xref: /linux/net/ipv4/ip_sockglue.c (revision 32786fdc9506aeba98278c1844d4bfb766863832)
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 #include <net/checksum.h>
41 #if IS_ENABLED(CONFIG_IPV6)
42 #include <net/transp_v6.h>
43 #endif
44 #include <net/ip_fib.h>
45 
46 #include <linux/errqueue.h>
47 #include <asm/uaccess.h>
48 
49 /*
50  *	SOL_IP control messages.
51  */
52 
53 static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
54 {
55 	struct in_pktinfo info = *PKTINFO_SKB_CB(skb);
56 
57 	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
58 
59 	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
60 }
61 
62 static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
63 {
64 	int ttl = ip_hdr(skb)->ttl;
65 	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
66 }
67 
68 static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
69 {
70 	put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
71 }
72 
73 static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
74 {
75 	if (IPCB(skb)->opt.optlen == 0)
76 		return;
77 
78 	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
79 		 ip_hdr(skb) + 1);
80 }
81 
82 
83 static void ip_cmsg_recv_retopts(struct msghdr *msg, struct sk_buff *skb)
84 {
85 	unsigned char optbuf[sizeof(struct ip_options) + 40];
86 	struct ip_options *opt = (struct ip_options *)optbuf;
87 
88 	if (IPCB(skb)->opt.optlen == 0)
89 		return;
90 
91 	if (ip_options_echo(opt, skb)) {
92 		msg->msg_flags |= MSG_CTRUNC;
93 		return;
94 	}
95 	ip_options_undo(opt);
96 
97 	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
98 }
99 
100 static void ip_cmsg_recv_fragsize(struct msghdr *msg, struct sk_buff *skb)
101 {
102 	int val;
103 
104 	if (IPCB(skb)->frag_max_size == 0)
105 		return;
106 
107 	val = IPCB(skb)->frag_max_size;
108 	put_cmsg(msg, SOL_IP, IP_RECVFRAGSIZE, sizeof(val), &val);
109 }
110 
111 static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
112 				  int tlen, int offset)
113 {
114 	__wsum csum = skb->csum;
115 
116 	if (skb->ip_summed != CHECKSUM_COMPLETE)
117 		return;
118 
119 	if (offset != 0)
120 		csum = csum_sub(csum,
121 				csum_partial(skb_transport_header(skb) + tlen,
122 					     offset, 0));
123 
124 	put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum);
125 }
126 
127 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
128 {
129 	char *secdata;
130 	u32 seclen, secid;
131 	int err;
132 
133 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
134 	if (err)
135 		return;
136 
137 	err = security_secid_to_secctx(secid, &secdata, &seclen);
138 	if (err)
139 		return;
140 
141 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
142 	security_release_secctx(secdata, seclen);
143 }
144 
145 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
146 {
147 	struct sockaddr_in sin;
148 	const struct iphdr *iph = ip_hdr(skb);
149 	__be16 *ports = (__be16 *)skb_transport_header(skb);
150 
151 	if (skb_transport_offset(skb) + 4 > skb->len)
152 		return;
153 
154 	/* All current transport protocols have the port numbers in the
155 	 * first four bytes of the transport header and this function is
156 	 * written with this assumption in mind.
157 	 */
158 
159 	sin.sin_family = AF_INET;
160 	sin.sin_addr.s_addr = iph->daddr;
161 	sin.sin_port = ports[1];
162 	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
163 
164 	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
165 }
166 
167 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
168 			 struct sk_buff *skb, int tlen, int offset)
169 {
170 	struct inet_sock *inet = inet_sk(sk);
171 	unsigned int flags = inet->cmsg_flags;
172 
173 	/* Ordered by supposed usage frequency */
174 	if (flags & IP_CMSG_PKTINFO) {
175 		ip_cmsg_recv_pktinfo(msg, skb);
176 
177 		flags &= ~IP_CMSG_PKTINFO;
178 		if (!flags)
179 			return;
180 	}
181 
182 	if (flags & IP_CMSG_TTL) {
183 		ip_cmsg_recv_ttl(msg, skb);
184 
185 		flags &= ~IP_CMSG_TTL;
186 		if (!flags)
187 			return;
188 	}
189 
190 	if (flags & IP_CMSG_TOS) {
191 		ip_cmsg_recv_tos(msg, skb);
192 
193 		flags &= ~IP_CMSG_TOS;
194 		if (!flags)
195 			return;
196 	}
197 
198 	if (flags & IP_CMSG_RECVOPTS) {
199 		ip_cmsg_recv_opts(msg, skb);
200 
201 		flags &= ~IP_CMSG_RECVOPTS;
202 		if (!flags)
203 			return;
204 	}
205 
206 	if (flags & IP_CMSG_RETOPTS) {
207 		ip_cmsg_recv_retopts(msg, skb);
208 
209 		flags &= ~IP_CMSG_RETOPTS;
210 		if (!flags)
211 			return;
212 	}
213 
214 	if (flags & IP_CMSG_PASSSEC) {
215 		ip_cmsg_recv_security(msg, skb);
216 
217 		flags &= ~IP_CMSG_PASSSEC;
218 		if (!flags)
219 			return;
220 	}
221 
222 	if (flags & IP_CMSG_ORIGDSTADDR) {
223 		ip_cmsg_recv_dstaddr(msg, skb);
224 
225 		flags &= ~IP_CMSG_ORIGDSTADDR;
226 		if (!flags)
227 			return;
228 	}
229 
230 	if (flags & IP_CMSG_CHECKSUM)
231 		ip_cmsg_recv_checksum(msg, skb, tlen, offset);
232 
233 	if (flags & IP_CMSG_RECVFRAGSIZE)
234 		ip_cmsg_recv_fragsize(msg, skb);
235 }
236 EXPORT_SYMBOL(ip_cmsg_recv_offset);
237 
238 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc,
239 		 bool allow_ipv6)
240 {
241 	int err, val;
242 	struct cmsghdr *cmsg;
243 	struct net *net = sock_net(sk);
244 
245 	for_each_cmsghdr(cmsg, msg) {
246 		if (!CMSG_OK(msg, cmsg))
247 			return -EINVAL;
248 #if IS_ENABLED(CONFIG_IPV6)
249 		if (allow_ipv6 &&
250 		    cmsg->cmsg_level == SOL_IPV6 &&
251 		    cmsg->cmsg_type == IPV6_PKTINFO) {
252 			struct in6_pktinfo *src_info;
253 
254 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info)))
255 				return -EINVAL;
256 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
257 			if (!ipv6_addr_v4mapped(&src_info->ipi6_addr))
258 				return -EINVAL;
259 			ipc->oif = src_info->ipi6_ifindex;
260 			ipc->addr = src_info->ipi6_addr.s6_addr32[3];
261 			continue;
262 		}
263 #endif
264 		if (cmsg->cmsg_level == SOL_SOCKET) {
265 			err = __sock_cmsg_send(sk, msg, cmsg, &ipc->sockc);
266 			if (err)
267 				return err;
268 			continue;
269 		}
270 
271 		if (cmsg->cmsg_level != SOL_IP)
272 			continue;
273 		switch (cmsg->cmsg_type) {
274 		case IP_RETOPTS:
275 			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
276 
277 			/* Our caller is responsible for freeing ipc->opt */
278 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
279 					     err < 40 ? err : 40);
280 			if (err)
281 				return err;
282 			break;
283 		case IP_PKTINFO:
284 		{
285 			struct in_pktinfo *info;
286 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
287 				return -EINVAL;
288 			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
289 			ipc->oif = info->ipi_ifindex;
290 			ipc->addr = info->ipi_spec_dst.s_addr;
291 			break;
292 		}
293 		case IP_TTL:
294 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
295 				return -EINVAL;
296 			val = *(int *)CMSG_DATA(cmsg);
297 			if (val < 1 || val > 255)
298 				return -EINVAL;
299 			ipc->ttl = val;
300 			break;
301 		case IP_TOS:
302 			if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)))
303 				val = *(int *)CMSG_DATA(cmsg);
304 			else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8)))
305 				val = *(u8 *)CMSG_DATA(cmsg);
306 			else
307 				return -EINVAL;
308 			if (val < 0 || val > 255)
309 				return -EINVAL;
310 			ipc->tos = val;
311 			ipc->priority = rt_tos2priority(ipc->tos);
312 			break;
313 
314 		default:
315 			return -EINVAL;
316 		}
317 	}
318 	return 0;
319 }
320 
321 
322 /* Special input handler for packets caught by router alert option.
323    They are selected only by protocol field, and then processed likely
324    local ones; but only if someone wants them! Otherwise, router
325    not running rsvpd will kill RSVP.
326 
327    It is user level problem, what it will make with them.
328    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
329    but receiver should be enough clever f.e. to forward mtrace requests,
330    sent to multicast group to reach destination designated router.
331  */
332 struct ip_ra_chain __rcu *ip_ra_chain;
333 static DEFINE_SPINLOCK(ip_ra_lock);
334 
335 
336 static void ip_ra_destroy_rcu(struct rcu_head *head)
337 {
338 	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
339 
340 	sock_put(ra->saved_sk);
341 	kfree(ra);
342 }
343 
344 int ip_ra_control(struct sock *sk, unsigned char on,
345 		  void (*destructor)(struct sock *))
346 {
347 	struct ip_ra_chain *ra, *new_ra;
348 	struct ip_ra_chain __rcu **rap;
349 
350 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
351 		return -EINVAL;
352 
353 	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
354 
355 	spin_lock_bh(&ip_ra_lock);
356 	for (rap = &ip_ra_chain;
357 	     (ra = rcu_dereference_protected(*rap,
358 			lockdep_is_held(&ip_ra_lock))) != NULL;
359 	     rap = &ra->next) {
360 		if (ra->sk == sk) {
361 			if (on) {
362 				spin_unlock_bh(&ip_ra_lock);
363 				kfree(new_ra);
364 				return -EADDRINUSE;
365 			}
366 			/* dont let ip_call_ra_chain() use sk again */
367 			ra->sk = NULL;
368 			RCU_INIT_POINTER(*rap, ra->next);
369 			spin_unlock_bh(&ip_ra_lock);
370 
371 			if (ra->destructor)
372 				ra->destructor(sk);
373 			/*
374 			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
375 			 * period. This guarantee ip_call_ra_chain() dont need
376 			 * to mess with socket refcounts.
377 			 */
378 			ra->saved_sk = sk;
379 			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
380 			return 0;
381 		}
382 	}
383 	if (!new_ra) {
384 		spin_unlock_bh(&ip_ra_lock);
385 		return -ENOBUFS;
386 	}
387 	new_ra->sk = sk;
388 	new_ra->destructor = destructor;
389 
390 	RCU_INIT_POINTER(new_ra->next, ra);
391 	rcu_assign_pointer(*rap, new_ra);
392 	sock_hold(sk);
393 	spin_unlock_bh(&ip_ra_lock);
394 
395 	return 0;
396 }
397 
398 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
399 		   __be16 port, u32 info, u8 *payload)
400 {
401 	struct sock_exterr_skb *serr;
402 
403 	skb = skb_clone(skb, GFP_ATOMIC);
404 	if (!skb)
405 		return;
406 
407 	serr = SKB_EXT_ERR(skb);
408 	serr->ee.ee_errno = err;
409 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
410 	serr->ee.ee_type = icmp_hdr(skb)->type;
411 	serr->ee.ee_code = icmp_hdr(skb)->code;
412 	serr->ee.ee_pad = 0;
413 	serr->ee.ee_info = info;
414 	serr->ee.ee_data = 0;
415 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
416 				   skb_network_header(skb);
417 	serr->port = port;
418 
419 	if (skb_pull(skb, payload - skb->data)) {
420 		skb_reset_transport_header(skb);
421 		if (sock_queue_err_skb(sk, skb) == 0)
422 			return;
423 	}
424 	kfree_skb(skb);
425 }
426 
427 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
428 {
429 	struct inet_sock *inet = inet_sk(sk);
430 	struct sock_exterr_skb *serr;
431 	struct iphdr *iph;
432 	struct sk_buff *skb;
433 
434 	if (!inet->recverr)
435 		return;
436 
437 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
438 	if (!skb)
439 		return;
440 
441 	skb_put(skb, sizeof(struct iphdr));
442 	skb_reset_network_header(skb);
443 	iph = ip_hdr(skb);
444 	iph->daddr = daddr;
445 
446 	serr = SKB_EXT_ERR(skb);
447 	serr->ee.ee_errno = err;
448 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
449 	serr->ee.ee_type = 0;
450 	serr->ee.ee_code = 0;
451 	serr->ee.ee_pad = 0;
452 	serr->ee.ee_info = info;
453 	serr->ee.ee_data = 0;
454 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
455 	serr->port = port;
456 
457 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
458 	skb_reset_transport_header(skb);
459 
460 	if (sock_queue_err_skb(sk, skb))
461 		kfree_skb(skb);
462 }
463 
464 /* For some errors we have valid addr_offset even with zero payload and
465  * zero port. Also, addr_offset should be supported if port is set.
466  */
467 static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
468 {
469 	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
470 	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
471 }
472 
473 /* IPv4 supports cmsg on all imcp errors and some timestamps
474  *
475  * Timestamp code paths do not initialize the fields expected by cmsg:
476  * the PKTINFO fields in skb->cb[]. Fill those in here.
477  */
478 static bool ipv4_datagram_support_cmsg(const struct sock *sk,
479 				       struct sk_buff *skb,
480 				       int ee_origin)
481 {
482 	struct in_pktinfo *info;
483 
484 	if (ee_origin == SO_EE_ORIGIN_ICMP)
485 		return true;
486 
487 	if (ee_origin == SO_EE_ORIGIN_LOCAL)
488 		return false;
489 
490 	/* Support IP_PKTINFO on tstamp packets if requested, to correlate
491 	 * timestamp with egress dev. Not possible for packets without dev
492 	 * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
493 	 */
494 	if ((!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG)) ||
495 	    (!skb->dev))
496 		return false;
497 
498 	info = PKTINFO_SKB_CB(skb);
499 	info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
500 	info->ipi_ifindex = skb->dev->ifindex;
501 	return true;
502 }
503 
504 /*
505  *	Handle MSG_ERRQUEUE
506  */
507 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
508 {
509 	struct sock_exterr_skb *serr;
510 	struct sk_buff *skb;
511 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
512 	struct {
513 		struct sock_extended_err ee;
514 		struct sockaddr_in	 offender;
515 	} errhdr;
516 	int err;
517 	int copied;
518 
519 	WARN_ON_ONCE(sk->sk_family == AF_INET6);
520 
521 	err = -EAGAIN;
522 	skb = sock_dequeue_err_skb(sk);
523 	if (!skb)
524 		goto out;
525 
526 	copied = skb->len;
527 	if (copied > len) {
528 		msg->msg_flags |= MSG_TRUNC;
529 		copied = len;
530 	}
531 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
532 	if (unlikely(err)) {
533 		kfree_skb(skb);
534 		return err;
535 	}
536 	sock_recv_timestamp(msg, sk, skb);
537 
538 	serr = SKB_EXT_ERR(skb);
539 
540 	if (sin && ipv4_datagram_support_addr(serr)) {
541 		sin->sin_family = AF_INET;
542 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
543 						   serr->addr_offset);
544 		sin->sin_port = serr->port;
545 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
546 		*addr_len = sizeof(*sin);
547 	}
548 
549 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
550 	sin = &errhdr.offender;
551 	memset(sin, 0, sizeof(*sin));
552 
553 	if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
554 		sin->sin_family = AF_INET;
555 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
556 		if (inet_sk(sk)->cmsg_flags)
557 			ip_cmsg_recv(msg, skb);
558 	}
559 
560 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
561 
562 	/* Now we could try to dump offended packet options */
563 
564 	msg->msg_flags |= MSG_ERRQUEUE;
565 	err = copied;
566 
567 	consume_skb(skb);
568 out:
569 	return err;
570 }
571 
572 
573 /*
574  *	Socket option code for IP. This is the end of the line after any
575  *	TCP,UDP etc options on an IP socket.
576  */
577 static bool setsockopt_needs_rtnl(int optname)
578 {
579 	switch (optname) {
580 	case IP_ADD_MEMBERSHIP:
581 	case IP_ADD_SOURCE_MEMBERSHIP:
582 	case IP_BLOCK_SOURCE:
583 	case IP_DROP_MEMBERSHIP:
584 	case IP_DROP_SOURCE_MEMBERSHIP:
585 	case IP_MSFILTER:
586 	case IP_UNBLOCK_SOURCE:
587 	case MCAST_BLOCK_SOURCE:
588 	case MCAST_MSFILTER:
589 	case MCAST_JOIN_GROUP:
590 	case MCAST_JOIN_SOURCE_GROUP:
591 	case MCAST_LEAVE_GROUP:
592 	case MCAST_LEAVE_SOURCE_GROUP:
593 	case MCAST_UNBLOCK_SOURCE:
594 		return true;
595 	}
596 	return false;
597 }
598 
599 static int do_ip_setsockopt(struct sock *sk, int level,
600 			    int optname, char __user *optval, unsigned int optlen)
601 {
602 	struct inet_sock *inet = inet_sk(sk);
603 	struct net *net = sock_net(sk);
604 	int val = 0, err;
605 	bool needs_rtnl = setsockopt_needs_rtnl(optname);
606 
607 	switch (optname) {
608 	case IP_PKTINFO:
609 	case IP_RECVTTL:
610 	case IP_RECVOPTS:
611 	case IP_RECVTOS:
612 	case IP_RETOPTS:
613 	case IP_TOS:
614 	case IP_TTL:
615 	case IP_HDRINCL:
616 	case IP_MTU_DISCOVER:
617 	case IP_RECVERR:
618 	case IP_ROUTER_ALERT:
619 	case IP_FREEBIND:
620 	case IP_PASSSEC:
621 	case IP_TRANSPARENT:
622 	case IP_MINTTL:
623 	case IP_NODEFRAG:
624 	case IP_BIND_ADDRESS_NO_PORT:
625 	case IP_UNICAST_IF:
626 	case IP_MULTICAST_TTL:
627 	case IP_MULTICAST_ALL:
628 	case IP_MULTICAST_LOOP:
629 	case IP_RECVORIGDSTADDR:
630 	case IP_CHECKSUM:
631 	case IP_RECVFRAGSIZE:
632 		if (optlen >= sizeof(int)) {
633 			if (get_user(val, (int __user *) optval))
634 				return -EFAULT;
635 		} else if (optlen >= sizeof(char)) {
636 			unsigned char ucval;
637 
638 			if (get_user(ucval, (unsigned char __user *) optval))
639 				return -EFAULT;
640 			val = (int) ucval;
641 		}
642 	}
643 
644 	/* If optlen==0, it is equivalent to val == 0 */
645 
646 	if (ip_mroute_opt(optname))
647 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
648 
649 	err = 0;
650 	if (needs_rtnl)
651 		rtnl_lock();
652 	lock_sock(sk);
653 
654 	switch (optname) {
655 	case IP_OPTIONS:
656 	{
657 		struct ip_options_rcu *old, *opt = NULL;
658 
659 		if (optlen > 40)
660 			goto e_inval;
661 		err = ip_options_get_from_user(sock_net(sk), &opt,
662 					       optval, optlen);
663 		if (err)
664 			break;
665 		old = rcu_dereference_protected(inet->inet_opt,
666 						lockdep_sock_is_held(sk));
667 		if (inet->is_icsk) {
668 			struct inet_connection_sock *icsk = inet_csk(sk);
669 #if IS_ENABLED(CONFIG_IPV6)
670 			if (sk->sk_family == PF_INET ||
671 			    (!((1 << sk->sk_state) &
672 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
673 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
674 #endif
675 				if (old)
676 					icsk->icsk_ext_hdr_len -= old->opt.optlen;
677 				if (opt)
678 					icsk->icsk_ext_hdr_len += opt->opt.optlen;
679 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
680 #if IS_ENABLED(CONFIG_IPV6)
681 			}
682 #endif
683 		}
684 		rcu_assign_pointer(inet->inet_opt, opt);
685 		if (old)
686 			kfree_rcu(old, rcu);
687 		break;
688 	}
689 	case IP_PKTINFO:
690 		if (val)
691 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
692 		else
693 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
694 		break;
695 	case IP_RECVTTL:
696 		if (val)
697 			inet->cmsg_flags |=  IP_CMSG_TTL;
698 		else
699 			inet->cmsg_flags &= ~IP_CMSG_TTL;
700 		break;
701 	case IP_RECVTOS:
702 		if (val)
703 			inet->cmsg_flags |=  IP_CMSG_TOS;
704 		else
705 			inet->cmsg_flags &= ~IP_CMSG_TOS;
706 		break;
707 	case IP_RECVOPTS:
708 		if (val)
709 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
710 		else
711 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
712 		break;
713 	case IP_RETOPTS:
714 		if (val)
715 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
716 		else
717 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
718 		break;
719 	case IP_PASSSEC:
720 		if (val)
721 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
722 		else
723 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
724 		break;
725 	case IP_RECVORIGDSTADDR:
726 		if (val)
727 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
728 		else
729 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
730 		break;
731 	case IP_CHECKSUM:
732 		if (val) {
733 			if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
734 				inet_inc_convert_csum(sk);
735 				inet->cmsg_flags |= IP_CMSG_CHECKSUM;
736 			}
737 		} else {
738 			if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
739 				inet_dec_convert_csum(sk);
740 				inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
741 			}
742 		}
743 		break;
744 	case IP_RECVFRAGSIZE:
745 		if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
746 			goto e_inval;
747 		if (val)
748 			inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
749 		else
750 			inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
751 		break;
752 	case IP_TOS:	/* This sets both TOS and Precedence */
753 		if (sk->sk_type == SOCK_STREAM) {
754 			val &= ~INET_ECN_MASK;
755 			val |= inet->tos & INET_ECN_MASK;
756 		}
757 		if (inet->tos != val) {
758 			inet->tos = val;
759 			sk->sk_priority = rt_tos2priority(val);
760 			sk_dst_reset(sk);
761 		}
762 		break;
763 	case IP_TTL:
764 		if (optlen < 1)
765 			goto e_inval;
766 		if (val != -1 && (val < 1 || val > 255))
767 			goto e_inval;
768 		inet->uc_ttl = val;
769 		break;
770 	case IP_HDRINCL:
771 		if (sk->sk_type != SOCK_RAW) {
772 			err = -ENOPROTOOPT;
773 			break;
774 		}
775 		inet->hdrincl = val ? 1 : 0;
776 		break;
777 	case IP_NODEFRAG:
778 		if (sk->sk_type != SOCK_RAW) {
779 			err = -ENOPROTOOPT;
780 			break;
781 		}
782 		inet->nodefrag = val ? 1 : 0;
783 		break;
784 	case IP_BIND_ADDRESS_NO_PORT:
785 		inet->bind_address_no_port = val ? 1 : 0;
786 		break;
787 	case IP_MTU_DISCOVER:
788 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
789 			goto e_inval;
790 		inet->pmtudisc = val;
791 		break;
792 	case IP_RECVERR:
793 		inet->recverr = !!val;
794 		if (!val)
795 			skb_queue_purge(&sk->sk_error_queue);
796 		break;
797 	case IP_MULTICAST_TTL:
798 		if (sk->sk_type == SOCK_STREAM)
799 			goto e_inval;
800 		if (optlen < 1)
801 			goto e_inval;
802 		if (val == -1)
803 			val = 1;
804 		if (val < 0 || val > 255)
805 			goto e_inval;
806 		inet->mc_ttl = val;
807 		break;
808 	case IP_MULTICAST_LOOP:
809 		if (optlen < 1)
810 			goto e_inval;
811 		inet->mc_loop = !!val;
812 		break;
813 	case IP_UNICAST_IF:
814 	{
815 		struct net_device *dev = NULL;
816 		int ifindex;
817 
818 		if (optlen != sizeof(int))
819 			goto e_inval;
820 
821 		ifindex = (__force int)ntohl((__force __be32)val);
822 		if (ifindex == 0) {
823 			inet->uc_index = 0;
824 			err = 0;
825 			break;
826 		}
827 
828 		dev = dev_get_by_index(sock_net(sk), ifindex);
829 		err = -EADDRNOTAVAIL;
830 		if (!dev)
831 			break;
832 		dev_put(dev);
833 
834 		err = -EINVAL;
835 		if (sk->sk_bound_dev_if)
836 			break;
837 
838 		inet->uc_index = ifindex;
839 		err = 0;
840 		break;
841 	}
842 	case IP_MULTICAST_IF:
843 	{
844 		struct ip_mreqn mreq;
845 		struct net_device *dev = NULL;
846 
847 		if (sk->sk_type == SOCK_STREAM)
848 			goto e_inval;
849 		/*
850 		 *	Check the arguments are allowable
851 		 */
852 
853 		if (optlen < sizeof(struct in_addr))
854 			goto e_inval;
855 
856 		err = -EFAULT;
857 		if (optlen >= sizeof(struct ip_mreqn)) {
858 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
859 				break;
860 		} else {
861 			memset(&mreq, 0, sizeof(mreq));
862 			if (optlen >= sizeof(struct ip_mreq)) {
863 				if (copy_from_user(&mreq, optval,
864 						   sizeof(struct ip_mreq)))
865 					break;
866 			} else if (optlen >= sizeof(struct in_addr)) {
867 				if (copy_from_user(&mreq.imr_address, optval,
868 						   sizeof(struct in_addr)))
869 					break;
870 			}
871 		}
872 
873 		if (!mreq.imr_ifindex) {
874 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
875 				inet->mc_index = 0;
876 				inet->mc_addr  = 0;
877 				err = 0;
878 				break;
879 			}
880 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
881 			if (dev)
882 				mreq.imr_ifindex = dev->ifindex;
883 		} else
884 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
885 
886 
887 		err = -EADDRNOTAVAIL;
888 		if (!dev)
889 			break;
890 		dev_put(dev);
891 
892 		err = -EINVAL;
893 		if (sk->sk_bound_dev_if &&
894 		    mreq.imr_ifindex != sk->sk_bound_dev_if)
895 			break;
896 
897 		inet->mc_index = mreq.imr_ifindex;
898 		inet->mc_addr  = mreq.imr_address.s_addr;
899 		err = 0;
900 		break;
901 	}
902 
903 	case IP_ADD_MEMBERSHIP:
904 	case IP_DROP_MEMBERSHIP:
905 	{
906 		struct ip_mreqn mreq;
907 
908 		err = -EPROTO;
909 		if (inet_sk(sk)->is_icsk)
910 			break;
911 
912 		if (optlen < sizeof(struct ip_mreq))
913 			goto e_inval;
914 		err = -EFAULT;
915 		if (optlen >= sizeof(struct ip_mreqn)) {
916 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
917 				break;
918 		} else {
919 			memset(&mreq, 0, sizeof(mreq));
920 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
921 				break;
922 		}
923 
924 		if (optname == IP_ADD_MEMBERSHIP)
925 			err = ip_mc_join_group(sk, &mreq);
926 		else
927 			err = ip_mc_leave_group(sk, &mreq);
928 		break;
929 	}
930 	case IP_MSFILTER:
931 	{
932 		struct ip_msfilter *msf;
933 
934 		if (optlen < IP_MSFILTER_SIZE(0))
935 			goto e_inval;
936 		if (optlen > sysctl_optmem_max) {
937 			err = -ENOBUFS;
938 			break;
939 		}
940 		msf = kmalloc(optlen, GFP_KERNEL);
941 		if (!msf) {
942 			err = -ENOBUFS;
943 			break;
944 		}
945 		err = -EFAULT;
946 		if (copy_from_user(msf, optval, optlen)) {
947 			kfree(msf);
948 			break;
949 		}
950 		/* numsrc >= (1G-4) overflow in 32 bits */
951 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
952 		    msf->imsf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
953 			kfree(msf);
954 			err = -ENOBUFS;
955 			break;
956 		}
957 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
958 			kfree(msf);
959 			err = -EINVAL;
960 			break;
961 		}
962 		err = ip_mc_msfilter(sk, msf, 0);
963 		kfree(msf);
964 		break;
965 	}
966 	case IP_BLOCK_SOURCE:
967 	case IP_UNBLOCK_SOURCE:
968 	case IP_ADD_SOURCE_MEMBERSHIP:
969 	case IP_DROP_SOURCE_MEMBERSHIP:
970 	{
971 		struct ip_mreq_source mreqs;
972 		int omode, add;
973 
974 		if (optlen != sizeof(struct ip_mreq_source))
975 			goto e_inval;
976 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
977 			err = -EFAULT;
978 			break;
979 		}
980 		if (optname == IP_BLOCK_SOURCE) {
981 			omode = MCAST_EXCLUDE;
982 			add = 1;
983 		} else if (optname == IP_UNBLOCK_SOURCE) {
984 			omode = MCAST_EXCLUDE;
985 			add = 0;
986 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
987 			struct ip_mreqn mreq;
988 
989 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
990 			mreq.imr_address.s_addr = mreqs.imr_interface;
991 			mreq.imr_ifindex = 0;
992 			err = ip_mc_join_group(sk, &mreq);
993 			if (err && err != -EADDRINUSE)
994 				break;
995 			omode = MCAST_INCLUDE;
996 			add = 1;
997 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
998 			omode = MCAST_INCLUDE;
999 			add = 0;
1000 		}
1001 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
1002 		break;
1003 	}
1004 	case MCAST_JOIN_GROUP:
1005 	case MCAST_LEAVE_GROUP:
1006 	{
1007 		struct group_req greq;
1008 		struct sockaddr_in *psin;
1009 		struct ip_mreqn mreq;
1010 
1011 		if (optlen < sizeof(struct group_req))
1012 			goto e_inval;
1013 		err = -EFAULT;
1014 		if (copy_from_user(&greq, optval, sizeof(greq)))
1015 			break;
1016 		psin = (struct sockaddr_in *)&greq.gr_group;
1017 		if (psin->sin_family != AF_INET)
1018 			goto e_inval;
1019 		memset(&mreq, 0, sizeof(mreq));
1020 		mreq.imr_multiaddr = psin->sin_addr;
1021 		mreq.imr_ifindex = greq.gr_interface;
1022 
1023 		if (optname == MCAST_JOIN_GROUP)
1024 			err = ip_mc_join_group(sk, &mreq);
1025 		else
1026 			err = ip_mc_leave_group(sk, &mreq);
1027 		break;
1028 	}
1029 	case MCAST_JOIN_SOURCE_GROUP:
1030 	case MCAST_LEAVE_SOURCE_GROUP:
1031 	case MCAST_BLOCK_SOURCE:
1032 	case MCAST_UNBLOCK_SOURCE:
1033 	{
1034 		struct group_source_req greqs;
1035 		struct ip_mreq_source mreqs;
1036 		struct sockaddr_in *psin;
1037 		int omode, add;
1038 
1039 		if (optlen != sizeof(struct group_source_req))
1040 			goto e_inval;
1041 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
1042 			err = -EFAULT;
1043 			break;
1044 		}
1045 		if (greqs.gsr_group.ss_family != AF_INET ||
1046 		    greqs.gsr_source.ss_family != AF_INET) {
1047 			err = -EADDRNOTAVAIL;
1048 			break;
1049 		}
1050 		psin = (struct sockaddr_in *)&greqs.gsr_group;
1051 		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
1052 		psin = (struct sockaddr_in *)&greqs.gsr_source;
1053 		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
1054 		mreqs.imr_interface = 0; /* use index for mc_source */
1055 
1056 		if (optname == MCAST_BLOCK_SOURCE) {
1057 			omode = MCAST_EXCLUDE;
1058 			add = 1;
1059 		} else if (optname == MCAST_UNBLOCK_SOURCE) {
1060 			omode = MCAST_EXCLUDE;
1061 			add = 0;
1062 		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
1063 			struct ip_mreqn mreq;
1064 
1065 			psin = (struct sockaddr_in *)&greqs.gsr_group;
1066 			mreq.imr_multiaddr = psin->sin_addr;
1067 			mreq.imr_address.s_addr = 0;
1068 			mreq.imr_ifindex = greqs.gsr_interface;
1069 			err = ip_mc_join_group(sk, &mreq);
1070 			if (err && err != -EADDRINUSE)
1071 				break;
1072 			greqs.gsr_interface = mreq.imr_ifindex;
1073 			omode = MCAST_INCLUDE;
1074 			add = 1;
1075 		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
1076 			omode = MCAST_INCLUDE;
1077 			add = 0;
1078 		}
1079 		err = ip_mc_source(add, omode, sk, &mreqs,
1080 				   greqs.gsr_interface);
1081 		break;
1082 	}
1083 	case MCAST_MSFILTER:
1084 	{
1085 		struct sockaddr_in *psin;
1086 		struct ip_msfilter *msf = NULL;
1087 		struct group_filter *gsf = NULL;
1088 		int msize, i, ifindex;
1089 
1090 		if (optlen < GROUP_FILTER_SIZE(0))
1091 			goto e_inval;
1092 		if (optlen > sysctl_optmem_max) {
1093 			err = -ENOBUFS;
1094 			break;
1095 		}
1096 		gsf = kmalloc(optlen, GFP_KERNEL);
1097 		if (!gsf) {
1098 			err = -ENOBUFS;
1099 			break;
1100 		}
1101 		err = -EFAULT;
1102 		if (copy_from_user(gsf, optval, optlen))
1103 			goto mc_msf_out;
1104 
1105 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
1106 		if (gsf->gf_numsrc >= 0x1ffffff ||
1107 		    gsf->gf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
1108 			err = -ENOBUFS;
1109 			goto mc_msf_out;
1110 		}
1111 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
1112 			err = -EINVAL;
1113 			goto mc_msf_out;
1114 		}
1115 		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
1116 		msf = kmalloc(msize, GFP_KERNEL);
1117 		if (!msf) {
1118 			err = -ENOBUFS;
1119 			goto mc_msf_out;
1120 		}
1121 		ifindex = gsf->gf_interface;
1122 		psin = (struct sockaddr_in *)&gsf->gf_group;
1123 		if (psin->sin_family != AF_INET) {
1124 			err = -EADDRNOTAVAIL;
1125 			goto mc_msf_out;
1126 		}
1127 		msf->imsf_multiaddr = psin->sin_addr.s_addr;
1128 		msf->imsf_interface = 0;
1129 		msf->imsf_fmode = gsf->gf_fmode;
1130 		msf->imsf_numsrc = gsf->gf_numsrc;
1131 		err = -EADDRNOTAVAIL;
1132 		for (i = 0; i < gsf->gf_numsrc; ++i) {
1133 			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
1134 
1135 			if (psin->sin_family != AF_INET)
1136 				goto mc_msf_out;
1137 			msf->imsf_slist[i] = psin->sin_addr.s_addr;
1138 		}
1139 		kfree(gsf);
1140 		gsf = NULL;
1141 
1142 		err = ip_mc_msfilter(sk, msf, ifindex);
1143 mc_msf_out:
1144 		kfree(msf);
1145 		kfree(gsf);
1146 		break;
1147 	}
1148 	case IP_MULTICAST_ALL:
1149 		if (optlen < 1)
1150 			goto e_inval;
1151 		if (val != 0 && val != 1)
1152 			goto e_inval;
1153 		inet->mc_all = val;
1154 		break;
1155 	case IP_ROUTER_ALERT:
1156 		err = ip_ra_control(sk, val ? 1 : 0, NULL);
1157 		break;
1158 
1159 	case IP_FREEBIND:
1160 		if (optlen < 1)
1161 			goto e_inval;
1162 		inet->freebind = !!val;
1163 		break;
1164 
1165 	case IP_IPSEC_POLICY:
1166 	case IP_XFRM_POLICY:
1167 		err = -EPERM;
1168 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1169 			break;
1170 		err = xfrm_user_policy(sk, optname, optval, optlen);
1171 		break;
1172 
1173 	case IP_TRANSPARENT:
1174 		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1175 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1176 			err = -EPERM;
1177 			break;
1178 		}
1179 		if (optlen < 1)
1180 			goto e_inval;
1181 		inet->transparent = !!val;
1182 		break;
1183 
1184 	case IP_MINTTL:
1185 		if (optlen < 1)
1186 			goto e_inval;
1187 		if (val < 0 || val > 255)
1188 			goto e_inval;
1189 		inet->min_ttl = val;
1190 		break;
1191 
1192 	default:
1193 		err = -ENOPROTOOPT;
1194 		break;
1195 	}
1196 	release_sock(sk);
1197 	if (needs_rtnl)
1198 		rtnl_unlock();
1199 	return err;
1200 
1201 e_inval:
1202 	release_sock(sk);
1203 	if (needs_rtnl)
1204 		rtnl_unlock();
1205 	return -EINVAL;
1206 }
1207 
1208 /**
1209  * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1210  * @sk: socket
1211  * @skb: buffer
1212  *
1213  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1214  * destination in skb->cb[] before dst drop.
1215  * This way, receiver doesn't make cache line misses to read rtable.
1216  */
1217 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1218 {
1219 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1220 	bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1221 		       ipv6_sk_rxinfo(sk);
1222 
1223 	if (prepare && skb_rtable(skb)) {
1224 		/* skb->cb is overloaded: prior to this point it is IP{6}CB
1225 		 * which has interface index (iif) as the first member of the
1226 		 * underlying inet{6}_skb_parm struct. This code then overlays
1227 		 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
1228 		 * element so the iif is picked up from the prior IPCB
1229 		 */
1230 		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1231 	} else {
1232 		pktinfo->ipi_ifindex = 0;
1233 		pktinfo->ipi_spec_dst.s_addr = 0;
1234 	}
1235 	skb_dst_drop(skb);
1236 }
1237 
1238 int ip_setsockopt(struct sock *sk, int level,
1239 		int optname, char __user *optval, unsigned int optlen)
1240 {
1241 	int err;
1242 
1243 	if (level != SOL_IP)
1244 		return -ENOPROTOOPT;
1245 
1246 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1247 #ifdef CONFIG_NETFILTER
1248 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1249 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1250 			optname != IP_IPSEC_POLICY &&
1251 			optname != IP_XFRM_POLICY &&
1252 			!ip_mroute_opt(optname)) {
1253 		lock_sock(sk);
1254 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1255 		release_sock(sk);
1256 	}
1257 #endif
1258 	return err;
1259 }
1260 EXPORT_SYMBOL(ip_setsockopt);
1261 
1262 #ifdef CONFIG_COMPAT
1263 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1264 			 char __user *optval, unsigned int optlen)
1265 {
1266 	int err;
1267 
1268 	if (level != SOL_IP)
1269 		return -ENOPROTOOPT;
1270 
1271 	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1272 		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1273 			ip_setsockopt);
1274 
1275 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1276 #ifdef CONFIG_NETFILTER
1277 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1278 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1279 			optname != IP_IPSEC_POLICY &&
1280 			optname != IP_XFRM_POLICY &&
1281 			!ip_mroute_opt(optname)) {
1282 		lock_sock(sk);
1283 		err = compat_nf_setsockopt(sk, PF_INET, optname,
1284 					   optval, optlen);
1285 		release_sock(sk);
1286 	}
1287 #endif
1288 	return err;
1289 }
1290 EXPORT_SYMBOL(compat_ip_setsockopt);
1291 #endif
1292 
1293 /*
1294  *	Get the options. Note for future reference. The GET of IP options gets
1295  *	the _received_ ones. The set sets the _sent_ ones.
1296  */
1297 
1298 static bool getsockopt_needs_rtnl(int optname)
1299 {
1300 	switch (optname) {
1301 	case IP_MSFILTER:
1302 	case MCAST_MSFILTER:
1303 		return true;
1304 	}
1305 	return false;
1306 }
1307 
1308 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1309 			    char __user *optval, int __user *optlen, unsigned int flags)
1310 {
1311 	struct inet_sock *inet = inet_sk(sk);
1312 	bool needs_rtnl = getsockopt_needs_rtnl(optname);
1313 	int val, err = 0;
1314 	int len;
1315 
1316 	if (level != SOL_IP)
1317 		return -EOPNOTSUPP;
1318 
1319 	if (ip_mroute_opt(optname))
1320 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1321 
1322 	if (get_user(len, optlen))
1323 		return -EFAULT;
1324 	if (len < 0)
1325 		return -EINVAL;
1326 
1327 	if (needs_rtnl)
1328 		rtnl_lock();
1329 	lock_sock(sk);
1330 
1331 	switch (optname) {
1332 	case IP_OPTIONS:
1333 	{
1334 		unsigned char optbuf[sizeof(struct ip_options)+40];
1335 		struct ip_options *opt = (struct ip_options *)optbuf;
1336 		struct ip_options_rcu *inet_opt;
1337 
1338 		inet_opt = rcu_dereference_protected(inet->inet_opt,
1339 						     lockdep_sock_is_held(sk));
1340 		opt->optlen = 0;
1341 		if (inet_opt)
1342 			memcpy(optbuf, &inet_opt->opt,
1343 			       sizeof(struct ip_options) +
1344 			       inet_opt->opt.optlen);
1345 		release_sock(sk);
1346 
1347 		if (opt->optlen == 0)
1348 			return put_user(0, optlen);
1349 
1350 		ip_options_undo(opt);
1351 
1352 		len = min_t(unsigned int, len, opt->optlen);
1353 		if (put_user(len, optlen))
1354 			return -EFAULT;
1355 		if (copy_to_user(optval, opt->__data, len))
1356 			return -EFAULT;
1357 		return 0;
1358 	}
1359 	case IP_PKTINFO:
1360 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1361 		break;
1362 	case IP_RECVTTL:
1363 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1364 		break;
1365 	case IP_RECVTOS:
1366 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1367 		break;
1368 	case IP_RECVOPTS:
1369 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1370 		break;
1371 	case IP_RETOPTS:
1372 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1373 		break;
1374 	case IP_PASSSEC:
1375 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1376 		break;
1377 	case IP_RECVORIGDSTADDR:
1378 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1379 		break;
1380 	case IP_CHECKSUM:
1381 		val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1382 		break;
1383 	case IP_RECVFRAGSIZE:
1384 		val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
1385 		break;
1386 	case IP_TOS:
1387 		val = inet->tos;
1388 		break;
1389 	case IP_TTL:
1390 	{
1391 		struct net *net = sock_net(sk);
1392 		val = (inet->uc_ttl == -1 ?
1393 		       net->ipv4.sysctl_ip_default_ttl :
1394 		       inet->uc_ttl);
1395 		break;
1396 	}
1397 	case IP_HDRINCL:
1398 		val = inet->hdrincl;
1399 		break;
1400 	case IP_NODEFRAG:
1401 		val = inet->nodefrag;
1402 		break;
1403 	case IP_BIND_ADDRESS_NO_PORT:
1404 		val = inet->bind_address_no_port;
1405 		break;
1406 	case IP_MTU_DISCOVER:
1407 		val = inet->pmtudisc;
1408 		break;
1409 	case IP_MTU:
1410 	{
1411 		struct dst_entry *dst;
1412 		val = 0;
1413 		dst = sk_dst_get(sk);
1414 		if (dst) {
1415 			val = dst_mtu(dst);
1416 			dst_release(dst);
1417 		}
1418 		if (!val) {
1419 			release_sock(sk);
1420 			return -ENOTCONN;
1421 		}
1422 		break;
1423 	}
1424 	case IP_RECVERR:
1425 		val = inet->recverr;
1426 		break;
1427 	case IP_MULTICAST_TTL:
1428 		val = inet->mc_ttl;
1429 		break;
1430 	case IP_MULTICAST_LOOP:
1431 		val = inet->mc_loop;
1432 		break;
1433 	case IP_UNICAST_IF:
1434 		val = (__force int)htonl((__u32) inet->uc_index);
1435 		break;
1436 	case IP_MULTICAST_IF:
1437 	{
1438 		struct in_addr addr;
1439 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1440 		addr.s_addr = inet->mc_addr;
1441 		release_sock(sk);
1442 
1443 		if (put_user(len, optlen))
1444 			return -EFAULT;
1445 		if (copy_to_user(optval, &addr, len))
1446 			return -EFAULT;
1447 		return 0;
1448 	}
1449 	case IP_MSFILTER:
1450 	{
1451 		struct ip_msfilter msf;
1452 
1453 		if (len < IP_MSFILTER_SIZE(0)) {
1454 			err = -EINVAL;
1455 			goto out;
1456 		}
1457 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1458 			err = -EFAULT;
1459 			goto out;
1460 		}
1461 		err = ip_mc_msfget(sk, &msf,
1462 				   (struct ip_msfilter __user *)optval, optlen);
1463 		goto out;
1464 	}
1465 	case MCAST_MSFILTER:
1466 	{
1467 		struct group_filter gsf;
1468 
1469 		if (len < GROUP_FILTER_SIZE(0)) {
1470 			err = -EINVAL;
1471 			goto out;
1472 		}
1473 		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1474 			err = -EFAULT;
1475 			goto out;
1476 		}
1477 		err = ip_mc_gsfget(sk, &gsf,
1478 				   (struct group_filter __user *)optval,
1479 				   optlen);
1480 		goto out;
1481 	}
1482 	case IP_MULTICAST_ALL:
1483 		val = inet->mc_all;
1484 		break;
1485 	case IP_PKTOPTIONS:
1486 	{
1487 		struct msghdr msg;
1488 
1489 		release_sock(sk);
1490 
1491 		if (sk->sk_type != SOCK_STREAM)
1492 			return -ENOPROTOOPT;
1493 
1494 		msg.msg_control = (__force void *) optval;
1495 		msg.msg_controllen = len;
1496 		msg.msg_flags = flags;
1497 
1498 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1499 			struct in_pktinfo info;
1500 
1501 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1502 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1503 			info.ipi_ifindex = inet->mc_index;
1504 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1505 		}
1506 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1507 			int hlim = inet->mc_ttl;
1508 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1509 		}
1510 		if (inet->cmsg_flags & IP_CMSG_TOS) {
1511 			int tos = inet->rcv_tos;
1512 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1513 		}
1514 		len -= msg.msg_controllen;
1515 		return put_user(len, optlen);
1516 	}
1517 	case IP_FREEBIND:
1518 		val = inet->freebind;
1519 		break;
1520 	case IP_TRANSPARENT:
1521 		val = inet->transparent;
1522 		break;
1523 	case IP_MINTTL:
1524 		val = inet->min_ttl;
1525 		break;
1526 	default:
1527 		release_sock(sk);
1528 		return -ENOPROTOOPT;
1529 	}
1530 	release_sock(sk);
1531 
1532 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1533 		unsigned char ucval = (unsigned char)val;
1534 		len = 1;
1535 		if (put_user(len, optlen))
1536 			return -EFAULT;
1537 		if (copy_to_user(optval, &ucval, 1))
1538 			return -EFAULT;
1539 	} else {
1540 		len = min_t(unsigned int, sizeof(int), len);
1541 		if (put_user(len, optlen))
1542 			return -EFAULT;
1543 		if (copy_to_user(optval, &val, len))
1544 			return -EFAULT;
1545 	}
1546 	return 0;
1547 
1548 out:
1549 	release_sock(sk);
1550 	if (needs_rtnl)
1551 		rtnl_unlock();
1552 	return err;
1553 }
1554 
1555 int ip_getsockopt(struct sock *sk, int level,
1556 		  int optname, char __user *optval, int __user *optlen)
1557 {
1558 	int err;
1559 
1560 	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1561 #ifdef CONFIG_NETFILTER
1562 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1563 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1564 			!ip_mroute_opt(optname)) {
1565 		int len;
1566 
1567 		if (get_user(len, optlen))
1568 			return -EFAULT;
1569 
1570 		lock_sock(sk);
1571 		err = nf_getsockopt(sk, PF_INET, optname, optval,
1572 				&len);
1573 		release_sock(sk);
1574 		if (err >= 0)
1575 			err = put_user(len, optlen);
1576 		return err;
1577 	}
1578 #endif
1579 	return err;
1580 }
1581 EXPORT_SYMBOL(ip_getsockopt);
1582 
1583 #ifdef CONFIG_COMPAT
1584 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1585 			 char __user *optval, int __user *optlen)
1586 {
1587 	int err;
1588 
1589 	if (optname == MCAST_MSFILTER)
1590 		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1591 			ip_getsockopt);
1592 
1593 	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1594 		MSG_CMSG_COMPAT);
1595 
1596 #ifdef CONFIG_NETFILTER
1597 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1598 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1599 			!ip_mroute_opt(optname)) {
1600 		int len;
1601 
1602 		if (get_user(len, optlen))
1603 			return -EFAULT;
1604 
1605 		lock_sock(sk);
1606 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1607 		release_sock(sk);
1608 		if (err >= 0)
1609 			err = put_user(len, optlen);
1610 		return err;
1611 	}
1612 #endif
1613 	return err;
1614 }
1615 EXPORT_SYMBOL(compat_ip_getsockopt);
1616 #endif
1617