xref: /linux/net/ipv4/af_inet.c (revision 6ee738610f41b59733f63718f0bdbcba7d3a3f12)
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  * Authors:	Ross Biro
9  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10  *		Florian La Roche, <flla@stud.uni-sb.de>
11  *		Alan Cox, <A.Cox@swansea.ac.uk>
12  *
13  * Changes (see also sock.c)
14  *
15  *		piggy,
16  *		Karl Knutson	:	Socket protocol table
17  *		A.N.Kuznetsov	:	Socket death error in accept().
18  *		John Richardson :	Fix non blocking error in connect()
19  *					so sockets that fail to connect
20  *					don't return -EINPROGRESS.
21  *		Alan Cox	:	Asynchronous I/O support
22  *		Alan Cox	:	Keep correct socket pointer on sock
23  *					structures
24  *					when accept() ed
25  *		Alan Cox	:	Semantics of SO_LINGER aren't state
26  *					moved to close when you look carefully.
27  *					With this fixed and the accept bug fixed
28  *					some RPC stuff seems happier.
29  *		Niibe Yutaka	:	4.4BSD style write async I/O
30  *		Alan Cox,
31  *		Tony Gale 	:	Fixed reuse semantics.
32  *		Alan Cox	:	bind() shouldn't abort existing but dead
33  *					sockets. Stops FTP netin:.. I hope.
34  *		Alan Cox	:	bind() works correctly for RAW sockets.
35  *					Note that FreeBSD at least was broken
36  *					in this respect so be careful with
37  *					compatibility tests...
38  *		Alan Cox	:	routing cache support
39  *		Alan Cox	:	memzero the socket structure for
40  *					compactness.
41  *		Matt Day	:	nonblock connect error handler
42  *		Alan Cox	:	Allow large numbers of pending sockets
43  *					(eg for big web sites), but only if
44  *					specifically application requested.
45  *		Alan Cox	:	New buffering throughout IP. Used
46  *					dumbly.
47  *		Alan Cox	:	New buffering now used smartly.
48  *		Alan Cox	:	BSD rather than common sense
49  *					interpretation of listen.
50  *		Germano Caronni	:	Assorted small races.
51  *		Alan Cox	:	sendmsg/recvmsg basic support.
52  *		Alan Cox	:	Only sendmsg/recvmsg now supported.
53  *		Alan Cox	:	Locked down bind (see security list).
54  *		Alan Cox	:	Loosened bind a little.
55  *		Mike McLagan	:	ADD/DEL DLCI Ioctls
56  *	Willy Konynenberg	:	Transparent proxying support.
57  *		David S. Miller	:	New socket lookup architecture.
58  *					Some other random speedups.
59  *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
60  *		Andi Kleen	:	Fix inet_stream_connect TCP race.
61  *
62  *		This program is free software; you can redistribute it and/or
63  *		modify it under the terms of the GNU General Public License
64  *		as published by the Free Software Foundation; either version
65  *		2 of the License, or (at your option) any later version.
66  */
67 
68 #include <linux/err.h>
69 #include <linux/errno.h>
70 #include <linux/types.h>
71 #include <linux/socket.h>
72 #include <linux/in.h>
73 #include <linux/kernel.h>
74 #include <linux/module.h>
75 #include <linux/sched.h>
76 #include <linux/timer.h>
77 #include <linux/string.h>
78 #include <linux/sockios.h>
79 #include <linux/net.h>
80 #include <linux/capability.h>
81 #include <linux/fcntl.h>
82 #include <linux/mm.h>
83 #include <linux/interrupt.h>
84 #include <linux/stat.h>
85 #include <linux/init.h>
86 #include <linux/poll.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 
90 #include <asm/uaccess.h>
91 #include <asm/system.h>
92 
93 #include <linux/inet.h>
94 #include <linux/igmp.h>
95 #include <linux/inetdevice.h>
96 #include <linux/netdevice.h>
97 #include <net/checksum.h>
98 #include <net/ip.h>
99 #include <net/protocol.h>
100 #include <net/arp.h>
101 #include <net/route.h>
102 #include <net/ip_fib.h>
103 #include <net/inet_connection_sock.h>
104 #include <net/tcp.h>
105 #include <net/udp.h>
106 #include <net/udplite.h>
107 #include <linux/skbuff.h>
108 #include <net/sock.h>
109 #include <net/raw.h>
110 #include <net/icmp.h>
111 #include <net/ipip.h>
112 #include <net/inet_common.h>
113 #include <net/xfrm.h>
114 #include <net/net_namespace.h>
115 #ifdef CONFIG_IP_MROUTE
116 #include <linux/mroute.h>
117 #endif
118 
119 
120 /* The inetsw table contains everything that inet_create needs to
121  * build a new socket.
122  */
123 static struct list_head inetsw[SOCK_MAX];
124 static DEFINE_SPINLOCK(inetsw_lock);
125 
126 struct ipv4_config ipv4_config;
127 EXPORT_SYMBOL(ipv4_config);
128 
129 /* New destruction routine */
130 
131 void inet_sock_destruct(struct sock *sk)
132 {
133 	struct inet_sock *inet = inet_sk(sk);
134 
135 	__skb_queue_purge(&sk->sk_receive_queue);
136 	__skb_queue_purge(&sk->sk_error_queue);
137 
138 	sk_mem_reclaim(sk);
139 
140 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
141 		pr_err("Attempt to release TCP socket in state %d %p\n",
142 		       sk->sk_state, sk);
143 		return;
144 	}
145 	if (!sock_flag(sk, SOCK_DEAD)) {
146 		pr_err("Attempt to release alive inet socket %p\n", sk);
147 		return;
148 	}
149 
150 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
151 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
152 	WARN_ON(sk->sk_wmem_queued);
153 	WARN_ON(sk->sk_forward_alloc);
154 
155 	kfree(inet->opt);
156 	dst_release(sk->sk_dst_cache);
157 	sk_refcnt_debug_dec(sk);
158 }
159 EXPORT_SYMBOL(inet_sock_destruct);
160 
161 /*
162  *	The routines beyond this point handle the behaviour of an AF_INET
163  *	socket object. Mostly it punts to the subprotocols of IP to do
164  *	the work.
165  */
166 
167 /*
168  *	Automatically bind an unbound socket.
169  */
170 
171 static int inet_autobind(struct sock *sk)
172 {
173 	struct inet_sock *inet;
174 	/* We may need to bind the socket. */
175 	lock_sock(sk);
176 	inet = inet_sk(sk);
177 	if (!inet->num) {
178 		if (sk->sk_prot->get_port(sk, 0)) {
179 			release_sock(sk);
180 			return -EAGAIN;
181 		}
182 		inet->sport = htons(inet->num);
183 	}
184 	release_sock(sk);
185 	return 0;
186 }
187 
188 /*
189  *	Move a socket into listening state.
190  */
191 int inet_listen(struct socket *sock, int backlog)
192 {
193 	struct sock *sk = sock->sk;
194 	unsigned char old_state;
195 	int err;
196 
197 	lock_sock(sk);
198 
199 	err = -EINVAL;
200 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
201 		goto out;
202 
203 	old_state = sk->sk_state;
204 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
205 		goto out;
206 
207 	/* Really, if the socket is already in listen state
208 	 * we can only allow the backlog to be adjusted.
209 	 */
210 	if (old_state != TCP_LISTEN) {
211 		err = inet_csk_listen_start(sk, backlog);
212 		if (err)
213 			goto out;
214 	}
215 	sk->sk_max_ack_backlog = backlog;
216 	err = 0;
217 
218 out:
219 	release_sock(sk);
220 	return err;
221 }
222 EXPORT_SYMBOL(inet_listen);
223 
224 u32 inet_ehash_secret __read_mostly;
225 EXPORT_SYMBOL(inet_ehash_secret);
226 
227 /*
228  * inet_ehash_secret must be set exactly once
229  * Instead of using a dedicated spinlock, we (ab)use inetsw_lock
230  */
231 void build_ehash_secret(void)
232 {
233 	u32 rnd;
234 	do {
235 		get_random_bytes(&rnd, sizeof(rnd));
236 	} while (rnd == 0);
237 	spin_lock_bh(&inetsw_lock);
238 	if (!inet_ehash_secret)
239 		inet_ehash_secret = rnd;
240 	spin_unlock_bh(&inetsw_lock);
241 }
242 EXPORT_SYMBOL(build_ehash_secret);
243 
244 static inline int inet_netns_ok(struct net *net, int protocol)
245 {
246 	int hash;
247 	const struct net_protocol *ipprot;
248 
249 	if (net_eq(net, &init_net))
250 		return 1;
251 
252 	hash = protocol & (MAX_INET_PROTOS - 1);
253 	ipprot = rcu_dereference(inet_protos[hash]);
254 
255 	if (ipprot == NULL)
256 		/* raw IP is OK */
257 		return 1;
258 	return ipprot->netns_ok;
259 }
260 
261 /*
262  *	Create an inet socket.
263  */
264 
265 static int inet_create(struct net *net, struct socket *sock, int protocol)
266 {
267 	struct sock *sk;
268 	struct inet_protosw *answer;
269 	struct inet_sock *inet;
270 	struct proto *answer_prot;
271 	unsigned char answer_flags;
272 	char answer_no_check;
273 	int try_loading_module = 0;
274 	int err;
275 
276 	if (unlikely(!inet_ehash_secret))
277 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
278 			build_ehash_secret();
279 
280 	sock->state = SS_UNCONNECTED;
281 
282 	/* Look for the requested type/protocol pair. */
283 lookup_protocol:
284 	err = -ESOCKTNOSUPPORT;
285 	rcu_read_lock();
286 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
287 
288 		err = 0;
289 		/* Check the non-wild match. */
290 		if (protocol == answer->protocol) {
291 			if (protocol != IPPROTO_IP)
292 				break;
293 		} else {
294 			/* Check for the two wild cases. */
295 			if (IPPROTO_IP == protocol) {
296 				protocol = answer->protocol;
297 				break;
298 			}
299 			if (IPPROTO_IP == answer->protocol)
300 				break;
301 		}
302 		err = -EPROTONOSUPPORT;
303 	}
304 
305 	if (unlikely(err)) {
306 		if (try_loading_module < 2) {
307 			rcu_read_unlock();
308 			/*
309 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
310 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
311 			 */
312 			if (++try_loading_module == 1)
313 				request_module("net-pf-%d-proto-%d-type-%d",
314 					       PF_INET, protocol, sock->type);
315 			/*
316 			 * Fall back to generic, e.g. net-pf-2-proto-132
317 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
318 			 */
319 			else
320 				request_module("net-pf-%d-proto-%d",
321 					       PF_INET, protocol);
322 			goto lookup_protocol;
323 		} else
324 			goto out_rcu_unlock;
325 	}
326 
327 	err = -EPERM;
328 	if (answer->capability > 0 && !capable(answer->capability))
329 		goto out_rcu_unlock;
330 
331 	err = -EAFNOSUPPORT;
332 	if (!inet_netns_ok(net, protocol))
333 		goto out_rcu_unlock;
334 
335 	sock->ops = answer->ops;
336 	answer_prot = answer->prot;
337 	answer_no_check = answer->no_check;
338 	answer_flags = answer->flags;
339 	rcu_read_unlock();
340 
341 	WARN_ON(answer_prot->slab == NULL);
342 
343 	err = -ENOBUFS;
344 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
345 	if (sk == NULL)
346 		goto out;
347 
348 	err = 0;
349 	sk->sk_no_check = answer_no_check;
350 	if (INET_PROTOSW_REUSE & answer_flags)
351 		sk->sk_reuse = 1;
352 
353 	inet = inet_sk(sk);
354 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
355 
356 	if (SOCK_RAW == sock->type) {
357 		inet->num = protocol;
358 		if (IPPROTO_RAW == protocol)
359 			inet->hdrincl = 1;
360 	}
361 
362 	if (ipv4_config.no_pmtu_disc)
363 		inet->pmtudisc = IP_PMTUDISC_DONT;
364 	else
365 		inet->pmtudisc = IP_PMTUDISC_WANT;
366 
367 	inet->id = 0;
368 
369 	sock_init_data(sock, sk);
370 
371 	sk->sk_destruct	   = inet_sock_destruct;
372 	sk->sk_protocol	   = protocol;
373 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
374 
375 	inet->uc_ttl	= -1;
376 	inet->mc_loop	= 1;
377 	inet->mc_ttl	= 1;
378 	inet->mc_all	= 1;
379 	inet->mc_index	= 0;
380 	inet->mc_list	= NULL;
381 
382 	sk_refcnt_debug_inc(sk);
383 
384 	if (inet->num) {
385 		/* It assumes that any protocol which allows
386 		 * the user to assign a number at socket
387 		 * creation time automatically
388 		 * shares.
389 		 */
390 		inet->sport = htons(inet->num);
391 		/* Add to protocol hash chains. */
392 		sk->sk_prot->hash(sk);
393 	}
394 
395 	if (sk->sk_prot->init) {
396 		err = sk->sk_prot->init(sk);
397 		if (err)
398 			sk_common_release(sk);
399 	}
400 out:
401 	return err;
402 out_rcu_unlock:
403 	rcu_read_unlock();
404 	goto out;
405 }
406 
407 
408 /*
409  *	The peer socket should always be NULL (or else). When we call this
410  *	function we are destroying the object and from then on nobody
411  *	should refer to it.
412  */
413 int inet_release(struct socket *sock)
414 {
415 	struct sock *sk = sock->sk;
416 
417 	if (sk) {
418 		long timeout;
419 
420 		/* Applications forget to leave groups before exiting */
421 		ip_mc_drop_socket(sk);
422 
423 		/* If linger is set, we don't return until the close
424 		 * is complete.  Otherwise we return immediately. The
425 		 * actually closing is done the same either way.
426 		 *
427 		 * If the close is due to the process exiting, we never
428 		 * linger..
429 		 */
430 		timeout = 0;
431 		if (sock_flag(sk, SOCK_LINGER) &&
432 		    !(current->flags & PF_EXITING))
433 			timeout = sk->sk_lingertime;
434 		sock->sk = NULL;
435 		sk->sk_prot->close(sk, timeout);
436 	}
437 	return 0;
438 }
439 EXPORT_SYMBOL(inet_release);
440 
441 /* It is off by default, see below. */
442 int sysctl_ip_nonlocal_bind __read_mostly;
443 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
444 
445 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
446 {
447 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
448 	struct sock *sk = sock->sk;
449 	struct inet_sock *inet = inet_sk(sk);
450 	unsigned short snum;
451 	int chk_addr_ret;
452 	int err;
453 
454 	/* If the socket has its own bind function then use it. (RAW) */
455 	if (sk->sk_prot->bind) {
456 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
457 		goto out;
458 	}
459 	err = -EINVAL;
460 	if (addr_len < sizeof(struct sockaddr_in))
461 		goto out;
462 
463 	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
464 
465 	/* Not specified by any standard per-se, however it breaks too
466 	 * many applications when removed.  It is unfortunate since
467 	 * allowing applications to make a non-local bind solves
468 	 * several problems with systems using dynamic addressing.
469 	 * (ie. your servers still start up even if your ISDN link
470 	 *  is temporarily down)
471 	 */
472 	err = -EADDRNOTAVAIL;
473 	if (!sysctl_ip_nonlocal_bind &&
474 	    !(inet->freebind || inet->transparent) &&
475 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
476 	    chk_addr_ret != RTN_LOCAL &&
477 	    chk_addr_ret != RTN_MULTICAST &&
478 	    chk_addr_ret != RTN_BROADCAST)
479 		goto out;
480 
481 	snum = ntohs(addr->sin_port);
482 	err = -EACCES;
483 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
484 		goto out;
485 
486 	/*      We keep a pair of addresses. rcv_saddr is the one
487 	 *      used by hash lookups, and saddr is used for transmit.
488 	 *
489 	 *      In the BSD API these are the same except where it
490 	 *      would be illegal to use them (multicast/broadcast) in
491 	 *      which case the sending device address is used.
492 	 */
493 	lock_sock(sk);
494 
495 	/* Check these errors (active socket, double bind). */
496 	err = -EINVAL;
497 	if (sk->sk_state != TCP_CLOSE || inet->num)
498 		goto out_release_sock;
499 
500 	inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr;
501 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
502 		inet->saddr = 0;  /* Use device */
503 
504 	/* Make sure we are allowed to bind here. */
505 	if (sk->sk_prot->get_port(sk, snum)) {
506 		inet->saddr = inet->rcv_saddr = 0;
507 		err = -EADDRINUSE;
508 		goto out_release_sock;
509 	}
510 
511 	if (inet->rcv_saddr)
512 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
513 	if (snum)
514 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
515 	inet->sport = htons(inet->num);
516 	inet->daddr = 0;
517 	inet->dport = 0;
518 	sk_dst_reset(sk);
519 	err = 0;
520 out_release_sock:
521 	release_sock(sk);
522 out:
523 	return err;
524 }
525 EXPORT_SYMBOL(inet_bind);
526 
527 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
528 		       int addr_len, int flags)
529 {
530 	struct sock *sk = sock->sk;
531 
532 	if (uaddr->sa_family == AF_UNSPEC)
533 		return sk->sk_prot->disconnect(sk, flags);
534 
535 	if (!inet_sk(sk)->num && inet_autobind(sk))
536 		return -EAGAIN;
537 	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
538 }
539 EXPORT_SYMBOL(inet_dgram_connect);
540 
541 static long inet_wait_for_connect(struct sock *sk, long timeo)
542 {
543 	DEFINE_WAIT(wait);
544 
545 	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
546 
547 	/* Basic assumption: if someone sets sk->sk_err, he _must_
548 	 * change state of the socket from TCP_SYN_*.
549 	 * Connect() does not allow to get error notifications
550 	 * without closing the socket.
551 	 */
552 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
553 		release_sock(sk);
554 		timeo = schedule_timeout(timeo);
555 		lock_sock(sk);
556 		if (signal_pending(current) || !timeo)
557 			break;
558 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
559 	}
560 	finish_wait(sk->sk_sleep, &wait);
561 	return timeo;
562 }
563 
564 /*
565  *	Connect to a remote host. There is regrettably still a little
566  *	TCP 'magic' in here.
567  */
568 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
569 			int addr_len, int flags)
570 {
571 	struct sock *sk = sock->sk;
572 	int err;
573 	long timeo;
574 
575 	lock_sock(sk);
576 
577 	if (uaddr->sa_family == AF_UNSPEC) {
578 		err = sk->sk_prot->disconnect(sk, flags);
579 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
580 		goto out;
581 	}
582 
583 	switch (sock->state) {
584 	default:
585 		err = -EINVAL;
586 		goto out;
587 	case SS_CONNECTED:
588 		err = -EISCONN;
589 		goto out;
590 	case SS_CONNECTING:
591 		err = -EALREADY;
592 		/* Fall out of switch with err, set for this state */
593 		break;
594 	case SS_UNCONNECTED:
595 		err = -EISCONN;
596 		if (sk->sk_state != TCP_CLOSE)
597 			goto out;
598 
599 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
600 		if (err < 0)
601 			goto out;
602 
603 		sock->state = SS_CONNECTING;
604 
605 		/* Just entered SS_CONNECTING state; the only
606 		 * difference is that return value in non-blocking
607 		 * case is EINPROGRESS, rather than EALREADY.
608 		 */
609 		err = -EINPROGRESS;
610 		break;
611 	}
612 
613 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
614 
615 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
616 		/* Error code is set above */
617 		if (!timeo || !inet_wait_for_connect(sk, timeo))
618 			goto out;
619 
620 		err = sock_intr_errno(timeo);
621 		if (signal_pending(current))
622 			goto out;
623 	}
624 
625 	/* Connection was closed by RST, timeout, ICMP error
626 	 * or another process disconnected us.
627 	 */
628 	if (sk->sk_state == TCP_CLOSE)
629 		goto sock_error;
630 
631 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
632 	 * and error was received after socket entered established state.
633 	 * Hence, it is handled normally after connect() return successfully.
634 	 */
635 
636 	sock->state = SS_CONNECTED;
637 	err = 0;
638 out:
639 	release_sock(sk);
640 	return err;
641 
642 sock_error:
643 	err = sock_error(sk) ? : -ECONNABORTED;
644 	sock->state = SS_UNCONNECTED;
645 	if (sk->sk_prot->disconnect(sk, flags))
646 		sock->state = SS_DISCONNECTING;
647 	goto out;
648 }
649 EXPORT_SYMBOL(inet_stream_connect);
650 
651 /*
652  *	Accept a pending connection. The TCP layer now gives BSD semantics.
653  */
654 
655 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
656 {
657 	struct sock *sk1 = sock->sk;
658 	int err = -EINVAL;
659 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
660 
661 	if (!sk2)
662 		goto do_err;
663 
664 	lock_sock(sk2);
665 
666 	WARN_ON(!((1 << sk2->sk_state) &
667 		  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
668 
669 	sock_graft(sk2, newsock);
670 
671 	newsock->state = SS_CONNECTED;
672 	err = 0;
673 	release_sock(sk2);
674 do_err:
675 	return err;
676 }
677 EXPORT_SYMBOL(inet_accept);
678 
679 
680 /*
681  *	This does both peername and sockname.
682  */
683 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
684 			int *uaddr_len, int peer)
685 {
686 	struct sock *sk		= sock->sk;
687 	struct inet_sock *inet	= inet_sk(sk);
688 	struct sockaddr_in *sin	= (struct sockaddr_in *)uaddr;
689 
690 	sin->sin_family = AF_INET;
691 	if (peer) {
692 		if (!inet->dport ||
693 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
694 		     peer == 1))
695 			return -ENOTCONN;
696 		sin->sin_port = inet->dport;
697 		sin->sin_addr.s_addr = inet->daddr;
698 	} else {
699 		__be32 addr = inet->rcv_saddr;
700 		if (!addr)
701 			addr = inet->saddr;
702 		sin->sin_port = inet->sport;
703 		sin->sin_addr.s_addr = addr;
704 	}
705 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
706 	*uaddr_len = sizeof(*sin);
707 	return 0;
708 }
709 EXPORT_SYMBOL(inet_getname);
710 
711 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
712 		 size_t size)
713 {
714 	struct sock *sk = sock->sk;
715 
716 	/* We may need to bind the socket. */
717 	if (!inet_sk(sk)->num && inet_autobind(sk))
718 		return -EAGAIN;
719 
720 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
721 }
722 EXPORT_SYMBOL(inet_sendmsg);
723 
724 
725 static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
726 			     size_t size, int flags)
727 {
728 	struct sock *sk = sock->sk;
729 
730 	/* We may need to bind the socket. */
731 	if (!inet_sk(sk)->num && inet_autobind(sk))
732 		return -EAGAIN;
733 
734 	if (sk->sk_prot->sendpage)
735 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
736 	return sock_no_sendpage(sock, page, offset, size, flags);
737 }
738 
739 
740 int inet_shutdown(struct socket *sock, int how)
741 {
742 	struct sock *sk = sock->sk;
743 	int err = 0;
744 
745 	/* This should really check to make sure
746 	 * the socket is a TCP socket. (WHY AC...)
747 	 */
748 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
749 		       1->2 bit 2 snds.
750 		       2->3 */
751 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
752 		return -EINVAL;
753 
754 	lock_sock(sk);
755 	if (sock->state == SS_CONNECTING) {
756 		if ((1 << sk->sk_state) &
757 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
758 			sock->state = SS_DISCONNECTING;
759 		else
760 			sock->state = SS_CONNECTED;
761 	}
762 
763 	switch (sk->sk_state) {
764 	case TCP_CLOSE:
765 		err = -ENOTCONN;
766 		/* Hack to wake up other listeners, who can poll for
767 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
768 	default:
769 		sk->sk_shutdown |= how;
770 		if (sk->sk_prot->shutdown)
771 			sk->sk_prot->shutdown(sk, how);
772 		break;
773 
774 	/* Remaining two branches are temporary solution for missing
775 	 * close() in multithreaded environment. It is _not_ a good idea,
776 	 * but we have no choice until close() is repaired at VFS level.
777 	 */
778 	case TCP_LISTEN:
779 		if (!(how & RCV_SHUTDOWN))
780 			break;
781 		/* Fall through */
782 	case TCP_SYN_SENT:
783 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
784 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
785 		break;
786 	}
787 
788 	/* Wake up anyone sleeping in poll. */
789 	sk->sk_state_change(sk);
790 	release_sock(sk);
791 	return err;
792 }
793 EXPORT_SYMBOL(inet_shutdown);
794 
795 /*
796  *	ioctl() calls you can issue on an INET socket. Most of these are
797  *	device configuration and stuff and very rarely used. Some ioctls
798  *	pass on to the socket itself.
799  *
800  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
801  *	loads the devconfigure module does its configuring and unloads it.
802  *	There's a good 20K of config code hanging around the kernel.
803  */
804 
805 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
806 {
807 	struct sock *sk = sock->sk;
808 	int err = 0;
809 	struct net *net = sock_net(sk);
810 
811 	switch (cmd) {
812 	case SIOCGSTAMP:
813 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
814 		break;
815 	case SIOCGSTAMPNS:
816 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
817 		break;
818 	case SIOCADDRT:
819 	case SIOCDELRT:
820 	case SIOCRTMSG:
821 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
822 		break;
823 	case SIOCDARP:
824 	case SIOCGARP:
825 	case SIOCSARP:
826 		err = arp_ioctl(net, cmd, (void __user *)arg);
827 		break;
828 	case SIOCGIFADDR:
829 	case SIOCSIFADDR:
830 	case SIOCGIFBRDADDR:
831 	case SIOCSIFBRDADDR:
832 	case SIOCGIFNETMASK:
833 	case SIOCSIFNETMASK:
834 	case SIOCGIFDSTADDR:
835 	case SIOCSIFDSTADDR:
836 	case SIOCSIFPFLAGS:
837 	case SIOCGIFPFLAGS:
838 	case SIOCSIFFLAGS:
839 		err = devinet_ioctl(net, cmd, (void __user *)arg);
840 		break;
841 	default:
842 		if (sk->sk_prot->ioctl)
843 			err = sk->sk_prot->ioctl(sk, cmd, arg);
844 		else
845 			err = -ENOIOCTLCMD;
846 		break;
847 	}
848 	return err;
849 }
850 EXPORT_SYMBOL(inet_ioctl);
851 
852 const struct proto_ops inet_stream_ops = {
853 	.family		   = PF_INET,
854 	.owner		   = THIS_MODULE,
855 	.release	   = inet_release,
856 	.bind		   = inet_bind,
857 	.connect	   = inet_stream_connect,
858 	.socketpair	   = sock_no_socketpair,
859 	.accept		   = inet_accept,
860 	.getname	   = inet_getname,
861 	.poll		   = tcp_poll,
862 	.ioctl		   = inet_ioctl,
863 	.listen		   = inet_listen,
864 	.shutdown	   = inet_shutdown,
865 	.setsockopt	   = sock_common_setsockopt,
866 	.getsockopt	   = sock_common_getsockopt,
867 	.sendmsg	   = tcp_sendmsg,
868 	.recvmsg	   = sock_common_recvmsg,
869 	.mmap		   = sock_no_mmap,
870 	.sendpage	   = tcp_sendpage,
871 	.splice_read	   = tcp_splice_read,
872 #ifdef CONFIG_COMPAT
873 	.compat_setsockopt = compat_sock_common_setsockopt,
874 	.compat_getsockopt = compat_sock_common_getsockopt,
875 #endif
876 };
877 EXPORT_SYMBOL(inet_stream_ops);
878 
879 const struct proto_ops inet_dgram_ops = {
880 	.family		   = PF_INET,
881 	.owner		   = THIS_MODULE,
882 	.release	   = inet_release,
883 	.bind		   = inet_bind,
884 	.connect	   = inet_dgram_connect,
885 	.socketpair	   = sock_no_socketpair,
886 	.accept		   = sock_no_accept,
887 	.getname	   = inet_getname,
888 	.poll		   = udp_poll,
889 	.ioctl		   = inet_ioctl,
890 	.listen		   = sock_no_listen,
891 	.shutdown	   = inet_shutdown,
892 	.setsockopt	   = sock_common_setsockopt,
893 	.getsockopt	   = sock_common_getsockopt,
894 	.sendmsg	   = inet_sendmsg,
895 	.recvmsg	   = sock_common_recvmsg,
896 	.mmap		   = sock_no_mmap,
897 	.sendpage	   = inet_sendpage,
898 #ifdef CONFIG_COMPAT
899 	.compat_setsockopt = compat_sock_common_setsockopt,
900 	.compat_getsockopt = compat_sock_common_getsockopt,
901 #endif
902 };
903 EXPORT_SYMBOL(inet_dgram_ops);
904 
905 /*
906  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
907  * udp_poll
908  */
909 static const struct proto_ops inet_sockraw_ops = {
910 	.family		   = PF_INET,
911 	.owner		   = THIS_MODULE,
912 	.release	   = inet_release,
913 	.bind		   = inet_bind,
914 	.connect	   = inet_dgram_connect,
915 	.socketpair	   = sock_no_socketpair,
916 	.accept		   = sock_no_accept,
917 	.getname	   = inet_getname,
918 	.poll		   = datagram_poll,
919 	.ioctl		   = inet_ioctl,
920 	.listen		   = sock_no_listen,
921 	.shutdown	   = inet_shutdown,
922 	.setsockopt	   = sock_common_setsockopt,
923 	.getsockopt	   = sock_common_getsockopt,
924 	.sendmsg	   = inet_sendmsg,
925 	.recvmsg	   = sock_common_recvmsg,
926 	.mmap		   = sock_no_mmap,
927 	.sendpage	   = inet_sendpage,
928 #ifdef CONFIG_COMPAT
929 	.compat_setsockopt = compat_sock_common_setsockopt,
930 	.compat_getsockopt = compat_sock_common_getsockopt,
931 #endif
932 };
933 
934 static struct net_proto_family inet_family_ops = {
935 	.family = PF_INET,
936 	.create = inet_create,
937 	.owner	= THIS_MODULE,
938 };
939 
940 /* Upon startup we insert all the elements in inetsw_array[] into
941  * the linked list inetsw.
942  */
943 static struct inet_protosw inetsw_array[] =
944 {
945 	{
946 		.type =       SOCK_STREAM,
947 		.protocol =   IPPROTO_TCP,
948 		.prot =       &tcp_prot,
949 		.ops =        &inet_stream_ops,
950 		.capability = -1,
951 		.no_check =   0,
952 		.flags =      INET_PROTOSW_PERMANENT |
953 			      INET_PROTOSW_ICSK,
954 	},
955 
956 	{
957 		.type =       SOCK_DGRAM,
958 		.protocol =   IPPROTO_UDP,
959 		.prot =       &udp_prot,
960 		.ops =        &inet_dgram_ops,
961 		.capability = -1,
962 		.no_check =   UDP_CSUM_DEFAULT,
963 		.flags =      INET_PROTOSW_PERMANENT,
964        },
965 
966 
967        {
968 	       .type =       SOCK_RAW,
969 	       .protocol =   IPPROTO_IP,	/* wild card */
970 	       .prot =       &raw_prot,
971 	       .ops =        &inet_sockraw_ops,
972 	       .capability = CAP_NET_RAW,
973 	       .no_check =   UDP_CSUM_DEFAULT,
974 	       .flags =      INET_PROTOSW_REUSE,
975        }
976 };
977 
978 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
979 
980 void inet_register_protosw(struct inet_protosw *p)
981 {
982 	struct list_head *lh;
983 	struct inet_protosw *answer;
984 	int protocol = p->protocol;
985 	struct list_head *last_perm;
986 
987 	spin_lock_bh(&inetsw_lock);
988 
989 	if (p->type >= SOCK_MAX)
990 		goto out_illegal;
991 
992 	/* If we are trying to override a permanent protocol, bail. */
993 	answer = NULL;
994 	last_perm = &inetsw[p->type];
995 	list_for_each(lh, &inetsw[p->type]) {
996 		answer = list_entry(lh, struct inet_protosw, list);
997 
998 		/* Check only the non-wild match. */
999 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1000 			if (protocol == answer->protocol)
1001 				break;
1002 			last_perm = lh;
1003 		}
1004 
1005 		answer = NULL;
1006 	}
1007 	if (answer)
1008 		goto out_permanent;
1009 
1010 	/* Add the new entry after the last permanent entry if any, so that
1011 	 * the new entry does not override a permanent entry when matched with
1012 	 * a wild-card protocol. But it is allowed to override any existing
1013 	 * non-permanent entry.  This means that when we remove this entry, the
1014 	 * system automatically returns to the old behavior.
1015 	 */
1016 	list_add_rcu(&p->list, last_perm);
1017 out:
1018 	spin_unlock_bh(&inetsw_lock);
1019 
1020 	return;
1021 
1022 out_permanent:
1023 	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1024 	       protocol);
1025 	goto out;
1026 
1027 out_illegal:
1028 	printk(KERN_ERR
1029 	       "Ignoring attempt to register invalid socket type %d.\n",
1030 	       p->type);
1031 	goto out;
1032 }
1033 EXPORT_SYMBOL(inet_register_protosw);
1034 
1035 void inet_unregister_protosw(struct inet_protosw *p)
1036 {
1037 	if (INET_PROTOSW_PERMANENT & p->flags) {
1038 		printk(KERN_ERR
1039 		       "Attempt to unregister permanent protocol %d.\n",
1040 		       p->protocol);
1041 	} else {
1042 		spin_lock_bh(&inetsw_lock);
1043 		list_del_rcu(&p->list);
1044 		spin_unlock_bh(&inetsw_lock);
1045 
1046 		synchronize_net();
1047 	}
1048 }
1049 EXPORT_SYMBOL(inet_unregister_protosw);
1050 
1051 /*
1052  *      Shall we try to damage output packets if routing dev changes?
1053  */
1054 
1055 int sysctl_ip_dynaddr __read_mostly;
1056 
1057 static int inet_sk_reselect_saddr(struct sock *sk)
1058 {
1059 	struct inet_sock *inet = inet_sk(sk);
1060 	int err;
1061 	struct rtable *rt;
1062 	__be32 old_saddr = inet->saddr;
1063 	__be32 new_saddr;
1064 	__be32 daddr = inet->daddr;
1065 
1066 	if (inet->opt && inet->opt->srr)
1067 		daddr = inet->opt->faddr;
1068 
1069 	/* Query new route. */
1070 	err = ip_route_connect(&rt, daddr, 0,
1071 			       RT_CONN_FLAGS(sk),
1072 			       sk->sk_bound_dev_if,
1073 			       sk->sk_protocol,
1074 			       inet->sport, inet->dport, sk, 0);
1075 	if (err)
1076 		return err;
1077 
1078 	sk_setup_caps(sk, &rt->u.dst);
1079 
1080 	new_saddr = rt->rt_src;
1081 
1082 	if (new_saddr == old_saddr)
1083 		return 0;
1084 
1085 	if (sysctl_ip_dynaddr > 1) {
1086 		printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1087 		       __func__, &old_saddr, &new_saddr);
1088 	}
1089 
1090 	inet->saddr = inet->rcv_saddr = new_saddr;
1091 
1092 	/*
1093 	 * XXX The only one ugly spot where we need to
1094 	 * XXX really change the sockets identity after
1095 	 * XXX it has entered the hashes. -DaveM
1096 	 *
1097 	 * Besides that, it does not check for connection
1098 	 * uniqueness. Wait for troubles.
1099 	 */
1100 	__sk_prot_rehash(sk);
1101 	return 0;
1102 }
1103 
1104 int inet_sk_rebuild_header(struct sock *sk)
1105 {
1106 	struct inet_sock *inet = inet_sk(sk);
1107 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1108 	__be32 daddr;
1109 	int err;
1110 
1111 	/* Route is OK, nothing to do. */
1112 	if (rt)
1113 		return 0;
1114 
1115 	/* Reroute. */
1116 	daddr = inet->daddr;
1117 	if (inet->opt && inet->opt->srr)
1118 		daddr = inet->opt->faddr;
1119 {
1120 	struct flowi fl = {
1121 		.oif = sk->sk_bound_dev_if,
1122 		.mark = sk->sk_mark,
1123 		.nl_u = {
1124 			.ip4_u = {
1125 				.daddr	= daddr,
1126 				.saddr	= inet->saddr,
1127 				.tos	= RT_CONN_FLAGS(sk),
1128 			},
1129 		},
1130 		.proto = sk->sk_protocol,
1131 		.flags = inet_sk_flowi_flags(sk),
1132 		.uli_u = {
1133 			.ports = {
1134 				.sport = inet->sport,
1135 				.dport = inet->dport,
1136 			},
1137 		},
1138 	};
1139 
1140 	security_sk_classify_flow(sk, &fl);
1141 	err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0);
1142 }
1143 	if (!err)
1144 		sk_setup_caps(sk, &rt->u.dst);
1145 	else {
1146 		/* Routing failed... */
1147 		sk->sk_route_caps = 0;
1148 		/*
1149 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1150 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1151 		 */
1152 		if (!sysctl_ip_dynaddr ||
1153 		    sk->sk_state != TCP_SYN_SENT ||
1154 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1155 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1156 			sk->sk_err_soft = -err;
1157 	}
1158 
1159 	return err;
1160 }
1161 EXPORT_SYMBOL(inet_sk_rebuild_header);
1162 
1163 static int inet_gso_send_check(struct sk_buff *skb)
1164 {
1165 	struct iphdr *iph;
1166 	const struct net_protocol *ops;
1167 	int proto;
1168 	int ihl;
1169 	int err = -EINVAL;
1170 
1171 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1172 		goto out;
1173 
1174 	iph = ip_hdr(skb);
1175 	ihl = iph->ihl * 4;
1176 	if (ihl < sizeof(*iph))
1177 		goto out;
1178 
1179 	if (unlikely(!pskb_may_pull(skb, ihl)))
1180 		goto out;
1181 
1182 	__skb_pull(skb, ihl);
1183 	skb_reset_transport_header(skb);
1184 	iph = ip_hdr(skb);
1185 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1186 	err = -EPROTONOSUPPORT;
1187 
1188 	rcu_read_lock();
1189 	ops = rcu_dereference(inet_protos[proto]);
1190 	if (likely(ops && ops->gso_send_check))
1191 		err = ops->gso_send_check(skb);
1192 	rcu_read_unlock();
1193 
1194 out:
1195 	return err;
1196 }
1197 
1198 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
1199 {
1200 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1201 	struct iphdr *iph;
1202 	const struct net_protocol *ops;
1203 	int proto;
1204 	int ihl;
1205 	int id;
1206 	unsigned int offset = 0;
1207 
1208 	if (!(features & NETIF_F_V4_CSUM))
1209 		features &= ~NETIF_F_SG;
1210 
1211 	if (unlikely(skb_shinfo(skb)->gso_type &
1212 		     ~(SKB_GSO_TCPV4 |
1213 		       SKB_GSO_UDP |
1214 		       SKB_GSO_DODGY |
1215 		       SKB_GSO_TCP_ECN |
1216 		       0)))
1217 		goto out;
1218 
1219 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1220 		goto out;
1221 
1222 	iph = ip_hdr(skb);
1223 	ihl = iph->ihl * 4;
1224 	if (ihl < sizeof(*iph))
1225 		goto out;
1226 
1227 	if (unlikely(!pskb_may_pull(skb, ihl)))
1228 		goto out;
1229 
1230 	__skb_pull(skb, ihl);
1231 	skb_reset_transport_header(skb);
1232 	iph = ip_hdr(skb);
1233 	id = ntohs(iph->id);
1234 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1235 	segs = ERR_PTR(-EPROTONOSUPPORT);
1236 
1237 	rcu_read_lock();
1238 	ops = rcu_dereference(inet_protos[proto]);
1239 	if (likely(ops && ops->gso_segment))
1240 		segs = ops->gso_segment(skb, features);
1241 	rcu_read_unlock();
1242 
1243 	if (!segs || IS_ERR(segs))
1244 		goto out;
1245 
1246 	skb = segs;
1247 	do {
1248 		iph = ip_hdr(skb);
1249 		if (proto == IPPROTO_UDP) {
1250 			iph->id = htons(id);
1251 			iph->frag_off = htons(offset >> 3);
1252 			if (skb->next != NULL)
1253 				iph->frag_off |= htons(IP_MF);
1254 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1255 		} else
1256 			iph->id = htons(id++);
1257 		iph->tot_len = htons(skb->len - skb->mac_len);
1258 		iph->check = 0;
1259 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1260 	} while ((skb = skb->next));
1261 
1262 out:
1263 	return segs;
1264 }
1265 
1266 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1267 					 struct sk_buff *skb)
1268 {
1269 	const struct net_protocol *ops;
1270 	struct sk_buff **pp = NULL;
1271 	struct sk_buff *p;
1272 	struct iphdr *iph;
1273 	unsigned int hlen;
1274 	unsigned int off;
1275 	unsigned int id;
1276 	int flush = 1;
1277 	int proto;
1278 
1279 	off = skb_gro_offset(skb);
1280 	hlen = off + sizeof(*iph);
1281 	iph = skb_gro_header_fast(skb, off);
1282 	if (skb_gro_header_hard(skb, hlen)) {
1283 		iph = skb_gro_header_slow(skb, hlen, off);
1284 		if (unlikely(!iph))
1285 			goto out;
1286 	}
1287 
1288 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1289 
1290 	rcu_read_lock();
1291 	ops = rcu_dereference(inet_protos[proto]);
1292 	if (!ops || !ops->gro_receive)
1293 		goto out_unlock;
1294 
1295 	if (*(u8 *)iph != 0x45)
1296 		goto out_unlock;
1297 
1298 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1299 		goto out_unlock;
1300 
1301 	id = ntohl(*(u32 *)&iph->id);
1302 	flush = (u16)((ntohl(*(u32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1303 	id >>= 16;
1304 
1305 	for (p = *head; p; p = p->next) {
1306 		struct iphdr *iph2;
1307 
1308 		if (!NAPI_GRO_CB(p)->same_flow)
1309 			continue;
1310 
1311 		iph2 = ip_hdr(p);
1312 
1313 		if ((iph->protocol ^ iph2->protocol) |
1314 		    (iph->tos ^ iph2->tos) |
1315 		    (iph->saddr ^ iph2->saddr) |
1316 		    (iph->daddr ^ iph2->daddr)) {
1317 			NAPI_GRO_CB(p)->same_flow = 0;
1318 			continue;
1319 		}
1320 
1321 		/* All fields must match except length and checksum. */
1322 		NAPI_GRO_CB(p)->flush |=
1323 			(iph->ttl ^ iph2->ttl) |
1324 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1325 
1326 		NAPI_GRO_CB(p)->flush |= flush;
1327 	}
1328 
1329 	NAPI_GRO_CB(skb)->flush |= flush;
1330 	skb_gro_pull(skb, sizeof(*iph));
1331 	skb_set_transport_header(skb, skb_gro_offset(skb));
1332 
1333 	pp = ops->gro_receive(head, skb);
1334 
1335 out_unlock:
1336 	rcu_read_unlock();
1337 
1338 out:
1339 	NAPI_GRO_CB(skb)->flush |= flush;
1340 
1341 	return pp;
1342 }
1343 
1344 static int inet_gro_complete(struct sk_buff *skb)
1345 {
1346 	const struct net_protocol *ops;
1347 	struct iphdr *iph = ip_hdr(skb);
1348 	int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1349 	int err = -ENOSYS;
1350 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1351 
1352 	csum_replace2(&iph->check, iph->tot_len, newlen);
1353 	iph->tot_len = newlen;
1354 
1355 	rcu_read_lock();
1356 	ops = rcu_dereference(inet_protos[proto]);
1357 	if (WARN_ON(!ops || !ops->gro_complete))
1358 		goto out_unlock;
1359 
1360 	err = ops->gro_complete(skb);
1361 
1362 out_unlock:
1363 	rcu_read_unlock();
1364 
1365 	return err;
1366 }
1367 
1368 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1369 			 unsigned short type, unsigned char protocol,
1370 			 struct net *net)
1371 {
1372 	struct socket *sock;
1373 	int rc = sock_create_kern(family, type, protocol, &sock);
1374 
1375 	if (rc == 0) {
1376 		*sk = sock->sk;
1377 		(*sk)->sk_allocation = GFP_ATOMIC;
1378 		/*
1379 		 * Unhash it so that IP input processing does not even see it,
1380 		 * we do not wish this socket to see incoming packets.
1381 		 */
1382 		(*sk)->sk_prot->unhash(*sk);
1383 
1384 		sk_change_net(*sk, net);
1385 	}
1386 	return rc;
1387 }
1388 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1389 
1390 unsigned long snmp_fold_field(void *mib[], int offt)
1391 {
1392 	unsigned long res = 0;
1393 	int i;
1394 
1395 	for_each_possible_cpu(i) {
1396 		res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1397 		res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1398 	}
1399 	return res;
1400 }
1401 EXPORT_SYMBOL_GPL(snmp_fold_field);
1402 
1403 int snmp_mib_init(void *ptr[2], size_t mibsize)
1404 {
1405 	BUG_ON(ptr == NULL);
1406 	ptr[0] = __alloc_percpu(mibsize, __alignof__(unsigned long long));
1407 	if (!ptr[0])
1408 		goto err0;
1409 	ptr[1] = __alloc_percpu(mibsize, __alignof__(unsigned long long));
1410 	if (!ptr[1])
1411 		goto err1;
1412 	return 0;
1413 err1:
1414 	free_percpu(ptr[0]);
1415 	ptr[0] = NULL;
1416 err0:
1417 	return -ENOMEM;
1418 }
1419 EXPORT_SYMBOL_GPL(snmp_mib_init);
1420 
1421 void snmp_mib_free(void *ptr[2])
1422 {
1423 	BUG_ON(ptr == NULL);
1424 	free_percpu(ptr[0]);
1425 	free_percpu(ptr[1]);
1426 	ptr[0] = ptr[1] = NULL;
1427 }
1428 EXPORT_SYMBOL_GPL(snmp_mib_free);
1429 
1430 #ifdef CONFIG_IP_MULTICAST
1431 static const struct net_protocol igmp_protocol = {
1432 	.handler =	igmp_rcv,
1433 	.netns_ok =	1,
1434 };
1435 #endif
1436 
1437 static const struct net_protocol tcp_protocol = {
1438 	.handler =	tcp_v4_rcv,
1439 	.err_handler =	tcp_v4_err,
1440 	.gso_send_check = tcp_v4_gso_send_check,
1441 	.gso_segment =	tcp_tso_segment,
1442 	.gro_receive =	tcp4_gro_receive,
1443 	.gro_complete =	tcp4_gro_complete,
1444 	.no_policy =	1,
1445 	.netns_ok =	1,
1446 };
1447 
1448 static const struct net_protocol udp_protocol = {
1449 	.handler =	udp_rcv,
1450 	.err_handler =	udp_err,
1451 	.gso_send_check = udp4_ufo_send_check,
1452 	.gso_segment = udp4_ufo_fragment,
1453 	.no_policy =	1,
1454 	.netns_ok =	1,
1455 };
1456 
1457 static const struct net_protocol icmp_protocol = {
1458 	.handler =	icmp_rcv,
1459 	.no_policy =	1,
1460 	.netns_ok =	1,
1461 };
1462 
1463 static __net_init int ipv4_mib_init_net(struct net *net)
1464 {
1465 	if (snmp_mib_init((void **)net->mib.tcp_statistics,
1466 			  sizeof(struct tcp_mib)) < 0)
1467 		goto err_tcp_mib;
1468 	if (snmp_mib_init((void **)net->mib.ip_statistics,
1469 			  sizeof(struct ipstats_mib)) < 0)
1470 		goto err_ip_mib;
1471 	if (snmp_mib_init((void **)net->mib.net_statistics,
1472 			  sizeof(struct linux_mib)) < 0)
1473 		goto err_net_mib;
1474 	if (snmp_mib_init((void **)net->mib.udp_statistics,
1475 			  sizeof(struct udp_mib)) < 0)
1476 		goto err_udp_mib;
1477 	if (snmp_mib_init((void **)net->mib.udplite_statistics,
1478 			  sizeof(struct udp_mib)) < 0)
1479 		goto err_udplite_mib;
1480 	if (snmp_mib_init((void **)net->mib.icmp_statistics,
1481 			  sizeof(struct icmp_mib)) < 0)
1482 		goto err_icmp_mib;
1483 	if (snmp_mib_init((void **)net->mib.icmpmsg_statistics,
1484 			  sizeof(struct icmpmsg_mib)) < 0)
1485 		goto err_icmpmsg_mib;
1486 
1487 	tcp_mib_init(net);
1488 	return 0;
1489 
1490 err_icmpmsg_mib:
1491 	snmp_mib_free((void **)net->mib.icmp_statistics);
1492 err_icmp_mib:
1493 	snmp_mib_free((void **)net->mib.udplite_statistics);
1494 err_udplite_mib:
1495 	snmp_mib_free((void **)net->mib.udp_statistics);
1496 err_udp_mib:
1497 	snmp_mib_free((void **)net->mib.net_statistics);
1498 err_net_mib:
1499 	snmp_mib_free((void **)net->mib.ip_statistics);
1500 err_ip_mib:
1501 	snmp_mib_free((void **)net->mib.tcp_statistics);
1502 err_tcp_mib:
1503 	return -ENOMEM;
1504 }
1505 
1506 static __net_exit void ipv4_mib_exit_net(struct net *net)
1507 {
1508 	snmp_mib_free((void **)net->mib.icmpmsg_statistics);
1509 	snmp_mib_free((void **)net->mib.icmp_statistics);
1510 	snmp_mib_free((void **)net->mib.udplite_statistics);
1511 	snmp_mib_free((void **)net->mib.udp_statistics);
1512 	snmp_mib_free((void **)net->mib.net_statistics);
1513 	snmp_mib_free((void **)net->mib.ip_statistics);
1514 	snmp_mib_free((void **)net->mib.tcp_statistics);
1515 }
1516 
1517 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1518 	.init = ipv4_mib_init_net,
1519 	.exit = ipv4_mib_exit_net,
1520 };
1521 
1522 static int __init init_ipv4_mibs(void)
1523 {
1524 	return register_pernet_subsys(&ipv4_mib_ops);
1525 }
1526 
1527 static int ipv4_proc_init(void);
1528 
1529 /*
1530  *	IP protocol layer initialiser
1531  */
1532 
1533 static struct packet_type ip_packet_type __read_mostly = {
1534 	.type = cpu_to_be16(ETH_P_IP),
1535 	.func = ip_rcv,
1536 	.gso_send_check = inet_gso_send_check,
1537 	.gso_segment = inet_gso_segment,
1538 	.gro_receive = inet_gro_receive,
1539 	.gro_complete = inet_gro_complete,
1540 };
1541 
1542 static int __init inet_init(void)
1543 {
1544 	struct sk_buff *dummy_skb;
1545 	struct inet_protosw *q;
1546 	struct list_head *r;
1547 	int rc = -EINVAL;
1548 
1549 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1550 
1551 	rc = proto_register(&tcp_prot, 1);
1552 	if (rc)
1553 		goto out;
1554 
1555 	rc = proto_register(&udp_prot, 1);
1556 	if (rc)
1557 		goto out_unregister_tcp_proto;
1558 
1559 	rc = proto_register(&raw_prot, 1);
1560 	if (rc)
1561 		goto out_unregister_udp_proto;
1562 
1563 	/*
1564 	 *	Tell SOCKET that we are alive...
1565 	 */
1566 
1567 	(void)sock_register(&inet_family_ops);
1568 
1569 #ifdef CONFIG_SYSCTL
1570 	ip_static_sysctl_init();
1571 #endif
1572 
1573 	/*
1574 	 *	Add all the base protocols.
1575 	 */
1576 
1577 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1578 		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1579 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1580 		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1581 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1582 		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1583 #ifdef CONFIG_IP_MULTICAST
1584 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1585 		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1586 #endif
1587 
1588 	/* Register the socket-side information for inet_create. */
1589 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1590 		INIT_LIST_HEAD(r);
1591 
1592 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1593 		inet_register_protosw(q);
1594 
1595 	/*
1596 	 *	Set the ARP module up
1597 	 */
1598 
1599 	arp_init();
1600 
1601 	/*
1602 	 *	Set the IP module up
1603 	 */
1604 
1605 	ip_init();
1606 
1607 	tcp_v4_init();
1608 
1609 	/* Setup TCP slab cache for open requests. */
1610 	tcp_init();
1611 
1612 	/* Setup UDP memory threshold */
1613 	udp_init();
1614 
1615 	/* Add UDP-Lite (RFC 3828) */
1616 	udplite4_register();
1617 
1618 	/*
1619 	 *	Set the ICMP layer up
1620 	 */
1621 
1622 	if (icmp_init() < 0)
1623 		panic("Failed to create the ICMP control socket.\n");
1624 
1625 	/*
1626 	 *	Initialise the multicast router
1627 	 */
1628 #if defined(CONFIG_IP_MROUTE)
1629 	if (ip_mr_init())
1630 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1631 #endif
1632 	/*
1633 	 *	Initialise per-cpu ipv4 mibs
1634 	 */
1635 
1636 	if (init_ipv4_mibs())
1637 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1638 
1639 	ipv4_proc_init();
1640 
1641 	ipfrag_init();
1642 
1643 	dev_add_pack(&ip_packet_type);
1644 
1645 	rc = 0;
1646 out:
1647 	return rc;
1648 out_unregister_udp_proto:
1649 	proto_unregister(&udp_prot);
1650 out_unregister_tcp_proto:
1651 	proto_unregister(&tcp_prot);
1652 	goto out;
1653 }
1654 
1655 fs_initcall(inet_init);
1656 
1657 /* ------------------------------------------------------------------------ */
1658 
1659 #ifdef CONFIG_PROC_FS
1660 static int __init ipv4_proc_init(void)
1661 {
1662 	int rc = 0;
1663 
1664 	if (raw_proc_init())
1665 		goto out_raw;
1666 	if (tcp4_proc_init())
1667 		goto out_tcp;
1668 	if (udp4_proc_init())
1669 		goto out_udp;
1670 	if (ip_misc_proc_init())
1671 		goto out_misc;
1672 out:
1673 	return rc;
1674 out_misc:
1675 	udp4_proc_exit();
1676 out_udp:
1677 	tcp4_proc_exit();
1678 out_tcp:
1679 	raw_proc_exit();
1680 out_raw:
1681 	rc = -ENOMEM;
1682 	goto out;
1683 }
1684 
1685 #else /* CONFIG_PROC_FS */
1686 static int __init ipv4_proc_init(void)
1687 {
1688 	return 0;
1689 }
1690 #endif /* CONFIG_PROC_FS */
1691 
1692 MODULE_ALIAS_NETPROTO(PF_INET);
1693 
1694