1018 lines
29 KiB
C
1018 lines
29 KiB
C
/*-
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* Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)tcp_timer.c 8.2 (Berkeley) 5/24/95
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_inet.h"
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#include "opt_inet6.h"
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#include "opt_tcpdebug.h"
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#include "opt_rss.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mbuf.h>
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#include <sys/mutex.h>
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#include <sys/protosw.h>
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#include <sys/smp.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/sysctl.h>
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#include <sys/systm.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <net/rss_config.h>
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#include <net/vnet.h>
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#include <net/netisr.h>
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#include <netinet/in.h>
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#include <netinet/in_kdtrace.h>
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#include <netinet/in_pcb.h>
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#include <netinet/in_rss.h>
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#include <netinet/in_systm.h>
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#ifdef INET6
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#include <netinet6/in6_pcb.h>
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#endif
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#include <netinet/ip_var.h>
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#include <netinet/tcp.h>
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#include <netinet/tcp_fsm.h>
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#include <netinet/tcp_timer.h>
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#include <netinet/tcp_var.h>
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#include <netinet/cc/cc.h>
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#ifdef INET6
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#include <netinet6/tcp6_var.h>
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#endif
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#include <netinet/tcpip.h>
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#ifdef TCPDEBUG
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#include <netinet/tcp_debug.h>
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#endif
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int tcp_persmin;
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SYSCTL_PROC(_net_inet_tcp, OID_AUTO, persmin, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_persmin, 0, sysctl_msec_to_ticks, "I", "minimum persistence interval");
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int tcp_persmax;
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SYSCTL_PROC(_net_inet_tcp, OID_AUTO, persmax, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_persmax, 0, sysctl_msec_to_ticks, "I", "maximum persistence interval");
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int tcp_keepinit;
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SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINIT, keepinit, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_keepinit, 0, sysctl_msec_to_ticks, "I", "time to establish connection");
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int tcp_keepidle;
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SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPIDLE, keepidle, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_keepidle, 0, sysctl_msec_to_ticks, "I", "time before keepalive probes begin");
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int tcp_keepintvl;
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SYSCTL_PROC(_net_inet_tcp, TCPCTL_KEEPINTVL, keepintvl, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_keepintvl, 0, sysctl_msec_to_ticks, "I", "time between keepalive probes");
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int tcp_delacktime;
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SYSCTL_PROC(_net_inet_tcp, TCPCTL_DELACKTIME, delacktime, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_delacktime, 0, sysctl_msec_to_ticks, "I",
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"Time before a delayed ACK is sent");
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int tcp_msl;
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SYSCTL_PROC(_net_inet_tcp, OID_AUTO, msl, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_msl, 0, sysctl_msec_to_ticks, "I", "Maximum segment lifetime");
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int tcp_rexmit_min;
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SYSCTL_PROC(_net_inet_tcp, OID_AUTO, rexmit_min, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_rexmit_min, 0, sysctl_msec_to_ticks, "I",
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"Minimum Retransmission Timeout");
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int tcp_rexmit_slop;
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SYSCTL_PROC(_net_inet_tcp, OID_AUTO, rexmit_slop, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_rexmit_slop, 0, sysctl_msec_to_ticks, "I",
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"Retransmission Timer Slop");
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static int always_keepalive = 1;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, always_keepalive, CTLFLAG_RW,
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&always_keepalive , 0, "Assume SO_KEEPALIVE on all TCP connections");
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int tcp_fast_finwait2_recycle = 0;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, fast_finwait2_recycle, CTLFLAG_RW,
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&tcp_fast_finwait2_recycle, 0,
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"Recycle closed FIN_WAIT_2 connections faster");
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int tcp_finwait2_timeout;
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SYSCTL_PROC(_net_inet_tcp, OID_AUTO, finwait2_timeout, CTLTYPE_INT|CTLFLAG_RW,
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&tcp_finwait2_timeout, 0, sysctl_msec_to_ticks, "I", "FIN-WAIT2 timeout");
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int tcp_keepcnt = TCPTV_KEEPCNT;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, keepcnt, CTLFLAG_RW, &tcp_keepcnt, 0,
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"Number of keepalive probes to send");
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/* max idle probes */
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int tcp_maxpersistidle;
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static int tcp_rexmit_drop_options = 0;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, rexmit_drop_options, CTLFLAG_RW,
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&tcp_rexmit_drop_options, 0,
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"Drop TCP options from 3rd and later retransmitted SYN");
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static VNET_DEFINE(int, tcp_pmtud_blackhole_detect);
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#define V_tcp_pmtud_blackhole_detect VNET(tcp_pmtud_blackhole_detect)
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_detection,
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CTLFLAG_RW|CTLFLAG_VNET,
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&VNET_NAME(tcp_pmtud_blackhole_detect), 0,
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"Path MTU Discovery Black Hole Detection Enabled");
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static VNET_DEFINE(int, tcp_pmtud_blackhole_activated);
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#define V_tcp_pmtud_blackhole_activated \
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VNET(tcp_pmtud_blackhole_activated)
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_activated,
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CTLFLAG_RD|CTLFLAG_VNET,
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&VNET_NAME(tcp_pmtud_blackhole_activated), 0,
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"Path MTU Discovery Black Hole Detection, Activation Count");
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static VNET_DEFINE(int, tcp_pmtud_blackhole_activated_min_mss);
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#define V_tcp_pmtud_blackhole_activated_min_mss \
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VNET(tcp_pmtud_blackhole_activated_min_mss)
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_activated_min_mss,
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CTLFLAG_RD|CTLFLAG_VNET,
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&VNET_NAME(tcp_pmtud_blackhole_activated_min_mss), 0,
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"Path MTU Discovery Black Hole Detection, Activation Count at min MSS");
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static VNET_DEFINE(int, tcp_pmtud_blackhole_failed);
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#define V_tcp_pmtud_blackhole_failed VNET(tcp_pmtud_blackhole_failed)
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_failed,
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CTLFLAG_RD|CTLFLAG_VNET,
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&VNET_NAME(tcp_pmtud_blackhole_failed), 0,
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"Path MTU Discovery Black Hole Detection, Failure Count");
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#ifdef INET
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static VNET_DEFINE(int, tcp_pmtud_blackhole_mss) = 1200;
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#define V_tcp_pmtud_blackhole_mss VNET(tcp_pmtud_blackhole_mss)
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, pmtud_blackhole_mss,
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CTLFLAG_RW|CTLFLAG_VNET,
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&VNET_NAME(tcp_pmtud_blackhole_mss), 0,
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"Path MTU Discovery Black Hole Detection lowered MSS");
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#endif
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#ifdef INET6
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static VNET_DEFINE(int, tcp_v6pmtud_blackhole_mss) = 1220;
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#define V_tcp_v6pmtud_blackhole_mss VNET(tcp_v6pmtud_blackhole_mss)
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, v6pmtud_blackhole_mss,
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CTLFLAG_RW|CTLFLAG_VNET,
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&VNET_NAME(tcp_v6pmtud_blackhole_mss), 0,
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"Path MTU Discovery IPv6 Black Hole Detection lowered MSS");
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#endif
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#ifdef RSS
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static int per_cpu_timers = 1;
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#else
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static int per_cpu_timers = 0;
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#endif
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, per_cpu_timers, CTLFLAG_RW,
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&per_cpu_timers , 0, "run tcp timers on all cpus");
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#if 0
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#define INP_CPU(inp) (per_cpu_timers ? (!CPU_ABSENT(((inp)->inp_flowid % (mp_maxid+1))) ? \
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((inp)->inp_flowid % (mp_maxid+1)) : curcpu) : 0)
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#endif
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/*
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* Map the given inp to a CPU id.
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*
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* This queries RSS if it's compiled in, else it defaults to the current
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* CPU ID.
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*/
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static inline int
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inp_to_cpuid(struct inpcb *inp)
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{
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u_int cpuid;
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#ifdef RSS
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if (per_cpu_timers) {
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cpuid = rss_hash2cpuid(inp->inp_flowid, inp->inp_flowtype);
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if (cpuid == NETISR_CPUID_NONE)
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return (curcpu); /* XXX */
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else
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return (cpuid);
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}
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#else
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/* Legacy, pre-RSS behaviour */
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if (per_cpu_timers) {
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/*
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* We don't have a flowid -> cpuid mapping, so cheat and
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* just map unknown cpuids to curcpu. Not the best, but
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* apparently better than defaulting to swi 0.
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*/
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cpuid = inp->inp_flowid % (mp_maxid + 1);
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if (! CPU_ABSENT(cpuid))
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return (cpuid);
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return (curcpu);
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}
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#endif
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/* Default for RSS and non-RSS - cpuid 0 */
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else {
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return (0);
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}
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}
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/*
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* Tcp protocol timeout routine called every 500 ms.
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* Updates timestamps used for TCP
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* causes finite state machine actions if timers expire.
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*/
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void
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tcp_slowtimo(void)
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{
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VNET_ITERATOR_DECL(vnet_iter);
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VNET_LIST_RLOCK_NOSLEEP();
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VNET_FOREACH(vnet_iter) {
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CURVNET_SET(vnet_iter);
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(void) tcp_tw_2msl_scan(0);
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CURVNET_RESTORE();
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}
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VNET_LIST_RUNLOCK_NOSLEEP();
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}
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int tcp_syn_backoff[TCP_MAXRXTSHIFT + 1] =
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{ 1, 1, 1, 1, 1, 2, 4, 8, 16, 32, 64, 64, 64 };
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int tcp_backoff[TCP_MAXRXTSHIFT + 1] =
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{ 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 512, 512, 512 };
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static int tcp_totbackoff = 2559; /* sum of tcp_backoff[] */
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/*
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* TCP timer processing.
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*/
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void
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tcp_timer_delack(void *xtp)
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{
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struct tcpcb *tp = xtp;
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struct inpcb *inp;
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CURVNET_SET(tp->t_vnet);
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inp = tp->t_inpcb;
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KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
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INP_WLOCK(inp);
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if (callout_pending(&tp->t_timers->tt_delack) ||
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!callout_active(&tp->t_timers->tt_delack)) {
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INP_WUNLOCK(inp);
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CURVNET_RESTORE();
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return;
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}
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callout_deactivate(&tp->t_timers->tt_delack);
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if ((inp->inp_flags & INP_DROPPED) != 0) {
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INP_WUNLOCK(inp);
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CURVNET_RESTORE();
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return;
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}
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tp->t_flags |= TF_ACKNOW;
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TCPSTAT_INC(tcps_delack);
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(void) tp->t_fb->tfb_tcp_output(tp);
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INP_WUNLOCK(inp);
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CURVNET_RESTORE();
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}
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/*
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* When a timer wants to remove a TCB it must
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* hold the INP_INFO_RLOCK(). The timer function
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* should only have grabbed the INP_WLOCK() when
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* it entered. To safely switch to holding both the
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* INP_INFO_RLOCK() and the INP_WLOCK() we must first
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* grab a reference on the inp, which will hold the inp
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* so that it can't be removed. We then unlock the INP_WLOCK(),
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* and grab the INP_INFO_RLOCK() lock. Once we have the INP_INFO_RLOCK()
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* we proceed again to get the INP_WLOCK() (this preserves proper
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* lock order). After acquiring the INP_WLOCK we must check if someone
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* else deleted the pcb i.e. the inp_flags check.
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* If so we return 1 otherwise we return 0.
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*
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* No matter what the tcp_inpinfo_lock_add() function
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* returns the caller must afterwards call tcp_inpinfo_lock_del()
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* to drop the locks and reference properly.
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*/
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int
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tcp_inpinfo_lock_add(struct inpcb *inp)
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{
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in_pcbref(inp);
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INP_WUNLOCK(inp);
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INP_INFO_RLOCK(&V_tcbinfo);
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INP_WLOCK(inp);
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if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
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return(1);
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}
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return(0);
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}
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void
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tcp_inpinfo_lock_del(struct inpcb *inp, struct tcpcb *tp)
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{
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INP_INFO_RUNLOCK(&V_tcbinfo);
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if (inp && (tp == NULL)) {
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/*
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* If tcp_close/drop() gets called and tp
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* returns NULL, then the function dropped
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* the inp lock, we hold a reference keeping
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* this around, so we must re-aquire the
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* INP_WLOCK() in order to proceed with
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* our dropping the inp reference.
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*/
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INP_WLOCK(inp);
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}
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if (inp && in_pcbrele_wlocked(inp) == 0)
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INP_WUNLOCK(inp);
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}
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void
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tcp_timer_2msl(void *xtp)
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{
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struct tcpcb *tp = xtp;
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struct inpcb *inp;
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CURVNET_SET(tp->t_vnet);
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#ifdef TCPDEBUG
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int ostate;
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ostate = tp->t_state;
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#endif
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inp = tp->t_inpcb;
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KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
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INP_WLOCK(inp);
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tcp_free_sackholes(tp);
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if (callout_pending(&tp->t_timers->tt_2msl) ||
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!callout_active(&tp->t_timers->tt_2msl)) {
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INP_WUNLOCK(tp->t_inpcb);
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CURVNET_RESTORE();
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return;
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}
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callout_deactivate(&tp->t_timers->tt_2msl);
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if ((inp->inp_flags & INP_DROPPED) != 0) {
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INP_WUNLOCK(inp);
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CURVNET_RESTORE();
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return;
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}
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KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
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("%s: tp %p tcpcb can't be stopped here", __func__, tp));
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/*
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* 2 MSL timeout in shutdown went off. If we're closed but
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* still waiting for peer to close and connection has been idle
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* too long delete connection control block. Otherwise, check
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* again in a bit.
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*
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* If in TIME_WAIT state just ignore as this timeout is handled in
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* tcp_tw_2msl_scan().
|
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*
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* If fastrecycle of FIN_WAIT_2, in FIN_WAIT_2 and receiver has closed,
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* there's no point in hanging onto FIN_WAIT_2 socket. Just close it.
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* Ignore fact that there were recent incoming segments.
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*/
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if ((inp->inp_flags & INP_TIMEWAIT) != 0) {
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INP_WUNLOCK(inp);
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CURVNET_RESTORE();
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return;
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}
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if (tcp_fast_finwait2_recycle && tp->t_state == TCPS_FIN_WAIT_2 &&
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tp->t_inpcb && tp->t_inpcb->inp_socket &&
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(tp->t_inpcb->inp_socket->so_rcv.sb_state & SBS_CANTRCVMORE)) {
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TCPSTAT_INC(tcps_finwait2_drops);
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if (tcp_inpinfo_lock_add(inp)) {
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tcp_inpinfo_lock_del(inp, tp);
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goto out;
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}
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tp = tcp_close(tp);
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tcp_inpinfo_lock_del(inp, tp);
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goto out;
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} else {
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if (ticks - tp->t_rcvtime <= TP_MAXIDLE(tp)) {
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callout_reset(&tp->t_timers->tt_2msl,
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TP_KEEPINTVL(tp), tcp_timer_2msl, tp);
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} else {
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if (tcp_inpinfo_lock_add(inp)) {
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tcp_inpinfo_lock_del(inp, tp);
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goto out;
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}
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tp = tcp_close(tp);
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tcp_inpinfo_lock_del(inp, tp);
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goto out;
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}
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}
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#ifdef TCPDEBUG
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if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
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tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
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PRU_SLOWTIMO);
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#endif
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|
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
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|
|
if (tp != NULL)
|
|
INP_WUNLOCK(inp);
|
|
out:
|
|
CURVNET_RESTORE();
|
|
}
|
|
|
|
void
|
|
tcp_timer_keep(void *xtp)
|
|
{
|
|
struct tcpcb *tp = xtp;
|
|
struct tcptemp *t_template;
|
|
struct inpcb *inp;
|
|
CURVNET_SET(tp->t_vnet);
|
|
#ifdef TCPDEBUG
|
|
int ostate;
|
|
|
|
ostate = tp->t_state;
|
|
#endif
|
|
inp = tp->t_inpcb;
|
|
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
|
|
INP_WLOCK(inp);
|
|
if (callout_pending(&tp->t_timers->tt_keep) ||
|
|
!callout_active(&tp->t_timers->tt_keep)) {
|
|
INP_WUNLOCK(inp);
|
|
CURVNET_RESTORE();
|
|
return;
|
|
}
|
|
callout_deactivate(&tp->t_timers->tt_keep);
|
|
if ((inp->inp_flags & INP_DROPPED) != 0) {
|
|
INP_WUNLOCK(inp);
|
|
CURVNET_RESTORE();
|
|
return;
|
|
}
|
|
KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
|
|
("%s: tp %p tcpcb can't be stopped here", __func__, tp));
|
|
/*
|
|
* Keep-alive timer went off; send something
|
|
* or drop connection if idle for too long.
|
|
*/
|
|
TCPSTAT_INC(tcps_keeptimeo);
|
|
if (tp->t_state < TCPS_ESTABLISHED)
|
|
goto dropit;
|
|
if ((always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
|
|
tp->t_state <= TCPS_CLOSING) {
|
|
if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
|
|
goto dropit;
|
|
/*
|
|
* Send a packet designed to force a response
|
|
* if the peer is up and reachable:
|
|
* either an ACK if the connection is still alive,
|
|
* or an RST if the peer has closed the connection
|
|
* due to timeout or reboot.
|
|
* Using sequence number tp->snd_una-1
|
|
* causes the transmitted zero-length segment
|
|
* to lie outside the receive window;
|
|
* by the protocol spec, this requires the
|
|
* correspondent TCP to respond.
|
|
*/
|
|
TCPSTAT_INC(tcps_keepprobe);
|
|
t_template = tcpip_maketemplate(inp);
|
|
if (t_template) {
|
|
tcp_respond(tp, t_template->tt_ipgen,
|
|
&t_template->tt_t, (struct mbuf *)NULL,
|
|
tp->rcv_nxt, tp->snd_una - 1, 0);
|
|
free(t_template, M_TEMP);
|
|
}
|
|
callout_reset(&tp->t_timers->tt_keep, TP_KEEPINTVL(tp),
|
|
tcp_timer_keep, tp);
|
|
} else
|
|
callout_reset(&tp->t_timers->tt_keep, TP_KEEPIDLE(tp),
|
|
tcp_timer_keep, tp);
|
|
|
|
#ifdef TCPDEBUG
|
|
if (inp->inp_socket->so_options & SO_DEBUG)
|
|
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
|
|
PRU_SLOWTIMO);
|
|
#endif
|
|
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
|
|
INP_WUNLOCK(inp);
|
|
CURVNET_RESTORE();
|
|
return;
|
|
|
|
dropit:
|
|
TCPSTAT_INC(tcps_keepdrops);
|
|
|
|
if (tcp_inpinfo_lock_add(inp)) {
|
|
tcp_inpinfo_lock_del(inp, tp);
|
|
goto out;
|
|
}
|
|
tp = tcp_drop(tp, ETIMEDOUT);
|
|
|
|
#ifdef TCPDEBUG
|
|
if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
|
|
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
|
|
PRU_SLOWTIMO);
|
|
#endif
|
|
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
|
|
tcp_inpinfo_lock_del(inp, tp);
|
|
out:
|
|
CURVNET_RESTORE();
|
|
}
|
|
|
|
void
|
|
tcp_timer_persist(void *xtp)
|
|
{
|
|
struct tcpcb *tp = xtp;
|
|
struct inpcb *inp;
|
|
CURVNET_SET(tp->t_vnet);
|
|
#ifdef TCPDEBUG
|
|
int ostate;
|
|
|
|
ostate = tp->t_state;
|
|
#endif
|
|
inp = tp->t_inpcb;
|
|
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
|
|
INP_WLOCK(inp);
|
|
if (callout_pending(&tp->t_timers->tt_persist) ||
|
|
!callout_active(&tp->t_timers->tt_persist)) {
|
|
INP_WUNLOCK(inp);
|
|
CURVNET_RESTORE();
|
|
return;
|
|
}
|
|
callout_deactivate(&tp->t_timers->tt_persist);
|
|
if ((inp->inp_flags & INP_DROPPED) != 0) {
|
|
INP_WUNLOCK(inp);
|
|
CURVNET_RESTORE();
|
|
return;
|
|
}
|
|
KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
|
|
("%s: tp %p tcpcb can't be stopped here", __func__, tp));
|
|
/*
|
|
* Persistence timer into zero window.
|
|
* Force a byte to be output, if possible.
|
|
*/
|
|
TCPSTAT_INC(tcps_persisttimeo);
|
|
/*
|
|
* Hack: if the peer is dead/unreachable, we do not
|
|
* time out if the window is closed. After a full
|
|
* backoff, drop the connection if the idle time
|
|
* (no responses to probes) reaches the maximum
|
|
* backoff that we would use if retransmitting.
|
|
*/
|
|
if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
|
|
(ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
|
|
ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
|
|
TCPSTAT_INC(tcps_persistdrop);
|
|
if (tcp_inpinfo_lock_add(inp)) {
|
|
tcp_inpinfo_lock_del(inp, tp);
|
|
goto out;
|
|
}
|
|
tp = tcp_drop(tp, ETIMEDOUT);
|
|
tcp_inpinfo_lock_del(inp, tp);
|
|
goto out;
|
|
}
|
|
/*
|
|
* If the user has closed the socket then drop a persisting
|
|
* connection after a much reduced timeout.
|
|
*/
|
|
if (tp->t_state > TCPS_CLOSE_WAIT &&
|
|
(ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
|
|
TCPSTAT_INC(tcps_persistdrop);
|
|
if (tcp_inpinfo_lock_add(inp)) {
|
|
tcp_inpinfo_lock_del(inp, tp);
|
|
goto out;
|
|
}
|
|
tp = tcp_drop(tp, ETIMEDOUT);
|
|
tcp_inpinfo_lock_del(inp, tp);
|
|
goto out;
|
|
}
|
|
tcp_setpersist(tp);
|
|
tp->t_flags |= TF_FORCEDATA;
|
|
(void) tp->t_fb->tfb_tcp_output(tp);
|
|
tp->t_flags &= ~TF_FORCEDATA;
|
|
|
|
#ifdef TCPDEBUG
|
|
if (tp != NULL && tp->t_inpcb->inp_socket->so_options & SO_DEBUG)
|
|
tcp_trace(TA_USER, ostate, tp, NULL, NULL, PRU_SLOWTIMO);
|
|
#endif
|
|
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
|
|
INP_WUNLOCK(inp);
|
|
out:
|
|
CURVNET_RESTORE();
|
|
}
|
|
|
|
void
|
|
tcp_timer_rexmt(void * xtp)
|
|
{
|
|
struct tcpcb *tp = xtp;
|
|
CURVNET_SET(tp->t_vnet);
|
|
int rexmt;
|
|
struct inpcb *inp;
|
|
#ifdef TCPDEBUG
|
|
int ostate;
|
|
|
|
ostate = tp->t_state;
|
|
#endif
|
|
inp = tp->t_inpcb;
|
|
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
|
|
INP_WLOCK(inp);
|
|
if (callout_pending(&tp->t_timers->tt_rexmt) ||
|
|
!callout_active(&tp->t_timers->tt_rexmt)) {
|
|
INP_WUNLOCK(inp);
|
|
CURVNET_RESTORE();
|
|
return;
|
|
}
|
|
callout_deactivate(&tp->t_timers->tt_rexmt);
|
|
if ((inp->inp_flags & INP_DROPPED) != 0) {
|
|
INP_WUNLOCK(inp);
|
|
CURVNET_RESTORE();
|
|
return;
|
|
}
|
|
KASSERT((tp->t_timers->tt_flags & TT_STOPPED) == 0,
|
|
("%s: tp %p tcpcb can't be stopped here", __func__, tp));
|
|
tcp_free_sackholes(tp);
|
|
if (tp->t_fb->tfb_tcp_rexmit_tmr) {
|
|
/* The stack has a timer action too. */
|
|
(*tp->t_fb->tfb_tcp_rexmit_tmr)(tp);
|
|
}
|
|
/*
|
|
* Retransmission timer went off. Message has not
|
|
* been acked within retransmit interval. Back off
|
|
* to a longer retransmit interval and retransmit one segment.
|
|
*/
|
|
if (++tp->t_rxtshift > TCP_MAXRXTSHIFT) {
|
|
tp->t_rxtshift = TCP_MAXRXTSHIFT;
|
|
TCPSTAT_INC(tcps_timeoutdrop);
|
|
if (tcp_inpinfo_lock_add(inp)) {
|
|
tcp_inpinfo_lock_del(inp, tp);
|
|
goto out;
|
|
}
|
|
tp = tcp_drop(tp, tp->t_softerror ?
|
|
tp->t_softerror : ETIMEDOUT);
|
|
tcp_inpinfo_lock_del(inp, tp);
|
|
goto out;
|
|
}
|
|
if (tp->t_state == TCPS_SYN_SENT) {
|
|
/*
|
|
* If the SYN was retransmitted, indicate CWND to be
|
|
* limited to 1 segment in cc_conn_init().
|
|
*/
|
|
tp->snd_cwnd = 1;
|
|
} else if (tp->t_rxtshift == 1) {
|
|
/*
|
|
* first retransmit; record ssthresh and cwnd so they can
|
|
* be recovered if this turns out to be a "bad" retransmit.
|
|
* A retransmit is considered "bad" if an ACK for this
|
|
* segment is received within RTT/2 interval; the assumption
|
|
* here is that the ACK was already in flight. See
|
|
* "On Estimating End-to-End Network Path Properties" by
|
|
* Allman and Paxson for more details.
|
|
*/
|
|
tp->snd_cwnd_prev = tp->snd_cwnd;
|
|
tp->snd_ssthresh_prev = tp->snd_ssthresh;
|
|
tp->snd_recover_prev = tp->snd_recover;
|
|
if (IN_FASTRECOVERY(tp->t_flags))
|
|
tp->t_flags |= TF_WASFRECOVERY;
|
|
else
|
|
tp->t_flags &= ~TF_WASFRECOVERY;
|
|
if (IN_CONGRECOVERY(tp->t_flags))
|
|
tp->t_flags |= TF_WASCRECOVERY;
|
|
else
|
|
tp->t_flags &= ~TF_WASCRECOVERY;
|
|
tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
|
|
tp->t_flags |= TF_PREVVALID;
|
|
} else
|
|
tp->t_flags &= ~TF_PREVVALID;
|
|
TCPSTAT_INC(tcps_rexmttimeo);
|
|
if ((tp->t_state == TCPS_SYN_SENT) ||
|
|
(tp->t_state == TCPS_SYN_RECEIVED))
|
|
rexmt = TCPTV_RTOBASE * tcp_syn_backoff[tp->t_rxtshift];
|
|
else
|
|
rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
|
|
TCPT_RANGESET(tp->t_rxtcur, rexmt,
|
|
tp->t_rttmin, TCPTV_REXMTMAX);
|
|
|
|
/*
|
|
* We enter the path for PLMTUD if connection is established or, if
|
|
* connection is FIN_WAIT_1 status, reason for the last is that if
|
|
* amount of data we send is very small, we could send it in couple of
|
|
* packets and process straight to FIN. In that case we won't catch
|
|
* ESTABLISHED state.
|
|
*/
|
|
if (V_tcp_pmtud_blackhole_detect && (((tp->t_state == TCPS_ESTABLISHED))
|
|
|| (tp->t_state == TCPS_FIN_WAIT_1))) {
|
|
#ifdef INET6
|
|
int isipv6;
|
|
#endif
|
|
|
|
/*
|
|
* Idea here is that at each stage of mtu probe (usually, 1448
|
|
* -> 1188 -> 524) should be given 2 chances to recover before
|
|
* further clamping down. 'tp->t_rxtshift % 2 == 0' should
|
|
* take care of that.
|
|
*/
|
|
if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD|TF2_PLPMTU_MAXSEGSNT)) ==
|
|
(TF2_PLPMTU_PMTUD|TF2_PLPMTU_MAXSEGSNT)) &&
|
|
(tp->t_rxtshift >= 2 && tp->t_rxtshift % 2 == 0)) {
|
|
/*
|
|
* Enter Path MTU Black-hole Detection mechanism:
|
|
* - Disable Path MTU Discovery (IP "DF" bit).
|
|
* - Reduce MTU to lower value than what we
|
|
* negotiated with peer.
|
|
*/
|
|
/* Record that we may have found a black hole. */
|
|
tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
|
|
|
|
/* Keep track of previous MSS. */
|
|
tp->t_pmtud_saved_maxseg = tp->t_maxseg;
|
|
|
|
/*
|
|
* Reduce the MSS to blackhole value or to the default
|
|
* in an attempt to retransmit.
|
|
*/
|
|
#ifdef INET6
|
|
isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? 1 : 0;
|
|
if (isipv6 &&
|
|
tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
|
|
/* Use the sysctl tuneable blackhole MSS. */
|
|
tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
|
|
V_tcp_pmtud_blackhole_activated++;
|
|
} else if (isipv6) {
|
|
/* Use the default MSS. */
|
|
tp->t_maxseg = V_tcp_v6mssdflt;
|
|
/*
|
|
* Disable Path MTU Discovery when we switch to
|
|
* minmss.
|
|
*/
|
|
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
|
|
V_tcp_pmtud_blackhole_activated_min_mss++;
|
|
}
|
|
#endif
|
|
#if defined(INET6) && defined(INET)
|
|
else
|
|
#endif
|
|
#ifdef INET
|
|
if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
|
|
/* Use the sysctl tuneable blackhole MSS. */
|
|
tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
|
|
V_tcp_pmtud_blackhole_activated++;
|
|
} else {
|
|
/* Use the default MSS. */
|
|
tp->t_maxseg = V_tcp_mssdflt;
|
|
/*
|
|
* Disable Path MTU Discovery when we switch to
|
|
* minmss.
|
|
*/
|
|
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
|
|
V_tcp_pmtud_blackhole_activated_min_mss++;
|
|
}
|
|
#endif
|
|
/*
|
|
* Reset the slow-start flight size
|
|
* as it may depend on the new MSS.
|
|
*/
|
|
if (CC_ALGO(tp)->conn_init != NULL)
|
|
CC_ALGO(tp)->conn_init(tp->ccv);
|
|
} else {
|
|
/*
|
|
* If further retransmissions are still unsuccessful
|
|
* with a lowered MTU, maybe this isn't a blackhole and
|
|
* we restore the previous MSS and blackhole detection
|
|
* flags.
|
|
* The limit '6' is determined by giving each probe
|
|
* stage (1448, 1188, 524) 2 chances to recover.
|
|
*/
|
|
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
|
|
(tp->t_rxtshift > 6)) {
|
|
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
|
|
tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
|
|
tp->t_maxseg = tp->t_pmtud_saved_maxseg;
|
|
V_tcp_pmtud_blackhole_failed++;
|
|
/*
|
|
* Reset the slow-start flight size as it
|
|
* may depend on the new MSS.
|
|
*/
|
|
if (CC_ALGO(tp)->conn_init != NULL)
|
|
CC_ALGO(tp)->conn_init(tp->ccv);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Disable RFC1323 and SACK if we haven't got any response to
|
|
* our third SYN to work-around some broken terminal servers
|
|
* (most of which have hopefully been retired) that have bad VJ
|
|
* header compression code which trashes TCP segments containing
|
|
* unknown-to-them TCP options.
|
|
*/
|
|
if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
|
|
(tp->t_rxtshift == 3))
|
|
tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
|
|
/*
|
|
* If we backed off this far, our srtt estimate is probably bogus.
|
|
* Clobber it so we'll take the next rtt measurement as our srtt;
|
|
* move the current srtt into rttvar to keep the current
|
|
* retransmit times until then.
|
|
*/
|
|
if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
|
|
#ifdef INET6
|
|
if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
|
|
in6_losing(tp->t_inpcb);
|
|
else
|
|
#endif
|
|
in_losing(tp->t_inpcb);
|
|
tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
|
|
tp->t_srtt = 0;
|
|
}
|
|
tp->snd_nxt = tp->snd_una;
|
|
tp->snd_recover = tp->snd_max;
|
|
/*
|
|
* Force a segment to be sent.
|
|
*/
|
|
tp->t_flags |= TF_ACKNOW;
|
|
/*
|
|
* If timing a segment in this window, stop the timer.
|
|
*/
|
|
tp->t_rtttime = 0;
|
|
|
|
cc_cong_signal(tp, NULL, CC_RTO);
|
|
|
|
(void) tp->t_fb->tfb_tcp_output(tp);
|
|
|
|
#ifdef TCPDEBUG
|
|
if (tp != NULL && (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
|
|
tcp_trace(TA_USER, ostate, tp, (void *)0, (struct tcphdr *)0,
|
|
PRU_SLOWTIMO);
|
|
#endif
|
|
TCP_PROBE2(debug__user, tp, PRU_SLOWTIMO);
|
|
INP_WUNLOCK(inp);
|
|
out:
|
|
CURVNET_RESTORE();
|
|
}
|
|
|
|
void
|
|
tcp_timer_activate(struct tcpcb *tp, uint32_t timer_type, u_int delta)
|
|
{
|
|
struct callout *t_callout;
|
|
timeout_t *f_callout;
|
|
struct inpcb *inp = tp->t_inpcb;
|
|
int cpu = inp_to_cpuid(inp);
|
|
|
|
#ifdef TCP_OFFLOAD
|
|
if (tp->t_flags & TF_TOE)
|
|
return;
|
|
#endif
|
|
|
|
if (tp->t_timers->tt_flags & TT_STOPPED)
|
|
return;
|
|
|
|
switch (timer_type) {
|
|
case TT_DELACK:
|
|
t_callout = &tp->t_timers->tt_delack;
|
|
f_callout = tcp_timer_delack;
|
|
break;
|
|
case TT_REXMT:
|
|
t_callout = &tp->t_timers->tt_rexmt;
|
|
f_callout = tcp_timer_rexmt;
|
|
break;
|
|
case TT_PERSIST:
|
|
t_callout = &tp->t_timers->tt_persist;
|
|
f_callout = tcp_timer_persist;
|
|
break;
|
|
case TT_KEEP:
|
|
t_callout = &tp->t_timers->tt_keep;
|
|
f_callout = tcp_timer_keep;
|
|
break;
|
|
case TT_2MSL:
|
|
t_callout = &tp->t_timers->tt_2msl;
|
|
f_callout = tcp_timer_2msl;
|
|
break;
|
|
default:
|
|
if (tp->t_fb->tfb_tcp_timer_activate) {
|
|
tp->t_fb->tfb_tcp_timer_activate(tp, timer_type, delta);
|
|
return;
|
|
}
|
|
panic("tp %p bad timer_type %#x", tp, timer_type);
|
|
}
|
|
if (delta == 0) {
|
|
callout_stop(t_callout);
|
|
} else {
|
|
callout_reset_on(t_callout, delta, f_callout, tp, cpu);
|
|
}
|
|
}
|
|
|
|
int
|
|
tcp_timer_active(struct tcpcb *tp, uint32_t timer_type)
|
|
{
|
|
struct callout *t_callout;
|
|
|
|
switch (timer_type) {
|
|
case TT_DELACK:
|
|
t_callout = &tp->t_timers->tt_delack;
|
|
break;
|
|
case TT_REXMT:
|
|
t_callout = &tp->t_timers->tt_rexmt;
|
|
break;
|
|
case TT_PERSIST:
|
|
t_callout = &tp->t_timers->tt_persist;
|
|
break;
|
|
case TT_KEEP:
|
|
t_callout = &tp->t_timers->tt_keep;
|
|
break;
|
|
case TT_2MSL:
|
|
t_callout = &tp->t_timers->tt_2msl;
|
|
break;
|
|
default:
|
|
if (tp->t_fb->tfb_tcp_timer_active) {
|
|
return(tp->t_fb->tfb_tcp_timer_active(tp, timer_type));
|
|
}
|
|
panic("tp %p bad timer_type %#x", tp, timer_type);
|
|
}
|
|
return callout_active(t_callout);
|
|
}
|
|
|
|
void
|
|
tcp_timer_stop(struct tcpcb *tp, uint32_t timer_type)
|
|
{
|
|
struct callout *t_callout;
|
|
|
|
tp->t_timers->tt_flags |= TT_STOPPED;
|
|
switch (timer_type) {
|
|
case TT_DELACK:
|
|
t_callout = &tp->t_timers->tt_delack;
|
|
break;
|
|
case TT_REXMT:
|
|
t_callout = &tp->t_timers->tt_rexmt;
|
|
break;
|
|
case TT_PERSIST:
|
|
t_callout = &tp->t_timers->tt_persist;
|
|
break;
|
|
case TT_KEEP:
|
|
t_callout = &tp->t_timers->tt_keep;
|
|
break;
|
|
case TT_2MSL:
|
|
t_callout = &tp->t_timers->tt_2msl;
|
|
break;
|
|
default:
|
|
if (tp->t_fb->tfb_tcp_timer_stop) {
|
|
/*
|
|
* XXXrrs we need to look at this with the
|
|
* stop case below (flags).
|
|
*/
|
|
tp->t_fb->tfb_tcp_timer_stop(tp, timer_type);
|
|
return;
|
|
}
|
|
panic("tp %p bad timer_type %#x", tp, timer_type);
|
|
}
|
|
|
|
if (callout_async_drain(t_callout, tcp_timer_discard) == 0) {
|
|
/*
|
|
* Can't stop the callout, defer tcpcb actual deletion
|
|
* to the last one. We do this using the async drain
|
|
* function and incrementing the count in
|
|
*/
|
|
tp->t_timers->tt_draincnt++;
|
|
}
|
|
}
|
|
|
|
#define ticks_to_msecs(t) (1000*(t) / hz)
|
|
|
|
void
|
|
tcp_timer_to_xtimer(struct tcpcb *tp, struct tcp_timer *timer,
|
|
struct xtcp_timer *xtimer)
|
|
{
|
|
sbintime_t now;
|
|
|
|
bzero(xtimer, sizeof(*xtimer));
|
|
if (timer == NULL)
|
|
return;
|
|
now = getsbinuptime();
|
|
if (callout_active(&timer->tt_delack))
|
|
xtimer->tt_delack = (timer->tt_delack.c_time - now) / SBT_1MS;
|
|
if (callout_active(&timer->tt_rexmt))
|
|
xtimer->tt_rexmt = (timer->tt_rexmt.c_time - now) / SBT_1MS;
|
|
if (callout_active(&timer->tt_persist))
|
|
xtimer->tt_persist = (timer->tt_persist.c_time - now) / SBT_1MS;
|
|
if (callout_active(&timer->tt_keep))
|
|
xtimer->tt_keep = (timer->tt_keep.c_time - now) / SBT_1MS;
|
|
if (callout_active(&timer->tt_2msl))
|
|
xtimer->tt_2msl = (timer->tt_2msl.c_time - now) / SBT_1MS;
|
|
xtimer->t_rcvtime = ticks_to_msecs(ticks - tp->t_rcvtime);
|
|
}
|