xref: /openbmc/linux/net/ipv4/ip_sockglue.c (revision 275876e2)
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/inet_ecn.h>
37 #include <net/route.h>
38 #include <net/xfrm.h>
39 #include <net/compat.h>
40 #if IS_ENABLED(CONFIG_IPV6)
41 #include <net/transp_v6.h>
42 #endif
43 #include <net/ip_fib.h>
44 
45 #include <linux/errqueue.h>
46 #include <asm/uaccess.h>
47 
48 #define IP_CMSG_PKTINFO		1
49 #define IP_CMSG_TTL		2
50 #define IP_CMSG_TOS		4
51 #define IP_CMSG_RECVOPTS	8
52 #define IP_CMSG_RETOPTS		16
53 #define IP_CMSG_PASSSEC		32
54 #define IP_CMSG_ORIGDSTADDR     64
55 
56 /*
57  *	SOL_IP control messages.
58  */
59 
60 static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
61 {
62 	struct in_pktinfo info = *PKTINFO_SKB_CB(skb);
63 
64 	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
65 
66 	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
67 }
68 
69 static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
70 {
71 	int ttl = ip_hdr(skb)->ttl;
72 	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
73 }
74 
75 static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
76 {
77 	put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
78 }
79 
80 static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
81 {
82 	if (IPCB(skb)->opt.optlen == 0)
83 		return;
84 
85 	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
86 		 ip_hdr(skb) + 1);
87 }
88 
89 
90 static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
91 {
92 	unsigned char optbuf[sizeof(struct ip_options) + 40];
93 	struct ip_options *opt = (struct ip_options *)optbuf;
94 
95 	if (IPCB(skb)->opt.optlen == 0)
96 		return;
97 
98 	if (ip_options_echo(opt, skb)) {
99 		msg->msg_flags |= MSG_CTRUNC;
100 		return;
101 	}
102 	ip_options_undo(opt);
103 
104 	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
105 }
106 
107 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
108 {
109 	char *secdata;
110 	u32 seclen, secid;
111 	int err;
112 
113 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
114 	if (err)
115 		return;
116 
117 	err = security_secid_to_secctx(secid, &secdata, &seclen);
118 	if (err)
119 		return;
120 
121 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
122 	security_release_secctx(secdata, seclen);
123 }
124 
125 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
126 {
127 	struct sockaddr_in sin;
128 	const struct iphdr *iph = ip_hdr(skb);
129 	__be16 *ports = (__be16 *)skb_transport_header(skb);
130 
131 	if (skb_transport_offset(skb) + 4 > skb->len)
132 		return;
133 
134 	/* All current transport protocols have the port numbers in the
135 	 * first four bytes of the transport header and this function is
136 	 * written with this assumption in mind.
137 	 */
138 
139 	sin.sin_family = AF_INET;
140 	sin.sin_addr.s_addr = iph->daddr;
141 	sin.sin_port = ports[1];
142 	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
143 
144 	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
145 }
146 
147 void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
148 {
149 	struct inet_sock *inet = inet_sk(skb->sk);
150 	unsigned int flags = inet->cmsg_flags;
151 
152 	/* Ordered by supposed usage frequency */
153 	if (flags & 1)
154 		ip_cmsg_recv_pktinfo(msg, skb);
155 	if ((flags >>= 1) == 0)
156 		return;
157 
158 	if (flags & 1)
159 		ip_cmsg_recv_ttl(msg, skb);
160 	if ((flags >>= 1) == 0)
161 		return;
162 
163 	if (flags & 1)
164 		ip_cmsg_recv_tos(msg, skb);
165 	if ((flags >>= 1) == 0)
166 		return;
167 
168 	if (flags & 1)
169 		ip_cmsg_recv_opts(msg, skb);
170 	if ((flags >>= 1) == 0)
171 		return;
172 
173 	if (flags & 1)
174 		ip_cmsg_recv_retopts(msg, skb);
175 	if ((flags >>= 1) == 0)
176 		return;
177 
178 	if (flags & 1)
179 		ip_cmsg_recv_security(msg, skb);
180 
181 	if ((flags >>= 1) == 0)
182 		return;
183 	if (flags & 1)
184 		ip_cmsg_recv_dstaddr(msg, skb);
185 
186 }
187 EXPORT_SYMBOL(ip_cmsg_recv);
188 
189 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc,
190 		 bool allow_ipv6)
191 {
192 	int err, val;
193 	struct cmsghdr *cmsg;
194 
195 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
196 		if (!CMSG_OK(msg, cmsg))
197 			return -EINVAL;
198 #if defined(CONFIG_IPV6)
199 		if (allow_ipv6 &&
200 		    cmsg->cmsg_level == SOL_IPV6 &&
201 		    cmsg->cmsg_type == IPV6_PKTINFO) {
202 			struct in6_pktinfo *src_info;
203 
204 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info)))
205 				return -EINVAL;
206 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
207 			if (!ipv6_addr_v4mapped(&src_info->ipi6_addr))
208 				return -EINVAL;
209 			ipc->oif = src_info->ipi6_ifindex;
210 			ipc->addr = src_info->ipi6_addr.s6_addr32[3];
211 			continue;
212 		}
213 #endif
214 		if (cmsg->cmsg_level != SOL_IP)
215 			continue;
216 		switch (cmsg->cmsg_type) {
217 		case IP_RETOPTS:
218 			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
219 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
220 					     err < 40 ? err : 40);
221 			if (err)
222 				return err;
223 			break;
224 		case IP_PKTINFO:
225 		{
226 			struct in_pktinfo *info;
227 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
228 				return -EINVAL;
229 			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
230 			ipc->oif = info->ipi_ifindex;
231 			ipc->addr = info->ipi_spec_dst.s_addr;
232 			break;
233 		}
234 		case IP_TTL:
235 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
236 				return -EINVAL;
237 			val = *(int *)CMSG_DATA(cmsg);
238 			if (val < 1 || val > 255)
239 				return -EINVAL;
240 			ipc->ttl = val;
241 			break;
242 		case IP_TOS:
243 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
244 				return -EINVAL;
245 			val = *(int *)CMSG_DATA(cmsg);
246 			if (val < 0 || val > 255)
247 				return -EINVAL;
248 			ipc->tos = val;
249 			ipc->priority = rt_tos2priority(ipc->tos);
250 			break;
251 
252 		default:
253 			return -EINVAL;
254 		}
255 	}
256 	return 0;
257 }
258 
259 
260 /* Special input handler for packets caught by router alert option.
261    They are selected only by protocol field, and then processed likely
262    local ones; but only if someone wants them! Otherwise, router
263    not running rsvpd will kill RSVP.
264 
265    It is user level problem, what it will make with them.
266    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
267    but receiver should be enough clever f.e. to forward mtrace requests,
268    sent to multicast group to reach destination designated router.
269  */
270 struct ip_ra_chain __rcu *ip_ra_chain;
271 static DEFINE_SPINLOCK(ip_ra_lock);
272 
273 
274 static void ip_ra_destroy_rcu(struct rcu_head *head)
275 {
276 	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
277 
278 	sock_put(ra->saved_sk);
279 	kfree(ra);
280 }
281 
282 int ip_ra_control(struct sock *sk, unsigned char on,
283 		  void (*destructor)(struct sock *))
284 {
285 	struct ip_ra_chain *ra, *new_ra;
286 	struct ip_ra_chain __rcu **rap;
287 
288 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
289 		return -EINVAL;
290 
291 	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
292 
293 	spin_lock_bh(&ip_ra_lock);
294 	for (rap = &ip_ra_chain;
295 	     (ra = rcu_dereference_protected(*rap,
296 			lockdep_is_held(&ip_ra_lock))) != NULL;
297 	     rap = &ra->next) {
298 		if (ra->sk == sk) {
299 			if (on) {
300 				spin_unlock_bh(&ip_ra_lock);
301 				kfree(new_ra);
302 				return -EADDRINUSE;
303 			}
304 			/* dont let ip_call_ra_chain() use sk again */
305 			ra->sk = NULL;
306 			rcu_assign_pointer(*rap, ra->next);
307 			spin_unlock_bh(&ip_ra_lock);
308 
309 			if (ra->destructor)
310 				ra->destructor(sk);
311 			/*
312 			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
313 			 * period. This guarantee ip_call_ra_chain() dont need
314 			 * to mess with socket refcounts.
315 			 */
316 			ra->saved_sk = sk;
317 			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
318 			return 0;
319 		}
320 	}
321 	if (new_ra == NULL) {
322 		spin_unlock_bh(&ip_ra_lock);
323 		return -ENOBUFS;
324 	}
325 	new_ra->sk = sk;
326 	new_ra->destructor = destructor;
327 
328 	new_ra->next = ra;
329 	rcu_assign_pointer(*rap, new_ra);
330 	sock_hold(sk);
331 	spin_unlock_bh(&ip_ra_lock);
332 
333 	return 0;
334 }
335 
336 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
337 		   __be16 port, u32 info, u8 *payload)
338 {
339 	struct sock_exterr_skb *serr;
340 
341 	skb = skb_clone(skb, GFP_ATOMIC);
342 	if (!skb)
343 		return;
344 
345 	serr = SKB_EXT_ERR(skb);
346 	serr->ee.ee_errno = err;
347 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
348 	serr->ee.ee_type = icmp_hdr(skb)->type;
349 	serr->ee.ee_code = icmp_hdr(skb)->code;
350 	serr->ee.ee_pad = 0;
351 	serr->ee.ee_info = info;
352 	serr->ee.ee_data = 0;
353 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
354 				   skb_network_header(skb);
355 	serr->port = port;
356 
357 	if (skb_pull(skb, payload - skb->data) != NULL) {
358 		skb_reset_transport_header(skb);
359 		if (sock_queue_err_skb(sk, skb) == 0)
360 			return;
361 	}
362 	kfree_skb(skb);
363 }
364 
365 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
366 {
367 	struct inet_sock *inet = inet_sk(sk);
368 	struct sock_exterr_skb *serr;
369 	struct iphdr *iph;
370 	struct sk_buff *skb;
371 
372 	if (!inet->recverr)
373 		return;
374 
375 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
376 	if (!skb)
377 		return;
378 
379 	skb_put(skb, sizeof(struct iphdr));
380 	skb_reset_network_header(skb);
381 	iph = ip_hdr(skb);
382 	iph->daddr = daddr;
383 
384 	serr = SKB_EXT_ERR(skb);
385 	serr->ee.ee_errno = err;
386 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
387 	serr->ee.ee_type = 0;
388 	serr->ee.ee_code = 0;
389 	serr->ee.ee_pad = 0;
390 	serr->ee.ee_info = info;
391 	serr->ee.ee_data = 0;
392 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
393 	serr->port = port;
394 
395 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
396 	skb_reset_transport_header(skb);
397 
398 	if (sock_queue_err_skb(sk, skb))
399 		kfree_skb(skb);
400 }
401 
402 /*
403  *	Handle MSG_ERRQUEUE
404  */
405 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
406 {
407 	struct sock_exterr_skb *serr;
408 	struct sk_buff *skb, *skb2;
409 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
410 	struct {
411 		struct sock_extended_err ee;
412 		struct sockaddr_in	 offender;
413 	} errhdr;
414 	int err;
415 	int copied;
416 
417 	err = -EAGAIN;
418 	skb = skb_dequeue(&sk->sk_error_queue);
419 	if (skb == NULL)
420 		goto out;
421 
422 	copied = skb->len;
423 	if (copied > len) {
424 		msg->msg_flags |= MSG_TRUNC;
425 		copied = len;
426 	}
427 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
428 	if (err)
429 		goto out_free_skb;
430 
431 	sock_recv_timestamp(msg, sk, skb);
432 
433 	serr = SKB_EXT_ERR(skb);
434 
435 	if (sin) {
436 		sin->sin_family = AF_INET;
437 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
438 						   serr->addr_offset);
439 		sin->sin_port = serr->port;
440 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
441 		*addr_len = sizeof(*sin);
442 	}
443 
444 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
445 	sin = &errhdr.offender;
446 	sin->sin_family = AF_UNSPEC;
447 	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
448 		struct inet_sock *inet = inet_sk(sk);
449 
450 		sin->sin_family = AF_INET;
451 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
452 		sin->sin_port = 0;
453 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
454 		if (inet->cmsg_flags)
455 			ip_cmsg_recv(msg, skb);
456 	}
457 
458 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
459 
460 	/* Now we could try to dump offended packet options */
461 
462 	msg->msg_flags |= MSG_ERRQUEUE;
463 	err = copied;
464 
465 	/* Reset and regenerate socket error */
466 	spin_lock_bh(&sk->sk_error_queue.lock);
467 	sk->sk_err = 0;
468 	skb2 = skb_peek(&sk->sk_error_queue);
469 	if (skb2 != NULL) {
470 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
471 		spin_unlock_bh(&sk->sk_error_queue.lock);
472 		sk->sk_error_report(sk);
473 	} else
474 		spin_unlock_bh(&sk->sk_error_queue.lock);
475 
476 out_free_skb:
477 	kfree_skb(skb);
478 out:
479 	return err;
480 }
481 
482 
483 /*
484  *	Socket option code for IP. This is the end of the line after any
485  *	TCP,UDP etc options on an IP socket.
486  */
487 
488 static int do_ip_setsockopt(struct sock *sk, int level,
489 			    int optname, char __user *optval, unsigned int optlen)
490 {
491 	struct inet_sock *inet = inet_sk(sk);
492 	int val = 0, err;
493 
494 	switch (optname) {
495 	case IP_PKTINFO:
496 	case IP_RECVTTL:
497 	case IP_RECVOPTS:
498 	case IP_RECVTOS:
499 	case IP_RETOPTS:
500 	case IP_TOS:
501 	case IP_TTL:
502 	case IP_HDRINCL:
503 	case IP_MTU_DISCOVER:
504 	case IP_RECVERR:
505 	case IP_ROUTER_ALERT:
506 	case IP_FREEBIND:
507 	case IP_PASSSEC:
508 	case IP_TRANSPARENT:
509 	case IP_MINTTL:
510 	case IP_NODEFRAG:
511 	case IP_UNICAST_IF:
512 	case IP_MULTICAST_TTL:
513 	case IP_MULTICAST_ALL:
514 	case IP_MULTICAST_LOOP:
515 	case IP_RECVORIGDSTADDR:
516 		if (optlen >= sizeof(int)) {
517 			if (get_user(val, (int __user *) optval))
518 				return -EFAULT;
519 		} else if (optlen >= sizeof(char)) {
520 			unsigned char ucval;
521 
522 			if (get_user(ucval, (unsigned char __user *) optval))
523 				return -EFAULT;
524 			val = (int) ucval;
525 		}
526 	}
527 
528 	/* If optlen==0, it is equivalent to val == 0 */
529 
530 	if (ip_mroute_opt(optname))
531 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
532 
533 	err = 0;
534 	lock_sock(sk);
535 
536 	switch (optname) {
537 	case IP_OPTIONS:
538 	{
539 		struct ip_options_rcu *old, *opt = NULL;
540 
541 		if (optlen > 40)
542 			goto e_inval;
543 		err = ip_options_get_from_user(sock_net(sk), &opt,
544 					       optval, optlen);
545 		if (err)
546 			break;
547 		old = rcu_dereference_protected(inet->inet_opt,
548 						sock_owned_by_user(sk));
549 		if (inet->is_icsk) {
550 			struct inet_connection_sock *icsk = inet_csk(sk);
551 #if IS_ENABLED(CONFIG_IPV6)
552 			if (sk->sk_family == PF_INET ||
553 			    (!((1 << sk->sk_state) &
554 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
555 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
556 #endif
557 				if (old)
558 					icsk->icsk_ext_hdr_len -= old->opt.optlen;
559 				if (opt)
560 					icsk->icsk_ext_hdr_len += opt->opt.optlen;
561 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
562 #if IS_ENABLED(CONFIG_IPV6)
563 			}
564 #endif
565 		}
566 		rcu_assign_pointer(inet->inet_opt, opt);
567 		if (old)
568 			kfree_rcu(old, rcu);
569 		break;
570 	}
571 	case IP_PKTINFO:
572 		if (val)
573 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
574 		else
575 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
576 		break;
577 	case IP_RECVTTL:
578 		if (val)
579 			inet->cmsg_flags |=  IP_CMSG_TTL;
580 		else
581 			inet->cmsg_flags &= ~IP_CMSG_TTL;
582 		break;
583 	case IP_RECVTOS:
584 		if (val)
585 			inet->cmsg_flags |=  IP_CMSG_TOS;
586 		else
587 			inet->cmsg_flags &= ~IP_CMSG_TOS;
588 		break;
589 	case IP_RECVOPTS:
590 		if (val)
591 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
592 		else
593 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
594 		break;
595 	case IP_RETOPTS:
596 		if (val)
597 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
598 		else
599 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
600 		break;
601 	case IP_PASSSEC:
602 		if (val)
603 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
604 		else
605 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
606 		break;
607 	case IP_RECVORIGDSTADDR:
608 		if (val)
609 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
610 		else
611 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
612 		break;
613 	case IP_TOS:	/* This sets both TOS and Precedence */
614 		if (sk->sk_type == SOCK_STREAM) {
615 			val &= ~INET_ECN_MASK;
616 			val |= inet->tos & INET_ECN_MASK;
617 		}
618 		if (inet->tos != val) {
619 			inet->tos = val;
620 			sk->sk_priority = rt_tos2priority(val);
621 			sk_dst_reset(sk);
622 		}
623 		break;
624 	case IP_TTL:
625 		if (optlen < 1)
626 			goto e_inval;
627 		if (val != -1 && (val < 1 || val > 255))
628 			goto e_inval;
629 		inet->uc_ttl = val;
630 		break;
631 	case IP_HDRINCL:
632 		if (sk->sk_type != SOCK_RAW) {
633 			err = -ENOPROTOOPT;
634 			break;
635 		}
636 		inet->hdrincl = val ? 1 : 0;
637 		break;
638 	case IP_NODEFRAG:
639 		if (sk->sk_type != SOCK_RAW) {
640 			err = -ENOPROTOOPT;
641 			break;
642 		}
643 		inet->nodefrag = val ? 1 : 0;
644 		break;
645 	case IP_MTU_DISCOVER:
646 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
647 			goto e_inval;
648 		inet->pmtudisc = val;
649 		break;
650 	case IP_RECVERR:
651 		inet->recverr = !!val;
652 		if (!val)
653 			skb_queue_purge(&sk->sk_error_queue);
654 		break;
655 	case IP_MULTICAST_TTL:
656 		if (sk->sk_type == SOCK_STREAM)
657 			goto e_inval;
658 		if (optlen < 1)
659 			goto e_inval;
660 		if (val == -1)
661 			val = 1;
662 		if (val < 0 || val > 255)
663 			goto e_inval;
664 		inet->mc_ttl = val;
665 		break;
666 	case IP_MULTICAST_LOOP:
667 		if (optlen < 1)
668 			goto e_inval;
669 		inet->mc_loop = !!val;
670 		break;
671 	case IP_UNICAST_IF:
672 	{
673 		struct net_device *dev = NULL;
674 		int ifindex;
675 
676 		if (optlen != sizeof(int))
677 			goto e_inval;
678 
679 		ifindex = (__force int)ntohl((__force __be32)val);
680 		if (ifindex == 0) {
681 			inet->uc_index = 0;
682 			err = 0;
683 			break;
684 		}
685 
686 		dev = dev_get_by_index(sock_net(sk), ifindex);
687 		err = -EADDRNOTAVAIL;
688 		if (!dev)
689 			break;
690 		dev_put(dev);
691 
692 		err = -EINVAL;
693 		if (sk->sk_bound_dev_if)
694 			break;
695 
696 		inet->uc_index = ifindex;
697 		err = 0;
698 		break;
699 	}
700 	case IP_MULTICAST_IF:
701 	{
702 		struct ip_mreqn mreq;
703 		struct net_device *dev = NULL;
704 
705 		if (sk->sk_type == SOCK_STREAM)
706 			goto e_inval;
707 		/*
708 		 *	Check the arguments are allowable
709 		 */
710 
711 		if (optlen < sizeof(struct in_addr))
712 			goto e_inval;
713 
714 		err = -EFAULT;
715 		if (optlen >= sizeof(struct ip_mreqn)) {
716 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
717 				break;
718 		} else {
719 			memset(&mreq, 0, sizeof(mreq));
720 			if (optlen >= sizeof(struct ip_mreq)) {
721 				if (copy_from_user(&mreq, optval,
722 						   sizeof(struct ip_mreq)))
723 					break;
724 			} else if (optlen >= sizeof(struct in_addr)) {
725 				if (copy_from_user(&mreq.imr_address, optval,
726 						   sizeof(struct in_addr)))
727 					break;
728 			}
729 		}
730 
731 		if (!mreq.imr_ifindex) {
732 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
733 				inet->mc_index = 0;
734 				inet->mc_addr  = 0;
735 				err = 0;
736 				break;
737 			}
738 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
739 			if (dev)
740 				mreq.imr_ifindex = dev->ifindex;
741 		} else
742 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
743 
744 
745 		err = -EADDRNOTAVAIL;
746 		if (!dev)
747 			break;
748 		dev_put(dev);
749 
750 		err = -EINVAL;
751 		if (sk->sk_bound_dev_if &&
752 		    mreq.imr_ifindex != sk->sk_bound_dev_if)
753 			break;
754 
755 		inet->mc_index = mreq.imr_ifindex;
756 		inet->mc_addr  = mreq.imr_address.s_addr;
757 		err = 0;
758 		break;
759 	}
760 
761 	case IP_ADD_MEMBERSHIP:
762 	case IP_DROP_MEMBERSHIP:
763 	{
764 		struct ip_mreqn mreq;
765 
766 		err = -EPROTO;
767 		if (inet_sk(sk)->is_icsk)
768 			break;
769 
770 		if (optlen < sizeof(struct ip_mreq))
771 			goto e_inval;
772 		err = -EFAULT;
773 		if (optlen >= sizeof(struct ip_mreqn)) {
774 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
775 				break;
776 		} else {
777 			memset(&mreq, 0, sizeof(mreq));
778 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
779 				break;
780 		}
781 
782 		if (optname == IP_ADD_MEMBERSHIP)
783 			err = ip_mc_join_group(sk, &mreq);
784 		else
785 			err = ip_mc_leave_group(sk, &mreq);
786 		break;
787 	}
788 	case IP_MSFILTER:
789 	{
790 		struct ip_msfilter *msf;
791 
792 		if (optlen < IP_MSFILTER_SIZE(0))
793 			goto e_inval;
794 		if (optlen > sysctl_optmem_max) {
795 			err = -ENOBUFS;
796 			break;
797 		}
798 		msf = kmalloc(optlen, GFP_KERNEL);
799 		if (!msf) {
800 			err = -ENOBUFS;
801 			break;
802 		}
803 		err = -EFAULT;
804 		if (copy_from_user(msf, optval, optlen)) {
805 			kfree(msf);
806 			break;
807 		}
808 		/* numsrc >= (1G-4) overflow in 32 bits */
809 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
810 		    msf->imsf_numsrc > sysctl_igmp_max_msf) {
811 			kfree(msf);
812 			err = -ENOBUFS;
813 			break;
814 		}
815 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
816 			kfree(msf);
817 			err = -EINVAL;
818 			break;
819 		}
820 		err = ip_mc_msfilter(sk, msf, 0);
821 		kfree(msf);
822 		break;
823 	}
824 	case IP_BLOCK_SOURCE:
825 	case IP_UNBLOCK_SOURCE:
826 	case IP_ADD_SOURCE_MEMBERSHIP:
827 	case IP_DROP_SOURCE_MEMBERSHIP:
828 	{
829 		struct ip_mreq_source mreqs;
830 		int omode, add;
831 
832 		if (optlen != sizeof(struct ip_mreq_source))
833 			goto e_inval;
834 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
835 			err = -EFAULT;
836 			break;
837 		}
838 		if (optname == IP_BLOCK_SOURCE) {
839 			omode = MCAST_EXCLUDE;
840 			add = 1;
841 		} else if (optname == IP_UNBLOCK_SOURCE) {
842 			omode = MCAST_EXCLUDE;
843 			add = 0;
844 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
845 			struct ip_mreqn mreq;
846 
847 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
848 			mreq.imr_address.s_addr = mreqs.imr_interface;
849 			mreq.imr_ifindex = 0;
850 			err = ip_mc_join_group(sk, &mreq);
851 			if (err && err != -EADDRINUSE)
852 				break;
853 			omode = MCAST_INCLUDE;
854 			add = 1;
855 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
856 			omode = MCAST_INCLUDE;
857 			add = 0;
858 		}
859 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
860 		break;
861 	}
862 	case MCAST_JOIN_GROUP:
863 	case MCAST_LEAVE_GROUP:
864 	{
865 		struct group_req greq;
866 		struct sockaddr_in *psin;
867 		struct ip_mreqn mreq;
868 
869 		if (optlen < sizeof(struct group_req))
870 			goto e_inval;
871 		err = -EFAULT;
872 		if (copy_from_user(&greq, optval, sizeof(greq)))
873 			break;
874 		psin = (struct sockaddr_in *)&greq.gr_group;
875 		if (psin->sin_family != AF_INET)
876 			goto e_inval;
877 		memset(&mreq, 0, sizeof(mreq));
878 		mreq.imr_multiaddr = psin->sin_addr;
879 		mreq.imr_ifindex = greq.gr_interface;
880 
881 		if (optname == MCAST_JOIN_GROUP)
882 			err = ip_mc_join_group(sk, &mreq);
883 		else
884 			err = ip_mc_leave_group(sk, &mreq);
885 		break;
886 	}
887 	case MCAST_JOIN_SOURCE_GROUP:
888 	case MCAST_LEAVE_SOURCE_GROUP:
889 	case MCAST_BLOCK_SOURCE:
890 	case MCAST_UNBLOCK_SOURCE:
891 	{
892 		struct group_source_req greqs;
893 		struct ip_mreq_source mreqs;
894 		struct sockaddr_in *psin;
895 		int omode, add;
896 
897 		if (optlen != sizeof(struct group_source_req))
898 			goto e_inval;
899 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
900 			err = -EFAULT;
901 			break;
902 		}
903 		if (greqs.gsr_group.ss_family != AF_INET ||
904 		    greqs.gsr_source.ss_family != AF_INET) {
905 			err = -EADDRNOTAVAIL;
906 			break;
907 		}
908 		psin = (struct sockaddr_in *)&greqs.gsr_group;
909 		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
910 		psin = (struct sockaddr_in *)&greqs.gsr_source;
911 		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
912 		mreqs.imr_interface = 0; /* use index for mc_source */
913 
914 		if (optname == MCAST_BLOCK_SOURCE) {
915 			omode = MCAST_EXCLUDE;
916 			add = 1;
917 		} else if (optname == MCAST_UNBLOCK_SOURCE) {
918 			omode = MCAST_EXCLUDE;
919 			add = 0;
920 		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
921 			struct ip_mreqn mreq;
922 
923 			psin = (struct sockaddr_in *)&greqs.gsr_group;
924 			mreq.imr_multiaddr = psin->sin_addr;
925 			mreq.imr_address.s_addr = 0;
926 			mreq.imr_ifindex = greqs.gsr_interface;
927 			err = ip_mc_join_group(sk, &mreq);
928 			if (err && err != -EADDRINUSE)
929 				break;
930 			greqs.gsr_interface = mreq.imr_ifindex;
931 			omode = MCAST_INCLUDE;
932 			add = 1;
933 		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
934 			omode = MCAST_INCLUDE;
935 			add = 0;
936 		}
937 		err = ip_mc_source(add, omode, sk, &mreqs,
938 				   greqs.gsr_interface);
939 		break;
940 	}
941 	case MCAST_MSFILTER:
942 	{
943 		struct sockaddr_in *psin;
944 		struct ip_msfilter *msf = NULL;
945 		struct group_filter *gsf = NULL;
946 		int msize, i, ifindex;
947 
948 		if (optlen < GROUP_FILTER_SIZE(0))
949 			goto e_inval;
950 		if (optlen > sysctl_optmem_max) {
951 			err = -ENOBUFS;
952 			break;
953 		}
954 		gsf = kmalloc(optlen, GFP_KERNEL);
955 		if (!gsf) {
956 			err = -ENOBUFS;
957 			break;
958 		}
959 		err = -EFAULT;
960 		if (copy_from_user(gsf, optval, optlen))
961 			goto mc_msf_out;
962 
963 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
964 		if (gsf->gf_numsrc >= 0x1ffffff ||
965 		    gsf->gf_numsrc > sysctl_igmp_max_msf) {
966 			err = -ENOBUFS;
967 			goto mc_msf_out;
968 		}
969 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
970 			err = -EINVAL;
971 			goto mc_msf_out;
972 		}
973 		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
974 		msf = kmalloc(msize, GFP_KERNEL);
975 		if (!msf) {
976 			err = -ENOBUFS;
977 			goto mc_msf_out;
978 		}
979 		ifindex = gsf->gf_interface;
980 		psin = (struct sockaddr_in *)&gsf->gf_group;
981 		if (psin->sin_family != AF_INET) {
982 			err = -EADDRNOTAVAIL;
983 			goto mc_msf_out;
984 		}
985 		msf->imsf_multiaddr = psin->sin_addr.s_addr;
986 		msf->imsf_interface = 0;
987 		msf->imsf_fmode = gsf->gf_fmode;
988 		msf->imsf_numsrc = gsf->gf_numsrc;
989 		err = -EADDRNOTAVAIL;
990 		for (i = 0; i < gsf->gf_numsrc; ++i) {
991 			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
992 
993 			if (psin->sin_family != AF_INET)
994 				goto mc_msf_out;
995 			msf->imsf_slist[i] = psin->sin_addr.s_addr;
996 		}
997 		kfree(gsf);
998 		gsf = NULL;
999 
1000 		err = ip_mc_msfilter(sk, msf, ifindex);
1001 mc_msf_out:
1002 		kfree(msf);
1003 		kfree(gsf);
1004 		break;
1005 	}
1006 	case IP_MULTICAST_ALL:
1007 		if (optlen < 1)
1008 			goto e_inval;
1009 		if (val != 0 && val != 1)
1010 			goto e_inval;
1011 		inet->mc_all = val;
1012 		break;
1013 	case IP_ROUTER_ALERT:
1014 		err = ip_ra_control(sk, val ? 1 : 0, NULL);
1015 		break;
1016 
1017 	case IP_FREEBIND:
1018 		if (optlen < 1)
1019 			goto e_inval;
1020 		inet->freebind = !!val;
1021 		break;
1022 
1023 	case IP_IPSEC_POLICY:
1024 	case IP_XFRM_POLICY:
1025 		err = -EPERM;
1026 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1027 			break;
1028 		err = xfrm_user_policy(sk, optname, optval, optlen);
1029 		break;
1030 
1031 	case IP_TRANSPARENT:
1032 		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1033 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1034 			err = -EPERM;
1035 			break;
1036 		}
1037 		if (optlen < 1)
1038 			goto e_inval;
1039 		inet->transparent = !!val;
1040 		break;
1041 
1042 	case IP_MINTTL:
1043 		if (optlen < 1)
1044 			goto e_inval;
1045 		if (val < 0 || val > 255)
1046 			goto e_inval;
1047 		inet->min_ttl = val;
1048 		break;
1049 
1050 	default:
1051 		err = -ENOPROTOOPT;
1052 		break;
1053 	}
1054 	release_sock(sk);
1055 	return err;
1056 
1057 e_inval:
1058 	release_sock(sk);
1059 	return -EINVAL;
1060 }
1061 
1062 /**
1063  * ipv4_pktinfo_prepare - transfert some info from rtable to skb
1064  * @sk: socket
1065  * @skb: buffer
1066  *
1067  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1068  * destination in skb->cb[] before dst drop.
1069  * This way, receiver doesn't make cache line misses to read rtable.
1070  */
1071 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1072 {
1073 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1074 	bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1075 		       ipv6_sk_rxinfo(sk);
1076 
1077 	if (prepare && skb_rtable(skb)) {
1078 		pktinfo->ipi_ifindex = inet_iif(skb);
1079 		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1080 	} else {
1081 		pktinfo->ipi_ifindex = 0;
1082 		pktinfo->ipi_spec_dst.s_addr = 0;
1083 	}
1084 	skb_dst_drop(skb);
1085 }
1086 
1087 int ip_setsockopt(struct sock *sk, int level,
1088 		int optname, char __user *optval, unsigned int optlen)
1089 {
1090 	int err;
1091 
1092 	if (level != SOL_IP)
1093 		return -ENOPROTOOPT;
1094 
1095 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1096 #ifdef CONFIG_NETFILTER
1097 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1098 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1099 			optname != IP_IPSEC_POLICY &&
1100 			optname != IP_XFRM_POLICY &&
1101 			!ip_mroute_opt(optname)) {
1102 		lock_sock(sk);
1103 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1104 		release_sock(sk);
1105 	}
1106 #endif
1107 	return err;
1108 }
1109 EXPORT_SYMBOL(ip_setsockopt);
1110 
1111 #ifdef CONFIG_COMPAT
1112 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1113 			 char __user *optval, unsigned int optlen)
1114 {
1115 	int err;
1116 
1117 	if (level != SOL_IP)
1118 		return -ENOPROTOOPT;
1119 
1120 	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1121 		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1122 			ip_setsockopt);
1123 
1124 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1125 #ifdef CONFIG_NETFILTER
1126 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1127 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1128 			optname != IP_IPSEC_POLICY &&
1129 			optname != IP_XFRM_POLICY &&
1130 			!ip_mroute_opt(optname)) {
1131 		lock_sock(sk);
1132 		err = compat_nf_setsockopt(sk, PF_INET, optname,
1133 					   optval, optlen);
1134 		release_sock(sk);
1135 	}
1136 #endif
1137 	return err;
1138 }
1139 EXPORT_SYMBOL(compat_ip_setsockopt);
1140 #endif
1141 
1142 /*
1143  *	Get the options. Note for future reference. The GET of IP options gets
1144  *	the _received_ ones. The set sets the _sent_ ones.
1145  */
1146 
1147 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1148 			    char __user *optval, int __user *optlen, unsigned int flags)
1149 {
1150 	struct inet_sock *inet = inet_sk(sk);
1151 	int val;
1152 	int len;
1153 
1154 	if (level != SOL_IP)
1155 		return -EOPNOTSUPP;
1156 
1157 	if (ip_mroute_opt(optname))
1158 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1159 
1160 	if (get_user(len, optlen))
1161 		return -EFAULT;
1162 	if (len < 0)
1163 		return -EINVAL;
1164 
1165 	lock_sock(sk);
1166 
1167 	switch (optname) {
1168 	case IP_OPTIONS:
1169 	{
1170 		unsigned char optbuf[sizeof(struct ip_options)+40];
1171 		struct ip_options *opt = (struct ip_options *)optbuf;
1172 		struct ip_options_rcu *inet_opt;
1173 
1174 		inet_opt = rcu_dereference_protected(inet->inet_opt,
1175 						     sock_owned_by_user(sk));
1176 		opt->optlen = 0;
1177 		if (inet_opt)
1178 			memcpy(optbuf, &inet_opt->opt,
1179 			       sizeof(struct ip_options) +
1180 			       inet_opt->opt.optlen);
1181 		release_sock(sk);
1182 
1183 		if (opt->optlen == 0)
1184 			return put_user(0, optlen);
1185 
1186 		ip_options_undo(opt);
1187 
1188 		len = min_t(unsigned int, len, opt->optlen);
1189 		if (put_user(len, optlen))
1190 			return -EFAULT;
1191 		if (copy_to_user(optval, opt->__data, len))
1192 			return -EFAULT;
1193 		return 0;
1194 	}
1195 	case IP_PKTINFO:
1196 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1197 		break;
1198 	case IP_RECVTTL:
1199 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1200 		break;
1201 	case IP_RECVTOS:
1202 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1203 		break;
1204 	case IP_RECVOPTS:
1205 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1206 		break;
1207 	case IP_RETOPTS:
1208 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1209 		break;
1210 	case IP_PASSSEC:
1211 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1212 		break;
1213 	case IP_RECVORIGDSTADDR:
1214 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1215 		break;
1216 	case IP_TOS:
1217 		val = inet->tos;
1218 		break;
1219 	case IP_TTL:
1220 		val = (inet->uc_ttl == -1 ?
1221 		       sysctl_ip_default_ttl :
1222 		       inet->uc_ttl);
1223 		break;
1224 	case IP_HDRINCL:
1225 		val = inet->hdrincl;
1226 		break;
1227 	case IP_NODEFRAG:
1228 		val = inet->nodefrag;
1229 		break;
1230 	case IP_MTU_DISCOVER:
1231 		val = inet->pmtudisc;
1232 		break;
1233 	case IP_MTU:
1234 	{
1235 		struct dst_entry *dst;
1236 		val = 0;
1237 		dst = sk_dst_get(sk);
1238 		if (dst) {
1239 			val = dst_mtu(dst);
1240 			dst_release(dst);
1241 		}
1242 		if (!val) {
1243 			release_sock(sk);
1244 			return -ENOTCONN;
1245 		}
1246 		break;
1247 	}
1248 	case IP_RECVERR:
1249 		val = inet->recverr;
1250 		break;
1251 	case IP_MULTICAST_TTL:
1252 		val = inet->mc_ttl;
1253 		break;
1254 	case IP_MULTICAST_LOOP:
1255 		val = inet->mc_loop;
1256 		break;
1257 	case IP_UNICAST_IF:
1258 		val = (__force int)htonl((__u32) inet->uc_index);
1259 		break;
1260 	case IP_MULTICAST_IF:
1261 	{
1262 		struct in_addr addr;
1263 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1264 		addr.s_addr = inet->mc_addr;
1265 		release_sock(sk);
1266 
1267 		if (put_user(len, optlen))
1268 			return -EFAULT;
1269 		if (copy_to_user(optval, &addr, len))
1270 			return -EFAULT;
1271 		return 0;
1272 	}
1273 	case IP_MSFILTER:
1274 	{
1275 		struct ip_msfilter msf;
1276 		int err;
1277 
1278 		if (len < IP_MSFILTER_SIZE(0)) {
1279 			release_sock(sk);
1280 			return -EINVAL;
1281 		}
1282 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1283 			release_sock(sk);
1284 			return -EFAULT;
1285 		}
1286 		err = ip_mc_msfget(sk, &msf,
1287 				   (struct ip_msfilter __user *)optval, optlen);
1288 		release_sock(sk);
1289 		return err;
1290 	}
1291 	case MCAST_MSFILTER:
1292 	{
1293 		struct group_filter gsf;
1294 		int err;
1295 
1296 		if (len < GROUP_FILTER_SIZE(0)) {
1297 			release_sock(sk);
1298 			return -EINVAL;
1299 		}
1300 		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1301 			release_sock(sk);
1302 			return -EFAULT;
1303 		}
1304 		err = ip_mc_gsfget(sk, &gsf,
1305 				   (struct group_filter __user *)optval,
1306 				   optlen);
1307 		release_sock(sk);
1308 		return err;
1309 	}
1310 	case IP_MULTICAST_ALL:
1311 		val = inet->mc_all;
1312 		break;
1313 	case IP_PKTOPTIONS:
1314 	{
1315 		struct msghdr msg;
1316 
1317 		release_sock(sk);
1318 
1319 		if (sk->sk_type != SOCK_STREAM)
1320 			return -ENOPROTOOPT;
1321 
1322 		msg.msg_control = (__force void *) optval;
1323 		msg.msg_controllen = len;
1324 		msg.msg_flags = flags;
1325 
1326 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1327 			struct in_pktinfo info;
1328 
1329 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1330 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1331 			info.ipi_ifindex = inet->mc_index;
1332 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1333 		}
1334 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1335 			int hlim = inet->mc_ttl;
1336 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1337 		}
1338 		if (inet->cmsg_flags & IP_CMSG_TOS) {
1339 			int tos = inet->rcv_tos;
1340 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1341 		}
1342 		len -= msg.msg_controllen;
1343 		return put_user(len, optlen);
1344 	}
1345 	case IP_FREEBIND:
1346 		val = inet->freebind;
1347 		break;
1348 	case IP_TRANSPARENT:
1349 		val = inet->transparent;
1350 		break;
1351 	case IP_MINTTL:
1352 		val = inet->min_ttl;
1353 		break;
1354 	default:
1355 		release_sock(sk);
1356 		return -ENOPROTOOPT;
1357 	}
1358 	release_sock(sk);
1359 
1360 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1361 		unsigned char ucval = (unsigned char)val;
1362 		len = 1;
1363 		if (put_user(len, optlen))
1364 			return -EFAULT;
1365 		if (copy_to_user(optval, &ucval, 1))
1366 			return -EFAULT;
1367 	} else {
1368 		len = min_t(unsigned int, sizeof(int), len);
1369 		if (put_user(len, optlen))
1370 			return -EFAULT;
1371 		if (copy_to_user(optval, &val, len))
1372 			return -EFAULT;
1373 	}
1374 	return 0;
1375 }
1376 
1377 int ip_getsockopt(struct sock *sk, int level,
1378 		  int optname, char __user *optval, int __user *optlen)
1379 {
1380 	int err;
1381 
1382 	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1383 #ifdef CONFIG_NETFILTER
1384 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1385 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1386 			!ip_mroute_opt(optname)) {
1387 		int len;
1388 
1389 		if (get_user(len, optlen))
1390 			return -EFAULT;
1391 
1392 		lock_sock(sk);
1393 		err = nf_getsockopt(sk, PF_INET, optname, optval,
1394 				&len);
1395 		release_sock(sk);
1396 		if (err >= 0)
1397 			err = put_user(len, optlen);
1398 		return err;
1399 	}
1400 #endif
1401 	return err;
1402 }
1403 EXPORT_SYMBOL(ip_getsockopt);
1404 
1405 #ifdef CONFIG_COMPAT
1406 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1407 			 char __user *optval, int __user *optlen)
1408 {
1409 	int err;
1410 
1411 	if (optname == MCAST_MSFILTER)
1412 		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1413 			ip_getsockopt);
1414 
1415 	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1416 		MSG_CMSG_COMPAT);
1417 
1418 #ifdef CONFIG_NETFILTER
1419 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1420 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1421 			!ip_mroute_opt(optname)) {
1422 		int len;
1423 
1424 		if (get_user(len, optlen))
1425 			return -EFAULT;
1426 
1427 		lock_sock(sk);
1428 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1429 		release_sock(sk);
1430 		if (err >= 0)
1431 			err = put_user(len, optlen);
1432 		return err;
1433 	}
1434 #endif
1435 	return err;
1436 }
1437 EXPORT_SYMBOL(compat_ip_getsockopt);
1438 #endif
1439