xref: /linux/net/ipv4/af_inet.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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(rcu_dereference_check(sk->sk_dst_cache, 1));
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 	inet->nodefrag = 0;
359 
360 	if (SOCK_RAW == sock->type) {
361 		inet->inet_num = protocol;
362 		if (IPPROTO_RAW == protocol)
363 			inet->hdrincl = 1;
364 	}
365 
366 	if (ipv4_config.no_pmtu_disc)
367 		inet->pmtudisc = IP_PMTUDISC_DONT;
368 	else
369 		inet->pmtudisc = IP_PMTUDISC_WANT;
370 
371 	inet->inet_id = 0;
372 
373 	sock_init_data(sock, sk);
374 
375 	sk->sk_destruct	   = inet_sock_destruct;
376 	sk->sk_protocol	   = protocol;
377 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
378 
379 	inet->uc_ttl	= -1;
380 	inet->mc_loop	= 1;
381 	inet->mc_ttl	= 1;
382 	inet->mc_all	= 1;
383 	inet->mc_index	= 0;
384 	inet->mc_list	= NULL;
385 
386 	sk_refcnt_debug_inc(sk);
387 
388 	if (inet->inet_num) {
389 		/* It assumes that any protocol which allows
390 		 * the user to assign a number at socket
391 		 * creation time automatically
392 		 * shares.
393 		 */
394 		inet->inet_sport = htons(inet->inet_num);
395 		/* Add to protocol hash chains. */
396 		sk->sk_prot->hash(sk);
397 	}
398 
399 	if (sk->sk_prot->init) {
400 		err = sk->sk_prot->init(sk);
401 		if (err)
402 			sk_common_release(sk);
403 	}
404 out:
405 	return err;
406 out_rcu_unlock:
407 	rcu_read_unlock();
408 	goto out;
409 }
410 
411 
412 /*
413  *	The peer socket should always be NULL (or else). When we call this
414  *	function we are destroying the object and from then on nobody
415  *	should refer to it.
416  */
417 int inet_release(struct socket *sock)
418 {
419 	struct sock *sk = sock->sk;
420 
421 	if (sk) {
422 		long timeout;
423 
424 		sock_rps_reset_flow(sk);
425 
426 		/* Applications forget to leave groups before exiting */
427 		ip_mc_drop_socket(sk);
428 
429 		/* If linger is set, we don't return until the close
430 		 * is complete.  Otherwise we return immediately. The
431 		 * actually closing is done the same either way.
432 		 *
433 		 * If the close is due to the process exiting, we never
434 		 * linger..
435 		 */
436 		timeout = 0;
437 		if (sock_flag(sk, SOCK_LINGER) &&
438 		    !(current->flags & PF_EXITING))
439 			timeout = sk->sk_lingertime;
440 		sock->sk = NULL;
441 		sk->sk_prot->close(sk, timeout);
442 	}
443 	return 0;
444 }
445 EXPORT_SYMBOL(inet_release);
446 
447 /* It is off by default, see below. */
448 int sysctl_ip_nonlocal_bind __read_mostly;
449 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
450 
451 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
452 {
453 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
454 	struct sock *sk = sock->sk;
455 	struct inet_sock *inet = inet_sk(sk);
456 	unsigned short snum;
457 	int chk_addr_ret;
458 	int err;
459 
460 	/* If the socket has its own bind function then use it. (RAW) */
461 	if (sk->sk_prot->bind) {
462 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
463 		goto out;
464 	}
465 	err = -EINVAL;
466 	if (addr_len < sizeof(struct sockaddr_in))
467 		goto out;
468 
469 	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
470 
471 	/* Not specified by any standard per-se, however it breaks too
472 	 * many applications when removed.  It is unfortunate since
473 	 * allowing applications to make a non-local bind solves
474 	 * several problems with systems using dynamic addressing.
475 	 * (ie. your servers still start up even if your ISDN link
476 	 *  is temporarily down)
477 	 */
478 	err = -EADDRNOTAVAIL;
479 	if (!sysctl_ip_nonlocal_bind &&
480 	    !(inet->freebind || inet->transparent) &&
481 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
482 	    chk_addr_ret != RTN_LOCAL &&
483 	    chk_addr_ret != RTN_MULTICAST &&
484 	    chk_addr_ret != RTN_BROADCAST)
485 		goto out;
486 
487 	snum = ntohs(addr->sin_port);
488 	err = -EACCES;
489 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
490 		goto out;
491 
492 	/*      We keep a pair of addresses. rcv_saddr is the one
493 	 *      used by hash lookups, and saddr is used for transmit.
494 	 *
495 	 *      In the BSD API these are the same except where it
496 	 *      would be illegal to use them (multicast/broadcast) in
497 	 *      which case the sending device address is used.
498 	 */
499 	lock_sock(sk);
500 
501 	/* Check these errors (active socket, double bind). */
502 	err = -EINVAL;
503 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
504 		goto out_release_sock;
505 
506 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
507 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
508 		inet->inet_saddr = 0;  /* Use device */
509 
510 	/* Make sure we are allowed to bind here. */
511 	if (sk->sk_prot->get_port(sk, snum)) {
512 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
513 		err = -EADDRINUSE;
514 		goto out_release_sock;
515 	}
516 
517 	if (inet->inet_rcv_saddr)
518 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
519 	if (snum)
520 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
521 	inet->inet_sport = htons(inet->inet_num);
522 	inet->inet_daddr = 0;
523 	inet->inet_dport = 0;
524 	sk_dst_reset(sk);
525 	err = 0;
526 out_release_sock:
527 	release_sock(sk);
528 out:
529 	return err;
530 }
531 EXPORT_SYMBOL(inet_bind);
532 
533 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
534 		       int addr_len, int flags)
535 {
536 	struct sock *sk = sock->sk;
537 
538 	if (addr_len < sizeof(uaddr->sa_family))
539 		return -EINVAL;
540 	if (uaddr->sa_family == AF_UNSPEC)
541 		return sk->sk_prot->disconnect(sk, flags);
542 
543 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
544 		return -EAGAIN;
545 	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
546 }
547 EXPORT_SYMBOL(inet_dgram_connect);
548 
549 static long inet_wait_for_connect(struct sock *sk, long timeo)
550 {
551 	DEFINE_WAIT(wait);
552 
553 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
554 
555 	/* Basic assumption: if someone sets sk->sk_err, he _must_
556 	 * change state of the socket from TCP_SYN_*.
557 	 * Connect() does not allow to get error notifications
558 	 * without closing the socket.
559 	 */
560 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
561 		release_sock(sk);
562 		timeo = schedule_timeout(timeo);
563 		lock_sock(sk);
564 		if (signal_pending(current) || !timeo)
565 			break;
566 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
567 	}
568 	finish_wait(sk_sleep(sk), &wait);
569 	return timeo;
570 }
571 
572 /*
573  *	Connect to a remote host. There is regrettably still a little
574  *	TCP 'magic' in here.
575  */
576 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
577 			int addr_len, int flags)
578 {
579 	struct sock *sk = sock->sk;
580 	int err;
581 	long timeo;
582 
583 	if (addr_len < sizeof(uaddr->sa_family))
584 		return -EINVAL;
585 
586 	lock_sock(sk);
587 
588 	if (uaddr->sa_family == AF_UNSPEC) {
589 		err = sk->sk_prot->disconnect(sk, flags);
590 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
591 		goto out;
592 	}
593 
594 	switch (sock->state) {
595 	default:
596 		err = -EINVAL;
597 		goto out;
598 	case SS_CONNECTED:
599 		err = -EISCONN;
600 		goto out;
601 	case SS_CONNECTING:
602 		err = -EALREADY;
603 		/* Fall out of switch with err, set for this state */
604 		break;
605 	case SS_UNCONNECTED:
606 		err = -EISCONN;
607 		if (sk->sk_state != TCP_CLOSE)
608 			goto out;
609 
610 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
611 		if (err < 0)
612 			goto out;
613 
614 		sock->state = SS_CONNECTING;
615 
616 		/* Just entered SS_CONNECTING state; the only
617 		 * difference is that return value in non-blocking
618 		 * case is EINPROGRESS, rather than EALREADY.
619 		 */
620 		err = -EINPROGRESS;
621 		break;
622 	}
623 
624 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
625 
626 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
627 		/* Error code is set above */
628 		if (!timeo || !inet_wait_for_connect(sk, timeo))
629 			goto out;
630 
631 		err = sock_intr_errno(timeo);
632 		if (signal_pending(current))
633 			goto out;
634 	}
635 
636 	/* Connection was closed by RST, timeout, ICMP error
637 	 * or another process disconnected us.
638 	 */
639 	if (sk->sk_state == TCP_CLOSE)
640 		goto sock_error;
641 
642 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
643 	 * and error was received after socket entered established state.
644 	 * Hence, it is handled normally after connect() return successfully.
645 	 */
646 
647 	sock->state = SS_CONNECTED;
648 	err = 0;
649 out:
650 	release_sock(sk);
651 	return err;
652 
653 sock_error:
654 	err = sock_error(sk) ? : -ECONNABORTED;
655 	sock->state = SS_UNCONNECTED;
656 	if (sk->sk_prot->disconnect(sk, flags))
657 		sock->state = SS_DISCONNECTING;
658 	goto out;
659 }
660 EXPORT_SYMBOL(inet_stream_connect);
661 
662 /*
663  *	Accept a pending connection. The TCP layer now gives BSD semantics.
664  */
665 
666 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
667 {
668 	struct sock *sk1 = sock->sk;
669 	int err = -EINVAL;
670 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
671 
672 	if (!sk2)
673 		goto do_err;
674 
675 	lock_sock(sk2);
676 
677 	WARN_ON(!((1 << sk2->sk_state) &
678 		  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
679 
680 	sock_graft(sk2, newsock);
681 
682 	newsock->state = SS_CONNECTED;
683 	err = 0;
684 	release_sock(sk2);
685 do_err:
686 	return err;
687 }
688 EXPORT_SYMBOL(inet_accept);
689 
690 
691 /*
692  *	This does both peername and sockname.
693  */
694 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
695 			int *uaddr_len, int peer)
696 {
697 	struct sock *sk		= sock->sk;
698 	struct inet_sock *inet	= inet_sk(sk);
699 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
700 
701 	sin->sin_family = AF_INET;
702 	if (peer) {
703 		if (!inet->inet_dport ||
704 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
705 		     peer == 1))
706 			return -ENOTCONN;
707 		sin->sin_port = inet->inet_dport;
708 		sin->sin_addr.s_addr = inet->inet_daddr;
709 	} else {
710 		__be32 addr = inet->inet_rcv_saddr;
711 		if (!addr)
712 			addr = inet->inet_saddr;
713 		sin->sin_port = inet->inet_sport;
714 		sin->sin_addr.s_addr = addr;
715 	}
716 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
717 	*uaddr_len = sizeof(*sin);
718 	return 0;
719 }
720 EXPORT_SYMBOL(inet_getname);
721 
722 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
723 		 size_t size)
724 {
725 	struct sock *sk = sock->sk;
726 
727 	sock_rps_record_flow(sk);
728 
729 	/* We may need to bind the socket. */
730 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
731 	    inet_autobind(sk))
732 		return -EAGAIN;
733 
734 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
735 }
736 EXPORT_SYMBOL(inet_sendmsg);
737 
738 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
739 		      size_t size, int flags)
740 {
741 	struct sock *sk = sock->sk;
742 
743 	sock_rps_record_flow(sk);
744 
745 	/* We may need to bind the socket. */
746 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
747 	    inet_autobind(sk))
748 		return -EAGAIN;
749 
750 	if (sk->sk_prot->sendpage)
751 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
752 	return sock_no_sendpage(sock, page, offset, size, flags);
753 }
754 EXPORT_SYMBOL(inet_sendpage);
755 
756 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
757 		 size_t size, int flags)
758 {
759 	struct sock *sk = sock->sk;
760 	int addr_len = 0;
761 	int err;
762 
763 	sock_rps_record_flow(sk);
764 
765 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
766 				   flags & ~MSG_DONTWAIT, &addr_len);
767 	if (err >= 0)
768 		msg->msg_namelen = addr_len;
769 	return err;
770 }
771 EXPORT_SYMBOL(inet_recvmsg);
772 
773 int inet_shutdown(struct socket *sock, int how)
774 {
775 	struct sock *sk = sock->sk;
776 	int err = 0;
777 
778 	/* This should really check to make sure
779 	 * the socket is a TCP socket. (WHY AC...)
780 	 */
781 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
782 		       1->2 bit 2 snds.
783 		       2->3 */
784 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
785 		return -EINVAL;
786 
787 	lock_sock(sk);
788 	if (sock->state == SS_CONNECTING) {
789 		if ((1 << sk->sk_state) &
790 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
791 			sock->state = SS_DISCONNECTING;
792 		else
793 			sock->state = SS_CONNECTED;
794 	}
795 
796 	switch (sk->sk_state) {
797 	case TCP_CLOSE:
798 		err = -ENOTCONN;
799 		/* Hack to wake up other listeners, who can poll for
800 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
801 	default:
802 		sk->sk_shutdown |= how;
803 		if (sk->sk_prot->shutdown)
804 			sk->sk_prot->shutdown(sk, how);
805 		break;
806 
807 	/* Remaining two branches are temporary solution for missing
808 	 * close() in multithreaded environment. It is _not_ a good idea,
809 	 * but we have no choice until close() is repaired at VFS level.
810 	 */
811 	case TCP_LISTEN:
812 		if (!(how & RCV_SHUTDOWN))
813 			break;
814 		/* Fall through */
815 	case TCP_SYN_SENT:
816 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
817 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
818 		break;
819 	}
820 
821 	/* Wake up anyone sleeping in poll. */
822 	sk->sk_state_change(sk);
823 	release_sock(sk);
824 	return err;
825 }
826 EXPORT_SYMBOL(inet_shutdown);
827 
828 /*
829  *	ioctl() calls you can issue on an INET socket. Most of these are
830  *	device configuration and stuff and very rarely used. Some ioctls
831  *	pass on to the socket itself.
832  *
833  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
834  *	loads the devconfigure module does its configuring and unloads it.
835  *	There's a good 20K of config code hanging around the kernel.
836  */
837 
838 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
839 {
840 	struct sock *sk = sock->sk;
841 	int err = 0;
842 	struct net *net = sock_net(sk);
843 
844 	switch (cmd) {
845 	case SIOCGSTAMP:
846 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
847 		break;
848 	case SIOCGSTAMPNS:
849 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
850 		break;
851 	case SIOCADDRT:
852 	case SIOCDELRT:
853 	case SIOCRTMSG:
854 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
855 		break;
856 	case SIOCDARP:
857 	case SIOCGARP:
858 	case SIOCSARP:
859 		err = arp_ioctl(net, cmd, (void __user *)arg);
860 		break;
861 	case SIOCGIFADDR:
862 	case SIOCSIFADDR:
863 	case SIOCGIFBRDADDR:
864 	case SIOCSIFBRDADDR:
865 	case SIOCGIFNETMASK:
866 	case SIOCSIFNETMASK:
867 	case SIOCGIFDSTADDR:
868 	case SIOCSIFDSTADDR:
869 	case SIOCSIFPFLAGS:
870 	case SIOCGIFPFLAGS:
871 	case SIOCSIFFLAGS:
872 		err = devinet_ioctl(net, cmd, (void __user *)arg);
873 		break;
874 	default:
875 		if (sk->sk_prot->ioctl)
876 			err = sk->sk_prot->ioctl(sk, cmd, arg);
877 		else
878 			err = -ENOIOCTLCMD;
879 		break;
880 	}
881 	return err;
882 }
883 EXPORT_SYMBOL(inet_ioctl);
884 
885 const struct proto_ops inet_stream_ops = {
886 	.family		   = PF_INET,
887 	.owner		   = THIS_MODULE,
888 	.release	   = inet_release,
889 	.bind		   = inet_bind,
890 	.connect	   = inet_stream_connect,
891 	.socketpair	   = sock_no_socketpair,
892 	.accept		   = inet_accept,
893 	.getname	   = inet_getname,
894 	.poll		   = tcp_poll,
895 	.ioctl		   = inet_ioctl,
896 	.listen		   = inet_listen,
897 	.shutdown	   = inet_shutdown,
898 	.setsockopt	   = sock_common_setsockopt,
899 	.getsockopt	   = sock_common_getsockopt,
900 	.sendmsg	   = inet_sendmsg,
901 	.recvmsg	   = inet_recvmsg,
902 	.mmap		   = sock_no_mmap,
903 	.sendpage	   = inet_sendpage,
904 	.splice_read	   = tcp_splice_read,
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_stream_ops);
911 
912 const struct proto_ops inet_dgram_ops = {
913 	.family		   = PF_INET,
914 	.owner		   = THIS_MODULE,
915 	.release	   = inet_release,
916 	.bind		   = inet_bind,
917 	.connect	   = inet_dgram_connect,
918 	.socketpair	   = sock_no_socketpair,
919 	.accept		   = sock_no_accept,
920 	.getname	   = inet_getname,
921 	.poll		   = udp_poll,
922 	.ioctl		   = inet_ioctl,
923 	.listen		   = sock_no_listen,
924 	.shutdown	   = inet_shutdown,
925 	.setsockopt	   = sock_common_setsockopt,
926 	.getsockopt	   = sock_common_getsockopt,
927 	.sendmsg	   = inet_sendmsg,
928 	.recvmsg	   = inet_recvmsg,
929 	.mmap		   = sock_no_mmap,
930 	.sendpage	   = inet_sendpage,
931 #ifdef CONFIG_COMPAT
932 	.compat_setsockopt = compat_sock_common_setsockopt,
933 	.compat_getsockopt = compat_sock_common_getsockopt,
934 #endif
935 };
936 EXPORT_SYMBOL(inet_dgram_ops);
937 
938 /*
939  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
940  * udp_poll
941  */
942 static const struct proto_ops inet_sockraw_ops = {
943 	.family		   = PF_INET,
944 	.owner		   = THIS_MODULE,
945 	.release	   = inet_release,
946 	.bind		   = inet_bind,
947 	.connect	   = inet_dgram_connect,
948 	.socketpair	   = sock_no_socketpair,
949 	.accept		   = sock_no_accept,
950 	.getname	   = inet_getname,
951 	.poll		   = datagram_poll,
952 	.ioctl		   = inet_ioctl,
953 	.listen		   = sock_no_listen,
954 	.shutdown	   = inet_shutdown,
955 	.setsockopt	   = sock_common_setsockopt,
956 	.getsockopt	   = sock_common_getsockopt,
957 	.sendmsg	   = inet_sendmsg,
958 	.recvmsg	   = inet_recvmsg,
959 	.mmap		   = sock_no_mmap,
960 	.sendpage	   = inet_sendpage,
961 #ifdef CONFIG_COMPAT
962 	.compat_setsockopt = compat_sock_common_setsockopt,
963 	.compat_getsockopt = compat_sock_common_getsockopt,
964 #endif
965 };
966 
967 static const struct net_proto_family inet_family_ops = {
968 	.family = PF_INET,
969 	.create = inet_create,
970 	.owner	= THIS_MODULE,
971 };
972 
973 /* Upon startup we insert all the elements in inetsw_array[] into
974  * the linked list inetsw.
975  */
976 static struct inet_protosw inetsw_array[] =
977 {
978 	{
979 		.type =       SOCK_STREAM,
980 		.protocol =   IPPROTO_TCP,
981 		.prot =       &tcp_prot,
982 		.ops =        &inet_stream_ops,
983 		.no_check =   0,
984 		.flags =      INET_PROTOSW_PERMANENT |
985 			      INET_PROTOSW_ICSK,
986 	},
987 
988 	{
989 		.type =       SOCK_DGRAM,
990 		.protocol =   IPPROTO_UDP,
991 		.prot =       &udp_prot,
992 		.ops =        &inet_dgram_ops,
993 		.no_check =   UDP_CSUM_DEFAULT,
994 		.flags =      INET_PROTOSW_PERMANENT,
995        },
996 
997 
998        {
999 	       .type =       SOCK_RAW,
1000 	       .protocol =   IPPROTO_IP,	/* wild card */
1001 	       .prot =       &raw_prot,
1002 	       .ops =        &inet_sockraw_ops,
1003 	       .no_check =   UDP_CSUM_DEFAULT,
1004 	       .flags =      INET_PROTOSW_REUSE,
1005        }
1006 };
1007 
1008 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1009 
1010 void inet_register_protosw(struct inet_protosw *p)
1011 {
1012 	struct list_head *lh;
1013 	struct inet_protosw *answer;
1014 	int protocol = p->protocol;
1015 	struct list_head *last_perm;
1016 
1017 	spin_lock_bh(&inetsw_lock);
1018 
1019 	if (p->type >= SOCK_MAX)
1020 		goto out_illegal;
1021 
1022 	/* If we are trying to override a permanent protocol, bail. */
1023 	answer = NULL;
1024 	last_perm = &inetsw[p->type];
1025 	list_for_each(lh, &inetsw[p->type]) {
1026 		answer = list_entry(lh, struct inet_protosw, list);
1027 
1028 		/* Check only the non-wild match. */
1029 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1030 			if (protocol == answer->protocol)
1031 				break;
1032 			last_perm = lh;
1033 		}
1034 
1035 		answer = NULL;
1036 	}
1037 	if (answer)
1038 		goto out_permanent;
1039 
1040 	/* Add the new entry after the last permanent entry if any, so that
1041 	 * the new entry does not override a permanent entry when matched with
1042 	 * a wild-card protocol. But it is allowed to override any existing
1043 	 * non-permanent entry.  This means that when we remove this entry, the
1044 	 * system automatically returns to the old behavior.
1045 	 */
1046 	list_add_rcu(&p->list, last_perm);
1047 out:
1048 	spin_unlock_bh(&inetsw_lock);
1049 
1050 	return;
1051 
1052 out_permanent:
1053 	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1054 	       protocol);
1055 	goto out;
1056 
1057 out_illegal:
1058 	printk(KERN_ERR
1059 	       "Ignoring attempt to register invalid socket type %d.\n",
1060 	       p->type);
1061 	goto out;
1062 }
1063 EXPORT_SYMBOL(inet_register_protosw);
1064 
1065 void inet_unregister_protosw(struct inet_protosw *p)
1066 {
1067 	if (INET_PROTOSW_PERMANENT & p->flags) {
1068 		printk(KERN_ERR
1069 		       "Attempt to unregister permanent protocol %d.\n",
1070 		       p->protocol);
1071 	} else {
1072 		spin_lock_bh(&inetsw_lock);
1073 		list_del_rcu(&p->list);
1074 		spin_unlock_bh(&inetsw_lock);
1075 
1076 		synchronize_net();
1077 	}
1078 }
1079 EXPORT_SYMBOL(inet_unregister_protosw);
1080 
1081 /*
1082  *      Shall we try to damage output packets if routing dev changes?
1083  */
1084 
1085 int sysctl_ip_dynaddr __read_mostly;
1086 
1087 static int inet_sk_reselect_saddr(struct sock *sk)
1088 {
1089 	struct inet_sock *inet = inet_sk(sk);
1090 	int err;
1091 	struct rtable *rt;
1092 	__be32 old_saddr = inet->inet_saddr;
1093 	__be32 new_saddr;
1094 	__be32 daddr = inet->inet_daddr;
1095 
1096 	if (inet->opt && inet->opt->srr)
1097 		daddr = inet->opt->faddr;
1098 
1099 	/* Query new route. */
1100 	err = ip_route_connect(&rt, daddr, 0,
1101 			       RT_CONN_FLAGS(sk),
1102 			       sk->sk_bound_dev_if,
1103 			       sk->sk_protocol,
1104 			       inet->inet_sport, inet->inet_dport, sk, 0);
1105 	if (err)
1106 		return err;
1107 
1108 	sk_setup_caps(sk, &rt->dst);
1109 
1110 	new_saddr = rt->rt_src;
1111 
1112 	if (new_saddr == old_saddr)
1113 		return 0;
1114 
1115 	if (sysctl_ip_dynaddr > 1) {
1116 		printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1117 		       __func__, &old_saddr, &new_saddr);
1118 	}
1119 
1120 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1121 
1122 	/*
1123 	 * XXX The only one ugly spot where we need to
1124 	 * XXX really change the sockets identity after
1125 	 * XXX it has entered the hashes. -DaveM
1126 	 *
1127 	 * Besides that, it does not check for connection
1128 	 * uniqueness. Wait for troubles.
1129 	 */
1130 	__sk_prot_rehash(sk);
1131 	return 0;
1132 }
1133 
1134 int inet_sk_rebuild_header(struct sock *sk)
1135 {
1136 	struct inet_sock *inet = inet_sk(sk);
1137 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1138 	__be32 daddr;
1139 	int err;
1140 
1141 	/* Route is OK, nothing to do. */
1142 	if (rt)
1143 		return 0;
1144 
1145 	/* Reroute. */
1146 	daddr = inet->inet_daddr;
1147 	if (inet->opt && inet->opt->srr)
1148 		daddr = inet->opt->faddr;
1149 {
1150 	struct flowi fl = {
1151 		.oif = sk->sk_bound_dev_if,
1152 		.mark = sk->sk_mark,
1153 		.nl_u = {
1154 			.ip4_u = {
1155 				.daddr	= daddr,
1156 				.saddr	= inet->inet_saddr,
1157 				.tos	= RT_CONN_FLAGS(sk),
1158 			},
1159 		},
1160 		.proto = sk->sk_protocol,
1161 		.flags = inet_sk_flowi_flags(sk),
1162 		.uli_u = {
1163 			.ports = {
1164 				.sport = inet->inet_sport,
1165 				.dport = inet->inet_dport,
1166 			},
1167 		},
1168 	};
1169 
1170 	security_sk_classify_flow(sk, &fl);
1171 	err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0);
1172 }
1173 	if (!err)
1174 		sk_setup_caps(sk, &rt->dst);
1175 	else {
1176 		/* Routing failed... */
1177 		sk->sk_route_caps = 0;
1178 		/*
1179 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1180 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1181 		 */
1182 		if (!sysctl_ip_dynaddr ||
1183 		    sk->sk_state != TCP_SYN_SENT ||
1184 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1185 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1186 			sk->sk_err_soft = -err;
1187 	}
1188 
1189 	return err;
1190 }
1191 EXPORT_SYMBOL(inet_sk_rebuild_header);
1192 
1193 static int inet_gso_send_check(struct sk_buff *skb)
1194 {
1195 	struct iphdr *iph;
1196 	const struct net_protocol *ops;
1197 	int proto;
1198 	int ihl;
1199 	int err = -EINVAL;
1200 
1201 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1202 		goto out;
1203 
1204 	iph = ip_hdr(skb);
1205 	ihl = iph->ihl * 4;
1206 	if (ihl < sizeof(*iph))
1207 		goto out;
1208 
1209 	if (unlikely(!pskb_may_pull(skb, ihl)))
1210 		goto out;
1211 
1212 	__skb_pull(skb, ihl);
1213 	skb_reset_transport_header(skb);
1214 	iph = ip_hdr(skb);
1215 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1216 	err = -EPROTONOSUPPORT;
1217 
1218 	rcu_read_lock();
1219 	ops = rcu_dereference(inet_protos[proto]);
1220 	if (likely(ops && ops->gso_send_check))
1221 		err = ops->gso_send_check(skb);
1222 	rcu_read_unlock();
1223 
1224 out:
1225 	return err;
1226 }
1227 
1228 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
1229 {
1230 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1231 	struct iphdr *iph;
1232 	const struct net_protocol *ops;
1233 	int proto;
1234 	int ihl;
1235 	int id;
1236 	unsigned int offset = 0;
1237 
1238 	if (!(features & NETIF_F_V4_CSUM))
1239 		features &= ~NETIF_F_SG;
1240 
1241 	if (unlikely(skb_shinfo(skb)->gso_type &
1242 		     ~(SKB_GSO_TCPV4 |
1243 		       SKB_GSO_UDP |
1244 		       SKB_GSO_DODGY |
1245 		       SKB_GSO_TCP_ECN |
1246 		       0)))
1247 		goto out;
1248 
1249 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1250 		goto out;
1251 
1252 	iph = ip_hdr(skb);
1253 	ihl = iph->ihl * 4;
1254 	if (ihl < sizeof(*iph))
1255 		goto out;
1256 
1257 	if (unlikely(!pskb_may_pull(skb, ihl)))
1258 		goto out;
1259 
1260 	__skb_pull(skb, ihl);
1261 	skb_reset_transport_header(skb);
1262 	iph = ip_hdr(skb);
1263 	id = ntohs(iph->id);
1264 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1265 	segs = ERR_PTR(-EPROTONOSUPPORT);
1266 
1267 	rcu_read_lock();
1268 	ops = rcu_dereference(inet_protos[proto]);
1269 	if (likely(ops && ops->gso_segment))
1270 		segs = ops->gso_segment(skb, features);
1271 	rcu_read_unlock();
1272 
1273 	if (!segs || IS_ERR(segs))
1274 		goto out;
1275 
1276 	skb = segs;
1277 	do {
1278 		iph = ip_hdr(skb);
1279 		if (proto == IPPROTO_UDP) {
1280 			iph->id = htons(id);
1281 			iph->frag_off = htons(offset >> 3);
1282 			if (skb->next != NULL)
1283 				iph->frag_off |= htons(IP_MF);
1284 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1285 		} else
1286 			iph->id = htons(id++);
1287 		iph->tot_len = htons(skb->len - skb->mac_len);
1288 		iph->check = 0;
1289 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1290 	} while ((skb = skb->next));
1291 
1292 out:
1293 	return segs;
1294 }
1295 
1296 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1297 					 struct sk_buff *skb)
1298 {
1299 	const struct net_protocol *ops;
1300 	struct sk_buff **pp = NULL;
1301 	struct sk_buff *p;
1302 	struct iphdr *iph;
1303 	unsigned int hlen;
1304 	unsigned int off;
1305 	unsigned int id;
1306 	int flush = 1;
1307 	int proto;
1308 
1309 	off = skb_gro_offset(skb);
1310 	hlen = off + sizeof(*iph);
1311 	iph = skb_gro_header_fast(skb, off);
1312 	if (skb_gro_header_hard(skb, hlen)) {
1313 		iph = skb_gro_header_slow(skb, hlen, off);
1314 		if (unlikely(!iph))
1315 			goto out;
1316 	}
1317 
1318 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1319 
1320 	rcu_read_lock();
1321 	ops = rcu_dereference(inet_protos[proto]);
1322 	if (!ops || !ops->gro_receive)
1323 		goto out_unlock;
1324 
1325 	if (*(u8 *)iph != 0x45)
1326 		goto out_unlock;
1327 
1328 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1329 		goto out_unlock;
1330 
1331 	id = ntohl(*(__be32 *)&iph->id);
1332 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1333 	id >>= 16;
1334 
1335 	for (p = *head; p; p = p->next) {
1336 		struct iphdr *iph2;
1337 
1338 		if (!NAPI_GRO_CB(p)->same_flow)
1339 			continue;
1340 
1341 		iph2 = ip_hdr(p);
1342 
1343 		if ((iph->protocol ^ iph2->protocol) |
1344 		    (iph->tos ^ iph2->tos) |
1345 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1346 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1347 			NAPI_GRO_CB(p)->same_flow = 0;
1348 			continue;
1349 		}
1350 
1351 		/* All fields must match except length and checksum. */
1352 		NAPI_GRO_CB(p)->flush |=
1353 			(iph->ttl ^ iph2->ttl) |
1354 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1355 
1356 		NAPI_GRO_CB(p)->flush |= flush;
1357 	}
1358 
1359 	NAPI_GRO_CB(skb)->flush |= flush;
1360 	skb_gro_pull(skb, sizeof(*iph));
1361 	skb_set_transport_header(skb, skb_gro_offset(skb));
1362 
1363 	pp = ops->gro_receive(head, skb);
1364 
1365 out_unlock:
1366 	rcu_read_unlock();
1367 
1368 out:
1369 	NAPI_GRO_CB(skb)->flush |= flush;
1370 
1371 	return pp;
1372 }
1373 
1374 static int inet_gro_complete(struct sk_buff *skb)
1375 {
1376 	const struct net_protocol *ops;
1377 	struct iphdr *iph = ip_hdr(skb);
1378 	int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1379 	int err = -ENOSYS;
1380 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1381 
1382 	csum_replace2(&iph->check, iph->tot_len, newlen);
1383 	iph->tot_len = newlen;
1384 
1385 	rcu_read_lock();
1386 	ops = rcu_dereference(inet_protos[proto]);
1387 	if (WARN_ON(!ops || !ops->gro_complete))
1388 		goto out_unlock;
1389 
1390 	err = ops->gro_complete(skb);
1391 
1392 out_unlock:
1393 	rcu_read_unlock();
1394 
1395 	return err;
1396 }
1397 
1398 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1399 			 unsigned short type, unsigned char protocol,
1400 			 struct net *net)
1401 {
1402 	struct socket *sock;
1403 	int rc = sock_create_kern(family, type, protocol, &sock);
1404 
1405 	if (rc == 0) {
1406 		*sk = sock->sk;
1407 		(*sk)->sk_allocation = GFP_ATOMIC;
1408 		/*
1409 		 * Unhash it so that IP input processing does not even see it,
1410 		 * we do not wish this socket to see incoming packets.
1411 		 */
1412 		(*sk)->sk_prot->unhash(*sk);
1413 
1414 		sk_change_net(*sk, net);
1415 	}
1416 	return rc;
1417 }
1418 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1419 
1420 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1421 {
1422 	unsigned long res = 0;
1423 	int i;
1424 
1425 	for_each_possible_cpu(i) {
1426 		res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1427 		res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1428 	}
1429 	return res;
1430 }
1431 EXPORT_SYMBOL_GPL(snmp_fold_field);
1432 
1433 #if BITS_PER_LONG==32
1434 
1435 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1436 {
1437 	u64 res = 0;
1438 	int cpu;
1439 
1440 	for_each_possible_cpu(cpu) {
1441 		void *bhptr, *userptr;
1442 		struct u64_stats_sync *syncp;
1443 		u64 v_bh, v_user;
1444 		unsigned int start;
1445 
1446 		/* first mib used by softirq context, we must use _bh() accessors */
1447 		bhptr = per_cpu_ptr(SNMP_STAT_BHPTR(mib), cpu);
1448 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1449 		do {
1450 			start = u64_stats_fetch_begin_bh(syncp);
1451 			v_bh = *(((u64 *) bhptr) + offt);
1452 		} while (u64_stats_fetch_retry_bh(syncp, start));
1453 
1454 		/* second mib used in USER context */
1455 		userptr = per_cpu_ptr(SNMP_STAT_USRPTR(mib), cpu);
1456 		syncp = (struct u64_stats_sync *)(userptr + syncp_offset);
1457 		do {
1458 			start = u64_stats_fetch_begin(syncp);
1459 			v_user = *(((u64 *) userptr) + offt);
1460 		} while (u64_stats_fetch_retry(syncp, start));
1461 
1462 		res += v_bh + v_user;
1463 	}
1464 	return res;
1465 }
1466 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1467 #endif
1468 
1469 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1470 {
1471 	BUG_ON(ptr == NULL);
1472 	ptr[0] = __alloc_percpu(mibsize, align);
1473 	if (!ptr[0])
1474 		goto err0;
1475 	ptr[1] = __alloc_percpu(mibsize, align);
1476 	if (!ptr[1])
1477 		goto err1;
1478 	return 0;
1479 err1:
1480 	free_percpu(ptr[0]);
1481 	ptr[0] = NULL;
1482 err0:
1483 	return -ENOMEM;
1484 }
1485 EXPORT_SYMBOL_GPL(snmp_mib_init);
1486 
1487 void snmp_mib_free(void __percpu *ptr[2])
1488 {
1489 	BUG_ON(ptr == NULL);
1490 	free_percpu(ptr[0]);
1491 	free_percpu(ptr[1]);
1492 	ptr[0] = ptr[1] = NULL;
1493 }
1494 EXPORT_SYMBOL_GPL(snmp_mib_free);
1495 
1496 #ifdef CONFIG_IP_MULTICAST
1497 static const struct net_protocol igmp_protocol = {
1498 	.handler =	igmp_rcv,
1499 	.netns_ok =	1,
1500 };
1501 #endif
1502 
1503 static const struct net_protocol tcp_protocol = {
1504 	.handler =	tcp_v4_rcv,
1505 	.err_handler =	tcp_v4_err,
1506 	.gso_send_check = tcp_v4_gso_send_check,
1507 	.gso_segment =	tcp_tso_segment,
1508 	.gro_receive =	tcp4_gro_receive,
1509 	.gro_complete =	tcp4_gro_complete,
1510 	.no_policy =	1,
1511 	.netns_ok =	1,
1512 };
1513 
1514 static const struct net_protocol udp_protocol = {
1515 	.handler =	udp_rcv,
1516 	.err_handler =	udp_err,
1517 	.gso_send_check = udp4_ufo_send_check,
1518 	.gso_segment = udp4_ufo_fragment,
1519 	.no_policy =	1,
1520 	.netns_ok =	1,
1521 };
1522 
1523 static const struct net_protocol icmp_protocol = {
1524 	.handler =	icmp_rcv,
1525 	.no_policy =	1,
1526 	.netns_ok =	1,
1527 };
1528 
1529 static __net_init int ipv4_mib_init_net(struct net *net)
1530 {
1531 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1532 			  sizeof(struct tcp_mib),
1533 			  __alignof__(struct tcp_mib)) < 0)
1534 		goto err_tcp_mib;
1535 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1536 			  sizeof(struct ipstats_mib),
1537 			  __alignof__(struct ipstats_mib)) < 0)
1538 		goto err_ip_mib;
1539 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1540 			  sizeof(struct linux_mib),
1541 			  __alignof__(struct linux_mib)) < 0)
1542 		goto err_net_mib;
1543 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1544 			  sizeof(struct udp_mib),
1545 			  __alignof__(struct udp_mib)) < 0)
1546 		goto err_udp_mib;
1547 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1548 			  sizeof(struct udp_mib),
1549 			  __alignof__(struct udp_mib)) < 0)
1550 		goto err_udplite_mib;
1551 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1552 			  sizeof(struct icmp_mib),
1553 			  __alignof__(struct icmp_mib)) < 0)
1554 		goto err_icmp_mib;
1555 	if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
1556 			  sizeof(struct icmpmsg_mib),
1557 			  __alignof__(struct icmpmsg_mib)) < 0)
1558 		goto err_icmpmsg_mib;
1559 
1560 	tcp_mib_init(net);
1561 	return 0;
1562 
1563 err_icmpmsg_mib:
1564 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1565 err_icmp_mib:
1566 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1567 err_udplite_mib:
1568 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1569 err_udp_mib:
1570 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1571 err_net_mib:
1572 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1573 err_ip_mib:
1574 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1575 err_tcp_mib:
1576 	return -ENOMEM;
1577 }
1578 
1579 static __net_exit void ipv4_mib_exit_net(struct net *net)
1580 {
1581 	snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
1582 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1583 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1584 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1585 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1586 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1587 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1588 }
1589 
1590 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1591 	.init = ipv4_mib_init_net,
1592 	.exit = ipv4_mib_exit_net,
1593 };
1594 
1595 static int __init init_ipv4_mibs(void)
1596 {
1597 	return register_pernet_subsys(&ipv4_mib_ops);
1598 }
1599 
1600 static int ipv4_proc_init(void);
1601 
1602 /*
1603  *	IP protocol layer initialiser
1604  */
1605 
1606 static struct packet_type ip_packet_type __read_mostly = {
1607 	.type = cpu_to_be16(ETH_P_IP),
1608 	.func = ip_rcv,
1609 	.gso_send_check = inet_gso_send_check,
1610 	.gso_segment = inet_gso_segment,
1611 	.gro_receive = inet_gro_receive,
1612 	.gro_complete = inet_gro_complete,
1613 };
1614 
1615 static int __init inet_init(void)
1616 {
1617 	struct sk_buff *dummy_skb;
1618 	struct inet_protosw *q;
1619 	struct list_head *r;
1620 	int rc = -EINVAL;
1621 
1622 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1623 
1624 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1625 	if (!sysctl_local_reserved_ports)
1626 		goto out;
1627 
1628 	rc = proto_register(&tcp_prot, 1);
1629 	if (rc)
1630 		goto out_free_reserved_ports;
1631 
1632 	rc = proto_register(&udp_prot, 1);
1633 	if (rc)
1634 		goto out_unregister_tcp_proto;
1635 
1636 	rc = proto_register(&raw_prot, 1);
1637 	if (rc)
1638 		goto out_unregister_udp_proto;
1639 
1640 	/*
1641 	 *	Tell SOCKET that we are alive...
1642 	 */
1643 
1644 	(void)sock_register(&inet_family_ops);
1645 
1646 #ifdef CONFIG_SYSCTL
1647 	ip_static_sysctl_init();
1648 #endif
1649 
1650 	/*
1651 	 *	Add all the base protocols.
1652 	 */
1653 
1654 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1655 		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1656 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1657 		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1658 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1659 		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1660 #ifdef CONFIG_IP_MULTICAST
1661 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1662 		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1663 #endif
1664 
1665 	/* Register the socket-side information for inet_create. */
1666 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1667 		INIT_LIST_HEAD(r);
1668 
1669 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1670 		inet_register_protosw(q);
1671 
1672 	/*
1673 	 *	Set the ARP module up
1674 	 */
1675 
1676 	arp_init();
1677 
1678 	/*
1679 	 *	Set the IP module up
1680 	 */
1681 
1682 	ip_init();
1683 
1684 	tcp_v4_init();
1685 
1686 	/* Setup TCP slab cache for open requests. */
1687 	tcp_init();
1688 
1689 	/* Setup UDP memory threshold */
1690 	udp_init();
1691 
1692 	/* Add UDP-Lite (RFC 3828) */
1693 	udplite4_register();
1694 
1695 	/*
1696 	 *	Set the ICMP layer up
1697 	 */
1698 
1699 	if (icmp_init() < 0)
1700 		panic("Failed to create the ICMP control socket.\n");
1701 
1702 	/*
1703 	 *	Initialise the multicast router
1704 	 */
1705 #if defined(CONFIG_IP_MROUTE)
1706 	if (ip_mr_init())
1707 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1708 #endif
1709 	/*
1710 	 *	Initialise per-cpu ipv4 mibs
1711 	 */
1712 
1713 	if (init_ipv4_mibs())
1714 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1715 
1716 	ipv4_proc_init();
1717 
1718 	ipfrag_init();
1719 
1720 	dev_add_pack(&ip_packet_type);
1721 
1722 	rc = 0;
1723 out:
1724 	return rc;
1725 out_unregister_udp_proto:
1726 	proto_unregister(&udp_prot);
1727 out_unregister_tcp_proto:
1728 	proto_unregister(&tcp_prot);
1729 out_free_reserved_ports:
1730 	kfree(sysctl_local_reserved_ports);
1731 	goto out;
1732 }
1733 
1734 fs_initcall(inet_init);
1735 
1736 /* ------------------------------------------------------------------------ */
1737 
1738 #ifdef CONFIG_PROC_FS
1739 static int __init ipv4_proc_init(void)
1740 {
1741 	int rc = 0;
1742 
1743 	if (raw_proc_init())
1744 		goto out_raw;
1745 	if (tcp4_proc_init())
1746 		goto out_tcp;
1747 	if (udp4_proc_init())
1748 		goto out_udp;
1749 	if (ip_misc_proc_init())
1750 		goto out_misc;
1751 out:
1752 	return rc;
1753 out_misc:
1754 	udp4_proc_exit();
1755 out_udp:
1756 	tcp4_proc_exit();
1757 out_tcp:
1758 	raw_proc_exit();
1759 out_raw:
1760 	rc = -ENOMEM;
1761 	goto out;
1762 }
1763 
1764 #else /* CONFIG_PROC_FS */
1765 static int __init ipv4_proc_init(void)
1766 {
1767 	return 0;
1768 }
1769 #endif /* CONFIG_PROC_FS */
1770 
1771 MODULE_ALIAS_NETPROTO(PF_INET);
1772 
1773