sock.c revision 6d6ee43e0b8b8d4847627fd43739b98ec2b9404f
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 * Version:	$Id: sock.c,v 1.117 2002/02/01 22:01:03 davem Exp $
11 *
12 * Authors:	Ross Biro
13 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
14 *		Florian La Roche, <flla@stud.uni-sb.de>
15 *		Alan Cox, <A.Cox@swansea.ac.uk>
16 *
17 * Fixes:
18 *		Alan Cox	: 	Numerous verify_area() problems
19 *		Alan Cox	:	Connecting on a connecting socket
20 *					now returns an error for tcp.
21 *		Alan Cox	:	sock->protocol is set correctly.
22 *					and is not sometimes left as 0.
23 *		Alan Cox	:	connect handles icmp errors on a
24 *					connect properly. Unfortunately there
25 *					is a restart syscall nasty there. I
26 *					can't match BSD without hacking the C
27 *					library. Ideas urgently sought!
28 *		Alan Cox	:	Disallow bind() to addresses that are
29 *					not ours - especially broadcast ones!!
30 *		Alan Cox	:	Socket 1024 _IS_ ok for users. (fencepost)
31 *		Alan Cox	:	sock_wfree/sock_rfree don't destroy sockets,
32 *					instead they leave that for the DESTROY timer.
33 *		Alan Cox	:	Clean up error flag in accept
34 *		Alan Cox	:	TCP ack handling is buggy, the DESTROY timer
35 *					was buggy. Put a remove_sock() in the handler
36 *					for memory when we hit 0. Also altered the timer
37 *					code. The ACK stuff can wait and needs major
38 *					TCP layer surgery.
39 *		Alan Cox	:	Fixed TCP ack bug, removed remove sock
40 *					and fixed timer/inet_bh race.
41 *		Alan Cox	:	Added zapped flag for TCP
42 *		Alan Cox	:	Move kfree_skb into skbuff.c and tidied up surplus code
43 *		Alan Cox	:	for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
44 *		Alan Cox	:	kfree_s calls now are kfree_skbmem so we can track skb resources
45 *		Alan Cox	:	Supports socket option broadcast now as does udp. Packet and raw need fixing.
46 *		Alan Cox	:	Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
47 *		Rick Sladkey	:	Relaxed UDP rules for matching packets.
48 *		C.E.Hawkins	:	IFF_PROMISC/SIOCGHWADDR support
49 *	Pauline Middelink	:	identd support
50 *		Alan Cox	:	Fixed connect() taking signals I think.
51 *		Alan Cox	:	SO_LINGER supported
52 *		Alan Cox	:	Error reporting fixes
53 *		Anonymous	:	inet_create tidied up (sk->reuse setting)
54 *		Alan Cox	:	inet sockets don't set sk->type!
55 *		Alan Cox	:	Split socket option code
56 *		Alan Cox	:	Callbacks
57 *		Alan Cox	:	Nagle flag for Charles & Johannes stuff
58 *		Alex		:	Removed restriction on inet fioctl
59 *		Alan Cox	:	Splitting INET from NET core
60 *		Alan Cox	:	Fixed bogus SO_TYPE handling in getsockopt()
61 *		Adam Caldwell	:	Missing return in SO_DONTROUTE/SO_DEBUG code
62 *		Alan Cox	:	Split IP from generic code
63 *		Alan Cox	:	New kfree_skbmem()
64 *		Alan Cox	:	Make SO_DEBUG superuser only.
65 *		Alan Cox	:	Allow anyone to clear SO_DEBUG
66 *					(compatibility fix)
67 *		Alan Cox	:	Added optimistic memory grabbing for AF_UNIX throughput.
68 *		Alan Cox	:	Allocator for a socket is settable.
69 *		Alan Cox	:	SO_ERROR includes soft errors.
70 *		Alan Cox	:	Allow NULL arguments on some SO_ opts
71 *		Alan Cox	: 	Generic socket allocation to make hooks
72 *					easier (suggested by Craig Metz).
73 *		Michael Pall	:	SO_ERROR returns positive errno again
74 *              Steve Whitehouse:       Added default destructor to free
75 *                                      protocol private data.
76 *              Steve Whitehouse:       Added various other default routines
77 *                                      common to several socket families.
78 *              Chris Evans     :       Call suser() check last on F_SETOWN
79 *		Jay Schulist	:	Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
80 *		Andi Kleen	:	Add sock_kmalloc()/sock_kfree_s()
81 *		Andi Kleen	:	Fix write_space callback
82 *		Chris Evans	:	Security fixes - signedness again
83 *		Arnaldo C. Melo :       cleanups, use skb_queue_purge
84 *
85 * To Fix:
86 *
87 *
88 *		This program is free software; you can redistribute it and/or
89 *		modify it under the terms of the GNU General Public License
90 *		as published by the Free Software Foundation; either version
91 *		2 of the License, or (at your option) any later version.
92 */
93
94#include <linux/config.h>
95#include <linux/errno.h>
96#include <linux/types.h>
97#include <linux/socket.h>
98#include <linux/in.h>
99#include <linux/kernel.h>
100#include <linux/module.h>
101#include <linux/proc_fs.h>
102#include <linux/seq_file.h>
103#include <linux/sched.h>
104#include <linux/timer.h>
105#include <linux/string.h>
106#include <linux/sockios.h>
107#include <linux/net.h>
108#include <linux/mm.h>
109#include <linux/slab.h>
110#include <linux/interrupt.h>
111#include <linux/poll.h>
112#include <linux/tcp.h>
113#include <linux/init.h>
114
115#include <asm/uaccess.h>
116#include <asm/system.h>
117
118#include <linux/netdevice.h>
119#include <net/protocol.h>
120#include <linux/skbuff.h>
121#include <net/request_sock.h>
122#include <net/sock.h>
123#include <net/xfrm.h>
124#include <linux/ipsec.h>
125
126#include <linux/filter.h>
127
128#ifdef CONFIG_INET
129#include <net/tcp.h>
130#endif
131
132/* Take into consideration the size of the struct sk_buff overhead in the
133 * determination of these values, since that is non-constant across
134 * platforms.  This makes socket queueing behavior and performance
135 * not depend upon such differences.
136 */
137#define _SK_MEM_PACKETS		256
138#define _SK_MEM_OVERHEAD	(sizeof(struct sk_buff) + 256)
139#define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
140#define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
141
142/* Run time adjustable parameters. */
143__u32 sysctl_wmem_max = SK_WMEM_MAX;
144__u32 sysctl_rmem_max = SK_RMEM_MAX;
145__u32 sysctl_wmem_default = SK_WMEM_MAX;
146__u32 sysctl_rmem_default = SK_RMEM_MAX;
147
148/* Maximal space eaten by iovec or ancilliary data plus some space */
149int sysctl_optmem_max = sizeof(unsigned long)*(2*UIO_MAXIOV + 512);
150
151static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
152{
153	struct timeval tv;
154
155	if (optlen < sizeof(tv))
156		return -EINVAL;
157	if (copy_from_user(&tv, optval, sizeof(tv)))
158		return -EFAULT;
159
160	*timeo_p = MAX_SCHEDULE_TIMEOUT;
161	if (tv.tv_sec == 0 && tv.tv_usec == 0)
162		return 0;
163	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
164		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
165	return 0;
166}
167
168static void sock_warn_obsolete_bsdism(const char *name)
169{
170	static int warned;
171	static char warncomm[TASK_COMM_LEN];
172	if (strcmp(warncomm, current->comm) && warned < 5) {
173		strcpy(warncomm,  current->comm);
174		printk(KERN_WARNING "process `%s' is using obsolete "
175		       "%s SO_BSDCOMPAT\n", warncomm, name);
176		warned++;
177	}
178}
179
180static void sock_disable_timestamp(struct sock *sk)
181{
182	if (sock_flag(sk, SOCK_TIMESTAMP)) {
183		sock_reset_flag(sk, SOCK_TIMESTAMP);
184		net_disable_timestamp();
185	}
186}
187
188
189/*
190 *	This is meant for all protocols to use and covers goings on
191 *	at the socket level. Everything here is generic.
192 */
193
194int sock_setsockopt(struct socket *sock, int level, int optname,
195		    char __user *optval, int optlen)
196{
197	struct sock *sk=sock->sk;
198	struct sk_filter *filter;
199	int val;
200	int valbool;
201	struct linger ling;
202	int ret = 0;
203
204	/*
205	 *	Options without arguments
206	 */
207
208#ifdef SO_DONTLINGER		/* Compatibility item... */
209	if (optname == SO_DONTLINGER) {
210		lock_sock(sk);
211		sock_reset_flag(sk, SOCK_LINGER);
212		release_sock(sk);
213		return 0;
214	}
215#endif
216
217  	if(optlen<sizeof(int))
218  		return(-EINVAL);
219
220	if (get_user(val, (int __user *)optval))
221		return -EFAULT;
222
223  	valbool = val?1:0;
224
225	lock_sock(sk);
226
227  	switch(optname)
228  	{
229		case SO_DEBUG:
230			if(val && !capable(CAP_NET_ADMIN))
231			{
232				ret = -EACCES;
233			}
234			else if (valbool)
235				sock_set_flag(sk, SOCK_DBG);
236			else
237				sock_reset_flag(sk, SOCK_DBG);
238			break;
239		case SO_REUSEADDR:
240			sk->sk_reuse = valbool;
241			break;
242		case SO_TYPE:
243		case SO_ERROR:
244			ret = -ENOPROTOOPT;
245		  	break;
246		case SO_DONTROUTE:
247			if (valbool)
248				sock_set_flag(sk, SOCK_LOCALROUTE);
249			else
250				sock_reset_flag(sk, SOCK_LOCALROUTE);
251			break;
252		case SO_BROADCAST:
253			sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
254			break;
255		case SO_SNDBUF:
256			/* Don't error on this BSD doesn't and if you think
257			   about it this is right. Otherwise apps have to
258			   play 'guess the biggest size' games. RCVBUF/SNDBUF
259			   are treated in BSD as hints */
260
261			if (val > sysctl_wmem_max)
262				val = sysctl_wmem_max;
263set_sndbuf:
264			sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
265			if ((val * 2) < SOCK_MIN_SNDBUF)
266				sk->sk_sndbuf = SOCK_MIN_SNDBUF;
267			else
268				sk->sk_sndbuf = val * 2;
269
270			/*
271			 *	Wake up sending tasks if we
272			 *	upped the value.
273			 */
274			sk->sk_write_space(sk);
275			break;
276
277		case SO_SNDBUFFORCE:
278			if (!capable(CAP_NET_ADMIN)) {
279				ret = -EPERM;
280				break;
281			}
282			goto set_sndbuf;
283
284		case SO_RCVBUF:
285			/* Don't error on this BSD doesn't and if you think
286			   about it this is right. Otherwise apps have to
287			   play 'guess the biggest size' games. RCVBUF/SNDBUF
288			   are treated in BSD as hints */
289
290			if (val > sysctl_rmem_max)
291				val = sysctl_rmem_max;
292set_rcvbuf:
293			sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
294			/* FIXME: is this lower bound the right one? */
295			if ((val * 2) < SOCK_MIN_RCVBUF)
296				sk->sk_rcvbuf = SOCK_MIN_RCVBUF;
297			else
298				sk->sk_rcvbuf = val * 2;
299			break;
300
301		case SO_RCVBUFFORCE:
302			if (!capable(CAP_NET_ADMIN)) {
303				ret = -EPERM;
304				break;
305			}
306			goto set_rcvbuf;
307
308		case SO_KEEPALIVE:
309#ifdef CONFIG_INET
310			if (sk->sk_protocol == IPPROTO_TCP)
311				tcp_set_keepalive(sk, valbool);
312#endif
313			sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
314			break;
315
316	 	case SO_OOBINLINE:
317			sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
318			break;
319
320	 	case SO_NO_CHECK:
321			sk->sk_no_check = valbool;
322			break;
323
324		case SO_PRIORITY:
325			if ((val >= 0 && val <= 6) || capable(CAP_NET_ADMIN))
326				sk->sk_priority = val;
327			else
328				ret = -EPERM;
329			break;
330
331		case SO_LINGER:
332			if(optlen<sizeof(ling)) {
333				ret = -EINVAL;	/* 1003.1g */
334				break;
335			}
336			if (copy_from_user(&ling,optval,sizeof(ling))) {
337				ret = -EFAULT;
338				break;
339			}
340			if (!ling.l_onoff)
341				sock_reset_flag(sk, SOCK_LINGER);
342			else {
343#if (BITS_PER_LONG == 32)
344				if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
345					sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
346				else
347#endif
348					sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
349				sock_set_flag(sk, SOCK_LINGER);
350			}
351			break;
352
353		case SO_BSDCOMPAT:
354			sock_warn_obsolete_bsdism("setsockopt");
355			break;
356
357		case SO_PASSCRED:
358			if (valbool)
359				set_bit(SOCK_PASSCRED, &sock->flags);
360			else
361				clear_bit(SOCK_PASSCRED, &sock->flags);
362			break;
363
364		case SO_TIMESTAMP:
365			if (valbool)  {
366				sock_set_flag(sk, SOCK_RCVTSTAMP);
367				sock_enable_timestamp(sk);
368			} else
369				sock_reset_flag(sk, SOCK_RCVTSTAMP);
370			break;
371
372		case SO_RCVLOWAT:
373			if (val < 0)
374				val = INT_MAX;
375			sk->sk_rcvlowat = val ? : 1;
376			break;
377
378		case SO_RCVTIMEO:
379			ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
380			break;
381
382		case SO_SNDTIMEO:
383			ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
384			break;
385
386#ifdef CONFIG_NETDEVICES
387		case SO_BINDTODEVICE:
388		{
389			char devname[IFNAMSIZ];
390
391			/* Sorry... */
392			if (!capable(CAP_NET_RAW)) {
393				ret = -EPERM;
394				break;
395			}
396
397			/* Bind this socket to a particular device like "eth0",
398			 * as specified in the passed interface name. If the
399			 * name is "" or the option length is zero the socket
400			 * is not bound.
401			 */
402
403			if (!valbool) {
404				sk->sk_bound_dev_if = 0;
405			} else {
406				if (optlen > IFNAMSIZ)
407					optlen = IFNAMSIZ;
408				if (copy_from_user(devname, optval, optlen)) {
409					ret = -EFAULT;
410					break;
411				}
412
413				/* Remove any cached route for this socket. */
414				sk_dst_reset(sk);
415
416				if (devname[0] == '\0') {
417					sk->sk_bound_dev_if = 0;
418				} else {
419					struct net_device *dev = dev_get_by_name(devname);
420					if (!dev) {
421						ret = -ENODEV;
422						break;
423					}
424					sk->sk_bound_dev_if = dev->ifindex;
425					dev_put(dev);
426				}
427			}
428			break;
429		}
430#endif
431
432
433		case SO_ATTACH_FILTER:
434			ret = -EINVAL;
435			if (optlen == sizeof(struct sock_fprog)) {
436				struct sock_fprog fprog;
437
438				ret = -EFAULT;
439				if (copy_from_user(&fprog, optval, sizeof(fprog)))
440					break;
441
442				ret = sk_attach_filter(&fprog, sk);
443			}
444			break;
445
446		case SO_DETACH_FILTER:
447			spin_lock_bh(&sk->sk_lock.slock);
448			filter = sk->sk_filter;
449                        if (filter) {
450				sk->sk_filter = NULL;
451				spin_unlock_bh(&sk->sk_lock.slock);
452				sk_filter_release(sk, filter);
453				break;
454			}
455			spin_unlock_bh(&sk->sk_lock.slock);
456			ret = -ENONET;
457			break;
458
459		/* We implement the SO_SNDLOWAT etc to
460		   not be settable (1003.1g 5.3) */
461		default:
462		  	ret = -ENOPROTOOPT;
463			break;
464  	}
465	release_sock(sk);
466	return ret;
467}
468
469
470int sock_getsockopt(struct socket *sock, int level, int optname,
471		    char __user *optval, int __user *optlen)
472{
473	struct sock *sk = sock->sk;
474
475	union
476	{
477  		int val;
478  		struct linger ling;
479		struct timeval tm;
480	} v;
481
482	unsigned int lv = sizeof(int);
483	int len;
484
485  	if(get_user(len,optlen))
486  		return -EFAULT;
487	if(len < 0)
488		return -EINVAL;
489
490  	switch(optname)
491  	{
492		case SO_DEBUG:
493			v.val = sock_flag(sk, SOCK_DBG);
494			break;
495
496		case SO_DONTROUTE:
497			v.val = sock_flag(sk, SOCK_LOCALROUTE);
498			break;
499
500		case SO_BROADCAST:
501			v.val = !!sock_flag(sk, SOCK_BROADCAST);
502			break;
503
504		case SO_SNDBUF:
505			v.val = sk->sk_sndbuf;
506			break;
507
508		case SO_RCVBUF:
509			v.val = sk->sk_rcvbuf;
510			break;
511
512		case SO_REUSEADDR:
513			v.val = sk->sk_reuse;
514			break;
515
516		case SO_KEEPALIVE:
517			v.val = !!sock_flag(sk, SOCK_KEEPOPEN);
518			break;
519
520		case SO_TYPE:
521			v.val = sk->sk_type;
522			break;
523
524		case SO_ERROR:
525			v.val = -sock_error(sk);
526			if(v.val==0)
527				v.val = xchg(&sk->sk_err_soft, 0);
528			break;
529
530		case SO_OOBINLINE:
531			v.val = !!sock_flag(sk, SOCK_URGINLINE);
532			break;
533
534		case SO_NO_CHECK:
535			v.val = sk->sk_no_check;
536			break;
537
538		case SO_PRIORITY:
539			v.val = sk->sk_priority;
540			break;
541
542		case SO_LINGER:
543			lv		= sizeof(v.ling);
544			v.ling.l_onoff	= !!sock_flag(sk, SOCK_LINGER);
545 			v.ling.l_linger	= sk->sk_lingertime / HZ;
546			break;
547
548		case SO_BSDCOMPAT:
549			sock_warn_obsolete_bsdism("getsockopt");
550			break;
551
552		case SO_TIMESTAMP:
553			v.val = sock_flag(sk, SOCK_RCVTSTAMP);
554			break;
555
556		case SO_RCVTIMEO:
557			lv=sizeof(struct timeval);
558			if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
559				v.tm.tv_sec = 0;
560				v.tm.tv_usec = 0;
561			} else {
562				v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
563				v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
564			}
565			break;
566
567		case SO_SNDTIMEO:
568			lv=sizeof(struct timeval);
569			if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
570				v.tm.tv_sec = 0;
571				v.tm.tv_usec = 0;
572			} else {
573				v.tm.tv_sec = sk->sk_sndtimeo / HZ;
574				v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
575			}
576			break;
577
578		case SO_RCVLOWAT:
579			v.val = sk->sk_rcvlowat;
580			break;
581
582		case SO_SNDLOWAT:
583			v.val=1;
584			break;
585
586		case SO_PASSCRED:
587			v.val = test_bit(SOCK_PASSCRED, &sock->flags) ? 1 : 0;
588			break;
589
590		case SO_PEERCRED:
591			if (len > sizeof(sk->sk_peercred))
592				len = sizeof(sk->sk_peercred);
593			if (copy_to_user(optval, &sk->sk_peercred, len))
594				return -EFAULT;
595			goto lenout;
596
597		case SO_PEERNAME:
598		{
599			char address[128];
600
601			if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
602				return -ENOTCONN;
603			if (lv < len)
604				return -EINVAL;
605			if (copy_to_user(optval, address, len))
606				return -EFAULT;
607			goto lenout;
608		}
609
610		/* Dubious BSD thing... Probably nobody even uses it, but
611		 * the UNIX standard wants it for whatever reason... -DaveM
612		 */
613		case SO_ACCEPTCONN:
614			v.val = sk->sk_state == TCP_LISTEN;
615			break;
616
617		case SO_PEERSEC:
618			return security_socket_getpeersec(sock, optval, optlen, len);
619
620		default:
621			return(-ENOPROTOOPT);
622	}
623	if (len > lv)
624		len = lv;
625	if (copy_to_user(optval, &v, len))
626		return -EFAULT;
627lenout:
628  	if (put_user(len, optlen))
629  		return -EFAULT;
630  	return 0;
631}
632
633/**
634 *	sk_alloc - All socket objects are allocated here
635 *	@family: protocol family
636 *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
637 *	@prot: struct proto associated with this new sock instance
638 *	@zero_it: if we should zero the newly allocated sock
639 */
640struct sock *sk_alloc(int family, gfp_t priority,
641		      struct proto *prot, int zero_it)
642{
643	struct sock *sk = NULL;
644	kmem_cache_t *slab = prot->slab;
645
646	if (slab != NULL)
647		sk = kmem_cache_alloc(slab, priority);
648	else
649		sk = kmalloc(prot->obj_size, priority);
650
651	if (sk) {
652		if (zero_it) {
653			memset(sk, 0, prot->obj_size);
654			sk->sk_family = family;
655			/*
656			 * See comment in struct sock definition to understand
657			 * why we need sk_prot_creator -acme
658			 */
659			sk->sk_prot = sk->sk_prot_creator = prot;
660			sock_lock_init(sk);
661		}
662
663		if (security_sk_alloc(sk, family, priority))
664			goto out_free;
665
666		if (!try_module_get(prot->owner))
667			goto out_free;
668	}
669	return sk;
670
671out_free:
672	if (slab != NULL)
673		kmem_cache_free(slab, sk);
674	else
675		kfree(sk);
676	return NULL;
677}
678
679void sk_free(struct sock *sk)
680{
681	struct sk_filter *filter;
682	struct module *owner = sk->sk_prot_creator->owner;
683
684	if (sk->sk_destruct)
685		sk->sk_destruct(sk);
686
687	filter = sk->sk_filter;
688	if (filter) {
689		sk_filter_release(sk, filter);
690		sk->sk_filter = NULL;
691	}
692
693	sock_disable_timestamp(sk);
694
695	if (atomic_read(&sk->sk_omem_alloc))
696		printk(KERN_DEBUG "%s: optmem leakage (%d bytes) detected.\n",
697		       __FUNCTION__, atomic_read(&sk->sk_omem_alloc));
698
699	security_sk_free(sk);
700	if (sk->sk_prot_creator->slab != NULL)
701		kmem_cache_free(sk->sk_prot_creator->slab, sk);
702	else
703		kfree(sk);
704	module_put(owner);
705}
706
707struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
708{
709	struct sock *newsk = sk_alloc(sk->sk_family, priority, sk->sk_prot, 0);
710
711	if (newsk != NULL) {
712		struct sk_filter *filter;
713
714		memcpy(newsk, sk, sk->sk_prot->obj_size);
715
716		/* SANITY */
717		sk_node_init(&newsk->sk_node);
718		sock_lock_init(newsk);
719		bh_lock_sock(newsk);
720
721		atomic_set(&newsk->sk_rmem_alloc, 0);
722		atomic_set(&newsk->sk_wmem_alloc, 0);
723		atomic_set(&newsk->sk_omem_alloc, 0);
724		skb_queue_head_init(&newsk->sk_receive_queue);
725		skb_queue_head_init(&newsk->sk_write_queue);
726
727		rwlock_init(&newsk->sk_dst_lock);
728		rwlock_init(&newsk->sk_callback_lock);
729
730		newsk->sk_dst_cache	= NULL;
731		newsk->sk_wmem_queued	= 0;
732		newsk->sk_forward_alloc = 0;
733		newsk->sk_send_head	= NULL;
734		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
735		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
736
737		sock_reset_flag(newsk, SOCK_DONE);
738		skb_queue_head_init(&newsk->sk_error_queue);
739
740		filter = newsk->sk_filter;
741		if (filter != NULL)
742			sk_filter_charge(newsk, filter);
743
744		if (unlikely(xfrm_sk_clone_policy(newsk))) {
745			/* It is still raw copy of parent, so invalidate
746			 * destructor and make plain sk_free() */
747			newsk->sk_destruct = NULL;
748			sk_free(newsk);
749			newsk = NULL;
750			goto out;
751		}
752
753		newsk->sk_err	   = 0;
754		newsk->sk_priority = 0;
755		atomic_set(&newsk->sk_refcnt, 2);
756
757		/*
758		 * Increment the counter in the same struct proto as the master
759		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
760		 * is the same as sk->sk_prot->socks, as this field was copied
761		 * with memcpy).
762		 *
763		 * This _changes_ the previous behaviour, where
764		 * tcp_create_openreq_child always was incrementing the
765		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
766		 * to be taken into account in all callers. -acme
767		 */
768		sk_refcnt_debug_inc(newsk);
769		newsk->sk_socket = NULL;
770		newsk->sk_sleep	 = NULL;
771
772		if (newsk->sk_prot->sockets_allocated)
773			atomic_inc(newsk->sk_prot->sockets_allocated);
774	}
775out:
776	return newsk;
777}
778
779EXPORT_SYMBOL_GPL(sk_clone);
780
781void __init sk_init(void)
782{
783	if (num_physpages <= 4096) {
784		sysctl_wmem_max = 32767;
785		sysctl_rmem_max = 32767;
786		sysctl_wmem_default = 32767;
787		sysctl_rmem_default = 32767;
788	} else if (num_physpages >= 131072) {
789		sysctl_wmem_max = 131071;
790		sysctl_rmem_max = 131071;
791	}
792}
793
794/*
795 *	Simple resource managers for sockets.
796 */
797
798
799/*
800 * Write buffer destructor automatically called from kfree_skb.
801 */
802void sock_wfree(struct sk_buff *skb)
803{
804	struct sock *sk = skb->sk;
805
806	/* In case it might be waiting for more memory. */
807	atomic_sub(skb->truesize, &sk->sk_wmem_alloc);
808	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE))
809		sk->sk_write_space(sk);
810	sock_put(sk);
811}
812
813/*
814 * Read buffer destructor automatically called from kfree_skb.
815 */
816void sock_rfree(struct sk_buff *skb)
817{
818	struct sock *sk = skb->sk;
819
820	atomic_sub(skb->truesize, &sk->sk_rmem_alloc);
821}
822
823
824int sock_i_uid(struct sock *sk)
825{
826	int uid;
827
828	read_lock(&sk->sk_callback_lock);
829	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : 0;
830	read_unlock(&sk->sk_callback_lock);
831	return uid;
832}
833
834unsigned long sock_i_ino(struct sock *sk)
835{
836	unsigned long ino;
837
838	read_lock(&sk->sk_callback_lock);
839	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
840	read_unlock(&sk->sk_callback_lock);
841	return ino;
842}
843
844/*
845 * Allocate a skb from the socket's send buffer.
846 */
847struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
848			     gfp_t priority)
849{
850	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
851		struct sk_buff * skb = alloc_skb(size, priority);
852		if (skb) {
853			skb_set_owner_w(skb, sk);
854			return skb;
855		}
856	}
857	return NULL;
858}
859
860/*
861 * Allocate a skb from the socket's receive buffer.
862 */
863struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
864			     gfp_t priority)
865{
866	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
867		struct sk_buff *skb = alloc_skb(size, priority);
868		if (skb) {
869			skb_set_owner_r(skb, sk);
870			return skb;
871		}
872	}
873	return NULL;
874}
875
876/*
877 * Allocate a memory block from the socket's option memory buffer.
878 */
879void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
880{
881	if ((unsigned)size <= sysctl_optmem_max &&
882	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
883		void *mem;
884		/* First do the add, to avoid the race if kmalloc
885 		 * might sleep.
886		 */
887		atomic_add(size, &sk->sk_omem_alloc);
888		mem = kmalloc(size, priority);
889		if (mem)
890			return mem;
891		atomic_sub(size, &sk->sk_omem_alloc);
892	}
893	return NULL;
894}
895
896/*
897 * Free an option memory block.
898 */
899void sock_kfree_s(struct sock *sk, void *mem, int size)
900{
901	kfree(mem);
902	atomic_sub(size, &sk->sk_omem_alloc);
903}
904
905/* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
906   I think, these locks should be removed for datagram sockets.
907 */
908static long sock_wait_for_wmem(struct sock * sk, long timeo)
909{
910	DEFINE_WAIT(wait);
911
912	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
913	for (;;) {
914		if (!timeo)
915			break;
916		if (signal_pending(current))
917			break;
918		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
919		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
920		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
921			break;
922		if (sk->sk_shutdown & SEND_SHUTDOWN)
923			break;
924		if (sk->sk_err)
925			break;
926		timeo = schedule_timeout(timeo);
927	}
928	finish_wait(sk->sk_sleep, &wait);
929	return timeo;
930}
931
932
933/*
934 *	Generic send/receive buffer handlers
935 */
936
937static struct sk_buff *sock_alloc_send_pskb(struct sock *sk,
938					    unsigned long header_len,
939					    unsigned long data_len,
940					    int noblock, int *errcode)
941{
942	struct sk_buff *skb;
943	gfp_t gfp_mask;
944	long timeo;
945	int err;
946
947	gfp_mask = sk->sk_allocation;
948	if (gfp_mask & __GFP_WAIT)
949		gfp_mask |= __GFP_REPEAT;
950
951	timeo = sock_sndtimeo(sk, noblock);
952	while (1) {
953		err = sock_error(sk);
954		if (err != 0)
955			goto failure;
956
957		err = -EPIPE;
958		if (sk->sk_shutdown & SEND_SHUTDOWN)
959			goto failure;
960
961		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
962			skb = alloc_skb(header_len, sk->sk_allocation);
963			if (skb) {
964				int npages;
965				int i;
966
967				/* No pages, we're done... */
968				if (!data_len)
969					break;
970
971				npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
972				skb->truesize += data_len;
973				skb_shinfo(skb)->nr_frags = npages;
974				for (i = 0; i < npages; i++) {
975					struct page *page;
976					skb_frag_t *frag;
977
978					page = alloc_pages(sk->sk_allocation, 0);
979					if (!page) {
980						err = -ENOBUFS;
981						skb_shinfo(skb)->nr_frags = i;
982						kfree_skb(skb);
983						goto failure;
984					}
985
986					frag = &skb_shinfo(skb)->frags[i];
987					frag->page = page;
988					frag->page_offset = 0;
989					frag->size = (data_len >= PAGE_SIZE ?
990						      PAGE_SIZE :
991						      data_len);
992					data_len -= PAGE_SIZE;
993				}
994
995				/* Full success... */
996				break;
997			}
998			err = -ENOBUFS;
999			goto failure;
1000		}
1001		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
1002		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
1003		err = -EAGAIN;
1004		if (!timeo)
1005			goto failure;
1006		if (signal_pending(current))
1007			goto interrupted;
1008		timeo = sock_wait_for_wmem(sk, timeo);
1009	}
1010
1011	skb_set_owner_w(skb, sk);
1012	return skb;
1013
1014interrupted:
1015	err = sock_intr_errno(timeo);
1016failure:
1017	*errcode = err;
1018	return NULL;
1019}
1020
1021struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
1022				    int noblock, int *errcode)
1023{
1024	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
1025}
1026
1027static void __lock_sock(struct sock *sk)
1028{
1029	DEFINE_WAIT(wait);
1030
1031	for(;;) {
1032		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
1033					TASK_UNINTERRUPTIBLE);
1034		spin_unlock_bh(&sk->sk_lock.slock);
1035		schedule();
1036		spin_lock_bh(&sk->sk_lock.slock);
1037		if(!sock_owned_by_user(sk))
1038			break;
1039	}
1040	finish_wait(&sk->sk_lock.wq, &wait);
1041}
1042
1043static void __release_sock(struct sock *sk)
1044{
1045	struct sk_buff *skb = sk->sk_backlog.head;
1046
1047	do {
1048		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
1049		bh_unlock_sock(sk);
1050
1051		do {
1052			struct sk_buff *next = skb->next;
1053
1054			skb->next = NULL;
1055			sk->sk_backlog_rcv(sk, skb);
1056
1057			/*
1058			 * We are in process context here with softirqs
1059			 * disabled, use cond_resched_softirq() to preempt.
1060			 * This is safe to do because we've taken the backlog
1061			 * queue private:
1062			 */
1063			cond_resched_softirq();
1064
1065			skb = next;
1066		} while (skb != NULL);
1067
1068		bh_lock_sock(sk);
1069	} while((skb = sk->sk_backlog.head) != NULL);
1070}
1071
1072/**
1073 * sk_wait_data - wait for data to arrive at sk_receive_queue
1074 * @sk:    sock to wait on
1075 * @timeo: for how long
1076 *
1077 * Now socket state including sk->sk_err is changed only under lock,
1078 * hence we may omit checks after joining wait queue.
1079 * We check receive queue before schedule() only as optimization;
1080 * it is very likely that release_sock() added new data.
1081 */
1082int sk_wait_data(struct sock *sk, long *timeo)
1083{
1084	int rc;
1085	DEFINE_WAIT(wait);
1086
1087	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
1088	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1089	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
1090	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
1091	finish_wait(sk->sk_sleep, &wait);
1092	return rc;
1093}
1094
1095EXPORT_SYMBOL(sk_wait_data);
1096
1097/*
1098 * Set of default routines for initialising struct proto_ops when
1099 * the protocol does not support a particular function. In certain
1100 * cases where it makes no sense for a protocol to have a "do nothing"
1101 * function, some default processing is provided.
1102 */
1103
1104int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
1105{
1106	return -EOPNOTSUPP;
1107}
1108
1109int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
1110		    int len, int flags)
1111{
1112	return -EOPNOTSUPP;
1113}
1114
1115int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
1116{
1117	return -EOPNOTSUPP;
1118}
1119
1120int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
1121{
1122	return -EOPNOTSUPP;
1123}
1124
1125int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
1126		    int *len, int peer)
1127{
1128	return -EOPNOTSUPP;
1129}
1130
1131unsigned int sock_no_poll(struct file * file, struct socket *sock, poll_table *pt)
1132{
1133	return 0;
1134}
1135
1136int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1137{
1138	return -EOPNOTSUPP;
1139}
1140
1141int sock_no_listen(struct socket *sock, int backlog)
1142{
1143	return -EOPNOTSUPP;
1144}
1145
1146int sock_no_shutdown(struct socket *sock, int how)
1147{
1148	return -EOPNOTSUPP;
1149}
1150
1151int sock_no_setsockopt(struct socket *sock, int level, int optname,
1152		    char __user *optval, int optlen)
1153{
1154	return -EOPNOTSUPP;
1155}
1156
1157int sock_no_getsockopt(struct socket *sock, int level, int optname,
1158		    char __user *optval, int __user *optlen)
1159{
1160	return -EOPNOTSUPP;
1161}
1162
1163int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1164		    size_t len)
1165{
1166	return -EOPNOTSUPP;
1167}
1168
1169int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
1170		    size_t len, int flags)
1171{
1172	return -EOPNOTSUPP;
1173}
1174
1175int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
1176{
1177	/* Mirror missing mmap method error code */
1178	return -ENODEV;
1179}
1180
1181ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
1182{
1183	ssize_t res;
1184	struct msghdr msg = {.msg_flags = flags};
1185	struct kvec iov;
1186	char *kaddr = kmap(page);
1187	iov.iov_base = kaddr + offset;
1188	iov.iov_len = size;
1189	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
1190	kunmap(page);
1191	return res;
1192}
1193
1194/*
1195 *	Default Socket Callbacks
1196 */
1197
1198static void sock_def_wakeup(struct sock *sk)
1199{
1200	read_lock(&sk->sk_callback_lock);
1201	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1202		wake_up_interruptible_all(sk->sk_sleep);
1203	read_unlock(&sk->sk_callback_lock);
1204}
1205
1206static void sock_def_error_report(struct sock *sk)
1207{
1208	read_lock(&sk->sk_callback_lock);
1209	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1210		wake_up_interruptible(sk->sk_sleep);
1211	sk_wake_async(sk,0,POLL_ERR);
1212	read_unlock(&sk->sk_callback_lock);
1213}
1214
1215static void sock_def_readable(struct sock *sk, int len)
1216{
1217	read_lock(&sk->sk_callback_lock);
1218	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1219		wake_up_interruptible(sk->sk_sleep);
1220	sk_wake_async(sk,1,POLL_IN);
1221	read_unlock(&sk->sk_callback_lock);
1222}
1223
1224static void sock_def_write_space(struct sock *sk)
1225{
1226	read_lock(&sk->sk_callback_lock);
1227
1228	/* Do not wake up a writer until he can make "significant"
1229	 * progress.  --DaveM
1230	 */
1231	if((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
1232		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
1233			wake_up_interruptible(sk->sk_sleep);
1234
1235		/* Should agree with poll, otherwise some programs break */
1236		if (sock_writeable(sk))
1237			sk_wake_async(sk, 2, POLL_OUT);
1238	}
1239
1240	read_unlock(&sk->sk_callback_lock);
1241}
1242
1243static void sock_def_destruct(struct sock *sk)
1244{
1245	kfree(sk->sk_protinfo);
1246}
1247
1248void sk_send_sigurg(struct sock *sk)
1249{
1250	if (sk->sk_socket && sk->sk_socket->file)
1251		if (send_sigurg(&sk->sk_socket->file->f_owner))
1252			sk_wake_async(sk, 3, POLL_PRI);
1253}
1254
1255void sk_reset_timer(struct sock *sk, struct timer_list* timer,
1256		    unsigned long expires)
1257{
1258	if (!mod_timer(timer, expires))
1259		sock_hold(sk);
1260}
1261
1262EXPORT_SYMBOL(sk_reset_timer);
1263
1264void sk_stop_timer(struct sock *sk, struct timer_list* timer)
1265{
1266	if (timer_pending(timer) && del_timer(timer))
1267		__sock_put(sk);
1268}
1269
1270EXPORT_SYMBOL(sk_stop_timer);
1271
1272void sock_init_data(struct socket *sock, struct sock *sk)
1273{
1274	skb_queue_head_init(&sk->sk_receive_queue);
1275	skb_queue_head_init(&sk->sk_write_queue);
1276	skb_queue_head_init(&sk->sk_error_queue);
1277
1278	sk->sk_send_head	=	NULL;
1279
1280	init_timer(&sk->sk_timer);
1281
1282	sk->sk_allocation	=	GFP_KERNEL;
1283	sk->sk_rcvbuf		=	sysctl_rmem_default;
1284	sk->sk_sndbuf		=	sysctl_wmem_default;
1285	sk->sk_state		=	TCP_CLOSE;
1286	sk->sk_socket		=	sock;
1287
1288	sock_set_flag(sk, SOCK_ZAPPED);
1289
1290	if(sock)
1291	{
1292		sk->sk_type	=	sock->type;
1293		sk->sk_sleep	=	&sock->wait;
1294		sock->sk	=	sk;
1295	} else
1296		sk->sk_sleep	=	NULL;
1297
1298	rwlock_init(&sk->sk_dst_lock);
1299	rwlock_init(&sk->sk_callback_lock);
1300
1301	sk->sk_state_change	=	sock_def_wakeup;
1302	sk->sk_data_ready	=	sock_def_readable;
1303	sk->sk_write_space	=	sock_def_write_space;
1304	sk->sk_error_report	=	sock_def_error_report;
1305	sk->sk_destruct		=	sock_def_destruct;
1306
1307	sk->sk_sndmsg_page	=	NULL;
1308	sk->sk_sndmsg_off	=	0;
1309
1310	sk->sk_peercred.pid 	=	0;
1311	sk->sk_peercred.uid	=	-1;
1312	sk->sk_peercred.gid	=	-1;
1313	sk->sk_write_pending	=	0;
1314	sk->sk_rcvlowat		=	1;
1315	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
1316	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
1317
1318	sk->sk_stamp.tv_sec     = -1L;
1319	sk->sk_stamp.tv_usec    = -1L;
1320
1321	atomic_set(&sk->sk_refcnt, 1);
1322}
1323
1324void fastcall lock_sock(struct sock *sk)
1325{
1326	might_sleep();
1327	spin_lock_bh(&(sk->sk_lock.slock));
1328	if (sk->sk_lock.owner)
1329		__lock_sock(sk);
1330	sk->sk_lock.owner = (void *)1;
1331	spin_unlock_bh(&(sk->sk_lock.slock));
1332}
1333
1334EXPORT_SYMBOL(lock_sock);
1335
1336void fastcall release_sock(struct sock *sk)
1337{
1338	spin_lock_bh(&(sk->sk_lock.slock));
1339	if (sk->sk_backlog.tail)
1340		__release_sock(sk);
1341	sk->sk_lock.owner = NULL;
1342        if (waitqueue_active(&(sk->sk_lock.wq)))
1343		wake_up(&(sk->sk_lock.wq));
1344	spin_unlock_bh(&(sk->sk_lock.slock));
1345}
1346EXPORT_SYMBOL(release_sock);
1347
1348int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
1349{
1350	if (!sock_flag(sk, SOCK_TIMESTAMP))
1351		sock_enable_timestamp(sk);
1352	if (sk->sk_stamp.tv_sec == -1)
1353		return -ENOENT;
1354	if (sk->sk_stamp.tv_sec == 0)
1355		do_gettimeofday(&sk->sk_stamp);
1356	return copy_to_user(userstamp, &sk->sk_stamp, sizeof(struct timeval)) ?
1357		-EFAULT : 0;
1358}
1359EXPORT_SYMBOL(sock_get_timestamp);
1360
1361void sock_enable_timestamp(struct sock *sk)
1362{
1363	if (!sock_flag(sk, SOCK_TIMESTAMP)) {
1364		sock_set_flag(sk, SOCK_TIMESTAMP);
1365		net_enable_timestamp();
1366	}
1367}
1368EXPORT_SYMBOL(sock_enable_timestamp);
1369
1370/*
1371 *	Get a socket option on an socket.
1372 *
1373 *	FIX: POSIX 1003.1g is very ambiguous here. It states that
1374 *	asynchronous errors should be reported by getsockopt. We assume
1375 *	this means if you specify SO_ERROR (otherwise whats the point of it).
1376 */
1377int sock_common_getsockopt(struct socket *sock, int level, int optname,
1378			   char __user *optval, int __user *optlen)
1379{
1380	struct sock *sk = sock->sk;
1381
1382	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
1383}
1384
1385EXPORT_SYMBOL(sock_common_getsockopt);
1386
1387int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
1388			struct msghdr *msg, size_t size, int flags)
1389{
1390	struct sock *sk = sock->sk;
1391	int addr_len = 0;
1392	int err;
1393
1394	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
1395				   flags & ~MSG_DONTWAIT, &addr_len);
1396	if (err >= 0)
1397		msg->msg_namelen = addr_len;
1398	return err;
1399}
1400
1401EXPORT_SYMBOL(sock_common_recvmsg);
1402
1403/*
1404 *	Set socket options on an inet socket.
1405 */
1406int sock_common_setsockopt(struct socket *sock, int level, int optname,
1407			   char __user *optval, int optlen)
1408{
1409	struct sock *sk = sock->sk;
1410
1411	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
1412}
1413
1414EXPORT_SYMBOL(sock_common_setsockopt);
1415
1416void sk_common_release(struct sock *sk)
1417{
1418	if (sk->sk_prot->destroy)
1419		sk->sk_prot->destroy(sk);
1420
1421	/*
1422	 * Observation: when sock_common_release is called, processes have
1423	 * no access to socket. But net still has.
1424	 * Step one, detach it from networking:
1425	 *
1426	 * A. Remove from hash tables.
1427	 */
1428
1429	sk->sk_prot->unhash(sk);
1430
1431	/*
1432	 * In this point socket cannot receive new packets, but it is possible
1433	 * that some packets are in flight because some CPU runs receiver and
1434	 * did hash table lookup before we unhashed socket. They will achieve
1435	 * receive queue and will be purged by socket destructor.
1436	 *
1437	 * Also we still have packets pending on receive queue and probably,
1438	 * our own packets waiting in device queues. sock_destroy will drain
1439	 * receive queue, but transmitted packets will delay socket destruction
1440	 * until the last reference will be released.
1441	 */
1442
1443	sock_orphan(sk);
1444
1445	xfrm_sk_free_policy(sk);
1446
1447	sk_refcnt_debug_release(sk);
1448	sock_put(sk);
1449}
1450
1451EXPORT_SYMBOL(sk_common_release);
1452
1453static DEFINE_RWLOCK(proto_list_lock);
1454static LIST_HEAD(proto_list);
1455
1456int proto_register(struct proto *prot, int alloc_slab)
1457{
1458	char *request_sock_slab_name = NULL;
1459	char *timewait_sock_slab_name;
1460	int rc = -ENOBUFS;
1461
1462	if (alloc_slab) {
1463		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
1464					       SLAB_HWCACHE_ALIGN, NULL, NULL);
1465
1466		if (prot->slab == NULL) {
1467			printk(KERN_CRIT "%s: Can't create sock SLAB cache!\n",
1468			       prot->name);
1469			goto out;
1470		}
1471
1472		if (prot->rsk_prot != NULL) {
1473			static const char mask[] = "request_sock_%s";
1474
1475			request_sock_slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
1476			if (request_sock_slab_name == NULL)
1477				goto out_free_sock_slab;
1478
1479			sprintf(request_sock_slab_name, mask, prot->name);
1480			prot->rsk_prot->slab = kmem_cache_create(request_sock_slab_name,
1481								 prot->rsk_prot->obj_size, 0,
1482								 SLAB_HWCACHE_ALIGN, NULL, NULL);
1483
1484			if (prot->rsk_prot->slab == NULL) {
1485				printk(KERN_CRIT "%s: Can't create request sock SLAB cache!\n",
1486				       prot->name);
1487				goto out_free_request_sock_slab_name;
1488			}
1489		}
1490
1491		if (prot->twsk_prot != NULL) {
1492			static const char mask[] = "tw_sock_%s";
1493
1494			timewait_sock_slab_name = kmalloc(strlen(prot->name) + sizeof(mask) - 1, GFP_KERNEL);
1495
1496			if (timewait_sock_slab_name == NULL)
1497				goto out_free_request_sock_slab;
1498
1499			sprintf(timewait_sock_slab_name, mask, prot->name);
1500			prot->twsk_prot->twsk_slab =
1501				kmem_cache_create(timewait_sock_slab_name,
1502						  prot->twsk_prot->twsk_obj_size,
1503						  0, SLAB_HWCACHE_ALIGN,
1504						  NULL, NULL);
1505			if (prot->twsk_prot->twsk_slab == NULL)
1506				goto out_free_timewait_sock_slab_name;
1507		}
1508	}
1509
1510	write_lock(&proto_list_lock);
1511	list_add(&prot->node, &proto_list);
1512	write_unlock(&proto_list_lock);
1513	rc = 0;
1514out:
1515	return rc;
1516out_free_timewait_sock_slab_name:
1517	kfree(timewait_sock_slab_name);
1518out_free_request_sock_slab:
1519	if (prot->rsk_prot && prot->rsk_prot->slab) {
1520		kmem_cache_destroy(prot->rsk_prot->slab);
1521		prot->rsk_prot->slab = NULL;
1522	}
1523out_free_request_sock_slab_name:
1524	kfree(request_sock_slab_name);
1525out_free_sock_slab:
1526	kmem_cache_destroy(prot->slab);
1527	prot->slab = NULL;
1528	goto out;
1529}
1530
1531EXPORT_SYMBOL(proto_register);
1532
1533void proto_unregister(struct proto *prot)
1534{
1535	write_lock(&proto_list_lock);
1536	list_del(&prot->node);
1537	write_unlock(&proto_list_lock);
1538
1539	if (prot->slab != NULL) {
1540		kmem_cache_destroy(prot->slab);
1541		prot->slab = NULL;
1542	}
1543
1544	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
1545		const char *name = kmem_cache_name(prot->rsk_prot->slab);
1546
1547		kmem_cache_destroy(prot->rsk_prot->slab);
1548		kfree(name);
1549		prot->rsk_prot->slab = NULL;
1550	}
1551
1552	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
1553		const char *name = kmem_cache_name(prot->twsk_prot->twsk_slab);
1554
1555		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
1556		kfree(name);
1557		prot->twsk_prot->twsk_slab = NULL;
1558	}
1559}
1560
1561EXPORT_SYMBOL(proto_unregister);
1562
1563#ifdef CONFIG_PROC_FS
1564static inline struct proto *__proto_head(void)
1565{
1566	return list_entry(proto_list.next, struct proto, node);
1567}
1568
1569static inline struct proto *proto_head(void)
1570{
1571	return list_empty(&proto_list) ? NULL : __proto_head();
1572}
1573
1574static inline struct proto *proto_next(struct proto *proto)
1575{
1576	return proto->node.next == &proto_list ? NULL :
1577		list_entry(proto->node.next, struct proto, node);
1578}
1579
1580static inline struct proto *proto_get_idx(loff_t pos)
1581{
1582	struct proto *proto;
1583	loff_t i = 0;
1584
1585	list_for_each_entry(proto, &proto_list, node)
1586		if (i++ == pos)
1587			goto out;
1588
1589	proto = NULL;
1590out:
1591	return proto;
1592}
1593
1594static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
1595{
1596	read_lock(&proto_list_lock);
1597	return *pos ? proto_get_idx(*pos - 1) : SEQ_START_TOKEN;
1598}
1599
1600static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1601{
1602	++*pos;
1603	return v == SEQ_START_TOKEN ? proto_head() : proto_next(v);
1604}
1605
1606static void proto_seq_stop(struct seq_file *seq, void *v)
1607{
1608	read_unlock(&proto_list_lock);
1609}
1610
1611static char proto_method_implemented(const void *method)
1612{
1613	return method == NULL ? 'n' : 'y';
1614}
1615
1616static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
1617{
1618	seq_printf(seq, "%-9s %4u %6d  %6d   %-3s %6u   %-3s  %-10s "
1619			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
1620		   proto->name,
1621		   proto->obj_size,
1622		   proto->sockets_allocated != NULL ? atomic_read(proto->sockets_allocated) : -1,
1623		   proto->memory_allocated != NULL ? atomic_read(proto->memory_allocated) : -1,
1624		   proto->memory_pressure != NULL ? *proto->memory_pressure ? "yes" : "no" : "NI",
1625		   proto->max_header,
1626		   proto->slab == NULL ? "no" : "yes",
1627		   module_name(proto->owner),
1628		   proto_method_implemented(proto->close),
1629		   proto_method_implemented(proto->connect),
1630		   proto_method_implemented(proto->disconnect),
1631		   proto_method_implemented(proto->accept),
1632		   proto_method_implemented(proto->ioctl),
1633		   proto_method_implemented(proto->init),
1634		   proto_method_implemented(proto->destroy),
1635		   proto_method_implemented(proto->shutdown),
1636		   proto_method_implemented(proto->setsockopt),
1637		   proto_method_implemented(proto->getsockopt),
1638		   proto_method_implemented(proto->sendmsg),
1639		   proto_method_implemented(proto->recvmsg),
1640		   proto_method_implemented(proto->sendpage),
1641		   proto_method_implemented(proto->bind),
1642		   proto_method_implemented(proto->backlog_rcv),
1643		   proto_method_implemented(proto->hash),
1644		   proto_method_implemented(proto->unhash),
1645		   proto_method_implemented(proto->get_port),
1646		   proto_method_implemented(proto->enter_memory_pressure));
1647}
1648
1649static int proto_seq_show(struct seq_file *seq, void *v)
1650{
1651	if (v == SEQ_START_TOKEN)
1652		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
1653			   "protocol",
1654			   "size",
1655			   "sockets",
1656			   "memory",
1657			   "press",
1658			   "maxhdr",
1659			   "slab",
1660			   "module",
1661			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
1662	else
1663		proto_seq_printf(seq, v);
1664	return 0;
1665}
1666
1667static struct seq_operations proto_seq_ops = {
1668	.start  = proto_seq_start,
1669	.next   = proto_seq_next,
1670	.stop   = proto_seq_stop,
1671	.show   = proto_seq_show,
1672};
1673
1674static int proto_seq_open(struct inode *inode, struct file *file)
1675{
1676	return seq_open(file, &proto_seq_ops);
1677}
1678
1679static struct file_operations proto_seq_fops = {
1680	.owner		= THIS_MODULE,
1681	.open		= proto_seq_open,
1682	.read		= seq_read,
1683	.llseek		= seq_lseek,
1684	.release	= seq_release,
1685};
1686
1687static int __init proto_init(void)
1688{
1689	/* register /proc/net/protocols */
1690	return proc_net_fops_create("protocols", S_IRUGO, &proto_seq_fops) == NULL ? -ENOBUFS : 0;
1691}
1692
1693subsys_initcall(proto_init);
1694
1695#endif /* PROC_FS */
1696
1697EXPORT_SYMBOL(sk_alloc);
1698EXPORT_SYMBOL(sk_free);
1699EXPORT_SYMBOL(sk_send_sigurg);
1700EXPORT_SYMBOL(sock_alloc_send_skb);
1701EXPORT_SYMBOL(sock_init_data);
1702EXPORT_SYMBOL(sock_kfree_s);
1703EXPORT_SYMBOL(sock_kmalloc);
1704EXPORT_SYMBOL(sock_no_accept);
1705EXPORT_SYMBOL(sock_no_bind);
1706EXPORT_SYMBOL(sock_no_connect);
1707EXPORT_SYMBOL(sock_no_getname);
1708EXPORT_SYMBOL(sock_no_getsockopt);
1709EXPORT_SYMBOL(sock_no_ioctl);
1710EXPORT_SYMBOL(sock_no_listen);
1711EXPORT_SYMBOL(sock_no_mmap);
1712EXPORT_SYMBOL(sock_no_poll);
1713EXPORT_SYMBOL(sock_no_recvmsg);
1714EXPORT_SYMBOL(sock_no_sendmsg);
1715EXPORT_SYMBOL(sock_no_sendpage);
1716EXPORT_SYMBOL(sock_no_setsockopt);
1717EXPORT_SYMBOL(sock_no_shutdown);
1718EXPORT_SYMBOL(sock_no_socketpair);
1719EXPORT_SYMBOL(sock_rfree);
1720EXPORT_SYMBOL(sock_setsockopt);
1721EXPORT_SYMBOL(sock_wfree);
1722EXPORT_SYMBOL(sock_wmalloc);
1723EXPORT_SYMBOL(sock_i_uid);
1724EXPORT_SYMBOL(sock_i_ino);
1725EXPORT_SYMBOL(sysctl_optmem_max);
1726#ifdef CONFIG_SYSCTL
1727EXPORT_SYMBOL(sysctl_rmem_max);
1728EXPORT_SYMBOL(sysctl_wmem_max);
1729#endif
1730