![Stephen Hemminger](/assets/img/avatar_default.png)
Allow using setsockopt to set TCP congestion control to use on a per socket basis. Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2656 lines
64 KiB
C
2656 lines
64 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 sematics.
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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/config.h>
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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/tcp.h>
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#include <net/ipv6.h>
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#include <net/inet_common.h>
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#include <net/xfrm.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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extern int sysctl_ip_dynaddr;
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int sysctl_tcp_tw_reuse;
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int sysctl_tcp_low_latency;
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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, struct tcphdr *th, int len,
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struct sk_buff *skb);
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struct tcp_hashinfo __cacheline_aligned tcp_hashinfo = {
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.__tcp_lhash_lock = RW_LOCK_UNLOCKED,
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.__tcp_lhash_users = ATOMIC_INIT(0),
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.__tcp_lhash_wait
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= __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.__tcp_lhash_wait),
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.__tcp_portalloc_lock = SPIN_LOCK_UNLOCKED
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};
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/*
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* This array holds the first and last local port number.
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* For high-usage systems, use sysctl to change this to
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* 32768-61000
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*/
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int sysctl_local_port_range[2] = { 1024, 4999 };
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int tcp_port_rover = 1024 - 1;
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static __inline__ int tcp_hashfn(__u32 laddr, __u16 lport,
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__u32 faddr, __u16 fport)
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{
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int h = (laddr ^ lport) ^ (faddr ^ fport);
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h ^= h >> 16;
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h ^= h >> 8;
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return h & (tcp_ehash_size - 1);
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}
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static __inline__ int tcp_sk_hashfn(struct sock *sk)
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{
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struct inet_sock *inet = inet_sk(sk);
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__u32 laddr = inet->rcv_saddr;
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__u16 lport = inet->num;
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__u32 faddr = inet->daddr;
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__u16 fport = inet->dport;
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return tcp_hashfn(laddr, lport, faddr, fport);
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}
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/* Allocate and initialize a new TCP local port bind bucket.
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* The bindhash mutex for snum's hash chain must be held here.
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*/
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struct tcp_bind_bucket *tcp_bucket_create(struct tcp_bind_hashbucket *head,
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unsigned short snum)
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{
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struct tcp_bind_bucket *tb = kmem_cache_alloc(tcp_bucket_cachep,
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SLAB_ATOMIC);
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if (tb) {
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tb->port = snum;
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tb->fastreuse = 0;
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INIT_HLIST_HEAD(&tb->owners);
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hlist_add_head(&tb->node, &head->chain);
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}
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return tb;
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}
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/* Caller must hold hashbucket lock for this tb with local BH disabled */
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void tcp_bucket_destroy(struct tcp_bind_bucket *tb)
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{
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if (hlist_empty(&tb->owners)) {
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__hlist_del(&tb->node);
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kmem_cache_free(tcp_bucket_cachep, tb);
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}
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}
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/* Caller must disable local BH processing. */
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static __inline__ void __tcp_inherit_port(struct sock *sk, struct sock *child)
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{
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struct tcp_bind_hashbucket *head =
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&tcp_bhash[tcp_bhashfn(inet_sk(child)->num)];
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struct tcp_bind_bucket *tb;
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spin_lock(&head->lock);
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tb = tcp_sk(sk)->bind_hash;
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sk_add_bind_node(child, &tb->owners);
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tcp_sk(child)->bind_hash = tb;
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spin_unlock(&head->lock);
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}
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inline void tcp_inherit_port(struct sock *sk, struct sock *child)
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{
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local_bh_disable();
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__tcp_inherit_port(sk, child);
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local_bh_enable();
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}
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void tcp_bind_hash(struct sock *sk, struct tcp_bind_bucket *tb,
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unsigned short snum)
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{
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inet_sk(sk)->num = snum;
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sk_add_bind_node(sk, &tb->owners);
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tcp_sk(sk)->bind_hash = tb;
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}
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static inline int tcp_bind_conflict(struct sock *sk, struct tcp_bind_bucket *tb)
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{
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const u32 sk_rcv_saddr = tcp_v4_rcv_saddr(sk);
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struct sock *sk2;
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struct hlist_node *node;
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int reuse = sk->sk_reuse;
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sk_for_each_bound(sk2, node, &tb->owners) {
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if (sk != sk2 &&
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!tcp_v6_ipv6only(sk2) &&
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(!sk->sk_bound_dev_if ||
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!sk2->sk_bound_dev_if ||
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sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
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if (!reuse || !sk2->sk_reuse ||
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sk2->sk_state == TCP_LISTEN) {
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const u32 sk2_rcv_saddr = tcp_v4_rcv_saddr(sk2);
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if (!sk2_rcv_saddr || !sk_rcv_saddr ||
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sk2_rcv_saddr == sk_rcv_saddr)
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break;
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}
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}
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}
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return node != NULL;
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}
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/* Obtain a reference to a local port for the given sock,
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* if snum is zero it means select any available local port.
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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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struct tcp_bind_hashbucket *head;
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struct hlist_node *node;
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struct tcp_bind_bucket *tb;
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int ret;
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local_bh_disable();
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if (!snum) {
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int low = sysctl_local_port_range[0];
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int high = sysctl_local_port_range[1];
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int remaining = (high - low) + 1;
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int rover;
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spin_lock(&tcp_portalloc_lock);
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if (tcp_port_rover < low)
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rover = low;
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else
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rover = tcp_port_rover;
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do {
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rover++;
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if (rover > high)
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rover = low;
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head = &tcp_bhash[tcp_bhashfn(rover)];
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spin_lock(&head->lock);
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tb_for_each(tb, node, &head->chain)
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if (tb->port == rover)
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goto next;
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break;
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next:
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spin_unlock(&head->lock);
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} while (--remaining > 0);
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tcp_port_rover = rover;
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spin_unlock(&tcp_portalloc_lock);
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/* Exhausted local port range during search? */
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ret = 1;
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if (remaining <= 0)
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goto fail;
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/* OK, here is the one we will use. HEAD is
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* non-NULL and we hold it's mutex.
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*/
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snum = rover;
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} else {
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head = &tcp_bhash[tcp_bhashfn(snum)];
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spin_lock(&head->lock);
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tb_for_each(tb, node, &head->chain)
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if (tb->port == snum)
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goto tb_found;
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}
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tb = NULL;
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goto tb_not_found;
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tb_found:
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if (!hlist_empty(&tb->owners)) {
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if (sk->sk_reuse > 1)
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goto success;
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if (tb->fastreuse > 0 &&
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sk->sk_reuse && sk->sk_state != TCP_LISTEN) {
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goto success;
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} else {
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ret = 1;
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if (tcp_bind_conflict(sk, tb))
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goto fail_unlock;
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}
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}
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tb_not_found:
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ret = 1;
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if (!tb && (tb = tcp_bucket_create(head, snum)) == NULL)
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goto fail_unlock;
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if (hlist_empty(&tb->owners)) {
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if (sk->sk_reuse && sk->sk_state != TCP_LISTEN)
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tb->fastreuse = 1;
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else
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tb->fastreuse = 0;
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} else if (tb->fastreuse &&
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(!sk->sk_reuse || sk->sk_state == TCP_LISTEN))
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tb->fastreuse = 0;
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success:
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if (!tcp_sk(sk)->bind_hash)
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tcp_bind_hash(sk, tb, snum);
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BUG_TRAP(tcp_sk(sk)->bind_hash == tb);
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ret = 0;
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fail_unlock:
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spin_unlock(&head->lock);
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fail:
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local_bh_enable();
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return ret;
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}
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/* Get rid of any references to a local port held by the
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* given sock.
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*/
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static void __tcp_put_port(struct sock *sk)
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{
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struct inet_sock *inet = inet_sk(sk);
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struct tcp_bind_hashbucket *head = &tcp_bhash[tcp_bhashfn(inet->num)];
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struct tcp_bind_bucket *tb;
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spin_lock(&head->lock);
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tb = tcp_sk(sk)->bind_hash;
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__sk_del_bind_node(sk);
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tcp_sk(sk)->bind_hash = NULL;
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inet->num = 0;
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tcp_bucket_destroy(tb);
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spin_unlock(&head->lock);
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}
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void tcp_put_port(struct sock *sk)
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{
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local_bh_disable();
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__tcp_put_port(sk);
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local_bh_enable();
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}
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/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP.
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* Look, when several writers sleep and reader wakes them up, all but one
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* immediately hit write lock and grab all the cpus. Exclusive sleep solves
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* this, _but_ remember, it adds useless work on UP machines (wake up each
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* exclusive lock release). It should be ifdefed really.
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*/
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void tcp_listen_wlock(void)
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{
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write_lock(&tcp_lhash_lock);
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if (atomic_read(&tcp_lhash_users)) {
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DEFINE_WAIT(wait);
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for (;;) {
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prepare_to_wait_exclusive(&tcp_lhash_wait,
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&wait, TASK_UNINTERRUPTIBLE);
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if (!atomic_read(&tcp_lhash_users))
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break;
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write_unlock_bh(&tcp_lhash_lock);
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schedule();
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write_lock_bh(&tcp_lhash_lock);
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}
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finish_wait(&tcp_lhash_wait, &wait);
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}
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}
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static __inline__ void __tcp_v4_hash(struct sock *sk, const int listen_possible)
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{
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struct hlist_head *list;
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rwlock_t *lock;
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BUG_TRAP(sk_unhashed(sk));
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if (listen_possible && sk->sk_state == TCP_LISTEN) {
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list = &tcp_listening_hash[tcp_sk_listen_hashfn(sk)];
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lock = &tcp_lhash_lock;
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tcp_listen_wlock();
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} else {
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list = &tcp_ehash[(sk->sk_hashent = tcp_sk_hashfn(sk))].chain;
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lock = &tcp_ehash[sk->sk_hashent].lock;
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write_lock(lock);
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}
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__sk_add_node(sk, list);
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sock_prot_inc_use(sk->sk_prot);
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write_unlock(lock);
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if (listen_possible && sk->sk_state == TCP_LISTEN)
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wake_up(&tcp_lhash_wait);
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}
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|
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static void tcp_v4_hash(struct sock *sk)
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{
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if (sk->sk_state != TCP_CLOSE) {
|
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local_bh_disable();
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__tcp_v4_hash(sk, 1);
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local_bh_enable();
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}
|
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}
|
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|
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void tcp_unhash(struct sock *sk)
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{
|
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rwlock_t *lock;
|
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|
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if (sk_unhashed(sk))
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goto ende;
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|
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if (sk->sk_state == TCP_LISTEN) {
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local_bh_disable();
|
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tcp_listen_wlock();
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lock = &tcp_lhash_lock;
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} else {
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struct tcp_ehash_bucket *head = &tcp_ehash[sk->sk_hashent];
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lock = &head->lock;
|
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write_lock_bh(&head->lock);
|
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}
|
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|
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if (__sk_del_node_init(sk))
|
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sock_prot_dec_use(sk->sk_prot);
|
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write_unlock_bh(lock);
|
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|
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ende:
|
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if (sk->sk_state == TCP_LISTEN)
|
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wake_up(&tcp_lhash_wait);
|
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}
|
|
|
|
/* Don't inline this cruft. Here are some nice properties to
|
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* exploit here. The BSD API does not allow a listening TCP
|
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* to specify the remote port nor the remote address for the
|
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* connection. So always assume those are both wildcarded
|
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* during the search since they can never be otherwise.
|
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*/
|
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static struct sock *__tcp_v4_lookup_listener(struct hlist_head *head, u32 daddr,
|
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unsigned short hnum, int dif)
|
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{
|
|
struct sock *result = NULL, *sk;
|
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struct hlist_node *node;
|
|
int score, hiscore;
|
|
|
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hiscore=-1;
|
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sk_for_each(sk, node, head) {
|
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struct inet_sock *inet = inet_sk(sk);
|
|
|
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if (inet->num == hnum && !ipv6_only_sock(sk)) {
|
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__u32 rcv_saddr = inet->rcv_saddr;
|
|
|
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score = (sk->sk_family == PF_INET ? 1 : 0);
|
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if (rcv_saddr) {
|
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if (rcv_saddr != daddr)
|
|
continue;
|
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score+=2;
|
|
}
|
|
if (sk->sk_bound_dev_if) {
|
|
if (sk->sk_bound_dev_if != dif)
|
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continue;
|
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score+=2;
|
|
}
|
|
if (score == 5)
|
|
return sk;
|
|
if (score > hiscore) {
|
|
hiscore = score;
|
|
result = sk;
|
|
}
|
|
}
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/* Optimize the common listener case. */
|
|
static inline struct sock *tcp_v4_lookup_listener(u32 daddr,
|
|
unsigned short hnum, int dif)
|
|
{
|
|
struct sock *sk = NULL;
|
|
struct hlist_head *head;
|
|
|
|
read_lock(&tcp_lhash_lock);
|
|
head = &tcp_listening_hash[tcp_lhashfn(hnum)];
|
|
if (!hlist_empty(head)) {
|
|
struct inet_sock *inet = inet_sk((sk = __sk_head(head)));
|
|
|
|
if (inet->num == hnum && !sk->sk_node.next &&
|
|
(!inet->rcv_saddr || inet->rcv_saddr == daddr) &&
|
|
(sk->sk_family == PF_INET || !ipv6_only_sock(sk)) &&
|
|
!sk->sk_bound_dev_if)
|
|
goto sherry_cache;
|
|
sk = __tcp_v4_lookup_listener(head, daddr, hnum, dif);
|
|
}
|
|
if (sk) {
|
|
sherry_cache:
|
|
sock_hold(sk);
|
|
}
|
|
read_unlock(&tcp_lhash_lock);
|
|
return sk;
|
|
}
|
|
|
|
/* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
|
|
* we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
|
|
*
|
|
* Local BH must be disabled here.
|
|
*/
|
|
|
|
static inline struct sock *__tcp_v4_lookup_established(u32 saddr, u16 sport,
|
|
u32 daddr, u16 hnum,
|
|
int dif)
|
|
{
|
|
struct tcp_ehash_bucket *head;
|
|
TCP_V4_ADDR_COOKIE(acookie, saddr, daddr)
|
|
__u32 ports = TCP_COMBINED_PORTS(sport, hnum);
|
|
struct sock *sk;
|
|
struct hlist_node *node;
|
|
/* Optimize here for direct hit, only listening connections can
|
|
* have wildcards anyways.
|
|
*/
|
|
int hash = tcp_hashfn(daddr, hnum, saddr, sport);
|
|
head = &tcp_ehash[hash];
|
|
read_lock(&head->lock);
|
|
sk_for_each(sk, node, &head->chain) {
|
|
if (TCP_IPV4_MATCH(sk, acookie, saddr, daddr, ports, dif))
|
|
goto hit; /* You sunk my battleship! */
|
|
}
|
|
|
|
/* Must check for a TIME_WAIT'er before going to listener hash. */
|
|
sk_for_each(sk, node, &(head + tcp_ehash_size)->chain) {
|
|
if (TCP_IPV4_TW_MATCH(sk, acookie, saddr, daddr, ports, dif))
|
|
goto hit;
|
|
}
|
|
sk = NULL;
|
|
out:
|
|
read_unlock(&head->lock);
|
|
return sk;
|
|
hit:
|
|
sock_hold(sk);
|
|
goto out;
|
|
}
|
|
|
|
static inline struct sock *__tcp_v4_lookup(u32 saddr, u16 sport,
|
|
u32 daddr, u16 hnum, int dif)
|
|
{
|
|
struct sock *sk = __tcp_v4_lookup_established(saddr, sport,
|
|
daddr, hnum, dif);
|
|
|
|
return sk ? : tcp_v4_lookup_listener(daddr, hnum, dif);
|
|
}
|
|
|
|
inline struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr,
|
|
u16 dport, int dif)
|
|
{
|
|
struct sock *sk;
|
|
|
|
local_bh_disable();
|
|
sk = __tcp_v4_lookup(saddr, sport, daddr, ntohs(dport), dif);
|
|
local_bh_enable();
|
|
|
|
return sk;
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(tcp_v4_lookup);
|
|
|
|
static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
return secure_tcp_sequence_number(skb->nh.iph->daddr,
|
|
skb->nh.iph->saddr,
|
|
skb->h.th->dest,
|
|
skb->h.th->source);
|
|
}
|
|
|
|
/* called with local bh disabled */
|
|
static int __tcp_v4_check_established(struct sock *sk, __u16 lport,
|
|
struct tcp_tw_bucket **twp)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
u32 daddr = inet->rcv_saddr;
|
|
u32 saddr = inet->daddr;
|
|
int dif = sk->sk_bound_dev_if;
|
|
TCP_V4_ADDR_COOKIE(acookie, saddr, daddr)
|
|
__u32 ports = TCP_COMBINED_PORTS(inet->dport, lport);
|
|
int hash = tcp_hashfn(daddr, lport, saddr, inet->dport);
|
|
struct tcp_ehash_bucket *head = &tcp_ehash[hash];
|
|
struct sock *sk2;
|
|
struct hlist_node *node;
|
|
struct tcp_tw_bucket *tw;
|
|
|
|
write_lock(&head->lock);
|
|
|
|
/* Check TIME-WAIT sockets first. */
|
|
sk_for_each(sk2, node, &(head + tcp_ehash_size)->chain) {
|
|
tw = (struct tcp_tw_bucket *)sk2;
|
|
|
|
if (TCP_IPV4_TW_MATCH(sk2, acookie, saddr, daddr, ports, dif)) {
|
|
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 (tw->tw_ts_recent_stamp &&
|
|
(!twp || (sysctl_tcp_tw_reuse &&
|
|
xtime.tv_sec -
|
|
tw->tw_ts_recent_stamp > 1))) {
|
|
if ((tp->write_seq =
|
|
tw->tw_snd_nxt + 65535 + 2) == 0)
|
|
tp->write_seq = 1;
|
|
tp->rx_opt.ts_recent = tw->tw_ts_recent;
|
|
tp->rx_opt.ts_recent_stamp = tw->tw_ts_recent_stamp;
|
|
sock_hold(sk2);
|
|
goto unique;
|
|
} else
|
|
goto not_unique;
|
|
}
|
|
}
|
|
tw = NULL;
|
|
|
|
/* And established part... */
|
|
sk_for_each(sk2, node, &head->chain) {
|
|
if (TCP_IPV4_MATCH(sk2, acookie, saddr, daddr, ports, dif))
|
|
goto not_unique;
|
|
}
|
|
|
|
unique:
|
|
/* Must record num and sport now. Otherwise we will see
|
|
* in hash table socket with a funny identity. */
|
|
inet->num = lport;
|
|
inet->sport = htons(lport);
|
|
sk->sk_hashent = hash;
|
|
BUG_TRAP(sk_unhashed(sk));
|
|
__sk_add_node(sk, &head->chain);
|
|
sock_prot_inc_use(sk->sk_prot);
|
|
write_unlock(&head->lock);
|
|
|
|
if (twp) {
|
|
*twp = tw;
|
|
NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
|
|
} else if (tw) {
|
|
/* Silly. Should hash-dance instead... */
|
|
tcp_tw_deschedule(tw);
|
|
NET_INC_STATS_BH(LINUX_MIB_TIMEWAITRECYCLED);
|
|
|
|
tcp_tw_put(tw);
|
|
}
|
|
|
|
return 0;
|
|
|
|
not_unique:
|
|
write_unlock(&head->lock);
|
|
return -EADDRNOTAVAIL;
|
|
}
|
|
|
|
static inline u32 connect_port_offset(const struct sock *sk)
|
|
{
|
|
const struct inet_sock *inet = inet_sk(sk);
|
|
|
|
return secure_tcp_port_ephemeral(inet->rcv_saddr, inet->daddr,
|
|
inet->dport);
|
|
}
|
|
|
|
/*
|
|
* Bind a port for a connect operation and hash it.
|
|
*/
|
|
static inline int tcp_v4_hash_connect(struct sock *sk)
|
|
{
|
|
unsigned short snum = inet_sk(sk)->num;
|
|
struct tcp_bind_hashbucket *head;
|
|
struct tcp_bind_bucket *tb;
|
|
int ret;
|
|
|
|
if (!snum) {
|
|
int low = sysctl_local_port_range[0];
|
|
int high = sysctl_local_port_range[1];
|
|
int range = high - low;
|
|
int i;
|
|
int port;
|
|
static u32 hint;
|
|
u32 offset = hint + connect_port_offset(sk);
|
|
struct hlist_node *node;
|
|
struct tcp_tw_bucket *tw = NULL;
|
|
|
|
local_bh_disable();
|
|
for (i = 1; i <= range; i++) {
|
|
port = low + (i + offset) % range;
|
|
head = &tcp_bhash[tcp_bhashfn(port)];
|
|
spin_lock(&head->lock);
|
|
|
|
/* Does not bother with rcv_saddr checks,
|
|
* because the established check is already
|
|
* unique enough.
|
|
*/
|
|
tb_for_each(tb, node, &head->chain) {
|
|
if (tb->port == port) {
|
|
BUG_TRAP(!hlist_empty(&tb->owners));
|
|
if (tb->fastreuse >= 0)
|
|
goto next_port;
|
|
if (!__tcp_v4_check_established(sk,
|
|
port,
|
|
&tw))
|
|
goto ok;
|
|
goto next_port;
|
|
}
|
|
}
|
|
|
|
tb = tcp_bucket_create(head, port);
|
|
if (!tb) {
|
|
spin_unlock(&head->lock);
|
|
break;
|
|
}
|
|
tb->fastreuse = -1;
|
|
goto ok;
|
|
|
|
next_port:
|
|
spin_unlock(&head->lock);
|
|
}
|
|
local_bh_enable();
|
|
|
|
return -EADDRNOTAVAIL;
|
|
|
|
ok:
|
|
hint += i;
|
|
|
|
/* Head lock still held and bh's disabled */
|
|
tcp_bind_hash(sk, tb, port);
|
|
if (sk_unhashed(sk)) {
|
|
inet_sk(sk)->sport = htons(port);
|
|
__tcp_v4_hash(sk, 0);
|
|
}
|
|
spin_unlock(&head->lock);
|
|
|
|
if (tw) {
|
|
tcp_tw_deschedule(tw);
|
|
tcp_tw_put(tw);
|
|
}
|
|
|
|
ret = 0;
|
|
goto out;
|
|
}
|
|
|
|
head = &tcp_bhash[tcp_bhashfn(snum)];
|
|
tb = tcp_sk(sk)->bind_hash;
|
|
spin_lock_bh(&head->lock);
|
|
if (sk_head(&tb->owners) == sk && !sk->sk_bind_node.next) {
|
|
__tcp_v4_hash(sk, 0);
|
|
spin_unlock_bh(&head->lock);
|
|
return 0;
|
|
} else {
|
|
spin_unlock(&head->lock);
|
|
/* No definite answer... Walk to established hash table */
|
|
ret = __tcp_v4_check_established(sk, snum, NULL);
|
|
out:
|
|
local_bh_enable();
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
/* This will initiate an outgoing connection. */
|
|
int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct sockaddr_in *usin = (struct sockaddr_in *)uaddr;
|
|
struct rtable *rt;
|
|
u32 daddr, nexthop;
|
|
int tmp;
|
|
int err;
|
|
|
|
if (addr_len < sizeof(struct sockaddr_in))
|
|
return -EINVAL;
|
|
|
|
if (usin->sin_family != AF_INET)
|
|
return -EAFNOSUPPORT;
|
|
|
|
nexthop = daddr = usin->sin_addr.s_addr;
|
|
if (inet->opt && inet->opt->srr) {
|
|
if (!daddr)
|
|
return -EINVAL;
|
|
nexthop = inet->opt->faddr;
|
|
}
|
|
|
|
tmp = ip_route_connect(&rt, nexthop, inet->saddr,
|
|
RT_CONN_FLAGS(sk), sk->sk_bound_dev_if,
|
|
IPPROTO_TCP,
|
|
inet->sport, usin->sin_port, sk);
|
|
if (tmp < 0)
|
|
return tmp;
|
|
|
|
if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) {
|
|
ip_rt_put(rt);
|
|
return -ENETUNREACH;
|
|
}
|
|
|
|
if (!inet->opt || !inet->opt->srr)
|
|
daddr = rt->rt_dst;
|
|
|
|
if (!inet->saddr)
|
|
inet->saddr = rt->rt_src;
|
|
inet->rcv_saddr = inet->saddr;
|
|
|
|
if (tp->rx_opt.ts_recent_stamp && inet->daddr != daddr) {
|
|
/* Reset inherited state */
|
|
tp->rx_opt.ts_recent = 0;
|
|
tp->rx_opt.ts_recent_stamp = 0;
|
|
tp->write_seq = 0;
|
|
}
|
|
|
|
if (sysctl_tcp_tw_recycle &&
|
|
!tp->rx_opt.ts_recent_stamp && rt->rt_dst == daddr) {
|
|
struct inet_peer *peer = rt_get_peer(rt);
|
|
|
|
/* VJ's idea. We save last timestamp seen from
|
|
* the destination in peer table, when entering state TIME-WAIT
|
|
* and initialize rx_opt.ts_recent from it, when trying new connection.
|
|
*/
|
|
|
|
if (peer && peer->tcp_ts_stamp + TCP_PAWS_MSL >= xtime.tv_sec) {
|
|
tp->rx_opt.ts_recent_stamp = peer->tcp_ts_stamp;
|
|
tp->rx_opt.ts_recent = peer->tcp_ts;
|
|
}
|
|
}
|
|
|
|
inet->dport = usin->sin_port;
|
|
inet->daddr = daddr;
|
|
|
|
tp->ext_header_len = 0;
|
|
if (inet->opt)
|
|
tp->ext_header_len = inet->opt->optlen;
|
|
|
|
tp->rx_opt.mss_clamp = 536;
|
|
|
|
/* 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 = tcp_v4_hash_connect(sk);
|
|
if (err)
|
|
goto failure;
|
|
|
|
err = ip_route_newports(&rt, inet->sport, inet->dport, sk);
|
|
if (err)
|
|
goto failure;
|
|
|
|
/* OK, now commit destination to socket. */
|
|
__sk_dst_set(sk, &rt->u.dst);
|
|
tcp_v4_setup_caps(sk, &rt->u.dst);
|
|
|
|
if (!tp->write_seq)
|
|
tp->write_seq = secure_tcp_sequence_number(inet->saddr,
|
|
inet->daddr,
|
|
inet->sport,
|
|
usin->sin_port);
|
|
|
|
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->dport = 0;
|
|
return err;
|
|
}
|
|
|
|
static __inline__ int tcp_v4_iif(struct sk_buff *skb)
|
|
{
|
|
return ((struct rtable *)skb->dst)->rt_iif;
|
|
}
|
|
|
|
static __inline__ u32 tcp_v4_synq_hash(u32 raddr, u16 rport, u32 rnd)
|
|
{
|
|
return (jhash_2words(raddr, (u32) rport, rnd) & (TCP_SYNQ_HSIZE - 1));
|
|
}
|
|
|
|
static struct request_sock *tcp_v4_search_req(struct tcp_sock *tp,
|
|
struct request_sock ***prevp,
|
|
__u16 rport,
|
|
__u32 raddr, __u32 laddr)
|
|
{
|
|
struct listen_sock *lopt = tp->accept_queue.listen_opt;
|
|
struct request_sock *req, **prev;
|
|
|
|
for (prev = &lopt->syn_table[tcp_v4_synq_hash(raddr, rport, lopt->hash_rnd)];
|
|
(req = *prev) != NULL;
|
|
prev = &req->dl_next) {
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
|
|
if (ireq->rmt_port == rport &&
|
|
ireq->rmt_addr == raddr &&
|
|
ireq->loc_addr == laddr &&
|
|
TCP_INET_FAMILY(req->rsk_ops->family)) {
|
|
BUG_TRAP(!req->sk);
|
|
*prevp = prev;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return req;
|
|
}
|
|
|
|
static void tcp_v4_synq_add(struct sock *sk, struct request_sock *req)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct listen_sock *lopt = tp->accept_queue.listen_opt;
|
|
u32 h = tcp_v4_synq_hash(inet_rsk(req)->rmt_addr, inet_rsk(req)->rmt_port, lopt->hash_rnd);
|
|
|
|
reqsk_queue_hash_req(&tp->accept_queue, h, req, TCP_TIMEOUT_INIT);
|
|
tcp_synq_added(sk);
|
|
}
|
|
|
|
|
|
/*
|
|
* This routine does path mtu discovery as defined in RFC1191.
|
|
*/
|
|
static inline void do_pmtu_discovery(struct sock *sk, struct iphdr *iph,
|
|
u32 mtu)
|
|
{
|
|
struct dst_entry *dst;
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
/* 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)
|
|
return;
|
|
|
|
/* We don't check in the destentry if pmtu discovery is forbidden
|
|
* on this route. We just assume that no packet_to_big packets
|
|
* are send back when pmtu discovery is not active.
|
|
* There is a small race when the user changes this flag in the
|
|
* route, but I think that's acceptable.
|
|
*/
|
|
if ((dst = __sk_dst_check(sk, 0)) == NULL)
|
|
return;
|
|
|
|
dst->ops->update_pmtu(dst, mtu);
|
|
|
|
/* 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 &&
|
|
tp->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 */
|
|
}
|
|
|
|
/*
|
|
* 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 *skb, u32 info)
|
|
{
|
|
struct iphdr *iph = (struct iphdr *)skb->data;
|
|
struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2));
|
|
struct tcp_sock *tp;
|
|
struct inet_sock *inet;
|
|
int type = skb->h.icmph->type;
|
|
int code = skb->h.icmph->code;
|
|
struct sock *sk;
|
|
__u32 seq;
|
|
int err;
|
|
|
|
if (skb->len < (iph->ihl << 2) + 8) {
|
|
ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
|
|
return;
|
|
}
|
|
|
|
sk = tcp_v4_lookup(iph->daddr, th->dest, iph->saddr,
|
|
th->source, tcp_v4_iif(skb));
|
|
if (!sk) {
|
|
ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
|
|
return;
|
|
}
|
|
if (sk->sk_state == TCP_TIME_WAIT) {
|
|
tcp_tw_put((struct tcp_tw_bucket *)sk);
|
|
return;
|
|
}
|
|
|
|
bh_lock_sock(sk);
|
|
/* If too many ICMPs get dropped on busy
|
|
* servers this needs to be solved differently.
|
|
*/
|
|
if (sock_owned_by_user(sk))
|
|
NET_INC_STATS_BH(LINUX_MIB_LOCKDROPPEDICMPS);
|
|
|
|
if (sk->sk_state == TCP_CLOSE)
|
|
goto out;
|
|
|
|
tp = tcp_sk(sk);
|
|
seq = ntohl(th->seq);
|
|
if (sk->sk_state != TCP_LISTEN &&
|
|
!between(seq, tp->snd_una, tp->snd_nxt)) {
|
|
NET_INC_STATS(LINUX_MIB_OUTOFWINDOWICMPS);
|
|
goto out;
|
|
}
|
|
|
|
switch (type) {
|
|
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) */
|
|
if (!sock_owned_by_user(sk))
|
|
do_pmtu_discovery(sk, iph, info);
|
|
goto out;
|
|
}
|
|
|
|
err = icmp_err_convert[code].errno;
|
|
break;
|
|
case ICMP_TIME_EXCEEDED:
|
|
err = EHOSTUNREACH;
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
|
|
switch (sk->sk_state) {
|
|
struct request_sock *req, **prev;
|
|
case TCP_LISTEN:
|
|
if (sock_owned_by_user(sk))
|
|
goto out;
|
|
|
|
req = tcp_v4_search_req(tp, &prev, th->dest,
|
|
iph->daddr, iph->saddr);
|
|
if (!req)
|
|
goto out;
|
|
|
|
/* ICMPs are not backlogged, hence we cannot get
|
|
an established socket here.
|
|
*/
|
|
BUG_TRAP(!req->sk);
|
|
|
|
if (seq != tcp_rsk(req)->snt_isn) {
|
|
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().
|
|
*/
|
|
tcp_synq_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)) {
|
|
TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
|
|
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, struct tcphdr *th, int len,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
if (skb->ip_summed == CHECKSUM_HW) {
|
|
th->check = ~tcp_v4_check(th, len, inet->saddr, inet->daddr, 0);
|
|
skb->csum = offsetof(struct tcphdr, check);
|
|
} else {
|
|
th->check = tcp_v4_check(th, len, inet->saddr, inet->daddr,
|
|
csum_partial((char *)th,
|
|
th->doff << 2,
|
|
skb->csum));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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 sk_buff *skb)
|
|
{
|
|
struct tcphdr *th = skb->h.th;
|
|
struct tcphdr rth;
|
|
struct ip_reply_arg arg;
|
|
|
|
/* 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(&rth, 0, sizeof(struct tcphdr));
|
|
rth.dest = th->source;
|
|
rth.source = th->dest;
|
|
rth.doff = sizeof(struct tcphdr) / 4;
|
|
rth.rst = 1;
|
|
|
|
if (th->ack) {
|
|
rth.seq = th->ack_seq;
|
|
} else {
|
|
rth.ack = 1;
|
|
rth.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 *)&rth;
|
|
arg.iov[0].iov_len = sizeof rth;
|
|
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, sizeof rth);
|
|
|
|
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 sk_buff *skb, u32 seq, u32 ack,
|
|
u32 win, u32 ts)
|
|
{
|
|
struct tcphdr *th = skb->h.th;
|
|
struct {
|
|
struct tcphdr th;
|
|
u32 tsopt[3];
|
|
} rep;
|
|
struct ip_reply_arg arg;
|
|
|
|
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.tsopt[0] = htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) |
|
|
(TCPOPT_TIMESTAMP << 8) |
|
|
TCPOLEN_TIMESTAMP);
|
|
rep.tsopt[1] = htonl(tcp_time_stamp);
|
|
rep.tsopt[2] = htonl(ts);
|
|
arg.iov[0].iov_len = sizeof(rep);
|
|
}
|
|
|
|
/* 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);
|
|
|
|
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 tcp_tw_bucket *tw = (struct tcp_tw_bucket *)sk;
|
|
|
|
tcp_v4_send_ack(skb, tw->tw_snd_nxt, tw->tw_rcv_nxt,
|
|
tw->tw_rcv_wnd >> tw->tw_rcv_wscale, tw->tw_ts_recent);
|
|
|
|
tcp_tw_put(tw);
|
|
}
|
|
|
|
static void tcp_v4_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req)
|
|
{
|
|
tcp_v4_send_ack(skb, tcp_rsk(req)->snt_isn + 1, tcp_rsk(req)->rcv_isn + 1, req->rcv_wnd,
|
|
req->ts_recent);
|
|
}
|
|
|
|
static struct dst_entry* tcp_v4_route_req(struct sock *sk,
|
|
struct request_sock *req)
|
|
{
|
|
struct rtable *rt;
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
struct ip_options *opt = inet_rsk(req)->opt;
|
|
struct flowi fl = { .oif = sk->sk_bound_dev_if,
|
|
.nl_u = { .ip4_u =
|
|
{ .daddr = ((opt && opt->srr) ?
|
|
opt->faddr :
|
|
ireq->rmt_addr),
|
|
.saddr = ireq->loc_addr,
|
|
.tos = RT_CONN_FLAGS(sk) } },
|
|
.proto = IPPROTO_TCP,
|
|
.uli_u = { .ports =
|
|
{ .sport = inet_sk(sk)->sport,
|
|
.dport = ireq->rmt_port } } };
|
|
|
|
if (ip_route_output_flow(&rt, &fl, sk, 0)) {
|
|
IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
|
|
return NULL;
|
|
}
|
|
if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
|
|
ip_rt_put(rt);
|
|
IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
|
|
return NULL;
|
|
}
|
|
return &rt->u.dst;
|
|
}
|
|
|
|
/*
|
|
* 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 = tcp_v4_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(th, 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);
|
|
if (err == NET_XMIT_CN)
|
|
err = 0;
|
|
}
|
|
|
|
out:
|
|
dst_release(dst);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* IPv4 request_sock destructor.
|
|
*/
|
|
static void tcp_v4_reqsk_destructor(struct request_sock *req)
|
|
{
|
|
if (inet_rsk(req)->opt)
|
|
kfree(inet_rsk(req)->opt);
|
|
}
|
|
|
|
static inline 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));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Save and compile IPv4 options into the request_sock if needed.
|
|
*/
|
|
static inline 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;
|
|
}
|
|
|
|
struct request_sock_ops tcp_request_sock_ops = {
|
|
.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,
|
|
};
|
|
|
|
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;
|
|
__u32 saddr = skb->nh.iph->saddr;
|
|
__u32 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 (tcp_synq_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) && tcp_synq_young(sk) > 1)
|
|
goto drop;
|
|
|
|
req = reqsk_alloc(&tcp_request_sock_ops);
|
|
if (!req)
|
|
goto drop;
|
|
|
|
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);
|
|
|
|
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 &&
|
|
sysctl_tcp_tw_recycle &&
|
|
(dst = tcp_v4_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 - tcp_synq_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.
|
|
*/
|
|
NETDEBUG(if (net_ratelimit()) \
|
|
printk(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(sk, 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 {
|
|
tcp_v4_synq_add(sk, req);
|
|
}
|
|
return 0;
|
|
|
|
drop_and_free:
|
|
reqsk_free(req);
|
|
drop:
|
|
TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS);
|
|
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;
|
|
|
|
if (sk_acceptq_is_full(sk))
|
|
goto exit_overflow;
|
|
|
|
if (!dst && (dst = tcp_v4_route_req(sk, req)) == NULL)
|
|
goto exit;
|
|
|
|
newsk = tcp_create_openreq_child(sk, req, skb);
|
|
if (!newsk)
|
|
goto exit;
|
|
|
|
newsk->sk_dst_cache = dst;
|
|
tcp_v4_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 = tcp_v4_iif(skb);
|
|
newinet->mc_ttl = skb->nh.iph->ttl;
|
|
newtp->ext_header_len = 0;
|
|
if (newinet->opt)
|
|
newtp->ext_header_len = newinet->opt->optlen;
|
|
newinet->id = newtp->write_seq ^ jiffies;
|
|
|
|
tcp_sync_mss(newsk, dst_mtu(dst));
|
|
newtp->advmss = dst_metric(dst, RTAX_ADVMSS);
|
|
tcp_initialize_rcv_mss(newsk);
|
|
|
|
__tcp_v4_hash(newsk, 0);
|
|
__tcp_inherit_port(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 tcp_sock *tp = tcp_sk(sk);
|
|
struct sock *nsk;
|
|
struct request_sock **prev;
|
|
/* Find possible connection requests. */
|
|
struct request_sock *req = tcp_v4_search_req(tp, &prev, th->source,
|
|
iph->saddr, iph->daddr);
|
|
if (req)
|
|
return tcp_check_req(sk, skb, req, prev);
|
|
|
|
nsk = __tcp_v4_lookup_established(skb->nh.iph->saddr,
|
|
th->source,
|
|
skb->nh.iph->daddr,
|
|
ntohs(th->dest),
|
|
tcp_v4_iif(skb));
|
|
|
|
if (nsk) {
|
|
if (nsk->sk_state != TCP_TIME_WAIT) {
|
|
bh_lock_sock(nsk);
|
|
return nsk;
|
|
}
|
|
tcp_tw_put((struct tcp_tw_bucket *)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 int tcp_v4_checksum_init(struct sk_buff *skb)
|
|
{
|
|
if (skb->ip_summed == CHECKSUM_HW) {
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
if (!tcp_v4_check(skb->h.th, skb->len, skb->nh.iph->saddr,
|
|
skb->nh.iph->daddr, skb->csum))
|
|
return 0;
|
|
|
|
NETDEBUG(if (net_ratelimit())
|
|
printk(KERN_DEBUG "hw tcp v4 csum failed\n"));
|
|
skb->ip_summed = CHECKSUM_NONE;
|
|
}
|
|
if (skb->len <= 76) {
|
|
if (tcp_v4_check(skb->h.th, skb->len, skb->nh.iph->saddr,
|
|
skb->nh.iph->daddr,
|
|
skb_checksum(skb, 0, skb->len, 0)))
|
|
return -1;
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
} else {
|
|
skb->csum = ~tcp_v4_check(skb->h.th, skb->len,
|
|
skb->nh.iph->saddr,
|
|
skb->nh.iph->daddr, 0);
|
|
}
|
|
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)
|
|
{
|
|
if (sk->sk_state == TCP_ESTABLISHED) { /* Fast path */
|
|
TCP_CHECK_TIMER(sk);
|
|
if (tcp_rcv_established(sk, skb, skb->h.th, skb->len))
|
|
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))
|
|
goto reset;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
TCP_CHECK_TIMER(sk);
|
|
if (tcp_rcv_state_process(sk, skb, skb->h.th, skb->len))
|
|
goto reset;
|
|
TCP_CHECK_TIMER(sk);
|
|
return 0;
|
|
|
|
reset:
|
|
tcp_v4_send_reset(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 elimineted.
|
|
* So, we defer the checks. */
|
|
if ((skb->ip_summed != CHECKSUM_UNNECESSARY &&
|
|
tcp_v4_checksum_init(skb) < 0))
|
|
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 = __tcp_v4_lookup(skb->nh.iph->saddr, th->source,
|
|
skb->nh.iph->daddr, ntohs(th->dest),
|
|
tcp_v4_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;
|
|
|
|
if (sk_filter(sk, skb, 0))
|
|
goto discard_and_relse;
|
|
|
|
skb->dev = NULL;
|
|
|
|
bh_lock_sock(sk);
|
|
ret = 0;
|
|
if (!sock_owned_by_user(sk)) {
|
|
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(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)) {
|
|
tcp_tw_put((struct tcp_tw_bucket *) sk);
|
|
goto discard_it;
|
|
}
|
|
|
|
if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
|
|
TCP_INC_STATS_BH(TCP_MIB_INERRS);
|
|
tcp_tw_put((struct tcp_tw_bucket *) sk);
|
|
goto discard_it;
|
|
}
|
|
switch (tcp_timewait_state_process((struct tcp_tw_bucket *)sk,
|
|
skb, th, skb->len)) {
|
|
case TCP_TW_SYN: {
|
|
struct sock *sk2 = tcp_v4_lookup_listener(skb->nh.iph->daddr,
|
|
ntohs(th->dest),
|
|
tcp_v4_iif(skb));
|
|
if (sk2) {
|
|
tcp_tw_deschedule((struct tcp_tw_bucket *)sk);
|
|
tcp_tw_put((struct tcp_tw_bucket *)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;
|
|
}
|
|
|
|
/* With per-bucket locks this operation is not-atomic, so that
|
|
* this version is not worse.
|
|
*/
|
|
static void __tcp_v4_rehash(struct sock *sk)
|
|
{
|
|
sk->sk_prot->unhash(sk);
|
|
sk->sk_prot->hash(sk);
|
|
}
|
|
|
|
static int tcp_v4_reselect_saddr(struct sock *sk)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
int err;
|
|
struct rtable *rt;
|
|
__u32 old_saddr = inet->saddr;
|
|
__u32 new_saddr;
|
|
__u32 daddr = inet->daddr;
|
|
|
|
if (inet->opt && inet->opt->srr)
|
|
daddr = inet->opt->faddr;
|
|
|
|
/* Query new route. */
|
|
err = ip_route_connect(&rt, daddr, 0,
|
|
RT_CONN_FLAGS(sk),
|
|
sk->sk_bound_dev_if,
|
|
IPPROTO_TCP,
|
|
inet->sport, inet->dport, sk);
|
|
if (err)
|
|
return err;
|
|
|
|
__sk_dst_set(sk, &rt->u.dst);
|
|
tcp_v4_setup_caps(sk, &rt->u.dst);
|
|
|
|
new_saddr = rt->rt_src;
|
|
|
|
if (new_saddr == old_saddr)
|
|
return 0;
|
|
|
|
if (sysctl_ip_dynaddr > 1) {
|
|
printk(KERN_INFO "tcp_v4_rebuild_header(): shifting inet->"
|
|
"saddr from %d.%d.%d.%d to %d.%d.%d.%d\n",
|
|
NIPQUAD(old_saddr),
|
|
NIPQUAD(new_saddr));
|
|
}
|
|
|
|
inet->saddr = new_saddr;
|
|
inet->rcv_saddr = new_saddr;
|
|
|
|
/* XXX The only one ugly spot where we need to
|
|
* XXX really change the sockets identity after
|
|
* XXX it has entered the hashes. -DaveM
|
|
*
|
|
* Besides that, it does not check for connection
|
|
* uniqueness. Wait for troubles.
|
|
*/
|
|
__tcp_v4_rehash(sk);
|
|
return 0;
|
|
}
|
|
|
|
int tcp_v4_rebuild_header(struct sock *sk)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
|
|
u32 daddr;
|
|
int err;
|
|
|
|
/* Route is OK, nothing to do. */
|
|
if (rt)
|
|
return 0;
|
|
|
|
/* Reroute. */
|
|
daddr = inet->daddr;
|
|
if (inet->opt && inet->opt->srr)
|
|
daddr = inet->opt->faddr;
|
|
|
|
{
|
|
struct flowi fl = { .oif = sk->sk_bound_dev_if,
|
|
.nl_u = { .ip4_u =
|
|
{ .daddr = daddr,
|
|
.saddr = inet->saddr,
|
|
.tos = RT_CONN_FLAGS(sk) } },
|
|
.proto = IPPROTO_TCP,
|
|
.uli_u = { .ports =
|
|
{ .sport = inet->sport,
|
|
.dport = inet->dport } } };
|
|
|
|
err = ip_route_output_flow(&rt, &fl, sk, 0);
|
|
}
|
|
if (!err) {
|
|
__sk_dst_set(sk, &rt->u.dst);
|
|
tcp_v4_setup_caps(sk, &rt->u.dst);
|
|
return 0;
|
|
}
|
|
|
|
/* Routing failed... */
|
|
sk->sk_route_caps = 0;
|
|
|
|
if (!sysctl_ip_dynaddr ||
|
|
sk->sk_state != TCP_SYN_SENT ||
|
|
(sk->sk_userlocks & SOCK_BINDADDR_LOCK) ||
|
|
(err = tcp_v4_reselect_saddr(sk)) != 0)
|
|
sk->sk_err_soft = -err;
|
|
|
|
return err;
|
|
}
|
|
|
|
static void v4_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
|
|
{
|
|
struct sockaddr_in *sin = (struct sockaddr_in *) uaddr;
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
sin->sin_family = AF_INET;
|
|
sin->sin_addr.s_addr = inet->daddr;
|
|
sin->sin_port = inet->dport;
|
|
}
|
|
|
|
/* 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 tcp_tw_bucket *tw)
|
|
{
|
|
struct inet_peer *peer = NULL;
|
|
|
|
peer = inet_getpeer(tw->tw_daddr, 1);
|
|
|
|
if (peer) {
|
|
if ((s32)(peer->tcp_ts - tw->tw_ts_recent) <= 0 ||
|
|
(peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec &&
|
|
peer->tcp_ts_stamp <= tw->tw_ts_recent_stamp)) {
|
|
peer->tcp_ts_stamp = tw->tw_ts_recent_stamp;
|
|
peer->tcp_ts = tw->tw_ts_recent;
|
|
}
|
|
inet_putpeer(peer);
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct tcp_func ipv4_specific = {
|
|
.queue_xmit = ip_queue_xmit,
|
|
.send_check = tcp_v4_send_check,
|
|
.rebuild_header = tcp_v4_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 = v4_addr2sockaddr,
|
|
.sockaddr_len = sizeof(struct sockaddr_in),
|
|
};
|
|
|
|
/* 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 tcp_sock *tp = tcp_sk(sk);
|
|
|
|
skb_queue_head_init(&tp->out_of_order_queue);
|
|
tcp_init_xmit_timers(sk);
|
|
tcp_prequeue_init(tp);
|
|
|
|
tp->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_std = tp->mss_cache = 536;
|
|
|
|
tp->reordering = sysctl_tcp_reordering;
|
|
tp->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);
|
|
|
|
tp->af_specific = &ipv4_specific;
|
|
|
|
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(tp);
|
|
|
|
/* 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);
|
|
|
|
/* Clean prequeue, it must be empty really */
|
|
__skb_queue_purge(&tp->ucopy.prequeue);
|
|
|
|
/* Clean up a referenced TCP bind bucket. */
|
|
if (tp->bind_hash)
|
|
tcp_put_port(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 tcp_tw_bucket *tw_head(struct hlist_head *head)
|
|
{
|
|
return hlist_empty(head) ? NULL :
|
|
list_entry(head->first, struct tcp_tw_bucket, tw_node);
|
|
}
|
|
|
|
static inline struct tcp_tw_bucket *tw_next(struct tcp_tw_bucket *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 tcp_sock *tp;
|
|
struct hlist_node *node;
|
|
struct sock *sk = cur;
|
|
struct tcp_iter_state* st = seq->private;
|
|
|
|
if (!sk) {
|
|
st->bucket = 0;
|
|
sk = sk_head(&tcp_listening_hash[0]);
|
|
goto get_sk;
|
|
}
|
|
|
|
++st->num;
|
|
|
|
if (st->state == TCP_SEQ_STATE_OPENREQ) {
|
|
struct request_sock *req = cur;
|
|
|
|
tp = tcp_sk(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 >= TCP_SYNQ_HSIZE)
|
|
break;
|
|
get_req:
|
|
req = tp->accept_queue.listen_opt->syn_table[st->sbucket];
|
|
}
|
|
sk = sk_next(st->syn_wait_sk);
|
|
st->state = TCP_SEQ_STATE_LISTENING;
|
|
read_unlock_bh(&tp->accept_queue.syn_wait_lock);
|
|
} else {
|
|
tp = tcp_sk(sk);
|
|
read_lock_bh(&tp->accept_queue.syn_wait_lock);
|
|
if (reqsk_queue_len(&tp->accept_queue))
|
|
goto start_req;
|
|
read_unlock_bh(&tp->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;
|
|
}
|
|
tp = tcp_sk(sk);
|
|
read_lock_bh(&tp->accept_queue.syn_wait_lock);
|
|
if (reqsk_queue_len(&tp->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(&tp->accept_queue.syn_wait_lock);
|
|
}
|
|
if (++st->bucket < TCP_LHTABLE_SIZE) {
|
|
sk = sk_head(&tcp_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_ehash_size; ++st->bucket) {
|
|
struct sock *sk;
|
|
struct hlist_node *node;
|
|
struct tcp_tw_bucket *tw;
|
|
|
|
/* We can reschedule _before_ having picked the target: */
|
|
cond_resched_softirq();
|
|
|
|
read_lock(&tcp_ehash[st->bucket].lock);
|
|
sk_for_each(sk, node, &tcp_ehash[st->bucket].chain) {
|
|
if (sk->sk_family != st->family) {
|
|
continue;
|
|
}
|
|
rc = sk;
|
|
goto out;
|
|
}
|
|
st->state = TCP_SEQ_STATE_TIME_WAIT;
|
|
tw_for_each(tw, node,
|
|
&tcp_ehash[st->bucket + tcp_ehash_size].chain) {
|
|
if (tw->tw_family != st->family) {
|
|
continue;
|
|
}
|
|
rc = tw;
|
|
goto out;
|
|
}
|
|
read_unlock(&tcp_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 tcp_tw_bucket *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_ehash[st->bucket].lock);
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
|
|
/* We can reschedule between buckets: */
|
|
cond_resched_softirq();
|
|
|
|
if (++st->bucket < tcp_ehash_size) {
|
|
read_lock(&tcp_ehash[st->bucket].lock);
|
|
sk = sk_head(&tcp_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_ehash[st->bucket + tcp_ehash_size].chain);
|
|
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;
|
|
|
|
tcp_listen_lock();
|
|
st->state = TCP_SEQ_STATE_LISTENING;
|
|
rc = listening_get_idx(seq, &pos);
|
|
|
|
if (!rc) {
|
|
tcp_listen_unlock();
|
|
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) {
|
|
tcp_listen_unlock();
|
|
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 tcp_sock *tp = tcp_sk(st->syn_wait_sk);
|
|
read_unlock_bh(&tp->accept_queue.syn_wait_lock);
|
|
}
|
|
case TCP_SEQ_STATE_LISTENING:
|
|
if (v != SEQ_START_TOKEN)
|
|
tcp_listen_unlock();
|
|
break;
|
|
case TCP_SEQ_STATE_TIME_WAIT:
|
|
case TCP_SEQ_STATE_ESTABLISHED:
|
|
if (v)
|
|
read_unlock(&tcp_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 = kmalloc(sizeof(*s), GFP_KERNEL);
|
|
if (!s)
|
|
return -ENOMEM;
|
|
memset(s, 0, sizeof(*s));
|
|
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);
|
|
struct inet_sock *inet = inet_sk(sp);
|
|
unsigned int dest = inet->daddr;
|
|
unsigned int src = inet->rcv_saddr;
|
|
__u16 destp = ntohs(inet->dport);
|
|
__u16 srcp = ntohs(inet->sport);
|
|
|
|
if (tp->pending == TCP_TIME_RETRANS) {
|
|
timer_active = 1;
|
|
timer_expires = tp->timeout;
|
|
} else if (tp->pending == TCP_TIME_PROBE0) {
|
|
timer_active = 4;
|
|
timer_expires = tp->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, tp->rcv_nxt - tp->copied_seq,
|
|
timer_active,
|
|
jiffies_to_clock_t(timer_expires - jiffies),
|
|
tp->retransmits,
|
|
sock_i_uid(sp),
|
|
tp->probes_out,
|
|
sock_i_ino(sp),
|
|
atomic_read(&sp->sk_refcnt), sp,
|
|
tp->rto, tp->ack.ato, (tp->ack.quick << 1) | tp->ack.pingpong,
|
|
tp->snd_cwnd,
|
|
tp->snd_ssthresh >= 0xFFFF ? -1 : tp->snd_ssthresh);
|
|
}
|
|
|
|
static void get_timewait4_sock(struct tcp_tw_bucket *tw, char *tmpbuf, int i)
|
|
{
|
|
unsigned int 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 = tcp_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,
|
|
.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),
|
|
.rsk_prot = &tcp_request_sock_ops,
|
|
};
|
|
|
|
|
|
|
|
void __init tcp_v4_init(struct net_proto_family *ops)
|
|
{
|
|
int err = sock_create_kern(PF_INET, SOCK_RAW, IPPROTO_TCP, &tcp_socket);
|
|
if (err < 0)
|
|
panic("Failed to create the TCP control socket.\n");
|
|
tcp_socket->sk->sk_allocation = GFP_ATOMIC;
|
|
inet_sk(tcp_socket->sk)->uc_ttl = -1;
|
|
|
|
/* Unhash it so that IP input processing does not even
|
|
* see it, we do not wish this socket to see incoming
|
|
* packets.
|
|
*/
|
|
tcp_socket->sk->sk_prot->unhash(tcp_socket->sk);
|
|
}
|
|
|
|
EXPORT_SYMBOL(ipv4_specific);
|
|
EXPORT_SYMBOL(tcp_bind_hash);
|
|
EXPORT_SYMBOL(tcp_bucket_create);
|
|
EXPORT_SYMBOL(tcp_hashinfo);
|
|
EXPORT_SYMBOL(tcp_inherit_port);
|
|
EXPORT_SYMBOL(tcp_listen_wlock);
|
|
EXPORT_SYMBOL(tcp_port_rover);
|
|
EXPORT_SYMBOL(tcp_prot);
|
|
EXPORT_SYMBOL(tcp_put_port);
|
|
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_rebuild_header);
|
|
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);
|
|
EXPORT_SYMBOL(sysctl_tcp_tw_reuse);
|
|
|