xref: /openbmc/linux/net/ipv4/af_inet.c (revision 31b90347)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		PF_INET protocol family socket handler.
7  *
8  * Authors:	Ross Biro
9  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10  *		Florian La Roche, <flla@stud.uni-sb.de>
11  *		Alan Cox, <A.Cox@swansea.ac.uk>
12  *
13  * Changes (see also sock.c)
14  *
15  *		piggy,
16  *		Karl Knutson	:	Socket protocol table
17  *		A.N.Kuznetsov	:	Socket death error in accept().
18  *		John Richardson :	Fix non blocking error in connect()
19  *					so sockets that fail to connect
20  *					don't return -EINPROGRESS.
21  *		Alan Cox	:	Asynchronous I/O support
22  *		Alan Cox	:	Keep correct socket pointer on sock
23  *					structures
24  *					when accept() ed
25  *		Alan Cox	:	Semantics of SO_LINGER aren't state
26  *					moved to close when you look carefully.
27  *					With this fixed and the accept bug fixed
28  *					some RPC stuff seems happier.
29  *		Niibe Yutaka	:	4.4BSD style write async I/O
30  *		Alan Cox,
31  *		Tony Gale 	:	Fixed reuse semantics.
32  *		Alan Cox	:	bind() shouldn't abort existing but dead
33  *					sockets. Stops FTP netin:.. I hope.
34  *		Alan Cox	:	bind() works correctly for RAW sockets.
35  *					Note that FreeBSD at least was broken
36  *					in this respect so be careful with
37  *					compatibility tests...
38  *		Alan Cox	:	routing cache support
39  *		Alan Cox	:	memzero the socket structure for
40  *					compactness.
41  *		Matt Day	:	nonblock connect error handler
42  *		Alan Cox	:	Allow large numbers of pending sockets
43  *					(eg for big web sites), but only if
44  *					specifically application requested.
45  *		Alan Cox	:	New buffering throughout IP. Used
46  *					dumbly.
47  *		Alan Cox	:	New buffering now used smartly.
48  *		Alan Cox	:	BSD rather than common sense
49  *					interpretation of listen.
50  *		Germano Caronni	:	Assorted small races.
51  *		Alan Cox	:	sendmsg/recvmsg basic support.
52  *		Alan Cox	:	Only sendmsg/recvmsg now supported.
53  *		Alan Cox	:	Locked down bind (see security list).
54  *		Alan Cox	:	Loosened bind a little.
55  *		Mike McLagan	:	ADD/DEL DLCI Ioctls
56  *	Willy Konynenberg	:	Transparent proxying support.
57  *		David S. Miller	:	New socket lookup architecture.
58  *					Some other random speedups.
59  *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
60  *		Andi Kleen	:	Fix inet_stream_connect TCP race.
61  *
62  *		This program is free software; you can redistribute it and/or
63  *		modify it under the terms of the GNU General Public License
64  *		as published by the Free Software Foundation; either version
65  *		2 of the License, or (at your option) any later version.
66  */
67 
68 #define pr_fmt(fmt) "IPv4: " fmt
69 
70 #include <linux/err.h>
71 #include <linux/errno.h>
72 #include <linux/types.h>
73 #include <linux/socket.h>
74 #include <linux/in.h>
75 #include <linux/kernel.h>
76 #include <linux/module.h>
77 #include <linux/sched.h>
78 #include <linux/timer.h>
79 #include <linux/string.h>
80 #include <linux/sockios.h>
81 #include <linux/net.h>
82 #include <linux/capability.h>
83 #include <linux/fcntl.h>
84 #include <linux/mm.h>
85 #include <linux/interrupt.h>
86 #include <linux/stat.h>
87 #include <linux/init.h>
88 #include <linux/poll.h>
89 #include <linux/netfilter_ipv4.h>
90 #include <linux/random.h>
91 #include <linux/slab.h>
92 
93 #include <asm/uaccess.h>
94 
95 #include <linux/inet.h>
96 #include <linux/igmp.h>
97 #include <linux/inetdevice.h>
98 #include <linux/netdevice.h>
99 #include <net/checksum.h>
100 #include <net/ip.h>
101 #include <net/protocol.h>
102 #include <net/arp.h>
103 #include <net/route.h>
104 #include <net/ip_fib.h>
105 #include <net/inet_connection_sock.h>
106 #include <net/tcp.h>
107 #include <net/udp.h>
108 #include <net/udplite.h>
109 #include <net/ping.h>
110 #include <linux/skbuff.h>
111 #include <net/sock.h>
112 #include <net/raw.h>
113 #include <net/icmp.h>
114 #include <net/inet_common.h>
115 #include <net/xfrm.h>
116 #include <net/net_namespace.h>
117 #include <net/secure_seq.h>
118 #ifdef CONFIG_IP_MROUTE
119 #include <linux/mroute.h>
120 #endif
121 
122 
123 /* The inetsw table contains everything that inet_create needs to
124  * build a new socket.
125  */
126 static struct list_head inetsw[SOCK_MAX];
127 static DEFINE_SPINLOCK(inetsw_lock);
128 
129 struct ipv4_config ipv4_config;
130 EXPORT_SYMBOL(ipv4_config);
131 
132 /* New destruction routine */
133 
134 void inet_sock_destruct(struct sock *sk)
135 {
136 	struct inet_sock *inet = inet_sk(sk);
137 
138 	__skb_queue_purge(&sk->sk_receive_queue);
139 	__skb_queue_purge(&sk->sk_error_queue);
140 
141 	sk_mem_reclaim(sk);
142 
143 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
144 		pr_err("Attempt to release TCP socket in state %d %p\n",
145 		       sk->sk_state, sk);
146 		return;
147 	}
148 	if (!sock_flag(sk, SOCK_DEAD)) {
149 		pr_err("Attempt to release alive inet socket %p\n", sk);
150 		return;
151 	}
152 
153 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
154 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
155 	WARN_ON(sk->sk_wmem_queued);
156 	WARN_ON(sk->sk_forward_alloc);
157 
158 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
159 	dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
160 	dst_release(sk->sk_rx_dst);
161 	sk_refcnt_debug_dec(sk);
162 }
163 EXPORT_SYMBOL(inet_sock_destruct);
164 
165 /*
166  *	The routines beyond this point handle the behaviour of an AF_INET
167  *	socket object. Mostly it punts to the subprotocols of IP to do
168  *	the work.
169  */
170 
171 /*
172  *	Automatically bind an unbound socket.
173  */
174 
175 static int inet_autobind(struct sock *sk)
176 {
177 	struct inet_sock *inet;
178 	/* We may need to bind the socket. */
179 	lock_sock(sk);
180 	inet = inet_sk(sk);
181 	if (!inet->inet_num) {
182 		if (sk->sk_prot->get_port(sk, 0)) {
183 			release_sock(sk);
184 			return -EAGAIN;
185 		}
186 		inet->inet_sport = htons(inet->inet_num);
187 	}
188 	release_sock(sk);
189 	return 0;
190 }
191 
192 /*
193  *	Move a socket into listening state.
194  */
195 int inet_listen(struct socket *sock, int backlog)
196 {
197 	struct sock *sk = sock->sk;
198 	unsigned char old_state;
199 	int err;
200 
201 	lock_sock(sk);
202 
203 	err = -EINVAL;
204 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
205 		goto out;
206 
207 	old_state = sk->sk_state;
208 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
209 		goto out;
210 
211 	/* Really, if the socket is already in listen state
212 	 * we can only allow the backlog to be adjusted.
213 	 */
214 	if (old_state != TCP_LISTEN) {
215 		/* Check special setups for testing purpose to enable TFO w/o
216 		 * requiring TCP_FASTOPEN sockopt.
217 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
218 		 * Also fastopenq may already been allocated because this
219 		 * socket was in TCP_LISTEN state previously but was
220 		 * shutdown() (rather than close()).
221 		 */
222 		if ((sysctl_tcp_fastopen & TFO_SERVER_ENABLE) != 0 &&
223 		    inet_csk(sk)->icsk_accept_queue.fastopenq == NULL) {
224 			if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) != 0)
225 				err = fastopen_init_queue(sk, backlog);
226 			else if ((sysctl_tcp_fastopen &
227 				  TFO_SERVER_WO_SOCKOPT2) != 0)
228 				err = fastopen_init_queue(sk,
229 				    ((uint)sysctl_tcp_fastopen) >> 16);
230 			else
231 				err = 0;
232 			if (err)
233 				goto out;
234 		}
235 		err = inet_csk_listen_start(sk, backlog);
236 		if (err)
237 			goto out;
238 	}
239 	sk->sk_max_ack_backlog = backlog;
240 	err = 0;
241 
242 out:
243 	release_sock(sk);
244 	return err;
245 }
246 EXPORT_SYMBOL(inet_listen);
247 
248 /*
249  *	Create an inet socket.
250  */
251 
252 static int inet_create(struct net *net, struct socket *sock, int protocol,
253 		       int kern)
254 {
255 	struct sock *sk;
256 	struct inet_protosw *answer;
257 	struct inet_sock *inet;
258 	struct proto *answer_prot;
259 	unsigned char answer_flags;
260 	char answer_no_check;
261 	int try_loading_module = 0;
262 	int err;
263 
264 	sock->state = SS_UNCONNECTED;
265 
266 	/* Look for the requested type/protocol pair. */
267 lookup_protocol:
268 	err = -ESOCKTNOSUPPORT;
269 	rcu_read_lock();
270 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
271 
272 		err = 0;
273 		/* Check the non-wild match. */
274 		if (protocol == answer->protocol) {
275 			if (protocol != IPPROTO_IP)
276 				break;
277 		} else {
278 			/* Check for the two wild cases. */
279 			if (IPPROTO_IP == protocol) {
280 				protocol = answer->protocol;
281 				break;
282 			}
283 			if (IPPROTO_IP == answer->protocol)
284 				break;
285 		}
286 		err = -EPROTONOSUPPORT;
287 	}
288 
289 	if (unlikely(err)) {
290 		if (try_loading_module < 2) {
291 			rcu_read_unlock();
292 			/*
293 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
294 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
295 			 */
296 			if (++try_loading_module == 1)
297 				request_module("net-pf-%d-proto-%d-type-%d",
298 					       PF_INET, protocol, sock->type);
299 			/*
300 			 * Fall back to generic, e.g. net-pf-2-proto-132
301 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
302 			 */
303 			else
304 				request_module("net-pf-%d-proto-%d",
305 					       PF_INET, protocol);
306 			goto lookup_protocol;
307 		} else
308 			goto out_rcu_unlock;
309 	}
310 
311 	err = -EPERM;
312 	if (sock->type == SOCK_RAW && !kern &&
313 	    !ns_capable(net->user_ns, CAP_NET_RAW))
314 		goto out_rcu_unlock;
315 
316 	sock->ops = answer->ops;
317 	answer_prot = answer->prot;
318 	answer_no_check = answer->no_check;
319 	answer_flags = answer->flags;
320 	rcu_read_unlock();
321 
322 	WARN_ON(answer_prot->slab == NULL);
323 
324 	err = -ENOBUFS;
325 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
326 	if (sk == NULL)
327 		goto out;
328 
329 	err = 0;
330 	sk->sk_no_check = answer_no_check;
331 	if (INET_PROTOSW_REUSE & answer_flags)
332 		sk->sk_reuse = SK_CAN_REUSE;
333 
334 	inet = inet_sk(sk);
335 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
336 
337 	inet->nodefrag = 0;
338 
339 	if (SOCK_RAW == sock->type) {
340 		inet->inet_num = protocol;
341 		if (IPPROTO_RAW == protocol)
342 			inet->hdrincl = 1;
343 	}
344 
345 	if (ipv4_config.no_pmtu_disc)
346 		inet->pmtudisc = IP_PMTUDISC_DONT;
347 	else
348 		inet->pmtudisc = IP_PMTUDISC_WANT;
349 
350 	inet->inet_id = 0;
351 
352 	sock_init_data(sock, sk);
353 
354 	sk->sk_destruct	   = inet_sock_destruct;
355 	sk->sk_protocol	   = protocol;
356 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
357 
358 	inet->uc_ttl	= -1;
359 	inet->mc_loop	= 1;
360 	inet->mc_ttl	= 1;
361 	inet->mc_all	= 1;
362 	inet->mc_index	= 0;
363 	inet->mc_list	= NULL;
364 	inet->rcv_tos	= 0;
365 
366 	sk_refcnt_debug_inc(sk);
367 
368 	if (inet->inet_num) {
369 		/* It assumes that any protocol which allows
370 		 * the user to assign a number at socket
371 		 * creation time automatically
372 		 * shares.
373 		 */
374 		inet->inet_sport = htons(inet->inet_num);
375 		/* Add to protocol hash chains. */
376 		sk->sk_prot->hash(sk);
377 	}
378 
379 	if (sk->sk_prot->init) {
380 		err = sk->sk_prot->init(sk);
381 		if (err)
382 			sk_common_release(sk);
383 	}
384 out:
385 	return err;
386 out_rcu_unlock:
387 	rcu_read_unlock();
388 	goto out;
389 }
390 
391 
392 /*
393  *	The peer socket should always be NULL (or else). When we call this
394  *	function we are destroying the object and from then on nobody
395  *	should refer to it.
396  */
397 int inet_release(struct socket *sock)
398 {
399 	struct sock *sk = sock->sk;
400 
401 	if (sk) {
402 		long timeout;
403 
404 		sock_rps_reset_flow(sk);
405 
406 		/* Applications forget to leave groups before exiting */
407 		ip_mc_drop_socket(sk);
408 
409 		/* If linger is set, we don't return until the close
410 		 * is complete.  Otherwise we return immediately. The
411 		 * actually closing is done the same either way.
412 		 *
413 		 * If the close is due to the process exiting, we never
414 		 * linger..
415 		 */
416 		timeout = 0;
417 		if (sock_flag(sk, SOCK_LINGER) &&
418 		    !(current->flags & PF_EXITING))
419 			timeout = sk->sk_lingertime;
420 		sock->sk = NULL;
421 		sk->sk_prot->close(sk, timeout);
422 	}
423 	return 0;
424 }
425 EXPORT_SYMBOL(inet_release);
426 
427 /* It is off by default, see below. */
428 int sysctl_ip_nonlocal_bind __read_mostly;
429 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
430 
431 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
432 {
433 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
434 	struct sock *sk = sock->sk;
435 	struct inet_sock *inet = inet_sk(sk);
436 	struct net *net = sock_net(sk);
437 	unsigned short snum;
438 	int chk_addr_ret;
439 	int err;
440 
441 	/* If the socket has its own bind function then use it. (RAW) */
442 	if (sk->sk_prot->bind) {
443 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
444 		goto out;
445 	}
446 	err = -EINVAL;
447 	if (addr_len < sizeof(struct sockaddr_in))
448 		goto out;
449 
450 	if (addr->sin_family != AF_INET) {
451 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
452 		 * only if s_addr is INADDR_ANY.
453 		 */
454 		err = -EAFNOSUPPORT;
455 		if (addr->sin_family != AF_UNSPEC ||
456 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
457 			goto out;
458 	}
459 
460 	chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
461 
462 	/* Not specified by any standard per-se, however it breaks too
463 	 * many applications when removed.  It is unfortunate since
464 	 * allowing applications to make a non-local bind solves
465 	 * several problems with systems using dynamic addressing.
466 	 * (ie. your servers still start up even if your ISDN link
467 	 *  is temporarily down)
468 	 */
469 	err = -EADDRNOTAVAIL;
470 	if (!sysctl_ip_nonlocal_bind &&
471 	    !(inet->freebind || inet->transparent) &&
472 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
473 	    chk_addr_ret != RTN_LOCAL &&
474 	    chk_addr_ret != RTN_MULTICAST &&
475 	    chk_addr_ret != RTN_BROADCAST)
476 		goto out;
477 
478 	snum = ntohs(addr->sin_port);
479 	err = -EACCES;
480 	if (snum && snum < PROT_SOCK &&
481 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
482 		goto out;
483 
484 	/*      We keep a pair of addresses. rcv_saddr is the one
485 	 *      used by hash lookups, and saddr is used for transmit.
486 	 *
487 	 *      In the BSD API these are the same except where it
488 	 *      would be illegal to use them (multicast/broadcast) in
489 	 *      which case the sending device address is used.
490 	 */
491 	lock_sock(sk);
492 
493 	/* Check these errors (active socket, double bind). */
494 	err = -EINVAL;
495 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
496 		goto out_release_sock;
497 
498 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
499 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
500 		inet->inet_saddr = 0;  /* Use device */
501 
502 	/* Make sure we are allowed to bind here. */
503 	if (sk->sk_prot->get_port(sk, snum)) {
504 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
505 		err = -EADDRINUSE;
506 		goto out_release_sock;
507 	}
508 
509 	if (inet->inet_rcv_saddr)
510 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
511 	if (snum)
512 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
513 	inet->inet_sport = htons(inet->inet_num);
514 	inet->inet_daddr = 0;
515 	inet->inet_dport = 0;
516 	sk_dst_reset(sk);
517 	err = 0;
518 out_release_sock:
519 	release_sock(sk);
520 out:
521 	return err;
522 }
523 EXPORT_SYMBOL(inet_bind);
524 
525 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
526 		       int addr_len, int flags)
527 {
528 	struct sock *sk = sock->sk;
529 
530 	if (addr_len < sizeof(uaddr->sa_family))
531 		return -EINVAL;
532 	if (uaddr->sa_family == AF_UNSPEC)
533 		return sk->sk_prot->disconnect(sk, flags);
534 
535 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
536 		return -EAGAIN;
537 	return sk->sk_prot->connect(sk, uaddr, addr_len);
538 }
539 EXPORT_SYMBOL(inet_dgram_connect);
540 
541 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
542 {
543 	DEFINE_WAIT(wait);
544 
545 	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
546 	sk->sk_write_pending += writebias;
547 
548 	/* Basic assumption: if someone sets sk->sk_err, he _must_
549 	 * change state of the socket from TCP_SYN_*.
550 	 * Connect() does not allow to get error notifications
551 	 * without closing the socket.
552 	 */
553 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
554 		release_sock(sk);
555 		timeo = schedule_timeout(timeo);
556 		lock_sock(sk);
557 		if (signal_pending(current) || !timeo)
558 			break;
559 		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
560 	}
561 	finish_wait(sk_sleep(sk), &wait);
562 	sk->sk_write_pending -= writebias;
563 	return timeo;
564 }
565 
566 /*
567  *	Connect to a remote host. There is regrettably still a little
568  *	TCP 'magic' in here.
569  */
570 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
571 			  int addr_len, int flags)
572 {
573 	struct sock *sk = sock->sk;
574 	int err;
575 	long timeo;
576 
577 	if (addr_len < sizeof(uaddr->sa_family))
578 		return -EINVAL;
579 
580 	if (uaddr->sa_family == AF_UNSPEC) {
581 		err = sk->sk_prot->disconnect(sk, flags);
582 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
583 		goto out;
584 	}
585 
586 	switch (sock->state) {
587 	default:
588 		err = -EINVAL;
589 		goto out;
590 	case SS_CONNECTED:
591 		err = -EISCONN;
592 		goto out;
593 	case SS_CONNECTING:
594 		err = -EALREADY;
595 		/* Fall out of switch with err, set for this state */
596 		break;
597 	case SS_UNCONNECTED:
598 		err = -EISCONN;
599 		if (sk->sk_state != TCP_CLOSE)
600 			goto out;
601 
602 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
603 		if (err < 0)
604 			goto out;
605 
606 		sock->state = SS_CONNECTING;
607 
608 		/* Just entered SS_CONNECTING state; the only
609 		 * difference is that return value in non-blocking
610 		 * case is EINPROGRESS, rather than EALREADY.
611 		 */
612 		err = -EINPROGRESS;
613 		break;
614 	}
615 
616 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
617 
618 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
619 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
620 				tcp_sk(sk)->fastopen_req &&
621 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
622 
623 		/* Error code is set above */
624 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
625 			goto out;
626 
627 		err = sock_intr_errno(timeo);
628 		if (signal_pending(current))
629 			goto out;
630 	}
631 
632 	/* Connection was closed by RST, timeout, ICMP error
633 	 * or another process disconnected us.
634 	 */
635 	if (sk->sk_state == TCP_CLOSE)
636 		goto sock_error;
637 
638 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
639 	 * and error was received after socket entered established state.
640 	 * Hence, it is handled normally after connect() return successfully.
641 	 */
642 
643 	sock->state = SS_CONNECTED;
644 	err = 0;
645 out:
646 	return err;
647 
648 sock_error:
649 	err = sock_error(sk) ? : -ECONNABORTED;
650 	sock->state = SS_UNCONNECTED;
651 	if (sk->sk_prot->disconnect(sk, flags))
652 		sock->state = SS_DISCONNECTING;
653 	goto out;
654 }
655 EXPORT_SYMBOL(__inet_stream_connect);
656 
657 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
658 			int addr_len, int flags)
659 {
660 	int err;
661 
662 	lock_sock(sock->sk);
663 	err = __inet_stream_connect(sock, uaddr, addr_len, flags);
664 	release_sock(sock->sk);
665 	return err;
666 }
667 EXPORT_SYMBOL(inet_stream_connect);
668 
669 /*
670  *	Accept a pending connection. The TCP layer now gives BSD semantics.
671  */
672 
673 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
674 {
675 	struct sock *sk1 = sock->sk;
676 	int err = -EINVAL;
677 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
678 
679 	if (!sk2)
680 		goto do_err;
681 
682 	lock_sock(sk2);
683 
684 	sock_rps_record_flow(sk2);
685 	WARN_ON(!((1 << sk2->sk_state) &
686 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
687 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
688 
689 	sock_graft(sk2, newsock);
690 
691 	newsock->state = SS_CONNECTED;
692 	err = 0;
693 	release_sock(sk2);
694 do_err:
695 	return err;
696 }
697 EXPORT_SYMBOL(inet_accept);
698 
699 
700 /*
701  *	This does both peername and sockname.
702  */
703 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
704 			int *uaddr_len, int peer)
705 {
706 	struct sock *sk		= sock->sk;
707 	struct inet_sock *inet	= inet_sk(sk);
708 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
709 
710 	sin->sin_family = AF_INET;
711 	if (peer) {
712 		if (!inet->inet_dport ||
713 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
714 		     peer == 1))
715 			return -ENOTCONN;
716 		sin->sin_port = inet->inet_dport;
717 		sin->sin_addr.s_addr = inet->inet_daddr;
718 	} else {
719 		__be32 addr = inet->inet_rcv_saddr;
720 		if (!addr)
721 			addr = inet->inet_saddr;
722 		sin->sin_port = inet->inet_sport;
723 		sin->sin_addr.s_addr = addr;
724 	}
725 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
726 	*uaddr_len = sizeof(*sin);
727 	return 0;
728 }
729 EXPORT_SYMBOL(inet_getname);
730 
731 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
732 		 size_t size)
733 {
734 	struct sock *sk = sock->sk;
735 
736 	sock_rps_record_flow(sk);
737 
738 	/* We may need to bind the socket. */
739 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
740 	    inet_autobind(sk))
741 		return -EAGAIN;
742 
743 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
744 }
745 EXPORT_SYMBOL(inet_sendmsg);
746 
747 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
748 		      size_t size, int flags)
749 {
750 	struct sock *sk = sock->sk;
751 
752 	sock_rps_record_flow(sk);
753 
754 	/* We may need to bind the socket. */
755 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
756 	    inet_autobind(sk))
757 		return -EAGAIN;
758 
759 	if (sk->sk_prot->sendpage)
760 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
761 	return sock_no_sendpage(sock, page, offset, size, flags);
762 }
763 EXPORT_SYMBOL(inet_sendpage);
764 
765 int inet_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
766 		 size_t size, int flags)
767 {
768 	struct sock *sk = sock->sk;
769 	int addr_len = 0;
770 	int err;
771 
772 	sock_rps_record_flow(sk);
773 
774 	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
775 				   flags & ~MSG_DONTWAIT, &addr_len);
776 	if (err >= 0)
777 		msg->msg_namelen = addr_len;
778 	return err;
779 }
780 EXPORT_SYMBOL(inet_recvmsg);
781 
782 int inet_shutdown(struct socket *sock, int how)
783 {
784 	struct sock *sk = sock->sk;
785 	int err = 0;
786 
787 	/* This should really check to make sure
788 	 * the socket is a TCP socket. (WHY AC...)
789 	 */
790 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
791 		       1->2 bit 2 snds.
792 		       2->3 */
793 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
794 		return -EINVAL;
795 
796 	lock_sock(sk);
797 	if (sock->state == SS_CONNECTING) {
798 		if ((1 << sk->sk_state) &
799 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
800 			sock->state = SS_DISCONNECTING;
801 		else
802 			sock->state = SS_CONNECTED;
803 	}
804 
805 	switch (sk->sk_state) {
806 	case TCP_CLOSE:
807 		err = -ENOTCONN;
808 		/* Hack to wake up other listeners, who can poll for
809 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
810 	default:
811 		sk->sk_shutdown |= how;
812 		if (sk->sk_prot->shutdown)
813 			sk->sk_prot->shutdown(sk, how);
814 		break;
815 
816 	/* Remaining two branches are temporary solution for missing
817 	 * close() in multithreaded environment. It is _not_ a good idea,
818 	 * but we have no choice until close() is repaired at VFS level.
819 	 */
820 	case TCP_LISTEN:
821 		if (!(how & RCV_SHUTDOWN))
822 			break;
823 		/* Fall through */
824 	case TCP_SYN_SENT:
825 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
826 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
827 		break;
828 	}
829 
830 	/* Wake up anyone sleeping in poll. */
831 	sk->sk_state_change(sk);
832 	release_sock(sk);
833 	return err;
834 }
835 EXPORT_SYMBOL(inet_shutdown);
836 
837 /*
838  *	ioctl() calls you can issue on an INET socket. Most of these are
839  *	device configuration and stuff and very rarely used. Some ioctls
840  *	pass on to the socket itself.
841  *
842  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
843  *	loads the devconfigure module does its configuring and unloads it.
844  *	There's a good 20K of config code hanging around the kernel.
845  */
846 
847 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
848 {
849 	struct sock *sk = sock->sk;
850 	int err = 0;
851 	struct net *net = sock_net(sk);
852 
853 	switch (cmd) {
854 	case SIOCGSTAMP:
855 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
856 		break;
857 	case SIOCGSTAMPNS:
858 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
859 		break;
860 	case SIOCADDRT:
861 	case SIOCDELRT:
862 	case SIOCRTMSG:
863 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
864 		break;
865 	case SIOCDARP:
866 	case SIOCGARP:
867 	case SIOCSARP:
868 		err = arp_ioctl(net, cmd, (void __user *)arg);
869 		break;
870 	case SIOCGIFADDR:
871 	case SIOCSIFADDR:
872 	case SIOCGIFBRDADDR:
873 	case SIOCSIFBRDADDR:
874 	case SIOCGIFNETMASK:
875 	case SIOCSIFNETMASK:
876 	case SIOCGIFDSTADDR:
877 	case SIOCSIFDSTADDR:
878 	case SIOCSIFPFLAGS:
879 	case SIOCGIFPFLAGS:
880 	case SIOCSIFFLAGS:
881 		err = devinet_ioctl(net, cmd, (void __user *)arg);
882 		break;
883 	default:
884 		if (sk->sk_prot->ioctl)
885 			err = sk->sk_prot->ioctl(sk, cmd, arg);
886 		else
887 			err = -ENOIOCTLCMD;
888 		break;
889 	}
890 	return err;
891 }
892 EXPORT_SYMBOL(inet_ioctl);
893 
894 #ifdef CONFIG_COMPAT
895 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
896 {
897 	struct sock *sk = sock->sk;
898 	int err = -ENOIOCTLCMD;
899 
900 	if (sk->sk_prot->compat_ioctl)
901 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
902 
903 	return err;
904 }
905 #endif
906 
907 const struct proto_ops inet_stream_ops = {
908 	.family		   = PF_INET,
909 	.owner		   = THIS_MODULE,
910 	.release	   = inet_release,
911 	.bind		   = inet_bind,
912 	.connect	   = inet_stream_connect,
913 	.socketpair	   = sock_no_socketpair,
914 	.accept		   = inet_accept,
915 	.getname	   = inet_getname,
916 	.poll		   = tcp_poll,
917 	.ioctl		   = inet_ioctl,
918 	.listen		   = inet_listen,
919 	.shutdown	   = inet_shutdown,
920 	.setsockopt	   = sock_common_setsockopt,
921 	.getsockopt	   = sock_common_getsockopt,
922 	.sendmsg	   = inet_sendmsg,
923 	.recvmsg	   = inet_recvmsg,
924 	.mmap		   = sock_no_mmap,
925 	.sendpage	   = inet_sendpage,
926 	.splice_read	   = tcp_splice_read,
927 #ifdef CONFIG_COMPAT
928 	.compat_setsockopt = compat_sock_common_setsockopt,
929 	.compat_getsockopt = compat_sock_common_getsockopt,
930 	.compat_ioctl	   = inet_compat_ioctl,
931 #endif
932 };
933 EXPORT_SYMBOL(inet_stream_ops);
934 
935 const struct proto_ops inet_dgram_ops = {
936 	.family		   = PF_INET,
937 	.owner		   = THIS_MODULE,
938 	.release	   = inet_release,
939 	.bind		   = inet_bind,
940 	.connect	   = inet_dgram_connect,
941 	.socketpair	   = sock_no_socketpair,
942 	.accept		   = sock_no_accept,
943 	.getname	   = inet_getname,
944 	.poll		   = udp_poll,
945 	.ioctl		   = inet_ioctl,
946 	.listen		   = sock_no_listen,
947 	.shutdown	   = inet_shutdown,
948 	.setsockopt	   = sock_common_setsockopt,
949 	.getsockopt	   = sock_common_getsockopt,
950 	.sendmsg	   = inet_sendmsg,
951 	.recvmsg	   = inet_recvmsg,
952 	.mmap		   = sock_no_mmap,
953 	.sendpage	   = inet_sendpage,
954 #ifdef CONFIG_COMPAT
955 	.compat_setsockopt = compat_sock_common_setsockopt,
956 	.compat_getsockopt = compat_sock_common_getsockopt,
957 	.compat_ioctl	   = inet_compat_ioctl,
958 #endif
959 };
960 EXPORT_SYMBOL(inet_dgram_ops);
961 
962 /*
963  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
964  * udp_poll
965  */
966 static const struct proto_ops inet_sockraw_ops = {
967 	.family		   = PF_INET,
968 	.owner		   = THIS_MODULE,
969 	.release	   = inet_release,
970 	.bind		   = inet_bind,
971 	.connect	   = inet_dgram_connect,
972 	.socketpair	   = sock_no_socketpair,
973 	.accept		   = sock_no_accept,
974 	.getname	   = inet_getname,
975 	.poll		   = datagram_poll,
976 	.ioctl		   = inet_ioctl,
977 	.listen		   = sock_no_listen,
978 	.shutdown	   = inet_shutdown,
979 	.setsockopt	   = sock_common_setsockopt,
980 	.getsockopt	   = sock_common_getsockopt,
981 	.sendmsg	   = inet_sendmsg,
982 	.recvmsg	   = inet_recvmsg,
983 	.mmap		   = sock_no_mmap,
984 	.sendpage	   = inet_sendpage,
985 #ifdef CONFIG_COMPAT
986 	.compat_setsockopt = compat_sock_common_setsockopt,
987 	.compat_getsockopt = compat_sock_common_getsockopt,
988 	.compat_ioctl	   = inet_compat_ioctl,
989 #endif
990 };
991 
992 static const struct net_proto_family inet_family_ops = {
993 	.family = PF_INET,
994 	.create = inet_create,
995 	.owner	= THIS_MODULE,
996 };
997 
998 /* Upon startup we insert all the elements in inetsw_array[] into
999  * the linked list inetsw.
1000  */
1001 static struct inet_protosw inetsw_array[] =
1002 {
1003 	{
1004 		.type =       SOCK_STREAM,
1005 		.protocol =   IPPROTO_TCP,
1006 		.prot =       &tcp_prot,
1007 		.ops =        &inet_stream_ops,
1008 		.no_check =   0,
1009 		.flags =      INET_PROTOSW_PERMANENT |
1010 			      INET_PROTOSW_ICSK,
1011 	},
1012 
1013 	{
1014 		.type =       SOCK_DGRAM,
1015 		.protocol =   IPPROTO_UDP,
1016 		.prot =       &udp_prot,
1017 		.ops =        &inet_dgram_ops,
1018 		.no_check =   UDP_CSUM_DEFAULT,
1019 		.flags =      INET_PROTOSW_PERMANENT,
1020        },
1021 
1022        {
1023 		.type =       SOCK_DGRAM,
1024 		.protocol =   IPPROTO_ICMP,
1025 		.prot =       &ping_prot,
1026 		.ops =        &inet_dgram_ops,
1027 		.no_check =   UDP_CSUM_DEFAULT,
1028 		.flags =      INET_PROTOSW_REUSE,
1029        },
1030 
1031        {
1032 	       .type =       SOCK_RAW,
1033 	       .protocol =   IPPROTO_IP,	/* wild card */
1034 	       .prot =       &raw_prot,
1035 	       .ops =        &inet_sockraw_ops,
1036 	       .no_check =   UDP_CSUM_DEFAULT,
1037 	       .flags =      INET_PROTOSW_REUSE,
1038        }
1039 };
1040 
1041 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1042 
1043 void inet_register_protosw(struct inet_protosw *p)
1044 {
1045 	struct list_head *lh;
1046 	struct inet_protosw *answer;
1047 	int protocol = p->protocol;
1048 	struct list_head *last_perm;
1049 
1050 	spin_lock_bh(&inetsw_lock);
1051 
1052 	if (p->type >= SOCK_MAX)
1053 		goto out_illegal;
1054 
1055 	/* If we are trying to override a permanent protocol, bail. */
1056 	answer = NULL;
1057 	last_perm = &inetsw[p->type];
1058 	list_for_each(lh, &inetsw[p->type]) {
1059 		answer = list_entry(lh, struct inet_protosw, list);
1060 
1061 		/* Check only the non-wild match. */
1062 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1063 			if (protocol == answer->protocol)
1064 				break;
1065 			last_perm = lh;
1066 		}
1067 
1068 		answer = NULL;
1069 	}
1070 	if (answer)
1071 		goto out_permanent;
1072 
1073 	/* Add the new entry after the last permanent entry if any, so that
1074 	 * the new entry does not override a permanent entry when matched with
1075 	 * a wild-card protocol. But it is allowed to override any existing
1076 	 * non-permanent entry.  This means that when we remove this entry, the
1077 	 * system automatically returns to the old behavior.
1078 	 */
1079 	list_add_rcu(&p->list, last_perm);
1080 out:
1081 	spin_unlock_bh(&inetsw_lock);
1082 
1083 	return;
1084 
1085 out_permanent:
1086 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1087 	goto out;
1088 
1089 out_illegal:
1090 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1091 	       p->type);
1092 	goto out;
1093 }
1094 EXPORT_SYMBOL(inet_register_protosw);
1095 
1096 void inet_unregister_protosw(struct inet_protosw *p)
1097 {
1098 	if (INET_PROTOSW_PERMANENT & p->flags) {
1099 		pr_err("Attempt to unregister permanent protocol %d\n",
1100 		       p->protocol);
1101 	} else {
1102 		spin_lock_bh(&inetsw_lock);
1103 		list_del_rcu(&p->list);
1104 		spin_unlock_bh(&inetsw_lock);
1105 
1106 		synchronize_net();
1107 	}
1108 }
1109 EXPORT_SYMBOL(inet_unregister_protosw);
1110 
1111 /*
1112  *      Shall we try to damage output packets if routing dev changes?
1113  */
1114 
1115 int sysctl_ip_dynaddr __read_mostly;
1116 
1117 static int inet_sk_reselect_saddr(struct sock *sk)
1118 {
1119 	struct inet_sock *inet = inet_sk(sk);
1120 	__be32 old_saddr = inet->inet_saddr;
1121 	__be32 daddr = inet->inet_daddr;
1122 	struct flowi4 *fl4;
1123 	struct rtable *rt;
1124 	__be32 new_saddr;
1125 	struct ip_options_rcu *inet_opt;
1126 
1127 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1128 					     sock_owned_by_user(sk));
1129 	if (inet_opt && inet_opt->opt.srr)
1130 		daddr = inet_opt->opt.faddr;
1131 
1132 	/* Query new route. */
1133 	fl4 = &inet->cork.fl.u.ip4;
1134 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1135 			      sk->sk_bound_dev_if, sk->sk_protocol,
1136 			      inet->inet_sport, inet->inet_dport, sk, false);
1137 	if (IS_ERR(rt))
1138 		return PTR_ERR(rt);
1139 
1140 	sk_setup_caps(sk, &rt->dst);
1141 
1142 	new_saddr = fl4->saddr;
1143 
1144 	if (new_saddr == old_saddr)
1145 		return 0;
1146 
1147 	if (sysctl_ip_dynaddr > 1) {
1148 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1149 			__func__, &old_saddr, &new_saddr);
1150 	}
1151 
1152 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1153 
1154 	/*
1155 	 * XXX The only one ugly spot where we need to
1156 	 * XXX really change the sockets identity after
1157 	 * XXX it has entered the hashes. -DaveM
1158 	 *
1159 	 * Besides that, it does not check for connection
1160 	 * uniqueness. Wait for troubles.
1161 	 */
1162 	__sk_prot_rehash(sk);
1163 	return 0;
1164 }
1165 
1166 int inet_sk_rebuild_header(struct sock *sk)
1167 {
1168 	struct inet_sock *inet = inet_sk(sk);
1169 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1170 	__be32 daddr;
1171 	struct ip_options_rcu *inet_opt;
1172 	struct flowi4 *fl4;
1173 	int err;
1174 
1175 	/* Route is OK, nothing to do. */
1176 	if (rt)
1177 		return 0;
1178 
1179 	/* Reroute. */
1180 	rcu_read_lock();
1181 	inet_opt = rcu_dereference(inet->inet_opt);
1182 	daddr = inet->inet_daddr;
1183 	if (inet_opt && inet_opt->opt.srr)
1184 		daddr = inet_opt->opt.faddr;
1185 	rcu_read_unlock();
1186 	fl4 = &inet->cork.fl.u.ip4;
1187 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1188 				   inet->inet_dport, inet->inet_sport,
1189 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1190 				   sk->sk_bound_dev_if);
1191 	if (!IS_ERR(rt)) {
1192 		err = 0;
1193 		sk_setup_caps(sk, &rt->dst);
1194 	} else {
1195 		err = PTR_ERR(rt);
1196 
1197 		/* Routing failed... */
1198 		sk->sk_route_caps = 0;
1199 		/*
1200 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1201 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1202 		 */
1203 		if (!sysctl_ip_dynaddr ||
1204 		    sk->sk_state != TCP_SYN_SENT ||
1205 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1206 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1207 			sk->sk_err_soft = -err;
1208 	}
1209 
1210 	return err;
1211 }
1212 EXPORT_SYMBOL(inet_sk_rebuild_header);
1213 
1214 static int inet_gso_send_check(struct sk_buff *skb)
1215 {
1216 	const struct net_offload *ops;
1217 	const struct iphdr *iph;
1218 	int proto;
1219 	int ihl;
1220 	int err = -EINVAL;
1221 
1222 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1223 		goto out;
1224 
1225 	iph = ip_hdr(skb);
1226 	ihl = iph->ihl * 4;
1227 	if (ihl < sizeof(*iph))
1228 		goto out;
1229 
1230 	proto = iph->protocol;
1231 
1232 	/* Warning: after this point, iph might be no longer valid */
1233 	if (unlikely(!pskb_may_pull(skb, ihl)))
1234 		goto out;
1235 	__skb_pull(skb, ihl);
1236 
1237 	skb_reset_transport_header(skb);
1238 	err = -EPROTONOSUPPORT;
1239 
1240 	ops = rcu_dereference(inet_offloads[proto]);
1241 	if (likely(ops && ops->callbacks.gso_send_check))
1242 		err = ops->callbacks.gso_send_check(skb);
1243 
1244 out:
1245 	return err;
1246 }
1247 
1248 static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1249 					netdev_features_t features)
1250 {
1251 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1252 	const struct net_offload *ops;
1253 	unsigned int offset = 0;
1254 	bool udpfrag, encap;
1255 	struct iphdr *iph;
1256 	int proto;
1257 	int nhoff;
1258 	int ihl;
1259 	int id;
1260 
1261 	if (unlikely(skb_shinfo(skb)->gso_type &
1262 		     ~(SKB_GSO_TCPV4 |
1263 		       SKB_GSO_UDP |
1264 		       SKB_GSO_DODGY |
1265 		       SKB_GSO_TCP_ECN |
1266 		       SKB_GSO_GRE |
1267 		       SKB_GSO_IPIP |
1268 		       SKB_GSO_SIT |
1269 		       SKB_GSO_TCPV6 |
1270 		       SKB_GSO_UDP_TUNNEL |
1271 		       SKB_GSO_MPLS |
1272 		       0)))
1273 		goto out;
1274 
1275 	skb_reset_network_header(skb);
1276 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1277 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1278 		goto out;
1279 
1280 	iph = ip_hdr(skb);
1281 	ihl = iph->ihl * 4;
1282 	if (ihl < sizeof(*iph))
1283 		goto out;
1284 
1285 	id = ntohs(iph->id);
1286 	proto = iph->protocol;
1287 
1288 	/* Warning: after this point, iph might be no longer valid */
1289 	if (unlikely(!pskb_may_pull(skb, ihl)))
1290 		goto out;
1291 	__skb_pull(skb, ihl);
1292 
1293 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1294 	if (encap)
1295 		features = skb->dev->hw_enc_features & netif_skb_features(skb);
1296 	SKB_GSO_CB(skb)->encap_level += ihl;
1297 
1298 	skb_reset_transport_header(skb);
1299 
1300 	segs = ERR_PTR(-EPROTONOSUPPORT);
1301 
1302 	/* Note : following gso_segment() might change skb->encapsulation */
1303 	udpfrag = !skb->encapsulation && proto == IPPROTO_UDP;
1304 
1305 	ops = rcu_dereference(inet_offloads[proto]);
1306 	if (likely(ops && ops->callbacks.gso_segment))
1307 		segs = ops->callbacks.gso_segment(skb, features);
1308 
1309 	if (IS_ERR_OR_NULL(segs))
1310 		goto out;
1311 
1312 	skb = segs;
1313 	do {
1314 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1315 		if (udpfrag) {
1316 			iph->id = htons(id);
1317 			iph->frag_off = htons(offset >> 3);
1318 			if (skb->next != NULL)
1319 				iph->frag_off |= htons(IP_MF);
1320 			offset += skb->len - nhoff - ihl;
1321 		} else {
1322 			iph->id = htons(id++);
1323 		}
1324 		iph->tot_len = htons(skb->len - nhoff);
1325 		ip_send_check(iph);
1326 		if (encap)
1327 			skb_reset_inner_headers(skb);
1328 		skb->network_header = (u8 *)iph - skb->head;
1329 	} while ((skb = skb->next));
1330 
1331 out:
1332 	return segs;
1333 }
1334 
1335 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1336 					 struct sk_buff *skb)
1337 {
1338 	const struct net_offload *ops;
1339 	struct sk_buff **pp = NULL;
1340 	struct sk_buff *p;
1341 	const struct iphdr *iph;
1342 	unsigned int hlen;
1343 	unsigned int off;
1344 	unsigned int id;
1345 	int flush = 1;
1346 	int proto;
1347 
1348 	off = skb_gro_offset(skb);
1349 	hlen = off + sizeof(*iph);
1350 	iph = skb_gro_header_fast(skb, off);
1351 	if (skb_gro_header_hard(skb, hlen)) {
1352 		iph = skb_gro_header_slow(skb, hlen, off);
1353 		if (unlikely(!iph))
1354 			goto out;
1355 	}
1356 
1357 	proto = iph->protocol;
1358 
1359 	rcu_read_lock();
1360 	ops = rcu_dereference(inet_offloads[proto]);
1361 	if (!ops || !ops->callbacks.gro_receive)
1362 		goto out_unlock;
1363 
1364 	if (*(u8 *)iph != 0x45)
1365 		goto out_unlock;
1366 
1367 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1368 		goto out_unlock;
1369 
1370 	id = ntohl(*(__be32 *)&iph->id);
1371 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1372 	id >>= 16;
1373 
1374 	for (p = *head; p; p = p->next) {
1375 		struct iphdr *iph2;
1376 
1377 		if (!NAPI_GRO_CB(p)->same_flow)
1378 			continue;
1379 
1380 		iph2 = ip_hdr(p);
1381 
1382 		if ((iph->protocol ^ iph2->protocol) |
1383 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1384 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1385 			NAPI_GRO_CB(p)->same_flow = 0;
1386 			continue;
1387 		}
1388 
1389 		/* All fields must match except length and checksum. */
1390 		NAPI_GRO_CB(p)->flush |=
1391 			(iph->ttl ^ iph2->ttl) |
1392 			(iph->tos ^ iph2->tos) |
1393 			(__force int)((iph->frag_off ^ iph2->frag_off) & htons(IP_DF)) |
1394 			((u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) ^ id);
1395 
1396 		NAPI_GRO_CB(p)->flush |= flush;
1397 	}
1398 
1399 	NAPI_GRO_CB(skb)->flush |= flush;
1400 	skb_gro_pull(skb, sizeof(*iph));
1401 	skb_set_transport_header(skb, skb_gro_offset(skb));
1402 
1403 	pp = ops->callbacks.gro_receive(head, skb);
1404 
1405 out_unlock:
1406 	rcu_read_unlock();
1407 
1408 out:
1409 	NAPI_GRO_CB(skb)->flush |= flush;
1410 
1411 	return pp;
1412 }
1413 
1414 static int inet_gro_complete(struct sk_buff *skb)
1415 {
1416 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1417 	struct iphdr *iph = ip_hdr(skb);
1418 	const struct net_offload *ops;
1419 	int proto = iph->protocol;
1420 	int err = -ENOSYS;
1421 
1422 	csum_replace2(&iph->check, iph->tot_len, newlen);
1423 	iph->tot_len = newlen;
1424 
1425 	rcu_read_lock();
1426 	ops = rcu_dereference(inet_offloads[proto]);
1427 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1428 		goto out_unlock;
1429 
1430 	err = ops->callbacks.gro_complete(skb);
1431 
1432 out_unlock:
1433 	rcu_read_unlock();
1434 
1435 	return err;
1436 }
1437 
1438 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1439 			 unsigned short type, unsigned char protocol,
1440 			 struct net *net)
1441 {
1442 	struct socket *sock;
1443 	int rc = sock_create_kern(family, type, protocol, &sock);
1444 
1445 	if (rc == 0) {
1446 		*sk = sock->sk;
1447 		(*sk)->sk_allocation = GFP_ATOMIC;
1448 		/*
1449 		 * Unhash it so that IP input processing does not even see it,
1450 		 * we do not wish this socket to see incoming packets.
1451 		 */
1452 		(*sk)->sk_prot->unhash(*sk);
1453 
1454 		sk_change_net(*sk, net);
1455 	}
1456 	return rc;
1457 }
1458 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1459 
1460 unsigned long snmp_fold_field(void __percpu *mib[], int offt)
1461 {
1462 	unsigned long res = 0;
1463 	int i, j;
1464 
1465 	for_each_possible_cpu(i) {
1466 		for (j = 0; j < SNMP_ARRAY_SZ; j++)
1467 			res += *(((unsigned long *) per_cpu_ptr(mib[j], i)) + offt);
1468 	}
1469 	return res;
1470 }
1471 EXPORT_SYMBOL_GPL(snmp_fold_field);
1472 
1473 #if BITS_PER_LONG==32
1474 
1475 u64 snmp_fold_field64(void __percpu *mib[], int offt, size_t syncp_offset)
1476 {
1477 	u64 res = 0;
1478 	int cpu;
1479 
1480 	for_each_possible_cpu(cpu) {
1481 		void *bhptr;
1482 		struct u64_stats_sync *syncp;
1483 		u64 v;
1484 		unsigned int start;
1485 
1486 		bhptr = per_cpu_ptr(mib[0], cpu);
1487 		syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1488 		do {
1489 			start = u64_stats_fetch_begin_bh(syncp);
1490 			v = *(((u64 *) bhptr) + offt);
1491 		} while (u64_stats_fetch_retry_bh(syncp, start));
1492 
1493 		res += v;
1494 	}
1495 	return res;
1496 }
1497 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1498 #endif
1499 
1500 int snmp_mib_init(void __percpu *ptr[2], size_t mibsize, size_t align)
1501 {
1502 	BUG_ON(ptr == NULL);
1503 	ptr[0] = __alloc_percpu(mibsize, align);
1504 	if (!ptr[0])
1505 		return -ENOMEM;
1506 
1507 #if SNMP_ARRAY_SZ == 2
1508 	ptr[1] = __alloc_percpu(mibsize, align);
1509 	if (!ptr[1]) {
1510 		free_percpu(ptr[0]);
1511 		ptr[0] = NULL;
1512 		return -ENOMEM;
1513 	}
1514 #endif
1515 	return 0;
1516 }
1517 EXPORT_SYMBOL_GPL(snmp_mib_init);
1518 
1519 #ifdef CONFIG_IP_MULTICAST
1520 static const struct net_protocol igmp_protocol = {
1521 	.handler =	igmp_rcv,
1522 	.netns_ok =	1,
1523 };
1524 #endif
1525 
1526 static const struct net_protocol tcp_protocol = {
1527 	.early_demux	=	tcp_v4_early_demux,
1528 	.handler	=	tcp_v4_rcv,
1529 	.err_handler	=	tcp_v4_err,
1530 	.no_policy	=	1,
1531 	.netns_ok	=	1,
1532 };
1533 
1534 static const struct net_protocol udp_protocol = {
1535 	.early_demux =	udp_v4_early_demux,
1536 	.handler =	udp_rcv,
1537 	.err_handler =	udp_err,
1538 	.no_policy =	1,
1539 	.netns_ok =	1,
1540 };
1541 
1542 static const struct net_protocol icmp_protocol = {
1543 	.handler =	icmp_rcv,
1544 	.err_handler =	icmp_err,
1545 	.no_policy =	1,
1546 	.netns_ok =	1,
1547 };
1548 
1549 static __net_init int ipv4_mib_init_net(struct net *net)
1550 {
1551 	int i;
1552 
1553 	if (snmp_mib_init((void __percpu **)net->mib.tcp_statistics,
1554 			  sizeof(struct tcp_mib),
1555 			  __alignof__(struct tcp_mib)) < 0)
1556 		goto err_tcp_mib;
1557 	if (snmp_mib_init((void __percpu **)net->mib.ip_statistics,
1558 			  sizeof(struct ipstats_mib),
1559 			  __alignof__(struct ipstats_mib)) < 0)
1560 		goto err_ip_mib;
1561 
1562 	for_each_possible_cpu(i) {
1563 		struct ipstats_mib *af_inet_stats;
1564 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics[0], i);
1565 		u64_stats_init(&af_inet_stats->syncp);
1566 #if SNMP_ARRAY_SZ == 2
1567 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics[1], i);
1568 		u64_stats_init(&af_inet_stats->syncp);
1569 #endif
1570 	}
1571 
1572 	if (snmp_mib_init((void __percpu **)net->mib.net_statistics,
1573 			  sizeof(struct linux_mib),
1574 			  __alignof__(struct linux_mib)) < 0)
1575 		goto err_net_mib;
1576 	if (snmp_mib_init((void __percpu **)net->mib.udp_statistics,
1577 			  sizeof(struct udp_mib),
1578 			  __alignof__(struct udp_mib)) < 0)
1579 		goto err_udp_mib;
1580 	if (snmp_mib_init((void __percpu **)net->mib.udplite_statistics,
1581 			  sizeof(struct udp_mib),
1582 			  __alignof__(struct udp_mib)) < 0)
1583 		goto err_udplite_mib;
1584 	if (snmp_mib_init((void __percpu **)net->mib.icmp_statistics,
1585 			  sizeof(struct icmp_mib),
1586 			  __alignof__(struct icmp_mib)) < 0)
1587 		goto err_icmp_mib;
1588 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1589 					      GFP_KERNEL);
1590 	if (!net->mib.icmpmsg_statistics)
1591 		goto err_icmpmsg_mib;
1592 
1593 	tcp_mib_init(net);
1594 	return 0;
1595 
1596 err_icmpmsg_mib:
1597 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1598 err_icmp_mib:
1599 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1600 err_udplite_mib:
1601 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1602 err_udp_mib:
1603 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1604 err_net_mib:
1605 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1606 err_ip_mib:
1607 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1608 err_tcp_mib:
1609 	return -ENOMEM;
1610 }
1611 
1612 static __net_exit void ipv4_mib_exit_net(struct net *net)
1613 {
1614 	kfree(net->mib.icmpmsg_statistics);
1615 	snmp_mib_free((void __percpu **)net->mib.icmp_statistics);
1616 	snmp_mib_free((void __percpu **)net->mib.udplite_statistics);
1617 	snmp_mib_free((void __percpu **)net->mib.udp_statistics);
1618 	snmp_mib_free((void __percpu **)net->mib.net_statistics);
1619 	snmp_mib_free((void __percpu **)net->mib.ip_statistics);
1620 	snmp_mib_free((void __percpu **)net->mib.tcp_statistics);
1621 }
1622 
1623 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1624 	.init = ipv4_mib_init_net,
1625 	.exit = ipv4_mib_exit_net,
1626 };
1627 
1628 static int __init init_ipv4_mibs(void)
1629 {
1630 	return register_pernet_subsys(&ipv4_mib_ops);
1631 }
1632 
1633 static int ipv4_proc_init(void);
1634 
1635 /*
1636  *	IP protocol layer initialiser
1637  */
1638 
1639 static struct packet_offload ip_packet_offload __read_mostly = {
1640 	.type = cpu_to_be16(ETH_P_IP),
1641 	.callbacks = {
1642 		.gso_send_check = inet_gso_send_check,
1643 		.gso_segment = inet_gso_segment,
1644 		.gro_receive = inet_gro_receive,
1645 		.gro_complete = inet_gro_complete,
1646 	},
1647 };
1648 
1649 static const struct net_offload ipip_offload = {
1650 	.callbacks = {
1651 		.gso_send_check = inet_gso_send_check,
1652 		.gso_segment	= inet_gso_segment,
1653 	},
1654 };
1655 
1656 static int __init ipv4_offload_init(void)
1657 {
1658 	/*
1659 	 * Add offloads
1660 	 */
1661 	if (udpv4_offload_init() < 0)
1662 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1663 	if (tcpv4_offload_init() < 0)
1664 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1665 
1666 	dev_add_offload(&ip_packet_offload);
1667 	inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1668 	return 0;
1669 }
1670 
1671 fs_initcall(ipv4_offload_init);
1672 
1673 static struct packet_type ip_packet_type __read_mostly = {
1674 	.type = cpu_to_be16(ETH_P_IP),
1675 	.func = ip_rcv,
1676 };
1677 
1678 static int __init inet_init(void)
1679 {
1680 	struct inet_protosw *q;
1681 	struct list_head *r;
1682 	int rc = -EINVAL;
1683 
1684 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > FIELD_SIZEOF(struct sk_buff, cb));
1685 
1686 	sysctl_local_reserved_ports = kzalloc(65536 / 8, GFP_KERNEL);
1687 	if (!sysctl_local_reserved_ports)
1688 		goto out;
1689 
1690 	rc = proto_register(&tcp_prot, 1);
1691 	if (rc)
1692 		goto out_free_reserved_ports;
1693 
1694 	rc = proto_register(&udp_prot, 1);
1695 	if (rc)
1696 		goto out_unregister_tcp_proto;
1697 
1698 	rc = proto_register(&raw_prot, 1);
1699 	if (rc)
1700 		goto out_unregister_udp_proto;
1701 
1702 	rc = proto_register(&ping_prot, 1);
1703 	if (rc)
1704 		goto out_unregister_raw_proto;
1705 
1706 	/*
1707 	 *	Tell SOCKET that we are alive...
1708 	 */
1709 
1710 	(void)sock_register(&inet_family_ops);
1711 
1712 #ifdef CONFIG_SYSCTL
1713 	ip_static_sysctl_init();
1714 #endif
1715 
1716 	/*
1717 	 *	Add all the base protocols.
1718 	 */
1719 
1720 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1721 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1722 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1723 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1724 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1725 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1726 #ifdef CONFIG_IP_MULTICAST
1727 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1728 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1729 #endif
1730 
1731 	/* Register the socket-side information for inet_create. */
1732 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1733 		INIT_LIST_HEAD(r);
1734 
1735 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1736 		inet_register_protosw(q);
1737 
1738 	/*
1739 	 *	Set the ARP module up
1740 	 */
1741 
1742 	arp_init();
1743 
1744 	/*
1745 	 *	Set the IP module up
1746 	 */
1747 
1748 	ip_init();
1749 
1750 	tcp_v4_init();
1751 
1752 	/* Setup TCP slab cache for open requests. */
1753 	tcp_init();
1754 
1755 	/* Setup UDP memory threshold */
1756 	udp_init();
1757 
1758 	/* Add UDP-Lite (RFC 3828) */
1759 	udplite4_register();
1760 
1761 	ping_init();
1762 
1763 	/*
1764 	 *	Set the ICMP layer up
1765 	 */
1766 
1767 	if (icmp_init() < 0)
1768 		panic("Failed to create the ICMP control socket.\n");
1769 
1770 	/*
1771 	 *	Initialise the multicast router
1772 	 */
1773 #if defined(CONFIG_IP_MROUTE)
1774 	if (ip_mr_init())
1775 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1776 #endif
1777 	/*
1778 	 *	Initialise per-cpu ipv4 mibs
1779 	 */
1780 
1781 	if (init_ipv4_mibs())
1782 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1783 
1784 	ipv4_proc_init();
1785 
1786 	ipfrag_init();
1787 
1788 	dev_add_pack(&ip_packet_type);
1789 
1790 	rc = 0;
1791 out:
1792 	return rc;
1793 out_unregister_raw_proto:
1794 	proto_unregister(&raw_prot);
1795 out_unregister_udp_proto:
1796 	proto_unregister(&udp_prot);
1797 out_unregister_tcp_proto:
1798 	proto_unregister(&tcp_prot);
1799 out_free_reserved_ports:
1800 	kfree(sysctl_local_reserved_ports);
1801 	goto out;
1802 }
1803 
1804 fs_initcall(inet_init);
1805 
1806 /* ------------------------------------------------------------------------ */
1807 
1808 #ifdef CONFIG_PROC_FS
1809 static int __init ipv4_proc_init(void)
1810 {
1811 	int rc = 0;
1812 
1813 	if (raw_proc_init())
1814 		goto out_raw;
1815 	if (tcp4_proc_init())
1816 		goto out_tcp;
1817 	if (udp4_proc_init())
1818 		goto out_udp;
1819 	if (ping_proc_init())
1820 		goto out_ping;
1821 	if (ip_misc_proc_init())
1822 		goto out_misc;
1823 out:
1824 	return rc;
1825 out_misc:
1826 	ping_proc_exit();
1827 out_ping:
1828 	udp4_proc_exit();
1829 out_udp:
1830 	tcp4_proc_exit();
1831 out_tcp:
1832 	raw_proc_exit();
1833 out_raw:
1834 	rc = -ENOMEM;
1835 	goto out;
1836 }
1837 
1838 #else /* CONFIG_PROC_FS */
1839 static int __init ipv4_proc_init(void)
1840 {
1841 	return 0;
1842 }
1843 #endif /* CONFIG_PROC_FS */
1844 
1845 MODULE_ALIAS_NETPROTO(PF_INET);
1846 
1847