xref: /linux/net/ipv4/af_inet.c (revision e6a901a00822659181c93c86d8bbc2a17779fddc)
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 #include <net/rps.h>
123 
124 #include <trace/events/sock.h>
125 
126 /* The inetsw table contains everything that inet_create needs to
127  * build a new socket.
128  */
129 static struct list_head inetsw[SOCK_MAX];
130 static DEFINE_SPINLOCK(inetsw_lock);
131 
132 /* New destruction routine */
133 
134 void inet_sock_destruct(struct sock *sk)
135 {
136 	struct inet_sock *inet = inet_sk(sk);
137 
138 	__skb_queue_purge(&sk->sk_receive_queue);
139 	__skb_queue_purge(&sk->sk_error_queue);
140 
141 	sk_mem_reclaim_final(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_ONCE(atomic_read(&sk->sk_rmem_alloc));
154 	WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc));
155 	WARN_ON_ONCE(sk->sk_wmem_queued);
156 	WARN_ON_ONCE(sk_forward_alloc_get(sk));
157 
158 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
159 	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
160 	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
161 }
162 EXPORT_SYMBOL(inet_sock_destruct);
163 
164 /*
165  *	The routines beyond this point handle the behaviour of an AF_INET
166  *	socket object. Mostly it punts to the subprotocols of IP to do
167  *	the work.
168  */
169 
170 /*
171  *	Automatically bind an unbound socket.
172  */
173 
174 static int inet_autobind(struct sock *sk)
175 {
176 	struct inet_sock *inet;
177 	/* We may need to bind the socket. */
178 	lock_sock(sk);
179 	inet = inet_sk(sk);
180 	if (!inet->inet_num) {
181 		if (sk->sk_prot->get_port(sk, 0)) {
182 			release_sock(sk);
183 			return -EAGAIN;
184 		}
185 		inet->inet_sport = htons(inet->inet_num);
186 	}
187 	release_sock(sk);
188 	return 0;
189 }
190 
191 int __inet_listen_sk(struct sock *sk, int backlog)
192 {
193 	unsigned char old_state = sk->sk_state;
194 	int err, tcp_fastopen;
195 
196 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
197 		return -EINVAL;
198 
199 	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
200 	/* Really, if the socket is already in listen state
201 	 * we can only allow the backlog to be adjusted.
202 	 */
203 	if (old_state != TCP_LISTEN) {
204 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
205 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
206 		 * Also fastopen backlog may already been set via the option
207 		 * because the socket was in TCP_LISTEN state previously but
208 		 * was shutdown() rather than close().
209 		 */
210 		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
211 		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
212 		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
213 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
214 			fastopen_queue_tune(sk, backlog);
215 			tcp_fastopen_init_key_once(sock_net(sk));
216 		}
217 
218 		err = inet_csk_listen_start(sk);
219 		if (err)
220 			return err;
221 
222 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
223 	}
224 	return 0;
225 }
226 
227 /*
228  *	Move a socket into listening state.
229  */
230 int inet_listen(struct socket *sock, int backlog)
231 {
232 	struct sock *sk = sock->sk;
233 	int err = -EINVAL;
234 
235 	lock_sock(sk);
236 
237 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
238 		goto out;
239 
240 	err = __inet_listen_sk(sk, backlog);
241 
242 out:
243 	release_sock(sk);
244 	return err;
245 }
246 EXPORT_SYMBOL(inet_listen);
247 
248 /*
249  *	Create an inet socket.
250  */
251 
252 static int inet_create(struct net *net, struct socket *sock, int protocol,
253 		       int kern)
254 {
255 	struct sock *sk;
256 	struct inet_protosw *answer;
257 	struct inet_sock *inet;
258 	struct proto *answer_prot;
259 	unsigned char answer_flags;
260 	int try_loading_module = 0;
261 	int err;
262 
263 	if (protocol < 0 || protocol >= IPPROTO_MAX)
264 		return -EINVAL;
265 
266 	sock->state = SS_UNCONNECTED;
267 
268 	/* Look for the requested type/protocol pair. */
269 lookup_protocol:
270 	err = -ESOCKTNOSUPPORT;
271 	rcu_read_lock();
272 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
273 
274 		err = 0;
275 		/* Check the non-wild match. */
276 		if (protocol == answer->protocol) {
277 			if (protocol != IPPROTO_IP)
278 				break;
279 		} else {
280 			/* Check for the two wild cases. */
281 			if (IPPROTO_IP == protocol) {
282 				protocol = answer->protocol;
283 				break;
284 			}
285 			if (IPPROTO_IP == answer->protocol)
286 				break;
287 		}
288 		err = -EPROTONOSUPPORT;
289 	}
290 
291 	if (unlikely(err)) {
292 		if (try_loading_module < 2) {
293 			rcu_read_unlock();
294 			/*
295 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
296 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
297 			 */
298 			if (++try_loading_module == 1)
299 				request_module("net-pf-%d-proto-%d-type-%d",
300 					       PF_INET, protocol, sock->type);
301 			/*
302 			 * Fall back to generic, e.g. net-pf-2-proto-132
303 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
304 			 */
305 			else
306 				request_module("net-pf-%d-proto-%d",
307 					       PF_INET, protocol);
308 			goto lookup_protocol;
309 		} else
310 			goto out_rcu_unlock;
311 	}
312 
313 	err = -EPERM;
314 	if (sock->type == SOCK_RAW && !kern &&
315 	    !ns_capable(net->user_ns, CAP_NET_RAW))
316 		goto out_rcu_unlock;
317 
318 	sock->ops = answer->ops;
319 	answer_prot = answer->prot;
320 	answer_flags = answer->flags;
321 	rcu_read_unlock();
322 
323 	WARN_ON(!answer_prot->slab);
324 
325 	err = -ENOMEM;
326 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
327 	if (!sk)
328 		goto out;
329 
330 	err = 0;
331 	if (INET_PROTOSW_REUSE & answer_flags)
332 		sk->sk_reuse = SK_CAN_REUSE;
333 
334 	if (INET_PROTOSW_ICSK & answer_flags)
335 		inet_init_csk_locks(sk);
336 
337 	inet = inet_sk(sk);
338 	inet_assign_bit(IS_ICSK, sk, INET_PROTOSW_ICSK & answer_flags);
339 
340 	inet_clear_bit(NODEFRAG, sk);
341 
342 	if (SOCK_RAW == sock->type) {
343 		inet->inet_num = protocol;
344 		if (IPPROTO_RAW == protocol)
345 			inet_set_bit(HDRINCL, sk);
346 	}
347 
348 	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
349 		inet->pmtudisc = IP_PMTUDISC_DONT;
350 	else
351 		inet->pmtudisc = IP_PMTUDISC_WANT;
352 
353 	atomic_set(&inet->inet_id, 0);
354 
355 	sock_init_data(sock, sk);
356 
357 	sk->sk_destruct	   = inet_sock_destruct;
358 	sk->sk_protocol	   = protocol;
359 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
360 	sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
361 
362 	inet->uc_ttl	= -1;
363 	inet_set_bit(MC_LOOP, sk);
364 	inet->mc_ttl	= 1;
365 	inet_set_bit(MC_ALL, sk);
366 	inet->mc_index	= 0;
367 	inet->mc_list	= NULL;
368 	inet->rcv_tos	= 0;
369 
370 	if (inet->inet_num) {
371 		/* It assumes that any protocol which allows
372 		 * the user to assign a number at socket
373 		 * creation time automatically
374 		 * shares.
375 		 */
376 		inet->inet_sport = htons(inet->inet_num);
377 		/* Add to protocol hash chains. */
378 		err = sk->sk_prot->hash(sk);
379 		if (err) {
380 			sk_common_release(sk);
381 			goto out;
382 		}
383 	}
384 
385 	if (sk->sk_prot->init) {
386 		err = sk->sk_prot->init(sk);
387 		if (err) {
388 			sk_common_release(sk);
389 			goto out;
390 		}
391 	}
392 
393 	if (!kern) {
394 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
395 		if (err) {
396 			sk_common_release(sk);
397 			goto out;
398 		}
399 	}
400 out:
401 	return err;
402 out_rcu_unlock:
403 	rcu_read_unlock();
404 	goto out;
405 }
406 
407 
408 /*
409  *	The peer socket should always be NULL (or else). When we call this
410  *	function we are destroying the object and from then on nobody
411  *	should refer to it.
412  */
413 int inet_release(struct socket *sock)
414 {
415 	struct sock *sk = sock->sk;
416 
417 	if (sk) {
418 		long timeout;
419 
420 		if (!sk->sk_kern_sock)
421 			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
422 
423 		/* Applications forget to leave groups before exiting */
424 		ip_mc_drop_socket(sk);
425 
426 		/* If linger is set, we don't return until the close
427 		 * is complete.  Otherwise we return immediately. The
428 		 * actually closing is done the same either way.
429 		 *
430 		 * If the close is due to the process exiting, we never
431 		 * linger..
432 		 */
433 		timeout = 0;
434 		if (sock_flag(sk, SOCK_LINGER) &&
435 		    !(current->flags & PF_EXITING))
436 			timeout = sk->sk_lingertime;
437 		sk->sk_prot->close(sk, timeout);
438 		sock->sk = NULL;
439 	}
440 	return 0;
441 }
442 EXPORT_SYMBOL(inet_release);
443 
444 int inet_bind_sk(struct sock *sk, struct sockaddr *uaddr, int addr_len)
445 {
446 	u32 flags = BIND_WITH_LOCK;
447 	int err;
448 
449 	/* If the socket has its own bind function then use it. (RAW) */
450 	if (sk->sk_prot->bind) {
451 		return sk->sk_prot->bind(sk, uaddr, addr_len);
452 	}
453 	if (addr_len < sizeof(struct sockaddr_in))
454 		return -EINVAL;
455 
456 	/* BPF prog is run before any checks are done so that if the prog
457 	 * changes context in a wrong way it will be caught.
458 	 */
459 	err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr, &addr_len,
460 						 CGROUP_INET4_BIND, &flags);
461 	if (err)
462 		return err;
463 
464 	return __inet_bind(sk, uaddr, addr_len, flags);
465 }
466 
467 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
468 {
469 	return inet_bind_sk(sock->sk, uaddr, addr_len);
470 }
471 EXPORT_SYMBOL(inet_bind);
472 
473 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
474 		u32 flags)
475 {
476 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
477 	struct inet_sock *inet = inet_sk(sk);
478 	struct net *net = sock_net(sk);
479 	unsigned short snum;
480 	int chk_addr_ret;
481 	u32 tb_id = RT_TABLE_LOCAL;
482 	int err;
483 
484 	if (addr->sin_family != AF_INET) {
485 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
486 		 * only if s_addr is INADDR_ANY.
487 		 */
488 		err = -EAFNOSUPPORT;
489 		if (addr->sin_family != AF_UNSPEC ||
490 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
491 			goto out;
492 	}
493 
494 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
495 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
496 
497 	/* Not specified by any standard per-se, however it breaks too
498 	 * many applications when removed.  It is unfortunate since
499 	 * allowing applications to make a non-local bind solves
500 	 * several problems with systems using dynamic addressing.
501 	 * (ie. your servers still start up even if your ISDN link
502 	 *  is temporarily down)
503 	 */
504 	err = -EADDRNOTAVAIL;
505 	if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,
506 	                                 chk_addr_ret))
507 		goto out;
508 
509 	snum = ntohs(addr->sin_port);
510 	err = -EACCES;
511 	if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
512 	    snum && inet_port_requires_bind_service(net, snum) &&
513 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
514 		goto out;
515 
516 	/*      We keep a pair of addresses. rcv_saddr is the one
517 	 *      used by hash lookups, and saddr is used for transmit.
518 	 *
519 	 *      In the BSD API these are the same except where it
520 	 *      would be illegal to use them (multicast/broadcast) in
521 	 *      which case the sending device address is used.
522 	 */
523 	if (flags & BIND_WITH_LOCK)
524 		lock_sock(sk);
525 
526 	/* Check these errors (active socket, double bind). */
527 	err = -EINVAL;
528 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
529 		goto out_release_sock;
530 
531 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
532 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
533 		inet->inet_saddr = 0;  /* Use device */
534 
535 	/* Make sure we are allowed to bind here. */
536 	if (snum || !(inet_test_bit(BIND_ADDRESS_NO_PORT, sk) ||
537 		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
538 		err = sk->sk_prot->get_port(sk, snum);
539 		if (err) {
540 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
541 			goto out_release_sock;
542 		}
543 		if (!(flags & BIND_FROM_BPF)) {
544 			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
545 			if (err) {
546 				inet->inet_saddr = inet->inet_rcv_saddr = 0;
547 				if (sk->sk_prot->put_port)
548 					sk->sk_prot->put_port(sk);
549 				goto out_release_sock;
550 			}
551 		}
552 	}
553 
554 	if (inet->inet_rcv_saddr)
555 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
556 	if (snum)
557 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
558 	inet->inet_sport = htons(inet->inet_num);
559 	inet->inet_daddr = 0;
560 	inet->inet_dport = 0;
561 	sk_dst_reset(sk);
562 	err = 0;
563 out_release_sock:
564 	if (flags & BIND_WITH_LOCK)
565 		release_sock(sk);
566 out:
567 	return err;
568 }
569 
570 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
571 		       int addr_len, int flags)
572 {
573 	struct sock *sk = sock->sk;
574 	const struct proto *prot;
575 	int err;
576 
577 	if (addr_len < sizeof(uaddr->sa_family))
578 		return -EINVAL;
579 
580 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
581 	prot = READ_ONCE(sk->sk_prot);
582 
583 	if (uaddr->sa_family == AF_UNSPEC)
584 		return prot->disconnect(sk, flags);
585 
586 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
587 		err = prot->pre_connect(sk, uaddr, addr_len);
588 		if (err)
589 			return err;
590 	}
591 
592 	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
593 		return -EAGAIN;
594 	return prot->connect(sk, uaddr, addr_len);
595 }
596 EXPORT_SYMBOL(inet_dgram_connect);
597 
598 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
599 {
600 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
601 
602 	add_wait_queue(sk_sleep(sk), &wait);
603 	sk->sk_write_pending += writebias;
604 
605 	/* Basic assumption: if someone sets sk->sk_err, he _must_
606 	 * change state of the socket from TCP_SYN_*.
607 	 * Connect() does not allow to get error notifications
608 	 * without closing the socket.
609 	 */
610 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
611 		release_sock(sk);
612 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
613 		lock_sock(sk);
614 		if (signal_pending(current) || !timeo)
615 			break;
616 	}
617 	remove_wait_queue(sk_sleep(sk), &wait);
618 	sk->sk_write_pending -= writebias;
619 	return timeo;
620 }
621 
622 /*
623  *	Connect to a remote host. There is regrettably still a little
624  *	TCP 'magic' in here.
625  */
626 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
627 			  int addr_len, int flags, int is_sendmsg)
628 {
629 	struct sock *sk = sock->sk;
630 	int err;
631 	long timeo;
632 
633 	/*
634 	 * uaddr can be NULL and addr_len can be 0 if:
635 	 * sk is a TCP fastopen active socket and
636 	 * TCP_FASTOPEN_CONNECT sockopt is set and
637 	 * we already have a valid cookie for this socket.
638 	 * In this case, user can call write() after connect().
639 	 * write() will invoke tcp_sendmsg_fastopen() which calls
640 	 * __inet_stream_connect().
641 	 */
642 	if (uaddr) {
643 		if (addr_len < sizeof(uaddr->sa_family))
644 			return -EINVAL;
645 
646 		if (uaddr->sa_family == AF_UNSPEC) {
647 			sk->sk_disconnects++;
648 			err = sk->sk_prot->disconnect(sk, flags);
649 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
650 			goto out;
651 		}
652 	}
653 
654 	switch (sock->state) {
655 	default:
656 		err = -EINVAL;
657 		goto out;
658 	case SS_CONNECTED:
659 		err = -EISCONN;
660 		goto out;
661 	case SS_CONNECTING:
662 		if (inet_test_bit(DEFER_CONNECT, sk))
663 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
664 		else
665 			err = -EALREADY;
666 		/* Fall out of switch with err, set for this state */
667 		break;
668 	case SS_UNCONNECTED:
669 		err = -EISCONN;
670 		if (sk->sk_state != TCP_CLOSE)
671 			goto out;
672 
673 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
674 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
675 			if (err)
676 				goto out;
677 		}
678 
679 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
680 		if (err < 0)
681 			goto out;
682 
683 		sock->state = SS_CONNECTING;
684 
685 		if (!err && inet_test_bit(DEFER_CONNECT, sk))
686 			goto out;
687 
688 		/* Just entered SS_CONNECTING state; the only
689 		 * difference is that return value in non-blocking
690 		 * case is EINPROGRESS, rather than EALREADY.
691 		 */
692 		err = -EINPROGRESS;
693 		break;
694 	}
695 
696 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
697 
698 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
699 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
700 				tcp_sk(sk)->fastopen_req &&
701 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
702 		int dis = sk->sk_disconnects;
703 
704 		/* Error code is set above */
705 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
706 			goto out;
707 
708 		err = sock_intr_errno(timeo);
709 		if (signal_pending(current))
710 			goto out;
711 
712 		if (dis != sk->sk_disconnects) {
713 			err = -EPIPE;
714 			goto out;
715 		}
716 	}
717 
718 	/* Connection was closed by RST, timeout, ICMP error
719 	 * or another process disconnected us.
720 	 */
721 	if (sk->sk_state == TCP_CLOSE)
722 		goto sock_error;
723 
724 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
725 	 * and error was received after socket entered established state.
726 	 * Hence, it is handled normally after connect() return successfully.
727 	 */
728 
729 	sock->state = SS_CONNECTED;
730 	err = 0;
731 out:
732 	return err;
733 
734 sock_error:
735 	err = sock_error(sk) ? : -ECONNABORTED;
736 	sock->state = SS_UNCONNECTED;
737 	sk->sk_disconnects++;
738 	if (sk->sk_prot->disconnect(sk, flags))
739 		sock->state = SS_DISCONNECTING;
740 	goto out;
741 }
742 EXPORT_SYMBOL(__inet_stream_connect);
743 
744 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
745 			int addr_len, int flags)
746 {
747 	int err;
748 
749 	lock_sock(sock->sk);
750 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
751 	release_sock(sock->sk);
752 	return err;
753 }
754 EXPORT_SYMBOL(inet_stream_connect);
755 
756 void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
757 {
758 	sock_rps_record_flow(newsk);
759 	WARN_ON(!((1 << newsk->sk_state) &
760 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
761 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
762 
763 	if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
764 		set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
765 	sock_graft(newsk, newsock);
766 
767 	newsock->state = SS_CONNECTED;
768 }
769 
770 /*
771  *	Accept a pending connection. The TCP layer now gives BSD semantics.
772  */
773 
774 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
775 		bool kern)
776 {
777 	struct sock *sk1 = sock->sk, *sk2;
778 	int err = -EINVAL;
779 
780 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
781 	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
782 	if (!sk2)
783 		return err;
784 
785 	lock_sock(sk2);
786 	__inet_accept(sock, newsock, sk2);
787 	release_sock(sk2);
788 	return 0;
789 }
790 EXPORT_SYMBOL(inet_accept);
791 
792 /*
793  *	This does both peername and sockname.
794  */
795 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
796 		 int peer)
797 {
798 	struct sock *sk		= sock->sk;
799 	struct inet_sock *inet	= inet_sk(sk);
800 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
801 	int sin_addr_len = sizeof(*sin);
802 
803 	sin->sin_family = AF_INET;
804 	lock_sock(sk);
805 	if (peer) {
806 		if (!inet->inet_dport ||
807 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
808 		     peer == 1)) {
809 			release_sock(sk);
810 			return -ENOTCONN;
811 		}
812 		sin->sin_port = inet->inet_dport;
813 		sin->sin_addr.s_addr = inet->inet_daddr;
814 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
815 				       CGROUP_INET4_GETPEERNAME);
816 	} else {
817 		__be32 addr = inet->inet_rcv_saddr;
818 		if (!addr)
819 			addr = inet->inet_saddr;
820 		sin->sin_port = inet->inet_sport;
821 		sin->sin_addr.s_addr = addr;
822 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin, &sin_addr_len,
823 				       CGROUP_INET4_GETSOCKNAME);
824 	}
825 	release_sock(sk);
826 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
827 	return sin_addr_len;
828 }
829 EXPORT_SYMBOL(inet_getname);
830 
831 int inet_send_prepare(struct sock *sk)
832 {
833 	sock_rps_record_flow(sk);
834 
835 	/* We may need to bind the socket. */
836 	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
837 	    inet_autobind(sk))
838 		return -EAGAIN;
839 
840 	return 0;
841 }
842 EXPORT_SYMBOL_GPL(inet_send_prepare);
843 
844 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
845 {
846 	struct sock *sk = sock->sk;
847 
848 	if (unlikely(inet_send_prepare(sk)))
849 		return -EAGAIN;
850 
851 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
852 			       sk, msg, size);
853 }
854 EXPORT_SYMBOL(inet_sendmsg);
855 
856 void inet_splice_eof(struct socket *sock)
857 {
858 	const struct proto *prot;
859 	struct sock *sk = sock->sk;
860 
861 	if (unlikely(inet_send_prepare(sk)))
862 		return;
863 
864 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
865 	prot = READ_ONCE(sk->sk_prot);
866 	if (prot->splice_eof)
867 		prot->splice_eof(sock);
868 }
869 EXPORT_SYMBOL_GPL(inet_splice_eof);
870 
871 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
872 					  size_t, int, int *));
873 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
874 		 int flags)
875 {
876 	struct sock *sk = sock->sk;
877 	int addr_len = 0;
878 	int err;
879 
880 	if (likely(!(flags & MSG_ERRQUEUE)))
881 		sock_rps_record_flow(sk);
882 
883 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
884 			      sk, msg, size, flags, &addr_len);
885 	if (err >= 0)
886 		msg->msg_namelen = addr_len;
887 	return err;
888 }
889 EXPORT_SYMBOL(inet_recvmsg);
890 
891 int inet_shutdown(struct socket *sock, int how)
892 {
893 	struct sock *sk = sock->sk;
894 	int err = 0;
895 
896 	/* This should really check to make sure
897 	 * the socket is a TCP socket. (WHY AC...)
898 	 */
899 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
900 		       1->2 bit 2 snds.
901 		       2->3 */
902 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
903 		return -EINVAL;
904 
905 	lock_sock(sk);
906 	if (sock->state == SS_CONNECTING) {
907 		if ((1 << sk->sk_state) &
908 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
909 			sock->state = SS_DISCONNECTING;
910 		else
911 			sock->state = SS_CONNECTED;
912 	}
913 
914 	switch (sk->sk_state) {
915 	case TCP_CLOSE:
916 		err = -ENOTCONN;
917 		/* Hack to wake up other listeners, who can poll for
918 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
919 		fallthrough;
920 	default:
921 		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
922 		if (sk->sk_prot->shutdown)
923 			sk->sk_prot->shutdown(sk, how);
924 		break;
925 
926 	/* Remaining two branches are temporary solution for missing
927 	 * close() in multithreaded environment. It is _not_ a good idea,
928 	 * but we have no choice until close() is repaired at VFS level.
929 	 */
930 	case TCP_LISTEN:
931 		if (!(how & RCV_SHUTDOWN))
932 			break;
933 		fallthrough;
934 	case TCP_SYN_SENT:
935 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
936 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
937 		break;
938 	}
939 
940 	/* Wake up anyone sleeping in poll. */
941 	sk->sk_state_change(sk);
942 	release_sock(sk);
943 	return err;
944 }
945 EXPORT_SYMBOL(inet_shutdown);
946 
947 /*
948  *	ioctl() calls you can issue on an INET socket. Most of these are
949  *	device configuration and stuff and very rarely used. Some ioctls
950  *	pass on to the socket itself.
951  *
952  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
953  *	loads the devconfigure module does its configuring and unloads it.
954  *	There's a good 20K of config code hanging around the kernel.
955  */
956 
957 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
958 {
959 	struct sock *sk = sock->sk;
960 	int err = 0;
961 	struct net *net = sock_net(sk);
962 	void __user *p = (void __user *)arg;
963 	struct ifreq ifr;
964 	struct rtentry rt;
965 
966 	switch (cmd) {
967 	case SIOCADDRT:
968 	case SIOCDELRT:
969 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
970 			return -EFAULT;
971 		err = ip_rt_ioctl(net, cmd, &rt);
972 		break;
973 	case SIOCRTMSG:
974 		err = -EINVAL;
975 		break;
976 	case SIOCDARP:
977 	case SIOCGARP:
978 	case SIOCSARP:
979 		err = arp_ioctl(net, cmd, (void __user *)arg);
980 		break;
981 	case SIOCGIFADDR:
982 	case SIOCGIFBRDADDR:
983 	case SIOCGIFNETMASK:
984 	case SIOCGIFDSTADDR:
985 	case SIOCGIFPFLAGS:
986 		if (get_user_ifreq(&ifr, NULL, p))
987 			return -EFAULT;
988 		err = devinet_ioctl(net, cmd, &ifr);
989 		if (!err && put_user_ifreq(&ifr, p))
990 			err = -EFAULT;
991 		break;
992 
993 	case SIOCSIFADDR:
994 	case SIOCSIFBRDADDR:
995 	case SIOCSIFNETMASK:
996 	case SIOCSIFDSTADDR:
997 	case SIOCSIFPFLAGS:
998 	case SIOCSIFFLAGS:
999 		if (get_user_ifreq(&ifr, NULL, p))
1000 			return -EFAULT;
1001 		err = devinet_ioctl(net, cmd, &ifr);
1002 		break;
1003 	default:
1004 		if (sk->sk_prot->ioctl)
1005 			err = sk_ioctl(sk, cmd, (void __user *)arg);
1006 		else
1007 			err = -ENOIOCTLCMD;
1008 		break;
1009 	}
1010 	return err;
1011 }
1012 EXPORT_SYMBOL(inet_ioctl);
1013 
1014 #ifdef CONFIG_COMPAT
1015 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1016 		struct compat_rtentry __user *ur)
1017 {
1018 	compat_uptr_t rtdev;
1019 	struct rtentry rt;
1020 
1021 	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1022 			3 * sizeof(struct sockaddr)) ||
1023 	    get_user(rt.rt_flags, &ur->rt_flags) ||
1024 	    get_user(rt.rt_metric, &ur->rt_metric) ||
1025 	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1026 	    get_user(rt.rt_window, &ur->rt_window) ||
1027 	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1028 	    get_user(rtdev, &ur->rt_dev))
1029 		return -EFAULT;
1030 
1031 	rt.rt_dev = compat_ptr(rtdev);
1032 	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1033 }
1034 
1035 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1036 {
1037 	void __user *argp = compat_ptr(arg);
1038 	struct sock *sk = sock->sk;
1039 
1040 	switch (cmd) {
1041 	case SIOCADDRT:
1042 	case SIOCDELRT:
1043 		return inet_compat_routing_ioctl(sk, cmd, argp);
1044 	default:
1045 		if (!sk->sk_prot->compat_ioctl)
1046 			return -ENOIOCTLCMD;
1047 		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1048 	}
1049 }
1050 #endif /* CONFIG_COMPAT */
1051 
1052 const struct proto_ops inet_stream_ops = {
1053 	.family		   = PF_INET,
1054 	.owner		   = THIS_MODULE,
1055 	.release	   = inet_release,
1056 	.bind		   = inet_bind,
1057 	.connect	   = inet_stream_connect,
1058 	.socketpair	   = sock_no_socketpair,
1059 	.accept		   = inet_accept,
1060 	.getname	   = inet_getname,
1061 	.poll		   = tcp_poll,
1062 	.ioctl		   = inet_ioctl,
1063 	.gettstamp	   = sock_gettstamp,
1064 	.listen		   = inet_listen,
1065 	.shutdown	   = inet_shutdown,
1066 	.setsockopt	   = sock_common_setsockopt,
1067 	.getsockopt	   = sock_common_getsockopt,
1068 	.sendmsg	   = inet_sendmsg,
1069 	.recvmsg	   = inet_recvmsg,
1070 #ifdef CONFIG_MMU
1071 	.mmap		   = tcp_mmap,
1072 #endif
1073 	.splice_eof	   = inet_splice_eof,
1074 	.splice_read	   = tcp_splice_read,
1075 	.read_sock	   = tcp_read_sock,
1076 	.read_skb	   = tcp_read_skb,
1077 	.sendmsg_locked    = tcp_sendmsg_locked,
1078 	.peek_len	   = tcp_peek_len,
1079 #ifdef CONFIG_COMPAT
1080 	.compat_ioctl	   = inet_compat_ioctl,
1081 #endif
1082 	.set_rcvlowat	   = tcp_set_rcvlowat,
1083 };
1084 EXPORT_SYMBOL(inet_stream_ops);
1085 
1086 const struct proto_ops inet_dgram_ops = {
1087 	.family		   = PF_INET,
1088 	.owner		   = THIS_MODULE,
1089 	.release	   = inet_release,
1090 	.bind		   = inet_bind,
1091 	.connect	   = inet_dgram_connect,
1092 	.socketpair	   = sock_no_socketpair,
1093 	.accept		   = sock_no_accept,
1094 	.getname	   = inet_getname,
1095 	.poll		   = udp_poll,
1096 	.ioctl		   = inet_ioctl,
1097 	.gettstamp	   = sock_gettstamp,
1098 	.listen		   = sock_no_listen,
1099 	.shutdown	   = inet_shutdown,
1100 	.setsockopt	   = sock_common_setsockopt,
1101 	.getsockopt	   = sock_common_getsockopt,
1102 	.sendmsg	   = inet_sendmsg,
1103 	.read_skb	   = udp_read_skb,
1104 	.recvmsg	   = inet_recvmsg,
1105 	.mmap		   = sock_no_mmap,
1106 	.splice_eof	   = inet_splice_eof,
1107 	.set_peek_off	   = udp_set_peek_off,
1108 #ifdef CONFIG_COMPAT
1109 	.compat_ioctl	   = inet_compat_ioctl,
1110 #endif
1111 };
1112 EXPORT_SYMBOL(inet_dgram_ops);
1113 
1114 /*
1115  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1116  * udp_poll
1117  */
1118 static const struct proto_ops inet_sockraw_ops = {
1119 	.family		   = PF_INET,
1120 	.owner		   = THIS_MODULE,
1121 	.release	   = inet_release,
1122 	.bind		   = inet_bind,
1123 	.connect	   = inet_dgram_connect,
1124 	.socketpair	   = sock_no_socketpair,
1125 	.accept		   = sock_no_accept,
1126 	.getname	   = inet_getname,
1127 	.poll		   = datagram_poll,
1128 	.ioctl		   = inet_ioctl,
1129 	.gettstamp	   = sock_gettstamp,
1130 	.listen		   = sock_no_listen,
1131 	.shutdown	   = inet_shutdown,
1132 	.setsockopt	   = sock_common_setsockopt,
1133 	.getsockopt	   = sock_common_getsockopt,
1134 	.sendmsg	   = inet_sendmsg,
1135 	.recvmsg	   = inet_recvmsg,
1136 	.mmap		   = sock_no_mmap,
1137 	.splice_eof	   = inet_splice_eof,
1138 #ifdef CONFIG_COMPAT
1139 	.compat_ioctl	   = inet_compat_ioctl,
1140 #endif
1141 };
1142 
1143 static const struct net_proto_family inet_family_ops = {
1144 	.family = PF_INET,
1145 	.create = inet_create,
1146 	.owner	= THIS_MODULE,
1147 };
1148 
1149 /* Upon startup we insert all the elements in inetsw_array[] into
1150  * the linked list inetsw.
1151  */
1152 static struct inet_protosw inetsw_array[] =
1153 {
1154 	{
1155 		.type =       SOCK_STREAM,
1156 		.protocol =   IPPROTO_TCP,
1157 		.prot =       &tcp_prot,
1158 		.ops =        &inet_stream_ops,
1159 		.flags =      INET_PROTOSW_PERMANENT |
1160 			      INET_PROTOSW_ICSK,
1161 	},
1162 
1163 	{
1164 		.type =       SOCK_DGRAM,
1165 		.protocol =   IPPROTO_UDP,
1166 		.prot =       &udp_prot,
1167 		.ops =        &inet_dgram_ops,
1168 		.flags =      INET_PROTOSW_PERMANENT,
1169        },
1170 
1171        {
1172 		.type =       SOCK_DGRAM,
1173 		.protocol =   IPPROTO_ICMP,
1174 		.prot =       &ping_prot,
1175 		.ops =        &inet_sockraw_ops,
1176 		.flags =      INET_PROTOSW_REUSE,
1177        },
1178 
1179        {
1180 	       .type =       SOCK_RAW,
1181 	       .protocol =   IPPROTO_IP,	/* wild card */
1182 	       .prot =       &raw_prot,
1183 	       .ops =        &inet_sockraw_ops,
1184 	       .flags =      INET_PROTOSW_REUSE,
1185        }
1186 };
1187 
1188 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1189 
1190 void inet_register_protosw(struct inet_protosw *p)
1191 {
1192 	struct list_head *lh;
1193 	struct inet_protosw *answer;
1194 	int protocol = p->protocol;
1195 	struct list_head *last_perm;
1196 
1197 	spin_lock_bh(&inetsw_lock);
1198 
1199 	if (p->type >= SOCK_MAX)
1200 		goto out_illegal;
1201 
1202 	/* If we are trying to override a permanent protocol, bail. */
1203 	last_perm = &inetsw[p->type];
1204 	list_for_each(lh, &inetsw[p->type]) {
1205 		answer = list_entry(lh, struct inet_protosw, list);
1206 		/* Check only the non-wild match. */
1207 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1208 			break;
1209 		if (protocol == answer->protocol)
1210 			goto out_permanent;
1211 		last_perm = lh;
1212 	}
1213 
1214 	/* Add the new entry after the last permanent entry if any, so that
1215 	 * the new entry does not override a permanent entry when matched with
1216 	 * a wild-card protocol. But it is allowed to override any existing
1217 	 * non-permanent entry.  This means that when we remove this entry, the
1218 	 * system automatically returns to the old behavior.
1219 	 */
1220 	list_add_rcu(&p->list, last_perm);
1221 out:
1222 	spin_unlock_bh(&inetsw_lock);
1223 
1224 	return;
1225 
1226 out_permanent:
1227 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1228 	goto out;
1229 
1230 out_illegal:
1231 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1232 	       p->type);
1233 	goto out;
1234 }
1235 EXPORT_SYMBOL(inet_register_protosw);
1236 
1237 void inet_unregister_protosw(struct inet_protosw *p)
1238 {
1239 	if (INET_PROTOSW_PERMANENT & p->flags) {
1240 		pr_err("Attempt to unregister permanent protocol %d\n",
1241 		       p->protocol);
1242 	} else {
1243 		spin_lock_bh(&inetsw_lock);
1244 		list_del_rcu(&p->list);
1245 		spin_unlock_bh(&inetsw_lock);
1246 
1247 		synchronize_net();
1248 	}
1249 }
1250 EXPORT_SYMBOL(inet_unregister_protosw);
1251 
1252 static int inet_sk_reselect_saddr(struct sock *sk)
1253 {
1254 	struct inet_sock *inet = inet_sk(sk);
1255 	__be32 old_saddr = inet->inet_saddr;
1256 	__be32 daddr = inet->inet_daddr;
1257 	struct flowi4 *fl4;
1258 	struct rtable *rt;
1259 	__be32 new_saddr;
1260 	struct ip_options_rcu *inet_opt;
1261 	int err;
1262 
1263 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1264 					     lockdep_sock_is_held(sk));
1265 	if (inet_opt && inet_opt->opt.srr)
1266 		daddr = inet_opt->opt.faddr;
1267 
1268 	/* Query new route. */
1269 	fl4 = &inet->cork.fl.u.ip4;
1270 	rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1271 			      sk->sk_protocol, inet->inet_sport,
1272 			      inet->inet_dport, sk);
1273 	if (IS_ERR(rt))
1274 		return PTR_ERR(rt);
1275 
1276 	new_saddr = fl4->saddr;
1277 
1278 	if (new_saddr == old_saddr) {
1279 		sk_setup_caps(sk, &rt->dst);
1280 		return 0;
1281 	}
1282 
1283 	err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1284 	if (err) {
1285 		ip_rt_put(rt);
1286 		return err;
1287 	}
1288 
1289 	sk_setup_caps(sk, &rt->dst);
1290 
1291 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1292 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1293 			__func__, &old_saddr, &new_saddr);
1294 	}
1295 
1296 	/*
1297 	 * XXX The only one ugly spot where we need to
1298 	 * XXX really change the sockets identity after
1299 	 * XXX it has entered the hashes. -DaveM
1300 	 *
1301 	 * Besides that, it does not check for connection
1302 	 * uniqueness. Wait for troubles.
1303 	 */
1304 	return __sk_prot_rehash(sk);
1305 }
1306 
1307 int inet_sk_rebuild_header(struct sock *sk)
1308 {
1309 	struct inet_sock *inet = inet_sk(sk);
1310 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1311 	__be32 daddr;
1312 	struct ip_options_rcu *inet_opt;
1313 	struct flowi4 *fl4;
1314 	int err;
1315 
1316 	/* Route is OK, nothing to do. */
1317 	if (rt)
1318 		return 0;
1319 
1320 	/* Reroute. */
1321 	rcu_read_lock();
1322 	inet_opt = rcu_dereference(inet->inet_opt);
1323 	daddr = inet->inet_daddr;
1324 	if (inet_opt && inet_opt->opt.srr)
1325 		daddr = inet_opt->opt.faddr;
1326 	rcu_read_unlock();
1327 	fl4 = &inet->cork.fl.u.ip4;
1328 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1329 				   inet->inet_dport, inet->inet_sport,
1330 				   sk->sk_protocol, ip_sock_rt_tos(sk),
1331 				   sk->sk_bound_dev_if);
1332 	if (!IS_ERR(rt)) {
1333 		err = 0;
1334 		sk_setup_caps(sk, &rt->dst);
1335 	} else {
1336 		err = PTR_ERR(rt);
1337 
1338 		/* Routing failed... */
1339 		sk->sk_route_caps = 0;
1340 		/*
1341 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1342 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1343 		 */
1344 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1345 		    sk->sk_state != TCP_SYN_SENT ||
1346 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1347 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1348 			WRITE_ONCE(sk->sk_err_soft, -err);
1349 	}
1350 
1351 	return err;
1352 }
1353 EXPORT_SYMBOL(inet_sk_rebuild_header);
1354 
1355 void inet_sk_set_state(struct sock *sk, int state)
1356 {
1357 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1358 	sk->sk_state = state;
1359 }
1360 EXPORT_SYMBOL(inet_sk_set_state);
1361 
1362 void inet_sk_state_store(struct sock *sk, int newstate)
1363 {
1364 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1365 	smp_store_release(&sk->sk_state, newstate);
1366 }
1367 
1368 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1369 				 netdev_features_t features)
1370 {
1371 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1372 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1373 	const struct net_offload *ops;
1374 	unsigned int offset = 0;
1375 	struct iphdr *iph;
1376 	int proto, tot_len;
1377 	int nhoff;
1378 	int ihl;
1379 	int id;
1380 
1381 	skb_reset_network_header(skb);
1382 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1383 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1384 		goto out;
1385 
1386 	iph = ip_hdr(skb);
1387 	ihl = iph->ihl * 4;
1388 	if (ihl < sizeof(*iph))
1389 		goto out;
1390 
1391 	id = ntohs(iph->id);
1392 	proto = iph->protocol;
1393 
1394 	/* Warning: after this point, iph might be no longer valid */
1395 	if (unlikely(!pskb_may_pull(skb, ihl)))
1396 		goto out;
1397 	__skb_pull(skb, ihl);
1398 
1399 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1400 	if (encap)
1401 		features &= skb->dev->hw_enc_features;
1402 	SKB_GSO_CB(skb)->encap_level += ihl;
1403 
1404 	skb_reset_transport_header(skb);
1405 
1406 	segs = ERR_PTR(-EPROTONOSUPPORT);
1407 
1408 	if (!skb->encapsulation || encap) {
1409 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1410 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1411 
1412 		/* fixed ID is invalid if DF bit is not set */
1413 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1414 			goto out;
1415 	}
1416 
1417 	ops = rcu_dereference(inet_offloads[proto]);
1418 	if (likely(ops && ops->callbacks.gso_segment)) {
1419 		segs = ops->callbacks.gso_segment(skb, features);
1420 		if (!segs)
1421 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1422 	}
1423 
1424 	if (IS_ERR_OR_NULL(segs))
1425 		goto out;
1426 
1427 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1428 
1429 	skb = segs;
1430 	do {
1431 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1432 		if (udpfrag) {
1433 			iph->frag_off = htons(offset >> 3);
1434 			if (skb->next)
1435 				iph->frag_off |= htons(IP_MF);
1436 			offset += skb->len - nhoff - ihl;
1437 			tot_len = skb->len - nhoff;
1438 		} else if (skb_is_gso(skb)) {
1439 			if (!fixedid) {
1440 				iph->id = htons(id);
1441 				id += skb_shinfo(skb)->gso_segs;
1442 			}
1443 
1444 			if (gso_partial)
1445 				tot_len = skb_shinfo(skb)->gso_size +
1446 					  SKB_GSO_CB(skb)->data_offset +
1447 					  skb->head - (unsigned char *)iph;
1448 			else
1449 				tot_len = skb->len - nhoff;
1450 		} else {
1451 			if (!fixedid)
1452 				iph->id = htons(id++);
1453 			tot_len = skb->len - nhoff;
1454 		}
1455 		iph->tot_len = htons(tot_len);
1456 		ip_send_check(iph);
1457 		if (encap)
1458 			skb_reset_inner_headers(skb);
1459 		skb->network_header = (u8 *)iph - skb->head;
1460 		skb_reset_mac_len(skb);
1461 	} while ((skb = skb->next));
1462 
1463 out:
1464 	return segs;
1465 }
1466 
1467 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1468 					netdev_features_t features)
1469 {
1470 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1471 		return ERR_PTR(-EINVAL);
1472 
1473 	return inet_gso_segment(skb, features);
1474 }
1475 
1476 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1477 {
1478 	const struct net_offload *ops;
1479 	struct sk_buff *pp = NULL;
1480 	const struct iphdr *iph;
1481 	struct sk_buff *p;
1482 	unsigned int hlen;
1483 	unsigned int off;
1484 	unsigned int id;
1485 	int flush = 1;
1486 	int proto;
1487 
1488 	off = skb_gro_offset(skb);
1489 	hlen = off + sizeof(*iph);
1490 	iph = skb_gro_header(skb, hlen, off);
1491 	if (unlikely(!iph))
1492 		goto out;
1493 
1494 	proto = iph->protocol;
1495 
1496 	ops = rcu_dereference(inet_offloads[proto]);
1497 	if (!ops || !ops->callbacks.gro_receive)
1498 		goto out;
1499 
1500 	if (*(u8 *)iph != 0x45)
1501 		goto out;
1502 
1503 	if (ip_is_fragment(iph))
1504 		goto out;
1505 
1506 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1507 		goto out;
1508 
1509 	NAPI_GRO_CB(skb)->proto = proto;
1510 	id = ntohl(*(__be32 *)&iph->id);
1511 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1512 	id >>= 16;
1513 
1514 	list_for_each_entry(p, head, list) {
1515 		struct iphdr *iph2;
1516 		u16 flush_id;
1517 
1518 		if (!NAPI_GRO_CB(p)->same_flow)
1519 			continue;
1520 
1521 		iph2 = (struct iphdr *)(p->data + off);
1522 		/* The above works because, with the exception of the top
1523 		 * (inner most) layer, we only aggregate pkts with the same
1524 		 * hdr length so all the hdrs we'll need to verify will start
1525 		 * at the same offset.
1526 		 */
1527 		if ((iph->protocol ^ iph2->protocol) |
1528 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1529 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1530 			NAPI_GRO_CB(p)->same_flow = 0;
1531 			continue;
1532 		}
1533 
1534 		/* All fields must match except length and checksum. */
1535 		NAPI_GRO_CB(p)->flush |=
1536 			(iph->ttl ^ iph2->ttl) |
1537 			(iph->tos ^ iph2->tos) |
1538 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1539 
1540 		NAPI_GRO_CB(p)->flush |= flush;
1541 
1542 		/* We need to store of the IP ID check to be included later
1543 		 * when we can verify that this packet does in fact belong
1544 		 * to a given flow.
1545 		 */
1546 		flush_id = (u16)(id - ntohs(iph2->id));
1547 
1548 		/* This bit of code makes it much easier for us to identify
1549 		 * the cases where we are doing atomic vs non-atomic IP ID
1550 		 * checks.  Specifically an atomic check can return IP ID
1551 		 * values 0 - 0xFFFF, while a non-atomic check can only
1552 		 * return 0 or 0xFFFF.
1553 		 */
1554 		if (!NAPI_GRO_CB(p)->is_atomic ||
1555 		    !(iph->frag_off & htons(IP_DF))) {
1556 			flush_id ^= NAPI_GRO_CB(p)->count;
1557 			flush_id = flush_id ? 0xFFFF : 0;
1558 		}
1559 
1560 		/* If the previous IP ID value was based on an atomic
1561 		 * datagram we can overwrite the value and ignore it.
1562 		 */
1563 		if (NAPI_GRO_CB(skb)->is_atomic)
1564 			NAPI_GRO_CB(p)->flush_id = flush_id;
1565 		else
1566 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1567 	}
1568 
1569 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1570 	NAPI_GRO_CB(skb)->flush |= flush;
1571 	skb_set_network_header(skb, off);
1572 	/* The above will be needed by the transport layer if there is one
1573 	 * immediately following this IP hdr.
1574 	 */
1575 
1576 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1577 	 * as we already checked checksum over ipv4 header was 0
1578 	 */
1579 	skb_gro_pull(skb, sizeof(*iph));
1580 	skb_set_transport_header(skb, skb_gro_offset(skb));
1581 
1582 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1583 				       ops->callbacks.gro_receive, head, skb);
1584 
1585 out:
1586 	skb_gro_flush_final(skb, pp, flush);
1587 
1588 	return pp;
1589 }
1590 
1591 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1592 					struct sk_buff *skb)
1593 {
1594 	if (NAPI_GRO_CB(skb)->encap_mark) {
1595 		NAPI_GRO_CB(skb)->flush = 1;
1596 		return NULL;
1597 	}
1598 
1599 	NAPI_GRO_CB(skb)->encap_mark = 1;
1600 
1601 	return inet_gro_receive(head, skb);
1602 }
1603 
1604 #define SECONDS_PER_DAY	86400
1605 
1606 /* inet_current_timestamp - Return IP network timestamp
1607  *
1608  * Return milliseconds since midnight in network byte order.
1609  */
1610 __be32 inet_current_timestamp(void)
1611 {
1612 	u32 secs;
1613 	u32 msecs;
1614 	struct timespec64 ts;
1615 
1616 	ktime_get_real_ts64(&ts);
1617 
1618 	/* Get secs since midnight. */
1619 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1620 	/* Convert to msecs. */
1621 	msecs = secs * MSEC_PER_SEC;
1622 	/* Convert nsec to msec. */
1623 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1624 
1625 	/* Convert to network byte order. */
1626 	return htonl(msecs);
1627 }
1628 EXPORT_SYMBOL(inet_current_timestamp);
1629 
1630 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1631 {
1632 	unsigned int family = READ_ONCE(sk->sk_family);
1633 
1634 	if (family == AF_INET)
1635 		return ip_recv_error(sk, msg, len, addr_len);
1636 #if IS_ENABLED(CONFIG_IPV6)
1637 	if (family == AF_INET6)
1638 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1639 #endif
1640 	return -EINVAL;
1641 }
1642 EXPORT_SYMBOL(inet_recv_error);
1643 
1644 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1645 {
1646 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1647 	const struct net_offload *ops;
1648 	__be16 totlen = iph->tot_len;
1649 	int proto = iph->protocol;
1650 	int err = -ENOSYS;
1651 
1652 	if (skb->encapsulation) {
1653 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1654 		skb_set_inner_network_header(skb, nhoff);
1655 	}
1656 
1657 	iph_set_totlen(iph, skb->len - nhoff);
1658 	csum_replace2(&iph->check, totlen, iph->tot_len);
1659 
1660 	ops = rcu_dereference(inet_offloads[proto]);
1661 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1662 		goto out;
1663 
1664 	/* Only need to add sizeof(*iph) to get to the next hdr below
1665 	 * because any hdr with option will have been flushed in
1666 	 * inet_gro_receive().
1667 	 */
1668 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1669 			      tcp4_gro_complete, udp4_gro_complete,
1670 			      skb, nhoff + sizeof(*iph));
1671 
1672 out:
1673 	return err;
1674 }
1675 
1676 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1677 {
1678 	skb->encapsulation = 1;
1679 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1680 	return inet_gro_complete(skb, nhoff);
1681 }
1682 
1683 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1684 			 unsigned short type, unsigned char protocol,
1685 			 struct net *net)
1686 {
1687 	struct socket *sock;
1688 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1689 
1690 	if (rc == 0) {
1691 		*sk = sock->sk;
1692 		(*sk)->sk_allocation = GFP_ATOMIC;
1693 		(*sk)->sk_use_task_frag = false;
1694 		/*
1695 		 * Unhash it so that IP input processing does not even see it,
1696 		 * we do not wish this socket to see incoming packets.
1697 		 */
1698 		(*sk)->sk_prot->unhash(*sk);
1699 	}
1700 	return rc;
1701 }
1702 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1703 
1704 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1705 {
1706 	unsigned long res = 0;
1707 	int i;
1708 
1709 	for_each_possible_cpu(i)
1710 		res += snmp_get_cpu_field(mib, i, offt);
1711 	return res;
1712 }
1713 EXPORT_SYMBOL_GPL(snmp_fold_field);
1714 
1715 #if BITS_PER_LONG==32
1716 
1717 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1718 			 size_t syncp_offset)
1719 {
1720 	void *bhptr;
1721 	struct u64_stats_sync *syncp;
1722 	u64 v;
1723 	unsigned int start;
1724 
1725 	bhptr = per_cpu_ptr(mib, cpu);
1726 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1727 	do {
1728 		start = u64_stats_fetch_begin(syncp);
1729 		v = *(((u64 *)bhptr) + offt);
1730 	} while (u64_stats_fetch_retry(syncp, start));
1731 
1732 	return v;
1733 }
1734 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1735 
1736 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1737 {
1738 	u64 res = 0;
1739 	int cpu;
1740 
1741 	for_each_possible_cpu(cpu) {
1742 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1743 	}
1744 	return res;
1745 }
1746 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1747 #endif
1748 
1749 #ifdef CONFIG_IP_MULTICAST
1750 static const struct net_protocol igmp_protocol = {
1751 	.handler =	igmp_rcv,
1752 };
1753 #endif
1754 
1755 static const struct net_protocol icmp_protocol = {
1756 	.handler =	icmp_rcv,
1757 	.err_handler =	icmp_err,
1758 	.no_policy =	1,
1759 };
1760 
1761 static __net_init int ipv4_mib_init_net(struct net *net)
1762 {
1763 	int i;
1764 
1765 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1766 	if (!net->mib.tcp_statistics)
1767 		goto err_tcp_mib;
1768 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1769 	if (!net->mib.ip_statistics)
1770 		goto err_ip_mib;
1771 
1772 	for_each_possible_cpu(i) {
1773 		struct ipstats_mib *af_inet_stats;
1774 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1775 		u64_stats_init(&af_inet_stats->syncp);
1776 	}
1777 
1778 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1779 	if (!net->mib.net_statistics)
1780 		goto err_net_mib;
1781 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1782 	if (!net->mib.udp_statistics)
1783 		goto err_udp_mib;
1784 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1785 	if (!net->mib.udplite_statistics)
1786 		goto err_udplite_mib;
1787 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1788 	if (!net->mib.icmp_statistics)
1789 		goto err_icmp_mib;
1790 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1791 					      GFP_KERNEL);
1792 	if (!net->mib.icmpmsg_statistics)
1793 		goto err_icmpmsg_mib;
1794 
1795 	tcp_mib_init(net);
1796 	return 0;
1797 
1798 err_icmpmsg_mib:
1799 	free_percpu(net->mib.icmp_statistics);
1800 err_icmp_mib:
1801 	free_percpu(net->mib.udplite_statistics);
1802 err_udplite_mib:
1803 	free_percpu(net->mib.udp_statistics);
1804 err_udp_mib:
1805 	free_percpu(net->mib.net_statistics);
1806 err_net_mib:
1807 	free_percpu(net->mib.ip_statistics);
1808 err_ip_mib:
1809 	free_percpu(net->mib.tcp_statistics);
1810 err_tcp_mib:
1811 	return -ENOMEM;
1812 }
1813 
1814 static __net_exit void ipv4_mib_exit_net(struct net *net)
1815 {
1816 	kfree(net->mib.icmpmsg_statistics);
1817 	free_percpu(net->mib.icmp_statistics);
1818 	free_percpu(net->mib.udplite_statistics);
1819 	free_percpu(net->mib.udp_statistics);
1820 	free_percpu(net->mib.net_statistics);
1821 	free_percpu(net->mib.ip_statistics);
1822 	free_percpu(net->mib.tcp_statistics);
1823 #ifdef CONFIG_MPTCP
1824 	/* allocated on demand, see mptcp_init_sock() */
1825 	free_percpu(net->mib.mptcp_statistics);
1826 #endif
1827 }
1828 
1829 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1830 	.init = ipv4_mib_init_net,
1831 	.exit = ipv4_mib_exit_net,
1832 };
1833 
1834 static int __init init_ipv4_mibs(void)
1835 {
1836 	return register_pernet_subsys(&ipv4_mib_ops);
1837 }
1838 
1839 static __net_init int inet_init_net(struct net *net)
1840 {
1841 	/*
1842 	 * Set defaults for local port range
1843 	 */
1844 	net->ipv4.ip_local_ports.range = 60999u << 16 | 32768u;
1845 
1846 	seqlock_init(&net->ipv4.ping_group_range.lock);
1847 	/*
1848 	 * Sane defaults - nobody may create ping sockets.
1849 	 * Boot scripts should set this to distro-specific group.
1850 	 */
1851 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1852 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1853 
1854 	/* Default values for sysctl-controlled parameters.
1855 	 * We set them here, in case sysctl is not compiled.
1856 	 */
1857 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1858 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1859 	net->ipv4.sysctl_ip_dynaddr = 0;
1860 	net->ipv4.sysctl_ip_early_demux = 1;
1861 	net->ipv4.sysctl_udp_early_demux = 1;
1862 	net->ipv4.sysctl_tcp_early_demux = 1;
1863 	net->ipv4.sysctl_nexthop_compat_mode = 1;
1864 #ifdef CONFIG_SYSCTL
1865 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1866 #endif
1867 
1868 	/* Some igmp sysctl, whose values are always used */
1869 	net->ipv4.sysctl_igmp_max_memberships = 20;
1870 	net->ipv4.sysctl_igmp_max_msf = 10;
1871 	/* IGMP reports for link-local multicast groups are enabled by default */
1872 	net->ipv4.sysctl_igmp_llm_reports = 1;
1873 	net->ipv4.sysctl_igmp_qrv = 2;
1874 
1875 	net->ipv4.sysctl_fib_notify_on_flag_change = 0;
1876 
1877 	return 0;
1878 }
1879 
1880 static __net_initdata struct pernet_operations af_inet_ops = {
1881 	.init = inet_init_net,
1882 };
1883 
1884 static int __init init_inet_pernet_ops(void)
1885 {
1886 	return register_pernet_subsys(&af_inet_ops);
1887 }
1888 
1889 static int ipv4_proc_init(void);
1890 
1891 /*
1892  *	IP protocol layer initialiser
1893  */
1894 
1895 
1896 static const struct net_offload ipip_offload = {
1897 	.callbacks = {
1898 		.gso_segment	= ipip_gso_segment,
1899 		.gro_receive	= ipip_gro_receive,
1900 		.gro_complete	= ipip_gro_complete,
1901 	},
1902 };
1903 
1904 static int __init ipip_offload_init(void)
1905 {
1906 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1907 }
1908 
1909 static int __init ipv4_offload_init(void)
1910 {
1911 	/*
1912 	 * Add offloads
1913 	 */
1914 	if (udpv4_offload_init() < 0)
1915 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1916 	if (tcpv4_offload_init() < 0)
1917 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1918 	if (ipip_offload_init() < 0)
1919 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1920 
1921 	net_hotdata.ip_packet_offload = (struct packet_offload) {
1922 		.type = cpu_to_be16(ETH_P_IP),
1923 		.callbacks = {
1924 			.gso_segment = inet_gso_segment,
1925 			.gro_receive = inet_gro_receive,
1926 			.gro_complete = inet_gro_complete,
1927 		},
1928 	};
1929 	dev_add_offload(&net_hotdata.ip_packet_offload);
1930 	return 0;
1931 }
1932 
1933 fs_initcall(ipv4_offload_init);
1934 
1935 static struct packet_type ip_packet_type __read_mostly = {
1936 	.type = cpu_to_be16(ETH_P_IP),
1937 	.func = ip_rcv,
1938 	.list_func = ip_list_rcv,
1939 };
1940 
1941 static int __init inet_init(void)
1942 {
1943 	struct inet_protosw *q;
1944 	struct list_head *r;
1945 	int rc;
1946 
1947 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1948 
1949 	raw_hashinfo_init(&raw_v4_hashinfo);
1950 
1951 	rc = proto_register(&tcp_prot, 1);
1952 	if (rc)
1953 		goto out;
1954 
1955 	rc = proto_register(&udp_prot, 1);
1956 	if (rc)
1957 		goto out_unregister_tcp_proto;
1958 
1959 	rc = proto_register(&raw_prot, 1);
1960 	if (rc)
1961 		goto out_unregister_udp_proto;
1962 
1963 	rc = proto_register(&ping_prot, 1);
1964 	if (rc)
1965 		goto out_unregister_raw_proto;
1966 
1967 	/*
1968 	 *	Tell SOCKET that we are alive...
1969 	 */
1970 
1971 	(void)sock_register(&inet_family_ops);
1972 
1973 #ifdef CONFIG_SYSCTL
1974 	ip_static_sysctl_init();
1975 #endif
1976 
1977 	/*
1978 	 *	Add all the base protocols.
1979 	 */
1980 
1981 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1982 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1983 
1984 	net_hotdata.udp_protocol = (struct net_protocol) {
1985 		.handler =	udp_rcv,
1986 		.err_handler =	udp_err,
1987 		.no_policy =	1,
1988 	};
1989 	if (inet_add_protocol(&net_hotdata.udp_protocol, IPPROTO_UDP) < 0)
1990 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1991 
1992 	net_hotdata.tcp_protocol = (struct net_protocol) {
1993 		.handler	=	tcp_v4_rcv,
1994 		.err_handler	=	tcp_v4_err,
1995 		.no_policy	=	1,
1996 		.icmp_strict_tag_validation = 1,
1997 	};
1998 	if (inet_add_protocol(&net_hotdata.tcp_protocol, IPPROTO_TCP) < 0)
1999 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
2000 #ifdef CONFIG_IP_MULTICAST
2001 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
2002 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
2003 #endif
2004 
2005 	/* Register the socket-side information for inet_create. */
2006 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
2007 		INIT_LIST_HEAD(r);
2008 
2009 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
2010 		inet_register_protosw(q);
2011 
2012 	/*
2013 	 *	Set the ARP module up
2014 	 */
2015 
2016 	arp_init();
2017 
2018 	/*
2019 	 *	Set the IP module up
2020 	 */
2021 
2022 	ip_init();
2023 
2024 	/* Initialise per-cpu ipv4 mibs */
2025 	if (init_ipv4_mibs())
2026 		panic("%s: Cannot init ipv4 mibs\n", __func__);
2027 
2028 	/* Setup TCP slab cache for open requests. */
2029 	tcp_init();
2030 
2031 	/* Setup UDP memory threshold */
2032 	udp_init();
2033 
2034 	/* Add UDP-Lite (RFC 3828) */
2035 	udplite4_register();
2036 
2037 	raw_init();
2038 
2039 	ping_init();
2040 
2041 	/*
2042 	 *	Set the ICMP layer up
2043 	 */
2044 
2045 	if (icmp_init() < 0)
2046 		panic("Failed to create the ICMP control socket.\n");
2047 
2048 	/*
2049 	 *	Initialise the multicast router
2050 	 */
2051 #if defined(CONFIG_IP_MROUTE)
2052 	if (ip_mr_init())
2053 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2054 #endif
2055 
2056 	if (init_inet_pernet_ops())
2057 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2058 
2059 	ipv4_proc_init();
2060 
2061 	ipfrag_init();
2062 
2063 	dev_add_pack(&ip_packet_type);
2064 
2065 	ip_tunnel_core_init();
2066 
2067 	rc = 0;
2068 out:
2069 	return rc;
2070 out_unregister_raw_proto:
2071 	proto_unregister(&raw_prot);
2072 out_unregister_udp_proto:
2073 	proto_unregister(&udp_prot);
2074 out_unregister_tcp_proto:
2075 	proto_unregister(&tcp_prot);
2076 	goto out;
2077 }
2078 
2079 fs_initcall(inet_init);
2080 
2081 /* ------------------------------------------------------------------------ */
2082 
2083 #ifdef CONFIG_PROC_FS
2084 static int __init ipv4_proc_init(void)
2085 {
2086 	int rc = 0;
2087 
2088 	if (raw_proc_init())
2089 		goto out_raw;
2090 	if (tcp4_proc_init())
2091 		goto out_tcp;
2092 	if (udp4_proc_init())
2093 		goto out_udp;
2094 	if (ping_proc_init())
2095 		goto out_ping;
2096 	if (ip_misc_proc_init())
2097 		goto out_misc;
2098 out:
2099 	return rc;
2100 out_misc:
2101 	ping_proc_exit();
2102 out_ping:
2103 	udp4_proc_exit();
2104 out_udp:
2105 	tcp4_proc_exit();
2106 out_tcp:
2107 	raw_proc_exit();
2108 out_raw:
2109 	rc = -ENOMEM;
2110 	goto out;
2111 }
2112 
2113 #else /* CONFIG_PROC_FS */
2114 static int __init ipv4_proc_init(void)
2115 {
2116 	return 0;
2117 }
2118 #endif /* CONFIG_PROC_FS */
2119