xref: /linux/net/core/sock.c (revision 27258e448eb301cf89e351df87aa8cb916653bf2)
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 = 0;
278 	int skb_len;
279 
280 	/* Cast sk->rcvbuf to unsigned... It's pointless, but reduces
281 	   number of warnings when compiling with -W --ANK
282 	 */
283 	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
284 	    (unsigned)sk->sk_rcvbuf) {
285 		err = -ENOMEM;
286 		goto out;
287 	}
288 
289 	err = sk_filter(sk, skb);
290 	if (err)
291 		goto out;
292 
293 	if (!sk_rmem_schedule(sk, skb->truesize)) {
294 		err = -ENOBUFS;
295 		goto out;
296 	}
297 
298 	skb->dev = NULL;
299 	skb_set_owner_r(skb, sk);
300 
301 	/* Cache the SKB length before we tack it onto the receive
302 	 * queue.  Once it is added it no longer belongs to us and
303 	 * may be freed by other threads of control pulling packets
304 	 * from the queue.
305 	 */
306 	skb_len = skb->len;
307 
308 	skb_queue_tail(&sk->sk_receive_queue, skb);
309 
310 	if (!sock_flag(sk, SOCK_DEAD))
311 		sk->sk_data_ready(sk, skb_len);
312 out:
313 	return err;
314 }
315 EXPORT_SYMBOL(sock_queue_rcv_skb);
316 
317 int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
318 {
319 	int rc = NET_RX_SUCCESS;
320 
321 	if (sk_filter(sk, skb))
322 		goto discard_and_relse;
323 
324 	skb->dev = NULL;
325 
326 	if (nested)
327 		bh_lock_sock_nested(sk);
328 	else
329 		bh_lock_sock(sk);
330 	if (!sock_owned_by_user(sk)) {
331 		/*
332 		 * trylock + unlock semantics:
333 		 */
334 		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
335 
336 		rc = sk_backlog_rcv(sk, skb);
337 
338 		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
339 	} else
340 		sk_add_backlog(sk, skb);
341 	bh_unlock_sock(sk);
342 out:
343 	sock_put(sk);
344 	return rc;
345 discard_and_relse:
346 	kfree_skb(skb);
347 	goto out;
348 }
349 EXPORT_SYMBOL(sk_receive_skb);
350 
351 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
352 {
353 	struct dst_entry *dst = sk->sk_dst_cache;
354 
355 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
356 		sk->sk_dst_cache = NULL;
357 		dst_release(dst);
358 		return NULL;
359 	}
360 
361 	return dst;
362 }
363 EXPORT_SYMBOL(__sk_dst_check);
364 
365 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
366 {
367 	struct dst_entry *dst = sk_dst_get(sk);
368 
369 	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
370 		sk_dst_reset(sk);
371 		dst_release(dst);
372 		return NULL;
373 	}
374 
375 	return dst;
376 }
377 EXPORT_SYMBOL(sk_dst_check);
378 
379 static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
380 {
381 	int ret = -ENOPROTOOPT;
382 #ifdef CONFIG_NETDEVICES
383 	struct net *net = sock_net(sk);
384 	char devname[IFNAMSIZ];
385 	int index;
386 
387 	/* Sorry... */
388 	ret = -EPERM;
389 	if (!capable(CAP_NET_RAW))
390 		goto out;
391 
392 	ret = -EINVAL;
393 	if (optlen < 0)
394 		goto out;
395 
396 	/* Bind this socket to a particular device like "eth0",
397 	 * as specified in the passed interface name. If the
398 	 * name is "" or the option length is zero the socket
399 	 * is not bound.
400 	 */
401 	if (optlen > IFNAMSIZ - 1)
402 		optlen = IFNAMSIZ - 1;
403 	memset(devname, 0, sizeof(devname));
404 
405 	ret = -EFAULT;
406 	if (copy_from_user(devname, optval, optlen))
407 		goto out;
408 
409 	if (devname[0] == '\0') {
410 		index = 0;
411 	} else {
412 		struct net_device *dev = dev_get_by_name(net, devname);
413 
414 		ret = -ENODEV;
415 		if (!dev)
416 			goto out;
417 
418 		index = dev->ifindex;
419 		dev_put(dev);
420 	}
421 
422 	lock_sock(sk);
423 	sk->sk_bound_dev_if = index;
424 	sk_dst_reset(sk);
425 	release_sock(sk);
426 
427 	ret = 0;
428 
429 out:
430 #endif
431 
432 	return ret;
433 }
434 
435 static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
436 {
437 	if (valbool)
438 		sock_set_flag(sk, bit);
439 	else
440 		sock_reset_flag(sk, bit);
441 }
442 
443 /*
444  *	This is meant for all protocols to use and covers goings on
445  *	at the socket level. Everything here is generic.
446  */
447 
448 int sock_setsockopt(struct socket *sock, int level, int optname,
449 		    char __user *optval, int optlen)
450 {
451 	struct sock *sk = sock->sk;
452 	int val;
453 	int valbool;
454 	struct linger ling;
455 	int ret = 0;
456 
457 	/*
458 	 *	Options without arguments
459 	 */
460 
461 	if (optname == SO_BINDTODEVICE)
462 		return sock_bindtodevice(sk, optval, optlen);
463 
464 	if (optlen < sizeof(int))
465 		return -EINVAL;
466 
467 	if (get_user(val, (int __user *)optval))
468 		return -EFAULT;
469 
470 	valbool = val ? 1 : 0;
471 
472 	lock_sock(sk);
473 
474 	switch (optname) {
475 	case SO_DEBUG:
476 		if (val && !capable(CAP_NET_ADMIN))
477 			ret = -EACCES;
478 		else
479 			sock_valbool_flag(sk, SOCK_DBG, valbool);
480 		break;
481 	case SO_REUSEADDR:
482 		sk->sk_reuse = valbool;
483 		break;
484 	case SO_TYPE:
485 	case SO_PROTOCOL:
486 	case SO_DOMAIN:
487 	case SO_ERROR:
488 		ret = -ENOPROTOOPT;
489 		break;
490 	case SO_DONTROUTE:
491 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
492 		break;
493 	case SO_BROADCAST:
494 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
495 		break;
496 	case SO_SNDBUF:
497 		/* Don't error on this BSD doesn't and if you think
498 		   about it this is right. Otherwise apps have to
499 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
500 		   are treated in BSD as hints */
501 
502 		if (val > sysctl_wmem_max)
503 			val = sysctl_wmem_max;
504 set_sndbuf:
505 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
506 		if ((val * 2) < SOCK_MIN_SNDBUF)
507 			sk->sk_sndbuf = SOCK_MIN_SNDBUF;
508 		else
509 			sk->sk_sndbuf = val * 2;
510 
511 		/*
512 		 *	Wake up sending tasks if we
513 		 *	upped the value.
514 		 */
515 		sk->sk_write_space(sk);
516 		break;
517 
518 	case SO_SNDBUFFORCE:
519 		if (!capable(CAP_NET_ADMIN)) {
520 			ret = -EPERM;
521 			break;
522 		}
523 		goto set_sndbuf;
524 
525 	case SO_RCVBUF:
526 		/* Don't error on this BSD doesn't and if you think
527 		   about it this is right. Otherwise apps have to
528 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
529 		   are treated in BSD as hints */
530 
531 		if (val > sysctl_rmem_max)
532 			val = sysctl_rmem_max;
533 set_rcvbuf:
534 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
535 		/*
536 		 * We double it on the way in to account for
537 		 * "struct sk_buff" etc. overhead.   Applications
538 		 * assume that the SO_RCVBUF setting they make will
539 		 * allow that much actual data to be received on that
540 		 * socket.
541 		 *
542 		 * Applications are unaware that "struct sk_buff" and
543 		 * other overheads allocate from the receive buffer
544 		 * during socket buffer allocation.
545 		 *
546 		 * And after considering the possible alternatives,
547 		 * returning the value we actually used in getsockopt
548 		 * is the most desirable behavior.
549 		 */
550 		if ((val * 2) < SOCK_MIN_RCVBUF)
551 			sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
552 		else
553 			sk->sk_rcvbuf = val * 2;
554 		break;
555 
556 	case SO_RCVBUFFORCE:
557 		if (!capable(CAP_NET_ADMIN)) {
558 			ret = -EPERM;
559 			break;
560 		}
561 		goto set_rcvbuf;
562 
563 	case SO_KEEPALIVE:
564 #ifdef CONFIG_INET
565 		if (sk->sk_protocol == IPPROTO_TCP)
566 			tcp_set_keepalive(sk, valbool);
567 #endif
568 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
569 		break;
570 
571 	case SO_OOBINLINE:
572 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
573 		break;
574 
575 	case SO_NO_CHECK:
576 		sk->sk_no_check = valbool;
577 		break;
578 
579 	case SO_PRIORITY:
580 		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
581 			sk->sk_priority = val;
582 		else
583 			ret = -EPERM;
584 		break;
585 
586 	case SO_LINGER:
587 		if (optlen < sizeof(ling)) {
588 			ret = -EINVAL;	/* 1003.1g */
589 			break;
590 		}
591 		if (copy_from_user(&ling, optval, sizeof(ling))) {
592 			ret = -EFAULT;
593 			break;
594 		}
595 		if (!ling.l_onoff)
596 			sock_reset_flag(sk, SOCK_LINGER);
597 		else {
598 #if (BITS_PER_LONG == 32)
599 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
600 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
601 			else
602 #endif
603 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
604 			sock_set_flag(sk, SOCK_LINGER);
605 		}
606 		break;
607 
608 	case SO_BSDCOMPAT:
609 		sock_warn_obsolete_bsdism("setsockopt");
610 		break;
611 
612 	case SO_PASSCRED:
613 		if (valbool)
614 			set_bit(SOCK_PASSCRED, &sock->flags);
615 		else
616 			clear_bit(SOCK_PASSCRED, &sock->flags);
617 		break;
618 
619 	case SO_TIMESTAMP:
620 	case SO_TIMESTAMPNS:
621 		if (valbool)  {
622 			if (optname == SO_TIMESTAMP)
623 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
624 			else
625 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
626 			sock_set_flag(sk, SOCK_RCVTSTAMP);
627 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
628 		} else {
629 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
630 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
631 		}
632 		break;
633 
634 	case SO_TIMESTAMPING:
635 		if (val & ~SOF_TIMESTAMPING_MASK) {
636 			ret = -EINVAL;
637 			break;
638 		}
639 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
640 				  val & SOF_TIMESTAMPING_TX_HARDWARE);
641 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
642 				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
643 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
644 				  val & SOF_TIMESTAMPING_RX_HARDWARE);
645 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
646 			sock_enable_timestamp(sk,
647 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
648 		else
649 			sock_disable_timestamp(sk,
650 					       SOCK_TIMESTAMPING_RX_SOFTWARE);
651 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
652 				  val & SOF_TIMESTAMPING_SOFTWARE);
653 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
654 				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
655 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
656 				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
657 		break;
658 
659 	case SO_RCVLOWAT:
660 		if (val < 0)
661 			val = INT_MAX;
662 		sk->sk_rcvlowat = val ? : 1;
663 		break;
664 
665 	case SO_RCVTIMEO:
666 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
667 		break;
668 
669 	case SO_SNDTIMEO:
670 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
671 		break;
672 
673 	case SO_ATTACH_FILTER:
674 		ret = -EINVAL;
675 		if (optlen == sizeof(struct sock_fprog)) {
676 			struct sock_fprog fprog;
677 
678 			ret = -EFAULT;
679 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
680 				break;
681 
682 			ret = sk_attach_filter(&fprog, sk);
683 		}
684 		break;
685 
686 	case SO_DETACH_FILTER:
687 		ret = sk_detach_filter(sk);
688 		break;
689 
690 	case SO_PASSSEC:
691 		if (valbool)
692 			set_bit(SOCK_PASSSEC, &sock->flags);
693 		else
694 			clear_bit(SOCK_PASSSEC, &sock->flags);
695 		break;
696 	case SO_MARK:
697 		if (!capable(CAP_NET_ADMIN))
698 			ret = -EPERM;
699 		else
700 			sk->sk_mark = val;
701 		break;
702 
703 		/* We implement the SO_SNDLOWAT etc to
704 		   not be settable (1003.1g 5.3) */
705 	default:
706 		ret = -ENOPROTOOPT;
707 		break;
708 	}
709 	release_sock(sk);
710 	return ret;
711 }
712 EXPORT_SYMBOL(sock_setsockopt);
713 
714 
715 int sock_getsockopt(struct socket *sock, int level, int optname,
716 		    char __user *optval, int __user *optlen)
717 {
718 	struct sock *sk = sock->sk;
719 
720 	union {
721 		int val;
722 		struct linger ling;
723 		struct timeval tm;
724 	} v;
725 
726 	unsigned int lv = sizeof(int);
727 	int len;
728 
729 	if (get_user(len, optlen))
730 		return -EFAULT;
731 	if (len < 0)
732 		return -EINVAL;
733 
734 	memset(&v, 0, sizeof(v));
735 
736 	switch (optname) {
737 	case SO_DEBUG:
738 		v.val = sock_flag(sk, SOCK_DBG);
739 		break;
740 
741 	case SO_DONTROUTE:
742 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
743 		break;
744 
745 	case SO_BROADCAST:
746 		v.val = !!sock_flag(sk, SOCK_BROADCAST);
747 		break;
748 
749 	case SO_SNDBUF:
750 		v.val = sk->sk_sndbuf;
751 		break;
752 
753 	case SO_RCVBUF:
754 		v.val = sk->sk_rcvbuf;
755 		break;
756 
757 	case SO_REUSEADDR:
758 		v.val = sk->sk_reuse;
759 		break;
760 
761 	case SO_KEEPALIVE:
762 		v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
763 		break;
764 
765 	case SO_TYPE:
766 		v.val = sk->sk_type;
767 		break;
768 
769 	case SO_PROTOCOL:
770 		v.val = sk->sk_protocol;
771 		break;
772 
773 	case SO_DOMAIN:
774 		v.val = sk->sk_family;
775 		break;
776 
777 	case SO_ERROR:
778 		v.val = -sock_error(sk);
779 		if (v.val == 0)
780 			v.val = xchg(&sk->sk_err_soft, 0);
781 		break;
782 
783 	case SO_OOBINLINE:
784 		v.val = !!sock_flag(sk, SOCK_URGINLINE);
785 		break;
786 
787 	case SO_NO_CHECK:
788 		v.val = sk->sk_no_check;
789 		break;
790 
791 	case SO_PRIORITY:
792 		v.val = sk->sk_priority;
793 		break;
794 
795 	case SO_LINGER:
796 		lv		= sizeof(v.ling);
797 		v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
798 		v.ling.l_linger	= sk->sk_lingertime / HZ;
799 		break;
800 
801 	case SO_BSDCOMPAT:
802 		sock_warn_obsolete_bsdism("getsockopt");
803 		break;
804 
805 	case SO_TIMESTAMP:
806 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
807 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
808 		break;
809 
810 	case SO_TIMESTAMPNS:
811 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
812 		break;
813 
814 	case SO_TIMESTAMPING:
815 		v.val = 0;
816 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
817 			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
818 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
819 			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
820 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
821 			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
822 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
823 			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
824 		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
825 			v.val |= SOF_TIMESTAMPING_SOFTWARE;
826 		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
827 			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
828 		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
829 			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
830 		break;
831 
832 	case SO_RCVTIMEO:
833 		lv = sizeof(struct timeval);
834 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
835 			v.tm.tv_sec = 0;
836 			v.tm.tv_usec = 0;
837 		} else {
838 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
839 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
840 		}
841 		break;
842 
843 	case SO_SNDTIMEO:
844 		lv = sizeof(struct timeval);
845 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
846 			v.tm.tv_sec = 0;
847 			v.tm.tv_usec = 0;
848 		} else {
849 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
850 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
851 		}
852 		break;
853 
854 	case SO_RCVLOWAT:
855 		v.val = sk->sk_rcvlowat;
856 		break;
857 
858 	case SO_SNDLOWAT:
859 		v.val = 1;
860 		break;
861 
862 	case SO_PASSCRED:
863 		v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
864 		break;
865 
866 	case SO_PEERCRED:
867 		if (len > sizeof(sk->sk_peercred))
868 			len = sizeof(sk->sk_peercred);
869 		if (copy_to_user(optval, &sk->sk_peercred, len))
870 			return -EFAULT;
871 		goto lenout;
872 
873 	case SO_PEERNAME:
874 	{
875 		char address[128];
876 
877 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
878 			return -ENOTCONN;
879 		if (lv < len)
880 			return -EINVAL;
881 		if (copy_to_user(optval, address, len))
882 			return -EFAULT;
883 		goto lenout;
884 	}
885 
886 	/* Dubious BSD thing... Probably nobody even uses it, but
887 	 * the UNIX standard wants it for whatever reason... -DaveM
888 	 */
889 	case SO_ACCEPTCONN:
890 		v.val = sk->sk_state == TCP_LISTEN;
891 		break;
892 
893 	case SO_PASSSEC:
894 		v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
895 		break;
896 
897 	case SO_PEERSEC:
898 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
899 
900 	case SO_MARK:
901 		v.val = sk->sk_mark;
902 		break;
903 
904 	default:
905 		return -ENOPROTOOPT;
906 	}
907 
908 	if (len > lv)
909 		len = lv;
910 	if (copy_to_user(optval, &v, len))
911 		return -EFAULT;
912 lenout:
913 	if (put_user(len, optlen))
914 		return -EFAULT;
915 	return 0;
916 }
917 
918 /*
919  * Initialize an sk_lock.
920  *
921  * (We also register the sk_lock with the lock validator.)
922  */
923 static inline void sock_lock_init(struct sock *sk)
924 {
925 	sock_lock_init_class_and_name(sk,
926 			af_family_slock_key_strings[sk->sk_family],
927 			af_family_slock_keys + sk->sk_family,
928 			af_family_key_strings[sk->sk_family],
929 			af_family_keys + sk->sk_family);
930 }
931 
932 /*
933  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
934  * even temporarly, because of RCU lookups. sk_node should also be left as is.
935  */
936 static void sock_copy(struct sock *nsk, const struct sock *osk)
937 {
938 #ifdef CONFIG_SECURITY_NETWORK
939 	void *sptr = nsk->sk_security;
940 #endif
941 	BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) !=
942 		     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt));
943 	memcpy(&nsk->sk_copy_start, &osk->sk_copy_start,
944 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start));
945 #ifdef CONFIG_SECURITY_NETWORK
946 	nsk->sk_security = sptr;
947 	security_sk_clone(osk, nsk);
948 #endif
949 }
950 
951 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
952 		int family)
953 {
954 	struct sock *sk;
955 	struct kmem_cache *slab;
956 
957 	slab = prot->slab;
958 	if (slab != NULL) {
959 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
960 		if (!sk)
961 			return sk;
962 		if (priority & __GFP_ZERO) {
963 			/*
964 			 * caches using SLAB_DESTROY_BY_RCU should let
965 			 * sk_node.next un-modified. Special care is taken
966 			 * when initializing object to zero.
967 			 */
968 			if (offsetof(struct sock, sk_node.next) != 0)
969 				memset(sk, 0, offsetof(struct sock, sk_node.next));
970 			memset(&sk->sk_node.pprev, 0,
971 			       prot->obj_size - offsetof(struct sock,
972 							 sk_node.pprev));
973 		}
974 	}
975 	else
976 		sk = kmalloc(prot->obj_size, priority);
977 
978 	if (sk != NULL) {
979 		kmemcheck_annotate_bitfield(sk, flags);
980 
981 		if (security_sk_alloc(sk, family, priority))
982 			goto out_free;
983 
984 		if (!try_module_get(prot->owner))
985 			goto out_free_sec;
986 	}
987 
988 	return sk;
989 
990 out_free_sec:
991 	security_sk_free(sk);
992 out_free:
993 	if (slab != NULL)
994 		kmem_cache_free(slab, sk);
995 	else
996 		kfree(sk);
997 	return NULL;
998 }
999 
1000 static void sk_prot_free(struct proto *prot, struct sock *sk)
1001 {
1002 	struct kmem_cache *slab;
1003 	struct module *owner;
1004 
1005 	owner = prot->owner;
1006 	slab = prot->slab;
1007 
1008 	security_sk_free(sk);
1009 	if (slab != NULL)
1010 		kmem_cache_free(slab, sk);
1011 	else
1012 		kfree(sk);
1013 	module_put(owner);
1014 }
1015 
1016 /**
1017  *	sk_alloc - All socket objects are allocated here
1018  *	@net: the applicable net namespace
1019  *	@family: protocol family
1020  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1021  *	@prot: struct proto associated with this new sock instance
1022  */
1023 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1024 		      struct proto *prot)
1025 {
1026 	struct sock *sk;
1027 
1028 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1029 	if (sk) {
1030 		sk->sk_family = family;
1031 		/*
1032 		 * See comment in struct sock definition to understand
1033 		 * why we need sk_prot_creator -acme
1034 		 */
1035 		sk->sk_prot = sk->sk_prot_creator = prot;
1036 		sock_lock_init(sk);
1037 		sock_net_set(sk, get_net(net));
1038 		atomic_set(&sk->sk_wmem_alloc, 1);
1039 	}
1040 
1041 	return sk;
1042 }
1043 EXPORT_SYMBOL(sk_alloc);
1044 
1045 static void __sk_free(struct sock *sk)
1046 {
1047 	struct sk_filter *filter;
1048 
1049 	if (sk->sk_destruct)
1050 		sk->sk_destruct(sk);
1051 
1052 	filter = rcu_dereference(sk->sk_filter);
1053 	if (filter) {
1054 		sk_filter_uncharge(sk, filter);
1055 		rcu_assign_pointer(sk->sk_filter, NULL);
1056 	}
1057 
1058 	sock_disable_timestamp(sk, SOCK_TIMESTAMP);
1059 	sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
1060 
1061 	if (atomic_read(&sk->sk_omem_alloc))
1062 		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
1063 		       __func__, atomic_read(&sk->sk_omem_alloc));
1064 
1065 	put_net(sock_net(sk));
1066 	sk_prot_free(sk->sk_prot_creator, sk);
1067 }
1068 
1069 void sk_free(struct sock *sk)
1070 {
1071 	/*
1072 	 * We substract one from sk_wmem_alloc and can know if
1073 	 * some packets are still in some tx queue.
1074 	 * If not null, sock_wfree() will call __sk_free(sk) later
1075 	 */
1076 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1077 		__sk_free(sk);
1078 }
1079 EXPORT_SYMBOL(sk_free);
1080 
1081 /*
1082  * Last sock_put should drop referrence to sk->sk_net. It has already
1083  * been dropped in sk_change_net. Taking referrence to stopping namespace
1084  * is not an option.
1085  * Take referrence to a socket to remove it from hash _alive_ and after that
1086  * destroy it in the context of init_net.
1087  */
1088 void sk_release_kernel(struct sock *sk)
1089 {
1090 	if (sk == NULL || sk->sk_socket == NULL)
1091 		return;
1092 
1093 	sock_hold(sk);
1094 	sock_release(sk->sk_socket);
1095 	release_net(sock_net(sk));
1096 	sock_net_set(sk, get_net(&init_net));
1097 	sock_put(sk);
1098 }
1099 EXPORT_SYMBOL(sk_release_kernel);
1100 
1101 struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1102 {
1103 	struct sock *newsk;
1104 
1105 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1106 	if (newsk != NULL) {
1107 		struct sk_filter *filter;
1108 
1109 		sock_copy(newsk, sk);
1110 
1111 		/* SANITY */
1112 		get_net(sock_net(newsk));
1113 		sk_node_init(&newsk->sk_node);
1114 		sock_lock_init(newsk);
1115 		bh_lock_sock(newsk);
1116 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1117 
1118 		atomic_set(&newsk->sk_rmem_alloc, 0);
1119 		/*
1120 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1121 		 */
1122 		atomic_set(&newsk->sk_wmem_alloc, 1);
1123 		atomic_set(&newsk->sk_omem_alloc, 0);
1124 		skb_queue_head_init(&newsk->sk_receive_queue);
1125 		skb_queue_head_init(&newsk->sk_write_queue);
1126 #ifdef CONFIG_NET_DMA
1127 		skb_queue_head_init(&newsk->sk_async_wait_queue);
1128 #endif
1129 
1130 		rwlock_init(&newsk->sk_dst_lock);
1131 		rwlock_init(&newsk->sk_callback_lock);
1132 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1133 				af_callback_keys + newsk->sk_family,
1134 				af_family_clock_key_strings[newsk->sk_family]);
1135 
1136 		newsk->sk_dst_cache	= NULL;
1137 		newsk->sk_wmem_queued	= 0;
1138 		newsk->sk_forward_alloc = 0;
1139 		newsk->sk_send_head	= NULL;
1140 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1141 
1142 		sock_reset_flag(newsk, SOCK_DONE);
1143 		skb_queue_head_init(&newsk->sk_error_queue);
1144 
1145 		filter = newsk->sk_filter;
1146 		if (filter != NULL)
1147 			sk_filter_charge(newsk, filter);
1148 
1149 		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1150 			/* It is still raw copy of parent, so invalidate
1151 			 * destructor and make plain sk_free() */
1152 			newsk->sk_destruct = NULL;
1153 			sk_free(newsk);
1154 			newsk = NULL;
1155 			goto out;
1156 		}
1157 
1158 		newsk->sk_err	   = 0;
1159 		newsk->sk_priority = 0;
1160 		/*
1161 		 * Before updating sk_refcnt, we must commit prior changes to memory
1162 		 * (Documentation/RCU/rculist_nulls.txt for details)
1163 		 */
1164 		smp_wmb();
1165 		atomic_set(&newsk->sk_refcnt, 2);
1166 
1167 		/*
1168 		 * Increment the counter in the same struct proto as the master
1169 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1170 		 * is the same as sk->sk_prot->socks, as this field was copied
1171 		 * with memcpy).
1172 		 *
1173 		 * This _changes_ the previous behaviour, where
1174 		 * tcp_create_openreq_child always was incrementing the
1175 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1176 		 * to be taken into account in all callers. -acme
1177 		 */
1178 		sk_refcnt_debug_inc(newsk);
1179 		sk_set_socket(newsk, NULL);
1180 		newsk->sk_sleep	 = NULL;
1181 
1182 		if (newsk->sk_prot->sockets_allocated)
1183 			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1184 	}
1185 out:
1186 	return newsk;
1187 }
1188 EXPORT_SYMBOL_GPL(sk_clone);
1189 
1190 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1191 {
1192 	__sk_dst_set(sk, dst);
1193 	sk->sk_route_caps = dst->dev->features;
1194 	if (sk->sk_route_caps & NETIF_F_GSO)
1195 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1196 	if (sk_can_gso(sk)) {
1197 		if (dst->header_len) {
1198 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1199 		} else {
1200 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1201 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1202 		}
1203 	}
1204 }
1205 EXPORT_SYMBOL_GPL(sk_setup_caps);
1206 
1207 void __init sk_init(void)
1208 {
1209 	if (totalram_pages <= 4096) {
1210 		sysctl_wmem_max = 32767;
1211 		sysctl_rmem_max = 32767;
1212 		sysctl_wmem_default = 32767;
1213 		sysctl_rmem_default = 32767;
1214 	} else if (totalram_pages >= 131072) {
1215 		sysctl_wmem_max = 131071;
1216 		sysctl_rmem_max = 131071;
1217 	}
1218 }
1219 
1220 /*
1221  *	Simple resource managers for sockets.
1222  */
1223 
1224 
1225 /*
1226  * Write buffer destructor automatically called from kfree_skb.
1227  */
1228 void sock_wfree(struct sk_buff *skb)
1229 {
1230 	struct sock *sk = skb->sk;
1231 	int res;
1232 
1233 	/* In case it might be waiting for more memory. */
1234 	res = atomic_sub_return(skb->truesize, &sk->sk_wmem_alloc);
1235 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE))
1236 		sk->sk_write_space(sk);
1237 	/*
1238 	 * if sk_wmem_alloc reached 0, we are last user and should
1239 	 * free this sock, as sk_free() call could not do it.
1240 	 */
1241 	if (res == 0)
1242 		__sk_free(sk);
1243 }
1244 EXPORT_SYMBOL(sock_wfree);
1245 
1246 /*
1247  * Read buffer destructor automatically called from kfree_skb.
1248  */
1249 void sock_rfree(struct sk_buff *skb)
1250 {
1251 	struct sock *sk = skb->sk;
1252 
1253 	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1254 	sk_mem_uncharge(skb->sk, skb->truesize);
1255 }
1256 EXPORT_SYMBOL(sock_rfree);
1257 
1258 
1259 int sock_i_uid(struct sock *sk)
1260 {
1261 	int uid;
1262 
1263 	read_lock(&sk->sk_callback_lock);
1264 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1265 	read_unlock(&sk->sk_callback_lock);
1266 	return uid;
1267 }
1268 EXPORT_SYMBOL(sock_i_uid);
1269 
1270 unsigned long sock_i_ino(struct sock *sk)
1271 {
1272 	unsigned long ino;
1273 
1274 	read_lock(&sk->sk_callback_lock);
1275 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1276 	read_unlock(&sk->sk_callback_lock);
1277 	return ino;
1278 }
1279 EXPORT_SYMBOL(sock_i_ino);
1280 
1281 /*
1282  * Allocate a skb from the socket's send buffer.
1283  */
1284 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1285 			     gfp_t priority)
1286 {
1287 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1288 		struct sk_buff *skb = alloc_skb(size, priority);
1289 		if (skb) {
1290 			skb_set_owner_w(skb, sk);
1291 			return skb;
1292 		}
1293 	}
1294 	return NULL;
1295 }
1296 EXPORT_SYMBOL(sock_wmalloc);
1297 
1298 /*
1299  * Allocate a skb from the socket's receive buffer.
1300  */
1301 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1302 			     gfp_t priority)
1303 {
1304 	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1305 		struct sk_buff *skb = alloc_skb(size, priority);
1306 		if (skb) {
1307 			skb_set_owner_r(skb, sk);
1308 			return skb;
1309 		}
1310 	}
1311 	return NULL;
1312 }
1313 
1314 /*
1315  * Allocate a memory block from the socket's option memory buffer.
1316  */
1317 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1318 {
1319 	if ((unsigned)size <= sysctl_optmem_max &&
1320 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1321 		void *mem;
1322 		/* First do the add, to avoid the race if kmalloc
1323 		 * might sleep.
1324 		 */
1325 		atomic_add(size, &sk->sk_omem_alloc);
1326 		mem = kmalloc(size, priority);
1327 		if (mem)
1328 			return mem;
1329 		atomic_sub(size, &sk->sk_omem_alloc);
1330 	}
1331 	return NULL;
1332 }
1333 EXPORT_SYMBOL(sock_kmalloc);
1334 
1335 /*
1336  * Free an option memory block.
1337  */
1338 void sock_kfree_s(struct sock *sk, void *mem, int size)
1339 {
1340 	kfree(mem);
1341 	atomic_sub(size, &sk->sk_omem_alloc);
1342 }
1343 EXPORT_SYMBOL(sock_kfree_s);
1344 
1345 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1346    I think, these locks should be removed for datagram sockets.
1347  */
1348 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1349 {
1350 	DEFINE_WAIT(wait);
1351 
1352 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1353 	for (;;) {
1354 		if (!timeo)
1355 			break;
1356 		if (signal_pending(current))
1357 			break;
1358 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1359 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1360 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1361 			break;
1362 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1363 			break;
1364 		if (sk->sk_err)
1365 			break;
1366 		timeo = schedule_timeout(timeo);
1367 	}
1368 	finish_wait(sk->sk_sleep, &wait);
1369 	return timeo;
1370 }
1371 
1372 
1373 /*
1374  *	Generic send/receive buffer handlers
1375  */
1376 
1377 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1378 				     unsigned long data_len, int noblock,
1379 				     int *errcode)
1380 {
1381 	struct sk_buff *skb;
1382 	gfp_t gfp_mask;
1383 	long timeo;
1384 	int err;
1385 
1386 	gfp_mask = sk->sk_allocation;
1387 	if (gfp_mask & __GFP_WAIT)
1388 		gfp_mask |= __GFP_REPEAT;
1389 
1390 	timeo = sock_sndtimeo(sk, noblock);
1391 	while (1) {
1392 		err = sock_error(sk);
1393 		if (err != 0)
1394 			goto failure;
1395 
1396 		err = -EPIPE;
1397 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1398 			goto failure;
1399 
1400 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1401 			skb = alloc_skb(header_len, gfp_mask);
1402 			if (skb) {
1403 				int npages;
1404 				int i;
1405 
1406 				/* No pages, we're done... */
1407 				if (!data_len)
1408 					break;
1409 
1410 				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1411 				skb->truesize += data_len;
1412 				skb_shinfo(skb)->nr_frags = npages;
1413 				for (i = 0; i < npages; i++) {
1414 					struct page *page;
1415 					skb_frag_t *frag;
1416 
1417 					page = alloc_pages(sk->sk_allocation, 0);
1418 					if (!page) {
1419 						err = -ENOBUFS;
1420 						skb_shinfo(skb)->nr_frags = i;
1421 						kfree_skb(skb);
1422 						goto failure;
1423 					}
1424 
1425 					frag = &skb_shinfo(skb)->frags[i];
1426 					frag->page = page;
1427 					frag->page_offset = 0;
1428 					frag->size = (data_len >= PAGE_SIZE ?
1429 						      PAGE_SIZE :
1430 						      data_len);
1431 					data_len -= PAGE_SIZE;
1432 				}
1433 
1434 				/* Full success... */
1435 				break;
1436 			}
1437 			err = -ENOBUFS;
1438 			goto failure;
1439 		}
1440 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1441 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1442 		err = -EAGAIN;
1443 		if (!timeo)
1444 			goto failure;
1445 		if (signal_pending(current))
1446 			goto interrupted;
1447 		timeo = sock_wait_for_wmem(sk, timeo);
1448 	}
1449 
1450 	skb_set_owner_w(skb, sk);
1451 	return skb;
1452 
1453 interrupted:
1454 	err = sock_intr_errno(timeo);
1455 failure:
1456 	*errcode = err;
1457 	return NULL;
1458 }
1459 EXPORT_SYMBOL(sock_alloc_send_pskb);
1460 
1461 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1462 				    int noblock, int *errcode)
1463 {
1464 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1465 }
1466 EXPORT_SYMBOL(sock_alloc_send_skb);
1467 
1468 static void __lock_sock(struct sock *sk)
1469 {
1470 	DEFINE_WAIT(wait);
1471 
1472 	for (;;) {
1473 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1474 					TASK_UNINTERRUPTIBLE);
1475 		spin_unlock_bh(&sk->sk_lock.slock);
1476 		schedule();
1477 		spin_lock_bh(&sk->sk_lock.slock);
1478 		if (!sock_owned_by_user(sk))
1479 			break;
1480 	}
1481 	finish_wait(&sk->sk_lock.wq, &wait);
1482 }
1483 
1484 static void __release_sock(struct sock *sk)
1485 {
1486 	struct sk_buff *skb = sk->sk_backlog.head;
1487 
1488 	do {
1489 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1490 		bh_unlock_sock(sk);
1491 
1492 		do {
1493 			struct sk_buff *next = skb->next;
1494 
1495 			skb->next = NULL;
1496 			sk_backlog_rcv(sk, skb);
1497 
1498 			/*
1499 			 * We are in process context here with softirqs
1500 			 * disabled, use cond_resched_softirq() to preempt.
1501 			 * This is safe to do because we've taken the backlog
1502 			 * queue private:
1503 			 */
1504 			cond_resched_softirq();
1505 
1506 			skb = next;
1507 		} while (skb != NULL);
1508 
1509 		bh_lock_sock(sk);
1510 	} while ((skb = sk->sk_backlog.head) != NULL);
1511 }
1512 
1513 /**
1514  * sk_wait_data - wait for data to arrive at sk_receive_queue
1515  * @sk:    sock to wait on
1516  * @timeo: for how long
1517  *
1518  * Now socket state including sk->sk_err is changed only under lock,
1519  * hence we may omit checks after joining wait queue.
1520  * We check receive queue before schedule() only as optimization;
1521  * it is very likely that release_sock() added new data.
1522  */
1523 int sk_wait_data(struct sock *sk, long *timeo)
1524 {
1525 	int rc;
1526 	DEFINE_WAIT(wait);
1527 
1528 	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1529 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1530 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1531 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1532 	finish_wait(sk->sk_sleep, &wait);
1533 	return rc;
1534 }
1535 EXPORT_SYMBOL(sk_wait_data);
1536 
1537 /**
1538  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1539  *	@sk: socket
1540  *	@size: memory size to allocate
1541  *	@kind: allocation type
1542  *
1543  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1544  *	rmem allocation. This function assumes that protocols which have
1545  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1546  */
1547 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1548 {
1549 	struct proto *prot = sk->sk_prot;
1550 	int amt = sk_mem_pages(size);
1551 	int allocated;
1552 
1553 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1554 	allocated = atomic_add_return(amt, prot->memory_allocated);
1555 
1556 	/* Under limit. */
1557 	if (allocated <= prot->sysctl_mem[0]) {
1558 		if (prot->memory_pressure && *prot->memory_pressure)
1559 			*prot->memory_pressure = 0;
1560 		return 1;
1561 	}
1562 
1563 	/* Under pressure. */
1564 	if (allocated > prot->sysctl_mem[1])
1565 		if (prot->enter_memory_pressure)
1566 			prot->enter_memory_pressure(sk);
1567 
1568 	/* Over hard limit. */
1569 	if (allocated > prot->sysctl_mem[2])
1570 		goto suppress_allocation;
1571 
1572 	/* guarantee minimum buffer size under pressure */
1573 	if (kind == SK_MEM_RECV) {
1574 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1575 			return 1;
1576 	} else { /* SK_MEM_SEND */
1577 		if (sk->sk_type == SOCK_STREAM) {
1578 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1579 				return 1;
1580 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1581 			   prot->sysctl_wmem[0])
1582 				return 1;
1583 	}
1584 
1585 	if (prot->memory_pressure) {
1586 		int alloc;
1587 
1588 		if (!*prot->memory_pressure)
1589 			return 1;
1590 		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1591 		if (prot->sysctl_mem[2] > alloc *
1592 		    sk_mem_pages(sk->sk_wmem_queued +
1593 				 atomic_read(&sk->sk_rmem_alloc) +
1594 				 sk->sk_forward_alloc))
1595 			return 1;
1596 	}
1597 
1598 suppress_allocation:
1599 
1600 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1601 		sk_stream_moderate_sndbuf(sk);
1602 
1603 		/* Fail only if socket is _under_ its sndbuf.
1604 		 * In this case we cannot block, so that we have to fail.
1605 		 */
1606 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1607 			return 1;
1608 	}
1609 
1610 	/* Alas. Undo changes. */
1611 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1612 	atomic_sub(amt, prot->memory_allocated);
1613 	return 0;
1614 }
1615 EXPORT_SYMBOL(__sk_mem_schedule);
1616 
1617 /**
1618  *	__sk_reclaim - reclaim memory_allocated
1619  *	@sk: socket
1620  */
1621 void __sk_mem_reclaim(struct sock *sk)
1622 {
1623 	struct proto *prot = sk->sk_prot;
1624 
1625 	atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1626 		   prot->memory_allocated);
1627 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1628 
1629 	if (prot->memory_pressure && *prot->memory_pressure &&
1630 	    (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1631 		*prot->memory_pressure = 0;
1632 }
1633 EXPORT_SYMBOL(__sk_mem_reclaim);
1634 
1635 
1636 /*
1637  * Set of default routines for initialising struct proto_ops when
1638  * the protocol does not support a particular function. In certain
1639  * cases where it makes no sense for a protocol to have a "do nothing"
1640  * function, some default processing is provided.
1641  */
1642 
1643 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1644 {
1645 	return -EOPNOTSUPP;
1646 }
1647 EXPORT_SYMBOL(sock_no_bind);
1648 
1649 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1650 		    int len, int flags)
1651 {
1652 	return -EOPNOTSUPP;
1653 }
1654 EXPORT_SYMBOL(sock_no_connect);
1655 
1656 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1657 {
1658 	return -EOPNOTSUPP;
1659 }
1660 EXPORT_SYMBOL(sock_no_socketpair);
1661 
1662 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1663 {
1664 	return -EOPNOTSUPP;
1665 }
1666 EXPORT_SYMBOL(sock_no_accept);
1667 
1668 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1669 		    int *len, int peer)
1670 {
1671 	return -EOPNOTSUPP;
1672 }
1673 EXPORT_SYMBOL(sock_no_getname);
1674 
1675 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1676 {
1677 	return 0;
1678 }
1679 EXPORT_SYMBOL(sock_no_poll);
1680 
1681 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1682 {
1683 	return -EOPNOTSUPP;
1684 }
1685 EXPORT_SYMBOL(sock_no_ioctl);
1686 
1687 int sock_no_listen(struct socket *sock, int backlog)
1688 {
1689 	return -EOPNOTSUPP;
1690 }
1691 EXPORT_SYMBOL(sock_no_listen);
1692 
1693 int sock_no_shutdown(struct socket *sock, int how)
1694 {
1695 	return -EOPNOTSUPP;
1696 }
1697 EXPORT_SYMBOL(sock_no_shutdown);
1698 
1699 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1700 		    char __user *optval, int optlen)
1701 {
1702 	return -EOPNOTSUPP;
1703 }
1704 EXPORT_SYMBOL(sock_no_setsockopt);
1705 
1706 int sock_no_getsockopt(struct socket *sock, int level, int optname,
1707 		    char __user *optval, int __user *optlen)
1708 {
1709 	return -EOPNOTSUPP;
1710 }
1711 EXPORT_SYMBOL(sock_no_getsockopt);
1712 
1713 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1714 		    size_t len)
1715 {
1716 	return -EOPNOTSUPP;
1717 }
1718 EXPORT_SYMBOL(sock_no_sendmsg);
1719 
1720 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1721 		    size_t len, int flags)
1722 {
1723 	return -EOPNOTSUPP;
1724 }
1725 EXPORT_SYMBOL(sock_no_recvmsg);
1726 
1727 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1728 {
1729 	/* Mirror missing mmap method error code */
1730 	return -ENODEV;
1731 }
1732 EXPORT_SYMBOL(sock_no_mmap);
1733 
1734 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1735 {
1736 	ssize_t res;
1737 	struct msghdr msg = {.msg_flags = flags};
1738 	struct kvec iov;
1739 	char *kaddr = kmap(page);
1740 	iov.iov_base = kaddr + offset;
1741 	iov.iov_len = size;
1742 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1743 	kunmap(page);
1744 	return res;
1745 }
1746 EXPORT_SYMBOL(sock_no_sendpage);
1747 
1748 /*
1749  *	Default Socket Callbacks
1750  */
1751 
1752 static void sock_def_wakeup(struct sock *sk)
1753 {
1754 	read_lock(&sk->sk_callback_lock);
1755 	if (sk_has_sleeper(sk))
1756 		wake_up_interruptible_all(sk->sk_sleep);
1757 	read_unlock(&sk->sk_callback_lock);
1758 }
1759 
1760 static void sock_def_error_report(struct sock *sk)
1761 {
1762 	read_lock(&sk->sk_callback_lock);
1763 	if (sk_has_sleeper(sk))
1764 		wake_up_interruptible_poll(sk->sk_sleep, POLLERR);
1765 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1766 	read_unlock(&sk->sk_callback_lock);
1767 }
1768 
1769 static void sock_def_readable(struct sock *sk, int len)
1770 {
1771 	read_lock(&sk->sk_callback_lock);
1772 	if (sk_has_sleeper(sk))
1773 		wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN |
1774 						POLLRDNORM | POLLRDBAND);
1775 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1776 	read_unlock(&sk->sk_callback_lock);
1777 }
1778 
1779 static void sock_def_write_space(struct sock *sk)
1780 {
1781 	read_lock(&sk->sk_callback_lock);
1782 
1783 	/* Do not wake up a writer until he can make "significant"
1784 	 * progress.  --DaveM
1785 	 */
1786 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1787 		if (sk_has_sleeper(sk))
1788 			wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
1789 						POLLWRNORM | POLLWRBAND);
1790 
1791 		/* Should agree with poll, otherwise some programs break */
1792 		if (sock_writeable(sk))
1793 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1794 	}
1795 
1796 	read_unlock(&sk->sk_callback_lock);
1797 }
1798 
1799 static void sock_def_destruct(struct sock *sk)
1800 {
1801 	kfree(sk->sk_protinfo);
1802 }
1803 
1804 void sk_send_sigurg(struct sock *sk)
1805 {
1806 	if (sk->sk_socket && sk->sk_socket->file)
1807 		if (send_sigurg(&sk->sk_socket->file->f_owner))
1808 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1809 }
1810 EXPORT_SYMBOL(sk_send_sigurg);
1811 
1812 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1813 		    unsigned long expires)
1814 {
1815 	if (!mod_timer(timer, expires))
1816 		sock_hold(sk);
1817 }
1818 EXPORT_SYMBOL(sk_reset_timer);
1819 
1820 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1821 {
1822 	if (timer_pending(timer) && del_timer(timer))
1823 		__sock_put(sk);
1824 }
1825 EXPORT_SYMBOL(sk_stop_timer);
1826 
1827 void sock_init_data(struct socket *sock, struct sock *sk)
1828 {
1829 	skb_queue_head_init(&sk->sk_receive_queue);
1830 	skb_queue_head_init(&sk->sk_write_queue);
1831 	skb_queue_head_init(&sk->sk_error_queue);
1832 #ifdef CONFIG_NET_DMA
1833 	skb_queue_head_init(&sk->sk_async_wait_queue);
1834 #endif
1835 
1836 	sk->sk_send_head	=	NULL;
1837 
1838 	init_timer(&sk->sk_timer);
1839 
1840 	sk->sk_allocation	=	GFP_KERNEL;
1841 	sk->sk_rcvbuf		=	sysctl_rmem_default;
1842 	sk->sk_sndbuf		=	sysctl_wmem_default;
1843 	sk->sk_state		=	TCP_CLOSE;
1844 	sk_set_socket(sk, sock);
1845 
1846 	sock_set_flag(sk, SOCK_ZAPPED);
1847 
1848 	if (sock) {
1849 		sk->sk_type	=	sock->type;
1850 		sk->sk_sleep	=	&sock->wait;
1851 		sock->sk	=	sk;
1852 	} else
1853 		sk->sk_sleep	=	NULL;
1854 
1855 	rwlock_init(&sk->sk_dst_lock);
1856 	rwlock_init(&sk->sk_callback_lock);
1857 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1858 			af_callback_keys + sk->sk_family,
1859 			af_family_clock_key_strings[sk->sk_family]);
1860 
1861 	sk->sk_state_change	=	sock_def_wakeup;
1862 	sk->sk_data_ready	=	sock_def_readable;
1863 	sk->sk_write_space	=	sock_def_write_space;
1864 	sk->sk_error_report	=	sock_def_error_report;
1865 	sk->sk_destruct		=	sock_def_destruct;
1866 
1867 	sk->sk_sndmsg_page	=	NULL;
1868 	sk->sk_sndmsg_off	=	0;
1869 
1870 	sk->sk_peercred.pid 	=	0;
1871 	sk->sk_peercred.uid	=	-1;
1872 	sk->sk_peercred.gid	=	-1;
1873 	sk->sk_write_pending	=	0;
1874 	sk->sk_rcvlowat		=	1;
1875 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1876 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1877 
1878 	sk->sk_stamp = ktime_set(-1L, 0);
1879 
1880 	/*
1881 	 * Before updating sk_refcnt, we must commit prior changes to memory
1882 	 * (Documentation/RCU/rculist_nulls.txt for details)
1883 	 */
1884 	smp_wmb();
1885 	atomic_set(&sk->sk_refcnt, 1);
1886 	atomic_set(&sk->sk_drops, 0);
1887 }
1888 EXPORT_SYMBOL(sock_init_data);
1889 
1890 void lock_sock_nested(struct sock *sk, int subclass)
1891 {
1892 	might_sleep();
1893 	spin_lock_bh(&sk->sk_lock.slock);
1894 	if (sk->sk_lock.owned)
1895 		__lock_sock(sk);
1896 	sk->sk_lock.owned = 1;
1897 	spin_unlock(&sk->sk_lock.slock);
1898 	/*
1899 	 * The sk_lock has mutex_lock() semantics here:
1900 	 */
1901 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
1902 	local_bh_enable();
1903 }
1904 EXPORT_SYMBOL(lock_sock_nested);
1905 
1906 void release_sock(struct sock *sk)
1907 {
1908 	/*
1909 	 * The sk_lock has mutex_unlock() semantics:
1910 	 */
1911 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1912 
1913 	spin_lock_bh(&sk->sk_lock.slock);
1914 	if (sk->sk_backlog.tail)
1915 		__release_sock(sk);
1916 	sk->sk_lock.owned = 0;
1917 	if (waitqueue_active(&sk->sk_lock.wq))
1918 		wake_up(&sk->sk_lock.wq);
1919 	spin_unlock_bh(&sk->sk_lock.slock);
1920 }
1921 EXPORT_SYMBOL(release_sock);
1922 
1923 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1924 {
1925 	struct timeval tv;
1926 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1927 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1928 	tv = ktime_to_timeval(sk->sk_stamp);
1929 	if (tv.tv_sec == -1)
1930 		return -ENOENT;
1931 	if (tv.tv_sec == 0) {
1932 		sk->sk_stamp = ktime_get_real();
1933 		tv = ktime_to_timeval(sk->sk_stamp);
1934 	}
1935 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
1936 }
1937 EXPORT_SYMBOL(sock_get_timestamp);
1938 
1939 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
1940 {
1941 	struct timespec ts;
1942 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1943 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1944 	ts = ktime_to_timespec(sk->sk_stamp);
1945 	if (ts.tv_sec == -1)
1946 		return -ENOENT;
1947 	if (ts.tv_sec == 0) {
1948 		sk->sk_stamp = ktime_get_real();
1949 		ts = ktime_to_timespec(sk->sk_stamp);
1950 	}
1951 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
1952 }
1953 EXPORT_SYMBOL(sock_get_timestampns);
1954 
1955 void sock_enable_timestamp(struct sock *sk, int flag)
1956 {
1957 	if (!sock_flag(sk, flag)) {
1958 		sock_set_flag(sk, flag);
1959 		/*
1960 		 * we just set one of the two flags which require net
1961 		 * time stamping, but time stamping might have been on
1962 		 * already because of the other one
1963 		 */
1964 		if (!sock_flag(sk,
1965 				flag == SOCK_TIMESTAMP ?
1966 				SOCK_TIMESTAMPING_RX_SOFTWARE :
1967 				SOCK_TIMESTAMP))
1968 			net_enable_timestamp();
1969 	}
1970 }
1971 
1972 /*
1973  *	Get a socket option on an socket.
1974  *
1975  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
1976  *	asynchronous errors should be reported by getsockopt. We assume
1977  *	this means if you specify SO_ERROR (otherwise whats the point of it).
1978  */
1979 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1980 			   char __user *optval, int __user *optlen)
1981 {
1982 	struct sock *sk = sock->sk;
1983 
1984 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
1985 }
1986 EXPORT_SYMBOL(sock_common_getsockopt);
1987 
1988 #ifdef CONFIG_COMPAT
1989 int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
1990 				  char __user *optval, int __user *optlen)
1991 {
1992 	struct sock *sk = sock->sk;
1993 
1994 	if (sk->sk_prot->compat_getsockopt != NULL)
1995 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
1996 						      optval, optlen);
1997 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
1998 }
1999 EXPORT_SYMBOL(compat_sock_common_getsockopt);
2000 #endif
2001 
2002 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2003 			struct msghdr *msg, size_t size, int flags)
2004 {
2005 	struct sock *sk = sock->sk;
2006 	int addr_len = 0;
2007 	int err;
2008 
2009 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2010 				   flags & ~MSG_DONTWAIT, &addr_len);
2011 	if (err >= 0)
2012 		msg->msg_namelen = addr_len;
2013 	return err;
2014 }
2015 EXPORT_SYMBOL(sock_common_recvmsg);
2016 
2017 /*
2018  *	Set socket options on an inet socket.
2019  */
2020 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2021 			   char __user *optval, int optlen)
2022 {
2023 	struct sock *sk = sock->sk;
2024 
2025 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2026 }
2027 EXPORT_SYMBOL(sock_common_setsockopt);
2028 
2029 #ifdef CONFIG_COMPAT
2030 int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2031 				  char __user *optval, int optlen)
2032 {
2033 	struct sock *sk = sock->sk;
2034 
2035 	if (sk->sk_prot->compat_setsockopt != NULL)
2036 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2037 						      optval, optlen);
2038 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2039 }
2040 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2041 #endif
2042 
2043 void sk_common_release(struct sock *sk)
2044 {
2045 	if (sk->sk_prot->destroy)
2046 		sk->sk_prot->destroy(sk);
2047 
2048 	/*
2049 	 * Observation: when sock_common_release is called, processes have
2050 	 * no access to socket. But net still has.
2051 	 * Step one, detach it from networking:
2052 	 *
2053 	 * A. Remove from hash tables.
2054 	 */
2055 
2056 	sk->sk_prot->unhash(sk);
2057 
2058 	/*
2059 	 * In this point socket cannot receive new packets, but it is possible
2060 	 * that some packets are in flight because some CPU runs receiver and
2061 	 * did hash table lookup before we unhashed socket. They will achieve
2062 	 * receive queue and will be purged by socket destructor.
2063 	 *
2064 	 * Also we still have packets pending on receive queue and probably,
2065 	 * our own packets waiting in device queues. sock_destroy will drain
2066 	 * receive queue, but transmitted packets will delay socket destruction
2067 	 * until the last reference will be released.
2068 	 */
2069 
2070 	sock_orphan(sk);
2071 
2072 	xfrm_sk_free_policy(sk);
2073 
2074 	sk_refcnt_debug_release(sk);
2075 	sock_put(sk);
2076 }
2077 EXPORT_SYMBOL(sk_common_release);
2078 
2079 static DEFINE_RWLOCK(proto_list_lock);
2080 static LIST_HEAD(proto_list);
2081 
2082 #ifdef CONFIG_PROC_FS
2083 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2084 struct prot_inuse {
2085 	int val[PROTO_INUSE_NR];
2086 };
2087 
2088 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2089 
2090 #ifdef CONFIG_NET_NS
2091 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2092 {
2093 	int cpu = smp_processor_id();
2094 	per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
2095 }
2096 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2097 
2098 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2099 {
2100 	int cpu, idx = prot->inuse_idx;
2101 	int res = 0;
2102 
2103 	for_each_possible_cpu(cpu)
2104 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2105 
2106 	return res >= 0 ? res : 0;
2107 }
2108 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2109 
2110 static int sock_inuse_init_net(struct net *net)
2111 {
2112 	net->core.inuse = alloc_percpu(struct prot_inuse);
2113 	return net->core.inuse ? 0 : -ENOMEM;
2114 }
2115 
2116 static void sock_inuse_exit_net(struct net *net)
2117 {
2118 	free_percpu(net->core.inuse);
2119 }
2120 
2121 static struct pernet_operations net_inuse_ops = {
2122 	.init = sock_inuse_init_net,
2123 	.exit = sock_inuse_exit_net,
2124 };
2125 
2126 static __init int net_inuse_init(void)
2127 {
2128 	if (register_pernet_subsys(&net_inuse_ops))
2129 		panic("Cannot initialize net inuse counters");
2130 
2131 	return 0;
2132 }
2133 
2134 core_initcall(net_inuse_init);
2135 #else
2136 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2137 
2138 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2139 {
2140 	__get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
2141 }
2142 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2143 
2144 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2145 {
2146 	int cpu, idx = prot->inuse_idx;
2147 	int res = 0;
2148 
2149 	for_each_possible_cpu(cpu)
2150 		res += per_cpu(prot_inuse, cpu).val[idx];
2151 
2152 	return res >= 0 ? res : 0;
2153 }
2154 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2155 #endif
2156 
2157 static void assign_proto_idx(struct proto *prot)
2158 {
2159 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2160 
2161 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2162 		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2163 		return;
2164 	}
2165 
2166 	set_bit(prot->inuse_idx, proto_inuse_idx);
2167 }
2168 
2169 static void release_proto_idx(struct proto *prot)
2170 {
2171 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2172 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2173 }
2174 #else
2175 static inline void assign_proto_idx(struct proto *prot)
2176 {
2177 }
2178 
2179 static inline void release_proto_idx(struct proto *prot)
2180 {
2181 }
2182 #endif
2183 
2184 int proto_register(struct proto *prot, int alloc_slab)
2185 {
2186 	if (alloc_slab) {
2187 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2188 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2189 					NULL);
2190 
2191 		if (prot->slab == NULL) {
2192 			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2193 			       prot->name);
2194 			goto out;
2195 		}
2196 
2197 		if (prot->rsk_prot != NULL) {
2198 			static const char mask[] = "request_sock_%s";
2199 
2200 			prot->rsk_prot->slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2201 			if (prot->rsk_prot->slab_name == NULL)
2202 				goto out_free_sock_slab;
2203 
2204 			sprintf(prot->rsk_prot->slab_name, mask, prot->name);
2205 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2206 								 prot->rsk_prot->obj_size, 0,
2207 								 SLAB_HWCACHE_ALIGN, NULL);
2208 
2209 			if (prot->rsk_prot->slab == NULL) {
2210 				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2211 				       prot->name);
2212 				goto out_free_request_sock_slab_name;
2213 			}
2214 		}
2215 
2216 		if (prot->twsk_prot != NULL) {
2217 			static const char mask[] = "tw_sock_%s";
2218 
2219 			prot->twsk_prot->twsk_slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2220 
2221 			if (prot->twsk_prot->twsk_slab_name == NULL)
2222 				goto out_free_request_sock_slab;
2223 
2224 			sprintf(prot->twsk_prot->twsk_slab_name, mask, prot->name);
2225 			prot->twsk_prot->twsk_slab =
2226 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2227 						  prot->twsk_prot->twsk_obj_size,
2228 						  0,
2229 						  SLAB_HWCACHE_ALIGN |
2230 							prot->slab_flags,
2231 						  NULL);
2232 			if (prot->twsk_prot->twsk_slab == NULL)
2233 				goto out_free_timewait_sock_slab_name;
2234 		}
2235 	}
2236 
2237 	write_lock(&proto_list_lock);
2238 	list_add(&prot->node, &proto_list);
2239 	assign_proto_idx(prot);
2240 	write_unlock(&proto_list_lock);
2241 	return 0;
2242 
2243 out_free_timewait_sock_slab_name:
2244 	kfree(prot->twsk_prot->twsk_slab_name);
2245 out_free_request_sock_slab:
2246 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2247 		kmem_cache_destroy(prot->rsk_prot->slab);
2248 		prot->rsk_prot->slab = NULL;
2249 	}
2250 out_free_request_sock_slab_name:
2251 	kfree(prot->rsk_prot->slab_name);
2252 out_free_sock_slab:
2253 	kmem_cache_destroy(prot->slab);
2254 	prot->slab = NULL;
2255 out:
2256 	return -ENOBUFS;
2257 }
2258 EXPORT_SYMBOL(proto_register);
2259 
2260 void proto_unregister(struct proto *prot)
2261 {
2262 	write_lock(&proto_list_lock);
2263 	release_proto_idx(prot);
2264 	list_del(&prot->node);
2265 	write_unlock(&proto_list_lock);
2266 
2267 	if (prot->slab != NULL) {
2268 		kmem_cache_destroy(prot->slab);
2269 		prot->slab = NULL;
2270 	}
2271 
2272 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2273 		kmem_cache_destroy(prot->rsk_prot->slab);
2274 		kfree(prot->rsk_prot->slab_name);
2275 		prot->rsk_prot->slab = NULL;
2276 	}
2277 
2278 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2279 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2280 		kfree(prot->twsk_prot->twsk_slab_name);
2281 		prot->twsk_prot->twsk_slab = NULL;
2282 	}
2283 }
2284 EXPORT_SYMBOL(proto_unregister);
2285 
2286 #ifdef CONFIG_PROC_FS
2287 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2288 	__acquires(proto_list_lock)
2289 {
2290 	read_lock(&proto_list_lock);
2291 	return seq_list_start_head(&proto_list, *pos);
2292 }
2293 
2294 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2295 {
2296 	return seq_list_next(v, &proto_list, pos);
2297 }
2298 
2299 static void proto_seq_stop(struct seq_file *seq, void *v)
2300 	__releases(proto_list_lock)
2301 {
2302 	read_unlock(&proto_list_lock);
2303 }
2304 
2305 static char proto_method_implemented(const void *method)
2306 {
2307 	return method == NULL ? 'n' : 'y';
2308 }
2309 
2310 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2311 {
2312 	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
2313 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2314 		   proto->name,
2315 		   proto->obj_size,
2316 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2317 		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
2318 		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2319 		   proto->max_header,
2320 		   proto->slab == NULL ? "no" : "yes",
2321 		   module_name(proto->owner),
2322 		   proto_method_implemented(proto->close),
2323 		   proto_method_implemented(proto->connect),
2324 		   proto_method_implemented(proto->disconnect),
2325 		   proto_method_implemented(proto->accept),
2326 		   proto_method_implemented(proto->ioctl),
2327 		   proto_method_implemented(proto->init),
2328 		   proto_method_implemented(proto->destroy),
2329 		   proto_method_implemented(proto->shutdown),
2330 		   proto_method_implemented(proto->setsockopt),
2331 		   proto_method_implemented(proto->getsockopt),
2332 		   proto_method_implemented(proto->sendmsg),
2333 		   proto_method_implemented(proto->recvmsg),
2334 		   proto_method_implemented(proto->sendpage),
2335 		   proto_method_implemented(proto->bind),
2336 		   proto_method_implemented(proto->backlog_rcv),
2337 		   proto_method_implemented(proto->hash),
2338 		   proto_method_implemented(proto->unhash),
2339 		   proto_method_implemented(proto->get_port),
2340 		   proto_method_implemented(proto->enter_memory_pressure));
2341 }
2342 
2343 static int proto_seq_show(struct seq_file *seq, void *v)
2344 {
2345 	if (v == &proto_list)
2346 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2347 			   "protocol",
2348 			   "size",
2349 			   "sockets",
2350 			   "memory",
2351 			   "press",
2352 			   "maxhdr",
2353 			   "slab",
2354 			   "module",
2355 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2356 	else
2357 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2358 	return 0;
2359 }
2360 
2361 static const struct seq_operations proto_seq_ops = {
2362 	.start  = proto_seq_start,
2363 	.next   = proto_seq_next,
2364 	.stop   = proto_seq_stop,
2365 	.show   = proto_seq_show,
2366 };
2367 
2368 static int proto_seq_open(struct inode *inode, struct file *file)
2369 {
2370 	return seq_open_net(inode, file, &proto_seq_ops,
2371 			    sizeof(struct seq_net_private));
2372 }
2373 
2374 static const struct file_operations proto_seq_fops = {
2375 	.owner		= THIS_MODULE,
2376 	.open		= proto_seq_open,
2377 	.read		= seq_read,
2378 	.llseek		= seq_lseek,
2379 	.release	= seq_release_net,
2380 };
2381 
2382 static __net_init int proto_init_net(struct net *net)
2383 {
2384 	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2385 		return -ENOMEM;
2386 
2387 	return 0;
2388 }
2389 
2390 static __net_exit void proto_exit_net(struct net *net)
2391 {
2392 	proc_net_remove(net, "protocols");
2393 }
2394 
2395 
2396 static __net_initdata struct pernet_operations proto_net_ops = {
2397 	.init = proto_init_net,
2398 	.exit = proto_exit_net,
2399 };
2400 
2401 static int __init proto_init(void)
2402 {
2403 	return register_pernet_subsys(&proto_net_ops);
2404 }
2405 
2406 subsys_initcall(proto_init);
2407 
2408 #endif /* PROC_FS */
2409