xref: /linux/net/ipv4/af_inet.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
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 #include <linux/slab.h>
90 
91 #include <asm/uaccess.h>
92 #include <asm/system.h>
93 
94 #include <linux/inet.h>
95 #include <linux/igmp.h>
96 #include <linux/inetdevice.h>
97 #include <linux/netdevice.h>
98 #include <net/checksum.h>
99 #include <net/ip.h>
100 #include <net/protocol.h>
101 #include <net/arp.h>
102 #include <net/route.h>
103 #include <net/ip_fib.h>
104 #include <net/inet_connection_sock.h>
105 #include <net/tcp.h>
106 #include <net/udp.h>
107 #include <net/udplite.h>
108 #include <linux/skbuff.h>
109 #include <net/sock.h>
110 #include <net/raw.h>
111 #include <net/icmp.h>
112 #include <net/ipip.h>
113 #include <net/inet_common.h>
114 #include <net/xfrm.h>
115 #include <net/net_namespace.h>
116 #ifdef CONFIG_IP_MROUTE
117 #include <linux/mroute.h>
118 #endif
119 
120 
121 /* The inetsw table contains everything that inet_create needs to
122  * build a new socket.
123  */
124 static struct list_head inetsw[SOCK_MAX];
125 static DEFINE_SPINLOCK(inetsw_lock);
126 
127 struct ipv4_config ipv4_config;
128 EXPORT_SYMBOL(ipv4_config);
129 
130 /* New destruction routine */
131 
132 void inet_sock_destruct(struct sock *sk)
133 {
134 	struct inet_sock *inet = inet_sk(sk);
135 
136 	__skb_queue_purge(&sk->sk_receive_queue);
137 	__skb_queue_purge(&sk->sk_error_queue);
138 
139 	sk_mem_reclaim(sk);
140 
141 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
142 		pr_err("Attempt to release TCP socket in state %d %p\n",
143 		       sk->sk_state, sk);
144 		return;
145 	}
146 	if (!sock_flag(sk, SOCK_DEAD)) {
147 		pr_err("Attempt to release alive inet socket %p\n", sk);
148 		return;
149 	}
150 
151 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
152 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
153 	WARN_ON(sk->sk_wmem_queued);
154 	WARN_ON(sk->sk_forward_alloc);
155 
156 	kfree(inet->opt);
157 	dst_release(sk->sk_dst_cache);
158 	sk_refcnt_debug_dec(sk);
159 }
160 EXPORT_SYMBOL(inet_sock_destruct);
161 
162 /*
163  *	The routines beyond this point handle the behaviour of an AF_INET
164  *	socket object. Mostly it punts to the subprotocols of IP to do
165  *	the work.
166  */
167 
168 /*
169  *	Automatically bind an unbound socket.
170  */
171 
172 static int inet_autobind(struct sock *sk)
173 {
174 	struct inet_sock *inet;
175 	/* We may need to bind the socket. */
176 	lock_sock(sk);
177 	inet = inet_sk(sk);
178 	if (!inet->inet_num) {
179 		if (sk->sk_prot->get_port(sk, 0)) {
180 			release_sock(sk);
181 			return -EAGAIN;
182 		}
183 		inet->inet_sport = htons(inet->inet_num);
184 	}
185 	release_sock(sk);
186 	return 0;
187 }
188 
189 /*
190  *	Move a socket into listening state.
191  */
192 int inet_listen(struct socket *sock, int backlog)
193 {
194 	struct sock *sk = sock->sk;
195 	unsigned char old_state;
196 	int err;
197 
198 	lock_sock(sk);
199 
200 	err = -EINVAL;
201 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
202 		goto out;
203 
204 	old_state = sk->sk_state;
205 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
206 		goto out;
207 
208 	/* Really, if the socket is already in listen state
209 	 * we can only allow the backlog to be adjusted.
210 	 */
211 	if (old_state != TCP_LISTEN) {
212 		err = inet_csk_listen_start(sk, backlog);
213 		if (err)
214 			goto out;
215 	}
216 	sk->sk_max_ack_backlog = backlog;
217 	err = 0;
218 
219 out:
220 	release_sock(sk);
221 	return err;
222 }
223 EXPORT_SYMBOL(inet_listen);
224 
225 u32 inet_ehash_secret __read_mostly;
226 EXPORT_SYMBOL(inet_ehash_secret);
227 
228 /*
229  * inet_ehash_secret must be set exactly once
230  * Instead of using a dedicated spinlock, we (ab)use inetsw_lock
231  */
232 void build_ehash_secret(void)
233 {
234 	u32 rnd;
235 	do {
236 		get_random_bytes(&rnd, sizeof(rnd));
237 	} while (rnd == 0);
238 	spin_lock_bh(&inetsw_lock);
239 	if (!inet_ehash_secret)
240 		inet_ehash_secret = rnd;
241 	spin_unlock_bh(&inetsw_lock);
242 }
243 EXPORT_SYMBOL(build_ehash_secret);
244 
245 static inline int inet_netns_ok(struct net *net, int protocol)
246 {
247 	int hash;
248 	const struct net_protocol *ipprot;
249 
250 	if (net_eq(net, &init_net))
251 		return 1;
252 
253 	hash = protocol & (MAX_INET_PROTOS - 1);
254 	ipprot = rcu_dereference(inet_protos[hash]);
255 
256 	if (ipprot == NULL)
257 		/* raw IP is OK */
258 		return 1;
259 	return ipprot->netns_ok;
260 }
261 
262 /*
263  *	Create an inet socket.
264  */
265 
266 static int inet_create(struct net *net, struct socket *sock, int protocol,
267 		       int kern)
268 {
269 	struct sock *sk;
270 	struct inet_protosw *answer;
271 	struct inet_sock *inet;
272 	struct proto *answer_prot;
273 	unsigned char answer_flags;
274 	char answer_no_check;
275 	int try_loading_module = 0;
276 	int err;
277 
278 	if (unlikely(!inet_ehash_secret))
279 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
280 			build_ehash_secret();
281 
282 	sock->state = SS_UNCONNECTED;
283 
284 	/* Look for the requested type/protocol pair. */
285 lookup_protocol:
286 	err = -ESOCKTNOSUPPORT;
287 	rcu_read_lock();
288 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
289 
290 		err = 0;
291 		/* Check the non-wild match. */
292 		if (protocol == answer->protocol) {
293 			if (protocol != IPPROTO_IP)
294 				break;
295 		} else {
296 			/* Check for the two wild cases. */
297 			if (IPPROTO_IP == protocol) {
298 				protocol = answer->protocol;
299 				break;
300 			}
301 			if (IPPROTO_IP == answer->protocol)
302 				break;
303 		}
304 		err = -EPROTONOSUPPORT;
305 	}
306 
307 	if (unlikely(err)) {
308 		if (try_loading_module < 2) {
309 			rcu_read_unlock();
310 			/*
311 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
312 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
313 			 */
314 			if (++try_loading_module == 1)
315 				request_module("net-pf-%d-proto-%d-type-%d",
316 					       PF_INET, protocol, sock->type);
317 			/*
318 			 * Fall back to generic, e.g. net-pf-2-proto-132
319 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
320 			 */
321 			else
322 				request_module("net-pf-%d-proto-%d",
323 					       PF_INET, protocol);
324 			goto lookup_protocol;
325 		} else
326 			goto out_rcu_unlock;
327 	}
328 
329 	err = -EPERM;
330 	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
331 		goto out_rcu_unlock;
332 
333 	err = -EAFNOSUPPORT;
334 	if (!inet_netns_ok(net, protocol))
335 		goto out_rcu_unlock;
336 
337 	sock->ops = answer->ops;
338 	answer_prot = answer->prot;
339 	answer_no_check = answer->no_check;
340 	answer_flags = answer->flags;
341 	rcu_read_unlock();
342 
343 	WARN_ON(answer_prot->slab == NULL);
344 
345 	err = -ENOBUFS;
346 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
347 	if (sk == NULL)
348 		goto out;
349 
350 	err = 0;
351 	sk->sk_no_check = answer_no_check;
352 	if (INET_PROTOSW_REUSE & answer_flags)
353 		sk->sk_reuse = 1;
354 
355 	inet = inet_sk(sk);
356 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
357 
358 	if (SOCK_RAW == sock->type) {
359 		inet->inet_num = protocol;
360 		if (IPPROTO_RAW == protocol)
361 			inet->hdrincl = 1;
362 	}
363 
364 	if (ipv4_config.no_pmtu_disc)
365 		inet->pmtudisc = IP_PMTUDISC_DONT;
366 	else
367 		inet->pmtudisc = IP_PMTUDISC_WANT;
368 
369 	inet->inet_id = 0;
370 
371 	sock_init_data(sock, sk);
372 
373 	sk->sk_destruct	   = inet_sock_destruct;
374 	sk->sk_protocol	   = protocol;
375 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
376 
377 	inet->uc_ttl	= -1;
378 	inet->mc_loop	= 1;
379 	inet->mc_ttl	= 1;
380 	inet->mc_all	= 1;
381 	inet->mc_index	= 0;
382 	inet->mc_list	= NULL;
383 
384 	sk_refcnt_debug_inc(sk);
385 
386 	if (inet->inet_num) {
387 		/* It assumes that any protocol which allows
388 		 * the user to assign a number at socket
389 		 * creation time automatically
390 		 * shares.
391 		 */
392 		inet->inet_sport = htons(inet->inet_num);
393 		/* Add to protocol hash chains. */
394 		sk->sk_prot->hash(sk);
395 	}
396 
397 	if (sk->sk_prot->init) {
398 		err = sk->sk_prot->init(sk);
399 		if (err)
400 			sk_common_release(sk);
401 	}
402 out:
403 	return err;
404 out_rcu_unlock:
405 	rcu_read_unlock();
406 	goto out;
407 }
408 
409 
410 /*
411  *	The peer socket should always be NULL (or else). When we call this
412  *	function we are destroying the object and from then on nobody
413  *	should refer to it.
414  */
415 int inet_release(struct socket *sock)
416 {
417 	struct sock *sk = sock->sk;
418 
419 	if (sk) {
420 		long timeout;
421 
422 		/* Applications forget to leave groups before exiting */
423 		ip_mc_drop_socket(sk);
424 
425 		/* If linger is set, we don't return until the close
426 		 * is complete.  Otherwise we return immediately. The
427 		 * actually closing is done the same either way.
428 		 *
429 		 * If the close is due to the process exiting, we never
430 		 * linger..
431 		 */
432 		timeout = 0;
433 		if (sock_flag(sk, SOCK_LINGER) &&
434 		    !(current->flags & PF_EXITING))
435 			timeout = sk->sk_lingertime;
436 		sock->sk = NULL;
437 		sk->sk_prot->close(sk, timeout);
438 	}
439 	return 0;
440 }
441 EXPORT_SYMBOL(inet_release);
442 
443 /* It is off by default, see below. */
444 int sysctl_ip_nonlocal_bind __read_mostly;
445 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
446 
447 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
448 {
449 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
450 	struct sock *sk = sock->sk;
451 	struct inet_sock *inet = inet_sk(sk);
452 	unsigned short snum;
453 	int chk_addr_ret;
454 	int err;
455 
456 	/* If the socket has its own bind function then use it. (RAW) */
457 	if (sk->sk_prot->bind) {
458 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
459 		goto out;
460 	}
461 	err = -EINVAL;
462 	if (addr_len < sizeof(struct sockaddr_in))
463 		goto out;
464 
465 	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
466 
467 	/* Not specified by any standard per-se, however it breaks too
468 	 * many applications when removed.  It is unfortunate since
469 	 * allowing applications to make a non-local bind solves
470 	 * several problems with systems using dynamic addressing.
471 	 * (ie. your servers still start up even if your ISDN link
472 	 *  is temporarily down)
473 	 */
474 	err = -EADDRNOTAVAIL;
475 	if (!sysctl_ip_nonlocal_bind &&
476 	    !(inet->freebind || inet->transparent) &&
477 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
478 	    chk_addr_ret != RTN_LOCAL &&
479 	    chk_addr_ret != RTN_MULTICAST &&
480 	    chk_addr_ret != RTN_BROADCAST)
481 		goto out;
482 
483 	snum = ntohs(addr->sin_port);
484 	err = -EACCES;
485 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
486 		goto out;
487 
488 	/*      We keep a pair of addresses. rcv_saddr is the one
489 	 *      used by hash lookups, and saddr is used for transmit.
490 	 *
491 	 *      In the BSD API these are the same except where it
492 	 *      would be illegal to use them (multicast/broadcast) in
493 	 *      which case the sending device address is used.
494 	 */
495 	lock_sock(sk);
496 
497 	/* Check these errors (active socket, double bind). */
498 	err = -EINVAL;
499 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
500 		goto out_release_sock;
501 
502 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
503 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
504 		inet->inet_saddr = 0;  /* Use device */
505 
506 	/* Make sure we are allowed to bind here. */
507 	if (sk->sk_prot->get_port(sk, snum)) {
508 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
509 		err = -EADDRINUSE;
510 		goto out_release_sock;
511 	}
512 
513 	if (inet->inet_rcv_saddr)
514 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
515 	if (snum)
516 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
517 	inet->inet_sport = htons(inet->inet_num);
518 	inet->inet_daddr = 0;
519 	inet->inet_dport = 0;
520 	sk_dst_reset(sk);
521 	err = 0;
522 out_release_sock:
523 	release_sock(sk);
524 out:
525 	return err;
526 }
527 EXPORT_SYMBOL(inet_bind);
528 
529 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
530 		       int addr_len, int flags)
531 {
532 	struct sock *sk = sock->sk;
533 
534 	if (addr_len < sizeof(uaddr->sa_family))
535 		return -EINVAL;
536 	if (uaddr->sa_family == AF_UNSPEC)
537 		return sk->sk_prot->disconnect(sk, flags);
538 
539 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
540 		return -EAGAIN;
541 	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
542 }
543 EXPORT_SYMBOL(inet_dgram_connect);
544 
545 static long inet_wait_for_connect(struct sock *sk, long timeo)
546 {
547 	DEFINE_WAIT(wait);
548 
549 	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
550 
551 	/* Basic assumption: if someone sets sk->sk_err, he _must_
552 	 * change state of the socket from TCP_SYN_*.
553 	 * Connect() does not allow to get error notifications
554 	 * without closing the socket.
555 	 */
556 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
557 		release_sock(sk);
558 		timeo = schedule_timeout(timeo);
559 		lock_sock(sk);
560 		if (signal_pending(current) || !timeo)
561 			break;
562 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
563 	}
564 	finish_wait(sk->sk_sleep, &wait);
565 	return timeo;
566 }
567 
568 /*
569  *	Connect to a remote host. There is regrettably still a little
570  *	TCP 'magic' in here.
571  */
572 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
573 			int addr_len, int flags)
574 {
575 	struct sock *sk = sock->sk;
576 	int err;
577 	long timeo;
578 
579 	if (addr_len < sizeof(uaddr->sa_family))
580 		return -EINVAL;
581 
582 	lock_sock(sk);
583 
584 	if (uaddr->sa_family == AF_UNSPEC) {
585 		err = sk->sk_prot->disconnect(sk, flags);
586 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
587 		goto out;
588 	}
589 
590 	switch (sock->state) {
591 	default:
592 		err = -EINVAL;
593 		goto out;
594 	case SS_CONNECTED:
595 		err = -EISCONN;
596 		goto out;
597 	case SS_CONNECTING:
598 		err = -EALREADY;
599 		/* Fall out of switch with err, set for this state */
600 		break;
601 	case SS_UNCONNECTED:
602 		err = -EISCONN;
603 		if (sk->sk_state != TCP_CLOSE)
604 			goto out;
605 
606 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
607 		if (err < 0)
608 			goto out;
609 
610 		sock->state = SS_CONNECTING;
611 
612 		/* Just entered SS_CONNECTING state; the only
613 		 * difference is that return value in non-blocking
614 		 * case is EINPROGRESS, rather than EALREADY.
615 		 */
616 		err = -EINPROGRESS;
617 		break;
618 	}
619 
620 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
621 
622 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
623 		/* Error code is set above */
624 		if (!timeo || !inet_wait_for_connect(sk, timeo))
625 			goto out;
626 
627 		err = sock_intr_errno(timeo);
628 		if (signal_pending(current))
629 			goto out;
630 	}
631 
632 	/* Connection was closed by RST, timeout, ICMP error
633 	 * or another process disconnected us.
634 	 */
635 	if (sk->sk_state == TCP_CLOSE)
636 		goto sock_error;
637 
638 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
639 	 * and error was received after socket entered established state.
640 	 * Hence, it is handled normally after connect() return successfully.
641 	 */
642 
643 	sock->state = SS_CONNECTED;
644 	err = 0;
645 out:
646 	release_sock(sk);
647 	return err;
648 
649 sock_error:
650 	err = sock_error(sk) ? : -ECONNABORTED;
651 	sock->state = SS_UNCONNECTED;
652 	if (sk->sk_prot->disconnect(sk, flags))
653 		sock->state = SS_DISCONNECTING;
654 	goto out;
655 }
656 EXPORT_SYMBOL(inet_stream_connect);
657 
658 /*
659  *	Accept a pending connection. The TCP layer now gives BSD semantics.
660  */
661 
662 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
663 {
664 	struct sock *sk1 = sock->sk;
665 	int err = -EINVAL;
666 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
667 
668 	if (!sk2)
669 		goto do_err;
670 
671 	lock_sock(sk2);
672 
673 	WARN_ON(!((1 << sk2->sk_state) &
674 		  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
675 
676 	sock_graft(sk2, newsock);
677 
678 	newsock->state = SS_CONNECTED;
679 	err = 0;
680 	release_sock(sk2);
681 do_err:
682 	return err;
683 }
684 EXPORT_SYMBOL(inet_accept);
685 
686 
687 /*
688  *	This does both peername and sockname.
689  */
690 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
691 			int *uaddr_len, int peer)
692 {
693 	struct sock *sk		= sock->sk;
694 	struct inet_sock *inet	= inet_sk(sk);
695 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
696 
697 	sin->sin_family = AF_INET;
698 	if (peer) {
699 		if (!inet->inet_dport ||
700 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
701 		     peer == 1))
702 			return -ENOTCONN;
703 		sin->sin_port = inet->inet_dport;
704 		sin->sin_addr.s_addr = inet->inet_daddr;
705 	} else {
706 		__be32 addr = inet->inet_rcv_saddr;
707 		if (!addr)
708 			addr = inet->inet_saddr;
709 		sin->sin_port = inet->inet_sport;
710 		sin->sin_addr.s_addr = addr;
711 	}
712 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
713 	*uaddr_len = sizeof(*sin);
714 	return 0;
715 }
716 EXPORT_SYMBOL(inet_getname);
717 
718 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
719 		 size_t size)
720 {
721 	struct sock *sk = sock->sk;
722 
723 	/* We may need to bind the socket. */
724 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
725 		return -EAGAIN;
726 
727 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
728 }
729 EXPORT_SYMBOL(inet_sendmsg);
730 
731 
732 static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
733 			     size_t size, int flags)
734 {
735 	struct sock *sk = sock->sk;
736 
737 	/* We may need to bind the socket. */
738 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
739 		return -EAGAIN;
740 
741 	if (sk->sk_prot->sendpage)
742 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
743 	return sock_no_sendpage(sock, page, offset, size, flags);
744 }
745 
746 
747 int inet_shutdown(struct socket *sock, int how)
748 {
749 	struct sock *sk = sock->sk;
750 	int err = 0;
751 
752 	/* This should really check to make sure
753 	 * the socket is a TCP socket. (WHY AC...)
754 	 */
755 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
756 		       1->2 bit 2 snds.
757 		       2->3 */
758 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
759 		return -EINVAL;
760 
761 	lock_sock(sk);
762 	if (sock->state == SS_CONNECTING) {
763 		if ((1 << sk->sk_state) &
764 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
765 			sock->state = SS_DISCONNECTING;
766 		else
767 			sock->state = SS_CONNECTED;
768 	}
769 
770 	switch (sk->sk_state) {
771 	case TCP_CLOSE:
772 		err = -ENOTCONN;
773 		/* Hack to wake up other listeners, who can poll for
774 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
775 	default:
776 		sk->sk_shutdown |= how;
777 		if (sk->sk_prot->shutdown)
778 			sk->sk_prot->shutdown(sk, how);
779 		break;
780 
781 	/* Remaining two branches are temporary solution for missing
782 	 * close() in multithreaded environment. It is _not_ a good idea,
783 	 * but we have no choice until close() is repaired at VFS level.
784 	 */
785 	case TCP_LISTEN:
786 		if (!(how & RCV_SHUTDOWN))
787 			break;
788 		/* Fall through */
789 	case TCP_SYN_SENT:
790 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
791 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
792 		break;
793 	}
794 
795 	/* Wake up anyone sleeping in poll. */
796 	sk->sk_state_change(sk);
797 	release_sock(sk);
798 	return err;
799 }
800 EXPORT_SYMBOL(inet_shutdown);
801 
802 /*
803  *	ioctl() calls you can issue on an INET socket. Most of these are
804  *	device configuration and stuff and very rarely used. Some ioctls
805  *	pass on to the socket itself.
806  *
807  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
808  *	loads the devconfigure module does its configuring and unloads it.
809  *	There's a good 20K of config code hanging around the kernel.
810  */
811 
812 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
813 {
814 	struct sock *sk = sock->sk;
815 	int err = 0;
816 	struct net *net = sock_net(sk);
817 
818 	switch (cmd) {
819 	case SIOCGSTAMP:
820 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
821 		break;
822 	case SIOCGSTAMPNS:
823 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
824 		break;
825 	case SIOCADDRT:
826 	case SIOCDELRT:
827 	case SIOCRTMSG:
828 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
829 		break;
830 	case SIOCDARP:
831 	case SIOCGARP:
832 	case SIOCSARP:
833 		err = arp_ioctl(net, cmd, (void __user *)arg);
834 		break;
835 	case SIOCGIFADDR:
836 	case SIOCSIFADDR:
837 	case SIOCGIFBRDADDR:
838 	case SIOCSIFBRDADDR:
839 	case SIOCGIFNETMASK:
840 	case SIOCSIFNETMASK:
841 	case SIOCGIFDSTADDR:
842 	case SIOCSIFDSTADDR:
843 	case SIOCSIFPFLAGS:
844 	case SIOCGIFPFLAGS:
845 	case SIOCSIFFLAGS:
846 		err = devinet_ioctl(net, cmd, (void __user *)arg);
847 		break;
848 	default:
849 		if (sk->sk_prot->ioctl)
850 			err = sk->sk_prot->ioctl(sk, cmd, arg);
851 		else
852 			err = -ENOIOCTLCMD;
853 		break;
854 	}
855 	return err;
856 }
857 EXPORT_SYMBOL(inet_ioctl);
858 
859 const struct proto_ops inet_stream_ops = {
860 	.family		   = PF_INET,
861 	.owner		   = THIS_MODULE,
862 	.release	   = inet_release,
863 	.bind		   = inet_bind,
864 	.connect	   = inet_stream_connect,
865 	.socketpair	   = sock_no_socketpair,
866 	.accept		   = inet_accept,
867 	.getname	   = inet_getname,
868 	.poll		   = tcp_poll,
869 	.ioctl		   = inet_ioctl,
870 	.listen		   = inet_listen,
871 	.shutdown	   = inet_shutdown,
872 	.setsockopt	   = sock_common_setsockopt,
873 	.getsockopt	   = sock_common_getsockopt,
874 	.sendmsg	   = tcp_sendmsg,
875 	.recvmsg	   = sock_common_recvmsg,
876 	.mmap		   = sock_no_mmap,
877 	.sendpage	   = tcp_sendpage,
878 	.splice_read	   = tcp_splice_read,
879 #ifdef CONFIG_COMPAT
880 	.compat_setsockopt = compat_sock_common_setsockopt,
881 	.compat_getsockopt = compat_sock_common_getsockopt,
882 #endif
883 };
884 EXPORT_SYMBOL(inet_stream_ops);
885 
886 const struct proto_ops inet_dgram_ops = {
887 	.family		   = PF_INET,
888 	.owner		   = THIS_MODULE,
889 	.release	   = inet_release,
890 	.bind		   = inet_bind,
891 	.connect	   = inet_dgram_connect,
892 	.socketpair	   = sock_no_socketpair,
893 	.accept		   = sock_no_accept,
894 	.getname	   = inet_getname,
895 	.poll		   = udp_poll,
896 	.ioctl		   = inet_ioctl,
897 	.listen		   = sock_no_listen,
898 	.shutdown	   = inet_shutdown,
899 	.setsockopt	   = sock_common_setsockopt,
900 	.getsockopt	   = sock_common_getsockopt,
901 	.sendmsg	   = inet_sendmsg,
902 	.recvmsg	   = sock_common_recvmsg,
903 	.mmap		   = sock_no_mmap,
904 	.sendpage	   = inet_sendpage,
905 #ifdef CONFIG_COMPAT
906 	.compat_setsockopt = compat_sock_common_setsockopt,
907 	.compat_getsockopt = compat_sock_common_getsockopt,
908 #endif
909 };
910 EXPORT_SYMBOL(inet_dgram_ops);
911 
912 /*
913  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
914  * udp_poll
915  */
916 static const struct proto_ops inet_sockraw_ops = {
917 	.family		   = PF_INET,
918 	.owner		   = THIS_MODULE,
919 	.release	   = inet_release,
920 	.bind		   = inet_bind,
921 	.connect	   = inet_dgram_connect,
922 	.socketpair	   = sock_no_socketpair,
923 	.accept		   = sock_no_accept,
924 	.getname	   = inet_getname,
925 	.poll		   = datagram_poll,
926 	.ioctl		   = inet_ioctl,
927 	.listen		   = sock_no_listen,
928 	.shutdown	   = inet_shutdown,
929 	.setsockopt	   = sock_common_setsockopt,
930 	.getsockopt	   = sock_common_getsockopt,
931 	.sendmsg	   = inet_sendmsg,
932 	.recvmsg	   = sock_common_recvmsg,
933 	.mmap		   = sock_no_mmap,
934 	.sendpage	   = inet_sendpage,
935 #ifdef CONFIG_COMPAT
936 	.compat_setsockopt = compat_sock_common_setsockopt,
937 	.compat_getsockopt = compat_sock_common_getsockopt,
938 #endif
939 };
940 
941 static const struct net_proto_family inet_family_ops = {
942 	.family = PF_INET,
943 	.create = inet_create,
944 	.owner	= THIS_MODULE,
945 };
946 
947 /* Upon startup we insert all the elements in inetsw_array[] into
948  * the linked list inetsw.
949  */
950 static struct inet_protosw inetsw_array[] =
951 {
952 	{
953 		.type =       SOCK_STREAM,
954 		.protocol =   IPPROTO_TCP,
955 		.prot =       &tcp_prot,
956 		.ops =        &inet_stream_ops,
957 		.no_check =   0,
958 		.flags =      INET_PROTOSW_PERMANENT |
959 			      INET_PROTOSW_ICSK,
960 	},
961 
962 	{
963 		.type =       SOCK_DGRAM,
964 		.protocol =   IPPROTO_UDP,
965 		.prot =       &udp_prot,
966 		.ops =        &inet_dgram_ops,
967 		.no_check =   UDP_CSUM_DEFAULT,
968 		.flags =      INET_PROTOSW_PERMANENT,
969        },
970 
971 
972        {
973 	       .type =       SOCK_RAW,
974 	       .protocol =   IPPROTO_IP,	/* wild card */
975 	       .prot =       &raw_prot,
976 	       .ops =        &inet_sockraw_ops,
977 	       .no_check =   UDP_CSUM_DEFAULT,
978 	       .flags =      INET_PROTOSW_REUSE,
979        }
980 };
981 
982 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
983 
984 void inet_register_protosw(struct inet_protosw *p)
985 {
986 	struct list_head *lh;
987 	struct inet_protosw *answer;
988 	int protocol = p->protocol;
989 	struct list_head *last_perm;
990 
991 	spin_lock_bh(&inetsw_lock);
992 
993 	if (p->type >= SOCK_MAX)
994 		goto out_illegal;
995 
996 	/* If we are trying to override a permanent protocol, bail. */
997 	answer = NULL;
998 	last_perm = &inetsw[p->type];
999 	list_for_each(lh, &inetsw[p->type]) {
1000 		answer = list_entry(lh, struct inet_protosw, list);
1001 
1002 		/* Check only the non-wild match. */
1003 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1004 			if (protocol == answer->protocol)
1005 				break;
1006 			last_perm = lh;
1007 		}
1008 
1009 		answer = NULL;
1010 	}
1011 	if (answer)
1012 		goto out_permanent;
1013 
1014 	/* Add the new entry after the last permanent entry if any, so that
1015 	 * the new entry does not override a permanent entry when matched with
1016 	 * a wild-card protocol. But it is allowed to override any existing
1017 	 * non-permanent entry.  This means that when we remove this entry, the
1018 	 * system automatically returns to the old behavior.
1019 	 */
1020 	list_add_rcu(&p->list, last_perm);
1021 out:
1022 	spin_unlock_bh(&inetsw_lock);
1023 
1024 	return;
1025 
1026 out_permanent:
1027 	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1028 	       protocol);
1029 	goto out;
1030 
1031 out_illegal:
1032 	printk(KERN_ERR
1033 	       "Ignoring attempt to register invalid socket type %d.\n",
1034 	       p->type);
1035 	goto out;
1036 }
1037 EXPORT_SYMBOL(inet_register_protosw);
1038 
1039 void inet_unregister_protosw(struct inet_protosw *p)
1040 {
1041 	if (INET_PROTOSW_PERMANENT & p->flags) {
1042 		printk(KERN_ERR
1043 		       "Attempt to unregister permanent protocol %d.\n",
1044 		       p->protocol);
1045 	} else {
1046 		spin_lock_bh(&inetsw_lock);
1047 		list_del_rcu(&p->list);
1048 		spin_unlock_bh(&inetsw_lock);
1049 
1050 		synchronize_net();
1051 	}
1052 }
1053 EXPORT_SYMBOL(inet_unregister_protosw);
1054 
1055 /*
1056  *      Shall we try to damage output packets if routing dev changes?
1057  */
1058 
1059 int sysctl_ip_dynaddr __read_mostly;
1060 
1061 static int inet_sk_reselect_saddr(struct sock *sk)
1062 {
1063 	struct inet_sock *inet = inet_sk(sk);
1064 	int err;
1065 	struct rtable *rt;
1066 	__be32 old_saddr = inet->inet_saddr;
1067 	__be32 new_saddr;
1068 	__be32 daddr = inet->inet_daddr;
1069 
1070 	if (inet->opt && inet->opt->srr)
1071 		daddr = inet->opt->faddr;
1072 
1073 	/* Query new route. */
1074 	err = ip_route_connect(&rt, daddr, 0,
1075 			       RT_CONN_FLAGS(sk),
1076 			       sk->sk_bound_dev_if,
1077 			       sk->sk_protocol,
1078 			       inet->inet_sport, inet->inet_dport, sk, 0);
1079 	if (err)
1080 		return err;
1081 
1082 	sk_setup_caps(sk, &rt->u.dst);
1083 
1084 	new_saddr = rt->rt_src;
1085 
1086 	if (new_saddr == old_saddr)
1087 		return 0;
1088 
1089 	if (sysctl_ip_dynaddr > 1) {
1090 		printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1091 		       __func__, &old_saddr, &new_saddr);
1092 	}
1093 
1094 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1095 
1096 	/*
1097 	 * XXX The only one ugly spot where we need to
1098 	 * XXX really change the sockets identity after
1099 	 * XXX it has entered the hashes. -DaveM
1100 	 *
1101 	 * Besides that, it does not check for connection
1102 	 * uniqueness. Wait for troubles.
1103 	 */
1104 	__sk_prot_rehash(sk);
1105 	return 0;
1106 }
1107 
1108 int inet_sk_rebuild_header(struct sock *sk)
1109 {
1110 	struct inet_sock *inet = inet_sk(sk);
1111 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1112 	__be32 daddr;
1113 	int err;
1114 
1115 	/* Route is OK, nothing to do. */
1116 	if (rt)
1117 		return 0;
1118 
1119 	/* Reroute. */
1120 	daddr = inet->inet_daddr;
1121 	if (inet->opt && inet->opt->srr)
1122 		daddr = inet->opt->faddr;
1123 {
1124 	struct flowi fl = {
1125 		.oif = sk->sk_bound_dev_if,
1126 		.mark = sk->sk_mark,
1127 		.nl_u = {
1128 			.ip4_u = {
1129 				.daddr	= daddr,
1130 				.saddr	= inet->inet_saddr,
1131 				.tos	= RT_CONN_FLAGS(sk),
1132 			},
1133 		},
1134 		.proto = sk->sk_protocol,
1135 		.flags = inet_sk_flowi_flags(sk),
1136 		.uli_u = {
1137 			.ports = {
1138 				.sport = inet->inet_sport,
1139 				.dport = inet->inet_dport,
1140 			},
1141 		},
1142 	};
1143 
1144 	security_sk_classify_flow(sk, &fl);
1145 	err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0);
1146 }
1147 	if (!err)
1148 		sk_setup_caps(sk, &rt->u.dst);
1149 	else {
1150 		/* Routing failed... */
1151 		sk->sk_route_caps = 0;
1152 		/*
1153 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1154 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1155 		 */
1156 		if (!sysctl_ip_dynaddr ||
1157 		    sk->sk_state != TCP_SYN_SENT ||
1158 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1159 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1160 			sk->sk_err_soft = -err;
1161 	}
1162 
1163 	return err;
1164 }
1165 EXPORT_SYMBOL(inet_sk_rebuild_header);
1166 
1167 static int inet_gso_send_check(struct sk_buff *skb)
1168 {
1169 	struct iphdr *iph;
1170 	const struct net_protocol *ops;
1171 	int proto;
1172 	int ihl;
1173 	int err = -EINVAL;
1174 
1175 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1176 		goto out;
1177 
1178 	iph = ip_hdr(skb);
1179 	ihl = iph->ihl * 4;
1180 	if (ihl < sizeof(*iph))
1181 		goto out;
1182 
1183 	if (unlikely(!pskb_may_pull(skb, ihl)))
1184 		goto out;
1185 
1186 	__skb_pull(skb, ihl);
1187 	skb_reset_transport_header(skb);
1188 	iph = ip_hdr(skb);
1189 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1190 	err = -EPROTONOSUPPORT;
1191 
1192 	rcu_read_lock();
1193 	ops = rcu_dereference(inet_protos[proto]);
1194 	if (likely(ops && ops->gso_send_check))
1195 		err = ops->gso_send_check(skb);
1196 	rcu_read_unlock();
1197 
1198 out:
1199 	return err;
1200 }
1201 
1202 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
1203 {
1204 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1205 	struct iphdr *iph;
1206 	const struct net_protocol *ops;
1207 	int proto;
1208 	int ihl;
1209 	int id;
1210 	unsigned int offset = 0;
1211 
1212 	if (!(features & NETIF_F_V4_CSUM))
1213 		features &= ~NETIF_F_SG;
1214 
1215 	if (unlikely(skb_shinfo(skb)->gso_type &
1216 		     ~(SKB_GSO_TCPV4 |
1217 		       SKB_GSO_UDP |
1218 		       SKB_GSO_DODGY |
1219 		       SKB_GSO_TCP_ECN |
1220 		       0)))
1221 		goto out;
1222 
1223 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1224 		goto out;
1225 
1226 	iph = ip_hdr(skb);
1227 	ihl = iph->ihl * 4;
1228 	if (ihl < sizeof(*iph))
1229 		goto out;
1230 
1231 	if (unlikely(!pskb_may_pull(skb, ihl)))
1232 		goto out;
1233 
1234 	__skb_pull(skb, ihl);
1235 	skb_reset_transport_header(skb);
1236 	iph = ip_hdr(skb);
1237 	id = ntohs(iph->id);
1238 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1239 	segs = ERR_PTR(-EPROTONOSUPPORT);
1240 
1241 	rcu_read_lock();
1242 	ops = rcu_dereference(inet_protos[proto]);
1243 	if (likely(ops && ops->gso_segment))
1244 		segs = ops->gso_segment(skb, features);
1245 	rcu_read_unlock();
1246 
1247 	if (!segs || IS_ERR(segs))
1248 		goto out;
1249 
1250 	skb = segs;
1251 	do {
1252 		iph = ip_hdr(skb);
1253 		if (proto == IPPROTO_UDP) {
1254 			iph->id = htons(id);
1255 			iph->frag_off = htons(offset >> 3);
1256 			if (skb->next != NULL)
1257 				iph->frag_off |= htons(IP_MF);
1258 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1259 		} else
1260 			iph->id = htons(id++);
1261 		iph->tot_len = htons(skb->len - skb->mac_len);
1262 		iph->check = 0;
1263 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1264 	} while ((skb = skb->next));
1265 
1266 out:
1267 	return segs;
1268 }
1269 
1270 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1271 					 struct sk_buff *skb)
1272 {
1273 	const struct net_protocol *ops;
1274 	struct sk_buff **pp = NULL;
1275 	struct sk_buff *p;
1276 	struct iphdr *iph;
1277 	unsigned int hlen;
1278 	unsigned int off;
1279 	unsigned int id;
1280 	int flush = 1;
1281 	int proto;
1282 
1283 	off = skb_gro_offset(skb);
1284 	hlen = off + sizeof(*iph);
1285 	iph = skb_gro_header_fast(skb, off);
1286 	if (skb_gro_header_hard(skb, hlen)) {
1287 		iph = skb_gro_header_slow(skb, hlen, off);
1288 		if (unlikely(!iph))
1289 			goto out;
1290 	}
1291 
1292 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1293 
1294 	rcu_read_lock();
1295 	ops = rcu_dereference(inet_protos[proto]);
1296 	if (!ops || !ops->gro_receive)
1297 		goto out_unlock;
1298 
1299 	if (*(u8 *)iph != 0x45)
1300 		goto out_unlock;
1301 
1302 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1303 		goto out_unlock;
1304 
1305 	id = ntohl(*(u32 *)&iph->id);
1306 	flush = (u16)((ntohl(*(u32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1307 	id >>= 16;
1308 
1309 	for (p = *head; p; p = p->next) {
1310 		struct iphdr *iph2;
1311 
1312 		if (!NAPI_GRO_CB(p)->same_flow)
1313 			continue;
1314 
1315 		iph2 = ip_hdr(p);
1316 
1317 		if ((iph->protocol ^ iph2->protocol) |
1318 		    (iph->tos ^ iph2->tos) |
1319 		    (iph->saddr ^ iph2->saddr) |
1320 		    (iph->daddr ^ iph2->daddr)) {
1321 			NAPI_GRO_CB(p)->same_flow = 0;
1322 			continue;
1323 		}
1324 
1325 		/* All fields must match except length and checksum. */
1326 		NAPI_GRO_CB(p)->flush |=
1327 			(iph->ttl ^ iph2->ttl) |
1328 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1329 
1330 		NAPI_GRO_CB(p)->flush |= flush;
1331 	}
1332 
1333 	NAPI_GRO_CB(skb)->flush |= flush;
1334 	skb_gro_pull(skb, sizeof(*iph));
1335 	skb_set_transport_header(skb, skb_gro_offset(skb));
1336 
1337 	pp = ops->gro_receive(head, skb);
1338 
1339 out_unlock:
1340 	rcu_read_unlock();
1341 
1342 out:
1343 	NAPI_GRO_CB(skb)->flush |= flush;
1344 
1345 	return pp;
1346 }
1347 
1348 static int inet_gro_complete(struct sk_buff *skb)
1349 {
1350 	const struct net_protocol *ops;
1351 	struct iphdr *iph = ip_hdr(skb);
1352 	int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1353 	int err = -ENOSYS;
1354 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1355 
1356 	csum_replace2(&iph->check, iph->tot_len, newlen);
1357 	iph->tot_len = newlen;
1358 
1359 	rcu_read_lock();
1360 	ops = rcu_dereference(inet_protos[proto]);
1361 	if (WARN_ON(!ops || !ops->gro_complete))
1362 		goto out_unlock;
1363 
1364 	err = ops->gro_complete(skb);
1365 
1366 out_unlock:
1367 	rcu_read_unlock();
1368 
1369 	return err;
1370 }
1371 
1372 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1373 			 unsigned short type, unsigned char protocol,
1374 			 struct net *net)
1375 {
1376 	struct socket *sock;
1377 	int rc = sock_create_kern(family, type, protocol, &sock);
1378 
1379 	if (rc == 0) {
1380 		*sk = sock->sk;
1381 		(*sk)->sk_allocation = GFP_ATOMIC;
1382 		/*
1383 		 * Unhash it so that IP input processing does not even see it,
1384 		 * we do not wish this socket to see incoming packets.
1385 		 */
1386 		(*sk)->sk_prot->unhash(*sk);
1387 
1388 		sk_change_net(*sk, net);
1389 	}
1390 	return rc;
1391 }
1392 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1393 
1394 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1395 {
1396 	unsigned long res = 0;
1397 	int i;
1398 
1399 	for_each_possible_cpu(i) {
1400 		res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1401 		res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1402 	}
1403 	return res;
1404 }
1405 EXPORT_SYMBOL_GPL(snmp_fold_field);
1406 
1407 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize)
1408 {
1409 	BUG_ON(ptr == NULL);
1410 	ptr[0] = __alloc_percpu(mibsize, __alignof__(unsigned long long));
1411 	if (!ptr[0])
1412 		goto err0;
1413 	ptr[1] = __alloc_percpu(mibsize, __alignof__(unsigned long long));
1414 	if (!ptr[1])
1415 		goto err1;
1416 	return 0;
1417 err1:
1418 	free_percpu(ptr[0]);
1419 	ptr[0] = NULL;
1420 err0:
1421 	return -ENOMEM;
1422 }
1423 EXPORT_SYMBOL_GPL(snmp_mib_init);
1424 
1425 void snmp_mib_free(void __percpu *ptr[2])
1426 {
1427 	BUG_ON(ptr == NULL);
1428 	free_percpu(ptr[0]);
1429 	free_percpu(ptr[1]);
1430 	ptr[0] = ptr[1] = NULL;
1431 }
1432 EXPORT_SYMBOL_GPL(snmp_mib_free);
1433 
1434 #ifdef CONFIG_IP_MULTICAST
1435 static const struct net_protocol igmp_protocol = {
1436 	.handler =	igmp_rcv,
1437 	.netns_ok =	1,
1438 };
1439 #endif
1440 
1441 static const struct net_protocol tcp_protocol = {
1442 	.handler =	tcp_v4_rcv,
1443 	.err_handler =	tcp_v4_err,
1444 	.gso_send_check = tcp_v4_gso_send_check,
1445 	.gso_segment =	tcp_tso_segment,
1446 	.gro_receive =	tcp4_gro_receive,
1447 	.gro_complete =	tcp4_gro_complete,
1448 	.no_policy =	1,
1449 	.netns_ok =	1,
1450 };
1451 
1452 static const struct net_protocol udp_protocol = {
1453 	.handler =	udp_rcv,
1454 	.err_handler =	udp_err,
1455 	.gso_send_check = udp4_ufo_send_check,
1456 	.gso_segment = udp4_ufo_fragment,
1457 	.no_policy =	1,
1458 	.netns_ok =	1,
1459 };
1460 
1461 static const struct net_protocol icmp_protocol = {
1462 	.handler =	icmp_rcv,
1463 	.no_policy =	1,
1464 	.netns_ok =	1,
1465 };
1466 
1467 static __net_init int ipv4_mib_init_net(struct net *net)
1468 {
1469 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1470 			  sizeof(struct tcp_mib)) < 0)
1471 		goto err_tcp_mib;
1472 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1473 			  sizeof(struct ipstats_mib)) < 0)
1474 		goto err_ip_mib;
1475 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1476 			  sizeof(struct linux_mib)) < 0)
1477 		goto err_net_mib;
1478 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1479 			  sizeof(struct udp_mib)) < 0)
1480 		goto err_udp_mib;
1481 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1482 			  sizeof(struct udp_mib)) < 0)
1483 		goto err_udplite_mib;
1484 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1485 			  sizeof(struct icmp_mib)) < 0)
1486 		goto err_icmp_mib;
1487 	if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
1488 			  sizeof(struct icmpmsg_mib)) < 0)
1489 		goto err_icmpmsg_mib;
1490 
1491 	tcp_mib_init(net);
1492 	return 0;
1493 
1494 err_icmpmsg_mib:
1495 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1496 err_icmp_mib:
1497 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1498 err_udplite_mib:
1499 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1500 err_udp_mib:
1501 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1502 err_net_mib:
1503 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1504 err_ip_mib:
1505 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1506 err_tcp_mib:
1507 	return -ENOMEM;
1508 }
1509 
1510 static __net_exit void ipv4_mib_exit_net(struct net *net)
1511 {
1512 	snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
1513 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1514 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1515 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1516 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1517 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1518 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1519 }
1520 
1521 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1522 	.init = ipv4_mib_init_net,
1523 	.exit = ipv4_mib_exit_net,
1524 };
1525 
1526 static int __init init_ipv4_mibs(void)
1527 {
1528 	return register_pernet_subsys(&ipv4_mib_ops);
1529 }
1530 
1531 static int ipv4_proc_init(void);
1532 
1533 /*
1534  *	IP protocol layer initialiser
1535  */
1536 
1537 static struct packet_type ip_packet_type __read_mostly = {
1538 	.type = cpu_to_be16(ETH_P_IP),
1539 	.func = ip_rcv,
1540 	.gso_send_check = inet_gso_send_check,
1541 	.gso_segment = inet_gso_segment,
1542 	.gro_receive = inet_gro_receive,
1543 	.gro_complete = inet_gro_complete,
1544 };
1545 
1546 static int __init inet_init(void)
1547 {
1548 	struct sk_buff *dummy_skb;
1549 	struct inet_protosw *q;
1550 	struct list_head *r;
1551 	int rc = -EINVAL;
1552 
1553 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1554 
1555 	rc = proto_register(&tcp_prot, 1);
1556 	if (rc)
1557 		goto out;
1558 
1559 	rc = proto_register(&udp_prot, 1);
1560 	if (rc)
1561 		goto out_unregister_tcp_proto;
1562 
1563 	rc = proto_register(&raw_prot, 1);
1564 	if (rc)
1565 		goto out_unregister_udp_proto;
1566 
1567 	/*
1568 	 *	Tell SOCKET that we are alive...
1569 	 */
1570 
1571 	(void)sock_register(&inet_family_ops);
1572 
1573 #ifdef CONFIG_SYSCTL
1574 	ip_static_sysctl_init();
1575 #endif
1576 
1577 	/*
1578 	 *	Add all the base protocols.
1579 	 */
1580 
1581 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1582 		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1583 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1584 		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1585 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1586 		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1587 #ifdef CONFIG_IP_MULTICAST
1588 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1589 		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1590 #endif
1591 
1592 	/* Register the socket-side information for inet_create. */
1593 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1594 		INIT_LIST_HEAD(r);
1595 
1596 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1597 		inet_register_protosw(q);
1598 
1599 	/*
1600 	 *	Set the ARP module up
1601 	 */
1602 
1603 	arp_init();
1604 
1605 	/*
1606 	 *	Set the IP module up
1607 	 */
1608 
1609 	ip_init();
1610 
1611 	tcp_v4_init();
1612 
1613 	/* Setup TCP slab cache for open requests. */
1614 	tcp_init();
1615 
1616 	/* Setup UDP memory threshold */
1617 	udp_init();
1618 
1619 	/* Add UDP-Lite (RFC 3828) */
1620 	udplite4_register();
1621 
1622 	/*
1623 	 *	Set the ICMP layer up
1624 	 */
1625 
1626 	if (icmp_init() < 0)
1627 		panic("Failed to create the ICMP control socket.\n");
1628 
1629 	/*
1630 	 *	Initialise the multicast router
1631 	 */
1632 #if defined(CONFIG_IP_MROUTE)
1633 	if (ip_mr_init())
1634 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1635 #endif
1636 	/*
1637 	 *	Initialise per-cpu ipv4 mibs
1638 	 */
1639 
1640 	if (init_ipv4_mibs())
1641 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1642 
1643 	ipv4_proc_init();
1644 
1645 	ipfrag_init();
1646 
1647 	dev_add_pack(&ip_packet_type);
1648 
1649 	rc = 0;
1650 out:
1651 	return rc;
1652 out_unregister_udp_proto:
1653 	proto_unregister(&udp_prot);
1654 out_unregister_tcp_proto:
1655 	proto_unregister(&tcp_prot);
1656 	goto out;
1657 }
1658 
1659 fs_initcall(inet_init);
1660 
1661 /* ------------------------------------------------------------------------ */
1662 
1663 #ifdef CONFIG_PROC_FS
1664 static int __init ipv4_proc_init(void)
1665 {
1666 	int rc = 0;
1667 
1668 	if (raw_proc_init())
1669 		goto out_raw;
1670 	if (tcp4_proc_init())
1671 		goto out_tcp;
1672 	if (udp4_proc_init())
1673 		goto out_udp;
1674 	if (ip_misc_proc_init())
1675 		goto out_misc;
1676 out:
1677 	return rc;
1678 out_misc:
1679 	udp4_proc_exit();
1680 out_udp:
1681 	tcp4_proc_exit();
1682 out_tcp:
1683 	raw_proc_exit();
1684 out_raw:
1685 	rc = -ENOMEM;
1686 	goto out;
1687 }
1688 
1689 #else /* CONFIG_PROC_FS */
1690 static int __init ipv4_proc_init(void)
1691 {
1692 	return 0;
1693 }
1694 #endif /* CONFIG_PROC_FS */
1695 
1696 MODULE_ALIAS_NETPROTO(PF_INET);
1697 
1698