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/*
  51 *	SOL_IP control messages.
  52 */
  53
  54static void ip_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
  55{
  56	struct in_pktinfo info = *PKTINFO_SKB_CB(skb);
  57
  58	info.ipi_addr.s_addr = ip_hdr(skb)->daddr;
  59
  60	put_cmsg(msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
  61}
  62
  63static void ip_cmsg_recv_ttl(struct msghdr *msg, struct sk_buff *skb)
  64{
  65	int ttl = ip_hdr(skb)->ttl;
  66	put_cmsg(msg, SOL_IP, IP_TTL, sizeof(int), &ttl);
  67}
  68
  69static void ip_cmsg_recv_tos(struct msghdr *msg, struct sk_buff *skb)
  70{
  71	put_cmsg(msg, SOL_IP, IP_TOS, 1, &ip_hdr(skb)->tos);
  72}
  73
  74static void ip_cmsg_recv_opts(struct msghdr *msg, struct sk_buff *skb)
  75{
  76	if (IPCB(skb)->opt.optlen == 0)
  77		return;
  78
  79	put_cmsg(msg, SOL_IP, IP_RECVOPTS, IPCB(skb)->opt.optlen,
  80		 ip_hdr(skb) + 1);
  81}
  82
  83
  84static void ip_cmsg_recv_retopts(struct net *net, struct msghdr *msg,
  85				 struct sk_buff *skb)
  86{
  87	unsigned char optbuf[sizeof(struct ip_options) + 40];
  88	struct ip_options *opt = (struct ip_options *)optbuf;
  89
  90	if (IPCB(skb)->opt.optlen == 0)
  91		return;
  92
  93	if (ip_options_echo(net, opt, skb)) {
  94		msg->msg_flags |= MSG_CTRUNC;
  95		return;
  96	}
  97	ip_options_undo(opt);
  98
  99	put_cmsg(msg, SOL_IP, IP_RETOPTS, opt->optlen, opt->__data);
 100}
 101
 102static void ip_cmsg_recv_fragsize(struct msghdr *msg, struct sk_buff *skb)
 103{
 104	int val;
 105
 106	if (IPCB(skb)->frag_max_size == 0)
 107		return;
 108
 109	val = IPCB(skb)->frag_max_size;
 110	put_cmsg(msg, SOL_IP, IP_RECVFRAGSIZE, sizeof(val), &val);
 111}
 112
 113static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
 114				  int tlen, int offset)
 115{
 116	__wsum csum = skb->csum;
 117
 118	if (skb->ip_summed != CHECKSUM_COMPLETE)
 119		return;
 120
 121	if (offset != 0) {
 122		int tend_off = skb_transport_offset(skb) + tlen;
 123		csum = csum_sub(csum, skb_checksum(skb, tend_off, offset, 0));
 124	}
 125
 126	put_cmsg(msg, SOL_IP, IP_CHECKSUM, sizeof(__wsum), &csum);
 127}
 128
 129static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
 130{
 131	char *secdata;
 132	u32 seclen, secid;
 133	int err;
 134
 135	err = security_socket_getpeersec_dgram(NULL, skb, &secid);
 136	if (err)
 137		return;
 138
 139	err = security_secid_to_secctx(secid, &secdata, &seclen);
 140	if (err)
 141		return;
 142
 143	put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
 144	security_release_secctx(secdata, seclen);
 145}
 146
 147static void ip_cmsg_recv_dstaddr(struct msghdr *msg, struct sk_buff *skb)
 148{
 149	struct sockaddr_in sin;
 150	const struct iphdr *iph = ip_hdr(skb);
 151	__be16 *ports = (__be16 *)skb_transport_header(skb);
 152
 153	if (skb_transport_offset(skb) + 4 > (int)skb->len)
 154		return;
 155
 156	/* All current transport protocols have the port numbers in the
 157	 * first four bytes of the transport header and this function is
 158	 * written with this assumption in mind.
 159	 */
 160
 161	sin.sin_family = AF_INET;
 162	sin.sin_addr.s_addr = iph->daddr;
 163	sin.sin_port = ports[1];
 164	memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
 165
 166	put_cmsg(msg, SOL_IP, IP_ORIGDSTADDR, sizeof(sin), &sin);
 167}
 168
 169void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
 170			 struct sk_buff *skb, int tlen, int offset)
 171{
 172	struct inet_sock *inet = inet_sk(sk);
 173	unsigned int flags = inet->cmsg_flags;
 174
 175	/* Ordered by supposed usage frequency */
 176	if (flags & IP_CMSG_PKTINFO) {
 177		ip_cmsg_recv_pktinfo(msg, skb);
 178
 179		flags &= ~IP_CMSG_PKTINFO;
 180		if (!flags)
 181			return;
 182	}
 183
 184	if (flags & IP_CMSG_TTL) {
 185		ip_cmsg_recv_ttl(msg, skb);
 186
 187		flags &= ~IP_CMSG_TTL;
 188		if (!flags)
 189			return;
 190	}
 191
 192	if (flags & IP_CMSG_TOS) {
 193		ip_cmsg_recv_tos(msg, skb);
 194
 195		flags &= ~IP_CMSG_TOS;
 196		if (!flags)
 197			return;
 198	}
 199
 200	if (flags & IP_CMSG_RECVOPTS) {
 201		ip_cmsg_recv_opts(msg, skb);
 202
 203		flags &= ~IP_CMSG_RECVOPTS;
 204		if (!flags)
 205			return;
 206	}
 207
 208	if (flags & IP_CMSG_RETOPTS) {
 209		ip_cmsg_recv_retopts(sock_net(sk), msg, skb);
 210
 211		flags &= ~IP_CMSG_RETOPTS;
 212		if (!flags)
 213			return;
 214	}
 215
 216	if (flags & IP_CMSG_PASSSEC) {
 217		ip_cmsg_recv_security(msg, skb);
 218
 219		flags &= ~IP_CMSG_PASSSEC;
 220		if (!flags)
 221			return;
 222	}
 223
 224	if (flags & IP_CMSG_ORIGDSTADDR) {
 225		ip_cmsg_recv_dstaddr(msg, skb);
 226
 227		flags &= ~IP_CMSG_ORIGDSTADDR;
 228		if (!flags)
 229			return;
 230	}
 231
 232	if (flags & IP_CMSG_CHECKSUM)
 233		ip_cmsg_recv_checksum(msg, skb, tlen, offset);
 234
 235	if (flags & IP_CMSG_RECVFRAGSIZE)
 236		ip_cmsg_recv_fragsize(msg, skb);
 237}
 238EXPORT_SYMBOL(ip_cmsg_recv_offset);
 239
 240int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc,
 241		 bool allow_ipv6)
 242{
 243	int err, val;
 244	struct cmsghdr *cmsg;
 245	struct net *net = sock_net(sk);
 246
 247	for_each_cmsghdr(cmsg, msg) {
 248		if (!CMSG_OK(msg, cmsg))
 249			return -EINVAL;
 250#if IS_ENABLED(CONFIG_IPV6)
 251		if (allow_ipv6 &&
 252		    cmsg->cmsg_level == SOL_IPV6 &&
 253		    cmsg->cmsg_type == IPV6_PKTINFO) {
 254			struct in6_pktinfo *src_info;
 255
 256			if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info)))
 257				return -EINVAL;
 258			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 259			if (!ipv6_addr_v4mapped(&src_info->ipi6_addr))
 260				return -EINVAL;
 261			if (src_info->ipi6_ifindex)
 262				ipc->oif = src_info->ipi6_ifindex;
 263			ipc->addr = src_info->ipi6_addr.s6_addr32[3];
 264			continue;
 265		}
 266#endif
 267		if (cmsg->cmsg_level == SOL_SOCKET) {
 268			err = __sock_cmsg_send(sk, msg, cmsg, &ipc->sockc);
 269			if (err)
 270				return err;
 271			continue;
 272		}
 273
 274		if (cmsg->cmsg_level != SOL_IP)
 275			continue;
 276		switch (cmsg->cmsg_type) {
 277		case IP_RETOPTS:
 278			err = cmsg->cmsg_len - sizeof(struct cmsghdr);
 279
 280			/* Our caller is responsible for freeing ipc->opt */
 281			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
 282					     err < 40 ? err : 40);
 283			if (err)
 284				return err;
 285			break;
 286		case IP_PKTINFO:
 287		{
 288			struct in_pktinfo *info;
 289			if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo)))
 290				return -EINVAL;
 291			info = (struct in_pktinfo *)CMSG_DATA(cmsg);
 292			if (info->ipi_ifindex)
 293				ipc->oif = info->ipi_ifindex;
 294			ipc->addr = info->ipi_spec_dst.s_addr;
 295			break;
 296		}
 297		case IP_TTL:
 298			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 299				return -EINVAL;
 300			val = *(int *)CMSG_DATA(cmsg);
 301			if (val < 1 || val > 255)
 302				return -EINVAL;
 303			ipc->ttl = val;
 304			break;
 305		case IP_TOS:
 306			if (cmsg->cmsg_len == CMSG_LEN(sizeof(int)))
 307				val = *(int *)CMSG_DATA(cmsg);
 308			else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8)))
 309				val = *(u8 *)CMSG_DATA(cmsg);
 310			else
 311				return -EINVAL;
 312			if (val < 0 || val > 255)
 313				return -EINVAL;
 314			ipc->tos = val;
 315			ipc->priority = rt_tos2priority(ipc->tos);
 316			break;
 317
 318		default:
 319			return -EINVAL;
 320		}
 321	}
 322	return 0;
 323}
 324
 325static void ip_ra_destroy_rcu(struct rcu_head *head)
 326{
 327	struct ip_ra_chain *ra = container_of(head, struct ip_ra_chain, rcu);
 328
 329	sock_put(ra->saved_sk);
 330	kfree(ra);
 331}
 332
 333int ip_ra_control(struct sock *sk, unsigned char on,
 334		  void (*destructor)(struct sock *))
 335{
 336	struct ip_ra_chain *ra, *new_ra;
 337	struct ip_ra_chain __rcu **rap;
 338	struct net *net = sock_net(sk);
 339
 340	if (sk->sk_type != SOCK_RAW || inet_sk(sk)->inet_num == IPPROTO_RAW)
 341		return -EINVAL;
 342
 343	new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
 344
 345	mutex_lock(&net->ipv4.ra_mutex);
 346	for (rap = &net->ipv4.ra_chain;
 347	     (ra = rcu_dereference_protected(*rap,
 348			lockdep_is_held(&net->ipv4.ra_mutex))) != NULL;
 349	     rap = &ra->next) {
 350		if (ra->sk == sk) {
 351			if (on) {
 352				mutex_unlock(&net->ipv4.ra_mutex);
 353				kfree(new_ra);
 354				return -EADDRINUSE;
 355			}
 356			/* dont let ip_call_ra_chain() use sk again */
 357			ra->sk = NULL;
 358			RCU_INIT_POINTER(*rap, ra->next);
 359			mutex_unlock(&net->ipv4.ra_mutex);
 360
 361			if (ra->destructor)
 362				ra->destructor(sk);
 363			/*
 364			 * Delay sock_put(sk) and kfree(ra) after one rcu grace
 365			 * period. This guarantee ip_call_ra_chain() dont need
 366			 * to mess with socket refcounts.
 367			 */
 368			ra->saved_sk = sk;
 369			call_rcu(&ra->rcu, ip_ra_destroy_rcu);
 370			return 0;
 371		}
 372	}
 373	if (!new_ra) {
 374		mutex_unlock(&net->ipv4.ra_mutex);
 375		return -ENOBUFS;
 376	}
 377	new_ra->sk = sk;
 378	new_ra->destructor = destructor;
 379
 380	RCU_INIT_POINTER(new_ra->next, ra);
 381	rcu_assign_pointer(*rap, new_ra);
 382	sock_hold(sk);
 383	mutex_unlock(&net->ipv4.ra_mutex);
 384
 385	return 0;
 386}
 387
 388void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 389		   __be16 port, u32 info, u8 *payload)
 390{
 391	struct sock_exterr_skb *serr;
 392
 393	skb = skb_clone(skb, GFP_ATOMIC);
 394	if (!skb)
 395		return;
 396
 397	serr = SKB_EXT_ERR(skb);
 398	serr->ee.ee_errno = err;
 399	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP;
 400	serr->ee.ee_type = icmp_hdr(skb)->type;
 401	serr->ee.ee_code = icmp_hdr(skb)->code;
 402	serr->ee.ee_pad = 0;
 403	serr->ee.ee_info = info;
 404	serr->ee.ee_data = 0;
 405	serr->addr_offset = (u8 *)&(((struct iphdr *)(icmp_hdr(skb) + 1))->daddr) -
 406				   skb_network_header(skb);
 407	serr->port = port;
 408
 409	if (skb_pull(skb, payload - skb->data)) {
 410		skb_reset_transport_header(skb);
 411		if (sock_queue_err_skb(sk, skb) == 0)
 412			return;
 413	}
 414	kfree_skb(skb);
 415}
 416
 417void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 port, u32 info)
 418{
 419	struct inet_sock *inet = inet_sk(sk);
 420	struct sock_exterr_skb *serr;
 421	struct iphdr *iph;
 422	struct sk_buff *skb;
 423
 424	if (!inet->recverr)
 425		return;
 426
 427	skb = alloc_skb(sizeof(struct iphdr), GFP_ATOMIC);
 428	if (!skb)
 429		return;
 430
 431	skb_put(skb, sizeof(struct iphdr));
 432	skb_reset_network_header(skb);
 433	iph = ip_hdr(skb);
 434	iph->daddr = daddr;
 435
 436	serr = SKB_EXT_ERR(skb);
 437	serr->ee.ee_errno = err;
 438	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 439	serr->ee.ee_type = 0;
 440	serr->ee.ee_code = 0;
 441	serr->ee.ee_pad = 0;
 442	serr->ee.ee_info = info;
 443	serr->ee.ee_data = 0;
 444	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 445	serr->port = port;
 446
 447	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 448	skb_reset_transport_header(skb);
 449
 450	if (sock_queue_err_skb(sk, skb))
 451		kfree_skb(skb);
 452}
 453
 454/* For some errors we have valid addr_offset even with zero payload and
 455 * zero port. Also, addr_offset should be supported if port is set.
 456 */
 457static inline bool ipv4_datagram_support_addr(struct sock_exterr_skb *serr)
 458{
 459	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 460	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 461}
 462
 463/* IPv4 supports cmsg on all imcp errors and some timestamps
 464 *
 465 * Timestamp code paths do not initialize the fields expected by cmsg:
 466 * the PKTINFO fields in skb->cb[]. Fill those in here.
 467 */
 468static bool ipv4_datagram_support_cmsg(const struct sock *sk,
 469				       struct sk_buff *skb,
 470				       int ee_origin)
 471{
 472	struct in_pktinfo *info;
 473
 474	if (ee_origin == SO_EE_ORIGIN_ICMP)
 475		return true;
 476
 477	if (ee_origin == SO_EE_ORIGIN_LOCAL)
 478		return false;
 479
 480	/* Support IP_PKTINFO on tstamp packets if requested, to correlate
 481	 * timestamp with egress dev. Not possible for packets without iif
 482	 * or without payload (SOF_TIMESTAMPING_OPT_TSONLY).
 483	 */
 484	info = PKTINFO_SKB_CB(skb);
 485	if (!(sk->sk_tsflags & SOF_TIMESTAMPING_OPT_CMSG) ||
 486	    !info->ipi_ifindex)
 487		return false;
 488
 489	info->ipi_spec_dst.s_addr = ip_hdr(skb)->saddr;
 490	return true;
 491}
 492
 493/*
 494 *	Handle MSG_ERRQUEUE
 495 */
 496int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 497{
 498	struct sock_exterr_skb *serr;
 499	struct sk_buff *skb;
 500	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
 501	struct {
 502		struct sock_extended_err ee;
 503		struct sockaddr_in	 offender;
 504	} errhdr;
 505	int err;
 506	int copied;
 507
 508	err = -EAGAIN;
 509	skb = sock_dequeue_err_skb(sk);
 510	if (!skb)
 511		goto out;
 512
 513	copied = skb->len;
 514	if (copied > len) {
 515		msg->msg_flags |= MSG_TRUNC;
 516		copied = len;
 517	}
 518	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 519	if (unlikely(err)) {
 520		kfree_skb(skb);
 521		return err;
 522	}
 523	sock_recv_timestamp(msg, sk, skb);
 524
 525	serr = SKB_EXT_ERR(skb);
 526
 527	if (sin && ipv4_datagram_support_addr(serr)) {
 528		sin->sin_family = AF_INET;
 529		sin->sin_addr.s_addr = *(__be32 *)(skb_network_header(skb) +
 530						   serr->addr_offset);
 531		sin->sin_port = serr->port;
 532		memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
 533		*addr_len = sizeof(*sin);
 534	}
 535
 536	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 537	sin = &errhdr.offender;
 538	memset(sin, 0, sizeof(*sin));
 539
 540	if (ipv4_datagram_support_cmsg(sk, skb, serr->ee.ee_origin)) {
 541		sin->sin_family = AF_INET;
 542		sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
 543		if (inet_sk(sk)->cmsg_flags)
 544			ip_cmsg_recv(msg, skb);
 545	}
 546
 547	put_cmsg(msg, SOL_IP, IP_RECVERR, sizeof(errhdr), &errhdr);
 548
 549	/* Now we could try to dump offended packet options */
 550
 551	msg->msg_flags |= MSG_ERRQUEUE;
 552	err = copied;
 553
 554	consume_skb(skb);
 555out:
 556	return err;
 557}
 558
 559
 560/*
 561 *	Socket option code for IP. This is the end of the line after any
 562 *	TCP,UDP etc options on an IP socket.
 563 */
 564static bool setsockopt_needs_rtnl(int optname)
 565{
 566	switch (optname) {
 567	case IP_ADD_MEMBERSHIP:
 568	case IP_ADD_SOURCE_MEMBERSHIP:
 569	case IP_BLOCK_SOURCE:
 570	case IP_DROP_MEMBERSHIP:
 571	case IP_DROP_SOURCE_MEMBERSHIP:
 572	case IP_MSFILTER:
 573	case IP_UNBLOCK_SOURCE:
 574	case MCAST_BLOCK_SOURCE:
 575	case MCAST_MSFILTER:
 576	case MCAST_JOIN_GROUP:
 577	case MCAST_JOIN_SOURCE_GROUP:
 578	case MCAST_LEAVE_GROUP:
 579	case MCAST_LEAVE_SOURCE_GROUP:
 580	case MCAST_UNBLOCK_SOURCE:
 581		return true;
 582	}
 583	return false;
 584}
 585
 586static int do_ip_setsockopt(struct sock *sk, int level,
 587			    int optname, char __user *optval, unsigned int optlen)
 588{
 589	struct inet_sock *inet = inet_sk(sk);
 590	struct net *net = sock_net(sk);
 591	int val = 0, err;
 592	bool needs_rtnl = setsockopt_needs_rtnl(optname);
 593
 594	switch (optname) {
 595	case IP_PKTINFO:
 596	case IP_RECVTTL:
 597	case IP_RECVOPTS:
 598	case IP_RECVTOS:
 599	case IP_RETOPTS:
 600	case IP_TOS:
 601	case IP_TTL:
 602	case IP_HDRINCL:
 603	case IP_MTU_DISCOVER:
 604	case IP_RECVERR:
 605	case IP_ROUTER_ALERT:
 606	case IP_FREEBIND:
 607	case IP_PASSSEC:
 608	case IP_TRANSPARENT:
 609	case IP_MINTTL:
 610	case IP_NODEFRAG:
 611	case IP_BIND_ADDRESS_NO_PORT:
 612	case IP_UNICAST_IF:
 613	case IP_MULTICAST_TTL:
 614	case IP_MULTICAST_ALL:
 615	case IP_MULTICAST_LOOP:
 616	case IP_RECVORIGDSTADDR:
 617	case IP_CHECKSUM:
 618	case IP_RECVFRAGSIZE:
 619		if (optlen >= sizeof(int)) {
 620			if (get_user(val, (int __user *) optval))
 621				return -EFAULT;
 622		} else if (optlen >= sizeof(char)) {
 623			unsigned char ucval;
 624
 625			if (get_user(ucval, (unsigned char __user *) optval))
 626				return -EFAULT;
 627			val = (int) ucval;
 628		}
 629	}
 630
 631	/* If optlen==0, it is equivalent to val == 0 */
 632
 633	if (optname == IP_ROUTER_ALERT)
 634		return ip_ra_control(sk, val ? 1 : 0, NULL);
 635	if (ip_mroute_opt(optname))
 636		return ip_mroute_setsockopt(sk, optname, optval, optlen);
 637
 638	err = 0;
 639	if (needs_rtnl)
 640		rtnl_lock();
 641	lock_sock(sk);
 642
 643	switch (optname) {
 644	case IP_OPTIONS:
 645	{
 646		struct ip_options_rcu *old, *opt = NULL;
 647
 648		if (optlen > 40)
 649			goto e_inval;
 650		err = ip_options_get_from_user(sock_net(sk), &opt,
 651					       optval, optlen);
 652		if (err)
 653			break;
 654		old = rcu_dereference_protected(inet->inet_opt,
 655						lockdep_sock_is_held(sk));
 656		if (inet->is_icsk) {
 657			struct inet_connection_sock *icsk = inet_csk(sk);
 658#if IS_ENABLED(CONFIG_IPV6)
 659			if (sk->sk_family == PF_INET ||
 660			    (!((1 << sk->sk_state) &
 661			       (TCPF_LISTEN | TCPF_CLOSE)) &&
 662			     inet->inet_daddr != LOOPBACK4_IPV6)) {
 663#endif
 664				if (old)
 665					icsk->icsk_ext_hdr_len -= old->opt.optlen;
 666				if (opt)
 667					icsk->icsk_ext_hdr_len += opt->opt.optlen;
 668				icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
 669#if IS_ENABLED(CONFIG_IPV6)
 670			}
 671#endif
 672		}
 673		rcu_assign_pointer(inet->inet_opt, opt);
 674		if (old)
 675			kfree_rcu(old, rcu);
 676		break;
 677	}
 678	case IP_PKTINFO:
 679		if (val)
 680			inet->cmsg_flags |= IP_CMSG_PKTINFO;
 681		else
 682			inet->cmsg_flags &= ~IP_CMSG_PKTINFO;
 683		break;
 684	case IP_RECVTTL:
 685		if (val)
 686			inet->cmsg_flags |=  IP_CMSG_TTL;
 687		else
 688			inet->cmsg_flags &= ~IP_CMSG_TTL;
 689		break;
 690	case IP_RECVTOS:
 691		if (val)
 692			inet->cmsg_flags |=  IP_CMSG_TOS;
 693		else
 694			inet->cmsg_flags &= ~IP_CMSG_TOS;
 695		break;
 696	case IP_RECVOPTS:
 697		if (val)
 698			inet->cmsg_flags |=  IP_CMSG_RECVOPTS;
 699		else
 700			inet->cmsg_flags &= ~IP_CMSG_RECVOPTS;
 701		break;
 702	case IP_RETOPTS:
 703		if (val)
 704			inet->cmsg_flags |= IP_CMSG_RETOPTS;
 705		else
 706			inet->cmsg_flags &= ~IP_CMSG_RETOPTS;
 707		break;
 708	case IP_PASSSEC:
 709		if (val)
 710			inet->cmsg_flags |= IP_CMSG_PASSSEC;
 711		else
 712			inet->cmsg_flags &= ~IP_CMSG_PASSSEC;
 713		break;
 714	case IP_RECVORIGDSTADDR:
 715		if (val)
 716			inet->cmsg_flags |= IP_CMSG_ORIGDSTADDR;
 717		else
 718			inet->cmsg_flags &= ~IP_CMSG_ORIGDSTADDR;
 719		break;
 720	case IP_CHECKSUM:
 721		if (val) {
 722			if (!(inet->cmsg_flags & IP_CMSG_CHECKSUM)) {
 723				inet_inc_convert_csum(sk);
 724				inet->cmsg_flags |= IP_CMSG_CHECKSUM;
 725			}
 726		} else {
 727			if (inet->cmsg_flags & IP_CMSG_CHECKSUM) {
 728				inet_dec_convert_csum(sk);
 729				inet->cmsg_flags &= ~IP_CMSG_CHECKSUM;
 730			}
 731		}
 732		break;
 733	case IP_RECVFRAGSIZE:
 734		if (sk->sk_type != SOCK_RAW && sk->sk_type != SOCK_DGRAM)
 735			goto e_inval;
 736		if (val)
 737			inet->cmsg_flags |= IP_CMSG_RECVFRAGSIZE;
 738		else
 739			inet->cmsg_flags &= ~IP_CMSG_RECVFRAGSIZE;
 740		break;
 741	case IP_TOS:	/* This sets both TOS and Precedence */
 742		if (sk->sk_type == SOCK_STREAM) {
 743			val &= ~INET_ECN_MASK;
 744			val |= inet->tos & INET_ECN_MASK;
 745		}
 746		if (inet->tos != val) {
 747			inet->tos = val;
 748			sk->sk_priority = rt_tos2priority(val);
 749			sk_dst_reset(sk);
 750		}
 751		break;
 752	case IP_TTL:
 753		if (optlen < 1)
 754			goto e_inval;
 755		if (val != -1 && (val < 1 || val > 255))
 756			goto e_inval;
 757		inet->uc_ttl = val;
 758		break;
 759	case IP_HDRINCL:
 760		if (sk->sk_type != SOCK_RAW) {
 761			err = -ENOPROTOOPT;
 762			break;
 763		}
 764		inet->hdrincl = val ? 1 : 0;
 765		break;
 766	case IP_NODEFRAG:
 767		if (sk->sk_type != SOCK_RAW) {
 768			err = -ENOPROTOOPT;
 769			break;
 770		}
 771		inet->nodefrag = val ? 1 : 0;
 772		break;
 773	case IP_BIND_ADDRESS_NO_PORT:
 774		inet->bind_address_no_port = val ? 1 : 0;
 775		break;
 776	case IP_MTU_DISCOVER:
 777		if (val < IP_PMTUDISC_DONT || val > IP_PMTUDISC_OMIT)
 778			goto e_inval;
 779		inet->pmtudisc = val;
 780		break;
 781	case IP_RECVERR:
 782		inet->recverr = !!val;
 783		if (!val)
 784			skb_queue_purge(&sk->sk_error_queue);
 785		break;
 786	case IP_MULTICAST_TTL:
 787		if (sk->sk_type == SOCK_STREAM)
 788			goto e_inval;
 789		if (optlen < 1)
 790			goto e_inval;
 791		if (val == -1)
 792			val = 1;
 793		if (val < 0 || val > 255)
 794			goto e_inval;
 795		inet->mc_ttl = val;
 796		break;
 797	case IP_MULTICAST_LOOP:
 798		if (optlen < 1)
 799			goto e_inval;
 800		inet->mc_loop = !!val;
 801		break;
 802	case IP_UNICAST_IF:
 803	{
 804		struct net_device *dev = NULL;
 805		int ifindex;
 806		int midx;
 807
 808		if (optlen != sizeof(int))
 809			goto e_inval;
 810
 811		ifindex = (__force int)ntohl((__force __be32)val);
 812		if (ifindex == 0) {
 813			inet->uc_index = 0;
 814			err = 0;
 815			break;
 816		}
 817
 818		dev = dev_get_by_index(sock_net(sk), ifindex);
 819		err = -EADDRNOTAVAIL;
 820		if (!dev)
 821			break;
 822
 823		midx = l3mdev_master_ifindex(dev);
 824		dev_put(dev);
 825
 826		err = -EINVAL;
 827		if (sk->sk_bound_dev_if &&
 828		    (!midx || midx != sk->sk_bound_dev_if))
 829			break;
 830
 831		inet->uc_index = ifindex;
 832		err = 0;
 833		break;
 834	}
 835	case IP_MULTICAST_IF:
 836	{
 837		struct ip_mreqn mreq;
 838		struct net_device *dev = NULL;
 839		int midx;
 840
 841		if (sk->sk_type == SOCK_STREAM)
 842			goto e_inval;
 843		/*
 844		 *	Check the arguments are allowable
 845		 */
 846
 847		if (optlen < sizeof(struct in_addr))
 848			goto e_inval;
 849
 850		err = -EFAULT;
 851		if (optlen >= sizeof(struct ip_mreqn)) {
 852			if (copy_from_user(&mreq, optval, sizeof(mreq)))
 853				break;
 854		} else {
 855			memset(&mreq, 0, sizeof(mreq));
 856			if (optlen >= sizeof(struct ip_mreq)) {
 857				if (copy_from_user(&mreq, optval,
 858						   sizeof(struct ip_mreq)))
 859					break;
 860			} else if (optlen >= sizeof(struct in_addr)) {
 861				if (copy_from_user(&mreq.imr_address, optval,
 862						   sizeof(struct in_addr)))
 863					break;
 864			}
 865		}
 866
 867		if (!mreq.imr_ifindex) {
 868			if (mreq.imr_address.s_addr == htonl(INADDR_ANY)) {
 869				inet->mc_index = 0;
 870				inet->mc_addr  = 0;
 871				err = 0;
 872				break;
 873			}
 874			dev = ip_dev_find(sock_net(sk), mreq.imr_address.s_addr);
 875			if (dev)
 876				mreq.imr_ifindex = dev->ifindex;
 877		} else
 878			dev = dev_get_by_index(sock_net(sk), mreq.imr_ifindex);
 879
 880
 881		err = -EADDRNOTAVAIL;
 882		if (!dev)
 883			break;
 884
 885		midx = l3mdev_master_ifindex(dev);
 886
 887		dev_put(dev);
 888
 889		err = -EINVAL;
 890		if (sk->sk_bound_dev_if &&
 891		    mreq.imr_ifindex != sk->sk_bound_dev_if &&
 892		    (!midx || midx != sk->sk_bound_dev_if))
 893			break;
 894
 895		inet->mc_index = mreq.imr_ifindex;
 896		inet->mc_addr  = mreq.imr_address.s_addr;
 897		err = 0;
 898		break;
 899	}
 900
 901	case IP_ADD_MEMBERSHIP:
 902	case IP_DROP_MEMBERSHIP:
 903	{
 904		struct ip_mreqn mreq;
 905
 906		err = -EPROTO;
 907		if (inet_sk(sk)->is_icsk)
 908			break;
 909
 910		if (optlen < sizeof(struct ip_mreq))
 911			goto e_inval;
 912		err = -EFAULT;
 913		if (optlen >= sizeof(struct ip_mreqn)) {
 914			if (copy_from_user(&mreq, optval, sizeof(mreq)))
 915				break;
 916		} else {
 917			memset(&mreq, 0, sizeof(mreq));
 918			if (copy_from_user(&mreq, optval, sizeof(struct ip_mreq)))
 919				break;
 920		}
 921
 922		if (optname == IP_ADD_MEMBERSHIP)
 923			err = ip_mc_join_group(sk, &mreq);
 924		else
 925			err = ip_mc_leave_group(sk, &mreq);
 926		break;
 927	}
 928	case IP_MSFILTER:
 929	{
 930		struct ip_msfilter *msf;
 931
 932		if (optlen < IP_MSFILTER_SIZE(0))
 933			goto e_inval;
 934		if (optlen > sysctl_optmem_max) {
 935			err = -ENOBUFS;
 936			break;
 937		}
 938		msf = memdup_user(optval, optlen);
 939		if (IS_ERR(msf)) {
 940			err = PTR_ERR(msf);
 941			break;
 942		}
 943		/* numsrc >= (1G-4) overflow in 32 bits */
 944		if (msf->imsf_numsrc >= 0x3ffffffcU ||
 945		    msf->imsf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
 946			kfree(msf);
 947			err = -ENOBUFS;
 948			break;
 949		}
 950		if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) {
 951			kfree(msf);
 952			err = -EINVAL;
 953			break;
 954		}
 955		err = ip_mc_msfilter(sk, msf, 0);
 956		kfree(msf);
 957		break;
 958	}
 959	case IP_BLOCK_SOURCE:
 960	case IP_UNBLOCK_SOURCE:
 961	case IP_ADD_SOURCE_MEMBERSHIP:
 962	case IP_DROP_SOURCE_MEMBERSHIP:
 963	{
 964		struct ip_mreq_source mreqs;
 965		int omode, add;
 966
 967		if (optlen != sizeof(struct ip_mreq_source))
 968			goto e_inval;
 969		if (copy_from_user(&mreqs, optval, sizeof(mreqs))) {
 970			err = -EFAULT;
 971			break;
 972		}
 973		if (optname == IP_BLOCK_SOURCE) {
 974			omode = MCAST_EXCLUDE;
 975			add = 1;
 976		} else if (optname == IP_UNBLOCK_SOURCE) {
 977			omode = MCAST_EXCLUDE;
 978			add = 0;
 979		} else if (optname == IP_ADD_SOURCE_MEMBERSHIP) {
 980			struct ip_mreqn mreq;
 981
 982			mreq.imr_multiaddr.s_addr = mreqs.imr_multiaddr;
 983			mreq.imr_address.s_addr = mreqs.imr_interface;
 984			mreq.imr_ifindex = 0;
 985			err = ip_mc_join_group(sk, &mreq);
 986			if (err && err != -EADDRINUSE)
 987				break;
 988			omode = MCAST_INCLUDE;
 989			add = 1;
 990		} else /* IP_DROP_SOURCE_MEMBERSHIP */ {
 991			omode = MCAST_INCLUDE;
 992			add = 0;
 993		}
 994		err = ip_mc_source(add, omode, sk, &mreqs, 0);
 995		break;
 996	}
 997	case MCAST_JOIN_GROUP:
 998	case MCAST_LEAVE_GROUP:
 999	{
1000		struct group_req greq;
1001		struct sockaddr_in *psin;
1002		struct ip_mreqn mreq;
1003
1004		if (optlen < sizeof(struct group_req))
1005			goto e_inval;
1006		err = -EFAULT;
1007		if (copy_from_user(&greq, optval, sizeof(greq)))
1008			break;
1009		psin = (struct sockaddr_in *)&greq.gr_group;
1010		if (psin->sin_family != AF_INET)
1011			goto e_inval;
1012		memset(&mreq, 0, sizeof(mreq));
1013		mreq.imr_multiaddr = psin->sin_addr;
1014		mreq.imr_ifindex = greq.gr_interface;
1015
1016		if (optname == MCAST_JOIN_GROUP)
1017			err = ip_mc_join_group(sk, &mreq);
1018		else
1019			err = ip_mc_leave_group(sk, &mreq);
1020		break;
1021	}
1022	case MCAST_JOIN_SOURCE_GROUP:
1023	case MCAST_LEAVE_SOURCE_GROUP:
1024	case MCAST_BLOCK_SOURCE:
1025	case MCAST_UNBLOCK_SOURCE:
1026	{
1027		struct group_source_req greqs;
1028		struct ip_mreq_source mreqs;
1029		struct sockaddr_in *psin;
1030		int omode, add;
1031
1032		if (optlen != sizeof(struct group_source_req))
1033			goto e_inval;
1034		if (copy_from_user(&greqs, optval, sizeof(greqs))) {
1035			err = -EFAULT;
1036			break;
1037		}
1038		if (greqs.gsr_group.ss_family != AF_INET ||
1039		    greqs.gsr_source.ss_family != AF_INET) {
1040			err = -EADDRNOTAVAIL;
1041			break;
1042		}
1043		psin = (struct sockaddr_in *)&greqs.gsr_group;
1044		mreqs.imr_multiaddr = psin->sin_addr.s_addr;
1045		psin = (struct sockaddr_in *)&greqs.gsr_source;
1046		mreqs.imr_sourceaddr = psin->sin_addr.s_addr;
1047		mreqs.imr_interface = 0; /* use index for mc_source */
1048
1049		if (optname == MCAST_BLOCK_SOURCE) {
1050			omode = MCAST_EXCLUDE;
1051			add = 1;
1052		} else if (optname == MCAST_UNBLOCK_SOURCE) {
1053			omode = MCAST_EXCLUDE;
1054			add = 0;
1055		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
1056			struct ip_mreqn mreq;
1057
1058			psin = (struct sockaddr_in *)&greqs.gsr_group;
1059			mreq.imr_multiaddr = psin->sin_addr;
1060			mreq.imr_address.s_addr = 0;
1061			mreq.imr_ifindex = greqs.gsr_interface;
1062			err = ip_mc_join_group(sk, &mreq);
1063			if (err && err != -EADDRINUSE)
1064				break;
1065			greqs.gsr_interface = mreq.imr_ifindex;
1066			omode = MCAST_INCLUDE;
1067			add = 1;
1068		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
1069			omode = MCAST_INCLUDE;
1070			add = 0;
1071		}
1072		err = ip_mc_source(add, omode, sk, &mreqs,
1073				   greqs.gsr_interface);
1074		break;
1075	}
1076	case MCAST_MSFILTER:
1077	{
1078		struct sockaddr_in *psin;
1079		struct ip_msfilter *msf = NULL;
1080		struct group_filter *gsf = NULL;
1081		int msize, i, ifindex;
1082
1083		if (optlen < GROUP_FILTER_SIZE(0))
1084			goto e_inval;
1085		if (optlen > sysctl_optmem_max) {
1086			err = -ENOBUFS;
1087			break;
1088		}
1089		gsf = memdup_user(optval, optlen);
1090		if (IS_ERR(gsf)) {
1091			err = PTR_ERR(gsf);
1092			break;
1093		}
1094
1095		/* numsrc >= (4G-140)/128 overflow in 32 bits */
1096		if (gsf->gf_numsrc >= 0x1ffffff ||
1097		    gsf->gf_numsrc > net->ipv4.sysctl_igmp_max_msf) {
1098			err = -ENOBUFS;
1099			goto mc_msf_out;
1100		}
1101		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
1102			err = -EINVAL;
1103			goto mc_msf_out;
1104		}
1105		msize = IP_MSFILTER_SIZE(gsf->gf_numsrc);
1106		msf = kmalloc(msize, GFP_KERNEL);
1107		if (!msf) {
1108			err = -ENOBUFS;
1109			goto mc_msf_out;
1110		}
1111		ifindex = gsf->gf_interface;
1112		psin = (struct sockaddr_in *)&gsf->gf_group;
1113		if (psin->sin_family != AF_INET) {
1114			err = -EADDRNOTAVAIL;
1115			goto mc_msf_out;
1116		}
1117		msf->imsf_multiaddr = psin->sin_addr.s_addr;
1118		msf->imsf_interface = 0;
1119		msf->imsf_fmode = gsf->gf_fmode;
1120		msf->imsf_numsrc = gsf->gf_numsrc;
1121		err = -EADDRNOTAVAIL;
1122		for (i = 0; i < gsf->gf_numsrc; ++i) {
1123			psin = (struct sockaddr_in *)&gsf->gf_slist[i];
1124
1125			if (psin->sin_family != AF_INET)
1126				goto mc_msf_out;
1127			msf->imsf_slist[i] = psin->sin_addr.s_addr;
1128		}
1129		kfree(gsf);
1130		gsf = NULL;
1131
1132		err = ip_mc_msfilter(sk, msf, ifindex);
1133mc_msf_out:
1134		kfree(msf);
1135		kfree(gsf);
1136		break;
1137	}
1138	case IP_MULTICAST_ALL:
1139		if (optlen < 1)
1140			goto e_inval;
1141		if (val != 0 && val != 1)
1142			goto e_inval;
1143		inet->mc_all = val;
1144		break;
1145
1146	case IP_FREEBIND:
1147		if (optlen < 1)
1148			goto e_inval;
1149		inet->freebind = !!val;
1150		break;
1151
1152	case IP_IPSEC_POLICY:
1153	case IP_XFRM_POLICY:
1154		err = -EPERM;
1155		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
1156			break;
1157		err = xfrm_user_policy(sk, optname, optval, optlen);
1158		break;
1159
1160	case IP_TRANSPARENT:
1161		if (!!val && !ns_capable(sock_net(sk)->user_ns, CAP_NET_RAW) &&
1162		    !ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) {
1163			err = -EPERM;
1164			break;
1165		}
1166		if (optlen < 1)
1167			goto e_inval;
1168		inet->transparent = !!val;
1169		break;
1170
1171	case IP_MINTTL:
1172		if (optlen < 1)
1173			goto e_inval;
1174		if (val < 0 || val > 255)
1175			goto e_inval;
1176		inet->min_ttl = val;
1177		break;
1178
1179	default:
1180		err = -ENOPROTOOPT;
1181		break;
1182	}
1183	release_sock(sk);
1184	if (needs_rtnl)
1185		rtnl_unlock();
1186	return err;
1187
1188e_inval:
1189	release_sock(sk);
1190	if (needs_rtnl)
1191		rtnl_unlock();
1192	return -EINVAL;
1193}
1194
1195/**
1196 * ipv4_pktinfo_prepare - transfer some info from rtable to skb
1197 * @sk: socket
1198 * @skb: buffer
1199 *
1200 * To support IP_CMSG_PKTINFO option, we store rt_iif and specific
1201 * destination in skb->cb[] before dst drop.
1202 * This way, receiver doesn't make cache line misses to read rtable.
1203 */
1204void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb)
1205{
1206	struct in_pktinfo *pktinfo = PKTINFO_SKB_CB(skb);
1207	bool prepare = (inet_sk(sk)->cmsg_flags & IP_CMSG_PKTINFO) ||
1208		       ipv6_sk_rxinfo(sk);
1209
1210	if (prepare && skb_rtable(skb)) {
1211		/* skb->cb is overloaded: prior to this point it is IP{6}CB
1212		 * which has interface index (iif) as the first member of the
1213		 * underlying inet{6}_skb_parm struct. This code then overlays
1214		 * PKTINFO_SKB_CB and in_pktinfo also has iif as the first
1215		 * element so the iif is picked up from the prior IPCB. If iif
1216		 * is the loopback interface, then return the sending interface
1217		 * (e.g., process binds socket to eth0 for Tx which is
1218		 * redirected to loopback in the rtable/dst).
1219		 */
1220		struct rtable *rt = skb_rtable(skb);
1221		bool l3slave = ipv4_l3mdev_skb(IPCB(skb)->flags);
1222
1223		if (pktinfo->ipi_ifindex == LOOPBACK_IFINDEX)
1224			pktinfo->ipi_ifindex = inet_iif(skb);
1225		else if (l3slave && rt && rt->rt_iif)
1226			pktinfo->ipi_ifindex = rt->rt_iif;
1227
1228		pktinfo->ipi_spec_dst.s_addr = fib_compute_spec_dst(skb);
1229	} else {
1230		pktinfo->ipi_ifindex = 0;
1231		pktinfo->ipi_spec_dst.s_addr = 0;
1232	}
1233	skb_dst_drop(skb);
1234}
1235
1236int ip_setsockopt(struct sock *sk, int level,
1237		int optname, char __user *optval, unsigned int optlen)
1238{
1239	int err;
1240
1241	if (level != SOL_IP)
1242		return -ENOPROTOOPT;
1243
1244	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1245#ifdef CONFIG_NETFILTER
1246	/* we need to exclude all possible ENOPROTOOPTs except default case */
1247	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1248			optname != IP_IPSEC_POLICY &&
1249			optname != IP_XFRM_POLICY &&
1250			!ip_mroute_opt(optname))
1251		err = nf_setsockopt(sk, PF_INET, optname, optval, optlen);
1252#endif
1253	return err;
1254}
1255EXPORT_SYMBOL(ip_setsockopt);
1256
1257#ifdef CONFIG_COMPAT
1258int compat_ip_setsockopt(struct sock *sk, int level, int optname,
1259			 char __user *optval, unsigned int optlen)
1260{
1261	int err;
1262
1263	if (level != SOL_IP)
1264		return -ENOPROTOOPT;
1265
1266	if (optname >= MCAST_JOIN_GROUP && optname <= MCAST_MSFILTER)
1267		return compat_mc_setsockopt(sk, level, optname, optval, optlen,
1268			ip_setsockopt);
1269
1270	err = do_ip_setsockopt(sk, level, optname, optval, optlen);
1271#ifdef CONFIG_NETFILTER
1272	/* we need to exclude all possible ENOPROTOOPTs except default case */
1273	if (err == -ENOPROTOOPT && optname != IP_HDRINCL &&
1274			optname != IP_IPSEC_POLICY &&
1275			optname != IP_XFRM_POLICY &&
1276			!ip_mroute_opt(optname))
1277		err = compat_nf_setsockopt(sk, PF_INET, optname, optval,
1278					   optlen);
1279#endif
1280	return err;
1281}
1282EXPORT_SYMBOL(compat_ip_setsockopt);
1283#endif
1284
1285/*
1286 *	Get the options. Note for future reference. The GET of IP options gets
1287 *	the _received_ ones. The set sets the _sent_ ones.
1288 */
1289
1290static bool getsockopt_needs_rtnl(int optname)
1291{
1292	switch (optname) {
1293	case IP_MSFILTER:
1294	case MCAST_MSFILTER:
1295		return true;
1296	}
1297	return false;
1298}
1299
1300static int do_ip_getsockopt(struct sock *sk, int level, int optname,
1301			    char __user *optval, int __user *optlen, unsigned int flags)
1302{
1303	struct inet_sock *inet = inet_sk(sk);
1304	bool needs_rtnl = getsockopt_needs_rtnl(optname);
1305	int val, err = 0;
1306	int len;
1307
1308	if (level != SOL_IP)
1309		return -EOPNOTSUPP;
1310
1311	if (ip_mroute_opt(optname))
1312		return ip_mroute_getsockopt(sk, optname, optval, optlen);
1313
1314	if (get_user(len, optlen))
1315		return -EFAULT;
1316	if (len < 0)
1317		return -EINVAL;
1318
1319	if (needs_rtnl)
1320		rtnl_lock();
1321	lock_sock(sk);
1322
1323	switch (optname) {
1324	case IP_OPTIONS:
1325	{
1326		unsigned char optbuf[sizeof(struct ip_options)+40];
1327		struct ip_options *opt = (struct ip_options *)optbuf;
1328		struct ip_options_rcu *inet_opt;
1329
1330		inet_opt = rcu_dereference_protected(inet->inet_opt,
1331						     lockdep_sock_is_held(sk));
1332		opt->optlen = 0;
1333		if (inet_opt)
1334			memcpy(optbuf, &inet_opt->opt,
1335			       sizeof(struct ip_options) +
1336			       inet_opt->opt.optlen);
1337		release_sock(sk);
1338
1339		if (opt->optlen == 0)
1340			return put_user(0, optlen);
1341
1342		ip_options_undo(opt);
1343
1344		len = min_t(unsigned int, len, opt->optlen);
1345		if (put_user(len, optlen))
1346			return -EFAULT;
1347		if (copy_to_user(optval, opt->__data, len))
1348			return -EFAULT;
1349		return 0;
1350	}
1351	case IP_PKTINFO:
1352		val = (inet->cmsg_flags & IP_CMSG_PKTINFO) != 0;
1353		break;
1354	case IP_RECVTTL:
1355		val = (inet->cmsg_flags & IP_CMSG_TTL) != 0;
1356		break;
1357	case IP_RECVTOS:
1358		val = (inet->cmsg_flags & IP_CMSG_TOS) != 0;
1359		break;
1360	case IP_RECVOPTS:
1361		val = (inet->cmsg_flags & IP_CMSG_RECVOPTS) != 0;
1362		break;
1363	case IP_RETOPTS:
1364		val = (inet->cmsg_flags & IP_CMSG_RETOPTS) != 0;
1365		break;
1366	case IP_PASSSEC:
1367		val = (inet->cmsg_flags & IP_CMSG_PASSSEC) != 0;
1368		break;
1369	case IP_RECVORIGDSTADDR:
1370		val = (inet->cmsg_flags & IP_CMSG_ORIGDSTADDR) != 0;
1371		break;
1372	case IP_CHECKSUM:
1373		val = (inet->cmsg_flags & IP_CMSG_CHECKSUM) != 0;
1374		break;
1375	case IP_RECVFRAGSIZE:
1376		val = (inet->cmsg_flags & IP_CMSG_RECVFRAGSIZE) != 0;
1377		break;
1378	case IP_TOS:
1379		val = inet->tos;
1380		break;
1381	case IP_TTL:
1382	{
1383		struct net *net = sock_net(sk);
1384		val = (inet->uc_ttl == -1 ?
1385		       net->ipv4.sysctl_ip_default_ttl :
1386		       inet->uc_ttl);
1387		break;
1388	}
1389	case IP_HDRINCL:
1390		val = inet->hdrincl;
1391		break;
1392	case IP_NODEFRAG:
1393		val = inet->nodefrag;
1394		break;
1395	case IP_BIND_ADDRESS_NO_PORT:
1396		val = inet->bind_address_no_port;
1397		break;
1398	case IP_MTU_DISCOVER:
1399		val = inet->pmtudisc;
1400		break;
1401	case IP_MTU:
1402	{
1403		struct dst_entry *dst;
1404		val = 0;
1405		dst = sk_dst_get(sk);
1406		if (dst) {
1407			val = dst_mtu(dst);
1408			dst_release(dst);
1409		}
1410		if (!val) {
1411			release_sock(sk);
1412			return -ENOTCONN;
1413		}
1414		break;
1415	}
1416	case IP_RECVERR:
1417		val = inet->recverr;
1418		break;
1419	case IP_MULTICAST_TTL:
1420		val = inet->mc_ttl;
1421		break;
1422	case IP_MULTICAST_LOOP:
1423		val = inet->mc_loop;
1424		break;
1425	case IP_UNICAST_IF:
1426		val = (__force int)htonl((__u32) inet->uc_index);
1427		break;
1428	case IP_MULTICAST_IF:
1429	{
1430		struct in_addr addr;
1431		len = min_t(unsigned int, len, sizeof(struct in_addr));
1432		addr.s_addr = inet->mc_addr;
1433		release_sock(sk);
1434
1435		if (put_user(len, optlen))
1436			return -EFAULT;
1437		if (copy_to_user(optval, &addr, len))
1438			return -EFAULT;
1439		return 0;
1440	}
1441	case IP_MSFILTER:
1442	{
1443		struct ip_msfilter msf;
1444
1445		if (len < IP_MSFILTER_SIZE(0)) {
1446			err = -EINVAL;
1447			goto out;
1448		}
1449		if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) {
1450			err = -EFAULT;
1451			goto out;
1452		}
1453		err = ip_mc_msfget(sk, &msf,
1454				   (struct ip_msfilter __user *)optval, optlen);
1455		goto out;
1456	}
1457	case MCAST_MSFILTER:
1458	{
1459		struct group_filter gsf;
1460
1461		if (len < GROUP_FILTER_SIZE(0)) {
1462			err = -EINVAL;
1463			goto out;
1464		}
1465		if (copy_from_user(&gsf, optval, GROUP_FILTER_SIZE(0))) {
1466			err = -EFAULT;
1467			goto out;
1468		}
1469		err = ip_mc_gsfget(sk, &gsf,
1470				   (struct group_filter __user *)optval,
1471				   optlen);
1472		goto out;
1473	}
1474	case IP_MULTICAST_ALL:
1475		val = inet->mc_all;
1476		break;
1477	case IP_PKTOPTIONS:
1478	{
1479		struct msghdr msg;
1480
1481		release_sock(sk);
1482
1483		if (sk->sk_type != SOCK_STREAM)
1484			return -ENOPROTOOPT;
1485
1486		msg.msg_control = (__force void *) optval;
1487		msg.msg_controllen = len;
1488		msg.msg_flags = flags;
1489
1490		if (inet->cmsg_flags & IP_CMSG_PKTINFO) {
1491			struct in_pktinfo info;
1492
1493			info.ipi_addr.s_addr = inet->inet_rcv_saddr;
1494			info.ipi_spec_dst.s_addr = inet->inet_rcv_saddr;
1495			info.ipi_ifindex = inet->mc_index;
1496			put_cmsg(&msg, SOL_IP, IP_PKTINFO, sizeof(info), &info);
1497		}
1498		if (inet->cmsg_flags & IP_CMSG_TTL) {
1499			int hlim = inet->mc_ttl;
1500			put_cmsg(&msg, SOL_IP, IP_TTL, sizeof(hlim), &hlim);
1501		}
1502		if (inet->cmsg_flags & IP_CMSG_TOS) {
1503			int tos = inet->rcv_tos;
1504			put_cmsg(&msg, SOL_IP, IP_TOS, sizeof(tos), &tos);
1505		}
1506		len -= msg.msg_controllen;
1507		return put_user(len, optlen);
1508	}
1509	case IP_FREEBIND:
1510		val = inet->freebind;
1511		break;
1512	case IP_TRANSPARENT:
1513		val = inet->transparent;
1514		break;
1515	case IP_MINTTL:
1516		val = inet->min_ttl;
1517		break;
1518	default:
1519		release_sock(sk);
1520		return -ENOPROTOOPT;
1521	}
1522	release_sock(sk);
1523
1524	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {
1525		unsigned char ucval = (unsigned char)val;
1526		len = 1;
1527		if (put_user(len, optlen))
1528			return -EFAULT;
1529		if (copy_to_user(optval, &ucval, 1))
1530			return -EFAULT;
1531	} else {
1532		len = min_t(unsigned int, sizeof(int), len);
1533		if (put_user(len, optlen))
1534			return -EFAULT;
1535		if (copy_to_user(optval, &val, len))
1536			return -EFAULT;
1537	}
1538	return 0;
1539
1540out:
1541	release_sock(sk);
1542	if (needs_rtnl)
1543		rtnl_unlock();
1544	return err;
1545}
1546
1547int ip_getsockopt(struct sock *sk, int level,
1548		  int optname, char __user *optval, int __user *optlen)
1549{
1550	int err;
1551
1552	err = do_ip_getsockopt(sk, level, optname, optval, optlen, 0);
1553#ifdef CONFIG_NETFILTER
1554	/* we need to exclude all possible ENOPROTOOPTs except default case */
1555	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1556			!ip_mroute_opt(optname)) {
1557		int len;
1558
1559		if (get_user(len, optlen))
1560			return -EFAULT;
1561
1562		err = nf_getsockopt(sk, PF_INET, optname, optval, &len);
1563		if (err >= 0)
1564			err = put_user(len, optlen);
1565		return err;
1566	}
1567#endif
1568	return err;
1569}
1570EXPORT_SYMBOL(ip_getsockopt);
1571
1572#ifdef CONFIG_COMPAT
1573int compat_ip_getsockopt(struct sock *sk, int level, int optname,
1574			 char __user *optval, int __user *optlen)
1575{
1576	int err;
1577
1578	if (optname == MCAST_MSFILTER)
1579		return compat_mc_getsockopt(sk, level, optname, optval, optlen,
1580			ip_getsockopt);
1581
1582	err = do_ip_getsockopt(sk, level, optname, optval, optlen,
1583		MSG_CMSG_COMPAT);
1584
1585#ifdef CONFIG_NETFILTER
1586	/* we need to exclude all possible ENOPROTOOPTs except default case */
1587	if (err == -ENOPROTOOPT && optname != IP_PKTOPTIONS &&
1588			!ip_mroute_opt(optname)) {
1589		int len;
1590
1591		if (get_user(len, optlen))
1592			return -EFAULT;
1593
1594		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
1595		if (err >= 0)
1596			err = put_user(len, optlen);
1597		return err;
1598	}
1599#endif
1600	return err;
1601}
1602EXPORT_SYMBOL(compat_ip_getsockopt);
1603#endif