xref: /linux/net/ipv4/ip_sockglue.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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 
44 #include <linux/errqueue.h>
45 #include <asm/uaccess.h>
46 
47 #define IP_CMSG_PKTINFO		1
48 #define IP_CMSG_TTL		2
49 #define IP_CMSG_TOS		4
50 #define IP_CMSG_RECVOPTS	8
51 #define IP_CMSG_RETOPTS		16
52 #define IP_CMSG_PASSSEC		32
53 #define IP_CMSG_ORIGDSTADDR     64
54 
55 /*
56  *	SOL_IP control messages.
57  */
58 #define PKTINFO_SKB_CB(__skb) ((struct in_pktinfo *)((__skb)->cb))
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 {
191 	int err;
192 	struct cmsghdr *cmsg;
193 
194 	for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
195 		if (!CMSG_OK(msg, cmsg))
196 			return -EINVAL;
197 		if (cmsg->cmsg_level != SOL_IP)
198 			continue;
199 		switch (cmsg->cmsg_type) {
200 		case IP_RETOPTS:
201 			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
202 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
203 					     err < 40 ? err : 40);
204 			if (err)
205 				return err;
206 			break;
207 		case IP_PKTINFO:
208 		{
209 			struct in_pktinfo *info;
210 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
211 				return -EINVAL;
212 			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
213 			ipc->oif = info->ipi_ifindex;
214 			ipc->addr = info->ipi_spec_dst.s_addr;
215 			break;
216 		}
217 		default:
218 			return -EINVAL;
219 		}
220 	}
221 	return 0;
222 }
223 
224 
225 /* Special input handler for packets caught by router alert option.
226    They are selected only by protocol field, and then processed likely
227    local ones; but only if someone wants them! Otherwise, router
228    not running rsvpd will kill RSVP.
229 
230    It is user level problem, what it will make with them.
231    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
232    but receiver should be enough clever f.e. to forward mtrace requests,
233    sent to multicast group to reach destination designated router.
234  */
235 struct ip_ra_chain __rcu *ip_ra_chain;
236 static DEFINE_SPINLOCK(ip_ra_lock);
237 
238 
239 static void ip_ra_destroy_rcu(struct rcu_head *head)
240 {
241 	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
242 
243 	sock_put(ra->saved_sk);
244 	kfree(ra);
245 }
246 
247 int ip_ra_control(struct sock *sk, unsigned char on,
248 		  void (*destructor)(struct sock *))
249 {
250 	struct ip_ra_chain *ra, *new_ra;
251 	struct ip_ra_chain __rcu **rap;
252 
253 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
254 		return -EINVAL;
255 
256 	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
257 
258 	spin_lock_bh(&ip_ra_lock);
259 	for (rap = &ip_ra_chain;
260 	     (ra = rcu_dereference_protected(*rap,
261 			lockdep_is_held(&ip_ra_lock))) != NULL;
262 	     rap = &ra->next) {
263 		if (ra->sk == sk) {
264 			if (on) {
265 				spin_unlock_bh(&ip_ra_lock);
266 				kfree(new_ra);
267 				return -EADDRINUSE;
268 			}
269 			/* dont let ip_call_ra_chain() use sk again */
270 			ra->sk = NULL;
271 			rcu_assign_pointer(*rap, ra->next);
272 			spin_unlock_bh(&ip_ra_lock);
273 
274 			if (ra->destructor)
275 				ra->destructor(sk);
276 			/*
277 			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
278 			 * period. This guarantee ip_call_ra_chain() dont need
279 			 * to mess with socket refcounts.
280 			 */
281 			ra->saved_sk = sk;
282 			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
283 			return 0;
284 		}
285 	}
286 	if (new_ra == NULL) {
287 		spin_unlock_bh(&ip_ra_lock);
288 		return -ENOBUFS;
289 	}
290 	new_ra->sk = sk;
291 	new_ra->destructor = destructor;
292 
293 	new_ra->next = ra;
294 	rcu_assign_pointer(*rap, new_ra);
295 	sock_hold(sk);
296 	spin_unlock_bh(&ip_ra_lock);
297 
298 	return 0;
299 }
300 
301 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
302 		   __be16 port, u32 info, u8 *payload)
303 {
304 	struct sock_exterr_skb *serr;
305 
306 	skb = skb_clone(skb, GFP_ATOMIC);
307 	if (!skb)
308 		return;
309 
310 	serr = SKB_EXT_ERR(skb);
311 	serr->ee.ee_errno = err;
312 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
313 	serr->ee.ee_type = icmp_hdr(skb)->type;
314 	serr->ee.ee_code = icmp_hdr(skb)->code;
315 	serr->ee.ee_pad = 0;
316 	serr->ee.ee_info = info;
317 	serr->ee.ee_data = 0;
318 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
319 				   skb_network_header(skb);
320 	serr->port = port;
321 
322 	if (skb_pull(skb, payload - skb->data) != NULL) {
323 		skb_reset_transport_header(skb);
324 		if (sock_queue_err_skb(sk, skb) == 0)
325 			return;
326 	}
327 	kfree_skb(skb);
328 }
329 
330 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
331 {
332 	struct inet_sock *inet = inet_sk(sk);
333 	struct sock_exterr_skb *serr;
334 	struct iphdr *iph;
335 	struct sk_buff *skb;
336 
337 	if (!inet->recverr)
338 		return;
339 
340 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
341 	if (!skb)
342 		return;
343 
344 	skb_put(skb, sizeof(struct iphdr));
345 	skb_reset_network_header(skb);
346 	iph = ip_hdr(skb);
347 	iph->daddr = daddr;
348 
349 	serr = SKB_EXT_ERR(skb);
350 	serr->ee.ee_errno = err;
351 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
352 	serr->ee.ee_type = 0;
353 	serr->ee.ee_code = 0;
354 	serr->ee.ee_pad = 0;
355 	serr->ee.ee_info = info;
356 	serr->ee.ee_data = 0;
357 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
358 	serr->port = port;
359 
360 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
361 	skb_reset_transport_header(skb);
362 
363 	if (sock_queue_err_skb(sk, skb))
364 		kfree_skb(skb);
365 }
366 
367 /*
368  *	Handle MSG_ERRQUEUE
369  */
370 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len)
371 {
372 	struct sock_exterr_skb *serr;
373 	struct sk_buff *skb, *skb2;
374 	struct sockaddr_in *sin;
375 	struct {
376 		struct sock_extended_err ee;
377 		struct sockaddr_in	 offender;
378 	} errhdr;
379 	int err;
380 	int copied;
381 
382 	err = -EAGAIN;
383 	skb = skb_dequeue(&sk->sk_error_queue);
384 	if (skb == NULL)
385 		goto out;
386 
387 	copied = skb->len;
388 	if (copied > len) {
389 		msg->msg_flags |= MSG_TRUNC;
390 		copied = len;
391 	}
392 	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
393 	if (err)
394 		goto out_free_skb;
395 
396 	sock_recv_timestamp(msg, sk, skb);
397 
398 	serr = SKB_EXT_ERR(skb);
399 
400 	sin = (struct sockaddr_in *)msg->msg_name;
401 	if (sin) {
402 		sin->sin_family = AF_INET;
403 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
404 						   serr->addr_offset);
405 		sin->sin_port = serr->port;
406 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
407 	}
408 
409 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
410 	sin = &errhdr.offender;
411 	sin->sin_family = AF_UNSPEC;
412 	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP) {
413 		struct inet_sock *inet = inet_sk(sk);
414 
415 		sin->sin_family = AF_INET;
416 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
417 		sin->sin_port = 0;
418 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
419 		if (inet->cmsg_flags)
420 			ip_cmsg_recv(msg, skb);
421 	}
422 
423 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
424 
425 	/* Now we could try to dump offended packet options */
426 
427 	msg->msg_flags |= MSG_ERRQUEUE;
428 	err = copied;
429 
430 	/* Reset and regenerate socket error */
431 	spin_lock_bh(&sk->sk_error_queue.lock);
432 	sk->sk_err = 0;
433 	skb2 = skb_peek(&sk->sk_error_queue);
434 	if (skb2 != NULL) {
435 		sk->sk_err = SKB_EXT_ERR(skb2)->ee.ee_errno;
436 		spin_unlock_bh(&sk->sk_error_queue.lock);
437 		sk->sk_error_report(sk);
438 	} else
439 		spin_unlock_bh(&sk->sk_error_queue.lock);
440 
441 out_free_skb:
442 	kfree_skb(skb);
443 out:
444 	return err;
445 }
446 
447 
448 /*
449  *	Socket option code for IP. This is the end of the line after any
450  *	TCP,UDP etc options on an IP socket.
451  */
452 
453 static int do_ip_setsockopt(struct sock *sk, int level,
454 			    int optname, char __user *optval, unsigned int optlen)
455 {
456 	struct inet_sock *inet = inet_sk(sk);
457 	int val = 0, err;
458 
459 	if (((1<<optname) & ((1<<IP_PKTINFO) | (1<<IP_RECVTTL) |
460 			     (1<<IP_RECVOPTS) | (1<<IP_RECVTOS) |
461 			     (1<<IP_RETOPTS) | (1<<IP_TOS) |
462 			     (1<<IP_TTL) | (1<<IP_HDRINCL) |
463 			     (1<<IP_MTU_DISCOVER) | (1<<IP_RECVERR) |
464 			     (1<<IP_ROUTER_ALERT) | (1<<IP_FREEBIND) |
465 			     (1<<IP_PASSSEC) | (1<<IP_TRANSPARENT) |
466 			     (1<<IP_MINTTL) | (1<<IP_NODEFRAG))) ||
467 	    optname == IP_UNICAST_IF ||
468 	    optname == IP_MULTICAST_TTL ||
469 	    optname == IP_MULTICAST_ALL ||
470 	    optname == IP_MULTICAST_LOOP ||
471 	    optname == IP_RECVORIGDSTADDR) {
472 		if (optlen >= sizeof(int)) {
473 			if (get_user(val, (int __user *) optval))
474 				return -EFAULT;
475 		} else if (optlen >= sizeof(char)) {
476 			unsigned char ucval;
477 
478 			if (get_user(ucval, (unsigned char __user *) optval))
479 				return -EFAULT;
480 			val = (int) ucval;
481 		}
482 	}
483 
484 	/* If optlen==0, it is equivalent to val == 0 */
485 
486 	if (ip_mroute_opt(optname))
487 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
488 
489 	err = 0;
490 	lock_sock(sk);
491 
492 	switch (optname) {
493 	case IP_OPTIONS:
494 	{
495 		struct ip_options_rcu *old, *opt = NULL;
496 
497 		if (optlen > 40)
498 			goto e_inval;
499 		err = ip_options_get_from_user(sock_net(sk), &opt,
500 					       optval, optlen);
501 		if (err)
502 			break;
503 		old = rcu_dereference_protected(inet->inet_opt,
504 						sock_owned_by_user(sk));
505 		if (inet->is_icsk) {
506 			struct inet_connection_sock *icsk = inet_csk(sk);
507 #if IS_ENABLED(CONFIG_IPV6)
508 			if (sk->sk_family == PF_INET ||
509 			    (!((1 << sk->sk_state) &
510 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
511 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
512 #endif
513 				if (old)
514 					icsk->icsk_ext_hdr_len -= old->opt.optlen;
515 				if (opt)
516 					icsk->icsk_ext_hdr_len += opt->opt.optlen;
517 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
518 #if IS_ENABLED(CONFIG_IPV6)
519 			}
520 #endif
521 		}
522 		rcu_assign_pointer(inet->inet_opt, opt);
523 		if (old)
524 			kfree_rcu(old, rcu);
525 		break;
526 	}
527 	case IP_PKTINFO:
528 		if (val)
529 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
530 		else
531 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
532 		break;
533 	case IP_RECVTTL:
534 		if (val)
535 			inet->cmsg_flags |=  IP_CMSG_TTL;
536 		else
537 			inet->cmsg_flags &= ~IP_CMSG_TTL;
538 		break;
539 	case IP_RECVTOS:
540 		if (val)
541 			inet->cmsg_flags |=  IP_CMSG_TOS;
542 		else
543 			inet->cmsg_flags &= ~IP_CMSG_TOS;
544 		break;
545 	case IP_RECVOPTS:
546 		if (val)
547 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
548 		else
549 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
550 		break;
551 	case IP_RETOPTS:
552 		if (val)
553 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
554 		else
555 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
556 		break;
557 	case IP_PASSSEC:
558 		if (val)
559 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
560 		else
561 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
562 		break;
563 	case IP_RECVORIGDSTADDR:
564 		if (val)
565 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
566 		else
567 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
568 		break;
569 	case IP_TOS:	/* This sets both TOS and Precedence */
570 		if (sk->sk_type == SOCK_STREAM) {
571 			val &= ~INET_ECN_MASK;
572 			val |= inet->tos & INET_ECN_MASK;
573 		}
574 		if (inet->tos != val) {
575 			inet->tos = val;
576 			sk->sk_priority = rt_tos2priority(val);
577 			sk_dst_reset(sk);
578 		}
579 		break;
580 	case IP_TTL:
581 		if (optlen < 1)
582 			goto e_inval;
583 		if (val != -1 && (val < 0 || val > 255))
584 			goto e_inval;
585 		inet->uc_ttl = val;
586 		break;
587 	case IP_HDRINCL:
588 		if (sk->sk_type != SOCK_RAW) {
589 			err = -ENOPROTOOPT;
590 			break;
591 		}
592 		inet->hdrincl = val ? 1 : 0;
593 		break;
594 	case IP_NODEFRAG:
595 		if (sk->sk_type != SOCK_RAW) {
596 			err = -ENOPROTOOPT;
597 			break;
598 		}
599 		inet->nodefrag = val ? 1 : 0;
600 		break;
601 	case IP_MTU_DISCOVER:
602 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_PROBE)
603 			goto e_inval;
604 		inet->pmtudisc = val;
605 		break;
606 	case IP_RECVERR:
607 		inet->recverr = !!val;
608 		if (!val)
609 			skb_queue_purge(&sk->sk_error_queue);
610 		break;
611 	case IP_MULTICAST_TTL:
612 		if (sk->sk_type == SOCK_STREAM)
613 			goto e_inval;
614 		if (optlen < 1)
615 			goto e_inval;
616 		if (val == -1)
617 			val = 1;
618 		if (val < 0 || val > 255)
619 			goto e_inval;
620 		inet->mc_ttl = val;
621 		break;
622 	case IP_MULTICAST_LOOP:
623 		if (optlen < 1)
624 			goto e_inval;
625 		inet->mc_loop = !!val;
626 		break;
627 	case IP_UNICAST_IF:
628 	{
629 		struct net_device *dev = NULL;
630 		int ifindex;
631 
632 		if (optlen != sizeof(int))
633 			goto e_inval;
634 
635 		ifindex = (__force int)ntohl((__force __be32)val);
636 		if (ifindex == 0) {
637 			inet->uc_index = 0;
638 			err = 0;
639 			break;
640 		}
641 
642 		dev = dev_get_by_index(sock_net(sk), ifindex);
643 		err = -EADDRNOTAVAIL;
644 		if (!dev)
645 			break;
646 		dev_put(dev);
647 
648 		err = -EINVAL;
649 		if (sk->sk_bound_dev_if)
650 			break;
651 
652 		inet->uc_index = ifindex;
653 		err = 0;
654 		break;
655 	}
656 	case IP_MULTICAST_IF:
657 	{
658 		struct ip_mreqn mreq;
659 		struct net_device *dev = NULL;
660 
661 		if (sk->sk_type == SOCK_STREAM)
662 			goto e_inval;
663 		/*
664 		 *	Check the arguments are allowable
665 		 */
666 
667 		if (optlen < sizeof(struct in_addr))
668 			goto e_inval;
669 
670 		err = -EFAULT;
671 		if (optlen >= sizeof(struct ip_mreqn)) {
672 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
673 				break;
674 		} else {
675 			memset(&mreq, 0, sizeof(mreq));
676 			if (optlen >= sizeof(struct ip_mreq)) {
677 				if (copy_from_user(&mreq, optval,
678 						   sizeof(struct ip_mreq)))
679 					break;
680 			} else if (optlen >= sizeof(struct in_addr)) {
681 				if (copy_from_user(&mreq.imr_address, optval,
682 						   sizeof(struct in_addr)))
683 					break;
684 			}
685 		}
686 
687 		if (!mreq.imr_ifindex) {
688 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
689 				inet->mc_index = 0;
690 				inet->mc_addr  = 0;
691 				err = 0;
692 				break;
693 			}
694 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
695 			if (dev)
696 				mreq.imr_ifindex = dev->ifindex;
697 		} else
698 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
699 
700 
701 		err = -EADDRNOTAVAIL;
702 		if (!dev)
703 			break;
704 		dev_put(dev);
705 
706 		err = -EINVAL;
707 		if (sk->sk_bound_dev_if &&
708 		    mreq.imr_ifindex != sk->sk_bound_dev_if)
709 			break;
710 
711 		inet->mc_index = mreq.imr_ifindex;
712 		inet->mc_addr  = mreq.imr_address.s_addr;
713 		err = 0;
714 		break;
715 	}
716 
717 	case IP_ADD_MEMBERSHIP:
718 	case IP_DROP_MEMBERSHIP:
719 	{
720 		struct ip_mreqn mreq;
721 
722 		err = -EPROTO;
723 		if (inet_sk(sk)->is_icsk)
724 			break;
725 
726 		if (optlen < sizeof(struct ip_mreq))
727 			goto e_inval;
728 		err = -EFAULT;
729 		if (optlen >= sizeof(struct ip_mreqn)) {
730 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
731 				break;
732 		} else {
733 			memset(&mreq, 0, sizeof(mreq));
734 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
735 				break;
736 		}
737 
738 		if (optname == IP_ADD_MEMBERSHIP)
739 			err = ip_mc_join_group(sk, &mreq);
740 		else
741 			err = ip_mc_leave_group(sk, &mreq);
742 		break;
743 	}
744 	case IP_MSFILTER:
745 	{
746 		struct ip_msfilter *msf;
747 
748 		if (optlen < IP_MSFILTER_SIZE(0))
749 			goto e_inval;
750 		if (optlen > sysctl_optmem_max) {
751 			err = -ENOBUFS;
752 			break;
753 		}
754 		msf = kmalloc(optlen, GFP_KERNEL);
755 		if (!msf) {
756 			err = -ENOBUFS;
757 			break;
758 		}
759 		err = -EFAULT;
760 		if (copy_from_user(msf, optval, optlen)) {
761 			kfree(msf);
762 			break;
763 		}
764 		/* numsrc >= (1G-4) overflow in 32 bits */
765 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
766 		    msf->imsf_numsrc > sysctl_igmp_max_msf) {
767 			kfree(msf);
768 			err = -ENOBUFS;
769 			break;
770 		}
771 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
772 			kfree(msf);
773 			err = -EINVAL;
774 			break;
775 		}
776 		err = ip_mc_msfilter(sk, msf, 0);
777 		kfree(msf);
778 		break;
779 	}
780 	case IP_BLOCK_SOURCE:
781 	case IP_UNBLOCK_SOURCE:
782 	case IP_ADD_SOURCE_MEMBERSHIP:
783 	case IP_DROP_SOURCE_MEMBERSHIP:
784 	{
785 		struct ip_mreq_source mreqs;
786 		int omode, add;
787 
788 		if (optlen != sizeof(struct ip_mreq_source))
789 			goto e_inval;
790 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
791 			err = -EFAULT;
792 			break;
793 		}
794 		if (optname == IP_BLOCK_SOURCE) {
795 			omode = MCAST_EXCLUDE;
796 			add = 1;
797 		} else if (optname == IP_UNBLOCK_SOURCE) {
798 			omode = MCAST_EXCLUDE;
799 			add = 0;
800 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
801 			struct ip_mreqn mreq;
802 
803 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
804 			mreq.imr_address.s_addr = mreqs.imr_interface;
805 			mreq.imr_ifindex = 0;
806 			err = ip_mc_join_group(sk, &mreq);
807 			if (err && err != -EADDRINUSE)
808 				break;
809 			omode = MCAST_INCLUDE;
810 			add = 1;
811 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
812 			omode = MCAST_INCLUDE;
813 			add = 0;
814 		}
815 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
816 		break;
817 	}
818 	case MCAST_JOIN_GROUP:
819 	case MCAST_LEAVE_GROUP:
820 	{
821 		struct group_req greq;
822 		struct sockaddr_in *psin;
823 		struct ip_mreqn mreq;
824 
825 		if (optlen < sizeof(struct group_req))
826 			goto e_inval;
827 		err = -EFAULT;
828 		if (copy_from_user(&greq, optval, sizeof(greq)))
829 			break;
830 		psin = (struct sockaddr_in *)&greq.gr_group;
831 		if (psin->sin_family != AF_INET)
832 			goto e_inval;
833 		memset(&mreq, 0, sizeof(mreq));
834 		mreq.imr_multiaddr = psin->sin_addr;
835 		mreq.imr_ifindex = greq.gr_interface;
836 
837 		if (optname == MCAST_JOIN_GROUP)
838 			err = ip_mc_join_group(sk, &mreq);
839 		else
840 			err = ip_mc_leave_group(sk, &mreq);
841 		break;
842 	}
843 	case MCAST_JOIN_SOURCE_GROUP:
844 	case MCAST_LEAVE_SOURCE_GROUP:
845 	case MCAST_BLOCK_SOURCE:
846 	case MCAST_UNBLOCK_SOURCE:
847 	{
848 		struct group_source_req greqs;
849 		struct ip_mreq_source mreqs;
850 		struct sockaddr_in *psin;
851 		int omode, add;
852 
853 		if (optlen != sizeof(struct group_source_req))
854 			goto e_inval;
855 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
856 			err = -EFAULT;
857 			break;
858 		}
859 		if (greqs.gsr_group.ss_family != AF_INET ||
860 		    greqs.gsr_source.ss_family != AF_INET) {
861 			err = -EADDRNOTAVAIL;
862 			break;
863 		}
864 		psin = (struct sockaddr_in *)&greqs.gsr_group;
865 		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
866 		psin = (struct sockaddr_in *)&greqs.gsr_source;
867 		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
868 		mreqs.imr_interface = 0; /* use index for mc_source */
869 
870 		if (optname == MCAST_BLOCK_SOURCE) {
871 			omode = MCAST_EXCLUDE;
872 			add = 1;
873 		} else if (optname == MCAST_UNBLOCK_SOURCE) {
874 			omode = MCAST_EXCLUDE;
875 			add = 0;
876 		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
877 			struct ip_mreqn mreq;
878 
879 			psin = (struct sockaddr_in *)&greqs.gsr_group;
880 			mreq.imr_multiaddr = psin->sin_addr;
881 			mreq.imr_address.s_addr = 0;
882 			mreq.imr_ifindex = greqs.gsr_interface;
883 			err = ip_mc_join_group(sk, &mreq);
884 			if (err && err != -EADDRINUSE)
885 				break;
886 			greqs.gsr_interface = mreq.imr_ifindex;
887 			omode = MCAST_INCLUDE;
888 			add = 1;
889 		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
890 			omode = MCAST_INCLUDE;
891 			add = 0;
892 		}
893 		err = ip_mc_source(add, omode, sk, &mreqs,
894 				   greqs.gsr_interface);
895 		break;
896 	}
897 	case MCAST_MSFILTER:
898 	{
899 		struct sockaddr_in *psin;
900 		struct ip_msfilter *msf = NULL;
901 		struct group_filter *gsf = NULL;
902 		int msize, i, ifindex;
903 
904 		if (optlen < GROUP_FILTER_SIZE(0))
905 			goto e_inval;
906 		if (optlen > sysctl_optmem_max) {
907 			err = -ENOBUFS;
908 			break;
909 		}
910 		gsf = kmalloc(optlen, GFP_KERNEL);
911 		if (!gsf) {
912 			err = -ENOBUFS;
913 			break;
914 		}
915 		err = -EFAULT;
916 		if (copy_from_user(gsf, optval, optlen))
917 			goto mc_msf_out;
918 
919 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
920 		if (gsf->gf_numsrc >= 0x1ffffff ||
921 		    gsf->gf_numsrc > sysctl_igmp_max_msf) {
922 			err = -ENOBUFS;
923 			goto mc_msf_out;
924 		}
925 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
926 			err = -EINVAL;
927 			goto mc_msf_out;
928 		}
929 		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
930 		msf = kmalloc(msize, GFP_KERNEL);
931 		if (!msf) {
932 			err = -ENOBUFS;
933 			goto mc_msf_out;
934 		}
935 		ifindex = gsf->gf_interface;
936 		psin = (struct sockaddr_in *)&gsf->gf_group;
937 		if (psin->sin_family != AF_INET) {
938 			err = -EADDRNOTAVAIL;
939 			goto mc_msf_out;
940 		}
941 		msf->imsf_multiaddr = psin->sin_addr.s_addr;
942 		msf->imsf_interface = 0;
943 		msf->imsf_fmode = gsf->gf_fmode;
944 		msf->imsf_numsrc = gsf->gf_numsrc;
945 		err = -EADDRNOTAVAIL;
946 		for (i = 0; i < gsf->gf_numsrc; ++i) {
947 			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
948 
949 			if (psin->sin_family != AF_INET)
950 				goto mc_msf_out;
951 			msf->imsf_slist[i] = psin->sin_addr.s_addr;
952 		}
953 		kfree(gsf);
954 		gsf = NULL;
955 
956 		err = ip_mc_msfilter(sk, msf, ifindex);
957 mc_msf_out:
958 		kfree(msf);
959 		kfree(gsf);
960 		break;
961 	}
962 	case IP_MULTICAST_ALL:
963 		if (optlen < 1)
964 			goto e_inval;
965 		if (val != 0 && val != 1)
966 			goto e_inval;
967 		inet->mc_all = val;
968 		break;
969 	case IP_ROUTER_ALERT:
970 		err = ip_ra_control(sk, val ? 1 : 0, NULL);
971 		break;
972 
973 	case IP_FREEBIND:
974 		if (optlen < 1)
975 			goto e_inval;
976 		inet->freebind = !!val;
977 		break;
978 
979 	case IP_IPSEC_POLICY:
980 	case IP_XFRM_POLICY:
981 		err = -EPERM;
982 		if (!capable(CAP_NET_ADMIN))
983 			break;
984 		err = xfrm_user_policy(sk, optname, optval, optlen);
985 		break;
986 
987 	case IP_TRANSPARENT:
988 		if (!!val && !capable(CAP_NET_RAW) && !capable(CAP_NET_ADMIN)) {
989 			err = -EPERM;
990 			break;
991 		}
992 		if (optlen < 1)
993 			goto e_inval;
994 		inet->transparent = !!val;
995 		break;
996 
997 	case IP_MINTTL:
998 		if (optlen < 1)
999 			goto e_inval;
1000 		if (val < 0 || val > 255)
1001 			goto e_inval;
1002 		inet->min_ttl = val;
1003 		break;
1004 
1005 	default:
1006 		err = -ENOPROTOOPT;
1007 		break;
1008 	}
1009 	release_sock(sk);
1010 	return err;
1011 
1012 e_inval:
1013 	release_sock(sk);
1014 	return -EINVAL;
1015 }
1016 
1017 /**
1018  * ipv4_pktinfo_prepare - transfert some info from rtable to skb
1019  * @sk: socket
1020  * @skb: buffer
1021  *
1022  * To support IP_CMSG_PKTINFO option, we store rt_iif and rt_spec_dst
1023  * in skb->cb[] before dst drop.
1024  * This way, receiver doesnt make cache line misses to read rtable.
1025  */
1026 void ipv4_pktinfo_prepare(struct sk_buff *skb)
1027 {
1028 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1029 	const struct rtable *rt = skb_rtable(skb);
1030 
1031 	if (rt) {
1032 		pktinfo->ipi_ifindex = rt->rt_iif;
1033 		pktinfo->ipi_spec_dst.s_addr = rt->rt_spec_dst;
1034 	} else {
1035 		pktinfo->ipi_ifindex = 0;
1036 		pktinfo->ipi_spec_dst.s_addr = 0;
1037 	}
1038 	skb_dst_drop(skb);
1039 }
1040 
1041 int ip_setsockopt(struct sock *sk, int level,
1042 		int optname, char __user *optval, unsigned int optlen)
1043 {
1044 	int err;
1045 
1046 	if (level != SOL_IP)
1047 		return -ENOPROTOOPT;
1048 
1049 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1050 #ifdef CONFIG_NETFILTER
1051 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1052 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1053 			optname != IP_IPSEC_POLICY &&
1054 			optname != IP_XFRM_POLICY &&
1055 			!ip_mroute_opt(optname)) {
1056 		lock_sock(sk);
1057 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1058 		release_sock(sk);
1059 	}
1060 #endif
1061 	return err;
1062 }
1063 EXPORT_SYMBOL(ip_setsockopt);
1064 
1065 #ifdef CONFIG_COMPAT
1066 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1067 			 char __user *optval, unsigned int optlen)
1068 {
1069 	int err;
1070 
1071 	if (level != SOL_IP)
1072 		return -ENOPROTOOPT;
1073 
1074 	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1075 		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1076 			ip_setsockopt);
1077 
1078 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1079 #ifdef CONFIG_NETFILTER
1080 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1081 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1082 			optname != IP_IPSEC_POLICY &&
1083 			optname != IP_XFRM_POLICY &&
1084 			!ip_mroute_opt(optname)) {
1085 		lock_sock(sk);
1086 		err = compat_nf_setsockopt(sk, PF_INET, optname,
1087 					   optval, optlen);
1088 		release_sock(sk);
1089 	}
1090 #endif
1091 	return err;
1092 }
1093 EXPORT_SYMBOL(compat_ip_setsockopt);
1094 #endif
1095 
1096 /*
1097  *	Get the options. Note for future reference. The GET of IP options gets
1098  *	the _received_ ones. The set sets the _sent_ ones.
1099  */
1100 
1101 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1102 			    char __user *optval, int __user *optlen, unsigned int flags)
1103 {
1104 	struct inet_sock *inet = inet_sk(sk);
1105 	int val;
1106 	int len;
1107 
1108 	if (level != SOL_IP)
1109 		return -EOPNOTSUPP;
1110 
1111 	if (ip_mroute_opt(optname))
1112 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1113 
1114 	if (get_user(len, optlen))
1115 		return -EFAULT;
1116 	if (len < 0)
1117 		return -EINVAL;
1118 
1119 	lock_sock(sk);
1120 
1121 	switch (optname) {
1122 	case IP_OPTIONS:
1123 	{
1124 		unsigned char optbuf[sizeof(struct ip_options)+40];
1125 		struct ip_options *opt = (struct ip_options *)optbuf;
1126 		struct ip_options_rcu *inet_opt;
1127 
1128 		inet_opt = rcu_dereference_protected(inet->inet_opt,
1129 						     sock_owned_by_user(sk));
1130 		opt->optlen = 0;
1131 		if (inet_opt)
1132 			memcpy(optbuf, &inet_opt->opt,
1133 			       sizeof(struct ip_options) +
1134 			       inet_opt->opt.optlen);
1135 		release_sock(sk);
1136 
1137 		if (opt->optlen == 0)
1138 			return put_user(0, optlen);
1139 
1140 		ip_options_undo(opt);
1141 
1142 		len = min_t(unsigned int, len, opt->optlen);
1143 		if (put_user(len, optlen))
1144 			return -EFAULT;
1145 		if (copy_to_user(optval, opt->__data, len))
1146 			return -EFAULT;
1147 		return 0;
1148 	}
1149 	case IP_PKTINFO:
1150 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1151 		break;
1152 	case IP_RECVTTL:
1153 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1154 		break;
1155 	case IP_RECVTOS:
1156 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1157 		break;
1158 	case IP_RECVOPTS:
1159 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1160 		break;
1161 	case IP_RETOPTS:
1162 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1163 		break;
1164 	case IP_PASSSEC:
1165 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1166 		break;
1167 	case IP_RECVORIGDSTADDR:
1168 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1169 		break;
1170 	case IP_TOS:
1171 		val = inet->tos;
1172 		break;
1173 	case IP_TTL:
1174 		val = (inet->uc_ttl == -1 ?
1175 		       sysctl_ip_default_ttl :
1176 		       inet->uc_ttl);
1177 		break;
1178 	case IP_HDRINCL:
1179 		val = inet->hdrincl;
1180 		break;
1181 	case IP_NODEFRAG:
1182 		val = inet->nodefrag;
1183 		break;
1184 	case IP_MTU_DISCOVER:
1185 		val = inet->pmtudisc;
1186 		break;
1187 	case IP_MTU:
1188 	{
1189 		struct dst_entry *dst;
1190 		val = 0;
1191 		dst = sk_dst_get(sk);
1192 		if (dst) {
1193 			val = dst_mtu(dst);
1194 			dst_release(dst);
1195 		}
1196 		if (!val) {
1197 			release_sock(sk);
1198 			return -ENOTCONN;
1199 		}
1200 		break;
1201 	}
1202 	case IP_RECVERR:
1203 		val = inet->recverr;
1204 		break;
1205 	case IP_MULTICAST_TTL:
1206 		val = inet->mc_ttl;
1207 		break;
1208 	case IP_MULTICAST_LOOP:
1209 		val = inet->mc_loop;
1210 		break;
1211 	case IP_UNICAST_IF:
1212 		val = (__force int)htonl((__u32) inet->uc_index);
1213 		break;
1214 	case IP_MULTICAST_IF:
1215 	{
1216 		struct in_addr addr;
1217 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1218 		addr.s_addr = inet->mc_addr;
1219 		release_sock(sk);
1220 
1221 		if (put_user(len, optlen))
1222 			return -EFAULT;
1223 		if (copy_to_user(optval, &addr, len))
1224 			return -EFAULT;
1225 		return 0;
1226 	}
1227 	case IP_MSFILTER:
1228 	{
1229 		struct ip_msfilter msf;
1230 		int err;
1231 
1232 		if (len < IP_MSFILTER_SIZE(0)) {
1233 			release_sock(sk);
1234 			return -EINVAL;
1235 		}
1236 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1237 			release_sock(sk);
1238 			return -EFAULT;
1239 		}
1240 		err = ip_mc_msfget(sk, &msf,
1241 				   (struct ip_msfilter __user *)optval, optlen);
1242 		release_sock(sk);
1243 		return err;
1244 	}
1245 	case MCAST_MSFILTER:
1246 	{
1247 		struct group_filter gsf;
1248 		int err;
1249 
1250 		if (len < GROUP_FILTER_SIZE(0)) {
1251 			release_sock(sk);
1252 			return -EINVAL;
1253 		}
1254 		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1255 			release_sock(sk);
1256 			return -EFAULT;
1257 		}
1258 		err = ip_mc_gsfget(sk, &gsf,
1259 				   (struct group_filter __user *)optval,
1260 				   optlen);
1261 		release_sock(sk);
1262 		return err;
1263 	}
1264 	case IP_MULTICAST_ALL:
1265 		val = inet->mc_all;
1266 		break;
1267 	case IP_PKTOPTIONS:
1268 	{
1269 		struct msghdr msg;
1270 
1271 		release_sock(sk);
1272 
1273 		if (sk->sk_type != SOCK_STREAM)
1274 			return -ENOPROTOOPT;
1275 
1276 		msg.msg_control = optval;
1277 		msg.msg_controllen = len;
1278 		msg.msg_flags = flags;
1279 
1280 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1281 			struct in_pktinfo info;
1282 
1283 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1284 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1285 			info.ipi_ifindex = inet->mc_index;
1286 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1287 		}
1288 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1289 			int hlim = inet->mc_ttl;
1290 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1291 		}
1292 		if (inet->cmsg_flags & IP_CMSG_TOS) {
1293 			int tos = inet->rcv_tos;
1294 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1295 		}
1296 		len -= msg.msg_controllen;
1297 		return put_user(len, optlen);
1298 	}
1299 	case IP_FREEBIND:
1300 		val = inet->freebind;
1301 		break;
1302 	case IP_TRANSPARENT:
1303 		val = inet->transparent;
1304 		break;
1305 	case IP_MINTTL:
1306 		val = inet->min_ttl;
1307 		break;
1308 	default:
1309 		release_sock(sk);
1310 		return -ENOPROTOOPT;
1311 	}
1312 	release_sock(sk);
1313 
1314 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1315 		unsigned char ucval = (unsigned char)val;
1316 		len = 1;
1317 		if (put_user(len, optlen))
1318 			return -EFAULT;
1319 		if (copy_to_user(optval, &ucval, 1))
1320 			return -EFAULT;
1321 	} else {
1322 		len = min_t(unsigned int, sizeof(int), len);
1323 		if (put_user(len, optlen))
1324 			return -EFAULT;
1325 		if (copy_to_user(optval, &val, len))
1326 			return -EFAULT;
1327 	}
1328 	return 0;
1329 }
1330 
1331 int ip_getsockopt(struct sock *sk, int level,
1332 		  int optname, char __user *optval, int __user *optlen)
1333 {
1334 	int err;
1335 
1336 	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1337 #ifdef CONFIG_NETFILTER
1338 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1339 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1340 			!ip_mroute_opt(optname)) {
1341 		int len;
1342 
1343 		if (get_user(len, optlen))
1344 			return -EFAULT;
1345 
1346 		lock_sock(sk);
1347 		err = nf_getsockopt(sk, PF_INET, optname, optval,
1348 				&len);
1349 		release_sock(sk);
1350 		if (err >= 0)
1351 			err = put_user(len, optlen);
1352 		return err;
1353 	}
1354 #endif
1355 	return err;
1356 }
1357 EXPORT_SYMBOL(ip_getsockopt);
1358 
1359 #ifdef CONFIG_COMPAT
1360 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1361 			 char __user *optval, int __user *optlen)
1362 {
1363 	int err;
1364 
1365 	if (optname == MCAST_MSFILTER)
1366 		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1367 			ip_getsockopt);
1368 
1369 	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1370 		MSG_CMSG_COMPAT);
1371 
1372 #ifdef CONFIG_NETFILTER
1373 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1374 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1375 			!ip_mroute_opt(optname)) {
1376 		int len;
1377 
1378 		if (get_user(len, optlen))
1379 			return -EFAULT;
1380 
1381 		lock_sock(sk);
1382 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1383 		release_sock(sk);
1384 		if (err >= 0)
1385 			err = put_user(len, optlen);
1386 		return err;
1387 	}
1388 #endif
1389 	return err;
1390 }
1391 EXPORT_SYMBOL(compat_ip_getsockopt);
1392 #endif
1393