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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /net/ipv6/tcp_ipv6.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
-rw-r--r--net/ipv6/tcp_ipv6.c2271
1 files changed, 2271 insertions, 0 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
new file mode 100644
index 000000000..ba9a22db5
--- /dev/null
+++ b/net/ipv6/tcp_ipv6.c
@@ -0,0 +1,2271 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TCP over IPv6
+ * Linux INET6 implementation
+ *
+ * Authors:
+ * Pedro Roque <roque@di.fc.ul.pt>
+ *
+ * Based on:
+ * linux/net/ipv4/tcp.c
+ * linux/net/ipv4/tcp_input.c
+ * linux/net/ipv4/tcp_output.c
+ *
+ * Fixes:
+ * Hideaki YOSHIFUJI : sin6_scope_id support
+ * YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
+ * Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
+ * a single port at the same time.
+ * YOSHIFUJI Hideaki @USAGI: convert /proc/net/tcp6 to seq_file.
+ */
+
+#include <linux/bottom_half.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/jiffies.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <linux/netdevice.h>
+#include <linux/init.h>
+#include <linux/jhash.h>
+#include <linux/ipsec.h>
+#include <linux/times.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/ipv6.h>
+#include <linux/icmpv6.h>
+#include <linux/random.h>
+#include <linux/indirect_call_wrapper.h>
+
+#include <net/tcp.h>
+#include <net/ndisc.h>
+#include <net/inet6_hashtables.h>
+#include <net/inet6_connection_sock.h>
+#include <net/ipv6.h>
+#include <net/transp_v6.h>
+#include <net/addrconf.h>
+#include <net/ip6_route.h>
+#include <net/ip6_checksum.h>
+#include <net/inet_ecn.h>
+#include <net/protocol.h>
+#include <net/xfrm.h>
+#include <net/snmp.h>
+#include <net/dsfield.h>
+#include <net/timewait_sock.h>
+#include <net/inet_common.h>
+#include <net/secure_seq.h>
+#include <net/busy_poll.h>
+
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+
+#include <crypto/hash.h>
+#include <linux/scatterlist.h>
+
+#include <trace/events/tcp.h>
+
+static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb);
+static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
+ struct request_sock *req);
+
+INDIRECT_CALLABLE_SCOPE int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
+
+static const struct inet_connection_sock_af_ops ipv6_mapped;
+const struct inet_connection_sock_af_ops ipv6_specific;
+#ifdef CONFIG_TCP_MD5SIG
+static const struct tcp_sock_af_ops tcp_sock_ipv6_specific;
+static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific;
+#else
+static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr,
+ int l3index)
+{
+ return NULL;
+}
+#endif
+
+/* Helper returning the inet6 address from a given tcp socket.
+ * It can be used in TCP stack instead of inet6_sk(sk).
+ * This avoids a dereference and allow compiler optimizations.
+ * It is a specialized version of inet6_sk_generic().
+ */
+static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk)
+{
+ unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo);
+
+ return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
+}
+
+static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
+{
+ struct dst_entry *dst = skb_dst(skb);
+
+ if (dst && dst_hold_safe(dst)) {
+ const struct rt6_info *rt = (const struct rt6_info *)dst;
+
+ rcu_assign_pointer(sk->sk_rx_dst, dst);
+ sk->sk_rx_dst_ifindex = skb->skb_iif;
+ sk->sk_rx_dst_cookie = rt6_get_cookie(rt);
+ }
+}
+
+static u32 tcp_v6_init_seq(const struct sk_buff *skb)
+{
+ return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32,
+ ipv6_hdr(skb)->saddr.s6_addr32,
+ tcp_hdr(skb)->dest,
+ tcp_hdr(skb)->source);
+}
+
+static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb)
+{
+ return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32,
+ ipv6_hdr(skb)->saddr.s6_addr32);
+}
+
+static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr,
+ int addr_len)
+{
+ /* This check is replicated from tcp_v6_connect() and intended to
+ * prevent BPF program called below from accessing bytes that are out
+ * of the bound specified by user in addr_len.
+ */
+ if (addr_len < SIN6_LEN_RFC2133)
+ return -EINVAL;
+
+ sock_owned_by_me(sk);
+
+ return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr);
+}
+
+static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
+ int addr_len)
+{
+ struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;
+ struct inet_connection_sock *icsk = inet_csk(sk);
+ struct in6_addr *saddr = NULL, *final_p, final;
+ struct inet_timewait_death_row *tcp_death_row;
+ struct ipv6_pinfo *np = tcp_inet6_sk(sk);
+ struct inet_sock *inet = inet_sk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct net *net = sock_net(sk);
+ struct ipv6_txoptions *opt;
+ struct dst_entry *dst;
+ struct flowi6 fl6;
+ int addr_type;
+ int err;
+
+ if (addr_len < SIN6_LEN_RFC2133)
+ return -EINVAL;
+
+ if (usin->sin6_family != AF_INET6)
+ return -EAFNOSUPPORT;
+
+ memset(&fl6, 0, sizeof(fl6));
+
+ if (np->sndflow) {
+ fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;
+ IP6_ECN_flow_init(fl6.flowlabel);
+ if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {
+ struct ip6_flowlabel *flowlabel;
+ flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);
+ if (IS_ERR(flowlabel))
+ return -EINVAL;
+ fl6_sock_release(flowlabel);
+ }
+ }
+
+ /*
+ * connect() to INADDR_ANY means loopback (BSD'ism).
+ */
+
+ if (ipv6_addr_any(&usin->sin6_addr)) {
+ if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
+ ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK),
+ &usin->sin6_addr);
+ else
+ usin->sin6_addr = in6addr_loopback;
+ }
+
+ addr_type = ipv6_addr_type(&usin->sin6_addr);
+
+ if (addr_type & IPV6_ADDR_MULTICAST)
+ return -ENETUNREACH;
+
+ if (addr_type&IPV6_ADDR_LINKLOCAL) {
+ if (addr_len >= sizeof(struct sockaddr_in6) &&
+ usin->sin6_scope_id) {
+ /* If interface is set while binding, indices
+ * must coincide.
+ */
+ if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id))
+ return -EINVAL;
+
+ sk->sk_bound_dev_if = usin->sin6_scope_id;
+ }
+
+ /* Connect to link-local address requires an interface */
+ if (!sk->sk_bound_dev_if)
+ return -EINVAL;
+ }
+
+ if (tp->rx_opt.ts_recent_stamp &&
+ !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) {
+ tp->rx_opt.ts_recent = 0;
+ tp->rx_opt.ts_recent_stamp = 0;
+ WRITE_ONCE(tp->write_seq, 0);
+ }
+
+ sk->sk_v6_daddr = usin->sin6_addr;
+ np->flow_label = fl6.flowlabel;
+
+ /*
+ * TCP over IPv4
+ */
+
+ if (addr_type & IPV6_ADDR_MAPPED) {
+ u32 exthdrlen = icsk->icsk_ext_hdr_len;
+ struct sockaddr_in sin;
+
+ if (ipv6_only_sock(sk))
+ return -ENETUNREACH;
+
+ sin.sin_family = AF_INET;
+ sin.sin_port = usin->sin6_port;
+ sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3];
+
+ /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
+ WRITE_ONCE(icsk->icsk_af_ops, &ipv6_mapped);
+ if (sk_is_mptcp(sk))
+ mptcpv6_handle_mapped(sk, true);
+ sk->sk_backlog_rcv = tcp_v4_do_rcv;
+#ifdef CONFIG_TCP_MD5SIG
+ tp->af_specific = &tcp_sock_ipv6_mapped_specific;
+#endif
+
+ err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin));
+
+ if (err) {
+ icsk->icsk_ext_hdr_len = exthdrlen;
+ /* Paired with READ_ONCE() in tcp_(get|set)sockopt() */
+ WRITE_ONCE(icsk->icsk_af_ops, &ipv6_specific);
+ if (sk_is_mptcp(sk))
+ mptcpv6_handle_mapped(sk, false);
+ sk->sk_backlog_rcv = tcp_v6_do_rcv;
+#ifdef CONFIG_TCP_MD5SIG
+ tp->af_specific = &tcp_sock_ipv6_specific;
+#endif
+ goto failure;
+ }
+ np->saddr = sk->sk_v6_rcv_saddr;
+
+ return err;
+ }
+
+ if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))
+ saddr = &sk->sk_v6_rcv_saddr;
+
+ fl6.flowi6_proto = IPPROTO_TCP;
+ fl6.daddr = sk->sk_v6_daddr;
+ fl6.saddr = saddr ? *saddr : np->saddr;
+ fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);
+ fl6.flowi6_oif = sk->sk_bound_dev_if;
+ fl6.flowi6_mark = sk->sk_mark;
+ fl6.fl6_dport = usin->sin6_port;
+ fl6.fl6_sport = inet->inet_sport;
+ fl6.flowi6_uid = sk->sk_uid;
+
+ opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));
+ final_p = fl6_update_dst(&fl6, opt, &final);
+
+ security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));
+
+ dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
+ if (IS_ERR(dst)) {
+ err = PTR_ERR(dst);
+ goto failure;
+ }
+
+ tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;
+
+ if (!saddr) {
+ saddr = &fl6.saddr;
+
+ err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);
+ if (err)
+ goto failure;
+ }
+
+ /* set the source address */
+ np->saddr = *saddr;
+ inet->inet_rcv_saddr = LOOPBACK4_IPV6;
+
+ sk->sk_gso_type = SKB_GSO_TCPV6;
+ ip6_dst_store(sk, dst, NULL, NULL);
+
+ icsk->icsk_ext_hdr_len = 0;
+ if (opt)
+ icsk->icsk_ext_hdr_len = opt->opt_flen +
+ opt->opt_nflen;
+
+ tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
+
+ inet->inet_dport = usin->sin6_port;
+
+ tcp_set_state(sk, TCP_SYN_SENT);
+ err = inet6_hash_connect(tcp_death_row, sk);
+ if (err)
+ goto late_failure;
+
+ sk_set_txhash(sk);
+
+ if (likely(!tp->repair)) {
+ if (!tp->write_seq)
+ WRITE_ONCE(tp->write_seq,
+ secure_tcpv6_seq(np->saddr.s6_addr32,
+ sk->sk_v6_daddr.s6_addr32,
+ inet->inet_sport,
+ inet->inet_dport));
+ tp->tsoffset = secure_tcpv6_ts_off(net, np->saddr.s6_addr32,
+ sk->sk_v6_daddr.s6_addr32);
+ }
+
+ if (tcp_fastopen_defer_connect(sk, &err))
+ return err;
+ if (err)
+ goto late_failure;
+
+ err = tcp_connect(sk);
+ if (err)
+ goto late_failure;
+
+ return 0;
+
+late_failure:
+ tcp_set_state(sk, TCP_CLOSE);
+ inet_bhash2_reset_saddr(sk);
+failure:
+ inet->inet_dport = 0;
+ sk->sk_route_caps = 0;
+ return err;
+}
+
+static void tcp_v6_mtu_reduced(struct sock *sk)
+{
+ struct dst_entry *dst;
+ u32 mtu;
+
+ if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))
+ return;
+
+ mtu = READ_ONCE(tcp_sk(sk)->mtu_info);
+
+ /* Drop requests trying to increase our current mss.
+ * Check done in __ip6_rt_update_pmtu() is too late.
+ */
+ if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache)
+ return;
+
+ dst = inet6_csk_update_pmtu(sk, mtu);
+ if (!dst)
+ return;
+
+ if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) {
+ tcp_sync_mss(sk, dst_mtu(dst));
+ tcp_simple_retransmit(sk);
+ }
+}
+
+static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
+ u8 type, u8 code, int offset, __be32 info)
+{
+ const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
+ const struct tcphdr *th = (struct tcphdr *)(skb->data+offset);
+ struct net *net = dev_net(skb->dev);
+ struct request_sock *fastopen;
+ struct ipv6_pinfo *np;
+ struct tcp_sock *tp;
+ __u32 seq, snd_una;
+ struct sock *sk;
+ bool fatal;
+ int err;
+
+ sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
+ &hdr->daddr, th->dest,
+ &hdr->saddr, ntohs(th->source),
+ skb->dev->ifindex, inet6_sdif(skb));
+
+ if (!sk) {
+ __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev),
+ ICMP6_MIB_INERRORS);
+ return -ENOENT;
+ }
+
+ if (sk->sk_state == TCP_TIME_WAIT) {
+ inet_twsk_put(inet_twsk(sk));
+ return 0;
+ }
+ seq = ntohl(th->seq);
+ fatal = icmpv6_err_convert(type, code, &err);
+ if (sk->sk_state == TCP_NEW_SYN_RECV) {
+ tcp_req_err(sk, seq, fatal);
+ return 0;
+ }
+
+ bh_lock_sock(sk);
+ if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG)
+ __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS);
+
+ if (sk->sk_state == TCP_CLOSE)
+ goto out;
+
+ if (static_branch_unlikely(&ip6_min_hopcount)) {
+ /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
+ if (ipv6_hdr(skb)->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) {
+ __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
+ goto out;
+ }
+ }
+
+ tp = tcp_sk(sk);
+ /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
+ fastopen = rcu_dereference(tp->fastopen_rsk);
+ snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
+ if (sk->sk_state != TCP_LISTEN &&
+ !between(seq, snd_una, tp->snd_nxt)) {
+ __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS);
+ goto out;
+ }
+
+ np = tcp_inet6_sk(sk);
+
+ if (type == NDISC_REDIRECT) {
+ if (!sock_owned_by_user(sk)) {
+ struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie);
+
+ if (dst)
+ dst->ops->redirect(dst, sk, skb);
+ }
+ goto out;
+ }
+
+ if (type == ICMPV6_PKT_TOOBIG) {
+ u32 mtu = ntohl(info);
+
+ /* We are not interested in TCP_LISTEN and open_requests
+ * (SYN-ACKs send out by Linux are always <576bytes so
+ * they should go through unfragmented).
+ */
+ if (sk->sk_state == TCP_LISTEN)
+ goto out;
+
+ if (!ip6_sk_accept_pmtu(sk))
+ goto out;
+
+ if (mtu < IPV6_MIN_MTU)
+ goto out;
+
+ WRITE_ONCE(tp->mtu_info, mtu);
+
+ if (!sock_owned_by_user(sk))
+ tcp_v6_mtu_reduced(sk);
+ else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,
+ &sk->sk_tsq_flags))
+ sock_hold(sk);
+ goto out;
+ }
+
+
+ /* Might be for an request_sock */
+ switch (sk->sk_state) {
+ case TCP_SYN_SENT:
+ case TCP_SYN_RECV:
+ /* Only in fast or simultaneous open. If a fast open socket is
+ * already accepted it is treated as a connected one below.
+ */
+ if (fastopen && !fastopen->sk)
+ break;
+
+ ipv6_icmp_error(sk, skb, err, th->dest, ntohl(info), (u8 *)th);
+
+ if (!sock_owned_by_user(sk)) {
+ sk->sk_err = err;
+ sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
+
+ tcp_done(sk);
+ } else
+ sk->sk_err_soft = err;
+ goto out;
+ case TCP_LISTEN:
+ break;
+ default:
+ /* check if this ICMP message allows revert of backoff.
+ * (see RFC 6069)
+ */
+ if (!fastopen && type == ICMPV6_DEST_UNREACH &&
+ code == ICMPV6_NOROUTE)
+ tcp_ld_RTO_revert(sk, seq);
+ }
+
+ if (!sock_owned_by_user(sk) && np->recverr) {
+ sk->sk_err = err;
+ sk_error_report(sk);
+ } else
+ sk->sk_err_soft = err;
+
+out:
+ bh_unlock_sock(sk);
+ sock_put(sk);
+ return 0;
+}
+
+
+static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
+ struct flowi *fl,
+ struct request_sock *req,
+ struct tcp_fastopen_cookie *foc,
+ enum tcp_synack_type synack_type,
+ struct sk_buff *syn_skb)
+{
+ struct inet_request_sock *ireq = inet_rsk(req);
+ struct ipv6_pinfo *np = tcp_inet6_sk(sk);
+ struct ipv6_txoptions *opt;
+ struct flowi6 *fl6 = &fl->u.ip6;
+ struct sk_buff *skb;
+ int err = -ENOMEM;
+ u8 tclass;
+
+ /* First, grab a route. */
+ if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,
+ IPPROTO_TCP)) == NULL)
+ goto done;
+
+ skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb);
+
+ if (skb) {
+ __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr,
+ &ireq->ir_v6_rmt_addr);
+
+ fl6->daddr = ireq->ir_v6_rmt_addr;
+ if (np->repflow && ireq->pktopts)
+ fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
+
+ tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
+ (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
+ (np->tclass & INET_ECN_MASK) :
+ np->tclass;
+
+ if (!INET_ECN_is_capable(tclass) &&
+ tcp_bpf_ca_needs_ecn((struct sock *)req))
+ tclass |= INET_ECN_ECT_0;
+
+ rcu_read_lock();
+ opt = ireq->ipv6_opt;
+ if (!opt)
+ opt = rcu_dereference(np->opt);
+ err = ip6_xmit(sk, skb, fl6, skb->mark ? : READ_ONCE(sk->sk_mark),
+ opt, tclass, sk->sk_priority);
+ rcu_read_unlock();
+ err = net_xmit_eval(err);
+ }
+
+done:
+ return err;
+}
+
+
+static void tcp_v6_reqsk_destructor(struct request_sock *req)
+{
+ kfree(inet_rsk(req)->ipv6_opt);
+ consume_skb(inet_rsk(req)->pktopts);
+}
+
+#ifdef CONFIG_TCP_MD5SIG
+static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk,
+ const struct in6_addr *addr,
+ int l3index)
+{
+ return tcp_md5_do_lookup(sk, l3index,
+ (union tcp_md5_addr *)addr, AF_INET6);
+}
+
+static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk,
+ const struct sock *addr_sk)
+{
+ int l3index;
+
+ l3index = l3mdev_master_ifindex_by_index(sock_net(sk),
+ addr_sk->sk_bound_dev_if);
+ return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr,
+ l3index);
+}
+
+static int tcp_v6_parse_md5_keys(struct sock *sk, int optname,
+ sockptr_t optval, int optlen)
+{
+ struct tcp_md5sig cmd;
+ struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr;
+ int l3index = 0;
+ u8 prefixlen;
+ u8 flags;
+
+ if (optlen < sizeof(cmd))
+ return -EINVAL;
+
+ if (copy_from_sockptr(&cmd, optval, sizeof(cmd)))
+ return -EFAULT;
+
+ if (sin6->sin6_family != AF_INET6)
+ return -EINVAL;
+
+ flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX;
+
+ if (optname == TCP_MD5SIG_EXT &&
+ cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) {
+ prefixlen = cmd.tcpm_prefixlen;
+ if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) &&
+ prefixlen > 32))
+ return -EINVAL;
+ } else {
+ prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128;
+ }
+
+ if (optname == TCP_MD5SIG_EXT && cmd.tcpm_ifindex &&
+ cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
+ struct net_device *dev;
+
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
+ if (dev && netif_is_l3_master(dev))
+ l3index = dev->ifindex;
+ rcu_read_unlock();
+
+ /* ok to reference set/not set outside of rcu;
+ * right now device MUST be an L3 master
+ */
+ if (!dev || !l3index)
+ return -EINVAL;
+ }
+
+ if (!cmd.tcpm_keylen) {
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr))
+ return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
+ AF_INET, prefixlen,
+ l3index, flags);
+ return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
+ AF_INET6, prefixlen, l3index, flags);
+ }
+
+ if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
+ return -EINVAL;
+
+ if (ipv6_addr_v4mapped(&sin6->sin6_addr))
+ return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3],
+ AF_INET, prefixlen, l3index, flags,
+ cmd.tcpm_key, cmd.tcpm_keylen,
+ GFP_KERNEL);
+
+ return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr,
+ AF_INET6, prefixlen, l3index, flags,
+ cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
+}
+
+static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp,
+ const struct in6_addr *daddr,
+ const struct in6_addr *saddr,
+ const struct tcphdr *th, int nbytes)
+{
+ struct tcp6_pseudohdr *bp;
+ struct scatterlist sg;
+ struct tcphdr *_th;
+
+ bp = hp->scratch;
+ /* 1. TCP pseudo-header (RFC2460) */
+ bp->saddr = *saddr;
+ bp->daddr = *daddr;
+ bp->protocol = cpu_to_be32(IPPROTO_TCP);
+ bp->len = cpu_to_be32(nbytes);
+
+ _th = (struct tcphdr *)(bp + 1);
+ memcpy(_th, th, sizeof(*th));
+ _th->check = 0;
+
+ sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th));
+ ahash_request_set_crypt(hp->md5_req, &sg, NULL,
+ sizeof(*bp) + sizeof(*th));
+ return crypto_ahash_update(hp->md5_req);
+}
+
+static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key,
+ const struct in6_addr *daddr, struct in6_addr *saddr,
+ const struct tcphdr *th)
+{
+ struct tcp_md5sig_pool *hp;
+ struct ahash_request *req;
+
+ hp = tcp_get_md5sig_pool();
+ if (!hp)
+ goto clear_hash_noput;
+ req = hp->md5_req;
+
+ if (crypto_ahash_init(req))
+ goto clear_hash;
+ if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2))
+ goto clear_hash;
+ if (tcp_md5_hash_key(hp, key))
+ goto clear_hash;
+ ahash_request_set_crypt(req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(req))
+ goto clear_hash;
+
+ tcp_put_md5sig_pool();
+ return 0;
+
+clear_hash:
+ tcp_put_md5sig_pool();
+clear_hash_noput:
+ memset(md5_hash, 0, 16);
+ return 1;
+}
+
+static int tcp_v6_md5_hash_skb(char *md5_hash,
+ const struct tcp_md5sig_key *key,
+ const struct sock *sk,
+ const struct sk_buff *skb)
+{
+ const struct in6_addr *saddr, *daddr;
+ struct tcp_md5sig_pool *hp;
+ struct ahash_request *req;
+ const struct tcphdr *th = tcp_hdr(skb);
+
+ if (sk) { /* valid for establish/request sockets */
+ saddr = &sk->sk_v6_rcv_saddr;
+ daddr = &sk->sk_v6_daddr;
+ } else {
+ const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+ saddr = &ip6h->saddr;
+ daddr = &ip6h->daddr;
+ }
+
+ hp = tcp_get_md5sig_pool();
+ if (!hp)
+ goto clear_hash_noput;
+ req = hp->md5_req;
+
+ if (crypto_ahash_init(req))
+ goto clear_hash;
+
+ if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len))
+ goto clear_hash;
+ if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
+ goto clear_hash;
+ if (tcp_md5_hash_key(hp, key))
+ goto clear_hash;
+ ahash_request_set_crypt(req, NULL, md5_hash, 0);
+ if (crypto_ahash_final(req))
+ goto clear_hash;
+
+ tcp_put_md5sig_pool();
+ return 0;
+
+clear_hash:
+ tcp_put_md5sig_pool();
+clear_hash_noput:
+ memset(md5_hash, 0, 16);
+ return 1;
+}
+
+#endif
+
+static void tcp_v6_init_req(struct request_sock *req,
+ const struct sock *sk_listener,
+ struct sk_buff *skb)
+{
+ bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags);
+ struct inet_request_sock *ireq = inet_rsk(req);
+ const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener);
+
+ ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
+ ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
+
+ /* So that link locals have meaning */
+ if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
+ ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
+ ireq->ir_iif = tcp_v6_iif(skb);
+
+ if (!TCP_SKB_CB(skb)->tcp_tw_isn &&
+ (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) ||
+ np->rxopt.bits.rxinfo ||
+ np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim ||
+ np->rxopt.bits.rxohlim || np->repflow)) {
+ refcount_inc(&skb->users);
+ ireq->pktopts = skb;
+ }
+}
+
+static struct dst_entry *tcp_v6_route_req(const struct sock *sk,
+ struct sk_buff *skb,
+ struct flowi *fl,
+ struct request_sock *req)
+{
+ tcp_v6_init_req(req, sk, skb);
+
+ if (security_inet_conn_request(sk, skb, req))
+ return NULL;
+
+ return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);
+}
+
+struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
+ .family = AF_INET6,
+ .obj_size = sizeof(struct tcp6_request_sock),
+ .rtx_syn_ack = tcp_rtx_synack,
+ .send_ack = tcp_v6_reqsk_send_ack,
+ .destructor = tcp_v6_reqsk_destructor,
+ .send_reset = tcp_v6_send_reset,
+ .syn_ack_timeout = tcp_syn_ack_timeout,
+};
+
+const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
+ .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) -
+ sizeof(struct ipv6hdr),
+#ifdef CONFIG_TCP_MD5SIG
+ .req_md5_lookup = tcp_v6_md5_lookup,
+ .calc_md5_hash = tcp_v6_md5_hash_skb,
+#endif
+#ifdef CONFIG_SYN_COOKIES
+ .cookie_init_seq = cookie_v6_init_sequence,
+#endif
+ .route_req = tcp_v6_route_req,
+ .init_seq = tcp_v6_init_seq,
+ .init_ts_off = tcp_v6_init_ts_off,
+ .send_synack = tcp_v6_send_synack,
+};
+
+static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq,
+ u32 ack, u32 win, u32 tsval, u32 tsecr,
+ int oif, struct tcp_md5sig_key *key, int rst,
+ u8 tclass, __be32 label, u32 priority, u32 txhash)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ struct tcphdr *t1;
+ struct sk_buff *buff;
+ struct flowi6 fl6;
+ struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
+ struct sock *ctl_sk = net->ipv6.tcp_sk;
+ unsigned int tot_len = sizeof(struct tcphdr);
+ __be32 mrst = 0, *topt;
+ struct dst_entry *dst;
+ __u32 mark = 0;
+
+ if (tsecr)
+ tot_len += TCPOLEN_TSTAMP_ALIGNED;
+#ifdef CONFIG_TCP_MD5SIG
+ if (key)
+ tot_len += TCPOLEN_MD5SIG_ALIGNED;
+#endif
+
+#ifdef CONFIG_MPTCP
+ if (rst && !key) {
+ mrst = mptcp_reset_option(skb);
+
+ if (mrst)
+ tot_len += sizeof(__be32);
+ }
+#endif
+
+ buff = alloc_skb(MAX_TCP_HEADER, GFP_ATOMIC);
+ if (!buff)
+ return;
+
+ skb_reserve(buff, MAX_TCP_HEADER);
+
+ t1 = skb_push(buff, tot_len);
+ skb_reset_transport_header(buff);
+
+ /* Swap the send and the receive. */
+ memset(t1, 0, sizeof(*t1));
+ t1->dest = th->source;
+ t1->source = th->dest;
+ t1->doff = tot_len / 4;
+ t1->seq = htonl(seq);
+ t1->ack_seq = htonl(ack);
+ t1->ack = !rst || !th->ack;
+ t1->rst = rst;
+ t1->window = htons(win);
+
+ topt = (__be32 *)(t1 + 1);
+
+ if (tsecr) {
+ *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+ (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP);
+ *topt++ = htonl(tsval);
+ *topt++ = htonl(tsecr);
+ }
+
+ if (mrst)
+ *topt++ = mrst;
+
+#ifdef CONFIG_TCP_MD5SIG
+ if (key) {
+ *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
+ (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG);
+ tcp_v6_md5_hash_hdr((__u8 *)topt, key,
+ &ipv6_hdr(skb)->saddr,
+ &ipv6_hdr(skb)->daddr, t1);
+ }
+#endif
+
+ memset(&fl6, 0, sizeof(fl6));
+ fl6.daddr = ipv6_hdr(skb)->saddr;
+ fl6.saddr = ipv6_hdr(skb)->daddr;
+ fl6.flowlabel = label;
+
+ buff->ip_summed = CHECKSUM_PARTIAL;
+
+ __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr);
+
+ fl6.flowi6_proto = IPPROTO_TCP;
+ if (rt6_need_strict(&fl6.daddr) && !oif)
+ fl6.flowi6_oif = tcp_v6_iif(skb);
+ else {
+ if (!oif && netif_index_is_l3_master(net, skb->skb_iif))
+ oif = skb->skb_iif;
+
+ fl6.flowi6_oif = oif;
+ }
+
+ if (sk) {
+ if (sk->sk_state == TCP_TIME_WAIT)
+ mark = inet_twsk(sk)->tw_mark;
+ else
+ mark = READ_ONCE(sk->sk_mark);
+ skb_set_delivery_time(buff, tcp_transmit_time(sk), true);
+ }
+ if (txhash) {
+ /* autoflowlabel/skb_get_hash_flowi6 rely on buff->hash */
+ skb_set_hash(buff, txhash, PKT_HASH_TYPE_L4);
+ }
+ fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark;
+ fl6.fl6_dport = t1->dest;
+ fl6.fl6_sport = t1->source;
+ fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
+ security_skb_classify_flow(skb, flowi6_to_flowi_common(&fl6));
+
+ /* Pass a socket to ip6_dst_lookup either it is for RST
+ * Underlying function will use this to retrieve the network
+ * namespace
+ */
+ if (sk && sk->sk_state != TCP_TIME_WAIT)
+ dst = ip6_dst_lookup_flow(net, sk, &fl6, NULL); /*sk's xfrm_policy can be referred*/
+ else
+ dst = ip6_dst_lookup_flow(net, ctl_sk, &fl6, NULL);
+ if (!IS_ERR(dst)) {
+ skb_dst_set(buff, dst);
+ ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL,
+ tclass & ~INET_ECN_MASK, priority);
+ TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
+ if (rst)
+ TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
+ return;
+ }
+
+ kfree_skb(buff);
+}
+
+static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ u32 seq = 0, ack_seq = 0;
+ struct tcp_md5sig_key *key = NULL;
+#ifdef CONFIG_TCP_MD5SIG
+ const __u8 *hash_location = NULL;
+ unsigned char newhash[16];
+ int genhash;
+ struct sock *sk1 = NULL;
+#endif
+ __be32 label = 0;
+ u32 priority = 0;
+ struct net *net;
+ u32 txhash = 0;
+ int oif = 0;
+
+ if (th->rst)
+ return;
+
+ /* If sk not NULL, it means we did a successful lookup and incoming
+ * route had to be correct. prequeue might have dropped our dst.
+ */
+ if (!sk && !ipv6_unicast_destination(skb))
+ return;
+
+ net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev);
+#ifdef CONFIG_TCP_MD5SIG
+ rcu_read_lock();
+ hash_location = tcp_parse_md5sig_option(th);
+ if (sk && sk_fullsock(sk)) {
+ int l3index;
+
+ /* sdif set, means packet ingressed via a device
+ * in an L3 domain and inet_iif is set to it.
+ */
+ l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
+ key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr, l3index);
+ } else if (hash_location) {
+ int dif = tcp_v6_iif_l3_slave(skb);
+ int sdif = tcp_v6_sdif(skb);
+ int l3index;
+
+ /*
+ * active side is lost. Try to find listening socket through
+ * source port, and then find md5 key through listening socket.
+ * we are not loose security here:
+ * Incoming packet is checked with md5 hash with finding key,
+ * no RST generated if md5 hash doesn't match.
+ */
+ sk1 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
+ NULL, 0, &ipv6h->saddr, th->source,
+ &ipv6h->daddr, ntohs(th->source),
+ dif, sdif);
+ if (!sk1)
+ goto out;
+
+ /* sdif set, means packet ingressed via a device
+ * in an L3 domain and dif is set to it.
+ */
+ l3index = tcp_v6_sdif(skb) ? dif : 0;
+
+ key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr, l3index);
+ if (!key)
+ goto out;
+
+ genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
+ if (genhash || memcmp(hash_location, newhash, 16) != 0)
+ goto out;
+ }
+#endif
+
+ if (th->ack)
+ seq = ntohl(th->ack_seq);
+ else
+ ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len -
+ (th->doff << 2);
+
+ if (sk) {
+ oif = sk->sk_bound_dev_if;
+ if (sk_fullsock(sk)) {
+ const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
+
+ trace_tcp_send_reset(sk, skb);
+ if (np->repflow)
+ label = ip6_flowlabel(ipv6h);
+ priority = sk->sk_priority;
+ txhash = sk->sk_txhash;
+ }
+ if (sk->sk_state == TCP_TIME_WAIT) {
+ label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel);
+ priority = inet_twsk(sk)->tw_priority;
+ txhash = inet_twsk(sk)->tw_txhash;
+ }
+ } else {
+ if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET)
+ label = ip6_flowlabel(ipv6h);
+ }
+
+ tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1,
+ ipv6_get_dsfield(ipv6h), label, priority, txhash);
+
+#ifdef CONFIG_TCP_MD5SIG
+out:
+ rcu_read_unlock();
+#endif
+}
+
+static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq,
+ u32 ack, u32 win, u32 tsval, u32 tsecr, int oif,
+ struct tcp_md5sig_key *key, u8 tclass,
+ __be32 label, u32 priority, u32 txhash)
+{
+ tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0,
+ tclass, label, priority, txhash);
+}
+
+static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb)
+{
+ struct inet_timewait_sock *tw = inet_twsk(sk);
+ struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
+
+ tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
+ tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
+ tcp_time_stamp_raw() + tcptw->tw_ts_offset,
+ tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw),
+ tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority,
+ tw->tw_txhash);
+
+ inet_twsk_put(tw);
+}
+
+static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb,
+ struct request_sock *req)
+{
+ int l3index;
+
+ l3index = tcp_v6_sdif(skb) ? tcp_v6_iif_l3_slave(skb) : 0;
+
+ /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV
+ * sk->sk_state == TCP_SYN_RECV -> for Fast Open.
+ */
+ /* RFC 7323 2.3
+ * The window field (SEG.WND) of every outgoing segment, with the
+ * exception of <SYN> segments, MUST be right-shifted by
+ * Rcv.Wind.Shift bits:
+ */
+ tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ?
+ tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt,
+ tcp_rsk(req)->rcv_nxt,
+ req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale,
+ tcp_time_stamp_raw() + tcp_rsk(req)->ts_off,
+ READ_ONCE(req->ts_recent), sk->sk_bound_dev_if,
+ tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr, l3index),
+ ipv6_get_dsfield(ipv6_hdr(skb)), 0,
+ READ_ONCE(sk->sk_priority),
+ READ_ONCE(tcp_rsk(req)->txhash));
+}
+
+
+static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb)
+{
+#ifdef CONFIG_SYN_COOKIES
+ const struct tcphdr *th = tcp_hdr(skb);
+
+ if (!th->syn)
+ sk = cookie_v6_check(sk, skb);
+#endif
+ return sk;
+}
+
+u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph,
+ struct tcphdr *th, u32 *cookie)
+{
+ u16 mss = 0;
+#ifdef CONFIG_SYN_COOKIES
+ mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops,
+ &tcp_request_sock_ipv6_ops, sk, th);
+ if (mss) {
+ *cookie = __cookie_v6_init_sequence(iph, th, &mss);
+ tcp_synq_overflow(sk);
+ }
+#endif
+ return mss;
+}
+
+static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
+{
+ if (skb->protocol == htons(ETH_P_IP))
+ return tcp_v4_conn_request(sk, skb);
+
+ if (!ipv6_unicast_destination(skb))
+ goto drop;
+
+ if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) {
+ __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS);
+ return 0;
+ }
+
+ return tcp_conn_request(&tcp6_request_sock_ops,
+ &tcp_request_sock_ipv6_ops, sk, skb);
+
+drop:
+ tcp_listendrop(sk);
+ return 0; /* don't send reset */
+}
+
+static void tcp_v6_restore_cb(struct sk_buff *skb)
+{
+ /* We need to move header back to the beginning if xfrm6_policy_check()
+ * and tcp_v6_fill_cb() are going to be called again.
+ * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
+ */
+ memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
+ sizeof(struct inet6_skb_parm));
+}
+
+static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
+ struct request_sock *req,
+ struct dst_entry *dst,
+ struct request_sock *req_unhash,
+ bool *own_req)
+{
+ struct inet_request_sock *ireq;
+ struct ipv6_pinfo *newnp;
+ const struct ipv6_pinfo *np = tcp_inet6_sk(sk);
+ struct ipv6_txoptions *opt;
+ struct inet_sock *newinet;
+ bool found_dup_sk = false;
+ struct tcp_sock *newtp;
+ struct sock *newsk;
+#ifdef CONFIG_TCP_MD5SIG
+ struct tcp_md5sig_key *key;
+ int l3index;
+#endif
+ struct flowi6 fl6;
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ /*
+ * v6 mapped
+ */
+
+ newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst,
+ req_unhash, own_req);
+
+ if (!newsk)
+ return NULL;
+
+ inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
+
+ newnp = tcp_inet6_sk(newsk);
+ newtp = tcp_sk(newsk);
+
+ memcpy(newnp, np, sizeof(struct ipv6_pinfo));
+
+ newnp->saddr = newsk->sk_v6_rcv_saddr;
+
+ inet_csk(newsk)->icsk_af_ops = &ipv6_mapped;
+ if (sk_is_mptcp(newsk))
+ mptcpv6_handle_mapped(newsk, true);
+ newsk->sk_backlog_rcv = tcp_v4_do_rcv;
+#ifdef CONFIG_TCP_MD5SIG
+ newtp->af_specific = &tcp_sock_ipv6_mapped_specific;
+#endif
+
+ newnp->ipv6_mc_list = NULL;
+ newnp->ipv6_ac_list = NULL;
+ newnp->ipv6_fl_list = NULL;
+ newnp->pktoptions = NULL;
+ newnp->opt = NULL;
+ newnp->mcast_oif = inet_iif(skb);
+ newnp->mcast_hops = ip_hdr(skb)->ttl;
+ newnp->rcv_flowinfo = 0;
+ if (np->repflow)
+ newnp->flow_label = 0;
+
+ /*
+ * No need to charge this sock to the relevant IPv6 refcnt debug socks count
+ * here, tcp_create_openreq_child now does this for us, see the comment in
+ * that function for the gory details. -acme
+ */
+
+ /* It is tricky place. Until this moment IPv4 tcp
+ worked with IPv6 icsk.icsk_af_ops.
+ Sync it now.
+ */
+ tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie);
+
+ return newsk;
+ }
+
+ ireq = inet_rsk(req);
+
+ if (sk_acceptq_is_full(sk))
+ goto out_overflow;
+
+ if (!dst) {
+ dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);
+ if (!dst)
+ goto out;
+ }
+
+ newsk = tcp_create_openreq_child(sk, req, skb);
+ if (!newsk)
+ goto out_nonewsk;
+
+ /*
+ * No need to charge this sock to the relevant IPv6 refcnt debug socks
+ * count here, tcp_create_openreq_child now does this for us, see the
+ * comment in that function for the gory details. -acme
+ */
+
+ newsk->sk_gso_type = SKB_GSO_TCPV6;
+ ip6_dst_store(newsk, dst, NULL, NULL);
+ inet6_sk_rx_dst_set(newsk, skb);
+
+ inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk);
+
+ newtp = tcp_sk(newsk);
+ newinet = inet_sk(newsk);
+ newnp = tcp_inet6_sk(newsk);
+
+ memcpy(newnp, np, sizeof(struct ipv6_pinfo));
+
+ newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
+ newnp->saddr = ireq->ir_v6_loc_addr;
+ newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
+ newsk->sk_bound_dev_if = ireq->ir_iif;
+
+ /* Now IPv6 options...
+
+ First: no IPv4 options.
+ */
+ newinet->inet_opt = NULL;
+ newnp->ipv6_mc_list = NULL;
+ newnp->ipv6_ac_list = NULL;
+ newnp->ipv6_fl_list = NULL;
+
+ /* Clone RX bits */
+ newnp->rxopt.all = np->rxopt.all;
+
+ newnp->pktoptions = NULL;
+ newnp->opt = NULL;
+ newnp->mcast_oif = tcp_v6_iif(skb);
+ newnp->mcast_hops = ipv6_hdr(skb)->hop_limit;
+ newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb));
+ if (np->repflow)
+ newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb));
+
+ /* Set ToS of the new socket based upon the value of incoming SYN.
+ * ECT bits are set later in tcp_init_transfer().
+ */
+ if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
+ newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
+
+ /* Clone native IPv6 options from listening socket (if any)
+
+ Yes, keeping reference count would be much more clever,
+ but we make one more one thing there: reattach optmem
+ to newsk.
+ */
+ opt = ireq->ipv6_opt;
+ if (!opt)
+ opt = rcu_dereference(np->opt);
+ if (opt) {
+ opt = ipv6_dup_options(newsk, opt);
+ RCU_INIT_POINTER(newnp->opt, opt);
+ }
+ inet_csk(newsk)->icsk_ext_hdr_len = 0;
+ if (opt)
+ inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
+ opt->opt_flen;
+
+ tcp_ca_openreq_child(newsk, dst);
+
+ tcp_sync_mss(newsk, dst_mtu(dst));
+ newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst));
+
+ tcp_initialize_rcv_mss(newsk);
+
+ newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
+ newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
+
+#ifdef CONFIG_TCP_MD5SIG
+ l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
+
+ /* Copy over the MD5 key from the original socket */
+ key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr, l3index);
+ if (key) {
+ /* We're using one, so create a matching key
+ * on the newsk structure. If we fail to get
+ * memory, then we end up not copying the key
+ * across. Shucks.
+ */
+ tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr,
+ AF_INET6, 128, l3index, key->flags, key->key, key->keylen,
+ sk_gfp_mask(sk, GFP_ATOMIC));
+ }
+#endif
+
+ if (__inet_inherit_port(sk, newsk) < 0) {
+ inet_csk_prepare_forced_close(newsk);
+ tcp_done(newsk);
+ goto out;
+ }
+ *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash),
+ &found_dup_sk);
+ if (*own_req) {
+ tcp_move_syn(newtp, req);
+
+ /* Clone pktoptions received with SYN, if we own the req */
+ if (ireq->pktopts) {
+ newnp->pktoptions = skb_clone_and_charge_r(ireq->pktopts, newsk);
+ consume_skb(ireq->pktopts);
+ ireq->pktopts = NULL;
+ if (newnp->pktoptions)
+ tcp_v6_restore_cb(newnp->pktoptions);
+ }
+ } else {
+ if (!req_unhash && found_dup_sk) {
+ /* This code path should only be executed in the
+ * syncookie case only
+ */
+ bh_unlock_sock(newsk);
+ sock_put(newsk);
+ newsk = NULL;
+ }
+ }
+
+ return newsk;
+
+out_overflow:
+ __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
+out_nonewsk:
+ dst_release(dst);
+out:
+ tcp_listendrop(sk);
+ return NULL;
+}
+
+INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
+ u32));
+/* The socket must have it's spinlock held when we get
+ * here, unless it is a TCP_LISTEN socket.
+ *
+ * We have a potential double-lock case here, so even when
+ * doing backlog processing we use the BH locking scheme.
+ * This is because we cannot sleep with the original spinlock
+ * held.
+ */
+INDIRECT_CALLABLE_SCOPE
+int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
+{
+ struct ipv6_pinfo *np = tcp_inet6_sk(sk);
+ struct sk_buff *opt_skb = NULL;
+ enum skb_drop_reason reason;
+ struct tcp_sock *tp;
+
+ /* Imagine: socket is IPv6. IPv4 packet arrives,
+ goes to IPv4 receive handler and backlogged.
+ From backlog it always goes here. Kerboom...
+ Fortunately, tcp_rcv_established and rcv_established
+ handle them correctly, but it is not case with
+ tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK
+ */
+
+ if (skb->protocol == htons(ETH_P_IP))
+ return tcp_v4_do_rcv(sk, skb);
+
+ /*
+ * socket locking is here for SMP purposes as backlog rcv
+ * is currently called with bh processing disabled.
+ */
+
+ /* Do Stevens' IPV6_PKTOPTIONS.
+
+ Yes, guys, it is the only place in our code, where we
+ may make it not affecting IPv4.
+ The rest of code is protocol independent,
+ and I do not like idea to uglify IPv4.
+
+ Actually, all the idea behind IPV6_PKTOPTIONS
+ looks not very well thought. For now we latch
+ options, received in the last packet, enqueued
+ by tcp. Feel free to propose better solution.
+ --ANK (980728)
+ */
+ if (np->rxopt.all)
+ opt_skb = skb_clone_and_charge_r(skb, sk);
+
+ reason = SKB_DROP_REASON_NOT_SPECIFIED;
+ if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
+ struct dst_entry *dst;
+
+ dst = rcu_dereference_protected(sk->sk_rx_dst,
+ lockdep_sock_is_held(sk));
+
+ sock_rps_save_rxhash(sk, skb);
+ sk_mark_napi_id(sk, skb);
+ if (dst) {
+ if (sk->sk_rx_dst_ifindex != skb->skb_iif ||
+ INDIRECT_CALL_1(dst->ops->check, ip6_dst_check,
+ dst, sk->sk_rx_dst_cookie) == NULL) {
+ RCU_INIT_POINTER(sk->sk_rx_dst, NULL);
+ dst_release(dst);
+ }
+ }
+
+ tcp_rcv_established(sk, skb);
+ if (opt_skb)
+ goto ipv6_pktoptions;
+ return 0;
+ }
+
+ if (tcp_checksum_complete(skb))
+ goto csum_err;
+
+ if (sk->sk_state == TCP_LISTEN) {
+ struct sock *nsk = tcp_v6_cookie_check(sk, skb);
+
+ if (!nsk)
+ goto discard;
+
+ if (nsk != sk) {
+ if (tcp_child_process(sk, nsk, skb))
+ goto reset;
+ if (opt_skb)
+ __kfree_skb(opt_skb);
+ return 0;
+ }
+ } else
+ sock_rps_save_rxhash(sk, skb);
+
+ if (tcp_rcv_state_process(sk, skb))
+ goto reset;
+ if (opt_skb)
+ goto ipv6_pktoptions;
+ return 0;
+
+reset:
+ tcp_v6_send_reset(sk, skb);
+discard:
+ if (opt_skb)
+ __kfree_skb(opt_skb);
+ kfree_skb_reason(skb, reason);
+ return 0;
+csum_err:
+ reason = SKB_DROP_REASON_TCP_CSUM;
+ trace_tcp_bad_csum(skb);
+ TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS);
+ TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS);
+ goto discard;
+
+
+ipv6_pktoptions:
+ /* Do you ask, what is it?
+
+ 1. skb was enqueued by tcp.
+ 2. skb is added to tail of read queue, rather than out of order.
+ 3. socket is not in passive state.
+ 4. Finally, it really contains options, which user wants to receive.
+ */
+ tp = tcp_sk(sk);
+ if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt &&
+ !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) {
+ if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
+ np->mcast_oif = tcp_v6_iif(opt_skb);
+ if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
+ np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
+ if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
+ np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
+ if (np->repflow)
+ np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
+ if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) {
+ tcp_v6_restore_cb(opt_skb);
+ opt_skb = xchg(&np->pktoptions, opt_skb);
+ } else {
+ __kfree_skb(opt_skb);
+ opt_skb = xchg(&np->pktoptions, NULL);
+ }
+ }
+
+ consume_skb(opt_skb);
+ return 0;
+}
+
+static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
+ const struct tcphdr *th)
+{
+ /* This is tricky: we move IP6CB at its correct location into
+ * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
+ * _decode_session6() uses IP6CB().
+ * barrier() makes sure compiler won't play aliasing games.
+ */
+ memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
+ sizeof(struct inet6_skb_parm));
+ barrier();
+
+ TCP_SKB_CB(skb)->seq = ntohl(th->seq);
+ TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
+ skb->len - th->doff*4);
+ TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
+ TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
+ TCP_SKB_CB(skb)->tcp_tw_isn = 0;
+ TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
+ TCP_SKB_CB(skb)->sacked = 0;
+ TCP_SKB_CB(skb)->has_rxtstamp =
+ skb->tstamp || skb_hwtstamps(skb)->hwtstamp;
+}
+
+INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
+{
+ enum skb_drop_reason drop_reason;
+ int sdif = inet6_sdif(skb);
+ int dif = inet6_iif(skb);
+ const struct tcphdr *th;
+ const struct ipv6hdr *hdr;
+ bool refcounted;
+ struct sock *sk;
+ int ret;
+ struct net *net = dev_net(skb->dev);
+
+ drop_reason = SKB_DROP_REASON_NOT_SPECIFIED;
+ if (skb->pkt_type != PACKET_HOST)
+ goto discard_it;
+
+ /*
+ * Count it even if it's bad.
+ */
+ __TCP_INC_STATS(net, TCP_MIB_INSEGS);
+
+ if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
+ goto discard_it;
+
+ th = (const struct tcphdr *)skb->data;
+
+ if (unlikely(th->doff < sizeof(struct tcphdr) / 4)) {
+ drop_reason = SKB_DROP_REASON_PKT_TOO_SMALL;
+ goto bad_packet;
+ }
+ if (!pskb_may_pull(skb, th->doff*4))
+ goto discard_it;
+
+ if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo))
+ goto csum_error;
+
+ th = (const struct tcphdr *)skb->data;
+ hdr = ipv6_hdr(skb);
+
+lookup:
+ sk = __inet6_lookup_skb(net->ipv4.tcp_death_row.hashinfo, skb, __tcp_hdrlen(th),
+ th->source, th->dest, inet6_iif(skb), sdif,
+ &refcounted);
+ if (!sk)
+ goto no_tcp_socket;
+
+process:
+ if (sk->sk_state == TCP_TIME_WAIT)
+ goto do_time_wait;
+
+ if (sk->sk_state == TCP_NEW_SYN_RECV) {
+ struct request_sock *req = inet_reqsk(sk);
+ bool req_stolen = false;
+ struct sock *nsk;
+
+ sk = req->rsk_listener;
+ if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
+ drop_reason = SKB_DROP_REASON_XFRM_POLICY;
+ else
+ drop_reason = tcp_inbound_md5_hash(sk, skb,
+ &hdr->saddr, &hdr->daddr,
+ AF_INET6, dif, sdif);
+ if (drop_reason) {
+ sk_drops_add(sk, skb);
+ reqsk_put(req);
+ goto discard_it;
+ }
+ if (tcp_checksum_complete(skb)) {
+ reqsk_put(req);
+ goto csum_error;
+ }
+ if (unlikely(sk->sk_state != TCP_LISTEN)) {
+ nsk = reuseport_migrate_sock(sk, req_to_sk(req), skb);
+ if (!nsk) {
+ inet_csk_reqsk_queue_drop_and_put(sk, req);
+ goto lookup;
+ }
+ sk = nsk;
+ /* reuseport_migrate_sock() has already held one sk_refcnt
+ * before returning.
+ */
+ } else {
+ sock_hold(sk);
+ }
+ refcounted = true;
+ nsk = NULL;
+ if (!tcp_filter(sk, skb)) {
+ th = (const struct tcphdr *)skb->data;
+ hdr = ipv6_hdr(skb);
+ tcp_v6_fill_cb(skb, hdr, th);
+ nsk = tcp_check_req(sk, skb, req, false, &req_stolen);
+ } else {
+ drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
+ }
+ if (!nsk) {
+ reqsk_put(req);
+ if (req_stolen) {
+ /* Another cpu got exclusive access to req
+ * and created a full blown socket.
+ * Try to feed this packet to this socket
+ * instead of discarding it.
+ */
+ tcp_v6_restore_cb(skb);
+ sock_put(sk);
+ goto lookup;
+ }
+ goto discard_and_relse;
+ }
+ nf_reset_ct(skb);
+ if (nsk == sk) {
+ reqsk_put(req);
+ tcp_v6_restore_cb(skb);
+ } else if (tcp_child_process(sk, nsk, skb)) {
+ tcp_v6_send_reset(nsk, skb);
+ goto discard_and_relse;
+ } else {
+ sock_put(sk);
+ return 0;
+ }
+ }
+
+ if (static_branch_unlikely(&ip6_min_hopcount)) {
+ /* min_hopcount can be changed concurrently from do_ipv6_setsockopt() */
+ if (hdr->hop_limit < READ_ONCE(tcp_inet6_sk(sk)->min_hopcount)) {
+ __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP);
+ goto discard_and_relse;
+ }
+ }
+
+ if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) {
+ drop_reason = SKB_DROP_REASON_XFRM_POLICY;
+ goto discard_and_relse;
+ }
+
+ drop_reason = tcp_inbound_md5_hash(sk, skb, &hdr->saddr, &hdr->daddr,
+ AF_INET6, dif, sdif);
+ if (drop_reason)
+ goto discard_and_relse;
+
+ nf_reset_ct(skb);
+
+ if (tcp_filter(sk, skb)) {
+ drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
+ goto discard_and_relse;
+ }
+ th = (const struct tcphdr *)skb->data;
+ hdr = ipv6_hdr(skb);
+ tcp_v6_fill_cb(skb, hdr, th);
+
+ skb->dev = NULL;
+
+ if (sk->sk_state == TCP_LISTEN) {
+ ret = tcp_v6_do_rcv(sk, skb);
+ goto put_and_return;
+ }
+
+ sk_incoming_cpu_update(sk);
+
+ bh_lock_sock_nested(sk);
+ tcp_segs_in(tcp_sk(sk), skb);
+ ret = 0;
+ if (!sock_owned_by_user(sk)) {
+ ret = tcp_v6_do_rcv(sk, skb);
+ } else {
+ if (tcp_add_backlog(sk, skb, &drop_reason))
+ goto discard_and_relse;
+ }
+ bh_unlock_sock(sk);
+put_and_return:
+ if (refcounted)
+ sock_put(sk);
+ return ret ? -1 : 0;
+
+no_tcp_socket:
+ drop_reason = SKB_DROP_REASON_NO_SOCKET;
+ if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
+ goto discard_it;
+
+ tcp_v6_fill_cb(skb, hdr, th);
+
+ if (tcp_checksum_complete(skb)) {
+csum_error:
+ drop_reason = SKB_DROP_REASON_TCP_CSUM;
+ trace_tcp_bad_csum(skb);
+ __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS);
+bad_packet:
+ __TCP_INC_STATS(net, TCP_MIB_INERRS);
+ } else {
+ tcp_v6_send_reset(NULL, skb);
+ }
+
+discard_it:
+ SKB_DR_OR(drop_reason, NOT_SPECIFIED);
+ kfree_skb_reason(skb, drop_reason);
+ return 0;
+
+discard_and_relse:
+ sk_drops_add(sk, skb);
+ if (refcounted)
+ sock_put(sk);
+ goto discard_it;
+
+do_time_wait:
+ if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+ drop_reason = SKB_DROP_REASON_XFRM_POLICY;
+ inet_twsk_put(inet_twsk(sk));
+ goto discard_it;
+ }
+
+ tcp_v6_fill_cb(skb, hdr, th);
+
+ if (tcp_checksum_complete(skb)) {
+ inet_twsk_put(inet_twsk(sk));
+ goto csum_error;
+ }
+
+ switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
+ case TCP_TW_SYN:
+ {
+ struct sock *sk2;
+
+ sk2 = inet6_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo,
+ skb, __tcp_hdrlen(th),
+ &ipv6_hdr(skb)->saddr, th->source,
+ &ipv6_hdr(skb)->daddr,
+ ntohs(th->dest),
+ tcp_v6_iif_l3_slave(skb),
+ sdif);
+ if (sk2) {
+ struct inet_timewait_sock *tw = inet_twsk(sk);
+ inet_twsk_deschedule_put(tw);
+ sk = sk2;
+ tcp_v6_restore_cb(skb);
+ refcounted = false;
+ goto process;
+ }
+ }
+ /* to ACK */
+ fallthrough;
+ case TCP_TW_ACK:
+ tcp_v6_timewait_ack(sk, skb);
+ break;
+ case TCP_TW_RST:
+ tcp_v6_send_reset(sk, skb);
+ inet_twsk_deschedule_put(inet_twsk(sk));
+ goto discard_it;
+ case TCP_TW_SUCCESS:
+ ;
+ }
+ goto discard_it;
+}
+
+void tcp_v6_early_demux(struct sk_buff *skb)
+{
+ struct net *net = dev_net(skb->dev);
+ const struct ipv6hdr *hdr;
+ const struct tcphdr *th;
+ struct sock *sk;
+
+ if (skb->pkt_type != PACKET_HOST)
+ return;
+
+ if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr)))
+ return;
+
+ hdr = ipv6_hdr(skb);
+ th = tcp_hdr(skb);
+
+ if (th->doff < sizeof(struct tcphdr) / 4)
+ return;
+
+ /* Note : We use inet6_iif() here, not tcp_v6_iif() */
+ sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
+ &hdr->saddr, th->source,
+ &hdr->daddr, ntohs(th->dest),
+ inet6_iif(skb), inet6_sdif(skb));
+ if (sk) {
+ skb->sk = sk;
+ skb->destructor = sock_edemux;
+ if (sk_fullsock(sk)) {
+ struct dst_entry *dst = rcu_dereference(sk->sk_rx_dst);
+
+ if (dst)
+ dst = dst_check(dst, sk->sk_rx_dst_cookie);
+ if (dst &&
+ sk->sk_rx_dst_ifindex == skb->skb_iif)
+ skb_dst_set_noref(skb, dst);
+ }
+ }
+}
+
+static struct timewait_sock_ops tcp6_timewait_sock_ops = {
+ .twsk_obj_size = sizeof(struct tcp6_timewait_sock),
+ .twsk_unique = tcp_twsk_unique,
+ .twsk_destructor = tcp_twsk_destructor,
+};
+
+INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
+{
+ __tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
+}
+
+const struct inet_connection_sock_af_ops ipv6_specific = {
+ .queue_xmit = inet6_csk_xmit,
+ .send_check = tcp_v6_send_check,
+ .rebuild_header = inet6_sk_rebuild_header,
+ .sk_rx_dst_set = inet6_sk_rx_dst_set,
+ .conn_request = tcp_v6_conn_request,
+ .syn_recv_sock = tcp_v6_syn_recv_sock,
+ .net_header_len = sizeof(struct ipv6hdr),
+ .net_frag_header_len = sizeof(struct frag_hdr),
+ .setsockopt = ipv6_setsockopt,
+ .getsockopt = ipv6_getsockopt,
+ .addr2sockaddr = inet6_csk_addr2sockaddr,
+ .sockaddr_len = sizeof(struct sockaddr_in6),
+ .mtu_reduced = tcp_v6_mtu_reduced,
+};
+
+#ifdef CONFIG_TCP_MD5SIG
+static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
+ .md5_lookup = tcp_v6_md5_lookup,
+ .calc_md5_hash = tcp_v6_md5_hash_skb,
+ .md5_parse = tcp_v6_parse_md5_keys,
+};
+#endif
+
+/*
+ * TCP over IPv4 via INET6 API
+ */
+static const struct inet_connection_sock_af_ops ipv6_mapped = {
+ .queue_xmit = ip_queue_xmit,
+ .send_check = tcp_v4_send_check,
+ .rebuild_header = inet_sk_rebuild_header,
+ .sk_rx_dst_set = inet_sk_rx_dst_set,
+ .conn_request = tcp_v6_conn_request,
+ .syn_recv_sock = tcp_v6_syn_recv_sock,
+ .net_header_len = sizeof(struct iphdr),
+ .setsockopt = ipv6_setsockopt,
+ .getsockopt = ipv6_getsockopt,
+ .addr2sockaddr = inet6_csk_addr2sockaddr,
+ .sockaddr_len = sizeof(struct sockaddr_in6),
+ .mtu_reduced = tcp_v4_mtu_reduced,
+};
+
+#ifdef CONFIG_TCP_MD5SIG
+static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = {
+ .md5_lookup = tcp_v4_md5_lookup,
+ .calc_md5_hash = tcp_v4_md5_hash_skb,
+ .md5_parse = tcp_v6_parse_md5_keys,
+};
+#endif
+
+/* NOTE: A lot of things set to zero explicitly by call to
+ * sk_alloc() so need not be done here.
+ */
+static int tcp_v6_init_sock(struct sock *sk)
+{
+ struct inet_connection_sock *icsk = inet_csk(sk);
+
+ tcp_init_sock(sk);
+
+ icsk->icsk_af_ops = &ipv6_specific;
+
+#ifdef CONFIG_TCP_MD5SIG
+ tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific;
+#endif
+
+ return 0;
+}
+
+#ifdef CONFIG_PROC_FS
+/* Proc filesystem TCPv6 sock list dumping. */
+static void get_openreq6(struct seq_file *seq,
+ const struct request_sock *req, int i)
+{
+ long ttd = req->rsk_timer.expires - jiffies;
+ const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr;
+ const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr;
+
+ if (ttd < 0)
+ ttd = 0;
+
+ seq_printf(seq,
+ "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
+ "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n",
+ i,
+ src->s6_addr32[0], src->s6_addr32[1],
+ src->s6_addr32[2], src->s6_addr32[3],
+ inet_rsk(req)->ir_num,
+ dest->s6_addr32[0], dest->s6_addr32[1],
+ dest->s6_addr32[2], dest->s6_addr32[3],
+ ntohs(inet_rsk(req)->ir_rmt_port),
+ TCP_SYN_RECV,
+ 0, 0, /* could print option size, but that is af dependent. */
+ 1, /* timers active (only the expire timer) */
+ jiffies_to_clock_t(ttd),
+ req->num_timeout,
+ from_kuid_munged(seq_user_ns(seq),
+ sock_i_uid(req->rsk_listener)),
+ 0, /* non standard timer */
+ 0, /* open_requests have no inode */
+ 0, req);
+}
+
+static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i)
+{
+ const struct in6_addr *dest, *src;
+ __u16 destp, srcp;
+ int timer_active;
+ unsigned long timer_expires;
+ const struct inet_sock *inet = inet_sk(sp);
+ const struct tcp_sock *tp = tcp_sk(sp);
+ const struct inet_connection_sock *icsk = inet_csk(sp);
+ const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq;
+ int rx_queue;
+ int state;
+
+ dest = &sp->sk_v6_daddr;
+ src = &sp->sk_v6_rcv_saddr;
+ destp = ntohs(inet->inet_dport);
+ srcp = ntohs(inet->inet_sport);
+
+ if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
+ icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
+ icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
+ timer_active = 1;
+ timer_expires = icsk->icsk_timeout;
+ } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
+ timer_active = 4;
+ timer_expires = icsk->icsk_timeout;
+ } else if (timer_pending(&sp->sk_timer)) {
+ timer_active = 2;
+ timer_expires = sp->sk_timer.expires;
+ } else {
+ timer_active = 0;
+ timer_expires = jiffies;
+ }
+
+ state = inet_sk_state_load(sp);
+ if (state == TCP_LISTEN)
+ rx_queue = READ_ONCE(sp->sk_ack_backlog);
+ else
+ /* Because we don't lock the socket,
+ * we might find a transient negative value.
+ */
+ rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) -
+ READ_ONCE(tp->copied_seq), 0);
+
+ seq_printf(seq,
+ "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
+ "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n",
+ i,
+ src->s6_addr32[0], src->s6_addr32[1],
+ src->s6_addr32[2], src->s6_addr32[3], srcp,
+ dest->s6_addr32[0], dest->s6_addr32[1],
+ dest->s6_addr32[2], dest->s6_addr32[3], destp,
+ state,
+ READ_ONCE(tp->write_seq) - tp->snd_una,
+ rx_queue,
+ timer_active,
+ jiffies_delta_to_clock_t(timer_expires - jiffies),
+ icsk->icsk_retransmits,
+ from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)),
+ icsk->icsk_probes_out,
+ sock_i_ino(sp),
+ refcount_read(&sp->sk_refcnt), sp,
+ jiffies_to_clock_t(icsk->icsk_rto),
+ jiffies_to_clock_t(icsk->icsk_ack.ato),
+ (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp),
+ tcp_snd_cwnd(tp),
+ state == TCP_LISTEN ?
+ fastopenq->max_qlen :
+ (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
+ );
+}
+
+static void get_timewait6_sock(struct seq_file *seq,
+ struct inet_timewait_sock *tw, int i)
+{
+ long delta = tw->tw_timer.expires - jiffies;
+ const struct in6_addr *dest, *src;
+ __u16 destp, srcp;
+
+ dest = &tw->tw_v6_daddr;
+ src = &tw->tw_v6_rcv_saddr;
+ destp = ntohs(tw->tw_dport);
+ srcp = ntohs(tw->tw_sport);
+
+ seq_printf(seq,
+ "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X "
+ "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
+ i,
+ src->s6_addr32[0], src->s6_addr32[1],
+ src->s6_addr32[2], src->s6_addr32[3], srcp,
+ dest->s6_addr32[0], dest->s6_addr32[1],
+ dest->s6_addr32[2], dest->s6_addr32[3], destp,
+ tw->tw_substate, 0, 0,
+ 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
+ refcount_read(&tw->tw_refcnt), tw);
+}
+
+static int tcp6_seq_show(struct seq_file *seq, void *v)
+{
+ struct tcp_iter_state *st;
+ struct sock *sk = v;
+
+ if (v == SEQ_START_TOKEN) {
+ seq_puts(seq,
+ " sl "
+ "local_address "
+ "remote_address "
+ "st tx_queue rx_queue tr tm->when retrnsmt"
+ " uid timeout inode\n");
+ goto out;
+ }
+ st = seq->private;
+
+ if (sk->sk_state == TCP_TIME_WAIT)
+ get_timewait6_sock(seq, v, st->num);
+ else if (sk->sk_state == TCP_NEW_SYN_RECV)
+ get_openreq6(seq, v, st->num);
+ else
+ get_tcp6_sock(seq, v, st->num);
+out:
+ return 0;
+}
+
+static const struct seq_operations tcp6_seq_ops = {
+ .show = tcp6_seq_show,
+ .start = tcp_seq_start,
+ .next = tcp_seq_next,
+ .stop = tcp_seq_stop,
+};
+
+static struct tcp_seq_afinfo tcp6_seq_afinfo = {
+ .family = AF_INET6,
+};
+
+int __net_init tcp6_proc_init(struct net *net)
+{
+ if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops,
+ sizeof(struct tcp_iter_state), &tcp6_seq_afinfo))
+ return -ENOMEM;
+ return 0;
+}
+
+void tcp6_proc_exit(struct net *net)
+{
+ remove_proc_entry("tcp6", net->proc_net);
+}
+#endif
+
+struct proto tcpv6_prot = {
+ .name = "TCPv6",
+ .owner = THIS_MODULE,
+ .close = tcp_close,
+ .pre_connect = tcp_v6_pre_connect,
+ .connect = tcp_v6_connect,
+ .disconnect = tcp_disconnect,
+ .accept = inet_csk_accept,
+ .ioctl = tcp_ioctl,
+ .init = tcp_v6_init_sock,
+ .destroy = tcp_v4_destroy_sock,
+ .shutdown = tcp_shutdown,
+ .setsockopt = tcp_setsockopt,
+ .getsockopt = tcp_getsockopt,
+ .bpf_bypass_getsockopt = tcp_bpf_bypass_getsockopt,
+ .keepalive = tcp_set_keepalive,
+ .recvmsg = tcp_recvmsg,
+ .sendmsg = tcp_sendmsg,
+ .splice_eof = tcp_splice_eof,
+ .sendpage = tcp_sendpage,
+ .backlog_rcv = tcp_v6_do_rcv,
+ .release_cb = tcp_release_cb,
+ .hash = inet6_hash,
+ .unhash = inet_unhash,
+ .get_port = inet_csk_get_port,
+ .put_port = inet_put_port,
+#ifdef CONFIG_BPF_SYSCALL
+ .psock_update_sk_prot = tcp_bpf_update_proto,
+#endif
+ .enter_memory_pressure = tcp_enter_memory_pressure,
+ .leave_memory_pressure = tcp_leave_memory_pressure,
+ .stream_memory_free = tcp_stream_memory_free,
+ .sockets_allocated = &tcp_sockets_allocated,
+
+ .memory_allocated = &tcp_memory_allocated,
+ .per_cpu_fw_alloc = &tcp_memory_per_cpu_fw_alloc,
+
+ .memory_pressure = &tcp_memory_pressure,
+ .orphan_count = &tcp_orphan_count,
+ .sysctl_mem = sysctl_tcp_mem,
+ .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem),
+ .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem),
+ .max_header = MAX_TCP_HEADER,
+ .obj_size = sizeof(struct tcp6_sock),
+ .slab_flags = SLAB_TYPESAFE_BY_RCU,
+ .twsk_prot = &tcp6_timewait_sock_ops,
+ .rsk_prot = &tcp6_request_sock_ops,
+ .h.hashinfo = NULL,
+ .no_autobind = true,
+ .diag_destroy = tcp_abort,
+};
+EXPORT_SYMBOL_GPL(tcpv6_prot);
+
+static const struct inet6_protocol tcpv6_protocol = {
+ .handler = tcp_v6_rcv,
+ .err_handler = tcp_v6_err,
+ .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
+};
+
+static struct inet_protosw tcpv6_protosw = {
+ .type = SOCK_STREAM,
+ .protocol = IPPROTO_TCP,
+ .prot = &tcpv6_prot,
+ .ops = &inet6_stream_ops,
+ .flags = INET_PROTOSW_PERMANENT |
+ INET_PROTOSW_ICSK,
+};
+
+static int __net_init tcpv6_net_init(struct net *net)
+{
+ return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6,
+ SOCK_RAW, IPPROTO_TCP, net);
+}
+
+static void __net_exit tcpv6_net_exit(struct net *net)
+{
+ inet_ctl_sock_destroy(net->ipv6.tcp_sk);
+}
+
+static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list)
+{
+ tcp_twsk_purge(net_exit_list, AF_INET6);
+}
+
+static struct pernet_operations tcpv6_net_ops = {
+ .init = tcpv6_net_init,
+ .exit = tcpv6_net_exit,
+ .exit_batch = tcpv6_net_exit_batch,
+};
+
+int __init tcpv6_init(void)
+{
+ int ret;
+
+ ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP);
+ if (ret)
+ goto out;
+
+ /* register inet6 protocol */
+ ret = inet6_register_protosw(&tcpv6_protosw);
+ if (ret)
+ goto out_tcpv6_protocol;
+
+ ret = register_pernet_subsys(&tcpv6_net_ops);
+ if (ret)
+ goto out_tcpv6_protosw;
+
+ ret = mptcpv6_init();
+ if (ret)
+ goto out_tcpv6_pernet_subsys;
+
+out:
+ return ret;
+
+out_tcpv6_pernet_subsys:
+ unregister_pernet_subsys(&tcpv6_net_ops);
+out_tcpv6_protosw:
+ inet6_unregister_protosw(&tcpv6_protosw);
+out_tcpv6_protocol:
+ inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
+ goto out;
+}
+
+void tcpv6_exit(void)
+{
+ unregister_pernet_subsys(&tcpv6_net_ops);
+ inet6_unregister_protosw(&tcpv6_protosw);
+ inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP);
+}