xref: /openbmc/linux/net/ipv4/af_inet.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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  */
231 void build_ehash_secret(void)
232 {
233 	u32 rnd;
234 
235 	do {
236 		get_random_bytes(&rnd, sizeof(rnd));
237 	} while (rnd == 0);
238 
239 	cmpxchg(&inet_ehash_secret, 0, rnd);
240 }
241 EXPORT_SYMBOL(build_ehash_secret);
242 
243 static inline int inet_netns_ok(struct net *net, int protocol)
244 {
245 	int hash;
246 	const struct net_protocol *ipprot;
247 
248 	if (net_eq(net, &init_net))
249 		return 1;
250 
251 	hash = protocol & (MAX_INET_PROTOS - 1);
252 	ipprot = rcu_dereference(inet_protos[hash]);
253 
254 	if (ipprot == NULL)
255 		/* raw IP is OK */
256 		return 1;
257 	return ipprot->netns_ok;
258 }
259 
260 /*
261  *	Create an inet socket.
262  */
263 
264 static int inet_create(struct net *net, struct socket *sock, int protocol,
265 		       int kern)
266 {
267 	struct sock *sk;
268 	struct inet_protosw *answer;
269 	struct inet_sock *inet;
270 	struct proto *answer_prot;
271 	unsigned char answer_flags;
272 	char answer_no_check;
273 	int try_loading_module = 0;
274 	int err;
275 
276 	if (unlikely(!inet_ehash_secret))
277 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
278 			build_ehash_secret();
279 
280 	sock->state = SS_UNCONNECTED;
281 
282 	/* Look for the requested type/protocol pair. */
283 lookup_protocol:
284 	err = -ESOCKTNOSUPPORT;
285 	rcu_read_lock();
286 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
287 
288 		err = 0;
289 		/* Check the non-wild match. */
290 		if (protocol == answer->protocol) {
291 			if (protocol != IPPROTO_IP)
292 				break;
293 		} else {
294 			/* Check for the two wild cases. */
295 			if (IPPROTO_IP == protocol) {
296 				protocol = answer->protocol;
297 				break;
298 			}
299 			if (IPPROTO_IP == answer->protocol)
300 				break;
301 		}
302 		err = -EPROTONOSUPPORT;
303 	}
304 
305 	if (unlikely(err)) {
306 		if (try_loading_module < 2) {
307 			rcu_read_unlock();
308 			/*
309 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
310 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
311 			 */
312 			if (++try_loading_module == 1)
313 				request_module("net-pf-%d-proto-%d-type-%d",
314 					       PF_INET, protocol, sock->type);
315 			/*
316 			 * Fall back to generic, e.g. net-pf-2-proto-132
317 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
318 			 */
319 			else
320 				request_module("net-pf-%d-proto-%d",
321 					       PF_INET, protocol);
322 			goto lookup_protocol;
323 		} else
324 			goto out_rcu_unlock;
325 	}
326 
327 	err = -EPERM;
328 	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
329 		goto out_rcu_unlock;
330 
331 	err = -EAFNOSUPPORT;
332 	if (!inet_netns_ok(net, protocol))
333 		goto out_rcu_unlock;
334 
335 	sock->ops = answer->ops;
336 	answer_prot = answer->prot;
337 	answer_no_check = answer->no_check;
338 	answer_flags = answer->flags;
339 	rcu_read_unlock();
340 
341 	WARN_ON(answer_prot->slab == NULL);
342 
343 	err = -ENOBUFS;
344 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
345 	if (sk == NULL)
346 		goto out;
347 
348 	err = 0;
349 	sk->sk_no_check = answer_no_check;
350 	if (INET_PROTOSW_REUSE & answer_flags)
351 		sk->sk_reuse = 1;
352 
353 	inet = inet_sk(sk);
354 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
355 
356 	inet->nodefrag = 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 		sock_rps_reset_flow(sk);
423 
424 		/* Applications forget to leave groups before exiting */
425 		ip_mc_drop_socket(sk);
426 
427 		/* If linger is set, we don't return until the close
428 		 * is complete.  Otherwise we return immediately. The
429 		 * actually closing is done the same either way.
430 		 *
431 		 * If the close is due to the process exiting, we never
432 		 * linger..
433 		 */
434 		timeout = 0;
435 		if (sock_flag(sk, SOCK_LINGER) &&
436 		    !(current->flags & PF_EXITING))
437 			timeout = sk->sk_lingertime;
438 		sock->sk = NULL;
439 		sk->sk_prot->close(sk, timeout);
440 	}
441 	return 0;
442 }
443 EXPORT_SYMBOL(inet_release);
444 
445 /* It is off by default, see below. */
446 int sysctl_ip_nonlocal_bind __read_mostly;
447 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
448 
449 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
450 {
451 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
452 	struct sock *sk = sock->sk;
453 	struct inet_sock *inet = inet_sk(sk);
454 	unsigned short snum;
455 	int chk_addr_ret;
456 	int err;
457 
458 	/* If the socket has its own bind function then use it. (RAW) */
459 	if (sk->sk_prot->bind) {
460 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
461 		goto out;
462 	}
463 	err = -EINVAL;
464 	if (addr_len < sizeof(struct sockaddr_in))
465 		goto out;
466 
467 	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
468 
469 	/* Not specified by any standard per-se, however it breaks too
470 	 * many applications when removed.  It is unfortunate since
471 	 * allowing applications to make a non-local bind solves
472 	 * several problems with systems using dynamic addressing.
473 	 * (ie. your servers still start up even if your ISDN link
474 	 *  is temporarily down)
475 	 */
476 	err = -EADDRNOTAVAIL;
477 	if (!sysctl_ip_nonlocal_bind &&
478 	    !(inet->freebind || inet->transparent) &&
479 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
480 	    chk_addr_ret != RTN_LOCAL &&
481 	    chk_addr_ret != RTN_MULTICAST &&
482 	    chk_addr_ret != RTN_BROADCAST)
483 		goto out;
484 
485 	snum = ntohs(addr->sin_port);
486 	err = -EACCES;
487 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
488 		goto out;
489 
490 	/*      We keep a pair of addresses. rcv_saddr is the one
491 	 *      used by hash lookups, and saddr is used for transmit.
492 	 *
493 	 *      In the BSD API these are the same except where it
494 	 *      would be illegal to use them (multicast/broadcast) in
495 	 *      which case the sending device address is used.
496 	 */
497 	lock_sock(sk);
498 
499 	/* Check these errors (active socket, double bind). */
500 	err = -EINVAL;
501 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
502 		goto out_release_sock;
503 
504 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
505 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
506 		inet->inet_saddr = 0;  /* Use device */
507 
508 	/* Make sure we are allowed to bind here. */
509 	if (sk->sk_prot->get_port(sk, snum)) {
510 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
511 		err = -EADDRINUSE;
512 		goto out_release_sock;
513 	}
514 
515 	if (inet->inet_rcv_saddr)
516 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
517 	if (snum)
518 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
519 	inet->inet_sport = htons(inet->inet_num);
520 	inet->inet_daddr = 0;
521 	inet->inet_dport = 0;
522 	sk_dst_reset(sk);
523 	err = 0;
524 out_release_sock:
525 	release_sock(sk);
526 out:
527 	return err;
528 }
529 EXPORT_SYMBOL(inet_bind);
530 
531 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
532 		       int addr_len, int flags)
533 {
534 	struct sock *sk = sock->sk;
535 
536 	if (addr_len < sizeof(uaddr->sa_family))
537 		return -EINVAL;
538 	if (uaddr->sa_family == AF_UNSPEC)
539 		return sk->sk_prot->disconnect(sk, flags);
540 
541 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
542 		return -EAGAIN;
543 	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
544 }
545 EXPORT_SYMBOL(inet_dgram_connect);
546 
547 static long inet_wait_for_connect(struct sock *sk, long timeo)
548 {
549 	DEFINE_WAIT(wait);
550 
551 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
552 
553 	/* Basic assumption: if someone sets sk->sk_err, he _must_
554 	 * change state of the socket from TCP_SYN_*.
555 	 * Connect() does not allow to get error notifications
556 	 * without closing the socket.
557 	 */
558 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
559 		release_sock(sk);
560 		timeo = schedule_timeout(timeo);
561 		lock_sock(sk);
562 		if (signal_pending(current) || !timeo)
563 			break;
564 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
565 	}
566 	finish_wait(sk_sleep(sk), &wait);
567 	return timeo;
568 }
569 
570 /*
571  *	Connect to a remote host. There is regrettably still a little
572  *	TCP 'magic' in here.
573  */
574 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
575 			int addr_len, int flags)
576 {
577 	struct sock *sk = sock->sk;
578 	int err;
579 	long timeo;
580 
581 	if (addr_len < sizeof(uaddr->sa_family))
582 		return -EINVAL;
583 
584 	lock_sock(sk);
585 
586 	if (uaddr->sa_family == AF_UNSPEC) {
587 		err = sk->sk_prot->disconnect(sk, flags);
588 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
589 		goto out;
590 	}
591 
592 	switch (sock->state) {
593 	default:
594 		err = -EINVAL;
595 		goto out;
596 	case SS_CONNECTED:
597 		err = -EISCONN;
598 		goto out;
599 	case SS_CONNECTING:
600 		err = -EALREADY;
601 		/* Fall out of switch with err, set for this state */
602 		break;
603 	case SS_UNCONNECTED:
604 		err = -EISCONN;
605 		if (sk->sk_state != TCP_CLOSE)
606 			goto out;
607 
608 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
609 		if (err < 0)
610 			goto out;
611 
612 		sock->state = SS_CONNECTING;
613 
614 		/* Just entered SS_CONNECTING state; the only
615 		 * difference is that return value in non-blocking
616 		 * case is EINPROGRESS, rather than EALREADY.
617 		 */
618 		err = -EINPROGRESS;
619 		break;
620 	}
621 
622 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
623 
624 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
625 		/* Error code is set above */
626 		if (!timeo || !inet_wait_for_connect(sk, timeo))
627 			goto out;
628 
629 		err = sock_intr_errno(timeo);
630 		if (signal_pending(current))
631 			goto out;
632 	}
633 
634 	/* Connection was closed by RST, timeout, ICMP error
635 	 * or another process disconnected us.
636 	 */
637 	if (sk->sk_state == TCP_CLOSE)
638 		goto sock_error;
639 
640 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
641 	 * and error was received after socket entered established state.
642 	 * Hence, it is handled normally after connect() return successfully.
643 	 */
644 
645 	sock->state = SS_CONNECTED;
646 	err = 0;
647 out:
648 	release_sock(sk);
649 	return err;
650 
651 sock_error:
652 	err = sock_error(sk) ? : -ECONNABORTED;
653 	sock->state = SS_UNCONNECTED;
654 	if (sk->sk_prot->disconnect(sk, flags))
655 		sock->state = SS_DISCONNECTING;
656 	goto out;
657 }
658 EXPORT_SYMBOL(inet_stream_connect);
659 
660 /*
661  *	Accept a pending connection. The TCP layer now gives BSD semantics.
662  */
663 
664 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
665 {
666 	struct sock *sk1 = sock->sk;
667 	int err = -EINVAL;
668 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
669 
670 	if (!sk2)
671 		goto do_err;
672 
673 	lock_sock(sk2);
674 
675 	WARN_ON(!((1 << sk2->sk_state) &
676 		  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
677 
678 	sock_graft(sk2, newsock);
679 
680 	newsock->state = SS_CONNECTED;
681 	err = 0;
682 	release_sock(sk2);
683 do_err:
684 	return err;
685 }
686 EXPORT_SYMBOL(inet_accept);
687 
688 
689 /*
690  *	This does both peername and sockname.
691  */
692 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
693 			int *uaddr_len, int peer)
694 {
695 	struct sock *sk		= sock->sk;
696 	struct inet_sock *inet	= inet_sk(sk);
697 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
698 
699 	sin->sin_family = AF_INET;
700 	if (peer) {
701 		if (!inet->inet_dport ||
702 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
703 		     peer == 1))
704 			return -ENOTCONN;
705 		sin->sin_port = inet->inet_dport;
706 		sin->sin_addr.s_addr = inet->inet_daddr;
707 	} else {
708 		__be32 addr = inet->inet_rcv_saddr;
709 		if (!addr)
710 			addr = inet->inet_saddr;
711 		sin->sin_port = inet->inet_sport;
712 		sin->sin_addr.s_addr = addr;
713 	}
714 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
715 	*uaddr_len = sizeof(*sin);
716 	return 0;
717 }
718 EXPORT_SYMBOL(inet_getname);
719 
720 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
721 		 size_t size)
722 {
723 	struct sock *sk = sock->sk;
724 
725 	sock_rps_record_flow(sk);
726 
727 	/* We may need to bind the socket. */
728 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
729 	    inet_autobind(sk))
730 		return -EAGAIN;
731 
732 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
733 }
734 EXPORT_SYMBOL(inet_sendmsg);
735 
736 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
737 		      size_t size, int flags)
738 {
739 	struct sock *sk = sock->sk;
740 
741 	sock_rps_record_flow(sk);
742 
743 	/* We may need to bind the socket. */
744 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
745 	    inet_autobind(sk))
746 		return -EAGAIN;
747 
748 	if (sk->sk_prot->sendpage)
749 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
750 	return sock_no_sendpage(sock, page, offset, size, flags);
751 }
752 EXPORT_SYMBOL(inet_sendpage);
753 
754 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
755 		 size_t size, int flags)
756 {
757 	struct sock *sk = sock->sk;
758 	int addr_len = 0;
759 	int err;
760 
761 	sock_rps_record_flow(sk);
762 
763 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
764 				   flags & ~MSG_DONTWAIT, &addr_len);
765 	if (err >= 0)
766 		msg->msg_namelen = addr_len;
767 	return err;
768 }
769 EXPORT_SYMBOL(inet_recvmsg);
770 
771 int inet_shutdown(struct socket *sock, int how)
772 {
773 	struct sock *sk = sock->sk;
774 	int err = 0;
775 
776 	/* This should really check to make sure
777 	 * the socket is a TCP socket. (WHY AC...)
778 	 */
779 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
780 		       1->2 bit 2 snds.
781 		       2->3 */
782 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
783 		return -EINVAL;
784 
785 	lock_sock(sk);
786 	if (sock->state == SS_CONNECTING) {
787 		if ((1 << sk->sk_state) &
788 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
789 			sock->state = SS_DISCONNECTING;
790 		else
791 			sock->state = SS_CONNECTED;
792 	}
793 
794 	switch (sk->sk_state) {
795 	case TCP_CLOSE:
796 		err = -ENOTCONN;
797 		/* Hack to wake up other listeners, who can poll for
798 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
799 	default:
800 		sk->sk_shutdown |= how;
801 		if (sk->sk_prot->shutdown)
802 			sk->sk_prot->shutdown(sk, how);
803 		break;
804 
805 	/* Remaining two branches are temporary solution for missing
806 	 * close() in multithreaded environment. It is _not_ a good idea,
807 	 * but we have no choice until close() is repaired at VFS level.
808 	 */
809 	case TCP_LISTEN:
810 		if (!(how & RCV_SHUTDOWN))
811 			break;
812 		/* Fall through */
813 	case TCP_SYN_SENT:
814 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
815 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
816 		break;
817 	}
818 
819 	/* Wake up anyone sleeping in poll. */
820 	sk->sk_state_change(sk);
821 	release_sock(sk);
822 	return err;
823 }
824 EXPORT_SYMBOL(inet_shutdown);
825 
826 /*
827  *	ioctl() calls you can issue on an INET socket. Most of these are
828  *	device configuration and stuff and very rarely used. Some ioctls
829  *	pass on to the socket itself.
830  *
831  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
832  *	loads the devconfigure module does its configuring and unloads it.
833  *	There's a good 20K of config code hanging around the kernel.
834  */
835 
836 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
837 {
838 	struct sock *sk = sock->sk;
839 	int err = 0;
840 	struct net *net = sock_net(sk);
841 
842 	switch (cmd) {
843 	case SIOCGSTAMP:
844 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
845 		break;
846 	case SIOCGSTAMPNS:
847 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
848 		break;
849 	case SIOCADDRT:
850 	case SIOCDELRT:
851 	case SIOCRTMSG:
852 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
853 		break;
854 	case SIOCDARP:
855 	case SIOCGARP:
856 	case SIOCSARP:
857 		err = arp_ioctl(net, cmd, (void __user *)arg);
858 		break;
859 	case SIOCGIFADDR:
860 	case SIOCSIFADDR:
861 	case SIOCGIFBRDADDR:
862 	case SIOCSIFBRDADDR:
863 	case SIOCGIFNETMASK:
864 	case SIOCSIFNETMASK:
865 	case SIOCGIFDSTADDR:
866 	case SIOCSIFDSTADDR:
867 	case SIOCSIFPFLAGS:
868 	case SIOCGIFPFLAGS:
869 	case SIOCSIFFLAGS:
870 		err = devinet_ioctl(net, cmd, (void __user *)arg);
871 		break;
872 	default:
873 		if (sk->sk_prot->ioctl)
874 			err = sk->sk_prot->ioctl(sk, cmd, arg);
875 		else
876 			err = -ENOIOCTLCMD;
877 		break;
878 	}
879 	return err;
880 }
881 EXPORT_SYMBOL(inet_ioctl);
882 
883 const struct proto_ops inet_stream_ops = {
884 	.family		   = PF_INET,
885 	.owner		   = THIS_MODULE,
886 	.release	   = inet_release,
887 	.bind		   = inet_bind,
888 	.connect	   = inet_stream_connect,
889 	.socketpair	   = sock_no_socketpair,
890 	.accept		   = inet_accept,
891 	.getname	   = inet_getname,
892 	.poll		   = tcp_poll,
893 	.ioctl		   = inet_ioctl,
894 	.listen		   = inet_listen,
895 	.shutdown	   = inet_shutdown,
896 	.setsockopt	   = sock_common_setsockopt,
897 	.getsockopt	   = sock_common_getsockopt,
898 	.sendmsg	   = inet_sendmsg,
899 	.recvmsg	   = inet_recvmsg,
900 	.mmap		   = sock_no_mmap,
901 	.sendpage	   = inet_sendpage,
902 	.splice_read	   = tcp_splice_read,
903 #ifdef CONFIG_COMPAT
904 	.compat_setsockopt = compat_sock_common_setsockopt,
905 	.compat_getsockopt = compat_sock_common_getsockopt,
906 #endif
907 };
908 EXPORT_SYMBOL(inet_stream_ops);
909 
910 const struct proto_ops inet_dgram_ops = {
911 	.family		   = PF_INET,
912 	.owner		   = THIS_MODULE,
913 	.release	   = inet_release,
914 	.bind		   = inet_bind,
915 	.connect	   = inet_dgram_connect,
916 	.socketpair	   = sock_no_socketpair,
917 	.accept		   = sock_no_accept,
918 	.getname	   = inet_getname,
919 	.poll		   = udp_poll,
920 	.ioctl		   = inet_ioctl,
921 	.listen		   = sock_no_listen,
922 	.shutdown	   = inet_shutdown,
923 	.setsockopt	   = sock_common_setsockopt,
924 	.getsockopt	   = sock_common_getsockopt,
925 	.sendmsg	   = inet_sendmsg,
926 	.recvmsg	   = inet_recvmsg,
927 	.mmap		   = sock_no_mmap,
928 	.sendpage	   = inet_sendpage,
929 #ifdef CONFIG_COMPAT
930 	.compat_setsockopt = compat_sock_common_setsockopt,
931 	.compat_getsockopt = compat_sock_common_getsockopt,
932 #endif
933 };
934 EXPORT_SYMBOL(inet_dgram_ops);
935 
936 /*
937  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
938  * udp_poll
939  */
940 static const struct proto_ops inet_sockraw_ops = {
941 	.family		   = PF_INET,
942 	.owner		   = THIS_MODULE,
943 	.release	   = inet_release,
944 	.bind		   = inet_bind,
945 	.connect	   = inet_dgram_connect,
946 	.socketpair	   = sock_no_socketpair,
947 	.accept		   = sock_no_accept,
948 	.getname	   = inet_getname,
949 	.poll		   = datagram_poll,
950 	.ioctl		   = inet_ioctl,
951 	.listen		   = sock_no_listen,
952 	.shutdown	   = inet_shutdown,
953 	.setsockopt	   = sock_common_setsockopt,
954 	.getsockopt	   = sock_common_getsockopt,
955 	.sendmsg	   = inet_sendmsg,
956 	.recvmsg	   = inet_recvmsg,
957 	.mmap		   = sock_no_mmap,
958 	.sendpage	   = inet_sendpage,
959 #ifdef CONFIG_COMPAT
960 	.compat_setsockopt = compat_sock_common_setsockopt,
961 	.compat_getsockopt = compat_sock_common_getsockopt,
962 #endif
963 };
964 
965 static const struct net_proto_family inet_family_ops = {
966 	.family = PF_INET,
967 	.create = inet_create,
968 	.owner	= THIS_MODULE,
969 };
970 
971 /* Upon startup we insert all the elements in inetsw_array[] into
972  * the linked list inetsw.
973  */
974 static struct inet_protosw inetsw_array[] =
975 {
976 	{
977 		.type =       SOCK_STREAM,
978 		.protocol =   IPPROTO_TCP,
979 		.prot =       &tcp_prot,
980 		.ops =        &inet_stream_ops,
981 		.no_check =   0,
982 		.flags =      INET_PROTOSW_PERMANENT |
983 			      INET_PROTOSW_ICSK,
984 	},
985 
986 	{
987 		.type =       SOCK_DGRAM,
988 		.protocol =   IPPROTO_UDP,
989 		.prot =       &udp_prot,
990 		.ops =        &inet_dgram_ops,
991 		.no_check =   UDP_CSUM_DEFAULT,
992 		.flags =      INET_PROTOSW_PERMANENT,
993        },
994 
995 
996        {
997 	       .type =       SOCK_RAW,
998 	       .protocol =   IPPROTO_IP,	/* wild card */
999 	       .prot =       &raw_prot,
1000 	       .ops =        &inet_sockraw_ops,
1001 	       .no_check =   UDP_CSUM_DEFAULT,
1002 	       .flags =      INET_PROTOSW_REUSE,
1003        }
1004 };
1005 
1006 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1007 
1008 void inet_register_protosw(struct inet_protosw *p)
1009 {
1010 	struct list_head *lh;
1011 	struct inet_protosw *answer;
1012 	int protocol = p->protocol;
1013 	struct list_head *last_perm;
1014 
1015 	spin_lock_bh(&inetsw_lock);
1016 
1017 	if (p->type >= SOCK_MAX)
1018 		goto out_illegal;
1019 
1020 	/* If we are trying to override a permanent protocol, bail. */
1021 	answer = NULL;
1022 	last_perm = &inetsw[p->type];
1023 	list_for_each(lh, &inetsw[p->type]) {
1024 		answer = list_entry(lh, struct inet_protosw, list);
1025 
1026 		/* Check only the non-wild match. */
1027 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1028 			if (protocol == answer->protocol)
1029 				break;
1030 			last_perm = lh;
1031 		}
1032 
1033 		answer = NULL;
1034 	}
1035 	if (answer)
1036 		goto out_permanent;
1037 
1038 	/* Add the new entry after the last permanent entry if any, so that
1039 	 * the new entry does not override a permanent entry when matched with
1040 	 * a wild-card protocol. But it is allowed to override any existing
1041 	 * non-permanent entry.  This means that when we remove this entry, the
1042 	 * system automatically returns to the old behavior.
1043 	 */
1044 	list_add_rcu(&p->list, last_perm);
1045 out:
1046 	spin_unlock_bh(&inetsw_lock);
1047 
1048 	return;
1049 
1050 out_permanent:
1051 	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1052 	       protocol);
1053 	goto out;
1054 
1055 out_illegal:
1056 	printk(KERN_ERR
1057 	       "Ignoring attempt to register invalid socket type %d.\n",
1058 	       p->type);
1059 	goto out;
1060 }
1061 EXPORT_SYMBOL(inet_register_protosw);
1062 
1063 void inet_unregister_protosw(struct inet_protosw *p)
1064 {
1065 	if (INET_PROTOSW_PERMANENT & p->flags) {
1066 		printk(KERN_ERR
1067 		       "Attempt to unregister permanent protocol %d.\n",
1068 		       p->protocol);
1069 	} else {
1070 		spin_lock_bh(&inetsw_lock);
1071 		list_del_rcu(&p->list);
1072 		spin_unlock_bh(&inetsw_lock);
1073 
1074 		synchronize_net();
1075 	}
1076 }
1077 EXPORT_SYMBOL(inet_unregister_protosw);
1078 
1079 /*
1080  *      Shall we try to damage output packets if routing dev changes?
1081  */
1082 
1083 int sysctl_ip_dynaddr __read_mostly;
1084 
1085 static int inet_sk_reselect_saddr(struct sock *sk)
1086 {
1087 	struct inet_sock *inet = inet_sk(sk);
1088 	int err;
1089 	struct rtable *rt;
1090 	__be32 old_saddr = inet->inet_saddr;
1091 	__be32 new_saddr;
1092 	__be32 daddr = inet->inet_daddr;
1093 
1094 	if (inet->opt && inet->opt->srr)
1095 		daddr = inet->opt->faddr;
1096 
1097 	/* Query new route. */
1098 	err = ip_route_connect(&rt, daddr, 0,
1099 			       RT_CONN_FLAGS(sk),
1100 			       sk->sk_bound_dev_if,
1101 			       sk->sk_protocol,
1102 			       inet->inet_sport, inet->inet_dport, sk, 0);
1103 	if (err)
1104 		return err;
1105 
1106 	sk_setup_caps(sk, &rt->dst);
1107 
1108 	new_saddr = rt->rt_src;
1109 
1110 	if (new_saddr == old_saddr)
1111 		return 0;
1112 
1113 	if (sysctl_ip_dynaddr > 1) {
1114 		printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1115 		       __func__, &old_saddr, &new_saddr);
1116 	}
1117 
1118 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1119 
1120 	/*
1121 	 * XXX The only one ugly spot where we need to
1122 	 * XXX really change the sockets identity after
1123 	 * XXX it has entered the hashes. -DaveM
1124 	 *
1125 	 * Besides that, it does not check for connection
1126 	 * uniqueness. Wait for troubles.
1127 	 */
1128 	__sk_prot_rehash(sk);
1129 	return 0;
1130 }
1131 
1132 int inet_sk_rebuild_header(struct sock *sk)
1133 {
1134 	struct inet_sock *inet = inet_sk(sk);
1135 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1136 	__be32 daddr;
1137 	int err;
1138 
1139 	/* Route is OK, nothing to do. */
1140 	if (rt)
1141 		return 0;
1142 
1143 	/* Reroute. */
1144 	daddr = inet->inet_daddr;
1145 	if (inet->opt && inet->opt->srr)
1146 		daddr = inet->opt->faddr;
1147 {
1148 	struct flowi fl = {
1149 		.oif = sk->sk_bound_dev_if,
1150 		.mark = sk->sk_mark,
1151 		.fl4_dst = daddr,
1152 		.fl4_src = inet->inet_saddr,
1153 		.fl4_tos = RT_CONN_FLAGS(sk),
1154 		.proto = sk->sk_protocol,
1155 		.flags = inet_sk_flowi_flags(sk),
1156 		.fl_ip_sport = inet->inet_sport,
1157 		.fl_ip_dport = inet->inet_dport,
1158 	};
1159 
1160 	security_sk_classify_flow(sk, &fl);
1161 	err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0);
1162 }
1163 	if (!err)
1164 		sk_setup_caps(sk, &rt->dst);
1165 	else {
1166 		/* Routing failed... */
1167 		sk->sk_route_caps = 0;
1168 		/*
1169 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1170 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1171 		 */
1172 		if (!sysctl_ip_dynaddr ||
1173 		    sk->sk_state != TCP_SYN_SENT ||
1174 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1175 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1176 			sk->sk_err_soft = -err;
1177 	}
1178 
1179 	return err;
1180 }
1181 EXPORT_SYMBOL(inet_sk_rebuild_header);
1182 
1183 static int inet_gso_send_check(struct sk_buff *skb)
1184 {
1185 	struct iphdr *iph;
1186 	const struct net_protocol *ops;
1187 	int proto;
1188 	int ihl;
1189 	int err = -EINVAL;
1190 
1191 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1192 		goto out;
1193 
1194 	iph = ip_hdr(skb);
1195 	ihl = iph->ihl * 4;
1196 	if (ihl < sizeof(*iph))
1197 		goto out;
1198 
1199 	if (unlikely(!pskb_may_pull(skb, ihl)))
1200 		goto out;
1201 
1202 	__skb_pull(skb, ihl);
1203 	skb_reset_transport_header(skb);
1204 	iph = ip_hdr(skb);
1205 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1206 	err = -EPROTONOSUPPORT;
1207 
1208 	rcu_read_lock();
1209 	ops = rcu_dereference(inet_protos[proto]);
1210 	if (likely(ops && ops->gso_send_check))
1211 		err = ops->gso_send_check(skb);
1212 	rcu_read_unlock();
1213 
1214 out:
1215 	return err;
1216 }
1217 
1218 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
1219 {
1220 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1221 	struct iphdr *iph;
1222 	const struct net_protocol *ops;
1223 	int proto;
1224 	int ihl;
1225 	int id;
1226 	unsigned int offset = 0;
1227 
1228 	if (!(features & NETIF_F_V4_CSUM))
1229 		features &= ~NETIF_F_SG;
1230 
1231 	if (unlikely(skb_shinfo(skb)->gso_type &
1232 		     ~(SKB_GSO_TCPV4 |
1233 		       SKB_GSO_UDP |
1234 		       SKB_GSO_DODGY |
1235 		       SKB_GSO_TCP_ECN |
1236 		       0)))
1237 		goto out;
1238 
1239 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1240 		goto out;
1241 
1242 	iph = ip_hdr(skb);
1243 	ihl = iph->ihl * 4;
1244 	if (ihl < sizeof(*iph))
1245 		goto out;
1246 
1247 	if (unlikely(!pskb_may_pull(skb, ihl)))
1248 		goto out;
1249 
1250 	__skb_pull(skb, ihl);
1251 	skb_reset_transport_header(skb);
1252 	iph = ip_hdr(skb);
1253 	id = ntohs(iph->id);
1254 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1255 	segs = ERR_PTR(-EPROTONOSUPPORT);
1256 
1257 	rcu_read_lock();
1258 	ops = rcu_dereference(inet_protos[proto]);
1259 	if (likely(ops && ops->gso_segment))
1260 		segs = ops->gso_segment(skb, features);
1261 	rcu_read_unlock();
1262 
1263 	if (!segs || IS_ERR(segs))
1264 		goto out;
1265 
1266 	skb = segs;
1267 	do {
1268 		iph = ip_hdr(skb);
1269 		if (proto == IPPROTO_UDP) {
1270 			iph->id = htons(id);
1271 			iph->frag_off = htons(offset >> 3);
1272 			if (skb->next != NULL)
1273 				iph->frag_off |= htons(IP_MF);
1274 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1275 		} else
1276 			iph->id = htons(id++);
1277 		iph->tot_len = htons(skb->len - skb->mac_len);
1278 		iph->check = 0;
1279 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1280 	} while ((skb = skb->next));
1281 
1282 out:
1283 	return segs;
1284 }
1285 
1286 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1287 					 struct sk_buff *skb)
1288 {
1289 	const struct net_protocol *ops;
1290 	struct sk_buff **pp = NULL;
1291 	struct sk_buff *p;
1292 	struct iphdr *iph;
1293 	unsigned int hlen;
1294 	unsigned int off;
1295 	unsigned int id;
1296 	int flush = 1;
1297 	int proto;
1298 
1299 	off = skb_gro_offset(skb);
1300 	hlen = off + sizeof(*iph);
1301 	iph = skb_gro_header_fast(skb, off);
1302 	if (skb_gro_header_hard(skb, hlen)) {
1303 		iph = skb_gro_header_slow(skb, hlen, off);
1304 		if (unlikely(!iph))
1305 			goto out;
1306 	}
1307 
1308 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1309 
1310 	rcu_read_lock();
1311 	ops = rcu_dereference(inet_protos[proto]);
1312 	if (!ops || !ops->gro_receive)
1313 		goto out_unlock;
1314 
1315 	if (*(u8 *)iph != 0x45)
1316 		goto out_unlock;
1317 
1318 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1319 		goto out_unlock;
1320 
1321 	id = ntohl(*(__be32 *)&iph->id);
1322 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1323 	id >>= 16;
1324 
1325 	for (p = *head; p; p = p->next) {
1326 		struct iphdr *iph2;
1327 
1328 		if (!NAPI_GRO_CB(p)->same_flow)
1329 			continue;
1330 
1331 		iph2 = ip_hdr(p);
1332 
1333 		if ((iph->protocol ^ iph2->protocol) |
1334 		    (iph->tos ^ iph2->tos) |
1335 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1336 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1337 			NAPI_GRO_CB(p)->same_flow = 0;
1338 			continue;
1339 		}
1340 
1341 		/* All fields must match except length and checksum. */
1342 		NAPI_GRO_CB(p)->flush |=
1343 			(iph->ttl ^ iph2->ttl) |
1344 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1345 
1346 		NAPI_GRO_CB(p)->flush |= flush;
1347 	}
1348 
1349 	NAPI_GRO_CB(skb)->flush |= flush;
1350 	skb_gro_pull(skb, sizeof(*iph));
1351 	skb_set_transport_header(skb, skb_gro_offset(skb));
1352 
1353 	pp = ops->gro_receive(head, skb);
1354 
1355 out_unlock:
1356 	rcu_read_unlock();
1357 
1358 out:
1359 	NAPI_GRO_CB(skb)->flush |= flush;
1360 
1361 	return pp;
1362 }
1363 
1364 static int inet_gro_complete(struct sk_buff *skb)
1365 {
1366 	const struct net_protocol *ops;
1367 	struct iphdr *iph = ip_hdr(skb);
1368 	int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1369 	int err = -ENOSYS;
1370 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1371 
1372 	csum_replace2(&iph->check, iph->tot_len, newlen);
1373 	iph->tot_len = newlen;
1374 
1375 	rcu_read_lock();
1376 	ops = rcu_dereference(inet_protos[proto]);
1377 	if (WARN_ON(!ops || !ops->gro_complete))
1378 		goto out_unlock;
1379 
1380 	err = ops->gro_complete(skb);
1381 
1382 out_unlock:
1383 	rcu_read_unlock();
1384 
1385 	return err;
1386 }
1387 
1388 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1389 			 unsigned short type, unsigned char protocol,
1390 			 struct net *net)
1391 {
1392 	struct socket *sock;
1393 	int rc = sock_create_kern(family, type, protocol, &sock);
1394 
1395 	if (rc == 0) {
1396 		*sk = sock->sk;
1397 		(*sk)->sk_allocation = GFP_ATOMIC;
1398 		/*
1399 		 * Unhash it so that IP input processing does not even see it,
1400 		 * we do not wish this socket to see incoming packets.
1401 		 */
1402 		(*sk)->sk_prot->unhash(*sk);
1403 
1404 		sk_change_net(*sk, net);
1405 	}
1406 	return rc;
1407 }
1408 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1409 
1410 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1411 {
1412 	unsigned long res = 0;
1413 	int i;
1414 
1415 	for_each_possible_cpu(i) {
1416 		res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1417 		res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1418 	}
1419 	return res;
1420 }
1421 EXPORT_SYMBOL_GPL(snmp_fold_field);
1422 
1423 #if BITS_PER_LONG==32
1424 
1425 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1426 {
1427 	u64 res = 0;
1428 	int cpu;
1429 
1430 	for_each_possible_cpu(cpu) {
1431 		void *bhptr, *userptr;
1432 		struct u64_stats_sync *syncp;
1433 		u64 v_bh, v_user;
1434 		unsigned int start;
1435 
1436 		/* first mib used by softirq context, we must use _bh() accessors */
1437 		bhptr = per_cpu_ptr(SNMP_STAT_BHPTR(mib), cpu);
1438 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1439 		do {
1440 			start = u64_stats_fetch_begin_bh(syncp);
1441 			v_bh = *(((u64 *) bhptr) + offt);
1442 		} while (u64_stats_fetch_retry_bh(syncp, start));
1443 
1444 		/* second mib used in USER context */
1445 		userptr = per_cpu_ptr(SNMP_STAT_USRPTR(mib), cpu);
1446 		syncp = (struct u64_stats_sync *)(userptr + syncp_offset);
1447 		do {
1448 			start = u64_stats_fetch_begin(syncp);
1449 			v_user = *(((u64 *) userptr) + offt);
1450 		} while (u64_stats_fetch_retry(syncp, start));
1451 
1452 		res += v_bh + v_user;
1453 	}
1454 	return res;
1455 }
1456 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1457 #endif
1458 
1459 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1460 {
1461 	BUG_ON(ptr == NULL);
1462 	ptr[0] = __alloc_percpu(mibsize, align);
1463 	if (!ptr[0])
1464 		goto err0;
1465 	ptr[1] = __alloc_percpu(mibsize, align);
1466 	if (!ptr[1])
1467 		goto err1;
1468 	return 0;
1469 err1:
1470 	free_percpu(ptr[0]);
1471 	ptr[0] = NULL;
1472 err0:
1473 	return -ENOMEM;
1474 }
1475 EXPORT_SYMBOL_GPL(snmp_mib_init);
1476 
1477 void snmp_mib_free(void __percpu *ptr[2])
1478 {
1479 	BUG_ON(ptr == NULL);
1480 	free_percpu(ptr[0]);
1481 	free_percpu(ptr[1]);
1482 	ptr[0] = ptr[1] = NULL;
1483 }
1484 EXPORT_SYMBOL_GPL(snmp_mib_free);
1485 
1486 #ifdef CONFIG_IP_MULTICAST
1487 static const struct net_protocol igmp_protocol = {
1488 	.handler =	igmp_rcv,
1489 	.netns_ok =	1,
1490 };
1491 #endif
1492 
1493 static const struct net_protocol tcp_protocol = {
1494 	.handler =	tcp_v4_rcv,
1495 	.err_handler =	tcp_v4_err,
1496 	.gso_send_check = tcp_v4_gso_send_check,
1497 	.gso_segment =	tcp_tso_segment,
1498 	.gro_receive =	tcp4_gro_receive,
1499 	.gro_complete =	tcp4_gro_complete,
1500 	.no_policy =	1,
1501 	.netns_ok =	1,
1502 };
1503 
1504 static const struct net_protocol udp_protocol = {
1505 	.handler =	udp_rcv,
1506 	.err_handler =	udp_err,
1507 	.gso_send_check = udp4_ufo_send_check,
1508 	.gso_segment = udp4_ufo_fragment,
1509 	.no_policy =	1,
1510 	.netns_ok =	1,
1511 };
1512 
1513 static const struct net_protocol icmp_protocol = {
1514 	.handler =	icmp_rcv,
1515 	.no_policy =	1,
1516 	.netns_ok =	1,
1517 };
1518 
1519 static __net_init int ipv4_mib_init_net(struct net *net)
1520 {
1521 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1522 			  sizeof(struct tcp_mib),
1523 			  __alignof__(struct tcp_mib)) < 0)
1524 		goto err_tcp_mib;
1525 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1526 			  sizeof(struct ipstats_mib),
1527 			  __alignof__(struct ipstats_mib)) < 0)
1528 		goto err_ip_mib;
1529 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1530 			  sizeof(struct linux_mib),
1531 			  __alignof__(struct linux_mib)) < 0)
1532 		goto err_net_mib;
1533 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1534 			  sizeof(struct udp_mib),
1535 			  __alignof__(struct udp_mib)) < 0)
1536 		goto err_udp_mib;
1537 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1538 			  sizeof(struct udp_mib),
1539 			  __alignof__(struct udp_mib)) < 0)
1540 		goto err_udplite_mib;
1541 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1542 			  sizeof(struct icmp_mib),
1543 			  __alignof__(struct icmp_mib)) < 0)
1544 		goto err_icmp_mib;
1545 	if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
1546 			  sizeof(struct icmpmsg_mib),
1547 			  __alignof__(struct icmpmsg_mib)) < 0)
1548 		goto err_icmpmsg_mib;
1549 
1550 	tcp_mib_init(net);
1551 	return 0;
1552 
1553 err_icmpmsg_mib:
1554 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1555 err_icmp_mib:
1556 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1557 err_udplite_mib:
1558 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1559 err_udp_mib:
1560 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1561 err_net_mib:
1562 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1563 err_ip_mib:
1564 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1565 err_tcp_mib:
1566 	return -ENOMEM;
1567 }
1568 
1569 static __net_exit void ipv4_mib_exit_net(struct net *net)
1570 {
1571 	snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
1572 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1573 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1574 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1575 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1576 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1577 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1578 }
1579 
1580 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1581 	.init = ipv4_mib_init_net,
1582 	.exit = ipv4_mib_exit_net,
1583 };
1584 
1585 static int __init init_ipv4_mibs(void)
1586 {
1587 	return register_pernet_subsys(&ipv4_mib_ops);
1588 }
1589 
1590 static int ipv4_proc_init(void);
1591 
1592 /*
1593  *	IP protocol layer initialiser
1594  */
1595 
1596 static struct packet_type ip_packet_type __read_mostly = {
1597 	.type = cpu_to_be16(ETH_P_IP),
1598 	.func = ip_rcv,
1599 	.gso_send_check = inet_gso_send_check,
1600 	.gso_segment = inet_gso_segment,
1601 	.gro_receive = inet_gro_receive,
1602 	.gro_complete = inet_gro_complete,
1603 };
1604 
1605 static int __init inet_init(void)
1606 {
1607 	struct sk_buff *dummy_skb;
1608 	struct inet_protosw *q;
1609 	struct list_head *r;
1610 	int rc = -EINVAL;
1611 
1612 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1613 
1614 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1615 	if (!sysctl_local_reserved_ports)
1616 		goto out;
1617 
1618 	rc = proto_register(&tcp_prot, 1);
1619 	if (rc)
1620 		goto out_free_reserved_ports;
1621 
1622 	rc = proto_register(&udp_prot, 1);
1623 	if (rc)
1624 		goto out_unregister_tcp_proto;
1625 
1626 	rc = proto_register(&raw_prot, 1);
1627 	if (rc)
1628 		goto out_unregister_udp_proto;
1629 
1630 	/*
1631 	 *	Tell SOCKET that we are alive...
1632 	 */
1633 
1634 	(void)sock_register(&inet_family_ops);
1635 
1636 #ifdef CONFIG_SYSCTL
1637 	ip_static_sysctl_init();
1638 #endif
1639 
1640 	/*
1641 	 *	Add all the base protocols.
1642 	 */
1643 
1644 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1645 		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1646 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1647 		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1648 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1649 		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1650 #ifdef CONFIG_IP_MULTICAST
1651 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1652 		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1653 #endif
1654 
1655 	/* Register the socket-side information for inet_create. */
1656 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1657 		INIT_LIST_HEAD(r);
1658 
1659 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1660 		inet_register_protosw(q);
1661 
1662 	/*
1663 	 *	Set the ARP module up
1664 	 */
1665 
1666 	arp_init();
1667 
1668 	/*
1669 	 *	Set the IP module up
1670 	 */
1671 
1672 	ip_init();
1673 
1674 	tcp_v4_init();
1675 
1676 	/* Setup TCP slab cache for open requests. */
1677 	tcp_init();
1678 
1679 	/* Setup UDP memory threshold */
1680 	udp_init();
1681 
1682 	/* Add UDP-Lite (RFC 3828) */
1683 	udplite4_register();
1684 
1685 	/*
1686 	 *	Set the ICMP layer up
1687 	 */
1688 
1689 	if (icmp_init() < 0)
1690 		panic("Failed to create the ICMP control socket.\n");
1691 
1692 	/*
1693 	 *	Initialise the multicast router
1694 	 */
1695 #if defined(CONFIG_IP_MROUTE)
1696 	if (ip_mr_init())
1697 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1698 #endif
1699 	/*
1700 	 *	Initialise per-cpu ipv4 mibs
1701 	 */
1702 
1703 	if (init_ipv4_mibs())
1704 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1705 
1706 	ipv4_proc_init();
1707 
1708 	ipfrag_init();
1709 
1710 	dev_add_pack(&ip_packet_type);
1711 
1712 	rc = 0;
1713 out:
1714 	return rc;
1715 out_unregister_udp_proto:
1716 	proto_unregister(&udp_prot);
1717 out_unregister_tcp_proto:
1718 	proto_unregister(&tcp_prot);
1719 out_free_reserved_ports:
1720 	kfree(sysctl_local_reserved_ports);
1721 	goto out;
1722 }
1723 
1724 fs_initcall(inet_init);
1725 
1726 /* ------------------------------------------------------------------------ */
1727 
1728 #ifdef CONFIG_PROC_FS
1729 static int __init ipv4_proc_init(void)
1730 {
1731 	int rc = 0;
1732 
1733 	if (raw_proc_init())
1734 		goto out_raw;
1735 	if (tcp4_proc_init())
1736 		goto out_tcp;
1737 	if (udp4_proc_init())
1738 		goto out_udp;
1739 	if (ip_misc_proc_init())
1740 		goto out_misc;
1741 out:
1742 	return rc;
1743 out_misc:
1744 	udp4_proc_exit();
1745 out_udp:
1746 	tcp4_proc_exit();
1747 out_tcp:
1748 	raw_proc_exit();
1749 out_raw:
1750 	rc = -ENOMEM;
1751 	goto out;
1752 }
1753 
1754 #else /* CONFIG_PROC_FS */
1755 static int __init ipv4_proc_init(void)
1756 {
1757 	return 0;
1758 }
1759 #endif /* CONFIG_PROC_FS */
1760 
1761 MODULE_ALIAS_NETPROTO(PF_INET);
1762 
1763