ipv6.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* SCTP kernel implementation
   3 * (C) Copyright IBM Corp. 2002, 2004
   4 * Copyright (c) 2001 Nokia, Inc.
   5 * Copyright (c) 2001 La Monte H.P. Yarroll
   6 * Copyright (c) 2002-2003 Intel Corp.
   7 *
   8 * This file is part of the SCTP kernel implementation
   9 *
  10 * SCTP over IPv6.
  11 *
  12 * Please send any bug reports or fixes you make to the
  13 * email address(es):
  14 *    lksctp developers <linux-sctp@vger.kernel.org>
  15 *
  16 * Written or modified by:
  17 *    Le Yanqun		    <yanqun.le@nokia.com>
  18 *    Hui Huang		    <hui.huang@nokia.com>
  19 *    La Monte H.P. Yarroll <piggy@acm.org>
  20 *    Sridhar Samudrala	    <sri@us.ibm.com>
  21 *    Jon Grimm		    <jgrimm@us.ibm.com>
  22 *    Ardelle Fan	    <ardelle.fan@intel.com>
  23 *
  24 * Based on:
  25 *	linux/net/ipv6/tcp_ipv6.c
  26 */
  27
  28#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  29
  30#include <linux/module.h>
  31#include <linux/errno.h>
  32#include <linux/types.h>
  33#include <linux/socket.h>
  34#include <linux/sockios.h>
  35#include <linux/net.h>
  36#include <linux/in.h>
  37#include <linux/in6.h>
  38#include <linux/netdevice.h>
  39#include <linux/init.h>
  40#include <linux/ipsec.h>
  41#include <linux/slab.h>
  42
  43#include <linux/ipv6.h>
  44#include <linux/icmpv6.h>
  45#include <linux/random.h>
  46#include <linux/seq_file.h>
  47
  48#include <net/protocol.h>
  49#include <net/ndisc.h>
  50#include <net/ip.h>
  51#include <net/ipv6.h>
  52#include <net/transp_v6.h>
  53#include <net/addrconf.h>
  54#include <net/ip6_route.h>
  55#include <net/inet_common.h>
  56#include <net/inet_ecn.h>
  57#include <net/sctp/sctp.h>
  58#include <net/udp_tunnel.h>
  59
  60#include <linux/uaccess.h>
  61
  62static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
  63					 union sctp_addr *s2);
  64static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
  65			      __be16 port);
  66static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
  67			    const union sctp_addr *addr2);
  68
  69/* Event handler for inet6 address addition/deletion events.
  70 * The sctp_local_addr_list needs to be protocted by a spin lock since
  71 * multiple notifiers (say IPv4 and IPv6) may be running at the same
  72 * time and thus corrupt the list.
  73 * The reader side is protected with RCU.
  74 */
  75static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
  76				void *ptr)
  77{
  78	struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
  79	struct sctp_sockaddr_entry *addr = NULL;
  80	struct sctp_sockaddr_entry *temp;
  81	struct net *net = dev_net(ifa->idev->dev);
  82	int found = 0;
  83
  84	switch (ev) {
  85	case NETDEV_UP:
  86		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
  87		if (addr) {
  88			addr->a.v6.sin6_family = AF_INET6;
  89			addr->a.v6.sin6_addr = ifa->addr;
  90			addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
  91			addr->valid = 1;
  92			spin_lock_bh(&net->sctp.local_addr_lock);
  93			list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
  94			sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
  95			spin_unlock_bh(&net->sctp.local_addr_lock);
  96		}
  97		break;
  98	case NETDEV_DOWN:
  99		spin_lock_bh(&net->sctp.local_addr_lock);
 100		list_for_each_entry_safe(addr, temp,
 101					&net->sctp.local_addr_list, list) {
 102			if (addr->a.sa.sa_family == AF_INET6 &&
 103			    ipv6_addr_equal(&addr->a.v6.sin6_addr,
 104					    &ifa->addr) &&
 105			    addr->a.v6.sin6_scope_id == ifa->idev->dev->ifindex) {
 106				found = 1;
 107				addr->valid = 0;
 108				list_del_rcu(&addr->list);
 109				sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
 110				break;
 111			}
 112		}
 113		spin_unlock_bh(&net->sctp.local_addr_lock);
 114		if (found)
 115			kfree_rcu(addr, rcu);
 116		break;
 117	}
 118
 119	return NOTIFY_DONE;
 120}
 121
 122static struct notifier_block sctp_inet6addr_notifier = {
 123	.notifier_call = sctp_inet6addr_event,
 124};
 125
 126static void sctp_v6_err_handle(struct sctp_transport *t, struct sk_buff *skb,
 127			       __u8 type, __u8 code, __u32 info)
 128{
 129	struct sctp_association *asoc = t->asoc;
 130	struct sock *sk = asoc->base.sk;
 131	int err = 0;
 132
 133	switch (type) {
 134	case ICMPV6_PKT_TOOBIG:
 135		if (ip6_sk_accept_pmtu(sk))
 136			sctp_icmp_frag_needed(sk, asoc, t, info);
 137		return;
 138	case ICMPV6_PARAMPROB:
 139		if (ICMPV6_UNK_NEXTHDR == code) {
 140			sctp_icmp_proto_unreachable(sk, asoc, t);
 141			return;
 142		}
 143		break;
 144	case NDISC_REDIRECT:
 145		sctp_icmp_redirect(sk, t, skb);
 146		return;
 147	default:
 148		break;
 149	}
 150
 151	icmpv6_err_convert(type, code, &err);
 152	if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
 153		sk->sk_err = err;
 154		sk_error_report(sk);
 155	} else {
 156		WRITE_ONCE(sk->sk_err_soft, err);
 157	}
 158}
 159
 160/* ICMP error handler. */
 161static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 162		       u8 type, u8 code, int offset, __be32 info)
 163{
 164	struct net *net = dev_net(skb->dev);
 165	struct sctp_transport *transport;
 166	struct sctp_association *asoc;
 167	__u16 saveip, savesctp;
 168	struct sock *sk;
 169
 170	/* Fix up skb to look at the embedded net header. */
 171	saveip	 = skb->network_header;
 172	savesctp = skb->transport_header;
 173	skb_reset_network_header(skb);
 174	skb_set_transport_header(skb, offset);
 175	sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
 176	/* Put back, the original pointers. */
 177	skb->network_header   = saveip;
 178	skb->transport_header = savesctp;
 179	if (!sk) {
 180		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 181		return -ENOENT;
 182	}
 183
 184	sctp_v6_err_handle(transport, skb, type, code, ntohl(info));
 185	sctp_err_finish(sk, transport);
 186
 187	return 0;
 188}
 189
 190int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb)
 191{
 192	struct net *net = dev_net(skb->dev);
 193	struct sctp_association *asoc;
 194	struct sctp_transport *t;
 195	struct icmp6hdr *hdr;
 196	__u32 info = 0;
 197
 198	skb->transport_header += sizeof(struct udphdr);
 199	sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t);
 200	if (!sk) {
 201		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
 202		return -ENOENT;
 203	}
 204
 205	skb->transport_header -= sizeof(struct udphdr);
 206	hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr));
 207	if (hdr->icmp6_type == NDISC_REDIRECT) {
 208		/* can't be handled without outer ip6hdr known, leave it to udpv6_err */
 209		sctp_err_finish(sk, t);
 210		return 0;
 211	}
 212	if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG)
 213		info = ntohl(hdr->icmp6_mtu);
 214	sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info);
 215
 216	sctp_err_finish(sk, t);
 217	return 1;
 218}
 219
 220static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t)
 221{
 222	struct dst_entry *dst = dst_clone(t->dst);
 223	struct flowi6 *fl6 = &t->fl.u.ip6;
 224	struct sock *sk = skb->sk;
 225	struct ipv6_pinfo *np = inet6_sk(sk);
 226	__u8 tclass = np->tclass;
 227	__be32 label;
 228
 229	pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
 230		 skb->len, &fl6->saddr, &fl6->daddr);
 231
 232	if (t->dscp & SCTP_DSCP_SET_MASK)
 233		tclass = t->dscp & SCTP_DSCP_VAL_MASK;
 234
 235	if (INET_ECN_is_capable(tclass))
 236		IP6_ECN_flow_xmit(sk, fl6->flowlabel);
 237
 238	if (!(t->param_flags & SPP_PMTUD_ENABLE))
 239		skb->ignore_df = 1;
 240
 241	SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
 242
 243	if (!t->encap_port || !sctp_sk(sk)->udp_port) {
 244		int res;
 245
 246		skb_dst_set(skb, dst);
 247		rcu_read_lock();
 248		res = ip6_xmit(sk, skb, fl6, sk->sk_mark,
 249			       rcu_dereference(np->opt),
 250			       tclass, READ_ONCE(sk->sk_priority));
 251		rcu_read_unlock();
 252		return res;
 253	}
 254
 255	if (skb_is_gso(skb))
 256		skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
 257
 258	skb->encapsulation = 1;
 259	skb_reset_inner_mac_header(skb);
 260	skb_reset_inner_transport_header(skb);
 261	skb_set_inner_ipproto(skb, IPPROTO_SCTP);
 262	label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6);
 263
 264	udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr, &fl6->daddr,
 265			     tclass, ip6_dst_hoplimit(dst), label,
 266			     sctp_sk(sk)->udp_port, t->encap_port, false, 0);
 267	return 0;
 268}
 269
 270/* Returns the dst cache entry for the given source and destination ip
 271 * addresses.
 272 */
 273static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
 274			    struct flowi *fl, struct sock *sk)
 275{
 276	struct sctp_association *asoc = t->asoc;
 277	struct dst_entry *dst = NULL;
 278	struct flowi _fl;
 279	struct flowi6 *fl6 = &_fl.u.ip6;
 280	struct sctp_bind_addr *bp;
 281	struct ipv6_pinfo *np = inet6_sk(sk);
 282	struct sctp_sockaddr_entry *laddr;
 283	union sctp_addr *daddr = &t->ipaddr;
 284	union sctp_addr dst_saddr;
 285	struct in6_addr *final_p, final;
 286	enum sctp_scope scope;
 287	__u8 matchlen = 0;
 288
 289	memset(&_fl, 0, sizeof(_fl));
 290	fl6->daddr = daddr->v6.sin6_addr;
 291	fl6->fl6_dport = daddr->v6.sin6_port;
 292	fl6->flowi6_proto = IPPROTO_SCTP;
 293	if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 294		fl6->flowi6_oif = daddr->v6.sin6_scope_id;
 295	else if (asoc)
 296		fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
 297	if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
 298		fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
 299
 300	if (inet6_test_bit(SNDFLOW, sk) &&
 301	    (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
 302		struct ip6_flowlabel *flowlabel;
 303
 304		flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
 305		if (IS_ERR(flowlabel))
 306			goto out;
 307		fl6_sock_release(flowlabel);
 308	}
 309
 310	pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
 311
 312	if (asoc)
 313		fl6->fl6_sport = htons(asoc->base.bind_addr.port);
 314
 315	if (saddr) {
 316		fl6->saddr = saddr->v6.sin6_addr;
 317		if (!fl6->fl6_sport)
 318			fl6->fl6_sport = saddr->v6.sin6_port;
 319
 320		pr_debug("src=%pI6 - ", &fl6->saddr);
 321	}
 322
 323	rcu_read_lock();
 324	final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 325	rcu_read_unlock();
 326
 327	dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 328	if (!asoc || saddr) {
 329		t->dst = dst;
 330		memcpy(fl, &_fl, sizeof(_fl));
 331		goto out;
 332	}
 333
 334	bp = &asoc->base.bind_addr;
 335	scope = sctp_scope(daddr);
 336	/* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
 337	 * to see if we can use it.
 338	 */
 339	if (!IS_ERR(dst)) {
 340		/* Walk through the bind address list and look for a bind
 341		 * address that matches the source address of the returned dst.
 342		 */
 343		sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
 344		rcu_read_lock();
 345		list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 346			if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
 347			    (laddr->state != SCTP_ADDR_SRC &&
 348			     !asoc->src_out_of_asoc_ok))
 349				continue;
 350
 351			/* Do not compare against v4 addrs */
 352			if ((laddr->a.sa.sa_family == AF_INET6) &&
 353			    (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
 354				rcu_read_unlock();
 355				t->dst = dst;
 356				memcpy(fl, &_fl, sizeof(_fl));
 357				goto out;
 358			}
 359		}
 360		rcu_read_unlock();
 361		/* None of the bound addresses match the source address of the
 362		 * dst. So release it.
 363		 */
 364		dst_release(dst);
 365		dst = NULL;
 366	}
 367
 368	/* Walk through the bind address list and try to get the
 369	 * best source address for a given destination.
 370	 */
 371	rcu_read_lock();
 372	list_for_each_entry_rcu(laddr, &bp->address_list, list) {
 373		struct dst_entry *bdst;
 374		__u8 bmatchlen;
 375
 376		if (!laddr->valid ||
 377		    laddr->state != SCTP_ADDR_SRC ||
 378		    laddr->a.sa.sa_family != AF_INET6 ||
 379		    scope > sctp_scope(&laddr->a))
 380			continue;
 381
 382		fl6->saddr = laddr->a.v6.sin6_addr;
 383		fl6->fl6_sport = laddr->a.v6.sin6_port;
 384		final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
 385		bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
 386
 387		if (IS_ERR(bdst))
 388			continue;
 389
 390		if (ipv6_chk_addr(dev_net(bdst->dev),
 391				  &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
 392			if (!IS_ERR_OR_NULL(dst))
 393				dst_release(dst);
 394			dst = bdst;
 395			t->dst = dst;
 396			memcpy(fl, &_fl, sizeof(_fl));
 397			break;
 398		}
 399
 400		bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 401		if (matchlen > bmatchlen) {
 402			dst_release(bdst);
 403			continue;
 404		}
 405
 406		if (!IS_ERR_OR_NULL(dst))
 407			dst_release(dst);
 408		dst = bdst;
 409		matchlen = bmatchlen;
 410		t->dst = dst;
 411		memcpy(fl, &_fl, sizeof(_fl));
 412	}
 413	rcu_read_unlock();
 414
 415out:
 416	if (!IS_ERR_OR_NULL(dst)) {
 417		struct rt6_info *rt;
 418
 419		rt = dst_rt6_info(dst);
 420		t->dst_cookie = rt6_get_cookie(rt);
 421		pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
 422			 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
 423			 &fl->u.ip6.saddr);
 424	} else {
 425		t->dst = NULL;
 426		pr_debug("no route\n");
 427	}
 428}
 429
 430/* Returns the number of consecutive initial bits that match in the 2 ipv6
 431 * addresses.
 432 */
 433static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 434					 union sctp_addr *s2)
 435{
 436	return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
 437}
 438
 439/* Fills in the source address(saddr) based on the destination address(daddr)
 440 * and asoc's bind address list.
 441 */
 442static void sctp_v6_get_saddr(struct sctp_sock *sk,
 443			      struct sctp_transport *t,
 444			      struct flowi *fl)
 445{
 446	struct flowi6 *fl6 = &fl->u.ip6;
 447	union sctp_addr *saddr = &t->saddr;
 448
 449	pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
 450
 451	if (t->dst) {
 452		saddr->v6.sin6_family = AF_INET6;
 453		saddr->v6.sin6_addr = fl6->saddr;
 454	}
 455}
 456
 457/* Make a copy of all potential local addresses. */
 458static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 459				  struct net_device *dev)
 460{
 461	struct inet6_dev *in6_dev;
 462	struct inet6_ifaddr *ifp;
 463	struct sctp_sockaddr_entry *addr;
 464
 465	rcu_read_lock();
 466	if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 467		rcu_read_unlock();
 468		return;
 469	}
 470
 471	read_lock_bh(&in6_dev->lock);
 472	list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
 473		/* Add the address to the local list.  */
 474		addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 475		if (addr) {
 476			addr->a.v6.sin6_family = AF_INET6;
 477			addr->a.v6.sin6_addr = ifp->addr;
 478			addr->a.v6.sin6_scope_id = dev->ifindex;
 479			addr->valid = 1;
 480			INIT_LIST_HEAD(&addr->list);
 481			list_add_tail(&addr->list, addrlist);
 482		}
 483	}
 484
 485	read_unlock_bh(&in6_dev->lock);
 486	rcu_read_unlock();
 487}
 488
 489/* Copy over any ip options */
 490static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
 491{
 492	struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 493	struct ipv6_txoptions *opt;
 494
 495	inet_sk(newsk)->inet_opt = NULL;
 496
 497	newnp = inet6_sk(newsk);
 498
 499	rcu_read_lock();
 500	opt = rcu_dereference(np->opt);
 501	if (opt) {
 502		opt = ipv6_dup_options(newsk, opt);
 503		if (!opt)
 504			pr_err("%s: Failed to copy ip options\n", __func__);
 505	}
 506	RCU_INIT_POINTER(newnp->opt, opt);
 507	rcu_read_unlock();
 508}
 509
 510/* Account for the IP options */
 511static int sctp_v6_ip_options_len(struct sock *sk)
 512{
 513	struct ipv6_pinfo *np = inet6_sk(sk);
 514	struct ipv6_txoptions *opt;
 515	int len = 0;
 516
 517	rcu_read_lock();
 518	opt = rcu_dereference(np->opt);
 519	if (opt)
 520		len = opt->opt_flen + opt->opt_nflen;
 521
 522	rcu_read_unlock();
 523	return len;
 524}
 525
 526/* Initialize a sockaddr_storage from in incoming skb. */
 527static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
 528			     int is_saddr)
 529{
 530	/* Always called on head skb, so this is safe */
 531	struct sctphdr *sh = sctp_hdr(skb);
 532	struct sockaddr_in6 *sa = &addr->v6;
 533
 534	addr->v6.sin6_family = AF_INET6;
 535	addr->v6.sin6_flowinfo = 0; /* FIXME */
 536	addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 537
 538	if (is_saddr) {
 539		sa->sin6_port = sh->source;
 540		sa->sin6_addr = ipv6_hdr(skb)->saddr;
 541	} else {
 542		sa->sin6_port = sh->dest;
 543		sa->sin6_addr = ipv6_hdr(skb)->daddr;
 544	}
 545}
 546
 547/* Initialize an sctp_addr from a socket. */
 548static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 549{
 550	addr->v6.sin6_family = AF_INET6;
 551	addr->v6.sin6_port = 0;
 552	addr->v6.sin6_flowinfo = 0;
 553	addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
 554	addr->v6.sin6_scope_id = 0;
 555}
 556
 557/* Initialize sk->sk_rcv_saddr from sctp_addr. */
 558static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 559{
 560	if (addr->sa.sa_family == AF_INET) {
 561		sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
 562		sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
 563		sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 564		sk->sk_v6_rcv_saddr.s6_addr32[3] =
 565			addr->v4.sin_addr.s_addr;
 566	} else {
 567		sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
 568	}
 569}
 570
 571/* Initialize sk->sk_daddr from sctp_addr. */
 572static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 573{
 574	if (addr->sa.sa_family == AF_INET) {
 575		sk->sk_v6_daddr.s6_addr32[0] = 0;
 576		sk->sk_v6_daddr.s6_addr32[1] = 0;
 577		sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
 578		sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 579	} else {
 580		sk->sk_v6_daddr = addr->v6.sin6_addr;
 581	}
 582}
 583
 584/* Initialize a sctp_addr from an address parameter. */
 585static bool sctp_v6_from_addr_param(union sctp_addr *addr,
 586				    union sctp_addr_param *param,
 587				    __be16 port, int iif)
 588{
 589	if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
 590		return false;
 591
 592	addr->v6.sin6_family = AF_INET6;
 593	addr->v6.sin6_port = port;
 594	addr->v6.sin6_flowinfo = 0; /* BUG */
 595	addr->v6.sin6_addr = param->v6.addr;
 596	addr->v6.sin6_scope_id = iif;
 597
 598	return true;
 599}
 600
 601/* Initialize an address parameter from a sctp_addr and return the length
 602 * of the address parameter.
 603 */
 604static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 605				 union sctp_addr_param *param)
 606{
 607	int length = sizeof(struct sctp_ipv6addr_param);
 608
 609	param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 610	param->v6.param_hdr.length = htons(length);
 611	param->v6.addr = addr->v6.sin6_addr;
 612
 613	return length;
 614}
 615
 616/* Initialize a sctp_addr from struct in6_addr. */
 617static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
 618			      __be16 port)
 619{
 620	addr->sa.sa_family = AF_INET6;
 621	addr->v6.sin6_port = port;
 622	addr->v6.sin6_flowinfo = 0;
 623	addr->v6.sin6_addr = *saddr;
 624	addr->v6.sin6_scope_id = 0;
 625}
 626
 627static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
 628			      const union sctp_addr *addr2)
 629{
 630	if (addr1->sa.sa_family != addr2->sa.sa_family) {
 631		if (addr1->sa.sa_family == AF_INET &&
 632		    addr2->sa.sa_family == AF_INET6 &&
 633		    ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
 634		    addr2->v6.sin6_addr.s6_addr32[3] ==
 635		    addr1->v4.sin_addr.s_addr)
 636			return 1;
 637
 638		if (addr2->sa.sa_family == AF_INET &&
 639		    addr1->sa.sa_family == AF_INET6 &&
 640		    ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
 641		    addr1->v6.sin6_addr.s6_addr32[3] ==
 642		    addr2->v4.sin_addr.s_addr)
 643			return 1;
 644
 645		return 0;
 646	}
 647
 648	if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 649		return 0;
 650
 651	/* If this is a linklocal address, compare the scope_id. */
 652	if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
 653	    addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 654	    addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
 655		return 0;
 656
 657	return 1;
 658}
 659
 660/* Compare addresses exactly.
 661 * v4-mapped-v6 is also in consideration.
 662 */
 663static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 664			    const union sctp_addr *addr2)
 665{
 666	return __sctp_v6_cmp_addr(addr1, addr2) &&
 667	       addr1->v6.sin6_port == addr2->v6.sin6_port;
 668}
 669
 670/* Initialize addr struct to INADDR_ANY. */
 671static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
 672{
 673	memset(addr, 0x00, sizeof(union sctp_addr));
 674	addr->v6.sin6_family = AF_INET6;
 675	addr->v6.sin6_port = port;
 676}
 677
 678/* Is this a wildcard address? */
 679static int sctp_v6_is_any(const union sctp_addr *addr)
 680{
 681	return ipv6_addr_any(&addr->v6.sin6_addr);
 682}
 683
 684/* Should this be available for binding?   */
 685static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
 686{
 687	const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
 688	struct sock *sk = &sp->inet.sk;
 689	struct net *net = sock_net(sk);
 690	struct net_device *dev = NULL;
 691	int type, res, bound_dev_if;
 692
 693	type = ipv6_addr_type(in6);
 694	if (IPV6_ADDR_ANY == type)
 695		return 1;
 696	if (type == IPV6_ADDR_MAPPED) {
 697		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 698			return 0;
 699		sctp_v6_map_v4(addr);
 700		return sctp_get_af_specific(AF_INET)->available(addr, sp);
 701	}
 702	if (!(type & IPV6_ADDR_UNICAST))
 703		return 0;
 704
 705	rcu_read_lock();
 706	bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
 707	if (bound_dev_if) {
 708		res = 0;
 709		dev = dev_get_by_index_rcu(net, bound_dev_if);
 710		if (!dev)
 711			goto out;
 712	}
 713
 714	res = ipv6_can_nonlocal_bind(net, &sp->inet) ||
 715	      ipv6_chk_addr(net, in6, dev, 0);
 716
 717out:
 718	rcu_read_unlock();
 719	return res;
 720}
 721
 722/* This function checks if the address is a valid address to be used for
 723 * SCTP.
 724 *
 725 * Output:
 726 * Return 0 - If the address is a non-unicast or an illegal address.
 727 * Return 1 - If the address is a unicast.
 728 */
 729static int sctp_v6_addr_valid(union sctp_addr *addr,
 730			      struct sctp_sock *sp,
 731			      const struct sk_buff *skb)
 732{
 733	int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 734
 735	/* Support v4-mapped-v6 address. */
 736	if (ret == IPV6_ADDR_MAPPED) {
 737		/* Note: This routine is used in input, so v4-mapped-v6
 738		 * are disallowed here when there is no sctp_sock.
 739		 */
 740		if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 741			return 0;
 742		sctp_v6_map_v4(addr);
 743		return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
 744	}
 745
 746	/* Is this a non-unicast address */
 747	if (!(ret & IPV6_ADDR_UNICAST))
 748		return 0;
 749
 750	return 1;
 751}
 752
 753/* What is the scope of 'addr'?  */
 754static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
 755{
 756	enum sctp_scope retval;
 757	int v6scope;
 758
 759	/* The IPv6 scope is really a set of bit fields.
 760	 * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 761	 */
 762
 763	v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 764	switch (v6scope) {
 765	case IFA_HOST:
 766		retval = SCTP_SCOPE_LOOPBACK;
 767		break;
 768	case IFA_LINK:
 769		retval = SCTP_SCOPE_LINK;
 770		break;
 771	case IFA_SITE:
 772		retval = SCTP_SCOPE_PRIVATE;
 773		break;
 774	default:
 775		retval = SCTP_SCOPE_GLOBAL;
 776		break;
 777	}
 778
 779	return retval;
 780}
 781
 782/* Format a sockaddr for return to user space. This makes sure the return is
 783 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
 784 */
 785static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
 786{
 787	if (sp->v4mapped) {
 788		if (addr->sa.sa_family == AF_INET)
 789			sctp_v4_map_v6(addr);
 790	} else {
 791		if (addr->sa.sa_family == AF_INET6 &&
 792		    ipv6_addr_v4mapped(&addr->v6.sin6_addr))
 793			sctp_v6_map_v4(addr);
 794	}
 795
 796	if (addr->sa.sa_family == AF_INET) {
 797		memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
 798		return sizeof(struct sockaddr_in);
 799	}
 800	return sizeof(struct sockaddr_in6);
 801}
 802
 803/* Where did this skb come from?  */
 804static int sctp_v6_skb_iif(const struct sk_buff *skb)
 805{
 806	return inet6_iif(skb);
 807}
 808
 809static int sctp_v6_skb_sdif(const struct sk_buff *skb)
 810{
 811	return inet6_sdif(skb);
 812}
 813
 814/* Was this packet marked by Explicit Congestion Notification? */
 815static int sctp_v6_is_ce(const struct sk_buff *skb)
 816{
 817	return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
 818}
 819
 820/* Dump the v6 addr to the seq file. */
 821static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 822{
 823	seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
 824}
 825
 826static void sctp_v6_ecn_capable(struct sock *sk)
 827{
 828	inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
 829}
 830
 831/* Initialize a PF_INET msgname from a ulpevent. */
 832static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 833				     char *msgname, int *addrlen)
 834{
 835	union sctp_addr *addr;
 836	struct sctp_association *asoc;
 837	union sctp_addr *paddr;
 838
 839	if (!msgname)
 840		return;
 841
 842	addr = (union sctp_addr *)msgname;
 843	asoc = event->asoc;
 844	paddr = &asoc->peer.primary_addr;
 845
 846	if (paddr->sa.sa_family == AF_INET) {
 847		addr->v4.sin_family = AF_INET;
 848		addr->v4.sin_port = htons(asoc->peer.port);
 849		addr->v4.sin_addr = paddr->v4.sin_addr;
 850	} else {
 851		addr->v6.sin6_family = AF_INET6;
 852		addr->v6.sin6_flowinfo = 0;
 853		if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 854			addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
 855		else
 856			addr->v6.sin6_scope_id = 0;
 857		addr->v6.sin6_port = htons(asoc->peer.port);
 858		addr->v6.sin6_addr = paddr->v6.sin6_addr;
 859	}
 860
 861	*addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
 862}
 863
 864/* Initialize a msg_name from an inbound skb. */
 865static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 866				   int *addr_len)
 867{
 868	union sctp_addr *addr;
 869	struct sctphdr *sh;
 870
 871	if (!msgname)
 872		return;
 873
 874	addr = (union sctp_addr *)msgname;
 875	sh = sctp_hdr(skb);
 876
 877	if (ip_hdr(skb)->version == 4) {
 878		addr->v4.sin_family = AF_INET;
 879		addr->v4.sin_port = sh->source;
 880		addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
 881	} else {
 882		addr->v6.sin6_family = AF_INET6;
 883		addr->v6.sin6_flowinfo = 0;
 884		addr->v6.sin6_port = sh->source;
 885		addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
 886		if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 887			addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
 888		else
 889			addr->v6.sin6_scope_id = 0;
 890	}
 891
 892	*addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
 893}
 894
 895/* Do we support this AF? */
 896static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
 897{
 898	switch (family) {
 899	case AF_INET6:
 900		return 1;
 901	/* v4-mapped-v6 addresses */
 902	case AF_INET:
 903		if (!ipv6_only_sock(sctp_opt2sk(sp)))
 904			return 1;
 905		fallthrough;
 906	default:
 907		return 0;
 908	}
 909}
 910
 911/* Address matching with wildcards allowed.  This extra level
 912 * of indirection lets us choose whether a PF_INET6 should
 913 * disallow any v4 addresses if we so choose.
 914 */
 915static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 916			       const union sctp_addr *addr2,
 917			       struct sctp_sock *opt)
 918{
 919	struct sock *sk = sctp_opt2sk(opt);
 920	struct sctp_af *af1, *af2;
 921
 922	af1 = sctp_get_af_specific(addr1->sa.sa_family);
 923	af2 = sctp_get_af_specific(addr2->sa.sa_family);
 924
 925	if (!af1 || !af2)
 926		return 0;
 927
 928	/* If the socket is IPv6 only, v4 addrs will not match */
 929	if (ipv6_only_sock(sk) && af1 != af2)
 930		return 0;
 931
 932	/* Today, wildcard AF_INET/AF_INET6. */
 933	if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
 934		return 1;
 935
 936	if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
 937		return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
 938
 939	return __sctp_v6_cmp_addr(addr1, addr2);
 940}
 941
 942/* Verify that the provided sockaddr looks bindable.   Common verification,
 943 * has already been taken care of.
 944 */
 945static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
 946{
 947	struct sctp_af *af;
 948
 949	/* ASSERT: address family has already been verified. */
 950	if (addr->sa.sa_family != AF_INET6)
 951		af = sctp_get_af_specific(addr->sa.sa_family);
 952	else {
 953		int type = ipv6_addr_type(&addr->v6.sin6_addr);
 954		struct net_device *dev;
 955
 956		if (type & IPV6_ADDR_LINKLOCAL) {
 957			struct net *net;
 958			if (!addr->v6.sin6_scope_id)
 959				return 0;
 960			net = sock_net(&opt->inet.sk);
 961			rcu_read_lock();
 962			dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
 963			if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) ||
 964				      ipv6_chk_addr(net, &addr->v6.sin6_addr,
 965						    dev, 0))) {
 966				rcu_read_unlock();
 967				return 0;
 968			}
 969			rcu_read_unlock();
 970		}
 971
 972		af = opt->pf->af;
 973	}
 974	return af->available(addr, opt);
 975}
 976
 977/* Verify that the provided sockaddr looks sendable.   Common verification,
 978 * has already been taken care of.
 979 */
 980static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
 981{
 982	struct sctp_af *af = NULL;
 983
 984	/* ASSERT: address family has already been verified. */
 985	if (addr->sa.sa_family != AF_INET6)
 986		af = sctp_get_af_specific(addr->sa.sa_family);
 987	else {
 988		int type = ipv6_addr_type(&addr->v6.sin6_addr);
 989		struct net_device *dev;
 990
 991		if (type & IPV6_ADDR_LINKLOCAL) {
 992			if (!addr->v6.sin6_scope_id)
 993				return 0;
 994			rcu_read_lock();
 995			dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
 996						   addr->v6.sin6_scope_id);
 997			rcu_read_unlock();
 998			if (!dev)
 999				return 0;
1000		}
1001		af = opt->pf->af;
1002	}
1003
1004	return af != NULL;
1005}
1006
1007/* Fill in Supported Address Type information for INIT and INIT-ACK
1008 * chunks.   Note: In the future, we may want to look at sock options
1009 * to determine whether a PF_INET6 socket really wants to have IPV4
1010 * addresses.
1011 * Returns number of addresses supported.
1012 */
1013static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
1014				      __be16 *types)
1015{
1016	types[0] = SCTP_PARAM_IPV6_ADDRESS;
1017	if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1018		types[1] = SCTP_PARAM_IPV4_ADDRESS;
1019		return 2;
1020	}
1021	return 1;
1022}
1023
1024/* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1025static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1026			int peer)
1027{
1028	int rc;
1029
1030	rc = inet6_getname(sock, uaddr, peer);
1031
1032	if (rc < 0)
1033		return rc;
1034
1035	rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1036					  (union sctp_addr *)uaddr);
1037
1038	return rc;
1039}
1040
1041static const struct proto_ops inet6_seqpacket_ops = {
1042	.family		   = PF_INET6,
1043	.owner		   = THIS_MODULE,
1044	.release	   = inet6_release,
1045	.bind		   = inet6_bind,
1046	.connect	   = sctp_inet_connect,
1047	.socketpair	   = sock_no_socketpair,
1048	.accept		   = inet_accept,
1049	.getname	   = sctp_getname,
1050	.poll		   = sctp_poll,
1051	.ioctl		   = inet6_ioctl,
1052	.gettstamp	   = sock_gettstamp,
1053	.listen		   = sctp_inet_listen,
1054	.shutdown	   = inet_shutdown,
1055	.setsockopt	   = sock_common_setsockopt,
1056	.getsockopt	   = sock_common_getsockopt,
1057	.sendmsg	   = inet_sendmsg,
1058	.recvmsg	   = inet_recvmsg,
1059	.mmap		   = sock_no_mmap,
1060#ifdef CONFIG_COMPAT
1061	.compat_ioctl	   = inet6_compat_ioctl,
1062#endif
1063};
1064
1065static struct inet_protosw sctpv6_seqpacket_protosw = {
1066	.type          = SOCK_SEQPACKET,
1067	.protocol      = IPPROTO_SCTP,
1068	.prot 	       = &sctpv6_prot,
1069	.ops           = &inet6_seqpacket_ops,
1070	.flags         = SCTP_PROTOSW_FLAG
1071};
1072static struct inet_protosw sctpv6_stream_protosw = {
1073	.type          = SOCK_STREAM,
1074	.protocol      = IPPROTO_SCTP,
1075	.prot 	       = &sctpv6_prot,
1076	.ops           = &inet6_seqpacket_ops,
1077	.flags         = SCTP_PROTOSW_FLAG,
1078};
1079
1080static int sctp6_rcv(struct sk_buff *skb)
1081{
1082	SCTP_INPUT_CB(skb)->encap_port = 0;
1083	return sctp_rcv(skb) ? -1 : 0;
1084}
1085
1086static const struct inet6_protocol sctpv6_protocol = {
1087	.handler      = sctp6_rcv,
1088	.err_handler  = sctp_v6_err,
1089	.flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1090};
1091
1092static struct sctp_af sctp_af_inet6 = {
1093	.sa_family	   = AF_INET6,
1094	.sctp_xmit	   = sctp_v6_xmit,
1095	.setsockopt	   = ipv6_setsockopt,
1096	.getsockopt	   = ipv6_getsockopt,
1097	.get_dst	   = sctp_v6_get_dst,
1098	.get_saddr	   = sctp_v6_get_saddr,
1099	.copy_addrlist	   = sctp_v6_copy_addrlist,
1100	.from_skb	   = sctp_v6_from_skb,
1101	.from_sk	   = sctp_v6_from_sk,
1102	.from_addr_param   = sctp_v6_from_addr_param,
1103	.to_addr_param	   = sctp_v6_to_addr_param,
1104	.cmp_addr	   = sctp_v6_cmp_addr,
1105	.scope		   = sctp_v6_scope,
1106	.addr_valid	   = sctp_v6_addr_valid,
1107	.inaddr_any	   = sctp_v6_inaddr_any,
1108	.is_any		   = sctp_v6_is_any,
1109	.available	   = sctp_v6_available,
1110	.skb_iif	   = sctp_v6_skb_iif,
1111	.skb_sdif	   = sctp_v6_skb_sdif,
1112	.is_ce		   = sctp_v6_is_ce,
1113	.seq_dump_addr	   = sctp_v6_seq_dump_addr,
1114	.ecn_capable	   = sctp_v6_ecn_capable,
1115	.net_header_len	   = sizeof(struct ipv6hdr),
1116	.sockaddr_len	   = sizeof(struct sockaddr_in6),
1117	.ip_options_len	   = sctp_v6_ip_options_len,
1118};
1119
1120static struct sctp_pf sctp_pf_inet6 = {
1121	.event_msgname = sctp_inet6_event_msgname,
1122	.skb_msgname   = sctp_inet6_skb_msgname,
1123	.af_supported  = sctp_inet6_af_supported,
1124	.cmp_addr      = sctp_inet6_cmp_addr,
1125	.bind_verify   = sctp_inet6_bind_verify,
1126	.send_verify   = sctp_inet6_send_verify,
1127	.supported_addrs = sctp_inet6_supported_addrs,
1128	.addr_to_user  = sctp_v6_addr_to_user,
1129	.to_sk_saddr   = sctp_v6_to_sk_saddr,
1130	.to_sk_daddr   = sctp_v6_to_sk_daddr,
1131	.copy_ip_options = sctp_v6_copy_ip_options,
1132	.af            = &sctp_af_inet6,
1133};
1134
1135/* Initialize IPv6 support and register with socket layer.  */
1136void sctp_v6_pf_init(void)
1137{
1138	/* Register the SCTP specific PF_INET6 functions. */
1139	sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1140
1141	/* Register the SCTP specific AF_INET6 functions. */
1142	sctp_register_af(&sctp_af_inet6);
1143}
1144
1145void sctp_v6_pf_exit(void)
1146{
1147	list_del(&sctp_af_inet6.list);
1148}
1149
1150/* Initialize IPv6 support and register with socket layer.  */
1151int sctp_v6_protosw_init(void)
1152{
1153	int rc;
1154
1155	rc = proto_register(&sctpv6_prot, 1);
1156	if (rc)
1157		return rc;
1158
1159	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1160	inet6_register_protosw(&sctpv6_seqpacket_protosw);
1161	inet6_register_protosw(&sctpv6_stream_protosw);
1162
1163	return 0;
1164}
1165
1166void sctp_v6_protosw_exit(void)
1167{
1168	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1169	inet6_unregister_protosw(&sctpv6_stream_protosw);
1170	proto_unregister(&sctpv6_prot);
1171}
1172
1173
1174/* Register with inet6 layer. */
1175int sctp_v6_add_protocol(void)
1176{
1177	/* Register notifier for inet6 address additions/deletions. */
1178	register_inet6addr_notifier(&sctp_inet6addr_notifier);
1179
1180	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1181		return -EAGAIN;
1182
1183	return 0;
1184}
1185
1186/* Unregister with inet6 layer. */
1187void sctp_v6_del_protocol(void)
1188{
1189	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1190	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1191}