xref: /openbmc/linux/net/ipv4/af_inet.c (revision 174cd4b1)
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/kmod.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 <linux/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/ip_tunnels.h>
116 #include <net/xfrm.h>
117 #include <net/net_namespace.h>
118 #include <net/secure_seq.h>
119 #ifdef CONFIG_IP_MROUTE
120 #include <linux/mroute.h>
121 #endif
122 #include <net/l3mdev.h>
123 
124 
125 /* The inetsw table contains everything that inet_create needs to
126  * build a new socket.
127  */
128 static struct list_head inetsw[SOCK_MAX];
129 static DEFINE_SPINLOCK(inetsw_lock);
130 
131 /* New destruction routine */
132 
133 void inet_sock_destruct(struct sock *sk)
134 {
135 	struct inet_sock *inet = inet_sk(sk);
136 
137 	__skb_queue_purge(&sk->sk_receive_queue);
138 	__skb_queue_purge(&sk->sk_error_queue);
139 
140 	sk_mem_reclaim(sk);
141 
142 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
143 		pr_err("Attempt to release TCP socket in state %d %p\n",
144 		       sk->sk_state, sk);
145 		return;
146 	}
147 	if (!sock_flag(sk, SOCK_DEAD)) {
148 		pr_err("Attempt to release alive inet socket %p\n", sk);
149 		return;
150 	}
151 
152 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
153 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
154 	WARN_ON(sk->sk_wmem_queued);
155 	WARN_ON(sk->sk_forward_alloc);
156 
157 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
158 	dst_release(rcu_dereference_check(sk->sk_dst_cache, 1));
159 	dst_release(sk->sk_rx_dst);
160 	sk_refcnt_debug_dec(sk);
161 }
162 EXPORT_SYMBOL(inet_sock_destruct);
163 
164 /*
165  *	The routines beyond this point handle the behaviour of an AF_INET
166  *	socket object. Mostly it punts to the subprotocols of IP to do
167  *	the work.
168  */
169 
170 /*
171  *	Automatically bind an unbound socket.
172  */
173 
174 static int inet_autobind(struct sock *sk)
175 {
176 	struct inet_sock *inet;
177 	/* We may need to bind the socket. */
178 	lock_sock(sk);
179 	inet = inet_sk(sk);
180 	if (!inet->inet_num) {
181 		if (sk->sk_prot->get_port(sk, 0)) {
182 			release_sock(sk);
183 			return -EAGAIN;
184 		}
185 		inet->inet_sport = htons(inet->inet_num);
186 	}
187 	release_sock(sk);
188 	return 0;
189 }
190 
191 /*
192  *	Move a socket into listening state.
193  */
194 int inet_listen(struct socket *sock, int backlog)
195 {
196 	struct sock *sk = sock->sk;
197 	unsigned char old_state;
198 	int err;
199 
200 	lock_sock(sk);
201 
202 	err = -EINVAL;
203 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
204 		goto out;
205 
206 	old_state = sk->sk_state;
207 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
208 		goto out;
209 
210 	/* Really, if the socket is already in listen state
211 	 * we can only allow the backlog to be adjusted.
212 	 */
213 	if (old_state != TCP_LISTEN) {
214 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
215 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
216 		 * Also fastopen backlog may already been set via the option
217 		 * because the socket was in TCP_LISTEN state previously but
218 		 * was shutdown() rather than close().
219 		 */
220 		if ((sysctl_tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
221 		    (sysctl_tcp_fastopen & TFO_SERVER_ENABLE) &&
222 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
223 			fastopen_queue_tune(sk, backlog);
224 			tcp_fastopen_init_key_once(true);
225 		}
226 
227 		err = inet_csk_listen_start(sk, backlog);
228 		if (err)
229 			goto out;
230 	}
231 	sk->sk_max_ack_backlog = backlog;
232 	err = 0;
233 
234 out:
235 	release_sock(sk);
236 	return err;
237 }
238 EXPORT_SYMBOL(inet_listen);
239 
240 /*
241  *	Create an inet socket.
242  */
243 
244 static int inet_create(struct net *net, struct socket *sock, int protocol,
245 		       int kern)
246 {
247 	struct sock *sk;
248 	struct inet_protosw *answer;
249 	struct inet_sock *inet;
250 	struct proto *answer_prot;
251 	unsigned char answer_flags;
252 	int try_loading_module = 0;
253 	int err;
254 
255 	if (protocol < 0 || protocol >= IPPROTO_MAX)
256 		return -EINVAL;
257 
258 	sock->state = SS_UNCONNECTED;
259 
260 	/* Look for the requested type/protocol pair. */
261 lookup_protocol:
262 	err = -ESOCKTNOSUPPORT;
263 	rcu_read_lock();
264 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
265 
266 		err = 0;
267 		/* Check the non-wild match. */
268 		if (protocol == answer->protocol) {
269 			if (protocol != IPPROTO_IP)
270 				break;
271 		} else {
272 			/* Check for the two wild cases. */
273 			if (IPPROTO_IP == protocol) {
274 				protocol = answer->protocol;
275 				break;
276 			}
277 			if (IPPROTO_IP == answer->protocol)
278 				break;
279 		}
280 		err = -EPROTONOSUPPORT;
281 	}
282 
283 	if (unlikely(err)) {
284 		if (try_loading_module < 2) {
285 			rcu_read_unlock();
286 			/*
287 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
288 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
289 			 */
290 			if (++try_loading_module == 1)
291 				request_module("net-pf-%d-proto-%d-type-%d",
292 					       PF_INET, protocol, sock->type);
293 			/*
294 			 * Fall back to generic, e.g. net-pf-2-proto-132
295 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
296 			 */
297 			else
298 				request_module("net-pf-%d-proto-%d",
299 					       PF_INET, protocol);
300 			goto lookup_protocol;
301 		} else
302 			goto out_rcu_unlock;
303 	}
304 
305 	err = -EPERM;
306 	if (sock->type == SOCK_RAW && !kern &&
307 	    !ns_capable(net->user_ns, CAP_NET_RAW))
308 		goto out_rcu_unlock;
309 
310 	sock->ops = answer->ops;
311 	answer_prot = answer->prot;
312 	answer_flags = answer->flags;
313 	rcu_read_unlock();
314 
315 	WARN_ON(!answer_prot->slab);
316 
317 	err = -ENOBUFS;
318 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
319 	if (!sk)
320 		goto out;
321 
322 	err = 0;
323 	if (INET_PROTOSW_REUSE & answer_flags)
324 		sk->sk_reuse = SK_CAN_REUSE;
325 
326 	inet = inet_sk(sk);
327 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
328 
329 	inet->nodefrag = 0;
330 
331 	if (SOCK_RAW == sock->type) {
332 		inet->inet_num = protocol;
333 		if (IPPROTO_RAW == protocol)
334 			inet->hdrincl = 1;
335 	}
336 
337 	if (net->ipv4.sysctl_ip_no_pmtu_disc)
338 		inet->pmtudisc = IP_PMTUDISC_DONT;
339 	else
340 		inet->pmtudisc = IP_PMTUDISC_WANT;
341 
342 	inet->inet_id = 0;
343 
344 	sock_init_data(sock, sk);
345 
346 	sk->sk_destruct	   = inet_sock_destruct;
347 	sk->sk_protocol	   = protocol;
348 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
349 
350 	inet->uc_ttl	= -1;
351 	inet->mc_loop	= 1;
352 	inet->mc_ttl	= 1;
353 	inet->mc_all	= 1;
354 	inet->mc_index	= 0;
355 	inet->mc_list	= NULL;
356 	inet->rcv_tos	= 0;
357 
358 	sk_refcnt_debug_inc(sk);
359 
360 	if (inet->inet_num) {
361 		/* It assumes that any protocol which allows
362 		 * the user to assign a number at socket
363 		 * creation time automatically
364 		 * shares.
365 		 */
366 		inet->inet_sport = htons(inet->inet_num);
367 		/* Add to protocol hash chains. */
368 		err = sk->sk_prot->hash(sk);
369 		if (err) {
370 			sk_common_release(sk);
371 			goto out;
372 		}
373 	}
374 
375 	if (sk->sk_prot->init) {
376 		err = sk->sk_prot->init(sk);
377 		if (err) {
378 			sk_common_release(sk);
379 			goto out;
380 		}
381 	}
382 
383 	if (!kern) {
384 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
385 		if (err) {
386 			sk_common_release(sk);
387 			goto out;
388 		}
389 	}
390 out:
391 	return err;
392 out_rcu_unlock:
393 	rcu_read_unlock();
394 	goto out;
395 }
396 
397 
398 /*
399  *	The peer socket should always be NULL (or else). When we call this
400  *	function we are destroying the object and from then on nobody
401  *	should refer to it.
402  */
403 int inet_release(struct socket *sock)
404 {
405 	struct sock *sk = sock->sk;
406 
407 	if (sk) {
408 		long timeout;
409 
410 		/* Applications forget to leave groups before exiting */
411 		ip_mc_drop_socket(sk);
412 
413 		/* If linger is set, we don't return until the close
414 		 * is complete.  Otherwise we return immediately. The
415 		 * actually closing is done the same either way.
416 		 *
417 		 * If the close is due to the process exiting, we never
418 		 * linger..
419 		 */
420 		timeout = 0;
421 		if (sock_flag(sk, SOCK_LINGER) &&
422 		    !(current->flags & PF_EXITING))
423 			timeout = sk->sk_lingertime;
424 		sock->sk = NULL;
425 		sk->sk_prot->close(sk, timeout);
426 	}
427 	return 0;
428 }
429 EXPORT_SYMBOL(inet_release);
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 	u32 tb_id = RT_TABLE_LOCAL;
440 	int err;
441 
442 	/* If the socket has its own bind function then use it. (RAW) */
443 	if (sk->sk_prot->bind) {
444 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
445 		goto out;
446 	}
447 	err = -EINVAL;
448 	if (addr_len < sizeof(struct sockaddr_in))
449 		goto out;
450 
451 	if (addr->sin_family != AF_INET) {
452 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
453 		 * only if s_addr is INADDR_ANY.
454 		 */
455 		err = -EAFNOSUPPORT;
456 		if (addr->sin_family != AF_UNSPEC ||
457 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
458 			goto out;
459 	}
460 
461 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
462 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
463 
464 	/* Not specified by any standard per-se, however it breaks too
465 	 * many applications when removed.  It is unfortunate since
466 	 * allowing applications to make a non-local bind solves
467 	 * several problems with systems using dynamic addressing.
468 	 * (ie. your servers still start up even if your ISDN link
469 	 *  is temporarily down)
470 	 */
471 	err = -EADDRNOTAVAIL;
472 	if (!net->ipv4.sysctl_ip_nonlocal_bind &&
473 	    !(inet->freebind || inet->transparent) &&
474 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
475 	    chk_addr_ret != RTN_LOCAL &&
476 	    chk_addr_ret != RTN_MULTICAST &&
477 	    chk_addr_ret != RTN_BROADCAST)
478 		goto out;
479 
480 	snum = ntohs(addr->sin_port);
481 	err = -EACCES;
482 	if (snum && snum < inet_prot_sock(net) &&
483 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
484 		goto out;
485 
486 	/*      We keep a pair of addresses. rcv_saddr is the one
487 	 *      used by hash lookups, and saddr is used for transmit.
488 	 *
489 	 *      In the BSD API these are the same except where it
490 	 *      would be illegal to use them (multicast/broadcast) in
491 	 *      which case the sending device address is used.
492 	 */
493 	lock_sock(sk);
494 
495 	/* Check these errors (active socket, double bind). */
496 	err = -EINVAL;
497 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
498 		goto out_release_sock;
499 
500 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
501 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
502 		inet->inet_saddr = 0;  /* Use device */
503 
504 	/* Make sure we are allowed to bind here. */
505 	if ((snum || !inet->bind_address_no_port) &&
506 	    sk->sk_prot->get_port(sk, snum)) {
507 		inet->inet_saddr = inet->inet_rcv_saddr = 0;
508 		err = -EADDRINUSE;
509 		goto out_release_sock;
510 	}
511 
512 	if (inet->inet_rcv_saddr)
513 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
514 	if (snum)
515 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
516 	inet->inet_sport = htons(inet->inet_num);
517 	inet->inet_daddr = 0;
518 	inet->inet_dport = 0;
519 	sk_dst_reset(sk);
520 	err = 0;
521 out_release_sock:
522 	release_sock(sk);
523 out:
524 	return err;
525 }
526 EXPORT_SYMBOL(inet_bind);
527 
528 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
529 		       int addr_len, int flags)
530 {
531 	struct sock *sk = sock->sk;
532 
533 	if (addr_len < sizeof(uaddr->sa_family))
534 		return -EINVAL;
535 	if (uaddr->sa_family == AF_UNSPEC)
536 		return sk->sk_prot->disconnect(sk, flags);
537 
538 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
539 		return -EAGAIN;
540 	return sk->sk_prot->connect(sk, uaddr, addr_len);
541 }
542 EXPORT_SYMBOL(inet_dgram_connect);
543 
544 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
545 {
546 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
547 
548 	add_wait_queue(sk_sleep(sk), &wait);
549 	sk->sk_write_pending += writebias;
550 
551 	/* Basic assumption: if someone sets sk->sk_err, he _must_
552 	 * change state of the socket from TCP_SYN_*.
553 	 * Connect() does not allow to get error notifications
554 	 * without closing the socket.
555 	 */
556 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
557 		release_sock(sk);
558 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
559 		lock_sock(sk);
560 		if (signal_pending(current) || !timeo)
561 			break;
562 	}
563 	remove_wait_queue(sk_sleep(sk), &wait);
564 	sk->sk_write_pending -= writebias;
565 	return timeo;
566 }
567 
568 /*
569  *	Connect to a remote host. There is regrettably still a little
570  *	TCP 'magic' in here.
571  */
572 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
573 			  int addr_len, int flags, int is_sendmsg)
574 {
575 	struct sock *sk = sock->sk;
576 	int err;
577 	long timeo;
578 
579 	/*
580 	 * uaddr can be NULL and addr_len can be 0 if:
581 	 * sk is a TCP fastopen active socket and
582 	 * TCP_FASTOPEN_CONNECT sockopt is set and
583 	 * we already have a valid cookie for this socket.
584 	 * In this case, user can call write() after connect().
585 	 * write() will invoke tcp_sendmsg_fastopen() which calls
586 	 * __inet_stream_connect().
587 	 */
588 	if (uaddr) {
589 		if (addr_len < sizeof(uaddr->sa_family))
590 			return -EINVAL;
591 
592 		if (uaddr->sa_family == AF_UNSPEC) {
593 			err = sk->sk_prot->disconnect(sk, flags);
594 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
595 			goto out;
596 		}
597 	}
598 
599 	switch (sock->state) {
600 	default:
601 		err = -EINVAL;
602 		goto out;
603 	case SS_CONNECTED:
604 		err = -EISCONN;
605 		goto out;
606 	case SS_CONNECTING:
607 		if (inet_sk(sk)->defer_connect)
608 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
609 		else
610 			err = -EALREADY;
611 		/* Fall out of switch with err, set for this state */
612 		break;
613 	case SS_UNCONNECTED:
614 		err = -EISCONN;
615 		if (sk->sk_state != TCP_CLOSE)
616 			goto out;
617 
618 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
619 		if (err < 0)
620 			goto out;
621 
622 		sock->state = SS_CONNECTING;
623 
624 		if (!err && inet_sk(sk)->defer_connect)
625 			goto out;
626 
627 		/* Just entered SS_CONNECTING state; the only
628 		 * difference is that return value in non-blocking
629 		 * case is EINPROGRESS, rather than EALREADY.
630 		 */
631 		err = -EINPROGRESS;
632 		break;
633 	}
634 
635 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
636 
637 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
638 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
639 				tcp_sk(sk)->fastopen_req &&
640 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
641 
642 		/* Error code is set above */
643 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
644 			goto out;
645 
646 		err = sock_intr_errno(timeo);
647 		if (signal_pending(current))
648 			goto out;
649 	}
650 
651 	/* Connection was closed by RST, timeout, ICMP error
652 	 * or another process disconnected us.
653 	 */
654 	if (sk->sk_state == TCP_CLOSE)
655 		goto sock_error;
656 
657 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
658 	 * and error was received after socket entered established state.
659 	 * Hence, it is handled normally after connect() return successfully.
660 	 */
661 
662 	sock->state = SS_CONNECTED;
663 	err = 0;
664 out:
665 	return err;
666 
667 sock_error:
668 	err = sock_error(sk) ? : -ECONNABORTED;
669 	sock->state = SS_UNCONNECTED;
670 	if (sk->sk_prot->disconnect(sk, flags))
671 		sock->state = SS_DISCONNECTING;
672 	goto out;
673 }
674 EXPORT_SYMBOL(__inet_stream_connect);
675 
676 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
677 			int addr_len, int flags)
678 {
679 	int err;
680 
681 	lock_sock(sock->sk);
682 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
683 	release_sock(sock->sk);
684 	return err;
685 }
686 EXPORT_SYMBOL(inet_stream_connect);
687 
688 /*
689  *	Accept a pending connection. The TCP layer now gives BSD semantics.
690  */
691 
692 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
693 {
694 	struct sock *sk1 = sock->sk;
695 	int err = -EINVAL;
696 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
697 
698 	if (!sk2)
699 		goto do_err;
700 
701 	lock_sock(sk2);
702 
703 	sock_rps_record_flow(sk2);
704 	WARN_ON(!((1 << sk2->sk_state) &
705 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
706 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
707 
708 	sock_graft(sk2, newsock);
709 
710 	newsock->state = SS_CONNECTED;
711 	err = 0;
712 	release_sock(sk2);
713 do_err:
714 	return err;
715 }
716 EXPORT_SYMBOL(inet_accept);
717 
718 
719 /*
720  *	This does both peername and sockname.
721  */
722 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
723 			int *uaddr_len, int peer)
724 {
725 	struct sock *sk		= sock->sk;
726 	struct inet_sock *inet	= inet_sk(sk);
727 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
728 
729 	sin->sin_family = AF_INET;
730 	if (peer) {
731 		if (!inet->inet_dport ||
732 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
733 		     peer == 1))
734 			return -ENOTCONN;
735 		sin->sin_port = inet->inet_dport;
736 		sin->sin_addr.s_addr = inet->inet_daddr;
737 	} else {
738 		__be32 addr = inet->inet_rcv_saddr;
739 		if (!addr)
740 			addr = inet->inet_saddr;
741 		sin->sin_port = inet->inet_sport;
742 		sin->sin_addr.s_addr = addr;
743 	}
744 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
745 	*uaddr_len = sizeof(*sin);
746 	return 0;
747 }
748 EXPORT_SYMBOL(inet_getname);
749 
750 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
751 {
752 	struct sock *sk = sock->sk;
753 
754 	sock_rps_record_flow(sk);
755 
756 	/* We may need to bind the socket. */
757 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
758 	    inet_autobind(sk))
759 		return -EAGAIN;
760 
761 	return sk->sk_prot->sendmsg(sk, msg, size);
762 }
763 EXPORT_SYMBOL(inet_sendmsg);
764 
765 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
766 		      size_t size, int flags)
767 {
768 	struct sock *sk = sock->sk;
769 
770 	sock_rps_record_flow(sk);
771 
772 	/* We may need to bind the socket. */
773 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
774 	    inet_autobind(sk))
775 		return -EAGAIN;
776 
777 	if (sk->sk_prot->sendpage)
778 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
779 	return sock_no_sendpage(sock, page, offset, size, flags);
780 }
781 EXPORT_SYMBOL(inet_sendpage);
782 
783 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
784 		 int flags)
785 {
786 	struct sock *sk = sock->sk;
787 	int addr_len = 0;
788 	int err;
789 
790 	sock_rps_record_flow(sk);
791 
792 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
793 				   flags & ~MSG_DONTWAIT, &addr_len);
794 	if (err >= 0)
795 		msg->msg_namelen = addr_len;
796 	return err;
797 }
798 EXPORT_SYMBOL(inet_recvmsg);
799 
800 int inet_shutdown(struct socket *sock, int how)
801 {
802 	struct sock *sk = sock->sk;
803 	int err = 0;
804 
805 	/* This should really check to make sure
806 	 * the socket is a TCP socket. (WHY AC...)
807 	 */
808 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
809 		       1->2 bit 2 snds.
810 		       2->3 */
811 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
812 		return -EINVAL;
813 
814 	lock_sock(sk);
815 	if (sock->state == SS_CONNECTING) {
816 		if ((1 << sk->sk_state) &
817 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
818 			sock->state = SS_DISCONNECTING;
819 		else
820 			sock->state = SS_CONNECTED;
821 	}
822 
823 	switch (sk->sk_state) {
824 	case TCP_CLOSE:
825 		err = -ENOTCONN;
826 		/* Hack to wake up other listeners, who can poll for
827 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
828 	default:
829 		sk->sk_shutdown |= how;
830 		if (sk->sk_prot->shutdown)
831 			sk->sk_prot->shutdown(sk, how);
832 		break;
833 
834 	/* Remaining two branches are temporary solution for missing
835 	 * close() in multithreaded environment. It is _not_ a good idea,
836 	 * but we have no choice until close() is repaired at VFS level.
837 	 */
838 	case TCP_LISTEN:
839 		if (!(how & RCV_SHUTDOWN))
840 			break;
841 		/* Fall through */
842 	case TCP_SYN_SENT:
843 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
844 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
845 		break;
846 	}
847 
848 	/* Wake up anyone sleeping in poll. */
849 	sk->sk_state_change(sk);
850 	release_sock(sk);
851 	return err;
852 }
853 EXPORT_SYMBOL(inet_shutdown);
854 
855 /*
856  *	ioctl() calls you can issue on an INET socket. Most of these are
857  *	device configuration and stuff and very rarely used. Some ioctls
858  *	pass on to the socket itself.
859  *
860  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
861  *	loads the devconfigure module does its configuring and unloads it.
862  *	There's a good 20K of config code hanging around the kernel.
863  */
864 
865 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
866 {
867 	struct sock *sk = sock->sk;
868 	int err = 0;
869 	struct net *net = sock_net(sk);
870 
871 	switch (cmd) {
872 	case SIOCGSTAMP:
873 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
874 		break;
875 	case SIOCGSTAMPNS:
876 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
877 		break;
878 	case SIOCADDRT:
879 	case SIOCDELRT:
880 	case SIOCRTMSG:
881 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
882 		break;
883 	case SIOCDARP:
884 	case SIOCGARP:
885 	case SIOCSARP:
886 		err = arp_ioctl(net, cmd, (void __user *)arg);
887 		break;
888 	case SIOCGIFADDR:
889 	case SIOCSIFADDR:
890 	case SIOCGIFBRDADDR:
891 	case SIOCSIFBRDADDR:
892 	case SIOCGIFNETMASK:
893 	case SIOCSIFNETMASK:
894 	case SIOCGIFDSTADDR:
895 	case SIOCSIFDSTADDR:
896 	case SIOCSIFPFLAGS:
897 	case SIOCGIFPFLAGS:
898 	case SIOCSIFFLAGS:
899 		err = devinet_ioctl(net, cmd, (void __user *)arg);
900 		break;
901 	default:
902 		if (sk->sk_prot->ioctl)
903 			err = sk->sk_prot->ioctl(sk, cmd, arg);
904 		else
905 			err = -ENOIOCTLCMD;
906 		break;
907 	}
908 	return err;
909 }
910 EXPORT_SYMBOL(inet_ioctl);
911 
912 #ifdef CONFIG_COMPAT
913 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
914 {
915 	struct sock *sk = sock->sk;
916 	int err = -ENOIOCTLCMD;
917 
918 	if (sk->sk_prot->compat_ioctl)
919 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
920 
921 	return err;
922 }
923 #endif
924 
925 const struct proto_ops inet_stream_ops = {
926 	.family		   = PF_INET,
927 	.owner		   = THIS_MODULE,
928 	.release	   = inet_release,
929 	.bind		   = inet_bind,
930 	.connect	   = inet_stream_connect,
931 	.socketpair	   = sock_no_socketpair,
932 	.accept		   = inet_accept,
933 	.getname	   = inet_getname,
934 	.poll		   = tcp_poll,
935 	.ioctl		   = inet_ioctl,
936 	.listen		   = inet_listen,
937 	.shutdown	   = inet_shutdown,
938 	.setsockopt	   = sock_common_setsockopt,
939 	.getsockopt	   = sock_common_getsockopt,
940 	.sendmsg	   = inet_sendmsg,
941 	.recvmsg	   = inet_recvmsg,
942 	.mmap		   = sock_no_mmap,
943 	.sendpage	   = inet_sendpage,
944 	.splice_read	   = tcp_splice_read,
945 	.read_sock	   = tcp_read_sock,
946 	.peek_len	   = tcp_peek_len,
947 #ifdef CONFIG_COMPAT
948 	.compat_setsockopt = compat_sock_common_setsockopt,
949 	.compat_getsockopt = compat_sock_common_getsockopt,
950 	.compat_ioctl	   = inet_compat_ioctl,
951 #endif
952 };
953 EXPORT_SYMBOL(inet_stream_ops);
954 
955 const struct proto_ops inet_dgram_ops = {
956 	.family		   = PF_INET,
957 	.owner		   = THIS_MODULE,
958 	.release	   = inet_release,
959 	.bind		   = inet_bind,
960 	.connect	   = inet_dgram_connect,
961 	.socketpair	   = sock_no_socketpair,
962 	.accept		   = sock_no_accept,
963 	.getname	   = inet_getname,
964 	.poll		   = udp_poll,
965 	.ioctl		   = inet_ioctl,
966 	.listen		   = sock_no_listen,
967 	.shutdown	   = inet_shutdown,
968 	.setsockopt	   = sock_common_setsockopt,
969 	.getsockopt	   = sock_common_getsockopt,
970 	.sendmsg	   = inet_sendmsg,
971 	.recvmsg	   = inet_recvmsg,
972 	.mmap		   = sock_no_mmap,
973 	.sendpage	   = inet_sendpage,
974 	.set_peek_off	   = sk_set_peek_off,
975 #ifdef CONFIG_COMPAT
976 	.compat_setsockopt = compat_sock_common_setsockopt,
977 	.compat_getsockopt = compat_sock_common_getsockopt,
978 	.compat_ioctl	   = inet_compat_ioctl,
979 #endif
980 };
981 EXPORT_SYMBOL(inet_dgram_ops);
982 
983 /*
984  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
985  * udp_poll
986  */
987 static const struct proto_ops inet_sockraw_ops = {
988 	.family		   = PF_INET,
989 	.owner		   = THIS_MODULE,
990 	.release	   = inet_release,
991 	.bind		   = inet_bind,
992 	.connect	   = inet_dgram_connect,
993 	.socketpair	   = sock_no_socketpair,
994 	.accept		   = sock_no_accept,
995 	.getname	   = inet_getname,
996 	.poll		   = datagram_poll,
997 	.ioctl		   = inet_ioctl,
998 	.listen		   = sock_no_listen,
999 	.shutdown	   = inet_shutdown,
1000 	.setsockopt	   = sock_common_setsockopt,
1001 	.getsockopt	   = sock_common_getsockopt,
1002 	.sendmsg	   = inet_sendmsg,
1003 	.recvmsg	   = inet_recvmsg,
1004 	.mmap		   = sock_no_mmap,
1005 	.sendpage	   = inet_sendpage,
1006 #ifdef CONFIG_COMPAT
1007 	.compat_setsockopt = compat_sock_common_setsockopt,
1008 	.compat_getsockopt = compat_sock_common_getsockopt,
1009 	.compat_ioctl	   = inet_compat_ioctl,
1010 #endif
1011 };
1012 
1013 static const struct net_proto_family inet_family_ops = {
1014 	.family = PF_INET,
1015 	.create = inet_create,
1016 	.owner	= THIS_MODULE,
1017 };
1018 
1019 /* Upon startup we insert all the elements in inetsw_array[] into
1020  * the linked list inetsw.
1021  */
1022 static struct inet_protosw inetsw_array[] =
1023 {
1024 	{
1025 		.type =       SOCK_STREAM,
1026 		.protocol =   IPPROTO_TCP,
1027 		.prot =       &tcp_prot,
1028 		.ops =        &inet_stream_ops,
1029 		.flags =      INET_PROTOSW_PERMANENT |
1030 			      INET_PROTOSW_ICSK,
1031 	},
1032 
1033 	{
1034 		.type =       SOCK_DGRAM,
1035 		.protocol =   IPPROTO_UDP,
1036 		.prot =       &udp_prot,
1037 		.ops =        &inet_dgram_ops,
1038 		.flags =      INET_PROTOSW_PERMANENT,
1039        },
1040 
1041        {
1042 		.type =       SOCK_DGRAM,
1043 		.protocol =   IPPROTO_ICMP,
1044 		.prot =       &ping_prot,
1045 		.ops =        &inet_dgram_ops,
1046 		.flags =      INET_PROTOSW_REUSE,
1047        },
1048 
1049        {
1050 	       .type =       SOCK_RAW,
1051 	       .protocol =   IPPROTO_IP,	/* wild card */
1052 	       .prot =       &raw_prot,
1053 	       .ops =        &inet_sockraw_ops,
1054 	       .flags =      INET_PROTOSW_REUSE,
1055        }
1056 };
1057 
1058 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1059 
1060 void inet_register_protosw(struct inet_protosw *p)
1061 {
1062 	struct list_head *lh;
1063 	struct inet_protosw *answer;
1064 	int protocol = p->protocol;
1065 	struct list_head *last_perm;
1066 
1067 	spin_lock_bh(&inetsw_lock);
1068 
1069 	if (p->type >= SOCK_MAX)
1070 		goto out_illegal;
1071 
1072 	/* If we are trying to override a permanent protocol, bail. */
1073 	last_perm = &inetsw[p->type];
1074 	list_for_each(lh, &inetsw[p->type]) {
1075 		answer = list_entry(lh, struct inet_protosw, list);
1076 		/* Check only the non-wild match. */
1077 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1078 			break;
1079 		if (protocol == answer->protocol)
1080 			goto out_permanent;
1081 		last_perm = lh;
1082 	}
1083 
1084 	/* Add the new entry after the last permanent entry if any, so that
1085 	 * the new entry does not override a permanent entry when matched with
1086 	 * a wild-card protocol. But it is allowed to override any existing
1087 	 * non-permanent entry.  This means that when we remove this entry, the
1088 	 * system automatically returns to the old behavior.
1089 	 */
1090 	list_add_rcu(&p->list, last_perm);
1091 out:
1092 	spin_unlock_bh(&inetsw_lock);
1093 
1094 	return;
1095 
1096 out_permanent:
1097 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1098 	goto out;
1099 
1100 out_illegal:
1101 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1102 	       p->type);
1103 	goto out;
1104 }
1105 EXPORT_SYMBOL(inet_register_protosw);
1106 
1107 void inet_unregister_protosw(struct inet_protosw *p)
1108 {
1109 	if (INET_PROTOSW_PERMANENT & p->flags) {
1110 		pr_err("Attempt to unregister permanent protocol %d\n",
1111 		       p->protocol);
1112 	} else {
1113 		spin_lock_bh(&inetsw_lock);
1114 		list_del_rcu(&p->list);
1115 		spin_unlock_bh(&inetsw_lock);
1116 
1117 		synchronize_net();
1118 	}
1119 }
1120 EXPORT_SYMBOL(inet_unregister_protosw);
1121 
1122 static int inet_sk_reselect_saddr(struct sock *sk)
1123 {
1124 	struct inet_sock *inet = inet_sk(sk);
1125 	__be32 old_saddr = inet->inet_saddr;
1126 	__be32 daddr = inet->inet_daddr;
1127 	struct flowi4 *fl4;
1128 	struct rtable *rt;
1129 	__be32 new_saddr;
1130 	struct ip_options_rcu *inet_opt;
1131 
1132 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1133 					     lockdep_sock_is_held(sk));
1134 	if (inet_opt && inet_opt->opt.srr)
1135 		daddr = inet_opt->opt.faddr;
1136 
1137 	/* Query new route. */
1138 	fl4 = &inet->cork.fl.u.ip4;
1139 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1140 			      sk->sk_bound_dev_if, sk->sk_protocol,
1141 			      inet->inet_sport, inet->inet_dport, sk);
1142 	if (IS_ERR(rt))
1143 		return PTR_ERR(rt);
1144 
1145 	sk_setup_caps(sk, &rt->dst);
1146 
1147 	new_saddr = fl4->saddr;
1148 
1149 	if (new_saddr == old_saddr)
1150 		return 0;
1151 
1152 	if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) {
1153 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1154 			__func__, &old_saddr, &new_saddr);
1155 	}
1156 
1157 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1158 
1159 	/*
1160 	 * XXX The only one ugly spot where we need to
1161 	 * XXX really change the sockets identity after
1162 	 * XXX it has entered the hashes. -DaveM
1163 	 *
1164 	 * Besides that, it does not check for connection
1165 	 * uniqueness. Wait for troubles.
1166 	 */
1167 	return __sk_prot_rehash(sk);
1168 }
1169 
1170 int inet_sk_rebuild_header(struct sock *sk)
1171 {
1172 	struct inet_sock *inet = inet_sk(sk);
1173 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1174 	__be32 daddr;
1175 	struct ip_options_rcu *inet_opt;
1176 	struct flowi4 *fl4;
1177 	int err;
1178 
1179 	/* Route is OK, nothing to do. */
1180 	if (rt)
1181 		return 0;
1182 
1183 	/* Reroute. */
1184 	rcu_read_lock();
1185 	inet_opt = rcu_dereference(inet->inet_opt);
1186 	daddr = inet->inet_daddr;
1187 	if (inet_opt && inet_opt->opt.srr)
1188 		daddr = inet_opt->opt.faddr;
1189 	rcu_read_unlock();
1190 	fl4 = &inet->cork.fl.u.ip4;
1191 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1192 				   inet->inet_dport, inet->inet_sport,
1193 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1194 				   sk->sk_bound_dev_if);
1195 	if (!IS_ERR(rt)) {
1196 		err = 0;
1197 		sk_setup_caps(sk, &rt->dst);
1198 	} else {
1199 		err = PTR_ERR(rt);
1200 
1201 		/* Routing failed... */
1202 		sk->sk_route_caps = 0;
1203 		/*
1204 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1205 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1206 		 */
1207 		if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr ||
1208 		    sk->sk_state != TCP_SYN_SENT ||
1209 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1210 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1211 			sk->sk_err_soft = -err;
1212 	}
1213 
1214 	return err;
1215 }
1216 EXPORT_SYMBOL(inet_sk_rebuild_header);
1217 
1218 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1219 				 netdev_features_t features)
1220 {
1221 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1222 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1223 	const struct net_offload *ops;
1224 	unsigned int offset = 0;
1225 	struct iphdr *iph;
1226 	int proto, tot_len;
1227 	int nhoff;
1228 	int ihl;
1229 	int id;
1230 
1231 	skb_reset_network_header(skb);
1232 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1233 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1234 		goto out;
1235 
1236 	iph = ip_hdr(skb);
1237 	ihl = iph->ihl * 4;
1238 	if (ihl < sizeof(*iph))
1239 		goto out;
1240 
1241 	id = ntohs(iph->id);
1242 	proto = iph->protocol;
1243 
1244 	/* Warning: after this point, iph might be no longer valid */
1245 	if (unlikely(!pskb_may_pull(skb, ihl)))
1246 		goto out;
1247 	__skb_pull(skb, ihl);
1248 
1249 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1250 	if (encap)
1251 		features &= skb->dev->hw_enc_features;
1252 	SKB_GSO_CB(skb)->encap_level += ihl;
1253 
1254 	skb_reset_transport_header(skb);
1255 
1256 	segs = ERR_PTR(-EPROTONOSUPPORT);
1257 
1258 	if (!skb->encapsulation || encap) {
1259 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1260 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1261 
1262 		/* fixed ID is invalid if DF bit is not set */
1263 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1264 			goto out;
1265 	}
1266 
1267 	ops = rcu_dereference(inet_offloads[proto]);
1268 	if (likely(ops && ops->callbacks.gso_segment))
1269 		segs = ops->callbacks.gso_segment(skb, features);
1270 
1271 	if (IS_ERR_OR_NULL(segs))
1272 		goto out;
1273 
1274 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1275 
1276 	skb = segs;
1277 	do {
1278 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1279 		if (udpfrag) {
1280 			iph->frag_off = htons(offset >> 3);
1281 			if (skb->next)
1282 				iph->frag_off |= htons(IP_MF);
1283 			offset += skb->len - nhoff - ihl;
1284 			tot_len = skb->len - nhoff;
1285 		} else if (skb_is_gso(skb)) {
1286 			if (!fixedid) {
1287 				iph->id = htons(id);
1288 				id += skb_shinfo(skb)->gso_segs;
1289 			}
1290 
1291 			if (gso_partial)
1292 				tot_len = skb_shinfo(skb)->gso_size +
1293 					  SKB_GSO_CB(skb)->data_offset +
1294 					  skb->head - (unsigned char *)iph;
1295 			else
1296 				tot_len = skb->len - nhoff;
1297 		} else {
1298 			if (!fixedid)
1299 				iph->id = htons(id++);
1300 			tot_len = skb->len - nhoff;
1301 		}
1302 		iph->tot_len = htons(tot_len);
1303 		ip_send_check(iph);
1304 		if (encap)
1305 			skb_reset_inner_headers(skb);
1306 		skb->network_header = (u8 *)iph - skb->head;
1307 	} while ((skb = skb->next));
1308 
1309 out:
1310 	return segs;
1311 }
1312 EXPORT_SYMBOL(inet_gso_segment);
1313 
1314 struct sk_buff **inet_gro_receive(struct sk_buff **head, struct sk_buff *skb)
1315 {
1316 	const struct net_offload *ops;
1317 	struct sk_buff **pp = NULL;
1318 	struct sk_buff *p;
1319 	const struct iphdr *iph;
1320 	unsigned int hlen;
1321 	unsigned int off;
1322 	unsigned int id;
1323 	int flush = 1;
1324 	int proto;
1325 
1326 	off = skb_gro_offset(skb);
1327 	hlen = off + sizeof(*iph);
1328 	iph = skb_gro_header_fast(skb, off);
1329 	if (skb_gro_header_hard(skb, hlen)) {
1330 		iph = skb_gro_header_slow(skb, hlen, off);
1331 		if (unlikely(!iph))
1332 			goto out;
1333 	}
1334 
1335 	proto = iph->protocol;
1336 
1337 	rcu_read_lock();
1338 	ops = rcu_dereference(inet_offloads[proto]);
1339 	if (!ops || !ops->callbacks.gro_receive)
1340 		goto out_unlock;
1341 
1342 	if (*(u8 *)iph != 0x45)
1343 		goto out_unlock;
1344 
1345 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1346 		goto out_unlock;
1347 
1348 	id = ntohl(*(__be32 *)&iph->id);
1349 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1350 	id >>= 16;
1351 
1352 	for (p = *head; p; p = p->next) {
1353 		struct iphdr *iph2;
1354 		u16 flush_id;
1355 
1356 		if (!NAPI_GRO_CB(p)->same_flow)
1357 			continue;
1358 
1359 		iph2 = (struct iphdr *)(p->data + off);
1360 		/* The above works because, with the exception of the top
1361 		 * (inner most) layer, we only aggregate pkts with the same
1362 		 * hdr length so all the hdrs we'll need to verify will start
1363 		 * at the same offset.
1364 		 */
1365 		if ((iph->protocol ^ iph2->protocol) |
1366 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1367 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1368 			NAPI_GRO_CB(p)->same_flow = 0;
1369 			continue;
1370 		}
1371 
1372 		/* All fields must match except length and checksum. */
1373 		NAPI_GRO_CB(p)->flush |=
1374 			(iph->ttl ^ iph2->ttl) |
1375 			(iph->tos ^ iph2->tos) |
1376 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1377 
1378 		NAPI_GRO_CB(p)->flush |= flush;
1379 
1380 		/* We need to store of the IP ID check to be included later
1381 		 * when we can verify that this packet does in fact belong
1382 		 * to a given flow.
1383 		 */
1384 		flush_id = (u16)(id - ntohs(iph2->id));
1385 
1386 		/* This bit of code makes it much easier for us to identify
1387 		 * the cases where we are doing atomic vs non-atomic IP ID
1388 		 * checks.  Specifically an atomic check can return IP ID
1389 		 * values 0 - 0xFFFF, while a non-atomic check can only
1390 		 * return 0 or 0xFFFF.
1391 		 */
1392 		if (!NAPI_GRO_CB(p)->is_atomic ||
1393 		    !(iph->frag_off & htons(IP_DF))) {
1394 			flush_id ^= NAPI_GRO_CB(p)->count;
1395 			flush_id = flush_id ? 0xFFFF : 0;
1396 		}
1397 
1398 		/* If the previous IP ID value was based on an atomic
1399 		 * datagram we can overwrite the value and ignore it.
1400 		 */
1401 		if (NAPI_GRO_CB(skb)->is_atomic)
1402 			NAPI_GRO_CB(p)->flush_id = flush_id;
1403 		else
1404 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1405 	}
1406 
1407 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1408 	NAPI_GRO_CB(skb)->flush |= flush;
1409 	skb_set_network_header(skb, off);
1410 	/* The above will be needed by the transport layer if there is one
1411 	 * immediately following this IP hdr.
1412 	 */
1413 
1414 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1415 	 * as we already checked checksum over ipv4 header was 0
1416 	 */
1417 	skb_gro_pull(skb, sizeof(*iph));
1418 	skb_set_transport_header(skb, skb_gro_offset(skb));
1419 
1420 	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
1421 
1422 out_unlock:
1423 	rcu_read_unlock();
1424 
1425 out:
1426 	skb_gro_flush_final(skb, pp, flush);
1427 
1428 	return pp;
1429 }
1430 EXPORT_SYMBOL(inet_gro_receive);
1431 
1432 static struct sk_buff **ipip_gro_receive(struct sk_buff **head,
1433 					 struct sk_buff *skb)
1434 {
1435 	if (NAPI_GRO_CB(skb)->encap_mark) {
1436 		NAPI_GRO_CB(skb)->flush = 1;
1437 		return NULL;
1438 	}
1439 
1440 	NAPI_GRO_CB(skb)->encap_mark = 1;
1441 
1442 	return inet_gro_receive(head, skb);
1443 }
1444 
1445 #define SECONDS_PER_DAY	86400
1446 
1447 /* inet_current_timestamp - Return IP network timestamp
1448  *
1449  * Return milliseconds since midnight in network byte order.
1450  */
1451 __be32 inet_current_timestamp(void)
1452 {
1453 	u32 secs;
1454 	u32 msecs;
1455 	struct timespec64 ts;
1456 
1457 	ktime_get_real_ts64(&ts);
1458 
1459 	/* Get secs since midnight. */
1460 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1461 	/* Convert to msecs. */
1462 	msecs = secs * MSEC_PER_SEC;
1463 	/* Convert nsec to msec. */
1464 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1465 
1466 	/* Convert to network byte order. */
1467 	return htonl(msecs);
1468 }
1469 EXPORT_SYMBOL(inet_current_timestamp);
1470 
1471 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1472 {
1473 	if (sk->sk_family == AF_INET)
1474 		return ip_recv_error(sk, msg, len, addr_len);
1475 #if IS_ENABLED(CONFIG_IPV6)
1476 	if (sk->sk_family == AF_INET6)
1477 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1478 #endif
1479 	return -EINVAL;
1480 }
1481 
1482 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1483 {
1484 	__be16 newlen = htons(skb->len - nhoff);
1485 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1486 	const struct net_offload *ops;
1487 	int proto = iph->protocol;
1488 	int err = -ENOSYS;
1489 
1490 	if (skb->encapsulation)
1491 		skb_set_inner_network_header(skb, nhoff);
1492 
1493 	csum_replace2(&iph->check, iph->tot_len, newlen);
1494 	iph->tot_len = newlen;
1495 
1496 	rcu_read_lock();
1497 	ops = rcu_dereference(inet_offloads[proto]);
1498 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1499 		goto out_unlock;
1500 
1501 	/* Only need to add sizeof(*iph) to get to the next hdr below
1502 	 * because any hdr with option will have been flushed in
1503 	 * inet_gro_receive().
1504 	 */
1505 	err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1506 
1507 out_unlock:
1508 	rcu_read_unlock();
1509 
1510 	return err;
1511 }
1512 EXPORT_SYMBOL(inet_gro_complete);
1513 
1514 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1515 {
1516 	skb->encapsulation = 1;
1517 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1518 	return inet_gro_complete(skb, nhoff);
1519 }
1520 
1521 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1522 			 unsigned short type, unsigned char protocol,
1523 			 struct net *net)
1524 {
1525 	struct socket *sock;
1526 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1527 
1528 	if (rc == 0) {
1529 		*sk = sock->sk;
1530 		(*sk)->sk_allocation = GFP_ATOMIC;
1531 		/*
1532 		 * Unhash it so that IP input processing does not even see it,
1533 		 * we do not wish this socket to see incoming packets.
1534 		 */
1535 		(*sk)->sk_prot->unhash(*sk);
1536 	}
1537 	return rc;
1538 }
1539 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1540 
1541 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1542 {
1543 	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1544 }
1545 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1546 
1547 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1548 {
1549 	unsigned long res = 0;
1550 	int i;
1551 
1552 	for_each_possible_cpu(i)
1553 		res += snmp_get_cpu_field(mib, i, offt);
1554 	return res;
1555 }
1556 EXPORT_SYMBOL_GPL(snmp_fold_field);
1557 
1558 #if BITS_PER_LONG==32
1559 
1560 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1561 			 size_t syncp_offset)
1562 {
1563 	void *bhptr;
1564 	struct u64_stats_sync *syncp;
1565 	u64 v;
1566 	unsigned int start;
1567 
1568 	bhptr = per_cpu_ptr(mib, cpu);
1569 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1570 	do {
1571 		start = u64_stats_fetch_begin_irq(syncp);
1572 		v = *(((u64 *)bhptr) + offt);
1573 	} while (u64_stats_fetch_retry_irq(syncp, start));
1574 
1575 	return v;
1576 }
1577 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1578 
1579 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1580 {
1581 	u64 res = 0;
1582 	int cpu;
1583 
1584 	for_each_possible_cpu(cpu) {
1585 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1586 	}
1587 	return res;
1588 }
1589 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1590 #endif
1591 
1592 #ifdef CONFIG_IP_MULTICAST
1593 static const struct net_protocol igmp_protocol = {
1594 	.handler =	igmp_rcv,
1595 	.netns_ok =	1,
1596 };
1597 #endif
1598 
1599 static const struct net_protocol tcp_protocol = {
1600 	.early_demux	=	tcp_v4_early_demux,
1601 	.handler	=	tcp_v4_rcv,
1602 	.err_handler	=	tcp_v4_err,
1603 	.no_policy	=	1,
1604 	.netns_ok	=	1,
1605 	.icmp_strict_tag_validation = 1,
1606 };
1607 
1608 static const struct net_protocol udp_protocol = {
1609 	.early_demux =	udp_v4_early_demux,
1610 	.handler =	udp_rcv,
1611 	.err_handler =	udp_err,
1612 	.no_policy =	1,
1613 	.netns_ok =	1,
1614 };
1615 
1616 static const struct net_protocol icmp_protocol = {
1617 	.handler =	icmp_rcv,
1618 	.err_handler =	icmp_err,
1619 	.no_policy =	1,
1620 	.netns_ok =	1,
1621 };
1622 
1623 static __net_init int ipv4_mib_init_net(struct net *net)
1624 {
1625 	int i;
1626 
1627 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1628 	if (!net->mib.tcp_statistics)
1629 		goto err_tcp_mib;
1630 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1631 	if (!net->mib.ip_statistics)
1632 		goto err_ip_mib;
1633 
1634 	for_each_possible_cpu(i) {
1635 		struct ipstats_mib *af_inet_stats;
1636 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1637 		u64_stats_init(&af_inet_stats->syncp);
1638 	}
1639 
1640 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1641 	if (!net->mib.net_statistics)
1642 		goto err_net_mib;
1643 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1644 	if (!net->mib.udp_statistics)
1645 		goto err_udp_mib;
1646 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1647 	if (!net->mib.udplite_statistics)
1648 		goto err_udplite_mib;
1649 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1650 	if (!net->mib.icmp_statistics)
1651 		goto err_icmp_mib;
1652 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1653 					      GFP_KERNEL);
1654 	if (!net->mib.icmpmsg_statistics)
1655 		goto err_icmpmsg_mib;
1656 
1657 	tcp_mib_init(net);
1658 	return 0;
1659 
1660 err_icmpmsg_mib:
1661 	free_percpu(net->mib.icmp_statistics);
1662 err_icmp_mib:
1663 	free_percpu(net->mib.udplite_statistics);
1664 err_udplite_mib:
1665 	free_percpu(net->mib.udp_statistics);
1666 err_udp_mib:
1667 	free_percpu(net->mib.net_statistics);
1668 err_net_mib:
1669 	free_percpu(net->mib.ip_statistics);
1670 err_ip_mib:
1671 	free_percpu(net->mib.tcp_statistics);
1672 err_tcp_mib:
1673 	return -ENOMEM;
1674 }
1675 
1676 static __net_exit void ipv4_mib_exit_net(struct net *net)
1677 {
1678 	kfree(net->mib.icmpmsg_statistics);
1679 	free_percpu(net->mib.icmp_statistics);
1680 	free_percpu(net->mib.udplite_statistics);
1681 	free_percpu(net->mib.udp_statistics);
1682 	free_percpu(net->mib.net_statistics);
1683 	free_percpu(net->mib.ip_statistics);
1684 	free_percpu(net->mib.tcp_statistics);
1685 }
1686 
1687 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1688 	.init = ipv4_mib_init_net,
1689 	.exit = ipv4_mib_exit_net,
1690 };
1691 
1692 static int __init init_ipv4_mibs(void)
1693 {
1694 	return register_pernet_subsys(&ipv4_mib_ops);
1695 }
1696 
1697 static __net_init int inet_init_net(struct net *net)
1698 {
1699 	/*
1700 	 * Set defaults for local port range
1701 	 */
1702 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1703 	net->ipv4.ip_local_ports.range[0] =  32768;
1704 	net->ipv4.ip_local_ports.range[1] =  60999;
1705 
1706 	seqlock_init(&net->ipv4.ping_group_range.lock);
1707 	/*
1708 	 * Sane defaults - nobody may create ping sockets.
1709 	 * Boot scripts should set this to distro-specific group.
1710 	 */
1711 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1712 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1713 
1714 	/* Default values for sysctl-controlled parameters.
1715 	 * We set them here, in case sysctl is not compiled.
1716 	 */
1717 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1718 	net->ipv4.sysctl_ip_dynaddr = 0;
1719 	net->ipv4.sysctl_ip_early_demux = 1;
1720 #ifdef CONFIG_SYSCTL
1721 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1722 #endif
1723 
1724 	return 0;
1725 }
1726 
1727 static __net_exit void inet_exit_net(struct net *net)
1728 {
1729 }
1730 
1731 static __net_initdata struct pernet_operations af_inet_ops = {
1732 	.init = inet_init_net,
1733 	.exit = inet_exit_net,
1734 };
1735 
1736 static int __init init_inet_pernet_ops(void)
1737 {
1738 	return register_pernet_subsys(&af_inet_ops);
1739 }
1740 
1741 static int ipv4_proc_init(void);
1742 
1743 /*
1744  *	IP protocol layer initialiser
1745  */
1746 
1747 static struct packet_offload ip_packet_offload __read_mostly = {
1748 	.type = cpu_to_be16(ETH_P_IP),
1749 	.callbacks = {
1750 		.gso_segment = inet_gso_segment,
1751 		.gro_receive = inet_gro_receive,
1752 		.gro_complete = inet_gro_complete,
1753 	},
1754 };
1755 
1756 static const struct net_offload ipip_offload = {
1757 	.callbacks = {
1758 		.gso_segment	= inet_gso_segment,
1759 		.gro_receive	= ipip_gro_receive,
1760 		.gro_complete	= ipip_gro_complete,
1761 	},
1762 };
1763 
1764 static int __init ipv4_offload_init(void)
1765 {
1766 	/*
1767 	 * Add offloads
1768 	 */
1769 	if (udpv4_offload_init() < 0)
1770 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1771 	if (tcpv4_offload_init() < 0)
1772 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1773 
1774 	dev_add_offload(&ip_packet_offload);
1775 	inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1776 	return 0;
1777 }
1778 
1779 fs_initcall(ipv4_offload_init);
1780 
1781 static struct packet_type ip_packet_type __read_mostly = {
1782 	.type = cpu_to_be16(ETH_P_IP),
1783 	.func = ip_rcv,
1784 };
1785 
1786 static int __init inet_init(void)
1787 {
1788 	struct inet_protosw *q;
1789 	struct list_head *r;
1790 	int rc = -EINVAL;
1791 
1792 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1793 
1794 	rc = proto_register(&tcp_prot, 1);
1795 	if (rc)
1796 		goto out;
1797 
1798 	rc = proto_register(&udp_prot, 1);
1799 	if (rc)
1800 		goto out_unregister_tcp_proto;
1801 
1802 	rc = proto_register(&raw_prot, 1);
1803 	if (rc)
1804 		goto out_unregister_udp_proto;
1805 
1806 	rc = proto_register(&ping_prot, 1);
1807 	if (rc)
1808 		goto out_unregister_raw_proto;
1809 
1810 	/*
1811 	 *	Tell SOCKET that we are alive...
1812 	 */
1813 
1814 	(void)sock_register(&inet_family_ops);
1815 
1816 #ifdef CONFIG_SYSCTL
1817 	ip_static_sysctl_init();
1818 #endif
1819 
1820 	/*
1821 	 *	Add all the base protocols.
1822 	 */
1823 
1824 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1825 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1826 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1827 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1828 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1829 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1830 #ifdef CONFIG_IP_MULTICAST
1831 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1832 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1833 #endif
1834 
1835 	/* Register the socket-side information for inet_create. */
1836 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1837 		INIT_LIST_HEAD(r);
1838 
1839 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1840 		inet_register_protosw(q);
1841 
1842 	/*
1843 	 *	Set the ARP module up
1844 	 */
1845 
1846 	arp_init();
1847 
1848 	/*
1849 	 *	Set the IP module up
1850 	 */
1851 
1852 	ip_init();
1853 
1854 	/* Setup TCP slab cache for open requests. */
1855 	tcp_init();
1856 
1857 	/* Setup UDP memory threshold */
1858 	udp_init();
1859 
1860 	/* Add UDP-Lite (RFC 3828) */
1861 	udplite4_register();
1862 
1863 	ping_init();
1864 
1865 	/*
1866 	 *	Set the ICMP layer up
1867 	 */
1868 
1869 	if (icmp_init() < 0)
1870 		panic("Failed to create the ICMP control socket.\n");
1871 
1872 	/*
1873 	 *	Initialise the multicast router
1874 	 */
1875 #if defined(CONFIG_IP_MROUTE)
1876 	if (ip_mr_init())
1877 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1878 #endif
1879 
1880 	if (init_inet_pernet_ops())
1881 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1882 	/*
1883 	 *	Initialise per-cpu ipv4 mibs
1884 	 */
1885 
1886 	if (init_ipv4_mibs())
1887 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1888 
1889 	ipv4_proc_init();
1890 
1891 	ipfrag_init();
1892 
1893 	dev_add_pack(&ip_packet_type);
1894 
1895 	ip_tunnel_core_init();
1896 
1897 	rc = 0;
1898 out:
1899 	return rc;
1900 out_unregister_raw_proto:
1901 	proto_unregister(&raw_prot);
1902 out_unregister_udp_proto:
1903 	proto_unregister(&udp_prot);
1904 out_unregister_tcp_proto:
1905 	proto_unregister(&tcp_prot);
1906 	goto out;
1907 }
1908 
1909 fs_initcall(inet_init);
1910 
1911 /* ------------------------------------------------------------------------ */
1912 
1913 #ifdef CONFIG_PROC_FS
1914 static int __init ipv4_proc_init(void)
1915 {
1916 	int rc = 0;
1917 
1918 	if (raw_proc_init())
1919 		goto out_raw;
1920 	if (tcp4_proc_init())
1921 		goto out_tcp;
1922 	if (udp4_proc_init())
1923 		goto out_udp;
1924 	if (ping_proc_init())
1925 		goto out_ping;
1926 	if (ip_misc_proc_init())
1927 		goto out_misc;
1928 out:
1929 	return rc;
1930 out_misc:
1931 	ping_proc_exit();
1932 out_ping:
1933 	udp4_proc_exit();
1934 out_udp:
1935 	tcp4_proc_exit();
1936 out_tcp:
1937 	raw_proc_exit();
1938 out_raw:
1939 	rc = -ENOMEM;
1940 	goto out;
1941 }
1942 
1943 #else /* CONFIG_PROC_FS */
1944 static int __init ipv4_proc_init(void)
1945 {
1946 	return 0;
1947 }
1948 #endif /* CONFIG_PROC_FS */
1949