xref: /linux/net/ipv4/af_inet.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
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/gro.h>
103 #include <net/gso.h>
104 #include <net/tcp.h>
105 #include <net/udp.h>
106 #include <net/udplite.h>
107 #include <net/ping.h>
108 #include <linux/skbuff.h>
109 #include <net/sock.h>
110 #include <net/raw.h>
111 #include <net/icmp.h>
112 #include <net/inet_common.h>
113 #include <net/ip_tunnels.h>
114 #include <net/xfrm.h>
115 #include <net/net_namespace.h>
116 #include <net/secure_seq.h>
117 #ifdef CONFIG_IP_MROUTE
118 #include <linux/mroute.h>
119 #endif
120 #include <net/l3mdev.h>
121 #include <net/compat.h>
122 
123 #include <trace/events/sock.h>
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_final(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_ONCE(atomic_read(&sk->sk_rmem_alloc));
153 	WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc));
154 	WARN_ON_ONCE(sk->sk_wmem_queued);
155 	WARN_ON_ONCE(sk_forward_alloc_get(sk));
156 
157 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
158 	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
159 	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
160 }
161 EXPORT_SYMBOL(inet_sock_destruct);
162 
163 /*
164  *	The routines beyond this point handle the behaviour of an AF_INET
165  *	socket object. Mostly it punts to the subprotocols of IP to do
166  *	the work.
167  */
168 
169 /*
170  *	Automatically bind an unbound socket.
171  */
172 
173 static int inet_autobind(struct sock *sk)
174 {
175 	struct inet_sock *inet;
176 	/* We may need to bind the socket. */
177 	lock_sock(sk);
178 	inet = inet_sk(sk);
179 	if (!inet->inet_num) {
180 		if (sk->sk_prot->get_port(sk, 0)) {
181 			release_sock(sk);
182 			return -EAGAIN;
183 		}
184 		inet->inet_sport = htons(inet->inet_num);
185 	}
186 	release_sock(sk);
187 	return 0;
188 }
189 
190 int __inet_listen_sk(struct sock *sk, int backlog)
191 {
192 	unsigned char old_state = sk->sk_state;
193 	int err, tcp_fastopen;
194 
195 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
196 		return -EINVAL;
197 
198 	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
199 	/* Really, if the socket is already in listen state
200 	 * we can only allow the backlog to be adjusted.
201 	 */
202 	if (old_state != TCP_LISTEN) {
203 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
204 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
205 		 * Also fastopen backlog may already been set via the option
206 		 * because the socket was in TCP_LISTEN state previously but
207 		 * was shutdown() rather than close().
208 		 */
209 		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
210 		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
211 		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
212 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
213 			fastopen_queue_tune(sk, backlog);
214 			tcp_fastopen_init_key_once(sock_net(sk));
215 		}
216 
217 		err = inet_csk_listen_start(sk);
218 		if (err)
219 			return err;
220 
221 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
222 	}
223 	return 0;
224 }
225 
226 /*
227  *	Move a socket into listening state.
228  */
229 int inet_listen(struct socket *sock, int backlog)
230 {
231 	struct sock *sk = sock->sk;
232 	int err = -EINVAL;
233 
234 	lock_sock(sk);
235 
236 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
237 		goto out;
238 
239 	err = __inet_listen_sk(sk, backlog);
240 
241 out:
242 	release_sock(sk);
243 	return err;
244 }
245 EXPORT_SYMBOL(inet_listen);
246 
247 /*
248  *	Create an inet socket.
249  */
250 
251 static int inet_create(struct net *net, struct socket *sock, int protocol,
252 		       int kern)
253 {
254 	struct sock *sk;
255 	struct inet_protosw *answer;
256 	struct inet_sock *inet;
257 	struct proto *answer_prot;
258 	unsigned char answer_flags;
259 	int try_loading_module = 0;
260 	int err;
261 
262 	if (protocol < 0 || protocol >= IPPROTO_MAX)
263 		return -EINVAL;
264 
265 	sock->state = SS_UNCONNECTED;
266 
267 	/* Look for the requested type/protocol pair. */
268 lookup_protocol:
269 	err = -ESOCKTNOSUPPORT;
270 	rcu_read_lock();
271 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
272 
273 		err = 0;
274 		/* Check the non-wild match. */
275 		if (protocol == answer->protocol) {
276 			if (protocol != IPPROTO_IP)
277 				break;
278 		} else {
279 			/* Check for the two wild cases. */
280 			if (IPPROTO_IP == protocol) {
281 				protocol = answer->protocol;
282 				break;
283 			}
284 			if (IPPROTO_IP == answer->protocol)
285 				break;
286 		}
287 		err = -EPROTONOSUPPORT;
288 	}
289 
290 	if (unlikely(err)) {
291 		if (try_loading_module < 2) {
292 			rcu_read_unlock();
293 			/*
294 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
295 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
296 			 */
297 			if (++try_loading_module == 1)
298 				request_module("net-pf-%d-proto-%d-type-%d",
299 					       PF_INET, protocol, sock->type);
300 			/*
301 			 * Fall back to generic, e.g. net-pf-2-proto-132
302 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
303 			 */
304 			else
305 				request_module("net-pf-%d-proto-%d",
306 					       PF_INET, protocol);
307 			goto lookup_protocol;
308 		} else
309 			goto out_rcu_unlock;
310 	}
311 
312 	err = -EPERM;
313 	if (sock->type == SOCK_RAW && !kern &&
314 	    !ns_capable(net->user_ns, CAP_NET_RAW))
315 		goto out_rcu_unlock;
316 
317 	sock->ops = answer->ops;
318 	answer_prot = answer->prot;
319 	answer_flags = answer->flags;
320 	rcu_read_unlock();
321 
322 	WARN_ON(!answer_prot->slab);
323 
324 	err = -ENOMEM;
325 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
326 	if (!sk)
327 		goto out;
328 
329 	err = 0;
330 	if (INET_PROTOSW_REUSE & answer_flags)
331 		sk->sk_reuse = SK_CAN_REUSE;
332 
333 	if (INET_PROTOSW_ICSK & answer_flags)
334 		inet_init_csk_locks(sk);
335 
336 	inet = inet_sk(sk);
337 	inet_assign_bit(IS_ICSK, sk, INET_PROTOSW_ICSK & answer_flags);
338 
339 	inet_clear_bit(NODEFRAG, sk);
340 
341 	if (SOCK_RAW == sock->type) {
342 		inet->inet_num = protocol;
343 		if (IPPROTO_RAW == protocol)
344 			inet_set_bit(HDRINCL, sk);
345 	}
346 
347 	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
348 		inet->pmtudisc = IP_PMTUDISC_DONT;
349 	else
350 		inet->pmtudisc = IP_PMTUDISC_WANT;
351 
352 	atomic_set(&inet->inet_id, 0);
353 
354 	sock_init_data(sock, sk);
355 
356 	sk->sk_destruct	   = inet_sock_destruct;
357 	sk->sk_protocol	   = protocol;
358 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
359 	sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
360 
361 	inet->uc_ttl	= -1;
362 	inet_set_bit(MC_LOOP, sk);
363 	inet->mc_ttl	= 1;
364 	inet_set_bit(MC_ALL, sk);
365 	inet->mc_index	= 0;
366 	inet->mc_list	= NULL;
367 	inet->rcv_tos	= 0;
368 
369 	if (inet->inet_num) {
370 		/* It assumes that any protocol which allows
371 		 * the user to assign a number at socket
372 		 * creation time automatically
373 		 * shares.
374 		 */
375 		inet->inet_sport = htons(inet->inet_num);
376 		/* Add to protocol hash chains. */
377 		err = sk->sk_prot->hash(sk);
378 		if (err) {
379 			sk_common_release(sk);
380 			goto out;
381 		}
382 	}
383 
384 	if (sk->sk_prot->init) {
385 		err = sk->sk_prot->init(sk);
386 		if (err) {
387 			sk_common_release(sk);
388 			goto out;
389 		}
390 	}
391 
392 	if (!kern) {
393 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
394 		if (err) {
395 			sk_common_release(sk);
396 			goto out;
397 		}
398 	}
399 out:
400 	return err;
401 out_rcu_unlock:
402 	rcu_read_unlock();
403 	goto out;
404 }
405 
406 
407 /*
408  *	The peer socket should always be NULL (or else). When we call this
409  *	function we are destroying the object and from then on nobody
410  *	should refer to it.
411  */
412 int inet_release(struct socket *sock)
413 {
414 	struct sock *sk = sock->sk;
415 
416 	if (sk) {
417 		long timeout;
418 
419 		if (!sk->sk_kern_sock)
420 			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
421 
422 		/* Applications forget to leave groups before exiting */
423 		ip_mc_drop_socket(sk);
424 
425 		/* If linger is set, we don't return until the close
426 		 * is complete.  Otherwise we return immediately. The
427 		 * actually closing is done the same either way.
428 		 *
429 		 * If the close is due to the process exiting, we never
430 		 * linger..
431 		 */
432 		timeout = 0;
433 		if (sock_flag(sk, SOCK_LINGER) &&
434 		    !(current->flags & PF_EXITING))
435 			timeout = sk->sk_lingertime;
436 		sk->sk_prot->close(sk, timeout);
437 		sock->sk = NULL;
438 	}
439 	return 0;
440 }
441 EXPORT_SYMBOL(inet_release);
442 
443 int inet_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len)
444 {
445 	u32 flags = BIND_WITH_LOCK;
446 	int err;
447 
448 	/* If the socket has its own bind function then use it. (RAW) */
449 	if (sk->sk_prot->bind) {
450 		return sk->sk_prot->bind(sk, uaddr, addr_len);
451 	}
452 	if (addr_len < sizeof(struct sockaddr_in))
453 		return -EINVAL;
454 
455 	/* BPF prog is run before any checks are done so that if the prog
456 	 * changes context in a wrong way it will be caught.
457 	 */
458 	err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, &addr_len,
459 						 CGROUP_INET4_BIND, &flags);
460 	if (err)
461 		return err;
462 
463 	return __inet_bind(sk, uaddr, addr_len, flags);
464 }
465 
466 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
467 {
468 	return inet_bind_sk(sock->sk, uaddr, addr_len);
469 }
470 EXPORT_SYMBOL(inet_bind);
471 
472 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
473 		u32 flags)
474 {
475 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
476 	struct inet_sock *inet = inet_sk(sk);
477 	struct net *net = sock_net(sk);
478 	unsigned short snum;
479 	int chk_addr_ret;
480 	u32 tb_id = RT_TABLE_LOCAL;
481 	int err;
482 
483 	if (addr->sin_family != AF_INET) {
484 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
485 		 * only if s_addr is INADDR_ANY.
486 		 */
487 		err = -EAFNOSUPPORT;
488 		if (addr->sin_family != AF_UNSPEC ||
489 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
490 			goto out;
491 	}
492 
493 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
494 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
495 
496 	/* Not specified by any standard per-se, however it breaks too
497 	 * many applications when removed.  It is unfortunate since
498 	 * allowing applications to make a non-local bind solves
499 	 * several problems with systems using dynamic addressing.
500 	 * (ie. your servers still start up even if your ISDN link
501 	 *  is temporarily down)
502 	 */
503 	err = -EADDRNOTAVAIL;
504 	if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,
505 	                                 chk_addr_ret))
506 		goto out;
507 
508 	snum = ntohs(addr->sin_port);
509 	err = -EACCES;
510 	if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
511 	    snum && inet_port_requires_bind_service(net, snum) &&
512 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
513 		goto out;
514 
515 	/*      We keep a pair of addresses. rcv_saddr is the one
516 	 *      used by hash lookups, and saddr is used for transmit.
517 	 *
518 	 *      In the BSD API these are the same except where it
519 	 *      would be illegal to use them (multicast/broadcast) in
520 	 *      which case the sending device address is used.
521 	 */
522 	if (flags & BIND_WITH_LOCK)
523 		lock_sock(sk);
524 
525 	/* Check these errors (active socket, double bind). */
526 	err = -EINVAL;
527 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
528 		goto out_release_sock;
529 
530 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
531 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
532 		inet->inet_saddr = 0;  /* Use device */
533 
534 	/* Make sure we are allowed to bind here. */
535 	if (snum || !(inet_test_bit(BIND_ADDRESS_NO_PORT, sk) ||
536 		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
537 		err = sk->sk_prot->get_port(sk, snum);
538 		if (err) {
539 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
540 			goto out_release_sock;
541 		}
542 		if (!(flags & BIND_FROM_BPF)) {
543 			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
544 			if (err) {
545 				inet->inet_saddr = inet->inet_rcv_saddr = 0;
546 				if (sk->sk_prot->put_port)
547 					sk->sk_prot->put_port(sk);
548 				goto out_release_sock;
549 			}
550 		}
551 	}
552 
553 	if (inet->inet_rcv_saddr)
554 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
555 	if (snum)
556 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
557 	inet->inet_sport = htons(inet->inet_num);
558 	inet->inet_daddr = 0;
559 	inet->inet_dport = 0;
560 	sk_dst_reset(sk);
561 	err = 0;
562 out_release_sock:
563 	if (flags & BIND_WITH_LOCK)
564 		release_sock(sk);
565 out:
566 	return err;
567 }
568 
569 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
570 		       int addr_len, int flags)
571 {
572 	struct sock *sk = sock->sk;
573 	const struct proto *prot;
574 	int err;
575 
576 	if (addr_len < sizeof(uaddr->sa_family))
577 		return -EINVAL;
578 
579 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
580 	prot = READ_ONCE(sk->sk_prot);
581 
582 	if (uaddr->sa_family == AF_UNSPEC)
583 		return prot->disconnect(sk, flags);
584 
585 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
586 		err = prot->pre_connect(sk, uaddr, addr_len);
587 		if (err)
588 			return err;
589 	}
590 
591 	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
592 		return -EAGAIN;
593 	return prot->connect(sk, uaddr, addr_len);
594 }
595 EXPORT_SYMBOL(inet_dgram_connect);
596 
597 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
598 {
599 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
600 
601 	add_wait_queue(sk_sleep(sk), &wait);
602 	sk->sk_write_pending += writebias;
603 
604 	/* Basic assumption: if someone sets sk->sk_err, he _must_
605 	 * change state of the socket from TCP_SYN_*.
606 	 * Connect() does not allow to get error notifications
607 	 * without closing the socket.
608 	 */
609 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
610 		release_sock(sk);
611 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
612 		lock_sock(sk);
613 		if (signal_pending(current) || !timeo)
614 			break;
615 	}
616 	remove_wait_queue(sk_sleep(sk), &wait);
617 	sk->sk_write_pending -= writebias;
618 	return timeo;
619 }
620 
621 /*
622  *	Connect to a remote host. There is regrettably still a little
623  *	TCP 'magic' in here.
624  */
625 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
626 			  int addr_len, int flags, int is_sendmsg)
627 {
628 	struct sock *sk = sock->sk;
629 	int err;
630 	long timeo;
631 
632 	/*
633 	 * uaddr can be NULL and addr_len can be 0 if:
634 	 * sk is a TCP fastopen active socket and
635 	 * TCP_FASTOPEN_CONNECT sockopt is set and
636 	 * we already have a valid cookie for this socket.
637 	 * In this case, user can call write() after connect().
638 	 * write() will invoke tcp_sendmsg_fastopen() which calls
639 	 * __inet_stream_connect().
640 	 */
641 	if (uaddr) {
642 		if (addr_len < sizeof(uaddr->sa_family))
643 			return -EINVAL;
644 
645 		if (uaddr->sa_family == AF_UNSPEC) {
646 			sk->sk_disconnects++;
647 			err = sk->sk_prot->disconnect(sk, flags);
648 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
649 			goto out;
650 		}
651 	}
652 
653 	switch (sock->state) {
654 	default:
655 		err = -EINVAL;
656 		goto out;
657 	case SS_CONNECTED:
658 		err = -EISCONN;
659 		goto out;
660 	case SS_CONNECTING:
661 		if (inet_test_bit(DEFER_CONNECT, sk))
662 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
663 		else
664 			err = -EALREADY;
665 		/* Fall out of switch with err, set for this state */
666 		break;
667 	case SS_UNCONNECTED:
668 		err = -EISCONN;
669 		if (sk->sk_state != TCP_CLOSE)
670 			goto out;
671 
672 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
673 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
674 			if (err)
675 				goto out;
676 		}
677 
678 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
679 		if (err < 0)
680 			goto out;
681 
682 		sock->state = SS_CONNECTING;
683 
684 		if (!err && inet_test_bit(DEFER_CONNECT, sk))
685 			goto out;
686 
687 		/* Just entered SS_CONNECTING state; the only
688 		 * difference is that return value in non-blocking
689 		 * case is EINPROGRESS, rather than EALREADY.
690 		 */
691 		err = -EINPROGRESS;
692 		break;
693 	}
694 
695 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
696 
697 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
698 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
699 				tcp_sk(sk)->fastopen_req &&
700 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
701 		int dis = sk->sk_disconnects;
702 
703 		/* Error code is set above */
704 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
705 			goto out;
706 
707 		err = sock_intr_errno(timeo);
708 		if (signal_pending(current))
709 			goto out;
710 
711 		if (dis != sk->sk_disconnects) {
712 			err = -EPIPE;
713 			goto out;
714 		}
715 	}
716 
717 	/* Connection was closed by RST, timeout, ICMP error
718 	 * or another process disconnected us.
719 	 */
720 	if (sk->sk_state == TCP_CLOSE)
721 		goto sock_error;
722 
723 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
724 	 * and error was received after socket entered established state.
725 	 * Hence, it is handled normally after connect() return successfully.
726 	 */
727 
728 	sock->state = SS_CONNECTED;
729 	err = 0;
730 out:
731 	return err;
732 
733 sock_error:
734 	err = sock_error(sk) ? : -ECONNABORTED;
735 	sock->state = SS_UNCONNECTED;
736 	sk->sk_disconnects++;
737 	if (sk->sk_prot->disconnect(sk, flags))
738 		sock->state = SS_DISCONNECTING;
739 	goto out;
740 }
741 EXPORT_SYMBOL(__inet_stream_connect);
742 
743 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
744 			int addr_len, int flags)
745 {
746 	int err;
747 
748 	lock_sock(sock->sk);
749 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
750 	release_sock(sock->sk);
751 	return err;
752 }
753 EXPORT_SYMBOL(inet_stream_connect);
754 
755 void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
756 {
757 	sock_rps_record_flow(newsk);
758 	WARN_ON(!((1 << newsk->sk_state) &
759 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
760 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
761 
762 	if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
763 		set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
764 	sock_graft(newsk, newsock);
765 
766 	newsock->state = SS_CONNECTED;
767 }
768 
769 /*
770  *	Accept a pending connection. The TCP layer now gives BSD semantics.
771  */
772 
773 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
774 		bool kern)
775 {
776 	struct sock *sk1 = sock->sk, *sk2;
777 	int err = -EINVAL;
778 
779 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
780 	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
781 	if (!sk2)
782 		return err;
783 
784 	lock_sock(sk2);
785 	__inet_accept(sock, newsock, sk2);
786 	release_sock(sk2);
787 	return 0;
788 }
789 EXPORT_SYMBOL(inet_accept);
790 
791 /*
792  *	This does both peername and sockname.
793  */
794 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
795 		 int peer)
796 {
797 	struct sock *sk		= sock->sk;
798 	struct inet_sock *inet	= inet_sk(sk);
799 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
800 	int sin_addr_len = sizeof(*sin);
801 
802 	sin->sin_family = AF_INET;
803 	lock_sock(sk);
804 	if (peer) {
805 		if (!inet->inet_dport ||
806 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
807 		     peer == 1)) {
808 			release_sock(sk);
809 			return -ENOTCONN;
810 		}
811 		sin->sin_port = inet->inet_dport;
812 		sin->sin_addr.s_addr = inet->inet_daddr;
813 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
814 				       CGROUP_INET4_GETPEERNAME);
815 	} else {
816 		__be32 addr = inet->inet_rcv_saddr;
817 		if (!addr)
818 			addr = inet->inet_saddr;
819 		sin->sin_port = inet->inet_sport;
820 		sin->sin_addr.s_addr = addr;
821 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
822 				       CGROUP_INET4_GETSOCKNAME);
823 	}
824 	release_sock(sk);
825 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
826 	return sin_addr_len;
827 }
828 EXPORT_SYMBOL(inet_getname);
829 
830 int inet_send_prepare(struct sock *sk)
831 {
832 	sock_rps_record_flow(sk);
833 
834 	/* We may need to bind the socket. */
835 	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
836 	    inet_autobind(sk))
837 		return -EAGAIN;
838 
839 	return 0;
840 }
841 EXPORT_SYMBOL_GPL(inet_send_prepare);
842 
843 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
844 {
845 	struct sock *sk = sock->sk;
846 
847 	if (unlikely(inet_send_prepare(sk)))
848 		return -EAGAIN;
849 
850 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
851 			       sk, msg, size);
852 }
853 EXPORT_SYMBOL(inet_sendmsg);
854 
855 void inet_splice_eof(struct socket *sock)
856 {
857 	const struct proto *prot;
858 	struct sock *sk = sock->sk;
859 
860 	if (unlikely(inet_send_prepare(sk)))
861 		return;
862 
863 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
864 	prot = READ_ONCE(sk->sk_prot);
865 	if (prot->splice_eof)
866 		prot->splice_eof(sock);
867 }
868 EXPORT_SYMBOL_GPL(inet_splice_eof);
869 
870 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
871 					  size_t, int, int *));
872 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
873 		 int flags)
874 {
875 	struct sock *sk = sock->sk;
876 	int addr_len = 0;
877 	int err;
878 
879 	if (likely(!(flags & MSG_ERRQUEUE)))
880 		sock_rps_record_flow(sk);
881 
882 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
883 			      sk, msg, size, flags, &addr_len);
884 	if (err >= 0)
885 		msg->msg_namelen = addr_len;
886 	return err;
887 }
888 EXPORT_SYMBOL(inet_recvmsg);
889 
890 int inet_shutdown(struct socket *sock, int how)
891 {
892 	struct sock *sk = sock->sk;
893 	int err = 0;
894 
895 	/* This should really check to make sure
896 	 * the socket is a TCP socket. (WHY AC...)
897 	 */
898 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
899 		       1->2 bit 2 snds.
900 		       2->3 */
901 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
902 		return -EINVAL;
903 
904 	lock_sock(sk);
905 	if (sock->state == SS_CONNECTING) {
906 		if ((1 << sk->sk_state) &
907 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
908 			sock->state = SS_DISCONNECTING;
909 		else
910 			sock->state = SS_CONNECTED;
911 	}
912 
913 	switch (sk->sk_state) {
914 	case TCP_CLOSE:
915 		err = -ENOTCONN;
916 		/* Hack to wake up other listeners, who can poll for
917 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
918 		fallthrough;
919 	default:
920 		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
921 		if (sk->sk_prot->shutdown)
922 			sk->sk_prot->shutdown(sk, how);
923 		break;
924 
925 	/* Remaining two branches are temporary solution for missing
926 	 * close() in multithreaded environment. It is _not_ a good idea,
927 	 * but we have no choice until close() is repaired at VFS level.
928 	 */
929 	case TCP_LISTEN:
930 		if (!(how & RCV_SHUTDOWN))
931 			break;
932 		fallthrough;
933 	case TCP_SYN_SENT:
934 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
935 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
936 		break;
937 	}
938 
939 	/* Wake up anyone sleeping in poll. */
940 	sk->sk_state_change(sk);
941 	release_sock(sk);
942 	return err;
943 }
944 EXPORT_SYMBOL(inet_shutdown);
945 
946 /*
947  *	ioctl() calls you can issue on an INET socket. Most of these are
948  *	device configuration and stuff and very rarely used. Some ioctls
949  *	pass on to the socket itself.
950  *
951  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
952  *	loads the devconfigure module does its configuring and unloads it.
953  *	There's a good 20K of config code hanging around the kernel.
954  */
955 
956 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
957 {
958 	struct sock *sk = sock->sk;
959 	int err = 0;
960 	struct net *net = sock_net(sk);
961 	void __user *p = (void __user *)arg;
962 	struct ifreq ifr;
963 	struct rtentry rt;
964 
965 	switch (cmd) {
966 	case SIOCADDRT:
967 	case SIOCDELRT:
968 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
969 			return -EFAULT;
970 		err = ip_rt_ioctl(net, cmd, &rt);
971 		break;
972 	case SIOCRTMSG:
973 		err = -EINVAL;
974 		break;
975 	case SIOCDARP:
976 	case SIOCGARP:
977 	case SIOCSARP:
978 		err = arp_ioctl(net, cmd, (void __user *)arg);
979 		break;
980 	case SIOCGIFADDR:
981 	case SIOCGIFBRDADDR:
982 	case SIOCGIFNETMASK:
983 	case SIOCGIFDSTADDR:
984 	case SIOCGIFPFLAGS:
985 		if (get_user_ifreq(&ifr, NULL, p))
986 			return -EFAULT;
987 		err = devinet_ioctl(net, cmd, &ifr);
988 		if (!err && put_user_ifreq(&ifr, p))
989 			err = -EFAULT;
990 		break;
991 
992 	case SIOCSIFADDR:
993 	case SIOCSIFBRDADDR:
994 	case SIOCSIFNETMASK:
995 	case SIOCSIFDSTADDR:
996 	case SIOCSIFPFLAGS:
997 	case SIOCSIFFLAGS:
998 		if (get_user_ifreq(&ifr, NULL, p))
999 			return -EFAULT;
1000 		err = devinet_ioctl(net, cmd, &ifr);
1001 		break;
1002 	default:
1003 		if (sk->sk_prot->ioctl)
1004 			err = sk_ioctl(sk, cmd, (void __user *)arg);
1005 		else
1006 			err = -ENOIOCTLCMD;
1007 		break;
1008 	}
1009 	return err;
1010 }
1011 EXPORT_SYMBOL(inet_ioctl);
1012 
1013 #ifdef CONFIG_COMPAT
1014 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1015 		struct compat_rtentry __user *ur)
1016 {
1017 	compat_uptr_t rtdev;
1018 	struct rtentry rt;
1019 
1020 	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1021 			3 * sizeof(struct sockaddr)) ||
1022 	    get_user(rt.rt_flags, &ur->rt_flags) ||
1023 	    get_user(rt.rt_metric, &ur->rt_metric) ||
1024 	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1025 	    get_user(rt.rt_window, &ur->rt_window) ||
1026 	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1027 	    get_user(rtdev, &ur->rt_dev))
1028 		return -EFAULT;
1029 
1030 	rt.rt_dev = compat_ptr(rtdev);
1031 	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1032 }
1033 
1034 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1035 {
1036 	void __user *argp = compat_ptr(arg);
1037 	struct sock *sk = sock->sk;
1038 
1039 	switch (cmd) {
1040 	case SIOCADDRT:
1041 	case SIOCDELRT:
1042 		return inet_compat_routing_ioctl(sk, cmd, argp);
1043 	default:
1044 		if (!sk->sk_prot->compat_ioctl)
1045 			return -ENOIOCTLCMD;
1046 		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1047 	}
1048 }
1049 #endif /* CONFIG_COMPAT */
1050 
1051 const struct proto_ops inet_stream_ops = {
1052 	.family		   = PF_INET,
1053 	.owner		   = THIS_MODULE,
1054 	.release	   = inet_release,
1055 	.bind		   = inet_bind,
1056 	.connect	   = inet_stream_connect,
1057 	.socketpair	   = sock_no_socketpair,
1058 	.accept		   = inet_accept,
1059 	.getname	   = inet_getname,
1060 	.poll		   = tcp_poll,
1061 	.ioctl		   = inet_ioctl,
1062 	.gettstamp	   = sock_gettstamp,
1063 	.listen		   = inet_listen,
1064 	.shutdown	   = inet_shutdown,
1065 	.setsockopt	   = sock_common_setsockopt,
1066 	.getsockopt	   = sock_common_getsockopt,
1067 	.sendmsg	   = inet_sendmsg,
1068 	.recvmsg	   = inet_recvmsg,
1069 #ifdef CONFIG_MMU
1070 	.mmap		   = tcp_mmap,
1071 #endif
1072 	.splice_eof	   = inet_splice_eof,
1073 	.splice_read	   = tcp_splice_read,
1074 	.read_sock	   = tcp_read_sock,
1075 	.read_skb	   = tcp_read_skb,
1076 	.sendmsg_locked    = tcp_sendmsg_locked,
1077 	.peek_len	   = tcp_peek_len,
1078 #ifdef CONFIG_COMPAT
1079 	.compat_ioctl	   = inet_compat_ioctl,
1080 #endif
1081 	.set_rcvlowat	   = tcp_set_rcvlowat,
1082 };
1083 EXPORT_SYMBOL(inet_stream_ops);
1084 
1085 const struct proto_ops inet_dgram_ops = {
1086 	.family		   = PF_INET,
1087 	.owner		   = THIS_MODULE,
1088 	.release	   = inet_release,
1089 	.bind		   = inet_bind,
1090 	.connect	   = inet_dgram_connect,
1091 	.socketpair	   = sock_no_socketpair,
1092 	.accept		   = sock_no_accept,
1093 	.getname	   = inet_getname,
1094 	.poll		   = udp_poll,
1095 	.ioctl		   = inet_ioctl,
1096 	.gettstamp	   = sock_gettstamp,
1097 	.listen		   = sock_no_listen,
1098 	.shutdown	   = inet_shutdown,
1099 	.setsockopt	   = sock_common_setsockopt,
1100 	.getsockopt	   = sock_common_getsockopt,
1101 	.sendmsg	   = inet_sendmsg,
1102 	.read_skb	   = udp_read_skb,
1103 	.recvmsg	   = inet_recvmsg,
1104 	.mmap		   = sock_no_mmap,
1105 	.splice_eof	   = inet_splice_eof,
1106 	.set_peek_off	   = sk_set_peek_off,
1107 #ifdef CONFIG_COMPAT
1108 	.compat_ioctl	   = inet_compat_ioctl,
1109 #endif
1110 };
1111 EXPORT_SYMBOL(inet_dgram_ops);
1112 
1113 /*
1114  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1115  * udp_poll
1116  */
1117 static const struct proto_ops inet_sockraw_ops = {
1118 	.family		   = PF_INET,
1119 	.owner		   = THIS_MODULE,
1120 	.release	   = inet_release,
1121 	.bind		   = inet_bind,
1122 	.connect	   = inet_dgram_connect,
1123 	.socketpair	   = sock_no_socketpair,
1124 	.accept		   = sock_no_accept,
1125 	.getname	   = inet_getname,
1126 	.poll		   = datagram_poll,
1127 	.ioctl		   = inet_ioctl,
1128 	.gettstamp	   = sock_gettstamp,
1129 	.listen		   = sock_no_listen,
1130 	.shutdown	   = inet_shutdown,
1131 	.setsockopt	   = sock_common_setsockopt,
1132 	.getsockopt	   = sock_common_getsockopt,
1133 	.sendmsg	   = inet_sendmsg,
1134 	.recvmsg	   = inet_recvmsg,
1135 	.mmap		   = sock_no_mmap,
1136 	.splice_eof	   = inet_splice_eof,
1137 #ifdef CONFIG_COMPAT
1138 	.compat_ioctl	   = inet_compat_ioctl,
1139 #endif
1140 };
1141 
1142 static const struct net_proto_family inet_family_ops = {
1143 	.family = PF_INET,
1144 	.create = inet_create,
1145 	.owner	= THIS_MODULE,
1146 };
1147 
1148 /* Upon startup we insert all the elements in inetsw_array[] into
1149  * the linked list inetsw.
1150  */
1151 static struct inet_protosw inetsw_array[] =
1152 {
1153 	{
1154 		.type =       SOCK_STREAM,
1155 		.protocol =   IPPROTO_TCP,
1156 		.prot =       &tcp_prot,
1157 		.ops =        &inet_stream_ops,
1158 		.flags =      INET_PROTOSW_PERMANENT |
1159 			      INET_PROTOSW_ICSK,
1160 	},
1161 
1162 	{
1163 		.type =       SOCK_DGRAM,
1164 		.protocol =   IPPROTO_UDP,
1165 		.prot =       &udp_prot,
1166 		.ops =        &inet_dgram_ops,
1167 		.flags =      INET_PROTOSW_PERMANENT,
1168        },
1169 
1170        {
1171 		.type =       SOCK_DGRAM,
1172 		.protocol =   IPPROTO_ICMP,
1173 		.prot =       &ping_prot,
1174 		.ops =        &inet_sockraw_ops,
1175 		.flags =      INET_PROTOSW_REUSE,
1176        },
1177 
1178        {
1179 	       .type =       SOCK_RAW,
1180 	       .protocol =   IPPROTO_IP,	/* wild card */
1181 	       .prot =       &raw_prot,
1182 	       .ops =        &inet_sockraw_ops,
1183 	       .flags =      INET_PROTOSW_REUSE,
1184        }
1185 };
1186 
1187 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1188 
1189 void inet_register_protosw(struct inet_protosw *p)
1190 {
1191 	struct list_head *lh;
1192 	struct inet_protosw *answer;
1193 	int protocol = p->protocol;
1194 	struct list_head *last_perm;
1195 
1196 	spin_lock_bh(&inetsw_lock);
1197 
1198 	if (p->type >= SOCK_MAX)
1199 		goto out_illegal;
1200 
1201 	/* If we are trying to override a permanent protocol, bail. */
1202 	last_perm = &inetsw[p->type];
1203 	list_for_each(lh, &inetsw[p->type]) {
1204 		answer = list_entry(lh, struct inet_protosw, list);
1205 		/* Check only the non-wild match. */
1206 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1207 			break;
1208 		if (protocol == answer->protocol)
1209 			goto out_permanent;
1210 		last_perm = lh;
1211 	}
1212 
1213 	/* Add the new entry after the last permanent entry if any, so that
1214 	 * the new entry does not override a permanent entry when matched with
1215 	 * a wild-card protocol. But it is allowed to override any existing
1216 	 * non-permanent entry.  This means that when we remove this entry, the
1217 	 * system automatically returns to the old behavior.
1218 	 */
1219 	list_add_rcu(&p->list, last_perm);
1220 out:
1221 	spin_unlock_bh(&inetsw_lock);
1222 
1223 	return;
1224 
1225 out_permanent:
1226 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1227 	goto out;
1228 
1229 out_illegal:
1230 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1231 	       p->type);
1232 	goto out;
1233 }
1234 EXPORT_SYMBOL(inet_register_protosw);
1235 
1236 void inet_unregister_protosw(struct inet_protosw *p)
1237 {
1238 	if (INET_PROTOSW_PERMANENT & p->flags) {
1239 		pr_err("Attempt to unregister permanent protocol %d\n",
1240 		       p->protocol);
1241 	} else {
1242 		spin_lock_bh(&inetsw_lock);
1243 		list_del_rcu(&p->list);
1244 		spin_unlock_bh(&inetsw_lock);
1245 
1246 		synchronize_net();
1247 	}
1248 }
1249 EXPORT_SYMBOL(inet_unregister_protosw);
1250 
1251 static int inet_sk_reselect_saddr(struct sock *sk)
1252 {
1253 	struct inet_sock *inet = inet_sk(sk);
1254 	__be32 old_saddr = inet->inet_saddr;
1255 	__be32 daddr = inet->inet_daddr;
1256 	struct flowi4 *fl4;
1257 	struct rtable *rt;
1258 	__be32 new_saddr;
1259 	struct ip_options_rcu *inet_opt;
1260 	int err;
1261 
1262 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1263 					     lockdep_sock_is_held(sk));
1264 	if (inet_opt && inet_opt->opt.srr)
1265 		daddr = inet_opt->opt.faddr;
1266 
1267 	/* Query new route. */
1268 	fl4 = &inet->cork.fl.u.ip4;
1269 	rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1270 			      sk->sk_protocol, inet->inet_sport,
1271 			      inet->inet_dport, sk);
1272 	if (IS_ERR(rt))
1273 		return PTR_ERR(rt);
1274 
1275 	new_saddr = fl4->saddr;
1276 
1277 	if (new_saddr == old_saddr) {
1278 		sk_setup_caps(sk, &rt->dst);
1279 		return 0;
1280 	}
1281 
1282 	err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1283 	if (err) {
1284 		ip_rt_put(rt);
1285 		return err;
1286 	}
1287 
1288 	sk_setup_caps(sk, &rt->dst);
1289 
1290 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1291 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1292 			__func__, &old_saddr, &new_saddr);
1293 	}
1294 
1295 	/*
1296 	 * XXX The only one ugly spot where we need to
1297 	 * XXX really change the sockets identity after
1298 	 * XXX it has entered the hashes. -DaveM
1299 	 *
1300 	 * Besides that, it does not check for connection
1301 	 * uniqueness. Wait for troubles.
1302 	 */
1303 	return __sk_prot_rehash(sk);
1304 }
1305 
1306 int inet_sk_rebuild_header(struct sock *sk)
1307 {
1308 	struct inet_sock *inet = inet_sk(sk);
1309 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1310 	__be32 daddr;
1311 	struct ip_options_rcu *inet_opt;
1312 	struct flowi4 *fl4;
1313 	int err;
1314 
1315 	/* Route is OK, nothing to do. */
1316 	if (rt)
1317 		return 0;
1318 
1319 	/* Reroute. */
1320 	rcu_read_lock();
1321 	inet_opt = rcu_dereference(inet->inet_opt);
1322 	daddr = inet->inet_daddr;
1323 	if (inet_opt && inet_opt->opt.srr)
1324 		daddr = inet_opt->opt.faddr;
1325 	rcu_read_unlock();
1326 	fl4 = &inet->cork.fl.u.ip4;
1327 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1328 				   inet->inet_dport, inet->inet_sport,
1329 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1330 				   sk->sk_bound_dev_if);
1331 	if (!IS_ERR(rt)) {
1332 		err = 0;
1333 		sk_setup_caps(sk, &rt->dst);
1334 	} else {
1335 		err = PTR_ERR(rt);
1336 
1337 		/* Routing failed... */
1338 		sk->sk_route_caps = 0;
1339 		/*
1340 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1341 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1342 		 */
1343 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1344 		    sk->sk_state != TCP_SYN_SENT ||
1345 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1346 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1347 			WRITE_ONCE(sk->sk_err_soft, -err);
1348 	}
1349 
1350 	return err;
1351 }
1352 EXPORT_SYMBOL(inet_sk_rebuild_header);
1353 
1354 void inet_sk_set_state(struct sock *sk, int state)
1355 {
1356 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1357 	sk->sk_state = state;
1358 }
1359 EXPORT_SYMBOL(inet_sk_set_state);
1360 
1361 void inet_sk_state_store(struct sock *sk, int newstate)
1362 {
1363 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1364 	smp_store_release(&sk->sk_state, newstate);
1365 }
1366 
1367 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1368 				 netdev_features_t features)
1369 {
1370 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1371 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1372 	const struct net_offload *ops;
1373 	unsigned int offset = 0;
1374 	struct iphdr *iph;
1375 	int proto, tot_len;
1376 	int nhoff;
1377 	int ihl;
1378 	int id;
1379 
1380 	skb_reset_network_header(skb);
1381 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1382 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1383 		goto out;
1384 
1385 	iph = ip_hdr(skb);
1386 	ihl = iph->ihl * 4;
1387 	if (ihl < sizeof(*iph))
1388 		goto out;
1389 
1390 	id = ntohs(iph->id);
1391 	proto = iph->protocol;
1392 
1393 	/* Warning: after this point, iph might be no longer valid */
1394 	if (unlikely(!pskb_may_pull(skb, ihl)))
1395 		goto out;
1396 	__skb_pull(skb, ihl);
1397 
1398 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1399 	if (encap)
1400 		features &= skb->dev->hw_enc_features;
1401 	SKB_GSO_CB(skb)->encap_level += ihl;
1402 
1403 	skb_reset_transport_header(skb);
1404 
1405 	segs = ERR_PTR(-EPROTONOSUPPORT);
1406 
1407 	if (!skb->encapsulation || encap) {
1408 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1409 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1410 
1411 		/* fixed ID is invalid if DF bit is not set */
1412 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1413 			goto out;
1414 	}
1415 
1416 	ops = rcu_dereference(inet_offloads[proto]);
1417 	if (likely(ops && ops->callbacks.gso_segment)) {
1418 		segs = ops->callbacks.gso_segment(skb, features);
1419 		if (!segs)
1420 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1421 	}
1422 
1423 	if (IS_ERR_OR_NULL(segs))
1424 		goto out;
1425 
1426 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1427 
1428 	skb = segs;
1429 	do {
1430 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1431 		if (udpfrag) {
1432 			iph->frag_off = htons(offset >> 3);
1433 			if (skb->next)
1434 				iph->frag_off |= htons(IP_MF);
1435 			offset += skb->len - nhoff - ihl;
1436 			tot_len = skb->len - nhoff;
1437 		} else if (skb_is_gso(skb)) {
1438 			if (!fixedid) {
1439 				iph->id = htons(id);
1440 				id += skb_shinfo(skb)->gso_segs;
1441 			}
1442 
1443 			if (gso_partial)
1444 				tot_len = skb_shinfo(skb)->gso_size +
1445 					  SKB_GSO_CB(skb)->data_offset +
1446 					  skb->head - (unsigned char *)iph;
1447 			else
1448 				tot_len = skb->len - nhoff;
1449 		} else {
1450 			if (!fixedid)
1451 				iph->id = htons(id++);
1452 			tot_len = skb->len - nhoff;
1453 		}
1454 		iph->tot_len = htons(tot_len);
1455 		ip_send_check(iph);
1456 		if (encap)
1457 			skb_reset_inner_headers(skb);
1458 		skb->network_header = (u8 *)iph - skb->head;
1459 		skb_reset_mac_len(skb);
1460 	} while ((skb = skb->next));
1461 
1462 out:
1463 	return segs;
1464 }
1465 
1466 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1467 					netdev_features_t features)
1468 {
1469 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1470 		return ERR_PTR(-EINVAL);
1471 
1472 	return inet_gso_segment(skb, features);
1473 }
1474 
1475 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1476 {
1477 	const struct net_offload *ops;
1478 	struct sk_buff *pp = NULL;
1479 	const struct iphdr *iph;
1480 	struct sk_buff *p;
1481 	unsigned int hlen;
1482 	unsigned int off;
1483 	unsigned int id;
1484 	int flush = 1;
1485 	int proto;
1486 
1487 	off = skb_gro_offset(skb);
1488 	hlen = off + sizeof(*iph);
1489 	iph = skb_gro_header(skb, hlen, off);
1490 	if (unlikely(!iph))
1491 		goto out;
1492 
1493 	proto = iph->protocol;
1494 
1495 	ops = rcu_dereference(inet_offloads[proto]);
1496 	if (!ops || !ops->callbacks.gro_receive)
1497 		goto out;
1498 
1499 	if (*(u8 *)iph != 0x45)
1500 		goto out;
1501 
1502 	if (ip_is_fragment(iph))
1503 		goto out;
1504 
1505 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1506 		goto out;
1507 
1508 	NAPI_GRO_CB(skb)->proto = proto;
1509 	id = ntohl(*(__be32 *)&iph->id);
1510 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1511 	id >>= 16;
1512 
1513 	list_for_each_entry(p, head, list) {
1514 		struct iphdr *iph2;
1515 		u16 flush_id;
1516 
1517 		if (!NAPI_GRO_CB(p)->same_flow)
1518 			continue;
1519 
1520 		iph2 = (struct iphdr *)(p->data + off);
1521 		/* The above works because, with the exception of the top
1522 		 * (inner most) layer, we only aggregate pkts with the same
1523 		 * hdr length so all the hdrs we'll need to verify will start
1524 		 * at the same offset.
1525 		 */
1526 		if ((iph->protocol ^ iph2->protocol) |
1527 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1528 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1529 			NAPI_GRO_CB(p)->same_flow = 0;
1530 			continue;
1531 		}
1532 
1533 		/* All fields must match except length and checksum. */
1534 		NAPI_GRO_CB(p)->flush |=
1535 			(iph->ttl ^ iph2->ttl) |
1536 			(iph->tos ^ iph2->tos) |
1537 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1538 
1539 		NAPI_GRO_CB(p)->flush |= flush;
1540 
1541 		/* We need to store of the IP ID check to be included later
1542 		 * when we can verify that this packet does in fact belong
1543 		 * to a given flow.
1544 		 */
1545 		flush_id = (u16)(id - ntohs(iph2->id));
1546 
1547 		/* This bit of code makes it much easier for us to identify
1548 		 * the cases where we are doing atomic vs non-atomic IP ID
1549 		 * checks.  Specifically an atomic check can return IP ID
1550 		 * values 0 - 0xFFFF, while a non-atomic check can only
1551 		 * return 0 or 0xFFFF.
1552 		 */
1553 		if (!NAPI_GRO_CB(p)->is_atomic ||
1554 		    !(iph->frag_off & htons(IP_DF))) {
1555 			flush_id ^= NAPI_GRO_CB(p)->count;
1556 			flush_id = flush_id ? 0xFFFF : 0;
1557 		}
1558 
1559 		/* If the previous IP ID value was based on an atomic
1560 		 * datagram we can overwrite the value and ignore it.
1561 		 */
1562 		if (NAPI_GRO_CB(skb)->is_atomic)
1563 			NAPI_GRO_CB(p)->flush_id = flush_id;
1564 		else
1565 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1566 	}
1567 
1568 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1569 	NAPI_GRO_CB(skb)->flush |= flush;
1570 	skb_set_network_header(skb, off);
1571 	/* The above will be needed by the transport layer if there is one
1572 	 * immediately following this IP hdr.
1573 	 */
1574 
1575 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1576 	 * as we already checked checksum over ipv4 header was 0
1577 	 */
1578 	skb_gro_pull(skb, sizeof(*iph));
1579 	skb_set_transport_header(skb, skb_gro_offset(skb));
1580 
1581 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1582 				       ops->callbacks.gro_receive, head, skb);
1583 
1584 out:
1585 	skb_gro_flush_final(skb, pp, flush);
1586 
1587 	return pp;
1588 }
1589 
1590 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1591 					struct sk_buff *skb)
1592 {
1593 	if (NAPI_GRO_CB(skb)->encap_mark) {
1594 		NAPI_GRO_CB(skb)->flush = 1;
1595 		return NULL;
1596 	}
1597 
1598 	NAPI_GRO_CB(skb)->encap_mark = 1;
1599 
1600 	return inet_gro_receive(head, skb);
1601 }
1602 
1603 #define SECONDS_PER_DAY	86400
1604 
1605 /* inet_current_timestamp - Return IP network timestamp
1606  *
1607  * Return milliseconds since midnight in network byte order.
1608  */
1609 __be32 inet_current_timestamp(void)
1610 {
1611 	u32 secs;
1612 	u32 msecs;
1613 	struct timespec64 ts;
1614 
1615 	ktime_get_real_ts64(&ts);
1616 
1617 	/* Get secs since midnight. */
1618 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1619 	/* Convert to msecs. */
1620 	msecs = secs * MSEC_PER_SEC;
1621 	/* Convert nsec to msec. */
1622 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1623 
1624 	/* Convert to network byte order. */
1625 	return htonl(msecs);
1626 }
1627 EXPORT_SYMBOL(inet_current_timestamp);
1628 
1629 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1630 {
1631 	if (sk->sk_family == AF_INET)
1632 		return ip_recv_error(sk, msg, len, addr_len);
1633 #if IS_ENABLED(CONFIG_IPV6)
1634 	if (sk->sk_family == AF_INET6)
1635 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1636 #endif
1637 	return -EINVAL;
1638 }
1639 EXPORT_SYMBOL(inet_recv_error);
1640 
1641 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1642 {
1643 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1644 	const struct net_offload *ops;
1645 	__be16 totlen = iph->tot_len;
1646 	int proto = iph->protocol;
1647 	int err = -ENOSYS;
1648 
1649 	if (skb->encapsulation) {
1650 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1651 		skb_set_inner_network_header(skb, nhoff);
1652 	}
1653 
1654 	iph_set_totlen(iph, skb->len - nhoff);
1655 	csum_replace2(&iph->check, totlen, iph->tot_len);
1656 
1657 	ops = rcu_dereference(inet_offloads[proto]);
1658 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1659 		goto out;
1660 
1661 	/* Only need to add sizeof(*iph) to get to the next hdr below
1662 	 * because any hdr with option will have been flushed in
1663 	 * inet_gro_receive().
1664 	 */
1665 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1666 			      tcp4_gro_complete, udp4_gro_complete,
1667 			      skb, nhoff + sizeof(*iph));
1668 
1669 out:
1670 	return err;
1671 }
1672 
1673 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1674 {
1675 	skb->encapsulation = 1;
1676 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1677 	return inet_gro_complete(skb, nhoff);
1678 }
1679 
1680 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1681 			 unsigned short type, unsigned char protocol,
1682 			 struct net *net)
1683 {
1684 	struct socket *sock;
1685 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1686 
1687 	if (rc == 0) {
1688 		*sk = sock->sk;
1689 		(*sk)->sk_allocation = GFP_ATOMIC;
1690 		(*sk)->sk_use_task_frag = false;
1691 		/*
1692 		 * Unhash it so that IP input processing does not even see it,
1693 		 * we do not wish this socket to see incoming packets.
1694 		 */
1695 		(*sk)->sk_prot->unhash(*sk);
1696 	}
1697 	return rc;
1698 }
1699 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1700 
1701 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1702 {
1703 	unsigned long res = 0;
1704 	int i;
1705 
1706 	for_each_possible_cpu(i)
1707 		res += snmp_get_cpu_field(mib, i, offt);
1708 	return res;
1709 }
1710 EXPORT_SYMBOL_GPL(snmp_fold_field);
1711 
1712 #if BITS_PER_LONG==32
1713 
1714 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1715 			 size_t syncp_offset)
1716 {
1717 	void *bhptr;
1718 	struct u64_stats_sync *syncp;
1719 	u64 v;
1720 	unsigned int start;
1721 
1722 	bhptr = per_cpu_ptr(mib, cpu);
1723 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1724 	do {
1725 		start = u64_stats_fetch_begin(syncp);
1726 		v = *(((u64 *)bhptr) + offt);
1727 	} while (u64_stats_fetch_retry(syncp, start));
1728 
1729 	return v;
1730 }
1731 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1732 
1733 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1734 {
1735 	u64 res = 0;
1736 	int cpu;
1737 
1738 	for_each_possible_cpu(cpu) {
1739 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1740 	}
1741 	return res;
1742 }
1743 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1744 #endif
1745 
1746 #ifdef CONFIG_IP_MULTICAST
1747 static const struct net_protocol igmp_protocol = {
1748 	.handler =	igmp_rcv,
1749 };
1750 #endif
1751 
1752 static const struct net_protocol tcp_protocol = {
1753 	.handler	=	tcp_v4_rcv,
1754 	.err_handler	=	tcp_v4_err,
1755 	.no_policy	=	1,
1756 	.icmp_strict_tag_validation = 1,
1757 };
1758 
1759 static const struct net_protocol udp_protocol = {
1760 	.handler =	udp_rcv,
1761 	.err_handler =	udp_err,
1762 	.no_policy =	1,
1763 };
1764 
1765 static const struct net_protocol icmp_protocol = {
1766 	.handler =	icmp_rcv,
1767 	.err_handler =	icmp_err,
1768 	.no_policy =	1,
1769 };
1770 
1771 static __net_init int ipv4_mib_init_net(struct net *net)
1772 {
1773 	int i;
1774 
1775 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1776 	if (!net->mib.tcp_statistics)
1777 		goto err_tcp_mib;
1778 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1779 	if (!net->mib.ip_statistics)
1780 		goto err_ip_mib;
1781 
1782 	for_each_possible_cpu(i) {
1783 		struct ipstats_mib *af_inet_stats;
1784 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1785 		u64_stats_init(&af_inet_stats->syncp);
1786 	}
1787 
1788 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1789 	if (!net->mib.net_statistics)
1790 		goto err_net_mib;
1791 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1792 	if (!net->mib.udp_statistics)
1793 		goto err_udp_mib;
1794 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1795 	if (!net->mib.udplite_statistics)
1796 		goto err_udplite_mib;
1797 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1798 	if (!net->mib.icmp_statistics)
1799 		goto err_icmp_mib;
1800 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1801 					      GFP_KERNEL);
1802 	if (!net->mib.icmpmsg_statistics)
1803 		goto err_icmpmsg_mib;
1804 
1805 	tcp_mib_init(net);
1806 	return 0;
1807 
1808 err_icmpmsg_mib:
1809 	free_percpu(net->mib.icmp_statistics);
1810 err_icmp_mib:
1811 	free_percpu(net->mib.udplite_statistics);
1812 err_udplite_mib:
1813 	free_percpu(net->mib.udp_statistics);
1814 err_udp_mib:
1815 	free_percpu(net->mib.net_statistics);
1816 err_net_mib:
1817 	free_percpu(net->mib.ip_statistics);
1818 err_ip_mib:
1819 	free_percpu(net->mib.tcp_statistics);
1820 err_tcp_mib:
1821 	return -ENOMEM;
1822 }
1823 
1824 static __net_exit void ipv4_mib_exit_net(struct net *net)
1825 {
1826 	kfree(net->mib.icmpmsg_statistics);
1827 	free_percpu(net->mib.icmp_statistics);
1828 	free_percpu(net->mib.udplite_statistics);
1829 	free_percpu(net->mib.udp_statistics);
1830 	free_percpu(net->mib.net_statistics);
1831 	free_percpu(net->mib.ip_statistics);
1832 	free_percpu(net->mib.tcp_statistics);
1833 #ifdef CONFIG_MPTCP
1834 	/* allocated on demand, see mptcp_init_sock() */
1835 	free_percpu(net->mib.mptcp_statistics);
1836 #endif
1837 }
1838 
1839 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1840 	.init = ipv4_mib_init_net,
1841 	.exit = ipv4_mib_exit_net,
1842 };
1843 
1844 static int __init init_ipv4_mibs(void)
1845 {
1846 	return register_pernet_subsys(&ipv4_mib_ops);
1847 }
1848 
1849 static __net_init int inet_init_net(struct net *net)
1850 {
1851 	/*
1852 	 * Set defaults for local port range
1853 	 */
1854 	net->ipv4.ip_local_ports.range = 60999u << 16 | 32768u;
1855 
1856 	seqlock_init(&net->ipv4.ping_group_range.lock);
1857 	/*
1858 	 * Sane defaults - nobody may create ping sockets.
1859 	 * Boot scripts should set this to distro-specific group.
1860 	 */
1861 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1862 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1863 
1864 	/* Default values for sysctl-controlled parameters.
1865 	 * We set them here, in case sysctl is not compiled.
1866 	 */
1867 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1868 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1869 	net->ipv4.sysctl_ip_dynaddr = 0;
1870 	net->ipv4.sysctl_ip_early_demux = 1;
1871 	net->ipv4.sysctl_udp_early_demux = 1;
1872 	net->ipv4.sysctl_tcp_early_demux = 1;
1873 	net->ipv4.sysctl_nexthop_compat_mode = 1;
1874 #ifdef CONFIG_SYSCTL
1875 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1876 #endif
1877 
1878 	/* Some igmp sysctl, whose values are always used */
1879 	net->ipv4.sysctl_igmp_max_memberships = 20;
1880 	net->ipv4.sysctl_igmp_max_msf = 10;
1881 	/* IGMP reports for link-local multicast groups are enabled by default */
1882 	net->ipv4.sysctl_igmp_llm_reports = 1;
1883 	net->ipv4.sysctl_igmp_qrv = 2;
1884 
1885 	net->ipv4.sysctl_fib_notify_on_flag_change = 0;
1886 
1887 	return 0;
1888 }
1889 
1890 static __net_initdata struct pernet_operations af_inet_ops = {
1891 	.init = inet_init_net,
1892 };
1893 
1894 static int __init init_inet_pernet_ops(void)
1895 {
1896 	return register_pernet_subsys(&af_inet_ops);
1897 }
1898 
1899 static int ipv4_proc_init(void);
1900 
1901 /*
1902  *	IP protocol layer initialiser
1903  */
1904 
1905 static struct packet_offload ip_packet_offload __read_mostly = {
1906 	.type = cpu_to_be16(ETH_P_IP),
1907 	.callbacks = {
1908 		.gso_segment = inet_gso_segment,
1909 		.gro_receive = inet_gro_receive,
1910 		.gro_complete = inet_gro_complete,
1911 	},
1912 };
1913 
1914 static const struct net_offload ipip_offload = {
1915 	.callbacks = {
1916 		.gso_segment	= ipip_gso_segment,
1917 		.gro_receive	= ipip_gro_receive,
1918 		.gro_complete	= ipip_gro_complete,
1919 	},
1920 };
1921 
1922 static int __init ipip_offload_init(void)
1923 {
1924 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1925 }
1926 
1927 static int __init ipv4_offload_init(void)
1928 {
1929 	/*
1930 	 * Add offloads
1931 	 */
1932 	if (udpv4_offload_init() < 0)
1933 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1934 	if (tcpv4_offload_init() < 0)
1935 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1936 	if (ipip_offload_init() < 0)
1937 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1938 
1939 	dev_add_offload(&ip_packet_offload);
1940 	return 0;
1941 }
1942 
1943 fs_initcall(ipv4_offload_init);
1944 
1945 static struct packet_type ip_packet_type __read_mostly = {
1946 	.type = cpu_to_be16(ETH_P_IP),
1947 	.func = ip_rcv,
1948 	.list_func = ip_list_rcv,
1949 };
1950 
1951 static int __init inet_init(void)
1952 {
1953 	struct inet_protosw *q;
1954 	struct list_head *r;
1955 	int rc;
1956 
1957 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1958 
1959 	raw_hashinfo_init(&raw_v4_hashinfo);
1960 
1961 	rc = proto_register(&tcp_prot, 1);
1962 	if (rc)
1963 		goto out;
1964 
1965 	rc = proto_register(&udp_prot, 1);
1966 	if (rc)
1967 		goto out_unregister_tcp_proto;
1968 
1969 	rc = proto_register(&raw_prot, 1);
1970 	if (rc)
1971 		goto out_unregister_udp_proto;
1972 
1973 	rc = proto_register(&ping_prot, 1);
1974 	if (rc)
1975 		goto out_unregister_raw_proto;
1976 
1977 	/*
1978 	 *	Tell SOCKET that we are alive...
1979 	 */
1980 
1981 	(void)sock_register(&inet_family_ops);
1982 
1983 #ifdef CONFIG_SYSCTL
1984 	ip_static_sysctl_init();
1985 #endif
1986 
1987 	/*
1988 	 *	Add all the base protocols.
1989 	 */
1990 
1991 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1992 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1993 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1994 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1995 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1996 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1997 #ifdef CONFIG_IP_MULTICAST
1998 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1999 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
2000 #endif
2001 
2002 	/* Register the socket-side information for inet_create. */
2003 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
2004 		INIT_LIST_HEAD(r);
2005 
2006 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
2007 		inet_register_protosw(q);
2008 
2009 	/*
2010 	 *	Set the ARP module up
2011 	 */
2012 
2013 	arp_init();
2014 
2015 	/*
2016 	 *	Set the IP module up
2017 	 */
2018 
2019 	ip_init();
2020 
2021 	/* Initialise per-cpu ipv4 mibs */
2022 	if (init_ipv4_mibs())
2023 		panic("%s: Cannot init ipv4 mibs\n", __func__);
2024 
2025 	/* Setup TCP slab cache for open requests. */
2026 	tcp_init();
2027 
2028 	/* Setup UDP memory threshold */
2029 	udp_init();
2030 
2031 	/* Add UDP-Lite (RFC 3828) */
2032 	udplite4_register();
2033 
2034 	raw_init();
2035 
2036 	ping_init();
2037 
2038 	/*
2039 	 *	Set the ICMP layer up
2040 	 */
2041 
2042 	if (icmp_init() < 0)
2043 		panic("Failed to create the ICMP control socket.\n");
2044 
2045 	/*
2046 	 *	Initialise the multicast router
2047 	 */
2048 #if defined(CONFIG_IP_MROUTE)
2049 	if (ip_mr_init())
2050 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2051 #endif
2052 
2053 	if (init_inet_pernet_ops())
2054 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2055 
2056 	ipv4_proc_init();
2057 
2058 	ipfrag_init();
2059 
2060 	dev_add_pack(&ip_packet_type);
2061 
2062 	ip_tunnel_core_init();
2063 
2064 	rc = 0;
2065 out:
2066 	return rc;
2067 out_unregister_raw_proto:
2068 	proto_unregister(&raw_prot);
2069 out_unregister_udp_proto:
2070 	proto_unregister(&udp_prot);
2071 out_unregister_tcp_proto:
2072 	proto_unregister(&tcp_prot);
2073 	goto out;
2074 }
2075 
2076 fs_initcall(inet_init);
2077 
2078 /* ------------------------------------------------------------------------ */
2079 
2080 #ifdef CONFIG_PROC_FS
2081 static int __init ipv4_proc_init(void)
2082 {
2083 	int rc = 0;
2084 
2085 	if (raw_proc_init())
2086 		goto out_raw;
2087 	if (tcp4_proc_init())
2088 		goto out_tcp;
2089 	if (udp4_proc_init())
2090 		goto out_udp;
2091 	if (ping_proc_init())
2092 		goto out_ping;
2093 	if (ip_misc_proc_init())
2094 		goto out_misc;
2095 out:
2096 	return rc;
2097 out_misc:
2098 	ping_proc_exit();
2099 out_ping:
2100 	udp4_proc_exit();
2101 out_udp:
2102 	tcp4_proc_exit();
2103 out_tcp:
2104 	raw_proc_exit();
2105 out_raw:
2106 	rc = -ENOMEM;
2107 	goto out;
2108 }
2109 
2110 #else /* CONFIG_PROC_FS */
2111 static int __init ipv4_proc_init(void)
2112 {
2113 	return 0;
2114 }
2115 #endif /* CONFIG_PROC_FS */
2116