xref: /linux/net/ipv4/ip_sockglue.c (revision cb8a14b205699fee1053a406e1e3fce330b6bdc3)
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 		skb_reset_transport_header(skb);
415 		if (sock_queue_err_skb(sk, skb) == 0)
416 			return;
417 	}
418 	kfree_skb(skb);
419 }
420 
421 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
422 {
423 	struct inet_sock *inet = inet_sk(sk);
424 	struct sock_exterr_skb *serr;
425 	struct iphdr *iph;
426 	struct sk_buff *skb;
427 
428 	if (!inet->recverr)
429 		return;
430 
431 	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
432 	if (!skb)
433 		return;
434 
435 	skb_put(skb, sizeof(struct iphdr));
436 	skb_reset_network_header(skb);
437 	iph = ip_hdr(skb);
438 	iph->daddr = daddr;
439 
440 	serr = SKB_EXT_ERR(skb);
441 	serr->ee.ee_errno = err;
442 	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
443 	serr->ee.ee_type = 0;
444 	serr->ee.ee_code = 0;
445 	serr->ee.ee_pad = 0;
446 	serr->ee.ee_info = info;
447 	serr->ee.ee_data = 0;
448 	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
449 	serr->port = port;
450 
451 	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
452 	skb_reset_transport_header(skb);
453 
454 	if (sock_queue_err_skb(sk, skb))
455 		kfree_skb(skb);
456 }
457 
458 /* For some errors we have valid addr_offset even with zero payload and
459  * zero port. Also, addr_offset should be supported if port is set.
460  */
461 static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
462 {
463 	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
464 	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
465 }
466 
467 /* IPv4 supports cmsg on all imcp errors and some timestamps
468  *
469  * Timestamp code paths do not initialize the fields expected by cmsg:
470  * the PKTINFO fields in skb->cb[]. Fill those in here.
471  */
472 static bool ipv4_datagram_support_cmsg(const struct sock *sk,
473 				       struct sk_buff *skb,
474 				       int ee_origin)
475 {
476 	struct in_pktinfo *info;
477 
478 	if (ee_origin == SO_EE_ORIGIN_ICMP)
479 		return true;
480 
481 	if (ee_origin == SO_EE_ORIGIN_LOCAL)
482 		return false;
483 
484 	/* Support IP_PKTINFO on tstamp packets if requested, to correlate
485 	 * timestamp with egress dev. Not possible for packets without iif
486 	 * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
487 	 */
488 	info = PKTINFO_SKB_CB(skb);
489 	if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) ||
490 	    !info->ipi_ifindex)
491 		return false;
492 
493 	info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
494 	return true;
495 }
496 
497 /*
498  *	Handle MSG_ERRQUEUE
499  */
500 int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
501 {
502 	struct sock_exterr_skb *serr;
503 	struct sk_buff *skb;
504 	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
505 	struct {
506 		struct sock_extended_err ee;
507 		struct sockaddr_in	 offender;
508 	} errhdr;
509 	int err;
510 	int copied;
511 
512 	err = -EAGAIN;
513 	skb = sock_dequeue_err_skb(sk);
514 	if (!skb)
515 		goto out;
516 
517 	copied = skb->len;
518 	if (copied > len) {
519 		msg->msg_flags |= MSG_TRUNC;
520 		copied = len;
521 	}
522 	err = skb_copy_datagram_msg(skb, 0, msg, copied);
523 	if (unlikely(err)) {
524 		kfree_skb(skb);
525 		return err;
526 	}
527 	sock_recv_timestamp(msg, sk, skb);
528 
529 	serr = SKB_EXT_ERR(skb);
530 
531 	if (sin && ipv4_datagram_support_addr(serr)) {
532 		sin->sin_family = AF_INET;
533 		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
534 						   serr->addr_offset);
535 		sin->sin_port = serr->port;
536 		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
537 		*addr_len = sizeof(*sin);
538 	}
539 
540 	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
541 	sin = &errhdr.offender;
542 	memset(sin, 0, sizeof(*sin));
543 
544 	if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
545 		sin->sin_family = AF_INET;
546 		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
547 		if (inet_sk(sk)->cmsg_flags)
548 			ip_cmsg_recv(msg, skb);
549 	}
550 
551 	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
552 
553 	/* Now we could try to dump offended packet options */
554 
555 	msg->msg_flags |= MSG_ERRQUEUE;
556 	err = copied;
557 
558 	consume_skb(skb);
559 out:
560 	return err;
561 }
562 
563 
564 /*
565  *	Socket option code for IP. This is the end of the line after any
566  *	TCP,UDP etc options on an IP socket.
567  */
568 static bool setsockopt_needs_rtnl(int optname)
569 {
570 	switch (optname) {
571 	case IP_ADD_MEMBERSHIP:
572 	case IP_ADD_SOURCE_MEMBERSHIP:
573 	case IP_BLOCK_SOURCE:
574 	case IP_DROP_MEMBERSHIP:
575 	case IP_DROP_SOURCE_MEMBERSHIP:
576 	case IP_MSFILTER:
577 	case IP_UNBLOCK_SOURCE:
578 	case MCAST_BLOCK_SOURCE:
579 	case MCAST_MSFILTER:
580 	case MCAST_JOIN_GROUP:
581 	case MCAST_JOIN_SOURCE_GROUP:
582 	case MCAST_LEAVE_GROUP:
583 	case MCAST_LEAVE_SOURCE_GROUP:
584 	case MCAST_UNBLOCK_SOURCE:
585 		return true;
586 	}
587 	return false;
588 }
589 
590 static int set_mcast_msfilter(struct sock *sk, int ifindex,
591 			      int numsrc, int fmode,
592 			      struct sockaddr_storage *group,
593 			      struct sockaddr_storage *list)
594 {
595 	int msize = IP_MSFILTER_SIZE(numsrc);
596 	struct ip_msfilter *msf;
597 	struct sockaddr_in *psin;
598 	int err, i;
599 
600 	msf = kmalloc(msize, GFP_KERNEL);
601 	if (!msf)
602 		return -ENOBUFS;
603 
604 	psin = (struct sockaddr_in *)group;
605 	if (psin->sin_family != AF_INET)
606 		goto Eaddrnotavail;
607 	msf->imsf_multiaddr = psin->sin_addr.s_addr;
608 	msf->imsf_interface = 0;
609 	msf->imsf_fmode = fmode;
610 	msf->imsf_numsrc = numsrc;
611 	for (i = 0; i < numsrc; ++i) {
612 		psin = (struct sockaddr_in *)&list[i];
613 
614 		if (psin->sin_family != AF_INET)
615 			goto Eaddrnotavail;
616 		msf->imsf_slist[i] = psin->sin_addr.s_addr;
617 	}
618 	err = ip_mc_msfilter(sk, msf, ifindex);
619 	kfree(msf);
620 	return err;
621 
622 Eaddrnotavail:
623 	kfree(msf);
624 	return -EADDRNOTAVAIL;
625 }
626 
627 static int do_mcast_group_source(struct sock *sk, int optname,
628 				 struct group_source_req *greqs)
629 {
630 	struct ip_mreq_source mreqs;
631 	struct sockaddr_in *psin;
632 	int omode, add, err;
633 
634 	if (greqs->gsr_group.ss_family != AF_INET ||
635 	    greqs->gsr_source.ss_family != AF_INET)
636 		return -EADDRNOTAVAIL;
637 
638 	psin = (struct sockaddr_in *)&greqs->gsr_group;
639 	mreqs.imr_multiaddr = psin->sin_addr.s_addr;
640 	psin = (struct sockaddr_in *)&greqs->gsr_source;
641 	mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
642 	mreqs.imr_interface = 0; /* use index for mc_source */
643 
644 	if (optname == MCAST_BLOCK_SOURCE) {
645 		omode = MCAST_EXCLUDE;
646 		add = 1;
647 	} else if (optname == MCAST_UNBLOCK_SOURCE) {
648 		omode = MCAST_EXCLUDE;
649 		add = 0;
650 	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
651 		struct ip_mreqn mreq;
652 
653 		psin = (struct sockaddr_in *)&greqs->gsr_group;
654 		mreq.imr_multiaddr = psin->sin_addr;
655 		mreq.imr_address.s_addr = 0;
656 		mreq.imr_ifindex = greqs->gsr_interface;
657 		err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
658 		if (err && err != -EADDRINUSE)
659 			return err;
660 		greqs->gsr_interface = mreq.imr_ifindex;
661 		omode = MCAST_INCLUDE;
662 		add = 1;
663 	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
664 		omode = MCAST_INCLUDE;
665 		add = 0;
666 	}
667 	return ip_mc_source(add, omode, sk, &mreqs, greqs->gsr_interface);
668 }
669 
670 static int do_ip_setsockopt(struct sock *sk, int level,
671 			    int optname, char __user *optval, unsigned int optlen)
672 {
673 	struct inet_sock *inet = inet_sk(sk);
674 	struct net *net = sock_net(sk);
675 	int val = 0, err;
676 	bool needs_rtnl = setsockopt_needs_rtnl(optname);
677 
678 	switch (optname) {
679 	case IP_PKTINFO:
680 	case IP_RECVTTL:
681 	case IP_RECVOPTS:
682 	case IP_RECVTOS:
683 	case IP_RETOPTS:
684 	case IP_TOS:
685 	case IP_TTL:
686 	case IP_HDRINCL:
687 	case IP_MTU_DISCOVER:
688 	case IP_RECVERR:
689 	case IP_ROUTER_ALERT:
690 	case IP_FREEBIND:
691 	case IP_PASSSEC:
692 	case IP_TRANSPARENT:
693 	case IP_MINTTL:
694 	case IP_NODEFRAG:
695 	case IP_BIND_ADDRESS_NO_PORT:
696 	case IP_UNICAST_IF:
697 	case IP_MULTICAST_TTL:
698 	case IP_MULTICAST_ALL:
699 	case IP_MULTICAST_LOOP:
700 	case IP_RECVORIGDSTADDR:
701 	case IP_CHECKSUM:
702 	case IP_RECVFRAGSIZE:
703 		if (optlen >= sizeof(int)) {
704 			if (get_user(val, (int __user *) optval))
705 				return -EFAULT;
706 		} else if (optlen >= sizeof(char)) {
707 			unsigned char ucval;
708 
709 			if (get_user(ucval, (unsigned char __user *) optval))
710 				return -EFAULT;
711 			val = (int) ucval;
712 		}
713 	}
714 
715 	/* If optlen==0, it is equivalent to val == 0 */
716 
717 	if (optname == IP_ROUTER_ALERT)
718 		return ip_ra_control(sk, val ? 1 : 0, NULL);
719 	if (ip_mroute_opt(optname))
720 		return ip_mroute_setsockopt(sk, optname, optval, optlen);
721 
722 	err = 0;
723 	if (needs_rtnl)
724 		rtnl_lock();
725 	lock_sock(sk);
726 
727 	switch (optname) {
728 	case IP_OPTIONS:
729 	{
730 		struct ip_options_rcu *old, *opt = NULL;
731 
732 		if (optlen > 40)
733 			goto e_inval;
734 		err = ip_options_get_from_user(sock_net(sk), &opt,
735 					       optval, optlen);
736 		if (err)
737 			break;
738 		old = rcu_dereference_protected(inet->inet_opt,
739 						lockdep_sock_is_held(sk));
740 		if (inet->is_icsk) {
741 			struct inet_connection_sock *icsk = inet_csk(sk);
742 #if IS_ENABLED(CONFIG_IPV6)
743 			if (sk->sk_family == PF_INET ||
744 			    (!((1 << sk->sk_state) &
745 			       (TCPF_LISTEN | TCPF_CLOSE)) &&
746 			     inet->inet_daddr != LOOPBACK4_IPV6)) {
747 #endif
748 				if (old)
749 					icsk->icsk_ext_hdr_len -= old->opt.optlen;
750 				if (opt)
751 					icsk->icsk_ext_hdr_len += opt->opt.optlen;
752 				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
753 #if IS_ENABLED(CONFIG_IPV6)
754 			}
755 #endif
756 		}
757 		rcu_assign_pointer(inet->inet_opt, opt);
758 		if (old)
759 			kfree_rcu(old, rcu);
760 		break;
761 	}
762 	case IP_PKTINFO:
763 		if (val)
764 			inet->cmsg_flags |= IP_CMSG_PKTINFO;
765 		else
766 			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
767 		break;
768 	case IP_RECVTTL:
769 		if (val)
770 			inet->cmsg_flags |=  IP_CMSG_TTL;
771 		else
772 			inet->cmsg_flags &= ~IP_CMSG_TTL;
773 		break;
774 	case IP_RECVTOS:
775 		if (val)
776 			inet->cmsg_flags |=  IP_CMSG_TOS;
777 		else
778 			inet->cmsg_flags &= ~IP_CMSG_TOS;
779 		break;
780 	case IP_RECVOPTS:
781 		if (val)
782 			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
783 		else
784 			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
785 		break;
786 	case IP_RETOPTS:
787 		if (val)
788 			inet->cmsg_flags |= IP_CMSG_RETOPTS;
789 		else
790 			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
791 		break;
792 	case IP_PASSSEC:
793 		if (val)
794 			inet->cmsg_flags |= IP_CMSG_PASSSEC;
795 		else
796 			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
797 		break;
798 	case IP_RECVORIGDSTADDR:
799 		if (val)
800 			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
801 		else
802 			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
803 		break;
804 	case IP_CHECKSUM:
805 		if (val) {
806 			if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
807 				inet_inc_convert_csum(sk);
808 				inet->cmsg_flags |= IP_CMSG_CHECKSUM;
809 			}
810 		} else {
811 			if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
812 				inet_dec_convert_csum(sk);
813 				inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
814 			}
815 		}
816 		break;
817 	case IP_RECVFRAGSIZE:
818 		if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
819 			goto e_inval;
820 		if (val)
821 			inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
822 		else
823 			inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
824 		break;
825 	case IP_TOS:	/* This sets both TOS and Precedence */
826 		if (sk->sk_type == SOCK_STREAM) {
827 			val &= ~INET_ECN_MASK;
828 			val |= inet->tos & INET_ECN_MASK;
829 		}
830 		if (inet->tos != val) {
831 			inet->tos = val;
832 			sk->sk_priority = rt_tos2priority(val);
833 			sk_dst_reset(sk);
834 		}
835 		break;
836 	case IP_TTL:
837 		if (optlen < 1)
838 			goto e_inval;
839 		if (val != -1 && (val < 1 || val > 255))
840 			goto e_inval;
841 		inet->uc_ttl = val;
842 		break;
843 	case IP_HDRINCL:
844 		if (sk->sk_type != SOCK_RAW) {
845 			err = -ENOPROTOOPT;
846 			break;
847 		}
848 		inet->hdrincl = val ? 1 : 0;
849 		break;
850 	case IP_NODEFRAG:
851 		if (sk->sk_type != SOCK_RAW) {
852 			err = -ENOPROTOOPT;
853 			break;
854 		}
855 		inet->nodefrag = val ? 1 : 0;
856 		break;
857 	case IP_BIND_ADDRESS_NO_PORT:
858 		inet->bind_address_no_port = val ? 1 : 0;
859 		break;
860 	case IP_MTU_DISCOVER:
861 		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
862 			goto e_inval;
863 		inet->pmtudisc = val;
864 		break;
865 	case IP_RECVERR:
866 		inet->recverr = !!val;
867 		if (!val)
868 			skb_queue_purge(&sk->sk_error_queue);
869 		break;
870 	case IP_MULTICAST_TTL:
871 		if (sk->sk_type == SOCK_STREAM)
872 			goto e_inval;
873 		if (optlen < 1)
874 			goto e_inval;
875 		if (val == -1)
876 			val = 1;
877 		if (val < 0 || val > 255)
878 			goto e_inval;
879 		inet->mc_ttl = val;
880 		break;
881 	case IP_MULTICAST_LOOP:
882 		if (optlen < 1)
883 			goto e_inval;
884 		inet->mc_loop = !!val;
885 		break;
886 	case IP_UNICAST_IF:
887 	{
888 		struct net_device *dev = NULL;
889 		int ifindex;
890 		int midx;
891 
892 		if (optlen != sizeof(int))
893 			goto e_inval;
894 
895 		ifindex = (__force int)ntohl((__force __be32)val);
896 		if (ifindex == 0) {
897 			inet->uc_index = 0;
898 			err = 0;
899 			break;
900 		}
901 
902 		dev = dev_get_by_index(sock_net(sk), ifindex);
903 		err = -EADDRNOTAVAIL;
904 		if (!dev)
905 			break;
906 
907 		midx = l3mdev_master_ifindex(dev);
908 		dev_put(dev);
909 
910 		err = -EINVAL;
911 		if (sk->sk_bound_dev_if &&
912 		    (!midx || midx != sk->sk_bound_dev_if))
913 			break;
914 
915 		inet->uc_index = ifindex;
916 		err = 0;
917 		break;
918 	}
919 	case IP_MULTICAST_IF:
920 	{
921 		struct ip_mreqn mreq;
922 		struct net_device *dev = NULL;
923 		int midx;
924 
925 		if (sk->sk_type == SOCK_STREAM)
926 			goto e_inval;
927 		/*
928 		 *	Check the arguments are allowable
929 		 */
930 
931 		if (optlen < sizeof(struct in_addr))
932 			goto e_inval;
933 
934 		err = -EFAULT;
935 		if (optlen >= sizeof(struct ip_mreqn)) {
936 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
937 				break;
938 		} else {
939 			memset(&mreq, 0, sizeof(mreq));
940 			if (optlen >= sizeof(struct ip_mreq)) {
941 				if (copy_from_user(&mreq, optval,
942 						   sizeof(struct ip_mreq)))
943 					break;
944 			} else if (optlen >= sizeof(struct in_addr)) {
945 				if (copy_from_user(&mreq.imr_address, optval,
946 						   sizeof(struct in_addr)))
947 					break;
948 			}
949 		}
950 
951 		if (!mreq.imr_ifindex) {
952 			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
953 				inet->mc_index = 0;
954 				inet->mc_addr  = 0;
955 				err = 0;
956 				break;
957 			}
958 			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
959 			if (dev)
960 				mreq.imr_ifindex = dev->ifindex;
961 		} else
962 			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
963 
964 
965 		err = -EADDRNOTAVAIL;
966 		if (!dev)
967 			break;
968 
969 		midx = l3mdev_master_ifindex(dev);
970 
971 		dev_put(dev);
972 
973 		err = -EINVAL;
974 		if (sk->sk_bound_dev_if &&
975 		    mreq.imr_ifindex != sk->sk_bound_dev_if &&
976 		    (!midx || midx != sk->sk_bound_dev_if))
977 			break;
978 
979 		inet->mc_index = mreq.imr_ifindex;
980 		inet->mc_addr  = mreq.imr_address.s_addr;
981 		err = 0;
982 		break;
983 	}
984 
985 	case IP_ADD_MEMBERSHIP:
986 	case IP_DROP_MEMBERSHIP:
987 	{
988 		struct ip_mreqn mreq;
989 
990 		err = -EPROTO;
991 		if (inet_sk(sk)->is_icsk)
992 			break;
993 
994 		if (optlen < sizeof(struct ip_mreq))
995 			goto e_inval;
996 		err = -EFAULT;
997 		if (optlen >= sizeof(struct ip_mreqn)) {
998 			if (copy_from_user(&mreq, optval, sizeof(mreq)))
999 				break;
1000 		} else {
1001 			memset(&mreq, 0, sizeof(mreq));
1002 			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
1003 				break;
1004 		}
1005 
1006 		if (optname == IP_ADD_MEMBERSHIP)
1007 			err = ip_mc_join_group(sk, &mreq);
1008 		else
1009 			err = ip_mc_leave_group(sk, &mreq);
1010 		break;
1011 	}
1012 	case IP_MSFILTER:
1013 	{
1014 		struct ip_msfilter *msf;
1015 
1016 		if (optlen < IP_MSFILTER_SIZE(0))
1017 			goto e_inval;
1018 		if (optlen > sysctl_optmem_max) {
1019 			err = -ENOBUFS;
1020 			break;
1021 		}
1022 		msf = memdup_user(optval, optlen);
1023 		if (IS_ERR(msf)) {
1024 			err = PTR_ERR(msf);
1025 			break;
1026 		}
1027 		/* numsrc >= (1G-4) overflow in 32 bits */
1028 		if (msf->imsf_numsrc >= 0x3ffffffcU ||
1029 		    msf->imsf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
1030 			kfree(msf);
1031 			err = -ENOBUFS;
1032 			break;
1033 		}
1034 		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
1035 			kfree(msf);
1036 			err = -EINVAL;
1037 			break;
1038 		}
1039 		err = ip_mc_msfilter(sk, msf, 0);
1040 		kfree(msf);
1041 		break;
1042 	}
1043 	case IP_BLOCK_SOURCE:
1044 	case IP_UNBLOCK_SOURCE:
1045 	case IP_ADD_SOURCE_MEMBERSHIP:
1046 	case IP_DROP_SOURCE_MEMBERSHIP:
1047 	{
1048 		struct ip_mreq_source mreqs;
1049 		int omode, add;
1050 
1051 		if (optlen != sizeof(struct ip_mreq_source))
1052 			goto e_inval;
1053 		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
1054 			err = -EFAULT;
1055 			break;
1056 		}
1057 		if (optname == IP_BLOCK_SOURCE) {
1058 			omode = MCAST_EXCLUDE;
1059 			add = 1;
1060 		} else if (optname == IP_UNBLOCK_SOURCE) {
1061 			omode = MCAST_EXCLUDE;
1062 			add = 0;
1063 		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
1064 			struct ip_mreqn mreq;
1065 
1066 			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
1067 			mreq.imr_address.s_addr = mreqs.imr_interface;
1068 			mreq.imr_ifindex = 0;
1069 			err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
1070 			if (err && err != -EADDRINUSE)
1071 				break;
1072 			omode = MCAST_INCLUDE;
1073 			add = 1;
1074 		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
1075 			omode = MCAST_INCLUDE;
1076 			add = 0;
1077 		}
1078 		err = ip_mc_source(add, omode, sk, &mreqs, 0);
1079 		break;
1080 	}
1081 	case MCAST_JOIN_GROUP:
1082 	case MCAST_LEAVE_GROUP:
1083 	{
1084 		struct group_req greq;
1085 		struct sockaddr_in *psin;
1086 		struct ip_mreqn mreq;
1087 
1088 		if (optlen < sizeof(struct group_req))
1089 			goto e_inval;
1090 		err = -EFAULT;
1091 		if (copy_from_user(&greq, optval, sizeof(greq)))
1092 			break;
1093 		psin = (struct sockaddr_in *)&greq.gr_group;
1094 		if (psin->sin_family != AF_INET)
1095 			goto e_inval;
1096 		memset(&mreq, 0, sizeof(mreq));
1097 		mreq.imr_multiaddr = psin->sin_addr;
1098 		mreq.imr_ifindex = greq.gr_interface;
1099 
1100 		if (optname == MCAST_JOIN_GROUP)
1101 			err = ip_mc_join_group(sk, &mreq);
1102 		else
1103 			err = ip_mc_leave_group(sk, &mreq);
1104 		break;
1105 	}
1106 	case MCAST_JOIN_SOURCE_GROUP:
1107 	case MCAST_LEAVE_SOURCE_GROUP:
1108 	case MCAST_BLOCK_SOURCE:
1109 	case MCAST_UNBLOCK_SOURCE:
1110 	{
1111 		struct group_source_req greqs;
1112 
1113 		if (optlen != sizeof(struct group_source_req))
1114 			goto e_inval;
1115 		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
1116 			err = -EFAULT;
1117 			break;
1118 		}
1119 		err = do_mcast_group_source(sk, optname, &greqs);
1120 		break;
1121 	}
1122 	case MCAST_MSFILTER:
1123 	{
1124 		struct group_filter *gsf = NULL;
1125 
1126 		if (optlen < GROUP_FILTER_SIZE(0))
1127 			goto e_inval;
1128 		if (optlen > sysctl_optmem_max) {
1129 			err = -ENOBUFS;
1130 			break;
1131 		}
1132 		gsf = memdup_user(optval, optlen);
1133 		if (IS_ERR(gsf)) {
1134 			err = PTR_ERR(gsf);
1135 			break;
1136 		}
1137 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
1138 		if (gsf->gf_numsrc >= 0x1ffffff ||
1139 		    gsf->gf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
1140 			err = -ENOBUFS;
1141 			goto mc_msf_out;
1142 		}
1143 		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
1144 			err = -EINVAL;
1145 			goto mc_msf_out;
1146 		}
1147 		err = set_mcast_msfilter(sk, gsf->gf_interface,
1148 					 gsf->gf_numsrc, gsf->gf_fmode,
1149 					 &gsf->gf_group, gsf->gf_slist);
1150 mc_msf_out:
1151 		kfree(gsf);
1152 		break;
1153 	}
1154 	case IP_MULTICAST_ALL:
1155 		if (optlen < 1)
1156 			goto e_inval;
1157 		if (val != 0 && val != 1)
1158 			goto e_inval;
1159 		inet->mc_all = val;
1160 		break;
1161 
1162 	case IP_FREEBIND:
1163 		if (optlen < 1)
1164 			goto e_inval;
1165 		inet->freebind = !!val;
1166 		break;
1167 
1168 	case IP_IPSEC_POLICY:
1169 	case IP_XFRM_POLICY:
1170 		err = -EPERM;
1171 		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1172 			break;
1173 		err = xfrm_user_policy(sk, optname, optval, optlen);
1174 		break;
1175 
1176 	case IP_TRANSPARENT:
1177 		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1178 		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1179 			err = -EPERM;
1180 			break;
1181 		}
1182 		if (optlen < 1)
1183 			goto e_inval;
1184 		inet->transparent = !!val;
1185 		break;
1186 
1187 	case IP_MINTTL:
1188 		if (optlen < 1)
1189 			goto e_inval;
1190 		if (val < 0 || val > 255)
1191 			goto e_inval;
1192 		inet->min_ttl = val;
1193 		break;
1194 
1195 	default:
1196 		err = -ENOPROTOOPT;
1197 		break;
1198 	}
1199 	release_sock(sk);
1200 	if (needs_rtnl)
1201 		rtnl_unlock();
1202 	return err;
1203 
1204 e_inval:
1205 	release_sock(sk);
1206 	if (needs_rtnl)
1207 		rtnl_unlock();
1208 	return -EINVAL;
1209 }
1210 
1211 /**
1212  * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1213  * @sk: socket
1214  * @skb: buffer
1215  *
1216  * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1217  * destination in skb->cb[] before dst drop.
1218  * This way, receiver doesn't make cache line misses to read rtable.
1219  */
1220 void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1221 {
1222 	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1223 	bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1224 		       ipv6_sk_rxinfo(sk);
1225 
1226 	if (prepare && skb_rtable(skb)) {
1227 		/* skb->cb is overloaded: prior to this point it is IP{6}CB
1228 		 * which has interface index (iif) as the first member of the
1229 		 * underlying inet{6}_skb_parm struct. This code then overlays
1230 		 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
1231 		 * element so the iif is picked up from the prior IPCB. If iif
1232 		 * is the loopback interface, then return the sending interface
1233 		 * (e.g., process binds socket to eth0 for Tx which is
1234 		 * redirected to loopback in the rtable/dst).
1235 		 */
1236 		struct rtable *rt = skb_rtable(skb);
1237 		bool l3slave = ipv4_l3mdev_skb(IPCB(skb)->flags);
1238 
1239 		if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
1240 			pktinfo->ipi_ifindex = inet_iif(skb);
1241 		else if (l3slave && rt && rt->rt_iif)
1242 			pktinfo->ipi_ifindex = rt->rt_iif;
1243 
1244 		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1245 	} else {
1246 		pktinfo->ipi_ifindex = 0;
1247 		pktinfo->ipi_spec_dst.s_addr = 0;
1248 	}
1249 	skb_dst_drop(skb);
1250 }
1251 
1252 int ip_setsockopt(struct sock *sk, int level,
1253 		int optname, char __user *optval, unsigned int optlen)
1254 {
1255 	int err;
1256 
1257 	if (level != SOL_IP)
1258 		return -ENOPROTOOPT;
1259 
1260 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1261 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1262 	if (optname >= BPFILTER_IPT_SO_SET_REPLACE &&
1263 	    optname < BPFILTER_IPT_SET_MAX)
1264 		err = bpfilter_ip_set_sockopt(sk, optname, optval, optlen);
1265 #endif
1266 #ifdef CONFIG_NETFILTER
1267 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1268 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1269 			optname != IP_IPSEC_POLICY &&
1270 			optname != IP_XFRM_POLICY &&
1271 			!ip_mroute_opt(optname))
1272 		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1273 #endif
1274 	return err;
1275 }
1276 EXPORT_SYMBOL(ip_setsockopt);
1277 
1278 #ifdef CONFIG_COMPAT
1279 int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1280 			 char __user *optval, unsigned int optlen)
1281 {
1282 	int err;
1283 
1284 	if (level != SOL_IP)
1285 		return -ENOPROTOOPT;
1286 
1287 	switch (optname) {
1288 	case MCAST_JOIN_GROUP:
1289 	case MCAST_LEAVE_GROUP:
1290 	{
1291 		struct compat_group_req __user *gr32 = (void __user *)optval;
1292 		struct group_req greq;
1293 		struct sockaddr_in *psin = (struct sockaddr_in *)&greq.gr_group;
1294 		struct ip_mreqn mreq;
1295 
1296 		if (optlen < sizeof(struct compat_group_req))
1297 			return -EINVAL;
1298 
1299 		if (get_user(greq.gr_interface, &gr32->gr_interface) ||
1300 		    copy_from_user(&greq.gr_group, &gr32->gr_group,
1301 				sizeof(greq.gr_group)))
1302 			return -EFAULT;
1303 
1304 		if (psin->sin_family != AF_INET)
1305 			return -EINVAL;
1306 
1307 		memset(&mreq, 0, sizeof(mreq));
1308 		mreq.imr_multiaddr = psin->sin_addr;
1309 		mreq.imr_ifindex = greq.gr_interface;
1310 
1311 		rtnl_lock();
1312 		lock_sock(sk);
1313 		if (optname == MCAST_JOIN_GROUP)
1314 			err = ip_mc_join_group(sk, &mreq);
1315 		else
1316 			err = ip_mc_leave_group(sk, &mreq);
1317 		release_sock(sk);
1318 		rtnl_unlock();
1319 		return err;
1320 	}
1321 	case MCAST_JOIN_SOURCE_GROUP:
1322 	case MCAST_LEAVE_SOURCE_GROUP:
1323 	case MCAST_BLOCK_SOURCE:
1324 	case MCAST_UNBLOCK_SOURCE:
1325 	{
1326 		struct compat_group_source_req __user *gsr32 = (void __user *)optval;
1327 		struct group_source_req greqs;
1328 
1329 		if (optlen != sizeof(struct compat_group_source_req))
1330 			return -EINVAL;
1331 
1332 		if (get_user(greqs.gsr_interface, &gsr32->gsr_interface) ||
1333 		    copy_from_user(&greqs.gsr_group, &gsr32->gsr_group,
1334 				sizeof(greqs.gsr_group)) ||
1335 		    copy_from_user(&greqs.gsr_source, &gsr32->gsr_source,
1336 				sizeof(greqs.gsr_source)))
1337 			return -EFAULT;
1338 
1339 		rtnl_lock();
1340 		lock_sock(sk);
1341 		err = do_mcast_group_source(sk, optname, &greqs);
1342 		release_sock(sk);
1343 		rtnl_unlock();
1344 		return err;
1345 	}
1346 	case MCAST_MSFILTER:
1347 	{
1348 		const int size0 = offsetof(struct compat_group_filter, gf_slist);
1349 		struct compat_group_filter *gf32;
1350 		void *p;
1351 		int n;
1352 
1353 		if (optlen < size0)
1354 			return -EINVAL;
1355 		if (optlen > sysctl_optmem_max - 4)
1356 			return -ENOBUFS;
1357 
1358 		p = kmalloc(optlen + 4, GFP_KERNEL);
1359 		if (!p)
1360 			return -ENOMEM;
1361 		gf32 = p + 4; /* we want ->gf_group and ->gf_slist aligned */
1362 		if (copy_from_user(gf32, optval, optlen)) {
1363 			err = -EFAULT;
1364 			goto mc_msf_out;
1365 		}
1366 
1367 		n = gf32->gf_numsrc;
1368 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
1369 		if (n >= 0x1ffffff) {
1370 			err = -ENOBUFS;
1371 			goto mc_msf_out;
1372 		}
1373 		if (offsetof(struct compat_group_filter, gf_slist[n]) > optlen) {
1374 			err = -EINVAL;
1375 			goto mc_msf_out;
1376 		}
1377 
1378 		rtnl_lock();
1379 		lock_sock(sk);
1380 		/* numsrc >= (4G-140)/128 overflow in 32 bits */
1381 		if (n > sock_net(sk)->ipv4.sysctl_igmp_max_msf)
1382 			err = -ENOBUFS;
1383 		else
1384 			err = set_mcast_msfilter(sk, gf32->gf_interface,
1385 						 n, gf32->gf_fmode,
1386 						 &gf32->gf_group, gf32->gf_slist);
1387 		release_sock(sk);
1388 		rtnl_unlock();
1389 mc_msf_out:
1390 		kfree(p);
1391 		return err;
1392 	}
1393 	}
1394 
1395 	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1396 #ifdef CONFIG_NETFILTER
1397 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1398 	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1399 			optname != IP_IPSEC_POLICY &&
1400 			optname != IP_XFRM_POLICY &&
1401 			!ip_mroute_opt(optname))
1402 		err = compat_nf_setsockopt(sk, PF_INET, optname, optval,
1403 					   optlen);
1404 #endif
1405 	return err;
1406 }
1407 EXPORT_SYMBOL(compat_ip_setsockopt);
1408 #endif
1409 
1410 /*
1411  *	Get the options. Note for future reference. The GET of IP options gets
1412  *	the _received_ ones. The set sets the _sent_ ones.
1413  */
1414 
1415 static bool getsockopt_needs_rtnl(int optname)
1416 {
1417 	switch (optname) {
1418 	case IP_MSFILTER:
1419 	case MCAST_MSFILTER:
1420 		return true;
1421 	}
1422 	return false;
1423 }
1424 
1425 static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1426 			    char __user *optval, int __user *optlen, unsigned int flags)
1427 {
1428 	struct inet_sock *inet = inet_sk(sk);
1429 	bool needs_rtnl = getsockopt_needs_rtnl(optname);
1430 	int val, err = 0;
1431 	int len;
1432 
1433 	if (level != SOL_IP)
1434 		return -EOPNOTSUPP;
1435 
1436 	if (ip_mroute_opt(optname))
1437 		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1438 
1439 	if (get_user(len, optlen))
1440 		return -EFAULT;
1441 	if (len < 0)
1442 		return -EINVAL;
1443 
1444 	if (needs_rtnl)
1445 		rtnl_lock();
1446 	lock_sock(sk);
1447 
1448 	switch (optname) {
1449 	case IP_OPTIONS:
1450 	{
1451 		unsigned char optbuf[sizeof(struct ip_options)+40];
1452 		struct ip_options *opt = (struct ip_options *)optbuf;
1453 		struct ip_options_rcu *inet_opt;
1454 
1455 		inet_opt = rcu_dereference_protected(inet->inet_opt,
1456 						     lockdep_sock_is_held(sk));
1457 		opt->optlen = 0;
1458 		if (inet_opt)
1459 			memcpy(optbuf, &inet_opt->opt,
1460 			       sizeof(struct ip_options) +
1461 			       inet_opt->opt.optlen);
1462 		release_sock(sk);
1463 
1464 		if (opt->optlen == 0)
1465 			return put_user(0, optlen);
1466 
1467 		ip_options_undo(opt);
1468 
1469 		len = min_t(unsigned int, len, opt->optlen);
1470 		if (put_user(len, optlen))
1471 			return -EFAULT;
1472 		if (copy_to_user(optval, opt->__data, len))
1473 			return -EFAULT;
1474 		return 0;
1475 	}
1476 	case IP_PKTINFO:
1477 		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1478 		break;
1479 	case IP_RECVTTL:
1480 		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1481 		break;
1482 	case IP_RECVTOS:
1483 		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1484 		break;
1485 	case IP_RECVOPTS:
1486 		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1487 		break;
1488 	case IP_RETOPTS:
1489 		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1490 		break;
1491 	case IP_PASSSEC:
1492 		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1493 		break;
1494 	case IP_RECVORIGDSTADDR:
1495 		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1496 		break;
1497 	case IP_CHECKSUM:
1498 		val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1499 		break;
1500 	case IP_RECVFRAGSIZE:
1501 		val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
1502 		break;
1503 	case IP_TOS:
1504 		val = inet->tos;
1505 		break;
1506 	case IP_TTL:
1507 	{
1508 		struct net *net = sock_net(sk);
1509 		val = (inet->uc_ttl == -1 ?
1510 		       net->ipv4.sysctl_ip_default_ttl :
1511 		       inet->uc_ttl);
1512 		break;
1513 	}
1514 	case IP_HDRINCL:
1515 		val = inet->hdrincl;
1516 		break;
1517 	case IP_NODEFRAG:
1518 		val = inet->nodefrag;
1519 		break;
1520 	case IP_BIND_ADDRESS_NO_PORT:
1521 		val = inet->bind_address_no_port;
1522 		break;
1523 	case IP_MTU_DISCOVER:
1524 		val = inet->pmtudisc;
1525 		break;
1526 	case IP_MTU:
1527 	{
1528 		struct dst_entry *dst;
1529 		val = 0;
1530 		dst = sk_dst_get(sk);
1531 		if (dst) {
1532 			val = dst_mtu(dst);
1533 			dst_release(dst);
1534 		}
1535 		if (!val) {
1536 			release_sock(sk);
1537 			return -ENOTCONN;
1538 		}
1539 		break;
1540 	}
1541 	case IP_RECVERR:
1542 		val = inet->recverr;
1543 		break;
1544 	case IP_MULTICAST_TTL:
1545 		val = inet->mc_ttl;
1546 		break;
1547 	case IP_MULTICAST_LOOP:
1548 		val = inet->mc_loop;
1549 		break;
1550 	case IP_UNICAST_IF:
1551 		val = (__force int)htonl((__u32) inet->uc_index);
1552 		break;
1553 	case IP_MULTICAST_IF:
1554 	{
1555 		struct in_addr addr;
1556 		len = min_t(unsigned int, len, sizeof(struct in_addr));
1557 		addr.s_addr = inet->mc_addr;
1558 		release_sock(sk);
1559 
1560 		if (put_user(len, optlen))
1561 			return -EFAULT;
1562 		if (copy_to_user(optval, &addr, len))
1563 			return -EFAULT;
1564 		return 0;
1565 	}
1566 	case IP_MSFILTER:
1567 	{
1568 		struct ip_msfilter msf;
1569 
1570 		if (len < IP_MSFILTER_SIZE(0)) {
1571 			err = -EINVAL;
1572 			goto out;
1573 		}
1574 		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1575 			err = -EFAULT;
1576 			goto out;
1577 		}
1578 		err = ip_mc_msfget(sk, &msf,
1579 				   (struct ip_msfilter __user *)optval, optlen);
1580 		goto out;
1581 	}
1582 	case MCAST_MSFILTER:
1583 	{
1584 		struct group_filter __user *p = (void __user *)optval;
1585 		struct group_filter gsf;
1586 		const int size0 = offsetof(struct group_filter, gf_slist);
1587 		int num;
1588 
1589 		if (len < size0) {
1590 			err = -EINVAL;
1591 			goto out;
1592 		}
1593 		if (copy_from_user(&gsf, p, size0)) {
1594 			err = -EFAULT;
1595 			goto out;
1596 		}
1597 		num = gsf.gf_numsrc;
1598 		err = ip_mc_gsfget(sk, &gsf, p->gf_slist);
1599 		if (err)
1600 			goto out;
1601 		if (gsf.gf_numsrc < num)
1602 			num = gsf.gf_numsrc;
1603 		if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
1604 		    copy_to_user(p, &gsf, size0))
1605 			err = -EFAULT;
1606 		goto out;
1607 	}
1608 	case IP_MULTICAST_ALL:
1609 		val = inet->mc_all;
1610 		break;
1611 	case IP_PKTOPTIONS:
1612 	{
1613 		struct msghdr msg;
1614 
1615 		release_sock(sk);
1616 
1617 		if (sk->sk_type != SOCK_STREAM)
1618 			return -ENOPROTOOPT;
1619 
1620 		msg.msg_control_is_user = true;
1621 		msg.msg_control_user = optval;
1622 		msg.msg_controllen = len;
1623 		msg.msg_flags = flags;
1624 
1625 		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1626 			struct in_pktinfo info;
1627 
1628 			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1629 			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1630 			info.ipi_ifindex = inet->mc_index;
1631 			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1632 		}
1633 		if (inet->cmsg_flags & IP_CMSG_TTL) {
1634 			int hlim = inet->mc_ttl;
1635 			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1636 		}
1637 		if (inet->cmsg_flags & IP_CMSG_TOS) {
1638 			int tos = inet->rcv_tos;
1639 			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1640 		}
1641 		len -= msg.msg_controllen;
1642 		return put_user(len, optlen);
1643 	}
1644 	case IP_FREEBIND:
1645 		val = inet->freebind;
1646 		break;
1647 	case IP_TRANSPARENT:
1648 		val = inet->transparent;
1649 		break;
1650 	case IP_MINTTL:
1651 		val = inet->min_ttl;
1652 		break;
1653 	default:
1654 		release_sock(sk);
1655 		return -ENOPROTOOPT;
1656 	}
1657 	release_sock(sk);
1658 
1659 	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1660 		unsigned char ucval = (unsigned char)val;
1661 		len = 1;
1662 		if (put_user(len, optlen))
1663 			return -EFAULT;
1664 		if (copy_to_user(optval, &ucval, 1))
1665 			return -EFAULT;
1666 	} else {
1667 		len = min_t(unsigned int, sizeof(int), len);
1668 		if (put_user(len, optlen))
1669 			return -EFAULT;
1670 		if (copy_to_user(optval, &val, len))
1671 			return -EFAULT;
1672 	}
1673 	return 0;
1674 
1675 out:
1676 	release_sock(sk);
1677 	if (needs_rtnl)
1678 		rtnl_unlock();
1679 	return err;
1680 }
1681 
1682 int ip_getsockopt(struct sock *sk, int level,
1683 		  int optname, char __user *optval, int __user *optlen)
1684 {
1685 	int err;
1686 
1687 	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1688 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1689 	if (optname >= BPFILTER_IPT_SO_GET_INFO &&
1690 	    optname < BPFILTER_IPT_GET_MAX)
1691 		err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
1692 #endif
1693 #ifdef CONFIG_NETFILTER
1694 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1695 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1696 			!ip_mroute_opt(optname)) {
1697 		int len;
1698 
1699 		if (get_user(len, optlen))
1700 			return -EFAULT;
1701 
1702 		err = nf_getsockopt(sk, PF_INET, optname, optval, &len);
1703 		if (err >= 0)
1704 			err = put_user(len, optlen);
1705 		return err;
1706 	}
1707 #endif
1708 	return err;
1709 }
1710 EXPORT_SYMBOL(ip_getsockopt);
1711 
1712 #ifdef CONFIG_COMPAT
1713 int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1714 			 char __user *optval, int __user *optlen)
1715 {
1716 	int err;
1717 
1718 	if (optname == MCAST_MSFILTER) {
1719 		const int size0 = offsetof(struct compat_group_filter, gf_slist);
1720 		struct compat_group_filter __user *p = (void __user *)optval;
1721 		struct compat_group_filter gf32;
1722 		struct group_filter gf;
1723 		int ulen, err;
1724 		int num;
1725 
1726 		if (level != SOL_IP)
1727 			return -EOPNOTSUPP;
1728 
1729 		if (get_user(ulen, optlen))
1730 			return -EFAULT;
1731 
1732 		if (ulen < size0)
1733 			return -EINVAL;
1734 
1735 		if (copy_from_user(&gf32, p, size0))
1736 			return -EFAULT;
1737 
1738 		gf.gf_interface = gf32.gf_interface;
1739 		gf.gf_fmode = gf32.gf_fmode;
1740 		num = gf.gf_numsrc = gf32.gf_numsrc;
1741 		gf.gf_group = gf32.gf_group;
1742 
1743 		rtnl_lock();
1744 		lock_sock(sk);
1745 		err = ip_mc_gsfget(sk, &gf, p->gf_slist);
1746 		release_sock(sk);
1747 		rtnl_unlock();
1748 		if (err)
1749 			return err;
1750 		if (gf.gf_numsrc < num)
1751 			num = gf.gf_numsrc;
1752 		ulen = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32));
1753 		if (put_user(ulen, optlen) ||
1754 		    put_user(gf.gf_fmode, &p->gf_fmode) ||
1755 		    put_user(gf.gf_numsrc, &p->gf_numsrc))
1756 			return -EFAULT;
1757 		return 0;
1758 	}
1759 
1760 	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1761 		MSG_CMSG_COMPAT);
1762 
1763 #if IS_ENABLED(CONFIG_BPFILTER_UMH)
1764 	if (optname >= BPFILTER_IPT_SO_GET_INFO &&
1765 	    optname < BPFILTER_IPT_GET_MAX)
1766 		err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
1767 #endif
1768 #ifdef CONFIG_NETFILTER
1769 	/* we need to exclude all possible ENOPROTOOPTs except default case */
1770 	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1771 			!ip_mroute_opt(optname)) {
1772 		int len;
1773 
1774 		if (get_user(len, optlen))
1775 			return -EFAULT;
1776 
1777 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1778 		if (err >= 0)
1779 			err = put_user(len, optlen);
1780 		return err;
1781 	}
1782 #endif
1783 	return err;
1784 }
1785 EXPORT_SYMBOL(compat_ip_getsockopt);
1786 #endif
1787