xref: /openbmc/linux/net/ipv4/af_inet.c (revision 089a49b6)
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 #define pr_fmt(fmt) "IPv4: " fmt
69 
70 #include <linux/err.h>
71 #include <linux/errno.h>
72 #include <linux/types.h>
73 #include <linux/socket.h>
74 #include <linux/in.h>
75 #include <linux/kernel.h>
76 #include <linux/module.h>
77 #include <linux/sched.h>
78 #include <linux/timer.h>
79 #include <linux/string.h>
80 #include <linux/sockios.h>
81 #include <linux/net.h>
82 #include <linux/capability.h>
83 #include <linux/fcntl.h>
84 #include <linux/mm.h>
85 #include <linux/interrupt.h>
86 #include <linux/stat.h>
87 #include <linux/init.h>
88 #include <linux/poll.h>
89 #include <linux/netfilter_ipv4.h>
90 #include <linux/random.h>
91 #include <linux/slab.h>
92 
93 #include <asm/uaccess.h>
94 
95 #include <linux/inet.h>
96 #include <linux/igmp.h>
97 #include <linux/inetdevice.h>
98 #include <linux/netdevice.h>
99 #include <net/checksum.h>
100 #include <net/ip.h>
101 #include <net/protocol.h>
102 #include <net/arp.h>
103 #include <net/route.h>
104 #include <net/ip_fib.h>
105 #include <net/inet_connection_sock.h>
106 #include <net/tcp.h>
107 #include <net/udp.h>
108 #include <net/udplite.h>
109 #include <net/ping.h>
110 #include <linux/skbuff.h>
111 #include <net/sock.h>
112 #include <net/raw.h>
113 #include <net/icmp.h>
114 #include <net/inet_common.h>
115 #include <net/xfrm.h>
116 #include <net/net_namespace.h>
117 #include <net/secure_seq.h>
118 #ifdef CONFIG_IP_MROUTE
119 #include <linux/mroute.h>
120 #endif
121 
122 
123 /* The inetsw table contains everything that inet_create needs to
124  * build a new socket.
125  */
126 static struct list_head inetsw[SOCK_MAX];
127 static DEFINE_SPINLOCK(inetsw_lock);
128 
129 struct ipv4_config ipv4_config;
130 EXPORT_SYMBOL(ipv4_config);
131 
132 /* New destruction routine */
133 
134 void inet_sock_destruct(struct sock *sk)
135 {
136 	struct inet_sock *inet = inet_sk(sk);
137 
138 	__skb_queue_purge(&sk->sk_receive_queue);
139 	__skb_queue_purge(&sk->sk_error_queue);
140 
141 	sk_mem_reclaim(sk);
142 
143 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
144 		pr_err("Attempt to release TCP socket in state %d %p\n",
145 		       sk->sk_state, sk);
146 		return;
147 	}
148 	if (!sock_flag(sk, SOCK_DEAD)) {
149 		pr_err("Attempt to release alive inet socket %p\n", sk);
150 		return;
151 	}
152 
153 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
154 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
155 	WARN_ON(sk->sk_wmem_queued);
156 	WARN_ON(sk->sk_forward_alloc);
157 
158 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
159 	dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
160 	dst_release(sk->sk_rx_dst);
161 	sk_refcnt_debug_dec(sk);
162 }
163 EXPORT_SYMBOL(inet_sock_destruct);
164 
165 /*
166  *	The routines beyond this point handle the behaviour of an AF_INET
167  *	socket object. Mostly it punts to the subprotocols of IP to do
168  *	the work.
169  */
170 
171 /*
172  *	Automatically bind an unbound socket.
173  */
174 
175 static int inet_autobind(struct sock *sk)
176 {
177 	struct inet_sock *inet;
178 	/* We may need to bind the socket. */
179 	lock_sock(sk);
180 	inet = inet_sk(sk);
181 	if (!inet->inet_num) {
182 		if (sk->sk_prot->get_port(sk, 0)) {
183 			release_sock(sk);
184 			return -EAGAIN;
185 		}
186 		inet->inet_sport = htons(inet->inet_num);
187 	}
188 	release_sock(sk);
189 	return 0;
190 }
191 
192 /*
193  *	Move a socket into listening state.
194  */
195 int inet_listen(struct socket *sock, int backlog)
196 {
197 	struct sock *sk = sock->sk;
198 	unsigned char old_state;
199 	int err;
200 
201 	lock_sock(sk);
202 
203 	err = -EINVAL;
204 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
205 		goto out;
206 
207 	old_state = sk->sk_state;
208 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
209 		goto out;
210 
211 	/* Really, if the socket is already in listen state
212 	 * we can only allow the backlog to be adjusted.
213 	 */
214 	if (old_state != TCP_LISTEN) {
215 		/* Check special setups for testing purpose to enable TFO w/o
216 		 * requiring TCP_FASTOPEN sockopt.
217 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
218 		 * Also fastopenq may already been allocated because this
219 		 * socket was in TCP_LISTEN state previously but was
220 		 * shutdown() (rather than close()).
221 		 */
222 		if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) != 0 &&
223 		    inet_csk(sk)->icsk_accept_queue.fastopenq == NULL) {
224 			if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) != 0)
225 				err = fastopen_init_queue(sk, backlog);
226 			else if ((sysctl_tcp_fastopen &
227 				  TFO_SERVER_WO_SOCKOPT2) != 0)
228 				err = fastopen_init_queue(sk,
229 				    ((uint)sysctl_tcp_fastopen) >> 16);
230 			else
231 				err = 0;
232 			if (err)
233 				goto out;
234 		}
235 		err = inet_csk_listen_start(sk, backlog);
236 		if (err)
237 			goto out;
238 	}
239 	sk->sk_max_ack_backlog = backlog;
240 	err = 0;
241 
242 out:
243 	release_sock(sk);
244 	return err;
245 }
246 EXPORT_SYMBOL(inet_listen);
247 
248 u32 inet_ehash_secret __read_mostly;
249 EXPORT_SYMBOL(inet_ehash_secret);
250 
251 u32 ipv6_hash_secret __read_mostly;
252 EXPORT_SYMBOL(ipv6_hash_secret);
253 
254 /*
255  * inet_ehash_secret must be set exactly once, and to a non nul value
256  * ipv6_hash_secret must be set exactly once.
257  */
258 void build_ehash_secret(void)
259 {
260 	u32 rnd;
261 
262 	do {
263 		get_random_bytes(&rnd, sizeof(rnd));
264 	} while (rnd == 0);
265 
266 	if (cmpxchg(&inet_ehash_secret, 0, rnd) == 0) {
267 		get_random_bytes(&ipv6_hash_secret, sizeof(ipv6_hash_secret));
268 		net_secret_init();
269 	}
270 }
271 EXPORT_SYMBOL(build_ehash_secret);
272 
273 /*
274  *	Create an inet socket.
275  */
276 
277 static int inet_create(struct net *net, struct socket *sock, int protocol,
278 		       int kern)
279 {
280 	struct sock *sk;
281 	struct inet_protosw *answer;
282 	struct inet_sock *inet;
283 	struct proto *answer_prot;
284 	unsigned char answer_flags;
285 	char answer_no_check;
286 	int try_loading_module = 0;
287 	int err;
288 
289 	if (unlikely(!inet_ehash_secret))
290 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
291 			build_ehash_secret();
292 
293 	sock->state = SS_UNCONNECTED;
294 
295 	/* Look for the requested type/protocol pair. */
296 lookup_protocol:
297 	err = -ESOCKTNOSUPPORT;
298 	rcu_read_lock();
299 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
300 
301 		err = 0;
302 		/* Check the non-wild match. */
303 		if (protocol == answer->protocol) {
304 			if (protocol != IPPROTO_IP)
305 				break;
306 		} else {
307 			/* Check for the two wild cases. */
308 			if (IPPROTO_IP == protocol) {
309 				protocol = answer->protocol;
310 				break;
311 			}
312 			if (IPPROTO_IP == answer->protocol)
313 				break;
314 		}
315 		err = -EPROTONOSUPPORT;
316 	}
317 
318 	if (unlikely(err)) {
319 		if (try_loading_module < 2) {
320 			rcu_read_unlock();
321 			/*
322 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
323 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
324 			 */
325 			if (++try_loading_module == 1)
326 				request_module("net-pf-%d-proto-%d-type-%d",
327 					       PF_INET, protocol, sock->type);
328 			/*
329 			 * Fall back to generic, e.g. net-pf-2-proto-132
330 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
331 			 */
332 			else
333 				request_module("net-pf-%d-proto-%d",
334 					       PF_INET, protocol);
335 			goto lookup_protocol;
336 		} else
337 			goto out_rcu_unlock;
338 	}
339 
340 	err = -EPERM;
341 	if (sock->type == SOCK_RAW && !kern &&
342 	    !ns_capable(net->user_ns, CAP_NET_RAW))
343 		goto out_rcu_unlock;
344 
345 	sock->ops = answer->ops;
346 	answer_prot = answer->prot;
347 	answer_no_check = answer->no_check;
348 	answer_flags = answer->flags;
349 	rcu_read_unlock();
350 
351 	WARN_ON(answer_prot->slab == NULL);
352 
353 	err = -ENOBUFS;
354 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
355 	if (sk == NULL)
356 		goto out;
357 
358 	err = 0;
359 	sk->sk_no_check = answer_no_check;
360 	if (INET_PROTOSW_REUSE & answer_flags)
361 		sk->sk_reuse = SK_CAN_REUSE;
362 
363 	inet = inet_sk(sk);
364 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
365 
366 	inet->nodefrag = 0;
367 
368 	if (SOCK_RAW == sock->type) {
369 		inet->inet_num = protocol;
370 		if (IPPROTO_RAW == protocol)
371 			inet->hdrincl = 1;
372 	}
373 
374 	if (ipv4_config.no_pmtu_disc)
375 		inet->pmtudisc = IP_PMTUDISC_DONT;
376 	else
377 		inet->pmtudisc = IP_PMTUDISC_WANT;
378 
379 	inet->inet_id = 0;
380 
381 	sock_init_data(sock, sk);
382 
383 	sk->sk_destruct	   = inet_sock_destruct;
384 	sk->sk_protocol	   = protocol;
385 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
386 
387 	inet->uc_ttl	= -1;
388 	inet->mc_loop	= 1;
389 	inet->mc_ttl	= 1;
390 	inet->mc_all	= 1;
391 	inet->mc_index	= 0;
392 	inet->mc_list	= NULL;
393 	inet->rcv_tos	= 0;
394 
395 	sk_refcnt_debug_inc(sk);
396 
397 	if (inet->inet_num) {
398 		/* It assumes that any protocol which allows
399 		 * the user to assign a number at socket
400 		 * creation time automatically
401 		 * shares.
402 		 */
403 		inet->inet_sport = htons(inet->inet_num);
404 		/* Add to protocol hash chains. */
405 		sk->sk_prot->hash(sk);
406 	}
407 
408 	if (sk->sk_prot->init) {
409 		err = sk->sk_prot->init(sk);
410 		if (err)
411 			sk_common_release(sk);
412 	}
413 out:
414 	return err;
415 out_rcu_unlock:
416 	rcu_read_unlock();
417 	goto out;
418 }
419 
420 
421 /*
422  *	The peer socket should always be NULL (or else). When we call this
423  *	function we are destroying the object and from then on nobody
424  *	should refer to it.
425  */
426 int inet_release(struct socket *sock)
427 {
428 	struct sock *sk = sock->sk;
429 
430 	if (sk) {
431 		long timeout;
432 
433 		sock_rps_reset_flow(sk);
434 
435 		/* Applications forget to leave groups before exiting */
436 		ip_mc_drop_socket(sk);
437 
438 		/* If linger is set, we don't return until the close
439 		 * is complete.  Otherwise we return immediately. The
440 		 * actually closing is done the same either way.
441 		 *
442 		 * If the close is due to the process exiting, we never
443 		 * linger..
444 		 */
445 		timeout = 0;
446 		if (sock_flag(sk, SOCK_LINGER) &&
447 		    !(current->flags & PF_EXITING))
448 			timeout = sk->sk_lingertime;
449 		sock->sk = NULL;
450 		sk->sk_prot->close(sk, timeout);
451 	}
452 	return 0;
453 }
454 EXPORT_SYMBOL(inet_release);
455 
456 /* It is off by default, see below. */
457 int sysctl_ip_nonlocal_bind __read_mostly;
458 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
459 
460 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
461 {
462 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
463 	struct sock *sk = sock->sk;
464 	struct inet_sock *inet = inet_sk(sk);
465 	struct net *net = sock_net(sk);
466 	unsigned short snum;
467 	int chk_addr_ret;
468 	int err;
469 
470 	/* If the socket has its own bind function then use it. (RAW) */
471 	if (sk->sk_prot->bind) {
472 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
473 		goto out;
474 	}
475 	err = -EINVAL;
476 	if (addr_len < sizeof(struct sockaddr_in))
477 		goto out;
478 
479 	if (addr->sin_family != AF_INET) {
480 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
481 		 * only if s_addr is INADDR_ANY.
482 		 */
483 		err = -EAFNOSUPPORT;
484 		if (addr->sin_family != AF_UNSPEC ||
485 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
486 			goto out;
487 	}
488 
489 	chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
490 
491 	/* Not specified by any standard per-se, however it breaks too
492 	 * many applications when removed.  It is unfortunate since
493 	 * allowing applications to make a non-local bind solves
494 	 * several problems with systems using dynamic addressing.
495 	 * (ie. your servers still start up even if your ISDN link
496 	 *  is temporarily down)
497 	 */
498 	err = -EADDRNOTAVAIL;
499 	if (!sysctl_ip_nonlocal_bind &&
500 	    !(inet->freebind || inet->transparent) &&
501 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
502 	    chk_addr_ret != RTN_LOCAL &&
503 	    chk_addr_ret != RTN_MULTICAST &&
504 	    chk_addr_ret != RTN_BROADCAST)
505 		goto out;
506 
507 	snum = ntohs(addr->sin_port);
508 	err = -EACCES;
509 	if (snum && snum < PROT_SOCK &&
510 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
511 		goto out;
512 
513 	/*      We keep a pair of addresses. rcv_saddr is the one
514 	 *      used by hash lookups, and saddr is used for transmit.
515 	 *
516 	 *      In the BSD API these are the same except where it
517 	 *      would be illegal to use them (multicast/broadcast) in
518 	 *      which case the sending device address is used.
519 	 */
520 	lock_sock(sk);
521 
522 	/* Check these errors (active socket, double bind). */
523 	err = -EINVAL;
524 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
525 		goto out_release_sock;
526 
527 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
528 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
529 		inet->inet_saddr = 0;  /* Use device */
530 
531 	/* Make sure we are allowed to bind here. */
532 	if (sk->sk_prot->get_port(sk, snum)) {
533 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
534 		err = -EADDRINUSE;
535 		goto out_release_sock;
536 	}
537 
538 	if (inet->inet_rcv_saddr)
539 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
540 	if (snum)
541 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
542 	inet->inet_sport = htons(inet->inet_num);
543 	inet->inet_daddr = 0;
544 	inet->inet_dport = 0;
545 	sk_dst_reset(sk);
546 	err = 0;
547 out_release_sock:
548 	release_sock(sk);
549 out:
550 	return err;
551 }
552 EXPORT_SYMBOL(inet_bind);
553 
554 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
555 		       int addr_len, int flags)
556 {
557 	struct sock *sk = sock->sk;
558 
559 	if (addr_len < sizeof(uaddr->sa_family))
560 		return -EINVAL;
561 	if (uaddr->sa_family == AF_UNSPEC)
562 		return sk->sk_prot->disconnect(sk, flags);
563 
564 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
565 		return -EAGAIN;
566 	return sk->sk_prot->connect(sk, uaddr, addr_len);
567 }
568 EXPORT_SYMBOL(inet_dgram_connect);
569 
570 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
571 {
572 	DEFINE_WAIT(wait);
573 
574 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
575 	sk->sk_write_pending += writebias;
576 
577 	/* Basic assumption: if someone sets sk->sk_err, he _must_
578 	 * change state of the socket from TCP_SYN_*.
579 	 * Connect() does not allow to get error notifications
580 	 * without closing the socket.
581 	 */
582 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
583 		release_sock(sk);
584 		timeo = schedule_timeout(timeo);
585 		lock_sock(sk);
586 		if (signal_pending(current) || !timeo)
587 			break;
588 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
589 	}
590 	finish_wait(sk_sleep(sk), &wait);
591 	sk->sk_write_pending -= writebias;
592 	return timeo;
593 }
594 
595 /*
596  *	Connect to a remote host. There is regrettably still a little
597  *	TCP 'magic' in here.
598  */
599 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
600 			  int addr_len, int flags)
601 {
602 	struct sock *sk = sock->sk;
603 	int err;
604 	long timeo;
605 
606 	if (addr_len < sizeof(uaddr->sa_family))
607 		return -EINVAL;
608 
609 	if (uaddr->sa_family == AF_UNSPEC) {
610 		err = sk->sk_prot->disconnect(sk, flags);
611 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
612 		goto out;
613 	}
614 
615 	switch (sock->state) {
616 	default:
617 		err = -EINVAL;
618 		goto out;
619 	case SS_CONNECTED:
620 		err = -EISCONN;
621 		goto out;
622 	case SS_CONNECTING:
623 		err = -EALREADY;
624 		/* Fall out of switch with err, set for this state */
625 		break;
626 	case SS_UNCONNECTED:
627 		err = -EISCONN;
628 		if (sk->sk_state != TCP_CLOSE)
629 			goto out;
630 
631 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
632 		if (err < 0)
633 			goto out;
634 
635 		sock->state = SS_CONNECTING;
636 
637 		/* Just entered SS_CONNECTING state; the only
638 		 * difference is that return value in non-blocking
639 		 * case is EINPROGRESS, rather than EALREADY.
640 		 */
641 		err = -EINPROGRESS;
642 		break;
643 	}
644 
645 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
646 
647 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
648 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
649 				tcp_sk(sk)->fastopen_req &&
650 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
651 
652 		/* Error code is set above */
653 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
654 			goto out;
655 
656 		err = sock_intr_errno(timeo);
657 		if (signal_pending(current))
658 			goto out;
659 	}
660 
661 	/* Connection was closed by RST, timeout, ICMP error
662 	 * or another process disconnected us.
663 	 */
664 	if (sk->sk_state == TCP_CLOSE)
665 		goto sock_error;
666 
667 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
668 	 * and error was received after socket entered established state.
669 	 * Hence, it is handled normally after connect() return successfully.
670 	 */
671 
672 	sock->state = SS_CONNECTED;
673 	err = 0;
674 out:
675 	return err;
676 
677 sock_error:
678 	err = sock_error(sk) ? : -ECONNABORTED;
679 	sock->state = SS_UNCONNECTED;
680 	if (sk->sk_prot->disconnect(sk, flags))
681 		sock->state = SS_DISCONNECTING;
682 	goto out;
683 }
684 EXPORT_SYMBOL(__inet_stream_connect);
685 
686 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
687 			int addr_len, int flags)
688 {
689 	int err;
690 
691 	lock_sock(sock->sk);
692 	err = __inet_stream_connect(sock, uaddr, addr_len, flags);
693 	release_sock(sock->sk);
694 	return err;
695 }
696 EXPORT_SYMBOL(inet_stream_connect);
697 
698 /*
699  *	Accept a pending connection. The TCP layer now gives BSD semantics.
700  */
701 
702 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
703 {
704 	struct sock *sk1 = sock->sk;
705 	int err = -EINVAL;
706 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
707 
708 	if (!sk2)
709 		goto do_err;
710 
711 	lock_sock(sk2);
712 
713 	sock_rps_record_flow(sk2);
714 	WARN_ON(!((1 << sk2->sk_state) &
715 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
716 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
717 
718 	sock_graft(sk2, newsock);
719 
720 	newsock->state = SS_CONNECTED;
721 	err = 0;
722 	release_sock(sk2);
723 do_err:
724 	return err;
725 }
726 EXPORT_SYMBOL(inet_accept);
727 
728 
729 /*
730  *	This does both peername and sockname.
731  */
732 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
733 			int *uaddr_len, int peer)
734 {
735 	struct sock *sk		= sock->sk;
736 	struct inet_sock *inet	= inet_sk(sk);
737 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
738 
739 	sin->sin_family = AF_INET;
740 	if (peer) {
741 		if (!inet->inet_dport ||
742 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
743 		     peer == 1))
744 			return -ENOTCONN;
745 		sin->sin_port = inet->inet_dport;
746 		sin->sin_addr.s_addr = inet->inet_daddr;
747 	} else {
748 		__be32 addr = inet->inet_rcv_saddr;
749 		if (!addr)
750 			addr = inet->inet_saddr;
751 		sin->sin_port = inet->inet_sport;
752 		sin->sin_addr.s_addr = addr;
753 	}
754 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
755 	*uaddr_len = sizeof(*sin);
756 	return 0;
757 }
758 EXPORT_SYMBOL(inet_getname);
759 
760 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
761 		 size_t size)
762 {
763 	struct sock *sk = sock->sk;
764 
765 	sock_rps_record_flow(sk);
766 
767 	/* We may need to bind the socket. */
768 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
769 	    inet_autobind(sk))
770 		return -EAGAIN;
771 
772 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
773 }
774 EXPORT_SYMBOL(inet_sendmsg);
775 
776 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
777 		      size_t size, int flags)
778 {
779 	struct sock *sk = sock->sk;
780 
781 	sock_rps_record_flow(sk);
782 
783 	/* We may need to bind the socket. */
784 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
785 	    inet_autobind(sk))
786 		return -EAGAIN;
787 
788 	if (sk->sk_prot->sendpage)
789 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
790 	return sock_no_sendpage(sock, page, offset, size, flags);
791 }
792 EXPORT_SYMBOL(inet_sendpage);
793 
794 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
795 		 size_t size, int flags)
796 {
797 	struct sock *sk = sock->sk;
798 	int addr_len = 0;
799 	int err;
800 
801 	sock_rps_record_flow(sk);
802 
803 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
804 				   flags & ~MSG_DONTWAIT, &addr_len);
805 	if (err >= 0)
806 		msg->msg_namelen = addr_len;
807 	return err;
808 }
809 EXPORT_SYMBOL(inet_recvmsg);
810 
811 int inet_shutdown(struct socket *sock, int how)
812 {
813 	struct sock *sk = sock->sk;
814 	int err = 0;
815 
816 	/* This should really check to make sure
817 	 * the socket is a TCP socket. (WHY AC...)
818 	 */
819 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
820 		       1->2 bit 2 snds.
821 		       2->3 */
822 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
823 		return -EINVAL;
824 
825 	lock_sock(sk);
826 	if (sock->state == SS_CONNECTING) {
827 		if ((1 << sk->sk_state) &
828 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
829 			sock->state = SS_DISCONNECTING;
830 		else
831 			sock->state = SS_CONNECTED;
832 	}
833 
834 	switch (sk->sk_state) {
835 	case TCP_CLOSE:
836 		err = -ENOTCONN;
837 		/* Hack to wake up other listeners, who can poll for
838 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
839 	default:
840 		sk->sk_shutdown |= how;
841 		if (sk->sk_prot->shutdown)
842 			sk->sk_prot->shutdown(sk, how);
843 		break;
844 
845 	/* Remaining two branches are temporary solution for missing
846 	 * close() in multithreaded environment. It is _not_ a good idea,
847 	 * but we have no choice until close() is repaired at VFS level.
848 	 */
849 	case TCP_LISTEN:
850 		if (!(how & RCV_SHUTDOWN))
851 			break;
852 		/* Fall through */
853 	case TCP_SYN_SENT:
854 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
855 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
856 		break;
857 	}
858 
859 	/* Wake up anyone sleeping in poll. */
860 	sk->sk_state_change(sk);
861 	release_sock(sk);
862 	return err;
863 }
864 EXPORT_SYMBOL(inet_shutdown);
865 
866 /*
867  *	ioctl() calls you can issue on an INET socket. Most of these are
868  *	device configuration and stuff and very rarely used. Some ioctls
869  *	pass on to the socket itself.
870  *
871  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
872  *	loads the devconfigure module does its configuring and unloads it.
873  *	There's a good 20K of config code hanging around the kernel.
874  */
875 
876 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
877 {
878 	struct sock *sk = sock->sk;
879 	int err = 0;
880 	struct net *net = sock_net(sk);
881 
882 	switch (cmd) {
883 	case SIOCGSTAMP:
884 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
885 		break;
886 	case SIOCGSTAMPNS:
887 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
888 		break;
889 	case SIOCADDRT:
890 	case SIOCDELRT:
891 	case SIOCRTMSG:
892 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
893 		break;
894 	case SIOCDARP:
895 	case SIOCGARP:
896 	case SIOCSARP:
897 		err = arp_ioctl(net, cmd, (void __user *)arg);
898 		break;
899 	case SIOCGIFADDR:
900 	case SIOCSIFADDR:
901 	case SIOCGIFBRDADDR:
902 	case SIOCSIFBRDADDR:
903 	case SIOCGIFNETMASK:
904 	case SIOCSIFNETMASK:
905 	case SIOCGIFDSTADDR:
906 	case SIOCSIFDSTADDR:
907 	case SIOCSIFPFLAGS:
908 	case SIOCGIFPFLAGS:
909 	case SIOCSIFFLAGS:
910 		err = devinet_ioctl(net, cmd, (void __user *)arg);
911 		break;
912 	default:
913 		if (sk->sk_prot->ioctl)
914 			err = sk->sk_prot->ioctl(sk, cmd, arg);
915 		else
916 			err = -ENOIOCTLCMD;
917 		break;
918 	}
919 	return err;
920 }
921 EXPORT_SYMBOL(inet_ioctl);
922 
923 #ifdef CONFIG_COMPAT
924 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
925 {
926 	struct sock *sk = sock->sk;
927 	int err = -ENOIOCTLCMD;
928 
929 	if (sk->sk_prot->compat_ioctl)
930 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
931 
932 	return err;
933 }
934 #endif
935 
936 const struct proto_ops inet_stream_ops = {
937 	.family		   = PF_INET,
938 	.owner		   = THIS_MODULE,
939 	.release	   = inet_release,
940 	.bind		   = inet_bind,
941 	.connect	   = inet_stream_connect,
942 	.socketpair	   = sock_no_socketpair,
943 	.accept		   = inet_accept,
944 	.getname	   = inet_getname,
945 	.poll		   = tcp_poll,
946 	.ioctl		   = inet_ioctl,
947 	.listen		   = inet_listen,
948 	.shutdown	   = inet_shutdown,
949 	.setsockopt	   = sock_common_setsockopt,
950 	.getsockopt	   = sock_common_getsockopt,
951 	.sendmsg	   = inet_sendmsg,
952 	.recvmsg	   = inet_recvmsg,
953 	.mmap		   = sock_no_mmap,
954 	.sendpage	   = inet_sendpage,
955 	.splice_read	   = tcp_splice_read,
956 #ifdef CONFIG_COMPAT
957 	.compat_setsockopt = compat_sock_common_setsockopt,
958 	.compat_getsockopt = compat_sock_common_getsockopt,
959 	.compat_ioctl	   = inet_compat_ioctl,
960 #endif
961 };
962 EXPORT_SYMBOL(inet_stream_ops);
963 
964 const struct proto_ops inet_dgram_ops = {
965 	.family		   = PF_INET,
966 	.owner		   = THIS_MODULE,
967 	.release	   = inet_release,
968 	.bind		   = inet_bind,
969 	.connect	   = inet_dgram_connect,
970 	.socketpair	   = sock_no_socketpair,
971 	.accept		   = sock_no_accept,
972 	.getname	   = inet_getname,
973 	.poll		   = udp_poll,
974 	.ioctl		   = inet_ioctl,
975 	.listen		   = sock_no_listen,
976 	.shutdown	   = inet_shutdown,
977 	.setsockopt	   = sock_common_setsockopt,
978 	.getsockopt	   = sock_common_getsockopt,
979 	.sendmsg	   = inet_sendmsg,
980 	.recvmsg	   = inet_recvmsg,
981 	.mmap		   = sock_no_mmap,
982 	.sendpage	   = inet_sendpage,
983 #ifdef CONFIG_COMPAT
984 	.compat_setsockopt = compat_sock_common_setsockopt,
985 	.compat_getsockopt = compat_sock_common_getsockopt,
986 	.compat_ioctl	   = inet_compat_ioctl,
987 #endif
988 };
989 EXPORT_SYMBOL(inet_dgram_ops);
990 
991 /*
992  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
993  * udp_poll
994  */
995 static const struct proto_ops inet_sockraw_ops = {
996 	.family		   = PF_INET,
997 	.owner		   = THIS_MODULE,
998 	.release	   = inet_release,
999 	.bind		   = inet_bind,
1000 	.connect	   = inet_dgram_connect,
1001 	.socketpair	   = sock_no_socketpair,
1002 	.accept		   = sock_no_accept,
1003 	.getname	   = inet_getname,
1004 	.poll		   = datagram_poll,
1005 	.ioctl		   = inet_ioctl,
1006 	.listen		   = sock_no_listen,
1007 	.shutdown	   = inet_shutdown,
1008 	.setsockopt	   = sock_common_setsockopt,
1009 	.getsockopt	   = sock_common_getsockopt,
1010 	.sendmsg	   = inet_sendmsg,
1011 	.recvmsg	   = inet_recvmsg,
1012 	.mmap		   = sock_no_mmap,
1013 	.sendpage	   = inet_sendpage,
1014 #ifdef CONFIG_COMPAT
1015 	.compat_setsockopt = compat_sock_common_setsockopt,
1016 	.compat_getsockopt = compat_sock_common_getsockopt,
1017 	.compat_ioctl	   = inet_compat_ioctl,
1018 #endif
1019 };
1020 
1021 static const struct net_proto_family inet_family_ops = {
1022 	.family = PF_INET,
1023 	.create = inet_create,
1024 	.owner	= THIS_MODULE,
1025 };
1026 
1027 /* Upon startup we insert all the elements in inetsw_array[] into
1028  * the linked list inetsw.
1029  */
1030 static struct inet_protosw inetsw_array[] =
1031 {
1032 	{
1033 		.type =       SOCK_STREAM,
1034 		.protocol =   IPPROTO_TCP,
1035 		.prot =       &tcp_prot,
1036 		.ops =        &inet_stream_ops,
1037 		.no_check =   0,
1038 		.flags =      INET_PROTOSW_PERMANENT |
1039 			      INET_PROTOSW_ICSK,
1040 	},
1041 
1042 	{
1043 		.type =       SOCK_DGRAM,
1044 		.protocol =   IPPROTO_UDP,
1045 		.prot =       &udp_prot,
1046 		.ops =        &inet_dgram_ops,
1047 		.no_check =   UDP_CSUM_DEFAULT,
1048 		.flags =      INET_PROTOSW_PERMANENT,
1049        },
1050 
1051        {
1052 		.type =       SOCK_DGRAM,
1053 		.protocol =   IPPROTO_ICMP,
1054 		.prot =       &ping_prot,
1055 		.ops =        &inet_dgram_ops,
1056 		.no_check =   UDP_CSUM_DEFAULT,
1057 		.flags =      INET_PROTOSW_REUSE,
1058        },
1059 
1060        {
1061 	       .type =       SOCK_RAW,
1062 	       .protocol =   IPPROTO_IP,	/* wild card */
1063 	       .prot =       &raw_prot,
1064 	       .ops =        &inet_sockraw_ops,
1065 	       .no_check =   UDP_CSUM_DEFAULT,
1066 	       .flags =      INET_PROTOSW_REUSE,
1067        }
1068 };
1069 
1070 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1071 
1072 void inet_register_protosw(struct inet_protosw *p)
1073 {
1074 	struct list_head *lh;
1075 	struct inet_protosw *answer;
1076 	int protocol = p->protocol;
1077 	struct list_head *last_perm;
1078 
1079 	spin_lock_bh(&inetsw_lock);
1080 
1081 	if (p->type >= SOCK_MAX)
1082 		goto out_illegal;
1083 
1084 	/* If we are trying to override a permanent protocol, bail. */
1085 	answer = NULL;
1086 	last_perm = &inetsw[p->type];
1087 	list_for_each(lh, &inetsw[p->type]) {
1088 		answer = list_entry(lh, struct inet_protosw, list);
1089 
1090 		/* Check only the non-wild match. */
1091 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1092 			if (protocol == answer->protocol)
1093 				break;
1094 			last_perm = lh;
1095 		}
1096 
1097 		answer = NULL;
1098 	}
1099 	if (answer)
1100 		goto out_permanent;
1101 
1102 	/* Add the new entry after the last permanent entry if any, so that
1103 	 * the new entry does not override a permanent entry when matched with
1104 	 * a wild-card protocol. But it is allowed to override any existing
1105 	 * non-permanent entry.  This means that when we remove this entry, the
1106 	 * system automatically returns to the old behavior.
1107 	 */
1108 	list_add_rcu(&p->list, last_perm);
1109 out:
1110 	spin_unlock_bh(&inetsw_lock);
1111 
1112 	return;
1113 
1114 out_permanent:
1115 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1116 	goto out;
1117 
1118 out_illegal:
1119 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1120 	       p->type);
1121 	goto out;
1122 }
1123 EXPORT_SYMBOL(inet_register_protosw);
1124 
1125 void inet_unregister_protosw(struct inet_protosw *p)
1126 {
1127 	if (INET_PROTOSW_PERMANENT & p->flags) {
1128 		pr_err("Attempt to unregister permanent protocol %d\n",
1129 		       p->protocol);
1130 	} else {
1131 		spin_lock_bh(&inetsw_lock);
1132 		list_del_rcu(&p->list);
1133 		spin_unlock_bh(&inetsw_lock);
1134 
1135 		synchronize_net();
1136 	}
1137 }
1138 EXPORT_SYMBOL(inet_unregister_protosw);
1139 
1140 /*
1141  *      Shall we try to damage output packets if routing dev changes?
1142  */
1143 
1144 int sysctl_ip_dynaddr __read_mostly;
1145 
1146 static int inet_sk_reselect_saddr(struct sock *sk)
1147 {
1148 	struct inet_sock *inet = inet_sk(sk);
1149 	__be32 old_saddr = inet->inet_saddr;
1150 	__be32 daddr = inet->inet_daddr;
1151 	struct flowi4 *fl4;
1152 	struct rtable *rt;
1153 	__be32 new_saddr;
1154 	struct ip_options_rcu *inet_opt;
1155 
1156 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1157 					     sock_owned_by_user(sk));
1158 	if (inet_opt && inet_opt->opt.srr)
1159 		daddr = inet_opt->opt.faddr;
1160 
1161 	/* Query new route. */
1162 	fl4 = &inet->cork.fl.u.ip4;
1163 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1164 			      sk->sk_bound_dev_if, sk->sk_protocol,
1165 			      inet->inet_sport, inet->inet_dport, sk, false);
1166 	if (IS_ERR(rt))
1167 		return PTR_ERR(rt);
1168 
1169 	sk_setup_caps(sk, &rt->dst);
1170 
1171 	new_saddr = fl4->saddr;
1172 
1173 	if (new_saddr == old_saddr)
1174 		return 0;
1175 
1176 	if (sysctl_ip_dynaddr > 1) {
1177 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1178 			__func__, &old_saddr, &new_saddr);
1179 	}
1180 
1181 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1182 
1183 	/*
1184 	 * XXX The only one ugly spot where we need to
1185 	 * XXX really change the sockets identity after
1186 	 * XXX it has entered the hashes. -DaveM
1187 	 *
1188 	 * Besides that, it does not check for connection
1189 	 * uniqueness. Wait for troubles.
1190 	 */
1191 	__sk_prot_rehash(sk);
1192 	return 0;
1193 }
1194 
1195 int inet_sk_rebuild_header(struct sock *sk)
1196 {
1197 	struct inet_sock *inet = inet_sk(sk);
1198 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1199 	__be32 daddr;
1200 	struct ip_options_rcu *inet_opt;
1201 	struct flowi4 *fl4;
1202 	int err;
1203 
1204 	/* Route is OK, nothing to do. */
1205 	if (rt)
1206 		return 0;
1207 
1208 	/* Reroute. */
1209 	rcu_read_lock();
1210 	inet_opt = rcu_dereference(inet->inet_opt);
1211 	daddr = inet->inet_daddr;
1212 	if (inet_opt && inet_opt->opt.srr)
1213 		daddr = inet_opt->opt.faddr;
1214 	rcu_read_unlock();
1215 	fl4 = &inet->cork.fl.u.ip4;
1216 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1217 				   inet->inet_dport, inet->inet_sport,
1218 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1219 				   sk->sk_bound_dev_if);
1220 	if (!IS_ERR(rt)) {
1221 		err = 0;
1222 		sk_setup_caps(sk, &rt->dst);
1223 	} else {
1224 		err = PTR_ERR(rt);
1225 
1226 		/* Routing failed... */
1227 		sk->sk_route_caps = 0;
1228 		/*
1229 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1230 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1231 		 */
1232 		if (!sysctl_ip_dynaddr ||
1233 		    sk->sk_state != TCP_SYN_SENT ||
1234 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1235 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1236 			sk->sk_err_soft = -err;
1237 	}
1238 
1239 	return err;
1240 }
1241 EXPORT_SYMBOL(inet_sk_rebuild_header);
1242 
1243 static int inet_gso_send_check(struct sk_buff *skb)
1244 {
1245 	const struct net_offload *ops;
1246 	const struct iphdr *iph;
1247 	int proto;
1248 	int ihl;
1249 	int err = -EINVAL;
1250 
1251 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1252 		goto out;
1253 
1254 	iph = ip_hdr(skb);
1255 	ihl = iph->ihl * 4;
1256 	if (ihl < sizeof(*iph))
1257 		goto out;
1258 
1259 	if (unlikely(!pskb_may_pull(skb, ihl)))
1260 		goto out;
1261 
1262 	__skb_pull(skb, ihl);
1263 	skb_reset_transport_header(skb);
1264 	iph = ip_hdr(skb);
1265 	proto = iph->protocol;
1266 	err = -EPROTONOSUPPORT;
1267 
1268 	rcu_read_lock();
1269 	ops = rcu_dereference(inet_offloads[proto]);
1270 	if (likely(ops && ops->callbacks.gso_send_check))
1271 		err = ops->callbacks.gso_send_check(skb);
1272 	rcu_read_unlock();
1273 
1274 out:
1275 	return err;
1276 }
1277 
1278 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1279 	netdev_features_t features)
1280 {
1281 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1282 	const struct net_offload *ops;
1283 	struct iphdr *iph;
1284 	int proto;
1285 	int ihl;
1286 	int id;
1287 	unsigned int offset = 0;
1288 	bool tunnel;
1289 
1290 	if (unlikely(skb_shinfo(skb)->gso_type &
1291 		     ~(SKB_GSO_TCPV4 |
1292 		       SKB_GSO_UDP |
1293 		       SKB_GSO_DODGY |
1294 		       SKB_GSO_TCP_ECN |
1295 		       SKB_GSO_GRE |
1296 		       SKB_GSO_TCPV6 |
1297 		       SKB_GSO_UDP_TUNNEL |
1298 		       SKB_GSO_MPLS |
1299 		       0)))
1300 		goto out;
1301 
1302 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1303 		goto out;
1304 
1305 	iph = ip_hdr(skb);
1306 	ihl = iph->ihl * 4;
1307 	if (ihl < sizeof(*iph))
1308 		goto out;
1309 
1310 	if (unlikely(!pskb_may_pull(skb, ihl)))
1311 		goto out;
1312 
1313 	tunnel = !!skb->encapsulation;
1314 
1315 	__skb_pull(skb, ihl);
1316 	skb_reset_transport_header(skb);
1317 	iph = ip_hdr(skb);
1318 	id = ntohs(iph->id);
1319 	proto = iph->protocol;
1320 	segs = ERR_PTR(-EPROTONOSUPPORT);
1321 
1322 	rcu_read_lock();
1323 	ops = rcu_dereference(inet_offloads[proto]);
1324 	if (likely(ops && ops->callbacks.gso_segment))
1325 		segs = ops->callbacks.gso_segment(skb, features);
1326 	rcu_read_unlock();
1327 
1328 	if (IS_ERR_OR_NULL(segs))
1329 		goto out;
1330 
1331 	skb = segs;
1332 	do {
1333 		iph = ip_hdr(skb);
1334 		if (!tunnel && proto == IPPROTO_UDP) {
1335 			iph->id = htons(id);
1336 			iph->frag_off = htons(offset >> 3);
1337 			if (skb->next != NULL)
1338 				iph->frag_off |= htons(IP_MF);
1339 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1340 		} else  {
1341 			iph->id = htons(id++);
1342 		}
1343 		iph->tot_len = htons(skb->len - skb->mac_len);
1344 		iph->check = 0;
1345 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1346 	} while ((skb = skb->next));
1347 
1348 out:
1349 	return segs;
1350 }
1351 
1352 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1353 					 struct sk_buff *skb)
1354 {
1355 	const struct net_offload *ops;
1356 	struct sk_buff **pp = NULL;
1357 	struct sk_buff *p;
1358 	const struct iphdr *iph;
1359 	unsigned int hlen;
1360 	unsigned int off;
1361 	unsigned int id;
1362 	int flush = 1;
1363 	int proto;
1364 
1365 	off = skb_gro_offset(skb);
1366 	hlen = off + sizeof(*iph);
1367 	iph = skb_gro_header_fast(skb, off);
1368 	if (skb_gro_header_hard(skb, hlen)) {
1369 		iph = skb_gro_header_slow(skb, hlen, off);
1370 		if (unlikely(!iph))
1371 			goto out;
1372 	}
1373 
1374 	proto = iph->protocol;
1375 
1376 	rcu_read_lock();
1377 	ops = rcu_dereference(inet_offloads[proto]);
1378 	if (!ops || !ops->callbacks.gro_receive)
1379 		goto out_unlock;
1380 
1381 	if (*(u8 *)iph != 0x45)
1382 		goto out_unlock;
1383 
1384 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1385 		goto out_unlock;
1386 
1387 	id = ntohl(*(__be32 *)&iph->id);
1388 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1389 	id >>= 16;
1390 
1391 	for (p = *head; p; p = p->next) {
1392 		struct iphdr *iph2;
1393 
1394 		if (!NAPI_GRO_CB(p)->same_flow)
1395 			continue;
1396 
1397 		iph2 = ip_hdr(p);
1398 
1399 		if ((iph->protocol ^ iph2->protocol) |
1400 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1401 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1402 			NAPI_GRO_CB(p)->same_flow = 0;
1403 			continue;
1404 		}
1405 
1406 		/* All fields must match except length and checksum. */
1407 		NAPI_GRO_CB(p)->flush |=
1408 			(iph->ttl ^ iph2->ttl) |
1409 			(iph->tos ^ iph2->tos) |
1410 			(__force int)((iph->frag_off ^ iph2->frag_off) & htons(IP_DF)) |
1411 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1412 
1413 		NAPI_GRO_CB(p)->flush |= flush;
1414 	}
1415 
1416 	NAPI_GRO_CB(skb)->flush |= flush;
1417 	skb_gro_pull(skb, sizeof(*iph));
1418 	skb_set_transport_header(skb, skb_gro_offset(skb));
1419 
1420 	pp = ops->callbacks.gro_receive(head, skb);
1421 
1422 out_unlock:
1423 	rcu_read_unlock();
1424 
1425 out:
1426 	NAPI_GRO_CB(skb)->flush |= flush;
1427 
1428 	return pp;
1429 }
1430 
1431 static int inet_gro_complete(struct sk_buff *skb)
1432 {
1433 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1434 	struct iphdr *iph = ip_hdr(skb);
1435 	const struct net_offload *ops;
1436 	int proto = iph->protocol;
1437 	int err = -ENOSYS;
1438 
1439 	csum_replace2(&iph->check, iph->tot_len, newlen);
1440 	iph->tot_len = newlen;
1441 
1442 	rcu_read_lock();
1443 	ops = rcu_dereference(inet_offloads[proto]);
1444 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1445 		goto out_unlock;
1446 
1447 	err = ops->callbacks.gro_complete(skb);
1448 
1449 out_unlock:
1450 	rcu_read_unlock();
1451 
1452 	return err;
1453 }
1454 
1455 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1456 			 unsigned short type, unsigned char protocol,
1457 			 struct net *net)
1458 {
1459 	struct socket *sock;
1460 	int rc = sock_create_kern(family, type, protocol, &sock);
1461 
1462 	if (rc == 0) {
1463 		*sk = sock->sk;
1464 		(*sk)->sk_allocation = GFP_ATOMIC;
1465 		/*
1466 		 * Unhash it so that IP input processing does not even see it,
1467 		 * we do not wish this socket to see incoming packets.
1468 		 */
1469 		(*sk)->sk_prot->unhash(*sk);
1470 
1471 		sk_change_net(*sk, net);
1472 	}
1473 	return rc;
1474 }
1475 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1476 
1477 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1478 {
1479 	unsigned long res = 0;
1480 	int i, j;
1481 
1482 	for_each_possible_cpu(i) {
1483 		for (j = 0; j < SNMP_ARRAY_SZ; j++)
1484 			res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1485 	}
1486 	return res;
1487 }
1488 EXPORT_SYMBOL_GPL(snmp_fold_field);
1489 
1490 #if BITS_PER_LONG==32
1491 
1492 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1493 {
1494 	u64 res = 0;
1495 	int cpu;
1496 
1497 	for_each_possible_cpu(cpu) {
1498 		void *bhptr;
1499 		struct u64_stats_sync *syncp;
1500 		u64 v;
1501 		unsigned int start;
1502 
1503 		bhptr = per_cpu_ptr(mib[0], cpu);
1504 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1505 		do {
1506 			start = u64_stats_fetch_begin_bh(syncp);
1507 			v = *(((u64 *) bhptr) + offt);
1508 		} while (u64_stats_fetch_retry_bh(syncp, start));
1509 
1510 		res += v;
1511 	}
1512 	return res;
1513 }
1514 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1515 #endif
1516 
1517 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1518 {
1519 	BUG_ON(ptr == NULL);
1520 	ptr[0] = __alloc_percpu(mibsize, align);
1521 	if (!ptr[0])
1522 		return -ENOMEM;
1523 #if SNMP_ARRAY_SZ == 2
1524 	ptr[1] = __alloc_percpu(mibsize, align);
1525 	if (!ptr[1]) {
1526 		free_percpu(ptr[0]);
1527 		ptr[0] = NULL;
1528 		return -ENOMEM;
1529 	}
1530 #endif
1531 	return 0;
1532 }
1533 EXPORT_SYMBOL_GPL(snmp_mib_init);
1534 
1535 #ifdef CONFIG_IP_MULTICAST
1536 static const struct net_protocol igmp_protocol = {
1537 	.handler =	igmp_rcv,
1538 	.netns_ok =	1,
1539 };
1540 #endif
1541 
1542 static const struct net_protocol tcp_protocol = {
1543 	.early_demux	=	tcp_v4_early_demux,
1544 	.handler	=	tcp_v4_rcv,
1545 	.err_handler	=	tcp_v4_err,
1546 	.no_policy	=	1,
1547 	.netns_ok	=	1,
1548 };
1549 
1550 static const struct net_protocol udp_protocol = {
1551 	.handler =	udp_rcv,
1552 	.err_handler =	udp_err,
1553 	.no_policy =	1,
1554 	.netns_ok =	1,
1555 };
1556 
1557 static const struct net_protocol icmp_protocol = {
1558 	.handler =	icmp_rcv,
1559 	.err_handler =	icmp_err,
1560 	.no_policy =	1,
1561 	.netns_ok =	1,
1562 };
1563 
1564 static __net_init int ipv4_mib_init_net(struct net *net)
1565 {
1566 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1567 			  sizeof(struct tcp_mib),
1568 			  __alignof__(struct tcp_mib)) < 0)
1569 		goto err_tcp_mib;
1570 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1571 			  sizeof(struct ipstats_mib),
1572 			  __alignof__(struct ipstats_mib)) < 0)
1573 		goto err_ip_mib;
1574 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1575 			  sizeof(struct linux_mib),
1576 			  __alignof__(struct linux_mib)) < 0)
1577 		goto err_net_mib;
1578 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1579 			  sizeof(struct udp_mib),
1580 			  __alignof__(struct udp_mib)) < 0)
1581 		goto err_udp_mib;
1582 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1583 			  sizeof(struct udp_mib),
1584 			  __alignof__(struct udp_mib)) < 0)
1585 		goto err_udplite_mib;
1586 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1587 			  sizeof(struct icmp_mib),
1588 			  __alignof__(struct icmp_mib)) < 0)
1589 		goto err_icmp_mib;
1590 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1591 					      GFP_KERNEL);
1592 	if (!net->mib.icmpmsg_statistics)
1593 		goto err_icmpmsg_mib;
1594 
1595 	tcp_mib_init(net);
1596 	return 0;
1597 
1598 err_icmpmsg_mib:
1599 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1600 err_icmp_mib:
1601 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1602 err_udplite_mib:
1603 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1604 err_udp_mib:
1605 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1606 err_net_mib:
1607 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1608 err_ip_mib:
1609 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1610 err_tcp_mib:
1611 	return -ENOMEM;
1612 }
1613 
1614 static __net_exit void ipv4_mib_exit_net(struct net *net)
1615 {
1616 	kfree(net->mib.icmpmsg_statistics);
1617 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1618 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1619 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1620 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1621 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1622 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1623 }
1624 
1625 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1626 	.init = ipv4_mib_init_net,
1627 	.exit = ipv4_mib_exit_net,
1628 };
1629 
1630 static int __init init_ipv4_mibs(void)
1631 {
1632 	return register_pernet_subsys(&ipv4_mib_ops);
1633 }
1634 
1635 static int ipv4_proc_init(void);
1636 
1637 /*
1638  *	IP protocol layer initialiser
1639  */
1640 
1641 static struct packet_offload ip_packet_offload __read_mostly = {
1642 	.type = cpu_to_be16(ETH_P_IP),
1643 	.callbacks = {
1644 		.gso_send_check = inet_gso_send_check,
1645 		.gso_segment = inet_gso_segment,
1646 		.gro_receive = inet_gro_receive,
1647 		.gro_complete = inet_gro_complete,
1648 	},
1649 };
1650 
1651 static int __init ipv4_offload_init(void)
1652 {
1653 	/*
1654 	 * Add offloads
1655 	 */
1656 	if (udpv4_offload_init() < 0)
1657 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1658 	if (tcpv4_offload_init() < 0)
1659 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1660 
1661 	dev_add_offload(&ip_packet_offload);
1662 	return 0;
1663 }
1664 
1665 fs_initcall(ipv4_offload_init);
1666 
1667 static struct packet_type ip_packet_type __read_mostly = {
1668 	.type = cpu_to_be16(ETH_P_IP),
1669 	.func = ip_rcv,
1670 };
1671 
1672 static int __init inet_init(void)
1673 {
1674 	struct inet_protosw *q;
1675 	struct list_head *r;
1676 	int rc = -EINVAL;
1677 
1678 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > FIELD_SIZEOF(struct sk_buff, cb));
1679 
1680 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1681 	if (!sysctl_local_reserved_ports)
1682 		goto out;
1683 
1684 	rc = proto_register(&tcp_prot, 1);
1685 	if (rc)
1686 		goto out_free_reserved_ports;
1687 
1688 	rc = proto_register(&udp_prot, 1);
1689 	if (rc)
1690 		goto out_unregister_tcp_proto;
1691 
1692 	rc = proto_register(&raw_prot, 1);
1693 	if (rc)
1694 		goto out_unregister_udp_proto;
1695 
1696 	rc = proto_register(&ping_prot, 1);
1697 	if (rc)
1698 		goto out_unregister_raw_proto;
1699 
1700 	/*
1701 	 *	Tell SOCKET that we are alive...
1702 	 */
1703 
1704 	(void)sock_register(&inet_family_ops);
1705 
1706 #ifdef CONFIG_SYSCTL
1707 	ip_static_sysctl_init();
1708 #endif
1709 
1710 	tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
1711 
1712 	/*
1713 	 *	Add all the base protocols.
1714 	 */
1715 
1716 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1717 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1718 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1719 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1720 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1721 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1722 #ifdef CONFIG_IP_MULTICAST
1723 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1724 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1725 #endif
1726 
1727 	/* Register the socket-side information for inet_create. */
1728 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1729 		INIT_LIST_HEAD(r);
1730 
1731 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1732 		inet_register_protosw(q);
1733 
1734 	/*
1735 	 *	Set the ARP module up
1736 	 */
1737 
1738 	arp_init();
1739 
1740 	/*
1741 	 *	Set the IP module up
1742 	 */
1743 
1744 	ip_init();
1745 
1746 	tcp_v4_init();
1747 
1748 	/* Setup TCP slab cache for open requests. */
1749 	tcp_init();
1750 
1751 	/* Setup UDP memory threshold */
1752 	udp_init();
1753 
1754 	/* Add UDP-Lite (RFC 3828) */
1755 	udplite4_register();
1756 
1757 	ping_init();
1758 
1759 	/*
1760 	 *	Set the ICMP layer up
1761 	 */
1762 
1763 	if (icmp_init() < 0)
1764 		panic("Failed to create the ICMP control socket.\n");
1765 
1766 	/*
1767 	 *	Initialise the multicast router
1768 	 */
1769 #if defined(CONFIG_IP_MROUTE)
1770 	if (ip_mr_init())
1771 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1772 #endif
1773 	/*
1774 	 *	Initialise per-cpu ipv4 mibs
1775 	 */
1776 
1777 	if (init_ipv4_mibs())
1778 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1779 
1780 	ipv4_proc_init();
1781 
1782 	ipfrag_init();
1783 
1784 	dev_add_pack(&ip_packet_type);
1785 
1786 	rc = 0;
1787 out:
1788 	return rc;
1789 out_unregister_raw_proto:
1790 	proto_unregister(&raw_prot);
1791 out_unregister_udp_proto:
1792 	proto_unregister(&udp_prot);
1793 out_unregister_tcp_proto:
1794 	proto_unregister(&tcp_prot);
1795 out_free_reserved_ports:
1796 	kfree(sysctl_local_reserved_ports);
1797 	goto out;
1798 }
1799 
1800 fs_initcall(inet_init);
1801 
1802 /* ------------------------------------------------------------------------ */
1803 
1804 #ifdef CONFIG_PROC_FS
1805 static int __init ipv4_proc_init(void)
1806 {
1807 	int rc = 0;
1808 
1809 	if (raw_proc_init())
1810 		goto out_raw;
1811 	if (tcp4_proc_init())
1812 		goto out_tcp;
1813 	if (udp4_proc_init())
1814 		goto out_udp;
1815 	if (ping_proc_init())
1816 		goto out_ping;
1817 	if (ip_misc_proc_init())
1818 		goto out_misc;
1819 out:
1820 	return rc;
1821 out_misc:
1822 	ping_proc_exit();
1823 out_ping:
1824 	udp4_proc_exit();
1825 out_udp:
1826 	tcp4_proc_exit();
1827 out_tcp:
1828 	raw_proc_exit();
1829 out_raw:
1830 	rc = -ENOMEM;
1831 	goto out;
1832 }
1833 
1834 #else /* CONFIG_PROC_FS */
1835 static int __init ipv4_proc_init(void)
1836 {
1837 	return 0;
1838 }
1839 #endif /* CONFIG_PROC_FS */
1840 
1841 MODULE_ALIAS_NETPROTO(PF_INET);
1842 
1843