David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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. |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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> |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 42 | #include <linux/indirect_call_wrapper.h> |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 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/busy_poll.h> |
| 62 | |
| 63 | #include <linux/proc_fs.h> |
| 64 | #include <linux/seq_file.h> |
| 65 | |
| 66 | #include <crypto/hash.h> |
| 67 | #include <linux/scatterlist.h> |
| 68 | |
| 69 | #include <trace/events/tcp.h> |
| 70 | |
| 71 | static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb); |
| 72 | static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
| 73 | struct request_sock *req); |
| 74 | |
| 75 | static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb); |
| 76 | |
| 77 | static const struct inet_connection_sock_af_ops ipv6_mapped; |
| 78 | static const struct inet_connection_sock_af_ops ipv6_specific; |
| 79 | #ifdef CONFIG_TCP_MD5SIG |
| 80 | static const struct tcp_sock_af_ops tcp_sock_ipv6_specific; |
| 81 | static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific; |
| 82 | #else |
| 83 | static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, |
| 84 | const struct in6_addr *addr) |
| 85 | { |
| 86 | return NULL; |
| 87 | } |
| 88 | #endif |
| 89 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 90 | /* Helper returning the inet6 address from a given tcp socket. |
| 91 | * It can be used in TCP stack instead of inet6_sk(sk). |
| 92 | * This avoids a dereference and allow compiler optimizations. |
| 93 | * It is a specialized version of inet6_sk_generic(). |
| 94 | */ |
| 95 | static struct ipv6_pinfo *tcp_inet6_sk(const struct sock *sk) |
| 96 | { |
| 97 | unsigned int offset = sizeof(struct tcp6_sock) - sizeof(struct ipv6_pinfo); |
| 98 | |
| 99 | return (struct ipv6_pinfo *)(((u8 *)sk) + offset); |
| 100 | } |
| 101 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 102 | static void inet6_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb) |
| 103 | { |
| 104 | struct dst_entry *dst = skb_dst(skb); |
| 105 | |
| 106 | if (dst && dst_hold_safe(dst)) { |
| 107 | const struct rt6_info *rt = (const struct rt6_info *)dst; |
| 108 | |
| 109 | sk->sk_rx_dst = dst; |
| 110 | inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 111 | tcp_inet6_sk(sk)->rx_dst_cookie = rt6_get_cookie(rt); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 112 | } |
| 113 | } |
| 114 | |
| 115 | static u32 tcp_v6_init_seq(const struct sk_buff *skb) |
| 116 | { |
| 117 | return secure_tcpv6_seq(ipv6_hdr(skb)->daddr.s6_addr32, |
| 118 | ipv6_hdr(skb)->saddr.s6_addr32, |
| 119 | tcp_hdr(skb)->dest, |
| 120 | tcp_hdr(skb)->source); |
| 121 | } |
| 122 | |
| 123 | static u32 tcp_v6_init_ts_off(const struct net *net, const struct sk_buff *skb) |
| 124 | { |
| 125 | return secure_tcpv6_ts_off(net, ipv6_hdr(skb)->daddr.s6_addr32, |
| 126 | ipv6_hdr(skb)->saddr.s6_addr32); |
| 127 | } |
| 128 | |
| 129 | static int tcp_v6_pre_connect(struct sock *sk, struct sockaddr *uaddr, |
| 130 | int addr_len) |
| 131 | { |
| 132 | /* This check is replicated from tcp_v6_connect() and intended to |
| 133 | * prevent BPF program called below from accessing bytes that are out |
| 134 | * of the bound specified by user in addr_len. |
| 135 | */ |
| 136 | if (addr_len < SIN6_LEN_RFC2133) |
| 137 | return -EINVAL; |
| 138 | |
| 139 | sock_owned_by_me(sk); |
| 140 | |
| 141 | return BPF_CGROUP_RUN_PROG_INET6_CONNECT(sk, uaddr); |
| 142 | } |
| 143 | |
| 144 | static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, |
| 145 | int addr_len) |
| 146 | { |
| 147 | struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; |
| 148 | struct inet_sock *inet = inet_sk(sk); |
| 149 | struct inet_connection_sock *icsk = inet_csk(sk); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 150 | struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 151 | struct tcp_sock *tp = tcp_sk(sk); |
| 152 | struct in6_addr *saddr = NULL, *final_p, final; |
| 153 | struct ipv6_txoptions *opt; |
| 154 | struct flowi6 fl6; |
| 155 | struct dst_entry *dst; |
| 156 | int addr_type; |
| 157 | int err; |
| 158 | struct inet_timewait_death_row *tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; |
| 159 | |
| 160 | if (addr_len < SIN6_LEN_RFC2133) |
| 161 | return -EINVAL; |
| 162 | |
| 163 | if (usin->sin6_family != AF_INET6) |
| 164 | return -EAFNOSUPPORT; |
| 165 | |
| 166 | memset(&fl6, 0, sizeof(fl6)); |
| 167 | |
| 168 | if (np->sndflow) { |
| 169 | fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK; |
| 170 | IP6_ECN_flow_init(fl6.flowlabel); |
| 171 | if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { |
| 172 | struct ip6_flowlabel *flowlabel; |
| 173 | flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 174 | if (IS_ERR(flowlabel)) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 175 | return -EINVAL; |
| 176 | fl6_sock_release(flowlabel); |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | /* |
| 181 | * connect() to INADDR_ANY means loopback (BSD'ism). |
| 182 | */ |
| 183 | |
| 184 | if (ipv6_addr_any(&usin->sin6_addr)) { |
| 185 | if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr)) |
| 186 | ipv6_addr_set_v4mapped(htonl(INADDR_LOOPBACK), |
| 187 | &usin->sin6_addr); |
| 188 | else |
| 189 | usin->sin6_addr = in6addr_loopback; |
| 190 | } |
| 191 | |
| 192 | addr_type = ipv6_addr_type(&usin->sin6_addr); |
| 193 | |
| 194 | if (addr_type & IPV6_ADDR_MULTICAST) |
| 195 | return -ENETUNREACH; |
| 196 | |
| 197 | if (addr_type&IPV6_ADDR_LINKLOCAL) { |
| 198 | if (addr_len >= sizeof(struct sockaddr_in6) && |
| 199 | usin->sin6_scope_id) { |
| 200 | /* If interface is set while binding, indices |
| 201 | * must coincide. |
| 202 | */ |
| 203 | if (!sk_dev_equal_l3scope(sk, usin->sin6_scope_id)) |
| 204 | return -EINVAL; |
| 205 | |
| 206 | sk->sk_bound_dev_if = usin->sin6_scope_id; |
| 207 | } |
| 208 | |
| 209 | /* Connect to link-local address requires an interface */ |
| 210 | if (!sk->sk_bound_dev_if) |
| 211 | return -EINVAL; |
| 212 | } |
| 213 | |
| 214 | if (tp->rx_opt.ts_recent_stamp && |
| 215 | !ipv6_addr_equal(&sk->sk_v6_daddr, &usin->sin6_addr)) { |
| 216 | tp->rx_opt.ts_recent = 0; |
| 217 | tp->rx_opt.ts_recent_stamp = 0; |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 218 | WRITE_ONCE(tp->write_seq, 0); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 219 | } |
| 220 | |
| 221 | sk->sk_v6_daddr = usin->sin6_addr; |
| 222 | np->flow_label = fl6.flowlabel; |
| 223 | |
| 224 | /* |
| 225 | * TCP over IPv4 |
| 226 | */ |
| 227 | |
| 228 | if (addr_type & IPV6_ADDR_MAPPED) { |
| 229 | u32 exthdrlen = icsk->icsk_ext_hdr_len; |
| 230 | struct sockaddr_in sin; |
| 231 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 232 | if (__ipv6_only_sock(sk)) |
| 233 | return -ENETUNREACH; |
| 234 | |
| 235 | sin.sin_family = AF_INET; |
| 236 | sin.sin_port = usin->sin6_port; |
| 237 | sin.sin_addr.s_addr = usin->sin6_addr.s6_addr32[3]; |
| 238 | |
| 239 | icsk->icsk_af_ops = &ipv6_mapped; |
| 240 | sk->sk_backlog_rcv = tcp_v4_do_rcv; |
| 241 | #ifdef CONFIG_TCP_MD5SIG |
| 242 | tp->af_specific = &tcp_sock_ipv6_mapped_specific; |
| 243 | #endif |
| 244 | |
| 245 | err = tcp_v4_connect(sk, (struct sockaddr *)&sin, sizeof(sin)); |
| 246 | |
| 247 | if (err) { |
| 248 | icsk->icsk_ext_hdr_len = exthdrlen; |
| 249 | icsk->icsk_af_ops = &ipv6_specific; |
| 250 | sk->sk_backlog_rcv = tcp_v6_do_rcv; |
| 251 | #ifdef CONFIG_TCP_MD5SIG |
| 252 | tp->af_specific = &tcp_sock_ipv6_specific; |
| 253 | #endif |
| 254 | goto failure; |
| 255 | } |
| 256 | np->saddr = sk->sk_v6_rcv_saddr; |
| 257 | |
| 258 | return err; |
| 259 | } |
| 260 | |
| 261 | if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr)) |
| 262 | saddr = &sk->sk_v6_rcv_saddr; |
| 263 | |
| 264 | fl6.flowi6_proto = IPPROTO_TCP; |
| 265 | fl6.daddr = sk->sk_v6_daddr; |
| 266 | fl6.saddr = saddr ? *saddr : np->saddr; |
| 267 | fl6.flowi6_oif = sk->sk_bound_dev_if; |
| 268 | fl6.flowi6_mark = sk->sk_mark; |
| 269 | fl6.fl6_dport = usin->sin6_port; |
| 270 | fl6.fl6_sport = inet->inet_sport; |
| 271 | fl6.flowi6_uid = sk->sk_uid; |
| 272 | |
| 273 | opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk)); |
| 274 | final_p = fl6_update_dst(&fl6, opt, &final); |
| 275 | |
| 276 | security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); |
| 277 | |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame^] | 278 | dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 279 | if (IS_ERR(dst)) { |
| 280 | err = PTR_ERR(dst); |
| 281 | goto failure; |
| 282 | } |
| 283 | |
| 284 | if (!saddr) { |
| 285 | saddr = &fl6.saddr; |
| 286 | sk->sk_v6_rcv_saddr = *saddr; |
| 287 | } |
| 288 | |
| 289 | /* set the source address */ |
| 290 | np->saddr = *saddr; |
| 291 | inet->inet_rcv_saddr = LOOPBACK4_IPV6; |
| 292 | |
| 293 | sk->sk_gso_type = SKB_GSO_TCPV6; |
| 294 | ip6_dst_store(sk, dst, NULL, NULL); |
| 295 | |
| 296 | icsk->icsk_ext_hdr_len = 0; |
| 297 | if (opt) |
| 298 | icsk->icsk_ext_hdr_len = opt->opt_flen + |
| 299 | opt->opt_nflen; |
| 300 | |
| 301 | tp->rx_opt.mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr); |
| 302 | |
| 303 | inet->inet_dport = usin->sin6_port; |
| 304 | |
| 305 | tcp_set_state(sk, TCP_SYN_SENT); |
| 306 | err = inet6_hash_connect(tcp_death_row, sk); |
| 307 | if (err) |
| 308 | goto late_failure; |
| 309 | |
| 310 | sk_set_txhash(sk); |
| 311 | |
| 312 | if (likely(!tp->repair)) { |
| 313 | if (!tp->write_seq) |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 314 | WRITE_ONCE(tp->write_seq, |
| 315 | secure_tcpv6_seq(np->saddr.s6_addr32, |
| 316 | sk->sk_v6_daddr.s6_addr32, |
| 317 | inet->inet_sport, |
| 318 | inet->inet_dport)); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 319 | tp->tsoffset = secure_tcpv6_ts_off(sock_net(sk), |
| 320 | np->saddr.s6_addr32, |
| 321 | sk->sk_v6_daddr.s6_addr32); |
| 322 | } |
| 323 | |
| 324 | if (tcp_fastopen_defer_connect(sk, &err)) |
| 325 | return err; |
| 326 | if (err) |
| 327 | goto late_failure; |
| 328 | |
| 329 | err = tcp_connect(sk); |
| 330 | if (err) |
| 331 | goto late_failure; |
| 332 | |
| 333 | return 0; |
| 334 | |
| 335 | late_failure: |
| 336 | tcp_set_state(sk, TCP_CLOSE); |
| 337 | failure: |
| 338 | inet->inet_dport = 0; |
| 339 | sk->sk_route_caps = 0; |
| 340 | return err; |
| 341 | } |
| 342 | |
| 343 | static void tcp_v6_mtu_reduced(struct sock *sk) |
| 344 | { |
| 345 | struct dst_entry *dst; |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame^] | 346 | u32 mtu; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 347 | |
| 348 | if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) |
| 349 | return; |
| 350 | |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame^] | 351 | mtu = READ_ONCE(tcp_sk(sk)->mtu_info); |
| 352 | |
| 353 | /* Drop requests trying to increase our current mss. |
| 354 | * Check done in __ip6_rt_update_pmtu() is too late. |
| 355 | */ |
| 356 | if (tcp_mtu_to_mss(sk, mtu) >= tcp_sk(sk)->mss_cache) |
| 357 | return; |
| 358 | |
| 359 | dst = inet6_csk_update_pmtu(sk, mtu); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 360 | if (!dst) |
| 361 | return; |
| 362 | |
| 363 | if (inet_csk(sk)->icsk_pmtu_cookie > dst_mtu(dst)) { |
| 364 | tcp_sync_mss(sk, dst_mtu(dst)); |
| 365 | tcp_simple_retransmit(sk); |
| 366 | } |
| 367 | } |
| 368 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 369 | static int tcp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 370 | u8 type, u8 code, int offset, __be32 info) |
| 371 | { |
| 372 | const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data; |
| 373 | const struct tcphdr *th = (struct tcphdr *)(skb->data+offset); |
| 374 | struct net *net = dev_net(skb->dev); |
| 375 | struct request_sock *fastopen; |
| 376 | struct ipv6_pinfo *np; |
| 377 | struct tcp_sock *tp; |
| 378 | __u32 seq, snd_una; |
| 379 | struct sock *sk; |
| 380 | bool fatal; |
| 381 | int err; |
| 382 | |
| 383 | sk = __inet6_lookup_established(net, &tcp_hashinfo, |
| 384 | &hdr->daddr, th->dest, |
| 385 | &hdr->saddr, ntohs(th->source), |
| 386 | skb->dev->ifindex, inet6_sdif(skb)); |
| 387 | |
| 388 | if (!sk) { |
| 389 | __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), |
| 390 | ICMP6_MIB_INERRORS); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 391 | return -ENOENT; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 392 | } |
| 393 | |
| 394 | if (sk->sk_state == TCP_TIME_WAIT) { |
| 395 | inet_twsk_put(inet_twsk(sk)); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 396 | return 0; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 397 | } |
| 398 | seq = ntohl(th->seq); |
| 399 | fatal = icmpv6_err_convert(type, code, &err); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 400 | if (sk->sk_state == TCP_NEW_SYN_RECV) { |
| 401 | tcp_req_err(sk, seq, fatal); |
| 402 | return 0; |
| 403 | } |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 404 | |
| 405 | bh_lock_sock(sk); |
| 406 | if (sock_owned_by_user(sk) && type != ICMPV6_PKT_TOOBIG) |
| 407 | __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |
| 408 | |
| 409 | if (sk->sk_state == TCP_CLOSE) |
| 410 | goto out; |
| 411 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 412 | if (ipv6_hdr(skb)->hop_limit < tcp_inet6_sk(sk)->min_hopcount) { |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 413 | __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
| 414 | goto out; |
| 415 | } |
| 416 | |
| 417 | tp = tcp_sk(sk); |
| 418 | /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 419 | fastopen = rcu_dereference(tp->fastopen_rsk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 420 | snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una; |
| 421 | if (sk->sk_state != TCP_LISTEN && |
| 422 | !between(seq, snd_una, tp->snd_nxt)) { |
| 423 | __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
| 424 | goto out; |
| 425 | } |
| 426 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 427 | np = tcp_inet6_sk(sk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 428 | |
| 429 | if (type == NDISC_REDIRECT) { |
| 430 | if (!sock_owned_by_user(sk)) { |
| 431 | struct dst_entry *dst = __sk_dst_check(sk, np->dst_cookie); |
| 432 | |
| 433 | if (dst) |
| 434 | dst->ops->redirect(dst, sk, skb); |
| 435 | } |
| 436 | goto out; |
| 437 | } |
| 438 | |
| 439 | if (type == ICMPV6_PKT_TOOBIG) { |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame^] | 440 | u32 mtu = ntohl(info); |
| 441 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 442 | /* We are not interested in TCP_LISTEN and open_requests |
| 443 | * (SYN-ACKs send out by Linux are always <576bytes so |
| 444 | * they should go through unfragmented). |
| 445 | */ |
| 446 | if (sk->sk_state == TCP_LISTEN) |
| 447 | goto out; |
| 448 | |
| 449 | if (!ip6_sk_accept_pmtu(sk)) |
| 450 | goto out; |
| 451 | |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame^] | 452 | if (mtu < IPV6_MIN_MTU) |
| 453 | goto out; |
| 454 | |
| 455 | WRITE_ONCE(tp->mtu_info, mtu); |
| 456 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 457 | if (!sock_owned_by_user(sk)) |
| 458 | tcp_v6_mtu_reduced(sk); |
| 459 | else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, |
| 460 | &sk->sk_tsq_flags)) |
| 461 | sock_hold(sk); |
| 462 | goto out; |
| 463 | } |
| 464 | |
| 465 | |
| 466 | /* Might be for an request_sock */ |
| 467 | switch (sk->sk_state) { |
| 468 | case TCP_SYN_SENT: |
| 469 | case TCP_SYN_RECV: |
| 470 | /* Only in fast or simultaneous open. If a fast open socket is |
| 471 | * is already accepted it is treated as a connected one below. |
| 472 | */ |
| 473 | if (fastopen && !fastopen->sk) |
| 474 | break; |
| 475 | |
| 476 | if (!sock_owned_by_user(sk)) { |
| 477 | sk->sk_err = err; |
| 478 | sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */ |
| 479 | |
| 480 | tcp_done(sk); |
| 481 | } else |
| 482 | sk->sk_err_soft = err; |
| 483 | goto out; |
| 484 | } |
| 485 | |
| 486 | if (!sock_owned_by_user(sk) && np->recverr) { |
| 487 | sk->sk_err = err; |
| 488 | sk->sk_error_report(sk); |
| 489 | } else |
| 490 | sk->sk_err_soft = err; |
| 491 | |
| 492 | out: |
| 493 | bh_unlock_sock(sk); |
| 494 | sock_put(sk); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 495 | return 0; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 496 | } |
| 497 | |
| 498 | |
| 499 | static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, |
| 500 | struct flowi *fl, |
| 501 | struct request_sock *req, |
| 502 | struct tcp_fastopen_cookie *foc, |
| 503 | enum tcp_synack_type synack_type) |
| 504 | { |
| 505 | struct inet_request_sock *ireq = inet_rsk(req); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 506 | struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 507 | struct ipv6_txoptions *opt; |
| 508 | struct flowi6 *fl6 = &fl->u.ip6; |
| 509 | struct sk_buff *skb; |
| 510 | int err = -ENOMEM; |
| 511 | |
| 512 | /* First, grab a route. */ |
| 513 | if (!dst && (dst = inet6_csk_route_req(sk, fl6, req, |
| 514 | IPPROTO_TCP)) == NULL) |
| 515 | goto done; |
| 516 | |
| 517 | skb = tcp_make_synack(sk, dst, req, foc, synack_type); |
| 518 | |
| 519 | if (skb) { |
| 520 | __tcp_v6_send_check(skb, &ireq->ir_v6_loc_addr, |
| 521 | &ireq->ir_v6_rmt_addr); |
| 522 | |
| 523 | fl6->daddr = ireq->ir_v6_rmt_addr; |
| 524 | if (np->repflow && ireq->pktopts) |
| 525 | fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts)); |
| 526 | |
| 527 | rcu_read_lock(); |
| 528 | opt = ireq->ipv6_opt; |
| 529 | if (!opt) |
| 530 | opt = rcu_dereference(np->opt); |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame^] | 531 | err = ip6_xmit(sk, skb, fl6, skb->mark ? : sk->sk_mark, opt, |
| 532 | np->tclass, sk->sk_priority); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 533 | rcu_read_unlock(); |
| 534 | err = net_xmit_eval(err); |
| 535 | } |
| 536 | |
| 537 | done: |
| 538 | return err; |
| 539 | } |
| 540 | |
| 541 | |
| 542 | static void tcp_v6_reqsk_destructor(struct request_sock *req) |
| 543 | { |
| 544 | kfree(inet_rsk(req)->ipv6_opt); |
| 545 | kfree_skb(inet_rsk(req)->pktopts); |
| 546 | } |
| 547 | |
| 548 | #ifdef CONFIG_TCP_MD5SIG |
| 549 | static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(const struct sock *sk, |
| 550 | const struct in6_addr *addr) |
| 551 | { |
| 552 | return tcp_md5_do_lookup(sk, (union tcp_md5_addr *)addr, AF_INET6); |
| 553 | } |
| 554 | |
| 555 | static struct tcp_md5sig_key *tcp_v6_md5_lookup(const struct sock *sk, |
| 556 | const struct sock *addr_sk) |
| 557 | { |
| 558 | return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr); |
| 559 | } |
| 560 | |
| 561 | static int tcp_v6_parse_md5_keys(struct sock *sk, int optname, |
| 562 | char __user *optval, int optlen) |
| 563 | { |
| 564 | struct tcp_md5sig cmd; |
| 565 | struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&cmd.tcpm_addr; |
| 566 | u8 prefixlen; |
| 567 | |
| 568 | if (optlen < sizeof(cmd)) |
| 569 | return -EINVAL; |
| 570 | |
| 571 | if (copy_from_user(&cmd, optval, sizeof(cmd))) |
| 572 | return -EFAULT; |
| 573 | |
| 574 | if (sin6->sin6_family != AF_INET6) |
| 575 | return -EINVAL; |
| 576 | |
| 577 | if (optname == TCP_MD5SIG_EXT && |
| 578 | cmd.tcpm_flags & TCP_MD5SIG_FLAG_PREFIX) { |
| 579 | prefixlen = cmd.tcpm_prefixlen; |
| 580 | if (prefixlen > 128 || (ipv6_addr_v4mapped(&sin6->sin6_addr) && |
| 581 | prefixlen > 32)) |
| 582 | return -EINVAL; |
| 583 | } else { |
| 584 | prefixlen = ipv6_addr_v4mapped(&sin6->sin6_addr) ? 32 : 128; |
| 585 | } |
| 586 | |
| 587 | if (!cmd.tcpm_keylen) { |
| 588 | if (ipv6_addr_v4mapped(&sin6->sin6_addr)) |
| 589 | return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], |
| 590 | AF_INET, prefixlen); |
| 591 | return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin6->sin6_addr, |
| 592 | AF_INET6, prefixlen); |
| 593 | } |
| 594 | |
| 595 | if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) |
| 596 | return -EINVAL; |
| 597 | |
| 598 | if (ipv6_addr_v4mapped(&sin6->sin6_addr)) |
| 599 | return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr.s6_addr32[3], |
| 600 | AF_INET, prefixlen, cmd.tcpm_key, |
| 601 | cmd.tcpm_keylen, GFP_KERNEL); |
| 602 | |
| 603 | return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin6->sin6_addr, |
| 604 | AF_INET6, prefixlen, cmd.tcpm_key, |
| 605 | cmd.tcpm_keylen, GFP_KERNEL); |
| 606 | } |
| 607 | |
| 608 | static int tcp_v6_md5_hash_headers(struct tcp_md5sig_pool *hp, |
| 609 | const struct in6_addr *daddr, |
| 610 | const struct in6_addr *saddr, |
| 611 | const struct tcphdr *th, int nbytes) |
| 612 | { |
| 613 | struct tcp6_pseudohdr *bp; |
| 614 | struct scatterlist sg; |
| 615 | struct tcphdr *_th; |
| 616 | |
| 617 | bp = hp->scratch; |
| 618 | /* 1. TCP pseudo-header (RFC2460) */ |
| 619 | bp->saddr = *saddr; |
| 620 | bp->daddr = *daddr; |
| 621 | bp->protocol = cpu_to_be32(IPPROTO_TCP); |
| 622 | bp->len = cpu_to_be32(nbytes); |
| 623 | |
| 624 | _th = (struct tcphdr *)(bp + 1); |
| 625 | memcpy(_th, th, sizeof(*th)); |
| 626 | _th->check = 0; |
| 627 | |
| 628 | sg_init_one(&sg, bp, sizeof(*bp) + sizeof(*th)); |
| 629 | ahash_request_set_crypt(hp->md5_req, &sg, NULL, |
| 630 | sizeof(*bp) + sizeof(*th)); |
| 631 | return crypto_ahash_update(hp->md5_req); |
| 632 | } |
| 633 | |
| 634 | static int tcp_v6_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
| 635 | const struct in6_addr *daddr, struct in6_addr *saddr, |
| 636 | const struct tcphdr *th) |
| 637 | { |
| 638 | struct tcp_md5sig_pool *hp; |
| 639 | struct ahash_request *req; |
| 640 | |
| 641 | hp = tcp_get_md5sig_pool(); |
| 642 | if (!hp) |
| 643 | goto clear_hash_noput; |
| 644 | req = hp->md5_req; |
| 645 | |
| 646 | if (crypto_ahash_init(req)) |
| 647 | goto clear_hash; |
| 648 | if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, th->doff << 2)) |
| 649 | goto clear_hash; |
| 650 | if (tcp_md5_hash_key(hp, key)) |
| 651 | goto clear_hash; |
| 652 | ahash_request_set_crypt(req, NULL, md5_hash, 0); |
| 653 | if (crypto_ahash_final(req)) |
| 654 | goto clear_hash; |
| 655 | |
| 656 | tcp_put_md5sig_pool(); |
| 657 | return 0; |
| 658 | |
| 659 | clear_hash: |
| 660 | tcp_put_md5sig_pool(); |
| 661 | clear_hash_noput: |
| 662 | memset(md5_hash, 0, 16); |
| 663 | return 1; |
| 664 | } |
| 665 | |
| 666 | static int tcp_v6_md5_hash_skb(char *md5_hash, |
| 667 | const struct tcp_md5sig_key *key, |
| 668 | const struct sock *sk, |
| 669 | const struct sk_buff *skb) |
| 670 | { |
| 671 | const struct in6_addr *saddr, *daddr; |
| 672 | struct tcp_md5sig_pool *hp; |
| 673 | struct ahash_request *req; |
| 674 | const struct tcphdr *th = tcp_hdr(skb); |
| 675 | |
| 676 | if (sk) { /* valid for establish/request sockets */ |
| 677 | saddr = &sk->sk_v6_rcv_saddr; |
| 678 | daddr = &sk->sk_v6_daddr; |
| 679 | } else { |
| 680 | const struct ipv6hdr *ip6h = ipv6_hdr(skb); |
| 681 | saddr = &ip6h->saddr; |
| 682 | daddr = &ip6h->daddr; |
| 683 | } |
| 684 | |
| 685 | hp = tcp_get_md5sig_pool(); |
| 686 | if (!hp) |
| 687 | goto clear_hash_noput; |
| 688 | req = hp->md5_req; |
| 689 | |
| 690 | if (crypto_ahash_init(req)) |
| 691 | goto clear_hash; |
| 692 | |
| 693 | if (tcp_v6_md5_hash_headers(hp, daddr, saddr, th, skb->len)) |
| 694 | goto clear_hash; |
| 695 | if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) |
| 696 | goto clear_hash; |
| 697 | if (tcp_md5_hash_key(hp, key)) |
| 698 | goto clear_hash; |
| 699 | ahash_request_set_crypt(req, NULL, md5_hash, 0); |
| 700 | if (crypto_ahash_final(req)) |
| 701 | goto clear_hash; |
| 702 | |
| 703 | tcp_put_md5sig_pool(); |
| 704 | return 0; |
| 705 | |
| 706 | clear_hash: |
| 707 | tcp_put_md5sig_pool(); |
| 708 | clear_hash_noput: |
| 709 | memset(md5_hash, 0, 16); |
| 710 | return 1; |
| 711 | } |
| 712 | |
| 713 | #endif |
| 714 | |
| 715 | static bool tcp_v6_inbound_md5_hash(const struct sock *sk, |
| 716 | const struct sk_buff *skb) |
| 717 | { |
| 718 | #ifdef CONFIG_TCP_MD5SIG |
| 719 | const __u8 *hash_location = NULL; |
| 720 | struct tcp_md5sig_key *hash_expected; |
| 721 | const struct ipv6hdr *ip6h = ipv6_hdr(skb); |
| 722 | const struct tcphdr *th = tcp_hdr(skb); |
| 723 | int genhash; |
| 724 | u8 newhash[16]; |
| 725 | |
| 726 | hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr); |
| 727 | hash_location = tcp_parse_md5sig_option(th); |
| 728 | |
| 729 | /* We've parsed the options - do we have a hash? */ |
| 730 | if (!hash_expected && !hash_location) |
| 731 | return false; |
| 732 | |
| 733 | if (hash_expected && !hash_location) { |
| 734 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); |
| 735 | return true; |
| 736 | } |
| 737 | |
| 738 | if (!hash_expected && hash_location) { |
| 739 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); |
| 740 | return true; |
| 741 | } |
| 742 | |
| 743 | /* check the signature */ |
| 744 | genhash = tcp_v6_md5_hash_skb(newhash, |
| 745 | hash_expected, |
| 746 | NULL, skb); |
| 747 | |
| 748 | if (genhash || memcmp(hash_location, newhash, 16) != 0) { |
| 749 | NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMD5FAILURE); |
| 750 | net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n", |
| 751 | genhash ? "failed" : "mismatch", |
| 752 | &ip6h->saddr, ntohs(th->source), |
| 753 | &ip6h->daddr, ntohs(th->dest)); |
| 754 | return true; |
| 755 | } |
| 756 | #endif |
| 757 | return false; |
| 758 | } |
| 759 | |
| 760 | static void tcp_v6_init_req(struct request_sock *req, |
| 761 | const struct sock *sk_listener, |
| 762 | struct sk_buff *skb) |
| 763 | { |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 764 | bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 765 | struct inet_request_sock *ireq = inet_rsk(req); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 766 | const struct ipv6_pinfo *np = tcp_inet6_sk(sk_listener); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 767 | |
| 768 | ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr; |
| 769 | ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr; |
| 770 | |
| 771 | /* So that link locals have meaning */ |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 772 | if ((!sk_listener->sk_bound_dev_if || l3_slave) && |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 773 | ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) |
| 774 | ireq->ir_iif = tcp_v6_iif(skb); |
| 775 | |
| 776 | if (!TCP_SKB_CB(skb)->tcp_tw_isn && |
| 777 | (ipv6_opt_accepted(sk_listener, skb, &TCP_SKB_CB(skb)->header.h6) || |
| 778 | np->rxopt.bits.rxinfo || |
| 779 | np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim || |
| 780 | np->rxopt.bits.rxohlim || np->repflow)) { |
| 781 | refcount_inc(&skb->users); |
| 782 | ireq->pktopts = skb; |
| 783 | } |
| 784 | } |
| 785 | |
| 786 | static struct dst_entry *tcp_v6_route_req(const struct sock *sk, |
| 787 | struct flowi *fl, |
| 788 | const struct request_sock *req) |
| 789 | { |
| 790 | return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP); |
| 791 | } |
| 792 | |
| 793 | struct request_sock_ops tcp6_request_sock_ops __read_mostly = { |
| 794 | .family = AF_INET6, |
| 795 | .obj_size = sizeof(struct tcp6_request_sock), |
| 796 | .rtx_syn_ack = tcp_rtx_synack, |
| 797 | .send_ack = tcp_v6_reqsk_send_ack, |
| 798 | .destructor = tcp_v6_reqsk_destructor, |
| 799 | .send_reset = tcp_v6_send_reset, |
| 800 | .syn_ack_timeout = tcp_syn_ack_timeout, |
| 801 | }; |
| 802 | |
| 803 | static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = { |
| 804 | .mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - |
| 805 | sizeof(struct ipv6hdr), |
| 806 | #ifdef CONFIG_TCP_MD5SIG |
| 807 | .req_md5_lookup = tcp_v6_md5_lookup, |
| 808 | .calc_md5_hash = tcp_v6_md5_hash_skb, |
| 809 | #endif |
| 810 | .init_req = tcp_v6_init_req, |
| 811 | #ifdef CONFIG_SYN_COOKIES |
| 812 | .cookie_init_seq = cookie_v6_init_sequence, |
| 813 | #endif |
| 814 | .route_req = tcp_v6_route_req, |
| 815 | .init_seq = tcp_v6_init_seq, |
| 816 | .init_ts_off = tcp_v6_init_ts_off, |
| 817 | .send_synack = tcp_v6_send_synack, |
| 818 | }; |
| 819 | |
| 820 | static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 seq, |
| 821 | u32 ack, u32 win, u32 tsval, u32 tsecr, |
| 822 | int oif, struct tcp_md5sig_key *key, int rst, |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 823 | u8 tclass, __be32 label, u32 priority) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 824 | { |
| 825 | const struct tcphdr *th = tcp_hdr(skb); |
| 826 | struct tcphdr *t1; |
| 827 | struct sk_buff *buff; |
| 828 | struct flowi6 fl6; |
| 829 | struct net *net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); |
| 830 | struct sock *ctl_sk = net->ipv6.tcp_sk; |
| 831 | unsigned int tot_len = sizeof(struct tcphdr); |
| 832 | struct dst_entry *dst; |
| 833 | __be32 *topt; |
| 834 | __u32 mark = 0; |
| 835 | |
| 836 | if (tsecr) |
| 837 | tot_len += TCPOLEN_TSTAMP_ALIGNED; |
| 838 | #ifdef CONFIG_TCP_MD5SIG |
| 839 | if (key) |
| 840 | tot_len += TCPOLEN_MD5SIG_ALIGNED; |
| 841 | #endif |
| 842 | |
| 843 | buff = alloc_skb(MAX_HEADER + sizeof(struct ipv6hdr) + tot_len, |
| 844 | GFP_ATOMIC); |
| 845 | if (!buff) |
| 846 | return; |
| 847 | |
| 848 | skb_reserve(buff, MAX_HEADER + sizeof(struct ipv6hdr) + tot_len); |
| 849 | |
| 850 | t1 = skb_push(buff, tot_len); |
| 851 | skb_reset_transport_header(buff); |
| 852 | |
| 853 | /* Swap the send and the receive. */ |
| 854 | memset(t1, 0, sizeof(*t1)); |
| 855 | t1->dest = th->source; |
| 856 | t1->source = th->dest; |
| 857 | t1->doff = tot_len / 4; |
| 858 | t1->seq = htonl(seq); |
| 859 | t1->ack_seq = htonl(ack); |
| 860 | t1->ack = !rst || !th->ack; |
| 861 | t1->rst = rst; |
| 862 | t1->window = htons(win); |
| 863 | |
| 864 | topt = (__be32 *)(t1 + 1); |
| 865 | |
| 866 | if (tsecr) { |
| 867 | *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
| 868 | (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); |
| 869 | *topt++ = htonl(tsval); |
| 870 | *topt++ = htonl(tsecr); |
| 871 | } |
| 872 | |
| 873 | #ifdef CONFIG_TCP_MD5SIG |
| 874 | if (key) { |
| 875 | *topt++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
| 876 | (TCPOPT_MD5SIG << 8) | TCPOLEN_MD5SIG); |
| 877 | tcp_v6_md5_hash_hdr((__u8 *)topt, key, |
| 878 | &ipv6_hdr(skb)->saddr, |
| 879 | &ipv6_hdr(skb)->daddr, t1); |
| 880 | } |
| 881 | #endif |
| 882 | |
| 883 | memset(&fl6, 0, sizeof(fl6)); |
| 884 | fl6.daddr = ipv6_hdr(skb)->saddr; |
| 885 | fl6.saddr = ipv6_hdr(skb)->daddr; |
| 886 | fl6.flowlabel = label; |
| 887 | |
| 888 | buff->ip_summed = CHECKSUM_PARTIAL; |
| 889 | buff->csum = 0; |
| 890 | |
| 891 | __tcp_v6_send_check(buff, &fl6.saddr, &fl6.daddr); |
| 892 | |
| 893 | fl6.flowi6_proto = IPPROTO_TCP; |
| 894 | if (rt6_need_strict(&fl6.daddr) && !oif) |
| 895 | fl6.flowi6_oif = tcp_v6_iif(skb); |
| 896 | else { |
| 897 | if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) |
| 898 | oif = skb->skb_iif; |
| 899 | |
| 900 | fl6.flowi6_oif = oif; |
| 901 | } |
| 902 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 903 | if (sk) { |
| 904 | if (sk->sk_state == TCP_TIME_WAIT) { |
| 905 | mark = inet_twsk(sk)->tw_mark; |
| 906 | /* autoflowlabel relies on buff->hash */ |
| 907 | skb_set_hash(buff, inet_twsk(sk)->tw_txhash, |
| 908 | PKT_HASH_TYPE_L4); |
| 909 | } else { |
| 910 | mark = sk->sk_mark; |
| 911 | } |
| 912 | buff->tstamp = tcp_transmit_time(sk); |
| 913 | } |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 914 | fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark) ?: mark; |
| 915 | fl6.fl6_dport = t1->dest; |
| 916 | fl6.fl6_sport = t1->source; |
| 917 | fl6.flowi6_uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); |
| 918 | security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
| 919 | |
| 920 | /* Pass a socket to ip6_dst_lookup either it is for RST |
| 921 | * Underlying function will use this to retrieve the network |
| 922 | * namespace |
| 923 | */ |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame^] | 924 | dst = ip6_dst_lookup_flow(sock_net(ctl_sk), ctl_sk, &fl6, NULL); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 925 | if (!IS_ERR(dst)) { |
| 926 | skb_dst_set(buff, dst); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 927 | ip6_xmit(ctl_sk, buff, &fl6, fl6.flowi6_mark, NULL, tclass, |
| 928 | priority); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 929 | TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
| 930 | if (rst) |
| 931 | TCP_INC_STATS(net, TCP_MIB_OUTRSTS); |
| 932 | return; |
| 933 | } |
| 934 | |
| 935 | kfree_skb(buff); |
| 936 | } |
| 937 | |
| 938 | static void tcp_v6_send_reset(const struct sock *sk, struct sk_buff *skb) |
| 939 | { |
| 940 | const struct tcphdr *th = tcp_hdr(skb); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 941 | struct ipv6hdr *ipv6h = ipv6_hdr(skb); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 942 | u32 seq = 0, ack_seq = 0; |
| 943 | struct tcp_md5sig_key *key = NULL; |
| 944 | #ifdef CONFIG_TCP_MD5SIG |
| 945 | const __u8 *hash_location = NULL; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 946 | unsigned char newhash[16]; |
| 947 | int genhash; |
| 948 | struct sock *sk1 = NULL; |
| 949 | #endif |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 950 | __be32 label = 0; |
| 951 | u32 priority = 0; |
| 952 | struct net *net; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 953 | int oif = 0; |
| 954 | |
| 955 | if (th->rst) |
| 956 | return; |
| 957 | |
| 958 | /* If sk not NULL, it means we did a successful lookup and incoming |
| 959 | * route had to be correct. prequeue might have dropped our dst. |
| 960 | */ |
| 961 | if (!sk && !ipv6_unicast_destination(skb)) |
| 962 | return; |
| 963 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 964 | net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 965 | #ifdef CONFIG_TCP_MD5SIG |
| 966 | rcu_read_lock(); |
| 967 | hash_location = tcp_parse_md5sig_option(th); |
| 968 | if (sk && sk_fullsock(sk)) { |
| 969 | key = tcp_v6_md5_do_lookup(sk, &ipv6h->saddr); |
| 970 | } else if (hash_location) { |
| 971 | /* |
| 972 | * active side is lost. Try to find listening socket through |
| 973 | * source port, and then find md5 key through listening socket. |
| 974 | * we are not loose security here: |
| 975 | * Incoming packet is checked with md5 hash with finding key, |
| 976 | * no RST generated if md5 hash doesn't match. |
| 977 | */ |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 978 | sk1 = inet6_lookup_listener(net, |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 979 | &tcp_hashinfo, NULL, 0, |
| 980 | &ipv6h->saddr, |
| 981 | th->source, &ipv6h->daddr, |
| 982 | ntohs(th->source), |
| 983 | tcp_v6_iif_l3_slave(skb), |
| 984 | tcp_v6_sdif(skb)); |
| 985 | if (!sk1) |
| 986 | goto out; |
| 987 | |
| 988 | key = tcp_v6_md5_do_lookup(sk1, &ipv6h->saddr); |
| 989 | if (!key) |
| 990 | goto out; |
| 991 | |
| 992 | genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb); |
| 993 | if (genhash || memcmp(hash_location, newhash, 16) != 0) |
| 994 | goto out; |
| 995 | } |
| 996 | #endif |
| 997 | |
| 998 | if (th->ack) |
| 999 | seq = ntohl(th->ack_seq); |
| 1000 | else |
| 1001 | ack_seq = ntohl(th->seq) + th->syn + th->fin + skb->len - |
| 1002 | (th->doff << 2); |
| 1003 | |
| 1004 | if (sk) { |
| 1005 | oif = sk->sk_bound_dev_if; |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1006 | if (sk_fullsock(sk)) { |
| 1007 | const struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
| 1008 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1009 | trace_tcp_send_reset(sk, skb); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1010 | if (np->repflow) |
| 1011 | label = ip6_flowlabel(ipv6h); |
| 1012 | priority = sk->sk_priority; |
| 1013 | } |
| 1014 | if (sk->sk_state == TCP_TIME_WAIT) { |
| 1015 | label = cpu_to_be32(inet_twsk(sk)->tw_flowlabel); |
| 1016 | priority = inet_twsk(sk)->tw_priority; |
| 1017 | } |
| 1018 | } else { |
| 1019 | if (net->ipv6.sysctl.flowlabel_reflect & FLOWLABEL_REFLECT_TCP_RESET) |
| 1020 | label = ip6_flowlabel(ipv6h); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1021 | } |
| 1022 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1023 | tcp_v6_send_response(sk, skb, seq, ack_seq, 0, 0, 0, oif, key, 1, 0, |
| 1024 | label, priority); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1025 | |
| 1026 | #ifdef CONFIG_TCP_MD5SIG |
| 1027 | out: |
| 1028 | rcu_read_unlock(); |
| 1029 | #endif |
| 1030 | } |
| 1031 | |
| 1032 | static void tcp_v6_send_ack(const struct sock *sk, struct sk_buff *skb, u32 seq, |
| 1033 | u32 ack, u32 win, u32 tsval, u32 tsecr, int oif, |
| 1034 | struct tcp_md5sig_key *key, u8 tclass, |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1035 | __be32 label, u32 priority) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1036 | { |
| 1037 | tcp_v6_send_response(sk, skb, seq, ack, win, tsval, tsecr, oif, key, 0, |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1038 | tclass, label, priority); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1039 | } |
| 1040 | |
| 1041 | static void tcp_v6_timewait_ack(struct sock *sk, struct sk_buff *skb) |
| 1042 | { |
| 1043 | struct inet_timewait_sock *tw = inet_twsk(sk); |
| 1044 | struct tcp_timewait_sock *tcptw = tcp_twsk(sk); |
| 1045 | |
| 1046 | tcp_v6_send_ack(sk, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
| 1047 | tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
| 1048 | tcp_time_stamp_raw() + tcptw->tw_ts_offset, |
| 1049 | tcptw->tw_ts_recent, tw->tw_bound_dev_if, tcp_twsk_md5_key(tcptw), |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1050 | tw->tw_tclass, cpu_to_be32(tw->tw_flowlabel), tw->tw_priority); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1051 | |
| 1052 | inet_twsk_put(tw); |
| 1053 | } |
| 1054 | |
| 1055 | static void tcp_v6_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
| 1056 | struct request_sock *req) |
| 1057 | { |
| 1058 | /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV |
| 1059 | * sk->sk_state == TCP_SYN_RECV -> for Fast Open. |
| 1060 | */ |
| 1061 | /* RFC 7323 2.3 |
| 1062 | * The window field (SEG.WND) of every outgoing segment, with the |
| 1063 | * exception of <SYN> segments, MUST be right-shifted by |
| 1064 | * Rcv.Wind.Shift bits: |
| 1065 | */ |
| 1066 | tcp_v6_send_ack(sk, skb, (sk->sk_state == TCP_LISTEN) ? |
| 1067 | tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt, |
| 1068 | tcp_rsk(req)->rcv_nxt, |
| 1069 | req->rsk_rcv_wnd >> inet_rsk(req)->rcv_wscale, |
| 1070 | tcp_time_stamp_raw() + tcp_rsk(req)->ts_off, |
| 1071 | req->ts_recent, sk->sk_bound_dev_if, |
| 1072 | tcp_v6_md5_do_lookup(sk, &ipv6_hdr(skb)->saddr), |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1073 | 0, 0, sk->sk_priority); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1074 | } |
| 1075 | |
| 1076 | |
| 1077 | static struct sock *tcp_v6_cookie_check(struct sock *sk, struct sk_buff *skb) |
| 1078 | { |
| 1079 | #ifdef CONFIG_SYN_COOKIES |
| 1080 | const struct tcphdr *th = tcp_hdr(skb); |
| 1081 | |
| 1082 | if (!th->syn) |
| 1083 | sk = cookie_v6_check(sk, skb); |
| 1084 | #endif |
| 1085 | return sk; |
| 1086 | } |
| 1087 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1088 | u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, |
| 1089 | struct tcphdr *th, u32 *cookie) |
| 1090 | { |
| 1091 | u16 mss = 0; |
| 1092 | #ifdef CONFIG_SYN_COOKIES |
| 1093 | mss = tcp_get_syncookie_mss(&tcp6_request_sock_ops, |
| 1094 | &tcp_request_sock_ipv6_ops, sk, th); |
| 1095 | if (mss) { |
| 1096 | *cookie = __cookie_v6_init_sequence(iph, th, &mss); |
| 1097 | tcp_synq_overflow(sk); |
| 1098 | } |
| 1099 | #endif |
| 1100 | return mss; |
| 1101 | } |
| 1102 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1103 | static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb) |
| 1104 | { |
| 1105 | if (skb->protocol == htons(ETH_P_IP)) |
| 1106 | return tcp_v4_conn_request(sk, skb); |
| 1107 | |
| 1108 | if (!ipv6_unicast_destination(skb)) |
| 1109 | goto drop; |
| 1110 | |
Olivier Deprez | 0e64123 | 2021-09-23 10:07:05 +0200 | [diff] [blame^] | 1111 | if (ipv6_addr_v4mapped(&ipv6_hdr(skb)->saddr)) { |
| 1112 | __IP6_INC_STATS(sock_net(sk), NULL, IPSTATS_MIB_INHDRERRORS); |
| 1113 | return 0; |
| 1114 | } |
| 1115 | |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1116 | return tcp_conn_request(&tcp6_request_sock_ops, |
| 1117 | &tcp_request_sock_ipv6_ops, sk, skb); |
| 1118 | |
| 1119 | drop: |
| 1120 | tcp_listendrop(sk); |
| 1121 | return 0; /* don't send reset */ |
| 1122 | } |
| 1123 | |
| 1124 | static void tcp_v6_restore_cb(struct sk_buff *skb) |
| 1125 | { |
| 1126 | /* We need to move header back to the beginning if xfrm6_policy_check() |
| 1127 | * and tcp_v6_fill_cb() are going to be called again. |
| 1128 | * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there. |
| 1129 | */ |
| 1130 | memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6, |
| 1131 | sizeof(struct inet6_skb_parm)); |
| 1132 | } |
| 1133 | |
| 1134 | static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
| 1135 | struct request_sock *req, |
| 1136 | struct dst_entry *dst, |
| 1137 | struct request_sock *req_unhash, |
| 1138 | bool *own_req) |
| 1139 | { |
| 1140 | struct inet_request_sock *ireq; |
| 1141 | struct ipv6_pinfo *newnp; |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1142 | const struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1143 | struct ipv6_txoptions *opt; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1144 | struct inet_sock *newinet; |
| 1145 | struct tcp_sock *newtp; |
| 1146 | struct sock *newsk; |
| 1147 | #ifdef CONFIG_TCP_MD5SIG |
| 1148 | struct tcp_md5sig_key *key; |
| 1149 | #endif |
| 1150 | struct flowi6 fl6; |
| 1151 | |
| 1152 | if (skb->protocol == htons(ETH_P_IP)) { |
| 1153 | /* |
| 1154 | * v6 mapped |
| 1155 | */ |
| 1156 | |
| 1157 | newsk = tcp_v4_syn_recv_sock(sk, skb, req, dst, |
| 1158 | req_unhash, own_req); |
| 1159 | |
| 1160 | if (!newsk) |
| 1161 | return NULL; |
| 1162 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1163 | inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1164 | |
| 1165 | newinet = inet_sk(newsk); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1166 | newnp = tcp_inet6_sk(newsk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1167 | newtp = tcp_sk(newsk); |
| 1168 | |
| 1169 | memcpy(newnp, np, sizeof(struct ipv6_pinfo)); |
| 1170 | |
| 1171 | newnp->saddr = newsk->sk_v6_rcv_saddr; |
| 1172 | |
| 1173 | inet_csk(newsk)->icsk_af_ops = &ipv6_mapped; |
| 1174 | newsk->sk_backlog_rcv = tcp_v4_do_rcv; |
| 1175 | #ifdef CONFIG_TCP_MD5SIG |
| 1176 | newtp->af_specific = &tcp_sock_ipv6_mapped_specific; |
| 1177 | #endif |
| 1178 | |
| 1179 | newnp->ipv6_mc_list = NULL; |
| 1180 | newnp->ipv6_ac_list = NULL; |
| 1181 | newnp->ipv6_fl_list = NULL; |
| 1182 | newnp->pktoptions = NULL; |
| 1183 | newnp->opt = NULL; |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1184 | newnp->mcast_oif = inet_iif(skb); |
| 1185 | newnp->mcast_hops = ip_hdr(skb)->ttl; |
| 1186 | newnp->rcv_flowinfo = 0; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1187 | if (np->repflow) |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1188 | newnp->flow_label = 0; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1189 | |
| 1190 | /* |
| 1191 | * No need to charge this sock to the relevant IPv6 refcnt debug socks count |
| 1192 | * here, tcp_create_openreq_child now does this for us, see the comment in |
| 1193 | * that function for the gory details. -acme |
| 1194 | */ |
| 1195 | |
| 1196 | /* It is tricky place. Until this moment IPv4 tcp |
| 1197 | worked with IPv6 icsk.icsk_af_ops. |
| 1198 | Sync it now. |
| 1199 | */ |
| 1200 | tcp_sync_mss(newsk, inet_csk(newsk)->icsk_pmtu_cookie); |
| 1201 | |
| 1202 | return newsk; |
| 1203 | } |
| 1204 | |
| 1205 | ireq = inet_rsk(req); |
| 1206 | |
| 1207 | if (sk_acceptq_is_full(sk)) |
| 1208 | goto out_overflow; |
| 1209 | |
| 1210 | if (!dst) { |
| 1211 | dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP); |
| 1212 | if (!dst) |
| 1213 | goto out; |
| 1214 | } |
| 1215 | |
| 1216 | newsk = tcp_create_openreq_child(sk, req, skb); |
| 1217 | if (!newsk) |
| 1218 | goto out_nonewsk; |
| 1219 | |
| 1220 | /* |
| 1221 | * No need to charge this sock to the relevant IPv6 refcnt debug socks |
| 1222 | * count here, tcp_create_openreq_child now does this for us, see the |
| 1223 | * comment in that function for the gory details. -acme |
| 1224 | */ |
| 1225 | |
| 1226 | newsk->sk_gso_type = SKB_GSO_TCPV6; |
| 1227 | ip6_dst_store(newsk, dst, NULL, NULL); |
| 1228 | inet6_sk_rx_dst_set(newsk, skb); |
| 1229 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1230 | inet_sk(newsk)->pinet6 = tcp_inet6_sk(newsk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1231 | |
| 1232 | newtp = tcp_sk(newsk); |
| 1233 | newinet = inet_sk(newsk); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1234 | newnp = tcp_inet6_sk(newsk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1235 | |
| 1236 | memcpy(newnp, np, sizeof(struct ipv6_pinfo)); |
| 1237 | |
| 1238 | newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr; |
| 1239 | newnp->saddr = ireq->ir_v6_loc_addr; |
| 1240 | newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr; |
| 1241 | newsk->sk_bound_dev_if = ireq->ir_iif; |
| 1242 | |
| 1243 | /* Now IPv6 options... |
| 1244 | |
| 1245 | First: no IPv4 options. |
| 1246 | */ |
| 1247 | newinet->inet_opt = NULL; |
| 1248 | newnp->ipv6_mc_list = NULL; |
| 1249 | newnp->ipv6_ac_list = NULL; |
| 1250 | newnp->ipv6_fl_list = NULL; |
| 1251 | |
| 1252 | /* Clone RX bits */ |
| 1253 | newnp->rxopt.all = np->rxopt.all; |
| 1254 | |
| 1255 | newnp->pktoptions = NULL; |
| 1256 | newnp->opt = NULL; |
| 1257 | newnp->mcast_oif = tcp_v6_iif(skb); |
| 1258 | newnp->mcast_hops = ipv6_hdr(skb)->hop_limit; |
| 1259 | newnp->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(skb)); |
| 1260 | if (np->repflow) |
| 1261 | newnp->flow_label = ip6_flowlabel(ipv6_hdr(skb)); |
| 1262 | |
| 1263 | /* Clone native IPv6 options from listening socket (if any) |
| 1264 | |
| 1265 | Yes, keeping reference count would be much more clever, |
| 1266 | but we make one more one thing there: reattach optmem |
| 1267 | to newsk. |
| 1268 | */ |
| 1269 | opt = ireq->ipv6_opt; |
| 1270 | if (!opt) |
| 1271 | opt = rcu_dereference(np->opt); |
| 1272 | if (opt) { |
| 1273 | opt = ipv6_dup_options(newsk, opt); |
| 1274 | RCU_INIT_POINTER(newnp->opt, opt); |
| 1275 | } |
| 1276 | inet_csk(newsk)->icsk_ext_hdr_len = 0; |
| 1277 | if (opt) |
| 1278 | inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen + |
| 1279 | opt->opt_flen; |
| 1280 | |
| 1281 | tcp_ca_openreq_child(newsk, dst); |
| 1282 | |
| 1283 | tcp_sync_mss(newsk, dst_mtu(dst)); |
| 1284 | newtp->advmss = tcp_mss_clamp(tcp_sk(sk), dst_metric_advmss(dst)); |
| 1285 | |
| 1286 | tcp_initialize_rcv_mss(newsk); |
| 1287 | |
| 1288 | newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6; |
| 1289 | newinet->inet_rcv_saddr = LOOPBACK4_IPV6; |
| 1290 | |
| 1291 | #ifdef CONFIG_TCP_MD5SIG |
| 1292 | /* Copy over the MD5 key from the original socket */ |
| 1293 | key = tcp_v6_md5_do_lookup(sk, &newsk->sk_v6_daddr); |
| 1294 | if (key) { |
| 1295 | /* We're using one, so create a matching key |
| 1296 | * on the newsk structure. If we fail to get |
| 1297 | * memory, then we end up not copying the key |
| 1298 | * across. Shucks. |
| 1299 | */ |
| 1300 | tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newsk->sk_v6_daddr, |
| 1301 | AF_INET6, 128, key->key, key->keylen, |
| 1302 | sk_gfp_mask(sk, GFP_ATOMIC)); |
| 1303 | } |
| 1304 | #endif |
| 1305 | |
| 1306 | if (__inet_inherit_port(sk, newsk) < 0) { |
| 1307 | inet_csk_prepare_forced_close(newsk); |
| 1308 | tcp_done(newsk); |
| 1309 | goto out; |
| 1310 | } |
| 1311 | *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash)); |
| 1312 | if (*own_req) { |
| 1313 | tcp_move_syn(newtp, req); |
| 1314 | |
| 1315 | /* Clone pktoptions received with SYN, if we own the req */ |
| 1316 | if (ireq->pktopts) { |
| 1317 | newnp->pktoptions = skb_clone(ireq->pktopts, |
| 1318 | sk_gfp_mask(sk, GFP_ATOMIC)); |
| 1319 | consume_skb(ireq->pktopts); |
| 1320 | ireq->pktopts = NULL; |
| 1321 | if (newnp->pktoptions) { |
| 1322 | tcp_v6_restore_cb(newnp->pktoptions); |
| 1323 | skb_set_owner_r(newnp->pktoptions, newsk); |
| 1324 | } |
| 1325 | } |
| 1326 | } |
| 1327 | |
| 1328 | return newsk; |
| 1329 | |
| 1330 | out_overflow: |
| 1331 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
| 1332 | out_nonewsk: |
| 1333 | dst_release(dst); |
| 1334 | out: |
| 1335 | tcp_listendrop(sk); |
| 1336 | return NULL; |
| 1337 | } |
| 1338 | |
| 1339 | /* The socket must have it's spinlock held when we get |
| 1340 | * here, unless it is a TCP_LISTEN socket. |
| 1341 | * |
| 1342 | * We have a potential double-lock case here, so even when |
| 1343 | * doing backlog processing we use the BH locking scheme. |
| 1344 | * This is because we cannot sleep with the original spinlock |
| 1345 | * held. |
| 1346 | */ |
| 1347 | static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) |
| 1348 | { |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1349 | struct ipv6_pinfo *np = tcp_inet6_sk(sk); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1350 | struct sk_buff *opt_skb = NULL; |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1351 | struct tcp_sock *tp; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1352 | |
| 1353 | /* Imagine: socket is IPv6. IPv4 packet arrives, |
| 1354 | goes to IPv4 receive handler and backlogged. |
| 1355 | From backlog it always goes here. Kerboom... |
| 1356 | Fortunately, tcp_rcv_established and rcv_established |
| 1357 | handle them correctly, but it is not case with |
| 1358 | tcp_v6_hnd_req and tcp_v6_send_reset(). --ANK |
| 1359 | */ |
| 1360 | |
| 1361 | if (skb->protocol == htons(ETH_P_IP)) |
| 1362 | return tcp_v4_do_rcv(sk, skb); |
| 1363 | |
| 1364 | /* |
| 1365 | * socket locking is here for SMP purposes as backlog rcv |
| 1366 | * is currently called with bh processing disabled. |
| 1367 | */ |
| 1368 | |
| 1369 | /* Do Stevens' IPV6_PKTOPTIONS. |
| 1370 | |
| 1371 | Yes, guys, it is the only place in our code, where we |
| 1372 | may make it not affecting IPv4. |
| 1373 | The rest of code is protocol independent, |
| 1374 | and I do not like idea to uglify IPv4. |
| 1375 | |
| 1376 | Actually, all the idea behind IPV6_PKTOPTIONS |
| 1377 | looks not very well thought. For now we latch |
| 1378 | options, received in the last packet, enqueued |
| 1379 | by tcp. Feel free to propose better solution. |
| 1380 | --ANK (980728) |
| 1381 | */ |
| 1382 | if (np->rxopt.all) |
| 1383 | opt_skb = skb_clone(skb, sk_gfp_mask(sk, GFP_ATOMIC)); |
| 1384 | |
| 1385 | if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
| 1386 | struct dst_entry *dst = sk->sk_rx_dst; |
| 1387 | |
| 1388 | sock_rps_save_rxhash(sk, skb); |
| 1389 | sk_mark_napi_id(sk, skb); |
| 1390 | if (dst) { |
| 1391 | if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif || |
| 1392 | dst->ops->check(dst, np->rx_dst_cookie) == NULL) { |
| 1393 | dst_release(dst); |
| 1394 | sk->sk_rx_dst = NULL; |
| 1395 | } |
| 1396 | } |
| 1397 | |
| 1398 | tcp_rcv_established(sk, skb); |
| 1399 | if (opt_skb) |
| 1400 | goto ipv6_pktoptions; |
| 1401 | return 0; |
| 1402 | } |
| 1403 | |
| 1404 | if (tcp_checksum_complete(skb)) |
| 1405 | goto csum_err; |
| 1406 | |
| 1407 | if (sk->sk_state == TCP_LISTEN) { |
| 1408 | struct sock *nsk = tcp_v6_cookie_check(sk, skb); |
| 1409 | |
| 1410 | if (!nsk) |
| 1411 | goto discard; |
| 1412 | |
| 1413 | if (nsk != sk) { |
| 1414 | if (tcp_child_process(sk, nsk, skb)) |
| 1415 | goto reset; |
| 1416 | if (opt_skb) |
| 1417 | __kfree_skb(opt_skb); |
| 1418 | return 0; |
| 1419 | } |
| 1420 | } else |
| 1421 | sock_rps_save_rxhash(sk, skb); |
| 1422 | |
| 1423 | if (tcp_rcv_state_process(sk, skb)) |
| 1424 | goto reset; |
| 1425 | if (opt_skb) |
| 1426 | goto ipv6_pktoptions; |
| 1427 | return 0; |
| 1428 | |
| 1429 | reset: |
| 1430 | tcp_v6_send_reset(sk, skb); |
| 1431 | discard: |
| 1432 | if (opt_skb) |
| 1433 | __kfree_skb(opt_skb); |
| 1434 | kfree_skb(skb); |
| 1435 | return 0; |
| 1436 | csum_err: |
| 1437 | TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); |
| 1438 | TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); |
| 1439 | goto discard; |
| 1440 | |
| 1441 | |
| 1442 | ipv6_pktoptions: |
| 1443 | /* Do you ask, what is it? |
| 1444 | |
| 1445 | 1. skb was enqueued by tcp. |
| 1446 | 2. skb is added to tail of read queue, rather than out of order. |
| 1447 | 3. socket is not in passive state. |
| 1448 | 4. Finally, it really contains options, which user wants to receive. |
| 1449 | */ |
| 1450 | tp = tcp_sk(sk); |
| 1451 | if (TCP_SKB_CB(opt_skb)->end_seq == tp->rcv_nxt && |
| 1452 | !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { |
| 1453 | if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo) |
| 1454 | np->mcast_oif = tcp_v6_iif(opt_skb); |
| 1455 | if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) |
| 1456 | np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit; |
| 1457 | if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass) |
| 1458 | np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb)); |
| 1459 | if (np->repflow) |
| 1460 | np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb)); |
| 1461 | if (ipv6_opt_accepted(sk, opt_skb, &TCP_SKB_CB(opt_skb)->header.h6)) { |
| 1462 | skb_set_owner_r(opt_skb, sk); |
| 1463 | tcp_v6_restore_cb(opt_skb); |
| 1464 | opt_skb = xchg(&np->pktoptions, opt_skb); |
| 1465 | } else { |
| 1466 | __kfree_skb(opt_skb); |
| 1467 | opt_skb = xchg(&np->pktoptions, NULL); |
| 1468 | } |
| 1469 | } |
| 1470 | |
| 1471 | kfree_skb(opt_skb); |
| 1472 | return 0; |
| 1473 | } |
| 1474 | |
| 1475 | static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr, |
| 1476 | const struct tcphdr *th) |
| 1477 | { |
| 1478 | /* This is tricky: we move IP6CB at its correct location into |
| 1479 | * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because |
| 1480 | * _decode_session6() uses IP6CB(). |
| 1481 | * barrier() makes sure compiler won't play aliasing games. |
| 1482 | */ |
| 1483 | memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb), |
| 1484 | sizeof(struct inet6_skb_parm)); |
| 1485 | barrier(); |
| 1486 | |
| 1487 | TCP_SKB_CB(skb)->seq = ntohl(th->seq); |
| 1488 | TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + |
| 1489 | skb->len - th->doff*4); |
| 1490 | TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); |
| 1491 | TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th); |
| 1492 | TCP_SKB_CB(skb)->tcp_tw_isn = 0; |
| 1493 | TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr); |
| 1494 | TCP_SKB_CB(skb)->sacked = 0; |
| 1495 | TCP_SKB_CB(skb)->has_rxtstamp = |
| 1496 | skb->tstamp || skb_hwtstamps(skb)->hwtstamp; |
| 1497 | } |
| 1498 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1499 | INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1500 | { |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1501 | struct sk_buff *skb_to_free; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1502 | int sdif = inet6_sdif(skb); |
| 1503 | const struct tcphdr *th; |
| 1504 | const struct ipv6hdr *hdr; |
| 1505 | bool refcounted; |
| 1506 | struct sock *sk; |
| 1507 | int ret; |
| 1508 | struct net *net = dev_net(skb->dev); |
| 1509 | |
| 1510 | if (skb->pkt_type != PACKET_HOST) |
| 1511 | goto discard_it; |
| 1512 | |
| 1513 | /* |
| 1514 | * Count it even if it's bad. |
| 1515 | */ |
| 1516 | __TCP_INC_STATS(net, TCP_MIB_INSEGS); |
| 1517 | |
| 1518 | if (!pskb_may_pull(skb, sizeof(struct tcphdr))) |
| 1519 | goto discard_it; |
| 1520 | |
| 1521 | th = (const struct tcphdr *)skb->data; |
| 1522 | |
| 1523 | if (unlikely(th->doff < sizeof(struct tcphdr)/4)) |
| 1524 | goto bad_packet; |
| 1525 | if (!pskb_may_pull(skb, th->doff*4)) |
| 1526 | goto discard_it; |
| 1527 | |
| 1528 | if (skb_checksum_init(skb, IPPROTO_TCP, ip6_compute_pseudo)) |
| 1529 | goto csum_error; |
| 1530 | |
| 1531 | th = (const struct tcphdr *)skb->data; |
| 1532 | hdr = ipv6_hdr(skb); |
| 1533 | |
| 1534 | lookup: |
| 1535 | sk = __inet6_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th), |
| 1536 | th->source, th->dest, inet6_iif(skb), sdif, |
| 1537 | &refcounted); |
| 1538 | if (!sk) |
| 1539 | goto no_tcp_socket; |
| 1540 | |
| 1541 | process: |
| 1542 | if (sk->sk_state == TCP_TIME_WAIT) |
| 1543 | goto do_time_wait; |
| 1544 | |
| 1545 | if (sk->sk_state == TCP_NEW_SYN_RECV) { |
| 1546 | struct request_sock *req = inet_reqsk(sk); |
| 1547 | bool req_stolen = false; |
| 1548 | struct sock *nsk; |
| 1549 | |
| 1550 | sk = req->rsk_listener; |
| 1551 | if (tcp_v6_inbound_md5_hash(sk, skb)) { |
| 1552 | sk_drops_add(sk, skb); |
| 1553 | reqsk_put(req); |
| 1554 | goto discard_it; |
| 1555 | } |
| 1556 | if (tcp_checksum_complete(skb)) { |
| 1557 | reqsk_put(req); |
| 1558 | goto csum_error; |
| 1559 | } |
| 1560 | if (unlikely(sk->sk_state != TCP_LISTEN)) { |
| 1561 | inet_csk_reqsk_queue_drop_and_put(sk, req); |
| 1562 | goto lookup; |
| 1563 | } |
| 1564 | sock_hold(sk); |
| 1565 | refcounted = true; |
| 1566 | nsk = NULL; |
| 1567 | if (!tcp_filter(sk, skb)) { |
| 1568 | th = (const struct tcphdr *)skb->data; |
| 1569 | hdr = ipv6_hdr(skb); |
| 1570 | tcp_v6_fill_cb(skb, hdr, th); |
| 1571 | nsk = tcp_check_req(sk, skb, req, false, &req_stolen); |
| 1572 | } |
| 1573 | if (!nsk) { |
| 1574 | reqsk_put(req); |
| 1575 | if (req_stolen) { |
| 1576 | /* Another cpu got exclusive access to req |
| 1577 | * and created a full blown socket. |
| 1578 | * Try to feed this packet to this socket |
| 1579 | * instead of discarding it. |
| 1580 | */ |
| 1581 | tcp_v6_restore_cb(skb); |
| 1582 | sock_put(sk); |
| 1583 | goto lookup; |
| 1584 | } |
| 1585 | goto discard_and_relse; |
| 1586 | } |
| 1587 | if (nsk == sk) { |
| 1588 | reqsk_put(req); |
| 1589 | tcp_v6_restore_cb(skb); |
| 1590 | } else if (tcp_child_process(sk, nsk, skb)) { |
| 1591 | tcp_v6_send_reset(nsk, skb); |
| 1592 | goto discard_and_relse; |
| 1593 | } else { |
| 1594 | sock_put(sk); |
| 1595 | return 0; |
| 1596 | } |
| 1597 | } |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1598 | if (hdr->hop_limit < tcp_inet6_sk(sk)->min_hopcount) { |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1599 | __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
| 1600 | goto discard_and_relse; |
| 1601 | } |
| 1602 | |
| 1603 | if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) |
| 1604 | goto discard_and_relse; |
| 1605 | |
| 1606 | if (tcp_v6_inbound_md5_hash(sk, skb)) |
| 1607 | goto discard_and_relse; |
| 1608 | |
| 1609 | if (tcp_filter(sk, skb)) |
| 1610 | goto discard_and_relse; |
| 1611 | th = (const struct tcphdr *)skb->data; |
| 1612 | hdr = ipv6_hdr(skb); |
| 1613 | tcp_v6_fill_cb(skb, hdr, th); |
| 1614 | |
| 1615 | skb->dev = NULL; |
| 1616 | |
| 1617 | if (sk->sk_state == TCP_LISTEN) { |
| 1618 | ret = tcp_v6_do_rcv(sk, skb); |
| 1619 | goto put_and_return; |
| 1620 | } |
| 1621 | |
| 1622 | sk_incoming_cpu_update(sk); |
| 1623 | |
| 1624 | bh_lock_sock_nested(sk); |
| 1625 | tcp_segs_in(tcp_sk(sk), skb); |
| 1626 | ret = 0; |
| 1627 | if (!sock_owned_by_user(sk)) { |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1628 | skb_to_free = sk->sk_rx_skb_cache; |
| 1629 | sk->sk_rx_skb_cache = NULL; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1630 | ret = tcp_v6_do_rcv(sk, skb); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1631 | } else { |
| 1632 | if (tcp_add_backlog(sk, skb)) |
| 1633 | goto discard_and_relse; |
| 1634 | skb_to_free = NULL; |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1635 | } |
| 1636 | bh_unlock_sock(sk); |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1637 | if (skb_to_free) |
| 1638 | __kfree_skb(skb_to_free); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1639 | put_and_return: |
| 1640 | if (refcounted) |
| 1641 | sock_put(sk); |
| 1642 | return ret ? -1 : 0; |
| 1643 | |
| 1644 | no_tcp_socket: |
| 1645 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) |
| 1646 | goto discard_it; |
| 1647 | |
| 1648 | tcp_v6_fill_cb(skb, hdr, th); |
| 1649 | |
| 1650 | if (tcp_checksum_complete(skb)) { |
| 1651 | csum_error: |
| 1652 | __TCP_INC_STATS(net, TCP_MIB_CSUMERRORS); |
| 1653 | bad_packet: |
| 1654 | __TCP_INC_STATS(net, TCP_MIB_INERRS); |
| 1655 | } else { |
| 1656 | tcp_v6_send_reset(NULL, skb); |
| 1657 | } |
| 1658 | |
| 1659 | discard_it: |
| 1660 | kfree_skb(skb); |
| 1661 | return 0; |
| 1662 | |
| 1663 | discard_and_relse: |
| 1664 | sk_drops_add(sk, skb); |
| 1665 | if (refcounted) |
| 1666 | sock_put(sk); |
| 1667 | goto discard_it; |
| 1668 | |
| 1669 | do_time_wait: |
| 1670 | if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| 1671 | inet_twsk_put(inet_twsk(sk)); |
| 1672 | goto discard_it; |
| 1673 | } |
| 1674 | |
| 1675 | tcp_v6_fill_cb(skb, hdr, th); |
| 1676 | |
| 1677 | if (tcp_checksum_complete(skb)) { |
| 1678 | inet_twsk_put(inet_twsk(sk)); |
| 1679 | goto csum_error; |
| 1680 | } |
| 1681 | |
| 1682 | switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { |
| 1683 | case TCP_TW_SYN: |
| 1684 | { |
| 1685 | struct sock *sk2; |
| 1686 | |
| 1687 | sk2 = inet6_lookup_listener(dev_net(skb->dev), &tcp_hashinfo, |
| 1688 | skb, __tcp_hdrlen(th), |
| 1689 | &ipv6_hdr(skb)->saddr, th->source, |
| 1690 | &ipv6_hdr(skb)->daddr, |
| 1691 | ntohs(th->dest), |
| 1692 | tcp_v6_iif_l3_slave(skb), |
| 1693 | sdif); |
| 1694 | if (sk2) { |
| 1695 | struct inet_timewait_sock *tw = inet_twsk(sk); |
| 1696 | inet_twsk_deschedule_put(tw); |
| 1697 | sk = sk2; |
| 1698 | tcp_v6_restore_cb(skb); |
| 1699 | refcounted = false; |
| 1700 | goto process; |
| 1701 | } |
| 1702 | } |
| 1703 | /* to ACK */ |
| 1704 | /* fall through */ |
| 1705 | case TCP_TW_ACK: |
| 1706 | tcp_v6_timewait_ack(sk, skb); |
| 1707 | break; |
| 1708 | case TCP_TW_RST: |
| 1709 | tcp_v6_send_reset(sk, skb); |
| 1710 | inet_twsk_deschedule_put(inet_twsk(sk)); |
| 1711 | goto discard_it; |
| 1712 | case TCP_TW_SUCCESS: |
| 1713 | ; |
| 1714 | } |
| 1715 | goto discard_it; |
| 1716 | } |
| 1717 | |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1718 | INDIRECT_CALLABLE_SCOPE void tcp_v6_early_demux(struct sk_buff *skb) |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1719 | { |
| 1720 | const struct ipv6hdr *hdr; |
| 1721 | const struct tcphdr *th; |
| 1722 | struct sock *sk; |
| 1723 | |
| 1724 | if (skb->pkt_type != PACKET_HOST) |
| 1725 | return; |
| 1726 | |
| 1727 | if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) |
| 1728 | return; |
| 1729 | |
| 1730 | hdr = ipv6_hdr(skb); |
| 1731 | th = tcp_hdr(skb); |
| 1732 | |
| 1733 | if (th->doff < sizeof(struct tcphdr) / 4) |
| 1734 | return; |
| 1735 | |
| 1736 | /* Note : We use inet6_iif() here, not tcp_v6_iif() */ |
| 1737 | sk = __inet6_lookup_established(dev_net(skb->dev), &tcp_hashinfo, |
| 1738 | &hdr->saddr, th->source, |
| 1739 | &hdr->daddr, ntohs(th->dest), |
| 1740 | inet6_iif(skb), inet6_sdif(skb)); |
| 1741 | if (sk) { |
| 1742 | skb->sk = sk; |
| 1743 | skb->destructor = sock_edemux; |
| 1744 | if (sk_fullsock(sk)) { |
| 1745 | struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst); |
| 1746 | |
| 1747 | if (dst) |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1748 | dst = dst_check(dst, tcp_inet6_sk(sk)->rx_dst_cookie); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1749 | if (dst && |
| 1750 | inet_sk(sk)->rx_dst_ifindex == skb->skb_iif) |
| 1751 | skb_dst_set_noref(skb, dst); |
| 1752 | } |
| 1753 | } |
| 1754 | } |
| 1755 | |
| 1756 | static struct timewait_sock_ops tcp6_timewait_sock_ops = { |
| 1757 | .twsk_obj_size = sizeof(struct tcp6_timewait_sock), |
| 1758 | .twsk_unique = tcp_twsk_unique, |
| 1759 | .twsk_destructor = tcp_twsk_destructor, |
| 1760 | }; |
| 1761 | |
| 1762 | static const struct inet_connection_sock_af_ops ipv6_specific = { |
| 1763 | .queue_xmit = inet6_csk_xmit, |
| 1764 | .send_check = tcp_v6_send_check, |
| 1765 | .rebuild_header = inet6_sk_rebuild_header, |
| 1766 | .sk_rx_dst_set = inet6_sk_rx_dst_set, |
| 1767 | .conn_request = tcp_v6_conn_request, |
| 1768 | .syn_recv_sock = tcp_v6_syn_recv_sock, |
| 1769 | .net_header_len = sizeof(struct ipv6hdr), |
| 1770 | .net_frag_header_len = sizeof(struct frag_hdr), |
| 1771 | .setsockopt = ipv6_setsockopt, |
| 1772 | .getsockopt = ipv6_getsockopt, |
| 1773 | .addr2sockaddr = inet6_csk_addr2sockaddr, |
| 1774 | .sockaddr_len = sizeof(struct sockaddr_in6), |
| 1775 | #ifdef CONFIG_COMPAT |
| 1776 | .compat_setsockopt = compat_ipv6_setsockopt, |
| 1777 | .compat_getsockopt = compat_ipv6_getsockopt, |
| 1778 | #endif |
| 1779 | .mtu_reduced = tcp_v6_mtu_reduced, |
| 1780 | }; |
| 1781 | |
| 1782 | #ifdef CONFIG_TCP_MD5SIG |
| 1783 | static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = { |
| 1784 | .md5_lookup = tcp_v6_md5_lookup, |
| 1785 | .calc_md5_hash = tcp_v6_md5_hash_skb, |
| 1786 | .md5_parse = tcp_v6_parse_md5_keys, |
| 1787 | }; |
| 1788 | #endif |
| 1789 | |
| 1790 | /* |
| 1791 | * TCP over IPv4 via INET6 API |
| 1792 | */ |
| 1793 | static const struct inet_connection_sock_af_ops ipv6_mapped = { |
| 1794 | .queue_xmit = ip_queue_xmit, |
| 1795 | .send_check = tcp_v4_send_check, |
| 1796 | .rebuild_header = inet_sk_rebuild_header, |
| 1797 | .sk_rx_dst_set = inet_sk_rx_dst_set, |
| 1798 | .conn_request = tcp_v6_conn_request, |
| 1799 | .syn_recv_sock = tcp_v6_syn_recv_sock, |
| 1800 | .net_header_len = sizeof(struct iphdr), |
| 1801 | .setsockopt = ipv6_setsockopt, |
| 1802 | .getsockopt = ipv6_getsockopt, |
| 1803 | .addr2sockaddr = inet6_csk_addr2sockaddr, |
| 1804 | .sockaddr_len = sizeof(struct sockaddr_in6), |
| 1805 | #ifdef CONFIG_COMPAT |
| 1806 | .compat_setsockopt = compat_ipv6_setsockopt, |
| 1807 | .compat_getsockopt = compat_ipv6_getsockopt, |
| 1808 | #endif |
| 1809 | .mtu_reduced = tcp_v4_mtu_reduced, |
| 1810 | }; |
| 1811 | |
| 1812 | #ifdef CONFIG_TCP_MD5SIG |
| 1813 | static const struct tcp_sock_af_ops tcp_sock_ipv6_mapped_specific = { |
| 1814 | .md5_lookup = tcp_v4_md5_lookup, |
| 1815 | .calc_md5_hash = tcp_v4_md5_hash_skb, |
| 1816 | .md5_parse = tcp_v6_parse_md5_keys, |
| 1817 | }; |
| 1818 | #endif |
| 1819 | |
| 1820 | /* NOTE: A lot of things set to zero explicitly by call to |
| 1821 | * sk_alloc() so need not be done here. |
| 1822 | */ |
| 1823 | static int tcp_v6_init_sock(struct sock *sk) |
| 1824 | { |
| 1825 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 1826 | |
| 1827 | tcp_init_sock(sk); |
| 1828 | |
| 1829 | icsk->icsk_af_ops = &ipv6_specific; |
| 1830 | |
| 1831 | #ifdef CONFIG_TCP_MD5SIG |
| 1832 | tcp_sk(sk)->af_specific = &tcp_sock_ipv6_specific; |
| 1833 | #endif |
| 1834 | |
| 1835 | return 0; |
| 1836 | } |
| 1837 | |
| 1838 | static void tcp_v6_destroy_sock(struct sock *sk) |
| 1839 | { |
| 1840 | tcp_v4_destroy_sock(sk); |
| 1841 | inet6_destroy_sock(sk); |
| 1842 | } |
| 1843 | |
| 1844 | #ifdef CONFIG_PROC_FS |
| 1845 | /* Proc filesystem TCPv6 sock list dumping. */ |
| 1846 | static void get_openreq6(struct seq_file *seq, |
| 1847 | const struct request_sock *req, int i) |
| 1848 | { |
| 1849 | long ttd = req->rsk_timer.expires - jiffies; |
| 1850 | const struct in6_addr *src = &inet_rsk(req)->ir_v6_loc_addr; |
| 1851 | const struct in6_addr *dest = &inet_rsk(req)->ir_v6_rmt_addr; |
| 1852 | |
| 1853 | if (ttd < 0) |
| 1854 | ttd = 0; |
| 1855 | |
| 1856 | seq_printf(seq, |
| 1857 | "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " |
| 1858 | "%02X %08X:%08X %02X:%08lX %08X %5u %8d %d %d %pK\n", |
| 1859 | i, |
| 1860 | src->s6_addr32[0], src->s6_addr32[1], |
| 1861 | src->s6_addr32[2], src->s6_addr32[3], |
| 1862 | inet_rsk(req)->ir_num, |
| 1863 | dest->s6_addr32[0], dest->s6_addr32[1], |
| 1864 | dest->s6_addr32[2], dest->s6_addr32[3], |
| 1865 | ntohs(inet_rsk(req)->ir_rmt_port), |
| 1866 | TCP_SYN_RECV, |
| 1867 | 0, 0, /* could print option size, but that is af dependent. */ |
| 1868 | 1, /* timers active (only the expire timer) */ |
| 1869 | jiffies_to_clock_t(ttd), |
| 1870 | req->num_timeout, |
| 1871 | from_kuid_munged(seq_user_ns(seq), |
| 1872 | sock_i_uid(req->rsk_listener)), |
| 1873 | 0, /* non standard timer */ |
| 1874 | 0, /* open_requests have no inode */ |
| 1875 | 0, req); |
| 1876 | } |
| 1877 | |
| 1878 | static void get_tcp6_sock(struct seq_file *seq, struct sock *sp, int i) |
| 1879 | { |
| 1880 | const struct in6_addr *dest, *src; |
| 1881 | __u16 destp, srcp; |
| 1882 | int timer_active; |
| 1883 | unsigned long timer_expires; |
| 1884 | const struct inet_sock *inet = inet_sk(sp); |
| 1885 | const struct tcp_sock *tp = tcp_sk(sp); |
| 1886 | const struct inet_connection_sock *icsk = inet_csk(sp); |
| 1887 | const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; |
| 1888 | int rx_queue; |
| 1889 | int state; |
| 1890 | |
| 1891 | dest = &sp->sk_v6_daddr; |
| 1892 | src = &sp->sk_v6_rcv_saddr; |
| 1893 | destp = ntohs(inet->inet_dport); |
| 1894 | srcp = ntohs(inet->inet_sport); |
| 1895 | |
| 1896 | if (icsk->icsk_pending == ICSK_TIME_RETRANS || |
| 1897 | icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT || |
| 1898 | icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) { |
| 1899 | timer_active = 1; |
| 1900 | timer_expires = icsk->icsk_timeout; |
| 1901 | } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) { |
| 1902 | timer_active = 4; |
| 1903 | timer_expires = icsk->icsk_timeout; |
| 1904 | } else if (timer_pending(&sp->sk_timer)) { |
| 1905 | timer_active = 2; |
| 1906 | timer_expires = sp->sk_timer.expires; |
| 1907 | } else { |
| 1908 | timer_active = 0; |
| 1909 | timer_expires = jiffies; |
| 1910 | } |
| 1911 | |
| 1912 | state = inet_sk_state_load(sp); |
| 1913 | if (state == TCP_LISTEN) |
| 1914 | rx_queue = sp->sk_ack_backlog; |
| 1915 | else |
| 1916 | /* Because we don't lock the socket, |
| 1917 | * we might find a transient negative value. |
| 1918 | */ |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1919 | rx_queue = max_t(int, READ_ONCE(tp->rcv_nxt) - |
| 1920 | READ_ONCE(tp->copied_seq), 0); |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1921 | |
| 1922 | seq_printf(seq, |
| 1923 | "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " |
| 1924 | "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d %pK %lu %lu %u %u %d\n", |
| 1925 | i, |
| 1926 | src->s6_addr32[0], src->s6_addr32[1], |
| 1927 | src->s6_addr32[2], src->s6_addr32[3], srcp, |
| 1928 | dest->s6_addr32[0], dest->s6_addr32[1], |
| 1929 | dest->s6_addr32[2], dest->s6_addr32[3], destp, |
| 1930 | state, |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1931 | READ_ONCE(tp->write_seq) - tp->snd_una, |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1932 | rx_queue, |
| 1933 | timer_active, |
| 1934 | jiffies_delta_to_clock_t(timer_expires - jiffies), |
| 1935 | icsk->icsk_retransmits, |
| 1936 | from_kuid_munged(seq_user_ns(seq), sock_i_uid(sp)), |
| 1937 | icsk->icsk_probes_out, |
| 1938 | sock_i_ino(sp), |
| 1939 | refcount_read(&sp->sk_refcnt), sp, |
| 1940 | jiffies_to_clock_t(icsk->icsk_rto), |
| 1941 | jiffies_to_clock_t(icsk->icsk_ack.ato), |
David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame] | 1942 | (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(sp), |
Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 1943 | tp->snd_cwnd, |
| 1944 | state == TCP_LISTEN ? |
| 1945 | fastopenq->max_qlen : |
| 1946 | (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh) |
| 1947 | ); |
| 1948 | } |
| 1949 | |
| 1950 | static void get_timewait6_sock(struct seq_file *seq, |
| 1951 | struct inet_timewait_sock *tw, int i) |
| 1952 | { |
| 1953 | long delta = tw->tw_timer.expires - jiffies; |
| 1954 | const struct in6_addr *dest, *src; |
| 1955 | __u16 destp, srcp; |
| 1956 | |
| 1957 | dest = &tw->tw_v6_daddr; |
| 1958 | src = &tw->tw_v6_rcv_saddr; |
| 1959 | destp = ntohs(tw->tw_dport); |
| 1960 | srcp = ntohs(tw->tw_sport); |
| 1961 | |
| 1962 | seq_printf(seq, |
| 1963 | "%4d: %08X%08X%08X%08X:%04X %08X%08X%08X%08X:%04X " |
| 1964 | "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n", |
| 1965 | i, |
| 1966 | src->s6_addr32[0], src->s6_addr32[1], |
| 1967 | src->s6_addr32[2], src->s6_addr32[3], srcp, |
| 1968 | dest->s6_addr32[0], dest->s6_addr32[1], |
| 1969 | dest->s6_addr32[2], dest->s6_addr32[3], destp, |
| 1970 | tw->tw_substate, 0, 0, |
| 1971 | 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, |
| 1972 | refcount_read(&tw->tw_refcnt), tw); |
| 1973 | } |
| 1974 | |
| 1975 | static int tcp6_seq_show(struct seq_file *seq, void *v) |
| 1976 | { |
| 1977 | struct tcp_iter_state *st; |
| 1978 | struct sock *sk = v; |
| 1979 | |
| 1980 | if (v == SEQ_START_TOKEN) { |
| 1981 | seq_puts(seq, |
| 1982 | " sl " |
| 1983 | "local_address " |
| 1984 | "remote_address " |
| 1985 | "st tx_queue rx_queue tr tm->when retrnsmt" |
| 1986 | " uid timeout inode\n"); |
| 1987 | goto out; |
| 1988 | } |
| 1989 | st = seq->private; |
| 1990 | |
| 1991 | if (sk->sk_state == TCP_TIME_WAIT) |
| 1992 | get_timewait6_sock(seq, v, st->num); |
| 1993 | else if (sk->sk_state == TCP_NEW_SYN_RECV) |
| 1994 | get_openreq6(seq, v, st->num); |
| 1995 | else |
| 1996 | get_tcp6_sock(seq, v, st->num); |
| 1997 | out: |
| 1998 | return 0; |
| 1999 | } |
| 2000 | |
| 2001 | static const struct seq_operations tcp6_seq_ops = { |
| 2002 | .show = tcp6_seq_show, |
| 2003 | .start = tcp_seq_start, |
| 2004 | .next = tcp_seq_next, |
| 2005 | .stop = tcp_seq_stop, |
| 2006 | }; |
| 2007 | |
| 2008 | static struct tcp_seq_afinfo tcp6_seq_afinfo = { |
| 2009 | .family = AF_INET6, |
| 2010 | }; |
| 2011 | |
| 2012 | int __net_init tcp6_proc_init(struct net *net) |
| 2013 | { |
| 2014 | if (!proc_create_net_data("tcp6", 0444, net->proc_net, &tcp6_seq_ops, |
| 2015 | sizeof(struct tcp_iter_state), &tcp6_seq_afinfo)) |
| 2016 | return -ENOMEM; |
| 2017 | return 0; |
| 2018 | } |
| 2019 | |
| 2020 | void tcp6_proc_exit(struct net *net) |
| 2021 | { |
| 2022 | remove_proc_entry("tcp6", net->proc_net); |
| 2023 | } |
| 2024 | #endif |
| 2025 | |
| 2026 | struct proto tcpv6_prot = { |
| 2027 | .name = "TCPv6", |
| 2028 | .owner = THIS_MODULE, |
| 2029 | .close = tcp_close, |
| 2030 | .pre_connect = tcp_v6_pre_connect, |
| 2031 | .connect = tcp_v6_connect, |
| 2032 | .disconnect = tcp_disconnect, |
| 2033 | .accept = inet_csk_accept, |
| 2034 | .ioctl = tcp_ioctl, |
| 2035 | .init = tcp_v6_init_sock, |
| 2036 | .destroy = tcp_v6_destroy_sock, |
| 2037 | .shutdown = tcp_shutdown, |
| 2038 | .setsockopt = tcp_setsockopt, |
| 2039 | .getsockopt = tcp_getsockopt, |
| 2040 | .keepalive = tcp_set_keepalive, |
| 2041 | .recvmsg = tcp_recvmsg, |
| 2042 | .sendmsg = tcp_sendmsg, |
| 2043 | .sendpage = tcp_sendpage, |
| 2044 | .backlog_rcv = tcp_v6_do_rcv, |
| 2045 | .release_cb = tcp_release_cb, |
| 2046 | .hash = inet6_hash, |
| 2047 | .unhash = inet_unhash, |
| 2048 | .get_port = inet_csk_get_port, |
| 2049 | .enter_memory_pressure = tcp_enter_memory_pressure, |
| 2050 | .leave_memory_pressure = tcp_leave_memory_pressure, |
| 2051 | .stream_memory_free = tcp_stream_memory_free, |
| 2052 | .sockets_allocated = &tcp_sockets_allocated, |
| 2053 | .memory_allocated = &tcp_memory_allocated, |
| 2054 | .memory_pressure = &tcp_memory_pressure, |
| 2055 | .orphan_count = &tcp_orphan_count, |
| 2056 | .sysctl_mem = sysctl_tcp_mem, |
| 2057 | .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), |
| 2058 | .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), |
| 2059 | .max_header = MAX_TCP_HEADER, |
| 2060 | .obj_size = sizeof(struct tcp6_sock), |
| 2061 | .slab_flags = SLAB_TYPESAFE_BY_RCU, |
| 2062 | .twsk_prot = &tcp6_timewait_sock_ops, |
| 2063 | .rsk_prot = &tcp6_request_sock_ops, |
| 2064 | .h.hashinfo = &tcp_hashinfo, |
| 2065 | .no_autobind = true, |
| 2066 | #ifdef CONFIG_COMPAT |
| 2067 | .compat_setsockopt = compat_tcp_setsockopt, |
| 2068 | .compat_getsockopt = compat_tcp_getsockopt, |
| 2069 | #endif |
| 2070 | .diag_destroy = tcp_abort, |
| 2071 | }; |
| 2072 | |
| 2073 | /* thinking of making this const? Don't. |
| 2074 | * early_demux can change based on sysctl. |
| 2075 | */ |
| 2076 | static struct inet6_protocol tcpv6_protocol = { |
| 2077 | .early_demux = tcp_v6_early_demux, |
| 2078 | .early_demux_handler = tcp_v6_early_demux, |
| 2079 | .handler = tcp_v6_rcv, |
| 2080 | .err_handler = tcp_v6_err, |
| 2081 | .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
| 2082 | }; |
| 2083 | |
| 2084 | static struct inet_protosw tcpv6_protosw = { |
| 2085 | .type = SOCK_STREAM, |
| 2086 | .protocol = IPPROTO_TCP, |
| 2087 | .prot = &tcpv6_prot, |
| 2088 | .ops = &inet6_stream_ops, |
| 2089 | .flags = INET_PROTOSW_PERMANENT | |
| 2090 | INET_PROTOSW_ICSK, |
| 2091 | }; |
| 2092 | |
| 2093 | static int __net_init tcpv6_net_init(struct net *net) |
| 2094 | { |
| 2095 | return inet_ctl_sock_create(&net->ipv6.tcp_sk, PF_INET6, |
| 2096 | SOCK_RAW, IPPROTO_TCP, net); |
| 2097 | } |
| 2098 | |
| 2099 | static void __net_exit tcpv6_net_exit(struct net *net) |
| 2100 | { |
| 2101 | inet_ctl_sock_destroy(net->ipv6.tcp_sk); |
| 2102 | } |
| 2103 | |
| 2104 | static void __net_exit tcpv6_net_exit_batch(struct list_head *net_exit_list) |
| 2105 | { |
| 2106 | inet_twsk_purge(&tcp_hashinfo, AF_INET6); |
| 2107 | } |
| 2108 | |
| 2109 | static struct pernet_operations tcpv6_net_ops = { |
| 2110 | .init = tcpv6_net_init, |
| 2111 | .exit = tcpv6_net_exit, |
| 2112 | .exit_batch = tcpv6_net_exit_batch, |
| 2113 | }; |
| 2114 | |
| 2115 | int __init tcpv6_init(void) |
| 2116 | { |
| 2117 | int ret; |
| 2118 | |
| 2119 | ret = inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP); |
| 2120 | if (ret) |
| 2121 | goto out; |
| 2122 | |
| 2123 | /* register inet6 protocol */ |
| 2124 | ret = inet6_register_protosw(&tcpv6_protosw); |
| 2125 | if (ret) |
| 2126 | goto out_tcpv6_protocol; |
| 2127 | |
| 2128 | ret = register_pernet_subsys(&tcpv6_net_ops); |
| 2129 | if (ret) |
| 2130 | goto out_tcpv6_protosw; |
| 2131 | out: |
| 2132 | return ret; |
| 2133 | |
| 2134 | out_tcpv6_protosw: |
| 2135 | inet6_unregister_protosw(&tcpv6_protosw); |
| 2136 | out_tcpv6_protocol: |
| 2137 | inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); |
| 2138 | goto out; |
| 2139 | } |
| 2140 | |
| 2141 | void tcpv6_exit(void) |
| 2142 | { |
| 2143 | unregister_pernet_subsys(&tcpv6_net_ops); |
| 2144 | inet6_unregister_protosw(&tcpv6_protosw); |
| 2145 | inet6_del_protocol(&tcpv6_protocol, IPPROTO_TCP); |
| 2146 | } |