1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *	common UDP/RAW code
   4 *	Linux INET6 implementation
   5 *
   6 *	Authors:
   7 *	Pedro Roque		<roque@di.fc.ul.pt>
   8 */
   9
  10#include <linux/capability.h>
  11#include <linux/errno.h>
  12#include <linux/types.h>
  13#include <linux/kernel.h>
  14#include <linux/interrupt.h>
  15#include <linux/socket.h>
  16#include <linux/sockios.h>
  17#include <linux/in6.h>
  18#include <linux/ipv6.h>
  19#include <linux/route.h>
  20#include <linux/slab.h>
  21#include <linux/export.h>
  22#include <linux/icmp.h>
  23
  24#include <net/ipv6.h>
  25#include <net/ndisc.h>
  26#include <net/addrconf.h>
  27#include <net/transp_v6.h>
  28#include <net/ip6_route.h>
  29#include <net/tcp_states.h>
  30#include <net/dsfield.h>
  31#include <net/sock_reuseport.h>
  32
  33#include <linux/errqueue.h>
  34#include <linux/uaccess.h>
  35
  36static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  37{
  38	return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  39}
  40
  41static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
 
  42{
  43	struct inet_sock *inet = inet_sk(sk);
  44	struct ipv6_pinfo *np = inet6_sk(sk);
  45	int oif = sk->sk_bound_dev_if;
  46
  47	memset(fl6, 0, sizeof(*fl6));
  48	fl6->flowi6_proto = sk->sk_protocol;
  49	fl6->daddr = sk->sk_v6_daddr;
  50	fl6->saddr = np->saddr;
  51	fl6->flowi6_mark = sk->sk_mark;
  52	fl6->fl6_dport = inet->inet_dport;
  53	fl6->fl6_sport = inet->inet_sport;
  54	fl6->flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
  55	fl6->flowi6_uid = sk->sk_uid;
  56
  57	if (!oif)
  58		oif = np->sticky_pktinfo.ipi6_ifindex;
  59
  60	if (!oif) {
  61		if (ipv6_addr_is_multicast(&fl6->daddr))
  62			oif = np->mcast_oif;
  63		else
  64			oif = np->ucast_oif;
  65	}
  66
  67	fl6->flowi6_oif = oif;
  68	security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));
  69}
  70
  71int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  72{
  73	struct ip6_flowlabel *flowlabel = NULL;
  74	struct in6_addr *final_p, final;
  75	struct ipv6_txoptions *opt;
  76	struct dst_entry *dst;
  77	struct inet_sock *inet = inet_sk(sk);
  78	struct ipv6_pinfo *np = inet6_sk(sk);
  79	struct flowi6 fl6;
  80	int err = 0;
  81
  82	if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
 
  83		flowlabel = fl6_sock_lookup(sk, np->flow_label);
  84		if (IS_ERR(flowlabel))
  85			return -EINVAL;
  86	}
  87	ip6_datagram_flow_key_init(&fl6, sk);
  88
  89	rcu_read_lock();
  90	opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  91	final_p = fl6_update_dst(&fl6, opt, &final);
  92	rcu_read_unlock();
  93
  94	dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
  95	if (IS_ERR(dst)) {
  96		err = PTR_ERR(dst);
  97		goto out;
  98	}
  99
 100	if (fix_sk_saddr) {
 101		if (ipv6_addr_any(&np->saddr))
 102			np->saddr = fl6.saddr;
 103
 104		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 105			sk->sk_v6_rcv_saddr = fl6.saddr;
 106			inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 107			if (sk->sk_prot->rehash)
 108				sk->sk_prot->rehash(sk);
 109		}
 110	}
 111
 112	ip6_sk_dst_store_flow(sk, dst, &fl6);
 113
 114out:
 115	fl6_sock_release(flowlabel);
 116	return err;
 117}
 118
 119void ip6_datagram_release_cb(struct sock *sk)
 120{
 121	struct dst_entry *dst;
 122
 123	if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 124		return;
 125
 126	rcu_read_lock();
 127	dst = __sk_dst_get(sk);
 128	if (!dst || !dst->obsolete ||
 129	    dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 130		rcu_read_unlock();
 131		return;
 132	}
 133	rcu_read_unlock();
 134
 135	ip6_datagram_dst_update(sk, false);
 136}
 137EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 138
 139int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 140			   int addr_len)
 141{
 142	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
 143	struct inet_sock	*inet = inet_sk(sk);
 144	struct ipv6_pinfo	*np = inet6_sk(sk);
 145	struct in6_addr		*daddr, old_daddr;
 146	__be32			fl6_flowlabel = 0;
 147	__be32			old_fl6_flowlabel;
 148	__be16			old_dport;
 149	int			addr_type;
 150	int			err;
 151
 152	if (usin->sin6_family == AF_INET) {
 153		if (ipv6_only_sock(sk))
 154			return -EAFNOSUPPORT;
 155		err = __ip4_datagram_connect(sk, uaddr, addr_len);
 156		goto ipv4_connected;
 157	}
 158
 159	if (addr_len < SIN6_LEN_RFC2133)
 160		return -EINVAL;
 161
 162	if (usin->sin6_family != AF_INET6)
 163		return -EAFNOSUPPORT;
 164
 165	if (np->sndflow)
 166		fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 167
 168	if (ipv6_addr_any(&usin->sin6_addr)) {
 169		/*
 170		 *	connect to self
 171		 */
 172		if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 173			ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 174					       &usin->sin6_addr);
 175		else
 176			usin->sin6_addr = in6addr_loopback;
 177	}
 178
 179	addr_type = ipv6_addr_type(&usin->sin6_addr);
 180
 181	daddr = &usin->sin6_addr;
 182
 183	if (addr_type & IPV6_ADDR_MAPPED) {
 184		struct sockaddr_in sin;
 185
 186		if (ipv6_only_sock(sk)) {
 187			err = -ENETUNREACH;
 188			goto out;
 189		}
 190		sin.sin_family = AF_INET;
 191		sin.sin_addr.s_addr = daddr->s6_addr32[3];
 192		sin.sin_port = usin->sin6_port;
 193
 194		err = __ip4_datagram_connect(sk,
 195					     (struct sockaddr *) &sin,
 196					     sizeof(sin));
 197
 198ipv4_connected:
 199		if (err)
 200			goto out;
 201
 202		ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 203
 204		if (ipv6_addr_any(&np->saddr) ||
 205		    ipv6_mapped_addr_any(&np->saddr))
 206			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 207
 208		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 209		    ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 210			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 211					       &sk->sk_v6_rcv_saddr);
 212			if (sk->sk_prot->rehash)
 213				sk->sk_prot->rehash(sk);
 214		}
 215
 216		goto out;
 217	}
 218
 219	if (__ipv6_addr_needs_scope_id(addr_type)) {
 220		if (addr_len >= sizeof(struct sockaddr_in6) &&
 221		    usin->sin6_scope_id) {
 222			if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
 223				err = -EINVAL;
 224				goto out;
 225			}
 226			WRITE_ONCE(sk->sk_bound_dev_if, usin->sin6_scope_id);
 227		}
 228
 229		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 230			WRITE_ONCE(sk->sk_bound_dev_if, np->mcast_oif);
 231
 232		/* Connect to link-local address requires an interface */
 233		if (!sk->sk_bound_dev_if) {
 234			err = -EINVAL;
 235			goto out;
 236		}
 237	}
 238
 239	/* save the current peer information before updating it */
 240	old_daddr = sk->sk_v6_daddr;
 241	old_fl6_flowlabel = np->flow_label;
 242	old_dport = inet->inet_dport;
 243
 244	sk->sk_v6_daddr = *daddr;
 245	np->flow_label = fl6_flowlabel;
 246	inet->inet_dport = usin->sin6_port;
 247
 248	/*
 249	 *	Check for a route to destination an obtain the
 250	 *	destination cache for it.
 251	 */
 252
 253	err = ip6_datagram_dst_update(sk, true);
 254	if (err) {
 255		/* Restore the socket peer info, to keep it consistent with
 256		 * the old socket state
 257		 */
 258		sk->sk_v6_daddr = old_daddr;
 259		np->flow_label = old_fl6_flowlabel;
 260		inet->inet_dport = old_dport;
 261		goto out;
 262	}
 263
 264	reuseport_has_conns_set(sk);
 265	sk->sk_state = TCP_ESTABLISHED;
 266	sk_set_txhash(sk);
 267out:
 268	return err;
 269}
 270EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 271
 272int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 273{
 274	int res;
 275
 276	lock_sock(sk);
 277	res = __ip6_datagram_connect(sk, uaddr, addr_len);
 278	release_sock(sk);
 279	return res;
 280}
 281EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 282
 283int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 284				 int addr_len)
 285{
 286	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 287	if (sin6->sin6_family != AF_INET6)
 288		return -EAFNOSUPPORT;
 289	return ip6_datagram_connect(sk, uaddr, addr_len);
 290}
 291EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 292
 293static void ipv6_icmp_error_rfc4884(const struct sk_buff *skb,
 294				    struct sock_ee_data_rfc4884 *out)
 295{
 296	switch (icmp6_hdr(skb)->icmp6_type) {
 297	case ICMPV6_TIME_EXCEED:
 298	case ICMPV6_DEST_UNREACH:
 299		ip_icmp_error_rfc4884(skb, out, sizeof(struct icmp6hdr),
 300				      icmp6_hdr(skb)->icmp6_datagram_len * 8);
 301	}
 302}
 303
 304void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 305		     __be16 port, u32 info, u8 *payload)
 306{
 307	struct ipv6_pinfo *np  = inet6_sk(sk);
 308	struct icmp6hdr *icmph = icmp6_hdr(skb);
 309	struct sock_exterr_skb *serr;
 310
 311	if (!np->recverr)
 312		return;
 313
 314	skb = skb_clone(skb, GFP_ATOMIC);
 315	if (!skb)
 316		return;
 317
 318	skb->protocol = htons(ETH_P_IPV6);
 319
 320	serr = SKB_EXT_ERR(skb);
 321	serr->ee.ee_errno = err;
 322	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 323	serr->ee.ee_type = icmph->icmp6_type;
 324	serr->ee.ee_code = icmph->icmp6_code;
 325	serr->ee.ee_pad = 0;
 326	serr->ee.ee_info = info;
 327	serr->ee.ee_data = 0;
 328	serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 329				  skb_network_header(skb);
 330	serr->port = port;
 331
 332	__skb_pull(skb, payload - skb->data);
 333
 334	if (inet6_sk(sk)->recverr_rfc4884)
 335		ipv6_icmp_error_rfc4884(skb, &serr->ee.ee_rfc4884);
 336
 337	skb_reset_transport_header(skb);
 338
 339	if (sock_queue_err_skb(sk, skb))
 340		kfree_skb(skb);
 341}
 342EXPORT_SYMBOL_GPL(ipv6_icmp_error);
 343
 344void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 345{
 346	const struct ipv6_pinfo *np = inet6_sk(sk);
 347	struct sock_exterr_skb *serr;
 348	struct ipv6hdr *iph;
 349	struct sk_buff *skb;
 350
 351	if (!np->recverr)
 352		return;
 353
 354	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 355	if (!skb)
 356		return;
 357
 358	skb->protocol = htons(ETH_P_IPV6);
 359
 360	skb_put(skb, sizeof(struct ipv6hdr));
 361	skb_reset_network_header(skb);
 362	iph = ipv6_hdr(skb);
 363	iph->daddr = fl6->daddr;
 364	ip6_flow_hdr(iph, 0, 0);
 365
 366	serr = SKB_EXT_ERR(skb);
 367	serr->ee.ee_errno = err;
 368	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 369	serr->ee.ee_type = 0;
 370	serr->ee.ee_code = 0;
 371	serr->ee.ee_pad = 0;
 372	serr->ee.ee_info = info;
 373	serr->ee.ee_data = 0;
 374	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 375	serr->port = fl6->fl6_dport;
 376
 377	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 378	skb_reset_transport_header(skb);
 379
 380	if (sock_queue_err_skb(sk, skb))
 381		kfree_skb(skb);
 382}
 383
 384void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 385{
 386	struct ipv6_pinfo *np = inet6_sk(sk);
 387	struct ipv6hdr *iph;
 388	struct sk_buff *skb;
 389	struct ip6_mtuinfo *mtu_info;
 390
 391	if (!np->rxopt.bits.rxpmtu)
 392		return;
 393
 394	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 395	if (!skb)
 396		return;
 397
 398	skb_put(skb, sizeof(struct ipv6hdr));
 399	skb_reset_network_header(skb);
 400	iph = ipv6_hdr(skb);
 401	iph->daddr = fl6->daddr;
 402
 403	mtu_info = IP6CBMTU(skb);
 404
 405	mtu_info->ip6m_mtu = mtu;
 406	mtu_info->ip6m_addr.sin6_family = AF_INET6;
 407	mtu_info->ip6m_addr.sin6_port = 0;
 408	mtu_info->ip6m_addr.sin6_flowinfo = 0;
 409	mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 410	mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 411
 412	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 413	skb_reset_transport_header(skb);
 414
 415	skb = xchg(&np->rxpmtu, skb);
 416	kfree_skb(skb);
 417}
 418
 419/* For some errors we have valid addr_offset even with zero payload and
 420 * zero port. Also, addr_offset should be supported if port is set.
 421 */
 422static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 423{
 424	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 425	       serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 426	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 427}
 428
 429/* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 430 *
 431 * At one point, excluding local errors was a quick test to identify icmp/icmp6
 432 * errors. This is no longer true, but the test remained, so the v6 stack,
 433 * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 434 */
 435static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 436				      struct sock_exterr_skb *serr)
 437{
 438	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 439	    serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 440		return true;
 441
 442	if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 443		return false;
 444
 445	if (!IP6CB(skb)->iif)
 446		return false;
 447
 448	return true;
 449}
 450
 451/*
 452 *	Handle MSG_ERRQUEUE
 453 */
 454int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 455{
 456	struct ipv6_pinfo *np = inet6_sk(sk);
 457	struct sock_exterr_skb *serr;
 458	struct sk_buff *skb;
 459	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 460	struct {
 461		struct sock_extended_err ee;
 462		struct sockaddr_in6	 offender;
 463	} errhdr;
 464	int err;
 465	int copied;
 466
 467	err = -EAGAIN;
 468	skb = sock_dequeue_err_skb(sk);
 469	if (!skb)
 470		goto out;
 471
 472	copied = skb->len;
 473	if (copied > len) {
 474		msg->msg_flags |= MSG_TRUNC;
 475		copied = len;
 476	}
 477	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 478	if (unlikely(err)) {
 479		kfree_skb(skb);
 480		return err;
 481	}
 482	sock_recv_timestamp(msg, sk, skb);
 483
 484	serr = SKB_EXT_ERR(skb);
 485
 486	if (sin && ipv6_datagram_support_addr(serr)) {
 487		const unsigned char *nh = skb_network_header(skb);
 488		sin->sin6_family = AF_INET6;
 489		sin->sin6_flowinfo = 0;
 490		sin->sin6_port = serr->port;
 491		if (skb->protocol == htons(ETH_P_IPV6)) {
 492			const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 493								  struct ipv6hdr, daddr);
 494			sin->sin6_addr = ip6h->daddr;
 495			if (np->sndflow)
 496				sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 497			sin->sin6_scope_id =
 498				ipv6_iface_scope_id(&sin->sin6_addr,
 499						    IP6CB(skb)->iif);
 500		} else {
 501			ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 502					       &sin->sin6_addr);
 503			sin->sin6_scope_id = 0;
 504		}
 505		*addr_len = sizeof(*sin);
 506	}
 507
 508	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 509	sin = &errhdr.offender;
 510	memset(sin, 0, sizeof(*sin));
 511
 512	if (ip6_datagram_support_cmsg(skb, serr)) {
 513		sin->sin6_family = AF_INET6;
 514		if (np->rxopt.all)
 515			ip6_datagram_recv_common_ctl(sk, msg, skb);
 516		if (skb->protocol == htons(ETH_P_IPV6)) {
 517			sin->sin6_addr = ipv6_hdr(skb)->saddr;
 518			if (np->rxopt.all)
 519				ip6_datagram_recv_specific_ctl(sk, msg, skb);
 520			sin->sin6_scope_id =
 521				ipv6_iface_scope_id(&sin->sin6_addr,
 522						    IP6CB(skb)->iif);
 523		} else {
 524			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 525					       &sin->sin6_addr);
 526			if (inet_sk(sk)->cmsg_flags)
 527				ip_cmsg_recv(msg, skb);
 528		}
 529	}
 530
 531	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 532
 533	/* Now we could try to dump offended packet options */
 534
 535	msg->msg_flags |= MSG_ERRQUEUE;
 536	err = copied;
 537
 538	consume_skb(skb);
 539out:
 540	return err;
 541}
 542EXPORT_SYMBOL_GPL(ipv6_recv_error);
 543
 544/*
 545 *	Handle IPV6_RECVPATHMTU
 546 */
 547int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 548		     int *addr_len)
 549{
 550	struct ipv6_pinfo *np = inet6_sk(sk);
 551	struct sk_buff *skb;
 552	struct ip6_mtuinfo mtu_info;
 553	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 554	int err;
 555	int copied;
 556
 557	err = -EAGAIN;
 558	skb = xchg(&np->rxpmtu, NULL);
 559	if (!skb)
 560		goto out;
 561
 562	copied = skb->len;
 563	if (copied > len) {
 564		msg->msg_flags |= MSG_TRUNC;
 565		copied = len;
 566	}
 567	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 568	if (err)
 569		goto out_free_skb;
 570
 571	sock_recv_timestamp(msg, sk, skb);
 572
 573	memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 574
 575	if (sin) {
 576		sin->sin6_family = AF_INET6;
 577		sin->sin6_flowinfo = 0;
 578		sin->sin6_port = 0;
 579		sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 580		sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 581		*addr_len = sizeof(*sin);
 582	}
 583
 584	put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 585
 586	err = copied;
 587
 588out_free_skb:
 589	kfree_skb(skb);
 590out:
 591	return err;
 592}
 593
 594
 595void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 596				 struct sk_buff *skb)
 597{
 598	struct ipv6_pinfo *np = inet6_sk(sk);
 599	bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 600
 601	if (np->rxopt.bits.rxinfo) {
 602		struct in6_pktinfo src_info;
 603
 604		if (is_ipv6) {
 605			src_info.ipi6_ifindex = IP6CB(skb)->iif;
 606			src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 607		} else {
 608			src_info.ipi6_ifindex =
 609				PKTINFO_SKB_CB(skb)->ipi_ifindex;
 610			ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 611					       &src_info.ipi6_addr);
 612		}
 613
 614		if (src_info.ipi6_ifindex >= 0)
 615			put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 616				 sizeof(src_info), &src_info);
 617	}
 618}
 619
 620void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 621				    struct sk_buff *skb)
 622{
 623	struct ipv6_pinfo *np = inet6_sk(sk);
 624	struct inet6_skb_parm *opt = IP6CB(skb);
 625	unsigned char *nh = skb_network_header(skb);
 626
 627	if (np->rxopt.bits.rxhlim) {
 628		int hlim = ipv6_hdr(skb)->hop_limit;
 629		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 630	}
 631
 632	if (np->rxopt.bits.rxtclass) {
 633		int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 634		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 635	}
 636
 637	if (np->rxopt.bits.rxflow) {
 638		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 639		if (flowinfo)
 640			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 641	}
 642
 643	/* HbH is allowed only once */
 644	if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 645		u8 *ptr = nh + sizeof(struct ipv6hdr);
 646		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 647	}
 648
 649	if (opt->lastopt &&
 650	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 651		/*
 652		 * Silly enough, but we need to reparse in order to
 653		 * report extension headers (except for HbH)
 654		 * in order.
 655		 *
 656		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 657		 * (and WILL NOT be) defined because
 658		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 659		 */
 660		unsigned int off = sizeof(struct ipv6hdr);
 661		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 662
 663		while (off <= opt->lastopt) {
 664			unsigned int len;
 665			u8 *ptr = nh + off;
 666
 667			switch (nexthdr) {
 668			case IPPROTO_DSTOPTS:
 669				nexthdr = ptr[0];
 670				len = (ptr[1] + 1) << 3;
 671				if (np->rxopt.bits.dstopts)
 672					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 673				break;
 674			case IPPROTO_ROUTING:
 675				nexthdr = ptr[0];
 676				len = (ptr[1] + 1) << 3;
 677				if (np->rxopt.bits.srcrt)
 678					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 679				break;
 680			case IPPROTO_AH:
 681				nexthdr = ptr[0];
 682				len = (ptr[1] + 2) << 2;
 683				break;
 684			default:
 685				nexthdr = ptr[0];
 686				len = (ptr[1] + 1) << 3;
 687				break;
 688			}
 689
 690			off += len;
 691		}
 692	}
 693
 694	/* socket options in old style */
 695	if (np->rxopt.bits.rxoinfo) {
 696		struct in6_pktinfo src_info;
 697
 698		src_info.ipi6_ifindex = opt->iif;
 699		src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 700		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 701	}
 702	if (np->rxopt.bits.rxohlim) {
 703		int hlim = ipv6_hdr(skb)->hop_limit;
 704		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 705	}
 706	if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 707		u8 *ptr = nh + sizeof(struct ipv6hdr);
 708		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 709	}
 710	if (np->rxopt.bits.odstopts && opt->dst0) {
 711		u8 *ptr = nh + opt->dst0;
 712		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 713	}
 714	if (np->rxopt.bits.osrcrt && opt->srcrt) {
 715		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 716		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 717	}
 718	if (np->rxopt.bits.odstopts && opt->dst1) {
 719		u8 *ptr = nh + opt->dst1;
 720		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 721	}
 722	if (np->rxopt.bits.rxorigdstaddr) {
 723		struct sockaddr_in6 sin6;
 724		__be16 _ports[2], *ports;
 725
 726		ports = skb_header_pointer(skb, skb_transport_offset(skb),
 727					   sizeof(_ports), &_ports);
 728		if (ports) {
 729			/* All current transport protocols have the port numbers in the
 730			 * first four bytes of the transport header and this function is
 731			 * written with this assumption in mind.
 732			 */
 733			sin6.sin6_family = AF_INET6;
 734			sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 735			sin6.sin6_port = ports[1];
 736			sin6.sin6_flowinfo = 0;
 737			sin6.sin6_scope_id =
 738				ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 739						    opt->iif);
 740
 741			put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 742		}
 743	}
 744	if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 745		int val = opt->frag_max_size;
 746
 747		put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 748	}
 749}
 750
 751void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 752			  struct sk_buff *skb)
 753{
 754	ip6_datagram_recv_common_ctl(sk, msg, skb);
 755	ip6_datagram_recv_specific_ctl(sk, msg, skb);
 756}
 757EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 758
 759int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 760			  struct msghdr *msg, struct flowi6 *fl6,
 761			  struct ipcm6_cookie *ipc6)
 762{
 763	struct in6_pktinfo *src_info;
 764	struct cmsghdr *cmsg;
 765	struct ipv6_rt_hdr *rthdr;
 766	struct ipv6_opt_hdr *hdr;
 767	struct ipv6_txoptions *opt = ipc6->opt;
 768	int len;
 769	int err = 0;
 770
 771	for_each_cmsghdr(cmsg, msg) {
 772		int addr_type;
 773
 774		if (!CMSG_OK(msg, cmsg)) {
 775			err = -EINVAL;
 776			goto exit_f;
 777		}
 778
 779		if (cmsg->cmsg_level == SOL_SOCKET) {
 780			err = __sock_cmsg_send(sk, cmsg, &ipc6->sockc);
 781			if (err)
 782				return err;
 783			continue;
 784		}
 785
 786		if (cmsg->cmsg_level != SOL_IPV6)
 787			continue;
 788
 789		switch (cmsg->cmsg_type) {
 790		case IPV6_PKTINFO:
 791		case IPV6_2292PKTINFO:
 792		    {
 793			struct net_device *dev = NULL;
 794			int src_idx;
 795
 796			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 797				err = -EINVAL;
 798				goto exit_f;
 799			}
 800
 801			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 802			src_idx = src_info->ipi6_ifindex;
 803
 804			if (src_idx) {
 805				if (fl6->flowi6_oif &&
 806				    src_idx != fl6->flowi6_oif &&
 807				    (READ_ONCE(sk->sk_bound_dev_if) != fl6->flowi6_oif ||
 808				     !sk_dev_equal_l3scope(sk, src_idx)))
 809					return -EINVAL;
 810				fl6->flowi6_oif = src_idx;
 811			}
 812
 813			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 814
 815			rcu_read_lock();
 816			if (fl6->flowi6_oif) {
 817				dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 818				if (!dev) {
 819					rcu_read_unlock();
 820					return -ENODEV;
 821				}
 822			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 823				rcu_read_unlock();
 824				return -EINVAL;
 825			}
 826
 827			if (addr_type != IPV6_ADDR_ANY) {
 828				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 829				if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
 830				    !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 831							     dev, !strict, 0,
 832							     IFA_F_TENTATIVE) &&
 833				    !ipv6_chk_acast_addr_src(net, dev,
 834							     &src_info->ipi6_addr))
 835					err = -EINVAL;
 836				else
 837					fl6->saddr = src_info->ipi6_addr;
 838			}
 839
 840			rcu_read_unlock();
 841
 842			if (err)
 843				goto exit_f;
 844
 845			break;
 846		    }
 847
 848		case IPV6_FLOWINFO:
 849			if (cmsg->cmsg_len < CMSG_LEN(4)) {
 850				err = -EINVAL;
 851				goto exit_f;
 852			}
 853
 854			if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 855				if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 856					err = -EINVAL;
 857					goto exit_f;
 858				}
 859			}
 860			fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 861			break;
 862
 863		case IPV6_2292HOPOPTS:
 864		case IPV6_HOPOPTS:
 865			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 866				err = -EINVAL;
 867				goto exit_f;
 868			}
 869
 870			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 871			len = ((hdr->hdrlen + 1) << 3);
 872			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 873				err = -EINVAL;
 874				goto exit_f;
 875			}
 876			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 877				err = -EPERM;
 878				goto exit_f;
 879			}
 880			opt->opt_nflen += len;
 881			opt->hopopt = hdr;
 882			break;
 883
 884		case IPV6_2292DSTOPTS:
 885			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 886				err = -EINVAL;
 887				goto exit_f;
 888			}
 889
 890			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 891			len = ((hdr->hdrlen + 1) << 3);
 892			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 893				err = -EINVAL;
 894				goto exit_f;
 895			}
 896			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 897				err = -EPERM;
 898				goto exit_f;
 899			}
 900			if (opt->dst1opt) {
 901				err = -EINVAL;
 902				goto exit_f;
 903			}
 904			opt->opt_flen += len;
 905			opt->dst1opt = hdr;
 906			break;
 907
 908		case IPV6_DSTOPTS:
 909		case IPV6_RTHDRDSTOPTS:
 910			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 911				err = -EINVAL;
 912				goto exit_f;
 913			}
 914
 915			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 916			len = ((hdr->hdrlen + 1) << 3);
 917			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 918				err = -EINVAL;
 919				goto exit_f;
 920			}
 921			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 922				err = -EPERM;
 923				goto exit_f;
 924			}
 925			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 926				opt->opt_flen += len;
 927				opt->dst1opt = hdr;
 928			} else {
 929				opt->opt_nflen += len;
 930				opt->dst0opt = hdr;
 931			}
 932			break;
 933
 934		case IPV6_2292RTHDR:
 935		case IPV6_RTHDR:
 936			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 937				err = -EINVAL;
 938				goto exit_f;
 939			}
 940
 941			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 942
 943			switch (rthdr->type) {
 944#if IS_ENABLED(CONFIG_IPV6_MIP6)
 945			case IPV6_SRCRT_TYPE_2:
 946				if (rthdr->hdrlen != 2 ||
 947				    rthdr->segments_left != 1) {
 948					err = -EINVAL;
 949					goto exit_f;
 950				}
 951				break;
 952#endif
 953			default:
 954				err = -EINVAL;
 955				goto exit_f;
 956			}
 957
 958			len = ((rthdr->hdrlen + 1) << 3);
 959
 960			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 961				err = -EINVAL;
 962				goto exit_f;
 963			}
 964
 965			/* segments left must also match */
 966			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 967				err = -EINVAL;
 968				goto exit_f;
 969			}
 970
 971			opt->opt_nflen += len;
 972			opt->srcrt = rthdr;
 973
 974			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 975				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 976
 977				opt->opt_nflen += dsthdrlen;
 978				opt->dst0opt = opt->dst1opt;
 979				opt->dst1opt = NULL;
 980				opt->opt_flen -= dsthdrlen;
 981			}
 982
 983			break;
 984
 985		case IPV6_2292HOPLIMIT:
 986		case IPV6_HOPLIMIT:
 987			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 988				err = -EINVAL;
 989				goto exit_f;
 990			}
 991
 992			ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 993			if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 994				err = -EINVAL;
 995				goto exit_f;
 996			}
 997
 998			break;
 999
1000		case IPV6_TCLASS:
1001		    {
1002			int tc;
1003
1004			err = -EINVAL;
1005			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1006				goto exit_f;
1007
1008			tc = *(int *)CMSG_DATA(cmsg);
1009			if (tc < -1 || tc > 0xff)
1010				goto exit_f;
1011
1012			err = 0;
1013			ipc6->tclass = tc;
1014
1015			break;
1016		    }
1017
1018		case IPV6_DONTFRAG:
1019		    {
1020			int df;
1021
1022			err = -EINVAL;
1023			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1024				goto exit_f;
1025
1026			df = *(int *)CMSG_DATA(cmsg);
1027			if (df < 0 || df > 1)
1028				goto exit_f;
1029
1030			err = 0;
1031			ipc6->dontfrag = df;
1032
1033			break;
1034		    }
1035		default:
1036			net_dbg_ratelimited("invalid cmsg type: %d\n",
1037					    cmsg->cmsg_type);
1038			err = -EINVAL;
1039			goto exit_f;
1040		}
1041	}
1042
1043exit_f:
1044	return err;
1045}
1046EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1047
1048void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1049			       __u16 srcp, __u16 destp, int rqueue, int bucket)
1050{
1051	const struct in6_addr *dest, *src;
1052
1053	dest  = &sp->sk_v6_daddr;
1054	src   = &sp->sk_v6_rcv_saddr;
1055	seq_printf(seq,
1056		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1057		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
1058		   bucket,
1059		   src->s6_addr32[0], src->s6_addr32[1],
1060		   src->s6_addr32[2], src->s6_addr32[3], srcp,
1061		   dest->s6_addr32[0], dest->s6_addr32[1],
1062		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1063		   sp->sk_state,
1064		   sk_wmem_alloc_get(sp),
1065		   rqueue,
1066		   0, 0L, 0,
1067		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1068		   0,
1069		   sock_i_ino(sp),
1070		   refcount_read(&sp->sk_refcnt), sp,
1071		   atomic_read(&sp->sk_drops));
1072}