xref: /openbmc/linux/net/ipv4/af_inet.c (revision a8a28aff)
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 /* New destruction routine */
130 
131 void inet_sock_destruct(struct sock *sk)
132 {
133 	struct inet_sock *inet = inet_sk(sk);
134 
135 	__skb_queue_purge(&sk->sk_receive_queue);
136 	__skb_queue_purge(&sk->sk_error_queue);
137 
138 	sk_mem_reclaim(sk);
139 
140 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
141 		pr_err("Attempt to release TCP socket in state %d %p\n",
142 		       sk->sk_state, sk);
143 		return;
144 	}
145 	if (!sock_flag(sk, SOCK_DEAD)) {
146 		pr_err("Attempt to release alive inet socket %p\n", sk);
147 		return;
148 	}
149 
150 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
151 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
152 	WARN_ON(sk->sk_wmem_queued);
153 	WARN_ON(sk->sk_forward_alloc);
154 
155 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
156 	dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
157 	dst_release(sk->sk_rx_dst);
158 	sk_refcnt_debug_dec(sk);
159 }
160 EXPORT_SYMBOL(inet_sock_destruct);
161 
162 /*
163  *	The routines beyond this point handle the behaviour of an AF_INET
164  *	socket object. Mostly it punts to the subprotocols of IP to do
165  *	the work.
166  */
167 
168 /*
169  *	Automatically bind an unbound socket.
170  */
171 
172 static int inet_autobind(struct sock *sk)
173 {
174 	struct inet_sock *inet;
175 	/* We may need to bind the socket. */
176 	lock_sock(sk);
177 	inet = inet_sk(sk);
178 	if (!inet->inet_num) {
179 		if (sk->sk_prot->get_port(sk, 0)) {
180 			release_sock(sk);
181 			return -EAGAIN;
182 		}
183 		inet->inet_sport = htons(inet->inet_num);
184 	}
185 	release_sock(sk);
186 	return 0;
187 }
188 
189 /*
190  *	Move a socket into listening state.
191  */
192 int inet_listen(struct socket *sock, int backlog)
193 {
194 	struct sock *sk = sock->sk;
195 	unsigned char old_state;
196 	int err;
197 
198 	lock_sock(sk);
199 
200 	err = -EINVAL;
201 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
202 		goto out;
203 
204 	old_state = sk->sk_state;
205 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
206 		goto out;
207 
208 	/* Really, if the socket is already in listen state
209 	 * we can only allow the backlog to be adjusted.
210 	 */
211 	if (old_state != TCP_LISTEN) {
212 		/* Check special setups for testing purpose to enable TFO w/o
213 		 * requiring TCP_FASTOPEN sockopt.
214 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
215 		 * Also fastopenq may already been allocated because this
216 		 * socket was in TCP_LISTEN state previously but was
217 		 * shutdown() (rather than close()).
218 		 */
219 		if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) != 0 &&
220 		    inet_csk(sk)->icsk_accept_queue.fastopenq == NULL) {
221 			if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) != 0)
222 				err = fastopen_init_queue(sk, backlog);
223 			else if ((sysctl_tcp_fastopen &
224 				  TFO_SERVER_WO_SOCKOPT2) != 0)
225 				err = fastopen_init_queue(sk,
226 				    ((uint)sysctl_tcp_fastopen) >> 16);
227 			else
228 				err = 0;
229 			if (err)
230 				goto out;
231 		}
232 		err = inet_csk_listen_start(sk, backlog);
233 		if (err)
234 			goto out;
235 	}
236 	sk->sk_max_ack_backlog = backlog;
237 	err = 0;
238 
239 out:
240 	release_sock(sk);
241 	return err;
242 }
243 EXPORT_SYMBOL(inet_listen);
244 
245 /*
246  *	Create an inet socket.
247  */
248 
249 static int inet_create(struct net *net, struct socket *sock, int protocol,
250 		       int kern)
251 {
252 	struct sock *sk;
253 	struct inet_protosw *answer;
254 	struct inet_sock *inet;
255 	struct proto *answer_prot;
256 	unsigned char answer_flags;
257 	int try_loading_module = 0;
258 	int err;
259 
260 	sock->state = SS_UNCONNECTED;
261 
262 	/* Look for the requested type/protocol pair. */
263 lookup_protocol:
264 	err = -ESOCKTNOSUPPORT;
265 	rcu_read_lock();
266 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
267 
268 		err = 0;
269 		/* Check the non-wild match. */
270 		if (protocol == answer->protocol) {
271 			if (protocol != IPPROTO_IP)
272 				break;
273 		} else {
274 			/* Check for the two wild cases. */
275 			if (IPPROTO_IP == protocol) {
276 				protocol = answer->protocol;
277 				break;
278 			}
279 			if (IPPROTO_IP == answer->protocol)
280 				break;
281 		}
282 		err = -EPROTONOSUPPORT;
283 	}
284 
285 	if (unlikely(err)) {
286 		if (try_loading_module < 2) {
287 			rcu_read_unlock();
288 			/*
289 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
290 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
291 			 */
292 			if (++try_loading_module == 1)
293 				request_module("net-pf-%d-proto-%d-type-%d",
294 					       PF_INET, protocol, sock->type);
295 			/*
296 			 * Fall back to generic, e.g. net-pf-2-proto-132
297 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
298 			 */
299 			else
300 				request_module("net-pf-%d-proto-%d",
301 					       PF_INET, protocol);
302 			goto lookup_protocol;
303 		} else
304 			goto out_rcu_unlock;
305 	}
306 
307 	err = -EPERM;
308 	if (sock->type == SOCK_RAW && !kern &&
309 	    !ns_capable(net->user_ns, CAP_NET_RAW))
310 		goto out_rcu_unlock;
311 
312 	sock->ops = answer->ops;
313 	answer_prot = answer->prot;
314 	answer_flags = answer->flags;
315 	rcu_read_unlock();
316 
317 	WARN_ON(answer_prot->slab == NULL);
318 
319 	err = -ENOBUFS;
320 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
321 	if (sk == NULL)
322 		goto out;
323 
324 	err = 0;
325 	if (INET_PROTOSW_REUSE & answer_flags)
326 		sk->sk_reuse = SK_CAN_REUSE;
327 
328 	inet = inet_sk(sk);
329 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
330 
331 	inet->nodefrag = 0;
332 
333 	if (SOCK_RAW == sock->type) {
334 		inet->inet_num = protocol;
335 		if (IPPROTO_RAW == protocol)
336 			inet->hdrincl = 1;
337 	}
338 
339 	if (net->ipv4.sysctl_ip_no_pmtu_disc)
340 		inet->pmtudisc = IP_PMTUDISC_DONT;
341 	else
342 		inet->pmtudisc = IP_PMTUDISC_WANT;
343 
344 	inet->inet_id = 0;
345 
346 	sock_init_data(sock, sk);
347 
348 	sk->sk_destruct	   = inet_sock_destruct;
349 	sk->sk_protocol	   = protocol;
350 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
351 
352 	inet->uc_ttl	= -1;
353 	inet->mc_loop	= 1;
354 	inet->mc_ttl	= 1;
355 	inet->mc_all	= 1;
356 	inet->mc_index	= 0;
357 	inet->mc_list	= NULL;
358 	inet->rcv_tos	= 0;
359 
360 	sk_refcnt_debug_inc(sk);
361 
362 	if (inet->inet_num) {
363 		/* It assumes that any protocol which allows
364 		 * the user to assign a number at socket
365 		 * creation time automatically
366 		 * shares.
367 		 */
368 		inet->inet_sport = htons(inet->inet_num);
369 		/* Add to protocol hash chains. */
370 		sk->sk_prot->hash(sk);
371 	}
372 
373 	if (sk->sk_prot->init) {
374 		err = sk->sk_prot->init(sk);
375 		if (err)
376 			sk_common_release(sk);
377 	}
378 out:
379 	return err;
380 out_rcu_unlock:
381 	rcu_read_unlock();
382 	goto out;
383 }
384 
385 
386 /*
387  *	The peer socket should always be NULL (or else). When we call this
388  *	function we are destroying the object and from then on nobody
389  *	should refer to it.
390  */
391 int inet_release(struct socket *sock)
392 {
393 	struct sock *sk = sock->sk;
394 
395 	if (sk) {
396 		long timeout;
397 
398 		sock_rps_reset_flow(sk);
399 
400 		/* Applications forget to leave groups before exiting */
401 		ip_mc_drop_socket(sk);
402 
403 		/* If linger is set, we don't return until the close
404 		 * is complete.  Otherwise we return immediately. The
405 		 * actually closing is done the same either way.
406 		 *
407 		 * If the close is due to the process exiting, we never
408 		 * linger..
409 		 */
410 		timeout = 0;
411 		if (sock_flag(sk, SOCK_LINGER) &&
412 		    !(current->flags & PF_EXITING))
413 			timeout = sk->sk_lingertime;
414 		sock->sk = NULL;
415 		sk->sk_prot->close(sk, timeout);
416 	}
417 	return 0;
418 }
419 EXPORT_SYMBOL(inet_release);
420 
421 /* It is off by default, see below. */
422 int sysctl_ip_nonlocal_bind __read_mostly;
423 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
424 
425 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
426 {
427 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
428 	struct sock *sk = sock->sk;
429 	struct inet_sock *inet = inet_sk(sk);
430 	struct net *net = sock_net(sk);
431 	unsigned short snum;
432 	int chk_addr_ret;
433 	int err;
434 
435 	/* If the socket has its own bind function then use it. (RAW) */
436 	if (sk->sk_prot->bind) {
437 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
438 		goto out;
439 	}
440 	err = -EINVAL;
441 	if (addr_len < sizeof(struct sockaddr_in))
442 		goto out;
443 
444 	if (addr->sin_family != AF_INET) {
445 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
446 		 * only if s_addr is INADDR_ANY.
447 		 */
448 		err = -EAFNOSUPPORT;
449 		if (addr->sin_family != AF_UNSPEC ||
450 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
451 			goto out;
452 	}
453 
454 	chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
455 
456 	/* Not specified by any standard per-se, however it breaks too
457 	 * many applications when removed.  It is unfortunate since
458 	 * allowing applications to make a non-local bind solves
459 	 * several problems with systems using dynamic addressing.
460 	 * (ie. your servers still start up even if your ISDN link
461 	 *  is temporarily down)
462 	 */
463 	err = -EADDRNOTAVAIL;
464 	if (!sysctl_ip_nonlocal_bind &&
465 	    !(inet->freebind || inet->transparent) &&
466 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
467 	    chk_addr_ret != RTN_LOCAL &&
468 	    chk_addr_ret != RTN_MULTICAST &&
469 	    chk_addr_ret != RTN_BROADCAST)
470 		goto out;
471 
472 	snum = ntohs(addr->sin_port);
473 	err = -EACCES;
474 	if (snum && snum < PROT_SOCK &&
475 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
476 		goto out;
477 
478 	/*      We keep a pair of addresses. rcv_saddr is the one
479 	 *      used by hash lookups, and saddr is used for transmit.
480 	 *
481 	 *      In the BSD API these are the same except where it
482 	 *      would be illegal to use them (multicast/broadcast) in
483 	 *      which case the sending device address is used.
484 	 */
485 	lock_sock(sk);
486 
487 	/* Check these errors (active socket, double bind). */
488 	err = -EINVAL;
489 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
490 		goto out_release_sock;
491 
492 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
493 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
494 		inet->inet_saddr = 0;  /* Use device */
495 
496 	/* Make sure we are allowed to bind here. */
497 	if (sk->sk_prot->get_port(sk, snum)) {
498 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
499 		err = -EADDRINUSE;
500 		goto out_release_sock;
501 	}
502 
503 	if (inet->inet_rcv_saddr)
504 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
505 	if (snum)
506 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
507 	inet->inet_sport = htons(inet->inet_num);
508 	inet->inet_daddr = 0;
509 	inet->inet_dport = 0;
510 	sk_dst_reset(sk);
511 	err = 0;
512 out_release_sock:
513 	release_sock(sk);
514 out:
515 	return err;
516 }
517 EXPORT_SYMBOL(inet_bind);
518 
519 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
520 		       int addr_len, int flags)
521 {
522 	struct sock *sk = sock->sk;
523 
524 	if (addr_len < sizeof(uaddr->sa_family))
525 		return -EINVAL;
526 	if (uaddr->sa_family == AF_UNSPEC)
527 		return sk->sk_prot->disconnect(sk, flags);
528 
529 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
530 		return -EAGAIN;
531 	return sk->sk_prot->connect(sk, uaddr, addr_len);
532 }
533 EXPORT_SYMBOL(inet_dgram_connect);
534 
535 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
536 {
537 	DEFINE_WAIT(wait);
538 
539 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
540 	sk->sk_write_pending += writebias;
541 
542 	/* Basic assumption: if someone sets sk->sk_err, he _must_
543 	 * change state of the socket from TCP_SYN_*.
544 	 * Connect() does not allow to get error notifications
545 	 * without closing the socket.
546 	 */
547 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
548 		release_sock(sk);
549 		timeo = schedule_timeout(timeo);
550 		lock_sock(sk);
551 		if (signal_pending(current) || !timeo)
552 			break;
553 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
554 	}
555 	finish_wait(sk_sleep(sk), &wait);
556 	sk->sk_write_pending -= writebias;
557 	return timeo;
558 }
559 
560 /*
561  *	Connect to a remote host. There is regrettably still a little
562  *	TCP 'magic' in here.
563  */
564 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
565 			  int addr_len, int flags)
566 {
567 	struct sock *sk = sock->sk;
568 	int err;
569 	long timeo;
570 
571 	if (addr_len < sizeof(uaddr->sa_family))
572 		return -EINVAL;
573 
574 	if (uaddr->sa_family == AF_UNSPEC) {
575 		err = sk->sk_prot->disconnect(sk, flags);
576 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
577 		goto out;
578 	}
579 
580 	switch (sock->state) {
581 	default:
582 		err = -EINVAL;
583 		goto out;
584 	case SS_CONNECTED:
585 		err = -EISCONN;
586 		goto out;
587 	case SS_CONNECTING:
588 		err = -EALREADY;
589 		/* Fall out of switch with err, set for this state */
590 		break;
591 	case SS_UNCONNECTED:
592 		err = -EISCONN;
593 		if (sk->sk_state != TCP_CLOSE)
594 			goto out;
595 
596 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
597 		if (err < 0)
598 			goto out;
599 
600 		sock->state = SS_CONNECTING;
601 
602 		/* Just entered SS_CONNECTING state; the only
603 		 * difference is that return value in non-blocking
604 		 * case is EINPROGRESS, rather than EALREADY.
605 		 */
606 		err = -EINPROGRESS;
607 		break;
608 	}
609 
610 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
611 
612 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
613 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
614 				tcp_sk(sk)->fastopen_req &&
615 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
616 
617 		/* Error code is set above */
618 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
619 			goto out;
620 
621 		err = sock_intr_errno(timeo);
622 		if (signal_pending(current))
623 			goto out;
624 	}
625 
626 	/* Connection was closed by RST, timeout, ICMP error
627 	 * or another process disconnected us.
628 	 */
629 	if (sk->sk_state == TCP_CLOSE)
630 		goto sock_error;
631 
632 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
633 	 * and error was received after socket entered established state.
634 	 * Hence, it is handled normally after connect() return successfully.
635 	 */
636 
637 	sock->state = SS_CONNECTED;
638 	err = 0;
639 out:
640 	return err;
641 
642 sock_error:
643 	err = sock_error(sk) ? : -ECONNABORTED;
644 	sock->state = SS_UNCONNECTED;
645 	if (sk->sk_prot->disconnect(sk, flags))
646 		sock->state = SS_DISCONNECTING;
647 	goto out;
648 }
649 EXPORT_SYMBOL(__inet_stream_connect);
650 
651 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
652 			int addr_len, int flags)
653 {
654 	int err;
655 
656 	lock_sock(sock->sk);
657 	err = __inet_stream_connect(sock, uaddr, addr_len, flags);
658 	release_sock(sock->sk);
659 	return err;
660 }
661 EXPORT_SYMBOL(inet_stream_connect);
662 
663 /*
664  *	Accept a pending connection. The TCP layer now gives BSD semantics.
665  */
666 
667 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
668 {
669 	struct sock *sk1 = sock->sk;
670 	int err = -EINVAL;
671 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
672 
673 	if (!sk2)
674 		goto do_err;
675 
676 	lock_sock(sk2);
677 
678 	sock_rps_record_flow(sk2);
679 	WARN_ON(!((1 << sk2->sk_state) &
680 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
681 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
682 
683 	sock_graft(sk2, newsock);
684 
685 	newsock->state = SS_CONNECTED;
686 	err = 0;
687 	release_sock(sk2);
688 do_err:
689 	return err;
690 }
691 EXPORT_SYMBOL(inet_accept);
692 
693 
694 /*
695  *	This does both peername and sockname.
696  */
697 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
698 			int *uaddr_len, int peer)
699 {
700 	struct sock *sk		= sock->sk;
701 	struct inet_sock *inet	= inet_sk(sk);
702 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
703 
704 	sin->sin_family = AF_INET;
705 	if (peer) {
706 		if (!inet->inet_dport ||
707 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
708 		     peer == 1))
709 			return -ENOTCONN;
710 		sin->sin_port = inet->inet_dport;
711 		sin->sin_addr.s_addr = inet->inet_daddr;
712 	} else {
713 		__be32 addr = inet->inet_rcv_saddr;
714 		if (!addr)
715 			addr = inet->inet_saddr;
716 		sin->sin_port = inet->inet_sport;
717 		sin->sin_addr.s_addr = addr;
718 	}
719 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
720 	*uaddr_len = sizeof(*sin);
721 	return 0;
722 }
723 EXPORT_SYMBOL(inet_getname);
724 
725 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
726 		 size_t size)
727 {
728 	struct sock *sk = sock->sk;
729 
730 	sock_rps_record_flow(sk);
731 
732 	/* We may need to bind the socket. */
733 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
734 	    inet_autobind(sk))
735 		return -EAGAIN;
736 
737 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
738 }
739 EXPORT_SYMBOL(inet_sendmsg);
740 
741 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
742 		      size_t size, int flags)
743 {
744 	struct sock *sk = sock->sk;
745 
746 	sock_rps_record_flow(sk);
747 
748 	/* We may need to bind the socket. */
749 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
750 	    inet_autobind(sk))
751 		return -EAGAIN;
752 
753 	if (sk->sk_prot->sendpage)
754 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
755 	return sock_no_sendpage(sock, page, offset, size, flags);
756 }
757 EXPORT_SYMBOL(inet_sendpage);
758 
759 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
760 		 size_t size, int flags)
761 {
762 	struct sock *sk = sock->sk;
763 	int addr_len = 0;
764 	int err;
765 
766 	sock_rps_record_flow(sk);
767 
768 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
769 				   flags & ~MSG_DONTWAIT, &addr_len);
770 	if (err >= 0)
771 		msg->msg_namelen = addr_len;
772 	return err;
773 }
774 EXPORT_SYMBOL(inet_recvmsg);
775 
776 int inet_shutdown(struct socket *sock, int how)
777 {
778 	struct sock *sk = sock->sk;
779 	int err = 0;
780 
781 	/* This should really check to make sure
782 	 * the socket is a TCP socket. (WHY AC...)
783 	 */
784 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
785 		       1->2 bit 2 snds.
786 		       2->3 */
787 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
788 		return -EINVAL;
789 
790 	lock_sock(sk);
791 	if (sock->state == SS_CONNECTING) {
792 		if ((1 << sk->sk_state) &
793 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
794 			sock->state = SS_DISCONNECTING;
795 		else
796 			sock->state = SS_CONNECTED;
797 	}
798 
799 	switch (sk->sk_state) {
800 	case TCP_CLOSE:
801 		err = -ENOTCONN;
802 		/* Hack to wake up other listeners, who can poll for
803 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
804 	default:
805 		sk->sk_shutdown |= how;
806 		if (sk->sk_prot->shutdown)
807 			sk->sk_prot->shutdown(sk, how);
808 		break;
809 
810 	/* Remaining two branches are temporary solution for missing
811 	 * close() in multithreaded environment. It is _not_ a good idea,
812 	 * but we have no choice until close() is repaired at VFS level.
813 	 */
814 	case TCP_LISTEN:
815 		if (!(how & RCV_SHUTDOWN))
816 			break;
817 		/* Fall through */
818 	case TCP_SYN_SENT:
819 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
820 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
821 		break;
822 	}
823 
824 	/* Wake up anyone sleeping in poll. */
825 	sk->sk_state_change(sk);
826 	release_sock(sk);
827 	return err;
828 }
829 EXPORT_SYMBOL(inet_shutdown);
830 
831 /*
832  *	ioctl() calls you can issue on an INET socket. Most of these are
833  *	device configuration and stuff and very rarely used. Some ioctls
834  *	pass on to the socket itself.
835  *
836  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
837  *	loads the devconfigure module does its configuring and unloads it.
838  *	There's a good 20K of config code hanging around the kernel.
839  */
840 
841 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
842 {
843 	struct sock *sk = sock->sk;
844 	int err = 0;
845 	struct net *net = sock_net(sk);
846 
847 	switch (cmd) {
848 	case SIOCGSTAMP:
849 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
850 		break;
851 	case SIOCGSTAMPNS:
852 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
853 		break;
854 	case SIOCADDRT:
855 	case SIOCDELRT:
856 	case SIOCRTMSG:
857 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
858 		break;
859 	case SIOCDARP:
860 	case SIOCGARP:
861 	case SIOCSARP:
862 		err = arp_ioctl(net, cmd, (void __user *)arg);
863 		break;
864 	case SIOCGIFADDR:
865 	case SIOCSIFADDR:
866 	case SIOCGIFBRDADDR:
867 	case SIOCSIFBRDADDR:
868 	case SIOCGIFNETMASK:
869 	case SIOCSIFNETMASK:
870 	case SIOCGIFDSTADDR:
871 	case SIOCSIFDSTADDR:
872 	case SIOCSIFPFLAGS:
873 	case SIOCGIFPFLAGS:
874 	case SIOCSIFFLAGS:
875 		err = devinet_ioctl(net, cmd, (void __user *)arg);
876 		break;
877 	default:
878 		if (sk->sk_prot->ioctl)
879 			err = sk->sk_prot->ioctl(sk, cmd, arg);
880 		else
881 			err = -ENOIOCTLCMD;
882 		break;
883 	}
884 	return err;
885 }
886 EXPORT_SYMBOL(inet_ioctl);
887 
888 #ifdef CONFIG_COMPAT
889 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
890 {
891 	struct sock *sk = sock->sk;
892 	int err = -ENOIOCTLCMD;
893 
894 	if (sk->sk_prot->compat_ioctl)
895 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
896 
897 	return err;
898 }
899 #endif
900 
901 const struct proto_ops inet_stream_ops = {
902 	.family		   = PF_INET,
903 	.owner		   = THIS_MODULE,
904 	.release	   = inet_release,
905 	.bind		   = inet_bind,
906 	.connect	   = inet_stream_connect,
907 	.socketpair	   = sock_no_socketpair,
908 	.accept		   = inet_accept,
909 	.getname	   = inet_getname,
910 	.poll		   = tcp_poll,
911 	.ioctl		   = inet_ioctl,
912 	.listen		   = inet_listen,
913 	.shutdown	   = inet_shutdown,
914 	.setsockopt	   = sock_common_setsockopt,
915 	.getsockopt	   = sock_common_getsockopt,
916 	.sendmsg	   = inet_sendmsg,
917 	.recvmsg	   = inet_recvmsg,
918 	.mmap		   = sock_no_mmap,
919 	.sendpage	   = inet_sendpage,
920 	.splice_read	   = tcp_splice_read,
921 #ifdef CONFIG_COMPAT
922 	.compat_setsockopt = compat_sock_common_setsockopt,
923 	.compat_getsockopt = compat_sock_common_getsockopt,
924 	.compat_ioctl	   = inet_compat_ioctl,
925 #endif
926 };
927 EXPORT_SYMBOL(inet_stream_ops);
928 
929 const struct proto_ops inet_dgram_ops = {
930 	.family		   = PF_INET,
931 	.owner		   = THIS_MODULE,
932 	.release	   = inet_release,
933 	.bind		   = inet_bind,
934 	.connect	   = inet_dgram_connect,
935 	.socketpair	   = sock_no_socketpair,
936 	.accept		   = sock_no_accept,
937 	.getname	   = inet_getname,
938 	.poll		   = udp_poll,
939 	.ioctl		   = inet_ioctl,
940 	.listen		   = sock_no_listen,
941 	.shutdown	   = inet_shutdown,
942 	.setsockopt	   = sock_common_setsockopt,
943 	.getsockopt	   = sock_common_getsockopt,
944 	.sendmsg	   = inet_sendmsg,
945 	.recvmsg	   = inet_recvmsg,
946 	.mmap		   = sock_no_mmap,
947 	.sendpage	   = inet_sendpage,
948 #ifdef CONFIG_COMPAT
949 	.compat_setsockopt = compat_sock_common_setsockopt,
950 	.compat_getsockopt = compat_sock_common_getsockopt,
951 	.compat_ioctl	   = inet_compat_ioctl,
952 #endif
953 };
954 EXPORT_SYMBOL(inet_dgram_ops);
955 
956 /*
957  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
958  * udp_poll
959  */
960 static const struct proto_ops inet_sockraw_ops = {
961 	.family		   = PF_INET,
962 	.owner		   = THIS_MODULE,
963 	.release	   = inet_release,
964 	.bind		   = inet_bind,
965 	.connect	   = inet_dgram_connect,
966 	.socketpair	   = sock_no_socketpair,
967 	.accept		   = sock_no_accept,
968 	.getname	   = inet_getname,
969 	.poll		   = datagram_poll,
970 	.ioctl		   = inet_ioctl,
971 	.listen		   = sock_no_listen,
972 	.shutdown	   = inet_shutdown,
973 	.setsockopt	   = sock_common_setsockopt,
974 	.getsockopt	   = sock_common_getsockopt,
975 	.sendmsg	   = inet_sendmsg,
976 	.recvmsg	   = inet_recvmsg,
977 	.mmap		   = sock_no_mmap,
978 	.sendpage	   = inet_sendpage,
979 #ifdef CONFIG_COMPAT
980 	.compat_setsockopt = compat_sock_common_setsockopt,
981 	.compat_getsockopt = compat_sock_common_getsockopt,
982 	.compat_ioctl	   = inet_compat_ioctl,
983 #endif
984 };
985 
986 static const struct net_proto_family inet_family_ops = {
987 	.family = PF_INET,
988 	.create = inet_create,
989 	.owner	= THIS_MODULE,
990 };
991 
992 /* Upon startup we insert all the elements in inetsw_array[] into
993  * the linked list inetsw.
994  */
995 static struct inet_protosw inetsw_array[] =
996 {
997 	{
998 		.type =       SOCK_STREAM,
999 		.protocol =   IPPROTO_TCP,
1000 		.prot =       &tcp_prot,
1001 		.ops =        &inet_stream_ops,
1002 		.flags =      INET_PROTOSW_PERMANENT |
1003 			      INET_PROTOSW_ICSK,
1004 	},
1005 
1006 	{
1007 		.type =       SOCK_DGRAM,
1008 		.protocol =   IPPROTO_UDP,
1009 		.prot =       &udp_prot,
1010 		.ops =        &inet_dgram_ops,
1011 		.flags =      INET_PROTOSW_PERMANENT,
1012        },
1013 
1014        {
1015 		.type =       SOCK_DGRAM,
1016 		.protocol =   IPPROTO_ICMP,
1017 		.prot =       &ping_prot,
1018 		.ops =        &inet_dgram_ops,
1019 		.flags =      INET_PROTOSW_REUSE,
1020        },
1021 
1022        {
1023 	       .type =       SOCK_RAW,
1024 	       .protocol =   IPPROTO_IP,	/* wild card */
1025 	       .prot =       &raw_prot,
1026 	       .ops =        &inet_sockraw_ops,
1027 	       .flags =      INET_PROTOSW_REUSE,
1028        }
1029 };
1030 
1031 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1032 
1033 void inet_register_protosw(struct inet_protosw *p)
1034 {
1035 	struct list_head *lh;
1036 	struct inet_protosw *answer;
1037 	int protocol = p->protocol;
1038 	struct list_head *last_perm;
1039 
1040 	spin_lock_bh(&inetsw_lock);
1041 
1042 	if (p->type >= SOCK_MAX)
1043 		goto out_illegal;
1044 
1045 	/* If we are trying to override a permanent protocol, bail. */
1046 	answer = NULL;
1047 	last_perm = &inetsw[p->type];
1048 	list_for_each(lh, &inetsw[p->type]) {
1049 		answer = list_entry(lh, struct inet_protosw, list);
1050 
1051 		/* Check only the non-wild match. */
1052 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1053 			if (protocol == answer->protocol)
1054 				break;
1055 			last_perm = lh;
1056 		}
1057 
1058 		answer = NULL;
1059 	}
1060 	if (answer)
1061 		goto out_permanent;
1062 
1063 	/* Add the new entry after the last permanent entry if any, so that
1064 	 * the new entry does not override a permanent entry when matched with
1065 	 * a wild-card protocol. But it is allowed to override any existing
1066 	 * non-permanent entry.  This means that when we remove this entry, the
1067 	 * system automatically returns to the old behavior.
1068 	 */
1069 	list_add_rcu(&p->list, last_perm);
1070 out:
1071 	spin_unlock_bh(&inetsw_lock);
1072 
1073 	return;
1074 
1075 out_permanent:
1076 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1077 	goto out;
1078 
1079 out_illegal:
1080 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1081 	       p->type);
1082 	goto out;
1083 }
1084 EXPORT_SYMBOL(inet_register_protosw);
1085 
1086 void inet_unregister_protosw(struct inet_protosw *p)
1087 {
1088 	if (INET_PROTOSW_PERMANENT & p->flags) {
1089 		pr_err("Attempt to unregister permanent protocol %d\n",
1090 		       p->protocol);
1091 	} else {
1092 		spin_lock_bh(&inetsw_lock);
1093 		list_del_rcu(&p->list);
1094 		spin_unlock_bh(&inetsw_lock);
1095 
1096 		synchronize_net();
1097 	}
1098 }
1099 EXPORT_SYMBOL(inet_unregister_protosw);
1100 
1101 /*
1102  *      Shall we try to damage output packets if routing dev changes?
1103  */
1104 
1105 int sysctl_ip_dynaddr __read_mostly;
1106 
1107 static int inet_sk_reselect_saddr(struct sock *sk)
1108 {
1109 	struct inet_sock *inet = inet_sk(sk);
1110 	__be32 old_saddr = inet->inet_saddr;
1111 	__be32 daddr = inet->inet_daddr;
1112 	struct flowi4 *fl4;
1113 	struct rtable *rt;
1114 	__be32 new_saddr;
1115 	struct ip_options_rcu *inet_opt;
1116 
1117 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1118 					     sock_owned_by_user(sk));
1119 	if (inet_opt && inet_opt->opt.srr)
1120 		daddr = inet_opt->opt.faddr;
1121 
1122 	/* Query new route. */
1123 	fl4 = &inet->cork.fl.u.ip4;
1124 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1125 			      sk->sk_bound_dev_if, sk->sk_protocol,
1126 			      inet->inet_sport, inet->inet_dport, sk);
1127 	if (IS_ERR(rt))
1128 		return PTR_ERR(rt);
1129 
1130 	sk_setup_caps(sk, &rt->dst);
1131 
1132 	new_saddr = fl4->saddr;
1133 
1134 	if (new_saddr == old_saddr)
1135 		return 0;
1136 
1137 	if (sysctl_ip_dynaddr > 1) {
1138 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1139 			__func__, &old_saddr, &new_saddr);
1140 	}
1141 
1142 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1143 
1144 	/*
1145 	 * XXX The only one ugly spot where we need to
1146 	 * XXX really change the sockets identity after
1147 	 * XXX it has entered the hashes. -DaveM
1148 	 *
1149 	 * Besides that, it does not check for connection
1150 	 * uniqueness. Wait for troubles.
1151 	 */
1152 	__sk_prot_rehash(sk);
1153 	return 0;
1154 }
1155 
1156 int inet_sk_rebuild_header(struct sock *sk)
1157 {
1158 	struct inet_sock *inet = inet_sk(sk);
1159 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1160 	__be32 daddr;
1161 	struct ip_options_rcu *inet_opt;
1162 	struct flowi4 *fl4;
1163 	int err;
1164 
1165 	/* Route is OK, nothing to do. */
1166 	if (rt)
1167 		return 0;
1168 
1169 	/* Reroute. */
1170 	rcu_read_lock();
1171 	inet_opt = rcu_dereference(inet->inet_opt);
1172 	daddr = inet->inet_daddr;
1173 	if (inet_opt && inet_opt->opt.srr)
1174 		daddr = inet_opt->opt.faddr;
1175 	rcu_read_unlock();
1176 	fl4 = &inet->cork.fl.u.ip4;
1177 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1178 				   inet->inet_dport, inet->inet_sport,
1179 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1180 				   sk->sk_bound_dev_if);
1181 	if (!IS_ERR(rt)) {
1182 		err = 0;
1183 		sk_setup_caps(sk, &rt->dst);
1184 	} else {
1185 		err = PTR_ERR(rt);
1186 
1187 		/* Routing failed... */
1188 		sk->sk_route_caps = 0;
1189 		/*
1190 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1191 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1192 		 */
1193 		if (!sysctl_ip_dynaddr ||
1194 		    sk->sk_state != TCP_SYN_SENT ||
1195 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1196 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1197 			sk->sk_err_soft = -err;
1198 	}
1199 
1200 	return err;
1201 }
1202 EXPORT_SYMBOL(inet_sk_rebuild_header);
1203 
1204 static int inet_gso_send_check(struct sk_buff *skb)
1205 {
1206 	const struct net_offload *ops;
1207 	const struct iphdr *iph;
1208 	int proto;
1209 	int ihl;
1210 	int err = -EINVAL;
1211 
1212 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1213 		goto out;
1214 
1215 	iph = ip_hdr(skb);
1216 	ihl = iph->ihl * 4;
1217 	if (ihl < sizeof(*iph))
1218 		goto out;
1219 
1220 	proto = iph->protocol;
1221 
1222 	/* Warning: after this point, iph might be no longer valid */
1223 	if (unlikely(!pskb_may_pull(skb, ihl)))
1224 		goto out;
1225 	__skb_pull(skb, ihl);
1226 
1227 	skb_reset_transport_header(skb);
1228 	err = -EPROTONOSUPPORT;
1229 
1230 	ops = rcu_dereference(inet_offloads[proto]);
1231 	if (likely(ops && ops->callbacks.gso_send_check))
1232 		err = ops->callbacks.gso_send_check(skb);
1233 
1234 out:
1235 	return err;
1236 }
1237 
1238 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1239 					netdev_features_t features)
1240 {
1241 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1242 	const struct net_offload *ops;
1243 	unsigned int offset = 0;
1244 	bool udpfrag, encap;
1245 	struct iphdr *iph;
1246 	int proto;
1247 	int nhoff;
1248 	int ihl;
1249 	int id;
1250 
1251 	if (unlikely(skb_shinfo(skb)->gso_type &
1252 		     ~(SKB_GSO_TCPV4 |
1253 		       SKB_GSO_UDP |
1254 		       SKB_GSO_DODGY |
1255 		       SKB_GSO_TCP_ECN |
1256 		       SKB_GSO_GRE |
1257 		       SKB_GSO_GRE_CSUM |
1258 		       SKB_GSO_IPIP |
1259 		       SKB_GSO_SIT |
1260 		       SKB_GSO_TCPV6 |
1261 		       SKB_GSO_UDP_TUNNEL |
1262 		       SKB_GSO_UDP_TUNNEL_CSUM |
1263 		       SKB_GSO_MPLS |
1264 		       0)))
1265 		goto out;
1266 
1267 	skb_reset_network_header(skb);
1268 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1269 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1270 		goto out;
1271 
1272 	iph = ip_hdr(skb);
1273 	ihl = iph->ihl * 4;
1274 	if (ihl < sizeof(*iph))
1275 		goto out;
1276 
1277 	id = ntohs(iph->id);
1278 	proto = iph->protocol;
1279 
1280 	/* Warning: after this point, iph might be no longer valid */
1281 	if (unlikely(!pskb_may_pull(skb, ihl)))
1282 		goto out;
1283 	__skb_pull(skb, ihl);
1284 
1285 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1286 	if (encap)
1287 		features = skb->dev->hw_enc_features & netif_skb_features(skb);
1288 	SKB_GSO_CB(skb)->encap_level += ihl;
1289 
1290 	skb_reset_transport_header(skb);
1291 
1292 	segs = ERR_PTR(-EPROTONOSUPPORT);
1293 
1294 	if (skb->encapsulation &&
1295 	    skb_shinfo(skb)->gso_type & (SKB_GSO_SIT|SKB_GSO_IPIP))
1296 		udpfrag = proto == IPPROTO_UDP && encap;
1297 	else
1298 		udpfrag = proto == IPPROTO_UDP && !skb->encapsulation;
1299 
1300 	ops = rcu_dereference(inet_offloads[proto]);
1301 	if (likely(ops && ops->callbacks.gso_segment))
1302 		segs = ops->callbacks.gso_segment(skb, features);
1303 
1304 	if (IS_ERR_OR_NULL(segs))
1305 		goto out;
1306 
1307 	skb = segs;
1308 	do {
1309 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1310 		if (udpfrag) {
1311 			iph->id = htons(id);
1312 			iph->frag_off = htons(offset >> 3);
1313 			if (skb->next != NULL)
1314 				iph->frag_off |= htons(IP_MF);
1315 			offset += skb->len - nhoff - ihl;
1316 		} else {
1317 			iph->id = htons(id++);
1318 		}
1319 		iph->tot_len = htons(skb->len - nhoff);
1320 		ip_send_check(iph);
1321 		if (encap)
1322 			skb_reset_inner_headers(skb);
1323 		skb->network_header = (u8 *)iph - skb->head;
1324 	} while ((skb = skb->next));
1325 
1326 out:
1327 	return segs;
1328 }
1329 
1330 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1331 					 struct sk_buff *skb)
1332 {
1333 	const struct net_offload *ops;
1334 	struct sk_buff **pp = NULL;
1335 	struct sk_buff *p;
1336 	const struct iphdr *iph;
1337 	unsigned int hlen;
1338 	unsigned int off;
1339 	unsigned int id;
1340 	int flush = 1;
1341 	int proto;
1342 
1343 	off = skb_gro_offset(skb);
1344 	hlen = off + sizeof(*iph);
1345 	iph = skb_gro_header_fast(skb, off);
1346 	if (skb_gro_header_hard(skb, hlen)) {
1347 		iph = skb_gro_header_slow(skb, hlen, off);
1348 		if (unlikely(!iph))
1349 			goto out;
1350 	}
1351 
1352 	proto = iph->protocol;
1353 
1354 	rcu_read_lock();
1355 	ops = rcu_dereference(inet_offloads[proto]);
1356 	if (!ops || !ops->callbacks.gro_receive)
1357 		goto out_unlock;
1358 
1359 	if (*(u8 *)iph != 0x45)
1360 		goto out_unlock;
1361 
1362 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1363 		goto out_unlock;
1364 
1365 	id = ntohl(*(__be32 *)&iph->id);
1366 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1367 	id >>= 16;
1368 
1369 	for (p = *head; p; p = p->next) {
1370 		struct iphdr *iph2;
1371 
1372 		if (!NAPI_GRO_CB(p)->same_flow)
1373 			continue;
1374 
1375 		iph2 = (struct iphdr *)(p->data + off);
1376 		/* The above works because, with the exception of the top
1377 		 * (inner most) layer, we only aggregate pkts with the same
1378 		 * hdr length so all the hdrs we'll need to verify will start
1379 		 * at the same offset.
1380 		 */
1381 		if ((iph->protocol ^ iph2->protocol) |
1382 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1383 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1384 			NAPI_GRO_CB(p)->same_flow = 0;
1385 			continue;
1386 		}
1387 
1388 		/* All fields must match except length and checksum. */
1389 		NAPI_GRO_CB(p)->flush |=
1390 			(iph->ttl ^ iph2->ttl) |
1391 			(iph->tos ^ iph2->tos) |
1392 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1393 
1394 		/* Save the IP ID check to be included later when we get to
1395 		 * the transport layer so only the inner most IP ID is checked.
1396 		 * This is because some GSO/TSO implementations do not
1397 		 * correctly increment the IP ID for the outer hdrs.
1398 		 */
1399 		NAPI_GRO_CB(p)->flush_id =
1400 			    ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1401 		NAPI_GRO_CB(p)->flush |= flush;
1402 	}
1403 
1404 	NAPI_GRO_CB(skb)->flush |= flush;
1405 	skb_set_network_header(skb, off);
1406 	/* The above will be needed by the transport layer if there is one
1407 	 * immediately following this IP hdr.
1408 	 */
1409 
1410 	skb_gro_pull(skb, sizeof(*iph));
1411 	skb_set_transport_header(skb, skb_gro_offset(skb));
1412 
1413 	pp = ops->callbacks.gro_receive(head, skb);
1414 
1415 out_unlock:
1416 	rcu_read_unlock();
1417 
1418 out:
1419 	NAPI_GRO_CB(skb)->flush |= flush;
1420 
1421 	return pp;
1422 }
1423 
1424 static int inet_gro_complete(struct sk_buff *skb, int nhoff)
1425 {
1426 	__be16 newlen = htons(skb->len - nhoff);
1427 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1428 	const struct net_offload *ops;
1429 	int proto = iph->protocol;
1430 	int err = -ENOSYS;
1431 
1432 	csum_replace2(&iph->check, iph->tot_len, newlen);
1433 	iph->tot_len = newlen;
1434 
1435 	rcu_read_lock();
1436 	ops = rcu_dereference(inet_offloads[proto]);
1437 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1438 		goto out_unlock;
1439 
1440 	/* Only need to add sizeof(*iph) to get to the next hdr below
1441 	 * because any hdr with option will have been flushed in
1442 	 * inet_gro_receive().
1443 	 */
1444 	err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1445 
1446 out_unlock:
1447 	rcu_read_unlock();
1448 
1449 	return err;
1450 }
1451 
1452 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1453 			 unsigned short type, unsigned char protocol,
1454 			 struct net *net)
1455 {
1456 	struct socket *sock;
1457 	int rc = sock_create_kern(family, type, protocol, &sock);
1458 
1459 	if (rc == 0) {
1460 		*sk = sock->sk;
1461 		(*sk)->sk_allocation = GFP_ATOMIC;
1462 		/*
1463 		 * Unhash it so that IP input processing does not even see it,
1464 		 * we do not wish this socket to see incoming packets.
1465 		 */
1466 		(*sk)->sk_prot->unhash(*sk);
1467 
1468 		sk_change_net(*sk, net);
1469 	}
1470 	return rc;
1471 }
1472 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1473 
1474 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1475 {
1476 	unsigned long res = 0;
1477 	int i;
1478 
1479 	for_each_possible_cpu(i)
1480 		res += *(((unsigned long *) per_cpu_ptr(mib, i)) + offt);
1481 	return res;
1482 }
1483 EXPORT_SYMBOL_GPL(snmp_fold_field);
1484 
1485 #if BITS_PER_LONG==32
1486 
1487 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1488 {
1489 	u64 res = 0;
1490 	int cpu;
1491 
1492 	for_each_possible_cpu(cpu) {
1493 		void *bhptr;
1494 		struct u64_stats_sync *syncp;
1495 		u64 v;
1496 		unsigned int start;
1497 
1498 		bhptr = per_cpu_ptr(mib, cpu);
1499 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1500 		do {
1501 			start = u64_stats_fetch_begin_irq(syncp);
1502 			v = *(((u64 *) bhptr) + offt);
1503 		} while (u64_stats_fetch_retry_irq(syncp, start));
1504 
1505 		res += v;
1506 	}
1507 	return res;
1508 }
1509 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1510 #endif
1511 
1512 #ifdef CONFIG_IP_MULTICAST
1513 static const struct net_protocol igmp_protocol = {
1514 	.handler =	igmp_rcv,
1515 	.netns_ok =	1,
1516 };
1517 #endif
1518 
1519 static const struct net_protocol tcp_protocol = {
1520 	.early_demux	=	tcp_v4_early_demux,
1521 	.handler	=	tcp_v4_rcv,
1522 	.err_handler	=	tcp_v4_err,
1523 	.no_policy	=	1,
1524 	.netns_ok	=	1,
1525 	.icmp_strict_tag_validation = 1,
1526 };
1527 
1528 static const struct net_protocol udp_protocol = {
1529 	.early_demux =	udp_v4_early_demux,
1530 	.handler =	udp_rcv,
1531 	.err_handler =	udp_err,
1532 	.no_policy =	1,
1533 	.netns_ok =	1,
1534 };
1535 
1536 static const struct net_protocol icmp_protocol = {
1537 	.handler =	icmp_rcv,
1538 	.err_handler =	icmp_err,
1539 	.no_policy =	1,
1540 	.netns_ok =	1,
1541 };
1542 
1543 static __net_init int ipv4_mib_init_net(struct net *net)
1544 {
1545 	int i;
1546 
1547 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1548 	if (!net->mib.tcp_statistics)
1549 		goto err_tcp_mib;
1550 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1551 	if (!net->mib.ip_statistics)
1552 		goto err_ip_mib;
1553 
1554 	for_each_possible_cpu(i) {
1555 		struct ipstats_mib *af_inet_stats;
1556 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1557 		u64_stats_init(&af_inet_stats->syncp);
1558 	}
1559 
1560 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1561 	if (!net->mib.net_statistics)
1562 		goto err_net_mib;
1563 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1564 	if (!net->mib.udp_statistics)
1565 		goto err_udp_mib;
1566 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1567 	if (!net->mib.udplite_statistics)
1568 		goto err_udplite_mib;
1569 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1570 	if (!net->mib.icmp_statistics)
1571 		goto err_icmp_mib;
1572 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1573 					      GFP_KERNEL);
1574 	if (!net->mib.icmpmsg_statistics)
1575 		goto err_icmpmsg_mib;
1576 
1577 	tcp_mib_init(net);
1578 	return 0;
1579 
1580 err_icmpmsg_mib:
1581 	free_percpu(net->mib.icmp_statistics);
1582 err_icmp_mib:
1583 	free_percpu(net->mib.udplite_statistics);
1584 err_udplite_mib:
1585 	free_percpu(net->mib.udp_statistics);
1586 err_udp_mib:
1587 	free_percpu(net->mib.net_statistics);
1588 err_net_mib:
1589 	free_percpu(net->mib.ip_statistics);
1590 err_ip_mib:
1591 	free_percpu(net->mib.tcp_statistics);
1592 err_tcp_mib:
1593 	return -ENOMEM;
1594 }
1595 
1596 static __net_exit void ipv4_mib_exit_net(struct net *net)
1597 {
1598 	kfree(net->mib.icmpmsg_statistics);
1599 	free_percpu(net->mib.icmp_statistics);
1600 	free_percpu(net->mib.udplite_statistics);
1601 	free_percpu(net->mib.udp_statistics);
1602 	free_percpu(net->mib.net_statistics);
1603 	free_percpu(net->mib.ip_statistics);
1604 	free_percpu(net->mib.tcp_statistics);
1605 }
1606 
1607 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1608 	.init = ipv4_mib_init_net,
1609 	.exit = ipv4_mib_exit_net,
1610 };
1611 
1612 static int __init init_ipv4_mibs(void)
1613 {
1614 	return register_pernet_subsys(&ipv4_mib_ops);
1615 }
1616 
1617 static __net_init int inet_init_net(struct net *net)
1618 {
1619 	/*
1620 	 * Set defaults for local port range
1621 	 */
1622 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1623 	net->ipv4.ip_local_ports.range[0] =  32768;
1624 	net->ipv4.ip_local_ports.range[1] =  61000;
1625 
1626 	seqlock_init(&net->ipv4.ping_group_range.lock);
1627 	/*
1628 	 * Sane defaults - nobody may create ping sockets.
1629 	 * Boot scripts should set this to distro-specific group.
1630 	 */
1631 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1632 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1633 	return 0;
1634 }
1635 
1636 static __net_exit void inet_exit_net(struct net *net)
1637 {
1638 }
1639 
1640 static __net_initdata struct pernet_operations af_inet_ops = {
1641 	.init = inet_init_net,
1642 	.exit = inet_exit_net,
1643 };
1644 
1645 static int __init init_inet_pernet_ops(void)
1646 {
1647 	return register_pernet_subsys(&af_inet_ops);
1648 }
1649 
1650 static int ipv4_proc_init(void);
1651 
1652 /*
1653  *	IP protocol layer initialiser
1654  */
1655 
1656 static struct packet_offload ip_packet_offload __read_mostly = {
1657 	.type = cpu_to_be16(ETH_P_IP),
1658 	.callbacks = {
1659 		.gso_send_check = inet_gso_send_check,
1660 		.gso_segment = inet_gso_segment,
1661 		.gro_receive = inet_gro_receive,
1662 		.gro_complete = inet_gro_complete,
1663 	},
1664 };
1665 
1666 static const struct net_offload ipip_offload = {
1667 	.callbacks = {
1668 		.gso_send_check = inet_gso_send_check,
1669 		.gso_segment	= inet_gso_segment,
1670 	},
1671 };
1672 
1673 static int __init ipv4_offload_init(void)
1674 {
1675 	/*
1676 	 * Add offloads
1677 	 */
1678 	if (udpv4_offload_init() < 0)
1679 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1680 	if (tcpv4_offload_init() < 0)
1681 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1682 
1683 	dev_add_offload(&ip_packet_offload);
1684 	inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1685 	return 0;
1686 }
1687 
1688 fs_initcall(ipv4_offload_init);
1689 
1690 static struct packet_type ip_packet_type __read_mostly = {
1691 	.type = cpu_to_be16(ETH_P_IP),
1692 	.func = ip_rcv,
1693 };
1694 
1695 static int __init inet_init(void)
1696 {
1697 	struct inet_protosw *q;
1698 	struct list_head *r;
1699 	int rc = -EINVAL;
1700 
1701 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > FIELD_SIZEOF(struct sk_buff, cb));
1702 
1703 	rc = proto_register(&tcp_prot, 1);
1704 	if (rc)
1705 		goto out;
1706 
1707 	rc = proto_register(&udp_prot, 1);
1708 	if (rc)
1709 		goto out_unregister_tcp_proto;
1710 
1711 	rc = proto_register(&raw_prot, 1);
1712 	if (rc)
1713 		goto out_unregister_udp_proto;
1714 
1715 	rc = proto_register(&ping_prot, 1);
1716 	if (rc)
1717 		goto out_unregister_raw_proto;
1718 
1719 	/*
1720 	 *	Tell SOCKET that we are alive...
1721 	 */
1722 
1723 	(void)sock_register(&inet_family_ops);
1724 
1725 #ifdef CONFIG_SYSCTL
1726 	ip_static_sysctl_init();
1727 #endif
1728 
1729 	/*
1730 	 *	Add all the base protocols.
1731 	 */
1732 
1733 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1734 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1735 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1736 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1737 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1738 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1739 #ifdef CONFIG_IP_MULTICAST
1740 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1741 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1742 #endif
1743 
1744 	/* Register the socket-side information for inet_create. */
1745 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1746 		INIT_LIST_HEAD(r);
1747 
1748 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1749 		inet_register_protosw(q);
1750 
1751 	/*
1752 	 *	Set the ARP module up
1753 	 */
1754 
1755 	arp_init();
1756 
1757 	/*
1758 	 *	Set the IP module up
1759 	 */
1760 
1761 	ip_init();
1762 
1763 	tcp_v4_init();
1764 
1765 	/* Setup TCP slab cache for open requests. */
1766 	tcp_init();
1767 
1768 	/* Setup UDP memory threshold */
1769 	udp_init();
1770 
1771 	/* Add UDP-Lite (RFC 3828) */
1772 	udplite4_register();
1773 
1774 	ping_init();
1775 
1776 	/*
1777 	 *	Set the ICMP layer up
1778 	 */
1779 
1780 	if (icmp_init() < 0)
1781 		panic("Failed to create the ICMP control socket.\n");
1782 
1783 	/*
1784 	 *	Initialise the multicast router
1785 	 */
1786 #if defined(CONFIG_IP_MROUTE)
1787 	if (ip_mr_init())
1788 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1789 #endif
1790 
1791 	if (init_inet_pernet_ops())
1792 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1793 	/*
1794 	 *	Initialise per-cpu ipv4 mibs
1795 	 */
1796 
1797 	if (init_ipv4_mibs())
1798 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1799 
1800 	ipv4_proc_init();
1801 
1802 	ipfrag_init();
1803 
1804 	dev_add_pack(&ip_packet_type);
1805 
1806 	rc = 0;
1807 out:
1808 	return rc;
1809 out_unregister_raw_proto:
1810 	proto_unregister(&raw_prot);
1811 out_unregister_udp_proto:
1812 	proto_unregister(&udp_prot);
1813 out_unregister_tcp_proto:
1814 	proto_unregister(&tcp_prot);
1815 	goto out;
1816 }
1817 
1818 fs_initcall(inet_init);
1819 
1820 /* ------------------------------------------------------------------------ */
1821 
1822 #ifdef CONFIG_PROC_FS
1823 static int __init ipv4_proc_init(void)
1824 {
1825 	int rc = 0;
1826 
1827 	if (raw_proc_init())
1828 		goto out_raw;
1829 	if (tcp4_proc_init())
1830 		goto out_tcp;
1831 	if (udp4_proc_init())
1832 		goto out_udp;
1833 	if (ping_proc_init())
1834 		goto out_ping;
1835 	if (ip_misc_proc_init())
1836 		goto out_misc;
1837 out:
1838 	return rc;
1839 out_misc:
1840 	ping_proc_exit();
1841 out_ping:
1842 	udp4_proc_exit();
1843 out_udp:
1844 	tcp4_proc_exit();
1845 out_tcp:
1846 	raw_proc_exit();
1847 out_raw:
1848 	rc = -ENOMEM;
1849 	goto out;
1850 }
1851 
1852 #else /* CONFIG_PROC_FS */
1853 static int __init ipv4_proc_init(void)
1854 {
1855 	return 0;
1856 }
1857 #endif /* CONFIG_PROC_FS */
1858 
1859 MODULE_ALIAS_NETPROTO(PF_INET);
1860 
1861