns: The user namespace of the capability to use
150  * @cap: The capability to use
151  *
152  * Test to see if the opener of the socket had when the socket was
153  * created and the current process has the capability @cap in the user
154  * namespace @user_ns.
155  */
156 bool sk_ns_capable(const struct sock *sk,
157                    struct user_namespace *user_ns, int cap)
158 {
159         return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
160                 ns_capable(user_ns, cap);
161 }
162 EXPORT_SYMBOL(sk_ns_capable);
163 
164 /**
165  * sk_capable - Socket global capability test
166  * @sk: Socket to use a capability on or through
167  * @cap: The global capability to use
168  *
169  * Test to see if the opener of the socket had when the socket was
170  * created and the current process has the capability @cap in all user
171  * namespaces.
172  */
173 bool sk_capable(const struct sock *sk, int cap)
174 {
175         return sk_ns_capable(sk, &init_user_ns, cap);
176 }
177 EXPORT_SYMBOL(sk_capable);
178 
179 /**
180  * sk_net_capable - Network namespace socket capability test
181  * @sk: Socket to use a capability on or through
182  * @cap: The capability to use
183  *
184  * Test to see if the opener of the socket had when the socket was created
185  * and the current process has the capability @cap over the network namespace
186  * the socket is a member of.
187  */
188 bool sk_net_capable(const struct sock *sk, int cap)
189 {
190         return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
191 }
192 EXPORT_SYMBOL(sk_net_capable);
193 
194 /*
195  * Each address family might have different locking rules, so we have
196  * one slock key per address family and separate keys for internal and
197  * userspace sockets.
198  */
199 static struct lock_class_key af_family_keys[AF_MAX];
200 static struct lock_class_key af_family_kern_keys[AF_MAX];
201 static struct lock_class_key af_family_slock_keys[AF_MAX];
202 static struct lock_class_key af_family_kern_slock_keys[AF_MAX];
203 
204 /*
205  * Make lock validator output more readable. (we pre-construct these
206  * strings build-time, so that runtime initialization of socket
207  * locks is fast):
208  */
209 
210 #define _sock_locks(x)                                            \
211   x "AF_UNSPEC",        x "AF_UNIX"     ,       x "AF_INET"     , \
212   x "AF_AX25"  ,        x "AF_IPX"      ,       x "AF_APPLETALK", \
213   x "AF_NETROM",        x "AF_BRIDGE"   ,       x "AF_ATMPVC"   , \
214   x "AF_X25"   ,        x "AF_INET6"    ,       x "AF_ROSE"     , \
215   x "AF_DECnet",        x "AF_NETBEUI"  ,       x "AF_SECURITY" , \
216   x "AF_KEY"   ,        x "AF_NETLINK"  ,       x "AF_PACKET"   , \
217   x "AF_ASH"   ,        x "AF_ECONET"   ,       x "AF_ATMSVC"   , \
218   x "AF_RDS"   ,        x "AF_SNA"      ,       x "AF_IRDA"     , \
219   x "AF_PPPOX" ,        x "AF_WANPIPE"  ,       x "AF_LLC"      , \
220   x "27"       ,        x "28"          ,       x "AF_CAN"      , \
221   x "AF_TIPC"  ,        x "AF_BLUETOOTH",       x "IUCV"        , \
222   x "AF_RXRPC" ,        x "AF_ISDN"     ,       x "AF_PHONET"   , \
223   x "AF_IEEE802154",    x "AF_CAIF"     ,       x "AF_ALG"      , \
224   x "AF_NFC"   ,        x "AF_VSOCK"    ,       x "AF_KCM"      , \
225   x "AF_QIPCRTR",       x "AF_SMC"      ,       x "AF_XDP"      , \
226   x "AF_MAX"
227 
228 static const char *const af_family_key_strings[AF_MAX+1] = {
229         _sock_locks("sk_lock-")
230 };
231 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
232         _sock_locks("slock-")
233 };
234 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
235         _sock_locks("clock-")
236 };
237 
238 static const char *const af_family_kern_key_strings[AF_MAX+1] = {
239         _sock_locks("k-sk_lock-")
240 };
241 static const char *const af_family_kern_slock_key_strings[AF_MAX+1] = {
242         _sock_locks("k-slock-")
243 };
244 static const char *const af_family_kern_clock_key_strings[AF_MAX+1] = {
245         _sock_locks("k-clock-")
246 };
247 static const char *const af_family_rlock_key_strings[AF_MAX+1] = {
248         _sock_locks("rlock-")
249 };
250 static const char *const af_family_wlock_key_strings[AF_MAX+1] = {
251         _sock_locks("wlock-")
252 };
253 static const char *const af_family_elock_key_strings[AF_MAX+1] = {
254         _sock_locks("elock-")
255 };
256 
257 /*
258  * sk_callback_lock and sk queues locking rules are per-address-family,
259  * so split the lock classes by using a per-AF key:
260  */
261 static struct lock_class_key af_callback_keys[AF_MAX];
262 static struct lock_class_key af_rlock_keys[AF_MAX];
263 static struct lock_class_key af_wlock_keys[AF_MAX];
264 static struct lock_class_key af_elock_keys[AF_MAX];
265 static struct lock_class_key af_kern_callback_keys[AF_MAX];
266 
267 /* Run time adjustable parameters. */
268 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
269 EXPORT_SYMBOL(sysctl_wmem_max);
270 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
271 EXPORT_SYMBOL(sysctl_rmem_max);
272 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
273 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
274 
275 /* Maximal space eaten by iovec or ancillary data plus some space */
276 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
277 EXPORT_SYMBOL(sysctl_optmem_max);
278 
279 int sysctl_tstamp_allow_data __read_mostly = 1;
280 
281 DEFINE_STATIC_KEY_FALSE(memalloc_socks_key);
282 EXPORT_SYMBOL_GPL(memalloc_socks_key);
283 
284 /**
285  * sk_set_memalloc - sets %SOCK_MEMALLOC
286  * @sk: socket to set it on
287  *
288  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
289  * It's the responsibility of the admin to adjust min_free_kbytes
290  * to meet the requirements
291  */
292 void sk_set_memalloc(struct sock *sk)
293 {
294         sock_set_flag(sk, SOCK_MEMALLOC);
295         sk->sk_allocation |= __GFP_MEMALLOC;
296         static_branch_inc(&memalloc_socks_key);
297 }
298 EXPORT_SYMBOL_GPL(sk_set_memalloc);
299 
300 void sk_clear_memalloc(struct sock *sk)
301 {
302         sock_reset_flag(sk, SOCK_MEMALLOC);
303         sk->sk_allocation &= ~__GFP_MEMALLOC;
304         static_branch_dec(&memalloc_socks_key);
305 
306         /*
307          * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
308          * progress of swapping. SOCK_MEMALLOC may be cleared while
309          * it has rmem allocations due to the last swapfile being deactivated
310          * but there is a risk that the socket is unusable due to exceeding
311          * the rmem limits. Reclaim the reserves and obey rmem limits again.
312          */
313         sk_mem_reclaim(sk);
314 }
315 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
316 
317 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
318 {
319         int ret;
320         unsigned int noreclaim_flag;
321 
322         /* these should have been dropped before queueing */
323         BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
324 
325         noreclaim_flag = memalloc_noreclaim_save();
326         ret = sk->sk_backlog_rcv(sk, skb);
327         memalloc_noreclaim_restore(noreclaim_flag);
328 
329         return ret;
330 }
331 EXPORT_SYMBOL(__sk_backlog_rcv);
332 
333 static int sock_get_timeout(long timeo, void *optval, bool old_timeval)
334 {
335         struct __kernel_sock_timeval tv;
336         int size;
337 
338         if (timeo == MAX_SCHEDULE_TIMEOUT) {
339                 tv.tv_sec = 0;
340                 tv.tv_usec = 0;
341         } else {
342                 tv.tv_sec = timeo / HZ;
343                 tv.tv_usec = ((timeo % HZ) * USEC_PER_SEC) / HZ;
344         }
345 
346         if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
347                 struct old_timeval32 tv32 = { tv.tv_sec, tv.tv_usec };
348                 *(struct old_timeval32 *)optval = tv32;
349                 return sizeof(tv32);
350         }
351 
352         if (old_timeval) {
353                 struct __kernel_old_timeval old_tv;
354                 old_tv.tv_sec = tv.tv_sec;
355                 old_tv.tv_usec = tv.tv_usec;
356                 *(struct __kernel_old_timeval *)optval = old_tv;
357                 size = sizeof(old_tv);
358         } else {
359                 *(struct __kernel_sock_timeval *)optval = tv;
360                 size = sizeof(tv);
361         }
362 
363         return size;
364 }
365 
366 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen, bool old_timeval)
367 {
368         struct __kernel_sock_timeval tv;
369 
370         if (old_timeval && in_compat_syscall() && !COMPAT_USE_64BIT_TIME) {
371                 struct old_timeval32 tv32;
372 
373                 if (optlen < sizeof(tv32))
374                         return -EINVAL;
375 
376                 if (copy_from_user(&tv32, optval, sizeof(tv32)))
377                         return -EFAULT;
378                 tv.tv_sec = tv32.tv_sec;
379                 tv.tv_usec = tv32.tv_usec;
380         } else if (old_timeval) {
381                 struct __kernel_old_timeval old_tv;
382 
383                 if (optlen < sizeof(old_tv))
384                         return -EINVAL;
385                 if (copy_from_user(&old_tv, optval, sizeof(old_tv)))
386                         return -EFAULT;
387                 tv.tv_sec = old_tv.tv_sec;
388                 tv.tv_usec = old_tv.tv_usec;
389         } else {
390                 if (optlen < sizeof(tv))
391                         return -EINVAL;
392                 if (copy_from_user(&tv, optval, sizeof(tv)))
393                         return -EFAULT;
394         }
395         if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
396                 return -EDOM;
397 
398         if (tv.tv_sec < 0) {
399                 static int warned __read_mostly;
400 
401                 *timeo_p = 0;
402                 if (warned < 10 && net_ratelimit()) {
403                         warned++;
404                         pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
405                                 __func__, current->comm, task_pid_nr(current));
406                 }
407                 return 0;
408         }
409         *timeo_p = MAX_SCHEDULE_TIMEOUT;
410         if (tv.tv_sec == 0 && tv.tv_usec == 0)
411                 return 0;
412         if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1))
413                 *timeo_p = tv.tv_sec * HZ + DIV_ROUND_UP((unsigned long)tv.tv_usec, USEC_PER_SEC / HZ);
414         return 0;
415 }
416 
417 static void sock_warn_obsolete_bsdism(const char *name)
418 {
419         static int warned;
420         static char warncomm[TASK_COMM_LEN];
421         if (strcmp(warncomm, current->comm) && warned < 5) {
422                 strcpy(warncomm,  current->comm);
423                 pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
424                         warncomm, name);
425                 warned++;
426         }
427 }
428 
429 static bool sock_needs_netstamp(const struct sock *sk)
430 {
431         switch (sk->sk_family) {
432         case AF_UNSPEC:
433         case AF_UNIX:
434                 return false;
435         default:
436                 return true;
437         }
438 }
439 
440 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
441 {
442         if (sk->sk_flags & flags) {
443                 sk->sk_flags &= ~flags;
444                 if (sock_needs_netstamp(sk) &&
445                     !(sk->sk_flags & SK_FLAGS_TIMESTAMP))
446                         net_disable_timestamp();
447         }
448 }
449 
450 
451 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
452 {
453         unsigned long flags;
454         struct sk_buff_head *list = &sk->sk_receive_queue;
455 
456         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
457                 atomic_inc(&sk->sk_drops);
458                 trace_sock_rcvqueue_full(sk, skb);
459                 return -ENOMEM;
460         }
461 
462         if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
463                 atomic_inc(&sk->sk_drops);
464                 return -ENOBUFS;
465         }
466 
467         skb->dev = NULL;
468         skb_set_owner_r(skb, sk);
469 
470         /* we escape from rcu protected region, make sure we dont leak
471          * a norefcounted dst
472          */
473         skb_dst_force(skb);
474 
475         spin_lock_irqsave(&list->lock, flags);
476         sock_skb_set_dropcount(sk, skb);
477         __skb_queue_tail(list, skb);
478         spin_unlock_irqrestore(&list->lock, flags);
479 
480         if (!sock_flag(sk, SOCK_DEAD))
481                 sk->sk_data_ready(sk);
482         return 0;
483 }
484 EXPORT_SYMBOL(__sock_queue_rcv_skb);
485 
486 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
487 {
488         int err;
489 
490         err = sk_filter(sk, skb);
491         if (err)
492                 return err;
493 
494         return __sock_queue_rcv_skb(sk, skb);
495 }
496 EXPORT_SYMBOL(sock_queue_rcv_skb);
497 
498 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
499                      const int nested, unsigned int trim_cap, bool refcounted)
500 {
501         int rc = NET_RX_SUCCESS;
502 
503         if (sk_filter_trim_cap(sk, skb, trim_cap))
504                 goto discard_and_relse;
505 
506         skb->dev = NULL;
507 
508         if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
509                 atomic_inc(&sk->sk_drops);
510                 goto discard_and_relse;
511         }
512         if (nested)
513                 bh_lock_sock_nested(sk);
514         else
515                 bh_lock_sock(sk);
516         if (!sock_owned_by_user(sk)) {
517                 /*
518                  * trylock + unlock semantics:
519                  */
520                 mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
521 
522                 rc = sk_backlog_rcv(sk, skb);
523 
524                 mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
525         } else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
526                 bh_unlock_sock(sk);
527                 atomic_inc(&sk->sk_drops);
528                 goto discard_and_relse;
529         }
530 
531         bh_unlock_sock(sk);
532 out:
533         if (refcounted)
534                 sock_put(sk);
535         return rc;
536 discard_and_relse:
537         kfree_skb(skb);
538         goto out;
539 }
540 EXPORT_SYMBOL(__sk_receive_skb);
541 
542 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
543 {
544         struct dst_entry *dst = __sk_dst_get(sk);
545 
546         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
547                 sk_tx_queue_clear(sk);
548                 sk->sk_dst_pending_confirm = 0;
549                 RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
550                 dst_release(dst);
551                 return NULL;
552         }
553 
554         return dst;
555 }
556 EXPORT_SYMBOL(__sk_dst_check);
557 
558 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
559 {
560         struct dst_entry *dst = sk_dst_get(sk);
561 
562         if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
563                 sk_dst_reset(sk);
564                 dst_release(dst);
565                 return NULL;
566         }
567 
568         return dst;
569 }
570 EXPORT_SYMBOL(sk_dst_check);
571 
572 static int sock_setbindtodevice_locked(struct sock *sk, int ifindex)
573 {
574         int ret = -ENOPROTOOPT;
575 #ifdef CONFIG_NETDEVICES
576         struct net *net = sock_net(sk);
577 
578         /* Sorry... */
579         ret = -EPERM;
580         if (!ns_capable(net->user_ns, CAP_NET_RAW))
581                 goto out;
582 
583         ret = -EINVAL;
584         if (ifindex < 0)
585                 goto out;
586 
587         sk->sk_bound_dev_if = ifindex;
588         if (sk->sk_prot->rehash)
589                 sk->sk_prot->rehash(sk);
590         sk_dst_reset(sk);
591 
592         ret = 0;
593 
594 out:
595 #endif
596 
597         return ret;
598 }
599 
600 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
601                                 int optlen)
602 {
603         int ret = -ENOPROTOOPT;
604 #ifdef CONFIG_NETDEVICES
605         struct net *net = sock_net(sk);
606         char devname[IFNAMSIZ];
607         int index;
608 
609         ret = -EINVAL;
610         if (optlen < 0)
611                 goto out;
612 
613         /* Bind this socket to a particular device like "eth0",
614          * as specified in the passed interface name. If the
615          * name is "" or the option length is zero the socket
616          * is not bound.
617          */
618         if (optlen > IFNAMSIZ - 1)
619                 optlen = IFNAMSIZ - 1;
620         memset(devname, 0, sizeof(devname));
621 
622         ret = -EFAULT;
623         if (copy_from_user(devname, optval, optlen))
624                 goto out;
625 
626         index = 0;
627         if (devname[0] != '\0') {
628                 struct net_device *dev;
629 
630                 rcu_read_lock();
631                 dev = dev_get_by_name_rcu(net, devname);
632                 if (dev)
633                         index = dev->ifindex;
634                 rcu_read_unlock();
635                 ret = -ENODEV;
636                 if (!dev)
637                         goto out;
638         }
639 
640         lock_sock(sk);
641         ret = sock_setbindtodevice_locked(sk, index);
642         release_sock(sk);
643 
644 out:
645 #endif
646 
647         return ret;
648 }
649 
650 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
651                                 int __user *optlen, int len)
652 {
653         int ret = -ENOPROTOOPT;
654 #ifdef CONFIG_NETDEVICES
655         struct net *net = sock_net(sk);
656         char devname[IFNAMSIZ];
657 
658         if (sk->sk_bound_dev_if == 0) {
659                 len = 0;
660                 goto zero;
661         }
662 
663         ret = -EINVAL;
664         if (len < IFNAMSIZ)
665                 goto out;
666 
667         ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
668         if (ret)
669                 goto out;
670 
671         len = strlen(devname) + 1;
672 
673         ret = -EFAULT;
674         if (copy_to_user(optval, devname, len))
675                 goto out;
676 
677 zero:
678         ret = -EFAULT;
679         if (put_user(len, optlen))
680                 goto out;
681 
682         ret = 0;
683 
684 out:
685 #endif
686 
687         return ret;
688 }
689 
690 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
691 {
692         if (valbool)
693                 sock_set_flag(sk, bit);
694         else
695                 sock_reset_flag(sk, bit);
696 }
697 
698 bool sk_mc_loop(struct sock *sk)
699 {
700         if (dev_recursion_level())
701                 return false;
702         if (!sk)
703                 return true;
704         switch (sk->sk_family) {
705         case AF_INET:
706                 return inet_sk(sk)->mc_loop;
707 #if IS_ENABLED(CONFIG_IPV6)
708         case AF_INET6:
709                 return inet6_sk(sk)->mc_loop;
710 #endif
711         }
712         WARN_ON(1);
713         return true;
714 }
715 EXPORT_SYMBOL(sk_mc_loop);
716 
717 /*
718  *      This is meant for all protocols to use and covers goings on
719  *      at the socket level. Everything here is generic.
720  */
721 
722 int sock_setsockopt(struct socket *sock, int level, int optname,
723                     char __user *optval, unsigned int optlen)
724 {
725         struct sock_txtime sk_txtime;
726         struct sock *sk = sock->sk;
727         int val;
728         int valbool;
729         struct linger ling;
730         int ret = 0;
731 
732         /*
733          *      Options without arguments
734          */
735 
736         if (optname == SO_BINDTODEVICE)
737                 return sock_setbindtodevice(sk, optval, optlen);
738 
739         if (optlen < sizeof(int))
740                 return -EINVAL;
741 
742         if (get_user(val, (int __user *)optval))
743                 return -EFAULT;
744 
745         valbool = val ? 1 : 0;
746 
747         lock_sock(sk);
748 
749         switch (optname) {
750         case SO_DEBUG:
751                 if (val && !capable(CAP_NET_ADMIN))
752                         ret = -EACCES;
753                 else
754                         sock_valbool_flag(sk, SOCK_DBG, valbool);
755                 break;
756         case SO_REUSEADDR:
757                 sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
758                 break;
759         case SO_REUSEPORT:
760                 sk->sk_reuseport = valbool;
761                 break;
762         case SO_TYPE:
763         case SO_PROTOCOL:
764         case SO_DOMAIN:
765         case SO_ERROR:
766                 ret = -ENOPROTOOPT;
767                 break;
768         case SO_DONTROUTE:
769                 sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
770                 sk_dst_reset(sk);
771                 break;
772         case SO_BROADCAST:
773                 sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
774                 break;
775         case SO_SNDBUF:
776                 /* Don't error on this BSD doesn't and if you think
777                  * about it this is right. Otherwise apps have to
778                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
779                  * are treated in BSD as hints
780                  */
781                 val = min_t(u32, val, sysctl_wmem_max);
782 set_sndbuf:
783                 /* Ensure val * 2 fits into an int, to prevent max_t()
784                  * from treating it as a negative value.
785                  */
786                 val = min_t(int, val, INT_MAX / 2);
787                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
788                 sk->sk_sndbuf = max_t(int, val * 2, SOCK_MIN_SNDBUF);
789                 /* Wake up sending tasks if we upped the value. */
790                 sk->sk_write_space(sk);
791                 break;
792 
793         case SO_SNDBUFFORCE:
794                 if (!capable(CAP_NET_ADMIN)) {
795                         ret = -EPERM;
796                         break;
797                 }
798 
799                 /* No negative values (to prevent underflow, as val will be
800                  * multiplied by 2).
801                  */
802                 if (val < 0)
803                         val = 0;
804                 goto set_sndbuf;
805 
806         case SO_RCVBUF:
807                 /* Don't error on this BSD doesn't and if you think
808                  * about it this is right. Otherwise apps have to
809                  * play 'guess the biggest size' games. RCVBUF/SNDBUF
810                  * are treated in BSD as hints
811                  */
812                 val = min_t(u32, val, sysctl_rmem_max);
813 set_rcvbuf:
814                 /* Ensure val * 2 fits into an int, to prevent max_t()
815                  * from treating it as a negative value.
816                  */
817                 val = min_t(int, val, INT_MAX / 2);
818                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
819                 /*
820                  * We double it on the way in to account for
821                  * "struct sk_buff" etc. overhead.   Applications
822                  * assume that the SO_RCVBUF setting they make will
823                  * allow that much actual data to be received on that
824                  * socket.
825                  *
826                  * Applications are unaware that "struct sk_buff" and
827                  * other overheads allocate from the receive buffer
828                  * during socket buffer allocation.
829                  *
830                  * And after considering the possible alternatives,
831                  * returning the value we actually used in getsockopt
832                  * is the most desirable behavior.
833                  */
834                 sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
835                 break;
836 
837         case SO_RCVBUFFORCE:
838                 if (!capable(CAP_NET_ADMIN)) {
839                         ret = -EPERM;
840                         break;
841                 }
842 
843                 /* No negative values (to prevent underflow, as val will be
844                  * multiplied by 2).
845                  */
846                 if (val < 0)
847                         val = 0;
848                 goto set_rcvbuf;
849 
850         case SO_KEEPALIVE:
851                 if (sk->sk_prot->keepalive)
852                         sk->sk_prot->keepalive(sk, valbool);
853                 sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
854                 break;
855 
856         case SO_OOBINLINE:
857                 sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
858                 break;
859 
860         case SO_NO_CHECK:
861                 sk->sk_no_check_tx = valbool;
862                 break;
863 
864         case SO_PRIORITY:
865                 if ((val >= 0 && val <= 6) ||
866                     ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
867                         sk->sk_priority = val;
868                 else
869                         ret = -EPERM;
870                 break;
871 
872         case SO_LINGER:
873                 if (optlen < sizeof(ling)) {
874                         ret = -EINVAL;  /* 1003.1g */
875                         break;
876                 }
877                 if (copy_from_user(&ling, optval, sizeof(ling))) {
878                         ret = -EFAULT;
879                         break;
880                 }
881                 if (!ling.l_onoff)
882                         sock_reset_flag(sk, SOCK_LINGER);
883                 else {
884 #if (BITS_PER_LONG == 32)
885                         if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
886                                 sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
887                         else
888 #endif
889                                 sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
890                         sock_set_flag(sk, SOCK_LINGER);
891                 }
892                 break;
893 
894         case SO_BSDCOMPAT:
895                 sock_warn_obsolete_bsdism("setsockopt");
896                 break;
897 
898         case SO_PASSCRED:
899                 if (valbool)
900                         set_bit(SOCK_PASSCRED, &sock->flags);
901                 else
902                         clear_bit(SOCK_PASSCRED, &sock->flags);
903                 break;
904 
905         case SO_TIMESTAMP_OLD:
906         case SO_TIMESTAMP_NEW:
907         case SO_TIMESTAMPNS_OLD:
908         case SO_TIMESTAMPNS_NEW:
909                 if (valbool)  {
910                         if (optname == SO_TIMESTAMP_NEW || optname == SO_TIMESTAMPNS_NEW)
911                                 sock_set_flag(sk, SOCK_TSTAMP_NEW);
912                         else
913                                 sock_reset_flag(sk, SOCK_TSTAMP_NEW);
914 
915                         if (optname == SO_TIMESTAMP_OLD || optname == SO_TIMESTAMP_NEW)
916                                 sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
917                         else
918                                 sock_set_flag(sk, SOCK_RCVTSTAMPNS);
919                         sock_set_flag(sk, SOCK_RCVTSTAMP);
920                         sock_enable_timestamp(sk, SOCK_TIMESTAMP);
921                 } else {
922                         sock_reset_flag(sk, SOCK_RCVTSTAMP);
923                         sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
924                         sock_reset_flag(sk, SOCK_TSTAMP_NEW);
925                 }
926                 break;
927 
928         case SO_TIMESTAMPING_NEW:
929                 sock_set_flag(sk, SOCK_TSTAMP_NEW);
930                 /* fall through */
931         case SO_TIMESTAMPING_OLD:
932                 if (val & ~SOF_TIMESTAMPING_MASK) {
933                         ret = -EINVAL;
934                         break;
935                 }
936 
937                 if (val & SOF_TIMESTAMPING_OPT_ID &&
938                     !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
939                         if (sk->sk_protocol == IPPROTO_TCP &&
940                             sk->sk_type == SOCK_STREAM) {
941                                 if ((1 << sk->sk_state) &
942                                     (TCPF_CLOSE | TCPF_LISTEN)) {
943                                         ret = -EINVAL;
944                                         break;
945                                 }
946                                 sk->sk_tskey = tcp_sk(sk)->snd_una;
947                         } else {
948                                 sk->sk_tskey = 0;
949                         }
950                 }
951 
952                 if (val & SOF_TIMESTAMPING_OPT_STATS &&
953                     !(val & SOF_TIMESTAMPING_OPT_TSONLY)) {
954                         ret = -EINVAL;
955                         break;
956                 }
957 
958                 sk->sk_tsflags = val;
959                 if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
960                         sock_enable_timestamp(sk,
961                                               SOCK_TIMESTAMPING_RX_SOFTWARE);
962                 else {
963                         if (optname == SO_TIMESTAMPING_NEW)
964                                 sock_reset_flag(sk, SOCK_TSTAMP_NEW);
965 
966                         sock_disable_timestamp(sk,
967                                                (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
968                 }
969                 break;
970 
971         case SO_RCVLOWAT:
972                 if (val < 0)
973                         val = INT_MAX;
974                 if (sock->ops->set_rcvlowat)
975                         ret = sock->ops->set_rcvlowat(sk, val);
976                 else
977                         sk->sk_rcvlowat = val ? : 1;
978                 break;
979 
980         case SO_RCVTIMEO_OLD:
981         case SO_RCVTIMEO_NEW:
982                 ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen, optname == SO_RCVTIMEO_OLD);
983                 break;
984 
985         case SO_SNDTIMEO_OLD:
986         case SO_SNDTIMEO_NEW:
987                 ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen, optname == SO_SNDTIMEO_OLD);
988                 break;
989 
990         case SO_ATTACH_FILTER:
991                 ret = -EINVAL;
992                 if (optlen == sizeof(struct sock_fprog)) {
993                         struct sock_fprog fprog;
994 
995                         ret = -EFAULT;
996                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
997                                 break;
998 
999                         ret = sk_attach_filter(&fprog, sk);
1000                 }
1001                 break;
1002 
1003         case SO_ATTACH_BPF:
1004                 ret = -EINVAL;
1005                 if (optlen == sizeof(u32)) {
1006                         u32 ufd;
1007 
1008                         ret = -EFAULT;
1009                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
1010                                 break;
1011 
1012                         ret = sk_attach_bpf(ufd, sk);
1013                 }
1014                 break;
1015 
1016         case SO_ATTACH_REUSEPORT_CBPF:
1017                 ret = -EINVAL;
1018                 if (optlen == sizeof(struct sock_fprog)) {
1019                         struct sock_fprog fprog;
1020 
1021                         ret = -EFAULT;
1022                         if (copy_from_user(&fprog, optval, sizeof(fprog)))
1023                                 break;
1024 
1025                         ret = sk_reuseport_attach_filter(&fprog, sk);
1026                 }
1027                 break;
1028 
1029         case SO_ATTACH_REUSEPORT_EBPF:
1030                 ret = -EINVAL;
1031                 if (optlen == sizeof(u32)) {
1032                         u32 ufd;
1033 
1034                         ret = -EFAULT;
1035                         if (copy_from_user(&ufd, optval, sizeof(ufd)))
1036                                 break;
1037 
1038                         ret = sk_reuseport_attach_bpf(ufd, sk);
1039                 }
1040                 break;
1041 
1042         case SO_DETACH_REUSEPORT_BPF:
1043                 ret = reuseport_detach_prog(sk);
1044                 break;
1045 
1046         case SO_DETACH_FILTER:
1047                 ret = sk_detach_filter(sk);
1048                 break;
1049 
1050         case SO_LOCK_FILTER:
1051                 if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
1052                         ret = -EPERM;
1053                 else
1054                         sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
1055                 break;
1056 
1057         case SO_PASSSEC:
1058                 if (valbool)
1059                         set_bit(SOCK_PASSSEC, &sock->flags);
1060                 else
1061                         clear_bit(SOCK_PASSSEC, &sock->flags);
1062                 break;
1063         case SO_MARK:
1064                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1065                         ret = -EPERM;
1066                 } else if (val != sk->sk_mark) {
1067                         sk->sk_mark = val;
1068                         sk_dst_reset(sk);
1069                 }
1070                 break;
1071 
1072         case SO_RXQ_OVFL:
1073                 sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
1074                 break;
1075 
1076         case SO_WIFI_STATUS:
1077                 sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
1078                 break;
1079 
1080         case SO_PEEK_OFF:
1081                 if (sock->ops->set_peek_off)
1082                         ret = sock->ops->set_peek_off(sk, val);
1083                 else
1084                         ret = -EOPNOTSUPP;
1085                 break;
1086 
1087         case SO_NOFCS:
1088                 sock_valbool_flag(sk, SOCK_NOFCS, valbool);
1089                 break;
1090 
1091         case SO_SELECT_ERR_QUEUE:
1092                 sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
1093                 break;
1094 
1095 #ifdef CONFIG_NET_RX_BUSY_POLL
1096         case SO_BUSY_POLL:
1097                 /* allow unprivileged users to decrease the value */
1098                 if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
1099                         ret = -EPERM;
1100                 else {
1101                         if (val < 0)
1102                                 ret = -EINVAL;
1103                         else
1104                                 sk->sk_ll_usec = val;
1105                 }
1106                 break;
1107 #endif
1108 
1109         case SO_MAX_PACING_RATE:
1110                 {
1111                 unsigned long ulval = (val == ~0U) ? ~0UL : val;
1112 
1113                 if (sizeof(ulval) != sizeof(val) &&
1114                     optlen >= sizeof(ulval) &&
1115                     get_user(ulval, (unsigned long __user *)optval)) {
1116                         ret = -EFAULT;
1117                         break;
1118                 }
1119                 if (ulval != ~0UL)
1120                         cmpxchg(&sk->sk_pacing_status,
1121                                 SK_PACING_NONE,
1122                                 SK_PACING_NEEDED);
1123                 sk->sk_max_pacing_rate = ulval;
1124                 sk->sk_pacing_rate = min(sk->sk_pacing_rate, ulval);
1125                 break;
1126                 }
1127         case SO_INCOMING_CPU:
1128                 WRITE_ONCE(sk->sk_incoming_cpu, val);
1129                 break;
1130 
1131         case SO_CNX_ADVICE:
1132                 if (val == 1)
1133                         dst_negative_advice(sk);
1134                 break;
1135 
1136         case SO_ZEROCOPY:
1137                 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
1138                         if (!((sk->sk_type == SOCK_STREAM &&
1139                                sk->sk_protocol == IPPROTO_TCP) ||
1140                               (sk->sk_type == SOCK_DGRAM &&
1141                                sk->sk_protocol == IPPROTO_UDP)))
1142                                 ret = -ENOTSUPP;
1143                 } else if (sk->sk_family != PF_RDS) {
1144                         ret = -ENOTSUPP;
1145                 }
1146                 if (!ret) {
1147                         if (val < 0 || val > 1)
1148                                 ret = -EINVAL;
1149                         else
1150                                 sock_valbool_flag(sk, SOCK_ZEROCOPY, valbool);
1151                 }
1152                 break;
1153 
1154         case SO_TXTIME:
1155                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1156                         ret = -EPERM;
1157                 } else if (optlen != sizeof(struct sock_txtime)) {
1158                         ret = -EINVAL;
1159                 } else if (copy_from_user(&sk_txtime, optval,
1160                            sizeof(struct sock_txtime))) {
1161                         ret = -EFAULT;
1162                 } else if (sk_txtime.flags & ~SOF_TXTIME_FLAGS_MASK) {
1163                         ret = -EINVAL;
1164                 } else {
1165                         sock_valbool_flag(sk, SOCK_TXTIME, true);
1166                         sk->sk_clockid = sk_txtime.clockid;
1167                         sk->sk_txtime_deadline_mode =
1168                                 !!(sk_txtime.flags & SOF_TXTIME_DEADLINE_MODE);
1169                         sk->sk_txtime_report_errors =
1170                                 !!(sk_txtime.flags & SOF_TXTIME_REPORT_ERRORS);
1171                 }
1172                 break;
1173 
1174         case SO_BINDTOIFINDEX:
1175                 ret = sock_setbindtodevice_locked(sk, val);
1176                 break;
1177 
1178         default:
1179                 ret = -ENOPROTOOPT;
1180                 break;
1181         }
1182         release_sock(sk);
1183         return ret;
1184 }
1185 EXPORT_SYMBOL(sock_setsockopt);
1186 
1187 
1188 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
1189                           struct ucred *ucred)
1190 {
1191         ucred->pid = pid_vnr(pid);
1192         ucred->uid = ucred->gid = -1;
1193         if (cred) {
1194                 struct user_namespace *current_ns = current_user_ns();
1195 
1196                 ucred->uid = from_kuid_munged(current_ns, cred->euid);
1197                 ucred->gid = from_kgid_munged(current_ns, cred->egid);
1198         }
1199 }
1200 
1201 static int groups_to_user(gid_t __user *dst, const struct group_info *src)
1202 {
1203         struct user_namespace *user_ns = current_user_ns();
1204         int i;
1205 
1206         for (i = 0; i < src->ngroups; i++)
1207                 if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
1208                         return -EFAULT;
1209 
1210         return 0;
1211 }
1212 
1213 int sock_getsockopt(struct socket *sock, int level, int optname,
1214                     char __user *optval, int __user *optlen)
1215 {
1216         struct sock *sk = sock->sk;
1217 
1218         union {
1219                 int val;
1220                 u64 val64;
1221                 unsigned long ulval;
1222                 struct linger ling;
1223                 struct old_timeval32 tm32;
1224                 struct __kernel_old_timeval tm;
1225                 struct  __kernel_sock_timeval stm;
1226                 struct sock_txtime txtime;
1227         } v;
1228 
1229         int lv = sizeof(int);
1230         int len;
1231 
1232         if (get_user(len, optlen))
1233                 return -EFAULT;
1234         if (len < 0)
1235                 return -EINVAL;
1236 
1237         memset(&v, 0, sizeof(v));
1238 
1239         switch (optname) {
1240         case SO_DEBUG:
1241                 v.val = sock_flag(sk, SOCK_DBG);
1242                 break;
1243 
1244         case SO_DONTROUTE:
1245                 v.val = sock_flag(sk, SOCK_LOCALROUTE);
1246                 break;
1247 
1248         case SO_BROADCAST:
1249                 v.val = sock_flag(sk, SOCK_BROADCAST);
1250                 break;
1251 
1252         case SO_SNDBUF:
1253                 v.val = sk->sk_sndbuf;
1254                 break;
1255 
1256         case SO_RCVBUF:
1257                 v.val = sk->sk_rcvbuf;
1258                 break;
1259 
1260         case SO_REUSEADDR:
1261                 v.val = sk->sk_reuse;
1262                 break;
1263 
1264         case SO_REUSEPORT:
1265                 v.val = sk->sk_reuseport;
1266                 break;
1267 
1268         case SO_KEEPALIVE:
1269                 v.val = sock_flag(sk, SOCK_KEEPOPEN);
1270                 break;
1271 
1272         case SO_TYPE:
1273                 v.val = sk->sk_type;
1274                 break;
1275 
1276         case SO_PROTOCOL:
1277                 v.val = sk->sk_protocol;
1278                 break;
1279 
1280         case SO_DOMAIN:
1281                 v.val = sk->sk_family;
1282                 break;
1283 
1284         case SO_ERROR:
1285                 v.val = -sock_error(sk);
1286                 if (v.val == 0)
1287                         v.val = xchg(&sk->sk_err_soft, 0);
1288                 break;
1289 
1290         case SO_OOBINLINE:
1291                 v.val = sock_flag(sk, SOCK_URGINLINE);
1292                 break;
1293 
1294         case SO_NO_CHECK:
1295                 v.val = sk->sk_no_check_tx;
1296                 break;
1297 
1298         case SO_PRIORITY:
1299                 v.val = sk->sk_priority;
1300                 break;
1301 
1302         case SO_LINGER:
1303                 lv              = sizeof(v.ling);
1304                 v.ling.l_onoff  = sock_flag(sk, SOCK_LINGER);
1305                 v.ling.l_linger = sk->sk_lingertime / HZ;
1306                 break;
1307 
1308         case SO_BSDCOMPAT:
1309                 sock_warn_obsolete_bsdism("getsockopt");
1310                 break;
1311 
1312         case SO_TIMESTAMP_OLD:
1313                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1314                                 !sock_flag(sk, SOCK_TSTAMP_NEW) &&
1315                                 !sock_flag(sk, SOCK_RCVTSTAMPNS);
1316                 break;
1317 
1318         case SO_TIMESTAMPNS_OLD:
1319                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && !sock_flag(sk, SOCK_TSTAMP_NEW);
1320                 break;
1321 
1322         case SO_TIMESTAMP_NEW:
1323                 v.val = sock_flag(sk, SOCK_RCVTSTAMP) && sock_flag(sk, SOCK_TSTAMP_NEW);
1324                 break;
1325 
1326         case SO_TIMESTAMPNS_NEW:
1327                 v.val = sock_flag(sk, SOCK_RCVTSTAMPNS) && sock_flag(sk, SOCK_TSTAMP_NEW);
1328                 break;
1329 
1330         case SO_TIMESTAMPING_OLD:
1331                 v.val = sk->sk_tsflags;
1332                 break;
1333 
1334         case SO_RCVTIMEO_OLD:
1335         case SO_RCVTIMEO_NEW:
1336                 lv = sock_get_timeout(sk->sk_rcvtimeo, &v, SO_RCVTIMEO_OLD == optname);
1337                 break;
1338 
1339         case SO_SNDTIMEO_OLD:
1340         case SO_SNDTIMEO_NEW:
1341                 lv = sock_get_timeout(sk->sk_sndtimeo, &v, SO_SNDTIMEO_OLD == optname);
1342                 break;
1343 
1344         case SO_RCVLOWAT:
1345                 v.val = sk->sk_rcvlowat;
1346                 break;
1347 
1348         case SO_SNDLOWAT:
1349                 v.val = 1;
1350                 break;
1351 
1352         case SO_PASSCRED:
1353                 v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1354                 break;
1355 
1356         case SO_PEERCRED:
1357         {
1358                 struct ucred peercred;
1359                 if (len > sizeof(peercred))
1360                         len = sizeof(peercred);
1361                 cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1362                 if (copy_to_user(optval, &peercred, len))
1363                         return -EFAULT;
1364                 goto lenout;
1365         }
1366 
1367         case SO_PEERGROUPS:
1368         {
1369                 int ret, n;
1370 
1371                 if (!sk->sk_peer_cred)
1372                         return -ENODATA;
1373 
1374                 n = sk->sk_peer_cred->group_info->ngroups;
1375                 if (len < n * sizeof(gid_t)) {
1376                         len = n * sizeof(gid_t);
1377                         return put_user(len, optlen) ? -EFAULT : -ERANGE;
1378                 }
1379                 len = n * sizeof(gid_t);
1380 
1381                 ret = groups_to_user((gid_t __user *)optval,
1382                                      sk->sk_peer_cred->group_info);
1383                 if (ret)
1384                         return ret;
1385                 goto lenout;
1386         }
1387 
1388         case SO_PEERNAME:
1389         {
1390                 char address[128];
1391 
1392                 lv = sock->ops->getname(sock, (struct sockaddr *)address, 2);
1393                 if (lv < 0)
1394                         return -ENOTCONN;
1395                 if (lv < len)
1396                         return -EINVAL;
1397                 if (copy_to_user(optval, address, len))
1398                         return -EFAULT;
1399                 goto lenout;
1400         }
1401 
1402         /* Dubious BSD thing... Probably nobody even uses it, but
1403          * the UNIX standard wants it for whatever reason... -DaveM
1404          */
1405         case SO_ACCEPTCONN:
1406                 v.val = sk->sk_state == TCP_LISTEN;
1407                 break;
1408 
1409         case SO_PASSSEC:
1410                 v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1411                 break;
1412 
1413         case SO_PEERSEC:
1414                 return security_socket_getpeersec_stream(sock, optval, optlen, len);
1415 
1416         case SO_MARK:
1417                 v.val = sk->sk_mark;
1418                 break;
1419 
1420         case SO_RXQ_OVFL:
1421                 v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1422                 break;
1423 
1424         case SO_WIFI_STATUS:
1425                 v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1426                 break;
1427 
1428         case SO_PEEK_OFF:
1429                 if (!sock->ops->set_peek_off)
1430                         return -EOPNOTSUPP;
1431 
1432                 v.val = sk->sk_peek_off;
1433                 break;
1434         case SO_NOFCS:
1435                 v.val = sock_flag(sk, SOCK_NOFCS);
1436                 break;
1437 
1438         case SO_BINDTODEVICE:
1439                 return sock_getbindtodevice(sk, optval, optlen, len);
1440 
1441         case SO_GET_FILTER:
1442                 len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1443                 if (len < 0)
1444                         return len;
1445 
1446                 goto lenout;
1447 
1448         case SO_LOCK_FILTER:
1449                 v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1450                 break;
1451 
1452         case SO_BPF_EXTENSIONS:
1453                 v.val = bpf_tell_extensions();
1454                 break;
1455 
1456         case SO_SELECT_ERR_QUEUE:
1457                 v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1458                 break;
1459 
1460 #ifdef CONFIG_NET_RX_BUSY_POLL
1461         case SO_BUSY_POLL:
1462                 v.val = sk->sk_ll_usec;
1463                 break;
1464 #endif
1465 
1466         case SO_MAX_PACING_RATE:
1467                 if (sizeof(v.ulval) != sizeof(v.val) && len >= sizeof(v.ulval)) {
1468                         lv = sizeof(v.ulval);
1469                         v.ulval = sk->sk_max_pacing_rate;
1470                 } else {
1471                         /* 32bit version */
1472                         v.val = min_t(unsigned long, sk->sk_max_pacing_rate, ~0U);
1473                 }
1474                 break;
1475 
1476         case SO_INCOMING_CPU:
1477                 v.val = READ_ONCE(sk->sk_incoming_cpu);
1478                 break;
1479 
1480         case SO_MEMINFO:
1481         {
1482                 u32 meminfo[SK_MEMINFO_VARS];
1483 
1484                 sk_get_meminfo(sk, meminfo);
1485 
1486                 len = min_t(unsigned int, len, sizeof(meminfo));
1487                 if (copy_to_user(optval, &meminfo, len))
1488                         return -EFAULT;
1489 
1490                 goto lenout;
1491         }
1492 
1493 #ifdef CONFIG_NET_RX_BUSY_POLL
1494         case SO_INCOMING_NAPI_ID:
1495                 v.val = READ_ONCE(sk->sk_napi_id);
1496 
1497                 /* aggregate non-NAPI IDs down to 0 */
1498                 if (v.val < MIN_NAPI_ID)
1499                         v.val = 0;
1500 
1501                 break;
1502 #endif
1503 
1504         case SO_COOKIE:
1505                 lv = sizeof(u64);
1506                 if (len < lv)
1507                         return -EINVAL;
1508                 v.val64 = sock_gen_cookie(sk);
1509                 break;
1510 
1511         case SO_ZEROCOPY:
1512                 v.val = sock_flag(sk, SOCK_ZEROCOPY);
1513                 break;
1514 
1515         case SO_TXTIME:
1516                 lv = sizeof(v.txtime);
1517                 v.txtime.clockid = sk->sk_clockid;
1518                 v.txtime.flags |= sk->sk_txtime_deadline_mode ?
1519                                   SOF_TXTIME_DEADLINE_MODE : 0;
1520                 v.txtime.flags |= sk->sk_txtime_report_errors ?
1521                                   SOF_TXTIME_REPORT_ERRORS : 0;
1522                 break;
1523 
1524         case SO_BINDTOIFINDEX:
1525                 v.val = sk->sk_bound_dev_if;
1526                 break;
1527 
1528         default:
1529                 /* We implement the SO_SNDLOWAT etc to not be settable
1530                  * (1003.1g 7).
1531                  */
1532                 return -ENOPROTOOPT;
1533         }
1534 
1535         if (len > lv)
1536                 len = lv;
1537         if (copy_to_user(optval, &v, len))
1538                 return -EFAULT;
1539 lenout:
1540         if (put_user(len, optlen))
1541                 return -EFAULT;
1542         return 0;
1543 }
1544 
1545 /*
1546  * Initialize an sk_lock.
1547  *
1548  * (We also register the sk_lock with the lock validator.)
1549  */
1550 static inline void sock_lock_init(struct sock *sk)
1551 {
1552         if (sk->sk_kern_sock)
1553                 sock_lock_init_class_and_name(
1554                         sk,
1555                         af_family_kern_slock_key_strings[sk->sk_family],
1556                         af_family_kern_slock_keys + sk->sk_family,
1557                         af_family_kern_key_strings[sk->sk_family],
1558                         af_family_kern_keys + sk->sk_family);
1559         else
1560                 sock_lock_init_class_and_name(
1561                         sk,
1562                         af_family_slock_key_strings[sk->sk_family],
1563                         af_family_slock_keys + sk->sk_family,
1564                         af_family_key_strings[sk->sk_family],
1565                         af_family_keys + sk->sk_family);
1566 }
1567 
1568 /*
1569  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1570  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1571  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1572  */
1573 static void sock_copy(struct sock *nsk, const struct sock *osk)
1574 {
1575 #ifdef CONFIG_SECURITY_NETWORK
1576         void *sptr = nsk->sk_security;
1577 #endif
1578         memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1579 
1580         memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1581                osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1582 
1583 #ifdef CONFIG_SECURITY_NETWORK
1584         nsk->sk_security = sptr;
1585         security_sk_clone(osk, nsk);
1586 #endif
1587 }
1588 
1589 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1590                 int family)
1591 {
1592         struct sock *sk;
1593         struct kmem_cache *slab;
1594 
1595         slab = prot->slab;
1596         if (slab != NULL) {
1597                 sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1598                 if (!sk)
1599                         return sk;
1600                 if (want_init_on_alloc(priority))
1601                         sk_prot_clear_nulls(sk, prot->obj_size);
1602         } else
1603                 sk = kmalloc(prot->obj_size, priority);
1604 
1605         if (sk != NULL) {
1606                 if (security_sk_alloc(sk, family, priority))
1607                         goto out_free;
1608 
1609                 if (!try_module_get(prot->owner))
1610                         goto out_free_sec;
1611                 sk_tx_queue_clear(sk);
1612         }
1613 
1614         return sk;
1615 
1616 out_free_sec:
1617         security_sk_free(sk);
1618 out_free:
1619         if (slab != NULL)
1620                 kmem_cache_free(slab, sk);
1621         else
1622                 kfree(sk);
1623         return NULL;
1624 }
1625 
1626 static void sk_prot_free(struct proto *prot, struct sock *sk)
1627 {
1628         struct kmem_cache *slab;
1629         struct module *owner;
1630 
1631         owner = prot->owner;
1632         slab = prot->slab;
1633 
1634         cgroup_sk_free(&sk->sk_cgrp_data);
1635         mem_cgroup_sk_free(sk);
1636         security_sk_free(sk);
1637         if (slab != NULL)
1638                 kmem_cache_free(slab, sk);
1639         else
1640                 kfree(sk);
1641         module_put(owner);
1642 }
1643 
1644 /**
1645  *      sk_alloc - All socket objects are allocated here
1646  *      @net: the applicable net namespace
1647  *      @family: protocol family
1648  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1649  *      @prot: struct proto associated with this new sock instance
1650  *      @kern: is this to be a kernel socket?
1651  */
1652 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1653                       struct proto *prot, int kern)
1654 {
1655         struct sock *sk;
1656 
1657         sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1658         if (sk) {
1659                 sk->sk_family = family;
1660                 /*
1661                  * See comment in struct sock definition to understand
1662                  * why we need sk_prot_creator -acme
1663                  */
1664                 sk->sk_prot = sk->sk_prot_creator = prot;
1665                 sk->sk_kern_sock = kern;
1666                 sock_lock_init(sk);
1667                 sk->sk_net_refcnt = kern ? 0 : 1;
1668                 if (likely(sk->sk_net_refcnt)) {
1669                         get_net(net);
1670                         sock_inuse_add(net, 1);
1671                 }
1672 
1673                 sock_net_set(sk, net);
1674                 refcount_set(&sk->sk_wmem_alloc, 1);
1675 
1676                 mem_cgroup_sk_alloc(sk);
1677                 cgroup_sk_alloc(&sk->sk_cgrp_data);
1678                 sock_update_classid(&sk->sk_cgrp_data);
1679                 sock_update_netprioidx(&sk->sk_cgrp_data);
1680         }
1681 
1682         return sk;
1683 }
1684 EXPORT_SYMBOL(sk_alloc);
1685 
1686 /* Sockets having SOCK_RCU_FREE will call this function after one RCU
1687  * grace period. This is the case for UDP sockets and TCP listeners.
1688  */
1689 static void __sk_destruct(struct rcu_head *head)
1690 {
1691         struct sock *sk = container_of(head, struct sock, sk_rcu);
1692         struct sk_filter *filter;
1693 
1694         if (sk->sk_destruct)
1695                 sk->sk_destruct(sk);
1696 
1697         filter = rcu_dereference_check(sk->sk_filter,
1698                                        refcount_read(&sk->sk_wmem_alloc) == 0);
1699         if (filter) {
1700                 sk_filter_uncharge(sk, filter);
1701                 RCU_INIT_POINTER(sk->sk_filter, NULL);
1702         }
1703 
1704         sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1705 
1706 #ifdef CONFIG_BPF_SYSCALL
1707         bpf_sk_storage_free(sk);
1708 #endif
1709 
1710         if (atomic_read(&sk->sk_omem_alloc))
1711                 pr_debug("%s: optmem leakage (%d bytes) detected\n",
1712                          __func__, atomic_read(&sk->sk_omem_alloc));
1713 
1714         if (sk->sk_frag.page) {
1715                 put_page(sk->sk_frag.page);
1716                 sk->sk_frag.page = NULL;
1717         }
1718 
1719         if (sk->sk_peer_cred)
1720                 put_cred(sk->sk_peer_cred);
1721         put_pid(sk->sk_peer_pid);
1722         if (likely(sk->sk_net_refcnt))
1723                 put_net(sock_net(sk));
1724         sk_prot_free(sk->sk_prot_creator, sk);
1725 }
1726 
1727 void sk_destruct(struct sock *sk)
1728 {
1729         bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
1730 
1731         if (rcu_access_pointer(sk->sk_reuseport_cb)) {
1732                 reuseport_detach_sock(sk);
1733                 use_call_rcu = true;
1734         }
1735 
1736         if (use_call_rcu)
1737                 call_rcu(&sk->sk_rcu, __sk_destruct);
1738         else
1739                 __sk_destruct(&sk->sk_rcu);
1740 }
1741 
1742 static void __sk_free(struct sock *sk)
1743 {
1744         if (likely(sk->sk_net_refcnt))
1745                 sock_inuse_add(sock_net(sk), -1);
1746 
1747         if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
1748                 sock_diag_broadcast_destroy(sk);
1749         else
1750                 sk_destruct(sk);
1751 }
1752 
1753 void sk_free(struct sock *sk)
1754 {
1755         /*
1756          * We subtract one from sk_wmem_alloc and can know if
1757          * some packets are still in some tx queue.
1758          * If not null, sock_wfree() will call __sk_free(sk) later
1759          */
1760         if (refcount_dec_and_test(&sk->sk_wmem_alloc))
1761                 __sk_free(sk);
1762 }
1763 EXPORT_SYMBOL(sk_free);
1764 
1765 static void sk_init_common(struct sock *sk)
1766 {
1767         skb_queue_head_init(&sk->sk_receive_queue);
1768         skb_queue_head_init(&sk->sk_write_queue);
1769         skb_queue_head_init(&sk->sk_error_queue);
1770 
1771         rwlock_init(&sk->sk_callback_lock);
1772         lockdep_set_class_and_name(&sk->sk_receive_queue.lock,
1773                         af_rlock_keys + sk->sk_family,
1774                         af_family_rlock_key_strings[sk->sk_family]);
1775         lockdep_set_class_and_name(&sk->sk_write_queue.lock,
1776                         af_wlock_keys + sk->sk_family,
1777                         af_family_wlock_key_strings[sk->sk_family]);
1778         lockdep_set_class_and_name(&sk->sk_error_queue.lock,
1779                         af_elock_keys + sk->sk_family,
1780                         af_family_elock_key_strings[sk->sk_family]);
1781         lockdep_set_class_and_name(&sk->sk_callback_lock,
1782                         af_callback_keys + sk->sk_family,
1783                         af_family_clock_key_strings[sk->sk_family]);
1784 }
1785 
1786 /**
1787  *      sk_clone_lock - clone a socket, and lock its clone
1788  *      @sk: the socket to clone
1789  *      @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1790  *
1791  *      Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1792  */
1793 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1794 {
1795         struct sock *newsk;
1796         bool is_charged = true;
1797 
1798         newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1799         if (newsk != NULL) {
1800                 struct sk_filter *filter;
1801 
1802                 sock_copy(newsk, sk);
1803 
1804                 newsk->sk_prot_creator = sk->sk_prot;
1805 
1806                 /* SANITY */
1807                 if (likely(newsk->sk_net_refcnt))
1808                         get_net(sock_net(newsk));
1809                 sk_node_init(&newsk->sk_node);
1810                 sock_lock_init(newsk);
1811                 bh_lock_sock(newsk);
1812                 newsk->sk_backlog.head  = newsk->sk_backlog.tail = NULL;
1813                 newsk->sk_backlog.len = 0;
1814 
1815                 atomic_set(&newsk->sk_rmem_alloc, 0);
1816                 /*
1817                  * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1818                  */
1819                 refcount_set(&newsk->sk_wmem_alloc, 1);
1820                 atomic_set(&newsk->sk_omem_alloc, 0);
1821                 sk_init_common(newsk);
1822 
1823                 newsk->sk_dst_cache     = NULL;
1824                 newsk->sk_dst_pending_confirm = 0;
1825                 newsk->sk_wmem_queued   = 0;
1826                 newsk->sk_forward_alloc = 0;
1827                 atomic_set(&newsk->sk_drops, 0);
1828                 newsk->sk_send_head     = NULL;
1829                 newsk->sk_userlocks     = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1830                 atomic_set(&newsk->sk_zckey, 0);
1831 
1832                 sock_reset_flag(newsk, SOCK_DONE);
1833                 mem_cgroup_sk_alloc(newsk);
1834                 cgroup_sk_alloc(&newsk->sk_cgrp_data);
1835 
1836                 rcu_read_lock();
1837                 filter = rcu_dereference(sk->sk_filter);
1838                 if (filter != NULL)
1839                         /* though it's an empty new sock, the charging may fail
1840                          * if sysctl_optmem_max was changed between creation of
1841                          * original socket and cloning
1842                          */
1843                         is_charged = sk_filter_charge(newsk, filter);
1844                 RCU_INIT_POINTER(newsk->sk_filter, filter);
1845                 rcu_read_unlock();
1846 
1847                 if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
1848                         /* We need to make sure that we don't uncharge the new
1849                          * socket if we couldn't charge it in the first place
1850                          * as otherwise we uncharge the parent's filter.
1851                          */
1852                         if (!is_charged)
1853                                 RCU_INIT_POINTER(newsk->sk_filter, NULL);
1854                         sk_free_unlock_clone(newsk);
1855                         newsk = NULL;
1856                         goto out;
1857                 }
1858                 RCU_INIT_POINTER(newsk->sk_reuseport_cb, NULL);
1859 #ifdef CONFIG_BPF_SYSCALL
1860                 RCU_INIT_POINTER(newsk->sk_bpf_storage, NULL);
1861 #endif
1862 
1863                 newsk->sk_err      = 0;
1864                 newsk->sk_err_soft = 0;
1865                 newsk->sk_priority = 0;
1866                 newsk->sk_incoming_cpu = raw_smp_processor_id();
1867                 if (likely(newsk->sk_net_refcnt))
1868                         sock_inuse_add(sock_net(newsk), 1);
1869 
1870                 /*
1871                  * Before updating sk_refcnt, we must commit prior changes to memory
1872                  * (Documentation/RCU/rculist_nulls.txt for details)
1873                  */
1874                 smp_wmb();
1875                 refcount_set(&newsk->sk_refcnt, 2);
1876 
1877                 /*
1878                  * Increment the counter in the same struct proto as the master
1879                  * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1880                  * is the same as sk->sk_prot->socks, as this field was copied
1881                  * with memcpy).
1882                  *
1883                  * This _changes_ the previous behaviour, where
1884                  * tcp_create_openreq_child always was incrementing the
1885                  * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1886                  * to be taken into account in all callers. -acme
1887                  */
1888                 sk_refcnt_debug_inc(newsk);
1889                 sk_set_socket(newsk, NULL);
1890                 RCU_INIT_POINTER(newsk->sk_wq, NULL);
1891 
1892                 if (newsk->sk_prot->sockets_allocated)
1893                         sk_sockets_allocated_inc(newsk);
1894 
1895                 if (sock_needs_netstamp(sk) &&
1896                     newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1897                         net_enable_timestamp();
1898         }
1899 out:
1900         return newsk;
1901 }
1902 EXPORT_SYMBOL_GPL(sk_clone_lock);
1903 
1904 void sk_free_unlock_clone(struct sock *sk)
1905 {
1906         /* It is still raw copy of parent, so invalidate
1907          * destructor and make plain sk_free() */
1908         sk->sk_destruct = NULL;
1909         bh_unlock_sock(sk);
1910         sk_free(sk);
1911 }
1912 EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
1913 
1914 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1915 {
1916         u32 max_segs = 1;
1917 
1918         sk_dst_set(sk, dst);
1919         sk->sk_route_caps = dst->dev->features | sk->sk_route_forced_caps;
1920         if (sk->sk_route_caps & NETIF_F_GSO)
1921                 sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1922         sk->sk_route_caps &= ~sk->sk_route_nocaps;
1923         if (sk_can_gso(sk)) {
1924                 if (dst->header_len && !xfrm_dst_offload_ok(dst)) {
1925                         sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1926                 } else {
1927                         sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1928                         sk->sk_gso_max_size = dst->dev->gso_max_size;
1929                         max_segs = max_t(u32, dst->dev->gso_max_segs, 1);
1930                 }
1931         }
1932         sk->sk_gso_max_segs = max_segs;
1933 }
1934 EXPORT_SYMBOL_GPL(sk_setup_caps);
1935 
1936 /*
1937  *      Simple resource managers for sockets.
1938  */
1939 
1940 
1941 /*
1942  * Write buffer destructor automatically called from kfree_skb.
1943  */
1944 void sock_wfree(struct sk_buff *skb)
1945 {
1946         struct sock *sk = skb->sk;
1947         unsigned int len = skb->truesize;
1948 
1949         if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1950                 /*
1951                  * Keep a reference on sk_wmem_alloc, this will be released
1952                  * after sk_write_space() call
1953                  */
1954                 WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
1955                 sk->sk_write_space(sk);
1956                 len = 1;
1957         }
1958         /*
1959          * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1960          * could not do because of in-flight packets
1961          */
1962         if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
1963                 __sk_free(sk);
1964 }
1965 EXPORT_SYMBOL(sock_wfree);
1966 
1967 /* This variant of sock_wfree() is used by TCP,
1968  * since it sets SOCK_USE_WRITE_QUEUE.
1969  */
1970 void __sock_wfree(struct sk_buff *skb)
1971 {
1972         struct sock *sk = skb->sk;
1973 
1974         if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
1975                 __sk_free(sk);
1976 }
1977 
1978 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
1979 {
1980         skb_orphan(skb);
1981         skb->sk = sk;
1982 #ifdef CONFIG_INET
1983         if (unlikely(!sk_fullsock(sk))) {
1984                 skb->destructor = sock_edemux;
1985                 sock_hold(sk);
1986                 return;
1987         }
1988 #endif
1989         skb->destructor = sock_wfree;
1990         skb_set_hash_from_sk(skb, sk);
1991         /*
1992          * We used to take a refcount on sk, but following operation
1993          * is enough to guarantee sk_free() wont free this sock until
1994          * all in-flight packets are completed
1995          */
1996         refcount_add(skb->truesize, &sk->sk_wmem_alloc);
1997 }
1998 EXPORT_SYMBOL(skb_set_owner_w);
1999 
2000 static bool can_skb_orphan_partial(const struct sk_buff *skb)
2001 {
2002 #ifdef CONFIG_TLS_DEVICE
2003         /* Drivers depend on in-order delivery for crypto offload,
2004          * partial orphan breaks out-of-order-OK logic.
2005          */
2006         if (skb->decrypted)
2007                 return false;
2008 #endif
2009         return (skb->destructor == sock_wfree ||
2010                 (IS_ENABLED(CONFIG_INET) && skb->destructor == tcp_wfree));
2011 }
2012 
2013 /* This helper is used by netem, as it can hold packets in its
2014  * delay queue. We want to allow the owner socket to send more
2015  * packets, as if they were already TX completed by a typical driver.
2016  * But we also want to keep skb->sk set because some packet schedulers
2017  * rely on it (sch_fq for example).
2018  */
2019 void skb_orphan_partial(struct sk_buff *skb)
2020 {
2021         if (skb_is_tcp_pure_ack(skb))
2022                 return;
2023 
2024         if (can_skb_orphan_partial(skb)) {
2025                 struct sock *sk = skb->sk;
2026 
2027                 if (refcount_inc_not_zero(&sk->sk_refcnt)) {
2028                         WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
2029                         skb->destructor = sock_efree;
2030                 }
2031         } else {
2032                 skb_orphan(skb);
2033         }
2034 }
2035 EXPORT_SYMBOL(skb_orphan_partial);
2036 
2037 /*
2038  * Read buffer destructor automatically called from kfree_skb.
2039  */
2040 void sock_rfree(struct sk_buff *skb)
2041 {
2042         struct sock *sk = skb->sk;
2043         unsigned int len = skb->truesize;
2044 
2045         atomic_sub(len, &sk->sk_rmem_alloc);
2046         sk_mem_uncharge(sk, len);
2047 }
2048 EXPORT_SYMBOL(sock_rfree);
2049 
2050 /*
2051  * Buffer destructor for skbs that are not used directly in read or write
2052  * path, e.g. for error handler skbs. Automatically called from kfree_skb.
2053  */
2054 void sock_efree(struct sk_buff *skb)
2055 {
2056         sock_put(skb->sk);
2057 }
2058 EXPORT_SYMBOL(sock_efree);
2059 
2060 kuid_t sock_i_uid(struct sock *sk)
2061 {
2062         kuid_t uid;
2063 
2064         read_lock_bh(&sk->sk_callback_lock);
2065         uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
2066         read_unlock_bh(&sk->sk_callback_lock);
2067         return uid;
2068 }
2069 EXPORT_SYMBOL(sock_i_uid);
2070 
2071 unsigned long sock_i_ino(struct sock *sk)
2072 {
2073         unsigned long ino;
2074 
2075         read_lock_bh(&sk->sk_callback_lock);
2076         ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
2077         read_unlock_bh(&sk->sk_callback_lock);
2078         return ino;
2079 }
2080 EXPORT_SYMBOL(sock_i_ino);
2081 
2082 /*
2083  * Allocate a skb from the socket's send buffer.
2084  */
2085 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
2086                              gfp_t priority)
2087 {
2088         if (force || refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
2089                 struct sk_buff *skb = alloc_skb(size, priority);
2090                 if (skb) {
2091                         skb_set_owner_w(skb, sk);
2092                         return skb;
2093                 }
2094         }
2095         return NULL;
2096 }
2097 EXPORT_SYMBOL(sock_wmalloc);
2098 
2099 static void sock_ofree(struct sk_buff *skb)
2100 {
2101         struct sock *sk = skb->sk;
2102 
2103         atomic_sub(skb->truesize, &sk->sk_omem_alloc);
2104 }
2105 
2106 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
2107                              gfp_t priority)
2108 {
2109         struct sk_buff *skb;
2110 
2111         /* small safe race: SKB_TRUESIZE may differ from final skb->truesize */
2112         if (atomic_read(&sk->sk_omem_alloc) + SKB_TRUESIZE(size) >
2113             sysctl_optmem_max)
2114                 return NULL;
2115 
2116         skb = alloc_skb(size, priority);
2117         if (!skb)
2118                 return NULL;
2119 
2120         atomic_add(skb->truesize, &sk->sk_omem_alloc);
2121         skb->sk = sk;
2122         skb->destructor = sock_ofree;
2123         return skb;
2124 }
2125 
2126 /*
2127  * Allocate a memory block from the socket's option memory buffer.
2128  */
2129 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
2130 {
2131         if ((unsigned int)size <= sysctl_optmem_max &&
2132             atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
2133                 void *mem;
2134                 /* First do the add, to avoid the race if kmalloc
2135                  * might sleep.
2136                  */
2137                 atomic_add(size, &sk->sk_omem_alloc);
2138                 mem = kmalloc(size, priority);
2139                 if (mem)
2140                         return mem;
2141                 atomic_sub(size, &sk->sk_omem_alloc);
2142         }
2143         return NULL;
2144 }
2145 EXPORT_SYMBOL(sock_kmalloc);
2146 
2147 /* Free an option memory block. Note, we actually want the inline
2148  * here as this allows gcc to detect the nullify and fold away the
2149  * condition entirely.
2150  */
2151 static inline void __sock_kfree_s(struct sock *sk, void *mem, int size,
2152                                   const bool nullify)
2153 {
2154         if (WARN_ON_ONCE(!mem))
2155                 return;
2156         if (nullify)
2157                 kzfree(mem);
2158         else
2159                 kfree(mem);
2160         atomic_sub(size, &sk->sk_omem_alloc);
2161 }
2162 
2163 void sock_kfree_s(struct sock *sk, void *mem, int size)
2164 {
2165         __sock_kfree_s(sk, mem, size, false);
2166 }
2167 EXPORT_SYMBOL(sock_kfree_s);
2168 
2169 void sock_kzfree_s(struct sock *sk, void *mem, int size)
2170 {
2171         __sock_kfree_s(sk, mem, size, true);
2172 }
2173 EXPORT_SYMBOL(sock_kzfree_s);
2174 
2175 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
2176    I think, these locks should be removed for datagram sockets.
2177  */
2178 static long sock_wait_for_wmem(struct sock *sk, long timeo)
2179 {
2180         DEFINE_WAIT(wait);
2181 
2182         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2183         for (;;) {
2184                 if (!timeo)
2185                         break;
2186                 if (signal_pending(current))
2187                         break;
2188                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2189                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
2190                 if (refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
2191                         break;
2192                 if (sk->sk_shutdown & SEND_SHUTDOWN)
2193                         break;
2194                 if (sk->sk_err)
2195                         break;
2196                 timeo = schedule_timeout(timeo);
2197         }
2198         finish_wait(sk_sleep(sk), &wait);
2199         return timeo;
2200 }
2201 
2202 
2203 /*
2204  *      Generic send/receive buffer handlers
2205  */
2206 
2207 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
2208                                      unsigned long data_len, int noblock,
2209                                      int *errcode, int max_page_order)
2210 {
2211         struct sk_buff *skb;
2212         long timeo;
2213         int err;
2214 
2215         timeo = sock_sndtimeo(sk, noblock);
2216         for (;;) {
2217                 err = sock_error(sk);
2218                 if (err != 0)
2219                         goto failure;
2220 
2221                 err = -EPIPE;
2222                 if (sk->sk_shutdown & SEND_SHUTDOWN)
2223                         goto failure;
2224 
2225                 if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
2226                         break;
2227 
2228                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
2229                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
2230                 err = -EAGAIN;
2231                 if (!timeo)
2232                         goto failure;
2233                 if (signal_pending(current))
2234                         goto interrupted;
2235                 timeo = sock_wait_for_wmem(sk, timeo);
2236         }
2237         skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
2238                                    errcode, sk->sk_allocation);
2239         if (skb)
2240                 skb_set_owner_w(skb, sk);
2241         return skb;
2242 
2243 interrupted:
2244         err = sock_intr_errno(timeo);
2245 failure:
2246         *errcode = err;
2247         return NULL;
2248 }
2249 EXPORT_SYMBOL(sock_alloc_send_pskb);
2250 
2251 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
2252                                     int noblock, int *errcode)
2253 {
2254         return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
2255 }
2256 EXPORT_SYMBOL(sock_alloc_send_skb);
2257 
2258 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
2259                      struct sockcm_cookie *sockc)
2260 {
2261         u32 tsflags;
2262 
2263         switch (cmsg->cmsg_type) {
2264         case SO_MARK:
2265                 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
2266                         return -EPERM;
2267                 if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2268                         return -EINVAL;
2269                 sockc->mark = *(u32 *)CMSG_DATA(cmsg);
2270                 break;
2271         case SO_TIMESTAMPING_OLD:
2272                 if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32)))
2273                         return -EINVAL;
2274 
2275                 tsflags = *(u32 *)CMSG_DATA(cmsg);
2276                 if (tsflags & ~SOF_TIMESTAMPING_TX_RECORD_MASK)
2277                         return -EINVAL;
2278 
2279                 sockc->tsflags &= ~SOF_TIMESTAMPING_TX_RECORD_MASK;
2280                 sockc->tsflags |= tsflags;
2281                 break;
2282         case SCM_TXTIME:
2283                 if (!sock_flag(sk, SOCK_TXTIME))
2284                         return -EINVAL;
2285                 if (cmsg->cmsg_len != CMSG_LEN(sizeof(u64)))
2286                         return -EINVAL;
2287                 sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg));
2288                 break;
2289         /* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */
2290         case SCM_RIGHTS:
2291         case SCM_CREDENTIALS:
2292                 break;
2293         default:
2294                 return -EINVAL;
2295         }
2296         return 0;
2297 }
2298 EXPORT_SYMBOL(__sock_cmsg_send);
2299 
2300 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
2301                    struct sockcm_cookie *sockc)
2302 {
2303         struct cmsghdr *cmsg;
2304         int ret;
2305 
2306         for_each_cmsghdr(cmsg, msg) {
2307                 if (!CMSG_OK(msg, cmsg))
2308                         return -EINVAL;
2309                 if (cmsg->cmsg_level != SOL_SOCKET)
2310                         continue;
2311                 ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
2312                 if (ret)
2313                         return ret;
2314         }
2315         return 0;
2316 }
2317 EXPORT_SYMBOL(sock_cmsg_send);
2318 
2319 static void sk_enter_memory_pressure(struct sock *sk)
2320 {
2321         if (!sk->sk_prot->enter_memory_pressure)
2322                 return;
2323 
2324         sk->sk_prot->enter_memory_pressure(sk);
2325 }
2326 
2327 static void sk_leave_memory_pressure(struct sock *sk)
2328 {
2329         if (sk->sk_prot->leave_memory_pressure) {
2330                 sk->sk_prot->leave_memory_pressure(sk);
2331         } else {
2332                 unsigned long *memory_pressure = sk->sk_prot->memory_pressure;
2333 
2334                 if (memory_pressure && *memory_pressure)
2335                         *memory_pressure = 0;
2336         }
2337 }
2338 
2339 /* On 32bit arches, an skb frag is limited to 2^15 */
2340 #define SKB_FRAG_PAGE_ORDER     get_order(32768)
2341 DEFINE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
2342 
2343 /**
2344  * skb_page_frag_refill - check that a page_frag contains enough room
2345  * @sz: minimum size of the fragment we want to get
2346  * @pfrag: pointer to page_frag
2347  * @gfp: priority for memory allocation
2348  *
2349  * Note: While this allocator tries to use high order pages, there is
2350  * no guarantee that allocations succeed. Therefore, @sz MUST be
2351  * less or equal than PAGE_SIZE.
2352  */
2353 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
2354 {
2355         if (pfrag->page) {
2356                 if (page_ref_count(pfrag->page) == 1) {
2357                         pfrag->offset = 0;
2358                         return true;
2359                 }
2360                 if (pfrag->offset + sz <= pfrag->size)
2361                         return true;
2362                 put_page(pfrag->page);
2363         }
2364 
2365         pfrag->offset = 0;
2366         if (SKB_FRAG_PAGE_ORDER &&
2367             !static_branch_unlikely(&net_high_order_alloc_disable_key)) {
2368                 /* Avoid direct reclaim but allow kswapd to wake */
2369                 pfrag->page = alloc_pages((gfp & ~__GFP_DIRECT_RECLAIM) |
2370                                           __GFP_COMP | __GFP_NOWARN |
2371                                           __GFP_NORETRY,
2372                                           SKB_FRAG_PAGE_ORDER);
2373                 if (likely(pfrag->page)) {
2374                         pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
2375                         return true;
2376                 }
2377         }
2378         pfrag->page = alloc_page(gfp);
2379         if (likely(pfrag->page)) {
2380                 pfrag->size = PAGE_SIZE;
2381                 return true;
2382         }
2383         return false;
2384 }
2385 EXPORT_SYMBOL(skb_page_frag_refill);
2386 
2387 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
2388 {
2389         if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
2390                 return true;
2391 
2392         sk_enter_memory_pressure(sk);
2393         sk_stream_moderate_sndbuf(sk);
2394         return false;
2395 }
2396 EXPORT_SYMBOL(sk_page_frag_refill);
2397 
2398 static void __lock_sock(struct sock *sk)
2399         __releases(&sk->sk_lock.slock)
2400         __acquires(&sk->sk_lock.slock)
2401 {
2402         DEFINE_WAIT(wait);
2403 
2404         for (;;) {
2405                 prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
2406                                         TASK_UNINTERRUPTIBLE);
2407                 spin_unlock_bh(&sk->sk_lock.slock);
2408                 schedule();
2409                 spin_lock_bh(&sk->sk_lock.slock);
2410                 if (!sock_owned_by_user(sk))
2411                         break;
2412         }
2413         finish_wait(&sk->sk_lock.wq, &wait);
2414 }
2415 
2416 void __release_sock(struct sock *sk)
2417         __releases(&sk->sk_lock.slock)
2418         __acquires(&sk->sk_lock.slock)
2419 {
2420         struct sk_buff *skb, *next;
2421 
2422         while ((skb = sk->sk_backlog.head) != NULL) {
2423                 sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
2424 
2425                 spin_unlock_bh(&sk->sk_lock.slock);
2426 
2427                 do {
2428                         next = skb->next;
2429                         prefetch(next);
2430                         WARN_ON_ONCE(skb_dst_is_noref(skb));
2431                         skb_mark_not_on_list(skb);
2432                         sk_backlog_rcv(sk, skb);
2433 
2434                         cond_resched();
2435 
2436                         skb = next;
2437                 } while (skb != NULL);
2438 
2439                 spin_lock_bh(&sk->sk_lock.slock);
2440         }
2441 
2442         /*
2443          * Doing the zeroing here guarantee we can not loop forever
2444          * while a wild producer attempts to flood us.
2445          */
2446         sk->sk_backlog.len = 0;
2447 }
2448 
2449 void __sk_flush_backlog(struct sock *sk)
2450 {
2451         spin_lock_bh(&sk->sk_lock.slock);
2452         __release_sock(sk);
2453         spin_unlock_bh(&sk->sk_lock.slock);
2454 }
2455 
2456 /**
2457  * sk_wait_data - wait for data to arrive at sk_receive_queue
2458  * @sk:    sock to wait on
2459  * @timeo: for how long
2460  * @skb:   last skb seen on sk_receive_queue
2461  *
2462  * Now socket state including sk->sk_err is changed only under lock,
2463  * hence we may omit checks after joining wait queue.
2464  * We check receive queue before schedule() only as optimization;
2465  * it is very likely that release_sock() added new data.
2466  */
2467 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb)
2468 {
2469         DEFINE_WAIT_FUNC(wait, woken_wake_function);
2470         int rc;
2471 
2472         add_wait_queue(sk_sleep(sk), &wait);
2473         sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2474         rc = sk_wait_event(sk, timeo, skb_peek_tail(&sk->sk_receive_queue) != skb, &wait);
2475         sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
2476         remove_wait_queue(sk_sleep(sk), &wait);
2477         return rc;
2478 }
2479 EXPORT_SYMBOL(sk_wait_data);
2480 
2481 /**
2482  *      __sk_mem_raise_allocated - increase memory_allocated
2483  *      @sk: socket
2484  *      @size: memory size to allocate
2485  *      @amt: pages to allocate
2486  *      @kind: allocation type
2487  *
2488  *      Similar to __sk_mem_schedule(), but does not update sk_forward_alloc
2489  */
2490 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
2491 {
2492         struct proto *prot = sk->sk_prot;
2493         long allocated = sk_memory_allocated_add(sk, amt);
2494         bool charged = true;
2495 
2496         if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
2497             !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
2498                 goto suppress_allocation;
2499 
2500         /* Under limit. */
2501         if (allocated <= sk_prot_mem_limits(sk, 0)) {
2502                 sk_leave_memory_pressure(sk);
2503                 return 1;
2504         }
2505 
2506         /* Under pressure. */
2507         if (allocated > sk_prot_mem_limits(sk, 1))
2508                 sk_enter_memory_pressure(sk);
2509 
2510         /* Over hard limit. */
2511         if (allocated > sk_prot_mem_limits(sk, 2))
2512                 goto suppress_allocation;
2513 
2514         /* guarantee minimum buffer size under pressure */
2515         if (kind == SK_MEM_RECV) {
2516                 if (atomic_read(&sk->sk_rmem_alloc) < sk_get_rmem0(sk, prot))
2517                         return 1;
2518 
2519         } else { /* SK_MEM_SEND */
2520                 int wmem0 = sk_get_wmem0(sk, prot);
2521 
2522                 if (sk->sk_type == SOCK_STREAM) {
2523                         if (sk->sk_wmem_queued < wmem0)
2524                                 return 1;
2525                 } else if (refcount_read(&sk->sk_wmem_alloc) < wmem0) {
2526                                 return 1;
2527                 }
2528         }
2529 
2530         if (sk_has_memory_pressure(sk)) {
2531                 u64 alloc;
2532 
2533                 if (!sk_under_memory_pressure(sk))
2534                         return 1;
2535                 alloc = sk_sockets_allocated_read_positive(sk);
2536                 if (sk_prot_mem_limits(sk, 2) > alloc *
2537                     sk_mem_pages(sk->sk_wmem_queued +
2538                                  atomic_read(&sk->sk_rmem_alloc) +
2539                                  sk->sk_forward_alloc))
2540                         return 1;
2541         }
2542 
2543 suppress_allocation:
2544 
2545         if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2546                 sk_stream_moderate_sndbuf(sk);
2547 
2548                 /* Fail only if socket is _under_ its sndbuf.
2549                  * In this case we cannot block, so that we have to fail.
2550                  */
2551                 if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2552                         return 1;
2553         }
2554 
2555         if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
2556                 trace_sock_exceed_buf_limit(sk, prot, allocated, kind);
2557 
2558         sk_memory_allocated_sub(sk, amt);
2559 
2560         if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2561                 mem_cgroup_uncharge_skmem(sk->sk_memcg, amt);
2562 
2563         return 0;
2564 }
2565 EXPORT_SYMBOL(__sk_mem_raise_allocated);
2566 
2567 /**
2568  *      __sk_mem_schedule - increase sk_forward_alloc and memory_allocated
2569  *      @sk: socket
2570  *      @size: memory size to allocate
2571  *      @kind: allocation type
2572  *
2573  *      If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
2574  *      rmem allocation. This function assumes that protocols which have
2575  *      memory_pressure use sk_wmem_queued as write buffer accounting.
2576  */
2577 int __sk_mem_schedule(struct sock *sk, int size, int kind)
2578 {
2579         int ret, amt = sk_mem_pages(size);
2580 
2581         sk->sk_forward_alloc += amt << SK_MEM_QUANTUM_SHIFT;
2582         ret = __sk_mem_raise_allocated(sk, size, amt, kind);
2583         if (!ret)
2584                 sk->sk_forward_alloc -= amt << SK_MEM_QUANTUM_SHIFT;
2585         return ret;
2586 }
2587 EXPORT_SYMBOL(__sk_mem_schedule);
2588 
2589 /**
2590  *      __sk_mem_reduce_allocated - reclaim memory_allocated
2591  *      @sk: socket
2592  *      @amount: number of quanta
2593  *
2594  *      Similar to __sk_mem_reclaim(), but does not update sk_forward_alloc
2595  */
2596 void __sk_mem_reduce_allocated(struct sock *sk, int amount)
2597 {
2598         sk_memory_allocated_sub(sk, amount);
2599 
2600         if (mem_cgroup_sockets_enabled && sk->sk_memcg)
2601                 mem_cgroup_uncharge_skmem(sk->sk_memcg, amount);
2602 
2603         if (sk_under_memory_pressure(sk) &&
2604             (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2605                 sk_leave_memory_pressure(sk);
2606 }
2607 EXPORT_SYMBOL(__sk_mem_reduce_allocated);
2608 
2609 /**
2610  *      __sk_mem_reclaim - reclaim sk_forward_alloc and memory_allocated
2611  *      @sk: socket
2612  *      @amount: number of bytes (rounded down to a SK_MEM_QUANTUM multiple)
2613  */
2614 void __sk_mem_reclaim(struct sock *sk, int amount)
2615 {
2616         amount >>= SK_MEM_QUANTUM_SHIFT;
2617         sk->sk_forward_alloc -= amount << SK_MEM_QUANTUM_SHIFT;
2618         __sk_mem_reduce_allocated(sk, amount);
2619 }
2620 EXPORT_SYMBOL(__sk_mem_reclaim);
2621 
2622 int sk_set_peek_off(struct sock *sk, int val)
2623 {
2624         sk->sk_peek_off = val;
2625         return 0;
2626 }
2627 EXPORT_SYMBOL_GPL(sk_set_peek_off);
2628 
2629 /*
2630  * Set of default routines for initialising struct proto_ops when
2631  * the protocol does not support a particular function. In certain
2632  * cases where it makes no sense for a protocol to have a "do nothing"
2633  * function, some default processing is provided.
2634  */
2635 
2636 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2637 {
2638         return -EOPNOTSUPP;
2639 }
2640 EXPORT_SYMBOL(sock_no_bind);
2641 
2642 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2643                     int len, int flags)
2644 {
2645         return -EOPNOTSUPP;
2646 }
2647 EXPORT_SYMBOL(sock_no_connect);
2648 
2649 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2650 {
2651         return -EOPNOTSUPP;
2652 }
2653 EXPORT_SYMBOL(sock_no_socketpair);
2654 
2655 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags,
2656                    bool kern)
2657 {
2658         return -EOPNOTSUPP;
2659 }
2660 EXPORT_SYMBOL(sock_no_accept);
2661 
2662 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2663                     int peer)
2664 {
2665         return -EOPNOTSUPP;
2666 }
2667 EXPORT_SYMBOL(sock_no_getname);
2668 
2669 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2670 {
2671         return -EOPNOTSUPP;
2672 }
2673 EXPORT_SYMBOL(sock_no_ioctl);
2674 
2675 int sock_no_listen(struct socket *sock, int backlog)
2676 {
2677         return -EOPNOTSUPP;
2678 }
2679 EXPORT_SYMBOL(sock_no_listen);
2680 
2681 int sock_no_shutdown(struct socket *sock, int how)
2682 {
2683         return -EOPNOTSUPP;
2684 }
2685 EXPORT_SYMBOL(sock_no_shutdown);
2686 
2687 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2688                     char __user *optval, unsigned int optlen)
2689 {
2690         return -EOPNOTSUPP;
2691 }
2692 EXPORT_SYMBOL(sock_no_setsockopt);
2693 
2694 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2695                     char __user *optval, int __user *optlen)
2696 {
2697         return -EOPNOTSUPP;
2698 }
2699 EXPORT_SYMBOL(sock_no_getsockopt);
2700 
2701 int sock_no_sendmsg(struct socket *sock, struct msghdr *m, size_t len)
2702 {
2703         return -EOPNOTSUPP;
2704 }
2705 EXPORT_SYMBOL(sock_no_sendmsg);
2706 
2707 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *m, size_t len)
2708 {
2709         return -EOPNOTSUPP;
2710 }
2711 EXPORT_SYMBOL(sock_no_sendmsg_locked);
2712 
2713 int sock_no_recvmsg(struct socket *sock, struct msghdr *m, size_t len,
2714                     int flags)
2715 {
2716         return -EOPNOTSUPP;
2717 }
2718 EXPORT_SYMBOL(sock_no_recvmsg);
2719 
2720 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2721 {
2722         /* Mirror missing mmap method error code */
2723         return -ENODEV;
2724 }
2725 EXPORT_SYMBOL(sock_no_mmap);
2726 
2727 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2728 {
2729         ssize_t res;
2730         struct msghdr msg = {.msg_flags = flags};
2731         struct kvec iov;
2732         char *kaddr = kmap(page);
2733         iov.iov_base = kaddr + offset;
2734         iov.iov_len = size;
2735         res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2736         kunmap(page);
2737         return res;
2738 }
2739 EXPORT_SYMBOL(sock_no_sendpage);
2740 
2741 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
2742                                 int offset, size_t size, int flags)
2743 {
2744         ssize_t res;
2745         struct msghdr msg = {.msg_flags = flags};
2746         struct kvec iov;
2747         char *kaddr = kmap(page);
2748 
2749         iov.iov_base = kaddr + offset;
2750         iov.iov_len = size;
2751         res = kernel_sendmsg_locked(sk, &msg, &iov, 1, size);
2752         kunmap(page);
2753         return res;
2754 }
2755 EXPORT_SYMBOL(sock_no_sendpage_locked);
2756 
2757 /*
2758  *      Default Socket Callbacks
2759  */
2760 
2761 static void sock_def_wakeup(struct sock *sk)
2762 {
2763         struct socket_wq *wq;
2764 
2765         rcu_read_lock();
2766         wq = rcu_dereference(sk->sk_wq);
2767         if (skwq_has_sleeper(wq))
2768                 wake_up_interruptible_all(&wq->wait);
2769         rcu_read_unlock();
2770 }
2771 
2772 static void sock_def_error_report(struct sock *sk)
2773 {
2774         struct socket_wq *wq;
2775 
2776         rcu_read_lock();
2777         wq = rcu_dereference(sk->sk_wq);
2778         if (skwq_has_sleeper(wq))
2779                 wake_up_interruptible_poll(&wq->wait, EPOLLERR);
2780         sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2781         rcu_read_unlock();
2782 }
2783 
2784 static void sock_def_readable(struct sock *sk)
2785 {
2786         struct socket_wq *wq;
2787 
2788         rcu_read_lock();
2789         wq = rcu_dereference(sk->sk_wq);
2790         if (skwq_has_sleeper(wq))
2791                 wake_up_interruptible_sync_poll(&wq->wait, EPOLLIN | EPOLLPRI |
2792                                                 EPOLLRDNORM | EPOLLRDBAND);
2793         sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2794         rcu_read_unlock();
2795 }
2796 
2797 static void sock_def_write_space(struct sock *sk)
2798 {
2799         struct socket_wq *wq;
2800 
2801         rcu_read_lock();
2802 
2803         /* Do not wake up a writer until he can make "significant"
2804          * progress.  --DaveM
2805          */
2806         if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2807                 wq = rcu_dereference(sk->sk_wq);
2808                 if (skwq_has_sleeper(wq))
2809                         wake_up_interruptible_sync_poll(&wq->wait, EPOLLOUT |
2810                                                 EPOLLWRNORM | EPOLLWRBAND);
2811 
2812                 /* Should agree with poll, otherwise some programs break */
2813                 if (sock_writeable(sk))
2814                         sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2815         }
2816 
2817         rcu_read_unlock();
2818 }
2819 
2820 static void sock_def_destruct(struct sock *sk)
2821 {
2822 }
2823 
2824 void sk_send_sigurg(struct sock *sk)
2825 {
2826         if (sk->sk_socket && sk->sk_socket->file)
2827                 if (send_sigurg(&sk->sk_socket->file->f_owner))
2828                         sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2829 }
2830 EXPORT_SYMBOL(sk_send_sigurg);
2831 
2832 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2833                     unsigned long expires)
2834 {
2835         if (!mod_timer(timer, expires))
2836                 sock_hold(sk);
2837 }
2838 EXPORT_SYMBOL(sk_reset_timer);
2839 
2840 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2841 {
2842         if (del_timer(timer))
2843                 __sock_put(sk);
2844 }
2845 EXPORT_SYMBOL(sk_stop_timer);
2846 
2847 void sock_init_data(struct socket *sock, struct sock *sk)
2848 {
2849         sk_init_common(sk);
2850         sk->sk_send_head        =       NULL;
2851 
2852         timer_setup(&sk->sk_timer, NULL, 0);
2853 
2854         sk->sk_allocation       =       GFP_KERNEL;
2855         sk->sk_rcvbuf           =       sysctl_rmem_default;
2856         sk->sk_sndbuf           =       sysctl_wmem_default;
2857         sk->sk_state            =       TCP_CLOSE;
2858         sk_set_socket(sk, sock);
2859 
2860         sock_set_flag(sk, SOCK_ZAPPED);
2861 
2862         if (sock) {
2863                 sk->sk_type     =       sock->type;
2864                 RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
2865                 sock->sk        =       sk;
2866                 sk->sk_uid      =       SOCK_INODE(sock)->i_uid;
2867         } else {
2868                 RCU_INIT_POINTER(sk->sk_wq, NULL);
2869                 sk->sk_uid      =       make_kuid(sock_net(sk)->user_ns, 0);
2870         }
2871 
2872         rwlock_init(&sk->sk_callback_lock);
2873         if (sk->sk_kern_sock)
2874                 lockdep_set_class_and_name(
2875                         &sk->sk_callback_lock,
2876                         af_kern_callback_keys + sk->sk_family,
2877                         af_family_kern_clock_key_strings[sk->sk_family]);
2878         else
2879                 lockdep_set_class_and_name(
2880                         &sk->sk_callback_lock,
2881                         af_callback_keys + sk->sk_family,
2882                         af_family_clock_key_strings[sk->sk_family]);
2883 
2884         sk->sk_state_change     =       sock_def_wakeup;
2885         sk->sk_data_ready       =       sock_def_readable;
2886         sk->sk_write_space      =       sock_def_write_space;
2887         sk->sk_error_report     =       sock_def_error_report;
2888         sk->sk_destruct         =       sock_def_destruct;
2889 
2890         sk->sk_frag.page        =       NULL;
2891         sk->sk_frag.offset      =       0;
2892         sk->sk_peek_off         =       -1;
2893 
2894         sk->sk_peer_pid         =       NULL;
2895         sk->sk_peer_cred        =       NULL;
2896         sk->sk_write_pending    =       0;
2897         sk->sk_rcvlowat         =       1;
2898         sk->sk_rcvtimeo         =       MAX_SCHEDULE_TIMEOUT;
2899         sk->sk_sndtimeo         =       MAX_SCHEDULE_TIMEOUT;
2900 
2901         sk->sk_stamp = SK_DEFAULT_STAMP;
2902 #if BITS_PER_LONG==32
2903         seqlock_init(&sk->sk_stamp_seq);
2904 #endif
2905         atomic_set(&sk->sk_zckey, 0);
2906 
2907 #ifdef CONFIG_NET_RX_BUSY_POLL
2908         sk->sk_napi_id          =       0;
2909         sk->sk_ll_usec          =       sysctl_net_busy_read;
2910 #endif
2911 
2912         sk->sk_max_pacing_rate = ~0UL;
2913         sk->sk_pacing_rate = ~0UL;
2914         sk->sk_pacing_shift = 10;
2915         sk->sk_incoming_cpu = -1;
2916 
2917         sk_rx_queue_clear(sk);
2918         /*
2919          * Before updating sk_refcnt, we must commit prior changes to memory
2920          * (Documentation/RCU/rculist_nulls.txt for details)
2921          */
2922         smp_wmb();
2923         refcount_set(&sk->sk_refcnt, 1);
2924         atomic_set(&sk->sk_drops, 0);
2925 }
2926 EXPORT_SYMBOL(sock_init_data);
2927 
2928 void lock_sock_nested(struct sock *sk, int subclass)
2929 {
2930         might_sleep();
2931         spin_lock_bh(&sk->sk_lock.slock);
2932         if (sk->sk_lock.owned)
2933                 __lock_sock(sk);
2934         sk->sk_lock.owned = 1;
2935         spin_unlock(&sk->sk_lock.slock);
2936         /*
2937          * The sk_lock has mutex_lock() semantics here:
2938          */
2939         mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2940         local_bh_enable();
2941 }
2942 EXPORT_SYMBOL(lock_sock_nested);
2943 
2944 void release_sock(struct sock *sk)
2945 {
2946         spin_lock_bh(&sk->sk_lock.slock);
2947         if (sk->sk_backlog.tail)
2948                 __release_sock(sk);
2949 
2950         /* Warning : release_cb() might need to release sk ownership,
2951          * ie call sock_release_ownership(sk) before us.
2952          */
2953         if (sk->sk_prot->release_cb)
2954                 sk->sk_prot->release_cb(sk);
2955 
2956         sock_release_ownership(sk);
2957         if (waitqueue_active(&sk->sk_lock.wq))
2958                 wake_up(&sk->sk_lock.wq);
2959         spin_unlock_bh(&sk->sk_lock.slock);
2960 }
2961 EXPORT_SYMBOL(release_sock);
2962 
2963 /**
2964  * lock_sock_fast - fast version of lock_sock
2965  * @sk: socket
2966  *
2967  * This version should be used for very small section, where process wont block
2968  * return false if fast path is taken:
2969  *
2970  *   sk_lock.slock locked, owned = 0, BH disabled
2971  *
2972  * return true if slow path is taken:
2973  *
2974  *   sk_lock.slock unlocked, owned = 1, BH enabled
2975  */
2976 bool lock_sock_fast(struct sock *sk)
2977 {
2978         might_sleep();
2979         spin_lock_bh(&sk->sk_lock.slock);
2980 
2981         if (!sk->sk_lock.owned)
2982                 /*
2983                  * Note : We must disable BH
2984                  */
2985                 return false;
2986 
2987         __lock_sock(sk);
2988         sk->sk_lock.owned = 1;
2989         spin_unlock(&sk->sk_lock.slock);
2990         /*
2991          * The sk_lock has mutex_lock() semantics here:
2992          */
2993         mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2994         local_bh_enable();
2995         return true;
2996 }
2997 EXPORT_SYMBOL(lock_sock_fast);
2998 
2999 int sock_gettstamp(struct socket *sock, void __user *userstamp,
3000                    bool timeval, bool time32)
3001 {
3002         struct sock *sk = sock->sk;
3003         struct timespec64 ts;
3004 
3005         sock_enable_timestamp(sk, SOCK_TIMESTAMP);
3006         ts = ktime_to_timespec64(sock_read_timestamp(sk));
3007         if (ts.tv_sec == -1)
3008                 return -ENOENT;
3009         if (ts.tv_sec == 0) {
3010                 ktime_t kt = ktime_get_real();
3011                 sock_write_timestamp(sk, kt);;
3012                 ts = ktime_to_timespec64(kt);
3013         }
3014 
3015         if (timeval)
3016                 ts.tv_nsec /= 1000;
3017 
3018 #ifdef CONFIG_COMPAT_32BIT_TIME
3019         if (time32)
3020                 return put_old_timespec32(&ts, userstamp);
3021 #endif
3022 #ifdef CONFIG_SPARC64
3023         /* beware of padding in sparc64 timeval */
3024         if (timeval && !in_compat_syscall()) {
3025                 struct __kernel_old_timeval __user tv = {
3026                         .tv_sec = ts.tv_sec,
3027                         .tv_usec = ts.tv_nsec,
3028                 };
3029                 if (copy_to_user(userstamp, &tv, sizeof(tv)))
3030                         return -EFAULT;
3031                 return 0;
3032         }
3033 #endif
3034         return put_timespec64(&ts, userstamp);
3035 }
3036 EXPORT_SYMBOL(sock_gettstamp);
3037 
3038 void sock_enable_timestamp(struct sock *sk, int flag)
3039 {
3040         if (!sock_flag(sk, flag)) {
3041                 unsigned long previous_flags = sk->sk_flags;
3042 
3043                 sock_set_flag(sk, flag);
3044                 /*
3045                  * we just set one of the two flags which require net
3046                  * time stamping, but time stamping might have been on
3047                  * already because of the other one
3048                  */
3049                 if (sock_needs_netstamp(sk) &&
3050                     !(previous_flags & SK_FLAGS_TIMESTAMP))
3051                         net_enable_timestamp();
3052         }
3053 }
3054 
3055 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
3056                        int level, int type)
3057 {
3058         struct sock_exterr_skb *serr;
3059         struct sk_buff *skb;
3060         int copied, err;
3061 
3062         err = -EAGAIN;
3063         skb = sock_dequeue_err_skb(sk);
3064         if (skb == NULL)
3065                 goto out;
3066 
3067         copied = skb->len;
3068         if (copied > len) {
3069                 msg->msg_flags |= MSG_TRUNC;
3070                 copied = len;
3071         }
3072         err = skb_copy_datagram_msg(skb, 0, msg, copied);
3073         if (err)
3074                 goto out_free_skb;
3075 
3076         sock_recv_timestamp(msg, sk, skb);
3077 
3078         serr = SKB_EXT_ERR(skb);
3079         put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
3080 
3081         msg->msg_flags |= MSG_ERRQUEUE;
3082         err = copied;
3083 
3084 out_free_skb:
3085         kfree_skb(skb);
3086 out:
3087         return err;
3088 }
3089 EXPORT_SYMBOL(sock_recv_errqueue);
3090 
3091 /*
3092  *      Get a socket option on an socket.
3093  *
3094  *      FIX: POSIX 1003.1g is very ambiguous here. It states that
3095  *      asynchronous errors should be reported by getsockopt. We assume
3096  *      this means if you specify SO_ERROR (otherwise whats the point of it).
3097  */
3098 int sock_common_getsockopt(struct socket *sock, int level, int optname,
3099                            char __user *optval, int __user *optlen)
3100 {
3101         struct sock *sk = sock->sk;
3102 
3103         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3104 }
3105 EXPORT_SYMBOL(sock_common_getsockopt);
3106 
3107 #ifdef CONFIG_COMPAT
3108 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
3109                                   char __user *optval, int __user *optlen)
3110 {
3111         struct sock *sk = sock->sk;
3112 
3113         if (sk->sk_prot->compat_getsockopt != NULL)
3114                 return sk->sk_prot->compat_getsockopt(sk, level, optname,
3115                                                       optval, optlen);
3116         return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
3117 }
3118 EXPORT_SYMBOL(compat_sock_common_getsockopt);
3119 #endif
3120 
3121 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
3122                         int flags)
3123 {
3124         struct sock *sk = sock->sk;
3125         int addr_len = 0;
3126         int err;
3127 
3128         err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
3129                                    flags & ~MSG_DONTWAIT, &addr_len);
3130         if (err >= 0)
3131                 msg->msg_namelen = addr_len;
3132         return err;
3133 }
3134 EXPORT_SYMBOL(sock_common_recvmsg);
3135 
3136 /*
3137  *      Set socket options on an inet socket.
3138  */
3139 int sock_common_setsockopt(struct socket *sock, int level, int optname,
3140                            char __user *optval, unsigned int optlen)
3141 {
3142         struct sock *sk = sock->sk;
3143 
3144         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3145 }
3146 EXPORT_SYMBOL(sock_common_setsockopt);
3147 
3148 #ifdef CONFIG_COMPAT
3149 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
3150                                   char __user *optval, unsigned int optlen)
3151 {
3152         struct sock *sk = sock->sk;
3153 
3154         if (sk->sk_prot->compat_setsockopt != NULL)
3155                 return sk->sk_prot->compat_setsockopt(sk, level, optname,
3156                                                       optval, optlen);
3157         return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
3158 }
3159 EXPORT_SYMBOL(compat_sock_common_setsockopt);
3160 #endif
3161 
3162 void sk_common_release(struct sock *sk)
3163 {
3164         if (sk->sk_prot->destroy)
3165                 sk->sk_prot->destroy(sk);
3166 
3167         /*
3168          * Observation: when sock_common_release is called, processes have
3169          * no access to socket. But net still has.
3170          * Step one, detach it from networking:
3171          *
3172          * A. Remove from hash tables.
3173          */
3174 
3175         sk->sk_prot->unhash(sk);
3176 
3177         /*
3178          * In this point socket cannot receive new packets, but it is possible
3179          * that some packets are in flight because some CPU runs receiver and
3180          * did hash table lookup before we unhashed socket. They will achieve
3181          * receive queue and will be purged by socket destructor.
3182          *
3183          * Also we still have packets pending on receive queue and probably,
3184          * our own packets waiting in device queues. sock_destroy will drain
3185          * receive queue, but transmitted packets will delay socket destruction
3186          * until the last reference will be released.
3187          */
3188 
3189         sock_orphan(sk);
3190 
3191         xfrm_sk_free_policy(sk);
3192 
3193         sk_refcnt_debug_release(sk);
3194 
3195         sock_put(sk);
3196 }
3197 EXPORT_SYMBOL(sk_common_release);
3198 
3199 void sk_get_meminfo(const struct sock *sk, u32 *mem)
3200 {
3201         memset(mem, 0, sizeof(*mem) * SK_MEMINFO_VARS);
3202 
3203         mem[SK_MEMINFO_RMEM_ALLOC] = sk_rmem_alloc_get(sk);
3204         mem[SK_MEMINFO_RCVBUF] = sk->sk_rcvbuf;
3205         mem[SK_MEMINFO_WMEM_ALLOC] = sk_wmem_alloc_get(sk);
3206         mem[SK_MEMINFO_SNDBUF] = sk->sk_sndbuf;
3207         mem[SK_MEMINFO_FWD_ALLOC] = sk->sk_forward_alloc;
3208         mem[SK_MEMINFO_WMEM_QUEUED] = sk->sk_wmem_queued;
3209         mem[SK_MEMINFO_OPTMEM] = atomic_read(&sk->sk_omem_alloc);
3210         mem[SK_MEMINFO_BACKLOG] = sk->sk_backlog.len;
3211         mem[SK_MEMINFO_DROPS] = atomic_read(&sk->sk_drops);
3212 }
3213 
3214 #ifdef CONFIG_PROC_FS
3215 #define PROTO_INUSE_NR  64      /* should be enough for the first time */
3216 struct prot_inuse {
3217         int val[PROTO_INUSE_NR];
3218 };
3219 
3220 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
3221 
3222 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
3223 {
3224         __this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
3225 }
3226 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
3227 
3228 int sock_prot_inuse_get(struct net *net, struct proto *prot)
3229 {
3230         int cpu, idx = prot->inuse_idx;
3231         int res = 0;
3232 
3233         for_each_possible_cpu(cpu)
3234                 res += per_cpu_ptr(net->core.prot_inuse, cpu)->val[idx];
3235 
3236         return res >= 0 ? res : 0;
3237 }
3238 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
3239 
3240 static void sock_inuse_add(struct net *net, int val)
3241 {
3242         this_cpu_add(*net->core.sock_inuse, val);
3243 }
3244 
3245 int sock_inuse_get(struct net *net)
3246 {
3247         int cpu, res = 0;
3248 
3249         for_each_possible_cpu(cpu)
3250                 res += *per_cpu_ptr(net->core.sock_inuse, cpu);
3251 
3252         return res;
3253 }
3254 
3255 EXPORT_SYMBOL_GPL(sock_inuse_get);
3256 
3257 static int __net_init sock_inuse_init_net(struct net *net)
3258 {
3259         net->core.prot_inuse = alloc_percpu(struct prot_inuse);
3260         if (net->core.prot_inuse == NULL)
3261                 return -ENOMEM;
3262 
3263         net->core.sock_inuse = alloc_percpu(int);
3264         if (net->core.sock_inuse == NULL)
3265                 goto out;
3266 
3267         return 0;
3268 
3269 out:
3270         free_percpu(net->core.prot_inuse);
3271         return -ENOMEM;
3272 }
3273 
3274 static void __net_exit sock_inuse_exit_net(struct net *net)
3275 {
3276         free_percpu(net->core.prot_inuse);
3277         free_percpu(net->core.sock_inuse);
3278 }
3279 
3280 static struct pernet_operations net_inuse_ops = {
3281         .init = sock_inuse_init_net,
3282         .exit = sock_inuse_exit_net,
3283 };
3284 
3285 static __init int net_inuse_init(void)
3286 {
3287         if (register_pernet_subsys(&net_inuse_ops))
3288                 panic("Cannot initialize net inuse counters");
3289 
3290         return 0;
3291 }
3292 
3293 core_initcall(net_inuse_init);
3294 
3295 static int assign_proto_idx(struct proto *prot)
3296 {
3297         prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
3298 
3299         if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
3300                 pr_err("PROTO_INUSE_NR exhausted\n");
3301                 return -ENOSPC;
3302         }
3303 
3304         set_bit(prot->inuse_idx, proto_inuse_idx);
3305         return 0;
3306 }
3307 
3308 static void release_proto_idx(struct proto *prot)
3309 {
3310         if (prot->inuse_idx != PROTO_INUSE_NR - 1)
3311                 clear_bit(prot->inuse_idx, proto_inuse_idx);
3312 }
3313 #else
3314 static inline int assign_proto_idx(struct proto *prot)
3315 {
3316         return 0;
3317 }
3318 
3319 static inline void release_proto_idx(struct proto *prot)
3320 {
3321 }
3322 
3323 static void sock_inuse_add(struct net *net, int val)
3324 {
3325 }
3326 #endif
3327 
3328 static void req_prot_cleanup(struct request_sock_ops *rsk_prot)
3329 {
3330         if (!rsk_prot)
3331                 return;
3332         kfree(rsk_prot->slab_name);
3333         rsk_prot->slab_name = NULL;
3334         kmem_cache_destroy(rsk_prot->slab);
3335         rsk_prot->slab = NULL;
3336 }
3337 
3338 static int req_prot_init(const struct proto *prot)
3339 {
3340         struct request_sock_ops *rsk_prot = prot->rsk_prot;
3341 
3342         if (!rsk_prot)
3343                 return 0;
3344 
3345         rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s",
3346                                         prot->name);
3347         if (!rsk_prot->slab_name)
3348                 return -ENOMEM;
3349 
3350         rsk_prot->slab = kmem_cache_create(rsk_prot->slab_name,
3351                                            rsk_prot->obj_size, 0,
3352                                            SLAB_ACCOUNT | prot->slab_flags,
3353                                            NULL);
3354 
3355         if (!rsk_prot->slab) {
3356                 pr_crit("%s: Can't create request sock SLAB cache!\n",
3357                         prot->name);
3358                 return -ENOMEM;
3359         }
3360         return 0;
3361 }
3362 
3363 int proto_register(struct proto *prot, int alloc_slab)
3364 {
3365         int ret = -ENOBUFS;
3366 
3367         if (alloc_slab) {
3368                 prot->slab = kmem_cache_create_usercopy(prot->name,
3369                                         prot->obj_size, 0,
3370                                         SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT |
3371                                         prot->slab_flags,
3372                                         prot->useroffset, prot->usersize,
3373                                         NULL);
3374 
3375                 if (prot->slab == NULL) {
3376                         pr_crit("%s: Can't create sock SLAB cache!\n",
3377                                 prot->name);
3378                         goto out;
3379                 }
3380 
3381                 if (req_prot_init(prot))
3382                         goto out_free_request_sock_slab;
3383 
3384                 if (prot->twsk_prot != NULL) {
3385                         prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
3386 
3387                         if (prot->twsk_prot->twsk_slab_name == NULL)
3388                                 goto out_free_request_sock_slab;
3389 
3390                         prot->twsk_prot->twsk_slab =
3391                                 kmem_cache_create(prot->twsk_prot->twsk_slab_name,
3392                                                   prot->twsk_prot->twsk_obj_size,
3393                                                   0,
3394                                                   SLAB_ACCOUNT |
3395                                                   prot->slab_flags,
3396                                                   NULL);
3397                         if (prot->twsk_prot->twsk_slab == NULL)
3398                                 goto out_free_timewait_sock_slab_name;
3399                 }
3400         }
3401 
3402         mutex_lock(&proto_list_mutex);
3403         ret = assign_proto_idx(prot);
3404         if (ret) {
3405                 mutex_unlock(&proto_list_mutex);
3406                 goto out_free_timewait_sock_slab_name;
3407         }
3408         list_add(&prot->node, &proto_list);
3409         mutex_unlock(&proto_list_mutex);
3410         return ret;
3411 
3412 out_free_timewait_sock_slab_name:
3413         if (alloc_slab && prot->twsk_prot)
3414                 kfree(prot->twsk_prot->twsk_slab_name);
3415 out_free_request_sock_slab:
3416         if (alloc_slab) {
3417                 req_prot_cleanup(prot->rsk_prot);
3418 
3419                 kmem_cache_destroy(prot->slab);
3420                 prot->slab = NULL;
3421         }
3422 out:
3423         return ret;
3424 }
3425 EXPORT_SYMBOL(proto_register);
3426 
3427 void proto_unregister(struct proto *prot)
3428 {
3429         mutex_lock(&proto_list_mutex);
3430         release_proto_idx(prot);
3431         list_del(&prot->node);
3432         mutex_unlock(&proto_list_mutex);
3433 
3434         kmem_cache_destroy(prot->slab);
3435         prot->slab = NULL;
3436 
3437         req_prot_cleanup(prot->rsk_prot);
3438 
3439         if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
3440                 kmem_cache_destroy(prot->twsk_prot->twsk_slab);
3441                 kfree(prot->twsk_prot->twsk_slab_name);
3442                 prot->twsk_prot->twsk_slab = NULL;
3443         }
3444 }
3445 EXPORT_SYMBOL(proto_unregister);
3446 
3447 int sock_load_diag_module(int family, int protocol)
3448 {
3449         if (!protocol) {
3450                 if (!sock_is_registered(family))
3451                         return -ENOENT;
3452 
3453                 return request_module("net-pf-%d-proto-%d-type-%d", PF_NETLINK,
3454                                       NETLINK_SOCK_DIAG, family);
3455         }
3456 
3457 #ifdef CONFIG_INET
3458         if (family == AF_INET &&
3459             protocol != IPPROTO_RAW &&
3460             !rcu_access_pointer(inet_protos[protocol]))
3461                 return -ENOENT;
3462 #endif
3463 
3464         return request_module("net-pf-%d-proto-%d-type-%d-%d", PF_NETLINK,
3465                               NETLINK_SOCK_DIAG, family, protocol);
3466 }
3467 EXPORT_SYMBOL(sock_load_diag_module);
3468 
3469 #ifdef CONFIG_PROC_FS
3470 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
3471         __acquires(proto_list_mutex)
3472 {
3473         mutex_lock(&proto_list_mutex);
3474         return seq_list_start_head(&proto_list, *pos);
3475 }
3476 
3477 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
3478 {
3479         return seq_list_next(v, &proto_list, pos);
3480 }
3481 
3482 static void proto_seq_stop(struct seq_file *seq, void *v)
3483         __releases(proto_list_mutex)
3484 {
3485         mutex_unlock(&proto_list_mutex);
3486 }
3487 
3488 static char proto_method_implemented(const void *method)
3489 {
3490         return method == NULL ? 'n' : 'y';
3491 }
3492 static long sock_prot_memory_allocated(struct proto *proto)
3493 {
3494         return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
3495 }
3496 
3497 static char *sock_prot_memory_pressure(struct proto *proto)
3498 {
3499         return proto->memory_pressure != NULL ?
3500         proto_memory_pressure(proto) ? "yes" : "no" : "NI";
3501 }
3502 
3503 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
3504 {
3505 
3506         seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
3507                         "%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
3508                    proto->name,
3509                    proto->obj_size,
3510                    sock_prot_inuse_get(seq_file_net(seq), proto),
3511                    sock_prot_memory_allocated(proto),
3512                    sock_prot_memory_pressure(proto),
3513                    proto->max_header,
3514                    proto->slab == NULL ? "no" : "yes",
3515                    module_name(proto->owner),
3516                    proto_method_implemented(proto->close),
3517                    proto_method_implemented(proto->connect),
3518                    proto_method_implemented(proto->disconnect),
3519                    proto_method_implemented(proto->accept),
3520                    proto_method_implemented(proto->ioctl),
3521                    proto_method_implemented(proto->init),
3522                    proto_method_implemented(proto->destroy),
3523                    proto_method_implemented(proto->shutdown),
3524                    proto_method_implemented(proto->setsockopt),
3525                    proto_method_implemented(proto->getsockopt),
3526                    proto_method_implemented(proto->sendmsg),
3527                    proto_method_implemented(proto->recvmsg),
3528                    proto_method_implemented(proto->sendpage),
3529                    proto_method_implemented(proto->bind),
3530                    proto_method_implemented(proto->backlog_rcv),
3531                    proto_method_implemented(proto->hash),
3532                    proto_method_implemented(proto->unhash),
3533                    proto_method_implemented(proto->get_port),
3534                    proto_method_implemented(proto->enter_memory_pressure));
3535 }
3536 
3537 static int proto_seq_show(struct seq_file *seq, void *v)
3538 {
3539         if (v == &proto_list)
3540                 seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
3541                            "protocol",
3542                            "size",
3543                            "sockets",
3544                            "memory",
3545                            "press",
3546                            "maxhdr",
3547                            "slab",
3548                            "module",
3549                            "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
3550         else
3551                 proto_seq_printf(seq, list_entry(v, struct proto, node));
3552         return 0;
3553 }
3554 
3555 static const struct seq_operations proto_seq_ops = {
3556         .start  = proto_seq_start,
3557         .next   = proto_seq_next,
3558         .stop   = proto_seq_stop,
3559         .show   = proto_seq_show,
3560 };
3561 
3562 static __net_init int proto_init_net(struct net *net)
3563 {
3564         if (!proc_create_net("protocols", 0444, net->proc_net, &proto_seq_ops,
3565                         sizeof(struct seq_net_private)))
3566                 return -ENOMEM;
3567 
3568         return 0;
3569 }
3570 
3571 static __net_exit void proto_exit_net(struct net *net)
3572 {
3573         remove_proc_entry("protocols", net->proc_net);
3574 }
3575 
3576 
3577 static __net_initdata struct pernet_operations proto_net_ops = {
3578         .init = proto_init_net,
3579         .exit = proto_exit_net,
3580 };
3581 
3582 static int __init proto_init(void)
3583 {
3584         return register_pernet_subsys(&proto_net_ops);
3585 }
3586 
3587 subsys_initcall(proto_init);
3588 
3589 #endif /* PROC_FS */
3590 
3591 #ifdef CONFIG_NET_RX_BUSY_POLL
3592 bool sk_busy_loop_end(void *p, unsigned long start_time)
3593 {
3594         struct sock *sk = p;
3595 
3596         return !skb_queue_empty_lockless(&sk->sk_receive_queue) ||
3597                sk_busy_loop_timeout(sk, start_time);
3598 }
3599 EXPORT_SYMBOL(sk_busy_loop_end);
3600 #endif /* CONFIG_NET_RX_BUSY_POLL */
3601 

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