xref: /linux/net/ipv4/ip_sockglue.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 #define PKTINFO_SKB_CB(__skb) ((struct in_pktinfo *)((__skb)->cb))
60 
61 static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
62 {
63 	struct in_pktinfo info = *PKTINFO_SKB_CB(skb);
64 
65 	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
66 
67 	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
68 }
69 
70 static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
71 {
72 	int ttl = ip_hdr(skb)->ttl;
73 	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
74 }
75 
76 static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
77 {
78 	put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
79 }
80 
81 static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
82 {
83 	if (IPCB(skb)->opt.optlen == 0)
84 		return;
85 
86 	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
87 		 ip_hdr(skb) + 1);
88 }
89 
90 
91 static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
92 {
93 	unsigned char optbuf[sizeof(struct ip_options) + 40];
94 	struct ip_options *opt = (struct ip_options *)optbuf;
95 
96 	if (IPCB(skb)->opt.optlen == 0)
97 		return;
98 
99 	if (ip_options_echo(opt, skb)) {
100 		msg->msg_flags |= MSG_CTRUNC;
101 		return;
102 	}
103 	ip_options_undo(opt);
104 
105 	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
106 }
107 
108 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
109 {
110 	char *secdata;
111 	u32 seclen, secid;
112 	int err;
113 
114 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
115 	if (err)
116 		return;
117 
118 	err = security_secid_to_secctx(secid, &secdata, &seclen);
119 	if (err)
120 		return;
121 
122 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
123 	security_release_secctx(secdata, seclen);
124 }
125 
126 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
127 {
128 	struct sockaddr_in sin;
129 	const struct iphdr *iph = ip_hdr(skb);
130 	__be16 *ports = (__be16 *)skb_transport_header(skb);
131 
132 	if (skb_transport_offset(skb) + 4 > skb->len)
133 		return;
134 
135 	/* All current transport protocols have the port numbers in the
136 	 * first four bytes of the transport header and this function is
137 	 * written with this assumption in mind.
138 	 */
139 
140 	sin.sin_family = AF_INET;
141 	sin.sin_addr.s_addr = iph->daddr;
142 	sin.sin_port = ports[1];
143 	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
144 
145 	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
146 }
147 
148 void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
149 {
150 	struct inet_sock *inet = inet_sk(skb->sk);
151 	unsigned int flags = inet->cmsg_flags;
152 
153 	/* Ordered by supposed usage frequency */
154 	if (flags & 1)
155 		ip_cmsg_recv_pktinfo(msg, skb);
156 	if ((flags >>= 1) == 0)
157 		return;
158 
159 	if (flags & 1)
160 		ip_cmsg_recv_ttl(msg, skb);
161 	if ((flags >>= 1) == 0)
162 		return;
163 
164 	if (flags & 1)
165 		ip_cmsg_recv_tos(msg, skb);
166 	if ((flags >>= 1) == 0)
167 		return;
168 
169 	if (flags & 1)
170 		ip_cmsg_recv_opts(msg, skb);
171 	if ((flags >>= 1) == 0)
172 		return;
173 
174 	if (flags & 1)
175 		ip_cmsg_recv_retopts(msg, skb);
176 	if ((flags >>= 1) == 0)
177 		return;
178 
179 	if (flags & 1)
180 		ip_cmsg_recv_security(msg, skb);
181 
182 	if ((flags >>= 1) == 0)
183 		return;
184 	if (flags & 1)
185 		ip_cmsg_recv_dstaddr(msg, skb);
186 
187 }
188 EXPORT_SYMBOL(ip_cmsg_recv);
189 
190 int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc)
191 {
192 	int err;
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 (cmsg->cmsg_level != SOL_IP)
199 			continue;
200 		switch (cmsg->cmsg_type) {
201 		case IP_RETOPTS:
202 			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
203 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
204 					     err < 40 ? err : 40);
205 			if (err)
206 				return err;
207 			break;
208 		case IP_PKTINFO:
209 		{
210 			struct in_pktinfo *info;
211 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
212 				return -EINVAL;
213 			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
214 			ipc->oif = info->ipi_ifindex;
215 			ipc->addr = info->ipi_spec_dst.s_addr;
216 			break;
217 		}
218 		default:
219 			return -EINVAL;
220 		}
221 	}
222 	return 0;
223 }
224 
225 
226 /* Special input handler for packets caught by router alert option.
227    They are selected only by protocol field, and then processed likely
228    local ones; but only if someone wants them! Otherwise, router
229    not running rsvpd will kill RSVP.
230 
231    It is user level problem, what it will make with them.
232    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
233    but receiver should be enough clever f.e. to forward mtrace requests,
234    sent to multicast group to reach destination designated router.
235  */
236 struct ip_ra_chain __rcu *ip_ra_chain;
237 static DEFINE_SPINLOCK(ip_ra_lock);
238 
239 
240 static void ip_ra_destroy_rcu(struct rcu_head *head)
241 {
242 	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
243 
244 	sock_put(ra->saved_sk);
245 	kfree(ra);
246 }
247 
248 int ip_ra_control(struct sock *sk, unsigned char on,
249 		  void (*destructor)(struct sock *))
250 {
251 	struct ip_ra_chain *ra, *new_ra;
252 	struct ip_ra_chain __rcu **rap;
253 
254 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
255 		return -EINVAL;
256 
257 	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
258 
259 	spin_lock_bh(&ip_ra_lock);
260 	for (rap = &ip_ra_chain;
261 	     (ra = rcu_dereference_protected(*rap,
262 			lockdep_is_held(&ip_ra_lock))) != NULL;
263 	     rap = &ra->next) {
264 		if (ra->sk == sk) {
265 			if (on) {
266 				spin_unlock_bh(&ip_ra_lock);
267 				kfree(new_ra);
268 				return -EADDRINUSE;
269 			}
270 			/* dont let ip_call_ra_chain() use sk again */
271 			ra->sk = NULL;
272 			rcu_assign_pointer(*rap, ra->next);
273 			spin_unlock_bh(&ip_ra_lock);
274 
275 			if (ra->destructor)
276 				ra->destructor(sk);
277 			/*
278 			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
279 			 * period. This guarantee ip_call_ra_chain() dont need
280 			 * to mess with socket refcounts.
281 			 */
282 			ra->saved_sk = sk;
283 			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
284 			return 0;
285 		}
286 	}
287 	if (new_ra == NULL) {
288 		spin_unlock_bh(&ip_ra_lock);
289 		return -ENOBUFS;
290 	}
291 	new_ra->sk = sk;
292 	new_ra->destructor = destructor;
293 
294 	new_ra->next = ra;
295 	rcu_assign_pointer(*rap, new_ra);
296 	sock_hold(sk);
297 	spin_unlock_bh(&ip_ra_lock);
298 
299 	return 0;
300 }
301 
302 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
303 		   __be16 port, u32 info, u8 *payload)
304 {
305 	struct sock_exterr_skb *serr;
306 
307 	skb = skb_clone(skb, GFP_ATOMIC);
308 	if (!skb)
309 		return;
310 
311 	serr = SKB_EXT_ERR(skb);
312 	serr->ee.ee_errno = err;
313 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
314 	serr->ee.ee_type = icmp_hdr(skb)->type;
315 	serr->ee.ee_code = icmp_hdr(skb)->code;
316 	serr->ee.ee_pad = 0;
317 	serr->ee.ee_info = info;
318 	serr->ee.ee_data = 0;
319 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
320 				   skb_network_header(skb);
321 	serr->port = port;
322 
323 	if (skb_pull(skb, payload - skb->data) != NULL) {
324 		skb_reset_transport_header(skb);
325 		if (sock_queue_err_skb(sk, skb) == 0)
326 			return;
327 	}
328 	kfree_skb(skb);
329 }
330 
331 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
332 {
333 	struct inet_sock *inet = inet_sk(sk);
334 	struct sock_exterr_skb *serr;
335 	struct iphdr *iph;
336 	struct sk_buff *skb;
337 
338 	if (!inet->recverr)
339 		return;
340 
341 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
342 	if (!skb)
343 		return;
344 
345 	skb_put(skb, sizeof(struct iphdr));
346 	skb_reset_network_header(skb);
347 	iph = ip_hdr(skb);
348 	iph->daddr = daddr;
349 
350 	serr = SKB_EXT_ERR(skb);
351 	serr->ee.ee_errno = err;
352 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
353 	serr->ee.ee_type = 0;
354 	serr->ee.ee_code = 0;
355 	serr->ee.ee_pad = 0;
356 	serr->ee.ee_info = info;
357 	serr->ee.ee_data = 0;
358 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
359 	serr->port = port;
360 
361 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
362 	skb_reset_transport_header(skb);
363 
364 	if (sock_queue_err_skb(sk, skb))
365 		kfree_skb(skb);
366 }
367 
368 /*
369  *	Handle MSG_ERRQUEUE
370  */
371 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)
372 {
373 	struct sock_exterr_skb *serr;
374 	struct sk_buff *skb, *skb2;
375 	struct sockaddr_in *sin;
376 	struct {
377 		struct sock_extended_err ee;
378 		struct sockaddr_in	 offender;
379 	} errhdr;
380 	int err;
381 	int copied;
382 
383 	err = -EAGAIN;
384 	skb = skb_dequeue(&sk->sk_error_queue);
385 	if (skb == NULL)
386 		goto out;
387 
388 	copied = skb->len;
389 	if (copied > len) {
390 		msg->msg_flags |= MSG_TRUNC;
391 		copied = len;
392 	}
393 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
394 	if (err)
395 		goto out_free_skb;
396 
397 	sock_recv_timestamp(msg, sk, skb);
398 
399 	serr = SKB_EXT_ERR(skb);
400 
401 	sin = (struct sockaddr_in *)msg->msg_name;
402 	if (sin) {
403 		sin->sin_family = AF_INET;
404 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
405 						   serr->addr_offset);
406 		sin->sin_port = serr->port;
407 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
408 	}
409 
410 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
411 	sin = &errhdr.offender;
412 	sin->sin_family = AF_UNSPEC;
413 	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
414 		struct inet_sock *inet = inet_sk(sk);
415 
416 		sin->sin_family = AF_INET;
417 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
418 		sin->sin_port = 0;
419 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
420 		if (inet->cmsg_flags)
421 			ip_cmsg_recv(msg, skb);
422 	}
423 
424 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
425 
426 	/* Now we could try to dump offended packet options */
427 
428 	msg->msg_flags |= MSG_ERRQUEUE;
429 	err = copied;
430 
431 	/* Reset and regenerate socket error */
432 	spin_lock_bh(&sk->sk_error_queue.lock);
433 	sk->sk_err = 0;
434 	skb2 = skb_peek(&sk->sk_error_queue);
435 	if (skb2 != NULL) {
436 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
437 		spin_unlock_bh(&sk->sk_error_queue.lock);
438 		sk->sk_error_report(sk);
439 	} else
440 		spin_unlock_bh(&sk->sk_error_queue.lock);
441 
442 out_free_skb:
443 	kfree_skb(skb);
444 out:
445 	return err;
446 }
447 
448 
449 /*
450  *	Socket option code for IP. This is the end of the line after any
451  *	TCP,UDP etc options on an IP socket.
452  */
453 
454 static int do_ip_setsockopt(struct sock *sk, int level,
455 			    int optname, char __user *optval, unsigned int optlen)
456 {
457 	struct inet_sock *inet = inet_sk(sk);
458 	int val = 0, err;
459 
460 	switch (optname) {
461 	case IP_PKTINFO:
462 	case IP_RECVTTL:
463 	case IP_RECVOPTS:
464 	case IP_RECVTOS:
465 	case IP_RETOPTS:
466 	case IP_TOS:
467 	case IP_TTL:
468 	case IP_HDRINCL:
469 	case IP_MTU_DISCOVER:
470 	case IP_RECVERR:
471 	case IP_ROUTER_ALERT:
472 	case IP_FREEBIND:
473 	case IP_PASSSEC:
474 	case IP_TRANSPARENT:
475 	case IP_MINTTL:
476 	case IP_NODEFRAG:
477 	case IP_UNICAST_IF:
478 	case IP_MULTICAST_TTL:
479 	case IP_MULTICAST_ALL:
480 	case IP_MULTICAST_LOOP:
481 	case IP_RECVORIGDSTADDR:
482 		if (optlen >= sizeof(int)) {
483 			if (get_user(val, (int __user *) optval))
484 				return -EFAULT;
485 		} else if (optlen >= sizeof(char)) {
486 			unsigned char ucval;
487 
488 			if (get_user(ucval, (unsigned char __user *) optval))
489 				return -EFAULT;
490 			val = (int) ucval;
491 		}
492 	}
493 
494 	/* If optlen==0, it is equivalent to val == 0 */
495 
496 	if (ip_mroute_opt(optname))
497 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
498 
499 	err = 0;
500 	lock_sock(sk);
501 
502 	switch (optname) {
503 	case IP_OPTIONS:
504 	{
505 		struct ip_options_rcu *old, *opt = NULL;
506 
507 		if (optlen > 40)
508 			goto e_inval;
509 		err = ip_options_get_from_user(sock_net(sk), &opt,
510 					       optval, optlen);
511 		if (err)
512 			break;
513 		old = rcu_dereference_protected(inet->inet_opt,
514 						sock_owned_by_user(sk));
515 		if (inet->is_icsk) {
516 			struct inet_connection_sock *icsk = inet_csk(sk);
517 #if IS_ENABLED(CONFIG_IPV6)
518 			if (sk->sk_family == PF_INET ||
519 			    (!((1 << sk->sk_state) &
520 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
521 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
522 #endif
523 				if (old)
524 					icsk->icsk_ext_hdr_len -= old->opt.optlen;
525 				if (opt)
526 					icsk->icsk_ext_hdr_len += opt->opt.optlen;
527 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
528 #if IS_ENABLED(CONFIG_IPV6)
529 			}
530 #endif
531 		}
532 		rcu_assign_pointer(inet->inet_opt, opt);
533 		if (old)
534 			kfree_rcu(old, rcu);
535 		break;
536 	}
537 	case IP_PKTINFO:
538 		if (val)
539 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
540 		else
541 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
542 		break;
543 	case IP_RECVTTL:
544 		if (val)
545 			inet->cmsg_flags |=  IP_CMSG_TTL;
546 		else
547 			inet->cmsg_flags &= ~IP_CMSG_TTL;
548 		break;
549 	case IP_RECVTOS:
550 		if (val)
551 			inet->cmsg_flags |=  IP_CMSG_TOS;
552 		else
553 			inet->cmsg_flags &= ~IP_CMSG_TOS;
554 		break;
555 	case IP_RECVOPTS:
556 		if (val)
557 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
558 		else
559 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
560 		break;
561 	case IP_RETOPTS:
562 		if (val)
563 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
564 		else
565 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
566 		break;
567 	case IP_PASSSEC:
568 		if (val)
569 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
570 		else
571 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
572 		break;
573 	case IP_RECVORIGDSTADDR:
574 		if (val)
575 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
576 		else
577 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
578 		break;
579 	case IP_TOS:	/* This sets both TOS and Precedence */
580 		if (sk->sk_type == SOCK_STREAM) {
581 			val &= ~INET_ECN_MASK;
582 			val |= inet->tos & INET_ECN_MASK;
583 		}
584 		if (inet->tos != val) {
585 			inet->tos = val;
586 			sk->sk_priority = rt_tos2priority(val);
587 			sk_dst_reset(sk);
588 		}
589 		break;
590 	case IP_TTL:
591 		if (optlen < 1)
592 			goto e_inval;
593 		if (val != -1 && (val < 0 || val > 255))
594 			goto e_inval;
595 		inet->uc_ttl = val;
596 		break;
597 	case IP_HDRINCL:
598 		if (sk->sk_type != SOCK_RAW) {
599 			err = -ENOPROTOOPT;
600 			break;
601 		}
602 		inet->hdrincl = val ? 1 : 0;
603 		break;
604 	case IP_NODEFRAG:
605 		if (sk->sk_type != SOCK_RAW) {
606 			err = -ENOPROTOOPT;
607 			break;
608 		}
609 		inet->nodefrag = val ? 1 : 0;
610 		break;
611 	case IP_MTU_DISCOVER:
612 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_PROBE)
613 			goto e_inval;
614 		inet->pmtudisc = val;
615 		break;
616 	case IP_RECVERR:
617 		inet->recverr = !!val;
618 		if (!val)
619 			skb_queue_purge(&sk->sk_error_queue);
620 		break;
621 	case IP_MULTICAST_TTL:
622 		if (sk->sk_type == SOCK_STREAM)
623 			goto e_inval;
624 		if (optlen < 1)
625 			goto e_inval;
626 		if (val == -1)
627 			val = 1;
628 		if (val < 0 || val > 255)
629 			goto e_inval;
630 		inet->mc_ttl = val;
631 		break;
632 	case IP_MULTICAST_LOOP:
633 		if (optlen < 1)
634 			goto e_inval;
635 		inet->mc_loop = !!val;
636 		break;
637 	case IP_UNICAST_IF:
638 	{
639 		struct net_device *dev = NULL;
640 		int ifindex;
641 
642 		if (optlen != sizeof(int))
643 			goto e_inval;
644 
645 		ifindex = (__force int)ntohl((__force __be32)val);
646 		if (ifindex == 0) {
647 			inet->uc_index = 0;
648 			err = 0;
649 			break;
650 		}
651 
652 		dev = dev_get_by_index(sock_net(sk), ifindex);
653 		err = -EADDRNOTAVAIL;
654 		if (!dev)
655 			break;
656 		dev_put(dev);
657 
658 		err = -EINVAL;
659 		if (sk->sk_bound_dev_if)
660 			break;
661 
662 		inet->uc_index = ifindex;
663 		err = 0;
664 		break;
665 	}
666 	case IP_MULTICAST_IF:
667 	{
668 		struct ip_mreqn mreq;
669 		struct net_device *dev = NULL;
670 
671 		if (sk->sk_type == SOCK_STREAM)
672 			goto e_inval;
673 		/*
674 		 *	Check the arguments are allowable
675 		 */
676 
677 		if (optlen < sizeof(struct in_addr))
678 			goto e_inval;
679 
680 		err = -EFAULT;
681 		if (optlen >= sizeof(struct ip_mreqn)) {
682 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
683 				break;
684 		} else {
685 			memset(&mreq, 0, sizeof(mreq));
686 			if (optlen >= sizeof(struct ip_mreq)) {
687 				if (copy_from_user(&mreq, optval,
688 						   sizeof(struct ip_mreq)))
689 					break;
690 			} else if (optlen >= sizeof(struct in_addr)) {
691 				if (copy_from_user(&mreq.imr_address, optval,
692 						   sizeof(struct in_addr)))
693 					break;
694 			}
695 		}
696 
697 		if (!mreq.imr_ifindex) {
698 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
699 				inet->mc_index = 0;
700 				inet->mc_addr  = 0;
701 				err = 0;
702 				break;
703 			}
704 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
705 			if (dev)
706 				mreq.imr_ifindex = dev->ifindex;
707 		} else
708 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
709 
710 
711 		err = -EADDRNOTAVAIL;
712 		if (!dev)
713 			break;
714 		dev_put(dev);
715 
716 		err = -EINVAL;
717 		if (sk->sk_bound_dev_if &&
718 		    mreq.imr_ifindex != sk->sk_bound_dev_if)
719 			break;
720 
721 		inet->mc_index = mreq.imr_ifindex;
722 		inet->mc_addr  = mreq.imr_address.s_addr;
723 		err = 0;
724 		break;
725 	}
726 
727 	case IP_ADD_MEMBERSHIP:
728 	case IP_DROP_MEMBERSHIP:
729 	{
730 		struct ip_mreqn mreq;
731 
732 		err = -EPROTO;
733 		if (inet_sk(sk)->is_icsk)
734 			break;
735 
736 		if (optlen < sizeof(struct ip_mreq))
737 			goto e_inval;
738 		err = -EFAULT;
739 		if (optlen >= sizeof(struct ip_mreqn)) {
740 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
741 				break;
742 		} else {
743 			memset(&mreq, 0, sizeof(mreq));
744 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
745 				break;
746 		}
747 
748 		if (optname == IP_ADD_MEMBERSHIP)
749 			err = ip_mc_join_group(sk, &mreq);
750 		else
751 			err = ip_mc_leave_group(sk, &mreq);
752 		break;
753 	}
754 	case IP_MSFILTER:
755 	{
756 		struct ip_msfilter *msf;
757 
758 		if (optlen < IP_MSFILTER_SIZE(0))
759 			goto e_inval;
760 		if (optlen > sysctl_optmem_max) {
761 			err = -ENOBUFS;
762 			break;
763 		}
764 		msf = kmalloc(optlen, GFP_KERNEL);
765 		if (!msf) {
766 			err = -ENOBUFS;
767 			break;
768 		}
769 		err = -EFAULT;
770 		if (copy_from_user(msf, optval, optlen)) {
771 			kfree(msf);
772 			break;
773 		}
774 		/* numsrc >= (1G-4) overflow in 32 bits */
775 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
776 		    msf->imsf_numsrc > sysctl_igmp_max_msf) {
777 			kfree(msf);
778 			err = -ENOBUFS;
779 			break;
780 		}
781 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
782 			kfree(msf);
783 			err = -EINVAL;
784 			break;
785 		}
786 		err = ip_mc_msfilter(sk, msf, 0);
787 		kfree(msf);
788 		break;
789 	}
790 	case IP_BLOCK_SOURCE:
791 	case IP_UNBLOCK_SOURCE:
792 	case IP_ADD_SOURCE_MEMBERSHIP:
793 	case IP_DROP_SOURCE_MEMBERSHIP:
794 	{
795 		struct ip_mreq_source mreqs;
796 		int omode, add;
797 
798 		if (optlen != sizeof(struct ip_mreq_source))
799 			goto e_inval;
800 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
801 			err = -EFAULT;
802 			break;
803 		}
804 		if (optname == IP_BLOCK_SOURCE) {
805 			omode = MCAST_EXCLUDE;
806 			add = 1;
807 		} else if (optname == IP_UNBLOCK_SOURCE) {
808 			omode = MCAST_EXCLUDE;
809 			add = 0;
810 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
811 			struct ip_mreqn mreq;
812 
813 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
814 			mreq.imr_address.s_addr = mreqs.imr_interface;
815 			mreq.imr_ifindex = 0;
816 			err = ip_mc_join_group(sk, &mreq);
817 			if (err && err != -EADDRINUSE)
818 				break;
819 			omode = MCAST_INCLUDE;
820 			add = 1;
821 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
822 			omode = MCAST_INCLUDE;
823 			add = 0;
824 		}
825 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
826 		break;
827 	}
828 	case MCAST_JOIN_GROUP:
829 	case MCAST_LEAVE_GROUP:
830 	{
831 		struct group_req greq;
832 		struct sockaddr_in *psin;
833 		struct ip_mreqn mreq;
834 
835 		if (optlen < sizeof(struct group_req))
836 			goto e_inval;
837 		err = -EFAULT;
838 		if (copy_from_user(&greq, optval, sizeof(greq)))
839 			break;
840 		psin = (struct sockaddr_in *)&greq.gr_group;
841 		if (psin->sin_family != AF_INET)
842 			goto e_inval;
843 		memset(&mreq, 0, sizeof(mreq));
844 		mreq.imr_multiaddr = psin->sin_addr;
845 		mreq.imr_ifindex = greq.gr_interface;
846 
847 		if (optname == MCAST_JOIN_GROUP)
848 			err = ip_mc_join_group(sk, &mreq);
849 		else
850 			err = ip_mc_leave_group(sk, &mreq);
851 		break;
852 	}
853 	case MCAST_JOIN_SOURCE_GROUP:
854 	case MCAST_LEAVE_SOURCE_GROUP:
855 	case MCAST_BLOCK_SOURCE:
856 	case MCAST_UNBLOCK_SOURCE:
857 	{
858 		struct group_source_req greqs;
859 		struct ip_mreq_source mreqs;
860 		struct sockaddr_in *psin;
861 		int omode, add;
862 
863 		if (optlen != sizeof(struct group_source_req))
864 			goto e_inval;
865 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
866 			err = -EFAULT;
867 			break;
868 		}
869 		if (greqs.gsr_group.ss_family != AF_INET ||
870 		    greqs.gsr_source.ss_family != AF_INET) {
871 			err = -EADDRNOTAVAIL;
872 			break;
873 		}
874 		psin = (struct sockaddr_in *)&greqs.gsr_group;
875 		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
876 		psin = (struct sockaddr_in *)&greqs.gsr_source;
877 		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
878 		mreqs.imr_interface = 0; /* use index for mc_source */
879 
880 		if (optname == MCAST_BLOCK_SOURCE) {
881 			omode = MCAST_EXCLUDE;
882 			add = 1;
883 		} else if (optname == MCAST_UNBLOCK_SOURCE) {
884 			omode = MCAST_EXCLUDE;
885 			add = 0;
886 		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
887 			struct ip_mreqn mreq;
888 
889 			psin = (struct sockaddr_in *)&greqs.gsr_group;
890 			mreq.imr_multiaddr = psin->sin_addr;
891 			mreq.imr_address.s_addr = 0;
892 			mreq.imr_ifindex = greqs.gsr_interface;
893 			err = ip_mc_join_group(sk, &mreq);
894 			if (err && err != -EADDRINUSE)
895 				break;
896 			greqs.gsr_interface = mreq.imr_ifindex;
897 			omode = MCAST_INCLUDE;
898 			add = 1;
899 		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
900 			omode = MCAST_INCLUDE;
901 			add = 0;
902 		}
903 		err = ip_mc_source(add, omode, sk, &mreqs,
904 				   greqs.gsr_interface);
905 		break;
906 	}
907 	case MCAST_MSFILTER:
908 	{
909 		struct sockaddr_in *psin;
910 		struct ip_msfilter *msf = NULL;
911 		struct group_filter *gsf = NULL;
912 		int msize, i, ifindex;
913 
914 		if (optlen < GROUP_FILTER_SIZE(0))
915 			goto e_inval;
916 		if (optlen > sysctl_optmem_max) {
917 			err = -ENOBUFS;
918 			break;
919 		}
920 		gsf = kmalloc(optlen, GFP_KERNEL);
921 		if (!gsf) {
922 			err = -ENOBUFS;
923 			break;
924 		}
925 		err = -EFAULT;
926 		if (copy_from_user(gsf, optval, optlen))
927 			goto mc_msf_out;
928 
929 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
930 		if (gsf->gf_numsrc >= 0x1ffffff ||
931 		    gsf->gf_numsrc > sysctl_igmp_max_msf) {
932 			err = -ENOBUFS;
933 			goto mc_msf_out;
934 		}
935 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
936 			err = -EINVAL;
937 			goto mc_msf_out;
938 		}
939 		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
940 		msf = kmalloc(msize, GFP_KERNEL);
941 		if (!msf) {
942 			err = -ENOBUFS;
943 			goto mc_msf_out;
944 		}
945 		ifindex = gsf->gf_interface;
946 		psin = (struct sockaddr_in *)&gsf->gf_group;
947 		if (psin->sin_family != AF_INET) {
948 			err = -EADDRNOTAVAIL;
949 			goto mc_msf_out;
950 		}
951 		msf->imsf_multiaddr = psin->sin_addr.s_addr;
952 		msf->imsf_interface = 0;
953 		msf->imsf_fmode = gsf->gf_fmode;
954 		msf->imsf_numsrc = gsf->gf_numsrc;
955 		err = -EADDRNOTAVAIL;
956 		for (i = 0; i < gsf->gf_numsrc; ++i) {
957 			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
958 
959 			if (psin->sin_family != AF_INET)
960 				goto mc_msf_out;
961 			msf->imsf_slist[i] = psin->sin_addr.s_addr;
962 		}
963 		kfree(gsf);
964 		gsf = NULL;
965 
966 		err = ip_mc_msfilter(sk, msf, ifindex);
967 mc_msf_out:
968 		kfree(msf);
969 		kfree(gsf);
970 		break;
971 	}
972 	case IP_MULTICAST_ALL:
973 		if (optlen < 1)
974 			goto e_inval;
975 		if (val != 0 && val != 1)
976 			goto e_inval;
977 		inet->mc_all = val;
978 		break;
979 	case IP_ROUTER_ALERT:
980 		err = ip_ra_control(sk, val ? 1 : 0, NULL);
981 		break;
982 
983 	case IP_FREEBIND:
984 		if (optlen < 1)
985 			goto e_inval;
986 		inet->freebind = !!val;
987 		break;
988 
989 	case IP_IPSEC_POLICY:
990 	case IP_XFRM_POLICY:
991 		err = -EPERM;
992 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
993 			break;
994 		err = xfrm_user_policy(sk, optname, optval, optlen);
995 		break;
996 
997 	case IP_TRANSPARENT:
998 		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
999 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1000 			err = -EPERM;
1001 			break;
1002 		}
1003 		if (optlen < 1)
1004 			goto e_inval;
1005 		inet->transparent = !!val;
1006 		break;
1007 
1008 	case IP_MINTTL:
1009 		if (optlen < 1)
1010 			goto e_inval;
1011 		if (val < 0 || val > 255)
1012 			goto e_inval;
1013 		inet->min_ttl = val;
1014 		break;
1015 
1016 	default:
1017 		err = -ENOPROTOOPT;
1018 		break;
1019 	}
1020 	release_sock(sk);
1021 	return err;
1022 
1023 e_inval:
1024 	release_sock(sk);
1025 	return -EINVAL;
1026 }
1027 
1028 /**
1029  * ipv4_pktinfo_prepare - transfert some info from rtable to skb
1030  * @sk: socket
1031  * @skb: buffer
1032  *
1033  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1034  * destination in skb->cb[] before dst drop.
1035  * This way, receiver doesnt make cache line misses to read rtable.
1036  */
1037 void ipv4_pktinfo_prepare(struct sk_buff *skb)
1038 {
1039 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1040 
1041 	if (skb_rtable(skb)) {
1042 		pktinfo->ipi_ifindex = inet_iif(skb);
1043 		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1044 	} else {
1045 		pktinfo->ipi_ifindex = 0;
1046 		pktinfo->ipi_spec_dst.s_addr = 0;
1047 	}
1048 	skb_dst_drop(skb);
1049 }
1050 
1051 int ip_setsockopt(struct sock *sk, int level,
1052 		int optname, char __user *optval, unsigned int optlen)
1053 {
1054 	int err;
1055 
1056 	if (level != SOL_IP)
1057 		return -ENOPROTOOPT;
1058 
1059 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1060 #ifdef CONFIG_NETFILTER
1061 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1062 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1063 			optname != IP_IPSEC_POLICY &&
1064 			optname != IP_XFRM_POLICY &&
1065 			!ip_mroute_opt(optname)) {
1066 		lock_sock(sk);
1067 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1068 		release_sock(sk);
1069 	}
1070 #endif
1071 	return err;
1072 }
1073 EXPORT_SYMBOL(ip_setsockopt);
1074 
1075 #ifdef CONFIG_COMPAT
1076 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1077 			 char __user *optval, unsigned int optlen)
1078 {
1079 	int err;
1080 
1081 	if (level != SOL_IP)
1082 		return -ENOPROTOOPT;
1083 
1084 	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1085 		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1086 			ip_setsockopt);
1087 
1088 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1089 #ifdef CONFIG_NETFILTER
1090 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1091 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1092 			optname != IP_IPSEC_POLICY &&
1093 			optname != IP_XFRM_POLICY &&
1094 			!ip_mroute_opt(optname)) {
1095 		lock_sock(sk);
1096 		err = compat_nf_setsockopt(sk, PF_INET, optname,
1097 					   optval, optlen);
1098 		release_sock(sk);
1099 	}
1100 #endif
1101 	return err;
1102 }
1103 EXPORT_SYMBOL(compat_ip_setsockopt);
1104 #endif
1105 
1106 /*
1107  *	Get the options. Note for future reference. The GET of IP options gets
1108  *	the _received_ ones. The set sets the _sent_ ones.
1109  */
1110 
1111 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1112 			    char __user *optval, int __user *optlen, unsigned int flags)
1113 {
1114 	struct inet_sock *inet = inet_sk(sk);
1115 	int val;
1116 	int len;
1117 
1118 	if (level != SOL_IP)
1119 		return -EOPNOTSUPP;
1120 
1121 	if (ip_mroute_opt(optname))
1122 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1123 
1124 	if (get_user(len, optlen))
1125 		return -EFAULT;
1126 	if (len < 0)
1127 		return -EINVAL;
1128 
1129 	lock_sock(sk);
1130 
1131 	switch (optname) {
1132 	case IP_OPTIONS:
1133 	{
1134 		unsigned char optbuf[sizeof(struct ip_options)+40];
1135 		struct ip_options *opt = (struct ip_options *)optbuf;
1136 		struct ip_options_rcu *inet_opt;
1137 
1138 		inet_opt = rcu_dereference_protected(inet->inet_opt,
1139 						     sock_owned_by_user(sk));
1140 		opt->optlen = 0;
1141 		if (inet_opt)
1142 			memcpy(optbuf, &inet_opt->opt,
1143 			       sizeof(struct ip_options) +
1144 			       inet_opt->opt.optlen);
1145 		release_sock(sk);
1146 
1147 		if (opt->optlen == 0)
1148 			return put_user(0, optlen);
1149 
1150 		ip_options_undo(opt);
1151 
1152 		len = min_t(unsigned int, len, opt->optlen);
1153 		if (put_user(len, optlen))
1154 			return -EFAULT;
1155 		if (copy_to_user(optval, opt->__data, len))
1156 			return -EFAULT;
1157 		return 0;
1158 	}
1159 	case IP_PKTINFO:
1160 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1161 		break;
1162 	case IP_RECVTTL:
1163 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1164 		break;
1165 	case IP_RECVTOS:
1166 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1167 		break;
1168 	case IP_RECVOPTS:
1169 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1170 		break;
1171 	case IP_RETOPTS:
1172 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1173 		break;
1174 	case IP_PASSSEC:
1175 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1176 		break;
1177 	case IP_RECVORIGDSTADDR:
1178 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1179 		break;
1180 	case IP_TOS:
1181 		val = inet->tos;
1182 		break;
1183 	case IP_TTL:
1184 		val = (inet->uc_ttl == -1 ?
1185 		       sysctl_ip_default_ttl :
1186 		       inet->uc_ttl);
1187 		break;
1188 	case IP_HDRINCL:
1189 		val = inet->hdrincl;
1190 		break;
1191 	case IP_NODEFRAG:
1192 		val = inet->nodefrag;
1193 		break;
1194 	case IP_MTU_DISCOVER:
1195 		val = inet->pmtudisc;
1196 		break;
1197 	case IP_MTU:
1198 	{
1199 		struct dst_entry *dst;
1200 		val = 0;
1201 		dst = sk_dst_get(sk);
1202 		if (dst) {
1203 			val = dst_mtu(dst);
1204 			dst_release(dst);
1205 		}
1206 		if (!val) {
1207 			release_sock(sk);
1208 			return -ENOTCONN;
1209 		}
1210 		break;
1211 	}
1212 	case IP_RECVERR:
1213 		val = inet->recverr;
1214 		break;
1215 	case IP_MULTICAST_TTL:
1216 		val = inet->mc_ttl;
1217 		break;
1218 	case IP_MULTICAST_LOOP:
1219 		val = inet->mc_loop;
1220 		break;
1221 	case IP_UNICAST_IF:
1222 		val = (__force int)htonl((__u32) inet->uc_index);
1223 		break;
1224 	case IP_MULTICAST_IF:
1225 	{
1226 		struct in_addr addr;
1227 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1228 		addr.s_addr = inet->mc_addr;
1229 		release_sock(sk);
1230 
1231 		if (put_user(len, optlen))
1232 			return -EFAULT;
1233 		if (copy_to_user(optval, &addr, len))
1234 			return -EFAULT;
1235 		return 0;
1236 	}
1237 	case IP_MSFILTER:
1238 	{
1239 		struct ip_msfilter msf;
1240 		int err;
1241 
1242 		if (len < IP_MSFILTER_SIZE(0)) {
1243 			release_sock(sk);
1244 			return -EINVAL;
1245 		}
1246 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1247 			release_sock(sk);
1248 			return -EFAULT;
1249 		}
1250 		err = ip_mc_msfget(sk, &msf,
1251 				   (struct ip_msfilter __user *)optval, optlen);
1252 		release_sock(sk);
1253 		return err;
1254 	}
1255 	case MCAST_MSFILTER:
1256 	{
1257 		struct group_filter gsf;
1258 		int err;
1259 
1260 		if (len < GROUP_FILTER_SIZE(0)) {
1261 			release_sock(sk);
1262 			return -EINVAL;
1263 		}
1264 		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1265 			release_sock(sk);
1266 			return -EFAULT;
1267 		}
1268 		err = ip_mc_gsfget(sk, &gsf,
1269 				   (struct group_filter __user *)optval,
1270 				   optlen);
1271 		release_sock(sk);
1272 		return err;
1273 	}
1274 	case IP_MULTICAST_ALL:
1275 		val = inet->mc_all;
1276 		break;
1277 	case IP_PKTOPTIONS:
1278 	{
1279 		struct msghdr msg;
1280 
1281 		release_sock(sk);
1282 
1283 		if (sk->sk_type != SOCK_STREAM)
1284 			return -ENOPROTOOPT;
1285 
1286 		msg.msg_control = optval;
1287 		msg.msg_controllen = len;
1288 		msg.msg_flags = flags;
1289 
1290 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1291 			struct in_pktinfo info;
1292 
1293 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1294 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1295 			info.ipi_ifindex = inet->mc_index;
1296 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1297 		}
1298 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1299 			int hlim = inet->mc_ttl;
1300 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1301 		}
1302 		if (inet->cmsg_flags & IP_CMSG_TOS) {
1303 			int tos = inet->rcv_tos;
1304 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1305 		}
1306 		len -= msg.msg_controllen;
1307 		return put_user(len, optlen);
1308 	}
1309 	case IP_FREEBIND:
1310 		val = inet->freebind;
1311 		break;
1312 	case IP_TRANSPARENT:
1313 		val = inet->transparent;
1314 		break;
1315 	case IP_MINTTL:
1316 		val = inet->min_ttl;
1317 		break;
1318 	default:
1319 		release_sock(sk);
1320 		return -ENOPROTOOPT;
1321 	}
1322 	release_sock(sk);
1323 
1324 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1325 		unsigned char ucval = (unsigned char)val;
1326 		len = 1;
1327 		if (put_user(len, optlen))
1328 			return -EFAULT;
1329 		if (copy_to_user(optval, &ucval, 1))
1330 			return -EFAULT;
1331 	} else {
1332 		len = min_t(unsigned int, sizeof(int), len);
1333 		if (put_user(len, optlen))
1334 			return -EFAULT;
1335 		if (copy_to_user(optval, &val, len))
1336 			return -EFAULT;
1337 	}
1338 	return 0;
1339 }
1340 
1341 int ip_getsockopt(struct sock *sk, int level,
1342 		  int optname, char __user *optval, int __user *optlen)
1343 {
1344 	int err;
1345 
1346 	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1347 #ifdef CONFIG_NETFILTER
1348 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1349 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1350 			!ip_mroute_opt(optname)) {
1351 		int len;
1352 
1353 		if (get_user(len, optlen))
1354 			return -EFAULT;
1355 
1356 		lock_sock(sk);
1357 		err = nf_getsockopt(sk, PF_INET, optname, optval,
1358 				&len);
1359 		release_sock(sk);
1360 		if (err >= 0)
1361 			err = put_user(len, optlen);
1362 		return err;
1363 	}
1364 #endif
1365 	return err;
1366 }
1367 EXPORT_SYMBOL(ip_getsockopt);
1368 
1369 #ifdef CONFIG_COMPAT
1370 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1371 			 char __user *optval, int __user *optlen)
1372 {
1373 	int err;
1374 
1375 	if (optname == MCAST_MSFILTER)
1376 		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1377 			ip_getsockopt);
1378 
1379 	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1380 		MSG_CMSG_COMPAT);
1381 
1382 #ifdef CONFIG_NETFILTER
1383 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1384 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1385 			!ip_mroute_opt(optname)) {
1386 		int len;
1387 
1388 		if (get_user(len, optlen))
1389 			return -EFAULT;
1390 
1391 		lock_sock(sk);
1392 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1393 		release_sock(sk);
1394 		if (err >= 0)
1395 			err = put_user(len, optlen);
1396 		return err;
1397 	}
1398 #endif
1399 	return err;
1400 }
1401 EXPORT_SYMBOL(compat_ip_getsockopt);
1402 #endif
1403