xref: /openbmc/linux/net/ipv4/af_inet.c (revision f7777dcc)
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 }
269 EXPORT_SYMBOL(build_ehash_secret);
270 
271 /*
272  *	Create an inet socket.
273  */
274 
275 static int inet_create(struct net *net, struct socket *sock, int protocol,
276 		       int kern)
277 {
278 	struct sock *sk;
279 	struct inet_protosw *answer;
280 	struct inet_sock *inet;
281 	struct proto *answer_prot;
282 	unsigned char answer_flags;
283 	char answer_no_check;
284 	int try_loading_module = 0;
285 	int err;
286 
287 	if (unlikely(!inet_ehash_secret))
288 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
289 			build_ehash_secret();
290 
291 	sock->state = SS_UNCONNECTED;
292 
293 	/* Look for the requested type/protocol pair. */
294 lookup_protocol:
295 	err = -ESOCKTNOSUPPORT;
296 	rcu_read_lock();
297 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
298 
299 		err = 0;
300 		/* Check the non-wild match. */
301 		if (protocol == answer->protocol) {
302 			if (protocol != IPPROTO_IP)
303 				break;
304 		} else {
305 			/* Check for the two wild cases. */
306 			if (IPPROTO_IP == protocol) {
307 				protocol = answer->protocol;
308 				break;
309 			}
310 			if (IPPROTO_IP == answer->protocol)
311 				break;
312 		}
313 		err = -EPROTONOSUPPORT;
314 	}
315 
316 	if (unlikely(err)) {
317 		if (try_loading_module < 2) {
318 			rcu_read_unlock();
319 			/*
320 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
321 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
322 			 */
323 			if (++try_loading_module == 1)
324 				request_module("net-pf-%d-proto-%d-type-%d",
325 					       PF_INET, protocol, sock->type);
326 			/*
327 			 * Fall back to generic, e.g. net-pf-2-proto-132
328 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
329 			 */
330 			else
331 				request_module("net-pf-%d-proto-%d",
332 					       PF_INET, protocol);
333 			goto lookup_protocol;
334 		} else
335 			goto out_rcu_unlock;
336 	}
337 
338 	err = -EPERM;
339 	if (sock->type == SOCK_RAW && !kern &&
340 	    !ns_capable(net->user_ns, CAP_NET_RAW))
341 		goto out_rcu_unlock;
342 
343 	sock->ops = answer->ops;
344 	answer_prot = answer->prot;
345 	answer_no_check = answer->no_check;
346 	answer_flags = answer->flags;
347 	rcu_read_unlock();
348 
349 	WARN_ON(answer_prot->slab == NULL);
350 
351 	err = -ENOBUFS;
352 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
353 	if (sk == NULL)
354 		goto out;
355 
356 	err = 0;
357 	sk->sk_no_check = answer_no_check;
358 	if (INET_PROTOSW_REUSE & answer_flags)
359 		sk->sk_reuse = SK_CAN_REUSE;
360 
361 	inet = inet_sk(sk);
362 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
363 
364 	inet->nodefrag = 0;
365 
366 	if (SOCK_RAW == sock->type) {
367 		inet->inet_num = protocol;
368 		if (IPPROTO_RAW == protocol)
369 			inet->hdrincl = 1;
370 	}
371 
372 	if (ipv4_config.no_pmtu_disc)
373 		inet->pmtudisc = IP_PMTUDISC_DONT;
374 	else
375 		inet->pmtudisc = IP_PMTUDISC_WANT;
376 
377 	inet->inet_id = 0;
378 
379 	sock_init_data(sock, sk);
380 
381 	sk->sk_destruct	   = inet_sock_destruct;
382 	sk->sk_protocol	   = protocol;
383 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
384 
385 	inet->uc_ttl	= -1;
386 	inet->mc_loop	= 1;
387 	inet->mc_ttl	= 1;
388 	inet->mc_all	= 1;
389 	inet->mc_index	= 0;
390 	inet->mc_list	= NULL;
391 	inet->rcv_tos	= 0;
392 
393 	sk_refcnt_debug_inc(sk);
394 
395 	if (inet->inet_num) {
396 		/* It assumes that any protocol which allows
397 		 * the user to assign a number at socket
398 		 * creation time automatically
399 		 * shares.
400 		 */
401 		inet->inet_sport = htons(inet->inet_num);
402 		/* Add to protocol hash chains. */
403 		sk->sk_prot->hash(sk);
404 	}
405 
406 	if (sk->sk_prot->init) {
407 		err = sk->sk_prot->init(sk);
408 		if (err)
409 			sk_common_release(sk);
410 	}
411 out:
412 	return err;
413 out_rcu_unlock:
414 	rcu_read_unlock();
415 	goto out;
416 }
417 
418 
419 /*
420  *	The peer socket should always be NULL (or else). When we call this
421  *	function we are destroying the object and from then on nobody
422  *	should refer to it.
423  */
424 int inet_release(struct socket *sock)
425 {
426 	struct sock *sk = sock->sk;
427 
428 	if (sk) {
429 		long timeout;
430 
431 		sock_rps_reset_flow(sk);
432 
433 		/* Applications forget to leave groups before exiting */
434 		ip_mc_drop_socket(sk);
435 
436 		/* If linger is set, we don't return until the close
437 		 * is complete.  Otherwise we return immediately. The
438 		 * actually closing is done the same either way.
439 		 *
440 		 * If the close is due to the process exiting, we never
441 		 * linger..
442 		 */
443 		timeout = 0;
444 		if (sock_flag(sk, SOCK_LINGER) &&
445 		    !(current->flags & PF_EXITING))
446 			timeout = sk->sk_lingertime;
447 		sock->sk = NULL;
448 		sk->sk_prot->close(sk, timeout);
449 	}
450 	return 0;
451 }
452 EXPORT_SYMBOL(inet_release);
453 
454 /* It is off by default, see below. */
455 int sysctl_ip_nonlocal_bind __read_mostly;
456 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
457 
458 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
459 {
460 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
461 	struct sock *sk = sock->sk;
462 	struct inet_sock *inet = inet_sk(sk);
463 	struct net *net = sock_net(sk);
464 	unsigned short snum;
465 	int chk_addr_ret;
466 	int err;
467 
468 	/* If the socket has its own bind function then use it. (RAW) */
469 	if (sk->sk_prot->bind) {
470 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
471 		goto out;
472 	}
473 	err = -EINVAL;
474 	if (addr_len < sizeof(struct sockaddr_in))
475 		goto out;
476 
477 	if (addr->sin_family != AF_INET) {
478 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
479 		 * only if s_addr is INADDR_ANY.
480 		 */
481 		err = -EAFNOSUPPORT;
482 		if (addr->sin_family != AF_UNSPEC ||
483 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
484 			goto out;
485 	}
486 
487 	chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
488 
489 	/* Not specified by any standard per-se, however it breaks too
490 	 * many applications when removed.  It is unfortunate since
491 	 * allowing applications to make a non-local bind solves
492 	 * several problems with systems using dynamic addressing.
493 	 * (ie. your servers still start up even if your ISDN link
494 	 *  is temporarily down)
495 	 */
496 	err = -EADDRNOTAVAIL;
497 	if (!sysctl_ip_nonlocal_bind &&
498 	    !(inet->freebind || inet->transparent) &&
499 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
500 	    chk_addr_ret != RTN_LOCAL &&
501 	    chk_addr_ret != RTN_MULTICAST &&
502 	    chk_addr_ret != RTN_BROADCAST)
503 		goto out;
504 
505 	snum = ntohs(addr->sin_port);
506 	err = -EACCES;
507 	if (snum && snum < PROT_SOCK &&
508 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
509 		goto out;
510 
511 	/*      We keep a pair of addresses. rcv_saddr is the one
512 	 *      used by hash lookups, and saddr is used for transmit.
513 	 *
514 	 *      In the BSD API these are the same except where it
515 	 *      would be illegal to use them (multicast/broadcast) in
516 	 *      which case the sending device address is used.
517 	 */
518 	lock_sock(sk);
519 
520 	/* Check these errors (active socket, double bind). */
521 	err = -EINVAL;
522 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
523 		goto out_release_sock;
524 
525 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
526 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
527 		inet->inet_saddr = 0;  /* Use device */
528 
529 	/* Make sure we are allowed to bind here. */
530 	if (sk->sk_prot->get_port(sk, snum)) {
531 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
532 		err = -EADDRINUSE;
533 		goto out_release_sock;
534 	}
535 
536 	if (inet->inet_rcv_saddr)
537 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
538 	if (snum)
539 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
540 	inet->inet_sport = htons(inet->inet_num);
541 	inet->inet_daddr = 0;
542 	inet->inet_dport = 0;
543 	sk_dst_reset(sk);
544 	err = 0;
545 out_release_sock:
546 	release_sock(sk);
547 out:
548 	return err;
549 }
550 EXPORT_SYMBOL(inet_bind);
551 
552 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
553 		       int addr_len, int flags)
554 {
555 	struct sock *sk = sock->sk;
556 
557 	if (addr_len < sizeof(uaddr->sa_family))
558 		return -EINVAL;
559 	if (uaddr->sa_family == AF_UNSPEC)
560 		return sk->sk_prot->disconnect(sk, flags);
561 
562 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
563 		return -EAGAIN;
564 	return sk->sk_prot->connect(sk, uaddr, addr_len);
565 }
566 EXPORT_SYMBOL(inet_dgram_connect);
567 
568 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
569 {
570 	DEFINE_WAIT(wait);
571 
572 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
573 	sk->sk_write_pending += writebias;
574 
575 	/* Basic assumption: if someone sets sk->sk_err, he _must_
576 	 * change state of the socket from TCP_SYN_*.
577 	 * Connect() does not allow to get error notifications
578 	 * without closing the socket.
579 	 */
580 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
581 		release_sock(sk);
582 		timeo = schedule_timeout(timeo);
583 		lock_sock(sk);
584 		if (signal_pending(current) || !timeo)
585 			break;
586 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
587 	}
588 	finish_wait(sk_sleep(sk), &wait);
589 	sk->sk_write_pending -= writebias;
590 	return timeo;
591 }
592 
593 /*
594  *	Connect to a remote host. There is regrettably still a little
595  *	TCP 'magic' in here.
596  */
597 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
598 			  int addr_len, int flags)
599 {
600 	struct sock *sk = sock->sk;
601 	int err;
602 	long timeo;
603 
604 	if (addr_len < sizeof(uaddr->sa_family))
605 		return -EINVAL;
606 
607 	if (uaddr->sa_family == AF_UNSPEC) {
608 		err = sk->sk_prot->disconnect(sk, flags);
609 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
610 		goto out;
611 	}
612 
613 	switch (sock->state) {
614 	default:
615 		err = -EINVAL;
616 		goto out;
617 	case SS_CONNECTED:
618 		err = -EISCONN;
619 		goto out;
620 	case SS_CONNECTING:
621 		err = -EALREADY;
622 		/* Fall out of switch with err, set for this state */
623 		break;
624 	case SS_UNCONNECTED:
625 		err = -EISCONN;
626 		if (sk->sk_state != TCP_CLOSE)
627 			goto out;
628 
629 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
630 		if (err < 0)
631 			goto out;
632 
633 		sock->state = SS_CONNECTING;
634 
635 		/* Just entered SS_CONNECTING state; the only
636 		 * difference is that return value in non-blocking
637 		 * case is EINPROGRESS, rather than EALREADY.
638 		 */
639 		err = -EINPROGRESS;
640 		break;
641 	}
642 
643 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
644 
645 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
646 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
647 				tcp_sk(sk)->fastopen_req &&
648 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
649 
650 		/* Error code is set above */
651 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
652 			goto out;
653 
654 		err = sock_intr_errno(timeo);
655 		if (signal_pending(current))
656 			goto out;
657 	}
658 
659 	/* Connection was closed by RST, timeout, ICMP error
660 	 * or another process disconnected us.
661 	 */
662 	if (sk->sk_state == TCP_CLOSE)
663 		goto sock_error;
664 
665 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
666 	 * and error was received after socket entered established state.
667 	 * Hence, it is handled normally after connect() return successfully.
668 	 */
669 
670 	sock->state = SS_CONNECTED;
671 	err = 0;
672 out:
673 	return err;
674 
675 sock_error:
676 	err = sock_error(sk) ? : -ECONNABORTED;
677 	sock->state = SS_UNCONNECTED;
678 	if (sk->sk_prot->disconnect(sk, flags))
679 		sock->state = SS_DISCONNECTING;
680 	goto out;
681 }
682 EXPORT_SYMBOL(__inet_stream_connect);
683 
684 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
685 			int addr_len, int flags)
686 {
687 	int err;
688 
689 	lock_sock(sock->sk);
690 	err = __inet_stream_connect(sock, uaddr, addr_len, flags);
691 	release_sock(sock->sk);
692 	return err;
693 }
694 EXPORT_SYMBOL(inet_stream_connect);
695 
696 /*
697  *	Accept a pending connection. The TCP layer now gives BSD semantics.
698  */
699 
700 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
701 {
702 	struct sock *sk1 = sock->sk;
703 	int err = -EINVAL;
704 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
705 
706 	if (!sk2)
707 		goto do_err;
708 
709 	lock_sock(sk2);
710 
711 	sock_rps_record_flow(sk2);
712 	WARN_ON(!((1 << sk2->sk_state) &
713 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
714 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
715 
716 	sock_graft(sk2, newsock);
717 
718 	newsock->state = SS_CONNECTED;
719 	err = 0;
720 	release_sock(sk2);
721 do_err:
722 	return err;
723 }
724 EXPORT_SYMBOL(inet_accept);
725 
726 
727 /*
728  *	This does both peername and sockname.
729  */
730 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
731 			int *uaddr_len, int peer)
732 {
733 	struct sock *sk		= sock->sk;
734 	struct inet_sock *inet	= inet_sk(sk);
735 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
736 
737 	sin->sin_family = AF_INET;
738 	if (peer) {
739 		if (!inet->inet_dport ||
740 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
741 		     peer == 1))
742 			return -ENOTCONN;
743 		sin->sin_port = inet->inet_dport;
744 		sin->sin_addr.s_addr = inet->inet_daddr;
745 	} else {
746 		__be32 addr = inet->inet_rcv_saddr;
747 		if (!addr)
748 			addr = inet->inet_saddr;
749 		sin->sin_port = inet->inet_sport;
750 		sin->sin_addr.s_addr = addr;
751 	}
752 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
753 	*uaddr_len = sizeof(*sin);
754 	return 0;
755 }
756 EXPORT_SYMBOL(inet_getname);
757 
758 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
759 		 size_t size)
760 {
761 	struct sock *sk = sock->sk;
762 
763 	sock_rps_record_flow(sk);
764 
765 	/* We may need to bind the socket. */
766 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
767 	    inet_autobind(sk))
768 		return -EAGAIN;
769 
770 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
771 }
772 EXPORT_SYMBOL(inet_sendmsg);
773 
774 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
775 		      size_t size, int flags)
776 {
777 	struct sock *sk = sock->sk;
778 
779 	sock_rps_record_flow(sk);
780 
781 	/* We may need to bind the socket. */
782 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
783 	    inet_autobind(sk))
784 		return -EAGAIN;
785 
786 	if (sk->sk_prot->sendpage)
787 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
788 	return sock_no_sendpage(sock, page, offset, size, flags);
789 }
790 EXPORT_SYMBOL(inet_sendpage);
791 
792 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
793 		 size_t size, int flags)
794 {
795 	struct sock *sk = sock->sk;
796 	int addr_len = 0;
797 	int err;
798 
799 	sock_rps_record_flow(sk);
800 
801 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
802 				   flags & ~MSG_DONTWAIT, &addr_len);
803 	if (err >= 0)
804 		msg->msg_namelen = addr_len;
805 	return err;
806 }
807 EXPORT_SYMBOL(inet_recvmsg);
808 
809 int inet_shutdown(struct socket *sock, int how)
810 {
811 	struct sock *sk = sock->sk;
812 	int err = 0;
813 
814 	/* This should really check to make sure
815 	 * the socket is a TCP socket. (WHY AC...)
816 	 */
817 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
818 		       1->2 bit 2 snds.
819 		       2->3 */
820 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
821 		return -EINVAL;
822 
823 	lock_sock(sk);
824 	if (sock->state == SS_CONNECTING) {
825 		if ((1 << sk->sk_state) &
826 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
827 			sock->state = SS_DISCONNECTING;
828 		else
829 			sock->state = SS_CONNECTED;
830 	}
831 
832 	switch (sk->sk_state) {
833 	case TCP_CLOSE:
834 		err = -ENOTCONN;
835 		/* Hack to wake up other listeners, who can poll for
836 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
837 	default:
838 		sk->sk_shutdown |= how;
839 		if (sk->sk_prot->shutdown)
840 			sk->sk_prot->shutdown(sk, how);
841 		break;
842 
843 	/* Remaining two branches are temporary solution for missing
844 	 * close() in multithreaded environment. It is _not_ a good idea,
845 	 * but we have no choice until close() is repaired at VFS level.
846 	 */
847 	case TCP_LISTEN:
848 		if (!(how & RCV_SHUTDOWN))
849 			break;
850 		/* Fall through */
851 	case TCP_SYN_SENT:
852 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
853 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
854 		break;
855 	}
856 
857 	/* Wake up anyone sleeping in poll. */
858 	sk->sk_state_change(sk);
859 	release_sock(sk);
860 	return err;
861 }
862 EXPORT_SYMBOL(inet_shutdown);
863 
864 /*
865  *	ioctl() calls you can issue on an INET socket. Most of these are
866  *	device configuration and stuff and very rarely used. Some ioctls
867  *	pass on to the socket itself.
868  *
869  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
870  *	loads the devconfigure module does its configuring and unloads it.
871  *	There's a good 20K of config code hanging around the kernel.
872  */
873 
874 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
875 {
876 	struct sock *sk = sock->sk;
877 	int err = 0;
878 	struct net *net = sock_net(sk);
879 
880 	switch (cmd) {
881 	case SIOCGSTAMP:
882 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
883 		break;
884 	case SIOCGSTAMPNS:
885 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
886 		break;
887 	case SIOCADDRT:
888 	case SIOCDELRT:
889 	case SIOCRTMSG:
890 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
891 		break;
892 	case SIOCDARP:
893 	case SIOCGARP:
894 	case SIOCSARP:
895 		err = arp_ioctl(net, cmd, (void __user *)arg);
896 		break;
897 	case SIOCGIFADDR:
898 	case SIOCSIFADDR:
899 	case SIOCGIFBRDADDR:
900 	case SIOCSIFBRDADDR:
901 	case SIOCGIFNETMASK:
902 	case SIOCSIFNETMASK:
903 	case SIOCGIFDSTADDR:
904 	case SIOCSIFDSTADDR:
905 	case SIOCSIFPFLAGS:
906 	case SIOCGIFPFLAGS:
907 	case SIOCSIFFLAGS:
908 		err = devinet_ioctl(net, cmd, (void __user *)arg);
909 		break;
910 	default:
911 		if (sk->sk_prot->ioctl)
912 			err = sk->sk_prot->ioctl(sk, cmd, arg);
913 		else
914 			err = -ENOIOCTLCMD;
915 		break;
916 	}
917 	return err;
918 }
919 EXPORT_SYMBOL(inet_ioctl);
920 
921 #ifdef CONFIG_COMPAT
922 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
923 {
924 	struct sock *sk = sock->sk;
925 	int err = -ENOIOCTLCMD;
926 
927 	if (sk->sk_prot->compat_ioctl)
928 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
929 
930 	return err;
931 }
932 #endif
933 
934 const struct proto_ops inet_stream_ops = {
935 	.family		   = PF_INET,
936 	.owner		   = THIS_MODULE,
937 	.release	   = inet_release,
938 	.bind		   = inet_bind,
939 	.connect	   = inet_stream_connect,
940 	.socketpair	   = sock_no_socketpair,
941 	.accept		   = inet_accept,
942 	.getname	   = inet_getname,
943 	.poll		   = tcp_poll,
944 	.ioctl		   = inet_ioctl,
945 	.listen		   = inet_listen,
946 	.shutdown	   = inet_shutdown,
947 	.setsockopt	   = sock_common_setsockopt,
948 	.getsockopt	   = sock_common_getsockopt,
949 	.sendmsg	   = inet_sendmsg,
950 	.recvmsg	   = inet_recvmsg,
951 	.mmap		   = sock_no_mmap,
952 	.sendpage	   = inet_sendpage,
953 	.splice_read	   = tcp_splice_read,
954 #ifdef CONFIG_COMPAT
955 	.compat_setsockopt = compat_sock_common_setsockopt,
956 	.compat_getsockopt = compat_sock_common_getsockopt,
957 	.compat_ioctl	   = inet_compat_ioctl,
958 #endif
959 };
960 EXPORT_SYMBOL(inet_stream_ops);
961 
962 const struct proto_ops inet_dgram_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		   = udp_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 EXPORT_SYMBOL(inet_dgram_ops);
988 
989 /*
990  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
991  * udp_poll
992  */
993 static const struct proto_ops inet_sockraw_ops = {
994 	.family		   = PF_INET,
995 	.owner		   = THIS_MODULE,
996 	.release	   = inet_release,
997 	.bind		   = inet_bind,
998 	.connect	   = inet_dgram_connect,
999 	.socketpair	   = sock_no_socketpair,
1000 	.accept		   = sock_no_accept,
1001 	.getname	   = inet_getname,
1002 	.poll		   = datagram_poll,
1003 	.ioctl		   = inet_ioctl,
1004 	.listen		   = sock_no_listen,
1005 	.shutdown	   = inet_shutdown,
1006 	.setsockopt	   = sock_common_setsockopt,
1007 	.getsockopt	   = sock_common_getsockopt,
1008 	.sendmsg	   = inet_sendmsg,
1009 	.recvmsg	   = inet_recvmsg,
1010 	.mmap		   = sock_no_mmap,
1011 	.sendpage	   = inet_sendpage,
1012 #ifdef CONFIG_COMPAT
1013 	.compat_setsockopt = compat_sock_common_setsockopt,
1014 	.compat_getsockopt = compat_sock_common_getsockopt,
1015 	.compat_ioctl	   = inet_compat_ioctl,
1016 #endif
1017 };
1018 
1019 static const struct net_proto_family inet_family_ops = {
1020 	.family = PF_INET,
1021 	.create = inet_create,
1022 	.owner	= THIS_MODULE,
1023 };
1024 
1025 /* Upon startup we insert all the elements in inetsw_array[] into
1026  * the linked list inetsw.
1027  */
1028 static struct inet_protosw inetsw_array[] =
1029 {
1030 	{
1031 		.type =       SOCK_STREAM,
1032 		.protocol =   IPPROTO_TCP,
1033 		.prot =       &tcp_prot,
1034 		.ops =        &inet_stream_ops,
1035 		.no_check =   0,
1036 		.flags =      INET_PROTOSW_PERMANENT |
1037 			      INET_PROTOSW_ICSK,
1038 	},
1039 
1040 	{
1041 		.type =       SOCK_DGRAM,
1042 		.protocol =   IPPROTO_UDP,
1043 		.prot =       &udp_prot,
1044 		.ops =        &inet_dgram_ops,
1045 		.no_check =   UDP_CSUM_DEFAULT,
1046 		.flags =      INET_PROTOSW_PERMANENT,
1047        },
1048 
1049        {
1050 		.type =       SOCK_DGRAM,
1051 		.protocol =   IPPROTO_ICMP,
1052 		.prot =       &ping_prot,
1053 		.ops =        &inet_dgram_ops,
1054 		.no_check =   UDP_CSUM_DEFAULT,
1055 		.flags =      INET_PROTOSW_REUSE,
1056        },
1057 
1058        {
1059 	       .type =       SOCK_RAW,
1060 	       .protocol =   IPPROTO_IP,	/* wild card */
1061 	       .prot =       &raw_prot,
1062 	       .ops =        &inet_sockraw_ops,
1063 	       .no_check =   UDP_CSUM_DEFAULT,
1064 	       .flags =      INET_PROTOSW_REUSE,
1065        }
1066 };
1067 
1068 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1069 
1070 void inet_register_protosw(struct inet_protosw *p)
1071 {
1072 	struct list_head *lh;
1073 	struct inet_protosw *answer;
1074 	int protocol = p->protocol;
1075 	struct list_head *last_perm;
1076 
1077 	spin_lock_bh(&inetsw_lock);
1078 
1079 	if (p->type >= SOCK_MAX)
1080 		goto out_illegal;
1081 
1082 	/* If we are trying to override a permanent protocol, bail. */
1083 	answer = NULL;
1084 	last_perm = &inetsw[p->type];
1085 	list_for_each(lh, &inetsw[p->type]) {
1086 		answer = list_entry(lh, struct inet_protosw, list);
1087 
1088 		/* Check only the non-wild match. */
1089 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1090 			if (protocol == answer->protocol)
1091 				break;
1092 			last_perm = lh;
1093 		}
1094 
1095 		answer = NULL;
1096 	}
1097 	if (answer)
1098 		goto out_permanent;
1099 
1100 	/* Add the new entry after the last permanent entry if any, so that
1101 	 * the new entry does not override a permanent entry when matched with
1102 	 * a wild-card protocol. But it is allowed to override any existing
1103 	 * non-permanent entry.  This means that when we remove this entry, the
1104 	 * system automatically returns to the old behavior.
1105 	 */
1106 	list_add_rcu(&p->list, last_perm);
1107 out:
1108 	spin_unlock_bh(&inetsw_lock);
1109 
1110 	return;
1111 
1112 out_permanent:
1113 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1114 	goto out;
1115 
1116 out_illegal:
1117 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1118 	       p->type);
1119 	goto out;
1120 }
1121 EXPORT_SYMBOL(inet_register_protosw);
1122 
1123 void inet_unregister_protosw(struct inet_protosw *p)
1124 {
1125 	if (INET_PROTOSW_PERMANENT & p->flags) {
1126 		pr_err("Attempt to unregister permanent protocol %d\n",
1127 		       p->protocol);
1128 	} else {
1129 		spin_lock_bh(&inetsw_lock);
1130 		list_del_rcu(&p->list);
1131 		spin_unlock_bh(&inetsw_lock);
1132 
1133 		synchronize_net();
1134 	}
1135 }
1136 EXPORT_SYMBOL(inet_unregister_protosw);
1137 
1138 /*
1139  *      Shall we try to damage output packets if routing dev changes?
1140  */
1141 
1142 int sysctl_ip_dynaddr __read_mostly;
1143 
1144 static int inet_sk_reselect_saddr(struct sock *sk)
1145 {
1146 	struct inet_sock *inet = inet_sk(sk);
1147 	__be32 old_saddr = inet->inet_saddr;
1148 	__be32 daddr = inet->inet_daddr;
1149 	struct flowi4 *fl4;
1150 	struct rtable *rt;
1151 	__be32 new_saddr;
1152 	struct ip_options_rcu *inet_opt;
1153 
1154 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1155 					     sock_owned_by_user(sk));
1156 	if (inet_opt && inet_opt->opt.srr)
1157 		daddr = inet_opt->opt.faddr;
1158 
1159 	/* Query new route. */
1160 	fl4 = &inet->cork.fl.u.ip4;
1161 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1162 			      sk->sk_bound_dev_if, sk->sk_protocol,
1163 			      inet->inet_sport, inet->inet_dport, sk, false);
1164 	if (IS_ERR(rt))
1165 		return PTR_ERR(rt);
1166 
1167 	sk_setup_caps(sk, &rt->dst);
1168 
1169 	new_saddr = fl4->saddr;
1170 
1171 	if (new_saddr == old_saddr)
1172 		return 0;
1173 
1174 	if (sysctl_ip_dynaddr > 1) {
1175 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1176 			__func__, &old_saddr, &new_saddr);
1177 	}
1178 
1179 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1180 
1181 	/*
1182 	 * XXX The only one ugly spot where we need to
1183 	 * XXX really change the sockets identity after
1184 	 * XXX it has entered the hashes. -DaveM
1185 	 *
1186 	 * Besides that, it does not check for connection
1187 	 * uniqueness. Wait for troubles.
1188 	 */
1189 	__sk_prot_rehash(sk);
1190 	return 0;
1191 }
1192 
1193 int inet_sk_rebuild_header(struct sock *sk)
1194 {
1195 	struct inet_sock *inet = inet_sk(sk);
1196 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1197 	__be32 daddr;
1198 	struct ip_options_rcu *inet_opt;
1199 	struct flowi4 *fl4;
1200 	int err;
1201 
1202 	/* Route is OK, nothing to do. */
1203 	if (rt)
1204 		return 0;
1205 
1206 	/* Reroute. */
1207 	rcu_read_lock();
1208 	inet_opt = rcu_dereference(inet->inet_opt);
1209 	daddr = inet->inet_daddr;
1210 	if (inet_opt && inet_opt->opt.srr)
1211 		daddr = inet_opt->opt.faddr;
1212 	rcu_read_unlock();
1213 	fl4 = &inet->cork.fl.u.ip4;
1214 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1215 				   inet->inet_dport, inet->inet_sport,
1216 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1217 				   sk->sk_bound_dev_if);
1218 	if (!IS_ERR(rt)) {
1219 		err = 0;
1220 		sk_setup_caps(sk, &rt->dst);
1221 	} else {
1222 		err = PTR_ERR(rt);
1223 
1224 		/* Routing failed... */
1225 		sk->sk_route_caps = 0;
1226 		/*
1227 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1228 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1229 		 */
1230 		if (!sysctl_ip_dynaddr ||
1231 		    sk->sk_state != TCP_SYN_SENT ||
1232 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1233 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1234 			sk->sk_err_soft = -err;
1235 	}
1236 
1237 	return err;
1238 }
1239 EXPORT_SYMBOL(inet_sk_rebuild_header);
1240 
1241 static int inet_gso_send_check(struct sk_buff *skb)
1242 {
1243 	const struct net_offload *ops;
1244 	const struct iphdr *iph;
1245 	int proto;
1246 	int ihl;
1247 	int err = -EINVAL;
1248 
1249 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1250 		goto out;
1251 
1252 	iph = ip_hdr(skb);
1253 	ihl = iph->ihl * 4;
1254 	if (ihl < sizeof(*iph))
1255 		goto out;
1256 
1257 	if (unlikely(!pskb_may_pull(skb, ihl)))
1258 		goto out;
1259 
1260 	__skb_pull(skb, ihl);
1261 	skb_reset_transport_header(skb);
1262 	iph = ip_hdr(skb);
1263 	proto = iph->protocol;
1264 	err = -EPROTONOSUPPORT;
1265 
1266 	rcu_read_lock();
1267 	ops = rcu_dereference(inet_offloads[proto]);
1268 	if (likely(ops && ops->callbacks.gso_send_check))
1269 		err = ops->callbacks.gso_send_check(skb);
1270 	rcu_read_unlock();
1271 
1272 out:
1273 	return err;
1274 }
1275 
1276 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1277 	netdev_features_t features)
1278 {
1279 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1280 	const struct net_offload *ops;
1281 	struct iphdr *iph;
1282 	int proto;
1283 	int ihl;
1284 	int id;
1285 	unsigned int offset = 0;
1286 	bool tunnel;
1287 
1288 	if (unlikely(skb_shinfo(skb)->gso_type &
1289 		     ~(SKB_GSO_TCPV4 |
1290 		       SKB_GSO_UDP |
1291 		       SKB_GSO_DODGY |
1292 		       SKB_GSO_TCP_ECN |
1293 		       SKB_GSO_GRE |
1294 		       SKB_GSO_TCPV6 |
1295 		       SKB_GSO_UDP_TUNNEL |
1296 		       SKB_GSO_MPLS |
1297 		       0)))
1298 		goto out;
1299 
1300 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1301 		goto out;
1302 
1303 	iph = ip_hdr(skb);
1304 	ihl = iph->ihl * 4;
1305 	if (ihl < sizeof(*iph))
1306 		goto out;
1307 
1308 	if (unlikely(!pskb_may_pull(skb, ihl)))
1309 		goto out;
1310 
1311 	tunnel = !!skb->encapsulation;
1312 
1313 	__skb_pull(skb, ihl);
1314 	skb_reset_transport_header(skb);
1315 	iph = ip_hdr(skb);
1316 	id = ntohs(iph->id);
1317 	proto = iph->protocol;
1318 	segs = ERR_PTR(-EPROTONOSUPPORT);
1319 
1320 	rcu_read_lock();
1321 	ops = rcu_dereference(inet_offloads[proto]);
1322 	if (likely(ops && ops->callbacks.gso_segment))
1323 		segs = ops->callbacks.gso_segment(skb, features);
1324 	rcu_read_unlock();
1325 
1326 	if (IS_ERR_OR_NULL(segs))
1327 		goto out;
1328 
1329 	skb = segs;
1330 	do {
1331 		iph = ip_hdr(skb);
1332 		if (!tunnel && proto == IPPROTO_UDP) {
1333 			iph->id = htons(id);
1334 			iph->frag_off = htons(offset >> 3);
1335 			if (skb->next != NULL)
1336 				iph->frag_off |= htons(IP_MF);
1337 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1338 		} else  {
1339 			iph->id = htons(id++);
1340 		}
1341 		iph->tot_len = htons(skb->len - skb->mac_len);
1342 		iph->check = 0;
1343 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1344 	} while ((skb = skb->next));
1345 
1346 out:
1347 	return segs;
1348 }
1349 
1350 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1351 					 struct sk_buff *skb)
1352 {
1353 	const struct net_offload *ops;
1354 	struct sk_buff **pp = NULL;
1355 	struct sk_buff *p;
1356 	const struct iphdr *iph;
1357 	unsigned int hlen;
1358 	unsigned int off;
1359 	unsigned int id;
1360 	int flush = 1;
1361 	int proto;
1362 
1363 	off = skb_gro_offset(skb);
1364 	hlen = off + sizeof(*iph);
1365 	iph = skb_gro_header_fast(skb, off);
1366 	if (skb_gro_header_hard(skb, hlen)) {
1367 		iph = skb_gro_header_slow(skb, hlen, off);
1368 		if (unlikely(!iph))
1369 			goto out;
1370 	}
1371 
1372 	proto = iph->protocol;
1373 
1374 	rcu_read_lock();
1375 	ops = rcu_dereference(inet_offloads[proto]);
1376 	if (!ops || !ops->callbacks.gro_receive)
1377 		goto out_unlock;
1378 
1379 	if (*(u8 *)iph != 0x45)
1380 		goto out_unlock;
1381 
1382 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1383 		goto out_unlock;
1384 
1385 	id = ntohl(*(__be32 *)&iph->id);
1386 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1387 	id >>= 16;
1388 
1389 	for (p = *head; p; p = p->next) {
1390 		struct iphdr *iph2;
1391 
1392 		if (!NAPI_GRO_CB(p)->same_flow)
1393 			continue;
1394 
1395 		iph2 = ip_hdr(p);
1396 
1397 		if ((iph->protocol ^ iph2->protocol) |
1398 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1399 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1400 			NAPI_GRO_CB(p)->same_flow = 0;
1401 			continue;
1402 		}
1403 
1404 		/* All fields must match except length and checksum. */
1405 		NAPI_GRO_CB(p)->flush |=
1406 			(iph->ttl ^ iph2->ttl) |
1407 			(iph->tos ^ iph2->tos) |
1408 			(__force int)((iph->frag_off ^ iph2->frag_off) & htons(IP_DF)) |
1409 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1410 
1411 		NAPI_GRO_CB(p)->flush |= flush;
1412 	}
1413 
1414 	NAPI_GRO_CB(skb)->flush |= flush;
1415 	skb_gro_pull(skb, sizeof(*iph));
1416 	skb_set_transport_header(skb, skb_gro_offset(skb));
1417 
1418 	pp = ops->callbacks.gro_receive(head, skb);
1419 
1420 out_unlock:
1421 	rcu_read_unlock();
1422 
1423 out:
1424 	NAPI_GRO_CB(skb)->flush |= flush;
1425 
1426 	return pp;
1427 }
1428 
1429 static int inet_gro_complete(struct sk_buff *skb)
1430 {
1431 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1432 	struct iphdr *iph = ip_hdr(skb);
1433 	const struct net_offload *ops;
1434 	int proto = iph->protocol;
1435 	int err = -ENOSYS;
1436 
1437 	csum_replace2(&iph->check, iph->tot_len, newlen);
1438 	iph->tot_len = newlen;
1439 
1440 	rcu_read_lock();
1441 	ops = rcu_dereference(inet_offloads[proto]);
1442 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1443 		goto out_unlock;
1444 
1445 	err = ops->callbacks.gro_complete(skb);
1446 
1447 out_unlock:
1448 	rcu_read_unlock();
1449 
1450 	return err;
1451 }
1452 
1453 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1454 			 unsigned short type, unsigned char protocol,
1455 			 struct net *net)
1456 {
1457 	struct socket *sock;
1458 	int rc = sock_create_kern(family, type, protocol, &sock);
1459 
1460 	if (rc == 0) {
1461 		*sk = sock->sk;
1462 		(*sk)->sk_allocation = GFP_ATOMIC;
1463 		/*
1464 		 * Unhash it so that IP input processing does not even see it,
1465 		 * we do not wish this socket to see incoming packets.
1466 		 */
1467 		(*sk)->sk_prot->unhash(*sk);
1468 
1469 		sk_change_net(*sk, net);
1470 	}
1471 	return rc;
1472 }
1473 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1474 
1475 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1476 {
1477 	unsigned long res = 0;
1478 	int i, j;
1479 
1480 	for_each_possible_cpu(i) {
1481 		for (j = 0; j < SNMP_ARRAY_SZ; j++)
1482 			res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1483 	}
1484 	return res;
1485 }
1486 EXPORT_SYMBOL_GPL(snmp_fold_field);
1487 
1488 #if BITS_PER_LONG==32
1489 
1490 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1491 {
1492 	u64 res = 0;
1493 	int cpu;
1494 
1495 	for_each_possible_cpu(cpu) {
1496 		void *bhptr;
1497 		struct u64_stats_sync *syncp;
1498 		u64 v;
1499 		unsigned int start;
1500 
1501 		bhptr = per_cpu_ptr(mib[0], cpu);
1502 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1503 		do {
1504 			start = u64_stats_fetch_begin_bh(syncp);
1505 			v = *(((u64 *) bhptr) + offt);
1506 		} while (u64_stats_fetch_retry_bh(syncp, start));
1507 
1508 		res += v;
1509 	}
1510 	return res;
1511 }
1512 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1513 #endif
1514 
1515 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1516 {
1517 	BUG_ON(ptr == NULL);
1518 	ptr[0] = __alloc_percpu(mibsize, align);
1519 	if (!ptr[0])
1520 		return -ENOMEM;
1521 #if SNMP_ARRAY_SZ == 2
1522 	ptr[1] = __alloc_percpu(mibsize, align);
1523 	if (!ptr[1]) {
1524 		free_percpu(ptr[0]);
1525 		ptr[0] = NULL;
1526 		return -ENOMEM;
1527 	}
1528 #endif
1529 	return 0;
1530 }
1531 EXPORT_SYMBOL_GPL(snmp_mib_init);
1532 
1533 #ifdef CONFIG_IP_MULTICAST
1534 static const struct net_protocol igmp_protocol = {
1535 	.handler =	igmp_rcv,
1536 	.netns_ok =	1,
1537 };
1538 #endif
1539 
1540 static const struct net_protocol tcp_protocol = {
1541 	.early_demux	=	tcp_v4_early_demux,
1542 	.handler	=	tcp_v4_rcv,
1543 	.err_handler	=	tcp_v4_err,
1544 	.no_policy	=	1,
1545 	.netns_ok	=	1,
1546 };
1547 
1548 static const struct net_protocol udp_protocol = {
1549 	.handler =	udp_rcv,
1550 	.err_handler =	udp_err,
1551 	.no_policy =	1,
1552 	.netns_ok =	1,
1553 };
1554 
1555 static const struct net_protocol icmp_protocol = {
1556 	.handler =	icmp_rcv,
1557 	.err_handler =	icmp_err,
1558 	.no_policy =	1,
1559 	.netns_ok =	1,
1560 };
1561 
1562 static __net_init int ipv4_mib_init_net(struct net *net)
1563 {
1564 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1565 			  sizeof(struct tcp_mib),
1566 			  __alignof__(struct tcp_mib)) < 0)
1567 		goto err_tcp_mib;
1568 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1569 			  sizeof(struct ipstats_mib),
1570 			  __alignof__(struct ipstats_mib)) < 0)
1571 		goto err_ip_mib;
1572 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1573 			  sizeof(struct linux_mib),
1574 			  __alignof__(struct linux_mib)) < 0)
1575 		goto err_net_mib;
1576 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1577 			  sizeof(struct udp_mib),
1578 			  __alignof__(struct udp_mib)) < 0)
1579 		goto err_udp_mib;
1580 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1581 			  sizeof(struct udp_mib),
1582 			  __alignof__(struct udp_mib)) < 0)
1583 		goto err_udplite_mib;
1584 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1585 			  sizeof(struct icmp_mib),
1586 			  __alignof__(struct icmp_mib)) < 0)
1587 		goto err_icmp_mib;
1588 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1589 					      GFP_KERNEL);
1590 	if (!net->mib.icmpmsg_statistics)
1591 		goto err_icmpmsg_mib;
1592 
1593 	tcp_mib_init(net);
1594 	return 0;
1595 
1596 err_icmpmsg_mib:
1597 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1598 err_icmp_mib:
1599 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1600 err_udplite_mib:
1601 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1602 err_udp_mib:
1603 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1604 err_net_mib:
1605 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1606 err_ip_mib:
1607 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1608 err_tcp_mib:
1609 	return -ENOMEM;
1610 }
1611 
1612 static __net_exit void ipv4_mib_exit_net(struct net *net)
1613 {
1614 	kfree(net->mib.icmpmsg_statistics);
1615 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1616 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1617 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1618 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1619 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1620 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1621 }
1622 
1623 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1624 	.init = ipv4_mib_init_net,
1625 	.exit = ipv4_mib_exit_net,
1626 };
1627 
1628 static int __init init_ipv4_mibs(void)
1629 {
1630 	return register_pernet_subsys(&ipv4_mib_ops);
1631 }
1632 
1633 static int ipv4_proc_init(void);
1634 
1635 /*
1636  *	IP protocol layer initialiser
1637  */
1638 
1639 static struct packet_offload ip_packet_offload __read_mostly = {
1640 	.type = cpu_to_be16(ETH_P_IP),
1641 	.callbacks = {
1642 		.gso_send_check = inet_gso_send_check,
1643 		.gso_segment = inet_gso_segment,
1644 		.gro_receive = inet_gro_receive,
1645 		.gro_complete = inet_gro_complete,
1646 	},
1647 };
1648 
1649 static int __init ipv4_offload_init(void)
1650 {
1651 	/*
1652 	 * Add offloads
1653 	 */
1654 	if (udpv4_offload_init() < 0)
1655 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1656 	if (tcpv4_offload_init() < 0)
1657 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1658 
1659 	dev_add_offload(&ip_packet_offload);
1660 	return 0;
1661 }
1662 
1663 fs_initcall(ipv4_offload_init);
1664 
1665 static struct packet_type ip_packet_type __read_mostly = {
1666 	.type = cpu_to_be16(ETH_P_IP),
1667 	.func = ip_rcv,
1668 };
1669 
1670 static int __init inet_init(void)
1671 {
1672 	struct inet_protosw *q;
1673 	struct list_head *r;
1674 	int rc = -EINVAL;
1675 
1676 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > FIELD_SIZEOF(struct sk_buff, cb));
1677 
1678 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1679 	if (!sysctl_local_reserved_ports)
1680 		goto out;
1681 
1682 	rc = proto_register(&tcp_prot, 1);
1683 	if (rc)
1684 		goto out_free_reserved_ports;
1685 
1686 	rc = proto_register(&udp_prot, 1);
1687 	if (rc)
1688 		goto out_unregister_tcp_proto;
1689 
1690 	rc = proto_register(&raw_prot, 1);
1691 	if (rc)
1692 		goto out_unregister_udp_proto;
1693 
1694 	rc = proto_register(&ping_prot, 1);
1695 	if (rc)
1696 		goto out_unregister_raw_proto;
1697 
1698 	/*
1699 	 *	Tell SOCKET that we are alive...
1700 	 */
1701 
1702 	(void)sock_register(&inet_family_ops);
1703 
1704 #ifdef CONFIG_SYSCTL
1705 	ip_static_sysctl_init();
1706 #endif
1707 
1708 	tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
1709 
1710 	/*
1711 	 *	Add all the base protocols.
1712 	 */
1713 
1714 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1715 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1716 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1717 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1718 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1719 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1720 #ifdef CONFIG_IP_MULTICAST
1721 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1722 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1723 #endif
1724 
1725 	/* Register the socket-side information for inet_create. */
1726 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1727 		INIT_LIST_HEAD(r);
1728 
1729 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1730 		inet_register_protosw(q);
1731 
1732 	/*
1733 	 *	Set the ARP module up
1734 	 */
1735 
1736 	arp_init();
1737 
1738 	/*
1739 	 *	Set the IP module up
1740 	 */
1741 
1742 	ip_init();
1743 
1744 	tcp_v4_init();
1745 
1746 	/* Setup TCP slab cache for open requests. */
1747 	tcp_init();
1748 
1749 	/* Setup UDP memory threshold */
1750 	udp_init();
1751 
1752 	/* Add UDP-Lite (RFC 3828) */
1753 	udplite4_register();
1754 
1755 	ping_init();
1756 
1757 	/*
1758 	 *	Set the ICMP layer up
1759 	 */
1760 
1761 	if (icmp_init() < 0)
1762 		panic("Failed to create the ICMP control socket.\n");
1763 
1764 	/*
1765 	 *	Initialise the multicast router
1766 	 */
1767 #if defined(CONFIG_IP_MROUTE)
1768 	if (ip_mr_init())
1769 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1770 #endif
1771 	/*
1772 	 *	Initialise per-cpu ipv4 mibs
1773 	 */
1774 
1775 	if (init_ipv4_mibs())
1776 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1777 
1778 	ipv4_proc_init();
1779 
1780 	ipfrag_init();
1781 
1782 	dev_add_pack(&ip_packet_type);
1783 
1784 	rc = 0;
1785 out:
1786 	return rc;
1787 out_unregister_raw_proto:
1788 	proto_unregister(&raw_prot);
1789 out_unregister_udp_proto:
1790 	proto_unregister(&udp_prot);
1791 out_unregister_tcp_proto:
1792 	proto_unregister(&tcp_prot);
1793 out_free_reserved_ports:
1794 	kfree(sysctl_local_reserved_ports);
1795 	goto out;
1796 }
1797 
1798 fs_initcall(inet_init);
1799 
1800 /* ------------------------------------------------------------------------ */
1801 
1802 #ifdef CONFIG_PROC_FS
1803 static int __init ipv4_proc_init(void)
1804 {
1805 	int rc = 0;
1806 
1807 	if (raw_proc_init())
1808 		goto out_raw;
1809 	if (tcp4_proc_init())
1810 		goto out_tcp;
1811 	if (udp4_proc_init())
1812 		goto out_udp;
1813 	if (ping_proc_init())
1814 		goto out_ping;
1815 	if (ip_misc_proc_init())
1816 		goto out_misc;
1817 out:
1818 	return rc;
1819 out_misc:
1820 	ping_proc_exit();
1821 out_ping:
1822 	udp4_proc_exit();
1823 out_udp:
1824 	tcp4_proc_exit();
1825 out_tcp:
1826 	raw_proc_exit();
1827 out_raw:
1828 	rc = -ENOMEM;
1829 	goto out;
1830 }
1831 
1832 #else /* CONFIG_PROC_FS */
1833 static int __init ipv4_proc_init(void)
1834 {
1835 	return 0;
1836 }
1837 #endif /* CONFIG_PROC_FS */
1838 
1839 MODULE_ALIAS_NETPROTO(PF_INET);
1840 
1841