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1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		PF_INET protocol family socket handler.
7  *
8  * Authors:	Ross Biro
9  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
10  *		Florian La Roche, <flla@stud.uni-sb.de>
11  *		Alan Cox, <A.Cox@swansea.ac.uk>
12  *
13  * Changes (see also sock.c)
14  *
15  *		piggy,
16  *		Karl Knutson	:	Socket protocol table
17  *		A.N.Kuznetsov	:	Socket death error in accept().
18  *		John Richardson :	Fix non blocking error in connect()
19  *					so sockets that fail to connect
20  *					don't return -EINPROGRESS.
21  *		Alan Cox	:	Asynchronous I/O support
22  *		Alan Cox	:	Keep correct socket pointer on sock
23  *					structures
24  *					when accept() ed
25  *		Alan Cox	:	Semantics of SO_LINGER aren't state
26  *					moved to close when you look carefully.
27  *					With this fixed and the accept bug fixed
28  *					some RPC stuff seems happier.
29  *		Niibe Yutaka	:	4.4BSD style write async I/O
30  *		Alan Cox,
31  *		Tony Gale 	:	Fixed reuse semantics.
32  *		Alan Cox	:	bind() shouldn't abort existing but dead
33  *					sockets. Stops FTP netin:.. I hope.
34  *		Alan Cox	:	bind() works correctly for RAW sockets.
35  *					Note that FreeBSD at least was broken
36  *					in this respect so be careful with
37  *					compatibility tests...
38  *		Alan Cox	:	routing cache support
39  *		Alan Cox	:	memzero the socket structure for
40  *					compactness.
41  *		Matt Day	:	nonblock connect error handler
42  *		Alan Cox	:	Allow large numbers of pending sockets
43  *					(eg for big web sites), but only if
44  *					specifically application requested.
45  *		Alan Cox	:	New buffering throughout IP. Used
46  *					dumbly.
47  *		Alan Cox	:	New buffering now used smartly.
48  *		Alan Cox	:	BSD rather than common sense
49  *					interpretation of listen.
50  *		Germano Caronni	:	Assorted small races.
51  *		Alan Cox	:	sendmsg/recvmsg basic support.
52  *		Alan Cox	:	Only sendmsg/recvmsg now supported.
53  *		Alan Cox	:	Locked down bind (see security list).
54  *		Alan Cox	:	Loosened bind a little.
55  *		Mike McLagan	:	ADD/DEL DLCI Ioctls
56  *	Willy Konynenberg	:	Transparent proxying support.
57  *		David S. Miller	:	New socket lookup architecture.
58  *					Some other random speedups.
59  *		Cyrus Durgin	:	Cleaned up file for kmod hacks.
60  *		Andi Kleen	:	Fix inet_stream_connect TCP race.
61  *
62  *		This program is free software; you can redistribute it and/or
63  *		modify it under the terms of the GNU General Public License
64  *		as published by the Free Software Foundation; either version
65  *		2 of the License, or (at your option) any later version.
66  */
67 
68 #include <linux/err.h>
69 #include <linux/errno.h>
70 #include <linux/types.h>
71 #include <linux/socket.h>
72 #include <linux/in.h>
73 #include <linux/kernel.h>
74 #include <linux/module.h>
75 #include <linux/sched.h>
76 #include <linux/timer.h>
77 #include <linux/string.h>
78 #include <linux/sockios.h>
79 #include <linux/net.h>
80 #include <linux/capability.h>
81 #include <linux/fcntl.h>
82 #include <linux/mm.h>
83 #include <linux/interrupt.h>
84 #include <linux/stat.h>
85 #include <linux/init.h>
86 #include <linux/poll.h>
87 #include <linux/netfilter_ipv4.h>
88 #include <linux/random.h>
89 
90 #include <asm/uaccess.h>
91 #include <asm/system.h>
92 
93 #include <linux/inet.h>
94 #include <linux/igmp.h>
95 #include <linux/inetdevice.h>
96 #include <linux/netdevice.h>
97 #include <net/checksum.h>
98 #include <net/ip.h>
99 #include <net/protocol.h>
100 #include <net/arp.h>
101 #include <net/route.h>
102 #include <net/ip_fib.h>
103 #include <net/inet_connection_sock.h>
104 #include <net/tcp.h>
105 #include <net/udp.h>
106 #include <net/udplite.h>
107 #include <linux/skbuff.h>
108 #include <net/sock.h>
109 #include <net/raw.h>
110 #include <net/icmp.h>
111 #include <net/ipip.h>
112 #include <net/inet_common.h>
113 #include <net/xfrm.h>
114 #include <net/net_namespace.h>
115 #ifdef CONFIG_IP_MROUTE
116 #include <linux/mroute.h>
117 #endif
118 
119 #ifdef CONFIG_ANDROID_PARANOID_NETWORK
120 #include <linux/android_aid.h>
121 
current_has_network(void)122 static inline int current_has_network(void)
123 {
124 	return in_egroup_p(AID_INET) || capable(CAP_NET_RAW);
125 }
126 #else
current_has_network(void)127 static inline int current_has_network(void)
128 {
129 	return 1;
130 }
131 #endif
132 
133 extern void ip_mc_drop_socket(struct sock *sk);
134 
135 /* The inetsw table contains everything that inet_create needs to
136  * build a new socket.
137  */
138 static struct list_head inetsw[SOCK_MAX];
139 static DEFINE_SPINLOCK(inetsw_lock);
140 
141 struct ipv4_config ipv4_config;
142 
143 EXPORT_SYMBOL(ipv4_config);
144 
145 /* New destruction routine */
146 
inet_sock_destruct(struct sock * sk)147 void inet_sock_destruct(struct sock *sk)
148 {
149 	struct inet_sock *inet = inet_sk(sk);
150 
151 	__skb_queue_purge(&sk->sk_receive_queue);
152 	__skb_queue_purge(&sk->sk_error_queue);
153 
154 	sk_mem_reclaim(sk);
155 
156 	if (sk->sk_type == SOCK_STREAM && sk->sk_state != TCP_CLOSE) {
157 		printk("Attempt to release TCP socket in state %d %p\n",
158 		       sk->sk_state, sk);
159 		return;
160 	}
161 	if (!sock_flag(sk, SOCK_DEAD)) {
162 		printk("Attempt to release alive inet socket %p\n", sk);
163 		return;
164 	}
165 
166 	WARN_ON(atomic_read(&sk->sk_rmem_alloc));
167 	WARN_ON(atomic_read(&sk->sk_wmem_alloc));
168 	WARN_ON(sk->sk_wmem_queued);
169 	WARN_ON(sk->sk_forward_alloc);
170 
171 	kfree(inet->opt);
172 	dst_release(sk->sk_dst_cache);
173 	sk_refcnt_debug_dec(sk);
174 }
175 
176 /*
177  *	The routines beyond this point handle the behaviour of an AF_INET
178  *	socket object. Mostly it punts to the subprotocols of IP to do
179  *	the work.
180  */
181 
182 /*
183  *	Automatically bind an unbound socket.
184  */
185 
inet_autobind(struct sock * sk)186 static int inet_autobind(struct sock *sk)
187 {
188 	struct inet_sock *inet;
189 	/* We may need to bind the socket. */
190 	lock_sock(sk);
191 	inet = inet_sk(sk);
192 	if (!inet->num) {
193 		if (sk->sk_prot->get_port(sk, 0)) {
194 			release_sock(sk);
195 			return -EAGAIN;
196 		}
197 		inet->sport = htons(inet->num);
198 	}
199 	release_sock(sk);
200 	return 0;
201 }
202 
203 /*
204  *	Move a socket into listening state.
205  */
inet_listen(struct socket * sock,int backlog)206 int inet_listen(struct socket *sock, int backlog)
207 {
208 	struct sock *sk = sock->sk;
209 	unsigned char old_state;
210 	int err;
211 
212 	lock_sock(sk);
213 
214 	err = -EINVAL;
215 	if (sock->state != SS_UNCONNECTED || sock->type != SOCK_STREAM)
216 		goto out;
217 
218 	old_state = sk->sk_state;
219 	if (!((1 << old_state) & (TCPF_CLOSE | TCPF_LISTEN)))
220 		goto out;
221 
222 	/* Really, if the socket is already in listen state
223 	 * we can only allow the backlog to be adjusted.
224 	 */
225 	if (old_state != TCP_LISTEN) {
226 		err = inet_csk_listen_start(sk, backlog);
227 		if (err)
228 			goto out;
229 	}
230 	sk->sk_max_ack_backlog = backlog;
231 	err = 0;
232 
233 out:
234 	release_sock(sk);
235 	return err;
236 }
237 
238 u32 inet_ehash_secret __read_mostly;
239 EXPORT_SYMBOL(inet_ehash_secret);
240 
241 /*
242  * inet_ehash_secret must be set exactly once
243  * Instead of using a dedicated spinlock, we (ab)use inetsw_lock
244  */
build_ehash_secret(void)245 void build_ehash_secret(void)
246 {
247 	u32 rnd;
248 	do {
249 		get_random_bytes(&rnd, sizeof(rnd));
250 	} while (rnd == 0);
251 	spin_lock_bh(&inetsw_lock);
252 	if (!inet_ehash_secret)
253 		inet_ehash_secret = rnd;
254 	spin_unlock_bh(&inetsw_lock);
255 }
256 EXPORT_SYMBOL(build_ehash_secret);
257 
inet_netns_ok(struct net * net,int protocol)258 static inline int inet_netns_ok(struct net *net, int protocol)
259 {
260 	int hash;
261 	struct net_protocol *ipprot;
262 
263 	if (net_eq(net, &init_net))
264 		return 1;
265 
266 	hash = protocol & (MAX_INET_PROTOS - 1);
267 	ipprot = rcu_dereference(inet_protos[hash]);
268 
269 	if (ipprot == NULL)
270 		/* raw IP is OK */
271 		return 1;
272 	return ipprot->netns_ok;
273 }
274 
275 
276 /*
277  *	Create an inet socket.
278  */
279 
inet_create(struct net * net,struct socket * sock,int protocol)280 static int inet_create(struct net *net, struct socket *sock, int protocol)
281 {
282 	struct sock *sk;
283 	struct inet_protosw *answer;
284 	struct inet_sock *inet;
285 	struct proto *answer_prot;
286 	unsigned char answer_flags;
287 	char answer_no_check;
288 	int try_loading_module = 0;
289 	int err;
290 
291 	if (!current_has_network())
292 		return -EACCES;
293 
294 	if (unlikely(!inet_ehash_secret))
295 		if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
296 			build_ehash_secret();
297 
298 	sock->state = SS_UNCONNECTED;
299 
300 	/* Look for the requested type/protocol pair. */
301 lookup_protocol:
302 	err = -ESOCKTNOSUPPORT;
303 	rcu_read_lock();
304 	list_for_each_entry_rcu(answer, &inetsw[sock->type], list) {
305 
306 		err = 0;
307 		/* Check the non-wild match. */
308 		if (protocol == answer->protocol) {
309 			if (protocol != IPPROTO_IP)
310 				break;
311 		} else {
312 			/* Check for the two wild cases. */
313 			if (IPPROTO_IP == protocol) {
314 				protocol = answer->protocol;
315 				break;
316 			}
317 			if (IPPROTO_IP == answer->protocol)
318 				break;
319 		}
320 		err = -EPROTONOSUPPORT;
321 	}
322 
323 	if (unlikely(err)) {
324 		if (try_loading_module < 2) {
325 			rcu_read_unlock();
326 			/*
327 			 * Be more specific, e.g. net-pf-2-proto-132-type-1
328 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP-type-SOCK_STREAM)
329 			 */
330 			if (++try_loading_module == 1)
331 				request_module("net-pf-%d-proto-%d-type-%d",
332 					       PF_INET, protocol, sock->type);
333 			/*
334 			 * Fall back to generic, e.g. net-pf-2-proto-132
335 			 * (net-pf-PF_INET-proto-IPPROTO_SCTP)
336 			 */
337 			else
338 				request_module("net-pf-%d-proto-%d",
339 					       PF_INET, protocol);
340 			goto lookup_protocol;
341 		} else
342 			goto out_rcu_unlock;
343 	}
344 
345 	err = -EPERM;
346 	if (answer->capability > 0 && !capable(answer->capability))
347 		goto out_rcu_unlock;
348 
349 	err = -EAFNOSUPPORT;
350 	if (!inet_netns_ok(net, protocol))
351 		goto out_rcu_unlock;
352 
353 	sock->ops = answer->ops;
354 	answer_prot = answer->prot;
355 	answer_no_check = answer->no_check;
356 	answer_flags = answer->flags;
357 	rcu_read_unlock();
358 
359 	WARN_ON(answer_prot->slab == NULL);
360 
361 	err = -ENOBUFS;
362 	sk = sk_alloc(net, PF_INET, GFP_KERNEL, answer_prot);
363 	if (sk == NULL)
364 		goto out;
365 
366 	err = 0;
367 	sk->sk_no_check = answer_no_check;
368 	if (INET_PROTOSW_REUSE & answer_flags)
369 		sk->sk_reuse = 1;
370 
371 	inet = inet_sk(sk);
372 	inet->is_icsk = (INET_PROTOSW_ICSK & answer_flags) != 0;
373 
374 	if (SOCK_RAW == sock->type) {
375 		inet->num = protocol;
376 		if (IPPROTO_RAW == protocol)
377 			inet->hdrincl = 1;
378 	}
379 
380 	if (ipv4_config.no_pmtu_disc)
381 		inet->pmtudisc = IP_PMTUDISC_DONT;
382 	else
383 		inet->pmtudisc = IP_PMTUDISC_WANT;
384 
385 	inet->id = 0;
386 
387 	sock_init_data(sock, sk);
388 
389 	sk->sk_destruct	   = inet_sock_destruct;
390 	sk->sk_family	   = PF_INET;
391 	sk->sk_protocol	   = protocol;
392 	sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
393 
394 	inet->uc_ttl	= -1;
395 	inet->mc_loop	= 1;
396 	inet->mc_ttl	= 1;
397 	inet->mc_index	= 0;
398 	inet->mc_list	= NULL;
399 
400 	sk_refcnt_debug_inc(sk);
401 
402 	if (inet->num) {
403 		/* It assumes that any protocol which allows
404 		 * the user to assign a number at socket
405 		 * creation time automatically
406 		 * shares.
407 		 */
408 		inet->sport = htons(inet->num);
409 		/* Add to protocol hash chains. */
410 		sk->sk_prot->hash(sk);
411 	}
412 
413 	if (sk->sk_prot->init) {
414 		err = sk->sk_prot->init(sk);
415 		if (err)
416 			sk_common_release(sk);
417 	}
418 out:
419 	return err;
420 out_rcu_unlock:
421 	rcu_read_unlock();
422 	goto out;
423 }
424 
425 
426 /*
427  *	The peer socket should always be NULL (or else). When we call this
428  *	function we are destroying the object and from then on nobody
429  *	should refer to it.
430  */
inet_release(struct socket * sock)431 int inet_release(struct socket *sock)
432 {
433 	struct sock *sk = sock->sk;
434 
435 	if (sk) {
436 		long timeout;
437 
438 		/* Applications forget to leave groups before exiting */
439 		ip_mc_drop_socket(sk);
440 
441 		/* If linger is set, we don't return until the close
442 		 * is complete.  Otherwise we return immediately. The
443 		 * actually closing is done the same either way.
444 		 *
445 		 * If the close is due to the process exiting, we never
446 		 * linger..
447 		 */
448 		timeout = 0;
449 		if (sock_flag(sk, SOCK_LINGER) &&
450 		    !(current->flags & PF_EXITING))
451 			timeout = sk->sk_lingertime;
452 		sock->sk = NULL;
453 		sk->sk_prot->close(sk, timeout);
454 	}
455 	return 0;
456 }
457 
458 /* It is off by default, see below. */
459 int sysctl_ip_nonlocal_bind __read_mostly;
460 
inet_bind(struct socket * sock,struct sockaddr * uaddr,int addr_len)461 int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
462 {
463 	struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
464 	struct sock *sk = sock->sk;
465 	struct inet_sock *inet = inet_sk(sk);
466 	unsigned short snum;
467 	int chk_addr_ret;
468 	int err;
469 
470 	/* If the socket has its own bind function then use it. (RAW) */
471 	if (sk->sk_prot->bind) {
472 		err = sk->sk_prot->bind(sk, uaddr, addr_len);
473 		goto out;
474 	}
475 	err = -EINVAL;
476 	if (addr_len < sizeof(struct sockaddr_in))
477 		goto out;
478 
479 	chk_addr_ret = inet_addr_type(sock_net(sk), addr->sin_addr.s_addr);
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 (!sysctl_ip_nonlocal_bind &&
490 	    !(inet->freebind || inet->transparent) &&
491 	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
492 	    chk_addr_ret != RTN_LOCAL &&
493 	    chk_addr_ret != RTN_MULTICAST &&
494 	    chk_addr_ret != RTN_BROADCAST)
495 		goto out;
496 
497 	snum = ntohs(addr->sin_port);
498 	err = -EACCES;
499 	if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
500 		goto out;
501 
502 	/*      We keep a pair of addresses. rcv_saddr is the one
503 	 *      used by hash lookups, and saddr is used for transmit.
504 	 *
505 	 *      In the BSD API these are the same except where it
506 	 *      would be illegal to use them (multicast/broadcast) in
507 	 *      which case the sending device address is used.
508 	 */
509 	lock_sock(sk);
510 
511 	/* Check these errors (active socket, double bind). */
512 	err = -EINVAL;
513 	if (sk->sk_state != TCP_CLOSE || inet->num)
514 		goto out_release_sock;
515 
516 	inet->rcv_saddr = inet->saddr = addr->sin_addr.s_addr;
517 	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)
518 		inet->saddr = 0;  /* Use device */
519 
520 	/* Make sure we are allowed to bind here. */
521 	if (sk->sk_prot->get_port(sk, snum)) {
522 		inet->saddr = inet->rcv_saddr = 0;
523 		err = -EADDRINUSE;
524 		goto out_release_sock;
525 	}
526 
527 	if (inet->rcv_saddr)
528 		sk->sk_userlocks |= SOCK_BINDADDR_LOCK;
529 	if (snum)
530 		sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
531 	inet->sport = htons(inet->num);
532 	inet->daddr = 0;
533 	inet->dport = 0;
534 	sk_dst_reset(sk);
535 	err = 0;
536 out_release_sock:
537 	release_sock(sk);
538 out:
539 	return err;
540 }
541 
inet_dgram_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)542 int inet_dgram_connect(struct socket *sock, struct sockaddr * uaddr,
543 		       int addr_len, int flags)
544 {
545 	struct sock *sk = sock->sk;
546 
547 	if (uaddr->sa_family == AF_UNSPEC)
548 		return sk->sk_prot->disconnect(sk, flags);
549 
550 	if (!inet_sk(sk)->num && inet_autobind(sk))
551 		return -EAGAIN;
552 	return sk->sk_prot->connect(sk, (struct sockaddr *)uaddr, addr_len);
553 }
554 
inet_wait_for_connect(struct sock * sk,long timeo)555 static long inet_wait_for_connect(struct sock *sk, long timeo)
556 {
557 	DEFINE_WAIT(wait);
558 
559 	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
560 
561 	/* Basic assumption: if someone sets sk->sk_err, he _must_
562 	 * change state of the socket from TCP_SYN_*.
563 	 * Connect() does not allow to get error notifications
564 	 * without closing the socket.
565 	 */
566 	while ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
567 		release_sock(sk);
568 		timeo = schedule_timeout(timeo);
569 		lock_sock(sk);
570 		if (signal_pending(current) || !timeo)
571 			break;
572 		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
573 	}
574 	finish_wait(sk->sk_sleep, &wait);
575 	return timeo;
576 }
577 
578 /*
579  *	Connect to a remote host. There is regrettably still a little
580  *	TCP 'magic' in here.
581  */
inet_stream_connect(struct socket * sock,struct sockaddr * uaddr,int addr_len,int flags)582 int inet_stream_connect(struct socket *sock, struct sockaddr *uaddr,
583 			int addr_len, int flags)
584 {
585 	struct sock *sk = sock->sk;
586 	int err;
587 	long timeo;
588 
589 	lock_sock(sk);
590 
591 	if (uaddr->sa_family == AF_UNSPEC) {
592 		err = sk->sk_prot->disconnect(sk, flags);
593 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
594 		goto out;
595 	}
596 
597 	switch (sock->state) {
598 	default:
599 		err = -EINVAL;
600 		goto out;
601 	case SS_CONNECTED:
602 		err = -EISCONN;
603 		goto out;
604 	case SS_CONNECTING:
605 		err = -EALREADY;
606 		/* Fall out of switch with err, set for this state */
607 		break;
608 	case SS_UNCONNECTED:
609 		err = -EISCONN;
610 		if (sk->sk_state != TCP_CLOSE)
611 			goto out;
612 
613 		err = sk->sk_prot->connect(sk, uaddr, addr_len);
614 		if (err < 0)
615 			goto out;
616 
617 		sock->state = SS_CONNECTING;
618 
619 		/* Just entered SS_CONNECTING state; the only
620 		 * difference is that return value in non-blocking
621 		 * case is EINPROGRESS, rather than EALREADY.
622 		 */
623 		err = -EINPROGRESS;
624 		break;
625 	}
626 
627 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
628 
629 	if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
630 		/* Error code is set above */
631 		if (!timeo || !inet_wait_for_connect(sk, timeo))
632 			goto out;
633 
634 		err = sock_intr_errno(timeo);
635 		if (signal_pending(current))
636 			goto out;
637 	}
638 
639 	/* Connection was closed by RST, timeout, ICMP error
640 	 * or another process disconnected us.
641 	 */
642 	if (sk->sk_state == TCP_CLOSE)
643 		goto sock_error;
644 
645 	/* sk->sk_err may be not zero now, if RECVERR was ordered by user
646 	 * and error was received after socket entered established state.
647 	 * Hence, it is handled normally after connect() return successfully.
648 	 */
649 
650 	sock->state = SS_CONNECTED;
651 	err = 0;
652 out:
653 	release_sock(sk);
654 	return err;
655 
656 sock_error:
657 	err = sock_error(sk) ? : -ECONNABORTED;
658 	sock->state = SS_UNCONNECTED;
659 	if (sk->sk_prot->disconnect(sk, flags))
660 		sock->state = SS_DISCONNECTING;
661 	goto out;
662 }
663 
664 /*
665  *	Accept a pending connection. The TCP layer now gives BSD semantics.
666  */
667 
inet_accept(struct socket * sock,struct socket * newsock,int flags)668 int inet_accept(struct socket *sock, struct socket *newsock, int flags)
669 {
670 	struct sock *sk1 = sock->sk;
671 	int err = -EINVAL;
672 	struct sock *sk2 = sk1->sk_prot->accept(sk1, flags, &err);
673 
674 	if (!sk2)
675 		goto do_err;
676 
677 	lock_sock(sk2);
678 
679 	WARN_ON(!((1 << sk2->sk_state) &
680 		  (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_CLOSE)));
681 
682 	sock_graft(sk2, newsock);
683 
684 	newsock->state = SS_CONNECTED;
685 	err = 0;
686 	release_sock(sk2);
687 do_err:
688 	return err;
689 }
690 
691 
692 /*
693  *	This does both peername and sockname.
694  */
inet_getname(struct socket * sock,struct sockaddr * uaddr,int * uaddr_len,int peer)695 int inet_getname(struct socket *sock, struct sockaddr *uaddr,
696 			int *uaddr_len, int peer)
697 {
698 	struct sock *sk		= sock->sk;
699 	struct inet_sock *inet	= inet_sk(sk);
700 	struct sockaddr_in *sin	= (struct sockaddr_in *)uaddr;
701 
702 	sin->sin_family = AF_INET;
703 	if (peer) {
704 		if (!inet->dport ||
705 		    (((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_SYN_SENT)) &&
706 		     peer == 1))
707 			return -ENOTCONN;
708 		sin->sin_port = inet->dport;
709 		sin->sin_addr.s_addr = inet->daddr;
710 	} else {
711 		__be32 addr = inet->rcv_saddr;
712 		if (!addr)
713 			addr = inet->saddr;
714 		sin->sin_port = inet->sport;
715 		sin->sin_addr.s_addr = addr;
716 	}
717 	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
718 	*uaddr_len = sizeof(*sin);
719 	return 0;
720 }
721 
inet_sendmsg(struct kiocb * iocb,struct socket * sock,struct msghdr * msg,size_t size)722 int inet_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
723 		 size_t size)
724 {
725 	struct sock *sk = sock->sk;
726 
727 	/* We may need to bind the socket. */
728 	if (!inet_sk(sk)->num && inet_autobind(sk))
729 		return -EAGAIN;
730 
731 	return sk->sk_prot->sendmsg(iocb, sk, msg, size);
732 }
733 
734 
inet_sendpage(struct socket * sock,struct page * page,int offset,size_t size,int flags)735 static ssize_t inet_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
736 {
737 	struct sock *sk = sock->sk;
738 
739 	/* We may need to bind the socket. */
740 	if (!inet_sk(sk)->num && inet_autobind(sk))
741 		return -EAGAIN;
742 
743 	if (sk->sk_prot->sendpage)
744 		return sk->sk_prot->sendpage(sk, page, offset, size, flags);
745 	return sock_no_sendpage(sock, page, offset, size, flags);
746 }
747 
748 
inet_shutdown(struct socket * sock,int how)749 int inet_shutdown(struct socket *sock, int how)
750 {
751 	struct sock *sk = sock->sk;
752 	int err = 0;
753 
754 	/* This should really check to make sure
755 	 * the socket is a TCP socket. (WHY AC...)
756 	 */
757 	how++; /* maps 0->1 has the advantage of making bit 1 rcvs and
758 		       1->2 bit 2 snds.
759 		       2->3 */
760 	if ((how & ~SHUTDOWN_MASK) || !how)	/* MAXINT->0 */
761 		return -EINVAL;
762 
763 	lock_sock(sk);
764 	if (sock->state == SS_CONNECTING) {
765 		if ((1 << sk->sk_state) &
766 		    (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))
767 			sock->state = SS_DISCONNECTING;
768 		else
769 			sock->state = SS_CONNECTED;
770 	}
771 
772 	switch (sk->sk_state) {
773 	case TCP_CLOSE:
774 		err = -ENOTCONN;
775 		/* Hack to wake up other listeners, who can poll for
776 		   POLLHUP, even on eg. unconnected UDP sockets -- RR */
777 	default:
778 		sk->sk_shutdown |= how;
779 		if (sk->sk_prot->shutdown)
780 			sk->sk_prot->shutdown(sk, how);
781 		break;
782 
783 	/* Remaining two branches are temporary solution for missing
784 	 * close() in multithreaded environment. It is _not_ a good idea,
785 	 * but we have no choice until close() is repaired at VFS level.
786 	 */
787 	case TCP_LISTEN:
788 		if (!(how & RCV_SHUTDOWN))
789 			break;
790 		/* Fall through */
791 	case TCP_SYN_SENT:
792 		err = sk->sk_prot->disconnect(sk, O_NONBLOCK);
793 		sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED;
794 		break;
795 	}
796 
797 	/* Wake up anyone sleeping in poll. */
798 	sk->sk_state_change(sk);
799 	release_sock(sk);
800 	return err;
801 }
802 
803 /*
804  *	ioctl() calls you can issue on an INET socket. Most of these are
805  *	device configuration and stuff and very rarely used. Some ioctls
806  *	pass on to the socket itself.
807  *
808  *	NOTE: I like the idea of a module for the config stuff. ie ifconfig
809  *	loads the devconfigure module does its configuring and unloads it.
810  *	There's a good 20K of config code hanging around the kernel.
811  */
812 
inet_ioctl(struct socket * sock,unsigned int cmd,unsigned long arg)813 int inet_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
814 {
815 	struct sock *sk = sock->sk;
816 	int err = 0;
817 	struct net *net = sock_net(sk);
818 
819 	switch (cmd) {
820 		case SIOCGSTAMP:
821 			err = sock_get_timestamp(sk, (struct timeval __user *)arg);
822 			break;
823 		case SIOCGSTAMPNS:
824 			err = sock_get_timestampns(sk, (struct timespec __user *)arg);
825 			break;
826 		case SIOCADDRT:
827 		case SIOCDELRT:
828 		case SIOCRTMSG:
829 			err = ip_rt_ioctl(net, cmd, (void __user *)arg);
830 			break;
831 		case SIOCDARP:
832 		case SIOCGARP:
833 		case SIOCSARP:
834 			err = arp_ioctl(net, cmd, (void __user *)arg);
835 			break;
836 		case SIOCGIFADDR:
837 		case SIOCSIFADDR:
838 		case SIOCGIFBRDADDR:
839 		case SIOCSIFBRDADDR:
840 		case SIOCGIFNETMASK:
841 		case SIOCSIFNETMASK:
842 		case SIOCGIFDSTADDR:
843 		case SIOCSIFDSTADDR:
844 		case SIOCSIFPFLAGS:
845 		case SIOCGIFPFLAGS:
846 		case SIOCSIFFLAGS:
847 		case SIOCKILLADDR:
848 			err = devinet_ioctl(net, cmd, (void __user *)arg);
849 			break;
850 		default:
851 			if (sk->sk_prot->ioctl)
852 				err = sk->sk_prot->ioctl(sk, cmd, arg);
853 			else
854 				err = -ENOIOCTLCMD;
855 			break;
856 	}
857 	return err;
858 }
859 
860 const struct proto_ops inet_stream_ops = {
861 	.family		   = PF_INET,
862 	.owner		   = THIS_MODULE,
863 	.release	   = inet_release,
864 	.bind		   = inet_bind,
865 	.connect	   = inet_stream_connect,
866 	.socketpair	   = sock_no_socketpair,
867 	.accept		   = inet_accept,
868 	.getname	   = inet_getname,
869 	.poll		   = tcp_poll,
870 	.ioctl		   = inet_ioctl,
871 	.listen		   = inet_listen,
872 	.shutdown	   = inet_shutdown,
873 	.setsockopt	   = sock_common_setsockopt,
874 	.getsockopt	   = sock_common_getsockopt,
875 	.sendmsg	   = tcp_sendmsg,
876 	.recvmsg	   = sock_common_recvmsg,
877 	.mmap		   = sock_no_mmap,
878 	.sendpage	   = tcp_sendpage,
879 	.splice_read	   = tcp_splice_read,
880 #ifdef CONFIG_COMPAT
881 	.compat_setsockopt = compat_sock_common_setsockopt,
882 	.compat_getsockopt = compat_sock_common_getsockopt,
883 #endif
884 };
885 
886 const struct proto_ops inet_dgram_ops = {
887 	.family		   = PF_INET,
888 	.owner		   = THIS_MODULE,
889 	.release	   = inet_release,
890 	.bind		   = inet_bind,
891 	.connect	   = inet_dgram_connect,
892 	.socketpair	   = sock_no_socketpair,
893 	.accept		   = sock_no_accept,
894 	.getname	   = inet_getname,
895 	.poll		   = udp_poll,
896 	.ioctl		   = inet_ioctl,
897 	.listen		   = sock_no_listen,
898 	.shutdown	   = inet_shutdown,
899 	.setsockopt	   = sock_common_setsockopt,
900 	.getsockopt	   = sock_common_getsockopt,
901 	.sendmsg	   = inet_sendmsg,
902 	.recvmsg	   = sock_common_recvmsg,
903 	.mmap		   = sock_no_mmap,
904 	.sendpage	   = inet_sendpage,
905 #ifdef CONFIG_COMPAT
906 	.compat_setsockopt = compat_sock_common_setsockopt,
907 	.compat_getsockopt = compat_sock_common_getsockopt,
908 #endif
909 };
910 
911 /*
912  * For SOCK_RAW sockets; should be the same as inet_dgram_ops but without
913  * udp_poll
914  */
915 static const struct proto_ops inet_sockraw_ops = {
916 	.family		   = PF_INET,
917 	.owner		   = THIS_MODULE,
918 	.release	   = inet_release,
919 	.bind		   = inet_bind,
920 	.connect	   = inet_dgram_connect,
921 	.socketpair	   = sock_no_socketpair,
922 	.accept		   = sock_no_accept,
923 	.getname	   = inet_getname,
924 	.poll		   = datagram_poll,
925 	.ioctl		   = inet_ioctl,
926 	.listen		   = sock_no_listen,
927 	.shutdown	   = inet_shutdown,
928 	.setsockopt	   = sock_common_setsockopt,
929 	.getsockopt	   = sock_common_getsockopt,
930 	.sendmsg	   = inet_sendmsg,
931 	.recvmsg	   = sock_common_recvmsg,
932 	.mmap		   = sock_no_mmap,
933 	.sendpage	   = inet_sendpage,
934 #ifdef CONFIG_COMPAT
935 	.compat_setsockopt = compat_sock_common_setsockopt,
936 	.compat_getsockopt = compat_sock_common_getsockopt,
937 #endif
938 };
939 
940 static struct net_proto_family inet_family_ops = {
941 	.family = PF_INET,
942 	.create = inet_create,
943 	.owner	= THIS_MODULE,
944 };
945 
946 /* Upon startup we insert all the elements in inetsw_array[] into
947  * the linked list inetsw.
948  */
949 static struct inet_protosw inetsw_array[] =
950 {
951 	{
952 		.type =       SOCK_STREAM,
953 		.protocol =   IPPROTO_TCP,
954 		.prot =       &tcp_prot,
955 		.ops =        &inet_stream_ops,
956 		.capability = -1,
957 		.no_check =   0,
958 		.flags =      INET_PROTOSW_PERMANENT |
959 			      INET_PROTOSW_ICSK,
960 	},
961 
962 	{
963 		.type =       SOCK_DGRAM,
964 		.protocol =   IPPROTO_UDP,
965 		.prot =       &udp_prot,
966 		.ops =        &inet_dgram_ops,
967 		.capability = -1,
968 		.no_check =   UDP_CSUM_DEFAULT,
969 		.flags =      INET_PROTOSW_PERMANENT,
970        },
971 
972 
973        {
974 	       .type =       SOCK_RAW,
975 	       .protocol =   IPPROTO_IP,	/* wild card */
976 	       .prot =       &raw_prot,
977 	       .ops =        &inet_sockraw_ops,
978 	       .capability = CAP_NET_RAW,
979 	       .no_check =   UDP_CSUM_DEFAULT,
980 	       .flags =      INET_PROTOSW_REUSE,
981        }
982 };
983 
984 #define INETSW_ARRAY_LEN ARRAY_SIZE(inetsw_array)
985 
inet_register_protosw(struct inet_protosw * p)986 void inet_register_protosw(struct inet_protosw *p)
987 {
988 	struct list_head *lh;
989 	struct inet_protosw *answer;
990 	int protocol = p->protocol;
991 	struct list_head *last_perm;
992 
993 	spin_lock_bh(&inetsw_lock);
994 
995 	if (p->type >= SOCK_MAX)
996 		goto out_illegal;
997 
998 	/* If we are trying to override a permanent protocol, bail. */
999 	answer = NULL;
1000 	last_perm = &inetsw[p->type];
1001 	list_for_each(lh, &inetsw[p->type]) {
1002 		answer = list_entry(lh, struct inet_protosw, list);
1003 
1004 		/* Check only the non-wild match. */
1005 		if (INET_PROTOSW_PERMANENT & answer->flags) {
1006 			if (protocol == answer->protocol)
1007 				break;
1008 			last_perm = lh;
1009 		}
1010 
1011 		answer = NULL;
1012 	}
1013 	if (answer)
1014 		goto out_permanent;
1015 
1016 	/* Add the new entry after the last permanent entry if any, so that
1017 	 * the new entry does not override a permanent entry when matched with
1018 	 * a wild-card protocol. But it is allowed to override any existing
1019 	 * non-permanent entry.  This means that when we remove this entry, the
1020 	 * system automatically returns to the old behavior.
1021 	 */
1022 	list_add_rcu(&p->list, last_perm);
1023 out:
1024 	spin_unlock_bh(&inetsw_lock);
1025 
1026 	synchronize_net();
1027 
1028 	return;
1029 
1030 out_permanent:
1031 	printk(KERN_ERR "Attempt to override permanent protocol %d.\n",
1032 	       protocol);
1033 	goto out;
1034 
1035 out_illegal:
1036 	printk(KERN_ERR
1037 	       "Ignoring attempt to register invalid socket type %d.\n",
1038 	       p->type);
1039 	goto out;
1040 }
1041 
inet_unregister_protosw(struct inet_protosw * p)1042 void inet_unregister_protosw(struct inet_protosw *p)
1043 {
1044 	if (INET_PROTOSW_PERMANENT & p->flags) {
1045 		printk(KERN_ERR
1046 		       "Attempt to unregister permanent protocol %d.\n",
1047 		       p->protocol);
1048 	} else {
1049 		spin_lock_bh(&inetsw_lock);
1050 		list_del_rcu(&p->list);
1051 		spin_unlock_bh(&inetsw_lock);
1052 
1053 		synchronize_net();
1054 	}
1055 }
1056 
1057 /*
1058  *      Shall we try to damage output packets if routing dev changes?
1059  */
1060 
1061 int sysctl_ip_dynaddr __read_mostly;
1062 
inet_sk_reselect_saddr(struct sock * sk)1063 static int inet_sk_reselect_saddr(struct sock *sk)
1064 {
1065 	struct inet_sock *inet = inet_sk(sk);
1066 	int err;
1067 	struct rtable *rt;
1068 	__be32 old_saddr = inet->saddr;
1069 	__be32 new_saddr;
1070 	__be32 daddr = inet->daddr;
1071 
1072 	if (inet->opt && inet->opt->srr)
1073 		daddr = inet->opt->faddr;
1074 
1075 	/* Query new route. */
1076 	err = ip_route_connect(&rt, daddr, 0,
1077 			       RT_CONN_FLAGS(sk),
1078 			       sk->sk_bound_dev_if,
1079 			       sk->sk_protocol,
1080 			       inet->sport, inet->dport, sk, 0);
1081 	if (err)
1082 		return err;
1083 
1084 	sk_setup_caps(sk, &rt->u.dst);
1085 
1086 	new_saddr = rt->rt_src;
1087 
1088 	if (new_saddr == old_saddr)
1089 		return 0;
1090 
1091 	if (sysctl_ip_dynaddr > 1) {
1092 		printk(KERN_INFO "%s(): shifting inet->saddr from %pI4 to %pI4\n",
1093 		       __func__, &old_saddr, &new_saddr);
1094 	}
1095 
1096 	inet->saddr = inet->rcv_saddr = new_saddr;
1097 
1098 	/*
1099 	 * XXX The only one ugly spot where we need to
1100 	 * XXX really change the sockets identity after
1101 	 * XXX it has entered the hashes. -DaveM
1102 	 *
1103 	 * Besides that, it does not check for connection
1104 	 * uniqueness. Wait for troubles.
1105 	 */
1106 	__sk_prot_rehash(sk);
1107 	return 0;
1108 }
1109 
inet_sk_rebuild_header(struct sock * sk)1110 int inet_sk_rebuild_header(struct sock *sk)
1111 {
1112 	struct inet_sock *inet = inet_sk(sk);
1113 	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
1114 	__be32 daddr;
1115 	int err;
1116 
1117 	/* Route is OK, nothing to do. */
1118 	if (rt)
1119 		return 0;
1120 
1121 	/* Reroute. */
1122 	daddr = inet->daddr;
1123 	if (inet->opt && inet->opt->srr)
1124 		daddr = inet->opt->faddr;
1125 {
1126 	struct flowi fl = {
1127 		.oif = sk->sk_bound_dev_if,
1128 		.nl_u = {
1129 			.ip4_u = {
1130 				.daddr	= daddr,
1131 				.saddr	= inet->saddr,
1132 				.tos	= RT_CONN_FLAGS(sk),
1133 			},
1134 		},
1135 		.proto = sk->sk_protocol,
1136 		.flags = inet_sk_flowi_flags(sk),
1137 		.uli_u = {
1138 			.ports = {
1139 				.sport = inet->sport,
1140 				.dport = inet->dport,
1141 			},
1142 		},
1143 	};
1144 
1145 	security_sk_classify_flow(sk, &fl);
1146 	err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0);
1147 }
1148 	if (!err)
1149 		sk_setup_caps(sk, &rt->u.dst);
1150 	else {
1151 		/* Routing failed... */
1152 		sk->sk_route_caps = 0;
1153 		/*
1154 		 * Other protocols have to map its equivalent state to TCP_SYN_SENT.
1155 		 * DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
1156 		 */
1157 		if (!sysctl_ip_dynaddr ||
1158 		    sk->sk_state != TCP_SYN_SENT ||
1159 		    (sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
1160 		    (err = inet_sk_reselect_saddr(sk)) != 0)
1161 			sk->sk_err_soft = -err;
1162 	}
1163 
1164 	return err;
1165 }
1166 
1167 EXPORT_SYMBOL(inet_sk_rebuild_header);
1168 
inet_gso_send_check(struct sk_buff * skb)1169 static int inet_gso_send_check(struct sk_buff *skb)
1170 {
1171 	struct iphdr *iph;
1172 	struct net_protocol *ops;
1173 	int proto;
1174 	int ihl;
1175 	int err = -EINVAL;
1176 
1177 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1178 		goto out;
1179 
1180 	iph = ip_hdr(skb);
1181 	ihl = iph->ihl * 4;
1182 	if (ihl < sizeof(*iph))
1183 		goto out;
1184 
1185 	if (unlikely(!pskb_may_pull(skb, ihl)))
1186 		goto out;
1187 
1188 	__skb_pull(skb, ihl);
1189 	skb_reset_transport_header(skb);
1190 	iph = ip_hdr(skb);
1191 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1192 	err = -EPROTONOSUPPORT;
1193 
1194 	rcu_read_lock();
1195 	ops = rcu_dereference(inet_protos[proto]);
1196 	if (likely(ops && ops->gso_send_check))
1197 		err = ops->gso_send_check(skb);
1198 	rcu_read_unlock();
1199 
1200 out:
1201 	return err;
1202 }
1203 
inet_gso_segment(struct sk_buff * skb,int features)1204 static struct sk_buff *inet_gso_segment(struct sk_buff *skb, int features)
1205 {
1206 	struct sk_buff *segs = ERR_PTR(-EINVAL);
1207 	struct iphdr *iph;
1208 	struct net_protocol *ops;
1209 	int proto;
1210 	int ihl;
1211 	int id;
1212 
1213 	if (!(features & NETIF_F_V4_CSUM))
1214 		features &= ~NETIF_F_SG;
1215 
1216 	if (unlikely(skb_shinfo(skb)->gso_type &
1217 		     ~(SKB_GSO_TCPV4 |
1218 		       SKB_GSO_UDP |
1219 		       SKB_GSO_DODGY |
1220 		       SKB_GSO_TCP_ECN |
1221 		       0)))
1222 		goto out;
1223 
1224 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1225 		goto out;
1226 
1227 	iph = ip_hdr(skb);
1228 	ihl = iph->ihl * 4;
1229 	if (ihl < sizeof(*iph))
1230 		goto out;
1231 
1232 	if (unlikely(!pskb_may_pull(skb, ihl)))
1233 		goto out;
1234 
1235 	__skb_pull(skb, ihl);
1236 	skb_reset_transport_header(skb);
1237 	iph = ip_hdr(skb);
1238 	id = ntohs(iph->id);
1239 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1240 	segs = ERR_PTR(-EPROTONOSUPPORT);
1241 
1242 	rcu_read_lock();
1243 	ops = rcu_dereference(inet_protos[proto]);
1244 	if (likely(ops && ops->gso_segment))
1245 		segs = ops->gso_segment(skb, features);
1246 	rcu_read_unlock();
1247 
1248 	if (!segs || IS_ERR(segs))
1249 		goto out;
1250 
1251 	skb = segs;
1252 	do {
1253 		iph = ip_hdr(skb);
1254 		iph->id = htons(id++);
1255 		iph->tot_len = htons(skb->len - skb->mac_len);
1256 		iph->check = 0;
1257 		iph->check = ip_fast_csum(skb_network_header(skb), iph->ihl);
1258 	} while ((skb = skb->next));
1259 
1260 out:
1261 	return segs;
1262 }
1263 
inet_gro_receive(struct sk_buff ** head,struct sk_buff * skb)1264 static struct sk_buff **inet_gro_receive(struct sk_buff **head,
1265 					 struct sk_buff *skb)
1266 {
1267 	struct net_protocol *ops;
1268 	struct sk_buff **pp = NULL;
1269 	struct sk_buff *p;
1270 	struct iphdr *iph;
1271 	int flush = 1;
1272 	int proto;
1273 	int id;
1274 
1275 	if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
1276 		goto out;
1277 
1278 	iph = ip_hdr(skb);
1279 	proto = iph->protocol & (MAX_INET_PROTOS - 1);
1280 
1281 	rcu_read_lock();
1282 	ops = rcu_dereference(inet_protos[proto]);
1283 	if (!ops || !ops->gro_receive)
1284 		goto out_unlock;
1285 
1286 	if (iph->version != 4 || iph->ihl != 5)
1287 		goto out_unlock;
1288 
1289 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
1290 		goto out_unlock;
1291 
1292 	flush = ntohs(iph->tot_len) != skb->len ||
1293 		iph->frag_off != htons(IP_DF);
1294 	id = ntohs(iph->id);
1295 
1296 	for (p = *head; p; p = p->next) {
1297 		struct iphdr *iph2;
1298 
1299 		if (!NAPI_GRO_CB(p)->same_flow)
1300 			continue;
1301 
1302 		iph2 = ip_hdr(p);
1303 
1304 		if (iph->protocol != iph2->protocol ||
1305 		    iph->tos != iph2->tos ||
1306 		    memcmp(&iph->saddr, &iph2->saddr, 8)) {
1307 			NAPI_GRO_CB(p)->same_flow = 0;
1308 			continue;
1309 		}
1310 
1311 		/* All fields must match except length and checksum. */
1312 		NAPI_GRO_CB(p)->flush |=
1313 			memcmp(&iph->frag_off, &iph2->frag_off, 4) ||
1314 			(u16)(ntohs(iph2->id) + NAPI_GRO_CB(p)->count) != id;
1315 
1316 		NAPI_GRO_CB(p)->flush |= flush;
1317 	}
1318 
1319 	NAPI_GRO_CB(skb)->flush |= flush;
1320 	__skb_pull(skb, sizeof(*iph));
1321 	skb_reset_transport_header(skb);
1322 
1323 	pp = ops->gro_receive(head, skb);
1324 
1325 out_unlock:
1326 	rcu_read_unlock();
1327 
1328 out:
1329 	NAPI_GRO_CB(skb)->flush |= flush;
1330 
1331 	return pp;
1332 }
1333 
inet_gro_complete(struct sk_buff * skb)1334 static int inet_gro_complete(struct sk_buff *skb)
1335 {
1336 	struct net_protocol *ops;
1337 	struct iphdr *iph = ip_hdr(skb);
1338 	int proto = iph->protocol & (MAX_INET_PROTOS - 1);
1339 	int err = -ENOSYS;
1340 	__be16 newlen = htons(skb->len - skb_network_offset(skb));
1341 
1342 	csum_replace2(&iph->check, iph->tot_len, newlen);
1343 	iph->tot_len = newlen;
1344 
1345 	rcu_read_lock();
1346 	ops = rcu_dereference(inet_protos[proto]);
1347 	if (WARN_ON(!ops || !ops->gro_complete))
1348 		goto out_unlock;
1349 
1350 	err = ops->gro_complete(skb);
1351 
1352 out_unlock:
1353 	rcu_read_unlock();
1354 
1355 	return err;
1356 }
1357 
inet_ctl_sock_create(struct sock ** sk,unsigned short family,unsigned short type,unsigned char protocol,struct net * net)1358 int inet_ctl_sock_create(struct sock **sk, unsigned short family,
1359 			 unsigned short type, unsigned char protocol,
1360 			 struct net *net)
1361 {
1362 	struct socket *sock;
1363 	int rc = sock_create_kern(family, type, protocol, &sock);
1364 
1365 	if (rc == 0) {
1366 		*sk = sock->sk;
1367 		(*sk)->sk_allocation = GFP_ATOMIC;
1368 		/*
1369 		 * Unhash it so that IP input processing does not even see it,
1370 		 * we do not wish this socket to see incoming packets.
1371 		 */
1372 		(*sk)->sk_prot->unhash(*sk);
1373 
1374 		sk_change_net(*sk, net);
1375 	}
1376 	return rc;
1377 }
1378 
1379 EXPORT_SYMBOL_GPL(inet_ctl_sock_create);
1380 
snmp_fold_field(void * mib[],int offt)1381 unsigned long snmp_fold_field(void *mib[], int offt)
1382 {
1383 	unsigned long res = 0;
1384 	int i;
1385 
1386 	for_each_possible_cpu(i) {
1387 		res += *(((unsigned long *) per_cpu_ptr(mib[0], i)) + offt);
1388 		res += *(((unsigned long *) per_cpu_ptr(mib[1], i)) + offt);
1389 	}
1390 	return res;
1391 }
1392 EXPORT_SYMBOL_GPL(snmp_fold_field);
1393 
snmp_mib_init(void * ptr[2],size_t mibsize)1394 int snmp_mib_init(void *ptr[2], size_t mibsize)
1395 {
1396 	BUG_ON(ptr == NULL);
1397 	ptr[0] = __alloc_percpu(mibsize);
1398 	if (!ptr[0])
1399 		goto err0;
1400 	ptr[1] = __alloc_percpu(mibsize);
1401 	if (!ptr[1])
1402 		goto err1;
1403 	return 0;
1404 err1:
1405 	free_percpu(ptr[0]);
1406 	ptr[0] = NULL;
1407 err0:
1408 	return -ENOMEM;
1409 }
1410 EXPORT_SYMBOL_GPL(snmp_mib_init);
1411 
snmp_mib_free(void * ptr[2])1412 void snmp_mib_free(void *ptr[2])
1413 {
1414 	BUG_ON(ptr == NULL);
1415 	free_percpu(ptr[0]);
1416 	free_percpu(ptr[1]);
1417 	ptr[0] = ptr[1] = NULL;
1418 }
1419 EXPORT_SYMBOL_GPL(snmp_mib_free);
1420 
1421 #ifdef CONFIG_IP_MULTICAST
1422 static struct net_protocol igmp_protocol = {
1423 	.handler =	igmp_rcv,
1424 	.netns_ok =	1,
1425 };
1426 #endif
1427 
1428 static struct net_protocol tcp_protocol = {
1429 	.handler =	tcp_v4_rcv,
1430 	.err_handler =	tcp_v4_err,
1431 	.gso_send_check = tcp_v4_gso_send_check,
1432 	.gso_segment =	tcp_tso_segment,
1433 	.gro_receive =	tcp4_gro_receive,
1434 	.gro_complete =	tcp4_gro_complete,
1435 	.no_policy =	1,
1436 	.netns_ok =	1,
1437 };
1438 
1439 static struct net_protocol udp_protocol = {
1440 	.handler =	udp_rcv,
1441 	.err_handler =	udp_err,
1442 	.no_policy =	1,
1443 	.netns_ok =	1,
1444 };
1445 
1446 static struct net_protocol icmp_protocol = {
1447 	.handler =	icmp_rcv,
1448 	.no_policy =	1,
1449 	.netns_ok =	1,
1450 };
1451 
ipv4_mib_init_net(struct net * net)1452 static __net_init int ipv4_mib_init_net(struct net *net)
1453 {
1454 	if (snmp_mib_init((void **)net->mib.tcp_statistics,
1455 			  sizeof(struct tcp_mib)) < 0)
1456 		goto err_tcp_mib;
1457 	if (snmp_mib_init((void **)net->mib.ip_statistics,
1458 			  sizeof(struct ipstats_mib)) < 0)
1459 		goto err_ip_mib;
1460 	if (snmp_mib_init((void **)net->mib.net_statistics,
1461 			  sizeof(struct linux_mib)) < 0)
1462 		goto err_net_mib;
1463 	if (snmp_mib_init((void **)net->mib.udp_statistics,
1464 			  sizeof(struct udp_mib)) < 0)
1465 		goto err_udp_mib;
1466 	if (snmp_mib_init((void **)net->mib.udplite_statistics,
1467 			  sizeof(struct udp_mib)) < 0)
1468 		goto err_udplite_mib;
1469 	if (snmp_mib_init((void **)net->mib.icmp_statistics,
1470 			  sizeof(struct icmp_mib)) < 0)
1471 		goto err_icmp_mib;
1472 	if (snmp_mib_init((void **)net->mib.icmpmsg_statistics,
1473 			  sizeof(struct icmpmsg_mib)) < 0)
1474 		goto err_icmpmsg_mib;
1475 
1476 	tcp_mib_init(net);
1477 	return 0;
1478 
1479 err_icmpmsg_mib:
1480 	snmp_mib_free((void **)net->mib.icmp_statistics);
1481 err_icmp_mib:
1482 	snmp_mib_free((void **)net->mib.udplite_statistics);
1483 err_udplite_mib:
1484 	snmp_mib_free((void **)net->mib.udp_statistics);
1485 err_udp_mib:
1486 	snmp_mib_free((void **)net->mib.net_statistics);
1487 err_net_mib:
1488 	snmp_mib_free((void **)net->mib.ip_statistics);
1489 err_ip_mib:
1490 	snmp_mib_free((void **)net->mib.tcp_statistics);
1491 err_tcp_mib:
1492 	return -ENOMEM;
1493 }
1494 
ipv4_mib_exit_net(struct net * net)1495 static __net_exit void ipv4_mib_exit_net(struct net *net)
1496 {
1497 	snmp_mib_free((void **)net->mib.icmpmsg_statistics);
1498 	snmp_mib_free((void **)net->mib.icmp_statistics);
1499 	snmp_mib_free((void **)net->mib.udplite_statistics);
1500 	snmp_mib_free((void **)net->mib.udp_statistics);
1501 	snmp_mib_free((void **)net->mib.net_statistics);
1502 	snmp_mib_free((void **)net->mib.ip_statistics);
1503 	snmp_mib_free((void **)net->mib.tcp_statistics);
1504 }
1505 
1506 static __net_initdata struct pernet_operations ipv4_mib_ops = {
1507 	.init = ipv4_mib_init_net,
1508 	.exit = ipv4_mib_exit_net,
1509 };
1510 
init_ipv4_mibs(void)1511 static int __init init_ipv4_mibs(void)
1512 {
1513 	return register_pernet_subsys(&ipv4_mib_ops);
1514 }
1515 
1516 static int ipv4_proc_init(void);
1517 
1518 /*
1519  *	IP protocol layer initialiser
1520  */
1521 
1522 static struct packet_type ip_packet_type = {
1523 	.type = __constant_htons(ETH_P_IP),
1524 	.func = ip_rcv,
1525 	.gso_send_check = inet_gso_send_check,
1526 	.gso_segment = inet_gso_segment,
1527 	.gro_receive = inet_gro_receive,
1528 	.gro_complete = inet_gro_complete,
1529 };
1530 
inet_init(void)1531 static int __init inet_init(void)
1532 {
1533 	struct sk_buff *dummy_skb;
1534 	struct inet_protosw *q;
1535 	struct list_head *r;
1536 	int rc = -EINVAL;
1537 
1538 	BUILD_BUG_ON(sizeof(struct inet_skb_parm) > sizeof(dummy_skb->cb));
1539 
1540 	rc = proto_register(&tcp_prot, 1);
1541 	if (rc)
1542 		goto out;
1543 
1544 	rc = proto_register(&udp_prot, 1);
1545 	if (rc)
1546 		goto out_unregister_tcp_proto;
1547 
1548 	rc = proto_register(&raw_prot, 1);
1549 	if (rc)
1550 		goto out_unregister_udp_proto;
1551 
1552 	/*
1553 	 *	Tell SOCKET that we are alive...
1554 	 */
1555 
1556 	(void)sock_register(&inet_family_ops);
1557 
1558 #ifdef CONFIG_SYSCTL
1559 	ip_static_sysctl_init();
1560 #endif
1561 
1562 	/*
1563 	 *	Add all the base protocols.
1564 	 */
1565 
1566 	if (inet_add_protocol(&icmp_protocol, IPPROTO_ICMP) < 0)
1567 		printk(KERN_CRIT "inet_init: Cannot add ICMP protocol\n");
1568 	if (inet_add_protocol(&udp_protocol, IPPROTO_UDP) < 0)
1569 		printk(KERN_CRIT "inet_init: Cannot add UDP protocol\n");
1570 	if (inet_add_protocol(&tcp_protocol, IPPROTO_TCP) < 0)
1571 		printk(KERN_CRIT "inet_init: Cannot add TCP protocol\n");
1572 #ifdef CONFIG_IP_MULTICAST
1573 	if (inet_add_protocol(&igmp_protocol, IPPROTO_IGMP) < 0)
1574 		printk(KERN_CRIT "inet_init: Cannot add IGMP protocol\n");
1575 #endif
1576 
1577 	/* Register the socket-side information for inet_create. */
1578 	for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r)
1579 		INIT_LIST_HEAD(r);
1580 
1581 	for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)
1582 		inet_register_protosw(q);
1583 
1584 	/*
1585 	 *	Set the ARP module up
1586 	 */
1587 
1588 	arp_init();
1589 
1590 	/*
1591 	 *	Set the IP module up
1592 	 */
1593 
1594 	ip_init();
1595 
1596 	tcp_v4_init();
1597 
1598 	/* Setup TCP slab cache for open requests. */
1599 	tcp_init();
1600 
1601 	/* Setup UDP memory threshold */
1602 	udp_init();
1603 
1604 	/* Add UDP-Lite (RFC 3828) */
1605 	udplite4_register();
1606 
1607 	/*
1608 	 *	Set the ICMP layer up
1609 	 */
1610 
1611 	if (icmp_init() < 0)
1612 		panic("Failed to create the ICMP control socket.\n");
1613 
1614 	/*
1615 	 *	Initialise the multicast router
1616 	 */
1617 #if defined(CONFIG_IP_MROUTE)
1618 	if (ip_mr_init())
1619 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mroute\n");
1620 #endif
1621 	/*
1622 	 *	Initialise per-cpu ipv4 mibs
1623 	 */
1624 
1625 	if (init_ipv4_mibs())
1626 		printk(KERN_CRIT "inet_init: Cannot init ipv4 mibs\n");
1627 
1628 	ipv4_proc_init();
1629 
1630 	ipfrag_init();
1631 
1632 	dev_add_pack(&ip_packet_type);
1633 
1634 	rc = 0;
1635 out:
1636 	return rc;
1637 out_unregister_udp_proto:
1638 	proto_unregister(&udp_prot);
1639 out_unregister_tcp_proto:
1640 	proto_unregister(&tcp_prot);
1641 	goto out;
1642 }
1643 
1644 fs_initcall(inet_init);
1645 
1646 /* ------------------------------------------------------------------------ */
1647 
1648 #ifdef CONFIG_PROC_FS
ipv4_proc_init(void)1649 static int __init ipv4_proc_init(void)
1650 {
1651 	int rc = 0;
1652 
1653 	if (raw_proc_init())
1654 		goto out_raw;
1655 	if (tcp4_proc_init())
1656 		goto out_tcp;
1657 	if (udp4_proc_init())
1658 		goto out_udp;
1659 	if (ip_misc_proc_init())
1660 		goto out_misc;
1661 out:
1662 	return rc;
1663 out_misc:
1664 	udp4_proc_exit();
1665 out_udp:
1666 	tcp4_proc_exit();
1667 out_tcp:
1668 	raw_proc_exit();
1669 out_raw:
1670 	rc = -ENOMEM;
1671 	goto out;
1672 }
1673 
1674 #else /* CONFIG_PROC_FS */
ipv4_proc_init(void)1675 static int __init ipv4_proc_init(void)
1676 {
1677 	return 0;
1678 }
1679 #endif /* CONFIG_PROC_FS */
1680 
1681 MODULE_ALIAS_NETPROTO(PF_INET);
1682 
1683 EXPORT_SYMBOL(inet_accept);
1684 EXPORT_SYMBOL(inet_bind);
1685 EXPORT_SYMBOL(inet_dgram_connect);
1686 EXPORT_SYMBOL(inet_dgram_ops);
1687 EXPORT_SYMBOL(inet_getname);
1688 EXPORT_SYMBOL(inet_ioctl);
1689 EXPORT_SYMBOL(inet_listen);
1690 EXPORT_SYMBOL(inet_register_protosw);
1691 EXPORT_SYMBOL(inet_release);
1692 EXPORT_SYMBOL(inet_sendmsg);
1693 EXPORT_SYMBOL(inet_shutdown);
1694 EXPORT_SYMBOL(inet_sock_destruct);
1695 EXPORT_SYMBOL(inet_stream_connect);
1696 EXPORT_SYMBOL(inet_stream_ops);
1697 EXPORT_SYMBOL(inet_unregister_protosw);
1698 EXPORT_SYMBOL(sysctl_ip_nonlocal_bind);
1699