xref: /openbmc/linux/net/ipv4/af_inet.c (revision 2891f2d5)
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 		bool kern)
694 {
695 	struct sock *sk1 = sock->sk;
696 	int err = -EINVAL;
697 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err, kern);
698 
699 	if (!sk2)
700 		goto do_err;
701 
702 	lock_sock(sk2);
703 
704 	sock_rps_record_flow(sk2);
705 	WARN_ON(!((1 << sk2->sk_state) &
706 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
707 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
708 
709 	sock_graft(sk2, newsock);
710 
711 	newsock->state = SS_CONNECTED;
712 	err = 0;
713 	release_sock(sk2);
714 do_err:
715 	return err;
716 }
717 EXPORT_SYMBOL(inet_accept);
718 
719 
720 /*
721  *	This does both peername and sockname.
722  */
723 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
724 			int *uaddr_len, int peer)
725 {
726 	struct sock *sk		= sock->sk;
727 	struct inet_sock *inet	= inet_sk(sk);
728 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
729 
730 	sin->sin_family = AF_INET;
731 	if (peer) {
732 		if (!inet->inet_dport ||
733 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
734 		     peer == 1))
735 			return -ENOTCONN;
736 		sin->sin_port = inet->inet_dport;
737 		sin->sin_addr.s_addr = inet->inet_daddr;
738 	} else {
739 		__be32 addr = inet->inet_rcv_saddr;
740 		if (!addr)
741 			addr = inet->inet_saddr;
742 		sin->sin_port = inet->inet_sport;
743 		sin->sin_addr.s_addr = addr;
744 	}
745 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
746 	*uaddr_len = sizeof(*sin);
747 	return 0;
748 }
749 EXPORT_SYMBOL(inet_getname);
750 
751 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
752 {
753 	struct sock *sk = sock->sk;
754 
755 	sock_rps_record_flow(sk);
756 
757 	/* We may need to bind the socket. */
758 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
759 	    inet_autobind(sk))
760 		return -EAGAIN;
761 
762 	return sk->sk_prot->sendmsg(sk, msg, size);
763 }
764 EXPORT_SYMBOL(inet_sendmsg);
765 
766 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
767 		      size_t size, int flags)
768 {
769 	struct sock *sk = sock->sk;
770 
771 	sock_rps_record_flow(sk);
772 
773 	/* We may need to bind the socket. */
774 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
775 	    inet_autobind(sk))
776 		return -EAGAIN;
777 
778 	if (sk->sk_prot->sendpage)
779 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
780 	return sock_no_sendpage(sock, page, offset, size, flags);
781 }
782 EXPORT_SYMBOL(inet_sendpage);
783 
784 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
785 		 int flags)
786 {
787 	struct sock *sk = sock->sk;
788 	int addr_len = 0;
789 	int err;
790 
791 	sock_rps_record_flow(sk);
792 
793 	err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
794 				   flags & ~MSG_DONTWAIT, &addr_len);
795 	if (err >= 0)
796 		msg->msg_namelen = addr_len;
797 	return err;
798 }
799 EXPORT_SYMBOL(inet_recvmsg);
800 
801 int inet_shutdown(struct socket *sock, int how)
802 {
803 	struct sock *sk = sock->sk;
804 	int err = 0;
805 
806 	/* This should really check to make sure
807 	 * the socket is a TCP socket. (WHY AC...)
808 	 */
809 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
810 		       1->2 bit 2 snds.
811 		       2->3 */
812 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
813 		return -EINVAL;
814 
815 	lock_sock(sk);
816 	if (sock->state == SS_CONNECTING) {
817 		if ((1 << sk->sk_state) &
818 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
819 			sock->state = SS_DISCONNECTING;
820 		else
821 			sock->state = SS_CONNECTED;
822 	}
823 
824 	switch (sk->sk_state) {
825 	case TCP_CLOSE:
826 		err = -ENOTCONN;
827 		/* Hack to wake up other listeners, who can poll for
828 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
829 	default:
830 		sk->sk_shutdown |= how;
831 		if (sk->sk_prot->shutdown)
832 			sk->sk_prot->shutdown(sk, how);
833 		break;
834 
835 	/* Remaining two branches are temporary solution for missing
836 	 * close() in multithreaded environment. It is _not_ a good idea,
837 	 * but we have no choice until close() is repaired at VFS level.
838 	 */
839 	case TCP_LISTEN:
840 		if (!(how & RCV_SHUTDOWN))
841 			break;
842 		/* Fall through */
843 	case TCP_SYN_SENT:
844 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
845 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
846 		break;
847 	}
848 
849 	/* Wake up anyone sleeping in poll. */
850 	sk->sk_state_change(sk);
851 	release_sock(sk);
852 	return err;
853 }
854 EXPORT_SYMBOL(inet_shutdown);
855 
856 /*
857  *	ioctl() calls you can issue on an INET socket. Most of these are
858  *	device configuration and stuff and very rarely used. Some ioctls
859  *	pass on to the socket itself.
860  *
861  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
862  *	loads the devconfigure module does its configuring and unloads it.
863  *	There's a good 20K of config code hanging around the kernel.
864  */
865 
866 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
867 {
868 	struct sock *sk = sock->sk;
869 	int err = 0;
870 	struct net *net = sock_net(sk);
871 
872 	switch (cmd) {
873 	case SIOCGSTAMP:
874 		err = sock_get_timestamp(sk, (struct timeval __user *)arg);
875 		break;
876 	case SIOCGSTAMPNS:
877 		err = sock_get_timestampns(sk, (struct timespec __user *)arg);
878 		break;
879 	case SIOCADDRT:
880 	case SIOCDELRT:
881 	case SIOCRTMSG:
882 		err = ip_rt_ioctl(net, cmd, (void __user *)arg);
883 		break;
884 	case SIOCDARP:
885 	case SIOCGARP:
886 	case SIOCSARP:
887 		err = arp_ioctl(net, cmd, (void __user *)arg);
888 		break;
889 	case SIOCGIFADDR:
890 	case SIOCSIFADDR:
891 	case SIOCGIFBRDADDR:
892 	case SIOCSIFBRDADDR:
893 	case SIOCGIFNETMASK:
894 	case SIOCSIFNETMASK:
895 	case SIOCGIFDSTADDR:
896 	case SIOCSIFDSTADDR:
897 	case SIOCSIFPFLAGS:
898 	case SIOCGIFPFLAGS:
899 	case SIOCSIFFLAGS:
900 		err = devinet_ioctl(net, cmd, (void __user *)arg);
901 		break;
902 	default:
903 		if (sk->sk_prot->ioctl)
904 			err = sk->sk_prot->ioctl(sk, cmd, arg);
905 		else
906 			err = -ENOIOCTLCMD;
907 		break;
908 	}
909 	return err;
910 }
911 EXPORT_SYMBOL(inet_ioctl);
912 
913 #ifdef CONFIG_COMPAT
914 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
915 {
916 	struct sock *sk = sock->sk;
917 	int err = -ENOIOCTLCMD;
918 
919 	if (sk->sk_prot->compat_ioctl)
920 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
921 
922 	return err;
923 }
924 #endif
925 
926 const struct proto_ops inet_stream_ops = {
927 	.family		   = PF_INET,
928 	.owner		   = THIS_MODULE,
929 	.release	   = inet_release,
930 	.bind		   = inet_bind,
931 	.connect	   = inet_stream_connect,
932 	.socketpair	   = sock_no_socketpair,
933 	.accept		   = inet_accept,
934 	.getname	   = inet_getname,
935 	.poll		   = tcp_poll,
936 	.ioctl		   = inet_ioctl,
937 	.listen		   = inet_listen,
938 	.shutdown	   = inet_shutdown,
939 	.setsockopt	   = sock_common_setsockopt,
940 	.getsockopt	   = sock_common_getsockopt,
941 	.sendmsg	   = inet_sendmsg,
942 	.recvmsg	   = inet_recvmsg,
943 	.mmap		   = sock_no_mmap,
944 	.sendpage	   = inet_sendpage,
945 	.splice_read	   = tcp_splice_read,
946 	.read_sock	   = tcp_read_sock,
947 	.peek_len	   = tcp_peek_len,
948 #ifdef CONFIG_COMPAT
949 	.compat_setsockopt = compat_sock_common_setsockopt,
950 	.compat_getsockopt = compat_sock_common_getsockopt,
951 	.compat_ioctl	   = inet_compat_ioctl,
952 #endif
953 };
954 EXPORT_SYMBOL(inet_stream_ops);
955 
956 const struct proto_ops inet_dgram_ops = {
957 	.family		   = PF_INET,
958 	.owner		   = THIS_MODULE,
959 	.release	   = inet_release,
960 	.bind		   = inet_bind,
961 	.connect	   = inet_dgram_connect,
962 	.socketpair	   = sock_no_socketpair,
963 	.accept		   = sock_no_accept,
964 	.getname	   = inet_getname,
965 	.poll		   = udp_poll,
966 	.ioctl		   = inet_ioctl,
967 	.listen		   = sock_no_listen,
968 	.shutdown	   = inet_shutdown,
969 	.setsockopt	   = sock_common_setsockopt,
970 	.getsockopt	   = sock_common_getsockopt,
971 	.sendmsg	   = inet_sendmsg,
972 	.recvmsg	   = inet_recvmsg,
973 	.mmap		   = sock_no_mmap,
974 	.sendpage	   = inet_sendpage,
975 	.set_peek_off	   = sk_set_peek_off,
976 #ifdef CONFIG_COMPAT
977 	.compat_setsockopt = compat_sock_common_setsockopt,
978 	.compat_getsockopt = compat_sock_common_getsockopt,
979 	.compat_ioctl	   = inet_compat_ioctl,
980 #endif
981 };
982 EXPORT_SYMBOL(inet_dgram_ops);
983 
984 /*
985  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
986  * udp_poll
987  */
988 static const struct proto_ops inet_sockraw_ops = {
989 	.family		   = PF_INET,
990 	.owner		   = THIS_MODULE,
991 	.release	   = inet_release,
992 	.bind		   = inet_bind,
993 	.connect	   = inet_dgram_connect,
994 	.socketpair	   = sock_no_socketpair,
995 	.accept		   = sock_no_accept,
996 	.getname	   = inet_getname,
997 	.poll		   = datagram_poll,
998 	.ioctl		   = inet_ioctl,
999 	.listen		   = sock_no_listen,
1000 	.shutdown	   = inet_shutdown,
1001 	.setsockopt	   = sock_common_setsockopt,
1002 	.getsockopt	   = sock_common_getsockopt,
1003 	.sendmsg	   = inet_sendmsg,
1004 	.recvmsg	   = inet_recvmsg,
1005 	.mmap		   = sock_no_mmap,
1006 	.sendpage	   = inet_sendpage,
1007 #ifdef CONFIG_COMPAT
1008 	.compat_setsockopt = compat_sock_common_setsockopt,
1009 	.compat_getsockopt = compat_sock_common_getsockopt,
1010 	.compat_ioctl	   = inet_compat_ioctl,
1011 #endif
1012 };
1013 
1014 static const struct net_proto_family inet_family_ops = {
1015 	.family = PF_INET,
1016 	.create = inet_create,
1017 	.owner	= THIS_MODULE,
1018 };
1019 
1020 /* Upon startup we insert all the elements in inetsw_array[] into
1021  * the linked list inetsw.
1022  */
1023 static struct inet_protosw inetsw_array[] =
1024 {
1025 	{
1026 		.type =       SOCK_STREAM,
1027 		.protocol =   IPPROTO_TCP,
1028 		.prot =       &tcp_prot,
1029 		.ops =        &inet_stream_ops,
1030 		.flags =      INET_PROTOSW_PERMANENT |
1031 			      INET_PROTOSW_ICSK,
1032 	},
1033 
1034 	{
1035 		.type =       SOCK_DGRAM,
1036 		.protocol =   IPPROTO_UDP,
1037 		.prot =       &udp_prot,
1038 		.ops =        &inet_dgram_ops,
1039 		.flags =      INET_PROTOSW_PERMANENT,
1040        },
1041 
1042        {
1043 		.type =       SOCK_DGRAM,
1044 		.protocol =   IPPROTO_ICMP,
1045 		.prot =       &ping_prot,
1046 		.ops =        &inet_dgram_ops,
1047 		.flags =      INET_PROTOSW_REUSE,
1048        },
1049 
1050        {
1051 	       .type =       SOCK_RAW,
1052 	       .protocol =   IPPROTO_IP,	/* wild card */
1053 	       .prot =       &raw_prot,
1054 	       .ops =        &inet_sockraw_ops,
1055 	       .flags =      INET_PROTOSW_REUSE,
1056        }
1057 };
1058 
1059 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1060 
1061 void inet_register_protosw(struct inet_protosw *p)
1062 {
1063 	struct list_head *lh;
1064 	struct inet_protosw *answer;
1065 	int protocol = p->protocol;
1066 	struct list_head *last_perm;
1067 
1068 	spin_lock_bh(&inetsw_lock);
1069 
1070 	if (p->type >= SOCK_MAX)
1071 		goto out_illegal;
1072 
1073 	/* If we are trying to override a permanent protocol, bail. */
1074 	last_perm = &inetsw[p->type];
1075 	list_for_each(lh, &inetsw[p->type]) {
1076 		answer = list_entry(lh, struct inet_protosw, list);
1077 		/* Check only the non-wild match. */
1078 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1079 			break;
1080 		if (protocol == answer->protocol)
1081 			goto out_permanent;
1082 		last_perm = lh;
1083 	}
1084 
1085 	/* Add the new entry after the last permanent entry if any, so that
1086 	 * the new entry does not override a permanent entry when matched with
1087 	 * a wild-card protocol. But it is allowed to override any existing
1088 	 * non-permanent entry.  This means that when we remove this entry, the
1089 	 * system automatically returns to the old behavior.
1090 	 */
1091 	list_add_rcu(&p->list, last_perm);
1092 out:
1093 	spin_unlock_bh(&inetsw_lock);
1094 
1095 	return;
1096 
1097 out_permanent:
1098 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1099 	goto out;
1100 
1101 out_illegal:
1102 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1103 	       p->type);
1104 	goto out;
1105 }
1106 EXPORT_SYMBOL(inet_register_protosw);
1107 
1108 void inet_unregister_protosw(struct inet_protosw *p)
1109 {
1110 	if (INET_PROTOSW_PERMANENT & p->flags) {
1111 		pr_err("Attempt to unregister permanent protocol %d\n",
1112 		       p->protocol);
1113 	} else {
1114 		spin_lock_bh(&inetsw_lock);
1115 		list_del_rcu(&p->list);
1116 		spin_unlock_bh(&inetsw_lock);
1117 
1118 		synchronize_net();
1119 	}
1120 }
1121 EXPORT_SYMBOL(inet_unregister_protosw);
1122 
1123 static int inet_sk_reselect_saddr(struct sock *sk)
1124 {
1125 	struct inet_sock *inet = inet_sk(sk);
1126 	__be32 old_saddr = inet->inet_saddr;
1127 	__be32 daddr = inet->inet_daddr;
1128 	struct flowi4 *fl4;
1129 	struct rtable *rt;
1130 	__be32 new_saddr;
1131 	struct ip_options_rcu *inet_opt;
1132 
1133 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1134 					     lockdep_sock_is_held(sk));
1135 	if (inet_opt && inet_opt->opt.srr)
1136 		daddr = inet_opt->opt.faddr;
1137 
1138 	/* Query new route. */
1139 	fl4 = &inet->cork.fl.u.ip4;
1140 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1141 			      sk->sk_bound_dev_if, sk->sk_protocol,
1142 			      inet->inet_sport, inet->inet_dport, sk);
1143 	if (IS_ERR(rt))
1144 		return PTR_ERR(rt);
1145 
1146 	sk_setup_caps(sk, &rt->dst);
1147 
1148 	new_saddr = fl4->saddr;
1149 
1150 	if (new_saddr == old_saddr)
1151 		return 0;
1152 
1153 	if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) {
1154 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1155 			__func__, &old_saddr, &new_saddr);
1156 	}
1157 
1158 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1159 
1160 	/*
1161 	 * XXX The only one ugly spot where we need to
1162 	 * XXX really change the sockets identity after
1163 	 * XXX it has entered the hashes. -DaveM
1164 	 *
1165 	 * Besides that, it does not check for connection
1166 	 * uniqueness. Wait for troubles.
1167 	 */
1168 	return __sk_prot_rehash(sk);
1169 }
1170 
1171 int inet_sk_rebuild_header(struct sock *sk)
1172 {
1173 	struct inet_sock *inet = inet_sk(sk);
1174 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1175 	__be32 daddr;
1176 	struct ip_options_rcu *inet_opt;
1177 	struct flowi4 *fl4;
1178 	int err;
1179 
1180 	/* Route is OK, nothing to do. */
1181 	if (rt)
1182 		return 0;
1183 
1184 	/* Reroute. */
1185 	rcu_read_lock();
1186 	inet_opt = rcu_dereference(inet->inet_opt);
1187 	daddr = inet->inet_daddr;
1188 	if (inet_opt && inet_opt->opt.srr)
1189 		daddr = inet_opt->opt.faddr;
1190 	rcu_read_unlock();
1191 	fl4 = &inet->cork.fl.u.ip4;
1192 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1193 				   inet->inet_dport, inet->inet_sport,
1194 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1195 				   sk->sk_bound_dev_if);
1196 	if (!IS_ERR(rt)) {
1197 		err = 0;
1198 		sk_setup_caps(sk, &rt->dst);
1199 	} else {
1200 		err = PTR_ERR(rt);
1201 
1202 		/* Routing failed... */
1203 		sk->sk_route_caps = 0;
1204 		/*
1205 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1206 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1207 		 */
1208 		if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr ||
1209 		    sk->sk_state != TCP_SYN_SENT ||
1210 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1211 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1212 			sk->sk_err_soft = -err;
1213 	}
1214 
1215 	return err;
1216 }
1217 EXPORT_SYMBOL(inet_sk_rebuild_header);
1218 
1219 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1220 				 netdev_features_t features)
1221 {
1222 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1223 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1224 	const struct net_offload *ops;
1225 	unsigned int offset = 0;
1226 	struct iphdr *iph;
1227 	int proto, tot_len;
1228 	int nhoff;
1229 	int ihl;
1230 	int id;
1231 
1232 	skb_reset_network_header(skb);
1233 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1234 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1235 		goto out;
1236 
1237 	iph = ip_hdr(skb);
1238 	ihl = iph->ihl * 4;
1239 	if (ihl < sizeof(*iph))
1240 		goto out;
1241 
1242 	id = ntohs(iph->id);
1243 	proto = iph->protocol;
1244 
1245 	/* Warning: after this point, iph might be no longer valid */
1246 	if (unlikely(!pskb_may_pull(skb, ihl)))
1247 		goto out;
1248 	__skb_pull(skb, ihl);
1249 
1250 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1251 	if (encap)
1252 		features &= skb->dev->hw_enc_features;
1253 	SKB_GSO_CB(skb)->encap_level += ihl;
1254 
1255 	skb_reset_transport_header(skb);
1256 
1257 	segs = ERR_PTR(-EPROTONOSUPPORT);
1258 
1259 	if (!skb->encapsulation || encap) {
1260 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1261 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1262 
1263 		/* fixed ID is invalid if DF bit is not set */
1264 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1265 			goto out;
1266 	}
1267 
1268 	ops = rcu_dereference(inet_offloads[proto]);
1269 	if (likely(ops && ops->callbacks.gso_segment))
1270 		segs = ops->callbacks.gso_segment(skb, features);
1271 
1272 	if (IS_ERR_OR_NULL(segs))
1273 		goto out;
1274 
1275 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1276 
1277 	skb = segs;
1278 	do {
1279 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1280 		if (udpfrag) {
1281 			iph->frag_off = htons(offset >> 3);
1282 			if (skb->next)
1283 				iph->frag_off |= htons(IP_MF);
1284 			offset += skb->len - nhoff - ihl;
1285 			tot_len = skb->len - nhoff;
1286 		} else if (skb_is_gso(skb)) {
1287 			if (!fixedid) {
1288 				iph->id = htons(id);
1289 				id += skb_shinfo(skb)->gso_segs;
1290 			}
1291 
1292 			if (gso_partial)
1293 				tot_len = skb_shinfo(skb)->gso_size +
1294 					  SKB_GSO_CB(skb)->data_offset +
1295 					  skb->head - (unsigned char *)iph;
1296 			else
1297 				tot_len = skb->len - nhoff;
1298 		} else {
1299 			if (!fixedid)
1300 				iph->id = htons(id++);
1301 			tot_len = skb->len - nhoff;
1302 		}
1303 		iph->tot_len = htons(tot_len);
1304 		ip_send_check(iph);
1305 		if (encap)
1306 			skb_reset_inner_headers(skb);
1307 		skb->network_header = (u8 *)iph - skb->head;
1308 	} while ((skb = skb->next));
1309 
1310 out:
1311 	return segs;
1312 }
1313 EXPORT_SYMBOL(inet_gso_segment);
1314 
1315 struct sk_buff **inet_gro_receive(struct sk_buff **head, struct sk_buff *skb)
1316 {
1317 	const struct net_offload *ops;
1318 	struct sk_buff **pp = NULL;
1319 	struct sk_buff *p;
1320 	const struct iphdr *iph;
1321 	unsigned int hlen;
1322 	unsigned int off;
1323 	unsigned int id;
1324 	int flush = 1;
1325 	int proto;
1326 
1327 	off = skb_gro_offset(skb);
1328 	hlen = off + sizeof(*iph);
1329 	iph = skb_gro_header_fast(skb, off);
1330 	if (skb_gro_header_hard(skb, hlen)) {
1331 		iph = skb_gro_header_slow(skb, hlen, off);
1332 		if (unlikely(!iph))
1333 			goto out;
1334 	}
1335 
1336 	proto = iph->protocol;
1337 
1338 	rcu_read_lock();
1339 	ops = rcu_dereference(inet_offloads[proto]);
1340 	if (!ops || !ops->callbacks.gro_receive)
1341 		goto out_unlock;
1342 
1343 	if (*(u8 *)iph != 0x45)
1344 		goto out_unlock;
1345 
1346 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1347 		goto out_unlock;
1348 
1349 	id = ntohl(*(__be32 *)&iph->id);
1350 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1351 	id >>= 16;
1352 
1353 	for (p = *head; p; p = p->next) {
1354 		struct iphdr *iph2;
1355 		u16 flush_id;
1356 
1357 		if (!NAPI_GRO_CB(p)->same_flow)
1358 			continue;
1359 
1360 		iph2 = (struct iphdr *)(p->data + off);
1361 		/* The above works because, with the exception of the top
1362 		 * (inner most) layer, we only aggregate pkts with the same
1363 		 * hdr length so all the hdrs we'll need to verify will start
1364 		 * at the same offset.
1365 		 */
1366 		if ((iph->protocol ^ iph2->protocol) |
1367 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1368 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1369 			NAPI_GRO_CB(p)->same_flow = 0;
1370 			continue;
1371 		}
1372 
1373 		/* All fields must match except length and checksum. */
1374 		NAPI_GRO_CB(p)->flush |=
1375 			(iph->ttl ^ iph2->ttl) |
1376 			(iph->tos ^ iph2->tos) |
1377 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1378 
1379 		NAPI_GRO_CB(p)->flush |= flush;
1380 
1381 		/* We need to store of the IP ID check to be included later
1382 		 * when we can verify that this packet does in fact belong
1383 		 * to a given flow.
1384 		 */
1385 		flush_id = (u16)(id - ntohs(iph2->id));
1386 
1387 		/* This bit of code makes it much easier for us to identify
1388 		 * the cases where we are doing atomic vs non-atomic IP ID
1389 		 * checks.  Specifically an atomic check can return IP ID
1390 		 * values 0 - 0xFFFF, while a non-atomic check can only
1391 		 * return 0 or 0xFFFF.
1392 		 */
1393 		if (!NAPI_GRO_CB(p)->is_atomic ||
1394 		    !(iph->frag_off & htons(IP_DF))) {
1395 			flush_id ^= NAPI_GRO_CB(p)->count;
1396 			flush_id = flush_id ? 0xFFFF : 0;
1397 		}
1398 
1399 		/* If the previous IP ID value was based on an atomic
1400 		 * datagram we can overwrite the value and ignore it.
1401 		 */
1402 		if (NAPI_GRO_CB(skb)->is_atomic)
1403 			NAPI_GRO_CB(p)->flush_id = flush_id;
1404 		else
1405 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1406 	}
1407 
1408 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1409 	NAPI_GRO_CB(skb)->flush |= flush;
1410 	skb_set_network_header(skb, off);
1411 	/* The above will be needed by the transport layer if there is one
1412 	 * immediately following this IP hdr.
1413 	 */
1414 
1415 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1416 	 * as we already checked checksum over ipv4 header was 0
1417 	 */
1418 	skb_gro_pull(skb, sizeof(*iph));
1419 	skb_set_transport_header(skb, skb_gro_offset(skb));
1420 
1421 	pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
1422 
1423 out_unlock:
1424 	rcu_read_unlock();
1425 
1426 out:
1427 	skb_gro_flush_final(skb, pp, flush);
1428 
1429 	return pp;
1430 }
1431 EXPORT_SYMBOL(inet_gro_receive);
1432 
1433 static struct sk_buff **ipip_gro_receive(struct sk_buff **head,
1434 					 struct sk_buff *skb)
1435 {
1436 	if (NAPI_GRO_CB(skb)->encap_mark) {
1437 		NAPI_GRO_CB(skb)->flush = 1;
1438 		return NULL;
1439 	}
1440 
1441 	NAPI_GRO_CB(skb)->encap_mark = 1;
1442 
1443 	return inet_gro_receive(head, skb);
1444 }
1445 
1446 #define SECONDS_PER_DAY	86400
1447 
1448 /* inet_current_timestamp - Return IP network timestamp
1449  *
1450  * Return milliseconds since midnight in network byte order.
1451  */
1452 __be32 inet_current_timestamp(void)
1453 {
1454 	u32 secs;
1455 	u32 msecs;
1456 	struct timespec64 ts;
1457 
1458 	ktime_get_real_ts64(&ts);
1459 
1460 	/* Get secs since midnight. */
1461 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1462 	/* Convert to msecs. */
1463 	msecs = secs * MSEC_PER_SEC;
1464 	/* Convert nsec to msec. */
1465 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1466 
1467 	/* Convert to network byte order. */
1468 	return htonl(msecs);
1469 }
1470 EXPORT_SYMBOL(inet_current_timestamp);
1471 
1472 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1473 {
1474 	if (sk->sk_family == AF_INET)
1475 		return ip_recv_error(sk, msg, len, addr_len);
1476 #if IS_ENABLED(CONFIG_IPV6)
1477 	if (sk->sk_family == AF_INET6)
1478 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1479 #endif
1480 	return -EINVAL;
1481 }
1482 
1483 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1484 {
1485 	__be16 newlen = htons(skb->len - nhoff);
1486 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1487 	const struct net_offload *ops;
1488 	int proto = iph->protocol;
1489 	int err = -ENOSYS;
1490 
1491 	if (skb->encapsulation) {
1492 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1493 		skb_set_inner_network_header(skb, nhoff);
1494 	}
1495 
1496 	csum_replace2(&iph->check, iph->tot_len, newlen);
1497 	iph->tot_len = newlen;
1498 
1499 	rcu_read_lock();
1500 	ops = rcu_dereference(inet_offloads[proto]);
1501 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1502 		goto out_unlock;
1503 
1504 	/* Only need to add sizeof(*iph) to get to the next hdr below
1505 	 * because any hdr with option will have been flushed in
1506 	 * inet_gro_receive().
1507 	 */
1508 	err = ops->callbacks.gro_complete(skb, nhoff + sizeof(*iph));
1509 
1510 out_unlock:
1511 	rcu_read_unlock();
1512 
1513 	return err;
1514 }
1515 EXPORT_SYMBOL(inet_gro_complete);
1516 
1517 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1518 {
1519 	skb->encapsulation = 1;
1520 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1521 	return inet_gro_complete(skb, nhoff);
1522 }
1523 
1524 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1525 			 unsigned short type, unsigned char protocol,
1526 			 struct net *net)
1527 {
1528 	struct socket *sock;
1529 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1530 
1531 	if (rc == 0) {
1532 		*sk = sock->sk;
1533 		(*sk)->sk_allocation = GFP_ATOMIC;
1534 		/*
1535 		 * Unhash it so that IP input processing does not even see it,
1536 		 * we do not wish this socket to see incoming packets.
1537 		 */
1538 		(*sk)->sk_prot->unhash(*sk);
1539 	}
1540 	return rc;
1541 }
1542 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1543 
1544 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1545 {
1546 	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1547 }
1548 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1549 
1550 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1551 {
1552 	unsigned long res = 0;
1553 	int i;
1554 
1555 	for_each_possible_cpu(i)
1556 		res += snmp_get_cpu_field(mib, i, offt);
1557 	return res;
1558 }
1559 EXPORT_SYMBOL_GPL(snmp_fold_field);
1560 
1561 #if BITS_PER_LONG==32
1562 
1563 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1564 			 size_t syncp_offset)
1565 {
1566 	void *bhptr;
1567 	struct u64_stats_sync *syncp;
1568 	u64 v;
1569 	unsigned int start;
1570 
1571 	bhptr = per_cpu_ptr(mib, cpu);
1572 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1573 	do {
1574 		start = u64_stats_fetch_begin_irq(syncp);
1575 		v = *(((u64 *)bhptr) + offt);
1576 	} while (u64_stats_fetch_retry_irq(syncp, start));
1577 
1578 	return v;
1579 }
1580 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1581 
1582 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1583 {
1584 	u64 res = 0;
1585 	int cpu;
1586 
1587 	for_each_possible_cpu(cpu) {
1588 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1589 	}
1590 	return res;
1591 }
1592 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1593 #endif
1594 
1595 #ifdef CONFIG_IP_MULTICAST
1596 static const struct net_protocol igmp_protocol = {
1597 	.handler =	igmp_rcv,
1598 	.netns_ok =	1,
1599 };
1600 #endif
1601 
1602 static struct net_protocol tcp_protocol = {
1603 	.early_demux	=	tcp_v4_early_demux,
1604 	.early_demux_handler =  tcp_v4_early_demux,
1605 	.handler	=	tcp_v4_rcv,
1606 	.err_handler	=	tcp_v4_err,
1607 	.no_policy	=	1,
1608 	.netns_ok	=	1,
1609 	.icmp_strict_tag_validation = 1,
1610 };
1611 
1612 static struct net_protocol udp_protocol = {
1613 	.early_demux =	udp_v4_early_demux,
1614 	.early_demux_handler =	udp_v4_early_demux,
1615 	.handler =	udp_rcv,
1616 	.err_handler =	udp_err,
1617 	.no_policy =	1,
1618 	.netns_ok =	1,
1619 };
1620 
1621 static const struct net_protocol icmp_protocol = {
1622 	.handler =	icmp_rcv,
1623 	.err_handler =	icmp_err,
1624 	.no_policy =	1,
1625 	.netns_ok =	1,
1626 };
1627 
1628 static __net_init int ipv4_mib_init_net(struct net *net)
1629 {
1630 	int i;
1631 
1632 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1633 	if (!net->mib.tcp_statistics)
1634 		goto err_tcp_mib;
1635 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1636 	if (!net->mib.ip_statistics)
1637 		goto err_ip_mib;
1638 
1639 	for_each_possible_cpu(i) {
1640 		struct ipstats_mib *af_inet_stats;
1641 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1642 		u64_stats_init(&af_inet_stats->syncp);
1643 	}
1644 
1645 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1646 	if (!net->mib.net_statistics)
1647 		goto err_net_mib;
1648 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1649 	if (!net->mib.udp_statistics)
1650 		goto err_udp_mib;
1651 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1652 	if (!net->mib.udplite_statistics)
1653 		goto err_udplite_mib;
1654 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1655 	if (!net->mib.icmp_statistics)
1656 		goto err_icmp_mib;
1657 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1658 					      GFP_KERNEL);
1659 	if (!net->mib.icmpmsg_statistics)
1660 		goto err_icmpmsg_mib;
1661 
1662 	tcp_mib_init(net);
1663 	return 0;
1664 
1665 err_icmpmsg_mib:
1666 	free_percpu(net->mib.icmp_statistics);
1667 err_icmp_mib:
1668 	free_percpu(net->mib.udplite_statistics);
1669 err_udplite_mib:
1670 	free_percpu(net->mib.udp_statistics);
1671 err_udp_mib:
1672 	free_percpu(net->mib.net_statistics);
1673 err_net_mib:
1674 	free_percpu(net->mib.ip_statistics);
1675 err_ip_mib:
1676 	free_percpu(net->mib.tcp_statistics);
1677 err_tcp_mib:
1678 	return -ENOMEM;
1679 }
1680 
1681 static __net_exit void ipv4_mib_exit_net(struct net *net)
1682 {
1683 	kfree(net->mib.icmpmsg_statistics);
1684 	free_percpu(net->mib.icmp_statistics);
1685 	free_percpu(net->mib.udplite_statistics);
1686 	free_percpu(net->mib.udp_statistics);
1687 	free_percpu(net->mib.net_statistics);
1688 	free_percpu(net->mib.ip_statistics);
1689 	free_percpu(net->mib.tcp_statistics);
1690 }
1691 
1692 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1693 	.init = ipv4_mib_init_net,
1694 	.exit = ipv4_mib_exit_net,
1695 };
1696 
1697 static int __init init_ipv4_mibs(void)
1698 {
1699 	return register_pernet_subsys(&ipv4_mib_ops);
1700 }
1701 
1702 static __net_init int inet_init_net(struct net *net)
1703 {
1704 	/*
1705 	 * Set defaults for local port range
1706 	 */
1707 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1708 	net->ipv4.ip_local_ports.range[0] =  32768;
1709 	net->ipv4.ip_local_ports.range[1] =  60999;
1710 
1711 	seqlock_init(&net->ipv4.ping_group_range.lock);
1712 	/*
1713 	 * Sane defaults - nobody may create ping sockets.
1714 	 * Boot scripts should set this to distro-specific group.
1715 	 */
1716 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1717 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1718 
1719 	/* Default values for sysctl-controlled parameters.
1720 	 * We set them here, in case sysctl is not compiled.
1721 	 */
1722 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1723 	net->ipv4.sysctl_ip_dynaddr = 0;
1724 	net->ipv4.sysctl_ip_early_demux = 1;
1725 	net->ipv4.sysctl_udp_early_demux = 1;
1726 	net->ipv4.sysctl_tcp_early_demux = 1;
1727 #ifdef CONFIG_SYSCTL
1728 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1729 #endif
1730 
1731 	return 0;
1732 }
1733 
1734 static __net_exit void inet_exit_net(struct net *net)
1735 {
1736 }
1737 
1738 static __net_initdata struct pernet_operations af_inet_ops = {
1739 	.init = inet_init_net,
1740 	.exit = inet_exit_net,
1741 };
1742 
1743 static int __init init_inet_pernet_ops(void)
1744 {
1745 	return register_pernet_subsys(&af_inet_ops);
1746 }
1747 
1748 static int ipv4_proc_init(void);
1749 
1750 /*
1751  *	IP protocol layer initialiser
1752  */
1753 
1754 static struct packet_offload ip_packet_offload __read_mostly = {
1755 	.type = cpu_to_be16(ETH_P_IP),
1756 	.callbacks = {
1757 		.gso_segment = inet_gso_segment,
1758 		.gro_receive = inet_gro_receive,
1759 		.gro_complete = inet_gro_complete,
1760 	},
1761 };
1762 
1763 static const struct net_offload ipip_offload = {
1764 	.callbacks = {
1765 		.gso_segment	= inet_gso_segment,
1766 		.gro_receive	= ipip_gro_receive,
1767 		.gro_complete	= ipip_gro_complete,
1768 	},
1769 };
1770 
1771 static int __init ipv4_offload_init(void)
1772 {
1773 	/*
1774 	 * Add offloads
1775 	 */
1776 	if (udpv4_offload_init() < 0)
1777 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1778 	if (tcpv4_offload_init() < 0)
1779 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1780 
1781 	dev_add_offload(&ip_packet_offload);
1782 	inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1783 	return 0;
1784 }
1785 
1786 fs_initcall(ipv4_offload_init);
1787 
1788 static struct packet_type ip_packet_type __read_mostly = {
1789 	.type = cpu_to_be16(ETH_P_IP),
1790 	.func = ip_rcv,
1791 };
1792 
1793 static int __init inet_init(void)
1794 {
1795 	struct inet_protosw *q;
1796 	struct list_head *r;
1797 	int rc = -EINVAL;
1798 
1799 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1800 
1801 	rc = proto_register(&tcp_prot, 1);
1802 	if (rc)
1803 		goto out;
1804 
1805 	rc = proto_register(&udp_prot, 1);
1806 	if (rc)
1807 		goto out_unregister_tcp_proto;
1808 
1809 	rc = proto_register(&raw_prot, 1);
1810 	if (rc)
1811 		goto out_unregister_udp_proto;
1812 
1813 	rc = proto_register(&ping_prot, 1);
1814 	if (rc)
1815 		goto out_unregister_raw_proto;
1816 
1817 	/*
1818 	 *	Tell SOCKET that we are alive...
1819 	 */
1820 
1821 	(void)sock_register(&inet_family_ops);
1822 
1823 #ifdef CONFIG_SYSCTL
1824 	ip_static_sysctl_init();
1825 #endif
1826 
1827 	/*
1828 	 *	Add all the base protocols.
1829 	 */
1830 
1831 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1832 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1833 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1834 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1835 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1836 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1837 #ifdef CONFIG_IP_MULTICAST
1838 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1839 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1840 #endif
1841 
1842 	/* Register the socket-side information for inet_create. */
1843 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1844 		INIT_LIST_HEAD(r);
1845 
1846 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1847 		inet_register_protosw(q);
1848 
1849 	/*
1850 	 *	Set the ARP module up
1851 	 */
1852 
1853 	arp_init();
1854 
1855 	/*
1856 	 *	Set the IP module up
1857 	 */
1858 
1859 	ip_init();
1860 
1861 	/* Setup TCP slab cache for open requests. */
1862 	tcp_init();
1863 
1864 	/* Setup UDP memory threshold */
1865 	udp_init();
1866 
1867 	/* Add UDP-Lite (RFC 3828) */
1868 	udplite4_register();
1869 
1870 	ping_init();
1871 
1872 	/*
1873 	 *	Set the ICMP layer up
1874 	 */
1875 
1876 	if (icmp_init() < 0)
1877 		panic("Failed to create the ICMP control socket.\n");
1878 
1879 	/*
1880 	 *	Initialise the multicast router
1881 	 */
1882 #if defined(CONFIG_IP_MROUTE)
1883 	if (ip_mr_init())
1884 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
1885 #endif
1886 
1887 	if (init_inet_pernet_ops())
1888 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
1889 	/*
1890 	 *	Initialise per-cpu ipv4 mibs
1891 	 */
1892 
1893 	if (init_ipv4_mibs())
1894 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
1895 
1896 	ipv4_proc_init();
1897 
1898 	ipfrag_init();
1899 
1900 	dev_add_pack(&ip_packet_type);
1901 
1902 	ip_tunnel_core_init();
1903 
1904 	rc = 0;
1905 out:
1906 	return rc;
1907 out_unregister_raw_proto:
1908 	proto_unregister(&raw_prot);
1909 out_unregister_udp_proto:
1910 	proto_unregister(&udp_prot);
1911 out_unregister_tcp_proto:
1912 	proto_unregister(&tcp_prot);
1913 	goto out;
1914 }
1915 
1916 fs_initcall(inet_init);
1917 
1918 /* ------------------------------------------------------------------------ */
1919 
1920 #ifdef CONFIG_PROC_FS
1921 static int __init ipv4_proc_init(void)
1922 {
1923 	int rc = 0;
1924 
1925 	if (raw_proc_init())
1926 		goto out_raw;
1927 	if (tcp4_proc_init())
1928 		goto out_tcp;
1929 	if (udp4_proc_init())
1930 		goto out_udp;
1931 	if (ping_proc_init())
1932 		goto out_ping;
1933 	if (ip_misc_proc_init())
1934 		goto out_misc;
1935 out:
1936 	return rc;
1937 out_misc:
1938 	ping_proc_exit();
1939 out_ping:
1940 	udp4_proc_exit();
1941 out_udp:
1942 	tcp4_proc_exit();
1943 out_tcp:
1944 	raw_proc_exit();
1945 out_raw:
1946 	rc = -ENOMEM;
1947 	goto out;
1948 }
1949 
1950 #else /* CONFIG_PROC_FS */
1951 static int __init ipv4_proc_init(void)
1952 {
1953 	return 0;
1954 }
1955 #endif /* CONFIG_PROC_FS */
1956