xref: /openbmc/linux/net/ipv4/af_inet.c (revision e71383fb9cd15a28d6c01d2c165a96f1c0bcf418)
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/tcp.h>
104 #include <net/udp.h>
105 #include <net/udplite.h>
106 #include <net/ping.h>
107 #include <linux/skbuff.h>
108 #include <net/sock.h>
109 #include <net/raw.h>
110 #include <net/icmp.h>
111 #include <net/inet_common.h>
112 #include <net/ip_tunnels.h>
113 #include <net/xfrm.h>
114 #include <net/net_namespace.h>
115 #include <net/secure_seq.h>
116 #ifdef CONFIG_IP_MROUTE
117 #include <linux/mroute.h>
118 #endif
119 #include <net/l3mdev.h>
120 #include <net/compat.h>
121 
122 #include <trace/events/sock.h>
123 
124 /* The inetsw table contains everything that inet_create needs to
125  * build a new socket.
126  */
127 static struct list_head inetsw[SOCK_MAX];
128 static DEFINE_SPINLOCK(inetsw_lock);
129 
130 /* New destruction routine */
131 
132 void inet_sock_destruct(struct sock *sk)
133 {
134 	struct inet_sock *inet = inet_sk(sk);
135 
136 	__skb_queue_purge(&sk->sk_receive_queue);
137 	__skb_queue_purge(&sk->sk_error_queue);
138 
139 	sk_mem_reclaim_final(sk);
140 
141 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
142 		pr_err("Attempt to release TCP socket in state %d %p\n",
143 		       sk->sk_state, sk);
144 		return;
145 	}
146 	if (!sock_flag(sk, SOCK_DEAD)) {
147 		pr_err("Attempt to release alive inet socket %p\n", sk);
148 		return;
149 	}
150 
151 	WARN_ON_ONCE(atomic_read(&sk->sk_rmem_alloc));
152 	WARN_ON_ONCE(refcount_read(&sk->sk_wmem_alloc));
153 	WARN_ON_ONCE(sk->sk_wmem_queued);
154 	WARN_ON_ONCE(sk_forward_alloc_get(sk));
155 
156 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
157 	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
158 	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
159 }
160 EXPORT_SYMBOL(inet_sock_destruct);
161 
162 /*
163  *	The routines beyond this point handle the behaviour of an AF_INET
164  *	socket object. Mostly it punts to the subprotocols of IP to do
165  *	the work.
166  */
167 
168 /*
169  *	Automatically bind an unbound socket.
170  */
171 
172 static int inet_autobind(struct sock *sk)
173 {
174 	struct inet_sock *inet;
175 	/* We may need to bind the socket. */
176 	lock_sock(sk);
177 	inet = inet_sk(sk);
178 	if (!inet->inet_num) {
179 		if (sk->sk_prot->get_port(sk, 0)) {
180 			release_sock(sk);
181 			return -EAGAIN;
182 		}
183 		inet->inet_sport = htons(inet->inet_num);
184 	}
185 	release_sock(sk);
186 	return 0;
187 }
188 
189 /*
190  *	Move a socket into listening state.
191  */
192 int inet_listen(struct socket *sock, int backlog)
193 {
194 	struct sock *sk = sock->sk;
195 	unsigned char old_state;
196 	int err, tcp_fastopen;
197 
198 	lock_sock(sk);
199 
200 	err = -EINVAL;
201 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
202 		goto out;
203 
204 	old_state = sk->sk_state;
205 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
206 		goto out;
207 
208 	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
209 	/* Really, if the socket is already in listen state
210 	 * we can only allow the backlog to be adjusted.
211 	 */
212 	if (old_state != TCP_LISTEN) {
213 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
214 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
215 		 * Also fastopen backlog may already been set via the option
216 		 * because the socket was in TCP_LISTEN state previously but
217 		 * was shutdown() rather than close().
218 		 */
219 		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
220 		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
221 		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
222 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
223 			fastopen_queue_tune(sk, backlog);
224 			tcp_fastopen_init_key_once(sock_net(sk));
225 		}
226 
227 		err = inet_csk_listen_start(sk);
228 		if (err)
229 			goto out;
230 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
231 	}
232 	err = 0;
233 
234 out:
235 	release_sock(sk);
236 	return err;
237 }
238 EXPORT_SYMBOL(inet_listen);
239 
240 /*
241  *	Create an inet socket.
242  */
243 
244 static int inet_create(struct net *net, struct socket *sock, int protocol,
245 		       int kern)
246 {
247 	struct sock *sk;
248 	struct inet_protosw *answer;
249 	struct inet_sock *inet;
250 	struct proto *answer_prot;
251 	unsigned char answer_flags;
252 	int try_loading_module = 0;
253 	int err;
254 
255 	if (protocol < 0 || protocol >= IPPROTO_MAX)
256 		return -EINVAL;
257 
258 	sock->state = SS_UNCONNECTED;
259 
260 	/* Look for the requested type/protocol pair. */
261 lookup_protocol:
262 	err = -ESOCKTNOSUPPORT;
263 	rcu_read_lock();
264 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
265 
266 		err = 0;
267 		/* Check the non-wild match. */
268 		if (protocol == answer->protocol) {
269 			if (protocol != IPPROTO_IP)
270 				break;
271 		} else {
272 			/* Check for the two wild cases. */
273 			if (IPPROTO_IP == protocol) {
274 				protocol = answer->protocol;
275 				break;
276 			}
277 			if (IPPROTO_IP == answer->protocol)
278 				break;
279 		}
280 		err = -EPROTONOSUPPORT;
281 	}
282 
283 	if (unlikely(err)) {
284 		if (try_loading_module < 2) {
285 			rcu_read_unlock();
286 			/*
287 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
288 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
289 			 */
290 			if (++try_loading_module == 1)
291 				request_module("net-pf-%d-proto-%d-type-%d",
292 					       PF_INET, protocol, sock->type);
293 			/*
294 			 * Fall back to generic, e.g. net-pf-2-proto-132
295 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
296 			 */
297 			else
298 				request_module("net-pf-%d-proto-%d",
299 					       PF_INET, protocol);
300 			goto lookup_protocol;
301 		} else
302 			goto out_rcu_unlock;
303 	}
304 
305 	err = -EPERM;
306 	if (sock->type == SOCK_RAW && !kern &&
307 	    !ns_capable(net->user_ns, CAP_NET_RAW))
308 		goto out_rcu_unlock;
309 
310 	sock->ops = answer->ops;
311 	answer_prot = answer->prot;
312 	answer_flags = answer->flags;
313 	rcu_read_unlock();
314 
315 	WARN_ON(!answer_prot->slab);
316 
317 	err = -ENOMEM;
318 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
319 	if (!sk)
320 		goto out;
321 
322 	err = 0;
323 	if (INET_PROTOSW_REUSE & answer_flags)
324 		sk->sk_reuse = SK_CAN_REUSE;
325 
326 	inet = inet_sk(sk);
327 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
328 
329 	inet->nodefrag = 0;
330 
331 	if (SOCK_RAW == sock->type) {
332 		inet->inet_num = protocol;
333 		if (IPPROTO_RAW == protocol)
334 			inet->hdrincl = 1;
335 	}
336 
337 	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
338 		inet->pmtudisc = IP_PMTUDISC_DONT;
339 	else
340 		inet->pmtudisc = IP_PMTUDISC_WANT;
341 
342 	inet->inet_id = 0;
343 
344 	sock_init_data(sock, sk);
345 
346 	sk->sk_destruct	   = inet_sock_destruct;
347 	sk->sk_protocol	   = protocol;
348 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
349 	sk->sk_txrehash = READ_ONCE(net->core.sysctl_txrehash);
350 
351 	inet->uc_ttl	= -1;
352 	inet->mc_loop	= 1;
353 	inet->mc_ttl	= 1;
354 	inet->mc_all	= 1;
355 	inet->mc_index	= 0;
356 	inet->mc_list	= NULL;
357 	inet->rcv_tos	= 0;
358 
359 	if (inet->inet_num) {
360 		/* It assumes that any protocol which allows
361 		 * the user to assign a number at socket
362 		 * creation time automatically
363 		 * shares.
364 		 */
365 		inet->inet_sport = htons(inet->inet_num);
366 		/* Add to protocol hash chains. */
367 		err = sk->sk_prot->hash(sk);
368 		if (err) {
369 			sk_common_release(sk);
370 			goto out;
371 		}
372 	}
373 
374 	if (sk->sk_prot->init) {
375 		err = sk->sk_prot->init(sk);
376 		if (err) {
377 			sk_common_release(sk);
378 			goto out;
379 		}
380 	}
381 
382 	if (!kern) {
383 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
384 		if (err) {
385 			sk_common_release(sk);
386 			goto out;
387 		}
388 	}
389 out:
390 	return err;
391 out_rcu_unlock:
392 	rcu_read_unlock();
393 	goto out;
394 }
395 
396 
397 /*
398  *	The peer socket should always be NULL (or else). When we call this
399  *	function we are destroying the object and from then on nobody
400  *	should refer to it.
401  */
402 int inet_release(struct socket *sock)
403 {
404 	struct sock *sk = sock->sk;
405 
406 	if (sk) {
407 		long timeout;
408 
409 		if (!sk->sk_kern_sock)
410 			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
411 
412 		/* Applications forget to leave groups before exiting */
413 		ip_mc_drop_socket(sk);
414 
415 		/* If linger is set, we don't return until the close
416 		 * is complete.  Otherwise we return immediately. The
417 		 * actually closing is done the same either way.
418 		 *
419 		 * If the close is due to the process exiting, we never
420 		 * linger..
421 		 */
422 		timeout = 0;
423 		if (sock_flag(sk, SOCK_LINGER) &&
424 		    !(current->flags & PF_EXITING))
425 			timeout = sk->sk_lingertime;
426 		sk->sk_prot->close(sk, timeout);
427 		sock->sk = NULL;
428 	}
429 	return 0;
430 }
431 EXPORT_SYMBOL(inet_release);
432 
433 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
434 {
435 	struct sock *sk = sock->sk;
436 	u32 flags = BIND_WITH_LOCK;
437 	int err;
438 
439 	/* If the socket has its own bind function then use it. (RAW) */
440 	if (sk->sk_prot->bind) {
441 		return sk->sk_prot->bind(sk, uaddr, addr_len);
442 	}
443 	if (addr_len < sizeof(struct sockaddr_in))
444 		return -EINVAL;
445 
446 	/* BPF prog is run before any checks are done so that if the prog
447 	 * changes context in a wrong way it will be caught.
448 	 */
449 	err = BPF_CGROUP_RUN_PROG_INET_BIND_LOCK(sk, uaddr,
450 						 CGROUP_INET4_BIND, &flags);
451 	if (err)
452 		return err;
453 
454 	return __inet_bind(sk, uaddr, addr_len, flags);
455 }
456 EXPORT_SYMBOL(inet_bind);
457 
458 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
459 		u32 flags)
460 {
461 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
462 	struct inet_sock *inet = inet_sk(sk);
463 	struct net *net = sock_net(sk);
464 	unsigned short snum;
465 	int chk_addr_ret;
466 	u32 tb_id = RT_TABLE_LOCAL;
467 	int err;
468 
469 	if (addr->sin_family != AF_INET) {
470 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
471 		 * only if s_addr is INADDR_ANY.
472 		 */
473 		err = -EAFNOSUPPORT;
474 		if (addr->sin_family != AF_UNSPEC ||
475 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
476 			goto out;
477 	}
478 
479 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
480 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
481 
482 	/* Not specified by any standard per-se, however it breaks too
483 	 * many applications when removed.  It is unfortunate since
484 	 * allowing applications to make a non-local bind solves
485 	 * several problems with systems using dynamic addressing.
486 	 * (ie. your servers still start up even if your ISDN link
487 	 *  is temporarily down)
488 	 */
489 	err = -EADDRNOTAVAIL;
490 	if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,
491 	                                 chk_addr_ret))
492 		goto out;
493 
494 	snum = ntohs(addr->sin_port);
495 	err = -EACCES;
496 	if (!(flags & BIND_NO_CAP_NET_BIND_SERVICE) &&
497 	    snum && inet_port_requires_bind_service(net, snum) &&
498 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
499 		goto out;
500 
501 	/*      We keep a pair of addresses. rcv_saddr is the one
502 	 *      used by hash lookups, and saddr is used for transmit.
503 	 *
504 	 *      In the BSD API these are the same except where it
505 	 *      would be illegal to use them (multicast/broadcast) in
506 	 *      which case the sending device address is used.
507 	 */
508 	if (flags & BIND_WITH_LOCK)
509 		lock_sock(sk);
510 
511 	/* Check these errors (active socket, double bind). */
512 	err = -EINVAL;
513 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
514 		goto out_release_sock;
515 
516 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
517 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
518 		inet->inet_saddr = 0;  /* Use device */
519 
520 	/* Make sure we are allowed to bind here. */
521 	if (snum || !(inet->bind_address_no_port ||
522 		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
523 		err = sk->sk_prot->get_port(sk, snum);
524 		if (err) {
525 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
526 			goto out_release_sock;
527 		}
528 		if (!(flags & BIND_FROM_BPF)) {
529 			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
530 			if (err) {
531 				inet->inet_saddr = inet->inet_rcv_saddr = 0;
532 				if (sk->sk_prot->put_port)
533 					sk->sk_prot->put_port(sk);
534 				goto out_release_sock;
535 			}
536 		}
537 	}
538 
539 	if (inet->inet_rcv_saddr)
540 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
541 	if (snum)
542 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
543 	inet->inet_sport = htons(inet->inet_num);
544 	inet->inet_daddr = 0;
545 	inet->inet_dport = 0;
546 	sk_dst_reset(sk);
547 	err = 0;
548 out_release_sock:
549 	if (flags & BIND_WITH_LOCK)
550 		release_sock(sk);
551 out:
552 	return err;
553 }
554 
555 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
556 		       int addr_len, int flags)
557 {
558 	struct sock *sk = sock->sk;
559 	const struct proto *prot;
560 	int err;
561 
562 	if (addr_len < sizeof(uaddr->sa_family))
563 		return -EINVAL;
564 
565 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
566 	prot = READ_ONCE(sk->sk_prot);
567 
568 	if (uaddr->sa_family == AF_UNSPEC)
569 		return prot->disconnect(sk, flags);
570 
571 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
572 		err = prot->pre_connect(sk, uaddr, addr_len);
573 		if (err)
574 			return err;
575 	}
576 
577 	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
578 		return -EAGAIN;
579 	return prot->connect(sk, uaddr, addr_len);
580 }
581 EXPORT_SYMBOL(inet_dgram_connect);
582 
583 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
584 {
585 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
586 
587 	add_wait_queue(sk_sleep(sk), &wait);
588 	sk->sk_write_pending += writebias;
589 	sk->sk_wait_pending++;
590 
591 	/* Basic assumption: if someone sets sk->sk_err, he _must_
592 	 * change state of the socket from TCP_SYN_*.
593 	 * Connect() does not allow to get error notifications
594 	 * without closing the socket.
595 	 */
596 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
597 		release_sock(sk);
598 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
599 		lock_sock(sk);
600 		if (signal_pending(current) || !timeo)
601 			break;
602 	}
603 	remove_wait_queue(sk_sleep(sk), &wait);
604 	sk->sk_write_pending -= writebias;
605 	sk->sk_wait_pending--;
606 	return timeo;
607 }
608 
609 /*
610  *	Connect to a remote host. There is regrettably still a little
611  *	TCP 'magic' in here.
612  */
613 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
614 			  int addr_len, int flags, int is_sendmsg)
615 {
616 	struct sock *sk = sock->sk;
617 	int err;
618 	long timeo;
619 
620 	/*
621 	 * uaddr can be NULL and addr_len can be 0 if:
622 	 * sk is a TCP fastopen active socket and
623 	 * TCP_FASTOPEN_CONNECT sockopt is set and
624 	 * we already have a valid cookie for this socket.
625 	 * In this case, user can call write() after connect().
626 	 * write() will invoke tcp_sendmsg_fastopen() which calls
627 	 * __inet_stream_connect().
628 	 */
629 	if (uaddr) {
630 		if (addr_len < sizeof(uaddr->sa_family))
631 			return -EINVAL;
632 
633 		if (uaddr->sa_family == AF_UNSPEC) {
634 			err = sk->sk_prot->disconnect(sk, flags);
635 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
636 			goto out;
637 		}
638 	}
639 
640 	switch (sock->state) {
641 	default:
642 		err = -EINVAL;
643 		goto out;
644 	case SS_CONNECTED:
645 		err = -EISCONN;
646 		goto out;
647 	case SS_CONNECTING:
648 		if (inet_sk(sk)->defer_connect)
649 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
650 		else
651 			err = -EALREADY;
652 		/* Fall out of switch with err, set for this state */
653 		break;
654 	case SS_UNCONNECTED:
655 		err = -EISCONN;
656 		if (sk->sk_state != TCP_CLOSE)
657 			goto out;
658 
659 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
660 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
661 			if (err)
662 				goto out;
663 		}
664 
665 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
666 		if (err < 0)
667 			goto out;
668 
669 		sock->state = SS_CONNECTING;
670 
671 		if (!err && inet_sk(sk)->defer_connect)
672 			goto out;
673 
674 		/* Just entered SS_CONNECTING state; the only
675 		 * difference is that return value in non-blocking
676 		 * case is EINPROGRESS, rather than EALREADY.
677 		 */
678 		err = -EINPROGRESS;
679 		break;
680 	}
681 
682 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
683 
684 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
685 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
686 				tcp_sk(sk)->fastopen_req &&
687 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
688 
689 		/* Error code is set above */
690 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
691 			goto out;
692 
693 		err = sock_intr_errno(timeo);
694 		if (signal_pending(current))
695 			goto out;
696 	}
697 
698 	/* Connection was closed by RST, timeout, ICMP error
699 	 * or another process disconnected us.
700 	 */
701 	if (sk->sk_state == TCP_CLOSE)
702 		goto sock_error;
703 
704 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
705 	 * and error was received after socket entered established state.
706 	 * Hence, it is handled normally after connect() return successfully.
707 	 */
708 
709 	sock->state = SS_CONNECTED;
710 	err = 0;
711 out:
712 	return err;
713 
714 sock_error:
715 	err = sock_error(sk) ? : -ECONNABORTED;
716 	sock->state = SS_UNCONNECTED;
717 	if (sk->sk_prot->disconnect(sk, flags))
718 		sock->state = SS_DISCONNECTING;
719 	goto out;
720 }
721 EXPORT_SYMBOL(__inet_stream_connect);
722 
723 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
724 			int addr_len, int flags)
725 {
726 	int err;
727 
728 	lock_sock(sock->sk);
729 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
730 	release_sock(sock->sk);
731 	return err;
732 }
733 EXPORT_SYMBOL(inet_stream_connect);
734 
735 void __inet_accept(struct socket *sock, struct socket *newsock, struct sock *newsk)
736 {
737 	sock_rps_record_flow(newsk);
738 	WARN_ON(!((1 << newsk->sk_state) &
739 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
740 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
741 
742 	if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
743 		set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
744 	sock_graft(newsk, newsock);
745 
746 	newsock->state = SS_CONNECTED;
747 }
748 
749 /*
750  *	Accept a pending connection. The TCP layer now gives BSD semantics.
751  */
752 
753 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
754 		bool kern)
755 {
756 	struct sock *sk1 = sock->sk, *sk2;
757 	int err = -EINVAL;
758 
759 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
760 	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
761 	if (!sk2)
762 		return err;
763 
764 	lock_sock(sk2);
765 	__inet_accept(sock, newsock, sk2);
766 	release_sock(sk2);
767 	return 0;
768 }
769 EXPORT_SYMBOL(inet_accept);
770 
771 /*
772  *	This does both peername and sockname.
773  */
774 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
775 		 int peer)
776 {
777 	struct sock *sk		= sock->sk;
778 	struct inet_sock *inet	= inet_sk(sk);
779 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
780 
781 	sin->sin_family = AF_INET;
782 	lock_sock(sk);
783 	if (peer) {
784 		if (!inet->inet_dport ||
785 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
786 		     peer == 1)) {
787 			release_sock(sk);
788 			return -ENOTCONN;
789 		}
790 		sin->sin_port = inet->inet_dport;
791 		sin->sin_addr.s_addr = inet->inet_daddr;
792 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
793 				       CGROUP_INET4_GETPEERNAME);
794 	} else {
795 		__be32 addr = inet->inet_rcv_saddr;
796 		if (!addr)
797 			addr = inet->inet_saddr;
798 		sin->sin_port = inet->inet_sport;
799 		sin->sin_addr.s_addr = addr;
800 		BPF_CGROUP_RUN_SA_PROG(sk, (struct sockaddr *)sin,
801 				       CGROUP_INET4_GETSOCKNAME);
802 	}
803 	release_sock(sk);
804 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
805 	return sizeof(*sin);
806 }
807 EXPORT_SYMBOL(inet_getname);
808 
809 int inet_send_prepare(struct sock *sk)
810 {
811 	sock_rps_record_flow(sk);
812 
813 	/* We may need to bind the socket. */
814 	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
815 	    inet_autobind(sk))
816 		return -EAGAIN;
817 
818 	return 0;
819 }
820 EXPORT_SYMBOL_GPL(inet_send_prepare);
821 
822 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
823 {
824 	struct sock *sk = sock->sk;
825 
826 	if (unlikely(inet_send_prepare(sk)))
827 		return -EAGAIN;
828 
829 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
830 			       sk, msg, size);
831 }
832 EXPORT_SYMBOL(inet_sendmsg);
833 
834 void inet_splice_eof(struct socket *sock)
835 {
836 	const struct proto *prot;
837 	struct sock *sk = sock->sk;
838 
839 	if (unlikely(inet_send_prepare(sk)))
840 		return;
841 
842 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
843 	prot = READ_ONCE(sk->sk_prot);
844 	if (prot->splice_eof)
845 		prot->splice_eof(sock);
846 }
847 EXPORT_SYMBOL_GPL(inet_splice_eof);
848 
849 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
850 		      size_t size, int flags)
851 {
852 	struct sock *sk = sock->sk;
853 	const struct proto *prot;
854 
855 	if (unlikely(inet_send_prepare(sk)))
856 		return -EAGAIN;
857 
858 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
859 	prot = READ_ONCE(sk->sk_prot);
860 	if (prot->sendpage)
861 		return prot->sendpage(sk, page, offset, size, flags);
862 	return sock_no_sendpage(sock, page, offset, size, flags);
863 }
864 EXPORT_SYMBOL(inet_sendpage);
865 
866 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
867 					  size_t, int, int *));
868 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
869 		 int flags)
870 {
871 	struct sock *sk = sock->sk;
872 	int addr_len = 0;
873 	int err;
874 
875 	if (likely(!(flags & MSG_ERRQUEUE)))
876 		sock_rps_record_flow(sk);
877 
878 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
879 			      sk, msg, size, flags, &addr_len);
880 	if (err >= 0)
881 		msg->msg_namelen = addr_len;
882 	return err;
883 }
884 EXPORT_SYMBOL(inet_recvmsg);
885 
886 int inet_shutdown(struct socket *sock, int how)
887 {
888 	struct sock *sk = sock->sk;
889 	int err = 0;
890 
891 	/* This should really check to make sure
892 	 * the socket is a TCP socket. (WHY AC...)
893 	 */
894 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
895 		       1->2 bit 2 snds.
896 		       2->3 */
897 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
898 		return -EINVAL;
899 
900 	lock_sock(sk);
901 	if (sock->state == SS_CONNECTING) {
902 		if ((1 << sk->sk_state) &
903 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
904 			sock->state = SS_DISCONNECTING;
905 		else
906 			sock->state = SS_CONNECTED;
907 	}
908 
909 	switch (sk->sk_state) {
910 	case TCP_CLOSE:
911 		err = -ENOTCONN;
912 		/* Hack to wake up other listeners, who can poll for
913 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
914 		fallthrough;
915 	default:
916 		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
917 		if (sk->sk_prot->shutdown)
918 			sk->sk_prot->shutdown(sk, how);
919 		break;
920 
921 	/* Remaining two branches are temporary solution for missing
922 	 * close() in multithreaded environment. It is _not_ a good idea,
923 	 * but we have no choice until close() is repaired at VFS level.
924 	 */
925 	case TCP_LISTEN:
926 		if (!(how & RCV_SHUTDOWN))
927 			break;
928 		fallthrough;
929 	case TCP_SYN_SENT:
930 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
931 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
932 		break;
933 	}
934 
935 	/* Wake up anyone sleeping in poll. */
936 	sk->sk_state_change(sk);
937 	release_sock(sk);
938 	return err;
939 }
940 EXPORT_SYMBOL(inet_shutdown);
941 
942 /*
943  *	ioctl() calls you can issue on an INET socket. Most of these are
944  *	device configuration and stuff and very rarely used. Some ioctls
945  *	pass on to the socket itself.
946  *
947  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
948  *	loads the devconfigure module does its configuring and unloads it.
949  *	There's a good 20K of config code hanging around the kernel.
950  */
951 
952 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
953 {
954 	struct sock *sk = sock->sk;
955 	int err = 0;
956 	struct net *net = sock_net(sk);
957 	void __user *p = (void __user *)arg;
958 	struct ifreq ifr;
959 	struct rtentry rt;
960 
961 	switch (cmd) {
962 	case SIOCADDRT:
963 	case SIOCDELRT:
964 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
965 			return -EFAULT;
966 		err = ip_rt_ioctl(net, cmd, &rt);
967 		break;
968 	case SIOCRTMSG:
969 		err = -EINVAL;
970 		break;
971 	case SIOCDARP:
972 	case SIOCGARP:
973 	case SIOCSARP:
974 		err = arp_ioctl(net, cmd, (void __user *)arg);
975 		break;
976 	case SIOCGIFADDR:
977 	case SIOCGIFBRDADDR:
978 	case SIOCGIFNETMASK:
979 	case SIOCGIFDSTADDR:
980 	case SIOCGIFPFLAGS:
981 		if (get_user_ifreq(&ifr, NULL, p))
982 			return -EFAULT;
983 		err = devinet_ioctl(net, cmd, &ifr);
984 		if (!err && put_user_ifreq(&ifr, p))
985 			err = -EFAULT;
986 		break;
987 
988 	case SIOCSIFADDR:
989 	case SIOCSIFBRDADDR:
990 	case SIOCSIFNETMASK:
991 	case SIOCSIFDSTADDR:
992 	case SIOCSIFPFLAGS:
993 	case SIOCSIFFLAGS:
994 		if (get_user_ifreq(&ifr, NULL, p))
995 			return -EFAULT;
996 		err = devinet_ioctl(net, cmd, &ifr);
997 		break;
998 	default:
999 		if (sk->sk_prot->ioctl)
1000 			err = sk->sk_prot->ioctl(sk, cmd, arg);
1001 		else
1002 			err = -ENOIOCTLCMD;
1003 		break;
1004 	}
1005 	return err;
1006 }
1007 EXPORT_SYMBOL(inet_ioctl);
1008 
1009 #ifdef CONFIG_COMPAT
1010 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1011 		struct compat_rtentry __user *ur)
1012 {
1013 	compat_uptr_t rtdev;
1014 	struct rtentry rt;
1015 
1016 	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1017 			3 * sizeof(struct sockaddr)) ||
1018 	    get_user(rt.rt_flags, &ur->rt_flags) ||
1019 	    get_user(rt.rt_metric, &ur->rt_metric) ||
1020 	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1021 	    get_user(rt.rt_window, &ur->rt_window) ||
1022 	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1023 	    get_user(rtdev, &ur->rt_dev))
1024 		return -EFAULT;
1025 
1026 	rt.rt_dev = compat_ptr(rtdev);
1027 	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1028 }
1029 
1030 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1031 {
1032 	void __user *argp = compat_ptr(arg);
1033 	struct sock *sk = sock->sk;
1034 
1035 	switch (cmd) {
1036 	case SIOCADDRT:
1037 	case SIOCDELRT:
1038 		return inet_compat_routing_ioctl(sk, cmd, argp);
1039 	default:
1040 		if (!sk->sk_prot->compat_ioctl)
1041 			return -ENOIOCTLCMD;
1042 		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1043 	}
1044 }
1045 #endif /* CONFIG_COMPAT */
1046 
1047 const struct proto_ops inet_stream_ops = {
1048 	.family		   = PF_INET,
1049 	.owner		   = THIS_MODULE,
1050 	.release	   = inet_release,
1051 	.bind		   = inet_bind,
1052 	.connect	   = inet_stream_connect,
1053 	.socketpair	   = sock_no_socketpair,
1054 	.accept		   = inet_accept,
1055 	.getname	   = inet_getname,
1056 	.poll		   = tcp_poll,
1057 	.ioctl		   = inet_ioctl,
1058 	.gettstamp	   = sock_gettstamp,
1059 	.listen		   = inet_listen,
1060 	.shutdown	   = inet_shutdown,
1061 	.setsockopt	   = sock_common_setsockopt,
1062 	.getsockopt	   = sock_common_getsockopt,
1063 	.sendmsg	   = inet_sendmsg,
1064 	.recvmsg	   = inet_recvmsg,
1065 #ifdef CONFIG_MMU
1066 	.mmap		   = tcp_mmap,
1067 #endif
1068 	.splice_eof	   = inet_splice_eof,
1069 	.sendpage	   = inet_sendpage,
1070 	.splice_read	   = tcp_splice_read,
1071 	.read_sock	   = tcp_read_sock,
1072 	.read_skb	   = tcp_read_skb,
1073 	.sendmsg_locked    = tcp_sendmsg_locked,
1074 	.sendpage_locked   = tcp_sendpage_locked,
1075 	.peek_len	   = tcp_peek_len,
1076 #ifdef CONFIG_COMPAT
1077 	.compat_ioctl	   = inet_compat_ioctl,
1078 #endif
1079 	.set_rcvlowat	   = tcp_set_rcvlowat,
1080 };
1081 EXPORT_SYMBOL(inet_stream_ops);
1082 
1083 const struct proto_ops inet_dgram_ops = {
1084 	.family		   = PF_INET,
1085 	.owner		   = THIS_MODULE,
1086 	.release	   = inet_release,
1087 	.bind		   = inet_bind,
1088 	.connect	   = inet_dgram_connect,
1089 	.socketpair	   = sock_no_socketpair,
1090 	.accept		   = sock_no_accept,
1091 	.getname	   = inet_getname,
1092 	.poll		   = udp_poll,
1093 	.ioctl		   = inet_ioctl,
1094 	.gettstamp	   = sock_gettstamp,
1095 	.listen		   = sock_no_listen,
1096 	.shutdown	   = inet_shutdown,
1097 	.setsockopt	   = sock_common_setsockopt,
1098 	.getsockopt	   = sock_common_getsockopt,
1099 	.sendmsg	   = inet_sendmsg,
1100 	.read_skb	   = udp_read_skb,
1101 	.recvmsg	   = inet_recvmsg,
1102 	.mmap		   = sock_no_mmap,
1103 	.splice_eof	   = inet_splice_eof,
1104 	.sendpage	   = inet_sendpage,
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 	.sendpage	   = inet_sendpage,
1137 #ifdef CONFIG_COMPAT
1138 	.compat_ioctl	   = inet_compat_ioctl,
1139 #endif
1140 };
1141 
1142 static const struct net_proto_family inet_family_ops = {
1143 	.family = PF_INET,
1144 	.create = inet_create,
1145 	.owner	= THIS_MODULE,
1146 };
1147 
1148 /* Upon startup we insert all the elements in inetsw_array[] into
1149  * the linked list inetsw.
1150  */
1151 static struct inet_protosw inetsw_array[] =
1152 {
1153 	{
1154 		.type =       SOCK_STREAM,
1155 		.protocol =   IPPROTO_TCP,
1156 		.prot =       &tcp_prot,
1157 		.ops =        &inet_stream_ops,
1158 		.flags =      INET_PROTOSW_PERMANENT |
1159 			      INET_PROTOSW_ICSK,
1160 	},
1161 
1162 	{
1163 		.type =       SOCK_DGRAM,
1164 		.protocol =   IPPROTO_UDP,
1165 		.prot =       &udp_prot,
1166 		.ops =        &inet_dgram_ops,
1167 		.flags =      INET_PROTOSW_PERMANENT,
1168        },
1169 
1170        {
1171 		.type =       SOCK_DGRAM,
1172 		.protocol =   IPPROTO_ICMP,
1173 		.prot =       &ping_prot,
1174 		.ops =        &inet_sockraw_ops,
1175 		.flags =      INET_PROTOSW_REUSE,
1176        },
1177 
1178        {
1179 	       .type =       SOCK_RAW,
1180 	       .protocol =   IPPROTO_IP,	/* wild card */
1181 	       .prot =       &raw_prot,
1182 	       .ops =        &inet_sockraw_ops,
1183 	       .flags =      INET_PROTOSW_REUSE,
1184        }
1185 };
1186 
1187 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1188 
1189 void inet_register_protosw(struct inet_protosw *p)
1190 {
1191 	struct list_head *lh;
1192 	struct inet_protosw *answer;
1193 	int protocol = p->protocol;
1194 	struct list_head *last_perm;
1195 
1196 	spin_lock_bh(&inetsw_lock);
1197 
1198 	if (p->type >= SOCK_MAX)
1199 		goto out_illegal;
1200 
1201 	/* If we are trying to override a permanent protocol, bail. */
1202 	last_perm = &inetsw[p->type];
1203 	list_for_each(lh, &inetsw[p->type]) {
1204 		answer = list_entry(lh, struct inet_protosw, list);
1205 		/* Check only the non-wild match. */
1206 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1207 			break;
1208 		if (protocol == answer->protocol)
1209 			goto out_permanent;
1210 		last_perm = lh;
1211 	}
1212 
1213 	/* Add the new entry after the last permanent entry if any, so that
1214 	 * the new entry does not override a permanent entry when matched with
1215 	 * a wild-card protocol. But it is allowed to override any existing
1216 	 * non-permanent entry.  This means that when we remove this entry, the
1217 	 * system automatically returns to the old behavior.
1218 	 */
1219 	list_add_rcu(&p->list, last_perm);
1220 out:
1221 	spin_unlock_bh(&inetsw_lock);
1222 
1223 	return;
1224 
1225 out_permanent:
1226 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1227 	goto out;
1228 
1229 out_illegal:
1230 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1231 	       p->type);
1232 	goto out;
1233 }
1234 EXPORT_SYMBOL(inet_register_protosw);
1235 
1236 void inet_unregister_protosw(struct inet_protosw *p)
1237 {
1238 	if (INET_PROTOSW_PERMANENT & p->flags) {
1239 		pr_err("Attempt to unregister permanent protocol %d\n",
1240 		       p->protocol);
1241 	} else {
1242 		spin_lock_bh(&inetsw_lock);
1243 		list_del_rcu(&p->list);
1244 		spin_unlock_bh(&inetsw_lock);
1245 
1246 		synchronize_net();
1247 	}
1248 }
1249 EXPORT_SYMBOL(inet_unregister_protosw);
1250 
1251 static int inet_sk_reselect_saddr(struct sock *sk)
1252 {
1253 	struct inet_sock *inet = inet_sk(sk);
1254 	__be32 old_saddr = inet->inet_saddr;
1255 	__be32 daddr = inet->inet_daddr;
1256 	struct flowi4 *fl4;
1257 	struct rtable *rt;
1258 	__be32 new_saddr;
1259 	struct ip_options_rcu *inet_opt;
1260 	int err;
1261 
1262 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1263 					     lockdep_sock_is_held(sk));
1264 	if (inet_opt && inet_opt->opt.srr)
1265 		daddr = inet_opt->opt.faddr;
1266 
1267 	/* Query new route. */
1268 	fl4 = &inet->cork.fl.u.ip4;
1269 	rt = ip_route_connect(fl4, daddr, 0, sk->sk_bound_dev_if,
1270 			      sk->sk_protocol, inet->inet_sport,
1271 			      inet->inet_dport, sk);
1272 	if (IS_ERR(rt))
1273 		return PTR_ERR(rt);
1274 
1275 	new_saddr = fl4->saddr;
1276 
1277 	if (new_saddr == old_saddr) {
1278 		sk_setup_caps(sk, &rt->dst);
1279 		return 0;
1280 	}
1281 
1282 	err = inet_bhash2_update_saddr(sk, &new_saddr, AF_INET);
1283 	if (err) {
1284 		ip_rt_put(rt);
1285 		return err;
1286 	}
1287 
1288 	sk_setup_caps(sk, &rt->dst);
1289 
1290 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1291 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1292 			__func__, &old_saddr, &new_saddr);
1293 	}
1294 
1295 	/*
1296 	 * XXX The only one ugly spot where we need to
1297 	 * XXX really change the sockets identity after
1298 	 * XXX it has entered the hashes. -DaveM
1299 	 *
1300 	 * Besides that, it does not check for connection
1301 	 * uniqueness. Wait for troubles.
1302 	 */
1303 	return __sk_prot_rehash(sk);
1304 }
1305 
1306 int inet_sk_rebuild_header(struct sock *sk)
1307 {
1308 	struct inet_sock *inet = inet_sk(sk);
1309 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1310 	__be32 daddr;
1311 	struct ip_options_rcu *inet_opt;
1312 	struct flowi4 *fl4;
1313 	int err;
1314 
1315 	/* Route is OK, nothing to do. */
1316 	if (rt)
1317 		return 0;
1318 
1319 	/* Reroute. */
1320 	rcu_read_lock();
1321 	inet_opt = rcu_dereference(inet->inet_opt);
1322 	daddr = inet->inet_daddr;
1323 	if (inet_opt && inet_opt->opt.srr)
1324 		daddr = inet_opt->opt.faddr;
1325 	rcu_read_unlock();
1326 	fl4 = &inet->cork.fl.u.ip4;
1327 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1328 				   inet->inet_dport, inet->inet_sport,
1329 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1330 				   sk->sk_bound_dev_if);
1331 	if (!IS_ERR(rt)) {
1332 		err = 0;
1333 		sk_setup_caps(sk, &rt->dst);
1334 	} else {
1335 		err = PTR_ERR(rt);
1336 
1337 		/* Routing failed... */
1338 		sk->sk_route_caps = 0;
1339 		/*
1340 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1341 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1342 		 */
1343 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1344 		    sk->sk_state != TCP_SYN_SENT ||
1345 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1346 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1347 			WRITE_ONCE(sk->sk_err_soft, -err);
1348 	}
1349 
1350 	return err;
1351 }
1352 EXPORT_SYMBOL(inet_sk_rebuild_header);
1353 
1354 void inet_sk_set_state(struct sock *sk, int state)
1355 {
1356 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1357 	sk->sk_state = state;
1358 }
1359 EXPORT_SYMBOL(inet_sk_set_state);
1360 
1361 void inet_sk_state_store(struct sock *sk, int newstate)
1362 {
1363 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1364 	smp_store_release(&sk->sk_state, newstate);
1365 }
1366 
1367 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1368 				 netdev_features_t features)
1369 {
1370 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1371 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1372 	const struct net_offload *ops;
1373 	unsigned int offset = 0;
1374 	struct iphdr *iph;
1375 	int proto, tot_len;
1376 	int nhoff;
1377 	int ihl;
1378 	int id;
1379 
1380 	skb_reset_network_header(skb);
1381 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1382 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1383 		goto out;
1384 
1385 	iph = ip_hdr(skb);
1386 	ihl = iph->ihl * 4;
1387 	if (ihl < sizeof(*iph))
1388 		goto out;
1389 
1390 	id = ntohs(iph->id);
1391 	proto = iph->protocol;
1392 
1393 	/* Warning: after this point, iph might be no longer valid */
1394 	if (unlikely(!pskb_may_pull(skb, ihl)))
1395 		goto out;
1396 	__skb_pull(skb, ihl);
1397 
1398 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1399 	if (encap)
1400 		features &= skb->dev->hw_enc_features;
1401 	SKB_GSO_CB(skb)->encap_level += ihl;
1402 
1403 	skb_reset_transport_header(skb);
1404 
1405 	segs = ERR_PTR(-EPROTONOSUPPORT);
1406 
1407 	if (!skb->encapsulation || encap) {
1408 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1409 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1410 
1411 		/* fixed ID is invalid if DF bit is not set */
1412 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1413 			goto out;
1414 	}
1415 
1416 	ops = rcu_dereference(inet_offloads[proto]);
1417 	if (likely(ops && ops->callbacks.gso_segment)) {
1418 		segs = ops->callbacks.gso_segment(skb, features);
1419 		if (!segs)
1420 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1421 	}
1422 
1423 	if (IS_ERR_OR_NULL(segs))
1424 		goto out;
1425 
1426 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1427 
1428 	skb = segs;
1429 	do {
1430 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1431 		if (udpfrag) {
1432 			iph->frag_off = htons(offset >> 3);
1433 			if (skb->next)
1434 				iph->frag_off |= htons(IP_MF);
1435 			offset += skb->len - nhoff - ihl;
1436 			tot_len = skb->len - nhoff;
1437 		} else if (skb_is_gso(skb)) {
1438 			if (!fixedid) {
1439 				iph->id = htons(id);
1440 				id += skb_shinfo(skb)->gso_segs;
1441 			}
1442 
1443 			if (gso_partial)
1444 				tot_len = skb_shinfo(skb)->gso_size +
1445 					  SKB_GSO_CB(skb)->data_offset +
1446 					  skb->head - (unsigned char *)iph;
1447 			else
1448 				tot_len = skb->len - nhoff;
1449 		} else {
1450 			if (!fixedid)
1451 				iph->id = htons(id++);
1452 			tot_len = skb->len - nhoff;
1453 		}
1454 		iph->tot_len = htons(tot_len);
1455 		ip_send_check(iph);
1456 		if (encap)
1457 			skb_reset_inner_headers(skb);
1458 		skb->network_header = (u8 *)iph - skb->head;
1459 		skb_reset_mac_len(skb);
1460 	} while ((skb = skb->next));
1461 
1462 out:
1463 	return segs;
1464 }
1465 
1466 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1467 					netdev_features_t features)
1468 {
1469 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1470 		return ERR_PTR(-EINVAL);
1471 
1472 	return inet_gso_segment(skb, features);
1473 }
1474 
1475 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1476 {
1477 	const struct net_offload *ops;
1478 	struct sk_buff *pp = NULL;
1479 	const struct iphdr *iph;
1480 	struct sk_buff *p;
1481 	unsigned int hlen;
1482 	unsigned int off;
1483 	unsigned int id;
1484 	int flush = 1;
1485 	int proto;
1486 
1487 	off = skb_gro_offset(skb);
1488 	hlen = off + sizeof(*iph);
1489 	iph = skb_gro_header(skb, hlen, off);
1490 	if (unlikely(!iph))
1491 		goto out;
1492 
1493 	proto = iph->protocol;
1494 
1495 	ops = rcu_dereference(inet_offloads[proto]);
1496 	if (!ops || !ops->callbacks.gro_receive)
1497 		goto out;
1498 
1499 	if (*(u8 *)iph != 0x45)
1500 		goto out;
1501 
1502 	if (ip_is_fragment(iph))
1503 		goto out;
1504 
1505 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1506 		goto out;
1507 
1508 	NAPI_GRO_CB(skb)->proto = proto;
1509 	id = ntohl(*(__be32 *)&iph->id);
1510 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1511 	id >>= 16;
1512 
1513 	list_for_each_entry(p, head, list) {
1514 		struct iphdr *iph2;
1515 		u16 flush_id;
1516 
1517 		if (!NAPI_GRO_CB(p)->same_flow)
1518 			continue;
1519 
1520 		iph2 = (struct iphdr *)(p->data + off);
1521 		/* The above works because, with the exception of the top
1522 		 * (inner most) layer, we only aggregate pkts with the same
1523 		 * hdr length so all the hdrs we'll need to verify will start
1524 		 * at the same offset.
1525 		 */
1526 		if ((iph->protocol ^ iph2->protocol) |
1527 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1528 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1529 			NAPI_GRO_CB(p)->same_flow = 0;
1530 			continue;
1531 		}
1532 
1533 		/* All fields must match except length and checksum. */
1534 		NAPI_GRO_CB(p)->flush |=
1535 			(iph->ttl ^ iph2->ttl) |
1536 			(iph->tos ^ iph2->tos) |
1537 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1538 
1539 		NAPI_GRO_CB(p)->flush |= flush;
1540 
1541 		/* We need to store of the IP ID check to be included later
1542 		 * when we can verify that this packet does in fact belong
1543 		 * to a given flow.
1544 		 */
1545 		flush_id = (u16)(id - ntohs(iph2->id));
1546 
1547 		/* This bit of code makes it much easier for us to identify
1548 		 * the cases where we are doing atomic vs non-atomic IP ID
1549 		 * checks.  Specifically an atomic check can return IP ID
1550 		 * values 0 - 0xFFFF, while a non-atomic check can only
1551 		 * return 0 or 0xFFFF.
1552 		 */
1553 		if (!NAPI_GRO_CB(p)->is_atomic ||
1554 		    !(iph->frag_off & htons(IP_DF))) {
1555 			flush_id ^= NAPI_GRO_CB(p)->count;
1556 			flush_id = flush_id ? 0xFFFF : 0;
1557 		}
1558 
1559 		/* If the previous IP ID value was based on an atomic
1560 		 * datagram we can overwrite the value and ignore it.
1561 		 */
1562 		if (NAPI_GRO_CB(skb)->is_atomic)
1563 			NAPI_GRO_CB(p)->flush_id = flush_id;
1564 		else
1565 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1566 	}
1567 
1568 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1569 	NAPI_GRO_CB(skb)->flush |= flush;
1570 	skb_set_network_header(skb, off);
1571 	/* The above will be needed by the transport layer if there is one
1572 	 * immediately following this IP hdr.
1573 	 */
1574 
1575 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1576 	 * as we already checked checksum over ipv4 header was 0
1577 	 */
1578 	skb_gro_pull(skb, sizeof(*iph));
1579 	skb_set_transport_header(skb, skb_gro_offset(skb));
1580 
1581 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1582 				       ops->callbacks.gro_receive, head, skb);
1583 
1584 out:
1585 	skb_gro_flush_final(skb, pp, flush);
1586 
1587 	return pp;
1588 }
1589 
1590 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1591 					struct sk_buff *skb)
1592 {
1593 	if (NAPI_GRO_CB(skb)->encap_mark) {
1594 		NAPI_GRO_CB(skb)->flush = 1;
1595 		return NULL;
1596 	}
1597 
1598 	NAPI_GRO_CB(skb)->encap_mark = 1;
1599 
1600 	return inet_gro_receive(head, skb);
1601 }
1602 
1603 #define SECONDS_PER_DAY	86400
1604 
1605 /* inet_current_timestamp - Return IP network timestamp
1606  *
1607  * Return milliseconds since midnight in network byte order.
1608  */
1609 __be32 inet_current_timestamp(void)
1610 {
1611 	u32 secs;
1612 	u32 msecs;
1613 	struct timespec64 ts;
1614 
1615 	ktime_get_real_ts64(&ts);
1616 
1617 	/* Get secs since midnight. */
1618 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1619 	/* Convert to msecs. */
1620 	msecs = secs * MSEC_PER_SEC;
1621 	/* Convert nsec to msec. */
1622 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1623 
1624 	/* Convert to network byte order. */
1625 	return htonl(msecs);
1626 }
1627 EXPORT_SYMBOL(inet_current_timestamp);
1628 
1629 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1630 {
1631 	if (sk->sk_family == AF_INET)
1632 		return ip_recv_error(sk, msg, len, addr_len);
1633 #if IS_ENABLED(CONFIG_IPV6)
1634 	if (sk->sk_family == AF_INET6)
1635 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1636 #endif
1637 	return -EINVAL;
1638 }
1639 
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