xref: /linux/net/core/sock.c (revision 30614cf34105c5b5b9a39c65a2ea32c58b03aa8e)
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_DETACH_FILTER:
892 		ret = sk_detach_filter(sk);
893 		break;
894 
895 	case SO_LOCK_FILTER:
896 		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
897 			ret = -EPERM;
898 		else
899 			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
900 		break;
901 
902 	case SO_PASSSEC:
903 		if (valbool)
904 			set_bit(SOCK_PASSSEC, &sock->flags);
905 		else
906 			clear_bit(SOCK_PASSSEC, &sock->flags);
907 		break;
908 	case SO_MARK:
909 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
910 			ret = -EPERM;
911 		else
912 			sk->sk_mark = val;
913 		break;
914 
915 		/* We implement the SO_SNDLOWAT etc to
916 		   not be settable (1003.1g 5.3) */
917 	case SO_RXQ_OVFL:
918 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
919 		break;
920 
921 	case SO_WIFI_STATUS:
922 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
923 		break;
924 
925 	case SO_PEEK_OFF:
926 		if (sock->ops->set_peek_off)
927 			ret = sock->ops->set_peek_off(sk, val);
928 		else
929 			ret = -EOPNOTSUPP;
930 		break;
931 
932 	case SO_NOFCS:
933 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
934 		break;
935 
936 	case SO_SELECT_ERR_QUEUE:
937 		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
938 		break;
939 
940 #ifdef CONFIG_NET_RX_BUSY_POLL
941 	case SO_BUSY_POLL:
942 		/* allow unprivileged users to decrease the value */
943 		if ((val > sk->sk_ll_usec) && !capable(CAP_NET_ADMIN))
944 			ret = -EPERM;
945 		else {
946 			if (val < 0)
947 				ret = -EINVAL;
948 			else
949 				sk->sk_ll_usec = val;
950 		}
951 		break;
952 #endif
953 
954 	case SO_MAX_PACING_RATE:
955 		sk->sk_max_pacing_rate = val;
956 		sk->sk_pacing_rate = min(sk->sk_pacing_rate,
957 					 sk->sk_max_pacing_rate);
958 		break;
959 
960 	default:
961 		ret = -ENOPROTOOPT;
962 		break;
963 	}
964 	release_sock(sk);
965 	return ret;
966 }
967 EXPORT_SYMBOL(sock_setsockopt);
968 
969 
970 static void cred_to_ucred(struct pid *pid, const struct cred *cred,
971 			  struct ucred *ucred)
972 {
973 	ucred->pid = pid_vnr(pid);
974 	ucred->uid = ucred->gid = -1;
975 	if (cred) {
976 		struct user_namespace *current_ns = current_user_ns();
977 
978 		ucred->uid = from_kuid_munged(current_ns, cred->euid);
979 		ucred->gid = from_kgid_munged(current_ns, cred->egid);
980 	}
981 }
982 
983 int sock_getsockopt(struct socket *sock, int level, int optname,
984 		    char __user *optval, int __user *optlen)
985 {
986 	struct sock *sk = sock->sk;
987 
988 	union {
989 		int val;
990 		struct linger ling;
991 		struct timeval tm;
992 	} v;
993 
994 	int lv = sizeof(int);
995 	int len;
996 
997 	if (get_user(len, optlen))
998 		return -EFAULT;
999 	if (len < 0)
1000 		return -EINVAL;
1001 
1002 	memset(&v, 0, sizeof(v));
1003 
1004 	switch (optname) {
1005 	case SO_DEBUG:
1006 		v.val = sock_flag(sk, SOCK_DBG);
1007 		break;
1008 
1009 	case SO_DONTROUTE:
1010 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
1011 		break;
1012 
1013 	case SO_BROADCAST:
1014 		v.val = sock_flag(sk, SOCK_BROADCAST);
1015 		break;
1016 
1017 	case SO_SNDBUF:
1018 		v.val = sk->sk_sndbuf;
1019 		break;
1020 
1021 	case SO_RCVBUF:
1022 		v.val = sk->sk_rcvbuf;
1023 		break;
1024 
1025 	case SO_REUSEADDR:
1026 		v.val = sk->sk_reuse;
1027 		break;
1028 
1029 	case SO_REUSEPORT:
1030 		v.val = sk->sk_reuseport;
1031 		break;
1032 
1033 	case SO_KEEPALIVE:
1034 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
1035 		break;
1036 
1037 	case SO_TYPE:
1038 		v.val = sk->sk_type;
1039 		break;
1040 
1041 	case SO_PROTOCOL:
1042 		v.val = sk->sk_protocol;
1043 		break;
1044 
1045 	case SO_DOMAIN:
1046 		v.val = sk->sk_family;
1047 		break;
1048 
1049 	case SO_ERROR:
1050 		v.val = -sock_error(sk);
1051 		if (v.val == 0)
1052 			v.val = xchg(&sk->sk_err_soft, 0);
1053 		break;
1054 
1055 	case SO_OOBINLINE:
1056 		v.val = sock_flag(sk, SOCK_URGINLINE);
1057 		break;
1058 
1059 	case SO_NO_CHECK:
1060 		v.val = sk->sk_no_check_tx;
1061 		break;
1062 
1063 	case SO_PRIORITY:
1064 		v.val = sk->sk_priority;
1065 		break;
1066 
1067 	case SO_LINGER:
1068 		lv		= sizeof(v.ling);
1069 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
1070 		v.ling.l_linger	= sk->sk_lingertime / HZ;
1071 		break;
1072 
1073 	case SO_BSDCOMPAT:
1074 		sock_warn_obsolete_bsdism("getsockopt");
1075 		break;
1076 
1077 	case SO_TIMESTAMP:
1078 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
1079 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
1080 		break;
1081 
1082 	case SO_TIMESTAMPNS:
1083 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
1084 		break;
1085 
1086 	case SO_TIMESTAMPING:
1087 		v.val = sk->sk_tsflags;
1088 		break;
1089 
1090 	case SO_RCVTIMEO:
1091 		lv = sizeof(struct timeval);
1092 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
1093 			v.tm.tv_sec = 0;
1094 			v.tm.tv_usec = 0;
1095 		} else {
1096 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1097 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1098 		}
1099 		break;
1100 
1101 	case SO_SNDTIMEO:
1102 		lv = sizeof(struct timeval);
1103 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1104 			v.tm.tv_sec = 0;
1105 			v.tm.tv_usec = 0;
1106 		} else {
1107 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1108 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1109 		}
1110 		break;
1111 
1112 	case SO_RCVLOWAT:
1113 		v.val = sk->sk_rcvlowat;
1114 		break;
1115 
1116 	case SO_SNDLOWAT:
1117 		v.val = 1;
1118 		break;
1119 
1120 	case SO_PASSCRED:
1121 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1122 		break;
1123 
1124 	case SO_PEERCRED:
1125 	{
1126 		struct ucred peercred;
1127 		if (len > sizeof(peercred))
1128 			len = sizeof(peercred);
1129 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1130 		if (copy_to_user(optval, &peercred, len))
1131 			return -EFAULT;
1132 		goto lenout;
1133 	}
1134 
1135 	case SO_PEERNAME:
1136 	{
1137 		char address[128];
1138 
1139 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1140 			return -ENOTCONN;
1141 		if (lv < len)
1142 			return -EINVAL;
1143 		if (copy_to_user(optval, address, len))
1144 			return -EFAULT;
1145 		goto lenout;
1146 	}
1147 
1148 	/* Dubious BSD thing... Probably nobody even uses it, but
1149 	 * the UNIX standard wants it for whatever reason... -DaveM
1150 	 */
1151 	case SO_ACCEPTCONN:
1152 		v.val = sk->sk_state == TCP_LISTEN;
1153 		break;
1154 
1155 	case SO_PASSSEC:
1156 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1157 		break;
1158 
1159 	case SO_PEERSEC:
1160 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1161 
1162 	case SO_MARK:
1163 		v.val = sk->sk_mark;
1164 		break;
1165 
1166 	case SO_RXQ_OVFL:
1167 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1168 		break;
1169 
1170 	case SO_WIFI_STATUS:
1171 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1172 		break;
1173 
1174 	case SO_PEEK_OFF:
1175 		if (!sock->ops->set_peek_off)
1176 			return -EOPNOTSUPP;
1177 
1178 		v.val = sk->sk_peek_off;
1179 		break;
1180 	case SO_NOFCS:
1181 		v.val = sock_flag(sk, SOCK_NOFCS);
1182 		break;
1183 
1184 	case SO_BINDTODEVICE:
1185 		return sock_getbindtodevice(sk, optval, optlen, len);
1186 
1187 	case SO_GET_FILTER:
1188 		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
1189 		if (len < 0)
1190 			return len;
1191 
1192 		goto lenout;
1193 
1194 	case SO_LOCK_FILTER:
1195 		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
1196 		break;
1197 
1198 	case SO_BPF_EXTENSIONS:
1199 		v.val = bpf_tell_extensions();
1200 		break;
1201 
1202 	case SO_SELECT_ERR_QUEUE:
1203 		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
1204 		break;
1205 
1206 #ifdef CONFIG_NET_RX_BUSY_POLL
1207 	case SO_BUSY_POLL:
1208 		v.val = sk->sk_ll_usec;
1209 		break;
1210 #endif
1211 
1212 	case SO_MAX_PACING_RATE:
1213 		v.val = sk->sk_max_pacing_rate;
1214 		break;
1215 
1216 	default:
1217 		return -ENOPROTOOPT;
1218 	}
1219 
1220 	if (len > lv)
1221 		len = lv;
1222 	if (copy_to_user(optval, &v, len))
1223 		return -EFAULT;
1224 lenout:
1225 	if (put_user(len, optlen))
1226 		return -EFAULT;
1227 	return 0;
1228 }
1229 
1230 /*
1231  * Initialize an sk_lock.
1232  *
1233  * (We also register the sk_lock with the lock validator.)
1234  */
1235 static inline void sock_lock_init(struct sock *sk)
1236 {
1237 	sock_lock_init_class_and_name(sk,
1238 			af_family_slock_key_strings[sk->sk_family],
1239 			af_family_slock_keys + sk->sk_family,
1240 			af_family_key_strings[sk->sk_family],
1241 			af_family_keys + sk->sk_family);
1242 }
1243 
1244 /*
1245  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1246  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1247  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1248  */
1249 static void sock_copy(struct sock *nsk, const struct sock *osk)
1250 {
1251 #ifdef CONFIG_SECURITY_NETWORK
1252 	void *sptr = nsk->sk_security;
1253 #endif
1254 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1255 
1256 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1257 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1258 
1259 #ifdef CONFIG_SECURITY_NETWORK
1260 	nsk->sk_security = sptr;
1261 	security_sk_clone(osk, nsk);
1262 #endif
1263 }
1264 
1265 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1266 {
1267 	unsigned long nulls1, nulls2;
1268 
1269 	nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1270 	nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1271 	if (nulls1 > nulls2)
1272 		swap(nulls1, nulls2);
1273 
1274 	if (nulls1 != 0)
1275 		memset((char *)sk, 0, nulls1);
1276 	memset((char *)sk + nulls1 + sizeof(void *), 0,
1277 	       nulls2 - nulls1 - sizeof(void *));
1278 	memset((char *)sk + nulls2 + sizeof(void *), 0,
1279 	       size - nulls2 - sizeof(void *));
1280 }
1281 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1282 
1283 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1284 		int family)
1285 {
1286 	struct sock *sk;
1287 	struct kmem_cache *slab;
1288 
1289 	slab = prot->slab;
1290 	if (slab != NULL) {
1291 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1292 		if (!sk)
1293 			return sk;
1294 		if (priority & __GFP_ZERO) {
1295 			if (prot->clear_sk)
1296 				prot->clear_sk(sk, prot->obj_size);
1297 			else
1298 				sk_prot_clear_nulls(sk, prot->obj_size);
1299 		}
1300 	} else
1301 		sk = kmalloc(prot->obj_size, priority);
1302 
1303 	if (sk != NULL) {
1304 		kmemcheck_annotate_bitfield(sk, flags);
1305 
1306 		if (security_sk_alloc(sk, family, priority))
1307 			goto out_free;
1308 
1309 		if (!try_module_get(prot->owner))
1310 			goto out_free_sec;
1311 		sk_tx_queue_clear(sk);
1312 	}
1313 
1314 	return sk;
1315 
1316 out_free_sec:
1317 	security_sk_free(sk);
1318 out_free:
1319 	if (slab != NULL)
1320 		kmem_cache_free(slab, sk);
1321 	else
1322 		kfree(sk);
1323 	return NULL;
1324 }
1325 
1326 static void sk_prot_free(struct proto *prot, struct sock *sk)
1327 {
1328 	struct kmem_cache *slab;
1329 	struct module *owner;
1330 
1331 	owner = prot->owner;
1332 	slab = prot->slab;
1333 
1334 	security_sk_free(sk);
1335 	if (slab != NULL)
1336 		kmem_cache_free(slab, sk);
1337 	else
1338 		kfree(sk);
1339 	module_put(owner);
1340 }
1341 
1342 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
1343 void sock_update_netprioidx(struct sock *sk)
1344 {
1345 	if (in_interrupt())
1346 		return;
1347 
1348 	sk->sk_cgrp_prioidx = task_netprioidx(current);
1349 }
1350 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1351 #endif
1352 
1353 /**
1354  *	sk_alloc - All socket objects are allocated here
1355  *	@net: the applicable net namespace
1356  *	@family: protocol family
1357  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1358  *	@prot: struct proto associated with this new sock instance
1359  */
1360 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1361 		      struct proto *prot)
1362 {
1363 	struct sock *sk;
1364 
1365 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1366 	if (sk) {
1367 		sk->sk_family = family;
1368 		/*
1369 		 * See comment in struct sock definition to understand
1370 		 * why we need sk_prot_creator -acme
1371 		 */
1372 		sk->sk_prot = sk->sk_prot_creator = prot;
1373 		sock_lock_init(sk);
1374 		sock_net_set(sk, get_net(net));
1375 		atomic_set(&sk->sk_wmem_alloc, 1);
1376 
1377 		sock_update_classid(sk);
1378 		sock_update_netprioidx(sk);
1379 	}
1380 
1381 	return sk;
1382 }
1383 EXPORT_SYMBOL(sk_alloc);
1384 
1385 static void __sk_free(struct sock *sk)
1386 {
1387 	struct sk_filter *filter;
1388 
1389 	if (sk->sk_destruct)
1390 		sk->sk_destruct(sk);
1391 
1392 	filter = rcu_dereference_check(sk->sk_filter,
1393 				       atomic_read(&sk->sk_wmem_alloc) == 0);
1394 	if (filter) {
1395 		sk_filter_uncharge(sk, filter);
1396 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1397 	}
1398 
1399 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1400 
1401 	if (atomic_read(&sk->sk_omem_alloc))
1402 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1403 			 __func__, atomic_read(&sk->sk_omem_alloc));
1404 
1405 	if (sk->sk_peer_cred)
1406 		put_cred(sk->sk_peer_cred);
1407 	put_pid(sk->sk_peer_pid);
1408 	put_net(sock_net(sk));
1409 	sk_prot_free(sk->sk_prot_creator, sk);
1410 }
1411 
1412 void sk_free(struct sock *sk)
1413 {
1414 	/*
1415 	 * We subtract one from sk_wmem_alloc and can know if
1416 	 * some packets are still in some tx queue.
1417 	 * If not null, sock_wfree() will call __sk_free(sk) later
1418 	 */
1419 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1420 		__sk_free(sk);
1421 }
1422 EXPORT_SYMBOL(sk_free);
1423 
1424 /*
1425  * Last sock_put should drop reference to sk->sk_net. It has already
1426  * been dropped in sk_change_net. Taking reference to stopping namespace
1427  * is not an option.
1428  * Take reference to a socket to remove it from hash _alive_ and after that
1429  * destroy it in the context of init_net.
1430  */
1431 void sk_release_kernel(struct sock *sk)
1432 {
1433 	if (sk == NULL || sk->sk_socket == NULL)
1434 		return;
1435 
1436 	sock_hold(sk);
1437 	sock_release(sk->sk_socket);
1438 	release_net(sock_net(sk));
1439 	sock_net_set(sk, get_net(&init_net));
1440 	sock_put(sk);
1441 }
1442 EXPORT_SYMBOL(sk_release_kernel);
1443 
1444 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1445 {
1446 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1447 		sock_update_memcg(newsk);
1448 }
1449 
1450 /**
1451  *	sk_clone_lock - clone a socket, and lock its clone
1452  *	@sk: the socket to clone
1453  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1454  *
1455  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1456  */
1457 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1458 {
1459 	struct sock *newsk;
1460 	bool is_charged = true;
1461 
1462 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1463 	if (newsk != NULL) {
1464 		struct sk_filter *filter;
1465 
1466 		sock_copy(newsk, sk);
1467 
1468 		/* SANITY */
1469 		get_net(sock_net(newsk));
1470 		sk_node_init(&newsk->sk_node);
1471 		sock_lock_init(newsk);
1472 		bh_lock_sock(newsk);
1473 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1474 		newsk->sk_backlog.len = 0;
1475 
1476 		atomic_set(&newsk->sk_rmem_alloc, 0);
1477 		/*
1478 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1479 		 */
1480 		atomic_set(&newsk->sk_wmem_alloc, 1);
1481 		atomic_set(&newsk->sk_omem_alloc, 0);
1482 		skb_queue_head_init(&newsk->sk_receive_queue);
1483 		skb_queue_head_init(&newsk->sk_write_queue);
1484 
1485 		spin_lock_init(&newsk->sk_dst_lock);
1486 		rwlock_init(&newsk->sk_callback_lock);
1487 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1488 				af_callback_keys + newsk->sk_family,
1489 				af_family_clock_key_strings[newsk->sk_family]);
1490 
1491 		newsk->sk_dst_cache	= NULL;
1492 		newsk->sk_wmem_queued	= 0;
1493 		newsk->sk_forward_alloc = 0;
1494 		newsk->sk_send_head	= NULL;
1495 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1496 
1497 		sock_reset_flag(newsk, SOCK_DONE);
1498 		skb_queue_head_init(&newsk->sk_error_queue);
1499 
1500 		filter = rcu_dereference_protected(newsk->sk_filter, 1);
1501 		if (filter != NULL)
1502 			/* though it's an empty new sock, the charging may fail
1503 			 * if sysctl_optmem_max was changed between creation of
1504 			 * original socket and cloning
1505 			 */
1506 			is_charged = sk_filter_charge(newsk, filter);
1507 
1508 		if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk))) {
1509 			/* It is still raw copy of parent, so invalidate
1510 			 * destructor and make plain sk_free() */
1511 			newsk->sk_destruct = NULL;
1512 			bh_unlock_sock(newsk);
1513 			sk_free(newsk);
1514 			newsk = NULL;
1515 			goto out;
1516 		}
1517 
1518 		newsk->sk_err	   = 0;
1519 		newsk->sk_priority = 0;
1520 		/*
1521 		 * Before updating sk_refcnt, we must commit prior changes to memory
1522 		 * (Documentation/RCU/rculist_nulls.txt for details)
1523 		 */
1524 		smp_wmb();
1525 		atomic_set(&newsk->sk_refcnt, 2);
1526 
1527 		/*
1528 		 * Increment the counter in the same struct proto as the master
1529 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1530 		 * is the same as sk->sk_prot->socks, as this field was copied
1531 		 * with memcpy).
1532 		 *
1533 		 * This _changes_ the previous behaviour, where
1534 		 * tcp_create_openreq_child always was incrementing the
1535 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1536 		 * to be taken into account in all callers. -acme
1537 		 */
1538 		sk_refcnt_debug_inc(newsk);
1539 		sk_set_socket(newsk, NULL);
1540 		newsk->sk_wq = NULL;
1541 
1542 		sk_update_clone(sk, newsk);
1543 
1544 		if (newsk->sk_prot->sockets_allocated)
1545 			sk_sockets_allocated_inc(newsk);
1546 
1547 		if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1548 			net_enable_timestamp();
1549 	}
1550 out:
1551 	return newsk;
1552 }
1553 EXPORT_SYMBOL_GPL(sk_clone_lock);
1554 
1555 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1556 {
1557 	__sk_dst_set(sk, dst);
1558 	sk->sk_route_caps = dst->dev->features;
1559 	if (sk->sk_route_caps & NETIF_F_GSO)
1560 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1561 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1562 	if (sk_can_gso(sk)) {
1563 		if (dst->header_len) {
1564 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1565 		} else {
1566 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1567 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1568 			sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1569 		}
1570 	}
1571 }
1572 EXPORT_SYMBOL_GPL(sk_setup_caps);
1573 
1574 /*
1575  *	Simple resource managers for sockets.
1576  */
1577 
1578 
1579 /*
1580  * Write buffer destructor automatically called from kfree_skb.
1581  */
1582 void sock_wfree(struct sk_buff *skb)
1583 {
1584 	struct sock *sk = skb->sk;
1585 	unsigned int len = skb->truesize;
1586 
1587 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1588 		/*
1589 		 * Keep a reference on sk_wmem_alloc, this will be released
1590 		 * after sk_write_space() call
1591 		 */
1592 		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1593 		sk->sk_write_space(sk);
1594 		len = 1;
1595 	}
1596 	/*
1597 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1598 	 * could not do because of in-flight packets
1599 	 */
1600 	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1601 		__sk_free(sk);
1602 }
1603 EXPORT_SYMBOL(sock_wfree);
1604 
1605 void skb_orphan_partial(struct sk_buff *skb)
1606 {
1607 	/* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
1608 	 * so we do not completely orphan skb, but transfert all
1609 	 * accounted bytes but one, to avoid unexpected reorders.
1610 	 */
1611 	if (skb->destructor == sock_wfree
1612 #ifdef CONFIG_INET
1613 	    || skb->destructor == tcp_wfree
1614 #endif
1615 		) {
1616 		atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
1617 		skb->truesize = 1;
1618 	} else {
1619 		skb_orphan(skb);
1620 	}
1621 }
1622 EXPORT_SYMBOL(skb_orphan_partial);
1623 
1624 /*
1625  * Read buffer destructor automatically called from kfree_skb.
1626  */
1627 void sock_rfree(struct sk_buff *skb)
1628 {
1629 	struct sock *sk = skb->sk;
1630 	unsigned int len = skb->truesize;
1631 
1632 	atomic_sub(len, &sk->sk_rmem_alloc);
1633 	sk_mem_uncharge(sk, len);
1634 }
1635 EXPORT_SYMBOL(sock_rfree);
1636 
1637 void sock_efree(struct sk_buff *skb)
1638 {
1639 	sock_put(skb->sk);
1640 }
1641 EXPORT_SYMBOL(sock_efree);
1642 
1643 #ifdef CONFIG_INET
1644 void sock_edemux(struct sk_buff *skb)
1645 {
1646 	struct sock *sk = skb->sk;
1647 
1648 	if (sk->sk_state == TCP_TIME_WAIT)
1649 		inet_twsk_put(inet_twsk(sk));
1650 	else
1651 		sock_put(sk);
1652 }
1653 EXPORT_SYMBOL(sock_edemux);
1654 #endif
1655 
1656 kuid_t sock_i_uid(struct sock *sk)
1657 {
1658 	kuid_t uid;
1659 
1660 	read_lock_bh(&sk->sk_callback_lock);
1661 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
1662 	read_unlock_bh(&sk->sk_callback_lock);
1663 	return uid;
1664 }
1665 EXPORT_SYMBOL(sock_i_uid);
1666 
1667 unsigned long sock_i_ino(struct sock *sk)
1668 {
1669 	unsigned long ino;
1670 
1671 	read_lock_bh(&sk->sk_callback_lock);
1672 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1673 	read_unlock_bh(&sk->sk_callback_lock);
1674 	return ino;
1675 }
1676 EXPORT_SYMBOL(sock_i_ino);
1677 
1678 /*
1679  * Allocate a skb from the socket's send buffer.
1680  */
1681 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1682 			     gfp_t priority)
1683 {
1684 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1685 		struct sk_buff *skb = alloc_skb(size, priority);
1686 		if (skb) {
1687 			skb_set_owner_w(skb, sk);
1688 			return skb;
1689 		}
1690 	}
1691 	return NULL;
1692 }
1693 EXPORT_SYMBOL(sock_wmalloc);
1694 
1695 /*
1696  * Allocate a memory block from the socket's option memory buffer.
1697  */
1698 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1699 {
1700 	if ((unsigned int)size <= sysctl_optmem_max &&
1701 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1702 		void *mem;
1703 		/* First do the add, to avoid the race if kmalloc
1704 		 * might sleep.
1705 		 */
1706 		atomic_add(size, &sk->sk_omem_alloc);
1707 		mem = kmalloc(size, priority);
1708 		if (mem)
1709 			return mem;
1710 		atomic_sub(size, &sk->sk_omem_alloc);
1711 	}
1712 	return NULL;
1713 }
1714 EXPORT_SYMBOL(sock_kmalloc);
1715 
1716 /*
1717  * Free an option memory block.
1718  */
1719 void sock_kfree_s(struct sock *sk, void *mem, int size)
1720 {
1721 	kfree(mem);
1722 	atomic_sub(size, &sk->sk_omem_alloc);
1723 }
1724 EXPORT_SYMBOL(sock_kfree_s);
1725 
1726 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1727    I think, these locks should be removed for datagram sockets.
1728  */
1729 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1730 {
1731 	DEFINE_WAIT(wait);
1732 
1733 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1734 	for (;;) {
1735 		if (!timeo)
1736 			break;
1737 		if (signal_pending(current))
1738 			break;
1739 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1740 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1741 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1742 			break;
1743 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1744 			break;
1745 		if (sk->sk_err)
1746 			break;
1747 		timeo = schedule_timeout(timeo);
1748 	}
1749 	finish_wait(sk_sleep(sk), &wait);
1750 	return timeo;
1751 }
1752 
1753 
1754 /*
1755  *	Generic send/receive buffer handlers
1756  */
1757 
1758 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1759 				     unsigned long data_len, int noblock,
1760 				     int *errcode, int max_page_order)
1761 {
1762 	struct sk_buff *skb;
1763 	long timeo;
1764 	int err;
1765 
1766 	timeo = sock_sndtimeo(sk, noblock);
1767 	for (;;) {
1768 		err = sock_error(sk);
1769 		if (err != 0)
1770 			goto failure;
1771 
1772 		err = -EPIPE;
1773 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1774 			goto failure;
1775 
1776 		if (sk_wmem_alloc_get(sk) < sk->sk_sndbuf)
1777 			break;
1778 
1779 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1780 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1781 		err = -EAGAIN;
1782 		if (!timeo)
1783 			goto failure;
1784 		if (signal_pending(current))
1785 			goto interrupted;
1786 		timeo = sock_wait_for_wmem(sk, timeo);
1787 	}
1788 	skb = alloc_skb_with_frags(header_len, data_len, max_page_order,
1789 				   errcode, sk->sk_allocation);
1790 	if (skb)
1791 		skb_set_owner_w(skb, sk);
1792 	return skb;
1793 
1794 interrupted:
1795 	err = sock_intr_errno(timeo);
1796 failure:
1797 	*errcode = err;
1798 	return NULL;
1799 }
1800 EXPORT_SYMBOL(sock_alloc_send_pskb);
1801 
1802 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1803 				    int noblock, int *errcode)
1804 {
1805 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
1806 }
1807 EXPORT_SYMBOL(sock_alloc_send_skb);
1808 
1809 /* On 32bit arches, an skb frag is limited to 2^15 */
1810 #define SKB_FRAG_PAGE_ORDER	get_order(32768)
1811 
1812 /**
1813  * skb_page_frag_refill - check that a page_frag contains enough room
1814  * @sz: minimum size of the fragment we want to get
1815  * @pfrag: pointer to page_frag
1816  * @gfp: priority for memory allocation
1817  *
1818  * Note: While this allocator tries to use high order pages, there is
1819  * no guarantee that allocations succeed. Therefore, @sz MUST be
1820  * less or equal than PAGE_SIZE.
1821  */
1822 bool skb_page_frag_refill(unsigned int sz, struct page_frag *pfrag, gfp_t gfp)
1823 {
1824 	if (pfrag->page) {
1825 		if (atomic_read(&pfrag->page->_count) == 1) {
1826 			pfrag->offset = 0;
1827 			return true;
1828 		}
1829 		if (pfrag->offset + sz <= pfrag->size)
1830 			return true;
1831 		put_page(pfrag->page);
1832 	}
1833 
1834 	pfrag->offset = 0;
1835 	if (SKB_FRAG_PAGE_ORDER) {
1836 		pfrag->page = alloc_pages(gfp | __GFP_COMP |
1837 					  __GFP_NOWARN | __GFP_NORETRY,
1838 					  SKB_FRAG_PAGE_ORDER);
1839 		if (likely(pfrag->page)) {
1840 			pfrag->size = PAGE_SIZE << SKB_FRAG_PAGE_ORDER;
1841 			return true;
1842 		}
1843 	}
1844 	pfrag->page = alloc_page(gfp);
1845 	if (likely(pfrag->page)) {
1846 		pfrag->size = PAGE_SIZE;
1847 		return true;
1848 	}
1849 	return false;
1850 }
1851 EXPORT_SYMBOL(skb_page_frag_refill);
1852 
1853 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
1854 {
1855 	if (likely(skb_page_frag_refill(32U, pfrag, sk->sk_allocation)))
1856 		return true;
1857 
1858 	sk_enter_memory_pressure(sk);
1859 	sk_stream_moderate_sndbuf(sk);
1860 	return false;
1861 }
1862 EXPORT_SYMBOL(sk_page_frag_refill);
1863 
1864 static void __lock_sock(struct sock *sk)
1865 	__releases(&sk->sk_lock.slock)
1866 	__acquires(&sk->sk_lock.slock)
1867 {
1868 	DEFINE_WAIT(wait);
1869 
1870 	for (;;) {
1871 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1872 					TASK_UNINTERRUPTIBLE);
1873 		spin_unlock_bh(&sk->sk_lock.slock);
1874 		schedule();
1875 		spin_lock_bh(&sk->sk_lock.slock);
1876 		if (!sock_owned_by_user(sk))
1877 			break;
1878 	}
1879 	finish_wait(&sk->sk_lock.wq, &wait);
1880 }
1881 
1882 static void __release_sock(struct sock *sk)
1883 	__releases(&sk->sk_lock.slock)
1884 	__acquires(&sk->sk_lock.slock)
1885 {
1886 	struct sk_buff *skb = sk->sk_backlog.head;
1887 
1888 	do {
1889 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1890 		bh_unlock_sock(sk);
1891 
1892 		do {
1893 			struct sk_buff *next = skb->next;
1894 
1895 			prefetch(next);
1896 			WARN_ON_ONCE(skb_dst_is_noref(skb));
1897 			skb->next = NULL;
1898 			sk_backlog_rcv(sk, skb);
1899 
1900 			/*
1901 			 * We are in process context here with softirqs
1902 			 * disabled, use cond_resched_softirq() to preempt.
1903 			 * This is safe to do because we've taken the backlog
1904 			 * queue private:
1905 			 */
1906 			cond_resched_softirq();
1907 
1908 			skb = next;
1909 		} while (skb != NULL);
1910 
1911 		bh_lock_sock(sk);
1912 	} while ((skb = sk->sk_backlog.head) != NULL);
1913 
1914 	/*
1915 	 * Doing the zeroing here guarantee we can not loop forever
1916 	 * while a wild producer attempts to flood us.
1917 	 */
1918 	sk->sk_backlog.len = 0;
1919 }
1920 
1921 /**
1922  * sk_wait_data - wait for data to arrive at sk_receive_queue
1923  * @sk:    sock to wait on
1924  * @timeo: for how long
1925  *
1926  * Now socket state including sk->sk_err is changed only under lock,
1927  * hence we may omit checks after joining wait queue.
1928  * We check receive queue before schedule() only as optimization;
1929  * it is very likely that release_sock() added new data.
1930  */
1931 int sk_wait_data(struct sock *sk, long *timeo)
1932 {
1933 	int rc;
1934 	DEFINE_WAIT(wait);
1935 
1936 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1937 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1938 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1939 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1940 	finish_wait(sk_sleep(sk), &wait);
1941 	return rc;
1942 }
1943 EXPORT_SYMBOL(sk_wait_data);
1944 
1945 /**
1946  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1947  *	@sk: socket
1948  *	@size: memory size to allocate
1949  *	@kind: allocation type
1950  *
1951  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1952  *	rmem allocation. This function assumes that protocols which have
1953  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1954  */
1955 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1956 {
1957 	struct proto *prot = sk->sk_prot;
1958 	int amt = sk_mem_pages(size);
1959 	long allocated;
1960 	int parent_status = UNDER_LIMIT;
1961 
1962 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1963 
1964 	allocated = sk_memory_allocated_add(sk, amt, &parent_status);
1965 
1966 	/* Under limit. */
1967 	if (parent_status == UNDER_LIMIT &&
1968 			allocated <= sk_prot_mem_limits(sk, 0)) {
1969 		sk_leave_memory_pressure(sk);
1970 		return 1;
1971 	}
1972 
1973 	/* Under pressure. (we or our parents) */
1974 	if ((parent_status > SOFT_LIMIT) ||
1975 			allocated > sk_prot_mem_limits(sk, 1))
1976 		sk_enter_memory_pressure(sk);
1977 
1978 	/* Over hard limit (we or our parents) */
1979 	if ((parent_status == OVER_LIMIT) ||
1980 			(allocated > sk_prot_mem_limits(sk, 2)))
1981 		goto suppress_allocation;
1982 
1983 	/* guarantee minimum buffer size under pressure */
1984 	if (kind == SK_MEM_RECV) {
1985 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1986 			return 1;
1987 
1988 	} else { /* SK_MEM_SEND */
1989 		if (sk->sk_type == SOCK_STREAM) {
1990 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1991 				return 1;
1992 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1993 			   prot->sysctl_wmem[0])
1994 				return 1;
1995 	}
1996 
1997 	if (sk_has_memory_pressure(sk)) {
1998 		int alloc;
1999 
2000 		if (!sk_under_memory_pressure(sk))
2001 			return 1;
2002 		alloc = sk_sockets_allocated_read_positive(sk);
2003 		if (sk_prot_mem_limits(sk, 2) > alloc *
2004 		    sk_mem_pages(sk->sk_wmem_queued +
2005 				 atomic_read(&sk->sk_rmem_alloc) +
2006 				 sk->sk_forward_alloc))
2007 			return 1;
2008 	}
2009 
2010 suppress_allocation:
2011 
2012 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
2013 		sk_stream_moderate_sndbuf(sk);
2014 
2015 		/* Fail only if socket is _under_ its sndbuf.
2016 		 * In this case we cannot block, so that we have to fail.
2017 		 */
2018 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
2019 			return 1;
2020 	}
2021 
2022 	trace_sock_exceed_buf_limit(sk, prot, allocated);
2023 
2024 	/* Alas. Undo changes. */
2025 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
2026 
2027 	sk_memory_allocated_sub(sk, amt);
2028 
2029 	return 0;
2030 }
2031 EXPORT_SYMBOL(__sk_mem_schedule);
2032 
2033 /**
2034  *	__sk_reclaim - reclaim memory_allocated
2035  *	@sk: socket
2036  */
2037 void __sk_mem_reclaim(struct sock *sk)
2038 {
2039 	sk_memory_allocated_sub(sk,
2040 				sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
2041 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
2042 
2043 	if (sk_under_memory_pressure(sk) &&
2044 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
2045 		sk_leave_memory_pressure(sk);
2046 }
2047 EXPORT_SYMBOL(__sk_mem_reclaim);
2048 
2049 
2050 /*
2051  * Set of default routines for initialising struct proto_ops when
2052  * the protocol does not support a particular function. In certain
2053  * cases where it makes no sense for a protocol to have a "do nothing"
2054  * function, some default processing is provided.
2055  */
2056 
2057 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
2058 {
2059 	return -EOPNOTSUPP;
2060 }
2061 EXPORT_SYMBOL(sock_no_bind);
2062 
2063 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
2064 		    int len, int flags)
2065 {
2066 	return -EOPNOTSUPP;
2067 }
2068 EXPORT_SYMBOL(sock_no_connect);
2069 
2070 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
2071 {
2072 	return -EOPNOTSUPP;
2073 }
2074 EXPORT_SYMBOL(sock_no_socketpair);
2075 
2076 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
2077 {
2078 	return -EOPNOTSUPP;
2079 }
2080 EXPORT_SYMBOL(sock_no_accept);
2081 
2082 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
2083 		    int *len, int peer)
2084 {
2085 	return -EOPNOTSUPP;
2086 }
2087 EXPORT_SYMBOL(sock_no_getname);
2088 
2089 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
2090 {
2091 	return 0;
2092 }
2093 EXPORT_SYMBOL(sock_no_poll);
2094 
2095 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
2096 {
2097 	return -EOPNOTSUPP;
2098 }
2099 EXPORT_SYMBOL(sock_no_ioctl);
2100 
2101 int sock_no_listen(struct socket *sock, int backlog)
2102 {
2103 	return -EOPNOTSUPP;
2104 }
2105 EXPORT_SYMBOL(sock_no_listen);
2106 
2107 int sock_no_shutdown(struct socket *sock, int how)
2108 {
2109 	return -EOPNOTSUPP;
2110 }
2111 EXPORT_SYMBOL(sock_no_shutdown);
2112 
2113 int sock_no_setsockopt(struct socket *sock, int level, int optname,
2114 		    char __user *optval, unsigned int optlen)
2115 {
2116 	return -EOPNOTSUPP;
2117 }
2118 EXPORT_SYMBOL(sock_no_setsockopt);
2119 
2120 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2121 		    char __user *optval, int __user *optlen)
2122 {
2123 	return -EOPNOTSUPP;
2124 }
2125 EXPORT_SYMBOL(sock_no_getsockopt);
2126 
2127 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2128 		    size_t len)
2129 {
2130 	return -EOPNOTSUPP;
2131 }
2132 EXPORT_SYMBOL(sock_no_sendmsg);
2133 
2134 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2135 		    size_t len, int flags)
2136 {
2137 	return -EOPNOTSUPP;
2138 }
2139 EXPORT_SYMBOL(sock_no_recvmsg);
2140 
2141 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2142 {
2143 	/* Mirror missing mmap method error code */
2144 	return -ENODEV;
2145 }
2146 EXPORT_SYMBOL(sock_no_mmap);
2147 
2148 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2149 {
2150 	ssize_t res;
2151 	struct msghdr msg = {.msg_flags = flags};
2152 	struct kvec iov;
2153 	char *kaddr = kmap(page);
2154 	iov.iov_base = kaddr + offset;
2155 	iov.iov_len = size;
2156 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2157 	kunmap(page);
2158 	return res;
2159 }
2160 EXPORT_SYMBOL(sock_no_sendpage);
2161 
2162 /*
2163  *	Default Socket Callbacks
2164  */
2165 
2166 static void sock_def_wakeup(struct sock *sk)
2167 {
2168 	struct socket_wq *wq;
2169 
2170 	rcu_read_lock();
2171 	wq = rcu_dereference(sk->sk_wq);
2172 	if (wq_has_sleeper(wq))
2173 		wake_up_interruptible_all(&wq->wait);
2174 	rcu_read_unlock();
2175 }
2176 
2177 static void sock_def_error_report(struct sock *sk)
2178 {
2179 	struct socket_wq *wq;
2180 
2181 	rcu_read_lock();
2182 	wq = rcu_dereference(sk->sk_wq);
2183 	if (wq_has_sleeper(wq))
2184 		wake_up_interruptible_poll(&wq->wait, POLLERR);
2185 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2186 	rcu_read_unlock();
2187 }
2188 
2189 static void sock_def_readable(struct sock *sk)
2190 {
2191 	struct socket_wq *wq;
2192 
2193 	rcu_read_lock();
2194 	wq = rcu_dereference(sk->sk_wq);
2195 	if (wq_has_sleeper(wq))
2196 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2197 						POLLRDNORM | POLLRDBAND);
2198 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2199 	rcu_read_unlock();
2200 }
2201 
2202 static void sock_def_write_space(struct sock *sk)
2203 {
2204 	struct socket_wq *wq;
2205 
2206 	rcu_read_lock();
2207 
2208 	/* Do not wake up a writer until he can make "significant"
2209 	 * progress.  --DaveM
2210 	 */
2211 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2212 		wq = rcu_dereference(sk->sk_wq);
2213 		if (wq_has_sleeper(wq))
2214 			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2215 						POLLWRNORM | POLLWRBAND);
2216 
2217 		/* Should agree with poll, otherwise some programs break */
2218 		if (sock_writeable(sk))
2219 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2220 	}
2221 
2222 	rcu_read_unlock();
2223 }
2224 
2225 static void sock_def_destruct(struct sock *sk)
2226 {
2227 	kfree(sk->sk_protinfo);
2228 }
2229 
2230 void sk_send_sigurg(struct sock *sk)
2231 {
2232 	if (sk->sk_socket && sk->sk_socket->file)
2233 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2234 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2235 }
2236 EXPORT_SYMBOL(sk_send_sigurg);
2237 
2238 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2239 		    unsigned long expires)
2240 {
2241 	if (!mod_timer(timer, expires))
2242 		sock_hold(sk);
2243 }
2244 EXPORT_SYMBOL(sk_reset_timer);
2245 
2246 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2247 {
2248 	if (del_timer(timer))
2249 		__sock_put(sk);
2250 }
2251 EXPORT_SYMBOL(sk_stop_timer);
2252 
2253 void sock_init_data(struct socket *sock, struct sock *sk)
2254 {
2255 	skb_queue_head_init(&sk->sk_receive_queue);
2256 	skb_queue_head_init(&sk->sk_write_queue);
2257 	skb_queue_head_init(&sk->sk_error_queue);
2258 
2259 	sk->sk_send_head	=	NULL;
2260 
2261 	init_timer(&sk->sk_timer);
2262 
2263 	sk->sk_allocation	=	GFP_KERNEL;
2264 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2265 	sk->sk_sndbuf		=	sysctl_wmem_default;
2266 	sk->sk_state		=	TCP_CLOSE;
2267 	sk_set_socket(sk, sock);
2268 
2269 	sock_set_flag(sk, SOCK_ZAPPED);
2270 
2271 	if (sock) {
2272 		sk->sk_type	=	sock->type;
2273 		sk->sk_wq	=	sock->wq;
2274 		sock->sk	=	sk;
2275 	} else
2276 		sk->sk_wq	=	NULL;
2277 
2278 	spin_lock_init(&sk->sk_dst_lock);
2279 	rwlock_init(&sk->sk_callback_lock);
2280 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2281 			af_callback_keys + sk->sk_family,
2282 			af_family_clock_key_strings[sk->sk_family]);
2283 
2284 	sk->sk_state_change	=	sock_def_wakeup;
2285 	sk->sk_data_ready	=	sock_def_readable;
2286 	sk->sk_write_space	=	sock_def_write_space;
2287 	sk->sk_error_report	=	sock_def_error_report;
2288 	sk->sk_destruct		=	sock_def_destruct;
2289 
2290 	sk->sk_frag.page	=	NULL;
2291 	sk->sk_frag.offset	=	0;
2292 	sk->sk_peek_off		=	-1;
2293 
2294 	sk->sk_peer_pid 	=	NULL;
2295 	sk->sk_peer_cred	=	NULL;
2296 	sk->sk_write_pending	=	0;
2297 	sk->sk_rcvlowat		=	1;
2298 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2299 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2300 
2301 	sk->sk_stamp = ktime_set(-1L, 0);
2302 
2303 #ifdef CONFIG_NET_RX_BUSY_POLL
2304 	sk->sk_napi_id		=	0;
2305 	sk->sk_ll_usec		=	sysctl_net_busy_read;
2306 #endif
2307 
2308 	sk->sk_max_pacing_rate = ~0U;
2309 	sk->sk_pacing_rate = ~0U;
2310 	/*
2311 	 * Before updating sk_refcnt, we must commit prior changes to memory
2312 	 * (Documentation/RCU/rculist_nulls.txt for details)
2313 	 */
2314 	smp_wmb();
2315 	atomic_set(&sk->sk_refcnt, 1);
2316 	atomic_set(&sk->sk_drops, 0);
2317 }
2318 EXPORT_SYMBOL(sock_init_data);
2319 
2320 void lock_sock_nested(struct sock *sk, int subclass)
2321 {
2322 	might_sleep();
2323 	spin_lock_bh(&sk->sk_lock.slock);
2324 	if (sk->sk_lock.owned)
2325 		__lock_sock(sk);
2326 	sk->sk_lock.owned = 1;
2327 	spin_unlock(&sk->sk_lock.slock);
2328 	/*
2329 	 * The sk_lock has mutex_lock() semantics here:
2330 	 */
2331 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2332 	local_bh_enable();
2333 }
2334 EXPORT_SYMBOL(lock_sock_nested);
2335 
2336 void release_sock(struct sock *sk)
2337 {
2338 	/*
2339 	 * The sk_lock has mutex_unlock() semantics:
2340 	 */
2341 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2342 
2343 	spin_lock_bh(&sk->sk_lock.slock);
2344 	if (sk->sk_backlog.tail)
2345 		__release_sock(sk);
2346 
2347 	/* Warning : release_cb() might need to release sk ownership,
2348 	 * ie call sock_release_ownership(sk) before us.
2349 	 */
2350 	if (sk->sk_prot->release_cb)
2351 		sk->sk_prot->release_cb(sk);
2352 
2353 	sock_release_ownership(sk);
2354 	if (waitqueue_active(&sk->sk_lock.wq))
2355 		wake_up(&sk->sk_lock.wq);
2356 	spin_unlock_bh(&sk->sk_lock.slock);
2357 }
2358 EXPORT_SYMBOL(release_sock);
2359 
2360 /**
2361  * lock_sock_fast - fast version of lock_sock
2362  * @sk: socket
2363  *
2364  * This version should be used for very small section, where process wont block
2365  * return false if fast path is taken
2366  *   sk_lock.slock locked, owned = 0, BH disabled
2367  * return true if slow path is taken
2368  *   sk_lock.slock unlocked, owned = 1, BH enabled
2369  */
2370 bool lock_sock_fast(struct sock *sk)
2371 {
2372 	might_sleep();
2373 	spin_lock_bh(&sk->sk_lock.slock);
2374 
2375 	if (!sk->sk_lock.owned)
2376 		/*
2377 		 * Note : We must disable BH
2378 		 */
2379 		return false;
2380 
2381 	__lock_sock(sk);
2382 	sk->sk_lock.owned = 1;
2383 	spin_unlock(&sk->sk_lock.slock);
2384 	/*
2385 	 * The sk_lock has mutex_lock() semantics here:
2386 	 */
2387 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2388 	local_bh_enable();
2389 	return true;
2390 }
2391 EXPORT_SYMBOL(lock_sock_fast);
2392 
2393 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2394 {
2395 	struct timeval tv;
2396 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2397 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2398 	tv = ktime_to_timeval(sk->sk_stamp);
2399 	if (tv.tv_sec == -1)
2400 		return -ENOENT;
2401 	if (tv.tv_sec == 0) {
2402 		sk->sk_stamp = ktime_get_real();
2403 		tv = ktime_to_timeval(sk->sk_stamp);
2404 	}
2405 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2406 }
2407 EXPORT_SYMBOL(sock_get_timestamp);
2408 
2409 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2410 {
2411 	struct timespec ts;
2412 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2413 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2414 	ts = ktime_to_timespec(sk->sk_stamp);
2415 	if (ts.tv_sec == -1)
2416 		return -ENOENT;
2417 	if (ts.tv_sec == 0) {
2418 		sk->sk_stamp = ktime_get_real();
2419 		ts = ktime_to_timespec(sk->sk_stamp);
2420 	}
2421 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2422 }
2423 EXPORT_SYMBOL(sock_get_timestampns);
2424 
2425 void sock_enable_timestamp(struct sock *sk, int flag)
2426 {
2427 	if (!sock_flag(sk, flag)) {
2428 		unsigned long previous_flags = sk->sk_flags;
2429 
2430 		sock_set_flag(sk, flag);
2431 		/*
2432 		 * we just set one of the two flags which require net
2433 		 * time stamping, but time stamping might have been on
2434 		 * already because of the other one
2435 		 */
2436 		if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2437 			net_enable_timestamp();
2438 	}
2439 }
2440 
2441 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
2442 		       int level, int type)
2443 {
2444 	struct sock_exterr_skb *serr;
2445 	struct sk_buff *skb;
2446 	int copied, err;
2447 
2448 	err = -EAGAIN;
2449 	skb = sock_dequeue_err_skb(sk);
2450 	if (skb == NULL)
2451 		goto out;
2452 
2453 	copied = skb->len;
2454 	if (copied > len) {
2455 		msg->msg_flags |= MSG_TRUNC;
2456 		copied = len;
2457 	}
2458 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
2459 	if (err)
2460 		goto out_free_skb;
2461 
2462 	sock_recv_timestamp(msg, sk, skb);
2463 
2464 	serr = SKB_EXT_ERR(skb);
2465 	put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee);
2466 
2467 	msg->msg_flags |= MSG_ERRQUEUE;
2468 	err = copied;
2469 
2470 out_free_skb:
2471 	kfree_skb(skb);
2472 out:
2473 	return err;
2474 }
2475 EXPORT_SYMBOL(sock_recv_errqueue);
2476 
2477 /*
2478  *	Get a socket option on an socket.
2479  *
2480  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2481  *	asynchronous errors should be reported by getsockopt. We assume
2482  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2483  */
2484 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2485 			   char __user *optval, int __user *optlen)
2486 {
2487 	struct sock *sk = sock->sk;
2488 
2489 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2490 }
2491 EXPORT_SYMBOL(sock_common_getsockopt);
2492 
2493 #ifdef CONFIG_COMPAT
2494 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2495 				  char __user *optval, int __user *optlen)
2496 {
2497 	struct sock *sk = sock->sk;
2498 
2499 	if (sk->sk_prot->compat_getsockopt != NULL)
2500 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2501 						      optval, optlen);
2502 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2503 }
2504 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2505 #endif
2506 
2507 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2508 			struct msghdr *msg, size_t size, int flags)
2509 {
2510 	struct sock *sk = sock->sk;
2511 	int addr_len = 0;
2512 	int err;
2513 
2514 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2515 				   flags & ~MSG_DONTWAIT, &addr_len);
2516 	if (err >= 0)
2517 		msg->msg_namelen = addr_len;
2518 	return err;
2519 }
2520 EXPORT_SYMBOL(sock_common_recvmsg);
2521 
2522 /*
2523  *	Set socket options on an inet socket.
2524  */
2525 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2526 			   char __user *optval, unsigned int optlen)
2527 {
2528 	struct sock *sk = sock->sk;
2529 
2530 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2531 }
2532 EXPORT_SYMBOL(sock_common_setsockopt);
2533 
2534 #ifdef CONFIG_COMPAT
2535 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2536 				  char __user *optval, unsigned int optlen)
2537 {
2538 	struct sock *sk = sock->sk;
2539 
2540 	if (sk->sk_prot->compat_setsockopt != NULL)
2541 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2542 						      optval, optlen);
2543 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2544 }
2545 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2546 #endif
2547 
2548 void sk_common_release(struct sock *sk)
2549 {
2550 	if (sk->sk_prot->destroy)
2551 		sk->sk_prot->destroy(sk);
2552 
2553 	/*
2554 	 * Observation: when sock_common_release is called, processes have
2555 	 * no access to socket. But net still has.
2556 	 * Step one, detach it from networking:
2557 	 *
2558 	 * A. Remove from hash tables.
2559 	 */
2560 
2561 	sk->sk_prot->unhash(sk);
2562 
2563 	/*
2564 	 * In this point socket cannot receive new packets, but it is possible
2565 	 * that some packets are in flight because some CPU runs receiver and
2566 	 * did hash table lookup before we unhashed socket. They will achieve
2567 	 * receive queue and will be purged by socket destructor.
2568 	 *
2569 	 * Also we still have packets pending on receive queue and probably,
2570 	 * our own packets waiting in device queues. sock_destroy will drain
2571 	 * receive queue, but transmitted packets will delay socket destruction
2572 	 * until the last reference will be released.
2573 	 */
2574 
2575 	sock_orphan(sk);
2576 
2577 	xfrm_sk_free_policy(sk);
2578 
2579 	sk_refcnt_debug_release(sk);
2580 
2581 	if (sk->sk_frag.page) {
2582 		put_page(sk->sk_frag.page);
2583 		sk->sk_frag.page = NULL;
2584 	}
2585 
2586 	sock_put(sk);
2587 }
2588 EXPORT_SYMBOL(sk_common_release);
2589 
2590 #ifdef CONFIG_PROC_FS
2591 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2592 struct prot_inuse {
2593 	int val[PROTO_INUSE_NR];
2594 };
2595 
2596 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2597 
2598 #ifdef CONFIG_NET_NS
2599 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2600 {
2601 	__this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2602 }
2603 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2604 
2605 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2606 {
2607 	int cpu, idx = prot->inuse_idx;
2608 	int res = 0;
2609 
2610 	for_each_possible_cpu(cpu)
2611 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2612 
2613 	return res >= 0 ? res : 0;
2614 }
2615 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2616 
2617 static int __net_init sock_inuse_init_net(struct net *net)
2618 {
2619 	net->core.inuse = alloc_percpu(struct prot_inuse);
2620 	return net->core.inuse ? 0 : -ENOMEM;
2621 }
2622 
2623 static void __net_exit sock_inuse_exit_net(struct net *net)
2624 {
2625 	free_percpu(net->core.inuse);
2626 }
2627 
2628 static struct pernet_operations net_inuse_ops = {
2629 	.init = sock_inuse_init_net,
2630 	.exit = sock_inuse_exit_net,
2631 };
2632 
2633 static __init int net_inuse_init(void)
2634 {
2635 	if (register_pernet_subsys(&net_inuse_ops))
2636 		panic("Cannot initialize net inuse counters");
2637 
2638 	return 0;
2639 }
2640 
2641 core_initcall(net_inuse_init);
2642 #else
2643 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2644 
2645 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2646 {
2647 	__this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2648 }
2649 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2650 
2651 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2652 {
2653 	int cpu, idx = prot->inuse_idx;
2654 	int res = 0;
2655 
2656 	for_each_possible_cpu(cpu)
2657 		res += per_cpu(prot_inuse, cpu).val[idx];
2658 
2659 	return res >= 0 ? res : 0;
2660 }
2661 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2662 #endif
2663 
2664 static void assign_proto_idx(struct proto *prot)
2665 {
2666 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2667 
2668 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2669 		pr_err("PROTO_INUSE_NR exhausted\n");
2670 		return;
2671 	}
2672 
2673 	set_bit(prot->inuse_idx, proto_inuse_idx);
2674 }
2675 
2676 static void release_proto_idx(struct proto *prot)
2677 {
2678 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2679 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2680 }
2681 #else
2682 static inline void assign_proto_idx(struct proto *prot)
2683 {
2684 }
2685 
2686 static inline void release_proto_idx(struct proto *prot)
2687 {
2688 }
2689 #endif
2690 
2691 int proto_register(struct proto *prot, int alloc_slab)
2692 {
2693 	if (alloc_slab) {
2694 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2695 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2696 					NULL);
2697 
2698 		if (prot->slab == NULL) {
2699 			pr_crit("%s: Can't create sock SLAB cache!\n",
2700 				prot->name);
2701 			goto out;
2702 		}
2703 
2704 		if (prot->rsk_prot != NULL) {
2705 			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2706 			if (prot->rsk_prot->slab_name == NULL)
2707 				goto out_free_sock_slab;
2708 
2709 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2710 								 prot->rsk_prot->obj_size, 0,
2711 								 SLAB_HWCACHE_ALIGN, NULL);
2712 
2713 			if (prot->rsk_prot->slab == NULL) {
2714 				pr_crit("%s: Can't create request sock SLAB cache!\n",
2715 					prot->name);
2716 				goto out_free_request_sock_slab_name;
2717 			}
2718 		}
2719 
2720 		if (prot->twsk_prot != NULL) {
2721 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2722 
2723 			if (prot->twsk_prot->twsk_slab_name == NULL)
2724 				goto out_free_request_sock_slab;
2725 
2726 			prot->twsk_prot->twsk_slab =
2727 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2728 						  prot->twsk_prot->twsk_obj_size,
2729 						  0,
2730 						  SLAB_HWCACHE_ALIGN |
2731 							prot->slab_flags,
2732 						  NULL);
2733 			if (prot->twsk_prot->twsk_slab == NULL)
2734 				goto out_free_timewait_sock_slab_name;
2735 		}
2736 	}
2737 
2738 	mutex_lock(&proto_list_mutex);
2739 	list_add(&prot->node, &proto_list);
2740 	assign_proto_idx(prot);
2741 	mutex_unlock(&proto_list_mutex);
2742 	return 0;
2743 
2744 out_free_timewait_sock_slab_name:
2745 	kfree(prot->twsk_prot->twsk_slab_name);
2746 out_free_request_sock_slab:
2747 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2748 		kmem_cache_destroy(prot->rsk_prot->slab);
2749 		prot->rsk_prot->slab = NULL;
2750 	}
2751 out_free_request_sock_slab_name:
2752 	if (prot->rsk_prot)
2753 		kfree(prot->rsk_prot->slab_name);
2754 out_free_sock_slab:
2755 	kmem_cache_destroy(prot->slab);
2756 	prot->slab = NULL;
2757 out:
2758 	return -ENOBUFS;
2759 }
2760 EXPORT_SYMBOL(proto_register);
2761 
2762 void proto_unregister(struct proto *prot)
2763 {
2764 	mutex_lock(&proto_list_mutex);
2765 	release_proto_idx(prot);
2766 	list_del(&prot->node);
2767 	mutex_unlock(&proto_list_mutex);
2768 
2769 	if (prot->slab != NULL) {
2770 		kmem_cache_destroy(prot->slab);
2771 		prot->slab = NULL;
2772 	}
2773 
2774 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2775 		kmem_cache_destroy(prot->rsk_prot->slab);
2776 		kfree(prot->rsk_prot->slab_name);
2777 		prot->rsk_prot->slab = NULL;
2778 	}
2779 
2780 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2781 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2782 		kfree(prot->twsk_prot->twsk_slab_name);
2783 		prot->twsk_prot->twsk_slab = NULL;
2784 	}
2785 }
2786 EXPORT_SYMBOL(proto_unregister);
2787 
2788 #ifdef CONFIG_PROC_FS
2789 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2790 	__acquires(proto_list_mutex)
2791 {
2792 	mutex_lock(&proto_list_mutex);
2793 	return seq_list_start_head(&proto_list, *pos);
2794 }
2795 
2796 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2797 {
2798 	return seq_list_next(v, &proto_list, pos);
2799 }
2800 
2801 static void proto_seq_stop(struct seq_file *seq, void *v)
2802 	__releases(proto_list_mutex)
2803 {
2804 	mutex_unlock(&proto_list_mutex);
2805 }
2806 
2807 static char proto_method_implemented(const void *method)
2808 {
2809 	return method == NULL ? 'n' : 'y';
2810 }
2811 static long sock_prot_memory_allocated(struct proto *proto)
2812 {
2813 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2814 }
2815 
2816 static char *sock_prot_memory_pressure(struct proto *proto)
2817 {
2818 	return proto->memory_pressure != NULL ?
2819 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2820 }
2821 
2822 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2823 {
2824 
2825 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2826 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2827 		   proto->name,
2828 		   proto->obj_size,
2829 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2830 		   sock_prot_memory_allocated(proto),
2831 		   sock_prot_memory_pressure(proto),
2832 		   proto->max_header,
2833 		   proto->slab == NULL ? "no" : "yes",
2834 		   module_name(proto->owner),
2835 		   proto_method_implemented(proto->close),
2836 		   proto_method_implemented(proto->connect),
2837 		   proto_method_implemented(proto->disconnect),
2838 		   proto_method_implemented(proto->accept),
2839 		   proto_method_implemented(proto->ioctl),
2840 		   proto_method_implemented(proto->init),
2841 		   proto_method_implemented(proto->destroy),
2842 		   proto_method_implemented(proto->shutdown),
2843 		   proto_method_implemented(proto->setsockopt),
2844 		   proto_method_implemented(proto->getsockopt),
2845 		   proto_method_implemented(proto->sendmsg),
2846 		   proto_method_implemented(proto->recvmsg),
2847 		   proto_method_implemented(proto->sendpage),
2848 		   proto_method_implemented(proto->bind),
2849 		   proto_method_implemented(proto->backlog_rcv),
2850 		   proto_method_implemented(proto->hash),
2851 		   proto_method_implemented(proto->unhash),
2852 		   proto_method_implemented(proto->get_port),
2853 		   proto_method_implemented(proto->enter_memory_pressure));
2854 }
2855 
2856 static int proto_seq_show(struct seq_file *seq, void *v)
2857 {
2858 	if (v == &proto_list)
2859 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2860 			   "protocol",
2861 			   "size",
2862 			   "sockets",
2863 			   "memory",
2864 			   "press",
2865 			   "maxhdr",
2866 			   "slab",
2867 			   "module",
2868 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2869 	else
2870 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2871 	return 0;
2872 }
2873 
2874 static const struct seq_operations proto_seq_ops = {
2875 	.start  = proto_seq_start,
2876 	.next   = proto_seq_next,
2877 	.stop   = proto_seq_stop,
2878 	.show   = proto_seq_show,
2879 };
2880 
2881 static int proto_seq_open(struct inode *inode, struct file *file)
2882 {
2883 	return seq_open_net(inode, file, &proto_seq_ops,
2884 			    sizeof(struct seq_net_private));
2885 }
2886 
2887 static const struct file_operations proto_seq_fops = {
2888 	.owner		= THIS_MODULE,
2889 	.open		= proto_seq_open,
2890 	.read		= seq_read,
2891 	.llseek		= seq_lseek,
2892 	.release	= seq_release_net,
2893 };
2894 
2895 static __net_init int proto_init_net(struct net *net)
2896 {
2897 	if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
2898 		return -ENOMEM;
2899 
2900 	return 0;
2901 }
2902 
2903 static __net_exit void proto_exit_net(struct net *net)
2904 {
2905 	remove_proc_entry("protocols", net->proc_net);
2906 }
2907 
2908 
2909 static __net_initdata struct pernet_operations proto_net_ops = {
2910 	.init = proto_init_net,
2911 	.exit = proto_exit_net,
2912 };
2913 
2914 static int __init proto_init(void)
2915 {
2916 	return register_pernet_subsys(&proto_net_ops);
2917 }
2918 
2919 subsys_initcall(proto_init);
2920 
2921 #endif /* PROC_FS */
2922