sock.c revision faf234220fb79a05891477a75180e1d9f7ab4105
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	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(sk->sk_filter);
1077	if (filter) {
1078		sk_filter_uncharge(sk, filter);
1079		rcu_assign_pointer(sk->sk_filter, NULL);
1080	}
1081
1082	sock_disable_timestamp(sk, SOCK_TIMESTAMP);
1083	sock_disable_timestamp(sk, SOCK_TIMESTAMPING_RX_SOFTWARE);
1084
1085	if (atomic_read(&sk->sk_omem_alloc))
1086		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
1087		       __func__, atomic_read(&sk->sk_omem_alloc));
1088
1089	put_net(sock_net(sk));
1090	sk_prot_free(sk->sk_prot_creator, sk);
1091}
1092
1093void sk_free(struct sock *sk)
1094{
1095	/*
1096	 * We substract one from sk_wmem_alloc and can know if
1097	 * some packets are still in some tx queue.
1098	 * If not null, sock_wfree() will call __sk_free(sk) later
1099	 */
1100	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
1101		__sk_free(sk);
1102}
1103EXPORT_SYMBOL(sk_free);
1104
1105/*
1106 * Last sock_put should drop referrence to sk->sk_net. It has already
1107 * been dropped in sk_change_net. Taking referrence to stopping namespace
1108 * is not an option.
1109 * Take referrence to a socket to remove it from hash _alive_ and after that
1110 * destroy it in the context of init_net.
1111 */
1112void sk_release_kernel(struct sock *sk)
1113{
1114	if (sk == NULL || sk->sk_socket == NULL)
1115		return;
1116
1117	sock_hold(sk);
1118	sock_release(sk->sk_socket);
1119	release_net(sock_net(sk));
1120	sock_net_set(sk, get_net(&init_net));
1121	sock_put(sk);
1122}
1123EXPORT_SYMBOL(sk_release_kernel);
1124
1125struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
1126{
1127	struct sock *newsk;
1128
1129	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
1130	if (newsk != NULL) {
1131		struct sk_filter *filter;
1132
1133		sock_copy(newsk, sk);
1134
1135		/* SANITY */
1136		get_net(sock_net(newsk));
1137		sk_node_init(&newsk->sk_node);
1138		sock_lock_init(newsk);
1139		bh_lock_sock(newsk);
1140		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
1141
1142		atomic_set(&newsk->sk_rmem_alloc, 0);
1143		/*
1144		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
1145		 */
1146		atomic_set(&newsk->sk_wmem_alloc, 1);
1147		atomic_set(&newsk->sk_omem_alloc, 0);
1148		skb_queue_head_init(&newsk->sk_receive_queue);
1149		skb_queue_head_init(&newsk->sk_write_queue);
1150#ifdef CONFIG_NET_DMA
1151		skb_queue_head_init(&newsk->sk_async_wait_queue);
1152#endif
1153
1154		rwlock_init(&newsk->sk_dst_lock);
1155		rwlock_init(&newsk->sk_callback_lock);
1156		lockdep_set_class_and_name(&newsk->sk_callback_lock,
1157				af_callback_keys + newsk->sk_family,
1158				af_family_clock_key_strings[newsk->sk_family]);
1159
1160		newsk->sk_dst_cache	= NULL;
1161		newsk->sk_wmem_queued	= 0;
1162		newsk->sk_forward_alloc = 0;
1163		newsk->sk_send_head	= NULL;
1164		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
1165
1166		sock_reset_flag(newsk, SOCK_DONE);
1167		skb_queue_head_init(&newsk->sk_error_queue);
1168
1169		filter = newsk->sk_filter;
1170		if (filter != NULL)
1171			sk_filter_charge(newsk, filter);
1172
1173		if (unlikely(xfrm_sk_clone_policy(newsk))) {
1174			/* It is still raw copy of parent, so invalidate
1175			 * destructor and make plain sk_free() */
1176			newsk->sk_destruct = NULL;
1177			sk_free(newsk);
1178			newsk = NULL;
1179			goto out;
1180		}
1181
1182		newsk->sk_err	   = 0;
1183		newsk->sk_priority = 0;
1184		/*
1185		 * Before updating sk_refcnt, we must commit prior changes to memory
1186		 * (Documentation/RCU/rculist_nulls.txt for details)
1187		 */
1188		smp_wmb();
1189		atomic_set(&newsk->sk_refcnt, 2);
1190
1191		/*
1192		 * Increment the counter in the same struct proto as the master
1193		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
1194		 * is the same as sk->sk_prot->socks, as this field was copied
1195		 * with memcpy).
1196		 *
1197		 * This _changes_ the previous behaviour, where
1198		 * tcp_create_openreq_child always was incrementing the
1199		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
1200		 * to be taken into account in all callers. -acme
1201		 */
1202		sk_refcnt_debug_inc(newsk);
1203		sk_set_socket(newsk, NULL);
1204		newsk->sk_sleep	 = NULL;
1205
1206		if (newsk->sk_prot->sockets_allocated)
1207			percpu_counter_inc(newsk->sk_prot->sockets_allocated);
1208
1209		if (sock_flag(newsk, SOCK_TIMESTAMP) ||
1210		    sock_flag(newsk, SOCK_TIMESTAMPING_RX_SOFTWARE))
1211			net_enable_timestamp();
1212	}
1213out:
1214	return newsk;
1215}
1216EXPORT_SYMBOL_GPL(sk_clone);
1217
1218void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
1219{
1220	__sk_dst_set(sk, dst);
1221	sk->sk_route_caps = dst->dev->features;
1222	if (sk->sk_route_caps & NETIF_F_GSO)
1223		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
1224	if (sk_can_gso(sk)) {
1225		if (dst->header_len) {
1226			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
1227		} else {
1228			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
1229			sk->sk_gso_max_size = dst->dev->gso_max_size;
1230		}
1231	}
1232}
1233EXPORT_SYMBOL_GPL(sk_setup_caps);
1234
1235void __init sk_init(void)
1236{
1237	if (totalram_pages <= 4096) {
1238		sysctl_wmem_max = 32767;
1239		sysctl_rmem_max = 32767;
1240		sysctl_wmem_default = 32767;
1241		sysctl_rmem_default = 32767;
1242	} else if (totalram_pages >= 131072) {
1243		sysctl_wmem_max = 131071;
1244		sysctl_rmem_max = 131071;
1245	}
1246}
1247
1248/*
1249 *	Simple resource managers for sockets.
1250 */
1251
1252
1253/*
1254 * Write buffer destructor automatically called from kfree_skb.
1255 */
1256void sock_wfree(struct sk_buff *skb)
1257{
1258	struct sock *sk = skb->sk;
1259	unsigned int len = skb->truesize;
1260
1261	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
1262		/*
1263		 * Keep a reference on sk_wmem_alloc, this will be released
1264		 * after sk_write_space() call
1265		 */
1266		atomic_sub(len - 1, &sk->sk_wmem_alloc);
1267		sk->sk_write_space(sk);
1268		len = 1;
1269	}
1270	/*
1271	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
1272	 * could not do because of in-flight packets
1273	 */
1274	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
1275		__sk_free(sk);
1276}
1277EXPORT_SYMBOL(sock_wfree);
1278
1279/*
1280 * Read buffer destructor automatically called from kfree_skb.
1281 */
1282void sock_rfree(struct sk_buff *skb)
1283{
1284	struct sock *sk = skb->sk;
1285
1286	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
1287	sk_mem_uncharge(skb->sk, skb->truesize);
1288}
1289EXPORT_SYMBOL(sock_rfree);
1290
1291
1292int sock_i_uid(struct sock *sk)
1293{
1294	int uid;
1295
1296	read_lock(&sk->sk_callback_lock);
1297	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
1298	read_unlock(&sk->sk_callback_lock);
1299	return uid;
1300}
1301EXPORT_SYMBOL(sock_i_uid);
1302
1303unsigned long sock_i_ino(struct sock *sk)
1304{
1305	unsigned long ino;
1306
1307	read_lock(&sk->sk_callback_lock);
1308	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
1309	read_unlock(&sk->sk_callback_lock);
1310	return ino;
1311}
1312EXPORT_SYMBOL(sock_i_ino);
1313
1314/*
1315 * Allocate a skb from the socket's send buffer.
1316 */
1317struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
1318			     gfp_t priority)
1319{
1320	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1321		struct sk_buff *skb = alloc_skb(size, priority);
1322		if (skb) {
1323			skb_set_owner_w(skb, sk);
1324			return skb;
1325		}
1326	}
1327	return NULL;
1328}
1329EXPORT_SYMBOL(sock_wmalloc);
1330
1331/*
1332 * Allocate a skb from the socket's receive buffer.
1333 */
1334struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
1335			     gfp_t priority)
1336{
1337	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
1338		struct sk_buff *skb = alloc_skb(size, priority);
1339		if (skb) {
1340			skb_set_owner_r(skb, sk);
1341			return skb;
1342		}
1343	}
1344	return NULL;
1345}
1346
1347/*
1348 * Allocate a memory block from the socket's option memory buffer.
1349 */
1350void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
1351{
1352	if ((unsigned)size <= sysctl_optmem_max &&
1353	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
1354		void *mem;
1355		/* First do the add, to avoid the race if kmalloc
1356		 * might sleep.
1357		 */
1358		atomic_add(size, &sk->sk_omem_alloc);
1359		mem = kmalloc(size, priority);
1360		if (mem)
1361			return mem;
1362		atomic_sub(size, &sk->sk_omem_alloc);
1363	}
1364	return NULL;
1365}
1366EXPORT_SYMBOL(sock_kmalloc);
1367
1368/*
1369 * Free an option memory block.
1370 */
1371void sock_kfree_s(struct sock *sk, void *mem, int size)
1372{
1373	kfree(mem);
1374	atomic_sub(size, &sk->sk_omem_alloc);
1375}
1376EXPORT_SYMBOL(sock_kfree_s);
1377
1378/* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
1379   I think, these locks should be removed for datagram sockets.
1380 */
1381static long sock_wait_for_wmem(struct sock *sk, long timeo)
1382{
1383	DEFINE_WAIT(wait);
1384
1385	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1386	for (;;) {
1387		if (!timeo)
1388			break;
1389		if (signal_pending(current))
1390			break;
1391		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1392		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1393		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
1394			break;
1395		if (sk->sk_shutdown & SEND_SHUTDOWN)
1396			break;
1397		if (sk->sk_err)
1398			break;
1399		timeo = schedule_timeout(timeo);
1400	}
1401	finish_wait(sk->sk_sleep, &wait);
1402	return timeo;
1403}
1404
1405
1406/*
1407 *	Generic send/receive buffer handlers
1408 */
1409
1410struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
1411				     unsigned long data_len, int noblock,
1412				     int *errcode)
1413{
1414	struct sk_buff *skb;
1415	gfp_t gfp_mask;
1416	long timeo;
1417	int err;
1418
1419	gfp_mask = sk->sk_allocation;
1420	if (gfp_mask & __GFP_WAIT)
1421		gfp_mask |= __GFP_REPEAT;
1422
1423	timeo = sock_sndtimeo(sk, noblock);
1424	while (1) {
1425		err = sock_error(sk);
1426		if (err != 0)
1427			goto failure;
1428
1429		err = -EPIPE;
1430		if (sk->sk_shutdown & SEND_SHUTDOWN)
1431			goto failure;
1432
1433		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
1434			skb = alloc_skb(header_len, gfp_mask);
1435			if (skb) {
1436				int npages;
1437				int i;
1438
1439				/* No pages, we're done... */
1440				if (!data_len)
1441					break;
1442
1443				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
1444				skb->truesize += data_len;
1445				skb_shinfo(skb)->nr_frags = npages;
1446				for (i = 0; i < npages; i++) {
1447					struct page *page;
1448					skb_frag_t *frag;
1449
1450					page = alloc_pages(sk->sk_allocation, 0);
1451					if (!page) {
1452						err = -ENOBUFS;
1453						skb_shinfo(skb)->nr_frags = i;
1454						kfree_skb(skb);
1455						goto failure;
1456					}
1457
1458					frag = &skb_shinfo(skb)->frags[i];
1459					frag->page = page;
1460					frag->page_offset = 0;
1461					frag->size = (data_len >= PAGE_SIZE ?
1462						      PAGE_SIZE :
1463						      data_len);
1464					data_len -= PAGE_SIZE;
1465				}
1466
1467				/* Full success... */
1468				break;
1469			}
1470			err = -ENOBUFS;
1471			goto failure;
1472		}
1473		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1474		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1475		err = -EAGAIN;
1476		if (!timeo)
1477			goto failure;
1478		if (signal_pending(current))
1479			goto interrupted;
1480		timeo = sock_wait_for_wmem(sk, timeo);
1481	}
1482
1483	skb_set_owner_w(skb, sk);
1484	return skb;
1485
1486interrupted:
1487	err = sock_intr_errno(timeo);
1488failure:
1489	*errcode = err;
1490	return NULL;
1491}
1492EXPORT_SYMBOL(sock_alloc_send_pskb);
1493
1494struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1495				    int noblock, int *errcode)
1496{
1497	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1498}
1499EXPORT_SYMBOL(sock_alloc_send_skb);
1500
1501static void __lock_sock(struct sock *sk)
1502{
1503	DEFINE_WAIT(wait);
1504
1505	for (;;) {
1506		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1507					TASK_UNINTERRUPTIBLE);
1508		spin_unlock_bh(&sk->sk_lock.slock);
1509		schedule();
1510		spin_lock_bh(&sk->sk_lock.slock);
1511		if (!sock_owned_by_user(sk))
1512			break;
1513	}
1514	finish_wait(&sk->sk_lock.wq, &wait);
1515}
1516
1517static void __release_sock(struct sock *sk)
1518{
1519	struct sk_buff *skb = sk->sk_backlog.head;
1520
1521	do {
1522		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1523		bh_unlock_sock(sk);
1524
1525		do {
1526			struct sk_buff *next = skb->next;
1527
1528			skb->next = NULL;
1529			sk_backlog_rcv(sk, skb);
1530
1531			/*
1532			 * We are in process context here with softirqs
1533			 * disabled, use cond_resched_softirq() to preempt.
1534			 * This is safe to do because we've taken the backlog
1535			 * queue private:
1536			 */
1537			cond_resched_softirq();
1538
1539			skb = next;
1540		} while (skb != NULL);
1541
1542		bh_lock_sock(sk);
1543	} while ((skb = sk->sk_backlog.head) != NULL);
1544}
1545
1546/**
1547 * sk_wait_data - wait for data to arrive at sk_receive_queue
1548 * @sk:    sock to wait on
1549 * @timeo: for how long
1550 *
1551 * Now socket state including sk->sk_err is changed only under lock,
1552 * hence we may omit checks after joining wait queue.
1553 * We check receive queue before schedule() only as optimization;
1554 * it is very likely that release_sock() added new data.
1555 */
1556int sk_wait_data(struct sock *sk, long *timeo)
1557{
1558	int rc;
1559	DEFINE_WAIT(wait);
1560
1561	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1562	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1563	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1564	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1565	finish_wait(sk->sk_sleep, &wait);
1566	return rc;
1567}
1568EXPORT_SYMBOL(sk_wait_data);
1569
1570/**
1571 *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
1572 *	@sk: socket
1573 *	@size: memory size to allocate
1574 *	@kind: allocation type
1575 *
1576 *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
1577 *	rmem allocation. This function assumes that protocols which have
1578 *	memory_pressure use sk_wmem_queued as write buffer accounting.
1579 */
1580int __sk_mem_schedule(struct sock *sk, int size, int kind)
1581{
1582	struct proto *prot = sk->sk_prot;
1583	int amt = sk_mem_pages(size);
1584	int allocated;
1585
1586	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
1587	allocated = atomic_add_return(amt, prot->memory_allocated);
1588
1589	/* Under limit. */
1590	if (allocated <= prot->sysctl_mem[0]) {
1591		if (prot->memory_pressure && *prot->memory_pressure)
1592			*prot->memory_pressure = 0;
1593		return 1;
1594	}
1595
1596	/* Under pressure. */
1597	if (allocated > prot->sysctl_mem[1])
1598		if (prot->enter_memory_pressure)
1599			prot->enter_memory_pressure(sk);
1600
1601	/* Over hard limit. */
1602	if (allocated > prot->sysctl_mem[2])
1603		goto suppress_allocation;
1604
1605	/* guarantee minimum buffer size under pressure */
1606	if (kind == SK_MEM_RECV) {
1607		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
1608			return 1;
1609	} else { /* SK_MEM_SEND */
1610		if (sk->sk_type == SOCK_STREAM) {
1611			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
1612				return 1;
1613		} else if (atomic_read(&sk->sk_wmem_alloc) <
1614			   prot->sysctl_wmem[0])
1615				return 1;
1616	}
1617
1618	if (prot->memory_pressure) {
1619		int alloc;
1620
1621		if (!*prot->memory_pressure)
1622			return 1;
1623		alloc = percpu_counter_read_positive(prot->sockets_allocated);
1624		if (prot->sysctl_mem[2] > alloc *
1625		    sk_mem_pages(sk->sk_wmem_queued +
1626				 atomic_read(&sk->sk_rmem_alloc) +
1627				 sk->sk_forward_alloc))
1628			return 1;
1629	}
1630
1631suppress_allocation:
1632
1633	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
1634		sk_stream_moderate_sndbuf(sk);
1635
1636		/* Fail only if socket is _under_ its sndbuf.
1637		 * In this case we cannot block, so that we have to fail.
1638		 */
1639		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
1640			return 1;
1641	}
1642
1643	/* Alas. Undo changes. */
1644	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
1645	atomic_sub(amt, prot->memory_allocated);
1646	return 0;
1647}
1648EXPORT_SYMBOL(__sk_mem_schedule);
1649
1650/**
1651 *	__sk_reclaim - reclaim memory_allocated
1652 *	@sk: socket
1653 */
1654void __sk_mem_reclaim(struct sock *sk)
1655{
1656	struct proto *prot = sk->sk_prot;
1657
1658	atomic_sub(sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT,
1659		   prot->memory_allocated);
1660	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
1661
1662	if (prot->memory_pressure && *prot->memory_pressure &&
1663	    (atomic_read(prot->memory_allocated) < prot->sysctl_mem[0]))
1664		*prot->memory_pressure = 0;
1665}
1666EXPORT_SYMBOL(__sk_mem_reclaim);
1667
1668
1669/*
1670 * Set of default routines for initialising struct proto_ops when
1671 * the protocol does not support a particular function. In certain
1672 * cases where it makes no sense for a protocol to have a "do nothing"
1673 * function, some default processing is provided.
1674 */
1675
1676int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1677{
1678	return -EOPNOTSUPP;
1679}
1680EXPORT_SYMBOL(sock_no_bind);
1681
1682int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1683		    int len, int flags)
1684{
1685	return -EOPNOTSUPP;
1686}
1687EXPORT_SYMBOL(sock_no_connect);
1688
1689int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1690{
1691	return -EOPNOTSUPP;
1692}
1693EXPORT_SYMBOL(sock_no_socketpair);
1694
1695int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1696{
1697	return -EOPNOTSUPP;
1698}
1699EXPORT_SYMBOL(sock_no_accept);
1700
1701int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1702		    int *len, int peer)
1703{
1704	return -EOPNOTSUPP;
1705}
1706EXPORT_SYMBOL(sock_no_getname);
1707
1708unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
1709{
1710	return 0;
1711}
1712EXPORT_SYMBOL(sock_no_poll);
1713
1714int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1715{
1716	return -EOPNOTSUPP;
1717}
1718EXPORT_SYMBOL(sock_no_ioctl);
1719
1720int sock_no_listen(struct socket *sock, int backlog)
1721{
1722	return -EOPNOTSUPP;
1723}
1724EXPORT_SYMBOL(sock_no_listen);
1725
1726int sock_no_shutdown(struct socket *sock, int how)
1727{
1728	return -EOPNOTSUPP;
1729}
1730EXPORT_SYMBOL(sock_no_shutdown);
1731
1732int sock_no_setsockopt(struct socket *sock, int level, int optname,
1733		    char __user *optval, unsigned int optlen)
1734{
1735	return -EOPNOTSUPP;
1736}
1737EXPORT_SYMBOL(sock_no_setsockopt);
1738
1739int sock_no_getsockopt(struct socket *sock, int level, int optname,
1740		    char __user *optval, int __user *optlen)
1741{
1742	return -EOPNOTSUPP;
1743}
1744EXPORT_SYMBOL(sock_no_getsockopt);
1745
1746int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1747		    size_t len)
1748{
1749	return -EOPNOTSUPP;
1750}
1751EXPORT_SYMBOL(sock_no_sendmsg);
1752
1753int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1754		    size_t len, int flags)
1755{
1756	return -EOPNOTSUPP;
1757}
1758EXPORT_SYMBOL(sock_no_recvmsg);
1759
1760int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1761{
1762	/* Mirror missing mmap method error code */
1763	return -ENODEV;
1764}
1765EXPORT_SYMBOL(sock_no_mmap);
1766
1767ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1768{
1769	ssize_t res;
1770	struct msghdr msg = {.msg_flags = flags};
1771	struct kvec iov;
1772	char *kaddr = kmap(page);
1773	iov.iov_base = kaddr + offset;
1774	iov.iov_len = size;
1775	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1776	kunmap(page);
1777	return res;
1778}
1779EXPORT_SYMBOL(sock_no_sendpage);
1780
1781/*
1782 *	Default Socket Callbacks
1783 */
1784
1785static void sock_def_wakeup(struct sock *sk)
1786{
1787	read_lock(&sk->sk_callback_lock);
1788	if (sk_has_sleeper(sk))
1789		wake_up_interruptible_all(sk->sk_sleep);
1790	read_unlock(&sk->sk_callback_lock);
1791}
1792
1793static void sock_def_error_report(struct sock *sk)
1794{
1795	read_lock(&sk->sk_callback_lock);
1796	if (sk_has_sleeper(sk))
1797		wake_up_interruptible_poll(sk->sk_sleep, POLLERR);
1798	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
1799	read_unlock(&sk->sk_callback_lock);
1800}
1801
1802static void sock_def_readable(struct sock *sk, int len)
1803{
1804	read_lock(&sk->sk_callback_lock);
1805	if (sk_has_sleeper(sk))
1806		wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN |
1807						POLLRDNORM | POLLRDBAND);
1808	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
1809	read_unlock(&sk->sk_callback_lock);
1810}
1811
1812static void sock_def_write_space(struct sock *sk)
1813{
1814	read_lock(&sk->sk_callback_lock);
1815
1816	/* Do not wake up a writer until he can make "significant"
1817	 * progress.  --DaveM
1818	 */
1819	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1820		if (sk_has_sleeper(sk))
1821			wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
1822						POLLWRNORM | POLLWRBAND);
1823
1824		/* Should agree with poll, otherwise some programs break */
1825		if (sock_writeable(sk))
1826			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
1827	}
1828
1829	read_unlock(&sk->sk_callback_lock);
1830}
1831
1832static void sock_def_destruct(struct sock *sk)
1833{
1834	kfree(sk->sk_protinfo);
1835}
1836
1837void sk_send_sigurg(struct sock *sk)
1838{
1839	if (sk->sk_socket && sk->sk_socket->file)
1840		if (send_sigurg(&sk->sk_socket->file->f_owner))
1841			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
1842}
1843EXPORT_SYMBOL(sk_send_sigurg);
1844
1845void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1846		    unsigned long expires)
1847{
1848	if (!mod_timer(timer, expires))
1849		sock_hold(sk);
1850}
1851EXPORT_SYMBOL(sk_reset_timer);
1852
1853void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1854{
1855	if (timer_pending(timer) && del_timer(timer))
1856		__sock_put(sk);
1857}
1858EXPORT_SYMBOL(sk_stop_timer);
1859
1860void sock_init_data(struct socket *sock, struct sock *sk)
1861{
1862	skb_queue_head_init(&sk->sk_receive_queue);
1863	skb_queue_head_init(&sk->sk_write_queue);
1864	skb_queue_head_init(&sk->sk_error_queue);
1865#ifdef CONFIG_NET_DMA
1866	skb_queue_head_init(&sk->sk_async_wait_queue);
1867#endif
1868
1869	sk->sk_send_head	=	NULL;
1870
1871	init_timer(&sk->sk_timer);
1872
1873	sk->sk_allocation	=	GFP_KERNEL;
1874	sk->sk_rcvbuf		=	sysctl_rmem_default;
1875	sk->sk_sndbuf		=	sysctl_wmem_default;
1876	sk->sk_state		=	TCP_CLOSE;
1877	sk_set_socket(sk, sock);
1878
1879	sock_set_flag(sk, SOCK_ZAPPED);
1880
1881	if (sock) {
1882		sk->sk_type	=	sock->type;
1883		sk->sk_sleep	=	&sock->wait;
1884		sock->sk	=	sk;
1885	} else
1886		sk->sk_sleep	=	NULL;
1887
1888	rwlock_init(&sk->sk_dst_lock);
1889	rwlock_init(&sk->sk_callback_lock);
1890	lockdep_set_class_and_name(&sk->sk_callback_lock,
1891			af_callback_keys + sk->sk_family,
1892			af_family_clock_key_strings[sk->sk_family]);
1893
1894	sk->sk_state_change	=	sock_def_wakeup;
1895	sk->sk_data_ready	=	sock_def_readable;
1896	sk->sk_write_space	=	sock_def_write_space;
1897	sk->sk_error_report	=	sock_def_error_report;
1898	sk->sk_destruct		=	sock_def_destruct;
1899
1900	sk->sk_sndmsg_page	=	NULL;
1901	sk->sk_sndmsg_off	=	0;
1902
1903	sk->sk_peercred.pid 	=	0;
1904	sk->sk_peercred.uid	=	-1;
1905	sk->sk_peercred.gid	=	-1;
1906	sk->sk_write_pending	=	0;
1907	sk->sk_rcvlowat		=	1;
1908	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1909	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1910
1911	sk->sk_stamp = ktime_set(-1L, 0);
1912
1913	/*
1914	 * Before updating sk_refcnt, we must commit prior changes to memory
1915	 * (Documentation/RCU/rculist_nulls.txt for details)
1916	 */
1917	smp_wmb();
1918	atomic_set(&sk->sk_refcnt, 1);
1919	atomic_set(&sk->sk_drops, 0);
1920}
1921EXPORT_SYMBOL(sock_init_data);
1922
1923void lock_sock_nested(struct sock *sk, int subclass)
1924{
1925	might_sleep();
1926	spin_lock_bh(&sk->sk_lock.slock);
1927	if (sk->sk_lock.owned)
1928		__lock_sock(sk);
1929	sk->sk_lock.owned = 1;
1930	spin_unlock(&sk->sk_lock.slock);
1931	/*
1932	 * The sk_lock has mutex_lock() semantics here:
1933	 */
1934	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
1935	local_bh_enable();
1936}
1937EXPORT_SYMBOL(lock_sock_nested);
1938
1939void release_sock(struct sock *sk)
1940{
1941	/*
1942	 * The sk_lock has mutex_unlock() semantics:
1943	 */
1944	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
1945
1946	spin_lock_bh(&sk->sk_lock.slock);
1947	if (sk->sk_backlog.tail)
1948		__release_sock(sk);
1949	sk->sk_lock.owned = 0;
1950	if (waitqueue_active(&sk->sk_lock.wq))
1951		wake_up(&sk->sk_lock.wq);
1952	spin_unlock_bh(&sk->sk_lock.slock);
1953}
1954EXPORT_SYMBOL(release_sock);
1955
1956int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1957{
1958	struct timeval tv;
1959	if (!sock_flag(sk, SOCK_TIMESTAMP))
1960		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1961	tv = ktime_to_timeval(sk->sk_stamp);
1962	if (tv.tv_sec == -1)
1963		return -ENOENT;
1964	if (tv.tv_sec == 0) {
1965		sk->sk_stamp = ktime_get_real();
1966		tv = ktime_to_timeval(sk->sk_stamp);
1967	}
1968	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
1969}
1970EXPORT_SYMBOL(sock_get_timestamp);
1971
1972int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
1973{
1974	struct timespec ts;
1975	if (!sock_flag(sk, SOCK_TIMESTAMP))
1976		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
1977	ts = ktime_to_timespec(sk->sk_stamp);
1978	if (ts.tv_sec == -1)
1979		return -ENOENT;
1980	if (ts.tv_sec == 0) {
1981		sk->sk_stamp = ktime_get_real();
1982		ts = ktime_to_timespec(sk->sk_stamp);
1983	}
1984	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
1985}
1986EXPORT_SYMBOL(sock_get_timestampns);
1987
1988void sock_enable_timestamp(struct sock *sk, int flag)
1989{
1990	if (!sock_flag(sk, flag)) {
1991		sock_set_flag(sk, flag);
1992		/*
1993		 * we just set one of the two flags which require net
1994		 * time stamping, but time stamping might have been on
1995		 * already because of the other one
1996		 */
1997		if (!sock_flag(sk,
1998				flag == SOCK_TIMESTAMP ?
1999				SOCK_TIMESTAMPING_RX_SOFTWARE :
2000				SOCK_TIMESTAMP))
2001			net_enable_timestamp();
2002	}
2003}
2004
2005/*
2006 *	Get a socket option on an socket.
2007 *
2008 *	FIX: POSIX 1003.1g is very ambiguous here. It states that
2009 *	asynchronous errors should be reported by getsockopt. We assume
2010 *	this means if you specify SO_ERROR (otherwise whats the point of it).
2011 */
2012int sock_common_getsockopt(struct socket *sock, int level, int optname,
2013			   char __user *optval, int __user *optlen)
2014{
2015	struct sock *sk = sock->sk;
2016
2017	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2018}
2019EXPORT_SYMBOL(sock_common_getsockopt);
2020
2021#ifdef CONFIG_COMPAT
2022int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
2023				  char __user *optval, int __user *optlen)
2024{
2025	struct sock *sk = sock->sk;
2026
2027	if (sk->sk_prot->compat_getsockopt != NULL)
2028		return sk->sk_prot->compat_getsockopt(sk, level, optname,
2029						      optval, optlen);
2030	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
2031}
2032EXPORT_SYMBOL(compat_sock_common_getsockopt);
2033#endif
2034
2035int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
2036			struct msghdr *msg, size_t size, int flags)
2037{
2038	struct sock *sk = sock->sk;
2039	int addr_len = 0;
2040	int err;
2041
2042	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
2043				   flags & ~MSG_DONTWAIT, &addr_len);
2044	if (err >= 0)
2045		msg->msg_namelen = addr_len;
2046	return err;
2047}
2048EXPORT_SYMBOL(sock_common_recvmsg);
2049
2050/*
2051 *	Set socket options on an inet socket.
2052 */
2053int sock_common_setsockopt(struct socket *sock, int level, int optname,
2054			   char __user *optval, unsigned int optlen)
2055{
2056	struct sock *sk = sock->sk;
2057
2058	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2059}
2060EXPORT_SYMBOL(sock_common_setsockopt);
2061
2062#ifdef CONFIG_COMPAT
2063int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
2064				  char __user *optval, unsigned int optlen)
2065{
2066	struct sock *sk = sock->sk;
2067
2068	if (sk->sk_prot->compat_setsockopt != NULL)
2069		return sk->sk_prot->compat_setsockopt(sk, level, optname,
2070						      optval, optlen);
2071	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
2072}
2073EXPORT_SYMBOL(compat_sock_common_setsockopt);
2074#endif
2075
2076void sk_common_release(struct sock *sk)
2077{
2078	if (sk->sk_prot->destroy)
2079		sk->sk_prot->destroy(sk);
2080
2081	/*
2082	 * Observation: when sock_common_release is called, processes have
2083	 * no access to socket. But net still has.
2084	 * Step one, detach it from networking:
2085	 *
2086	 * A. Remove from hash tables.
2087	 */
2088
2089	sk->sk_prot->unhash(sk);
2090
2091	/*
2092	 * In this point socket cannot receive new packets, but it is possible
2093	 * that some packets are in flight because some CPU runs receiver and
2094	 * did hash table lookup before we unhashed socket. They will achieve
2095	 * receive queue and will be purged by socket destructor.
2096	 *
2097	 * Also we still have packets pending on receive queue and probably,
2098	 * our own packets waiting in device queues. sock_destroy will drain
2099	 * receive queue, but transmitted packets will delay socket destruction
2100	 * until the last reference will be released.
2101	 */
2102
2103	sock_orphan(sk);
2104
2105	xfrm_sk_free_policy(sk);
2106
2107	sk_refcnt_debug_release(sk);
2108	sock_put(sk);
2109}
2110EXPORT_SYMBOL(sk_common_release);
2111
2112static DEFINE_RWLOCK(proto_list_lock);
2113static LIST_HEAD(proto_list);
2114
2115#ifdef CONFIG_PROC_FS
2116#define PROTO_INUSE_NR	64	/* should be enough for the first time */
2117struct prot_inuse {
2118	int val[PROTO_INUSE_NR];
2119};
2120
2121static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
2122
2123#ifdef CONFIG_NET_NS
2124void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2125{
2126	int cpu = smp_processor_id();
2127	per_cpu_ptr(net->core.inuse, cpu)->val[prot->inuse_idx] += val;
2128}
2129EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2130
2131int sock_prot_inuse_get(struct net *net, struct proto *prot)
2132{
2133	int cpu, idx = prot->inuse_idx;
2134	int res = 0;
2135
2136	for_each_possible_cpu(cpu)
2137		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
2138
2139	return res >= 0 ? res : 0;
2140}
2141EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2142
2143static int __net_init sock_inuse_init_net(struct net *net)
2144{
2145	net->core.inuse = alloc_percpu(struct prot_inuse);
2146	return net->core.inuse ? 0 : -ENOMEM;
2147}
2148
2149static void __net_exit sock_inuse_exit_net(struct net *net)
2150{
2151	free_percpu(net->core.inuse);
2152}
2153
2154static struct pernet_operations net_inuse_ops = {
2155	.init = sock_inuse_init_net,
2156	.exit = sock_inuse_exit_net,
2157};
2158
2159static __init int net_inuse_init(void)
2160{
2161	if (register_pernet_subsys(&net_inuse_ops))
2162		panic("Cannot initialize net inuse counters");
2163
2164	return 0;
2165}
2166
2167core_initcall(net_inuse_init);
2168#else
2169static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
2170
2171void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
2172{
2173	__get_cpu_var(prot_inuse).val[prot->inuse_idx] += val;
2174}
2175EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
2176
2177int sock_prot_inuse_get(struct net *net, struct proto *prot)
2178{
2179	int cpu, idx = prot->inuse_idx;
2180	int res = 0;
2181
2182	for_each_possible_cpu(cpu)
2183		res += per_cpu(prot_inuse, cpu).val[idx];
2184
2185	return res >= 0 ? res : 0;
2186}
2187EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
2188#endif
2189
2190static void assign_proto_idx(struct proto *prot)
2191{
2192	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
2193
2194	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
2195		printk(KERN_ERR "PROTO_INUSE_NR exhausted\n");
2196		return;
2197	}
2198
2199	set_bit(prot->inuse_idx, proto_inuse_idx);
2200}
2201
2202static void release_proto_idx(struct proto *prot)
2203{
2204	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
2205		clear_bit(prot->inuse_idx, proto_inuse_idx);
2206}
2207#else
2208static inline void assign_proto_idx(struct proto *prot)
2209{
2210}
2211
2212static inline void release_proto_idx(struct proto *prot)
2213{
2214}
2215#endif
2216
2217int proto_register(struct proto *prot, int alloc_slab)
2218{
2219	if (alloc_slab) {
2220		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
2221					SLAB_HWCACHE_ALIGN | prot->slab_flags,
2222					NULL);
2223
2224		if (prot->slab == NULL) {
2225			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
2226			       prot->name);
2227			goto out;
2228		}
2229
2230		if (prot->rsk_prot != NULL) {
2231			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
2232			if (prot->rsk_prot->slab_name == NULL)
2233				goto out_free_sock_slab;
2234
2235			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
2236								 prot->rsk_prot->obj_size, 0,
2237								 SLAB_HWCACHE_ALIGN, NULL);
2238
2239			if (prot->rsk_prot->slab == NULL) {
2240				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
2241				       prot->name);
2242				goto out_free_request_sock_slab_name;
2243			}
2244		}
2245
2246		if (prot->twsk_prot != NULL) {
2247			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
2248
2249			if (prot->twsk_prot->twsk_slab_name == NULL)
2250				goto out_free_request_sock_slab;
2251
2252			prot->twsk_prot->twsk_slab =
2253				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
2254						  prot->twsk_prot->twsk_obj_size,
2255						  0,
2256						  SLAB_HWCACHE_ALIGN |
2257							prot->slab_flags,
2258						  NULL);
2259			if (prot->twsk_prot->twsk_slab == NULL)
2260				goto out_free_timewait_sock_slab_name;
2261		}
2262	}
2263
2264	write_lock(&proto_list_lock);
2265	list_add(&prot->node, &proto_list);
2266	assign_proto_idx(prot);
2267	write_unlock(&proto_list_lock);
2268	return 0;
2269
2270out_free_timewait_sock_slab_name:
2271	kfree(prot->twsk_prot->twsk_slab_name);
2272out_free_request_sock_slab:
2273	if (prot->rsk_prot && prot->rsk_prot->slab) {
2274		kmem_cache_destroy(prot->rsk_prot->slab);
2275		prot->rsk_prot->slab = NULL;
2276	}
2277out_free_request_sock_slab_name:
2278	kfree(prot->rsk_prot->slab_name);
2279out_free_sock_slab:
2280	kmem_cache_destroy(prot->slab);
2281	prot->slab = NULL;
2282out:
2283	return -ENOBUFS;
2284}
2285EXPORT_SYMBOL(proto_register);
2286
2287void proto_unregister(struct proto *prot)
2288{
2289	write_lock(&proto_list_lock);
2290	release_proto_idx(prot);
2291	list_del(&prot->node);
2292	write_unlock(&proto_list_lock);
2293
2294	if (prot->slab != NULL) {
2295		kmem_cache_destroy(prot->slab);
2296		prot->slab = NULL;
2297	}
2298
2299	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
2300		kmem_cache_destroy(prot->rsk_prot->slab);
2301		kfree(prot->rsk_prot->slab_name);
2302		prot->rsk_prot->slab = NULL;
2303	}
2304
2305	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
2306		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
2307		kfree(prot->twsk_prot->twsk_slab_name);
2308		prot->twsk_prot->twsk_slab = NULL;
2309	}
2310}
2311EXPORT_SYMBOL(proto_unregister);
2312
2313#ifdef CONFIG_PROC_FS
2314static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
2315	__acquires(proto_list_lock)
2316{
2317	read_lock(&proto_list_lock);
2318	return seq_list_start_head(&proto_list, *pos);
2319}
2320
2321static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2322{
2323	return seq_list_next(v, &proto_list, pos);
2324}
2325
2326static void proto_seq_stop(struct seq_file *seq, void *v)
2327	__releases(proto_list_lock)
2328{
2329	read_unlock(&proto_list_lock);
2330}
2331
2332static char proto_method_implemented(const void *method)
2333{
2334	return method == NULL ? 'n' : 'y';
2335}
2336
2337static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
2338{
2339	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
2340			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
2341		   proto->name,
2342		   proto->obj_size,
2343		   sock_prot_inuse_get(seq_file_net(seq), proto),
2344		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
2345		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
2346		   proto->max_header,
2347		   proto->slab == NULL ? "no" : "yes",
2348		   module_name(proto->owner),
2349		   proto_method_implemented(proto->close),
2350		   proto_method_implemented(proto->connect),
2351		   proto_method_implemented(proto->disconnect),
2352		   proto_method_implemented(proto->accept),
2353		   proto_method_implemented(proto->ioctl),
2354		   proto_method_implemented(proto->init),
2355		   proto_method_implemented(proto->destroy),
2356		   proto_method_implemented(proto->shutdown),
2357		   proto_method_implemented(proto->setsockopt),
2358		   proto_method_implemented(proto->getsockopt),
2359		   proto_method_implemented(proto->sendmsg),
2360		   proto_method_implemented(proto->recvmsg),
2361		   proto_method_implemented(proto->sendpage),
2362		   proto_method_implemented(proto->bind),
2363		   proto_method_implemented(proto->backlog_rcv),
2364		   proto_method_implemented(proto->hash),
2365		   proto_method_implemented(proto->unhash),
2366		   proto_method_implemented(proto->get_port),
2367		   proto_method_implemented(proto->enter_memory_pressure));
2368}
2369
2370static int proto_seq_show(struct seq_file *seq, void *v)
2371{
2372	if (v == &proto_list)
2373		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
2374			   "protocol",
2375			   "size",
2376			   "sockets",
2377			   "memory",
2378			   "press",
2379			   "maxhdr",
2380			   "slab",
2381			   "module",
2382			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
2383	else
2384		proto_seq_printf(seq, list_entry(v, struct proto, node));
2385	return 0;
2386}
2387
2388static const struct seq_operations proto_seq_ops = {
2389	.start  = proto_seq_start,
2390	.next   = proto_seq_next,
2391	.stop   = proto_seq_stop,
2392	.show   = proto_seq_show,
2393};
2394
2395static int proto_seq_open(struct inode *inode, struct file *file)
2396{
2397	return seq_open_net(inode, file, &proto_seq_ops,
2398			    sizeof(struct seq_net_private));
2399}
2400
2401static const struct file_operations proto_seq_fops = {
2402	.owner		= THIS_MODULE,
2403	.open		= proto_seq_open,
2404	.read		= seq_read,
2405	.llseek		= seq_lseek,
2406	.release	= seq_release_net,
2407};
2408
2409static __net_init int proto_init_net(struct net *net)
2410{
2411	if (!proc_net_fops_create(net, "protocols", S_IRUGO, &proto_seq_fops))
2412		return -ENOMEM;
2413
2414	return 0;
2415}
2416
2417static __net_exit void proto_exit_net(struct net *net)
2418{
2419	proc_net_remove(net, "protocols");
2420}
2421
2422
2423static __net_initdata struct pernet_operations proto_net_ops = {
2424	.init = proto_init_net,
2425	.exit = proto_exit_net,
2426};
2427
2428static int __init proto_init(void)
2429{
2430	return register_pernet_subsys(&proto_net_ops);
2431}
2432
2433subsys_initcall(proto_init);
2434
2435#endif /* PROC_FS */
2436