xref: /linux/net/core/sock.c (revision 108fc82596e3b66b819df9d28c1ebbc9ab5de14c)
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/types.h>
97 #include <linux/socket.h>
98 #include <linux/in.h>
99 #include <linux/kernel.h>
100 #include <linux/module.h>
101 #include <linux/proc_fs.h>
102 #include <linux/seq_file.h>
103 #include <linux/sched.h>
104 #include <linux/timer.h>
105 #include <linux/string.h>
106 #include <linux/sockios.h>
107 #include <linux/net.h>
108 #include <linux/mm.h>
109 #include <linux/slab.h>
110 #include <linux/interrupt.h>
111 #include <linux/poll.h>
112 #include <linux/tcp.h>
113 #include <linux/init.h>
114 #include <linux/highmem.h>
115 #include <linux/user_namespace.h>
116 #include <linux/static_key.h>
117 #include <linux/memcontrol.h>
118 #include <linux/prefetch.h>
119 
120 #include <asm/uaccess.h>
121 
122 #include <linux/netdevice.h>
123 #include <net/protocol.h>
124 #include <linux/skbuff.h>
125 #include <net/net_namespace.h>
126 #include <net/request_sock.h>
127 #include <net/sock.h>
128 #include <linux/net_tstamp.h>
129 #include <net/xfrm.h>
130 #include <linux/ipsec.h>
131 #include <net/cls_cgroup.h>
132 #include <net/netprio_cgroup.h>
133 
134 #include <linux/filter.h>
135 
136 #include <trace/events/sock.h>
137 
138 #ifdef CONFIG_INET
139 #include <net/tcp.h>
140 #endif
141 
142 static DEFINE_MUTEX(proto_list_mutex);
143 static LIST_HEAD(proto_list);
144 
145 #ifdef CONFIG_MEMCG_KMEM
146 int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
147 {
148 	struct proto *proto;
149 	int ret = 0;
150 
151 	mutex_lock(&proto_list_mutex);
152 	list_for_each_entry(proto, &proto_list, node) {
153 		if (proto->init_cgroup) {
154 			ret = proto->init_cgroup(memcg, ss);
155 			if (ret)
156 				goto out;
157 		}
158 	}
159 
160 	mutex_unlock(&proto_list_mutex);
161 	return ret;
162 out:
163 	list_for_each_entry_continue_reverse(proto, &proto_list, node)
164 		if (proto->destroy_cgroup)
165 			proto->destroy_cgroup(memcg);
166 	mutex_unlock(&proto_list_mutex);
167 	return ret;
168 }
169 
170 void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
171 {
172 	struct proto *proto;
173 
174 	mutex_lock(&proto_list_mutex);
175 	list_for_each_entry_reverse(proto, &proto_list, node)
176 		if (proto->destroy_cgroup)
177 			proto->destroy_cgroup(memcg);
178 	mutex_unlock(&proto_list_mutex);
179 }
180 #endif
181 
182 /*
183  * Each address family might have different locking rules, so we have
184  * one slock key per address family:
185  */
186 static struct lock_class_key af_family_keys[AF_MAX];
187 static struct lock_class_key af_family_slock_keys[AF_MAX];
188 
189 struct static_key memcg_socket_limit_enabled;
190 EXPORT_SYMBOL(memcg_socket_limit_enabled);
191 
192 /*
193  * Make lock validator output more readable. (we pre-construct these
194  * strings build-time, so that runtime initialization of socket
195  * locks is fast):
196  */
197 static const char *const af_family_key_strings[AF_MAX+1] = {
198   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
199   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
200   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
201   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
202   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
203   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
204   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
205   "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
206   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
207   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
208   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
209   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
210   "sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG"      ,
211   "sk_lock-AF_NFC"   , "sk_lock-AF_MAX"
212 };
213 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
214   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
215   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
216   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
217   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
218   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
219   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
220   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
221   "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
222   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
223   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
224   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
225   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
226   "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG"      ,
227   "slock-AF_NFC"   , "slock-AF_MAX"
228 };
229 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
230   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
231   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
232   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
233   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
234   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
235   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
236   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
237   "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
238   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
239   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
240   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
241   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
242   "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG"      ,
243   "clock-AF_NFC"   , "clock-AF_MAX"
244 };
245 
246 /*
247  * sk_callback_lock locking rules are per-address-family,
248  * so split the lock classes by using a per-AF key:
249  */
250 static struct lock_class_key af_callback_keys[AF_MAX];
251 
252 /* Take into consideration the size of the struct sk_buff overhead in the
253  * determination of these values, since that is non-constant across
254  * platforms.  This makes socket queueing behavior and performance
255  * not depend upon such differences.
256  */
257 #define _SK_MEM_PACKETS		256
258 #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
259 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
260 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
261 
262 /* Run time adjustable parameters. */
263 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
264 EXPORT_SYMBOL(sysctl_wmem_max);
265 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
266 EXPORT_SYMBOL(sysctl_rmem_max);
267 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
268 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
269 
270 /* Maximal space eaten by iovec or ancillary data plus some space */
271 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
272 EXPORT_SYMBOL(sysctl_optmem_max);
273 
274 struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
275 EXPORT_SYMBOL_GPL(memalloc_socks);
276 
277 /**
278  * sk_set_memalloc - sets %SOCK_MEMALLOC
279  * @sk: socket to set it on
280  *
281  * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
282  * It's the responsibility of the admin to adjust min_free_kbytes
283  * to meet the requirements
284  */
285 void sk_set_memalloc(struct sock *sk)
286 {
287 	sock_set_flag(sk, SOCK_MEMALLOC);
288 	sk->sk_allocation |= __GFP_MEMALLOC;
289 	static_key_slow_inc(&memalloc_socks);
290 }
291 EXPORT_SYMBOL_GPL(sk_set_memalloc);
292 
293 void sk_clear_memalloc(struct sock *sk)
294 {
295 	sock_reset_flag(sk, SOCK_MEMALLOC);
296 	sk->sk_allocation &= ~__GFP_MEMALLOC;
297 	static_key_slow_dec(&memalloc_socks);
298 
299 	/*
300 	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
301 	 * progress of swapping. However, if SOCK_MEMALLOC is cleared while
302 	 * it has rmem allocations there is a risk that the user of the
303 	 * socket cannot make forward progress due to exceeding the rmem
304 	 * limits. By rights, sk_clear_memalloc() should only be called
305 	 * on sockets being torn down but warn and reset the accounting if
306 	 * that assumption breaks.
307 	 */
308 	if (WARN_ON(sk->sk_forward_alloc))
309 		sk_mem_reclaim(sk);
310 }
311 EXPORT_SYMBOL_GPL(sk_clear_memalloc);
312 
313 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
314 {
315 	int ret;
316 	unsigned long pflags = current->flags;
317 
318 	/* these should have been dropped before queueing */
319 	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
320 
321 	current->flags |= PF_MEMALLOC;
322 	ret = sk->sk_backlog_rcv(sk, skb);
323 	tsk_restore_flags(current, pflags, PF_MEMALLOC);
324 
325 	return ret;
326 }
327 EXPORT_SYMBOL(__sk_backlog_rcv);
328 
329 #if defined(CONFIG_CGROUPS)
330 #if !defined(CONFIG_NET_CLS_CGROUP)
331 int net_cls_subsys_id = -1;
332 EXPORT_SYMBOL_GPL(net_cls_subsys_id);
333 #endif
334 #if !defined(CONFIG_NETPRIO_CGROUP)
335 int net_prio_subsys_id = -1;
336 EXPORT_SYMBOL_GPL(net_prio_subsys_id);
337 #endif
338 #endif
339 
340 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
341 {
342 	struct timeval tv;
343 
344 	if (optlen < sizeof(tv))
345 		return -EINVAL;
346 	if (copy_from_user(&tv, optval, sizeof(tv)))
347 		return -EFAULT;
348 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
349 		return -EDOM;
350 
351 	if (tv.tv_sec < 0) {
352 		static int warned __read_mostly;
353 
354 		*timeo_p = 0;
355 		if (warned < 10 && net_ratelimit()) {
356 			warned++;
357 			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
358 				__func__, current->comm, task_pid_nr(current));
359 		}
360 		return 0;
361 	}
362 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
363 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
364 		return 0;
365 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
366 		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
367 	return 0;
368 }
369 
370 static void sock_warn_obsolete_bsdism(const char *name)
371 {
372 	static int warned;
373 	static char warncomm[TASK_COMM_LEN];
374 	if (strcmp(warncomm, current->comm) && warned < 5) {
375 		strcpy(warncomm,  current->comm);
376 		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
377 			warncomm, name);
378 		warned++;
379 	}
380 }
381 
382 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
383 
384 static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
385 {
386 	if (sk->sk_flags & flags) {
387 		sk->sk_flags &= ~flags;
388 		if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
389 			net_disable_timestamp();
390 	}
391 }
392 
393 
394 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
395 {
396 	int err;
397 	int skb_len;
398 	unsigned long flags;
399 	struct sk_buff_head *list = &sk->sk_receive_queue;
400 
401 	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
402 		atomic_inc(&sk->sk_drops);
403 		trace_sock_rcvqueue_full(sk, skb);
404 		return -ENOMEM;
405 	}
406 
407 	err = sk_filter(sk, skb);
408 	if (err)
409 		return err;
410 
411 	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
412 		atomic_inc(&sk->sk_drops);
413 		return -ENOBUFS;
414 	}
415 
416 	skb->dev = NULL;
417 	skb_set_owner_r(skb, sk);
418 
419 	/* Cache the SKB length before we tack it onto the receive
420 	 * queue.  Once it is added it no longer belongs to us and
421 	 * may be freed by other threads of control pulling packets
422 	 * from the queue.
423 	 */
424 	skb_len = skb->len;
425 
426 	/* we escape from rcu protected region, make sure we dont leak
427 	 * a norefcounted dst
428 	 */
429 	skb_dst_force(skb);
430 
431 	spin_lock_irqsave(&list->lock, flags);
432 	skb->dropcount = atomic_read(&sk->sk_drops);
433 	__skb_queue_tail(list, skb);
434 	spin_unlock_irqrestore(&list->lock, flags);
435 
436 	if (!sock_flag(sk, SOCK_DEAD))
437 		sk->sk_data_ready(sk, skb_len);
438 	return 0;
439 }
440 EXPORT_SYMBOL(sock_queue_rcv_skb);
441 
442 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
443 {
444 	int rc = NET_RX_SUCCESS;
445 
446 	if (sk_filter(sk, skb))
447 		goto discard_and_relse;
448 
449 	skb->dev = NULL;
450 
451 	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) {
452 		atomic_inc(&sk->sk_drops);
453 		goto discard_and_relse;
454 	}
455 	if (nested)
456 		bh_lock_sock_nested(sk);
457 	else
458 		bh_lock_sock(sk);
459 	if (!sock_owned_by_user(sk)) {
460 		/*
461 		 * trylock + unlock semantics:
462 		 */
463 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
464 
465 		rc = sk_backlog_rcv(sk, skb);
466 
467 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
468 	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
469 		bh_unlock_sock(sk);
470 		atomic_inc(&sk->sk_drops);
471 		goto discard_and_relse;
472 	}
473 
474 	bh_unlock_sock(sk);
475 out:
476 	sock_put(sk);
477 	return rc;
478 discard_and_relse:
479 	kfree_skb(skb);
480 	goto out;
481 }
482 EXPORT_SYMBOL(sk_receive_skb);
483 
484 void sk_reset_txq(struct sock *sk)
485 {
486 	sk_tx_queue_clear(sk);
487 }
488 EXPORT_SYMBOL(sk_reset_txq);
489 
490 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
491 {
492 	struct dst_entry *dst = __sk_dst_get(sk);
493 
494 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
495 		sk_tx_queue_clear(sk);
496 		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
497 		dst_release(dst);
498 		return NULL;
499 	}
500 
501 	return dst;
502 }
503 EXPORT_SYMBOL(__sk_dst_check);
504 
505 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
506 {
507 	struct dst_entry *dst = sk_dst_get(sk);
508 
509 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
510 		sk_dst_reset(sk);
511 		dst_release(dst);
512 		return NULL;
513 	}
514 
515 	return dst;
516 }
517 EXPORT_SYMBOL(sk_dst_check);
518 
519 static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
520 {
521 	int ret = -ENOPROTOOPT;
522 #ifdef CONFIG_NETDEVICES
523 	struct net *net = sock_net(sk);
524 	char devname[IFNAMSIZ];
525 	int index;
526 
527 	/* Sorry... */
528 	ret = -EPERM;
529 	if (!capable(CAP_NET_RAW))
530 		goto out;
531 
532 	ret = -EINVAL;
533 	if (optlen < 0)
534 		goto out;
535 
536 	/* Bind this socket to a particular device like "eth0",
537 	 * as specified in the passed interface name. If the
538 	 * name is "" or the option length is zero the socket
539 	 * is not bound.
540 	 */
541 	if (optlen > IFNAMSIZ - 1)
542 		optlen = IFNAMSIZ - 1;
543 	memset(devname, 0, sizeof(devname));
544 
545 	ret = -EFAULT;
546 	if (copy_from_user(devname, optval, optlen))
547 		goto out;
548 
549 	index = 0;
550 	if (devname[0] != '\0') {
551 		struct net_device *dev;
552 
553 		rcu_read_lock();
554 		dev = dev_get_by_name_rcu(net, devname);
555 		if (dev)
556 			index = dev->ifindex;
557 		rcu_read_unlock();
558 		ret = -ENODEV;
559 		if (!dev)
560 			goto out;
561 	}
562 
563 	lock_sock(sk);
564 	sk->sk_bound_dev_if = index;
565 	sk_dst_reset(sk);
566 	release_sock(sk);
567 
568 	ret = 0;
569 
570 out:
571 #endif
572 
573 	return ret;
574 }
575 
576 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
577 {
578 	if (valbool)
579 		sock_set_flag(sk, bit);
580 	else
581 		sock_reset_flag(sk, bit);
582 }
583 
584 /*
585  *	This is meant for all protocols to use and covers goings on
586  *	at the socket level. Everything here is generic.
587  */
588 
589 int sock_setsockopt(struct socket *sock, int level, int optname,
590 		    char __user *optval, unsigned int optlen)
591 {
592 	struct sock *sk = sock->sk;
593 	int val;
594 	int valbool;
595 	struct linger ling;
596 	int ret = 0;
597 
598 	/*
599 	 *	Options without arguments
600 	 */
601 
602 	if (optname == SO_BINDTODEVICE)
603 		return sock_bindtodevice(sk, optval, optlen);
604 
605 	if (optlen < sizeof(int))
606 		return -EINVAL;
607 
608 	if (get_user(val, (int __user *)optval))
609 		return -EFAULT;
610 
611 	valbool = val ? 1 : 0;
612 
613 	lock_sock(sk);
614 
615 	switch (optname) {
616 	case SO_DEBUG:
617 		if (val && !capable(CAP_NET_ADMIN))
618 			ret = -EACCES;
619 		else
620 			sock_valbool_flag(sk, SOCK_DBG, valbool);
621 		break;
622 	case SO_REUSEADDR:
623 		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
624 		break;
625 	case SO_TYPE:
626 	case SO_PROTOCOL:
627 	case SO_DOMAIN:
628 	case SO_ERROR:
629 		ret = -ENOPROTOOPT;
630 		break;
631 	case SO_DONTROUTE:
632 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
633 		break;
634 	case SO_BROADCAST:
635 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
636 		break;
637 	case SO_SNDBUF:
638 		/* Don't error on this BSD doesn't and if you think
639 		 * about it this is right. Otherwise apps have to
640 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
641 		 * are treated in BSD as hints
642 		 */
643 		val = min_t(u32, val, sysctl_wmem_max);
644 set_sndbuf:
645 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
646 		sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
647 		/* Wake up sending tasks if we upped the value. */
648 		sk->sk_write_space(sk);
649 		break;
650 
651 	case SO_SNDBUFFORCE:
652 		if (!capable(CAP_NET_ADMIN)) {
653 			ret = -EPERM;
654 			break;
655 		}
656 		goto set_sndbuf;
657 
658 	case SO_RCVBUF:
659 		/* Don't error on this BSD doesn't and if you think
660 		 * about it this is right. Otherwise apps have to
661 		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
662 		 * are treated in BSD as hints
663 		 */
664 		val = min_t(u32, val, sysctl_rmem_max);
665 set_rcvbuf:
666 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
667 		/*
668 		 * We double it on the way in to account for
669 		 * "struct sk_buff" etc. overhead.   Applications
670 		 * assume that the SO_RCVBUF setting they make will
671 		 * allow that much actual data to be received on that
672 		 * socket.
673 		 *
674 		 * Applications are unaware that "struct sk_buff" and
675 		 * other overheads allocate from the receive buffer
676 		 * during socket buffer allocation.
677 		 *
678 		 * And after considering the possible alternatives,
679 		 * returning the value we actually used in getsockopt
680 		 * is the most desirable behavior.
681 		 */
682 		sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
683 		break;
684 
685 	case SO_RCVBUFFORCE:
686 		if (!capable(CAP_NET_ADMIN)) {
687 			ret = -EPERM;
688 			break;
689 		}
690 		goto set_rcvbuf;
691 
692 	case SO_KEEPALIVE:
693 #ifdef CONFIG_INET
694 		if (sk->sk_protocol == IPPROTO_TCP)
695 			tcp_set_keepalive(sk, valbool);
696 #endif
697 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
698 		break;
699 
700 	case SO_OOBINLINE:
701 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
702 		break;
703 
704 	case SO_NO_CHECK:
705 		sk->sk_no_check = valbool;
706 		break;
707 
708 	case SO_PRIORITY:
709 		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
710 			sk->sk_priority = val;
711 		else
712 			ret = -EPERM;
713 		break;
714 
715 	case SO_LINGER:
716 		if (optlen < sizeof(ling)) {
717 			ret = -EINVAL;	/* 1003.1g */
718 			break;
719 		}
720 		if (copy_from_user(&ling, optval, sizeof(ling))) {
721 			ret = -EFAULT;
722 			break;
723 		}
724 		if (!ling.l_onoff)
725 			sock_reset_flag(sk, SOCK_LINGER);
726 		else {
727 #if (BITS_PER_LONG == 32)
728 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
729 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
730 			else
731 #endif
732 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
733 			sock_set_flag(sk, SOCK_LINGER);
734 		}
735 		break;
736 
737 	case SO_BSDCOMPAT:
738 		sock_warn_obsolete_bsdism("setsockopt");
739 		break;
740 
741 	case SO_PASSCRED:
742 		if (valbool)
743 			set_bit(SOCK_PASSCRED, &sock->flags);
744 		else
745 			clear_bit(SOCK_PASSCRED, &sock->flags);
746 		break;
747 
748 	case SO_TIMESTAMP:
749 	case SO_TIMESTAMPNS:
750 		if (valbool)  {
751 			if (optname == SO_TIMESTAMP)
752 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
753 			else
754 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
755 			sock_set_flag(sk, SOCK_RCVTSTAMP);
756 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
757 		} else {
758 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
759 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
760 		}
761 		break;
762 
763 	case SO_TIMESTAMPING:
764 		if (val & ~SOF_TIMESTAMPING_MASK) {
765 			ret = -EINVAL;
766 			break;
767 		}
768 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
769 				  val & SOF_TIMESTAMPING_TX_HARDWARE);
770 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
771 				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
772 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
773 				  val & SOF_TIMESTAMPING_RX_HARDWARE);
774 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
775 			sock_enable_timestamp(sk,
776 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
777 		else
778 			sock_disable_timestamp(sk,
779 					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
780 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
781 				  val & SOF_TIMESTAMPING_SOFTWARE);
782 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
783 				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
784 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
785 				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
786 		break;
787 
788 	case SO_RCVLOWAT:
789 		if (val < 0)
790 			val = INT_MAX;
791 		sk->sk_rcvlowat = val ? : 1;
792 		break;
793 
794 	case SO_RCVTIMEO:
795 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
796 		break;
797 
798 	case SO_SNDTIMEO:
799 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
800 		break;
801 
802 	case SO_ATTACH_FILTER:
803 		ret = -EINVAL;
804 		if (optlen == sizeof(struct sock_fprog)) {
805 			struct sock_fprog fprog;
806 
807 			ret = -EFAULT;
808 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
809 				break;
810 
811 			ret = sk_attach_filter(&fprog, sk);
812 		}
813 		break;
814 
815 	case SO_DETACH_FILTER:
816 		ret = sk_detach_filter(sk);
817 		break;
818 
819 	case SO_PASSSEC:
820 		if (valbool)
821 			set_bit(SOCK_PASSSEC, &sock->flags);
822 		else
823 			clear_bit(SOCK_PASSSEC, &sock->flags);
824 		break;
825 	case SO_MARK:
826 		if (!capable(CAP_NET_ADMIN))
827 			ret = -EPERM;
828 		else
829 			sk->sk_mark = val;
830 		break;
831 
832 		/* We implement the SO_SNDLOWAT etc to
833 		   not be settable (1003.1g 5.3) */
834 	case SO_RXQ_OVFL:
835 		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
836 		break;
837 
838 	case SO_WIFI_STATUS:
839 		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
840 		break;
841 
842 	case SO_PEEK_OFF:
843 		if (sock->ops->set_peek_off)
844 			sock->ops->set_peek_off(sk, val);
845 		else
846 			ret = -EOPNOTSUPP;
847 		break;
848 
849 	case SO_NOFCS:
850 		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
851 		break;
852 
853 	default:
854 		ret = -ENOPROTOOPT;
855 		break;
856 	}
857 	release_sock(sk);
858 	return ret;
859 }
860 EXPORT_SYMBOL(sock_setsockopt);
861 
862 
863 void cred_to_ucred(struct pid *pid, const struct cred *cred,
864 		   struct ucred *ucred)
865 {
866 	ucred->pid = pid_vnr(pid);
867 	ucred->uid = ucred->gid = -1;
868 	if (cred) {
869 		struct user_namespace *current_ns = current_user_ns();
870 
871 		ucred->uid = from_kuid(current_ns, cred->euid);
872 		ucred->gid = from_kgid(current_ns, cred->egid);
873 	}
874 }
875 EXPORT_SYMBOL_GPL(cred_to_ucred);
876 
877 int sock_getsockopt(struct socket *sock, int level, int optname,
878 		    char __user *optval, int __user *optlen)
879 {
880 	struct sock *sk = sock->sk;
881 
882 	union {
883 		int val;
884 		struct linger ling;
885 		struct timeval tm;
886 	} v;
887 
888 	int lv = sizeof(int);
889 	int len;
890 
891 	if (get_user(len, optlen))
892 		return -EFAULT;
893 	if (len < 0)
894 		return -EINVAL;
895 
896 	memset(&v, 0, sizeof(v));
897 
898 	switch (optname) {
899 	case SO_DEBUG:
900 		v.val = sock_flag(sk, SOCK_DBG);
901 		break;
902 
903 	case SO_DONTROUTE:
904 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
905 		break;
906 
907 	case SO_BROADCAST:
908 		v.val = sock_flag(sk, SOCK_BROADCAST);
909 		break;
910 
911 	case SO_SNDBUF:
912 		v.val = sk->sk_sndbuf;
913 		break;
914 
915 	case SO_RCVBUF:
916 		v.val = sk->sk_rcvbuf;
917 		break;
918 
919 	case SO_REUSEADDR:
920 		v.val = sk->sk_reuse;
921 		break;
922 
923 	case SO_KEEPALIVE:
924 		v.val = sock_flag(sk, SOCK_KEEPOPEN);
925 		break;
926 
927 	case SO_TYPE:
928 		v.val = sk->sk_type;
929 		break;
930 
931 	case SO_PROTOCOL:
932 		v.val = sk->sk_protocol;
933 		break;
934 
935 	case SO_DOMAIN:
936 		v.val = sk->sk_family;
937 		break;
938 
939 	case SO_ERROR:
940 		v.val = -sock_error(sk);
941 		if (v.val == 0)
942 			v.val = xchg(&sk->sk_err_soft, 0);
943 		break;
944 
945 	case SO_OOBINLINE:
946 		v.val = sock_flag(sk, SOCK_URGINLINE);
947 		break;
948 
949 	case SO_NO_CHECK:
950 		v.val = sk->sk_no_check;
951 		break;
952 
953 	case SO_PRIORITY:
954 		v.val = sk->sk_priority;
955 		break;
956 
957 	case SO_LINGER:
958 		lv		= sizeof(v.ling);
959 		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
960 		v.ling.l_linger	= sk->sk_lingertime / HZ;
961 		break;
962 
963 	case SO_BSDCOMPAT:
964 		sock_warn_obsolete_bsdism("getsockopt");
965 		break;
966 
967 	case SO_TIMESTAMP:
968 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
969 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
970 		break;
971 
972 	case SO_TIMESTAMPNS:
973 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
974 		break;
975 
976 	case SO_TIMESTAMPING:
977 		v.val = 0;
978 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
979 			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
980 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
981 			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
982 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
983 			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
984 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
985 			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
986 		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
987 			v.val |= SOF_TIMESTAMPING_SOFTWARE;
988 		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
989 			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
990 		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
991 			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
992 		break;
993 
994 	case SO_RCVTIMEO:
995 		lv = sizeof(struct timeval);
996 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
997 			v.tm.tv_sec = 0;
998 			v.tm.tv_usec = 0;
999 		} else {
1000 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
1001 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
1002 		}
1003 		break;
1004 
1005 	case SO_SNDTIMEO:
1006 		lv = sizeof(struct timeval);
1007 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
1008 			v.tm.tv_sec = 0;
1009 			v.tm.tv_usec = 0;
1010 		} else {
1011 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
1012 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
1013 		}
1014 		break;
1015 
1016 	case SO_RCVLOWAT:
1017 		v.val = sk->sk_rcvlowat;
1018 		break;
1019 
1020 	case SO_SNDLOWAT:
1021 		v.val = 1;
1022 		break;
1023 
1024 	case SO_PASSCRED:
1025 		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
1026 		break;
1027 
1028 	case SO_PEERCRED:
1029 	{
1030 		struct ucred peercred;
1031 		if (len > sizeof(peercred))
1032 			len = sizeof(peercred);
1033 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
1034 		if (copy_to_user(optval, &peercred, len))
1035 			return -EFAULT;
1036 		goto lenout;
1037 	}
1038 
1039 	case SO_PEERNAME:
1040 	{
1041 		char address[128];
1042 
1043 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
1044 			return -ENOTCONN;
1045 		if (lv < len)
1046 			return -EINVAL;
1047 		if (copy_to_user(optval, address, len))
1048 			return -EFAULT;
1049 		goto lenout;
1050 	}
1051 
1052 	/* Dubious BSD thing... Probably nobody even uses it, but
1053 	 * the UNIX standard wants it for whatever reason... -DaveM
1054 	 */
1055 	case SO_ACCEPTCONN:
1056 		v.val = sk->sk_state == TCP_LISTEN;
1057 		break;
1058 
1059 	case SO_PASSSEC:
1060 		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
1061 		break;
1062 
1063 	case SO_PEERSEC:
1064 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
1065 
1066 	case SO_MARK:
1067 		v.val = sk->sk_mark;
1068 		break;
1069 
1070 	case SO_RXQ_OVFL:
1071 		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
1072 		break;
1073 
1074 	case SO_WIFI_STATUS:
1075 		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
1076 		break;
1077 
1078 	case SO_PEEK_OFF:
1079 		if (!sock->ops->set_peek_off)
1080 			return -EOPNOTSUPP;
1081 
1082 		v.val = sk->sk_peek_off;
1083 		break;
1084 	case SO_NOFCS:
1085 		v.val = sock_flag(sk, SOCK_NOFCS);
1086 		break;
1087 	default:
1088 		return -ENOPROTOOPT;
1089 	}
1090 
1091 	if (len > lv)
1092 		len = lv;
1093 	if (copy_to_user(optval, &v, len))
1094 		return -EFAULT;
1095 lenout:
1096 	if (put_user(len, optlen))
1097 		return -EFAULT;
1098 	return 0;
1099 }
1100 
1101 /*
1102  * Initialize an sk_lock.
1103  *
1104  * (We also register the sk_lock with the lock validator.)
1105  */
1106 static inline void sock_lock_init(struct sock *sk)
1107 {
1108 	sock_lock_init_class_and_name(sk,
1109 			af_family_slock_key_strings[sk->sk_family],
1110 			af_family_slock_keys + sk->sk_family,
1111 			af_family_key_strings[sk->sk_family],
1112 			af_family_keys + sk->sk_family);
1113 }
1114 
1115 /*
1116  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
1117  * even temporarly, because of RCU lookups. sk_node should also be left as is.
1118  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
1119  */
1120 static void sock_copy(struct sock *nsk, const struct sock *osk)
1121 {
1122 #ifdef CONFIG_SECURITY_NETWORK
1123 	void *sptr = nsk->sk_security;
1124 #endif
1125 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1126 
1127 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1128 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1129 
1130 #ifdef CONFIG_SECURITY_NETWORK
1131 	nsk->sk_security = sptr;
1132 	security_sk_clone(osk, nsk);
1133 #endif
1134 }
1135 
1136 /*
1137  * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
1138  * un-modified. Special care is taken when initializing object to zero.
1139  */
1140 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1141 {
1142 	if (offsetof(struct sock, sk_node.next) != 0)
1143 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1144 	memset(&sk->sk_node.pprev, 0,
1145 	       size - offsetof(struct sock, sk_node.pprev));
1146 }
1147 
1148 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1149 {
1150 	unsigned long nulls1, nulls2;
1151 
1152 	nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1153 	nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1154 	if (nulls1 > nulls2)
1155 		swap(nulls1, nulls2);
1156 
1157 	if (nulls1 != 0)
1158 		memset((char *)sk, 0, nulls1);
1159 	memset((char *)sk + nulls1 + sizeof(void *), 0,
1160 	       nulls2 - nulls1 - sizeof(void *));
1161 	memset((char *)sk + nulls2 + sizeof(void *), 0,
1162 	       size - nulls2 - sizeof(void *));
1163 }
1164 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1165 
1166 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1167 		int family)
1168 {
1169 	struct sock *sk;
1170 	struct kmem_cache *slab;
1171 
1172 	slab = prot->slab;
1173 	if (slab != NULL) {
1174 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1175 		if (!sk)
1176 			return sk;
1177 		if (priority & __GFP_ZERO) {
1178 			if (prot->clear_sk)
1179 				prot->clear_sk(sk, prot->obj_size);
1180 			else
1181 				sk_prot_clear_nulls(sk, prot->obj_size);
1182 		}
1183 	} else
1184 		sk = kmalloc(prot->obj_size, priority);
1185 
1186 	if (sk != NULL) {
1187 		kmemcheck_annotate_bitfield(sk, flags);
1188 
1189 		if (security_sk_alloc(sk, family, priority))
1190 			goto out_free;
1191 
1192 		if (!try_module_get(prot->owner))
1193 			goto out_free_sec;
1194 		sk_tx_queue_clear(sk);
1195 	}
1196 
1197 	return sk;
1198 
1199 out_free_sec:
1200 	security_sk_free(sk);
1201 out_free:
1202 	if (slab != NULL)
1203 		kmem_cache_free(slab, sk);
1204 	else
1205 		kfree(sk);
1206 	return NULL;
1207 }
1208 
1209 static void sk_prot_free(struct proto *prot, struct sock *sk)
1210 {
1211 	struct kmem_cache *slab;
1212 	struct module *owner;
1213 
1214 	owner = prot->owner;
1215 	slab = prot->slab;
1216 
1217 	security_sk_free(sk);
1218 	if (slab != NULL)
1219 		kmem_cache_free(slab, sk);
1220 	else
1221 		kfree(sk);
1222 	module_put(owner);
1223 }
1224 
1225 #ifdef CONFIG_CGROUPS
1226 void sock_update_classid(struct sock *sk)
1227 {
1228 	u32 classid;
1229 
1230 	rcu_read_lock();  /* doing current task, which cannot vanish. */
1231 	classid = task_cls_classid(current);
1232 	rcu_read_unlock();
1233 	if (classid && classid != sk->sk_classid)
1234 		sk->sk_classid = classid;
1235 }
1236 EXPORT_SYMBOL(sock_update_classid);
1237 
1238 void sock_update_netprioidx(struct sock *sk, struct task_struct *task)
1239 {
1240 	if (in_interrupt())
1241 		return;
1242 
1243 	sk->sk_cgrp_prioidx = task_netprioidx(task);
1244 }
1245 EXPORT_SYMBOL_GPL(sock_update_netprioidx);
1246 #endif
1247 
1248 /**
1249  *	sk_alloc - All socket objects are allocated here
1250  *	@net: the applicable net namespace
1251  *	@family: protocol family
1252  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1253  *	@prot: struct proto associated with this new sock instance
1254  */
1255 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1256 		      struct proto *prot)
1257 {
1258 	struct sock *sk;
1259 
1260 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1261 	if (sk) {
1262 		sk->sk_family = family;
1263 		/*
1264 		 * See comment in struct sock definition to understand
1265 		 * why we need sk_prot_creator -acme
1266 		 */
1267 		sk->sk_prot = sk->sk_prot_creator = prot;
1268 		sock_lock_init(sk);
1269 		sock_net_set(sk, get_net(net));
1270 		atomic_set(&sk->sk_wmem_alloc, 1);
1271 
1272 		sock_update_classid(sk);
1273 		sock_update_netprioidx(sk, current);
1274 	}
1275 
1276 	return sk;
1277 }
1278 EXPORT_SYMBOL(sk_alloc);
1279 
1280 static void __sk_free(struct sock *sk)
1281 {
1282 	struct sk_filter *filter;
1283 
1284 	if (sk->sk_destruct)
1285 		sk->sk_destruct(sk);
1286 
1287 	filter = rcu_dereference_check(sk->sk_filter,
1288 				       atomic_read(&sk->sk_wmem_alloc) == 0);
1289 	if (filter) {
1290 		sk_filter_uncharge(sk, filter);
1291 		RCU_INIT_POINTER(sk->sk_filter, NULL);
1292 	}
1293 
1294 	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
1295 
1296 	if (atomic_read(&sk->sk_omem_alloc))
1297 		pr_debug("%s: optmem leakage (%d bytes) detected\n",
1298 			 __func__, atomic_read(&sk->sk_omem_alloc));
1299 
1300 	if (sk->sk_peer_cred)
1301 		put_cred(sk->sk_peer_cred);
1302 	put_pid(sk->sk_peer_pid);
1303 	put_net(sock_net(sk));
1304 	sk_prot_free(sk->sk_prot_creator, sk);
1305 }
1306 
1307 void sk_free(struct sock *sk)
1308 {
1309 	/*
1310 	 * We subtract one from sk_wmem_alloc and can know if
1311 	 * some packets are still in some tx queue.
1312 	 * If not null, sock_wfree() will call __sk_free(sk) later
1313 	 */
1314 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1315 		__sk_free(sk);
1316 }
1317 EXPORT_SYMBOL(sk_free);
1318 
1319 /*
1320  * Last sock_put should drop reference to sk->sk_net. It has already
1321  * been dropped in sk_change_net. Taking reference to stopping namespace
1322  * is not an option.
1323  * Take reference to a socket to remove it from hash _alive_ and after that
1324  * destroy it in the context of init_net.
1325  */
1326 void sk_release_kernel(struct sock *sk)
1327 {
1328 	if (sk == NULL || sk->sk_socket == NULL)
1329 		return;
1330 
1331 	sock_hold(sk);
1332 	sock_release(sk->sk_socket);
1333 	release_net(sock_net(sk));
1334 	sock_net_set(sk, get_net(&init_net));
1335 	sock_put(sk);
1336 }
1337 EXPORT_SYMBOL(sk_release_kernel);
1338 
1339 static void sk_update_clone(const struct sock *sk, struct sock *newsk)
1340 {
1341 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
1342 		sock_update_memcg(newsk);
1343 }
1344 
1345 /**
1346  *	sk_clone_lock - clone a socket, and lock its clone
1347  *	@sk: the socket to clone
1348  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1349  *
1350  *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
1351  */
1352 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
1353 {
1354 	struct sock *newsk;
1355 
1356 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1357 	if (newsk != NULL) {
1358 		struct sk_filter *filter;
1359 
1360 		sock_copy(newsk, sk);
1361 
1362 		/* SANITY */
1363 		get_net(sock_net(newsk));
1364 		sk_node_init(&newsk->sk_node);
1365 		sock_lock_init(newsk);
1366 		bh_lock_sock(newsk);
1367 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1368 		newsk->sk_backlog.len = 0;
1369 
1370 		atomic_set(&newsk->sk_rmem_alloc, 0);
1371 		/*
1372 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1373 		 */
1374 		atomic_set(&newsk->sk_wmem_alloc, 1);
1375 		atomic_set(&newsk->sk_omem_alloc, 0);
1376 		skb_queue_head_init(&newsk->sk_receive_queue);
1377 		skb_queue_head_init(&newsk->sk_write_queue);
1378 #ifdef CONFIG_NET_DMA
1379 		skb_queue_head_init(&newsk->sk_async_wait_queue);
1380 #endif
1381 
1382 		spin_lock_init(&newsk->sk_dst_lock);
1383 		rwlock_init(&newsk->sk_callback_lock);
1384 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1385 				af_callback_keys + newsk->sk_family,
1386 				af_family_clock_key_strings[newsk->sk_family]);
1387 
1388 		newsk->sk_dst_cache	= NULL;
1389 		newsk->sk_wmem_queued	= 0;
1390 		newsk->sk_forward_alloc = 0;
1391 		newsk->sk_send_head	= NULL;
1392 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1393 
1394 		sock_reset_flag(newsk, SOCK_DONE);
1395 		skb_queue_head_init(&newsk->sk_error_queue);
1396 
1397 		filter = rcu_dereference_protected(newsk->sk_filter, 1);
1398 		if (filter != NULL)
1399 			sk_filter_charge(newsk, filter);
1400 
1401 		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1402 			/* It is still raw copy of parent, so invalidate
1403 			 * destructor and make plain sk_free() */
1404 			newsk->sk_destruct = NULL;
1405 			bh_unlock_sock(newsk);
1406 			sk_free(newsk);
1407 			newsk = NULL;
1408 			goto out;
1409 		}
1410 
1411 		newsk->sk_err	   = 0;
1412 		newsk->sk_priority = 0;
1413 		/*
1414 		 * Before updating sk_refcnt, we must commit prior changes to memory
1415 		 * (Documentation/RCU/rculist_nulls.txt for details)
1416 		 */
1417 		smp_wmb();
1418 		atomic_set(&newsk->sk_refcnt, 2);
1419 
1420 		/*
1421 		 * Increment the counter in the same struct proto as the master
1422 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1423 		 * is the same as sk->sk_prot->socks, as this field was copied
1424 		 * with memcpy).
1425 		 *
1426 		 * This _changes_ the previous behaviour, where
1427 		 * tcp_create_openreq_child always was incrementing the
1428 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1429 		 * to be taken into account in all callers. -acme
1430 		 */
1431 		sk_refcnt_debug_inc(newsk);
1432 		sk_set_socket(newsk, NULL);
1433 		newsk->sk_wq = NULL;
1434 
1435 		sk_update_clone(sk, newsk);
1436 
1437 		if (newsk->sk_prot->sockets_allocated)
1438 			sk_sockets_allocated_inc(newsk);
1439 
1440 		if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
1441 			net_enable_timestamp();
1442 	}
1443 out:
1444 	return newsk;
1445 }
1446 EXPORT_SYMBOL_GPL(sk_clone_lock);
1447 
1448 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1449 {
1450 	__sk_dst_set(sk, dst);
1451 	sk->sk_route_caps = dst->dev->features;
1452 	if (sk->sk_route_caps & NETIF_F_GSO)
1453 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1454 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1455 	if (sk_can_gso(sk)) {
1456 		if (dst->header_len) {
1457 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1458 		} else {
1459 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1460 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1461 			sk->sk_gso_max_segs = dst->dev->gso_max_segs;
1462 		}
1463 	}
1464 }
1465 EXPORT_SYMBOL_GPL(sk_setup_caps);
1466 
1467 void __init sk_init(void)
1468 {
1469 	if (totalram_pages <= 4096) {
1470 		sysctl_wmem_max = 32767;
1471 		sysctl_rmem_max = 32767;
1472 		sysctl_wmem_default = 32767;
1473 		sysctl_rmem_default = 32767;
1474 	} else if (totalram_pages >= 131072) {
1475 		sysctl_wmem_max = 131071;
1476 		sysctl_rmem_max = 131071;
1477 	}
1478 }
1479 
1480 /*
1481  *	Simple resource managers for sockets.
1482  */
1483 
1484 
1485 /*
1486  * Write buffer destructor automatically called from kfree_skb.
1487  */
1488 void sock_wfree(struct sk_buff *skb)
1489 {
1490 	struct sock *sk = skb->sk;
1491 	unsigned int len = skb->truesize;
1492 
1493 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1494 		/*
1495 		 * Keep a reference on sk_wmem_alloc, this will be released
1496 		 * after sk_write_space() call
1497 		 */
1498 		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1499 		sk->sk_write_space(sk);
1500 		len = 1;
1501 	}
1502 	/*
1503 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1504 	 * could not do because of in-flight packets
1505 	 */
1506 	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1507 		__sk_free(sk);
1508 }
1509 EXPORT_SYMBOL(sock_wfree);
1510 
1511 /*
1512  * Read buffer destructor automatically called from kfree_skb.
1513  */
1514 void sock_rfree(struct sk_buff *skb)
1515 {
1516 	struct sock *sk = skb->sk;
1517 	unsigned int len = skb->truesize;
1518 
1519 	atomic_sub(len, &sk->sk_rmem_alloc);
1520 	sk_mem_uncharge(sk, len);
1521 }
1522 EXPORT_SYMBOL(sock_rfree);
1523 
1524 void sock_edemux(struct sk_buff *skb)
1525 {
1526 	struct sock *sk = skb->sk;
1527 
1528 #ifdef CONFIG_INET
1529 	if (sk->sk_state == TCP_TIME_WAIT)
1530 		inet_twsk_put(inet_twsk(sk));
1531 	else
1532 #endif
1533 		sock_put(sk);
1534 }
1535 EXPORT_SYMBOL(sock_edemux);
1536 
1537 int sock_i_uid(struct sock *sk)
1538 {
1539 	int uid;
1540 
1541 	read_lock_bh(&sk->sk_callback_lock);
1542 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1543 	read_unlock_bh(&sk->sk_callback_lock);
1544 	return uid;
1545 }
1546 EXPORT_SYMBOL(sock_i_uid);
1547 
1548 unsigned long sock_i_ino(struct sock *sk)
1549 {
1550 	unsigned long ino;
1551 
1552 	read_lock_bh(&sk->sk_callback_lock);
1553 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1554 	read_unlock_bh(&sk->sk_callback_lock);
1555 	return ino;
1556 }
1557 EXPORT_SYMBOL(sock_i_ino);
1558 
1559 /*
1560  * Allocate a skb from the socket's send buffer.
1561  */
1562 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1563 			     gfp_t priority)
1564 {
1565 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1566 		struct sk_buff *skb = alloc_skb(size, priority);
1567 		if (skb) {
1568 			skb_set_owner_w(skb, sk);
1569 			return skb;
1570 		}
1571 	}
1572 	return NULL;
1573 }
1574 EXPORT_SYMBOL(sock_wmalloc);
1575 
1576 /*
1577  * Allocate a skb from the socket's receive buffer.
1578  */
1579 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1580 			     gfp_t priority)
1581 {
1582 	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1583 		struct sk_buff *skb = alloc_skb(size, priority);
1584 		if (skb) {
1585 			skb_set_owner_r(skb, sk);
1586 			return skb;
1587 		}
1588 	}
1589 	return NULL;
1590 }
1591 
1592 /*
1593  * Allocate a memory block from the socket's option memory buffer.
1594  */
1595 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1596 {
1597 	if ((unsigned int)size <= sysctl_optmem_max &&
1598 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1599 		void *mem;
1600 		/* First do the add, to avoid the race if kmalloc
1601 		 * might sleep.
1602 		 */
1603 		atomic_add(size, &sk->sk_omem_alloc);
1604 		mem = kmalloc(size, priority);
1605 		if (mem)
1606 			return mem;
1607 		atomic_sub(size, &sk->sk_omem_alloc);
1608 	}
1609 	return NULL;
1610 }
1611 EXPORT_SYMBOL(sock_kmalloc);
1612 
1613 /*
1614  * Free an option memory block.
1615  */
1616 void sock_kfree_s(struct sock *sk, void *mem, int size)
1617 {
1618 	kfree(mem);
1619 	atomic_sub(size, &sk->sk_omem_alloc);
1620 }
1621 EXPORT_SYMBOL(sock_kfree_s);
1622 
1623 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1624    I think, these locks should be removed for datagram sockets.
1625  */
1626 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1627 {
1628 	DEFINE_WAIT(wait);
1629 
1630 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1631 	for (;;) {
1632 		if (!timeo)
1633 			break;
1634 		if (signal_pending(current))
1635 			break;
1636 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1637 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1638 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1639 			break;
1640 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1641 			break;
1642 		if (sk->sk_err)
1643 			break;
1644 		timeo = schedule_timeout(timeo);
1645 	}
1646 	finish_wait(sk_sleep(sk), &wait);
1647 	return timeo;
1648 }
1649 
1650 
1651 /*
1652  *	Generic send/receive buffer handlers
1653  */
1654 
1655 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1656 				     unsigned long data_len, int noblock,
1657 				     int *errcode)
1658 {
1659 	struct sk_buff *skb;
1660 	gfp_t gfp_mask;
1661 	long timeo;
1662 	int err;
1663 	int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1664 
1665 	err = -EMSGSIZE;
1666 	if (npages > MAX_SKB_FRAGS)
1667 		goto failure;
1668 
1669 	gfp_mask = sk->sk_allocation;
1670 	if (gfp_mask & __GFP_WAIT)
1671 		gfp_mask |= __GFP_REPEAT;
1672 
1673 	timeo = sock_sndtimeo(sk, noblock);
1674 	while (1) {
1675 		err = sock_error(sk);
1676 		if (err != 0)
1677 			goto failure;
1678 
1679 		err = -EPIPE;
1680 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1681 			goto failure;
1682 
1683 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1684 			skb = alloc_skb(header_len, gfp_mask);
1685 			if (skb) {
1686 				int i;
1687 
1688 				/* No pages, we're done... */
1689 				if (!data_len)
1690 					break;
1691 
1692 				skb->truesize += data_len;
1693 				skb_shinfo(skb)->nr_frags = npages;
1694 				for (i = 0; i < npages; i++) {
1695 					struct page *page;
1696 
1697 					page = alloc_pages(sk->sk_allocation, 0);
1698 					if (!page) {
1699 						err = -ENOBUFS;
1700 						skb_shinfo(skb)->nr_frags = i;
1701 						kfree_skb(skb);
1702 						goto failure;
1703 					}
1704 
1705 					__skb_fill_page_desc(skb, i,
1706 							page, 0,
1707 							(data_len >= PAGE_SIZE ?
1708 							 PAGE_SIZE :
1709 							 data_len));
1710 					data_len -= PAGE_SIZE;
1711 				}
1712 
1713 				/* Full success... */
1714 				break;
1715 			}
1716 			err = -ENOBUFS;
1717 			goto failure;
1718 		}
1719 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1720 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1721 		err = -EAGAIN;
1722 		if (!timeo)
1723 			goto failure;
1724 		if (signal_pending(current))
1725 			goto interrupted;
1726 		timeo = sock_wait_for_wmem(sk, timeo);
1727 	}
1728 
1729 	skb_set_owner_w(skb, sk);
1730 	return skb;
1731 
1732 interrupted:
1733 	err = sock_intr_errno(timeo);
1734 failure:
1735 	*errcode = err;
1736 	return NULL;
1737 }
1738 EXPORT_SYMBOL(sock_alloc_send_pskb);
1739 
1740 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1741 				    int noblock, int *errcode)
1742 {
1743 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1744 }
1745 EXPORT_SYMBOL(sock_alloc_send_skb);
1746 
1747 static void __lock_sock(struct sock *sk)
1748 	__releases(&sk->sk_lock.slock)
1749 	__acquires(&sk->sk_lock.slock)
1750 {
1751 	DEFINE_WAIT(wait);
1752 
1753 	for (;;) {
1754 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1755 					TASK_UNINTERRUPTIBLE);
1756 		spin_unlock_bh(&sk->sk_lock.slock);
1757 		schedule();
1758 		spin_lock_bh(&sk->sk_lock.slock);
1759 		if (!sock_owned_by_user(sk))
1760 			break;
1761 	}
1762 	finish_wait(&sk->sk_lock.wq, &wait);
1763 }
1764 
1765 static void __release_sock(struct sock *sk)
1766 	__releases(&sk->sk_lock.slock)
1767 	__acquires(&sk->sk_lock.slock)
1768 {
1769 	struct sk_buff *skb = sk->sk_backlog.head;
1770 
1771 	do {
1772 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1773 		bh_unlock_sock(sk);
1774 
1775 		do {
1776 			struct sk_buff *next = skb->next;
1777 
1778 			prefetch(next);
1779 			WARN_ON_ONCE(skb_dst_is_noref(skb));
1780 			skb->next = NULL;
1781 			sk_backlog_rcv(sk, skb);
1782 
1783 			/*
1784 			 * We are in process context here with softirqs
1785 			 * disabled, use cond_resched_softirq() to preempt.
1786 			 * This is safe to do because we've taken the backlog
1787 			 * queue private:
1788 			 */
1789 			cond_resched_softirq();
1790 
1791 			skb = next;
1792 		} while (skb != NULL);
1793 
1794 		bh_lock_sock(sk);
1795 	} while ((skb = sk->sk_backlog.head) != NULL);
1796 
1797 	/*
1798 	 * Doing the zeroing here guarantee we can not loop forever
1799 	 * while a wild producer attempts to flood us.
1800 	 */
1801 	sk->sk_backlog.len = 0;
1802 }
1803 
1804 /**
1805  * sk_wait_data - wait for data to arrive at sk_receive_queue
1806  * @sk:    sock to wait on
1807  * @timeo: for how long
1808  *
1809  * Now socket state including sk->sk_err is changed only under lock,
1810  * hence we may omit checks after joining wait queue.
1811  * We check receive queue before schedule() only as optimization;
1812  * it is very likely that release_sock() added new data.
1813  */
1814 int sk_wait_data(struct sock *sk, long *timeo)
1815 {
1816 	int rc;
1817 	DEFINE_WAIT(wait);
1818 
1819 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1820 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1821 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1822 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1823 	finish_wait(sk_sleep(sk), &wait);
1824 	return rc;
1825 }
1826 EXPORT_SYMBOL(sk_wait_data);
1827 
1828 /**
1829  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1830  *	@sk: socket
1831  *	@size: memory size to allocate
1832  *	@kind: allocation type
1833  *
1834  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1835  *	rmem allocation. This function assumes that protocols which have
1836  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1837  */
1838 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1839 {
1840 	struct proto *prot = sk->sk_prot;
1841 	int amt = sk_mem_pages(size);
1842 	long allocated;
1843 	int parent_status = UNDER_LIMIT;
1844 
1845 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1846 
1847 	allocated = sk_memory_allocated_add(sk, amt, &parent_status);
1848 
1849 	/* Under limit. */
1850 	if (parent_status == UNDER_LIMIT &&
1851 			allocated <= sk_prot_mem_limits(sk, 0)) {
1852 		sk_leave_memory_pressure(sk);
1853 		return 1;
1854 	}
1855 
1856 	/* Under pressure. (we or our parents) */
1857 	if ((parent_status > SOFT_LIMIT) ||
1858 			allocated > sk_prot_mem_limits(sk, 1))
1859 		sk_enter_memory_pressure(sk);
1860 
1861 	/* Over hard limit (we or our parents) */
1862 	if ((parent_status == OVER_LIMIT) ||
1863 			(allocated > sk_prot_mem_limits(sk, 2)))
1864 		goto suppress_allocation;
1865 
1866 	/* guarantee minimum buffer size under pressure */
1867 	if (kind == SK_MEM_RECV) {
1868 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1869 			return 1;
1870 
1871 	} else { /* SK_MEM_SEND */
1872 		if (sk->sk_type == SOCK_STREAM) {
1873 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1874 				return 1;
1875 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1876 			   prot->sysctl_wmem[0])
1877 				return 1;
1878 	}
1879 
1880 	if (sk_has_memory_pressure(sk)) {
1881 		int alloc;
1882 
1883 		if (!sk_under_memory_pressure(sk))
1884 			return 1;
1885 		alloc = sk_sockets_allocated_read_positive(sk);
1886 		if (sk_prot_mem_limits(sk, 2) > alloc *
1887 		    sk_mem_pages(sk->sk_wmem_queued +
1888 				 atomic_read(&sk->sk_rmem_alloc) +
1889 				 sk->sk_forward_alloc))
1890 			return 1;
1891 	}
1892 
1893 suppress_allocation:
1894 
1895 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1896 		sk_stream_moderate_sndbuf(sk);
1897 
1898 		/* Fail only if socket is _under_ its sndbuf.
1899 		 * In this case we cannot block, so that we have to fail.
1900 		 */
1901 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1902 			return 1;
1903 	}
1904 
1905 	trace_sock_exceed_buf_limit(sk, prot, allocated);
1906 
1907 	/* Alas. Undo changes. */
1908 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1909 
1910 	sk_memory_allocated_sub(sk, amt);
1911 
1912 	return 0;
1913 }
1914 EXPORT_SYMBOL(__sk_mem_schedule);
1915 
1916 /**
1917  *	__sk_reclaim - reclaim memory_allocated
1918  *	@sk: socket
1919  */
1920 void __sk_mem_reclaim(struct sock *sk)
1921 {
1922 	sk_memory_allocated_sub(sk,
1923 				sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
1924 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1925 
1926 	if (sk_under_memory_pressure(sk) &&
1927 	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
1928 		sk_leave_memory_pressure(sk);
1929 }
1930 EXPORT_SYMBOL(__sk_mem_reclaim);
1931 
1932 
1933 /*
1934  * Set of default routines for initialising struct proto_ops when
1935  * the protocol does not support a particular function. In certain
1936  * cases where it makes no sense for a protocol to have a "do nothing"
1937  * function, some default processing is provided.
1938  */
1939 
1940 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1941 {
1942 	return -EOPNOTSUPP;
1943 }
1944 EXPORT_SYMBOL(sock_no_bind);
1945 
1946 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1947 		    int len, int flags)
1948 {
1949 	return -EOPNOTSUPP;
1950 }
1951 EXPORT_SYMBOL(sock_no_connect);
1952 
1953 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1954 {
1955 	return -EOPNOTSUPP;
1956 }
1957 EXPORT_SYMBOL(sock_no_socketpair);
1958 
1959 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1960 {
1961 	return -EOPNOTSUPP;
1962 }
1963 EXPORT_SYMBOL(sock_no_accept);
1964 
1965 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1966 		    int *len, int peer)
1967 {
1968 	return -EOPNOTSUPP;
1969 }
1970 EXPORT_SYMBOL(sock_no_getname);
1971 
1972 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1973 {
1974 	return 0;
1975 }
1976 EXPORT_SYMBOL(sock_no_poll);
1977 
1978 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1979 {
1980 	return -EOPNOTSUPP;
1981 }
1982 EXPORT_SYMBOL(sock_no_ioctl);
1983 
1984 int sock_no_listen(struct socket *sock, int backlog)
1985 {
1986 	return -EOPNOTSUPP;
1987 }
1988 EXPORT_SYMBOL(sock_no_listen);
1989 
1990 int sock_no_shutdown(struct socket *sock, int how)
1991 {
1992 	return -EOPNOTSUPP;
1993 }
1994 EXPORT_SYMBOL(sock_no_shutdown);
1995 
1996 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1997 		    char __user *optval, unsigned int optlen)
1998 {
1999 	return -EOPNOTSUPP;
2000 }
2001 EXPORT_SYMBOL(sock_no_setsockopt);
2002 
2003 int sock_no_getsockopt(struct socket *sock, int level, int optname,
2004 		    char __user *optval, int __user *optlen)
2005 {
2006 	return -EOPNOTSUPP;
2007 }
2008 EXPORT_SYMBOL(sock_no_getsockopt);
2009 
2010 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2011 		    size_t len)
2012 {
2013 	return -EOPNOTSUPP;
2014 }
2015 EXPORT_SYMBOL(sock_no_sendmsg);
2016 
2017 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
2018 		    size_t len, int flags)
2019 {
2020 	return -EOPNOTSUPP;
2021 }
2022 EXPORT_SYMBOL(sock_no_recvmsg);
2023 
2024 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
2025 {
2026 	/* Mirror missing mmap method error code */
2027 	return -ENODEV;
2028 }
2029 EXPORT_SYMBOL(sock_no_mmap);
2030 
2031 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
2032 {
2033 	ssize_t res;
2034 	struct msghdr msg = {.msg_flags = flags};
2035 	struct kvec iov;
2036 	char *kaddr = kmap(page);
2037 	iov.iov_base = kaddr + offset;
2038 	iov.iov_len = size;
2039 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
2040 	kunmap(page);
2041 	return res;
2042 }
2043 EXPORT_SYMBOL(sock_no_sendpage);
2044 
2045 /*
2046  *	Default Socket Callbacks
2047  */
2048 
2049 static void sock_def_wakeup(struct sock *sk)
2050 {
2051 	struct socket_wq *wq;
2052 
2053 	rcu_read_lock();
2054 	wq = rcu_dereference(sk->sk_wq);
2055 	if (wq_has_sleeper(wq))
2056 		wake_up_interruptible_all(&wq->wait);
2057 	rcu_read_unlock();
2058 }
2059 
2060 static void sock_def_error_report(struct sock *sk)
2061 {
2062 	struct socket_wq *wq;
2063 
2064 	rcu_read_lock();
2065 	wq = rcu_dereference(sk->sk_wq);
2066 	if (wq_has_sleeper(wq))
2067 		wake_up_interruptible_poll(&wq->wait, POLLERR);
2068 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
2069 	rcu_read_unlock();
2070 }
2071 
2072 static void sock_def_readable(struct sock *sk, int len)
2073 {
2074 	struct socket_wq *wq;
2075 
2076 	rcu_read_lock();
2077 	wq = rcu_dereference(sk->sk_wq);
2078 	if (wq_has_sleeper(wq))
2079 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
2080 						POLLRDNORM | POLLRDBAND);
2081 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
2082 	rcu_read_unlock();
2083 }
2084 
2085 static void sock_def_write_space(struct sock *sk)
2086 {
2087 	struct socket_wq *wq;
2088 
2089 	rcu_read_lock();
2090 
2091 	/* Do not wake up a writer until he can make "significant"
2092 	 * progress.  --DaveM
2093 	 */
2094 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
2095 		wq = rcu_dereference(sk->sk_wq);
2096 		if (wq_has_sleeper(wq))
2097 			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
2098 						POLLWRNORM | POLLWRBAND);
2099 
2100 		/* Should agree with poll, otherwise some programs break */
2101 		if (sock_writeable(sk))
2102 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
2103 	}
2104 
2105 	rcu_read_unlock();
2106 }
2107 
2108 static void sock_def_destruct(struct sock *sk)
2109 {
2110 	kfree(sk->sk_protinfo);
2111 }
2112 
2113 void sk_send_sigurg(struct sock *sk)
2114 {
2115 	if (sk->sk_socket && sk->sk_socket->file)
2116 		if (send_sigurg(&sk->sk_socket->file->f_owner))
2117 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
2118 }
2119 EXPORT_SYMBOL(sk_send_sigurg);
2120 
2121 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
2122 		    unsigned long expires)
2123 {
2124 	if (!mod_timer(timer, expires))
2125 		sock_hold(sk);
2126 }
2127 EXPORT_SYMBOL(sk_reset_timer);
2128 
2129 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
2130 {
2131 	if (timer_pending(timer) && del_timer(timer))
2132 		__sock_put(sk);
2133 }
2134 EXPORT_SYMBOL(sk_stop_timer);
2135 
2136 void sock_init_data(struct socket *sock, struct sock *sk)
2137 {
2138 	skb_queue_head_init(&sk->sk_receive_queue);
2139 	skb_queue_head_init(&sk->sk_write_queue);
2140 	skb_queue_head_init(&sk->sk_error_queue);
2141 #ifdef CONFIG_NET_DMA
2142 	skb_queue_head_init(&sk->sk_async_wait_queue);
2143 #endif
2144 
2145 	sk->sk_send_head	=	NULL;
2146 
2147 	init_timer(&sk->sk_timer);
2148 
2149 	sk->sk_allocation	=	GFP_KERNEL;
2150 	sk->sk_rcvbuf		=	sysctl_rmem_default;
2151 	sk->sk_sndbuf		=	sysctl_wmem_default;
2152 	sk->sk_state		=	TCP_CLOSE;
2153 	sk_set_socket(sk, sock);
2154 
2155 	sock_set_flag(sk, SOCK_ZAPPED);
2156 
2157 	if (sock) {
2158 		sk->sk_type	=	sock->type;
2159 		sk->sk_wq	=	sock->wq;
2160 		sock->sk	=	sk;
2161 	} else
2162 		sk->sk_wq	=	NULL;
2163 
2164 	spin_lock_init(&sk->sk_dst_lock);
2165 	rwlock_init(&sk->sk_callback_lock);
2166 	lockdep_set_class_and_name(&sk->sk_callback_lock,
2167 			af_callback_keys + sk->sk_family,
2168 			af_family_clock_key_strings[sk->sk_family]);
2169 
2170 	sk->sk_state_change	=	sock_def_wakeup;
2171 	sk->sk_data_ready	=	sock_def_readable;
2172 	sk->sk_write_space	=	sock_def_write_space;
2173 	sk->sk_error_report	=	sock_def_error_report;
2174 	sk->sk_destruct		=	sock_def_destruct;
2175 
2176 	sk->sk_sndmsg_page	=	NULL;
2177 	sk->sk_sndmsg_off	=	0;
2178 	sk->sk_peek_off		=	-1;
2179 
2180 	sk->sk_peer_pid 	=	NULL;
2181 	sk->sk_peer_cred	=	NULL;
2182 	sk->sk_write_pending	=	0;
2183 	sk->sk_rcvlowat		=	1;
2184 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2185 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2186 
2187 	sk->sk_stamp = ktime_set(-1L, 0);
2188 
2189 	/*
2190 	 * Before updating sk_refcnt, we must commit prior changes to memory
2191 	 * (Documentation/RCU/rculist_nulls.txt for details)
2192 	 */
2193 	smp_wmb();
2194 	atomic_set(&sk->sk_refcnt, 1);
2195 	atomic_set(&sk->sk_drops, 0);
2196 }
2197 EXPORT_SYMBOL(sock_init_data);
2198 
2199 void lock_sock_nested(struct sock *sk, int subclass)
2200 {
2201 	might_sleep();
2202 	spin_lock_bh(&sk->sk_lock.slock);
2203 	if (sk->sk_lock.owned)
2204 		__lock_sock(sk);
2205 	sk->sk_lock.owned = 1;
2206 	spin_unlock(&sk->sk_lock.slock);
2207 	/*
2208 	 * The sk_lock has mutex_lock() semantics here:
2209 	 */
2210 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2211 	local_bh_enable();
2212 }
2213 EXPORT_SYMBOL(lock_sock_nested);
2214 
2215 void release_sock(struct sock *sk)
2216 {
2217 	/*
2218 	 * The sk_lock has mutex_unlock() semantics:
2219 	 */
2220 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2221 
2222 	spin_lock_bh(&sk->sk_lock.slock);
2223 	if (sk->sk_backlog.tail)
2224 		__release_sock(sk);
2225 
2226 	if (sk->sk_prot->release_cb)
2227 		sk->sk_prot->release_cb(sk);
2228 
2229 	sk->sk_lock.owned = 0;
2230 	if (waitqueue_active(&sk->sk_lock.wq))
2231 		wake_up(&sk->sk_lock.wq);
2232 	spin_unlock_bh(&sk->sk_lock.slock);
2233 }
2234 EXPORT_SYMBOL(release_sock);
2235 
2236 /**
2237  * lock_sock_fast - fast version of lock_sock
2238  * @sk: socket
2239  *
2240  * This version should be used for very small section, where process wont block
2241  * return false if fast path is taken
2242  *   sk_lock.slock locked, owned = 0, BH disabled
2243  * return true if slow path is taken
2244  *   sk_lock.slock unlocked, owned = 1, BH enabled
2245  */
2246 bool lock_sock_fast(struct sock *sk)
2247 {
2248 	might_sleep();
2249 	spin_lock_bh(&sk->sk_lock.slock);
2250 
2251 	if (!sk->sk_lock.owned)
2252 		/*
2253 		 * Note : We must disable BH
2254 		 */
2255 		return false;
2256 
2257 	__lock_sock(sk);
2258 	sk->sk_lock.owned = 1;
2259 	spin_unlock(&sk->sk_lock.slock);
2260 	/*
2261 	 * The sk_lock has mutex_lock() semantics here:
2262 	 */
2263 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2264 	local_bh_enable();
2265 	return true;
2266 }
2267 EXPORT_SYMBOL(lock_sock_fast);
2268 
2269 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2270 {
2271 	struct timeval tv;
2272 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2273 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2274 	tv = ktime_to_timeval(sk->sk_stamp);
2275 	if (tv.tv_sec == -1)
2276 		return -ENOENT;
2277 	if (tv.tv_sec == 0) {
2278 		sk->sk_stamp = ktime_get_real();
2279 		tv = ktime_to_timeval(sk->sk_stamp);
2280 	}
2281 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2282 }
2283 EXPORT_SYMBOL(sock_get_timestamp);
2284 
2285 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2286 {
2287 	struct timespec ts;
2288 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2289 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2290 	ts = ktime_to_timespec(sk->sk_stamp);
2291 	if (ts.tv_sec == -1)
2292 		return -ENOENT;
2293 	if (ts.tv_sec == 0) {
2294 		sk->sk_stamp = ktime_get_real();
2295 		ts = ktime_to_timespec(sk->sk_stamp);
2296 	}
2297 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2298 }
2299 EXPORT_SYMBOL(sock_get_timestampns);
2300 
2301 void sock_enable_timestamp(struct sock *sk, int flag)
2302 {
2303 	if (!sock_flag(sk, flag)) {
2304 		unsigned long previous_flags = sk->sk_flags;
2305 
2306 		sock_set_flag(sk, flag);
2307 		/*
2308 		 * we just set one of the two flags which require net
2309 		 * time stamping, but time stamping might have been on
2310 		 * already because of the other one
2311 		 */
2312 		if (!(previous_flags & SK_FLAGS_TIMESTAMP))
2313 			net_enable_timestamp();
2314 	}
2315 }
2316 
2317 /*
2318  *	Get a socket option on an socket.
2319  *
2320  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2321  *	asynchronous errors should be reported by getsockopt. We assume
2322  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2323  */
2324 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2325 			   char __user *optval, int __user *optlen)
2326 {
2327 	struct sock *sk = sock->sk;
2328 
2329 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2330 }
2331 EXPORT_SYMBOL(sock_common_getsockopt);
2332 
2333 #ifdef CONFIG_COMPAT
2334 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2335 				  char __user *optval, int __user *optlen)
2336 {
2337 	struct sock *sk = sock->sk;
2338 
2339 	if (sk->sk_prot->compat_getsockopt != NULL)
2340 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2341 						      optval, optlen);
2342 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2343 }
2344 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2345 #endif
2346 
2347 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2348 			struct msghdr *msg, size_t size, int flags)
2349 {
2350 	struct sock *sk = sock->sk;
2351 	int addr_len = 0;
2352 	int err;
2353 
2354 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2355 				   flags & ~MSG_DONTWAIT, &addr_len);
2356 	if (err >= 0)
2357 		msg->msg_namelen = addr_len;
2358 	return err;
2359 }
2360 EXPORT_SYMBOL(sock_common_recvmsg);
2361 
2362 /*
2363  *	Set socket options on an inet socket.
2364  */
2365 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2366 			   char __user *optval, unsigned int optlen)
2367 {
2368 	struct sock *sk = sock->sk;
2369 
2370 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2371 }
2372 EXPORT_SYMBOL(sock_common_setsockopt);
2373 
2374 #ifdef CONFIG_COMPAT
2375 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2376 				  char __user *optval, unsigned int optlen)
2377 {
2378 	struct sock *sk = sock->sk;
2379 
2380 	if (sk->sk_prot->compat_setsockopt != NULL)
2381 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2382 						      optval, optlen);
2383 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2384 }
2385 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2386 #endif
2387 
2388 void sk_common_release(struct sock *sk)
2389 {
2390 	if (sk->sk_prot->destroy)
2391 		sk->sk_prot->destroy(sk);
2392 
2393 	/*
2394 	 * Observation: when sock_common_release is called, processes have
2395 	 * no access to socket. But net still has.
2396 	 * Step one, detach it from networking:
2397 	 *
2398 	 * A. Remove from hash tables.
2399 	 */
2400 
2401 	sk->sk_prot->unhash(sk);
2402 
2403 	/*
2404 	 * In this point socket cannot receive new packets, but it is possible
2405 	 * that some packets are in flight because some CPU runs receiver and
2406 	 * did hash table lookup before we unhashed socket. They will achieve
2407 	 * receive queue and will be purged by socket destructor.
2408 	 *
2409 	 * Also we still have packets pending on receive queue and probably,
2410 	 * our own packets waiting in device queues. sock_destroy will drain
2411 	 * receive queue, but transmitted packets will delay socket destruction
2412 	 * until the last reference will be released.
2413 	 */
2414 
2415 	sock_orphan(sk);
2416 
2417 	xfrm_sk_free_policy(sk);
2418 
2419 	sk_refcnt_debug_release(sk);
2420 	sock_put(sk);
2421 }
2422 EXPORT_SYMBOL(sk_common_release);
2423 
2424 #ifdef CONFIG_PROC_FS
2425 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2426 struct prot_inuse {
2427 	int val[PROTO_INUSE_NR];
2428 };
2429 
2430 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2431 
2432 #ifdef CONFIG_NET_NS
2433 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2434 {
2435 	__this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2436 }
2437 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2438 
2439 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2440 {
2441 	int cpu, idx = prot->inuse_idx;
2442 	int res = 0;
2443 
2444 	for_each_possible_cpu(cpu)
2445 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2446 
2447 	return res >= 0 ? res : 0;
2448 }
2449 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2450 
2451 static int __net_init sock_inuse_init_net(struct net *net)
2452 {
2453 	net->core.inuse = alloc_percpu(struct prot_inuse);
2454 	return net->core.inuse ? 0 : -ENOMEM;
2455 }
2456 
2457 static void __net_exit sock_inuse_exit_net(struct net *net)
2458 {
2459 	free_percpu(net->core.inuse);
2460 }
2461 
2462 static struct pernet_operations net_inuse_ops = {
2463 	.init = sock_inuse_init_net,
2464 	.exit = sock_inuse_exit_net,
2465 };
2466 
2467 static __init int net_inuse_init(void)
2468 {
2469 	if (register_pernet_subsys(&net_inuse_ops))
2470 		panic("Cannot initialize net inuse counters");
2471 
2472 	return 0;
2473 }
2474 
2475 core_initcall(net_inuse_init);
2476 #else
2477 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2478 
2479 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2480 {
2481 	__this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2482 }
2483 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2484 
2485 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2486 {
2487 	int cpu, idx = prot->inuse_idx;
2488 	int res = 0;
2489 
2490 	for_each_possible_cpu(cpu)
2491 		res += per_cpu(prot_inuse, cpu).val[idx];
2492 
2493 	return res >= 0 ? res : 0;
2494 }
2495 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2496 #endif
2497 
2498 static void assign_proto_idx(struct proto *prot)
2499 {
2500 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2501 
2502 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2503 		pr_err("PROTO_INUSE_NR exhausted\n");
2504 		return;
2505 	}
2506 
2507 	set_bit(prot->inuse_idx, proto_inuse_idx);
2508 }
2509 
2510 static void release_proto_idx(struct proto *prot)
2511 {
2512 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2513 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2514 }
2515 #else
2516 static inline void assign_proto_idx(struct proto *prot)
2517 {
2518 }
2519 
2520 static inline void release_proto_idx(struct proto *prot)
2521 {
2522 }
2523 #endif
2524 
2525 int proto_register(struct proto *prot, int alloc_slab)
2526 {
2527 	if (alloc_slab) {
2528 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2529 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2530 					NULL);
2531 
2532 		if (prot->slab == NULL) {
2533 			pr_crit("%s: Can't create sock SLAB cache!\n",
2534 				prot->name);
2535 			goto out;
2536 		}
2537 
2538 		if (prot->rsk_prot != NULL) {
2539 			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2540 			if (prot->rsk_prot->slab_name == NULL)
2541 				goto out_free_sock_slab;
2542 
2543 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2544 								 prot->rsk_prot->obj_size, 0,
2545 								 SLAB_HWCACHE_ALIGN, NULL);
2546 
2547 			if (prot->rsk_prot->slab == NULL) {
2548 				pr_crit("%s: Can't create request sock SLAB cache!\n",
2549 					prot->name);
2550 				goto out_free_request_sock_slab_name;
2551 			}
2552 		}
2553 
2554 		if (prot->twsk_prot != NULL) {
2555 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2556 
2557 			if (prot->twsk_prot->twsk_slab_name == NULL)
2558 				goto out_free_request_sock_slab;
2559 
2560 			prot->twsk_prot->twsk_slab =
2561 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2562 						  prot->twsk_prot->twsk_obj_size,
2563 						  0,
2564 						  SLAB_HWCACHE_ALIGN |
2565 							prot->slab_flags,
2566 						  NULL);
2567 			if (prot->twsk_prot->twsk_slab == NULL)
2568 				goto out_free_timewait_sock_slab_name;
2569 		}
2570 	}
2571 
2572 	mutex_lock(&proto_list_mutex);
2573 	list_add(&prot->node, &proto_list);
2574 	assign_proto_idx(prot);
2575 	mutex_unlock(&proto_list_mutex);
2576 	return 0;
2577 
2578 out_free_timewait_sock_slab_name:
2579 	kfree(prot->twsk_prot->twsk_slab_name);
2580 out_free_request_sock_slab:
2581 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2582 		kmem_cache_destroy(prot->rsk_prot->slab);
2583 		prot->rsk_prot->slab = NULL;
2584 	}
2585 out_free_request_sock_slab_name:
2586 	if (prot->rsk_prot)
2587 		kfree(prot->rsk_prot->slab_name);
2588 out_free_sock_slab:
2589 	kmem_cache_destroy(prot->slab);
2590 	prot->slab = NULL;
2591 out:
2592 	return -ENOBUFS;
2593 }
2594 EXPORT_SYMBOL(proto_register);
2595 
2596 void proto_unregister(struct proto *prot)
2597 {
2598 	mutex_lock(&proto_list_mutex);
2599 	release_proto_idx(prot);
2600 	list_del(&prot->node);
2601 	mutex_unlock(&proto_list_mutex);
2602 
2603 	if (prot->slab != NULL) {
2604 		kmem_cache_destroy(prot->slab);
2605 		prot->slab = NULL;
2606 	}
2607 
2608 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2609 		kmem_cache_destroy(prot->rsk_prot->slab);
2610 		kfree(prot->rsk_prot->slab_name);
2611 		prot->rsk_prot->slab = NULL;
2612 	}
2613 
2614 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2615 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2616 		kfree(prot->twsk_prot->twsk_slab_name);
2617 		prot->twsk_prot->twsk_slab = NULL;
2618 	}
2619 }
2620 EXPORT_SYMBOL(proto_unregister);
2621 
2622 #ifdef CONFIG_PROC_FS
2623 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2624 	__acquires(proto_list_mutex)
2625 {
2626 	mutex_lock(&proto_list_mutex);
2627 	return seq_list_start_head(&proto_list, *pos);
2628 }
2629 
2630 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2631 {
2632 	return seq_list_next(v, &proto_list, pos);
2633 }
2634 
2635 static void proto_seq_stop(struct seq_file *seq, void *v)
2636 	__releases(proto_list_mutex)
2637 {
2638 	mutex_unlock(&proto_list_mutex);
2639 }
2640 
2641 static char proto_method_implemented(const void *method)
2642 {
2643 	return method == NULL ? 'n' : 'y';
2644 }
2645 static long sock_prot_memory_allocated(struct proto *proto)
2646 {
2647 	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
2648 }
2649 
2650 static char *sock_prot_memory_pressure(struct proto *proto)
2651 {
2652 	return proto->memory_pressure != NULL ?
2653 	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
2654 }
2655 
2656 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2657 {
2658 
2659 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2660 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2661 		   proto->name,
2662 		   proto->obj_size,
2663 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2664 		   sock_prot_memory_allocated(proto),
2665 		   sock_prot_memory_pressure(proto),
2666 		   proto->max_header,
2667 		   proto->slab == NULL ? "no" : "yes",
2668 		   module_name(proto->owner),
2669 		   proto_method_implemented(proto->close),
2670 		   proto_method_implemented(proto->connect),
2671 		   proto_method_implemented(proto->disconnect),
2672 		   proto_method_implemented(proto->accept),
2673 		   proto_method_implemented(proto->ioctl),
2674 		   proto_method_implemented(proto->init),
2675 		   proto_method_implemented(proto->destroy),
2676 		   proto_method_implemented(proto->shutdown),
2677 		   proto_method_implemented(proto->setsockopt),
2678 		   proto_method_implemented(proto->getsockopt),
2679 		   proto_method_implemented(proto->sendmsg),
2680 		   proto_method_implemented(proto->recvmsg),
2681 		   proto_method_implemented(proto->sendpage),
2682 		   proto_method_implemented(proto->bind),
2683 		   proto_method_implemented(proto->backlog_rcv),
2684 		   proto_method_implemented(proto->hash),
2685 		   proto_method_implemented(proto->unhash),
2686 		   proto_method_implemented(proto->get_port),
2687 		   proto_method_implemented(proto->enter_memory_pressure));
2688 }
2689 
2690 static int proto_seq_show(struct seq_file *seq, void *v)
2691 {
2692 	if (v == &proto_list)
2693 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2694 			   "protocol",
2695 			   "size",
2696 			   "sockets",
2697 			   "memory",
2698 			   "press",
2699 			   "maxhdr",
2700 			   "slab",
2701 			   "module",
2702 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2703 	else
2704 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2705 	return 0;
2706 }
2707 
2708 static const struct seq_operations proto_seq_ops = {
2709 	.start  = proto_seq_start,
2710 	.next   = proto_seq_next,
2711 	.stop   = proto_seq_stop,
2712 	.show   = proto_seq_show,
2713 };
2714 
2715 static int proto_seq_open(struct inode *inode, struct file *file)
2716 {
2717 	return seq_open_net(inode, file, &proto_seq_ops,
2718 			    sizeof(struct seq_net_private));
2719 }
2720 
2721 static const struct file_operations proto_seq_fops = {
2722 	.owner		= THIS_MODULE,
2723 	.open		= proto_seq_open,
2724 	.read		= seq_read,
2725 	.llseek		= seq_lseek,
2726 	.release	= seq_release_net,
2727 };
2728 
2729 static __net_init int proto_init_net(struct net *net)
2730 {
2731 	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2732 		return -ENOMEM;
2733 
2734 	return 0;
2735 }
2736 
2737 static __net_exit void proto_exit_net(struct net *net)
2738 {
2739 	proc_net_remove(net, "protocols");
2740 }
2741 
2742 
2743 static __net_initdata struct pernet_operations proto_net_ops = {
2744 	.init = proto_init_net,
2745 	.exit = proto_exit_net,
2746 };
2747 
2748 static int __init proto_init(void)
2749 {
2750 	return register_pernet_subsys(&proto_net_ops);
2751 }
2752 
2753 subsys_initcall(proto_init);
2754 
2755 #endif /* PROC_FS */
2756