| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * INET An implementation of the TCP/IP protocol suite for the LINUX |
| * operating system. INET is implemented using the BSD Socket |
| * interface as the means of communication with the user level. |
| * |
| * Implementation of the Transmission Control Protocol(TCP). |
| * |
| * IPv4 specific functions |
| * |
| * code split from: |
| * linux/ipv4/tcp.c |
| * linux/ipv4/tcp_input.c |
| * linux/ipv4/tcp_output.c |
| * |
| * See tcp.c for author information |
| */ |
| |
| /* |
| * Changes: |
| * David S. Miller : New socket lookup architecture. |
| * This code is dedicated to John Dyson. |
| * David S. Miller : Change semantics of established hash, |
| * half is devoted to TIME_WAIT sockets |
| * and the rest go in the other half. |
| * Andi Kleen : Add support for syncookies and fixed |
| * some bugs: ip options weren't passed to |
| * the TCP layer, missed a check for an |
| * ACK bit. |
| * Andi Kleen : Implemented fast path mtu discovery. |
| * Fixed many serious bugs in the |
| * request_sock handling and moved |
| * most of it into the af independent code. |
| * Added tail drop and some other bugfixes. |
| * Added new listen semantics. |
| * Mike McLagan : Routing by source |
| * Juan Jose Ciarlante: ip_dynaddr bits |
| * Andi Kleen: various fixes. |
| * Vitaly E. Lavrov : Transparent proxy revived after year |
| * coma. |
| * Andi Kleen : Fix new listen. |
| * Andi Kleen : Fix accept error reporting. |
| * 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. |
| */ |
| |
| #define pr_fmt(fmt) "TCP: " fmt |
| |
| #include <linux/bottom_half.h> |
| #include <linux/types.h> |
| #include <linux/fcntl.h> |
| #include <linux/module.h> |
| #include <linux/random.h> |
| #include <linux/cache.h> |
| #include <linux/jhash.h> |
| #include <linux/init.h> |
| #include <linux/times.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| |
| #include <net/net_namespace.h> |
| #include <net/icmp.h> |
| #include <net/inet_hashtables.h> |
| #include <net/tcp.h> |
| #include <net/transp_v6.h> |
| #include <net/ipv6.h> |
| #include <net/inet_common.h> |
| #include <net/timewait_sock.h> |
| #include <net/xfrm.h> |
| #include <net/secure_seq.h> |
| #include <net/busy_poll.h> |
| #include <net/rstreason.h> |
| |
| #include <linux/inet.h> |
| #include <linux/ipv6.h> |
| #include <linux/stddef.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/inetdevice.h> |
| #include <linux/btf_ids.h> |
| |
| #include <crypto/hash.h> |
| #include <linux/scatterlist.h> |
| |
| #include <trace/events/tcp.h> |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
| __be32 daddr, __be32 saddr, const struct tcphdr *th); |
| #endif |
| |
| struct inet_hashinfo tcp_hashinfo; |
| EXPORT_SYMBOL(tcp_hashinfo); |
| |
| static DEFINE_PER_CPU(struct sock_bh_locked, ipv4_tcp_sk) = { |
| .bh_lock = INIT_LOCAL_LOCK(bh_lock), |
| }; |
| |
| static u32 tcp_v4_init_seq(const struct sk_buff *skb) |
| { |
| return secure_tcp_seq(ip_hdr(skb)->daddr, |
| ip_hdr(skb)->saddr, |
| tcp_hdr(skb)->dest, |
| tcp_hdr(skb)->source); |
| } |
| |
| static u32 tcp_v4_init_ts_off(const struct net *net, const struct sk_buff *skb) |
| { |
| return secure_tcp_ts_off(net, ip_hdr(skb)->daddr, ip_hdr(skb)->saddr); |
| } |
| |
| int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) |
| { |
| int reuse = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tw_reuse); |
| const struct inet_timewait_sock *tw = inet_twsk(sktw); |
| const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); |
| struct tcp_sock *tp = tcp_sk(sk); |
| int ts_recent_stamp; |
| |
| if (reuse == 2) { |
| /* Still does not detect *everything* that goes through |
| * lo, since we require a loopback src or dst address |
| * or direct binding to 'lo' interface. |
| */ |
| bool loopback = false; |
| if (tw->tw_bound_dev_if == LOOPBACK_IFINDEX) |
| loopback = true; |
| #if IS_ENABLED(CONFIG_IPV6) |
| if (tw->tw_family == AF_INET6) { |
| if (ipv6_addr_loopback(&tw->tw_v6_daddr) || |
| ipv6_addr_v4mapped_loopback(&tw->tw_v6_daddr) || |
| ipv6_addr_loopback(&tw->tw_v6_rcv_saddr) || |
| ipv6_addr_v4mapped_loopback(&tw->tw_v6_rcv_saddr)) |
| loopback = true; |
| } else |
| #endif |
| { |
| if (ipv4_is_loopback(tw->tw_daddr) || |
| ipv4_is_loopback(tw->tw_rcv_saddr)) |
| loopback = true; |
| } |
| if (!loopback) |
| reuse = 0; |
| } |
| |
| /* With PAWS, it is safe from the viewpoint |
| of data integrity. Even without PAWS it is safe provided sequence |
| spaces do not overlap i.e. at data rates <= 80Mbit/sec. |
| |
| Actually, the idea is close to VJ's one, only timestamp cache is |
| held not per host, but per port pair and TW bucket is used as state |
| holder. |
| |
| If TW bucket has been already destroyed we fall back to VJ's scheme |
| and use initial timestamp retrieved from peer table. |
| */ |
| ts_recent_stamp = READ_ONCE(tcptw->tw_ts_recent_stamp); |
| if (ts_recent_stamp && |
| (!twp || (reuse && time_after32(ktime_get_seconds(), |
| ts_recent_stamp)))) { |
| /* inet_twsk_hashdance_schedule() sets sk_refcnt after putting twsk |
| * and releasing the bucket lock. |
| */ |
| if (unlikely(!refcount_inc_not_zero(&sktw->sk_refcnt))) |
| return 0; |
| |
| /* In case of repair and re-using TIME-WAIT sockets we still |
| * want to be sure that it is safe as above but honor the |
| * sequence numbers and time stamps set as part of the repair |
| * process. |
| * |
| * Without this check re-using a TIME-WAIT socket with TCP |
| * repair would accumulate a -1 on the repair assigned |
| * sequence number. The first time it is reused the sequence |
| * is -1, the second time -2, etc. This fixes that issue |
| * without appearing to create any others. |
| */ |
| if (likely(!tp->repair)) { |
| u32 seq = tcptw->tw_snd_nxt + 65535 + 2; |
| |
| if (!seq) |
| seq = 1; |
| WRITE_ONCE(tp->write_seq, seq); |
| tp->rx_opt.ts_recent = READ_ONCE(tcptw->tw_ts_recent); |
| tp->rx_opt.ts_recent_stamp = ts_recent_stamp; |
| } |
| |
| return 1; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(tcp_twsk_unique); |
| |
| static int tcp_v4_pre_connect(struct sock *sk, struct sockaddr *uaddr, |
| int addr_len) |
| { |
| /* This check is replicated from tcp_v4_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 < sizeof(struct sockaddr_in)) |
| return -EINVAL; |
| |
| sock_owned_by_me(sk); |
| |
| return BPF_CGROUP_RUN_PROG_INET4_CONNECT(sk, uaddr, &addr_len); |
| } |
| |
| /* This will initiate an outgoing connection. */ |
| int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) |
| { |
| struct sockaddr_in *usin = (struct sockaddr_in *)uaddr; |
| struct inet_timewait_death_row *tcp_death_row; |
| struct inet_sock *inet = inet_sk(sk); |
| struct tcp_sock *tp = tcp_sk(sk); |
| struct ip_options_rcu *inet_opt; |
| struct net *net = sock_net(sk); |
| __be16 orig_sport, orig_dport; |
| __be32 daddr, nexthop; |
| struct flowi4 *fl4; |
| struct rtable *rt; |
| int err; |
| |
| if (addr_len < sizeof(struct sockaddr_in)) |
| return -EINVAL; |
| |
| if (usin->sin_family != AF_INET) |
| return -EAFNOSUPPORT; |
| |
| nexthop = daddr = usin->sin_addr.s_addr; |
| inet_opt = rcu_dereference_protected(inet->inet_opt, |
| lockdep_sock_is_held(sk)); |
| if (inet_opt && inet_opt->opt.srr) { |
| if (!daddr) |
| return -EINVAL; |
| nexthop = inet_opt->opt.faddr; |
| } |
| |
| orig_sport = inet->inet_sport; |
| orig_dport = usin->sin_port; |
| fl4 = &inet->cork.fl.u.ip4; |
| rt = ip_route_connect(fl4, nexthop, inet->inet_saddr, |
| sk->sk_bound_dev_if, IPPROTO_TCP, orig_sport, |
| orig_dport, sk); |
| if (IS_ERR(rt)) { |
| err = PTR_ERR(rt); |
| if (err == -ENETUNREACH) |
| IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); |
| return err; |
| } |
| |
| if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { |
| ip_rt_put(rt); |
| return -ENETUNREACH; |
| } |
| |
| if (!inet_opt || !inet_opt->opt.srr) |
| daddr = fl4->daddr; |
| |
| tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row; |
| |
| if (!inet->inet_saddr) { |
| err = inet_bhash2_update_saddr(sk, &fl4->saddr, AF_INET); |
| if (err) { |
| ip_rt_put(rt); |
| return err; |
| } |
| } else { |
| sk_rcv_saddr_set(sk, inet->inet_saddr); |
| } |
| |
| if (tp->rx_opt.ts_recent_stamp && inet->inet_daddr != daddr) { |
| /* Reset inherited state */ |
| tp->rx_opt.ts_recent = 0; |
| tp->rx_opt.ts_recent_stamp = 0; |
| if (likely(!tp->repair)) |
| WRITE_ONCE(tp->write_seq, 0); |
| } |
| |
| inet->inet_dport = usin->sin_port; |
| sk_daddr_set(sk, daddr); |
| |
| inet_csk(sk)->icsk_ext_hdr_len = 0; |
| if (inet_opt) |
| inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen; |
| |
| tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT; |
| |
| /* Socket identity is still unknown (sport may be zero). |
| * However we set state to SYN-SENT and not releasing socket |
| * lock select source port, enter ourselves into the hash tables and |
| * complete initialization after this. |
| */ |
| tcp_set_state(sk, TCP_SYN_SENT); |
| err = inet_hash_connect(tcp_death_row, sk); |
| if (err) |
| goto failure; |
| |
| sk_set_txhash(sk); |
| |
| rt = ip_route_newports(fl4, rt, orig_sport, orig_dport, |
| inet->inet_sport, inet->inet_dport, sk); |
| if (IS_ERR(rt)) { |
| err = PTR_ERR(rt); |
| rt = NULL; |
| goto failure; |
| } |
| tp->tcp_usec_ts = dst_tcp_usec_ts(&rt->dst); |
| /* OK, now commit destination to socket. */ |
| sk->sk_gso_type = SKB_GSO_TCPV4; |
| sk_setup_caps(sk, &rt->dst); |
| rt = NULL; |
| |
| if (likely(!tp->repair)) { |
| if (!tp->write_seq) |
| WRITE_ONCE(tp->write_seq, |
| secure_tcp_seq(inet->inet_saddr, |
| inet->inet_daddr, |
| inet->inet_sport, |
| usin->sin_port)); |
| WRITE_ONCE(tp->tsoffset, |
| secure_tcp_ts_off(net, inet->inet_saddr, |
| inet->inet_daddr)); |
| } |
| |
| atomic_set(&inet->inet_id, get_random_u16()); |
| |
| if (tcp_fastopen_defer_connect(sk, &err)) |
| return err; |
| if (err) |
| goto failure; |
| |
| err = tcp_connect(sk); |
| |
| if (err) |
| goto failure; |
| |
| return 0; |
| |
| failure: |
| /* |
| * This unhashes the socket and releases the local port, |
| * if necessary. |
| */ |
| tcp_set_state(sk, TCP_CLOSE); |
| inet_bhash2_reset_saddr(sk); |
| ip_rt_put(rt); |
| sk->sk_route_caps = 0; |
| inet->inet_dport = 0; |
| return err; |
| } |
| EXPORT_SYMBOL(tcp_v4_connect); |
| |
| /* |
| * This routine reacts to ICMP_FRAG_NEEDED mtu indications as defined in RFC1191. |
| * It can be called through tcp_release_cb() if socket was owned by user |
| * at the time tcp_v4_err() was called to handle ICMP message. |
| */ |
| void tcp_v4_mtu_reduced(struct sock *sk) |
| { |
| struct inet_sock *inet = inet_sk(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); |
| dst = inet_csk_update_pmtu(sk, mtu); |
| if (!dst) |
| return; |
| |
| /* Something is about to be wrong... Remember soft error |
| * for the case, if this connection will not able to recover. |
| */ |
| if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst)) |
| WRITE_ONCE(sk->sk_err_soft, EMSGSIZE); |
| |
| mtu = dst_mtu(dst); |
| |
| if (inet->pmtudisc != IP_PMTUDISC_DONT && |
| ip_sk_accept_pmtu(sk) && |
| inet_csk(sk)->icsk_pmtu_cookie > mtu) { |
| tcp_sync_mss(sk, mtu); |
| |
| /* Resend the TCP packet because it's |
| * clear that the old packet has been |
| * dropped. This is the new "fast" path mtu |
| * discovery. |
| */ |
| tcp_simple_retransmit(sk); |
| } /* else let the usual retransmit timer handle it */ |
| } |
| EXPORT_SYMBOL(tcp_v4_mtu_reduced); |
| |
| static void do_redirect(struct sk_buff *skb, struct sock *sk) |
| { |
| struct dst_entry *dst = __sk_dst_check(sk, 0); |
| |
| if (dst) |
| dst->ops->redirect(dst, sk, skb); |
| } |
| |
| |
| /* handle ICMP messages on TCP_NEW_SYN_RECV request sockets */ |
| void tcp_req_err(struct sock *sk, u32 seq, bool abort) |
| { |
| struct request_sock *req = inet_reqsk(sk); |
| struct net *net = sock_net(sk); |
| |
| /* ICMPs are not backlogged, hence we cannot get |
| * an established socket here. |
| */ |
| if (seq != tcp_rsk(req)->snt_isn) { |
| __NET_INC_STATS(net, LINUX_MIB_OUTOFWINDOWICMPS); |
| } else if (abort) { |
| /* |
| * Still in SYN_RECV, just remove it silently. |
| * There is no good way to pass the error to the newly |
| * created socket, and POSIX does not want network |
| * errors returned from accept(). |
| */ |
| inet_csk_reqsk_queue_drop(req->rsk_listener, req); |
| tcp_listendrop(req->rsk_listener); |
| } |
| reqsk_put(req); |
| } |
| EXPORT_SYMBOL(tcp_req_err); |
| |
| /* TCP-LD (RFC 6069) logic */ |
| void tcp_ld_RTO_revert(struct sock *sk, u32 seq) |
| { |
| struct inet_connection_sock *icsk = inet_csk(sk); |
| struct tcp_sock *tp = tcp_sk(sk); |
| struct sk_buff *skb; |
| s32 remaining; |
| u32 delta_us; |
| |
| if (sock_owned_by_user(sk)) |
| return; |
| |
| if (seq != tp->snd_una || !icsk->icsk_retransmits || |
| !icsk->icsk_backoff) |
| return; |
| |
| skb = tcp_rtx_queue_head(sk); |
| if (WARN_ON_ONCE(!skb)) |
| return; |
| |
| icsk->icsk_backoff--; |
| icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) : TCP_TIMEOUT_INIT; |
| icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX); |
| |
| tcp_mstamp_refresh(tp); |
| delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb)); |
| remaining = icsk->icsk_rto - usecs_to_jiffies(delta_us); |
| |
| if (remaining > 0) { |
| inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
| remaining, TCP_RTO_MAX); |
| } else { |
| /* RTO revert clocked out retransmission. |
| * Will retransmit now. |
| */ |
| tcp_retransmit_timer(sk); |
| } |
| } |
| EXPORT_SYMBOL(tcp_ld_RTO_revert); |
| |
| /* |
| * This routine is called by the ICMP module when it gets some |
| * sort of error condition. If err < 0 then the socket should |
| * be closed and the error returned to the user. If err > 0 |
| * it's just the icmp type << 8 | icmp code. After adjustment |
| * header points to the first 8 bytes of the tcp header. We need |
| * to find the appropriate port. |
| * |
| * The locking strategy used here is very "optimistic". When |
| * someone else accesses the socket the ICMP is just dropped |
| * and for some paths there is no check at all. |
| * A more general error queue to queue errors for later handling |
| * is probably better. |
| * |
| */ |
| |
| int tcp_v4_err(struct sk_buff *skb, u32 info) |
| { |
| const struct iphdr *iph = (const struct iphdr *)skb->data; |
| struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2)); |
| struct tcp_sock *tp; |
| const int type = icmp_hdr(skb)->type; |
| const int code = icmp_hdr(skb)->code; |
| struct sock *sk; |
| struct request_sock *fastopen; |
| u32 seq, snd_una; |
| int err; |
| struct net *net = dev_net(skb->dev); |
| |
| sk = __inet_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, |
| iph->daddr, th->dest, iph->saddr, |
| ntohs(th->source), inet_iif(skb), 0); |
| if (!sk) { |
| __ICMP_INC_STATS(net, ICMP_MIB_INERRORS); |
| return -ENOENT; |
| } |
| if (sk->sk_state == TCP_TIME_WAIT) { |
| /* To increase the counter of ignored icmps for TCP-AO */ |
| tcp_ao_ignore_icmp(sk, AF_INET, type, code); |
| inet_twsk_put(inet_twsk(sk)); |
| return 0; |
| } |
| seq = ntohl(th->seq); |
| if (sk->sk_state == TCP_NEW_SYN_RECV) { |
| tcp_req_err(sk, seq, type == ICMP_PARAMETERPROB || |
| type == ICMP_TIME_EXCEEDED || |
| (type == ICMP_DEST_UNREACH && |
| (code == ICMP_NET_UNREACH || |
| code == ICMP_HOST_UNREACH))); |
| return 0; |
| } |
| |
| if (tcp_ao_ignore_icmp(sk, AF_INET, type, code)) { |
| sock_put(sk); |
| return 0; |
| } |
| |
| bh_lock_sock(sk); |
| /* If too many ICMPs get dropped on busy |
| * servers this needs to be solved differently. |
| * We do take care of PMTU discovery (RFC1191) special case : |
| * we can receive locally generated ICMP messages while socket is held. |
| */ |
| if (sock_owned_by_user(sk)) { |
| if (!(type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED)) |
| __NET_INC_STATS(net, LINUX_MIB_LOCKDROPPEDICMPS); |
| } |
| if (sk->sk_state == TCP_CLOSE) |
| goto out; |
| |
| if (static_branch_unlikely(&ip4_min_ttl)) { |
| /* min_ttl can be changed concurrently from do_ip_setsockopt() */ |
| if (unlikely(iph->ttl < READ_ONCE(inet_sk(sk)->min_ttl))) { |
| __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; |
| } |
| |
| switch (type) { |
| case ICMP_REDIRECT: |
| if (!sock_owned_by_user(sk)) |
| do_redirect(skb, sk); |
| goto out; |
| case ICMP_SOURCE_QUENCH: |
| /* Just silently ignore these. */ |
| goto out; |
| case ICMP_PARAMETERPROB: |
| err = EPROTO; |
| break; |
| case ICMP_DEST_UNREACH: |
| if (code > NR_ICMP_UNREACH) |
| goto out; |
| |
| if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */ |
| /* 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; |
| |
| WRITE_ONCE(tp->mtu_info, info); |
| if (!sock_owned_by_user(sk)) { |
| tcp_v4_mtu_reduced(sk); |
| } else { |
| if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED, &sk->sk_tsq_flags)) |
| sock_hold(sk); |
| } |
| goto out; |
| } |
| |
| err = icmp_err_convert[code].errno; |
| /* check if this ICMP message allows revert of backoff. |
| * (see RFC 6069) |
| */ |
| if (!fastopen && |
| (code == ICMP_NET_UNREACH || code == ICMP_HOST_UNREACH)) |
| tcp_ld_RTO_revert(sk, seq); |
| break; |
| case ICMP_TIME_EXCEEDED: |
| err = EHOSTUNREACH; |
| break; |
| default: |
| goto out; |
| } |
| |
| 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; |
| |
| ip_icmp_error(sk, skb, err, th->dest, info, (u8 *)th); |
| |
| if (!sock_owned_by_user(sk)) |
| tcp_done_with_error(sk, err); |
| else |
| WRITE_ONCE(sk->sk_err_soft, err); |
| goto out; |
| } |
| |
| /* If we've already connected we will keep trying |
| * until we time out, or the user gives up. |
| * |
| * rfc1122 4.2.3.9 allows to consider as hard errors |
| * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too, |
| * but it is obsoleted by pmtu discovery). |
| * |
| * Note, that in modern internet, where routing is unreliable |
| * and in each dark corner broken firewalls sit, sending random |
| * errors ordered by their masters even this two messages finally lose |
| * their original sense (even Linux sends invalid PORT_UNREACHs) |
| * |
| * Now we are in compliance with RFCs. |
| * --ANK (980905) |
| */ |
| |
| if (!sock_owned_by_user(sk) && |
| inet_test_bit(RECVERR, sk)) { |
| WRITE_ONCE(sk->sk_err, err); |
| sk_error_report(sk); |
| } else { /* Only an error on timeout */ |
| WRITE_ONCE(sk->sk_err_soft, err); |
| } |
| |
| out: |
| bh_unlock_sock(sk); |
| sock_put(sk); |
| return 0; |
| } |
| |
| void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr) |
| { |
| struct tcphdr *th = tcp_hdr(skb); |
| |
| th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0); |
| skb->csum_start = skb_transport_header(skb) - skb->head; |
| skb->csum_offset = offsetof(struct tcphdr, check); |
| } |
| |
| /* This routine computes an IPv4 TCP checksum. */ |
| void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb) |
| { |
| const struct inet_sock *inet = inet_sk(sk); |
| |
| __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr); |
| } |
| EXPORT_SYMBOL(tcp_v4_send_check); |
| |
| #define REPLY_OPTIONS_LEN (MAX_TCP_OPTION_SPACE / sizeof(__be32)) |
| |
| static bool tcp_v4_ao_sign_reset(const struct sock *sk, struct sk_buff *skb, |
| const struct tcp_ao_hdr *aoh, |
| struct ip_reply_arg *arg, struct tcphdr *reply, |
| __be32 reply_options[REPLY_OPTIONS_LEN]) |
| { |
| #ifdef CONFIG_TCP_AO |
| int sdif = tcp_v4_sdif(skb); |
| int dif = inet_iif(skb); |
| int l3index = sdif ? dif : 0; |
| bool allocated_traffic_key; |
| struct tcp_ao_key *key; |
| char *traffic_key; |
| bool drop = true; |
| u32 ao_sne = 0; |
| u8 keyid; |
| |
| rcu_read_lock(); |
| if (tcp_ao_prepare_reset(sk, skb, aoh, l3index, ntohl(reply->seq), |
| &key, &traffic_key, &allocated_traffic_key, |
| &keyid, &ao_sne)) |
| goto out; |
| |
| reply_options[0] = htonl((TCPOPT_AO << 24) | (tcp_ao_len(key) << 16) | |
| (aoh->rnext_keyid << 8) | keyid); |
| arg->iov[0].iov_len += tcp_ao_len_aligned(key); |
| reply->doff = arg->iov[0].iov_len / 4; |
| |
| if (tcp_ao_hash_hdr(AF_INET, (char *)&reply_options[1], |
| key, traffic_key, |
| (union tcp_ao_addr *)&ip_hdr(skb)->saddr, |
| (union tcp_ao_addr *)&ip_hdr(skb)->daddr, |
| reply, ao_sne)) |
| goto out; |
| drop = false; |
| out: |
| rcu_read_unlock(); |
| if (allocated_traffic_key) |
| kfree(traffic_key); |
| return drop; |
| #else |
| return true; |
| #endif |
| } |
| |
| /* |
| * This routine will send an RST to the other tcp. |
| * |
| * Someone asks: why I NEVER use socket parameters (TOS, TTL etc.) |
| * for reset. |
| * Answer: if a packet caused RST, it is not for a socket |
| * existing in our system, if it is matched to a socket, |
| * it is just duplicate segment or bug in other side's TCP. |
| * So that we build reply only basing on parameters |
| * arrived with segment. |
| * Exception: precedence violation. We do not implement it in any case. |
| */ |
| |
| static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb, |
| enum sk_rst_reason reason) |
| { |
| const struct tcphdr *th = tcp_hdr(skb); |
| struct { |
| struct tcphdr th; |
| __be32 opt[REPLY_OPTIONS_LEN]; |
| } rep; |
| const __u8 *md5_hash_location = NULL; |
| const struct tcp_ao_hdr *aoh; |
| struct ip_reply_arg arg; |
| #ifdef CONFIG_TCP_MD5SIG |
| struct tcp_md5sig_key *key = NULL; |
| unsigned char newhash[16]; |
| struct sock *sk1 = NULL; |
| int genhash; |
| #endif |
| u64 transmit_time = 0; |
| struct sock *ctl_sk; |
| struct net *net; |
| u32 txhash = 0; |
| |
| /* Never send a reset in response to a reset. */ |
| 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 && skb_rtable(skb)->rt_type != RTN_LOCAL) |
| return; |
| |
| /* Swap the send and the receive. */ |
| memset(&rep, 0, sizeof(rep)); |
| rep.th.dest = th->source; |
| rep.th.source = th->dest; |
| rep.th.doff = sizeof(struct tcphdr) / 4; |
| rep.th.rst = 1; |
| |
| if (th->ack) { |
| rep.th.seq = th->ack_seq; |
| } else { |
| rep.th.ack = 1; |
| rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin + |
| skb->len - (th->doff << 2)); |
| } |
| |
| memset(&arg, 0, sizeof(arg)); |
| arg.iov[0].iov_base = (unsigned char *)&rep; |
| arg.iov[0].iov_len = sizeof(rep.th); |
| |
| net = sk ? sock_net(sk) : dev_net(skb_dst(skb)->dev); |
| |
| /* Invalid TCP option size or twice included auth */ |
| if (tcp_parse_auth_options(tcp_hdr(skb), &md5_hash_location, &aoh)) |
| return; |
| |
| if (aoh && tcp_v4_ao_sign_reset(sk, skb, aoh, &arg, &rep.th, rep.opt)) |
| return; |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| rcu_read_lock(); |
| if (sk && sk_fullsock(sk)) { |
| const union tcp_md5_addr *addr; |
| int l3index; |
| |
| /* sdif set, means packet ingressed via a device |
| * in an L3 domain and inet_iif is set to it. |
| */ |
| l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; |
| addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
| key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
| } else if (md5_hash_location) { |
| const union tcp_md5_addr *addr; |
| int sdif = tcp_v4_sdif(skb); |
| int dif = inet_iif(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 = __inet_lookup_listener(net, net->ipv4.tcp_death_row.hashinfo, |
| NULL, 0, ip_hdr(skb)->saddr, |
| th->source, ip_hdr(skb)->daddr, |
| ntohs(th->source), dif, sdif); |
| /* don't send rst if it can't find key */ |
| if (!sk1) |
| goto out; |
| |
| /* sdif set, means packet ingressed via a device |
| * in an L3 domain and dif is set to it. |
| */ |
| l3index = sdif ? dif : 0; |
| addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
| key = tcp_md5_do_lookup(sk1, l3index, addr, AF_INET); |
| if (!key) |
| goto out; |
| |
| |
| genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb); |
| if (genhash || memcmp(md5_hash_location, newhash, 16) != 0) |
| goto out; |
| |
| } |
| |
| if (key) { |
| rep.opt[0] = htonl((TCPOPT_NOP << 24) | |
| (TCPOPT_NOP << 16) | |
| (TCPOPT_MD5SIG << 8) | |
| TCPOLEN_MD5SIG); |
| /* Update length and the length the header thinks exists */ |
| arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; |
| rep.th.doff = arg.iov[0].iov_len / 4; |
| |
| tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[1], |
| key, ip_hdr(skb)->saddr, |
| ip_hdr(skb)->daddr, &rep.th); |
| } |
| #endif |
| /* Can't co-exist with TCPMD5, hence check rep.opt[0] */ |
| if (rep.opt[0] == 0) { |
| __be32 mrst = mptcp_reset_option(skb); |
| |
| if (mrst) { |
| rep.opt[0] = mrst; |
| arg.iov[0].iov_len += sizeof(mrst); |
| rep.th.doff = arg.iov[0].iov_len / 4; |
| } |
| } |
| |
| arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
| ip_hdr(skb)->saddr, /* XXX */ |
| arg.iov[0].iov_len, IPPROTO_TCP, 0); |
| arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
| arg.flags = (sk && inet_sk_transparent(sk)) ? IP_REPLY_ARG_NOSRCCHECK : 0; |
| |
| /* When socket is gone, all binding information is lost. |
| * routing might fail in this case. No choice here, if we choose to force |
| * input interface, we will misroute in case of asymmetric route. |
| */ |
| if (sk) |
| arg.bound_dev_if = sk->sk_bound_dev_if; |
| |
| trace_tcp_send_reset(sk, skb, reason); |
| |
| BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) != |
| offsetof(struct inet_timewait_sock, tw_bound_dev_if)); |
| |
| arg.tos = ip_hdr(skb)->tos; |
| arg.uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL); |
| local_bh_disable(); |
| local_lock_nested_bh(&ipv4_tcp_sk.bh_lock); |
| ctl_sk = this_cpu_read(ipv4_tcp_sk.sock); |
| |
| sock_net_set(ctl_sk, net); |
| if (sk) { |
| ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? |
| inet_twsk(sk)->tw_mark : sk->sk_mark; |
| ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? |
| inet_twsk(sk)->tw_priority : READ_ONCE(sk->sk_priority); |
| transmit_time = tcp_transmit_time(sk); |
| xfrm_sk_clone_policy(ctl_sk, sk); |
| txhash = (sk->sk_state == TCP_TIME_WAIT) ? |
| inet_twsk(sk)->tw_txhash : sk->sk_txhash; |
| } else { |
| ctl_sk->sk_mark = 0; |
| ctl_sk->sk_priority = 0; |
| } |
| ip_send_unicast_reply(ctl_sk, |
| skb, &TCP_SKB_CB(skb)->header.h4.opt, |
| ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
| &arg, arg.iov[0].iov_len, |
| transmit_time, txhash); |
| |
| xfrm_sk_free_policy(ctl_sk); |
| sock_net_set(ctl_sk, &init_net); |
| __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
| __TCP_INC_STATS(net, TCP_MIB_OUTRSTS); |
| local_unlock_nested_bh(&ipv4_tcp_sk.bh_lock); |
| local_bh_enable(); |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| out: |
| rcu_read_unlock(); |
| #endif |
| } |
| |
| /* The code following below sending ACKs in SYN-RECV and TIME-WAIT states |
| outside socket context is ugly, certainly. What can I do? |
| */ |
| |
| static void tcp_v4_send_ack(const struct sock *sk, |
| struct sk_buff *skb, u32 seq, u32 ack, |
| u32 win, u32 tsval, u32 tsecr, int oif, |
| struct tcp_key *key, |
| int reply_flags, u8 tos, u32 txhash) |
| { |
| const struct tcphdr *th = tcp_hdr(skb); |
| struct { |
| struct tcphdr th; |
| __be32 opt[(MAX_TCP_OPTION_SPACE >> 2)]; |
| } rep; |
| struct net *net = sock_net(sk); |
| struct ip_reply_arg arg; |
| struct sock *ctl_sk; |
| u64 transmit_time; |
| |
| memset(&rep.th, 0, sizeof(struct tcphdr)); |
| memset(&arg, 0, sizeof(arg)); |
| |
| arg.iov[0].iov_base = (unsigned char *)&rep; |
| arg.iov[0].iov_len = sizeof(rep.th); |
| if (tsecr) { |
| rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
| (TCPOPT_TIMESTAMP << 8) | |
| TCPOLEN_TIMESTAMP); |
| rep.opt[1] = htonl(tsval); |
| rep.opt[2] = htonl(tsecr); |
| arg.iov[0].iov_len += TCPOLEN_TSTAMP_ALIGNED; |
| } |
| |
| /* Swap the send and the receive. */ |
| rep.th.dest = th->source; |
| rep.th.source = th->dest; |
| rep.th.doff = arg.iov[0].iov_len / 4; |
| rep.th.seq = htonl(seq); |
| rep.th.ack_seq = htonl(ack); |
| rep.th.ack = 1; |
| rep.th.window = htons(win); |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| if (tcp_key_is_md5(key)) { |
| int offset = (tsecr) ? 3 : 0; |
| |
| rep.opt[offset++] = htonl((TCPOPT_NOP << 24) | |
| (TCPOPT_NOP << 16) | |
| (TCPOPT_MD5SIG << 8) | |
| TCPOLEN_MD5SIG); |
| arg.iov[0].iov_len += TCPOLEN_MD5SIG_ALIGNED; |
| rep.th.doff = arg.iov[0].iov_len/4; |
| |
| tcp_v4_md5_hash_hdr((__u8 *) &rep.opt[offset], |
| key->md5_key, ip_hdr(skb)->saddr, |
| ip_hdr(skb)->daddr, &rep.th); |
| } |
| #endif |
| #ifdef CONFIG_TCP_AO |
| if (tcp_key_is_ao(key)) { |
| int offset = (tsecr) ? 3 : 0; |
| |
| rep.opt[offset++] = htonl((TCPOPT_AO << 24) | |
| (tcp_ao_len(key->ao_key) << 16) | |
| (key->ao_key->sndid << 8) | |
| key->rcv_next); |
| arg.iov[0].iov_len += tcp_ao_len_aligned(key->ao_key); |
| rep.th.doff = arg.iov[0].iov_len / 4; |
| |
| tcp_ao_hash_hdr(AF_INET, (char *)&rep.opt[offset], |
| key->ao_key, key->traffic_key, |
| (union tcp_ao_addr *)&ip_hdr(skb)->saddr, |
| (union tcp_ao_addr *)&ip_hdr(skb)->daddr, |
| &rep.th, key->sne); |
| } |
| #endif |
| arg.flags = reply_flags; |
| arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr, |
| ip_hdr(skb)->saddr, /* XXX */ |
| arg.iov[0].iov_len, IPPROTO_TCP, 0); |
| arg.csumoffset = offsetof(struct tcphdr, check) / 2; |
| if (oif) |
| arg.bound_dev_if = oif; |
| arg.tos = tos; |
| arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL); |
| local_bh_disable(); |
| local_lock_nested_bh(&ipv4_tcp_sk.bh_lock); |
| ctl_sk = this_cpu_read(ipv4_tcp_sk.sock); |
| sock_net_set(ctl_sk, net); |
| ctl_sk->sk_mark = (sk->sk_state == TCP_TIME_WAIT) ? |
| inet_twsk(sk)->tw_mark : READ_ONCE(sk->sk_mark); |
| ctl_sk->sk_priority = (sk->sk_state == TCP_TIME_WAIT) ? |
| inet_twsk(sk)->tw_priority : READ_ONCE(sk->sk_priority); |
| transmit_time = tcp_transmit_time(sk); |
| ip_send_unicast_reply(ctl_sk, |
| skb, &TCP_SKB_CB(skb)->header.h4.opt, |
| ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
| &arg, arg.iov[0].iov_len, |
| transmit_time, txhash); |
| |
| sock_net_set(ctl_sk, &init_net); |
| __TCP_INC_STATS(net, TCP_MIB_OUTSEGS); |
| local_unlock_nested_bh(&ipv4_tcp_sk.bh_lock); |
| local_bh_enable(); |
| } |
| |
| static void tcp_v4_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); |
| struct tcp_key key = {}; |
| #ifdef CONFIG_TCP_AO |
| struct tcp_ao_info *ao_info; |
| |
| if (static_branch_unlikely(&tcp_ao_needed.key)) { |
| /* FIXME: the segment to-be-acked is not verified yet */ |
| ao_info = rcu_dereference(tcptw->ao_info); |
| if (ao_info) { |
| const struct tcp_ao_hdr *aoh; |
| |
| if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) { |
| inet_twsk_put(tw); |
| return; |
| } |
| |
| if (aoh) |
| key.ao_key = tcp_ao_established_key(ao_info, aoh->rnext_keyid, -1); |
| } |
| } |
| if (key.ao_key) { |
| struct tcp_ao_key *rnext_key; |
| |
| key.traffic_key = snd_other_key(key.ao_key); |
| key.sne = READ_ONCE(ao_info->snd_sne); |
| rnext_key = READ_ONCE(ao_info->rnext_key); |
| key.rcv_next = rnext_key->rcvid; |
| key.type = TCP_KEY_AO; |
| #else |
| if (0) { |
| #endif |
| } else if (static_branch_tcp_md5()) { |
| key.md5_key = tcp_twsk_md5_key(tcptw); |
| if (key.md5_key) |
| key.type = TCP_KEY_MD5; |
| } |
| |
| tcp_v4_send_ack(sk, skb, |
| tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
| tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
| tcp_tw_tsval(tcptw), |
| READ_ONCE(tcptw->tw_ts_recent), |
| tw->tw_bound_dev_if, &key, |
| tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, |
| tw->tw_tos, |
| tw->tw_txhash); |
| |
| inet_twsk_put(tw); |
| } |
| |
| static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
| struct request_sock *req) |
| { |
| struct tcp_key key = {}; |
| |
| /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV |
| * sk->sk_state == TCP_SYN_RECV -> for Fast Open. |
| */ |
| u32 seq = (sk->sk_state == TCP_LISTEN) ? tcp_rsk(req)->snt_isn + 1 : |
| tcp_sk(sk)->snd_nxt; |
| |
| #ifdef CONFIG_TCP_AO |
| if (static_branch_unlikely(&tcp_ao_needed.key) && |
| tcp_rsk_used_ao(req)) { |
| const union tcp_md5_addr *addr; |
| const struct tcp_ao_hdr *aoh; |
| int l3index; |
| |
| /* Invalid TCP option size or twice included auth */ |
| if (tcp_parse_auth_options(tcp_hdr(skb), NULL, &aoh)) |
| return; |
| if (!aoh) |
| return; |
| |
| addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
| l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; |
| key.ao_key = tcp_ao_do_lookup(sk, l3index, addr, AF_INET, |
| aoh->rnext_keyid, -1); |
| if (unlikely(!key.ao_key)) { |
| /* Send ACK with any matching MKT for the peer */ |
| key.ao_key = tcp_ao_do_lookup(sk, l3index, addr, AF_INET, -1, -1); |
| /* Matching key disappeared (user removed the key?) |
| * let the handshake timeout. |
| */ |
| if (!key.ao_key) { |
| net_info_ratelimited("TCP-AO key for (%pI4, %d)->(%pI4, %d) suddenly disappeared, won't ACK new connection\n", |
| addr, |
| ntohs(tcp_hdr(skb)->source), |
| &ip_hdr(skb)->daddr, |
| ntohs(tcp_hdr(skb)->dest)); |
| return; |
| } |
| } |
| key.traffic_key = kmalloc(tcp_ao_digest_size(key.ao_key), GFP_ATOMIC); |
| if (!key.traffic_key) |
| return; |
| |
| key.type = TCP_KEY_AO; |
| key.rcv_next = aoh->keyid; |
| tcp_v4_ao_calc_key_rsk(key.ao_key, key.traffic_key, req); |
| #else |
| if (0) { |
| #endif |
| } else if (static_branch_tcp_md5()) { |
| const union tcp_md5_addr *addr; |
| int l3index; |
| |
| addr = (union tcp_md5_addr *)&ip_hdr(skb)->saddr; |
| l3index = tcp_v4_sdif(skb) ? inet_iif(skb) : 0; |
| key.md5_key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
| if (key.md5_key) |
| key.type = TCP_KEY_MD5; |
| } |
| |
| tcp_v4_send_ack(sk, skb, seq, |
| tcp_rsk(req)->rcv_nxt, |
| tcp_synack_window(req) >> inet_rsk(req)->rcv_wscale, |
| tcp_rsk_tsval(tcp_rsk(req)), |
| READ_ONCE(req->ts_recent), |
| 0, &key, |
| inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0, |
| ip_hdr(skb)->tos, |
| READ_ONCE(tcp_rsk(req)->txhash)); |
| if (tcp_key_is_ao(&key)) |
| kfree(key.traffic_key); |
| } |
| |
| /* |
| * Send a SYN-ACK after having received a SYN. |
| * This still operates on a request_sock only, not on a big |
| * socket. |
| */ |
| static int tcp_v4_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) |
| { |
| const struct inet_request_sock *ireq = inet_rsk(req); |
| struct flowi4 fl4; |
| int err = -1; |
| struct sk_buff *skb; |
| u8 tos; |
| |
| /* First, grab a route. */ |
| if (!dst && (dst = inet_csk_route_req(sk, &fl4, req)) == NULL) |
| return -1; |
| |
| skb = tcp_make_synack(sk, dst, req, foc, synack_type, syn_skb); |
| |
| if (skb) { |
| __tcp_v4_send_check(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr); |
| |
| tos = READ_ONCE(inet_sk(sk)->tos); |
| |
| if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)) |
| tos = (tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) | |
| (tos & INET_ECN_MASK); |
| |
| if (!INET_ECN_is_capable(tos) && |
| tcp_bpf_ca_needs_ecn((struct sock *)req)) |
| tos |= INET_ECN_ECT_0; |
| |
| rcu_read_lock(); |
| err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, |
| ireq->ir_rmt_addr, |
| rcu_dereference(ireq->ireq_opt), |
| tos); |
| rcu_read_unlock(); |
| err = net_xmit_eval(err); |
| } |
| |
| return err; |
| } |
| |
| /* |
| * IPv4 request_sock destructor. |
| */ |
| static void tcp_v4_reqsk_destructor(struct request_sock *req) |
| { |
| kfree(rcu_dereference_protected(inet_rsk(req)->ireq_opt, 1)); |
| } |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| /* |
| * RFC2385 MD5 checksumming requires a mapping of |
| * IP address->MD5 Key. |
| * We need to maintain these in the sk structure. |
| */ |
| |
| DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_md5_needed, HZ); |
| EXPORT_SYMBOL(tcp_md5_needed); |
| |
| static bool better_md5_match(struct tcp_md5sig_key *old, struct tcp_md5sig_key *new) |
| { |
| if (!old) |
| return true; |
| |
| /* l3index always overrides non-l3index */ |
| if (old->l3index && new->l3index == 0) |
| return false; |
| if (old->l3index == 0 && new->l3index) |
| return true; |
| |
| return old->prefixlen < new->prefixlen; |
| } |
| |
| /* Find the Key structure for an address. */ |
| struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, |
| const union tcp_md5_addr *addr, |
| int family, bool any_l3index) |
| { |
| const struct tcp_sock *tp = tcp_sk(sk); |
| struct tcp_md5sig_key *key; |
| const struct tcp_md5sig_info *md5sig; |
| __be32 mask; |
| struct tcp_md5sig_key *best_match = NULL; |
| bool match; |
| |
| /* caller either holds rcu_read_lock() or socket lock */ |
| md5sig = rcu_dereference_check(tp->md5sig_info, |
| lockdep_sock_is_held(sk)); |
| if (!md5sig) |
| return NULL; |
| |
| hlist_for_each_entry_rcu(key, &md5sig->head, node, |
| lockdep_sock_is_held(sk)) { |
| if (key->family != family) |
| continue; |
| if (!any_l3index && key->flags & TCP_MD5SIG_FLAG_IFINDEX && |
| key->l3index != l3index) |
| continue; |
| if (family == AF_INET) { |
| mask = inet_make_mask(key->prefixlen); |
| match = (key->addr.a4.s_addr & mask) == |
| (addr->a4.s_addr & mask); |
| #if IS_ENABLED(CONFIG_IPV6) |
| } else if (family == AF_INET6) { |
| match = ipv6_prefix_equal(&key->addr.a6, &addr->a6, |
| key->prefixlen); |
| #endif |
| } else { |
| match = false; |
| } |
| |
| if (match && better_md5_match(best_match, key)) |
| best_match = key; |
| } |
| return best_match; |
| } |
| EXPORT_SYMBOL(__tcp_md5_do_lookup); |
| |
| static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk, |
| const union tcp_md5_addr *addr, |
| int family, u8 prefixlen, |
| int l3index, u8 flags) |
| { |
| const struct tcp_sock *tp = tcp_sk(sk); |
| struct tcp_md5sig_key *key; |
| unsigned int size = sizeof(struct in_addr); |
| const struct tcp_md5sig_info *md5sig; |
| |
| /* caller either holds rcu_read_lock() or socket lock */ |
| md5sig = rcu_dereference_check(tp->md5sig_info, |
| lockdep_sock_is_held(sk)); |
| if (!md5sig) |
| return NULL; |
| #if IS_ENABLED(CONFIG_IPV6) |
| if (family == AF_INET6) |
| size = sizeof(struct in6_addr); |
| #endif |
| hlist_for_each_entry_rcu(key, &md5sig->head, node, |
| lockdep_sock_is_held(sk)) { |
| if (key->family != family) |
| continue; |
| if ((key->flags & TCP_MD5SIG_FLAG_IFINDEX) != (flags & TCP_MD5SIG_FLAG_IFINDEX)) |
| continue; |
| if (key->l3index != l3index) |
| continue; |
| if (!memcmp(&key->addr, addr, size) && |
| key->prefixlen == prefixlen) |
| return key; |
| } |
| return NULL; |
| } |
| |
| struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
| const struct sock *addr_sk) |
| { |
| const union tcp_md5_addr *addr; |
| int l3index; |
| |
| l3index = l3mdev_master_ifindex_by_index(sock_net(sk), |
| addr_sk->sk_bound_dev_if); |
| addr = (const union tcp_md5_addr *)&addr_sk->sk_daddr; |
| return tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
| } |
| EXPORT_SYMBOL(tcp_v4_md5_lookup); |
| |
| static int tcp_md5sig_info_add(struct sock *sk, gfp_t gfp) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| struct tcp_md5sig_info *md5sig; |
| |
| md5sig = kmalloc(sizeof(*md5sig), gfp); |
| if (!md5sig) |
| return -ENOMEM; |
| |
| sk_gso_disable(sk); |
| INIT_HLIST_HEAD(&md5sig->head); |
| rcu_assign_pointer(tp->md5sig_info, md5sig); |
| return 0; |
| } |
| |
| /* This can be called on a newly created socket, from other files */ |
| static int __tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
| int family, u8 prefixlen, int l3index, u8 flags, |
| const u8 *newkey, u8 newkeylen, gfp_t gfp) |
| { |
| /* Add Key to the list */ |
| struct tcp_md5sig_key *key; |
| struct tcp_sock *tp = tcp_sk(sk); |
| struct tcp_md5sig_info *md5sig; |
| |
| key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index, flags); |
| if (key) { |
| /* Pre-existing entry - just update that one. |
| * Note that the key might be used concurrently. |
| * data_race() is telling kcsan that we do not care of |
| * key mismatches, since changing MD5 key on live flows |
| * can lead to packet drops. |
| */ |
| data_race(memcpy(key->key, newkey, newkeylen)); |
| |
| /* Pairs with READ_ONCE() in tcp_md5_hash_key(). |
| * Also note that a reader could catch new key->keylen value |
| * but old key->key[], this is the reason we use __GFP_ZERO |
| * at sock_kmalloc() time below these lines. |
| */ |
| WRITE_ONCE(key->keylen, newkeylen); |
| |
| return 0; |
| } |
| |
| md5sig = rcu_dereference_protected(tp->md5sig_info, |
| lockdep_sock_is_held(sk)); |
| |
| key = sock_kmalloc(sk, sizeof(*key), gfp | __GFP_ZERO); |
| if (!key) |
| return -ENOMEM; |
| |
| memcpy(key->key, newkey, newkeylen); |
| key->keylen = newkeylen; |
| key->family = family; |
| key->prefixlen = prefixlen; |
| key->l3index = l3index; |
| key->flags = flags; |
| memcpy(&key->addr, addr, |
| (IS_ENABLED(CONFIG_IPV6) && family == AF_INET6) ? sizeof(struct in6_addr) : |
| sizeof(struct in_addr)); |
| hlist_add_head_rcu(&key->node, &md5sig->head); |
| return 0; |
| } |
| |
| int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
| int family, u8 prefixlen, int l3index, u8 flags, |
| const u8 *newkey, u8 newkeylen) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) { |
| if (tcp_md5_alloc_sigpool()) |
| return -ENOMEM; |
| |
| if (tcp_md5sig_info_add(sk, GFP_KERNEL)) { |
| tcp_md5_release_sigpool(); |
| return -ENOMEM; |
| } |
| |
| if (!static_branch_inc(&tcp_md5_needed.key)) { |
| struct tcp_md5sig_info *md5sig; |
| |
| md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk)); |
| rcu_assign_pointer(tp->md5sig_info, NULL); |
| kfree_rcu(md5sig, rcu); |
| tcp_md5_release_sigpool(); |
| return -EUSERS; |
| } |
| } |
| |
| return __tcp_md5_do_add(sk, addr, family, prefixlen, l3index, flags, |
| newkey, newkeylen, GFP_KERNEL); |
| } |
| EXPORT_SYMBOL(tcp_md5_do_add); |
| |
| int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, |
| int family, u8 prefixlen, int l3index, |
| struct tcp_md5sig_key *key) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| if (!rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk))) { |
| tcp_md5_add_sigpool(); |
| |
| if (tcp_md5sig_info_add(sk, sk_gfp_mask(sk, GFP_ATOMIC))) { |
| tcp_md5_release_sigpool(); |
| return -ENOMEM; |
| } |
| |
| if (!static_key_fast_inc_not_disabled(&tcp_md5_needed.key.key)) { |
| struct tcp_md5sig_info *md5sig; |
| |
| md5sig = rcu_dereference_protected(tp->md5sig_info, lockdep_sock_is_held(sk)); |
| net_warn_ratelimited("Too many TCP-MD5 keys in the system\n"); |
| rcu_assign_pointer(tp->md5sig_info, NULL); |
| kfree_rcu(md5sig, rcu); |
| tcp_md5_release_sigpool(); |
| return -EUSERS; |
| } |
| } |
| |
| return __tcp_md5_do_add(sk, addr, family, prefixlen, l3index, |
| key->flags, key->key, key->keylen, |
| sk_gfp_mask(sk, GFP_ATOMIC)); |
| } |
| EXPORT_SYMBOL(tcp_md5_key_copy); |
| |
| int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family, |
| u8 prefixlen, int l3index, u8 flags) |
| { |
| struct tcp_md5sig_key *key; |
| |
| key = tcp_md5_do_lookup_exact(sk, addr, family, prefixlen, l3index, flags); |
| if (!key) |
| return -ENOENT; |
| hlist_del_rcu(&key->node); |
| atomic_sub(sizeof(*key), &sk->sk_omem_alloc); |
| kfree_rcu(key, rcu); |
| return 0; |
| } |
| EXPORT_SYMBOL(tcp_md5_do_del); |
| |
| void tcp_clear_md5_list(struct sock *sk) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| struct tcp_md5sig_key *key; |
| struct hlist_node *n; |
| struct tcp_md5sig_info *md5sig; |
| |
| md5sig = rcu_dereference_protected(tp->md5sig_info, 1); |
| |
| hlist_for_each_entry_safe(key, n, &md5sig->head, node) { |
| hlist_del_rcu(&key->node); |
| atomic_sub(sizeof(*key), &sk->sk_omem_alloc); |
| kfree_rcu(key, rcu); |
| } |
| } |
| |
| static int tcp_v4_parse_md5_keys(struct sock *sk, int optname, |
| sockptr_t optval, int optlen) |
| { |
| struct tcp_md5sig cmd; |
| struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; |
| const union tcp_md5_addr *addr; |
| u8 prefixlen = 32; |
| int l3index = 0; |
| bool l3flag; |
| u8 flags; |
| |
| if (optlen < sizeof(cmd)) |
| return -EINVAL; |
| |
| if (copy_from_sockptr(&cmd, optval, sizeof(cmd))) |
| return -EFAULT; |
| |
| if (sin->sin_family != AF_INET) |
| return -EINVAL; |
| |
| flags = cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX; |
| l3flag = 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 > 32) |
| return -EINVAL; |
| } |
| |
| 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; |
| } |
| |
| addr = (union tcp_md5_addr *)&sin->sin_addr.s_addr; |
| |
| if (!cmd.tcpm_keylen) |
| return tcp_md5_do_del(sk, addr, AF_INET, prefixlen, l3index, flags); |
| |
| if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) |
| return -EINVAL; |
| |
| /* Don't allow keys for peers that have a matching TCP-AO key. |
| * See the comment in tcp_ao_add_cmd() |
| */ |
| if (tcp_ao_required(sk, addr, AF_INET, l3flag ? l3index : -1, false)) |
| return -EKEYREJECTED; |
| |
| return tcp_md5_do_add(sk, addr, AF_INET, prefixlen, l3index, flags, |
| cmd.tcpm_key, cmd.tcpm_keylen); |
| } |
| |
| static int tcp_v4_md5_hash_headers(struct tcp_sigpool *hp, |
| __be32 daddr, __be32 saddr, |
| const struct tcphdr *th, int nbytes) |
| { |
| struct tcp4_pseudohdr *bp; |
| struct scatterlist sg; |
| struct tcphdr *_th; |
| |
| bp = hp->scratch; |
| bp->saddr = saddr; |
| bp->daddr = daddr; |
| bp->pad = 0; |
| bp->protocol = IPPROTO_TCP; |
| bp->len = cpu_to_be16(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->req, &sg, NULL, |
| sizeof(*bp) + sizeof(*th)); |
| return crypto_ahash_update(hp->req); |
| } |
| |
| static int tcp_v4_md5_hash_hdr(char *md5_hash, const struct tcp_md5sig_key *key, |
| __be32 daddr, __be32 saddr, const struct tcphdr *th) |
| { |
| struct tcp_sigpool hp; |
| |
| if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp)) |
| goto clear_hash_nostart; |
| |
| if (crypto_ahash_init(hp.req)) |
| goto clear_hash; |
| if (tcp_v4_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(hp.req, NULL, md5_hash, 0); |
| if (crypto_ahash_final(hp.req)) |
| goto clear_hash; |
| |
| tcp_sigpool_end(&hp); |
| return 0; |
| |
| clear_hash: |
| tcp_sigpool_end(&hp); |
| clear_hash_nostart: |
| memset(md5_hash, 0, 16); |
| return 1; |
| } |
| |
| int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
| const struct sock *sk, |
| const struct sk_buff *skb) |
| { |
| const struct tcphdr *th = tcp_hdr(skb); |
| struct tcp_sigpool hp; |
| __be32 saddr, daddr; |
| |
| if (sk) { /* valid for establish/request sockets */ |
| saddr = sk->sk_rcv_saddr; |
| daddr = sk->sk_daddr; |
| } else { |
| const struct iphdr *iph = ip_hdr(skb); |
| saddr = iph->saddr; |
| daddr = iph->daddr; |
| } |
| |
| if (tcp_sigpool_start(tcp_md5_sigpool_id, &hp)) |
| goto clear_hash_nostart; |
| |
| if (crypto_ahash_init(hp.req)) |
| goto clear_hash; |
| |
| if (tcp_v4_md5_hash_headers(&hp, daddr, saddr, th, skb->len)) |
| goto clear_hash; |
| if (tcp_sigpool_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(hp.req, NULL, md5_hash, 0); |
| if (crypto_ahash_final(hp.req)) |
| goto clear_hash; |
| |
| tcp_sigpool_end(&hp); |
| return 0; |
| |
| clear_hash: |
| tcp_sigpool_end(&hp); |
| clear_hash_nostart: |
| memset(md5_hash, 0, 16); |
| return 1; |
| } |
| EXPORT_SYMBOL(tcp_v4_md5_hash_skb); |
| |
| #endif |
| |
| static void tcp_v4_init_req(struct request_sock *req, |
| const struct sock *sk_listener, |
| struct sk_buff *skb) |
| { |
| struct inet_request_sock *ireq = inet_rsk(req); |
| struct net *net = sock_net(sk_listener); |
| |
| sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); |
| sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); |
| RCU_INIT_POINTER(ireq->ireq_opt, tcp_v4_save_options(net, skb)); |
| } |
| |
| static struct dst_entry *tcp_v4_route_req(const struct sock *sk, |
| struct sk_buff *skb, |
| struct flowi *fl, |
| struct request_sock *req, |
| u32 tw_isn) |
| { |
| tcp_v4_init_req(req, sk, skb); |
| |
| if (security_inet_conn_request(sk, skb, req)) |
| return NULL; |
| |
| return inet_csk_route_req(sk, &fl->u.ip4, req); |
| } |
| |
| struct request_sock_ops tcp_request_sock_ops __read_mostly = { |
| .family = PF_INET, |
| .obj_size = sizeof(struct tcp_request_sock), |
| .rtx_syn_ack = tcp_rtx_synack, |
| .send_ack = tcp_v4_reqsk_send_ack, |
| .destructor = tcp_v4_reqsk_destructor, |
| .send_reset = tcp_v4_send_reset, |
| .syn_ack_timeout = tcp_syn_ack_timeout, |
| }; |
| |
| const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = { |
| .mss_clamp = TCP_MSS_DEFAULT, |
| #ifdef CONFIG_TCP_MD5SIG |
| .req_md5_lookup = tcp_v4_md5_lookup, |
| .calc_md5_hash = tcp_v4_md5_hash_skb, |
| #endif |
| #ifdef CONFIG_TCP_AO |
| .ao_lookup = tcp_v4_ao_lookup_rsk, |
| .ao_calc_key = tcp_v4_ao_calc_key_rsk, |
| .ao_synack_hash = tcp_v4_ao_synack_hash, |
| #endif |
| #ifdef CONFIG_SYN_COOKIES |
| .cookie_init_seq = cookie_v4_init_sequence, |
| #endif |
| .route_req = tcp_v4_route_req, |
| .init_seq = tcp_v4_init_seq, |
| .init_ts_off = tcp_v4_init_ts_off, |
| .send_synack = tcp_v4_send_synack, |
| }; |
| |
| int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb) |
| { |
| /* Never answer to SYNs send to broadcast or multicast */ |
| if (skb_rtable(skb)->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) |
| goto drop; |
| |
| return tcp_conn_request(&tcp_request_sock_ops, |
| &tcp_request_sock_ipv4_ops, sk, skb); |
| |
| drop: |
| tcp_listendrop(sk); |
| return 0; |
| } |
| EXPORT_SYMBOL(tcp_v4_conn_request); |
| |
| |
| /* |
| * The three way handshake has completed - we got a valid synack - |
| * now create the new socket. |
| */ |
| struct sock *tcp_v4_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; |
| bool found_dup_sk = false; |
| struct inet_sock *newinet; |
| struct tcp_sock *newtp; |
| struct sock *newsk; |
| #ifdef CONFIG_TCP_MD5SIG |
| const union tcp_md5_addr *addr; |
| struct tcp_md5sig_key *key; |
| int l3index; |
| #endif |
| struct ip_options_rcu *inet_opt; |
| |
| if (sk_acceptq_is_full(sk)) |
| goto exit_overflow; |
| |
| newsk = tcp_create_openreq_child(sk, req, skb); |
| if (!newsk) |
| goto exit_nonewsk; |
| |
| newsk->sk_gso_type = SKB_GSO_TCPV4; |
| inet_sk_rx_dst_set(newsk, skb); |
| |
| newtp = tcp_sk(newsk); |
| newinet = inet_sk(newsk); |
| ireq = inet_rsk(req); |
| sk_daddr_set(newsk, ireq->ir_rmt_addr); |
| sk_rcv_saddr_set(newsk, ireq->ir_loc_addr); |
| newsk->sk_bound_dev_if = ireq->ir_iif; |
| newinet->inet_saddr = ireq->ir_loc_addr; |
| inet_opt = rcu_dereference(ireq->ireq_opt); |
| RCU_INIT_POINTER(newinet->inet_opt, inet_opt); |
| newinet->mc_index = inet_iif(skb); |
| newinet->mc_ttl = ip_hdr(skb)->ttl; |
| newinet->rcv_tos = ip_hdr(skb)->tos; |
| inet_csk(newsk)->icsk_ext_hdr_len = 0; |
| if (inet_opt) |
| inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen; |
| atomic_set(&newinet->inet_id, get_random_u16()); |
| |
| /* 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)) |
| newinet->tos = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK; |
| |
| if (!dst) { |
| dst = inet_csk_route_child_sock(sk, newsk, req); |
| if (!dst) |
| goto put_and_exit; |
| } else { |
| /* syncookie case : see end of cookie_v4_check() */ |
| } |
| sk_setup_caps(newsk, dst); |
| |
| 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); |
| |
| #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 */ |
| addr = (union tcp_md5_addr *)&newinet->inet_daddr; |
| key = tcp_md5_do_lookup(sk, l3index, addr, AF_INET); |
| if (key && !tcp_rsk_used_ao(req)) { |
| if (tcp_md5_key_copy(newsk, addr, AF_INET, 32, l3index, key)) |
| goto put_and_exit; |
| sk_gso_disable(newsk); |
| } |
| #endif |
| #ifdef CONFIG_TCP_AO |
| if (tcp_ao_copy_all_matching(sk, newsk, req, skb, AF_INET)) |
| goto put_and_exit; /* OOM, release back memory */ |
| #endif |
| |
| if (__inet_inherit_port(sk, newsk) < 0) |
| goto put_and_exit; |
| *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash), |
| &found_dup_sk); |
| if (likely(*own_req)) { |
| tcp_move_syn(newtp, req); |
| ireq->ireq_opt = NULL; |
| } else { |
| newinet->inet_opt = NULL; |
| |
| 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; |
| |
| exit_overflow: |
| NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
| exit_nonewsk: |
| dst_release(dst); |
| exit: |
| tcp_listendrop(sk); |
| return NULL; |
| put_and_exit: |
| newinet->inet_opt = NULL; |
| inet_csk_prepare_forced_close(newsk); |
| tcp_done(newsk); |
| goto exit; |
| } |
| EXPORT_SYMBOL(tcp_v4_syn_recv_sock); |
| |
| static struct sock *tcp_v4_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_v4_check(sk, skb); |
| #endif |
| return sk; |
| } |
| |
| u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, |
| struct tcphdr *th, u32 *cookie) |
| { |
| u16 mss = 0; |
| #ifdef CONFIG_SYN_COOKIES |
| mss = tcp_get_syncookie_mss(&tcp_request_sock_ops, |
| &tcp_request_sock_ipv4_ops, sk, th); |
| if (mss) { |
| *cookie = __cookie_v4_init_sequence(iph, th, &mss); |
| tcp_synq_overflow(sk); |
| } |
| #endif |
| return mss; |
| } |
| |
| 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. |
| */ |
| int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb) |
| { |
| enum skb_drop_reason reason; |
| struct sock *rsk; |
| |
| 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, ipv4_dst_check, |
| dst, 0)) { |
| RCU_INIT_POINTER(sk->sk_rx_dst, NULL); |
| dst_release(dst); |
| } |
| } |
| tcp_rcv_established(sk, skb); |
| return 0; |
| } |
| |
| if (tcp_checksum_complete(skb)) |
| goto csum_err; |
| |
| if (sk->sk_state == TCP_LISTEN) { |
| struct sock *nsk = tcp_v4_cookie_check(sk, skb); |
| |
| if (!nsk) |
| return 0; |
| if (nsk != sk) { |
| reason = tcp_child_process(sk, nsk, skb); |
| if (reason) { |
| rsk = nsk; |
| goto reset; |
| } |
| return 0; |
| } |
| } else |
| sock_rps_save_rxhash(sk, skb); |
| |
| reason = tcp_rcv_state_process(sk, skb); |
| if (reason) { |
| rsk = sk; |
| goto reset; |
| } |
| return 0; |
| |
| reset: |
| tcp_v4_send_reset(rsk, skb, sk_rst_convert_drop_reason(reason)); |
| discard: |
| sk_skb_reason_drop(sk, skb, reason); |
| /* Be careful here. If this function gets more complicated and |
| * gcc suffers from register pressure on the x86, sk (in %ebx) |
| * might be destroyed here. This current version compiles correctly, |
| * but you have been warned. |
| */ |
| 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; |
| } |
| EXPORT_SYMBOL(tcp_v4_do_rcv); |
| |
| int tcp_v4_early_demux(struct sk_buff *skb) |
| { |
| struct net *net = dev_net(skb->dev); |
| const struct iphdr *iph; |
| const struct tcphdr *th; |
| struct sock *sk; |
| |
| if (skb->pkt_type != PACKET_HOST) |
| return 0; |
| |
| if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) |
| return 0; |
| |
| iph = ip_hdr(skb); |
| th = tcp_hdr(skb); |
| |
| if (th->doff < sizeof(struct tcphdr) / 4) |
| return 0; |
| |
| sk = __inet_lookup_established(net, net->ipv4.tcp_death_row.hashinfo, |
| iph->saddr, th->source, |
| iph->daddr, ntohs(th->dest), |
| skb->skb_iif, inet_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, 0); |
| if (dst && |
| sk->sk_rx_dst_ifindex == skb->skb_iif) |
| skb_dst_set_noref(skb, dst); |
| } |
| } |
| return 0; |
| } |
| |
| bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb, |
| enum skb_drop_reason *reason) |
| { |
| u32 tail_gso_size, tail_gso_segs; |
| struct skb_shared_info *shinfo; |
| const struct tcphdr *th; |
| struct tcphdr *thtail; |
| struct sk_buff *tail; |
| unsigned int hdrlen; |
| bool fragstolen; |
| u32 gso_segs; |
| u32 gso_size; |
| u64 limit; |
| int delta; |
| |
| /* In case all data was pulled from skb frags (in __pskb_pull_tail()), |
| * we can fix skb->truesize to its real value to avoid future drops. |
| * This is valid because skb is not yet charged to the socket. |
| * It has been noticed pure SACK packets were sometimes dropped |
| * (if cooked by drivers without copybreak feature). |
| */ |
| skb_condense(skb); |
| |
| skb_dst_drop(skb); |
| |
| if (unlikely(tcp_checksum_complete(skb))) { |
| bh_unlock_sock(sk); |
| trace_tcp_bad_csum(skb); |
| *reason = SKB_DROP_REASON_TCP_CSUM; |
| __TCP_INC_STATS(sock_net(sk), TCP_MIB_CSUMERRORS); |
| __TCP_INC_STATS(sock_net(sk), TCP_MIB_INERRS); |
| return true; |
| } |
| |
| /* Attempt coalescing to last skb in backlog, even if we are |
| * above the limits. |
| * This is okay because skb capacity is limited to MAX_SKB_FRAGS. |
| */ |
| th = (const struct tcphdr *)skb->data; |
| hdrlen = th->doff * 4; |
| |
| tail = sk->sk_backlog.tail; |
| if (!tail) |
| goto no_coalesce; |
| thtail = (struct tcphdr *)tail->data; |
| |
| if (TCP_SKB_CB(tail)->end_seq != TCP_SKB_CB(skb)->seq || |
| TCP_SKB_CB(tail)->ip_dsfield != TCP_SKB_CB(skb)->ip_dsfield || |
| ((TCP_SKB_CB(tail)->tcp_flags | |
| TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_SYN | TCPHDR_RST | TCPHDR_URG)) || |
| !((TCP_SKB_CB(tail)->tcp_flags & |
| TCP_SKB_CB(skb)->tcp_flags) & TCPHDR_ACK) || |
| ((TCP_SKB_CB(tail)->tcp_flags ^ |
| TCP_SKB_CB(skb)->tcp_flags) & (TCPHDR_ECE | TCPHDR_CWR)) || |
| !tcp_skb_can_collapse_rx(tail, skb) || |
| thtail->doff != th->doff || |
| memcmp(thtail + 1, th + 1, hdrlen - sizeof(*th))) |
| goto no_coalesce; |
| |
| __skb_pull(skb, hdrlen); |
| |
| shinfo = skb_shinfo(skb); |
| gso_size = shinfo->gso_size ?: skb->len; |
| gso_segs = shinfo->gso_segs ?: 1; |
| |
| shinfo = skb_shinfo(tail); |
| tail_gso_size = shinfo->gso_size ?: (tail->len - hdrlen); |
| tail_gso_segs = shinfo->gso_segs ?: 1; |
| |
| if (skb_try_coalesce(tail, skb, &fragstolen, &delta)) { |
| TCP_SKB_CB(tail)->end_seq = TCP_SKB_CB(skb)->end_seq; |
| |
| if (likely(!before(TCP_SKB_CB(skb)->ack_seq, TCP_SKB_CB(tail)->ack_seq))) { |
| TCP_SKB_CB(tail)->ack_seq = TCP_SKB_CB(skb)->ack_seq; |
| thtail->window = th->window; |
| } |
| |
| /* We have to update both TCP_SKB_CB(tail)->tcp_flags and |
| * thtail->fin, so that the fast path in tcp_rcv_established() |
| * is not entered if we append a packet with a FIN. |
| * SYN, RST, URG are not present. |
| * ACK is set on both packets. |
| * PSH : we do not really care in TCP stack, |
| * at least for 'GRO' packets. |
| */ |
| thtail->fin |= th->fin; |
| TCP_SKB_CB(tail)->tcp_flags |= TCP_SKB_CB(skb)->tcp_flags; |
| |
| if (TCP_SKB_CB(skb)->has_rxtstamp) { |
| TCP_SKB_CB(tail)->has_rxtstamp = true; |
| tail->tstamp = skb->tstamp; |
| skb_hwtstamps(tail)->hwtstamp = skb_hwtstamps(skb)->hwtstamp; |
| } |
| |
| /* Not as strict as GRO. We only need to carry mss max value */ |
| shinfo->gso_size = max(gso_size, tail_gso_size); |
| shinfo->gso_segs = min_t(u32, gso_segs + tail_gso_segs, 0xFFFF); |
| |
| sk->sk_backlog.len += delta; |
| __NET_INC_STATS(sock_net(sk), |
| LINUX_MIB_TCPBACKLOGCOALESCE); |
| kfree_skb_partial(skb, fragstolen); |
| return false; |
| } |
| __skb_push(skb, hdrlen); |
| |
| no_coalesce: |
| /* sk->sk_backlog.len is reset only at the end of __release_sock(). |
| * Both sk->sk_backlog.len and sk->sk_rmem_alloc could reach |
| * sk_rcvbuf in normal conditions. |
| */ |
| limit = ((u64)READ_ONCE(sk->sk_rcvbuf)) << 1; |
| |
| limit += ((u32)READ_ONCE(sk->sk_sndbuf)) >> 1; |
| |
| /* Only socket owner can try to collapse/prune rx queues |
| * to reduce memory overhead, so add a little headroom here. |
| * Few sockets backlog are possibly concurrently non empty. |
| */ |
| limit += 64 * 1024; |
| |
| limit = min_t(u64, limit, UINT_MAX); |
| |
| if (unlikely(sk_add_backlog(sk, skb, limit))) { |
| bh_unlock_sock(sk); |
| *reason = SKB_DROP_REASON_SOCKET_BACKLOG; |
| __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPBACKLOGDROP); |
| return true; |
| } |
| return false; |
| } |
| EXPORT_SYMBOL(tcp_add_backlog); |
| |
| int tcp_filter(struct sock *sk, struct sk_buff *skb) |
| { |
| struct tcphdr *th = (struct tcphdr *)skb->data; |
| |
| return sk_filter_trim_cap(sk, skb, th->doff * 4); |
| } |
| EXPORT_SYMBOL(tcp_filter); |
| |
| static void tcp_v4_restore_cb(struct sk_buff *skb) |
| { |
| memmove(IPCB(skb), &TCP_SKB_CB(skb)->header.h4, |
| sizeof(struct inet_skb_parm)); |
| } |
| |
| static void tcp_v4_fill_cb(struct sk_buff *skb, const struct iphdr *iph, |
| const struct tcphdr *th) |
| { |
| /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB() |
| * barrier() makes sure compiler wont play fool^Waliasing games. |
| */ |
| memmove(&TCP_SKB_CB(skb)->header.h4, IPCB(skb), |
| sizeof(struct inet_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)->ip_dsfield = ipv4_get_dsfield(iph); |
| TCP_SKB_CB(skb)->sacked = 0; |
| TCP_SKB_CB(skb)->has_rxtstamp = |
| skb->tstamp || skb_hwtstamps(skb)->hwtstamp; |
| } |
| |
| /* |
| * From tcp_input.c |
| */ |
| |
| int tcp_v4_rcv(struct sk_buff *skb) |
| { |
| struct net *net = dev_net(skb->dev); |
| enum skb_drop_reason drop_reason; |
| int sdif = inet_sdif(skb); |
| int dif = inet_iif(skb); |
| const struct iphdr *iph; |
| const struct tcphdr *th; |
| struct sock *sk = NULL; |
| bool refcounted; |
| int ret; |
| u32 isn; |
| |
| 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; |
| |
| /* An explanation is required here, I think. |
| * Packet length and doff are validated by header prediction, |
| * provided case of th->doff==0 is eliminated. |
| * So, we defer the checks. */ |
| |
| if (skb_checksum_init(skb, IPPROTO_TCP, inet_compute_pseudo)) |
| goto csum_error; |
| |
| th = (const struct tcphdr *)skb->data; |
| iph = ip_hdr(skb); |
| lookup: |
| sk = __inet_lookup_skb(net->ipv4.tcp_death_row.hashinfo, |
| skb, __tcp_hdrlen(th), th->source, |
| th->dest, sdif, &refcounted); |
| if (!sk) |
| goto no_tcp_socket; |
| |
| 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 (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
| drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
| else |
| drop_reason = tcp_inbound_hash(sk, req, skb, |
| &iph->saddr, &iph->daddr, |
| AF_INET, dif, sdif); |
| if (unlikely(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 { |
| /* We own a reference on the listener, increase it again |
| * as we might lose it too soon. |
| */ |
| sock_hold(sk); |
| } |
| refcounted = true; |
| nsk = NULL; |
| if (!tcp_filter(sk, skb)) { |
| th = (const struct tcphdr *)skb->data; |
| iph = ip_hdr(skb); |
| tcp_v4_fill_cb(skb, iph, 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_v4_restore_cb(skb); |
| sock_put(sk); |
| goto lookup; |
| } |
| goto discard_and_relse; |
| } |
| nf_reset_ct(skb); |
| if (nsk == sk) { |
| reqsk_put(req); |
| tcp_v4_restore_cb(skb); |
| } else { |
| drop_reason = tcp_child_process(sk, nsk, skb); |
| if (drop_reason) { |
| enum sk_rst_reason rst_reason; |
| |
| rst_reason = sk_rst_convert_drop_reason(drop_reason); |
| tcp_v4_send_reset(nsk, skb, rst_reason); |
| goto discard_and_relse; |
| } |
| sock_put(sk); |
| return 0; |
| } |
| } |
| |
| process: |
| if (static_branch_unlikely(&ip4_min_ttl)) { |
| /* min_ttl can be changed concurrently from do_ip_setsockopt() */ |
| if (unlikely(iph->ttl < READ_ONCE(inet_sk(sk)->min_ttl))) { |
| __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); |
| drop_reason = SKB_DROP_REASON_TCP_MINTTL; |
| goto discard_and_relse; |
| } |
| } |
| |
| if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) { |
| drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
| goto discard_and_relse; |
| } |
| |
| drop_reason = tcp_inbound_hash(sk, NULL, skb, &iph->saddr, &iph->daddr, |
| AF_INET, 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; |
| iph = ip_hdr(skb); |
| tcp_v4_fill_cb(skb, iph, th); |
| |
| skb->dev = NULL; |
| |
| if (sk->sk_state == TCP_LISTEN) { |
| ret = tcp_v4_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_v4_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; |
| |
| no_tcp_socket: |
| drop_reason = SKB_DROP_REASON_NO_SOCKET; |
| if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) |
| goto discard_it; |
| |
| tcp_v4_fill_cb(skb, iph, 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_v4_send_reset(NULL, skb, sk_rst_convert_drop_reason(drop_reason)); |
| } |
| |
| discard_it: |
| SKB_DR_OR(drop_reason, NOT_SPECIFIED); |
| /* Discard frame. */ |
| sk_skb_reason_drop(sk, 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 (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| drop_reason = SKB_DROP_REASON_XFRM_POLICY; |
| inet_twsk_put(inet_twsk(sk)); |
| goto discard_it; |
| } |
| |
| tcp_v4_fill_cb(skb, iph, 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, &isn)) { |
| case TCP_TW_SYN: { |
| struct sock *sk2 = inet_lookup_listener(net, |
| net->ipv4.tcp_death_row.hashinfo, |
| skb, __tcp_hdrlen(th), |
| iph->saddr, th->source, |
| iph->daddr, th->dest, |
| inet_iif(skb), |
| sdif); |
| if (sk2) { |
| inet_twsk_deschedule_put(inet_twsk(sk)); |
| sk = sk2; |
| tcp_v4_restore_cb(skb); |
| refcounted = false; |
| __this_cpu_write(tcp_tw_isn, isn); |
| goto process; |
| } |
| } |
| /* to ACK */ |
| fallthrough; |
| case TCP_TW_ACK: |
| tcp_v4_timewait_ack(sk, skb); |
| break; |
| case TCP_TW_RST: |
| tcp_v4_send_reset(sk, skb, SK_RST_REASON_TCP_TIMEWAIT_SOCKET); |
| inet_twsk_deschedule_put(inet_twsk(sk)); |
| goto discard_it; |
| case TCP_TW_SUCCESS:; |
| } |
| goto discard_it; |
| } |
| |
| static struct timewait_sock_ops tcp_timewait_sock_ops = { |
| .twsk_obj_size = sizeof(struct tcp_timewait_sock), |
| .twsk_destructor= tcp_twsk_destructor, |
| }; |
| |
| void inet_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)) { |
| rcu_assign_pointer(sk->sk_rx_dst, dst); |
| sk->sk_rx_dst_ifindex = skb->skb_iif; |
| } |
| } |
| EXPORT_SYMBOL(inet_sk_rx_dst_set); |
| |
| const struct inet_connection_sock_af_ops ipv4_specific = { |
| .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_v4_conn_request, |
| .syn_recv_sock = tcp_v4_syn_recv_sock, |
| .net_header_len = sizeof(struct iphdr), |
| .setsockopt = ip_setsockopt, |
| .getsockopt = ip_getsockopt, |
| .addr2sockaddr = inet_csk_addr2sockaddr, |
| .sockaddr_len = sizeof(struct sockaddr_in), |
| .mtu_reduced = tcp_v4_mtu_reduced, |
| }; |
| EXPORT_SYMBOL(ipv4_specific); |
| |
| #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) |
| static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { |
| #ifdef CONFIG_TCP_MD5SIG |
| .md5_lookup = tcp_v4_md5_lookup, |
| .calc_md5_hash = tcp_v4_md5_hash_skb, |
| .md5_parse = tcp_v4_parse_md5_keys, |
| #endif |
| #ifdef CONFIG_TCP_AO |
| .ao_lookup = tcp_v4_ao_lookup, |
| .calc_ao_hash = tcp_v4_ao_hash_skb, |
| .ao_parse = tcp_v4_parse_ao, |
| .ao_calc_key_sk = tcp_v4_ao_calc_key_sk, |
| #endif |
| }; |
| #endif |
| |
| /* NOTE: A lot of things set to zero explicitly by call to |
| * sk_alloc() so need not be done here. |
| */ |
| static int tcp_v4_init_sock(struct sock *sk) |
| { |
| struct inet_connection_sock *icsk = inet_csk(sk); |
| |
| tcp_init_sock(sk); |
| |
| icsk->icsk_af_ops = &ipv4_specific; |
| |
| #if defined(CONFIG_TCP_MD5SIG) || defined(CONFIG_TCP_AO) |
| tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific; |
| #endif |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| static void tcp_md5sig_info_free_rcu(struct rcu_head *head) |
| { |
| struct tcp_md5sig_info *md5sig; |
| |
| md5sig = container_of(head, struct tcp_md5sig_info, rcu); |
| kfree(md5sig); |
| static_branch_slow_dec_deferred(&tcp_md5_needed); |
| tcp_md5_release_sigpool(); |
| } |
| #endif |
| |
| void tcp_v4_destroy_sock(struct sock *sk) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| trace_tcp_destroy_sock(sk); |
| |
| tcp_clear_xmit_timers(sk); |
| |
| tcp_cleanup_congestion_control(sk); |
| |
| tcp_cleanup_ulp(sk); |
| |
| /* Cleanup up the write buffer. */ |
| tcp_write_queue_purge(sk); |
| |
| /* Check if we want to disable active TFO */ |
| tcp_fastopen_active_disable_ofo_check(sk); |
| |
| /* Cleans up our, hopefully empty, out_of_order_queue. */ |
| skb_rbtree_purge(&tp->out_of_order_queue); |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| /* Clean up the MD5 key list, if any */ |
| if (tp->md5sig_info) { |
| struct tcp_md5sig_info *md5sig; |
| |
| md5sig = rcu_dereference_protected(tp->md5sig_info, 1); |
| tcp_clear_md5_list(sk); |
| call_rcu(&md5sig->rcu, tcp_md5sig_info_free_rcu); |
| rcu_assign_pointer(tp->md5sig_info, NULL); |
| } |
| #endif |
| tcp_ao_destroy_sock(sk, false); |
| |
| /* Clean up a referenced TCP bind bucket. */ |
| if (inet_csk(sk)->icsk_bind_hash) |
| inet_put_port(sk); |
| |
| BUG_ON(rcu_access_pointer(tp->fastopen_rsk)); |
| |
| /* If socket is aborted during connect operation */ |
| tcp_free_fastopen_req(tp); |
| tcp_fastopen_destroy_cipher(sk); |
| tcp_saved_syn_free(tp); |
| |
| sk_sockets_allocated_dec(sk); |
| } |
| EXPORT_SYMBOL(tcp_v4_destroy_sock); |
| |
| #ifdef CONFIG_PROC_FS |
| /* Proc filesystem TCP sock list dumping. */ |
| |
| static unsigned short seq_file_family(const struct seq_file *seq); |
| |
| static bool seq_sk_match(struct seq_file *seq, const struct sock *sk) |
| { |
| unsigned short family = seq_file_family(seq); |
| |
| /* AF_UNSPEC is used as a match all */ |
| return ((family == AF_UNSPEC || family == sk->sk_family) && |
| net_eq(sock_net(sk), seq_file_net(seq))); |
| } |
| |
| /* Find a non empty bucket (starting from st->bucket) |
| * and return the first sk from it. |
| */ |
| static void *listening_get_first(struct seq_file *seq) |
| { |
| struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
| struct tcp_iter_state *st = seq->private; |
| |
| st->offset = 0; |
| for (; st->bucket <= hinfo->lhash2_mask; st->bucket++) { |
| struct inet_listen_hashbucket *ilb2; |
| struct hlist_nulls_node *node; |
| struct sock *sk; |
| |
| ilb2 = &hinfo->lhash2[st->bucket]; |
| if (hlist_nulls_empty(&ilb2->nulls_head)) |
| continue; |
| |
| spin_lock(&ilb2->lock); |
| sk_nulls_for_each(sk, node, &ilb2->nulls_head) { |
| if (seq_sk_match(seq, sk)) |
| return sk; |
| } |
| spin_unlock(&ilb2->lock); |
| } |
| |
| return NULL; |
| } |
| |
| /* Find the next sk of "cur" within the same bucket (i.e. st->bucket). |
| * If "cur" is the last one in the st->bucket, |
| * call listening_get_first() to return the first sk of the next |
| * non empty bucket. |
| */ |
| static void *listening_get_next(struct seq_file *seq, void *cur) |
| { |
| struct tcp_iter_state *st = seq->private; |
| struct inet_listen_hashbucket *ilb2; |
| struct hlist_nulls_node *node; |
| struct inet_hashinfo *hinfo; |
| struct sock *sk = cur; |
| |
| ++st->num; |
| ++st->offset; |
| |
| sk = sk_nulls_next(sk); |
| sk_nulls_for_each_from(sk, node) { |
| if (seq_sk_match(seq, sk)) |
| return sk; |
| } |
| |
| hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
| ilb2 = &hinfo->lhash2[st->bucket]; |
| spin_unlock(&ilb2->lock); |
| ++st->bucket; |
| return listening_get_first(seq); |
| } |
| |
| static void *listening_get_idx(struct seq_file *seq, loff_t *pos) |
| { |
| struct tcp_iter_state *st = seq->private; |
| void *rc; |
| |
| st->bucket = 0; |
| st->offset = 0; |
| rc = listening_get_first(seq); |
| |
| while (rc && *pos) { |
| rc = listening_get_next(seq, rc); |
| --*pos; |
| } |
| return rc; |
| } |
| |
| static inline bool empty_bucket(struct inet_hashinfo *hinfo, |
| const struct tcp_iter_state *st) |
| { |
| return hlist_nulls_empty(&hinfo->ehash[st->bucket].chain); |
| } |
| |
| /* |
| * Get first established socket starting from bucket given in st->bucket. |
| * If st->bucket is zero, the very first socket in the hash is returned. |
| */ |
| static void *established_get_first(struct seq_file *seq) |
| { |
| struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
| struct tcp_iter_state *st = seq->private; |
| |
| st->offset = 0; |
| for (; st->bucket <= hinfo->ehash_mask; ++st->bucket) { |
| struct sock *sk; |
| struct hlist_nulls_node *node; |
| spinlock_t *lock = inet_ehash_lockp(hinfo, st->bucket); |
| |
| cond_resched(); |
| |
| /* Lockless fast path for the common case of empty buckets */ |
| if (empty_bucket(hinfo, st)) |
| continue; |
| |
| spin_lock_bh(lock); |
| sk_nulls_for_each(sk, node, &hinfo->ehash[st->bucket].chain) { |
| if (seq_sk_match(seq, sk)) |
| return sk; |
| } |
| spin_unlock_bh(lock); |
| } |
| |
| return NULL; |
| } |
| |
| static void *established_get_next(struct seq_file *seq, void *cur) |
| { |
| struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
| struct tcp_iter_state *st = seq->private; |
| struct hlist_nulls_node *node; |
| struct sock *sk = cur; |
| |
| ++st->num; |
| ++st->offset; |
| |
| sk = sk_nulls_next(sk); |
| |
| sk_nulls_for_each_from(sk, node) { |
| if (seq_sk_match(seq, sk)) |
| return sk; |
| } |
| |
| spin_unlock_bh(inet_ehash_lockp(hinfo, st->bucket)); |
| ++st->bucket; |
| return established_get_first(seq); |
| } |
| |
| static void *established_get_idx(struct seq_file *seq, loff_t pos) |
| { |
| struct tcp_iter_state *st = seq->private; |
| void *rc; |
| |
| st->bucket = 0; |
| rc = established_get_first(seq); |
| |
| while (rc && pos) { |
| rc = established_get_next(seq, rc); |
| --pos; |
| } |
| return rc; |
| } |
| |
| static void *tcp_get_idx(struct seq_file *seq, loff_t pos) |
| { |
| void *rc; |
| struct tcp_iter_state *st = seq->private; |
| |
| st->state = TCP_SEQ_STATE_LISTENING; |
| rc = listening_get_idx(seq, &pos); |
| |
| if (!rc) { |
| st->state = TCP_SEQ_STATE_ESTABLISHED; |
| rc = established_get_idx(seq, pos); |
| } |
| |
| return rc; |
| } |
| |
| static void *tcp_seek_last_pos(struct seq_file *seq) |
| { |
| struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
| struct tcp_iter_state *st = seq->private; |
| int bucket = st->bucket; |
| int offset = st->offset; |
| int orig_num = st->num; |
| void *rc = NULL; |
| |
| switch (st->state) { |
| case TCP_SEQ_STATE_LISTENING: |
| if (st->bucket > hinfo->lhash2_mask) |
| break; |
| rc = listening_get_first(seq); |
| while (offset-- && rc && bucket == st->bucket) |
| rc = listening_get_next(seq, rc); |
| if (rc) |
| break; |
| st->bucket = 0; |
| st->state = TCP_SEQ_STATE_ESTABLISHED; |
| fallthrough; |
| case TCP_SEQ_STATE_ESTABLISHED: |
| if (st->bucket > hinfo->ehash_mask) |
| break; |
| rc = established_get_first(seq); |
| while (offset-- && rc && bucket == st->bucket) |
| rc = established_get_next(seq, rc); |
| } |
| |
| st->num = orig_num; |
| |
| return rc; |
| } |
| |
| void *tcp_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct tcp_iter_state *st = seq->private; |
| void *rc; |
| |
| if (*pos && *pos == st->last_pos) { |
| rc = tcp_seek_last_pos(seq); |
| if (rc) |
| goto out; |
| } |
| |
| st->state = TCP_SEQ_STATE_LISTENING; |
| st->num = 0; |
| st->bucket = 0; |
| st->offset = 0; |
| rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; |
| |
| out: |
| st->last_pos = *pos; |
| return rc; |
| } |
| EXPORT_SYMBOL(tcp_seq_start); |
| |
| void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
| { |
| struct tcp_iter_state *st = seq->private; |
| void *rc = NULL; |
| |
| if (v == SEQ_START_TOKEN) { |
| rc = tcp_get_idx(seq, 0); |
| goto out; |
| } |
| |
| switch (st->state) { |
| case TCP_SEQ_STATE_LISTENING: |
| rc = listening_get_next(seq, v); |
| if (!rc) { |
| st->state = TCP_SEQ_STATE_ESTABLISHED; |
| st->bucket = 0; |
| st->offset = 0; |
| rc = established_get_first(seq); |
| } |
| break; |
| case TCP_SEQ_STATE_ESTABLISHED: |
| rc = established_get_next(seq, v); |
| break; |
| } |
| out: |
| ++*pos; |
| st->last_pos = *pos; |
| return rc; |
| } |
| EXPORT_SYMBOL(tcp_seq_next); |
| |
| void tcp_seq_stop(struct seq_file *seq, void *v) |
| { |
| struct inet_hashinfo *hinfo = seq_file_net(seq)->ipv4.tcp_death_row.hashinfo; |
| struct tcp_iter_state *st = seq->private; |
| |
| switch (st->state) { |
| case TCP_SEQ_STATE_LISTENING: |
| if (v != SEQ_START_TOKEN) |
| spin_unlock(&hinfo->lhash2[st->bucket].lock); |
| break; |
| case TCP_SEQ_STATE_ESTABLISHED: |
| if (v) |
| spin_unlock_bh(inet_ehash_lockp(hinfo, st->bucket)); |
| break; |
| } |
| } |
| EXPORT_SYMBOL(tcp_seq_stop); |
| |
| static void get_openreq4(const struct request_sock *req, |
| struct seq_file *f, int i) |
| { |
| const struct inet_request_sock *ireq = inet_rsk(req); |
| long delta = req->rsk_timer.expires - jiffies; |
| |
| seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
| " %02X %08X:%08X %02X:%08lX %08X %5u %8d %u %d %pK", |
| i, |
| ireq->ir_loc_addr, |
| ireq->ir_num, |
| ireq->ir_rmt_addr, |
| ntohs(ireq->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_delta_to_clock_t(delta), |
| req->num_timeout, |
| from_kuid_munged(seq_user_ns(f), |
| sock_i_uid(req->rsk_listener)), |
| 0, /* non standard timer */ |
| 0, /* open_requests have no inode */ |
| 0, |
| req); |
| } |
| |
| static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i) |
| { |
| int timer_active; |
| unsigned long timer_expires; |
| const struct tcp_sock *tp = tcp_sk(sk); |
| const struct inet_connection_sock *icsk = inet_csk(sk); |
| const struct inet_sock *inet = inet_sk(sk); |
| const struct fastopen_queue *fastopenq = &icsk->icsk_accept_queue.fastopenq; |
| __be32 dest = inet->inet_daddr; |
| __be32 src = inet->inet_rcv_saddr; |
| __u16 destp = ntohs(inet->inet_dport); |
| __u16 srcp = ntohs(inet->inet_sport); |
| int rx_queue; |
| int state; |
| |
| 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(&sk->sk_timer)) { |
| timer_active = 2; |
| timer_expires = sk->sk_timer.expires; |
| } else { |
| timer_active = 0; |
| timer_expires = jiffies; |
| } |
| |
| state = inet_sk_state_load(sk); |
| if (state == TCP_LISTEN) |
| rx_queue = READ_ONCE(sk->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(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX " |
| "%08X %5u %8d %lu %d %pK %lu %lu %u %u %d", |
| i, src, srcp, dest, 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(f), sock_i_uid(sk)), |
| icsk->icsk_probes_out, |
| sock_i_ino(sk), |
| refcount_read(&sk->sk_refcnt), sk, |
| 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(sk), |
| tcp_snd_cwnd(tp), |
| state == TCP_LISTEN ? |
| fastopenq->max_qlen : |
| (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)); |
| } |
| |
| static void get_timewait4_sock(const struct inet_timewait_sock *tw, |
| struct seq_file *f, int i) |
| { |
| long delta = tw->tw_timer.expires - jiffies; |
| __be32 dest, src; |
| __u16 destp, srcp; |
| |
| dest = tw->tw_daddr; |
| src = tw->tw_rcv_saddr; |
| destp = ntohs(tw->tw_dport); |
| srcp = ntohs(tw->tw_sport); |
| |
| seq_printf(f, "%4d: %08X:%04X %08X:%04X" |
| " %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK", |
| i, src, srcp, dest, destp, tw->tw_substate, 0, 0, |
| 3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0, |
| refcount_read(&tw->tw_refcnt), tw); |
| } |
| |
| #define TMPSZ 150 |
| |
| static int tcp4_seq_show(struct seq_file *seq, void *v) |
| { |
| struct tcp_iter_state *st; |
| struct sock *sk = v; |
| |
| seq_setwidth(seq, TMPSZ - 1); |
| if (v == SEQ_START_TOKEN) { |
| seq_puts(seq, " sl local_address rem_address st tx_queue " |
| "rx_queue tr tm->when retrnsmt uid timeout " |
| "inode"); |
| goto out; |
| } |
| st = seq->private; |
| |
| if (sk->sk_state == TCP_TIME_WAIT) |
| get_timewait4_sock(v, seq, st->num); |
| else if (sk->sk_state == TCP_NEW_SYN_RECV) |
| get_openreq4(v, seq, st->num); |
| else |
| get_tcp4_sock(v, seq, st->num); |
| out: |
| seq_pad(seq, '\n'); |
| return 0; |
| } |
| |
| #ifdef CONFIG_BPF_SYSCALL |
| struct bpf_tcp_iter_state { |
| struct tcp_iter_state state; |
| unsigned int cur_sk; |
| unsigned int end_sk; |
| unsigned int max_sk; |
| struct sock **batch; |
| bool st_bucket_done; |
| }; |
| |
| struct bpf_iter__tcp { |
| __bpf_md_ptr(struct bpf_iter_meta *, meta); |
| __bpf_md_ptr(struct sock_common *, sk_common); |
| uid_t uid __aligned(8); |
| }; |
| |
| static int tcp_prog_seq_show(struct bpf_prog *prog, struct bpf_iter_meta *meta, |
| struct sock_common *sk_common, uid_t uid) |
| { |
| struct bpf_iter__tcp ctx; |
| |
| meta->seq_num--; /* skip SEQ_START_TOKEN */ |
| ctx.meta = meta; |
| |