xref: /linux/net/core/sock.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
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 *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 *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 *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_ERROR:
486 		ret = -ENOPROTOOPT;
487 		break;
488 	case SO_DONTROUTE:
489 		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
490 		break;
491 	case SO_BROADCAST:
492 		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
493 		break;
494 	case SO_SNDBUF:
495 		/* Don't error on this BSD doesn't and if you think
496 		   about it this is right. Otherwise apps have to
497 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
498 		   are treated in BSD as hints */
499 
500 		if (val > sysctl_wmem_max)
501 			val = sysctl_wmem_max;
502 set_sndbuf:
503 		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
504 		if ((val * 2) < SOCK_MIN_SNDBUF)
505 			sk->sk_sndbuf = SOCK_MIN_SNDBUF;
506 		else
507 			sk->sk_sndbuf = val * 2;
508 
509 		/*
510 		 *	Wake up sending tasks if we
511 		 *	upped the value.
512 		 */
513 		sk->sk_write_space(sk);
514 		break;
515 
516 	case SO_SNDBUFFORCE:
517 		if (!capable(CAP_NET_ADMIN)) {
518 			ret = -EPERM;
519 			break;
520 		}
521 		goto set_sndbuf;
522 
523 	case SO_RCVBUF:
524 		/* Don't error on this BSD doesn't and if you think
525 		   about it this is right. Otherwise apps have to
526 		   play 'guess the biggest size' games. RCVBUF/SNDBUF
527 		   are treated in BSD as hints */
528 
529 		if (val > sysctl_rmem_max)
530 			val = sysctl_rmem_max;
531 set_rcvbuf:
532 		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
533 		/*
534 		 * We double it on the way in to account for
535 		 * "struct sk_buff" etc. overhead.   Applications
536 		 * assume that the SO_RCVBUF setting they make will
537 		 * allow that much actual data to be received on that
538 		 * socket.
539 		 *
540 		 * Applications are unaware that "struct sk_buff" and
541 		 * other overheads allocate from the receive buffer
542 		 * during socket buffer allocation.
543 		 *
544 		 * And after considering the possible alternatives,
545 		 * returning the value we actually used in getsockopt
546 		 * is the most desirable behavior.
547 		 */
548 		if ((val * 2) < SOCK_MIN_RCVBUF)
549 			sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
550 		else
551 			sk->sk_rcvbuf = val * 2;
552 		break;
553 
554 	case SO_RCVBUFFORCE:
555 		if (!capable(CAP_NET_ADMIN)) {
556 			ret = -EPERM;
557 			break;
558 		}
559 		goto set_rcvbuf;
560 
561 	case SO_KEEPALIVE:
562 #ifdef CONFIG_INET
563 		if (sk->sk_protocol == IPPROTO_TCP)
564 			tcp_set_keepalive(sk, valbool);
565 #endif
566 		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
567 		break;
568 
569 	case SO_OOBINLINE:
570 		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
571 		break;
572 
573 	case SO_NO_CHECK:
574 		sk->sk_no_check = valbool;
575 		break;
576 
577 	case SO_PRIORITY:
578 		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
579 			sk->sk_priority = val;
580 		else
581 			ret = -EPERM;
582 		break;
583 
584 	case SO_LINGER:
585 		if (optlen < sizeof(ling)) {
586 			ret = -EINVAL;	/* 1003.1g */
587 			break;
588 		}
589 		if (copy_from_user(&ling, optval, sizeof(ling))) {
590 			ret = -EFAULT;
591 			break;
592 		}
593 		if (!ling.l_onoff)
594 			sock_reset_flag(sk, SOCK_LINGER);
595 		else {
596 #if (BITS_PER_LONG == 32)
597 			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
598 				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
599 			else
600 #endif
601 				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
602 			sock_set_flag(sk, SOCK_LINGER);
603 		}
604 		break;
605 
606 	case SO_BSDCOMPAT:
607 		sock_warn_obsolete_bsdism("setsockopt");
608 		break;
609 
610 	case SO_PASSCRED:
611 		if (valbool)
612 			set_bit(SOCK_PASSCRED, &sock->flags);
613 		else
614 			clear_bit(SOCK_PASSCRED, &sock->flags);
615 		break;
616 
617 	case SO_TIMESTAMP:
618 	case SO_TIMESTAMPNS:
619 		if (valbool)  {
620 			if (optname == SO_TIMESTAMP)
621 				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
622 			else
623 				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
624 			sock_set_flag(sk, SOCK_RCVTSTAMP);
625 			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
626 		} else {
627 			sock_reset_flag(sk, SOCK_RCVTSTAMP);
628 			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
629 		}
630 		break;
631 
632 	case SO_TIMESTAMPING:
633 		if (val & ~SOF_TIMESTAMPING_MASK) {
634 			ret = -EINVAL;
635 			break;
636 		}
637 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
638 				  val & SOF_TIMESTAMPING_TX_HARDWARE);
639 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
640 				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
641 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
642 				  val & SOF_TIMESTAMPING_RX_HARDWARE);
643 		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
644 			sock_enable_timestamp(sk,
645 					      SOCK_TIMESTAMPING_RX_SOFTWARE);
646 		else
647 			sock_disable_timestamp(sk,
648 					       SOCK_TIMESTAMPING_RX_SOFTWARE);
649 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
650 				  val & SOF_TIMESTAMPING_SOFTWARE);
651 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
652 				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
653 		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
654 				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
655 		break;
656 
657 	case SO_RCVLOWAT:
658 		if (val < 0)
659 			val = INT_MAX;
660 		sk->sk_rcvlowat = val ? : 1;
661 		break;
662 
663 	case SO_RCVTIMEO:
664 		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
665 		break;
666 
667 	case SO_SNDTIMEO:
668 		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
669 		break;
670 
671 	case SO_ATTACH_FILTER:
672 		ret = -EINVAL;
673 		if (optlen == sizeof(struct sock_fprog)) {
674 			struct sock_fprog fprog;
675 
676 			ret = -EFAULT;
677 			if (copy_from_user(&fprog, optval, sizeof(fprog)))
678 				break;
679 
680 			ret = sk_attach_filter(&fprog, sk);
681 		}
682 		break;
683 
684 	case SO_DETACH_FILTER:
685 		ret = sk_detach_filter(sk);
686 		break;
687 
688 	case SO_PASSSEC:
689 		if (valbool)
690 			set_bit(SOCK_PASSSEC, &sock->flags);
691 		else
692 			clear_bit(SOCK_PASSSEC, &sock->flags);
693 		break;
694 	case SO_MARK:
695 		if (!capable(CAP_NET_ADMIN))
696 			ret = -EPERM;
697 		else
698 			sk->sk_mark = val;
699 		break;
700 
701 		/* We implement the SO_SNDLOWAT etc to
702 		   not be settable (1003.1g 5.3) */
703 	default:
704 		ret = -ENOPROTOOPT;
705 		break;
706 	}
707 	release_sock(sk);
708 	return ret;
709 }
710 EXPORT_SYMBOL(sock_setsockopt);
711 
712 
713 int sock_getsockopt(struct socket *sock, int level, int optname,
714 		    char __user *optval, int __user *optlen)
715 {
716 	struct sock *sk = sock->sk;
717 
718 	union {
719 		int val;
720 		struct linger ling;
721 		struct timeval tm;
722 	} v;
723 
724 	unsigned int lv = sizeof(int);
725 	int len;
726 
727 	if (get_user(len, optlen))
728 		return -EFAULT;
729 	if (len < 0)
730 		return -EINVAL;
731 
732 	memset(&v, 0, sizeof(v));
733 
734 	switch (optname) {
735 	case SO_DEBUG:
736 		v.val = sock_flag(sk, SOCK_DBG);
737 		break;
738 
739 	case SO_DONTROUTE:
740 		v.val = sock_flag(sk, SOCK_LOCALROUTE);
741 		break;
742 
743 	case SO_BROADCAST:
744 		v.val = !!sock_flag(sk, SOCK_BROADCAST);
745 		break;
746 
747 	case SO_SNDBUF:
748 		v.val = sk->sk_sndbuf;
749 		break;
750 
751 	case SO_RCVBUF:
752 		v.val = sk->sk_rcvbuf;
753 		break;
754 
755 	case SO_REUSEADDR:
756 		v.val = sk->sk_reuse;
757 		break;
758 
759 	case SO_KEEPALIVE:
760 		v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
761 		break;
762 
763 	case SO_TYPE:
764 		v.val = sk->sk_type;
765 		break;
766 
767 	case SO_ERROR:
768 		v.val = -sock_error(sk);
769 		if (v.val == 0)
770 			v.val = xchg(&sk->sk_err_soft, 0);
771 		break;
772 
773 	case SO_OOBINLINE:
774 		v.val = !!sock_flag(sk, SOCK_URGINLINE);
775 		break;
776 
777 	case SO_NO_CHECK:
778 		v.val = sk->sk_no_check;
779 		break;
780 
781 	case SO_PRIORITY:
782 		v.val = sk->sk_priority;
783 		break;
784 
785 	case SO_LINGER:
786 		lv		= sizeof(v.ling);
787 		v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
788 		v.ling.l_linger	= sk->sk_lingertime / HZ;
789 		break;
790 
791 	case SO_BSDCOMPAT:
792 		sock_warn_obsolete_bsdism("getsockopt");
793 		break;
794 
795 	case SO_TIMESTAMP:
796 		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
797 				!sock_flag(sk, SOCK_RCVTSTAMPNS);
798 		break;
799 
800 	case SO_TIMESTAMPNS:
801 		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
802 		break;
803 
804 	case SO_TIMESTAMPING:
805 		v.val = 0;
806 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
807 			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
808 		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
809 			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
810 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
811 			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
812 		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
813 			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
814 		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
815 			v.val |= SOF_TIMESTAMPING_SOFTWARE;
816 		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
817 			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
818 		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
819 			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
820 		break;
821 
822 	case SO_RCVTIMEO:
823 		lv = sizeof(struct timeval);
824 		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
825 			v.tm.tv_sec = 0;
826 			v.tm.tv_usec = 0;
827 		} else {
828 			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
829 			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
830 		}
831 		break;
832 
833 	case SO_SNDTIMEO:
834 		lv = sizeof(struct timeval);
835 		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
836 			v.tm.tv_sec = 0;
837 			v.tm.tv_usec = 0;
838 		} else {
839 			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
840 			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
841 		}
842 		break;
843 
844 	case SO_RCVLOWAT:
845 		v.val = sk->sk_rcvlowat;
846 		break;
847 
848 	case SO_SNDLOWAT:
849 		v.val = 1;
850 		break;
851 
852 	case SO_PASSCRED:
853 		v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
854 		break;
855 
856 	case SO_PEERCRED:
857 		if (len > sizeof(sk->sk_peercred))
858 			len = sizeof(sk->sk_peercred);
859 		if (copy_to_user(optval, &sk->sk_peercred, len))
860 			return -EFAULT;
861 		goto lenout;
862 
863 	case SO_PEERNAME:
864 	{
865 		char address[128];
866 
867 		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
868 			return -ENOTCONN;
869 		if (lv < len)
870 			return -EINVAL;
871 		if (copy_to_user(optval, address, len))
872 			return -EFAULT;
873 		goto lenout;
874 	}
875 
876 	/* Dubious BSD thing... Probably nobody even uses it, but
877 	 * the UNIX standard wants it for whatever reason... -DaveM
878 	 */
879 	case SO_ACCEPTCONN:
880 		v.val = sk->sk_state == TCP_LISTEN;
881 		break;
882 
883 	case SO_PASSSEC:
884 		v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
885 		break;
886 
887 	case SO_PEERSEC:
888 		return security_socket_getpeersec_stream(sock, optval, optlen, len);
889 
890 	case SO_MARK:
891 		v.val = sk->sk_mark;
892 		break;
893 
894 	default:
895 		return -ENOPROTOOPT;
896 	}
897 
898 	if (len > lv)
899 		len = lv;
900 	if (copy_to_user(optval, &v, len))
901 		return -EFAULT;
902 lenout:
903 	if (put_user(len, optlen))
904 		return -EFAULT;
905 	return 0;
906 }
907 
908 /*
909  * Initialize an sk_lock.
910  *
911  * (We also register the sk_lock with the lock validator.)
912  */
913 static inline void sock_lock_init(struct sock *sk)
914 {
915 	sock_lock_init_class_and_name(sk,
916 			af_family_slock_key_strings[sk->sk_family],
917 			af_family_slock_keys + sk->sk_family,
918 			af_family_key_strings[sk->sk_family],
919 			af_family_keys + sk->sk_family);
920 }
921 
922 /*
923  * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
924  * even temporarly, because of RCU lookups. sk_node should also be left as is.
925  */
926 static void sock_copy(struct sock *nsk, const struct sock *osk)
927 {
928 #ifdef CONFIG_SECURITY_NETWORK
929 	void *sptr = nsk->sk_security;
930 #endif
931 	BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) !=
932 		     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt));
933 	memcpy(&nsk->sk_copy_start, &osk->sk_copy_start,
934 	       osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start));
935 #ifdef CONFIG_SECURITY_NETWORK
936 	nsk->sk_security = sptr;
937 	security_sk_clone(osk, nsk);
938 #endif
939 }
940 
941 static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
942 		int family)
943 {
944 	struct sock *sk;
945 	struct kmem_cache *slab;
946 
947 	slab = prot->slab;
948 	if (slab != NULL) {
949 		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
950 		if (!sk)
951 			return sk;
952 		if (priority & __GFP_ZERO) {
953 			/*
954 			 * caches using SLAB_DESTROY_BY_RCU should let
955 			 * sk_node.next un-modified. Special care is taken
956 			 * when initializing object to zero.
957 			 */
958 			if (offsetof(struct sock, sk_node.next) != 0)
959 				memset(sk, 0, offsetof(struct sock, sk_node.next));
960 			memset(&sk->sk_node.pprev, 0,
961 			       prot->obj_size - offsetof(struct sock,
962 							 sk_node.pprev));
963 		}
964 	}
965 	else
966 		sk = kmalloc(prot->obj_size, priority);
967 
968 	if (sk != NULL) {
969 		kmemcheck_annotate_bitfield(sk, flags);
970 
971 		if (security_sk_alloc(sk, family, priority))
972 			goto out_free;
973 
974 		if (!try_module_get(prot->owner))
975 			goto out_free_sec;
976 	}
977 
978 	return sk;
979 
980 out_free_sec:
981 	security_sk_free(sk);
982 out_free:
983 	if (slab != NULL)
984 		kmem_cache_free(slab, sk);
985 	else
986 		kfree(sk);
987 	return NULL;
988 }
989 
990 static void sk_prot_free(struct proto *prot, struct sock *sk)
991 {
992 	struct kmem_cache *slab;
993 	struct module *owner;
994 
995 	owner = prot->owner;
996 	slab = prot->slab;
997 
998 	security_sk_free(sk);
999 	if (slab != NULL)
1000 		kmem_cache_free(slab, sk);
1001 	else
1002 		kfree(sk);
1003 	module_put(owner);
1004 }
1005 
1006 /**
1007  *	sk_alloc - All socket objects are allocated here
1008  *	@net: the applicable net namespace
1009  *	@family: protocol family
1010  *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1011  *	@prot: struct proto associated with this new sock instance
1012  */
1013 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1014 		      struct proto *prot)
1015 {
1016 	struct sock *sk;
1017 
1018 	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1019 	if (sk) {
1020 		sk->sk_family = family;
1021 		/*
1022 		 * See comment in struct sock definition to understand
1023 		 * why we need sk_prot_creator -acme
1024 		 */
1025 		sk->sk_prot = sk->sk_prot_creator = prot;
1026 		sock_lock_init(sk);
1027 		sock_net_set(sk, get_net(net));
1028 	}
1029 
1030 	return sk;
1031 }
1032 EXPORT_SYMBOL(sk_alloc);
1033 
1034 static void __sk_free(struct sock *sk)
1035 {
1036 	struct sk_filter *filter;
1037 
1038 	if (sk->sk_destruct)
1039 		sk->sk_destruct(sk);
1040 
1041 	filter = rcu_dereference(sk->sk_filter);
1042 	if (filter) {
1043 		sk_filter_uncharge(sk, filter);
1044 		rcu_assign_pointer(sk->sk_filter, NULL);
1045 	}
1046 
1047 	sock_disable_timestamp(sk, SOCK_TIMESTAMP);
1048 	sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
1049 
1050 	if (atomic_read(&sk->sk_omem_alloc))
1051 		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
1052 		       __func__, atomic_read(&sk->sk_omem_alloc));
1053 
1054 	put_net(sock_net(sk));
1055 	sk_prot_free(sk->sk_prot_creator, sk);
1056 }
1057 
1058 void sk_free(struct sock *sk)
1059 {
1060 	/*
1061 	 * We substract one from sk_wmem_alloc and can know if
1062 	 * some packets are still in some tx queue.
1063 	 * If not null, sock_wfree() will call __sk_free(sk) later
1064 	 */
1065 	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1066 		__sk_free(sk);
1067 }
1068 EXPORT_SYMBOL(sk_free);
1069 
1070 /*
1071  * Last sock_put should drop referrence to sk->sk_net. It has already
1072  * been dropped in sk_change_net. Taking referrence to stopping namespace
1073  * is not an option.
1074  * Take referrence to a socket to remove it from hash _alive_ and after that
1075  * destroy it in the context of init_net.
1076  */
1077 void sk_release_kernel(struct sock *sk)
1078 {
1079 	if (sk == NULL || sk->sk_socket == NULL)
1080 		return;
1081 
1082 	sock_hold(sk);
1083 	sock_release(sk->sk_socket);
1084 	release_net(sock_net(sk));
1085 	sock_net_set(sk, get_net(&init_net));
1086 	sock_put(sk);
1087 }
1088 EXPORT_SYMBOL(sk_release_kernel);
1089 
1090 struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1091 {
1092 	struct sock *newsk;
1093 
1094 	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1095 	if (newsk != NULL) {
1096 		struct sk_filter *filter;
1097 
1098 		sock_copy(newsk, sk);
1099 
1100 		/* SANITY */
1101 		get_net(sock_net(newsk));
1102 		sk_node_init(&newsk->sk_node);
1103 		sock_lock_init(newsk);
1104 		bh_lock_sock(newsk);
1105 		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1106 
1107 		atomic_set(&newsk->sk_rmem_alloc, 0);
1108 		/*
1109 		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1110 		 */
1111 		atomic_set(&newsk->sk_wmem_alloc, 1);
1112 		atomic_set(&newsk->sk_omem_alloc, 0);
1113 		skb_queue_head_init(&newsk->sk_receive_queue);
1114 		skb_queue_head_init(&newsk->sk_write_queue);
1115 #ifdef CONFIG_NET_DMA
1116 		skb_queue_head_init(&newsk->sk_async_wait_queue);
1117 #endif
1118 
1119 		rwlock_init(&newsk->sk_dst_lock);
1120 		rwlock_init(&newsk->sk_callback_lock);
1121 		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1122 				af_callback_keys + newsk->sk_family,
1123 				af_family_clock_key_strings[newsk->sk_family]);
1124 
1125 		newsk->sk_dst_cache	= NULL;
1126 		newsk->sk_wmem_queued	= 0;
1127 		newsk->sk_forward_alloc = 0;
1128 		newsk->sk_send_head	= NULL;
1129 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1130 
1131 		sock_reset_flag(newsk, SOCK_DONE);
1132 		skb_queue_head_init(&newsk->sk_error_queue);
1133 
1134 		filter = newsk->sk_filter;
1135 		if (filter != NULL)
1136 			sk_filter_charge(newsk, filter);
1137 
1138 		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1139 			/* It is still raw copy of parent, so invalidate
1140 			 * destructor and make plain sk_free() */
1141 			newsk->sk_destruct = NULL;
1142 			sk_free(newsk);
1143 			newsk = NULL;
1144 			goto out;
1145 		}
1146 
1147 		newsk->sk_err	   = 0;
1148 		newsk->sk_priority = 0;
1149 		/*
1150 		 * Before updating sk_refcnt, we must commit prior changes to memory
1151 		 * (Documentation/RCU/rculist_nulls.txt for details)
1152 		 */
1153 		smp_wmb();
1154 		atomic_set(&newsk->sk_refcnt, 2);
1155 
1156 		/*
1157 		 * Increment the counter in the same struct proto as the master
1158 		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1159 		 * is the same as sk->sk_prot->socks, as this field was copied
1160 		 * with memcpy).
1161 		 *
1162 		 * This _changes_ the previous behaviour, where
1163 		 * tcp_create_openreq_child always was incrementing the
1164 		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1165 		 * to be taken into account in all callers. -acme
1166 		 */
1167 		sk_refcnt_debug_inc(newsk);
1168 		sk_set_socket(newsk, NULL);
1169 		newsk->sk_sleep	 = NULL;
1170 
1171 		if (newsk->sk_prot->sockets_allocated)
1172 			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1173 	}
1174 out:
1175 	return newsk;
1176 }
1177 EXPORT_SYMBOL_GPL(sk_clone);
1178 
1179 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1180 {
1181 	__sk_dst_set(sk, dst);
1182 	sk->sk_route_caps = dst->dev->features;
1183 	if (sk->sk_route_caps & NETIF_F_GSO)
1184 		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1185 	if (sk_can_gso(sk)) {
1186 		if (dst->header_len) {
1187 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1188 		} else {
1189 			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1190 			sk->sk_gso_max_size = dst->dev->gso_max_size;
1191 		}
1192 	}
1193 }
1194 EXPORT_SYMBOL_GPL(sk_setup_caps);
1195 
1196 void __init sk_init(void)
1197 {
1198 	if (num_physpages <= 4096) {
1199 		sysctl_wmem_max = 32767;
1200 		sysctl_rmem_max = 32767;
1201 		sysctl_wmem_default = 32767;
1202 		sysctl_rmem_default = 32767;
1203 	} else if (num_physpages >= 131072) {
1204 		sysctl_wmem_max = 131071;
1205 		sysctl_rmem_max = 131071;
1206 	}
1207 }
1208 
1209 /*
1210  *	Simple resource managers for sockets.
1211  */
1212 
1213 
1214 /*
1215  * Write buffer destructor automatically called from kfree_skb.
1216  */
1217 void sock_wfree(struct sk_buff *skb)
1218 {
1219 	struct sock *sk = skb->sk;
1220 	int res;
1221 
1222 	/* In case it might be waiting for more memory. */
1223 	res = atomic_sub_return(skb->truesize, &sk->sk_wmem_alloc);
1224 	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE))
1225 		sk->sk_write_space(sk);
1226 	/*
1227 	 * if sk_wmem_alloc reached 0, we are last user and should
1228 	 * free this sock, as sk_free() call could not do it.
1229 	 */
1230 	if (res == 0)
1231 		__sk_free(sk);
1232 }
1233 EXPORT_SYMBOL(sock_wfree);
1234 
1235 /*
1236  * Read buffer destructor automatically called from kfree_skb.
1237  */
1238 void sock_rfree(struct sk_buff *skb)
1239 {
1240 	struct sock *sk = skb->sk;
1241 
1242 	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1243 	sk_mem_uncharge(skb->sk, skb->truesize);
1244 }
1245 EXPORT_SYMBOL(sock_rfree);
1246 
1247 
1248 int sock_i_uid(struct sock *sk)
1249 {
1250 	int uid;
1251 
1252 	read_lock(&sk->sk_callback_lock);
1253 	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1254 	read_unlock(&sk->sk_callback_lock);
1255 	return uid;
1256 }
1257 EXPORT_SYMBOL(sock_i_uid);
1258 
1259 unsigned long sock_i_ino(struct sock *sk)
1260 {
1261 	unsigned long ino;
1262 
1263 	read_lock(&sk->sk_callback_lock);
1264 	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1265 	read_unlock(&sk->sk_callback_lock);
1266 	return ino;
1267 }
1268 EXPORT_SYMBOL(sock_i_ino);
1269 
1270 /*
1271  * Allocate a skb from the socket's send buffer.
1272  */
1273 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1274 			     gfp_t priority)
1275 {
1276 	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1277 		struct sk_buff *skb = alloc_skb(size, priority);
1278 		if (skb) {
1279 			skb_set_owner_w(skb, sk);
1280 			return skb;
1281 		}
1282 	}
1283 	return NULL;
1284 }
1285 EXPORT_SYMBOL(sock_wmalloc);
1286 
1287 /*
1288  * Allocate a skb from the socket's receive buffer.
1289  */
1290 struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1291 			     gfp_t priority)
1292 {
1293 	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1294 		struct sk_buff *skb = alloc_skb(size, priority);
1295 		if (skb) {
1296 			skb_set_owner_r(skb, sk);
1297 			return skb;
1298 		}
1299 	}
1300 	return NULL;
1301 }
1302 
1303 /*
1304  * Allocate a memory block from the socket's option memory buffer.
1305  */
1306 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1307 {
1308 	if ((unsigned)size <= sysctl_optmem_max &&
1309 	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1310 		void *mem;
1311 		/* First do the add, to avoid the race if kmalloc
1312 		 * might sleep.
1313 		 */
1314 		atomic_add(size, &sk->sk_omem_alloc);
1315 		mem = kmalloc(size, priority);
1316 		if (mem)
1317 			return mem;
1318 		atomic_sub(size, &sk->sk_omem_alloc);
1319 	}
1320 	return NULL;
1321 }
1322 EXPORT_SYMBOL(sock_kmalloc);
1323 
1324 /*
1325  * Free an option memory block.
1326  */
1327 void sock_kfree_s(struct sock *sk, void *mem, int size)
1328 {
1329 	kfree(mem);
1330 	atomic_sub(size, &sk->sk_omem_alloc);
1331 }
1332 EXPORT_SYMBOL(sock_kfree_s);
1333 
1334 /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1335    I think, these locks should be removed for datagram sockets.
1336  */
1337 static long sock_wait_for_wmem(struct sock *sk, long timeo)
1338 {
1339 	DEFINE_WAIT(wait);
1340 
1341 	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1342 	for (;;) {
1343 		if (!timeo)
1344 			break;
1345 		if (signal_pending(current))
1346 			break;
1347 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1348 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1349 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1350 			break;
1351 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1352 			break;
1353 		if (sk->sk_err)
1354 			break;
1355 		timeo = schedule_timeout(timeo);
1356 	}
1357 	finish_wait(sk->sk_sleep, &wait);
1358 	return timeo;
1359 }
1360 
1361 
1362 /*
1363  *	Generic send/receive buffer handlers
1364  */
1365 
1366 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1367 				     unsigned long data_len, int noblock,
1368 				     int *errcode)
1369 {
1370 	struct sk_buff *skb;
1371 	gfp_t gfp_mask;
1372 	long timeo;
1373 	int err;
1374 
1375 	gfp_mask = sk->sk_allocation;
1376 	if (gfp_mask & __GFP_WAIT)
1377 		gfp_mask |= __GFP_REPEAT;
1378 
1379 	timeo = sock_sndtimeo(sk, noblock);
1380 	while (1) {
1381 		err = sock_error(sk);
1382 		if (err != 0)
1383 			goto failure;
1384 
1385 		err = -EPIPE;
1386 		if (sk->sk_shutdown & SEND_SHUTDOWN)
1387 			goto failure;
1388 
1389 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1390 			skb = alloc_skb(header_len, gfp_mask);
1391 			if (skb) {
1392 				int npages;
1393 				int i;
1394 
1395 				/* No pages, we're done... */
1396 				if (!data_len)
1397 					break;
1398 
1399 				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1400 				skb->truesize += data_len;
1401 				skb_shinfo(skb)->nr_frags = npages;
1402 				for (i = 0; i < npages; i++) {
1403 					struct page *page;
1404 					skb_frag_t *frag;
1405 
1406 					page = alloc_pages(sk->sk_allocation, 0);
1407 					if (!page) {
1408 						err = -ENOBUFS;
1409 						skb_shinfo(skb)->nr_frags = i;
1410 						kfree_skb(skb);
1411 						goto failure;
1412 					}
1413 
1414 					frag = &skb_shinfo(skb)->frags[i];
1415 					frag->page = page;
1416 					frag->page_offset = 0;
1417 					frag->size = (data_len >= PAGE_SIZE ?
1418 						      PAGE_SIZE :
1419 						      data_len);
1420 					data_len -= PAGE_SIZE;
1421 				}
1422 
1423 				/* Full success... */
1424 				break;
1425 			}
1426 			err = -ENOBUFS;
1427 			goto failure;
1428 		}
1429 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1430 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1431 		err = -EAGAIN;
1432 		if (!timeo)
1433 			goto failure;
1434 		if (signal_pending(current))
1435 			goto interrupted;
1436 		timeo = sock_wait_for_wmem(sk, timeo);
1437 	}
1438 
1439 	skb_set_owner_w(skb, sk);
1440 	return skb;
1441 
1442 interrupted:
1443 	err = sock_intr_errno(timeo);
1444 failure:
1445 	*errcode = err;
1446 	return NULL;
1447 }
1448 EXPORT_SYMBOL(sock_alloc_send_pskb);
1449 
1450 struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1451 				    int noblock, int *errcode)
1452 {
1453 	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1454 }
1455 EXPORT_SYMBOL(sock_alloc_send_skb);
1456 
1457 static void __lock_sock(struct sock *sk)
1458 {
1459 	DEFINE_WAIT(wait);
1460 
1461 	for (;;) {
1462 		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1463 					TASK_UNINTERRUPTIBLE);
1464 		spin_unlock_bh(&sk->sk_lock.slock);
1465 		schedule();
1466 		spin_lock_bh(&sk->sk_lock.slock);
1467 		if (!sock_owned_by_user(sk))
1468 			break;
1469 	}
1470 	finish_wait(&sk->sk_lock.wq, &wait);
1471 }
1472 
1473 static void __release_sock(struct sock *sk)
1474 {
1475 	struct sk_buff *skb = sk->sk_backlog.head;
1476 
1477 	do {
1478 		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1479 		bh_unlock_sock(sk);
1480 
1481 		do {
1482 			struct sk_buff *next = skb->next;
1483 
1484 			skb->next = NULL;
1485 			sk_backlog_rcv(sk, skb);
1486 
1487 			/*
1488 			 * We are in process context here with softirqs
1489 			 * disabled, use cond_resched_softirq() to preempt.
1490 			 * This is safe to do because we've taken the backlog
1491 			 * queue private:
1492 			 */
1493 			cond_resched_softirq();
1494 
1495 			skb = next;
1496 		} while (skb != NULL);
1497 
1498 		bh_lock_sock(sk);
1499 	} while ((skb = sk->sk_backlog.head) != NULL);
1500 }
1501 
1502 /**
1503  * sk_wait_data - wait for data to arrive at sk_receive_queue
1504  * @sk:    sock to wait on
1505  * @timeo: for how long
1506  *
1507  * Now socket state including sk->sk_err is changed only under lock,
1508  * hence we may omit checks after joining wait queue.
1509  * We check receive queue before schedule() only as optimization;
1510  * it is very likely that release_sock() added new data.
1511  */
1512 int sk_wait_data(struct sock *sk, long *timeo)
1513 {
1514 	int rc;
1515 	DEFINE_WAIT(wait);
1516 
1517 	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1518 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1519 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1520 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1521 	finish_wait(sk->sk_sleep, &wait);
1522 	return rc;
1523 }
1524 EXPORT_SYMBOL(sk_wait_data);
1525 
1526 /**
1527  *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1528  *	@sk: socket
1529  *	@size: memory size to allocate
1530  *	@kind: allocation type
1531  *
1532  *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1533  *	rmem allocation. This function assumes that protocols which have
1534  *	memory_pressure use sk_wmem_queued as write buffer accounting.
1535  */
1536 int __sk_mem_schedule(struct sock *sk, int size, int kind)
1537 {
1538 	struct proto *prot = sk->sk_prot;
1539 	int amt = sk_mem_pages(size);
1540 	int allocated;
1541 
1542 	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1543 	allocated = atomic_add_return(amt, prot->memory_allocated);
1544 
1545 	/* Under limit. */
1546 	if (allocated <= prot->sysctl_mem[0]) {
1547 		if (prot->memory_pressure && *prot->memory_pressure)
1548 			*prot->memory_pressure = 0;
1549 		return 1;
1550 	}
1551 
1552 	/* Under pressure. */
1553 	if (allocated > prot->sysctl_mem[1])
1554 		if (prot->enter_memory_pressure)
1555 			prot->enter_memory_pressure(sk);
1556 
1557 	/* Over hard limit. */
1558 	if (allocated > prot->sysctl_mem[2])
1559 		goto suppress_allocation;
1560 
1561 	/* guarantee minimum buffer size under pressure */
1562 	if (kind == SK_MEM_RECV) {
1563 		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1564 			return 1;
1565 	} else { /* SK_MEM_SEND */
1566 		if (sk->sk_type == SOCK_STREAM) {
1567 			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1568 				return 1;
1569 		} else if (atomic_read(&sk->sk_wmem_alloc) <
1570 			   prot->sysctl_wmem[0])
1571 				return 1;
1572 	}
1573 
1574 	if (prot->memory_pressure) {
1575 		int alloc;
1576 
1577 		if (!*prot->memory_pressure)
1578 			return 1;
1579 		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1580 		if (prot->sysctl_mem[2] > alloc *
1581 		    sk_mem_pages(sk->sk_wmem_queued +
1582 				 atomic_read(&sk->sk_rmem_alloc) +
1583 				 sk->sk_forward_alloc))
1584 			return 1;
1585 	}
1586 
1587 suppress_allocation:
1588 
1589 	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1590 		sk_stream_moderate_sndbuf(sk);
1591 
1592 		/* Fail only if socket is _under_ its sndbuf.
1593 		 * In this case we cannot block, so that we have to fail.
1594 		 */
1595 		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1596 			return 1;
1597 	}
1598 
1599 	/* Alas. Undo changes. */
1600 	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1601 	atomic_sub(amt, prot->memory_allocated);
1602 	return 0;
1603 }
1604 EXPORT_SYMBOL(__sk_mem_schedule);
1605 
1606 /**
1607  *	__sk_reclaim - reclaim memory_allocated
1608  *	@sk: socket
1609  */
1610 void __sk_mem_reclaim(struct sock *sk)
1611 {
1612 	struct proto *prot = sk->sk_prot;
1613 
1614 	atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1615 		   prot->memory_allocated);
1616 	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1617 
1618 	if (prot->memory_pressure && *prot->memory_pressure &&
1619 	    (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1620 		*prot->memory_pressure = 0;
1621 }
1622 EXPORT_SYMBOL(__sk_mem_reclaim);
1623 
1624 
1625 /*
1626  * Set of default routines for initialising struct proto_ops when
1627  * the protocol does not support a particular function. In certain
1628  * cases where it makes no sense for a protocol to have a "do nothing"
1629  * function, some default processing is provided.
1630  */
1631 
1632 int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1633 {
1634 	return -EOPNOTSUPP;
1635 }
1636 EXPORT_SYMBOL(sock_no_bind);
1637 
1638 int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1639 		    int len, int flags)
1640 {
1641 	return -EOPNOTSUPP;
1642 }
1643 EXPORT_SYMBOL(sock_no_connect);
1644 
1645 int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1646 {
1647 	return -EOPNOTSUPP;
1648 }
1649 EXPORT_SYMBOL(sock_no_socketpair);
1650 
1651 int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1652 {
1653 	return -EOPNOTSUPP;
1654 }
1655 EXPORT_SYMBOL(sock_no_accept);
1656 
1657 int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1658 		    int *len, int peer)
1659 {
1660 	return -EOPNOTSUPP;
1661 }
1662 EXPORT_SYMBOL(sock_no_getname);
1663 
1664 unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1665 {
1666 	return 0;
1667 }
1668 EXPORT_SYMBOL(sock_no_poll);
1669 
1670 int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1671 {
1672 	return -EOPNOTSUPP;
1673 }
1674 EXPORT_SYMBOL(sock_no_ioctl);
1675 
1676 int sock_no_listen(struct socket *sock, int backlog)
1677 {
1678 	return -EOPNOTSUPP;
1679 }
1680 EXPORT_SYMBOL(sock_no_listen);
1681 
1682 int sock_no_shutdown(struct socket *sock, int how)
1683 {
1684 	return -EOPNOTSUPP;
1685 }
1686 EXPORT_SYMBOL(sock_no_shutdown);
1687 
1688 int sock_no_setsockopt(struct socket *sock, int level, int optname,
1689 		    char __user *optval, int optlen)
1690 {
1691 	return -EOPNOTSUPP;
1692 }
1693 EXPORT_SYMBOL(sock_no_setsockopt);
1694 
1695 int sock_no_getsockopt(struct socket *sock, int level, int optname,
1696 		    char __user *optval, int __user *optlen)
1697 {
1698 	return -EOPNOTSUPP;
1699 }
1700 EXPORT_SYMBOL(sock_no_getsockopt);
1701 
1702 int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1703 		    size_t len)
1704 {
1705 	return -EOPNOTSUPP;
1706 }
1707 EXPORT_SYMBOL(sock_no_sendmsg);
1708 
1709 int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1710 		    size_t len, int flags)
1711 {
1712 	return -EOPNOTSUPP;
1713 }
1714 EXPORT_SYMBOL(sock_no_recvmsg);
1715 
1716 int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1717 {
1718 	/* Mirror missing mmap method error code */
1719 	return -ENODEV;
1720 }
1721 EXPORT_SYMBOL(sock_no_mmap);
1722 
1723 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1724 {
1725 	ssize_t res;
1726 	struct msghdr msg = {.msg_flags = flags};
1727 	struct kvec iov;
1728 	char *kaddr = kmap(page);
1729 	iov.iov_base = kaddr + offset;
1730 	iov.iov_len = size;
1731 	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1732 	kunmap(page);
1733 	return res;
1734 }
1735 EXPORT_SYMBOL(sock_no_sendpage);
1736 
1737 /*
1738  *	Default Socket Callbacks
1739  */
1740 
1741 static void sock_def_wakeup(struct sock *sk)
1742 {
1743 	read_lock(&sk->sk_callback_lock);
1744 	if (sk_has_sleeper(sk))
1745 		wake_up_interruptible_all(sk->sk_sleep);
1746 	read_unlock(&sk->sk_callback_lock);
1747 }
1748 
1749 static void sock_def_error_report(struct sock *sk)
1750 {
1751 	read_lock(&sk->sk_callback_lock);
1752 	if (sk_has_sleeper(sk))
1753 		wake_up_interruptible_poll(sk->sk_sleep, POLLERR);
1754 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1755 	read_unlock(&sk->sk_callback_lock);
1756 }
1757 
1758 static void sock_def_readable(struct sock *sk, int len)
1759 {
1760 	read_lock(&sk->sk_callback_lock);
1761 	if (sk_has_sleeper(sk))
1762 		wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN |
1763 						POLLRDNORM | POLLRDBAND);
1764 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1765 	read_unlock(&sk->sk_callback_lock);
1766 }
1767 
1768 static void sock_def_write_space(struct sock *sk)
1769 {
1770 	read_lock(&sk->sk_callback_lock);
1771 
1772 	/* Do not wake up a writer until he can make "significant"
1773 	 * progress.  --DaveM
1774 	 */
1775 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1776 		if (sk_has_sleeper(sk))
1777 			wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
1778 						POLLWRNORM | POLLWRBAND);
1779 
1780 		/* Should agree with poll, otherwise some programs break */
1781 		if (sock_writeable(sk))
1782 			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1783 	}
1784 
1785 	read_unlock(&sk->sk_callback_lock);
1786 }
1787 
1788 static void sock_def_destruct(struct sock *sk)
1789 {
1790 	kfree(sk->sk_protinfo);
1791 }
1792 
1793 void sk_send_sigurg(struct sock *sk)
1794 {
1795 	if (sk->sk_socket && sk->sk_socket->file)
1796 		if (send_sigurg(&sk->sk_socket->file->f_owner))
1797 			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1798 }
1799 EXPORT_SYMBOL(sk_send_sigurg);
1800 
1801 void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1802 		    unsigned long expires)
1803 {
1804 	if (!mod_timer(timer, expires))
1805 		sock_hold(sk);
1806 }
1807 EXPORT_SYMBOL(sk_reset_timer);
1808 
1809 void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1810 {
1811 	if (timer_pending(timer) && del_timer(timer))
1812 		__sock_put(sk);
1813 }
1814 EXPORT_SYMBOL(sk_stop_timer);
1815 
1816 void sock_init_data(struct socket *sock, struct sock *sk)
1817 {
1818 	skb_queue_head_init(&sk->sk_receive_queue);
1819 	skb_queue_head_init(&sk->sk_write_queue);
1820 	skb_queue_head_init(&sk->sk_error_queue);
1821 #ifdef CONFIG_NET_DMA
1822 	skb_queue_head_init(&sk->sk_async_wait_queue);
1823 #endif
1824 
1825 	sk->sk_send_head	=	NULL;
1826 
1827 	init_timer(&sk->sk_timer);
1828 
1829 	sk->sk_allocation	=	GFP_KERNEL;
1830 	sk->sk_rcvbuf		=	sysctl_rmem_default;
1831 	sk->sk_sndbuf		=	sysctl_wmem_default;
1832 	sk->sk_state		=	TCP_CLOSE;
1833 	sk_set_socket(sk, sock);
1834 
1835 	sock_set_flag(sk, SOCK_ZAPPED);
1836 
1837 	if (sock) {
1838 		sk->sk_type	=	sock->type;
1839 		sk->sk_sleep	=	&sock->wait;
1840 		sock->sk	=	sk;
1841 	} else
1842 		sk->sk_sleep	=	NULL;
1843 
1844 	rwlock_init(&sk->sk_dst_lock);
1845 	rwlock_init(&sk->sk_callback_lock);
1846 	lockdep_set_class_and_name(&sk->sk_callback_lock,
1847 			af_callback_keys + sk->sk_family,
1848 			af_family_clock_key_strings[sk->sk_family]);
1849 
1850 	sk->sk_state_change	=	sock_def_wakeup;
1851 	sk->sk_data_ready	=	sock_def_readable;
1852 	sk->sk_write_space	=	sock_def_write_space;
1853 	sk->sk_error_report	=	sock_def_error_report;
1854 	sk->sk_destruct		=	sock_def_destruct;
1855 
1856 	sk->sk_sndmsg_page	=	NULL;
1857 	sk->sk_sndmsg_off	=	0;
1858 
1859 	sk->sk_peercred.pid 	=	0;
1860 	sk->sk_peercred.uid	=	-1;
1861 	sk->sk_peercred.gid	=	-1;
1862 	sk->sk_write_pending	=	0;
1863 	sk->sk_rcvlowat		=	1;
1864 	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1865 	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1866 
1867 	sk->sk_stamp = ktime_set(-1L, 0);
1868 
1869 	/*
1870 	 * Before updating sk_refcnt, we must commit prior changes to memory
1871 	 * (Documentation/RCU/rculist_nulls.txt for details)
1872 	 */
1873 	smp_wmb();
1874 	atomic_set(&sk->sk_refcnt, 1);
1875 	atomic_set(&sk->sk_wmem_alloc, 1);
1876 	atomic_set(&sk->sk_drops, 0);
1877 }
1878 EXPORT_SYMBOL(sock_init_data);
1879 
1880 void lock_sock_nested(struct sock *sk, int subclass)
1881 {
1882 	might_sleep();
1883 	spin_lock_bh(&sk->sk_lock.slock);
1884 	if (sk->sk_lock.owned)
1885 		__lock_sock(sk);
1886 	sk->sk_lock.owned = 1;
1887 	spin_unlock(&sk->sk_lock.slock);
1888 	/*
1889 	 * The sk_lock has mutex_lock() semantics here:
1890 	 */
1891 	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
1892 	local_bh_enable();
1893 }
1894 EXPORT_SYMBOL(lock_sock_nested);
1895 
1896 void release_sock(struct sock *sk)
1897 {
1898 	/*
1899 	 * The sk_lock has mutex_unlock() semantics:
1900 	 */
1901 	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1902 
1903 	spin_lock_bh(&sk->sk_lock.slock);
1904 	if (sk->sk_backlog.tail)
1905 		__release_sock(sk);
1906 	sk->sk_lock.owned = 0;
1907 	if (waitqueue_active(&sk->sk_lock.wq))
1908 		wake_up(&sk->sk_lock.wq);
1909 	spin_unlock_bh(&sk->sk_lock.slock);
1910 }
1911 EXPORT_SYMBOL(release_sock);
1912 
1913 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1914 {
1915 	struct timeval tv;
1916 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1917 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1918 	tv = ktime_to_timeval(sk->sk_stamp);
1919 	if (tv.tv_sec == -1)
1920 		return -ENOENT;
1921 	if (tv.tv_sec == 0) {
1922 		sk->sk_stamp = ktime_get_real();
1923 		tv = ktime_to_timeval(sk->sk_stamp);
1924 	}
1925 	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
1926 }
1927 EXPORT_SYMBOL(sock_get_timestamp);
1928 
1929 int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
1930 {
1931 	struct timespec ts;
1932 	if (!sock_flag(sk, SOCK_TIMESTAMP))
1933 		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1934 	ts = ktime_to_timespec(sk->sk_stamp);
1935 	if (ts.tv_sec == -1)
1936 		return -ENOENT;
1937 	if (ts.tv_sec == 0) {
1938 		sk->sk_stamp = ktime_get_real();
1939 		ts = ktime_to_timespec(sk->sk_stamp);
1940 	}
1941 	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
1942 }
1943 EXPORT_SYMBOL(sock_get_timestampns);
1944 
1945 void sock_enable_timestamp(struct sock *sk, int flag)
1946 {
1947 	if (!sock_flag(sk, flag)) {
1948 		sock_set_flag(sk, flag);
1949 		/*
1950 		 * we just set one of the two flags which require net
1951 		 * time stamping, but time stamping might have been on
1952 		 * already because of the other one
1953 		 */
1954 		if (!sock_flag(sk,
1955 				flag == SOCK_TIMESTAMP ?
1956 				SOCK_TIMESTAMPING_RX_SOFTWARE :
1957 				SOCK_TIMESTAMP))
1958 			net_enable_timestamp();
1959 	}
1960 }
1961 
1962 /*
1963  *	Get a socket option on an socket.
1964  *
1965  *	FIX: POSIX 1003.1g is very ambiguous here. It states that
1966  *	asynchronous errors should be reported by getsockopt. We assume
1967  *	this means if you specify SO_ERROR (otherwise whats the point of it).
1968  */
1969 int sock_common_getsockopt(struct socket *sock, int level, int optname,
1970 			   char __user *optval, int __user *optlen)
1971 {
1972 	struct sock *sk = sock->sk;
1973 
1974 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
1975 }
1976 EXPORT_SYMBOL(sock_common_getsockopt);
1977 
1978 #ifdef CONFIG_COMPAT
1979 int compat_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 	if (sk->sk_prot->compat_getsockopt != NULL)
1985 		return sk->sk_prot->compat_getsockopt(sk, level, optname,
1986 						      optval, optlen);
1987 	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
1988 }
1989 EXPORT_SYMBOL(compat_sock_common_getsockopt);
1990 #endif
1991 
1992 int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1993 			struct msghdr *msg, size_t size, int flags)
1994 {
1995 	struct sock *sk = sock->sk;
1996 	int addr_len = 0;
1997 	int err;
1998 
1999 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2000 				   flags & ~MSG_DONTWAIT, &addr_len);
2001 	if (err >= 0)
2002 		msg->msg_namelen = addr_len;
2003 	return err;
2004 }
2005 EXPORT_SYMBOL(sock_common_recvmsg);
2006 
2007 /*
2008  *	Set socket options on an inet socket.
2009  */
2010 int sock_common_setsockopt(struct socket *sock, int level, int optname,
2011 			   char __user *optval, int optlen)
2012 {
2013 	struct sock *sk = sock->sk;
2014 
2015 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2016 }
2017 EXPORT_SYMBOL(sock_common_setsockopt);
2018 
2019 #ifdef CONFIG_COMPAT
2020 int compat_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 	if (sk->sk_prot->compat_setsockopt != NULL)
2026 		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2027 						      optval, optlen);
2028 	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2029 }
2030 EXPORT_SYMBOL(compat_sock_common_setsockopt);
2031 #endif
2032 
2033 void sk_common_release(struct sock *sk)
2034 {
2035 	if (sk->sk_prot->destroy)
2036 		sk->sk_prot->destroy(sk);
2037 
2038 	/*
2039 	 * Observation: when sock_common_release is called, processes have
2040 	 * no access to socket. But net still has.
2041 	 * Step one, detach it from networking:
2042 	 *
2043 	 * A. Remove from hash tables.
2044 	 */
2045 
2046 	sk->sk_prot->unhash(sk);
2047 
2048 	/*
2049 	 * In this point socket cannot receive new packets, but it is possible
2050 	 * that some packets are in flight because some CPU runs receiver and
2051 	 * did hash table lookup before we unhashed socket. They will achieve
2052 	 * receive queue and will be purged by socket destructor.
2053 	 *
2054 	 * Also we still have packets pending on receive queue and probably,
2055 	 * our own packets waiting in device queues. sock_destroy will drain
2056 	 * receive queue, but transmitted packets will delay socket destruction
2057 	 * until the last reference will be released.
2058 	 */
2059 
2060 	sock_orphan(sk);
2061 
2062 	xfrm_sk_free_policy(sk);
2063 
2064 	sk_refcnt_debug_release(sk);
2065 	sock_put(sk);
2066 }
2067 EXPORT_SYMBOL(sk_common_release);
2068 
2069 static DEFINE_RWLOCK(proto_list_lock);
2070 static LIST_HEAD(proto_list);
2071 
2072 #ifdef CONFIG_PROC_FS
2073 #define PROTO_INUSE_NR	64	/* should be enough for the first time */
2074 struct prot_inuse {
2075 	int val[PROTO_INUSE_NR];
2076 };
2077 
2078 static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2079 
2080 #ifdef CONFIG_NET_NS
2081 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2082 {
2083 	int cpu = smp_processor_id();
2084 	per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
2085 }
2086 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2087 
2088 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2089 {
2090 	int cpu, idx = prot->inuse_idx;
2091 	int res = 0;
2092 
2093 	for_each_possible_cpu(cpu)
2094 		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2095 
2096 	return res >= 0 ? res : 0;
2097 }
2098 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2099 
2100 static int sock_inuse_init_net(struct net *net)
2101 {
2102 	net->core.inuse = alloc_percpu(struct prot_inuse);
2103 	return net->core.inuse ? 0 : -ENOMEM;
2104 }
2105 
2106 static void sock_inuse_exit_net(struct net *net)
2107 {
2108 	free_percpu(net->core.inuse);
2109 }
2110 
2111 static struct pernet_operations net_inuse_ops = {
2112 	.init = sock_inuse_init_net,
2113 	.exit = sock_inuse_exit_net,
2114 };
2115 
2116 static __init int net_inuse_init(void)
2117 {
2118 	if (register_pernet_subsys(&net_inuse_ops))
2119 		panic("Cannot initialize net inuse counters");
2120 
2121 	return 0;
2122 }
2123 
2124 core_initcall(net_inuse_init);
2125 #else
2126 static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2127 
2128 void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2129 {
2130 	__get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
2131 }
2132 EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2133 
2134 int sock_prot_inuse_get(struct net *net, struct proto *prot)
2135 {
2136 	int cpu, idx = prot->inuse_idx;
2137 	int res = 0;
2138 
2139 	for_each_possible_cpu(cpu)
2140 		res += per_cpu(prot_inuse, cpu).val[idx];
2141 
2142 	return res >= 0 ? res : 0;
2143 }
2144 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2145 #endif
2146 
2147 static void assign_proto_idx(struct proto *prot)
2148 {
2149 	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2150 
2151 	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2152 		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2153 		return;
2154 	}
2155 
2156 	set_bit(prot->inuse_idx, proto_inuse_idx);
2157 }
2158 
2159 static void release_proto_idx(struct proto *prot)
2160 {
2161 	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2162 		clear_bit(prot->inuse_idx, proto_inuse_idx);
2163 }
2164 #else
2165 static inline void assign_proto_idx(struct proto *prot)
2166 {
2167 }
2168 
2169 static inline void release_proto_idx(struct proto *prot)
2170 {
2171 }
2172 #endif
2173 
2174 int proto_register(struct proto *prot, int alloc_slab)
2175 {
2176 	if (alloc_slab) {
2177 		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2178 					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2179 					NULL);
2180 
2181 		if (prot->slab == NULL) {
2182 			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2183 			       prot->name);
2184 			goto out;
2185 		}
2186 
2187 		if (prot->rsk_prot != NULL) {
2188 			static const char mask[] = "request_sock_%s";
2189 
2190 			prot->rsk_prot->slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2191 			if (prot->rsk_prot->slab_name == NULL)
2192 				goto out_free_sock_slab;
2193 
2194 			sprintf(prot->rsk_prot->slab_name, mask, prot->name);
2195 			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2196 								 prot->rsk_prot->obj_size, 0,
2197 								 SLAB_HWCACHE_ALIGN, NULL);
2198 
2199 			if (prot->rsk_prot->slab == NULL) {
2200 				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2201 				       prot->name);
2202 				goto out_free_request_sock_slab_name;
2203 			}
2204 		}
2205 
2206 		if (prot->twsk_prot != NULL) {
2207 			static const char mask[] = "tw_sock_%s";
2208 
2209 			prot->twsk_prot->twsk_slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2210 
2211 			if (prot->twsk_prot->twsk_slab_name == NULL)
2212 				goto out_free_request_sock_slab;
2213 
2214 			sprintf(prot->twsk_prot->twsk_slab_name, mask, prot->name);
2215 			prot->twsk_prot->twsk_slab =
2216 				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2217 						  prot->twsk_prot->twsk_obj_size,
2218 						  0,
2219 						  SLAB_HWCACHE_ALIGN |
2220 							prot->slab_flags,
2221 						  NULL);
2222 			if (prot->twsk_prot->twsk_slab == NULL)
2223 				goto out_free_timewait_sock_slab_name;
2224 		}
2225 	}
2226 
2227 	write_lock(&proto_list_lock);
2228 	list_add(&prot->node, &proto_list);
2229 	assign_proto_idx(prot);
2230 	write_unlock(&proto_list_lock);
2231 	return 0;
2232 
2233 out_free_timewait_sock_slab_name:
2234 	kfree(prot->twsk_prot->twsk_slab_name);
2235 out_free_request_sock_slab:
2236 	if (prot->rsk_prot && prot->rsk_prot->slab) {
2237 		kmem_cache_destroy(prot->rsk_prot->slab);
2238 		prot->rsk_prot->slab = NULL;
2239 	}
2240 out_free_request_sock_slab_name:
2241 	kfree(prot->rsk_prot->slab_name);
2242 out_free_sock_slab:
2243 	kmem_cache_destroy(prot->slab);
2244 	prot->slab = NULL;
2245 out:
2246 	return -ENOBUFS;
2247 }
2248 EXPORT_SYMBOL(proto_register);
2249 
2250 void proto_unregister(struct proto *prot)
2251 {
2252 	write_lock(&proto_list_lock);
2253 	release_proto_idx(prot);
2254 	list_del(&prot->node);
2255 	write_unlock(&proto_list_lock);
2256 
2257 	if (prot->slab != NULL) {
2258 		kmem_cache_destroy(prot->slab);
2259 		prot->slab = NULL;
2260 	}
2261 
2262 	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2263 		kmem_cache_destroy(prot->rsk_prot->slab);
2264 		kfree(prot->rsk_prot->slab_name);
2265 		prot->rsk_prot->slab = NULL;
2266 	}
2267 
2268 	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2269 		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2270 		kfree(prot->twsk_prot->twsk_slab_name);
2271 		prot->twsk_prot->twsk_slab = NULL;
2272 	}
2273 }
2274 EXPORT_SYMBOL(proto_unregister);
2275 
2276 #ifdef CONFIG_PROC_FS
2277 static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2278 	__acquires(proto_list_lock)
2279 {
2280 	read_lock(&proto_list_lock);
2281 	return seq_list_start_head(&proto_list, *pos);
2282 }
2283 
2284 static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2285 {
2286 	return seq_list_next(v, &proto_list, pos);
2287 }
2288 
2289 static void proto_seq_stop(struct seq_file *seq, void *v)
2290 	__releases(proto_list_lock)
2291 {
2292 	read_unlock(&proto_list_lock);
2293 }
2294 
2295 static char proto_method_implemented(const void *method)
2296 {
2297 	return method == NULL ? 'n' : 'y';
2298 }
2299 
2300 static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2301 {
2302 	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
2303 			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2304 		   proto->name,
2305 		   proto->obj_size,
2306 		   sock_prot_inuse_get(seq_file_net(seq), proto),
2307 		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
2308 		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2309 		   proto->max_header,
2310 		   proto->slab == NULL ? "no" : "yes",
2311 		   module_name(proto->owner),
2312 		   proto_method_implemented(proto->close),
2313 		   proto_method_implemented(proto->connect),
2314 		   proto_method_implemented(proto->disconnect),
2315 		   proto_method_implemented(proto->accept),
2316 		   proto_method_implemented(proto->ioctl),
2317 		   proto_method_implemented(proto->init),
2318 		   proto_method_implemented(proto->destroy),
2319 		   proto_method_implemented(proto->shutdown),
2320 		   proto_method_implemented(proto->setsockopt),
2321 		   proto_method_implemented(proto->getsockopt),
2322 		   proto_method_implemented(proto->sendmsg),
2323 		   proto_method_implemented(proto->recvmsg),
2324 		   proto_method_implemented(proto->sendpage),
2325 		   proto_method_implemented(proto->bind),
2326 		   proto_method_implemented(proto->backlog_rcv),
2327 		   proto_method_implemented(proto->hash),
2328 		   proto_method_implemented(proto->unhash),
2329 		   proto_method_implemented(proto->get_port),
2330 		   proto_method_implemented(proto->enter_memory_pressure));
2331 }
2332 
2333 static int proto_seq_show(struct seq_file *seq, void *v)
2334 {
2335 	if (v == &proto_list)
2336 		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2337 			   "protocol",
2338 			   "size",
2339 			   "sockets",
2340 			   "memory",
2341 			   "press",
2342 			   "maxhdr",
2343 			   "slab",
2344 			   "module",
2345 			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2346 	else
2347 		proto_seq_printf(seq, list_entry(v, struct proto, node));
2348 	return 0;
2349 }
2350 
2351 static const struct seq_operations proto_seq_ops = {
2352 	.start  = proto_seq_start,
2353 	.next   = proto_seq_next,
2354 	.stop   = proto_seq_stop,
2355 	.show   = proto_seq_show,
2356 };
2357 
2358 static int proto_seq_open(struct inode *inode, struct file *file)
2359 {
2360 	return seq_open_net(inode, file, &proto_seq_ops,
2361 			    sizeof(struct seq_net_private));
2362 }
2363 
2364 static const struct file_operations proto_seq_fops = {
2365 	.owner		= THIS_MODULE,
2366 	.open		= proto_seq_open,
2367 	.read		= seq_read,
2368 	.llseek		= seq_lseek,
2369 	.release	= seq_release_net,
2370 };
2371 
2372 static __net_init int proto_init_net(struct net *net)
2373 {
2374 	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2375 		return -ENOMEM;
2376 
2377 	return 0;
2378 }
2379 
2380 static __net_exit void proto_exit_net(struct net *net)
2381 {
2382 	proc_net_remove(net, "protocols");
2383 }
2384 
2385 
2386 static __net_initdata struct pernet_operations proto_net_ops = {
2387 	.init = proto_init_net,
2388 	.exit = proto_exit_net,
2389 };
2390 
2391 static int __init proto_init(void)
2392 {
2393 	return register_pernet_subsys(&proto_net_ops);
2394 }
2395 
2396 subsys_initcall(proto_init);
2397 
2398 #endif /* PROC_FS */
2399