xref: /openbmc/linux/net/ipv4/ip_sockglue.c (revision d8bcaabe)
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 <linux/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 net *net, struct msghdr *msg,
84 				 struct sk_buff *skb)
85 {
86 	unsigned char optbuf[sizeof(struct ip_options) + 40];
87 	struct ip_options *opt = (struct ip_options *)optbuf;
88 
89 	if (IPCB(skb)->opt.optlen == 0)
90 		return;
91 
92 	if (ip_options_echo(net, opt, skb)) {
93 		msg->msg_flags |= MSG_CTRUNC;
94 		return;
95 	}
96 	ip_options_undo(opt);
97 
98 	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
99 }
100 
101 static void ip_cmsg_recv_fragsize(struct msghdr *msg, struct sk_buff *skb)
102 {
103 	int val;
104 
105 	if (IPCB(skb)->frag_max_size == 0)
106 		return;
107 
108 	val = IPCB(skb)->frag_max_size;
109 	put_cmsg(msg, SOL_IP, IP_RECVFRAGSIZE, sizeof(val), &val);
110 }
111 
112 static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
113 				  int tlen, int offset)
114 {
115 	__wsum csum = skb->csum;
116 
117 	if (skb->ip_summed != CHECKSUM_COMPLETE)
118 		return;
119 
120 	if (offset != 0) {
121 		int tend_off = skb_transport_offset(skb) + tlen;
122 		csum = csum_sub(csum, skb_checksum(skb, tend_off, offset, 0));
123 	}
124 
125 	put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum);
126 }
127 
128 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
129 {
130 	char *secdata;
131 	u32 seclen, secid;
132 	int err;
133 
134 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
135 	if (err)
136 		return;
137 
138 	err = security_secid_to_secctx(secid, &secdata, &seclen);
139 	if (err)
140 		return;
141 
142 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
143 	security_release_secctx(secdata, seclen);
144 }
145 
146 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
147 {
148 	struct sockaddr_in sin;
149 	const struct iphdr *iph = ip_hdr(skb);
150 	__be16 *ports = (__be16 *)skb_transport_header(skb);
151 
152 	if (skb_transport_offset(skb) + 4 > (int)skb->len)
153 		return;
154 
155 	/* All current transport protocols have the port numbers in the
156 	 * first four bytes of the transport header and this function is
157 	 * written with this assumption in mind.
158 	 */
159 
160 	sin.sin_family = AF_INET;
161 	sin.sin_addr.s_addr = iph->daddr;
162 	sin.sin_port = ports[1];
163 	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
164 
165 	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
166 }
167 
168 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
169 			 struct sk_buff *skb, int tlen, int offset)
170 {
171 	struct inet_sock *inet = inet_sk(sk);
172 	unsigned int flags = inet->cmsg_flags;
173 
174 	/* Ordered by supposed usage frequency */
175 	if (flags & IP_CMSG_PKTINFO) {
176 		ip_cmsg_recv_pktinfo(msg, skb);
177 
178 		flags &= ~IP_CMSG_PKTINFO;
179 		if (!flags)
180 			return;
181 	}
182 
183 	if (flags & IP_CMSG_TTL) {
184 		ip_cmsg_recv_ttl(msg, skb);
185 
186 		flags &= ~IP_CMSG_TTL;
187 		if (!flags)
188 			return;
189 	}
190 
191 	if (flags & IP_CMSG_TOS) {
192 		ip_cmsg_recv_tos(msg, skb);
193 
194 		flags &= ~IP_CMSG_TOS;
195 		if (!flags)
196 			return;
197 	}
198 
199 	if (flags & IP_CMSG_RECVOPTS) {
200 		ip_cmsg_recv_opts(msg, skb);
201 
202 		flags &= ~IP_CMSG_RECVOPTS;
203 		if (!flags)
204 			return;
205 	}
206 
207 	if (flags & IP_CMSG_RETOPTS) {
208 		ip_cmsg_recv_retopts(sock_net(sk), msg, skb);
209 
210 		flags &= ~IP_CMSG_RETOPTS;
211 		if (!flags)
212 			return;
213 	}
214 
215 	if (flags & IP_CMSG_PASSSEC) {
216 		ip_cmsg_recv_security(msg, skb);
217 
218 		flags &= ~IP_CMSG_PASSSEC;
219 		if (!flags)
220 			return;
221 	}
222 
223 	if (flags & IP_CMSG_ORIGDSTADDR) {
224 		ip_cmsg_recv_dstaddr(msg, skb);
225 
226 		flags &= ~IP_CMSG_ORIGDSTADDR;
227 		if (!flags)
228 			return;
229 	}
230 
231 	if (flags & IP_CMSG_CHECKSUM)
232 		ip_cmsg_recv_checksum(msg, skb, tlen, offset);
233 
234 	if (flags & IP_CMSG_RECVFRAGSIZE)
235 		ip_cmsg_recv_fragsize(msg, skb);
236 }
237 EXPORT_SYMBOL(ip_cmsg_recv_offset);
238 
239 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc,
240 		 bool allow_ipv6)
241 {
242 	int err, val;
243 	struct cmsghdr *cmsg;
244 	struct net *net = sock_net(sk);
245 
246 	for_each_cmsghdr(cmsg, msg) {
247 		if (!CMSG_OK(msg, cmsg))
248 			return -EINVAL;
249 #if IS_ENABLED(CONFIG_IPV6)
250 		if (allow_ipv6 &&
251 		    cmsg->cmsg_level == SOL_IPV6 &&
252 		    cmsg->cmsg_type == IPV6_PKTINFO) {
253 			struct in6_pktinfo *src_info;
254 
255 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info)))
256 				return -EINVAL;
257 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
258 			if (!ipv6_addr_v4mapped(&src_info->ipi6_addr))
259 				return -EINVAL;
260 			ipc->oif = src_info->ipi6_ifindex;
261 			ipc->addr = src_info->ipi6_addr.s6_addr32[3];
262 			continue;
263 		}
264 #endif
265 		if (cmsg->cmsg_level == SOL_SOCKET) {
266 			err = __sock_cmsg_send(sk, msg, cmsg, &ipc->sockc);
267 			if (err)
268 				return err;
269 			continue;
270 		}
271 
272 		if (cmsg->cmsg_level != SOL_IP)
273 			continue;
274 		switch (cmsg->cmsg_type) {
275 		case IP_RETOPTS:
276 			err = cmsg->cmsg_len - sizeof(struct cmsghdr);
277 
278 			/* Our caller is responsible for freeing ipc->opt */
279 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
280 					     err < 40 ? err : 40);
281 			if (err)
282 				return err;
283 			break;
284 		case IP_PKTINFO:
285 		{
286 			struct in_pktinfo *info;
287 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
288 				return -EINVAL;
289 			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
290 			ipc->oif = info->ipi_ifindex;
291 			ipc->addr = info->ipi_spec_dst.s_addr;
292 			break;
293 		}
294 		case IP_TTL:
295 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
296 				return -EINVAL;
297 			val = *(int *)CMSG_DATA(cmsg);
298 			if (val < 1 || val > 255)
299 				return -EINVAL;
300 			ipc->ttl = val;
301 			break;
302 		case IP_TOS:
303 			if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)))
304 				val = *(int *)CMSG_DATA(cmsg);
305 			else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8)))
306 				val = *(u8 *)CMSG_DATA(cmsg);
307 			else
308 				return -EINVAL;
309 			if (val < 0 || val > 255)
310 				return -EINVAL;
311 			ipc->tos = val;
312 			ipc->priority = rt_tos2priority(ipc->tos);
313 			break;
314 
315 		default:
316 			return -EINVAL;
317 		}
318 	}
319 	return 0;
320 }
321 
322 
323 /* Special input handler for packets caught by router alert option.
324    They are selected only by protocol field, and then processed likely
325    local ones; but only if someone wants them! Otherwise, router
326    not running rsvpd will kill RSVP.
327 
328    It is user level problem, what it will make with them.
329    I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
330    but receiver should be enough clever f.e. to forward mtrace requests,
331    sent to multicast group to reach destination designated router.
332  */
333 struct ip_ra_chain __rcu *ip_ra_chain;
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 	for (rap = &ip_ra_chain;
356 	     (ra = rtnl_dereference(*rap)) != NULL;
357 	     rap = &ra->next) {
358 		if (ra->sk == sk) {
359 			if (on) {
360 				kfree(new_ra);
361 				return -EADDRINUSE;
362 			}
363 			/* dont let ip_call_ra_chain() use sk again */
364 			ra->sk = NULL;
365 			RCU_INIT_POINTER(*rap, ra->next);
366 
367 			if (ra->destructor)
368 				ra->destructor(sk);
369 			/*
370 			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
371 			 * period. This guarantee ip_call_ra_chain() dont need
372 			 * to mess with socket refcounts.
373 			 */
374 			ra->saved_sk = sk;
375 			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
376 			return 0;
377 		}
378 	}
379 	if (!new_ra)
380 		return -ENOBUFS;
381 	new_ra->sk = sk;
382 	new_ra->destructor = destructor;
383 
384 	RCU_INIT_POINTER(new_ra->next, ra);
385 	rcu_assign_pointer(*rap, new_ra);
386 	sock_hold(sk);
387 
388 	return 0;
389 }
390 
391 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
392 		   __be16 port, u32 info, u8 *payload)
393 {
394 	struct sock_exterr_skb *serr;
395 
396 	skb = skb_clone(skb, GFP_ATOMIC);
397 	if (!skb)
398 		return;
399 
400 	serr = SKB_EXT_ERR(skb);
401 	serr->ee.ee_errno = err;
402 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
403 	serr->ee.ee_type = icmp_hdr(skb)->type;
404 	serr->ee.ee_code = icmp_hdr(skb)->code;
405 	serr->ee.ee_pad = 0;
406 	serr->ee.ee_info = info;
407 	serr->ee.ee_data = 0;
408 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
409 				   skb_network_header(skb);
410 	serr->port = port;
411 
412 	if (skb_pull(skb, payload - skb->data)) {
413 		skb_reset_transport_header(skb);
414 		if (sock_queue_err_skb(sk, skb) == 0)
415 			return;
416 	}
417 	kfree_skb(skb);
418 }
419 
420 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
421 {
422 	struct inet_sock *inet = inet_sk(sk);
423 	struct sock_exterr_skb *serr;
424 	struct iphdr *iph;
425 	struct sk_buff *skb;
426 
427 	if (!inet->recverr)
428 		return;
429 
430 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
431 	if (!skb)
432 		return;
433 
434 	skb_put(skb, sizeof(struct iphdr));
435 	skb_reset_network_header(skb);
436 	iph = ip_hdr(skb);
437 	iph->daddr = daddr;
438 
439 	serr = SKB_EXT_ERR(skb);
440 	serr->ee.ee_errno = err;
441 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
442 	serr->ee.ee_type = 0;
443 	serr->ee.ee_code = 0;
444 	serr->ee.ee_pad = 0;
445 	serr->ee.ee_info = info;
446 	serr->ee.ee_data = 0;
447 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
448 	serr->port = port;
449 
450 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
451 	skb_reset_transport_header(skb);
452 
453 	if (sock_queue_err_skb(sk, skb))
454 		kfree_skb(skb);
455 }
456 
457 /* For some errors we have valid addr_offset even with zero payload and
458  * zero port. Also, addr_offset should be supported if port is set.
459  */
460 static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
461 {
462 	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
463 	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
464 }
465 
466 /* IPv4 supports cmsg on all imcp errors and some timestamps
467  *
468  * Timestamp code paths do not initialize the fields expected by cmsg:
469  * the PKTINFO fields in skb->cb[]. Fill those in here.
470  */
471 static bool ipv4_datagram_support_cmsg(const struct sock *sk,
472 				       struct sk_buff *skb,
473 				       int ee_origin)
474 {
475 	struct in_pktinfo *info;
476 
477 	if (ee_origin == SO_EE_ORIGIN_ICMP)
478 		return true;
479 
480 	if (ee_origin == SO_EE_ORIGIN_LOCAL)
481 		return false;
482 
483 	/* Support IP_PKTINFO on tstamp packets if requested, to correlate
484 	 * timestamp with egress dev. Not possible for packets without iif
485 	 * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
486 	 */
487 	info = PKTINFO_SKB_CB(skb);
488 	if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) ||
489 	    !info->ipi_ifindex)
490 		return false;
491 
492 	info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
493 	return true;
494 }
495 
496 /*
497  *	Handle MSG_ERRQUEUE
498  */
499 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
500 {
501 	struct sock_exterr_skb *serr;
502 	struct sk_buff *skb;
503 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
504 	struct {
505 		struct sock_extended_err ee;
506 		struct sockaddr_in	 offender;
507 	} errhdr;
508 	int err;
509 	int copied;
510 
511 	WARN_ON_ONCE(sk->sk_family == AF_INET6);
512 
513 	err = -EAGAIN;
514 	skb = sock_dequeue_err_skb(sk);
515 	if (!skb)
516 		goto out;
517 
518 	copied = skb->len;
519 	if (copied > len) {
520 		msg->msg_flags |= MSG_TRUNC;
521 		copied = len;
522 	}
523 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
524 	if (unlikely(err)) {
525 		kfree_skb(skb);
526 		return err;
527 	}
528 	sock_recv_timestamp(msg, sk, skb);
529 
530 	serr = SKB_EXT_ERR(skb);
531 
532 	if (sin && ipv4_datagram_support_addr(serr)) {
533 		sin->sin_family = AF_INET;
534 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
535 						   serr->addr_offset);
536 		sin->sin_port = serr->port;
537 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
538 		*addr_len = sizeof(*sin);
539 	}
540 
541 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
542 	sin = &errhdr.offender;
543 	memset(sin, 0, sizeof(*sin));
544 
545 	if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
546 		sin->sin_family = AF_INET;
547 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
548 		if (inet_sk(sk)->cmsg_flags)
549 			ip_cmsg_recv(msg, skb);
550 	}
551 
552 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
553 
554 	/* Now we could try to dump offended packet options */
555 
556 	msg->msg_flags |= MSG_ERRQUEUE;
557 	err = copied;
558 
559 	consume_skb(skb);
560 out:
561 	return err;
562 }
563 
564 
565 /*
566  *	Socket option code for IP. This is the end of the line after any
567  *	TCP,UDP etc options on an IP socket.
568  */
569 static bool setsockopt_needs_rtnl(int optname)
570 {
571 	switch (optname) {
572 	case IP_ADD_MEMBERSHIP:
573 	case IP_ADD_SOURCE_MEMBERSHIP:
574 	case IP_BLOCK_SOURCE:
575 	case IP_DROP_MEMBERSHIP:
576 	case IP_DROP_SOURCE_MEMBERSHIP:
577 	case IP_MSFILTER:
578 	case IP_UNBLOCK_SOURCE:
579 	case MCAST_BLOCK_SOURCE:
580 	case MCAST_MSFILTER:
581 	case MCAST_JOIN_GROUP:
582 	case MCAST_JOIN_SOURCE_GROUP:
583 	case MCAST_LEAVE_GROUP:
584 	case MCAST_LEAVE_SOURCE_GROUP:
585 	case MCAST_UNBLOCK_SOURCE:
586 	case IP_ROUTER_ALERT:
587 		return true;
588 	}
589 	return false;
590 }
591 
592 static int do_ip_setsockopt(struct sock *sk, int level,
593 			    int optname, char __user *optval, unsigned int optlen)
594 {
595 	struct inet_sock *inet = inet_sk(sk);
596 	struct net *net = sock_net(sk);
597 	int val = 0, err;
598 	bool needs_rtnl = setsockopt_needs_rtnl(optname);
599 
600 	switch (optname) {
601 	case IP_PKTINFO:
602 	case IP_RECVTTL:
603 	case IP_RECVOPTS:
604 	case IP_RECVTOS:
605 	case IP_RETOPTS:
606 	case IP_TOS:
607 	case IP_TTL:
608 	case IP_HDRINCL:
609 	case IP_MTU_DISCOVER:
610 	case IP_RECVERR:
611 	case IP_ROUTER_ALERT:
612 	case IP_FREEBIND:
613 	case IP_PASSSEC:
614 	case IP_TRANSPARENT:
615 	case IP_MINTTL:
616 	case IP_NODEFRAG:
617 	case IP_BIND_ADDRESS_NO_PORT:
618 	case IP_UNICAST_IF:
619 	case IP_MULTICAST_TTL:
620 	case IP_MULTICAST_ALL:
621 	case IP_MULTICAST_LOOP:
622 	case IP_RECVORIGDSTADDR:
623 	case IP_CHECKSUM:
624 	case IP_RECVFRAGSIZE:
625 		if (optlen >= sizeof(int)) {
626 			if (get_user(val, (int __user *) optval))
627 				return -EFAULT;
628 		} else if (optlen >= sizeof(char)) {
629 			unsigned char ucval;
630 
631 			if (get_user(ucval, (unsigned char __user *) optval))
632 				return -EFAULT;
633 			val = (int) ucval;
634 		}
635 	}
636 
637 	/* If optlen==0, it is equivalent to val == 0 */
638 
639 	if (ip_mroute_opt(optname))
640 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
641 
642 	err = 0;
643 	if (needs_rtnl)
644 		rtnl_lock();
645 	lock_sock(sk);
646 
647 	switch (optname) {
648 	case IP_OPTIONS:
649 	{
650 		struct ip_options_rcu *old, *opt = NULL;
651 
652 		if (optlen > 40)
653 			goto e_inval;
654 		err = ip_options_get_from_user(sock_net(sk), &opt,
655 					       optval, optlen);
656 		if (err)
657 			break;
658 		old = rcu_dereference_protected(inet->inet_opt,
659 						lockdep_sock_is_held(sk));
660 		if (inet->is_icsk) {
661 			struct inet_connection_sock *icsk = inet_csk(sk);
662 #if IS_ENABLED(CONFIG_IPV6)
663 			if (sk->sk_family == PF_INET ||
664 			    (!((1 << sk->sk_state) &
665 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
666 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
667 #endif
668 				if (old)
669 					icsk->icsk_ext_hdr_len -= old->opt.optlen;
670 				if (opt)
671 					icsk->icsk_ext_hdr_len += opt->opt.optlen;
672 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
673 #if IS_ENABLED(CONFIG_IPV6)
674 			}
675 #endif
676 		}
677 		rcu_assign_pointer(inet->inet_opt, opt);
678 		if (old)
679 			kfree_rcu(old, rcu);
680 		break;
681 	}
682 	case IP_PKTINFO:
683 		if (val)
684 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
685 		else
686 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
687 		break;
688 	case IP_RECVTTL:
689 		if (val)
690 			inet->cmsg_flags |=  IP_CMSG_TTL;
691 		else
692 			inet->cmsg_flags &= ~IP_CMSG_TTL;
693 		break;
694 	case IP_RECVTOS:
695 		if (val)
696 			inet->cmsg_flags |=  IP_CMSG_TOS;
697 		else
698 			inet->cmsg_flags &= ~IP_CMSG_TOS;
699 		break;
700 	case IP_RECVOPTS:
701 		if (val)
702 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
703 		else
704 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
705 		break;
706 	case IP_RETOPTS:
707 		if (val)
708 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
709 		else
710 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
711 		break;
712 	case IP_PASSSEC:
713 		if (val)
714 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
715 		else
716 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
717 		break;
718 	case IP_RECVORIGDSTADDR:
719 		if (val)
720 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
721 		else
722 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
723 		break;
724 	case IP_CHECKSUM:
725 		if (val) {
726 			if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
727 				inet_inc_convert_csum(sk);
728 				inet->cmsg_flags |= IP_CMSG_CHECKSUM;
729 			}
730 		} else {
731 			if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
732 				inet_dec_convert_csum(sk);
733 				inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
734 			}
735 		}
736 		break;
737 	case IP_RECVFRAGSIZE:
738 		if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
739 			goto e_inval;
740 		if (val)
741 			inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
742 		else
743 			inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
744 		break;
745 	case IP_TOS:	/* This sets both TOS and Precedence */
746 		if (sk->sk_type == SOCK_STREAM) {
747 			val &= ~INET_ECN_MASK;
748 			val |= inet->tos & INET_ECN_MASK;
749 		}
750 		if (inet->tos != val) {
751 			inet->tos = val;
752 			sk->sk_priority = rt_tos2priority(val);
753 			sk_dst_reset(sk);
754 		}
755 		break;
756 	case IP_TTL:
757 		if (optlen < 1)
758 			goto e_inval;
759 		if (val != -1 && (val < 1 || val > 255))
760 			goto e_inval;
761 		inet->uc_ttl = val;
762 		break;
763 	case IP_HDRINCL:
764 		if (sk->sk_type != SOCK_RAW) {
765 			err = -ENOPROTOOPT;
766 			break;
767 		}
768 		inet->hdrincl = val ? 1 : 0;
769 		break;
770 	case IP_NODEFRAG:
771 		if (sk->sk_type != SOCK_RAW) {
772 			err = -ENOPROTOOPT;
773 			break;
774 		}
775 		inet->nodefrag = val ? 1 : 0;
776 		break;
777 	case IP_BIND_ADDRESS_NO_PORT:
778 		inet->bind_address_no_port = val ? 1 : 0;
779 		break;
780 	case IP_MTU_DISCOVER:
781 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
782 			goto e_inval;
783 		inet->pmtudisc = val;
784 		break;
785 	case IP_RECVERR:
786 		inet->recverr = !!val;
787 		if (!val)
788 			skb_queue_purge(&sk->sk_error_queue);
789 		break;
790 	case IP_MULTICAST_TTL:
791 		if (sk->sk_type == SOCK_STREAM)
792 			goto e_inval;
793 		if (optlen < 1)
794 			goto e_inval;
795 		if (val == -1)
796 			val = 1;
797 		if (val < 0 || val > 255)
798 			goto e_inval;
799 		inet->mc_ttl = val;
800 		break;
801 	case IP_MULTICAST_LOOP:
802 		if (optlen < 1)
803 			goto e_inval;
804 		inet->mc_loop = !!val;
805 		break;
806 	case IP_UNICAST_IF:
807 	{
808 		struct net_device *dev = NULL;
809 		int ifindex;
810 
811 		if (optlen != sizeof(int))
812 			goto e_inval;
813 
814 		ifindex = (__force int)ntohl((__force __be32)val);
815 		if (ifindex == 0) {
816 			inet->uc_index = 0;
817 			err = 0;
818 			break;
819 		}
820 
821 		dev = dev_get_by_index(sock_net(sk), ifindex);
822 		err = -EADDRNOTAVAIL;
823 		if (!dev)
824 			break;
825 		dev_put(dev);
826 
827 		err = -EINVAL;
828 		if (sk->sk_bound_dev_if)
829 			break;
830 
831 		inet->uc_index = ifindex;
832 		err = 0;
833 		break;
834 	}
835 	case IP_MULTICAST_IF:
836 	{
837 		struct ip_mreqn mreq;
838 		struct net_device *dev = NULL;
839 		int midx;
840 
841 		if (sk->sk_type == SOCK_STREAM)
842 			goto e_inval;
843 		/*
844 		 *	Check the arguments are allowable
845 		 */
846 
847 		if (optlen < sizeof(struct in_addr))
848 			goto e_inval;
849 
850 		err = -EFAULT;
851 		if (optlen >= sizeof(struct ip_mreqn)) {
852 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
853 				break;
854 		} else {
855 			memset(&mreq, 0, sizeof(mreq));
856 			if (optlen >= sizeof(struct ip_mreq)) {
857 				if (copy_from_user(&mreq, optval,
858 						   sizeof(struct ip_mreq)))
859 					break;
860 			} else if (optlen >= sizeof(struct in_addr)) {
861 				if (copy_from_user(&mreq.imr_address, optval,
862 						   sizeof(struct in_addr)))
863 					break;
864 			}
865 		}
866 
867 		if (!mreq.imr_ifindex) {
868 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
869 				inet->mc_index = 0;
870 				inet->mc_addr  = 0;
871 				err = 0;
872 				break;
873 			}
874 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
875 			if (dev)
876 				mreq.imr_ifindex = dev->ifindex;
877 		} else
878 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
879 
880 
881 		err = -EADDRNOTAVAIL;
882 		if (!dev)
883 			break;
884 
885 		midx = l3mdev_master_ifindex(dev);
886 
887 		dev_put(dev);
888 
889 		err = -EINVAL;
890 		if (sk->sk_bound_dev_if &&
891 		    mreq.imr_ifindex != sk->sk_bound_dev_if &&
892 		    (!midx || midx != sk->sk_bound_dev_if))
893 			break;
894 
895 		inet->mc_index = mreq.imr_ifindex;
896 		inet->mc_addr  = mreq.imr_address.s_addr;
897 		err = 0;
898 		break;
899 	}
900 
901 	case IP_ADD_MEMBERSHIP:
902 	case IP_DROP_MEMBERSHIP:
903 	{
904 		struct ip_mreqn mreq;
905 
906 		err = -EPROTO;
907 		if (inet_sk(sk)->is_icsk)
908 			break;
909 
910 		if (optlen < sizeof(struct ip_mreq))
911 			goto e_inval;
912 		err = -EFAULT;
913 		if (optlen >= sizeof(struct ip_mreqn)) {
914 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
915 				break;
916 		} else {
917 			memset(&mreq, 0, sizeof(mreq));
918 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
919 				break;
920 		}
921 
922 		if (optname == IP_ADD_MEMBERSHIP)
923 			err = ip_mc_join_group(sk, &mreq);
924 		else
925 			err = ip_mc_leave_group(sk, &mreq);
926 		break;
927 	}
928 	case IP_MSFILTER:
929 	{
930 		struct ip_msfilter *msf;
931 
932 		if (optlen < IP_MSFILTER_SIZE(0))
933 			goto e_inval;
934 		if (optlen > sysctl_optmem_max) {
935 			err = -ENOBUFS;
936 			break;
937 		}
938 		msf = memdup_user(optval, optlen);
939 		if (IS_ERR(msf)) {
940 			err = PTR_ERR(msf);
941 			break;
942 		}
943 		/* numsrc >= (1G-4) overflow in 32 bits */
944 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
945 		    msf->imsf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
946 			kfree(msf);
947 			err = -ENOBUFS;
948 			break;
949 		}
950 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
951 			kfree(msf);
952 			err = -EINVAL;
953 			break;
954 		}
955 		err = ip_mc_msfilter(sk, msf, 0);
956 		kfree(msf);
957 		break;
958 	}
959 	case IP_BLOCK_SOURCE:
960 	case IP_UNBLOCK_SOURCE:
961 	case IP_ADD_SOURCE_MEMBERSHIP:
962 	case IP_DROP_SOURCE_MEMBERSHIP:
963 	{
964 		struct ip_mreq_source mreqs;
965 		int omode, add;
966 
967 		if (optlen != sizeof(struct ip_mreq_source))
968 			goto e_inval;
969 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
970 			err = -EFAULT;
971 			break;
972 		}
973 		if (optname == IP_BLOCK_SOURCE) {
974 			omode = MCAST_EXCLUDE;
975 			add = 1;
976 		} else if (optname == IP_UNBLOCK_SOURCE) {
977 			omode = MCAST_EXCLUDE;
978 			add = 0;
979 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
980 			struct ip_mreqn mreq;
981 
982 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
983 			mreq.imr_address.s_addr = mreqs.imr_interface;
984 			mreq.imr_ifindex = 0;
985 			err = ip_mc_join_group(sk, &mreq);
986 			if (err && err != -EADDRINUSE)
987 				break;
988 			omode = MCAST_INCLUDE;
989 			add = 1;
990 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
991 			omode = MCAST_INCLUDE;
992 			add = 0;
993 		}
994 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
995 		break;
996 	}
997 	case MCAST_JOIN_GROUP:
998 	case MCAST_LEAVE_GROUP:
999 	{
1000 		struct group_req greq;
1001 		struct sockaddr_in *psin;
1002 		struct ip_mreqn mreq;
1003 
1004 		if (optlen < sizeof(struct group_req))
1005 			goto e_inval;
1006 		err = -EFAULT;
1007 		if (copy_from_user(&greq, optval, sizeof(greq)))
1008 			break;
1009 		psin = (struct sockaddr_in *)&greq.gr_group;
1010 		if (psin->sin_family != AF_INET)
1011 			goto e_inval;
1012 		memset(&mreq, 0, sizeof(mreq));
1013 		mreq.imr_multiaddr = psin->sin_addr;
1014 		mreq.imr_ifindex = greq.gr_interface;
1015 
1016 		if (optname == MCAST_JOIN_GROUP)
1017 			err = ip_mc_join_group(sk, &mreq);
1018 		else
1019 			err = ip_mc_leave_group(sk, &mreq);
1020 		break;
1021 	}
1022 	case MCAST_JOIN_SOURCE_GROUP:
1023 	case MCAST_LEAVE_SOURCE_GROUP:
1024 	case MCAST_BLOCK_SOURCE:
1025 	case MCAST_UNBLOCK_SOURCE:
1026 	{
1027 		struct group_source_req greqs;
1028 		struct ip_mreq_source mreqs;
1029 		struct sockaddr_in *psin;
1030 		int omode, add;
1031 
1032 		if (optlen != sizeof(struct group_source_req))
1033 			goto e_inval;
1034 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
1035 			err = -EFAULT;
1036 			break;
1037 		}
1038 		if (greqs.gsr_group.ss_family != AF_INET ||
1039 		    greqs.gsr_source.ss_family != AF_INET) {
1040 			err = -EADDRNOTAVAIL;
1041 			break;
1042 		}
1043 		psin = (struct sockaddr_in *)&greqs.gsr_group;
1044 		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
1045 		psin = (struct sockaddr_in *)&greqs.gsr_source;
1046 		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
1047 		mreqs.imr_interface = 0; /* use index for mc_source */
1048 
1049 		if (optname == MCAST_BLOCK_SOURCE) {
1050 			omode = MCAST_EXCLUDE;
1051 			add = 1;
1052 		} else if (optname == MCAST_UNBLOCK_SOURCE) {
1053 			omode = MCAST_EXCLUDE;
1054 			add = 0;
1055 		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
1056 			struct ip_mreqn mreq;
1057 
1058 			psin = (struct sockaddr_in *)&greqs.gsr_group;
1059 			mreq.imr_multiaddr = psin->sin_addr;
1060 			mreq.imr_address.s_addr = 0;
1061 			mreq.imr_ifindex = greqs.gsr_interface;
1062 			err = ip_mc_join_group(sk, &mreq);
1063 			if (err && err != -EADDRINUSE)
1064 				break;
1065 			greqs.gsr_interface = mreq.imr_ifindex;
1066 			omode = MCAST_INCLUDE;
1067 			add = 1;
1068 		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
1069 			omode = MCAST_INCLUDE;
1070 			add = 0;
1071 		}
1072 		err = ip_mc_source(add, omode, sk, &mreqs,
1073 				   greqs.gsr_interface);
1074 		break;
1075 	}
1076 	case MCAST_MSFILTER:
1077 	{
1078 		struct sockaddr_in *psin;
1079 		struct ip_msfilter *msf = NULL;
1080 		struct group_filter *gsf = NULL;
1081 		int msize, i, ifindex;
1082 
1083 		if (optlen < GROUP_FILTER_SIZE(0))
1084 			goto e_inval;
1085 		if (optlen > sysctl_optmem_max) {
1086 			err = -ENOBUFS;
1087 			break;
1088 		}
1089 		gsf = memdup_user(optval, optlen);
1090 		if (IS_ERR(gsf)) {
1091 			err = PTR_ERR(gsf);
1092 			break;
1093 		}
1094 
1095 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
1096 		if (gsf->gf_numsrc >= 0x1ffffff ||
1097 		    gsf->gf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
1098 			err = -ENOBUFS;
1099 			goto mc_msf_out;
1100 		}
1101 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
1102 			err = -EINVAL;
1103 			goto mc_msf_out;
1104 		}
1105 		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
1106 		msf = kmalloc(msize, GFP_KERNEL);
1107 		if (!msf) {
1108 			err = -ENOBUFS;
1109 			goto mc_msf_out;
1110 		}
1111 		ifindex = gsf->gf_interface;
1112 		psin = (struct sockaddr_in *)&gsf->gf_group;
1113 		if (psin->sin_family != AF_INET) {
1114 			err = -EADDRNOTAVAIL;
1115 			goto mc_msf_out;
1116 		}
1117 		msf->imsf_multiaddr = psin->sin_addr.s_addr;
1118 		msf->imsf_interface = 0;
1119 		msf->imsf_fmode = gsf->gf_fmode;
1120 		msf->imsf_numsrc = gsf->gf_numsrc;
1121 		err = -EADDRNOTAVAIL;
1122 		for (i = 0; i < gsf->gf_numsrc; ++i) {
1123 			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
1124 
1125 			if (psin->sin_family != AF_INET)
1126 				goto mc_msf_out;
1127 			msf->imsf_slist[i] = psin->sin_addr.s_addr;
1128 		}
1129 		kfree(gsf);
1130 		gsf = NULL;
1131 
1132 		err = ip_mc_msfilter(sk, msf, ifindex);
1133 mc_msf_out:
1134 		kfree(msf);
1135 		kfree(gsf);
1136 		break;
1137 	}
1138 	case IP_MULTICAST_ALL:
1139 		if (optlen < 1)
1140 			goto e_inval;
1141 		if (val != 0 && val != 1)
1142 			goto e_inval;
1143 		inet->mc_all = val;
1144 		break;
1145 	case IP_ROUTER_ALERT:
1146 		err = ip_ra_control(sk, val ? 1 : 0, NULL);
1147 		break;
1148 
1149 	case IP_FREEBIND:
1150 		if (optlen < 1)
1151 			goto e_inval;
1152 		inet->freebind = !!val;
1153 		break;
1154 
1155 	case IP_IPSEC_POLICY:
1156 	case IP_XFRM_POLICY:
1157 		err = -EPERM;
1158 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1159 			break;
1160 		err = xfrm_user_policy(sk, optname, optval, optlen);
1161 		break;
1162 
1163 	case IP_TRANSPARENT:
1164 		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1165 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1166 			err = -EPERM;
1167 			break;
1168 		}
1169 		if (optlen < 1)
1170 			goto e_inval;
1171 		inet->transparent = !!val;
1172 		break;
1173 
1174 	case IP_MINTTL:
1175 		if (optlen < 1)
1176 			goto e_inval;
1177 		if (val < 0 || val > 255)
1178 			goto e_inval;
1179 		inet->min_ttl = val;
1180 		break;
1181 
1182 	default:
1183 		err = -ENOPROTOOPT;
1184 		break;
1185 	}
1186 	release_sock(sk);
1187 	if (needs_rtnl)
1188 		rtnl_unlock();
1189 	return err;
1190 
1191 e_inval:
1192 	release_sock(sk);
1193 	if (needs_rtnl)
1194 		rtnl_unlock();
1195 	return -EINVAL;
1196 }
1197 
1198 /**
1199  * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1200  * @sk: socket
1201  * @skb: buffer
1202  *
1203  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1204  * destination in skb->cb[] before dst drop.
1205  * This way, receiver doesn't make cache line misses to read rtable.
1206  */
1207 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1208 {
1209 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1210 	bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1211 		       ipv6_sk_rxinfo(sk);
1212 
1213 	if (prepare && skb_rtable(skb)) {
1214 		/* skb->cb is overloaded: prior to this point it is IP{6}CB
1215 		 * which has interface index (iif) as the first member of the
1216 		 * underlying inet{6}_skb_parm struct. This code then overlays
1217 		 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
1218 		 * element so the iif is picked up from the prior IPCB. If iif
1219 		 * is the loopback interface, then return the sending interface
1220 		 * (e.g., process binds socket to eth0 for Tx which is
1221 		 * redirected to loopback in the rtable/dst).
1222 		 */
1223 		struct rtable *rt = skb_rtable(skb);
1224 		bool l3slave = ipv4_l3mdev_skb(IPCB(skb)->flags);
1225 
1226 		if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
1227 			pktinfo->ipi_ifindex = inet_iif(skb);
1228 		else if (l3slave && rt && rt->rt_iif)
1229 			pktinfo->ipi_ifindex = rt->rt_iif;
1230 
1231 		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1232 	} else {
1233 		pktinfo->ipi_ifindex = 0;
1234 		pktinfo->ipi_spec_dst.s_addr = 0;
1235 	}
1236 	skb_dst_drop(skb);
1237 }
1238 
1239 int ip_setsockopt(struct sock *sk, int level,
1240 		int optname, char __user *optval, unsigned int optlen)
1241 {
1242 	int err;
1243 
1244 	if (level != SOL_IP)
1245 		return -ENOPROTOOPT;
1246 
1247 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1248 #ifdef CONFIG_NETFILTER
1249 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1250 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1251 			optname != IP_IPSEC_POLICY &&
1252 			optname != IP_XFRM_POLICY &&
1253 			!ip_mroute_opt(optname)) {
1254 		lock_sock(sk);
1255 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1256 		release_sock(sk);
1257 	}
1258 #endif
1259 	return err;
1260 }
1261 EXPORT_SYMBOL(ip_setsockopt);
1262 
1263 #ifdef CONFIG_COMPAT
1264 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1265 			 char __user *optval, unsigned int optlen)
1266 {
1267 	int err;
1268 
1269 	if (level != SOL_IP)
1270 		return -ENOPROTOOPT;
1271 
1272 	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1273 		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1274 			ip_setsockopt);
1275 
1276 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1277 #ifdef CONFIG_NETFILTER
1278 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1279 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1280 			optname != IP_IPSEC_POLICY &&
1281 			optname != IP_XFRM_POLICY &&
1282 			!ip_mroute_opt(optname)) {
1283 		lock_sock(sk);
1284 		err = compat_nf_setsockopt(sk, PF_INET, optname,
1285 					   optval, optlen);
1286 		release_sock(sk);
1287 	}
1288 #endif
1289 	return err;
1290 }
1291 EXPORT_SYMBOL(compat_ip_setsockopt);
1292 #endif
1293 
1294 /*
1295  *	Get the options. Note for future reference. The GET of IP options gets
1296  *	the _received_ ones. The set sets the _sent_ ones.
1297  */
1298 
1299 static bool getsockopt_needs_rtnl(int optname)
1300 {
1301 	switch (optname) {
1302 	case IP_MSFILTER:
1303 	case MCAST_MSFILTER:
1304 		return true;
1305 	}
1306 	return false;
1307 }
1308 
1309 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1310 			    char __user *optval, int __user *optlen, unsigned int flags)
1311 {
1312 	struct inet_sock *inet = inet_sk(sk);
1313 	bool needs_rtnl = getsockopt_needs_rtnl(optname);
1314 	int val, err = 0;
1315 	int len;
1316 
1317 	if (level != SOL_IP)
1318 		return -EOPNOTSUPP;
1319 
1320 	if (ip_mroute_opt(optname))
1321 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1322 
1323 	if (get_user(len, optlen))
1324 		return -EFAULT;
1325 	if (len < 0)
1326 		return -EINVAL;
1327 
1328 	if (needs_rtnl)
1329 		rtnl_lock();
1330 	lock_sock(sk);
1331 
1332 	switch (optname) {
1333 	case IP_OPTIONS:
1334 	{
1335 		unsigned char optbuf[sizeof(struct ip_options)+40];
1336 		struct ip_options *opt = (struct ip_options *)optbuf;
1337 		struct ip_options_rcu *inet_opt;
1338 
1339 		inet_opt = rcu_dereference_protected(inet->inet_opt,
1340 						     lockdep_sock_is_held(sk));
1341 		opt->optlen = 0;
1342 		if (inet_opt)
1343 			memcpy(optbuf, &inet_opt->opt,
1344 			       sizeof(struct ip_options) +
1345 			       inet_opt->opt.optlen);
1346 		release_sock(sk);
1347 
1348 		if (opt->optlen == 0)
1349 			return put_user(0, optlen);
1350 
1351 		ip_options_undo(opt);
1352 
1353 		len = min_t(unsigned int, len, opt->optlen);
1354 		if (put_user(len, optlen))
1355 			return -EFAULT;
1356 		if (copy_to_user(optval, opt->__data, len))
1357 			return -EFAULT;
1358 		return 0;
1359 	}
1360 	case IP_PKTINFO:
1361 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1362 		break;
1363 	case IP_RECVTTL:
1364 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1365 		break;
1366 	case IP_RECVTOS:
1367 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1368 		break;
1369 	case IP_RECVOPTS:
1370 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1371 		break;
1372 	case IP_RETOPTS:
1373 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1374 		break;
1375 	case IP_PASSSEC:
1376 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1377 		break;
1378 	case IP_RECVORIGDSTADDR:
1379 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1380 		break;
1381 	case IP_CHECKSUM:
1382 		val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1383 		break;
1384 	case IP_RECVFRAGSIZE:
1385 		val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
1386 		break;
1387 	case IP_TOS:
1388 		val = inet->tos;
1389 		break;
1390 	case IP_TTL:
1391 	{
1392 		struct net *net = sock_net(sk);
1393 		val = (inet->uc_ttl == -1 ?
1394 		       net->ipv4.sysctl_ip_default_ttl :
1395 		       inet->uc_ttl);
1396 		break;
1397 	}
1398 	case IP_HDRINCL:
1399 		val = inet->hdrincl;
1400 		break;
1401 	case IP_NODEFRAG:
1402 		val = inet->nodefrag;
1403 		break;
1404 	case IP_BIND_ADDRESS_NO_PORT:
1405 		val = inet->bind_address_no_port;
1406 		break;
1407 	case IP_MTU_DISCOVER:
1408 		val = inet->pmtudisc;
1409 		break;
1410 	case IP_MTU:
1411 	{
1412 		struct dst_entry *dst;
1413 		val = 0;
1414 		dst = sk_dst_get(sk);
1415 		if (dst) {
1416 			val = dst_mtu(dst);
1417 			dst_release(dst);
1418 		}
1419 		if (!val) {
1420 			release_sock(sk);
1421 			return -ENOTCONN;
1422 		}
1423 		break;
1424 	}
1425 	case IP_RECVERR:
1426 		val = inet->recverr;
1427 		break;
1428 	case IP_MULTICAST_TTL:
1429 		val = inet->mc_ttl;
1430 		break;
1431 	case IP_MULTICAST_LOOP:
1432 		val = inet->mc_loop;
1433 		break;
1434 	case IP_UNICAST_IF:
1435 		val = (__force int)htonl((__u32) inet->uc_index);
1436 		break;
1437 	case IP_MULTICAST_IF:
1438 	{
1439 		struct in_addr addr;
1440 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1441 		addr.s_addr = inet->mc_addr;
1442 		release_sock(sk);
1443 
1444 		if (put_user(len, optlen))
1445 			return -EFAULT;
1446 		if (copy_to_user(optval, &addr, len))
1447 			return -EFAULT;
1448 		return 0;
1449 	}
1450 	case IP_MSFILTER:
1451 	{
1452 		struct ip_msfilter msf;
1453 
1454 		if (len < IP_MSFILTER_SIZE(0)) {
1455 			err = -EINVAL;
1456 			goto out;
1457 		}
1458 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1459 			err = -EFAULT;
1460 			goto out;
1461 		}
1462 		err = ip_mc_msfget(sk, &msf,
1463 				   (struct ip_msfilter __user *)optval, optlen);
1464 		goto out;
1465 	}
1466 	case MCAST_MSFILTER:
1467 	{
1468 		struct group_filter gsf;
1469 
1470 		if (len < GROUP_FILTER_SIZE(0)) {
1471 			err = -EINVAL;
1472 			goto out;
1473 		}
1474 		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1475 			err = -EFAULT;
1476 			goto out;
1477 		}
1478 		err = ip_mc_gsfget(sk, &gsf,
1479 				   (struct group_filter __user *)optval,
1480 				   optlen);
1481 		goto out;
1482 	}
1483 	case IP_MULTICAST_ALL:
1484 		val = inet->mc_all;
1485 		break;
1486 	case IP_PKTOPTIONS:
1487 	{
1488 		struct msghdr msg;
1489 
1490 		release_sock(sk);
1491 
1492 		if (sk->sk_type != SOCK_STREAM)
1493 			return -ENOPROTOOPT;
1494 
1495 		msg.msg_control = (__force void *) optval;
1496 		msg.msg_controllen = len;
1497 		msg.msg_flags = flags;
1498 
1499 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1500 			struct in_pktinfo info;
1501 
1502 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1503 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1504 			info.ipi_ifindex = inet->mc_index;
1505 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1506 		}
1507 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1508 			int hlim = inet->mc_ttl;
1509 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1510 		}
1511 		if (inet->cmsg_flags & IP_CMSG_TOS) {
1512 			int tos = inet->rcv_tos;
1513 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1514 		}
1515 		len -= msg.msg_controllen;
1516 		return put_user(len, optlen);
1517 	}
1518 	case IP_FREEBIND:
1519 		val = inet->freebind;
1520 		break;
1521 	case IP_TRANSPARENT:
1522 		val = inet->transparent;
1523 		break;
1524 	case IP_MINTTL:
1525 		val = inet->min_ttl;
1526 		break;
1527 	default:
1528 		release_sock(sk);
1529 		return -ENOPROTOOPT;
1530 	}
1531 	release_sock(sk);
1532 
1533 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1534 		unsigned char ucval = (unsigned char)val;
1535 		len = 1;
1536 		if (put_user(len, optlen))
1537 			return -EFAULT;
1538 		if (copy_to_user(optval, &ucval, 1))
1539 			return -EFAULT;
1540 	} else {
1541 		len = min_t(unsigned int, sizeof(int), len);
1542 		if (put_user(len, optlen))
1543 			return -EFAULT;
1544 		if (copy_to_user(optval, &val, len))
1545 			return -EFAULT;
1546 	}
1547 	return 0;
1548 
1549 out:
1550 	release_sock(sk);
1551 	if (needs_rtnl)
1552 		rtnl_unlock();
1553 	return err;
1554 }
1555 
1556 int ip_getsockopt(struct sock *sk, int level,
1557 		  int optname, char __user *optval, int __user *optlen)
1558 {
1559 	int err;
1560 
1561 	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1562 #ifdef CONFIG_NETFILTER
1563 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1564 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1565 			!ip_mroute_opt(optname)) {
1566 		int len;
1567 
1568 		if (get_user(len, optlen))
1569 			return -EFAULT;
1570 
1571 		lock_sock(sk);
1572 		err = nf_getsockopt(sk, PF_INET, optname, optval,
1573 				&len);
1574 		release_sock(sk);
1575 		if (err >= 0)
1576 			err = put_user(len, optlen);
1577 		return err;
1578 	}
1579 #endif
1580 	return err;
1581 }
1582 EXPORT_SYMBOL(ip_getsockopt);
1583 
1584 #ifdef CONFIG_COMPAT
1585 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1586 			 char __user *optval, int __user *optlen)
1587 {
1588 	int err;
1589 
1590 	if (optname == MCAST_MSFILTER)
1591 		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1592 			ip_getsockopt);
1593 
1594 	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1595 		MSG_CMSG_COMPAT);
1596 
1597 #ifdef CONFIG_NETFILTER
1598 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1599 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1600 			!ip_mroute_opt(optname)) {
1601 		int len;
1602 
1603 		if (get_user(len, optlen))
1604 			return -EFAULT;
1605 
1606 		lock_sock(sk);
1607 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1608 		release_sock(sk);
1609 		if (err >= 0)
1610 			err = put_user(len, optlen);
1611 		return err;
1612 	}
1613 #endif
1614 	return err;
1615 }
1616 EXPORT_SYMBOL(compat_ip_getsockopt);
1617 #endif
1618