xref: /openbmc/linux/net/core/sock.c (revision a09d2831)
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
344 		sk_add_backlog(sk, skb);
345 	bh_unlock_sock(sk);
346 out:
347 	sock_put(sk);
348 	return rc;
349 discard_and_relse:
350 	kfree_skb(skb);
351 	goto out;
352 }
353 EXPORT_SYMBOL(sk_receive_skb);
354 
355 void sk_reset_txq(struct sock *sk)
356 {
357 	sk_tx_queue_clear(sk);
358 }
359 EXPORT_SYMBOL(sk_reset_txq);
360 
361 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
362 {
363 	struct dst_entry *dst = sk->sk_dst_cache;
364 
365 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
366 		sk_tx_queue_clear(sk);
367 		sk->sk_dst_cache = NULL;
368 		dst_release(dst);
369 		return NULL;
370 	}
371 
372 	return dst;
373 }
374 EXPORT_SYMBOL(__sk_dst_check);
375 
376 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
377 {
378 	struct dst_entry *dst = sk_dst_get(sk);
379 
380 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
381 		sk_dst_reset(sk);
382 		dst_release(dst);
383 		return NULL;
384 	}
385 
386 	return dst;
387 }
388 EXPORT_SYMBOL(sk_dst_check);
389 
390 static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
391 {
392 	int ret = -ENOPROTOOPT;
393 #ifdef CONFIG_NETDEVICES
394 	struct net *net = sock_net(sk);
395 	char devname[IFNAMSIZ];
396 	int index;
397 
398 	/* Sorry... */
399 	ret = -EPERM;
400 	if (!capable(CAP_NET_RAW))
401 		goto out;
402 
403 	ret = -EINVAL;
404 	if (optlen < 0)
405 		goto out;
406 
407 	/* Bind this socket to a particular device like "eth0",
408 	 * as specified in the passed interface name. If the
409 	 * name is "" or the option length is zero the socket
410 	 * is not bound.
411 	 */
412 	if (optlen > IFNAMSIZ - 1)
413 		optlen = IFNAMSIZ - 1;
414 	memset(devname, 0, sizeof(devname));
415 
416 	ret = -EFAULT;
417 	if (copy_from_user(devname, optval, optlen))
418 		goto out;
419 
420 	index = 0;
421 	if (devname[0] != '\0') {
422 		struct net_device *dev;
423 
424 		rcu_read_lock();
425 		dev = dev_get_by_name_rcu(net, devname);
426 		if (dev)
427 			index = dev->ifindex;
428 		rcu_read_unlock();
429 		ret = -ENODEV;
430 		if (!dev)
431 			goto out;
432 	}
433 
434 	lock_sock(sk);
435 	sk->sk_bound_dev_if = index;
436 	sk_dst_reset(sk);
437 	release_sock(sk);
438 
439 	ret = 0;
440 
441 out:
442 #endif
443 
444 	return ret;
445 }
446 
447 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
448 {
449 	if (valbool)
450 		sock_set_flag(sk, bit);
451 	else
452 		sock_reset_flag(sk, bit);
453 }
454 
455 /*
456  *	This is meant for all protocols to use and covers goings on
457  *	at the socket level. Everything here is generic.
458  */
459 
460 int sock_setsockopt(struct socket *sock, int level, int optname,
461 		    char __user *optval, unsigned int optlen)
462 {
463 	struct sock *sk = sock->sk;
464 	int val;
465 	int valbool;
466 	struct linger ling;
467 	int ret = 0;
468 
469 	/*
470 	 *	Options without arguments
471 	 */
472 
473 	if (optname == SO_BINDTODEVICE)
474 		return sock_bindtodevice(sk, optval, optlen);
475 
476 	if (optlen < sizeof(int))
477 		return -EINVAL;
478 
479 	if (get_user(val, (int __user *)optval))
480 		return -EFAULT;
481 
482 	valbool = val ? 1 : 0;
483 
484 	lock_sock(sk);
485 
486 	switch (optname) {
487 	case SO_DEBUG:
488 		if (val && !capable(CAP_NET_ADMIN))
489 			ret = -EACCES;
490 		else
491 			sock_valbool_flag(sk, SOCK_DBG, valbool);
492 		break;
493 	case SO_REUSEADDR:
494 		sk->sk_reuse = valbool;
495 		break;
496 	case SO_TYPE:
497 	case SO_PROTOCOL:
498 	case SO_DOMAIN:
499 	case SO_ERROR:
500 		ret = -ENOPROTOOPT;
501 		break;
502 	case SO_DONTROUTE:
503 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
504 		break;
505 	case SO_BROADCAST:
506 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
507 		break;
508 	case SO_SNDBUF:
509 		/* Don't error on this BSD doesn't and if you think
510 		   about it this is right. Otherwise apps have to
511 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
512 		   are treated in BSD as hints */
513 
514 		if (val > sysctl_wmem_max)
515 			val = sysctl_wmem_max;
516 set_sndbuf:
517 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
518 		if ((val * 2) < SOCK_MIN_SNDBUF)
519 			sk->sk_sndbuf = SOCK_MIN_SNDBUF;
520 		else
521 			sk->sk_sndbuf = val * 2;
522 
523 		/*
524 		 *	Wake up sending tasks if we
525 		 *	upped the value.
526 		 */
527 		sk->sk_write_space(sk);
528 		break;
529 
530 	case SO_SNDBUFFORCE:
531 		if (!capable(CAP_NET_ADMIN)) {
532 			ret = -EPERM;
533 			break;
534 		}
535 		goto set_sndbuf;
536 
537 	case SO_RCVBUF:
538 		/* Don't error on this BSD doesn't and if you think
539 		   about it this is right. Otherwise apps have to
540 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
541 		   are treated in BSD as hints */
542 
543 		if (val > sysctl_rmem_max)
544 			val = sysctl_rmem_max;
545 set_rcvbuf:
546 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
547 		/*
548 		 * We double it on the way in to account for
549 		 * "struct sk_buff" etc. overhead.   Applications
550 		 * assume that the SO_RCVBUF setting they make will
551 		 * allow that much actual data to be received on that
552 		 * socket.
553 		 *
554 		 * Applications are unaware that "struct sk_buff" and
555 		 * other overheads allocate from the receive buffer
556 		 * during socket buffer allocation.
557 		 *
558 		 * And after considering the possible alternatives,
559 		 * returning the value we actually used in getsockopt
560 		 * is the most desirable behavior.
561 		 */
562 		if ((val * 2) < SOCK_MIN_RCVBUF)
563 			sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
564 		else
565 			sk->sk_rcvbuf = val * 2;
566 		break;
567 
568 	case SO_RCVBUFFORCE:
569 		if (!capable(CAP_NET_ADMIN)) {
570 			ret = -EPERM;
571 			break;
572 		}
573 		goto set_rcvbuf;
574 
575 	case SO_KEEPALIVE:
576 #ifdef CONFIG_INET
577 		if (sk->sk_protocol == IPPROTO_TCP)
578 			tcp_set_keepalive(sk, valbool);
579 #endif
580 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
581 		break;
582 
583 	case SO_OOBINLINE:
584 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
585 		break;
586 
587 	case SO_NO_CHECK:
588 		sk->sk_no_check = valbool;
589 		break;
590 
591 	case SO_PRIORITY:
592 		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
593 			sk->sk_priority = val;
594 		else
595 			ret = -EPERM;
596 		break;
597 
598 	case SO_LINGER:
599 		if (optlen < sizeof(ling)) {
600 			ret = -EINVAL;	/* 1003.1g */
601 			break;
602 		}
603 		if (copy_from_user(&ling, optval, sizeof(ling))) {
604 			ret = -EFAULT;
605 			break;
606 		}
607 		if (!ling.l_onoff)
608 			sock_reset_flag(sk, SOCK_LINGER);
609 		else {
610 #if (BITS_PER_LONG == 32)
611 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
612 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
613 			else
614 #endif
615 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
616 			sock_set_flag(sk, SOCK_LINGER);
617 		}
618 		break;
619 
620 	case SO_BSDCOMPAT:
621 		sock_warn_obsolete_bsdism("setsockopt");
622 		break;
623 
624 	case SO_PASSCRED:
625 		if (valbool)
626 			set_bit(SOCK_PASSCRED, &sock->flags);
627 		else
628 			clear_bit(SOCK_PASSCRED, &sock->flags);
629 		break;
630 
631 	case SO_TIMESTAMP:
632 	case SO_TIMESTAMPNS:
633 		if (valbool)  {
634 			if (optname == SO_TIMESTAMP)
635 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
636 			else
637 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
638 			sock_set_flag(sk, SOCK_RCVTSTAMP);
639 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
640 		} else {
641 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
642 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
643 		}
644 		break;
645 
646 	case SO_TIMESTAMPING:
647 		if (val & ~SOF_TIMESTAMPING_MASK) {
648 			ret = -EINVAL;
649 			break;
650 		}
651 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
652 				  val & SOF_TIMESTAMPING_TX_HARDWARE);
653 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
654 				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
655 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
656 				  val & SOF_TIMESTAMPING_RX_HARDWARE);
657 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
658 			sock_enable_timestamp(sk,
659 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
660 		else
661 			sock_disable_timestamp(sk,
662 					       SOCK_TIMESTAMPING_RX_SOFTWARE);
663 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
664 				  val & SOF_TIMESTAMPING_SOFTWARE);
665 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
666 				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
667 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
668 				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
669 		break;
670 
671 	case SO_RCVLOWAT:
672 		if (val < 0)
673 			val = INT_MAX;
674 		sk->sk_rcvlowat = val ? : 1;
675 		break;
676 
677 	case SO_RCVTIMEO:
678 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
679 		break;
680 
681 	case SO_SNDTIMEO:
682 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
683 		break;
684 
685 	case SO_ATTACH_FILTER:
686 		ret = -EINVAL;
687 		if (optlen == sizeof(struct sock_fprog)) {
688 			struct sock_fprog fprog;
689 
690 			ret = -EFAULT;
691 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
692 				break;
693 
694 			ret = sk_attach_filter(&fprog, sk);
695 		}
696 		break;
697 
698 	case SO_DETACH_FILTER:
699 		ret = sk_detach_filter(sk);
700 		break;
701 
702 	case SO_PASSSEC:
703 		if (valbool)
704 			set_bit(SOCK_PASSSEC, &sock->flags);
705 		else
706 			clear_bit(SOCK_PASSSEC, &sock->flags);
707 		break;
708 	case SO_MARK:
709 		if (!capable(CAP_NET_ADMIN))
710 			ret = -EPERM;
711 		else
712 			sk->sk_mark = val;
713 		break;
714 
715 		/* We implement the SO_SNDLOWAT etc to
716 		   not be settable (1003.1g 5.3) */
717 	case SO_RXQ_OVFL:
718 		if (valbool)
719 			sock_set_flag(sk, SOCK_RXQ_OVFL);
720 		else
721 			sock_reset_flag(sk, SOCK_RXQ_OVFL);
722 		break;
723 	default:
724 		ret = -ENOPROTOOPT;
725 		break;
726 	}
727 	release_sock(sk);
728 	return ret;
729 }
730 EXPORT_SYMBOL(sock_setsockopt);
731 
732 
733 int sock_getsockopt(struct socket *sock, int level, int optname,
734 		    char __user *optval, int __user *optlen)
735 {
736 	struct sock *sk = sock->sk;
737 
738 	union {
739 		int val;
740 		struct linger ling;
741 		struct timeval tm;
742 	} v;
743 
744 	unsigned int lv = sizeof(int);
745 	int len;
746 
747 	if (get_user(len, optlen))
748 		return -EFAULT;
749 	if (len < 0)
750 		return -EINVAL;
751 
752 	memset(&v, 0, sizeof(v));
753 
754 	switch (optname) {
755 	case SO_DEBUG:
756 		v.val = sock_flag(sk, SOCK_DBG);
757 		break;
758 
759 	case SO_DONTROUTE:
760 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
761 		break;
762 
763 	case SO_BROADCAST:
764 		v.val = !!sock_flag(sk, SOCK_BROADCAST);
765 		break;
766 
767 	case SO_SNDBUF:
768 		v.val = sk->sk_sndbuf;
769 		break;
770 
771 	case SO_RCVBUF:
772 		v.val = sk->sk_rcvbuf;
773 		break;
774 
775 	case SO_REUSEADDR:
776 		v.val = sk->sk_reuse;
777 		break;
778 
779 	case SO_KEEPALIVE:
780 		v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
781 		break;
782 
783 	case SO_TYPE:
784 		v.val = sk->sk_type;
785 		break;
786 
787 	case SO_PROTOCOL:
788 		v.val = sk->sk_protocol;
789 		break;
790 
791 	case SO_DOMAIN:
792 		v.val = sk->sk_family;
793 		break;
794 
795 	case SO_ERROR:
796 		v.val = -sock_error(sk);
797 		if (v.val == 0)
798 			v.val = xchg(&sk->sk_err_soft, 0);
799 		break;
800 
801 	case SO_OOBINLINE:
802 		v.val = !!sock_flag(sk, SOCK_URGINLINE);
803 		break;
804 
805 	case SO_NO_CHECK:
806 		v.val = sk->sk_no_check;
807 		break;
808 
809 	case SO_PRIORITY:
810 		v.val = sk->sk_priority;
811 		break;
812 
813 	case SO_LINGER:
814 		lv		= sizeof(v.ling);
815 		v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
816 		v.ling.l_linger	= sk->sk_lingertime / HZ;
817 		break;
818 
819 	case SO_BSDCOMPAT:
820 		sock_warn_obsolete_bsdism("getsockopt");
821 		break;
822 
823 	case SO_TIMESTAMP:
824 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
825 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
826 		break;
827 
828 	case SO_TIMESTAMPNS:
829 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
830 		break;
831 
832 	case SO_TIMESTAMPING:
833 		v.val = 0;
834 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
835 			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
836 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
837 			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
838 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
839 			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
840 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
841 			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
842 		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
843 			v.val |= SOF_TIMESTAMPING_SOFTWARE;
844 		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
845 			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
846 		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
847 			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
848 		break;
849 
850 	case SO_RCVTIMEO:
851 		lv = sizeof(struct timeval);
852 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
853 			v.tm.tv_sec = 0;
854 			v.tm.tv_usec = 0;
855 		} else {
856 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
857 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
858 		}
859 		break;
860 
861 	case SO_SNDTIMEO:
862 		lv = sizeof(struct timeval);
863 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
864 			v.tm.tv_sec = 0;
865 			v.tm.tv_usec = 0;
866 		} else {
867 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
868 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
869 		}
870 		break;
871 
872 	case SO_RCVLOWAT:
873 		v.val = sk->sk_rcvlowat;
874 		break;
875 
876 	case SO_SNDLOWAT:
877 		v.val = 1;
878 		break;
879 
880 	case SO_PASSCRED:
881 		v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
882 		break;
883 
884 	case SO_PEERCRED:
885 		if (len > sizeof(sk->sk_peercred))
886 			len = sizeof(sk->sk_peercred);
887 		if (copy_to_user(optval, &sk->sk_peercred, len))
888 			return -EFAULT;
889 		goto lenout;
890 
891 	case SO_PEERNAME:
892 	{
893 		char address[128];
894 
895 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
896 			return -ENOTCONN;
897 		if (lv < len)
898 			return -EINVAL;
899 		if (copy_to_user(optval, address, len))
900 			return -EFAULT;
901 		goto lenout;
902 	}
903 
904 	/* Dubious BSD thing... Probably nobody even uses it, but
905 	 * the UNIX standard wants it for whatever reason... -DaveM
906 	 */
907 	case SO_ACCEPTCONN:
908 		v.val = sk->sk_state == TCP_LISTEN;
909 		break;
910 
911 	case SO_PASSSEC:
912 		v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
913 		break;
914 
915 	case SO_PEERSEC:
916 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
917 
918 	case SO_MARK:
919 		v.val = sk->sk_mark;
920 		break;
921 
922 	case SO_RXQ_OVFL:
923 		v.val = !!sock_flag(sk, SOCK_RXQ_OVFL);
924 		break;
925 
926 	default:
927 		return -ENOPROTOOPT;
928 	}
929 
930 	if (len > lv)
931 		len = lv;
932 	if (copy_to_user(optval, &v, len))
933 		return -EFAULT;
934 lenout:
935 	if (put_user(len, optlen))
936 		return -EFAULT;
937 	return 0;
938 }
939 
940 /*
941  * Initialize an sk_lock.
942  *
943  * (We also register the sk_lock with the lock validator.)
944  */
945 static inline void sock_lock_init(struct sock *sk)
946 {
947 	sock_lock_init_class_and_name(sk,
948 			af_family_slock_key_strings[sk->sk_family],
949 			af_family_slock_keys + sk->sk_family,
950 			af_family_key_strings[sk->sk_family],
951 			af_family_keys + sk->sk_family);
952 }
953 
954 /*
955  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
956  * even temporarly, because of RCU lookups. sk_node should also be left as is.
957  */
958 static void sock_copy(struct sock *nsk, const struct sock *osk)
959 {
960 #ifdef CONFIG_SECURITY_NETWORK
961 	void *sptr = nsk->sk_security;
962 #endif
963 	BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) !=
964 		     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt) +
965 		     sizeof(osk->sk_tx_queue_mapping));
966 	memcpy(&nsk->sk_copy_start, &osk->sk_copy_start,
967 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start));
968 #ifdef CONFIG_SECURITY_NETWORK
969 	nsk->sk_security = sptr;
970 	security_sk_clone(osk, nsk);
971 #endif
972 }
973 
974 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
975 		int family)
976 {
977 	struct sock *sk;
978 	struct kmem_cache *slab;
979 
980 	slab = prot->slab;
981 	if (slab != NULL) {
982 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
983 		if (!sk)
984 			return sk;
985 		if (priority & __GFP_ZERO) {
986 			/*
987 			 * caches using SLAB_DESTROY_BY_RCU should let
988 			 * sk_node.next un-modified. Special care is taken
989 			 * when initializing object to zero.
990 			 */
991 			if (offsetof(struct sock, sk_node.next) != 0)
992 				memset(sk, 0, offsetof(struct sock, sk_node.next));
993 			memset(&sk->sk_node.pprev, 0,
994 			       prot->obj_size - offsetof(struct sock,
995 							 sk_node.pprev));
996 		}
997 	}
998 	else
999 		sk = kmalloc(prot->obj_size, priority);
1000 
1001 	if (sk != NULL) {
1002 		kmemcheck_annotate_bitfield(sk, flags);
1003 
1004 		if (security_sk_alloc(sk, family, priority))
1005 			goto out_free;
1006 
1007 		if (!try_module_get(prot->owner))
1008 			goto out_free_sec;
1009 		sk_tx_queue_clear(sk);
1010 	}
1011 
1012 	return sk;
1013 
1014 out_free_sec:
1015 	security_sk_free(sk);
1016 out_free:
1017 	if (slab != NULL)
1018 		kmem_cache_free(slab, sk);
1019 	else
1020 		kfree(sk);
1021 	return NULL;
1022 }
1023 
1024 static void sk_prot_free(struct proto *prot, struct sock *sk)
1025 {
1026 	struct kmem_cache *slab;
1027 	struct module *owner;
1028 
1029 	owner = prot->owner;
1030 	slab = prot->slab;
1031 
1032 	security_sk_free(sk);
1033 	if (slab != NULL)
1034 		kmem_cache_free(slab, sk);
1035 	else
1036 		kfree(sk);
1037 	module_put(owner);
1038 }
1039 
1040 /**
1041  *	sk_alloc - All socket objects are allocated here
1042  *	@net: the applicable net namespace
1043  *	@family: protocol family
1044  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1045  *	@prot: struct proto associated with this new sock instance
1046  */
1047 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1048 		      struct proto *prot)
1049 {
1050 	struct sock *sk;
1051 
1052 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1053 	if (sk) {
1054 		sk->sk_family = family;
1055 		/*
1056 		 * See comment in struct sock definition to understand
1057 		 * why we need sk_prot_creator -acme
1058 		 */
1059 		sk->sk_prot = sk->sk_prot_creator = prot;
1060 		sock_lock_init(sk);
1061 		sock_net_set(sk, get_net(net));
1062 		atomic_set(&sk->sk_wmem_alloc, 1);
1063 	}
1064 
1065 	return sk;
1066 }
1067 EXPORT_SYMBOL(sk_alloc);
1068 
1069 static void __sk_free(struct sock *sk)
1070 {
1071 	struct sk_filter *filter;
1072 
1073 	if (sk->sk_destruct)
1074 		sk->sk_destruct(sk);
1075 
1076 	filter = rcu_dereference(sk->sk_filter);
1077 	if (filter) {
1078 		sk_filter_uncharge(sk, filter);
1079 		rcu_assign_pointer(sk->sk_filter, NULL);
1080 	}
1081 
1082 	sock_disable_timestamp(sk, SOCK_TIMESTAMP);
1083 	sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
1084 
1085 	if (atomic_read(&sk->sk_omem_alloc))
1086 		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
1087 		       __func__, atomic_read(&sk->sk_omem_alloc));
1088 
1089 	put_net(sock_net(sk));
1090 	sk_prot_free(sk->sk_prot_creator, sk);
1091 }
1092 
1093 void sk_free(struct sock *sk)
1094 {
1095 	/*
1096 	 * We substract one from sk_wmem_alloc and can know if
1097 	 * some packets are still in some tx queue.
1098 	 * If not null, sock_wfree() will call __sk_free(sk) later
1099 	 */
1100 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1101 		__sk_free(sk);
1102 }
1103 EXPORT_SYMBOL(sk_free);
1104 
1105 /*
1106  * Last sock_put should drop referrence to sk->sk_net. It has already
1107  * been dropped in sk_change_net. Taking referrence to stopping namespace
1108  * is not an option.
1109  * Take referrence to a socket to remove it from hash _alive_ and after that
1110  * destroy it in the context of init_net.
1111  */
1112 void sk_release_kernel(struct sock *sk)
1113 {
1114 	if (sk == NULL || sk->sk_socket == NULL)
1115 		return;
1116 
1117 	sock_hold(sk);
1118 	sock_release(sk->sk_socket);
1119 	release_net(sock_net(sk));
1120 	sock_net_set(sk, get_net(&init_net));
1121 	sock_put(sk);
1122 }
1123 EXPORT_SYMBOL(sk_release_kernel);
1124 
1125 struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1126 {
1127 	struct sock *newsk;
1128 
1129 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1130 	if (newsk != NULL) {
1131 		struct sk_filter *filter;
1132 
1133 		sock_copy(newsk, sk);
1134 
1135 		/* SANITY */
1136 		get_net(sock_net(newsk));
1137 		sk_node_init(&newsk->sk_node);
1138 		sock_lock_init(newsk);
1139 		bh_lock_sock(newsk);
1140 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1141 
1142 		atomic_set(&newsk->sk_rmem_alloc, 0);
1143 		/*
1144 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1145 		 */
1146 		atomic_set(&newsk->sk_wmem_alloc, 1);
1147 		atomic_set(&newsk->sk_omem_alloc, 0);
1148 		skb_queue_head_init(&newsk->sk_receive_queue);
1149 		skb_queue_head_init(&newsk->sk_write_queue);
1150 #ifdef CONFIG_NET_DMA
1151 		skb_queue_head_init(&newsk->sk_async_wait_queue);
1152 #endif
1153 
1154 		rwlock_init(&newsk->sk_dst_lock);
1155 		rwlock_init(&newsk->sk_callback_lock);
1156 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1157 				af_callback_keys + newsk->sk_family,
1158 				af_family_clock_key_strings[newsk->sk_family]);
1159 
1160 		newsk->sk_dst_cache	= NULL;
1161 		newsk->sk_wmem_queued	= 0;
1162 		newsk->sk_forward_alloc = 0;
1163 		newsk->sk_send_head	= NULL;
1164 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1165 
1166 		sock_reset_flag(newsk, SOCK_DONE);
1167 		skb_queue_head_init(&newsk->sk_error_queue);
1168 
1169 		filter = newsk->sk_filter;
1170 		if (filter != NULL)
1171 			sk_filter_charge(newsk, filter);
1172 
1173 		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1174 			/* It is still raw copy of parent, so invalidate
1175 			 * destructor and make plain sk_free() */
1176 			newsk->sk_destruct = NULL;
1177 			sk_free(newsk);
1178 			newsk = NULL;
1179 			goto out;
1180 		}
1181 
1182 		newsk->sk_err	   = 0;
1183 		newsk->sk_priority = 0;
1184 		/*
1185 		 * Before updating sk_refcnt, we must commit prior changes to memory
1186 		 * (Documentation/RCU/rculist_nulls.txt for details)
1187 		 */
1188 		smp_wmb();
1189 		atomic_set(&newsk->sk_refcnt, 2);
1190 
1191 		/*
1192 		 * Increment the counter in the same struct proto as the master
1193 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1194 		 * is the same as sk->sk_prot->socks, as this field was copied
1195 		 * with memcpy).
1196 		 *
1197 		 * This _changes_ the previous behaviour, where
1198 		 * tcp_create_openreq_child always was incrementing the
1199 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1200 		 * to be taken into account in all callers. -acme
1201 		 */
1202 		sk_refcnt_debug_inc(newsk);
1203 		sk_set_socket(newsk, NULL);
1204 		newsk->sk_sleep	 = NULL;
1205 
1206 		if (newsk->sk_prot->sockets_allocated)
1207 			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1208 	}
1209 out:
1210 	return newsk;
1211 }
1212 EXPORT_SYMBOL_GPL(sk_clone);
1213 
1214 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1215 {
1216 	__sk_dst_set(sk, dst);
1217 	sk->sk_route_caps = dst->dev->features;
1218 	if (sk->sk_route_caps & NETIF_F_GSO)
1219 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1220 	if (sk_can_gso(sk)) {
1221 		if (dst->header_len) {
1222 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1223 		} else {
1224 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1225 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1226 		}
1227 	}
1228 }
1229 EXPORT_SYMBOL_GPL(sk_setup_caps);
1230 
1231 void __init sk_init(void)
1232 {
1233 	if (totalram_pages <= 4096) {
1234 		sysctl_wmem_max = 32767;
1235 		sysctl_rmem_max = 32767;
1236 		sysctl_wmem_default = 32767;
1237 		sysctl_rmem_default = 32767;
1238 	} else if (totalram_pages >= 131072) {
1239 		sysctl_wmem_max = 131071;
1240 		sysctl_rmem_max = 131071;
1241 	}
1242 }
1243 
1244 /*
1245  *	Simple resource managers for sockets.
1246  */
1247 
1248 
1249 /*
1250  * Write buffer destructor automatically called from kfree_skb.
1251  */
1252 void sock_wfree(struct sk_buff *skb)
1253 {
1254 	struct sock *sk = skb->sk;
1255 	unsigned int len = skb->truesize;
1256 
1257 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1258 		/*
1259 		 * Keep a reference on sk_wmem_alloc, this will be released
1260 		 * after sk_write_space() call
1261 		 */
1262 		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1263 		sk->sk_write_space(sk);
1264 		len = 1;
1265 	}
1266 	/*
1267 	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1268 	 * could not do because of in-flight packets
1269 	 */
1270 	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1271 		__sk_free(sk);
1272 }
1273 EXPORT_SYMBOL(sock_wfree);
1274 
1275 /*
1276  * Read buffer destructor automatically called from kfree_skb.
1277  */
1278 void sock_rfree(struct sk_buff *skb)
1279 {
1280 	struct sock *sk = skb->sk;
1281 
1282 	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1283 	sk_mem_uncharge(skb->sk, skb->truesize);
1284 }
1285 EXPORT_SYMBOL(sock_rfree);
1286 
1287 
1288 int sock_i_uid(struct sock *sk)
1289 {
1290 	int uid;
1291 
1292 	read_lock(&sk->sk_callback_lock);
1293 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1294 	read_unlock(&sk->sk_callback_lock);
1295 	return uid;
1296 }
1297 EXPORT_SYMBOL(sock_i_uid);
1298 
1299 unsigned long sock_i_ino(struct sock *sk)
1300 {
1301 	unsigned long ino;
1302 
1303 	read_lock(&sk->sk_callback_lock);
1304 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1305 	read_unlock(&sk->sk_callback_lock);
1306 	return ino;
1307 }
1308 EXPORT_SYMBOL(sock_i_ino);
1309 
1310 /*
1311  * Allocate a skb from the socket's send buffer.
1312  */
1313 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1314 			     gfp_t priority)
1315 {
1316 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1317 		struct sk_buff *skb = alloc_skb(size, priority);
1318 		if (skb) {
1319 			skb_set_owner_w(skb, sk);
1320 			return skb;
1321 		}
1322 	}
1323 	return NULL;
1324 }
1325 EXPORT_SYMBOL(sock_wmalloc);
1326 
1327 /*
1328  * Allocate a skb from the socket's receive buffer.
1329  */
1330 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1331 			     gfp_t priority)
1332 {
1333 	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1334 		struct sk_buff *skb = alloc_skb(size, priority);
1335 		if (skb) {
1336 			skb_set_owner_r(skb, sk);
1337 			return skb;
1338 		}
1339 	}
1340 	return NULL;
1341 }
1342 
1343 /*
1344  * Allocate a memory block from the socket's option memory buffer.
1345  */
1346 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1347 {
1348 	if ((unsigned)size <= sysctl_optmem_max &&
1349 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1350 		void *mem;
1351 		/* First do the add, to avoid the race if kmalloc
1352 		 * might sleep.
1353 		 */
1354 		atomic_add(size, &sk->sk_omem_alloc);
1355 		mem = kmalloc(size, priority);
1356 		if (mem)
1357 			return mem;
1358 		atomic_sub(size, &sk->sk_omem_alloc);
1359 	}
1360 	return NULL;
1361 }
1362 EXPORT_SYMBOL(sock_kmalloc);
1363 
1364 /*
1365  * Free an option memory block.
1366  */
1367 void sock_kfree_s(struct sock *sk, void *mem, int size)
1368 {
1369 	kfree(mem);
1370 	atomic_sub(size, &sk->sk_omem_alloc);
1371 }
1372 EXPORT_SYMBOL(sock_kfree_s);
1373 
1374 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1375    I think, these locks should be removed for datagram sockets.
1376  */
1377 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1378 {
1379 	DEFINE_WAIT(wait);
1380 
1381 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1382 	for (;;) {
1383 		if (!timeo)
1384 			break;
1385 		if (signal_pending(current))
1386 			break;
1387 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1388 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1389 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1390 			break;
1391 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1392 			break;
1393 		if (sk->sk_err)
1394 			break;
1395 		timeo = schedule_timeout(timeo);
1396 	}
1397 	finish_wait(sk->sk_sleep, &wait);
1398 	return timeo;
1399 }
1400 
1401 
1402 /*
1403  *	Generic send/receive buffer handlers
1404  */
1405 
1406 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1407 				     unsigned long data_len, int noblock,
1408 				     int *errcode)
1409 {
1410 	struct sk_buff *skb;
1411 	gfp_t gfp_mask;
1412 	long timeo;
1413 	int err;
1414 
1415 	gfp_mask = sk->sk_allocation;
1416 	if (gfp_mask & __GFP_WAIT)
1417 		gfp_mask |= __GFP_REPEAT;
1418 
1419 	timeo = sock_sndtimeo(sk, noblock);
1420 	while (1) {
1421 		err = sock_error(sk);
1422 		if (err != 0)
1423 			goto failure;
1424 
1425 		err = -EPIPE;
1426 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1427 			goto failure;
1428 
1429 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1430 			skb = alloc_skb(header_len, gfp_mask);
1431 			if (skb) {
1432 				int npages;
1433 				int i;
1434 
1435 				/* No pages, we're done... */
1436 				if (!data_len)
1437 					break;
1438 
1439 				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1440 				skb->truesize += data_len;
1441 				skb_shinfo(skb)->nr_frags = npages;
1442 				for (i = 0; i < npages; i++) {
1443 					struct page *page;
1444 					skb_frag_t *frag;
1445 
1446 					page = alloc_pages(sk->sk_allocation, 0);
1447 					if (!page) {
1448 						err = -ENOBUFS;
1449 						skb_shinfo(skb)->nr_frags = i;
1450 						kfree_skb(skb);
1451 						goto failure;
1452 					}
1453 
1454 					frag = &skb_shinfo(skb)->frags[i];
1455 					frag->page = page;
1456 					frag->page_offset = 0;
1457 					frag->size = (data_len >= PAGE_SIZE ?
1458 						      PAGE_SIZE :
1459 						      data_len);
1460 					data_len -= PAGE_SIZE;
1461 				}
1462 
1463 				/* Full success... */
1464 				break;
1465 			}
1466 			err = -ENOBUFS;
1467 			goto failure;
1468 		}
1469 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1470 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1471 		err = -EAGAIN;
1472 		if (!timeo)
1473 			goto failure;
1474 		if (signal_pending(current))
1475 			goto interrupted;
1476 		timeo = sock_wait_for_wmem(sk, timeo);
1477 	}
1478 
1479 	skb_set_owner_w(skb, sk);
1480 	return skb;
1481 
1482 interrupted:
1483 	err = sock_intr_errno(timeo);
1484 failure:
1485 	*errcode = err;
1486 	return NULL;
1487 }
1488 EXPORT_SYMBOL(sock_alloc_send_pskb);
1489 
1490 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1491 				    int noblock, int *errcode)
1492 {
1493 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1494 }
1495 EXPORT_SYMBOL(sock_alloc_send_skb);
1496 
1497 static void __lock_sock(struct sock *sk)
1498 {
1499 	DEFINE_WAIT(wait);
1500 
1501 	for (;;) {
1502 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1503 					TASK_UNINTERRUPTIBLE);
1504 		spin_unlock_bh(&sk->sk_lock.slock);
1505 		schedule();
1506 		spin_lock_bh(&sk->sk_lock.slock);
1507 		if (!sock_owned_by_user(sk))
1508 			break;
1509 	}
1510 	finish_wait(&sk->sk_lock.wq, &wait);
1511 }
1512 
1513 static void __release_sock(struct sock *sk)
1514 {
1515 	struct sk_buff *skb = sk->sk_backlog.head;
1516 
1517 	do {
1518 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1519 		bh_unlock_sock(sk);
1520 
1521 		do {
1522 			struct sk_buff *next = skb->next;
1523 
1524 			skb->next = NULL;
1525 			sk_backlog_rcv(sk, skb);
1526 
1527 			/*
1528 			 * We are in process context here with softirqs
1529 			 * disabled, use cond_resched_softirq() to preempt.
1530 			 * This is safe to do because we've taken the backlog
1531 			 * queue private:
1532 			 */
1533 			cond_resched_softirq();
1534 
1535 			skb = next;
1536 		} while (skb != NULL);
1537 
1538 		bh_lock_sock(sk);
1539 	} while ((skb = sk->sk_backlog.head) != NULL);
1540 }
1541 
1542 /**
1543  * sk_wait_data - wait for data to arrive at sk_receive_queue
1544  * @sk:    sock to wait on
1545  * @timeo: for how long
1546  *
1547  * Now socket state including sk->sk_err is changed only under lock,
1548  * hence we may omit checks after joining wait queue.
1549  * We check receive queue before schedule() only as optimization;
1550  * it is very likely that release_sock() added new data.
1551  */
1552 int sk_wait_data(struct sock *sk, long *timeo)
1553 {
1554 	int rc;
1555 	DEFINE_WAIT(wait);
1556 
1557 	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1558 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1559 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1560 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1561 	finish_wait(sk->sk_sleep, &wait);
1562 	return rc;
1563 }
1564 EXPORT_SYMBOL(sk_wait_data);
1565 
1566 /**
1567  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1568  *	@sk: socket
1569  *	@size: memory size to allocate
1570  *	@kind: allocation type
1571  *
1572  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1573  *	rmem allocation. This function assumes that protocols which have
1574  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1575  */
1576 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1577 {
1578 	struct proto *prot = sk->sk_prot;
1579 	int amt = sk_mem_pages(size);
1580 	int allocated;
1581 
1582 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1583 	allocated = atomic_add_return(amt, prot->memory_allocated);
1584 
1585 	/* Under limit. */
1586 	if (allocated <= prot->sysctl_mem[0]) {
1587 		if (prot->memory_pressure && *prot->memory_pressure)
1588 			*prot->memory_pressure = 0;
1589 		return 1;
1590 	}
1591 
1592 	/* Under pressure. */
1593 	if (allocated > prot->sysctl_mem[1])
1594 		if (prot->enter_memory_pressure)
1595 			prot->enter_memory_pressure(sk);
1596 
1597 	/* Over hard limit. */
1598 	if (allocated > prot->sysctl_mem[2])
1599 		goto suppress_allocation;
1600 
1601 	/* guarantee minimum buffer size under pressure */
1602 	if (kind == SK_MEM_RECV) {
1603 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1604 			return 1;
1605 	} else { /* SK_MEM_SEND */
1606 		if (sk->sk_type == SOCK_STREAM) {
1607 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1608 				return 1;
1609 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1610 			   prot->sysctl_wmem[0])
1611 				return 1;
1612 	}
1613 
1614 	if (prot->memory_pressure) {
1615 		int alloc;
1616 
1617 		if (!*prot->memory_pressure)
1618 			return 1;
1619 		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1620 		if (prot->sysctl_mem[2] > alloc *
1621 		    sk_mem_pages(sk->sk_wmem_queued +
1622 				 atomic_read(&sk->sk_rmem_alloc) +
1623 				 sk->sk_forward_alloc))
1624 			return 1;
1625 	}
1626 
1627 suppress_allocation:
1628 
1629 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1630 		sk_stream_moderate_sndbuf(sk);
1631 
1632 		/* Fail only if socket is _under_ its sndbuf.
1633 		 * In this case we cannot block, so that we have to fail.
1634 		 */
1635 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1636 			return 1;
1637 	}
1638 
1639 	/* Alas. Undo changes. */
1640 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1641 	atomic_sub(amt, prot->memory_allocated);
1642 	return 0;
1643 }
1644 EXPORT_SYMBOL(__sk_mem_schedule);
1645 
1646 /**
1647  *	__sk_reclaim - reclaim memory_allocated
1648  *	@sk: socket
1649  */
1650 void __sk_mem_reclaim(struct sock *sk)
1651 {
1652 	struct proto *prot = sk->sk_prot;
1653 
1654 	atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1655 		   prot->memory_allocated);
1656 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1657 
1658 	if (prot->memory_pressure && *prot->memory_pressure &&
1659 	    (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1660 		*prot->memory_pressure = 0;
1661 }
1662 EXPORT_SYMBOL(__sk_mem_reclaim);
1663 
1664 
1665 /*
1666  * Set of default routines for initialising struct proto_ops when
1667  * the protocol does not support a particular function. In certain
1668  * cases where it makes no sense for a protocol to have a "do nothing"
1669  * function, some default processing is provided.
1670  */
1671 
1672 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1673 {
1674 	return -EOPNOTSUPP;
1675 }
1676 EXPORT_SYMBOL(sock_no_bind);
1677 
1678 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1679 		    int len, int flags)
1680 {
1681 	return -EOPNOTSUPP;
1682 }
1683 EXPORT_SYMBOL(sock_no_connect);
1684 
1685 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1686 {
1687 	return -EOPNOTSUPP;
1688 }
1689 EXPORT_SYMBOL(sock_no_socketpair);
1690 
1691 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1692 {
1693 	return -EOPNOTSUPP;
1694 }
1695 EXPORT_SYMBOL(sock_no_accept);
1696 
1697 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1698 		    int *len, int peer)
1699 {
1700 	return -EOPNOTSUPP;
1701 }
1702 EXPORT_SYMBOL(sock_no_getname);
1703 
1704 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1705 {
1706 	return 0;
1707 }
1708 EXPORT_SYMBOL(sock_no_poll);
1709 
1710 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1711 {
1712 	return -EOPNOTSUPP;
1713 }
1714 EXPORT_SYMBOL(sock_no_ioctl);
1715 
1716 int sock_no_listen(struct socket *sock, int backlog)
1717 {
1718 	return -EOPNOTSUPP;
1719 }
1720 EXPORT_SYMBOL(sock_no_listen);
1721 
1722 int sock_no_shutdown(struct socket *sock, int how)
1723 {
1724 	return -EOPNOTSUPP;
1725 }
1726 EXPORT_SYMBOL(sock_no_shutdown);
1727 
1728 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1729 		    char __user *optval, unsigned int optlen)
1730 {
1731 	return -EOPNOTSUPP;
1732 }
1733 EXPORT_SYMBOL(sock_no_setsockopt);
1734 
1735 int sock_no_getsockopt(struct socket *sock, int level, int optname,
1736 		    char __user *optval, int __user *optlen)
1737 {
1738 	return -EOPNOTSUPP;
1739 }
1740 EXPORT_SYMBOL(sock_no_getsockopt);
1741 
1742 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1743 		    size_t len)
1744 {
1745 	return -EOPNOTSUPP;
1746 }
1747 EXPORT_SYMBOL(sock_no_sendmsg);
1748 
1749 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1750 		    size_t len, int flags)
1751 {
1752 	return -EOPNOTSUPP;
1753 }
1754 EXPORT_SYMBOL(sock_no_recvmsg);
1755 
1756 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1757 {
1758 	/* Mirror missing mmap method error code */
1759 	return -ENODEV;
1760 }
1761 EXPORT_SYMBOL(sock_no_mmap);
1762 
1763 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1764 {
1765 	ssize_t res;
1766 	struct msghdr msg = {.msg_flags = flags};
1767 	struct kvec iov;
1768 	char *kaddr = kmap(page);
1769 	iov.iov_base = kaddr + offset;
1770 	iov.iov_len = size;
1771 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1772 	kunmap(page);
1773 	return res;
1774 }
1775 EXPORT_SYMBOL(sock_no_sendpage);
1776 
1777 /*
1778  *	Default Socket Callbacks
1779  */
1780 
1781 static void sock_def_wakeup(struct sock *sk)
1782 {
1783 	read_lock(&sk->sk_callback_lock);
1784 	if (sk_has_sleeper(sk))
1785 		wake_up_interruptible_all(sk->sk_sleep);
1786 	read_unlock(&sk->sk_callback_lock);
1787 }
1788 
1789 static void sock_def_error_report(struct sock *sk)
1790 {
1791 	read_lock(&sk->sk_callback_lock);
1792 	if (sk_has_sleeper(sk))
1793 		wake_up_interruptible_poll(sk->sk_sleep, POLLERR);
1794 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1795 	read_unlock(&sk->sk_callback_lock);
1796 }
1797 
1798 static void sock_def_readable(struct sock *sk, int len)
1799 {
1800 	read_lock(&sk->sk_callback_lock);
1801 	if (sk_has_sleeper(sk))
1802 		wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN |
1803 						POLLRDNORM | POLLRDBAND);
1804 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1805 	read_unlock(&sk->sk_callback_lock);
1806 }
1807 
1808 static void sock_def_write_space(struct sock *sk)
1809 {
1810 	read_lock(&sk->sk_callback_lock);
1811 
1812 	/* Do not wake up a writer until he can make "significant"
1813 	 * progress.  --DaveM
1814 	 */
1815 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1816 		if (sk_has_sleeper(sk))
1817 			wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
1818 						POLLWRNORM | POLLWRBAND);
1819 
1820 		/* Should agree with poll, otherwise some programs break */
1821 		if (sock_writeable(sk))
1822 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1823 	}
1824 
1825 	read_unlock(&sk->sk_callback_lock);
1826 }
1827 
1828 static void sock_def_destruct(struct sock *sk)
1829 {
1830 	kfree(sk->sk_protinfo);
1831 }
1832 
1833 void sk_send_sigurg(struct sock *sk)
1834 {
1835 	if (sk->sk_socket && sk->sk_socket->file)
1836 		if (send_sigurg(&sk->sk_socket->file->f_owner))
1837 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1838 }
1839 EXPORT_SYMBOL(sk_send_sigurg);
1840 
1841 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1842 		    unsigned long expires)
1843 {
1844 	if (!mod_timer(timer, expires))
1845 		sock_hold(sk);
1846 }
1847 EXPORT_SYMBOL(sk_reset_timer);
1848 
1849 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1850 {
1851 	if (timer_pending(timer) && del_timer(timer))
1852 		__sock_put(sk);
1853 }
1854 EXPORT_SYMBOL(sk_stop_timer);
1855 
1856 void sock_init_data(struct socket *sock, struct sock *sk)
1857 {
1858 	skb_queue_head_init(&sk->sk_receive_queue);
1859 	skb_queue_head_init(&sk->sk_write_queue);
1860 	skb_queue_head_init(&sk->sk_error_queue);
1861 #ifdef CONFIG_NET_DMA
1862 	skb_queue_head_init(&sk->sk_async_wait_queue);
1863 #endif
1864 
1865 	sk->sk_send_head	=	NULL;
1866 
1867 	init_timer(&sk->sk_timer);
1868 
1869 	sk->sk_allocation	=	GFP_KERNEL;
1870 	sk->sk_rcvbuf		=	sysctl_rmem_default;
1871 	sk->sk_sndbuf		=	sysctl_wmem_default;
1872 	sk->sk_state		=	TCP_CLOSE;
1873 	sk_set_socket(sk, sock);
1874 
1875 	sock_set_flag(sk, SOCK_ZAPPED);
1876 
1877 	if (sock) {
1878 		sk->sk_type	=	sock->type;
1879 		sk->sk_sleep	=	&sock->wait;
1880 		sock->sk	=	sk;
1881 	} else
1882 		sk->sk_sleep	=	NULL;
1883 
1884 	rwlock_init(&sk->sk_dst_lock);
1885 	rwlock_init(&sk->sk_callback_lock);
1886 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1887 			af_callback_keys + sk->sk_family,
1888 			af_family_clock_key_strings[sk->sk_family]);
1889 
1890 	sk->sk_state_change	=	sock_def_wakeup;
1891 	sk->sk_data_ready	=	sock_def_readable;
1892 	sk->sk_write_space	=	sock_def_write_space;
1893 	sk->sk_error_report	=	sock_def_error_report;
1894 	sk->sk_destruct		=	sock_def_destruct;
1895 
1896 	sk->sk_sndmsg_page	=	NULL;
1897 	sk->sk_sndmsg_off	=	0;
1898 
1899 	sk->sk_peercred.pid 	=	0;
1900 	sk->sk_peercred.uid	=	-1;
1901 	sk->sk_peercred.gid	=	-1;
1902 	sk->sk_write_pending	=	0;
1903 	sk->sk_rcvlowat		=	1;
1904 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1905 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1906 
1907 	sk->sk_stamp = ktime_set(-1L, 0);
1908 
1909 	/*
1910 	 * Before updating sk_refcnt, we must commit prior changes to memory
1911 	 * (Documentation/RCU/rculist_nulls.txt for details)
1912 	 */
1913 	smp_wmb();
1914 	atomic_set(&sk->sk_refcnt, 1);
1915 	atomic_set(&sk->sk_drops, 0);
1916 }
1917 EXPORT_SYMBOL(sock_init_data);
1918 
1919 void lock_sock_nested(struct sock *sk, int subclass)
1920 {
1921 	might_sleep();
1922 	spin_lock_bh(&sk->sk_lock.slock);
1923 	if (sk->sk_lock.owned)
1924 		__lock_sock(sk);
1925 	sk->sk_lock.owned = 1;
1926 	spin_unlock(&sk->sk_lock.slock);
1927 	/*
1928 	 * The sk_lock has mutex_lock() semantics here:
1929 	 */
1930 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
1931 	local_bh_enable();
1932 }
1933 EXPORT_SYMBOL(lock_sock_nested);
1934 
1935 void release_sock(struct sock *sk)
1936 {
1937 	/*
1938 	 * The sk_lock has mutex_unlock() semantics:
1939 	 */
1940 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1941 
1942 	spin_lock_bh(&sk->sk_lock.slock);
1943 	if (sk->sk_backlog.tail)
1944 		__release_sock(sk);
1945 	sk->sk_lock.owned = 0;
1946 	if (waitqueue_active(&sk->sk_lock.wq))
1947 		wake_up(&sk->sk_lock.wq);
1948 	spin_unlock_bh(&sk->sk_lock.slock);
1949 }
1950 EXPORT_SYMBOL(release_sock);
1951 
1952 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1953 {
1954 	struct timeval tv;
1955 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1956 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1957 	tv = ktime_to_timeval(sk->sk_stamp);
1958 	if (tv.tv_sec == -1)
1959 		return -ENOENT;
1960 	if (tv.tv_sec == 0) {
1961 		sk->sk_stamp = ktime_get_real();
1962 		tv = ktime_to_timeval(sk->sk_stamp);
1963 	}
1964 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
1965 }
1966 EXPORT_SYMBOL(sock_get_timestamp);
1967 
1968 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
1969 {
1970 	struct timespec ts;
1971 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1972 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1973 	ts = ktime_to_timespec(sk->sk_stamp);
1974 	if (ts.tv_sec == -1)
1975 		return -ENOENT;
1976 	if (ts.tv_sec == 0) {
1977 		sk->sk_stamp = ktime_get_real();
1978 		ts = ktime_to_timespec(sk->sk_stamp);
1979 	}
1980 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
1981 }
1982 EXPORT_SYMBOL(sock_get_timestampns);
1983 
1984 void sock_enable_timestamp(struct sock *sk, int flag)
1985 {
1986 	if (!sock_flag(sk, flag)) {
1987 		sock_set_flag(sk, flag);
1988 		/*
1989 		 * we just set one of the two flags which require net
1990 		 * time stamping, but time stamping might have been on
1991 		 * already because of the other one
1992 		 */
1993 		if (!sock_flag(sk,
1994 				flag == SOCK_TIMESTAMP ?
1995 				SOCK_TIMESTAMPING_RX_SOFTWARE :
1996 				SOCK_TIMESTAMP))
1997 			net_enable_timestamp();
1998 	}
1999 }
2000 
2001 /*
2002  *	Get a socket option on an socket.
2003  *
2004  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2005  *	asynchronous errors should be reported by getsockopt. We assume
2006  *	this means if you specify SO_ERROR (otherwise whats the point of it).
2007  */
2008 int sock_common_getsockopt(struct socket *sock, int level, int optname,
2009 			   char __user *optval, int __user *optlen)
2010 {
2011 	struct sock *sk = sock->sk;
2012 
2013 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2014 }
2015 EXPORT_SYMBOL(sock_common_getsockopt);
2016 
2017 #ifdef CONFIG_COMPAT
2018 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2019 				  char __user *optval, int __user *optlen)
2020 {
2021 	struct sock *sk = sock->sk;
2022 
2023 	if (sk->sk_prot->compat_getsockopt != NULL)
2024 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2025 						      optval, optlen);
2026 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2027 }
2028 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2029 #endif
2030 
2031 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2032 			struct msghdr *msg, size_t size, int flags)
2033 {
2034 	struct sock *sk = sock->sk;
2035 	int addr_len = 0;
2036 	int err;
2037 
2038 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2039 				   flags & ~MSG_DONTWAIT, &addr_len);
2040 	if (err >= 0)
2041 		msg->msg_namelen = addr_len;
2042 	return err;
2043 }
2044 EXPORT_SYMBOL(sock_common_recvmsg);
2045 
2046 /*
2047  *	Set socket options on an inet socket.
2048  */
2049 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2050 			   char __user *optval, unsigned int optlen)
2051 {
2052 	struct sock *sk = sock->sk;
2053 
2054 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2055 }
2056 EXPORT_SYMBOL(sock_common_setsockopt);
2057 
2058 #ifdef CONFIG_COMPAT
2059 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2060 				  char __user *optval, unsigned int optlen)
2061 {
2062 	struct sock *sk = sock->sk;
2063 
2064 	if (sk->sk_prot->compat_setsockopt != NULL)
2065 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2066 						      optval, optlen);
2067 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2068 }
2069 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2070 #endif
2071 
2072 void sk_common_release(struct sock *sk)
2073 {
2074 	if (sk->sk_prot->destroy)
2075 		sk->sk_prot->destroy(sk);
2076 
2077 	/*
2078 	 * Observation: when sock_common_release is called, processes have
2079 	 * no access to socket. But net still has.
2080 	 * Step one, detach it from networking:
2081 	 *
2082 	 * A. Remove from hash tables.
2083 	 */
2084 
2085 	sk->sk_prot->unhash(sk);
2086 
2087 	/*
2088 	 * In this point socket cannot receive new packets, but it is possible
2089 	 * that some packets are in flight because some CPU runs receiver and
2090 	 * did hash table lookup before we unhashed socket. They will achieve
2091 	 * receive queue and will be purged by socket destructor.
2092 	 *
2093 	 * Also we still have packets pending on receive queue and probably,
2094 	 * our own packets waiting in device queues. sock_destroy will drain
2095 	 * receive queue, but transmitted packets will delay socket destruction
2096 	 * until the last reference will be released.
2097 	 */
2098 
2099 	sock_orphan(sk);
2100 
2101 	xfrm_sk_free_policy(sk);
2102 
2103 	sk_refcnt_debug_release(sk);
2104 	sock_put(sk);
2105 }
2106 EXPORT_SYMBOL(sk_common_release);
2107 
2108 static DEFINE_RWLOCK(proto_list_lock);
2109 static LIST_HEAD(proto_list);
2110 
2111 #ifdef CONFIG_PROC_FS
2112 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2113 struct prot_inuse {
2114 	int val[PROTO_INUSE_NR];
2115 };
2116 
2117 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2118 
2119 #ifdef CONFIG_NET_NS
2120 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2121 {
2122 	int cpu = smp_processor_id();
2123 	per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
2124 }
2125 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2126 
2127 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2128 {
2129 	int cpu, idx = prot->inuse_idx;
2130 	int res = 0;
2131 
2132 	for_each_possible_cpu(cpu)
2133 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2134 
2135 	return res >= 0 ? res : 0;
2136 }
2137 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2138 
2139 static int sock_inuse_init_net(struct net *net)
2140 {
2141 	net->core.inuse = alloc_percpu(struct prot_inuse);
2142 	return net->core.inuse ? 0 : -ENOMEM;
2143 }
2144 
2145 static void sock_inuse_exit_net(struct net *net)
2146 {
2147 	free_percpu(net->core.inuse);
2148 }
2149 
2150 static struct pernet_operations net_inuse_ops = {
2151 	.init = sock_inuse_init_net,
2152 	.exit = sock_inuse_exit_net,
2153 };
2154 
2155 static __init int net_inuse_init(void)
2156 {
2157 	if (register_pernet_subsys(&net_inuse_ops))
2158 		panic("Cannot initialize net inuse counters");
2159 
2160 	return 0;
2161 }
2162 
2163 core_initcall(net_inuse_init);
2164 #else
2165 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2166 
2167 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2168 {
2169 	__get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
2170 }
2171 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2172 
2173 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2174 {
2175 	int cpu, idx = prot->inuse_idx;
2176 	int res = 0;
2177 
2178 	for_each_possible_cpu(cpu)
2179 		res += per_cpu(prot_inuse, cpu).val[idx];
2180 
2181 	return res >= 0 ? res : 0;
2182 }
2183 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2184 #endif
2185 
2186 static void assign_proto_idx(struct proto *prot)
2187 {
2188 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2189 
2190 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2191 		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2192 		return;
2193 	}
2194 
2195 	set_bit(prot->inuse_idx, proto_inuse_idx);
2196 }
2197 
2198 static void release_proto_idx(struct proto *prot)
2199 {
2200 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2201 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2202 }
2203 #else
2204 static inline void assign_proto_idx(struct proto *prot)
2205 {
2206 }
2207 
2208 static inline void release_proto_idx(struct proto *prot)
2209 {
2210 }
2211 #endif
2212 
2213 int proto_register(struct proto *prot, int alloc_slab)
2214 {
2215 	if (alloc_slab) {
2216 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2217 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2218 					NULL);
2219 
2220 		if (prot->slab == NULL) {
2221 			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2222 			       prot->name);
2223 			goto out;
2224 		}
2225 
2226 		if (prot->rsk_prot != NULL) {
2227 			static const char mask[] = "request_sock_%s";
2228 
2229 			prot->rsk_prot->slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2230 			if (prot->rsk_prot->slab_name == NULL)
2231 				goto out_free_sock_slab;
2232 
2233 			sprintf(prot->rsk_prot->slab_name, mask, prot->name);
2234 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2235 								 prot->rsk_prot->obj_size, 0,
2236 								 SLAB_HWCACHE_ALIGN, NULL);
2237 
2238 			if (prot->rsk_prot->slab == NULL) {
2239 				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2240 				       prot->name);
2241 				goto out_free_request_sock_slab_name;
2242 			}
2243 		}
2244 
2245 		if (prot->twsk_prot != NULL) {
2246 			static const char mask[] = "tw_sock_%s";
2247 
2248 			prot->twsk_prot->twsk_slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2249 
2250 			if (prot->twsk_prot->twsk_slab_name == NULL)
2251 				goto out_free_request_sock_slab;
2252 
2253 			sprintf(prot->twsk_prot->twsk_slab_name, mask, prot->name);
2254 			prot->twsk_prot->twsk_slab =
2255 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2256 						  prot->twsk_prot->twsk_obj_size,
2257 						  0,
2258 						  SLAB_HWCACHE_ALIGN |
2259 							prot->slab_flags,
2260 						  NULL);
2261 			if (prot->twsk_prot->twsk_slab == NULL)
2262 				goto out_free_timewait_sock_slab_name;
2263 		}
2264 	}
2265 
2266 	write_lock(&proto_list_lock);
2267 	list_add(&prot->node, &proto_list);
2268 	assign_proto_idx(prot);
2269 	write_unlock(&proto_list_lock);
2270 	return 0;
2271 
2272 out_free_timewait_sock_slab_name:
2273 	kfree(prot->twsk_prot->twsk_slab_name);
2274 out_free_request_sock_slab:
2275 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2276 		kmem_cache_destroy(prot->rsk_prot->slab);
2277 		prot->rsk_prot->slab = NULL;
2278 	}
2279 out_free_request_sock_slab_name:
2280 	kfree(prot->rsk_prot->slab_name);
2281 out_free_sock_slab:
2282 	kmem_cache_destroy(prot->slab);
2283 	prot->slab = NULL;
2284 out:
2285 	return -ENOBUFS;
2286 }
2287 EXPORT_SYMBOL(proto_register);
2288 
2289 void proto_unregister(struct proto *prot)
2290 {
2291 	write_lock(&proto_list_lock);
2292 	release_proto_idx(prot);
2293 	list_del(&prot->node);
2294 	write_unlock(&proto_list_lock);
2295 
2296 	if (prot->slab != NULL) {
2297 		kmem_cache_destroy(prot->slab);
2298 		prot->slab = NULL;
2299 	}
2300 
2301 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2302 		kmem_cache_destroy(prot->rsk_prot->slab);
2303 		kfree(prot->rsk_prot->slab_name);
2304 		prot->rsk_prot->slab = NULL;
2305 	}
2306 
2307 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2308 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2309 		kfree(prot->twsk_prot->twsk_slab_name);
2310 		prot->twsk_prot->twsk_slab = NULL;
2311 	}
2312 }
2313 EXPORT_SYMBOL(proto_unregister);
2314 
2315 #ifdef CONFIG_PROC_FS
2316 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2317 	__acquires(proto_list_lock)
2318 {
2319 	read_lock(&proto_list_lock);
2320 	return seq_list_start_head(&proto_list, *pos);
2321 }
2322 
2323 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2324 {
2325 	return seq_list_next(v, &proto_list, pos);
2326 }
2327 
2328 static void proto_seq_stop(struct seq_file *seq, void *v)
2329 	__releases(proto_list_lock)
2330 {
2331 	read_unlock(&proto_list_lock);
2332 }
2333 
2334 static char proto_method_implemented(const void *method)
2335 {
2336 	return method == NULL ? 'n' : 'y';
2337 }
2338 
2339 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2340 {
2341 	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
2342 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2343 		   proto->name,
2344 		   proto->obj_size,
2345 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2346 		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
2347 		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2348 		   proto->max_header,
2349 		   proto->slab == NULL ? "no" : "yes",
2350 		   module_name(proto->owner),
2351 		   proto_method_implemented(proto->close),
2352 		   proto_method_implemented(proto->connect),
2353 		   proto_method_implemented(proto->disconnect),
2354 		   proto_method_implemented(proto->accept),
2355 		   proto_method_implemented(proto->ioctl),
2356 		   proto_method_implemented(proto->init),
2357 		   proto_method_implemented(proto->destroy),
2358 		   proto_method_implemented(proto->shutdown),
2359 		   proto_method_implemented(proto->setsockopt),
2360 		   proto_method_implemented(proto->getsockopt),
2361 		   proto_method_implemented(proto->sendmsg),
2362 		   proto_method_implemented(proto->recvmsg),
2363 		   proto_method_implemented(proto->sendpage),
2364 		   proto_method_implemented(proto->bind),
2365 		   proto_method_implemented(proto->backlog_rcv),
2366 		   proto_method_implemented(proto->hash),
2367 		   proto_method_implemented(proto->unhash),
2368 		   proto_method_implemented(proto->get_port),
2369 		   proto_method_implemented(proto->enter_memory_pressure));
2370 }
2371 
2372 static int proto_seq_show(struct seq_file *seq, void *v)
2373 {
2374 	if (v == &proto_list)
2375 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2376 			   "protocol",
2377 			   "size",
2378 			   "sockets",
2379 			   "memory",
2380 			   "press",
2381 			   "maxhdr",
2382 			   "slab",
2383 			   "module",
2384 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2385 	else
2386 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2387 	return 0;
2388 }
2389 
2390 static const struct seq_operations proto_seq_ops = {
2391 	.start  = proto_seq_start,
2392 	.next   = proto_seq_next,
2393 	.stop   = proto_seq_stop,
2394 	.show   = proto_seq_show,
2395 };
2396 
2397 static int proto_seq_open(struct inode *inode, struct file *file)
2398 {
2399 	return seq_open_net(inode, file, &proto_seq_ops,
2400 			    sizeof(struct seq_net_private));
2401 }
2402 
2403 static const struct file_operations proto_seq_fops = {
2404 	.owner		= THIS_MODULE,
2405 	.open		= proto_seq_open,
2406 	.read		= seq_read,
2407 	.llseek		= seq_lseek,
2408 	.release	= seq_release_net,
2409 };
2410 
2411 static __net_init int proto_init_net(struct net *net)
2412 {
2413 	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2414 		return -ENOMEM;
2415 
2416 	return 0;
2417 }
2418 
2419 static __net_exit void proto_exit_net(struct net *net)
2420 {
2421 	proc_net_remove(net, "protocols");
2422 }
2423 
2424 
2425 static __net_initdata struct pernet_operations proto_net_ops = {
2426 	.init = proto_init_net,
2427 	.exit = proto_exit_net,
2428 };
2429 
2430 static int __init proto_init(void)
2431 {
2432 	return register_pernet_subsys(&proto_net_ops);
2433 }
2434 
2435 subsys_initcall(proto_init);
2436 
2437 #endif /* PROC_FS */
2438