xref: /kernel/linux/linux-5.10/net/ipv4/ip_sockglue.c (revision 8c2ecf20)
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
56static 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
65static 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
71static 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
76static 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
86static 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
104static 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
115static 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
131static 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
149static 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
171void 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}
240EXPORT_SYMBOL(ip_cmsg_recv_offset);
241
242int 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,
284					     KERNEL_SOCKPTR(CMSG_DATA(cmsg)),
285					     err < 40 ? err : 40);
286			if (err)
287				return err;
288			break;
289		case IP_PKTINFO:
290		{
291			struct in_pktinfo *info;
292			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
293				return -EINVAL;
294			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
295			if (info->ipi_ifindex)
296				ipc->oif = info->ipi_ifindex;
297			ipc->addr = info->ipi_spec_dst.s_addr;
298			break;
299		}
300		case IP_TTL:
301			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
302				return -EINVAL;
303			val = *(int *)CMSG_DATA(cmsg);
304			if (val < 1 || val > 255)
305				return -EINVAL;
306			ipc->ttl = val;
307			break;
308		case IP_TOS:
309			if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)))
310				val = *(int *)CMSG_DATA(cmsg);
311			else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8)))
312				val = *(u8 *)CMSG_DATA(cmsg);
313			else
314				return -EINVAL;
315			if (val < 0 || val > 255)
316				return -EINVAL;
317			ipc->tos = val;
318			ipc->priority = rt_tos2priority(ipc->tos);
319			break;
320		case IP_PROTOCOL:
321			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
322				return -EINVAL;
323			val = *(int *)CMSG_DATA(cmsg);
324			if (val < 1 || val > 255)
325				return -EINVAL;
326			ipc->protocol = val;
327			break;
328		default:
329			return -EINVAL;
330		}
331	}
332	return 0;
333}
334
335static void ip_ra_destroy_rcu(struct rcu_head *head)
336{
337	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
338
339	sock_put(ra->saved_sk);
340	kfree(ra);
341}
342
343int ip_ra_control(struct sock *sk, unsigned char on,
344		  void (*destructor)(struct sock *))
345{
346	struct ip_ra_chain *ra, *new_ra;
347	struct ip_ra_chain __rcu **rap;
348	struct net *net = sock_net(sk);
349
350	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
351		return -EINVAL;
352
353	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
354	if (on && !new_ra)
355		return -ENOMEM;
356
357	mutex_lock(&net->ipv4.ra_mutex);
358	for (rap = &net->ipv4.ra_chain;
359	     (ra = rcu_dereference_protected(*rap,
360			lockdep_is_held(&net->ipv4.ra_mutex))) != NULL;
361	     rap = &ra->next) {
362		if (ra->sk == sk) {
363			if (on) {
364				mutex_unlock(&net->ipv4.ra_mutex);
365				kfree(new_ra);
366				return -EADDRINUSE;
367			}
368			/* dont let ip_call_ra_chain() use sk again */
369			ra->sk = NULL;
370			RCU_INIT_POINTER(*rap, ra->next);
371			mutex_unlock(&net->ipv4.ra_mutex);
372
373			if (ra->destructor)
374				ra->destructor(sk);
375			/*
376			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
377			 * period. This guarantee ip_call_ra_chain() dont need
378			 * to mess with socket refcounts.
379			 */
380			ra->saved_sk = sk;
381			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
382			return 0;
383		}
384	}
385	if (!new_ra) {
386		mutex_unlock(&net->ipv4.ra_mutex);
387		return -ENOBUFS;
388	}
389	new_ra->sk = sk;
390	new_ra->destructor = destructor;
391
392	RCU_INIT_POINTER(new_ra->next, ra);
393	rcu_assign_pointer(*rap, new_ra);
394	sock_hold(sk);
395	mutex_unlock(&net->ipv4.ra_mutex);
396
397	return 0;
398}
399
400static void ipv4_icmp_error_rfc4884(const struct sk_buff *skb,
401				    struct sock_ee_data_rfc4884 *out)
402{
403	switch (icmp_hdr(skb)->type) {
404	case ICMP_DEST_UNREACH:
405	case ICMP_TIME_EXCEEDED:
406	case ICMP_PARAMETERPROB:
407		ip_icmp_error_rfc4884(skb, out, sizeof(struct icmphdr),
408				      icmp_hdr(skb)->un.reserved[1] * 4);
409	}
410}
411
412void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
413		   __be16 port, u32 info, u8 *payload)
414{
415	struct sock_exterr_skb *serr;
416
417	skb = skb_clone(skb, GFP_ATOMIC);
418	if (!skb)
419		return;
420
421	serr = SKB_EXT_ERR(skb);
422	serr->ee.ee_errno = err;
423	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
424	serr->ee.ee_type = icmp_hdr(skb)->type;
425	serr->ee.ee_code = icmp_hdr(skb)->code;
426	serr->ee.ee_pad = 0;
427	serr->ee.ee_info = info;
428	serr->ee.ee_data = 0;
429	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
430				   skb_network_header(skb);
431	serr->port = port;
432
433	if (skb_pull(skb, payload - skb->data)) {
434		if (inet_sk(sk)->recverr_rfc4884)
435			ipv4_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
436
437		skb_reset_transport_header(skb);
438		if (sock_queue_err_skb(sk, skb) == 0)
439			return;
440	}
441	kfree_skb(skb);
442}
443
444void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
445{
446	struct inet_sock *inet = inet_sk(sk);
447	struct sock_exterr_skb *serr;
448	struct iphdr *iph;
449	struct sk_buff *skb;
450
451	if (!inet->recverr)
452		return;
453
454	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
455	if (!skb)
456		return;
457
458	skb_put(skb, sizeof(struct iphdr));
459	skb_reset_network_header(skb);
460	iph = ip_hdr(skb);
461	iph->daddr = daddr;
462
463	serr = SKB_EXT_ERR(skb);
464	serr->ee.ee_errno = err;
465	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
466	serr->ee.ee_type = 0;
467	serr->ee.ee_code = 0;
468	serr->ee.ee_pad = 0;
469	serr->ee.ee_info = info;
470	serr->ee.ee_data = 0;
471	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
472	serr->port = port;
473
474	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
475	skb_reset_transport_header(skb);
476
477	if (sock_queue_err_skb(sk, skb))
478		kfree_skb(skb);
479}
480
481/* For some errors we have valid addr_offset even with zero payload and
482 * zero port. Also, addr_offset should be supported if port is set.
483 */
484static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
485{
486	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
487	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
488}
489
490/* IPv4 supports cmsg on all imcp errors and some timestamps
491 *
492 * Timestamp code paths do not initialize the fields expected by cmsg:
493 * the PKTINFO fields in skb->cb[]. Fill those in here.
494 */
495static bool ipv4_datagram_support_cmsg(const struct sock *sk,
496				       struct sk_buff *skb,
497				       int ee_origin)
498{
499	struct in_pktinfo *info;
500
501	if (ee_origin == SO_EE_ORIGIN_ICMP)
502		return true;
503
504	if (ee_origin == SO_EE_ORIGIN_LOCAL)
505		return false;
506
507	/* Support IP_PKTINFO on tstamp packets if requested, to correlate
508	 * timestamp with egress dev. Not possible for packets without iif
509	 * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
510	 */
511	info = PKTINFO_SKB_CB(skb);
512	if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) ||
513	    !info->ipi_ifindex)
514		return false;
515
516	info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
517	return true;
518}
519
520/*
521 *	Handle MSG_ERRQUEUE
522 */
523int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
524{
525	struct sock_exterr_skb *serr;
526	struct sk_buff *skb;
527	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
528	struct {
529		struct sock_extended_err ee;
530		struct sockaddr_in	 offender;
531	} errhdr;
532	int err;
533	int copied;
534
535	err = -EAGAIN;
536	skb = sock_dequeue_err_skb(sk);
537	if (!skb)
538		goto out;
539
540	copied = skb->len;
541	if (copied > len) {
542		msg->msg_flags |= MSG_TRUNC;
543		copied = len;
544	}
545	err = skb_copy_datagram_msg(skb, 0, msg, copied);
546	if (unlikely(err)) {
547		kfree_skb(skb);
548		return err;
549	}
550	sock_recv_timestamp(msg, sk, skb);
551
552	serr = SKB_EXT_ERR(skb);
553
554	if (sin && ipv4_datagram_support_addr(serr)) {
555		sin->sin_family = AF_INET;
556		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
557						   serr->addr_offset);
558		sin->sin_port = serr->port;
559		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
560		*addr_len = sizeof(*sin);
561	}
562
563	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
564	sin = &errhdr.offender;
565	memset(sin, 0, sizeof(*sin));
566
567	if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
568		sin->sin_family = AF_INET;
569		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
570		if (inet_sk(sk)->cmsg_flags)
571			ip_cmsg_recv(msg, skb);
572	}
573
574	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
575
576	/* Now we could try to dump offended packet options */
577
578	msg->msg_flags |= MSG_ERRQUEUE;
579	err = copied;
580
581	consume_skb(skb);
582out:
583	return err;
584}
585
586static void __ip_sock_set_tos(struct sock *sk, int val)
587{
588	if (sk->sk_type == SOCK_STREAM) {
589		val &= ~INET_ECN_MASK;
590		val |= inet_sk(sk)->tos & INET_ECN_MASK;
591	}
592	if (inet_sk(sk)->tos != val) {
593		inet_sk(sk)->tos = val;
594		sk->sk_priority = rt_tos2priority(val);
595		sk_dst_reset(sk);
596	}
597}
598
599void ip_sock_set_tos(struct sock *sk, int val)
600{
601	lock_sock(sk);
602	__ip_sock_set_tos(sk, val);
603	release_sock(sk);
604}
605EXPORT_SYMBOL(ip_sock_set_tos);
606
607void ip_sock_set_freebind(struct sock *sk)
608{
609	lock_sock(sk);
610	inet_sk(sk)->freebind = true;
611	release_sock(sk);
612}
613EXPORT_SYMBOL(ip_sock_set_freebind);
614
615void ip_sock_set_recverr(struct sock *sk)
616{
617	lock_sock(sk);
618	inet_sk(sk)->recverr = true;
619	release_sock(sk);
620}
621EXPORT_SYMBOL(ip_sock_set_recverr);
622
623int ip_sock_set_mtu_discover(struct sock *sk, int val)
624{
625	if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
626		return -EINVAL;
627	lock_sock(sk);
628	inet_sk(sk)->pmtudisc = val;
629	release_sock(sk);
630	return 0;
631}
632EXPORT_SYMBOL(ip_sock_set_mtu_discover);
633
634void ip_sock_set_pktinfo(struct sock *sk)
635{
636	lock_sock(sk);
637	inet_sk(sk)->cmsg_flags |= IP_CMSG_PKTINFO;
638	release_sock(sk);
639}
640EXPORT_SYMBOL(ip_sock_set_pktinfo);
641
642/*
643 *	Socket option code for IP. This is the end of the line after any
644 *	TCP,UDP etc options on an IP socket.
645 */
646static bool setsockopt_needs_rtnl(int optname)
647{
648	switch (optname) {
649	case IP_ADD_MEMBERSHIP:
650	case IP_ADD_SOURCE_MEMBERSHIP:
651	case IP_BLOCK_SOURCE:
652	case IP_DROP_MEMBERSHIP:
653	case IP_DROP_SOURCE_MEMBERSHIP:
654	case IP_MSFILTER:
655	case IP_UNBLOCK_SOURCE:
656	case MCAST_BLOCK_SOURCE:
657	case MCAST_MSFILTER:
658	case MCAST_JOIN_GROUP:
659	case MCAST_JOIN_SOURCE_GROUP:
660	case MCAST_LEAVE_GROUP:
661	case MCAST_LEAVE_SOURCE_GROUP:
662	case MCAST_UNBLOCK_SOURCE:
663		return true;
664	}
665	return false;
666}
667
668static int set_mcast_msfilter(struct sock *sk, int ifindex,
669			      int numsrc, int fmode,
670			      struct sockaddr_storage *group,
671			      struct sockaddr_storage *list)
672{
673	int msize = IP_MSFILTER_SIZE(numsrc);
674	struct ip_msfilter *msf;
675	struct sockaddr_in *psin;
676	int err, i;
677
678	msf = kmalloc(msize, GFP_KERNEL);
679	if (!msf)
680		return -ENOBUFS;
681
682	psin = (struct sockaddr_in *)group;
683	if (psin->sin_family != AF_INET)
684		goto Eaddrnotavail;
685	msf->imsf_multiaddr = psin->sin_addr.s_addr;
686	msf->imsf_interface = 0;
687	msf->imsf_fmode = fmode;
688	msf->imsf_numsrc = numsrc;
689	for (i = 0; i < numsrc; ++i) {
690		psin = (struct sockaddr_in *)&list[i];
691
692		if (psin->sin_family != AF_INET)
693			goto Eaddrnotavail;
694		msf->imsf_slist[i] = psin->sin_addr.s_addr;
695	}
696	err = ip_mc_msfilter(sk, msf, ifindex);
697	kfree(msf);
698	return err;
699
700Eaddrnotavail:
701	kfree(msf);
702	return -EADDRNOTAVAIL;
703}
704
705static int copy_group_source_from_sockptr(struct group_source_req *greqs,
706		sockptr_t optval, int optlen)
707{
708	if (in_compat_syscall()) {
709		struct compat_group_source_req gr32;
710
711		if (optlen != sizeof(gr32))
712			return -EINVAL;
713		if (copy_from_sockptr(&gr32, optval, sizeof(gr32)))
714			return -EFAULT;
715		greqs->gsr_interface = gr32.gsr_interface;
716		greqs->gsr_group = gr32.gsr_group;
717		greqs->gsr_source = gr32.gsr_source;
718	} else {
719		if (optlen != sizeof(*greqs))
720			return -EINVAL;
721		if (copy_from_sockptr(greqs, optval, sizeof(*greqs)))
722			return -EFAULT;
723	}
724
725	return 0;
726}
727
728static int do_mcast_group_source(struct sock *sk, int optname,
729		sockptr_t optval, int optlen)
730{
731	struct group_source_req greqs;
732	struct ip_mreq_source mreqs;
733	struct sockaddr_in *psin;
734	int omode, add, err;
735
736	err = copy_group_source_from_sockptr(&greqs, optval, optlen);
737	if (err)
738		return err;
739
740	if (greqs.gsr_group.ss_family != AF_INET ||
741	    greqs.gsr_source.ss_family != AF_INET)
742		return -EADDRNOTAVAIL;
743
744	psin = (struct sockaddr_in *)&greqs.gsr_group;
745	mreqs.imr_multiaddr = psin->sin_addr.s_addr;
746	psin = (struct sockaddr_in *)&greqs.gsr_source;
747	mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
748	mreqs.imr_interface = 0; /* use index for mc_source */
749
750	if (optname == MCAST_BLOCK_SOURCE) {
751		omode = MCAST_EXCLUDE;
752		add = 1;
753	} else if (optname == MCAST_UNBLOCK_SOURCE) {
754		omode = MCAST_EXCLUDE;
755		add = 0;
756	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
757		struct ip_mreqn mreq;
758
759		psin = (struct sockaddr_in *)&greqs.gsr_group;
760		mreq.imr_multiaddr = psin->sin_addr;
761		mreq.imr_address.s_addr = 0;
762		mreq.imr_ifindex = greqs.gsr_interface;
763		err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
764		if (err && err != -EADDRINUSE)
765			return err;
766		greqs.gsr_interface = mreq.imr_ifindex;
767		omode = MCAST_INCLUDE;
768		add = 1;
769	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
770		omode = MCAST_INCLUDE;
771		add = 0;
772	}
773	return ip_mc_source(add, omode, sk, &mreqs, greqs.gsr_interface);
774}
775
776static int ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval, int optlen)
777{
778	struct group_filter *gsf = NULL;
779	int err;
780
781	if (optlen < GROUP_FILTER_SIZE(0))
782		return -EINVAL;
783	if (optlen > READ_ONCE(sysctl_optmem_max))
784		return -ENOBUFS;
785
786	gsf = memdup_sockptr(optval, optlen);
787	if (IS_ERR(gsf))
788		return PTR_ERR(gsf);
789
790	/* numsrc >= (4G-140)/128 overflow in 32 bits */
791	err = -ENOBUFS;
792	if (gsf->gf_numsrc >= 0x1ffffff ||
793	    gsf->gf_numsrc > READ_ONCE(sock_net(sk)->ipv4.sysctl_igmp_max_msf))
794		goto out_free_gsf;
795
796	err = -EINVAL;
797	if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen)
798		goto out_free_gsf;
799
800	err = set_mcast_msfilter(sk, gsf->gf_interface, gsf->gf_numsrc,
801				 gsf->gf_fmode, &gsf->gf_group, gsf->gf_slist);
802out_free_gsf:
803	kfree(gsf);
804	return err;
805}
806
807static int compat_ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
808		int optlen)
809{
810	const int size0 = offsetof(struct compat_group_filter, gf_slist);
811	struct compat_group_filter *gf32;
812	unsigned int n;
813	void *p;
814	int err;
815
816	if (optlen < size0)
817		return -EINVAL;
818	if (optlen > READ_ONCE(sysctl_optmem_max) - 4)
819		return -ENOBUFS;
820
821	p = kmalloc(optlen + 4, GFP_KERNEL);
822	if (!p)
823		return -ENOMEM;
824	gf32 = p + 4; /* we want ->gf_group and ->gf_slist aligned */
825
826	err = -EFAULT;
827	if (copy_from_sockptr(gf32, optval, optlen))
828		goto out_free_gsf;
829
830	/* numsrc >= (4G-140)/128 overflow in 32 bits */
831	n = gf32->gf_numsrc;
832	err = -ENOBUFS;
833	if (n >= 0x1ffffff)
834		goto out_free_gsf;
835
836	err = -EINVAL;
837	if (offsetof(struct compat_group_filter, gf_slist[n]) > optlen)
838		goto out_free_gsf;
839
840	/* numsrc >= (4G-140)/128 overflow in 32 bits */
841	err = -ENOBUFS;
842	if (n > READ_ONCE(sock_net(sk)->ipv4.sysctl_igmp_max_msf))
843		goto out_free_gsf;
844	err = set_mcast_msfilter(sk, gf32->gf_interface, n, gf32->gf_fmode,
845				 &gf32->gf_group, gf32->gf_slist);
846out_free_gsf:
847	kfree(p);
848	return err;
849}
850
851static int ip_mcast_join_leave(struct sock *sk, int optname,
852		sockptr_t optval, int optlen)
853{
854	struct ip_mreqn mreq = { };
855	struct sockaddr_in *psin;
856	struct group_req greq;
857
858	if (optlen < sizeof(struct group_req))
859		return -EINVAL;
860	if (copy_from_sockptr(&greq, optval, sizeof(greq)))
861		return -EFAULT;
862
863	psin = (struct sockaddr_in *)&greq.gr_group;
864	if (psin->sin_family != AF_INET)
865		return -EINVAL;
866	mreq.imr_multiaddr = psin->sin_addr;
867	mreq.imr_ifindex = greq.gr_interface;
868	if (optname == MCAST_JOIN_GROUP)
869		return ip_mc_join_group(sk, &mreq);
870	return ip_mc_leave_group(sk, &mreq);
871}
872
873static int compat_ip_mcast_join_leave(struct sock *sk, int optname,
874		sockptr_t optval, int optlen)
875{
876	struct compat_group_req greq;
877	struct ip_mreqn mreq = { };
878	struct sockaddr_in *psin;
879
880	if (optlen < sizeof(struct compat_group_req))
881		return -EINVAL;
882	if (copy_from_sockptr(&greq, optval, sizeof(greq)))
883		return -EFAULT;
884
885	psin = (struct sockaddr_in *)&greq.gr_group;
886	if (psin->sin_family != AF_INET)
887		return -EINVAL;
888	mreq.imr_multiaddr = psin->sin_addr;
889	mreq.imr_ifindex = greq.gr_interface;
890
891	if (optname == MCAST_JOIN_GROUP)
892		return ip_mc_join_group(sk, &mreq);
893	return ip_mc_leave_group(sk, &mreq);
894}
895
896static int do_ip_setsockopt(struct sock *sk, int level, int optname,
897		sockptr_t optval, unsigned int optlen)
898{
899	struct inet_sock *inet = inet_sk(sk);
900	struct net *net = sock_net(sk);
901	int val = 0, err;
902	bool needs_rtnl = setsockopt_needs_rtnl(optname);
903
904	switch (optname) {
905	case IP_PKTINFO:
906	case IP_RECVTTL:
907	case IP_RECVOPTS:
908	case IP_RECVTOS:
909	case IP_RETOPTS:
910	case IP_TOS:
911	case IP_TTL:
912	case IP_HDRINCL:
913	case IP_MTU_DISCOVER:
914	case IP_RECVERR:
915	case IP_ROUTER_ALERT:
916	case IP_FREEBIND:
917	case IP_PASSSEC:
918	case IP_TRANSPARENT:
919	case IP_MINTTL:
920	case IP_NODEFRAG:
921	case IP_BIND_ADDRESS_NO_PORT:
922	case IP_UNICAST_IF:
923	case IP_MULTICAST_TTL:
924	case IP_MULTICAST_ALL:
925	case IP_MULTICAST_LOOP:
926	case IP_RECVORIGDSTADDR:
927	case IP_CHECKSUM:
928	case IP_RECVFRAGSIZE:
929	case IP_RECVERR_RFC4884:
930		if (optlen >= sizeof(int)) {
931			if (copy_from_sockptr(&val, optval, sizeof(val)))
932				return -EFAULT;
933		} else if (optlen >= sizeof(char)) {
934			unsigned char ucval;
935
936			if (copy_from_sockptr(&ucval, optval, sizeof(ucval)))
937				return -EFAULT;
938			val = (int) ucval;
939		}
940	}
941
942	/* If optlen==0, it is equivalent to val == 0 */
943
944	if (optname == IP_ROUTER_ALERT)
945		return ip_ra_control(sk, val ? 1 : 0, NULL);
946	if (ip_mroute_opt(optname))
947		return ip_mroute_setsockopt(sk, optname, optval, optlen);
948
949	err = 0;
950	if (needs_rtnl)
951		rtnl_lock();
952	lock_sock(sk);
953
954	switch (optname) {
955	case IP_OPTIONS:
956	{
957		struct ip_options_rcu *old, *opt = NULL;
958
959		if (optlen > 40)
960			goto e_inval;
961		err = ip_options_get(sock_net(sk), &opt, optval, optlen);
962		if (err)
963			break;
964		old = rcu_dereference_protected(inet->inet_opt,
965						lockdep_sock_is_held(sk));
966		if (inet->is_icsk) {
967			struct inet_connection_sock *icsk = inet_csk(sk);
968#if IS_ENABLED(CONFIG_IPV6)
969			if (sk->sk_family == PF_INET ||
970			    (!((1 << sk->sk_state) &
971			       (TCPF_LISTEN | TCPF_CLOSE)) &&
972			     inet->inet_daddr != LOOPBACK4_IPV6)) {
973#endif
974				if (old)
975					icsk->icsk_ext_hdr_len -= old->opt.optlen;
976				if (opt)
977					icsk->icsk_ext_hdr_len += opt->opt.optlen;
978				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
979#if IS_ENABLED(CONFIG_IPV6)
980			}
981#endif
982		}
983		rcu_assign_pointer(inet->inet_opt, opt);
984		if (old)
985			kfree_rcu(old, rcu);
986		break;
987	}
988	case IP_PKTINFO:
989		if (val)
990			inet->cmsg_flags |= IP_CMSG_PKTINFO;
991		else
992			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
993		break;
994	case IP_RECVTTL:
995		if (val)
996			inet->cmsg_flags |=  IP_CMSG_TTL;
997		else
998			inet->cmsg_flags &= ~IP_CMSG_TTL;
999		break;
1000	case IP_RECVTOS:
1001		if (val)
1002			inet->cmsg_flags |=  IP_CMSG_TOS;
1003		else
1004			inet->cmsg_flags &= ~IP_CMSG_TOS;
1005		break;
1006	case IP_RECVOPTS:
1007		if (val)
1008			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
1009		else
1010			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
1011		break;
1012	case IP_RETOPTS:
1013		if (val)
1014			inet->cmsg_flags |= IP_CMSG_RETOPTS;
1015		else
1016			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
1017		break;
1018	case IP_PASSSEC:
1019		if (val)
1020			inet->cmsg_flags |= IP_CMSG_PASSSEC;
1021		else
1022			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
1023		break;
1024	case IP_RECVORIGDSTADDR:
1025		if (val)
1026			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
1027		else
1028			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
1029		break;
1030	case IP_CHECKSUM:
1031		if (val) {
1032			if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
1033				inet_inc_convert_csum(sk);
1034				inet->cmsg_flags |= IP_CMSG_CHECKSUM;
1035			}
1036		} else {
1037			if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
1038				inet_dec_convert_csum(sk);
1039				inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
1040			}
1041		}
1042		break;
1043	case IP_RECVFRAGSIZE:
1044		if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
1045			goto e_inval;
1046		if (val)
1047			inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
1048		else
1049			inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
1050		break;
1051	case IP_TOS:	/* This sets both TOS and Precedence */
1052		__ip_sock_set_tos(sk, val);
1053		break;
1054	case IP_TTL:
1055		if (optlen < 1)
1056			goto e_inval;
1057		if (val != -1 && (val < 1 || val > 255))
1058			goto e_inval;
1059		inet->uc_ttl = val;
1060		break;
1061	case IP_HDRINCL:
1062		if (sk->sk_type != SOCK_RAW) {
1063			err = -ENOPROTOOPT;
1064			break;
1065		}
1066		inet->hdrincl = val ? 1 : 0;
1067		break;
1068	case IP_NODEFRAG:
1069		if (sk->sk_type != SOCK_RAW) {
1070			err = -ENOPROTOOPT;
1071			break;
1072		}
1073		inet->nodefrag = val ? 1 : 0;
1074		break;
1075	case IP_BIND_ADDRESS_NO_PORT:
1076		inet->bind_address_no_port = val ? 1 : 0;
1077		break;
1078	case IP_MTU_DISCOVER:
1079		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
1080			goto e_inval;
1081		inet->pmtudisc = val;
1082		break;
1083	case IP_RECVERR:
1084		inet->recverr = !!val;
1085		if (!val)
1086			skb_queue_purge(&sk->sk_error_queue);
1087		break;
1088	case IP_RECVERR_RFC4884:
1089		if (val < 0 || val > 1)
1090			goto e_inval;
1091		inet->recverr_rfc4884 = !!val;
1092		break;
1093	case IP_MULTICAST_TTL:
1094		if (sk->sk_type == SOCK_STREAM)
1095			goto e_inval;
1096		if (optlen < 1)
1097			goto e_inval;
1098		if (val == -1)
1099			val = 1;
1100		if (val < 0 || val > 255)
1101			goto e_inval;
1102		inet->mc_ttl = val;
1103		break;
1104	case IP_MULTICAST_LOOP:
1105		if (optlen < 1)
1106			goto e_inval;
1107		inet->mc_loop = !!val;
1108		break;
1109	case IP_UNICAST_IF:
1110	{
1111		struct net_device *dev = NULL;
1112		int ifindex;
1113		int midx;
1114
1115		if (optlen != sizeof(int))
1116			goto e_inval;
1117
1118		ifindex = (__force int)ntohl((__force __be32)val);
1119		if (ifindex == 0) {
1120			inet->uc_index = 0;
1121			err = 0;
1122			break;
1123		}
1124
1125		dev = dev_get_by_index(sock_net(sk), ifindex);
1126		err = -EADDRNOTAVAIL;
1127		if (!dev)
1128			break;
1129
1130		midx = l3mdev_master_ifindex(dev);
1131		dev_put(dev);
1132
1133		err = -EINVAL;
1134		if (sk->sk_bound_dev_if && midx != sk->sk_bound_dev_if)
1135			break;
1136
1137		inet->uc_index = ifindex;
1138		err = 0;
1139		break;
1140	}
1141	case IP_MULTICAST_IF:
1142	{
1143		struct ip_mreqn mreq;
1144		struct net_device *dev = NULL;
1145		int midx;
1146
1147		if (sk->sk_type == SOCK_STREAM)
1148			goto e_inval;
1149		/*
1150		 *	Check the arguments are allowable
1151		 */
1152
1153		if (optlen < sizeof(struct in_addr))
1154			goto e_inval;
1155
1156		err = -EFAULT;
1157		if (optlen >= sizeof(struct ip_mreqn)) {
1158			if (copy_from_sockptr(&mreq, optval, sizeof(mreq)))
1159				break;
1160		} else {
1161			memset(&mreq, 0, sizeof(mreq));
1162			if (optlen >= sizeof(struct ip_mreq)) {
1163				if (copy_from_sockptr(&mreq, optval,
1164						      sizeof(struct ip_mreq)))
1165					break;
1166			} else if (optlen >= sizeof(struct in_addr)) {
1167				if (copy_from_sockptr(&mreq.imr_address, optval,
1168						      sizeof(struct in_addr)))
1169					break;
1170			}
1171		}
1172
1173		if (!mreq.imr_ifindex) {
1174			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
1175				inet->mc_index = 0;
1176				inet->mc_addr  = 0;
1177				err = 0;
1178				break;
1179			}
1180			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
1181			if (dev)
1182				mreq.imr_ifindex = dev->ifindex;
1183		} else
1184			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
1185
1186
1187		err = -EADDRNOTAVAIL;
1188		if (!dev)
1189			break;
1190
1191		midx = l3mdev_master_ifindex(dev);
1192
1193		dev_put(dev);
1194
1195		err = -EINVAL;
1196		if (sk->sk_bound_dev_if &&
1197		    mreq.imr_ifindex != sk->sk_bound_dev_if &&
1198		    midx != sk->sk_bound_dev_if)
1199			break;
1200
1201		inet->mc_index = mreq.imr_ifindex;
1202		inet->mc_addr  = mreq.imr_address.s_addr;
1203		err = 0;
1204		break;
1205	}
1206
1207	case IP_ADD_MEMBERSHIP:
1208	case IP_DROP_MEMBERSHIP:
1209	{
1210		struct ip_mreqn mreq;
1211
1212		err = -EPROTO;
1213		if (inet_sk(sk)->is_icsk)
1214			break;
1215
1216		if (optlen < sizeof(struct ip_mreq))
1217			goto e_inval;
1218		err = -EFAULT;
1219		if (optlen >= sizeof(struct ip_mreqn)) {
1220			if (copy_from_sockptr(&mreq, optval, sizeof(mreq)))
1221				break;
1222		} else {
1223			memset(&mreq, 0, sizeof(mreq));
1224			if (copy_from_sockptr(&mreq, optval,
1225					      sizeof(struct ip_mreq)))
1226				break;
1227		}
1228
1229		if (optname == IP_ADD_MEMBERSHIP)
1230			err = ip_mc_join_group(sk, &mreq);
1231		else
1232			err = ip_mc_leave_group(sk, &mreq);
1233		break;
1234	}
1235	case IP_MSFILTER:
1236	{
1237		struct ip_msfilter *msf;
1238
1239		if (optlen < IP_MSFILTER_SIZE(0))
1240			goto e_inval;
1241		if (optlen > READ_ONCE(sysctl_optmem_max)) {
1242			err = -ENOBUFS;
1243			break;
1244		}
1245		msf = memdup_sockptr(optval, optlen);
1246		if (IS_ERR(msf)) {
1247			err = PTR_ERR(msf);
1248			break;
1249		}
1250		/* numsrc >= (1G-4) overflow in 32 bits */
1251		if (msf->imsf_numsrc >= 0x3ffffffcU ||
1252		    msf->imsf_numsrc > READ_ONCE(net->ipv4.sysctl_igmp_max_msf)) {
1253			kfree(msf);
1254			err = -ENOBUFS;
1255			break;
1256		}
1257		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
1258			kfree(msf);
1259			err = -EINVAL;
1260			break;
1261		}
1262		err = ip_mc_msfilter(sk, msf, 0);
1263		kfree(msf);
1264		break;
1265	}
1266	case IP_BLOCK_SOURCE:
1267	case IP_UNBLOCK_SOURCE:
1268	case IP_ADD_SOURCE_MEMBERSHIP:
1269	case IP_DROP_SOURCE_MEMBERSHIP:
1270	{
1271		struct ip_mreq_source mreqs;
1272		int omode, add;
1273
1274		if (optlen != sizeof(struct ip_mreq_source))
1275			goto e_inval;
1276		if (copy_from_sockptr(&mreqs, optval, sizeof(mreqs))) {
1277			err = -EFAULT;
1278			break;
1279		}
1280		if (optname == IP_BLOCK_SOURCE) {
1281			omode = MCAST_EXCLUDE;
1282			add = 1;
1283		} else if (optname == IP_UNBLOCK_SOURCE) {
1284			omode = MCAST_EXCLUDE;
1285			add = 0;
1286		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
1287			struct ip_mreqn mreq;
1288
1289			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
1290			mreq.imr_address.s_addr = mreqs.imr_interface;
1291			mreq.imr_ifindex = 0;
1292			err = ip_mc_join_group_ssm(sk, &mreq, MCAST_INCLUDE);
1293			if (err && err != -EADDRINUSE)
1294				break;
1295			omode = MCAST_INCLUDE;
1296			add = 1;
1297		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
1298			omode = MCAST_INCLUDE;
1299			add = 0;
1300		}
1301		err = ip_mc_source(add, omode, sk, &mreqs, 0);
1302		break;
1303	}
1304	case MCAST_JOIN_GROUP:
1305	case MCAST_LEAVE_GROUP:
1306		if (in_compat_syscall())
1307			err = compat_ip_mcast_join_leave(sk, optname, optval,
1308							 optlen);
1309		else
1310			err = ip_mcast_join_leave(sk, optname, optval, optlen);
1311		break;
1312	case MCAST_JOIN_SOURCE_GROUP:
1313	case MCAST_LEAVE_SOURCE_GROUP:
1314	case MCAST_BLOCK_SOURCE:
1315	case MCAST_UNBLOCK_SOURCE:
1316		err = do_mcast_group_source(sk, optname, optval, optlen);
1317		break;
1318	case MCAST_MSFILTER:
1319		if (in_compat_syscall())
1320			err = compat_ip_set_mcast_msfilter(sk, optval, optlen);
1321		else
1322			err = ip_set_mcast_msfilter(sk, optval, optlen);
1323		break;
1324	case IP_MULTICAST_ALL:
1325		if (optlen < 1)
1326			goto e_inval;
1327		if (val != 0 && val != 1)
1328			goto e_inval;
1329		inet->mc_all = val;
1330		break;
1331
1332	case IP_FREEBIND:
1333		if (optlen < 1)
1334			goto e_inval;
1335		inet->freebind = !!val;
1336		break;
1337
1338	case IP_IPSEC_POLICY:
1339	case IP_XFRM_POLICY:
1340		err = -EPERM;
1341		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1342			break;
1343		err = xfrm_user_policy(sk, optname, optval, optlen);
1344		break;
1345
1346	case IP_TRANSPARENT:
1347		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1348		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1349			err = -EPERM;
1350			break;
1351		}
1352		if (optlen < 1)
1353			goto e_inval;
1354		inet->transparent = !!val;
1355		break;
1356
1357	case IP_MINTTL:
1358		if (optlen < 1)
1359			goto e_inval;
1360		if (val < 0 || val > 255)
1361			goto e_inval;
1362		inet->min_ttl = val;
1363		break;
1364
1365	default:
1366		err = -ENOPROTOOPT;
1367		break;
1368	}
1369	release_sock(sk);
1370	if (needs_rtnl)
1371		rtnl_unlock();
1372	return err;
1373
1374e_inval:
1375	release_sock(sk);
1376	if (needs_rtnl)
1377		rtnl_unlock();
1378	return -EINVAL;
1379}
1380
1381/**
1382 * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1383 * @sk: socket
1384 * @skb: buffer
1385 *
1386 * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1387 * destination in skb->cb[] before dst drop.
1388 * This way, receiver doesn't make cache line misses to read rtable.
1389 */
1390void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1391{
1392	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1393	bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1394		       ipv6_sk_rxinfo(sk);
1395
1396	if (prepare && skb_rtable(skb)) {
1397		/* skb->cb is overloaded: prior to this point it is IP{6}CB
1398		 * which has interface index (iif) as the first member of the
1399		 * underlying inet{6}_skb_parm struct. This code then overlays
1400		 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
1401		 * element so the iif is picked up from the prior IPCB. If iif
1402		 * is the loopback interface, then return the sending interface
1403		 * (e.g., process binds socket to eth0 for Tx which is
1404		 * redirected to loopback in the rtable/dst).
1405		 */
1406		struct rtable *rt = skb_rtable(skb);
1407		bool l3slave = ipv4_l3mdev_skb(IPCB(skb)->flags);
1408
1409		if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
1410			pktinfo->ipi_ifindex = inet_iif(skb);
1411		else if (l3slave && rt && rt->rt_iif)
1412			pktinfo->ipi_ifindex = rt->rt_iif;
1413
1414		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1415	} else {
1416		pktinfo->ipi_ifindex = 0;
1417		pktinfo->ipi_spec_dst.s_addr = 0;
1418	}
1419	skb_dst_drop(skb);
1420}
1421
1422int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
1423		unsigned int optlen)
1424{
1425	int err;
1426
1427	if (level != SOL_IP)
1428		return -ENOPROTOOPT;
1429
1430	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1431#if IS_ENABLED(CONFIG_BPFILTER_UMH)
1432	if (optname >= BPFILTER_IPT_SO_SET_REPLACE &&
1433	    optname < BPFILTER_IPT_SET_MAX)
1434		err = bpfilter_ip_set_sockopt(sk, optname, optval, optlen);
1435#endif
1436#ifdef CONFIG_NETFILTER
1437	/* we need to exclude all possible ENOPROTOOPTs except default case */
1438	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1439			optname != IP_IPSEC_POLICY &&
1440			optname != IP_XFRM_POLICY &&
1441			!ip_mroute_opt(optname))
1442		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1443#endif
1444	return err;
1445}
1446EXPORT_SYMBOL(ip_setsockopt);
1447
1448/*
1449 *	Get the options. Note for future reference. The GET of IP options gets
1450 *	the _received_ ones. The set sets the _sent_ ones.
1451 */
1452
1453static bool getsockopt_needs_rtnl(int optname)
1454{
1455	switch (optname) {
1456	case IP_MSFILTER:
1457	case MCAST_MSFILTER:
1458		return true;
1459	}
1460	return false;
1461}
1462
1463static int ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
1464		int __user *optlen, int len)
1465{
1466	const int size0 = offsetof(struct group_filter, gf_slist);
1467	struct group_filter __user *p = optval;
1468	struct group_filter gsf;
1469	int num;
1470	int err;
1471
1472	if (len < size0)
1473		return -EINVAL;
1474	if (copy_from_user(&gsf, p, size0))
1475		return -EFAULT;
1476
1477	num = gsf.gf_numsrc;
1478	err = ip_mc_gsfget(sk, &gsf, p->gf_slist);
1479	if (err)
1480		return err;
1481	if (gsf.gf_numsrc < num)
1482		num = gsf.gf_numsrc;
1483	if (put_user(GROUP_FILTER_SIZE(num), optlen) ||
1484	    copy_to_user(p, &gsf, size0))
1485		return -EFAULT;
1486	return 0;
1487}
1488
1489static int compat_ip_get_mcast_msfilter(struct sock *sk, void __user *optval,
1490		int __user *optlen, int len)
1491{
1492	const int size0 = offsetof(struct compat_group_filter, gf_slist);
1493	struct compat_group_filter __user *p = optval;
1494	struct compat_group_filter gf32;
1495	struct group_filter gf;
1496	int num;
1497	int err;
1498
1499	if (len < size0)
1500		return -EINVAL;
1501	if (copy_from_user(&gf32, p, size0))
1502		return -EFAULT;
1503
1504	gf.gf_interface = gf32.gf_interface;
1505	gf.gf_fmode = gf32.gf_fmode;
1506	num = gf.gf_numsrc = gf32.gf_numsrc;
1507	gf.gf_group = gf32.gf_group;
1508
1509	err = ip_mc_gsfget(sk, &gf, p->gf_slist);
1510	if (err)
1511		return err;
1512	if (gf.gf_numsrc < num)
1513		num = gf.gf_numsrc;
1514	len = GROUP_FILTER_SIZE(num) - (sizeof(gf) - sizeof(gf32));
1515	if (put_user(len, optlen) ||
1516	    put_user(gf.gf_fmode, &p->gf_fmode) ||
1517	    put_user(gf.gf_numsrc, &p->gf_numsrc))
1518		return -EFAULT;
1519	return 0;
1520}
1521
1522static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1523			    char __user *optval, int __user *optlen)
1524{
1525	struct inet_sock *inet = inet_sk(sk);
1526	bool needs_rtnl = getsockopt_needs_rtnl(optname);
1527	int val, err = 0;
1528	int len;
1529
1530	if (level != SOL_IP)
1531		return -EOPNOTSUPP;
1532
1533	if (ip_mroute_opt(optname))
1534		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1535
1536	if (get_user(len, optlen))
1537		return -EFAULT;
1538	if (len < 0)
1539		return -EINVAL;
1540
1541	if (needs_rtnl)
1542		rtnl_lock();
1543	lock_sock(sk);
1544
1545	switch (optname) {
1546	case IP_OPTIONS:
1547	{
1548		unsigned char optbuf[sizeof(struct ip_options)+40];
1549		struct ip_options *opt = (struct ip_options *)optbuf;
1550		struct ip_options_rcu *inet_opt;
1551
1552		inet_opt = rcu_dereference_protected(inet->inet_opt,
1553						     lockdep_sock_is_held(sk));
1554		opt->optlen = 0;
1555		if (inet_opt)
1556			memcpy(optbuf, &inet_opt->opt,
1557			       sizeof(struct ip_options) +
1558			       inet_opt->opt.optlen);
1559		release_sock(sk);
1560
1561		if (opt->optlen == 0)
1562			return put_user(0, optlen);
1563
1564		ip_options_undo(opt);
1565
1566		len = min_t(unsigned int, len, opt->optlen);
1567		if (put_user(len, optlen))
1568			return -EFAULT;
1569		if (copy_to_user(optval, opt->__data, len))
1570			return -EFAULT;
1571		return 0;
1572	}
1573	case IP_PKTINFO:
1574		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1575		break;
1576	case IP_RECVTTL:
1577		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1578		break;
1579	case IP_RECVTOS:
1580		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1581		break;
1582	case IP_RECVOPTS:
1583		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1584		break;
1585	case IP_RETOPTS:
1586		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1587		break;
1588	case IP_PASSSEC:
1589		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1590		break;
1591	case IP_RECVORIGDSTADDR:
1592		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1593		break;
1594	case IP_CHECKSUM:
1595		val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1596		break;
1597	case IP_RECVFRAGSIZE:
1598		val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
1599		break;
1600	case IP_TOS:
1601		val = inet->tos;
1602		break;
1603	case IP_TTL:
1604	{
1605		struct net *net = sock_net(sk);
1606		val = (inet->uc_ttl == -1 ?
1607		       net->ipv4.sysctl_ip_default_ttl :
1608		       inet->uc_ttl);
1609		break;
1610	}
1611	case IP_HDRINCL:
1612		val = inet->hdrincl;
1613		break;
1614	case IP_NODEFRAG:
1615		val = inet->nodefrag;
1616		break;
1617	case IP_BIND_ADDRESS_NO_PORT:
1618		val = inet->bind_address_no_port;
1619		break;
1620	case IP_MTU_DISCOVER:
1621		val = inet->pmtudisc;
1622		break;
1623	case IP_MTU:
1624	{
1625		struct dst_entry *dst;
1626		val = 0;
1627		dst = sk_dst_get(sk);
1628		if (dst) {
1629			val = dst_mtu(dst);
1630			dst_release(dst);
1631		}
1632		if (!val) {
1633			release_sock(sk);
1634			return -ENOTCONN;
1635		}
1636		break;
1637	}
1638	case IP_RECVERR:
1639		val = inet->recverr;
1640		break;
1641	case IP_RECVERR_RFC4884:
1642		val = inet->recverr_rfc4884;
1643		break;
1644	case IP_MULTICAST_TTL:
1645		val = inet->mc_ttl;
1646		break;
1647	case IP_MULTICAST_LOOP:
1648		val = inet->mc_loop;
1649		break;
1650	case IP_UNICAST_IF:
1651		val = (__force int)htonl((__u32) inet->uc_index);
1652		break;
1653	case IP_MULTICAST_IF:
1654	{
1655		struct in_addr addr;
1656		len = min_t(unsigned int, len, sizeof(struct in_addr));
1657		addr.s_addr = inet->mc_addr;
1658		release_sock(sk);
1659
1660		if (put_user(len, optlen))
1661			return -EFAULT;
1662		if (copy_to_user(optval, &addr, len))
1663			return -EFAULT;
1664		return 0;
1665	}
1666	case IP_MSFILTER:
1667	{
1668		struct ip_msfilter msf;
1669
1670		if (len < IP_MSFILTER_SIZE(0)) {
1671			err = -EINVAL;
1672			goto out;
1673		}
1674		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1675			err = -EFAULT;
1676			goto out;
1677		}
1678		err = ip_mc_msfget(sk, &msf,
1679				   (struct ip_msfilter __user *)optval, optlen);
1680		goto out;
1681	}
1682	case MCAST_MSFILTER:
1683		if (in_compat_syscall())
1684			err = compat_ip_get_mcast_msfilter(sk, optval, optlen,
1685							   len);
1686		else
1687			err = ip_get_mcast_msfilter(sk, optval, optlen, len);
1688		goto out;
1689	case IP_MULTICAST_ALL:
1690		val = inet->mc_all;
1691		break;
1692	case IP_PKTOPTIONS:
1693	{
1694		struct msghdr msg;
1695
1696		release_sock(sk);
1697
1698		if (sk->sk_type != SOCK_STREAM)
1699			return -ENOPROTOOPT;
1700
1701		msg.msg_control_is_user = true;
1702		msg.msg_control_user = optval;
1703		msg.msg_controllen = len;
1704		msg.msg_flags = in_compat_syscall() ? MSG_CMSG_COMPAT : 0;
1705
1706		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1707			struct in_pktinfo info;
1708
1709			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1710			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1711			info.ipi_ifindex = inet->mc_index;
1712			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1713		}
1714		if (inet->cmsg_flags & IP_CMSG_TTL) {
1715			int hlim = inet->mc_ttl;
1716			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1717		}
1718		if (inet->cmsg_flags & IP_CMSG_TOS) {
1719			int tos = inet->rcv_tos;
1720			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1721		}
1722		len -= msg.msg_controllen;
1723		return put_user(len, optlen);
1724	}
1725	case IP_FREEBIND:
1726		val = inet->freebind;
1727		break;
1728	case IP_TRANSPARENT:
1729		val = inet->transparent;
1730		break;
1731	case IP_MINTTL:
1732		val = inet->min_ttl;
1733		break;
1734	case IP_PROTOCOL:
1735		val = inet_sk(sk)->inet_num;
1736		break;
1737	default:
1738		release_sock(sk);
1739		return -ENOPROTOOPT;
1740	}
1741	release_sock(sk);
1742
1743	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1744		unsigned char ucval = (unsigned char)val;
1745		len = 1;
1746		if (put_user(len, optlen))
1747			return -EFAULT;
1748		if (copy_to_user(optval, &ucval, 1))
1749			return -EFAULT;
1750	} else {
1751		len = min_t(unsigned int, sizeof(int), len);
1752		if (put_user(len, optlen))
1753			return -EFAULT;
1754		if (copy_to_user(optval, &val, len))
1755			return -EFAULT;
1756	}
1757	return 0;
1758
1759out:
1760	release_sock(sk);
1761	if (needs_rtnl)
1762		rtnl_unlock();
1763	return err;
1764}
1765
1766int ip_getsockopt(struct sock *sk, int level,
1767		  int optname, char __user *optval, int __user *optlen)
1768{
1769	int err;
1770
1771	err = do_ip_getsockopt(sk, level, optname, optval, optlen);
1772
1773#if IS_ENABLED(CONFIG_BPFILTER_UMH)
1774	if (optname >= BPFILTER_IPT_SO_GET_INFO &&
1775	    optname < BPFILTER_IPT_GET_MAX)
1776		err = bpfilter_ip_get_sockopt(sk, optname, optval, optlen);
1777#endif
1778#ifdef CONFIG_NETFILTER
1779	/* we need to exclude all possible ENOPROTOOPTs except default case */
1780	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1781			!ip_mroute_opt(optname)) {
1782		int len;
1783
1784		if (get_user(len, optlen))
1785			return -EFAULT;
1786
1787		err = nf_getsockopt(sk, PF_INET, optname, optval, &len);
1788		if (err >= 0)
1789			err = put_user(len, optlen);
1790		return err;
1791	}
1792#endif
1793	return err;
1794}
1795EXPORT_SYMBOL(ip_getsockopt);
1796