xref: /openbmc/linux/net/core/sock.c (revision 7fe2f639)
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 #include <linux/user_namespace.h>
114 
115 #include <asm/uaccess.h>
116 #include <asm/system.h>
117 
118 #include <linux/netdevice.h>
119 #include <net/protocol.h>
120 #include <linux/skbuff.h>
121 #include <net/net_namespace.h>
122 #include <net/request_sock.h>
123 #include <net/sock.h>
124 #include <linux/net_tstamp.h>
125 #include <net/xfrm.h>
126 #include <linux/ipsec.h>
127 #include <net/cls_cgroup.h>
128 
129 #include <linux/filter.h>
130 
131 #ifdef CONFIG_INET
132 #include <net/tcp.h>
133 #endif
134 
135 /*
136  * Each address family might have different locking rules, so we have
137  * one slock key per address family:
138  */
139 static struct lock_class_key af_family_keys[AF_MAX];
140 static struct lock_class_key af_family_slock_keys[AF_MAX];
141 
142 /*
143  * Make lock validator output more readable. (we pre-construct these
144  * strings build-time, so that runtime initialization of socket
145  * locks is fast):
146  */
147 static const char *const af_family_key_strings[AF_MAX+1] = {
148   "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
149   "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
150   "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
151   "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
152   "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
153   "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
154   "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
155   "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
156   "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
157   "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
158   "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
159   "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
160   "sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG"      ,
161   "sk_lock-AF_MAX"
162 };
163 static const char *const af_family_slock_key_strings[AF_MAX+1] = {
164   "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
165   "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
166   "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
167   "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
168   "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
169   "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
170   "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
171   "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
172   "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
173   "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
174   "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
175   "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
176   "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG"      ,
177   "slock-AF_MAX"
178 };
179 static const char *const af_family_clock_key_strings[AF_MAX+1] = {
180   "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
181   "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
182   "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
183   "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
184   "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
185   "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
186   "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
187   "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
188   "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
189   "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
190   "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
191   "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
192   "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG"      ,
193   "clock-AF_MAX"
194 };
195 
196 /*
197  * sk_callback_lock locking rules are per-address-family,
198  * so split the lock classes by using a per-AF key:
199  */
200 static struct lock_class_key af_callback_keys[AF_MAX];
201 
202 /* Take into consideration the size of the struct sk_buff overhead in the
203  * determination of these values, since that is non-constant across
204  * platforms.  This makes socket queueing behavior and performance
205  * not depend upon such differences.
206  */
207 #define _SK_MEM_PACKETS		256
208 #define _SK_MEM_OVERHEAD	(sizeof(struct sk_buff) + 256)
209 #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
210 #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
211 
212 /* Run time adjustable parameters. */
213 __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
214 __u32 sysctl_rmem_max __read_mostly = SK_RMEM_MAX;
215 __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
216 __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
217 
218 /* Maximal space eaten by iovec or ancillary data plus some space */
219 int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
220 EXPORT_SYMBOL(sysctl_optmem_max);
221 
222 #if defined(CONFIG_CGROUPS) && !defined(CONFIG_NET_CLS_CGROUP)
223 int net_cls_subsys_id = -1;
224 EXPORT_SYMBOL_GPL(net_cls_subsys_id);
225 #endif
226 
227 static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
228 {
229 	struct timeval tv;
230 
231 	if (optlen < sizeof(tv))
232 		return -EINVAL;
233 	if (copy_from_user(&tv, optval, sizeof(tv)))
234 		return -EFAULT;
235 	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
236 		return -EDOM;
237 
238 	if (tv.tv_sec < 0) {
239 		static int warned __read_mostly;
240 
241 		*timeo_p = 0;
242 		if (warned < 10 && net_ratelimit()) {
243 			warned++;
244 			printk(KERN_INFO "sock_set_timeout: `%s' (pid %d) "
245 			       "tries to set negative timeout\n",
246 				current->comm, task_pid_nr(current));
247 		}
248 		return 0;
249 	}
250 	*timeo_p = MAX_SCHEDULE_TIMEOUT;
251 	if (tv.tv_sec == 0 && tv.tv_usec == 0)
252 		return 0;
253 	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
254 		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
255 	return 0;
256 }
257 
258 static void sock_warn_obsolete_bsdism(const char *name)
259 {
260 	static int warned;
261 	static char warncomm[TASK_COMM_LEN];
262 	if (strcmp(warncomm, current->comm) && warned < 5) {
263 		strcpy(warncomm,  current->comm);
264 		printk(KERN_WARNING "process `%s' is using obsolete "
265 		       "%s SO_BSDCOMPAT\n", warncomm, name);
266 		warned++;
267 	}
268 }
269 
270 static void sock_disable_timestamp(struct sock *sk, int flag)
271 {
272 	if (sock_flag(sk, flag)) {
273 		sock_reset_flag(sk, flag);
274 		if (!sock_flag(sk, SOCK_TIMESTAMP) &&
275 		    !sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE)) {
276 			net_disable_timestamp();
277 		}
278 	}
279 }
280 
281 
282 int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
283 {
284 	int err;
285 	int skb_len;
286 	unsigned long flags;
287 	struct sk_buff_head *list = &sk->sk_receive_queue;
288 
289 	/* Cast sk->rcvbuf to unsigned... It's pointless, but reduces
290 	   number of warnings when compiling with -W --ANK
291 	 */
292 	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
293 	    (unsigned)sk->sk_rcvbuf) {
294 		atomic_inc(&sk->sk_drops);
295 		return -ENOMEM;
296 	}
297 
298 	err = sk_filter(sk, skb);
299 	if (err)
300 		return err;
301 
302 	if (!sk_rmem_schedule(sk, skb->truesize)) {
303 		atomic_inc(&sk->sk_drops);
304 		return -ENOBUFS;
305 	}
306 
307 	skb->dev = NULL;
308 	skb_set_owner_r(skb, sk);
309 
310 	/* Cache the SKB length before we tack it onto the receive
311 	 * queue.  Once it is added it no longer belongs to us and
312 	 * may be freed by other threads of control pulling packets
313 	 * from the queue.
314 	 */
315 	skb_len = skb->len;
316 
317 	/* we escape from rcu protected region, make sure we dont leak
318 	 * a norefcounted dst
319 	 */
320 	skb_dst_force(skb);
321 
322 	spin_lock_irqsave(&list->lock, flags);
323 	skb->dropcount = atomic_read(&sk->sk_drops);
324 	__skb_queue_tail(list, skb);
325 	spin_unlock_irqrestore(&list->lock, flags);
326 
327 	if (!sock_flag(sk, SOCK_DEAD))
328 		sk->sk_data_ready(sk, skb_len);
329 	return 0;
330 }
331 EXPORT_SYMBOL(sock_queue_rcv_skb);
332 
333 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
334 {
335 	int rc = NET_RX_SUCCESS;
336 
337 	if (sk_filter(sk, skb))
338 		goto discard_and_relse;
339 
340 	skb->dev = NULL;
341 
342 	if (sk_rcvqueues_full(sk, skb)) {
343 		atomic_inc(&sk->sk_drops);
344 		goto discard_and_relse;
345 	}
346 	if (nested)
347 		bh_lock_sock_nested(sk);
348 	else
349 		bh_lock_sock(sk);
350 	if (!sock_owned_by_user(sk)) {
351 		/*
352 		 * trylock + unlock semantics:
353 		 */
354 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
355 
356 		rc = sk_backlog_rcv(sk, skb);
357 
358 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
359 	} else if (sk_add_backlog(sk, skb)) {
360 		bh_unlock_sock(sk);
361 		atomic_inc(&sk->sk_drops);
362 		goto discard_and_relse;
363 	}
364 
365 	bh_unlock_sock(sk);
366 out:
367 	sock_put(sk);
368 	return rc;
369 discard_and_relse:
370 	kfree_skb(skb);
371 	goto out;
372 }
373 EXPORT_SYMBOL(sk_receive_skb);
374 
375 void sk_reset_txq(struct sock *sk)
376 {
377 	sk_tx_queue_clear(sk);
378 }
379 EXPORT_SYMBOL(sk_reset_txq);
380 
381 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
382 {
383 	struct dst_entry *dst = __sk_dst_get(sk);
384 
385 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
386 		sk_tx_queue_clear(sk);
387 		rcu_assign_pointer(sk->sk_dst_cache, NULL);
388 		dst_release(dst);
389 		return NULL;
390 	}
391 
392 	return dst;
393 }
394 EXPORT_SYMBOL(__sk_dst_check);
395 
396 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
397 {
398 	struct dst_entry *dst = sk_dst_get(sk);
399 
400 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
401 		sk_dst_reset(sk);
402 		dst_release(dst);
403 		return NULL;
404 	}
405 
406 	return dst;
407 }
408 EXPORT_SYMBOL(sk_dst_check);
409 
410 static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
411 {
412 	int ret = -ENOPROTOOPT;
413 #ifdef CONFIG_NETDEVICES
414 	struct net *net = sock_net(sk);
415 	char devname[IFNAMSIZ];
416 	int index;
417 
418 	/* Sorry... */
419 	ret = -EPERM;
420 	if (!capable(CAP_NET_RAW))
421 		goto out;
422 
423 	ret = -EINVAL;
424 	if (optlen < 0)
425 		goto out;
426 
427 	/* Bind this socket to a particular device like "eth0",
428 	 * as specified in the passed interface name. If the
429 	 * name is "" or the option length is zero the socket
430 	 * is not bound.
431 	 */
432 	if (optlen > IFNAMSIZ - 1)
433 		optlen = IFNAMSIZ - 1;
434 	memset(devname, 0, sizeof(devname));
435 
436 	ret = -EFAULT;
437 	if (copy_from_user(devname, optval, optlen))
438 		goto out;
439 
440 	index = 0;
441 	if (devname[0] != '\0') {
442 		struct net_device *dev;
443 
444 		rcu_read_lock();
445 		dev = dev_get_by_name_rcu(net, devname);
446 		if (dev)
447 			index = dev->ifindex;
448 		rcu_read_unlock();
449 		ret = -ENODEV;
450 		if (!dev)
451 			goto out;
452 	}
453 
454 	lock_sock(sk);
455 	sk->sk_bound_dev_if = index;
456 	sk_dst_reset(sk);
457 	release_sock(sk);
458 
459 	ret = 0;
460 
461 out:
462 #endif
463 
464 	return ret;
465 }
466 
467 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
468 {
469 	if (valbool)
470 		sock_set_flag(sk, bit);
471 	else
472 		sock_reset_flag(sk, bit);
473 }
474 
475 /*
476  *	This is meant for all protocols to use and covers goings on
477  *	at the socket level. Everything here is generic.
478  */
479 
480 int sock_setsockopt(struct socket *sock, int level, int optname,
481 		    char __user *optval, unsigned int optlen)
482 {
483 	struct sock *sk = sock->sk;
484 	int val;
485 	int valbool;
486 	struct linger ling;
487 	int ret = 0;
488 
489 	/*
490 	 *	Options without arguments
491 	 */
492 
493 	if (optname == SO_BINDTODEVICE)
494 		return sock_bindtodevice(sk, optval, optlen);
495 
496 	if (optlen < sizeof(int))
497 		return -EINVAL;
498 
499 	if (get_user(val, (int __user *)optval))
500 		return -EFAULT;
501 
502 	valbool = val ? 1 : 0;
503 
504 	lock_sock(sk);
505 
506 	switch (optname) {
507 	case SO_DEBUG:
508 		if (val && !capable(CAP_NET_ADMIN))
509 			ret = -EACCES;
510 		else
511 			sock_valbool_flag(sk, SOCK_DBG, valbool);
512 		break;
513 	case SO_REUSEADDR:
514 		sk->sk_reuse = valbool;
515 		break;
516 	case SO_TYPE:
517 	case SO_PROTOCOL:
518 	case SO_DOMAIN:
519 	case SO_ERROR:
520 		ret = -ENOPROTOOPT;
521 		break;
522 	case SO_DONTROUTE:
523 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
524 		break;
525 	case SO_BROADCAST:
526 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
527 		break;
528 	case SO_SNDBUF:
529 		/* Don't error on this BSD doesn't and if you think
530 		   about it this is right. Otherwise apps have to
531 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
532 		   are treated in BSD as hints */
533 
534 		if (val > sysctl_wmem_max)
535 			val = sysctl_wmem_max;
536 set_sndbuf:
537 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
538 		if ((val * 2) < SOCK_MIN_SNDBUF)
539 			sk->sk_sndbuf = SOCK_MIN_SNDBUF;
540 		else
541 			sk->sk_sndbuf = val * 2;
542 
543 		/*
544 		 *	Wake up sending tasks if we
545 		 *	upped the value.
546 		 */
547 		sk->sk_write_space(sk);
548 		break;
549 
550 	case SO_SNDBUFFORCE:
551 		if (!capable(CAP_NET_ADMIN)) {
552 			ret = -EPERM;
553 			break;
554 		}
555 		goto set_sndbuf;
556 
557 	case SO_RCVBUF:
558 		/* Don't error on this BSD doesn't and if you think
559 		   about it this is right. Otherwise apps have to
560 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
561 		   are treated in BSD as hints */
562 
563 		if (val > sysctl_rmem_max)
564 			val = sysctl_rmem_max;
565 set_rcvbuf:
566 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
567 		/*
568 		 * We double it on the way in to account for
569 		 * "struct sk_buff" etc. overhead.   Applications
570 		 * assume that the SO_RCVBUF setting they make will
571 		 * allow that much actual data to be received on that
572 		 * socket.
573 		 *
574 		 * Applications are unaware that "struct sk_buff" and
575 		 * other overheads allocate from the receive buffer
576 		 * during socket buffer allocation.
577 		 *
578 		 * And after considering the possible alternatives,
579 		 * returning the value we actually used in getsockopt
580 		 * is the most desirable behavior.
581 		 */
582 		if ((val * 2) < SOCK_MIN_RCVBUF)
583 			sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
584 		else
585 			sk->sk_rcvbuf = val * 2;
586 		break;
587 
588 	case SO_RCVBUFFORCE:
589 		if (!capable(CAP_NET_ADMIN)) {
590 			ret = -EPERM;
591 			break;
592 		}
593 		goto set_rcvbuf;
594 
595 	case SO_KEEPALIVE:
596 #ifdef CONFIG_INET
597 		if (sk->sk_protocol == IPPROTO_TCP)
598 			tcp_set_keepalive(sk, valbool);
599 #endif
600 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
601 		break;
602 
603 	case SO_OOBINLINE:
604 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
605 		break;
606 
607 	case SO_NO_CHECK:
608 		sk->sk_no_check = valbool;
609 		break;
610 
611 	case SO_PRIORITY:
612 		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
613 			sk->sk_priority = val;
614 		else
615 			ret = -EPERM;
616 		break;
617 
618 	case SO_LINGER:
619 		if (optlen < sizeof(ling)) {
620 			ret = -EINVAL;	/* 1003.1g */
621 			break;
622 		}
623 		if (copy_from_user(&ling, optval, sizeof(ling))) {
624 			ret = -EFAULT;
625 			break;
626 		}
627 		if (!ling.l_onoff)
628 			sock_reset_flag(sk, SOCK_LINGER);
629 		else {
630 #if (BITS_PER_LONG == 32)
631 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
632 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
633 			else
634 #endif
635 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
636 			sock_set_flag(sk, SOCK_LINGER);
637 		}
638 		break;
639 
640 	case SO_BSDCOMPAT:
641 		sock_warn_obsolete_bsdism("setsockopt");
642 		break;
643 
644 	case SO_PASSCRED:
645 		if (valbool)
646 			set_bit(SOCK_PASSCRED, &sock->flags);
647 		else
648 			clear_bit(SOCK_PASSCRED, &sock->flags);
649 		break;
650 
651 	case SO_TIMESTAMP:
652 	case SO_TIMESTAMPNS:
653 		if (valbool)  {
654 			if (optname == SO_TIMESTAMP)
655 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
656 			else
657 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
658 			sock_set_flag(sk, SOCK_RCVTSTAMP);
659 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
660 		} else {
661 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
662 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
663 		}
664 		break;
665 
666 	case SO_TIMESTAMPING:
667 		if (val & ~SOF_TIMESTAMPING_MASK) {
668 			ret = -EINVAL;
669 			break;
670 		}
671 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
672 				  val & SOF_TIMESTAMPING_TX_HARDWARE);
673 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
674 				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
675 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
676 				  val & SOF_TIMESTAMPING_RX_HARDWARE);
677 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
678 			sock_enable_timestamp(sk,
679 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
680 		else
681 			sock_disable_timestamp(sk,
682 					       SOCK_TIMESTAMPING_RX_SOFTWARE);
683 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
684 				  val & SOF_TIMESTAMPING_SOFTWARE);
685 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
686 				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
687 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
688 				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
689 		break;
690 
691 	case SO_RCVLOWAT:
692 		if (val < 0)
693 			val = INT_MAX;
694 		sk->sk_rcvlowat = val ? : 1;
695 		break;
696 
697 	case SO_RCVTIMEO:
698 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
699 		break;
700 
701 	case SO_SNDTIMEO:
702 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
703 		break;
704 
705 	case SO_ATTACH_FILTER:
706 		ret = -EINVAL;
707 		if (optlen == sizeof(struct sock_fprog)) {
708 			struct sock_fprog fprog;
709 
710 			ret = -EFAULT;
711 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
712 				break;
713 
714 			ret = sk_attach_filter(&fprog, sk);
715 		}
716 		break;
717 
718 	case SO_DETACH_FILTER:
719 		ret = sk_detach_filter(sk);
720 		break;
721 
722 	case SO_PASSSEC:
723 		if (valbool)
724 			set_bit(SOCK_PASSSEC, &sock->flags);
725 		else
726 			clear_bit(SOCK_PASSSEC, &sock->flags);
727 		break;
728 	case SO_MARK:
729 		if (!capable(CAP_NET_ADMIN))
730 			ret = -EPERM;
731 		else
732 			sk->sk_mark = val;
733 		break;
734 
735 		/* We implement the SO_SNDLOWAT etc to
736 		   not be settable (1003.1g 5.3) */
737 	case SO_RXQ_OVFL:
738 		if (valbool)
739 			sock_set_flag(sk, SOCK_RXQ_OVFL);
740 		else
741 			sock_reset_flag(sk, SOCK_RXQ_OVFL);
742 		break;
743 	default:
744 		ret = -ENOPROTOOPT;
745 		break;
746 	}
747 	release_sock(sk);
748 	return ret;
749 }
750 EXPORT_SYMBOL(sock_setsockopt);
751 
752 
753 void cred_to_ucred(struct pid *pid, const struct cred *cred,
754 		   struct ucred *ucred)
755 {
756 	ucred->pid = pid_vnr(pid);
757 	ucred->uid = ucred->gid = -1;
758 	if (cred) {
759 		struct user_namespace *current_ns = current_user_ns();
760 
761 		ucred->uid = user_ns_map_uid(current_ns, cred, cred->euid);
762 		ucred->gid = user_ns_map_gid(current_ns, cred, cred->egid);
763 	}
764 }
765 EXPORT_SYMBOL_GPL(cred_to_ucred);
766 
767 int sock_getsockopt(struct socket *sock, int level, int optname,
768 		    char __user *optval, int __user *optlen)
769 {
770 	struct sock *sk = sock->sk;
771 
772 	union {
773 		int val;
774 		struct linger ling;
775 		struct timeval tm;
776 	} v;
777 
778 	int lv = sizeof(int);
779 	int len;
780 
781 	if (get_user(len, optlen))
782 		return -EFAULT;
783 	if (len < 0)
784 		return -EINVAL;
785 
786 	memset(&v, 0, sizeof(v));
787 
788 	switch (optname) {
789 	case SO_DEBUG:
790 		v.val = sock_flag(sk, SOCK_DBG);
791 		break;
792 
793 	case SO_DONTROUTE:
794 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
795 		break;
796 
797 	case SO_BROADCAST:
798 		v.val = !!sock_flag(sk, SOCK_BROADCAST);
799 		break;
800 
801 	case SO_SNDBUF:
802 		v.val = sk->sk_sndbuf;
803 		break;
804 
805 	case SO_RCVBUF:
806 		v.val = sk->sk_rcvbuf;
807 		break;
808 
809 	case SO_REUSEADDR:
810 		v.val = sk->sk_reuse;
811 		break;
812 
813 	case SO_KEEPALIVE:
814 		v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
815 		break;
816 
817 	case SO_TYPE:
818 		v.val = sk->sk_type;
819 		break;
820 
821 	case SO_PROTOCOL:
822 		v.val = sk->sk_protocol;
823 		break;
824 
825 	case SO_DOMAIN:
826 		v.val = sk->sk_family;
827 		break;
828 
829 	case SO_ERROR:
830 		v.val = -sock_error(sk);
831 		if (v.val == 0)
832 			v.val = xchg(&sk->sk_err_soft, 0);
833 		break;
834 
835 	case SO_OOBINLINE:
836 		v.val = !!sock_flag(sk, SOCK_URGINLINE);
837 		break;
838 
839 	case SO_NO_CHECK:
840 		v.val = sk->sk_no_check;
841 		break;
842 
843 	case SO_PRIORITY:
844 		v.val = sk->sk_priority;
845 		break;
846 
847 	case SO_LINGER:
848 		lv		= sizeof(v.ling);
849 		v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
850 		v.ling.l_linger	= sk->sk_lingertime / HZ;
851 		break;
852 
853 	case SO_BSDCOMPAT:
854 		sock_warn_obsolete_bsdism("getsockopt");
855 		break;
856 
857 	case SO_TIMESTAMP:
858 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
859 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
860 		break;
861 
862 	case SO_TIMESTAMPNS:
863 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
864 		break;
865 
866 	case SO_TIMESTAMPING:
867 		v.val = 0;
868 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
869 			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
870 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
871 			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
872 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
873 			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
874 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
875 			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
876 		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
877 			v.val |= SOF_TIMESTAMPING_SOFTWARE;
878 		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
879 			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
880 		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
881 			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
882 		break;
883 
884 	case SO_RCVTIMEO:
885 		lv = sizeof(struct timeval);
886 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
887 			v.tm.tv_sec = 0;
888 			v.tm.tv_usec = 0;
889 		} else {
890 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
891 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
892 		}
893 		break;
894 
895 	case SO_SNDTIMEO:
896 		lv = sizeof(struct timeval);
897 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
898 			v.tm.tv_sec = 0;
899 			v.tm.tv_usec = 0;
900 		} else {
901 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
902 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
903 		}
904 		break;
905 
906 	case SO_RCVLOWAT:
907 		v.val = sk->sk_rcvlowat;
908 		break;
909 
910 	case SO_SNDLOWAT:
911 		v.val = 1;
912 		break;
913 
914 	case SO_PASSCRED:
915 		v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
916 		break;
917 
918 	case SO_PEERCRED:
919 	{
920 		struct ucred peercred;
921 		if (len > sizeof(peercred))
922 			len = sizeof(peercred);
923 		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
924 		if (copy_to_user(optval, &peercred, len))
925 			return -EFAULT;
926 		goto lenout;
927 	}
928 
929 	case SO_PEERNAME:
930 	{
931 		char address[128];
932 
933 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
934 			return -ENOTCONN;
935 		if (lv < len)
936 			return -EINVAL;
937 		if (copy_to_user(optval, address, len))
938 			return -EFAULT;
939 		goto lenout;
940 	}
941 
942 	/* Dubious BSD thing... Probably nobody even uses it, but
943 	 * the UNIX standard wants it for whatever reason... -DaveM
944 	 */
945 	case SO_ACCEPTCONN:
946 		v.val = sk->sk_state == TCP_LISTEN;
947 		break;
948 
949 	case SO_PASSSEC:
950 		v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
951 		break;
952 
953 	case SO_PEERSEC:
954 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
955 
956 	case SO_MARK:
957 		v.val = sk->sk_mark;
958 		break;
959 
960 	case SO_RXQ_OVFL:
961 		v.val = !!sock_flag(sk, SOCK_RXQ_OVFL);
962 		break;
963 
964 	default:
965 		return -ENOPROTOOPT;
966 	}
967 
968 	if (len > lv)
969 		len = lv;
970 	if (copy_to_user(optval, &v, len))
971 		return -EFAULT;
972 lenout:
973 	if (put_user(len, optlen))
974 		return -EFAULT;
975 	return 0;
976 }
977 
978 /*
979  * Initialize an sk_lock.
980  *
981  * (We also register the sk_lock with the lock validator.)
982  */
983 static inline void sock_lock_init(struct sock *sk)
984 {
985 	sock_lock_init_class_and_name(sk,
986 			af_family_slock_key_strings[sk->sk_family],
987 			af_family_slock_keys + sk->sk_family,
988 			af_family_key_strings[sk->sk_family],
989 			af_family_keys + sk->sk_family);
990 }
991 
992 /*
993  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
994  * even temporarly, because of RCU lookups. sk_node should also be left as is.
995  * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
996  */
997 static void sock_copy(struct sock *nsk, const struct sock *osk)
998 {
999 #ifdef CONFIG_SECURITY_NETWORK
1000 	void *sptr = nsk->sk_security;
1001 #endif
1002 	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
1003 
1004 	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
1005 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
1006 
1007 #ifdef CONFIG_SECURITY_NETWORK
1008 	nsk->sk_security = sptr;
1009 	security_sk_clone(osk, nsk);
1010 #endif
1011 }
1012 
1013 /*
1014  * caches using SLAB_DESTROY_BY_RCU should let .next pointer from nulls nodes
1015  * un-modified. Special care is taken when initializing object to zero.
1016  */
1017 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
1018 {
1019 	if (offsetof(struct sock, sk_node.next) != 0)
1020 		memset(sk, 0, offsetof(struct sock, sk_node.next));
1021 	memset(&sk->sk_node.pprev, 0,
1022 	       size - offsetof(struct sock, sk_node.pprev));
1023 }
1024 
1025 void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
1026 {
1027 	unsigned long nulls1, nulls2;
1028 
1029 	nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
1030 	nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
1031 	if (nulls1 > nulls2)
1032 		swap(nulls1, nulls2);
1033 
1034 	if (nulls1 != 0)
1035 		memset((char *)sk, 0, nulls1);
1036 	memset((char *)sk + nulls1 + sizeof(void *), 0,
1037 	       nulls2 - nulls1 - sizeof(void *));
1038 	memset((char *)sk + nulls2 + sizeof(void *), 0,
1039 	       size - nulls2 - sizeof(void *));
1040 }
1041 EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
1042 
1043 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
1044 		int family)
1045 {
1046 	struct sock *sk;
1047 	struct kmem_cache *slab;
1048 
1049 	slab = prot->slab;
1050 	if (slab != NULL) {
1051 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
1052 		if (!sk)
1053 			return sk;
1054 		if (priority & __GFP_ZERO) {
1055 			if (prot->clear_sk)
1056 				prot->clear_sk(sk, prot->obj_size);
1057 			else
1058 				sk_prot_clear_nulls(sk, prot->obj_size);
1059 		}
1060 	} else
1061 		sk = kmalloc(prot->obj_size, priority);
1062 
1063 	if (sk != NULL) {
1064 		kmemcheck_annotate_bitfield(sk, flags);
1065 
1066 		if (security_sk_alloc(sk, family, priority))
1067 			goto out_free;
1068 
1069 		if (!try_module_get(prot->owner))
1070 			goto out_free_sec;
1071 		sk_tx_queue_clear(sk);
1072 	}
1073 
1074 	return sk;
1075 
1076 out_free_sec:
1077 	security_sk_free(sk);
1078 out_free:
1079 	if (slab != NULL)
1080 		kmem_cache_free(slab, sk);
1081 	else
1082 		kfree(sk);
1083 	return NULL;
1084 }
1085 
1086 static void sk_prot_free(struct proto *prot, struct sock *sk)
1087 {
1088 	struct kmem_cache *slab;
1089 	struct module *owner;
1090 
1091 	owner = prot->owner;
1092 	slab = prot->slab;
1093 
1094 	security_sk_free(sk);
1095 	if (slab != NULL)
1096 		kmem_cache_free(slab, sk);
1097 	else
1098 		kfree(sk);
1099 	module_put(owner);
1100 }
1101 
1102 #ifdef CONFIG_CGROUPS
1103 void sock_update_classid(struct sock *sk)
1104 {
1105 	u32 classid;
1106 
1107 	rcu_read_lock();  /* doing current task, which cannot vanish. */
1108 	classid = task_cls_classid(current);
1109 	rcu_read_unlock();
1110 	if (classid && classid != sk->sk_classid)
1111 		sk->sk_classid = classid;
1112 }
1113 EXPORT_SYMBOL(sock_update_classid);
1114 #endif
1115 
1116 /**
1117  *	sk_alloc - All socket objects are allocated here
1118  *	@net: the applicable net namespace
1119  *	@family: protocol family
1120  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1121  *	@prot: struct proto associated with this new sock instance
1122  */
1123 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1124 		      struct proto *prot)
1125 {
1126 	struct sock *sk;
1127 
1128 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1129 	if (sk) {
1130 		sk->sk_family = family;
1131 		/*
1132 		 * See comment in struct sock definition to understand
1133 		 * why we need sk_prot_creator -acme
1134 		 */
1135 		sk->sk_prot = sk->sk_prot_creator = prot;
1136 		sock_lock_init(sk);
1137 		sock_net_set(sk, get_net(net));
1138 		atomic_set(&sk->sk_wmem_alloc, 1);
1139 
1140 		sock_update_classid(sk);
1141 	}
1142 
1143 	return sk;
1144 }
1145 EXPORT_SYMBOL(sk_alloc);
1146 
1147 static void __sk_free(struct sock *sk)
1148 {
1149 	struct sk_filter *filter;
1150 
1151 	if (sk->sk_destruct)
1152 		sk->sk_destruct(sk);
1153 
1154 	filter = rcu_dereference_check(sk->sk_filter,
1155 				       atomic_read(&sk->sk_wmem_alloc) == 0);
1156 	if (filter) {
1157 		sk_filter_uncharge(sk, filter);
1158 		rcu_assign_pointer(sk->sk_filter, NULL);
1159 	}
1160 
1161 	sock_disable_timestamp(sk, SOCK_TIMESTAMP);
1162 	sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
1163 
1164 	if (atomic_read(&sk->sk_omem_alloc))
1165 		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
1166 		       __func__, atomic_read(&sk->sk_omem_alloc));
1167 
1168 	if (sk->sk_peer_cred)
1169 		put_cred(sk->sk_peer_cred);
1170 	put_pid(sk->sk_peer_pid);
1171 	put_net(sock_net(sk));
1172 	sk_prot_free(sk->sk_prot_creator, sk);
1173 }
1174 
1175 void sk_free(struct sock *sk)
1176 {
1177 	/*
1178 	 * We subtract one from sk_wmem_alloc and can know if
1179 	 * some packets are still in some tx queue.
1180 	 * If not null, sock_wfree() will call __sk_free(sk) later
1181 	 */
1182 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1183 		__sk_free(sk);
1184 }
1185 EXPORT_SYMBOL(sk_free);
1186 
1187 /*
1188  * Last sock_put should drop reference to sk->sk_net. It has already
1189  * been dropped in sk_change_net. Taking reference to stopping namespace
1190  * is not an option.
1191  * Take reference to a socket to remove it from hash _alive_ and after that
1192  * destroy it in the context of init_net.
1193  */
1194 void sk_release_kernel(struct sock *sk)
1195 {
1196 	if (sk == NULL || sk->sk_socket == NULL)
1197 		return;
1198 
1199 	sock_hold(sk);
1200 	sock_release(sk->sk_socket);
1201 	release_net(sock_net(sk));
1202 	sock_net_set(sk, get_net(&init_net));
1203 	sock_put(sk);
1204 }
1205 EXPORT_SYMBOL(sk_release_kernel);
1206 
1207 struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1208 {
1209 	struct sock *newsk;
1210 
1211 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1212 	if (newsk != NULL) {
1213 		struct sk_filter *filter;
1214 
1215 		sock_copy(newsk, sk);
1216 
1217 		/* SANITY */
1218 		get_net(sock_net(newsk));
1219 		sk_node_init(&newsk->sk_node);
1220 		sock_lock_init(newsk);
1221 		bh_lock_sock(newsk);
1222 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1223 		newsk->sk_backlog.len = 0;
1224 
1225 		atomic_set(&newsk->sk_rmem_alloc, 0);
1226 		/*
1227 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1228 		 */
1229 		atomic_set(&newsk->sk_wmem_alloc, 1);
1230 		atomic_set(&newsk->sk_omem_alloc, 0);
1231 		skb_queue_head_init(&newsk->sk_receive_queue);
1232 		skb_queue_head_init(&newsk->sk_write_queue);
1233 #ifdef CONFIG_NET_DMA
1234 		skb_queue_head_init(&newsk->sk_async_wait_queue);
1235 #endif
1236 
1237 		spin_lock_init(&newsk->sk_dst_lock);
1238 		rwlock_init(&newsk->sk_callback_lock);
1239 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1240 				af_callback_keys + newsk->sk_family,
1241 				af_family_clock_key_strings[newsk->sk_family]);
1242 
1243 		newsk->sk_dst_cache	= NULL;
1244 		newsk->sk_wmem_queued	= 0;
1245 		newsk->sk_forward_alloc = 0;
1246 		newsk->sk_send_head	= NULL;
1247 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1248 
1249 		sock_reset_flag(newsk, SOCK_DONE);
1250 		skb_queue_head_init(&newsk->sk_error_queue);
1251 
1252 		filter = rcu_dereference_protected(newsk->sk_filter, 1);
1253 		if (filter != NULL)
1254 			sk_filter_charge(newsk, filter);
1255 
1256 		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1257 			/* It is still raw copy of parent, so invalidate
1258 			 * destructor and make plain sk_free() */
1259 			newsk->sk_destruct = NULL;
1260 			sk_free(newsk);
1261 			newsk = NULL;
1262 			goto out;
1263 		}
1264 
1265 		newsk->sk_err	   = 0;
1266 		newsk->sk_priority = 0;
1267 		/*
1268 		 * Before updating sk_refcnt, we must commit prior changes to memory
1269 		 * (Documentation/RCU/rculist_nulls.txt for details)
1270 		 */
1271 		smp_wmb();
1272 		atomic_set(&newsk->sk_refcnt, 2);
1273 
1274 		/*
1275 		 * Increment the counter in the same struct proto as the master
1276 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1277 		 * is the same as sk->sk_prot->socks, as this field was copied
1278 		 * with memcpy).
1279 		 *
1280 		 * This _changes_ the previous behaviour, where
1281 		 * tcp_create_openreq_child always was incrementing the
1282 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1283 		 * to be taken into account in all callers. -acme
1284 		 */
1285 		sk_refcnt_debug_inc(newsk);
1286 		sk_set_socket(newsk, NULL);
1287 		newsk->sk_wq = NULL;
1288 
1289 		if (newsk->sk_prot->sockets_allocated)
1290 			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1291 
1292 		if (sock_flag(newsk, SOCK_TIMESTAMP) ||
1293 		    sock_flag(newsk, SOCK_TIMESTAMPING_RX_SOFTWARE))
1294 			net_enable_timestamp();
1295 	}
1296 out:
1297 	return newsk;
1298 }
1299 EXPORT_SYMBOL_GPL(sk_clone);
1300 
1301 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1302 {
1303 	__sk_dst_set(sk, dst);
1304 	sk->sk_route_caps = dst->dev->features;
1305 	if (sk->sk_route_caps & NETIF_F_GSO)
1306 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1307 	sk->sk_route_caps &= ~sk->sk_route_nocaps;
1308 	if (sk_can_gso(sk)) {
1309 		if (dst->header_len) {
1310 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1311 		} else {
1312 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1313 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1314 		}
1315 	}
1316 }
1317 EXPORT_SYMBOL_GPL(sk_setup_caps);
1318 
1319 void __init sk_init(void)
1320 {
1321 	if (totalram_pages <= 4096) {
1322 		sysctl_wmem_max = 32767;
1323 		sysctl_rmem_max = 32767;
1324 		sysctl_wmem_default = 32767;
1325 		sysctl_rmem_default = 32767;
1326 	} else if (totalram_pages >= 131072) {
1327 		sysctl_wmem_max = 131071;
1328 		sysctl_rmem_max = 131071;
1329 	}
1330 }
1331 
1332 /*
1333  *	Simple resource managers for sockets.
1334  */
1335 
1336 
1337 /*
1338  * Write buffer destructor automatically called from kfree_skb.
1339  */
1340 void sock_wfree(struct sk_buff *skb)
1341 {
1342 	struct sock *sk = skb->sk;
1343 	unsigned int len = skb->truesize;
1344 
1345 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1346 		/*
1347 		 * Keep a reference on sk_wmem_alloc, this will be released
1348 		 * after sk_write_space() call
1349 		 */
1350 		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1351 		sk->sk_write_space(sk);
1352 		len = 1;
1353 	}
1354 	/*
1355 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1356 	 * could not do because of in-flight packets
1357 	 */
1358 	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1359 		__sk_free(sk);
1360 }
1361 EXPORT_SYMBOL(sock_wfree);
1362 
1363 /*
1364  * Read buffer destructor automatically called from kfree_skb.
1365  */
1366 void sock_rfree(struct sk_buff *skb)
1367 {
1368 	struct sock *sk = skb->sk;
1369 	unsigned int len = skb->truesize;
1370 
1371 	atomic_sub(len, &sk->sk_rmem_alloc);
1372 	sk_mem_uncharge(sk, len);
1373 }
1374 EXPORT_SYMBOL(sock_rfree);
1375 
1376 
1377 int sock_i_uid(struct sock *sk)
1378 {
1379 	int uid;
1380 
1381 	read_lock_bh(&sk->sk_callback_lock);
1382 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1383 	read_unlock_bh(&sk->sk_callback_lock);
1384 	return uid;
1385 }
1386 EXPORT_SYMBOL(sock_i_uid);
1387 
1388 unsigned long sock_i_ino(struct sock *sk)
1389 {
1390 	unsigned long ino;
1391 
1392 	read_lock_bh(&sk->sk_callback_lock);
1393 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1394 	read_unlock_bh(&sk->sk_callback_lock);
1395 	return ino;
1396 }
1397 EXPORT_SYMBOL(sock_i_ino);
1398 
1399 /*
1400  * Allocate a skb from the socket's send buffer.
1401  */
1402 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1403 			     gfp_t priority)
1404 {
1405 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1406 		struct sk_buff *skb = alloc_skb(size, priority);
1407 		if (skb) {
1408 			skb_set_owner_w(skb, sk);
1409 			return skb;
1410 		}
1411 	}
1412 	return NULL;
1413 }
1414 EXPORT_SYMBOL(sock_wmalloc);
1415 
1416 /*
1417  * Allocate a skb from the socket's receive buffer.
1418  */
1419 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1420 			     gfp_t priority)
1421 {
1422 	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1423 		struct sk_buff *skb = alloc_skb(size, priority);
1424 		if (skb) {
1425 			skb_set_owner_r(skb, sk);
1426 			return skb;
1427 		}
1428 	}
1429 	return NULL;
1430 }
1431 
1432 /*
1433  * Allocate a memory block from the socket's option memory buffer.
1434  */
1435 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1436 {
1437 	if ((unsigned)size <= sysctl_optmem_max &&
1438 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1439 		void *mem;
1440 		/* First do the add, to avoid the race if kmalloc
1441 		 * might sleep.
1442 		 */
1443 		atomic_add(size, &sk->sk_omem_alloc);
1444 		mem = kmalloc(size, priority);
1445 		if (mem)
1446 			return mem;
1447 		atomic_sub(size, &sk->sk_omem_alloc);
1448 	}
1449 	return NULL;
1450 }
1451 EXPORT_SYMBOL(sock_kmalloc);
1452 
1453 /*
1454  * Free an option memory block.
1455  */
1456 void sock_kfree_s(struct sock *sk, void *mem, int size)
1457 {
1458 	kfree(mem);
1459 	atomic_sub(size, &sk->sk_omem_alloc);
1460 }
1461 EXPORT_SYMBOL(sock_kfree_s);
1462 
1463 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1464    I think, these locks should be removed for datagram sockets.
1465  */
1466 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1467 {
1468 	DEFINE_WAIT(wait);
1469 
1470 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1471 	for (;;) {
1472 		if (!timeo)
1473 			break;
1474 		if (signal_pending(current))
1475 			break;
1476 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1477 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1478 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1479 			break;
1480 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1481 			break;
1482 		if (sk->sk_err)
1483 			break;
1484 		timeo = schedule_timeout(timeo);
1485 	}
1486 	finish_wait(sk_sleep(sk), &wait);
1487 	return timeo;
1488 }
1489 
1490 
1491 /*
1492  *	Generic send/receive buffer handlers
1493  */
1494 
1495 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1496 				     unsigned long data_len, int noblock,
1497 				     int *errcode)
1498 {
1499 	struct sk_buff *skb;
1500 	gfp_t gfp_mask;
1501 	long timeo;
1502 	int err;
1503 
1504 	gfp_mask = sk->sk_allocation;
1505 	if (gfp_mask & __GFP_WAIT)
1506 		gfp_mask |= __GFP_REPEAT;
1507 
1508 	timeo = sock_sndtimeo(sk, noblock);
1509 	while (1) {
1510 		err = sock_error(sk);
1511 		if (err != 0)
1512 			goto failure;
1513 
1514 		err = -EPIPE;
1515 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1516 			goto failure;
1517 
1518 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1519 			skb = alloc_skb(header_len, gfp_mask);
1520 			if (skb) {
1521 				int npages;
1522 				int i;
1523 
1524 				/* No pages, we're done... */
1525 				if (!data_len)
1526 					break;
1527 
1528 				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1529 				skb->truesize += data_len;
1530 				skb_shinfo(skb)->nr_frags = npages;
1531 				for (i = 0; i < npages; i++) {
1532 					struct page *page;
1533 					skb_frag_t *frag;
1534 
1535 					page = alloc_pages(sk->sk_allocation, 0);
1536 					if (!page) {
1537 						err = -ENOBUFS;
1538 						skb_shinfo(skb)->nr_frags = i;
1539 						kfree_skb(skb);
1540 						goto failure;
1541 					}
1542 
1543 					frag = &skb_shinfo(skb)->frags[i];
1544 					frag->page = page;
1545 					frag->page_offset = 0;
1546 					frag->size = (data_len >= PAGE_SIZE ?
1547 						      PAGE_SIZE :
1548 						      data_len);
1549 					data_len -= PAGE_SIZE;
1550 				}
1551 
1552 				/* Full success... */
1553 				break;
1554 			}
1555 			err = -ENOBUFS;
1556 			goto failure;
1557 		}
1558 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1559 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1560 		err = -EAGAIN;
1561 		if (!timeo)
1562 			goto failure;
1563 		if (signal_pending(current))
1564 			goto interrupted;
1565 		timeo = sock_wait_for_wmem(sk, timeo);
1566 	}
1567 
1568 	skb_set_owner_w(skb, sk);
1569 	return skb;
1570 
1571 interrupted:
1572 	err = sock_intr_errno(timeo);
1573 failure:
1574 	*errcode = err;
1575 	return NULL;
1576 }
1577 EXPORT_SYMBOL(sock_alloc_send_pskb);
1578 
1579 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1580 				    int noblock, int *errcode)
1581 {
1582 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1583 }
1584 EXPORT_SYMBOL(sock_alloc_send_skb);
1585 
1586 static void __lock_sock(struct sock *sk)
1587 	__releases(&sk->sk_lock.slock)
1588 	__acquires(&sk->sk_lock.slock)
1589 {
1590 	DEFINE_WAIT(wait);
1591 
1592 	for (;;) {
1593 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1594 					TASK_UNINTERRUPTIBLE);
1595 		spin_unlock_bh(&sk->sk_lock.slock);
1596 		schedule();
1597 		spin_lock_bh(&sk->sk_lock.slock);
1598 		if (!sock_owned_by_user(sk))
1599 			break;
1600 	}
1601 	finish_wait(&sk->sk_lock.wq, &wait);
1602 }
1603 
1604 static void __release_sock(struct sock *sk)
1605 	__releases(&sk->sk_lock.slock)
1606 	__acquires(&sk->sk_lock.slock)
1607 {
1608 	struct sk_buff *skb = sk->sk_backlog.head;
1609 
1610 	do {
1611 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1612 		bh_unlock_sock(sk);
1613 
1614 		do {
1615 			struct sk_buff *next = skb->next;
1616 
1617 			WARN_ON_ONCE(skb_dst_is_noref(skb));
1618 			skb->next = NULL;
1619 			sk_backlog_rcv(sk, skb);
1620 
1621 			/*
1622 			 * We are in process context here with softirqs
1623 			 * disabled, use cond_resched_softirq() to preempt.
1624 			 * This is safe to do because we've taken the backlog
1625 			 * queue private:
1626 			 */
1627 			cond_resched_softirq();
1628 
1629 			skb = next;
1630 		} while (skb != NULL);
1631 
1632 		bh_lock_sock(sk);
1633 	} while ((skb = sk->sk_backlog.head) != NULL);
1634 
1635 	/*
1636 	 * Doing the zeroing here guarantee we can not loop forever
1637 	 * while a wild producer attempts to flood us.
1638 	 */
1639 	sk->sk_backlog.len = 0;
1640 }
1641 
1642 /**
1643  * sk_wait_data - wait for data to arrive at sk_receive_queue
1644  * @sk:    sock to wait on
1645  * @timeo: for how long
1646  *
1647  * Now socket state including sk->sk_err is changed only under lock,
1648  * hence we may omit checks after joining wait queue.
1649  * We check receive queue before schedule() only as optimization;
1650  * it is very likely that release_sock() added new data.
1651  */
1652 int sk_wait_data(struct sock *sk, long *timeo)
1653 {
1654 	int rc;
1655 	DEFINE_WAIT(wait);
1656 
1657 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
1658 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1659 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1660 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1661 	finish_wait(sk_sleep(sk), &wait);
1662 	return rc;
1663 }
1664 EXPORT_SYMBOL(sk_wait_data);
1665 
1666 /**
1667  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1668  *	@sk: socket
1669  *	@size: memory size to allocate
1670  *	@kind: allocation type
1671  *
1672  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1673  *	rmem allocation. This function assumes that protocols which have
1674  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1675  */
1676 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1677 {
1678 	struct proto *prot = sk->sk_prot;
1679 	int amt = sk_mem_pages(size);
1680 	long allocated;
1681 
1682 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1683 	allocated = atomic_long_add_return(amt, prot->memory_allocated);
1684 
1685 	/* Under limit. */
1686 	if (allocated <= prot->sysctl_mem[0]) {
1687 		if (prot->memory_pressure && *prot->memory_pressure)
1688 			*prot->memory_pressure = 0;
1689 		return 1;
1690 	}
1691 
1692 	/* Under pressure. */
1693 	if (allocated > prot->sysctl_mem[1])
1694 		if (prot->enter_memory_pressure)
1695 			prot->enter_memory_pressure(sk);
1696 
1697 	/* Over hard limit. */
1698 	if (allocated > prot->sysctl_mem[2])
1699 		goto suppress_allocation;
1700 
1701 	/* guarantee minimum buffer size under pressure */
1702 	if (kind == SK_MEM_RECV) {
1703 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1704 			return 1;
1705 	} else { /* SK_MEM_SEND */
1706 		if (sk->sk_type == SOCK_STREAM) {
1707 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1708 				return 1;
1709 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1710 			   prot->sysctl_wmem[0])
1711 				return 1;
1712 	}
1713 
1714 	if (prot->memory_pressure) {
1715 		int alloc;
1716 
1717 		if (!*prot->memory_pressure)
1718 			return 1;
1719 		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1720 		if (prot->sysctl_mem[2] > alloc *
1721 		    sk_mem_pages(sk->sk_wmem_queued +
1722 				 atomic_read(&sk->sk_rmem_alloc) +
1723 				 sk->sk_forward_alloc))
1724 			return 1;
1725 	}
1726 
1727 suppress_allocation:
1728 
1729 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1730 		sk_stream_moderate_sndbuf(sk);
1731 
1732 		/* Fail only if socket is _under_ its sndbuf.
1733 		 * In this case we cannot block, so that we have to fail.
1734 		 */
1735 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1736 			return 1;
1737 	}
1738 
1739 	/* Alas. Undo changes. */
1740 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1741 	atomic_long_sub(amt, prot->memory_allocated);
1742 	return 0;
1743 }
1744 EXPORT_SYMBOL(__sk_mem_schedule);
1745 
1746 /**
1747  *	__sk_reclaim - reclaim memory_allocated
1748  *	@sk: socket
1749  */
1750 void __sk_mem_reclaim(struct sock *sk)
1751 {
1752 	struct proto *prot = sk->sk_prot;
1753 
1754 	atomic_long_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1755 		   prot->memory_allocated);
1756 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1757 
1758 	if (prot->memory_pressure && *prot->memory_pressure &&
1759 	    (atomic_long_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1760 		*prot->memory_pressure = 0;
1761 }
1762 EXPORT_SYMBOL(__sk_mem_reclaim);
1763 
1764 
1765 /*
1766  * Set of default routines for initialising struct proto_ops when
1767  * the protocol does not support a particular function. In certain
1768  * cases where it makes no sense for a protocol to have a "do nothing"
1769  * function, some default processing is provided.
1770  */
1771 
1772 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1773 {
1774 	return -EOPNOTSUPP;
1775 }
1776 EXPORT_SYMBOL(sock_no_bind);
1777 
1778 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1779 		    int len, int flags)
1780 {
1781 	return -EOPNOTSUPP;
1782 }
1783 EXPORT_SYMBOL(sock_no_connect);
1784 
1785 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1786 {
1787 	return -EOPNOTSUPP;
1788 }
1789 EXPORT_SYMBOL(sock_no_socketpair);
1790 
1791 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1792 {
1793 	return -EOPNOTSUPP;
1794 }
1795 EXPORT_SYMBOL(sock_no_accept);
1796 
1797 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1798 		    int *len, int peer)
1799 {
1800 	return -EOPNOTSUPP;
1801 }
1802 EXPORT_SYMBOL(sock_no_getname);
1803 
1804 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1805 {
1806 	return 0;
1807 }
1808 EXPORT_SYMBOL(sock_no_poll);
1809 
1810 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1811 {
1812 	return -EOPNOTSUPP;
1813 }
1814 EXPORT_SYMBOL(sock_no_ioctl);
1815 
1816 int sock_no_listen(struct socket *sock, int backlog)
1817 {
1818 	return -EOPNOTSUPP;
1819 }
1820 EXPORT_SYMBOL(sock_no_listen);
1821 
1822 int sock_no_shutdown(struct socket *sock, int how)
1823 {
1824 	return -EOPNOTSUPP;
1825 }
1826 EXPORT_SYMBOL(sock_no_shutdown);
1827 
1828 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1829 		    char __user *optval, unsigned int optlen)
1830 {
1831 	return -EOPNOTSUPP;
1832 }
1833 EXPORT_SYMBOL(sock_no_setsockopt);
1834 
1835 int sock_no_getsockopt(struct socket *sock, int level, int optname,
1836 		    char __user *optval, int __user *optlen)
1837 {
1838 	return -EOPNOTSUPP;
1839 }
1840 EXPORT_SYMBOL(sock_no_getsockopt);
1841 
1842 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1843 		    size_t len)
1844 {
1845 	return -EOPNOTSUPP;
1846 }
1847 EXPORT_SYMBOL(sock_no_sendmsg);
1848 
1849 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1850 		    size_t len, int flags)
1851 {
1852 	return -EOPNOTSUPP;
1853 }
1854 EXPORT_SYMBOL(sock_no_recvmsg);
1855 
1856 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1857 {
1858 	/* Mirror missing mmap method error code */
1859 	return -ENODEV;
1860 }
1861 EXPORT_SYMBOL(sock_no_mmap);
1862 
1863 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1864 {
1865 	ssize_t res;
1866 	struct msghdr msg = {.msg_flags = flags};
1867 	struct kvec iov;
1868 	char *kaddr = kmap(page);
1869 	iov.iov_base = kaddr + offset;
1870 	iov.iov_len = size;
1871 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1872 	kunmap(page);
1873 	return res;
1874 }
1875 EXPORT_SYMBOL(sock_no_sendpage);
1876 
1877 /*
1878  *	Default Socket Callbacks
1879  */
1880 
1881 static void sock_def_wakeup(struct sock *sk)
1882 {
1883 	struct socket_wq *wq;
1884 
1885 	rcu_read_lock();
1886 	wq = rcu_dereference(sk->sk_wq);
1887 	if (wq_has_sleeper(wq))
1888 		wake_up_interruptible_all(&wq->wait);
1889 	rcu_read_unlock();
1890 }
1891 
1892 static void sock_def_error_report(struct sock *sk)
1893 {
1894 	struct socket_wq *wq;
1895 
1896 	rcu_read_lock();
1897 	wq = rcu_dereference(sk->sk_wq);
1898 	if (wq_has_sleeper(wq))
1899 		wake_up_interruptible_poll(&wq->wait, POLLERR);
1900 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1901 	rcu_read_unlock();
1902 }
1903 
1904 static void sock_def_readable(struct sock *sk, int len)
1905 {
1906 	struct socket_wq *wq;
1907 
1908 	rcu_read_lock();
1909 	wq = rcu_dereference(sk->sk_wq);
1910 	if (wq_has_sleeper(wq))
1911 		wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
1912 						POLLRDNORM | POLLRDBAND);
1913 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1914 	rcu_read_unlock();
1915 }
1916 
1917 static void sock_def_write_space(struct sock *sk)
1918 {
1919 	struct socket_wq *wq;
1920 
1921 	rcu_read_lock();
1922 
1923 	/* Do not wake up a writer until he can make "significant"
1924 	 * progress.  --DaveM
1925 	 */
1926 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1927 		wq = rcu_dereference(sk->sk_wq);
1928 		if (wq_has_sleeper(wq))
1929 			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
1930 						POLLWRNORM | POLLWRBAND);
1931 
1932 		/* Should agree with poll, otherwise some programs break */
1933 		if (sock_writeable(sk))
1934 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1935 	}
1936 
1937 	rcu_read_unlock();
1938 }
1939 
1940 static void sock_def_destruct(struct sock *sk)
1941 {
1942 	kfree(sk->sk_protinfo);
1943 }
1944 
1945 void sk_send_sigurg(struct sock *sk)
1946 {
1947 	if (sk->sk_socket && sk->sk_socket->file)
1948 		if (send_sigurg(&sk->sk_socket->file->f_owner))
1949 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1950 }
1951 EXPORT_SYMBOL(sk_send_sigurg);
1952 
1953 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1954 		    unsigned long expires)
1955 {
1956 	if (!mod_timer(timer, expires))
1957 		sock_hold(sk);
1958 }
1959 EXPORT_SYMBOL(sk_reset_timer);
1960 
1961 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1962 {
1963 	if (timer_pending(timer) && del_timer(timer))
1964 		__sock_put(sk);
1965 }
1966 EXPORT_SYMBOL(sk_stop_timer);
1967 
1968 void sock_init_data(struct socket *sock, struct sock *sk)
1969 {
1970 	skb_queue_head_init(&sk->sk_receive_queue);
1971 	skb_queue_head_init(&sk->sk_write_queue);
1972 	skb_queue_head_init(&sk->sk_error_queue);
1973 #ifdef CONFIG_NET_DMA
1974 	skb_queue_head_init(&sk->sk_async_wait_queue);
1975 #endif
1976 
1977 	sk->sk_send_head	=	NULL;
1978 
1979 	init_timer(&sk->sk_timer);
1980 
1981 	sk->sk_allocation	=	GFP_KERNEL;
1982 	sk->sk_rcvbuf		=	sysctl_rmem_default;
1983 	sk->sk_sndbuf		=	sysctl_wmem_default;
1984 	sk->sk_state		=	TCP_CLOSE;
1985 	sk_set_socket(sk, sock);
1986 
1987 	sock_set_flag(sk, SOCK_ZAPPED);
1988 
1989 	if (sock) {
1990 		sk->sk_type	=	sock->type;
1991 		sk->sk_wq	=	sock->wq;
1992 		sock->sk	=	sk;
1993 	} else
1994 		sk->sk_wq	=	NULL;
1995 
1996 	spin_lock_init(&sk->sk_dst_lock);
1997 	rwlock_init(&sk->sk_callback_lock);
1998 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1999 			af_callback_keys + sk->sk_family,
2000 			af_family_clock_key_strings[sk->sk_family]);
2001 
2002 	sk->sk_state_change	=	sock_def_wakeup;
2003 	sk->sk_data_ready	=	sock_def_readable;
2004 	sk->sk_write_space	=	sock_def_write_space;
2005 	sk->sk_error_report	=	sock_def_error_report;
2006 	sk->sk_destruct		=	sock_def_destruct;
2007 
2008 	sk->sk_sndmsg_page	=	NULL;
2009 	sk->sk_sndmsg_off	=	0;
2010 
2011 	sk->sk_peer_pid 	=	NULL;
2012 	sk->sk_peer_cred	=	NULL;
2013 	sk->sk_write_pending	=	0;
2014 	sk->sk_rcvlowat		=	1;
2015 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
2016 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
2017 
2018 	sk->sk_stamp = ktime_set(-1L, 0);
2019 
2020 	/*
2021 	 * Before updating sk_refcnt, we must commit prior changes to memory
2022 	 * (Documentation/RCU/rculist_nulls.txt for details)
2023 	 */
2024 	smp_wmb();
2025 	atomic_set(&sk->sk_refcnt, 1);
2026 	atomic_set(&sk->sk_drops, 0);
2027 }
2028 EXPORT_SYMBOL(sock_init_data);
2029 
2030 void lock_sock_nested(struct sock *sk, int subclass)
2031 {
2032 	might_sleep();
2033 	spin_lock_bh(&sk->sk_lock.slock);
2034 	if (sk->sk_lock.owned)
2035 		__lock_sock(sk);
2036 	sk->sk_lock.owned = 1;
2037 	spin_unlock(&sk->sk_lock.slock);
2038 	/*
2039 	 * The sk_lock has mutex_lock() semantics here:
2040 	 */
2041 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
2042 	local_bh_enable();
2043 }
2044 EXPORT_SYMBOL(lock_sock_nested);
2045 
2046 void release_sock(struct sock *sk)
2047 {
2048 	/*
2049 	 * The sk_lock has mutex_unlock() semantics:
2050 	 */
2051 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
2052 
2053 	spin_lock_bh(&sk->sk_lock.slock);
2054 	if (sk->sk_backlog.tail)
2055 		__release_sock(sk);
2056 	sk->sk_lock.owned = 0;
2057 	if (waitqueue_active(&sk->sk_lock.wq))
2058 		wake_up(&sk->sk_lock.wq);
2059 	spin_unlock_bh(&sk->sk_lock.slock);
2060 }
2061 EXPORT_SYMBOL(release_sock);
2062 
2063 /**
2064  * lock_sock_fast - fast version of lock_sock
2065  * @sk: socket
2066  *
2067  * This version should be used for very small section, where process wont block
2068  * return false if fast path is taken
2069  *   sk_lock.slock locked, owned = 0, BH disabled
2070  * return true if slow path is taken
2071  *   sk_lock.slock unlocked, owned = 1, BH enabled
2072  */
2073 bool lock_sock_fast(struct sock *sk)
2074 {
2075 	might_sleep();
2076 	spin_lock_bh(&sk->sk_lock.slock);
2077 
2078 	if (!sk->sk_lock.owned)
2079 		/*
2080 		 * Note : We must disable BH
2081 		 */
2082 		return false;
2083 
2084 	__lock_sock(sk);
2085 	sk->sk_lock.owned = 1;
2086 	spin_unlock(&sk->sk_lock.slock);
2087 	/*
2088 	 * The sk_lock has mutex_lock() semantics here:
2089 	 */
2090 	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
2091 	local_bh_enable();
2092 	return true;
2093 }
2094 EXPORT_SYMBOL(lock_sock_fast);
2095 
2096 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
2097 {
2098 	struct timeval tv;
2099 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2100 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2101 	tv = ktime_to_timeval(sk->sk_stamp);
2102 	if (tv.tv_sec == -1)
2103 		return -ENOENT;
2104 	if (tv.tv_sec == 0) {
2105 		sk->sk_stamp = ktime_get_real();
2106 		tv = ktime_to_timeval(sk->sk_stamp);
2107 	}
2108 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
2109 }
2110 EXPORT_SYMBOL(sock_get_timestamp);
2111 
2112 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
2113 {
2114 	struct timespec ts;
2115 	if (!sock_flag(sk, SOCK_TIMESTAMP))
2116 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
2117 	ts = ktime_to_timespec(sk->sk_stamp);
2118 	if (ts.tv_sec == -1)
2119 		return -ENOENT;
2120 	if (ts.tv_sec == 0) {
2121 		sk->sk_stamp = ktime_get_real();
2122 		ts = ktime_to_timespec(sk->sk_stamp);
2123 	}
2124 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
2125 }
2126 EXPORT_SYMBOL(sock_get_timestampns);
2127 
2128 void sock_enable_timestamp(struct sock *sk, int flag)
2129 {
2130 	if (!sock_flag(sk, flag)) {
2131 		sock_set_flag(sk, flag);
2132 		/*
2133 		 * we just set one of the two flags which require net
2134 		 * time stamping, but time stamping might have been on
2135 		 * already because of the other one
2136 		 */
2137 		if (!sock_flag(sk,
2138 				flag == SOCK_TIMESTAMP ?
2139 				SOCK_TIMESTAMPING_RX_SOFTWARE :
2140 				SOCK_TIMESTAMP))
2141 			net_enable_timestamp();
2142 	}
2143 }
2144 
2145 /*
2146  *	Get a socket option on an socket.
2147  *
2148  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2149  *	asynchronous errors should be reported by getsockopt. We assume
2150  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2151  */
2152 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2153 			   char __user *optval, int __user *optlen)
2154 {
2155 	struct sock *sk = sock->sk;
2156 
2157 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2158 }
2159 EXPORT_SYMBOL(sock_common_getsockopt);
2160 
2161 #ifdef CONFIG_COMPAT
2162 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2163 				  char __user *optval, int __user *optlen)
2164 {
2165 	struct sock *sk = sock->sk;
2166 
2167 	if (sk->sk_prot->compat_getsockopt != NULL)
2168 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2169 						      optval, optlen);
2170 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2171 }
2172 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2173 #endif
2174 
2175 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2176 			struct msghdr *msg, size_t size, int flags)
2177 {
2178 	struct sock *sk = sock->sk;
2179 	int addr_len = 0;
2180 	int err;
2181 
2182 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2183 				   flags & ~MSG_DONTWAIT, &addr_len);
2184 	if (err >= 0)
2185 		msg->msg_namelen = addr_len;
2186 	return err;
2187 }
2188 EXPORT_SYMBOL(sock_common_recvmsg);
2189 
2190 /*
2191  *	Set socket options on an inet socket.
2192  */
2193 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2194 			   char __user *optval, unsigned int optlen)
2195 {
2196 	struct sock *sk = sock->sk;
2197 
2198 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2199 }
2200 EXPORT_SYMBOL(sock_common_setsockopt);
2201 
2202 #ifdef CONFIG_COMPAT
2203 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2204 				  char __user *optval, unsigned int optlen)
2205 {
2206 	struct sock *sk = sock->sk;
2207 
2208 	if (sk->sk_prot->compat_setsockopt != NULL)
2209 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2210 						      optval, optlen);
2211 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2212 }
2213 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2214 #endif
2215 
2216 void sk_common_release(struct sock *sk)
2217 {
2218 	if (sk->sk_prot->destroy)
2219 		sk->sk_prot->destroy(sk);
2220 
2221 	/*
2222 	 * Observation: when sock_common_release is called, processes have
2223 	 * no access to socket. But net still has.
2224 	 * Step one, detach it from networking:
2225 	 *
2226 	 * A. Remove from hash tables.
2227 	 */
2228 
2229 	sk->sk_prot->unhash(sk);
2230 
2231 	/*
2232 	 * In this point socket cannot receive new packets, but it is possible
2233 	 * that some packets are in flight because some CPU runs receiver and
2234 	 * did hash table lookup before we unhashed socket. They will achieve
2235 	 * receive queue and will be purged by socket destructor.
2236 	 *
2237 	 * Also we still have packets pending on receive queue and probably,
2238 	 * our own packets waiting in device queues. sock_destroy will drain
2239 	 * receive queue, but transmitted packets will delay socket destruction
2240 	 * until the last reference will be released.
2241 	 */
2242 
2243 	sock_orphan(sk);
2244 
2245 	xfrm_sk_free_policy(sk);
2246 
2247 	sk_refcnt_debug_release(sk);
2248 	sock_put(sk);
2249 }
2250 EXPORT_SYMBOL(sk_common_release);
2251 
2252 static DEFINE_RWLOCK(proto_list_lock);
2253 static LIST_HEAD(proto_list);
2254 
2255 #ifdef CONFIG_PROC_FS
2256 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2257 struct prot_inuse {
2258 	int val[PROTO_INUSE_NR];
2259 };
2260 
2261 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2262 
2263 #ifdef CONFIG_NET_NS
2264 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2265 {
2266 	__this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
2267 }
2268 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2269 
2270 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2271 {
2272 	int cpu, idx = prot->inuse_idx;
2273 	int res = 0;
2274 
2275 	for_each_possible_cpu(cpu)
2276 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2277 
2278 	return res >= 0 ? res : 0;
2279 }
2280 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2281 
2282 static int __net_init sock_inuse_init_net(struct net *net)
2283 {
2284 	net->core.inuse = alloc_percpu(struct prot_inuse);
2285 	return net->core.inuse ? 0 : -ENOMEM;
2286 }
2287 
2288 static void __net_exit sock_inuse_exit_net(struct net *net)
2289 {
2290 	free_percpu(net->core.inuse);
2291 }
2292 
2293 static struct pernet_operations net_inuse_ops = {
2294 	.init = sock_inuse_init_net,
2295 	.exit = sock_inuse_exit_net,
2296 };
2297 
2298 static __init int net_inuse_init(void)
2299 {
2300 	if (register_pernet_subsys(&net_inuse_ops))
2301 		panic("Cannot initialize net inuse counters");
2302 
2303 	return 0;
2304 }
2305 
2306 core_initcall(net_inuse_init);
2307 #else
2308 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2309 
2310 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2311 {
2312 	__this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
2313 }
2314 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2315 
2316 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2317 {
2318 	int cpu, idx = prot->inuse_idx;
2319 	int res = 0;
2320 
2321 	for_each_possible_cpu(cpu)
2322 		res += per_cpu(prot_inuse, cpu).val[idx];
2323 
2324 	return res >= 0 ? res : 0;
2325 }
2326 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2327 #endif
2328 
2329 static void assign_proto_idx(struct proto *prot)
2330 {
2331 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2332 
2333 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2334 		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2335 		return;
2336 	}
2337 
2338 	set_bit(prot->inuse_idx, proto_inuse_idx);
2339 }
2340 
2341 static void release_proto_idx(struct proto *prot)
2342 {
2343 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2344 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2345 }
2346 #else
2347 static inline void assign_proto_idx(struct proto *prot)
2348 {
2349 }
2350 
2351 static inline void release_proto_idx(struct proto *prot)
2352 {
2353 }
2354 #endif
2355 
2356 int proto_register(struct proto *prot, int alloc_slab)
2357 {
2358 	if (alloc_slab) {
2359 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2360 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2361 					NULL);
2362 
2363 		if (prot->slab == NULL) {
2364 			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2365 			       prot->name);
2366 			goto out;
2367 		}
2368 
2369 		if (prot->rsk_prot != NULL) {
2370 			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2371 			if (prot->rsk_prot->slab_name == NULL)
2372 				goto out_free_sock_slab;
2373 
2374 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2375 								 prot->rsk_prot->obj_size, 0,
2376 								 SLAB_HWCACHE_ALIGN, NULL);
2377 
2378 			if (prot->rsk_prot->slab == NULL) {
2379 				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2380 				       prot->name);
2381 				goto out_free_request_sock_slab_name;
2382 			}
2383 		}
2384 
2385 		if (prot->twsk_prot != NULL) {
2386 			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2387 
2388 			if (prot->twsk_prot->twsk_slab_name == NULL)
2389 				goto out_free_request_sock_slab;
2390 
2391 			prot->twsk_prot->twsk_slab =
2392 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2393 						  prot->twsk_prot->twsk_obj_size,
2394 						  0,
2395 						  SLAB_HWCACHE_ALIGN |
2396 							prot->slab_flags,
2397 						  NULL);
2398 			if (prot->twsk_prot->twsk_slab == NULL)
2399 				goto out_free_timewait_sock_slab_name;
2400 		}
2401 	}
2402 
2403 	write_lock(&proto_list_lock);
2404 	list_add(&prot->node, &proto_list);
2405 	assign_proto_idx(prot);
2406 	write_unlock(&proto_list_lock);
2407 	return 0;
2408 
2409 out_free_timewait_sock_slab_name:
2410 	kfree(prot->twsk_prot->twsk_slab_name);
2411 out_free_request_sock_slab:
2412 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2413 		kmem_cache_destroy(prot->rsk_prot->slab);
2414 		prot->rsk_prot->slab = NULL;
2415 	}
2416 out_free_request_sock_slab_name:
2417 	if (prot->rsk_prot)
2418 		kfree(prot->rsk_prot->slab_name);
2419 out_free_sock_slab:
2420 	kmem_cache_destroy(prot->slab);
2421 	prot->slab = NULL;
2422 out:
2423 	return -ENOBUFS;
2424 }
2425 EXPORT_SYMBOL(proto_register);
2426 
2427 void proto_unregister(struct proto *prot)
2428 {
2429 	write_lock(&proto_list_lock);
2430 	release_proto_idx(prot);
2431 	list_del(&prot->node);
2432 	write_unlock(&proto_list_lock);
2433 
2434 	if (prot->slab != NULL) {
2435 		kmem_cache_destroy(prot->slab);
2436 		prot->slab = NULL;
2437 	}
2438 
2439 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2440 		kmem_cache_destroy(prot->rsk_prot->slab);
2441 		kfree(prot->rsk_prot->slab_name);
2442 		prot->rsk_prot->slab = NULL;
2443 	}
2444 
2445 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2446 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2447 		kfree(prot->twsk_prot->twsk_slab_name);
2448 		prot->twsk_prot->twsk_slab = NULL;
2449 	}
2450 }
2451 EXPORT_SYMBOL(proto_unregister);
2452 
2453 #ifdef CONFIG_PROC_FS
2454 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2455 	__acquires(proto_list_lock)
2456 {
2457 	read_lock(&proto_list_lock);
2458 	return seq_list_start_head(&proto_list, *pos);
2459 }
2460 
2461 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2462 {
2463 	return seq_list_next(v, &proto_list, pos);
2464 }
2465 
2466 static void proto_seq_stop(struct seq_file *seq, void *v)
2467 	__releases(proto_list_lock)
2468 {
2469 	read_unlock(&proto_list_lock);
2470 }
2471 
2472 static char proto_method_implemented(const void *method)
2473 {
2474 	return method == NULL ? 'n' : 'y';
2475 }
2476 
2477 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2478 {
2479 	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
2480 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2481 		   proto->name,
2482 		   proto->obj_size,
2483 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2484 		   proto->memory_allocated != NULL ? atomic_long_read(proto->memory_allocated) : -1L,
2485 		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2486 		   proto->max_header,
2487 		   proto->slab == NULL ? "no" : "yes",
2488 		   module_name(proto->owner),
2489 		   proto_method_implemented(proto->close),
2490 		   proto_method_implemented(proto->connect),
2491 		   proto_method_implemented(proto->disconnect),
2492 		   proto_method_implemented(proto->accept),
2493 		   proto_method_implemented(proto->ioctl),
2494 		   proto_method_implemented(proto->init),
2495 		   proto_method_implemented(proto->destroy),
2496 		   proto_method_implemented(proto->shutdown),
2497 		   proto_method_implemented(proto->setsockopt),
2498 		   proto_method_implemented(proto->getsockopt),
2499 		   proto_method_implemented(proto->sendmsg),
2500 		   proto_method_implemented(proto->recvmsg),
2501 		   proto_method_implemented(proto->sendpage),
2502 		   proto_method_implemented(proto->bind),
2503 		   proto_method_implemented(proto->backlog_rcv),
2504 		   proto_method_implemented(proto->hash),
2505 		   proto_method_implemented(proto->unhash),
2506 		   proto_method_implemented(proto->get_port),
2507 		   proto_method_implemented(proto->enter_memory_pressure));
2508 }
2509 
2510 static int proto_seq_show(struct seq_file *seq, void *v)
2511 {
2512 	if (v == &proto_list)
2513 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2514 			   "protocol",
2515 			   "size",
2516 			   "sockets",
2517 			   "memory",
2518 			   "press",
2519 			   "maxhdr",
2520 			   "slab",
2521 			   "module",
2522 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2523 	else
2524 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2525 	return 0;
2526 }
2527 
2528 static const struct seq_operations proto_seq_ops = {
2529 	.start  = proto_seq_start,
2530 	.next   = proto_seq_next,
2531 	.stop   = proto_seq_stop,
2532 	.show   = proto_seq_show,
2533 };
2534 
2535 static int proto_seq_open(struct inode *inode, struct file *file)
2536 {
2537 	return seq_open_net(inode, file, &proto_seq_ops,
2538 			    sizeof(struct seq_net_private));
2539 }
2540 
2541 static const struct file_operations proto_seq_fops = {
2542 	.owner		= THIS_MODULE,
2543 	.open		= proto_seq_open,
2544 	.read		= seq_read,
2545 	.llseek		= seq_lseek,
2546 	.release	= seq_release_net,
2547 };
2548 
2549 static __net_init int proto_init_net(struct net *net)
2550 {
2551 	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2552 		return -ENOMEM;
2553 
2554 	return 0;
2555 }
2556 
2557 static __net_exit void proto_exit_net(struct net *net)
2558 {
2559 	proc_net_remove(net, "protocols");
2560 }
2561 
2562 
2563 static __net_initdata struct pernet_operations proto_net_ops = {
2564 	.init = proto_init_net,
2565 	.exit = proto_exit_net,
2566 };
2567 
2568 static int __init proto_init(void)
2569 {
2570 	return register_pernet_subsys(&proto_net_ops);
2571 }
2572 
2573 subsys_initcall(proto_init);
2574 
2575 #endif /* PROC_FS */
2576