xref: /openbmc/linux/net/ipv4/af_inet.c (revision 8e9356c6)
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 	char answer_no_check;
258 	int try_loading_module = 0;
259 	int err;
260 
261 	sock->state = SS_UNCONNECTED;
262 
263 	/* Look for the requested type/protocol pair. */
264 lookup_protocol:
265 	err = -ESOCKTNOSUPPORT;
266 	rcu_read_lock();
267 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
268 
269 		err = 0;
270 		/* Check the non-wild match. */
271 		if (protocol == answer->protocol) {
272 			if (protocol != IPPROTO_IP)
273 				break;
274 		} else {
275 			/* Check for the two wild cases. */
276 			if (IPPROTO_IP == protocol) {
277 				protocol = answer->protocol;
278 				break;
279 			}
280 			if (IPPROTO_IP == answer->protocol)
281 				break;
282 		}
283 		err = -EPROTONOSUPPORT;
284 	}
285 
286 	if (unlikely(err)) {
287 		if (try_loading_module < 2) {
288 			rcu_read_unlock();
289 			/*
290 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
291 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
292 			 */
293 			if (++try_loading_module == 1)
294 				request_module("net-pf-%d-proto-%d-type-%d",
295 					       PF_INET, protocol, sock->type);
296 			/*
297 			 * Fall back to generic, e.g. net-pf-2-proto-132
298 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
299 			 */
300 			else
301 				request_module("net-pf-%d-proto-%d",
302 					       PF_INET, protocol);
303 			goto lookup_protocol;
304 		} else
305 			goto out_rcu_unlock;
306 	}
307 
308 	err = -EPERM;
309 	if (sock->type == SOCK_RAW && !kern &&
310 	    !ns_capable(net->user_ns, CAP_NET_RAW))
311 		goto out_rcu_unlock;
312 
313 	sock->ops = answer->ops;
314 	answer_prot = answer->prot;
315 	answer_no_check = answer->no_check;
316 	answer_flags = answer->flags;
317 	rcu_read_unlock();
318 
319 	WARN_ON(answer_prot->slab == NULL);
320 
321 	err = -ENOBUFS;
322 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
323 	if (sk == NULL)
324 		goto out;
325 
326 	err = 0;
327 	sk->sk_no_check = answer_no_check;
328 	if (INET_PROTOSW_REUSE & answer_flags)
329 		sk->sk_reuse = SK_CAN_REUSE;
330 
331 	inet = inet_sk(sk);
332 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
333 
334 	inet->nodefrag = 0;
335 
336 	if (SOCK_RAW == sock->type) {
337 		inet->inet_num = protocol;
338 		if (IPPROTO_RAW == protocol)
339 			inet->hdrincl = 1;
340 	}
341 
342 	if (net->ipv4.sysctl_ip_no_pmtu_disc)
343 		inet->pmtudisc = IP_PMTUDISC_DONT;
344 	else
345 		inet->pmtudisc = IP_PMTUDISC_WANT;
346 
347 	inet->inet_id = 0;
348 
349 	sock_init_data(sock, sk);
350 
351 	sk->sk_destruct	   = inet_sock_destruct;
352 	sk->sk_protocol	   = protocol;
353 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
354 
355 	inet->uc_ttl	= -1;
356 	inet->mc_loop	= 1;
357 	inet->mc_ttl	= 1;
358 	inet->mc_all	= 1;
359 	inet->mc_index	= 0;
360 	inet->mc_list	= NULL;
361 	inet->rcv_tos	= 0;
362 
363 	sk_refcnt_debug_inc(sk);
364 
365 	if (inet->inet_num) {
366 		/* It assumes that any protocol which allows
367 		 * the user to assign a number at socket
368 		 * creation time automatically
369 		 * shares.
370 		 */
371 		inet->inet_sport = htons(inet->inet_num);
372 		/* Add to protocol hash chains. */
373 		sk->sk_prot->hash(sk);
374 	}
375 
376 	if (sk->sk_prot->init) {
377 		err = sk->sk_prot->init(sk);
378 		if (err)
379 			sk_common_release(sk);
380 	}
381 out:
382 	return err;
383 out_rcu_unlock:
384 	rcu_read_unlock();
385 	goto out;
386 }
387 
388 
389 /*
390  *	The peer socket should always be NULL (or else). When we call this
391  *	function we are destroying the object and from then on nobody
392  *	should refer to it.
393  */
394 int inet_release(struct socket *sock)
395 {
396 	struct sock *sk = sock->sk;
397 
398 	if (sk) {
399 		long timeout;
400 
401 		sock_rps_reset_flow(sk);
402 
403 		/* Applications forget to leave groups before exiting */
404 		ip_mc_drop_socket(sk);
405 
406 		/* If linger is set, we don't return until the close
407 		 * is complete.  Otherwise we return immediately. The
408 		 * actually closing is done the same either way.
409 		 *
410 		 * If the close is due to the process exiting, we never
411 		 * linger..
412 		 */
413 		timeout = 0;
414 		if (sock_flag(sk, SOCK_LINGER) &&
415 		    !(current->flags & PF_EXITING))
416 			timeout = sk->sk_lingertime;
417 		sock->sk = NULL;
418 		sk->sk_prot->close(sk, timeout);
419 	}
420 	return 0;
421 }
422 EXPORT_SYMBOL(inet_release);
423 
424 /* It is off by default, see below. */
425 int sysctl_ip_nonlocal_bind __read_mostly;
426 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
427 
428 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
429 {
430 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
431 	struct sock *sk = sock->sk;
432 	struct inet_sock *inet = inet_sk(sk);
433 	struct net *net = sock_net(sk);
434 	unsigned short snum;
435 	int chk_addr_ret;
436 	int err;
437 
438 	/* If the socket has its own bind function then use it. (RAW) */
439 	if (sk->sk_prot->bind) {
440 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
441 		goto out;
442 	}
443 	err = -EINVAL;
444 	if (addr_len < sizeof(struct sockaddr_in))
445 		goto out;
446 
447 	if (addr->sin_family != AF_INET) {
448 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
449 		 * only if s_addr is INADDR_ANY.
450 		 */
451 		err = -EAFNOSUPPORT;
452 		if (addr->sin_family != AF_UNSPEC ||
453 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
454 			goto out;
455 	}
456 
457 	chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
458 
459 	/* Not specified by any standard per-se, however it breaks too
460 	 * many applications when removed.  It is unfortunate since
461 	 * allowing applications to make a non-local bind solves
462 	 * several problems with systems using dynamic addressing.
463 	 * (ie. your servers still start up even if your ISDN link
464 	 *  is temporarily down)
465 	 */
466 	err = -EADDRNOTAVAIL;
467 	if (!sysctl_ip_nonlocal_bind &&
468 	    !(inet->freebind || inet->transparent) &&
469 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
470 	    chk_addr_ret != RTN_LOCAL &&
471 	    chk_addr_ret != RTN_MULTICAST &&
472 	    chk_addr_ret != RTN_BROADCAST)
473 		goto out;
474 
475 	snum = ntohs(addr->sin_port);
476 	err = -EACCES;
477 	if (snum && snum < PROT_SOCK &&
478 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
479 		goto out;
480 
481 	/*      We keep a pair of addresses. rcv_saddr is the one
482 	 *      used by hash lookups, and saddr is used for transmit.
483 	 *
484 	 *      In the BSD API these are the same except where it
485 	 *      would be illegal to use them (multicast/broadcast) in
486 	 *      which case the sending device address is used.
487 	 */
488 	lock_sock(sk);
489 
490 	/* Check these errors (active socket, double bind). */
491 	err = -EINVAL;
492 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
493 		goto out_release_sock;
494 
495 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
496 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
497 		inet->inet_saddr = 0;  /* Use device */
498 
499 	/* Make sure we are allowed to bind here. */
500 	if (sk->sk_prot->get_port(sk, snum)) {
501 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
502 		err = -EADDRINUSE;
503 		goto out_release_sock;
504 	}
505 
506 	if (inet->inet_rcv_saddr)
507 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
508 	if (snum)
509 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
510 	inet->inet_sport = htons(inet->inet_num);
511 	inet->inet_daddr = 0;
512 	inet->inet_dport = 0;
513 	sk_dst_reset(sk);
514 	err = 0;
515 out_release_sock:
516 	release_sock(sk);
517 out:
518 	return err;
519 }
520 EXPORT_SYMBOL(inet_bind);
521 
522 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
523 		       int addr_len, int flags)
524 {
525 	struct sock *sk = sock->sk;
526 
527 	if (addr_len < sizeof(uaddr->sa_family))
528 		return -EINVAL;
529 	if (uaddr->sa_family == AF_UNSPEC)
530 		return sk->sk_prot->disconnect(sk, flags);
531 
532 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
533 		return -EAGAIN;
534 	return sk->sk_prot->connect(sk, uaddr, addr_len);
535 }
536 EXPORT_SYMBOL(inet_dgram_connect);
537 
538 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
539 {
540 	DEFINE_WAIT(wait);
541 
542 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
543 	sk->sk_write_pending += writebias;
544 
545 	/* Basic assumption: if someone sets sk->sk_err, he _must_
546 	 * change state of the socket from TCP_SYN_*.
547 	 * Connect() does not allow to get error notifications
548 	 * without closing the socket.
549 	 */
550 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
551 		release_sock(sk);
552 		timeo = schedule_timeout(timeo);
553 		lock_sock(sk);
554 		if (signal_pending(current) || !timeo)
555 			break;
556 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
557 	}
558 	finish_wait(sk_sleep(sk), &wait);
559 	sk->sk_write_pending -= writebias;
560 	return timeo;
561 }
562 
563 /*
564  *	Connect to a remote host. There is regrettably still a little
565  *	TCP 'magic' in here.
566  */
567 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
568 			  int addr_len, int flags)
569 {
570 	struct sock *sk = sock->sk;
571 	int err;
572 	long timeo;
573 
574 	if (addr_len < sizeof(uaddr->sa_family))
575 		return -EINVAL;
576 
577 	if (uaddr->sa_family == AF_UNSPEC) {
578 		err = sk->sk_prot->disconnect(sk, flags);
579 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
580 		goto out;
581 	}
582 
583 	switch (sock->state) {
584 	default:
585 		err = -EINVAL;
586 		goto out;
587 	case SS_CONNECTED:
588 		err = -EISCONN;
589 		goto out;
590 	case SS_CONNECTING:
591 		err = -EALREADY;
592 		/* Fall out of switch with err, set for this state */
593 		break;
594 	case SS_UNCONNECTED:
595 		err = -EISCONN;
596 		if (sk->sk_state != TCP_CLOSE)
597 			goto out;
598 
599 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
600 		if (err < 0)
601 			goto out;
602 
603 		sock->state = SS_CONNECTING;
604 
605 		/* Just entered SS_CONNECTING state; the only
606 		 * difference is that return value in non-blocking
607 		 * case is EINPROGRESS, rather than EALREADY.
608 		 */
609 		err = -EINPROGRESS;
610 		break;
611 	}
612 
613 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
614 
615 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
616 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
617 				tcp_sk(sk)->fastopen_req &&
618 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
619 
620 		/* Error code is set above */
621 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
622 			goto out;
623 
624 		err = sock_intr_errno(timeo);
625 		if (signal_pending(current))
626 			goto out;
627 	}
628 
629 	/* Connection was closed by RST, timeout, ICMP error
630 	 * or another process disconnected us.
631 	 */
632 	if (sk->sk_state == TCP_CLOSE)
633 		goto sock_error;
634 
635 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
636 	 * and error was received after socket entered established state.
637 	 * Hence, it is handled normally after connect() return successfully.
638 	 */
639 
640 	sock->state = SS_CONNECTED;
641 	err = 0;
642 out:
643 	return err;
644 
645 sock_error:
646 	err = sock_error(sk) ? : -ECONNABORTED;
647 	sock->state = SS_UNCONNECTED;
648 	if (sk->sk_prot->disconnect(sk, flags))
649 		sock->state = SS_DISCONNECTING;
650 	goto out;
651 }
652 EXPORT_SYMBOL(__inet_stream_connect);
653 
654 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
655 			int addr_len, int flags)
656 {
657 	int err;
658 
659 	lock_sock(sock->sk);
660 	err = __inet_stream_connect(sock, uaddr, addr_len, flags);
661 	release_sock(sock->sk);
662 	return err;
663 }
664 EXPORT_SYMBOL(inet_stream_connect);
665 
666 /*
667  *	Accept a pending connection. The TCP layer now gives BSD semantics.
668  */
669 
670 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
671 {
672 	struct sock *sk1 = sock->sk;
673 	int err = -EINVAL;
674 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
675 
676 	if (!sk2)
677 		goto do_err;
678 
679 	lock_sock(sk2);
680 
681 	sock_rps_record_flow(sk2);
682 	WARN_ON(!((1 << sk2->sk_state) &
683 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
684 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
685 
686 	sock_graft(sk2, newsock);
687 
688 	newsock->state = SS_CONNECTED;
689 	err = 0;
690 	release_sock(sk2);
691 do_err:
692 	return err;
693 }
694 EXPORT_SYMBOL(inet_accept);
695 
696 
697 /*
698  *	This does both peername and sockname.
699  */
700 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
701 			int *uaddr_len, int peer)
702 {
703 	struct sock *sk		= sock->sk;
704 	struct inet_sock *inet	= inet_sk(sk);
705 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
706 
707 	sin->sin_family = AF_INET;
708 	if (peer) {
709 		if (!inet->inet_dport ||
710 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
711 		     peer == 1))
712 			return -ENOTCONN;
713 		sin->sin_port = inet->inet_dport;
714 		sin->sin_addr.s_addr = inet->inet_daddr;
715 	} else {
716 		__be32 addr = inet->inet_rcv_saddr;
717 		if (!addr)
718 			addr = inet->inet_saddr;
719 		sin->sin_port = inet->inet_sport;
720 		sin->sin_addr.s_addr = addr;
721 	}
722 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
723 	*uaddr_len = sizeof(*sin);
724 	return 0;
725 }
726 EXPORT_SYMBOL(inet_getname);
727 
728 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
729 		 size_t size)
730 {
731 	struct sock *sk = sock->sk;
732 
733 	sock_rps_record_flow(sk);
734 
735 	/* We may need to bind the socket. */
736 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
737 	    inet_autobind(sk))
738 		return -EAGAIN;
739 
740 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
741 }
742 EXPORT_SYMBOL(inet_sendmsg);
743 
744 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
745 		      size_t size, int flags)
746 {
747 	struct sock *sk = sock->sk;
748 
749 	sock_rps_record_flow(sk);
750 
751 	/* We may need to bind the socket. */
752 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
753 	    inet_autobind(sk))
754 		return -EAGAIN;
755 
756 	if (sk->sk_prot->sendpage)
757 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
758 	return sock_no_sendpage(sock, page, offset, size, flags);
759 }
760 EXPORT_SYMBOL(inet_sendpage);
761 
762 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
763 		 size_t size, int flags)
764 {
765 	struct sock *sk = sock->sk;
766 	int addr_len = 0;
767 	int err;
768 
769 	sock_rps_record_flow(sk);
770 
771 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
772 				   flags & ~MSG_DONTWAIT, &addr_len);
773 	if (err >= 0)
774 		msg->msg_namelen = addr_len;
775 	return err;
776 }
777 EXPORT_SYMBOL(inet_recvmsg);
778 
779 int inet_shutdown(struct socket *sock, int how)
780 {
781 	struct sock *sk = sock->sk;
782 	int err = 0;
783 
784 	/* This should really check to make sure
785 	 * the socket is a TCP socket. (WHY AC...)
786 	 */
787 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
788 		       1->2 bit 2 snds.
789 		       2->3 */
790 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
791 		return -EINVAL;
792 
793 	lock_sock(sk);
794 	if (sock->state == SS_CONNECTING) {
795 		if ((1 << sk->sk_state) &
796 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
797 			sock->state = SS_DISCONNECTING;
798 		else
799 			sock->state = SS_CONNECTED;
800 	}
801 
802 	switch (sk->sk_state) {
803 	case TCP_CLOSE:
804 		err = -ENOTCONN;
805 		/* Hack to wake up other listeners, who can poll for
806 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
807 	default:
808 		sk->sk_shutdown |= how;
809 		if (sk->sk_prot->shutdown)
810 			sk->sk_prot->shutdown(sk, how);
811 		break;
812 
813 	/* Remaining two branches are temporary solution for missing
814 	 * close() in multithreaded environment. It is _not_ a good idea,
815 	 * but we have no choice until close() is repaired at VFS level.
816 	 */
817 	case TCP_LISTEN:
818 		if (!(how & RCV_SHUTDOWN))
819 			break;
820 		/* Fall through */
821 	case TCP_SYN_SENT:
822 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
823 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
824 		break;
825 	}
826 
827 	/* Wake up anyone sleeping in poll. */
828 	sk->sk_state_change(sk);
829 	release_sock(sk);
830 	return err;
831 }
832 EXPORT_SYMBOL(inet_shutdown);
833 
834 /*
835  *	ioctl() calls you can issue on an INET socket. Most of these are
836  *	device configuration and stuff and very rarely used. Some ioctls
837  *	pass on to the socket itself.
838  *
839  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
840  *	loads the devconfigure module does its configuring and unloads it.
841  *	There's a good 20K of config code hanging around the kernel.
842  */
843 
844 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
845 {
846 	struct sock *sk = sock->sk;
847 	int err = 0;
848 	struct net *net = sock_net(sk);
849 
850 	switch (cmd) {
851 	case SIOCGSTAMP:
852 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
853 		break;
854 	case SIOCGSTAMPNS:
855 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
856 		break;
857 	case SIOCADDRT:
858 	case SIOCDELRT:
859 	case SIOCRTMSG:
860 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
861 		break;
862 	case SIOCDARP:
863 	case SIOCGARP:
864 	case SIOCSARP:
865 		err = arp_ioctl(net, cmd, (void __user *)arg);
866 		break;
867 	case SIOCGIFADDR:
868 	case SIOCSIFADDR:
869 	case SIOCGIFBRDADDR:
870 	case SIOCSIFBRDADDR:
871 	case SIOCGIFNETMASK:
872 	case SIOCSIFNETMASK:
873 	case SIOCGIFDSTADDR:
874 	case SIOCSIFDSTADDR:
875 	case SIOCSIFPFLAGS:
876 	case SIOCGIFPFLAGS:
877 	case SIOCSIFFLAGS:
878 		err = devinet_ioctl(net, cmd, (void __user *)arg);
879 		break;
880 	default:
881 		if (sk->sk_prot->ioctl)
882 			err = sk->sk_prot->ioctl(sk, cmd, arg);
883 		else
884 			err = -ENOIOCTLCMD;
885 		break;
886 	}
887 	return err;
888 }
889 EXPORT_SYMBOL(inet_ioctl);
890 
891 #ifdef CONFIG_COMPAT
892 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
893 {
894 	struct sock *sk = sock->sk;
895 	int err = -ENOIOCTLCMD;
896 
897 	if (sk->sk_prot->compat_ioctl)
898 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
899 
900 	return err;
901 }
902 #endif
903 
904 const struct proto_ops inet_stream_ops = {
905 	.family		   = PF_INET,
906 	.owner		   = THIS_MODULE,
907 	.release	   = inet_release,
908 	.bind		   = inet_bind,
909 	.connect	   = inet_stream_connect,
910 	.socketpair	   = sock_no_socketpair,
911 	.accept		   = inet_accept,
912 	.getname	   = inet_getname,
913 	.poll		   = tcp_poll,
914 	.ioctl		   = inet_ioctl,
915 	.listen		   = inet_listen,
916 	.shutdown	   = inet_shutdown,
917 	.setsockopt	   = sock_common_setsockopt,
918 	.getsockopt	   = sock_common_getsockopt,
919 	.sendmsg	   = inet_sendmsg,
920 	.recvmsg	   = inet_recvmsg,
921 	.mmap		   = sock_no_mmap,
922 	.sendpage	   = inet_sendpage,
923 	.splice_read	   = tcp_splice_read,
924 #ifdef CONFIG_COMPAT
925 	.compat_setsockopt = compat_sock_common_setsockopt,
926 	.compat_getsockopt = compat_sock_common_getsockopt,
927 	.compat_ioctl	   = inet_compat_ioctl,
928 #endif
929 };
930 EXPORT_SYMBOL(inet_stream_ops);
931 
932 const struct proto_ops inet_dgram_ops = {
933 	.family		   = PF_INET,
934 	.owner		   = THIS_MODULE,
935 	.release	   = inet_release,
936 	.bind		   = inet_bind,
937 	.connect	   = inet_dgram_connect,
938 	.socketpair	   = sock_no_socketpair,
939 	.accept		   = sock_no_accept,
940 	.getname	   = inet_getname,
941 	.poll		   = udp_poll,
942 	.ioctl		   = inet_ioctl,
943 	.listen		   = sock_no_listen,
944 	.shutdown	   = inet_shutdown,
945 	.setsockopt	   = sock_common_setsockopt,
946 	.getsockopt	   = sock_common_getsockopt,
947 	.sendmsg	   = inet_sendmsg,
948 	.recvmsg	   = inet_recvmsg,
949 	.mmap		   = sock_no_mmap,
950 	.sendpage	   = inet_sendpage,
951 #ifdef CONFIG_COMPAT
952 	.compat_setsockopt = compat_sock_common_setsockopt,
953 	.compat_getsockopt = compat_sock_common_getsockopt,
954 	.compat_ioctl	   = inet_compat_ioctl,
955 #endif
956 };
957 EXPORT_SYMBOL(inet_dgram_ops);
958 
959 /*
960  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
961  * udp_poll
962  */
963 static const struct proto_ops inet_sockraw_ops = {
964 	.family		   = PF_INET,
965 	.owner		   = THIS_MODULE,
966 	.release	   = inet_release,
967 	.bind		   = inet_bind,
968 	.connect	   = inet_dgram_connect,
969 	.socketpair	   = sock_no_socketpair,
970 	.accept		   = sock_no_accept,
971 	.getname	   = inet_getname,
972 	.poll		   = datagram_poll,
973 	.ioctl		   = inet_ioctl,
974 	.listen		   = sock_no_listen,
975 	.shutdown	   = inet_shutdown,
976 	.setsockopt	   = sock_common_setsockopt,
977 	.getsockopt	   = sock_common_getsockopt,
978 	.sendmsg	   = inet_sendmsg,
979 	.recvmsg	   = inet_recvmsg,
980 	.mmap		   = sock_no_mmap,
981 	.sendpage	   = inet_sendpage,
982 #ifdef CONFIG_COMPAT
983 	.compat_setsockopt = compat_sock_common_setsockopt,
984 	.compat_getsockopt = compat_sock_common_getsockopt,
985 	.compat_ioctl	   = inet_compat_ioctl,
986 #endif
987 };
988 
989 static const struct net_proto_family inet_family_ops = {
990 	.family = PF_INET,
991 	.create = inet_create,
992 	.owner	= THIS_MODULE,
993 };
994 
995 /* Upon startup we insert all the elements in inetsw_array[] into
996  * the linked list inetsw.
997  */
998 static struct inet_protosw inetsw_array[] =
999 {
1000 	{
1001 		.type =       SOCK_STREAM,
1002 		.protocol =   IPPROTO_TCP,
1003 		.prot =       &tcp_prot,
1004 		.ops =        &inet_stream_ops,
1005 		.no_check =   0,
1006 		.flags =      INET_PROTOSW_PERMANENT |
1007 			      INET_PROTOSW_ICSK,
1008 	},
1009 
1010 	{
1011 		.type =       SOCK_DGRAM,
1012 		.protocol =   IPPROTO_UDP,
1013 		.prot =       &udp_prot,
1014 		.ops =        &inet_dgram_ops,
1015 		.no_check =   UDP_CSUM_DEFAULT,
1016 		.flags =      INET_PROTOSW_PERMANENT,
1017        },
1018 
1019        {
1020 		.type =       SOCK_DGRAM,
1021 		.protocol =   IPPROTO_ICMP,
1022 		.prot =       &ping_prot,
1023 		.ops =        &inet_dgram_ops,
1024 		.no_check =   UDP_CSUM_DEFAULT,
1025 		.flags =      INET_PROTOSW_REUSE,
1026        },
1027 
1028        {
1029 	       .type =       SOCK_RAW,
1030 	       .protocol =   IPPROTO_IP,	/* wild card */
1031 	       .prot =       &raw_prot,
1032 	       .ops =        &inet_sockraw_ops,
1033 	       .no_check =   UDP_CSUM_DEFAULT,
1034 	       .flags =      INET_PROTOSW_REUSE,
1035        }
1036 };
1037 
1038 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1039 
1040 void inet_register_protosw(struct inet_protosw *p)
1041 {
1042 	struct list_head *lh;
1043 	struct inet_protosw *answer;
1044 	int protocol = p->protocol;
1045 	struct list_head *last_perm;
1046 
1047 	spin_lock_bh(&inetsw_lock);
1048 
1049 	if (p->type >= SOCK_MAX)
1050 		goto out_illegal;
1051 
1052 	/* If we are trying to override a permanent protocol, bail. */
1053 	answer = NULL;
1054 	last_perm = &inetsw[p->type];
1055 	list_for_each(lh, &inetsw[p->type]) {
1056 		answer = list_entry(lh, struct inet_protosw, list);
1057 
1058 		/* Check only the non-wild match. */
1059 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1060 			if (protocol == answer->protocol)
1061 				break;
1062 			last_perm = lh;
1063 		}
1064 
1065 		answer = NULL;
1066 	}
1067 	if (answer)
1068 		goto out_permanent;
1069 
1070 	/* Add the new entry after the last permanent entry if any, so that
1071 	 * the new entry does not override a permanent entry when matched with
1072 	 * a wild-card protocol. But it is allowed to override any existing
1073 	 * non-permanent entry.  This means that when we remove this entry, the
1074 	 * system automatically returns to the old behavior.
1075 	 */
1076 	list_add_rcu(&p->list, last_perm);
1077 out:
1078 	spin_unlock_bh(&inetsw_lock);
1079 
1080 	return;
1081 
1082 out_permanent:
1083 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1084 	goto out;
1085 
1086 out_illegal:
1087 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1088 	       p->type);
1089 	goto out;
1090 }
1091 EXPORT_SYMBOL(inet_register_protosw);
1092 
1093 void inet_unregister_protosw(struct inet_protosw *p)
1094 {
1095 	if (INET_PROTOSW_PERMANENT & p->flags) {
1096 		pr_err("Attempt to unregister permanent protocol %d\n",
1097 		       p->protocol);
1098 	} else {
1099 		spin_lock_bh(&inetsw_lock);
1100 		list_del_rcu(&p->list);
1101 		spin_unlock_bh(&inetsw_lock);
1102 
1103 		synchronize_net();
1104 	}
1105 }
1106 EXPORT_SYMBOL(inet_unregister_protosw);
1107 
1108 /*
1109  *      Shall we try to damage output packets if routing dev changes?
1110  */
1111 
1112 int sysctl_ip_dynaddr __read_mostly;
1113 
1114 static int inet_sk_reselect_saddr(struct sock *sk)
1115 {
1116 	struct inet_sock *inet = inet_sk(sk);
1117 	__be32 old_saddr = inet->inet_saddr;
1118 	__be32 daddr = inet->inet_daddr;
1119 	struct flowi4 *fl4;
1120 	struct rtable *rt;
1121 	__be32 new_saddr;
1122 	struct ip_options_rcu *inet_opt;
1123 
1124 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1125 					     sock_owned_by_user(sk));
1126 	if (inet_opt && inet_opt->opt.srr)
1127 		daddr = inet_opt->opt.faddr;
1128 
1129 	/* Query new route. */
1130 	fl4 = &inet->cork.fl.u.ip4;
1131 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1132 			      sk->sk_bound_dev_if, sk->sk_protocol,
1133 			      inet->inet_sport, inet->inet_dport, sk);
1134 	if (IS_ERR(rt))
1135 		return PTR_ERR(rt);
1136 
1137 	sk_setup_caps(sk, &rt->dst);
1138 
1139 	new_saddr = fl4->saddr;
1140 
1141 	if (new_saddr == old_saddr)
1142 		return 0;
1143 
1144 	if (sysctl_ip_dynaddr > 1) {
1145 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1146 			__func__, &old_saddr, &new_saddr);
1147 	}
1148 
1149 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1150 
1151 	/*
1152 	 * XXX The only one ugly spot where we need to
1153 	 * XXX really change the sockets identity after
1154 	 * XXX it has entered the hashes. -DaveM
1155 	 *
1156 	 * Besides that, it does not check for connection
1157 	 * uniqueness. Wait for troubles.
1158 	 */
1159 	__sk_prot_rehash(sk);
1160 	return 0;
1161 }
1162 
1163 int inet_sk_rebuild_header(struct sock *sk)
1164 {
1165 	struct inet_sock *inet = inet_sk(sk);
1166 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1167 	__be32 daddr;
1168 	struct ip_options_rcu *inet_opt;
1169 	struct flowi4 *fl4;
1170 	int err;
1171 
1172 	/* Route is OK, nothing to do. */
1173 	if (rt)
1174 		return 0;
1175 
1176 	/* Reroute. */
1177 	rcu_read_lock();
1178 	inet_opt = rcu_dereference(inet->inet_opt);
1179 	daddr = inet->inet_daddr;
1180 	if (inet_opt && inet_opt->opt.srr)
1181 		daddr = inet_opt->opt.faddr;
1182 	rcu_read_unlock();
1183 	fl4 = &inet->cork.fl.u.ip4;
1184 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1185 				   inet->inet_dport, inet->inet_sport,
1186 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1187 				   sk->sk_bound_dev_if);
1188 	if (!IS_ERR(rt)) {
1189 		err = 0;
1190 		sk_setup_caps(sk, &rt->dst);
1191 	} else {
1192 		err = PTR_ERR(rt);
1193 
1194 		/* Routing failed... */
1195 		sk->sk_route_caps = 0;
1196 		/*
1197 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1198 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1199 		 */
1200 		if (!sysctl_ip_dynaddr ||
1201 		    sk->sk_state != TCP_SYN_SENT ||
1202 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1203 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1204 			sk->sk_err_soft = -err;
1205 	}
1206 
1207 	return err;
1208 }
1209 EXPORT_SYMBOL(inet_sk_rebuild_header);
1210 
1211 static int inet_gso_send_check(struct sk_buff *skb)
1212 {
1213 	const struct net_offload *ops;
1214 	const struct iphdr *iph;
1215 	int proto;
1216 	int ihl;
1217 	int err = -EINVAL;
1218 
1219 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1220 		goto out;
1221 
1222 	iph = ip_hdr(skb);
1223 	ihl = iph->ihl * 4;
1224 	if (ihl < sizeof(*iph))
1225 		goto out;
1226 
1227 	proto = iph->protocol;
1228 
1229 	/* Warning: after this point, iph might be no longer valid */
1230 	if (unlikely(!pskb_may_pull(skb, ihl)))
1231 		goto out;
1232 	__skb_pull(skb, ihl);
1233 
1234 	skb_reset_transport_header(skb);
1235 	err = -EPROTONOSUPPORT;
1236 
1237 	ops = rcu_dereference(inet_offloads[proto]);
1238 	if (likely(ops && ops->callbacks.gso_send_check))
1239 		err = ops->callbacks.gso_send_check(skb);
1240 
1241 out:
1242 	return err;
1243 }
1244 
1245 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1246 					netdev_features_t features)
1247 {
1248 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1249 	const struct net_offload *ops;
1250 	unsigned int offset = 0;
1251 	bool udpfrag, encap;
1252 	struct iphdr *iph;
1253 	int proto;
1254 	int nhoff;
1255 	int ihl;
1256 	int id;
1257 
1258 	if (unlikely(skb_shinfo(skb)->gso_type &
1259 		     ~(SKB_GSO_TCPV4 |
1260 		       SKB_GSO_UDP |
1261 		       SKB_GSO_DODGY |
1262 		       SKB_GSO_TCP_ECN |
1263 		       SKB_GSO_GRE |
1264 		       SKB_GSO_IPIP |
1265 		       SKB_GSO_SIT |
1266 		       SKB_GSO_TCPV6 |
1267 		       SKB_GSO_UDP_TUNNEL |
1268 		       SKB_GSO_MPLS |
1269 		       0)))
1270 		goto out;
1271 
1272 	skb_reset_network_header(skb);
1273 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1274 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1275 		goto out;
1276 
1277 	iph = ip_hdr(skb);
1278 	ihl = iph->ihl * 4;
1279 	if (ihl < sizeof(*iph))
1280 		goto out;
1281 
1282 	id = ntohs(iph->id);
1283 	proto = iph->protocol;
1284 
1285 	/* Warning: after this point, iph might be no longer valid */
1286 	if (unlikely(!pskb_may_pull(skb, ihl)))
1287 		goto out;
1288 	__skb_pull(skb, ihl);
1289 
1290 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1291 	if (encap)
1292 		features = skb->dev->hw_enc_features & netif_skb_features(skb);
1293 	SKB_GSO_CB(skb)->encap_level += ihl;
1294 
1295 	skb_reset_transport_header(skb);
1296 
1297 	segs = ERR_PTR(-EPROTONOSUPPORT);
1298 
1299 	/* Note : following gso_segment() might change skb->encapsulation */
1300 	udpfrag = !skb->encapsulation && proto == IPPROTO_UDP;
1301 
1302 	ops = rcu_dereference(inet_offloads[proto]);
1303 	if (likely(ops && ops->callbacks.gso_segment))
1304 		segs = ops->callbacks.gso_segment(skb, features);
1305 
1306 	if (IS_ERR_OR_NULL(segs))
1307 		goto out;
1308 
1309 	skb = segs;
1310 	do {
1311 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1312 		if (udpfrag) {
1313 			iph->id = htons(id);
1314 			iph->frag_off = htons(offset >> 3);
1315 			if (skb->next != NULL)
1316 				iph->frag_off |= htons(IP_MF);
1317 			offset += skb->len - nhoff - ihl;
1318 		} else {
1319 			iph->id = htons(id++);
1320 		}
1321 		iph->tot_len = htons(skb->len - nhoff);
1322 		ip_send_check(iph);
1323 		if (encap)
1324 			skb_reset_inner_headers(skb);
1325 		skb->network_header = (u8 *)iph - skb->head;
1326 	} while ((skb = skb->next));
1327 
1328 out:
1329 	return segs;
1330 }
1331 
1332 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1333 					 struct sk_buff *skb)
1334 {
1335 	const struct net_offload *ops;
1336 	struct sk_buff **pp = NULL;
1337 	struct sk_buff *p;
1338 	const struct iphdr *iph;
1339 	unsigned int hlen;
1340 	unsigned int off;
1341 	unsigned int id;
1342 	int flush = 1;
1343 	int proto;
1344 
1345 	off = skb_gro_offset(skb);
1346 	hlen = off + sizeof(*iph);
1347 	iph = skb_gro_header_fast(skb, off);
1348 	if (skb_gro_header_hard(skb, hlen)) {
1349 		iph = skb_gro_header_slow(skb, hlen, off);
1350 		if (unlikely(!iph))
1351 			goto out;
1352 	}
1353 
1354 	proto = iph->protocol;
1355 
1356 	rcu_read_lock();
1357 	ops = rcu_dereference(inet_offloads[proto]);
1358 	if (!ops || !ops->callbacks.gro_receive)
1359 		goto out_unlock;
1360 
1361 	if (*(u8 *)iph != 0x45)
1362 		goto out_unlock;
1363 
1364 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1365 		goto out_unlock;
1366 
1367 	id = ntohl(*(__be32 *)&iph->id);
1368 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1369 	id >>= 16;
1370 
1371 	for (p = *head; p; p = p->next) {
1372 		struct iphdr *iph2;
1373 
1374 		if (!NAPI_GRO_CB(p)->same_flow)
1375 			continue;
1376 
1377 		iph2 = (struct iphdr *)(p->data + off);
1378 		/* The above works because, with the exception of the top
1379 		 * (inner most) layer, we only aggregate pkts with the same
1380 		 * hdr length so all the hdrs we'll need to verify will start
1381 		 * at the same offset.
1382 		 */
1383 		if ((iph->protocol ^ iph2->protocol) |
1384 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1385 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1386 			NAPI_GRO_CB(p)->same_flow = 0;
1387 			continue;
1388 		}
1389 
1390 		/* All fields must match except length and checksum. */
1391 		NAPI_GRO_CB(p)->flush |=
1392 			(iph->ttl ^ iph2->ttl) |
1393 			(iph->tos ^ iph2->tos) |
1394 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1395 
1396 		/* Save the IP ID check to be included later when we get to
1397 		 * the transport layer so only the inner most IP ID is checked.
1398 		 * This is because some GSO/TSO implementations do not
1399 		 * correctly increment the IP ID for the outer hdrs.
1400 		 */
1401 		NAPI_GRO_CB(p)->flush_id =
1402 			    ((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1403 		NAPI_GRO_CB(p)->flush |= flush;
1404 	}
1405 
1406 	NAPI_GRO_CB(skb)->flush |= flush;
1407 	skb_set_network_header(skb, off);
1408 	/* The above will be needed by the transport layer if there is one
1409 	 * immediately following this IP hdr.
1410 	 */
1411 
1412 	skb_gro_pull(skb, sizeof(*iph));
1413 	skb_set_transport_header(skb, skb_gro_offset(skb));
1414 
1415 	pp = ops->callbacks.gro_receive(head, skb);
1416 
1417 out_unlock:
1418 	rcu_read_unlock();
1419 
1420 out:
1421 	NAPI_GRO_CB(skb)->flush |= flush;
1422 
1423 	return pp;
1424 }
1425 
1426 static int inet_gro_complete(struct sk_buff *skb, int nhoff)
1427 {
1428 	__be16 newlen = htons(skb->len - nhoff);
1429 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1430 	const struct net_offload *ops;
1431 	int proto = iph->protocol;
1432 	int err = -ENOSYS;
1433 
1434 	csum_replace2(&iph->check, iph->tot_len, newlen);
1435 	iph->tot_len = newlen;
1436 
1437 	rcu_read_lock();
1438 	ops = rcu_dereference(inet_offloads[proto]);
1439 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1440 		goto out_unlock;
1441 
1442 	/* Only need to add sizeof(*iph) to get to the next hdr below
1443 	 * because any hdr with option will have been flushed in
1444 	 * inet_gro_receive().
1445 	 */
1446 	err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1447 
1448 out_unlock:
1449 	rcu_read_unlock();
1450 
1451 	return err;
1452 }
1453 
1454 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1455 			 unsigned short type, unsigned char protocol,
1456 			 struct net *net)
1457 {
1458 	struct socket *sock;
1459 	int rc = sock_create_kern(family, type, protocol, &sock);
1460 
1461 	if (rc == 0) {
1462 		*sk = sock->sk;
1463 		(*sk)->sk_allocation = GFP_ATOMIC;
1464 		/*
1465 		 * Unhash it so that IP input processing does not even see it,
1466 		 * we do not wish this socket to see incoming packets.
1467 		 */
1468 		(*sk)->sk_prot->unhash(*sk);
1469 
1470 		sk_change_net(*sk, net);
1471 	}
1472 	return rc;
1473 }
1474 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1475 
1476 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1477 {
1478 	unsigned long res = 0;
1479 	int i, j;
1480 
1481 	for_each_possible_cpu(i) {
1482 		for (j = 0; j < SNMP_ARRAY_SZ; j++)
1483 			res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1484 	}
1485 	return res;
1486 }
1487 EXPORT_SYMBOL_GPL(snmp_fold_field);
1488 
1489 #if BITS_PER_LONG==32
1490 
1491 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1492 {
1493 	u64 res = 0;
1494 	int cpu;
1495 
1496 	for_each_possible_cpu(cpu) {
1497 		void *bhptr;
1498 		struct u64_stats_sync *syncp;
1499 		u64 v;
1500 		unsigned int start;
1501 
1502 		bhptr = per_cpu_ptr(mib[0], cpu);
1503 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1504 		do {
1505 			start = u64_stats_fetch_begin_bh(syncp);
1506 			v = *(((u64 *) bhptr) + offt);
1507 		} while (u64_stats_fetch_retry_bh(syncp, start));
1508 
1509 		res += v;
1510 	}
1511 	return res;
1512 }
1513 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1514 #endif
1515 
1516 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1517 {
1518 	BUG_ON(ptr == NULL);
1519 	ptr[0] = __alloc_percpu(mibsize, align);
1520 	if (!ptr[0])
1521 		return -ENOMEM;
1522 
1523 #if SNMP_ARRAY_SZ == 2
1524 	ptr[1] = __alloc_percpu(mibsize, align);
1525 	if (!ptr[1]) {
1526 		free_percpu(ptr[0]);
1527 		ptr[0] = NULL;
1528 		return -ENOMEM;
1529 	}
1530 #endif
1531 	return 0;
1532 }
1533 EXPORT_SYMBOL_GPL(snmp_mib_init);
1534 
1535 #ifdef CONFIG_IP_MULTICAST
1536 static const struct net_protocol igmp_protocol = {
1537 	.handler =	igmp_rcv,
1538 	.netns_ok =	1,
1539 };
1540 #endif
1541 
1542 static const struct net_protocol tcp_protocol = {
1543 	.early_demux	=	tcp_v4_early_demux,
1544 	.handler	=	tcp_v4_rcv,
1545 	.err_handler	=	tcp_v4_err,
1546 	.no_policy	=	1,
1547 	.netns_ok	=	1,
1548 	.icmp_strict_tag_validation = 1,
1549 };
1550 
1551 static const struct net_protocol udp_protocol = {
1552 	.early_demux =	udp_v4_early_demux,
1553 	.handler =	udp_rcv,
1554 	.err_handler =	udp_err,
1555 	.no_policy =	1,
1556 	.netns_ok =	1,
1557 };
1558 
1559 static const struct net_protocol icmp_protocol = {
1560 	.handler =	icmp_rcv,
1561 	.err_handler =	icmp_err,
1562 	.no_policy =	1,
1563 	.netns_ok =	1,
1564 };
1565 
1566 static __net_init int ipv4_mib_init_net(struct net *net)
1567 {
1568 	int i;
1569 
1570 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1571 			  sizeof(struct tcp_mib),
1572 			  __alignof__(struct tcp_mib)) < 0)
1573 		goto err_tcp_mib;
1574 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1575 			  sizeof(struct ipstats_mib),
1576 			  __alignof__(struct ipstats_mib)) < 0)
1577 		goto err_ip_mib;
1578 
1579 	for_each_possible_cpu(i) {
1580 		struct ipstats_mib *af_inet_stats;
1581 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics[0], i);
1582 		u64_stats_init(&af_inet_stats->syncp);
1583 #if SNMP_ARRAY_SZ == 2
1584 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics[1], i);
1585 		u64_stats_init(&af_inet_stats->syncp);
1586 #endif
1587 	}
1588 
1589 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1590 			  sizeof(struct linux_mib),
1591 			  __alignof__(struct linux_mib)) < 0)
1592 		goto err_net_mib;
1593 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1594 			  sizeof(struct udp_mib),
1595 			  __alignof__(struct udp_mib)) < 0)
1596 		goto err_udp_mib;
1597 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1598 			  sizeof(struct udp_mib),
1599 			  __alignof__(struct udp_mib)) < 0)
1600 		goto err_udplite_mib;
1601 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1602 			  sizeof(struct icmp_mib),
1603 			  __alignof__(struct icmp_mib)) < 0)
1604 		goto err_icmp_mib;
1605 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1606 					      GFP_KERNEL);
1607 	if (!net->mib.icmpmsg_statistics)
1608 		goto err_icmpmsg_mib;
1609 
1610 	tcp_mib_init(net);
1611 	return 0;
1612 
1613 err_icmpmsg_mib:
1614 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1615 err_icmp_mib:
1616 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1617 err_udplite_mib:
1618 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1619 err_udp_mib:
1620 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1621 err_net_mib:
1622 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1623 err_ip_mib:
1624 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1625 err_tcp_mib:
1626 	return -ENOMEM;
1627 }
1628 
1629 static __net_exit void ipv4_mib_exit_net(struct net *net)
1630 {
1631 	kfree(net->mib.icmpmsg_statistics);
1632 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1633 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1634 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1635 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1636 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1637 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1638 }
1639 
1640 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1641 	.init = ipv4_mib_init_net,
1642 	.exit = ipv4_mib_exit_net,
1643 };
1644 
1645 static int __init init_ipv4_mibs(void)
1646 {
1647 	return register_pernet_subsys(&ipv4_mib_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 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1704 	if (!sysctl_local_reserved_ports)
1705 		goto out;
1706 
1707 	rc = proto_register(&tcp_prot, 1);
1708 	if (rc)
1709 		goto out_free_reserved_ports;
1710 
1711 	rc = proto_register(&udp_prot, 1);
1712 	if (rc)
1713 		goto out_unregister_tcp_proto;
1714 
1715 	rc = proto_register(&raw_prot, 1);
1716 	if (rc)
1717 		goto out_unregister_udp_proto;
1718 
1719 	rc = proto_register(&ping_prot, 1);
1720 	if (rc)
1721 		goto out_unregister_raw_proto;
1722 
1723 	/*
1724 	 *	Tell SOCKET that we are alive...
1725 	 */
1726 
1727 	(void)sock_register(&inet_family_ops);
1728 
1729 #ifdef CONFIG_SYSCTL
1730 	ip_static_sysctl_init();
1731 #endif
1732 
1733 	/*
1734 	 *	Add all the base protocols.
1735 	 */
1736 
1737 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1738 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1739 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1740 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1741 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1742 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1743 #ifdef CONFIG_IP_MULTICAST
1744 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1745 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1746 #endif
1747 
1748 	/* Register the socket-side information for inet_create. */
1749 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1750 		INIT_LIST_HEAD(r);
1751 
1752 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1753 		inet_register_protosw(q);
1754 
1755 	/*
1756 	 *	Set the ARP module up
1757 	 */
1758 
1759 	arp_init();
1760 
1761 	/*
1762 	 *	Set the IP module up
1763 	 */
1764 
1765 	ip_init();
1766 
1767 	tcp_v4_init();
1768 
1769 	/* Setup TCP slab cache for open requests. */
1770 	tcp_init();
1771 
1772 	/* Setup UDP memory threshold */
1773 	udp_init();
1774 
1775 	/* Add UDP-Lite (RFC 3828) */
1776 	udplite4_register();
1777 
1778 	ping_init();
1779 
1780 	/*
1781 	 *	Set the ICMP layer up
1782 	 */
1783 
1784 	if (icmp_init() < 0)
1785 		panic("Failed to create the ICMP control socket.\n");
1786 
1787 	/*
1788 	 *	Initialise the multicast router
1789 	 */
1790 #if defined(CONFIG_IP_MROUTE)
1791 	if (ip_mr_init())
1792 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1793 #endif
1794 	/*
1795 	 *	Initialise per-cpu ipv4 mibs
1796 	 */
1797 
1798 	if (init_ipv4_mibs())
1799 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1800 
1801 	ipv4_proc_init();
1802 
1803 	ipfrag_init();
1804 
1805 	dev_add_pack(&ip_packet_type);
1806 
1807 	rc = 0;
1808 out:
1809 	return rc;
1810 out_unregister_raw_proto:
1811 	proto_unregister(&raw_prot);
1812 out_unregister_udp_proto:
1813 	proto_unregister(&udp_prot);
1814 out_unregister_tcp_proto:
1815 	proto_unregister(&tcp_prot);
1816 out_free_reserved_ports:
1817 	kfree(sysctl_local_reserved_ports);
1818 	goto out;
1819 }
1820 
1821 fs_initcall(inet_init);
1822 
1823 /* ------------------------------------------------------------------------ */
1824 
1825 #ifdef CONFIG_PROC_FS
1826 static int __init ipv4_proc_init(void)
1827 {
1828 	int rc = 0;
1829 
1830 	if (raw_proc_init())
1831 		goto out_raw;
1832 	if (tcp4_proc_init())
1833 		goto out_tcp;
1834 	if (udp4_proc_init())
1835 		goto out_udp;
1836 	if (ping_proc_init())
1837 		goto out_ping;
1838 	if (ip_misc_proc_init())
1839 		goto out_misc;
1840 out:
1841 	return rc;
1842 out_misc:
1843 	ping_proc_exit();
1844 out_ping:
1845 	udp4_proc_exit();
1846 out_udp:
1847 	tcp4_proc_exit();
1848 out_tcp:
1849 	raw_proc_exit();
1850 out_raw:
1851 	rc = -ENOMEM;
1852 	goto out;
1853 }
1854 
1855 #else /* CONFIG_PROC_FS */
1856 static int __init ipv4_proc_init(void)
1857 {
1858 	return 0;
1859 }
1860 #endif /* CONFIG_PROC_FS */
1861 
1862 MODULE_ALIAS_NETPROTO(PF_INET);
1863 
1864