af_inet.c revision d83d8461f902c672bc1bd8fbc6a94e19f092da97 
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 *		PF_INET protocol family socket handler.
7 *
8 * Version:	$Id: af_inet.c,v 1.137 2002/02/01 22:01:03 davem Exp $
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 * Changes (see also sock.c)
16 *
17 *		piggy,
18 *		Karl Knutson	:	Socket protocol table
19 *		A.N.Kuznetsov	:	Socket death error in accept().
20 *		John Richardson :	Fix non blocking error in connect()
21 *					so sockets that fail to connect
22 *					don't return -EINPROGRESS.
23 *		Alan Cox	:	Asynchronous I/O support
24 *		Alan Cox	:	Keep correct socket pointer on sock
25 *					structures
26 *					when accept() ed
27 *		Alan Cox	:	Semantics of SO_LINGER aren't state
28 *					moved to close when you look carefully.
29 *					With this fixed and the accept bug fixed
30 *					some RPC stuff seems happier.
31 *		Niibe Yutaka	:	4.4BSD style write async I/O
32 *		Alan Cox,
33 *		Tony Gale 	:	Fixed reuse semantics.
34 *		Alan Cox	:	bind() shouldn't abort existing but dead
35 *					sockets. Stops FTP netin:.. I hope.
36 *		Alan Cox	:	bind() works correctly for RAW sockets.
37 *					Note that FreeBSD at least was broken
38 *					in this respect so be careful with
39 *					compatibility tests...
40 *		Alan Cox	:	routing cache support
41 *		Alan Cox	:	memzero the socket structure for
42 *					compactness.
43 *		Matt Day	:	nonblock connect error handler
44 *		Alan Cox	:	Allow large numbers of pending sockets
45 *					(eg for big web sites), but only if
46 *					specifically application requested.
47 *		Alan Cox	:	New buffering throughout IP. Used
48 *					dumbly.
49 *		Alan Cox	:	New buffering now used smartly.
50 *		Alan Cox	:	BSD rather than common sense
51 *					interpretation of listen.
52 *		Germano Caronni	:	Assorted small races.
53 *		Alan Cox	:	sendmsg/recvmsg basic support.
54 *		Alan Cox	:	Only sendmsg/recvmsg now supported.
55 *		Alan Cox	:	Locked down bind (see security list).
56 *		Alan Cox	:	Loosened bind a little.
57 *		Mike McLagan	:	ADD/DEL DLCI Ioctls
58 *	Willy Konynenberg	:	Transparent proxying support.
59 *		David S. Miller	:	New socket lookup architecture.
60 *					Some other random speedups.
61 *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
62 *		Andi Kleen	:	Fix inet_stream_connect TCP race.
63 *
64 *		This program is free software; you can redistribute it and/or
65 *		modify it under the terms of the GNU General Public License
66 *		as published by the Free Software Foundation; either version
67 *		2 of the License, or (at your option) any later version.
68 */
69
70#include <linux/config.h>
71#include <linux/errno.h>
72#include <linux/types.h>
73#include <linux/socket.h>
74#include <linux/in.h>
75#include <linux/kernel.h>
76#include <linux/module.h>
77#include <linux/sched.h>
78#include <linux/timer.h>
79#include <linux/string.h>
80#include <linux/sockios.h>
81#include <linux/net.h>
82#include <linux/fcntl.h>
83#include <linux/mm.h>
84#include <linux/interrupt.h>
85#include <linux/stat.h>
86#include <linux/init.h>
87#include <linux/poll.h>
88#include <linux/netfilter_ipv4.h>
89
90#include <asm/uaccess.h>
91#include <asm/system.h>
92
93#include <linux/smp_lock.h>
94#include <linux/inet.h>
95#include <linux/igmp.h>
96#include <linux/netdevice.h>
97#include <net/ip.h>
98#include <net/protocol.h>
99#include <net/arp.h>
100#include <net/route.h>
101#include <net/ip_fib.h>
102#include <net/inet_connection_sock.h>
103#include <net/tcp.h>
104#include <net/udp.h>
105#include <linux/skbuff.h>
106#include <net/sock.h>
107#include <net/raw.h>
108#include <net/icmp.h>
109#include <net/ipip.h>
110#include <net/inet_common.h>
111#include <net/xfrm.h>
112#ifdef CONFIG_IP_MROUTE
113#include <linux/mroute.h>
114#endif
115
116DEFINE_SNMP_STAT(struct linux_mib, net_statistics) __read_mostly;
117
118extern void ip_mc_drop_socket(struct sock *sk);
119
120/* The inetsw table contains everything that inet_create needs to
121 * build a new socket.
122 */
123static struct list_head inetsw[SOCK_MAX];
124static DEFINE_SPINLOCK(inetsw_lock);
125
126/* New destruction routine */
127
128void inet_sock_destruct(struct sock *sk)
129{
130	struct inet_sock *inet = inet_sk(sk);
131
132	__skb_queue_purge(&sk->sk_receive_queue);
133	__skb_queue_purge(&sk->sk_error_queue);
134
135	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
136		printk("Attempt to release TCP socket in state %d %p\n",
137		       sk->sk_state, sk);
138		return;
139	}
140	if (!sock_flag(sk, SOCK_DEAD)) {
141		printk("Attempt to release alive inet socket %p\n", sk);
142		return;
143	}
144
145	BUG_TRAP(!atomic_read(&sk->sk_rmem_alloc));
146	BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
147	BUG_TRAP(!sk->sk_wmem_queued);
148	BUG_TRAP(!sk->sk_forward_alloc);
149
150	kfree(inet->opt);
151	dst_release(sk->sk_dst_cache);
152	sk_refcnt_debug_dec(sk);
153}
154
155/*
156 *	The routines beyond this point handle the behaviour of an AF_INET
157 *	socket object. Mostly it punts to the subprotocols of IP to do
158 *	the work.
159 */
160
161/*
162 *	Automatically bind an unbound socket.
163 */
164
165static int inet_autobind(struct sock *sk)
166{
167	struct inet_sock *inet;
168	/* We may need to bind the socket. */
169	lock_sock(sk);
170	inet = inet_sk(sk);
171	if (!inet->num) {
172		if (sk->sk_prot->get_port(sk, 0)) {
173			release_sock(sk);
174			return -EAGAIN;
175		}
176		inet->sport = htons(inet->num);
177	}
178	release_sock(sk);
179	return 0;
180}
181
182/*
183 *	Move a socket into listening state.
184 */
185int inet_listen(struct socket *sock, int backlog)
186{
187	struct sock *sk = sock->sk;
188	unsigned char old_state;
189	int err;
190
191	lock_sock(sk);
192
193	err = -EINVAL;
194	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
195		goto out;
196
197	old_state = sk->sk_state;
198	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
199		goto out;
200
201	/* Really, if the socket is already in listen state
202	 * we can only allow the backlog to be adjusted.
203	 */
204	if (old_state != TCP_LISTEN) {
205		err = inet_csk_listen_start(sk, TCP_SYNQ_HSIZE);
206		if (err)
207			goto out;
208	}
209	sk->sk_max_ack_backlog = backlog;
210	err = 0;
211
212out:
213	release_sock(sk);
214	return err;
215}
216
217/*
218 *	Create an inet socket.
219 */
220
221static int inet_create(struct socket *sock, int protocol)
222{
223	struct sock *sk;
224	struct list_head *p;
225	struct inet_protosw *answer;
226	struct inet_sock *inet;
227	struct proto *answer_prot;
228	unsigned char answer_flags;
229	char answer_no_check;
230	int try_loading_module = 0;
231	int err;
232
233	sock->state = SS_UNCONNECTED;
234
235	/* Look for the requested type/protocol pair. */
236	answer = NULL;
237lookup_protocol:
238	err = -ESOCKTNOSUPPORT;
239	rcu_read_lock();
240	list_for_each_rcu(p, &inetsw[sock->type]) {
241		answer = list_entry(p, struct inet_protosw, list);
242
243		/* Check the non-wild match. */
244		if (protocol == answer->protocol) {
245			if (protocol != IPPROTO_IP)
246				break;
247		} else {
248			/* Check for the two wild cases. */
249			if (IPPROTO_IP == protocol) {
250				protocol = answer->protocol;
251				break;
252			}
253			if (IPPROTO_IP == answer->protocol)
254				break;
255		}
256		err = -EPROTONOSUPPORT;
257		answer = NULL;
258	}
259
260	if (unlikely(answer == NULL)) {
261		if (try_loading_module < 2) {
262			rcu_read_unlock();
263			/*
264			 * Be more specific, e.g. net-pf-2-proto-132-type-1
265			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
266			 */
267			if (++try_loading_module == 1)
268				request_module("net-pf-%d-proto-%d-type-%d",
269					       PF_INET, protocol, sock->type);
270			/*
271			 * Fall back to generic, e.g. net-pf-2-proto-132
272			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
273			 */
274			else
275				request_module("net-pf-%d-proto-%d",
276					       PF_INET, protocol);
277			goto lookup_protocol;
278		} else
279			goto out_rcu_unlock;
280	}
281
282	err = -EPERM;
283	if (answer->capability > 0 && !capable(answer->capability))
284		goto out_rcu_unlock;
285
286	sock->ops = answer->ops;
287	answer_prot = answer->prot;
288	answer_no_check = answer->no_check;
289	answer_flags = answer->flags;
290	rcu_read_unlock();
291
292	BUG_TRAP(answer_prot->slab != NULL);
293
294	err = -ENOBUFS;
295	sk = sk_alloc(PF_INET, GFP_KERNEL, answer_prot, 1);
296	if (sk == NULL)
297		goto out;
298
299	err = 0;
300	sk->sk_no_check = answer_no_check;
301	if (INET_PROTOSW_REUSE & answer_flags)
302		sk->sk_reuse = 1;
303
304	inet = inet_sk(sk);
305	inet->is_icsk = INET_PROTOSW_ICSK & answer_flags;
306
307	if (SOCK_RAW == sock->type) {
308		inet->num = protocol;
309		if (IPPROTO_RAW == protocol)
310			inet->hdrincl = 1;
311	}
312
313	if (ipv4_config.no_pmtu_disc)
314		inet->pmtudisc = IP_PMTUDISC_DONT;
315	else
316		inet->pmtudisc = IP_PMTUDISC_WANT;
317
318	inet->id = 0;
319
320	sock_init_data(sock, sk);
321
322	sk->sk_destruct	   = inet_sock_destruct;
323	sk->sk_family	   = PF_INET;
324	sk->sk_protocol	   = protocol;
325	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
326
327	inet->uc_ttl	= -1;
328	inet->mc_loop	= 1;
329	inet->mc_ttl	= 1;
330	inet->mc_index	= 0;
331	inet->mc_list	= NULL;
332
333	sk_refcnt_debug_inc(sk);
334
335	if (inet->num) {
336		/* It assumes that any protocol which allows
337		 * the user to assign a number at socket
338		 * creation time automatically
339		 * shares.
340		 */
341		inet->sport = htons(inet->num);
342		/* Add to protocol hash chains. */
343		sk->sk_prot->hash(sk);
344	}
345
346	if (sk->sk_prot->init) {
347		err = sk->sk_prot->init(sk);
348		if (err)
349			sk_common_release(sk);
350	}
351out:
352	return err;
353out_rcu_unlock:
354	rcu_read_unlock();
355	goto out;
356}
357
358
359/*
360 *	The peer socket should always be NULL (or else). When we call this
361 *	function we are destroying the object and from then on nobody
362 *	should refer to it.
363 */
364int inet_release(struct socket *sock)
365{
366	struct sock *sk = sock->sk;
367
368	if (sk) {
369		long timeout;
370
371		/* Applications forget to leave groups before exiting */
372		ip_mc_drop_socket(sk);
373
374		/* If linger is set, we don't return until the close
375		 * is complete.  Otherwise we return immediately. The
376		 * actually closing is done the same either way.
377		 *
378		 * If the close is due to the process exiting, we never
379		 * linger..
380		 */
381		timeout = 0;
382		if (sock_flag(sk, SOCK_LINGER) &&
383		    !(current->flags & PF_EXITING))
384			timeout = sk->sk_lingertime;
385		sock->sk = NULL;
386		sk->sk_prot->close(sk, timeout);
387	}
388	return 0;
389}
390
391/* It is off by default, see below. */
392int sysctl_ip_nonlocal_bind;
393
394int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
395{
396	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
397	struct sock *sk = sock->sk;
398	struct inet_sock *inet = inet_sk(sk);
399	unsigned short snum;
400	int chk_addr_ret;
401	int err;
402
403	/* If the socket has its own bind function then use it. (RAW) */
404	if (sk->sk_prot->bind) {
405		err = sk->sk_prot->bind(sk, uaddr, addr_len);
406		goto out;
407	}
408	err = -EINVAL;
409	if (addr_len < sizeof(struct sockaddr_in))
410		goto out;
411
412	chk_addr_ret = inet_addr_type(addr->sin_addr.s_addr);
413
414	/* Not specified by any standard per-se, however it breaks too
415	 * many applications when removed.  It is unfortunate since
416	 * allowing applications to make a non-local bind solves
417	 * several problems with systems using dynamic addressing.
418	 * (ie. your servers still start up even if your ISDN link
419	 *  is temporarily down)
420	 */
421	err = -EADDRNOTAVAIL;
422	if (!sysctl_ip_nonlocal_bind &&
423	    !inet->freebind &&
424	    addr->sin_addr.s_addr != INADDR_ANY &&
425	    chk_addr_ret != RTN_LOCAL &&
426	    chk_addr_ret != RTN_MULTICAST &&
427	    chk_addr_ret != RTN_BROADCAST)
428		goto out;
429
430	snum = ntohs(addr->sin_port);
431	err = -EACCES;
432	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
433		goto out;
434
435	/*      We keep a pair of addresses. rcv_saddr is the one
436	 *      used by hash lookups, and saddr is used for transmit.
437	 *
438	 *      In the BSD API these are the same except where it
439	 *      would be illegal to use them (multicast/broadcast) in
440	 *      which case the sending device address is used.
441	 */
442	lock_sock(sk);
443
444	/* Check these errors (active socket, double bind). */
445	err = -EINVAL;
446	if (sk->sk_state != TCP_CLOSE || inet->num)
447		goto out_release_sock;
448
449	inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr;
450	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
451		inet->saddr = 0;  /* Use device */
452
453	/* Make sure we are allowed to bind here. */
454	if (sk->sk_prot->get_port(sk, snum)) {
455		inet->saddr = inet->rcv_saddr = 0;
456		err = -EADDRINUSE;
457		goto out_release_sock;
458	}
459
460	if (inet->rcv_saddr)
461		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
462	if (snum)
463		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
464	inet->sport = htons(inet->num);
465	inet->daddr = 0;
466	inet->dport = 0;
467	sk_dst_reset(sk);
468	err = 0;
469out_release_sock:
470	release_sock(sk);
471out:
472	return err;
473}
474
475int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
476		       int addr_len, int flags)
477{
478	struct sock *sk = sock->sk;
479
480	if (uaddr->sa_family == AF_UNSPEC)
481		return sk->sk_prot->disconnect(sk, flags);
482
483	if (!inet_sk(sk)->num && inet_autobind(sk))
484		return -EAGAIN;
485	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
486}
487
488static long inet_wait_for_connect(struct sock *sk, long timeo)
489{
490	DEFINE_WAIT(wait);
491
492	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
493
494	/* Basic assumption: if someone sets sk->sk_err, he _must_
495	 * change state of the socket from TCP_SYN_*.
496	 * Connect() does not allow to get error notifications
497	 * without closing the socket.
498	 */
499	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
500		release_sock(sk);
501		timeo = schedule_timeout(timeo);
502		lock_sock(sk);
503		if (signal_pending(current) || !timeo)
504			break;
505		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
506	}
507	finish_wait(sk->sk_sleep, &wait);
508	return timeo;
509}
510
511/*
512 *	Connect to a remote host. There is regrettably still a little
513 *	TCP 'magic' in here.
514 */
515int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
516			int addr_len, int flags)
517{
518	struct sock *sk = sock->sk;
519	int err;
520	long timeo;
521
522	lock_sock(sk);
523
524	if (uaddr->sa_family == AF_UNSPEC) {
525		err = sk->sk_prot->disconnect(sk, flags);
526		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
527		goto out;
528	}
529
530	switch (sock->state) {
531	default:
532		err = -EINVAL;
533		goto out;
534	case SS_CONNECTED:
535		err = -EISCONN;
536		goto out;
537	case SS_CONNECTING:
538		err = -EALREADY;
539		/* Fall out of switch with err, set for this state */
540		break;
541	case SS_UNCONNECTED:
542		err = -EISCONN;
543		if (sk->sk_state != TCP_CLOSE)
544			goto out;
545
546		err = sk->sk_prot->connect(sk, uaddr, addr_len);
547		if (err < 0)
548			goto out;
549
550  		sock->state = SS_CONNECTING;
551
552		/* Just entered SS_CONNECTING state; the only
553		 * difference is that return value in non-blocking
554		 * case is EINPROGRESS, rather than EALREADY.
555		 */
556		err = -EINPROGRESS;
557		break;
558	}
559
560	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
561
562	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
563		/* Error code is set above */
564		if (!timeo || !inet_wait_for_connect(sk, timeo))
565			goto out;
566
567		err = sock_intr_errno(timeo);
568		if (signal_pending(current))
569			goto out;
570	}
571
572	/* Connection was closed by RST, timeout, ICMP error
573	 * or another process disconnected us.
574	 */
575	if (sk->sk_state == TCP_CLOSE)
576		goto sock_error;
577
578	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
579	 * and error was received after socket entered established state.
580	 * Hence, it is handled normally after connect() return successfully.
581	 */
582
583	sock->state = SS_CONNECTED;
584	err = 0;
585out:
586	release_sock(sk);
587	return err;
588
589sock_error:
590	err = sock_error(sk) ? : -ECONNABORTED;
591	sock->state = SS_UNCONNECTED;
592	if (sk->sk_prot->disconnect(sk, flags))
593		sock->state = SS_DISCONNECTING;
594	goto out;
595}
596
597/*
598 *	Accept a pending connection. The TCP layer now gives BSD semantics.
599 */
600
601int inet_accept(struct socket *sock, struct socket *newsock, int flags)
602{
603	struct sock *sk1 = sock->sk;
604	int err = -EINVAL;
605	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
606
607	if (!sk2)
608		goto do_err;
609
610	lock_sock(sk2);
611
612	BUG_TRAP((1 << sk2->sk_state) &
613		 (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE));
614
615	sock_graft(sk2, newsock);
616
617	newsock->state = SS_CONNECTED;
618	err = 0;
619	release_sock(sk2);
620do_err:
621	return err;
622}
623
624
625/*
626 *	This does both peername and sockname.
627 */
628int inet_getname(struct socket *sock, struct sockaddr *uaddr,
629			int *uaddr_len, int peer)
630{
631	struct sock *sk		= sock->sk;
632	struct inet_sock *inet	= inet_sk(sk);
633	struct sockaddr_in *sin	= (struct sockaddr_in *)uaddr;
634
635	sin->sin_family = AF_INET;
636	if (peer) {
637		if (!inet->dport ||
638		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
639		     peer == 1))
640			return -ENOTCONN;
641		sin->sin_port = inet->dport;
642		sin->sin_addr.s_addr = inet->daddr;
643	} else {
644		__u32 addr = inet->rcv_saddr;
645		if (!addr)
646			addr = inet->saddr;
647		sin->sin_port = inet->sport;
648		sin->sin_addr.s_addr = addr;
649	}
650	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
651	*uaddr_len = sizeof(*sin);
652	return 0;
653}
654
655int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
656		 size_t size)
657{
658	struct sock *sk = sock->sk;
659
660	/* We may need to bind the socket. */
661	if (!inet_sk(sk)->num && inet_autobind(sk))
662		return -EAGAIN;
663
664	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
665}
666
667
668static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
669{
670	struct sock *sk = sock->sk;
671
672	/* We may need to bind the socket. */
673	if (!inet_sk(sk)->num && inet_autobind(sk))
674		return -EAGAIN;
675
676	if (sk->sk_prot->sendpage)
677		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
678	return sock_no_sendpage(sock, page, offset, size, flags);
679}
680
681
682int inet_shutdown(struct socket *sock, int how)
683{
684	struct sock *sk = sock->sk;
685	int err = 0;
686
687	/* This should really check to make sure
688	 * the socket is a TCP socket. (WHY AC...)
689	 */
690	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
691		       1->2 bit 2 snds.
692		       2->3 */
693	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
694		return -EINVAL;
695
696	lock_sock(sk);
697	if (sock->state == SS_CONNECTING) {
698		if ((1 << sk->sk_state) &
699		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
700			sock->state = SS_DISCONNECTING;
701		else
702			sock->state = SS_CONNECTED;
703	}
704
705	switch (sk->sk_state) {
706	case TCP_CLOSE:
707		err = -ENOTCONN;
708		/* Hack to wake up other listeners, who can poll for
709		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
710	default:
711		sk->sk_shutdown |= how;
712		if (sk->sk_prot->shutdown)
713			sk->sk_prot->shutdown(sk, how);
714		break;
715
716	/* Remaining two branches are temporary solution for missing
717	 * close() in multithreaded environment. It is _not_ a good idea,
718	 * but we have no choice until close() is repaired at VFS level.
719	 */
720	case TCP_LISTEN:
721		if (!(how & RCV_SHUTDOWN))
722			break;
723		/* Fall through */
724	case TCP_SYN_SENT:
725		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
726		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
727		break;
728	}
729
730	/* Wake up anyone sleeping in poll. */
731	sk->sk_state_change(sk);
732	release_sock(sk);
733	return err;
734}
735
736/*
737 *	ioctl() calls you can issue on an INET socket. Most of these are
738 *	device configuration and stuff and very rarely used. Some ioctls
739 *	pass on to the socket itself.
740 *
741 *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
742 *	loads the devconfigure module does its configuring and unloads it.
743 *	There's a good 20K of config code hanging around the kernel.
744 */
745
746int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
747{
748	struct sock *sk = sock->sk;
749	int err = 0;
750
751	switch (cmd) {
752		case SIOCGSTAMP:
753			err = sock_get_timestamp(sk, (struct timeval __user *)arg);
754			break;
755		case SIOCADDRT:
756		case SIOCDELRT:
757		case SIOCRTMSG:
758			err = ip_rt_ioctl(cmd, (void __user *)arg);
759			break;
760		case SIOCDARP:
761		case SIOCGARP:
762		case SIOCSARP:
763			err = arp_ioctl(cmd, (void __user *)arg);
764			break;
765		case SIOCGIFADDR:
766		case SIOCSIFADDR:
767		case SIOCGIFBRDADDR:
768		case SIOCSIFBRDADDR:
769		case SIOCGIFNETMASK:
770		case SIOCSIFNETMASK:
771		case SIOCGIFDSTADDR:
772		case SIOCSIFDSTADDR:
773		case SIOCSIFPFLAGS:
774		case SIOCGIFPFLAGS:
775		case SIOCSIFFLAGS:
776			err = devinet_ioctl(cmd, (void __user *)arg);
777			break;
778		default:
779			if (!sk->sk_prot->ioctl ||
780			    (err = sk->sk_prot->ioctl(sk, cmd, arg)) ==
781			    					-ENOIOCTLCMD)
782				err = dev_ioctl(cmd, (void __user *)arg);
783			break;
784	}
785	return err;
786}
787
788struct proto_ops inet_stream_ops = {
789	.family =	PF_INET,
790	.owner =	THIS_MODULE,
791	.release =	inet_release,
792	.bind =		inet_bind,
793	.connect =	inet_stream_connect,
794	.socketpair =	sock_no_socketpair,
795	.accept =	inet_accept,
796	.getname =	inet_getname,
797	.poll =		tcp_poll,
798	.ioctl =	inet_ioctl,
799	.listen =	inet_listen,
800	.shutdown =	inet_shutdown,
801	.setsockopt =	sock_common_setsockopt,
802	.getsockopt =	sock_common_getsockopt,
803	.sendmsg =	inet_sendmsg,
804	.recvmsg =	sock_common_recvmsg,
805	.mmap =		sock_no_mmap,
806	.sendpage =	tcp_sendpage
807};
808
809struct proto_ops inet_dgram_ops = {
810	.family =	PF_INET,
811	.owner =	THIS_MODULE,
812	.release =	inet_release,
813	.bind =		inet_bind,
814	.connect =	inet_dgram_connect,
815	.socketpair =	sock_no_socketpair,
816	.accept =	sock_no_accept,
817	.getname =	inet_getname,
818	.poll =		udp_poll,
819	.ioctl =	inet_ioctl,
820	.listen =	sock_no_listen,
821	.shutdown =	inet_shutdown,
822	.setsockopt =	sock_common_setsockopt,
823	.getsockopt =	sock_common_getsockopt,
824	.sendmsg =	inet_sendmsg,
825	.recvmsg =	sock_common_recvmsg,
826	.mmap =		sock_no_mmap,
827	.sendpage =	inet_sendpage,
828};
829
830/*
831 * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
832 * udp_poll
833 */
834static struct proto_ops inet_sockraw_ops = {
835	.family =	PF_INET,
836	.owner =	THIS_MODULE,
837	.release =	inet_release,
838	.bind =		inet_bind,
839	.connect =	inet_dgram_connect,
840	.socketpair =	sock_no_socketpair,
841	.accept =	sock_no_accept,
842	.getname =	inet_getname,
843	.poll =		datagram_poll,
844	.ioctl =	inet_ioctl,
845	.listen =	sock_no_listen,
846	.shutdown =	inet_shutdown,
847	.setsockopt =	sock_common_setsockopt,
848	.getsockopt =	sock_common_getsockopt,
849	.sendmsg =	inet_sendmsg,
850	.recvmsg =	sock_common_recvmsg,
851	.mmap =		sock_no_mmap,
852	.sendpage =	inet_sendpage,
853};
854
855static struct net_proto_family inet_family_ops = {
856	.family = PF_INET,
857	.create = inet_create,
858	.owner	= THIS_MODULE,
859};
860
861/* Upon startup we insert all the elements in inetsw_array[] into
862 * the linked list inetsw.
863 */
864static struct inet_protosw inetsw_array[] =
865{
866        {
867                .type =       SOCK_STREAM,
868                .protocol =   IPPROTO_TCP,
869                .prot =       &tcp_prot,
870                .ops =        &inet_stream_ops,
871                .capability = -1,
872                .no_check =   0,
873                .flags =      INET_PROTOSW_PERMANENT |
874			      INET_PROTOSW_ICSK,
875        },
876
877        {
878                .type =       SOCK_DGRAM,
879                .protocol =   IPPROTO_UDP,
880                .prot =       &udp_prot,
881                .ops =        &inet_dgram_ops,
882                .capability = -1,
883                .no_check =   UDP_CSUM_DEFAULT,
884                .flags =      INET_PROTOSW_PERMANENT,
885       },
886
887
888       {
889               .type =       SOCK_RAW,
890               .protocol =   IPPROTO_IP,	/* wild card */
891               .prot =       &raw_prot,
892               .ops =        &inet_sockraw_ops,
893               .capability = CAP_NET_RAW,
894               .no_check =   UDP_CSUM_DEFAULT,
895               .flags =      INET_PROTOSW_REUSE,
896       }
897};
898
899#define INETSW_ARRAY_LEN (sizeof(inetsw_array) / sizeof(struct inet_protosw))
900
901void inet_register_protosw(struct inet_protosw *p)
902{
903	struct list_head *lh;
904	struct inet_protosw *answer;
905	int protocol = p->protocol;
906	struct list_head *last_perm;
907
908	spin_lock_bh(&inetsw_lock);
909
910	if (p->type >= SOCK_MAX)
911		goto out_illegal;
912
913	/* If we are trying to override a permanent protocol, bail. */
914	answer = NULL;
915	last_perm = &inetsw[p->type];
916	list_for_each(lh, &inetsw[p->type]) {
917		answer = list_entry(lh, struct inet_protosw, list);
918
919		/* Check only the non-wild match. */
920		if (INET_PROTOSW_PERMANENT & answer->flags) {
921			if (protocol == answer->protocol)
922				break;
923			last_perm = lh;
924		}
925
926		answer = NULL;
927	}
928	if (answer)
929		goto out_permanent;
930
931	/* Add the new entry after the last permanent entry if any, so that
932	 * the new entry does not override a permanent entry when matched with
933	 * a wild-card protocol. But it is allowed to override any existing
934	 * non-permanent entry.  This means that when we remove this entry, the
935	 * system automatically returns to the old behavior.
936	 */
937	list_add_rcu(&p->list, last_perm);
938out:
939	spin_unlock_bh(&inetsw_lock);
940
941	synchronize_net();
942
943	return;
944
945out_permanent:
946	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
947	       protocol);
948	goto out;
949
950out_illegal:
951	printk(KERN_ERR
952	       "Ignoring attempt to register invalid socket type %d.\n",
953	       p->type);
954	goto out;
955}
956
957void inet_unregister_protosw(struct inet_protosw *p)
958{
959	if (INET_PROTOSW_PERMANENT & p->flags) {
960		printk(KERN_ERR
961		       "Attempt to unregister permanent protocol %d.\n",
962		       p->protocol);
963	} else {
964		spin_lock_bh(&inetsw_lock);
965		list_del_rcu(&p->list);
966		spin_unlock_bh(&inetsw_lock);
967
968		synchronize_net();
969	}
970}
971
972/*
973 *      Shall we try to damage output packets if routing dev changes?
974 */
975
976int sysctl_ip_dynaddr;
977
978static int inet_sk_reselect_saddr(struct sock *sk)
979{
980	struct inet_sock *inet = inet_sk(sk);
981	int err;
982	struct rtable *rt;
983	__u32 old_saddr = inet->saddr;
984	__u32 new_saddr;
985	__u32 daddr = inet->daddr;
986
987	if (inet->opt && inet->opt->srr)
988		daddr = inet->opt->faddr;
989
990	/* Query new route. */
991	err = ip_route_connect(&rt, daddr, 0,
992			       RT_CONN_FLAGS(sk),
993			       sk->sk_bound_dev_if,
994			       sk->sk_protocol,
995			       inet->sport, inet->dport, sk);
996	if (err)
997		return err;
998
999	sk_setup_caps(sk, &rt->u.dst);
1000
1001	new_saddr = rt->rt_src;
1002
1003	if (new_saddr == old_saddr)
1004		return 0;
1005
1006	if (sysctl_ip_dynaddr > 1) {
1007		printk(KERN_INFO "%s(): shifting inet->"
1008				 "saddr from %d.%d.%d.%d to %d.%d.%d.%d\n",
1009		       __FUNCTION__,
1010		       NIPQUAD(old_saddr),
1011		       NIPQUAD(new_saddr));
1012	}
1013
1014	inet->saddr = inet->rcv_saddr = new_saddr;
1015
1016	/*
1017	 * XXX The only one ugly spot where we need to
1018	 * XXX really change the sockets identity after
1019	 * XXX it has entered the hashes. -DaveM
1020	 *
1021	 * Besides that, it does not check for connection
1022	 * uniqueness. Wait for troubles.
1023	 */
1024	__sk_prot_rehash(sk);
1025	return 0;
1026}
1027
1028int inet_sk_rebuild_header(struct sock *sk)
1029{
1030	struct inet_sock *inet = inet_sk(sk);
1031	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1032	u32 daddr;
1033	int err;
1034
1035	/* Route is OK, nothing to do. */
1036	if (rt)
1037		return 0;
1038
1039	/* Reroute. */
1040	daddr = inet->daddr;
1041	if (inet->opt && inet->opt->srr)
1042		daddr = inet->opt->faddr;
1043{
1044	struct flowi fl = {
1045		.oif = sk->sk_bound_dev_if,
1046		.nl_u = {
1047			.ip4_u = {
1048				.daddr	= daddr,
1049				.saddr	= inet->saddr,
1050				.tos	= RT_CONN_FLAGS(sk),
1051			},
1052		},
1053		.proto = sk->sk_protocol,
1054		.uli_u = {
1055			.ports = {
1056				.sport = inet->sport,
1057				.dport = inet->dport,
1058			},
1059		},
1060	};
1061
1062	err = ip_route_output_flow(&rt, &fl, sk, 0);
1063}
1064	if (!err)
1065		sk_setup_caps(sk, &rt->u.dst);
1066	else {
1067		/* Routing failed... */
1068		sk->sk_route_caps = 0;
1069		/*
1070		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1071		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1072		 */
1073		if (!sysctl_ip_dynaddr ||
1074		    sk->sk_state != TCP_SYN_SENT ||
1075		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1076		    (err = inet_sk_reselect_saddr(sk)) != 0)
1077			sk->sk_err_soft = -err;
1078	}
1079
1080	return err;
1081}
1082
1083EXPORT_SYMBOL(inet_sk_rebuild_header);
1084
1085#ifdef CONFIG_IP_MULTICAST
1086static struct net_protocol igmp_protocol = {
1087	.handler =	igmp_rcv,
1088};
1089#endif
1090
1091static struct net_protocol tcp_protocol = {
1092	.handler =	tcp_v4_rcv,
1093	.err_handler =	tcp_v4_err,
1094	.no_policy =	1,
1095};
1096
1097static struct net_protocol udp_protocol = {
1098	.handler =	udp_rcv,
1099	.err_handler =	udp_err,
1100	.no_policy =	1,
1101};
1102
1103static struct net_protocol icmp_protocol = {
1104	.handler =	icmp_rcv,
1105};
1106
1107static int __init init_ipv4_mibs(void)
1108{
1109	net_statistics[0] = alloc_percpu(struct linux_mib);
1110	net_statistics[1] = alloc_percpu(struct linux_mib);
1111	ip_statistics[0] = alloc_percpu(struct ipstats_mib);
1112	ip_statistics[1] = alloc_percpu(struct ipstats_mib);
1113	icmp_statistics[0] = alloc_percpu(struct icmp_mib);
1114	icmp_statistics[1] = alloc_percpu(struct icmp_mib);
1115	tcp_statistics[0] = alloc_percpu(struct tcp_mib);
1116	tcp_statistics[1] = alloc_percpu(struct tcp_mib);
1117	udp_statistics[0] = alloc_percpu(struct udp_mib);
1118	udp_statistics[1] = alloc_percpu(struct udp_mib);
1119	if (!
1120	    (net_statistics[0] && net_statistics[1] && ip_statistics[0]
1121	     && ip_statistics[1] && tcp_statistics[0] && tcp_statistics[1]
1122	     && udp_statistics[0] && udp_statistics[1]))
1123		return -ENOMEM;
1124
1125	(void) tcp_mib_init();
1126
1127	return 0;
1128}
1129
1130static int ipv4_proc_init(void);
1131
1132/*
1133 *	IP protocol layer initialiser
1134 */
1135
1136static struct packet_type ip_packet_type = {
1137	.type = __constant_htons(ETH_P_IP),
1138	.func = ip_rcv,
1139};
1140
1141static int __init inet_init(void)
1142{
1143	struct sk_buff *dummy_skb;
1144	struct inet_protosw *q;
1145	struct list_head *r;
1146	int rc = -EINVAL;
1147
1148	if (sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb)) {
1149		printk(KERN_CRIT "%s: panic\n", __FUNCTION__);
1150		goto out;
1151	}
1152
1153	rc = proto_register(&tcp_prot, 1);
1154	if (rc)
1155		goto out;
1156
1157	rc = proto_register(&udp_prot, 1);
1158	if (rc)
1159		goto out_unregister_tcp_proto;
1160
1161	rc = proto_register(&raw_prot, 1);
1162	if (rc)
1163		goto out_unregister_udp_proto;
1164
1165	/*
1166	 *	Tell SOCKET that we are alive...
1167	 */
1168
1169  	(void)sock_register(&inet_family_ops);
1170
1171	/*
1172	 *	Add all the base protocols.
1173	 */
1174
1175	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1176		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1177	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1178		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1179	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1180		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1181#ifdef CONFIG_IP_MULTICAST
1182	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1183		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1184#endif
1185
1186	/* Register the socket-side information for inet_create. */
1187	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1188		INIT_LIST_HEAD(r);
1189
1190	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1191		inet_register_protosw(q);
1192
1193	/*
1194	 *	Set the ARP module up
1195	 */
1196
1197	arp_init();
1198
1199  	/*
1200  	 *	Set the IP module up
1201  	 */
1202
1203	ip_init();
1204
1205	tcp_v4_init(&inet_family_ops);
1206
1207	/* Setup TCP slab cache for open requests. */
1208	tcp_init();
1209
1210
1211	/*
1212	 *	Set the ICMP layer up
1213	 */
1214
1215	icmp_init(&inet_family_ops);
1216
1217	/*
1218	 *	Initialise the multicast router
1219	 */
1220#if defined(CONFIG_IP_MROUTE)
1221	ip_mr_init();
1222#endif
1223	/*
1224	 *	Initialise per-cpu ipv4 mibs
1225	 */
1226
1227	if(init_ipv4_mibs())
1228		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n"); ;
1229
1230	ipv4_proc_init();
1231
1232	ipfrag_init();
1233
1234	dev_add_pack(&ip_packet_type);
1235
1236	rc = 0;
1237out:
1238	return rc;
1239out_unregister_tcp_proto:
1240	proto_unregister(&tcp_prot);
1241out_unregister_udp_proto:
1242	proto_unregister(&udp_prot);
1243	goto out;
1244}
1245
1246module_init(inet_init);
1247
1248/* ------------------------------------------------------------------------ */
1249
1250#ifdef CONFIG_PROC_FS
1251static int __init ipv4_proc_init(void)
1252{
1253	int rc = 0;
1254
1255	if (raw_proc_init())
1256		goto out_raw;
1257	if (tcp4_proc_init())
1258		goto out_tcp;
1259	if (udp4_proc_init())
1260		goto out_udp;
1261	if (fib_proc_init())
1262		goto out_fib;
1263	if (ip_misc_proc_init())
1264		goto out_misc;
1265out:
1266	return rc;
1267out_misc:
1268	fib_proc_exit();
1269out_fib:
1270	udp4_proc_exit();
1271out_udp:
1272	tcp4_proc_exit();
1273out_tcp:
1274	raw_proc_exit();
1275out_raw:
1276	rc = -ENOMEM;
1277	goto out;
1278}
1279
1280#else /* CONFIG_PROC_FS */
1281static int __init ipv4_proc_init(void)
1282{
1283	return 0;
1284}
1285#endif /* CONFIG_PROC_FS */
1286
1287MODULE_ALIAS_NETPROTO(PF_INET);
1288
1289EXPORT_SYMBOL(inet_accept);
1290EXPORT_SYMBOL(inet_bind);
1291EXPORT_SYMBOL(inet_dgram_connect);
1292EXPORT_SYMBOL(inet_dgram_ops);
1293EXPORT_SYMBOL(inet_getname);
1294EXPORT_SYMBOL(inet_ioctl);
1295EXPORT_SYMBOL(inet_listen);
1296EXPORT_SYMBOL(inet_register_protosw);
1297EXPORT_SYMBOL(inet_release);
1298EXPORT_SYMBOL(inet_sendmsg);
1299EXPORT_SYMBOL(inet_shutdown);
1300EXPORT_SYMBOL(inet_sock_destruct);
1301EXPORT_SYMBOL(inet_stream_connect);
1302EXPORT_SYMBOL(inet_stream_ops);
1303EXPORT_SYMBOL(inet_unregister_protosw);
1304EXPORT_SYMBOL(net_statistics);
1305EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
1306