2005-04-16 15:20:36 -07:00
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/*
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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_minisocks.c,v 1.15 2002/02/01 22:01:04 davem Exp $
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*
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2005-05-05 16:16:16 -07:00
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* Authors: Ross Biro
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2005-04-16 15:20:36 -07:00
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* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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* Mark Evans, <evansmp@uhura.aston.ac.uk>
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* Corey Minyard <wf-rch!minyard@relay.EU.net>
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* Florian La Roche, <flla@stud.uni-sb.de>
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* Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
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* Linus Torvalds, <torvalds@cs.helsinki.fi>
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* Alan Cox, <gw4pts@gw4pts.ampr.org>
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* Matthew Dillon, <dillon@apollo.west.oic.com>
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* Arnt Gulbrandsen, <agulbra@nvg.unit.no>
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* Jorge Cwik, <jorge@laser.satlink.net>
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*/
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#include <linux/config.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/sysctl.h>
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#include <linux/workqueue.h>
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#include <net/tcp.h>
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#include <net/inet_common.h>
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#include <net/xfrm.h>
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#ifdef CONFIG_SYSCTL
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#define SYNC_INIT 0 /* let the user enable it */
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#else
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#define SYNC_INIT 1
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#endif
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int sysctl_tcp_tw_recycle;
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int sysctl_tcp_max_tw_buckets = NR_FILE*2;
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int sysctl_tcp_syncookies = SYNC_INIT;
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int sysctl_tcp_abort_on_overflow;
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static void tcp_tw_schedule(struct tcp_tw_bucket *tw, int timeo);
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static __inline__ int tcp_in_window(u32 seq, u32 end_seq, u32 s_win, u32 e_win)
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{
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if (seq == s_win)
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return 1;
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if (after(end_seq, s_win) && before(seq, e_win))
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return 1;
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return (seq == e_win && seq == end_seq);
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}
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/* New-style handling of TIME_WAIT sockets. */
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int tcp_tw_count;
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/* Must be called with locally disabled BHs. */
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static void tcp_timewait_kill(struct tcp_tw_bucket *tw)
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{
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struct tcp_ehash_bucket *ehead;
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struct tcp_bind_hashbucket *bhead;
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struct tcp_bind_bucket *tb;
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/* Unlink from established hashes. */
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ehead = &tcp_ehash[tw->tw_hashent];
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write_lock(&ehead->lock);
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if (hlist_unhashed(&tw->tw_node)) {
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write_unlock(&ehead->lock);
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return;
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}
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__hlist_del(&tw->tw_node);
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sk_node_init(&tw->tw_node);
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write_unlock(&ehead->lock);
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/* Disassociate with bind bucket. */
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bhead = &tcp_bhash[tcp_bhashfn(tw->tw_num)];
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spin_lock(&bhead->lock);
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tb = tw->tw_tb;
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__hlist_del(&tw->tw_bind_node);
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tw->tw_tb = NULL;
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tcp_bucket_destroy(tb);
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spin_unlock(&bhead->lock);
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#ifdef INET_REFCNT_DEBUG
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if (atomic_read(&tw->tw_refcnt) != 1) {
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printk(KERN_DEBUG "tw_bucket %p refcnt=%d\n", tw,
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atomic_read(&tw->tw_refcnt));
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}
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#endif
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tcp_tw_put(tw);
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}
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/*
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* * Main purpose of TIME-WAIT state is to close connection gracefully,
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* when one of ends sits in LAST-ACK or CLOSING retransmitting FIN
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* (and, probably, tail of data) and one or more our ACKs are lost.
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* * What is TIME-WAIT timeout? It is associated with maximal packet
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* lifetime in the internet, which results in wrong conclusion, that
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* it is set to catch "old duplicate segments" wandering out of their path.
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* It is not quite correct. This timeout is calculated so that it exceeds
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* maximal retransmission timeout enough to allow to lose one (or more)
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* segments sent by peer and our ACKs. This time may be calculated from RTO.
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* * When TIME-WAIT socket receives RST, it means that another end
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* finally closed and we are allowed to kill TIME-WAIT too.
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* * Second purpose of TIME-WAIT is catching old duplicate segments.
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* Well, certainly it is pure paranoia, but if we load TIME-WAIT
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* with this semantics, we MUST NOT kill TIME-WAIT state with RSTs.
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* * If we invented some more clever way to catch duplicates
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* (f.e. based on PAWS), we could truncate TIME-WAIT to several RTOs.
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*
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* The algorithm below is based on FORMAL INTERPRETATION of RFCs.
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* When you compare it to RFCs, please, read section SEGMENT ARRIVES
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* from the very beginning.
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*
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* NOTE. With recycling (and later with fin-wait-2) TW bucket
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* is _not_ stateless. It means, that strictly speaking we must
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* spinlock it. I do not want! Well, probability of misbehaviour
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* is ridiculously low and, seems, we could use some mb() tricks
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* to avoid misread sequence numbers, states etc. --ANK
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*/
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enum tcp_tw_status
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tcp_timewait_state_process(struct tcp_tw_bucket *tw, struct sk_buff *skb,
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struct tcphdr *th, unsigned len)
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{
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struct tcp_options_received tmp_opt;
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int paws_reject = 0;
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tmp_opt.saw_tstamp = 0;
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if (th->doff > (sizeof(struct tcphdr) >> 2) && tw->tw_ts_recent_stamp) {
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tcp_parse_options(skb, &tmp_opt, 0);
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if (tmp_opt.saw_tstamp) {
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tmp_opt.ts_recent = tw->tw_ts_recent;
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tmp_opt.ts_recent_stamp = tw->tw_ts_recent_stamp;
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paws_reject = tcp_paws_check(&tmp_opt, th->rst);
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}
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}
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if (tw->tw_substate == TCP_FIN_WAIT2) {
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/* Just repeat all the checks of tcp_rcv_state_process() */
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/* Out of window, send ACK */
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if (paws_reject ||
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!tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq,
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tw->tw_rcv_nxt,
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tw->tw_rcv_nxt + tw->tw_rcv_wnd))
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return TCP_TW_ACK;
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if (th->rst)
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goto kill;
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if (th->syn && !before(TCP_SKB_CB(skb)->seq, tw->tw_rcv_nxt))
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goto kill_with_rst;
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/* Dup ACK? */
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if (!after(TCP_SKB_CB(skb)->end_seq, tw->tw_rcv_nxt) ||
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TCP_SKB_CB(skb)->end_seq == TCP_SKB_CB(skb)->seq) {
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tcp_tw_put(tw);
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return TCP_TW_SUCCESS;
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}
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/* New data or FIN. If new data arrive after half-duplex close,
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* reset.
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*/
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if (!th->fin ||
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TCP_SKB_CB(skb)->end_seq != tw->tw_rcv_nxt + 1) {
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kill_with_rst:
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tcp_tw_deschedule(tw);
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tcp_tw_put(tw);
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return TCP_TW_RST;
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}
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/* FIN arrived, enter true time-wait state. */
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tw->tw_substate = TCP_TIME_WAIT;
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tw->tw_rcv_nxt = TCP_SKB_CB(skb)->end_seq;
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if (tmp_opt.saw_tstamp) {
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tw->tw_ts_recent_stamp = xtime.tv_sec;
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tw->tw_ts_recent = tmp_opt.rcv_tsval;
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}
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/* I am shamed, but failed to make it more elegant.
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* Yes, it is direct reference to IP, which is impossible
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* to generalize to IPv6. Taking into account that IPv6
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* do not undertsnad recycling in any case, it not
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* a big problem in practice. --ANK */
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if (tw->tw_family == AF_INET &&
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sysctl_tcp_tw_recycle && tw->tw_ts_recent_stamp &&
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tcp_v4_tw_remember_stamp(tw))
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tcp_tw_schedule(tw, tw->tw_timeout);
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else
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tcp_tw_schedule(tw, TCP_TIMEWAIT_LEN);
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return TCP_TW_ACK;
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}
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/*
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* Now real TIME-WAIT state.
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*
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* RFC 1122:
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* "When a connection is [...] on TIME-WAIT state [...]
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* [a TCP] MAY accept a new SYN from the remote TCP to
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* reopen the connection directly, if it:
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*
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* (1) assigns its initial sequence number for the new
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* connection to be larger than the largest sequence
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* number it used on the previous connection incarnation,
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* and
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*
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* (2) returns to TIME-WAIT state if the SYN turns out
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* to be an old duplicate".
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*/
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if (!paws_reject &&
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(TCP_SKB_CB(skb)->seq == tw->tw_rcv_nxt &&
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(TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq || th->rst))) {
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/* In window segment, it may be only reset or bare ack. */
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if (th->rst) {
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/* This is TIME_WAIT assasination, in two flavors.
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* Oh well... nobody has a sufficient solution to this
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* protocol bug yet.
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*/
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if (sysctl_tcp_rfc1337 == 0) {
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kill:
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tcp_tw_deschedule(tw);
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tcp_tw_put(tw);
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return TCP_TW_SUCCESS;
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}
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}
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tcp_tw_schedule(tw, TCP_TIMEWAIT_LEN);
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if (tmp_opt.saw_tstamp) {
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tw->tw_ts_recent = tmp_opt.rcv_tsval;
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tw->tw_ts_recent_stamp = xtime.tv_sec;
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}
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tcp_tw_put(tw);
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return TCP_TW_SUCCESS;
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}
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/* Out of window segment.
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All the segments are ACKed immediately.
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The only exception is new SYN. We accept it, if it is
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not old duplicate and we are not in danger to be killed
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by delayed old duplicates. RFC check is that it has
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newer sequence number works at rates <40Mbit/sec.
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However, if paws works, it is reliable AND even more,
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we even may relax silly seq space cutoff.
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RED-PEN: we violate main RFC requirement, if this SYN will appear
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old duplicate (i.e. we receive RST in reply to SYN-ACK),
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we must return socket to time-wait state. It is not good,
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but not fatal yet.
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*/
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if (th->syn && !th->rst && !th->ack && !paws_reject &&
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(after(TCP_SKB_CB(skb)->seq, tw->tw_rcv_nxt) ||
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(tmp_opt.saw_tstamp && (s32)(tw->tw_ts_recent - tmp_opt.rcv_tsval) < 0))) {
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u32 isn = tw->tw_snd_nxt + 65535 + 2;
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if (isn == 0)
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isn++;
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TCP_SKB_CB(skb)->when = isn;
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return TCP_TW_SYN;
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}
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if (paws_reject)
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NET_INC_STATS_BH(LINUX_MIB_PAWSESTABREJECTED);
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if(!th->rst) {
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/* In this case we must reset the TIMEWAIT timer.
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*
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* If it is ACKless SYN it may be both old duplicate
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* and new good SYN with random sequence number <rcv_nxt.
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* Do not reschedule in the last case.
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*/
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if (paws_reject || th->ack)
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tcp_tw_schedule(tw, TCP_TIMEWAIT_LEN);
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/* Send ACK. Note, we do not put the bucket,
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* it will be released by caller.
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*/
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return TCP_TW_ACK;
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}
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tcp_tw_put(tw);
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return TCP_TW_SUCCESS;
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}
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/* Enter the time wait state. This is called with locally disabled BH.
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* Essentially we whip up a timewait bucket, copy the
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* relevant info into it from the SK, and mess with hash chains
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* and list linkage.
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*/
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static void __tcp_tw_hashdance(struct sock *sk, struct tcp_tw_bucket *tw)
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{
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struct tcp_ehash_bucket *ehead = &tcp_ehash[sk->sk_hashent];
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struct tcp_bind_hashbucket *bhead;
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/* Step 1: Put TW into bind hash. Original socket stays there too.
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Note, that any socket with inet_sk(sk)->num != 0 MUST be bound in
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binding cache, even if it is closed.
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*/
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bhead = &tcp_bhash[tcp_bhashfn(inet_sk(sk)->num)];
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spin_lock(&bhead->lock);
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tw->tw_tb = tcp_sk(sk)->bind_hash;
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BUG_TRAP(tcp_sk(sk)->bind_hash);
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tw_add_bind_node(tw, &tw->tw_tb->owners);
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spin_unlock(&bhead->lock);
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write_lock(&ehead->lock);
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/* Step 2: Remove SK from established hash. */
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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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/* Step 3: Hash TW into TIMEWAIT half of established hash table. */
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tw_add_node(tw, &(ehead + tcp_ehash_size)->chain);
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atomic_inc(&tw->tw_refcnt);
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write_unlock(&ehead->lock);
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}
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/*
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* Move a socket to time-wait or dead fin-wait-2 state.
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*/
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void tcp_time_wait(struct sock *sk, int state, int timeo)
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{
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struct tcp_tw_bucket *tw = NULL;
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struct tcp_sock *tp = tcp_sk(sk);
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int recycle_ok = 0;
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if (sysctl_tcp_tw_recycle && tp->rx_opt.ts_recent_stamp)
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recycle_ok = tp->af_specific->remember_stamp(sk);
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if (tcp_tw_count < sysctl_tcp_max_tw_buckets)
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tw = kmem_cache_alloc(tcp_timewait_cachep, SLAB_ATOMIC);
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if(tw != NULL) {
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struct inet_sock *inet = inet_sk(sk);
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int rto = (tp->rto<<2) - (tp->rto>>1);
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|
|
/* Give us an identity. */
|
|
|
|
tw->tw_daddr = inet->daddr;
|
|
|
|
tw->tw_rcv_saddr = inet->rcv_saddr;
|
|
|
|
tw->tw_bound_dev_if = sk->sk_bound_dev_if;
|
|
|
|
tw->tw_num = inet->num;
|
|
|
|
tw->tw_state = TCP_TIME_WAIT;
|
|
|
|
tw->tw_substate = state;
|
|
|
|
tw->tw_sport = inet->sport;
|
|
|
|
tw->tw_dport = inet->dport;
|
|
|
|
tw->tw_family = sk->sk_family;
|
|
|
|
tw->tw_reuse = sk->sk_reuse;
|
|
|
|
tw->tw_rcv_wscale = tp->rx_opt.rcv_wscale;
|
|
|
|
atomic_set(&tw->tw_refcnt, 1);
|
|
|
|
|
|
|
|
tw->tw_hashent = sk->sk_hashent;
|
|
|
|
tw->tw_rcv_nxt = tp->rcv_nxt;
|
|
|
|
tw->tw_snd_nxt = tp->snd_nxt;
|
|
|
|
tw->tw_rcv_wnd = tcp_receive_window(tp);
|
|
|
|
tw->tw_ts_recent = tp->rx_opt.ts_recent;
|
|
|
|
tw->tw_ts_recent_stamp = tp->rx_opt.ts_recent_stamp;
|
|
|
|
tw_dead_node_init(tw);
|
|
|
|
|
|
|
|
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
|
|
|
|
if (tw->tw_family == PF_INET6) {
|
|
|
|
struct ipv6_pinfo *np = inet6_sk(sk);
|
|
|
|
|
|
|
|
ipv6_addr_copy(&tw->tw_v6_daddr, &np->daddr);
|
|
|
|
ipv6_addr_copy(&tw->tw_v6_rcv_saddr, &np->rcv_saddr);
|
|
|
|
tw->tw_v6_ipv6only = np->ipv6only;
|
|
|
|
} else {
|
|
|
|
memset(&tw->tw_v6_daddr, 0, sizeof(tw->tw_v6_daddr));
|
|
|
|
memset(&tw->tw_v6_rcv_saddr, 0, sizeof(tw->tw_v6_rcv_saddr));
|
|
|
|
tw->tw_v6_ipv6only = 0;
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
/* Linkage updates. */
|
|
|
|
__tcp_tw_hashdance(sk, tw);
|
|
|
|
|
|
|
|
/* Get the TIME_WAIT timeout firing. */
|
|
|
|
if (timeo < rto)
|
|
|
|
timeo = rto;
|
|
|
|
|
|
|
|
if (recycle_ok) {
|
|
|
|
tw->tw_timeout = rto;
|
|
|
|
} else {
|
|
|
|
tw->tw_timeout = TCP_TIMEWAIT_LEN;
|
|
|
|
if (state == TCP_TIME_WAIT)
|
|
|
|
timeo = TCP_TIMEWAIT_LEN;
|
|
|
|
}
|
|
|
|
|
|
|
|
tcp_tw_schedule(tw, timeo);
|
|
|
|
tcp_tw_put(tw);
|
|
|
|
} else {
|
|
|
|
/* Sorry, if we're out of memory, just CLOSE this
|
|
|
|
* socket up. We've got bigger problems than
|
|
|
|
* non-graceful socket closings.
|
|
|
|
*/
|
|
|
|
if (net_ratelimit())
|
|
|
|
printk(KERN_INFO "TCP: time wait bucket table overflow\n");
|
|
|
|
}
|
|
|
|
|
|
|
|
tcp_update_metrics(sk);
|
|
|
|
tcp_done(sk);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Kill off TIME_WAIT sockets once their lifetime has expired. */
|
|
|
|
static int tcp_tw_death_row_slot;
|
|
|
|
|
|
|
|
static void tcp_twkill(unsigned long);
|
|
|
|
|
|
|
|
/* TIME_WAIT reaping mechanism. */
|
|
|
|
#define TCP_TWKILL_SLOTS 8 /* Please keep this a power of 2. */
|
|
|
|
#define TCP_TWKILL_PERIOD (TCP_TIMEWAIT_LEN/TCP_TWKILL_SLOTS)
|
|
|
|
|
|
|
|
#define TCP_TWKILL_QUOTA 100
|
|
|
|
|
|
|
|
static struct hlist_head tcp_tw_death_row[TCP_TWKILL_SLOTS];
|
|
|
|
static DEFINE_SPINLOCK(tw_death_lock);
|
|
|
|
static struct timer_list tcp_tw_timer = TIMER_INITIALIZER(tcp_twkill, 0, 0);
|
|
|
|
static void twkill_work(void *);
|
|
|
|
static DECLARE_WORK(tcp_twkill_work, twkill_work, NULL);
|
|
|
|
static u32 twkill_thread_slots;
|
|
|
|
|
|
|
|
/* Returns non-zero if quota exceeded. */
|
|
|
|
static int tcp_do_twkill_work(int slot, unsigned int quota)
|
|
|
|
{
|
|
|
|
struct tcp_tw_bucket *tw;
|
|
|
|
struct hlist_node *node;
|
|
|
|
unsigned int killed;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
/* NOTE: compare this to previous version where lock
|
|
|
|
* was released after detaching chain. It was racy,
|
|
|
|
* because tw buckets are scheduled in not serialized context
|
|
|
|
* in 2.3 (with netfilter), and with softnet it is common, because
|
|
|
|
* soft irqs are not sequenced.
|
|
|
|
*/
|
|
|
|
killed = 0;
|
|
|
|
ret = 0;
|
|
|
|
rescan:
|
|
|
|
tw_for_each_inmate(tw, node, &tcp_tw_death_row[slot]) {
|
|
|
|
__tw_del_dead_node(tw);
|
|
|
|
spin_unlock(&tw_death_lock);
|
|
|
|
tcp_timewait_kill(tw);
|
|
|
|
tcp_tw_put(tw);
|
|
|
|
killed++;
|
|
|
|
spin_lock(&tw_death_lock);
|
|
|
|
if (killed > quota) {
|
|
|
|
ret = 1;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* While we dropped tw_death_lock, another cpu may have
|
|
|
|
* killed off the next TW bucket in the list, therefore
|
|
|
|
* do a fresh re-read of the hlist head node with the
|
|
|
|
* lock reacquired. We still use the hlist traversal
|
|
|
|
* macro in order to get the prefetches.
|
|
|
|
*/
|
|
|
|
goto rescan;
|
|
|
|
}
|
|
|
|
|
|
|
|
tcp_tw_count -= killed;
|
|
|
|
NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITED, killed);
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void tcp_twkill(unsigned long dummy)
|
|
|
|
{
|
|
|
|
int need_timer, ret;
|
|
|
|
|
|
|
|
spin_lock(&tw_death_lock);
|
|
|
|
|
|
|
|
if (tcp_tw_count == 0)
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
need_timer = 0;
|
|
|
|
ret = tcp_do_twkill_work(tcp_tw_death_row_slot, TCP_TWKILL_QUOTA);
|
|
|
|
if (ret) {
|
|
|
|
twkill_thread_slots |= (1 << tcp_tw_death_row_slot);
|
|
|
|
mb();
|
|
|
|
schedule_work(&tcp_twkill_work);
|
|
|
|
need_timer = 1;
|
|
|
|
} else {
|
|
|
|
/* We purged the entire slot, anything left? */
|
|
|
|
if (tcp_tw_count)
|
|
|
|
need_timer = 1;
|
|
|
|
}
|
|
|
|
tcp_tw_death_row_slot =
|
|
|
|
((tcp_tw_death_row_slot + 1) & (TCP_TWKILL_SLOTS - 1));
|
|
|
|
if (need_timer)
|
|
|
|
mod_timer(&tcp_tw_timer, jiffies + TCP_TWKILL_PERIOD);
|
|
|
|
out:
|
|
|
|
spin_unlock(&tw_death_lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
extern void twkill_slots_invalid(void);
|
|
|
|
|
|
|
|
static void twkill_work(void *dummy)
|
|
|
|
{
|
|
|
|
int i;
|
|
|
|
|
|
|
|
if ((TCP_TWKILL_SLOTS - 1) > (sizeof(twkill_thread_slots) * 8))
|
|
|
|
twkill_slots_invalid();
|
|
|
|
|
|
|
|
while (twkill_thread_slots) {
|
|
|
|
spin_lock_bh(&tw_death_lock);
|
|
|
|
for (i = 0; i < TCP_TWKILL_SLOTS; i++) {
|
|
|
|
if (!(twkill_thread_slots & (1 << i)))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
while (tcp_do_twkill_work(i, TCP_TWKILL_QUOTA) != 0) {
|
|
|
|
if (need_resched()) {
|
|
|
|
spin_unlock_bh(&tw_death_lock);
|
|
|
|
schedule();
|
|
|
|
spin_lock_bh(&tw_death_lock);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
twkill_thread_slots &= ~(1 << i);
|
|
|
|
}
|
|
|
|
spin_unlock_bh(&tw_death_lock);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* These are always called from BH context. See callers in
|
|
|
|
* tcp_input.c to verify this.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/* This is for handling early-kills of TIME_WAIT sockets. */
|
|
|
|
void tcp_tw_deschedule(struct tcp_tw_bucket *tw)
|
|
|
|
{
|
|
|
|
spin_lock(&tw_death_lock);
|
|
|
|
if (tw_del_dead_node(tw)) {
|
|
|
|
tcp_tw_put(tw);
|
|
|
|
if (--tcp_tw_count == 0)
|
|
|
|
del_timer(&tcp_tw_timer);
|
|
|
|
}
|
|
|
|
spin_unlock(&tw_death_lock);
|
|
|
|
tcp_timewait_kill(tw);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Short-time timewait calendar */
|
|
|
|
|
|
|
|
static int tcp_twcal_hand = -1;
|
|
|
|
static int tcp_twcal_jiffie;
|
|
|
|
static void tcp_twcal_tick(unsigned long);
|
|
|
|
static struct timer_list tcp_twcal_timer =
|
|
|
|
TIMER_INITIALIZER(tcp_twcal_tick, 0, 0);
|
|
|
|
static struct hlist_head tcp_twcal_row[TCP_TW_RECYCLE_SLOTS];
|
|
|
|
|
|
|
|
static void tcp_tw_schedule(struct tcp_tw_bucket *tw, int timeo)
|
|
|
|
{
|
|
|
|
struct hlist_head *list;
|
|
|
|
int slot;
|
|
|
|
|
|
|
|
/* timeout := RTO * 3.5
|
|
|
|
*
|
|
|
|
* 3.5 = 1+2+0.5 to wait for two retransmits.
|
|
|
|
*
|
|
|
|
* RATIONALE: if FIN arrived and we entered TIME-WAIT state,
|
|
|
|
* our ACK acking that FIN can be lost. If N subsequent retransmitted
|
|
|
|
* FINs (or previous seqments) are lost (probability of such event
|
|
|
|
* is p^(N+1), where p is probability to lose single packet and
|
|
|
|
* time to detect the loss is about RTO*(2^N - 1) with exponential
|
|
|
|
* backoff). Normal timewait length is calculated so, that we
|
|
|
|
* waited at least for one retransmitted FIN (maximal RTO is 120sec).
|
|
|
|
* [ BTW Linux. following BSD, violates this requirement waiting
|
|
|
|
* only for 60sec, we should wait at least for 240 secs.
|
|
|
|
* Well, 240 consumes too much of resources 8)
|
|
|
|
* ]
|
|
|
|
* This interval is not reduced to catch old duplicate and
|
|
|
|
* responces to our wandering segments living for two MSLs.
|
|
|
|
* However, if we use PAWS to detect
|
|
|
|
* old duplicates, we can reduce the interval to bounds required
|
|
|
|
* by RTO, rather than MSL. So, if peer understands PAWS, we
|
|
|
|
* kill tw bucket after 3.5*RTO (it is important that this number
|
|
|
|
* is greater than TS tick!) and detect old duplicates with help
|
|
|
|
* of PAWS.
|
|
|
|
*/
|
|
|
|
slot = (timeo + (1<<TCP_TW_RECYCLE_TICK) - 1) >> TCP_TW_RECYCLE_TICK;
|
|
|
|
|
|
|
|
spin_lock(&tw_death_lock);
|
|
|
|
|
|
|
|
/* Unlink it, if it was scheduled */
|
|
|
|
if (tw_del_dead_node(tw))
|
|
|
|
tcp_tw_count--;
|
|
|
|
else
|
|
|
|
atomic_inc(&tw->tw_refcnt);
|
|
|
|
|
|
|
|
if (slot >= TCP_TW_RECYCLE_SLOTS) {
|
|
|
|
/* Schedule to slow timer */
|
|
|
|
if (timeo >= TCP_TIMEWAIT_LEN) {
|
|
|
|
slot = TCP_TWKILL_SLOTS-1;
|
|
|
|
} else {
|
|
|
|
slot = (timeo + TCP_TWKILL_PERIOD-1) / TCP_TWKILL_PERIOD;
|
|
|
|
if (slot >= TCP_TWKILL_SLOTS)
|
|
|
|
slot = TCP_TWKILL_SLOTS-1;
|
|
|
|
}
|
|
|
|
tw->tw_ttd = jiffies + timeo;
|
|
|
|
slot = (tcp_tw_death_row_slot + slot) & (TCP_TWKILL_SLOTS - 1);
|
|
|
|
list = &tcp_tw_death_row[slot];
|
|
|
|
} else {
|
|
|
|
tw->tw_ttd = jiffies + (slot << TCP_TW_RECYCLE_TICK);
|
|
|
|
|
|
|
|
if (tcp_twcal_hand < 0) {
|
|
|
|
tcp_twcal_hand = 0;
|
|
|
|
tcp_twcal_jiffie = jiffies;
|
|
|
|
tcp_twcal_timer.expires = tcp_twcal_jiffie + (slot<<TCP_TW_RECYCLE_TICK);
|
|
|
|
add_timer(&tcp_twcal_timer);
|
|
|
|
} else {
|
|
|
|
if (time_after(tcp_twcal_timer.expires, jiffies + (slot<<TCP_TW_RECYCLE_TICK)))
|
|
|
|
mod_timer(&tcp_twcal_timer, jiffies + (slot<<TCP_TW_RECYCLE_TICK));
|
|
|
|
slot = (tcp_twcal_hand + slot)&(TCP_TW_RECYCLE_SLOTS-1);
|
|
|
|
}
|
|
|
|
list = &tcp_twcal_row[slot];
|
|
|
|
}
|
|
|
|
|
|
|
|
hlist_add_head(&tw->tw_death_node, list);
|
|
|
|
|
|
|
|
if (tcp_tw_count++ == 0)
|
|
|
|
mod_timer(&tcp_tw_timer, jiffies+TCP_TWKILL_PERIOD);
|
|
|
|
spin_unlock(&tw_death_lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
void tcp_twcal_tick(unsigned long dummy)
|
|
|
|
{
|
|
|
|
int n, slot;
|
|
|
|
unsigned long j;
|
|
|
|
unsigned long now = jiffies;
|
|
|
|
int killed = 0;
|
|
|
|
int adv = 0;
|
|
|
|
|
|
|
|
spin_lock(&tw_death_lock);
|
|
|
|
if (tcp_twcal_hand < 0)
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
slot = tcp_twcal_hand;
|
|
|
|
j = tcp_twcal_jiffie;
|
|
|
|
|
|
|
|
for (n=0; n<TCP_TW_RECYCLE_SLOTS; n++) {
|
|
|
|
if (time_before_eq(j, now)) {
|
|
|
|
struct hlist_node *node, *safe;
|
|
|
|
struct tcp_tw_bucket *tw;
|
|
|
|
|
|
|
|
tw_for_each_inmate_safe(tw, node, safe,
|
|
|
|
&tcp_twcal_row[slot]) {
|
|
|
|
__tw_del_dead_node(tw);
|
|
|
|
tcp_timewait_kill(tw);
|
|
|
|
tcp_tw_put(tw);
|
|
|
|
killed++;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
if (!adv) {
|
|
|
|
adv = 1;
|
|
|
|
tcp_twcal_jiffie = j;
|
|
|
|
tcp_twcal_hand = slot;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!hlist_empty(&tcp_twcal_row[slot])) {
|
|
|
|
mod_timer(&tcp_twcal_timer, j);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
j += (1<<TCP_TW_RECYCLE_TICK);
|
|
|
|
slot = (slot+1)&(TCP_TW_RECYCLE_SLOTS-1);
|
|
|
|
}
|
|
|
|
tcp_twcal_hand = -1;
|
|
|
|
|
|
|
|
out:
|
|
|
|
if ((tcp_tw_count -= killed) == 0)
|
|
|
|
del_timer(&tcp_tw_timer);
|
|
|
|
NET_ADD_STATS_BH(LINUX_MIB_TIMEWAITKILLED, killed);
|
|
|
|
spin_unlock(&tw_death_lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
/* This is not only more efficient than what we used to do, it eliminates
|
|
|
|
* a lot of code duplication between IPv4/IPv6 SYN recv processing. -DaveM
|
|
|
|
*
|
|
|
|
* Actually, we could lots of memory writes here. tp of listening
|
|
|
|
* socket contains all necessary default parameters.
|
|
|
|
*/
|
2005-06-18 22:47:21 -07:00
|
|
|
struct sock *tcp_create_openreq_child(struct sock *sk, struct request_sock *req, struct sk_buff *skb)
|
2005-04-16 15:20:36 -07:00
|
|
|
{
|
|
|
|
/* allocate the newsk from the same slab of the master sock,
|
|
|
|
* if not, at sk_free time we'll try to free it from the wrong
|
|
|
|
* slabcache (i.e. is it TCPv4 or v6?), this is handled thru sk->sk_prot -acme */
|
|
|
|
struct sock *newsk = sk_alloc(PF_INET, GFP_ATOMIC, sk->sk_prot, 0);
|
|
|
|
|
|
|
|
if(newsk != NULL) {
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
struct inet_request_sock *ireq = inet_rsk(req);
|
|
|
|
struct tcp_request_sock *treq = tcp_rsk(req);
|
2005-04-16 15:20:36 -07:00
|
|
|
struct tcp_sock *newtp;
|
|
|
|
struct sk_filter *filter;
|
|
|
|
|
|
|
|
memcpy(newsk, sk, sizeof(struct tcp_sock));
|
|
|
|
newsk->sk_state = TCP_SYN_RECV;
|
|
|
|
|
|
|
|
/* SANITY */
|
|
|
|
sk_node_init(&newsk->sk_node);
|
|
|
|
tcp_sk(newsk)->bind_hash = NULL;
|
|
|
|
|
|
|
|
/* Clone the TCP header template */
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
inet_sk(newsk)->dport = ireq->rmt_port;
|
2005-04-16 15:20:36 -07:00
|
|
|
|
|
|
|
sock_lock_init(newsk);
|
|
|
|
bh_lock_sock(newsk);
|
|
|
|
|
|
|
|
rwlock_init(&newsk->sk_dst_lock);
|
|
|
|
atomic_set(&newsk->sk_rmem_alloc, 0);
|
|
|
|
skb_queue_head_init(&newsk->sk_receive_queue);
|
|
|
|
atomic_set(&newsk->sk_wmem_alloc, 0);
|
|
|
|
skb_queue_head_init(&newsk->sk_write_queue);
|
|
|
|
atomic_set(&newsk->sk_omem_alloc, 0);
|
|
|
|
newsk->sk_wmem_queued = 0;
|
|
|
|
newsk->sk_forward_alloc = 0;
|
|
|
|
|
|
|
|
sock_reset_flag(newsk, SOCK_DONE);
|
|
|
|
newsk->sk_userlocks = sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
|
|
|
|
newsk->sk_backlog.head = newsk->sk_backlog.tail = NULL;
|
|
|
|
newsk->sk_send_head = NULL;
|
|
|
|
rwlock_init(&newsk->sk_callback_lock);
|
|
|
|
skb_queue_head_init(&newsk->sk_error_queue);
|
|
|
|
newsk->sk_write_space = sk_stream_write_space;
|
|
|
|
|
|
|
|
if ((filter = newsk->sk_filter) != NULL)
|
|
|
|
sk_filter_charge(newsk, filter);
|
|
|
|
|
|
|
|
if (unlikely(xfrm_sk_clone_policy(newsk))) {
|
|
|
|
/* It is still raw copy of parent, so invalidate
|
|
|
|
* destructor and make plain sk_free() */
|
|
|
|
newsk->sk_destruct = NULL;
|
|
|
|
sk_free(newsk);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Now setup tcp_sock */
|
|
|
|
newtp = tcp_sk(newsk);
|
|
|
|
newtp->pred_flags = 0;
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
newtp->rcv_nxt = treq->rcv_isn + 1;
|
|
|
|
newtp->snd_nxt = treq->snt_isn + 1;
|
|
|
|
newtp->snd_una = treq->snt_isn + 1;
|
|
|
|
newtp->snd_sml = treq->snt_isn + 1;
|
2005-04-16 15:20:36 -07:00
|
|
|
|
|
|
|
tcp_prequeue_init(newtp);
|
|
|
|
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
tcp_init_wl(newtp, treq->snt_isn, treq->rcv_isn);
|
2005-04-16 15:20:36 -07:00
|
|
|
|
|
|
|
newtp->retransmits = 0;
|
|
|
|
newtp->backoff = 0;
|
|
|
|
newtp->srtt = 0;
|
|
|
|
newtp->mdev = TCP_TIMEOUT_INIT;
|
|
|
|
newtp->rto = TCP_TIMEOUT_INIT;
|
|
|
|
|
|
|
|
newtp->packets_out = 0;
|
|
|
|
newtp->left_out = 0;
|
|
|
|
newtp->retrans_out = 0;
|
|
|
|
newtp->sacked_out = 0;
|
|
|
|
newtp->fackets_out = 0;
|
|
|
|
newtp->snd_ssthresh = 0x7fffffff;
|
|
|
|
|
|
|
|
/* 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
|
|
|
|
*/
|
|
|
|
newtp->snd_cwnd = 2;
|
|
|
|
newtp->snd_cwnd_cnt = 0;
|
|
|
|
|
|
|
|
newtp->frto_counter = 0;
|
|
|
|
newtp->frto_highmark = 0;
|
|
|
|
|
2005-06-23 12:19:55 -07:00
|
|
|
newtp->ca_ops = &tcp_reno;
|
|
|
|
|
2005-04-16 15:20:36 -07:00
|
|
|
tcp_set_ca_state(newtp, TCP_CA_Open);
|
|
|
|
tcp_init_xmit_timers(newsk);
|
|
|
|
skb_queue_head_init(&newtp->out_of_order_queue);
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
newtp->rcv_wup = treq->rcv_isn + 1;
|
|
|
|
newtp->write_seq = treq->snt_isn + 1;
|
2005-04-16 15:20:36 -07:00
|
|
|
newtp->pushed_seq = newtp->write_seq;
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
newtp->copied_seq = treq->rcv_isn + 1;
|
2005-04-16 15:20:36 -07:00
|
|
|
|
|
|
|
newtp->rx_opt.saw_tstamp = 0;
|
|
|
|
|
|
|
|
newtp->rx_opt.dsack = 0;
|
|
|
|
newtp->rx_opt.eff_sacks = 0;
|
|
|
|
|
|
|
|
newtp->probes_out = 0;
|
|
|
|
newtp->rx_opt.num_sacks = 0;
|
|
|
|
newtp->urg_data = 0;
|
2005-06-18 22:47:59 -07:00
|
|
|
/* Deinitialize accept_queue to trap illegal accesses. */
|
|
|
|
memset(&newtp->accept_queue, 0, sizeof(newtp->accept_queue));
|
2005-04-16 15:20:36 -07:00
|
|
|
|
|
|
|
/* Back to base struct sock members. */
|
|
|
|
newsk->sk_err = 0;
|
|
|
|
newsk->sk_priority = 0;
|
|
|
|
atomic_set(&newsk->sk_refcnt, 2);
|
|
|
|
#ifdef INET_REFCNT_DEBUG
|
|
|
|
atomic_inc(&inet_sock_nr);
|
|
|
|
#endif
|
|
|
|
atomic_inc(&tcp_sockets_allocated);
|
|
|
|
|
|
|
|
if (sock_flag(newsk, SOCK_KEEPOPEN))
|
|
|
|
tcp_reset_keepalive_timer(newsk,
|
|
|
|
keepalive_time_when(newtp));
|
|
|
|
newsk->sk_socket = NULL;
|
|
|
|
newsk->sk_sleep = NULL;
|
|
|
|
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
newtp->rx_opt.tstamp_ok = ireq->tstamp_ok;
|
|
|
|
if((newtp->rx_opt.sack_ok = ireq->sack_ok) != 0) {
|
2005-04-16 15:20:36 -07:00
|
|
|
if (sysctl_tcp_fack)
|
|
|
|
newtp->rx_opt.sack_ok |= 2;
|
|
|
|
}
|
|
|
|
newtp->window_clamp = req->window_clamp;
|
|
|
|
newtp->rcv_ssthresh = req->rcv_wnd;
|
|
|
|
newtp->rcv_wnd = req->rcv_wnd;
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
newtp->rx_opt.wscale_ok = ireq->wscale_ok;
|
2005-04-16 15:20:36 -07:00
|
|
|
if (newtp->rx_opt.wscale_ok) {
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
newtp->rx_opt.snd_wscale = ireq->snd_wscale;
|
|
|
|
newtp->rx_opt.rcv_wscale = ireq->rcv_wscale;
|
2005-04-16 15:20:36 -07:00
|
|
|
} else {
|
|
|
|
newtp->rx_opt.snd_wscale = newtp->rx_opt.rcv_wscale = 0;
|
|
|
|
newtp->window_clamp = min(newtp->window_clamp, 65535U);
|
|
|
|
}
|
|
|
|
newtp->snd_wnd = ntohs(skb->h.th->window) << newtp->rx_opt.snd_wscale;
|
|
|
|
newtp->max_window = newtp->snd_wnd;
|
|
|
|
|
|
|
|
if (newtp->rx_opt.tstamp_ok) {
|
|
|
|
newtp->rx_opt.ts_recent = req->ts_recent;
|
|
|
|
newtp->rx_opt.ts_recent_stamp = xtime.tv_sec;
|
|
|
|
newtp->tcp_header_len = sizeof(struct tcphdr) + TCPOLEN_TSTAMP_ALIGNED;
|
|
|
|
} else {
|
|
|
|
newtp->rx_opt.ts_recent_stamp = 0;
|
|
|
|
newtp->tcp_header_len = sizeof(struct tcphdr);
|
|
|
|
}
|
|
|
|
if (skb->len >= TCP_MIN_RCVMSS+newtp->tcp_header_len)
|
|
|
|
newtp->ack.last_seg_size = skb->len-newtp->tcp_header_len;
|
|
|
|
newtp->rx_opt.mss_clamp = req->mss;
|
|
|
|
TCP_ECN_openreq_child(newtp, req);
|
|
|
|
if (newtp->ecn_flags&TCP_ECN_OK)
|
|
|
|
sock_set_flag(newsk, SOCK_NO_LARGESEND);
|
|
|
|
|
|
|
|
TCP_INC_STATS_BH(TCP_MIB_PASSIVEOPENS);
|
|
|
|
}
|
|
|
|
return newsk;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Process an incoming packet for SYN_RECV sockets represented
|
2005-06-18 22:47:21 -07:00
|
|
|
* as a request_sock.
|
2005-04-16 15:20:36 -07:00
|
|
|
*/
|
|
|
|
|
|
|
|
struct sock *tcp_check_req(struct sock *sk,struct sk_buff *skb,
|
2005-06-18 22:47:21 -07:00
|
|
|
struct request_sock *req,
|
|
|
|
struct request_sock **prev)
|
2005-04-16 15:20:36 -07:00
|
|
|
{
|
|
|
|
struct tcphdr *th = skb->h.th;
|
|
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
u32 flg = tcp_flag_word(th) & (TCP_FLAG_RST|TCP_FLAG_SYN|TCP_FLAG_ACK);
|
|
|
|
int paws_reject = 0;
|
|
|
|
struct tcp_options_received tmp_opt;
|
|
|
|
struct sock *child;
|
|
|
|
|
|
|
|
tmp_opt.saw_tstamp = 0;
|
|
|
|
if (th->doff > (sizeof(struct tcphdr)>>2)) {
|
|
|
|
tcp_parse_options(skb, &tmp_opt, 0);
|
|
|
|
|
|
|
|
if (tmp_opt.saw_tstamp) {
|
|
|
|
tmp_opt.ts_recent = req->ts_recent;
|
|
|
|
/* We do not store true stamp, but it is not required,
|
|
|
|
* it can be estimated (approximately)
|
|
|
|
* from another data.
|
|
|
|
*/
|
|
|
|
tmp_opt.ts_recent_stamp = xtime.tv_sec - ((TCP_TIMEOUT_INIT/HZ)<<req->retrans);
|
|
|
|
paws_reject = tcp_paws_check(&tmp_opt, th->rst);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Check for pure retransmitted SYN. */
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn &&
|
2005-04-16 15:20:36 -07:00
|
|
|
flg == TCP_FLAG_SYN &&
|
|
|
|
!paws_reject) {
|
|
|
|
/*
|
|
|
|
* RFC793 draws (Incorrectly! It was fixed in RFC1122)
|
|
|
|
* this case on figure 6 and figure 8, but formal
|
|
|
|
* protocol description says NOTHING.
|
|
|
|
* To be more exact, it says that we should send ACK,
|
|
|
|
* because this segment (at least, if it has no data)
|
|
|
|
* is out of window.
|
|
|
|
*
|
|
|
|
* CONCLUSION: RFC793 (even with RFC1122) DOES NOT
|
|
|
|
* describe SYN-RECV state. All the description
|
|
|
|
* is wrong, we cannot believe to it and should
|
|
|
|
* rely only on common sense and implementation
|
|
|
|
* experience.
|
|
|
|
*
|
|
|
|
* Enforce "SYN-ACK" according to figure 8, figure 6
|
|
|
|
* of RFC793, fixed by RFC1122.
|
|
|
|
*/
|
2005-06-18 22:47:21 -07:00
|
|
|
req->rsk_ops->rtx_syn_ack(sk, req, NULL);
|
2005-04-16 15:20:36 -07:00
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Further reproduces section "SEGMENT ARRIVES"
|
|
|
|
for state SYN-RECEIVED of RFC793.
|
|
|
|
It is broken, however, it does not work only
|
|
|
|
when SYNs are crossed.
|
|
|
|
|
|
|
|
You would think that SYN crossing is impossible here, since
|
|
|
|
we should have a SYN_SENT socket (from connect()) on our end,
|
|
|
|
but this is not true if the crossed SYNs were sent to both
|
|
|
|
ends by a malicious third party. We must defend against this,
|
|
|
|
and to do that we first verify the ACK (as per RFC793, page
|
|
|
|
36) and reset if it is invalid. Is this a true full defense?
|
|
|
|
To convince ourselves, let us consider a way in which the ACK
|
|
|
|
test can still pass in this 'malicious crossed SYNs' case.
|
|
|
|
Malicious sender sends identical SYNs (and thus identical sequence
|
|
|
|
numbers) to both A and B:
|
|
|
|
|
|
|
|
A: gets SYN, seq=7
|
|
|
|
B: gets SYN, seq=7
|
|
|
|
|
|
|
|
By our good fortune, both A and B select the same initial
|
|
|
|
send sequence number of seven :-)
|
|
|
|
|
|
|
|
A: sends SYN|ACK, seq=7, ack_seq=8
|
|
|
|
B: sends SYN|ACK, seq=7, ack_seq=8
|
|
|
|
|
|
|
|
So we are now A eating this SYN|ACK, ACK test passes. So
|
|
|
|
does sequence test, SYN is truncated, and thus we consider
|
|
|
|
it a bare ACK.
|
|
|
|
|
|
|
|
If tp->defer_accept, we silently drop this bare ACK. Otherwise,
|
|
|
|
we create an established connection. Both ends (listening sockets)
|
|
|
|
accept the new incoming connection and try to talk to each other. 8-)
|
|
|
|
|
|
|
|
Note: This case is both harmless, and rare. Possibility is about the
|
|
|
|
same as us discovering intelligent life on another plant tomorrow.
|
|
|
|
|
|
|
|
But generally, we should (RFC lies!) to accept ACK
|
|
|
|
from SYNACK both here and in tcp_rcv_state_process().
|
|
|
|
tcp_rcv_state_process() does not, hence, we do not too.
|
|
|
|
|
|
|
|
Note that the case is absolutely generic:
|
|
|
|
we cannot optimize anything here without
|
|
|
|
violating protocol. All the checks must be made
|
|
|
|
before attempt to create socket.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/* RFC793 page 36: "If the connection is in any non-synchronized state ...
|
|
|
|
* and the incoming segment acknowledges something not yet
|
|
|
|
* sent (the segment carries an unaccaptable ACK) ...
|
|
|
|
* a reset is sent."
|
|
|
|
*
|
|
|
|
* Invalid ACK: reset will be sent by listening socket
|
|
|
|
*/
|
|
|
|
if ((flg & TCP_FLAG_ACK) &&
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
(TCP_SKB_CB(skb)->ack_seq != tcp_rsk(req)->snt_isn + 1))
|
2005-04-16 15:20:36 -07:00
|
|
|
return sk;
|
|
|
|
|
|
|
|
/* Also, it would be not so bad idea to check rcv_tsecr, which
|
|
|
|
* is essentially ACK extension and too early or too late values
|
|
|
|
* should cause reset in unsynchronized states.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/* RFC793: "first check sequence number". */
|
|
|
|
|
|
|
|
if (paws_reject || !tcp_in_window(TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq,
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
tcp_rsk(req)->rcv_isn + 1, tcp_rsk(req)->rcv_isn + 1 + req->rcv_wnd)) {
|
2005-04-16 15:20:36 -07:00
|
|
|
/* Out of window: send ACK and drop. */
|
|
|
|
if (!(flg & TCP_FLAG_RST))
|
2005-06-18 22:47:21 -07:00
|
|
|
req->rsk_ops->send_ack(skb, req);
|
2005-04-16 15:20:36 -07:00
|
|
|
if (paws_reject)
|
|
|
|
NET_INC_STATS_BH(LINUX_MIB_PAWSESTABREJECTED);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* In sequence, PAWS is OK. */
|
|
|
|
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
if (tmp_opt.saw_tstamp && !after(TCP_SKB_CB(skb)->seq, tcp_rsk(req)->rcv_isn + 1))
|
2005-04-16 15:20:36 -07:00
|
|
|
req->ts_recent = tmp_opt.rcv_tsval;
|
|
|
|
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
if (TCP_SKB_CB(skb)->seq == tcp_rsk(req)->rcv_isn) {
|
2005-04-16 15:20:36 -07:00
|
|
|
/* Truncate SYN, it is out of window starting
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
at tcp_rsk(req)->rcv_isn + 1. */
|
2005-04-16 15:20:36 -07:00
|
|
|
flg &= ~TCP_FLAG_SYN;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* RFC793: "second check the RST bit" and
|
|
|
|
* "fourth, check the SYN bit"
|
|
|
|
*/
|
|
|
|
if (flg & (TCP_FLAG_RST|TCP_FLAG_SYN))
|
|
|
|
goto embryonic_reset;
|
|
|
|
|
|
|
|
/* ACK sequence verified above, just make sure ACK is
|
|
|
|
* set. If ACK not set, just silently drop the packet.
|
|
|
|
*/
|
|
|
|
if (!(flg & TCP_FLAG_ACK))
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
/* If TCP_DEFER_ACCEPT is set, drop bare ACK. */
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
if (tp->defer_accept && TCP_SKB_CB(skb)->end_seq == tcp_rsk(req)->rcv_isn + 1) {
|
|
|
|
inet_rsk(req)->acked = 1;
|
2005-04-16 15:20:36 -07:00
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* OK, ACK is valid, create big socket and
|
|
|
|
* feed this segment to it. It will repeat all
|
|
|
|
* the tests. THIS SEGMENT MUST MOVE SOCKET TO
|
|
|
|
* ESTABLISHED STATE. If it will be dropped after
|
|
|
|
* socket is created, wait for troubles.
|
|
|
|
*/
|
|
|
|
child = tp->af_specific->syn_recv_sock(sk, skb, req, NULL);
|
|
|
|
if (child == NULL)
|
|
|
|
goto listen_overflow;
|
|
|
|
|
|
|
|
tcp_synq_unlink(tp, req, prev);
|
|
|
|
tcp_synq_removed(sk, req);
|
|
|
|
|
|
|
|
tcp_acceptq_queue(sk, req, child);
|
|
|
|
return child;
|
|
|
|
|
|
|
|
listen_overflow:
|
|
|
|
if (!sysctl_tcp_abort_on_overflow) {
|
[NET] Generalise TCP's struct open_request minisock infrastructure
Kept this first changeset minimal, without changing existing names to
ease peer review.
Basicaly tcp_openreq_alloc now receives the or_calltable, that in turn
has two new members:
->slab, that replaces tcp_openreq_cachep
->obj_size, to inform the size of the openreq descendant for
a specific protocol
The protocol specific fields in struct open_request were moved to a
class hierarchy, with the things that are common to all connection
oriented PF_INET protocols in struct inet_request_sock, the TCP ones
in tcp_request_sock, that is an inet_request_sock, that is an
open_request.
I.e. this uses the same approach used for the struct sock class
hierarchy, with sk_prot indicating if the protocol wants to use the
open_request infrastructure by filling in sk_prot->rsk_prot with an
or_calltable.
Results? Performance is improved and TCP v4 now uses only 64 bytes per
open request minisock, down from 96 without this patch :-)
Next changeset will rename some of the structs, fields and functions
mentioned above, struct or_calltable is way unclear, better name it
struct request_sock_ops, s/struct open_request/struct request_sock/g,
etc.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-18 22:46:52 -07:00
|
|
|
inet_rsk(req)->acked = 1;
|
2005-04-16 15:20:36 -07:00
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
embryonic_reset:
|
|
|
|
NET_INC_STATS_BH(LINUX_MIB_EMBRYONICRSTS);
|
|
|
|
if (!(flg & TCP_FLAG_RST))
|
2005-06-18 22:47:21 -07:00
|
|
|
req->rsk_ops->send_reset(skb);
|
2005-04-16 15:20:36 -07:00
|
|
|
|
|
|
|
tcp_synq_drop(sk, req, prev);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Queue segment on the new socket if the new socket is active,
|
|
|
|
* otherwise we just shortcircuit this and continue with
|
|
|
|
* the new socket.
|
|
|
|
*/
|
|
|
|
|
|
|
|
int tcp_child_process(struct sock *parent, struct sock *child,
|
|
|
|
struct sk_buff *skb)
|
|
|
|
{
|
|
|
|
int ret = 0;
|
|
|
|
int state = child->sk_state;
|
|
|
|
|
|
|
|
if (!sock_owned_by_user(child)) {
|
|
|
|
ret = tcp_rcv_state_process(child, skb, skb->h.th, skb->len);
|
|
|
|
|
|
|
|
/* Wakeup parent, send SIGIO */
|
|
|
|
if (state == TCP_SYN_RECV && child->sk_state != state)
|
|
|
|
parent->sk_data_ready(parent, 0);
|
|
|
|
} else {
|
|
|
|
/* Alas, it is possible again, because we do lookup
|
|
|
|
* in main socket hash table and lock on listening
|
|
|
|
* socket does not protect us more.
|
|
|
|
*/
|
|
|
|
sk_add_backlog(child, skb);
|
|
|
|
}
|
|
|
|
|
|
|
|
bh_unlock_sock(child);
|
|
|
|
sock_put(child);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
EXPORT_SYMBOL(tcp_check_req);
|
|
|
|
EXPORT_SYMBOL(tcp_child_process);
|
|
|
|
EXPORT_SYMBOL(tcp_create_openreq_child);
|
|
|
|
EXPORT_SYMBOL(tcp_timewait_state_process);
|
|
|
|
EXPORT_SYMBOL(tcp_tw_deschedule);
|