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1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		PF_INET protocol family socket handler.
8  *
9  * Authors:	Ross Biro
10  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11  *		Florian La Roche, <flla@stud.uni-sb.de>
12  *		Alan Cox, <A.Cox@swansea.ac.uk>
13  *
14  * Changes (see also sock.c)
15  *
16  *		piggy,
17  *		Karl Knutson	:	Socket protocol table
18  *		A.N.Kuznetsov	:	Socket death error in accept().
19  *		John Richardson :	Fix non blocking error in connect()
20  *					so sockets that fail to connect
21  *					don't return -EINPROGRESS.
22  *		Alan Cox	:	Asynchronous I/O support
23  *		Alan Cox	:	Keep correct socket pointer on sock
24  *					structures
25  *					when accept() ed
26  *		Alan Cox	:	Semantics of SO_LINGER aren't state
27  *					moved to close when you look carefully.
28  *					With this fixed and the accept bug fixed
29  *					some RPC stuff seems happier.
30  *		Niibe Yutaka	:	4.4BSD style write async I/O
31  *		Alan Cox,
32  *		Tony Gale 	:	Fixed reuse semantics.
33  *		Alan Cox	:	bind() shouldn't abort existing but dead
34  *					sockets. Stops FTP netin:.. I hope.
35  *		Alan Cox	:	bind() works correctly for RAW sockets.
36  *					Note that FreeBSD at least was broken
37  *					in this respect so be careful with
38  *					compatibility tests...
39  *		Alan Cox	:	routing cache support
40  *		Alan Cox	:	memzero the socket structure for
41  *					compactness.
42  *		Matt Day	:	nonblock connect error handler
43  *		Alan Cox	:	Allow large numbers of pending sockets
44  *					(eg for big web sites), but only if
45  *					specifically application requested.
46  *		Alan Cox	:	New buffering throughout IP. Used
47  *					dumbly.
48  *		Alan Cox	:	New buffering now used smartly.
49  *		Alan Cox	:	BSD rather than common sense
50  *					interpretation of listen.
51  *		Germano Caronni	:	Assorted small races.
52  *		Alan Cox	:	sendmsg/recvmsg basic support.
53  *		Alan Cox	:	Only sendmsg/recvmsg now supported.
54  *		Alan Cox	:	Locked down bind (see security list).
55  *		Alan Cox	:	Loosened bind a little.
56  *		Mike McLagan	:	ADD/DEL DLCI Ioctls
57  *	Willy Konynenberg	:	Transparent proxying support.
58  *		David S. Miller	:	New socket lookup architecture.
59  *					Some other random speedups.
60  *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
61  *		Andi Kleen	:	Fix inet_stream_connect TCP race.
62  */
63 
64 #define pr_fmt(fmt) "IPv4: " fmt
65 
66 #include <linux/err.h>
67 #include <linux/errno.h>
68 #include <linux/types.h>
69 #include <linux/socket.h>
70 #include <linux/in.h>
71 #include <linux/kernel.h>
72 #include <linux/kmod.h>
73 #include <linux/sched.h>
74 #include <linux/timer.h>
75 #include <linux/string.h>
76 #include <linux/sockios.h>
77 #include <linux/net.h>
78 #include <linux/capability.h>
79 #include <linux/fcntl.h>
80 #include <linux/mm.h>
81 #include <linux/interrupt.h>
82 #include <linux/stat.h>
83 #include <linux/init.h>
84 #include <linux/poll.h>
85 #include <linux/netfilter_ipv4.h>
86 #include <linux/random.h>
87 #include <linux/slab.h>
88 
89 #include <linux/uaccess.h>
90 
91 #include <linux/inet.h>
92 #include <linux/igmp.h>
93 #include <linux/inetdevice.h>
94 #include <linux/netdevice.h>
95 #include <net/checksum.h>
96 #include <net/ip.h>
97 #include <net/protocol.h>
98 #include <net/arp.h>
99 #include <net/route.h>
100 #include <net/ip_fib.h>
101 #include <net/inet_connection_sock.h>
102 #include <net/tcp.h>
103 #include <net/udp.h>
104 #include <net/udplite.h>
105 #include <net/ping.h>
106 #include <linux/skbuff.h>
107 #include <net/sock.h>
108 #include <net/raw.h>
109 #include <net/icmp.h>
110 #include <net/inet_common.h>
111 #include <net/ip_tunnels.h>
112 #include <net/xfrm.h>
113 #include <net/net_namespace.h>
114 #include <net/secure_seq.h>
115 #ifdef CONFIG_IP_MROUTE
116 #include <linux/mroute.h>
117 #endif
118 #include <net/l3mdev.h>
119 #include <net/compat.h>
120 
121 #include <trace/events/sock.h>
122 
123 /* The inetsw table contains everything that inet_create needs to
124  * build a new socket.
125  */
126 static struct list_head inetsw[SOCK_MAX];
127 static DEFINE_SPINLOCK(inetsw_lock);
128 
129 /* New destruction routine */
130 
inet_sock_destruct(struct sock * sk)131 void inet_sock_destruct(struct sock *sk)
132 {
133 	struct inet_sock *inet = inet_sk(sk);
134 
135 	__skb_queue_purge(&sk->sk_receive_queue);
136 	if (sk->sk_rx_skb_cache) {
137 		__kfree_skb(sk->sk_rx_skb_cache);
138 		sk->sk_rx_skb_cache = NULL;
139 	}
140 	__skb_queue_purge(&sk->sk_error_queue);
141 
142 	sk_mem_reclaim(sk);
143 
144 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
145 		pr_err("Attempt to release TCP socket in state %d %p\n",
146 		       sk->sk_state, sk);
147 		return;
148 	}
149 	if (!sock_flag(sk, SOCK_DEAD)) {
150 		pr_err("Attempt to release alive inet socket %p\n", sk);
151 		return;
152 	}
153 
154 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
155 	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
156 	WARN_ON(sk->sk_wmem_queued);
157 	WARN_ON(sk->sk_forward_alloc);
158 
159 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
160 	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
161 	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
162 	sk_refcnt_debug_dec(sk);
163 }
164 EXPORT_SYMBOL(inet_sock_destruct);
165 
166 /*
167  *	The routines beyond this point handle the behaviour of an AF_INET
168  *	socket object. Mostly it punts to the subprotocols of IP to do
169  *	the work.
170  */
171 
172 /*
173  *	Automatically bind an unbound socket.
174  */
175 
inet_autobind(struct sock * sk)176 static int inet_autobind(struct sock *sk)
177 {
178 	struct inet_sock *inet;
179 	/* We may need to bind the socket. */
180 	lock_sock(sk);
181 	inet = inet_sk(sk);
182 	if (!inet->inet_num) {
183 		if (sk->sk_prot->get_port(sk, 0)) {
184 			release_sock(sk);
185 			return -EAGAIN;
186 		}
187 		inet->inet_sport = htons(inet->inet_num);
188 	}
189 	release_sock(sk);
190 	return 0;
191 }
192 
193 /*
194  *	Move a socket into listening state.
195  */
inet_listen(struct socket * sock,int backlog)196 int inet_listen(struct socket *sock, int backlog)
197 {
198 	struct sock *sk = sock->sk;
199 	unsigned char old_state;
200 	int err, tcp_fastopen;
201 
202 	lock_sock(sk);
203 
204 	err = -EINVAL;
205 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
206 		goto out;
207 
208 	old_state = sk->sk_state;
209 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
210 		goto out;
211 
212 	WRITE_ONCE(sk->sk_max_ack_backlog, backlog);
213 	/* Really, if the socket is already in listen state
214 	 * we can only allow the backlog to be adjusted.
215 	 */
216 	if (old_state != TCP_LISTEN) {
217 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
218 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
219 		 * Also fastopen backlog may already been set via the option
220 		 * because the socket was in TCP_LISTEN state previously but
221 		 * was shutdown() rather than close().
222 		 */
223 		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
224 		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
225 		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
226 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
227 			fastopen_queue_tune(sk, backlog);
228 			tcp_fastopen_init_key_once(sock_net(sk));
229 		}
230 
231 		err = inet_csk_listen_start(sk, backlog);
232 		if (err)
233 			goto out;
234 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
235 	}
236 	err = 0;
237 
238 out:
239 	release_sock(sk);
240 	return err;
241 }
242 EXPORT_SYMBOL(inet_listen);
243 
244 /*
245  *	Create an inet socket.
246  */
247 
inet_create(struct net * net,struct socket * sock,int protocol,int kern)248 static int inet_create(struct net *net, struct socket *sock, int protocol,
249 		       int kern)
250 {
251 	struct sock *sk;
252 	struct inet_protosw *answer;
253 	struct inet_sock *inet;
254 	struct proto *answer_prot;
255 	unsigned char answer_flags;
256 	int try_loading_module = 0;
257 	int err;
258 
259 	if (protocol < 0 || protocol >= IPPROTO_MAX)
260 		return -EINVAL;
261 
262 	sock->state = SS_UNCONNECTED;
263 
264 	/* Look for the requested type/protocol pair. */
265 lookup_protocol:
266 	err = -ESOCKTNOSUPPORT;
267 	rcu_read_lock();
268 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
269 
270 		err = 0;
271 		/* Check the non-wild match. */
272 		if (protocol == answer->protocol) {
273 			if (protocol != IPPROTO_IP)
274 				break;
275 		} else {
276 			/* Check for the two wild cases. */
277 			if (IPPROTO_IP == protocol) {
278 				protocol = answer->protocol;
279 				break;
280 			}
281 			if (IPPROTO_IP == answer->protocol)
282 				break;
283 		}
284 		err = -EPROTONOSUPPORT;
285 	}
286 
287 	if (unlikely(err)) {
288 		if (try_loading_module < 2) {
289 			rcu_read_unlock();
290 			/*
291 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
292 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
293 			 */
294 			if (++try_loading_module == 1)
295 				request_module("net-pf-%d-proto-%d-type-%d",
296 					       PF_INET, protocol, sock->type);
297 			/*
298 			 * Fall back to generic, e.g. net-pf-2-proto-132
299 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
300 			 */
301 			else
302 				request_module("net-pf-%d-proto-%d",
303 					       PF_INET, protocol);
304 			goto lookup_protocol;
305 		} else
306 			goto out_rcu_unlock;
307 	}
308 
309 	err = -EPERM;
310 	if (sock->type == SOCK_RAW && !kern &&
311 	    !ns_capable(net->user_ns, CAP_NET_RAW))
312 		goto out_rcu_unlock;
313 
314 	sock->ops = answer->ops;
315 	answer_prot = answer->prot;
316 	answer_flags = answer->flags;
317 	rcu_read_unlock();
318 
319 	WARN_ON(!answer_prot->slab);
320 
321 	err = -ENOBUFS;
322 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
323 	if (!sk)
324 		goto out;
325 
326 	err = 0;
327 	if (INET_PROTOSW_REUSE & answer_flags)
328 		sk->sk_reuse = SK_CAN_REUSE;
329 
330 	inet = inet_sk(sk);
331 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
332 
333 	inet->nodefrag = 0;
334 
335 	if (SOCK_RAW == sock->type) {
336 		inet->inet_num = protocol;
337 		if (IPPROTO_RAW == protocol)
338 			inet->hdrincl = 1;
339 	}
340 
341 	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
342 		inet->pmtudisc = IP_PMTUDISC_DONT;
343 	else
344 		inet->pmtudisc = IP_PMTUDISC_WANT;
345 
346 	inet->inet_id = 0;
347 
348 	sock_init_data(sock, sk);
349 
350 	sk->sk_destruct	   = inet_sock_destruct;
351 	sk->sk_protocol	   = protocol;
352 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
353 
354 	inet->uc_ttl	= -1;
355 	inet->mc_loop	= 1;
356 	inet->mc_ttl	= 1;
357 	inet->mc_all	= 1;
358 	inet->mc_index	= 0;
359 	inet->mc_list	= NULL;
360 	inet->rcv_tos	= 0;
361 
362 	sk_refcnt_debug_inc(sk);
363 
364 	if (inet->inet_num) {
365 		/* It assumes that any protocol which allows
366 		 * the user to assign a number at socket
367 		 * creation time automatically
368 		 * shares.
369 		 */
370 		inet->inet_sport = htons(inet->inet_num);
371 		/* Add to protocol hash chains. */
372 		err = sk->sk_prot->hash(sk);
373 		if (err) {
374 			sk_common_release(sk);
375 			goto out;
376 		}
377 	}
378 
379 	if (sk->sk_prot->init) {
380 		err = sk->sk_prot->init(sk);
381 		if (err) {
382 			sk_common_release(sk);
383 			goto out;
384 		}
385 	}
386 
387 	if (!kern) {
388 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
389 		if (err) {
390 			sk_common_release(sk);
391 			goto out;
392 		}
393 	}
394 out:
395 	return err;
396 out_rcu_unlock:
397 	rcu_read_unlock();
398 	goto out;
399 }
400 
401 
402 /*
403  *	The peer socket should always be NULL (or else). When we call this
404  *	function we are destroying the object and from then on nobody
405  *	should refer to it.
406  */
inet_release(struct socket * sock)407 int inet_release(struct socket *sock)
408 {
409 	struct sock *sk = sock->sk;
410 
411 	if (sk) {
412 		long timeout;
413 
414 		if (!sk->sk_kern_sock)
415 			BPF_CGROUP_RUN_PROG_INET_SOCK_RELEASE(sk);
416 
417 		/* Applications forget to leave groups before exiting */
418 		ip_mc_drop_socket(sk);
419 
420 		/* If linger is set, we don't return until the close
421 		 * is complete.  Otherwise we return immediately. The
422 		 * actually closing is done the same either way.
423 		 *
424 		 * If the close is due to the process exiting, we never
425 		 * linger..
426 		 */
427 		timeout = 0;
428 		if (sock_flag(sk, SOCK_LINGER) &&
429 		    !(current->flags & PF_EXITING))
430 			timeout = sk->sk_lingertime;
431 		sk->sk_prot->close(sk, timeout);
432 		sock->sk = NULL;
433 	}
434 	return 0;
435 }
436 EXPORT_SYMBOL(inet_release);
437 
inet_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)438 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
439 {
440 	struct sock *sk = sock->sk;
441 	int err;
442 
443 	/* If the socket has its own bind function then use it. (RAW) */
444 	if (sk->sk_prot->bind) {
445 		return sk->sk_prot->bind(sk, uaddr, addr_len);
446 	}
447 	if (addr_len < sizeof(struct sockaddr_in))
448 		return -EINVAL;
449 
450 	/* BPF prog is run before any checks are done so that if the prog
451 	 * changes context in a wrong way it will be caught.
452 	 */
453 	err = BPF_CGROUP_RUN_PROG_INET4_BIND(sk, uaddr);
454 	if (err)
455 		return err;
456 
457 	return __inet_bind(sk, uaddr, addr_len, BIND_WITH_LOCK);
458 }
459 EXPORT_SYMBOL(inet_bind);
460 
__inet_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len,u32 flags)461 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
462 		u32 flags)
463 {
464 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
465 	struct inet_sock *inet = inet_sk(sk);
466 	struct net *net = sock_net(sk);
467 	unsigned short snum;
468 	int chk_addr_ret;
469 	u32 tb_id = RT_TABLE_LOCAL;
470 	int err;
471 
472 	if (addr->sin_family != AF_INET) {
473 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
474 		 * only if s_addr is INADDR_ANY.
475 		 */
476 		err = -EAFNOSUPPORT;
477 		if (addr->sin_family != AF_UNSPEC ||
478 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
479 			goto out;
480 	}
481 
482 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
483 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
484 
485 	/* Not specified by any standard per-se, however it breaks too
486 	 * many applications when removed.  It is unfortunate since
487 	 * allowing applications to make a non-local bind solves
488 	 * several problems with systems using dynamic addressing.
489 	 * (ie. your servers still start up even if your ISDN link
490 	 *  is temporarily down)
491 	 */
492 	err = -EADDRNOTAVAIL;
493 	if (!inet_can_nonlocal_bind(net, inet) &&
494 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
495 	    chk_addr_ret != RTN_LOCAL &&
496 	    chk_addr_ret != RTN_MULTICAST &&
497 	    chk_addr_ret != RTN_BROADCAST)
498 		goto out;
499 
500 	snum = ntohs(addr->sin_port);
501 	err = -EACCES;
502 	if (snum && inet_port_requires_bind_service(net, snum) &&
503 	    !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
504 		goto out;
505 
506 	/*      We keep a pair of addresses. rcv_saddr is the one
507 	 *      used by hash lookups, and saddr is used for transmit.
508 	 *
509 	 *      In the BSD API these are the same except where it
510 	 *      would be illegal to use them (multicast/broadcast) in
511 	 *      which case the sending device address is used.
512 	 */
513 	if (flags & BIND_WITH_LOCK)
514 		lock_sock(sk);
515 
516 	/* Check these errors (active socket, double bind). */
517 	err = -EINVAL;
518 	if (sk->sk_state != TCP_CLOSE || inet->inet_num)
519 		goto out_release_sock;
520 
521 	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;
522 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
523 		inet->inet_saddr = 0;  /* Use device */
524 
525 	/* Make sure we are allowed to bind here. */
526 	if (snum || !(inet->bind_address_no_port ||
527 		      (flags & BIND_FORCE_ADDRESS_NO_PORT))) {
528 		if (sk->sk_prot->get_port(sk, snum)) {
529 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
530 			err = -EADDRINUSE;
531 			goto out_release_sock;
532 		}
533 		if (!(flags & BIND_FROM_BPF)) {
534 			err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
535 			if (err) {
536 				inet->inet_saddr = inet->inet_rcv_saddr = 0;
537 				goto out_release_sock;
538 			}
539 		}
540 	}
541 
542 	if (inet->inet_rcv_saddr)
543 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
544 	if (snum)
545 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
546 	inet->inet_sport = htons(inet->inet_num);
547 	inet->inet_daddr = 0;
548 	inet->inet_dport = 0;
549 	sk_dst_reset(sk);
550 	err = 0;
551 out_release_sock:
552 	if (flags & BIND_WITH_LOCK)
553 		release_sock(sk);
554 out:
555 	return err;
556 }
557 
inet_dgram_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)558 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
559 		       int addr_len, int flags)
560 {
561 	struct sock *sk = sock->sk;
562 	const struct proto *prot;
563 	int err;
564 
565 	if (addr_len < sizeof(uaddr->sa_family))
566 		return -EINVAL;
567 
568 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
569 	prot = READ_ONCE(sk->sk_prot);
570 
571 	if (uaddr->sa_family == AF_UNSPEC)
572 		return prot->disconnect(sk, flags);
573 
574 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
575 		err = prot->pre_connect(sk, uaddr, addr_len);
576 		if (err)
577 			return err;
578 	}
579 
580 	if (data_race(!inet_sk(sk)->inet_num) && inet_autobind(sk))
581 		return -EAGAIN;
582 	return prot->connect(sk, uaddr, addr_len);
583 }
584 EXPORT_SYMBOL(inet_dgram_connect);
585 
inet_wait_for_connect(struct sock * sk,long timeo,int writebias)586 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
587 {
588 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
589 
590 	add_wait_queue(sk_sleep(sk), &wait);
591 	sk->sk_write_pending += writebias;
592 
593 	/* Basic assumption: if someone sets sk->sk_err, he _must_
594 	 * change state of the socket from TCP_SYN_*.
595 	 * Connect() does not allow to get error notifications
596 	 * without closing the socket.
597 	 */
598 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
599 		release_sock(sk);
600 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
601 		lock_sock(sk);
602 		if (signal_pending(current) || !timeo)
603 			break;
604 	}
605 	remove_wait_queue(sk_sleep(sk), &wait);
606 	sk->sk_write_pending -= writebias;
607 	return timeo;
608 }
609 
610 /*
611  *	Connect to a remote host. There is regrettably still a little
612  *	TCP 'magic' in here.
613  */
__inet_stream_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags,int is_sendmsg)614 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
615 			  int addr_len, int flags, int is_sendmsg)
616 {
617 	struct sock *sk = sock->sk;
618 	int err;
619 	long timeo;
620 
621 	/*
622 	 * uaddr can be NULL and addr_len can be 0 if:
623 	 * sk is a TCP fastopen active socket and
624 	 * TCP_FASTOPEN_CONNECT sockopt is set and
625 	 * we already have a valid cookie for this socket.
626 	 * In this case, user can call write() after connect().
627 	 * write() will invoke tcp_sendmsg_fastopen() which calls
628 	 * __inet_stream_connect().
629 	 */
630 	if (uaddr) {
631 		if (addr_len < sizeof(uaddr->sa_family))
632 			return -EINVAL;
633 
634 		if (uaddr->sa_family == AF_UNSPEC) {
635 			err = sk->sk_prot->disconnect(sk, flags);
636 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
637 			goto out;
638 		}
639 	}
640 
641 	switch (sock->state) {
642 	default:
643 		err = -EINVAL;
644 		goto out;
645 	case SS_CONNECTED:
646 		err = -EISCONN;
647 		goto out;
648 	case SS_CONNECTING:
649 		if (inet_sk(sk)->defer_connect)
650 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
651 		else
652 			err = -EALREADY;
653 		/* Fall out of switch with err, set for this state */
654 		break;
655 	case SS_UNCONNECTED:
656 		err = -EISCONN;
657 		if (sk->sk_state != TCP_CLOSE)
658 			goto out;
659 
660 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
661 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
662 			if (err)
663 				goto out;
664 		}
665 
666 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
667 		if (err < 0)
668 			goto out;
669 
670 		sock->state = SS_CONNECTING;
671 
672 		if (!err && inet_sk(sk)->defer_connect)
673 			goto out;
674 
675 		/* Just entered SS_CONNECTING state; the only
676 		 * difference is that return value in non-blocking
677 		 * case is EINPROGRESS, rather than EALREADY.
678 		 */
679 		err = -EINPROGRESS;
680 		break;
681 	}
682 
683 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
684 
685 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
686 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
687 				tcp_sk(sk)->fastopen_req &&
688 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
689 
690 		/* Error code is set above */
691 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
692 			goto out;
693 
694 		err = sock_intr_errno(timeo);
695 		if (signal_pending(current))
696 			goto out;
697 	}
698 
699 	/* Connection was closed by RST, timeout, ICMP error
700 	 * or another process disconnected us.
701 	 */
702 	if (sk->sk_state == TCP_CLOSE)
703 		goto sock_error;
704 
705 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
706 	 * and error was received after socket entered established state.
707 	 * Hence, it is handled normally after connect() return successfully.
708 	 */
709 
710 	sock->state = SS_CONNECTED;
711 	err = 0;
712 out:
713 	return err;
714 
715 sock_error:
716 	err = sock_error(sk) ? : -ECONNABORTED;
717 	sock->state = SS_UNCONNECTED;
718 	if (sk->sk_prot->disconnect(sk, flags))
719 		sock->state = SS_DISCONNECTING;
720 	goto out;
721 }
722 EXPORT_SYMBOL(__inet_stream_connect);
723 
inet_stream_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)724 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
725 			int addr_len, int flags)
726 {
727 	int err;
728 
729 	lock_sock(sock->sk);
730 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
731 	release_sock(sock->sk);
732 	return err;
733 }
734 EXPORT_SYMBOL(inet_stream_connect);
735 
736 /*
737  *	Accept a pending connection. The TCP layer now gives BSD semantics.
738  */
739 
inet_accept(struct socket * sock,struct socket * newsock,int flags,bool kern)740 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
741 		bool kern)
742 {
743 	struct sock *sk1 = sock->sk, *sk2;
744 	int err = -EINVAL;
745 
746 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
747 	sk2 = READ_ONCE(sk1->sk_prot)->accept(sk1, flags, &err, kern);
748 	if (!sk2)
749 		goto do_err;
750 
751 	lock_sock(sk2);
752 
753 	sock_rps_record_flow(sk2);
754 	WARN_ON(!((1 << sk2->sk_state) &
755 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
756 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
757 
758 	sock_graft(sk2, newsock);
759 
760 	newsock->state = SS_CONNECTED;
761 	err = 0;
762 	release_sock(sk2);
763 do_err:
764 	return err;
765 }
766 EXPORT_SYMBOL(inet_accept);
767 
768 /*
769  *	This does both peername and sockname.
770  */
inet_getname(struct socket * sock,struct sockaddr * uaddr,int peer)771 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
772 		 int peer)
773 {
774 	struct sock *sk		= sock->sk;
775 	struct inet_sock *inet	= inet_sk(sk);
776 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
777 
778 	sin->sin_family = AF_INET;
779 	if (peer) {
780 		if (!inet->inet_dport ||
781 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
782 		     peer == 1))
783 			return -ENOTCONN;
784 		sin->sin_port = inet->inet_dport;
785 		sin->sin_addr.s_addr = inet->inet_daddr;
786 	} else {
787 		__be32 addr = inet->inet_rcv_saddr;
788 		if (!addr)
789 			addr = inet->inet_saddr;
790 		sin->sin_port = inet->inet_sport;
791 		sin->sin_addr.s_addr = addr;
792 	}
793 	if (cgroup_bpf_enabled)
794 		BPF_CGROUP_RUN_SA_PROG_LOCK(sk, (struct sockaddr *)sin,
795 					    peer ? BPF_CGROUP_INET4_GETPEERNAME :
796 						   BPF_CGROUP_INET4_GETSOCKNAME,
797 					    NULL);
798 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
799 	return sizeof(*sin);
800 }
801 EXPORT_SYMBOL(inet_getname);
802 
inet_send_prepare(struct sock * sk)803 int inet_send_prepare(struct sock *sk)
804 {
805 	sock_rps_record_flow(sk);
806 
807 	/* We may need to bind the socket. */
808 	if (data_race(!inet_sk(sk)->inet_num) && !sk->sk_prot->no_autobind &&
809 	    inet_autobind(sk))
810 		return -EAGAIN;
811 
812 	return 0;
813 }
814 EXPORT_SYMBOL_GPL(inet_send_prepare);
815 
inet_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)816 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
817 {
818 	struct sock *sk = sock->sk;
819 
820 	if (unlikely(inet_send_prepare(sk)))
821 		return -EAGAIN;
822 
823 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
824 			       sk, msg, size);
825 }
826 EXPORT_SYMBOL(inet_sendmsg);
827 
inet_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)828 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
829 		      size_t size, int flags)
830 {
831 	struct sock *sk = sock->sk;
832 	const struct proto *prot;
833 
834 	if (unlikely(inet_send_prepare(sk)))
835 		return -EAGAIN;
836 
837 	/* IPV6_ADDRFORM can change sk->sk_prot under us. */
838 	prot = READ_ONCE(sk->sk_prot);
839 	if (prot->sendpage)
840 		return prot->sendpage(sk, page, offset, size, flags);
841 	return sock_no_sendpage(sock, page, offset, size, flags);
842 }
843 EXPORT_SYMBOL(inet_sendpage);
844 
845 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
846 					  size_t, int, int, int *));
inet_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)847 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
848 		 int flags)
849 {
850 	struct sock *sk = sock->sk;
851 	int addr_len = 0;
852 	int err;
853 
854 	if (likely(!(flags & MSG_ERRQUEUE)))
855 		sock_rps_record_flow(sk);
856 
857 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
858 			      sk, msg, size, flags & MSG_DONTWAIT,
859 			      flags & ~MSG_DONTWAIT, &addr_len);
860 	if (err >= 0)
861 		msg->msg_namelen = addr_len;
862 	return err;
863 }
864 EXPORT_SYMBOL(inet_recvmsg);
865 
inet_shutdown(struct socket * sock,int how)866 int inet_shutdown(struct socket *sock, int how)
867 {
868 	struct sock *sk = sock->sk;
869 	int err = 0;
870 
871 	/* This should really check to make sure
872 	 * the socket is a TCP socket. (WHY AC...)
873 	 */
874 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
875 		       1->2 bit 2 snds.
876 		       2->3 */
877 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
878 		return -EINVAL;
879 
880 	lock_sock(sk);
881 	if (sock->state == SS_CONNECTING) {
882 		if ((1 << sk->sk_state) &
883 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
884 			sock->state = SS_DISCONNECTING;
885 		else
886 			sock->state = SS_CONNECTED;
887 	}
888 
889 	switch (sk->sk_state) {
890 	case TCP_CLOSE:
891 		err = -ENOTCONN;
892 		/* Hack to wake up other listeners, who can poll for
893 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
894 		fallthrough;
895 	default:
896 		sk->sk_shutdown |= how;
897 		if (sk->sk_prot->shutdown)
898 			sk->sk_prot->shutdown(sk, how);
899 		break;
900 
901 	/* Remaining two branches are temporary solution for missing
902 	 * close() in multithreaded environment. It is _not_ a good idea,
903 	 * but we have no choice until close() is repaired at VFS level.
904 	 */
905 	case TCP_LISTEN:
906 		if (!(how & RCV_SHUTDOWN))
907 			break;
908 		fallthrough;
909 	case TCP_SYN_SENT:
910 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
911 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
912 		break;
913 	}
914 
915 	/* Wake up anyone sleeping in poll. */
916 	sk->sk_state_change(sk);
917 	release_sock(sk);
918 	return err;
919 }
920 EXPORT_SYMBOL(inet_shutdown);
921 
922 /*
923  *	ioctl() calls you can issue on an INET socket. Most of these are
924  *	device configuration and stuff and very rarely used. Some ioctls
925  *	pass on to the socket itself.
926  *
927  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
928  *	loads the devconfigure module does its configuring and unloads it.
929  *	There's a good 20K of config code hanging around the kernel.
930  */
931 
inet_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)932 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
933 {
934 	struct sock *sk = sock->sk;
935 	int err = 0;
936 	struct net *net = sock_net(sk);
937 	void __user *p = (void __user *)arg;
938 	struct ifreq ifr;
939 	struct rtentry rt;
940 
941 	switch (cmd) {
942 	case SIOCADDRT:
943 	case SIOCDELRT:
944 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
945 			return -EFAULT;
946 		err = ip_rt_ioctl(net, cmd, &rt);
947 		break;
948 	case SIOCRTMSG:
949 		err = -EINVAL;
950 		break;
951 	case SIOCDARP:
952 	case SIOCGARP:
953 	case SIOCSARP:
954 		err = arp_ioctl(net, cmd, (void __user *)arg);
955 		break;
956 	case SIOCGIFADDR:
957 	case SIOCGIFBRDADDR:
958 	case SIOCGIFNETMASK:
959 	case SIOCGIFDSTADDR:
960 	case SIOCGIFPFLAGS:
961 		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
962 			return -EFAULT;
963 		err = devinet_ioctl(net, cmd, &ifr);
964 		if (!err && copy_to_user(p, &ifr, sizeof(struct ifreq)))
965 			err = -EFAULT;
966 		break;
967 
968 	case SIOCSIFADDR:
969 	case SIOCSIFBRDADDR:
970 	case SIOCSIFNETMASK:
971 	case SIOCSIFDSTADDR:
972 	case SIOCSIFPFLAGS:
973 	case SIOCSIFFLAGS:
974 		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
975 			return -EFAULT;
976 		err = devinet_ioctl(net, cmd, &ifr);
977 		break;
978 	default:
979 		if (sk->sk_prot->ioctl)
980 			err = sk->sk_prot->ioctl(sk, cmd, arg);
981 		else
982 			err = -ENOIOCTLCMD;
983 		break;
984 	}
985 	return err;
986 }
987 EXPORT_SYMBOL(inet_ioctl);
988 
989 #ifdef CONFIG_COMPAT
inet_compat_routing_ioctl(struct sock * sk,unsigned int cmd,struct compat_rtentry __user * ur)990 static int inet_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
991 		struct compat_rtentry __user *ur)
992 {
993 	compat_uptr_t rtdev;
994 	struct rtentry rt;
995 
996 	if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
997 			3 * sizeof(struct sockaddr)) ||
998 	    get_user(rt.rt_flags, &ur->rt_flags) ||
999 	    get_user(rt.rt_metric, &ur->rt_metric) ||
1000 	    get_user(rt.rt_mtu, &ur->rt_mtu) ||
1001 	    get_user(rt.rt_window, &ur->rt_window) ||
1002 	    get_user(rt.rt_irtt, &ur->rt_irtt) ||
1003 	    get_user(rtdev, &ur->rt_dev))
1004 		return -EFAULT;
1005 
1006 	rt.rt_dev = compat_ptr(rtdev);
1007 	return ip_rt_ioctl(sock_net(sk), cmd, &rt);
1008 }
1009 
inet_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)1010 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1011 {
1012 	void __user *argp = compat_ptr(arg);
1013 	struct sock *sk = sock->sk;
1014 
1015 	switch (cmd) {
1016 	case SIOCADDRT:
1017 	case SIOCDELRT:
1018 		return inet_compat_routing_ioctl(sk, cmd, argp);
1019 	default:
1020 		if (!sk->sk_prot->compat_ioctl)
1021 			return -ENOIOCTLCMD;
1022 		return sk->sk_prot->compat_ioctl(sk, cmd, arg);
1023 	}
1024 }
1025 #endif /* CONFIG_COMPAT */
1026 
1027 const struct proto_ops inet_stream_ops = {
1028 	.family		   = PF_INET,
1029 	.owner		   = THIS_MODULE,
1030 	.release	   = inet_release,
1031 	.bind		   = inet_bind,
1032 	.connect	   = inet_stream_connect,
1033 	.socketpair	   = sock_no_socketpair,
1034 	.accept		   = inet_accept,
1035 	.getname	   = inet_getname,
1036 	.poll		   = tcp_poll,
1037 	.ioctl		   = inet_ioctl,
1038 	.gettstamp	   = sock_gettstamp,
1039 	.listen		   = inet_listen,
1040 	.shutdown	   = inet_shutdown,
1041 	.setsockopt	   = sock_common_setsockopt,
1042 	.getsockopt	   = sock_common_getsockopt,
1043 	.sendmsg	   = inet_sendmsg,
1044 	.recvmsg	   = inet_recvmsg,
1045 #ifdef CONFIG_MMU
1046 	.mmap		   = tcp_mmap,
1047 #endif
1048 	.sendpage	   = inet_sendpage,
1049 	.splice_read	   = tcp_splice_read,
1050 	.read_sock	   = tcp_read_sock,
1051 	.sendmsg_locked    = tcp_sendmsg_locked,
1052 	.sendpage_locked   = tcp_sendpage_locked,
1053 	.peek_len	   = tcp_peek_len,
1054 #ifdef CONFIG_COMPAT
1055 	.compat_ioctl	   = inet_compat_ioctl,
1056 #endif
1057 	.set_rcvlowat	   = tcp_set_rcvlowat,
1058 };
1059 EXPORT_SYMBOL(inet_stream_ops);
1060 
1061 const struct proto_ops inet_dgram_ops = {
1062 	.family		   = PF_INET,
1063 	.owner		   = THIS_MODULE,
1064 	.release	   = inet_release,
1065 	.bind		   = inet_bind,
1066 	.connect	   = inet_dgram_connect,
1067 	.socketpair	   = sock_no_socketpair,
1068 	.accept		   = sock_no_accept,
1069 	.getname	   = inet_getname,
1070 	.poll		   = udp_poll,
1071 	.ioctl		   = inet_ioctl,
1072 	.gettstamp	   = sock_gettstamp,
1073 	.listen		   = sock_no_listen,
1074 	.shutdown	   = inet_shutdown,
1075 	.setsockopt	   = sock_common_setsockopt,
1076 	.getsockopt	   = sock_common_getsockopt,
1077 	.sendmsg	   = inet_sendmsg,
1078 	.recvmsg	   = inet_recvmsg,
1079 	.mmap		   = sock_no_mmap,
1080 	.sendpage	   = inet_sendpage,
1081 	.set_peek_off	   = sk_set_peek_off,
1082 #ifdef CONFIG_COMPAT
1083 	.compat_ioctl	   = inet_compat_ioctl,
1084 #endif
1085 };
1086 EXPORT_SYMBOL(inet_dgram_ops);
1087 
1088 /*
1089  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1090  * udp_poll
1091  */
1092 static const struct proto_ops inet_sockraw_ops = {
1093 	.family		   = PF_INET,
1094 	.owner		   = THIS_MODULE,
1095 	.release	   = inet_release,
1096 	.bind		   = inet_bind,
1097 	.connect	   = inet_dgram_connect,
1098 	.socketpair	   = sock_no_socketpair,
1099 	.accept		   = sock_no_accept,
1100 	.getname	   = inet_getname,
1101 	.poll		   = datagram_poll,
1102 	.ioctl		   = inet_ioctl,
1103 	.gettstamp	   = sock_gettstamp,
1104 	.listen		   = sock_no_listen,
1105 	.shutdown	   = inet_shutdown,
1106 	.setsockopt	   = sock_common_setsockopt,
1107 	.getsockopt	   = sock_common_getsockopt,
1108 	.sendmsg	   = inet_sendmsg,
1109 	.recvmsg	   = inet_recvmsg,
1110 	.mmap		   = sock_no_mmap,
1111 	.sendpage	   = inet_sendpage,
1112 #ifdef CONFIG_COMPAT
1113 	.compat_ioctl	   = inet_compat_ioctl,
1114 #endif
1115 };
1116 
1117 static const struct net_proto_family inet_family_ops = {
1118 	.family = PF_INET,
1119 	.create = inet_create,
1120 	.owner	= THIS_MODULE,
1121 };
1122 
1123 /* Upon startup we insert all the elements in inetsw_array[] into
1124  * the linked list inetsw.
1125  */
1126 static struct inet_protosw inetsw_array[] =
1127 {
1128 	{
1129 		.type =       SOCK_STREAM,
1130 		.protocol =   IPPROTO_TCP,
1131 		.prot =       &tcp_prot,
1132 		.ops =        &inet_stream_ops,
1133 		.flags =      INET_PROTOSW_PERMANENT |
1134 			      INET_PROTOSW_ICSK,
1135 	},
1136 
1137 	{
1138 		.type =       SOCK_DGRAM,
1139 		.protocol =   IPPROTO_UDP,
1140 		.prot =       &udp_prot,
1141 		.ops =        &inet_dgram_ops,
1142 		.flags =      INET_PROTOSW_PERMANENT,
1143        },
1144 
1145        {
1146 		.type =       SOCK_DGRAM,
1147 		.protocol =   IPPROTO_ICMP,
1148 		.prot =       &ping_prot,
1149 		.ops =        &inet_sockraw_ops,
1150 		.flags =      INET_PROTOSW_REUSE,
1151        },
1152 
1153        {
1154 	       .type =       SOCK_RAW,
1155 	       .protocol =   IPPROTO_IP,	/* wild card */
1156 	       .prot =       &raw_prot,
1157 	       .ops =        &inet_sockraw_ops,
1158 	       .flags =      INET_PROTOSW_REUSE,
1159        }
1160 };
1161 
1162 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1163 
inet_register_protosw(struct inet_protosw * p)1164 void inet_register_protosw(struct inet_protosw *p)
1165 {
1166 	struct list_head *lh;
1167 	struct inet_protosw *answer;
1168 	int protocol = p->protocol;
1169 	struct list_head *last_perm;
1170 
1171 	spin_lock_bh(&inetsw_lock);
1172 
1173 	if (p->type >= SOCK_MAX)
1174 		goto out_illegal;
1175 
1176 	/* If we are trying to override a permanent protocol, bail. */
1177 	last_perm = &inetsw[p->type];
1178 	list_for_each(lh, &inetsw[p->type]) {
1179 		answer = list_entry(lh, struct inet_protosw, list);
1180 		/* Check only the non-wild match. */
1181 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1182 			break;
1183 		if (protocol == answer->protocol)
1184 			goto out_permanent;
1185 		last_perm = lh;
1186 	}
1187 
1188 	/* Add the new entry after the last permanent entry if any, so that
1189 	 * the new entry does not override a permanent entry when matched with
1190 	 * a wild-card protocol. But it is allowed to override any existing
1191 	 * non-permanent entry.  This means that when we remove this entry, the
1192 	 * system automatically returns to the old behavior.
1193 	 */
1194 	list_add_rcu(&p->list, last_perm);
1195 out:
1196 	spin_unlock_bh(&inetsw_lock);
1197 
1198 	return;
1199 
1200 out_permanent:
1201 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1202 	goto out;
1203 
1204 out_illegal:
1205 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1206 	       p->type);
1207 	goto out;
1208 }
1209 EXPORT_SYMBOL(inet_register_protosw);
1210 
inet_unregister_protosw(struct inet_protosw * p)1211 void inet_unregister_protosw(struct inet_protosw *p)
1212 {
1213 	if (INET_PROTOSW_PERMANENT & p->flags) {
1214 		pr_err("Attempt to unregister permanent protocol %d\n",
1215 		       p->protocol);
1216 	} else {
1217 		spin_lock_bh(&inetsw_lock);
1218 		list_del_rcu(&p->list);
1219 		spin_unlock_bh(&inetsw_lock);
1220 
1221 		synchronize_net();
1222 	}
1223 }
1224 EXPORT_SYMBOL(inet_unregister_protosw);
1225 
inet_sk_reselect_saddr(struct sock * sk)1226 static int inet_sk_reselect_saddr(struct sock *sk)
1227 {
1228 	struct inet_sock *inet = inet_sk(sk);
1229 	__be32 old_saddr = inet->inet_saddr;
1230 	__be32 daddr = inet->inet_daddr;
1231 	struct flowi4 *fl4;
1232 	struct rtable *rt;
1233 	__be32 new_saddr;
1234 	struct ip_options_rcu *inet_opt;
1235 
1236 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1237 					     lockdep_sock_is_held(sk));
1238 	if (inet_opt && inet_opt->opt.srr)
1239 		daddr = inet_opt->opt.faddr;
1240 
1241 	/* Query new route. */
1242 	fl4 = &inet->cork.fl.u.ip4;
1243 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1244 			      sk->sk_bound_dev_if, sk->sk_protocol,
1245 			      inet->inet_sport, inet->inet_dport, sk);
1246 	if (IS_ERR(rt))
1247 		return PTR_ERR(rt);
1248 
1249 	sk_setup_caps(sk, &rt->dst);
1250 
1251 	new_saddr = fl4->saddr;
1252 
1253 	if (new_saddr == old_saddr)
1254 		return 0;
1255 
1256 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1257 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1258 			__func__, &old_saddr, &new_saddr);
1259 	}
1260 
1261 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1262 
1263 	/*
1264 	 * XXX The only one ugly spot where we need to
1265 	 * XXX really change the sockets identity after
1266 	 * XXX it has entered the hashes. -DaveM
1267 	 *
1268 	 * Besides that, it does not check for connection
1269 	 * uniqueness. Wait for troubles.
1270 	 */
1271 	return __sk_prot_rehash(sk);
1272 }
1273 
inet_sk_rebuild_header(struct sock * sk)1274 int inet_sk_rebuild_header(struct sock *sk)
1275 {
1276 	struct inet_sock *inet = inet_sk(sk);
1277 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1278 	__be32 daddr;
1279 	struct ip_options_rcu *inet_opt;
1280 	struct flowi4 *fl4;
1281 	int err;
1282 
1283 	/* Route is OK, nothing to do. */
1284 	if (rt)
1285 		return 0;
1286 
1287 	/* Reroute. */
1288 	rcu_read_lock();
1289 	inet_opt = rcu_dereference(inet->inet_opt);
1290 	daddr = inet->inet_daddr;
1291 	if (inet_opt && inet_opt->opt.srr)
1292 		daddr = inet_opt->opt.faddr;
1293 	rcu_read_unlock();
1294 	fl4 = &inet->cork.fl.u.ip4;
1295 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1296 				   inet->inet_dport, inet->inet_sport,
1297 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1298 				   sk->sk_bound_dev_if);
1299 	if (!IS_ERR(rt)) {
1300 		err = 0;
1301 		sk_setup_caps(sk, &rt->dst);
1302 	} else {
1303 		err = PTR_ERR(rt);
1304 
1305 		/* Routing failed... */
1306 		sk->sk_route_caps = 0;
1307 		/*
1308 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1309 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1310 		 */
1311 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1312 		    sk->sk_state != TCP_SYN_SENT ||
1313 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1314 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1315 			sk->sk_err_soft = -err;
1316 	}
1317 
1318 	return err;
1319 }
1320 EXPORT_SYMBOL(inet_sk_rebuild_header);
1321 
inet_sk_set_state(struct sock * sk,int state)1322 void inet_sk_set_state(struct sock *sk, int state)
1323 {
1324 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1325 	sk->sk_state = state;
1326 }
1327 EXPORT_SYMBOL(inet_sk_set_state);
1328 
inet_sk_state_store(struct sock * sk,int newstate)1329 void inet_sk_state_store(struct sock *sk, int newstate)
1330 {
1331 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1332 	smp_store_release(&sk->sk_state, newstate);
1333 }
1334 
inet_gso_segment(struct sk_buff * skb,netdev_features_t features)1335 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1336 				 netdev_features_t features)
1337 {
1338 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1339 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1340 	const struct net_offload *ops;
1341 	unsigned int offset = 0;
1342 	struct iphdr *iph;
1343 	int proto, tot_len;
1344 	int nhoff;
1345 	int ihl;
1346 	int id;
1347 
1348 	skb_reset_network_header(skb);
1349 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1350 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1351 		goto out;
1352 
1353 	iph = ip_hdr(skb);
1354 	ihl = iph->ihl * 4;
1355 	if (ihl < sizeof(*iph))
1356 		goto out;
1357 
1358 	id = ntohs(iph->id);
1359 	proto = iph->protocol;
1360 
1361 	/* Warning: after this point, iph might be no longer valid */
1362 	if (unlikely(!pskb_may_pull(skb, ihl)))
1363 		goto out;
1364 	__skb_pull(skb, ihl);
1365 
1366 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1367 	if (encap)
1368 		features &= skb->dev->hw_enc_features;
1369 	SKB_GSO_CB(skb)->encap_level += ihl;
1370 
1371 	skb_reset_transport_header(skb);
1372 
1373 	segs = ERR_PTR(-EPROTONOSUPPORT);
1374 
1375 	if (!skb->encapsulation || encap) {
1376 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1377 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1378 
1379 		/* fixed ID is invalid if DF bit is not set */
1380 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1381 			goto out;
1382 	}
1383 
1384 	ops = rcu_dereference(inet_offloads[proto]);
1385 	if (likely(ops && ops->callbacks.gso_segment)) {
1386 		segs = ops->callbacks.gso_segment(skb, features);
1387 		if (!segs)
1388 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1389 	}
1390 
1391 	if (IS_ERR_OR_NULL(segs))
1392 		goto out;
1393 
1394 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1395 
1396 	skb = segs;
1397 	do {
1398 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1399 		if (udpfrag) {
1400 			iph->frag_off = htons(offset >> 3);
1401 			if (skb->next)
1402 				iph->frag_off |= htons(IP_MF);
1403 			offset += skb->len - nhoff - ihl;
1404 			tot_len = skb->len - nhoff;
1405 		} else if (skb_is_gso(skb)) {
1406 			if (!fixedid) {
1407 				iph->id = htons(id);
1408 				id += skb_shinfo(skb)->gso_segs;
1409 			}
1410 
1411 			if (gso_partial)
1412 				tot_len = skb_shinfo(skb)->gso_size +
1413 					  SKB_GSO_CB(skb)->data_offset +
1414 					  skb->head - (unsigned char *)iph;
1415 			else
1416 				tot_len = skb->len - nhoff;
1417 		} else {
1418 			if (!fixedid)
1419 				iph->id = htons(id++);
1420 			tot_len = skb->len - nhoff;
1421 		}
1422 		iph->tot_len = htons(tot_len);
1423 		ip_send_check(iph);
1424 		if (encap)
1425 			skb_reset_inner_headers(skb);
1426 		skb->network_header = (u8 *)iph - skb->head;
1427 		skb_reset_mac_len(skb);
1428 	} while ((skb = skb->next));
1429 
1430 out:
1431 	return segs;
1432 }
1433 EXPORT_SYMBOL(inet_gso_segment);
1434 
ipip_gso_segment(struct sk_buff * skb,netdev_features_t features)1435 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1436 					netdev_features_t features)
1437 {
1438 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1439 		return ERR_PTR(-EINVAL);
1440 
1441 	return inet_gso_segment(skb, features);
1442 }
1443 
inet_gro_receive(struct list_head * head,struct sk_buff * skb)1444 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1445 {
1446 	const struct net_offload *ops;
1447 	struct sk_buff *pp = NULL;
1448 	const struct iphdr *iph;
1449 	struct sk_buff *p;
1450 	unsigned int hlen;
1451 	unsigned int off;
1452 	unsigned int id;
1453 	int flush = 1;
1454 	int proto;
1455 
1456 	off = skb_gro_offset(skb);
1457 	hlen = off + sizeof(*iph);
1458 	iph = skb_gro_header_fast(skb, off);
1459 	if (skb_gro_header_hard(skb, hlen)) {
1460 		iph = skb_gro_header_slow(skb, hlen, off);
1461 		if (unlikely(!iph))
1462 			goto out;
1463 	}
1464 
1465 	proto = iph->protocol;
1466 
1467 	rcu_read_lock();
1468 	ops = rcu_dereference(inet_offloads[proto]);
1469 	if (!ops || !ops->callbacks.gro_receive)
1470 		goto out_unlock;
1471 
1472 	if (*(u8 *)iph != 0x45)
1473 		goto out_unlock;
1474 
1475 	if (ip_is_fragment(iph))
1476 		goto out_unlock;
1477 
1478 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1479 		goto out_unlock;
1480 
1481 	id = ntohl(*(__be32 *)&iph->id);
1482 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1483 	id >>= 16;
1484 
1485 	list_for_each_entry(p, head, list) {
1486 		struct iphdr *iph2;
1487 		u16 flush_id;
1488 
1489 		if (!NAPI_GRO_CB(p)->same_flow)
1490 			continue;
1491 
1492 		iph2 = (struct iphdr *)(p->data + off);
1493 		/* The above works because, with the exception of the top
1494 		 * (inner most) layer, we only aggregate pkts with the same
1495 		 * hdr length so all the hdrs we'll need to verify will start
1496 		 * at the same offset.
1497 		 */
1498 		if ((iph->protocol ^ iph2->protocol) |
1499 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1500 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1501 			NAPI_GRO_CB(p)->same_flow = 0;
1502 			continue;
1503 		}
1504 
1505 		/* All fields must match except length and checksum. */
1506 		NAPI_GRO_CB(p)->flush |=
1507 			(iph->ttl ^ iph2->ttl) |
1508 			(iph->tos ^ iph2->tos) |
1509 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1510 
1511 		NAPI_GRO_CB(p)->flush |= flush;
1512 
1513 		/* We need to store of the IP ID check to be included later
1514 		 * when we can verify that this packet does in fact belong
1515 		 * to a given flow.
1516 		 */
1517 		flush_id = (u16)(id - ntohs(iph2->id));
1518 
1519 		/* This bit of code makes it much easier for us to identify
1520 		 * the cases where we are doing atomic vs non-atomic IP ID
1521 		 * checks.  Specifically an atomic check can return IP ID
1522 		 * values 0 - 0xFFFF, while a non-atomic check can only
1523 		 * return 0 or 0xFFFF.
1524 		 */
1525 		if (!NAPI_GRO_CB(p)->is_atomic ||
1526 		    !(iph->frag_off & htons(IP_DF))) {
1527 			flush_id ^= NAPI_GRO_CB(p)->count;
1528 			flush_id = flush_id ? 0xFFFF : 0;
1529 		}
1530 
1531 		/* If the previous IP ID value was based on an atomic
1532 		 * datagram we can overwrite the value and ignore it.
1533 		 */
1534 		if (NAPI_GRO_CB(skb)->is_atomic)
1535 			NAPI_GRO_CB(p)->flush_id = flush_id;
1536 		else
1537 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1538 	}
1539 
1540 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1541 	NAPI_GRO_CB(skb)->flush |= flush;
1542 	skb_set_network_header(skb, off);
1543 	/* The above will be needed by the transport layer if there is one
1544 	 * immediately following this IP hdr.
1545 	 */
1546 
1547 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1548 	 * as we already checked checksum over ipv4 header was 0
1549 	 */
1550 	skb_gro_pull(skb, sizeof(*iph));
1551 	skb_set_transport_header(skb, skb_gro_offset(skb));
1552 
1553 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1554 				       ops->callbacks.gro_receive, head, skb);
1555 
1556 out_unlock:
1557 	rcu_read_unlock();
1558 
1559 out:
1560 	skb_gro_flush_final(skb, pp, flush);
1561 
1562 	return pp;
1563 }
1564 EXPORT_SYMBOL(inet_gro_receive);
1565 
ipip_gro_receive(struct list_head * head,struct sk_buff * skb)1566 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1567 					struct sk_buff *skb)
1568 {
1569 	if (NAPI_GRO_CB(skb)->encap_mark) {
1570 		NAPI_GRO_CB(skb)->flush = 1;
1571 		return NULL;
1572 	}
1573 
1574 	NAPI_GRO_CB(skb)->encap_mark = 1;
1575 
1576 	return inet_gro_receive(head, skb);
1577 }
1578 
1579 #define SECONDS_PER_DAY	86400
1580 
1581 /* inet_current_timestamp - Return IP network timestamp
1582  *
1583  * Return milliseconds since midnight in network byte order.
1584  */
inet_current_timestamp(void)1585 __be32 inet_current_timestamp(void)
1586 {
1587 	u32 secs;
1588 	u32 msecs;
1589 	struct timespec64 ts;
1590 
1591 	ktime_get_real_ts64(&ts);
1592 
1593 	/* Get secs since midnight. */
1594 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1595 	/* Convert to msecs. */
1596 	msecs = secs * MSEC_PER_SEC;
1597 	/* Convert nsec to msec. */
1598 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1599 
1600 	/* Convert to network byte order. */
1601 	return htonl(msecs);
1602 }
1603 EXPORT_SYMBOL(inet_current_timestamp);
1604 
inet_recv_error(struct sock * sk,struct msghdr * msg,int len,int * addr_len)1605 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1606 {
1607 	if (sk->sk_family == AF_INET)
1608 		return ip_recv_error(sk, msg, len, addr_len);
1609 #if IS_ENABLED(CONFIG_IPV6)
1610 	if (sk->sk_family == AF_INET6)
1611 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1612 #endif
1613 	return -EINVAL;
1614 }
1615 
inet_gro_complete(struct sk_buff * skb,int nhoff)1616 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1617 {
1618 	__be16 newlen = htons(skb->len - nhoff);
1619 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1620 	const struct net_offload *ops;
1621 	int proto = iph->protocol;
1622 	int err = -ENOSYS;
1623 
1624 	if (skb->encapsulation) {
1625 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1626 		skb_set_inner_network_header(skb, nhoff);
1627 	}
1628 
1629 	csum_replace2(&iph->check, iph->tot_len, newlen);
1630 	iph->tot_len = newlen;
1631 
1632 	rcu_read_lock();
1633 	ops = rcu_dereference(inet_offloads[proto]);
1634 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1635 		goto out_unlock;
1636 
1637 	/* Only need to add sizeof(*iph) to get to the next hdr below
1638 	 * because any hdr with option will have been flushed in
1639 	 * inet_gro_receive().
1640 	 */
1641 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1642 			      tcp4_gro_complete, udp4_gro_complete,
1643 			      skb, nhoff + sizeof(*iph));
1644 
1645 out_unlock:
1646 	rcu_read_unlock();
1647 
1648 	return err;
1649 }
1650 EXPORT_SYMBOL(inet_gro_complete);
1651 
ipip_gro_complete(struct sk_buff * skb,int nhoff)1652 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1653 {
1654 	skb->encapsulation = 1;
1655 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1656 	return inet_gro_complete(skb, nhoff);
1657 }
1658 
inet_ctl_sock_create(struct sock ** sk,unsigned short family,unsigned short type,unsigned char protocol,struct net * net)1659 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1660 			 unsigned short type, unsigned char protocol,
1661 			 struct net *net)
1662 {
1663 	struct socket *sock;
1664 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1665 
1666 	if (rc == 0) {
1667 		*sk = sock->sk;
1668 		(*sk)->sk_allocation = GFP_ATOMIC;
1669 		/*
1670 		 * Unhash it so that IP input processing does not even see it,
1671 		 * we do not wish this socket to see incoming packets.
1672 		 */
1673 		(*sk)->sk_prot->unhash(*sk);
1674 	}
1675 	return rc;
1676 }
1677 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1678 
snmp_get_cpu_field(void __percpu * mib,int cpu,int offt)1679 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1680 {
1681 	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1682 }
1683 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1684 
snmp_fold_field(void __percpu * mib,int offt)1685 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1686 {
1687 	unsigned long res = 0;
1688 	int i;
1689 
1690 	for_each_possible_cpu(i)
1691 		res += snmp_get_cpu_field(mib, i, offt);
1692 	return res;
1693 }
1694 EXPORT_SYMBOL_GPL(snmp_fold_field);
1695 
1696 #if BITS_PER_LONG==32
1697 
snmp_get_cpu_field64(void __percpu * mib,int cpu,int offt,size_t syncp_offset)1698 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1699 			 size_t syncp_offset)
1700 {
1701 	void *bhptr;
1702 	struct u64_stats_sync *syncp;
1703 	u64 v;
1704 	unsigned int start;
1705 
1706 	bhptr = per_cpu_ptr(mib, cpu);
1707 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1708 	do {
1709 		start = u64_stats_fetch_begin_irq(syncp);
1710 		v = *(((u64 *)bhptr) + offt);
1711 	} while (u64_stats_fetch_retry_irq(syncp, start));
1712 
1713 	return v;
1714 }
1715 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1716 
snmp_fold_field64(void __percpu * mib,int offt,size_t syncp_offset)1717 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1718 {
1719 	u64 res = 0;
1720 	int cpu;
1721 
1722 	for_each_possible_cpu(cpu) {
1723 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1724 	}
1725 	return res;
1726 }
1727 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1728 #endif
1729 
1730 #ifdef CONFIG_IP_MULTICAST
1731 static const struct net_protocol igmp_protocol = {
1732 	.handler =	igmp_rcv,
1733 	.netns_ok =	1,
1734 };
1735 #endif
1736 
1737 static const struct net_protocol tcp_protocol = {
1738 	.handler	=	tcp_v4_rcv,
1739 	.err_handler	=	tcp_v4_err,
1740 	.no_policy	=	1,
1741 	.netns_ok	=	1,
1742 	.icmp_strict_tag_validation = 1,
1743 };
1744 
1745 static const struct net_protocol udp_protocol = {
1746 	.handler =	udp_rcv,
1747 	.err_handler =	udp_err,
1748 	.no_policy =	1,
1749 	.netns_ok =	1,
1750 };
1751 
1752 static const struct net_protocol icmp_protocol = {
1753 	.handler =	icmp_rcv,
1754 	.err_handler =	icmp_err,
1755 	.no_policy =	1,
1756 	.netns_ok =	1,
1757 };
1758 
ipv4_mib_init_net(struct net * net)1759 static __net_init int ipv4_mib_init_net(struct net *net)
1760 {
1761 	int i;
1762 
1763 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1764 	if (!net->mib.tcp_statistics)
1765 		goto err_tcp_mib;
1766 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1767 	if (!net->mib.ip_statistics)
1768 		goto err_ip_mib;
1769 
1770 	for_each_possible_cpu(i) {
1771 		struct ipstats_mib *af_inet_stats;
1772 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1773 		u64_stats_init(&af_inet_stats->syncp);
1774 	}
1775 
1776 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1777 	if (!net->mib.net_statistics)
1778 		goto err_net_mib;
1779 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1780 	if (!net->mib.udp_statistics)
1781 		goto err_udp_mib;
1782 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1783 	if (!net->mib.udplite_statistics)
1784 		goto err_udplite_mib;
1785 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1786 	if (!net->mib.icmp_statistics)
1787 		goto err_icmp_mib;
1788 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1789 					      GFP_KERNEL);
1790 	if (!net->mib.icmpmsg_statistics)
1791 		goto err_icmpmsg_mib;
1792 
1793 	tcp_mib_init(net);
1794 	return 0;
1795 
1796 err_icmpmsg_mib:
1797 	free_percpu(net->mib.icmp_statistics);
1798 err_icmp_mib:
1799 	free_percpu(net->mib.udplite_statistics);
1800 err_udplite_mib:
1801 	free_percpu(net->mib.udp_statistics);
1802 err_udp_mib:
1803 	free_percpu(net->mib.net_statistics);
1804 err_net_mib:
1805 	free_percpu(net->mib.ip_statistics);
1806 err_ip_mib:
1807 	free_percpu(net->mib.tcp_statistics);
1808 err_tcp_mib:
1809 	return -ENOMEM;
1810 }
1811 
ipv4_mib_exit_net(struct net * net)1812 static __net_exit void ipv4_mib_exit_net(struct net *net)
1813 {
1814 	kfree(net->mib.icmpmsg_statistics);
1815 	free_percpu(net->mib.icmp_statistics);
1816 	free_percpu(net->mib.udplite_statistics);
1817 	free_percpu(net->mib.udp_statistics);
1818 	free_percpu(net->mib.net_statistics);
1819 	free_percpu(net->mib.ip_statistics);
1820 	free_percpu(net->mib.tcp_statistics);
1821 #ifdef CONFIG_MPTCP
1822 	/* allocated on demand, see mptcp_init_sock() */
1823 	free_percpu(net->mib.mptcp_statistics);
1824 #endif
1825 }
1826 
1827 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1828 	.init = ipv4_mib_init_net,
1829 	.exit = ipv4_mib_exit_net,
1830 };
1831 
init_ipv4_mibs(void)1832 static int __init init_ipv4_mibs(void)
1833 {
1834 	return register_pernet_subsys(&ipv4_mib_ops);
1835 }
1836 
inet_init_net(struct net * net)1837 static __net_init int inet_init_net(struct net *net)
1838 {
1839 	/*
1840 	 * Set defaults for local port range
1841 	 */
1842 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1843 	net->ipv4.ip_local_ports.range[0] =  32768;
1844 	net->ipv4.ip_local_ports.range[1] =  60999;
1845 
1846 	seqlock_init(&net->ipv4.ping_group_range.lock);
1847 	/*
1848 	 * Sane defaults - nobody may create ping sockets.
1849 	 * Boot scripts should set this to distro-specific group.
1850 	 */
1851 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1852 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1853 
1854 	/* Default values for sysctl-controlled parameters.
1855 	 * We set them here, in case sysctl is not compiled.
1856 	 */
1857 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1858 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1859 	net->ipv4.sysctl_ip_dynaddr = 0;
1860 	net->ipv4.sysctl_ip_early_demux = 1;
1861 	net->ipv4.sysctl_udp_early_demux = 1;
1862 	net->ipv4.sysctl_tcp_early_demux = 1;
1863 	net->ipv4.sysctl_nexthop_compat_mode = 1;
1864 #ifdef CONFIG_SYSCTL
1865 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1866 #endif
1867 
1868 	/* Some igmp sysctl, whose values are always used */
1869 	net->ipv4.sysctl_igmp_max_memberships = 20;
1870 	net->ipv4.sysctl_igmp_max_msf = 10;
1871 	/* IGMP reports for link-local multicast groups are enabled by default */
1872 	net->ipv4.sysctl_igmp_llm_reports = 1;
1873 	net->ipv4.sysctl_igmp_qrv = 2;
1874 
1875 	return 0;
1876 }
1877 
1878 static __net_initdata struct pernet_operations af_inet_ops = {
1879 	.init = inet_init_net,
1880 };
1881 
init_inet_pernet_ops(void)1882 static int __init init_inet_pernet_ops(void)
1883 {
1884 	return register_pernet_subsys(&af_inet_ops);
1885 }
1886 
1887 static int ipv4_proc_init(void);
1888 
1889 /*
1890  *	IP protocol layer initialiser
1891  */
1892 
1893 static struct packet_offload ip_packet_offload __read_mostly = {
1894 	.type = cpu_to_be16(ETH_P_IP),
1895 	.callbacks = {
1896 		.gso_segment = inet_gso_segment,
1897 		.gro_receive = inet_gro_receive,
1898 		.gro_complete = inet_gro_complete,
1899 	},
1900 };
1901 
1902 static const struct net_offload ipip_offload = {
1903 	.callbacks = {
1904 		.gso_segment	= ipip_gso_segment,
1905 		.gro_receive	= ipip_gro_receive,
1906 		.gro_complete	= ipip_gro_complete,
1907 	},
1908 };
1909 
ipip_offload_init(void)1910 static int __init ipip_offload_init(void)
1911 {
1912 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1913 }
1914 
ipv4_offload_init(void)1915 static int __init ipv4_offload_init(void)
1916 {
1917 	/*
1918 	 * Add offloads
1919 	 */
1920 	if (udpv4_offload_init() < 0)
1921 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1922 	if (tcpv4_offload_init() < 0)
1923 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1924 	if (ipip_offload_init() < 0)
1925 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1926 
1927 	dev_add_offload(&ip_packet_offload);
1928 	return 0;
1929 }
1930 
1931 fs_initcall(ipv4_offload_init);
1932 
1933 static struct packet_type ip_packet_type __read_mostly = {
1934 	.type = cpu_to_be16(ETH_P_IP),
1935 	.func = ip_rcv,
1936 	.list_func = ip_list_rcv,
1937 };
1938 
inet_init(void)1939 static int __init inet_init(void)
1940 {
1941 	struct inet_protosw *q;
1942 	struct list_head *r;
1943 	int rc;
1944 
1945 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1946 
1947 	rc = proto_register(&tcp_prot, 1);
1948 	if (rc)
1949 		goto out;
1950 
1951 	rc = proto_register(&udp_prot, 1);
1952 	if (rc)
1953 		goto out_unregister_tcp_proto;
1954 
1955 	rc = proto_register(&raw_prot, 1);
1956 	if (rc)
1957 		goto out_unregister_udp_proto;
1958 
1959 	rc = proto_register(&ping_prot, 1);
1960 	if (rc)
1961 		goto out_unregister_raw_proto;
1962 
1963 	/*
1964 	 *	Tell SOCKET that we are alive...
1965 	 */
1966 
1967 	(void)sock_register(&inet_family_ops);
1968 
1969 #ifdef CONFIG_SYSCTL
1970 	ip_static_sysctl_init();
1971 #endif
1972 
1973 	/*
1974 	 *	Add all the base protocols.
1975 	 */
1976 
1977 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1978 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1979 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1980 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1981 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1982 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1983 #ifdef CONFIG_IP_MULTICAST
1984 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1985 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1986 #endif
1987 
1988 	/* Register the socket-side information for inet_create. */
1989 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1990 		INIT_LIST_HEAD(r);
1991 
1992 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1993 		inet_register_protosw(q);
1994 
1995 	/*
1996 	 *	Set the ARP module up
1997 	 */
1998 
1999 	arp_init();
2000 
2001 	/*
2002 	 *	Set the IP module up
2003 	 */
2004 
2005 	ip_init();
2006 
2007 	/* Initialise per-cpu ipv4 mibs */
2008 	if (init_ipv4_mibs())
2009 		panic("%s: Cannot init ipv4 mibs\n", __func__);
2010 
2011 	/* Setup TCP slab cache for open requests. */
2012 	tcp_init();
2013 
2014 	/* Setup UDP memory threshold */
2015 	udp_init();
2016 
2017 	/* Add UDP-Lite (RFC 3828) */
2018 	udplite4_register();
2019 
2020 	raw_init();
2021 
2022 	ping_init();
2023 
2024 	/*
2025 	 *	Set the ICMP layer up
2026 	 */
2027 
2028 	if (icmp_init() < 0)
2029 		panic("Failed to create the ICMP control socket.\n");
2030 
2031 	/*
2032 	 *	Initialise the multicast router
2033 	 */
2034 #if defined(CONFIG_IP_MROUTE)
2035 	if (ip_mr_init())
2036 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2037 #endif
2038 
2039 	if (init_inet_pernet_ops())
2040 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2041 
2042 	ipv4_proc_init();
2043 
2044 	ipfrag_init();
2045 
2046 	dev_add_pack(&ip_packet_type);
2047 
2048 	ip_tunnel_core_init();
2049 
2050 	rc = 0;
2051 out:
2052 	return rc;
2053 out_unregister_raw_proto:
2054 	proto_unregister(&raw_prot);
2055 out_unregister_udp_proto:
2056 	proto_unregister(&udp_prot);
2057 out_unregister_tcp_proto:
2058 	proto_unregister(&tcp_prot);
2059 	goto out;
2060 }
2061 
2062 fs_initcall(inet_init);
2063 
2064 /* ------------------------------------------------------------------------ */
2065 
2066 #ifdef CONFIG_PROC_FS
ipv4_proc_init(void)2067 static int __init ipv4_proc_init(void)
2068 {
2069 	int rc = 0;
2070 
2071 	if (raw_proc_init())
2072 		goto out_raw;
2073 	if (tcp4_proc_init())
2074 		goto out_tcp;
2075 	if (udp4_proc_init())
2076 		goto out_udp;
2077 	if (ping_proc_init())
2078 		goto out_ping;
2079 	if (ip_misc_proc_init())
2080 		goto out_misc;
2081 out:
2082 	return rc;
2083 out_misc:
2084 	ping_proc_exit();
2085 out_ping:
2086 	udp4_proc_exit();
2087 out_udp:
2088 	tcp4_proc_exit();
2089 out_tcp:
2090 	raw_proc_exit();
2091 out_raw:
2092 	rc = -ENOMEM;
2093 	goto out;
2094 }
2095 
2096 #else /* CONFIG_PROC_FS */
ipv4_proc_init(void)2097 static int __init ipv4_proc_init(void)
2098 {
2099 	return 0;
2100 }
2101 #endif /* CONFIG_PROC_FS */
2102