2642 lines
66 KiB
C
2642 lines
66 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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* 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/bottom_half.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 <linux/slab.h>
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#include <net/net_namespace.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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EXPORT_SYMBOL(sysctl_tcp_low_latency);
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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_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
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__be32 daddr, __be32 saddr, struct tcphdr *th);
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#else
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static inline
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struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr)
|
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{
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return NULL;
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}
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#endif
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struct inet_hashinfo tcp_hashinfo;
|
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EXPORT_SYMBOL(tcp_hashinfo);
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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(ip_hdr(skb)->daddr,
|
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ip_hdr(skb)->saddr,
|
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tcp_hdr(skb)->dest,
|
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tcp_hdr(skb)->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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const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw);
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struct tcp_sock *tp = tcp_sk(sk);
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|
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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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|
|
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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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|
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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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get_seconds() - 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 sockaddr_in *usin = (struct sockaddr_in *)uaddr;
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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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__be16 orig_sport, orig_dport;
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__be32 daddr, nexthop;
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struct flowi4 *fl4;
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struct rtable *rt;
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int err;
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struct ip_options_rcu *inet_opt;
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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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inet_opt = rcu_dereference_protected(inet->inet_opt,
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sock_owned_by_user(sk));
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if (inet_opt && inet_opt->opt.srr) {
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if (!daddr)
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return -EINVAL;
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nexthop = inet_opt->opt.faddr;
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}
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orig_sport = inet->inet_sport;
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orig_dport = usin->sin_port;
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fl4 = &inet->cork.fl.u.ip4;
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rt = ip_route_connect(fl4, nexthop, inet->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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orig_sport, orig_dport, sk, true);
|
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if (IS_ERR(rt)) {
|
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err = PTR_ERR(rt);
|
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if (err == -ENETUNREACH)
|
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IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
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return err;
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|
}
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|
|
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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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|
|
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if (!inet_opt || !inet_opt->opt.srr)
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daddr = fl4->daddr;
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if (!inet->inet_saddr)
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inet->inet_saddr = fl4->saddr;
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inet->inet_rcv_saddr = inet->inet_saddr;
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|
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if (tp->rx_opt.ts_recent_stamp && inet->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 && fl4->daddr == 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) {
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inet_peer_refcheck(peer);
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if ((u32)get_seconds() - peer->tcp_ts_stamp <= TCP_PAWS_MSL) {
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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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}
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inet->inet_dport = usin->sin_port;
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inet->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->opt.optlen;
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tp->rx_opt.mss_clamp = TCP_MSS_DEFAULT;
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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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rt = ip_route_newports(fl4, rt, orig_sport, orig_dport,
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inet->inet_sport, inet->inet_dport, sk);
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if (IS_ERR(rt)) {
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err = PTR_ERR(rt);
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rt = NULL;
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goto failure;
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}
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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->dst);
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if (!tp->write_seq)
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tp->write_seq = secure_tcp_sequence_number(inet->inet_saddr,
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inet->inet_daddr,
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inet->inet_sport,
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usin->sin_port);
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|
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inet->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->inet_dport = 0;
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return err;
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}
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EXPORT_SYMBOL(tcp_v4_connect);
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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, const 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);
|
|
|
|
/* 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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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 &&
|
|
inet_csk(sk)->icsk_pmtu_cookie > mtu) {
|
|
tcp_sync_mss(sk, mtu);
|
|
|
|
/* Resend the TCP packet because it's
|
|
* clear that the old packet has been
|
|
* dropped. This is the new "fast" path mtu
|
|
* discovery.
|
|
*/
|
|
tcp_simple_retransmit(sk);
|
|
} /* else let the usual retransmit timer handle it */
|
|
}
|
|
|
|
/*
|
|
* This routine is called by the ICMP module when it gets some
|
|
* sort of error condition. If err < 0 then the socket should
|
|
* be closed and the error returned to the user. If err > 0
|
|
* it's just the icmp type << 8 | icmp code. After adjustment
|
|
* header points to the first 8 bytes of the tcp header. We need
|
|
* to find the appropriate port.
|
|
*
|
|
* The locking strategy used here is very "optimistic". When
|
|
* someone else accesses the socket the ICMP is just dropped
|
|
* and for some paths there is no check at all.
|
|
* A more general error queue to queue errors for later handling
|
|
* is probably better.
|
|
*
|
|
*/
|
|
|
|
void tcp_v4_err(struct sk_buff *icmp_skb, u32 info)
|
|
{
|
|
const struct iphdr *iph = (const struct iphdr *)icmp_skb->data;
|
|
struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2));
|
|
struct inet_connection_sock *icsk;
|
|
struct tcp_sock *tp;
|
|
struct inet_sock *inet;
|
|
const int type = icmp_hdr(icmp_skb)->type;
|
|
const int code = icmp_hdr(icmp_skb)->code;
|
|
struct sock *sk;
|
|
struct sk_buff *skb;
|
|
__u32 seq;
|
|
__u32 remaining;
|
|
int err;
|
|
struct net *net = dev_net(icmp_skb->dev);
|
|
|
|
if (icmp_skb->len < (iph->ihl << 2) + 8) {
|
|
ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
|
|
return;
|
|
}
|
|
|
|
sk = inet_lookup(net, &tcp_hashinfo, iph->daddr, th->dest,
|
|
iph->saddr, th->source, inet_iif(icmp_skb));
|
|
if (!sk) {
|
|
ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
|
|
return;
|
|
}
|
|
if (sk->sk_state == TCP_TIME_WAIT) {
|
|
inet_twsk_put(inet_twsk(sk));
|
|
return;
|
|
}
|
|
|
|
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(net, LINUX_MIB_LOCKDROPPEDICMPS);
|
|
|
|
if (sk->sk_state == TCP_CLOSE)
|
|
goto out;
|
|
|
|
if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
|
|
NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
|
|
goto out;
|
|
}
|
|
|
|
icsk = inet_csk(sk);
|
|
tp = tcp_sk(sk);
|
|
seq = ntohl(th->seq);
|
|
if (sk->sk_state != TCP_LISTEN &&
|
|
!between(seq, tp->snd_una, tp->snd_nxt)) {
|
|
NET_INC_STATS_BH(net, 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;
|
|
/* check if icmp_skb allows revert of backoff
|
|
* (see draft-zimmermann-tcp-lcd) */
|
|
if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH)
|
|
break;
|
|
if (seq != tp->snd_una || !icsk->icsk_retransmits ||
|
|
!icsk->icsk_backoff)
|
|
break;
|
|
|
|
if (sock_owned_by_user(sk))
|
|
break;
|
|
|
|
icsk->icsk_backoff--;
|
|
inet_csk(sk)->icsk_rto = __tcp_set_rto(tp) <<
|
|
icsk->icsk_backoff;
|
|
tcp_bound_rto(sk);
|
|
|
|
skb = tcp_write_queue_head(sk);
|
|
BUG_ON(!skb);
|
|
|
|
remaining = icsk->icsk_rto - min(icsk->icsk_rto,
|
|
tcp_time_stamp - TCP_SKB_CB(skb)->when);
|
|
|
|
if (remaining) {
|
|
inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
|
|
remaining, TCP_RTO_MAX);
|
|
} else {
|
|
/* RTO revert clocked out retransmission.
|
|
* Will retransmit now */
|
|
tcp_retransmit_timer(sk);
|
|
}
|
|
|
|
break;
|
|
case ICMP_TIME_EXCEEDED:
|
|
err = EHOSTUNREACH;
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
|
|
switch (sk->sk_state) {
|
|
struct request_sock *req, **prev;
|
|
case TCP_LISTEN:
|
|
if (sock_owned_by_user(sk))
|
|
goto out;
|
|
|
|
req = inet_csk_search_req(sk, &prev, th->dest,
|
|
iph->daddr, iph->saddr);
|
|
if (!req)
|
|
goto out;
|
|
|
|
/* ICMPs are not backlogged, hence we cannot get
|
|
an established socket here.
|
|
*/
|
|
WARN_ON(req->sk);
|
|
|
|
if (seq != tcp_rsk(req)->snt_isn) {
|
|
NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
|
|
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);
|
|
}
|
|
|
|
static void __tcp_v4_send_check(struct sk_buff *skb,
|
|
__be32 saddr, __be32 daddr)
|
|
{
|
|
struct tcphdr *th = tcp_hdr(skb);
|
|
|
|
if (skb->ip_summed == CHECKSUM_PARTIAL) {
|
|
th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0);
|
|
skb->csum_start = skb_transport_header(skb) - skb->head;
|
|
skb->csum_offset = offsetof(struct tcphdr, check);
|
|
} else {
|
|
th->check = tcp_v4_check(skb->len, saddr, daddr,
|
|
csum_partial(th,
|
|
th->doff << 2,
|
|
skb->csum));
|
|
}
|
|
}
|
|
|
|
/* This routine computes an IPv4 TCP checksum. */
|
|
void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
|
|
__tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr);
|
|
}
|
|
EXPORT_SYMBOL(tcp_v4_send_check);
|
|
|
|
int tcp_v4_gso_send_check(struct sk_buff *skb)
|
|
{
|
|
const struct iphdr *iph;
|
|
struct tcphdr *th;
|
|
|
|
if (!pskb_may_pull(skb, sizeof(*th)))
|
|
return -EINVAL;
|
|
|
|
iph = ip_hdr(skb);
|
|
th = tcp_hdr(skb);
|
|
|
|
th->check = 0;
|
|
skb->ip_summed = CHECKSUM_PARTIAL;
|
|
__tcp_v4_send_check(skb, iph->saddr, iph->daddr);
|
|
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 = tcp_hdr(skb);
|
|
struct {
|
|
struct tcphdr th;
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
__be32 opt[(TCPOLEN_MD5SIG_ALIGNED >> 2)];
|
|
#endif
|
|
} rep;
|
|
struct ip_reply_arg arg;
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
struct tcp_md5sig_key *key;
|
|
#endif
|
|
struct net *net;
|
|
|
|
/* Never send a reset in response to a reset. */
|
|
if (th->rst)
|
|
return;
|
|
|
|
if (skb_rtable(skb)->rt_type != RTN_LOCAL)
|
|
return;
|
|
|
|
/* Swap the send and the receive. */
|
|
memset(&rep, 0, sizeof(rep));
|
|
rep.th.dest = th->source;
|
|
rep.th.source = th->dest;
|
|
rep.th.doff = sizeof(struct tcphdr) / 4;
|
|
rep.th.rst = 1;
|
|
|
|
if (th->ack) {
|
|
rep.th.seq = th->ack_seq;
|
|
} else {
|
|
rep.th.ack = 1;
|
|
rep.th.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin +
|
|
skb->len - (th->doff << 2));
|
|
}
|
|
|
|
memset(&arg, 0, sizeof(arg));
|
|
arg.iov[0].iov_base = (unsigned char *)&rep;
|
|
arg.iov[0].iov_len = sizeof(rep.th);
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
key = sk ? tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->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_md5_hash_hdr((__u8 *) &rep.opt[1],
|
|
key, ip_hdr(skb)->saddr,
|
|
ip_hdr(skb)->daddr, &rep.th);
|
|
}
|
|
#endif
|
|
arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
|
|
ip_hdr(skb)->saddr, /* XXX */
|
|
arg.iov[0].iov_len, IPPROTO_TCP, 0);
|
|
arg.csumoffset = offsetof(struct tcphdr, check) / 2;
|
|
arg.flags = (sk && inet_sk(sk)->transparent) ? IP_REPLY_ARG_NOSRCCHECK : 0;
|
|
|
|
net = dev_net(skb_dst(skb)->dev);
|
|
ip_send_reply(net->ipv4.tcp_sock, skb,
|
|
&arg, arg.iov[0].iov_len);
|
|
|
|
TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
|
|
TCP_INC_STATS_BH(net, 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, int oif,
|
|
struct tcp_md5sig_key *key,
|
|
int reply_flags)
|
|
{
|
|
struct tcphdr *th = tcp_hdr(skb);
|
|
struct {
|
|
struct tcphdr th;
|
|
__be32 opt[(TCPOLEN_TSTAMP_ALIGNED >> 2)
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
+ (TCPOLEN_MD5SIG_ALIGNED >> 2)
|
|
#endif
|
|
];
|
|
} rep;
|
|
struct ip_reply_arg arg;
|
|
struct net *net = dev_net(skb_dst(skb)->dev);
|
|
|
|
memset(&rep.th, 0, sizeof(struct tcphdr));
|
|
memset(&arg, 0, sizeof(arg));
|
|
|
|
arg.iov[0].iov_base = (unsigned char *)&rep;
|
|
arg.iov[0].iov_len = sizeof(rep.th);
|
|
if (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
|
|
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_md5_hash_hdr((__u8 *) &rep.opt[offset],
|
|
key, ip_hdr(skb)->saddr,
|
|
ip_hdr(skb)->daddr, &rep.th);
|
|
}
|
|
#endif
|
|
arg.flags = reply_flags;
|
|
arg.csum = csum_tcpudp_nofold(ip_hdr(skb)->daddr,
|
|
ip_hdr(skb)->saddr, /* XXX */
|
|
arg.iov[0].iov_len, IPPROTO_TCP, 0);
|
|
arg.csumoffset = offsetof(struct tcphdr, check) / 2;
|
|
if (oif)
|
|
arg.bound_dev_if = oif;
|
|
|
|
ip_send_reply(net->ipv4.tcp_sock, skb,
|
|
&arg, arg.iov[0].iov_len);
|
|
|
|
TCP_INC_STATS_BH(net, TCP_MIB_OUTSEGS);
|
|
}
|
|
|
|
static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct inet_timewait_sock *tw = inet_twsk(sk);
|
|
struct tcp_timewait_sock *tcptw = tcp_twsk(sk);
|
|
|
|
tcp_v4_send_ack(skb, tcptw->tw_snd_nxt, tcptw->tw_rcv_nxt,
|
|
tcptw->tw_rcv_wnd >> tw->tw_rcv_wscale,
|
|
tcptw->tw_ts_recent,
|
|
tw->tw_bound_dev_if,
|
|
tcp_twsk_md5_key(tcptw),
|
|
tw->tw_transparent ? IP_REPLY_ARG_NOSRCCHECK : 0
|
|
);
|
|
|
|
inet_twsk_put(tw);
|
|
}
|
|
|
|
static void tcp_v4_reqsk_send_ack(struct sock *sk, 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,
|
|
0,
|
|
tcp_v4_md5_do_lookup(sk, ip_hdr(skb)->daddr),
|
|
inet_rsk(req)->no_srccheck ? IP_REPLY_ARG_NOSRCCHECK : 0);
|
|
}
|
|
|
|
/*
|
|
* Send a SYN-ACK after having received a SYN.
|
|
* This still operates on a request_sock only, not on a big
|
|
* socket.
|
|
*/
|
|
static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
|
|
struct request_sock *req,
|
|
struct request_values *rvp)
|
|
{
|
|
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)
|
|
return -1;
|
|
|
|
skb = tcp_make_synack(sk, dst, req, rvp);
|
|
|
|
if (skb) {
|
|
__tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr);
|
|
|
|
err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
|
|
ireq->rmt_addr,
|
|
ireq->opt);
|
|
err = net_xmit_eval(err);
|
|
}
|
|
|
|
dst_release(dst);
|
|
return err;
|
|
}
|
|
|
|
static int tcp_v4_rtx_synack(struct sock *sk, struct request_sock *req,
|
|
struct request_values *rvp)
|
|
{
|
|
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_RETRANSSEGS);
|
|
return tcp_v4_send_synack(sk, NULL, req, rvp);
|
|
}
|
|
|
|
/*
|
|
* IPv4 request_sock destructor.
|
|
*/
|
|
static void tcp_v4_reqsk_destructor(struct request_sock *req)
|
|
{
|
|
kfree(inet_rsk(req)->opt);
|
|
}
|
|
|
|
static void syn_flood_warning(const struct sk_buff *skb)
|
|
{
|
|
const char *msg;
|
|
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
if (sysctl_tcp_syncookies)
|
|
msg = "Sending cookies";
|
|
else
|
|
#endif
|
|
msg = "Dropping request";
|
|
|
|
pr_info("TCP: Possible SYN flooding on port %d. %s.\n",
|
|
ntohs(tcp_hdr(skb)->dest), msg);
|
|
}
|
|
|
|
/*
|
|
* Save and compile IPv4 options into the request_sock if needed.
|
|
*/
|
|
static struct ip_options_rcu *tcp_v4_save_options(struct sock *sk,
|
|
struct sk_buff *skb)
|
|
{
|
|
const struct ip_options *opt = &(IPCB(skb)->opt);
|
|
struct ip_options_rcu *dopt = NULL;
|
|
|
|
if (opt && opt->optlen) {
|
|
int opt_size = sizeof(*dopt) + opt->optlen;
|
|
|
|
dopt = kmalloc(opt_size, GFP_ATOMIC);
|
|
if (dopt) {
|
|
if (ip_options_echo(&dopt->opt, 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 &tp->md5sig_info->keys4[i].base;
|
|
}
|
|
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)->inet_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 tcp_md5sig_key *key;
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct tcp4_md5sig_key *keys;
|
|
|
|
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;
|
|
}
|
|
sk_nocaps_add(sk, NETIF_F_GSO_MASK);
|
|
}
|
|
if (tcp_alloc_md5sig_pool(sk) == 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 */
|
|
kfree(md5sig->keys4);
|
|
md5sig->keys4 = keys;
|
|
md5sig->alloced4++;
|
|
}
|
|
md5sig->entries4++;
|
|
md5sig->keys4[md5sig->entries4 - 1].addr = addr;
|
|
md5sig->keys4[md5sig->entries4 - 1].base.key = newkey;
|
|
md5sig->keys4[md5sig->entries4 - 1].base.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)->inet_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].base.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 */
|
|
memmove(&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].base.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;
|
|
|
|
p = kzalloc(sizeof(*p), sk->sk_allocation);
|
|
if (!p)
|
|
return -EINVAL;
|
|
|
|
tp->md5sig_info = p;
|
|
sk_nocaps_add(sk, NETIF_F_GSO_MASK);
|
|
}
|
|
|
|
newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, sk->sk_allocation);
|
|
if (!newkey)
|
|
return -ENOMEM;
|
|
return tcp_v4_md5_do_add(sk, sin->sin_addr.s_addr,
|
|
newkey, cmd.tcpm_keylen);
|
|
}
|
|
|
|
static int tcp_v4_md5_hash_pseudoheader(struct tcp_md5sig_pool *hp,
|
|
__be32 daddr, __be32 saddr, int nbytes)
|
|
{
|
|
struct tcp4_pseudohdr *bp;
|
|
struct scatterlist sg;
|
|
|
|
bp = &hp->md5_blk.ip4;
|
|
|
|
/*
|
|
* 1. the TCP pseudo-header (in the order: source IP address,
|
|
* destination IP address, zero-padded protocol number, and
|
|
* segment length)
|
|
*/
|
|
bp->saddr = saddr;
|
|
bp->daddr = daddr;
|
|
bp->pad = 0;
|
|
bp->protocol = IPPROTO_TCP;
|
|
bp->len = cpu_to_be16(nbytes);
|
|
|
|
sg_init_one(&sg, bp, sizeof(*bp));
|
|
return crypto_hash_update(&hp->md5_desc, &sg, sizeof(*bp));
|
|
}
|
|
|
|
static int tcp_v4_md5_hash_hdr(char *md5_hash, struct tcp_md5sig_key *key,
|
|
__be32 daddr, __be32 saddr, struct tcphdr *th)
|
|
{
|
|
struct tcp_md5sig_pool *hp;
|
|
struct hash_desc *desc;
|
|
|
|
hp = tcp_get_md5sig_pool();
|
|
if (!hp)
|
|
goto clear_hash_noput;
|
|
desc = &hp->md5_desc;
|
|
|
|
if (crypto_hash_init(desc))
|
|
goto clear_hash;
|
|
if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, th->doff << 2))
|
|
goto clear_hash;
|
|
if (tcp_md5_hash_header(hp, th))
|
|
goto clear_hash;
|
|
if (tcp_md5_hash_key(hp, key))
|
|
goto clear_hash;
|
|
if (crypto_hash_final(desc, md5_hash))
|
|
goto clear_hash;
|
|
|
|
tcp_put_md5sig_pool();
|
|
return 0;
|
|
|
|
clear_hash:
|
|
tcp_put_md5sig_pool();
|
|
clear_hash_noput:
|
|
memset(md5_hash, 0, 16);
|
|
return 1;
|
|
}
|
|
|
|
int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
|
|
struct sock *sk, struct request_sock *req,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct tcp_md5sig_pool *hp;
|
|
struct hash_desc *desc;
|
|
struct tcphdr *th = tcp_hdr(skb);
|
|
__be32 saddr, daddr;
|
|
|
|
if (sk) {
|
|
saddr = inet_sk(sk)->inet_saddr;
|
|
daddr = inet_sk(sk)->inet_daddr;
|
|
} else if (req) {
|
|
saddr = inet_rsk(req)->loc_addr;
|
|
daddr = inet_rsk(req)->rmt_addr;
|
|
} else {
|
|
const struct iphdr *iph = ip_hdr(skb);
|
|
saddr = iph->saddr;
|
|
daddr = iph->daddr;
|
|
}
|
|
|
|
hp = tcp_get_md5sig_pool();
|
|
if (!hp)
|
|
goto clear_hash_noput;
|
|
desc = &hp->md5_desc;
|
|
|
|
if (crypto_hash_init(desc))
|
|
goto clear_hash;
|
|
|
|
if (tcp_v4_md5_hash_pseudoheader(hp, daddr, saddr, skb->len))
|
|
goto clear_hash;
|
|
if (tcp_md5_hash_header(hp, th))
|
|
goto clear_hash;
|
|
if (tcp_md5_hash_skb_data(hp, skb, th->doff << 2))
|
|
goto clear_hash;
|
|
if (tcp_md5_hash_key(hp, key))
|
|
goto clear_hash;
|
|
if (crypto_hash_final(desc, md5_hash))
|
|
goto clear_hash;
|
|
|
|
tcp_put_md5sig_pool();
|
|
return 0;
|
|
|
|
clear_hash:
|
|
tcp_put_md5sig_pool();
|
|
clear_hash_noput:
|
|
memset(md5_hash, 0, 16);
|
|
return 1;
|
|
}
|
|
EXPORT_SYMBOL(tcp_v4_md5_hash_skb);
|
|
|
|
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;
|
|
const struct iphdr *iph = ip_hdr(skb);
|
|
struct tcphdr *th = tcp_hdr(skb);
|
|
int genhash;
|
|
unsigned char newhash[16];
|
|
|
|
hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
|
|
hash_location = tcp_parse_md5sig_option(th);
|
|
|
|
/* We've parsed the options - do we have a hash? */
|
|
if (!hash_expected && !hash_location)
|
|
return 0;
|
|
|
|
if (hash_expected && !hash_location) {
|
|
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
|
|
return 1;
|
|
}
|
|
|
|
if (!hash_expected && hash_location) {
|
|
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
|
|
return 1;
|
|
}
|
|
|
|
/* Okay, so this is hash_expected and hash_location -
|
|
* so we need to calculate the checksum.
|
|
*/
|
|
genhash = tcp_v4_md5_hash_skb(newhash,
|
|
hash_expected,
|
|
NULL, NULL, skb);
|
|
|
|
if (genhash || memcmp(hash_location, newhash, 16) != 0) {
|
|
if (net_ratelimit()) {
|
|
printk(KERN_INFO "MD5 Hash failed for (%pI4, %d)->(%pI4, %d)%s\n",
|
|
&iph->saddr, ntohs(th->source),
|
|
&iph->daddr, ntohs(th->dest),
|
|
genhash ? " tcp_v4_calc_md5_hash failed" : "");
|
|
}
|
|
return 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_rtx_synack,
|
|
.send_ack = tcp_v4_reqsk_send_ack,
|
|
.destructor = tcp_v4_reqsk_destructor,
|
|
.send_reset = tcp_v4_send_reset,
|
|
.syn_ack_timeout = tcp_syn_ack_timeout,
|
|
};
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
static const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops = {
|
|
.md5_lookup = tcp_v4_reqsk_md5_lookup,
|
|
.calc_md5_hash = tcp_v4_md5_hash_skb,
|
|
};
|
|
#endif
|
|
|
|
int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct tcp_extend_values tmp_ext;
|
|
struct tcp_options_received tmp_opt;
|
|
u8 *hash_location;
|
|
struct request_sock *req;
|
|
struct inet_request_sock *ireq;
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
struct dst_entry *dst = NULL;
|
|
__be32 saddr = ip_hdr(skb)->saddr;
|
|
__be32 daddr = ip_hdr(skb)->daddr;
|
|
__u32 isn = TCP_SKB_CB(skb)->when;
|
|
#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 (skb_rtable(skb)->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) {
|
|
if (net_ratelimit())
|
|
syn_flood_warning(skb);
|
|
#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 = inet_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 = TCP_MSS_DEFAULT;
|
|
tmp_opt.user_mss = tp->rx_opt.user_mss;
|
|
tcp_parse_options(skb, &tmp_opt, &hash_location, 0);
|
|
|
|
if (tmp_opt.cookie_plus > 0 &&
|
|
tmp_opt.saw_tstamp &&
|
|
!tp->rx_opt.cookie_out_never &&
|
|
(sysctl_tcp_cookie_size > 0 ||
|
|
(tp->cookie_values != NULL &&
|
|
tp->cookie_values->cookie_desired > 0))) {
|
|
u8 *c;
|
|
u32 *mess = &tmp_ext.cookie_bakery[COOKIE_DIGEST_WORDS];
|
|
int l = tmp_opt.cookie_plus - TCPOLEN_COOKIE_BASE;
|
|
|
|
if (tcp_cookie_generator(&tmp_ext.cookie_bakery[0]) != 0)
|
|
goto drop_and_release;
|
|
|
|
/* Secret recipe starts with IP addresses */
|
|
*mess++ ^= (__force u32)daddr;
|
|
*mess++ ^= (__force u32)saddr;
|
|
|
|
/* plus variable length Initiator Cookie */
|
|
c = (u8 *)mess;
|
|
while (l-- > 0)
|
|
*c++ ^= *hash_location++;
|
|
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
want_cookie = 0; /* not our kind of cookie */
|
|
#endif
|
|
tmp_ext.cookie_out_never = 0; /* false */
|
|
tmp_ext.cookie_plus = tmp_opt.cookie_plus;
|
|
} else if (!tp->rx_opt.cookie_in_always) {
|
|
/* redundant indications, but ensure initialization. */
|
|
tmp_ext.cookie_out_never = 1; /* true */
|
|
tmp_ext.cookie_plus = 0;
|
|
} else {
|
|
goto drop_and_release;
|
|
}
|
|
tmp_ext.cookie_in_always = tp->rx_opt.cookie_in_always;
|
|
|
|
if (want_cookie && !tmp_opt.saw_tstamp)
|
|
tcp_clear_options(&tmp_opt);
|
|
|
|
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->no_srccheck = inet_sk(sk)->transparent;
|
|
ireq->opt = tcp_v4_save_options(sk, skb);
|
|
|
|
if (security_inet_conn_request(sk, skb, req))
|
|
goto drop_and_free;
|
|
|
|
if (!want_cookie || tmp_opt.tstamp_ok)
|
|
TCP_ECN_create_request(req, tcp_hdr(skb));
|
|
|
|
if (want_cookie) {
|
|
isn = cookie_v4_init_sequence(sk, skb, &req->mss);
|
|
req->cookie_ts = tmp_opt.tstamp_ok;
|
|
} 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->daddr.addr.a4 == saddr) {
|
|
inet_peer_refcheck(peer);
|
|
if ((u32)get_seconds() - peer->tcp_ts_stamp < TCP_PAWS_MSL &&
|
|
(s32)(peer->tcp_ts - req->ts_recent) >
|
|
TCP_PAWS_WINDOW) {
|
|
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_PAWSPASSIVEREJECTED);
|
|
goto drop_and_release;
|
|
}
|
|
}
|
|
/* 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 %pI4/%u\n",
|
|
&saddr, ntohs(tcp_hdr(skb)->source));
|
|
goto drop_and_release;
|
|
}
|
|
|
|
isn = tcp_v4_init_sequence(skb);
|
|
}
|
|
tcp_rsk(req)->snt_isn = isn;
|
|
|
|
if (tcp_v4_send_synack(sk, dst, req,
|
|
(struct request_values *)&tmp_ext) ||
|
|
want_cookie)
|
|
goto drop_and_free;
|
|
|
|
inet_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
|
|
return 0;
|
|
|
|
drop_and_release:
|
|
dst_release(dst);
|
|
drop_and_free:
|
|
reqsk_free(req);
|
|
drop:
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(tcp_v4_conn_request);
|
|
|
|
|
|
/*
|
|
* The three way handshake has completed - we got a valid synack -
|
|
* now create the new socket.
|
|
*/
|
|
struct sock *tcp_v4_syn_recv_sock(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
|
|
struct ip_options_rcu *inet_opt;
|
|
|
|
if (sk_acceptq_is_full(sk))
|
|
goto exit_overflow;
|
|
|
|
newsk = tcp_create_openreq_child(sk, req, skb);
|
|
if (!newsk)
|
|
goto exit_nonewsk;
|
|
|
|
newsk->sk_gso_type = SKB_GSO_TCPV4;
|
|
|
|
newtp = tcp_sk(newsk);
|
|
newinet = inet_sk(newsk);
|
|
ireq = inet_rsk(req);
|
|
newinet->inet_daddr = ireq->rmt_addr;
|
|
newinet->inet_rcv_saddr = ireq->loc_addr;
|
|
newinet->inet_saddr = ireq->loc_addr;
|
|
inet_opt = ireq->opt;
|
|
rcu_assign_pointer(newinet->inet_opt, inet_opt);
|
|
ireq->opt = NULL;
|
|
newinet->mc_index = inet_iif(skb);
|
|
newinet->mc_ttl = ip_hdr(skb)->ttl;
|
|
inet_csk(newsk)->icsk_ext_hdr_len = 0;
|
|
if (inet_opt)
|
|
inet_csk(newsk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
|
|
newinet->inet_id = newtp->write_seq ^ jiffies;
|
|
|
|
if (!dst && (dst = inet_csk_route_child_sock(sk, newsk, req)) == NULL)
|
|
goto put_and_exit;
|
|
|
|
sk_setup_caps(newsk, dst);
|
|
|
|
tcp_mtup_init(newsk);
|
|
tcp_sync_mss(newsk, dst_mtu(dst));
|
|
newtp->advmss = dst_metric_advmss(dst);
|
|
if (tcp_sk(sk)->rx_opt.user_mss &&
|
|
tcp_sk(sk)->rx_opt.user_mss < newtp->advmss)
|
|
newtp->advmss = tcp_sk(sk)->rx_opt.user_mss;
|
|
|
|
tcp_initialize_rcv_mss(newsk);
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
/* Copy over the MD5 key from the original socket */
|
|
key = tcp_v4_md5_do_lookup(sk, newinet->inet_daddr);
|
|
if (key != 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, newinet->inet_daddr,
|
|
newkey, key->keylen);
|
|
sk_nocaps_add(newsk, NETIF_F_GSO_MASK);
|
|
}
|
|
#endif
|
|
|
|
if (__inet_inherit_port(sk, newsk) < 0)
|
|
goto put_and_exit;
|
|
__inet_hash_nolisten(newsk, NULL);
|
|
|
|
return newsk;
|
|
|
|
exit_overflow:
|
|
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
|
|
exit_nonewsk:
|
|
dst_release(dst);
|
|
exit:
|
|
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_LISTENDROPS);
|
|
return NULL;
|
|
put_and_exit:
|
|
sock_put(newsk);
|
|
goto exit;
|
|
}
|
|
EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
|
|
|
|
static struct sock *tcp_v4_hnd_req(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct tcphdr *th = tcp_hdr(skb);
|
|
const struct iphdr *iph = ip_hdr(skb);
|
|
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(sock_net(sk), &tcp_hashinfo, iph->saddr,
|
|
th->source, 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->syn)
|
|
sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
|
|
#endif
|
|
return sk;
|
|
}
|
|
|
|
static __sum16 tcp_v4_checksum_init(struct sk_buff *skb)
|
|
{
|
|
const struct iphdr *iph = ip_hdr(skb);
|
|
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE) {
|
|
if (!tcp_v4_check(skb->len, iph->saddr,
|
|
iph->daddr, skb->csum)) {
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
skb->csum = csum_tcpudp_nofold(iph->saddr, 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 */
|
|
sock_rps_save_rxhash(sk, skb->rxhash);
|
|
if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
|
|
rsk = sk;
|
|
goto reset;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
if (skb->len < tcp_hdrlen(skb) || 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;
|
|
}
|
|
} else
|
|
sock_rps_save_rxhash(sk, skb->rxhash);
|
|
|
|
if (tcp_rcv_state_process(sk, skb, tcp_hdr(skb), skb->len)) {
|
|
rsk = sk;
|
|
goto reset;
|
|
}
|
|
return 0;
|
|
|
|
reset:
|
|
tcp_v4_send_reset(rsk, skb);
|
|
discard:
|
|
kfree_skb(skb);
|
|
/* Be careful here. If this function gets more complicated and
|
|
* gcc suffers from register pressure on the x86, sk (in %ebx)
|
|
* might be destroyed here. This current version compiles correctly,
|
|
* but you have been warned.
|
|
*/
|
|
return 0;
|
|
|
|
csum_err:
|
|
TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
|
|
goto discard;
|
|
}
|
|
EXPORT_SYMBOL(tcp_v4_do_rcv);
|
|
|
|
/*
|
|
* From tcp_input.c
|
|
*/
|
|
|
|
int tcp_v4_rcv(struct sk_buff *skb)
|
|
{
|
|
const struct iphdr *iph;
|
|
struct tcphdr *th;
|
|
struct sock *sk;
|
|
int ret;
|
|
struct net *net = dev_net(skb->dev);
|
|
|
|
if (skb->pkt_type != PACKET_HOST)
|
|
goto discard_it;
|
|
|
|
/* Count it even if it's bad */
|
|
TCP_INC_STATS_BH(net, TCP_MIB_INSEGS);
|
|
|
|
if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
|
|
goto discard_it;
|
|
|
|
th = tcp_hdr(skb);
|
|
|
|
if (th->doff < sizeof(struct tcphdr) / 4)
|
|
goto bad_packet;
|
|
if (!pskb_may_pull(skb, th->doff * 4))
|
|
goto discard_it;
|
|
|
|
/* An explanation is required here, I think.
|
|
* Packet length and doff are validated by header prediction,
|
|
* provided case of th->doff==0 is eliminated.
|
|
* So, we defer the checks. */
|
|
if (!skb_csum_unnecessary(skb) && tcp_v4_checksum_init(skb))
|
|
goto bad_packet;
|
|
|
|
th = tcp_hdr(skb);
|
|
iph = ip_hdr(skb);
|
|
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 = iph->tos;
|
|
TCP_SKB_CB(skb)->sacked = 0;
|
|
|
|
sk = __inet_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest);
|
|
if (!sk)
|
|
goto no_tcp_socket;
|
|
|
|
process:
|
|
if (sk->sk_state == TCP_TIME_WAIT)
|
|
goto do_time_wait;
|
|
|
|
if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) {
|
|
NET_INC_STATS_BH(net, LINUX_MIB_TCPMINTTLDROP);
|
|
goto discard_and_relse;
|
|
}
|
|
|
|
if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
|
|
goto discard_and_relse;
|
|
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 = dma_find_channel(DMA_MEMCPY);
|
|
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 if (unlikely(sk_add_backlog(sk, skb))) {
|
|
bh_unlock_sock(sk);
|
|
NET_INC_STATS_BH(net, LINUX_MIB_TCPBACKLOGDROP);
|
|
goto discard_and_relse;
|
|
}
|
|
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(net, TCP_MIB_INERRS);
|
|
} else {
|
|
tcp_v4_send_reset(NULL, skb);
|
|
}
|
|
|
|
discard_it:
|
|
/* Discard frame. */
|
|
kfree_skb(skb);
|
|
return 0;
|
|
|
|
discard_and_relse:
|
|
sock_put(sk);
|
|
goto discard_it;
|
|
|
|
do_time_wait:
|
|
if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
|
|
inet_twsk_put(inet_twsk(sk));
|
|
goto discard_it;
|
|
}
|
|
|
|
if (skb->len < (th->doff << 2) || tcp_checksum_complete(skb)) {
|
|
TCP_INC_STATS_BH(net, 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(dev_net(skb->dev),
|
|
&tcp_hashinfo,
|
|
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;
|
|
}
|
|
|
|
struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it)
|
|
{
|
|
struct rtable *rt = (struct rtable *) __sk_dst_get(sk);
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
struct inet_peer *peer;
|
|
|
|
if (!rt ||
|
|
inet->cork.fl.u.ip4.daddr != inet->inet_daddr) {
|
|
peer = inet_getpeer_v4(inet->inet_daddr, 1);
|
|
*release_it = true;
|
|
} else {
|
|
if (!rt->peer)
|
|
rt_bind_peer(rt, 1);
|
|
peer = rt->peer;
|
|
*release_it = false;
|
|
}
|
|
|
|
return peer;
|
|
}
|
|
EXPORT_SYMBOL(tcp_v4_get_peer);
|
|
|
|
void *tcp_v4_tw_get_peer(struct sock *sk)
|
|
{
|
|
struct inet_timewait_sock *tw = inet_twsk(sk);
|
|
|
|
return inet_getpeer_v4(tw->tw_daddr, 1);
|
|
}
|
|
EXPORT_SYMBOL(tcp_v4_tw_get_peer);
|
|
|
|
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,
|
|
.twsk_getpeer = tcp_v4_tw_get_peer,
|
|
};
|
|
|
|
const struct inet_connection_sock_af_ops ipv4_specific = {
|
|
.queue_xmit = ip_queue_xmit,
|
|
.send_check = tcp_v4_send_check,
|
|
.rebuild_header = inet_sk_rebuild_header,
|
|
.conn_request = tcp_v4_conn_request,
|
|
.syn_recv_sock = tcp_v4_syn_recv_sock,
|
|
.get_peer = tcp_v4_get_peer,
|
|
.net_header_len = sizeof(struct iphdr),
|
|
.setsockopt = ip_setsockopt,
|
|
.getsockopt = ip_getsockopt,
|
|
.addr2sockaddr = inet_csk_addr2sockaddr,
|
|
.sockaddr_len = sizeof(struct sockaddr_in),
|
|
.bind_conflict = inet_csk_bind_conflict,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_setsockopt = compat_ip_setsockopt,
|
|
.compat_getsockopt = compat_ip_getsockopt,
|
|
#endif
|
|
};
|
|
EXPORT_SYMBOL(ipv4_specific);
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
static const struct tcp_sock_af_ops tcp_sock_ipv4_specific = {
|
|
.md5_lookup = tcp_v4_md5_lookup,
|
|
.calc_md5_hash = tcp_v4_md5_hash_skb,
|
|
.md5_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 = TCP_INFINITE_SSTHRESH;
|
|
tp->snd_cwnd_clamp = ~0;
|
|
tp->mss_cache = TCP_MSS_DEFAULT;
|
|
|
|
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
|
|
|
|
/* TCP Cookie Transactions */
|
|
if (sysctl_tcp_cookie_size > 0) {
|
|
/* Default, cookies without s_data_payload. */
|
|
tp->cookie_values =
|
|
kzalloc(sizeof(*tp->cookie_values),
|
|
sk->sk_allocation);
|
|
if (tp->cookie_values != NULL)
|
|
kref_init(&tp->cookie_values->kref);
|
|
}
|
|
/* Presumed zeroed, in order of appearance:
|
|
* cookie_in_always, cookie_out_never,
|
|
* s_data_constant, s_data_in, s_data_out
|
|
*/
|
|
sk->sk_sndbuf = sysctl_tcp_wmem[1];
|
|
sk->sk_rcvbuf = sysctl_tcp_rmem[1];
|
|
|
|
local_bh_disable();
|
|
percpu_counter_inc(&tcp_sockets_allocated);
|
|
local_bh_enable();
|
|
|
|
return 0;
|
|
}
|
|
|
|
void tcp_v4_destroy_sock(struct sock *sk)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
tcp_clear_xmit_timers(sk);
|
|
|
|
tcp_cleanup_congestion_control(sk);
|
|
|
|
/* Cleanup up the write buffer. */
|
|
tcp_write_queue_purge(sk);
|
|
|
|
/* Cleans up our, hopefully empty, out_of_order_queue. */
|
|
__skb_queue_purge(&tp->out_of_order_queue);
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
/* Clean up the MD5 key list, if any */
|
|
if (tp->md5sig_info) {
|
|
tcp_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(sk);
|
|
|
|
/*
|
|
* If sendmsg cached page exists, toss it.
|
|
*/
|
|
if (sk->sk_sndmsg_page) {
|
|
__free_page(sk->sk_sndmsg_page);
|
|
sk->sk_sndmsg_page = NULL;
|
|
}
|
|
|
|
/* TCP Cookie Transactions */
|
|
if (tp->cookie_values != NULL) {
|
|
kref_put(&tp->cookie_values->kref,
|
|
tcp_cookie_values_release);
|
|
tp->cookie_values = NULL;
|
|
}
|
|
|
|
percpu_counter_dec(&tcp_sockets_allocated);
|
|
}
|
|
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_nulls_head *head)
|
|
{
|
|
return hlist_nulls_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 !is_a_nulls(tw->tw_node.next) ?
|
|
hlist_nulls_entry(tw->tw_node.next, typeof(*tw), tw_node) : NULL;
|
|
}
|
|
|
|
/*
|
|
* Get next listener socket follow cur. If cur is NULL, get first socket
|
|
* starting from bucket given in st->bucket; when st->bucket is zero the
|
|
* very first socket in the hash table is returned.
|
|
*/
|
|
static void *listening_get_next(struct seq_file *seq, void *cur)
|
|
{
|
|
struct inet_connection_sock *icsk;
|
|
struct hlist_nulls_node *node;
|
|
struct sock *sk = cur;
|
|
struct inet_listen_hashbucket *ilb;
|
|
struct tcp_iter_state *st = seq->private;
|
|
struct net *net = seq_file_net(seq);
|
|
|
|
if (!sk) {
|
|
ilb = &tcp_hashinfo.listening_hash[st->bucket];
|
|
spin_lock_bh(&ilb->lock);
|
|
sk = sk_nulls_head(&ilb->head);
|
|
st->offset = 0;
|
|
goto get_sk;
|
|
}
|
|
ilb = &tcp_hashinfo.listening_hash[st->bucket];
|
|
++st->num;
|
|
++st->offset;
|
|
|
|
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_nulls_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_nulls_next(sk);
|
|
}
|
|
get_sk:
|
|
sk_nulls_for_each_from(sk, node) {
|
|
if (!net_eq(sock_net(sk), net))
|
|
continue;
|
|
if (sk->sk_family == st->family) {
|
|
cur = sk;
|
|
goto out;
|
|
}
|
|
icsk = inet_csk(sk);
|
|
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);
|
|
}
|
|
spin_unlock_bh(&ilb->lock);
|
|
st->offset = 0;
|
|
if (++st->bucket < INET_LHTABLE_SIZE) {
|
|
ilb = &tcp_hashinfo.listening_hash[st->bucket];
|
|
spin_lock_bh(&ilb->lock);
|
|
sk = sk_nulls_head(&ilb->head);
|
|
goto get_sk;
|
|
}
|
|
cur = NULL;
|
|
out:
|
|
return cur;
|
|
}
|
|
|
|
static void *listening_get_idx(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
struct tcp_iter_state *st = seq->private;
|
|
void *rc;
|
|
|
|
st->bucket = 0;
|
|
st->offset = 0;
|
|
rc = listening_get_next(seq, NULL);
|
|
|
|
while (rc && *pos) {
|
|
rc = listening_get_next(seq, rc);
|
|
--*pos;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static inline int empty_bucket(struct tcp_iter_state *st)
|
|
{
|
|
return hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].chain) &&
|
|
hlist_nulls_empty(&tcp_hashinfo.ehash[st->bucket].twchain);
|
|
}
|
|
|
|
/*
|
|
* Get first established socket starting from bucket given in st->bucket.
|
|
* If st->bucket is zero, the very first socket in the hash is returned.
|
|
*/
|
|
static void *established_get_first(struct seq_file *seq)
|
|
{
|
|
struct tcp_iter_state *st = seq->private;
|
|
struct net *net = seq_file_net(seq);
|
|
void *rc = NULL;
|
|
|
|
st->offset = 0;
|
|
for (; st->bucket <= tcp_hashinfo.ehash_mask; ++st->bucket) {
|
|
struct sock *sk;
|
|
struct hlist_nulls_node *node;
|
|
struct inet_timewait_sock *tw;
|
|
spinlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
|
|
|
|
/* Lockless fast path for the common case of empty buckets */
|
|
if (empty_bucket(st))
|
|
continue;
|
|
|
|
spin_lock_bh(lock);
|
|
sk_nulls_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
|
|
if (sk->sk_family != st->family ||
|
|
!net_eq(sock_net(sk), net)) {
|
|
continue;
|
|
}
|
|
rc = sk;
|
|
goto out;
|
|
}
|
|
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 ||
|
|
!net_eq(twsk_net(tw), net)) {
|
|
continue;
|
|
}
|
|
rc = tw;
|
|
goto out;
|
|
}
|
|
spin_unlock_bh(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_nulls_node *node;
|
|
struct tcp_iter_state *st = seq->private;
|
|
struct net *net = seq_file_net(seq);
|
|
|
|
++st->num;
|
|
++st->offset;
|
|
|
|
if (st->state == TCP_SEQ_STATE_TIME_WAIT) {
|
|
tw = cur;
|
|
tw = tw_next(tw);
|
|
get_tw:
|
|
while (tw && (tw->tw_family != st->family || !net_eq(twsk_net(tw), net))) {
|
|
tw = tw_next(tw);
|
|
}
|
|
if (tw) {
|
|
cur = tw;
|
|
goto out;
|
|
}
|
|
spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
|
|
/* Look for next non empty bucket */
|
|
st->offset = 0;
|
|
while (++st->bucket <= tcp_hashinfo.ehash_mask &&
|
|
empty_bucket(st))
|
|
;
|
|
if (st->bucket > tcp_hashinfo.ehash_mask)
|
|
return NULL;
|
|
|
|
spin_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
|
|
sk = sk_nulls_head(&tcp_hashinfo.ehash[st->bucket].chain);
|
|
} else
|
|
sk = sk_nulls_next(sk);
|
|
|
|
sk_nulls_for_each_from(sk, node) {
|
|
if (sk->sk_family == st->family && net_eq(sock_net(sk), net))
|
|
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)
|
|
{
|
|
struct tcp_iter_state *st = seq->private;
|
|
void *rc;
|
|
|
|
st->bucket = 0;
|
|
rc = established_get_first(seq);
|
|
|
|
while (rc && pos) {
|
|
rc = established_get_next(seq, rc);
|
|
--pos;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static void *tcp_get_idx(struct seq_file *seq, loff_t pos)
|
|
{
|
|
void *rc;
|
|
struct tcp_iter_state *st = seq->private;
|
|
|
|
st->state = TCP_SEQ_STATE_LISTENING;
|
|
rc = listening_get_idx(seq, &pos);
|
|
|
|
if (!rc) {
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
rc = established_get_idx(seq, pos);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
static void *tcp_seek_last_pos(struct seq_file *seq)
|
|
{
|
|
struct tcp_iter_state *st = seq->private;
|
|
int offset = st->offset;
|
|
int orig_num = st->num;
|
|
void *rc = NULL;
|
|
|
|
switch (st->state) {
|
|
case TCP_SEQ_STATE_OPENREQ:
|
|
case TCP_SEQ_STATE_LISTENING:
|
|
if (st->bucket >= INET_LHTABLE_SIZE)
|
|
break;
|
|
st->state = TCP_SEQ_STATE_LISTENING;
|
|
rc = listening_get_next(seq, NULL);
|
|
while (offset-- && rc)
|
|
rc = listening_get_next(seq, rc);
|
|
if (rc)
|
|
break;
|
|
st->bucket = 0;
|
|
/* Fallthrough */
|
|
case TCP_SEQ_STATE_ESTABLISHED:
|
|
case TCP_SEQ_STATE_TIME_WAIT:
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
if (st->bucket > tcp_hashinfo.ehash_mask)
|
|
break;
|
|
rc = established_get_first(seq);
|
|
while (offset-- && rc)
|
|
rc = established_get_next(seq, rc);
|
|
}
|
|
|
|
st->num = orig_num;
|
|
|
|
return rc;
|
|
}
|
|
|
|
static void *tcp_seq_start(struct seq_file *seq, loff_t *pos)
|
|
{
|
|
struct tcp_iter_state *st = seq->private;
|
|
void *rc;
|
|
|
|
if (*pos && *pos == st->last_pos) {
|
|
rc = tcp_seek_last_pos(seq);
|
|
if (rc)
|
|
goto out;
|
|
}
|
|
|
|
st->state = TCP_SEQ_STATE_LISTENING;
|
|
st->num = 0;
|
|
st->bucket = 0;
|
|
st->offset = 0;
|
|
rc = *pos ? tcp_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
|
|
|
|
out:
|
|
st->last_pos = *pos;
|
|
return rc;
|
|
}
|
|
|
|
static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
|
|
{
|
|
struct tcp_iter_state *st = seq->private;
|
|
void *rc = NULL;
|
|
|
|
if (v == SEQ_START_TOKEN) {
|
|
rc = tcp_get_idx(seq, 0);
|
|
goto out;
|
|
}
|
|
|
|
switch (st->state) {
|
|
case TCP_SEQ_STATE_OPENREQ:
|
|
case TCP_SEQ_STATE_LISTENING:
|
|
rc = listening_get_next(seq, v);
|
|
if (!rc) {
|
|
st->state = TCP_SEQ_STATE_ESTABLISHED;
|
|
st->bucket = 0;
|
|
st->offset = 0;
|
|
rc = established_get_first(seq);
|
|
}
|
|
break;
|
|
case TCP_SEQ_STATE_ESTABLISHED:
|
|
case TCP_SEQ_STATE_TIME_WAIT:
|
|
rc = established_get_next(seq, v);
|
|
break;
|
|
}
|
|
out:
|
|
++*pos;
|
|
st->last_pos = *pos;
|
|
return rc;
|
|
}
|
|
|
|
static void tcp_seq_stop(struct seq_file *seq, void *v)
|
|
{
|
|
struct tcp_iter_state *st = seq->private;
|
|
|
|
switch (st->state) {
|
|
case TCP_SEQ_STATE_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)
|
|
spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock);
|
|
break;
|
|
case TCP_SEQ_STATE_TIME_WAIT:
|
|
case TCP_SEQ_STATE_ESTABLISHED:
|
|
if (v)
|
|
spin_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int tcp_seq_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct tcp_seq_afinfo *afinfo = PDE(inode)->data;
|
|
struct tcp_iter_state *s;
|
|
int err;
|
|
|
|
err = seq_open_net(inode, file, &afinfo->seq_ops,
|
|
sizeof(struct tcp_iter_state));
|
|
if (err < 0)
|
|
return err;
|
|
|
|
s = ((struct seq_file *)file->private_data)->private;
|
|
s->family = afinfo->family;
|
|
s->last_pos = 0;
|
|
return 0;
|
|
}
|
|
|
|
int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo)
|
|
{
|
|
int rc = 0;
|
|
struct proc_dir_entry *p;
|
|
|
|
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_net;
|
|
|
|
afinfo->seq_ops.start = tcp_seq_start;
|
|
afinfo->seq_ops.next = tcp_seq_next;
|
|
afinfo->seq_ops.stop = tcp_seq_stop;
|
|
|
|
p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
|
|
&afinfo->seq_fops, afinfo);
|
|
if (!p)
|
|
rc = -ENOMEM;
|
|
return rc;
|
|
}
|
|
EXPORT_SYMBOL(tcp_proc_register);
|
|
|
|
void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo)
|
|
{
|
|
proc_net_remove(net, afinfo->name);
|
|
}
|
|
EXPORT_SYMBOL(tcp_proc_unregister);
|
|
|
|
static void get_openreq4(struct sock *sk, struct request_sock *req,
|
|
struct seq_file *f, int i, int uid, int *len)
|
|
{
|
|
const struct inet_request_sock *ireq = inet_rsk(req);
|
|
int ttd = req->expires - jiffies;
|
|
|
|
seq_printf(f, "%4d: %08X:%04X %08X:%04X"
|
|
" %02X %08X:%08X %02X:%08lX %08X %5d %8d %u %d %p%n",
|
|
i,
|
|
ireq->loc_addr,
|
|
ntohs(inet_sk(sk)->inet_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,
|
|
len);
|
|
}
|
|
|
|
static void get_tcp4_sock(struct sock *sk, struct seq_file *f, int i, int *len)
|
|
{
|
|
int timer_active;
|
|
unsigned long timer_expires;
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
struct inet_sock *inet = inet_sk(sk);
|
|
__be32 dest = inet->inet_daddr;
|
|
__be32 src = inet->inet_rcv_saddr;
|
|
__u16 destp = ntohs(inet->inet_dport);
|
|
__u16 srcp = ntohs(inet->inet_sport);
|
|
int rx_queue;
|
|
|
|
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(&sk->sk_timer)) {
|
|
timer_active = 2;
|
|
timer_expires = sk->sk_timer.expires;
|
|
} else {
|
|
timer_active = 0;
|
|
timer_expires = jiffies;
|
|
}
|
|
|
|
if (sk->sk_state == TCP_LISTEN)
|
|
rx_queue = sk->sk_ack_backlog;
|
|
else
|
|
/*
|
|
* because we dont lock socket, we might find a transient negative value
|
|
*/
|
|
rx_queue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0);
|
|
|
|
seq_printf(f, "%4d: %08X:%04X %08X:%04X %02X %08X:%08X %02X:%08lX "
|
|
"%08X %5d %8d %lu %d %p %lu %lu %u %u %d%n",
|
|
i, src, srcp, dest, destp, sk->sk_state,
|
|
tp->write_seq - tp->snd_una,
|
|
rx_queue,
|
|
timer_active,
|
|
jiffies_to_clock_t(timer_expires - jiffies),
|
|
icsk->icsk_retransmits,
|
|
sock_i_uid(sk),
|
|
icsk->icsk_probes_out,
|
|
sock_i_ino(sk),
|
|
atomic_read(&sk->sk_refcnt), sk,
|
|
jiffies_to_clock_t(icsk->icsk_rto),
|
|
jiffies_to_clock_t(icsk->icsk_ack.ato),
|
|
(icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
|
|
tp->snd_cwnd,
|
|
tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh,
|
|
len);
|
|
}
|
|
|
|
static void get_timewait4_sock(struct inet_timewait_sock *tw,
|
|
struct seq_file *f, int i, int *len)
|
|
{
|
|
__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);
|
|
|
|
seq_printf(f, "%4d: %08X:%04X %08X:%04X"
|
|
" %02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %p%n",
|
|
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, len);
|
|
}
|
|
|
|
#define TMPSZ 150
|
|
|
|
static int tcp4_seq_show(struct seq_file *seq, void *v)
|
|
{
|
|
struct tcp_iter_state *st;
|
|
int len;
|
|
|
|
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, seq, st->num, &len);
|
|
break;
|
|
case TCP_SEQ_STATE_OPENREQ:
|
|
get_openreq4(st->syn_wait_sk, v, seq, st->num, st->uid, &len);
|
|
break;
|
|
case TCP_SEQ_STATE_TIME_WAIT:
|
|
get_timewait4_sock(v, seq, st->num, &len);
|
|
break;
|
|
}
|
|
seq_printf(seq, "%*s\n", TMPSZ - 1 - len, "");
|
|
out:
|
|
return 0;
|
|
}
|
|
|
|
static struct tcp_seq_afinfo tcp4_seq_afinfo = {
|
|
.name = "tcp",
|
|
.family = AF_INET,
|
|
.seq_fops = {
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.seq_ops = {
|
|
.show = tcp4_seq_show,
|
|
},
|
|
};
|
|
|
|
static int __net_init tcp4_proc_init_net(struct net *net)
|
|
{
|
|
return tcp_proc_register(net, &tcp4_seq_afinfo);
|
|
}
|
|
|
|
static void __net_exit tcp4_proc_exit_net(struct net *net)
|
|
{
|
|
tcp_proc_unregister(net, &tcp4_seq_afinfo);
|
|
}
|
|
|
|
static struct pernet_operations tcp4_net_ops = {
|
|
.init = tcp4_proc_init_net,
|
|
.exit = tcp4_proc_exit_net,
|
|
};
|
|
|
|
int __init tcp4_proc_init(void)
|
|
{
|
|
return register_pernet_subsys(&tcp4_net_ops);
|
|
}
|
|
|
|
void tcp4_proc_exit(void)
|
|
{
|
|
unregister_pernet_subsys(&tcp4_net_ops);
|
|
}
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb)
|
|
{
|
|
const struct iphdr *iph = skb_gro_network_header(skb);
|
|
|
|
switch (skb->ip_summed) {
|
|
case CHECKSUM_COMPLETE:
|
|
if (!tcp_v4_check(skb_gro_len(skb), iph->saddr, iph->daddr,
|
|
skb->csum)) {
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
break;
|
|
}
|
|
|
|
/* fall through */
|
|
case CHECKSUM_NONE:
|
|
NAPI_GRO_CB(skb)->flush = 1;
|
|
return NULL;
|
|
}
|
|
|
|
return tcp_gro_receive(head, skb);
|
|
}
|
|
|
|
int tcp4_gro_complete(struct sk_buff *skb)
|
|
{
|
|
const struct iphdr *iph = ip_hdr(skb);
|
|
struct tcphdr *th = tcp_hdr(skb);
|
|
|
|
th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb),
|
|
iph->saddr, iph->daddr, 0);
|
|
skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
|
|
|
|
return tcp_gro_complete(skb);
|
|
}
|
|
|
|
struct proto tcp_prot = {
|
|
.name = "TCP",
|
|
.owner = THIS_MODULE,
|
|
.close = tcp_close,
|
|
.connect = tcp_v4_connect,
|
|
.disconnect = tcp_disconnect,
|
|
.accept = inet_csk_accept,
|
|
.ioctl = tcp_ioctl,
|
|
.init = tcp_v4_init_sock,
|
|
.destroy = tcp_v4_destroy_sock,
|
|
.shutdown = tcp_shutdown,
|
|
.setsockopt = tcp_setsockopt,
|
|
.getsockopt = tcp_getsockopt,
|
|
.recvmsg = tcp_recvmsg,
|
|
.sendmsg = tcp_sendmsg,
|
|
.sendpage = tcp_sendpage,
|
|
.backlog_rcv = tcp_v4_do_rcv,
|
|
.hash = inet_hash,
|
|
.unhash = inet_unhash,
|
|
.get_port = inet_csk_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),
|
|
.slab_flags = SLAB_DESTROY_BY_RCU,
|
|
.twsk_prot = &tcp_timewait_sock_ops,
|
|
.rsk_prot = &tcp_request_sock_ops,
|
|
.h.hashinfo = &tcp_hashinfo,
|
|
.no_autobind = true,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_setsockopt = compat_tcp_setsockopt,
|
|
.compat_getsockopt = compat_tcp_getsockopt,
|
|
#endif
|
|
};
|
|
EXPORT_SYMBOL(tcp_prot);
|
|
|
|
|
|
static int __net_init tcp_sk_init(struct net *net)
|
|
{
|
|
return inet_ctl_sock_create(&net->ipv4.tcp_sock,
|
|
PF_INET, SOCK_RAW, IPPROTO_TCP, net);
|
|
}
|
|
|
|
static void __net_exit tcp_sk_exit(struct net *net)
|
|
{
|
|
inet_ctl_sock_destroy(net->ipv4.tcp_sock);
|
|
}
|
|
|
|
static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)
|
|
{
|
|
inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET);
|
|
}
|
|
|
|
static struct pernet_operations __net_initdata tcp_sk_ops = {
|
|
.init = tcp_sk_init,
|
|
.exit = tcp_sk_exit,
|
|
.exit_batch = tcp_sk_exit_batch,
|
|
};
|
|
|
|
void __init tcp_v4_init(void)
|
|
{
|
|
inet_hashinfo_init(&tcp_hashinfo);
|
|
if (register_pernet_subsys(&tcp_sk_ops))
|
|
panic("Failed to create the TCP control socket.\n");
|
|
}
|