xref: /linux/net/core/sock.c (revision 47902f3611b392209e2a412bf7ec02dca95e666d)
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 #include <linux/capability.h>
93 #include <linux/errno.h>
94 #include <linux/types.h>
95 #include <linux/socket.h>
96 #include <linux/in.h>
97 #include <linux/kernel.h>
98 #include <linux/module.h>
99 #include <linux/proc_fs.h>
100 #include <linux/seq_file.h>
101 #include <linux/sched.h>
102 #include <linux/timer.h>
103 #include <linux/string.h>
104 #include <linux/sockios.h>
105 #include <linux/net.h>
106 #include <linux/mm.h>
107 #include <linux/slab.h>
108 #include <linux/interrupt.h>
109 #include <linux/poll.h>
110 #include <linux/tcp.h>
111 #include <linux/init.h>
112 #include <linux/highmem.h>
113 
114 #include <asm/uaccess.h>
115 #include <asm/system.h>
116 
117 #include <linux/netdevice.h>
118 #include <net/protocol.h>
119 #include <linux/skbuff.h>
120 #include <net/net_namespace.h>
121 #include <net/request_sock.h>
122 #include <net/sock.h>
123 #include <linux/net_tstamp.h>
124 #include <net/xfrm.h>
125 #include <linux/ipsec.h>
126 
127 #include <linux/filter.h>
128 
129 #ifdef CONFIG_INET
130 #include <net/tcp.h>
131 #endif
132 
133 /*
134  * Each address family might have different locking rules, so we have
135  * one slock key per address family:
136  */
137 static struct lock_class_key af_family_keys[AF_MAX];
138 static struct lock_class_key af_family_slock_keys[AF_MAX];
139 
140 /*
141  * Make lock validator output more readable. (we pre-construct these
142  * strings build-time, so that runtime initialization of socket
143  * locks is fast):
144  */
145 static const char *const af_family_key_strings[AF_MAX+1] = {
146   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
147   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
148   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
149   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
150   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
151   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
152   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
153   "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
154   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
155   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
156   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
157   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
158   "sk_lock-AF_IEEE802154",
159   "sk_lock-AF_MAX"
160 };
161 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
162   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
163   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
164   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
165   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
166   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
167   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
168   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
169   "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
170   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
171   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
172   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
173   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
174   "slock-AF_IEEE802154",
175   "slock-AF_MAX"
176 };
177 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
178   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
179   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
180   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
181   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
182   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
183   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
184   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
185   "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
186   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
187   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
188   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
189   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
190   "clock-AF_IEEE802154",
191   "clock-AF_MAX"
192 };
193 
194 /*
195  * sk_callback_lock locking rules are per-address-family,
196  * so split the lock classes by using a per-AF key:
197  */
198 static struct lock_class_key af_callback_keys[AF_MAX];
199 
200 /* Take into consideration the size of the struct sk_buff overhead in the
201  * determination of these values, since that is non-constant across
202  * platforms.  This makes socket queueing behavior and performance
203  * not depend upon such differences.
204  */
205 #define _SK_MEM_PACKETS		256
206 #define _SK_MEM_OVERHEAD	(sizeof(struct sk_buff) + 256)
207 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
208 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
209 
210 /* Run time adjustable parameters. */
211 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
212 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
213 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
214 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
215 
216 /* Maximal space eaten by iovec or ancilliary data plus some space */
217 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
218 EXPORT_SYMBOL(sysctl_optmem_max);
219 
220 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
221 {
222 	struct timeval tv;
223 
224 	if (optlen < sizeof(tv))
225 		return -EINVAL;
226 	if (copy_from_user(&tv, optval, sizeof(tv)))
227 		return -EFAULT;
228 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
229 		return -EDOM;
230 
231 	if (tv.tv_sec < 0) {
232 		static int warned __read_mostly;
233 
234 		*timeo_p = 0;
235 		if (warned < 10 && net_ratelimit()) {
236 			warned++;
237 			printk(KERN_INFO "sock_set_timeout: `%s' (pid %d) "
238 			       "tries to set negative timeout\n",
239 				current->comm, task_pid_nr(current));
240 		}
241 		return 0;
242 	}
243 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
244 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
245 		return 0;
246 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
247 		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
248 	return 0;
249 }
250 
251 static void sock_warn_obsolete_bsdism(const char *name)
252 {
253 	static int warned;
254 	static char warncomm[TASK_COMM_LEN];
255 	if (strcmp(warncomm, current->comm) && warned < 5) {
256 		strcpy(warncomm,  current->comm);
257 		printk(KERN_WARNING "process `%s' is using obsolete "
258 		       "%s SO_BSDCOMPAT\n", warncomm, name);
259 		warned++;
260 	}
261 }
262 
263 static void sock_disable_timestamp(struct sock *sk, int flag)
264 {
265 	if (sock_flag(sk, flag)) {
266 		sock_reset_flag(sk, flag);
267 		if (!sock_flag(sk, SOCK_TIMESTAMP) &&
268 		    !sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE)) {
269 			net_disable_timestamp();
270 		}
271 	}
272 }
273 
274 
275 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
276 {
277 	int err;
278 	int skb_len;
279 	unsigned long flags;
280 	struct sk_buff_head *list = &sk->sk_receive_queue;
281 
282 	/* Cast sk->rcvbuf to unsigned... It's pointless, but reduces
283 	   number of warnings when compiling with -W --ANK
284 	 */
285 	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
286 	    (unsigned)sk->sk_rcvbuf) {
287 		atomic_inc(&sk->sk_drops);
288 		return -ENOMEM;
289 	}
290 
291 	err = sk_filter(sk, skb);
292 	if (err)
293 		return err;
294 
295 	if (!sk_rmem_schedule(sk, skb->truesize)) {
296 		atomic_inc(&sk->sk_drops);
297 		return -ENOBUFS;
298 	}
299 
300 	skb->dev = NULL;
301 	skb_set_owner_r(skb, sk);
302 
303 	/* Cache the SKB length before we tack it onto the receive
304 	 * queue.  Once it is added it no longer belongs to us and
305 	 * may be freed by other threads of control pulling packets
306 	 * from the queue.
307 	 */
308 	skb_len = skb->len;
309 
310 	spin_lock_irqsave(&list->lock, flags);
311 	skb->dropcount = atomic_read(&sk->sk_drops);
312 	__skb_queue_tail(list, skb);
313 	spin_unlock_irqrestore(&list->lock, flags);
314 
315 	if (!sock_flag(sk, SOCK_DEAD))
316 		sk->sk_data_ready(sk, skb_len);
317 	return 0;
318 }
319 EXPORT_SYMBOL(sock_queue_rcv_skb);
320 
321 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
322 {
323 	int rc = NET_RX_SUCCESS;
324 
325 	if (sk_filter(sk, skb))
326 		goto discard_and_relse;
327 
328 	skb->dev = NULL;
329 
330 	if (nested)
331 		bh_lock_sock_nested(sk);
332 	else
333 		bh_lock_sock(sk);
334 	if (!sock_owned_by_user(sk)) {
335 		/*
336 		 * trylock + unlock semantics:
337 		 */
338 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
339 
340 		rc = sk_backlog_rcv(sk, skb);
341 
342 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
343 	} else if (sk_add_backlog(sk, skb)) {
344 		bh_unlock_sock(sk);
345 		atomic_inc(&sk->sk_drops);
346 		goto discard_and_relse;
347 	}
348 
349 	bh_unlock_sock(sk);
350 out:
351 	sock_put(sk);
352 	return rc;
353 discard_and_relse:
354 	kfree_skb(skb);
355 	goto out;
356 }
357 EXPORT_SYMBOL(sk_receive_skb);
358 
359 void sk_reset_txq(struct sock *sk)
360 {
361 	sk_tx_queue_clear(sk);
362 }
363 EXPORT_SYMBOL(sk_reset_txq);
364 
365 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
366 {
367 	struct dst_entry *dst = sk->sk_dst_cache;
368 
369 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
370 		sk_tx_queue_clear(sk);
371 		sk->sk_dst_cache = NULL;
372 		dst_release(dst);
373 		return NULL;
374 	}
375 
376 	return dst;
377 }
378 EXPORT_SYMBOL(__sk_dst_check);
379 
380 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
381 {
382 	struct dst_entry *dst = sk_dst_get(sk);
383 
384 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
385 		sk_dst_reset(sk);
386 		dst_release(dst);
387 		return NULL;
388 	}
389 
390 	return dst;
391 }
392 EXPORT_SYMBOL(sk_dst_check);
393 
394 static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
395 {
396 	int ret = -ENOPROTOOPT;
397 #ifdef CONFIG_NETDEVICES
398 	struct net *net = sock_net(sk);
399 	char devname[IFNAMSIZ];
400 	int index;
401 
402 	/* Sorry... */
403 	ret = -EPERM;
404 	if (!capable(CAP_NET_RAW))
405 		goto out;
406 
407 	ret = -EINVAL;
408 	if (optlen < 0)
409 		goto out;
410 
411 	/* Bind this socket to a particular device like "eth0",
412 	 * as specified in the passed interface name. If the
413 	 * name is "" or the option length is zero the socket
414 	 * is not bound.
415 	 */
416 	if (optlen > IFNAMSIZ - 1)
417 		optlen = IFNAMSIZ - 1;
418 	memset(devname, 0, sizeof(devname));
419 
420 	ret = -EFAULT;
421 	if (copy_from_user(devname, optval, optlen))
422 		goto out;
423 
424 	index = 0;
425 	if (devname[0] != '\0') {
426 		struct net_device *dev;
427 
428 		rcu_read_lock();
429 		dev = dev_get_by_name_rcu(net, devname);
430 		if (dev)
431 			index = dev->ifindex;
432 		rcu_read_unlock();
433 		ret = -ENODEV;
434 		if (!dev)
435 			goto out;
436 	}
437 
438 	lock_sock(sk);
439 	sk->sk_bound_dev_if = index;
440 	sk_dst_reset(sk);
441 	release_sock(sk);
442 
443 	ret = 0;
444 
445 out:
446 #endif
447 
448 	return ret;
449 }
450 
451 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
452 {
453 	if (valbool)
454 		sock_set_flag(sk, bit);
455 	else
456 		sock_reset_flag(sk, bit);
457 }
458 
459 /*
460  *	This is meant for all protocols to use and covers goings on
461  *	at the socket level. Everything here is generic.
462  */
463 
464 int sock_setsockopt(struct socket *sock, int level, int optname,
465 		    char __user *optval, unsigned int optlen)
466 {
467 	struct sock *sk = sock->sk;
468 	int val;
469 	int valbool;
470 	struct linger ling;
471 	int ret = 0;
472 
473 	/*
474 	 *	Options without arguments
475 	 */
476 
477 	if (optname == SO_BINDTODEVICE)
478 		return sock_bindtodevice(sk, optval, optlen);
479 
480 	if (optlen < sizeof(int))
481 		return -EINVAL;
482 
483 	if (get_user(val, (int __user *)optval))
484 		return -EFAULT;
485 
486 	valbool = val ? 1 : 0;
487 
488 	lock_sock(sk);
489 
490 	switch (optname) {
491 	case SO_DEBUG:
492 		if (val && !capable(CAP_NET_ADMIN))
493 			ret = -EACCES;
494 		else
495 			sock_valbool_flag(sk, SOCK_DBG, valbool);
496 		break;
497 	case SO_REUSEADDR:
498 		sk->sk_reuse = valbool;
499 		break;
500 	case SO_TYPE:
501 	case SO_PROTOCOL:
502 	case SO_DOMAIN:
503 	case SO_ERROR:
504 		ret = -ENOPROTOOPT;
505 		break;
506 	case SO_DONTROUTE:
507 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
508 		break;
509 	case SO_BROADCAST:
510 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
511 		break;
512 	case SO_SNDBUF:
513 		/* Don't error on this BSD doesn't and if you think
514 		   about it this is right. Otherwise apps have to
515 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
516 		   are treated in BSD as hints */
517 
518 		if (val > sysctl_wmem_max)
519 			val = sysctl_wmem_max;
520 set_sndbuf:
521 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
522 		if ((val * 2) < SOCK_MIN_SNDBUF)
523 			sk->sk_sndbuf = SOCK_MIN_SNDBUF;
524 		else
525 			sk->sk_sndbuf = val * 2;
526 
527 		/*
528 		 *	Wake up sending tasks if we
529 		 *	upped the value.
530 		 */
531 		sk->sk_write_space(sk);
532 		break;
533 
534 	case SO_SNDBUFFORCE:
535 		if (!capable(CAP_NET_ADMIN)) {
536 			ret = -EPERM;
537 			break;
538 		}
539 		goto set_sndbuf;
540 
541 	case SO_RCVBUF:
542 		/* Don't error on this BSD doesn't and if you think
543 		   about it this is right. Otherwise apps have to
544 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
545 		   are treated in BSD as hints */
546 
547 		if (val > sysctl_rmem_max)
548 			val = sysctl_rmem_max;
549 set_rcvbuf:
550 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
551 		/*
552 		 * We double it on the way in to account for
553 		 * "struct sk_buff" etc. overhead.   Applications
554 		 * assume that the SO_RCVBUF setting they make will
555 		 * allow that much actual data to be received on that
556 		 * socket.
557 		 *
558 		 * Applications are unaware that "struct sk_buff" and
559 		 * other overheads allocate from the receive buffer
560 		 * during socket buffer allocation.
561 		 *
562 		 * And after considering the possible alternatives,
563 		 * returning the value we actually used in getsockopt
564 		 * is the most desirable behavior.
565 		 */
566 		if ((val * 2) < SOCK_MIN_RCVBUF)
567 			sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
568 		else
569 			sk->sk_rcvbuf = val * 2;
570 		break;
571 
572 	case SO_RCVBUFFORCE:
573 		if (!capable(CAP_NET_ADMIN)) {
574 			ret = -EPERM;
575 			break;
576 		}
577 		goto set_rcvbuf;
578 
579 	case SO_KEEPALIVE:
580 #ifdef CONFIG_INET
581 		if (sk->sk_protocol == IPPROTO_TCP)
582 			tcp_set_keepalive(sk, valbool);
583 #endif
584 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
585 		break;
586 
587 	case SO_OOBINLINE:
588 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
589 		break;
590 
591 	case SO_NO_CHECK:
592 		sk->sk_no_check = valbool;
593 		break;
594 
595 	case SO_PRIORITY:
596 		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
597 			sk->sk_priority = val;
598 		else
599 			ret = -EPERM;
600 		break;
601 
602 	case SO_LINGER:
603 		if (optlen < sizeof(ling)) {
604 			ret = -EINVAL;	/* 1003.1g */
605 			break;
606 		}
607 		if (copy_from_user(&ling, optval, sizeof(ling))) {
608 			ret = -EFAULT;
609 			break;
610 		}
611 		if (!ling.l_onoff)
612 			sock_reset_flag(sk, SOCK_LINGER);
613 		else {
614 #if (BITS_PER_LONG == 32)
615 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
616 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
617 			else
618 #endif
619 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
620 			sock_set_flag(sk, SOCK_LINGER);
621 		}
622 		break;
623 
624 	case SO_BSDCOMPAT:
625 		sock_warn_obsolete_bsdism("setsockopt");
626 		break;
627 
628 	case SO_PASSCRED:
629 		if (valbool)
630 			set_bit(SOCK_PASSCRED, &sock->flags);
631 		else
632 			clear_bit(SOCK_PASSCRED, &sock->flags);
633 		break;
634 
635 	case SO_TIMESTAMP:
636 	case SO_TIMESTAMPNS:
637 		if (valbool)  {
638 			if (optname == SO_TIMESTAMP)
639 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
640 			else
641 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
642 			sock_set_flag(sk, SOCK_RCVTSTAMP);
643 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
644 		} else {
645 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
646 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
647 		}
648 		break;
649 
650 	case SO_TIMESTAMPING:
651 		if (val & ~SOF_TIMESTAMPING_MASK) {
652 			ret = -EINVAL;
653 			break;
654 		}
655 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
656 				  val & SOF_TIMESTAMPING_TX_HARDWARE);
657 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
658 				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
659 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
660 				  val & SOF_TIMESTAMPING_RX_HARDWARE);
661 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
662 			sock_enable_timestamp(sk,
663 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
664 		else
665 			sock_disable_timestamp(sk,
666 					       SOCK_TIMESTAMPING_RX_SOFTWARE);
667 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
668 				  val & SOF_TIMESTAMPING_SOFTWARE);
669 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
670 				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
671 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
672 				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
673 		break;
674 
675 	case SO_RCVLOWAT:
676 		if (val < 0)
677 			val = INT_MAX;
678 		sk->sk_rcvlowat = val ? : 1;
679 		break;
680 
681 	case SO_RCVTIMEO:
682 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
683 		break;
684 
685 	case SO_SNDTIMEO:
686 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
687 		break;
688 
689 	case SO_ATTACH_FILTER:
690 		ret = -EINVAL;
691 		if (optlen == sizeof(struct sock_fprog)) {
692 			struct sock_fprog fprog;
693 
694 			ret = -EFAULT;
695 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
696 				break;
697 
698 			ret = sk_attach_filter(&fprog, sk);
699 		}
700 		break;
701 
702 	case SO_DETACH_FILTER:
703 		ret = sk_detach_filter(sk);
704 		break;
705 
706 	case SO_PASSSEC:
707 		if (valbool)
708 			set_bit(SOCK_PASSSEC, &sock->flags);
709 		else
710 			clear_bit(SOCK_PASSSEC, &sock->flags);
711 		break;
712 	case SO_MARK:
713 		if (!capable(CAP_NET_ADMIN))
714 			ret = -EPERM;
715 		else
716 			sk->sk_mark = val;
717 		break;
718 
719 		/* We implement the SO_SNDLOWAT etc to
720 		   not be settable (1003.1g 5.3) */
721 	case SO_RXQ_OVFL:
722 		if (valbool)
723 			sock_set_flag(sk, SOCK_RXQ_OVFL);
724 		else
725 			sock_reset_flag(sk, SOCK_RXQ_OVFL);
726 		break;
727 	default:
728 		ret = -ENOPROTOOPT;
729 		break;
730 	}
731 	release_sock(sk);
732 	return ret;
733 }
734 EXPORT_SYMBOL(sock_setsockopt);
735 
736 
737 int sock_getsockopt(struct socket *sock, int level, int optname,
738 		    char __user *optval, int __user *optlen)
739 {
740 	struct sock *sk = sock->sk;
741 
742 	union {
743 		int val;
744 		struct linger ling;
745 		struct timeval tm;
746 	} v;
747 
748 	int lv = sizeof(int);
749 	int len;
750 
751 	if (get_user(len, optlen))
752 		return -EFAULT;
753 	if (len < 0)
754 		return -EINVAL;
755 
756 	memset(&v, 0, sizeof(v));
757 
758 	switch (optname) {
759 	case SO_DEBUG:
760 		v.val = sock_flag(sk, SOCK_DBG);
761 		break;
762 
763 	case SO_DONTROUTE:
764 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
765 		break;
766 
767 	case SO_BROADCAST:
768 		v.val = !!sock_flag(sk, SOCK_BROADCAST);
769 		break;
770 
771 	case SO_SNDBUF:
772 		v.val = sk->sk_sndbuf;
773 		break;
774 
775 	case SO_RCVBUF:
776 		v.val = sk->sk_rcvbuf;
777 		break;
778 
779 	case SO_REUSEADDR:
780 		v.val = sk->sk_reuse;
781 		break;
782 
783 	case SO_KEEPALIVE:
784 		v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
785 		break;
786 
787 	case SO_TYPE:
788 		v.val = sk->sk_type;
789 		break;
790 
791 	case SO_PROTOCOL:
792 		v.val = sk->sk_protocol;
793 		break;
794 
795 	case SO_DOMAIN:
796 		v.val = sk->sk_family;
797 		break;
798 
799 	case SO_ERROR:
800 		v.val = -sock_error(sk);
801 		if (v.val == 0)
802 			v.val = xchg(&sk->sk_err_soft, 0);
803 		break;
804 
805 	case SO_OOBINLINE:
806 		v.val = !!sock_flag(sk, SOCK_URGINLINE);
807 		break;
808 
809 	case SO_NO_CHECK:
810 		v.val = sk->sk_no_check;
811 		break;
812 
813 	case SO_PRIORITY:
814 		v.val = sk->sk_priority;
815 		break;
816 
817 	case SO_LINGER:
818 		lv		= sizeof(v.ling);
819 		v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
820 		v.ling.l_linger	= sk->sk_lingertime / HZ;
821 		break;
822 
823 	case SO_BSDCOMPAT:
824 		sock_warn_obsolete_bsdism("getsockopt");
825 		break;
826 
827 	case SO_TIMESTAMP:
828 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
829 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
830 		break;
831 
832 	case SO_TIMESTAMPNS:
833 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
834 		break;
835 
836 	case SO_TIMESTAMPING:
837 		v.val = 0;
838 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
839 			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
840 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
841 			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
842 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
843 			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
844 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
845 			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
846 		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
847 			v.val |= SOF_TIMESTAMPING_SOFTWARE;
848 		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
849 			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
850 		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
851 			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
852 		break;
853 
854 	case SO_RCVTIMEO:
855 		lv = sizeof(struct timeval);
856 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
857 			v.tm.tv_sec = 0;
858 			v.tm.tv_usec = 0;
859 		} else {
860 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
861 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
862 		}
863 		break;
864 
865 	case SO_SNDTIMEO:
866 		lv = sizeof(struct timeval);
867 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
868 			v.tm.tv_sec = 0;
869 			v.tm.tv_usec = 0;
870 		} else {
871 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
872 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
873 		}
874 		break;
875 
876 	case SO_RCVLOWAT:
877 		v.val = sk->sk_rcvlowat;
878 		break;
879 
880 	case SO_SNDLOWAT:
881 		v.val = 1;
882 		break;
883 
884 	case SO_PASSCRED:
885 		v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
886 		break;
887 
888 	case SO_PEERCRED:
889 		if (len > sizeof(sk->sk_peercred))
890 			len = sizeof(sk->sk_peercred);
891 		if (copy_to_user(optval, &sk->sk_peercred, len))
892 			return -EFAULT;
893 		goto lenout;
894 
895 	case SO_PEERNAME:
896 	{
897 		char address[128];
898 
899 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
900 			return -ENOTCONN;
901 		if (lv < len)
902 			return -EINVAL;
903 		if (copy_to_user(optval, address, len))
904 			return -EFAULT;
905 		goto lenout;
906 	}
907 
908 	/* Dubious BSD thing... Probably nobody even uses it, but
909 	 * the UNIX standard wants it for whatever reason... -DaveM
910 	 */
911 	case SO_ACCEPTCONN:
912 		v.val = sk->sk_state == TCP_LISTEN;
913 		break;
914 
915 	case SO_PASSSEC:
916 		v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
917 		break;
918 
919 	case SO_PEERSEC:
920 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
921 
922 	case SO_MARK:
923 		v.val = sk->sk_mark;
924 		break;
925 
926 	case SO_RXQ_OVFL:
927 		v.val = !!sock_flag(sk, SOCK_RXQ_OVFL);
928 		break;
929 
930 	default:
931 		return -ENOPROTOOPT;
932 	}
933 
934 	if (len > lv)
935 		len = lv;
936 	if (copy_to_user(optval, &v, len))
937 		return -EFAULT;
938 lenout:
939 	if (put_user(len, optlen))
940 		return -EFAULT;
941 	return 0;
942 }
943 
944 /*
945  * Initialize an sk_lock.
946  *
947  * (We also register the sk_lock with the lock validator.)
948  */
949 static inline void sock_lock_init(struct sock *sk)
950 {
951 	sock_lock_init_class_and_name(sk,
952 			af_family_slock_key_strings[sk->sk_family],
953 			af_family_slock_keys + sk->sk_family,
954 			af_family_key_strings[sk->sk_family],
955 			af_family_keys + sk->sk_family);
956 }
957 
958 /*
959  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
960  * even temporarly, because of RCU lookups. sk_node should also be left as is.
961  */
962 static void sock_copy(struct sock *nsk, const struct sock *osk)
963 {
964 #ifdef CONFIG_SECURITY_NETWORK
965 	void *sptr = nsk->sk_security;
966 #endif
967 	BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) !=
968 		     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt) +
969 		     sizeof(osk->sk_tx_queue_mapping));
970 	memcpy(&nsk->sk_copy_start, &osk->sk_copy_start,
971 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start));
972 #ifdef CONFIG_SECURITY_NETWORK
973 	nsk->sk_security = sptr;
974 	security_sk_clone(osk, nsk);
975 #endif
976 }
977 
978 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
979 		int family)
980 {
981 	struct sock *sk;
982 	struct kmem_cache *slab;
983 
984 	slab = prot->slab;
985 	if (slab != NULL) {
986 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
987 		if (!sk)
988 			return sk;
989 		if (priority & __GFP_ZERO) {
990 			/*
991 			 * caches using SLAB_DESTROY_BY_RCU should let
992 			 * sk_node.next un-modified. Special care is taken
993 			 * when initializing object to zero.
994 			 */
995 			if (offsetof(struct sock, sk_node.next) != 0)
996 				memset(sk, 0, offsetof(struct sock, sk_node.next));
997 			memset(&sk->sk_node.pprev, 0,
998 			       prot->obj_size - offsetof(struct sock,
999 							 sk_node.pprev));
1000 		}
1001 	}
1002 	else
1003 		sk = kmalloc(prot->obj_size, priority);
1004 
1005 	if (sk != NULL) {
1006 		kmemcheck_annotate_bitfield(sk, flags);
1007 
1008 		if (security_sk_alloc(sk, family, priority))
1009 			goto out_free;
1010 
1011 		if (!try_module_get(prot->owner))
1012 			goto out_free_sec;
1013 		sk_tx_queue_clear(sk);
1014 	}
1015 
1016 	return sk;
1017 
1018 out_free_sec:
1019 	security_sk_free(sk);
1020 out_free:
1021 	if (slab != NULL)
1022 		kmem_cache_free(slab, sk);
1023 	else
1024 		kfree(sk);
1025 	return NULL;
1026 }
1027 
1028 static void sk_prot_free(struct proto *prot, struct sock *sk)
1029 {
1030 	struct kmem_cache *slab;
1031 	struct module *owner;
1032 
1033 	owner = prot->owner;
1034 	slab = prot->slab;
1035 
1036 	security_sk_free(sk);
1037 	if (slab != NULL)
1038 		kmem_cache_free(slab, sk);
1039 	else
1040 		kfree(sk);
1041 	module_put(owner);
1042 }
1043 
1044 /**
1045  *	sk_alloc - All socket objects are allocated here
1046  *	@net: the applicable net namespace
1047  *	@family: protocol family
1048  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1049  *	@prot: struct proto associated with this new sock instance
1050  */
1051 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1052 		      struct proto *prot)
1053 {
1054 	struct sock *sk;
1055 
1056 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1057 	if (sk) {
1058 		sk->sk_family = family;
1059 		/*
1060 		 * See comment in struct sock definition to understand
1061 		 * why we need sk_prot_creator -acme
1062 		 */
1063 		sk->sk_prot = sk->sk_prot_creator = prot;
1064 		sock_lock_init(sk);
1065 		sock_net_set(sk, get_net(net));
1066 		atomic_set(&sk->sk_wmem_alloc, 1);
1067 	}
1068 
1069 	return sk;
1070 }
1071 EXPORT_SYMBOL(sk_alloc);
1072 
1073 static void __sk_free(struct sock *sk)
1074 {
1075 	struct sk_filter *filter;
1076 
1077 	if (sk->sk_destruct)
1078 		sk->sk_destruct(sk);
1079 
1080 	filter = rcu_dereference_check(sk->sk_filter,
1081 				       atomic_read(&sk->sk_wmem_alloc) == 0);
1082 	if (filter) {
1083 		sk_filter_uncharge(sk, filter);
1084 		rcu_assign_pointer(sk->sk_filter, NULL);
1085 	}
1086 
1087 	sock_disable_timestamp(sk, SOCK_TIMESTAMP);
1088 	sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
1089 
1090 	if (atomic_read(&sk->sk_omem_alloc))
1091 		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
1092 		       __func__, atomic_read(&sk->sk_omem_alloc));
1093 
1094 	put_net(sock_net(sk));
1095 	sk_prot_free(sk->sk_prot_creator, sk);
1096 }
1097 
1098 void sk_free(struct sock *sk)
1099 {
1100 	/*
1101 	 * We substract one from sk_wmem_alloc and can know if
1102 	 * some packets are still in some tx queue.
1103 	 * If not null, sock_wfree() will call __sk_free(sk) later
1104 	 */
1105 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1106 		__sk_free(sk);
1107 }
1108 EXPORT_SYMBOL(sk_free);
1109 
1110 /*
1111  * Last sock_put should drop referrence to sk->sk_net. It has already
1112  * been dropped in sk_change_net. Taking referrence to stopping namespace
1113  * is not an option.
1114  * Take referrence to a socket to remove it from hash _alive_ and after that
1115  * destroy it in the context of init_net.
1116  */
1117 void sk_release_kernel(struct sock *sk)
1118 {
1119 	if (sk == NULL || sk->sk_socket == NULL)
1120 		return;
1121 
1122 	sock_hold(sk);
1123 	sock_release(sk->sk_socket);
1124 	release_net(sock_net(sk));
1125 	sock_net_set(sk, get_net(&init_net));
1126 	sock_put(sk);
1127 }
1128 EXPORT_SYMBOL(sk_release_kernel);
1129 
1130 struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1131 {
1132 	struct sock *newsk;
1133 
1134 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1135 	if (newsk != NULL) {
1136 		struct sk_filter *filter;
1137 
1138 		sock_copy(newsk, sk);
1139 
1140 		/* SANITY */
1141 		get_net(sock_net(newsk));
1142 		sk_node_init(&newsk->sk_node);
1143 		sock_lock_init(newsk);
1144 		bh_lock_sock(newsk);
1145 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1146 		newsk->sk_backlog.len = 0;
1147 
1148 		atomic_set(&newsk->sk_rmem_alloc, 0);
1149 		/*
1150 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1151 		 */
1152 		atomic_set(&newsk->sk_wmem_alloc, 1);
1153 		atomic_set(&newsk->sk_omem_alloc, 0);
1154 		skb_queue_head_init(&newsk->sk_receive_queue);
1155 		skb_queue_head_init(&newsk->sk_write_queue);
1156 #ifdef CONFIG_NET_DMA
1157 		skb_queue_head_init(&newsk->sk_async_wait_queue);
1158 #endif
1159 
1160 		rwlock_init(&newsk->sk_dst_lock);
1161 		rwlock_init(&newsk->sk_callback_lock);
1162 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1163 				af_callback_keys + newsk->sk_family,
1164 				af_family_clock_key_strings[newsk->sk_family]);
1165 
1166 		newsk->sk_dst_cache	= NULL;
1167 		newsk->sk_wmem_queued	= 0;
1168 		newsk->sk_forward_alloc = 0;
1169 		newsk->sk_send_head	= NULL;
1170 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1171 
1172 		sock_reset_flag(newsk, SOCK_DONE);
1173 		skb_queue_head_init(&newsk->sk_error_queue);
1174 
1175 		filter = newsk->sk_filter;
1176 		if (filter != NULL)
1177 			sk_filter_charge(newsk, filter);
1178 
1179 		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1180 			/* It is still raw copy of parent, so invalidate
1181 			 * destructor and make plain sk_free() */
1182 			newsk->sk_destruct = NULL;
1183 			sk_free(newsk);
1184 			newsk = NULL;
1185 			goto out;
1186 		}
1187 
1188 		newsk->sk_err	   = 0;
1189 		newsk->sk_priority = 0;
1190 		/*
1191 		 * Before updating sk_refcnt, we must commit prior changes to memory
1192 		 * (Documentation/RCU/rculist_nulls.txt for details)
1193 		 */
1194 		smp_wmb();
1195 		atomic_set(&newsk->sk_refcnt, 2);
1196 
1197 		/*
1198 		 * Increment the counter in the same struct proto as the master
1199 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1200 		 * is the same as sk->sk_prot->socks, as this field was copied
1201 		 * with memcpy).
1202 		 *
1203 		 * This _changes_ the previous behaviour, where
1204 		 * tcp_create_openreq_child always was incrementing the
1205 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1206 		 * to be taken into account in all callers. -acme
1207 		 */
1208 		sk_refcnt_debug_inc(newsk);
1209 		sk_set_socket(newsk, NULL);
1210 		newsk->sk_sleep	 = NULL;
1211 
1212 		if (newsk->sk_prot->sockets_allocated)
1213 			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1214 
1215 		if (sock_flag(newsk, SOCK_TIMESTAMP) ||
1216 		    sock_flag(newsk, SOCK_TIMESTAMPING_RX_SOFTWARE))
1217 			net_enable_timestamp();
1218 	}
1219 out:
1220 	return newsk;
1221 }
1222 EXPORT_SYMBOL_GPL(sk_clone);
1223 
1224 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1225 {
1226 	__sk_dst_set(sk, dst);
1227 	sk->sk_route_caps = dst->dev->features;
1228 	if (sk->sk_route_caps & NETIF_F_GSO)
1229 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1230 	if (sk_can_gso(sk)) {
1231 		if (dst->header_len) {
1232 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1233 		} else {
1234 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1235 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1236 		}
1237 	}
1238 }
1239 EXPORT_SYMBOL_GPL(sk_setup_caps);
1240 
1241 void __init sk_init(void)
1242 {
1243 	if (totalram_pages <= 4096) {
1244 		sysctl_wmem_max = 32767;
1245 		sysctl_rmem_max = 32767;
1246 		sysctl_wmem_default = 32767;
1247 		sysctl_rmem_default = 32767;
1248 	} else if (totalram_pages >= 131072) {
1249 		sysctl_wmem_max = 131071;
1250 		sysctl_rmem_max = 131071;
1251 	}
1252 }
1253 
1254 /*
1255  *	Simple resource managers for sockets.
1256  */
1257 
1258 
1259 /*
1260  * Write buffer destructor automatically called from kfree_skb.
1261  */
1262 void sock_wfree(struct sk_buff *skb)
1263 {
1264 	struct sock *sk = skb->sk;
1265 	unsigned int len = skb->truesize;
1266 
1267 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1268 		/*
1269 		 * Keep a reference on sk_wmem_alloc, this will be released
1270 		 * after sk_write_space() call
1271 		 */
1272 		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1273 		sk->sk_write_space(sk);
1274 		len = 1;
1275 	}
1276 	/*
1277 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1278 	 * could not do because of in-flight packets
1279 	 */
1280 	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1281 		__sk_free(sk);
1282 }
1283 EXPORT_SYMBOL(sock_wfree);
1284 
1285 /*
1286  * Read buffer destructor automatically called from kfree_skb.
1287  */
1288 void sock_rfree(struct sk_buff *skb)
1289 {
1290 	struct sock *sk = skb->sk;
1291 
1292 	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1293 	sk_mem_uncharge(skb->sk, skb->truesize);
1294 }
1295 EXPORT_SYMBOL(sock_rfree);
1296 
1297 
1298 int sock_i_uid(struct sock *sk)
1299 {
1300 	int uid;
1301 
1302 	read_lock(&sk->sk_callback_lock);
1303 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1304 	read_unlock(&sk->sk_callback_lock);
1305 	return uid;
1306 }
1307 EXPORT_SYMBOL(sock_i_uid);
1308 
1309 unsigned long sock_i_ino(struct sock *sk)
1310 {
1311 	unsigned long ino;
1312 
1313 	read_lock(&sk->sk_callback_lock);
1314 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1315 	read_unlock(&sk->sk_callback_lock);
1316 	return ino;
1317 }
1318 EXPORT_SYMBOL(sock_i_ino);
1319 
1320 /*
1321  * Allocate a skb from the socket's send buffer.
1322  */
1323 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1324 			     gfp_t priority)
1325 {
1326 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1327 		struct sk_buff *skb = alloc_skb(size, priority);
1328 		if (skb) {
1329 			skb_set_owner_w(skb, sk);
1330 			return skb;
1331 		}
1332 	}
1333 	return NULL;
1334 }
1335 EXPORT_SYMBOL(sock_wmalloc);
1336 
1337 /*
1338  * Allocate a skb from the socket's receive buffer.
1339  */
1340 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1341 			     gfp_t priority)
1342 {
1343 	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1344 		struct sk_buff *skb = alloc_skb(size, priority);
1345 		if (skb) {
1346 			skb_set_owner_r(skb, sk);
1347 			return skb;
1348 		}
1349 	}
1350 	return NULL;
1351 }
1352 
1353 /*
1354  * Allocate a memory block from the socket's option memory buffer.
1355  */
1356 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1357 {
1358 	if ((unsigned)size <= sysctl_optmem_max &&
1359 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1360 		void *mem;
1361 		/* First do the add, to avoid the race if kmalloc
1362 		 * might sleep.
1363 		 */
1364 		atomic_add(size, &sk->sk_omem_alloc);
1365 		mem = kmalloc(size, priority);
1366 		if (mem)
1367 			return mem;
1368 		atomic_sub(size, &sk->sk_omem_alloc);
1369 	}
1370 	return NULL;
1371 }
1372 EXPORT_SYMBOL(sock_kmalloc);
1373 
1374 /*
1375  * Free an option memory block.
1376  */
1377 void sock_kfree_s(struct sock *sk, void *mem, int size)
1378 {
1379 	kfree(mem);
1380 	atomic_sub(size, &sk->sk_omem_alloc);
1381 }
1382 EXPORT_SYMBOL(sock_kfree_s);
1383 
1384 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1385    I think, these locks should be removed for datagram sockets.
1386  */
1387 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1388 {
1389 	DEFINE_WAIT(wait);
1390 
1391 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1392 	for (;;) {
1393 		if (!timeo)
1394 			break;
1395 		if (signal_pending(current))
1396 			break;
1397 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1398 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1399 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1400 			break;
1401 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1402 			break;
1403 		if (sk->sk_err)
1404 			break;
1405 		timeo = schedule_timeout(timeo);
1406 	}
1407 	finish_wait(sk->sk_sleep, &wait);
1408 	return timeo;
1409 }
1410 
1411 
1412 /*
1413  *	Generic send/receive buffer handlers
1414  */
1415 
1416 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1417 				     unsigned long data_len, int noblock,
1418 				     int *errcode)
1419 {
1420 	struct sk_buff *skb;
1421 	gfp_t gfp_mask;
1422 	long timeo;
1423 	int err;
1424 
1425 	gfp_mask = sk->sk_allocation;
1426 	if (gfp_mask & __GFP_WAIT)
1427 		gfp_mask |= __GFP_REPEAT;
1428 
1429 	timeo = sock_sndtimeo(sk, noblock);
1430 	while (1) {
1431 		err = sock_error(sk);
1432 		if (err != 0)
1433 			goto failure;
1434 
1435 		err = -EPIPE;
1436 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1437 			goto failure;
1438 
1439 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1440 			skb = alloc_skb(header_len, gfp_mask);
1441 			if (skb) {
1442 				int npages;
1443 				int i;
1444 
1445 				/* No pages, we're done... */
1446 				if (!data_len)
1447 					break;
1448 
1449 				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1450 				skb->truesize += data_len;
1451 				skb_shinfo(skb)->nr_frags = npages;
1452 				for (i = 0; i < npages; i++) {
1453 					struct page *page;
1454 					skb_frag_t *frag;
1455 
1456 					page = alloc_pages(sk->sk_allocation, 0);
1457 					if (!page) {
1458 						err = -ENOBUFS;
1459 						skb_shinfo(skb)->nr_frags = i;
1460 						kfree_skb(skb);
1461 						goto failure;
1462 					}
1463 
1464 					frag = &skb_shinfo(skb)->frags[i];
1465 					frag->page = page;
1466 					frag->page_offset = 0;
1467 					frag->size = (data_len >= PAGE_SIZE ?
1468 						      PAGE_SIZE :
1469 						      data_len);
1470 					data_len -= PAGE_SIZE;
1471 				}
1472 
1473 				/* Full success... */
1474 				break;
1475 			}
1476 			err = -ENOBUFS;
1477 			goto failure;
1478 		}
1479 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1480 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1481 		err = -EAGAIN;
1482 		if (!timeo)
1483 			goto failure;
1484 		if (signal_pending(current))
1485 			goto interrupted;
1486 		timeo = sock_wait_for_wmem(sk, timeo);
1487 	}
1488 
1489 	skb_set_owner_w(skb, sk);
1490 	return skb;
1491 
1492 interrupted:
1493 	err = sock_intr_errno(timeo);
1494 failure:
1495 	*errcode = err;
1496 	return NULL;
1497 }
1498 EXPORT_SYMBOL(sock_alloc_send_pskb);
1499 
1500 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1501 				    int noblock, int *errcode)
1502 {
1503 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1504 }
1505 EXPORT_SYMBOL(sock_alloc_send_skb);
1506 
1507 static void __lock_sock(struct sock *sk)
1508 {
1509 	DEFINE_WAIT(wait);
1510 
1511 	for (;;) {
1512 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1513 					TASK_UNINTERRUPTIBLE);
1514 		spin_unlock_bh(&sk->sk_lock.slock);
1515 		schedule();
1516 		spin_lock_bh(&sk->sk_lock.slock);
1517 		if (!sock_owned_by_user(sk))
1518 			break;
1519 	}
1520 	finish_wait(&sk->sk_lock.wq, &wait);
1521 }
1522 
1523 static void __release_sock(struct sock *sk)
1524 {
1525 	struct sk_buff *skb = sk->sk_backlog.head;
1526 
1527 	do {
1528 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1529 		bh_unlock_sock(sk);
1530 
1531 		do {
1532 			struct sk_buff *next = skb->next;
1533 
1534 			skb->next = NULL;
1535 			sk_backlog_rcv(sk, skb);
1536 
1537 			/*
1538 			 * We are in process context here with softirqs
1539 			 * disabled, use cond_resched_softirq() to preempt.
1540 			 * This is safe to do because we've taken the backlog
1541 			 * queue private:
1542 			 */
1543 			cond_resched_softirq();
1544 
1545 			skb = next;
1546 		} while (skb != NULL);
1547 
1548 		bh_lock_sock(sk);
1549 	} while ((skb = sk->sk_backlog.head) != NULL);
1550 
1551 	/*
1552 	 * Doing the zeroing here guarantee we can not loop forever
1553 	 * while a wild producer attempts to flood us.
1554 	 */
1555 	sk->sk_backlog.len = 0;
1556 }
1557 
1558 /**
1559  * sk_wait_data - wait for data to arrive at sk_receive_queue
1560  * @sk:    sock to wait on
1561  * @timeo: for how long
1562  *
1563  * Now socket state including sk->sk_err is changed only under lock,
1564  * hence we may omit checks after joining wait queue.
1565  * We check receive queue before schedule() only as optimization;
1566  * it is very likely that release_sock() added new data.
1567  */
1568 int sk_wait_data(struct sock *sk, long *timeo)
1569 {
1570 	int rc;
1571 	DEFINE_WAIT(wait);
1572 
1573 	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1574 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1575 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1576 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1577 	finish_wait(sk->sk_sleep, &wait);
1578 	return rc;
1579 }
1580 EXPORT_SYMBOL(sk_wait_data);
1581 
1582 /**
1583  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1584  *	@sk: socket
1585  *	@size: memory size to allocate
1586  *	@kind: allocation type
1587  *
1588  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1589  *	rmem allocation. This function assumes that protocols which have
1590  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1591  */
1592 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1593 {
1594 	struct proto *prot = sk->sk_prot;
1595 	int amt = sk_mem_pages(size);
1596 	int allocated;
1597 
1598 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1599 	allocated = atomic_add_return(amt, prot->memory_allocated);
1600 
1601 	/* Under limit. */
1602 	if (allocated <= prot->sysctl_mem[0]) {
1603 		if (prot->memory_pressure && *prot->memory_pressure)
1604 			*prot->memory_pressure = 0;
1605 		return 1;
1606 	}
1607 
1608 	/* Under pressure. */
1609 	if (allocated > prot->sysctl_mem[1])
1610 		if (prot->enter_memory_pressure)
1611 			prot->enter_memory_pressure(sk);
1612 
1613 	/* Over hard limit. */
1614 	if (allocated > prot->sysctl_mem[2])
1615 		goto suppress_allocation;
1616 
1617 	/* guarantee minimum buffer size under pressure */
1618 	if (kind == SK_MEM_RECV) {
1619 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1620 			return 1;
1621 	} else { /* SK_MEM_SEND */
1622 		if (sk->sk_type == SOCK_STREAM) {
1623 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1624 				return 1;
1625 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1626 			   prot->sysctl_wmem[0])
1627 				return 1;
1628 	}
1629 
1630 	if (prot->memory_pressure) {
1631 		int alloc;
1632 
1633 		if (!*prot->memory_pressure)
1634 			return 1;
1635 		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1636 		if (prot->sysctl_mem[2] > alloc *
1637 		    sk_mem_pages(sk->sk_wmem_queued +
1638 				 atomic_read(&sk->sk_rmem_alloc) +
1639 				 sk->sk_forward_alloc))
1640 			return 1;
1641 	}
1642 
1643 suppress_allocation:
1644 
1645 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1646 		sk_stream_moderate_sndbuf(sk);
1647 
1648 		/* Fail only if socket is _under_ its sndbuf.
1649 		 * In this case we cannot block, so that we have to fail.
1650 		 */
1651 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1652 			return 1;
1653 	}
1654 
1655 	/* Alas. Undo changes. */
1656 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1657 	atomic_sub(amt, prot->memory_allocated);
1658 	return 0;
1659 }
1660 EXPORT_SYMBOL(__sk_mem_schedule);
1661 
1662 /**
1663  *	__sk_reclaim - reclaim memory_allocated
1664  *	@sk: socket
1665  */
1666 void __sk_mem_reclaim(struct sock *sk)
1667 {
1668 	struct proto *prot = sk->sk_prot;
1669 
1670 	atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1671 		   prot->memory_allocated);
1672 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1673 
1674 	if (prot->memory_pressure && *prot->memory_pressure &&
1675 	    (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1676 		*prot->memory_pressure = 0;
1677 }
1678 EXPORT_SYMBOL(__sk_mem_reclaim);
1679 
1680 
1681 /*
1682  * Set of default routines for initialising struct proto_ops when
1683  * the protocol does not support a particular function. In certain
1684  * cases where it makes no sense for a protocol to have a "do nothing"
1685  * function, some default processing is provided.
1686  */
1687 
1688 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1689 {
1690 	return -EOPNOTSUPP;
1691 }
1692 EXPORT_SYMBOL(sock_no_bind);
1693 
1694 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1695 		    int len, int flags)
1696 {
1697 	return -EOPNOTSUPP;
1698 }
1699 EXPORT_SYMBOL(sock_no_connect);
1700 
1701 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1702 {
1703 	return -EOPNOTSUPP;
1704 }
1705 EXPORT_SYMBOL(sock_no_socketpair);
1706 
1707 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1708 {
1709 	return -EOPNOTSUPP;
1710 }
1711 EXPORT_SYMBOL(sock_no_accept);
1712 
1713 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1714 		    int *len, int peer)
1715 {
1716 	return -EOPNOTSUPP;
1717 }
1718 EXPORT_SYMBOL(sock_no_getname);
1719 
1720 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1721 {
1722 	return 0;
1723 }
1724 EXPORT_SYMBOL(sock_no_poll);
1725 
1726 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1727 {
1728 	return -EOPNOTSUPP;
1729 }
1730 EXPORT_SYMBOL(sock_no_ioctl);
1731 
1732 int sock_no_listen(struct socket *sock, int backlog)
1733 {
1734 	return -EOPNOTSUPP;
1735 }
1736 EXPORT_SYMBOL(sock_no_listen);
1737 
1738 int sock_no_shutdown(struct socket *sock, int how)
1739 {
1740 	return -EOPNOTSUPP;
1741 }
1742 EXPORT_SYMBOL(sock_no_shutdown);
1743 
1744 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1745 		    char __user *optval, unsigned int optlen)
1746 {
1747 	return -EOPNOTSUPP;
1748 }
1749 EXPORT_SYMBOL(sock_no_setsockopt);
1750 
1751 int sock_no_getsockopt(struct socket *sock, int level, int optname,
1752 		    char __user *optval, int __user *optlen)
1753 {
1754 	return -EOPNOTSUPP;
1755 }
1756 EXPORT_SYMBOL(sock_no_getsockopt);
1757 
1758 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1759 		    size_t len)
1760 {
1761 	return -EOPNOTSUPP;
1762 }
1763 EXPORT_SYMBOL(sock_no_sendmsg);
1764 
1765 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1766 		    size_t len, int flags)
1767 {
1768 	return -EOPNOTSUPP;
1769 }
1770 EXPORT_SYMBOL(sock_no_recvmsg);
1771 
1772 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1773 {
1774 	/* Mirror missing mmap method error code */
1775 	return -ENODEV;
1776 }
1777 EXPORT_SYMBOL(sock_no_mmap);
1778 
1779 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1780 {
1781 	ssize_t res;
1782 	struct msghdr msg = {.msg_flags = flags};
1783 	struct kvec iov;
1784 	char *kaddr = kmap(page);
1785 	iov.iov_base = kaddr + offset;
1786 	iov.iov_len = size;
1787 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1788 	kunmap(page);
1789 	return res;
1790 }
1791 EXPORT_SYMBOL(sock_no_sendpage);
1792 
1793 /*
1794  *	Default Socket Callbacks
1795  */
1796 
1797 static void sock_def_wakeup(struct sock *sk)
1798 {
1799 	read_lock(&sk->sk_callback_lock);
1800 	if (sk_has_sleeper(sk))
1801 		wake_up_interruptible_all(sk->sk_sleep);
1802 	read_unlock(&sk->sk_callback_lock);
1803 }
1804 
1805 static void sock_def_error_report(struct sock *sk)
1806 {
1807 	read_lock(&sk->sk_callback_lock);
1808 	if (sk_has_sleeper(sk))
1809 		wake_up_interruptible_poll(sk->sk_sleep, POLLERR);
1810 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1811 	read_unlock(&sk->sk_callback_lock);
1812 }
1813 
1814 static void sock_def_readable(struct sock *sk, int len)
1815 {
1816 	read_lock(&sk->sk_callback_lock);
1817 	if (sk_has_sleeper(sk))
1818 		wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN |
1819 						POLLRDNORM | POLLRDBAND);
1820 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1821 	read_unlock(&sk->sk_callback_lock);
1822 }
1823 
1824 static void sock_def_write_space(struct sock *sk)
1825 {
1826 	read_lock(&sk->sk_callback_lock);
1827 
1828 	/* Do not wake up a writer until he can make "significant"
1829 	 * progress.  --DaveM
1830 	 */
1831 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1832 		if (sk_has_sleeper(sk))
1833 			wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
1834 						POLLWRNORM | POLLWRBAND);
1835 
1836 		/* Should agree with poll, otherwise some programs break */
1837 		if (sock_writeable(sk))
1838 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1839 	}
1840 
1841 	read_unlock(&sk->sk_callback_lock);
1842 }
1843 
1844 static void sock_def_destruct(struct sock *sk)
1845 {
1846 	kfree(sk->sk_protinfo);
1847 }
1848 
1849 void sk_send_sigurg(struct sock *sk)
1850 {
1851 	if (sk->sk_socket && sk->sk_socket->file)
1852 		if (send_sigurg(&sk->sk_socket->file->f_owner))
1853 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1854 }
1855 EXPORT_SYMBOL(sk_send_sigurg);
1856 
1857 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1858 		    unsigned long expires)
1859 {
1860 	if (!mod_timer(timer, expires))
1861 		sock_hold(sk);
1862 }
1863 EXPORT_SYMBOL(sk_reset_timer);
1864 
1865 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1866 {
1867 	if (timer_pending(timer) && del_timer(timer))
1868 		__sock_put(sk);
1869 }
1870 EXPORT_SYMBOL(sk_stop_timer);
1871 
1872 void sock_init_data(struct socket *sock, struct sock *sk)
1873 {
1874 	skb_queue_head_init(&sk->sk_receive_queue);
1875 	skb_queue_head_init(&sk->sk_write_queue);
1876 	skb_queue_head_init(&sk->sk_error_queue);
1877 #ifdef CONFIG_NET_DMA
1878 	skb_queue_head_init(&sk->sk_async_wait_queue);
1879 #endif
1880 
1881 	sk->sk_send_head	=	NULL;
1882 
1883 	init_timer(&sk->sk_timer);
1884 
1885 	sk->sk_allocation	=	GFP_KERNEL;
1886 	sk->sk_rcvbuf		=	sysctl_rmem_default;
1887 	sk->sk_sndbuf		=	sysctl_wmem_default;
1888 	sk->sk_backlog.limit	=	sk->sk_rcvbuf << 1;
1889 	sk->sk_state		=	TCP_CLOSE;
1890 	sk_set_socket(sk, sock);
1891 
1892 	sock_set_flag(sk, SOCK_ZAPPED);
1893 
1894 	if (sock) {
1895 		sk->sk_type	=	sock->type;
1896 		sk->sk_sleep	=	&sock->wait;
1897 		sock->sk	=	sk;
1898 	} else
1899 		sk->sk_sleep	=	NULL;
1900 
1901 	rwlock_init(&sk->sk_dst_lock);
1902 	rwlock_init(&sk->sk_callback_lock);
1903 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1904 			af_callback_keys + sk->sk_family,
1905 			af_family_clock_key_strings[sk->sk_family]);
1906 
1907 	sk->sk_state_change	=	sock_def_wakeup;
1908 	sk->sk_data_ready	=	sock_def_readable;
1909 	sk->sk_write_space	=	sock_def_write_space;
1910 	sk->sk_error_report	=	sock_def_error_report;
1911 	sk->sk_destruct		=	sock_def_destruct;
1912 
1913 	sk->sk_sndmsg_page	=	NULL;
1914 	sk->sk_sndmsg_off	=	0;
1915 
1916 	sk->sk_peercred.pid 	=	0;
1917 	sk->sk_peercred.uid	=	-1;
1918 	sk->sk_peercred.gid	=	-1;
1919 	sk->sk_write_pending	=	0;
1920 	sk->sk_rcvlowat		=	1;
1921 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1922 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1923 
1924 	sk->sk_stamp = ktime_set(-1L, 0);
1925 
1926 	/*
1927 	 * Before updating sk_refcnt, we must commit prior changes to memory
1928 	 * (Documentation/RCU/rculist_nulls.txt for details)
1929 	 */
1930 	smp_wmb();
1931 	atomic_set(&sk->sk_refcnt, 1);
1932 	atomic_set(&sk->sk_drops, 0);
1933 }
1934 EXPORT_SYMBOL(sock_init_data);
1935 
1936 void lock_sock_nested(struct sock *sk, int subclass)
1937 {
1938 	might_sleep();
1939 	spin_lock_bh(&sk->sk_lock.slock);
1940 	if (sk->sk_lock.owned)
1941 		__lock_sock(sk);
1942 	sk->sk_lock.owned = 1;
1943 	spin_unlock(&sk->sk_lock.slock);
1944 	/*
1945 	 * The sk_lock has mutex_lock() semantics here:
1946 	 */
1947 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
1948 	local_bh_enable();
1949 }
1950 EXPORT_SYMBOL(lock_sock_nested);
1951 
1952 void release_sock(struct sock *sk)
1953 {
1954 	/*
1955 	 * The sk_lock has mutex_unlock() semantics:
1956 	 */
1957 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1958 
1959 	spin_lock_bh(&sk->sk_lock.slock);
1960 	if (sk->sk_backlog.tail)
1961 		__release_sock(sk);
1962 	sk->sk_lock.owned = 0;
1963 	if (waitqueue_active(&sk->sk_lock.wq))
1964 		wake_up(&sk->sk_lock.wq);
1965 	spin_unlock_bh(&sk->sk_lock.slock);
1966 }
1967 EXPORT_SYMBOL(release_sock);
1968 
1969 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1970 {
1971 	struct timeval tv;
1972 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1973 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1974 	tv = ktime_to_timeval(sk->sk_stamp);
1975 	if (tv.tv_sec == -1)
1976 		return -ENOENT;
1977 	if (tv.tv_sec == 0) {
1978 		sk->sk_stamp = ktime_get_real();
1979 		tv = ktime_to_timeval(sk->sk_stamp);
1980 	}
1981 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
1982 }
1983 EXPORT_SYMBOL(sock_get_timestamp);
1984 
1985 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
1986 {
1987 	struct timespec ts;
1988 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1989 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1990 	ts = ktime_to_timespec(sk->sk_stamp);
1991 	if (ts.tv_sec == -1)
1992 		return -ENOENT;
1993 	if (ts.tv_sec == 0) {
1994 		sk->sk_stamp = ktime_get_real();
1995 		ts = ktime_to_timespec(sk->sk_stamp);
1996 	}
1997 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
1998 }
1999 EXPORT_SYMBOL(sock_get_timestampns);
2000 
2001 void sock_enable_timestamp(struct sock *sk, int flag)
2002 {
2003 	if (!sock_flag(sk, flag)) {
2004 		sock_set_flag(sk, flag);
2005 		/*
2006 		 * we just set one of the two flags which require net
2007 		 * time stamping, but time stamping might have been on
2008 		 * already because of the other one
2009 		 */
2010 		if (!sock_flag(sk,
2011 				flag == SOCK_TIMESTAMP ?
2012 				SOCK_TIMESTAMPING_RX_SOFTWARE :
2013 				SOCK_TIMESTAMP))
2014 			net_enable_timestamp();
2015 	}
2016 }
2017 
2018 /*
2019  *	Get a socket option on an socket.
2020  *
2021  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2022  *	asynchronous errors should be reported by getsockopt. We assume
2023  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2024  */
2025 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2026 			   char __user *optval, int __user *optlen)
2027 {
2028 	struct sock *sk = sock->sk;
2029 
2030 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2031 }
2032 EXPORT_SYMBOL(sock_common_getsockopt);
2033 
2034 #ifdef CONFIG_COMPAT
2035 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2036 				  char __user *optval, int __user *optlen)
2037 {
2038 	struct sock *sk = sock->sk;
2039 
2040 	if (sk->sk_prot->compat_getsockopt != NULL)
2041 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2042 						      optval, optlen);
2043 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2044 }
2045 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2046 #endif
2047 
2048 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2049 			struct msghdr *msg, size_t size, int flags)
2050 {
2051 	struct sock *sk = sock->sk;
2052 	int addr_len = 0;
2053 	int err;
2054 
2055 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2056 				   flags & ~MSG_DONTWAIT, &addr_len);
2057 	if (err >= 0)
2058 		msg->msg_namelen = addr_len;
2059 	return err;
2060 }
2061 EXPORT_SYMBOL(sock_common_recvmsg);
2062 
2063 /*
2064  *	Set socket options on an inet socket.
2065  */
2066 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2067 			   char __user *optval, unsigned int optlen)
2068 {
2069 	struct sock *sk = sock->sk;
2070 
2071 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2072 }
2073 EXPORT_SYMBOL(sock_common_setsockopt);
2074 
2075 #ifdef CONFIG_COMPAT
2076 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2077 				  char __user *optval, unsigned int optlen)
2078 {
2079 	struct sock *sk = sock->sk;
2080 
2081 	if (sk->sk_prot->compat_setsockopt != NULL)
2082 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2083 						      optval, optlen);
2084 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2085 }
2086 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2087 #endif
2088 
2089 void sk_common_release(struct sock *sk)
2090 {
2091 	if (sk->sk_prot->destroy)
2092 		sk->sk_prot->destroy(sk);
2093 
2094 	/*
2095 	 * Observation: when sock_common_release is called, processes have
2096 	 * no access to socket. But net still has.
2097 	 * Step one, detach it from networking:
2098 	 *
2099 	 * A. Remove from hash tables.
2100 	 */
2101 
2102 	sk->sk_prot->unhash(sk);
2103 
2104 	/*
2105 	 * In this point socket cannot receive new packets, but it is possible
2106 	 * that some packets are in flight because some CPU runs receiver and
2107 	 * did hash table lookup before we unhashed socket. They will achieve
2108 	 * receive queue and will be purged by socket destructor.
2109 	 *
2110 	 * Also we still have packets pending on receive queue and probably,
2111 	 * our own packets waiting in device queues. sock_destroy will drain
2112 	 * receive queue, but transmitted packets will delay socket destruction
2113 	 * until the last reference will be released.
2114 	 */
2115 
2116 	sock_orphan(sk);
2117 
2118 	xfrm_sk_free_policy(sk);
2119 
2120 	sk_refcnt_debug_release(sk);
2121 	sock_put(sk);
2122 }
2123 EXPORT_SYMBOL(sk_common_release);
2124 
2125 static DEFINE_RWLOCK(proto_list_lock);
2126 static LIST_HEAD(proto_list);
2127 
2128 #ifdef CONFIG_PROC_FS
2129 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2130 struct prot_inuse {
2131 	int val[PROTO_INUSE_NR];
2132 };
2133 
2134 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2135 
2136 #ifdef CONFIG_NET_NS
2137 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2138 {
2139 	int cpu = smp_processor_id();
2140 	per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
2141 }
2142 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2143 
2144 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2145 {
2146 	int cpu, idx = prot->inuse_idx;
2147 	int res = 0;
2148 
2149 	for_each_possible_cpu(cpu)
2150 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2151 
2152 	return res >= 0 ? res : 0;
2153 }
2154 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2155 
2156 static int __net_init sock_inuse_init_net(struct net *net)
2157 {
2158 	net->core.inuse = alloc_percpu(struct prot_inuse);
2159 	return net->core.inuse ? 0 : -ENOMEM;
2160 }
2161 
2162 static void __net_exit sock_inuse_exit_net(struct net *net)
2163 {
2164 	free_percpu(net->core.inuse);
2165 }
2166 
2167 static struct pernet_operations net_inuse_ops = {
2168 	.init = sock_inuse_init_net,
2169 	.exit = sock_inuse_exit_net,
2170 };
2171 
2172 static __init int net_inuse_init(void)
2173 {
2174 	if (register_pernet_subsys(&net_inuse_ops))
2175 		panic("Cannot initialize net inuse counters");
2176 
2177 	return 0;
2178 }
2179 
2180 core_initcall(net_inuse_init);
2181 #else
2182 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2183 
2184 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2185 {
2186 	__get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
2187 }
2188 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2189 
2190 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2191 {
2192 	int cpu, idx = prot->inuse_idx;
2193 	int res = 0;
2194 
2195 	for_each_possible_cpu(cpu)
2196 		res += per_cpu(prot_inuse, cpu).val[idx];
2197 
2198 	return res >= 0 ? res : 0;
2199 }
2200 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2201 #endif
2202 
2203 static void assign_proto_idx(struct proto *prot)
2204 {
2205 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2206 
2207 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2208 		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2209 		return;
2210 	}
2211 
2212 	set_bit(prot->inuse_idx, proto_inuse_idx);
2213 }
2214 
2215 static void release_proto_idx(struct proto *prot)
2216 {
2217 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2218 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2219 }
2220 #else
2221 static inline void assign_proto_idx(struct proto *prot)
2222 {
2223 }
2224 
2225 static inline void release_proto_idx(struct proto *prot)
2226 {
2227 }
2228 #endif
2229 
2230 int proto_register(struct proto *prot, int alloc_slab)
2231 {
2232 	if (alloc_slab) {
2233 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2234 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2235 					NULL);
2236 
2237 		if (prot->slab == NULL) {
2238 			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2239 			       prot->name);
2240 			goto out;
2241 		}
2242 
2243 		if (prot->rsk_prot != NULL) {
2244 			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2245 			if (prot->rsk_prot->slab_name == NULL)
2246 				goto out_free_sock_slab;
2247 
2248 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2249 								 prot->rsk_prot->obj_size, 0,
2250 								 SLAB_HWCACHE_ALIGN, NULL);
2251 
2252 			if (prot->rsk_prot->slab == NULL) {
2253 				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2254 				       prot->name);
2255 				goto out_free_request_sock_slab_name;
2256 			}
2257 		}
2258 
2259 		if (prot->twsk_prot != NULL) {
2260 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2261 
2262 			if (prot->twsk_prot->twsk_slab_name == NULL)
2263 				goto out_free_request_sock_slab;
2264 
2265 			prot->twsk_prot->twsk_slab =
2266 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2267 						  prot->twsk_prot->twsk_obj_size,
2268 						  0,
2269 						  SLAB_HWCACHE_ALIGN |
2270 							prot->slab_flags,
2271 						  NULL);
2272 			if (prot->twsk_prot->twsk_slab == NULL)
2273 				goto out_free_timewait_sock_slab_name;
2274 		}
2275 	}
2276 
2277 	write_lock(&proto_list_lock);
2278 	list_add(&prot->node, &proto_list);
2279 	assign_proto_idx(prot);
2280 	write_unlock(&proto_list_lock);
2281 	return 0;
2282 
2283 out_free_timewait_sock_slab_name:
2284 	kfree(prot->twsk_prot->twsk_slab_name);
2285 out_free_request_sock_slab:
2286 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2287 		kmem_cache_destroy(prot->rsk_prot->slab);
2288 		prot->rsk_prot->slab = NULL;
2289 	}
2290 out_free_request_sock_slab_name:
2291 	if (prot->rsk_prot)
2292 		kfree(prot->rsk_prot->slab_name);
2293 out_free_sock_slab:
2294 	kmem_cache_destroy(prot->slab);
2295 	prot->slab = NULL;
2296 out:
2297 	return -ENOBUFS;
2298 }
2299 EXPORT_SYMBOL(proto_register);
2300 
2301 void proto_unregister(struct proto *prot)
2302 {
2303 	write_lock(&proto_list_lock);
2304 	release_proto_idx(prot);
2305 	list_del(&prot->node);
2306 	write_unlock(&proto_list_lock);
2307 
2308 	if (prot->slab != NULL) {
2309 		kmem_cache_destroy(prot->slab);
2310 		prot->slab = NULL;
2311 	}
2312 
2313 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2314 		kmem_cache_destroy(prot->rsk_prot->slab);
2315 		kfree(prot->rsk_prot->slab_name);
2316 		prot->rsk_prot->slab = NULL;
2317 	}
2318 
2319 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2320 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2321 		kfree(prot->twsk_prot->twsk_slab_name);
2322 		prot->twsk_prot->twsk_slab = NULL;
2323 	}
2324 }
2325 EXPORT_SYMBOL(proto_unregister);
2326 
2327 #ifdef CONFIG_PROC_FS
2328 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2329 	__acquires(proto_list_lock)
2330 {
2331 	read_lock(&proto_list_lock);
2332 	return seq_list_start_head(&proto_list, *pos);
2333 }
2334 
2335 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2336 {
2337 	return seq_list_next(v, &proto_list, pos);
2338 }
2339 
2340 static void proto_seq_stop(struct seq_file *seq, void *v)
2341 	__releases(proto_list_lock)
2342 {
2343 	read_unlock(&proto_list_lock);
2344 }
2345 
2346 static char proto_method_implemented(const void *method)
2347 {
2348 	return method == NULL ? 'n' : 'y';
2349 }
2350 
2351 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2352 {
2353 	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
2354 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2355 		   proto->name,
2356 		   proto->obj_size,
2357 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2358 		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
2359 		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2360 		   proto->max_header,
2361 		   proto->slab == NULL ? "no" : "yes",
2362 		   module_name(proto->owner),
2363 		   proto_method_implemented(proto->close),
2364 		   proto_method_implemented(proto->connect),
2365 		   proto_method_implemented(proto->disconnect),
2366 		   proto_method_implemented(proto->accept),
2367 		   proto_method_implemented(proto->ioctl),
2368 		   proto_method_implemented(proto->init),
2369 		   proto_method_implemented(proto->destroy),
2370 		   proto_method_implemented(proto->shutdown),
2371 		   proto_method_implemented(proto->setsockopt),
2372 		   proto_method_implemented(proto->getsockopt),
2373 		   proto_method_implemented(proto->sendmsg),
2374 		   proto_method_implemented(proto->recvmsg),
2375 		   proto_method_implemented(proto->sendpage),
2376 		   proto_method_implemented(proto->bind),
2377 		   proto_method_implemented(proto->backlog_rcv),
2378 		   proto_method_implemented(proto->hash),
2379 		   proto_method_implemented(proto->unhash),
2380 		   proto_method_implemented(proto->get_port),
2381 		   proto_method_implemented(proto->enter_memory_pressure));
2382 }
2383 
2384 static int proto_seq_show(struct seq_file *seq, void *v)
2385 {
2386 	if (v == &proto_list)
2387 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2388 			   "protocol",
2389 			   "size",
2390 			   "sockets",
2391 			   "memory",
2392 			   "press",
2393 			   "maxhdr",
2394 			   "slab",
2395 			   "module",
2396 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2397 	else
2398 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2399 	return 0;
2400 }
2401 
2402 static const struct seq_operations proto_seq_ops = {
2403 	.start  = proto_seq_start,
2404 	.next   = proto_seq_next,
2405 	.stop   = proto_seq_stop,
2406 	.show   = proto_seq_show,
2407 };
2408 
2409 static int proto_seq_open(struct inode *inode, struct file *file)
2410 {
2411 	return seq_open_net(inode, file, &proto_seq_ops,
2412 			    sizeof(struct seq_net_private));
2413 }
2414 
2415 static const struct file_operations proto_seq_fops = {
2416 	.owner		= THIS_MODULE,
2417 	.open		= proto_seq_open,
2418 	.read		= seq_read,
2419 	.llseek		= seq_lseek,
2420 	.release	= seq_release_net,
2421 };
2422 
2423 static __net_init int proto_init_net(struct net *net)
2424 {
2425 	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2426 		return -ENOMEM;
2427 
2428 	return 0;
2429 }
2430 
2431 static __net_exit void proto_exit_net(struct net *net)
2432 {
2433 	proc_net_remove(net, "protocols");
2434 }
2435 
2436 
2437 static __net_initdata struct pernet_operations proto_net_ops = {
2438 	.init = proto_init_net,
2439 	.exit = proto_exit_net,
2440 };
2441 
2442 static int __init proto_init(void)
2443 {
2444 	return register_pernet_subsys(&proto_net_ops);
2445 }
2446 
2447 subsys_initcall(proto_init);
2448 
2449 #endif /* PROC_FS */
2450