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v4.17
 
   1/*
   2 *	common UDP/RAW code
   3 *	Linux INET6 implementation
   4 *
   5 *	Authors:
   6 *	Pedro Roque		<roque@di.fc.ul.pt>
   7 *
   8 *	This program is free software; you can redistribute it and/or
   9 *      modify it under the terms of the GNU General Public License
  10 *      as published by the Free Software Foundation; either version
  11 *      2 of the License, or (at your option) any later version.
  12 */
  13
  14#include <linux/capability.h>
  15#include <linux/errno.h>
  16#include <linux/types.h>
  17#include <linux/kernel.h>
  18#include <linux/interrupt.h>
  19#include <linux/socket.h>
  20#include <linux/sockios.h>
  21#include <linux/in6.h>
  22#include <linux/ipv6.h>
  23#include <linux/route.h>
  24#include <linux/slab.h>
  25#include <linux/export.h>
  26
  27#include <net/ipv6.h>
  28#include <net/ndisc.h>
  29#include <net/addrconf.h>
  30#include <net/transp_v6.h>
  31#include <net/ip6_route.h>
  32#include <net/tcp_states.h>
  33#include <net/dsfield.h>
 
  34
  35#include <linux/errqueue.h>
  36#include <linux/uaccess.h>
  37
  38static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  39{
  40	return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  41}
  42
  43static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  44{
  45	struct inet_sock *inet = inet_sk(sk);
  46	struct ipv6_pinfo *np = inet6_sk(sk);
  47
  48	memset(fl6, 0, sizeof(*fl6));
  49	fl6->flowi6_proto = sk->sk_protocol;
  50	fl6->daddr = sk->sk_v6_daddr;
  51	fl6->saddr = np->saddr;
  52	fl6->flowi6_oif = sk->sk_bound_dev_if;
  53	fl6->flowi6_mark = sk->sk_mark;
  54	fl6->fl6_dport = inet->inet_dport;
  55	fl6->fl6_sport = inet->inet_sport;
  56	fl6->flowlabel = np->flow_label;
  57	fl6->flowi6_uid = sk->sk_uid;
  58
  59	if (!fl6->flowi6_oif)
  60		fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  61
  62	if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  63		fl6->flowi6_oif = np->mcast_oif;
  64
  65	security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  66}
  67
  68int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  69{
  70	struct ip6_flowlabel *flowlabel = NULL;
  71	struct in6_addr *final_p, final;
  72	struct ipv6_txoptions *opt;
  73	struct dst_entry *dst;
  74	struct inet_sock *inet = inet_sk(sk);
  75	struct ipv6_pinfo *np = inet6_sk(sk);
  76	struct flowi6 fl6;
  77	int err = 0;
  78
  79	if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  80		flowlabel = fl6_sock_lookup(sk, np->flow_label);
  81		if (!flowlabel)
  82			return -EINVAL;
  83	}
  84	ip6_datagram_flow_key_init(&fl6, sk);
  85
  86	rcu_read_lock();
  87	opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  88	final_p = fl6_update_dst(&fl6, opt, &final);
  89	rcu_read_unlock();
  90
  91	dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  92	if (IS_ERR(dst)) {
  93		err = PTR_ERR(dst);
  94		goto out;
  95	}
  96
  97	if (fix_sk_saddr) {
  98		if (ipv6_addr_any(&np->saddr))
  99			np->saddr = fl6.saddr;
 100
 101		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
 102			sk->sk_v6_rcv_saddr = fl6.saddr;
 103			inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 104			if (sk->sk_prot->rehash)
 105				sk->sk_prot->rehash(sk);
 106		}
 107	}
 108
 109	ip6_sk_dst_store_flow(sk, dst, &fl6);
 110
 111out:
 112	fl6_sock_release(flowlabel);
 113	return err;
 114}
 115
 116void ip6_datagram_release_cb(struct sock *sk)
 117{
 118	struct dst_entry *dst;
 119
 120	if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 121		return;
 122
 123	rcu_read_lock();
 124	dst = __sk_dst_get(sk);
 125	if (!dst || !dst->obsolete ||
 126	    dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 127		rcu_read_unlock();
 128		return;
 129	}
 130	rcu_read_unlock();
 131
 132	ip6_datagram_dst_update(sk, false);
 133}
 134EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 135
 136int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 137			   int addr_len)
 138{
 139	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
 140	struct inet_sock	*inet = inet_sk(sk);
 141	struct ipv6_pinfo	*np = inet6_sk(sk);
 142	struct in6_addr		*daddr, old_daddr;
 143	__be32			fl6_flowlabel = 0;
 144	__be32			old_fl6_flowlabel;
 145	__be16			old_dport;
 146	int			addr_type;
 147	int			err;
 148
 149	if (usin->sin6_family == AF_INET) {
 150		if (__ipv6_only_sock(sk))
 151			return -EAFNOSUPPORT;
 152		err = __ip4_datagram_connect(sk, uaddr, addr_len);
 153		goto ipv4_connected;
 154	}
 155
 156	if (addr_len < SIN6_LEN_RFC2133)
 157		return -EINVAL;
 158
 159	if (usin->sin6_family != AF_INET6)
 160		return -EAFNOSUPPORT;
 161
 162	if (np->sndflow)
 163		fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 164
 165	if (ipv6_addr_any(&usin->sin6_addr)) {
 166		/*
 167		 *	connect to self
 168		 */
 169		if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 170			ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 171					       &usin->sin6_addr);
 172		else
 173			usin->sin6_addr = in6addr_loopback;
 174	}
 175
 176	addr_type = ipv6_addr_type(&usin->sin6_addr);
 177
 178	daddr = &usin->sin6_addr;
 179
 180	if (addr_type & IPV6_ADDR_MAPPED) {
 181		struct sockaddr_in sin;
 182
 183		if (__ipv6_only_sock(sk)) {
 184			err = -ENETUNREACH;
 185			goto out;
 186		}
 187		sin.sin_family = AF_INET;
 188		sin.sin_addr.s_addr = daddr->s6_addr32[3];
 189		sin.sin_port = usin->sin6_port;
 190
 191		err = __ip4_datagram_connect(sk,
 192					     (struct sockaddr *) &sin,
 193					     sizeof(sin));
 194
 195ipv4_connected:
 196		if (err)
 197			goto out;
 198
 199		ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 200
 201		if (ipv6_addr_any(&np->saddr) ||
 202		    ipv6_mapped_addr_any(&np->saddr))
 203			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 204
 205		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 206		    ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 207			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 208					       &sk->sk_v6_rcv_saddr);
 209			if (sk->sk_prot->rehash)
 210				sk->sk_prot->rehash(sk);
 211		}
 212
 213		goto out;
 214	}
 215
 216	if (__ipv6_addr_needs_scope_id(addr_type)) {
 217		if (addr_len >= sizeof(struct sockaddr_in6) &&
 218		    usin->sin6_scope_id) {
 219			if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
 220				err = -EINVAL;
 221				goto out;
 222			}
 223			sk->sk_bound_dev_if = usin->sin6_scope_id;
 224		}
 225
 226		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 227			sk->sk_bound_dev_if = np->mcast_oif;
 228
 229		/* Connect to link-local address requires an interface */
 230		if (!sk->sk_bound_dev_if) {
 231			err = -EINVAL;
 232			goto out;
 233		}
 234	}
 235
 236	/* save the current peer information before updating it */
 237	old_daddr = sk->sk_v6_daddr;
 238	old_fl6_flowlabel = np->flow_label;
 239	old_dport = inet->inet_dport;
 240
 241	sk->sk_v6_daddr = *daddr;
 242	np->flow_label = fl6_flowlabel;
 243	inet->inet_dport = usin->sin6_port;
 244
 245	/*
 246	 *	Check for a route to destination an obtain the
 247	 *	destination cache for it.
 248	 */
 249
 250	err = ip6_datagram_dst_update(sk, true);
 251	if (err) {
 252		/* Restore the socket peer info, to keep it consistent with
 253		 * the old socket state
 254		 */
 255		sk->sk_v6_daddr = old_daddr;
 256		np->flow_label = old_fl6_flowlabel;
 257		inet->inet_dport = old_dport;
 258		goto out;
 259	}
 260
 
 261	sk->sk_state = TCP_ESTABLISHED;
 262	sk_set_txhash(sk);
 263out:
 264	return err;
 265}
 266EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 267
 268int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 269{
 270	int res;
 271
 272	lock_sock(sk);
 273	res = __ip6_datagram_connect(sk, uaddr, addr_len);
 274	release_sock(sk);
 275	return res;
 276}
 277EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 278
 279int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 280				 int addr_len)
 281{
 282	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 283	if (sin6->sin6_family != AF_INET6)
 284		return -EAFNOSUPPORT;
 285	return ip6_datagram_connect(sk, uaddr, addr_len);
 286}
 287EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 288
 289void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 290		     __be16 port, u32 info, u8 *payload)
 291{
 292	struct ipv6_pinfo *np  = inet6_sk(sk);
 293	struct icmp6hdr *icmph = icmp6_hdr(skb);
 294	struct sock_exterr_skb *serr;
 295
 296	if (!np->recverr)
 297		return;
 298
 299	skb = skb_clone(skb, GFP_ATOMIC);
 300	if (!skb)
 301		return;
 302
 303	skb->protocol = htons(ETH_P_IPV6);
 304
 305	serr = SKB_EXT_ERR(skb);
 306	serr->ee.ee_errno = err;
 307	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 308	serr->ee.ee_type = icmph->icmp6_type;
 309	serr->ee.ee_code = icmph->icmp6_code;
 310	serr->ee.ee_pad = 0;
 311	serr->ee.ee_info = info;
 312	serr->ee.ee_data = 0;
 313	serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 314				  skb_network_header(skb);
 315	serr->port = port;
 316
 317	__skb_pull(skb, payload - skb->data);
 318	skb_reset_transport_header(skb);
 319
 320	if (sock_queue_err_skb(sk, skb))
 321		kfree_skb(skb);
 322}
 323
 324void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 325{
 326	const struct ipv6_pinfo *np = inet6_sk(sk);
 327	struct sock_exterr_skb *serr;
 328	struct ipv6hdr *iph;
 329	struct sk_buff *skb;
 330
 331	if (!np->recverr)
 332		return;
 333
 334	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 335	if (!skb)
 336		return;
 337
 338	skb->protocol = htons(ETH_P_IPV6);
 339
 340	skb_put(skb, sizeof(struct ipv6hdr));
 341	skb_reset_network_header(skb);
 342	iph = ipv6_hdr(skb);
 343	iph->daddr = fl6->daddr;
 
 344
 345	serr = SKB_EXT_ERR(skb);
 346	serr->ee.ee_errno = err;
 347	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 348	serr->ee.ee_type = 0;
 349	serr->ee.ee_code = 0;
 350	serr->ee.ee_pad = 0;
 351	serr->ee.ee_info = info;
 352	serr->ee.ee_data = 0;
 353	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 354	serr->port = fl6->fl6_dport;
 355
 356	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 357	skb_reset_transport_header(skb);
 358
 359	if (sock_queue_err_skb(sk, skb))
 360		kfree_skb(skb);
 361}
 362
 363void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 364{
 365	struct ipv6_pinfo *np = inet6_sk(sk);
 366	struct ipv6hdr *iph;
 367	struct sk_buff *skb;
 368	struct ip6_mtuinfo *mtu_info;
 369
 370	if (!np->rxopt.bits.rxpmtu)
 371		return;
 372
 373	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 374	if (!skb)
 375		return;
 376
 377	skb_put(skb, sizeof(struct ipv6hdr));
 378	skb_reset_network_header(skb);
 379	iph = ipv6_hdr(skb);
 380	iph->daddr = fl6->daddr;
 381
 382	mtu_info = IP6CBMTU(skb);
 383
 384	mtu_info->ip6m_mtu = mtu;
 385	mtu_info->ip6m_addr.sin6_family = AF_INET6;
 386	mtu_info->ip6m_addr.sin6_port = 0;
 387	mtu_info->ip6m_addr.sin6_flowinfo = 0;
 388	mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 389	mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 390
 391	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 392	skb_reset_transport_header(skb);
 393
 394	skb = xchg(&np->rxpmtu, skb);
 395	kfree_skb(skb);
 396}
 397
 398/* For some errors we have valid addr_offset even with zero payload and
 399 * zero port. Also, addr_offset should be supported if port is set.
 400 */
 401static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 402{
 403	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 404	       serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 405	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 406}
 407
 408/* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 409 *
 410 * At one point, excluding local errors was a quick test to identify icmp/icmp6
 411 * errors. This is no longer true, but the test remained, so the v6 stack,
 412 * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 413 */
 414static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 415				      struct sock_exterr_skb *serr)
 416{
 417	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 418	    serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 419		return true;
 420
 421	if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 422		return false;
 423
 424	if (!IP6CB(skb)->iif)
 425		return false;
 426
 427	return true;
 428}
 429
 430/*
 431 *	Handle MSG_ERRQUEUE
 432 */
 433int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 434{
 435	struct ipv6_pinfo *np = inet6_sk(sk);
 436	struct sock_exterr_skb *serr;
 437	struct sk_buff *skb;
 438	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 439	struct {
 440		struct sock_extended_err ee;
 441		struct sockaddr_in6	 offender;
 442	} errhdr;
 443	int err;
 444	int copied;
 445
 446	err = -EAGAIN;
 447	skb = sock_dequeue_err_skb(sk);
 448	if (!skb)
 449		goto out;
 450
 451	copied = skb->len;
 452	if (copied > len) {
 453		msg->msg_flags |= MSG_TRUNC;
 454		copied = len;
 455	}
 456	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 457	if (unlikely(err)) {
 458		kfree_skb(skb);
 459		return err;
 460	}
 461	sock_recv_timestamp(msg, sk, skb);
 462
 463	serr = SKB_EXT_ERR(skb);
 464
 465	if (sin && ipv6_datagram_support_addr(serr)) {
 466		const unsigned char *nh = skb_network_header(skb);
 467		sin->sin6_family = AF_INET6;
 468		sin->sin6_flowinfo = 0;
 469		sin->sin6_port = serr->port;
 470		if (skb->protocol == htons(ETH_P_IPV6)) {
 471			const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 472								  struct ipv6hdr, daddr);
 473			sin->sin6_addr = ip6h->daddr;
 474			if (np->sndflow)
 475				sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 476			sin->sin6_scope_id =
 477				ipv6_iface_scope_id(&sin->sin6_addr,
 478						    IP6CB(skb)->iif);
 479		} else {
 480			ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 481					       &sin->sin6_addr);
 482			sin->sin6_scope_id = 0;
 483		}
 484		*addr_len = sizeof(*sin);
 485	}
 486
 487	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 488	sin = &errhdr.offender;
 489	memset(sin, 0, sizeof(*sin));
 490
 491	if (ip6_datagram_support_cmsg(skb, serr)) {
 492		sin->sin6_family = AF_INET6;
 493		if (np->rxopt.all)
 494			ip6_datagram_recv_common_ctl(sk, msg, skb);
 495		if (skb->protocol == htons(ETH_P_IPV6)) {
 496			sin->sin6_addr = ipv6_hdr(skb)->saddr;
 497			if (np->rxopt.all)
 498				ip6_datagram_recv_specific_ctl(sk, msg, skb);
 499			sin->sin6_scope_id =
 500				ipv6_iface_scope_id(&sin->sin6_addr,
 501						    IP6CB(skb)->iif);
 502		} else {
 503			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 504					       &sin->sin6_addr);
 505			if (inet_sk(sk)->cmsg_flags)
 506				ip_cmsg_recv(msg, skb);
 507		}
 508	}
 509
 510	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 511
 512	/* Now we could try to dump offended packet options */
 513
 514	msg->msg_flags |= MSG_ERRQUEUE;
 515	err = copied;
 516
 517	consume_skb(skb);
 518out:
 519	return err;
 520}
 521EXPORT_SYMBOL_GPL(ipv6_recv_error);
 522
 523/*
 524 *	Handle IPV6_RECVPATHMTU
 525 */
 526int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 527		     int *addr_len)
 528{
 529	struct ipv6_pinfo *np = inet6_sk(sk);
 530	struct sk_buff *skb;
 531	struct ip6_mtuinfo mtu_info;
 532	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 533	int err;
 534	int copied;
 535
 536	err = -EAGAIN;
 537	skb = xchg(&np->rxpmtu, NULL);
 538	if (!skb)
 539		goto out;
 540
 541	copied = skb->len;
 542	if (copied > len) {
 543		msg->msg_flags |= MSG_TRUNC;
 544		copied = len;
 545	}
 546	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 547	if (err)
 548		goto out_free_skb;
 549
 550	sock_recv_timestamp(msg, sk, skb);
 551
 552	memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 553
 554	if (sin) {
 555		sin->sin6_family = AF_INET6;
 556		sin->sin6_flowinfo = 0;
 557		sin->sin6_port = 0;
 558		sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 559		sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 560		*addr_len = sizeof(*sin);
 561	}
 562
 563	put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 564
 565	err = copied;
 566
 567out_free_skb:
 568	kfree_skb(skb);
 569out:
 570	return err;
 571}
 572
 573
 574void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 575				 struct sk_buff *skb)
 576{
 577	struct ipv6_pinfo *np = inet6_sk(sk);
 578	bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 579
 580	if (np->rxopt.bits.rxinfo) {
 581		struct in6_pktinfo src_info;
 582
 583		if (is_ipv6) {
 584			src_info.ipi6_ifindex = IP6CB(skb)->iif;
 585			src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 586		} else {
 587			src_info.ipi6_ifindex =
 588				PKTINFO_SKB_CB(skb)->ipi_ifindex;
 589			ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 590					       &src_info.ipi6_addr);
 591		}
 592
 593		if (src_info.ipi6_ifindex >= 0)
 594			put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 595				 sizeof(src_info), &src_info);
 596	}
 597}
 598
 599void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 600				    struct sk_buff *skb)
 601{
 602	struct ipv6_pinfo *np = inet6_sk(sk);
 603	struct inet6_skb_parm *opt = IP6CB(skb);
 604	unsigned char *nh = skb_network_header(skb);
 605
 606	if (np->rxopt.bits.rxhlim) {
 607		int hlim = ipv6_hdr(skb)->hop_limit;
 608		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 609	}
 610
 611	if (np->rxopt.bits.rxtclass) {
 612		int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 613		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 614	}
 615
 616	if (np->rxopt.bits.rxflow) {
 617		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 618		if (flowinfo)
 619			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 620	}
 621
 622	/* HbH is allowed only once */
 623	if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 624		u8 *ptr = nh + sizeof(struct ipv6hdr);
 625		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 626	}
 627
 628	if (opt->lastopt &&
 629	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 630		/*
 631		 * Silly enough, but we need to reparse in order to
 632		 * report extension headers (except for HbH)
 633		 * in order.
 634		 *
 635		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 636		 * (and WILL NOT be) defined because
 637		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 638		 */
 639		unsigned int off = sizeof(struct ipv6hdr);
 640		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 641
 642		while (off <= opt->lastopt) {
 643			unsigned int len;
 644			u8 *ptr = nh + off;
 645
 646			switch (nexthdr) {
 647			case IPPROTO_DSTOPTS:
 648				nexthdr = ptr[0];
 649				len = (ptr[1] + 1) << 3;
 650				if (np->rxopt.bits.dstopts)
 651					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 652				break;
 653			case IPPROTO_ROUTING:
 654				nexthdr = ptr[0];
 655				len = (ptr[1] + 1) << 3;
 656				if (np->rxopt.bits.srcrt)
 657					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 658				break;
 659			case IPPROTO_AH:
 660				nexthdr = ptr[0];
 661				len = (ptr[1] + 2) << 2;
 662				break;
 663			default:
 664				nexthdr = ptr[0];
 665				len = (ptr[1] + 1) << 3;
 666				break;
 667			}
 668
 669			off += len;
 670		}
 671	}
 672
 673	/* socket options in old style */
 674	if (np->rxopt.bits.rxoinfo) {
 675		struct in6_pktinfo src_info;
 676
 677		src_info.ipi6_ifindex = opt->iif;
 678		src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 679		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 680	}
 681	if (np->rxopt.bits.rxohlim) {
 682		int hlim = ipv6_hdr(skb)->hop_limit;
 683		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 684	}
 685	if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 686		u8 *ptr = nh + sizeof(struct ipv6hdr);
 687		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 688	}
 689	if (np->rxopt.bits.odstopts && opt->dst0) {
 690		u8 *ptr = nh + opt->dst0;
 691		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 692	}
 693	if (np->rxopt.bits.osrcrt && opt->srcrt) {
 694		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 695		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 696	}
 697	if (np->rxopt.bits.odstopts && opt->dst1) {
 698		u8 *ptr = nh + opt->dst1;
 699		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 700	}
 701	if (np->rxopt.bits.rxorigdstaddr) {
 702		struct sockaddr_in6 sin6;
 703		__be16 *ports = (__be16 *) skb_transport_header(skb);
 704
 705		if (skb_transport_offset(skb) + 4 <= (int)skb->len) {
 
 
 706			/* All current transport protocols have the port numbers in the
 707			 * first four bytes of the transport header and this function is
 708			 * written with this assumption in mind.
 709			 */
 710
 711			sin6.sin6_family = AF_INET6;
 712			sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 713			sin6.sin6_port = ports[1];
 714			sin6.sin6_flowinfo = 0;
 715			sin6.sin6_scope_id =
 716				ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 717						    opt->iif);
 718
 719			put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 720		}
 721	}
 722	if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 723		int val = opt->frag_max_size;
 724
 725		put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 726	}
 727}
 728
 729void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 730			  struct sk_buff *skb)
 731{
 732	ip6_datagram_recv_common_ctl(sk, msg, skb);
 733	ip6_datagram_recv_specific_ctl(sk, msg, skb);
 734}
 735EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 736
 737int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 738			  struct msghdr *msg, struct flowi6 *fl6,
 739			  struct ipcm6_cookie *ipc6, struct sockcm_cookie *sockc)
 740{
 741	struct in6_pktinfo *src_info;
 742	struct cmsghdr *cmsg;
 743	struct ipv6_rt_hdr *rthdr;
 744	struct ipv6_opt_hdr *hdr;
 745	struct ipv6_txoptions *opt = ipc6->opt;
 746	int len;
 747	int err = 0;
 748
 749	for_each_cmsghdr(cmsg, msg) {
 750		int addr_type;
 751
 752		if (!CMSG_OK(msg, cmsg)) {
 753			err = -EINVAL;
 754			goto exit_f;
 755		}
 756
 757		if (cmsg->cmsg_level == SOL_SOCKET) {
 758			err = __sock_cmsg_send(sk, msg, cmsg, sockc);
 759			if (err)
 760				return err;
 761			continue;
 762		}
 763
 764		if (cmsg->cmsg_level != SOL_IPV6)
 765			continue;
 766
 767		switch (cmsg->cmsg_type) {
 768		case IPV6_PKTINFO:
 769		case IPV6_2292PKTINFO:
 770		    {
 771			struct net_device *dev = NULL;
 
 772
 773			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 774				err = -EINVAL;
 775				goto exit_f;
 776			}
 777
 778			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 
 779
 780			if (src_info->ipi6_ifindex) {
 781				if (fl6->flowi6_oif &&
 782				    src_info->ipi6_ifindex != fl6->flowi6_oif)
 
 
 783					return -EINVAL;
 784				fl6->flowi6_oif = src_info->ipi6_ifindex;
 785			}
 786
 787			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 788
 789			rcu_read_lock();
 790			if (fl6->flowi6_oif) {
 791				dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 792				if (!dev) {
 793					rcu_read_unlock();
 794					return -ENODEV;
 795				}
 796			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 797				rcu_read_unlock();
 798				return -EINVAL;
 799			}
 800
 801			if (addr_type != IPV6_ADDR_ANY) {
 802				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 803				if (!(inet_sk(sk)->freebind || inet_sk(sk)->transparent) &&
 804				    !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 805							     dev, !strict, 0,
 806							     IFA_F_TENTATIVE) &&
 807				    !ipv6_chk_acast_addr_src(net, dev,
 808							     &src_info->ipi6_addr))
 809					err = -EINVAL;
 810				else
 811					fl6->saddr = src_info->ipi6_addr;
 812			}
 813
 814			rcu_read_unlock();
 815
 816			if (err)
 817				goto exit_f;
 818
 819			break;
 820		    }
 821
 822		case IPV6_FLOWINFO:
 823			if (cmsg->cmsg_len < CMSG_LEN(4)) {
 824				err = -EINVAL;
 825				goto exit_f;
 826			}
 827
 828			if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 829				if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 830					err = -EINVAL;
 831					goto exit_f;
 832				}
 833			}
 834			fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 835			break;
 836
 837		case IPV6_2292HOPOPTS:
 838		case IPV6_HOPOPTS:
 839			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 840				err = -EINVAL;
 841				goto exit_f;
 842			}
 843
 844			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 845			len = ((hdr->hdrlen + 1) << 3);
 846			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 847				err = -EINVAL;
 848				goto exit_f;
 849			}
 850			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 851				err = -EPERM;
 852				goto exit_f;
 853			}
 854			opt->opt_nflen += len;
 855			opt->hopopt = hdr;
 856			break;
 857
 858		case IPV6_2292DSTOPTS:
 859			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 860				err = -EINVAL;
 861				goto exit_f;
 862			}
 863
 864			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 865			len = ((hdr->hdrlen + 1) << 3);
 866			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 867				err = -EINVAL;
 868				goto exit_f;
 869			}
 870			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 871				err = -EPERM;
 872				goto exit_f;
 873			}
 874			if (opt->dst1opt) {
 875				err = -EINVAL;
 876				goto exit_f;
 877			}
 878			opt->opt_flen += len;
 879			opt->dst1opt = hdr;
 880			break;
 881
 882		case IPV6_DSTOPTS:
 883		case IPV6_RTHDRDSTOPTS:
 884			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 885				err = -EINVAL;
 886				goto exit_f;
 887			}
 888
 889			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 890			len = ((hdr->hdrlen + 1) << 3);
 891			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 892				err = -EINVAL;
 893				goto exit_f;
 894			}
 895			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 896				err = -EPERM;
 897				goto exit_f;
 898			}
 899			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 900				opt->opt_flen += len;
 901				opt->dst1opt = hdr;
 902			} else {
 903				opt->opt_nflen += len;
 904				opt->dst0opt = hdr;
 905			}
 906			break;
 907
 908		case IPV6_2292RTHDR:
 909		case IPV6_RTHDR:
 910			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 911				err = -EINVAL;
 912				goto exit_f;
 913			}
 914
 915			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 916
 917			switch (rthdr->type) {
 918#if IS_ENABLED(CONFIG_IPV6_MIP6)
 919			case IPV6_SRCRT_TYPE_2:
 920				if (rthdr->hdrlen != 2 ||
 921				    rthdr->segments_left != 1) {
 922					err = -EINVAL;
 923					goto exit_f;
 924				}
 925				break;
 926#endif
 927			default:
 928				err = -EINVAL;
 929				goto exit_f;
 930			}
 931
 932			len = ((rthdr->hdrlen + 1) << 3);
 933
 934			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 935				err = -EINVAL;
 936				goto exit_f;
 937			}
 938
 939			/* segments left must also match */
 940			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 941				err = -EINVAL;
 942				goto exit_f;
 943			}
 944
 945			opt->opt_nflen += len;
 946			opt->srcrt = rthdr;
 947
 948			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 949				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 950
 951				opt->opt_nflen += dsthdrlen;
 952				opt->dst0opt = opt->dst1opt;
 953				opt->dst1opt = NULL;
 954				opt->opt_flen -= dsthdrlen;
 955			}
 956
 957			break;
 958
 959		case IPV6_2292HOPLIMIT:
 960		case IPV6_HOPLIMIT:
 961			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 962				err = -EINVAL;
 963				goto exit_f;
 964			}
 965
 966			ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 967			if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 968				err = -EINVAL;
 969				goto exit_f;
 970			}
 971
 972			break;
 973
 974		case IPV6_TCLASS:
 975		    {
 976			int tc;
 977
 978			err = -EINVAL;
 979			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 980				goto exit_f;
 981
 982			tc = *(int *)CMSG_DATA(cmsg);
 983			if (tc < -1 || tc > 0xff)
 984				goto exit_f;
 985
 986			err = 0;
 987			ipc6->tclass = tc;
 988
 989			break;
 990		    }
 991
 992		case IPV6_DONTFRAG:
 993		    {
 994			int df;
 995
 996			err = -EINVAL;
 997			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 998				goto exit_f;
 999
1000			df = *(int *)CMSG_DATA(cmsg);
1001			if (df < 0 || df > 1)
1002				goto exit_f;
1003
1004			err = 0;
1005			ipc6->dontfrag = df;
1006
1007			break;
1008		    }
1009		default:
1010			net_dbg_ratelimited("invalid cmsg type: %d\n",
1011					    cmsg->cmsg_type);
1012			err = -EINVAL;
1013			goto exit_f;
1014		}
1015	}
1016
1017exit_f:
1018	return err;
1019}
1020EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1021
1022void ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1023			     __u16 srcp, __u16 destp, int bucket)
1024{
1025	const struct in6_addr *dest, *src;
1026
1027	dest  = &sp->sk_v6_daddr;
1028	src   = &sp->sk_v6_rcv_saddr;
1029	seq_printf(seq,
1030		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1031		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %d\n",
1032		   bucket,
1033		   src->s6_addr32[0], src->s6_addr32[1],
1034		   src->s6_addr32[2], src->s6_addr32[3], srcp,
1035		   dest->s6_addr32[0], dest->s6_addr32[1],
1036		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1037		   sp->sk_state,
1038		   sk_wmem_alloc_get(sp),
1039		   sk_rmem_alloc_get(sp),
1040		   0, 0L, 0,
1041		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1042		   0,
1043		   sock_i_ino(sp),
1044		   refcount_read(&sp->sk_refcnt), sp,
1045		   atomic_read(&sp->sk_drops));
1046}
v5.4
   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
  23#include <net/ipv6.h>
  24#include <net/ndisc.h>
  25#include <net/addrconf.h>
  26#include <net/transp_v6.h>
  27#include <net/ip6_route.h>
  28#include <net/tcp_states.h>
  29#include <net/dsfield.h>
  30#include <net/sock_reuseport.h>
  31
  32#include <linux/errqueue.h>
  33#include <linux/uaccess.h>
  34
  35static bool ipv6_mapped_addr_any(const struct in6_addr *a)
  36{
  37	return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
  38}
  39
  40static void ip6_datagram_flow_key_init(struct flowi6 *fl6, struct sock *sk)
  41{
  42	struct inet_sock *inet = inet_sk(sk);
  43	struct ipv6_pinfo *np = inet6_sk(sk);
  44
  45	memset(fl6, 0, sizeof(*fl6));
  46	fl6->flowi6_proto = sk->sk_protocol;
  47	fl6->daddr = sk->sk_v6_daddr;
  48	fl6->saddr = np->saddr;
  49	fl6->flowi6_oif = sk->sk_bound_dev_if;
  50	fl6->flowi6_mark = sk->sk_mark;
  51	fl6->fl6_dport = inet->inet_dport;
  52	fl6->fl6_sport = inet->inet_sport;
  53	fl6->flowlabel = np->flow_label;
  54	fl6->flowi6_uid = sk->sk_uid;
  55
  56	if (!fl6->flowi6_oif)
  57		fl6->flowi6_oif = np->sticky_pktinfo.ipi6_ifindex;
  58
  59	if (!fl6->flowi6_oif && ipv6_addr_is_multicast(&fl6->daddr))
  60		fl6->flowi6_oif = np->mcast_oif;
  61
  62	security_sk_classify_flow(sk, flowi6_to_flowi(fl6));
  63}
  64
  65int ip6_datagram_dst_update(struct sock *sk, bool fix_sk_saddr)
  66{
  67	struct ip6_flowlabel *flowlabel = NULL;
  68	struct in6_addr *final_p, final;
  69	struct ipv6_txoptions *opt;
  70	struct dst_entry *dst;
  71	struct inet_sock *inet = inet_sk(sk);
  72	struct ipv6_pinfo *np = inet6_sk(sk);
  73	struct flowi6 fl6;
  74	int err = 0;
  75
  76	if (np->sndflow && (np->flow_label & IPV6_FLOWLABEL_MASK)) {
  77		flowlabel = fl6_sock_lookup(sk, np->flow_label);
  78		if (IS_ERR(flowlabel))
  79			return -EINVAL;
  80	}
  81	ip6_datagram_flow_key_init(&fl6, sk);
  82
  83	rcu_read_lock();
  84	opt = flowlabel ? flowlabel->opt : rcu_dereference(np->opt);
  85	final_p = fl6_update_dst(&fl6, opt, &final);
  86	rcu_read_unlock();
  87
  88	dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
  89	if (IS_ERR(dst)) {
  90		err = PTR_ERR(dst);
  91		goto out;
  92	}
  93
  94	if (fix_sk_saddr) {
  95		if (ipv6_addr_any(&np->saddr))
  96			np->saddr = fl6.saddr;
  97
  98		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) {
  99			sk->sk_v6_rcv_saddr = fl6.saddr;
 100			inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 101			if (sk->sk_prot->rehash)
 102				sk->sk_prot->rehash(sk);
 103		}
 104	}
 105
 106	ip6_sk_dst_store_flow(sk, dst, &fl6);
 107
 108out:
 109	fl6_sock_release(flowlabel);
 110	return err;
 111}
 112
 113void ip6_datagram_release_cb(struct sock *sk)
 114{
 115	struct dst_entry *dst;
 116
 117	if (ipv6_addr_v4mapped(&sk->sk_v6_daddr))
 118		return;
 119
 120	rcu_read_lock();
 121	dst = __sk_dst_get(sk);
 122	if (!dst || !dst->obsolete ||
 123	    dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) {
 124		rcu_read_unlock();
 125		return;
 126	}
 127	rcu_read_unlock();
 128
 129	ip6_datagram_dst_update(sk, false);
 130}
 131EXPORT_SYMBOL_GPL(ip6_datagram_release_cb);
 132
 133int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr,
 134			   int addr_len)
 135{
 136	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
 137	struct inet_sock	*inet = inet_sk(sk);
 138	struct ipv6_pinfo	*np = inet6_sk(sk);
 139	struct in6_addr		*daddr, old_daddr;
 140	__be32			fl6_flowlabel = 0;
 141	__be32			old_fl6_flowlabel;
 142	__be16			old_dport;
 143	int			addr_type;
 144	int			err;
 145
 146	if (usin->sin6_family == AF_INET) {
 147		if (__ipv6_only_sock(sk))
 148			return -EAFNOSUPPORT;
 149		err = __ip4_datagram_connect(sk, uaddr, addr_len);
 150		goto ipv4_connected;
 151	}
 152
 153	if (addr_len < SIN6_LEN_RFC2133)
 154		return -EINVAL;
 155
 156	if (usin->sin6_family != AF_INET6)
 157		return -EAFNOSUPPORT;
 158
 159	if (np->sndflow)
 160		fl6_flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;
 161
 162	if (ipv6_addr_any(&usin->sin6_addr)) {
 163		/*
 164		 *	connect to self
 165		 */
 166		if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 167			ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 168					       &usin->sin6_addr);
 169		else
 170			usin->sin6_addr = in6addr_loopback;
 171	}
 172
 173	addr_type = ipv6_addr_type(&usin->sin6_addr);
 174
 175	daddr = &usin->sin6_addr;
 176
 177	if (addr_type & IPV6_ADDR_MAPPED) {
 178		struct sockaddr_in sin;
 179
 180		if (__ipv6_only_sock(sk)) {
 181			err = -ENETUNREACH;
 182			goto out;
 183		}
 184		sin.sin_family = AF_INET;
 185		sin.sin_addr.s_addr = daddr->s6_addr32[3];
 186		sin.sin_port = usin->sin6_port;
 187
 188		err = __ip4_datagram_connect(sk,
 189					     (struct sockaddr *) &sin,
 190					     sizeof(sin));
 191
 192ipv4_connected:
 193		if (err)
 194			goto out;
 195
 196		ipv6_addr_set_v4mapped(inet->inet_daddr, &sk->sk_v6_daddr);
 197
 198		if (ipv6_addr_any(&np->saddr) ||
 199		    ipv6_mapped_addr_any(&np->saddr))
 200			ipv6_addr_set_v4mapped(inet->inet_saddr, &np->saddr);
 201
 202		if (ipv6_addr_any(&sk->sk_v6_rcv_saddr) ||
 203		    ipv6_mapped_addr_any(&sk->sk_v6_rcv_saddr)) {
 204			ipv6_addr_set_v4mapped(inet->inet_rcv_saddr,
 205					       &sk->sk_v6_rcv_saddr);
 206			if (sk->sk_prot->rehash)
 207				sk->sk_prot->rehash(sk);
 208		}
 209
 210		goto out;
 211	}
 212
 213	if (__ipv6_addr_needs_scope_id(addr_type)) {
 214		if (addr_len >= sizeof(struct sockaddr_in6) &&
 215		    usin->sin6_scope_id) {
 216			if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) {
 217				err = -EINVAL;
 218				goto out;
 219			}
 220			sk->sk_bound_dev_if = usin->sin6_scope_id;
 221		}
 222
 223		if (!sk->sk_bound_dev_if && (addr_type & IPV6_ADDR_MULTICAST))
 224			sk->sk_bound_dev_if = np->mcast_oif;
 225
 226		/* Connect to link-local address requires an interface */
 227		if (!sk->sk_bound_dev_if) {
 228			err = -EINVAL;
 229			goto out;
 230		}
 231	}
 232
 233	/* save the current peer information before updating it */
 234	old_daddr = sk->sk_v6_daddr;
 235	old_fl6_flowlabel = np->flow_label;
 236	old_dport = inet->inet_dport;
 237
 238	sk->sk_v6_daddr = *daddr;
 239	np->flow_label = fl6_flowlabel;
 240	inet->inet_dport = usin->sin6_port;
 241
 242	/*
 243	 *	Check for a route to destination an obtain the
 244	 *	destination cache for it.
 245	 */
 246
 247	err = ip6_datagram_dst_update(sk, true);
 248	if (err) {
 249		/* Restore the socket peer info, to keep it consistent with
 250		 * the old socket state
 251		 */
 252		sk->sk_v6_daddr = old_daddr;
 253		np->flow_label = old_fl6_flowlabel;
 254		inet->inet_dport = old_dport;
 255		goto out;
 256	}
 257
 258	reuseport_has_conns(sk, true);
 259	sk->sk_state = TCP_ESTABLISHED;
 260	sk_set_txhash(sk);
 261out:
 262	return err;
 263}
 264EXPORT_SYMBOL_GPL(__ip6_datagram_connect);
 265
 266int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 267{
 268	int res;
 269
 270	lock_sock(sk);
 271	res = __ip6_datagram_connect(sk, uaddr, addr_len);
 272	release_sock(sk);
 273	return res;
 274}
 275EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 276
 277int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,
 278				 int addr_len)
 279{
 280	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, uaddr);
 281	if (sin6->sin6_family != AF_INET6)
 282		return -EAFNOSUPPORT;
 283	return ip6_datagram_connect(sk, uaddr, addr_len);
 284}
 285EXPORT_SYMBOL_GPL(ip6_datagram_connect_v6_only);
 286
 287void ipv6_icmp_error(struct sock *sk, struct sk_buff *skb, int err,
 288		     __be16 port, u32 info, u8 *payload)
 289{
 290	struct ipv6_pinfo *np  = inet6_sk(sk);
 291	struct icmp6hdr *icmph = icmp6_hdr(skb);
 292	struct sock_exterr_skb *serr;
 293
 294	if (!np->recverr)
 295		return;
 296
 297	skb = skb_clone(skb, GFP_ATOMIC);
 298	if (!skb)
 299		return;
 300
 301	skb->protocol = htons(ETH_P_IPV6);
 302
 303	serr = SKB_EXT_ERR(skb);
 304	serr->ee.ee_errno = err;
 305	serr->ee.ee_origin = SO_EE_ORIGIN_ICMP6;
 306	serr->ee.ee_type = icmph->icmp6_type;
 307	serr->ee.ee_code = icmph->icmp6_code;
 308	serr->ee.ee_pad = 0;
 309	serr->ee.ee_info = info;
 310	serr->ee.ee_data = 0;
 311	serr->addr_offset = (u8 *)&(((struct ipv6hdr *)(icmph + 1))->daddr) -
 312				  skb_network_header(skb);
 313	serr->port = port;
 314
 315	__skb_pull(skb, payload - skb->data);
 316	skb_reset_transport_header(skb);
 317
 318	if (sock_queue_err_skb(sk, skb))
 319		kfree_skb(skb);
 320}
 321
 322void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info)
 323{
 324	const struct ipv6_pinfo *np = inet6_sk(sk);
 325	struct sock_exterr_skb *serr;
 326	struct ipv6hdr *iph;
 327	struct sk_buff *skb;
 328
 329	if (!np->recverr)
 330		return;
 331
 332	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 333	if (!skb)
 334		return;
 335
 336	skb->protocol = htons(ETH_P_IPV6);
 337
 338	skb_put(skb, sizeof(struct ipv6hdr));
 339	skb_reset_network_header(skb);
 340	iph = ipv6_hdr(skb);
 341	iph->daddr = fl6->daddr;
 342	ip6_flow_hdr(iph, 0, 0);
 343
 344	serr = SKB_EXT_ERR(skb);
 345	serr->ee.ee_errno = err;
 346	serr->ee.ee_origin = SO_EE_ORIGIN_LOCAL;
 347	serr->ee.ee_type = 0;
 348	serr->ee.ee_code = 0;
 349	serr->ee.ee_pad = 0;
 350	serr->ee.ee_info = info;
 351	serr->ee.ee_data = 0;
 352	serr->addr_offset = (u8 *)&iph->daddr - skb_network_header(skb);
 353	serr->port = fl6->fl6_dport;
 354
 355	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 356	skb_reset_transport_header(skb);
 357
 358	if (sock_queue_err_skb(sk, skb))
 359		kfree_skb(skb);
 360}
 361
 362void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu)
 363{
 364	struct ipv6_pinfo *np = inet6_sk(sk);
 365	struct ipv6hdr *iph;
 366	struct sk_buff *skb;
 367	struct ip6_mtuinfo *mtu_info;
 368
 369	if (!np->rxopt.bits.rxpmtu)
 370		return;
 371
 372	skb = alloc_skb(sizeof(struct ipv6hdr), GFP_ATOMIC);
 373	if (!skb)
 374		return;
 375
 376	skb_put(skb, sizeof(struct ipv6hdr));
 377	skb_reset_network_header(skb);
 378	iph = ipv6_hdr(skb);
 379	iph->daddr = fl6->daddr;
 380
 381	mtu_info = IP6CBMTU(skb);
 382
 383	mtu_info->ip6m_mtu = mtu;
 384	mtu_info->ip6m_addr.sin6_family = AF_INET6;
 385	mtu_info->ip6m_addr.sin6_port = 0;
 386	mtu_info->ip6m_addr.sin6_flowinfo = 0;
 387	mtu_info->ip6m_addr.sin6_scope_id = fl6->flowi6_oif;
 388	mtu_info->ip6m_addr.sin6_addr = ipv6_hdr(skb)->daddr;
 389
 390	__skb_pull(skb, skb_tail_pointer(skb) - skb->data);
 391	skb_reset_transport_header(skb);
 392
 393	skb = xchg(&np->rxpmtu, skb);
 394	kfree_skb(skb);
 395}
 396
 397/* For some errors we have valid addr_offset even with zero payload and
 398 * zero port. Also, addr_offset should be supported if port is set.
 399 */
 400static inline bool ipv6_datagram_support_addr(struct sock_exterr_skb *serr)
 401{
 402	return serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6 ||
 403	       serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 404	       serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL || serr->port;
 405}
 406
 407/* IPv6 supports cmsg on all origins aside from SO_EE_ORIGIN_LOCAL.
 408 *
 409 * At one point, excluding local errors was a quick test to identify icmp/icmp6
 410 * errors. This is no longer true, but the test remained, so the v6 stack,
 411 * unlike v4, also honors cmsg requests on all wifi and timestamp errors.
 412 */
 413static bool ip6_datagram_support_cmsg(struct sk_buff *skb,
 414				      struct sock_exterr_skb *serr)
 415{
 416	if (serr->ee.ee_origin == SO_EE_ORIGIN_ICMP ||
 417	    serr->ee.ee_origin == SO_EE_ORIGIN_ICMP6)
 418		return true;
 419
 420	if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL)
 421		return false;
 422
 423	if (!IP6CB(skb)->iif)
 424		return false;
 425
 426	return true;
 427}
 428
 429/*
 430 *	Handle MSG_ERRQUEUE
 431 */
 432int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 433{
 434	struct ipv6_pinfo *np = inet6_sk(sk);
 435	struct sock_exterr_skb *serr;
 436	struct sk_buff *skb;
 437	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 438	struct {
 439		struct sock_extended_err ee;
 440		struct sockaddr_in6	 offender;
 441	} errhdr;
 442	int err;
 443	int copied;
 444
 445	err = -EAGAIN;
 446	skb = sock_dequeue_err_skb(sk);
 447	if (!skb)
 448		goto out;
 449
 450	copied = skb->len;
 451	if (copied > len) {
 452		msg->msg_flags |= MSG_TRUNC;
 453		copied = len;
 454	}
 455	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 456	if (unlikely(err)) {
 457		kfree_skb(skb);
 458		return err;
 459	}
 460	sock_recv_timestamp(msg, sk, skb);
 461
 462	serr = SKB_EXT_ERR(skb);
 463
 464	if (sin && ipv6_datagram_support_addr(serr)) {
 465		const unsigned char *nh = skb_network_header(skb);
 466		sin->sin6_family = AF_INET6;
 467		sin->sin6_flowinfo = 0;
 468		sin->sin6_port = serr->port;
 469		if (skb->protocol == htons(ETH_P_IPV6)) {
 470			const struct ipv6hdr *ip6h = container_of((struct in6_addr *)(nh + serr->addr_offset),
 471								  struct ipv6hdr, daddr);
 472			sin->sin6_addr = ip6h->daddr;
 473			if (np->sndflow)
 474				sin->sin6_flowinfo = ip6_flowinfo(ip6h);
 475			sin->sin6_scope_id =
 476				ipv6_iface_scope_id(&sin->sin6_addr,
 477						    IP6CB(skb)->iif);
 478		} else {
 479			ipv6_addr_set_v4mapped(*(__be32 *)(nh + serr->addr_offset),
 480					       &sin->sin6_addr);
 481			sin->sin6_scope_id = 0;
 482		}
 483		*addr_len = sizeof(*sin);
 484	}
 485
 486	memcpy(&errhdr.ee, &serr->ee, sizeof(struct sock_extended_err));
 487	sin = &errhdr.offender;
 488	memset(sin, 0, sizeof(*sin));
 489
 490	if (ip6_datagram_support_cmsg(skb, serr)) {
 491		sin->sin6_family = AF_INET6;
 492		if (np->rxopt.all)
 493			ip6_datagram_recv_common_ctl(sk, msg, skb);
 494		if (skb->protocol == htons(ETH_P_IPV6)) {
 495			sin->sin6_addr = ipv6_hdr(skb)->saddr;
 496			if (np->rxopt.all)
 497				ip6_datagram_recv_specific_ctl(sk, msg, skb);
 498			sin->sin6_scope_id =
 499				ipv6_iface_scope_id(&sin->sin6_addr,
 500						    IP6CB(skb)->iif);
 501		} else {
 502			ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr,
 503					       &sin->sin6_addr);
 504			if (inet_sk(sk)->cmsg_flags)
 505				ip_cmsg_recv(msg, skb);
 506		}
 507	}
 508
 509	put_cmsg(msg, SOL_IPV6, IPV6_RECVERR, sizeof(errhdr), &errhdr);
 510
 511	/* Now we could try to dump offended packet options */
 512
 513	msg->msg_flags |= MSG_ERRQUEUE;
 514	err = copied;
 515
 516	consume_skb(skb);
 517out:
 518	return err;
 519}
 520EXPORT_SYMBOL_GPL(ipv6_recv_error);
 521
 522/*
 523 *	Handle IPV6_RECVPATHMTU
 524 */
 525int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 526		     int *addr_len)
 527{
 528	struct ipv6_pinfo *np = inet6_sk(sk);
 529	struct sk_buff *skb;
 530	struct ip6_mtuinfo mtu_info;
 531	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin, msg->msg_name);
 532	int err;
 533	int copied;
 534
 535	err = -EAGAIN;
 536	skb = xchg(&np->rxpmtu, NULL);
 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 (err)
 547		goto out_free_skb;
 548
 549	sock_recv_timestamp(msg, sk, skb);
 550
 551	memcpy(&mtu_info, IP6CBMTU(skb), sizeof(mtu_info));
 552
 553	if (sin) {
 554		sin->sin6_family = AF_INET6;
 555		sin->sin6_flowinfo = 0;
 556		sin->sin6_port = 0;
 557		sin->sin6_scope_id = mtu_info.ip6m_addr.sin6_scope_id;
 558		sin->sin6_addr = mtu_info.ip6m_addr.sin6_addr;
 559		*addr_len = sizeof(*sin);
 560	}
 561
 562	put_cmsg(msg, SOL_IPV6, IPV6_PATHMTU, sizeof(mtu_info), &mtu_info);
 563
 564	err = copied;
 565
 566out_free_skb:
 567	kfree_skb(skb);
 568out:
 569	return err;
 570}
 571
 572
 573void ip6_datagram_recv_common_ctl(struct sock *sk, struct msghdr *msg,
 574				 struct sk_buff *skb)
 575{
 576	struct ipv6_pinfo *np = inet6_sk(sk);
 577	bool is_ipv6 = skb->protocol == htons(ETH_P_IPV6);
 578
 579	if (np->rxopt.bits.rxinfo) {
 580		struct in6_pktinfo src_info;
 581
 582		if (is_ipv6) {
 583			src_info.ipi6_ifindex = IP6CB(skb)->iif;
 584			src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 585		} else {
 586			src_info.ipi6_ifindex =
 587				PKTINFO_SKB_CB(skb)->ipi_ifindex;
 588			ipv6_addr_set_v4mapped(ip_hdr(skb)->daddr,
 589					       &src_info.ipi6_addr);
 590		}
 591
 592		if (src_info.ipi6_ifindex >= 0)
 593			put_cmsg(msg, SOL_IPV6, IPV6_PKTINFO,
 594				 sizeof(src_info), &src_info);
 595	}
 596}
 597
 598void ip6_datagram_recv_specific_ctl(struct sock *sk, struct msghdr *msg,
 599				    struct sk_buff *skb)
 600{
 601	struct ipv6_pinfo *np = inet6_sk(sk);
 602	struct inet6_skb_parm *opt = IP6CB(skb);
 603	unsigned char *nh = skb_network_header(skb);
 604
 605	if (np->rxopt.bits.rxhlim) {
 606		int hlim = ipv6_hdr(skb)->hop_limit;
 607		put_cmsg(msg, SOL_IPV6, IPV6_HOPLIMIT, sizeof(hlim), &hlim);
 608	}
 609
 610	if (np->rxopt.bits.rxtclass) {
 611		int tclass = ipv6_get_dsfield(ipv6_hdr(skb));
 612		put_cmsg(msg, SOL_IPV6, IPV6_TCLASS, sizeof(tclass), &tclass);
 613	}
 614
 615	if (np->rxopt.bits.rxflow) {
 616		__be32 flowinfo = ip6_flowinfo((struct ipv6hdr *)nh);
 617		if (flowinfo)
 618			put_cmsg(msg, SOL_IPV6, IPV6_FLOWINFO, sizeof(flowinfo), &flowinfo);
 619	}
 620
 621	/* HbH is allowed only once */
 622	if (np->rxopt.bits.hopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 623		u8 *ptr = nh + sizeof(struct ipv6hdr);
 624		put_cmsg(msg, SOL_IPV6, IPV6_HOPOPTS, (ptr[1]+1)<<3, ptr);
 625	}
 626
 627	if (opt->lastopt &&
 628	    (np->rxopt.bits.dstopts || np->rxopt.bits.srcrt)) {
 629		/*
 630		 * Silly enough, but we need to reparse in order to
 631		 * report extension headers (except for HbH)
 632		 * in order.
 633		 *
 634		 * Also note that IPV6_RECVRTHDRDSTOPTS is NOT
 635		 * (and WILL NOT be) defined because
 636		 * IPV6_RECVDSTOPTS is more generic. --yoshfuji
 637		 */
 638		unsigned int off = sizeof(struct ipv6hdr);
 639		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 640
 641		while (off <= opt->lastopt) {
 642			unsigned int len;
 643			u8 *ptr = nh + off;
 644
 645			switch (nexthdr) {
 646			case IPPROTO_DSTOPTS:
 647				nexthdr = ptr[0];
 648				len = (ptr[1] + 1) << 3;
 649				if (np->rxopt.bits.dstopts)
 650					put_cmsg(msg, SOL_IPV6, IPV6_DSTOPTS, len, ptr);
 651				break;
 652			case IPPROTO_ROUTING:
 653				nexthdr = ptr[0];
 654				len = (ptr[1] + 1) << 3;
 655				if (np->rxopt.bits.srcrt)
 656					put_cmsg(msg, SOL_IPV6, IPV6_RTHDR, len, ptr);
 657				break;
 658			case IPPROTO_AH:
 659				nexthdr = ptr[0];
 660				len = (ptr[1] + 2) << 2;
 661				break;
 662			default:
 663				nexthdr = ptr[0];
 664				len = (ptr[1] + 1) << 3;
 665				break;
 666			}
 667
 668			off += len;
 669		}
 670	}
 671
 672	/* socket options in old style */
 673	if (np->rxopt.bits.rxoinfo) {
 674		struct in6_pktinfo src_info;
 675
 676		src_info.ipi6_ifindex = opt->iif;
 677		src_info.ipi6_addr = ipv6_hdr(skb)->daddr;
 678		put_cmsg(msg, SOL_IPV6, IPV6_2292PKTINFO, sizeof(src_info), &src_info);
 679	}
 680	if (np->rxopt.bits.rxohlim) {
 681		int hlim = ipv6_hdr(skb)->hop_limit;
 682		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPLIMIT, sizeof(hlim), &hlim);
 683	}
 684	if (np->rxopt.bits.ohopopts && (opt->flags & IP6SKB_HOPBYHOP)) {
 685		u8 *ptr = nh + sizeof(struct ipv6hdr);
 686		put_cmsg(msg, SOL_IPV6, IPV6_2292HOPOPTS, (ptr[1]+1)<<3, ptr);
 687	}
 688	if (np->rxopt.bits.odstopts && opt->dst0) {
 689		u8 *ptr = nh + opt->dst0;
 690		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 691	}
 692	if (np->rxopt.bits.osrcrt && opt->srcrt) {
 693		struct ipv6_rt_hdr *rthdr = (struct ipv6_rt_hdr *)(nh + opt->srcrt);
 694		put_cmsg(msg, SOL_IPV6, IPV6_2292RTHDR, (rthdr->hdrlen+1) << 3, rthdr);
 695	}
 696	if (np->rxopt.bits.odstopts && opt->dst1) {
 697		u8 *ptr = nh + opt->dst1;
 698		put_cmsg(msg, SOL_IPV6, IPV6_2292DSTOPTS, (ptr[1]+1)<<3, ptr);
 699	}
 700	if (np->rxopt.bits.rxorigdstaddr) {
 701		struct sockaddr_in6 sin6;
 702		__be16 _ports[2], *ports;
 703
 704		ports = skb_header_pointer(skb, skb_transport_offset(skb),
 705					   sizeof(_ports), &_ports);
 706		if (ports) {
 707			/* All current transport protocols have the port numbers in the
 708			 * first four bytes of the transport header and this function is
 709			 * written with this assumption in mind.
 710			 */
 
 711			sin6.sin6_family = AF_INET6;
 712			sin6.sin6_addr = ipv6_hdr(skb)->daddr;
 713			sin6.sin6_port = ports[1];
 714			sin6.sin6_flowinfo = 0;
 715			sin6.sin6_scope_id =
 716				ipv6_iface_scope_id(&ipv6_hdr(skb)->daddr,
 717						    opt->iif);
 718
 719			put_cmsg(msg, SOL_IPV6, IPV6_ORIGDSTADDR, sizeof(sin6), &sin6);
 720		}
 721	}
 722	if (np->rxopt.bits.recvfragsize && opt->frag_max_size) {
 723		int val = opt->frag_max_size;
 724
 725		put_cmsg(msg, SOL_IPV6, IPV6_RECVFRAGSIZE, sizeof(val), &val);
 726	}
 727}
 728
 729void ip6_datagram_recv_ctl(struct sock *sk, struct msghdr *msg,
 730			  struct sk_buff *skb)
 731{
 732	ip6_datagram_recv_common_ctl(sk, msg, skb);
 733	ip6_datagram_recv_specific_ctl(sk, msg, skb);
 734}
 735EXPORT_SYMBOL_GPL(ip6_datagram_recv_ctl);
 736
 737int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
 738			  struct msghdr *msg, struct flowi6 *fl6,
 739			  struct ipcm6_cookie *ipc6)
 740{
 741	struct in6_pktinfo *src_info;
 742	struct cmsghdr *cmsg;
 743	struct ipv6_rt_hdr *rthdr;
 744	struct ipv6_opt_hdr *hdr;
 745	struct ipv6_txoptions *opt = ipc6->opt;
 746	int len;
 747	int err = 0;
 748
 749	for_each_cmsghdr(cmsg, msg) {
 750		int addr_type;
 751
 752		if (!CMSG_OK(msg, cmsg)) {
 753			err = -EINVAL;
 754			goto exit_f;
 755		}
 756
 757		if (cmsg->cmsg_level == SOL_SOCKET) {
 758			err = __sock_cmsg_send(sk, msg, cmsg, &ipc6->sockc);
 759			if (err)
 760				return err;
 761			continue;
 762		}
 763
 764		if (cmsg->cmsg_level != SOL_IPV6)
 765			continue;
 766
 767		switch (cmsg->cmsg_type) {
 768		case IPV6_PKTINFO:
 769		case IPV6_2292PKTINFO:
 770		    {
 771			struct net_device *dev = NULL;
 772			int src_idx;
 773
 774			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct in6_pktinfo))) {
 775				err = -EINVAL;
 776				goto exit_f;
 777			}
 778
 779			src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg);
 780			src_idx = src_info->ipi6_ifindex;
 781
 782			if (src_idx) {
 783				if (fl6->flowi6_oif &&
 784				    src_idx != fl6->flowi6_oif &&
 785				    (sk->sk_bound_dev_if != fl6->flowi6_oif ||
 786				     !sk_dev_equal_l3scope(sk, src_idx)))
 787					return -EINVAL;
 788				fl6->flowi6_oif = src_idx;
 789			}
 790
 791			addr_type = __ipv6_addr_type(&src_info->ipi6_addr);
 792
 793			rcu_read_lock();
 794			if (fl6->flowi6_oif) {
 795				dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
 796				if (!dev) {
 797					rcu_read_unlock();
 798					return -ENODEV;
 799				}
 800			} else if (addr_type & IPV6_ADDR_LINKLOCAL) {
 801				rcu_read_unlock();
 802				return -EINVAL;
 803			}
 804
 805			if (addr_type != IPV6_ADDR_ANY) {
 806				int strict = __ipv6_addr_src_scope(addr_type) <= IPV6_ADDR_SCOPE_LINKLOCAL;
 807				if (!ipv6_can_nonlocal_bind(net, inet_sk(sk)) &&
 808				    !ipv6_chk_addr_and_flags(net, &src_info->ipi6_addr,
 809							     dev, !strict, 0,
 810							     IFA_F_TENTATIVE) &&
 811				    !ipv6_chk_acast_addr_src(net, dev,
 812							     &src_info->ipi6_addr))
 813					err = -EINVAL;
 814				else
 815					fl6->saddr = src_info->ipi6_addr;
 816			}
 817
 818			rcu_read_unlock();
 819
 820			if (err)
 821				goto exit_f;
 822
 823			break;
 824		    }
 825
 826		case IPV6_FLOWINFO:
 827			if (cmsg->cmsg_len < CMSG_LEN(4)) {
 828				err = -EINVAL;
 829				goto exit_f;
 830			}
 831
 832			if (fl6->flowlabel&IPV6_FLOWINFO_MASK) {
 833				if ((fl6->flowlabel^*(__be32 *)CMSG_DATA(cmsg))&~IPV6_FLOWINFO_MASK) {
 834					err = -EINVAL;
 835					goto exit_f;
 836				}
 837			}
 838			fl6->flowlabel = IPV6_FLOWINFO_MASK & *(__be32 *)CMSG_DATA(cmsg);
 839			break;
 840
 841		case IPV6_2292HOPOPTS:
 842		case IPV6_HOPOPTS:
 843			if (opt->hopopt || cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 844				err = -EINVAL;
 845				goto exit_f;
 846			}
 847
 848			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 849			len = ((hdr->hdrlen + 1) << 3);
 850			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 851				err = -EINVAL;
 852				goto exit_f;
 853			}
 854			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 855				err = -EPERM;
 856				goto exit_f;
 857			}
 858			opt->opt_nflen += len;
 859			opt->hopopt = hdr;
 860			break;
 861
 862		case IPV6_2292DSTOPTS:
 863			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 864				err = -EINVAL;
 865				goto exit_f;
 866			}
 867
 868			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 869			len = ((hdr->hdrlen + 1) << 3);
 870			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 871				err = -EINVAL;
 872				goto exit_f;
 873			}
 874			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 875				err = -EPERM;
 876				goto exit_f;
 877			}
 878			if (opt->dst1opt) {
 879				err = -EINVAL;
 880				goto exit_f;
 881			}
 882			opt->opt_flen += len;
 883			opt->dst1opt = hdr;
 884			break;
 885
 886		case IPV6_DSTOPTS:
 887		case IPV6_RTHDRDSTOPTS:
 888			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_opt_hdr))) {
 889				err = -EINVAL;
 890				goto exit_f;
 891			}
 892
 893			hdr = (struct ipv6_opt_hdr *)CMSG_DATA(cmsg);
 894			len = ((hdr->hdrlen + 1) << 3);
 895			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 896				err = -EINVAL;
 897				goto exit_f;
 898			}
 899			if (!ns_capable(net->user_ns, CAP_NET_RAW)) {
 900				err = -EPERM;
 901				goto exit_f;
 902			}
 903			if (cmsg->cmsg_type == IPV6_DSTOPTS) {
 904				opt->opt_flen += len;
 905				opt->dst1opt = hdr;
 906			} else {
 907				opt->opt_nflen += len;
 908				opt->dst0opt = hdr;
 909			}
 910			break;
 911
 912		case IPV6_2292RTHDR:
 913		case IPV6_RTHDR:
 914			if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct ipv6_rt_hdr))) {
 915				err = -EINVAL;
 916				goto exit_f;
 917			}
 918
 919			rthdr = (struct ipv6_rt_hdr *)CMSG_DATA(cmsg);
 920
 921			switch (rthdr->type) {
 922#if IS_ENABLED(CONFIG_IPV6_MIP6)
 923			case IPV6_SRCRT_TYPE_2:
 924				if (rthdr->hdrlen != 2 ||
 925				    rthdr->segments_left != 1) {
 926					err = -EINVAL;
 927					goto exit_f;
 928				}
 929				break;
 930#endif
 931			default:
 932				err = -EINVAL;
 933				goto exit_f;
 934			}
 935
 936			len = ((rthdr->hdrlen + 1) << 3);
 937
 938			if (cmsg->cmsg_len < CMSG_LEN(len)) {
 939				err = -EINVAL;
 940				goto exit_f;
 941			}
 942
 943			/* segments left must also match */
 944			if ((rthdr->hdrlen >> 1) != rthdr->segments_left) {
 945				err = -EINVAL;
 946				goto exit_f;
 947			}
 948
 949			opt->opt_nflen += len;
 950			opt->srcrt = rthdr;
 951
 952			if (cmsg->cmsg_type == IPV6_2292RTHDR && opt->dst1opt) {
 953				int dsthdrlen = ((opt->dst1opt->hdrlen+1)<<3);
 954
 955				opt->opt_nflen += dsthdrlen;
 956				opt->dst0opt = opt->dst1opt;
 957				opt->dst1opt = NULL;
 958				opt->opt_flen -= dsthdrlen;
 959			}
 960
 961			break;
 962
 963		case IPV6_2292HOPLIMIT:
 964		case IPV6_HOPLIMIT:
 965			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) {
 966				err = -EINVAL;
 967				goto exit_f;
 968			}
 969
 970			ipc6->hlimit = *(int *)CMSG_DATA(cmsg);
 971			if (ipc6->hlimit < -1 || ipc6->hlimit > 0xff) {
 972				err = -EINVAL;
 973				goto exit_f;
 974			}
 975
 976			break;
 977
 978		case IPV6_TCLASS:
 979		    {
 980			int tc;
 981
 982			err = -EINVAL;
 983			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
 984				goto exit_f;
 985
 986			tc = *(int *)CMSG_DATA(cmsg);
 987			if (tc < -1 || tc > 0xff)
 988				goto exit_f;
 989
 990			err = 0;
 991			ipc6->tclass = tc;
 992
 993			break;
 994		    }
 995
 996		case IPV6_DONTFRAG:
 997		    {
 998			int df;
 999
1000			err = -EINVAL;
1001			if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)))
1002				goto exit_f;
1003
1004			df = *(int *)CMSG_DATA(cmsg);
1005			if (df < 0 || df > 1)
1006				goto exit_f;
1007
1008			err = 0;
1009			ipc6->dontfrag = df;
1010
1011			break;
1012		    }
1013		default:
1014			net_dbg_ratelimited("invalid cmsg type: %d\n",
1015					    cmsg->cmsg_type);
1016			err = -EINVAL;
1017			goto exit_f;
1018		}
1019	}
1020
1021exit_f:
1022	return err;
1023}
1024EXPORT_SYMBOL_GPL(ip6_datagram_send_ctl);
1025
1026void __ip6_dgram_sock_seq_show(struct seq_file *seq, struct sock *sp,
1027			       __u16 srcp, __u16 destp, int rqueue, int bucket)
1028{
1029	const struct in6_addr *dest, *src;
1030
1031	dest  = &sp->sk_v6_daddr;
1032	src   = &sp->sk_v6_rcv_saddr;
1033	seq_printf(seq,
1034		   "%5d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
1035		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %u\n",
1036		   bucket,
1037		   src->s6_addr32[0], src->s6_addr32[1],
1038		   src->s6_addr32[2], src->s6_addr32[3], srcp,
1039		   dest->s6_addr32[0], dest->s6_addr32[1],
1040		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
1041		   sp->sk_state,
1042		   sk_wmem_alloc_get(sp),
1043		   rqueue,
1044		   0, 0L, 0,
1045		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
1046		   0,
1047		   sock_i_ino(sp),
1048		   refcount_read(&sp->sk_refcnt), sp,
1049		   atomic_read(&sp->sk_drops));
1050}