xref: /linux/net/core/sock.c (revision 957e3facd147510f2cf8780e38606f1d707f0e33)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Generic socket support routines. Memory allocators, socket lock/release
7  *		handler for protocols to use and generic option handler.
8  *
9  *
10  * Authors:	Ross Biro
11  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *		Florian La Roche, <flla@stud.uni-sb.de>
13  *		Alan Cox, <A.Cox@swansea.ac.uk>
14  *
15  * Fixes:
16  *		Alan Cox	: 	Numerous verify_area() problems
17  *		Alan Cox	:	Connecting on a connecting socket
18  *					now returns an error for tcp.
19  *		Alan Cox	:	sock->protocol is set correctly.
20  *					and is not sometimes left as 0.
21  *		Alan Cox	:	connect handles icmp errors on a
22  *					connect properly. Unfortunately there
23  *					is a restart syscall nasty there. I
24  *					can't match BSD without hacking the C
25  *					library. Ideas urgently sought!
26  *		Alan Cox	:	Disallow bind() to addresses that are
27  *					not ours - especially broadcast ones!!
28  *		Alan Cox	:	Socket 1024 _IS_ ok for users. (fencepost)
29  *		Alan Cox	:	sock_wfree/sock_rfree don't destroy sockets,
30  *					instead they leave that for the DESTROY timer.
31  *		Alan Cox	:	Clean up error flag in accept
32  *		Alan Cox	:	TCP ack handling is buggy, the DESTROY timer
33  *					was buggy. Put a remove_sock() in the handler
34  *					for memory when we hit 0. Also altered the timer
35  *					code. The ACK stuff can wait and needs major
36  *					TCP layer surgery.
37  *		Alan Cox	:	Fixed TCP ack bug, removed remove sock
38  *					and fixed timer/inet_bh race.
39  *		Alan Cox	:	Added zapped flag for TCP
40  *		Alan Cox	:	Move kfree_skb into skbuff.c and tidied up surplus code
41  *		Alan Cox	:	for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
42  *		Alan Cox	:	kfree_s calls now are kfree_skbmem so we can track skb resources
43  *		Alan Cox	:	Supports socket option broadcast now as does udp. Packet and raw need fixing.
44  *		Alan Cox	:	Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
45  *		Rick Sladkey	:	Relaxed UDP rules for matching packets.
46  *		C.E.Hawkins	:	IFF_PROMISC/SIOCGHWADDR support
47  *	Pauline Middelink	:	identd support
48  *		Alan Cox	:	Fixed connect() taking signals I think.
49  *		Alan Cox	:	SO_LINGER supported
50  *		Alan Cox	:	Error reporting fixes
51  *		Anonymous	:	inet_create tidied up (sk->reuse setting)
52  *		Alan Cox	:	inet sockets don't set sk->type!
53  *		Alan Cox	:	Split socket option code
54  *		Alan Cox	:	Callbacks
55  *		Alan Cox	:	Nagle flag for Charles & Johannes stuff
56  *		Alex		:	Removed restriction on inet fioctl
57  *		Alan Cox	:	Splitting INET from NET core
58  *		Alan Cox	:	Fixed bogus SO_TYPE handling in getsockopt()
59  *		Adam Caldwell	:	Missing return in SO_DONTROUTE/SO_DEBUG code
60  *		Alan Cox	:	Split IP from generic code
61  *		Alan Cox	:	New kfree_skbmem()
62  *		Alan Cox	:	Make SO_DEBUG superuser only.
63  *		Alan Cox	:	Allow anyone to clear SO_DEBUG
64  *					(compatibility fix)
65  *		Alan Cox	:	Added optimistic memory grabbing for AF_UNIX throughput.
66  *		Alan Cox	:	Allocator for a socket is settable.
67  *		Alan Cox	:	SO_ERROR includes soft errors.
68  *		Alan Cox	:	Allow NULL arguments on some SO_ opts
69  *		Alan Cox	: 	Generic socket allocation to make hooks
70  *					easier (suggested by Craig Metz).
71  *		Michael Pall	:	SO_ERROR returns positive errno again
72  *              Steve Whitehouse:       Added default destructor to free
73  *                                      protocol private data.
74  *              Steve Whitehouse:       Added various other default routines
75  *                                      common to several socket families.
76  *              Chris Evans     :       Call suser() check last on F_SETOWN
77  *		Jay Schulist	:	Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
78  *		Andi Kleen	:	Add sock_kmalloc()/sock_kfree_s()
79  *		Andi Kleen	:	Fix write_space callback
80  *		Chris Evans	:	Security fixes - signedness again
81  *		Arnaldo C. Melo :       cleanups, use skb_queue_purge
82  *
83  * To Fix:
84  *
85  *
86  *		This program is free software; you can redistribute it and/or
87  *		modify it under the terms of the GNU General Public License
88  *		as published by the Free Software Foundation; either version
89  *		2 of the License, or (at your option) any later version.
90  */
91 
92 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
93 
94 #include <linux/capability.h>
95 #include <linux/errno.h>
96 #include <linux/errqueue.h>
97 #include <linux/types.h>
98 #include <linux/socket.h>
99 #include <linux/in.h>
100 #include <linux/kernel.h>
101 #include <linux/module.h>
102 #include <linux/proc_fs.h>
103 #include <linux/seq_file.h>
104 #include <linux/sched.h>
105 #include <linux/timer.h>
106 #include <linux/string.h>
107 #include <linux/sockios.h>
108 #include <linux/net.h>
109 #include <linux/mm.h>
110 #include <linux/slab.h>
111 #include <linux/interrupt.h>
112 #include <linux/poll.h>
113 #include <linux/tcp.h>
114 #include <linux/init.h>
115 #include <linux/highmem.h>
116 #include <linux/user_namespace.h>
117 #include <linux/static_key.h>
118 #include <linux/memcontrol.h>
119 #include <linux/prefetch.h>
120 
121 #include <asm/uaccess.h>
122 
123 #include <linux/netdevice.h>
124 #include <net/protocol.h>
125 #include <linux/skbuff.h>
126 #include <net/net_namespace.h>
127 #include <net/request_sock.h>
128 #include <net/sock.h>
129 #include <linux/net_tstamp.h>
130 #include <net/xfrm.h>
131 #include <linux/ipsec.h>
132 #include <net/cls_cgroup.h>
133 #include <net/netprio_cgroup.h>
134 
135 #include <linux/filter.h>
136 
137 #include <trace/events/sock.h>
138 
139 #ifdef CONFIG_INET
140 #include <net/tcp.h>
141 #endif
142 
143 #include <net/busy_poll.h>
144 
145 static DEFINE_MUTEX(proto_list_mutex);
146 static LIST_HEAD(proto_list);
147 
148 /**
149  * sk_ns_capable - General socket capability test
150  * @sk: Socket to use a capability on or through
151  * @user_ns: The user namespace of the capability to use
152  * @cap: The capability to use
153  *
154  * Test to see if the opener of the socket had when the socket was
155  * created and the current process has the capability @cap in the user
156  * namespace @user_ns.
157  */
158 bool sk_ns_capable(const struct sock *sk,
159 		   struct user_namespace *user_ns, int cap)
160 {
161 	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
162 		ns_capable(user_ns, cap);
163 }
164 EXPORT_SYMBOL(sk_ns_capable);
165 
166 /**
167  * sk_capable - Socket global capability test
168  * @sk: Socket to use a capability on or through
169  * @cap: The global capability to use
170  *
171  * Test to see if the opener of the socket had when the socket was
172  * created and the current process has the capability @cap in all user
173  * namespaces.
174  */
175 bool sk_capable(const struct sock *sk, int cap)
176 {
177 	return sk_ns_capable(sk, &init_user_ns, cap);
178 }
179 EXPORT_SYMBOL(sk_capable);
180 
181 /**
182  * sk_net_capable - Network namespace socket capability test
183  * @sk: Socket to use a capability on or through
184  * @cap: The capability to use
185  *
186  * Test to see if the opener of the socket had when the socket was created
187  * and the current process has the capability @cap over the network namespace
188  * the socket is a member of.
189  */
190 bool sk_net_capable(const struct sock *sk, int cap)
191 {
192 	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
193 }
194 EXPORT_SYMBOL(sk_net_capable);
195 
196 
197 #ifdef CONFIG_MEMCG_KMEM
198 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
199 {
200 	struct proto *proto;
201 	int ret = 0;
202 
203 	mutex_lock(&proto_list_mutex);
204 	list_for_each_entry(proto, &proto_list, node) {
205 		if (proto->init_cgroup) {
206 			ret = proto->init_cgroup(memcg, ss);
207 			if (ret)
208 				goto out;
209 		}
210 	}
211 
212 	mutex_unlock(&proto_list_mutex);
213 	return ret;
214 out:
215 	list_for_each_entry_continue_reverse(proto, &proto_list, node)
216 		if (proto->destroy_cgroup)
217 			proto->destroy_cgroup(memcg);
218 	mutex_unlock(&proto_list_mutex);
219 	return ret;
220 }
221 
222 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
223 {
224 	struct proto *proto;
225 
226 	mutex_lock(&proto_list_mutex);
227 	list_for_each_entry_reverse(proto, &proto_list, node)
228 		if (proto->destroy_cgroup)
229 			proto->destroy_cgroup(memcg);
230 	mutex_unlock(&proto_list_mutex);
231 }
232 #endif
233 
234 /*
235  * Each address family might have different locking rules, so we have
236  * one slock key per address family:
237  */
238 static struct lock_class_key af_family_keys[AF_MAX];
239 static struct lock_class_key af_family_slock_keys[AF_MAX];
240 
241 #if defined(CONFIG_MEMCG_KMEM)
242 struct static_key memcg_socket_limit_enabled;
243 EXPORT_SYMBOL(memcg_socket_limit_enabled);
244 #endif
245 
246 /*
247  * Make lock validator output more readable. (we pre-construct these
248  * strings build-time, so that runtime initialization of socket
249  * locks is fast):
250  */
251 static const char *const af_family_key_strings[AF_MAX+1] = {
252   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
253   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
254   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
255   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
256   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
257   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
258   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
259   "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
260   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
261   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
262   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
263   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
264   "sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG"      ,
265   "sk_lock-AF_NFC"   , "sk_lock-AF_VSOCK"    , "sk_lock-AF_MAX"
266 };
267 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
268   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
269   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
270   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
271   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
272   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
273   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
274   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
275   "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
276   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
277   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
278   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
279   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
280   "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG"      ,
281   "slock-AF_NFC"   , "slock-AF_VSOCK"    ,"slock-AF_MAX"
282 };
283 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
284   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
285   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
286   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
287   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
288   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
289   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
290   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
291   "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
292   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
293   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
294   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
295   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
296   "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG"      ,
297   "clock-AF_NFC"   , "clock-AF_VSOCK"    , "clock-AF_MAX"
298 };
299 
300 /*
301  * sk_callback_lock locking rules are per-address-family,
302  * so split the lock classes by using a per-AF key:
303  */
304 static struct lock_class_key af_callback_keys[AF_MAX];
305 
306 /* Take into consideration the size of the struct sk_buff overhead in the
307  * determination of these values, since that is non-constant across
308  * platforms.  This makes socket queueing behavior and performance
309  * not depend upon such differences.
310  */
311 #define _SK_MEM_PACKETS		256
312 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
313 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
314 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
315 
316 /* Run time adjustable parameters. */
317 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
318 EXPORT_SYMBOL(sysctl_wmem_max);
319 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
320 EXPORT_SYMBOL(sysctl_rmem_max);
321 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
322 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
323 
324 /* Maximal space eaten by iovec or ancillary data plus some space */
325 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
326 EXPORT_SYMBOL(sysctl_optmem_max);
327 
328 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
329 EXPORT_SYMBOL_GPL(memalloc_socks);
330 
331 /**
332  * sk_set_memalloc - sets %SOCK_MEMALLOC
333  * @sk: socket to set it on
334  *
335  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
336  * It's the responsibility of the admin to adjust min_free_kbytes
337  * to meet the requirements
338  */
339 void sk_set_memalloc(struct sock *sk)
340 {
341 	sock_set_flag(sk, SOCK_MEMALLOC);
342 	sk->sk_allocation |= __GFP_MEMALLOC;
343 	static_key_slow_inc(&memalloc_socks);
344 }
345 EXPORT_SYMBOL_GPL(sk_set_memalloc);
346 
347 void sk_clear_memalloc(struct sock *sk)
348 {
349 	sock_reset_flag(sk, SOCK_MEMALLOC);
350 	sk->sk_allocation &= ~__GFP_MEMALLOC;
351 	static_key_slow_dec(&memalloc_socks);
352 
353 	/*
354 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
355 	 * progress of swapping. However, if SOCK_MEMALLOC is cleared while
356 	 * it has rmem allocations there is a risk that the user of the
357 	 * socket cannot make forward progress due to exceeding the rmem
358 	 * limits. By rights, sk_clear_memalloc() should only be called
359 	 * on sockets being torn down but warn and reset the accounting if
360 	 * that assumption breaks.
361 	 */
362 	if (WARN_ON(sk->sk_forward_alloc))
363 		sk_mem_reclaim(sk);
364 }
365 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
366 
367 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
368 {
369 	int ret;
370 	unsigned long pflags = current->flags;
371 
372 	/* these should have been dropped before queueing */
373 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
374 
375 	current->flags |= PF_MEMALLOC;
376 	ret = sk->sk_backlog_rcv(sk, skb);
377 	tsk_restore_flags(current, pflags, PF_MEMALLOC);
378 
379 	return ret;
380 }
381 EXPORT_SYMBOL(__sk_backlog_rcv);
382 
383 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
384 {
385 	struct timeval tv;
386 
387 	if (optlen < sizeof(tv))
388 		return -EINVAL;
389 	if (copy_from_user(&tv, optval, sizeof(tv)))
390 		return -EFAULT;
391 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
392 		return -EDOM;
393 
394 	if (tv.tv_sec < 0) {
395 		static int warned __read_mostly;
396 
397 		*timeo_p = 0;
398 		if (warned < 10 && net_ratelimit()) {
399 			warned++;
400 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
401 				__func__, current->comm, task_pid_nr(current));
402 		}
403 		return 0;
404 	}
405 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
406 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
407 		return 0;
408 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
409 		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
410 	return 0;
411 }
412 
413 static void sock_warn_obsolete_bsdism(const char *name)
414 {
415 	static int warned;
416 	static char warncomm[TASK_COMM_LEN];
417 	if (strcmp(warncomm, current->comm) && warned < 5) {
418 		strcpy(warncomm,  current->comm);
419 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
420 			warncomm, name);
421 		warned++;
422 	}
423 }
424 
425 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
426 
427 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
428 {
429 	if (sk->sk_flags & flags) {
430 		sk->sk_flags &= ~flags;
431 		if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
432 			net_disable_timestamp();
433 	}
434 }
435 
436 
437 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
438 {
439 	int err;
440 	unsigned long flags;
441 	struct sk_buff_head *list = &sk->sk_receive_queue;
442 
443 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
444 		atomic_inc(&sk->sk_drops);
445 		trace_sock_rcvqueue_full(sk, skb);
446 		return -ENOMEM;
447 	}
448 
449 	err = sk_filter(sk, skb);
450 	if (err)
451 		return err;
452 
453 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
454 		atomic_inc(&sk->sk_drops);
455 		return -ENOBUFS;
456 	}
457 
458 	skb->dev = NULL;
459 	skb_set_owner_r(skb, sk);
460 
461 	/* we escape from rcu protected region, make sure we dont leak
462 	 * a norefcounted dst
463 	 */
464 	skb_dst_force(skb);
465 
466 	spin_lock_irqsave(&list->lock, flags);
467 	skb->dropcount = atomic_read(&sk->sk_drops);
468 	__skb_queue_tail(list, skb);
469 	spin_unlock_irqrestore(&list->lock, flags);
470 
471 	if (!sock_flag(sk, SOCK_DEAD))
472 		sk->sk_data_ready(sk);
473 	return 0;
474 }
475 EXPORT_SYMBOL(sock_queue_rcv_skb);
476 
477 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
478 {
479 	int rc = NET_RX_SUCCESS;
480 
481 	if (sk_filter(sk, skb))
482 		goto discard_and_relse;
483 
484 	skb->dev = NULL;
485 
486 	if (sk_rcvqueues_full(sk, sk->sk_rcvbuf)) {
487 		atomic_inc(&sk->sk_drops);
488 		goto discard_and_relse;
489 	}
490 	if (nested)
491 		bh_lock_sock_nested(sk);
492 	else
493 		bh_lock_sock(sk);
494 	if (!sock_owned_by_user(sk)) {
495 		/*
496 		 * trylock + unlock semantics:
497 		 */
498 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
499 
500 		rc = sk_backlog_rcv(sk, skb);
501 
502 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
503 	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
504 		bh_unlock_sock(sk);
505 		atomic_inc(&sk->sk_drops);
506 		goto discard_and_relse;
507 	}
508 
509 	bh_unlock_sock(sk);
510 out:
511 	sock_put(sk);
512 	return rc;
513 discard_and_relse:
514 	kfree_skb(skb);
515 	goto out;
516 }
517 EXPORT_SYMBOL(sk_receive_skb);
518 
519 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
520 {
521 	struct dst_entry *dst = __sk_dst_get(sk);
522 
523 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
524 		sk_tx_queue_clear(sk);
525 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
526 		dst_release(dst);
527 		return NULL;
528 	}
529 
530 	return dst;
531 }
532 EXPORT_SYMBOL(__sk_dst_check);
533 
534 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
535 {
536 	struct dst_entry *dst = sk_dst_get(sk);
537 
538 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
539 		sk_dst_reset(sk);
540 		dst_release(dst);
541 		return NULL;
542 	}
543 
544 	return dst;
545 }
546 EXPORT_SYMBOL(sk_dst_check);
547 
548 static int sock_setbindtodevice(struct sock *sk, char __user *optval,
549 				int optlen)
550 {
551 	int ret = -ENOPROTOOPT;
552 #ifdef CONFIG_NETDEVICES
553 	struct net *net = sock_net(sk);
554 	char devname[IFNAMSIZ];
555 	int index;
556 
557 	/* Sorry... */
558 	ret = -EPERM;
559 	if (!ns_capable(net->user_ns, CAP_NET_RAW))
560 		goto out;
561 
562 	ret = -EINVAL;
563 	if (optlen < 0)
564 		goto out;
565 
566 	/* Bind this socket to a particular device like "eth0",
567 	 * as specified in the passed interface name. If the
568 	 * name is "" or the option length is zero the socket
569 	 * is not bound.
570 	 */
571 	if (optlen > IFNAMSIZ - 1)
572 		optlen = IFNAMSIZ - 1;
573 	memset(devname, 0, sizeof(devname));
574 
575 	ret = -EFAULT;
576 	if (copy_from_user(devname, optval, optlen))
577 		goto out;
578 
579 	index = 0;
580 	if (devname[0] != '\0') {
581 		struct net_device *dev;
582 
583 		rcu_read_lock();
584 		dev = dev_get_by_name_rcu(net, devname);
585 		if (dev)
586 			index = dev->ifindex;
587 		rcu_read_unlock();
588 		ret = -ENODEV;
589 		if (!dev)
590 			goto out;
591 	}
592 
593 	lock_sock(sk);
594 	sk->sk_bound_dev_if = index;
595 	sk_dst_reset(sk);
596 	release_sock(sk);
597 
598 	ret = 0;
599 
600 out:
601 #endif
602 
603 	return ret;
604 }
605 
606 static int sock_getbindtodevice(struct sock *sk, char __user *optval,
607 				int __user *optlen, int len)
608 {
609 	int ret = -ENOPROTOOPT;
610 #ifdef CONFIG_NETDEVICES
611 	struct net *net = sock_net(sk);
612 	char devname[IFNAMSIZ];
613 
614 	if (sk->sk_bound_dev_if == 0) {
615 		len = 0;
616 		goto zero;
617 	}
618 
619 	ret = -EINVAL;
620 	if (len < IFNAMSIZ)
621 		goto out;
622 
623 	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
624 	if (ret)
625 		goto out;
626 
627 	len = strlen(devname) + 1;
628 
629 	ret = -EFAULT;
630 	if (copy_to_user(optval, devname, len))
631 		goto out;
632 
633 zero:
634 	ret = -EFAULT;
635 	if (put_user(len, optlen))
636 		goto out;
637 
638 	ret = 0;
639 
640 out:
641 #endif
642 
643 	return ret;
644 }
645 
646 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
647 {
648 	if (valbool)
649 		sock_set_flag(sk, bit);
650 	else
651 		sock_reset_flag(sk, bit);
652 }
653 
654 /*
655  *	This is meant for all protocols to use and covers goings on
656  *	at the socket level. Everything here is generic.
657  */
658 
659 int sock_setsockopt(struct socket *sock, int level, int optname,
660 		    char __user *optval, unsigned int optlen)
661 {
662 	struct sock *sk = sock->sk;
663 	int val;
664 	int valbool;
665 	struct linger ling;
666 	int ret = 0;
667 
668 	/*
669 	 *	Options without arguments
670 	 */
671 
672 	if (optname == SO_BINDTODEVICE)
673 		return sock_setbindtodevice(sk, optval, optlen);
674 
675 	if (optlen < sizeof(int))
676 		return -EINVAL;
677 
678 	if (get_user(val, (int __user *)optval))
679 		return -EFAULT;
680 
681 	valbool = val ? 1 : 0;
682 
683 	lock_sock(sk);
684 
685 	switch (optname) {
686 	case SO_DEBUG:
687 		if (val && !capable(CAP_NET_ADMIN))
688 			ret = -EACCES;
689 		else
690 			sock_valbool_flag(sk, SOCK_DBG, valbool);
691 		break;
692 	case SO_REUSEADDR:
693 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
694 		break;
695 	case SO_REUSEPORT:
696 		sk->sk_reuseport = valbool;
697 		break;
698 	case SO_TYPE:
699 	case SO_PROTOCOL:
700 	case SO_DOMAIN:
701 	case SO_ERROR:
702 		ret = -ENOPROTOOPT;
703 		break;
704 	case SO_DONTROUTE:
705 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
706 		break;
707 	case SO_BROADCAST:
708 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
709 		break;
710 	case SO_SNDBUF:
711 		/* Don't error on this BSD doesn't and if you think
712 		 * about it this is right. Otherwise apps have to
713 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
714 		 * are treated in BSD as hints
715 		 */
716 		val = min_t(u32, val, sysctl_wmem_max);
717 set_sndbuf:
718 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
719 		sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
720 		/* Wake up sending tasks if we upped the value. */
721 		sk->sk_write_space(sk);
722 		break;
723 
724 	case SO_SNDBUFFORCE:
725 		if (!capable(CAP_NET_ADMIN)) {
726 			ret = -EPERM;
727 			break;
728 		}
729 		goto set_sndbuf;
730 
731 	case SO_RCVBUF:
732 		/* Don't error on this BSD doesn't and if you think
733 		 * about it this is right. Otherwise apps have to
734 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
735 		 * are treated in BSD as hints
736 		 */
737 		val = min_t(u32, val, sysctl_rmem_max);
738 set_rcvbuf:
739 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
740 		/*
741 		 * We double it on the way in to account for
742 		 * "struct sk_buff" etc. overhead.   Applications
743 		 * assume that the SO_RCVBUF setting they make will
744 		 * allow that much actual data to be received on that
745 		 * socket.
746 		 *
747 		 * Applications are unaware that "struct sk_buff" and
748 		 * other overheads allocate from the receive buffer
749 		 * during socket buffer allocation.
750 		 *
751 		 * And after considering the possible alternatives,
752 		 * returning the value we actually used in getsockopt
753 		 * is the most desirable behavior.
754 		 */
755 		sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
756 		break;
757 
758 	case SO_RCVBUFFORCE:
759 		if (!capable(CAP_NET_ADMIN)) {
760 			ret = -EPERM;
761 			break;
762 		}
763 		goto set_rcvbuf;
764 
765 	case SO_KEEPALIVE:
766 #ifdef CONFIG_INET
767 		if (sk->sk_protocol == IPPROTO_TCP &&
768 		    sk->sk_type == SOCK_STREAM)
769 			tcp_set_keepalive(sk, valbool);
770 #endif
771 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
772 		break;
773 
774 	case SO_OOBINLINE:
775 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
776 		break;
777 
778 	case SO_NO_CHECK:
779 		sk->sk_no_check_tx = valbool;
780 		break;
781 
782 	case SO_PRIORITY:
783 		if ((val >= 0 && val <= 6) ||
784 		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
785 			sk->sk_priority = val;
786 		else
787 			ret = -EPERM;
788 		break;
789 
790 	case SO_LINGER:
791 		if (optlen < sizeof(ling)) {
792 			ret = -EINVAL;	/* 1003.1g */
793 			break;
794 		}
795 		if (copy_from_user(&ling, optval, sizeof(ling))) {
796 			ret = -EFAULT;
797 			break;
798 		}
799 		if (!ling.l_onoff)
800 			sock_reset_flag(sk, SOCK_LINGER);
801 		else {
802 #if (BITS_PER_LONG == 32)
803 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
804 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
805 			else
806 #endif
807 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
808 			sock_set_flag(sk, SOCK_LINGER);
809 		}
810 		break;
811 
812 	case SO_BSDCOMPAT:
813 		sock_warn_obsolete_bsdism("setsockopt");
814 		break;
815 
816 	case SO_PASSCRED:
817 		if (valbool)
818 			set_bit(SOCK_PASSCRED, &sock->flags);
819 		else
820 			clear_bit(SOCK_PASSCRED, &sock->flags);
821 		break;
822 
823 	case SO_TIMESTAMP:
824 	case SO_TIMESTAMPNS:
825 		if (valbool)  {
826 			if (optname == SO_TIMESTAMP)
827 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
828 			else
829 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
830 			sock_set_flag(sk, SOCK_RCVTSTAMP);
831 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
832 		} else {
833 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
834 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
835 		}
836 		break;
837 
838 	case SO_TIMESTAMPING:
839 		if (val & ~SOF_TIMESTAMPING_MASK) {
840 			ret = -EINVAL;
841 			break;
842 		}
843 		if (val & SOF_TIMESTAMPING_OPT_ID &&
844 		    !(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)) {
845 			if (sk->sk_protocol == IPPROTO_TCP) {
846 				if (sk->sk_state != TCP_ESTABLISHED) {
847 					ret = -EINVAL;
848 					break;
849 				}
850 				sk->sk_tskey = tcp_sk(sk)->snd_una;
851 			} else {
852 				sk->sk_tskey = 0;
853 			}
854 		}
855 		sk->sk_tsflags = val;
856 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
857 			sock_enable_timestamp(sk,
858 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
859 		else
860 			sock_disable_timestamp(sk,
861 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
862 		break;
863 
864 	case SO_RCVLOWAT:
865 		if (val < 0)
866 			val = INT_MAX;
867 		sk->sk_rcvlowat = val ? : 1;
868 		break;
869 
870 	case SO_RCVTIMEO:
871 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
872 		break;
873 
874 	case SO_SNDTIMEO:
875 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
876 		break;
877 
878 	case SO_ATTACH_FILTER:
879 		ret = -EINVAL;
880 		if (optlen == sizeof(struct sock_fprog)) {
881 			struct sock_fprog fprog;
882 
883 			ret = -EFAULT;
884 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
885 				break;
886 
887 			ret = sk_attach_filter(&fprog, sk);
888 		}
889 		break;
890 
891 	case SO_ATTACH_BPF:
892 		ret = -EINVAL;
893 		if (optlen == sizeof(u32)) {
894 			u32 ufd;
895 
896 			ret = -EFAULT;
897 			if (copy_from_user(&ufd, optval, sizeof(ufd)))
898 				break;
899 
900 			ret = sk_attach_bpf(ufd, sk);
901 		}
902 		break;
903 
904 	case SO_DETACH_FILTER:
905 		ret = sk_detach_filter(sk);
906 		break;
907 
908 	case SO_LOCK_FILTER:
909 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
910 			ret = -EPERM;
911 		else
912 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
913 		break;
914 
915 	case SO_PASSSEC:
916 		if (valbool)
917 			set_bit(SOCK_PASSSEC, &sock->flags);
918 		else
919 			clear_bit(SOCK_PASSSEC, &sock->flags);
920 		break;
921 	case SO_MARK:
922 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
923 			ret = -EPERM;
924 		else
925 			sk->sk_mark = val;
926 		break;
927 
928 		/* We implement the SO_SNDLOWAT etc to
929 		   not be settable (1003.1g 5.3) */
930 	case SO_RXQ_OVFL:
931 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
932 		break;
933 
934 	case SO_WIFI_STATUS:
935 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
936 		break;
937 
938 	case SO_PEEK_OFF:
939 		if (sock->ops->set_peek_off)
940 			ret = sock->ops->set_peek_off(sk, val);
941 		else
942 			ret = -EOPNOTSUPP;
943 		break;
944 
945 	case SO_NOFCS:
946 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
947 		break;
948 
949 	case SO_SELECT_ERR_QUEUE:
950 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
951 		break;
952 
953 #ifdef CONFIG_NET_RX_BUSY_POLL
954 	case SO_BUSY_POLL:
955 		/* allow unprivileged users to decrease the value */
956 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
957 			ret = -EPERM;
958 		else {
959 			if (val < 0)
960 				ret = -EINVAL;
961 			else
962 				sk->sk_ll_usec = val;
963 		}
964 		break;
965 #endif
966 
967 	case SO_MAX_PACING_RATE:
968 		sk->sk_max_pacing_rate = val;
969 		sk->sk_pacing_rate = min(sk->sk_pacing_rate,
970 					 sk->sk_max_pacing_rate);
971 		break;
972 
973 	default:
974 		ret = -ENOPROTOOPT;
975 		break;
976 	}
977 	release_sock(sk);
978 	return ret;
979 }
980 EXPORT_SYMBOL(sock_setsockopt);
981 
982 
983 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
984 			  struct ucred *ucred)
985 {
986 	ucred->pid = pid_vnr(pid);
987 	ucred->uid = ucred->gid = -1;
988 	if (cred) {
989 		struct user_namespace *current_ns = current_user_ns();
990 
991 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
992 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
993 	}
994 }
995 
996 int sock_getsockopt(struct socket *sock, int level, int optname,
997 		    char __user *optval, int __user *optlen)
998 {
999 	struct sock *sk = sock->sk;
1000 
1001 	union {
1002 		int val;
1003 		struct linger ling;
1004 		struct timeval tm;
1005 	} v;
1006 
1007 	int lv = sizeof(int);
1008 	int len;
1009 
1010 	if (get_user(len, optlen))
1011 		return -EFAULT;
1012 	if (len < 0)
1013 		return -EINVAL;
1014 
1015 	memset(&v, 0, sizeof(v));
1016 
1017 	switch (optname) {
1018 	case SO_DEBUG:
1019 		v.val = sock_flag(sk, SOCK_DBG);
1020 		break;
1021 
1022 	case SO_DONTROUTE:
1023 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1024 		break;
1025 
1026 	case SO_BROADCAST:
1027 		v.val = sock_flag(sk, SOCK_BROADCAST);
1028 		break;
1029 
1030 	case SO_SNDBUF:
1031 		v.val = sk->sk_sndbuf;
1032 		break;
1033 
1034 	case SO_RCVBUF:
1035 		v.val = sk->sk_rcvbuf;
1036 		break;
1037 
1038 	case SO_REUSEADDR:
1039 		v.val = sk->sk_reuse;
1040 		break;
1041 
1042 	case SO_REUSEPORT:
1043 		v.val = sk->sk_reuseport;
1044 		break;
1045 
1046 	case SO_KEEPALIVE:
1047 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1048 		break;
1049 
1050 	case SO_TYPE:
1051 		v.val = sk->sk_type;
1052 		break;
1053 
1054 	case SO_PROTOCOL:
1055 		v.val = sk->sk_protocol;
1056 		break;
1057 
1058 	case SO_DOMAIN:
1059 		v.val = sk->sk_family;
1060 		break;
1061 
1062 	case SO_ERROR:
1063 		v.val = -sock_error(sk);
1064 		if (v.val == 0)
1065 			v.val = xchg(&sk->sk_err_soft, 0);
1066 		break;
1067 
1068 	case SO_OOBINLINE:
1069 		v.val = sock_flag(sk, SOCK_URGINLINE);
1070 		break;
1071 
1072 	case SO_NO_CHECK:
1073 		v.val = sk->sk_no_check_tx;
1074 		break;
1075 
1076 	case SO_PRIORITY:
1077 		v.val = sk->sk_priority;
1078 		break;
1079 
1080 	case SO_LINGER:
1081 		lv		= sizeof(v.ling);
1082 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1083 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1084 		break;
1085 
1086 	case SO_BSDCOMPAT:
1087 		sock_warn_obsolete_bsdism("getsockopt");
1088 		break;
1089 
1090 	case SO_TIMESTAMP:
1091 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1092 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1093 		break;
1094 
1095 	case SO_TIMESTAMPNS:
1096 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1097 		break;
1098 
1099 	case SO_TIMESTAMPING:
1100 		v.val = sk->sk_tsflags;
1101 		break;
1102 
1103 	case SO_RCVTIMEO:
1104 		lv = sizeof(struct timeval);
1105 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1106 			v.tm.tv_sec = 0;
1107 			v.tm.tv_usec = 0;
1108 		} else {
1109 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1110 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1111 		}
1112 		break;
1113 
1114 	case SO_SNDTIMEO:
1115 		lv = sizeof(struct timeval);
1116 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1117 			v.tm.tv_sec = 0;
1118 			v.tm.tv_usec = 0;
1119 		} else {
1120 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1121 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1122 		}
1123 		break;
1124 
1125 	case SO_RCVLOWAT:
1126 		v.val = sk->sk_rcvlowat;
1127 		break;
1128 
1129 	case SO_SNDLOWAT:
1130 		v.val = 1;
1131 		break;
1132 
1133 	case SO_PASSCRED:
1134 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1135 		break;
1136 
1137 	case SO_PEERCRED:
1138 	{
1139 		struct ucred peercred;
1140 		if (len > sizeof(peercred))
1141 			len = sizeof(peercred);
1142 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1143 		if (copy_to_user(optval, &peercred, len))
1144 			return -EFAULT;
1145 		goto lenout;
1146 	}
1147 
1148 	case SO_PEERNAME:
1149 	{
1150 		char address[128];
1151 
1152 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1153 			return -ENOTCONN;
1154 		if (lv < len)
1155 			return -EINVAL;
1156 		if (copy_to_user(optval, address, len))
1157 			return -EFAULT;
1158 		goto lenout;
1159 	}
1160 
1161 	/* Dubious BSD thing... Probably nobody even uses it, but
1162 	 * the UNIX standard wants it for whatever reason... -DaveM
1163 	 */
1164 	case SO_ACCEPTCONN:
1165 		v.val = sk->sk_state == TCP_LISTEN;
1166 		break;
1167 
1168 	case SO_PASSSEC:
1169 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1170 		break;
1171 
1172 	case SO_PEERSEC:
1173 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1174 
1175 	case SO_MARK:
1176 		v.val = sk->sk_mark;
1177 		break;
1178 
1179 	case SO_RXQ_OVFL:
1180 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1181 		break;
1182 
1183 	case SO_WIFI_STATUS:
1184 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1185 		break;
1186 
1187 	case SO_PEEK_OFF:
1188 		if (!sock->ops->set_peek_off)
1189 			return -EOPNOTSUPP;
1190 
1191 		v.val = sk->sk_peek_off;
1192 		break;
1193 	case SO_NOFCS:
1194 		v.val = sock_flag(sk, SOCK_NOFCS);
1195 		break;
1196 
1197 	case SO_BINDTODEVICE:
1198 		return sock_getbindtodevice(sk, optval, optlen, len);
1199 
1200 	case SO_GET_FILTER:
1201 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1202 		if (len < 0)
1203 			return len;
1204 
1205 		goto lenout;
1206 
1207 	case SO_LOCK_FILTER:
1208 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1209 		break;
1210 
1211 	case SO_BPF_EXTENSIONS:
1212 		v.val = bpf_tell_extensions();
1213 		break;
1214 
1215 	case SO_SELECT_ERR_QUEUE:
1216 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1217 		break;
1218 
1219 #ifdef CONFIG_NET_RX_BUSY_POLL
1220 	case SO_BUSY_POLL:
1221 		v.val = sk->sk_ll_usec;
1222 		break;
1223 #endif
1224 
1225 	case SO_MAX_PACING_RATE:
1226 		v.val = sk->sk_max_pacing_rate;
1227 		break;
1228 
1229 	case SO_INCOMING_CPU:
1230 		v.val = sk->sk_incoming_cpu;
1231 		break;
1232 
1233 	default:
1234 		return -ENOPROTOOPT;
1235 	}
1236 
1237 	if (len > lv)
1238 		len = lv;
1239 	if (copy_to_user(optval, &v, len))
1240 		return -EFAULT;
1241 lenout:
1242 	if (put_user(len, optlen))
1243 		return -EFAULT;
1244 	return 0;
1245 }
1246 
1247 /*
1248  * Initialize an sk_lock.
1249  *
1250  * (We also register the sk_lock with the lock validator.)
1251  */
1252 static inline void sock_lock_init(struct sock *sk)
1253 {
1254 	sock_lock_init_class_and_name(sk,
1255 			af_family_slock_key_strings[sk->sk_family],
1256 			af_family_slock_keys + sk->sk_family,
1257 			af_family_key_strings[sk->sk_family],
1258 			af_family_keys + sk->sk_family);
1259 }
1260 
1261 /*
1262  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1263  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1264  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1265  */
1266 static void sock_copy(struct sock *nsk, const struct sock *osk)
1267 {
1268 #ifdef CONFIG_SECURITY_NETWORK
1269 	void *sptr = nsk->sk_security;
1270 #endif
1271 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1272 
1273 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1274 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1275 
1276 #ifdef CONFIG_SECURITY_NETWORK
1277 	nsk->sk_security = sptr;
1278 	security_sk_clone(osk, nsk);
1279 #endif
1280 }
1281 
1282 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1283 {
1284 	unsigned long nulls1, nulls2;
1285 
1286 	nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1287 	nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1288 	if (nulls1 > nulls2)
1289 		swap(nulls1, nulls2);
1290 
1291 	if (nulls1 != 0)
1292 		memset((char *)sk, 0, nulls1);
1293 	memset((char *)sk + nulls1 + sizeof(void *), 0,
1294 	       nulls2 - nulls1 - sizeof(void *));
1295 	memset((char *)sk + nulls2 + sizeof(void *), 0,
1296 	       size - nulls2 - sizeof(void *));
1297 }
1298 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1299 
1300 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1301 		int family)
1302 {
1303 	struct sock *sk;
1304 	struct kmem_cache *slab;
1305 
1306 	slab = prot->slab;
1307 	if (slab != NULL) {
1308 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1309 		if (!sk)
1310 			return sk;
1311 		if (priority & __GFP_ZERO) {
1312 			if (prot->clear_sk)
1313 				prot->clear_sk(sk, prot->obj_size);
1314 			else
1315 				sk_prot_clear_nulls(sk, prot->obj_size);
1316 		}
1317 	} else
1318 		sk = kmalloc(prot->obj_size, priority);
1319 
1320 	if (sk != NULL) {
1321 		kmemcheck_annotate_bitfield(sk, flags);
1322 
1323 		if (security_sk_alloc(sk, family, priority))
1324 			goto out_free;
1325 
1326 		if (!try_module_get(prot->owner))
1327 			goto out_free_sec;
1328 		sk_tx_queue_clear(sk);
1329 	}
1330 
1331 	return sk;
1332 
1333 out_free_sec:
1334 	security_sk_free(sk);
1335 out_free:
1336 	if (slab != NULL)
1337 		kmem_cache_free(slab, sk);
1338 	else
1339 		kfree(sk);
1340 	return NULL;
1341 }
1342 
1343 static void sk_prot_free(struct proto *prot, struct sock *sk)
1344 {
1345 	struct kmem_cache *slab;
1346 	struct module *owner;
1347 
1348 	owner = prot->owner;
1349 	slab = prot->slab;
1350 
1351 	security_sk_free(sk);
1352 	if (slab != NULL)
1353 		kmem_cache_free(slab, sk);
1354 	else
1355 		kfree(sk);
1356 	module_put(owner);
1357 }
1358 
1359 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
1360 void sock_update_netprioidx(struct sock *sk)
1361 {
1362 	if (in_interrupt())
1363 		return;
1364 
1365 	sk->sk_cgrp_prioidx = task_netprioidx(current);
1366 }
1367 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1368 #endif
1369 
1370 /**
1371  *	sk_alloc - All socket objects are allocated here
1372  *	@net: the applicable net namespace
1373  *	@family: protocol family
1374  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1375  *	@prot: struct proto associated with this new sock instance
1376  */
1377 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1378 		      struct proto *prot)
1379 {
1380 	struct sock *sk;
1381 
1382 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1383 	if (sk) {
1384 		sk->sk_family = family;
1385 		/*
1386 		 * See comment in struct sock definition to understand
1387 		 * why we need sk_prot_creator -acme
1388 		 */
1389 		sk->sk_prot = sk->sk_prot_creator = prot;
1390 		sock_lock_init(sk);
1391 		sock_net_set(sk, get_net(net));
1392 		atomic_set(&sk->sk_wmem_alloc, 1);
1393 
1394 		sock_update_classid(sk);
1395 		sock_update_netprioidx(sk);
1396 	}
1397 
1398 	return sk;
1399 }
1400 EXPORT_SYMBOL(sk_alloc);
1401 
1402 static void __sk_free(struct sock *sk)
1403 {
1404 	struct sk_filter *filter;
1405 
1406 	if (sk->sk_destruct)
1407 		sk->sk_destruct(sk);
1408 
1409 	filter = rcu_dereference_check(sk->sk_filter,
1410 				       atomic_read(&sk->sk_wmem_alloc) == 0);
1411 	if (filter) {
1412 		sk_filter_uncharge(sk, filter);
1413 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1414 	}
1415 
1416 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1417 
1418 	if (atomic_read(&sk->sk_omem_alloc))
1419 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1420 			 __func__, atomic_read(&sk->sk_omem_alloc));
1421 
1422 	if (sk->sk_peer_cred)
1423 		put_cred(sk->sk_peer_cred);
1424 	put_pid(sk->sk_peer_pid);
1425 	put_net(sock_net(sk));
1426 	sk_prot_free(sk->sk_prot_creator, sk);
1427 }
1428 
1429 void sk_free(struct sock *sk)
1430 {
1431 	/*
1432 	 * We subtract one from sk_wmem_alloc and can know if
1433 	 * some packets are still in some tx queue.
1434 	 * If not null, sock_wfree() will call __sk_free(sk) later
1435 	 */
1436 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1437 		__sk_free(sk);
1438 }
1439 EXPORT_SYMBOL(sk_free);
1440 
1441 /*
1442  * Last sock_put should drop reference to sk->sk_net. It has already
1443  * been dropped in sk_change_net. Taking reference to stopping namespace
1444  * is not an option.
1445  * Take reference to a socket to remove it from hash _alive_ and after that
1446  * destroy it in the context of init_net.
1447  */
1448 void sk_release_kernel(struct sock *sk)
1449 {
1450 	if (sk == NULL || sk->sk_socket == NULL)
1451 		return;
1452 
1453 	sock_hold(sk);
1454 	sock_release(sk->sk_socket);
1455 	release_net(sock_net(sk));
1456 	sock_net_set(sk, get_net(&init_net));
1457 	sock_put(sk);
1458 }
1459 EXPORT_SYMBOL(sk_release_kernel);
1460 
1461 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1462 {
1463 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1464 		sock_update_memcg(newsk);
1465 }
1466 
1467 /**
1468  *	sk_clone_lock - clone a socket, and lock its clone
1469  *	@sk: the socket to clone
1470  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1471  *
1472  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1473  */
1474 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1475 {
1476 	struct sock *newsk;
1477 	bool is_charged = true;
1478 
1479 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1480 	if (newsk != NULL) {
1481 		struct sk_filter *filter;
1482 
1483 		sock_copy(newsk, sk);
1484 
1485 		/* SANITY */
1486 		get_net(sock_net(newsk));
1487 		sk_node_init(&newsk->sk_node);
1488 		sock_lock_init(newsk);
1489 		bh_lock_sock(newsk);
1490 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1491 		newsk->sk_backlog.len = 0;
1492 
1493 		atomic_set(&newsk->sk_rmem_alloc, 0);
1494 		/*
1495 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1496 		 */
1497 		atomic_set(&newsk->sk_wmem_alloc, 1);
1498 		atomic_set(&newsk->sk_omem_alloc, 0);
1499 		skb_queue_head_init(&newsk->sk_receive_queue);
1500 		skb_queue_head_init(&newsk->sk_write_queue);
1501 
1502 		spin_lock_init(&newsk->sk_dst_lock);
1503 		rwlock_init(&newsk->sk_callback_lock);
1504 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1505 				af_callback_keys + newsk->sk_family,
1506 				af_family_clock_key_strings[newsk->sk_family]);
1507 
1508 		newsk->sk_dst_cache	= NULL;
1509 		newsk->sk_wmem_queued	= 0;
1510 		newsk->sk_forward_alloc = 0;
1511 		newsk->sk_send_head	= NULL;
1512 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1513 
1514 		sock_reset_flag(newsk, SOCK_DONE);
1515 		skb_queue_head_init(&newsk->sk_error_queue);
1516 
1517 		filter = rcu_dereference_protected(newsk->sk_filter, 1);
1518 		if (filter != NULL)
1519 			/* though it's an empty new sock, the charging may fail
1520 			 * if sysctl_optmem_max was changed between creation of
1521 			 * original socket and cloning
1522 			 */
1523 			is_charged = sk_filter_charge(newsk, filter);
1524 
1525 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk))) {
1526 			/* It is still raw copy of parent, so invalidate
1527 			 * destructor and make plain sk_free() */
1528 			newsk->sk_destruct = NULL;
1529 			bh_unlock_sock(newsk);
1530 			sk_free(newsk);
1531 			newsk = NULL;
1532 			goto out;
1533 		}
1534 
1535 		newsk->sk_err	   = 0;
1536 		newsk->sk_priority = 0;
1537 		newsk->sk_incoming_cpu = raw_smp_processor_id();
1538 		/*
1539 		 * Before updating sk_refcnt, we must commit prior changes to memory
1540 		 * (Documentation/RCU/rculist_nulls.txt for details)
1541 		 */
1542 		smp_wmb();
1543 		atomic_set(&newsk->sk_refcnt, 2);
1544 
1545 		/*
1546 		 * Increment the counter in the same struct proto as the master
1547 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1548 		 * is the same as sk->sk_prot->socks, as this field was copied
1549 		 * with memcpy).
1550 		 *
1551 		 * This _changes_ the previous behaviour, where
1552 		 * tcp_create_openreq_child always was incrementing the
1553 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1554 		 * to be taken into account in all callers. -acme
1555 		 */
1556 		sk_refcnt_debug_inc(newsk);
1557 		sk_set_socket(newsk, NULL);
1558 		newsk->sk_wq = NULL;
1559 
1560 		sk_update_clone(sk, newsk);
1561 
1562 		if (newsk->sk_prot->sockets_allocated)
1563 			sk_sockets_allocated_inc(newsk);
1564 
1565 		if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1566 			net_enable_timestamp();
1567 	}
1568 out:
1569 	return newsk;
1570 }
1571 EXPORT_SYMBOL_GPL(sk_clone_lock);
1572 
1573 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1574 {
1575 	__sk_dst_set(sk, dst);
1576 	sk->sk_route_caps = dst->dev->features;
1577 	if (sk->sk_route_caps & NETIF_F_GSO)
1578 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1579 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1580 	if (sk_can_gso(sk)) {
1581 		if (dst->header_len) {
1582 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1583 		} else {
1584 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1585 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1586 			sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1587 		}
1588 	}
1589 }
1590 EXPORT_SYMBOL_GPL(sk_setup_caps);
1591 
1592 /*
1593  *	Simple resource managers for sockets.
1594  */
1595 
1596 
1597 /*
1598  * Write buffer destructor automatically called from kfree_skb.
1599  */
1600 void sock_wfree(struct sk_buff *skb)
1601 {
1602 	struct sock *sk = skb->sk;
1603 	unsigned int len = skb->truesize;
1604 
1605 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1606 		/*
1607 		 * Keep a reference on sk_wmem_alloc, this will be released
1608 		 * after sk_write_space() call
1609 		 */
1610 		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1611 		sk->sk_write_space(sk);
1612 		len = 1;
1613 	}
1614 	/*
1615 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1616 	 * could not do because of in-flight packets
1617 	 */
1618 	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1619 		__sk_free(sk);
1620 }
1621 EXPORT_SYMBOL(sock_wfree);
1622 
1623 void skb_orphan_partial(struct sk_buff *skb)
1624 {
1625 	/* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1626 	 * so we do not completely orphan skb, but transfert all
1627 	 * accounted bytes but one, to avoid unexpected reorders.
1628 	 */
1629 	if (skb->destructor == sock_wfree
1630 #ifdef CONFIG_INET
1631 	    || skb->destructor == tcp_wfree
1632 #endif
1633 		) {
1634 		atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1635 		skb->truesize = 1;
1636 	} else {
1637 		skb_orphan(skb);
1638 	}
1639 }
1640 EXPORT_SYMBOL(skb_orphan_partial);
1641 
1642 /*
1643  * Read buffer destructor automatically called from kfree_skb.
1644  */
1645 void sock_rfree(struct sk_buff *skb)
1646 {
1647 	struct sock *sk = skb->sk;
1648 	unsigned int len = skb->truesize;
1649 
1650 	atomic_sub(len, &sk->sk_rmem_alloc);
1651 	sk_mem_uncharge(sk, len);
1652 }
1653 EXPORT_SYMBOL(sock_rfree);
1654 
1655 void sock_efree(struct sk_buff *skb)
1656 {
1657 	sock_put(skb->sk);
1658 }
1659 EXPORT_SYMBOL(sock_efree);
1660 
1661 #ifdef CONFIG_INET
1662 void sock_edemux(struct sk_buff *skb)
1663 {
1664 	struct sock *sk = skb->sk;
1665 
1666 	if (sk->sk_state == TCP_TIME_WAIT)
1667 		inet_twsk_put(inet_twsk(sk));
1668 	else
1669 		sock_put(sk);
1670 }
1671 EXPORT_SYMBOL(sock_edemux);
1672 #endif
1673 
1674 kuid_t sock_i_uid(struct sock *sk)
1675 {
1676 	kuid_t uid;
1677 
1678 	read_lock_bh(&sk->sk_callback_lock);
1679 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1680 	read_unlock_bh(&sk->sk_callback_lock);
1681 	return uid;
1682 }
1683 EXPORT_SYMBOL(sock_i_uid);
1684 
1685 unsigned long sock_i_ino(struct sock *sk)
1686 {
1687 	unsigned long ino;
1688 
1689 	read_lock_bh(&sk->sk_callback_lock);
1690 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1691 	read_unlock_bh(&sk->sk_callback_lock);
1692 	return ino;
1693 }
1694 EXPORT_SYMBOL(sock_i_ino);
1695 
1696 /*
1697  * Allocate a skb from the socket's send buffer.
1698  */
1699 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1700 			     gfp_t priority)
1701 {
1702 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1703 		struct sk_buff *skb = alloc_skb(size, priority);
1704 		if (skb) {
1705 			skb_set_owner_w(skb, sk);
1706 			return skb;
1707 		}
1708 	}
1709 	return NULL;
1710 }
1711 EXPORT_SYMBOL(sock_wmalloc);
1712 
1713 /*
1714  * Allocate a memory block from the socket's option memory buffer.
1715  */
1716 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1717 {
1718 	if ((unsigned int)size <= sysctl_optmem_max &&
1719 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1720 		void *mem;
1721 		/* First do the add, to avoid the race if kmalloc
1722 		 * might sleep.
1723 		 */
1724 		atomic_add(size, &sk->sk_omem_alloc);
1725 		mem = kmalloc(size, priority);
1726 		if (mem)
1727 			return mem;
1728 		atomic_sub(size, &sk->sk_omem_alloc);
1729 	}
1730 	return NULL;
1731 }
1732 EXPORT_SYMBOL(sock_kmalloc);
1733 
1734 /*
1735  * Free an option memory block.
1736  */
1737 void sock_kfree_s(struct sock *sk, void *mem, int size)
1738 {
1739 	if (WARN_ON_ONCE(!mem))
1740 		return;
1741 	kfree(mem);
1742 	atomic_sub(size, &sk->sk_omem_alloc);
1743 }
1744 EXPORT_SYMBOL(sock_kfree_s);
1745 
1746 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1747    I think, these locks should be removed for datagram sockets.
1748  */
1749 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1750 {
1751 	DEFINE_WAIT(wait);
1752 
1753 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1754 	for (;;) {
1755 		if (!timeo)
1756 			break;
1757 		if (signal_pending(current))
1758 			break;
1759 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1760 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1761 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1762 			break;
1763 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1764 			break;
1765 		if (sk->sk_err)
1766 			break;
1767 		timeo = schedule_timeout(timeo);
1768 	}
1769 	finish_wait(sk_sleep(sk), &wait);
1770 	return timeo;
1771 }
1772 
1773 
1774 /*
1775  *	Generic send/receive buffer handlers
1776  */
1777 
1778 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1779 				     unsigned long data_len, int noblock,
1780 				     int *errcode, int max_page_order)
1781 {
1782 	struct sk_buff *skb;
1783 	long timeo;
1784 	int err;
1785 
1786 	timeo = sock_sndtimeo(sk, noblock);
1787 	for (;;) {
1788 		err = sock_error(sk);
1789 		if (err != 0)
1790 			goto failure;
1791 
1792 		err = -EPIPE;
1793 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1794 			goto failure;
1795 
1796 		if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
1797 			break;
1798 
1799 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1800 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1801 		err = -EAGAIN;
1802 		if (!timeo)
1803 			goto failure;
1804 		if (signal_pending(current))
1805 			goto interrupted;
1806 		timeo = sock_wait_for_wmem(sk, timeo);
1807 	}
1808 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
1809 				   errcode, sk->sk_allocation);
1810 	if (skb)
1811 		skb_set_owner_w(skb, sk);
1812 	return skb;
1813 
1814 interrupted:
1815 	err = sock_intr_errno(timeo);
1816 failure:
1817 	*errcode = err;
1818 	return NULL;
1819 }
1820 EXPORT_SYMBOL(sock_alloc_send_pskb);
1821 
1822 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1823 				    int noblock, int *errcode)
1824 {
1825 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1826 }
1827 EXPORT_SYMBOL(sock_alloc_send_skb);
1828 
1829 /* On 32bit arches, an skb frag is limited to 2^15 */
1830 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
1831 
1832 /**
1833  * skb_page_frag_refill - check that a page_frag contains enough room
1834  * @sz: minimum size of the fragment we want to get
1835  * @pfrag: pointer to page_frag
1836  * @gfp: priority for memory allocation
1837  *
1838  * Note: While this allocator tries to use high order pages, there is
1839  * no guarantee that allocations succeed. Therefore, @sz MUST be
1840  * less or equal than PAGE_SIZE.
1841  */
1842 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
1843 {
1844 	if (pfrag->page) {
1845 		if (atomic_read(&pfrag->page->_count) == 1) {
1846 			pfrag->offset = 0;
1847 			return true;
1848 		}
1849 		if (pfrag->offset + sz <= pfrag->size)
1850 			return true;
1851 		put_page(pfrag->page);
1852 	}
1853 
1854 	pfrag->offset = 0;
1855 	if (SKB_FRAG_PAGE_ORDER) {
1856 		pfrag->page = alloc_pages(gfp | __GFP_COMP |
1857 					  __GFP_NOWARN | __GFP_NORETRY,
1858 					  SKB_FRAG_PAGE_ORDER);
1859 		if (likely(pfrag->page)) {
1860 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
1861 			return true;
1862 		}
1863 	}
1864 	pfrag->page = alloc_page(gfp);
1865 	if (likely(pfrag->page)) {
1866 		pfrag->size = PAGE_SIZE;
1867 		return true;
1868 	}
1869 	return false;
1870 }
1871 EXPORT_SYMBOL(skb_page_frag_refill);
1872 
1873 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1874 {
1875 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1876 		return true;
1877 
1878 	sk_enter_memory_pressure(sk);
1879 	sk_stream_moderate_sndbuf(sk);
1880 	return false;
1881 }
1882 EXPORT_SYMBOL(sk_page_frag_refill);
1883 
1884 static void __lock_sock(struct sock *sk)
1885 	__releases(&sk->sk_lock.slock)
1886 	__acquires(&sk->sk_lock.slock)
1887 {
1888 	DEFINE_WAIT(wait);
1889 
1890 	for (;;) {
1891 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1892 					TASK_UNINTERRUPTIBLE);
1893 		spin_unlock_bh(&sk->sk_lock.slock);
1894 		schedule();
1895 		spin_lock_bh(&sk->sk_lock.slock);
1896 		if (!sock_owned_by_user(sk))
1897 			break;
1898 	}
1899 	finish_wait(&sk->sk_lock.wq, &wait);
1900 }
1901 
1902 static void __release_sock(struct sock *sk)
1903 	__releases(&sk->sk_lock.slock)
1904 	__acquires(&sk->sk_lock.slock)
1905 {
1906 	struct sk_buff *skb = sk->sk_backlog.head;
1907 
1908 	do {
1909 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1910 		bh_unlock_sock(sk);
1911 
1912 		do {
1913 			struct sk_buff *next = skb->next;
1914 
1915 			prefetch(next);
1916 			WARN_ON_ONCE(skb_dst_is_noref(skb));
1917 			skb->next = NULL;
1918 			sk_backlog_rcv(sk, skb);
1919 
1920 			/*
1921 			 * We are in process context here with softirqs
1922 			 * disabled, use cond_resched_softirq() to preempt.
1923 			 * This is safe to do because we've taken the backlog
1924 			 * queue private:
1925 			 */
1926 			cond_resched_softirq();
1927 
1928 			skb = next;
1929 		} while (skb != NULL);
1930 
1931 		bh_lock_sock(sk);
1932 	} while ((skb = sk->sk_backlog.head) != NULL);
1933 
1934 	/*
1935 	 * Doing the zeroing here guarantee we can not loop forever
1936 	 * while a wild producer attempts to flood us.
1937 	 */
1938 	sk->sk_backlog.len = 0;
1939 }
1940 
1941 /**
1942  * sk_wait_data - wait for data to arrive at sk_receive_queue
1943  * @sk:    sock to wait on
1944  * @timeo: for how long
1945  *
1946  * Now socket state including sk->sk_err is changed only under lock,
1947  * hence we may omit checks after joining wait queue.
1948  * We check receive queue before schedule() only as optimization;
1949  * it is very likely that release_sock() added new data.
1950  */
1951 int sk_wait_data(struct sock *sk, long *timeo)
1952 {
1953 	int rc;
1954 	DEFINE_WAIT(wait);
1955 
1956 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1957 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1958 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1959 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1960 	finish_wait(sk_sleep(sk), &wait);
1961 	return rc;
1962 }
1963 EXPORT_SYMBOL(sk_wait_data);
1964 
1965 /**
1966  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1967  *	@sk: socket
1968  *	@size: memory size to allocate
1969  *	@kind: allocation type
1970  *
1971  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1972  *	rmem allocation. This function assumes that protocols which have
1973  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1974  */
1975 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1976 {
1977 	struct proto *prot = sk->sk_prot;
1978 	int amt = sk_mem_pages(size);
1979 	long allocated;
1980 	int parent_status = UNDER_LIMIT;
1981 
1982 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1983 
1984 	allocated = sk_memory_allocated_add(sk, amt, &parent_status);
1985 
1986 	/* Under limit. */
1987 	if (parent_status == UNDER_LIMIT &&
1988 			allocated <= sk_prot_mem_limits(sk, 0)) {
1989 		sk_leave_memory_pressure(sk);
1990 		return 1;
1991 	}
1992 
1993 	/* Under pressure. (we or our parents) */
1994 	if ((parent_status > SOFT_LIMIT) ||
1995 			allocated > sk_prot_mem_limits(sk, 1))
1996 		sk_enter_memory_pressure(sk);
1997 
1998 	/* Over hard limit (we or our parents) */
1999 	if ((parent_status == OVER_LIMIT) ||
2000 			(allocated > sk_prot_mem_limits(sk, 2)))
2001 		goto suppress_allocation;
2002 
2003 	/* guarantee minimum buffer size under pressure */
2004 	if (kind == SK_MEM_RECV) {
2005 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
2006 			return 1;
2007 
2008 	} else { /* SK_MEM_SEND */
2009 		if (sk->sk_type == SOCK_STREAM) {
2010 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
2011 				return 1;
2012 		} else if (atomic_read(&sk->sk_wmem_alloc) <
2013 			   prot->sysctl_wmem[0])
2014 				return 1;
2015 	}
2016 
2017 	if (sk_has_memory_pressure(sk)) {
2018 		int alloc;
2019 
2020 		if (!sk_under_memory_pressure(sk))
2021 			return 1;
2022 		alloc = sk_sockets_allocated_read_positive(sk);
2023 		if (sk_prot_mem_limits(sk, 2) > alloc *
2024 		    sk_mem_pages(sk->sk_wmem_queued +
2025 				 atomic_read(&sk->sk_rmem_alloc) +
2026 				 sk->sk_forward_alloc))
2027 			return 1;
2028 	}
2029 
2030 suppress_allocation:
2031 
2032 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2033 		sk_stream_moderate_sndbuf(sk);
2034 
2035 		/* Fail only if socket is _under_ its sndbuf.
2036 		 * In this case we cannot block, so that we have to fail.
2037 		 */
2038 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2039 			return 1;
2040 	}
2041 
2042 	trace_sock_exceed_buf_limit(sk, prot, allocated);
2043 
2044 	/* Alas. Undo changes. */
2045 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2046 
2047 	sk_memory_allocated_sub(sk, amt);
2048 
2049 	return 0;
2050 }
2051 EXPORT_SYMBOL(__sk_mem_schedule);
2052 
2053 /**
2054  *	__sk_reclaim - reclaim memory_allocated
2055  *	@sk: socket
2056  */
2057 void __sk_mem_reclaim(struct sock *sk)
2058 {
2059 	sk_memory_allocated_sub(sk,
2060 				sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
2061 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
2062 
2063 	if (sk_under_memory_pressure(sk) &&
2064 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2065 		sk_leave_memory_pressure(sk);
2066 }
2067 EXPORT_SYMBOL(__sk_mem_reclaim);
2068 
2069 
2070 /*
2071  * Set of default routines for initialising struct proto_ops when
2072  * the protocol does not support a particular function. In certain
2073  * cases where it makes no sense for a protocol to have a "do nothing"
2074  * function, some default processing is provided.
2075  */
2076 
2077 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2078 {
2079 	return -EOPNOTSUPP;
2080 }
2081 EXPORT_SYMBOL(sock_no_bind);
2082 
2083 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2084 		    int len, int flags)
2085 {
2086 	return -EOPNOTSUPP;
2087 }
2088 EXPORT_SYMBOL(sock_no_connect);
2089 
2090 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2091 {
2092 	return -EOPNOTSUPP;
2093 }
2094 EXPORT_SYMBOL(sock_no_socketpair);
2095 
2096 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2097 {
2098 	return -EOPNOTSUPP;
2099 }
2100 EXPORT_SYMBOL(sock_no_accept);
2101 
2102 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2103 		    int *len, int peer)
2104 {
2105 	return -EOPNOTSUPP;
2106 }
2107 EXPORT_SYMBOL(sock_no_getname);
2108 
2109 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2110 {
2111 	return 0;
2112 }
2113 EXPORT_SYMBOL(sock_no_poll);
2114 
2115 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2116 {
2117 	return -EOPNOTSUPP;
2118 }
2119 EXPORT_SYMBOL(sock_no_ioctl);
2120 
2121 int sock_no_listen(struct socket *sock, int backlog)
2122 {
2123 	return -EOPNOTSUPP;
2124 }
2125 EXPORT_SYMBOL(sock_no_listen);
2126 
2127 int sock_no_shutdown(struct socket *sock, int how)
2128 {
2129 	return -EOPNOTSUPP;
2130 }
2131 EXPORT_SYMBOL(sock_no_shutdown);
2132 
2133 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2134 		    char __user *optval, unsigned int optlen)
2135 {
2136 	return -EOPNOTSUPP;
2137 }
2138 EXPORT_SYMBOL(sock_no_setsockopt);
2139 
2140 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2141 		    char __user *optval, int __user *optlen)
2142 {
2143 	return -EOPNOTSUPP;
2144 }
2145 EXPORT_SYMBOL(sock_no_getsockopt);
2146 
2147 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2148 		    size_t len)
2149 {
2150 	return -EOPNOTSUPP;
2151 }
2152 EXPORT_SYMBOL(sock_no_sendmsg);
2153 
2154 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2155 		    size_t len, int flags)
2156 {
2157 	return -EOPNOTSUPP;
2158 }
2159 EXPORT_SYMBOL(sock_no_recvmsg);
2160 
2161 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2162 {
2163 	/* Mirror missing mmap method error code */
2164 	return -ENODEV;
2165 }
2166 EXPORT_SYMBOL(sock_no_mmap);
2167 
2168 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2169 {
2170 	ssize_t res;
2171 	struct msghdr msg = {.msg_flags = flags};
2172 	struct kvec iov;
2173 	char *kaddr = kmap(page);
2174 	iov.iov_base = kaddr + offset;
2175 	iov.iov_len = size;
2176 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2177 	kunmap(page);
2178 	return res;
2179 }
2180 EXPORT_SYMBOL(sock_no_sendpage);
2181 
2182 /*
2183  *	Default Socket Callbacks
2184  */
2185 
2186 static void sock_def_wakeup(struct sock *sk)
2187 {
2188 	struct socket_wq *wq;
2189 
2190 	rcu_read_lock();
2191 	wq = rcu_dereference(sk->sk_wq);
2192 	if (wq_has_sleeper(wq))
2193 		wake_up_interruptible_all(&wq->wait);
2194 	rcu_read_unlock();
2195 }
2196 
2197 static void sock_def_error_report(struct sock *sk)
2198 {
2199 	struct socket_wq *wq;
2200 
2201 	rcu_read_lock();
2202 	wq = rcu_dereference(sk->sk_wq);
2203 	if (wq_has_sleeper(wq))
2204 		wake_up_interruptible_poll(&wq->wait, POLLERR);
2205 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2206 	rcu_read_unlock();
2207 }
2208 
2209 static void sock_def_readable(struct sock *sk)
2210 {
2211 	struct socket_wq *wq;
2212 
2213 	rcu_read_lock();
2214 	wq = rcu_dereference(sk->sk_wq);
2215 	if (wq_has_sleeper(wq))
2216 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2217 						POLLRDNORM | POLLRDBAND);
2218 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2219 	rcu_read_unlock();
2220 }
2221 
2222 static void sock_def_write_space(struct sock *sk)
2223 {
2224 	struct socket_wq *wq;
2225 
2226 	rcu_read_lock();
2227 
2228 	/* Do not wake up a writer until he can make "significant"
2229 	 * progress.  --DaveM
2230 	 */
2231 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2232 		wq = rcu_dereference(sk->sk_wq);
2233 		if (wq_has_sleeper(wq))
2234 			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2235 						POLLWRNORM | POLLWRBAND);
2236 
2237 		/* Should agree with poll, otherwise some programs break */
2238 		if (sock_writeable(sk))
2239 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2240 	}
2241 
2242 	rcu_read_unlock();
2243 }
2244 
2245 static void sock_def_destruct(struct sock *sk)
2246 {
2247 	kfree(sk->sk_protinfo);
2248 }
2249 
2250 void sk_send_sigurg(struct sock *sk)
2251 {
2252 	if (sk->sk_socket && sk->sk_socket->file)
2253 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2254 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2255 }
2256 EXPORT_SYMBOL(sk_send_sigurg);
2257 
2258 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2259 		    unsigned long expires)
2260 {
2261 	if (!mod_timer(timer, expires))
2262 		sock_hold(sk);
2263 }
2264 EXPORT_SYMBOL(sk_reset_timer);
2265 
2266 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2267 {
2268 	if (del_timer(timer))
2269 		__sock_put(sk);
2270 }
2271 EXPORT_SYMBOL(sk_stop_timer);
2272 
2273 void sock_init_data(struct socket *sock, struct sock *sk)
2274 {
2275 	skb_queue_head_init(&sk->sk_receive_queue);
2276 	skb_queue_head_init(&sk->sk_write_queue);
2277 	skb_queue_head_init(&sk->sk_error_queue);
2278 
2279 	sk->sk_send_head	=	NULL;
2280 
2281 	init_timer(&sk->sk_timer);
2282 
2283 	sk->sk_allocation	=	GFP_KERNEL;
2284 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2285 	sk->sk_sndbuf		=	sysctl_wmem_default;
2286 	sk->sk_state		=	TCP_CLOSE;
2287 	sk_set_socket(sk, sock);
2288 
2289 	sock_set_flag(sk, SOCK_ZAPPED);
2290 
2291 	if (sock) {
2292 		sk->sk_type	=	sock->type;
2293 		sk->sk_wq	=	sock->wq;
2294 		sock->sk	=	sk;
2295 	} else
2296 		sk->sk_wq	=	NULL;
2297 
2298 	spin_lock_init(&sk->sk_dst_lock);
2299 	rwlock_init(&sk->sk_callback_lock);
2300 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2301 			af_callback_keys + sk->sk_family,
2302 			af_family_clock_key_strings[sk->sk_family]);
2303 
2304 	sk->sk_state_change	=	sock_def_wakeup;
2305 	sk->sk_data_ready	=	sock_def_readable;
2306 	sk->sk_write_space	=	sock_def_write_space;
2307 	sk->sk_error_report	=	sock_def_error_report;
2308 	sk->sk_destruct		=	sock_def_destruct;
2309 
2310 	sk->sk_frag.page	=	NULL;
2311 	sk->sk_frag.offset	=	0;
2312 	sk->sk_peek_off		=	-1;
2313 
2314 	sk->sk_peer_pid 	=	NULL;
2315 	sk->sk_peer_cred	=	NULL;
2316 	sk->sk_write_pending	=	0;
2317 	sk->sk_rcvlowat		=	1;
2318 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2319 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2320 
2321 	sk->sk_stamp = ktime_set(-1L, 0);
2322 
2323 #ifdef CONFIG_NET_RX_BUSY_POLL
2324 	sk->sk_napi_id		=	0;
2325 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2326 #endif
2327 
2328 	sk->sk_max_pacing_rate = ~0U;
2329 	sk->sk_pacing_rate = ~0U;
2330 	/*
2331 	 * Before updating sk_refcnt, we must commit prior changes to memory
2332 	 * (Documentation/RCU/rculist_nulls.txt for details)
2333 	 */
2334 	smp_wmb();
2335 	atomic_set(&sk->sk_refcnt, 1);
2336 	atomic_set(&sk->sk_drops, 0);
2337 }
2338 EXPORT_SYMBOL(sock_init_data);
2339 
2340 void lock_sock_nested(struct sock *sk, int subclass)
2341 {
2342 	might_sleep();
2343 	spin_lock_bh(&sk->sk_lock.slock);
2344 	if (sk->sk_lock.owned)
2345 		__lock_sock(sk);
2346 	sk->sk_lock.owned = 1;
2347 	spin_unlock(&sk->sk_lock.slock);
2348 	/*
2349 	 * The sk_lock has mutex_lock() semantics here:
2350 	 */
2351 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2352 	local_bh_enable();
2353 }
2354 EXPORT_SYMBOL(lock_sock_nested);
2355 
2356 void release_sock(struct sock *sk)
2357 {
2358 	/*
2359 	 * The sk_lock has mutex_unlock() semantics:
2360 	 */
2361 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2362 
2363 	spin_lock_bh(&sk->sk_lock.slock);
2364 	if (sk->sk_backlog.tail)
2365 		__release_sock(sk);
2366 
2367 	/* Warning : release_cb() might need to release sk ownership,
2368 	 * ie call sock_release_ownership(sk) before us.
2369 	 */
2370 	if (sk->sk_prot->release_cb)
2371 		sk->sk_prot->release_cb(sk);
2372 
2373 	sock_release_ownership(sk);
2374 	if (waitqueue_active(&sk->sk_lock.wq))
2375 		wake_up(&sk->sk_lock.wq);
2376 	spin_unlock_bh(&sk->sk_lock.slock);
2377 }
2378 EXPORT_SYMBOL(release_sock);
2379 
2380 /**
2381  * lock_sock_fast - fast version of lock_sock
2382  * @sk: socket
2383  *
2384  * This version should be used for very small section, where process wont block
2385  * return false if fast path is taken
2386  *   sk_lock.slock locked, owned = 0, BH disabled
2387  * return true if slow path is taken
2388  *   sk_lock.slock unlocked, owned = 1, BH enabled
2389  */
2390 bool lock_sock_fast(struct sock *sk)
2391 {
2392 	might_sleep();
2393 	spin_lock_bh(&sk->sk_lock.slock);
2394 
2395 	if (!sk->sk_lock.owned)
2396 		/*
2397 		 * Note : We must disable BH
2398 		 */
2399 		return false;
2400 
2401 	__lock_sock(sk);
2402 	sk->sk_lock.owned = 1;
2403 	spin_unlock(&sk->sk_lock.slock);
2404 	/*
2405 	 * The sk_lock has mutex_lock() semantics here:
2406 	 */
2407 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2408 	local_bh_enable();
2409 	return true;
2410 }
2411 EXPORT_SYMBOL(lock_sock_fast);
2412 
2413 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2414 {
2415 	struct timeval tv;
2416 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2417 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2418 	tv = ktime_to_timeval(sk->sk_stamp);
2419 	if (tv.tv_sec == -1)
2420 		return -ENOENT;
2421 	if (tv.tv_sec == 0) {
2422 		sk->sk_stamp = ktime_get_real();
2423 		tv = ktime_to_timeval(sk->sk_stamp);
2424 	}
2425 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2426 }
2427 EXPORT_SYMBOL(sock_get_timestamp);
2428 
2429 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2430 {
2431 	struct timespec ts;
2432 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2433 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2434 	ts = ktime_to_timespec(sk->sk_stamp);
2435 	if (ts.tv_sec == -1)
2436 		return -ENOENT;
2437 	if (ts.tv_sec == 0) {
2438 		sk->sk_stamp = ktime_get_real();
2439 		ts = ktime_to_timespec(sk->sk_stamp);
2440 	}
2441 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2442 }
2443 EXPORT_SYMBOL(sock_get_timestampns);
2444 
2445 void sock_enable_timestamp(struct sock *sk, int flag)
2446 {
2447 	if (!sock_flag(sk, flag)) {
2448 		unsigned long previous_flags = sk->sk_flags;
2449 
2450 		sock_set_flag(sk, flag);
2451 		/*
2452 		 * we just set one of the two flags which require net
2453 		 * time stamping, but time stamping might have been on
2454 		 * already because of the other one
2455 		 */
2456 		if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2457 			net_enable_timestamp();
2458 	}
2459 }
2460 
2461 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2462 		       int level, int type)
2463 {
2464 	struct sock_exterr_skb *serr;
2465 	struct sk_buff *skb;
2466 	int copied, err;
2467 
2468 	err = -EAGAIN;
2469 	skb = sock_dequeue_err_skb(sk);
2470 	if (skb == NULL)
2471 		goto out;
2472 
2473 	copied = skb->len;
2474 	if (copied > len) {
2475 		msg->msg_flags |= MSG_TRUNC;
2476 		copied = len;
2477 	}
2478 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
2479 	if (err)
2480 		goto out_free_skb;
2481 
2482 	sock_recv_timestamp(msg, sk, skb);
2483 
2484 	serr = SKB_EXT_ERR(skb);
2485 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2486 
2487 	msg->msg_flags |= MSG_ERRQUEUE;
2488 	err = copied;
2489 
2490 out_free_skb:
2491 	kfree_skb(skb);
2492 out:
2493 	return err;
2494 }
2495 EXPORT_SYMBOL(sock_recv_errqueue);
2496 
2497 /*
2498  *	Get a socket option on an socket.
2499  *
2500  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2501  *	asynchronous errors should be reported by getsockopt. We assume
2502  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2503  */
2504 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2505 			   char __user *optval, int __user *optlen)
2506 {
2507 	struct sock *sk = sock->sk;
2508 
2509 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2510 }
2511 EXPORT_SYMBOL(sock_common_getsockopt);
2512 
2513 #ifdef CONFIG_COMPAT
2514 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2515 				  char __user *optval, int __user *optlen)
2516 {
2517 	struct sock *sk = sock->sk;
2518 
2519 	if (sk->sk_prot->compat_getsockopt != NULL)
2520 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2521 						      optval, optlen);
2522 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2523 }
2524 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2525 #endif
2526 
2527 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2528 			struct msghdr *msg, size_t size, int flags)
2529 {
2530 	struct sock *sk = sock->sk;
2531 	int addr_len = 0;
2532 	int err;
2533 
2534 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2535 				   flags & ~MSG_DONTWAIT, &addr_len);
2536 	if (err >= 0)
2537 		msg->msg_namelen = addr_len;
2538 	return err;
2539 }
2540 EXPORT_SYMBOL(sock_common_recvmsg);
2541 
2542 /*
2543  *	Set socket options on an inet socket.
2544  */
2545 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2546 			   char __user *optval, unsigned int optlen)
2547 {
2548 	struct sock *sk = sock->sk;
2549 
2550 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2551 }
2552 EXPORT_SYMBOL(sock_common_setsockopt);
2553 
2554 #ifdef CONFIG_COMPAT
2555 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2556 				  char __user *optval, unsigned int optlen)
2557 {
2558 	struct sock *sk = sock->sk;
2559 
2560 	if (sk->sk_prot->compat_setsockopt != NULL)
2561 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2562 						      optval, optlen);
2563 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2564 }
2565 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2566 #endif
2567 
2568 void sk_common_release(struct sock *sk)
2569 {
2570 	if (sk->sk_prot->destroy)
2571 		sk->sk_prot->destroy(sk);
2572 
2573 	/*
2574 	 * Observation: when sock_common_release is called, processes have
2575 	 * no access to socket. But net still has.
2576 	 * Step one, detach it from networking:
2577 	 *
2578 	 * A. Remove from hash tables.
2579 	 */
2580 
2581 	sk->sk_prot->unhash(sk);
2582 
2583 	/*
2584 	 * In this point socket cannot receive new packets, but it is possible
2585 	 * that some packets are in flight because some CPU runs receiver and
2586 	 * did hash table lookup before we unhashed socket. They will achieve
2587 	 * receive queue and will be purged by socket destructor.
2588 	 *
2589 	 * Also we still have packets pending on receive queue and probably,
2590 	 * our own packets waiting in device queues. sock_destroy will drain
2591 	 * receive queue, but transmitted packets will delay socket destruction
2592 	 * until the last reference will be released.
2593 	 */
2594 
2595 	sock_orphan(sk);
2596 
2597 	xfrm_sk_free_policy(sk);
2598 
2599 	sk_refcnt_debug_release(sk);
2600 
2601 	if (sk->sk_frag.page) {
2602 		put_page(sk->sk_frag.page);
2603 		sk->sk_frag.page = NULL;
2604 	}
2605 
2606 	sock_put(sk);
2607 }
2608 EXPORT_SYMBOL(sk_common_release);
2609 
2610 #ifdef CONFIG_PROC_FS
2611 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2612 struct prot_inuse {
2613 	int val[PROTO_INUSE_NR];
2614 };
2615 
2616 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2617 
2618 #ifdef CONFIG_NET_NS
2619 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2620 {
2621 	__this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2622 }
2623 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2624 
2625 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2626 {
2627 	int cpu, idx = prot->inuse_idx;
2628 	int res = 0;
2629 
2630 	for_each_possible_cpu(cpu)
2631 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2632 
2633 	return res >= 0 ? res : 0;
2634 }
2635 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2636 
2637 static int __net_init sock_inuse_init_net(struct net *net)
2638 {
2639 	net->core.inuse = alloc_percpu(struct prot_inuse);
2640 	return net->core.inuse ? 0 : -ENOMEM;
2641 }
2642 
2643 static void __net_exit sock_inuse_exit_net(struct net *net)
2644 {
2645 	free_percpu(net->core.inuse);
2646 }
2647 
2648 static struct pernet_operations net_inuse_ops = {
2649 	.init = sock_inuse_init_net,
2650 	.exit = sock_inuse_exit_net,
2651 };
2652 
2653 static __init int net_inuse_init(void)
2654 {
2655 	if (register_pernet_subsys(&net_inuse_ops))
2656 		panic("Cannot initialize net inuse counters");
2657 
2658 	return 0;
2659 }
2660 
2661 core_initcall(net_inuse_init);
2662 #else
2663 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2664 
2665 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2666 {
2667 	__this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2668 }
2669 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2670 
2671 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2672 {
2673 	int cpu, idx = prot->inuse_idx;
2674 	int res = 0;
2675 
2676 	for_each_possible_cpu(cpu)
2677 		res += per_cpu(prot_inuse, cpu).val[idx];
2678 
2679 	return res >= 0 ? res : 0;
2680 }
2681 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2682 #endif
2683 
2684 static void assign_proto_idx(struct proto *prot)
2685 {
2686 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2687 
2688 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2689 		pr_err("PROTO_INUSE_NR exhausted\n");
2690 		return;
2691 	}
2692 
2693 	set_bit(prot->inuse_idx, proto_inuse_idx);
2694 }
2695 
2696 static void release_proto_idx(struct proto *prot)
2697 {
2698 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2699 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2700 }
2701 #else
2702 static inline void assign_proto_idx(struct proto *prot)
2703 {
2704 }
2705 
2706 static inline void release_proto_idx(struct proto *prot)
2707 {
2708 }
2709 #endif
2710 
2711 int proto_register(struct proto *prot, int alloc_slab)
2712 {
2713 	if (alloc_slab) {
2714 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2715 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2716 					NULL);
2717 
2718 		if (prot->slab == NULL) {
2719 			pr_crit("%s: Can't create sock SLAB cache!\n",
2720 				prot->name);
2721 			goto out;
2722 		}
2723 
2724 		if (prot->rsk_prot != NULL) {
2725 			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2726 			if (prot->rsk_prot->slab_name == NULL)
2727 				goto out_free_sock_slab;
2728 
2729 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2730 								 prot->rsk_prot->obj_size, 0,
2731 								 SLAB_HWCACHE_ALIGN, NULL);
2732 
2733 			if (prot->rsk_prot->slab == NULL) {
2734 				pr_crit("%s: Can't create request sock SLAB cache!\n",
2735 					prot->name);
2736 				goto out_free_request_sock_slab_name;
2737 			}
2738 		}
2739 
2740 		if (prot->twsk_prot != NULL) {
2741 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2742 
2743 			if (prot->twsk_prot->twsk_slab_name == NULL)
2744 				goto out_free_request_sock_slab;
2745 
2746 			prot->twsk_prot->twsk_slab =
2747 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2748 						  prot->twsk_prot->twsk_obj_size,
2749 						  0,
2750 						  SLAB_HWCACHE_ALIGN |
2751 							prot->slab_flags,
2752 						  NULL);
2753 			if (prot->twsk_prot->twsk_slab == NULL)
2754 				goto out_free_timewait_sock_slab_name;
2755 		}
2756 	}
2757 
2758 	mutex_lock(&proto_list_mutex);
2759 	list_add(&prot->node, &proto_list);
2760 	assign_proto_idx(prot);
2761 	mutex_unlock(&proto_list_mutex);
2762 	return 0;
2763 
2764 out_free_timewait_sock_slab_name:
2765 	kfree(prot->twsk_prot->twsk_slab_name);
2766 out_free_request_sock_slab:
2767 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2768 		kmem_cache_destroy(prot->rsk_prot->slab);
2769 		prot->rsk_prot->slab = NULL;
2770 	}
2771 out_free_request_sock_slab_name:
2772 	if (prot->rsk_prot)
2773 		kfree(prot->rsk_prot->slab_name);
2774 out_free_sock_slab:
2775 	kmem_cache_destroy(prot->slab);
2776 	prot->slab = NULL;
2777 out:
2778 	return -ENOBUFS;
2779 }
2780 EXPORT_SYMBOL(proto_register);
2781 
2782 void proto_unregister(struct proto *prot)
2783 {
2784 	mutex_lock(&proto_list_mutex);
2785 	release_proto_idx(prot);
2786 	list_del(&prot->node);
2787 	mutex_unlock(&proto_list_mutex);
2788 
2789 	if (prot->slab != NULL) {
2790 		kmem_cache_destroy(prot->slab);
2791 		prot->slab = NULL;
2792 	}
2793 
2794 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2795 		kmem_cache_destroy(prot->rsk_prot->slab);
2796 		kfree(prot->rsk_prot->slab_name);
2797 		prot->rsk_prot->slab = NULL;
2798 	}
2799 
2800 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2801 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2802 		kfree(prot->twsk_prot->twsk_slab_name);
2803 		prot->twsk_prot->twsk_slab = NULL;
2804 	}
2805 }
2806 EXPORT_SYMBOL(proto_unregister);
2807 
2808 #ifdef CONFIG_PROC_FS
2809 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2810 	__acquires(proto_list_mutex)
2811 {
2812 	mutex_lock(&proto_list_mutex);
2813 	return seq_list_start_head(&proto_list, *pos);
2814 }
2815 
2816 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2817 {
2818 	return seq_list_next(v, &proto_list, pos);
2819 }
2820 
2821 static void proto_seq_stop(struct seq_file *seq, void *v)
2822 	__releases(proto_list_mutex)
2823 {
2824 	mutex_unlock(&proto_list_mutex);
2825 }
2826 
2827 static char proto_method_implemented(const void *method)
2828 {
2829 	return method == NULL ? 'n' : 'y';
2830 }
2831 static long sock_prot_memory_allocated(struct proto *proto)
2832 {
2833 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2834 }
2835 
2836 static char *sock_prot_memory_pressure(struct proto *proto)
2837 {
2838 	return proto->memory_pressure != NULL ?
2839 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2840 }
2841 
2842 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2843 {
2844 
2845 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2846 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2847 		   proto->name,
2848 		   proto->obj_size,
2849 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2850 		   sock_prot_memory_allocated(proto),
2851 		   sock_prot_memory_pressure(proto),
2852 		   proto->max_header,
2853 		   proto->slab == NULL ? "no" : "yes",
2854 		   module_name(proto->owner),
2855 		   proto_method_implemented(proto->close),
2856 		   proto_method_implemented(proto->connect),
2857 		   proto_method_implemented(proto->disconnect),
2858 		   proto_method_implemented(proto->accept),
2859 		   proto_method_implemented(proto->ioctl),
2860 		   proto_method_implemented(proto->init),
2861 		   proto_method_implemented(proto->destroy),
2862 		   proto_method_implemented(proto->shutdown),
2863 		   proto_method_implemented(proto->setsockopt),
2864 		   proto_method_implemented(proto->getsockopt),
2865 		   proto_method_implemented(proto->sendmsg),
2866 		   proto_method_implemented(proto->recvmsg),
2867 		   proto_method_implemented(proto->sendpage),
2868 		   proto_method_implemented(proto->bind),
2869 		   proto_method_implemented(proto->backlog_rcv),
2870 		   proto_method_implemented(proto->hash),
2871 		   proto_method_implemented(proto->unhash),
2872 		   proto_method_implemented(proto->get_port),
2873 		   proto_method_implemented(proto->enter_memory_pressure));
2874 }
2875 
2876 static int proto_seq_show(struct seq_file *seq, void *v)
2877 {
2878 	if (v == &proto_list)
2879 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2880 			   "protocol",
2881 			   "size",
2882 			   "sockets",
2883 			   "memory",
2884 			   "press",
2885 			   "maxhdr",
2886 			   "slab",
2887 			   "module",
2888 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2889 	else
2890 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2891 	return 0;
2892 }
2893 
2894 static const struct seq_operations proto_seq_ops = {
2895 	.start  = proto_seq_start,
2896 	.next   = proto_seq_next,
2897 	.stop   = proto_seq_stop,
2898 	.show   = proto_seq_show,
2899 };
2900 
2901 static int proto_seq_open(struct inode *inode, struct file *file)
2902 {
2903 	return seq_open_net(inode, file, &proto_seq_ops,
2904 			    sizeof(struct seq_net_private));
2905 }
2906 
2907 static const struct file_operations proto_seq_fops = {
2908 	.owner		= THIS_MODULE,
2909 	.open		= proto_seq_open,
2910 	.read		= seq_read,
2911 	.llseek		= seq_lseek,
2912 	.release	= seq_release_net,
2913 };
2914 
2915 static __net_init int proto_init_net(struct net *net)
2916 {
2917 	if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
2918 		return -ENOMEM;
2919 
2920 	return 0;
2921 }
2922 
2923 static __net_exit void proto_exit_net(struct net *net)
2924 {
2925 	remove_proc_entry("protocols", net->proc_net);
2926 }
2927 
2928 
2929 static __net_initdata struct pernet_operations proto_net_ops = {
2930 	.init = proto_init_net,
2931 	.exit = proto_exit_net,
2932 };
2933 
2934 static int __init proto_init(void)
2935 {
2936 	return register_pernet_subsys(&proto_net_ops);
2937 }
2938 
2939 subsys_initcall(proto_init);
2940 
2941 #endif /* PROC_FS */
2942