xref: /linux/net/ipv4/ip_sockglue.c (revision b3b77c8caef1750ebeea1054e39e358550ea9f55)
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 sock_exterr_skb *serr;
291 
292 	skb = skb_clone(skb, GFP_ATOMIC);
293 	if (!skb)
294 		return;
295 
296 	serr = SKB_EXT_ERR(skb);
297 	serr->ee.ee_errno = err;
298 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
299 	serr->ee.ee_type = icmp_hdr(skb)->type;
300 	serr->ee.ee_code = icmp_hdr(skb)->code;
301 	serr->ee.ee_pad = 0;
302 	serr->ee.ee_info = info;
303 	serr->ee.ee_data = 0;
304 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
305 				   skb_network_header(skb);
306 	serr->port = port;
307 
308 	if (skb_pull(skb, payload - skb->data) != NULL) {
309 		skb_reset_transport_header(skb);
310 		if (sock_queue_err_skb(sk, skb) == 0)
311 			return;
312 	}
313 	kfree_skb(skb);
314 }
315 
316 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
317 {
318 	struct inet_sock *inet = inet_sk(sk);
319 	struct sock_exterr_skb *serr;
320 	struct iphdr *iph;
321 	struct sk_buff *skb;
322 
323 	if (!inet->recverr)
324 		return;
325 
326 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
327 	if (!skb)
328 		return;
329 
330 	skb_put(skb, sizeof(struct iphdr));
331 	skb_reset_network_header(skb);
332 	iph = ip_hdr(skb);
333 	iph->daddr = daddr;
334 
335 	serr = SKB_EXT_ERR(skb);
336 	serr->ee.ee_errno = err;
337 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
338 	serr->ee.ee_type = 0;
339 	serr->ee.ee_code = 0;
340 	serr->ee.ee_pad = 0;
341 	serr->ee.ee_info = info;
342 	serr->ee.ee_data = 0;
343 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
344 	serr->port = port;
345 
346 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
347 	skb_reset_transport_header(skb);
348 
349 	if (sock_queue_err_skb(sk, skb))
350 		kfree_skb(skb);
351 }
352 
353 /*
354  *	Handle MSG_ERRQUEUE
355  */
356 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)
357 {
358 	struct sock_exterr_skb *serr;
359 	struct sk_buff *skb, *skb2;
360 	struct sockaddr_in *sin;
361 	struct {
362 		struct sock_extended_err ee;
363 		struct sockaddr_in	 offender;
364 	} errhdr;
365 	int err;
366 	int copied;
367 
368 	err = -EAGAIN;
369 	skb = skb_dequeue(&sk->sk_error_queue);
370 	if (skb == NULL)
371 		goto out;
372 
373 	copied = skb->len;
374 	if (copied > len) {
375 		msg->msg_flags |= MSG_TRUNC;
376 		copied = len;
377 	}
378 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
379 	if (err)
380 		goto out_free_skb;
381 
382 	sock_recv_timestamp(msg, sk, skb);
383 
384 	serr = SKB_EXT_ERR(skb);
385 
386 	sin = (struct sockaddr_in *)msg->msg_name;
387 	if (sin) {
388 		sin->sin_family = AF_INET;
389 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
390 						   serr->addr_offset);
391 		sin->sin_port = serr->port;
392 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
393 	}
394 
395 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
396 	sin = &errhdr.offender;
397 	sin->sin_family = AF_UNSPEC;
398 	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
399 		struct inet_sock *inet = inet_sk(sk);
400 
401 		sin->sin_family = AF_INET;
402 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
403 		sin->sin_port = 0;
404 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
405 		if (inet->cmsg_flags)
406 			ip_cmsg_recv(msg, skb);
407 	}
408 
409 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
410 
411 	/* Now we could try to dump offended packet options */
412 
413 	msg->msg_flags |= MSG_ERRQUEUE;
414 	err = copied;
415 
416 	/* Reset and regenerate socket error */
417 	spin_lock_bh(&sk->sk_error_queue.lock);
418 	sk->sk_err = 0;
419 	skb2 = skb_peek(&sk->sk_error_queue);
420 	if (skb2 != NULL) {
421 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
422 		spin_unlock_bh(&sk->sk_error_queue.lock);
423 		sk->sk_error_report(sk);
424 	} else
425 		spin_unlock_bh(&sk->sk_error_queue.lock);
426 
427 out_free_skb:
428 	kfree_skb(skb);
429 out:
430 	return err;
431 }
432 
433 
434 /*
435  *	Socket option code for IP. This is the end of the line after any
436  *	TCP,UDP etc options on an IP socket.
437  */
438 
439 static int do_ip_setsockopt(struct sock *sk, int level,
440 			    int optname, char __user *optval, unsigned int optlen)
441 {
442 	struct inet_sock *inet = inet_sk(sk);
443 	int val = 0, err;
444 
445 	if (((1<<optname) & ((1<<IP_PKTINFO) | (1<<IP_RECVTTL) |
446 			     (1<<IP_RECVOPTS) | (1<<IP_RECVTOS) |
447 			     (1<<IP_RETOPTS) | (1<<IP_TOS) |
448 			     (1<<IP_TTL) | (1<<IP_HDRINCL) |
449 			     (1<<IP_MTU_DISCOVER) | (1<<IP_RECVERR) |
450 			     (1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |
451 			     (1<<IP_PASSSEC) | (1<<IP_TRANSPARENT) |
452 			     (1<<IP_MINTTL))) ||
453 	    optname == IP_MULTICAST_TTL ||
454 	    optname == IP_MULTICAST_ALL ||
455 	    optname == IP_MULTICAST_LOOP ||
456 	    optname == IP_RECVORIGDSTADDR) {
457 		if (optlen >= sizeof(int)) {
458 			if (get_user(val, (int __user *) optval))
459 				return -EFAULT;
460 		} else if (optlen >= sizeof(char)) {
461 			unsigned char ucval;
462 
463 			if (get_user(ucval, (unsigned char __user *) optval))
464 				return -EFAULT;
465 			val = (int) ucval;
466 		}
467 	}
468 
469 	/* If optlen==0, it is equivalent to val == 0 */
470 
471 	if (ip_mroute_opt(optname))
472 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
473 
474 	err = 0;
475 	lock_sock(sk);
476 
477 	switch (optname) {
478 	case IP_OPTIONS:
479 	{
480 		struct ip_options *opt = NULL;
481 		if (optlen > 40)
482 			goto e_inval;
483 		err = ip_options_get_from_user(sock_net(sk), &opt,
484 					       optval, optlen);
485 		if (err)
486 			break;
487 		if (inet->is_icsk) {
488 			struct inet_connection_sock *icsk = inet_csk(sk);
489 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
490 			if (sk->sk_family == PF_INET ||
491 			    (!((1 << sk->sk_state) &
492 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
493 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
494 #endif
495 				if (inet->opt)
496 					icsk->icsk_ext_hdr_len -= inet->opt->optlen;
497 				if (opt)
498 					icsk->icsk_ext_hdr_len += opt->optlen;
499 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
500 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
501 			}
502 #endif
503 		}
504 		opt = xchg(&inet->opt, opt);
505 		kfree(opt);
506 		break;
507 	}
508 	case IP_PKTINFO:
509 		if (val)
510 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
511 		else
512 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
513 		break;
514 	case IP_RECVTTL:
515 		if (val)
516 			inet->cmsg_flags |=  IP_CMSG_TTL;
517 		else
518 			inet->cmsg_flags &= ~IP_CMSG_TTL;
519 		break;
520 	case IP_RECVTOS:
521 		if (val)
522 			inet->cmsg_flags |=  IP_CMSG_TOS;
523 		else
524 			inet->cmsg_flags &= ~IP_CMSG_TOS;
525 		break;
526 	case IP_RECVOPTS:
527 		if (val)
528 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
529 		else
530 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
531 		break;
532 	case IP_RETOPTS:
533 		if (val)
534 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
535 		else
536 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
537 		break;
538 	case IP_PASSSEC:
539 		if (val)
540 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
541 		else
542 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
543 		break;
544 	case IP_RECVORIGDSTADDR:
545 		if (val)
546 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
547 		else
548 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
549 		break;
550 	case IP_TOS:	/* This sets both TOS and Precedence */
551 		if (sk->sk_type == SOCK_STREAM) {
552 			val &= ~3;
553 			val |= inet->tos & 3;
554 		}
555 		if (inet->tos != val) {
556 			inet->tos = val;
557 			sk->sk_priority = rt_tos2priority(val);
558 			sk_dst_reset(sk);
559 		}
560 		break;
561 	case IP_TTL:
562 		if (optlen < 1)
563 			goto e_inval;
564 		if (val != -1 && (val < 0 || val > 255))
565 			goto e_inval;
566 		inet->uc_ttl = val;
567 		break;
568 	case IP_HDRINCL:
569 		if (sk->sk_type != SOCK_RAW) {
570 			err = -ENOPROTOOPT;
571 			break;
572 		}
573 		inet->hdrincl = val ? 1 : 0;
574 		break;
575 	case IP_MTU_DISCOVER:
576 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_PROBE)
577 			goto e_inval;
578 		inet->pmtudisc = val;
579 		break;
580 	case IP_RECVERR:
581 		inet->recverr = !!val;
582 		if (!val)
583 			skb_queue_purge(&sk->sk_error_queue);
584 		break;
585 	case IP_MULTICAST_TTL:
586 		if (sk->sk_type == SOCK_STREAM)
587 			goto e_inval;
588 		if (optlen < 1)
589 			goto e_inval;
590 		if (val == -1)
591 			val = 1;
592 		if (val < 0 || val > 255)
593 			goto e_inval;
594 		inet->mc_ttl = val;
595 		break;
596 	case IP_MULTICAST_LOOP:
597 		if (optlen < 1)
598 			goto e_inval;
599 		inet->mc_loop = !!val;
600 		break;
601 	case IP_MULTICAST_IF:
602 	{
603 		struct ip_mreqn mreq;
604 		struct net_device *dev = NULL;
605 
606 		if (sk->sk_type == SOCK_STREAM)
607 			goto e_inval;
608 		/*
609 		 *	Check the arguments are allowable
610 		 */
611 
612 		if (optlen < sizeof(struct in_addr))
613 			goto e_inval;
614 
615 		err = -EFAULT;
616 		if (optlen >= sizeof(struct ip_mreqn)) {
617 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
618 				break;
619 		} else {
620 			memset(&mreq, 0, sizeof(mreq));
621 			if (optlen >= sizeof(struct in_addr) &&
622 			    copy_from_user(&mreq.imr_address, optval,
623 					   sizeof(struct in_addr)))
624 				break;
625 		}
626 
627 		if (!mreq.imr_ifindex) {
628 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
629 				inet->mc_index = 0;
630 				inet->mc_addr  = 0;
631 				err = 0;
632 				break;
633 			}
634 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
635 			if (dev)
636 				mreq.imr_ifindex = dev->ifindex;
637 		} else
638 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
639 
640 
641 		err = -EADDRNOTAVAIL;
642 		if (!dev)
643 			break;
644 		dev_put(dev);
645 
646 		err = -EINVAL;
647 		if (sk->sk_bound_dev_if &&
648 		    mreq.imr_ifindex != sk->sk_bound_dev_if)
649 			break;
650 
651 		inet->mc_index = mreq.imr_ifindex;
652 		inet->mc_addr  = mreq.imr_address.s_addr;
653 		err = 0;
654 		break;
655 	}
656 
657 	case IP_ADD_MEMBERSHIP:
658 	case IP_DROP_MEMBERSHIP:
659 	{
660 		struct ip_mreqn mreq;
661 
662 		err = -EPROTO;
663 		if (inet_sk(sk)->is_icsk)
664 			break;
665 
666 		if (optlen < sizeof(struct ip_mreq))
667 			goto e_inval;
668 		err = -EFAULT;
669 		if (optlen >= sizeof(struct ip_mreqn)) {
670 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
671 				break;
672 		} else {
673 			memset(&mreq, 0, sizeof(mreq));
674 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
675 				break;
676 		}
677 
678 		if (optname == IP_ADD_MEMBERSHIP)
679 			err = ip_mc_join_group(sk, &mreq);
680 		else
681 			err = ip_mc_leave_group(sk, &mreq);
682 		break;
683 	}
684 	case IP_MSFILTER:
685 	{
686 		struct ip_msfilter *msf;
687 
688 		if (optlen < IP_MSFILTER_SIZE(0))
689 			goto e_inval;
690 		if (optlen > sysctl_optmem_max) {
691 			err = -ENOBUFS;
692 			break;
693 		}
694 		msf = kmalloc(optlen, GFP_KERNEL);
695 		if (!msf) {
696 			err = -ENOBUFS;
697 			break;
698 		}
699 		err = -EFAULT;
700 		if (copy_from_user(msf, optval, optlen)) {
701 			kfree(msf);
702 			break;
703 		}
704 		/* numsrc >= (1G-4) overflow in 32 bits */
705 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
706 		    msf->imsf_numsrc > sysctl_igmp_max_msf) {
707 			kfree(msf);
708 			err = -ENOBUFS;
709 			break;
710 		}
711 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
712 			kfree(msf);
713 			err = -EINVAL;
714 			break;
715 		}
716 		err = ip_mc_msfilter(sk, msf, 0);
717 		kfree(msf);
718 		break;
719 	}
720 	case IP_BLOCK_SOURCE:
721 	case IP_UNBLOCK_SOURCE:
722 	case IP_ADD_SOURCE_MEMBERSHIP:
723 	case IP_DROP_SOURCE_MEMBERSHIP:
724 	{
725 		struct ip_mreq_source mreqs;
726 		int omode, add;
727 
728 		if (optlen != sizeof(struct ip_mreq_source))
729 			goto e_inval;
730 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
731 			err = -EFAULT;
732 			break;
733 		}
734 		if (optname == IP_BLOCK_SOURCE) {
735 			omode = MCAST_EXCLUDE;
736 			add = 1;
737 		} else if (optname == IP_UNBLOCK_SOURCE) {
738 			omode = MCAST_EXCLUDE;
739 			add = 0;
740 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
741 			struct ip_mreqn mreq;
742 
743 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
744 			mreq.imr_address.s_addr = mreqs.imr_interface;
745 			mreq.imr_ifindex = 0;
746 			err = ip_mc_join_group(sk, &mreq);
747 			if (err && err != -EADDRINUSE)
748 				break;
749 			omode = MCAST_INCLUDE;
750 			add = 1;
751 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
752 			omode = MCAST_INCLUDE;
753 			add = 0;
754 		}
755 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
756 		break;
757 	}
758 	case MCAST_JOIN_GROUP:
759 	case MCAST_LEAVE_GROUP:
760 	{
761 		struct group_req greq;
762 		struct sockaddr_in *psin;
763 		struct ip_mreqn mreq;
764 
765 		if (optlen < sizeof(struct group_req))
766 			goto e_inval;
767 		err = -EFAULT;
768 		if (copy_from_user(&greq, optval, sizeof(greq)))
769 			break;
770 		psin = (struct sockaddr_in *)&greq.gr_group;
771 		if (psin->sin_family != AF_INET)
772 			goto e_inval;
773 		memset(&mreq, 0, sizeof(mreq));
774 		mreq.imr_multiaddr = psin->sin_addr;
775 		mreq.imr_ifindex = greq.gr_interface;
776 
777 		if (optname == MCAST_JOIN_GROUP)
778 			err = ip_mc_join_group(sk, &mreq);
779 		else
780 			err = ip_mc_leave_group(sk, &mreq);
781 		break;
782 	}
783 	case MCAST_JOIN_SOURCE_GROUP:
784 	case MCAST_LEAVE_SOURCE_GROUP:
785 	case MCAST_BLOCK_SOURCE:
786 	case MCAST_UNBLOCK_SOURCE:
787 	{
788 		struct group_source_req greqs;
789 		struct ip_mreq_source mreqs;
790 		struct sockaddr_in *psin;
791 		int omode, add;
792 
793 		if (optlen != sizeof(struct group_source_req))
794 			goto e_inval;
795 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
796 			err = -EFAULT;
797 			break;
798 		}
799 		if (greqs.gsr_group.ss_family != AF_INET ||
800 		    greqs.gsr_source.ss_family != AF_INET) {
801 			err = -EADDRNOTAVAIL;
802 			break;
803 		}
804 		psin = (struct sockaddr_in *)&greqs.gsr_group;
805 		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
806 		psin = (struct sockaddr_in *)&greqs.gsr_source;
807 		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
808 		mreqs.imr_interface = 0; /* use index for mc_source */
809 
810 		if (optname == MCAST_BLOCK_SOURCE) {
811 			omode = MCAST_EXCLUDE;
812 			add = 1;
813 		} else if (optname == MCAST_UNBLOCK_SOURCE) {
814 			omode = MCAST_EXCLUDE;
815 			add = 0;
816 		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
817 			struct ip_mreqn mreq;
818 
819 			psin = (struct sockaddr_in *)&greqs.gsr_group;
820 			mreq.imr_multiaddr = psin->sin_addr;
821 			mreq.imr_address.s_addr = 0;
822 			mreq.imr_ifindex = greqs.gsr_interface;
823 			err = ip_mc_join_group(sk, &mreq);
824 			if (err && err != -EADDRINUSE)
825 				break;
826 			greqs.gsr_interface = mreq.imr_ifindex;
827 			omode = MCAST_INCLUDE;
828 			add = 1;
829 		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
830 			omode = MCAST_INCLUDE;
831 			add = 0;
832 		}
833 		err = ip_mc_source(add, omode, sk, &mreqs,
834 				   greqs.gsr_interface);
835 		break;
836 	}
837 	case MCAST_MSFILTER:
838 	{
839 		struct sockaddr_in *psin;
840 		struct ip_msfilter *msf = NULL;
841 		struct group_filter *gsf = NULL;
842 		int msize, i, ifindex;
843 
844 		if (optlen < GROUP_FILTER_SIZE(0))
845 			goto e_inval;
846 		if (optlen > sysctl_optmem_max) {
847 			err = -ENOBUFS;
848 			break;
849 		}
850 		gsf = kmalloc(optlen, GFP_KERNEL);
851 		if (!gsf) {
852 			err = -ENOBUFS;
853 			break;
854 		}
855 		err = -EFAULT;
856 		if (copy_from_user(gsf, optval, optlen))
857 			goto mc_msf_out;
858 
859 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
860 		if (gsf->gf_numsrc >= 0x1ffffff ||
861 		    gsf->gf_numsrc > sysctl_igmp_max_msf) {
862 			err = -ENOBUFS;
863 			goto mc_msf_out;
864 		}
865 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
866 			err = -EINVAL;
867 			goto mc_msf_out;
868 		}
869 		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
870 		msf = kmalloc(msize, GFP_KERNEL);
871 		if (!msf) {
872 			err = -ENOBUFS;
873 			goto mc_msf_out;
874 		}
875 		ifindex = gsf->gf_interface;
876 		psin = (struct sockaddr_in *)&gsf->gf_group;
877 		if (psin->sin_family != AF_INET) {
878 			err = -EADDRNOTAVAIL;
879 			goto mc_msf_out;
880 		}
881 		msf->imsf_multiaddr = psin->sin_addr.s_addr;
882 		msf->imsf_interface = 0;
883 		msf->imsf_fmode = gsf->gf_fmode;
884 		msf->imsf_numsrc = gsf->gf_numsrc;
885 		err = -EADDRNOTAVAIL;
886 		for (i = 0; i < gsf->gf_numsrc; ++i) {
887 			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
888 
889 			if (psin->sin_family != AF_INET)
890 				goto mc_msf_out;
891 			msf->imsf_slist[i] = psin->sin_addr.s_addr;
892 		}
893 		kfree(gsf);
894 		gsf = NULL;
895 
896 		err = ip_mc_msfilter(sk, msf, ifindex);
897 mc_msf_out:
898 		kfree(msf);
899 		kfree(gsf);
900 		break;
901 	}
902 	case IP_MULTICAST_ALL:
903 		if (optlen < 1)
904 			goto e_inval;
905 		if (val != 0 && val != 1)
906 			goto e_inval;
907 		inet->mc_all = val;
908 		break;
909 	case IP_ROUTER_ALERT:
910 		err = ip_ra_control(sk, val ? 1 : 0, NULL);
911 		break;
912 
913 	case IP_FREEBIND:
914 		if (optlen < 1)
915 			goto e_inval;
916 		inet->freebind = !!val;
917 		break;
918 
919 	case IP_IPSEC_POLICY:
920 	case IP_XFRM_POLICY:
921 		err = -EPERM;
922 		if (!capable(CAP_NET_ADMIN))
923 			break;
924 		err = xfrm_user_policy(sk, optname, optval, optlen);
925 		break;
926 
927 	case IP_TRANSPARENT:
928 		if (!capable(CAP_NET_ADMIN)) {
929 			err = -EPERM;
930 			break;
931 		}
932 		if (optlen < 1)
933 			goto e_inval;
934 		inet->transparent = !!val;
935 		break;
936 
937 	case IP_MINTTL:
938 		if (optlen < 1)
939 			goto e_inval;
940 		if (val < 0 || val > 255)
941 			goto e_inval;
942 		inet->min_ttl = val;
943 		break;
944 
945 	default:
946 		err = -ENOPROTOOPT;
947 		break;
948 	}
949 	release_sock(sk);
950 	return err;
951 
952 e_inval:
953 	release_sock(sk);
954 	return -EINVAL;
955 }
956 
957 /**
958  * ip_queue_rcv_skb - Queue an skb into sock receive queue
959  * @sk: socket
960  * @skb: buffer
961  *
962  * Queues an skb into socket receive queue. If IP_CMSG_PKTINFO option
963  * is not set, we drop skb dst entry now, while dst cache line is hot.
964  */
965 int ip_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
966 {
967 	if (!(inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO))
968 		skb_dst_drop(skb);
969 	return sock_queue_rcv_skb(sk, skb);
970 }
971 EXPORT_SYMBOL(ip_queue_rcv_skb);
972 
973 int ip_setsockopt(struct sock *sk, int level,
974 		int optname, char __user *optval, unsigned int optlen)
975 {
976 	int err;
977 
978 	if (level != SOL_IP)
979 		return -ENOPROTOOPT;
980 
981 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
982 #ifdef CONFIG_NETFILTER
983 	/* we need to exclude all possible ENOPROTOOPTs except default case */
984 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
985 			optname != IP_IPSEC_POLICY &&
986 			optname != IP_XFRM_POLICY &&
987 			!ip_mroute_opt(optname)) {
988 		lock_sock(sk);
989 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
990 		release_sock(sk);
991 	}
992 #endif
993 	return err;
994 }
995 EXPORT_SYMBOL(ip_setsockopt);
996 
997 #ifdef CONFIG_COMPAT
998 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
999 			 char __user *optval, unsigned int optlen)
1000 {
1001 	int err;
1002 
1003 	if (level != SOL_IP)
1004 		return -ENOPROTOOPT;
1005 
1006 	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1007 		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1008 			ip_setsockopt);
1009 
1010 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1011 #ifdef CONFIG_NETFILTER
1012 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1013 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1014 			optname != IP_IPSEC_POLICY &&
1015 			optname != IP_XFRM_POLICY &&
1016 			!ip_mroute_opt(optname)) {
1017 		lock_sock(sk);
1018 		err = compat_nf_setsockopt(sk, PF_INET, optname,
1019 					   optval, optlen);
1020 		release_sock(sk);
1021 	}
1022 #endif
1023 	return err;
1024 }
1025 EXPORT_SYMBOL(compat_ip_setsockopt);
1026 #endif
1027 
1028 /*
1029  *	Get the options. Note for future reference. The GET of IP options gets
1030  *	the _received_ ones. The set sets the _sent_ ones.
1031  */
1032 
1033 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1034 			    char __user *optval, int __user *optlen)
1035 {
1036 	struct inet_sock *inet = inet_sk(sk);
1037 	int val;
1038 	int len;
1039 
1040 	if (level != SOL_IP)
1041 		return -EOPNOTSUPP;
1042 
1043 	if (ip_mroute_opt(optname))
1044 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1045 
1046 	if (get_user(len, optlen))
1047 		return -EFAULT;
1048 	if (len < 0)
1049 		return -EINVAL;
1050 
1051 	lock_sock(sk);
1052 
1053 	switch (optname) {
1054 	case IP_OPTIONS:
1055 	{
1056 		unsigned char optbuf[sizeof(struct ip_options)+40];
1057 		struct ip_options * opt = (struct ip_options *)optbuf;
1058 		opt->optlen = 0;
1059 		if (inet->opt)
1060 			memcpy(optbuf, inet->opt,
1061 			       sizeof(struct ip_options)+
1062 			       inet->opt->optlen);
1063 		release_sock(sk);
1064 
1065 		if (opt->optlen == 0)
1066 			return put_user(0, optlen);
1067 
1068 		ip_options_undo(opt);
1069 
1070 		len = min_t(unsigned int, len, opt->optlen);
1071 		if (put_user(len, optlen))
1072 			return -EFAULT;
1073 		if (copy_to_user(optval, opt->__data, len))
1074 			return -EFAULT;
1075 		return 0;
1076 	}
1077 	case IP_PKTINFO:
1078 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1079 		break;
1080 	case IP_RECVTTL:
1081 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1082 		break;
1083 	case IP_RECVTOS:
1084 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1085 		break;
1086 	case IP_RECVOPTS:
1087 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1088 		break;
1089 	case IP_RETOPTS:
1090 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1091 		break;
1092 	case IP_PASSSEC:
1093 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1094 		break;
1095 	case IP_RECVORIGDSTADDR:
1096 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1097 		break;
1098 	case IP_TOS:
1099 		val = inet->tos;
1100 		break;
1101 	case IP_TTL:
1102 		val = (inet->uc_ttl == -1 ?
1103 		       sysctl_ip_default_ttl :
1104 		       inet->uc_ttl);
1105 		break;
1106 	case IP_HDRINCL:
1107 		val = inet->hdrincl;
1108 		break;
1109 	case IP_MTU_DISCOVER:
1110 		val = inet->pmtudisc;
1111 		break;
1112 	case IP_MTU:
1113 	{
1114 		struct dst_entry *dst;
1115 		val = 0;
1116 		dst = sk_dst_get(sk);
1117 		if (dst) {
1118 			val = dst_mtu(dst);
1119 			dst_release(dst);
1120 		}
1121 		if (!val) {
1122 			release_sock(sk);
1123 			return -ENOTCONN;
1124 		}
1125 		break;
1126 	}
1127 	case IP_RECVERR:
1128 		val = inet->recverr;
1129 		break;
1130 	case IP_MULTICAST_TTL:
1131 		val = inet->mc_ttl;
1132 		break;
1133 	case IP_MULTICAST_LOOP:
1134 		val = inet->mc_loop;
1135 		break;
1136 	case IP_MULTICAST_IF:
1137 	{
1138 		struct in_addr addr;
1139 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1140 		addr.s_addr = inet->mc_addr;
1141 		release_sock(sk);
1142 
1143 		if (put_user(len, optlen))
1144 			return -EFAULT;
1145 		if (copy_to_user(optval, &addr, len))
1146 			return -EFAULT;
1147 		return 0;
1148 	}
1149 	case IP_MSFILTER:
1150 	{
1151 		struct ip_msfilter msf;
1152 		int err;
1153 
1154 		if (len < IP_MSFILTER_SIZE(0)) {
1155 			release_sock(sk);
1156 			return -EINVAL;
1157 		}
1158 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1159 			release_sock(sk);
1160 			return -EFAULT;
1161 		}
1162 		err = ip_mc_msfget(sk, &msf,
1163 				   (struct ip_msfilter __user *)optval, optlen);
1164 		release_sock(sk);
1165 		return err;
1166 	}
1167 	case MCAST_MSFILTER:
1168 	{
1169 		struct group_filter gsf;
1170 		int err;
1171 
1172 		if (len < GROUP_FILTER_SIZE(0)) {
1173 			release_sock(sk);
1174 			return -EINVAL;
1175 		}
1176 		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1177 			release_sock(sk);
1178 			return -EFAULT;
1179 		}
1180 		err = ip_mc_gsfget(sk, &gsf,
1181 				   (struct group_filter __user *)optval,
1182 				   optlen);
1183 		release_sock(sk);
1184 		return err;
1185 	}
1186 	case IP_MULTICAST_ALL:
1187 		val = inet->mc_all;
1188 		break;
1189 	case IP_PKTOPTIONS:
1190 	{
1191 		struct msghdr msg;
1192 
1193 		release_sock(sk);
1194 
1195 		if (sk->sk_type != SOCK_STREAM)
1196 			return -ENOPROTOOPT;
1197 
1198 		msg.msg_control = optval;
1199 		msg.msg_controllen = len;
1200 		msg.msg_flags = 0;
1201 
1202 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1203 			struct in_pktinfo info;
1204 
1205 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1206 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1207 			info.ipi_ifindex = inet->mc_index;
1208 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1209 		}
1210 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1211 			int hlim = inet->mc_ttl;
1212 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1213 		}
1214 		len -= msg.msg_controllen;
1215 		return put_user(len, optlen);
1216 	}
1217 	case IP_FREEBIND:
1218 		val = inet->freebind;
1219 		break;
1220 	case IP_TRANSPARENT:
1221 		val = inet->transparent;
1222 		break;
1223 	case IP_MINTTL:
1224 		val = inet->min_ttl;
1225 		break;
1226 	default:
1227 		release_sock(sk);
1228 		return -ENOPROTOOPT;
1229 	}
1230 	release_sock(sk);
1231 
1232 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1233 		unsigned char ucval = (unsigned char)val;
1234 		len = 1;
1235 		if (put_user(len, optlen))
1236 			return -EFAULT;
1237 		if (copy_to_user(optval, &ucval, 1))
1238 			return -EFAULT;
1239 	} else {
1240 		len = min_t(unsigned int, sizeof(int), len);
1241 		if (put_user(len, optlen))
1242 			return -EFAULT;
1243 		if (copy_to_user(optval, &val, len))
1244 			return -EFAULT;
1245 	}
1246 	return 0;
1247 }
1248 
1249 int ip_getsockopt(struct sock *sk, int level,
1250 		  int optname, char __user *optval, int __user *optlen)
1251 {
1252 	int err;
1253 
1254 	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
1255 #ifdef CONFIG_NETFILTER
1256 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1257 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1258 			!ip_mroute_opt(optname)) {
1259 		int len;
1260 
1261 		if (get_user(len, optlen))
1262 			return -EFAULT;
1263 
1264 		lock_sock(sk);
1265 		err = nf_getsockopt(sk, PF_INET, optname, optval,
1266 				&len);
1267 		release_sock(sk);
1268 		if (err >= 0)
1269 			err = put_user(len, optlen);
1270 		return err;
1271 	}
1272 #endif
1273 	return err;
1274 }
1275 EXPORT_SYMBOL(ip_getsockopt);
1276 
1277 #ifdef CONFIG_COMPAT
1278 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1279 			 char __user *optval, int __user *optlen)
1280 {
1281 	int err;
1282 
1283 	if (optname == MCAST_MSFILTER)
1284 		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1285 			ip_getsockopt);
1286 
1287 	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
1288 
1289 #ifdef CONFIG_NETFILTER
1290 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1291 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1292 			!ip_mroute_opt(optname)) {
1293 		int len;
1294 
1295 		if (get_user(len, optlen))
1296 			return -EFAULT;
1297 
1298 		lock_sock(sk);
1299 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1300 		release_sock(sk);
1301 		if (err >= 0)
1302 			err = put_user(len, optlen);
1303 		return err;
1304 	}
1305 #endif
1306 	return err;
1307 }
1308 EXPORT_SYMBOL(compat_ip_getsockopt);
1309 #endif
1310