xref: /linux/net/ipv4/ip_sockglue.c (revision 4dc7ccf7e9d9bca1989b840be9e8e84911387cf2)
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  *		The IP to API glue.
7  *
8  * Authors:	see ip.c
9  *
10  * Fixes:
11  *		Many		:	Split from ip.c , see ip.c for history.
12  *		Martin Mares	:	TOS setting fixed.
13  *		Alan Cox	:	Fixed a couple of oopses in Martin's
14  *					TOS tweaks.
15  *		Mike McLagan	:	Routing by source
16  */
17 
18 #include <linux/module.h>
19 #include <linux/types.h>
20 #include <linux/mm.h>
21 #include <linux/skbuff.h>
22 #include <linux/ip.h>
23 #include <linux/icmp.h>
24 #include <linux/inetdevice.h>
25 #include <linux/netdevice.h>
26 #include <linux/slab.h>
27 #include <net/sock.h>
28 #include <net/ip.h>
29 #include <net/icmp.h>
30 #include <net/tcp_states.h>
31 #include <linux/udp.h>
32 #include <linux/igmp.h>
33 #include <linux/netfilter.h>
34 #include <linux/route.h>
35 #include <linux/mroute.h>
36 #include <net/route.h>
37 #include <net/xfrm.h>
38 #include <net/compat.h>
39 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
40 #include <net/transp_v6.h>
41 #endif
42 
43 #include <linux/errqueue.h>
44 #include <asm/uaccess.h>
45 
46 #define IP_CMSG_PKTINFO		1
47 #define IP_CMSG_TTL		2
48 #define IP_CMSG_TOS		4
49 #define IP_CMSG_RECVOPTS	8
50 #define IP_CMSG_RETOPTS		16
51 #define IP_CMSG_PASSSEC		32
52 #define IP_CMSG_ORIGDSTADDR     64
53 
54 /*
55  *	SOL_IP control messages.
56  */
57 
58 static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
59 {
60 	struct in_pktinfo info;
61 	struct rtable *rt = skb_rtable(skb);
62 
63 	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
64 	if (rt) {
65 		info.ipi_ifindex = rt->rt_iif;
66 		info.ipi_spec_dst.s_addr = rt->rt_spec_dst;
67 	} else {
68 		info.ipi_ifindex = 0;
69 		info.ipi_spec_dst.s_addr = 0;
70 	}
71 
72 	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
73 }
74 
75 static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
76 {
77 	int ttl = ip_hdr(skb)->ttl;
78 	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
79 }
80 
81 static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
82 {
83 	put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
84 }
85 
86 static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
87 {
88 	if (IPCB(skb)->opt.optlen == 0)
89 		return;
90 
91 	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
92 		 ip_hdr(skb) + 1);
93 }
94 
95 
96 static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
97 {
98 	unsigned char optbuf[sizeof(struct ip_options) + 40];
99 	struct ip_options * opt = (struct ip_options *)optbuf;
100 
101 	if (IPCB(skb)->opt.optlen == 0)
102 		return;
103 
104 	if (ip_options_echo(opt, skb)) {
105 		msg->msg_flags |= MSG_CTRUNC;
106 		return;
107 	}
108 	ip_options_undo(opt);
109 
110 	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
111 }
112 
113 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
114 {
115 	char *secdata;
116 	u32 seclen, secid;
117 	int err;
118 
119 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
120 	if (err)
121 		return;
122 
123 	err = security_secid_to_secctx(secid, &secdata, &seclen);
124 	if (err)
125 		return;
126 
127 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
128 	security_release_secctx(secdata, seclen);
129 }
130 
131 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
132 {
133 	struct sockaddr_in sin;
134 	struct iphdr *iph = ip_hdr(skb);
135 	__be16 *ports = (__be16 *)skb_transport_header(skb);
136 
137 	if (skb_transport_offset(skb) + 4 > skb->len)
138 		return;
139 
140 	/* All current transport protocols have the port numbers in the
141 	 * first four bytes of the transport header and this function is
142 	 * written with this assumption in mind.
143 	 */
144 
145 	sin.sin_family = AF_INET;
146 	sin.sin_addr.s_addr = iph->daddr;
147 	sin.sin_port = ports[1];
148 	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
149 
150 	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
151 }
152 
153 void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
154 {
155 	struct inet_sock *inet = inet_sk(skb->sk);
156 	unsigned flags = inet->cmsg_flags;
157 
158 	/* Ordered by supposed usage frequency */
159 	if (flags & 1)
160 		ip_cmsg_recv_pktinfo(msg, skb);
161 	if ((flags >>= 1) == 0)
162 		return;
163 
164 	if (flags & 1)
165 		ip_cmsg_recv_ttl(msg, skb);
166 	if ((flags >>= 1) == 0)
167 		return;
168 
169 	if (flags & 1)
170 		ip_cmsg_recv_tos(msg, skb);
171 	if ((flags >>= 1) == 0)
172 		return;
173 
174 	if (flags & 1)
175 		ip_cmsg_recv_opts(msg, skb);
176 	if ((flags >>= 1) == 0)
177 		return;
178 
179 	if (flags & 1)
180 		ip_cmsg_recv_retopts(msg, skb);
181 	if ((flags >>= 1) == 0)
182 		return;
183 
184 	if (flags & 1)
185 		ip_cmsg_recv_security(msg, skb);
186 
187 	if ((flags >>= 1) == 0)
188 		return;
189 	if (flags & 1)
190 		ip_cmsg_recv_dstaddr(msg, skb);
191 
192 }
193 EXPORT_SYMBOL(ip_cmsg_recv);
194 
195 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc)
196 {
197 	int err;
198 	struct cmsghdr *cmsg;
199 
200 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
201 		if (!CMSG_OK(msg, cmsg))
202 			return -EINVAL;
203 		if (cmsg->cmsg_level != SOL_IP)
204 			continue;
205 		switch (cmsg->cmsg_type) {
206 		case IP_RETOPTS:
207 			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
208 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
209 					     err < 40 ? err : 40);
210 			if (err)
211 				return err;
212 			break;
213 		case IP_PKTINFO:
214 		{
215 			struct in_pktinfo *info;
216 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
217 				return -EINVAL;
218 			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
219 			ipc->oif = info->ipi_ifindex;
220 			ipc->addr = info->ipi_spec_dst.s_addr;
221 			break;
222 		}
223 		default:
224 			return -EINVAL;
225 		}
226 	}
227 	return 0;
228 }
229 
230 
231 /* Special input handler for packets caught by router alert option.
232    They are selected only by protocol field, and then processed likely
233    local ones; but only if someone wants them! Otherwise, router
234    not running rsvpd will kill RSVP.
235 
236    It is user level problem, what it will make with them.
237    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
238    but receiver should be enough clever f.e. to forward mtrace requests,
239    sent to multicast group to reach destination designated router.
240  */
241 struct ip_ra_chain *ip_ra_chain;
242 DEFINE_RWLOCK(ip_ra_lock);
243 
244 int ip_ra_control(struct sock *sk, unsigned char on,
245 		  void (*destructor)(struct sock *))
246 {
247 	struct ip_ra_chain *ra, *new_ra, **rap;
248 
249 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
250 		return -EINVAL;
251 
252 	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
253 
254 	write_lock_bh(&ip_ra_lock);
255 	for (rap = &ip_ra_chain; (ra = *rap) != NULL; rap = &ra->next) {
256 		if (ra->sk == sk) {
257 			if (on) {
258 				write_unlock_bh(&ip_ra_lock);
259 				kfree(new_ra);
260 				return -EADDRINUSE;
261 			}
262 			*rap = ra->next;
263 			write_unlock_bh(&ip_ra_lock);
264 
265 			if (ra->destructor)
266 				ra->destructor(sk);
267 			sock_put(sk);
268 			kfree(ra);
269 			return 0;
270 		}
271 	}
272 	if (new_ra == NULL) {
273 		write_unlock_bh(&ip_ra_lock);
274 		return -ENOBUFS;
275 	}
276 	new_ra->sk = sk;
277 	new_ra->destructor = destructor;
278 
279 	new_ra->next = ra;
280 	*rap = new_ra;
281 	sock_hold(sk);
282 	write_unlock_bh(&ip_ra_lock);
283 
284 	return 0;
285 }
286 
287 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
288 		   __be16 port, u32 info, u8 *payload)
289 {
290 	struct inet_sock *inet = inet_sk(sk);
291 	struct sock_exterr_skb *serr;
292 
293 	if (!inet->recverr)
294 		return;
295 
296 	skb = skb_clone(skb, GFP_ATOMIC);
297 	if (!skb)
298 		return;
299 
300 	serr = SKB_EXT_ERR(skb);
301 	serr->ee.ee_errno = err;
302 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
303 	serr->ee.ee_type = icmp_hdr(skb)->type;
304 	serr->ee.ee_code = icmp_hdr(skb)->code;
305 	serr->ee.ee_pad = 0;
306 	serr->ee.ee_info = info;
307 	serr->ee.ee_data = 0;
308 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
309 				   skb_network_header(skb);
310 	serr->port = port;
311 
312 	if (skb_pull(skb, payload - skb->data) != NULL) {
313 		skb_reset_transport_header(skb);
314 		if (sock_queue_err_skb(sk, skb) == 0)
315 			return;
316 	}
317 	kfree_skb(skb);
318 }
319 
320 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
321 {
322 	struct inet_sock *inet = inet_sk(sk);
323 	struct sock_exterr_skb *serr;
324 	struct iphdr *iph;
325 	struct sk_buff *skb;
326 
327 	if (!inet->recverr)
328 		return;
329 
330 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
331 	if (!skb)
332 		return;
333 
334 	skb_put(skb, sizeof(struct iphdr));
335 	skb_reset_network_header(skb);
336 	iph = ip_hdr(skb);
337 	iph->daddr = daddr;
338 
339 	serr = SKB_EXT_ERR(skb);
340 	serr->ee.ee_errno = err;
341 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
342 	serr->ee.ee_type = 0;
343 	serr->ee.ee_code = 0;
344 	serr->ee.ee_pad = 0;
345 	serr->ee.ee_info = info;
346 	serr->ee.ee_data = 0;
347 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
348 	serr->port = port;
349 
350 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
351 	skb_reset_transport_header(skb);
352 
353 	if (sock_queue_err_skb(sk, skb))
354 		kfree_skb(skb);
355 }
356 
357 /*
358  *	Handle MSG_ERRQUEUE
359  */
360 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)
361 {
362 	struct sock_exterr_skb *serr;
363 	struct sk_buff *skb, *skb2;
364 	struct sockaddr_in *sin;
365 	struct {
366 		struct sock_extended_err ee;
367 		struct sockaddr_in	 offender;
368 	} errhdr;
369 	int err;
370 	int copied;
371 
372 	err = -EAGAIN;
373 	skb = skb_dequeue(&sk->sk_error_queue);
374 	if (skb == NULL)
375 		goto out;
376 
377 	copied = skb->len;
378 	if (copied > len) {
379 		msg->msg_flags |= MSG_TRUNC;
380 		copied = len;
381 	}
382 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
383 	if (err)
384 		goto out_free_skb;
385 
386 	sock_recv_timestamp(msg, sk, skb);
387 
388 	serr = SKB_EXT_ERR(skb);
389 
390 	sin = (struct sockaddr_in *)msg->msg_name;
391 	if (sin) {
392 		sin->sin_family = AF_INET;
393 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
394 						   serr->addr_offset);
395 		sin->sin_port = serr->port;
396 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
397 	}
398 
399 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
400 	sin = &errhdr.offender;
401 	sin->sin_family = AF_UNSPEC;
402 	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
403 		struct inet_sock *inet = inet_sk(sk);
404 
405 		sin->sin_family = AF_INET;
406 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
407 		sin->sin_port = 0;
408 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
409 		if (inet->cmsg_flags)
410 			ip_cmsg_recv(msg, skb);
411 	}
412 
413 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
414 
415 	/* Now we could try to dump offended packet options */
416 
417 	msg->msg_flags |= MSG_ERRQUEUE;
418 	err = copied;
419 
420 	/* Reset and regenerate socket error */
421 	spin_lock_bh(&sk->sk_error_queue.lock);
422 	sk->sk_err = 0;
423 	skb2 = skb_peek(&sk->sk_error_queue);
424 	if (skb2 != NULL) {
425 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
426 		spin_unlock_bh(&sk->sk_error_queue.lock);
427 		sk->sk_error_report(sk);
428 	} else
429 		spin_unlock_bh(&sk->sk_error_queue.lock);
430 
431 out_free_skb:
432 	kfree_skb(skb);
433 out:
434 	return err;
435 }
436 
437 
438 /*
439  *	Socket option code for IP. This is the end of the line after any
440  *	TCP,UDP etc options on an IP socket.
441  */
442 
443 static int do_ip_setsockopt(struct sock *sk, int level,
444 			    int optname, char __user *optval, unsigned int optlen)
445 {
446 	struct inet_sock *inet = inet_sk(sk);
447 	int val = 0, err;
448 
449 	if (((1<<optname) & ((1<<IP_PKTINFO) | (1<<IP_RECVTTL) |
450 			     (1<<IP_RECVOPTS) | (1<<IP_RECVTOS) |
451 			     (1<<IP_RETOPTS) | (1<<IP_TOS) |
452 			     (1<<IP_TTL) | (1<<IP_HDRINCL) |
453 			     (1<<IP_MTU_DISCOVER) | (1<<IP_RECVERR) |
454 			     (1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |
455 			     (1<<IP_PASSSEC) | (1<<IP_TRANSPARENT) |
456 			     (1<<IP_MINTTL))) ||
457 	    optname == IP_MULTICAST_TTL ||
458 	    optname == IP_MULTICAST_ALL ||
459 	    optname == IP_MULTICAST_LOOP ||
460 	    optname == IP_RECVORIGDSTADDR) {
461 		if (optlen >= sizeof(int)) {
462 			if (get_user(val, (int __user *) optval))
463 				return -EFAULT;
464 		} else if (optlen >= sizeof(char)) {
465 			unsigned char ucval;
466 
467 			if (get_user(ucval, (unsigned char __user *) optval))
468 				return -EFAULT;
469 			val = (int) ucval;
470 		}
471 	}
472 
473 	/* If optlen==0, it is equivalent to val == 0 */
474 
475 	if (ip_mroute_opt(optname))
476 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
477 
478 	err = 0;
479 	lock_sock(sk);
480 
481 	switch (optname) {
482 	case IP_OPTIONS:
483 	{
484 		struct ip_options *opt = NULL;
485 		if (optlen > 40)
486 			goto e_inval;
487 		err = ip_options_get_from_user(sock_net(sk), &opt,
488 					       optval, optlen);
489 		if (err)
490 			break;
491 		if (inet->is_icsk) {
492 			struct inet_connection_sock *icsk = inet_csk(sk);
493 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
494 			if (sk->sk_family == PF_INET ||
495 			    (!((1 << sk->sk_state) &
496 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
497 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
498 #endif
499 				if (inet->opt)
500 					icsk->icsk_ext_hdr_len -= inet->opt->optlen;
501 				if (opt)
502 					icsk->icsk_ext_hdr_len += opt->optlen;
503 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
504 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
505 			}
506 #endif
507 		}
508 		opt = xchg(&inet->opt, opt);
509 		kfree(opt);
510 		break;
511 	}
512 	case IP_PKTINFO:
513 		if (val)
514 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
515 		else
516 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
517 		break;
518 	case IP_RECVTTL:
519 		if (val)
520 			inet->cmsg_flags |=  IP_CMSG_TTL;
521 		else
522 			inet->cmsg_flags &= ~IP_CMSG_TTL;
523 		break;
524 	case IP_RECVTOS:
525 		if (val)
526 			inet->cmsg_flags |=  IP_CMSG_TOS;
527 		else
528 			inet->cmsg_flags &= ~IP_CMSG_TOS;
529 		break;
530 	case IP_RECVOPTS:
531 		if (val)
532 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
533 		else
534 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
535 		break;
536 	case IP_RETOPTS:
537 		if (val)
538 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
539 		else
540 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
541 		break;
542 	case IP_PASSSEC:
543 		if (val)
544 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
545 		else
546 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
547 		break;
548 	case IP_RECVORIGDSTADDR:
549 		if (val)
550 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
551 		else
552 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
553 		break;
554 	case IP_TOS:	/* This sets both TOS and Precedence */
555 		if (sk->sk_type == SOCK_STREAM) {
556 			val &= ~3;
557 			val |= inet->tos & 3;
558 		}
559 		if (inet->tos != val) {
560 			inet->tos = val;
561 			sk->sk_priority = rt_tos2priority(val);
562 			sk_dst_reset(sk);
563 		}
564 		break;
565 	case IP_TTL:
566 		if (optlen < 1)
567 			goto e_inval;
568 		if (val != -1 && (val < 0 || val > 255))
569 			goto e_inval;
570 		inet->uc_ttl = val;
571 		break;
572 	case IP_HDRINCL:
573 		if (sk->sk_type != SOCK_RAW) {
574 			err = -ENOPROTOOPT;
575 			break;
576 		}
577 		inet->hdrincl = val ? 1 : 0;
578 		break;
579 	case IP_MTU_DISCOVER:
580 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_PROBE)
581 			goto e_inval;
582 		inet->pmtudisc = val;
583 		break;
584 	case IP_RECVERR:
585 		inet->recverr = !!val;
586 		if (!val)
587 			skb_queue_purge(&sk->sk_error_queue);
588 		break;
589 	case IP_MULTICAST_TTL:
590 		if (sk->sk_type == SOCK_STREAM)
591 			goto e_inval;
592 		if (optlen < 1)
593 			goto e_inval;
594 		if (val == -1)
595 			val = 1;
596 		if (val < 0 || val > 255)
597 			goto e_inval;
598 		inet->mc_ttl = val;
599 		break;
600 	case IP_MULTICAST_LOOP:
601 		if (optlen < 1)
602 			goto e_inval;
603 		inet->mc_loop = !!val;
604 		break;
605 	case IP_MULTICAST_IF:
606 	{
607 		struct ip_mreqn mreq;
608 		struct net_device *dev = NULL;
609 
610 		if (sk->sk_type == SOCK_STREAM)
611 			goto e_inval;
612 		/*
613 		 *	Check the arguments are allowable
614 		 */
615 
616 		if (optlen < sizeof(struct in_addr))
617 			goto e_inval;
618 
619 		err = -EFAULT;
620 		if (optlen >= sizeof(struct ip_mreqn)) {
621 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
622 				break;
623 		} else {
624 			memset(&mreq, 0, sizeof(mreq));
625 			if (optlen >= sizeof(struct in_addr) &&
626 			    copy_from_user(&mreq.imr_address, optval,
627 					   sizeof(struct in_addr)))
628 				break;
629 		}
630 
631 		if (!mreq.imr_ifindex) {
632 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
633 				inet->mc_index = 0;
634 				inet->mc_addr  = 0;
635 				err = 0;
636 				break;
637 			}
638 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
639 			if (dev)
640 				mreq.imr_ifindex = dev->ifindex;
641 		} else
642 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
643 
644 
645 		err = -EADDRNOTAVAIL;
646 		if (!dev)
647 			break;
648 		dev_put(dev);
649 
650 		err = -EINVAL;
651 		if (sk->sk_bound_dev_if &&
652 		    mreq.imr_ifindex != sk->sk_bound_dev_if)
653 			break;
654 
655 		inet->mc_index = mreq.imr_ifindex;
656 		inet->mc_addr  = mreq.imr_address.s_addr;
657 		err = 0;
658 		break;
659 	}
660 
661 	case IP_ADD_MEMBERSHIP:
662 	case IP_DROP_MEMBERSHIP:
663 	{
664 		struct ip_mreqn mreq;
665 
666 		err = -EPROTO;
667 		if (inet_sk(sk)->is_icsk)
668 			break;
669 
670 		if (optlen < sizeof(struct ip_mreq))
671 			goto e_inval;
672 		err = -EFAULT;
673 		if (optlen >= sizeof(struct ip_mreqn)) {
674 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
675 				break;
676 		} else {
677 			memset(&mreq, 0, sizeof(mreq));
678 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
679 				break;
680 		}
681 
682 		if (optname == IP_ADD_MEMBERSHIP)
683 			err = ip_mc_join_group(sk, &mreq);
684 		else
685 			err = ip_mc_leave_group(sk, &mreq);
686 		break;
687 	}
688 	case IP_MSFILTER:
689 	{
690 		struct ip_msfilter *msf;
691 
692 		if (optlen < IP_MSFILTER_SIZE(0))
693 			goto e_inval;
694 		if (optlen > sysctl_optmem_max) {
695 			err = -ENOBUFS;
696 			break;
697 		}
698 		msf = kmalloc(optlen, GFP_KERNEL);
699 		if (!msf) {
700 			err = -ENOBUFS;
701 			break;
702 		}
703 		err = -EFAULT;
704 		if (copy_from_user(msf, optval, optlen)) {
705 			kfree(msf);
706 			break;
707 		}
708 		/* numsrc >= (1G-4) overflow in 32 bits */
709 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
710 		    msf->imsf_numsrc > sysctl_igmp_max_msf) {
711 			kfree(msf);
712 			err = -ENOBUFS;
713 			break;
714 		}
715 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
716 			kfree(msf);
717 			err = -EINVAL;
718 			break;
719 		}
720 		err = ip_mc_msfilter(sk, msf, 0);
721 		kfree(msf);
722 		break;
723 	}
724 	case IP_BLOCK_SOURCE:
725 	case IP_UNBLOCK_SOURCE:
726 	case IP_ADD_SOURCE_MEMBERSHIP:
727 	case IP_DROP_SOURCE_MEMBERSHIP:
728 	{
729 		struct ip_mreq_source mreqs;
730 		int omode, add;
731 
732 		if (optlen != sizeof(struct ip_mreq_source))
733 			goto e_inval;
734 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
735 			err = -EFAULT;
736 			break;
737 		}
738 		if (optname == IP_BLOCK_SOURCE) {
739 			omode = MCAST_EXCLUDE;
740 			add = 1;
741 		} else if (optname == IP_UNBLOCK_SOURCE) {
742 			omode = MCAST_EXCLUDE;
743 			add = 0;
744 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
745 			struct ip_mreqn mreq;
746 
747 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
748 			mreq.imr_address.s_addr = mreqs.imr_interface;
749 			mreq.imr_ifindex = 0;
750 			err = ip_mc_join_group(sk, &mreq);
751 			if (err && err != -EADDRINUSE)
752 				break;
753 			omode = MCAST_INCLUDE;
754 			add = 1;
755 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
756 			omode = MCAST_INCLUDE;
757 			add = 0;
758 		}
759 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
760 		break;
761 	}
762 	case MCAST_JOIN_GROUP:
763 	case MCAST_LEAVE_GROUP:
764 	{
765 		struct group_req greq;
766 		struct sockaddr_in *psin;
767 		struct ip_mreqn mreq;
768 
769 		if (optlen < sizeof(struct group_req))
770 			goto e_inval;
771 		err = -EFAULT;
772 		if (copy_from_user(&greq, optval, sizeof(greq)))
773 			break;
774 		psin = (struct sockaddr_in *)&greq.gr_group;
775 		if (psin->sin_family != AF_INET)
776 			goto e_inval;
777 		memset(&mreq, 0, sizeof(mreq));
778 		mreq.imr_multiaddr = psin->sin_addr;
779 		mreq.imr_ifindex = greq.gr_interface;
780 
781 		if (optname == MCAST_JOIN_GROUP)
782 			err = ip_mc_join_group(sk, &mreq);
783 		else
784 			err = ip_mc_leave_group(sk, &mreq);
785 		break;
786 	}
787 	case MCAST_JOIN_SOURCE_GROUP:
788 	case MCAST_LEAVE_SOURCE_GROUP:
789 	case MCAST_BLOCK_SOURCE:
790 	case MCAST_UNBLOCK_SOURCE:
791 	{
792 		struct group_source_req greqs;
793 		struct ip_mreq_source mreqs;
794 		struct sockaddr_in *psin;
795 		int omode, add;
796 
797 		if (optlen != sizeof(struct group_source_req))
798 			goto e_inval;
799 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
800 			err = -EFAULT;
801 			break;
802 		}
803 		if (greqs.gsr_group.ss_family != AF_INET ||
804 		    greqs.gsr_source.ss_family != AF_INET) {
805 			err = -EADDRNOTAVAIL;
806 			break;
807 		}
808 		psin = (struct sockaddr_in *)&greqs.gsr_group;
809 		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
810 		psin = (struct sockaddr_in *)&greqs.gsr_source;
811 		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
812 		mreqs.imr_interface = 0; /* use index for mc_source */
813 
814 		if (optname == MCAST_BLOCK_SOURCE) {
815 			omode = MCAST_EXCLUDE;
816 			add = 1;
817 		} else if (optname == MCAST_UNBLOCK_SOURCE) {
818 			omode = MCAST_EXCLUDE;
819 			add = 0;
820 		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
821 			struct ip_mreqn mreq;
822 
823 			psin = (struct sockaddr_in *)&greqs.gsr_group;
824 			mreq.imr_multiaddr = psin->sin_addr;
825 			mreq.imr_address.s_addr = 0;
826 			mreq.imr_ifindex = greqs.gsr_interface;
827 			err = ip_mc_join_group(sk, &mreq);
828 			if (err && err != -EADDRINUSE)
829 				break;
830 			greqs.gsr_interface = mreq.imr_ifindex;
831 			omode = MCAST_INCLUDE;
832 			add = 1;
833 		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
834 			omode = MCAST_INCLUDE;
835 			add = 0;
836 		}
837 		err = ip_mc_source(add, omode, sk, &mreqs,
838 				   greqs.gsr_interface);
839 		break;
840 	}
841 	case MCAST_MSFILTER:
842 	{
843 		struct sockaddr_in *psin;
844 		struct ip_msfilter *msf = NULL;
845 		struct group_filter *gsf = NULL;
846 		int msize, i, ifindex;
847 
848 		if (optlen < GROUP_FILTER_SIZE(0))
849 			goto e_inval;
850 		if (optlen > sysctl_optmem_max) {
851 			err = -ENOBUFS;
852 			break;
853 		}
854 		gsf = kmalloc(optlen, GFP_KERNEL);
855 		if (!gsf) {
856 			err = -ENOBUFS;
857 			break;
858 		}
859 		err = -EFAULT;
860 		if (copy_from_user(gsf, optval, optlen))
861 			goto mc_msf_out;
862 
863 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
864 		if (gsf->gf_numsrc >= 0x1ffffff ||
865 		    gsf->gf_numsrc > sysctl_igmp_max_msf) {
866 			err = -ENOBUFS;
867 			goto mc_msf_out;
868 		}
869 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
870 			err = -EINVAL;
871 			goto mc_msf_out;
872 		}
873 		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
874 		msf = kmalloc(msize, GFP_KERNEL);
875 		if (!msf) {
876 			err = -ENOBUFS;
877 			goto mc_msf_out;
878 		}
879 		ifindex = gsf->gf_interface;
880 		psin = (struct sockaddr_in *)&gsf->gf_group;
881 		if (psin->sin_family != AF_INET) {
882 			err = -EADDRNOTAVAIL;
883 			goto mc_msf_out;
884 		}
885 		msf->imsf_multiaddr = psin->sin_addr.s_addr;
886 		msf->imsf_interface = 0;
887 		msf->imsf_fmode = gsf->gf_fmode;
888 		msf->imsf_numsrc = gsf->gf_numsrc;
889 		err = -EADDRNOTAVAIL;
890 		for (i = 0; i < gsf->gf_numsrc; ++i) {
891 			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
892 
893 			if (psin->sin_family != AF_INET)
894 				goto mc_msf_out;
895 			msf->imsf_slist[i] = psin->sin_addr.s_addr;
896 		}
897 		kfree(gsf);
898 		gsf = NULL;
899 
900 		err = ip_mc_msfilter(sk, msf, ifindex);
901 mc_msf_out:
902 		kfree(msf);
903 		kfree(gsf);
904 		break;
905 	}
906 	case IP_MULTICAST_ALL:
907 		if (optlen < 1)
908 			goto e_inval;
909 		if (val != 0 && val != 1)
910 			goto e_inval;
911 		inet->mc_all = val;
912 		break;
913 	case IP_ROUTER_ALERT:
914 		err = ip_ra_control(sk, val ? 1 : 0, NULL);
915 		break;
916 
917 	case IP_FREEBIND:
918 		if (optlen < 1)
919 			goto e_inval;
920 		inet->freebind = !!val;
921 		break;
922 
923 	case IP_IPSEC_POLICY:
924 	case IP_XFRM_POLICY:
925 		err = -EPERM;
926 		if (!capable(CAP_NET_ADMIN))
927 			break;
928 		err = xfrm_user_policy(sk, optname, optval, optlen);
929 		break;
930 
931 	case IP_TRANSPARENT:
932 		if (!capable(CAP_NET_ADMIN)) {
933 			err = -EPERM;
934 			break;
935 		}
936 		if (optlen < 1)
937 			goto e_inval;
938 		inet->transparent = !!val;
939 		break;
940 
941 	case IP_MINTTL:
942 		if (optlen < 1)
943 			goto e_inval;
944 		if (val < 0 || val > 255)
945 			goto e_inval;
946 		inet->min_ttl = val;
947 		break;
948 
949 	default:
950 		err = -ENOPROTOOPT;
951 		break;
952 	}
953 	release_sock(sk);
954 	return err;
955 
956 e_inval:
957 	release_sock(sk);
958 	return -EINVAL;
959 }
960 
961 int ip_setsockopt(struct sock *sk, int level,
962 		int optname, char __user *optval, unsigned int optlen)
963 {
964 	int err;
965 
966 	if (level != SOL_IP)
967 		return -ENOPROTOOPT;
968 
969 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
970 #ifdef CONFIG_NETFILTER
971 	/* we need to exclude all possible ENOPROTOOPTs except default case */
972 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
973 			optname != IP_IPSEC_POLICY &&
974 			optname != IP_XFRM_POLICY &&
975 			!ip_mroute_opt(optname)) {
976 		lock_sock(sk);
977 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
978 		release_sock(sk);
979 	}
980 #endif
981 	return err;
982 }
983 EXPORT_SYMBOL(ip_setsockopt);
984 
985 #ifdef CONFIG_COMPAT
986 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
987 			 char __user *optval, unsigned int optlen)
988 {
989 	int err;
990 
991 	if (level != SOL_IP)
992 		return -ENOPROTOOPT;
993 
994 	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
995 		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
996 			ip_setsockopt);
997 
998 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
999 #ifdef CONFIG_NETFILTER
1000 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1001 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1002 			optname != IP_IPSEC_POLICY &&
1003 			optname != IP_XFRM_POLICY &&
1004 			!ip_mroute_opt(optname)) {
1005 		lock_sock(sk);
1006 		err = compat_nf_setsockopt(sk, PF_INET, optname,
1007 					   optval, optlen);
1008 		release_sock(sk);
1009 	}
1010 #endif
1011 	return err;
1012 }
1013 EXPORT_SYMBOL(compat_ip_setsockopt);
1014 #endif
1015 
1016 /*
1017  *	Get the options. Note for future reference. The GET of IP options gets
1018  *	the _received_ ones. The set sets the _sent_ ones.
1019  */
1020 
1021 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1022 			    char __user *optval, int __user *optlen)
1023 {
1024 	struct inet_sock *inet = inet_sk(sk);
1025 	int val;
1026 	int len;
1027 
1028 	if (level != SOL_IP)
1029 		return -EOPNOTSUPP;
1030 
1031 	if (ip_mroute_opt(optname))
1032 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1033 
1034 	if (get_user(len, optlen))
1035 		return -EFAULT;
1036 	if (len < 0)
1037 		return -EINVAL;
1038 
1039 	lock_sock(sk);
1040 
1041 	switch (optname) {
1042 	case IP_OPTIONS:
1043 	{
1044 		unsigned char optbuf[sizeof(struct ip_options)+40];
1045 		struct ip_options * opt = (struct ip_options *)optbuf;
1046 		opt->optlen = 0;
1047 		if (inet->opt)
1048 			memcpy(optbuf, inet->opt,
1049 			       sizeof(struct ip_options)+
1050 			       inet->opt->optlen);
1051 		release_sock(sk);
1052 
1053 		if (opt->optlen == 0)
1054 			return put_user(0, optlen);
1055 
1056 		ip_options_undo(opt);
1057 
1058 		len = min_t(unsigned int, len, opt->optlen);
1059 		if (put_user(len, optlen))
1060 			return -EFAULT;
1061 		if (copy_to_user(optval, opt->__data, len))
1062 			return -EFAULT;
1063 		return 0;
1064 	}
1065 	case IP_PKTINFO:
1066 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1067 		break;
1068 	case IP_RECVTTL:
1069 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1070 		break;
1071 	case IP_RECVTOS:
1072 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1073 		break;
1074 	case IP_RECVOPTS:
1075 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1076 		break;
1077 	case IP_RETOPTS:
1078 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1079 		break;
1080 	case IP_PASSSEC:
1081 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1082 		break;
1083 	case IP_RECVORIGDSTADDR:
1084 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1085 		break;
1086 	case IP_TOS:
1087 		val = inet->tos;
1088 		break;
1089 	case IP_TTL:
1090 		val = (inet->uc_ttl == -1 ?
1091 		       sysctl_ip_default_ttl :
1092 		       inet->uc_ttl);
1093 		break;
1094 	case IP_HDRINCL:
1095 		val = inet->hdrincl;
1096 		break;
1097 	case IP_MTU_DISCOVER:
1098 		val = inet->pmtudisc;
1099 		break;
1100 	case IP_MTU:
1101 	{
1102 		struct dst_entry *dst;
1103 		val = 0;
1104 		dst = sk_dst_get(sk);
1105 		if (dst) {
1106 			val = dst_mtu(dst);
1107 			dst_release(dst);
1108 		}
1109 		if (!val) {
1110 			release_sock(sk);
1111 			return -ENOTCONN;
1112 		}
1113 		break;
1114 	}
1115 	case IP_RECVERR:
1116 		val = inet->recverr;
1117 		break;
1118 	case IP_MULTICAST_TTL:
1119 		val = inet->mc_ttl;
1120 		break;
1121 	case IP_MULTICAST_LOOP:
1122 		val = inet->mc_loop;
1123 		break;
1124 	case IP_MULTICAST_IF:
1125 	{
1126 		struct in_addr addr;
1127 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1128 		addr.s_addr = inet->mc_addr;
1129 		release_sock(sk);
1130 
1131 		if (put_user(len, optlen))
1132 			return -EFAULT;
1133 		if (copy_to_user(optval, &addr, len))
1134 			return -EFAULT;
1135 		return 0;
1136 	}
1137 	case IP_MSFILTER:
1138 	{
1139 		struct ip_msfilter msf;
1140 		int err;
1141 
1142 		if (len < IP_MSFILTER_SIZE(0)) {
1143 			release_sock(sk);
1144 			return -EINVAL;
1145 		}
1146 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1147 			release_sock(sk);
1148 			return -EFAULT;
1149 		}
1150 		err = ip_mc_msfget(sk, &msf,
1151 				   (struct ip_msfilter __user *)optval, optlen);
1152 		release_sock(sk);
1153 		return err;
1154 	}
1155 	case MCAST_MSFILTER:
1156 	{
1157 		struct group_filter gsf;
1158 		int err;
1159 
1160 		if (len < GROUP_FILTER_SIZE(0)) {
1161 			release_sock(sk);
1162 			return -EINVAL;
1163 		}
1164 		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1165 			release_sock(sk);
1166 			return -EFAULT;
1167 		}
1168 		err = ip_mc_gsfget(sk, &gsf,
1169 				   (struct group_filter __user *)optval,
1170 				   optlen);
1171 		release_sock(sk);
1172 		return err;
1173 	}
1174 	case IP_MULTICAST_ALL:
1175 		val = inet->mc_all;
1176 		break;
1177 	case IP_PKTOPTIONS:
1178 	{
1179 		struct msghdr msg;
1180 
1181 		release_sock(sk);
1182 
1183 		if (sk->sk_type != SOCK_STREAM)
1184 			return -ENOPROTOOPT;
1185 
1186 		msg.msg_control = optval;
1187 		msg.msg_controllen = len;
1188 		msg.msg_flags = 0;
1189 
1190 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1191 			struct in_pktinfo info;
1192 
1193 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1194 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1195 			info.ipi_ifindex = inet->mc_index;
1196 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1197 		}
1198 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1199 			int hlim = inet->mc_ttl;
1200 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1201 		}
1202 		len -= msg.msg_controllen;
1203 		return put_user(len, optlen);
1204 	}
1205 	case IP_FREEBIND:
1206 		val = inet->freebind;
1207 		break;
1208 	case IP_TRANSPARENT:
1209 		val = inet->transparent;
1210 		break;
1211 	case IP_MINTTL:
1212 		val = inet->min_ttl;
1213 		break;
1214 	default:
1215 		release_sock(sk);
1216 		return -ENOPROTOOPT;
1217 	}
1218 	release_sock(sk);
1219 
1220 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1221 		unsigned char ucval = (unsigned char)val;
1222 		len = 1;
1223 		if (put_user(len, optlen))
1224 			return -EFAULT;
1225 		if (copy_to_user(optval, &ucval, 1))
1226 			return -EFAULT;
1227 	} else {
1228 		len = min_t(unsigned int, sizeof(int), len);
1229 		if (put_user(len, optlen))
1230 			return -EFAULT;
1231 		if (copy_to_user(optval, &val, len))
1232 			return -EFAULT;
1233 	}
1234 	return 0;
1235 }
1236 
1237 int ip_getsockopt(struct sock *sk, int level,
1238 		  int optname, char __user *optval, int __user *optlen)
1239 {
1240 	int err;
1241 
1242 	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
1243 #ifdef CONFIG_NETFILTER
1244 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1245 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1246 			!ip_mroute_opt(optname)) {
1247 		int len;
1248 
1249 		if (get_user(len, optlen))
1250 			return -EFAULT;
1251 
1252 		lock_sock(sk);
1253 		err = nf_getsockopt(sk, PF_INET, optname, optval,
1254 				&len);
1255 		release_sock(sk);
1256 		if (err >= 0)
1257 			err = put_user(len, optlen);
1258 		return err;
1259 	}
1260 #endif
1261 	return err;
1262 }
1263 EXPORT_SYMBOL(ip_getsockopt);
1264 
1265 #ifdef CONFIG_COMPAT
1266 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1267 			 char __user *optval, int __user *optlen)
1268 {
1269 	int err;
1270 
1271 	if (optname == MCAST_MSFILTER)
1272 		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1273 			ip_getsockopt);
1274 
1275 	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
1276 
1277 #ifdef CONFIG_NETFILTER
1278 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1279 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1280 			!ip_mroute_opt(optname)) {
1281 		int len;
1282 
1283 		if (get_user(len, optlen))
1284 			return -EFAULT;
1285 
1286 		lock_sock(sk);
1287 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1288 		release_sock(sk);
1289 		if (err >= 0)
1290 			err = put_user(len, optlen);
1291 		return err;
1292 	}
1293 #endif
1294 	return err;
1295 }
1296 EXPORT_SYMBOL(compat_ip_getsockopt);
1297 #endif
1298