![YOSHIFUJI Hideaki](/assets/img/avatar_default.png)
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2479 lines
61 KiB
C
2479 lines
61 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Implementation of the Transmission Control Protocol(TCP).
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*
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* Version: $Id: tcp_ipv4.c,v 1.240 2002/02/01 22:01:04 davem Exp $
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*
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* IPv4 specific functions
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*
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*
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* code split from:
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* linux/ipv4/tcp.c
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* linux/ipv4/tcp_input.c
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* linux/ipv4/tcp_output.c
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*
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* See tcp.c for author information
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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/*
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* Changes:
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* David S. Miller : New socket lookup architecture.
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* This code is dedicated to John Dyson.
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* David S. Miller : Change semantics of established hash,
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* half is devoted to TIME_WAIT sockets
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* and the rest go in the other half.
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* Andi Kleen : Add support for syncookies and fixed
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* some bugs: ip options weren't passed to
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* the TCP layer, missed a check for an
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* ACK bit.
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* Andi Kleen : Implemented fast path mtu discovery.
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* Fixed many serious bugs in the
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* request_sock handling and moved
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* most of it into the af independent code.
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* Added tail drop and some other bugfixes.
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* Added new listen semantics.
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* Mike McLagan : Routing by source
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* Juan Jose Ciarlante: ip_dynaddr bits
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* Andi Kleen: various fixes.
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* Vitaly E. Lavrov : Transparent proxy revived after year
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* coma.
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* Andi Kleen : Fix new listen.
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* Andi Kleen : Fix accept error reporting.
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* YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
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* Alexey Kuznetsov allow both IPv4 and IPv6 sockets to bind
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* a single port at the same time.
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*/
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#include <linux/types.h>
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#include <linux/fcntl.h>
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#include <linux/module.h>
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#include <linux/random.h>
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#include <linux/cache.h>
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#include <linux/jhash.h>
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#include <linux/init.h>
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#include <linux/times.h>
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#include <net/icmp.h>
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#include <net/inet_hashtables.h>
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#include <net/tcp.h>
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#include <net/transp_v6.h>
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#include <net/ipv6.h>
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#include <net/inet_common.h>
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#include <net/timewait_sock.h>
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#include <net/xfrm.h>
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#include <net/netdma.h>
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#include <linux/inet.h>
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#include <linux/ipv6.h>
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#include <linux/stddef.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/crypto.h>
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#include <linux/scatterlist.h>
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int sysctl_tcp_tw_reuse __read_mostly;
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int sysctl_tcp_low_latency __read_mostly;
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/* Check TCP sequence numbers in ICMP packets. */
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#define ICMP_MIN_LENGTH 8
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/* Socket used for sending RSTs */
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static struct socket *tcp_socket;
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void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
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#ifdef CONFIG_TCP_MD5SIG
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static struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk,
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__be32 addr);
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static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
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__be32 saddr, __be32 daddr,
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struct tcphdr *th, int protocol,
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int tcplen);
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#endif
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struct inet_hashinfo __cacheline_aligned tcp_hashinfo = {
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.lhash_lock = __RW_LOCK_UNLOCKED(tcp_hashinfo.lhash_lock),
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.lhash_users = ATOMIC_INIT(0),
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.lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait),
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};
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static int tcp_v4_get_port(struct sock *sk, unsigned short snum)
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{
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return inet_csk_get_port(&tcp_hashinfo, sk, snum,
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inet_csk_bind_conflict);
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}
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static void tcp_v4_hash(struct sock *sk)
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{
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inet_hash(&tcp_hashinfo, sk);
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}
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void tcp_unhash(struct sock *sk)
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{
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inet_unhash(&tcp_hashinfo, sk);
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}
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static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb)
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{
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return secure_tcp_sequence_number(skb->nh.iph->daddr,
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skb->nh.iph->saddr,
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skb->h.th->dest,
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skb->h.th->source);
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}
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int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
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{
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const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
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struct tcp_sock *tp = tcp_sk(sk);
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/* With PAWS, it is safe from the viewpoint
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of data integrity. Even without PAWS it is safe provided sequence
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spaces do not overlap i.e. at data rates <= 80Mbit/sec.
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Actually, the idea is close to VJ's one, only timestamp cache is
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held not per host, but per port pair and TW bucket is used as state
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holder.
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If TW bucket has been already destroyed we fall back to VJ's scheme
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and use initial timestamp retrieved from peer table.
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*/
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if (tcptw->tw_ts_recent_stamp &&
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(twp == NULL || (sysctl_tcp_tw_reuse &&
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xtime.tv_sec - tcptw->tw_ts_recent_stamp > 1))) {
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tp->write_seq = tcptw->tw_snd_nxt + 65535 + 2;
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if (tp->write_seq == 0)
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tp->write_seq = 1;
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tp->rx_opt.ts_recent = tcptw->tw_ts_recent;
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tp->rx_opt.ts_recent_stamp = tcptw->tw_ts_recent_stamp;
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sock_hold(sktw);
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return 1;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(tcp_twsk_unique);
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/* This will initiate an outgoing connection. */
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int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
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{
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struct inet_sock *inet = inet_sk(sk);
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struct tcp_sock *tp = tcp_sk(sk);
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struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
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struct rtable *rt;
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__be32 daddr, nexthop;
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int tmp;
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int err;
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if (addr_len < sizeof(struct sockaddr_in))
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return -EINVAL;
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if (usin->sin_family != AF_INET)
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return -EAFNOSUPPORT;
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nexthop = daddr = usin->sin_addr.s_addr;
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if (inet->opt && inet->opt->srr) {
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if (!daddr)
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return -EINVAL;
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nexthop = inet->opt->faddr;
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}
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tmp = ip_route_connect(&rt, nexthop, inet->saddr,
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RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
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IPPROTO_TCP,
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inet->sport, usin->sin_port, sk, 1);
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if (tmp < 0)
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return tmp;
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if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
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ip_rt_put(rt);
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return -ENETUNREACH;
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}
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if (!inet->opt || !inet->opt->srr)
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daddr = rt->rt_dst;
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if (!inet->saddr)
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inet->saddr = rt->rt_src;
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inet->rcv_saddr = inet->saddr;
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if (tp->rx_opt.ts_recent_stamp && inet->daddr != daddr) {
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/* Reset inherited state */
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tp->rx_opt.ts_recent = 0;
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tp->rx_opt.ts_recent_stamp = 0;
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tp->write_seq = 0;
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}
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if (tcp_death_row.sysctl_tw_recycle &&
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!tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
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struct inet_peer *peer = rt_get_peer(rt);
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/*
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* VJ's idea. We save last timestamp seen from
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* the destination in peer table, when entering state
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* TIME-WAIT * and initialize rx_opt.ts_recent from it,
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* when trying new connection.
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*/
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if (peer != NULL &&
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peer->tcp_ts_stamp + TCP_PAWS_MSL >= xtime.tv_sec) {
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tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
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tp->rx_opt.ts_recent = peer->tcp_ts;
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}
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}
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inet->dport = usin->sin_port;
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inet->daddr = daddr;
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inet_csk(sk)->icsk_ext_hdr_len = 0;
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if (inet->opt)
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inet_csk(sk)->icsk_ext_hdr_len = inet->opt->optlen;
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tp->rx_opt.mss_clamp = 536;
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/* Socket identity is still unknown (sport may be zero).
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* However we set state to SYN-SENT and not releasing socket
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* lock select source port, enter ourselves into the hash tables and
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* complete initialization after this.
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*/
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tcp_set_state(sk, TCP_SYN_SENT);
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err = inet_hash_connect(&tcp_death_row, sk);
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if (err)
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goto failure;
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err = ip_route_newports(&rt, IPPROTO_TCP,
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inet->sport, inet->dport, sk);
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if (err)
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goto failure;
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/* OK, now commit destination to socket. */
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sk->sk_gso_type = SKB_GSO_TCPV4;
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sk_setup_caps(sk, &rt->u.dst);
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if (!tp->write_seq)
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tp->write_seq = secure_tcp_sequence_number(inet->saddr,
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inet->daddr,
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inet->sport,
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usin->sin_port);
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inet->id = tp->write_seq ^ jiffies;
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err = tcp_connect(sk);
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rt = NULL;
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if (err)
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goto failure;
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return 0;
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failure:
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/*
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* This unhashes the socket and releases the local port,
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* if necessary.
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*/
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tcp_set_state(sk, TCP_CLOSE);
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ip_rt_put(rt);
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sk->sk_route_caps = 0;
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inet->dport = 0;
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return err;
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}
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/*
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* This routine does path mtu discovery as defined in RFC1191.
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*/
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static void do_pmtu_discovery(struct sock *sk, struct iphdr *iph, u32 mtu)
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{
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struct dst_entry *dst;
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struct inet_sock *inet = inet_sk(sk);
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/* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
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* send out by Linux are always <576bytes so they should go through
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* unfragmented).
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*/
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if (sk->sk_state == TCP_LISTEN)
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return;
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/* We don't check in the destentry if pmtu discovery is forbidden
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* on this route. We just assume that no packet_to_big packets
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* are send back when pmtu discovery is not active.
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* There is a small race when the user changes this flag in the
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* route, but I think that's acceptable.
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*/
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if ((dst = __sk_dst_check(sk, 0)) == NULL)
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return;
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dst->ops->update_pmtu(dst, mtu);
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/* Something is about to be wrong... Remember soft error
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* for the case, if this connection will not able to recover.
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*/
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if (mtu < dst_mtu(dst) && ip_dont_fragment(sk, dst))
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sk->sk_err_soft = EMSGSIZE;
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mtu = dst_mtu(dst);
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if (inet->pmtudisc != IP_PMTUDISC_DONT &&
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inet_csk(sk)->icsk_pmtu_cookie > mtu) {
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tcp_sync_mss(sk, mtu);
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/* Resend the TCP packet because it's
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* clear that the old packet has been
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* dropped. This is the new "fast" path mtu
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* discovery.
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*/
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tcp_simple_retransmit(sk);
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} /* else let the usual retransmit timer handle it */
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}
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|
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/*
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* This routine is called by the ICMP module when it gets some
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* sort of error condition. If err < 0 then the socket should
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* be closed and the error returned to the user. If err > 0
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* it's just the icmp type << 8 | icmp code. After adjustment
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* header points to the first 8 bytes of the tcp header. We need
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* to find the appropriate port.
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*
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* The locking strategy used here is very "optimistic". When
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* someone else accesses the socket the ICMP is just dropped
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* and for some paths there is no check at all.
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* A more general error queue to queue errors for later handling
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* is probably better.
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*
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*/
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void tcp_v4_err(struct sk_buff *skb, u32 info)
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{
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struct iphdr *iph = (struct iphdr *)skb->data;
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struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2));
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struct tcp_sock *tp;
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struct inet_sock *inet;
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int type = skb->h.icmph->type;
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int code = skb->h.icmph->code;
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struct sock *sk;
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__u32 seq;
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int err;
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if (skb->len < (iph->ihl << 2) + 8) {
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ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
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return;
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}
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sk = inet_lookup(&tcp_hashinfo, iph->daddr, th->dest, iph->saddr,
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th->source, inet_iif(skb));
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if (!sk) {
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ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
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return;
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}
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if (sk->sk_state == TCP_TIME_WAIT) {
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inet_twsk_put(inet_twsk(sk));
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return;
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}
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|
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bh_lock_sock(sk);
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/* If too many ICMPs get dropped on busy
|
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* servers this needs to be solved differently.
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*/
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if (sock_owned_by_user(sk))
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NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
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|
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if (sk->sk_state == TCP_CLOSE)
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goto out;
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|
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tp = tcp_sk(sk);
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seq = ntohl(th->seq);
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if (sk->sk_state != TCP_LISTEN &&
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!between(seq, tp->snd_una, tp->snd_nxt)) {
|
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NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
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goto out;
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}
|
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|
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switch (type) {
|
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case ICMP_SOURCE_QUENCH:
|
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/* Just silently ignore these. */
|
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goto out;
|
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case ICMP_PARAMETERPROB:
|
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err = EPROTO;
|
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break;
|
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case ICMP_DEST_UNREACH:
|
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if (code > NR_ICMP_UNREACH)
|
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goto out;
|
|
|
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if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
|
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if (!sock_owned_by_user(sk))
|
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do_pmtu_discovery(sk, iph, info);
|
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goto out;
|
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}
|
|
|
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err = icmp_err_convert[code].errno;
|
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break;
|
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case ICMP_TIME_EXCEEDED:
|
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err = EHOSTUNREACH;
|
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break;
|
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default:
|
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goto out;
|
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}
|
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|
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switch (sk->sk_state) {
|
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struct request_sock *req, **prev;
|
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case TCP_LISTEN:
|
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if (sock_owned_by_user(sk))
|
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goto out;
|
|
|
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req = inet_csk_search_req(sk, &prev, th->dest,
|
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iph->daddr, iph->saddr);
|
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if (!req)
|
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goto out;
|
|
|
|
/* ICMPs are not backlogged, hence we cannot get
|
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an established socket here.
|
|
*/
|
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BUG_TRAP(!req->sk);
|
|
|
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if (seq != tcp_rsk(req)->snt_isn) {
|
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NET_INC_STATS_BH(LINUX_MIB_OUTOFWINDOWICMPS);
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* 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(sk, req, prev);
|
|
goto out;
|
|
|
|
case TCP_SYN_SENT:
|
|
case TCP_SYN_RECV: /* Cannot happen.
|
|
It can f.e. if SYNs crossed.
|
|
*/
|
|
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);
|
|
}
|
|
|
|
/* This routine computes an IPv4 TCP checksum. */
|
|
void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct tcphdr *th = skb->h.th;
|
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL) {
|
|
th->check = ~tcp_v4_check(len, inet->saddr,
|
|
inet->daddr, 0);
|
|
skb->csum_offset = offsetof(struct tcphdr, check);
|
|
} else {
|
|
th->check = tcp_v4_check(len, inet->saddr, inet->daddr,
|
|
csum_partial((char *)th,
|
|
th->doff << 2,
|
|
skb->csum));
|
|
}
|
|
}
|
|
|
|
int tcp_v4_gso_send_check(struct sk_buff *skb)
|
|
{
|
|
struct iphdr *iph;
|
|
struct tcphdr *th;
|
|
|
|
if (!pskb_may_pull(skb, sizeof(*th)))
|
|
return -EINVAL;
|
|
|
|
iph = skb->nh.iph;
|
|
th = skb->h.th;
|
|
|
|
th->check = 0;
|
|
th->check = ~tcp_v4_check(skb->len, iph->saddr, iph->daddr, 0);
|
|
skb->csum_offset = offsetof(struct tcphdr, check);
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct tcphdr *th = skb->h.th;
|
|
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;
|
|
#endif
|
|
|
|
/* Never send a reset in response to a reset. */
|
|
if (th->rst)
|
|
return;
|
|
|
|
if (((struct rtable *)skb->dst)->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);
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
key = sk ? tcp_v4_md5_do_lookup(sk, skb->nh.iph->daddr) : 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_do_calc_md5_hash((__u8 *)&rep.opt[1],
|
|
key,
|
|
skb->nh.iph->daddr,
|
|
skb->nh.iph->saddr,
|
|
&rep.th, IPPROTO_TCP,
|
|
arg.iov[0].iov_len);
|
|
}
|
|
#endif
|
|
arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr,
|
|
skb->nh.iph->saddr, /* XXX */
|
|
sizeof(struct tcphdr), IPPROTO_TCP, 0);
|
|
arg.csumoffset = offsetof(struct tcphdr, check) / 2;
|
|
|
|
ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len);
|
|
|
|
TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);
|
|
TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);
|
|
}
|
|
|
|
/* 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 tcp_timewait_sock *twsk,
|
|
struct sk_buff *skb, u32 seq, u32 ack,
|
|
u32 win, u32 ts)
|
|
{
|
|
struct tcphdr *th = skb->h.th;
|
|
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;
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
struct tcp_md5sig_key *key;
|
|
struct tcp_md5sig_key tw_key;
|
|
#endif
|
|
|
|
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 (ts) {
|
|
rep.opt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
|
|
(TCPOPT_TIMESTAMP << 8) |
|
|
TCPOLEN_TIMESTAMP);
|
|
rep.opt[1] = htonl(tcp_time_stamp);
|
|
rep.opt[2] = htonl(ts);
|
|
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
|
|
/*
|
|
* The SKB holds an imcoming packet, but may not have a valid ->sk
|
|
* pointer. This is especially the case when we're dealing with a
|
|
* TIME_WAIT ack, because the sk structure is long gone, and only
|
|
* the tcp_timewait_sock remains. So the md5 key is stashed in that
|
|
* structure, and we use it in preference. I believe that (twsk ||
|
|
* skb->sk) holds true, but we program defensively.
|
|
*/
|
|
if (!twsk && skb->sk) {
|
|
key = tcp_v4_md5_do_lookup(skb->sk, skb->nh.iph->daddr);
|
|
} else if (twsk && twsk->tw_md5_keylen) {
|
|
tw_key.key = twsk->tw_md5_key;
|
|
tw_key.keylen = twsk->tw_md5_keylen;
|
|
key = &tw_key;
|
|
} else
|
|
key = NULL;
|
|
|
|
if (key) {
|
|
int offset = (ts) ? 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_do_calc_md5_hash((__u8 *)&rep.opt[offset],
|
|
key,
|
|
skb->nh.iph->daddr,
|
|
skb->nh.iph->saddr,
|
|
&rep.th, IPPROTO_TCP,
|
|
arg.iov[0].iov_len);
|
|
}
|
|
#endif
|
|
arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr,
|
|
skb->nh.iph->saddr, /* XXX */
|
|
arg.iov[0].iov_len, IPPROTO_TCP, 0);
|
|
arg.csumoffset = offsetof(struct tcphdr, check) / 2;
|
|
|
|
ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len);
|
|
|
|
TCP_INC_STATS_BH(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(tcptw, skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
|
|
tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
|
|
tcptw->tw_ts_recent);
|
|
|
|
inet_twsk_put(tw);
|
|
}
|
|
|
|
static void tcp_v4_reqsk_send_ack(struct sk_buff *skb,
|
|
struct request_sock *req)
|
|
{
|
|
tcp_v4_send_ack(NULL, skb, tcp_rsk(req)->snt_isn + 1,
|
|
tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
|
|
req->ts_recent);
|
|
}
|
|
|
|
/*
|
|
* Send a SYN-ACK after having received an ACK.
|
|
* This still operates on a request_sock only, not on a big
|
|
* socket.
|
|
*/
|
|
static int tcp_v4_send_synack(struct sock *sk, struct request_sock *req,
|
|
struct dst_entry *dst)
|
|
{
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
int err = -1;
|
|
struct sk_buff * skb;
|
|
|
|
/* First, grab a route. */
|
|
if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
|
|
goto out;
|
|
|
|
skb = tcp_make_synack(sk, dst, req);
|
|
|
|
if (skb) {
|
|
struct tcphdr *th = skb->h.th;
|
|
|
|
th->check = tcp_v4_check(skb->len,
|
|
ireq->loc_addr,
|
|
ireq->rmt_addr,
|
|
csum_partial((char *)th, skb->len,
|
|
skb->csum));
|
|
|
|
err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
|
|
ireq->rmt_addr,
|
|
ireq->opt);
|
|
err = net_xmit_eval(err);
|
|
}
|
|
|
|
out:
|
|
dst_release(dst);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* IPv4 request_sock destructor.
|
|
*/
|
|
static void tcp_v4_reqsk_destructor(struct request_sock *req)
|
|
{
|
|
kfree(inet_rsk(req)->opt);
|
|
}
|
|
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
static void syn_flood_warning(struct sk_buff *skb)
|
|
{
|
|
static unsigned long warntime;
|
|
|
|
if (time_after(jiffies, (warntime + HZ * 60))) {
|
|
warntime = jiffies;
|
|
printk(KERN_INFO
|
|
"possible SYN flooding on port %d. Sending cookies.\n",
|
|
ntohs(skb->h.th->dest));
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Save and compile IPv4 options into the request_sock if needed.
|
|
*/
|
|
static struct ip_options *tcp_v4_save_options(struct sock *sk,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct ip_options *opt = &(IPCB(skb)->opt);
|
|
struct ip_options *dopt = NULL;
|
|
|
|
if (opt && opt->optlen) {
|
|
int opt_size = optlength(opt);
|
|
dopt = kmalloc(opt_size, GFP_ATOMIC);
|
|
if (dopt) {
|
|
if (ip_options_echo(dopt, skb)) {
|
|
kfree(dopt);
|
|
dopt = NULL;
|
|
}
|
|
}
|
|
}
|
|
return dopt;
|
|
}
|
|
|
|
#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. */
|
|
static struct tcp_md5sig_key *
|
|
tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int i;
|
|
|
|
if (!tp->md5sig_info || !tp->md5sig_info->entries4)
|
|
return NULL;
|
|
for (i = 0; i < tp->md5sig_info->entries4; i++) {
|
|
if (tp->md5sig_info->keys4[i].addr == addr)
|
|
return (struct tcp_md5sig_key *)
|
|
&tp->md5sig_info->keys4[i];
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
|
|
struct sock *addr_sk)
|
|
{
|
|
return tcp_v4_md5_do_lookup(sk, inet_sk(addr_sk)->daddr);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_v4_md5_lookup);
|
|
|
|
static struct tcp_md5sig_key *tcp_v4_reqsk_md5_lookup(struct sock *sk,
|
|
struct request_sock *req)
|
|
{
|
|
return tcp_v4_md5_do_lookup(sk, inet_rsk(req)->rmt_addr);
|
|
}
|
|
|
|
/* This can be called on a newly created socket, from other files */
|
|
int tcp_v4_md5_do_add(struct sock *sk, __be32 addr,
|
|
u8 *newkey, u8 newkeylen)
|
|
{
|
|
/* Add Key to the list */
|
|
struct tcp4_md5sig_key *key;
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct tcp4_md5sig_key *keys;
|
|
|
|
key = (struct tcp4_md5sig_key *)tcp_v4_md5_do_lookup(sk, addr);
|
|
if (key) {
|
|
/* Pre-existing entry - just update that one. */
|
|
kfree(key->key);
|
|
key->key = newkey;
|
|
key->keylen = newkeylen;
|
|
} else {
|
|
struct tcp_md5sig_info *md5sig;
|
|
|
|
if (!tp->md5sig_info) {
|
|
tp->md5sig_info = kzalloc(sizeof(*tp->md5sig_info),
|
|
GFP_ATOMIC);
|
|
if (!tp->md5sig_info) {
|
|
kfree(newkey);
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
if (tcp_alloc_md5sig_pool() == NULL) {
|
|
kfree(newkey);
|
|
return -ENOMEM;
|
|
}
|
|
md5sig = tp->md5sig_info;
|
|
|
|
if (md5sig->alloced4 == md5sig->entries4) {
|
|
keys = kmalloc((sizeof(*keys) *
|
|
(md5sig->entries4 + 1)), GFP_ATOMIC);
|
|
if (!keys) {
|
|
kfree(newkey);
|
|
tcp_free_md5sig_pool();
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (md5sig->entries4)
|
|
memcpy(keys, md5sig->keys4,
|
|
sizeof(*keys) * md5sig->entries4);
|
|
|
|
/* Free old key list, and reference new one */
|
|
if (md5sig->keys4)
|
|
kfree(md5sig->keys4);
|
|
md5sig->keys4 = keys;
|
|
md5sig->alloced4++;
|
|
}
|
|
md5sig->entries4++;
|
|
md5sig->keys4[md5sig->entries4 - 1].addr = addr;
|
|
md5sig->keys4[md5sig->entries4 - 1].key = newkey;
|
|
md5sig->keys4[md5sig->entries4 - 1].keylen = newkeylen;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_v4_md5_do_add);
|
|
|
|
static int tcp_v4_md5_add_func(struct sock *sk, struct sock *addr_sk,
|
|
u8 *newkey, u8 newkeylen)
|
|
{
|
|
return tcp_v4_md5_do_add(sk, inet_sk(addr_sk)->daddr,
|
|
newkey, newkeylen);
|
|
}
|
|
|
|
int tcp_v4_md5_do_del(struct sock *sk, __be32 addr)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
int i;
|
|
|
|
for (i = 0; i < tp->md5sig_info->entries4; i++) {
|
|
if (tp->md5sig_info->keys4[i].addr == addr) {
|
|
/* Free the key */
|
|
kfree(tp->md5sig_info->keys4[i].key);
|
|
tp->md5sig_info->entries4--;
|
|
|
|
if (tp->md5sig_info->entries4 == 0) {
|
|
kfree(tp->md5sig_info->keys4);
|
|
tp->md5sig_info->keys4 = NULL;
|
|
tp->md5sig_info->alloced4 = 0;
|
|
} else if (tp->md5sig_info->entries4 != i) {
|
|
/* Need to do some manipulation */
|
|
memcpy(&tp->md5sig_info->keys4[i],
|
|
&tp->md5sig_info->keys4[i+1],
|
|
(tp->md5sig_info->entries4 - i) *
|
|
sizeof(struct tcp4_md5sig_key));
|
|
}
|
|
tcp_free_md5sig_pool();
|
|
return 0;
|
|
}
|
|
}
|
|
return -ENOENT;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_v4_md5_do_del);
|
|
|
|
static void tcp_v4_clear_md5_list(struct sock *sk)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
/* Free each key, then the set of key keys,
|
|
* the crypto element, and then decrement our
|
|
* hold on the last resort crypto.
|
|
*/
|
|
if (tp->md5sig_info->entries4) {
|
|
int i;
|
|
for (i = 0; i < tp->md5sig_info->entries4; i++)
|
|
kfree(tp->md5sig_info->keys4[i].key);
|
|
tp->md5sig_info->entries4 = 0;
|
|
tcp_free_md5sig_pool();
|
|
}
|
|
if (tp->md5sig_info->keys4) {
|
|
kfree(tp->md5sig_info->keys4);
|
|
tp->md5sig_info->keys4 = NULL;
|
|
tp->md5sig_info->alloced4 = 0;
|
|
}
|
|
}
|
|
|
|
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;
|
|
u8 *newkey;
|
|
|
|
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_key || !cmd.tcpm_keylen) {
|
|
if (!tcp_sk(sk)->md5sig_info)
|
|
return -ENOENT;
|
|
return tcp_v4_md5_do_del(sk, sin->sin_addr.s_addr);
|
|
}
|
|
|
|
if (cmd.tcpm_keylen > TCP_MD5SIG_MAXKEYLEN)
|
|
return -EINVAL;
|
|
|
|
if (!tcp_sk(sk)->md5sig_info) {
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct tcp_md5sig_info *p = kzalloc(sizeof(*p), GFP_KERNEL);
|
|
|
|
if (!p)
|
|
return -EINVAL;
|
|
|
|
tp->md5sig_info = p;
|
|
|
|
}
|
|
|
|
newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, GFP_KERNEL);
|
|
if (!newkey)
|
|
return -ENOMEM;
|
|
return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
|
|
newkey, cmd.tcpm_keylen);
|
|
}
|
|
|
|
static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
|
|
__be32 saddr, __be32 daddr,
|
|
struct tcphdr *th, int protocol,
|
|
int tcplen)
|
|
{
|
|
struct scatterlist sg[4];
|
|
__u16 data_len;
|
|
int block = 0;
|
|
__sum16 old_checksum;
|
|
struct tcp_md5sig_pool *hp;
|
|
struct tcp4_pseudohdr *bp;
|
|
struct hash_desc *desc;
|
|
int err;
|
|
unsigned int nbytes = 0;
|
|
|
|
/*
|
|
* Okay, so RFC2385 is turned on for this connection,
|
|
* so we need to generate the MD5 hash for the packet now.
|
|
*/
|
|
|
|
hp = tcp_get_md5sig_pool();
|
|
if (!hp)
|
|
goto clear_hash_noput;
|
|
|
|
bp = &hp->md5_blk.ip4;
|
|
desc = &hp->md5_desc;
|
|
|
|
/*
|
|
* 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 = protocol;
|
|
bp->len = htons(tcplen);
|
|
sg_set_buf(&sg[block++], bp, sizeof(*bp));
|
|
nbytes += sizeof(*bp);
|
|
|
|
/* 2. the TCP header, excluding options, and assuming a
|
|
* checksum of zero/
|
|
*/
|
|
old_checksum = th->check;
|
|
th->check = 0;
|
|
sg_set_buf(&sg[block++], th, sizeof(struct tcphdr));
|
|
nbytes += sizeof(struct tcphdr);
|
|
|
|
/* 3. the TCP segment data (if any) */
|
|
data_len = tcplen - (th->doff << 2);
|
|
if (data_len > 0) {
|
|
unsigned char *data = (unsigned char *)th + (th->doff << 2);
|
|
sg_set_buf(&sg[block++], data, data_len);
|
|
nbytes += data_len;
|
|
}
|
|
|
|
/* 4. an independently-specified key or password, known to both
|
|
* TCPs and presumably connection-specific
|
|
*/
|
|
sg_set_buf(&sg[block++], key->key, key->keylen);
|
|
nbytes += key->keylen;
|
|
|
|
/* Now store the Hash into the packet */
|
|
err = crypto_hash_init(desc);
|
|
if (err)
|
|
goto clear_hash;
|
|
err = crypto_hash_update(desc, sg, nbytes);
|
|
if (err)
|
|
goto clear_hash;
|
|
err = crypto_hash_final(desc, md5_hash);
|
|
if (err)
|
|
goto clear_hash;
|
|
|
|
/* Reset header, and free up the crypto */
|
|
tcp_put_md5sig_pool();
|
|
th->check = old_checksum;
|
|
|
|
out:
|
|
return 0;
|
|
clear_hash:
|
|
tcp_put_md5sig_pool();
|
|
clear_hash_noput:
|
|
memset(md5_hash, 0, 16);
|
|
goto out;
|
|
}
|
|
|
|
int tcp_v4_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key,
|
|
struct sock *sk,
|
|
struct dst_entry *dst,
|
|
struct request_sock *req,
|
|
struct tcphdr *th, int protocol,
|
|
int tcplen)
|
|
{
|
|
__be32 saddr, daddr;
|
|
|
|
if (sk) {
|
|
saddr = inet_sk(sk)->saddr;
|
|
daddr = inet_sk(sk)->daddr;
|
|
} else {
|
|
struct rtable *rt = (struct rtable *)dst;
|
|
BUG_ON(!rt);
|
|
saddr = rt->rt_src;
|
|
daddr = rt->rt_dst;
|
|
}
|
|
return tcp_v4_do_calc_md5_hash(md5_hash, key,
|
|
saddr, daddr,
|
|
th, protocol, tcplen);
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_v4_calc_md5_hash);
|
|
|
|
static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
/*
|
|
* 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.
|
|
*/
|
|
__u8 *hash_location = NULL;
|
|
struct tcp_md5sig_key *hash_expected;
|
|
struct iphdr *iph = skb->nh.iph;
|
|
struct tcphdr *th = skb->h.th;
|
|
int length = (th->doff << 2) - sizeof(struct tcphdr);
|
|
int genhash;
|
|
unsigned char *ptr;
|
|
unsigned char newhash[16];
|
|
|
|
hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
|
|
|
|
/*
|
|
* If the TCP option length is less than the TCP_MD5SIG
|
|
* option length, then we can shortcut
|
|
*/
|
|
if (length < TCPOLEN_MD5SIG) {
|
|
if (hash_expected)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
/* Okay, we can't shortcut - we have to grub through the options */
|
|
ptr = (unsigned char *)(th + 1);
|
|
while (length > 0) {
|
|
int opcode = *ptr++;
|
|
int opsize;
|
|
|
|
switch (opcode) {
|
|
case TCPOPT_EOL:
|
|
goto done_opts;
|
|
case TCPOPT_NOP:
|
|
length--;
|
|
continue;
|
|
default:
|
|
opsize = *ptr++;
|
|
if (opsize < 2)
|
|
goto done_opts;
|
|
if (opsize > length)
|
|
goto done_opts;
|
|
|
|
if (opcode == TCPOPT_MD5SIG) {
|
|
hash_location = ptr;
|
|
goto done_opts;
|
|
}
|
|
}
|
|
ptr += opsize-2;
|
|
length -= opsize;
|
|
}
|
|
done_opts:
|
|
/* We've parsed the options - do we have a hash? */
|
|
if (!hash_expected && !hash_location)
|
|
return 0;
|
|
|
|
if (hash_expected && !hash_location) {
|
|
LIMIT_NETDEBUG(KERN_INFO "MD5 Hash expected but NOT found "
|
|
"(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)\n",
|
|
NIPQUAD(iph->saddr), ntohs(th->source),
|
|
NIPQUAD(iph->daddr), ntohs(th->dest));
|
|
return 1;
|
|
}
|
|
|
|
if (!hash_expected && hash_location) {
|
|
LIMIT_NETDEBUG(KERN_INFO "MD5 Hash NOT expected but found "
|
|
"(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)\n",
|
|
NIPQUAD(iph->saddr), ntohs(th->source),
|
|
NIPQUAD(iph->daddr), ntohs(th->dest));
|
|
return 1;
|
|
}
|
|
|
|
/* Okay, so this is hash_expected and hash_location -
|
|
* so we need to calculate the checksum.
|
|
*/
|
|
genhash = tcp_v4_do_calc_md5_hash(newhash,
|
|
hash_expected,
|
|
iph->saddr, iph->daddr,
|
|
th, sk->sk_protocol,
|
|
skb->len);
|
|
|
|
if (genhash || memcmp(hash_location, newhash, 16) != 0) {
|
|
if (net_ratelimit()) {
|
|
printk(KERN_INFO "MD5 Hash failed for "
|
|
"(" NIPQUAD_FMT ", %d)->(" NIPQUAD_FMT ", %d)%s\n",
|
|
NIPQUAD(iph->saddr), ntohs(th->source),
|
|
NIPQUAD(iph->daddr), ntohs(th->dest),
|
|
genhash ? " tcp_v4_calc_md5_hash failed" : "");
|
|
}
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#endif
|
|
|
|
struct request_sock_ops tcp_request_sock_ops __read_mostly = {
|
|
.family = PF_INET,
|
|
.obj_size = sizeof(struct tcp_request_sock),
|
|
.rtx_syn_ack = tcp_v4_send_synack,
|
|
.send_ack = tcp_v4_reqsk_send_ack,
|
|
.destructor = tcp_v4_reqsk_destructor,
|
|
.send_reset = tcp_v4_send_reset,
|
|
};
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
static struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
|
|
.md5_lookup = tcp_v4_reqsk_md5_lookup,
|
|
};
|
|
#endif
|
|
|
|
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,
|
|
};
|
|
|
|
int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct inet_request_sock *ireq;
|
|
struct tcp_options_received tmp_opt;
|
|
struct request_sock *req;
|
|
__be32 saddr = skb->nh.iph->saddr;
|
|
__be32 daddr = skb->nh.iph->daddr;
|
|
__u32 isn = TCP_SKB_CB(skb)->when;
|
|
struct dst_entry *dst = NULL;
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
int want_cookie = 0;
|
|
#else
|
|
#define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */
|
|
#endif
|
|
|
|
/* Never answer to SYNs send to broadcast or multicast */
|
|
if (((struct rtable *)skb->dst)->rt_flags &
|
|
(RTCF_BROADCAST | RTCF_MULTICAST))
|
|
goto drop;
|
|
|
|
/* TW buckets are converted to open requests without
|
|
* limitations, they conserve resources and peer is
|
|
* evidently real one.
|
|
*/
|
|
if (inet_csk_reqsk_queue_is_full(sk) && !isn) {
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
if (sysctl_tcp_syncookies) {
|
|
want_cookie = 1;
|
|
} else
|
|
#endif
|
|
goto drop;
|
|
}
|
|
|
|
/* Accept backlog is full. If we have already queued enough
|
|
* of warm entries in syn queue, drop request. It is better than
|
|
* clogging syn queue with openreqs with exponentially increasing
|
|
* timeout.
|
|
*/
|
|
if (sk_acceptq_is_full(sk) && inet_csk_reqsk_queue_young(sk) > 1)
|
|
goto drop;
|
|
|
|
req = reqsk_alloc(&tcp_request_sock_ops);
|
|
if (!req)
|
|
goto drop;
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
tcp_rsk(req)->af_specific = &tcp_request_sock_ipv4_ops;
|
|
#endif
|
|
|
|
tcp_clear_options(&tmp_opt);
|
|
tmp_opt.mss_clamp = 536;
|
|
tmp_opt.user_mss = tcp_sk(sk)->rx_opt.user_mss;
|
|
|
|
tcp_parse_options(skb, &tmp_opt, 0);
|
|
|
|
if (want_cookie) {
|
|
tcp_clear_options(&tmp_opt);
|
|
tmp_opt.saw_tstamp = 0;
|
|
}
|
|
|
|
if (tmp_opt.saw_tstamp && !tmp_opt.rcv_tsval) {
|
|
/* Some OSes (unknown ones, but I see them on web server, which
|
|
* contains information interesting only for windows'
|
|
* users) do not send their stamp in SYN. It is easy case.
|
|
* We simply do not advertise TS support.
|
|
*/
|
|
tmp_opt.saw_tstamp = 0;
|
|
tmp_opt.tstamp_ok = 0;
|
|
}
|
|
tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
|
|
|
|
tcp_openreq_init(req, &tmp_opt, skb);
|
|
|
|
if (security_inet_conn_request(sk, skb, req))
|
|
goto drop_and_free;
|
|
|
|
ireq = inet_rsk(req);
|
|
ireq->loc_addr = daddr;
|
|
ireq->rmt_addr = saddr;
|
|
ireq->opt = tcp_v4_save_options(sk, skb);
|
|
if (!want_cookie)
|
|
TCP_ECN_create_request(req, skb->h.th);
|
|
|
|
if (want_cookie) {
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
syn_flood_warning(skb);
|
|
#endif
|
|
isn = cookie_v4_init_sequence(sk, skb, &req->mss);
|
|
} else if (!isn) {
|
|
struct inet_peer *peer = NULL;
|
|
|
|
/* VJ's idea. We save last timestamp seen
|
|
* from the destination in peer table, when entering
|
|
* state TIME-WAIT, and check against it before
|
|
* accepting new connection request.
|
|
*
|
|
* If "isn" is not zero, this request hit alive
|
|
* timewait bucket, so that all the necessary checks
|
|
* are made in the function processing timewait state.
|
|
*/
|
|
if (tmp_opt.saw_tstamp &&
|
|
tcp_death_row.sysctl_tw_recycle &&
|
|
(dst = inet_csk_route_req(sk, req)) != NULL &&
|
|
(peer = rt_get_peer((struct rtable *)dst)) != NULL &&
|
|
peer->v4daddr == saddr) {
|
|
if (xtime.tv_sec < peer->tcp_ts_stamp + TCP_PAWS_MSL &&
|
|
(s32)(peer->tcp_ts - req->ts_recent) >
|
|
TCP_PAWS_WINDOW) {
|
|
NET_INC_STATS_BH(LINUX_MIB_PAWSPASSIVEREJECTED);
|
|
dst_release(dst);
|
|
goto drop_and_free;
|
|
}
|
|
}
|
|
/* Kill the following clause, if you dislike this way. */
|
|
else if (!sysctl_tcp_syncookies &&
|
|
(sysctl_max_syn_backlog - inet_csk_reqsk_queue_len(sk) <
|
|
(sysctl_max_syn_backlog >> 2)) &&
|
|
(!peer || !peer->tcp_ts_stamp) &&
|
|
(!dst || !dst_metric(dst, RTAX_RTT))) {
|
|
/* Without syncookies last quarter of
|
|
* backlog is filled with destinations,
|
|
* proven to be alive.
|
|
* It means that we continue to communicate
|
|
* to destinations, already remembered
|
|
* to the moment of synflood.
|
|
*/
|
|
LIMIT_NETDEBUG(KERN_DEBUG "TCP: drop open "
|
|
"request from %u.%u.%u.%u/%u\n",
|
|
NIPQUAD(saddr),
|
|
ntohs(skb->h.th->source));
|
|
dst_release(dst);
|
|
goto drop_and_free;
|
|
}
|
|
|
|
isn = tcp_v4_init_sequence(skb);
|
|
}
|
|
tcp_rsk(req)->snt_isn = isn;
|
|
|
|
if (tcp_v4_send_synack(sk, req, dst))
|
|
goto drop_and_free;
|
|
|
|
if (want_cookie) {
|
|
reqsk_free(req);
|
|
} else {
|
|
inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
|
|
}
|
|
return 0;
|
|
|
|
drop_and_free:
|
|
reqsk_free(req);
|
|
drop:
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* The three way handshake has completed - we got a valid synack -
|
|
* now create the new socket.
|
|
*/
|
|
struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
|
|
struct request_sock *req,
|
|
struct dst_entry *dst)
|
|
{
|
|
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
|
|
|
|
if (sk_acceptq_is_full(sk))
|
|
goto exit_overflow;
|
|
|
|
if (!dst && (dst = inet_csk_route_req(sk, req)) == NULL)
|
|
goto exit;
|
|
|
|
newsk = tcp_create_openreq_child(sk, req, skb);
|
|
if (!newsk)
|
|
goto exit;
|
|
|
|
newsk->sk_gso_type = SKB_GSO_TCPV4;
|
|
sk_setup_caps(newsk, dst);
|
|
|
|
newtp = tcp_sk(newsk);
|
|
newinet = inet_sk(newsk);
|
|
ireq = inet_rsk(req);
|
|
newinet->daddr = ireq->rmt_addr;
|
|
newinet->rcv_saddr = ireq->loc_addr;
|
|
newinet->saddr = ireq->loc_addr;
|
|
newinet->opt = ireq->opt;
|
|
ireq->opt = NULL;
|
|
newinet->mc_index = inet_iif(skb);
|
|
newinet->mc_ttl = skb->nh.iph->ttl;
|
|
inet_csk(newsk)->icsk_ext_hdr_len = 0;
|
|
if (newinet->opt)
|
|
inet_csk(newsk)->icsk_ext_hdr_len = newinet->opt->optlen;
|
|
newinet->id = newtp->write_seq ^ jiffies;
|
|
|
|
tcp_mtup_init(newsk);
|
|
tcp_sync_mss(newsk, dst_mtu(dst));
|
|
newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
|
|
tcp_initialize_rcv_mss(newsk);
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
/* Copy over the MD5 key from the original socket */
|
|
if ((key = tcp_v4_md5_do_lookup(sk, newinet->daddr)) != NULL) {
|
|
/*
|
|
* 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.
|
|
*/
|
|
char *newkey = kmemdup(key->key, key->keylen, GFP_ATOMIC);
|
|
if (newkey != NULL)
|
|
tcp_v4_md5_do_add(newsk, inet_sk(sk)->daddr,
|
|
newkey, key->keylen);
|
|
}
|
|
#endif
|
|
|
|
__inet_hash(&tcp_hashinfo, newsk, 0);
|
|
__inet_inherit_port(&tcp_hashinfo, sk, newsk);
|
|
|
|
return newsk;
|
|
|
|
exit_overflow:
|
|
NET_INC_STATS_BH(LINUX_MIB_LISTENOVERFLOWS);
|
|
exit:
|
|
NET_INC_STATS_BH(LINUX_MIB_LISTENDROPS);
|
|
dst_release(dst);
|
|
return NULL;
|
|
}
|
|
|
|
static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct tcphdr *th = skb->h.th;
|
|
struct iphdr *iph = skb->nh.iph;
|
|
struct sock *nsk;
|
|
struct request_sock **prev;
|
|
/* Find possible connection requests. */
|
|
struct request_sock *req = inet_csk_search_req(sk, &prev, th->source,
|
|
iph->saddr, iph->daddr);
|
|
if (req)
|
|
return tcp_check_req(sk, skb, req, prev);
|
|
|
|
nsk = inet_lookup_established(&tcp_hashinfo, skb->nh.iph->saddr,
|
|
th->source, skb->nh.iph->daddr,
|
|
th->dest, inet_iif(skb));
|
|
|
|
if (nsk) {
|
|
if (nsk->sk_state != TCP_TIME_WAIT) {
|
|
bh_lock_sock(nsk);
|
|
return nsk;
|
|
}
|
|
inet_twsk_put(inet_twsk(nsk));
|
|
return NULL;
|
|
}
|
|
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
if (!th->rst && !th->syn && th->ack)
|
|
sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
|
|
#endif
|
|
return sk;
|
|
}
|
|
|
|
static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
|
|
{
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE) {
|
|
if (!tcp_v4_check(skb->len, skb->nh.iph->saddr,
|
|
skb->nh.iph->daddr, skb->csum)) {
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
skb->csum = csum_tcpudp_nofold(skb->nh.iph->saddr, skb->nh.iph->daddr,
|
|
skb->len, IPPROTO_TCP, 0);
|
|
|
|
if (skb->len <= 76) {
|
|
return __skb_checksum_complete(skb);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* The socket must have it's spinlock held when we get
|
|
* here.
|
|
*
|
|
* 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;
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
/*
|
|
* We really want to reject the packet as early as possible
|
|
* if:
|
|
* o We're expecting an MD5'd packet and this is no MD5 tcp option
|
|
* o There is an MD5 option and we're not expecting one
|
|
*/
|
|
if (tcp_v4_inbound_md5_hash(sk, skb))
|
|
goto discard;
|
|
#endif
|
|
|
|
if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
|
|
TCP_CHECK_TIMER(sk);
|
|
if (tcp_rcv_established(sk, skb, skb->h.th, skb->len)) {
|
|
rsk = sk;
|
|
goto reset;
|
|
}
|
|
TCP_CHECK_TIMER(sk);
|
|
return 0;
|
|
}
|
|
|
|
if (skb->len < (skb->h.th->doff << 2) || tcp_checksum_complete(skb))
|
|
goto csum_err;
|
|
|
|
if (sk->sk_state == TCP_LISTEN) {
|
|
struct sock *nsk = tcp_v4_hnd_req(sk, skb);
|
|
if (!nsk)
|
|
goto discard;
|
|
|
|
if (nsk != sk) {
|
|
if (tcp_child_process(sk, nsk, skb)) {
|
|
rsk = nsk;
|
|
goto reset;
|
|
}
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
TCP_CHECK_TIMER(sk);
|
|
if (tcp_rcv_state_process(sk, skb, skb->h.th, skb->len)) {
|
|
rsk = sk;
|
|
goto reset;
|
|
}
|
|
TCP_CHECK_TIMER(sk);
|
|
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(TCP_MIB_INERRS);
|
|
goto discard;
|
|
}
|
|
|
|
/*
|
|
* From tcp_input.c
|
|
*/
|
|
|
|
int tcp_v4_rcv(struct sk_buff *skb)
|
|
{
|
|
struct tcphdr *th;
|
|
struct sock *sk;
|
|
int ret;
|
|
|
|
if (skb->pkt_type != PACKET_HOST)
|
|
goto discard_it;
|
|
|
|
/* Count it even if it's bad */
|
|
TCP_INC_STATS_BH(TCP_MIB_INSEGS);
|
|
|
|
if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
|
|
goto discard_it;
|
|
|
|
th = skb->h.th;
|
|
|
|
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->ip_summed != CHECKSUM_UNNECESSARY &&
|
|
tcp_v4_checksum_init(skb)))
|
|
goto bad_packet;
|
|
|
|
th = skb->h.th;
|
|
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)->when = 0;
|
|
TCP_SKB_CB(skb)->flags = skb->nh.iph->tos;
|
|
TCP_SKB_CB(skb)->sacked = 0;
|
|
|
|
sk = __inet_lookup(&tcp_hashinfo, skb->nh.iph->saddr, th->source,
|
|
skb->nh.iph->daddr, th->dest,
|
|
inet_iif(skb));
|
|
|
|
if (!sk)
|
|
goto no_tcp_socket;
|
|
|
|
process:
|
|
if (sk->sk_state == TCP_TIME_WAIT)
|
|
goto do_time_wait;
|
|
|
|
if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
|
|
goto discard_and_relse;
|
|
nf_reset(skb);
|
|
|
|
if (sk_filter(sk, skb))
|
|
goto discard_and_relse;
|
|
|
|
skb->dev = NULL;
|
|
|
|
bh_lock_sock_nested(sk);
|
|
ret = 0;
|
|
if (!sock_owned_by_user(sk)) {
|
|
#ifdef CONFIG_NET_DMA
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
if (!tp->ucopy.dma_chan && tp->ucopy.pinned_list)
|
|
tp->ucopy.dma_chan = get_softnet_dma();
|
|
if (tp->ucopy.dma_chan)
|
|
ret = tcp_v4_do_rcv(sk, skb);
|
|
else
|
|
#endif
|
|
{
|
|
if (!tcp_prequeue(sk, skb))
|
|
ret = tcp_v4_do_rcv(sk, skb);
|
|
}
|
|
} else
|
|
sk_add_backlog(sk, skb);
|
|
bh_unlock_sock(sk);
|
|
|
|
sock_put(sk);
|
|
|
|
return ret;
|
|
|
|
no_tcp_socket:
|
|
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
|
|
goto discard_it;
|
|
|
|
if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
|
|
bad_packet:
|
|
TCP_INC_STATS_BH(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 (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
|
|
TCP_INC_STATS_BH(TCP_MIB_INERRS);
|
|
inet_twsk_put(inet_twsk(sk));
|
|
goto discard_it;
|
|
}
|
|
switch (tcp_timewait_state_process(inet_twsk(sk), skb, th)) {
|
|
case TCP_TW_SYN: {
|
|
struct sock *sk2 = inet_lookup_listener(&tcp_hashinfo,
|
|
skb->nh.iph->daddr,
|
|
th->dest,
|
|
inet_iif(skb));
|
|
if (sk2) {
|
|
inet_twsk_deschedule(inet_twsk(sk), &tcp_death_row);
|
|
inet_twsk_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;
|
|
}
|
|
|
|
/* VJ's idea. Save last timestamp seen from this destination
|
|
* and hold it at least for normal timewait interval to use for duplicate
|
|
* segment detection in subsequent connections, before they enter synchronized
|
|
* state.
|
|
*/
|
|
|
|
int tcp_v4_remember_stamp(struct sock *sk)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct rtable *rt = (struct rtable *)__sk_dst_get(sk);
|
|
struct inet_peer *peer = NULL;
|
|
int release_it = 0;
|
|
|
|
if (!rt || rt->rt_dst != inet->daddr) {
|
|
peer = inet_getpeer(inet->daddr, 1);
|
|
release_it = 1;
|
|
} else {
|
|
if (!rt->peer)
|
|
rt_bind_peer(rt, 1);
|
|
peer = rt->peer;
|
|
}
|
|
|
|
if (peer) {
|
|
if ((s32)(peer->tcp_ts - tp->rx_opt.ts_recent) <= 0 ||
|
|
(peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec &&
|
|
peer->tcp_ts_stamp <= tp->rx_opt.ts_recent_stamp)) {
|
|
peer->tcp_ts_stamp = tp->rx_opt.ts_recent_stamp;
|
|
peer->tcp_ts = tp->rx_opt.ts_recent;
|
|
}
|
|
if (release_it)
|
|
inet_putpeer(peer);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw)
|
|
{
|
|
struct inet_peer *peer = inet_getpeer(tw->tw_daddr, 1);
|
|
|
|
if (peer) {
|
|
const struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
|
|
|
|
if ((s32)(peer->tcp_ts - tcptw->tw_ts_recent) <= 0 ||
|
|
(peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec &&
|
|
peer->tcp_ts_stamp <= tcptw->tw_ts_recent_stamp)) {
|
|
peer->tcp_ts_stamp = tcptw->tw_ts_recent_stamp;
|
|
peer->tcp_ts = tcptw->tw_ts_recent;
|
|
}
|
|
inet_putpeer(peer);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
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,
|
|
.conn_request = tcp_v4_conn_request,
|
|
.syn_recv_sock = tcp_v4_syn_recv_sock,
|
|
.remember_stamp = tcp_v4_remember_stamp,
|
|
.net_header_len = sizeof(struct iphdr),
|
|
.setsockopt = ip_setsockopt,
|
|
.getsockopt = ip_getsockopt,
|
|
.addr2sockaddr = inet_csk_addr2sockaddr,
|
|
.sockaddr_len = sizeof(struct sockaddr_in),
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_setsockopt = compat_ip_setsockopt,
|
|
.compat_getsockopt = compat_ip_getsockopt,
|
|
#endif
|
|
};
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
static struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
|
|
.md5_lookup = tcp_v4_md5_lookup,
|
|
.calc_md5_hash = tcp_v4_calc_md5_hash,
|
|
.md5_add = tcp_v4_md5_add_func,
|
|
.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);
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
skb_queue_head_init(&tp->out_of_order_queue);
|
|
tcp_init_xmit_timers(sk);
|
|
tcp_prequeue_init(tp);
|
|
|
|
icsk->icsk_rto = TCP_TIMEOUT_INIT;
|
|
tp->mdev = TCP_TIMEOUT_INIT;
|
|
|
|
/* So many TCP implementations out there (incorrectly) count the
|
|
* initial SYN frame in their delayed-ACK and congestion control
|
|
* algorithms that we must have the following bandaid to talk
|
|
* efficiently to them. -DaveM
|
|
*/
|
|
tp->snd_cwnd = 2;
|
|
|
|
/* See draft-stevens-tcpca-spec-01 for discussion of the
|
|
* initialization of these values.
|
|
*/
|
|
tp->snd_ssthresh = 0x7fffffff; /* Infinity */
|
|
tp->snd_cwnd_clamp = ~0;
|
|
tp->mss_cache = 536;
|
|
|
|
tp->reordering = sysctl_tcp_reordering;
|
|
icsk->icsk_ca_ops = &tcp_init_congestion_ops;
|
|
|
|
sk->sk_state = TCP_CLOSE;
|
|
|
|
sk->sk_write_space = sk_stream_write_space;
|
|
sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
|
|
|
|
icsk->icsk_af_ops = &ipv4_specific;
|
|
icsk->icsk_sync_mss = tcp_sync_mss;
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
tp->af_specific = &tcp_sock_ipv4_specific;
|
|
#endif
|
|
|
|
sk->sk_sndbuf = sysctl_tcp_wmem[1];
|
|
sk->sk_rcvbuf = sysctl_tcp_rmem[1];
|
|
|
|
atomic_inc(&tcp_sockets_allocated);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int 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. */
|
|
sk_stream_writequeue_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_v4_clear_md5_list(sk);
|
|
kfree(tp->md5sig_info);
|
|
tp->md5sig_info = NULL;
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_NET_DMA
|
|
/* Cleans up our sk_async_wait_queue */
|
|
__skb_queue_purge(&sk->sk_async_wait_queue);
|
|
#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(&tcp_hashinfo, sk);
|
|
|
|
/*
|
|
* If sendmsg cached page exists, toss it.
|
|
*/
|
|
if (sk->sk_sndmsg_page) {
|
|
__free_page(sk->sk_sndmsg_page);
|
|
sk->sk_sndmsg_page = NULL;
|
|
}
|
|
|
|
atomic_dec(&tcp_sockets_allocated);
|
|
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(tcp_v4_destroy_sock);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
/* Proc filesystem TCP sock list dumping. */
|
|
|
|
static inline struct inet_timewait_sock *tw_head(struct hlist_head *head)
|
|
{
|
|
return hlist_empty(head) ? NULL :
|
|
list_entry(head->first, struct inet_timewait_sock, tw_node);
|
|
}
|
|
|
|
static inline struct inet_timewait_sock *tw_next(struct inet_timewait_sock *tw)
|
|
{
|
|
return tw->tw_node.next ?
|
|
hlist_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
|
|
}
|
|
|
|
static void *listening_get_next(struct seq_file *seq, void *cur)
|
|
{
|
|
struct inet_connection_sock *icsk;
|
|
struct hlist_node *node;
|
|
struct sock *sk = cur;
|
|
struct tcp_iter_state* st = seq->private;
|
|
|
|
if (!sk) {
|
|
st->bucket = 0;
|
|
sk = sk_head(&tcp_hashinfo.listening_hash[0]);
|
|
goto get_sk;
|
|
}
|
|
|
|
++st->num;
|
|
|
|
if (st->state == TCP_SEQ_STATE_OPENREQ) {
|
|
struct request_sock *req = cur;
|
|
|
|
icsk = inet_csk(st->syn_wait_sk);
|
|
req = req->dl_next;
|
|
while (1) {
|
|
while (req) {
|
|
if (req->rsk_ops->family == st->family) {
|
|
cur = req;
|
|
goto out;
|
|
}
|
|
req = req->dl_next;
|
|
}
|
|
if (++st->sbucket >= icsk->icsk_accept_queue.listen_opt->nr_table_entries)
|
|
break;
|
|
get_req:
|
|
req = icsk->icsk_accept_queue.listen_opt->syn_table[st->sbucket];
|
|
}
|
|
sk = sk_next(st->syn_wait_sk);
|
|
st->state = TCP_SEQ_STATE_LISTENING;
|
|
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
|
|
} else {
|
|
icsk = inet_csk(sk);
|
|
read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
|
|
if (reqsk_queue_len(&icsk->icsk_accept_queue))
|
|
goto start_req;
|
|
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
|
|
sk = sk_next(sk);
|
|
}
|
|
get_sk:
|
|
sk_for_each_from(sk, node) {
|
|
if (sk->sk_family == st->family) {
|
|
cur = sk;
|
|
goto out;
|
|
}
|
|
icsk = inet_csk(sk);
|
|
read_lock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
|
|
if (reqsk_queue_len(&icsk->icsk_accept_queue)) {
|
|
start_req:
|
|
st->uid = sock_i_uid(sk);
|
|
st->syn_wait_sk = sk;
|
|
st->state = TCP_SEQ_STATE_OPENREQ;
|
|
st->sbucket = 0;
|
|
goto get_req;
|
|
}
|
|
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
|
|
}
|
|
if (++st->bucket < INET_LHTABLE_SIZE) {
|
|
sk = sk_head(&tcp_hashinfo.listening_hash[st->bucket]);
|
|
goto get_sk;
|
|
}
|
|
cur = NULL;
|
|
out:
|
|
return cur;
|
|
}
|
|
|
|
static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
void *rc = listening_get_next(seq, NULL);
|
|
|
|
while (rc && *pos) {
|
|
rc = listening_get_next(seq, rc);
|
|
--*pos;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static void *established_get_first(struct seq_file *seq)
|
|
{
|
|
struct tcp_iter_state* st = seq->private;
|
|
void *rc = NULL;
|
|
|
|
for (st->bucket = 0; st->bucket < tcp_hashinfo.ehash_size; ++st->bucket) {
|
|
struct sock *sk;
|
|
struct hlist_node *node;
|
|
struct inet_timewait_sock *tw;
|
|
|
|
/* We can reschedule _before_ having picked the target: */
|
|
cond_resched_softirq();
|
|
|
|
read_lock(&tcp_hashinfo.ehash[st->bucket].lock);
|
|
sk_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
|
|
if (sk->sk_family != st->family) {
|
|
continue;
|
|
}
|
|
rc = sk;
|
|
goto out;
|
|
}
|
|
st->state = TCP_SEQ_STATE_TIME_WAIT;
|
|
inet_twsk_for_each(tw, node,
|
|
&tcp_hashinfo.ehash[st->bucket].twchain) {
|
|
if (tw->tw_family != st->family) {
|
|
continue;
|
|
}
|
|
rc = tw;
|
|
goto out;
|
|
}
|
|
read_unlock(&tcp_hashinfo.ehash[st->bucket].lock);
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
}
|
|
out:
|
|
return rc;
|
|
}
|
|
|
|
static void *established_get_next(struct seq_file *seq, void *cur)
|
|
{
|
|
struct sock *sk = cur;
|
|
struct inet_timewait_sock *tw;
|
|
struct hlist_node *node;
|
|
struct tcp_iter_state* st = seq->private;
|
|
|
|
++st->num;
|
|
|
|
if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
|
|
tw = cur;
|
|
tw = tw_next(tw);
|
|
get_tw:
|
|
while (tw && tw->tw_family != st->family) {
|
|
tw = tw_next(tw);
|
|
}
|
|
if (tw) {
|
|
cur = tw;
|
|
goto out;
|
|
}
|
|
read_unlock(&tcp_hashinfo.ehash[st->bucket].lock);
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
|
|
/* We can reschedule between buckets: */
|
|
cond_resched_softirq();
|
|
|
|
if (++st->bucket < tcp_hashinfo.ehash_size) {
|
|
read_lock(&tcp_hashinfo.ehash[st->bucket].lock);
|
|
sk = sk_head(&tcp_hashinfo.ehash[st->bucket].chain);
|
|
} else {
|
|
cur = NULL;
|
|
goto out;
|
|
}
|
|
} else
|
|
sk = sk_next(sk);
|
|
|
|
sk_for_each_from(sk, node) {
|
|
if (sk->sk_family == st->family)
|
|
goto found;
|
|
}
|
|
|
|
st->state = TCP_SEQ_STATE_TIME_WAIT;
|
|
tw = tw_head(&tcp_hashinfo.ehash[st->bucket].twchain);
|
|
goto get_tw;
|
|
found:
|
|
cur = sk;
|
|
out:
|
|
return cur;
|
|
}
|
|
|
|
static void *established_get_idx(struct seq_file *seq, loff_t pos)
|
|
{
|
|
void *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;
|
|
|
|
inet_listen_lock(&tcp_hashinfo);
|
|
st->state = TCP_SEQ_STATE_LISTENING;
|
|
rc = listening_get_idx(seq, &pos);
|
|
|
|
if (!rc) {
|
|
inet_listen_unlock(&tcp_hashinfo);
|
|
local_bh_disable();
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
rc = established_get_idx(seq, pos);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
struct tcp_iter_state* st = seq->private;
|
|
st->state = TCP_SEQ_STATE_LISTENING;
|
|
st->num = 0;
|
|
return *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
|
|
}
|
|
|
|
static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
void *rc = NULL;
|
|
struct tcp_iter_state* st;
|
|
|
|
if (v == SEQ_START_TOKEN) {
|
|
rc = tcp_get_idx(seq, 0);
|
|
goto out;
|
|
}
|
|
st = seq->private;
|
|
|
|
switch (st->state) {
|
|
case TCP_SEQ_STATE_OPENREQ:
|
|
case TCP_SEQ_STATE_LISTENING:
|
|
rc = listening_get_next(seq, v);
|
|
if (!rc) {
|
|
inet_listen_unlock(&tcp_hashinfo);
|
|
local_bh_disable();
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
rc = established_get_first(seq);
|
|
}
|
|
break;
|
|
case TCP_SEQ_STATE_ESTABLISHED:
|
|
case TCP_SEQ_STATE_TIME_WAIT:
|
|
rc = established_get_next(seq, v);
|
|
break;
|
|
}
|
|
out:
|
|
++*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_OPENREQ:
|
|
if (v) {
|
|
struct inet_connection_sock *icsk = inet_csk(st->syn_wait_sk);
|
|
read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock);
|
|
}
|
|
case TCP_SEQ_STATE_LISTENING:
|
|
if (v != SEQ_START_TOKEN)
|
|
inet_listen_unlock(&tcp_hashinfo);
|
|
break;
|
|
case TCP_SEQ_STATE_TIME_WAIT:
|
|
case TCP_SEQ_STATE_ESTABLISHED:
|
|
if (v)
|
|
read_unlock(&tcp_hashinfo.ehash[st->bucket].lock);
|
|
local_bh_enable();
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int tcp_seq_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
|
|
struct seq_file *seq;
|
|
struct tcp_iter_state *s;
|
|
int rc;
|
|
|
|
if (unlikely(afinfo == NULL))
|
|
return -EINVAL;
|
|
|
|
s = kzalloc(sizeof(*s), GFP_KERNEL);
|
|
if (!s)
|
|
return -ENOMEM;
|
|
s->family = afinfo->family;
|
|
s->seq_ops.start = tcp_seq_start;
|
|
s->seq_ops.next = tcp_seq_next;
|
|
s->seq_ops.show = afinfo->seq_show;
|
|
s->seq_ops.stop = tcp_seq_stop;
|
|
|
|
rc = seq_open(file, &s->seq_ops);
|
|
if (rc)
|
|
goto out_kfree;
|
|
seq = file->private_data;
|
|
seq->private = s;
|
|
out:
|
|
return rc;
|
|
out_kfree:
|
|
kfree(s);
|
|
goto out;
|
|
}
|
|
|
|
int tcp_proc_register(struct tcp_seq_afinfo *afinfo)
|
|
{
|
|
int rc = 0;
|
|
struct proc_dir_entry *p;
|
|
|
|
if (!afinfo)
|
|
return -EINVAL;
|
|
afinfo->seq_fops->owner = afinfo->owner;
|
|
afinfo->seq_fops->open = tcp_seq_open;
|
|
afinfo->seq_fops->read = seq_read;
|
|
afinfo->seq_fops->llseek = seq_lseek;
|
|
afinfo->seq_fops->release = seq_release_private;
|
|
|
|
p = proc_net_fops_create(afinfo->name, S_IRUGO, afinfo->seq_fops);
|
|
if (p)
|
|
p->data = afinfo;
|
|
else
|
|
rc = -ENOMEM;
|
|
return rc;
|
|
}
|
|
|
|
void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo)
|
|
{
|
|
if (!afinfo)
|
|
return;
|
|
proc_net_remove(afinfo->name);
|
|
memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
|
|
}
|
|
|
|
static void get_openreq4(struct sock *sk, struct request_sock *req,
|
|
char *tmpbuf, int i, int uid)
|
|
{
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
int ttd = req->expires - jiffies;
|
|
|
|
sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
|
|
" %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p",
|
|
i,
|
|
ireq->loc_addr,
|
|
ntohs(inet_sk(sk)->sport),
|
|
ireq->rmt_addr,
|
|
ntohs(ireq->rmt_port),
|
|
TCP_SYN_RECV,
|
|
0, 0, /* could print option size, but that is af dependent. */
|
|
1, /* timers active (only the expire timer) */
|
|
jiffies_to_clock_t(ttd),
|
|
req->retrans,
|
|
uid,
|
|
0, /* non standard timer */
|
|
0, /* open_requests have no inode */
|
|
atomic_read(&sk->sk_refcnt),
|
|
req);
|
|
}
|
|
|
|
static void get_tcp4_sock(struct sock *sp, char *tmpbuf, int i)
|
|
{
|
|
int timer_active;
|
|
unsigned long timer_expires;
|
|
struct tcp_sock *tp = tcp_sk(sp);
|
|
const struct inet_connection_sock *icsk = inet_csk(sp);
|
|
struct inet_sock *inet = inet_sk(sp);
|
|
__be32 dest = inet->daddr;
|
|
__be32 src = inet->rcv_saddr;
|
|
__u16 destp = ntohs(inet->dport);
|
|
__u16 srcp = ntohs(inet->sport);
|
|
|
|
if (icsk->icsk_pending == ICSK_TIME_RETRANS) {
|
|
timer_active = 1;
|
|
timer_expires = icsk->icsk_timeout;
|
|
} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
|
|
timer_active = 4;
|
|
timer_expires = icsk->icsk_timeout;
|
|
} else if (timer_pending(&sp->sk_timer)) {
|
|
timer_active = 2;
|
|
timer_expires = sp->sk_timer.expires;
|
|
} else {
|
|
timer_active = 0;
|
|
timer_expires = jiffies;
|
|
}
|
|
|
|
sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
|
|
"%08X %5d %8d %lu %d %p %u %u %u %u %d",
|
|
i, src, srcp, dest, destp, sp->sk_state,
|
|
tp->write_seq - tp->snd_una,
|
|
sp->sk_state == TCP_LISTEN ? sp->sk_ack_backlog :
|
|
(tp->rcv_nxt - tp->copied_seq),
|
|
timer_active,
|
|
jiffies_to_clock_t(timer_expires - jiffies),
|
|
icsk->icsk_retransmits,
|
|
sock_i_uid(sp),
|
|
icsk->icsk_probes_out,
|
|
sock_i_ino(sp),
|
|
atomic_read(&sp->sk_refcnt), sp,
|
|
icsk->icsk_rto,
|
|
icsk->icsk_ack.ato,
|
|
(icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
|
|
tp->snd_cwnd,
|
|
tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh);
|
|
}
|
|
|
|
static void get_timewait4_sock(struct inet_timewait_sock *tw,
|
|
char *tmpbuf, int i)
|
|
{
|
|
__be32 dest, src;
|
|
__u16 destp, srcp;
|
|
int ttd = tw->tw_ttd - jiffies;
|
|
|
|
if (ttd < 0)
|
|
ttd = 0;
|
|
|
|
dest = tw->tw_daddr;
|
|
src = tw->tw_rcv_saddr;
|
|
destp = ntohs(tw->tw_dport);
|
|
srcp = ntohs(tw->tw_sport);
|
|
|
|
sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
|
|
" %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p",
|
|
i, src, srcp, dest, destp, tw->tw_substate, 0, 0,
|
|
3, jiffies_to_clock_t(ttd), 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;
|
|
char tmpbuf[TMPSZ + 1];
|
|
|
|
if (v == SEQ_START_TOKEN) {
|
|
seq_printf(seq, "%-*s\n", TMPSZ - 1,
|
|
" sl local_address rem_address st tx_queue "
|
|
"rx_queue tr tm->when retrnsmt uid timeout "
|
|
"inode");
|
|
goto out;
|
|
}
|
|
st = seq->private;
|
|
|
|
switch (st->state) {
|
|
case TCP_SEQ_STATE_LISTENING:
|
|
case TCP_SEQ_STATE_ESTABLISHED:
|
|
get_tcp4_sock(v, tmpbuf, st->num);
|
|
break;
|
|
case TCP_SEQ_STATE_OPENREQ:
|
|
get_openreq4(st->syn_wait_sk, v, tmpbuf, st->num, st->uid);
|
|
break;
|
|
case TCP_SEQ_STATE_TIME_WAIT:
|
|
get_timewait4_sock(v, tmpbuf, st->num);
|
|
break;
|
|
}
|
|
seq_printf(seq, "%-*s\n", TMPSZ - 1, tmpbuf);
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
static struct file_operations tcp4_seq_fops;
|
|
static struct tcp_seq_afinfo tcp4_seq_afinfo = {
|
|
.owner = THIS_MODULE,
|
|
.name = "tcp",
|
|
.family = AF_INET,
|
|
.seq_show = tcp4_seq_show,
|
|
.seq_fops = &tcp4_seq_fops,
|
|
};
|
|
|
|
int __init tcp4_proc_init(void)
|
|
{
|
|
return tcp_proc_register(&tcp4_seq_afinfo);
|
|
}
|
|
|
|
void tcp4_proc_exit(void)
|
|
{
|
|
tcp_proc_unregister(&tcp4_seq_afinfo);
|
|
}
|
|
#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,
|
|
.sendmsg = tcp_sendmsg,
|
|
.recvmsg = tcp_recvmsg,
|
|
.backlog_rcv = tcp_v4_do_rcv,
|
|
.hash = tcp_v4_hash,
|
|
.unhash = tcp_unhash,
|
|
.get_port = tcp_v4_get_port,
|
|
.enter_memory_pressure = tcp_enter_memory_pressure,
|
|
.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),
|
|
.twsk_prot = &tcp_timewait_sock_ops,
|
|
.rsk_prot = &tcp_request_sock_ops,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_setsockopt = compat_tcp_setsockopt,
|
|
.compat_getsockopt = compat_tcp_getsockopt,
|
|
#endif
|
|
};
|
|
|
|
void __init tcp_v4_init(struct net_proto_family *ops)
|
|
{
|
|
if (inet_csk_ctl_sock_create(&tcp_socket, PF_INET, SOCK_RAW,
|
|
IPPROTO_TCP) < 0)
|
|
panic("Failed to create the TCP control socket.\n");
|
|
}
|
|
|
|
EXPORT_SYMBOL(ipv4_specific);
|
|
EXPORT_SYMBOL(tcp_hashinfo);
|
|
EXPORT_SYMBOL(tcp_prot);
|
|
EXPORT_SYMBOL(tcp_unhash);
|
|
EXPORT_SYMBOL(tcp_v4_conn_request);
|
|
EXPORT_SYMBOL(tcp_v4_connect);
|
|
EXPORT_SYMBOL(tcp_v4_do_rcv);
|
|
EXPORT_SYMBOL(tcp_v4_remember_stamp);
|
|
EXPORT_SYMBOL(tcp_v4_send_check);
|
|
EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
EXPORT_SYMBOL(tcp_proc_register);
|
|
EXPORT_SYMBOL(tcp_proc_unregister);
|
|
#endif
|
|
EXPORT_SYMBOL(sysctl_local_port_range);
|
|
EXPORT_SYMBOL(sysctl_tcp_low_latency);
|
|
|