xref: /openbmc/linux/net/ipv4/af_inet.c (revision 168e7e599860654876c2a1102a82610285c02f02)
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,
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 
801 	sin->sin_family = AF_INET;
802 	lock_sock(sk);
803 	if (peer) {
804 		if (!inet->inet_dport ||
805 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
806 		     peer == 1)) {
807 			release_sock(sk);
808 			return -ENOTCONN;
809 		}
810 		sin->sin_port = inet->inet_dport;
811 		sin->sin_addr.s_addr = inet->inet_daddr;
812 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
813 				       CGROUP_INET4_GETPEERNAME);
814 	} else {
815 		__be32 addr = inet->inet_rcv_saddr;
816 		if (!addr)
817 			addr = inet->inet_saddr;
818 		sin->sin_port = inet->inet_sport;
819 		sin->sin_addr.s_addr = addr;
820 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
821 				       CGROUP_INET4_GETSOCKNAME);
822 	}
823 	release_sock(sk);
824 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
825 	return sizeof(*sin);
826 }
827 EXPORT_SYMBOL(inet_getname);
828 
829 int inet_send_prepare(struct sock *sk)
830 {
831 	sock_rps_record_flow(sk);
832 
833 	/* We may need to bind the socket. */
834 	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
835 	    inet_autobind(sk))
836 		return -EAGAIN;
837 
838 	return 0;
839 }
840 EXPORT_SYMBOL_GPL(inet_send_prepare);
841 
842 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
843 {
844 	struct sock *sk = sock->sk;
845 
846 	if (unlikely(inet_send_prepare(sk)))
847 		return -EAGAIN;
848 
849 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
850 			       sk, msg, size);
851 }
852 EXPORT_SYMBOL(inet_sendmsg);
853 
854 void inet_splice_eof(struct socket *sock)
855 {
856 	const struct proto *prot;
857 	struct sock *sk = sock->sk;
858 
859 	if (unlikely(inet_send_prepare(sk)))
860 		return;
861 
862 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
863 	prot = READ_ONCE(sk->sk_prot);
864 	if (prot->splice_eof)
865 		prot->splice_eof(sock);
866 }
867 EXPORT_SYMBOL_GPL(inet_splice_eof);
868 
869 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
870 					  size_t, int, int *));
871 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
872 		 int flags)
873 {
874 	struct sock *sk = sock->sk;
875 	int addr_len = 0;
876 	int err;
877 
878 	if (likely(!(flags & MSG_ERRQUEUE)))
879 		sock_rps_record_flow(sk);
880 
881 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
882 			      sk, msg, size, flags, &addr_len);
883 	if (err >= 0)
884 		msg->msg_namelen = addr_len;
885 	return err;
886 }
887 EXPORT_SYMBOL(inet_recvmsg);
888 
889 int inet_shutdown(struct socket *sock, int how)
890 {
891 	struct sock *sk = sock->sk;
892 	int err = 0;
893 
894 	/* This should really check to make sure
895 	 * the socket is a TCP socket. (WHY AC...)
896 	 */
897 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
898 		       1->2 bit 2 snds.
899 		       2->3 */
900 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
901 		return -EINVAL;
902 
903 	lock_sock(sk);
904 	if (sock->state == SS_CONNECTING) {
905 		if ((1 << sk->sk_state) &
906 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
907 			sock->state = SS_DISCONNECTING;
908 		else
909 			sock->state = SS_CONNECTED;
910 	}
911 
912 	switch (sk->sk_state) {
913 	case TCP_CLOSE:
914 		err = -ENOTCONN;
915 		/* Hack to wake up other listeners, who can poll for
916 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
917 		fallthrough;
918 	default:
919 		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
920 		if (sk->sk_prot->shutdown)
921 			sk->sk_prot->shutdown(sk, how);
922 		break;
923 
924 	/* Remaining two branches are temporary solution for missing
925 	 * close() in multithreaded environment. It is _not_ a good idea,
926 	 * but we have no choice until close() is repaired at VFS level.
927 	 */
928 	case TCP_LISTEN:
929 		if (!(how & RCV_SHUTDOWN))
930 			break;
931 		fallthrough;
932 	case TCP_SYN_SENT:
933 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
934 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
935 		break;
936 	}
937 
938 	/* Wake up anyone sleeping in poll. */
939 	sk->sk_state_change(sk);
940 	release_sock(sk);
941 	return err;
942 }
943 EXPORT_SYMBOL(inet_shutdown);
944 
945 /*
946  *	ioctl() calls you can issue on an INET socket. Most of these are
947  *	device configuration and stuff and very rarely used. Some ioctls
948  *	pass on to the socket itself.
949  *
950  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
951  *	loads the devconfigure module does its configuring and unloads it.
952  *	There's a good 20K of config code hanging around the kernel.
953  */
954 
955 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
956 {
957 	struct sock *sk = sock->sk;
958 	int err = 0;
959 	struct net *net = sock_net(sk);
960 	void __user *p = (void __user *)arg;
961 	struct ifreq ifr;
962 	struct rtentry rt;
963 
964 	switch (cmd) {
965 	case SIOCADDRT:
966 	case SIOCDELRT:
967 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
968 			return -EFAULT;
969 		err = ip_rt_ioctl(net, cmd, &rt);
970 		break;
971 	case SIOCRTMSG:
972 		err = -EINVAL;
973 		break;
974 	case SIOCDARP:
975 	case SIOCGARP:
976 	case SIOCSARP:
977 		err = arp_ioctl(net, cmd, (void __user *)arg);
978 		break;
979 	case SIOCGIFADDR:
980 	case SIOCGIFBRDADDR:
981 	case SIOCGIFNETMASK:
982 	case SIOCGIFDSTADDR:
983 	case SIOCGIFPFLAGS:
984 		if (get_user_ifreq(&ifr, NULL, p))
985 			return -EFAULT;
986 		err = devinet_ioctl(net, cmd, &ifr);
987 		if (!err && put_user_ifreq(&ifr, p))
988 			err = -EFAULT;
989 		break;
990 
991 	case SIOCSIFADDR:
992 	case SIOCSIFBRDADDR:
993 	case SIOCSIFNETMASK:
994 	case SIOCSIFDSTADDR:
995 	case SIOCSIFPFLAGS:
996 	case SIOCSIFFLAGS:
997 		if (get_user_ifreq(&ifr, NULL, p))
998 			return -EFAULT;
999 		err = devinet_ioctl(net, cmd, &ifr);
1000 		break;
1001 	default:
1002 		if (sk->sk_prot->ioctl)
1003 			err = sk_ioctl(sk, cmd, (void __user *)arg);
1004 		else
1005 			err = -ENOIOCTLCMD;
1006 		break;
1007 	}
1008 	return err;
1009 }
1010 EXPORT_SYMBOL(inet_ioctl);
1011 
1012 #ifdef CONFIG_COMPAT
1013 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1014 		struct compat_rtentry __user *ur)
1015 {
1016 	compat_uptr_t rtdev;
1017 	struct rtentry rt;
1018 
1019 	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1020 			3 * sizeof(struct sockaddr)) ||
1021 	    get_user(rt.rt_flags, &ur->rt_flags) ||
1022 	    get_user(rt.rt_metric, &ur->rt_metric) ||
1023 	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1024 	    get_user(rt.rt_window, &ur->rt_window) ||
1025 	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1026 	    get_user(rtdev, &ur->rt_dev))
1027 		return -EFAULT;
1028 
1029 	rt.rt_dev = compat_ptr(rtdev);
1030 	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1031 }
1032 
1033 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1034 {
1035 	void __user *argp = compat_ptr(arg);
1036 	struct sock *sk = sock->sk;
1037 
1038 	switch (cmd) {
1039 	case SIOCADDRT:
1040 	case SIOCDELRT:
1041 		return inet_compat_routing_ioctl(sk, cmd, argp);
1042 	default:
1043 		if (!sk->sk_prot->compat_ioctl)
1044 			return -ENOIOCTLCMD;
1045 		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1046 	}
1047 }
1048 #endif /* CONFIG_COMPAT */
1049 
1050 const struct proto_ops inet_stream_ops = {
1051 	.family		   = PF_INET,
1052 	.owner		   = THIS_MODULE,
1053 	.release	   = inet_release,
1054 	.bind		   = inet_bind,
1055 	.connect	   = inet_stream_connect,
1056 	.socketpair	   = sock_no_socketpair,
1057 	.accept		   = inet_accept,
1058 	.getname	   = inet_getname,
1059 	.poll		   = tcp_poll,
1060 	.ioctl		   = inet_ioctl,
1061 	.gettstamp	   = sock_gettstamp,
1062 	.listen		   = inet_listen,
1063 	.shutdown	   = inet_shutdown,
1064 	.setsockopt	   = sock_common_setsockopt,
1065 	.getsockopt	   = sock_common_getsockopt,
1066 	.sendmsg	   = inet_sendmsg,
1067 	.recvmsg	   = inet_recvmsg,
1068 #ifdef CONFIG_MMU
1069 	.mmap		   = tcp_mmap,
1070 #endif
1071 	.splice_eof	   = inet_splice_eof,
1072 	.splice_read	   = tcp_splice_read,
1073 	.read_sock	   = tcp_read_sock,
1074 	.read_skb	   = tcp_read_skb,
1075 	.sendmsg_locked    = tcp_sendmsg_locked,
1076 	.peek_len	   = tcp_peek_len,
1077 #ifdef CONFIG_COMPAT
1078 	.compat_ioctl	   = inet_compat_ioctl,
1079 #endif
1080 	.set_rcvlowat	   = tcp_set_rcvlowat,
1081 };
1082 EXPORT_SYMBOL(inet_stream_ops);
1083 
1084 const struct proto_ops inet_dgram_ops = {
1085 	.family		   = PF_INET,
1086 	.owner		   = THIS_MODULE,
1087 	.release	   = inet_release,
1088 	.bind		   = inet_bind,
1089 	.connect	   = inet_dgram_connect,
1090 	.socketpair	   = sock_no_socketpair,
1091 	.accept		   = sock_no_accept,
1092 	.getname	   = inet_getname,
1093 	.poll		   = udp_poll,
1094 	.ioctl		   = inet_ioctl,
1095 	.gettstamp	   = sock_gettstamp,
1096 	.listen		   = sock_no_listen,
1097 	.shutdown	   = inet_shutdown,
1098 	.setsockopt	   = sock_common_setsockopt,
1099 	.getsockopt	   = sock_common_getsockopt,
1100 	.sendmsg	   = inet_sendmsg,
1101 	.read_skb	   = udp_read_skb,
1102 	.recvmsg	   = inet_recvmsg,
1103 	.mmap		   = sock_no_mmap,
1104 	.splice_eof	   = inet_splice_eof,
1105 	.set_peek_off	   = sk_set_peek_off,
1106 #ifdef CONFIG_COMPAT
1107 	.compat_ioctl	   = inet_compat_ioctl,
1108 #endif
1109 };
1110 EXPORT_SYMBOL(inet_dgram_ops);
1111 
1112 /*
1113  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1114  * udp_poll
1115  */
1116 static const struct proto_ops inet_sockraw_ops = {
1117 	.family		   = PF_INET,
1118 	.owner		   = THIS_MODULE,
1119 	.release	   = inet_release,
1120 	.bind		   = inet_bind,
1121 	.connect	   = inet_dgram_connect,
1122 	.socketpair	   = sock_no_socketpair,
1123 	.accept		   = sock_no_accept,
1124 	.getname	   = inet_getname,
1125 	.poll		   = datagram_poll,
1126 	.ioctl		   = inet_ioctl,
1127 	.gettstamp	   = sock_gettstamp,
1128 	.listen		   = sock_no_listen,
1129 	.shutdown	   = inet_shutdown,
1130 	.setsockopt	   = sock_common_setsockopt,
1131 	.getsockopt	   = sock_common_getsockopt,
1132 	.sendmsg	   = inet_sendmsg,
1133 	.recvmsg	   = inet_recvmsg,
1134 	.mmap		   = sock_no_mmap,
1135 	.splice_eof	   = inet_splice_eof,
1136 #ifdef CONFIG_COMPAT
1137 	.compat_ioctl	   = inet_compat_ioctl,
1138 #endif
1139 };
1140 
1141 static const struct net_proto_family inet_family_ops = {
1142 	.family = PF_INET,
1143 	.create = inet_create,
1144 	.owner	= THIS_MODULE,
1145 };
1146 
1147 /* Upon startup we insert all the elements in inetsw_array[] into
1148  * the linked list inetsw.
1149  */
1150 static struct inet_protosw inetsw_array[] =
1151 {
1152 	{
1153 		.type =       SOCK_STREAM,
1154 		.protocol =   IPPROTO_TCP,
1155 		.prot =       &tcp_prot,
1156 		.ops =        &inet_stream_ops,
1157 		.flags =      INET_PROTOSW_PERMANENT |
1158 			      INET_PROTOSW_ICSK,
1159 	},
1160 
1161 	{
1162 		.type =       SOCK_DGRAM,
1163 		.protocol =   IPPROTO_UDP,
1164 		.prot =       &udp_prot,
1165 		.ops =        &inet_dgram_ops,
1166 		.flags =      INET_PROTOSW_PERMANENT,
1167        },
1168 
1169        {
1170 		.type =       SOCK_DGRAM,
1171 		.protocol =   IPPROTO_ICMP,
1172 		.prot =       &ping_prot,
1173 		.ops =        &inet_sockraw_ops,
1174 		.flags =      INET_PROTOSW_REUSE,
1175        },
1176 
1177        {
1178 	       .type =       SOCK_RAW,
1179 	       .protocol =   IPPROTO_IP,	/* wild card */
1180 	       .prot =       &raw_prot,
1181 	       .ops =        &inet_sockraw_ops,
1182 	       .flags =      INET_PROTOSW_REUSE,
1183        }
1184 };
1185 
1186 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1187 
1188 void inet_register_protosw(struct inet_protosw *p)
1189 {
1190 	struct list_head *lh;
1191 	struct inet_protosw *answer;
1192 	int protocol = p->protocol;
1193 	struct list_head *last_perm;
1194 
1195 	spin_lock_bh(&inetsw_lock);
1196 
1197 	if (p->type >= SOCK_MAX)
1198 		goto out_illegal;
1199 
1200 	/* If we are trying to override a permanent protocol, bail. */
1201 	last_perm = &inetsw[p->type];
1202 	list_for_each(lh, &inetsw[p->type]) {
1203 		answer = list_entry(lh, struct inet_protosw, list);
1204 		/* Check only the non-wild match. */
1205 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1206 			break;
1207 		if (protocol == answer->protocol)
1208 			goto out_permanent;
1209 		last_perm = lh;
1210 	}
1211 
1212 	/* Add the new entry after the last permanent entry if any, so that
1213 	 * the new entry does not override a permanent entry when matched with
1214 	 * a wild-card protocol. But it is allowed to override any existing
1215 	 * non-permanent entry.  This means that when we remove this entry, the
1216 	 * system automatically returns to the old behavior.
1217 	 */
1218 	list_add_rcu(&p->list, last_perm);
1219 out:
1220 	spin_unlock_bh(&inetsw_lock);
1221 
1222 	return;
1223 
1224 out_permanent:
1225 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1226 	goto out;
1227 
1228 out_illegal:
1229 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1230 	       p->type);
1231 	goto out;
1232 }
1233 EXPORT_SYMBOL(inet_register_protosw);
1234 
1235 void inet_unregister_protosw(struct inet_protosw *p)
1236 {
1237 	if (INET_PROTOSW_PERMANENT & p->flags) {
1238 		pr_err("Attempt to unregister permanent protocol %d\n",
1239 		       p->protocol);
1240 	} else {
1241 		spin_lock_bh(&inetsw_lock);
1242 		list_del_rcu(&p->list);
1243 		spin_unlock_bh(&inetsw_lock);
1244 
1245 		synchronize_net();
1246 	}
1247 }
1248 EXPORT_SYMBOL(inet_unregister_protosw);
1249 
1250 static int inet_sk_reselect_saddr(struct sock *sk)
1251 {
1252 	struct inet_sock *inet = inet_sk(sk);
1253 	__be32 old_saddr = inet->inet_saddr;
1254 	__be32 daddr = inet->inet_daddr;
1255 	struct flowi4 *fl4;
1256 	struct rtable *rt;
1257 	__be32 new_saddr;
1258 	struct ip_options_rcu *inet_opt;
1259 	int err;
1260 
1261 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1262 					     lockdep_sock_is_held(sk));
1263 	if (inet_opt && inet_opt->opt.srr)
1264 		daddr = inet_opt->opt.faddr;
1265 
1266 	/* Query new route. */
1267 	fl4 = &inet->cork.fl.u.ip4;
1268 	rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1269 			      sk->sk_protocol, inet->inet_sport,
1270 			      inet->inet_dport, sk);
1271 	if (IS_ERR(rt))
1272 		return PTR_ERR(rt);
1273 
1274 	new_saddr = fl4->saddr;
1275 
1276 	if (new_saddr == old_saddr) {
1277 		sk_setup_caps(sk, &rt->dst);
1278 		return 0;
1279 	}
1280 
1281 	err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1282 	if (err) {
1283 		ip_rt_put(rt);
1284 		return err;
1285 	}
1286 
1287 	sk_setup_caps(sk, &rt->dst);
1288 
1289 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1290 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1291 			__func__, &old_saddr, &new_saddr);
1292 	}
1293 
1294 	/*
1295 	 * XXX The only one ugly spot where we need to
1296 	 * XXX really change the sockets identity after
1297 	 * XXX it has entered the hashes. -DaveM
1298 	 *
1299 	 * Besides that, it does not check for connection
1300 	 * uniqueness. Wait for troubles.
1301 	 */
1302 	return __sk_prot_rehash(sk);
1303 }
1304 
1305 int inet_sk_rebuild_header(struct sock *sk)
1306 {
1307 	struct inet_sock *inet = inet_sk(sk);
1308 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1309 	__be32 daddr;
1310 	struct ip_options_rcu *inet_opt;
1311 	struct flowi4 *fl4;
1312 	int err;
1313 
1314 	/* Route is OK, nothing to do. */
1315 	if (rt)
1316 		return 0;
1317 
1318 	/* Reroute. */
1319 	rcu_read_lock();
1320 	inet_opt = rcu_dereference(inet->inet_opt);
1321 	daddr = inet->inet_daddr;
1322 	if (inet_opt && inet_opt->opt.srr)
1323 		daddr = inet_opt->opt.faddr;
1324 	rcu_read_unlock();
1325 	fl4 = &inet->cork.fl.u.ip4;
1326 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1327 				   inet->inet_dport, inet->inet_sport,
1328 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1329 				   sk->sk_bound_dev_if);
1330 	if (!IS_ERR(rt)) {
1331 		err = 0;
1332 		sk_setup_caps(sk, &rt->dst);
1333 	} else {
1334 		err = PTR_ERR(rt);
1335 
1336 		/* Routing failed... */
1337 		sk->sk_route_caps = 0;
1338 		/*
1339 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1340 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1341 		 */
1342 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1343 		    sk->sk_state != TCP_SYN_SENT ||
1344 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1345 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1346 			WRITE_ONCE(sk->sk_err_soft, -err);
1347 	}
1348 
1349 	return err;
1350 }
1351 EXPORT_SYMBOL(inet_sk_rebuild_header);
1352 
1353 void inet_sk_set_state(struct sock *sk, int state)
1354 {
1355 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1356 	sk->sk_state = state;
1357 }
1358 EXPORT_SYMBOL(inet_sk_set_state);
1359 
1360 void inet_sk_state_store(struct sock *sk, int newstate)
1361 {
1362 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1363 	smp_store_release(&sk->sk_state, newstate);
1364 }
1365 
1366 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1367 				 netdev_features_t features)
1368 {
1369 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1370 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1371 	const struct net_offload *ops;
1372 	unsigned int offset = 0;
1373 	struct iphdr *iph;
1374 	int proto, tot_len;
1375 	int nhoff;
1376 	int ihl;
1377 	int id;
1378 
1379 	skb_reset_network_header(skb);
1380 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1381 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1382 		goto out;
1383 
1384 	iph = ip_hdr(skb);
1385 	ihl = iph->ihl * 4;
1386 	if (ihl < sizeof(*iph))
1387 		goto out;
1388 
1389 	id = ntohs(iph->id);
1390 	proto = iph->protocol;
1391 
1392 	/* Warning: after this point, iph might be no longer valid */
1393 	if (unlikely(!pskb_may_pull(skb, ihl)))
1394 		goto out;
1395 	__skb_pull(skb, ihl);
1396 
1397 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1398 	if (encap)
1399 		features &= skb->dev->hw_enc_features;
1400 	SKB_GSO_CB(skb)->encap_level += ihl;
1401 
1402 	skb_reset_transport_header(skb);
1403 
1404 	segs = ERR_PTR(-EPROTONOSUPPORT);
1405 
1406 	if (!skb->encapsulation || encap) {
1407 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1408 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1409 
1410 		/* fixed ID is invalid if DF bit is not set */
1411 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1412 			goto out;
1413 	}
1414 
1415 	ops = rcu_dereference(inet_offloads[proto]);
1416 	if (likely(ops && ops->callbacks.gso_segment)) {
1417 		segs = ops->callbacks.gso_segment(skb, features);
1418 		if (!segs)
1419 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1420 	}
1421 
1422 	if (IS_ERR_OR_NULL(segs))
1423 		goto out;
1424 
1425 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1426 
1427 	skb = segs;
1428 	do {
1429 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1430 		if (udpfrag) {
1431 			iph->frag_off = htons(offset >> 3);
1432 			if (skb->next)
1433 				iph->frag_off |= htons(IP_MF);
1434 			offset += skb->len - nhoff - ihl;
1435 			tot_len = skb->len - nhoff;
1436 		} else if (skb_is_gso(skb)) {
1437 			if (!fixedid) {
1438 				iph->id = htons(id);
1439 				id += skb_shinfo(skb)->gso_segs;
1440 			}
1441 
1442 			if (gso_partial)
1443 				tot_len = skb_shinfo(skb)->gso_size +
1444 					  SKB_GSO_CB(skb)->data_offset +
1445 					  skb->head - (unsigned char *)iph;
1446 			else
1447 				tot_len = skb->len - nhoff;
1448 		} else {
1449 			if (!fixedid)
1450 				iph->id = htons(id++);
1451 			tot_len = skb->len - nhoff;
1452 		}
1453 		iph->tot_len = htons(tot_len);
1454 		ip_send_check(iph);
1455 		if (encap)
1456 			skb_reset_inner_headers(skb);
1457 		skb->network_header = (u8 *)iph - skb->head;
1458 		skb_reset_mac_len(skb);
1459 	} while ((skb = skb->next));
1460 
1461 out:
1462 	return segs;
1463 }
1464 
1465 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1466 					netdev_features_t features)
1467 {
1468 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1469 		return ERR_PTR(-EINVAL);
1470 
1471 	return inet_gso_segment(skb, features);
1472 }
1473 
1474 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1475 {
1476 	const struct net_offload *ops;
1477 	struct sk_buff *pp = NULL;
1478 	const struct iphdr *iph;
1479 	struct sk_buff *p;
1480 	unsigned int hlen;
1481 	unsigned int off;
1482 	unsigned int id;
1483 	int flush = 1;
1484 	int proto;
1485 
1486 	off = skb_gro_offset(skb);
1487 	hlen = off + sizeof(*iph);
1488 	iph = skb_gro_header(skb, hlen, off);
1489 	if (unlikely(!iph))
1490 		goto out;
1491 
1492 	proto = iph->protocol;
1493 
1494 	ops = rcu_dereference(inet_offloads[proto]);
1495 	if (!ops || !ops->callbacks.gro_receive)
1496 		goto out;
1497 
1498 	if (*(u8 *)iph != 0x45)
1499 		goto out;
1500 
1501 	if (ip_is_fragment(iph))
1502 		goto out;
1503 
1504 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1505 		goto out;
1506 
1507 	NAPI_GRO_CB(skb)->proto = proto;
1508 	id = ntohl(*(__be32 *)&iph->id);
1509 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1510 	id >>= 16;
1511 
1512 	list_for_each_entry(p, head, list) {
1513 		struct iphdr *iph2;
1514 		u16 flush_id;
1515 
1516 		if (!NAPI_GRO_CB(p)->same_flow)
1517 			continue;
1518 
1519 		iph2 = (struct iphdr *)(p->data + off);
1520 		/* The above works because, with the exception of the top
1521 		 * (inner most) layer, we only aggregate pkts with the same
1522 		 * hdr length so all the hdrs we'll need to verify will start
1523 		 * at the same offset.
1524 		 */
1525 		if ((iph->protocol ^ iph2->protocol) |
1526 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1527 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1528 			NAPI_GRO_CB(p)->same_flow = 0;
1529 			continue;
1530 		}
1531 
1532 		/* All fields must match except length and checksum. */
1533 		NAPI_GRO_CB(p)->flush |=
1534 			(iph->ttl ^ iph2->ttl) |
1535 			(iph->tos ^ iph2->tos) |
1536 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1537 
1538 		NAPI_GRO_CB(p)->flush |= flush;
1539 
1540 		/* We need to store of the IP ID check to be included later
1541 		 * when we can verify that this packet does in fact belong
1542 		 * to a given flow.
1543 		 */
1544 		flush_id = (u16)(id - ntohs(iph2->id));
1545 
1546 		/* This bit of code makes it much easier for us to identify
1547 		 * the cases where we are doing atomic vs non-atomic IP ID
1548 		 * checks.  Specifically an atomic check can return IP ID
1549 		 * values 0 - 0xFFFF, while a non-atomic check can only
1550 		 * return 0 or 0xFFFF.
1551 		 */
1552 		if (!NAPI_GRO_CB(p)->is_atomic ||
1553 		    !(iph->frag_off & htons(IP_DF))) {
1554 			flush_id ^= NAPI_GRO_CB(p)->count;
1555 			flush_id = flush_id ? 0xFFFF : 0;
1556 		}
1557 
1558 		/* If the previous IP ID value was based on an atomic
1559 		 * datagram we can overwrite the value and ignore it.
1560 		 */
1561 		if (NAPI_GRO_CB(skb)->is_atomic)
1562 			NAPI_GRO_CB(p)->flush_id = flush_id;
1563 		else
1564 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1565 	}
1566 
1567 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1568 	NAPI_GRO_CB(skb)->flush |= flush;
1569 	skb_set_network_header(skb, off);
1570 	/* The above will be needed by the transport layer if there is one
1571 	 * immediately following this IP hdr.
1572 	 */
1573 
1574 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1575 	 * as we already checked checksum over ipv4 header was 0
1576 	 */
1577 	skb_gro_pull(skb, sizeof(*iph));
1578 	skb_set_transport_header(skb, skb_gro_offset(skb));
1579 
1580 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1581 				       ops->callbacks.gro_receive, head, skb);
1582 
1583 out:
1584 	skb_gro_flush_final(skb, pp, flush);
1585 
1586 	return pp;
1587 }
1588 
1589 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1590 					struct sk_buff *skb)
1591 {
1592 	if (NAPI_GRO_CB(skb)->encap_mark) {
1593 		NAPI_GRO_CB(skb)->flush = 1;
1594 		return NULL;
1595 	}
1596 
1597 	NAPI_GRO_CB(skb)->encap_mark = 1;
1598 
1599 	return inet_gro_receive(head, skb);
1600 }
1601 
1602 #define SECONDS_PER_DAY	86400
1603 
1604 /* inet_current_timestamp - Return IP network timestamp
1605  *
1606  * Return milliseconds since midnight in network byte order.
1607  */
1608 __be32 inet_current_timestamp(void)
1609 {
1610 	u32 secs;
1611 	u32 msecs;
1612 	struct timespec64 ts;
1613 
1614 	ktime_get_real_ts64(&ts);
1615 
1616 	/* Get secs since midnight. */
1617 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1618 	/* Convert to msecs. */
1619 	msecs = secs * MSEC_PER_SEC;
1620 	/* Convert nsec to msec. */
1621 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1622 
1623 	/* Convert to network byte order. */
1624 	return htonl(msecs);
1625 }
1626 EXPORT_SYMBOL(inet_current_timestamp);
1627 
1628 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1629 {
1630 	if (sk->sk_family == AF_INET)
1631 		return ip_recv_error(sk, msg, len, addr_len);
1632 #if IS_ENABLED(CONFIG_IPV6)
1633 	if (sk->sk_family == AF_INET6)
1634 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1635 #endif
1636 	return -EINVAL;
1637 }
1638 EXPORT_SYMBOL(inet_recv_error);
1639 
1640 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1641 {
1642 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1643 	const struct net_offload *ops;
1644 	__be16 totlen = iph->tot_len;
1645 	int proto = iph->protocol;
1646 	int err = -ENOSYS;
1647 
1648 	if (skb->encapsulation) {
1649 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1650 		skb_set_inner_network_header(skb, nhoff);
1651 	}
1652 
1653 	iph_set_totlen(iph, skb->len - nhoff);
1654 	csum_replace2(&iph->check, totlen, iph->tot_len);
1655 
1656 	ops = rcu_dereference(inet_offloads[proto]);
1657 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1658 		goto out;
1659 
1660 	/* Only need to add sizeof(*iph) to get to the next hdr below
1661 	 * because any hdr with option will have been flushed in
1662 	 * inet_gro_receive().
1663 	 */
1664 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1665 			      tcp4_gro_complete, udp4_gro_complete,
1666 			      skb, nhoff + sizeof(*iph));
1667 
1668 out:
1669 	return err;
1670 }
1671 
1672 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1673 {
1674 	skb->encapsulation = 1;
1675 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1676 	return inet_gro_complete(skb, nhoff);
1677 }
1678 
1679 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1680 			 unsigned short type, unsigned char protocol,
1681 			 struct net *net)
1682 {
1683 	struct socket *sock;
1684 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1685 
1686 	if (rc == 0) {
1687 		*sk = sock->sk;
1688 		(*sk)->sk_allocation = GFP_ATOMIC;
1689 		(*sk)->sk_use_task_frag = false;
1690 		/*
1691 		 * Unhash it so that IP input processing does not even see it,
1692 		 * we do not wish this socket to see incoming packets.
1693 		 */
1694 		(*sk)->sk_prot->unhash(*sk);
1695 	}
1696 	return rc;
1697 }
1698 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1699 
1700 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1701 {
1702 	unsigned long res = 0;
1703 	int i;
1704 
1705 	for_each_possible_cpu(i)
1706 		res += snmp_get_cpu_field(mib, i, offt);
1707 	return res;
1708 }
1709 EXPORT_SYMBOL_GPL(snmp_fold_field);
1710 
1711 #if BITS_PER_LONG==32
1712 
1713 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1714 			 size_t syncp_offset)
1715 {
1716 	void *bhptr;
1717 	struct u64_stats_sync *syncp;
1718 	u64 v;
1719 	unsigned int start;
1720 
1721 	bhptr = per_cpu_ptr(mib, cpu);
1722 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1723 	do {
1724 		start = u64_stats_fetch_begin(syncp);
1725 		v = *(((u64 *)bhptr) + offt);
1726 	} while (u64_stats_fetch_retry(syncp, start));
1727 
1728 	return v;
1729 }
1730 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1731 
1732 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1733 {
1734 	u64 res = 0;
1735 	int cpu;
1736 
1737 	for_each_possible_cpu(cpu) {
1738 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1739 	}
1740 	return res;
1741 }
1742 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1743 #endif
1744 
1745 #ifdef CONFIG_IP_MULTICAST
1746 static const struct net_protocol igmp_protocol = {
1747 	.handler =	igmp_rcv,
1748 };
1749 #endif
1750 
1751 static const struct net_protocol tcp_protocol = {
1752 	.handler	=	tcp_v4_rcv,
1753 	.err_handler	=	tcp_v4_err,
1754 	.no_policy	=	1,
1755 	.icmp_strict_tag_validation = 1,
1756 };
1757 
1758 static const struct net_protocol udp_protocol = {
1759 	.handler =	udp_rcv,
1760 	.err_handler =	udp_err,
1761 	.no_policy =	1,
1762 };
1763 
1764 static const struct net_protocol icmp_protocol = {
1765 	.handler =	icmp_rcv,
1766 	.err_handler =	icmp_err,
1767 	.no_policy =	1,
1768 };
1769 
1770 static __net_init int ipv4_mib_init_net(struct net *net)
1771 {
1772 	int i;
1773 
1774 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1775 	if (!net->mib.tcp_statistics)
1776 		goto err_tcp_mib;
1777 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1778 	if (!net->mib.ip_statistics)
1779 		goto err_ip_mib;
1780 
1781 	for_each_possible_cpu(i) {
1782 		struct ipstats_mib *af_inet_stats;
1783 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1784 		u64_stats_init(&af_inet_stats->syncp);
1785 	}
1786 
1787 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1788 	if (!net->mib.net_statistics)
1789 		goto err_net_mib;
1790 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1791 	if (!net->mib.udp_statistics)
1792 		goto err_udp_mib;
1793 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1794 	if (!net->mib.udplite_statistics)
1795 		goto err_udplite_mib;
1796 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1797 	if (!net->mib.icmp_statistics)
1798 		goto err_icmp_mib;
1799 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1800 					      GFP_KERNEL);
1801 	if (!net->mib.icmpmsg_statistics)
1802 		goto err_icmpmsg_mib;
1803 
1804 	tcp_mib_init(net);
1805 	return 0;
1806 
1807 err_icmpmsg_mib:
1808 	free_percpu(net->mib.icmp_statistics);
1809 err_icmp_mib:
1810 	free_percpu(net->mib.udplite_statistics);
1811 err_udplite_mib:
1812 	free_percpu(net->mib.udp_statistics);
1813 err_udp_mib:
1814 	free_percpu(net->mib.net_statistics);
1815 err_net_mib:
1816 	free_percpu(net->mib.ip_statistics);
1817 err_ip_mib:
1818 	free_percpu(net->mib.tcp_statistics);
1819 err_tcp_mib:
1820 	return -ENOMEM;
1821 }
1822 
1823 static __net_exit void ipv4_mib_exit_net(struct net *net)
1824 {
1825 	kfree(net->mib.icmpmsg_statistics);
1826 	free_percpu(net->mib.icmp_statistics);
1827 	free_percpu(net->mib.udplite_statistics);
1828 	free_percpu(net->mib.udp_statistics);
1829 	free_percpu(net->mib.net_statistics);
1830 	free_percpu(net->mib.ip_statistics);
1831 	free_percpu(net->mib.tcp_statistics);
1832 #ifdef CONFIG_MPTCP
1833 	/* allocated on demand, see mptcp_init_sock() */
1834 	free_percpu(net->mib.mptcp_statistics);
1835 #endif
1836 }
1837 
1838 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1839 	.init = ipv4_mib_init_net,
1840 	.exit = ipv4_mib_exit_net,
1841 };
1842 
1843 static int __init init_ipv4_mibs(void)
1844 {
1845 	return register_pernet_subsys(&ipv4_mib_ops);
1846 }
1847 
1848 static __net_init int inet_init_net(struct net *net)
1849 {
1850 	/*
1851 	 * Set defaults for local port range
1852 	 */
1853 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1854 	net->ipv4.ip_local_ports.range[0] =  32768;
1855 	net->ipv4.ip_local_ports.range[1] =  60999;
1856 
1857 	seqlock_init(&net->ipv4.ping_group_range.lock);
1858 	/*
1859 	 * Sane defaults - nobody may create ping sockets.
1860 	 * Boot scripts should set this to distro-specific group.
1861 	 */
1862 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1863 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1864 
1865 	/* Default values for sysctl-controlled parameters.
1866 	 * We set them here, in case sysctl is not compiled.
1867 	 */
1868 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1869 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1870 	net->ipv4.sysctl_ip_dynaddr = 0;
1871 	net->ipv4.sysctl_ip_early_demux = 1;
1872 	net->ipv4.sysctl_udp_early_demux = 1;
1873 	net->ipv4.sysctl_tcp_early_demux = 1;
1874 	net->ipv4.sysctl_nexthop_compat_mode = 1;
1875 #ifdef CONFIG_SYSCTL
1876 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1877 #endif
1878 
1879 	/* Some igmp sysctl, whose values are always used */
1880 	net->ipv4.sysctl_igmp_max_memberships = 20;
1881 	net->ipv4.sysctl_igmp_max_msf = 10;
1882 	/* IGMP reports for link-local multicast groups are enabled by default */
1883 	net->ipv4.sysctl_igmp_llm_reports = 1;
1884 	net->ipv4.sysctl_igmp_qrv = 2;
1885 
1886 	net->ipv4.sysctl_fib_notify_on_flag_change = 0;
1887 
1888 	return 0;
1889 }
1890 
1891 static __net_initdata struct pernet_operations af_inet_ops = {
1892 	.init = inet_init_net,
1893 };
1894 
1895 static int __init init_inet_pernet_ops(void)
1896 {
1897 	return register_pernet_subsys(&af_inet_ops);
1898 }
1899 
1900 static int ipv4_proc_init(void);
1901 
1902 /*
1903  *	IP protocol layer initialiser
1904  */
1905 
1906 static struct packet_offload ip_packet_offload __read_mostly = {
1907 	.type = cpu_to_be16(ETH_P_IP),
1908 	.callbacks = {
1909 		.gso_segment = inet_gso_segment,
1910 		.gro_receive = inet_gro_receive,
1911 		.gro_complete = inet_gro_complete,
1912 	},
1913 };
1914 
1915 static const struct net_offload ipip_offload = {
1916 	.callbacks = {
1917 		.gso_segment	= ipip_gso_segment,
1918 		.gro_receive	= ipip_gro_receive,
1919 		.gro_complete	= ipip_gro_complete,
1920 	},
1921 };
1922 
1923 static int __init ipip_offload_init(void)
1924 {
1925 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1926 }
1927 
1928 static int __init ipv4_offload_init(void)
1929 {
1930 	/*
1931 	 * Add offloads
1932 	 */
1933 	if (udpv4_offload_init() < 0)
1934 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1935 	if (tcpv4_offload_init() < 0)
1936 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1937 	if (ipip_offload_init() < 0)
1938 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1939 
1940 	dev_add_offload(&ip_packet_offload);
1941 	return 0;
1942 }
1943 
1944 fs_initcall(ipv4_offload_init);
1945 
1946 static struct packet_type ip_packet_type __read_mostly = {
1947 	.type = cpu_to_be16(ETH_P_IP),
1948 	.func = ip_rcv,
1949 	.list_func = ip_list_rcv,
1950 };
1951 
1952 static int __init inet_init(void)
1953 {
1954 	struct inet_protosw *q;
1955 	struct list_head *r;
1956 	int rc;
1957 
1958 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1959 
1960 	raw_hashinfo_init(&raw_v4_hashinfo);
1961 
1962 	rc = proto_register(&tcp_prot, 1);
1963 	if (rc)
1964 		goto out;
1965 
1966 	rc = proto_register(&udp_prot, 1);
1967 	if (rc)
1968 		goto out_unregister_tcp_proto;
1969 
1970 	rc = proto_register(&raw_prot, 1);
1971 	if (rc)
1972 		goto out_unregister_udp_proto;
1973 
1974 	rc = proto_register(&ping_prot, 1);
1975 	if (rc)
1976 		goto out_unregister_raw_proto;
1977 
1978 	/*
1979 	 *	Tell SOCKET that we are alive...
1980 	 */
1981 
1982 	(void)sock_register(&inet_family_ops);
1983 
1984 #ifdef CONFIG_SYSCTL
1985 	ip_static_sysctl_init();
1986 #endif
1987 
1988 	/*
1989 	 *	Add all the base protocols.
1990 	 */
1991 
1992 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1993 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1994 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1995 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1996 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1997 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1998 #ifdef CONFIG_IP_MULTICAST
1999 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
2000 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
2001 #endif
2002 
2003 	/* Register the socket-side information for inet_create. */
2004 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
2005 		INIT_LIST_HEAD(r);
2006 
2007 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
2008 		inet_register_protosw(q);
2009 
2010 	/*
2011 	 *	Set the ARP module up
2012 	 */
2013 
2014 	arp_init();
2015 
2016 	/*
2017 	 *	Set the IP module up
2018 	 */
2019 
2020 	ip_init();
2021 
2022 	/* Initialise per-cpu ipv4 mibs */
2023 	if (init_ipv4_mibs())
2024 		panic("%s: Cannot init ipv4 mibs\n", __func__);
2025 
2026 	/* Setup TCP slab cache for open requests. */
2027 	tcp_init();
2028 
2029 	/* Setup UDP memory threshold */
2030 	udp_init();
2031 
2032 	/* Add UDP-Lite (RFC 3828) */
2033 	udplite4_register();
2034 
2035 	raw_init();
2036 
2037 	ping_init();
2038 
2039 	/*
2040 	 *	Set the ICMP layer up
2041 	 */
2042 
2043 	if (icmp_init() < 0)
2044 		panic("Failed to create the ICMP control socket.\n");
2045 
2046 	/*
2047 	 *	Initialise the multicast router
2048 	 */
2049 #if defined(CONFIG_IP_MROUTE)
2050 	if (ip_mr_init())
2051 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2052 #endif
2053 
2054 	if (init_inet_pernet_ops())
2055 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2056 
2057 	ipv4_proc_init();
2058 
2059 	ipfrag_init();
2060 
2061 	dev_add_pack(&ip_packet_type);
2062 
2063 	ip_tunnel_core_init();
2064 
2065 	rc = 0;
2066 out:
2067 	return rc;
2068 out_unregister_raw_proto:
2069 	proto_unregister(&raw_prot);
2070 out_unregister_udp_proto:
2071 	proto_unregister(&udp_prot);
2072 out_unregister_tcp_proto:
2073 	proto_unregister(&tcp_prot);
2074 	goto out;
2075 }
2076 
2077 fs_initcall(inet_init);
2078 
2079 /* ------------------------------------------------------------------------ */
2080 
2081 #ifdef CONFIG_PROC_FS
2082 static int __init ipv4_proc_init(void)
2083 {
2084 	int rc = 0;
2085 
2086 	if (raw_proc_init())
2087 		goto out_raw;
2088 	if (tcp4_proc_init())
2089 		goto out_tcp;
2090 	if (udp4_proc_init())
2091 		goto out_udp;
2092 	if (ping_proc_init())
2093 		goto out_ping;
2094 	if (ip_misc_proc_init())
2095 		goto out_misc;
2096 out:
2097 	return rc;
2098 out_misc:
2099 	ping_proc_exit();
2100 out_ping:
2101 	udp4_proc_exit();
2102 out_udp:
2103 	tcp4_proc_exit();
2104 out_tcp:
2105 	raw_proc_exit();
2106 out_raw:
2107 	rc = -ENOMEM;
2108 	goto out;
2109 }
2110 
2111 #else /* CONFIG_PROC_FS */
2112 static int __init ipv4_proc_init(void)
2113 {
2114 	return 0;
2115 }
2116 #endif /* CONFIG_PROC_FS */
2117