xref: /openbmc/linux/net/ipv4/ip_sockglue.c (revision b03afaa8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		The IP to API glue.
8  *
9  * Authors:	see ip.c
10  *
11  * Fixes:
12  *		Many		:	Split from ip.c , see ip.c for history.
13  *		Martin Mares	:	TOS setting fixed.
14  *		Alan Cox	:	Fixed a couple of oopses in Martin's
15  *					TOS tweaks.
16  *		Mike McLagan	:	Routing by source
17  */
18 
19 #include <linux/module.h>
20 #include <linux/types.h>
21 #include <linux/mm.h>
22 #include <linux/skbuff.h>
23 #include <linux/ip.h>
24 #include <linux/icmp.h>
25 #include <linux/inetdevice.h>
26 #include <linux/netdevice.h>
27 #include <linux/slab.h>
28 #include <net/sock.h>
29 #include <net/ip.h>
30 #include <net/icmp.h>
31 #include <net/tcp_states.h>
32 #include <linux/udp.h>
33 #include <linux/igmp.h>
34 #include <linux/netfilter.h>
35 #include <linux/route.h>
36 #include <linux/mroute.h>
37 #include <net/inet_ecn.h>
38 #include <net/route.h>
39 #include <net/xfrm.h>
40 #include <net/compat.h>
41 #include <net/checksum.h>
42 #if IS_ENABLED(CONFIG_IPV6)
43 #include <net/transp_v6.h>
44 #endif
45 #include <net/ip_fib.h>
46 
47 #include <linux/errqueue.h>
48 #include <linux/uaccess.h>
49 
50 #include <linux/bpfilter.h>
51 
52 /*
53  *	SOL_IP control messages.
54  */
55 
56 static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
57 {
58 	struct in_pktinfo info = *PKTINFO_SKB_CB(skb);
59 
60 	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
61 
62 	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
63 }
64 
65 static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
66 {
67 	int ttl = ip_hdr(skb)->ttl;
68 	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
69 }
70 
71 static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
72 {
73 	put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
74 }
75 
76 static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
77 {
78 	if (IPCB(skb)->opt.optlen == 0)
79 		return;
80 
81 	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
82 		 ip_hdr(skb) + 1);
83 }
84 
85 
86 static void ip_cmsg_recv_retopts(struct net *net, struct msghdr *msg,
87 				 struct sk_buff *skb)
88 {
89 	unsigned char optbuf[sizeof(struct ip_options) + 40];
90 	struct ip_options *opt = (struct ip_options *)optbuf;
91 
92 	if (IPCB(skb)->opt.optlen == 0)
93 		return;
94 
95 	if (ip_options_echo(net, opt, skb)) {
96 		msg->msg_flags |= MSG_CTRUNC;
97 		return;
98 	}
99 	ip_options_undo(opt);
100 
101 	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
102 }
103 
104 static void ip_cmsg_recv_fragsize(struct msghdr *msg, struct sk_buff *skb)
105 {
106 	int val;
107 
108 	if (IPCB(skb)->frag_max_size == 0)
109 		return;
110 
111 	val = IPCB(skb)->frag_max_size;
112 	put_cmsg(msg, SOL_IP, IP_RECVFRAGSIZE, sizeof(val), &val);
113 }
114 
115 static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
116 				  int tlen, int offset)
117 {
118 	__wsum csum = skb->csum;
119 
120 	if (skb->ip_summed != CHECKSUM_COMPLETE)
121 		return;
122 
123 	if (offset != 0) {
124 		int tend_off = skb_transport_offset(skb) + tlen;
125 		csum = csum_sub(csum, skb_checksum(skb, tend_off, offset, 0));
126 	}
127 
128 	put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum);
129 }
130 
131 static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
132 {
133 	char *secdata;
134 	u32 seclen, secid;
135 	int err;
136 
137 	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
138 	if (err)
139 		return;
140 
141 	err = security_secid_to_secctx(secid, &secdata, &seclen);
142 	if (err)
143 		return;
144 
145 	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
146 	security_release_secctx(secdata, seclen);
147 }
148 
149 static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
150 {
151 	__be16 _ports[2], *ports;
152 	struct sockaddr_in sin;
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 	ports = skb_header_pointer(skb, skb_transport_offset(skb),
159 				   sizeof(_ports), &_ports);
160 	if (!ports)
161 		return;
162 
163 	sin.sin_family = AF_INET;
164 	sin.sin_addr.s_addr = ip_hdr(skb)->daddr;
165 	sin.sin_port = ports[1];
166 	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
167 
168 	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
169 }
170 
171 void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
172 			 struct sk_buff *skb, int tlen, int offset)
173 {
174 	struct inet_sock *inet = inet_sk(sk);
175 	unsigned int flags = inet->cmsg_flags;
176 
177 	/* Ordered by supposed usage frequency */
178 	if (flags & IP_CMSG_PKTINFO) {
179 		ip_cmsg_recv_pktinfo(msg, skb);
180 
181 		flags &= ~IP_CMSG_PKTINFO;
182 		if (!flags)
183 			return;
184 	}
185 
186 	if (flags & IP_CMSG_TTL) {
187 		ip_cmsg_recv_ttl(msg, skb);
188 
189 		flags &= ~IP_CMSG_TTL;
190 		if (!flags)
191 			return;
192 	}
193 
194 	if (flags & IP_CMSG_TOS) {
195 		ip_cmsg_recv_tos(msg, skb);
196 
197 		flags &= ~IP_CMSG_TOS;
198 		if (!flags)
199 			return;
200 	}
201 
202 	if (flags & IP_CMSG_RECVOPTS) {
203 		ip_cmsg_recv_opts(msg, skb);
204 
205 		flags &= ~IP_CMSG_RECVOPTS;
206 		if (!flags)
207 			return;
208 	}
209 
210 	if (flags & IP_CMSG_RETOPTS) {
211 		ip_cmsg_recv_retopts(sock_net(sk), msg, skb);
212 
213 		flags &= ~IP_CMSG_RETOPTS;
214 		if (!flags)
215 			return;
216 	}
217 
218 	if (flags & IP_CMSG_PASSSEC) {
219 		ip_cmsg_recv_security(msg, skb);
220 
221 		flags &= ~IP_CMSG_PASSSEC;
222 		if (!flags)
223 			return;
224 	}
225 
226 	if (flags & IP_CMSG_ORIGDSTADDR) {
227 		ip_cmsg_recv_dstaddr(msg, skb);
228 
229 		flags &= ~IP_CMSG_ORIGDSTADDR;
230 		if (!flags)
231 			return;
232 	}
233 
234 	if (flags & IP_CMSG_CHECKSUM)
235 		ip_cmsg_recv_checksum(msg, skb, tlen, offset);
236 
237 	if (flags & IP_CMSG_RECVFRAGSIZE)
238 		ip_cmsg_recv_fragsize(msg, skb);
239 }
240 EXPORT_SYMBOL(ip_cmsg_recv_offset);
241 
242 int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc,
243 		 bool allow_ipv6)
244 {
245 	int err, val;
246 	struct cmsghdr *cmsg;
247 	struct net *net = sock_net(sk);
248 
249 	for_each_cmsghdr(cmsg, msg) {
250 		if (!CMSG_OK(msg, cmsg))
251 			return -EINVAL;
252 #if IS_ENABLED(CONFIG_IPV6)
253 		if (allow_ipv6 &&
254 		    cmsg->cmsg_level == SOL_IPV6 &&
255 		    cmsg->cmsg_type == IPV6_PKTINFO) {
256 			struct in6_pktinfo *src_info;
257 
258 			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info)))
259 				return -EINVAL;
260 			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
261 			if (!ipv6_addr_v4mapped(&src_info->ipi6_addr))
262 				return -EINVAL;
263 			if (src_info->ipi6_ifindex)
264 				ipc->oif = src_info->ipi6_ifindex;
265 			ipc->addr = src_info->ipi6_addr.s6_addr32[3];
266 			continue;
267 		}
268 #endif
269 		if (cmsg->cmsg_level == SOL_SOCKET) {
270 			err = __sock_cmsg_send(sk, msg, cmsg, &ipc->sockc);
271 			if (err)
272 				return err;
273 			continue;
274 		}
275 
276 		if (cmsg->cmsg_level != SOL_IP)
277 			continue;
278 		switch (cmsg->cmsg_type) {
279 		case IP_RETOPTS:
280 			err = cmsg->cmsg_len - sizeof(struct cmsghdr);
281 
282 			/* Our caller is responsible for freeing ipc->opt */
283 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
284 					     err < 40 ? err : 40);
285 			if (err)
286 				return err;
287 			break;
288 		case IP_PKTINFO:
289 		{
290 			struct in_pktinfo *info;
291 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
292 				return -EINVAL;
293 			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
294 			if (info->ipi_ifindex)
295 				ipc->oif = info->ipi_ifindex;
296 			ipc->addr = info->ipi_spec_dst.s_addr;
297 			break;
298 		}
299 		case IP_TTL:
300 			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
301 				return -EINVAL;
302 			val = *(int *)CMSG_DATA(cmsg);
303 			if (val < 1 || val > 255)
304 				return -EINVAL;
305 			ipc->ttl = val;
306 			break;
307 		case IP_TOS:
308 			if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)))
309 				val = *(int *)CMSG_DATA(cmsg);
310 			else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8)))
311 				val = *(u8 *)CMSG_DATA(cmsg);
312 			else
313 				return -EINVAL;
314 			if (val < 0 || val > 255)
315 				return -EINVAL;
316 			ipc->tos = val;
317 			ipc->priority = rt_tos2priority(ipc->tos);
318 			break;
319 
320 		default:
321 			return -EINVAL;
322 		}
323 	}
324 	return 0;
325 }
326 
327 static void ip_ra_destroy_rcu(struct rcu_head *head)
328 {
329 	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
330 
331 	sock_put(ra->saved_sk);
332 	kfree(ra);
333 }
334 
335 int ip_ra_control(struct sock *sk, unsigned char on,
336 		  void (*destructor)(struct sock *))
337 {
338 	struct ip_ra_chain *ra, *new_ra;
339 	struct ip_ra_chain __rcu **rap;
340 	struct net *net = sock_net(sk);
341 
342 	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
343 		return -EINVAL;
344 
345 	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
346 	if (on && !new_ra)
347 		return -ENOMEM;
348 
349 	mutex_lock(&net->ipv4.ra_mutex);
350 	for (rap = &net->ipv4.ra_chain;
351 	     (ra = rcu_dereference_protected(*rap,
352 			lockdep_is_held(&net->ipv4.ra_mutex))) != NULL;
353 	     rap = &ra->next) {
354 		if (ra->sk == sk) {
355 			if (on) {
356 				mutex_unlock(&net->ipv4.ra_mutex);
357 				kfree(new_ra);
358 				return -EADDRINUSE;
359 			}
360 			/* dont let ip_call_ra_chain() use sk again */
361 			ra->sk = NULL;
362 			RCU_INIT_POINTER(*rap, ra->next);
363 			mutex_unlock(&net->ipv4.ra_mutex);
364 
365 			if (ra->destructor)
366 				ra->destructor(sk);
367 			/*
368 			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
369 			 * period. This guarantee ip_call_ra_chain() dont need
370 			 * to mess with socket refcounts.
371 			 */
372 			ra->saved_sk = sk;
373 			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
374 			return 0;
375 		}
376 	}
377 	if (!new_ra) {
378 		mutex_unlock(&net->ipv4.ra_mutex);
379 		return -ENOBUFS;
380 	}
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 	mutex_unlock(&net->ipv4.ra_mutex);
388 
389 	return 0;
390 }
391 
392 void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
393 		   __be16 port, u32 info, u8 *payload)
394 {
395 	struct sock_exterr_skb *serr;
396 
397 	skb = skb_clone(skb, GFP_ATOMIC);
398 	if (!skb)
399 		return;
400 
401 	serr = SKB_EXT_ERR(skb);
402 	serr->ee.ee_errno = err;
403 	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
404 	serr->ee.ee_type = icmp_hdr(skb)->type;
405 	serr->ee.ee_code = icmp_hdr(skb)->code;
406 	serr->ee.ee_pad = 0;
407 	serr->ee.ee_info = info;
408 	serr->ee.ee_data = 0;
409 	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
410 				   skb_network_header(skb);
411 	serr->port = port;
412 
413 	if (skb_pull(skb, payload - skb->data)) {
414 		if (inet_sk(sk)->recverr_rfc4884)
415 			ip_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
416 
417 		skb_reset_transport_header(skb);
418 		if (sock_queue_err_skb(sk, skb) == 0)
419 			return;
420 	}
421 	kfree_skb(skb);
422 }
423 
424 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
425 {
426 	struct inet_sock *inet = inet_sk(sk);
427 	struct sock_exterr_skb *serr;
428 	struct iphdr *iph;
429 	struct sk_buff *skb;
430 
431 	if (!inet->recverr)
432 		return;
433 
434 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
435 	if (!skb)
436 		return;
437 
438 	skb_put(skb, sizeof(struct iphdr));
439 	skb_reset_network_header(skb);
440 	iph = ip_hdr(skb);
441 	iph->daddr = daddr;
442 
443 	serr = SKB_EXT_ERR(skb);
444 	serr->ee.ee_errno = err;
445 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
446 	serr->ee.ee_type = 0;
447 	serr->ee.ee_code = 0;
448 	serr->ee.ee_pad = 0;
449 	serr->ee.ee_info = info;
450 	serr->ee.ee_data = 0;
451 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
452 	serr->port = port;
453 
454 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
455 	skb_reset_transport_header(skb);
456 
457 	if (sock_queue_err_skb(sk, skb))
458 		kfree_skb(skb);
459 }
460 
461 /* For some errors we have valid addr_offset even with zero payload and
462  * zero port. Also, addr_offset should be supported if port is set.
463  */
464 static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
465 {
466 	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
467 	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
468 }
469 
470 /* IPv4 supports cmsg on all imcp errors and some timestamps
471  *
472  * Timestamp code paths do not initialize the fields expected by cmsg:
473  * the PKTINFO fields in skb->cb[]. Fill those in here.
474  */
475 static bool ipv4_datagram_support_cmsg(const struct sock *sk,
476 				       struct sk_buff *skb,
477 				       int ee_origin)
478 {
479 	struct in_pktinfo *info;
480 
481 	if (ee_origin == SO_EE_ORIGIN_ICMP)
482 		return true;
483 
484 	if (ee_origin == SO_EE_ORIGIN_LOCAL)
485 		return false;
486 
487 	/* Support IP_PKTINFO on tstamp packets if requested, to correlate
488 	 * timestamp with egress dev. Not possible for packets without iif
489 	 * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
490 	 */
491 	info = PKTINFO_SKB_CB(skb);
492 	if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) ||
493 	    !info->ipi_ifindex)
494 		return false;
495 
496 	info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
497 	return true;
498 }
499 
500 /*
501  *	Handle MSG_ERRQUEUE
502  */
503 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
504 {
505 	struct sock_exterr_skb *serr;
506 	struct sk_buff *skb;
507 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
508 	struct {
509 		struct sock_extended_err ee;
510 		struct sockaddr_in	 offender;
511 	} errhdr;
512 	int err;
513 	int copied;
514 
515 	err = -EAGAIN;
516 	skb = sock_dequeue_err_skb(sk);
517 	if (!skb)
518 		goto out;
519 
520 	copied = skb->len;
521 	if (copied > len) {
522 		msg->msg_flags |= MSG_TRUNC;
523 		copied = len;
524 	}
525 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
526 	if (unlikely(err)) {
527 		kfree_skb(skb);
528 		return err;
529 	}
530 	sock_recv_timestamp(msg, sk, skb);
531 
532 	serr = SKB_EXT_ERR(skb);
533 
534 	if (sin && ipv4_datagram_support_addr(serr)) {
535 		sin->sin_family = AF_INET;
536 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
537 						   serr->addr_offset);
538 		sin->sin_port = serr->port;
539 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
540 		*addr_len = sizeof(*sin);
541 	}
542 
543 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
544 	sin = &errhdr.offender;
545 	memset(sin, 0, sizeof(*sin));
546 
547 	if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
548 		sin->sin_family = AF_INET;
549 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
550 		if (inet_sk(sk)->cmsg_flags)
551 			ip_cmsg_recv(msg, skb);
552 	}
553 
554 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
555 
556 	/* Now we could try to dump offended packet options */
557 
558 	msg->msg_flags |= MSG_ERRQUEUE;
559 	err = copied;
560 
561 	consume_skb(skb);
562 out:
563 	return err;
564 }
565 
566 static void __ip_sock_set_tos(struct sock *sk, int val)
567 {
568 	if (sk->sk_type == SOCK_STREAM) {
569 		val &= ~INET_ECN_MASK;
570 		val |= inet_sk(sk)->tos & INET_ECN_MASK;
571 	}
572 	if (inet_sk(sk)->tos != val) {
573 		inet_sk(sk)->tos = val;
574 		sk->sk_priority = rt_tos2priority(val);
575 		sk_dst_reset(sk);
576 	}
577 }
578 
579 void ip_sock_set_tos(struct sock *sk, int val)
580 {
581 	lock_sock(sk);
582 	__ip_sock_set_tos(sk, val);
583 	release_sock(sk);
584 }
585 EXPORT_SYMBOL(ip_sock_set_tos);
586 
587 void ip_sock_set_freebind(struct sock *sk)
588 {
589 	lock_sock(sk);
590 	inet_sk(sk)->freebind = true;
591 	release_sock(sk);
592 }
593 EXPORT_SYMBOL(ip_sock_set_freebind);
594 
595 void ip_sock_set_recverr(struct sock *sk)
596 {
597 	lock_sock(sk);
598 	inet_sk(sk)->recverr = true;
599 	release_sock(sk);
600 }
601 EXPORT_SYMBOL(ip_sock_set_recverr);
602 
603 int ip_sock_set_mtu_discover(struct sock *sk, int val)
604 {
605 	if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
606 		return -EINVAL;
607 	lock_sock(sk);
608 	inet_sk(sk)->pmtudisc = val;
609 	release_sock(sk);
610 	return 0;
611 }
612 EXPORT_SYMBOL(ip_sock_set_mtu_discover);
613 
614 void ip_sock_set_pktinfo(struct sock *sk)
615 {
616 	lock_sock(sk);
617 	inet_sk(sk)->cmsg_flags |= IP_CMSG_PKTINFO;
618 	release_sock(sk);
619 }
620 EXPORT_SYMBOL(ip_sock_set_pktinfo);
621 
622 /*
623  *	Socket option code for IP. This is the end of the line after any
624  *	TCP,UDP etc options on an IP socket.
625  */
626 static bool setsockopt_needs_rtnl(int optname)
627 {
628 	switch (optname) {
629 	case IP_ADD_MEMBERSHIP:
630 	case IP_ADD_SOURCE_MEMBERSHIP:
631 	case IP_BLOCK_SOURCE:
632 	case IP_DROP_MEMBERSHIP:
633 	case IP_DROP_SOURCE_MEMBERSHIP:
634 	case IP_MSFILTER:
635 	case IP_UNBLOCK_SOURCE:
636 	case MCAST_BLOCK_SOURCE:
637 	case MCAST_MSFILTER:
638 	case MCAST_JOIN_GROUP:
639 	case MCAST_JOIN_SOURCE_GROUP:
640 	case MCAST_LEAVE_GROUP:
641 	case MCAST_LEAVE_SOURCE_GROUP:
642 	case MCAST_UNBLOCK_SOURCE:
643 		return true;
644 	}
645 	return false;
646 }
647 
648 static int set_mcast_msfilter(struct sock *sk, int ifindex,
649 			      int numsrc, int fmode,
650 			      struct sockaddr_storage *group,
651 			      struct sockaddr_storage *list)
652 {
653 	int msize = IP_MSFILTER_SIZE(numsrc);
654 	struct ip_msfilter *msf;
655 	struct sockaddr_in *psin;
656 	int err, i;
657 
658 	msf = kmalloc(msize, GFP_KERNEL);
659 	if (!msf)
660 		return -ENOBUFS;
661 
662 	psin = (struct sockaddr_in *)group;
663 	if (psin->sin_family != AF_INET)
664 		goto Eaddrnotavail;
665 	msf->imsf_multiaddr = psin->sin_addr.s_addr;
666 	msf->imsf_interface = 0;
667 	msf->imsf_fmode = fmode;
668 	msf->imsf_numsrc = numsrc;
669 	for (i = 0; i < numsrc; ++i) {
670 		psin = (struct sockaddr_in *)&list[i];
671 
672 		if (psin->sin_family != AF_INET)
673 			goto Eaddrnotavail;
674 		msf->imsf_slist[i] = psin->sin_addr.s_addr;
675 	}
676 	err = ip_mc_msfilter(sk, msf, ifindex);
677 	kfree(msf);
678 	return err;
679 
680 Eaddrnotavail:
681 	kfree(msf);
682 	return -EADDRNOTAVAIL;
683 }
684 
685 static int copy_group_source_from_user(struct group_source_req *greqs,
686 		void __user *optval, int optlen)
687 {
688 	if (in_compat_syscall()) {
689 		struct compat_group_source_req gr32;
690 
691 		if (optlen != sizeof(gr32))
692 			return -EINVAL;
693 		if (copy_from_user(&gr32, optval, sizeof(gr32)))
694 			return -EFAULT;
695 		greqs->gsr_interface = gr32.gsr_interface;
696 		greqs->gsr_group = gr32.gsr_group;
697 		greqs->gsr_source = gr32.gsr_source;
698 	} else {
699 		if (optlen != sizeof(*greqs))
700 			return -EINVAL;
701 		if (copy_from_user(greqs, optval, sizeof(*greqs)))
702 			return -EFAULT;
703 	}
704 
705 	return 0;
706 }
707 
708 static int do_mcast_group_source(struct sock *sk, int optname,
709 		void __user *optval, int optlen)
710 {
711 	struct group_source_req greqs;
712 	struct ip_mreq_source mreqs;
713 	struct sockaddr_in *psin;
714 	int omode, add, err;
715 
716 	err = copy_group_source_from_user(&greqs, optval, optlen);
717 	if (err)
718 		return err;
719 
720 	if (greqs.gsr_group.ss_family != AF_INET ||
721 	    greqs.gsr_source.ss_family != AF_INET)
722 		return -EADDRNOTAVAIL;
723 
724 	psin = (struct sockaddr_in *)&greqs.gsr_group;
725 	mreqs.imr_multiaddr = psin->sin_addr.s_addr;
726 	psin = (struct sockaddr_in *)&greqs.gsr_source;
727 	mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
728 	mreqs.imr_interface = 0; /* use index for mc_source */
729 
730 	if (optname == MCAST_BLOCK_SOURCE) {
731 		omode = MCAST_EXCLUDE;
732 		add = 1;
733 	} else if (optname == MCAST_UNBLOCK_SOURCE) {
734 		omode = MCAST_EXCLUDE;
735 		add = 0;
736 	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
737 		struct ip_mreqn mreq;
738 
739 		psin = (struct sockaddr_in *)&greqs.gsr_group;
740 		mreq.imr_multiaddr = psin->sin_addr;
741 		mreq.imr_address.s_addr = 0;
742 		mreq.imr_ifindex = greqs.gsr_interface;
743 		err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
744 		if (err && err != -EADDRINUSE)
745 			return err;
746 		greqs.gsr_interface = mreq.imr_ifindex;
747 		omode = MCAST_INCLUDE;
748 		add = 1;
749 	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
750 		omode = MCAST_INCLUDE;
751 		add = 0;
752 	}
753 	return ip_mc_source(add, omode, sk, &mreqs, greqs.gsr_interface);
754 }
755 
756 static int ip_set_mcast_msfilter(struct sock *sk, void __user *optval,
757 		int optlen)
758 {
759 	struct group_filter *gsf = NULL;
760 	int err;
761 
762 	if (optlen < GROUP_FILTER_SIZE(0))
763 		return -EINVAL;
764 	if (optlen > sysctl_optmem_max)
765 		return -ENOBUFS;
766 
767 	gsf = memdup_user(optval, optlen);
768 	if (IS_ERR(gsf))
769 		return PTR_ERR(gsf);
770 
771 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
772 	err = -ENOBUFS;
773 	if (gsf->gf_numsrc >= 0x1ffffff ||
774 	    gsf->gf_numsrc > sock_net(sk)->ipv4.sysctl_igmp_max_msf)
775 		goto out_free_gsf;
776 
777 	err = -EINVAL;
778 	if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen)
779 		goto out_free_gsf;
780 
781 	err = set_mcast_msfilter(sk, gsf->gf_interface, gsf->gf_numsrc,
782 				 gsf->gf_fmode, &gsf->gf_group, gsf->gf_slist);
783 out_free_gsf:
784 	kfree(gsf);
785 	return err;
786 }
787 
788 static int compat_ip_set_mcast_msfilter(struct sock *sk, void __user *optval,
789 		int optlen)
790 {
791 	const int size0 = offsetof(struct compat_group_filter, gf_slist);
792 	struct compat_group_filter *gf32;
793 	unsigned int n;
794 	void *p;
795 	int err;
796 
797 	if (optlen < size0)
798 		return -EINVAL;
799 	if (optlen > sysctl_optmem_max - 4)
800 		return -ENOBUFS;
801 
802 	p = kmalloc(optlen + 4, GFP_KERNEL);
803 	if (!p)
804 		return -ENOMEM;
805 	gf32 = p + 4; /* we want ->gf_group and ->gf_slist aligned */
806 
807 	err = -EFAULT;
808 	if (copy_from_user(gf32, optval, optlen))
809 		goto out_free_gsf;
810 
811 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
812 	n = gf32->gf_numsrc;
813 	err = -ENOBUFS;
814 	if (n >= 0x1ffffff)
815 		goto out_free_gsf;
816 
817 	err = -EINVAL;
818 	if (offsetof(struct compat_group_filter, gf_slist[n]) > optlen)
819 		goto out_free_gsf;
820 
821 	/* numsrc >= (4G-140)/128 overflow in 32 bits */
822 	err = -ENOBUFS;
823 	if (n > sock_net(sk)->ipv4.sysctl_igmp_max_msf)
824 		goto out_free_gsf;
825 	err = set_mcast_msfilter(sk, gf32->gf_interface, n, gf32->gf_fmode,
826 				 &gf32->gf_group, gf32->gf_slist);
827 out_free_gsf:
828 	kfree(p);
829 	return err;
830 }
831 
832 static int ip_mcast_join_leave(struct sock *sk, int optname,
833 		void __user *optval, int optlen)
834 {
835 	struct ip_mreqn mreq = { };
836 	struct sockaddr_in *psin;
837 	struct group_req greq;
838 
839 	if (optlen < sizeof(struct group_req))
840 		return -EINVAL;
841 	if (copy_from_user(&greq, optval, sizeof(greq)))
842 		return -EFAULT;
843 
844 	psin = (struct sockaddr_in *)&greq.gr_group;
845 	if (psin->sin_family != AF_INET)
846 		return -EINVAL;
847 	mreq.imr_multiaddr = psin->sin_addr;
848 	mreq.imr_ifindex = greq.gr_interface;
849 	if (optname == MCAST_JOIN_GROUP)
850 		return ip_mc_join_group(sk, &mreq);
851 	return ip_mc_leave_group(sk, &mreq);
852 }
853 
854 static int compat_ip_mcast_join_leave(struct sock *sk, int optname,
855 		void __user *optval, int optlen)
856 {
857 	struct compat_group_req greq;
858 	struct ip_mreqn mreq = { };
859 	struct sockaddr_in *psin;
860 
861 	if (optlen < sizeof(struct compat_group_req))
862 		return -EINVAL;
863 	if (copy_from_user(&greq, optval, sizeof(greq)))
864 		return -EFAULT;
865 
866 	psin = (struct sockaddr_in *)&greq.gr_group;
867 	if (psin->sin_family != AF_INET)
868 		return -EINVAL;
869 	mreq.imr_multiaddr = psin->sin_addr;
870 	mreq.imr_ifindex = greq.gr_interface;
871 
872 	if (optname == MCAST_JOIN_GROUP)
873 		return ip_mc_join_group(sk, &mreq);
874 	return ip_mc_leave_group(sk, &mreq);
875 }
876 
877 static int do_ip_setsockopt(struct sock *sk, int level,
878 			    int optname, char __user *optval, unsigned int optlen)
879 {
880 	struct inet_sock *inet = inet_sk(sk);
881 	struct net *net = sock_net(sk);
882 	int val = 0, err;
883 	bool needs_rtnl = setsockopt_needs_rtnl(optname);
884 
885 	switch (optname) {
886 	case IP_PKTINFO:
887 	case IP_RECVTTL:
888 	case IP_RECVOPTS:
889 	case IP_RECVTOS:
890 	case IP_RETOPTS:
891 	case IP_TOS:
892 	case IP_TTL:
893 	case IP_HDRINCL:
894 	case IP_MTU_DISCOVER:
895 	case IP_RECVERR:
896 	case IP_ROUTER_ALERT:
897 	case IP_FREEBIND:
898 	case IP_PASSSEC:
899 	case IP_TRANSPARENT:
900 	case IP_MINTTL:
901 	case IP_NODEFRAG:
902 	case IP_BIND_ADDRESS_NO_PORT:
903 	case IP_UNICAST_IF:
904 	case IP_MULTICAST_TTL:
905 	case IP_MULTICAST_ALL:
906 	case IP_MULTICAST_LOOP:
907 	case IP_RECVORIGDSTADDR:
908 	case IP_CHECKSUM:
909 	case IP_RECVFRAGSIZE:
910 	case IP_RECVERR_RFC4884:
911 		if (optlen >= sizeof(int)) {
912 			if (get_user(val, (int __user *) optval))
913 				return -EFAULT;
914 		} else if (optlen >= sizeof(char)) {
915 			unsigned char ucval;
916 
917 			if (get_user(ucval, (unsigned char __user *) optval))
918 				return -EFAULT;
919 			val = (int) ucval;
920 		}
921 	}
922 
923 	/* If optlen==0, it is equivalent to val == 0 */
924 
925 	if (optname == IP_ROUTER_ALERT)
926 		return ip_ra_control(sk, val ? 1 : 0, NULL);
927 	if (ip_mroute_opt(optname))
928 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
929 
930 	err = 0;
931 	if (needs_rtnl)
932 		rtnl_lock();
933 	lock_sock(sk);
934 
935 	switch (optname) {
936 	case IP_OPTIONS:
937 	{
938 		struct ip_options_rcu *old, *opt = NULL;
939 
940 		if (optlen > 40)
941 			goto e_inval;
942 		err = ip_options_get_from_user(sock_net(sk), &opt,
943 					       optval, optlen);
944 		if (err)
945 			break;
946 		old = rcu_dereference_protected(inet->inet_opt,
947 						lockdep_sock_is_held(sk));
948 		if (inet->is_icsk) {
949 			struct inet_connection_sock *icsk = inet_csk(sk);
950 #if IS_ENABLED(CONFIG_IPV6)
951 			if (sk->sk_family == PF_INET ||
952 			    (!((1 << sk->sk_state) &
953 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
954 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
955 #endif
956 				if (old)
957 					icsk->icsk_ext_hdr_len -= old->opt.optlen;
958 				if (opt)
959 					icsk->icsk_ext_hdr_len += opt->opt.optlen;
960 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
961 #if IS_ENABLED(CONFIG_IPV6)
962 			}
963 #endif
964 		}
965 		rcu_assign_pointer(inet->inet_opt, opt);
966 		if (old)
967 			kfree_rcu(old, rcu);
968 		break;
969 	}
970 	case IP_PKTINFO:
971 		if (val)
972 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
973 		else
974 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
975 		break;
976 	case IP_RECVTTL:
977 		if (val)
978 			inet->cmsg_flags |=  IP_CMSG_TTL;
979 		else
980 			inet->cmsg_flags &= ~IP_CMSG_TTL;
981 		break;
982 	case IP_RECVTOS:
983 		if (val)
984 			inet->cmsg_flags |=  IP_CMSG_TOS;
985 		else
986 			inet->cmsg_flags &= ~IP_CMSG_TOS;
987 		break;
988 	case IP_RECVOPTS:
989 		if (val)
990 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
991 		else
992 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
993 		break;
994 	case IP_RETOPTS:
995 		if (val)
996 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
997 		else
998 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
999 		break;
1000 	case IP_PASSSEC:
1001 		if (val)
1002 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
1003 		else
1004 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
1005 		break;
1006 	case IP_RECVORIGDSTADDR:
1007 		if (val)
1008 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
1009 		else
1010 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
1011 		break;
1012 	case IP_CHECKSUM:
1013 		if (val) {
1014 			if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
1015 				inet_inc_convert_csum(sk);
1016 				inet->cmsg_flags |= IP_CMSG_CHECKSUM;
1017 			}
1018 		} else {
1019 			if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
1020 				inet_dec_convert_csum(sk);
1021 				inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
1022 			}
1023 		}
1024 		break;
1025 	case IP_RECVFRAGSIZE:
1026 		if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
1027 			goto e_inval;
1028 		if (val)
1029 			inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
1030 		else
1031 			inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
1032 		break;
1033 	case IP_TOS:	/* This sets both TOS and Precedence */
1034 		__ip_sock_set_tos(sk, val);
1035 		break;
1036 	case IP_TTL:
1037 		if (optlen < 1)
1038 			goto e_inval;
1039 		if (val != -1 && (val < 1 || val > 255))
1040 			goto e_inval;
1041 		inet->uc_ttl = val;
1042 		break;
1043 	case IP_HDRINCL:
1044 		if (sk->sk_type != SOCK_RAW) {
1045 			err = -ENOPROTOOPT;
1046 			break;
1047 		}
1048 		inet->hdrincl = val ? 1 : 0;
1049 		break;
1050 	case IP_NODEFRAG:
1051 		if (sk->sk_type != SOCK_RAW) {
1052 			err = -ENOPROTOOPT;
1053 			break;
1054 		}
1055 		inet->nodefrag = val ? 1 : 0;
1056 		break;
1057 	case IP_BIND_ADDRESS_NO_PORT:
1058 		inet->bind_address_no_port = val ? 1 : 0;
1059 		break;
1060 	case IP_MTU_DISCOVER:
1061 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
1062 			goto e_inval;
1063 		inet->pmtudisc = val;
1064 		break;
1065 	case IP_RECVERR:
1066 		inet->recverr = !!val;
1067 		if (!val)
1068 			skb_queue_purge(&sk->sk_error_queue);
1069 		break;
1070 	case IP_RECVERR_RFC4884:
1071 		if (val < 0 || val > 1)
1072 			goto e_inval;
1073 		inet->recverr_rfc4884 = !!val;
1074 		break;
1075 	case IP_MULTICAST_TTL:
1076 		if (sk->sk_type == SOCK_STREAM)
1077 			goto e_inval;
1078 		if (optlen < 1)
1079 			goto e_inval;
1080 		if (val == -1)
1081 			val = 1;
1082 		if (val < 0 || val > 255)
1083 			goto e_inval;
1084 		inet->mc_ttl = val;
1085 		break;
1086 	case IP_MULTICAST_LOOP:
1087 		if (optlen < 1)
1088 			goto e_inval;
1089 		inet->mc_loop = !!val;
1090 		break;
1091 	case IP_UNICAST_IF:
1092 	{
1093 		struct net_device *dev = NULL;
1094 		int ifindex;
1095 		int midx;
1096 
1097 		if (optlen != sizeof(int))
1098 			goto e_inval;
1099 
1100 		ifindex = (__force int)ntohl((__force __be32)val);
1101 		if (ifindex == 0) {
1102 			inet->uc_index = 0;
1103 			err = 0;
1104 			break;
1105 		}
1106 
1107 		dev = dev_get_by_index(sock_net(sk), ifindex);
1108 		err = -EADDRNOTAVAIL;
1109 		if (!dev)
1110 			break;
1111 
1112 		midx = l3mdev_master_ifindex(dev);
1113 		dev_put(dev);
1114 
1115 		err = -EINVAL;
1116 		if (sk->sk_bound_dev_if &&
1117 		    (!midx || midx != sk->sk_bound_dev_if))
1118 			break;
1119 
1120 		inet->uc_index = ifindex;
1121 		err = 0;
1122 		break;
1123 	}
1124 	case IP_MULTICAST_IF:
1125 	{
1126 		struct ip_mreqn mreq;
1127 		struct net_device *dev = NULL;
1128 		int midx;
1129 
1130 		if (sk->sk_type == SOCK_STREAM)
1131 			goto e_inval;
1132 		/*
1133 		 *	Check the arguments are allowable
1134 		 */
1135 
1136 		if (optlen < sizeof(struct in_addr))
1137 			goto e_inval;
1138 
1139 		err = -EFAULT;
1140 		if (optlen >= sizeof(struct ip_mreqn)) {
1141 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
1142 				break;
1143 		} else {
1144 			memset(&mreq, 0, sizeof(mreq));
1145 			if (optlen >= sizeof(struct ip_mreq)) {
1146 				if (copy_from_user(&mreq, optval,
1147 						   sizeof(struct ip_mreq)))
1148 					break;
1149 			} else if (optlen >= sizeof(struct in_addr)) {
1150 				if (copy_from_user(&mreq.imr_address, optval,
1151 						   sizeof(struct in_addr)))
1152 					break;
1153 			}
1154 		}
1155 
1156 		if (!mreq.imr_ifindex) {
1157 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
1158 				inet->mc_index = 0;
1159 				inet->mc_addr  = 0;
1160 				err = 0;
1161 				break;
1162 			}
1163 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
1164 			if (dev)
1165 				mreq.imr_ifindex = dev->ifindex;
1166 		} else
1167 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
1168 
1169 
1170 		err = -EADDRNOTAVAIL;
1171 		if (!dev)
1172 			break;
1173 
1174 		midx = l3mdev_master_ifindex(dev);
1175 
1176 		dev_put(dev);
1177 
1178 		err = -EINVAL;
1179 		if (sk->sk_bound_dev_if &&
1180 		    mreq.imr_ifindex != sk->sk_bound_dev_if &&
1181 		    (!midx || midx != sk->sk_bound_dev_if))
1182 			break;
1183 
1184 		inet->mc_index = mreq.imr_ifindex;
1185 		inet->mc_addr  = mreq.imr_address.s_addr;
1186 		err = 0;
1187 		break;
1188 	}
1189 
1190 	case IP_ADD_MEMBERSHIP:
1191 	case IP_DROP_MEMBERSHIP:
1192 	{
1193 		struct ip_mreqn mreq;
1194 
1195 		err = -EPROTO;
1196 		if (inet_sk(sk)->is_icsk)
1197 			break;
1198 
1199 		if (optlen < sizeof(struct ip_mreq))
1200 			goto e_inval;
1201 		err = -EFAULT;
1202 		if (optlen >= sizeof(struct ip_mreqn)) {
1203 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
1204 				break;
1205 		} else {
1206 			memset(&mreq, 0, sizeof(mreq));
1207 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
1208 				break;
1209 		}
1210 
1211 		if (optname == IP_ADD_MEMBERSHIP)
1212 			err = ip_mc_join_group(sk, &mreq);
1213 		else
1214 			err = ip_mc_leave_group(sk, &mreq);
1215 		break;
1216 	}
1217 	case IP_MSFILTER:
1218 	{
1219 		struct ip_msfilter *msf;
1220 
1221 		if (optlen < IP_MSFILTER_SIZE(0))
1222 			goto e_inval;
1223 		if (optlen > sysctl_optmem_max) {
1224 			err = -ENOBUFS;
1225 			break;
1226 		}
1227 		msf = memdup_user(optval, optlen);
1228 		if (IS_ERR(msf)) {
1229 			err = PTR_ERR(msf);
1230 			break;
1231 		}
1232 		/* numsrc >= (1G-4) overflow in 32 bits */
1233 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
1234 		    msf->imsf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
1235 			kfree(msf);
1236 			err = -ENOBUFS;
1237 			break;
1238 		}
1239 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
1240 			kfree(msf);
1241 			err = -EINVAL;
1242 			break;
1243 		}
1244 		err = ip_mc_msfilter(sk, msf, 0);
1245 		kfree(msf);
1246 		break;
1247 	}
1248 	case IP_BLOCK_SOURCE:
1249 	case IP_UNBLOCK_SOURCE:
1250 	case IP_ADD_SOURCE_MEMBERSHIP:
1251 	case IP_DROP_SOURCE_MEMBERSHIP:
1252 	{
1253 		struct ip_mreq_source mreqs;
1254 		int omode, add;
1255 
1256 		if (optlen != sizeof(struct ip_mreq_source))
1257 			goto e_inval;
1258 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
1259 			err = -EFAULT;
1260 			break;
1261 		}
1262 		if (optname == IP_BLOCK_SOURCE) {
1263 			omode = MCAST_EXCLUDE;
1264 			add = 1;
1265 		} else if (optname == IP_UNBLOCK_SOURCE) {
1266 			omode = MCAST_EXCLUDE;
1267 			add = 0;
1268 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
1269 			struct ip_mreqn mreq;
1270 
1271 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
1272 			mreq.imr_address.s_addr = mreqs.imr_interface;
1273 			mreq.imr_ifindex = 0;
1274 			err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
1275 			if (err && err != -EADDRINUSE)
1276 				break;
1277 			omode = MCAST_INCLUDE;
1278 			add = 1;
1279 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
1280 			omode = MCAST_INCLUDE;
1281 			add = 0;
1282 		}
1283 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
1284 		break;
1285 	}
1286 	case MCAST_JOIN_GROUP:
1287 	case MCAST_LEAVE_GROUP:
1288 		if (in_compat_syscall())
1289 			err = compat_ip_mcast_join_leave(sk, optname, optval,
1290 							 optlen);
1291 		else
1292 			err = ip_mcast_join_leave(sk, optname, optval, optlen);
1293 		break;
1294 	case MCAST_JOIN_SOURCE_GROUP:
1295 	case MCAST_LEAVE_SOURCE_GROUP:
1296 	case MCAST_BLOCK_SOURCE:
1297 	case MCAST_UNBLOCK_SOURCE:
1298 		err = do_mcast_group_source(sk, optname, optval, optlen);
1299 		break;
1300 	case MCAST_MSFILTER:
1301 		if (in_compat_syscall())
1302 			err = compat_ip_set_mcast_msfilter(sk, optval, optlen);
1303 		else
1304 			err = ip_set_mcast_msfilter(sk, optval, optlen);
1305 		break;
1306 	case IP_MULTICAST_ALL:
1307 		if (optlen < 1)
1308 			goto e_inval;
1309 		if (val != 0 && val != 1)
1310 			goto e_inval;
1311 		inet->mc_all = val;
1312 		break;
1313 
1314 	case IP_FREEBIND:
1315 		if (optlen < 1)
1316 			goto e_inval;
1317 		inet->freebind = !!val;
1318 		break;
1319 
1320 	case IP_IPSEC_POLICY:
1321 	case IP_XFRM_POLICY:
1322 		err = -EPERM;
1323 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1324 			break;
1325 		err = xfrm_user_policy(sk, optname, USER_SOCKPTR(optval),
1326 				       optlen);
1327 		break;
1328 
1329 	case IP_TRANSPARENT:
1330 		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1331 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1332 			err = -EPERM;
1333 			break;
1334 		}
1335 		if (optlen < 1)
1336 			goto e_inval;
1337 		inet->transparent = !!val;
1338 		break;
1339 
1340 	case IP_MINTTL:
1341 		if (optlen < 1)
1342 			goto e_inval;
1343 		if (val < 0 || val > 255)
1344 			goto e_inval;
1345 		inet->min_ttl = val;
1346 		break;
1347 
1348 	default:
1349 		err = -ENOPROTOOPT;
1350 		break;
1351 	}
1352 	release_sock(sk);
1353 	if (needs_rtnl)
1354 		rtnl_unlock();
1355 	return err;
1356 
1357 e_inval:
1358 	release_sock(sk);
1359 	if (needs_rtnl)
1360 		rtnl_unlock();
1361 	return -EINVAL;
1362 }
1363 
1364 /**
1365  * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1366  * @sk: socket
1367  * @skb: buffer
1368  *
1369  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1370  * destination in skb->cb[] before dst drop.
1371  * This way, receiver doesn't make cache line misses to read rtable.
1372  */
1373 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1374 {
1375 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1376 	bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1377 		       ipv6_sk_rxinfo(sk);
1378 
1379 	if (prepare && skb_rtable(skb)) {
1380 		/* skb->cb is overloaded: prior to this point it is IP{6}CB
1381 		 * which has interface index (iif) as the first member of the
1382 		 * underlying inet{6}_skb_parm struct. This code then overlays
1383 		 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
1384 		 * element so the iif is picked up from the prior IPCB. If iif
1385 		 * is the loopback interface, then return the sending interface
1386 		 * (e.g., process binds socket to eth0 for Tx which is
1387 		 * redirected to loopback in the rtable/dst).
1388 		 */
1389 		struct rtable *rt = skb_rtable(skb);
1390 		bool l3slave = ipv4_l3mdev_skb(IPCB(skb)->flags);
1391 
1392 		if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
1393 			pktinfo->ipi_ifindex = inet_iif(skb);
1394 		else if (l3slave && rt && rt->rt_iif)
1395 			pktinfo->ipi_ifindex = rt->rt_iif;
1396 
1397 		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1398 	} else {
1399 		pktinfo->ipi_ifindex = 0;
1400 		pktinfo->ipi_spec_dst.s_addr = 0;
1401 	}
1402 	skb_dst_drop(skb);
1403 }
1404 
1405 int ip_setsockopt(struct sock *sk, int level,
1406 		int optname, char __user *optval, unsigned int optlen)
1407 {
1408 	int err;
1409 
1410 	if (level != SOL_IP)
1411 		return -ENOPROTOOPT;
1412 
1413 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1414 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1415 	if (optname >= BPFILTER_IPT_SO_SET_REPLACE &&
1416 	    optname < BPFILTER_IPT_SET_MAX)
1417 		err = bpfilter_ip_set_sockopt(sk, optname, USER_SOCKPTR(optval),
1418 					      optlen);
1419 #endif
1420 #ifdef CONFIG_NETFILTER
1421 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1422 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1423 			optname != IP_IPSEC_POLICY &&
1424 			optname != IP_XFRM_POLICY &&
1425 			!ip_mroute_opt(optname))
1426 		err = nf_setsockopt(sk, PF_INET, optname, USER_SOCKPTR(optval),
1427 				    optlen);
1428 #endif
1429 	return err;
1430 }
1431 EXPORT_SYMBOL(ip_setsockopt);
1432 
1433 /*
1434  *	Get the options. Note for future reference. The GET of IP options gets
1435  *	the _received_ ones. The set sets the _sent_ ones.
1436  */
1437 
1438 static bool getsockopt_needs_rtnl(int optname)
1439 {
1440 	switch (optname) {
1441 	case IP_MSFILTER:
1442 	case MCAST_MSFILTER:
1443 		return true;
1444 	}
1445 	return false;
1446 }
1447 
1448 static int ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
1449 		int __user *optlen, int len)
1450 {
1451 	const int size0 = offsetof(struct group_filter, gf_slist);
1452 	struct group_filter __user *p = optval;
1453 	struct group_filter gsf;
1454 	int num;
1455 	int err;
1456 
1457 	if (len < size0)
1458 		return -EINVAL;
1459 	if (copy_from_user(&gsf, p, size0))
1460 		return -EFAULT;
1461 
1462 	num = gsf.gf_numsrc;
1463 	err = ip_mc_gsfget(sk, &gsf, p->gf_slist);
1464 	if (err)
1465 		return err;
1466 	if (gsf.gf_numsrc < num)
1467 		num = gsf.gf_numsrc;
1468 	if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
1469 	    copy_to_user(p, &gsf, size0))
1470 		return -EFAULT;
1471 	return 0;
1472 }
1473 
1474 static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
1475 		int __user *optlen, int len)
1476 {
1477 	const int size0 = offsetof(struct compat_group_filter, gf_slist);
1478 	struct compat_group_filter __user *p = optval;
1479 	struct compat_group_filter gf32;
1480 	struct group_filter gf;
1481 	int num;
1482 	int err;
1483 
1484 	if (len < size0)
1485 		return -EINVAL;
1486 	if (copy_from_user(&gf32, p, size0))
1487 		return -EFAULT;
1488 
1489 	gf.gf_interface = gf32.gf_interface;
1490 	gf.gf_fmode = gf32.gf_fmode;
1491 	num = gf.gf_numsrc = gf32.gf_numsrc;
1492 	gf.gf_group = gf32.gf_group;
1493 
1494 	err = ip_mc_gsfget(sk, &gf, p->gf_slist);
1495 	if (err)
1496 		return err;
1497 	if (gf.gf_numsrc < num)
1498 		num = gf.gf_numsrc;
1499 	len = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32));
1500 	if (put_user(len, optlen) ||
1501 	    put_user(gf.gf_fmode, &p->gf_fmode) ||
1502 	    put_user(gf.gf_numsrc, &p->gf_numsrc))
1503 		return -EFAULT;
1504 	return 0;
1505 }
1506 
1507 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1508 			    char __user *optval, int __user *optlen)
1509 {
1510 	struct inet_sock *inet = inet_sk(sk);
1511 	bool needs_rtnl = getsockopt_needs_rtnl(optname);
1512 	int val, err = 0;
1513 	int len;
1514 
1515 	if (level != SOL_IP)
1516 		return -EOPNOTSUPP;
1517 
1518 	if (ip_mroute_opt(optname))
1519 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1520 
1521 	if (get_user(len, optlen))
1522 		return -EFAULT;
1523 	if (len < 0)
1524 		return -EINVAL;
1525 
1526 	if (needs_rtnl)
1527 		rtnl_lock();
1528 	lock_sock(sk);
1529 
1530 	switch (optname) {
1531 	case IP_OPTIONS:
1532 	{
1533 		unsigned char optbuf[sizeof(struct ip_options)+40];
1534 		struct ip_options *opt = (struct ip_options *)optbuf;
1535 		struct ip_options_rcu *inet_opt;
1536 
1537 		inet_opt = rcu_dereference_protected(inet->inet_opt,
1538 						     lockdep_sock_is_held(sk));
1539 		opt->optlen = 0;
1540 		if (inet_opt)
1541 			memcpy(optbuf, &inet_opt->opt,
1542 			       sizeof(struct ip_options) +
1543 			       inet_opt->opt.optlen);
1544 		release_sock(sk);
1545 
1546 		if (opt->optlen == 0)
1547 			return put_user(0, optlen);
1548 
1549 		ip_options_undo(opt);
1550 
1551 		len = min_t(unsigned int, len, opt->optlen);
1552 		if (put_user(len, optlen))
1553 			return -EFAULT;
1554 		if (copy_to_user(optval, opt->__data, len))
1555 			return -EFAULT;
1556 		return 0;
1557 	}
1558 	case IP_PKTINFO:
1559 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1560 		break;
1561 	case IP_RECVTTL:
1562 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1563 		break;
1564 	case IP_RECVTOS:
1565 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1566 		break;
1567 	case IP_RECVOPTS:
1568 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1569 		break;
1570 	case IP_RETOPTS:
1571 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1572 		break;
1573 	case IP_PASSSEC:
1574 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1575 		break;
1576 	case IP_RECVORIGDSTADDR:
1577 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1578 		break;
1579 	case IP_CHECKSUM:
1580 		val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1581 		break;
1582 	case IP_RECVFRAGSIZE:
1583 		val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
1584 		break;
1585 	case IP_TOS:
1586 		val = inet->tos;
1587 		break;
1588 	case IP_TTL:
1589 	{
1590 		struct net *net = sock_net(sk);
1591 		val = (inet->uc_ttl == -1 ?
1592 		       net->ipv4.sysctl_ip_default_ttl :
1593 		       inet->uc_ttl);
1594 		break;
1595 	}
1596 	case IP_HDRINCL:
1597 		val = inet->hdrincl;
1598 		break;
1599 	case IP_NODEFRAG:
1600 		val = inet->nodefrag;
1601 		break;
1602 	case IP_BIND_ADDRESS_NO_PORT:
1603 		val = inet->bind_address_no_port;
1604 		break;
1605 	case IP_MTU_DISCOVER:
1606 		val = inet->pmtudisc;
1607 		break;
1608 	case IP_MTU:
1609 	{
1610 		struct dst_entry *dst;
1611 		val = 0;
1612 		dst = sk_dst_get(sk);
1613 		if (dst) {
1614 			val = dst_mtu(dst);
1615 			dst_release(dst);
1616 		}
1617 		if (!val) {
1618 			release_sock(sk);
1619 			return -ENOTCONN;
1620 		}
1621 		break;
1622 	}
1623 	case IP_RECVERR:
1624 		val = inet->recverr;
1625 		break;
1626 	case IP_RECVERR_RFC4884:
1627 		val = inet->recverr_rfc4884;
1628 		break;
1629 	case IP_MULTICAST_TTL:
1630 		val = inet->mc_ttl;
1631 		break;
1632 	case IP_MULTICAST_LOOP:
1633 		val = inet->mc_loop;
1634 		break;
1635 	case IP_UNICAST_IF:
1636 		val = (__force int)htonl((__u32) inet->uc_index);
1637 		break;
1638 	case IP_MULTICAST_IF:
1639 	{
1640 		struct in_addr addr;
1641 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1642 		addr.s_addr = inet->mc_addr;
1643 		release_sock(sk);
1644 
1645 		if (put_user(len, optlen))
1646 			return -EFAULT;
1647 		if (copy_to_user(optval, &addr, len))
1648 			return -EFAULT;
1649 		return 0;
1650 	}
1651 	case IP_MSFILTER:
1652 	{
1653 		struct ip_msfilter msf;
1654 
1655 		if (len < IP_MSFILTER_SIZE(0)) {
1656 			err = -EINVAL;
1657 			goto out;
1658 		}
1659 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1660 			err = -EFAULT;
1661 			goto out;
1662 		}
1663 		err = ip_mc_msfget(sk, &msf,
1664 				   (struct ip_msfilter __user *)optval, optlen);
1665 		goto out;
1666 	}
1667 	case MCAST_MSFILTER:
1668 		if (in_compat_syscall())
1669 			err = compat_ip_get_mcast_msfilter(sk, optval, optlen,
1670 							   len);
1671 		else
1672 			err = ip_get_mcast_msfilter(sk, optval, optlen, len);
1673 		goto out;
1674 	case IP_MULTICAST_ALL:
1675 		val = inet->mc_all;
1676 		break;
1677 	case IP_PKTOPTIONS:
1678 	{
1679 		struct msghdr msg;
1680 
1681 		release_sock(sk);
1682 
1683 		if (sk->sk_type != SOCK_STREAM)
1684 			return -ENOPROTOOPT;
1685 
1686 		msg.msg_control_is_user = true;
1687 		msg.msg_control_user = optval;
1688 		msg.msg_controllen = len;
1689 		msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0;
1690 
1691 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1692 			struct in_pktinfo info;
1693 
1694 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1695 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1696 			info.ipi_ifindex = inet->mc_index;
1697 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1698 		}
1699 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1700 			int hlim = inet->mc_ttl;
1701 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1702 		}
1703 		if (inet->cmsg_flags & IP_CMSG_TOS) {
1704 			int tos = inet->rcv_tos;
1705 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1706 		}
1707 		len -= msg.msg_controllen;
1708 		return put_user(len, optlen);
1709 	}
1710 	case IP_FREEBIND:
1711 		val = inet->freebind;
1712 		break;
1713 	case IP_TRANSPARENT:
1714 		val = inet->transparent;
1715 		break;
1716 	case IP_MINTTL:
1717 		val = inet->min_ttl;
1718 		break;
1719 	default:
1720 		release_sock(sk);
1721 		return -ENOPROTOOPT;
1722 	}
1723 	release_sock(sk);
1724 
1725 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1726 		unsigned char ucval = (unsigned char)val;
1727 		len = 1;
1728 		if (put_user(len, optlen))
1729 			return -EFAULT;
1730 		if (copy_to_user(optval, &ucval, 1))
1731 			return -EFAULT;
1732 	} else {
1733 		len = min_t(unsigned int, sizeof(int), len);
1734 		if (put_user(len, optlen))
1735 			return -EFAULT;
1736 		if (copy_to_user(optval, &val, len))
1737 			return -EFAULT;
1738 	}
1739 	return 0;
1740 
1741 out:
1742 	release_sock(sk);
1743 	if (needs_rtnl)
1744 		rtnl_unlock();
1745 	return err;
1746 }
1747 
1748 int ip_getsockopt(struct sock *sk, int level,
1749 		  int optname, char __user *optval, int __user *optlen)
1750 {
1751 	int err;
1752 
1753 	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
1754 
1755 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1756 	if (optname >= BPFILTER_IPT_SO_GET_INFO &&
1757 	    optname < BPFILTER_IPT_GET_MAX)
1758 		err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
1759 #endif
1760 #ifdef CONFIG_NETFILTER
1761 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1762 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1763 			!ip_mroute_opt(optname)) {
1764 		int len;
1765 
1766 		if (get_user(len, optlen))
1767 			return -EFAULT;
1768 
1769 		err = nf_getsockopt(sk, PF_INET, optname, optval, &len);
1770 		if (err >= 0)
1771 			err = put_user(len, optlen);
1772 		return err;
1773 	}
1774 #endif
1775 	return err;
1776 }
1777 EXPORT_SYMBOL(ip_getsockopt);
1778