xref: /linux/net/ipv4/af_inet.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		PF_INET protocol family socket handler.
8  *
9  * Authors:	Ross Biro
10  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11  *		Florian La Roche, <flla@stud.uni-sb.de>
12  *		Alan Cox, <A.Cox@swansea.ac.uk>
13  *
14  * Changes (see also sock.c)
15  *
16  *		piggy,
17  *		Karl Knutson	:	Socket protocol table
18  *		A.N.Kuznetsov	:	Socket death error in accept().
19  *		John Richardson :	Fix non blocking error in connect()
20  *					so sockets that fail to connect
21  *					don't return -EINPROGRESS.
22  *		Alan Cox	:	Asynchronous I/O support
23  *		Alan Cox	:	Keep correct socket pointer on sock
24  *					structures
25  *					when accept() ed
26  *		Alan Cox	:	Semantics of SO_LINGER aren't state
27  *					moved to close when you look carefully.
28  *					With this fixed and the accept bug fixed
29  *					some RPC stuff seems happier.
30  *		Niibe Yutaka	:	4.4BSD style write async I/O
31  *		Alan Cox,
32  *		Tony Gale 	:	Fixed reuse semantics.
33  *		Alan Cox	:	bind() shouldn't abort existing but dead
34  *					sockets. Stops FTP netin:.. I hope.
35  *		Alan Cox	:	bind() works correctly for RAW sockets.
36  *					Note that FreeBSD at least was broken
37  *					in this respect so be careful with
38  *					compatibility tests...
39  *		Alan Cox	:	routing cache support
40  *		Alan Cox	:	memzero the socket structure for
41  *					compactness.
42  *		Matt Day	:	nonblock connect error handler
43  *		Alan Cox	:	Allow large numbers of pending sockets
44  *					(eg for big web sites), but only if
45  *					specifically application requested.
46  *		Alan Cox	:	New buffering throughout IP. Used
47  *					dumbly.
48  *		Alan Cox	:	New buffering now used smartly.
49  *		Alan Cox	:	BSD rather than common sense
50  *					interpretation of listen.
51  *		Germano Caronni	:	Assorted small races.
52  *		Alan Cox	:	sendmsg/recvmsg basic support.
53  *		Alan Cox	:	Only sendmsg/recvmsg now supported.
54  *		Alan Cox	:	Locked down bind (see security list).
55  *		Alan Cox	:	Loosened bind a little.
56  *		Mike McLagan	:	ADD/DEL DLCI Ioctls
57  *	Willy Konynenberg	:	Transparent proxying support.
58  *		David S. Miller	:	New socket lookup architecture.
59  *					Some other random speedups.
60  *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
61  *		Andi Kleen	:	Fix inet_stream_connect TCP race.
62  */
63 
64 #define pr_fmt(fmt) "IPv4: " fmt
65 
66 #include <linux/err.h>
67 #include <linux/errno.h>
68 #include <linux/types.h>
69 #include <linux/socket.h>
70 #include <linux/in.h>
71 #include <linux/kernel.h>
72 #include <linux/kmod.h>
73 #include <linux/sched.h>
74 #include <linux/timer.h>
75 #include <linux/string.h>
76 #include <linux/sockios.h>
77 #include <linux/net.h>
78 #include <linux/capability.h>
79 #include <linux/fcntl.h>
80 #include <linux/mm.h>
81 #include <linux/interrupt.h>
82 #include <linux/stat.h>
83 #include <linux/init.h>
84 #include <linux/poll.h>
85 #include <linux/netfilter_ipv4.h>
86 #include <linux/random.h>
87 #include <linux/slab.h>
88 
89 #include <linux/uaccess.h>
90 
91 #include <linux/inet.h>
92 #include <linux/igmp.h>
93 #include <linux/inetdevice.h>
94 #include <linux/netdevice.h>
95 #include <net/checksum.h>
96 #include <net/ip.h>
97 #include <net/protocol.h>
98 #include <net/arp.h>
99 #include <net/route.h>
100 #include <net/ip_fib.h>
101 #include <net/inet_connection_sock.h>
102 #include <net/tcp.h>
103 #include <net/udp.h>
104 #include <net/udplite.h>
105 #include <net/ping.h>
106 #include <linux/skbuff.h>
107 #include <net/sock.h>
108 #include <net/raw.h>
109 #include <net/icmp.h>
110 #include <net/inet_common.h>
111 #include <net/ip_tunnels.h>
112 #include <net/xfrm.h>
113 #include <net/net_namespace.h>
114 #include <net/secure_seq.h>
115 #ifdef CONFIG_IP_MROUTE
116 #include <linux/mroute.h>
117 #endif
118 #include <net/l3mdev.h>
119 
120 #include <trace/events/sock.h>
121 
122 /* The inetsw table contains everything that inet_create needs to
123  * build a new socket.
124  */
125 static struct list_head inetsw[SOCK_MAX];
126 static DEFINE_SPINLOCK(inetsw_lock);
127 
128 /* New destruction routine */
129 
130 void inet_sock_destruct(struct sock *sk)
131 {
132 	struct inet_sock *inet = inet_sk(sk);
133 
134 	__skb_queue_purge(&sk->sk_receive_queue);
135 	if (sk->sk_rx_skb_cache) {
136 		__kfree_skb(sk->sk_rx_skb_cache);
137 		sk->sk_rx_skb_cache = NULL;
138 	}
139 	__skb_queue_purge(&sk->sk_error_queue);
140 
141 	sk_mem_reclaim(sk);
142 
143 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
144 		pr_err("Attempt to release TCP socket in state %d %p\n",
145 		       sk->sk_state, sk);
146 		return;
147 	}
148 	if (!sock_flag(sk, SOCK_DEAD)) {
149 		pr_err("Attempt to release alive inet socket %p\n", sk);
150 		return;
151 	}
152 
153 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
154 	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
155 	WARN_ON(sk->sk_wmem_queued);
156 	WARN_ON(sk->sk_forward_alloc);
157 
158 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
159 	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
160 	dst_release(sk->sk_rx_dst);
161 	sk_refcnt_debug_dec(sk);
162 }
163 EXPORT_SYMBOL(inet_sock_destruct);
164 
165 /*
166  *	The routines beyond this point handle the behaviour of an AF_INET
167  *	socket object. Mostly it punts to the subprotocols of IP to do
168  *	the work.
169  */
170 
171 /*
172  *	Automatically bind an unbound socket.
173  */
174 
175 static int inet_autobind(struct sock *sk)
176 {
177 	struct inet_sock *inet;
178 	/* We may need to bind the socket. */
179 	lock_sock(sk);
180 	inet = inet_sk(sk);
181 	if (!inet->inet_num) {
182 		if (sk->sk_prot->get_port(sk, 0)) {
183 			release_sock(sk);
184 			return -EAGAIN;
185 		}
186 		inet->inet_sport = htons(inet->inet_num);
187 	}
188 	release_sock(sk);
189 	return 0;
190 }
191 
192 /*
193  *	Move a socket into listening state.
194  */
195 int inet_listen(struct socket *sock, int backlog)
196 {
197 	struct sock *sk = sock->sk;
198 	unsigned char old_state;
199 	int err, tcp_fastopen;
200 
201 	lock_sock(sk);
202 
203 	err = -EINVAL;
204 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
205 		goto out;
206 
207 	old_state = sk->sk_state;
208 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
209 		goto out;
210 
211 	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
212 	/* Really, if the socket is already in listen state
213 	 * we can only allow the backlog to be adjusted.
214 	 */
215 	if (old_state != TCP_LISTEN) {
216 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
217 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
218 		 * Also fastopen backlog may already been set via the option
219 		 * because the socket was in TCP_LISTEN state previously but
220 		 * was shutdown() rather than close().
221 		 */
222 		tcp_fastopen = sock_net(sk)->ipv4.sysctl_tcp_fastopen;
223 		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
224 		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
225 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
226 			fastopen_queue_tune(sk, backlog);
227 			tcp_fastopen_init_key_once(sock_net(sk));
228 		}
229 
230 		err = inet_csk_listen_start(sk, backlog);
231 		if (err)
232 			goto out;
233 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
234 	}
235 	err = 0;
236 
237 out:
238 	release_sock(sk);
239 	return err;
240 }
241 EXPORT_SYMBOL(inet_listen);
242 
243 /*
244  *	Create an inet socket.
245  */
246 
247 static int inet_create(struct net *net, struct socket *sock, int protocol,
248 		       int kern)
249 {
250 	struct sock *sk;
251 	struct inet_protosw *answer;
252 	struct inet_sock *inet;
253 	struct proto *answer_prot;
254 	unsigned char answer_flags;
255 	int try_loading_module = 0;
256 	int err;
257 
258 	if (protocol < 0 || protocol >= IPPROTO_MAX)
259 		return -EINVAL;
260 
261 	sock->state = SS_UNCONNECTED;
262 
263 	/* Look for the requested type/protocol pair. */
264 lookup_protocol:
265 	err = -ESOCKTNOSUPPORT;
266 	rcu_read_lock();
267 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
268 
269 		err = 0;
270 		/* Check the non-wild match. */
271 		if (protocol == answer->protocol) {
272 			if (protocol != IPPROTO_IP)
273 				break;
274 		} else {
275 			/* Check for the two wild cases. */
276 			if (IPPROTO_IP == protocol) {
277 				protocol = answer->protocol;
278 				break;
279 			}
280 			if (IPPROTO_IP == answer->protocol)
281 				break;
282 		}
283 		err = -EPROTONOSUPPORT;
284 	}
285 
286 	if (unlikely(err)) {
287 		if (try_loading_module < 2) {
288 			rcu_read_unlock();
289 			/*
290 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
291 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
292 			 */
293 			if (++try_loading_module == 1)
294 				request_module("net-pf-%d-proto-%d-type-%d",
295 					       PF_INET, protocol, sock->type);
296 			/*
297 			 * Fall back to generic, e.g. net-pf-2-proto-132
298 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
299 			 */
300 			else
301 				request_module("net-pf-%d-proto-%d",
302 					       PF_INET, protocol);
303 			goto lookup_protocol;
304 		} else
305 			goto out_rcu_unlock;
306 	}
307 
308 	err = -EPERM;
309 	if (sock->type == SOCK_RAW && !kern &&
310 	    !ns_capable(net->user_ns, CAP_NET_RAW))
311 		goto out_rcu_unlock;
312 
313 	sock->ops = answer->ops;
314 	answer_prot = answer->prot;
315 	answer_flags = answer->flags;
316 	rcu_read_unlock();
317 
318 	WARN_ON(!answer_prot->slab);
319 
320 	err = -ENOBUFS;
321 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
322 	if (!sk)
323 		goto out;
324 
325 	err = 0;
326 	if (INET_PROTOSW_REUSE & answer_flags)
327 		sk->sk_reuse = SK_CAN_REUSE;
328 
329 	inet = inet_sk(sk);
330 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
331 
332 	inet->nodefrag = 0;
333 
334 	if (SOCK_RAW == sock->type) {
335 		inet->inet_num = protocol;
336 		if (IPPROTO_RAW == protocol)
337 			inet->hdrincl = 1;
338 	}
339 
340 	if (net->ipv4.sysctl_ip_no_pmtu_disc)
341 		inet->pmtudisc = IP_PMTUDISC_DONT;
342 	else
343 		inet->pmtudisc = IP_PMTUDISC_WANT;
344 
345 	inet->inet_id = 0;
346 
347 	sock_init_data(sock, sk);
348 
349 	sk->sk_destruct	   = inet_sock_destruct;
350 	sk->sk_protocol	   = protocol;
351 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
352 
353 	inet->uc_ttl	= -1;
354 	inet->mc_loop	= 1;
355 	inet->mc_ttl	= 1;
356 	inet->mc_all	= 1;
357 	inet->mc_index	= 0;
358 	inet->mc_list	= NULL;
359 	inet->rcv_tos	= 0;
360 
361 	sk_refcnt_debug_inc(sk);
362 
363 	if (inet->inet_num) {
364 		/* It assumes that any protocol which allows
365 		 * the user to assign a number at socket
366 		 * creation time automatically
367 		 * shares.
368 		 */
369 		inet->inet_sport = htons(inet->inet_num);
370 		/* Add to protocol hash chains. */
371 		err = sk->sk_prot->hash(sk);
372 		if (err) {
373 			sk_common_release(sk);
374 			goto out;
375 		}
376 	}
377 
378 	if (sk->sk_prot->init) {
379 		err = sk->sk_prot->init(sk);
380 		if (err) {
381 			sk_common_release(sk);
382 			goto out;
383 		}
384 	}
385 
386 	if (!kern) {
387 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
388 		if (err) {
389 			sk_common_release(sk);
390 			goto out;
391 		}
392 	}
393 out:
394 	return err;
395 out_rcu_unlock:
396 	rcu_read_unlock();
397 	goto out;
398 }
399 
400 
401 /*
402  *	The peer socket should always be NULL (or else). When we call this
403  *	function we are destroying the object and from then on nobody
404  *	should refer to it.
405  */
406 int inet_release(struct socket *sock)
407 {
408 	struct sock *sk = sock->sk;
409 
410 	if (sk) {
411 		long timeout;
412 
413 		/* Applications forget to leave groups before exiting */
414 		ip_mc_drop_socket(sk);
415 
416 		/* If linger is set, we don't return until the close
417 		 * is complete.  Otherwise we return immediately. The
418 		 * actually closing is done the same either way.
419 		 *
420 		 * If the close is due to the process exiting, we never
421 		 * linger..
422 		 */
423 		timeout = 0;
424 		if (sock_flag(sk, SOCK_LINGER) &&
425 		    !(current->flags & PF_EXITING))
426 			timeout = sk->sk_lingertime;
427 		sk->sk_prot->close(sk, timeout);
428 		sock->sk = NULL;
429 	}
430 	return 0;
431 }
432 EXPORT_SYMBOL(inet_release);
433 
434 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
435 {
436 	struct sock *sk = sock->sk;
437 	int err;
438 
439 	/* If the socket has its own bind function then use it. (RAW) */
440 	if (sk->sk_prot->bind) {
441 		return sk->sk_prot->bind(sk, uaddr, addr_len);
442 	}
443 	if (addr_len < sizeof(struct sockaddr_in))
444 		return -EINVAL;
445 
446 	/* BPF prog is run before any checks are done so that if the prog
447 	 * changes context in a wrong way it will be caught.
448 	 */
449 	err = BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr);
450 	if (err)
451 		return err;
452 
453 	return __inet_bind(sk, uaddr, addr_len, false, true);
454 }
455 EXPORT_SYMBOL(inet_bind);
456 
457 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
458 		bool force_bind_address_no_port, bool with_lock)
459 {
460 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
461 	struct inet_sock *inet = inet_sk(sk);
462 	struct net *net = sock_net(sk);
463 	unsigned short snum;
464 	int chk_addr_ret;
465 	u32 tb_id = RT_TABLE_LOCAL;
466 	int err;
467 
468 	if (addr->sin_family != AF_INET) {
469 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
470 		 * only if s_addr is INADDR_ANY.
471 		 */
472 		err = -EAFNOSUPPORT;
473 		if (addr->sin_family != AF_UNSPEC ||
474 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
475 			goto out;
476 	}
477 
478 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
479 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
480 
481 	/* Not specified by any standard per-se, however it breaks too
482 	 * many applications when removed.  It is unfortunate since
483 	 * allowing applications to make a non-local bind solves
484 	 * several problems with systems using dynamic addressing.
485 	 * (ie. your servers still start up even if your ISDN link
486 	 *  is temporarily down)
487 	 */
488 	err = -EADDRNOTAVAIL;
489 	if (!inet_can_nonlocal_bind(net, inet) &&
490 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
491 	    chk_addr_ret != RTN_LOCAL &&
492 	    chk_addr_ret != RTN_MULTICAST &&
493 	    chk_addr_ret != RTN_BROADCAST)
494 		goto out;
495 
496 	snum = ntohs(addr->sin_port);
497 	err = -EACCES;
498 	if (snum && inet_port_requires_bind_service(net, snum) &&
499 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
500 		goto out;
501 
502 	/*      We keep a pair of addresses. rcv_saddr is the one
503 	 *      used by hash lookups, and saddr is used for transmit.
504 	 *
505 	 *      In the BSD API these are the same except where it
506 	 *      would be illegal to use them (multicast/broadcast) in
507 	 *      which case the sending device address is used.
508 	 */
509 	if (with_lock)
510 		lock_sock(sk);
511 
512 	/* Check these errors (active socket, double bind). */
513 	err = -EINVAL;
514 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
515 		goto out_release_sock;
516 
517 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
518 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
519 		inet->inet_saddr = 0;  /* Use device */
520 
521 	/* Make sure we are allowed to bind here. */
522 	if (snum || !(inet->bind_address_no_port ||
523 		      force_bind_address_no_port)) {
524 		if (sk->sk_prot->get_port(sk, snum)) {
525 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
526 			err = -EADDRINUSE;
527 			goto out_release_sock;
528 		}
529 		err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
530 		if (err) {
531 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
532 			goto out_release_sock;
533 		}
534 	}
535 
536 	if (inet->inet_rcv_saddr)
537 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
538 	if (snum)
539 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
540 	inet->inet_sport = htons(inet->inet_num);
541 	inet->inet_daddr = 0;
542 	inet->inet_dport = 0;
543 	sk_dst_reset(sk);
544 	err = 0;
545 out_release_sock:
546 	if (with_lock)
547 		release_sock(sk);
548 out:
549 	return err;
550 }
551 
552 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
553 		       int addr_len, int flags)
554 {
555 	struct sock *sk = sock->sk;
556 	int err;
557 
558 	if (addr_len < sizeof(uaddr->sa_family))
559 		return -EINVAL;
560 	if (uaddr->sa_family == AF_UNSPEC)
561 		return sk->sk_prot->disconnect(sk, flags);
562 
563 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
564 		err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
565 		if (err)
566 			return err;
567 	}
568 
569 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
570 		return -EAGAIN;
571 	return sk->sk_prot->connect(sk, uaddr, addr_len);
572 }
573 EXPORT_SYMBOL(inet_dgram_connect);
574 
575 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
576 {
577 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
578 
579 	add_wait_queue(sk_sleep(sk), &wait);
580 	sk->sk_write_pending += writebias;
581 
582 	/* Basic assumption: if someone sets sk->sk_err, he _must_
583 	 * change state of the socket from TCP_SYN_*.
584 	 * Connect() does not allow to get error notifications
585 	 * without closing the socket.
586 	 */
587 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
588 		release_sock(sk);
589 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
590 		lock_sock(sk);
591 		if (signal_pending(current) || !timeo)
592 			break;
593 	}
594 	remove_wait_queue(sk_sleep(sk), &wait);
595 	sk->sk_write_pending -= writebias;
596 	return timeo;
597 }
598 
599 /*
600  *	Connect to a remote host. There is regrettably still a little
601  *	TCP 'magic' in here.
602  */
603 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
604 			  int addr_len, int flags, int is_sendmsg)
605 {
606 	struct sock *sk = sock->sk;
607 	int err;
608 	long timeo;
609 
610 	/*
611 	 * uaddr can be NULL and addr_len can be 0 if:
612 	 * sk is a TCP fastopen active socket and
613 	 * TCP_FASTOPEN_CONNECT sockopt is set and
614 	 * we already have a valid cookie for this socket.
615 	 * In this case, user can call write() after connect().
616 	 * write() will invoke tcp_sendmsg_fastopen() which calls
617 	 * __inet_stream_connect().
618 	 */
619 	if (uaddr) {
620 		if (addr_len < sizeof(uaddr->sa_family))
621 			return -EINVAL;
622 
623 		if (uaddr->sa_family == AF_UNSPEC) {
624 			err = sk->sk_prot->disconnect(sk, flags);
625 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
626 			goto out;
627 		}
628 	}
629 
630 	switch (sock->state) {
631 	default:
632 		err = -EINVAL;
633 		goto out;
634 	case SS_CONNECTED:
635 		err = -EISCONN;
636 		goto out;
637 	case SS_CONNECTING:
638 		if (inet_sk(sk)->defer_connect)
639 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
640 		else
641 			err = -EALREADY;
642 		/* Fall out of switch with err, set for this state */
643 		break;
644 	case SS_UNCONNECTED:
645 		err = -EISCONN;
646 		if (sk->sk_state != TCP_CLOSE)
647 			goto out;
648 
649 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
650 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
651 			if (err)
652 				goto out;
653 		}
654 
655 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
656 		if (err < 0)
657 			goto out;
658 
659 		sock->state = SS_CONNECTING;
660 
661 		if (!err && inet_sk(sk)->defer_connect)
662 			goto out;
663 
664 		/* Just entered SS_CONNECTING state; the only
665 		 * difference is that return value in non-blocking
666 		 * case is EINPROGRESS, rather than EALREADY.
667 		 */
668 		err = -EINPROGRESS;
669 		break;
670 	}
671 
672 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
673 
674 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
675 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
676 				tcp_sk(sk)->fastopen_req &&
677 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
678 
679 		/* Error code is set above */
680 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
681 			goto out;
682 
683 		err = sock_intr_errno(timeo);
684 		if (signal_pending(current))
685 			goto out;
686 	}
687 
688 	/* Connection was closed by RST, timeout, ICMP error
689 	 * or another process disconnected us.
690 	 */
691 	if (sk->sk_state == TCP_CLOSE)
692 		goto sock_error;
693 
694 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
695 	 * and error was received after socket entered established state.
696 	 * Hence, it is handled normally after connect() return successfully.
697 	 */
698 
699 	sock->state = SS_CONNECTED;
700 	err = 0;
701 out:
702 	return err;
703 
704 sock_error:
705 	err = sock_error(sk) ? : -ECONNABORTED;
706 	sock->state = SS_UNCONNECTED;
707 	if (sk->sk_prot->disconnect(sk, flags))
708 		sock->state = SS_DISCONNECTING;
709 	goto out;
710 }
711 EXPORT_SYMBOL(__inet_stream_connect);
712 
713 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
714 			int addr_len, int flags)
715 {
716 	int err;
717 
718 	lock_sock(sock->sk);
719 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
720 	release_sock(sock->sk);
721 	return err;
722 }
723 EXPORT_SYMBOL(inet_stream_connect);
724 
725 /*
726  *	Accept a pending connection. The TCP layer now gives BSD semantics.
727  */
728 
729 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
730 		bool kern)
731 {
732 	struct sock *sk1 = sock->sk;
733 	int err = -EINVAL;
734 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err, kern);
735 
736 	if (!sk2)
737 		goto do_err;
738 
739 	lock_sock(sk2);
740 
741 	sock_rps_record_flow(sk2);
742 	WARN_ON(!((1 << sk2->sk_state) &
743 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
744 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
745 
746 	sock_graft(sk2, newsock);
747 
748 	newsock->state = SS_CONNECTED;
749 	err = 0;
750 	release_sock(sk2);
751 do_err:
752 	return err;
753 }
754 EXPORT_SYMBOL(inet_accept);
755 
756 
757 /*
758  *	This does both peername and sockname.
759  */
760 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
761 			int peer)
762 {
763 	struct sock *sk		= sock->sk;
764 	struct inet_sock *inet	= inet_sk(sk);
765 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
766 
767 	sin->sin_family = AF_INET;
768 	if (peer) {
769 		if (!inet->inet_dport ||
770 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
771 		     peer == 1))
772 			return -ENOTCONN;
773 		sin->sin_port = inet->inet_dport;
774 		sin->sin_addr.s_addr = inet->inet_daddr;
775 	} else {
776 		__be32 addr = inet->inet_rcv_saddr;
777 		if (!addr)
778 			addr = inet->inet_saddr;
779 		sin->sin_port = inet->inet_sport;
780 		sin->sin_addr.s_addr = addr;
781 	}
782 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
783 	return sizeof(*sin);
784 }
785 EXPORT_SYMBOL(inet_getname);
786 
787 int inet_send_prepare(struct sock *sk)
788 {
789 	sock_rps_record_flow(sk);
790 
791 	/* We may need to bind the socket. */
792 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
793 	    inet_autobind(sk))
794 		return -EAGAIN;
795 
796 	return 0;
797 }
798 EXPORT_SYMBOL_GPL(inet_send_prepare);
799 
800 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
801 {
802 	struct sock *sk = sock->sk;
803 
804 	if (unlikely(inet_send_prepare(sk)))
805 		return -EAGAIN;
806 
807 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
808 			       sk, msg, size);
809 }
810 EXPORT_SYMBOL(inet_sendmsg);
811 
812 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
813 		      size_t size, int flags)
814 {
815 	struct sock *sk = sock->sk;
816 
817 	if (unlikely(inet_send_prepare(sk)))
818 		return -EAGAIN;
819 
820 	if (sk->sk_prot->sendpage)
821 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
822 	return sock_no_sendpage(sock, page, offset, size, flags);
823 }
824 EXPORT_SYMBOL(inet_sendpage);
825 
826 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
827 					  size_t, int, int, int *));
828 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
829 		 int flags)
830 {
831 	struct sock *sk = sock->sk;
832 	int addr_len = 0;
833 	int err;
834 
835 	if (likely(!(flags & MSG_ERRQUEUE)))
836 		sock_rps_record_flow(sk);
837 
838 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
839 			      sk, msg, size, flags & MSG_DONTWAIT,
840 			      flags & ~MSG_DONTWAIT, &addr_len);
841 	if (err >= 0)
842 		msg->msg_namelen = addr_len;
843 	return err;
844 }
845 EXPORT_SYMBOL(inet_recvmsg);
846 
847 int inet_shutdown(struct socket *sock, int how)
848 {
849 	struct sock *sk = sock->sk;
850 	int err = 0;
851 
852 	/* This should really check to make sure
853 	 * the socket is a TCP socket. (WHY AC...)
854 	 */
855 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
856 		       1->2 bit 2 snds.
857 		       2->3 */
858 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
859 		return -EINVAL;
860 
861 	lock_sock(sk);
862 	if (sock->state == SS_CONNECTING) {
863 		if ((1 << sk->sk_state) &
864 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
865 			sock->state = SS_DISCONNECTING;
866 		else
867 			sock->state = SS_CONNECTED;
868 	}
869 
870 	switch (sk->sk_state) {
871 	case TCP_CLOSE:
872 		err = -ENOTCONN;
873 		/* Hack to wake up other listeners, who can poll for
874 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
875 		fallthrough;
876 	default:
877 		sk->sk_shutdown |= how;
878 		if (sk->sk_prot->shutdown)
879 			sk->sk_prot->shutdown(sk, how);
880 		break;
881 
882 	/* Remaining two branches are temporary solution for missing
883 	 * close() in multithreaded environment. It is _not_ a good idea,
884 	 * but we have no choice until close() is repaired at VFS level.
885 	 */
886 	case TCP_LISTEN:
887 		if (!(how & RCV_SHUTDOWN))
888 			break;
889 		fallthrough;
890 	case TCP_SYN_SENT:
891 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
892 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
893 		break;
894 	}
895 
896 	/* Wake up anyone sleeping in poll. */
897 	sk->sk_state_change(sk);
898 	release_sock(sk);
899 	return err;
900 }
901 EXPORT_SYMBOL(inet_shutdown);
902 
903 /*
904  *	ioctl() calls you can issue on an INET socket. Most of these are
905  *	device configuration and stuff and very rarely used. Some ioctls
906  *	pass on to the socket itself.
907  *
908  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
909  *	loads the devconfigure module does its configuring and unloads it.
910  *	There's a good 20K of config code hanging around the kernel.
911  */
912 
913 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
914 {
915 	struct sock *sk = sock->sk;
916 	int err = 0;
917 	struct net *net = sock_net(sk);
918 	void __user *p = (void __user *)arg;
919 	struct ifreq ifr;
920 	struct rtentry rt;
921 
922 	switch (cmd) {
923 	case SIOCADDRT:
924 	case SIOCDELRT:
925 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
926 			return -EFAULT;
927 		err = ip_rt_ioctl(net, cmd, &rt);
928 		break;
929 	case SIOCRTMSG:
930 		err = -EINVAL;
931 		break;
932 	case SIOCDARP:
933 	case SIOCGARP:
934 	case SIOCSARP:
935 		err = arp_ioctl(net, cmd, (void __user *)arg);
936 		break;
937 	case SIOCGIFADDR:
938 	case SIOCGIFBRDADDR:
939 	case SIOCGIFNETMASK:
940 	case SIOCGIFDSTADDR:
941 	case SIOCGIFPFLAGS:
942 		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
943 			return -EFAULT;
944 		err = devinet_ioctl(net, cmd, &ifr);
945 		if (!err && copy_to_user(p, &ifr, sizeof(struct ifreq)))
946 			err = -EFAULT;
947 		break;
948 
949 	case SIOCSIFADDR:
950 	case SIOCSIFBRDADDR:
951 	case SIOCSIFNETMASK:
952 	case SIOCSIFDSTADDR:
953 	case SIOCSIFPFLAGS:
954 	case SIOCSIFFLAGS:
955 		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
956 			return -EFAULT;
957 		err = devinet_ioctl(net, cmd, &ifr);
958 		break;
959 	default:
960 		if (sk->sk_prot->ioctl)
961 			err = sk->sk_prot->ioctl(sk, cmd, arg);
962 		else
963 			err = -ENOIOCTLCMD;
964 		break;
965 	}
966 	return err;
967 }
968 EXPORT_SYMBOL(inet_ioctl);
969 
970 #ifdef CONFIG_COMPAT
971 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
972 {
973 	struct sock *sk = sock->sk;
974 	int err = -ENOIOCTLCMD;
975 
976 	if (sk->sk_prot->compat_ioctl)
977 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
978 
979 	return err;
980 }
981 #endif
982 
983 const struct proto_ops inet_stream_ops = {
984 	.family		   = PF_INET,
985 	.owner		   = THIS_MODULE,
986 	.release	   = inet_release,
987 	.bind		   = inet_bind,
988 	.connect	   = inet_stream_connect,
989 	.socketpair	   = sock_no_socketpair,
990 	.accept		   = inet_accept,
991 	.getname	   = inet_getname,
992 	.poll		   = tcp_poll,
993 	.ioctl		   = inet_ioctl,
994 	.gettstamp	   = sock_gettstamp,
995 	.listen		   = inet_listen,
996 	.shutdown	   = inet_shutdown,
997 	.setsockopt	   = sock_common_setsockopt,
998 	.getsockopt	   = sock_common_getsockopt,
999 	.sendmsg	   = inet_sendmsg,
1000 	.recvmsg	   = inet_recvmsg,
1001 #ifdef CONFIG_MMU
1002 	.mmap		   = tcp_mmap,
1003 #endif
1004 	.sendpage	   = inet_sendpage,
1005 	.splice_read	   = tcp_splice_read,
1006 	.read_sock	   = tcp_read_sock,
1007 	.sendmsg_locked    = tcp_sendmsg_locked,
1008 	.sendpage_locked   = tcp_sendpage_locked,
1009 	.peek_len	   = tcp_peek_len,
1010 #ifdef CONFIG_COMPAT
1011 	.compat_setsockopt = compat_sock_common_setsockopt,
1012 	.compat_getsockopt = compat_sock_common_getsockopt,
1013 	.compat_ioctl	   = inet_compat_ioctl,
1014 #endif
1015 	.set_rcvlowat	   = tcp_set_rcvlowat,
1016 };
1017 EXPORT_SYMBOL(inet_stream_ops);
1018 
1019 const struct proto_ops inet_dgram_ops = {
1020 	.family		   = PF_INET,
1021 	.owner		   = THIS_MODULE,
1022 	.release	   = inet_release,
1023 	.bind		   = inet_bind,
1024 	.connect	   = inet_dgram_connect,
1025 	.socketpair	   = sock_no_socketpair,
1026 	.accept		   = sock_no_accept,
1027 	.getname	   = inet_getname,
1028 	.poll		   = udp_poll,
1029 	.ioctl		   = inet_ioctl,
1030 	.gettstamp	   = sock_gettstamp,
1031 	.listen		   = sock_no_listen,
1032 	.shutdown	   = inet_shutdown,
1033 	.setsockopt	   = sock_common_setsockopt,
1034 	.getsockopt	   = sock_common_getsockopt,
1035 	.sendmsg	   = inet_sendmsg,
1036 	.recvmsg	   = inet_recvmsg,
1037 	.mmap		   = sock_no_mmap,
1038 	.sendpage	   = inet_sendpage,
1039 	.set_peek_off	   = sk_set_peek_off,
1040 #ifdef CONFIG_COMPAT
1041 	.compat_setsockopt = compat_sock_common_setsockopt,
1042 	.compat_getsockopt = compat_sock_common_getsockopt,
1043 	.compat_ioctl	   = inet_compat_ioctl,
1044 #endif
1045 };
1046 EXPORT_SYMBOL(inet_dgram_ops);
1047 
1048 /*
1049  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1050  * udp_poll
1051  */
1052 static const struct proto_ops inet_sockraw_ops = {
1053 	.family		   = PF_INET,
1054 	.owner		   = THIS_MODULE,
1055 	.release	   = inet_release,
1056 	.bind		   = inet_bind,
1057 	.connect	   = inet_dgram_connect,
1058 	.socketpair	   = sock_no_socketpair,
1059 	.accept		   = sock_no_accept,
1060 	.getname	   = inet_getname,
1061 	.poll		   = datagram_poll,
1062 	.ioctl		   = inet_ioctl,
1063 	.gettstamp	   = sock_gettstamp,
1064 	.listen		   = sock_no_listen,
1065 	.shutdown	   = inet_shutdown,
1066 	.setsockopt	   = sock_common_setsockopt,
1067 	.getsockopt	   = sock_common_getsockopt,
1068 	.sendmsg	   = inet_sendmsg,
1069 	.recvmsg	   = inet_recvmsg,
1070 	.mmap		   = sock_no_mmap,
1071 	.sendpage	   = inet_sendpage,
1072 #ifdef CONFIG_COMPAT
1073 	.compat_setsockopt = compat_sock_common_setsockopt,
1074 	.compat_getsockopt = compat_sock_common_getsockopt,
1075 	.compat_ioctl	   = inet_compat_ioctl,
1076 #endif
1077 };
1078 
1079 static const struct net_proto_family inet_family_ops = {
1080 	.family = PF_INET,
1081 	.create = inet_create,
1082 	.owner	= THIS_MODULE,
1083 };
1084 
1085 /* Upon startup we insert all the elements in inetsw_array[] into
1086  * the linked list inetsw.
1087  */
1088 static struct inet_protosw inetsw_array[] =
1089 {
1090 	{
1091 		.type =       SOCK_STREAM,
1092 		.protocol =   IPPROTO_TCP,
1093 		.prot =       &tcp_prot,
1094 		.ops =        &inet_stream_ops,
1095 		.flags =      INET_PROTOSW_PERMANENT |
1096 			      INET_PROTOSW_ICSK,
1097 	},
1098 
1099 	{
1100 		.type =       SOCK_DGRAM,
1101 		.protocol =   IPPROTO_UDP,
1102 		.prot =       &udp_prot,
1103 		.ops =        &inet_dgram_ops,
1104 		.flags =      INET_PROTOSW_PERMANENT,
1105        },
1106 
1107        {
1108 		.type =       SOCK_DGRAM,
1109 		.protocol =   IPPROTO_ICMP,
1110 		.prot =       &ping_prot,
1111 		.ops =        &inet_sockraw_ops,
1112 		.flags =      INET_PROTOSW_REUSE,
1113        },
1114 
1115        {
1116 	       .type =       SOCK_RAW,
1117 	       .protocol =   IPPROTO_IP,	/* wild card */
1118 	       .prot =       &raw_prot,
1119 	       .ops =        &inet_sockraw_ops,
1120 	       .flags =      INET_PROTOSW_REUSE,
1121        }
1122 };
1123 
1124 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1125 
1126 void inet_register_protosw(struct inet_protosw *p)
1127 {
1128 	struct list_head *lh;
1129 	struct inet_protosw *answer;
1130 	int protocol = p->protocol;
1131 	struct list_head *last_perm;
1132 
1133 	spin_lock_bh(&inetsw_lock);
1134 
1135 	if (p->type >= SOCK_MAX)
1136 		goto out_illegal;
1137 
1138 	/* If we are trying to override a permanent protocol, bail. */
1139 	last_perm = &inetsw[p->type];
1140 	list_for_each(lh, &inetsw[p->type]) {
1141 		answer = list_entry(lh, struct inet_protosw, list);
1142 		/* Check only the non-wild match. */
1143 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1144 			break;
1145 		if (protocol == answer->protocol)
1146 			goto out_permanent;
1147 		last_perm = lh;
1148 	}
1149 
1150 	/* Add the new entry after the last permanent entry if any, so that
1151 	 * the new entry does not override a permanent entry when matched with
1152 	 * a wild-card protocol. But it is allowed to override any existing
1153 	 * non-permanent entry.  This means that when we remove this entry, the
1154 	 * system automatically returns to the old behavior.
1155 	 */
1156 	list_add_rcu(&p->list, last_perm);
1157 out:
1158 	spin_unlock_bh(&inetsw_lock);
1159 
1160 	return;
1161 
1162 out_permanent:
1163 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1164 	goto out;
1165 
1166 out_illegal:
1167 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1168 	       p->type);
1169 	goto out;
1170 }
1171 EXPORT_SYMBOL(inet_register_protosw);
1172 
1173 void inet_unregister_protosw(struct inet_protosw *p)
1174 {
1175 	if (INET_PROTOSW_PERMANENT & p->flags) {
1176 		pr_err("Attempt to unregister permanent protocol %d\n",
1177 		       p->protocol);
1178 	} else {
1179 		spin_lock_bh(&inetsw_lock);
1180 		list_del_rcu(&p->list);
1181 		spin_unlock_bh(&inetsw_lock);
1182 
1183 		synchronize_net();
1184 	}
1185 }
1186 EXPORT_SYMBOL(inet_unregister_protosw);
1187 
1188 static int inet_sk_reselect_saddr(struct sock *sk)
1189 {
1190 	struct inet_sock *inet = inet_sk(sk);
1191 	__be32 old_saddr = inet->inet_saddr;
1192 	__be32 daddr = inet->inet_daddr;
1193 	struct flowi4 *fl4;
1194 	struct rtable *rt;
1195 	__be32 new_saddr;
1196 	struct ip_options_rcu *inet_opt;
1197 
1198 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1199 					     lockdep_sock_is_held(sk));
1200 	if (inet_opt && inet_opt->opt.srr)
1201 		daddr = inet_opt->opt.faddr;
1202 
1203 	/* Query new route. */
1204 	fl4 = &inet->cork.fl.u.ip4;
1205 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1206 			      sk->sk_bound_dev_if, sk->sk_protocol,
1207 			      inet->inet_sport, inet->inet_dport, sk);
1208 	if (IS_ERR(rt))
1209 		return PTR_ERR(rt);
1210 
1211 	sk_setup_caps(sk, &rt->dst);
1212 
1213 	new_saddr = fl4->saddr;
1214 
1215 	if (new_saddr == old_saddr)
1216 		return 0;
1217 
1218 	if (sock_net(sk)->ipv4.sysctl_ip_dynaddr > 1) {
1219 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1220 			__func__, &old_saddr, &new_saddr);
1221 	}
1222 
1223 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1224 
1225 	/*
1226 	 * XXX The only one ugly spot where we need to
1227 	 * XXX really change the sockets identity after
1228 	 * XXX it has entered the hashes. -DaveM
1229 	 *
1230 	 * Besides that, it does not check for connection
1231 	 * uniqueness. Wait for troubles.
1232 	 */
1233 	return __sk_prot_rehash(sk);
1234 }
1235 
1236 int inet_sk_rebuild_header(struct sock *sk)
1237 {
1238 	struct inet_sock *inet = inet_sk(sk);
1239 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1240 	__be32 daddr;
1241 	struct ip_options_rcu *inet_opt;
1242 	struct flowi4 *fl4;
1243 	int err;
1244 
1245 	/* Route is OK, nothing to do. */
1246 	if (rt)
1247 		return 0;
1248 
1249 	/* Reroute. */
1250 	rcu_read_lock();
1251 	inet_opt = rcu_dereference(inet->inet_opt);
1252 	daddr = inet->inet_daddr;
1253 	if (inet_opt && inet_opt->opt.srr)
1254 		daddr = inet_opt->opt.faddr;
1255 	rcu_read_unlock();
1256 	fl4 = &inet->cork.fl.u.ip4;
1257 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1258 				   inet->inet_dport, inet->inet_sport,
1259 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1260 				   sk->sk_bound_dev_if);
1261 	if (!IS_ERR(rt)) {
1262 		err = 0;
1263 		sk_setup_caps(sk, &rt->dst);
1264 	} else {
1265 		err = PTR_ERR(rt);
1266 
1267 		/* Routing failed... */
1268 		sk->sk_route_caps = 0;
1269 		/*
1270 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1271 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1272 		 */
1273 		if (!sock_net(sk)->ipv4.sysctl_ip_dynaddr ||
1274 		    sk->sk_state != TCP_SYN_SENT ||
1275 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1276 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1277 			sk->sk_err_soft = -err;
1278 	}
1279 
1280 	return err;
1281 }
1282 EXPORT_SYMBOL(inet_sk_rebuild_header);
1283 
1284 void inet_sk_set_state(struct sock *sk, int state)
1285 {
1286 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1287 	sk->sk_state = state;
1288 }
1289 EXPORT_SYMBOL(inet_sk_set_state);
1290 
1291 void inet_sk_state_store(struct sock *sk, int newstate)
1292 {
1293 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1294 	smp_store_release(&sk->sk_state, newstate);
1295 }
1296 
1297 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1298 				 netdev_features_t features)
1299 {
1300 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1301 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1302 	const struct net_offload *ops;
1303 	unsigned int offset = 0;
1304 	struct iphdr *iph;
1305 	int proto, tot_len;
1306 	int nhoff;
1307 	int ihl;
1308 	int id;
1309 
1310 	skb_reset_network_header(skb);
1311 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1312 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1313 		goto out;
1314 
1315 	iph = ip_hdr(skb);
1316 	ihl = iph->ihl * 4;
1317 	if (ihl < sizeof(*iph))
1318 		goto out;
1319 
1320 	id = ntohs(iph->id);
1321 	proto = iph->protocol;
1322 
1323 	/* Warning: after this point, iph might be no longer valid */
1324 	if (unlikely(!pskb_may_pull(skb, ihl)))
1325 		goto out;
1326 	__skb_pull(skb, ihl);
1327 
1328 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1329 	if (encap)
1330 		features &= skb->dev->hw_enc_features;
1331 	SKB_GSO_CB(skb)->encap_level += ihl;
1332 
1333 	skb_reset_transport_header(skb);
1334 
1335 	segs = ERR_PTR(-EPROTONOSUPPORT);
1336 
1337 	if (!skb->encapsulation || encap) {
1338 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1339 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1340 
1341 		/* fixed ID is invalid if DF bit is not set */
1342 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1343 			goto out;
1344 	}
1345 
1346 	ops = rcu_dereference(inet_offloads[proto]);
1347 	if (likely(ops && ops->callbacks.gso_segment))
1348 		segs = ops->callbacks.gso_segment(skb, features);
1349 
1350 	if (IS_ERR_OR_NULL(segs))
1351 		goto out;
1352 
1353 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1354 
1355 	skb = segs;
1356 	do {
1357 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1358 		if (udpfrag) {
1359 			iph->frag_off = htons(offset >> 3);
1360 			if (skb->next)
1361 				iph->frag_off |= htons(IP_MF);
1362 			offset += skb->len - nhoff - ihl;
1363 			tot_len = skb->len - nhoff;
1364 		} else if (skb_is_gso(skb)) {
1365 			if (!fixedid) {
1366 				iph->id = htons(id);
1367 				id += skb_shinfo(skb)->gso_segs;
1368 			}
1369 
1370 			if (gso_partial)
1371 				tot_len = skb_shinfo(skb)->gso_size +
1372 					  SKB_GSO_CB(skb)->data_offset +
1373 					  skb->head - (unsigned char *)iph;
1374 			else
1375 				tot_len = skb->len - nhoff;
1376 		} else {
1377 			if (!fixedid)
1378 				iph->id = htons(id++);
1379 			tot_len = skb->len - nhoff;
1380 		}
1381 		iph->tot_len = htons(tot_len);
1382 		ip_send_check(iph);
1383 		if (encap)
1384 			skb_reset_inner_headers(skb);
1385 		skb->network_header = (u8 *)iph - skb->head;
1386 		skb_reset_mac_len(skb);
1387 	} while ((skb = skb->next));
1388 
1389 out:
1390 	return segs;
1391 }
1392 EXPORT_SYMBOL(inet_gso_segment);
1393 
1394 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1395 					netdev_features_t features)
1396 {
1397 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1398 		return ERR_PTR(-EINVAL);
1399 
1400 	return inet_gso_segment(skb, features);
1401 }
1402 
1403 INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *,
1404 							   struct sk_buff *));
1405 INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
1406 							   struct sk_buff *));
1407 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1408 {
1409 	const struct net_offload *ops;
1410 	struct sk_buff *pp = NULL;
1411 	const struct iphdr *iph;
1412 	struct sk_buff *p;
1413 	unsigned int hlen;
1414 	unsigned int off;
1415 	unsigned int id;
1416 	int flush = 1;
1417 	int proto;
1418 
1419 	off = skb_gro_offset(skb);
1420 	hlen = off + sizeof(*iph);
1421 	iph = skb_gro_header_fast(skb, off);
1422 	if (skb_gro_header_hard(skb, hlen)) {
1423 		iph = skb_gro_header_slow(skb, hlen, off);
1424 		if (unlikely(!iph))
1425 			goto out;
1426 	}
1427 
1428 	proto = iph->protocol;
1429 
1430 	rcu_read_lock();
1431 	ops = rcu_dereference(inet_offloads[proto]);
1432 	if (!ops || !ops->callbacks.gro_receive)
1433 		goto out_unlock;
1434 
1435 	if (*(u8 *)iph != 0x45)
1436 		goto out_unlock;
1437 
1438 	if (ip_is_fragment(iph))
1439 		goto out_unlock;
1440 
1441 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1442 		goto out_unlock;
1443 
1444 	id = ntohl(*(__be32 *)&iph->id);
1445 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1446 	id >>= 16;
1447 
1448 	list_for_each_entry(p, head, list) {
1449 		struct iphdr *iph2;
1450 		u16 flush_id;
1451 
1452 		if (!NAPI_GRO_CB(p)->same_flow)
1453 			continue;
1454 
1455 		iph2 = (struct iphdr *)(p->data + off);
1456 		/* The above works because, with the exception of the top
1457 		 * (inner most) layer, we only aggregate pkts with the same
1458 		 * hdr length so all the hdrs we'll need to verify will start
1459 		 * at the same offset.
1460 		 */
1461 		if ((iph->protocol ^ iph2->protocol) |
1462 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1463 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1464 			NAPI_GRO_CB(p)->same_flow = 0;
1465 			continue;
1466 		}
1467 
1468 		/* All fields must match except length and checksum. */
1469 		NAPI_GRO_CB(p)->flush |=
1470 			(iph->ttl ^ iph2->ttl) |
1471 			(iph->tos ^ iph2->tos) |
1472 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1473 
1474 		NAPI_GRO_CB(p)->flush |= flush;
1475 
1476 		/* We need to store of the IP ID check to be included later
1477 		 * when we can verify that this packet does in fact belong
1478 		 * to a given flow.
1479 		 */
1480 		flush_id = (u16)(id - ntohs(iph2->id));
1481 
1482 		/* This bit of code makes it much easier for us to identify
1483 		 * the cases where we are doing atomic vs non-atomic IP ID
1484 		 * checks.  Specifically an atomic check can return IP ID
1485 		 * values 0 - 0xFFFF, while a non-atomic check can only
1486 		 * return 0 or 0xFFFF.
1487 		 */
1488 		if (!NAPI_GRO_CB(p)->is_atomic ||
1489 		    !(iph->frag_off & htons(IP_DF))) {
1490 			flush_id ^= NAPI_GRO_CB(p)->count;
1491 			flush_id = flush_id ? 0xFFFF : 0;
1492 		}
1493 
1494 		/* If the previous IP ID value was based on an atomic
1495 		 * datagram we can overwrite the value and ignore it.
1496 		 */
1497 		if (NAPI_GRO_CB(skb)->is_atomic)
1498 			NAPI_GRO_CB(p)->flush_id = flush_id;
1499 		else
1500 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1501 	}
1502 
1503 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1504 	NAPI_GRO_CB(skb)->flush |= flush;
1505 	skb_set_network_header(skb, off);
1506 	/* The above will be needed by the transport layer if there is one
1507 	 * immediately following this IP hdr.
1508 	 */
1509 
1510 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1511 	 * as we already checked checksum over ipv4 header was 0
1512 	 */
1513 	skb_gro_pull(skb, sizeof(*iph));
1514 	skb_set_transport_header(skb, skb_gro_offset(skb));
1515 
1516 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1517 				       ops->callbacks.gro_receive, head, skb);
1518 
1519 out_unlock:
1520 	rcu_read_unlock();
1521 
1522 out:
1523 	skb_gro_flush_final(skb, pp, flush);
1524 
1525 	return pp;
1526 }
1527 EXPORT_SYMBOL(inet_gro_receive);
1528 
1529 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1530 					struct sk_buff *skb)
1531 {
1532 	if (NAPI_GRO_CB(skb)->encap_mark) {
1533 		NAPI_GRO_CB(skb)->flush = 1;
1534 		return NULL;
1535 	}
1536 
1537 	NAPI_GRO_CB(skb)->encap_mark = 1;
1538 
1539 	return inet_gro_receive(head, skb);
1540 }
1541 
1542 #define SECONDS_PER_DAY	86400
1543 
1544 /* inet_current_timestamp - Return IP network timestamp
1545  *
1546  * Return milliseconds since midnight in network byte order.
1547  */
1548 __be32 inet_current_timestamp(void)
1549 {
1550 	u32 secs;
1551 	u32 msecs;
1552 	struct timespec64 ts;
1553 
1554 	ktime_get_real_ts64(&ts);
1555 
1556 	/* Get secs since midnight. */
1557 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1558 	/* Convert to msecs. */
1559 	msecs = secs * MSEC_PER_SEC;
1560 	/* Convert nsec to msec. */
1561 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1562 
1563 	/* Convert to network byte order. */
1564 	return htonl(msecs);
1565 }
1566 EXPORT_SYMBOL(inet_current_timestamp);
1567 
1568 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1569 {
1570 	if (sk->sk_family == AF_INET)
1571 		return ip_recv_error(sk, msg, len, addr_len);
1572 #if IS_ENABLED(CONFIG_IPV6)
1573 	if (sk->sk_family == AF_INET6)
1574 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1575 #endif
1576 	return -EINVAL;
1577 }
1578 
1579 INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *, int));
1580 INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
1581 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1582 {
1583 	__be16 newlen = htons(skb->len - nhoff);
1584 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1585 	const struct net_offload *ops;
1586 	int proto = iph->protocol;
1587 	int err = -ENOSYS;
1588 
1589 	if (skb->encapsulation) {
1590 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1591 		skb_set_inner_network_header(skb, nhoff);
1592 	}
1593 
1594 	csum_replace2(&iph->check, iph->tot_len, newlen);
1595 	iph->tot_len = newlen;
1596 
1597 	rcu_read_lock();
1598 	ops = rcu_dereference(inet_offloads[proto]);
1599 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1600 		goto out_unlock;
1601 
1602 	/* Only need to add sizeof(*iph) to get to the next hdr below
1603 	 * because any hdr with option will have been flushed in
1604 	 * inet_gro_receive().
1605 	 */
1606 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1607 			      tcp4_gro_complete, udp4_gro_complete,
1608 			      skb, nhoff + sizeof(*iph));
1609 
1610 out_unlock:
1611 	rcu_read_unlock();
1612 
1613 	return err;
1614 }
1615 EXPORT_SYMBOL(inet_gro_complete);
1616 
1617 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1618 {
1619 	skb->encapsulation = 1;
1620 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1621 	return inet_gro_complete(skb, nhoff);
1622 }
1623 
1624 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1625 			 unsigned short type, unsigned char protocol,
1626 			 struct net *net)
1627 {
1628 	struct socket *sock;
1629 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1630 
1631 	if (rc == 0) {
1632 		*sk = sock->sk;
1633 		(*sk)->sk_allocation = GFP_ATOMIC;
1634 		/*
1635 		 * Unhash it so that IP input processing does not even see it,
1636 		 * we do not wish this socket to see incoming packets.
1637 		 */
1638 		(*sk)->sk_prot->unhash(*sk);
1639 	}
1640 	return rc;
1641 }
1642 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1643 
1644 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1645 {
1646 	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1647 }
1648 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1649 
1650 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1651 {
1652 	unsigned long res = 0;
1653 	int i;
1654 
1655 	for_each_possible_cpu(i)
1656 		res += snmp_get_cpu_field(mib, i, offt);
1657 	return res;
1658 }
1659 EXPORT_SYMBOL_GPL(snmp_fold_field);
1660 
1661 #if BITS_PER_LONG==32
1662 
1663 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1664 			 size_t syncp_offset)
1665 {
1666 	void *bhptr;
1667 	struct u64_stats_sync *syncp;
1668 	u64 v;
1669 	unsigned int start;
1670 
1671 	bhptr = per_cpu_ptr(mib, cpu);
1672 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1673 	do {
1674 		start = u64_stats_fetch_begin_irq(syncp);
1675 		v = *(((u64 *)bhptr) + offt);
1676 	} while (u64_stats_fetch_retry_irq(syncp, start));
1677 
1678 	return v;
1679 }
1680 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1681 
1682 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1683 {
1684 	u64 res = 0;
1685 	int cpu;
1686 
1687 	for_each_possible_cpu(cpu) {
1688 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1689 	}
1690 	return res;
1691 }
1692 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1693 #endif
1694 
1695 #ifdef CONFIG_IP_MULTICAST
1696 static const struct net_protocol igmp_protocol = {
1697 	.handler =	igmp_rcv,
1698 	.netns_ok =	1,
1699 };
1700 #endif
1701 
1702 /* thinking of making this const? Don't.
1703  * early_demux can change based on sysctl.
1704  */
1705 static struct net_protocol tcp_protocol = {
1706 	.early_demux	=	tcp_v4_early_demux,
1707 	.early_demux_handler =  tcp_v4_early_demux,
1708 	.handler	=	tcp_v4_rcv,
1709 	.err_handler	=	tcp_v4_err,
1710 	.no_policy	=	1,
1711 	.netns_ok	=	1,
1712 	.icmp_strict_tag_validation = 1,
1713 };
1714 
1715 /* thinking of making this const? Don't.
1716  * early_demux can change based on sysctl.
1717  */
1718 static struct net_protocol udp_protocol = {
1719 	.early_demux =	udp_v4_early_demux,
1720 	.early_demux_handler =	udp_v4_early_demux,
1721 	.handler =	udp_rcv,
1722 	.err_handler =	udp_err,
1723 	.no_policy =	1,
1724 	.netns_ok =	1,
1725 };
1726 
1727 static const struct net_protocol icmp_protocol = {
1728 	.handler =	icmp_rcv,
1729 	.err_handler =	icmp_err,
1730 	.no_policy =	1,
1731 	.netns_ok =	1,
1732 };
1733 
1734 static __net_init int ipv4_mib_init_net(struct net *net)
1735 {
1736 	int i;
1737 
1738 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1739 	if (!net->mib.tcp_statistics)
1740 		goto err_tcp_mib;
1741 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1742 	if (!net->mib.ip_statistics)
1743 		goto err_ip_mib;
1744 
1745 	for_each_possible_cpu(i) {
1746 		struct ipstats_mib *af_inet_stats;
1747 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1748 		u64_stats_init(&af_inet_stats->syncp);
1749 	}
1750 
1751 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1752 	if (!net->mib.net_statistics)
1753 		goto err_net_mib;
1754 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1755 	if (!net->mib.udp_statistics)
1756 		goto err_udp_mib;
1757 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1758 	if (!net->mib.udplite_statistics)
1759 		goto err_udplite_mib;
1760 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1761 	if (!net->mib.icmp_statistics)
1762 		goto err_icmp_mib;
1763 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1764 					      GFP_KERNEL);
1765 	if (!net->mib.icmpmsg_statistics)
1766 		goto err_icmpmsg_mib;
1767 
1768 	tcp_mib_init(net);
1769 	return 0;
1770 
1771 err_icmpmsg_mib:
1772 	free_percpu(net->mib.icmp_statistics);
1773 err_icmp_mib:
1774 	free_percpu(net->mib.udplite_statistics);
1775 err_udplite_mib:
1776 	free_percpu(net->mib.udp_statistics);
1777 err_udp_mib:
1778 	free_percpu(net->mib.net_statistics);
1779 err_net_mib:
1780 	free_percpu(net->mib.ip_statistics);
1781 err_ip_mib:
1782 	free_percpu(net->mib.tcp_statistics);
1783 err_tcp_mib:
1784 	return -ENOMEM;
1785 }
1786 
1787 static __net_exit void ipv4_mib_exit_net(struct net *net)
1788 {
1789 	kfree(net->mib.icmpmsg_statistics);
1790 	free_percpu(net->mib.icmp_statistics);
1791 	free_percpu(net->mib.udplite_statistics);
1792 	free_percpu(net->mib.udp_statistics);
1793 	free_percpu(net->mib.net_statistics);
1794 	free_percpu(net->mib.ip_statistics);
1795 	free_percpu(net->mib.tcp_statistics);
1796 #ifdef CONFIG_MPTCP
1797 	/* allocated on demand, see mptcp_init_sock() */
1798 	free_percpu(net->mib.mptcp_statistics);
1799 #endif
1800 }
1801 
1802 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1803 	.init = ipv4_mib_init_net,
1804 	.exit = ipv4_mib_exit_net,
1805 };
1806 
1807 static int __init init_ipv4_mibs(void)
1808 {
1809 	return register_pernet_subsys(&ipv4_mib_ops);
1810 }
1811 
1812 static __net_init int inet_init_net(struct net *net)
1813 {
1814 	/*
1815 	 * Set defaults for local port range
1816 	 */
1817 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1818 	net->ipv4.ip_local_ports.range[0] =  32768;
1819 	net->ipv4.ip_local_ports.range[1] =  60999;
1820 
1821 	seqlock_init(&net->ipv4.ping_group_range.lock);
1822 	/*
1823 	 * Sane defaults - nobody may create ping sockets.
1824 	 * Boot scripts should set this to distro-specific group.
1825 	 */
1826 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1827 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1828 
1829 	/* Default values for sysctl-controlled parameters.
1830 	 * We set them here, in case sysctl is not compiled.
1831 	 */
1832 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1833 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1834 	net->ipv4.sysctl_ip_dynaddr = 0;
1835 	net->ipv4.sysctl_ip_early_demux = 1;
1836 	net->ipv4.sysctl_udp_early_demux = 1;
1837 	net->ipv4.sysctl_tcp_early_demux = 1;
1838 #ifdef CONFIG_SYSCTL
1839 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1840 #endif
1841 
1842 	/* Some igmp sysctl, whose values are always used */
1843 	net->ipv4.sysctl_igmp_max_memberships = 20;
1844 	net->ipv4.sysctl_igmp_max_msf = 10;
1845 	/* IGMP reports for link-local multicast groups are enabled by default */
1846 	net->ipv4.sysctl_igmp_llm_reports = 1;
1847 	net->ipv4.sysctl_igmp_qrv = 2;
1848 
1849 	return 0;
1850 }
1851 
1852 static __net_initdata struct pernet_operations af_inet_ops = {
1853 	.init = inet_init_net,
1854 };
1855 
1856 static int __init init_inet_pernet_ops(void)
1857 {
1858 	return register_pernet_subsys(&af_inet_ops);
1859 }
1860 
1861 static int ipv4_proc_init(void);
1862 
1863 /*
1864  *	IP protocol layer initialiser
1865  */
1866 
1867 static struct packet_offload ip_packet_offload __read_mostly = {
1868 	.type = cpu_to_be16(ETH_P_IP),
1869 	.callbacks = {
1870 		.gso_segment = inet_gso_segment,
1871 		.gro_receive = inet_gro_receive,
1872 		.gro_complete = inet_gro_complete,
1873 	},
1874 };
1875 
1876 static const struct net_offload ipip_offload = {
1877 	.callbacks = {
1878 		.gso_segment	= ipip_gso_segment,
1879 		.gro_receive	= ipip_gro_receive,
1880 		.gro_complete	= ipip_gro_complete,
1881 	},
1882 };
1883 
1884 static int __init ipip_offload_init(void)
1885 {
1886 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1887 }
1888 
1889 static int __init ipv4_offload_init(void)
1890 {
1891 	/*
1892 	 * Add offloads
1893 	 */
1894 	if (udpv4_offload_init() < 0)
1895 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1896 	if (tcpv4_offload_init() < 0)
1897 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1898 	if (ipip_offload_init() < 0)
1899 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1900 
1901 	dev_add_offload(&ip_packet_offload);
1902 	return 0;
1903 }
1904 
1905 fs_initcall(ipv4_offload_init);
1906 
1907 static struct packet_type ip_packet_type __read_mostly = {
1908 	.type = cpu_to_be16(ETH_P_IP),
1909 	.func = ip_rcv,
1910 	.list_func = ip_list_rcv,
1911 };
1912 
1913 static int __init inet_init(void)
1914 {
1915 	struct inet_protosw *q;
1916 	struct list_head *r;
1917 	int rc = -EINVAL;
1918 
1919 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1920 
1921 	rc = proto_register(&tcp_prot, 1);
1922 	if (rc)
1923 		goto out;
1924 
1925 	rc = proto_register(&udp_prot, 1);
1926 	if (rc)
1927 		goto out_unregister_tcp_proto;
1928 
1929 	rc = proto_register(&raw_prot, 1);
1930 	if (rc)
1931 		goto out_unregister_udp_proto;
1932 
1933 	rc = proto_register(&ping_prot, 1);
1934 	if (rc)
1935 		goto out_unregister_raw_proto;
1936 
1937 	/*
1938 	 *	Tell SOCKET that we are alive...
1939 	 */
1940 
1941 	(void)sock_register(&inet_family_ops);
1942 
1943 #ifdef CONFIG_SYSCTL
1944 	ip_static_sysctl_init();
1945 #endif
1946 
1947 	/*
1948 	 *	Add all the base protocols.
1949 	 */
1950 
1951 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1952 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1953 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1954 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1955 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1956 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1957 #ifdef CONFIG_IP_MULTICAST
1958 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1959 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1960 #endif
1961 
1962 	/* Register the socket-side information for inet_create. */
1963 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1964 		INIT_LIST_HEAD(r);
1965 
1966 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1967 		inet_register_protosw(q);
1968 
1969 	/*
1970 	 *	Set the ARP module up
1971 	 */
1972 
1973 	arp_init();
1974 
1975 	/*
1976 	 *	Set the IP module up
1977 	 */
1978 
1979 	ip_init();
1980 
1981 	/* Setup TCP slab cache for open requests. */
1982 	tcp_init();
1983 
1984 	/* Setup UDP memory threshold */
1985 	udp_init();
1986 
1987 	/* Add UDP-Lite (RFC 3828) */
1988 	udplite4_register();
1989 
1990 	raw_init();
1991 
1992 	ping_init();
1993 
1994 	/*
1995 	 *	Set the ICMP layer up
1996 	 */
1997 
1998 	if (icmp_init() < 0)
1999 		panic("Failed to create the ICMP control socket.\n");
2000 
2001 	/*
2002 	 *	Initialise the multicast router
2003 	 */
2004 #if defined(CONFIG_IP_MROUTE)
2005 	if (ip_mr_init())
2006 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2007 #endif
2008 
2009 	if (init_inet_pernet_ops())
2010 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2011 	/*
2012 	 *	Initialise per-cpu ipv4 mibs
2013 	 */
2014 
2015 	if (init_ipv4_mibs())
2016 		pr_crit("%s: Cannot init ipv4 mibs\n", __func__);
2017 
2018 	ipv4_proc_init();
2019 
2020 	ipfrag_init();
2021 
2022 	dev_add_pack(&ip_packet_type);
2023 
2024 	ip_tunnel_core_init();
2025 
2026 	rc = 0;
2027 out:
2028 	return rc;
2029 out_unregister_raw_proto:
2030 	proto_unregister(&raw_prot);
2031 out_unregister_udp_proto:
2032 	proto_unregister(&udp_prot);
2033 out_unregister_tcp_proto:
2034 	proto_unregister(&tcp_prot);
2035 	goto out;
2036 }
2037 
2038 fs_initcall(inet_init);
2039 
2040 /* ------------------------------------------------------------------------ */
2041 
2042 #ifdef CONFIG_PROC_FS
2043 static int __init ipv4_proc_init(void)
2044 {
2045 	int rc = 0;
2046 
2047 	if (raw_proc_init())
2048 		goto out_raw;
2049 	if (tcp4_proc_init())
2050 		goto out_tcp;
2051 	if (udp4_proc_init())
2052 		goto out_udp;
2053 	if (ping_proc_init())
2054 		goto out_ping;
2055 	if (ip_misc_proc_init())
2056 		goto out_misc;
2057 out:
2058 	return rc;
2059 out_misc:
2060 	ping_proc_exit();
2061 out_ping:
2062 	udp4_proc_exit();
2063 out_udp:
2064 	tcp4_proc_exit();
2065 out_tcp:
2066 	raw_proc_exit();
2067 out_raw:
2068 	rc = -ENOMEM;
2069 	goto out;
2070 }
2071 
2072 #else /* CONFIG_PROC_FS */
2073 static int __init ipv4_proc_init(void)
2074 {
2075 	return 0;
2076 }
2077 #endif /* CONFIG_PROC_FS */
2078