xref: /openbmc/linux/net/ipv4/af_inet.c (revision d0b73b48)
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/ipip.h>
115 #include <net/inet_common.h>
116 #include <net/xfrm.h>
117 #include <net/net_namespace.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 /*
252  * inet_ehash_secret must be set exactly once
253  */
254 void build_ehash_secret(void)
255 {
256 	u32 rnd;
257 
258 	do {
259 		get_random_bytes(&rnd, sizeof(rnd));
260 	} while (rnd == 0);
261 
262 	cmpxchg(&inet_ehash_secret, 0, rnd);
263 }
264 EXPORT_SYMBOL(build_ehash_secret);
265 
266 static inline int inet_netns_ok(struct net *net, __u8 protocol)
267 {
268 	const struct net_protocol *ipprot;
269 
270 	if (net_eq(net, &init_net))
271 		return 1;
272 
273 	ipprot = rcu_dereference(inet_protos[protocol]);
274 	if (ipprot == NULL) {
275 		/* raw IP is OK */
276 		return 1;
277 	}
278 	return ipprot->netns_ok;
279 }
280 
281 /*
282  *	Create an inet socket.
283  */
284 
285 static int inet_create(struct net *net, struct socket *sock, int protocol,
286 		       int kern)
287 {
288 	struct sock *sk;
289 	struct inet_protosw *answer;
290 	struct inet_sock *inet;
291 	struct proto *answer_prot;
292 	unsigned char answer_flags;
293 	char answer_no_check;
294 	int try_loading_module = 0;
295 	int err;
296 
297 	if (unlikely(!inet_ehash_secret))
298 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
299 			build_ehash_secret();
300 
301 	sock->state = SS_UNCONNECTED;
302 
303 	/* Look for the requested type/protocol pair. */
304 lookup_protocol:
305 	err = -ESOCKTNOSUPPORT;
306 	rcu_read_lock();
307 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
308 
309 		err = 0;
310 		/* Check the non-wild match. */
311 		if (protocol == answer->protocol) {
312 			if (protocol != IPPROTO_IP)
313 				break;
314 		} else {
315 			/* Check for the two wild cases. */
316 			if (IPPROTO_IP == protocol) {
317 				protocol = answer->protocol;
318 				break;
319 			}
320 			if (IPPROTO_IP == answer->protocol)
321 				break;
322 		}
323 		err = -EPROTONOSUPPORT;
324 	}
325 
326 	if (unlikely(err)) {
327 		if (try_loading_module < 2) {
328 			rcu_read_unlock();
329 			/*
330 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
331 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
332 			 */
333 			if (++try_loading_module == 1)
334 				request_module("net-pf-%d-proto-%d-type-%d",
335 					       PF_INET, protocol, sock->type);
336 			/*
337 			 * Fall back to generic, e.g. net-pf-2-proto-132
338 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
339 			 */
340 			else
341 				request_module("net-pf-%d-proto-%d",
342 					       PF_INET, protocol);
343 			goto lookup_protocol;
344 		} else
345 			goto out_rcu_unlock;
346 	}
347 
348 	err = -EPERM;
349 	if (sock->type == SOCK_RAW && !kern &&
350 	    !ns_capable(net->user_ns, CAP_NET_RAW))
351 		goto out_rcu_unlock;
352 
353 	err = -EAFNOSUPPORT;
354 	if (!inet_netns_ok(net, protocol))
355 		goto out_rcu_unlock;
356 
357 	sock->ops = answer->ops;
358 	answer_prot = answer->prot;
359 	answer_no_check = answer->no_check;
360 	answer_flags = answer->flags;
361 	rcu_read_unlock();
362 
363 	WARN_ON(answer_prot->slab == NULL);
364 
365 	err = -ENOBUFS;
366 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
367 	if (sk == NULL)
368 		goto out;
369 
370 	err = 0;
371 	sk->sk_no_check = answer_no_check;
372 	if (INET_PROTOSW_REUSE & answer_flags)
373 		sk->sk_reuse = SK_CAN_REUSE;
374 
375 	inet = inet_sk(sk);
376 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
377 
378 	inet->nodefrag = 0;
379 
380 	if (SOCK_RAW == sock->type) {
381 		inet->inet_num = protocol;
382 		if (IPPROTO_RAW == protocol)
383 			inet->hdrincl = 1;
384 	}
385 
386 	if (ipv4_config.no_pmtu_disc)
387 		inet->pmtudisc = IP_PMTUDISC_DONT;
388 	else
389 		inet->pmtudisc = IP_PMTUDISC_WANT;
390 
391 	inet->inet_id = 0;
392 
393 	sock_init_data(sock, sk);
394 
395 	sk->sk_destruct	   = inet_sock_destruct;
396 	sk->sk_protocol	   = protocol;
397 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
398 
399 	inet->uc_ttl	= -1;
400 	inet->mc_loop	= 1;
401 	inet->mc_ttl	= 1;
402 	inet->mc_all	= 1;
403 	inet->mc_index	= 0;
404 	inet->mc_list	= NULL;
405 	inet->rcv_tos	= 0;
406 
407 	sk_refcnt_debug_inc(sk);
408 
409 	if (inet->inet_num) {
410 		/* It assumes that any protocol which allows
411 		 * the user to assign a number at socket
412 		 * creation time automatically
413 		 * shares.
414 		 */
415 		inet->inet_sport = htons(inet->inet_num);
416 		/* Add to protocol hash chains. */
417 		sk->sk_prot->hash(sk);
418 	}
419 
420 	if (sk->sk_prot->init) {
421 		err = sk->sk_prot->init(sk);
422 		if (err)
423 			sk_common_release(sk);
424 	}
425 out:
426 	return err;
427 out_rcu_unlock:
428 	rcu_read_unlock();
429 	goto out;
430 }
431 
432 
433 /*
434  *	The peer socket should always be NULL (or else). When we call this
435  *	function we are destroying the object and from then on nobody
436  *	should refer to it.
437  */
438 int inet_release(struct socket *sock)
439 {
440 	struct sock *sk = sock->sk;
441 
442 	if (sk) {
443 		long timeout;
444 
445 		sock_rps_reset_flow(sk);
446 
447 		/* Applications forget to leave groups before exiting */
448 		ip_mc_drop_socket(sk);
449 
450 		/* If linger is set, we don't return until the close
451 		 * is complete.  Otherwise we return immediately. The
452 		 * actually closing is done the same either way.
453 		 *
454 		 * If the close is due to the process exiting, we never
455 		 * linger..
456 		 */
457 		timeout = 0;
458 		if (sock_flag(sk, SOCK_LINGER) &&
459 		    !(current->flags & PF_EXITING))
460 			timeout = sk->sk_lingertime;
461 		sock->sk = NULL;
462 		sk->sk_prot->close(sk, timeout);
463 	}
464 	return 0;
465 }
466 EXPORT_SYMBOL(inet_release);
467 
468 /* It is off by default, see below. */
469 int sysctl_ip_nonlocal_bind __read_mostly;
470 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
471 
472 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
473 {
474 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
475 	struct sock *sk = sock->sk;
476 	struct inet_sock *inet = inet_sk(sk);
477 	struct net *net = sock_net(sk);
478 	unsigned short snum;
479 	int chk_addr_ret;
480 	int err;
481 
482 	/* If the socket has its own bind function then use it. (RAW) */
483 	if (sk->sk_prot->bind) {
484 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
485 		goto out;
486 	}
487 	err = -EINVAL;
488 	if (addr_len < sizeof(struct sockaddr_in))
489 		goto out;
490 
491 	if (addr->sin_family != AF_INET) {
492 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
493 		 * only if s_addr is INADDR_ANY.
494 		 */
495 		err = -EAFNOSUPPORT;
496 		if (addr->sin_family != AF_UNSPEC ||
497 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
498 			goto out;
499 	}
500 
501 	chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
502 
503 	/* Not specified by any standard per-se, however it breaks too
504 	 * many applications when removed.  It is unfortunate since
505 	 * allowing applications to make a non-local bind solves
506 	 * several problems with systems using dynamic addressing.
507 	 * (ie. your servers still start up even if your ISDN link
508 	 *  is temporarily down)
509 	 */
510 	err = -EADDRNOTAVAIL;
511 	if (!sysctl_ip_nonlocal_bind &&
512 	    !(inet->freebind || inet->transparent) &&
513 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
514 	    chk_addr_ret != RTN_LOCAL &&
515 	    chk_addr_ret != RTN_MULTICAST &&
516 	    chk_addr_ret != RTN_BROADCAST)
517 		goto out;
518 
519 	snum = ntohs(addr->sin_port);
520 	err = -EACCES;
521 	if (snum && snum < PROT_SOCK &&
522 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
523 		goto out;
524 
525 	/*      We keep a pair of addresses. rcv_saddr is the one
526 	 *      used by hash lookups, and saddr is used for transmit.
527 	 *
528 	 *      In the BSD API these are the same except where it
529 	 *      would be illegal to use them (multicast/broadcast) in
530 	 *      which case the sending device address is used.
531 	 */
532 	lock_sock(sk);
533 
534 	/* Check these errors (active socket, double bind). */
535 	err = -EINVAL;
536 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
537 		goto out_release_sock;
538 
539 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
540 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
541 		inet->inet_saddr = 0;  /* Use device */
542 
543 	/* Make sure we are allowed to bind here. */
544 	if (sk->sk_prot->get_port(sk, snum)) {
545 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
546 		err = -EADDRINUSE;
547 		goto out_release_sock;
548 	}
549 
550 	if (inet->inet_rcv_saddr)
551 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
552 	if (snum)
553 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
554 	inet->inet_sport = htons(inet->inet_num);
555 	inet->inet_daddr = 0;
556 	inet->inet_dport = 0;
557 	sk_dst_reset(sk);
558 	err = 0;
559 out_release_sock:
560 	release_sock(sk);
561 out:
562 	return err;
563 }
564 EXPORT_SYMBOL(inet_bind);
565 
566 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
567 		       int addr_len, int flags)
568 {
569 	struct sock *sk = sock->sk;
570 
571 	if (addr_len < sizeof(uaddr->sa_family))
572 		return -EINVAL;
573 	if (uaddr->sa_family == AF_UNSPEC)
574 		return sk->sk_prot->disconnect(sk, flags);
575 
576 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
577 		return -EAGAIN;
578 	return sk->sk_prot->connect(sk, uaddr, addr_len);
579 }
580 EXPORT_SYMBOL(inet_dgram_connect);
581 
582 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
583 {
584 	DEFINE_WAIT(wait);
585 
586 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
587 	sk->sk_write_pending += writebias;
588 
589 	/* Basic assumption: if someone sets sk->sk_err, he _must_
590 	 * change state of the socket from TCP_SYN_*.
591 	 * Connect() does not allow to get error notifications
592 	 * without closing the socket.
593 	 */
594 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
595 		release_sock(sk);
596 		timeo = schedule_timeout(timeo);
597 		lock_sock(sk);
598 		if (signal_pending(current) || !timeo)
599 			break;
600 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
601 	}
602 	finish_wait(sk_sleep(sk), &wait);
603 	sk->sk_write_pending -= writebias;
604 	return timeo;
605 }
606 
607 /*
608  *	Connect to a remote host. There is regrettably still a little
609  *	TCP 'magic' in here.
610  */
611 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
612 			  int addr_len, int flags)
613 {
614 	struct sock *sk = sock->sk;
615 	int err;
616 	long timeo;
617 
618 	if (addr_len < sizeof(uaddr->sa_family))
619 		return -EINVAL;
620 
621 	if (uaddr->sa_family == AF_UNSPEC) {
622 		err = sk->sk_prot->disconnect(sk, flags);
623 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
624 		goto out;
625 	}
626 
627 	switch (sock->state) {
628 	default:
629 		err = -EINVAL;
630 		goto out;
631 	case SS_CONNECTED:
632 		err = -EISCONN;
633 		goto out;
634 	case SS_CONNECTING:
635 		err = -EALREADY;
636 		/* Fall out of switch with err, set for this state */
637 		break;
638 	case SS_UNCONNECTED:
639 		err = -EISCONN;
640 		if (sk->sk_state != TCP_CLOSE)
641 			goto out;
642 
643 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
644 		if (err < 0)
645 			goto out;
646 
647 		sock->state = SS_CONNECTING;
648 
649 		/* Just entered SS_CONNECTING state; the only
650 		 * difference is that return value in non-blocking
651 		 * case is EINPROGRESS, rather than EALREADY.
652 		 */
653 		err = -EINPROGRESS;
654 		break;
655 	}
656 
657 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
658 
659 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
660 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
661 				tcp_sk(sk)->fastopen_req &&
662 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
663 
664 		/* Error code is set above */
665 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
666 			goto out;
667 
668 		err = sock_intr_errno(timeo);
669 		if (signal_pending(current))
670 			goto out;
671 	}
672 
673 	/* Connection was closed by RST, timeout, ICMP error
674 	 * or another process disconnected us.
675 	 */
676 	if (sk->sk_state == TCP_CLOSE)
677 		goto sock_error;
678 
679 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
680 	 * and error was received after socket entered established state.
681 	 * Hence, it is handled normally after connect() return successfully.
682 	 */
683 
684 	sock->state = SS_CONNECTED;
685 	err = 0;
686 out:
687 	return err;
688 
689 sock_error:
690 	err = sock_error(sk) ? : -ECONNABORTED;
691 	sock->state = SS_UNCONNECTED;
692 	if (sk->sk_prot->disconnect(sk, flags))
693 		sock->state = SS_DISCONNECTING;
694 	goto out;
695 }
696 EXPORT_SYMBOL(__inet_stream_connect);
697 
698 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
699 			int addr_len, int flags)
700 {
701 	int err;
702 
703 	lock_sock(sock->sk);
704 	err = __inet_stream_connect(sock, uaddr, addr_len, flags);
705 	release_sock(sock->sk);
706 	return err;
707 }
708 EXPORT_SYMBOL(inet_stream_connect);
709 
710 /*
711  *	Accept a pending connection. The TCP layer now gives BSD semantics.
712  */
713 
714 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
715 {
716 	struct sock *sk1 = sock->sk;
717 	int err = -EINVAL;
718 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
719 
720 	if (!sk2)
721 		goto do_err;
722 
723 	lock_sock(sk2);
724 
725 	sock_rps_record_flow(sk2);
726 	WARN_ON(!((1 << sk2->sk_state) &
727 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
728 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
729 
730 	sock_graft(sk2, newsock);
731 
732 	newsock->state = SS_CONNECTED;
733 	err = 0;
734 	release_sock(sk2);
735 do_err:
736 	return err;
737 }
738 EXPORT_SYMBOL(inet_accept);
739 
740 
741 /*
742  *	This does both peername and sockname.
743  */
744 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
745 			int *uaddr_len, int peer)
746 {
747 	struct sock *sk		= sock->sk;
748 	struct inet_sock *inet	= inet_sk(sk);
749 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
750 
751 	sin->sin_family = AF_INET;
752 	if (peer) {
753 		if (!inet->inet_dport ||
754 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
755 		     peer == 1))
756 			return -ENOTCONN;
757 		sin->sin_port = inet->inet_dport;
758 		sin->sin_addr.s_addr = inet->inet_daddr;
759 	} else {
760 		__be32 addr = inet->inet_rcv_saddr;
761 		if (!addr)
762 			addr = inet->inet_saddr;
763 		sin->sin_port = inet->inet_sport;
764 		sin->sin_addr.s_addr = addr;
765 	}
766 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
767 	*uaddr_len = sizeof(*sin);
768 	return 0;
769 }
770 EXPORT_SYMBOL(inet_getname);
771 
772 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
773 		 size_t size)
774 {
775 	struct sock *sk = sock->sk;
776 
777 	sock_rps_record_flow(sk);
778 
779 	/* We may need to bind the socket. */
780 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
781 	    inet_autobind(sk))
782 		return -EAGAIN;
783 
784 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
785 }
786 EXPORT_SYMBOL(inet_sendmsg);
787 
788 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
789 		      size_t size, int flags)
790 {
791 	struct sock *sk = sock->sk;
792 
793 	sock_rps_record_flow(sk);
794 
795 	/* We may need to bind the socket. */
796 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
797 	    inet_autobind(sk))
798 		return -EAGAIN;
799 
800 	if (sk->sk_prot->sendpage)
801 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
802 	return sock_no_sendpage(sock, page, offset, size, flags);
803 }
804 EXPORT_SYMBOL(inet_sendpage);
805 
806 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
807 		 size_t size, int flags)
808 {
809 	struct sock *sk = sock->sk;
810 	int addr_len = 0;
811 	int err;
812 
813 	sock_rps_record_flow(sk);
814 
815 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
816 				   flags & ~MSG_DONTWAIT, &addr_len);
817 	if (err >= 0)
818 		msg->msg_namelen = addr_len;
819 	return err;
820 }
821 EXPORT_SYMBOL(inet_recvmsg);
822 
823 int inet_shutdown(struct socket *sock, int how)
824 {
825 	struct sock *sk = sock->sk;
826 	int err = 0;
827 
828 	/* This should really check to make sure
829 	 * the socket is a TCP socket. (WHY AC...)
830 	 */
831 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
832 		       1->2 bit 2 snds.
833 		       2->3 */
834 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
835 		return -EINVAL;
836 
837 	lock_sock(sk);
838 	if (sock->state == SS_CONNECTING) {
839 		if ((1 << sk->sk_state) &
840 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
841 			sock->state = SS_DISCONNECTING;
842 		else
843 			sock->state = SS_CONNECTED;
844 	}
845 
846 	switch (sk->sk_state) {
847 	case TCP_CLOSE:
848 		err = -ENOTCONN;
849 		/* Hack to wake up other listeners, who can poll for
850 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
851 	default:
852 		sk->sk_shutdown |= how;
853 		if (sk->sk_prot->shutdown)
854 			sk->sk_prot->shutdown(sk, how);
855 		break;
856 
857 	/* Remaining two branches are temporary solution for missing
858 	 * close() in multithreaded environment. It is _not_ a good idea,
859 	 * but we have no choice until close() is repaired at VFS level.
860 	 */
861 	case TCP_LISTEN:
862 		if (!(how & RCV_SHUTDOWN))
863 			break;
864 		/* Fall through */
865 	case TCP_SYN_SENT:
866 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
867 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
868 		break;
869 	}
870 
871 	/* Wake up anyone sleeping in poll. */
872 	sk->sk_state_change(sk);
873 	release_sock(sk);
874 	return err;
875 }
876 EXPORT_SYMBOL(inet_shutdown);
877 
878 /*
879  *	ioctl() calls you can issue on an INET socket. Most of these are
880  *	device configuration and stuff and very rarely used. Some ioctls
881  *	pass on to the socket itself.
882  *
883  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
884  *	loads the devconfigure module does its configuring and unloads it.
885  *	There's a good 20K of config code hanging around the kernel.
886  */
887 
888 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
889 {
890 	struct sock *sk = sock->sk;
891 	int err = 0;
892 	struct net *net = sock_net(sk);
893 
894 	switch (cmd) {
895 	case SIOCGSTAMP:
896 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
897 		break;
898 	case SIOCGSTAMPNS:
899 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
900 		break;
901 	case SIOCADDRT:
902 	case SIOCDELRT:
903 	case SIOCRTMSG:
904 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
905 		break;
906 	case SIOCDARP:
907 	case SIOCGARP:
908 	case SIOCSARP:
909 		err = arp_ioctl(net, cmd, (void __user *)arg);
910 		break;
911 	case SIOCGIFADDR:
912 	case SIOCSIFADDR:
913 	case SIOCGIFBRDADDR:
914 	case SIOCSIFBRDADDR:
915 	case SIOCGIFNETMASK:
916 	case SIOCSIFNETMASK:
917 	case SIOCGIFDSTADDR:
918 	case SIOCSIFDSTADDR:
919 	case SIOCSIFPFLAGS:
920 	case SIOCGIFPFLAGS:
921 	case SIOCSIFFLAGS:
922 		err = devinet_ioctl(net, cmd, (void __user *)arg);
923 		break;
924 	default:
925 		if (sk->sk_prot->ioctl)
926 			err = sk->sk_prot->ioctl(sk, cmd, arg);
927 		else
928 			err = -ENOIOCTLCMD;
929 		break;
930 	}
931 	return err;
932 }
933 EXPORT_SYMBOL(inet_ioctl);
934 
935 #ifdef CONFIG_COMPAT
936 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
937 {
938 	struct sock *sk = sock->sk;
939 	int err = -ENOIOCTLCMD;
940 
941 	if (sk->sk_prot->compat_ioctl)
942 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
943 
944 	return err;
945 }
946 #endif
947 
948 const struct proto_ops inet_stream_ops = {
949 	.family		   = PF_INET,
950 	.owner		   = THIS_MODULE,
951 	.release	   = inet_release,
952 	.bind		   = inet_bind,
953 	.connect	   = inet_stream_connect,
954 	.socketpair	   = sock_no_socketpair,
955 	.accept		   = inet_accept,
956 	.getname	   = inet_getname,
957 	.poll		   = tcp_poll,
958 	.ioctl		   = inet_ioctl,
959 	.listen		   = inet_listen,
960 	.shutdown	   = inet_shutdown,
961 	.setsockopt	   = sock_common_setsockopt,
962 	.getsockopt	   = sock_common_getsockopt,
963 	.sendmsg	   = inet_sendmsg,
964 	.recvmsg	   = inet_recvmsg,
965 	.mmap		   = sock_no_mmap,
966 	.sendpage	   = inet_sendpage,
967 	.splice_read	   = tcp_splice_read,
968 #ifdef CONFIG_COMPAT
969 	.compat_setsockopt = compat_sock_common_setsockopt,
970 	.compat_getsockopt = compat_sock_common_getsockopt,
971 	.compat_ioctl	   = inet_compat_ioctl,
972 #endif
973 };
974 EXPORT_SYMBOL(inet_stream_ops);
975 
976 const struct proto_ops inet_dgram_ops = {
977 	.family		   = PF_INET,
978 	.owner		   = THIS_MODULE,
979 	.release	   = inet_release,
980 	.bind		   = inet_bind,
981 	.connect	   = inet_dgram_connect,
982 	.socketpair	   = sock_no_socketpair,
983 	.accept		   = sock_no_accept,
984 	.getname	   = inet_getname,
985 	.poll		   = udp_poll,
986 	.ioctl		   = inet_ioctl,
987 	.listen		   = sock_no_listen,
988 	.shutdown	   = inet_shutdown,
989 	.setsockopt	   = sock_common_setsockopt,
990 	.getsockopt	   = sock_common_getsockopt,
991 	.sendmsg	   = inet_sendmsg,
992 	.recvmsg	   = inet_recvmsg,
993 	.mmap		   = sock_no_mmap,
994 	.sendpage	   = inet_sendpage,
995 #ifdef CONFIG_COMPAT
996 	.compat_setsockopt = compat_sock_common_setsockopt,
997 	.compat_getsockopt = compat_sock_common_getsockopt,
998 	.compat_ioctl	   = inet_compat_ioctl,
999 #endif
1000 };
1001 EXPORT_SYMBOL(inet_dgram_ops);
1002 
1003 /*
1004  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1005  * udp_poll
1006  */
1007 static const struct proto_ops inet_sockraw_ops = {
1008 	.family		   = PF_INET,
1009 	.owner		   = THIS_MODULE,
1010 	.release	   = inet_release,
1011 	.bind		   = inet_bind,
1012 	.connect	   = inet_dgram_connect,
1013 	.socketpair	   = sock_no_socketpair,
1014 	.accept		   = sock_no_accept,
1015 	.getname	   = inet_getname,
1016 	.poll		   = datagram_poll,
1017 	.ioctl		   = inet_ioctl,
1018 	.listen		   = sock_no_listen,
1019 	.shutdown	   = inet_shutdown,
1020 	.setsockopt	   = sock_common_setsockopt,
1021 	.getsockopt	   = sock_common_getsockopt,
1022 	.sendmsg	   = inet_sendmsg,
1023 	.recvmsg	   = inet_recvmsg,
1024 	.mmap		   = sock_no_mmap,
1025 	.sendpage	   = inet_sendpage,
1026 #ifdef CONFIG_COMPAT
1027 	.compat_setsockopt = compat_sock_common_setsockopt,
1028 	.compat_getsockopt = compat_sock_common_getsockopt,
1029 	.compat_ioctl	   = inet_compat_ioctl,
1030 #endif
1031 };
1032 
1033 static const struct net_proto_family inet_family_ops = {
1034 	.family = PF_INET,
1035 	.create = inet_create,
1036 	.owner	= THIS_MODULE,
1037 };
1038 
1039 /* Upon startup we insert all the elements in inetsw_array[] into
1040  * the linked list inetsw.
1041  */
1042 static struct inet_protosw inetsw_array[] =
1043 {
1044 	{
1045 		.type =       SOCK_STREAM,
1046 		.protocol =   IPPROTO_TCP,
1047 		.prot =       &tcp_prot,
1048 		.ops =        &inet_stream_ops,
1049 		.no_check =   0,
1050 		.flags =      INET_PROTOSW_PERMANENT |
1051 			      INET_PROTOSW_ICSK,
1052 	},
1053 
1054 	{
1055 		.type =       SOCK_DGRAM,
1056 		.protocol =   IPPROTO_UDP,
1057 		.prot =       &udp_prot,
1058 		.ops =        &inet_dgram_ops,
1059 		.no_check =   UDP_CSUM_DEFAULT,
1060 		.flags =      INET_PROTOSW_PERMANENT,
1061        },
1062 
1063        {
1064 		.type =       SOCK_DGRAM,
1065 		.protocol =   IPPROTO_ICMP,
1066 		.prot =       &ping_prot,
1067 		.ops =        &inet_dgram_ops,
1068 		.no_check =   UDP_CSUM_DEFAULT,
1069 		.flags =      INET_PROTOSW_REUSE,
1070        },
1071 
1072        {
1073 	       .type =       SOCK_RAW,
1074 	       .protocol =   IPPROTO_IP,	/* wild card */
1075 	       .prot =       &raw_prot,
1076 	       .ops =        &inet_sockraw_ops,
1077 	       .no_check =   UDP_CSUM_DEFAULT,
1078 	       .flags =      INET_PROTOSW_REUSE,
1079        }
1080 };
1081 
1082 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1083 
1084 void inet_register_protosw(struct inet_protosw *p)
1085 {
1086 	struct list_head *lh;
1087 	struct inet_protosw *answer;
1088 	int protocol = p->protocol;
1089 	struct list_head *last_perm;
1090 
1091 	spin_lock_bh(&inetsw_lock);
1092 
1093 	if (p->type >= SOCK_MAX)
1094 		goto out_illegal;
1095 
1096 	/* If we are trying to override a permanent protocol, bail. */
1097 	answer = NULL;
1098 	last_perm = &inetsw[p->type];
1099 	list_for_each(lh, &inetsw[p->type]) {
1100 		answer = list_entry(lh, struct inet_protosw, list);
1101 
1102 		/* Check only the non-wild match. */
1103 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1104 			if (protocol == answer->protocol)
1105 				break;
1106 			last_perm = lh;
1107 		}
1108 
1109 		answer = NULL;
1110 	}
1111 	if (answer)
1112 		goto out_permanent;
1113 
1114 	/* Add the new entry after the last permanent entry if any, so that
1115 	 * the new entry does not override a permanent entry when matched with
1116 	 * a wild-card protocol. But it is allowed to override any existing
1117 	 * non-permanent entry.  This means that when we remove this entry, the
1118 	 * system automatically returns to the old behavior.
1119 	 */
1120 	list_add_rcu(&p->list, last_perm);
1121 out:
1122 	spin_unlock_bh(&inetsw_lock);
1123 
1124 	return;
1125 
1126 out_permanent:
1127 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1128 	goto out;
1129 
1130 out_illegal:
1131 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1132 	       p->type);
1133 	goto out;
1134 }
1135 EXPORT_SYMBOL(inet_register_protosw);
1136 
1137 void inet_unregister_protosw(struct inet_protosw *p)
1138 {
1139 	if (INET_PROTOSW_PERMANENT & p->flags) {
1140 		pr_err("Attempt to unregister permanent protocol %d\n",
1141 		       p->protocol);
1142 	} else {
1143 		spin_lock_bh(&inetsw_lock);
1144 		list_del_rcu(&p->list);
1145 		spin_unlock_bh(&inetsw_lock);
1146 
1147 		synchronize_net();
1148 	}
1149 }
1150 EXPORT_SYMBOL(inet_unregister_protosw);
1151 
1152 /*
1153  *      Shall we try to damage output packets if routing dev changes?
1154  */
1155 
1156 int sysctl_ip_dynaddr __read_mostly;
1157 
1158 static int inet_sk_reselect_saddr(struct sock *sk)
1159 {
1160 	struct inet_sock *inet = inet_sk(sk);
1161 	__be32 old_saddr = inet->inet_saddr;
1162 	__be32 daddr = inet->inet_daddr;
1163 	struct flowi4 *fl4;
1164 	struct rtable *rt;
1165 	__be32 new_saddr;
1166 	struct ip_options_rcu *inet_opt;
1167 
1168 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1169 					     sock_owned_by_user(sk));
1170 	if (inet_opt && inet_opt->opt.srr)
1171 		daddr = inet_opt->opt.faddr;
1172 
1173 	/* Query new route. */
1174 	fl4 = &inet->cork.fl.u.ip4;
1175 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1176 			      sk->sk_bound_dev_if, sk->sk_protocol,
1177 			      inet->inet_sport, inet->inet_dport, sk, false);
1178 	if (IS_ERR(rt))
1179 		return PTR_ERR(rt);
1180 
1181 	sk_setup_caps(sk, &rt->dst);
1182 
1183 	new_saddr = fl4->saddr;
1184 
1185 	if (new_saddr == old_saddr)
1186 		return 0;
1187 
1188 	if (sysctl_ip_dynaddr > 1) {
1189 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1190 			__func__, &old_saddr, &new_saddr);
1191 	}
1192 
1193 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1194 
1195 	/*
1196 	 * XXX The only one ugly spot where we need to
1197 	 * XXX really change the sockets identity after
1198 	 * XXX it has entered the hashes. -DaveM
1199 	 *
1200 	 * Besides that, it does not check for connection
1201 	 * uniqueness. Wait for troubles.
1202 	 */
1203 	__sk_prot_rehash(sk);
1204 	return 0;
1205 }
1206 
1207 int inet_sk_rebuild_header(struct sock *sk)
1208 {
1209 	struct inet_sock *inet = inet_sk(sk);
1210 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1211 	__be32 daddr;
1212 	struct ip_options_rcu *inet_opt;
1213 	struct flowi4 *fl4;
1214 	int err;
1215 
1216 	/* Route is OK, nothing to do. */
1217 	if (rt)
1218 		return 0;
1219 
1220 	/* Reroute. */
1221 	rcu_read_lock();
1222 	inet_opt = rcu_dereference(inet->inet_opt);
1223 	daddr = inet->inet_daddr;
1224 	if (inet_opt && inet_opt->opt.srr)
1225 		daddr = inet_opt->opt.faddr;
1226 	rcu_read_unlock();
1227 	fl4 = &inet->cork.fl.u.ip4;
1228 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1229 				   inet->inet_dport, inet->inet_sport,
1230 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1231 				   sk->sk_bound_dev_if);
1232 	if (!IS_ERR(rt)) {
1233 		err = 0;
1234 		sk_setup_caps(sk, &rt->dst);
1235 	} else {
1236 		err = PTR_ERR(rt);
1237 
1238 		/* Routing failed... */
1239 		sk->sk_route_caps = 0;
1240 		/*
1241 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1242 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1243 		 */
1244 		if (!sysctl_ip_dynaddr ||
1245 		    sk->sk_state != TCP_SYN_SENT ||
1246 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1247 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1248 			sk->sk_err_soft = -err;
1249 	}
1250 
1251 	return err;
1252 }
1253 EXPORT_SYMBOL(inet_sk_rebuild_header);
1254 
1255 static int inet_gso_send_check(struct sk_buff *skb)
1256 {
1257 	const struct net_offload *ops;
1258 	const struct iphdr *iph;
1259 	int proto;
1260 	int ihl;
1261 	int err = -EINVAL;
1262 
1263 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1264 		goto out;
1265 
1266 	iph = ip_hdr(skb);
1267 	ihl = iph->ihl * 4;
1268 	if (ihl < sizeof(*iph))
1269 		goto out;
1270 
1271 	if (unlikely(!pskb_may_pull(skb, ihl)))
1272 		goto out;
1273 
1274 	__skb_pull(skb, ihl);
1275 	skb_reset_transport_header(skb);
1276 	iph = ip_hdr(skb);
1277 	proto = iph->protocol;
1278 	err = -EPROTONOSUPPORT;
1279 
1280 	rcu_read_lock();
1281 	ops = rcu_dereference(inet_offloads[proto]);
1282 	if (likely(ops && ops->callbacks.gso_send_check))
1283 		err = ops->callbacks.gso_send_check(skb);
1284 	rcu_read_unlock();
1285 
1286 out:
1287 	return err;
1288 }
1289 
1290 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1291 	netdev_features_t features)
1292 {
1293 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1294 	const struct net_offload *ops;
1295 	struct iphdr *iph;
1296 	int proto;
1297 	int ihl;
1298 	int id;
1299 	unsigned int offset = 0;
1300 
1301 	if (!(features & NETIF_F_V4_CSUM))
1302 		features &= ~NETIF_F_SG;
1303 
1304 	if (unlikely(skb_shinfo(skb)->gso_type &
1305 		     ~(SKB_GSO_TCPV4 |
1306 		       SKB_GSO_UDP |
1307 		       SKB_GSO_DODGY |
1308 		       SKB_GSO_TCP_ECN |
1309 		       0)))
1310 		goto out;
1311 
1312 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1313 		goto out;
1314 
1315 	iph = ip_hdr(skb);
1316 	ihl = iph->ihl * 4;
1317 	if (ihl < sizeof(*iph))
1318 		goto out;
1319 
1320 	if (unlikely(!pskb_may_pull(skb, ihl)))
1321 		goto out;
1322 
1323 	__skb_pull(skb, ihl);
1324 	skb_reset_transport_header(skb);
1325 	iph = ip_hdr(skb);
1326 	id = ntohs(iph->id);
1327 	proto = iph->protocol;
1328 	segs = ERR_PTR(-EPROTONOSUPPORT);
1329 
1330 	rcu_read_lock();
1331 	ops = rcu_dereference(inet_offloads[proto]);
1332 	if (likely(ops && ops->callbacks.gso_segment))
1333 		segs = ops->callbacks.gso_segment(skb, features);
1334 	rcu_read_unlock();
1335 
1336 	if (!segs || IS_ERR(segs))
1337 		goto out;
1338 
1339 	skb = segs;
1340 	do {
1341 		iph = ip_hdr(skb);
1342 		if (proto == IPPROTO_UDP) {
1343 			iph->id = htons(id);
1344 			iph->frag_off = htons(offset >> 3);
1345 			if (skb->next != NULL)
1346 				iph->frag_off |= htons(IP_MF);
1347 			offset += (skb->len - skb->mac_len - iph->ihl * 4);
1348 		} else
1349 			iph->id = htons(id++);
1350 		iph->tot_len = htons(skb->len - skb->mac_len);
1351 		iph->check = 0;
1352 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1353 	} while ((skb = skb->next));
1354 
1355 out:
1356 	return segs;
1357 }
1358 
1359 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1360 					 struct sk_buff *skb)
1361 {
1362 	const struct net_offload *ops;
1363 	struct sk_buff **pp = NULL;
1364 	struct sk_buff *p;
1365 	const struct iphdr *iph;
1366 	unsigned int hlen;
1367 	unsigned int off;
1368 	unsigned int id;
1369 	int flush = 1;
1370 	int proto;
1371 
1372 	off = skb_gro_offset(skb);
1373 	hlen = off + sizeof(*iph);
1374 	iph = skb_gro_header_fast(skb, off);
1375 	if (skb_gro_header_hard(skb, hlen)) {
1376 		iph = skb_gro_header_slow(skb, hlen, off);
1377 		if (unlikely(!iph))
1378 			goto out;
1379 	}
1380 
1381 	proto = iph->protocol;
1382 
1383 	rcu_read_lock();
1384 	ops = rcu_dereference(inet_offloads[proto]);
1385 	if (!ops || !ops->callbacks.gro_receive)
1386 		goto out_unlock;
1387 
1388 	if (*(u8 *)iph != 0x45)
1389 		goto out_unlock;
1390 
1391 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1392 		goto out_unlock;
1393 
1394 	id = ntohl(*(__be32 *)&iph->id);
1395 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id ^ IP_DF));
1396 	id >>= 16;
1397 
1398 	for (p = *head; p; p = p->next) {
1399 		struct iphdr *iph2;
1400 
1401 		if (!NAPI_GRO_CB(p)->same_flow)
1402 			continue;
1403 
1404 		iph2 = ip_hdr(p);
1405 
1406 		if ((iph->protocol ^ iph2->protocol) |
1407 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1408 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1409 			NAPI_GRO_CB(p)->same_flow = 0;
1410 			continue;
1411 		}
1412 
1413 		/* All fields must match except length and checksum. */
1414 		NAPI_GRO_CB(p)->flush |=
1415 			(iph->ttl ^ iph2->ttl) |
1416 			(iph->tos ^ iph2->tos) |
1417 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1418 
1419 		NAPI_GRO_CB(p)->flush |= flush;
1420 	}
1421 
1422 	NAPI_GRO_CB(skb)->flush |= flush;
1423 	skb_gro_pull(skb, sizeof(*iph));
1424 	skb_set_transport_header(skb, skb_gro_offset(skb));
1425 
1426 	pp = ops->callbacks.gro_receive(head, skb);
1427 
1428 out_unlock:
1429 	rcu_read_unlock();
1430 
1431 out:
1432 	NAPI_GRO_CB(skb)->flush |= flush;
1433 
1434 	return pp;
1435 }
1436 
1437 static int inet_gro_complete(struct sk_buff *skb)
1438 {
1439 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1440 	struct iphdr *iph = ip_hdr(skb);
1441 	const struct net_offload *ops;
1442 	int proto = iph->protocol;
1443 	int err = -ENOSYS;
1444 
1445 	csum_replace2(&iph->check, iph->tot_len, newlen);
1446 	iph->tot_len = newlen;
1447 
1448 	rcu_read_lock();
1449 	ops = rcu_dereference(inet_offloads[proto]);
1450 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1451 		goto out_unlock;
1452 
1453 	err = ops->callbacks.gro_complete(skb);
1454 
1455 out_unlock:
1456 	rcu_read_unlock();
1457 
1458 	return err;
1459 }
1460 
1461 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1462 			 unsigned short type, unsigned char protocol,
1463 			 struct net *net)
1464 {
1465 	struct socket *sock;
1466 	int rc = sock_create_kern(family, type, protocol, &sock);
1467 
1468 	if (rc == 0) {
1469 		*sk = sock->sk;
1470 		(*sk)->sk_allocation = GFP_ATOMIC;
1471 		/*
1472 		 * Unhash it so that IP input processing does not even see it,
1473 		 * we do not wish this socket to see incoming packets.
1474 		 */
1475 		(*sk)->sk_prot->unhash(*sk);
1476 
1477 		sk_change_net(*sk, net);
1478 	}
1479 	return rc;
1480 }
1481 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1482 
1483 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1484 {
1485 	unsigned long res = 0;
1486 	int i, j;
1487 
1488 	for_each_possible_cpu(i) {
1489 		for (j = 0; j < SNMP_ARRAY_SZ; j++)
1490 			res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1491 	}
1492 	return res;
1493 }
1494 EXPORT_SYMBOL_GPL(snmp_fold_field);
1495 
1496 #if BITS_PER_LONG==32
1497 
1498 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1499 {
1500 	u64 res = 0;
1501 	int cpu;
1502 
1503 	for_each_possible_cpu(cpu) {
1504 		void *bhptr;
1505 		struct u64_stats_sync *syncp;
1506 		u64 v;
1507 		unsigned int start;
1508 
1509 		bhptr = per_cpu_ptr(mib[0], cpu);
1510 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1511 		do {
1512 			start = u64_stats_fetch_begin_bh(syncp);
1513 			v = *(((u64 *) bhptr) + offt);
1514 		} while (u64_stats_fetch_retry_bh(syncp, start));
1515 
1516 		res += v;
1517 	}
1518 	return res;
1519 }
1520 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1521 #endif
1522 
1523 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1524 {
1525 	BUG_ON(ptr == NULL);
1526 	ptr[0] = __alloc_percpu(mibsize, align);
1527 	if (!ptr[0])
1528 		return -ENOMEM;
1529 #if SNMP_ARRAY_SZ == 2
1530 	ptr[1] = __alloc_percpu(mibsize, align);
1531 	if (!ptr[1]) {
1532 		free_percpu(ptr[0]);
1533 		ptr[0] = NULL;
1534 		return -ENOMEM;
1535 	}
1536 #endif
1537 	return 0;
1538 }
1539 EXPORT_SYMBOL_GPL(snmp_mib_init);
1540 
1541 void snmp_mib_free(void __percpu *ptr[SNMP_ARRAY_SZ])
1542 {
1543 	int i;
1544 
1545 	BUG_ON(ptr == NULL);
1546 	for (i = 0; i < SNMP_ARRAY_SZ; i++) {
1547 		free_percpu(ptr[i]);
1548 		ptr[i] = NULL;
1549 	}
1550 }
1551 EXPORT_SYMBOL_GPL(snmp_mib_free);
1552 
1553 #ifdef CONFIG_IP_MULTICAST
1554 static const struct net_protocol igmp_protocol = {
1555 	.handler =	igmp_rcv,
1556 	.netns_ok =	1,
1557 };
1558 #endif
1559 
1560 static const struct net_protocol tcp_protocol = {
1561 	.early_demux	=	tcp_v4_early_demux,
1562 	.handler	=	tcp_v4_rcv,
1563 	.err_handler	=	tcp_v4_err,
1564 	.no_policy	=	1,
1565 	.netns_ok	=	1,
1566 };
1567 
1568 static const struct net_offload tcp_offload = {
1569 	.callbacks = {
1570 		.gso_send_check	=	tcp_v4_gso_send_check,
1571 		.gso_segment	=	tcp_tso_segment,
1572 		.gro_receive	=	tcp4_gro_receive,
1573 		.gro_complete	=	tcp4_gro_complete,
1574 	},
1575 };
1576 
1577 static const struct net_protocol udp_protocol = {
1578 	.handler =	udp_rcv,
1579 	.err_handler =	udp_err,
1580 	.no_policy =	1,
1581 	.netns_ok =	1,
1582 };
1583 
1584 static const struct net_offload udp_offload = {
1585 	.callbacks = {
1586 		.gso_send_check = udp4_ufo_send_check,
1587 		.gso_segment = udp4_ufo_fragment,
1588 	},
1589 };
1590 
1591 static const struct net_protocol icmp_protocol = {
1592 	.handler =	icmp_rcv,
1593 	.err_handler =	ping_err,
1594 	.no_policy =	1,
1595 	.netns_ok =	1,
1596 };
1597 
1598 static __net_init int ipv4_mib_init_net(struct net *net)
1599 {
1600 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1601 			  sizeof(struct tcp_mib),
1602 			  __alignof__(struct tcp_mib)) < 0)
1603 		goto err_tcp_mib;
1604 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1605 			  sizeof(struct ipstats_mib),
1606 			  __alignof__(struct ipstats_mib)) < 0)
1607 		goto err_ip_mib;
1608 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1609 			  sizeof(struct linux_mib),
1610 			  __alignof__(struct linux_mib)) < 0)
1611 		goto err_net_mib;
1612 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1613 			  sizeof(struct udp_mib),
1614 			  __alignof__(struct udp_mib)) < 0)
1615 		goto err_udp_mib;
1616 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1617 			  sizeof(struct udp_mib),
1618 			  __alignof__(struct udp_mib)) < 0)
1619 		goto err_udplite_mib;
1620 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1621 			  sizeof(struct icmp_mib),
1622 			  __alignof__(struct icmp_mib)) < 0)
1623 		goto err_icmp_mib;
1624 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1625 					      GFP_KERNEL);
1626 	if (!net->mib.icmpmsg_statistics)
1627 		goto err_icmpmsg_mib;
1628 
1629 	tcp_mib_init(net);
1630 	return 0;
1631 
1632 err_icmpmsg_mib:
1633 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1634 err_icmp_mib:
1635 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1636 err_udplite_mib:
1637 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1638 err_udp_mib:
1639 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1640 err_net_mib:
1641 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1642 err_ip_mib:
1643 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1644 err_tcp_mib:
1645 	return -ENOMEM;
1646 }
1647 
1648 static __net_exit void ipv4_mib_exit_net(struct net *net)
1649 {
1650 	kfree(net->mib.icmpmsg_statistics);
1651 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1652 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1653 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1654 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1655 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1656 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1657 }
1658 
1659 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1660 	.init = ipv4_mib_init_net,
1661 	.exit = ipv4_mib_exit_net,
1662 };
1663 
1664 static int __init init_ipv4_mibs(void)
1665 {
1666 	return register_pernet_subsys(&ipv4_mib_ops);
1667 }
1668 
1669 static int ipv4_proc_init(void);
1670 
1671 /*
1672  *	IP protocol layer initialiser
1673  */
1674 
1675 static struct packet_offload ip_packet_offload __read_mostly = {
1676 	.type = cpu_to_be16(ETH_P_IP),
1677 	.callbacks = {
1678 		.gso_send_check = inet_gso_send_check,
1679 		.gso_segment = inet_gso_segment,
1680 		.gro_receive = inet_gro_receive,
1681 		.gro_complete = inet_gro_complete,
1682 	},
1683 };
1684 
1685 static int __init ipv4_offload_init(void)
1686 {
1687 	/*
1688 	 * Add offloads
1689 	 */
1690 	if (inet_add_offload(&udp_offload, IPPROTO_UDP) < 0)
1691 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1692 	if (inet_add_offload(&tcp_offload, IPPROTO_TCP) < 0)
1693 		pr_crit("%s: Cannot add TCP protocol offlaod\n", __func__);
1694 
1695 	dev_add_offload(&ip_packet_offload);
1696 	return 0;
1697 }
1698 
1699 fs_initcall(ipv4_offload_init);
1700 
1701 static struct packet_type ip_packet_type __read_mostly = {
1702 	.type = cpu_to_be16(ETH_P_IP),
1703 	.func = ip_rcv,
1704 };
1705 
1706 static int __init inet_init(void)
1707 {
1708 	struct sk_buff *dummy_skb;
1709 	struct inet_protosw *q;
1710 	struct list_head *r;
1711 	int rc = -EINVAL;
1712 
1713 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1714 
1715 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1716 	if (!sysctl_local_reserved_ports)
1717 		goto out;
1718 
1719 	rc = proto_register(&tcp_prot, 1);
1720 	if (rc)
1721 		goto out_free_reserved_ports;
1722 
1723 	rc = proto_register(&udp_prot, 1);
1724 	if (rc)
1725 		goto out_unregister_tcp_proto;
1726 
1727 	rc = proto_register(&raw_prot, 1);
1728 	if (rc)
1729 		goto out_unregister_udp_proto;
1730 
1731 	rc = proto_register(&ping_prot, 1);
1732 	if (rc)
1733 		goto out_unregister_raw_proto;
1734 
1735 	/*
1736 	 *	Tell SOCKET that we are alive...
1737 	 */
1738 
1739 	(void)sock_register(&inet_family_ops);
1740 
1741 #ifdef CONFIG_SYSCTL
1742 	ip_static_sysctl_init();
1743 #endif
1744 
1745 	tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;
1746 
1747 	/*
1748 	 *	Add all the base protocols.
1749 	 */
1750 
1751 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1752 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1753 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1754 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1755 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1756 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1757 #ifdef CONFIG_IP_MULTICAST
1758 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1759 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1760 #endif
1761 
1762 	/* Register the socket-side information for inet_create. */
1763 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1764 		INIT_LIST_HEAD(r);
1765 
1766 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1767 		inet_register_protosw(q);
1768 
1769 	/*
1770 	 *	Set the ARP module up
1771 	 */
1772 
1773 	arp_init();
1774 
1775 	/*
1776 	 *	Set the IP module up
1777 	 */
1778 
1779 	ip_init();
1780 
1781 	tcp_v4_init();
1782 
1783 	/* Setup TCP slab cache for open requests. */
1784 	tcp_init();
1785 
1786 	/* Setup UDP memory threshold */
1787 	udp_init();
1788 
1789 	/* Add UDP-Lite (RFC 3828) */
1790 	udplite4_register();
1791 
1792 	ping_init();
1793 
1794 	/*
1795 	 *	Set the ICMP layer up
1796 	 */
1797 
1798 	if (icmp_init() < 0)
1799 		panic("Failed to create the ICMP control socket.\n");
1800 
1801 	/*
1802 	 *	Initialise the multicast router
1803 	 */
1804 #if defined(CONFIG_IP_MROUTE)
1805 	if (ip_mr_init())
1806 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1807 #endif
1808 	/*
1809 	 *	Initialise per-cpu ipv4 mibs
1810 	 */
1811 
1812 	if (init_ipv4_mibs())
1813 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1814 
1815 	ipv4_proc_init();
1816 
1817 	ipfrag_init();
1818 
1819 	dev_add_pack(&ip_packet_type);
1820 
1821 	rc = 0;
1822 out:
1823 	return rc;
1824 out_unregister_raw_proto:
1825 	proto_unregister(&raw_prot);
1826 out_unregister_udp_proto:
1827 	proto_unregister(&udp_prot);
1828 out_unregister_tcp_proto:
1829 	proto_unregister(&tcp_prot);
1830 out_free_reserved_ports:
1831 	kfree(sysctl_local_reserved_ports);
1832 	goto out;
1833 }
1834 
1835 fs_initcall(inet_init);
1836 
1837 /* ------------------------------------------------------------------------ */
1838 
1839 #ifdef CONFIG_PROC_FS
1840 static int __init ipv4_proc_init(void)
1841 {
1842 	int rc = 0;
1843 
1844 	if (raw_proc_init())
1845 		goto out_raw;
1846 	if (tcp4_proc_init())
1847 		goto out_tcp;
1848 	if (udp4_proc_init())
1849 		goto out_udp;
1850 	if (ping_proc_init())
1851 		goto out_ping;
1852 	if (ip_misc_proc_init())
1853 		goto out_misc;
1854 out:
1855 	return rc;
1856 out_misc:
1857 	ping_proc_exit();
1858 out_ping:
1859 	udp4_proc_exit();
1860 out_udp:
1861 	tcp4_proc_exit();
1862 out_tcp:
1863 	raw_proc_exit();
1864 out_raw:
1865 	rc = -ENOMEM;
1866 	goto out;
1867 }
1868 
1869 #else /* CONFIG_PROC_FS */
1870 static int __init ipv4_proc_init(void)
1871 {
1872 	return 0;
1873 }
1874 #endif /* CONFIG_PROC_FS */
1875 
1876 MODULE_ALIAS_NETPROTO(PF_INET);
1877 
1878