sock.c revision a898def29e4119bc01ebe7ca97423181f4c0ea2d
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 */
137static struct lock_class_key af_family_keys[AF_MAX];
138static 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 */
145static 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};
161static 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};
177static 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 */
198static 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 */
217int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
218EXPORT_SYMBOL(sysctl_optmem_max);
219
220static 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
251static 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
263static 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
275int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
276{
277	int err;
278	int skb_len;
279	unsigned long flags;
280	struct sk_buff_head *list = &sk->sk_receive_queue;
281
282	/* Cast sk->rcvbuf to unsigned... It's pointless, but reduces
283	   number of warnings when compiling with -W --ANK
284	 */
285	if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
286	    (unsigned)sk->sk_rcvbuf) {
287		atomic_inc(&sk->sk_drops);
288		return -ENOMEM;
289	}
290
291	err = sk_filter(sk, skb);
292	if (err)
293		return err;
294
295	if (!sk_rmem_schedule(sk, skb->truesize)) {
296		atomic_inc(&sk->sk_drops);
297		return -ENOBUFS;
298	}
299
300	skb->dev = NULL;
301	skb_set_owner_r(skb, sk);
302
303	/* Cache the SKB length before we tack it onto the receive
304	 * queue.  Once it is added it no longer belongs to us and
305	 * may be freed by other threads of control pulling packets
306	 * from the queue.
307	 */
308	skb_len = skb->len;
309
310	spin_lock_irqsave(&list->lock, flags);
311	skb->dropcount = atomic_read(&sk->sk_drops);
312	__skb_queue_tail(list, skb);
313	spin_unlock_irqrestore(&list->lock, flags);
314
315	if (!sock_flag(sk, SOCK_DEAD))
316		sk->sk_data_ready(sk, skb_len);
317	return 0;
318}
319EXPORT_SYMBOL(sock_queue_rcv_skb);
320
321int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
322{
323	int rc = NET_RX_SUCCESS;
324
325	if (sk_filter(sk, skb))
326		goto discard_and_relse;
327
328	skb->dev = NULL;
329
330	if (nested)
331		bh_lock_sock_nested(sk);
332	else
333		bh_lock_sock(sk);
334	if (!sock_owned_by_user(sk)) {
335		/*
336		 * trylock + unlock semantics:
337		 */
338		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
339
340		rc = sk_backlog_rcv(sk, skb);
341
342		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
343	} else
344		sk_add_backlog(sk, skb);
345	bh_unlock_sock(sk);
346out:
347	sock_put(sk);
348	return rc;
349discard_and_relse:
350	kfree_skb(skb);
351	goto out;
352}
353EXPORT_SYMBOL(sk_receive_skb);
354
355void sk_reset_txq(struct sock *sk)
356{
357	sk_tx_queue_clear(sk);
358}
359EXPORT_SYMBOL(sk_reset_txq);
360
361struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
362{
363	struct dst_entry *dst = sk->sk_dst_cache;
364
365	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
366		sk_tx_queue_clear(sk);
367		sk->sk_dst_cache = NULL;
368		dst_release(dst);
369		return NULL;
370	}
371
372	return dst;
373}
374EXPORT_SYMBOL(__sk_dst_check);
375
376struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
377{
378	struct dst_entry *dst = sk_dst_get(sk);
379
380	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
381		sk_dst_reset(sk);
382		dst_release(dst);
383		return NULL;
384	}
385
386	return dst;
387}
388EXPORT_SYMBOL(sk_dst_check);
389
390static int sock_bindtodevice(struct sock *sk, char __user *optval, int optlen)
391{
392	int ret = -ENOPROTOOPT;
393#ifdef CONFIG_NETDEVICES
394	struct net *net = sock_net(sk);
395	char devname[IFNAMSIZ];
396	int index;
397
398	/* Sorry... */
399	ret = -EPERM;
400	if (!capable(CAP_NET_RAW))
401		goto out;
402
403	ret = -EINVAL;
404	if (optlen < 0)
405		goto out;
406
407	/* Bind this socket to a particular device like "eth0",
408	 * as specified in the passed interface name. If the
409	 * name is "" or the option length is zero the socket
410	 * is not bound.
411	 */
412	if (optlen > IFNAMSIZ - 1)
413		optlen = IFNAMSIZ - 1;
414	memset(devname, 0, sizeof(devname));
415
416	ret = -EFAULT;
417	if (copy_from_user(devname, optval, optlen))
418		goto out;
419
420	index = 0;
421	if (devname[0] != '\0') {
422		struct net_device *dev;
423
424		rcu_read_lock();
425		dev = dev_get_by_name_rcu(net, devname);
426		if (dev)
427			index = dev->ifindex;
428		rcu_read_unlock();
429		ret = -ENODEV;
430		if (!dev)
431			goto out;
432	}
433
434	lock_sock(sk);
435	sk->sk_bound_dev_if = index;
436	sk_dst_reset(sk);
437	release_sock(sk);
438
439	ret = 0;
440
441out:
442#endif
443
444	return ret;
445}
446
447static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
448{
449	if (valbool)
450		sock_set_flag(sk, bit);
451	else
452		sock_reset_flag(sk, bit);
453}
454
455/*
456 *	This is meant for all protocols to use and covers goings on
457 *	at the socket level. Everything here is generic.
458 */
459
460int sock_setsockopt(struct socket *sock, int level, int optname,
461		    char __user *optval, unsigned int optlen)
462{
463	struct sock *sk = sock->sk;
464	int val;
465	int valbool;
466	struct linger ling;
467	int ret = 0;
468
469	/*
470	 *	Options without arguments
471	 */
472
473	if (optname == SO_BINDTODEVICE)
474		return sock_bindtodevice(sk, optval, optlen);
475
476	if (optlen < sizeof(int))
477		return -EINVAL;
478
479	if (get_user(val, (int __user *)optval))
480		return -EFAULT;
481
482	valbool = val ? 1 : 0;
483
484	lock_sock(sk);
485
486	switch (optname) {
487	case SO_DEBUG:
488		if (val && !capable(CAP_NET_ADMIN))
489			ret = -EACCES;
490		else
491			sock_valbool_flag(sk, SOCK_DBG, valbool);
492		break;
493	case SO_REUSEADDR:
494		sk->sk_reuse = valbool;
495		break;
496	case SO_TYPE:
497	case SO_PROTOCOL:
498	case SO_DOMAIN:
499	case SO_ERROR:
500		ret = -ENOPROTOOPT;
501		break;
502	case SO_DONTROUTE:
503		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
504		break;
505	case SO_BROADCAST:
506		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
507		break;
508	case SO_SNDBUF:
509		/* Don't error on this BSD doesn't and if you think
510		   about it this is right. Otherwise apps have to
511		   play 'guess the biggest size' games. RCVBUF/SNDBUF
512		   are treated in BSD as hints */
513
514		if (val > sysctl_wmem_max)
515			val = sysctl_wmem_max;
516set_sndbuf:
517		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
518		if ((val * 2) < SOCK_MIN_SNDBUF)
519			sk->sk_sndbuf = SOCK_MIN_SNDBUF;
520		else
521			sk->sk_sndbuf = val * 2;
522
523		/*
524		 *	Wake up sending tasks if we
525		 *	upped the value.
526		 */
527		sk->sk_write_space(sk);
528		break;
529
530	case SO_SNDBUFFORCE:
531		if (!capable(CAP_NET_ADMIN)) {
532			ret = -EPERM;
533			break;
534		}
535		goto set_sndbuf;
536
537	case SO_RCVBUF:
538		/* Don't error on this BSD doesn't and if you think
539		   about it this is right. Otherwise apps have to
540		   play 'guess the biggest size' games. RCVBUF/SNDBUF
541		   are treated in BSD as hints */
542
543		if (val > sysctl_rmem_max)
544			val = sysctl_rmem_max;
545set_rcvbuf:
546		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
547		/*
548		 * We double it on the way in to account for
549		 * "struct sk_buff" etc. overhead.   Applications
550		 * assume that the SO_RCVBUF setting they make will
551		 * allow that much actual data to be received on that
552		 * socket.
553		 *
554		 * Applications are unaware that "struct sk_buff" and
555		 * other overheads allocate from the receive buffer
556		 * during socket buffer allocation.
557		 *
558		 * And after considering the possible alternatives,
559		 * returning the value we actually used in getsockopt
560		 * is the most desirable behavior.
561		 */
562		if ((val * 2) < SOCK_MIN_RCVBUF)
563			sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
564		else
565			sk->sk_rcvbuf = val * 2;
566		break;
567
568	case SO_RCVBUFFORCE:
569		if (!capable(CAP_NET_ADMIN)) {
570			ret = -EPERM;
571			break;
572		}
573		goto set_rcvbuf;
574
575	case SO_KEEPALIVE:
576#ifdef CONFIG_INET
577		if (sk->sk_protocol == IPPROTO_TCP)
578			tcp_set_keepalive(sk, valbool);
579#endif
580		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
581		break;
582
583	case SO_OOBINLINE:
584		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
585		break;
586
587	case SO_NO_CHECK:
588		sk->sk_no_check = valbool;
589		break;
590
591	case SO_PRIORITY:
592		if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
593			sk->sk_priority = val;
594		else
595			ret = -EPERM;
596		break;
597
598	case SO_LINGER:
599		if (optlen < sizeof(ling)) {
600			ret = -EINVAL;	/* 1003.1g */
601			break;
602		}
603		if (copy_from_user(&ling, optval, sizeof(ling))) {
604			ret = -EFAULT;
605			break;
606		}
607		if (!ling.l_onoff)
608			sock_reset_flag(sk, SOCK_LINGER);
609		else {
610#if (BITS_PER_LONG == 32)
611			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
612				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
613			else
614#endif
615				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
616			sock_set_flag(sk, SOCK_LINGER);
617		}
618		break;
619
620	case SO_BSDCOMPAT:
621		sock_warn_obsolete_bsdism("setsockopt");
622		break;
623
624	case SO_PASSCRED:
625		if (valbool)
626			set_bit(SOCK_PASSCRED, &sock->flags);
627		else
628			clear_bit(SOCK_PASSCRED, &sock->flags);
629		break;
630
631	case SO_TIMESTAMP:
632	case SO_TIMESTAMPNS:
633		if (valbool)  {
634			if (optname == SO_TIMESTAMP)
635				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
636			else
637				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
638			sock_set_flag(sk, SOCK_RCVTSTAMP);
639			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
640		} else {
641			sock_reset_flag(sk, SOCK_RCVTSTAMP);
642			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
643		}
644		break;
645
646	case SO_TIMESTAMPING:
647		if (val & ~SOF_TIMESTAMPING_MASK) {
648			ret = -EINVAL;
649			break;
650		}
651		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
652				  val & SOF_TIMESTAMPING_TX_HARDWARE);
653		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
654				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
655		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
656				  val & SOF_TIMESTAMPING_RX_HARDWARE);
657		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
658			sock_enable_timestamp(sk,
659					      SOCK_TIMESTAMPING_RX_SOFTWARE);
660		else
661			sock_disable_timestamp(sk,
662					       SOCK_TIMESTAMPING_RX_SOFTWARE);
663		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
664				  val & SOF_TIMESTAMPING_SOFTWARE);
665		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
666				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
667		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
668				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
669		break;
670
671	case SO_RCVLOWAT:
672		if (val < 0)
673			val = INT_MAX;
674		sk->sk_rcvlowat = val ? : 1;
675		break;
676
677	case SO_RCVTIMEO:
678		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
679		break;
680
681	case SO_SNDTIMEO:
682		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
683		break;
684
685	case SO_ATTACH_FILTER:
686		ret = -EINVAL;
687		if (optlen == sizeof(struct sock_fprog)) {
688			struct sock_fprog fprog;
689
690			ret = -EFAULT;
691			if (copy_from_user(&fprog, optval, sizeof(fprog)))
692				break;
693
694			ret = sk_attach_filter(&fprog, sk);
695		}
696		break;
697
698	case SO_DETACH_FILTER:
699		ret = sk_detach_filter(sk);
700		break;
701
702	case SO_PASSSEC:
703		if (valbool)
704			set_bit(SOCK_PASSSEC, &sock->flags);
705		else
706			clear_bit(SOCK_PASSSEC, &sock->flags);
707		break;
708	case SO_MARK:
709		if (!capable(CAP_NET_ADMIN))
710			ret = -EPERM;
711		else
712			sk->sk_mark = val;
713		break;
714
715		/* We implement the SO_SNDLOWAT etc to
716		   not be settable (1003.1g 5.3) */
717	case SO_RXQ_OVFL:
718		if (valbool)
719			sock_set_flag(sk, SOCK_RXQ_OVFL);
720		else
721			sock_reset_flag(sk, SOCK_RXQ_OVFL);
722		break;
723	default:
724		ret = -ENOPROTOOPT;
725		break;
726	}
727	release_sock(sk);
728	return ret;
729}
730EXPORT_SYMBOL(sock_setsockopt);
731
732
733int sock_getsockopt(struct socket *sock, int level, int optname,
734		    char __user *optval, int __user *optlen)
735{
736	struct sock *sk = sock->sk;
737
738	union {
739		int val;
740		struct linger ling;
741		struct timeval tm;
742	} v;
743
744	unsigned int lv = sizeof(int);
745	int len;
746
747	if (get_user(len, optlen))
748		return -EFAULT;
749	if (len < 0)
750		return -EINVAL;
751
752	memset(&v, 0, sizeof(v));
753
754	switch (optname) {
755	case SO_DEBUG:
756		v.val = sock_flag(sk, SOCK_DBG);
757		break;
758
759	case SO_DONTROUTE:
760		v.val = sock_flag(sk, SOCK_LOCALROUTE);
761		break;
762
763	case SO_BROADCAST:
764		v.val = !!sock_flag(sk, SOCK_BROADCAST);
765		break;
766
767	case SO_SNDBUF:
768		v.val = sk->sk_sndbuf;
769		break;
770
771	case SO_RCVBUF:
772		v.val = sk->sk_rcvbuf;
773		break;
774
775	case SO_REUSEADDR:
776		v.val = sk->sk_reuse;
777		break;
778
779	case SO_KEEPALIVE:
780		v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
781		break;
782
783	case SO_TYPE:
784		v.val = sk->sk_type;
785		break;
786
787	case SO_PROTOCOL:
788		v.val = sk->sk_protocol;
789		break;
790
791	case SO_DOMAIN:
792		v.val = sk->sk_family;
793		break;
794
795	case SO_ERROR:
796		v.val = -sock_error(sk);
797		if (v.val == 0)
798			v.val = xchg(&sk->sk_err_soft, 0);
799		break;
800
801	case SO_OOBINLINE:
802		v.val = !!sock_flag(sk, SOCK_URGINLINE);
803		break;
804
805	case SO_NO_CHECK:
806		v.val = sk->sk_no_check;
807		break;
808
809	case SO_PRIORITY:
810		v.val = sk->sk_priority;
811		break;
812
813	case SO_LINGER:
814		lv		= sizeof(v.ling);
815		v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
816		v.ling.l_linger	= sk->sk_lingertime / HZ;
817		break;
818
819	case SO_BSDCOMPAT:
820		sock_warn_obsolete_bsdism("getsockopt");
821		break;
822
823	case SO_TIMESTAMP:
824		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
825				!sock_flag(sk, SOCK_RCVTSTAMPNS);
826		break;
827
828	case SO_TIMESTAMPNS:
829		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
830		break;
831
832	case SO_TIMESTAMPING:
833		v.val = 0;
834		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
835			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
836		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
837			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
838		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
839			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
840		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
841			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
842		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
843			v.val |= SOF_TIMESTAMPING_SOFTWARE;
844		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
845			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
846		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
847			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
848		break;
849
850	case SO_RCVTIMEO:
851		lv = sizeof(struct timeval);
852		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
853			v.tm.tv_sec = 0;
854			v.tm.tv_usec = 0;
855		} else {
856			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
857			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
858		}
859		break;
860
861	case SO_SNDTIMEO:
862		lv = sizeof(struct timeval);
863		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
864			v.tm.tv_sec = 0;
865			v.tm.tv_usec = 0;
866		} else {
867			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
868			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
869		}
870		break;
871
872	case SO_RCVLOWAT:
873		v.val = sk->sk_rcvlowat;
874		break;
875
876	case SO_SNDLOWAT:
877		v.val = 1;
878		break;
879
880	case SO_PASSCRED:
881		v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
882		break;
883
884	case SO_PEERCRED:
885		if (len > sizeof(sk->sk_peercred))
886			len = sizeof(sk->sk_peercred);
887		if (copy_to_user(optval, &sk->sk_peercred, len))
888			return -EFAULT;
889		goto lenout;
890
891	case SO_PEERNAME:
892	{
893		char address[128];
894
895		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
896			return -ENOTCONN;
897		if (lv < len)
898			return -EINVAL;
899		if (copy_to_user(optval, address, len))
900			return -EFAULT;
901		goto lenout;
902	}
903
904	/* Dubious BSD thing... Probably nobody even uses it, but
905	 * the UNIX standard wants it for whatever reason... -DaveM
906	 */
907	case SO_ACCEPTCONN:
908		v.val = sk->sk_state == TCP_LISTEN;
909		break;
910
911	case SO_PASSSEC:
912		v.val = test_bit(SOCK_PASSSEC, &sock->flags) ? 1 : 0;
913		break;
914
915	case SO_PEERSEC:
916		return security_socket_getpeersec_stream(sock, optval, optlen, len);
917
918	case SO_MARK:
919		v.val = sk->sk_mark;
920		break;
921
922	case SO_RXQ_OVFL:
923		v.val = !!sock_flag(sk, SOCK_RXQ_OVFL);
924		break;
925
926	default:
927		return -ENOPROTOOPT;
928	}
929
930	if (len > lv)
931		len = lv;
932	if (copy_to_user(optval, &v, len))
933		return -EFAULT;
934lenout:
935	if (put_user(len, optlen))
936		return -EFAULT;
937	return 0;
938}
939
940/*
941 * Initialize an sk_lock.
942 *
943 * (We also register the sk_lock with the lock validator.)
944 */
945static inline void sock_lock_init(struct sock *sk)
946{
947	sock_lock_init_class_and_name(sk,
948			af_family_slock_key_strings[sk->sk_family],
949			af_family_slock_keys + sk->sk_family,
950			af_family_key_strings[sk->sk_family],
951			af_family_keys + sk->sk_family);
952}
953
954/*
955 * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
956 * even temporarly, because of RCU lookups. sk_node should also be left as is.
957 */
958static void sock_copy(struct sock *nsk, const struct sock *osk)
959{
960#ifdef CONFIG_SECURITY_NETWORK
961	void *sptr = nsk->sk_security;
962#endif
963	BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) !=
964		     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt) +
965		     sizeof(osk->sk_tx_queue_mapping));
966	memcpy(&nsk->sk_copy_start, &osk->sk_copy_start,
967	       osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start));
968#ifdef CONFIG_SECURITY_NETWORK
969	nsk->sk_security = sptr;
970	security_sk_clone(osk, nsk);
971#endif
972}
973
974static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
975		int family)
976{
977	struct sock *sk;
978	struct kmem_cache *slab;
979
980	slab = prot->slab;
981	if (slab != NULL) {
982		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
983		if (!sk)
984			return sk;
985		if (priority & __GFP_ZERO) {
986			/*
987			 * caches using SLAB_DESTROY_BY_RCU should let
988			 * sk_node.next un-modified. Special care is taken
989			 * when initializing object to zero.
990			 */
991			if (offsetof(struct sock, sk_node.next) != 0)
992				memset(sk, 0, offsetof(struct sock, sk_node.next));
993			memset(&sk->sk_node.pprev, 0,
994			       prot->obj_size - offsetof(struct sock,
995							 sk_node.pprev));
996		}
997	}
998	else
999		sk = kmalloc(prot->obj_size, priority);
1000
1001	if (sk != NULL) {
1002		kmemcheck_annotate_bitfield(sk, flags);
1003
1004		if (security_sk_alloc(sk, family, priority))
1005			goto out_free;
1006
1007		if (!try_module_get(prot->owner))
1008			goto out_free_sec;
1009		sk_tx_queue_clear(sk);
1010	}
1011
1012	return sk;
1013
1014out_free_sec:
1015	security_sk_free(sk);
1016out_free:
1017	if (slab != NULL)
1018		kmem_cache_free(slab, sk);
1019	else
1020		kfree(sk);
1021	return NULL;
1022}
1023
1024static void sk_prot_free(struct proto *prot, struct sock *sk)
1025{
1026	struct kmem_cache *slab;
1027	struct module *owner;
1028
1029	owner = prot->owner;
1030	slab = prot->slab;
1031
1032	security_sk_free(sk);
1033	if (slab != NULL)
1034		kmem_cache_free(slab, sk);
1035	else
1036		kfree(sk);
1037	module_put(owner);
1038}
1039
1040/**
1041 *	sk_alloc - All socket objects are allocated here
1042 *	@net: the applicable net namespace
1043 *	@family: protocol family
1044 *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
1045 *	@prot: struct proto associated with this new sock instance
1046 */
1047struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
1048		      struct proto *prot)
1049{
1050	struct sock *sk;
1051
1052	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
1053	if (sk) {
1054		sk->sk_family = family;
1055		/*
1056		 * See comment in struct sock definition to understand
1057		 * why we need sk_prot_creator -acme
1058		 */
1059		sk->sk_prot = sk->sk_prot_creator = prot;
1060		sock_lock_init(sk);
1061		sock_net_set(sk, get_net(net));
1062		atomic_set(&sk->sk_wmem_alloc, 1);
1063	}
1064
1065	return sk;
1066}
1067EXPORT_SYMBOL(sk_alloc);
1068
1069static void __sk_free(struct sock *sk)
1070{
1071	struct sk_filter *filter;
1072
1073	if (sk->sk_destruct)
1074		sk->sk_destruct(sk);
1075
1076	filter = rcu_dereference_check(sk->sk_filter,
1077				       atomic_read(&sk->sk_wmem_alloc) == 0);
1078	if (filter) {
1079		sk_filter_uncharge(sk, filter);
1080		rcu_assign_pointer(sk->sk_filter, NULL);
1081	}
1082
1083	sock_disable_timestamp(sk, SOCK_TIMESTAMP);
1084	sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
1085
1086	if (atomic_read(&sk->sk_omem_alloc))
1087		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
1088		       __func__, atomic_read(&sk->sk_omem_alloc));
1089
1090	put_net(sock_net(sk));
1091	sk_prot_free(sk->sk_prot_creator, sk);
1092}
1093
1094void sk_free(struct sock *sk)
1095{
1096	/*
1097	 * We substract one from sk_wmem_alloc and can know if
1098	 * some packets are still in some tx queue.
1099	 * If not null, sock_wfree() will call __sk_free(sk) later
1100	 */
1101	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1102		__sk_free(sk);
1103}
1104EXPORT_SYMBOL(sk_free);
1105
1106/*
1107 * Last sock_put should drop referrence to sk->sk_net. It has already
1108 * been dropped in sk_change_net. Taking referrence to stopping namespace
1109 * is not an option.
1110 * Take referrence to a socket to remove it from hash _alive_ and after that
1111 * destroy it in the context of init_net.
1112 */
1113void sk_release_kernel(struct sock *sk)
1114{
1115	if (sk == NULL || sk->sk_socket == NULL)
1116		return;
1117
1118	sock_hold(sk);
1119	sock_release(sk->sk_socket);
1120	release_net(sock_net(sk));
1121	sock_net_set(sk, get_net(&init_net));
1122	sock_put(sk);
1123}
1124EXPORT_SYMBOL(sk_release_kernel);
1125
1126struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1127{
1128	struct sock *newsk;
1129
1130	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1131	if (newsk != NULL) {
1132		struct sk_filter *filter;
1133
1134		sock_copy(newsk, sk);
1135
1136		/* SANITY */
1137		get_net(sock_net(newsk));
1138		sk_node_init(&newsk->sk_node);
1139		sock_lock_init(newsk);
1140		bh_lock_sock(newsk);
1141		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1142
1143		atomic_set(&newsk->sk_rmem_alloc, 0);
1144		/*
1145		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1146		 */
1147		atomic_set(&newsk->sk_wmem_alloc, 1);
1148		atomic_set(&newsk->sk_omem_alloc, 0);
1149		skb_queue_head_init(&newsk->sk_receive_queue);
1150		skb_queue_head_init(&newsk->sk_write_queue);
1151#ifdef CONFIG_NET_DMA
1152		skb_queue_head_init(&newsk->sk_async_wait_queue);
1153#endif
1154
1155		rwlock_init(&newsk->sk_dst_lock);
1156		rwlock_init(&newsk->sk_callback_lock);
1157		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1158				af_callback_keys + newsk->sk_family,
1159				af_family_clock_key_strings[newsk->sk_family]);
1160
1161		newsk->sk_dst_cache	= NULL;
1162		newsk->sk_wmem_queued	= 0;
1163		newsk->sk_forward_alloc = 0;
1164		newsk->sk_send_head	= NULL;
1165		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1166
1167		sock_reset_flag(newsk, SOCK_DONE);
1168		skb_queue_head_init(&newsk->sk_error_queue);
1169
1170		filter = newsk->sk_filter;
1171		if (filter != NULL)
1172			sk_filter_charge(newsk, filter);
1173
1174		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1175			/* It is still raw copy of parent, so invalidate
1176			 * destructor and make plain sk_free() */
1177			newsk->sk_destruct = NULL;
1178			sk_free(newsk);
1179			newsk = NULL;
1180			goto out;
1181		}
1182
1183		newsk->sk_err	   = 0;
1184		newsk->sk_priority = 0;
1185		/*
1186		 * Before updating sk_refcnt, we must commit prior changes to memory
1187		 * (Documentation/RCU/rculist_nulls.txt for details)
1188		 */
1189		smp_wmb();
1190		atomic_set(&newsk->sk_refcnt, 2);
1191
1192		/*
1193		 * Increment the counter in the same struct proto as the master
1194		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1195		 * is the same as sk->sk_prot->socks, as this field was copied
1196		 * with memcpy).
1197		 *
1198		 * This _changes_ the previous behaviour, where
1199		 * tcp_create_openreq_child always was incrementing the
1200		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1201		 * to be taken into account in all callers. -acme
1202		 */
1203		sk_refcnt_debug_inc(newsk);
1204		sk_set_socket(newsk, NULL);
1205		newsk->sk_sleep	 = NULL;
1206
1207		if (newsk->sk_prot->sockets_allocated)
1208			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1209
1210		if (sock_flag(newsk, SOCK_TIMESTAMP) ||
1211		    sock_flag(newsk, SOCK_TIMESTAMPING_RX_SOFTWARE))
1212			net_enable_timestamp();
1213	}
1214out:
1215	return newsk;
1216}
1217EXPORT_SYMBOL_GPL(sk_clone);
1218
1219void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1220{
1221	__sk_dst_set(sk, dst);
1222	sk->sk_route_caps = dst->dev->features;
1223	if (sk->sk_route_caps & NETIF_F_GSO)
1224		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1225	if (sk_can_gso(sk)) {
1226		if (dst->header_len) {
1227			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1228		} else {
1229			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1230			sk->sk_gso_max_size = dst->dev->gso_max_size;
1231		}
1232	}
1233}
1234EXPORT_SYMBOL_GPL(sk_setup_caps);
1235
1236void __init sk_init(void)
1237{
1238	if (totalram_pages <= 4096) {
1239		sysctl_wmem_max = 32767;
1240		sysctl_rmem_max = 32767;
1241		sysctl_wmem_default = 32767;
1242		sysctl_rmem_default = 32767;
1243	} else if (totalram_pages >= 131072) {
1244		sysctl_wmem_max = 131071;
1245		sysctl_rmem_max = 131071;
1246	}
1247}
1248
1249/*
1250 *	Simple resource managers for sockets.
1251 */
1252
1253
1254/*
1255 * Write buffer destructor automatically called from kfree_skb.
1256 */
1257void sock_wfree(struct sk_buff *skb)
1258{
1259	struct sock *sk = skb->sk;
1260	unsigned int len = skb->truesize;
1261
1262	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1263		/*
1264		 * Keep a reference on sk_wmem_alloc, this will be released
1265		 * after sk_write_space() call
1266		 */
1267		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1268		sk->sk_write_space(sk);
1269		len = 1;
1270	}
1271	/*
1272	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1273	 * could not do because of in-flight packets
1274	 */
1275	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1276		__sk_free(sk);
1277}
1278EXPORT_SYMBOL(sock_wfree);
1279
1280/*
1281 * Read buffer destructor automatically called from kfree_skb.
1282 */
1283void sock_rfree(struct sk_buff *skb)
1284{
1285	struct sock *sk = skb->sk;
1286
1287	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1288	sk_mem_uncharge(skb->sk, skb->truesize);
1289}
1290EXPORT_SYMBOL(sock_rfree);
1291
1292
1293int sock_i_uid(struct sock *sk)
1294{
1295	int uid;
1296
1297	read_lock(&sk->sk_callback_lock);
1298	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1299	read_unlock(&sk->sk_callback_lock);
1300	return uid;
1301}
1302EXPORT_SYMBOL(sock_i_uid);
1303
1304unsigned long sock_i_ino(struct sock *sk)
1305{
1306	unsigned long ino;
1307
1308	read_lock(&sk->sk_callback_lock);
1309	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1310	read_unlock(&sk->sk_callback_lock);
1311	return ino;
1312}
1313EXPORT_SYMBOL(sock_i_ino);
1314
1315/*
1316 * Allocate a skb from the socket's send buffer.
1317 */
1318struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1319			     gfp_t priority)
1320{
1321	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1322		struct sk_buff *skb = alloc_skb(size, priority);
1323		if (skb) {
1324			skb_set_owner_w(skb, sk);
1325			return skb;
1326		}
1327	}
1328	return NULL;
1329}
1330EXPORT_SYMBOL(sock_wmalloc);
1331
1332/*
1333 * Allocate a skb from the socket's receive buffer.
1334 */
1335struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1336			     gfp_t priority)
1337{
1338	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1339		struct sk_buff *skb = alloc_skb(size, priority);
1340		if (skb) {
1341			skb_set_owner_r(skb, sk);
1342			return skb;
1343		}
1344	}
1345	return NULL;
1346}
1347
1348/*
1349 * Allocate a memory block from the socket's option memory buffer.
1350 */
1351void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1352{
1353	if ((unsigned)size <= sysctl_optmem_max &&
1354	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1355		void *mem;
1356		/* First do the add, to avoid the race if kmalloc
1357		 * might sleep.
1358		 */
1359		atomic_add(size, &sk->sk_omem_alloc);
1360		mem = kmalloc(size, priority);
1361		if (mem)
1362			return mem;
1363		atomic_sub(size, &sk->sk_omem_alloc);
1364	}
1365	return NULL;
1366}
1367EXPORT_SYMBOL(sock_kmalloc);
1368
1369/*
1370 * Free an option memory block.
1371 */
1372void sock_kfree_s(struct sock *sk, void *mem, int size)
1373{
1374	kfree(mem);
1375	atomic_sub(size, &sk->sk_omem_alloc);
1376}
1377EXPORT_SYMBOL(sock_kfree_s);
1378
1379/* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1380   I think, these locks should be removed for datagram sockets.
1381 */
1382static long sock_wait_for_wmem(struct sock *sk, long timeo)
1383{
1384	DEFINE_WAIT(wait);
1385
1386	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1387	for (;;) {
1388		if (!timeo)
1389			break;
1390		if (signal_pending(current))
1391			break;
1392		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1393		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1394		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1395			break;
1396		if (sk->sk_shutdown & SEND_SHUTDOWN)
1397			break;
1398		if (sk->sk_err)
1399			break;
1400		timeo = schedule_timeout(timeo);
1401	}
1402	finish_wait(sk->sk_sleep, &wait);
1403	return timeo;
1404}
1405
1406
1407/*
1408 *	Generic send/receive buffer handlers
1409 */
1410
1411struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1412				     unsigned long data_len, int noblock,
1413				     int *errcode)
1414{
1415	struct sk_buff *skb;
1416	gfp_t gfp_mask;
1417	long timeo;
1418	int err;
1419
1420	gfp_mask = sk->sk_allocation;
1421	if (gfp_mask & __GFP_WAIT)
1422		gfp_mask |= __GFP_REPEAT;
1423
1424	timeo = sock_sndtimeo(sk, noblock);
1425	while (1) {
1426		err = sock_error(sk);
1427		if (err != 0)
1428			goto failure;
1429
1430		err = -EPIPE;
1431		if (sk->sk_shutdown & SEND_SHUTDOWN)
1432			goto failure;
1433
1434		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1435			skb = alloc_skb(header_len, gfp_mask);
1436			if (skb) {
1437				int npages;
1438				int i;
1439
1440				/* No pages, we're done... */
1441				if (!data_len)
1442					break;
1443
1444				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1445				skb->truesize += data_len;
1446				skb_shinfo(skb)->nr_frags = npages;
1447				for (i = 0; i < npages; i++) {
1448					struct page *page;
1449					skb_frag_t *frag;
1450
1451					page = alloc_pages(sk->sk_allocation, 0);
1452					if (!page) {
1453						err = -ENOBUFS;
1454						skb_shinfo(skb)->nr_frags = i;
1455						kfree_skb(skb);
1456						goto failure;
1457					}
1458
1459					frag = &skb_shinfo(skb)->frags[i];
1460					frag->page = page;
1461					frag->page_offset = 0;
1462					frag->size = (data_len >= PAGE_SIZE ?
1463						      PAGE_SIZE :
1464						      data_len);
1465					data_len -= PAGE_SIZE;
1466				}
1467
1468				/* Full success... */
1469				break;
1470			}
1471			err = -ENOBUFS;
1472			goto failure;
1473		}
1474		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1475		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1476		err = -EAGAIN;
1477		if (!timeo)
1478			goto failure;
1479		if (signal_pending(current))
1480			goto interrupted;
1481		timeo = sock_wait_for_wmem(sk, timeo);
1482	}
1483
1484	skb_set_owner_w(skb, sk);
1485	return skb;
1486
1487interrupted:
1488	err = sock_intr_errno(timeo);
1489failure:
1490	*errcode = err;
1491	return NULL;
1492}
1493EXPORT_SYMBOL(sock_alloc_send_pskb);
1494
1495struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1496				    int noblock, int *errcode)
1497{
1498	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1499}
1500EXPORT_SYMBOL(sock_alloc_send_skb);
1501
1502static void __lock_sock(struct sock *sk)
1503{
1504	DEFINE_WAIT(wait);
1505
1506	for (;;) {
1507		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1508					TASK_UNINTERRUPTIBLE);
1509		spin_unlock_bh(&sk->sk_lock.slock);
1510		schedule();
1511		spin_lock_bh(&sk->sk_lock.slock);
1512		if (!sock_owned_by_user(sk))
1513			break;
1514	}
1515	finish_wait(&sk->sk_lock.wq, &wait);
1516}
1517
1518static void __release_sock(struct sock *sk)
1519{
1520	struct sk_buff *skb = sk->sk_backlog.head;
1521
1522	do {
1523		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1524		bh_unlock_sock(sk);
1525
1526		do {
1527			struct sk_buff *next = skb->next;
1528
1529			skb->next = NULL;
1530			sk_backlog_rcv(sk, skb);
1531
1532			/*
1533			 * We are in process context here with softirqs
1534			 * disabled, use cond_resched_softirq() to preempt.
1535			 * This is safe to do because we've taken the backlog
1536			 * queue private:
1537			 */
1538			cond_resched_softirq();
1539
1540			skb = next;
1541		} while (skb != NULL);
1542
1543		bh_lock_sock(sk);
1544	} while ((skb = sk->sk_backlog.head) != NULL);
1545}
1546
1547/**
1548 * sk_wait_data - wait for data to arrive at sk_receive_queue
1549 * @sk:    sock to wait on
1550 * @timeo: for how long
1551 *
1552 * Now socket state including sk->sk_err is changed only under lock,
1553 * hence we may omit checks after joining wait queue.
1554 * We check receive queue before schedule() only as optimization;
1555 * it is very likely that release_sock() added new data.
1556 */
1557int sk_wait_data(struct sock *sk, long *timeo)
1558{
1559	int rc;
1560	DEFINE_WAIT(wait);
1561
1562	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1563	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1564	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1565	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1566	finish_wait(sk->sk_sleep, &wait);
1567	return rc;
1568}
1569EXPORT_SYMBOL(sk_wait_data);
1570
1571/**
1572 *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1573 *	@sk: socket
1574 *	@size: memory size to allocate
1575 *	@kind: allocation type
1576 *
1577 *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1578 *	rmem allocation. This function assumes that protocols which have
1579 *	memory_pressure use sk_wmem_queued as write buffer accounting.
1580 */
1581int __sk_mem_schedule(struct sock *sk, int size, int kind)
1582{
1583	struct proto *prot = sk->sk_prot;
1584	int amt = sk_mem_pages(size);
1585	int allocated;
1586
1587	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1588	allocated = atomic_add_return(amt, prot->memory_allocated);
1589
1590	/* Under limit. */
1591	if (allocated <= prot->sysctl_mem[0]) {
1592		if (prot->memory_pressure && *prot->memory_pressure)
1593			*prot->memory_pressure = 0;
1594		return 1;
1595	}
1596
1597	/* Under pressure. */
1598	if (allocated > prot->sysctl_mem[1])
1599		if (prot->enter_memory_pressure)
1600			prot->enter_memory_pressure(sk);
1601
1602	/* Over hard limit. */
1603	if (allocated > prot->sysctl_mem[2])
1604		goto suppress_allocation;
1605
1606	/* guarantee minimum buffer size under pressure */
1607	if (kind == SK_MEM_RECV) {
1608		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1609			return 1;
1610	} else { /* SK_MEM_SEND */
1611		if (sk->sk_type == SOCK_STREAM) {
1612			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1613				return 1;
1614		} else if (atomic_read(&sk->sk_wmem_alloc) <
1615			   prot->sysctl_wmem[0])
1616				return 1;
1617	}
1618
1619	if (prot->memory_pressure) {
1620		int alloc;
1621
1622		if (!*prot->memory_pressure)
1623			return 1;
1624		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1625		if (prot->sysctl_mem[2] > alloc *
1626		    sk_mem_pages(sk->sk_wmem_queued +
1627				 atomic_read(&sk->sk_rmem_alloc) +
1628				 sk->sk_forward_alloc))
1629			return 1;
1630	}
1631
1632suppress_allocation:
1633
1634	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1635		sk_stream_moderate_sndbuf(sk);
1636
1637		/* Fail only if socket is _under_ its sndbuf.
1638		 * In this case we cannot block, so that we have to fail.
1639		 */
1640		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1641			return 1;
1642	}
1643
1644	/* Alas. Undo changes. */
1645	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1646	atomic_sub(amt, prot->memory_allocated);
1647	return 0;
1648}
1649EXPORT_SYMBOL(__sk_mem_schedule);
1650
1651/**
1652 *	__sk_reclaim - reclaim memory_allocated
1653 *	@sk: socket
1654 */
1655void __sk_mem_reclaim(struct sock *sk)
1656{
1657	struct proto *prot = sk->sk_prot;
1658
1659	atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1660		   prot->memory_allocated);
1661	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1662
1663	if (prot->memory_pressure && *prot->memory_pressure &&
1664	    (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1665		*prot->memory_pressure = 0;
1666}
1667EXPORT_SYMBOL(__sk_mem_reclaim);
1668
1669
1670/*
1671 * Set of default routines for initialising struct proto_ops when
1672 * the protocol does not support a particular function. In certain
1673 * cases where it makes no sense for a protocol to have a "do nothing"
1674 * function, some default processing is provided.
1675 */
1676
1677int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1678{
1679	return -EOPNOTSUPP;
1680}
1681EXPORT_SYMBOL(sock_no_bind);
1682
1683int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1684		    int len, int flags)
1685{
1686	return -EOPNOTSUPP;
1687}
1688EXPORT_SYMBOL(sock_no_connect);
1689
1690int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1691{
1692	return -EOPNOTSUPP;
1693}
1694EXPORT_SYMBOL(sock_no_socketpair);
1695
1696int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1697{
1698	return -EOPNOTSUPP;
1699}
1700EXPORT_SYMBOL(sock_no_accept);
1701
1702int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1703		    int *len, int peer)
1704{
1705	return -EOPNOTSUPP;
1706}
1707EXPORT_SYMBOL(sock_no_getname);
1708
1709unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1710{
1711	return 0;
1712}
1713EXPORT_SYMBOL(sock_no_poll);
1714
1715int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1716{
1717	return -EOPNOTSUPP;
1718}
1719EXPORT_SYMBOL(sock_no_ioctl);
1720
1721int sock_no_listen(struct socket *sock, int backlog)
1722{
1723	return -EOPNOTSUPP;
1724}
1725EXPORT_SYMBOL(sock_no_listen);
1726
1727int sock_no_shutdown(struct socket *sock, int how)
1728{
1729	return -EOPNOTSUPP;
1730}
1731EXPORT_SYMBOL(sock_no_shutdown);
1732
1733int sock_no_setsockopt(struct socket *sock, int level, int optname,
1734		    char __user *optval, unsigned int optlen)
1735{
1736	return -EOPNOTSUPP;
1737}
1738EXPORT_SYMBOL(sock_no_setsockopt);
1739
1740int sock_no_getsockopt(struct socket *sock, int level, int optname,
1741		    char __user *optval, int __user *optlen)
1742{
1743	return -EOPNOTSUPP;
1744}
1745EXPORT_SYMBOL(sock_no_getsockopt);
1746
1747int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1748		    size_t len)
1749{
1750	return -EOPNOTSUPP;
1751}
1752EXPORT_SYMBOL(sock_no_sendmsg);
1753
1754int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1755		    size_t len, int flags)
1756{
1757	return -EOPNOTSUPP;
1758}
1759EXPORT_SYMBOL(sock_no_recvmsg);
1760
1761int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1762{
1763	/* Mirror missing mmap method error code */
1764	return -ENODEV;
1765}
1766EXPORT_SYMBOL(sock_no_mmap);
1767
1768ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1769{
1770	ssize_t res;
1771	struct msghdr msg = {.msg_flags = flags};
1772	struct kvec iov;
1773	char *kaddr = kmap(page);
1774	iov.iov_base = kaddr + offset;
1775	iov.iov_len = size;
1776	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1777	kunmap(page);
1778	return res;
1779}
1780EXPORT_SYMBOL(sock_no_sendpage);
1781
1782/*
1783 *	Default Socket Callbacks
1784 */
1785
1786static void sock_def_wakeup(struct sock *sk)
1787{
1788	read_lock(&sk->sk_callback_lock);
1789	if (sk_has_sleeper(sk))
1790		wake_up_interruptible_all(sk->sk_sleep);
1791	read_unlock(&sk->sk_callback_lock);
1792}
1793
1794static void sock_def_error_report(struct sock *sk)
1795{
1796	read_lock(&sk->sk_callback_lock);
1797	if (sk_has_sleeper(sk))
1798		wake_up_interruptible_poll(sk->sk_sleep, POLLERR);
1799	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1800	read_unlock(&sk->sk_callback_lock);
1801}
1802
1803static void sock_def_readable(struct sock *sk, int len)
1804{
1805	read_lock(&sk->sk_callback_lock);
1806	if (sk_has_sleeper(sk))
1807		wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN |
1808						POLLRDNORM | POLLRDBAND);
1809	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1810	read_unlock(&sk->sk_callback_lock);
1811}
1812
1813static void sock_def_write_space(struct sock *sk)
1814{
1815	read_lock(&sk->sk_callback_lock);
1816
1817	/* Do not wake up a writer until he can make "significant"
1818	 * progress.  --DaveM
1819	 */
1820	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1821		if (sk_has_sleeper(sk))
1822			wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
1823						POLLWRNORM | POLLWRBAND);
1824
1825		/* Should agree with poll, otherwise some programs break */
1826		if (sock_writeable(sk))
1827			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1828	}
1829
1830	read_unlock(&sk->sk_callback_lock);
1831}
1832
1833static void sock_def_destruct(struct sock *sk)
1834{
1835	kfree(sk->sk_protinfo);
1836}
1837
1838void sk_send_sigurg(struct sock *sk)
1839{
1840	if (sk->sk_socket && sk->sk_socket->file)
1841		if (send_sigurg(&sk->sk_socket->file->f_owner))
1842			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1843}
1844EXPORT_SYMBOL(sk_send_sigurg);
1845
1846void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1847		    unsigned long expires)
1848{
1849	if (!mod_timer(timer, expires))
1850		sock_hold(sk);
1851}
1852EXPORT_SYMBOL(sk_reset_timer);
1853
1854void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1855{
1856	if (timer_pending(timer) && del_timer(timer))
1857		__sock_put(sk);
1858}
1859EXPORT_SYMBOL(sk_stop_timer);
1860
1861void sock_init_data(struct socket *sock, struct sock *sk)
1862{
1863	skb_queue_head_init(&sk->sk_receive_queue);
1864	skb_queue_head_init(&sk->sk_write_queue);
1865	skb_queue_head_init(&sk->sk_error_queue);
1866#ifdef CONFIG_NET_DMA
1867	skb_queue_head_init(&sk->sk_async_wait_queue);
1868#endif
1869
1870	sk->sk_send_head	=	NULL;
1871
1872	init_timer(&sk->sk_timer);
1873
1874	sk->sk_allocation	=	GFP_KERNEL;
1875	sk->sk_rcvbuf		=	sysctl_rmem_default;
1876	sk->sk_sndbuf		=	sysctl_wmem_default;
1877	sk->sk_state		=	TCP_CLOSE;
1878	sk_set_socket(sk, sock);
1879
1880	sock_set_flag(sk, SOCK_ZAPPED);
1881
1882	if (sock) {
1883		sk->sk_type	=	sock->type;
1884		sk->sk_sleep	=	&sock->wait;
1885		sock->sk	=	sk;
1886	} else
1887		sk->sk_sleep	=	NULL;
1888
1889	rwlock_init(&sk->sk_dst_lock);
1890	rwlock_init(&sk->sk_callback_lock);
1891	lockdep_set_class_and_name(&sk->sk_callback_lock,
1892			af_callback_keys + sk->sk_family,
1893			af_family_clock_key_strings[sk->sk_family]);
1894
1895	sk->sk_state_change	=	sock_def_wakeup;
1896	sk->sk_data_ready	=	sock_def_readable;
1897	sk->sk_write_space	=	sock_def_write_space;
1898	sk->sk_error_report	=	sock_def_error_report;
1899	sk->sk_destruct		=	sock_def_destruct;
1900
1901	sk->sk_sndmsg_page	=	NULL;
1902	sk->sk_sndmsg_off	=	0;
1903
1904	sk->sk_peercred.pid 	=	0;
1905	sk->sk_peercred.uid	=	-1;
1906	sk->sk_peercred.gid	=	-1;
1907	sk->sk_write_pending	=	0;
1908	sk->sk_rcvlowat		=	1;
1909	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1910	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1911
1912	sk->sk_stamp = ktime_set(-1L, 0);
1913
1914	/*
1915	 * Before updating sk_refcnt, we must commit prior changes to memory
1916	 * (Documentation/RCU/rculist_nulls.txt for details)
1917	 */
1918	smp_wmb();
1919	atomic_set(&sk->sk_refcnt, 1);
1920	atomic_set(&sk->sk_drops, 0);
1921}
1922EXPORT_SYMBOL(sock_init_data);
1923
1924void lock_sock_nested(struct sock *sk, int subclass)
1925{
1926	might_sleep();
1927	spin_lock_bh(&sk->sk_lock.slock);
1928	if (sk->sk_lock.owned)
1929		__lock_sock(sk);
1930	sk->sk_lock.owned = 1;
1931	spin_unlock(&sk->sk_lock.slock);
1932	/*
1933	 * The sk_lock has mutex_lock() semantics here:
1934	 */
1935	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
1936	local_bh_enable();
1937}
1938EXPORT_SYMBOL(lock_sock_nested);
1939
1940void release_sock(struct sock *sk)
1941{
1942	/*
1943	 * The sk_lock has mutex_unlock() semantics:
1944	 */
1945	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1946
1947	spin_lock_bh(&sk->sk_lock.slock);
1948	if (sk->sk_backlog.tail)
1949		__release_sock(sk);
1950	sk->sk_lock.owned = 0;
1951	if (waitqueue_active(&sk->sk_lock.wq))
1952		wake_up(&sk->sk_lock.wq);
1953	spin_unlock_bh(&sk->sk_lock.slock);
1954}
1955EXPORT_SYMBOL(release_sock);
1956
1957int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1958{
1959	struct timeval tv;
1960	if (!sock_flag(sk, SOCK_TIMESTAMP))
1961		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1962	tv = ktime_to_timeval(sk->sk_stamp);
1963	if (tv.tv_sec == -1)
1964		return -ENOENT;
1965	if (tv.tv_sec == 0) {
1966		sk->sk_stamp = ktime_get_real();
1967		tv = ktime_to_timeval(sk->sk_stamp);
1968	}
1969	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
1970}
1971EXPORT_SYMBOL(sock_get_timestamp);
1972
1973int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
1974{
1975	struct timespec ts;
1976	if (!sock_flag(sk, SOCK_TIMESTAMP))
1977		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1978	ts = ktime_to_timespec(sk->sk_stamp);
1979	if (ts.tv_sec == -1)
1980		return -ENOENT;
1981	if (ts.tv_sec == 0) {
1982		sk->sk_stamp = ktime_get_real();
1983		ts = ktime_to_timespec(sk->sk_stamp);
1984	}
1985	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
1986}
1987EXPORT_SYMBOL(sock_get_timestampns);
1988
1989void sock_enable_timestamp(struct sock *sk, int flag)
1990{
1991	if (!sock_flag(sk, flag)) {
1992		sock_set_flag(sk, flag);
1993		/*
1994		 * we just set one of the two flags which require net
1995		 * time stamping, but time stamping might have been on
1996		 * already because of the other one
1997		 */
1998		if (!sock_flag(sk,
1999				flag == SOCK_TIMESTAMP ?
2000				SOCK_TIMESTAMPING_RX_SOFTWARE :
2001				SOCK_TIMESTAMP))
2002			net_enable_timestamp();
2003	}
2004}
2005
2006/*
2007 *	Get a socket option on an socket.
2008 *
2009 *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2010 *	asynchronous errors should be reported by getsockopt. We assume
2011 *	this means if you specify SO_ERROR (otherwise whats the point of it).
2012 */
2013int sock_common_getsockopt(struct socket *sock, int level, int optname,
2014			   char __user *optval, int __user *optlen)
2015{
2016	struct sock *sk = sock->sk;
2017
2018	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2019}
2020EXPORT_SYMBOL(sock_common_getsockopt);
2021
2022#ifdef CONFIG_COMPAT
2023int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2024				  char __user *optval, int __user *optlen)
2025{
2026	struct sock *sk = sock->sk;
2027
2028	if (sk->sk_prot->compat_getsockopt != NULL)
2029		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2030						      optval, optlen);
2031	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2032}
2033EXPORT_SYMBOL(compat_sock_common_getsockopt);
2034#endif
2035
2036int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2037			struct msghdr *msg, size_t size, int flags)
2038{
2039	struct sock *sk = sock->sk;
2040	int addr_len = 0;
2041	int err;
2042
2043	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2044				   flags & ~MSG_DONTWAIT, &addr_len);
2045	if (err >= 0)
2046		msg->msg_namelen = addr_len;
2047	return err;
2048}
2049EXPORT_SYMBOL(sock_common_recvmsg);
2050
2051/*
2052 *	Set socket options on an inet socket.
2053 */
2054int sock_common_setsockopt(struct socket *sock, int level, int optname,
2055			   char __user *optval, unsigned int optlen)
2056{
2057	struct sock *sk = sock->sk;
2058
2059	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2060}
2061EXPORT_SYMBOL(sock_common_setsockopt);
2062
2063#ifdef CONFIG_COMPAT
2064int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2065				  char __user *optval, unsigned int optlen)
2066{
2067	struct sock *sk = sock->sk;
2068
2069	if (sk->sk_prot->compat_setsockopt != NULL)
2070		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2071						      optval, optlen);
2072	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2073}
2074EXPORT_SYMBOL(compat_sock_common_setsockopt);
2075#endif
2076
2077void sk_common_release(struct sock *sk)
2078{
2079	if (sk->sk_prot->destroy)
2080		sk->sk_prot->destroy(sk);
2081
2082	/*
2083	 * Observation: when sock_common_release is called, processes have
2084	 * no access to socket. But net still has.
2085	 * Step one, detach it from networking:
2086	 *
2087	 * A. Remove from hash tables.
2088	 */
2089
2090	sk->sk_prot->unhash(sk);
2091
2092	/*
2093	 * In this point socket cannot receive new packets, but it is possible
2094	 * that some packets are in flight because some CPU runs receiver and
2095	 * did hash table lookup before we unhashed socket. They will achieve
2096	 * receive queue and will be purged by socket destructor.
2097	 *
2098	 * Also we still have packets pending on receive queue and probably,
2099	 * our own packets waiting in device queues. sock_destroy will drain
2100	 * receive queue, but transmitted packets will delay socket destruction
2101	 * until the last reference will be released.
2102	 */
2103
2104	sock_orphan(sk);
2105
2106	xfrm_sk_free_policy(sk);
2107
2108	sk_refcnt_debug_release(sk);
2109	sock_put(sk);
2110}
2111EXPORT_SYMBOL(sk_common_release);
2112
2113static DEFINE_RWLOCK(proto_list_lock);
2114static LIST_HEAD(proto_list);
2115
2116#ifdef CONFIG_PROC_FS
2117#define PROTO_INUSE_NR	64	/* should be enough for the first time */
2118struct prot_inuse {
2119	int val[PROTO_INUSE_NR];
2120};
2121
2122static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2123
2124#ifdef CONFIG_NET_NS
2125void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2126{
2127	int cpu = smp_processor_id();
2128	per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
2129}
2130EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2131
2132int sock_prot_inuse_get(struct net *net, struct proto *prot)
2133{
2134	int cpu, idx = prot->inuse_idx;
2135	int res = 0;
2136
2137	for_each_possible_cpu(cpu)
2138		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2139
2140	return res >= 0 ? res : 0;
2141}
2142EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2143
2144static int sock_inuse_init_net(struct net *net)
2145{
2146	net->core.inuse = alloc_percpu(struct prot_inuse);
2147	return net->core.inuse ? 0 : -ENOMEM;
2148}
2149
2150static void sock_inuse_exit_net(struct net *net)
2151{
2152	free_percpu(net->core.inuse);
2153}
2154
2155static struct pernet_operations net_inuse_ops = {
2156	.init = sock_inuse_init_net,
2157	.exit = sock_inuse_exit_net,
2158};
2159
2160static __init int net_inuse_init(void)
2161{
2162	if (register_pernet_subsys(&net_inuse_ops))
2163		panic("Cannot initialize net inuse counters");
2164
2165	return 0;
2166}
2167
2168core_initcall(net_inuse_init);
2169#else
2170static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2171
2172void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2173{
2174	__get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
2175}
2176EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2177
2178int sock_prot_inuse_get(struct net *net, struct proto *prot)
2179{
2180	int cpu, idx = prot->inuse_idx;
2181	int res = 0;
2182
2183	for_each_possible_cpu(cpu)
2184		res += per_cpu(prot_inuse, cpu).val[idx];
2185
2186	return res >= 0 ? res : 0;
2187}
2188EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2189#endif
2190
2191static void assign_proto_idx(struct proto *prot)
2192{
2193	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2194
2195	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2196		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2197		return;
2198	}
2199
2200	set_bit(prot->inuse_idx, proto_inuse_idx);
2201}
2202
2203static void release_proto_idx(struct proto *prot)
2204{
2205	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2206		clear_bit(prot->inuse_idx, proto_inuse_idx);
2207}
2208#else
2209static inline void assign_proto_idx(struct proto *prot)
2210{
2211}
2212
2213static inline void release_proto_idx(struct proto *prot)
2214{
2215}
2216#endif
2217
2218int proto_register(struct proto *prot, int alloc_slab)
2219{
2220	if (alloc_slab) {
2221		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2222					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2223					NULL);
2224
2225		if (prot->slab == NULL) {
2226			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2227			       prot->name);
2228			goto out;
2229		}
2230
2231		if (prot->rsk_prot != NULL) {
2232			static const char mask[] = "request_sock_%s";
2233
2234			prot->rsk_prot->slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2235			if (prot->rsk_prot->slab_name == NULL)
2236				goto out_free_sock_slab;
2237
2238			sprintf(prot->rsk_prot->slab_name, mask, prot->name);
2239			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2240								 prot->rsk_prot->obj_size, 0,
2241								 SLAB_HWCACHE_ALIGN, NULL);
2242
2243			if (prot->rsk_prot->slab == NULL) {
2244				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2245				       prot->name);
2246				goto out_free_request_sock_slab_name;
2247			}
2248		}
2249
2250		if (prot->twsk_prot != NULL) {
2251			static const char mask[] = "tw_sock_%s";
2252
2253			prot->twsk_prot->twsk_slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
2254
2255			if (prot->twsk_prot->twsk_slab_name == NULL)
2256				goto out_free_request_sock_slab;
2257
2258			sprintf(prot->twsk_prot->twsk_slab_name, mask, prot->name);
2259			prot->twsk_prot->twsk_slab =
2260				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2261						  prot->twsk_prot->twsk_obj_size,
2262						  0,
2263						  SLAB_HWCACHE_ALIGN |
2264							prot->slab_flags,
2265						  NULL);
2266			if (prot->twsk_prot->twsk_slab == NULL)
2267				goto out_free_timewait_sock_slab_name;
2268		}
2269	}
2270
2271	write_lock(&proto_list_lock);
2272	list_add(&prot->node, &proto_list);
2273	assign_proto_idx(prot);
2274	write_unlock(&proto_list_lock);
2275	return 0;
2276
2277out_free_timewait_sock_slab_name:
2278	kfree(prot->twsk_prot->twsk_slab_name);
2279out_free_request_sock_slab:
2280	if (prot->rsk_prot && prot->rsk_prot->slab) {
2281		kmem_cache_destroy(prot->rsk_prot->slab);
2282		prot->rsk_prot->slab = NULL;
2283	}
2284out_free_request_sock_slab_name:
2285	kfree(prot->rsk_prot->slab_name);
2286out_free_sock_slab:
2287	kmem_cache_destroy(prot->slab);
2288	prot->slab = NULL;
2289out:
2290	return -ENOBUFS;
2291}
2292EXPORT_SYMBOL(proto_register);
2293
2294void proto_unregister(struct proto *prot)
2295{
2296	write_lock(&proto_list_lock);
2297	release_proto_idx(prot);
2298	list_del(&prot->node);
2299	write_unlock(&proto_list_lock);
2300
2301	if (prot->slab != NULL) {
2302		kmem_cache_destroy(prot->slab);
2303		prot->slab = NULL;
2304	}
2305
2306	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2307		kmem_cache_destroy(prot->rsk_prot->slab);
2308		kfree(prot->rsk_prot->slab_name);
2309		prot->rsk_prot->slab = NULL;
2310	}
2311
2312	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2313		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2314		kfree(prot->twsk_prot->twsk_slab_name);
2315		prot->twsk_prot->twsk_slab = NULL;
2316	}
2317}
2318EXPORT_SYMBOL(proto_unregister);
2319
2320#ifdef CONFIG_PROC_FS
2321static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2322	__acquires(proto_list_lock)
2323{
2324	read_lock(&proto_list_lock);
2325	return seq_list_start_head(&proto_list, *pos);
2326}
2327
2328static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2329{
2330	return seq_list_next(v, &proto_list, pos);
2331}
2332
2333static void proto_seq_stop(struct seq_file *seq, void *v)
2334	__releases(proto_list_lock)
2335{
2336	read_unlock(&proto_list_lock);
2337}
2338
2339static char proto_method_implemented(const void *method)
2340{
2341	return method == NULL ? 'n' : 'y';
2342}
2343
2344static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2345{
2346	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
2347			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2348		   proto->name,
2349		   proto->obj_size,
2350		   sock_prot_inuse_get(seq_file_net(seq), proto),
2351		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
2352		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2353		   proto->max_header,
2354		   proto->slab == NULL ? "no" : "yes",
2355		   module_name(proto->owner),
2356		   proto_method_implemented(proto->close),
2357		   proto_method_implemented(proto->connect),
2358		   proto_method_implemented(proto->disconnect),
2359		   proto_method_implemented(proto->accept),
2360		   proto_method_implemented(proto->ioctl),
2361		   proto_method_implemented(proto->init),
2362		   proto_method_implemented(proto->destroy),
2363		   proto_method_implemented(proto->shutdown),
2364		   proto_method_implemented(proto->setsockopt),
2365		   proto_method_implemented(proto->getsockopt),
2366		   proto_method_implemented(proto->sendmsg),
2367		   proto_method_implemented(proto->recvmsg),
2368		   proto_method_implemented(proto->sendpage),
2369		   proto_method_implemented(proto->bind),
2370		   proto_method_implemented(proto->backlog_rcv),
2371		   proto_method_implemented(proto->hash),
2372		   proto_method_implemented(proto->unhash),
2373		   proto_method_implemented(proto->get_port),
2374		   proto_method_implemented(proto->enter_memory_pressure));
2375}
2376
2377static int proto_seq_show(struct seq_file *seq, void *v)
2378{
2379	if (v == &proto_list)
2380		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2381			   "protocol",
2382			   "size",
2383			   "sockets",
2384			   "memory",
2385			   "press",
2386			   "maxhdr",
2387			   "slab",
2388			   "module",
2389			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2390	else
2391		proto_seq_printf(seq, list_entry(v, struct proto, node));
2392	return 0;
2393}
2394
2395static const struct seq_operations proto_seq_ops = {
2396	.start  = proto_seq_start,
2397	.next   = proto_seq_next,
2398	.stop   = proto_seq_stop,
2399	.show   = proto_seq_show,
2400};
2401
2402static int proto_seq_open(struct inode *inode, struct file *file)
2403{
2404	return seq_open_net(inode, file, &proto_seq_ops,
2405			    sizeof(struct seq_net_private));
2406}
2407
2408static const struct file_operations proto_seq_fops = {
2409	.owner		= THIS_MODULE,
2410	.open		= proto_seq_open,
2411	.read		= seq_read,
2412	.llseek		= seq_lseek,
2413	.release	= seq_release_net,
2414};
2415
2416static __net_init int proto_init_net(struct net *net)
2417{
2418	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2419		return -ENOMEM;
2420
2421	return 0;
2422}
2423
2424static __net_exit void proto_exit_net(struct net *net)
2425{
2426	proc_net_remove(net, "protocols");
2427}
2428
2429
2430static __net_initdata struct pernet_operations proto_net_ops = {
2431	.init = proto_init_net,
2432	.exit = proto_exit_net,
2433};
2434
2435static int __init proto_init(void)
2436{
2437	return register_pernet_subsys(&proto_net_ops);
2438}
2439
2440subsys_initcall(proto_init);
2441
2442#endif /* PROC_FS */
2443