• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 
120 #include <trace/events/sock.h>
121 
122 /* The inetsw table contains everything that inet_create needs to
123  * build a new socket.
124  */
125 static struct list_head inetsw[SOCK_MAX];
126 static DEFINE_SPINLOCK(inetsw_lock);
127 
128 /* New destruction routine */
129 
inet_sock_destruct(struct sock * sk)130 void inet_sock_destruct(struct sock *sk)
131 {
132 	struct inet_sock *inet = inet_sk(sk);
133 
134 	__skb_queue_purge(&sk->sk_receive_queue);
135 	if (sk->sk_rx_skb_cache) {
136 		__kfree_skb(sk->sk_rx_skb_cache);
137 		sk->sk_rx_skb_cache = NULL;
138 	}
139 	__skb_queue_purge(&sk->sk_error_queue);
140 
141 	sk_mem_reclaim(sk);
142 
143 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
144 		pr_err("Attempt to release TCP socket in state %d %p\n",
145 		       sk->sk_state, sk);
146 		return;
147 	}
148 	if (!sock_flag(sk, SOCK_DEAD)) {
149 		pr_err("Attempt to release alive inet socket %p\n", sk);
150 		return;
151 	}
152 
153 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
154 	WARN_ON(refcount_read(&sk->sk_wmem_alloc));
155 	WARN_ON(sk->sk_wmem_queued);
156 	WARN_ON(sk->sk_forward_alloc);
157 
158 	kfree(rcu_dereference_protected(inet->inet_opt, 1));
159 	dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1));
160 	dst_release(rcu_dereference_protected(sk->sk_rx_dst, 1));
161 	sk_refcnt_debug_dec(sk);
162 }
163 EXPORT_SYMBOL(inet_sock_destruct);
164 
165 /*
166  *	The routines beyond this point handle the behaviour of an AF_INET
167  *	socket object. Mostly it punts to the subprotocols of IP to do
168  *	the work.
169  */
170 
171 /*
172  *	Automatically bind an unbound socket.
173  */
174 
inet_autobind(struct sock * sk)175 static int inet_autobind(struct sock *sk)
176 {
177 	struct inet_sock *inet;
178 	/* We may need to bind the socket. */
179 	lock_sock(sk);
180 	inet = inet_sk(sk);
181 	if (!inet->inet_num) {
182 		if (sk->sk_prot->get_port(sk, 0)) {
183 			release_sock(sk);
184 			return -EAGAIN;
185 		}
186 		inet->inet_sport = htons(inet->inet_num);
187 	}
188 	release_sock(sk);
189 	return 0;
190 }
191 
192 /*
193  *	Move a socket into listening state.
194  */
inet_listen(struct socket * sock,int backlog)195 int inet_listen(struct socket *sock, int backlog)
196 {
197 	struct sock *sk = sock->sk;
198 	unsigned char old_state;
199 	int err, tcp_fastopen;
200 
201 	lock_sock(sk);
202 
203 	err = -EINVAL;
204 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
205 		goto out;
206 
207 	old_state = sk->sk_state;
208 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
209 		goto out;
210 
211 	sk->sk_max_ack_backlog = backlog;
212 	/* Really, if the socket is already in listen state
213 	 * we can only allow the backlog to be adjusted.
214 	 */
215 	if (old_state != TCP_LISTEN) {
216 		/* Enable TFO w/o requiring TCP_FASTOPEN socket option.
217 		 * Note that only TCP sockets (SOCK_STREAM) will reach here.
218 		 * Also fastopen backlog may already been set via the option
219 		 * because the socket was in TCP_LISTEN state previously but
220 		 * was shutdown() rather than close().
221 		 */
222 		tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
223 		if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) &&
224 		    (tcp_fastopen & TFO_SERVER_ENABLE) &&
225 		    !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) {
226 			fastopen_queue_tune(sk, backlog);
227 			tcp_fastopen_init_key_once(sock_net(sk));
228 		}
229 
230 		err = inet_csk_listen_start(sk, backlog);
231 		if (err)
232 			goto out;
233 		tcp_call_bpf(sk, BPF_SOCK_OPS_TCP_LISTEN_CB, 0, NULL);
234 	}
235 	err = 0;
236 
237 out:
238 	release_sock(sk);
239 	return err;
240 }
241 EXPORT_SYMBOL(inet_listen);
242 
243 /*
244  *	Create an inet socket.
245  */
246 
inet_create(struct net * net,struct socket * sock,int protocol,int kern)247 static int inet_create(struct net *net, struct socket *sock, int protocol,
248 		       int kern)
249 {
250 	struct sock *sk;
251 	struct inet_protosw *answer;
252 	struct inet_sock *inet;
253 	struct proto *answer_prot;
254 	unsigned char answer_flags;
255 	int try_loading_module = 0;
256 	int err;
257 
258 	if (protocol < 0 || protocol >= IPPROTO_MAX)
259 		return -EINVAL;
260 
261 	sock->state = SS_UNCONNECTED;
262 
263 	/* Look for the requested type/protocol pair. */
264 lookup_protocol:
265 	err = -ESOCKTNOSUPPORT;
266 	rcu_read_lock();
267 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
268 
269 		err = 0;
270 		/* Check the non-wild match. */
271 		if (protocol == answer->protocol) {
272 			if (protocol != IPPROTO_IP)
273 				break;
274 		} else {
275 			/* Check for the two wild cases. */
276 			if (IPPROTO_IP == protocol) {
277 				protocol = answer->protocol;
278 				break;
279 			}
280 			if (IPPROTO_IP == answer->protocol)
281 				break;
282 		}
283 		err = -EPROTONOSUPPORT;
284 	}
285 
286 	if (unlikely(err)) {
287 		if (try_loading_module < 2) {
288 			rcu_read_unlock();
289 			/*
290 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
291 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
292 			 */
293 			if (++try_loading_module == 1)
294 				request_module("net-pf-%d-proto-%d-type-%d",
295 					       PF_INET, protocol, sock->type);
296 			/*
297 			 * Fall back to generic, e.g. net-pf-2-proto-132
298 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
299 			 */
300 			else
301 				request_module("net-pf-%d-proto-%d",
302 					       PF_INET, protocol);
303 			goto lookup_protocol;
304 		} else
305 			goto out_rcu_unlock;
306 	}
307 
308 	err = -EPERM;
309 	if (sock->type == SOCK_RAW && !kern &&
310 	    !ns_capable(net->user_ns, CAP_NET_RAW))
311 		goto out_rcu_unlock;
312 
313 	sock->ops = answer->ops;
314 	answer_prot = answer->prot;
315 	answer_flags = answer->flags;
316 	rcu_read_unlock();
317 
318 	WARN_ON(!answer_prot->slab);
319 
320 	err = -ENOBUFS;
321 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot, kern);
322 	if (!sk)
323 		goto out;
324 
325 	err = 0;
326 	if (INET_PROTOSW_REUSE & answer_flags)
327 		sk->sk_reuse = SK_CAN_REUSE;
328 
329 	inet = inet_sk(sk);
330 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
331 
332 	inet->nodefrag = 0;
333 
334 	if (SOCK_RAW == sock->type) {
335 		inet->inet_num = protocol;
336 		if (IPPROTO_RAW == protocol)
337 			inet->hdrincl = 1;
338 	}
339 
340 	if (READ_ONCE(net->ipv4.sysctl_ip_no_pmtu_disc))
341 		inet->pmtudisc = IP_PMTUDISC_DONT;
342 	else
343 		inet->pmtudisc = IP_PMTUDISC_WANT;
344 
345 	inet->inet_id = 0;
346 
347 	sock_init_data(sock, sk);
348 
349 	sk->sk_destruct	   = inet_sock_destruct;
350 	sk->sk_protocol	   = protocol;
351 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
352 
353 	inet->uc_ttl	= -1;
354 	inet->mc_loop	= 1;
355 	inet->mc_ttl	= 1;
356 	inet->mc_all	= 1;
357 	inet->mc_index	= 0;
358 	inet->mc_list	= NULL;
359 	inet->rcv_tos	= 0;
360 
361 	sk_refcnt_debug_inc(sk);
362 
363 	if (inet->inet_num) {
364 		/* It assumes that any protocol which allows
365 		 * the user to assign a number at socket
366 		 * creation time automatically
367 		 * shares.
368 		 */
369 		inet->inet_sport = htons(inet->inet_num);
370 		/* Add to protocol hash chains. */
371 		err = sk->sk_prot->hash(sk);
372 		if (err) {
373 			sk_common_release(sk);
374 			goto out;
375 		}
376 	}
377 
378 	if (sk->sk_prot->init) {
379 		err = sk->sk_prot->init(sk);
380 		if (err) {
381 			sk_common_release(sk);
382 			goto out;
383 		}
384 	}
385 
386 	if (!kern) {
387 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
388 		if (err) {
389 			sk_common_release(sk);
390 			goto out;
391 		}
392 	}
393 out:
394 	return err;
395 out_rcu_unlock:
396 	rcu_read_unlock();
397 	goto out;
398 }
399 
400 
401 /*
402  *	The peer socket should always be NULL (or else). When we call this
403  *	function we are destroying the object and from then on nobody
404  *	should refer to it.
405  */
inet_release(struct socket * sock)406 int inet_release(struct socket *sock)
407 {
408 	struct sock *sk = sock->sk;
409 
410 	if (sk) {
411 		long timeout;
412 
413 		/* Applications forget to leave groups before exiting */
414 		ip_mc_drop_socket(sk);
415 
416 		/* If linger is set, we don't return until the close
417 		 * is complete.  Otherwise we return immediately. The
418 		 * actually closing is done the same either way.
419 		 *
420 		 * If the close is due to the process exiting, we never
421 		 * linger..
422 		 */
423 		timeout = 0;
424 		if (sock_flag(sk, SOCK_LINGER) &&
425 		    !(current->flags & PF_EXITING))
426 			timeout = sk->sk_lingertime;
427 		sk->sk_prot->close(sk, timeout);
428 		sock->sk = NULL;
429 	}
430 	return 0;
431 }
432 EXPORT_SYMBOL(inet_release);
433 
inet_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)434 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
435 {
436 	struct sock *sk = sock->sk;
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_INET4_BIND(sk, uaddr);
450 	if (err)
451 		return err;
452 
453 	return __inet_bind(sk, uaddr, addr_len, false, true);
454 }
455 EXPORT_SYMBOL(inet_bind);
456 
__inet_bind(struct sock * sk,struct sockaddr * uaddr,int addr_len,bool force_bind_address_no_port,bool with_lock)457 int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
458 		bool force_bind_address_no_port, bool with_lock)
459 {
460 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
461 	struct inet_sock *inet = inet_sk(sk);
462 	struct net *net = sock_net(sk);
463 	unsigned short snum;
464 	int chk_addr_ret;
465 	u32 tb_id = RT_TABLE_LOCAL;
466 	int err;
467 
468 	if (addr->sin_family != AF_INET) {
469 		/* Compatibility games : accept AF_UNSPEC (mapped to AF_INET)
470 		 * only if s_addr is INADDR_ANY.
471 		 */
472 		err = -EAFNOSUPPORT;
473 		if (addr->sin_family != AF_UNSPEC ||
474 		    addr->sin_addr.s_addr != htonl(INADDR_ANY))
475 			goto out;
476 	}
477 
478 	tb_id = l3mdev_fib_table_by_index(net, sk->sk_bound_dev_if) ? : tb_id;
479 	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
480 
481 	/* Not specified by any standard per-se, however it breaks too
482 	 * many applications when removed.  It is unfortunate since
483 	 * allowing applications to make a non-local bind solves
484 	 * several problems with systems using dynamic addressing.
485 	 * (ie. your servers still start up even if your ISDN link
486 	 *  is temporarily down)
487 	 */
488 	err = -EADDRNOTAVAIL;
489 	if (!inet_can_nonlocal_bind(net, inet) &&
490 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
491 	    chk_addr_ret != RTN_LOCAL &&
492 	    chk_addr_ret != RTN_MULTICAST &&
493 	    chk_addr_ret != RTN_BROADCAST)
494 		goto out;
495 
496 	snum = ntohs(addr->sin_port);
497 	err = -EPERM;
498 	if (snum && inet_is_local_unbindable_port(net, snum))
499 		goto out;
500 
501 	err = -EACCES;
502 	if (snum && snum < inet_prot_sock(net) &&
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 (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 		      force_bind_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 		err = BPF_CGROUP_RUN_PROG_INET4_POST_BIND(sk);
534 		if (err) {
535 			inet->inet_saddr = inet->inet_rcv_saddr = 0;
536 			goto out_release_sock;
537 		}
538 	}
539 
540 	if (inet->inet_rcv_saddr)
541 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
542 	if (snum)
543 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
544 	inet->inet_sport = htons(inet->inet_num);
545 	inet->inet_daddr = 0;
546 	inet->inet_dport = 0;
547 	sk_dst_reset(sk);
548 	err = 0;
549 out_release_sock:
550 	if (with_lock)
551 		release_sock(sk);
552 out:
553 	return err;
554 }
555 
inet_dgram_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)556 int inet_dgram_connect(struct socket *sock, struct sockaddr *uaddr,
557 		       int addr_len, int flags)
558 {
559 	struct sock *sk = sock->sk;
560 	int err;
561 
562 	if (addr_len < sizeof(uaddr->sa_family))
563 		return -EINVAL;
564 	if (uaddr->sa_family == AF_UNSPEC)
565 		return sk->sk_prot->disconnect(sk, flags);
566 
567 	if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
568 		err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
569 		if (err)
570 			return err;
571 	}
572 
573 	if (!inet_sk(sk)->inet_num && inet_autobind(sk))
574 		return -EAGAIN;
575 	return sk->sk_prot->connect(sk, uaddr, addr_len);
576 }
577 EXPORT_SYMBOL(inet_dgram_connect);
578 
inet_wait_for_connect(struct sock * sk,long timeo,int writebias)579 static long inet_wait_for_connect(struct sock *sk, long timeo, int writebias)
580 {
581 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
582 
583 	add_wait_queue(sk_sleep(sk), &wait);
584 	sk->sk_write_pending += writebias;
585 
586 	/* Basic assumption: if someone sets sk->sk_err, he _must_
587 	 * change state of the socket from TCP_SYN_*.
588 	 * Connect() does not allow to get error notifications
589 	 * without closing the socket.
590 	 */
591 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
592 		release_sock(sk);
593 		timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
594 		lock_sock(sk);
595 		if (signal_pending(current) || !timeo)
596 			break;
597 	}
598 	remove_wait_queue(sk_sleep(sk), &wait);
599 	sk->sk_write_pending -= writebias;
600 	return timeo;
601 }
602 
603 /*
604  *	Connect to a remote host. There is regrettably still a little
605  *	TCP 'magic' in here.
606  */
__inet_stream_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags,int is_sendmsg)607 int __inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
608 			  int addr_len, int flags, int is_sendmsg)
609 {
610 	struct sock *sk = sock->sk;
611 	int err;
612 	long timeo;
613 
614 	/*
615 	 * uaddr can be NULL and addr_len can be 0 if:
616 	 * sk is a TCP fastopen active socket and
617 	 * TCP_FASTOPEN_CONNECT sockopt is set and
618 	 * we already have a valid cookie for this socket.
619 	 * In this case, user can call write() after connect().
620 	 * write() will invoke tcp_sendmsg_fastopen() which calls
621 	 * __inet_stream_connect().
622 	 */
623 	if (uaddr) {
624 		if (addr_len < sizeof(uaddr->sa_family))
625 			return -EINVAL;
626 
627 		if (uaddr->sa_family == AF_UNSPEC) {
628 			err = sk->sk_prot->disconnect(sk, flags);
629 			sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
630 			goto out;
631 		}
632 	}
633 
634 	switch (sock->state) {
635 	default:
636 		err = -EINVAL;
637 		goto out;
638 	case SS_CONNECTED:
639 		err = -EISCONN;
640 		goto out;
641 	case SS_CONNECTING:
642 		if (inet_sk(sk)->defer_connect)
643 			err = is_sendmsg ? -EINPROGRESS : -EISCONN;
644 		else
645 			err = -EALREADY;
646 		/* Fall out of switch with err, set for this state */
647 		break;
648 	case SS_UNCONNECTED:
649 		err = -EISCONN;
650 		if (sk->sk_state != TCP_CLOSE)
651 			goto out;
652 
653 		if (BPF_CGROUP_PRE_CONNECT_ENABLED(sk)) {
654 			err = sk->sk_prot->pre_connect(sk, uaddr, addr_len);
655 			if (err)
656 				goto out;
657 		}
658 
659 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
660 		if (err < 0)
661 			goto out;
662 
663 		sock->state = SS_CONNECTING;
664 
665 		if (!err && inet_sk(sk)->defer_connect)
666 			goto out;
667 
668 		/* Just entered SS_CONNECTING state; the only
669 		 * difference is that return value in non-blocking
670 		 * case is EINPROGRESS, rather than EALREADY.
671 		 */
672 		err = -EINPROGRESS;
673 		break;
674 	}
675 
676 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
677 
678 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
679 		int writebias = (sk->sk_protocol == IPPROTO_TCP) &&
680 				tcp_sk(sk)->fastopen_req &&
681 				tcp_sk(sk)->fastopen_req->data ? 1 : 0;
682 
683 		/* Error code is set above */
684 		if (!timeo || !inet_wait_for_connect(sk, timeo, writebias))
685 			goto out;
686 
687 		err = sock_intr_errno(timeo);
688 		if (signal_pending(current))
689 			goto out;
690 	}
691 
692 	/* Connection was closed by RST, timeout, ICMP error
693 	 * or another process disconnected us.
694 	 */
695 	if (sk->sk_state == TCP_CLOSE)
696 		goto sock_error;
697 
698 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
699 	 * and error was received after socket entered established state.
700 	 * Hence, it is handled normally after connect() return successfully.
701 	 */
702 
703 	sock->state = SS_CONNECTED;
704 	err = 0;
705 out:
706 	return err;
707 
708 sock_error:
709 	err = sock_error(sk) ? : -ECONNABORTED;
710 	sock->state = SS_UNCONNECTED;
711 	if (sk->sk_prot->disconnect(sk, flags))
712 		sock->state = SS_DISCONNECTING;
713 	goto out;
714 }
715 EXPORT_SYMBOL(__inet_stream_connect);
716 
inet_stream_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)717 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
718 			int addr_len, int flags)
719 {
720 	int err;
721 
722 	lock_sock(sock->sk);
723 	err = __inet_stream_connect(sock, uaddr, addr_len, flags, 0);
724 	release_sock(sock->sk);
725 	return err;
726 }
727 EXPORT_SYMBOL(inet_stream_connect);
728 
729 /*
730  *	Accept a pending connection. The TCP layer now gives BSD semantics.
731  */
732 
inet_accept(struct socket * sock,struct socket * newsock,int flags,bool kern)733 int inet_accept(struct socket *sock, struct socket *newsock, int flags,
734 		bool kern)
735 {
736 	struct sock *sk1 = sock->sk;
737 	int err = -EINVAL;
738 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err, kern);
739 
740 	if (!sk2)
741 		goto do_err;
742 
743 	lock_sock(sk2);
744 
745 	sock_rps_record_flow(sk2);
746 	WARN_ON(!((1 << sk2->sk_state) &
747 		  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
748 		  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
749 
750 	sock_graft(sk2, newsock);
751 
752 	newsock->state = SS_CONNECTED;
753 	err = 0;
754 	release_sock(sk2);
755 do_err:
756 	return err;
757 }
758 EXPORT_SYMBOL(inet_accept);
759 
760 
761 /*
762  *	This does both peername and sockname.
763  */
inet_getname(struct socket * sock,struct sockaddr * uaddr,int peer)764 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
765 			int peer)
766 {
767 	struct sock *sk		= sock->sk;
768 	struct inet_sock *inet	= inet_sk(sk);
769 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);
770 
771 	sin->sin_family = AF_INET;
772 	if (peer) {
773 		if (!inet->inet_dport ||
774 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
775 		     peer == 1))
776 			return -ENOTCONN;
777 		sin->sin_port = inet->inet_dport;
778 		sin->sin_addr.s_addr = inet->inet_daddr;
779 	} else {
780 		__be32 addr = inet->inet_rcv_saddr;
781 		if (!addr)
782 			addr = inet->inet_saddr;
783 		sin->sin_port = inet->inet_sport;
784 		sin->sin_addr.s_addr = addr;
785 	}
786 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
787 	return sizeof(*sin);
788 }
789 EXPORT_SYMBOL(inet_getname);
790 
inet_send_prepare(struct sock * sk)791 int inet_send_prepare(struct sock *sk)
792 {
793 	sock_rps_record_flow(sk);
794 
795 	/* We may need to bind the socket. */
796 	if (!inet_sk(sk)->inet_num && !sk->sk_prot->no_autobind &&
797 	    inet_autobind(sk))
798 		return -EAGAIN;
799 
800 	return 0;
801 }
802 EXPORT_SYMBOL_GPL(inet_send_prepare);
803 
inet_sendmsg(struct socket * sock,struct msghdr * msg,size_t size)804 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
805 {
806 	struct sock *sk = sock->sk;
807 
808 	if (unlikely(inet_send_prepare(sk)))
809 		return -EAGAIN;
810 
811 	return INDIRECT_CALL_2(sk->sk_prot->sendmsg, tcp_sendmsg, udp_sendmsg,
812 			       sk, msg, size);
813 }
814 EXPORT_SYMBOL(inet_sendmsg);
815 
inet_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)816 ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset,
817 		      size_t size, int flags)
818 {
819 	struct sock *sk = sock->sk;
820 
821 	if (unlikely(inet_send_prepare(sk)))
822 		return -EAGAIN;
823 
824 	if (sk->sk_prot->sendpage)
825 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
826 	return sock_no_sendpage(sock, page, offset, size, flags);
827 }
828 EXPORT_SYMBOL(inet_sendpage);
829 
830 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
831 					  size_t, int, int, int *));
inet_recvmsg(struct socket * sock,struct msghdr * msg,size_t size,int flags)832 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
833 		 int flags)
834 {
835 	struct sock *sk = sock->sk;
836 	int addr_len = 0;
837 	int err;
838 
839 	if (likely(!(flags & MSG_ERRQUEUE)))
840 		sock_rps_record_flow(sk);
841 
842 	err = INDIRECT_CALL_2(sk->sk_prot->recvmsg, tcp_recvmsg, udp_recvmsg,
843 			      sk, msg, size, flags & MSG_DONTWAIT,
844 			      flags & ~MSG_DONTWAIT, &addr_len);
845 	if (err >= 0)
846 		msg->msg_namelen = addr_len;
847 	return err;
848 }
849 EXPORT_SYMBOL(inet_recvmsg);
850 
inet_shutdown(struct socket * sock,int how)851 int inet_shutdown(struct socket *sock, int how)
852 {
853 	struct sock *sk = sock->sk;
854 	int err = 0;
855 
856 	/* This should really check to make sure
857 	 * the socket is a TCP socket. (WHY AC...)
858 	 */
859 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
860 		       1->2 bit 2 snds.
861 		       2->3 */
862 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
863 		return -EINVAL;
864 
865 	lock_sock(sk);
866 	if (sock->state == SS_CONNECTING) {
867 		if ((1 << sk->sk_state) &
868 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
869 			sock->state = SS_DISCONNECTING;
870 		else
871 			sock->state = SS_CONNECTED;
872 	}
873 
874 	switch (sk->sk_state) {
875 	case TCP_CLOSE:
876 		err = -ENOTCONN;
877 		/* Hack to wake up other listeners, who can poll for
878 		   EPOLLHUP, even on eg. unconnected UDP sockets -- RR */
879 		/* fall through */
880 	default:
881 		WRITE_ONCE(sk->sk_shutdown, sk->sk_shutdown | how);
882 		if (sk->sk_prot->shutdown)
883 			sk->sk_prot->shutdown(sk, how);
884 		break;
885 
886 	/* Remaining two branches are temporary solution for missing
887 	 * close() in multithreaded environment. It is _not_ a good idea,
888 	 * but we have no choice until close() is repaired at VFS level.
889 	 */
890 	case TCP_LISTEN:
891 		if (!(how & RCV_SHUTDOWN))
892 			break;
893 		/* fall through */
894 	case TCP_SYN_SENT:
895 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
896 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
897 		break;
898 	}
899 
900 	/* Wake up anyone sleeping in poll. */
901 	sk->sk_state_change(sk);
902 	release_sock(sk);
903 	return err;
904 }
905 EXPORT_SYMBOL(inet_shutdown);
906 
907 /*
908  *	ioctl() calls you can issue on an INET socket. Most of these are
909  *	device configuration and stuff and very rarely used. Some ioctls
910  *	pass on to the socket itself.
911  *
912  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
913  *	loads the devconfigure module does its configuring and unloads it.
914  *	There's a good 20K of config code hanging around the kernel.
915  */
916 
inet_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)917 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
918 {
919 	struct sock *sk = sock->sk;
920 	int err = 0;
921 	struct net *net = sock_net(sk);
922 	void __user *p = (void __user *)arg;
923 	struct ifreq ifr;
924 	struct rtentry rt;
925 
926 	switch (cmd) {
927 	case SIOCADDRT:
928 	case SIOCDELRT:
929 		if (copy_from_user(&rt, p, sizeof(struct rtentry)))
930 			return -EFAULT;
931 		err = ip_rt_ioctl(net, cmd, &rt);
932 		break;
933 	case SIOCRTMSG:
934 		err = -EINVAL;
935 		break;
936 	case SIOCDARP:
937 	case SIOCGARP:
938 	case SIOCSARP:
939 		err = arp_ioctl(net, cmd, (void __user *)arg);
940 		break;
941 	case SIOCGIFADDR:
942 	case SIOCGIFBRDADDR:
943 	case SIOCGIFNETMASK:
944 	case SIOCGIFDSTADDR:
945 	case SIOCGIFPFLAGS:
946 		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
947 			return -EFAULT;
948 		err = devinet_ioctl(net, cmd, &ifr);
949 		if (!err && copy_to_user(p, &ifr, sizeof(struct ifreq)))
950 			err = -EFAULT;
951 		break;
952 
953 	case SIOCSIFADDR:
954 	case SIOCSIFBRDADDR:
955 	case SIOCSIFNETMASK:
956 	case SIOCSIFDSTADDR:
957 	case SIOCSIFPFLAGS:
958 	case SIOCSIFFLAGS:
959 		if (copy_from_user(&ifr, p, sizeof(struct ifreq)))
960 			return -EFAULT;
961 		err = devinet_ioctl(net, cmd, &ifr);
962 		break;
963 	default:
964 		if (sk->sk_prot->ioctl)
965 			err = sk->sk_prot->ioctl(sk, cmd, arg);
966 		else
967 			err = -ENOIOCTLCMD;
968 		break;
969 	}
970 	return err;
971 }
972 EXPORT_SYMBOL(inet_ioctl);
973 
974 #ifdef CONFIG_COMPAT
inet_compat_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)975 static int inet_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
976 {
977 	struct sock *sk = sock->sk;
978 	int err = -ENOIOCTLCMD;
979 
980 	if (sk->sk_prot->compat_ioctl)
981 		err = sk->sk_prot->compat_ioctl(sk, cmd, arg);
982 
983 	return err;
984 }
985 #endif
986 
987 const struct proto_ops inet_stream_ops = {
988 	.family		   = PF_INET,
989 	.owner		   = THIS_MODULE,
990 	.release	   = inet_release,
991 	.bind		   = inet_bind,
992 	.connect	   = inet_stream_connect,
993 	.socketpair	   = sock_no_socketpair,
994 	.accept		   = inet_accept,
995 	.getname	   = inet_getname,
996 	.poll		   = tcp_poll,
997 	.ioctl		   = inet_ioctl,
998 	.gettstamp	   = sock_gettstamp,
999 	.listen		   = inet_listen,
1000 	.shutdown	   = inet_shutdown,
1001 	.setsockopt	   = sock_common_setsockopt,
1002 	.getsockopt	   = sock_common_getsockopt,
1003 	.sendmsg	   = inet_sendmsg,
1004 	.recvmsg	   = inet_recvmsg,
1005 #ifdef CONFIG_MMU
1006 	.mmap		   = tcp_mmap,
1007 #endif
1008 	.sendpage	   = inet_sendpage,
1009 	.splice_read	   = tcp_splice_read,
1010 	.read_sock	   = tcp_read_sock,
1011 	.sendmsg_locked    = tcp_sendmsg_locked,
1012 	.sendpage_locked   = tcp_sendpage_locked,
1013 	.peek_len	   = tcp_peek_len,
1014 #ifdef CONFIG_COMPAT
1015 	.compat_setsockopt = compat_sock_common_setsockopt,
1016 	.compat_getsockopt = compat_sock_common_getsockopt,
1017 	.compat_ioctl	   = inet_compat_ioctl,
1018 #endif
1019 	.set_rcvlowat	   = tcp_set_rcvlowat,
1020 };
1021 EXPORT_SYMBOL(inet_stream_ops);
1022 
1023 const struct proto_ops inet_dgram_ops = {
1024 	.family		   = PF_INET,
1025 	.owner		   = THIS_MODULE,
1026 	.release	   = inet_release,
1027 	.bind		   = inet_bind,
1028 	.connect	   = inet_dgram_connect,
1029 	.socketpair	   = sock_no_socketpair,
1030 	.accept		   = sock_no_accept,
1031 	.getname	   = inet_getname,
1032 	.poll		   = udp_poll,
1033 	.ioctl		   = inet_ioctl,
1034 	.gettstamp	   = sock_gettstamp,
1035 	.listen		   = sock_no_listen,
1036 	.shutdown	   = inet_shutdown,
1037 	.setsockopt	   = sock_common_setsockopt,
1038 	.getsockopt	   = sock_common_getsockopt,
1039 	.sendmsg	   = inet_sendmsg,
1040 	.recvmsg	   = inet_recvmsg,
1041 	.mmap		   = sock_no_mmap,
1042 	.sendpage	   = inet_sendpage,
1043 	.set_peek_off	   = sk_set_peek_off,
1044 #ifdef CONFIG_COMPAT
1045 	.compat_setsockopt = compat_sock_common_setsockopt,
1046 	.compat_getsockopt = compat_sock_common_getsockopt,
1047 	.compat_ioctl	   = inet_compat_ioctl,
1048 #endif
1049 };
1050 EXPORT_SYMBOL(inet_dgram_ops);
1051 
1052 /*
1053  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
1054  * udp_poll
1055  */
1056 static const struct proto_ops inet_sockraw_ops = {
1057 	.family		   = PF_INET,
1058 	.owner		   = THIS_MODULE,
1059 	.release	   = inet_release,
1060 	.bind		   = inet_bind,
1061 	.connect	   = inet_dgram_connect,
1062 	.socketpair	   = sock_no_socketpair,
1063 	.accept		   = sock_no_accept,
1064 	.getname	   = inet_getname,
1065 	.poll		   = datagram_poll,
1066 	.ioctl		   = inet_ioctl,
1067 	.gettstamp	   = sock_gettstamp,
1068 	.listen		   = sock_no_listen,
1069 	.shutdown	   = inet_shutdown,
1070 	.setsockopt	   = sock_common_setsockopt,
1071 	.getsockopt	   = sock_common_getsockopt,
1072 	.sendmsg	   = inet_sendmsg,
1073 	.recvmsg	   = inet_recvmsg,
1074 	.mmap		   = sock_no_mmap,
1075 	.sendpage	   = inet_sendpage,
1076 #ifdef CONFIG_COMPAT
1077 	.compat_setsockopt = compat_sock_common_setsockopt,
1078 	.compat_getsockopt = compat_sock_common_getsockopt,
1079 	.compat_ioctl	   = inet_compat_ioctl,
1080 #endif
1081 };
1082 
1083 static const struct net_proto_family inet_family_ops = {
1084 	.family = PF_INET,
1085 	.create = inet_create,
1086 	.owner	= THIS_MODULE,
1087 };
1088 
1089 /* Upon startup we insert all the elements in inetsw_array[] into
1090  * the linked list inetsw.
1091  */
1092 static struct inet_protosw inetsw_array[] =
1093 {
1094 	{
1095 		.type =       SOCK_STREAM,
1096 		.protocol =   IPPROTO_TCP,
1097 		.prot =       &tcp_prot,
1098 		.ops =        &inet_stream_ops,
1099 		.flags =      INET_PROTOSW_PERMANENT |
1100 			      INET_PROTOSW_ICSK,
1101 	},
1102 
1103 	{
1104 		.type =       SOCK_DGRAM,
1105 		.protocol =   IPPROTO_UDP,
1106 		.prot =       &udp_prot,
1107 		.ops =        &inet_dgram_ops,
1108 		.flags =      INET_PROTOSW_PERMANENT,
1109        },
1110 
1111        {
1112 		.type =       SOCK_DGRAM,
1113 		.protocol =   IPPROTO_ICMP,
1114 		.prot =       &ping_prot,
1115 		.ops =        &inet_sockraw_ops,
1116 		.flags =      INET_PROTOSW_REUSE,
1117        },
1118 
1119        {
1120 	       .type =       SOCK_RAW,
1121 	       .protocol =   IPPROTO_IP,	/* wild card */
1122 	       .prot =       &raw_prot,
1123 	       .ops =        &inet_sockraw_ops,
1124 	       .flags =      INET_PROTOSW_REUSE,
1125        }
1126 };
1127 
1128 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
1129 
inet_register_protosw(struct inet_protosw * p)1130 void inet_register_protosw(struct inet_protosw *p)
1131 {
1132 	struct list_head *lh;
1133 	struct inet_protosw *answer;
1134 	int protocol = p->protocol;
1135 	struct list_head *last_perm;
1136 
1137 	spin_lock_bh(&inetsw_lock);
1138 
1139 	if (p->type >= SOCK_MAX)
1140 		goto out_illegal;
1141 
1142 	/* If we are trying to override a permanent protocol, bail. */
1143 	last_perm = &inetsw[p->type];
1144 	list_for_each(lh, &inetsw[p->type]) {
1145 		answer = list_entry(lh, struct inet_protosw, list);
1146 		/* Check only the non-wild match. */
1147 		if ((INET_PROTOSW_PERMANENT & answer->flags) == 0)
1148 			break;
1149 		if (protocol == answer->protocol)
1150 			goto out_permanent;
1151 		last_perm = lh;
1152 	}
1153 
1154 	/* Add the new entry after the last permanent entry if any, so that
1155 	 * the new entry does not override a permanent entry when matched with
1156 	 * a wild-card protocol. But it is allowed to override any existing
1157 	 * non-permanent entry.  This means that when we remove this entry, the
1158 	 * system automatically returns to the old behavior.
1159 	 */
1160 	list_add_rcu(&p->list, last_perm);
1161 out:
1162 	spin_unlock_bh(&inetsw_lock);
1163 
1164 	return;
1165 
1166 out_permanent:
1167 	pr_err("Attempt to override permanent protocol %d\n", protocol);
1168 	goto out;
1169 
1170 out_illegal:
1171 	pr_err("Ignoring attempt to register invalid socket type %d\n",
1172 	       p->type);
1173 	goto out;
1174 }
1175 EXPORT_SYMBOL(inet_register_protosw);
1176 
inet_unregister_protosw(struct inet_protosw * p)1177 void inet_unregister_protosw(struct inet_protosw *p)
1178 {
1179 	if (INET_PROTOSW_PERMANENT & p->flags) {
1180 		pr_err("Attempt to unregister permanent protocol %d\n",
1181 		       p->protocol);
1182 	} else {
1183 		spin_lock_bh(&inetsw_lock);
1184 		list_del_rcu(&p->list);
1185 		spin_unlock_bh(&inetsw_lock);
1186 
1187 		synchronize_net();
1188 	}
1189 }
1190 EXPORT_SYMBOL(inet_unregister_protosw);
1191 
inet_sk_reselect_saddr(struct sock * sk)1192 static int inet_sk_reselect_saddr(struct sock *sk)
1193 {
1194 	struct inet_sock *inet = inet_sk(sk);
1195 	__be32 old_saddr = inet->inet_saddr;
1196 	__be32 daddr = inet->inet_daddr;
1197 	struct flowi4 *fl4;
1198 	struct rtable *rt;
1199 	__be32 new_saddr;
1200 	struct ip_options_rcu *inet_opt;
1201 
1202 	inet_opt = rcu_dereference_protected(inet->inet_opt,
1203 					     lockdep_sock_is_held(sk));
1204 	if (inet_opt && inet_opt->opt.srr)
1205 		daddr = inet_opt->opt.faddr;
1206 
1207 	/* Query new route. */
1208 	fl4 = &inet->cork.fl.u.ip4;
1209 	rt = ip_route_connect(fl4, daddr, 0, RT_CONN_FLAGS(sk),
1210 			      sk->sk_bound_dev_if, sk->sk_protocol,
1211 			      inet->inet_sport, inet->inet_dport, sk);
1212 	if (IS_ERR(rt))
1213 		return PTR_ERR(rt);
1214 
1215 	sk_setup_caps(sk, &rt->dst);
1216 
1217 	new_saddr = fl4->saddr;
1218 
1219 	if (new_saddr == old_saddr)
1220 		return 0;
1221 
1222 	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) > 1) {
1223 		pr_info("%s(): shifting inet->saddr from %pI4 to %pI4\n",
1224 			__func__, &old_saddr, &new_saddr);
1225 	}
1226 
1227 	inet->inet_saddr = inet->inet_rcv_saddr = new_saddr;
1228 
1229 	/*
1230 	 * XXX The only one ugly spot where we need to
1231 	 * XXX really change the sockets identity after
1232 	 * XXX it has entered the hashes. -DaveM
1233 	 *
1234 	 * Besides that, it does not check for connection
1235 	 * uniqueness. Wait for troubles.
1236 	 */
1237 	return __sk_prot_rehash(sk);
1238 }
1239 
inet_sk_rebuild_header(struct sock * sk)1240 int inet_sk_rebuild_header(struct sock *sk)
1241 {
1242 	struct inet_sock *inet = inet_sk(sk);
1243 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1244 	__be32 daddr;
1245 	struct ip_options_rcu *inet_opt;
1246 	struct flowi4 *fl4;
1247 	int err;
1248 
1249 	/* Route is OK, nothing to do. */
1250 	if (rt)
1251 		return 0;
1252 
1253 	/* Reroute. */
1254 	rcu_read_lock();
1255 	inet_opt = rcu_dereference(inet->inet_opt);
1256 	daddr = inet->inet_daddr;
1257 	if (inet_opt && inet_opt->opt.srr)
1258 		daddr = inet_opt->opt.faddr;
1259 	rcu_read_unlock();
1260 	fl4 = &inet->cork.fl.u.ip4;
1261 	rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, inet->inet_saddr,
1262 				   inet->inet_dport, inet->inet_sport,
1263 				   sk->sk_protocol, RT_CONN_FLAGS(sk),
1264 				   sk->sk_bound_dev_if);
1265 	if (!IS_ERR(rt)) {
1266 		err = 0;
1267 		sk_setup_caps(sk, &rt->dst);
1268 	} else {
1269 		err = PTR_ERR(rt);
1270 
1271 		/* Routing failed... */
1272 		sk->sk_route_caps = 0;
1273 		/*
1274 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1275 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1276 		 */
1277 		if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_ip_dynaddr) ||
1278 		    sk->sk_state != TCP_SYN_SENT ||
1279 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1280 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1281 			sk->sk_err_soft = -err;
1282 	}
1283 
1284 	return err;
1285 }
1286 EXPORT_SYMBOL(inet_sk_rebuild_header);
1287 
inet_sk_set_state(struct sock * sk,int state)1288 void inet_sk_set_state(struct sock *sk, int state)
1289 {
1290 	trace_inet_sock_set_state(sk, sk->sk_state, state);
1291 	sk->sk_state = state;
1292 }
1293 EXPORT_SYMBOL(inet_sk_set_state);
1294 
inet_sk_state_store(struct sock * sk,int newstate)1295 void inet_sk_state_store(struct sock *sk, int newstate)
1296 {
1297 	trace_inet_sock_set_state(sk, sk->sk_state, newstate);
1298 	smp_store_release(&sk->sk_state, newstate);
1299 }
1300 
inet_gso_segment(struct sk_buff * skb,netdev_features_t features)1301 struct sk_buff *inet_gso_segment(struct sk_buff *skb,
1302 				 netdev_features_t features)
1303 {
1304 	bool udpfrag = false, fixedid = false, gso_partial, encap;
1305 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1306 	const struct net_offload *ops;
1307 	unsigned int offset = 0;
1308 	struct iphdr *iph;
1309 	int proto, tot_len;
1310 	int nhoff;
1311 	int ihl;
1312 	int id;
1313 
1314 	skb_reset_network_header(skb);
1315 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
1316 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1317 		goto out;
1318 
1319 	iph = ip_hdr(skb);
1320 	ihl = iph->ihl * 4;
1321 	if (ihl < sizeof(*iph))
1322 		goto out;
1323 
1324 	id = ntohs(iph->id);
1325 	proto = iph->protocol;
1326 
1327 	/* Warning: after this point, iph might be no longer valid */
1328 	if (unlikely(!pskb_may_pull(skb, ihl)))
1329 		goto out;
1330 	__skb_pull(skb, ihl);
1331 
1332 	encap = SKB_GSO_CB(skb)->encap_level > 0;
1333 	if (encap)
1334 		features &= skb->dev->hw_enc_features;
1335 	SKB_GSO_CB(skb)->encap_level += ihl;
1336 
1337 	skb_reset_transport_header(skb);
1338 
1339 	segs = ERR_PTR(-EPROTONOSUPPORT);
1340 
1341 	if (!skb->encapsulation || encap) {
1342 		udpfrag = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP);
1343 		fixedid = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TCP_FIXEDID);
1344 
1345 		/* fixed ID is invalid if DF bit is not set */
1346 		if (fixedid && !(ip_hdr(skb)->frag_off & htons(IP_DF)))
1347 			goto out;
1348 	}
1349 
1350 	ops = rcu_dereference(inet_offloads[proto]);
1351 	if (likely(ops && ops->callbacks.gso_segment)) {
1352 		segs = ops->callbacks.gso_segment(skb, features);
1353 		if (!segs)
1354 			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;
1355 	}
1356 
1357 	if (IS_ERR_OR_NULL(segs))
1358 		goto out;
1359 
1360 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
1361 
1362 	skb = segs;
1363 	do {
1364 		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);
1365 		if (udpfrag) {
1366 			iph->frag_off = htons(offset >> 3);
1367 			if (skb->next)
1368 				iph->frag_off |= htons(IP_MF);
1369 			offset += skb->len - nhoff - ihl;
1370 			tot_len = skb->len - nhoff;
1371 		} else if (skb_is_gso(skb)) {
1372 			if (!fixedid) {
1373 				iph->id = htons(id);
1374 				id += skb_shinfo(skb)->gso_segs;
1375 			}
1376 
1377 			if (gso_partial)
1378 				tot_len = skb_shinfo(skb)->gso_size +
1379 					  SKB_GSO_CB(skb)->data_offset +
1380 					  skb->head - (unsigned char *)iph;
1381 			else
1382 				tot_len = skb->len - nhoff;
1383 		} else {
1384 			if (!fixedid)
1385 				iph->id = htons(id++);
1386 			tot_len = skb->len - nhoff;
1387 		}
1388 		iph->tot_len = htons(tot_len);
1389 		ip_send_check(iph);
1390 		if (encap)
1391 			skb_reset_inner_headers(skb);
1392 		skb->network_header = (u8 *)iph - skb->head;
1393 		skb_reset_mac_len(skb);
1394 	} while ((skb = skb->next));
1395 
1396 out:
1397 	return segs;
1398 }
1399 EXPORT_SYMBOL(inet_gso_segment);
1400 
ipip_gso_segment(struct sk_buff * skb,netdev_features_t features)1401 static struct sk_buff *ipip_gso_segment(struct sk_buff *skb,
1402 					netdev_features_t features)
1403 {
1404 	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))
1405 		return ERR_PTR(-EINVAL);
1406 
1407 	return inet_gso_segment(skb, features);
1408 }
1409 
1410 INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *,
1411 							   struct sk_buff *));
1412 INDIRECT_CALLABLE_DECLARE(struct sk_buff *udp4_gro_receive(struct list_head *,
1413 							   struct sk_buff *));
inet_gro_receive(struct list_head * head,struct sk_buff * skb)1414 struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
1415 {
1416 	const struct net_offload *ops;
1417 	struct sk_buff *pp = NULL;
1418 	const struct iphdr *iph;
1419 	struct sk_buff *p;
1420 	unsigned int hlen;
1421 	unsigned int off;
1422 	unsigned int id;
1423 	int flush = 1;
1424 	int proto;
1425 
1426 	off = skb_gro_offset(skb);
1427 	hlen = off + sizeof(*iph);
1428 	iph = skb_gro_header_fast(skb, off);
1429 	if (skb_gro_header_hard(skb, hlen)) {
1430 		iph = skb_gro_header_slow(skb, hlen, off);
1431 		if (unlikely(!iph))
1432 			goto out;
1433 	}
1434 
1435 	proto = iph->protocol;
1436 
1437 	rcu_read_lock();
1438 	ops = rcu_dereference(inet_offloads[proto]);
1439 	if (!ops || !ops->callbacks.gro_receive)
1440 		goto out_unlock;
1441 
1442 	if (*(u8 *)iph != 0x45)
1443 		goto out_unlock;
1444 
1445 	if (ip_is_fragment(iph))
1446 		goto out_unlock;
1447 
1448 	if (unlikely(ip_fast_csum((u8 *)iph, 5)))
1449 		goto out_unlock;
1450 
1451 	id = ntohl(*(__be32 *)&iph->id);
1452 	flush = (u16)((ntohl(*(__be32 *)iph) ^ skb_gro_len(skb)) | (id & ~IP_DF));
1453 	id >>= 16;
1454 
1455 	list_for_each_entry(p, head, list) {
1456 		struct iphdr *iph2;
1457 		u16 flush_id;
1458 
1459 		if (!NAPI_GRO_CB(p)->same_flow)
1460 			continue;
1461 
1462 		iph2 = (struct iphdr *)(p->data + off);
1463 		/* The above works because, with the exception of the top
1464 		 * (inner most) layer, we only aggregate pkts with the same
1465 		 * hdr length so all the hdrs we'll need to verify will start
1466 		 * at the same offset.
1467 		 */
1468 		if ((iph->protocol ^ iph2->protocol) |
1469 		    ((__force u32)iph->saddr ^ (__force u32)iph2->saddr) |
1470 		    ((__force u32)iph->daddr ^ (__force u32)iph2->daddr)) {
1471 			NAPI_GRO_CB(p)->same_flow = 0;
1472 			continue;
1473 		}
1474 
1475 		/* All fields must match except length and checksum. */
1476 		NAPI_GRO_CB(p)->flush |=
1477 			(iph->ttl ^ iph2->ttl) |
1478 			(iph->tos ^ iph2->tos) |
1479 			((iph->frag_off ^ iph2->frag_off) & htons(IP_DF));
1480 
1481 		NAPI_GRO_CB(p)->flush |= flush;
1482 
1483 		/* We need to store of the IP ID check to be included later
1484 		 * when we can verify that this packet does in fact belong
1485 		 * to a given flow.
1486 		 */
1487 		flush_id = (u16)(id - ntohs(iph2->id));
1488 
1489 		/* This bit of code makes it much easier for us to identify
1490 		 * the cases where we are doing atomic vs non-atomic IP ID
1491 		 * checks.  Specifically an atomic check can return IP ID
1492 		 * values 0 - 0xFFFF, while a non-atomic check can only
1493 		 * return 0 or 0xFFFF.
1494 		 */
1495 		if (!NAPI_GRO_CB(p)->is_atomic ||
1496 		    !(iph->frag_off & htons(IP_DF))) {
1497 			flush_id ^= NAPI_GRO_CB(p)->count;
1498 			flush_id = flush_id ? 0xFFFF : 0;
1499 		}
1500 
1501 		/* If the previous IP ID value was based on an atomic
1502 		 * datagram we can overwrite the value and ignore it.
1503 		 */
1504 		if (NAPI_GRO_CB(skb)->is_atomic)
1505 			NAPI_GRO_CB(p)->flush_id = flush_id;
1506 		else
1507 			NAPI_GRO_CB(p)->flush_id |= flush_id;
1508 	}
1509 
1510 	NAPI_GRO_CB(skb)->is_atomic = !!(iph->frag_off & htons(IP_DF));
1511 	NAPI_GRO_CB(skb)->flush |= flush;
1512 	skb_set_network_header(skb, off);
1513 	/* The above will be needed by the transport layer if there is one
1514 	 * immediately following this IP hdr.
1515 	 */
1516 
1517 	/* Note : No need to call skb_gro_postpull_rcsum() here,
1518 	 * as we already checked checksum over ipv4 header was 0
1519 	 */
1520 	skb_gro_pull(skb, sizeof(*iph));
1521 	skb_set_transport_header(skb, skb_gro_offset(skb));
1522 
1523 	pp = indirect_call_gro_receive(tcp4_gro_receive, udp4_gro_receive,
1524 				       ops->callbacks.gro_receive, head, skb);
1525 
1526 out_unlock:
1527 	rcu_read_unlock();
1528 
1529 out:
1530 	skb_gro_flush_final(skb, pp, flush);
1531 
1532 	return pp;
1533 }
1534 EXPORT_SYMBOL(inet_gro_receive);
1535 
ipip_gro_receive(struct list_head * head,struct sk_buff * skb)1536 static struct sk_buff *ipip_gro_receive(struct list_head *head,
1537 					struct sk_buff *skb)
1538 {
1539 	if (NAPI_GRO_CB(skb)->encap_mark) {
1540 		NAPI_GRO_CB(skb)->flush = 1;
1541 		return NULL;
1542 	}
1543 
1544 	NAPI_GRO_CB(skb)->encap_mark = 1;
1545 
1546 	return inet_gro_receive(head, skb);
1547 }
1548 
1549 #define SECONDS_PER_DAY	86400
1550 
1551 /* inet_current_timestamp - Return IP network timestamp
1552  *
1553  * Return milliseconds since midnight in network byte order.
1554  */
inet_current_timestamp(void)1555 __be32 inet_current_timestamp(void)
1556 {
1557 	u32 secs;
1558 	u32 msecs;
1559 	struct timespec64 ts;
1560 
1561 	ktime_get_real_ts64(&ts);
1562 
1563 	/* Get secs since midnight. */
1564 	(void)div_u64_rem(ts.tv_sec, SECONDS_PER_DAY, &secs);
1565 	/* Convert to msecs. */
1566 	msecs = secs * MSEC_PER_SEC;
1567 	/* Convert nsec to msec. */
1568 	msecs += (u32)ts.tv_nsec / NSEC_PER_MSEC;
1569 
1570 	/* Convert to network byte order. */
1571 	return htonl(msecs);
1572 }
1573 EXPORT_SYMBOL(inet_current_timestamp);
1574 
inet_recv_error(struct sock * sk,struct msghdr * msg,int len,int * addr_len)1575 int inet_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
1576 {
1577 	unsigned int family = READ_ONCE(sk->sk_family);
1578 
1579 	if (family == AF_INET)
1580 		return ip_recv_error(sk, msg, len, addr_len);
1581 #if IS_ENABLED(CONFIG_IPV6)
1582 	if (family == AF_INET6)
1583 		return pingv6_ops.ipv6_recv_error(sk, msg, len, addr_len);
1584 #endif
1585 	return -EINVAL;
1586 }
1587 
1588 INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *, int));
1589 INDIRECT_CALLABLE_DECLARE(int udp4_gro_complete(struct sk_buff *, int));
inet_gro_complete(struct sk_buff * skb,int nhoff)1590 int inet_gro_complete(struct sk_buff *skb, int nhoff)
1591 {
1592 	__be16 newlen = htons(skb->len - nhoff);
1593 	struct iphdr *iph = (struct iphdr *)(skb->data + nhoff);
1594 	const struct net_offload *ops;
1595 	int proto = iph->protocol;
1596 	int err = -ENOSYS;
1597 
1598 	if (skb->encapsulation) {
1599 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IP));
1600 		skb_set_inner_network_header(skb, nhoff);
1601 	}
1602 
1603 	csum_replace2(&iph->check, iph->tot_len, newlen);
1604 	iph->tot_len = newlen;
1605 
1606 	rcu_read_lock();
1607 	ops = rcu_dereference(inet_offloads[proto]);
1608 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
1609 		goto out_unlock;
1610 
1611 	/* Only need to add sizeof(*iph) to get to the next hdr below
1612 	 * because any hdr with option will have been flushed in
1613 	 * inet_gro_receive().
1614 	 */
1615 	err = INDIRECT_CALL_2(ops->callbacks.gro_complete,
1616 			      tcp4_gro_complete, udp4_gro_complete,
1617 			      skb, nhoff + sizeof(*iph));
1618 
1619 out_unlock:
1620 	rcu_read_unlock();
1621 
1622 	return err;
1623 }
1624 EXPORT_SYMBOL(inet_gro_complete);
1625 
ipip_gro_complete(struct sk_buff * skb,int nhoff)1626 static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
1627 {
1628 	skb->encapsulation = 1;
1629 	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;
1630 	return inet_gro_complete(skb, nhoff);
1631 }
1632 
inet_ctl_sock_create(struct sock ** sk,unsigned short family,unsigned short type,unsigned char protocol,struct net * net)1633 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1634 			 unsigned short type, unsigned char protocol,
1635 			 struct net *net)
1636 {
1637 	struct socket *sock;
1638 	int rc = sock_create_kern(net, family, type, protocol, &sock);
1639 
1640 	if (rc == 0) {
1641 		*sk = sock->sk;
1642 		(*sk)->sk_allocation = GFP_ATOMIC;
1643 		/*
1644 		 * Unhash it so that IP input processing does not even see it,
1645 		 * we do not wish this socket to see incoming packets.
1646 		 */
1647 		(*sk)->sk_prot->unhash(*sk);
1648 	}
1649 	return rc;
1650 }
1651 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1652 
snmp_get_cpu_field(void __percpu * mib,int cpu,int offt)1653 u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
1654 {
1655 	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
1656 }
1657 EXPORT_SYMBOL_GPL(snmp_get_cpu_field);
1658 
snmp_fold_field(void __percpu * mib,int offt)1659 unsigned long snmp_fold_field(void __percpu *mib, int offt)
1660 {
1661 	unsigned long res = 0;
1662 	int i;
1663 
1664 	for_each_possible_cpu(i)
1665 		res += snmp_get_cpu_field(mib, i, offt);
1666 	return res;
1667 }
1668 EXPORT_SYMBOL_GPL(snmp_fold_field);
1669 
1670 #if BITS_PER_LONG==32
1671 
snmp_get_cpu_field64(void __percpu * mib,int cpu,int offt,size_t syncp_offset)1672 u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offt,
1673 			 size_t syncp_offset)
1674 {
1675 	void *bhptr;
1676 	struct u64_stats_sync *syncp;
1677 	u64 v;
1678 	unsigned int start;
1679 
1680 	bhptr = per_cpu_ptr(mib, cpu);
1681 	syncp = (struct u64_stats_sync *)(bhptr + syncp_offset);
1682 	do {
1683 		start = u64_stats_fetch_begin_irq(syncp);
1684 		v = *(((u64 *)bhptr) + offt);
1685 	} while (u64_stats_fetch_retry_irq(syncp, start));
1686 
1687 	return v;
1688 }
1689 EXPORT_SYMBOL_GPL(snmp_get_cpu_field64);
1690 
snmp_fold_field64(void __percpu * mib,int offt,size_t syncp_offset)1691 u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_offset)
1692 {
1693 	u64 res = 0;
1694 	int cpu;
1695 
1696 	for_each_possible_cpu(cpu) {
1697 		res += snmp_get_cpu_field64(mib, cpu, offt, syncp_offset);
1698 	}
1699 	return res;
1700 }
1701 EXPORT_SYMBOL_GPL(snmp_fold_field64);
1702 #endif
1703 
1704 #ifdef CONFIG_IP_MULTICAST
1705 static const struct net_protocol igmp_protocol = {
1706 	.handler =	igmp_rcv,
1707 	.netns_ok =	1,
1708 };
1709 #endif
1710 
1711 static const struct net_protocol tcp_protocol = {
1712 	.handler	=	tcp_v4_rcv,
1713 	.err_handler	=	tcp_v4_err,
1714 	.no_policy	=	1,
1715 	.netns_ok	=	1,
1716 	.icmp_strict_tag_validation = 1,
1717 };
1718 
1719 static const struct net_protocol udp_protocol = {
1720 	.handler =	udp_rcv,
1721 	.err_handler =	udp_err,
1722 	.no_policy =	1,
1723 	.netns_ok =	1,
1724 };
1725 
1726 static const struct net_protocol icmp_protocol = {
1727 	.handler =	icmp_rcv,
1728 	.err_handler =	icmp_err,
1729 	.no_policy =	1,
1730 	.netns_ok =	1,
1731 };
1732 
ipv4_mib_init_net(struct net * net)1733 static __net_init int ipv4_mib_init_net(struct net *net)
1734 {
1735 	int i;
1736 
1737 	net->mib.tcp_statistics = alloc_percpu(struct tcp_mib);
1738 	if (!net->mib.tcp_statistics)
1739 		goto err_tcp_mib;
1740 	net->mib.ip_statistics = alloc_percpu(struct ipstats_mib);
1741 	if (!net->mib.ip_statistics)
1742 		goto err_ip_mib;
1743 
1744 	for_each_possible_cpu(i) {
1745 		struct ipstats_mib *af_inet_stats;
1746 		af_inet_stats = per_cpu_ptr(net->mib.ip_statistics, i);
1747 		u64_stats_init(&af_inet_stats->syncp);
1748 	}
1749 
1750 	net->mib.net_statistics = alloc_percpu(struct linux_mib);
1751 	if (!net->mib.net_statistics)
1752 		goto err_net_mib;
1753 	net->mib.udp_statistics = alloc_percpu(struct udp_mib);
1754 	if (!net->mib.udp_statistics)
1755 		goto err_udp_mib;
1756 	net->mib.udplite_statistics = alloc_percpu(struct udp_mib);
1757 	if (!net->mib.udplite_statistics)
1758 		goto err_udplite_mib;
1759 	net->mib.icmp_statistics = alloc_percpu(struct icmp_mib);
1760 	if (!net->mib.icmp_statistics)
1761 		goto err_icmp_mib;
1762 	net->mib.icmpmsg_statistics = kzalloc(sizeof(struct icmpmsg_mib),
1763 					      GFP_KERNEL);
1764 	if (!net->mib.icmpmsg_statistics)
1765 		goto err_icmpmsg_mib;
1766 
1767 	tcp_mib_init(net);
1768 	return 0;
1769 
1770 err_icmpmsg_mib:
1771 	free_percpu(net->mib.icmp_statistics);
1772 err_icmp_mib:
1773 	free_percpu(net->mib.udplite_statistics);
1774 err_udplite_mib:
1775 	free_percpu(net->mib.udp_statistics);
1776 err_udp_mib:
1777 	free_percpu(net->mib.net_statistics);
1778 err_net_mib:
1779 	free_percpu(net->mib.ip_statistics);
1780 err_ip_mib:
1781 	free_percpu(net->mib.tcp_statistics);
1782 err_tcp_mib:
1783 	return -ENOMEM;
1784 }
1785 
ipv4_mib_exit_net(struct net * net)1786 static __net_exit void ipv4_mib_exit_net(struct net *net)
1787 {
1788 	kfree(net->mib.icmpmsg_statistics);
1789 	free_percpu(net->mib.icmp_statistics);
1790 	free_percpu(net->mib.udplite_statistics);
1791 	free_percpu(net->mib.udp_statistics);
1792 	free_percpu(net->mib.net_statistics);
1793 	free_percpu(net->mib.ip_statistics);
1794 	free_percpu(net->mib.tcp_statistics);
1795 }
1796 
1797 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1798 	.init = ipv4_mib_init_net,
1799 	.exit = ipv4_mib_exit_net,
1800 };
1801 
init_ipv4_mibs(void)1802 static int __init init_ipv4_mibs(void)
1803 {
1804 	return register_pernet_subsys(&ipv4_mib_ops);
1805 }
1806 
inet_init_net(struct net * net)1807 static __net_init int inet_init_net(struct net *net)
1808 {
1809 	/*
1810 	 * Set defaults for local port range
1811 	 */
1812 	seqlock_init(&net->ipv4.ip_local_ports.lock);
1813 	net->ipv4.ip_local_ports.range[0] =  32768;
1814 	net->ipv4.ip_local_ports.range[1] =  60999;
1815 
1816 	seqlock_init(&net->ipv4.ping_group_range.lock);
1817 	/*
1818 	 * Sane defaults - nobody may create ping sockets.
1819 	 * Boot scripts should set this to distro-specific group.
1820 	 */
1821 	net->ipv4.ping_group_range.range[0] = make_kgid(&init_user_ns, 1);
1822 	net->ipv4.ping_group_range.range[1] = make_kgid(&init_user_ns, 0);
1823 
1824 	/* Default values for sysctl-controlled parameters.
1825 	 * We set them here, in case sysctl is not compiled.
1826 	 */
1827 	net->ipv4.sysctl_ip_default_ttl = IPDEFTTL;
1828 	net->ipv4.sysctl_ip_fwd_update_priority = 1;
1829 	net->ipv4.sysctl_ip_dynaddr = 0;
1830 	net->ipv4.sysctl_ip_early_demux = 1;
1831 	net->ipv4.sysctl_udp_early_demux = 1;
1832 	net->ipv4.sysctl_tcp_early_demux = 1;
1833 #ifdef CONFIG_SYSCTL
1834 	net->ipv4.sysctl_ip_prot_sock = PROT_SOCK;
1835 #endif
1836 
1837 	/* Some igmp sysctl, whose values are always used */
1838 	net->ipv4.sysctl_igmp_max_memberships = 20;
1839 	net->ipv4.sysctl_igmp_max_msf = 10;
1840 	/* IGMP reports for link-local multicast groups are enabled by default */
1841 	net->ipv4.sysctl_igmp_llm_reports = 1;
1842 	net->ipv4.sysctl_igmp_qrv = 2;
1843 
1844 	return 0;
1845 }
1846 
1847 static __net_initdata struct pernet_operations af_inet_ops = {
1848 	.init = inet_init_net,
1849 };
1850 
init_inet_pernet_ops(void)1851 static int __init init_inet_pernet_ops(void)
1852 {
1853 	return register_pernet_subsys(&af_inet_ops);
1854 }
1855 
1856 static int ipv4_proc_init(void);
1857 
1858 /*
1859  *	IP protocol layer initialiser
1860  */
1861 
1862 static struct packet_offload ip_packet_offload __read_mostly = {
1863 	.type = cpu_to_be16(ETH_P_IP),
1864 	.callbacks = {
1865 		.gso_segment = inet_gso_segment,
1866 		.gro_receive = inet_gro_receive,
1867 		.gro_complete = inet_gro_complete,
1868 	},
1869 };
1870 
1871 static const struct net_offload ipip_offload = {
1872 	.callbacks = {
1873 		.gso_segment	= ipip_gso_segment,
1874 		.gro_receive	= ipip_gro_receive,
1875 		.gro_complete	= ipip_gro_complete,
1876 	},
1877 };
1878 
ipip_offload_init(void)1879 static int __init ipip_offload_init(void)
1880 {
1881 	return inet_add_offload(&ipip_offload, IPPROTO_IPIP);
1882 }
1883 
ipv4_offload_init(void)1884 static int __init ipv4_offload_init(void)
1885 {
1886 	/*
1887 	 * Add offloads
1888 	 */
1889 	if (udpv4_offload_init() < 0)
1890 		pr_crit("%s: Cannot add UDP protocol offload\n", __func__);
1891 	if (tcpv4_offload_init() < 0)
1892 		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
1893 	if (ipip_offload_init() < 0)
1894 		pr_crit("%s: Cannot add IPIP protocol offload\n", __func__);
1895 
1896 	dev_add_offload(&ip_packet_offload);
1897 	return 0;
1898 }
1899 
1900 fs_initcall(ipv4_offload_init);
1901 
1902 static struct packet_type ip_packet_type __read_mostly = {
1903 	.type = cpu_to_be16(ETH_P_IP),
1904 	.func = ip_rcv,
1905 	.list_func = ip_list_rcv,
1906 };
1907 
inet_init(void)1908 static int __init inet_init(void)
1909 {
1910 	struct inet_protosw *q;
1911 	struct list_head *r;
1912 	int rc = -EINVAL;
1913 
1914 	sock_skb_cb_check_size(sizeof(struct inet_skb_parm));
1915 
1916 	rc = proto_register(&tcp_prot, 1);
1917 	if (rc)
1918 		goto out;
1919 
1920 	rc = proto_register(&udp_prot, 1);
1921 	if (rc)
1922 		goto out_unregister_tcp_proto;
1923 
1924 	rc = proto_register(&raw_prot, 1);
1925 	if (rc)
1926 		goto out_unregister_udp_proto;
1927 
1928 	rc = proto_register(&ping_prot, 1);
1929 	if (rc)
1930 		goto out_unregister_raw_proto;
1931 
1932 	/*
1933 	 *	Tell SOCKET that we are alive...
1934 	 */
1935 
1936 	(void)sock_register(&inet_family_ops);
1937 
1938 #ifdef CONFIG_SYSCTL
1939 	ip_static_sysctl_init();
1940 #endif
1941 
1942 	/*
1943 	 *	Add all the base protocols.
1944 	 */
1945 
1946 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1947 		pr_crit("%s: Cannot add ICMP protocol\n", __func__);
1948 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1949 		pr_crit("%s: Cannot add UDP protocol\n", __func__);
1950 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1951 		pr_crit("%s: Cannot add TCP protocol\n", __func__);
1952 #ifdef CONFIG_IP_MULTICAST
1953 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1954 		pr_crit("%s: Cannot add IGMP protocol\n", __func__);
1955 #endif
1956 
1957 	/* Register the socket-side information for inet_create. */
1958 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1959 		INIT_LIST_HEAD(r);
1960 
1961 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1962 		inet_register_protosw(q);
1963 
1964 	/*
1965 	 *	Set the ARP module up
1966 	 */
1967 
1968 	arp_init();
1969 
1970 	/*
1971 	 *	Set the IP module up
1972 	 */
1973 
1974 	ip_init();
1975 
1976 	/* Initialise per-cpu ipv4 mibs */
1977 	if (init_ipv4_mibs())
1978 		panic("%s: Cannot init ipv4 mibs\n", __func__);
1979 
1980 	/* Setup TCP slab cache for open requests. */
1981 	tcp_init();
1982 
1983 	/* Setup UDP memory threshold */
1984 	udp_init();
1985 
1986 	/* Add UDP-Lite (RFC 3828) */
1987 	udplite4_register();
1988 
1989 	raw_init();
1990 
1991 	ping_init();
1992 
1993 	/*
1994 	 *	Set the ICMP layer up
1995 	 */
1996 
1997 	if (icmp_init() < 0)
1998 		panic("Failed to create the ICMP control socket.\n");
1999 
2000 	/*
2001 	 *	Initialise the multicast router
2002 	 */
2003 #if defined(CONFIG_IP_MROUTE)
2004 	if (ip_mr_init())
2005 		pr_crit("%s: Cannot init ipv4 mroute\n", __func__);
2006 #endif
2007 
2008 	if (init_inet_pernet_ops())
2009 		pr_crit("%s: Cannot init ipv4 inet pernet ops\n", __func__);
2010 
2011 	ipv4_proc_init();
2012 
2013 	ipfrag_init();
2014 
2015 	dev_add_pack(&ip_packet_type);
2016 
2017 	ip_tunnel_core_init();
2018 
2019 	rc = 0;
2020 out:
2021 	return rc;
2022 out_unregister_raw_proto:
2023 	proto_unregister(&raw_prot);
2024 out_unregister_udp_proto:
2025 	proto_unregister(&udp_prot);
2026 out_unregister_tcp_proto:
2027 	proto_unregister(&tcp_prot);
2028 	goto out;
2029 }
2030 
2031 fs_initcall(inet_init);
2032 
2033 /* ------------------------------------------------------------------------ */
2034 
2035 #ifdef CONFIG_PROC_FS
ipv4_proc_init(void)2036 static int __init ipv4_proc_init(void)
2037 {
2038 	int rc = 0;
2039 
2040 	if (raw_proc_init())
2041 		goto out_raw;
2042 	if (tcp4_proc_init())
2043 		goto out_tcp;
2044 	if (udp4_proc_init())
2045 		goto out_udp;
2046 	if (ping_proc_init())
2047 		goto out_ping;
2048 	if (ip_misc_proc_init())
2049 		goto out_misc;
2050 out:
2051 	return rc;
2052 out_misc:
2053 	ping_proc_exit();
2054 out_ping:
2055 	udp4_proc_exit();
2056 out_udp:
2057 	tcp4_proc_exit();
2058 out_tcp:
2059 	raw_proc_exit();
2060 out_raw:
2061 	rc = -ENOMEM;
2062 	goto out;
2063 }
2064 
2065 #else /* CONFIG_PROC_FS */
ipv4_proc_init(void)2066 static int __init ipv4_proc_init(void)
2067 {
2068 	return 0;
2069 }
2070 #endif /* CONFIG_PROC_FS */
2071