| /* |
| * 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 |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| /* |
| * 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 <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/tcp_memcontrol.h> |
| #include <net/busy_poll.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/crypto.h> |
| #include <linux/scatterlist.h> |
| |
| int sysctl_tcp_tw_reuse __read_mostly; |
| int sysctl_tcp_low_latency __read_mostly; |
| EXPORT_SYMBOL(sysctl_tcp_low_latency); |
| |
| #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 __u32 tcp_v4_init_sequence(const struct sk_buff *skb) |
| { |
| return secure_tcp_sequence_number(ip_hdr(skb)->daddr, |
| ip_hdr(skb)->saddr, |
| tcp_hdr(skb)->dest, |
| tcp_hdr(skb)->source); |
| } |
| |
| int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) |
| { |
| const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| /* 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. |
| */ |
| if (tcptw->tw_ts_recent_stamp && |
| (!twp || (sysctl_tcp_tw_reuse && |
| get_seconds() - tcptw->tw_ts_recent_stamp > 1))) { |
| tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2; |
| if (tp->write_seq == 0) |
| tp->write_seq = 1; |
| tp->rx_opt.ts_recent = tcptw->tw_ts_recent; |
| tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp; |
| sock_hold(sktw); |
| return 1; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(tcp_twsk_unique); |
| |
| /* 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_sock *inet = inet_sk(sk); |
| struct tcp_sock *tp = tcp_sk(sk); |
| __be16 orig_sport, orig_dport; |
| __be32 daddr, nexthop; |
| struct flowi4 *fl4; |
| struct rtable *rt; |
| int err; |
| struct ip_options_rcu *inet_opt; |
| |
| 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, |
| sock_owned_by_user(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, |
| RT_CONN_FLAGS(sk), 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(sock_net(sk), 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; |
| |
| if (!inet->inet_saddr) |
| inet->inet_saddr = fl4->saddr; |
| 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)) |
| tp->write_seq = 0; |
| } |
| |
| if (tcp_death_row.sysctl_tw_recycle && |
| !tp->rx_opt.ts_recent_stamp && fl4->daddr == daddr) |
| tcp_fetch_timewait_stamp(sk, &rt->dst); |
| |
| 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; |
| } |
| /* OK, now commit destination to socket. */ |
| sk->sk_gso_type = SKB_GSO_TCPV4; |
| sk_setup_caps(sk, &rt->dst); |
| |
| if (!tp->write_seq && likely(!tp->repair)) |
| tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr, |
| inet->inet_daddr, |
| inet->inet_sport, |
| usin->sin_port); |
| |
| inet->inet_id = tp->write_seq ^ jiffies; |
| |
| err = tcp_connect(sk); |
| |
| rt = NULL; |
| if (err) |
| goto failure; |
| |
| return 0; |
| |
| failure: |
| /* |
| * This unhashes the socket and releases the local port, |
| * if necessary. |
| */ |
| tcp_set_state(sk, TCP_CLOSE); |
| 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 dst_entry *dst; |
| struct inet_sock *inet = inet_sk(sk); |
| u32 mtu = 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)) |
| 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) |
| { |
| 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. |
| */ |
| WARN_ON(req->sk); |
| |
| if (seq != tcp_rsk(req)->snt_isn) { |
| NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); |
| } else { |
| /* |
| * 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); |
| NET_INC_STATS_BH(net, LINUX_MIB_LISTENDROPS); |
| } |
| reqsk_put(req); |
| } |
| EXPORT_SYMBOL(tcp_req_err); |
| |
| /* |
| * 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. |
| * |
| */ |
| |
| void tcp_v4_err(struct sk_buff *icmp_skb, u32 info) |
| { |
| const struct iphdr *iph = (const struct iphdr *)icmp_skb->data; |
| struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2)); |
| struct inet_connection_sock *icsk; |
| struct tcp_sock *tp; |
| struct inet_sock *inet; |
| const int type = icmp_hdr(icmp_skb)->type; |
| const int code = icmp_hdr(icmp_skb)->code; |
| struct sock *sk; |
| struct sk_buff *skb; |
| struct request_sock *fastopen; |
| __u32 seq, snd_una; |
| __u32 remaining; |
| int err; |
| struct net *net = dev_net(icmp_skb->dev); |
| |
| sk = __inet_lookup_established(net, &tcp_hashinfo, iph->daddr, |
| th->dest, iph->saddr, ntohs(th->source), |
| inet_iif(icmp_skb)); |
| if (!sk) { |
| ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); |
| return; |
| } |
| if (sk->sk_state == TCP_TIME_WAIT) { |
| inet_twsk_put(inet_twsk(sk)); |
| return; |
| } |
| seq = ntohl(th->seq); |
| if (sk->sk_state == TCP_NEW_SYN_RECV) |
| return tcp_req_err(sk, seq); |
| |
| 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_BH(net, LINUX_MIB_LOCKDROPPEDICMPS); |
| } |
| if (sk->sk_state == TCP_CLOSE) |
| goto out; |
| |
| if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
| NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); |
| goto out; |
| } |
| |
| icsk = inet_csk(sk); |
| tp = tcp_sk(sk); |
| /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */ |
| fastopen = 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_BH(net, LINUX_MIB_OUTOFWINDOWICMPS); |
| goto out; |
| } |
| |
| switch (type) { |
| case ICMP_REDIRECT: |
| do_redirect(icmp_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; |
| |
| 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, &tp->tsq_flags)) |
| sock_hold(sk); |
| } |
| goto out; |
| } |
| |
| err = icmp_err_convert[code].errno; |
| /* check if icmp_skb allows revert of backoff |
| * (see draft-zimmermann-tcp-lcd) */ |
| if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH) |
| break; |
| if (seq != tp->snd_una || !icsk->icsk_retransmits || |
| !icsk->icsk_backoff || fastopen) |
| break; |
| |
| if (sock_owned_by_user(sk)) |
| break; |
| |
| 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); |
| |
| skb = tcp_write_queue_head(sk); |
| BUG_ON(!skb); |
| |
| remaining = icsk->icsk_rto - |
| min(icsk->icsk_rto, |
| tcp_time_stamp - tcp_skb_timestamp(skb)); |
| |
| if (remaining) { |
| 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); |
| } |
| |
| 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 |
| * is already accepted it is treated as a connected one below. |
| */ |
| if (fastopen && !fastopen->sk) |
| break; |
| |
| if (!sock_owned_by_user(sk)) { |
| sk->sk_err = err; |
| |
| sk->sk_error_report(sk); |
| |
| tcp_done(sk); |
| } else { |
| 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) |
| */ |
| |
| inet = inet_sk(sk); |
| if (!sock_owned_by_user(sk) && inet->recverr) { |
| sk->sk_err = err; |
| sk->sk_error_report(sk); |
| } else { /* Only an error on timeout */ |
| sk->sk_err_soft = err; |
| } |
| |
| out: |
| bh_unlock_sock(sk); |
| sock_put(sk); |
| } |
| |
| void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr) |
| { |
| struct tcphdr *th = tcp_hdr(skb); |
| |
| if (skb->ip_summed == CHECKSUM_PARTIAL) { |
| 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); |
| } else { |
| th->check = tcp_v4_check(skb->len, saddr, daddr, |
| csum_partial(th, |
| th->doff << 2, |
| skb->csum)); |
| } |
| } |
| |
| /* 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); |
| |
| /* |
| * 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) |
| { |
| const struct tcphdr *th = tcp_hdr(skb); |
| struct { |
| struct tcphdr th; |
| #ifdef CONFIG_TCP_MD5SIG |
| __be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)]; |
| #endif |
| } rep; |
| struct ip_reply_arg arg; |
| #ifdef CONFIG_TCP_MD5SIG |
| struct tcp_md5sig_key *key; |
| const __u8 *hash_location = NULL; |
| unsigned char newhash[16]; |
| int genhash; |
| struct sock *sk1 = NULL; |
| #endif |
| struct net *net; |
| |
| /* 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); |
| #ifdef CONFIG_TCP_MD5SIG |
| hash_location = tcp_parse_md5sig_option(th); |
| if (!sk && hash_location) { |
| /* |
| * 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, |
| &tcp_hashinfo, ip_hdr(skb)->saddr, |
| th->source, ip_hdr(skb)->daddr, |
| ntohs(th->source), inet_iif(skb)); |
| /* don't send rst if it can't find key */ |
| if (!sk1) |
| return; |
| rcu_read_lock(); |
| key = tcp_md5_do_lookup(sk1, (union tcp_md5_addr *) |
| &ip_hdr(skb)->saddr, AF_INET); |
| if (!key) |
| goto release_sk1; |
| |
| genhash = tcp_v4_md5_hash_skb(newhash, key, NULL, skb); |
| if (genhash || memcmp(hash_location, newhash, 16) != 0) |
| goto release_sk1; |
| } else { |
| key = sk ? tcp_md5_do_lookup(sk, (union tcp_md5_addr *) |
| &ip_hdr(skb)->saddr, |
| AF_INET) : NULL; |
| } |
| |
| 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 |
| 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(sk)->transparent) ? 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; |
| |
| arg.tos = ip_hdr(skb)->tos; |
| ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk), |
| skb, &TCP_SKB_CB(skb)->header.h4.opt, |
| ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
| &arg, arg.iov[0].iov_len); |
| |
| TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); |
| TCP_INC_STATS_BH(net, TCP_MIB_OUTRSTS); |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| release_sk1: |
| if (sk1) { |
| rcu_read_unlock(); |
| sock_put(sk1); |
| } |
| #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(struct sk_buff *skb, u32 seq, u32 ack, |
| u32 win, u32 tsval, u32 tsecr, int oif, |
| struct tcp_md5sig_key *key, |
| int reply_flags, u8 tos) |
| { |
| const struct tcphdr *th = tcp_hdr(skb); |
| struct { |
| struct tcphdr th; |
| __be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2) |
| #ifdef CONFIG_TCP_MD5SIG |
| + (TCPOLEN_MD5SIG_ALIGNED >> 2) |
| #endif |
| ]; |
| } rep; |
| struct ip_reply_arg arg; |
| struct net *net = dev_net(skb_dst(skb)->dev); |
| |
| 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 (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, ip_hdr(skb)->saddr, |
| ip_hdr(skb)->daddr, &rep.th); |
| } |
| #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; |
| ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk), |
| skb, &TCP_SKB_CB(skb)->header.h4.opt, |
| ip_hdr(skb)->saddr, ip_hdr(skb)->daddr, |
| &arg, arg.iov[0].iov_len); |
| |
| TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS); |
| } |
| |
| 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); |
| |
| tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt, |
| tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale, |
| tcp_time_stamp + tcptw->tw_ts_offset, |
| tcptw->tw_ts_recent, |
| tw->tw_bound_dev_if, |
| tcp_twsk_md5_key(tcptw), |
| tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0, |
| tw->tw_tos |
| ); |
| |
| inet_twsk_put(tw); |
| } |
| |
| static void tcp_v4_reqsk_send_ack(const struct sock *sk, struct sk_buff *skb, |
| struct request_sock *req) |
| { |
| /* sk->sk_state == TCP_LISTEN -> for regular TCP_SYN_RECV |
| * sk->sk_state == TCP_SYN_RECV -> for Fast Open. |
| */ |
| tcp_v4_send_ack(skb, (sk->sk_state == TCP_LISTEN) ? |
| tcp_rsk(req)->snt_isn + 1 : tcp_sk(sk)->snd_nxt, |
| tcp_rsk(req)->rcv_nxt, req->rsk_rcv_wnd, |
| tcp_time_stamp, |
| req->ts_recent, |
| 0, |
| tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&ip_hdr(skb)->daddr, |
| AF_INET), |
| inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0, |
| ip_hdr(skb)->tos); |
| } |
| |
| /* |
| * 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, |
| bool attach_req) |
| { |
| const struct inet_request_sock *ireq = inet_rsk(req); |
| struct flowi4 fl4; |
| int err = -1; |
| struct sk_buff *skb; |
| |
| /* 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, attach_req); |
| |
| if (skb) { |
| __tcp_v4_send_check(skb, ireq->ir_loc_addr, ireq->ir_rmt_addr); |
| |
| err = ip_build_and_send_pkt(skb, sk, ireq->ir_loc_addr, |
| ireq->ir_rmt_addr, |
| ireq->opt); |
| err = net_xmit_eval(err); |
| } |
| |
| return err; |
| } |
| |
| /* |
| * IPv4 request_sock destructor. |
| */ |
| static void tcp_v4_reqsk_destructor(struct request_sock *req) |
| { |
| kfree(inet_rsk(req)->opt); |
| } |
| |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| /* |
| * RFC2385 MD5 checksumming requires a mapping of |
| * IP address->MD5 Key. |
| * We need to maintain these in the sk structure. |
| */ |
| |
| /* Find the Key structure for an address. */ |
| struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, |
| const union tcp_md5_addr *addr, |
| int family) |
| { |
| 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, |
| sock_owned_by_user(sk) || |
| lockdep_is_held((spinlock_t *)&sk->sk_lock.slock)); |
| 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) { |
| if (key->family != family) |
| continue; |
| if (!memcmp(&key->addr, addr, size)) |
| return key; |
| } |
| return NULL; |
| } |
| EXPORT_SYMBOL(tcp_md5_do_lookup); |
| |
| struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
| const struct sock *addr_sk) |
| { |
| const union tcp_md5_addr *addr; |
| |
| addr = (const union tcp_md5_addr *)&addr_sk->sk_daddr; |
| return tcp_md5_do_lookup(sk, addr, AF_INET); |
| } |
| EXPORT_SYMBOL(tcp_v4_md5_lookup); |
| |
| /* This can be called on a newly created socket, from other files */ |
| int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
| int family, 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(sk, addr, family); |
| if (key) { |
| /* Pre-existing entry - just update that one. */ |
| memcpy(key->key, newkey, newkeylen); |
| key->keylen = newkeylen; |
| return 0; |
| } |
| |
| md5sig = rcu_dereference_protected(tp->md5sig_info, |
| sock_owned_by_user(sk)); |
| if (!md5sig) { |
| md5sig = kmalloc(sizeof(*md5sig), gfp); |
| if (!md5sig) |
| return -ENOMEM; |
| |
| sk_nocaps_add(sk, NETIF_F_GSO_MASK); |
| INIT_HLIST_HEAD(&md5sig->head); |
| rcu_assign_pointer(tp->md5sig_info, md5sig); |
| } |
| |
| key = sock_kmalloc(sk, sizeof(*key), gfp); |
| if (!key) |
| return -ENOMEM; |
| if (!tcp_alloc_md5sig_pool()) { |
| sock_kfree_s(sk, key, sizeof(*key)); |
| return -ENOMEM; |
| } |
| |
| memcpy(key->key, newkey, newkeylen); |
| key->keylen = newkeylen; |
| key->family = family; |
| memcpy(&key->addr, addr, |
| (family == AF_INET6) ? sizeof(struct in6_addr) : |
| sizeof(struct in_addr)); |
| hlist_add_head_rcu(&key->node, &md5sig->head); |
| return 0; |
| } |
| EXPORT_SYMBOL(tcp_md5_do_add); |
| |
| int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, int family) |
| { |
| struct tcp_md5sig_key *key; |
| |
| key = tcp_md5_do_lookup(sk, addr, family); |
| 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); |
| |
| static 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, char __user *optval, |
| int optlen) |
| { |
| struct tcp_md5sig cmd; |
| struct sockaddr_in *sin = (struct sockaddr_in *)&cmd.tcpm_addr; |
| |
| if (optlen < sizeof(cmd)) |
| return -EINVAL; |
| |
| if (copy_from_user(&cmd, optval, sizeof(cmd))) |
| return -EFAULT; |
| |
| if (sin->sin_family != AF_INET) |
| return -EINVAL; |
| |
| if (!cmd.tcpm_keylen) |
| return tcp_md5_do_del(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, |
| AF_INET); |
| |
| if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN) |
| return -EINVAL; |
| |
| return tcp_md5_do_add(sk, (union tcp_md5_addr *)&sin->sin_addr.s_addr, |
| AF_INET, cmd.tcpm_key, cmd.tcpm_keylen, |
| GFP_KERNEL); |
| } |
| |
| static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp, |
| __be32 daddr, __be32 saddr, int nbytes) |
| { |
| struct tcp4_pseudohdr *bp; |
| struct scatterlist sg; |
| |
| bp = &hp->md5_blk.ip4; |
| |
| /* |
| * 1. the TCP pseudo-header (in the order: source IP address, |
| * destination IP address, zero-padded protocol number, and |
| * segment length) |
| */ |
| bp->saddr = saddr; |
| bp->daddr = daddr; |
| bp->pad = 0; |
| bp->protocol = IPPROTO_TCP; |
| bp->len = cpu_to_be16(nbytes); |
| |
| sg_init_one(&sg, bp, sizeof(*bp)); |
| return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp)); |
| } |
| |
| 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_md5sig_pool *hp; |
| struct hash_desc *desc; |
| |
| hp = tcp_get_md5sig_pool(); |
| if (!hp) |
| goto clear_hash_noput; |
| desc = &hp->md5_desc; |
| |
| if (crypto_hash_init(desc)) |
| goto clear_hash; |
| if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2)) |
| goto clear_hash; |
| if (tcp_md5_hash_header(hp, th)) |
| goto clear_hash; |
| if (tcp_md5_hash_key(hp, key)) |
| goto clear_hash; |
| if (crypto_hash_final(desc, md5_hash)) |
| goto clear_hash; |
| |
| tcp_put_md5sig_pool(); |
| return 0; |
| |
| clear_hash: |
| tcp_put_md5sig_pool(); |
| clear_hash_noput: |
| memset(md5_hash, 0, 16); |
| return 1; |
| } |
| |
| int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
| const struct sock *sk, |
| const struct sk_buff *skb) |
| { |
| struct tcp_md5sig_pool *hp; |
| struct hash_desc *desc; |
| const struct tcphdr *th = tcp_hdr(skb); |
| __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; |
| } |
| |
| hp = tcp_get_md5sig_pool(); |
| if (!hp) |
| goto clear_hash_noput; |
| desc = &hp->md5_desc; |
| |
| if (crypto_hash_init(desc)) |
| goto clear_hash; |
| |
| if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len)) |
| goto clear_hash; |
| if (tcp_md5_hash_header(hp, th)) |
| goto clear_hash; |
| if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2)) |
| goto clear_hash; |
| if (tcp_md5_hash_key(hp, key)) |
| goto clear_hash; |
| if (crypto_hash_final(desc, md5_hash)) |
| goto clear_hash; |
| |
| tcp_put_md5sig_pool(); |
| return 0; |
| |
| clear_hash: |
| tcp_put_md5sig_pool(); |
| clear_hash_noput: |
| memset(md5_hash, 0, 16); |
| return 1; |
| } |
| EXPORT_SYMBOL(tcp_v4_md5_hash_skb); |
| |
| #endif |
| |
| /* Called with rcu_read_lock() */ |
| static bool tcp_v4_inbound_md5_hash(const struct sock *sk, |
| const struct sk_buff *skb) |
| { |
| #ifdef CONFIG_TCP_MD5SIG |
| /* |
| * This gets called for each TCP segment that arrives |
| * so we want to be efficient. |
| * We have 3 drop cases: |
| * o No MD5 hash and one expected. |
| * o MD5 hash and we're not expecting one. |
| * o MD5 hash and its wrong. |
| */ |
| const __u8 *hash_location = NULL; |
| struct tcp_md5sig_key *hash_expected; |
| const struct iphdr *iph = ip_hdr(skb); |
| const struct tcphdr *th = tcp_hdr(skb); |
| int genhash; |
| unsigned char newhash[16]; |
| |
| hash_expected = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&iph->saddr, |
| AF_INET); |
| hash_location = tcp_parse_md5sig_option(th); |
| |
| /* We've parsed the options - do we have a hash? */ |
| if (!hash_expected && !hash_location) |
| return false; |
| |
| if (hash_expected && !hash_location) { |
| NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND); |
| return true; |
| } |
| |
| if (!hash_expected && hash_location) { |
| NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED); |
| return true; |
| } |
| |
| /* Okay, so this is hash_expected and hash_location - |
| * so we need to calculate the checksum. |
| */ |
| genhash = tcp_v4_md5_hash_skb(newhash, |
| hash_expected, |
| NULL, skb); |
| |
| if (genhash || memcmp(hash_location, newhash, 16) != 0) { |
| net_info_ratelimited("MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n", |
| &iph->saddr, ntohs(th->source), |
| &iph->daddr, ntohs(th->dest), |
| genhash ? " tcp_v4_calc_md5_hash failed" |
| : ""); |
| return true; |
| } |
| return false; |
| #endif |
| return false; |
| } |
| |
| 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); |
| |
| sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr); |
| sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr); |
| ireq->no_srccheck = inet_sk(sk_listener)->transparent; |
| ireq->opt = tcp_v4_save_options(skb); |
| } |
| |
| static struct dst_entry *tcp_v4_route_req(const struct sock *sk, |
| struct flowi *fl, |
| const struct request_sock *req, |
| bool *strict) |
| { |
| struct dst_entry *dst = inet_csk_route_req(sk, &fl->u.ip4, req); |
| |
| if (strict) { |
| if (fl->u.ip4.daddr == inet_rsk(req)->ir_rmt_addr) |
| *strict = true; |
| else |
| *strict = false; |
| } |
| |
| return dst; |
| } |
| |
| 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, |
| }; |
| |
| static 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 |
| .init_req = tcp_v4_init_req, |
| #ifdef CONFIG_SYN_COOKIES |
| .cookie_init_seq = cookie_v4_init_sequence, |
| #endif |
| .route_req = tcp_v4_route_req, |
| .init_seq = tcp_v4_init_sequence, |
| .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: |
| NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); |
| 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; |
| struct inet_sock *newinet; |
| struct tcp_sock *newtp; |
| struct sock *newsk; |
| #ifdef CONFIG_TCP_MD5SIG |
| struct tcp_md5sig_key *key; |
| #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); |
| newinet->inet_saddr = ireq->ir_loc_addr; |
| inet_opt = ireq->opt; |
| rcu_assign_pointer(newinet->inet_opt, inet_opt); |
| ireq->opt = NULL; |
| 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; |
| newinet->inet_id = newtp->write_seq ^ jiffies; |
| |
| 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 = dst_metric_advmss(dst); |
| if (tcp_sk(sk)->rx_opt.user_mss && |
| tcp_sk(sk)->rx_opt.user_mss < newtp->advmss) |
| newtp->advmss = tcp_sk(sk)->rx_opt.user_mss; |
| |
| tcp_initialize_rcv_mss(newsk); |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| /* Copy over the MD5 key from the original socket */ |
| key = tcp_md5_do_lookup(sk, (union tcp_md5_addr *)&newinet->inet_daddr, |
| AF_INET); |
| if (key) { |
| /* |
| * We're using one, so create a matching key |
| * on the newsk structure. If we fail to get |
| * memory, then we end up not copying the key |
| * across. Shucks. |
| */ |
| tcp_md5_do_add(newsk, (union tcp_md5_addr *)&newinet->inet_daddr, |
| AF_INET, key->key, key->keylen, GFP_ATOMIC); |
| sk_nocaps_add(newsk, NETIF_F_GSO_MASK); |
| } |
| #endif |
| |
| if (__inet_inherit_port(sk, newsk) < 0) |
| goto put_and_exit; |
| *own_req = inet_ehash_nolisten(newsk, req_to_sk(req_unhash)); |
| if (*own_req) |
| tcp_move_syn(newtp, req); |
| |
| return newsk; |
| |
| exit_overflow: |
| NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS); |
| exit_nonewsk: |
| dst_release(dst); |
| exit: |
| NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS); |
| return NULL; |
| put_and_exit: |
| 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; |
| } |
| |
| /* 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) |
| { |
| struct sock *rsk; |
| |
| if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */ |
| struct dst_entry *dst = sk->sk_rx_dst; |
| |
| sock_rps_save_rxhash(sk, skb); |
| sk_mark_napi_id(sk, skb); |
| if (dst) { |
| if (inet_sk(sk)->rx_dst_ifindex != skb->skb_iif || |
| !dst->ops->check(dst, 0)) { |
| dst_release(dst); |
| sk->sk_rx_dst = NULL; |
| } |
| } |
| tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len); |
| 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) |
| goto discard; |
| if (nsk != sk) { |
| sock_rps_save_rxhash(nsk, skb); |
| sk_mark_napi_id(nsk, skb); |
| if (tcp_child_process(sk, nsk, skb)) { |
| rsk = nsk; |
| goto reset; |
| } |
| return 0; |
| } |
| } else |
| sock_rps_save_rxhash(sk, skb); |
| |
| if (tcp_rcv_state_process(sk, skb)) { |
| rsk = sk; |
| goto reset; |
| } |
| return 0; |
| |
| reset: |
| tcp_v4_send_reset(rsk, skb); |
| discard: |
| kfree_skb(skb); |
| /* 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: |
| TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS); |
| TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS); |
| goto discard; |
| } |
| EXPORT_SYMBOL(tcp_v4_do_rcv); |
| |
| void tcp_v4_early_demux(struct sk_buff *skb) |
| { |
| const struct iphdr *iph; |
| const struct tcphdr *th; |
| struct sock *sk; |
| |
| if (skb->pkt_type != PACKET_HOST) |
| return; |
| |
| if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct tcphdr))) |
| return; |
| |
| iph = ip_hdr(skb); |
| th = tcp_hdr(skb); |
| |
| if (th->doff < sizeof(struct tcphdr) / 4) |
| return; |
| |
| sk = __inet_lookup_established(dev_net(skb->dev), &tcp_hashinfo, |
| iph->saddr, th->source, |
| iph->daddr, ntohs(th->dest), |
| skb->skb_iif); |
| if (sk) { |
| skb->sk = sk; |
| skb->destructor = sock_edemux; |
| if (sk_fullsock(sk)) { |
| struct dst_entry *dst = READ_ONCE(sk->sk_rx_dst); |
| |
| if (dst) |
| dst = dst_check(dst, 0); |
| if (dst && |
| inet_sk(sk)->rx_dst_ifindex == skb->skb_iif) |
| skb_dst_set_noref(skb, dst); |
| } |
| } |
| } |
| |
| /* Packet is added to VJ-style prequeue for processing in process |
| * context, if a reader task is waiting. Apparently, this exciting |
| * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) |
| * failed somewhere. Latency? Burstiness? Well, at least now we will |
| * see, why it failed. 8)8) --ANK |
| * |
| */ |
| bool tcp_prequeue(struct sock *sk, struct sk_buff *skb) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| if (sysctl_tcp_low_latency || !tp->ucopy.task) |
| return false; |
| |
| if (skb->len <= tcp_hdrlen(skb) && |
| skb_queue_len(&tp->ucopy.prequeue) == 0) |
| return false; |
| |
| /* Before escaping RCU protected region, we need to take care of skb |
| * dst. Prequeue is only enabled for established sockets. |
| * For such sockets, we might need the skb dst only to set sk->sk_rx_dst |
| * Instead of doing full sk_rx_dst validity here, let's perform |
| * an optimistic check. |
| */ |
| if (likely(sk->sk_rx_dst)) |
| skb_dst_drop(skb); |
| else |
| skb_dst_force(skb); |
| |
| __skb_queue_tail(&tp->ucopy.prequeue, skb); |
| tp->ucopy.memory += skb->truesize; |
| if (tp->ucopy.memory > sk->sk_rcvbuf) { |
| struct sk_buff *skb1; |
| |
| BUG_ON(sock_owned_by_user(sk)); |
| |
| while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) { |
| sk_backlog_rcv(sk, skb1); |
| NET_INC_STATS_BH(sock_net(sk), |
| LINUX_MIB_TCPPREQUEUEDROPPED); |
| } |
| |
| tp->ucopy.memory = 0; |
| } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { |
| wake_up_interruptible_sync_poll(sk_sleep(sk), |
| POLLIN | POLLRDNORM | POLLRDBAND); |
| if (!inet_csk_ack_scheduled(sk)) |
| inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
| (3 * tcp_rto_min(sk)) / 4, |
| TCP_RTO_MAX); |
| } |
| return true; |
| } |
| EXPORT_SYMBOL(tcp_prequeue); |
| |
| /* |
| * From tcp_input.c |
| */ |
| |
| int tcp_v4_rcv(struct sk_buff *skb) |
| { |
| const struct iphdr *iph; |
| const struct tcphdr *th; |
| struct sock *sk; |
| int ret; |
| struct net *net = dev_net(skb->dev); |
| |
| if (skb->pkt_type != PACKET_HOST) |
| goto discard_it; |
| |
| /* Count it even if it's bad */ |
| TCP_INC_STATS_BH(net, TCP_MIB_INSEGS); |
| |
| if (!pskb_may_pull(skb, sizeof(struct tcphdr))) |
| goto discard_it; |
| |
| th = tcp_hdr(skb); |
| |
| if (th->doff < sizeof(struct tcphdr) / 4) |
| 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 = tcp_hdr(skb); |
| iph = ip_hdr(skb); |
| /* 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)->tcp_tw_isn = 0; |
| TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph); |
| TCP_SKB_CB(skb)->sacked = 0; |
| |
| lookup: |
| sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest); |
| if (!sk) |
| goto no_tcp_socket; |
| |
| process: |
| if (sk->sk_state == TCP_TIME_WAIT) |
| goto do_time_wait; |
| |
| if (sk->sk_state == TCP_NEW_SYN_RECV) { |
| struct request_sock *req = inet_reqsk(sk); |
| struct sock *nsk = NULL; |
| |
| sk = req->rsk_listener; |
| if (tcp_v4_inbound_md5_hash(sk, skb)) |
| goto discard_and_relse; |
| if (likely(sk->sk_state == TCP_LISTEN)) { |
| nsk = tcp_check_req(sk, skb, req, false); |
| } else { |
| inet_csk_reqsk_queue_drop_and_put(sk, req); |
| goto lookup; |
| } |
| if (!nsk) { |
| reqsk_put(req); |
| goto discard_it; |
| } |
| if (nsk == sk) { |
| sock_hold(sk); |
| reqsk_put(req); |
| } else if (tcp_child_process(sk, nsk, skb)) { |
| tcp_v4_send_reset(nsk, skb); |
| goto discard_it; |
| } else { |
| return 0; |
| } |
| } |
| if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { |
| NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP); |
| goto discard_and_relse; |
| } |
| |
| if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
| goto discard_and_relse; |
| |
| if (tcp_v4_inbound_md5_hash(sk, skb)) |
| goto discard_and_relse; |
| |
| nf_reset(skb); |
| |
| if (sk_filter(sk, skb)) |
| goto discard_and_relse; |
| |
| 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_sk(sk)->segs_in += max_t(u16, 1, skb_shinfo(skb)->gso_segs); |
| ret = 0; |
| if (!sock_owned_by_user(sk)) { |
| if (!tcp_prequeue(sk, skb)) |
| ret = tcp_v4_do_rcv(sk, skb); |
| } else if (unlikely(sk_add_backlog(sk, skb, |
| sk->sk_rcvbuf + sk->sk_sndbuf))) { |
| bh_unlock_sock(sk); |
| NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP); |
| goto discard_and_relse; |
| } |
| bh_unlock_sock(sk); |
| |
| put_and_return: |
| sock_put(sk); |
| |
| return ret; |
| |
| no_tcp_socket: |
| if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) |
| goto discard_it; |
| |
| if (tcp_checksum_complete(skb)) { |
| csum_error: |
| TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS); |
| bad_packet: |
| TCP_INC_STATS_BH(net, TCP_MIB_INERRS); |
| } else { |
| tcp_v4_send_reset(NULL, skb); |
| } |
| |
| discard_it: |
| /* Discard frame. */ |
| kfree_skb(skb); |
| return 0; |
| |
| discard_and_relse: |
| sock_put(sk); |
| goto discard_it; |
| |
| do_time_wait: |
| if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| inet_twsk_put(inet_twsk(sk)); |
| goto discard_it; |
| } |
| |
| if (tcp_checksum_complete(skb)) { |
| inet_twsk_put(inet_twsk(sk)); |
| goto csum_error; |
| } |
| switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) { |
| case TCP_TW_SYN: { |
| struct sock *sk2 = inet_lookup_listener(dev_net(skb->dev), |
| &tcp_hashinfo, |
| iph->saddr, th->source, |
| iph->daddr, th->dest, |
| inet_iif(skb)); |
| if (sk2) { |
| inet_twsk_deschedule_put(inet_twsk(sk)); |
| sk = sk2; |
| goto process; |
| } |
| /* Fall through to ACK */ |
| } |
| case TCP_TW_ACK: |
| tcp_v4_timewait_ack(sk, skb); |
| break; |
| case TCP_TW_RST: |
| goto no_tcp_socket; |
| 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_unique = tcp_twsk_unique, |
| .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(dst); |
| sk->sk_rx_dst = dst; |
| inet_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), |
| .bind_conflict = inet_csk_bind_conflict, |
| #ifdef CONFIG_COMPAT |
| .compat_setsockopt = compat_ip_setsockopt, |
| .compat_getsockopt = compat_ip_getsockopt, |
| #endif |
| .mtu_reduced = tcp_v4_mtu_reduced, |
| }; |
| EXPORT_SYMBOL(ipv4_specific); |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = { |
| .md5_lookup = tcp_v4_md5_lookup, |
| .calc_md5_hash = tcp_v4_md5_hash_skb, |
| .md5_parse = tcp_v4_parse_md5_keys, |
| }; |
| #endif |
| |
| /* NOTE: A lot of things set to zero explicitly by call to |
| * sk_alloc() so need not be done here. |
| */ |
| static int tcp_v4_init_sock(struct sock *sk) |
| { |
| struct inet_connection_sock *icsk = inet_csk(sk); |
| |
| tcp_init_sock(sk); |
| |
| icsk->icsk_af_ops = &ipv4_specific; |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| tcp_sk(sk)->af_specific = &tcp_sock_ipv4_specific; |
| #endif |
| |
| return 0; |
| } |
| |
| void tcp_v4_destroy_sock(struct sock *sk) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| tcp_clear_xmit_timers(sk); |
| |
| tcp_cleanup_congestion_control(sk); |
| |
| /* Cleanup up the write buffer. */ |
| tcp_write_queue_purge(sk); |
| |
| /* Cleans up our, hopefully empty, out_of_order_queue. */ |
| __skb_queue_purge(&tp->out_of_order_queue); |
| |
| #ifdef CONFIG_TCP_MD5SIG |
| /* Clean up the MD5 key list, if any */ |
| if (tp->md5sig_info) { |
| tcp_clear_md5_list(sk); |
| kfree_rcu(tp->md5sig_info, rcu); |
| tp->md5sig_info = NULL; |
| } |
| #endif |
| |
| /* Clean prequeue, it must be empty really */ |
| __skb_queue_purge(&tp->ucopy.prequeue); |
| |
| /* Clean up a referenced TCP bind bucket. */ |
| if (inet_csk(sk)->icsk_bind_hash) |
| inet_put_port(sk); |
| |
| BUG_ON(tp->fastopen_rsk); |
| |
| /* If socket is aborted during connect operation */ |
| tcp_free_fastopen_req(tp); |
| tcp_saved_syn_free(tp); |
| |
| sk_sockets_allocated_dec(sk); |
| sock_release_memcg(sk); |
| } |
| EXPORT_SYMBOL(tcp_v4_destroy_sock); |
| |
| #ifdef CONFIG_PROC_FS |
| /* Proc filesystem TCP sock list dumping. */ |
| |
| /* |
| * Get next listener socket follow cur. If cur is NULL, get first socket |
| * starting from bucket given in st->bucket; when st->bucket is zero the |
| * very first socket in the hash table is returned. |
| */ |
| static void *listening_get_next(struct seq_file *seq, void *cur) |
| { |
| struct inet_connection_sock *icsk; |
| struct hlist_nulls_node *node; |
| struct sock *sk = cur; |
| struct inet_listen_hashbucket *ilb; |
| struct tcp_iter_state *st = seq->private; |
| struct net *net = seq_file_net(seq); |
| |
| if (!sk) { |
| ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
| spin_lock_bh(&ilb->lock); |
| sk = sk_nulls_head(&ilb->head); |
| st->offset = 0; |
| goto get_sk; |
| } |
| ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
| ++st->num; |
| ++st->offset; |
| |
| sk = sk_nulls_next(sk); |
| get_sk: |
| sk_nulls_for_each_from(sk, node) { |
| if (!net_eq(sock_net(sk), net)) |
| continue; |
| if (sk->sk_family == st->family) { |
| cur = sk; |
| goto out; |
| } |
| icsk = inet_csk(sk); |
| } |
| spin_unlock_bh(&ilb->lock); |
| st->offset = 0; |
| if (++st->bucket < INET_LHTABLE_SIZE) { |
| ilb = &tcp_hashinfo.listening_hash[st->bucket]; |
| spin_lock_bh(&ilb->lock); |
| sk = sk_nulls_head(&ilb->head); |
| goto get_sk; |
| } |
| cur = NULL; |
| out: |
| return cur; |
| } |
| |
| 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_next(seq, NULL); |
| |
| while (rc && *pos) { |
| rc = listening_get_next(seq, rc); |
| --*pos; |
| } |
| return rc; |
| } |
| |
| static inline bool empty_bucket(const struct tcp_iter_state *st) |
| { |
| return hlist_nulls_empty(&tcp_hashinfo.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 tcp_iter_state *st = seq->private; |
| struct net *net = seq_file_net(seq); |
| void *rc = NULL; |
| |
| st->offset = 0; |
| for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) { |
| struct sock *sk; |
| struct hlist_nulls_node *node; |
| spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket); |
| |
| /* Lockless fast path for the common case of empty buckets */ |
| if (empty_bucket(st)) |
| continue; |
| |
| spin_lock_bh(lock); |
| sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) { |
| if (sk->sk_family != st->family || |
| !net_eq(sock_net(sk), net)) { |
| continue; |
| } |
| rc = sk; |
| goto out; |
| } |
| spin_unlock_bh(lock); |
| } |
| out: |
| return rc; |
| } |
| |
| static void *established_get_next(struct seq_file *seq, void *cur) |
| { |
| struct sock *sk = cur; |
| struct hlist_nulls_node *node; |
| struct tcp_iter_state *st = seq->private; |
| struct net *net = seq_file_net(seq); |
| |
| ++st->num; |
| ++st->offset; |
| |
| sk = sk_nulls_next(sk); |
| |
| sk_nulls_for_each_from(sk, node) { |
| if (sk->sk_family == st->family && net_eq(sock_net(sk), net)) |
| return sk; |
| } |
| |
| spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, 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 tcp_iter_state *st = seq->private; |
| int offset = st->offset; |
| int orig_num = st->num; |
| void *rc = NULL; |
| |
| switch (st->state) { |
| case TCP_SEQ_STATE_LISTENING: |
| if (st->bucket >= INET_LHTABLE_SIZE) |
| break; |
| st->state = TCP_SEQ_STATE_LISTENING; |
| rc = listening_get_next(seq, NULL); |
| while (offset-- && rc) |
| 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 > tcp_hashinfo.ehash_mask) |
| break; |
| rc = established_get_first(seq); |
| while (offset-- && rc) |
| rc = established_get_next(seq, rc); |
| } |
| |
| st->num = orig_num; |
| |
| return rc; |
| } |
| |
| static 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; |
| } |
| |
| static 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; |
| } |
| |
| static void tcp_seq_stop(struct seq_file *seq, void *v) |
| { |
| struct tcp_iter_state *st = seq->private; |
| |
| switch (st->state) { |
| case TCP_SEQ_STATE_LISTENING: |
| if (v != SEQ_START_TOKEN) |
| spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock); |
| break; |
| case TCP_SEQ_STATE_ESTABLISHED: |
| if (v) |
| spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); |
| break; |
| } |
| } |
| |
| int tcp_seq_open(struct inode *inode, struct file *file) |
| { |
| struct tcp_seq_afinfo *afinfo = PDE_DATA(inode); |
| struct tcp_iter_state *s; |
| int err; |
| |
| err = seq_open_net(inode, file, &afinfo->seq_ops, |
| sizeof(struct tcp_iter_state)); |
| if (err < 0) |
| return err; |
| |
| s = ((struct seq_file *)file->private_data)->private; |
| s->family = afinfo->family; |
| s->last_pos = 0; |
| return 0; |
| } |
| EXPORT_SYMBOL(tcp_seq_open); |
| |
| int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo) |
| { |
| int rc = 0; |
| struct proc_dir_entry *p; |
| |
| afinfo->seq_ops.start = tcp_seq_start; |
| afinfo->seq_ops.next = tcp_seq_next; |
| afinfo->seq_ops.stop = tcp_seq_stop; |
| |
| p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, |
| afinfo->seq_fops, afinfo); |
| if (!p) |
| rc = -ENOMEM; |
| return rc; |
| } |
| EXPORT_SYMBOL(tcp_proc_register); |
| |
| void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo) |
| { |
| remove_proc_entry(afinfo->name, net->proc_net); |
| } |
| EXPORT_SYMBOL(tcp_proc_unregister); |
| |
| 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_EARLY_RETRANS || |
| 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 = sk_state_load(sk); |
| if (state == TCP_LISTEN) |
| rx_queue = sk->sk_ack_backlog; |
| else |
| /* Because we don't lock the socket, |
| * we might find a transient negative value. |
| */ |
| rx_queue = max_t(int, tp->rcv_nxt - 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, |
| 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), |
| atomic_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) | icsk->icsk_ack.pingpong, |
| tp->snd_cwnd, |
| 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, |
| atomic_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; |
| } |
| |
| static const struct file_operations tcp_afinfo_seq_fops = { |
| .owner = THIS_MODULE, |
| .open = tcp_seq_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_net |
| }; |
| |
| static struct tcp_seq_afinfo tcp4_seq_afinfo = { |
| .name = "tcp", |
| .family = AF_INET, |
| .seq_fops = &tcp_afinfo_seq_fops, |
| .seq_ops = { |
| .show = tcp4_seq_show, |
| }, |
| }; |
| |
| static int __net_init tcp4_proc_init_net(struct net *net) |
| { |
| return tcp_proc_register(net, &tcp4_seq_afinfo); |
| } |
| |
| static void __net_exit tcp4_proc_exit_net(struct net *net) |
| { |
| tcp_proc_unregister(net, &tcp4_seq_afinfo); |
| } |
| |
| static struct pernet_operations tcp4_net_ops = { |
| .init = tcp4_proc_init_net, |
| .exit = tcp4_proc_exit_net, |
| }; |
| |
| int __init tcp4_proc_init(void) |
| { |
| return register_pernet_subsys(&tcp4_net_ops); |
| } |
| |
| void tcp4_proc_exit(void) |
| { |
| unregister_pernet_subsys(&tcp4_net_ops); |
| } |
| #endif /* CONFIG_PROC_FS */ |
| |
| struct proto tcp_prot = { |
| .name = "TCP", |
| .owner = THIS_MODULE, |
| .close = tcp_close, |
| .connect = tcp_v4_connect, |
| .disconnect = tcp_disconnect, |
| .accept = inet_csk_accept, |
| .ioctl = tcp_ioctl, |
| .init = tcp_v4_init_sock, |
| .destroy = tcp_v4_destroy_sock, |
| .shutdown = tcp_shutdown, |
| .setsockopt = tcp_setsockopt, |
| .getsockopt = tcp_getsockopt, |
| .recvmsg = tcp_recvmsg, |
| .sendmsg = tcp_sendmsg, |
| .sendpage = tcp_sendpage, |
| .backlog_rcv = tcp_v4_do_rcv, |
| .release_cb = tcp_release_cb, |
| .hash = inet_hash, |
| .unhash = inet_unhash, |
| .get_port = inet_csk_get_port, |
| .enter_memory_pressure = tcp_enter_memory_pressure, |
| .stream_memory_free = tcp_stream_memory_free, |
| .sockets_allocated = &tcp_sockets_allocated, |
| .orphan_count = &tcp_orphan_count, |
| .memory_allocated = &tcp_memory_allocated, |
| .memory_pressure = &tcp_memory_pressure, |
| .sysctl_mem = sysctl_tcp_mem, |
| .sysctl_wmem = sysctl_tcp_wmem, |
| .sysctl_rmem = sysctl_tcp_rmem, |
| .max_header = MAX_TCP_HEADER, |
| .obj_size = sizeof(struct tcp_sock), |
| .slab_flags = SLAB_DESTROY_BY_RCU, |
| .twsk_prot = &tcp_timewait_sock_ops, |
| .rsk_prot = &tcp_request_sock_ops, |
| .h.hashinfo = &tcp_hashinfo, |
| .no_autobind = true, |
| #ifdef CONFIG_COMPAT |
| .compat_setsockopt = compat_tcp_setsockopt, |
| .compat_getsockopt = compat_tcp_getsockopt, |
| #endif |
| #ifdef CONFIG_MEMCG_KMEM |
| .init_cgroup = tcp_init_cgroup, |
| .destroy_cgroup = tcp_destroy_cgroup, |
| .proto_cgroup = tcp_proto_cgroup, |
| #endif |
| }; |
| EXPORT_SYMBOL(tcp_prot); |
| |
| static void __net_exit tcp_sk_exit(struct net *net) |
| { |
| int cpu; |
| |
| for_each_possible_cpu(cpu) |
| inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv4.tcp_sk, cpu)); |
| free_percpu(net->ipv4.tcp_sk); |
| } |
| |
| static int __net_init tcp_sk_init(struct net *net) |
| { |
| int res, cpu; |
| |
| net->ipv4.tcp_sk = alloc_percpu(struct sock *); |
| if (!net->ipv4.tcp_sk) |
| return -ENOMEM; |
| |
| for_each_possible_cpu(cpu) { |
| struct sock *sk; |
| |
| res = inet_ctl_sock_create(&sk, PF_INET, SOCK_RAW, |
| IPPROTO_TCP, net); |
| if (res) |
| goto fail; |
| *per_cpu_ptr(net->ipv4.tcp_sk, cpu) = sk; |
| } |
| |
| net->ipv4.sysctl_tcp_ecn = 2; |
| net->ipv4.sysctl_tcp_ecn_fallback = 1; |
| |
| net->ipv4.sysctl_tcp_base_mss = TCP_BASE_MSS; |
| net->ipv4.sysctl_tcp_probe_threshold = TCP_PROBE_THRESHOLD; |
| net->ipv4.sysctl_tcp_probe_interval = TCP_PROBE_INTERVAL; |
| |
| return 0; |
| fail: |
| tcp_sk_exit(net); |
| |
| return res; |
| } |
| |
| static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list) |
| { |
| inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET); |
| } |
| |
| static struct pernet_operations __net_initdata tcp_sk_ops = { |
| .init = tcp_sk_init, |
| .exit = tcp_sk_exit, |
| .exit_batch = tcp_sk_exit_batch, |
| }; |
| |
| void __init tcp_v4_init(void) |
| { |
| inet_hashinfo_init(&tcp_hashinfo); |
| if (register_pernet_subsys(&tcp_sk_ops)) |
| panic("Failed to create the TCP control socket.\n"); |
| } |