xref: /openbmc/linux/net/ipv4/af_inet.c (revision 81d67439)
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 <net/ping.h>
109 #include <linux/skbuff.h>
110 #include <net/sock.h>
111 #include <net/raw.h>
112 #include <net/icmp.h>
113 #include <net/ipip.h>
114 #include <net/inet_common.h>
115 #include <net/xfrm.h>
116 #include <net/net_namespace.h>
117 #ifdef CONFIG_IP_MROUTE
118 #include <linux/mroute.h>
119 #endif
120 
121 
122 /* The inetsw table contains everything that inet_create needs to
123  * build a new socket.
124  */
125 static struct list_head inetsw[SOCK_MAX];
126 static DEFINE_SPINLOCK(inetsw_lock);
127 
128 struct ipv4_config ipv4_config;
129 EXPORT_SYMBOL(ipv4_config);
130 
131 /* New destruction routine */
132 
133 void inet_sock_destruct(struct sock *sk)
134 {
135 	struct inet_sock *inet = inet_sk(sk);
136 
137 	__skb_queue_purge(&sk->sk_receive_queue);
138 	__skb_queue_purge(&sk->sk_error_queue);
139 
140 	sk_mem_reclaim(sk);
141 
142 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
143 		pr_err("Attempt to release TCP socket in state %d %p\n",
144 		       sk->sk_state, sk);
145 		return;
146 	}
147 	if (!sock_flag(sk, SOCK_DEAD)) {
148 		pr_err("Attempt to release alive inet socket %p\n", sk);
149 		return;
150 	}
151 
152 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
153 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
154 	WARN_ON(sk->sk_wmem_queued);
155 	WARN_ON(sk->sk_forward_alloc);
156 
157 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
158 	dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
159 	sk_refcnt_debug_dec(sk);
160 }
161 EXPORT_SYMBOL(inet_sock_destruct);
162 
163 /*
164  *	The routines beyond this point handle the behaviour of an AF_INET
165  *	socket object. Mostly it punts to the subprotocols of IP to do
166  *	the work.
167  */
168 
169 /*
170  *	Automatically bind an unbound socket.
171  */
172 
173 static int inet_autobind(struct sock *sk)
174 {
175 	struct inet_sock *inet;
176 	/* We may need to bind the socket. */
177 	lock_sock(sk);
178 	inet = inet_sk(sk);
179 	if (!inet->inet_num) {
180 		if (sk->sk_prot->get_port(sk, 0)) {
181 			release_sock(sk);
182 			return -EAGAIN;
183 		}
184 		inet->inet_sport = htons(inet->inet_num);
185 	}
186 	release_sock(sk);
187 	return 0;
188 }
189 
190 /*
191  *	Move a socket into listening state.
192  */
193 int inet_listen(struct socket *sock, int backlog)
194 {
195 	struct sock *sk = sock->sk;
196 	unsigned char old_state;
197 	int err;
198 
199 	lock_sock(sk);
200 
201 	err = -EINVAL;
202 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
203 		goto out;
204 
205 	old_state = sk->sk_state;
206 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
207 		goto out;
208 
209 	/* Really, if the socket is already in listen state
210 	 * we can only allow the backlog to be adjusted.
211 	 */
212 	if (old_state != TCP_LISTEN) {
213 		err = inet_csk_listen_start(sk, backlog);
214 		if (err)
215 			goto out;
216 	}
217 	sk->sk_max_ack_backlog = backlog;
218 	err = 0;
219 
220 out:
221 	release_sock(sk);
222 	return err;
223 }
224 EXPORT_SYMBOL(inet_listen);
225 
226 u32 inet_ehash_secret __read_mostly;
227 EXPORT_SYMBOL(inet_ehash_secret);
228 
229 /*
230  * inet_ehash_secret must be set exactly once
231  */
232 void build_ehash_secret(void)
233 {
234 	u32 rnd;
235 
236 	do {
237 		get_random_bytes(&rnd, sizeof(rnd));
238 	} while (rnd == 0);
239 
240 	cmpxchg(&inet_ehash_secret, 0, rnd);
241 }
242 EXPORT_SYMBOL(build_ehash_secret);
243 
244 static inline int inet_netns_ok(struct net *net, int protocol)
245 {
246 	int hash;
247 	const struct net_protocol *ipprot;
248 
249 	if (net_eq(net, &init_net))
250 		return 1;
251 
252 	hash = protocol & (MAX_INET_PROTOS - 1);
253 	ipprot = rcu_dereference(inet_protos[hash]);
254 
255 	if (ipprot == NULL)
256 		/* raw IP is OK */
257 		return 1;
258 	return ipprot->netns_ok;
259 }
260 
261 /*
262  *	Create an inet socket.
263  */
264 
265 static int inet_create(struct net *net, struct socket *sock, int protocol,
266 		       int kern)
267 {
268 	struct sock *sk;
269 	struct inet_protosw *answer;
270 	struct inet_sock *inet;
271 	struct proto *answer_prot;
272 	unsigned char answer_flags;
273 	char answer_no_check;
274 	int try_loading_module = 0;
275 	int err;
276 
277 	if (unlikely(!inet_ehash_secret))
278 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
279 			build_ehash_secret();
280 
281 	sock->state = SS_UNCONNECTED;
282 
283 	/* Look for the requested type/protocol pair. */
284 lookup_protocol:
285 	err = -ESOCKTNOSUPPORT;
286 	rcu_read_lock();
287 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
288 
289 		err = 0;
290 		/* Check the non-wild match. */
291 		if (protocol == answer->protocol) {
292 			if (protocol != IPPROTO_IP)
293 				break;
294 		} else {
295 			/* Check for the two wild cases. */
296 			if (IPPROTO_IP == protocol) {
297 				protocol = answer->protocol;
298 				break;
299 			}
300 			if (IPPROTO_IP == answer->protocol)
301 				break;
302 		}
303 		err = -EPROTONOSUPPORT;
304 	}
305 
306 	if (unlikely(err)) {
307 		if (try_loading_module < 2) {
308 			rcu_read_unlock();
309 			/*
310 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
311 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
312 			 */
313 			if (++try_loading_module == 1)
314 				request_module("net-pf-%d-proto-%d-type-%d",
315 					       PF_INET, protocol, sock->type);
316 			/*
317 			 * Fall back to generic, e.g. net-pf-2-proto-132
318 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
319 			 */
320 			else
321 				request_module("net-pf-%d-proto-%d",
322 					       PF_INET, protocol);
323 			goto lookup_protocol;
324 		} else
325 			goto out_rcu_unlock;
326 	}
327 
328 	err = -EPERM;
329 	if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
330 		goto out_rcu_unlock;
331 
332 	err = -EAFNOSUPPORT;
333 	if (!inet_netns_ok(net, protocol))
334 		goto out_rcu_unlock;
335 
336 	sock->ops = answer->ops;
337 	answer_prot = answer->prot;
338 	answer_no_check = answer->no_check;
339 	answer_flags = answer->flags;
340 	rcu_read_unlock();
341 
342 	WARN_ON(answer_prot->slab == NULL);
343 
344 	err = -ENOBUFS;
345 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
346 	if (sk == NULL)
347 		goto out;
348 
349 	err = 0;
350 	sk->sk_no_check = answer_no_check;
351 	if (INET_PROTOSW_REUSE & answer_flags)
352 		sk->sk_reuse = 1;
353 
354 	inet = inet_sk(sk);
355 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
356 
357 	inet->nodefrag = 0;
358 
359 	if (SOCK_RAW == sock->type) {
360 		inet->inet_num = protocol;
361 		if (IPPROTO_RAW == protocol)
362 			inet->hdrincl = 1;
363 	}
364 
365 	if (ipv4_config.no_pmtu_disc)
366 		inet->pmtudisc = IP_PMTUDISC_DONT;
367 	else
368 		inet->pmtudisc = IP_PMTUDISC_WANT;
369 
370 	inet->inet_id = 0;
371 
372 	sock_init_data(sock, sk);
373 
374 	sk->sk_destruct	   = inet_sock_destruct;
375 	sk->sk_protocol	   = protocol;
376 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
377 
378 	inet->uc_ttl	= -1;
379 	inet->mc_loop	= 1;
380 	inet->mc_ttl	= 1;
381 	inet->mc_all	= 1;
382 	inet->mc_index	= 0;
383 	inet->mc_list	= NULL;
384 
385 	sk_refcnt_debug_inc(sk);
386 
387 	if (inet->inet_num) {
388 		/* It assumes that any protocol which allows
389 		 * the user to assign a number at socket
390 		 * creation time automatically
391 		 * shares.
392 		 */
393 		inet->inet_sport = htons(inet->inet_num);
394 		/* Add to protocol hash chains. */
395 		sk->sk_prot->hash(sk);
396 	}
397 
398 	if (sk->sk_prot->init) {
399 		err = sk->sk_prot->init(sk);
400 		if (err)
401 			sk_common_release(sk);
402 	}
403 out:
404 	return err;
405 out_rcu_unlock:
406 	rcu_read_unlock();
407 	goto out;
408 }
409 
410 
411 /*
412  *	The peer socket should always be NULL (or else). When we call this
413  *	function we are destroying the object and from then on nobody
414  *	should refer to it.
415  */
416 int inet_release(struct socket *sock)
417 {
418 	struct sock *sk = sock->sk;
419 
420 	if (sk) {
421 		long timeout;
422 
423 		sock_rps_reset_flow(sk);
424 
425 		/* Applications forget to leave groups before exiting */
426 		ip_mc_drop_socket(sk);
427 
428 		/* If linger is set, we don't return until the close
429 		 * is complete.  Otherwise we return immediately. The
430 		 * actually closing is done the same either way.
431 		 *
432 		 * If the close is due to the process exiting, we never
433 		 * linger..
434 		 */
435 		timeout = 0;
436 		if (sock_flag(sk, SOCK_LINGER) &&
437 		    !(current->flags & PF_EXITING))
438 			timeout = sk->sk_lingertime;
439 		sock->sk = NULL;
440 		sk->sk_prot->close(sk, timeout);
441 	}
442 	return 0;
443 }
444 EXPORT_SYMBOL(inet_release);
445 
446 /* It is off by default, see below. */
447 int sysctl_ip_nonlocal_bind __read_mostly;
448 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
449 
450 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
451 {
452 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
453 	struct sock *sk = sock->sk;
454 	struct inet_sock *inet = inet_sk(sk);
455 	unsigned short snum;
456 	int chk_addr_ret;
457 	int err;
458 
459 	/* If the socket has its own bind function then use it. (RAW) */
460 	if (sk->sk_prot->bind) {
461 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
462 		goto out;
463 	}
464 	err = -EINVAL;
465 	if (addr_len < sizeof(struct sockaddr_in))
466 		goto out;
467 
468 	if (addr->sin_family != AF_INET) {
469 		err = -EAFNOSUPPORT;
470 		goto out;
471 	}
472 
473 	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
474 
475 	/* Not specified by any standard per-se, however it breaks too
476 	 * many applications when removed.  It is unfortunate since
477 	 * allowing applications to make a non-local bind solves
478 	 * several problems with systems using dynamic addressing.
479 	 * (ie. your servers still start up even if your ISDN link
480 	 *  is temporarily down)
481 	 */
482 	err = -EADDRNOTAVAIL;
483 	if (!sysctl_ip_nonlocal_bind &&
484 	    !(inet->freebind || inet->transparent) &&
485 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
486 	    chk_addr_ret != RTN_LOCAL &&
487 	    chk_addr_ret != RTN_MULTICAST &&
488 	    chk_addr_ret != RTN_BROADCAST)
489 		goto out;
490 
491 	snum = ntohs(addr->sin_port);
492 	err = -EACCES;
493 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
494 		goto out;
495 
496 	/*      We keep a pair of addresses. rcv_saddr is the one
497 	 *      used by hash lookups, and saddr is used for transmit.
498 	 *
499 	 *      In the BSD API these are the same except where it
500 	 *      would be illegal to use them (multicast/broadcast) in
501 	 *      which case the sending device address is used.
502 	 */
503 	lock_sock(sk);
504 
505 	/* Check these errors (active socket, double bind). */
506 	err = -EINVAL;
507 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
508 		goto out_release_sock;
509 
510 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
511 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
512 		inet->inet_saddr = 0;  /* Use device */
513 
514 	/* Make sure we are allowed to bind here. */
515 	if (sk->sk_prot->get_port(sk, snum)) {
516 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
517 		err = -EADDRINUSE;
518 		goto out_release_sock;
519 	}
520 
521 	if (inet->inet_rcv_saddr)
522 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
523 	if (snum)
524 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
525 	inet->inet_sport = htons(inet->inet_num);
526 	inet->inet_daddr = 0;
527 	inet->inet_dport = 0;
528 	sk_dst_reset(sk);
529 	err = 0;
530 out_release_sock:
531 	release_sock(sk);
532 out:
533 	return err;
534 }
535 EXPORT_SYMBOL(inet_bind);
536 
537 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
538 		       int addr_len, int flags)
539 {
540 	struct sock *sk = sock->sk;
541 
542 	if (addr_len < sizeof(uaddr->sa_family))
543 		return -EINVAL;
544 	if (uaddr->sa_family == AF_UNSPEC)
545 		return sk->sk_prot->disconnect(sk, flags);
546 
547 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
548 		return -EAGAIN;
549 	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
550 }
551 EXPORT_SYMBOL(inet_dgram_connect);
552 
553 static long inet_wait_for_connect(struct sock *sk, long timeo)
554 {
555 	DEFINE_WAIT(wait);
556 
557 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
558 
559 	/* Basic assumption: if someone sets sk->sk_err, he _must_
560 	 * change state of the socket from TCP_SYN_*.
561 	 * Connect() does not allow to get error notifications
562 	 * without closing the socket.
563 	 */
564 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
565 		release_sock(sk);
566 		timeo = schedule_timeout(timeo);
567 		lock_sock(sk);
568 		if (signal_pending(current) || !timeo)
569 			break;
570 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
571 	}
572 	finish_wait(sk_sleep(sk), &wait);
573 	return timeo;
574 }
575 
576 /*
577  *	Connect to a remote host. There is regrettably still a little
578  *	TCP 'magic' in here.
579  */
580 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
581 			int addr_len, int flags)
582 {
583 	struct sock *sk = sock->sk;
584 	int err;
585 	long timeo;
586 
587 	if (addr_len < sizeof(uaddr->sa_family))
588 		return -EINVAL;
589 
590 	lock_sock(sk);
591 
592 	if (uaddr->sa_family == AF_UNSPEC) {
593 		err = sk->sk_prot->disconnect(sk, flags);
594 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
595 		goto out;
596 	}
597 
598 	switch (sock->state) {
599 	default:
600 		err = -EINVAL;
601 		goto out;
602 	case SS_CONNECTED:
603 		err = -EISCONN;
604 		goto out;
605 	case SS_CONNECTING:
606 		err = -EALREADY;
607 		/* Fall out of switch with err, set for this state */
608 		break;
609 	case SS_UNCONNECTED:
610 		err = -EISCONN;
611 		if (sk->sk_state != TCP_CLOSE)
612 			goto out;
613 
614 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
615 		if (err < 0)
616 			goto out;
617 
618 		sock->state = SS_CONNECTING;
619 
620 		/* Just entered SS_CONNECTING state; the only
621 		 * difference is that return value in non-blocking
622 		 * case is EINPROGRESS, rather than EALREADY.
623 		 */
624 		err = -EINPROGRESS;
625 		break;
626 	}
627 
628 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
629 
630 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
631 		/* Error code is set above */
632 		if (!timeo || !inet_wait_for_connect(sk, timeo))
633 			goto out;
634 
635 		err = sock_intr_errno(timeo);
636 		if (signal_pending(current))
637 			goto out;
638 	}
639 
640 	/* Connection was closed by RST, timeout, ICMP error
641 	 * or another process disconnected us.
642 	 */
643 	if (sk->sk_state == TCP_CLOSE)
644 		goto sock_error;
645 
646 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
647 	 * and error was received after socket entered established state.
648 	 * Hence, it is handled normally after connect() return successfully.
649 	 */
650 
651 	sock->state = SS_CONNECTED;
652 	err = 0;
653 out:
654 	release_sock(sk);
655 	return err;
656 
657 sock_error:
658 	err = sock_error(sk) ? : -ECONNABORTED;
659 	sock->state = SS_UNCONNECTED;
660 	if (sk->sk_prot->disconnect(sk, flags))
661 		sock->state = SS_DISCONNECTING;
662 	goto out;
663 }
664 EXPORT_SYMBOL(inet_stream_connect);
665 
666 /*
667  *	Accept a pending connection. The TCP layer now gives BSD semantics.
668  */
669 
670 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
671 {
672 	struct sock *sk1 = sock->sk;
673 	int err = -EINVAL;
674 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
675 
676 	if (!sk2)
677 		goto do_err;
678 
679 	lock_sock(sk2);
680 
681 	sock_rps_record_flow(sk2);
682 	WARN_ON(!((1 << sk2->sk_state) &
683 		  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
684 
685 	sock_graft(sk2, newsock);
686 
687 	newsock->state = SS_CONNECTED;
688 	err = 0;
689 	release_sock(sk2);
690 do_err:
691 	return err;
692 }
693 EXPORT_SYMBOL(inet_accept);
694 
695 
696 /*
697  *	This does both peername and sockname.
698  */
699 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
700 			int *uaddr_len, int peer)
701 {
702 	struct sock *sk		= sock->sk;
703 	struct inet_sock *inet	= inet_sk(sk);
704 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
705 
706 	sin->sin_family = AF_INET;
707 	if (peer) {
708 		if (!inet->inet_dport ||
709 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
710 		     peer == 1))
711 			return -ENOTCONN;
712 		sin->sin_port = inet->inet_dport;
713 		sin->sin_addr.s_addr = inet->inet_daddr;
714 	} else {
715 		__be32 addr = inet->inet_rcv_saddr;
716 		if (!addr)
717 			addr = inet->inet_saddr;
718 		sin->sin_port = inet->inet_sport;
719 		sin->sin_addr.s_addr = addr;
720 	}
721 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
722 	*uaddr_len = sizeof(*sin);
723 	return 0;
724 }
725 EXPORT_SYMBOL(inet_getname);
726 
727 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
728 		 size_t size)
729 {
730 	struct sock *sk = sock->sk;
731 
732 	sock_rps_record_flow(sk);
733 
734 	/* We may need to bind the socket. */
735 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
736 	    inet_autobind(sk))
737 		return -EAGAIN;
738 
739 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
740 }
741 EXPORT_SYMBOL(inet_sendmsg);
742 
743 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
744 		      size_t size, int flags)
745 {
746 	struct sock *sk = sock->sk;
747 
748 	sock_rps_record_flow(sk);
749 
750 	/* We may need to bind the socket. */
751 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
752 	    inet_autobind(sk))
753 		return -EAGAIN;
754 
755 	if (sk->sk_prot->sendpage)
756 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
757 	return sock_no_sendpage(sock, page, offset, size, flags);
758 }
759 EXPORT_SYMBOL(inet_sendpage);
760 
761 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
762 		 size_t size, int flags)
763 {
764 	struct sock *sk = sock->sk;
765 	int addr_len = 0;
766 	int err;
767 
768 	sock_rps_record_flow(sk);
769 
770 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
771 				   flags & ~MSG_DONTWAIT, &addr_len);
772 	if (err >= 0)
773 		msg->msg_namelen = addr_len;
774 	return err;
775 }
776 EXPORT_SYMBOL(inet_recvmsg);
777 
778 int inet_shutdown(struct socket *sock, int how)
779 {
780 	struct sock *sk = sock->sk;
781 	int err = 0;
782 
783 	/* This should really check to make sure
784 	 * the socket is a TCP socket. (WHY AC...)
785 	 */
786 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
787 		       1->2 bit 2 snds.
788 		       2->3 */
789 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
790 		return -EINVAL;
791 
792 	lock_sock(sk);
793 	if (sock->state == SS_CONNECTING) {
794 		if ((1 << sk->sk_state) &
795 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
796 			sock->state = SS_DISCONNECTING;
797 		else
798 			sock->state = SS_CONNECTED;
799 	}
800 
801 	switch (sk->sk_state) {
802 	case TCP_CLOSE:
803 		err = -ENOTCONN;
804 		/* Hack to wake up other listeners, who can poll for
805 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
806 	default:
807 		sk->sk_shutdown |= how;
808 		if (sk->sk_prot->shutdown)
809 			sk->sk_prot->shutdown(sk, how);
810 		break;
811 
812 	/* Remaining two branches are temporary solution for missing
813 	 * close() in multithreaded environment. It is _not_ a good idea,
814 	 * but we have no choice until close() is repaired at VFS level.
815 	 */
816 	case TCP_LISTEN:
817 		if (!(how & RCV_SHUTDOWN))
818 			break;
819 		/* Fall through */
820 	case TCP_SYN_SENT:
821 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
822 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
823 		break;
824 	}
825 
826 	/* Wake up anyone sleeping in poll. */
827 	sk->sk_state_change(sk);
828 	release_sock(sk);
829 	return err;
830 }
831 EXPORT_SYMBOL(inet_shutdown);
832 
833 /*
834  *	ioctl() calls you can issue on an INET socket. Most of these are
835  *	device configuration and stuff and very rarely used. Some ioctls
836  *	pass on to the socket itself.
837  *
838  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
839  *	loads the devconfigure module does its configuring and unloads it.
840  *	There's a good 20K of config code hanging around the kernel.
841  */
842 
843 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
844 {
845 	struct sock *sk = sock->sk;
846 	int err = 0;
847 	struct net *net = sock_net(sk);
848 
849 	switch (cmd) {
850 	case SIOCGSTAMP:
851 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
852 		break;
853 	case SIOCGSTAMPNS:
854 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
855 		break;
856 	case SIOCADDRT:
857 	case SIOCDELRT:
858 	case SIOCRTMSG:
859 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
860 		break;
861 	case SIOCDARP:
862 	case SIOCGARP:
863 	case SIOCSARP:
864 		err = arp_ioctl(net, cmd, (void __user *)arg);
865 		break;
866 	case SIOCGIFADDR:
867 	case SIOCSIFADDR:
868 	case SIOCGIFBRDADDR:
869 	case SIOCSIFBRDADDR:
870 	case SIOCGIFNETMASK:
871 	case SIOCSIFNETMASK:
872 	case SIOCGIFDSTADDR:
873 	case SIOCSIFDSTADDR:
874 	case SIOCSIFPFLAGS:
875 	case SIOCGIFPFLAGS:
876 	case SIOCSIFFLAGS:
877 		err = devinet_ioctl(net, cmd, (void __user *)arg);
878 		break;
879 	default:
880 		if (sk->sk_prot->ioctl)
881 			err = sk->sk_prot->ioctl(sk, cmd, arg);
882 		else
883 			err = -ENOIOCTLCMD;
884 		break;
885 	}
886 	return err;
887 }
888 EXPORT_SYMBOL(inet_ioctl);
889 
890 #ifdef CONFIG_COMPAT
891 int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
892 {
893 	struct sock *sk = sock->sk;
894 	int err = -ENOIOCTLCMD;
895 
896 	if (sk->sk_prot->compat_ioctl)
897 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
898 
899 	return err;
900 }
901 #endif
902 
903 const struct proto_ops inet_stream_ops = {
904 	.family		   = PF_INET,
905 	.owner		   = THIS_MODULE,
906 	.release	   = inet_release,
907 	.bind		   = inet_bind,
908 	.connect	   = inet_stream_connect,
909 	.socketpair	   = sock_no_socketpair,
910 	.accept		   = inet_accept,
911 	.getname	   = inet_getname,
912 	.poll		   = tcp_poll,
913 	.ioctl		   = inet_ioctl,
914 	.listen		   = inet_listen,
915 	.shutdown	   = inet_shutdown,
916 	.setsockopt	   = sock_common_setsockopt,
917 	.getsockopt	   = sock_common_getsockopt,
918 	.sendmsg	   = inet_sendmsg,
919 	.recvmsg	   = inet_recvmsg,
920 	.mmap		   = sock_no_mmap,
921 	.sendpage	   = inet_sendpage,
922 	.splice_read	   = tcp_splice_read,
923 #ifdef CONFIG_COMPAT
924 	.compat_setsockopt = compat_sock_common_setsockopt,
925 	.compat_getsockopt = compat_sock_common_getsockopt,
926 	.compat_ioctl	   = inet_compat_ioctl,
927 #endif
928 };
929 EXPORT_SYMBOL(inet_stream_ops);
930 
931 const struct proto_ops inet_dgram_ops = {
932 	.family		   = PF_INET,
933 	.owner		   = THIS_MODULE,
934 	.release	   = inet_release,
935 	.bind		   = inet_bind,
936 	.connect	   = inet_dgram_connect,
937 	.socketpair	   = sock_no_socketpair,
938 	.accept		   = sock_no_accept,
939 	.getname	   = inet_getname,
940 	.poll		   = udp_poll,
941 	.ioctl		   = inet_ioctl,
942 	.listen		   = sock_no_listen,
943 	.shutdown	   = inet_shutdown,
944 	.setsockopt	   = sock_common_setsockopt,
945 	.getsockopt	   = sock_common_getsockopt,
946 	.sendmsg	   = inet_sendmsg,
947 	.recvmsg	   = inet_recvmsg,
948 	.mmap		   = sock_no_mmap,
949 	.sendpage	   = inet_sendpage,
950 #ifdef CONFIG_COMPAT
951 	.compat_setsockopt = compat_sock_common_setsockopt,
952 	.compat_getsockopt = compat_sock_common_getsockopt,
953 	.compat_ioctl	   = inet_compat_ioctl,
954 #endif
955 };
956 EXPORT_SYMBOL(inet_dgram_ops);
957 
958 /*
959  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
960  * udp_poll
961  */
962 static const struct proto_ops inet_sockraw_ops = {
963 	.family		   = PF_INET,
964 	.owner		   = THIS_MODULE,
965 	.release	   = inet_release,
966 	.bind		   = inet_bind,
967 	.connect	   = inet_dgram_connect,
968 	.socketpair	   = sock_no_socketpair,
969 	.accept		   = sock_no_accept,
970 	.getname	   = inet_getname,
971 	.poll		   = datagram_poll,
972 	.ioctl		   = inet_ioctl,
973 	.listen		   = sock_no_listen,
974 	.shutdown	   = inet_shutdown,
975 	.setsockopt	   = sock_common_setsockopt,
976 	.getsockopt	   = sock_common_getsockopt,
977 	.sendmsg	   = inet_sendmsg,
978 	.recvmsg	   = inet_recvmsg,
979 	.mmap		   = sock_no_mmap,
980 	.sendpage	   = inet_sendpage,
981 #ifdef CONFIG_COMPAT
982 	.compat_setsockopt = compat_sock_common_setsockopt,
983 	.compat_getsockopt = compat_sock_common_getsockopt,
984 	.compat_ioctl	   = inet_compat_ioctl,
985 #endif
986 };
987 
988 static const struct net_proto_family inet_family_ops = {
989 	.family = PF_INET,
990 	.create = inet_create,
991 	.owner	= THIS_MODULE,
992 };
993 
994 /* Upon startup we insert all the elements in inetsw_array[] into
995  * the linked list inetsw.
996  */
997 static struct inet_protosw inetsw_array[] =
998 {
999 	{
1000 		.type =       SOCK_STREAM,
1001 		.protocol =   IPPROTO_TCP,
1002 		.prot =       &tcp_prot,
1003 		.ops =        &inet_stream_ops,
1004 		.no_check =   0,
1005 		.flags =      INET_PROTOSW_PERMANENT |
1006 			      INET_PROTOSW_ICSK,
1007 	},
1008 
1009 	{
1010 		.type =       SOCK_DGRAM,
1011 		.protocol =   IPPROTO_UDP,
1012 		.prot =       &udp_prot,
1013 		.ops =        &inet_dgram_ops,
1014 		.no_check =   UDP_CSUM_DEFAULT,
1015 		.flags =      INET_PROTOSW_PERMANENT,
1016        },
1017 
1018        {
1019 		.type =       SOCK_DGRAM,
1020 		.protocol =   IPPROTO_ICMP,
1021 		.prot =       &ping_prot,
1022 		.ops =        &inet_dgram_ops,
1023 		.no_check =   UDP_CSUM_DEFAULT,
1024 		.flags =      INET_PROTOSW_REUSE,
1025        },
1026 
1027        {
1028 	       .type =       SOCK_RAW,
1029 	       .protocol =   IPPROTO_IP,	/* wild card */
1030 	       .prot =       &raw_prot,
1031 	       .ops =        &inet_sockraw_ops,
1032 	       .no_check =   UDP_CSUM_DEFAULT,
1033 	       .flags =      INET_PROTOSW_REUSE,
1034        }
1035 };
1036 
1037 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1038 
1039 void inet_register_protosw(struct inet_protosw *p)
1040 {
1041 	struct list_head *lh;
1042 	struct inet_protosw *answer;
1043 	int protocol = p->protocol;
1044 	struct list_head *last_perm;
1045 
1046 	spin_lock_bh(&inetsw_lock);
1047 
1048 	if (p->type >= SOCK_MAX)
1049 		goto out_illegal;
1050 
1051 	/* If we are trying to override a permanent protocol, bail. */
1052 	answer = NULL;
1053 	last_perm = &inetsw[p->type];
1054 	list_for_each(lh, &inetsw[p->type]) {
1055 		answer = list_entry(lh, struct inet_protosw, list);
1056 
1057 		/* Check only the non-wild match. */
1058 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1059 			if (protocol == answer->protocol)
1060 				break;
1061 			last_perm = lh;
1062 		}
1063 
1064 		answer = NULL;
1065 	}
1066 	if (answer)
1067 		goto out_permanent;
1068 
1069 	/* Add the new entry after the last permanent entry if any, so that
1070 	 * the new entry does not override a permanent entry when matched with
1071 	 * a wild-card protocol. But it is allowed to override any existing
1072 	 * non-permanent entry.  This means that when we remove this entry, the
1073 	 * system automatically returns to the old behavior.
1074 	 */
1075 	list_add_rcu(&p->list, last_perm);
1076 out:
1077 	spin_unlock_bh(&inetsw_lock);
1078 
1079 	return;
1080 
1081 out_permanent:
1082 	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1083 	       protocol);
1084 	goto out;
1085 
1086 out_illegal:
1087 	printk(KERN_ERR
1088 	       "Ignoring attempt to register invalid socket type %d.\n",
1089 	       p->type);
1090 	goto out;
1091 }
1092 EXPORT_SYMBOL(inet_register_protosw);
1093 
1094 void inet_unregister_protosw(struct inet_protosw *p)
1095 {
1096 	if (INET_PROTOSW_PERMANENT & p->flags) {
1097 		printk(KERN_ERR
1098 		       "Attempt to unregister permanent protocol %d.\n",
1099 		       p->protocol);
1100 	} else {
1101 		spin_lock_bh(&inetsw_lock);
1102 		list_del_rcu(&p->list);
1103 		spin_unlock_bh(&inetsw_lock);
1104 
1105 		synchronize_net();
1106 	}
1107 }
1108 EXPORT_SYMBOL(inet_unregister_protosw);
1109 
1110 /*
1111  *      Shall we try to damage output packets if routing dev changes?
1112  */
1113 
1114 int sysctl_ip_dynaddr __read_mostly;
1115 
1116 static int inet_sk_reselect_saddr(struct sock *sk)
1117 {
1118 	struct inet_sock *inet = inet_sk(sk);
1119 	__be32 old_saddr = inet->inet_saddr;
1120 	__be32 daddr = inet->inet_daddr;
1121 	struct flowi4 *fl4;
1122 	struct rtable *rt;
1123 	__be32 new_saddr;
1124 	struct ip_options_rcu *inet_opt;
1125 
1126 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1127 					     sock_owned_by_user(sk));
1128 	if (inet_opt && inet_opt->opt.srr)
1129 		daddr = inet_opt->opt.faddr;
1130 
1131 	/* Query new route. */
1132 	fl4 = &inet->cork.fl.u.ip4;
1133 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1134 			      sk->sk_bound_dev_if, sk->sk_protocol,
1135 			      inet->inet_sport, inet->inet_dport, sk, false);
1136 	if (IS_ERR(rt))
1137 		return PTR_ERR(rt);
1138 
1139 	sk_setup_caps(sk, &rt->dst);
1140 
1141 	new_saddr = fl4->saddr;
1142 
1143 	if (new_saddr == old_saddr)
1144 		return 0;
1145 
1146 	if (sysctl_ip_dynaddr > 1) {
1147 		printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1148 		       __func__, &old_saddr, &new_saddr);
1149 	}
1150 
1151 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1152 
1153 	/*
1154 	 * XXX The only one ugly spot where we need to
1155 	 * XXX really change the sockets identity after
1156 	 * XXX it has entered the hashes. -DaveM
1157 	 *
1158 	 * Besides that, it does not check for connection
1159 	 * uniqueness. Wait for troubles.
1160 	 */
1161 	__sk_prot_rehash(sk);
1162 	return 0;
1163 }
1164 
1165 int inet_sk_rebuild_header(struct sock *sk)
1166 {
1167 	struct inet_sock *inet = inet_sk(sk);
1168 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1169 	__be32 daddr;
1170 	struct ip_options_rcu *inet_opt;
1171 	struct flowi4 *fl4;
1172 	int err;
1173 
1174 	/* Route is OK, nothing to do. */
1175 	if (rt)
1176 		return 0;
1177 
1178 	/* Reroute. */
1179 	rcu_read_lock();
1180 	inet_opt = rcu_dereference(inet->inet_opt);
1181 	daddr = inet->inet_daddr;
1182 	if (inet_opt && inet_opt->opt.srr)
1183 		daddr = inet_opt->opt.faddr;
1184 	rcu_read_unlock();
1185 	fl4 = &inet->cork.fl.u.ip4;
1186 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1187 				   inet->inet_dport, inet->inet_sport,
1188 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1189 				   sk->sk_bound_dev_if);
1190 	if (!IS_ERR(rt)) {
1191 		err = 0;
1192 		sk_setup_caps(sk, &rt->dst);
1193 	} else {
1194 		err = PTR_ERR(rt);
1195 
1196 		/* Routing failed... */
1197 		sk->sk_route_caps = 0;
1198 		/*
1199 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1200 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1201 		 */
1202 		if (!sysctl_ip_dynaddr ||
1203 		    sk->sk_state != TCP_SYN_SENT ||
1204 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1205 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1206 			sk->sk_err_soft = -err;
1207 	}
1208 
1209 	return err;
1210 }
1211 EXPORT_SYMBOL(inet_sk_rebuild_header);
1212 
1213 static int inet_gso_send_check(struct sk_buff *skb)
1214 {
1215 	const struct iphdr *iph;
1216 	const struct net_protocol *ops;
1217 	int proto;
1218 	int ihl;
1219 	int err = -EINVAL;
1220 
1221 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1222 		goto out;
1223 
1224 	iph = ip_hdr(skb);
1225 	ihl = iph->ihl * 4;
1226 	if (ihl < sizeof(*iph))
1227 		goto out;
1228 
1229 	if (unlikely(!pskb_may_pull(skb, ihl)))
1230 		goto out;
1231 
1232 	__skb_pull(skb, ihl);
1233 	skb_reset_transport_header(skb);
1234 	iph = ip_hdr(skb);
1235 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1236 	err = -EPROTONOSUPPORT;
1237 
1238 	rcu_read_lock();
1239 	ops = rcu_dereference(inet_protos[proto]);
1240 	if (likely(ops && ops->gso_send_check))
1241 		err = ops->gso_send_check(skb);
1242 	rcu_read_unlock();
1243 
1244 out:
1245 	return err;
1246 }
1247 
1248 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, u32 features)
1249 {
1250 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1251 	struct iphdr *iph;
1252 	const struct net_protocol *ops;
1253 	int proto;
1254 	int ihl;
1255 	int id;
1256 	unsigned int offset = 0;
1257 
1258 	if (!(features & NETIF_F_V4_CSUM))
1259 		features &= ~NETIF_F_SG;
1260 
1261 	if (unlikely(skb_shinfo(skb)->gso_type &
1262 		     ~(SKB_GSO_TCPV4 |
1263 		       SKB_GSO_UDP |
1264 		       SKB_GSO_DODGY |
1265 		       SKB_GSO_TCP_ECN |
1266 		       0)))
1267 		goto out;
1268 
1269 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1270 		goto out;
1271 
1272 	iph = ip_hdr(skb);
1273 	ihl = iph->ihl * 4;
1274 	if (ihl < sizeof(*iph))
1275 		goto out;
1276 
1277 	if (unlikely(!pskb_may_pull(skb, ihl)))
1278 		goto out;
1279 
1280 	__skb_pull(skb, ihl);
1281 	skb_reset_transport_header(skb);
1282 	iph = ip_hdr(skb);
1283 	id = ntohs(iph->id);
1284 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1285 	segs = ERR_PTR(-EPROTONOSUPPORT);
1286 
1287 	rcu_read_lock();
1288 	ops = rcu_dereference(inet_protos[proto]);
1289 	if (likely(ops && ops->gso_segment))
1290 		segs = ops->gso_segment(skb, features);
1291 	rcu_read_unlock();
1292 
1293 	if (!segs || IS_ERR(segs))
1294 		goto out;
1295 
1296 	skb = segs;
1297 	do {
1298 		iph = ip_hdr(skb);
1299 		if (proto == IPPROTO_UDP) {
1300 			iph->id = htons(id);
1301 			iph->frag_off = htons(offset >> 3);
1302 			if (skb->next != NULL)
1303 				iph->frag_off |= htons(IP_MF);
1304 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1305 		} else
1306 			iph->id = htons(id++);
1307 		iph->tot_len = htons(skb->len - skb->mac_len);
1308 		iph->check = 0;
1309 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1310 	} while ((skb = skb->next));
1311 
1312 out:
1313 	return segs;
1314 }
1315 
1316 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1317 					 struct sk_buff *skb)
1318 {
1319 	const struct net_protocol *ops;
1320 	struct sk_buff **pp = NULL;
1321 	struct sk_buff *p;
1322 	const struct iphdr *iph;
1323 	unsigned int hlen;
1324 	unsigned int off;
1325 	unsigned int id;
1326 	int flush = 1;
1327 	int proto;
1328 
1329 	off = skb_gro_offset(skb);
1330 	hlen = off + sizeof(*iph);
1331 	iph = skb_gro_header_fast(skb, off);
1332 	if (skb_gro_header_hard(skb, hlen)) {
1333 		iph = skb_gro_header_slow(skb, hlen, off);
1334 		if (unlikely(!iph))
1335 			goto out;
1336 	}
1337 
1338 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1339 
1340 	rcu_read_lock();
1341 	ops = rcu_dereference(inet_protos[proto]);
1342 	if (!ops || !ops->gro_receive)
1343 		goto out_unlock;
1344 
1345 	if (*(u8 *)iph != 0x45)
1346 		goto out_unlock;
1347 
1348 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1349 		goto out_unlock;
1350 
1351 	id = ntohl(*(__be32 *)&iph->id);
1352 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1353 	id >>= 16;
1354 
1355 	for (p = *head; p; p = p->next) {
1356 		struct iphdr *iph2;
1357 
1358 		if (!NAPI_GRO_CB(p)->same_flow)
1359 			continue;
1360 
1361 		iph2 = ip_hdr(p);
1362 
1363 		if ((iph->protocol ^ iph2->protocol) |
1364 		    (iph->tos ^ iph2->tos) |
1365 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1366 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1367 			NAPI_GRO_CB(p)->same_flow = 0;
1368 			continue;
1369 		}
1370 
1371 		/* All fields must match except length and checksum. */
1372 		NAPI_GRO_CB(p)->flush |=
1373 			(iph->ttl ^ iph2->ttl) |
1374 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1375 
1376 		NAPI_GRO_CB(p)->flush |= flush;
1377 	}
1378 
1379 	NAPI_GRO_CB(skb)->flush |= flush;
1380 	skb_gro_pull(skb, sizeof(*iph));
1381 	skb_set_transport_header(skb, skb_gro_offset(skb));
1382 
1383 	pp = ops->gro_receive(head, skb);
1384 
1385 out_unlock:
1386 	rcu_read_unlock();
1387 
1388 out:
1389 	NAPI_GRO_CB(skb)->flush |= flush;
1390 
1391 	return pp;
1392 }
1393 
1394 static int inet_gro_complete(struct sk_buff *skb)
1395 {
1396 	const struct net_protocol *ops;
1397 	struct iphdr *iph = ip_hdr(skb);
1398 	int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1399 	int err = -ENOSYS;
1400 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1401 
1402 	csum_replace2(&iph->check, iph->tot_len, newlen);
1403 	iph->tot_len = newlen;
1404 
1405 	rcu_read_lock();
1406 	ops = rcu_dereference(inet_protos[proto]);
1407 	if (WARN_ON(!ops || !ops->gro_complete))
1408 		goto out_unlock;
1409 
1410 	err = ops->gro_complete(skb);
1411 
1412 out_unlock:
1413 	rcu_read_unlock();
1414 
1415 	return err;
1416 }
1417 
1418 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1419 			 unsigned short type, unsigned char protocol,
1420 			 struct net *net)
1421 {
1422 	struct socket *sock;
1423 	int rc = sock_create_kern(family, type, protocol, &sock);
1424 
1425 	if (rc == 0) {
1426 		*sk = sock->sk;
1427 		(*sk)->sk_allocation = GFP_ATOMIC;
1428 		/*
1429 		 * Unhash it so that IP input processing does not even see it,
1430 		 * we do not wish this socket to see incoming packets.
1431 		 */
1432 		(*sk)->sk_prot->unhash(*sk);
1433 
1434 		sk_change_net(*sk, net);
1435 	}
1436 	return rc;
1437 }
1438 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1439 
1440 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1441 {
1442 	unsigned long res = 0;
1443 	int i, j;
1444 
1445 	for_each_possible_cpu(i) {
1446 		for (j = 0; j < SNMP_ARRAY_SZ; j++)
1447 			res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1448 	}
1449 	return res;
1450 }
1451 EXPORT_SYMBOL_GPL(snmp_fold_field);
1452 
1453 #if BITS_PER_LONG==32
1454 
1455 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1456 {
1457 	u64 res = 0;
1458 	int cpu;
1459 
1460 	for_each_possible_cpu(cpu) {
1461 		void *bhptr;
1462 		struct u64_stats_sync *syncp;
1463 		u64 v;
1464 		unsigned int start;
1465 
1466 		bhptr = per_cpu_ptr(mib[0], cpu);
1467 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1468 		do {
1469 			start = u64_stats_fetch_begin_bh(syncp);
1470 			v = *(((u64 *) bhptr) + offt);
1471 		} while (u64_stats_fetch_retry_bh(syncp, start));
1472 
1473 		res += v;
1474 	}
1475 	return res;
1476 }
1477 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1478 #endif
1479 
1480 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1481 {
1482 	BUG_ON(ptr == NULL);
1483 	ptr[0] = __alloc_percpu(mibsize, align);
1484 	if (!ptr[0])
1485 		return -ENOMEM;
1486 #if SNMP_ARRAY_SZ == 2
1487 	ptr[1] = __alloc_percpu(mibsize, align);
1488 	if (!ptr[1]) {
1489 		free_percpu(ptr[0]);
1490 		ptr[0] = NULL;
1491 		return -ENOMEM;
1492 	}
1493 #endif
1494 	return 0;
1495 }
1496 EXPORT_SYMBOL_GPL(snmp_mib_init);
1497 
1498 void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
1499 {
1500 	int i;
1501 
1502 	BUG_ON(ptr == NULL);
1503 	for (i = 0; i < SNMP_ARRAY_SZ; i++) {
1504 		free_percpu(ptr[i]);
1505 		ptr[i] = NULL;
1506 	}
1507 }
1508 EXPORT_SYMBOL_GPL(snmp_mib_free);
1509 
1510 #ifdef CONFIG_IP_MULTICAST
1511 static const struct net_protocol igmp_protocol = {
1512 	.handler =	igmp_rcv,
1513 	.netns_ok =	1,
1514 };
1515 #endif
1516 
1517 static const struct net_protocol tcp_protocol = {
1518 	.handler =	tcp_v4_rcv,
1519 	.err_handler =	tcp_v4_err,
1520 	.gso_send_check = tcp_v4_gso_send_check,
1521 	.gso_segment =	tcp_tso_segment,
1522 	.gro_receive =	tcp4_gro_receive,
1523 	.gro_complete =	tcp4_gro_complete,
1524 	.no_policy =	1,
1525 	.netns_ok =	1,
1526 };
1527 
1528 static const struct net_protocol udp_protocol = {
1529 	.handler =	udp_rcv,
1530 	.err_handler =	udp_err,
1531 	.gso_send_check = udp4_ufo_send_check,
1532 	.gso_segment = udp4_ufo_fragment,
1533 	.no_policy =	1,
1534 	.netns_ok =	1,
1535 };
1536 
1537 static const struct net_protocol icmp_protocol = {
1538 	.handler =	icmp_rcv,
1539 	.err_handler =	ping_err,
1540 	.no_policy =	1,
1541 	.netns_ok =	1,
1542 };
1543 
1544 static __net_init int ipv4_mib_init_net(struct net *net)
1545 {
1546 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1547 			  sizeof(struct tcp_mib),
1548 			  __alignof__(struct tcp_mib)) < 0)
1549 		goto err_tcp_mib;
1550 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1551 			  sizeof(struct ipstats_mib),
1552 			  __alignof__(struct ipstats_mib)) < 0)
1553 		goto err_ip_mib;
1554 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1555 			  sizeof(struct linux_mib),
1556 			  __alignof__(struct linux_mib)) < 0)
1557 		goto err_net_mib;
1558 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1559 			  sizeof(struct udp_mib),
1560 			  __alignof__(struct udp_mib)) < 0)
1561 		goto err_udp_mib;
1562 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1563 			  sizeof(struct udp_mib),
1564 			  __alignof__(struct udp_mib)) < 0)
1565 		goto err_udplite_mib;
1566 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1567 			  sizeof(struct icmp_mib),
1568 			  __alignof__(struct icmp_mib)) < 0)
1569 		goto err_icmp_mib;
1570 	if (snmp_mib_init((void __percpu **)net->mib.icmpmsg_statistics,
1571 			  sizeof(struct icmpmsg_mib),
1572 			  __alignof__(struct icmpmsg_mib)) < 0)
1573 		goto err_icmpmsg_mib;
1574 
1575 	tcp_mib_init(net);
1576 	return 0;
1577 
1578 err_icmpmsg_mib:
1579 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1580 err_icmp_mib:
1581 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1582 err_udplite_mib:
1583 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1584 err_udp_mib:
1585 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1586 err_net_mib:
1587 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1588 err_ip_mib:
1589 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1590 err_tcp_mib:
1591 	return -ENOMEM;
1592 }
1593 
1594 static __net_exit void ipv4_mib_exit_net(struct net *net)
1595 {
1596 	snmp_mib_free((void __percpu **)net->mib.icmpmsg_statistics);
1597 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1598 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1599 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1600 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1601 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1602 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1603 }
1604 
1605 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1606 	.init = ipv4_mib_init_net,
1607 	.exit = ipv4_mib_exit_net,
1608 };
1609 
1610 static int __init init_ipv4_mibs(void)
1611 {
1612 	return register_pernet_subsys(&ipv4_mib_ops);
1613 }
1614 
1615 static int ipv4_proc_init(void);
1616 
1617 /*
1618  *	IP protocol layer initialiser
1619  */
1620 
1621 static struct packet_type ip_packet_type __read_mostly = {
1622 	.type = cpu_to_be16(ETH_P_IP),
1623 	.func = ip_rcv,
1624 	.gso_send_check = inet_gso_send_check,
1625 	.gso_segment = inet_gso_segment,
1626 	.gro_receive = inet_gro_receive,
1627 	.gro_complete = inet_gro_complete,
1628 };
1629 
1630 static int __init inet_init(void)
1631 {
1632 	struct sk_buff *dummy_skb;
1633 	struct inet_protosw *q;
1634 	struct list_head *r;
1635 	int rc = -EINVAL;
1636 
1637 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1638 
1639 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1640 	if (!sysctl_local_reserved_ports)
1641 		goto out;
1642 
1643 	rc = proto_register(&tcp_prot, 1);
1644 	if (rc)
1645 		goto out_free_reserved_ports;
1646 
1647 	rc = proto_register(&udp_prot, 1);
1648 	if (rc)
1649 		goto out_unregister_tcp_proto;
1650 
1651 	rc = proto_register(&raw_prot, 1);
1652 	if (rc)
1653 		goto out_unregister_udp_proto;
1654 
1655 	rc = proto_register(&ping_prot, 1);
1656 	if (rc)
1657 		goto out_unregister_raw_proto;
1658 
1659 	/*
1660 	 *	Tell SOCKET that we are alive...
1661 	 */
1662 
1663 	(void)sock_register(&inet_family_ops);
1664 
1665 #ifdef CONFIG_SYSCTL
1666 	ip_static_sysctl_init();
1667 #endif
1668 
1669 	/*
1670 	 *	Add all the base protocols.
1671 	 */
1672 
1673 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1674 		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1675 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1676 		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1677 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1678 		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1679 #ifdef CONFIG_IP_MULTICAST
1680 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1681 		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1682 #endif
1683 
1684 	/* Register the socket-side information for inet_create. */
1685 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1686 		INIT_LIST_HEAD(r);
1687 
1688 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1689 		inet_register_protosw(q);
1690 
1691 	/*
1692 	 *	Set the ARP module up
1693 	 */
1694 
1695 	arp_init();
1696 
1697 	/*
1698 	 *	Set the IP module up
1699 	 */
1700 
1701 	ip_init();
1702 
1703 	tcp_v4_init();
1704 
1705 	/* Setup TCP slab cache for open requests. */
1706 	tcp_init();
1707 
1708 	/* Setup UDP memory threshold */
1709 	udp_init();
1710 
1711 	/* Add UDP-Lite (RFC 3828) */
1712 	udplite4_register();
1713 
1714 	ping_init();
1715 
1716 	/*
1717 	 *	Set the ICMP layer up
1718 	 */
1719 
1720 	if (icmp_init() < 0)
1721 		panic("Failed to create the ICMP control socket.\n");
1722 
1723 	/*
1724 	 *	Initialise the multicast router
1725 	 */
1726 #if defined(CONFIG_IP_MROUTE)
1727 	if (ip_mr_init())
1728 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1729 #endif
1730 	/*
1731 	 *	Initialise per-cpu ipv4 mibs
1732 	 */
1733 
1734 	if (init_ipv4_mibs())
1735 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1736 
1737 	ipv4_proc_init();
1738 
1739 	ipfrag_init();
1740 
1741 	dev_add_pack(&ip_packet_type);
1742 
1743 	rc = 0;
1744 out:
1745 	return rc;
1746 out_unregister_raw_proto:
1747 	proto_unregister(&raw_prot);
1748 out_unregister_udp_proto:
1749 	proto_unregister(&udp_prot);
1750 out_unregister_tcp_proto:
1751 	proto_unregister(&tcp_prot);
1752 out_free_reserved_ports:
1753 	kfree(sysctl_local_reserved_ports);
1754 	goto out;
1755 }
1756 
1757 fs_initcall(inet_init);
1758 
1759 /* ------------------------------------------------------------------------ */
1760 
1761 #ifdef CONFIG_PROC_FS
1762 static int __init ipv4_proc_init(void)
1763 {
1764 	int rc = 0;
1765 
1766 	if (raw_proc_init())
1767 		goto out_raw;
1768 	if (tcp4_proc_init())
1769 		goto out_tcp;
1770 	if (udp4_proc_init())
1771 		goto out_udp;
1772 	if (ping_proc_init())
1773 		goto out_ping;
1774 	if (ip_misc_proc_init())
1775 		goto out_misc;
1776 out:
1777 	return rc;
1778 out_misc:
1779 	ping_proc_exit();
1780 out_ping:
1781 	udp4_proc_exit();
1782 out_udp:
1783 	tcp4_proc_exit();
1784 out_tcp:
1785 	raw_proc_exit();
1786 out_raw:
1787 	rc = -ENOMEM;
1788 	goto out;
1789 }
1790 
1791 #else /* CONFIG_PROC_FS */
1792 static int __init ipv4_proc_init(void)
1793 {
1794 	return 0;
1795 }
1796 #endif /* CONFIG_PROC_FS */
1797 
1798 MODULE_ALIAS_NETPROTO(PF_INET);
1799 
1800