1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *	TCP over IPv6
   4 *	Linux INET6 implementation
   5 *
   6 *	Authors:
   7 *	Pedro Roque		<roque@di.fc.ul.pt>
   8 *
   9 *	Based on:
  10 *	linux/net/ipv4/tcp.c
  11 *	linux/net/ipv4/tcp_input.c
  12 *	linux/net/ipv4/tcp_output.c
  13 *
  14 *	Fixes:
  15 *	Hideaki YOSHIFUJI	:	sin6_scope_id support
  16 *	YOSHIFUJI Hideaki @USAGI and:	Support IPV6_V6ONLY socket option, which
  17 *	Alexey Kuznetsov		allow both IPv4 and IPv6 sockets to bind
  18 *					a single port at the same time.
  19 *	YOSHIFUJI Hideaki @USAGI:	convert /proc/net/tcp6 to seq_file.
  20 */
  21
  22#include <linux/bottom_half.h>
  23#include <linux/module.h>
  24#include <linux/errno.h>
  25#include <linux/types.h>
  26#include <linux/socket.h>
  27#include <linux/sockios.h>
  28#include <linux/net.h>
  29#include <linux/jiffies.h>
  30#include <linux/in.h>
  31#include <linux/in6.h>
  32#include <linux/netdevice.h>
  33#include <linux/init.h>
  34#include <linux/jhash.h>
  35#include <linux/ipsec.h>
  36#include <linux/times.h>
  37#include <linux/slab.h>
  38#include <linux/uaccess.h>
  39#include <linux/ipv6.h>
  40#include <linux/icmpv6.h>
  41#include <linux/random.h>
  42#include <linux/indirect_call_wrapper.h>
  43
  44#include <net/tcp.h>
  45#include <net/ndisc.h>
  46#include <net/inet6_hashtables.h>
  47#include <net/inet6_connection_sock.h>
  48#include <net/ipv6.h>
  49#include <net/transp_v6.h>
  50#include <net/addrconf.h>
  51#include <net/ip6_route.h>
  52#include <net/ip6_checksum.h>
  53#include <net/inet_ecn.h>
  54#include <net/protocol.h>
  55#include <net/xfrm.h>
  56#include <net/snmp.h>
  57#include <net/dsfield.h>
  58#include <net/timewait_sock.h>
  59#include <net/inet_common.h>
  60#include <net/secure_seq.h>
  61#include <net/hotdata.h>
  62#include <net/busy_poll.h>
  63
  64#include <linux/proc_fs.h>
  65#include <linux/seq_file.h>
  66
  67#include <crypto/hash.h>
  68#include <linux/scatterlist.h>
  69
  70#include <trace/events/tcp.h>
  71
  72static void	tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
  73static void	tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
  74				      struct request_sock *req);
  75
  76INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
  77
  78static const struct inet_connection_sock_af_ops ipv6_mapped;
  79const struct inet_connection_sock_af_ops ipv6_specific;
  80#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
  81static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
  82static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
 
 
 
 
 
 
 
  83#endif
  84
  85/* Helper returning the inet6 address from a given tcp socket.
  86 * It can be used in TCP stack instead of inet6_sk(sk).
  87 * This avoids a dereference and allow compiler optimizations.
  88 * It is a specialized version of inet6_sk_generic().
  89 */
  90#define tcp_inet6_sk(sk) (&container_of_const(tcp_sk(sk), \
  91					      struct tcp6_sock, tcp)->inet6)
 
 
 
 
  92
  93static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
  94{
  95	struct dst_entry *dst = skb_dst(skb);
  96
  97	if (dst && dst_hold_safe(dst)) {
 
 
  98		rcu_assign_pointer(sk->sk_rx_dst, dst);
  99		sk->sk_rx_dst_ifindex = skb->skb_iif;
 100		sk->sk_rx_dst_cookie = rt6_get_cookie(dst_rt6_info(dst));
 101	}
 102}
 103
 104static u32 tcp_v6_init_seq(const struct sk_buff *skb)
 105{
 106	return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
 107				ipv6_hdr(skb)->saddr.s6_addr32,
 108				tcp_hdr(skb)->dest,
 109				tcp_hdr(skb)->source);
 110}
 111
 112static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
 113{
 114	return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
 115				   ipv6_hdr(skb)->saddr.s6_addr32);
 116}
 117
 118static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
 119			      int addr_len)
 120{
 121	/* This check is replicated from tcp_v6_connect() and intended to
 122	 * prevent BPF program called below from accessing bytes that are out
 123	 * of the bound specified by user in addr_len.
 124	 */
 125	if (addr_len < SIN6_LEN_RFC2133)
 126		return -EINVAL;
 127
 128	sock_owned_by_me(sk);
 129
 130	return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr, &addr_len);
 131}
 132
 133static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 134			  int addr_len)
 135{
 136	struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
 137	struct inet_connection_sock *icsk = inet_csk(sk);
 138	struct in6_addr *saddr = NULL, *final_p, final;
 139	struct inet_timewait_death_row *tcp_death_row;
 140	struct ipv6_pinfo *np = tcp_inet6_sk(sk);
 141	struct inet_sock *inet = inet_sk(sk);
 142	struct tcp_sock *tp = tcp_sk(sk);
 143	struct net *net = sock_net(sk);
 144	struct ipv6_txoptions *opt;
 145	struct dst_entry *dst;
 146	struct flowi6 fl6;
 147	int addr_type;
 148	int err;
 149
 150	if (addr_len < SIN6_LEN_RFC2133)
 151		return -EINVAL;
 152
 153	if (usin->sin6_family != AF_INET6)
 154		return -EAFNOSUPPORT;
 155
 156	memset(&fl6, 0, sizeof(fl6));
 157
 158	if (inet6_test_bit(SNDFLOW, sk)) {
 159		fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
 160		IP6_ECN_flow_init(fl6.flowlabel);
 161		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
 162			struct ip6_flowlabel *flowlabel;
 163			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
 164			if (IS_ERR(flowlabel))
 165				return -EINVAL;
 166			fl6_sock_release(flowlabel);
 167		}
 168	}
 169
 170	/*
 171	 *	connect() to INADDR_ANY means loopback (BSD'ism).
 172	 */
 173
 174	if (ipv6_addr_any(&usin->sin6_addr)) {
 175		if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
 176			ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
 177					       &usin->sin6_addr);
 178		else
 179			usin->sin6_addr = in6addr_loopback;
 180	}
 181
 182	addr_type = ipv6_addr_type(&usin->sin6_addr);
 183
 184	if (addr_type & IPV6_ADDR_MULTICAST)
 185		return -ENETUNREACH;
 186
 187	if (addr_type&IPV6_ADDR_LINKLOCAL) {
 188		if (addr_len >= sizeof(struct sockaddr_in6) &&
 189		    usin->sin6_scope_id) {
 190			/* If interface is set while binding, indices
 191			 * must coincide.
 192			 */
 193			if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
 194				return -EINVAL;
 195
 196			sk->sk_bound_dev_if = usin->sin6_scope_id;
 197		}
 198
 199		/* Connect to link-local address requires an interface */
 200		if (!sk->sk_bound_dev_if)
 201			return -EINVAL;
 202	}
 203
 204	if (tp->rx_opt.ts_recent_stamp &&
 205	    !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
 206		tp->rx_opt.ts_recent = 0;
 207		tp->rx_opt.ts_recent_stamp = 0;
 208		WRITE_ONCE(tp->write_seq, 0);
 209	}
 210
 211	sk->sk_v6_daddr = usin->sin6_addr;
 212	np->flow_label = fl6.flowlabel;
 213
 214	/*
 215	 *	TCP over IPv4
 216	 */
 217
 218	if (addr_type & IPV6_ADDR_MAPPED) {
 219		u32 exthdrlen = icsk->icsk_ext_hdr_len;
 220		struct sockaddr_in sin;
 221
 222		if (ipv6_only_sock(sk))
 223			return -ENETUNREACH;
 224
 225		sin.sin_family = AF_INET;
 226		sin.sin_port = usin->sin6_port;
 227		sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
 228
 229		/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
 230		WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped);
 231		if (sk_is_mptcp(sk))
 232			mptcpv6_handle_mapped(sk, true);
 233		sk->sk_backlog_rcv = tcp_v4_do_rcv;
 234#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
 235		tp->af_specific = &tcp_sock_ipv6_mapped_specific;
 236#endif
 237
 238		err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
 239
 240		if (err) {
 241			icsk->icsk_ext_hdr_len = exthdrlen;
 242			/* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
 243			WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific);
 244			if (sk_is_mptcp(sk))
 245				mptcpv6_handle_mapped(sk, false);
 246			sk->sk_backlog_rcv = tcp_v6_do_rcv;
 247#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
 248			tp->af_specific = &tcp_sock_ipv6_specific;
 249#endif
 250			goto failure;
 251		}
 252		np->saddr = sk->sk_v6_rcv_saddr;
 253
 254		return err;
 255	}
 256
 257	if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
 258		saddr = &sk->sk_v6_rcv_saddr;
 259
 260	fl6.flowi6_proto = IPPROTO_TCP;
 261	fl6.daddr = sk->sk_v6_daddr;
 262	fl6.saddr = saddr ? *saddr : np->saddr;
 263	fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
 264	fl6.flowi6_oif = sk->sk_bound_dev_if;
 265	fl6.flowi6_mark = sk->sk_mark;
 266	fl6.fl6_dport = usin->sin6_port;
 267	fl6.fl6_sport = inet->inet_sport;
 268	fl6.flowi6_uid = sk->sk_uid;
 269
 270	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
 271	final_p = fl6_update_dst(&fl6, opt, &final);
 272
 273	security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
 274
 275	dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
 276	if (IS_ERR(dst)) {
 277		err = PTR_ERR(dst);
 278		goto failure;
 279	}
 280
 281	tp->tcp_usec_ts = dst_tcp_usec_ts(dst);
 282	tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
 283
 284	if (!saddr) {
 285		saddr = &fl6.saddr;
 286
 287		err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
 288		if (err)
 289			goto failure;
 290	}
 291
 292	/* set the source address */
 293	np->saddr = *saddr;
 294	inet->inet_rcv_saddr = LOOPBACK4_IPV6;
 295
 296	sk->sk_gso_type = SKB_GSO_TCPV6;
 297	ip6_dst_store(sk, dst, NULL, NULL);
 298
 299	icsk->icsk_ext_hdr_len = 0;
 300	if (opt)
 301		icsk->icsk_ext_hdr_len = opt->opt_flen +
 302					 opt->opt_nflen;
 303
 304	tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 305
 306	inet->inet_dport = usin->sin6_port;
 307
 308	tcp_set_state(sk, TCP_SYN_SENT);
 309	err = inet6_hash_connect(tcp_death_row, sk);
 310	if (err)
 311		goto late_failure;
 312
 313	sk_set_txhash(sk);
 314
 315	if (likely(!tp->repair)) {
 316		if (!tp->write_seq)
 317			WRITE_ONCE(tp->write_seq,
 318				   secure_tcpv6_seq(np->saddr.s6_addr32,
 319						    sk->sk_v6_daddr.s6_addr32,
 320						    inet->inet_sport,
 321						    inet->inet_dport));
 322		tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32,
 323						   sk->sk_v6_daddr.s6_addr32);
 324	}
 325
 326	if (tcp_fastopen_defer_connect(sk, &err))
 327		return err;
 328	if (err)
 329		goto late_failure;
 330
 331	err = tcp_connect(sk);
 332	if (err)
 333		goto late_failure;
 334
 335	return 0;
 336
 337late_failure:
 338	tcp_set_state(sk, TCP_CLOSE);
 339	inet_bhash2_reset_saddr(sk);
 340failure:
 341	inet->inet_dport = 0;
 342	sk->sk_route_caps = 0;
 343	return err;
 344}
 345
 346static void tcp_v6_mtu_reduced(struct sock *sk)
 347{
 348	struct dst_entry *dst;
 349	u32 mtu;
 350
 351	if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
 352		return;
 353
 354	mtu = READ_ONCE(tcp_sk(sk)->mtu_info);
 355
 356	/* Drop requests trying to increase our current mss.
 357	 * Check done in __ip6_rt_update_pmtu() is too late.
 358	 */
 359	if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache)
 360		return;
 361
 362	dst = inet6_csk_update_pmtu(sk, mtu);
 363	if (!dst)
 364		return;
 365
 366	if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
 367		tcp_sync_mss(sk, dst_mtu(dst));
 368		tcp_simple_retransmit(sk);
 369	}
 370}
 371
 372static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 373		u8 type, u8 code, int offset, __be32 info)
 374{
 375	const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
 376	const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
 377	struct net *net = dev_net(skb->dev);
 378	struct request_sock *fastopen;
 379	struct ipv6_pinfo *np;
 380	struct tcp_sock *tp;
 381	__u32 seq, snd_una;
 382	struct sock *sk;
 383	bool fatal;
 384	int err;
 385
 386	sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
 387					&hdr->daddr, th->dest,
 388					&hdr->saddr, ntohs(th->source),
 389					skb->dev->ifindex, inet6_sdif(skb));
 390
 391	if (!sk) {
 392		__ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
 393				  ICMP6_MIB_INERRORS);
 394		return -ENOENT;
 395	}
 396
 397	if (sk->sk_state == TCP_TIME_WAIT) {
 398		/* To increase the counter of ignored icmps for TCP-AO */
 399		tcp_ao_ignore_icmp(sk, AF_INET6, type, code);
 400		inet_twsk_put(inet_twsk(sk));
 401		return 0;
 402	}
 403	seq = ntohl(th->seq);
 404	fatal = icmpv6_err_convert(type, code, &err);
 405	if (sk->sk_state == TCP_NEW_SYN_RECV) {
 406		tcp_req_err(sk, seq, fatal);
 407		return 0;
 408	}
 409
 410	if (tcp_ao_ignore_icmp(sk, AF_INET6, type, code)) {
 411		sock_put(sk);
 412		return 0;
 413	}
 414
 415	bh_lock_sock(sk);
 416	if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
 417		__NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
 418
 419	if (sk->sk_state == TCP_CLOSE)
 420		goto out;
 421
 422	if (static_branch_unlikely(&ip6_min_hopcount)) {
 423		/* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
 424		if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) {
 425			__NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
 426			goto out;
 427		}
 428	}
 429
 430	tp = tcp_sk(sk);
 431	/* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
 432	fastopen = rcu_dereference(tp->fastopen_rsk);
 433	snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
 434	if (sk->sk_state != TCP_LISTEN &&
 435	    !between(seq, snd_una, tp->snd_nxt)) {
 436		__NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
 437		goto out;
 438	}
 439
 440	np = tcp_inet6_sk(sk);
 441
 442	if (type == NDISC_REDIRECT) {
 443		if (!sock_owned_by_user(sk)) {
 444			struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
 445
 446			if (dst)
 447				dst->ops->redirect(dst, sk, skb);
 448		}
 449		goto out;
 450	}
 451
 452	if (type == ICMPV6_PKT_TOOBIG) {
 453		u32 mtu = ntohl(info);
 454
 455		/* We are not interested in TCP_LISTEN and open_requests
 456		 * (SYN-ACKs send out by Linux are always <576bytes so
 457		 * they should go through unfragmented).
 458		 */
 459		if (sk->sk_state == TCP_LISTEN)
 460			goto out;
 461
 462		if (!ip6_sk_accept_pmtu(sk))
 463			goto out;
 464
 465		if (mtu < IPV6_MIN_MTU)
 466			goto out;
 467
 468		WRITE_ONCE(tp->mtu_info, mtu);
 469
 470		if (!sock_owned_by_user(sk))
 471			tcp_v6_mtu_reduced(sk);
 472		else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
 473					   &sk->sk_tsq_flags))
 474			sock_hold(sk);
 475		goto out;
 476	}
 477
 478
 479	/* Might be for an request_sock */
 480	switch (sk->sk_state) {
 481	case TCP_SYN_SENT:
 482	case TCP_SYN_RECV:
 483		/* Only in fast or simultaneous open. If a fast open socket is
 484		 * already accepted it is treated as a connected one below.
 485		 */
 486		if (fastopen && !fastopen->sk)
 487			break;
 488
 489		ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
 490
 491		if (!sock_owned_by_user(sk)) {
 492			WRITE_ONCE(sk->sk_err, err);
 493			sk_error_report(sk);		/* Wake people up to see the error (see connect in sock.c) */
 494
 495			tcp_done(sk);
 496		} else {
 497			WRITE_ONCE(sk->sk_err_soft, err);
 498		}
 499		goto out;
 500	case TCP_LISTEN:
 501		break;
 502	default:
 503		/* check if this ICMP message allows revert of backoff.
 504		 * (see RFC 6069)
 505		 */
 506		if (!fastopen && type == ICMPV6_DEST_UNREACH &&
 507		    code == ICMPV6_NOROUTE)
 508			tcp_ld_RTO_revert(sk, seq);
 509	}
 510
 511	if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
 512		WRITE_ONCE(sk->sk_err, err);
 513		sk_error_report(sk);
 514	} else {
 515		WRITE_ONCE(sk->sk_err_soft, err);
 516	}
 517out:
 518	bh_unlock_sock(sk);
 519	sock_put(sk);
 520	return 0;
 521}
 522
 523
 524static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
 525			      struct flowi *fl,
 526			      struct request_sock *req,
 527			      struct tcp_fastopen_cookie *foc,
 528			      enum tcp_synack_type synack_type,
 529			      struct sk_buff *syn_skb)
 530{
 531	struct inet_request_sock *ireq = inet_rsk(req);
 532	const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
 533	struct ipv6_txoptions *opt;
 534	struct flowi6 *fl6 = &fl->u.ip6;
 535	struct sk_buff *skb;
 536	int err = -ENOMEM;
 537	u8 tclass;
 538
 539	/* First, grab a route. */
 540	if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
 541					       IPPROTO_TCP)) == NULL)
 542		goto done;
 543
 544	skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
 545
 546	if (skb) {
 547		__tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
 548				    &ireq->ir_v6_rmt_addr);
 549
 550		fl6->daddr = ireq->ir_v6_rmt_addr;
 551		if (inet6_test_bit(REPFLOW, sk) && ireq->pktopts)
 552			fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
 553
 554		tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
 555				(tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
 556				(np->tclass & INET_ECN_MASK) :
 557				np->tclass;
 558
 559		if (!INET_ECN_is_capable(tclass) &&
 560		    tcp_bpf_ca_needs_ecn((struct sock *)req))
 561			tclass |= INET_ECN_ECT_0;
 562
 563		rcu_read_lock();
 564		opt = ireq->ipv6_opt;
 565		if (!opt)
 566			opt = rcu_dereference(np->opt);
 567		err = ip6_xmit(sk, skb, fl6, skb->mark ? : READ_ONCE(sk->sk_mark),
 568			       opt, tclass, READ_ONCE(sk->sk_priority));
 569		rcu_read_unlock();
 570		err = net_xmit_eval(err);
 571	}
 572
 573done:
 574	return err;
 575}
 576
 577
 578static void tcp_v6_reqsk_destructor(struct request_sock *req)
 579{
 580	kfree(inet_rsk(req)->ipv6_opt);
 581	consume_skb(inet_rsk(req)->pktopts);
 582}
 583
 584#ifdef CONFIG_TCP_MD5SIG
 585static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
 586						   const struct in6_addr *addr,
 587						   int l3index)
 588{
 589	return tcp_md5_do_lookup(sk, l3index,
 590				 (union tcp_md5_addr *)addr, AF_INET6);
 591}
 592
 593static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
 594						const struct sock *addr_sk)
 595{
 596	int l3index;
 597
 598	l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
 599						 addr_sk->sk_bound_dev_if);
 600	return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
 601				    l3index);
 602}
 603
 604static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
 605				 sockptr_t optval, int optlen)
 606{
 607	struct tcp_md5sig cmd;
 608	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
 609	union tcp_ao_addr *addr;
 610	int l3index = 0;
 611	u8 prefixlen;
 612	bool l3flag;
 613	u8 flags;
 614
 615	if (optlen < sizeof(cmd))
 616		return -EINVAL;
 617
 618	if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
 619		return -EFAULT;
 620
 621	if (sin6->sin6_family != AF_INET6)
 622		return -EINVAL;
 623
 624	flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
 625	l3flag = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
 626
 627	if (optname == TCP_MD5SIG_EXT &&
 628	    cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
 629		prefixlen = cmd.tcpm_prefixlen;
 630		if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
 631					prefixlen > 32))
 632			return -EINVAL;
 633	} else {
 634		prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
 635	}
 636
 637	if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
 638	    cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
 639		struct net_device *dev;
 640
 641		rcu_read_lock();
 642		dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
 643		if (dev && netif_is_l3_master(dev))
 644			l3index = dev->ifindex;
 645		rcu_read_unlock();
 646
 647		/* ok to reference set/not set outside of rcu;
 648		 * right now device MUST be an L3 master
 649		 */
 650		if (!dev || !l3index)
 651			return -EINVAL;
 652	}
 653
 654	if (!cmd.tcpm_keylen) {
 655		if (ipv6_addr_v4mapped(&sin6->sin6_addr))
 656			return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
 657					      AF_INET, prefixlen,
 658					      l3index, flags);
 659		return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
 660				      AF_INET6, prefixlen, l3index, flags);
 661	}
 662
 663	if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
 664		return -EINVAL;
 665
 666	if (ipv6_addr_v4mapped(&sin6->sin6_addr)) {
 667		addr = (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3];
 668
 669		/* Don't allow keys for peers that have a matching TCP-AO key.
 670		 * See the comment in tcp_ao_add_cmd()
 671		 */
 672		if (tcp_ao_required(sk, addr, AF_INET,
 673				    l3flag ? l3index : -1, false))
 674			return -EKEYREJECTED;
 675		return tcp_md5_do_add(sk, addr,
 676				      AF_INET, prefixlen, l3index, flags,
 677				      cmd.tcpm_key, cmd.tcpm_keylen);
 678	}
 679
 680	addr = (union tcp_md5_addr *)&sin6->sin6_addr;
 681
 682	/* Don't allow keys for peers that have a matching TCP-AO key.
 683	 * See the comment in tcp_ao_add_cmd()
 684	 */
 685	if (tcp_ao_required(sk, addr, AF_INET6, l3flag ? l3index : -1, false))
 686		return -EKEYREJECTED;
 687
 688	return tcp_md5_do_add(sk, addr, AF_INET6, prefixlen, l3index, flags,
 689			      cmd.tcpm_key, cmd.tcpm_keylen);
 690}
 691
 692static int tcp_v6_md5_hash_headers(struct tcp_sigpool *hp,
 693				   const struct in6_addr *daddr,
 694				   const struct in6_addr *saddr,
 695				   const struct tcphdr *th, int nbytes)
 696{
 697	struct tcp6_pseudohdr *bp;
 698	struct scatterlist sg;
 699	struct tcphdr *_th;
 700
 701	bp = hp->scratch;
 702	/* 1. TCP pseudo-header (RFC2460) */
 703	bp->saddr = *saddr;
 704	bp->daddr = *daddr;
 705	bp->protocol = cpu_to_be32(IPPROTO_TCP);
 706	bp->len = cpu_to_be32(nbytes);
 707
 708	_th = (struct tcphdr *)(bp + 1);
 709	memcpy(_th, th, sizeof(*th));
 710	_th->check = 0;
 711
 712	sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
 713	ahash_request_set_crypt(hp->req, &sg, NULL,
 714				sizeof(*bp) + sizeof(*th));
 715	return crypto_ahash_update(hp->req);
 716}
 717
 718static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
 719			       const struct in6_addr *daddr, struct in6_addr *saddr,
 720			       const struct tcphdr *th)
 721{
 722	struct tcp_sigpool hp;
 
 723
 724	if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
 725		goto clear_hash_nostart;
 
 
 726
 727	if (crypto_ahash_init(hp.req))
 728		goto clear_hash;
 729	if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, th->doff << 2))
 730		goto clear_hash;
 731	if (tcp_md5_hash_key(&hp, key))
 732		goto clear_hash;
 733	ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
 734	if (crypto_ahash_final(hp.req))
 735		goto clear_hash;
 736
 737	tcp_sigpool_end(&hp);
 738	return 0;
 739
 740clear_hash:
 741	tcp_sigpool_end(&hp);
 742clear_hash_nostart:
 743	memset(md5_hash, 0, 16);
 744	return 1;
 745}
 746
 747static int tcp_v6_md5_hash_skb(char *md5_hash,
 748			       const struct tcp_md5sig_key *key,
 749			       const struct sock *sk,
 750			       const struct sk_buff *skb)
 751{
 752	const struct tcphdr *th = tcp_hdr(skb);
 753	const struct in6_addr *saddr, *daddr;
 754	struct tcp_sigpool hp;
 
 
 755
 756	if (sk) { /* valid for establish/request sockets */
 757		saddr = &sk->sk_v6_rcv_saddr;
 758		daddr = &sk->sk_v6_daddr;
 759	} else {
 760		const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 761		saddr = &ip6h->saddr;
 762		daddr = &ip6h->daddr;
 763	}
 764
 765	if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp))
 766		goto clear_hash_nostart;
 
 
 767
 768	if (crypto_ahash_init(hp.req))
 769		goto clear_hash;
 770
 771	if (tcp_v6_md5_hash_headers(&hp, daddr, saddr, th, skb->len))
 772		goto clear_hash;
 773	if (tcp_sigpool_hash_skb_data(&hp, skb, th->doff << 2))
 774		goto clear_hash;
 775	if (tcp_md5_hash_key(&hp, key))
 776		goto clear_hash;
 777	ahash_request_set_crypt(hp.req, NULL, md5_hash, 0);
 778	if (crypto_ahash_final(hp.req))
 779		goto clear_hash;
 780
 781	tcp_sigpool_end(&hp);
 782	return 0;
 783
 784clear_hash:
 785	tcp_sigpool_end(&hp);
 786clear_hash_nostart:
 787	memset(md5_hash, 0, 16);
 788	return 1;
 789}
 
 790#endif
 791
 792static void tcp_v6_init_req(struct request_sock *req,
 793			    const struct sock *sk_listener,
 794			    struct sk_buff *skb)
 795{
 796	bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
 797	struct inet_request_sock *ireq = inet_rsk(req);
 798	const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
 799
 800	ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 801	ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
 802
 803	/* So that link locals have meaning */
 804	if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
 805	    ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
 806		ireq->ir_iif = tcp_v6_iif(skb);
 807
 808	if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
 809	    (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
 810	     np->rxopt.bits.rxinfo ||
 811	     np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
 812	     np->rxopt.bits.rxohlim || inet6_test_bit(REPFLOW, sk_listener))) {
 813		refcount_inc(&skb->users);
 814		ireq->pktopts = skb;
 815	}
 816}
 817
 818static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
 819					  struct sk_buff *skb,
 820					  struct flowi *fl,
 821					  struct request_sock *req)
 822{
 823	tcp_v6_init_req(req, sk, skb);
 824
 825	if (security_inet_conn_request(sk, skb, req))
 826		return NULL;
 827
 828	return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
 829}
 830
 831struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
 832	.family		=	AF_INET6,
 833	.obj_size	=	sizeof(struct tcp6_request_sock),
 834	.rtx_syn_ack	=	tcp_rtx_synack,
 835	.send_ack	=	tcp_v6_reqsk_send_ack,
 836	.destructor	=	tcp_v6_reqsk_destructor,
 837	.send_reset	=	tcp_v6_send_reset,
 838	.syn_ack_timeout =	tcp_syn_ack_timeout,
 839};
 840
 841const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 842	.mss_clamp	=	IPV6_MIN_MTU - sizeof(struct tcphdr) -
 843				sizeof(struct ipv6hdr),
 844#ifdef CONFIG_TCP_MD5SIG
 845	.req_md5_lookup	=	tcp_v6_md5_lookup,
 846	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
 847#endif
 848#ifdef CONFIG_TCP_AO
 849	.ao_lookup	=	tcp_v6_ao_lookup_rsk,
 850	.ao_calc_key	=	tcp_v6_ao_calc_key_rsk,
 851	.ao_synack_hash =	tcp_v6_ao_synack_hash,
 852#endif
 853#ifdef CONFIG_SYN_COOKIES
 854	.cookie_init_seq =	cookie_v6_init_sequence,
 855#endif
 856	.route_req	=	tcp_v6_route_req,
 857	.init_seq	=	tcp_v6_init_seq,
 858	.init_ts_off	=	tcp_v6_init_ts_off,
 859	.send_synack	=	tcp_v6_send_synack,
 860};
 861
 862static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
 863				 u32 ack, u32 win, u32 tsval, u32 tsecr,
 864				 int oif, int rst, u8 tclass, __be32 label,
 865				 u32 priority, u32 txhash, struct tcp_key *key)
 866{
 867	const struct tcphdr *th = tcp_hdr(skb);
 868	struct tcphdr *t1;
 869	struct sk_buff *buff;
 870	struct flowi6 fl6;
 871	struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
 872	struct sock *ctl_sk = net->ipv6.tcp_sk;
 873	unsigned int tot_len = sizeof(struct tcphdr);
 874	__be32 mrst = 0, *topt;
 875	struct dst_entry *dst;
 876	__u32 mark = 0;
 877
 878	if (tsecr)
 879		tot_len += TCPOLEN_TSTAMP_ALIGNED;
 880	if (tcp_key_is_md5(key))
 
 881		tot_len += TCPOLEN_MD5SIG_ALIGNED;
 882	if (tcp_key_is_ao(key))
 883		tot_len += tcp_ao_len_aligned(key->ao_key);
 884
 885#ifdef CONFIG_MPTCP
 886	if (rst && !tcp_key_is_md5(key)) {
 887		mrst = mptcp_reset_option(skb);
 888
 889		if (mrst)
 890			tot_len += sizeof(__be32);
 891	}
 892#endif
 893
 894	buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
 895	if (!buff)
 896		return;
 897
 898	skb_reserve(buff, MAX_TCP_HEADER);
 899
 900	t1 = skb_push(buff, tot_len);
 901	skb_reset_transport_header(buff);
 902
 903	/* Swap the send and the receive. */
 904	memset(t1, 0, sizeof(*t1));
 905	t1->dest = th->source;
 906	t1->source = th->dest;
 907	t1->doff = tot_len / 4;
 908	t1->seq = htonl(seq);
 909	t1->ack_seq = htonl(ack);
 910	t1->ack = !rst || !th->ack;
 911	t1->rst = rst;
 912	t1->window = htons(win);
 913
 914	topt = (__be32 *)(t1 + 1);
 915
 916	if (tsecr) {
 917		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 918				(TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
 919		*topt++ = htonl(tsval);
 920		*topt++ = htonl(tsecr);
 921	}
 922
 923	if (mrst)
 924		*topt++ = mrst;
 925
 926#ifdef CONFIG_TCP_MD5SIG
 927	if (tcp_key_is_md5(key)) {
 928		*topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
 929				(TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
 930		tcp_v6_md5_hash_hdr((__u8 *)topt, key->md5_key,
 931				    &ipv6_hdr(skb)->saddr,
 932				    &ipv6_hdr(skb)->daddr, t1);
 933	}
 934#endif
 935#ifdef CONFIG_TCP_AO
 936	if (tcp_key_is_ao(key)) {
 937		*topt++ = htonl((TCPOPT_AO << 24) |
 938				(tcp_ao_len(key->ao_key) << 16) |
 939				(key->ao_key->sndid << 8) |
 940				(key->rcv_next));
 941
 942		tcp_ao_hash_hdr(AF_INET6, (char *)topt, key->ao_key,
 943				key->traffic_key,
 944				(union tcp_ao_addr *)&ipv6_hdr(skb)->saddr,
 945				(union tcp_ao_addr *)&ipv6_hdr(skb)->daddr,
 946				t1, key->sne);
 947	}
 948#endif
 949
 950	memset(&fl6, 0, sizeof(fl6));
 951	fl6.daddr = ipv6_hdr(skb)->saddr;
 952	fl6.saddr = ipv6_hdr(skb)->daddr;
 953	fl6.flowlabel = label;
 954
 955	buff->ip_summed = CHECKSUM_PARTIAL;
 956
 957	__tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
 958
 959	fl6.flowi6_proto = IPPROTO_TCP;
 960	if (rt6_need_strict(&fl6.daddr) && !oif)
 961		fl6.flowi6_oif = tcp_v6_iif(skb);
 962	else {
 963		if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
 964			oif = skb->skb_iif;
 965
 966		fl6.flowi6_oif = oif;
 967	}
 968
 969	if (sk) {
 970		if (sk->sk_state == TCP_TIME_WAIT)
 971			mark = inet_twsk(sk)->tw_mark;
 972		else
 973			mark = READ_ONCE(sk->sk_mark);
 974		skb_set_delivery_time(buff, tcp_transmit_time(sk), true);
 975	}
 976	if (txhash) {
 977		/* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */
 978		skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4);
 979	}
 980	fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
 981	fl6.fl6_dport = t1->dest;
 982	fl6.fl6_sport = t1->source;
 983	fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
 984	security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
 985
 986	/* Pass a socket to ip6_dst_lookup either it is for RST
 987	 * Underlying function will use this to retrieve the network
 988	 * namespace
 989	 */
 990	if (sk && sk->sk_state != TCP_TIME_WAIT)
 991		dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/
 992	else
 993		dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL);
 994	if (!IS_ERR(dst)) {
 995		skb_dst_set(buff, dst);
 996		ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
 997			 tclass & ~INET_ECN_MASK, priority);
 998		TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
 999		if (rst)
1000			TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
1001		return;
1002	}
1003
1004	kfree_skb(buff);
1005}
1006
1007static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
1008{
1009	const struct tcphdr *th = tcp_hdr(skb);
1010	struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1011	const __u8 *md5_hash_location = NULL;
1012#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1013	bool allocated_traffic_key = false;
1014#endif
1015	const struct tcp_ao_hdr *aoh;
1016	struct tcp_key key = {};
1017	u32 seq = 0, ack_seq = 0;
1018	__be32 label = 0;
1019	u32 priority = 0;
1020	struct net *net;
1021	u32 txhash = 0;
1022	int oif = 0;
1023#ifdef CONFIG_TCP_MD5SIG
 
1024	unsigned char newhash[16];
1025	int genhash;
1026	struct sock *sk1 = NULL;
1027#endif
 
 
 
 
 
1028
1029	if (th->rst)
1030		return;
1031
1032	/* If sk not NULL, it means we did a successful lookup and incoming
1033	 * route had to be correct. prequeue might have dropped our dst.
1034	 */
1035	if (!sk && !ipv6_unicast_destination(skb))
1036		return;
1037
1038	net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
1039	/* Invalid TCP option size or twice included auth */
1040	if (tcp_parse_auth_options(th, &md5_hash_location, &aoh))
1041		return;
1042#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1043	rcu_read_lock();
1044#endif
1045#ifdef CONFIG_TCP_MD5SIG
 
 
1046	if (sk && sk_fullsock(sk)) {
1047		int l3index;
1048
1049		/* sdif set, means packet ingressed via a device
1050		 * in an L3 domain and inet_iif is set to it.
1051		 */
1052		l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1053		key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
1054		if (key.md5_key)
1055			key.type = TCP_KEY_MD5;
1056	} else if (md5_hash_location) {
1057		int dif = tcp_v6_iif_l3_slave(skb);
1058		int sdif = tcp_v6_sdif(skb);
1059		int l3index;
1060
1061		/*
1062		 * active side is lost. Try to find listening socket through
1063		 * source port, and then find md5 key through listening socket.
1064		 * we are not loose security here:
1065		 * Incoming packet is checked with md5 hash with finding key,
1066		 * no RST generated if md5 hash doesn't match.
1067		 */
1068		sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1069					    NULL, 0, &ipv6h->saddr, th->source,
1070					    &ipv6h->daddr, ntohs(th->source),
1071					    dif, sdif);
1072		if (!sk1)
1073			goto out;
1074
1075		/* sdif set, means packet ingressed via a device
1076		 * in an L3 domain and dif is set to it.
1077		 */
1078		l3index = tcp_v6_sdif(skb) ? dif : 0;
1079
1080		key.md5_key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
1081		if (!key.md5_key)
1082			goto out;
1083		key.type = TCP_KEY_MD5;
1084
1085		genhash = tcp_v6_md5_hash_skb(newhash, key.md5_key, NULL, skb);
1086		if (genhash || memcmp(md5_hash_location, newhash, 16) != 0)
1087			goto out;
1088	}
1089#endif
1090
1091	if (th->ack)
1092		seq = ntohl(th->ack_seq);
1093	else
1094		ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
1095			  (th->doff << 2);
1096
1097#ifdef CONFIG_TCP_AO
1098	if (aoh) {
1099		int l3index;
1100
1101		l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1102		if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, seq,
1103					 &key.ao_key, &key.traffic_key,
1104					 &allocated_traffic_key,
1105					 &key.rcv_next, &key.sne))
1106			goto out;
1107		key.type = TCP_KEY_AO;
1108	}
1109#endif
1110
1111	if (sk) {
1112		oif = sk->sk_bound_dev_if;
1113		if (sk_fullsock(sk)) {
 
 
1114			trace_tcp_send_reset(sk, skb);
1115			if (inet6_test_bit(REPFLOW, sk))
1116				label = ip6_flowlabel(ipv6h);
1117			priority = READ_ONCE(sk->sk_priority);
1118			txhash = sk->sk_txhash;
1119		}
1120		if (sk->sk_state == TCP_TIME_WAIT) {
1121			label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
1122			priority = inet_twsk(sk)->tw_priority;
1123			txhash = inet_twsk(sk)->tw_txhash;
1124		}
1125	} else {
1126		if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
1127			label = ip6_flowlabel(ipv6h);
1128	}
1129
1130	tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, 1,
1131			     ipv6_get_dsfield(ipv6h), label, priority, txhash,
1132			     &key);
1133
1134#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1135out:
1136	if (allocated_traffic_key)
1137		kfree(key.traffic_key);
1138	rcu_read_unlock();
1139#endif
1140}
1141
1142static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
1143			    u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
1144			    struct tcp_key *key, u8 tclass,
1145			    __be32 label, u32 priority, u32 txhash)
1146{
1147	tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, 0,
1148			     tclass, label, priority, txhash, key);
1149}
1150
1151static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
1152{
1153	struct inet_timewait_sock *tw = inet_twsk(sk);
1154	struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
1155	struct tcp_key key = {};
1156#ifdef CONFIG_TCP_AO
1157	struct tcp_ao_info *ao_info;
1158
1159	if (static_branch_unlikely(&tcp_ao_needed.key)) {
1160
1161		/* FIXME: the segment to-be-acked is not verified yet */
1162		ao_info = rcu_dereference(tcptw->ao_info);
1163		if (ao_info) {
1164			const struct tcp_ao_hdr *aoh;
1165
1166			/* Invalid TCP option size or twice included auth */
1167			if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1168				goto out;
1169			if (aoh)
1170				key.ao_key = tcp_ao_established_key(ao_info,
1171						aoh->rnext_keyid, -1);
1172		}
1173	}
1174	if (key.ao_key) {
1175		struct tcp_ao_key *rnext_key;
1176
1177		key.traffic_key = snd_other_key(key.ao_key);
1178		/* rcv_next switches to our rcv_next */
1179		rnext_key = READ_ONCE(ao_info->rnext_key);
1180		key.rcv_next = rnext_key->rcvid;
1181		key.sne = READ_ONCE(ao_info->snd_sne);
1182		key.type = TCP_KEY_AO;
1183#else
1184	if (0) {
1185#endif
1186#ifdef CONFIG_TCP_MD5SIG
1187	} else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1188		key.md5_key = tcp_twsk_md5_key(tcptw);
1189		if (key.md5_key)
1190			key.type = TCP_KEY_MD5;
1191#endif
1192	}
1193
1194	tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
1195			tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
1196			tcp_tw_tsval(tcptw),
1197			tcptw->tw_ts_recent, tw->tw_bound_dev_if, &key,
1198			tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority,
1199			tw->tw_txhash);
1200
1201#ifdef CONFIG_TCP_AO
1202out:
1203#endif
1204	inet_twsk_put(tw);
1205}
1206
1207static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
1208				  struct request_sock *req)
1209{
1210	struct tcp_key key = {};
1211
1212#ifdef CONFIG_TCP_AO
1213	if (static_branch_unlikely(&tcp_ao_needed.key) &&
1214	    tcp_rsk_used_ao(req)) {
1215		const struct in6_addr *addr = &ipv6_hdr(skb)->saddr;
1216		const struct tcp_ao_hdr *aoh;
1217		int l3index;
1218
1219		l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1220		/* Invalid TCP option size or twice included auth */
1221		if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh))
1222			return;
1223		if (!aoh)
1224			return;
1225		key.ao_key = tcp_ao_do_lookup(sk, l3index,
1226					      (union tcp_ao_addr *)addr,
1227					      AF_INET6, aoh->rnext_keyid, -1);
1228		if (unlikely(!key.ao_key)) {
1229			/* Send ACK with any matching MKT for the peer */
1230			key.ao_key = tcp_ao_do_lookup(sk, l3index,
1231						      (union tcp_ao_addr *)addr,
1232						      AF_INET6, -1, -1);
1233			/* Matching key disappeared (user removed the key?)
1234			 * let the handshake timeout.
1235			 */
1236			if (!key.ao_key) {
1237				net_info_ratelimited("TCP-AO key for (%pI6, %d)->(%pI6, %d) suddenly disappeared, won't ACK new connection\n",
1238						     addr,
1239						     ntohs(tcp_hdr(skb)->source),
1240						     &ipv6_hdr(skb)->daddr,
1241						     ntohs(tcp_hdr(skb)->dest));
1242				return;
1243			}
1244		}
1245		key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC);
1246		if (!key.traffic_key)
1247			return;
1248
1249		key.type = TCP_KEY_AO;
1250		key.rcv_next = aoh->keyid;
1251		tcp_v6_ao_calc_key_rsk(key.ao_key, key.traffic_key, req);
1252#else
1253	if (0) {
1254#endif
1255#ifdef CONFIG_TCP_MD5SIG
1256	} else if (static_branch_unlikely(&tcp_md5_needed.key)) {
1257		int l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
1258
1259		key.md5_key = tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr,
1260						   l3index);
1261		if (key.md5_key)
1262			key.type = TCP_KEY_MD5;
1263#endif
1264	}
1265
1266	/* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
1267	 * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
1268	 */
1269	/* RFC 7323 2.3
1270	 * The window field (SEG.WND) of every outgoing segment, with the
1271	 * exception of <SYN> segments, MUST be right-shifted by
1272	 * Rcv.Wind.Shift bits:
1273	 */
1274	tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
1275			tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
1276			tcp_rsk(req)->rcv_nxt,
1277			req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
1278			tcp_rsk_tsval(tcp_rsk(req)),
1279			READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,
1280			&key, ipv6_get_dsfield(ipv6_hdr(skb)), 0,
1281			READ_ONCE(sk->sk_priority),
1282			READ_ONCE(tcp_rsk(req)->txhash));
1283	if (tcp_key_is_ao(&key))
1284		kfree(key.traffic_key);
1285}
1286
1287
1288static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
1289{
1290#ifdef CONFIG_SYN_COOKIES
1291	const struct tcphdr *th = tcp_hdr(skb);
1292
1293	if (!th->syn)
1294		sk = cookie_v6_check(sk, skb);
1295#endif
1296	return sk;
1297}
1298
1299u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
1300			 struct tcphdr *th, u32 *cookie)
1301{
1302	u16 mss = 0;
1303#ifdef CONFIG_SYN_COOKIES
1304	mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
1305				    &tcp_request_sock_ipv6_ops, sk, th);
1306	if (mss) {
1307		*cookie = __cookie_v6_init_sequence(iph, th, &mss);
1308		tcp_synq_overflow(sk);
1309	}
1310#endif
1311	return mss;
1312}
1313
1314static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
1315{
1316	if (skb->protocol == htons(ETH_P_IP))
1317		return tcp_v4_conn_request(sk, skb);
1318
1319	if (!ipv6_unicast_destination(skb))
1320		goto drop;
1321
1322	if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
1323		__IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
1324		return 0;
1325	}
1326
1327	return tcp_conn_request(&tcp6_request_sock_ops,
1328				&tcp_request_sock_ipv6_ops, sk, skb);
1329
1330drop:
1331	tcp_listendrop(sk);
1332	return 0; /* don't send reset */
1333}
1334
1335static void tcp_v6_restore_cb(struct sk_buff *skb)
1336{
1337	/* We need to move header back to the beginning if xfrm6_policy_check()
1338	 * and tcp_v6_fill_cb() are going to be called again.
1339	 * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
1340	 */
1341	memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
1342		sizeof(struct inet6_skb_parm));
1343}
1344
1345static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
1346					 struct request_sock *req,
1347					 struct dst_entry *dst,
1348					 struct request_sock *req_unhash,
1349					 bool *own_req)
1350{
1351	struct inet_request_sock *ireq;
1352	struct ipv6_pinfo *newnp;
1353	const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1354	struct ipv6_txoptions *opt;
1355	struct inet_sock *newinet;
1356	bool found_dup_sk = false;
1357	struct tcp_sock *newtp;
1358	struct sock *newsk;
1359#ifdef CONFIG_TCP_MD5SIG
1360	struct tcp_md5sig_key *key;
1361	int l3index;
1362#endif
1363	struct flowi6 fl6;
1364
1365	if (skb->protocol == htons(ETH_P_IP)) {
1366		/*
1367		 *	v6 mapped
1368		 */
1369
1370		newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
1371					     req_unhash, own_req);
1372
1373		if (!newsk)
1374			return NULL;
1375
1376		inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1377
1378		newnp = tcp_inet6_sk(newsk);
1379		newtp = tcp_sk(newsk);
1380
1381		memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1382
1383		newnp->saddr = newsk->sk_v6_rcv_saddr;
1384
1385		inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
1386		if (sk_is_mptcp(newsk))
1387			mptcpv6_handle_mapped(newsk, true);
1388		newsk->sk_backlog_rcv = tcp_v4_do_rcv;
1389#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
1390		newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
1391#endif
1392
1393		newnp->ipv6_mc_list = NULL;
1394		newnp->ipv6_ac_list = NULL;
1395		newnp->ipv6_fl_list = NULL;
1396		newnp->pktoptions  = NULL;
1397		newnp->opt	   = NULL;
1398		newnp->mcast_oif   = inet_iif(skb);
1399		newnp->mcast_hops  = ip_hdr(skb)->ttl;
1400		newnp->rcv_flowinfo = 0;
1401		if (inet6_test_bit(REPFLOW, sk))
1402			newnp->flow_label = 0;
1403
1404		/*
1405		 * No need to charge this sock to the relevant IPv6 refcnt debug socks count
1406		 * here, tcp_create_openreq_child now does this for us, see the comment in
1407		 * that function for the gory details. -acme
1408		 */
1409
1410		/* It is tricky place. Until this moment IPv4 tcp
1411		   worked with IPv6 icsk.icsk_af_ops.
1412		   Sync it now.
1413		 */
1414		tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
1415
1416		return newsk;
1417	}
1418
1419	ireq = inet_rsk(req);
1420
1421	if (sk_acceptq_is_full(sk))
1422		goto out_overflow;
1423
1424	if (!dst) {
1425		dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
1426		if (!dst)
1427			goto out;
1428	}
1429
1430	newsk = tcp_create_openreq_child(sk, req, skb);
1431	if (!newsk)
1432		goto out_nonewsk;
1433
1434	/*
1435	 * No need to charge this sock to the relevant IPv6 refcnt debug socks
1436	 * count here, tcp_create_openreq_child now does this for us, see the
1437	 * comment in that function for the gory details. -acme
1438	 */
1439
1440	newsk->sk_gso_type = SKB_GSO_TCPV6;
1441	ip6_dst_store(newsk, dst, NULL, NULL);
1442	inet6_sk_rx_dst_set(newsk, skb);
1443
1444	inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
1445
1446	newtp = tcp_sk(newsk);
1447	newinet = inet_sk(newsk);
1448	newnp = tcp_inet6_sk(newsk);
1449
1450	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
1451
1452	newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
1453	newnp->saddr = ireq->ir_v6_loc_addr;
1454	newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
1455	newsk->sk_bound_dev_if = ireq->ir_iif;
1456
1457	/* Now IPv6 options...
1458
1459	   First: no IPv4 options.
1460	 */
1461	newinet->inet_opt = NULL;
1462	newnp->ipv6_mc_list = NULL;
1463	newnp->ipv6_ac_list = NULL;
1464	newnp->ipv6_fl_list = NULL;
1465
1466	/* Clone RX bits */
1467	newnp->rxopt.all = np->rxopt.all;
1468
1469	newnp->pktoptions = NULL;
1470	newnp->opt	  = NULL;
1471	newnp->mcast_oif  = tcp_v6_iif(skb);
1472	newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
1473	newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
1474	if (inet6_test_bit(REPFLOW, sk))
1475		newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
1476
1477	/* Set ToS of the new socket based upon the value of incoming SYN.
1478	 * ECT bits are set later in tcp_init_transfer().
1479	 */
1480	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
1481		newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
1482
1483	/* Clone native IPv6 options from listening socket (if any)
1484
1485	   Yes, keeping reference count would be much more clever,
1486	   but we make one more one thing there: reattach optmem
1487	   to newsk.
1488	 */
1489	opt = ireq->ipv6_opt;
1490	if (!opt)
1491		opt = rcu_dereference(np->opt);
1492	if (opt) {
1493		opt = ipv6_dup_options(newsk, opt);
1494		RCU_INIT_POINTER(newnp->opt, opt);
1495	}
1496	inet_csk(newsk)->icsk_ext_hdr_len = 0;
1497	if (opt)
1498		inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
1499						    opt->opt_flen;
1500
1501	tcp_ca_openreq_child(newsk, dst);
1502
1503	tcp_sync_mss(newsk, dst_mtu(dst));
1504	newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
1505
1506	tcp_initialize_rcv_mss(newsk);
1507
1508	newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
1509	newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
1510
1511#ifdef CONFIG_TCP_MD5SIG
1512	l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
1513
1514	if (!tcp_rsk_used_ao(req)) {
1515		/* Copy over the MD5 key from the original socket */
1516		key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
1517		if (key) {
1518			const union tcp_md5_addr *addr;
1519
1520			addr = (union tcp_md5_addr *)&newsk->sk_v6_daddr;
1521			if (tcp_md5_key_copy(newsk, addr, AF_INET6, 128, l3index, key)) {
1522				inet_csk_prepare_forced_close(newsk);
1523				tcp_done(newsk);
1524				goto out;
1525			}
1526		}
1527	}
1528#endif
1529#ifdef CONFIG_TCP_AO
1530	/* Copy over tcp_ao_info if any */
1531	if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET6))
1532		goto out; /* OOM */
1533#endif
1534
1535	if (__inet_inherit_port(sk, newsk) < 0) {
1536		inet_csk_prepare_forced_close(newsk);
1537		tcp_done(newsk);
1538		goto out;
1539	}
1540	*own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
1541				       &found_dup_sk);
1542	if (*own_req) {
1543		tcp_move_syn(newtp, req);
1544
1545		/* Clone pktoptions received with SYN, if we own the req */
1546		if (ireq->pktopts) {
1547			newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
1548			consume_skb(ireq->pktopts);
1549			ireq->pktopts = NULL;
1550			if (newnp->pktoptions)
1551				tcp_v6_restore_cb(newnp->pktoptions);
1552		}
1553	} else {
1554		if (!req_unhash && found_dup_sk) {
1555			/* This code path should only be executed in the
1556			 * syncookie case only
1557			 */
1558			bh_unlock_sock(newsk);
1559			sock_put(newsk);
1560			newsk = NULL;
1561		}
1562	}
1563
1564	return newsk;
1565
1566out_overflow:
1567	__NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
1568out_nonewsk:
1569	dst_release(dst);
1570out:
1571	tcp_listendrop(sk);
1572	return NULL;
1573}
1574
1575INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
1576							   u32));
1577/* The socket must have it's spinlock held when we get
1578 * here, unless it is a TCP_LISTEN socket.
1579 *
1580 * We have a potential double-lock case here, so even when
1581 * doing backlog processing we use the BH locking scheme.
1582 * This is because we cannot sleep with the original spinlock
1583 * held.
1584 */
1585INDIRECT_CALLABLE_SCOPE
1586int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
1587{
1588	struct ipv6_pinfo *np = tcp_inet6_sk(sk);
1589	struct sk_buff *opt_skb = NULL;
1590	enum skb_drop_reason reason;
1591	struct tcp_sock *tp;
1592
1593	/* Imagine: socket is IPv6. IPv4 packet arrives,
1594	   goes to IPv4 receive handler and backlogged.
1595	   From backlog it always goes here. Kerboom...
1596	   Fortunately, tcp_rcv_established and rcv_established
1597	   handle them correctly, but it is not case with
1598	   tcp_v6_hnd_req and tcp_v6_send_reset().   --ANK
1599	 */
1600
1601	if (skb->protocol == htons(ETH_P_IP))
1602		return tcp_v4_do_rcv(sk, skb);
1603
1604	/*
1605	 *	socket locking is here for SMP purposes as backlog rcv
1606	 *	is currently called with bh processing disabled.
1607	 */
1608
1609	/* Do Stevens' IPV6_PKTOPTIONS.
1610
1611	   Yes, guys, it is the only place in our code, where we
1612	   may make it not affecting IPv4.
1613	   The rest of code is protocol independent,
1614	   and I do not like idea to uglify IPv4.
1615
1616	   Actually, all the idea behind IPV6_PKTOPTIONS
1617	   looks not very well thought. For now we latch
1618	   options, received in the last packet, enqueued
1619	   by tcp. Feel free to propose better solution.
1620					       --ANK (980728)
1621	 */
1622	if (np->rxopt.all)
1623		opt_skb = skb_clone_and_charge_r(skb, sk);
1624
 
1625	if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
1626		struct dst_entry *dst;
1627
1628		dst = rcu_dereference_protected(sk->sk_rx_dst,
1629						lockdep_sock_is_held(sk));
1630
1631		sock_rps_save_rxhash(sk, skb);
1632		sk_mark_napi_id(sk, skb);
1633		if (dst) {
1634			if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
1635			    INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
1636					    dst, sk->sk_rx_dst_cookie) == NULL) {
1637				RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
1638				dst_release(dst);
1639			}
1640		}
1641
1642		tcp_rcv_established(sk, skb);
1643		if (opt_skb)
1644			goto ipv6_pktoptions;
1645		return 0;
1646	}
1647
1648	if (tcp_checksum_complete(skb))
1649		goto csum_err;
1650
1651	if (sk->sk_state == TCP_LISTEN) {
1652		struct sock *nsk = tcp_v6_cookie_check(sk, skb);
1653
 
 
 
1654		if (nsk != sk) {
1655			if (nsk) {
1656				reason = tcp_child_process(sk, nsk, skb);
1657				if (reason)
1658					goto reset;
1659			}
1660			if (opt_skb)
1661				__kfree_skb(opt_skb);
1662			return 0;
1663		}
1664	} else
1665		sock_rps_save_rxhash(sk, skb);
1666
1667	reason = tcp_rcv_state_process(sk, skb);
1668	if (reason)
1669		goto reset;
1670	if (opt_skb)
1671		goto ipv6_pktoptions;
1672	return 0;
1673
1674reset:
1675	tcp_v6_send_reset(sk, skb);
1676discard:
1677	if (opt_skb)
1678		__kfree_skb(opt_skb);
1679	kfree_skb_reason(skb, reason);
1680	return 0;
1681csum_err:
1682	reason = SKB_DROP_REASON_TCP_CSUM;
1683	trace_tcp_bad_csum(skb);
1684	TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
1685	TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
1686	goto discard;
1687
1688
1689ipv6_pktoptions:
1690	/* Do you ask, what is it?
1691
1692	   1. skb was enqueued by tcp.
1693	   2. skb is added to tail of read queue, rather than out of order.
1694	   3. socket is not in passive state.
1695	   4. Finally, it really contains options, which user wants to receive.
1696	 */
1697	tp = tcp_sk(sk);
1698	if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
1699	    !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
1700		if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
1701			WRITE_ONCE(np->mcast_oif, tcp_v6_iif(opt_skb));
1702		if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
1703			WRITE_ONCE(np->mcast_hops,
1704				   ipv6_hdr(opt_skb)->hop_limit);
1705		if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
1706			np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
1707		if (inet6_test_bit(REPFLOW, sk))
1708			np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
1709		if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
1710			tcp_v6_restore_cb(opt_skb);
1711			opt_skb = xchg(&np->pktoptions, opt_skb);
1712		} else {
1713			__kfree_skb(opt_skb);
1714			opt_skb = xchg(&np->pktoptions, NULL);
1715		}
1716	}
1717
1718	consume_skb(opt_skb);
1719	return 0;
1720}
1721
1722static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
1723			   const struct tcphdr *th)
1724{
1725	/* This is tricky: we move IP6CB at its correct location into
1726	 * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
1727	 * _decode_session6() uses IP6CB().
1728	 * barrier() makes sure compiler won't play aliasing games.
1729	 */
1730	memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
1731		sizeof(struct inet6_skb_parm));
1732	barrier();
1733
1734	TCP_SKB_CB(skb)->seq = ntohl(th->seq);
1735	TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
1736				    skb->len - th->doff*4);
1737	TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
1738	TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
1739	TCP_SKB_CB(skb)->tcp_tw_isn = 0;
1740	TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
1741	TCP_SKB_CB(skb)->sacked = 0;
1742	TCP_SKB_CB(skb)->has_rxtstamp =
1743			skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
1744}
1745
1746INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
1747{
1748	enum skb_drop_reason drop_reason;
1749	int sdif = inet6_sdif(skb);
1750	int dif = inet6_iif(skb);
1751	const struct tcphdr *th;
1752	const struct ipv6hdr *hdr;
1753	bool refcounted;
1754	struct sock *sk;
1755	int ret;
1756	struct net *net = dev_net(skb->dev);
1757
1758	drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
1759	if (skb->pkt_type != PACKET_HOST)
1760		goto discard_it;
1761
1762	/*
1763	 *	Count it even if it's bad.
1764	 */
1765	__TCP_INC_STATS(net, TCP_MIB_INSEGS);
1766
1767	if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
1768		goto discard_it;
1769
1770	th = (const struct tcphdr *)skb->data;
1771
1772	if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
1773		drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
1774		goto bad_packet;
1775	}
1776	if (!pskb_may_pull(skb, th->doff*4))
1777		goto discard_it;
1778
1779	if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
1780		goto csum_error;
1781
1782	th = (const struct tcphdr *)skb->data;
1783	hdr = ipv6_hdr(skb);
1784
1785lookup:
1786	sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
1787				th->source, th->dest, inet6_iif(skb), sdif,
1788				&refcounted);
1789	if (!sk)
1790		goto no_tcp_socket;
1791
1792process:
1793	if (sk->sk_state == TCP_TIME_WAIT)
1794		goto do_time_wait;
1795
1796	if (sk->sk_state == TCP_NEW_SYN_RECV) {
1797		struct request_sock *req = inet_reqsk(sk);
1798		bool req_stolen = false;
1799		struct sock *nsk;
1800
1801		sk = req->rsk_listener;
1802		if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
1803			drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1804		else
1805			drop_reason = tcp_inbound_hash(sk, req, skb,
1806						       &hdr->saddr, &hdr->daddr,
1807						       AF_INET6, dif, sdif);
1808		if (drop_reason) {
1809			sk_drops_add(sk, skb);
1810			reqsk_put(req);
1811			goto discard_it;
1812		}
1813		if (tcp_checksum_complete(skb)) {
1814			reqsk_put(req);
1815			goto csum_error;
1816		}
1817		if (unlikely(sk->sk_state != TCP_LISTEN)) {
1818			nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
1819			if (!nsk) {
1820				inet_csk_reqsk_queue_drop_and_put(sk, req);
1821				goto lookup;
1822			}
1823			sk = nsk;
1824			/* reuseport_migrate_sock() has already held one sk_refcnt
1825			 * before returning.
1826			 */
1827		} else {
1828			sock_hold(sk);
1829		}
1830		refcounted = true;
1831		nsk = NULL;
1832		if (!tcp_filter(sk, skb)) {
1833			th = (const struct tcphdr *)skb->data;
1834			hdr = ipv6_hdr(skb);
1835			tcp_v6_fill_cb(skb, hdr, th);
1836			nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
1837		} else {
1838			drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1839		}
1840		if (!nsk) {
1841			reqsk_put(req);
1842			if (req_stolen) {
1843				/* Another cpu got exclusive access to req
1844				 * and created a full blown socket.
1845				 * Try to feed this packet to this socket
1846				 * instead of discarding it.
1847				 */
1848				tcp_v6_restore_cb(skb);
1849				sock_put(sk);
1850				goto lookup;
1851			}
1852			goto discard_and_relse;
1853		}
1854		nf_reset_ct(skb);
1855		if (nsk == sk) {
1856			reqsk_put(req);
1857			tcp_v6_restore_cb(skb);
 
 
 
1858		} else {
1859			drop_reason = tcp_child_process(sk, nsk, skb);
1860			if (drop_reason) {
1861				tcp_v6_send_reset(nsk, skb);
1862				goto discard_and_relse;
1863			}
1864			sock_put(sk);
1865			return 0;
1866		}
1867	}
1868
1869	if (static_branch_unlikely(&ip6_min_hopcount)) {
1870		/* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
1871		if (unlikely(hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount))) {
1872			__NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
1873			drop_reason = SKB_DROP_REASON_TCP_MINTTL;
1874			goto discard_and_relse;
1875		}
1876	}
1877
1878	if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
1879		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1880		goto discard_and_relse;
1881	}
1882
1883	drop_reason = tcp_inbound_hash(sk, NULL, skb, &hdr->saddr, &hdr->daddr,
1884				       AF_INET6, dif, sdif);
1885	if (drop_reason)
1886		goto discard_and_relse;
1887
1888	nf_reset_ct(skb);
1889
1890	if (tcp_filter(sk, skb)) {
1891		drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
1892		goto discard_and_relse;
1893	}
1894	th = (const struct tcphdr *)skb->data;
1895	hdr = ipv6_hdr(skb);
1896	tcp_v6_fill_cb(skb, hdr, th);
1897
1898	skb->dev = NULL;
1899
1900	if (sk->sk_state == TCP_LISTEN) {
1901		ret = tcp_v6_do_rcv(sk, skb);
1902		goto put_and_return;
1903	}
1904
1905	sk_incoming_cpu_update(sk);
1906
1907	bh_lock_sock_nested(sk);
1908	tcp_segs_in(tcp_sk(sk), skb);
1909	ret = 0;
1910	if (!sock_owned_by_user(sk)) {
1911		ret = tcp_v6_do_rcv(sk, skb);
1912	} else {
1913		if (tcp_add_backlog(sk, skb, &drop_reason))
1914			goto discard_and_relse;
1915	}
1916	bh_unlock_sock(sk);
1917put_and_return:
1918	if (refcounted)
1919		sock_put(sk);
1920	return ret ? -1 : 0;
1921
1922no_tcp_socket:
1923	drop_reason = SKB_DROP_REASON_NO_SOCKET;
1924	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1925		goto discard_it;
1926
1927	tcp_v6_fill_cb(skb, hdr, th);
1928
1929	if (tcp_checksum_complete(skb)) {
1930csum_error:
1931		drop_reason = SKB_DROP_REASON_TCP_CSUM;
1932		trace_tcp_bad_csum(skb);
1933		__TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
1934bad_packet:
1935		__TCP_INC_STATS(net, TCP_MIB_INERRS);
1936	} else {
1937		tcp_v6_send_reset(NULL, skb);
1938	}
1939
1940discard_it:
1941	SKB_DR_OR(drop_reason, NOT_SPECIFIED);
1942	kfree_skb_reason(skb, drop_reason);
1943	return 0;
1944
1945discard_and_relse:
1946	sk_drops_add(sk, skb);
1947	if (refcounted)
1948		sock_put(sk);
1949	goto discard_it;
1950
1951do_time_wait:
1952	if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1953		drop_reason = SKB_DROP_REASON_XFRM_POLICY;
1954		inet_twsk_put(inet_twsk(sk));
1955		goto discard_it;
1956	}
1957
1958	tcp_v6_fill_cb(skb, hdr, th);
1959
1960	if (tcp_checksum_complete(skb)) {
1961		inet_twsk_put(inet_twsk(sk));
1962		goto csum_error;
1963	}
1964
1965	switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
1966	case TCP_TW_SYN:
1967	{
1968		struct sock *sk2;
1969
1970		sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
1971					    skb, __tcp_hdrlen(th),
1972					    &ipv6_hdr(skb)->saddr, th->source,
1973					    &ipv6_hdr(skb)->daddr,
1974					    ntohs(th->dest),
1975					    tcp_v6_iif_l3_slave(skb),
1976					    sdif);
1977		if (sk2) {
1978			struct inet_timewait_sock *tw = inet_twsk(sk);
1979			inet_twsk_deschedule_put(tw);
1980			sk = sk2;
1981			tcp_v6_restore_cb(skb);
1982			refcounted = false;
1983			goto process;
1984		}
1985	}
1986		/* to ACK */
1987		fallthrough;
1988	case TCP_TW_ACK:
1989		tcp_v6_timewait_ack(sk, skb);
1990		break;
1991	case TCP_TW_RST:
1992		tcp_v6_send_reset(sk, skb);
1993		inet_twsk_deschedule_put(inet_twsk(sk));
1994		goto discard_it;
1995	case TCP_TW_SUCCESS:
1996		;
1997	}
1998	goto discard_it;
1999}
2000
2001void tcp_v6_early_demux(struct sk_buff *skb)
2002{
2003	struct net *net = dev_net(skb->dev);
2004	const struct ipv6hdr *hdr;
2005	const struct tcphdr *th;
2006	struct sock *sk;
2007
2008	if (skb->pkt_type != PACKET_HOST)
2009		return;
2010
2011	if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
2012		return;
2013
2014	hdr = ipv6_hdr(skb);
2015	th = tcp_hdr(skb);
2016
2017	if (th->doff < sizeof(struct tcphdr) / 4)
2018		return;
2019
2020	/* Note : We use inet6_iif() here, not tcp_v6_iif() */
2021	sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
2022					&hdr->saddr, th->source,
2023					&hdr->daddr, ntohs(th->dest),
2024					inet6_iif(skb), inet6_sdif(skb));
2025	if (sk) {
2026		skb->sk = sk;
2027		skb->destructor = sock_edemux;
2028		if (sk_fullsock(sk)) {
2029			struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
2030
2031			if (dst)
2032				dst = dst_check(dst, sk->sk_rx_dst_cookie);
2033			if (dst &&
2034			    sk->sk_rx_dst_ifindex == skb->skb_iif)
2035				skb_dst_set_noref(skb, dst);
2036		}
2037	}
2038}
2039
2040static struct timewait_sock_ops tcp6_timewait_sock_ops = {
2041	.twsk_obj_size	= sizeof(struct tcp6_timewait_sock),
2042	.twsk_unique	= tcp_twsk_unique,
2043	.twsk_destructor = tcp_twsk_destructor,
2044};
2045
2046INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
2047{
2048	__tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
2049}
2050
2051const struct inet_connection_sock_af_ops ipv6_specific = {
2052	.queue_xmit	   = inet6_csk_xmit,
2053	.send_check	   = tcp_v6_send_check,
2054	.rebuild_header	   = inet6_sk_rebuild_header,
2055	.sk_rx_dst_set	   = inet6_sk_rx_dst_set,
2056	.conn_request	   = tcp_v6_conn_request,
2057	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
2058	.net_header_len	   = sizeof(struct ipv6hdr),
 
2059	.setsockopt	   = ipv6_setsockopt,
2060	.getsockopt	   = ipv6_getsockopt,
2061	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
2062	.sockaddr_len	   = sizeof(struct sockaddr_in6),
2063	.mtu_reduced	   = tcp_v6_mtu_reduced,
2064};
2065
2066#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2067static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
2068#ifdef CONFIG_TCP_MD5SIG
 
2069	.md5_lookup	=	tcp_v6_md5_lookup,
2070	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
2071	.md5_parse	=	tcp_v6_parse_md5_keys,
2072#endif
2073#ifdef CONFIG_TCP_AO
2074	.ao_lookup	=	tcp_v6_ao_lookup,
2075	.calc_ao_hash	=	tcp_v6_ao_hash_skb,
2076	.ao_parse	=	tcp_v6_parse_ao,
2077	.ao_calc_key_sk	=	tcp_v6_ao_calc_key_sk,
2078#endif
2079};
2080#endif
2081
2082/*
2083 *	TCP over IPv4 via INET6 API
2084 */
2085static const struct inet_connection_sock_af_ops ipv6_mapped = {
2086	.queue_xmit	   = ip_queue_xmit,
2087	.send_check	   = tcp_v4_send_check,
2088	.rebuild_header	   = inet_sk_rebuild_header,
2089	.sk_rx_dst_set	   = inet_sk_rx_dst_set,
2090	.conn_request	   = tcp_v6_conn_request,
2091	.syn_recv_sock	   = tcp_v6_syn_recv_sock,
2092	.net_header_len	   = sizeof(struct iphdr),
2093	.setsockopt	   = ipv6_setsockopt,
2094	.getsockopt	   = ipv6_getsockopt,
2095	.addr2sockaddr	   = inet6_csk_addr2sockaddr,
2096	.sockaddr_len	   = sizeof(struct sockaddr_in6),
2097	.mtu_reduced	   = tcp_v4_mtu_reduced,
2098};
2099
2100#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2101static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
2102#ifdef CONFIG_TCP_MD5SIG
 
2103	.md5_lookup	=	tcp_v4_md5_lookup,
2104	.calc_md5_hash	=	tcp_v4_md5_hash_skb,
2105	.md5_parse	=	tcp_v6_parse_md5_keys,
2106#endif
2107#ifdef CONFIG_TCP_AO
2108	.ao_lookup	=	tcp_v6_ao_lookup,
2109	.calc_ao_hash	=	tcp_v4_ao_hash_skb,
2110	.ao_parse	=	tcp_v6_parse_ao,
2111	.ao_calc_key_sk	=	tcp_v4_ao_calc_key_sk,
2112#endif
2113};
2114#endif
2115
2116/* NOTE: A lot of things set to zero explicitly by call to
2117 *       sk_alloc() so need not be done here.
2118 */
2119static int tcp_v6_init_sock(struct sock *sk)
2120{
2121	struct inet_connection_sock *icsk = inet_csk(sk);
2122
2123	tcp_init_sock(sk);
2124
2125	icsk->icsk_af_ops = &ipv6_specific;
2126
2127#if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO)
2128	tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
2129#endif
2130
2131	return 0;
2132}
2133
2134#ifdef CONFIG_PROC_FS
2135/* Proc filesystem TCPv6 sock list dumping. */
2136static void get_openreq6(struct seq_file *seq,
2137			 const struct request_sock *req, int i)
2138{
2139	long ttd = req->rsk_timer.expires - jiffies;
2140	const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
2141	const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
2142
2143	if (ttd < 0)
2144		ttd = 0;
2145
2146	seq_printf(seq,
2147		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2148		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
2149		   i,
2150		   src->s6_addr32[0], src->s6_addr32[1],
2151		   src->s6_addr32[2], src->s6_addr32[3],
2152		   inet_rsk(req)->ir_num,
2153		   dest->s6_addr32[0], dest->s6_addr32[1],
2154		   dest->s6_addr32[2], dest->s6_addr32[3],
2155		   ntohs(inet_rsk(req)->ir_rmt_port),
2156		   TCP_SYN_RECV,
2157		   0, 0, /* could print option size, but that is af dependent. */
2158		   1,   /* timers active (only the expire timer) */
2159		   jiffies_to_clock_t(ttd),
2160		   req->num_timeout,
2161		   from_kuid_munged(seq_user_ns(seq),
2162				    sock_i_uid(req->rsk_listener)),
2163		   0,  /* non standard timer */
2164		   0, /* open_requests have no inode */
2165		   0, req);
2166}
2167
2168static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
2169{
2170	const struct in6_addr *dest, *src;
2171	__u16 destp, srcp;
2172	int timer_active;
2173	unsigned long timer_expires;
2174	const struct inet_sock *inet = inet_sk(sp);
2175	const struct tcp_sock *tp = tcp_sk(sp);
2176	const struct inet_connection_sock *icsk = inet_csk(sp);
2177	const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
2178	int rx_queue;
2179	int state;
2180
2181	dest  = &sp->sk_v6_daddr;
2182	src   = &sp->sk_v6_rcv_saddr;
2183	destp = ntohs(inet->inet_dport);
2184	srcp  = ntohs(inet->inet_sport);
2185
2186	if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
2187	    icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
2188	    icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
2189		timer_active	= 1;
2190		timer_expires	= icsk->icsk_timeout;
2191	} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
2192		timer_active	= 4;
2193		timer_expires	= icsk->icsk_timeout;
2194	} else if (timer_pending(&sp->sk_timer)) {
2195		timer_active	= 2;
2196		timer_expires	= sp->sk_timer.expires;
2197	} else {
2198		timer_active	= 0;
2199		timer_expires = jiffies;
2200	}
2201
2202	state = inet_sk_state_load(sp);
2203	if (state == TCP_LISTEN)
2204		rx_queue = READ_ONCE(sp->sk_ack_backlog);
2205	else
2206		/* Because we don't lock the socket,
2207		 * we might find a transient negative value.
2208		 */
2209		rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
2210				      READ_ONCE(tp->copied_seq), 0);
2211
2212	seq_printf(seq,
2213		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2214		   "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
2215		   i,
2216		   src->s6_addr32[0], src->s6_addr32[1],
2217		   src->s6_addr32[2], src->s6_addr32[3], srcp,
2218		   dest->s6_addr32[0], dest->s6_addr32[1],
2219		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
2220		   state,
2221		   READ_ONCE(tp->write_seq) - tp->snd_una,
2222		   rx_queue,
2223		   timer_active,
2224		   jiffies_delta_to_clock_t(timer_expires - jiffies),
2225		   icsk->icsk_retransmits,
2226		   from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
2227		   icsk->icsk_probes_out,
2228		   sock_i_ino(sp),
2229		   refcount_read(&sp->sk_refcnt), sp,
2230		   jiffies_to_clock_t(icsk->icsk_rto),
2231		   jiffies_to_clock_t(icsk->icsk_ack.ato),
2232		   (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
2233		   tcp_snd_cwnd(tp),
2234		   state == TCP_LISTEN ?
2235			fastopenq->max_qlen :
2236			(tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
2237		   );
2238}
2239
2240static void get_timewait6_sock(struct seq_file *seq,
2241			       struct inet_timewait_sock *tw, int i)
2242{
2243	long delta = tw->tw_timer.expires - jiffies;
2244	const struct in6_addr *dest, *src;
2245	__u16 destp, srcp;
2246
2247	dest = &tw->tw_v6_daddr;
2248	src  = &tw->tw_v6_rcv_saddr;
2249	destp = ntohs(tw->tw_dport);
2250	srcp  = ntohs(tw->tw_sport);
2251
2252	seq_printf(seq,
2253		   "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
2254		   "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
2255		   i,
2256		   src->s6_addr32[0], src->s6_addr32[1],
2257		   src->s6_addr32[2], src->s6_addr32[3], srcp,
2258		   dest->s6_addr32[0], dest->s6_addr32[1],
2259		   dest->s6_addr32[2], dest->s6_addr32[3], destp,
2260		   tw->tw_substate, 0, 0,
2261		   3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
2262		   refcount_read(&tw->tw_refcnt), tw);
2263}
2264
2265static int tcp6_seq_show(struct seq_file *seq, void *v)
2266{
2267	struct tcp_iter_state *st;
2268	struct sock *sk = v;
2269
2270	if (v == SEQ_START_TOKEN) {
2271		seq_puts(seq,
2272			 "  sl  "
2273			 "local_address                         "
2274			 "remote_address                        "
2275			 "st tx_queue rx_queue tr tm->when retrnsmt"
2276			 "   uid  timeout inode\n");
2277		goto out;
2278	}
2279	st = seq->private;
2280
2281	if (sk->sk_state == TCP_TIME_WAIT)
2282		get_timewait6_sock(seq, v, st->num);
2283	else if (sk->sk_state == TCP_NEW_SYN_RECV)
2284		get_openreq6(seq, v, st->num);
2285	else
2286		get_tcp6_sock(seq, v, st->num);
2287out:
2288	return 0;
2289}
2290
2291static const struct seq_operations tcp6_seq_ops = {
2292	.show		= tcp6_seq_show,
2293	.start		= tcp_seq_start,
2294	.next		= tcp_seq_next,
2295	.stop		= tcp_seq_stop,
2296};
2297
2298static struct tcp_seq_afinfo tcp6_seq_afinfo = {
2299	.family		= AF_INET6,
2300};
2301
2302int __net_init tcp6_proc_init(struct net *net)
2303{
2304	if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
2305			sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
2306		return -ENOMEM;
2307	return 0;
2308}
2309
2310void tcp6_proc_exit(struct net *net)
2311{
2312	remove_proc_entry("tcp6", net->proc_net);
2313}
2314#endif
2315
2316struct proto tcpv6_prot = {
2317	.name			= "TCPv6",
2318	.owner			= THIS_MODULE,
2319	.close			= tcp_close,
2320	.pre_connect		= tcp_v6_pre_connect,
2321	.connect		= tcp_v6_connect,
2322	.disconnect		= tcp_disconnect,
2323	.accept			= inet_csk_accept,
2324	.ioctl			= tcp_ioctl,
2325	.init			= tcp_v6_init_sock,
2326	.destroy		= tcp_v4_destroy_sock,
2327	.shutdown		= tcp_shutdown,
2328	.setsockopt		= tcp_setsockopt,
2329	.getsockopt		= tcp_getsockopt,
2330	.bpf_bypass_getsockopt	= tcp_bpf_bypass_getsockopt,
2331	.keepalive		= tcp_set_keepalive,
2332	.recvmsg		= tcp_recvmsg,
2333	.sendmsg		= tcp_sendmsg,
2334	.splice_eof		= tcp_splice_eof,
2335	.backlog_rcv		= tcp_v6_do_rcv,
2336	.release_cb		= tcp_release_cb,
2337	.hash			= inet6_hash,
2338	.unhash			= inet_unhash,
2339	.get_port		= inet_csk_get_port,
2340	.put_port		= inet_put_port,
2341#ifdef CONFIG_BPF_SYSCALL
2342	.psock_update_sk_prot	= tcp_bpf_update_proto,
2343#endif
2344	.enter_memory_pressure	= tcp_enter_memory_pressure,
2345	.leave_memory_pressure	= tcp_leave_memory_pressure,
2346	.stream_memory_free	= tcp_stream_memory_free,
2347	.sockets_allocated	= &tcp_sockets_allocated,
2348
2349	.memory_allocated	= &tcp_memory_allocated,
2350	.per_cpu_fw_alloc	= &tcp_memory_per_cpu_fw_alloc,
2351
2352	.memory_pressure	= &tcp_memory_pressure,
2353	.orphan_count		= &tcp_orphan_count,
2354	.sysctl_mem		= sysctl_tcp_mem,
2355	.sysctl_wmem_offset	= offsetof(struct net, ipv4.sysctl_tcp_wmem),
2356	.sysctl_rmem_offset	= offsetof(struct net, ipv4.sysctl_tcp_rmem),
2357	.max_header		= MAX_TCP_HEADER,
2358	.obj_size		= sizeof(struct tcp6_sock),
2359	.ipv6_pinfo_offset = offsetof(struct tcp6_sock, inet6),
2360	.slab_flags		= SLAB_TYPESAFE_BY_RCU,
2361	.twsk_prot		= &tcp6_timewait_sock_ops,
2362	.rsk_prot		= &tcp6_request_sock_ops,
2363	.h.hashinfo		= NULL,
2364	.no_autobind		= true,
2365	.diag_destroy		= tcp_abort,
2366};
2367EXPORT_SYMBOL_GPL(tcpv6_prot);
2368
 
 
 
 
 
2369
2370static struct inet_protosw tcpv6_protosw = {
2371	.type		=	SOCK_STREAM,
2372	.protocol	=	IPPROTO_TCP,
2373	.prot		=	&tcpv6_prot,
2374	.ops		=	&inet6_stream_ops,
2375	.flags		=	INET_PROTOSW_PERMANENT |
2376				INET_PROTOSW_ICSK,
2377};
2378
2379static int __net_init tcpv6_net_init(struct net *net)
2380{
2381	return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
2382				    SOCK_RAW, IPPROTO_TCP, net);
2383}
2384
2385static void __net_exit tcpv6_net_exit(struct net *net)
2386{
2387	inet_ctl_sock_destroy(net->ipv6.tcp_sk);
2388}
2389
2390static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
2391{
2392	tcp_twsk_purge(net_exit_list, AF_INET6);
2393}
2394
2395static struct pernet_operations tcpv6_net_ops = {
2396	.init	    = tcpv6_net_init,
2397	.exit	    = tcpv6_net_exit,
2398	.exit_batch = tcpv6_net_exit_batch,
2399};
2400
2401int __init tcpv6_init(void)
2402{
2403	int ret;
2404
2405	net_hotdata.tcpv6_protocol = (struct inet6_protocol) {
2406		.handler     = tcp_v6_rcv,
2407		.err_handler = tcp_v6_err,
2408		.flags	     = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
2409	};
2410	ret = inet6_add_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2411	if (ret)
2412		goto out;
2413
2414	/* register inet6 protocol */
2415	ret = inet6_register_protosw(&tcpv6_protosw);
2416	if (ret)
2417		goto out_tcpv6_protocol;
2418
2419	ret = register_pernet_subsys(&tcpv6_net_ops);
2420	if (ret)
2421		goto out_tcpv6_protosw;
2422
2423	ret = mptcpv6_init();
2424	if (ret)
2425		goto out_tcpv6_pernet_subsys;
2426
2427out:
2428	return ret;
2429
2430out_tcpv6_pernet_subsys:
2431	unregister_pernet_subsys(&tcpv6_net_ops);
2432out_tcpv6_protosw:
2433	inet6_unregister_protosw(&tcpv6_protosw);
2434out_tcpv6_protocol:
2435	inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2436	goto out;
2437}
2438
2439void tcpv6_exit(void)
2440{
2441	unregister_pernet_subsys(&tcpv6_net_ops);
2442	inet6_unregister_protosw(&tcpv6_protosw);
2443	inet6_del_protocol(&net_hotdata.tcpv6_protocol, IPPROTO_TCP);
2444}