1710 lines
46 KiB
C
1710 lines
46 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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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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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_subr.c 8.2 (Berkeley) 5/24/95
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* $FreeBSD$
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*/
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#include "opt_compat.h"
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#include "opt_inet6.h"
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#include "opt_ipsec.h"
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#include "opt_mac.h"
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#include "opt_tcpdebug.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/callout.h>
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#include <sys/kernel.h>
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#include <sys/sysctl.h>
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#include <sys/mac.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#ifdef INET6
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#include <sys/domain.h>
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#endif
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#include <sys/proc.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/protosw.h>
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#include <sys/random.h>
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#include <vm/uma.h>
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#include <net/route.h>
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#include <net/if.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#ifdef INET6
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#include <netinet/ip6.h>
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#endif
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#include <netinet/in_pcb.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/in_var.h>
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#include <netinet/ip_var.h>
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#ifdef INET6
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#include <netinet6/ip6_var.h>
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#endif
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#include <netinet/tcp.h>
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#include <netinet/tcp_fsm.h>
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#include <netinet/tcp_seq.h>
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#include <netinet/tcp_timer.h>
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#include <netinet/tcp_var.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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#include <netinet6/ip6protosw.h>
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#ifdef IPSEC
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#include <netinet6/ipsec.h>
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#ifdef INET6
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#include <netinet6/ipsec6.h>
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#endif
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#endif /*IPSEC*/
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#ifdef FAST_IPSEC
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#include <netipsec/ipsec.h>
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#ifdef INET6
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#include <netipsec/ipsec6.h>
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#endif
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#define IPSEC
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#endif /*FAST_IPSEC*/
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#include <machine/in_cksum.h>
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#include <sys/md5.h>
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int tcp_mssdflt = TCP_MSS;
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SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW,
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&tcp_mssdflt , 0, "Default TCP Maximum Segment Size");
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#ifdef INET6
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int tcp_v6mssdflt = TCP6_MSS;
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SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
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CTLFLAG_RW, &tcp_v6mssdflt , 0,
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"Default TCP Maximum Segment Size for IPv6");
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#endif
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#if 0
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static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
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SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW,
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&tcp_rttdflt , 0, "Default maximum TCP Round Trip Time");
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#endif
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int tcp_do_rfc1323 = 1;
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SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
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&tcp_do_rfc1323 , 0, "Enable rfc1323 (high performance TCP) extensions");
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int tcp_do_rfc1644 = 0;
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SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1644, rfc1644, CTLFLAG_RW,
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&tcp_do_rfc1644 , 0, "Enable rfc1644 (TTCP) extensions");
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static int tcp_tcbhashsize = 0;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD,
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&tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
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static int do_tcpdrain = 1;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
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"Enable tcp_drain routine for extra help when low on mbufs");
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD,
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&tcbinfo.ipi_count, 0, "Number of active PCBs");
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static int icmp_may_rst = 1;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0,
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"Certain ICMP unreachable messages may abort connections in SYN_SENT");
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static int tcp_isn_reseed_interval = 0;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
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&tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret");
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/*
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* TCP bandwidth limiting sysctls. Note that the default lower bound of
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* 1024 exists only for debugging. A good production default would be
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* something like 6100.
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*/
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static int tcp_inflight_enable = 0;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW,
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&tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting");
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static int tcp_inflight_debug = 0;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW,
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&tcp_inflight_debug, 0, "Debug TCP inflight calculations");
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static int tcp_inflight_min = 6144;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW,
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&tcp_inflight_min, 0, "Lower-bound for TCP inflight window");
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static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW,
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&tcp_inflight_max, 0, "Upper-bound for TCP inflight window");
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static int tcp_inflight_stab = 20;
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SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW,
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&tcp_inflight_stab, 0, "Inflight Algorithm Stabilization 20 = 2 packets");
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static void tcp_cleartaocache(void);
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static struct inpcb *tcp_notify(struct inpcb *, int);
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/*
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* Target size of TCP PCB hash tables. Must be a power of two.
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*
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* Note that this can be overridden by the kernel environment
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* variable net.inet.tcp.tcbhashsize
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*/
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#ifndef TCBHASHSIZE
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#define TCBHASHSIZE 512
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#endif
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/*
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* This is the actual shape of what we allocate using the zone
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* allocator. Doing it this way allows us to protect both structures
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* using the same generation count, and also eliminates the overhead
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* of allocating tcpcbs separately. By hiding the structure here,
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* we avoid changing most of the rest of the code (although it needs
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* to be changed, eventually, for greater efficiency).
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*/
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#define ALIGNMENT 32
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#define ALIGNM1 (ALIGNMENT - 1)
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struct inp_tp {
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union {
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struct inpcb inp;
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char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1];
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} inp_tp_u;
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struct tcpcb tcb;
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struct callout inp_tp_rexmt, inp_tp_persist, inp_tp_keep, inp_tp_2msl;
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struct callout inp_tp_delack;
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};
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#undef ALIGNMENT
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#undef ALIGNM1
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/*
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* Tcp initialization
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*/
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void
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tcp_init()
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{
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int hashsize = TCBHASHSIZE;
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tcp_ccgen = 1;
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tcp_cleartaocache();
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tcp_delacktime = TCPTV_DELACK;
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tcp_keepinit = TCPTV_KEEP_INIT;
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tcp_keepidle = TCPTV_KEEP_IDLE;
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tcp_keepintvl = TCPTV_KEEPINTVL;
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tcp_maxpersistidle = TCPTV_KEEP_IDLE;
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tcp_msl = TCPTV_MSL;
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tcp_rexmit_min = TCPTV_MIN;
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tcp_rexmit_slop = TCPTV_CPU_VAR;
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INP_INFO_LOCK_INIT(&tcbinfo, "tcp");
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LIST_INIT(&tcb);
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tcbinfo.listhead = &tcb;
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TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
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if (!powerof2(hashsize)) {
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printf("WARNING: TCB hash size not a power of 2\n");
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hashsize = 512; /* safe default */
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}
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tcp_tcbhashsize = hashsize;
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tcbinfo.hashbase = hashinit(hashsize, M_PCB, &tcbinfo.hashmask);
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tcbinfo.porthashbase = hashinit(hashsize, M_PCB,
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&tcbinfo.porthashmask);
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tcbinfo.ipi_zone = uma_zcreate("tcpcb", sizeof(struct inp_tp),
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NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
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uma_zone_set_max(tcbinfo.ipi_zone, maxsockets);
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#ifdef INET6
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#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
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#else /* INET6 */
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#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
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#endif /* INET6 */
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if (max_protohdr < TCP_MINPROTOHDR)
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max_protohdr = TCP_MINPROTOHDR;
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if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
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panic("tcp_init");
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#undef TCP_MINPROTOHDR
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syncache_init();
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}
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/*
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* Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
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* tcp_template used to store this data in mbufs, but we now recopy it out
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* of the tcpcb each time to conserve mbufs.
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*/
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void
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tcp_fillheaders(tp, ip_ptr, tcp_ptr)
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struct tcpcb *tp;
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void *ip_ptr;
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void *tcp_ptr;
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{
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struct inpcb *inp = tp->t_inpcb;
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struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr;
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#ifdef INET6
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if ((inp->inp_vflag & INP_IPV6) != 0) {
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struct ip6_hdr *ip6;
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ip6 = (struct ip6_hdr *)ip_ptr;
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ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
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(inp->in6p_flowinfo & IPV6_FLOWINFO_MASK);
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ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
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(IPV6_VERSION & IPV6_VERSION_MASK);
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ip6->ip6_nxt = IPPROTO_TCP;
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ip6->ip6_plen = sizeof(struct tcphdr);
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ip6->ip6_src = inp->in6p_laddr;
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ip6->ip6_dst = inp->in6p_faddr;
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tcp_hdr->th_sum = 0;
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} else
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#endif
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{
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struct ip *ip = (struct ip *) ip_ptr;
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ip->ip_v = IPVERSION;
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ip->ip_hl = 5;
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ip->ip_tos = 0;
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ip->ip_len = 0;
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ip->ip_id = 0;
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ip->ip_off = 0;
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ip->ip_ttl = 0;
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ip->ip_sum = 0;
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ip->ip_p = IPPROTO_TCP;
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ip->ip_src = inp->inp_laddr;
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ip->ip_dst = inp->inp_faddr;
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tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
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htons(sizeof(struct tcphdr) + IPPROTO_TCP));
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}
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tcp_hdr->th_sport = inp->inp_lport;
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tcp_hdr->th_dport = inp->inp_fport;
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tcp_hdr->th_seq = 0;
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tcp_hdr->th_ack = 0;
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tcp_hdr->th_x2 = 0;
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tcp_hdr->th_off = 5;
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tcp_hdr->th_flags = 0;
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tcp_hdr->th_win = 0;
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tcp_hdr->th_urp = 0;
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}
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/*
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* Create template to be used to send tcp packets on a connection.
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* Allocates an mbuf and fills in a skeletal tcp/ip header. The only
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* use for this function is in keepalives, which use tcp_respond.
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*/
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struct tcptemp *
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tcp_maketemplate(tp)
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struct tcpcb *tp;
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{
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struct mbuf *m;
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struct tcptemp *n;
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m = m_get(M_NOWAIT, MT_HEADER);
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if (m == NULL)
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return (0);
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m->m_len = sizeof(struct tcptemp);
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n = mtod(m, struct tcptemp *);
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tcp_fillheaders(tp, (void *)&n->tt_ipgen, (void *)&n->tt_t);
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return (n);
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}
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/*
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* Send a single message to the TCP at address specified by
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* the given TCP/IP header. If m == 0, then we make a copy
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* of the tcpiphdr at ti and send directly to the addressed host.
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* This is used to force keep alive messages out using the TCP
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* template for a connection. If flags are given then we send
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* a message back to the TCP which originated the * segment ti,
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* and discard the mbuf containing it and any other attached mbufs.
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*
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* In any case the ack and sequence number of the transmitted
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* segment are as specified by the parameters.
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*
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* NOTE: If m != NULL, then ti must point to *inside* the mbuf.
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*/
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void
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tcp_respond(tp, ipgen, th, m, ack, seq, flags)
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struct tcpcb *tp;
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void *ipgen;
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register struct tcphdr *th;
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register struct mbuf *m;
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tcp_seq ack, seq;
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int flags;
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{
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register int tlen;
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int win = 0;
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struct route *ro = 0;
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struct route sro;
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struct ip *ip;
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struct tcphdr *nth;
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#ifdef INET6
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struct route_in6 *ro6 = 0;
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struct route_in6 sro6;
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struct ip6_hdr *ip6;
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int isipv6;
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#endif /* INET6 */
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int ipflags = 0;
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KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
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#ifdef INET6
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isipv6 = ((struct ip *)ipgen)->ip_v == 6;
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ip6 = ipgen;
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#endif /* INET6 */
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ip = ipgen;
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if (tp) {
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if (!(flags & TH_RST)) {
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win = sbspace(&tp->t_inpcb->inp_socket->so_rcv);
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if (win > (long)TCP_MAXWIN << tp->rcv_scale)
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win = (long)TCP_MAXWIN << tp->rcv_scale;
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}
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#ifdef INET6
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if (isipv6)
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ro6 = &tp->t_inpcb->in6p_route;
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else
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#endif /* INET6 */
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ro = &tp->t_inpcb->inp_route;
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} else {
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#ifdef INET6
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if (isipv6) {
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ro6 = &sro6;
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bzero(ro6, sizeof *ro6);
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} else
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#endif /* INET6 */
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{
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ro = &sro;
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bzero(ro, sizeof *ro);
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}
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}
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if (m == 0) {
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m = m_gethdr(M_NOWAIT, MT_HEADER);
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if (m == NULL)
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return;
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tlen = 0;
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m->m_data += max_linkhdr;
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#ifdef INET6
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if (isipv6) {
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bcopy((caddr_t)ip6, mtod(m, caddr_t),
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sizeof(struct ip6_hdr));
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ip6 = mtod(m, struct ip6_hdr *);
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nth = (struct tcphdr *)(ip6 + 1);
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} else
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#endif /* INET6 */
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{
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bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
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ip = mtod(m, struct ip *);
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nth = (struct tcphdr *)(ip + 1);
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}
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bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
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flags = TH_ACK;
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} else {
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m_freem(m->m_next);
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m->m_next = 0;
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m->m_data = (caddr_t)ipgen;
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/* m_len is set later */
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tlen = 0;
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#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
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#ifdef INET6
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if (isipv6) {
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xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
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nth = (struct tcphdr *)(ip6 + 1);
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} else
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#endif /* INET6 */
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{
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xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long);
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nth = (struct tcphdr *)(ip + 1);
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}
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if (th != nth) {
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/*
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* this is usually a case when an extension header
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* exists between the IPv6 header and the
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* TCP header.
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*/
|
|
nth->th_sport = th->th_sport;
|
|
nth->th_dport = th->th_dport;
|
|
}
|
|
xchg(nth->th_dport, nth->th_sport, n_short);
|
|
#undef xchg
|
|
}
|
|
#ifdef INET6
|
|
if (isipv6) {
|
|
ip6->ip6_flow = 0;
|
|
ip6->ip6_vfc = IPV6_VERSION;
|
|
ip6->ip6_nxt = IPPROTO_TCP;
|
|
ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) +
|
|
tlen));
|
|
tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
|
|
} else
|
|
#endif
|
|
{
|
|
tlen += sizeof (struct tcpiphdr);
|
|
ip->ip_len = tlen;
|
|
ip->ip_ttl = ip_defttl;
|
|
}
|
|
m->m_len = tlen;
|
|
m->m_pkthdr.len = tlen;
|
|
m->m_pkthdr.rcvif = (struct ifnet *) 0;
|
|
#ifdef MAC
|
|
if (tp != NULL) {
|
|
/*
|
|
* Packet is associated with a socket, so allow the
|
|
* label of the response to reflect the socket label.
|
|
*/
|
|
mac_create_mbuf_from_socket(tp->t_inpcb->inp_socket, m);
|
|
} else {
|
|
/*
|
|
* XXXMAC: This will need to call a mac function that
|
|
* modifies the mbuf label in place for TCP datagrams
|
|
* not associated with a PCB.
|
|
*/
|
|
}
|
|
#endif
|
|
nth->th_seq = htonl(seq);
|
|
nth->th_ack = htonl(ack);
|
|
nth->th_x2 = 0;
|
|
nth->th_off = sizeof (struct tcphdr) >> 2;
|
|
nth->th_flags = flags;
|
|
if (tp)
|
|
nth->th_win = htons((u_short) (win >> tp->rcv_scale));
|
|
else
|
|
nth->th_win = htons((u_short)win);
|
|
nth->th_urp = 0;
|
|
#ifdef INET6
|
|
if (isipv6) {
|
|
nth->th_sum = 0;
|
|
nth->th_sum = in6_cksum(m, IPPROTO_TCP,
|
|
sizeof(struct ip6_hdr),
|
|
tlen - sizeof(struct ip6_hdr));
|
|
ip6->ip6_hlim = in6_selecthlim(tp ? tp->t_inpcb : NULL,
|
|
ro6 && ro6->ro_rt ?
|
|
ro6->ro_rt->rt_ifp :
|
|
NULL);
|
|
} else
|
|
#endif /* INET6 */
|
|
{
|
|
nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
|
|
htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
|
|
m->m_pkthdr.csum_flags = CSUM_TCP;
|
|
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
|
|
}
|
|
#ifdef TCPDEBUG
|
|
if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG))
|
|
tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
|
|
#endif
|
|
#ifdef INET6
|
|
if (isipv6) {
|
|
(void)ip6_output(m, NULL, ro6, ipflags, NULL, NULL,
|
|
tp ? tp->t_inpcb : NULL);
|
|
if (ro6 == &sro6 && ro6->ro_rt) {
|
|
RTFREE(ro6->ro_rt);
|
|
ro6->ro_rt = NULL;
|
|
}
|
|
} else
|
|
#endif /* INET6 */
|
|
{
|
|
(void) ip_output(m, NULL, ro, ipflags, NULL, tp ? tp->t_inpcb : NULL);
|
|
if (ro == &sro && ro->ro_rt) {
|
|
RTFREE(ro->ro_rt);
|
|
ro->ro_rt = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Create a new TCP control block, making an
|
|
* empty reassembly queue and hooking it to the argument
|
|
* protocol control block. The `inp' parameter must have
|
|
* come from the zone allocator set up in tcp_init().
|
|
*/
|
|
struct tcpcb *
|
|
tcp_newtcpcb(inp)
|
|
struct inpcb *inp;
|
|
{
|
|
struct inp_tp *it;
|
|
register struct tcpcb *tp;
|
|
#ifdef INET6
|
|
int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
|
|
#endif /* INET6 */
|
|
|
|
it = (struct inp_tp *)inp;
|
|
tp = &it->tcb;
|
|
bzero((char *) tp, sizeof(struct tcpcb));
|
|
LIST_INIT(&tp->t_segq);
|
|
tp->t_maxseg = tp->t_maxopd =
|
|
#ifdef INET6
|
|
isipv6 ? tcp_v6mssdflt :
|
|
#endif /* INET6 */
|
|
tcp_mssdflt;
|
|
|
|
/* Set up our timeouts. */
|
|
callout_init(tp->tt_rexmt = &it->inp_tp_rexmt, 0);
|
|
callout_init(tp->tt_persist = &it->inp_tp_persist, 0);
|
|
callout_init(tp->tt_keep = &it->inp_tp_keep, 0);
|
|
callout_init(tp->tt_2msl = &it->inp_tp_2msl, 0);
|
|
callout_init(tp->tt_delack = &it->inp_tp_delack, 0);
|
|
|
|
if (tcp_do_rfc1323)
|
|
tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
|
|
if (tcp_do_rfc1644)
|
|
tp->t_flags |= TF_REQ_CC;
|
|
tp->t_inpcb = inp; /* XXX */
|
|
/*
|
|
* Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
|
|
* rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
|
|
* reasonable initial retransmit time.
|
|
*/
|
|
tp->t_srtt = TCPTV_SRTTBASE;
|
|
tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
|
|
tp->t_rttmin = tcp_rexmit_min;
|
|
tp->t_rxtcur = TCPTV_RTOBASE;
|
|
tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
|
|
tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
|
|
tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
|
|
tp->t_rcvtime = ticks;
|
|
tp->t_bw_rtttime = ticks;
|
|
/*
|
|
* IPv4 TTL initialization is necessary for an IPv6 socket as well,
|
|
* because the socket may be bound to an IPv6 wildcard address,
|
|
* which may match an IPv4-mapped IPv6 address.
|
|
*/
|
|
inp->inp_ip_ttl = ip_defttl;
|
|
inp->inp_ppcb = (caddr_t)tp;
|
|
return (tp); /* XXX */
|
|
}
|
|
|
|
/*
|
|
* Drop a TCP connection, reporting
|
|
* the specified error. If connection is synchronized,
|
|
* then send a RST to peer.
|
|
*/
|
|
struct tcpcb *
|
|
tcp_drop(tp, errno)
|
|
register struct tcpcb *tp;
|
|
int errno;
|
|
{
|
|
struct socket *so = tp->t_inpcb->inp_socket;
|
|
|
|
if (TCPS_HAVERCVDSYN(tp->t_state)) {
|
|
tp->t_state = TCPS_CLOSED;
|
|
(void) tcp_output(tp);
|
|
tcpstat.tcps_drops++;
|
|
} else
|
|
tcpstat.tcps_conndrops++;
|
|
if (errno == ETIMEDOUT && tp->t_softerror)
|
|
errno = tp->t_softerror;
|
|
so->so_error = errno;
|
|
return (tcp_close(tp));
|
|
}
|
|
|
|
/*
|
|
* Close a TCP control block:
|
|
* discard all space held by the tcp
|
|
* discard internet protocol block
|
|
* wake up any sleepers
|
|
*/
|
|
struct tcpcb *
|
|
tcp_close(tp)
|
|
register struct tcpcb *tp;
|
|
{
|
|
register struct tseg_qent *q;
|
|
struct inpcb *inp = tp->t_inpcb;
|
|
struct socket *so = inp->inp_socket;
|
|
#ifdef INET6
|
|
int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
|
|
#endif /* INET6 */
|
|
register struct rtentry *rt;
|
|
int dosavessthresh;
|
|
|
|
/*
|
|
* Make sure that all of our timers are stopped before we
|
|
* delete the PCB.
|
|
*/
|
|
callout_stop(tp->tt_rexmt);
|
|
callout_stop(tp->tt_persist);
|
|
callout_stop(tp->tt_keep);
|
|
callout_stop(tp->tt_2msl);
|
|
callout_stop(tp->tt_delack);
|
|
|
|
/*
|
|
* If we got enough samples through the srtt filter,
|
|
* save the rtt and rttvar in the routing entry.
|
|
* 'Enough' is arbitrarily defined as the 16 samples.
|
|
* 16 samples is enough for the srtt filter to converge
|
|
* to within 5% of the correct value; fewer samples and
|
|
* we could save a very bogus rtt.
|
|
*
|
|
* Don't update the default route's characteristics and don't
|
|
* update anything that the user "locked".
|
|
*/
|
|
if (tp->t_rttupdated >= 16) {
|
|
register u_long i = 0;
|
|
#ifdef INET6
|
|
if (isipv6) {
|
|
struct sockaddr_in6 *sin6;
|
|
|
|
if ((rt = inp->in6p_route.ro_rt) == NULL)
|
|
goto no_valid_rt;
|
|
sin6 = (struct sockaddr_in6 *)rt_key(rt);
|
|
if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
|
|
goto no_valid_rt;
|
|
}
|
|
else
|
|
#endif /* INET6 */
|
|
if ((rt = inp->inp_route.ro_rt) == NULL ||
|
|
((struct sockaddr_in *)rt_key(rt))->sin_addr.s_addr
|
|
== INADDR_ANY)
|
|
goto no_valid_rt;
|
|
|
|
if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) {
|
|
i = tp->t_srtt *
|
|
(RTM_RTTUNIT / (hz * TCP_RTT_SCALE));
|
|
if (rt->rt_rmx.rmx_rtt && i)
|
|
/*
|
|
* filter this update to half the old & half
|
|
* the new values, converting scale.
|
|
* See route.h and tcp_var.h for a
|
|
* description of the scaling constants.
|
|
*/
|
|
rt->rt_rmx.rmx_rtt =
|
|
(rt->rt_rmx.rmx_rtt + i) / 2;
|
|
else
|
|
rt->rt_rmx.rmx_rtt = i;
|
|
tcpstat.tcps_cachedrtt++;
|
|
}
|
|
if ((rt->rt_rmx.rmx_locks & RTV_RTTVAR) == 0) {
|
|
i = tp->t_rttvar *
|
|
(RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE));
|
|
if (rt->rt_rmx.rmx_rttvar && i)
|
|
rt->rt_rmx.rmx_rttvar =
|
|
(rt->rt_rmx.rmx_rttvar + i) / 2;
|
|
else
|
|
rt->rt_rmx.rmx_rttvar = i;
|
|
tcpstat.tcps_cachedrttvar++;
|
|
}
|
|
/*
|
|
* The old comment here said:
|
|
* update the pipelimit (ssthresh) if it has been updated
|
|
* already or if a pipesize was specified & the threshhold
|
|
* got below half the pipesize. I.e., wait for bad news
|
|
* before we start updating, then update on both good
|
|
* and bad news.
|
|
*
|
|
* But we want to save the ssthresh even if no pipesize is
|
|
* specified explicitly in the route, because such
|
|
* connections still have an implicit pipesize specified
|
|
* by the global tcp_sendspace. In the absence of a reliable
|
|
* way to calculate the pipesize, it will have to do.
|
|
*/
|
|
i = tp->snd_ssthresh;
|
|
if (rt->rt_rmx.rmx_sendpipe != 0)
|
|
dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe / 2);
|
|
else
|
|
dosavessthresh = (i < so->so_snd.sb_hiwat / 2);
|
|
if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 &&
|
|
i != 0 && rt->rt_rmx.rmx_ssthresh != 0)
|
|
|| dosavessthresh) {
|
|
/*
|
|
* convert the limit from user data bytes to
|
|
* packets then to packet data bytes.
|
|
*/
|
|
i = (i + tp->t_maxseg / 2) / tp->t_maxseg;
|
|
if (i < 2)
|
|
i = 2;
|
|
i *= (u_long)(tp->t_maxseg +
|
|
#ifdef INET6
|
|
(isipv6 ? sizeof (struct ip6_hdr) +
|
|
sizeof (struct tcphdr) :
|
|
#endif
|
|
sizeof (struct tcpiphdr)
|
|
#ifdef INET6
|
|
)
|
|
#endif
|
|
);
|
|
if (rt->rt_rmx.rmx_ssthresh)
|
|
rt->rt_rmx.rmx_ssthresh =
|
|
(rt->rt_rmx.rmx_ssthresh + i) / 2;
|
|
else
|
|
rt->rt_rmx.rmx_ssthresh = i;
|
|
tcpstat.tcps_cachedssthresh++;
|
|
}
|
|
}
|
|
no_valid_rt:
|
|
/* free the reassembly queue, if any */
|
|
while((q = LIST_FIRST(&tp->t_segq)) != NULL) {
|
|
LIST_REMOVE(q, tqe_q);
|
|
m_freem(q->tqe_m);
|
|
FREE(q, M_TSEGQ);
|
|
}
|
|
inp->inp_ppcb = NULL;
|
|
tp->t_inpcb = NULL;
|
|
soisdisconnected(so);
|
|
#ifdef INET6
|
|
if (INP_CHECK_SOCKAF(so, AF_INET6))
|
|
in6_pcbdetach(inp);
|
|
else
|
|
#endif /* INET6 */
|
|
in_pcbdetach(inp);
|
|
tcpstat.tcps_closed++;
|
|
return ((struct tcpcb *)0);
|
|
}
|
|
|
|
void
|
|
tcp_drain()
|
|
{
|
|
if (do_tcpdrain)
|
|
{
|
|
struct inpcb *inpb;
|
|
struct tcpcb *tcpb;
|
|
struct tseg_qent *te;
|
|
|
|
/*
|
|
* Walk the tcpbs, if existing, and flush the reassembly queue,
|
|
* if there is one...
|
|
* XXX: The "Net/3" implementation doesn't imply that the TCP
|
|
* reassembly queue should be flushed, but in a situation
|
|
* where we're really low on mbufs, this is potentially
|
|
* usefull.
|
|
*/
|
|
INP_INFO_RLOCK(&tcbinfo);
|
|
LIST_FOREACH(inpb, tcbinfo.listhead, inp_list) {
|
|
INP_LOCK(inpb);
|
|
if ((tcpb = intotcpcb(inpb))) {
|
|
while ((te = LIST_FIRST(&tcpb->t_segq))
|
|
!= NULL) {
|
|
LIST_REMOVE(te, tqe_q);
|
|
m_freem(te->tqe_m);
|
|
FREE(te, M_TSEGQ);
|
|
}
|
|
}
|
|
INP_UNLOCK(inpb);
|
|
}
|
|
INP_INFO_RUNLOCK(&tcbinfo);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Notify a tcp user of an asynchronous error;
|
|
* store error as soft error, but wake up user
|
|
* (for now, won't do anything until can select for soft error).
|
|
*
|
|
* Do not wake up user since there currently is no mechanism for
|
|
* reporting soft errors (yet - a kqueue filter may be added).
|
|
*/
|
|
static struct inpcb *
|
|
tcp_notify(inp, error)
|
|
struct inpcb *inp;
|
|
int error;
|
|
{
|
|
struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb;
|
|
|
|
/*
|
|
* Ignore some errors if we are hooked up.
|
|
* If connection hasn't completed, has retransmitted several times,
|
|
* and receives a second error, give up now. This is better
|
|
* than waiting a long time to establish a connection that
|
|
* can never complete.
|
|
*/
|
|
if (tp->t_state == TCPS_ESTABLISHED &&
|
|
(error == EHOSTUNREACH || error == ENETUNREACH ||
|
|
error == EHOSTDOWN)) {
|
|
return inp;
|
|
} else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
|
|
tp->t_softerror) {
|
|
tcp_drop(tp, error);
|
|
return (struct inpcb *)0;
|
|
} else {
|
|
tp->t_softerror = error;
|
|
return inp;
|
|
}
|
|
#if 0
|
|
wakeup((caddr_t) &so->so_timeo);
|
|
sorwakeup(so);
|
|
sowwakeup(so);
|
|
#endif
|
|
}
|
|
|
|
static int
|
|
tcp_pcblist(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int error, i, n, s;
|
|
struct inpcb *inp, **inp_list;
|
|
inp_gen_t gencnt;
|
|
struct xinpgen xig;
|
|
|
|
/*
|
|
* The process of preparing the TCB list is too time-consuming and
|
|
* resource-intensive to repeat twice on every request.
|
|
*/
|
|
if (req->oldptr == 0) {
|
|
n = tcbinfo.ipi_count;
|
|
req->oldidx = 2 * (sizeof xig)
|
|
+ (n + n/8) * sizeof(struct xtcpcb);
|
|
return 0;
|
|
}
|
|
|
|
if (req->newptr != 0)
|
|
return EPERM;
|
|
|
|
/*
|
|
* OK, now we're committed to doing something.
|
|
*/
|
|
s = splnet();
|
|
INP_INFO_RLOCK(&tcbinfo);
|
|
gencnt = tcbinfo.ipi_gencnt;
|
|
n = tcbinfo.ipi_count;
|
|
INP_INFO_RUNLOCK(&tcbinfo);
|
|
splx(s);
|
|
|
|
sysctl_wire_old_buffer(req, 2 * (sizeof xig)
|
|
+ n * sizeof(struct xtcpcb));
|
|
|
|
xig.xig_len = sizeof xig;
|
|
xig.xig_count = n;
|
|
xig.xig_gen = gencnt;
|
|
xig.xig_sogen = so_gencnt;
|
|
error = SYSCTL_OUT(req, &xig, sizeof xig);
|
|
if (error)
|
|
return error;
|
|
|
|
inp_list = malloc(n * sizeof *inp_list, M_TEMP, 0);
|
|
if (inp_list == 0)
|
|
return ENOMEM;
|
|
|
|
s = splnet();
|
|
INP_INFO_RLOCK(&tcbinfo);
|
|
for (inp = LIST_FIRST(tcbinfo.listhead), i = 0; inp && i < n;
|
|
inp = LIST_NEXT(inp, inp_list)) {
|
|
INP_LOCK(inp);
|
|
if (inp->inp_gencnt <= gencnt &&
|
|
cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0)
|
|
inp_list[i++] = inp;
|
|
INP_UNLOCK(inp);
|
|
}
|
|
INP_INFO_RUNLOCK(&tcbinfo);
|
|
splx(s);
|
|
n = i;
|
|
|
|
error = 0;
|
|
for (i = 0; i < n; i++) {
|
|
inp = inp_list[i];
|
|
INP_LOCK(inp);
|
|
if (inp->inp_gencnt <= gencnt) {
|
|
struct xtcpcb xt;
|
|
caddr_t inp_ppcb;
|
|
xt.xt_len = sizeof xt;
|
|
/* XXX should avoid extra copy */
|
|
bcopy(inp, &xt.xt_inp, sizeof *inp);
|
|
inp_ppcb = inp->inp_ppcb;
|
|
if (inp_ppcb != NULL)
|
|
bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
|
|
else
|
|
bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
|
|
if (inp->inp_socket)
|
|
sotoxsocket(inp->inp_socket, &xt.xt_socket);
|
|
error = SYSCTL_OUT(req, &xt, sizeof xt);
|
|
}
|
|
INP_UNLOCK(inp);
|
|
}
|
|
if (!error) {
|
|
/*
|
|
* Give the user an updated idea of our state.
|
|
* If the generation differs from what we told
|
|
* her before, she knows that something happened
|
|
* while we were processing this request, and it
|
|
* might be necessary to retry.
|
|
*/
|
|
s = splnet();
|
|
INP_INFO_RLOCK(&tcbinfo);
|
|
xig.xig_gen = tcbinfo.ipi_gencnt;
|
|
xig.xig_sogen = so_gencnt;
|
|
xig.xig_count = tcbinfo.ipi_count;
|
|
INP_INFO_RUNLOCK(&tcbinfo);
|
|
splx(s);
|
|
error = SYSCTL_OUT(req, &xig, sizeof xig);
|
|
}
|
|
free(inp_list, M_TEMP);
|
|
return error;
|
|
}
|
|
|
|
SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
|
|
tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
|
|
|
|
static int
|
|
tcp_getcred(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
struct xucred xuc;
|
|
struct sockaddr_in addrs[2];
|
|
struct inpcb *inp;
|
|
int error, s;
|
|
|
|
error = suser_cred(req->td->td_ucred, PRISON_ROOT);
|
|
if (error)
|
|
return (error);
|
|
error = SYSCTL_IN(req, addrs, sizeof(addrs));
|
|
if (error)
|
|
return (error);
|
|
s = splnet();
|
|
INP_INFO_RLOCK(&tcbinfo);
|
|
inp = in_pcblookup_hash(&tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
|
|
addrs[0].sin_addr, addrs[0].sin_port, 0, NULL);
|
|
if (inp == NULL) {
|
|
error = ENOENT;
|
|
goto outunlocked;
|
|
}
|
|
INP_LOCK(inp);
|
|
if (inp->inp_socket == NULL) {
|
|
error = ENOENT;
|
|
goto out;
|
|
}
|
|
error = cr_canseesocket(req->td->td_ucred, inp->inp_socket);
|
|
if (error)
|
|
goto out;
|
|
cru2x(inp->inp_socket->so_cred, &xuc);
|
|
out:
|
|
INP_UNLOCK(inp);
|
|
outunlocked:
|
|
INP_INFO_RUNLOCK(&tcbinfo);
|
|
splx(s);
|
|
if (error == 0)
|
|
error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
|
|
return (error);
|
|
}
|
|
|
|
SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
|
|
CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
|
|
tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
|
|
|
|
#ifdef INET6
|
|
static int
|
|
tcp6_getcred(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
struct xucred xuc;
|
|
struct sockaddr_in6 addrs[2];
|
|
struct inpcb *inp;
|
|
int error, s, mapped = 0;
|
|
|
|
error = suser_cred(req->td->td_ucred, PRISON_ROOT);
|
|
if (error)
|
|
return (error);
|
|
error = SYSCTL_IN(req, addrs, sizeof(addrs));
|
|
if (error)
|
|
return (error);
|
|
if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
|
|
if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
|
|
mapped = 1;
|
|
else
|
|
return (EINVAL);
|
|
}
|
|
s = splnet();
|
|
INP_INFO_RLOCK(&tcbinfo);
|
|
if (mapped == 1)
|
|
inp = in_pcblookup_hash(&tcbinfo,
|
|
*(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
|
|
addrs[1].sin6_port,
|
|
*(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
|
|
addrs[0].sin6_port,
|
|
0, NULL);
|
|
else
|
|
inp = in6_pcblookup_hash(&tcbinfo, &addrs[1].sin6_addr,
|
|
addrs[1].sin6_port,
|
|
&addrs[0].sin6_addr, addrs[0].sin6_port,
|
|
0, NULL);
|
|
if (inp == NULL) {
|
|
error = ENOENT;
|
|
goto outunlocked;
|
|
}
|
|
INP_LOCK(inp);
|
|
if (inp->inp_socket == NULL) {
|
|
error = ENOENT;
|
|
goto out;
|
|
}
|
|
error = cr_canseesocket(req->td->td_ucred, inp->inp_socket);
|
|
if (error)
|
|
goto out;
|
|
cru2x(inp->inp_socket->so_cred, &xuc);
|
|
out:
|
|
INP_UNLOCK(inp);
|
|
outunlocked:
|
|
INP_INFO_RUNLOCK(&tcbinfo);
|
|
splx(s);
|
|
if (error == 0)
|
|
error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
|
|
return (error);
|
|
}
|
|
|
|
SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
|
|
CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
|
|
tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
|
|
#endif
|
|
|
|
|
|
void
|
|
tcp_ctlinput(cmd, sa, vip)
|
|
int cmd;
|
|
struct sockaddr *sa;
|
|
void *vip;
|
|
{
|
|
struct ip *ip = vip;
|
|
struct tcphdr *th;
|
|
struct in_addr faddr;
|
|
struct inpcb *inp;
|
|
struct tcpcb *tp;
|
|
struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
|
|
tcp_seq icmp_seq;
|
|
int s;
|
|
|
|
faddr = ((struct sockaddr_in *)sa)->sin_addr;
|
|
if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
|
|
return;
|
|
|
|
if (cmd == PRC_QUENCH)
|
|
notify = tcp_quench;
|
|
else if (icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
|
|
cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
|
|
notify = tcp_drop_syn_sent;
|
|
else if (cmd == PRC_MSGSIZE)
|
|
notify = tcp_mtudisc;
|
|
else if (PRC_IS_REDIRECT(cmd)) {
|
|
ip = 0;
|
|
notify = in_rtchange;
|
|
} else if (cmd == PRC_HOSTDEAD)
|
|
ip = 0;
|
|
else if ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0)
|
|
return;
|
|
if (ip) {
|
|
s = splnet();
|
|
th = (struct tcphdr *)((caddr_t)ip
|
|
+ (ip->ip_hl << 2));
|
|
INP_INFO_WLOCK(&tcbinfo);
|
|
inp = in_pcblookup_hash(&tcbinfo, faddr, th->th_dport,
|
|
ip->ip_src, th->th_sport, 0, NULL);
|
|
if (inp != NULL) {
|
|
INP_LOCK(inp);
|
|
if (inp->inp_socket != NULL) {
|
|
icmp_seq = htonl(th->th_seq);
|
|
tp = intotcpcb(inp);
|
|
if (SEQ_GEQ(icmp_seq, tp->snd_una) &&
|
|
SEQ_LT(icmp_seq, tp->snd_max))
|
|
inp = (*notify)(inp, inetctlerrmap[cmd]);
|
|
}
|
|
if (inp)
|
|
INP_UNLOCK(inp);
|
|
} else {
|
|
struct in_conninfo inc;
|
|
|
|
inc.inc_fport = th->th_dport;
|
|
inc.inc_lport = th->th_sport;
|
|
inc.inc_faddr = faddr;
|
|
inc.inc_laddr = ip->ip_src;
|
|
#ifdef INET6
|
|
inc.inc_isipv6 = 0;
|
|
#endif
|
|
syncache_unreach(&inc, th);
|
|
}
|
|
INP_INFO_WUNLOCK(&tcbinfo);
|
|
splx(s);
|
|
} else
|
|
in_pcbnotifyall(&tcbinfo, faddr, inetctlerrmap[cmd], notify);
|
|
}
|
|
|
|
#ifdef INET6
|
|
void
|
|
tcp6_ctlinput(cmd, sa, d)
|
|
int cmd;
|
|
struct sockaddr *sa;
|
|
void *d;
|
|
{
|
|
struct tcphdr th;
|
|
struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
|
|
struct ip6_hdr *ip6;
|
|
struct mbuf *m;
|
|
struct ip6ctlparam *ip6cp = NULL;
|
|
const struct sockaddr_in6 *sa6_src = NULL;
|
|
int off;
|
|
struct tcp_portonly {
|
|
u_int16_t th_sport;
|
|
u_int16_t th_dport;
|
|
} *thp;
|
|
|
|
if (sa->sa_family != AF_INET6 ||
|
|
sa->sa_len != sizeof(struct sockaddr_in6))
|
|
return;
|
|
|
|
if (cmd == PRC_QUENCH)
|
|
notify = tcp_quench;
|
|
else if (cmd == PRC_MSGSIZE)
|
|
notify = tcp_mtudisc;
|
|
else if (!PRC_IS_REDIRECT(cmd) &&
|
|
((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
|
|
return;
|
|
|
|
/* if the parameter is from icmp6, decode it. */
|
|
if (d != NULL) {
|
|
ip6cp = (struct ip6ctlparam *)d;
|
|
m = ip6cp->ip6c_m;
|
|
ip6 = ip6cp->ip6c_ip6;
|
|
off = ip6cp->ip6c_off;
|
|
sa6_src = ip6cp->ip6c_src;
|
|
} else {
|
|
m = NULL;
|
|
ip6 = NULL;
|
|
off = 0; /* fool gcc */
|
|
sa6_src = &sa6_any;
|
|
}
|
|
|
|
if (ip6) {
|
|
struct in_conninfo inc;
|
|
/*
|
|
* XXX: We assume that when IPV6 is non NULL,
|
|
* M and OFF are valid.
|
|
*/
|
|
|
|
/* check if we can safely examine src and dst ports */
|
|
if (m->m_pkthdr.len < off + sizeof(*thp))
|
|
return;
|
|
|
|
bzero(&th, sizeof(th));
|
|
m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
|
|
|
|
in6_pcbnotify(&tcb, sa, th.th_dport,
|
|
(struct sockaddr *)ip6cp->ip6c_src,
|
|
th.th_sport, cmd, notify);
|
|
|
|
inc.inc_fport = th.th_dport;
|
|
inc.inc_lport = th.th_sport;
|
|
inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr;
|
|
inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
|
|
inc.inc_isipv6 = 1;
|
|
syncache_unreach(&inc, &th);
|
|
} else
|
|
in6_pcbnotify(&tcb, sa, 0, (const struct sockaddr *)sa6_src,
|
|
0, cmd, notify);
|
|
}
|
|
#endif /* INET6 */
|
|
|
|
|
|
/*
|
|
* Following is where TCP initial sequence number generation occurs.
|
|
*
|
|
* There are two places where we must use initial sequence numbers:
|
|
* 1. In SYN-ACK packets.
|
|
* 2. In SYN packets.
|
|
*
|
|
* All ISNs for SYN-ACK packets are generated by the syncache. See
|
|
* tcp_syncache.c for details.
|
|
*
|
|
* The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
|
|
* depends on this property. In addition, these ISNs should be
|
|
* unguessable so as to prevent connection hijacking. To satisfy
|
|
* the requirements of this situation, the algorithm outlined in
|
|
* RFC 1948 is used to generate sequence numbers.
|
|
*
|
|
* Implementation details:
|
|
*
|
|
* Time is based off the system timer, and is corrected so that it
|
|
* increases by one megabyte per second. This allows for proper
|
|
* recycling on high speed LANs while still leaving over an hour
|
|
* before rollover.
|
|
*
|
|
* net.inet.tcp.isn_reseed_interval controls the number of seconds
|
|
* between seeding of isn_secret. This is normally set to zero,
|
|
* as reseeding should not be necessary.
|
|
*
|
|
*/
|
|
|
|
#define ISN_BYTES_PER_SECOND 1048576
|
|
|
|
u_char isn_secret[32];
|
|
int isn_last_reseed;
|
|
MD5_CTX isn_ctx;
|
|
|
|
tcp_seq
|
|
tcp_new_isn(tp)
|
|
struct tcpcb *tp;
|
|
{
|
|
u_int32_t md5_buffer[4];
|
|
tcp_seq new_isn;
|
|
|
|
/* Seed if this is the first use, reseed if requested. */
|
|
if ((isn_last_reseed == 0) || ((tcp_isn_reseed_interval > 0) &&
|
|
(((u_int)isn_last_reseed + (u_int)tcp_isn_reseed_interval*hz)
|
|
< (u_int)ticks))) {
|
|
read_random(&isn_secret, sizeof(isn_secret));
|
|
isn_last_reseed = ticks;
|
|
}
|
|
|
|
/* Compute the md5 hash and return the ISN. */
|
|
MD5Init(&isn_ctx);
|
|
MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
|
|
MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
|
|
#ifdef INET6
|
|
if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
|
|
MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr,
|
|
sizeof(struct in6_addr));
|
|
MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr,
|
|
sizeof(struct in6_addr));
|
|
} else
|
|
#endif
|
|
{
|
|
MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr,
|
|
sizeof(struct in_addr));
|
|
MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr,
|
|
sizeof(struct in_addr));
|
|
}
|
|
MD5Update(&isn_ctx, (u_char *) &isn_secret, sizeof(isn_secret));
|
|
MD5Final((u_char *) &md5_buffer, &isn_ctx);
|
|
new_isn = (tcp_seq) md5_buffer[0];
|
|
new_isn += ticks * (ISN_BYTES_PER_SECOND / hz);
|
|
return new_isn;
|
|
}
|
|
|
|
/*
|
|
* When a source quench is received, close congestion window
|
|
* to one segment. We will gradually open it again as we proceed.
|
|
*/
|
|
struct inpcb *
|
|
tcp_quench(inp, errno)
|
|
struct inpcb *inp;
|
|
int errno;
|
|
{
|
|
struct tcpcb *tp = intotcpcb(inp);
|
|
|
|
if (tp)
|
|
tp->snd_cwnd = tp->t_maxseg;
|
|
return (inp);
|
|
}
|
|
|
|
/*
|
|
* When a specific ICMP unreachable message is received and the
|
|
* connection state is SYN-SENT, drop the connection. This behavior
|
|
* is controlled by the icmp_may_rst sysctl.
|
|
*/
|
|
struct inpcb *
|
|
tcp_drop_syn_sent(inp, errno)
|
|
struct inpcb *inp;
|
|
int errno;
|
|
{
|
|
struct tcpcb *tp = intotcpcb(inp);
|
|
|
|
if (tp && tp->t_state == TCPS_SYN_SENT) {
|
|
tcp_drop(tp, errno);
|
|
return (struct inpcb *)0;
|
|
}
|
|
return inp;
|
|
}
|
|
|
|
/*
|
|
* When `need fragmentation' ICMP is received, update our idea of the MSS
|
|
* based on the new value in the route. Also nudge TCP to send something,
|
|
* since we know the packet we just sent was dropped.
|
|
* This duplicates some code in the tcp_mss() function in tcp_input.c.
|
|
*/
|
|
struct inpcb *
|
|
tcp_mtudisc(inp, errno)
|
|
struct inpcb *inp;
|
|
int errno;
|
|
{
|
|
struct tcpcb *tp = intotcpcb(inp);
|
|
struct rtentry *rt;
|
|
struct rmxp_tao *taop;
|
|
struct socket *so = inp->inp_socket;
|
|
int offered;
|
|
int mss;
|
|
#ifdef INET6
|
|
int isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
|
|
#endif /* INET6 */
|
|
|
|
if (tp) {
|
|
#ifdef INET6
|
|
if (isipv6)
|
|
rt = tcp_rtlookup6(&inp->inp_inc);
|
|
else
|
|
#endif /* INET6 */
|
|
rt = tcp_rtlookup(&inp->inp_inc);
|
|
if (!rt || !rt->rt_rmx.rmx_mtu) {
|
|
tp->t_maxopd = tp->t_maxseg =
|
|
#ifdef INET6
|
|
isipv6 ? tcp_v6mssdflt :
|
|
#endif /* INET6 */
|
|
tcp_mssdflt;
|
|
return inp;
|
|
}
|
|
taop = rmx_taop(rt->rt_rmx);
|
|
offered = taop->tao_mssopt;
|
|
mss = rt->rt_rmx.rmx_mtu -
|
|
#ifdef INET6
|
|
(isipv6 ?
|
|
sizeof(struct ip6_hdr) + sizeof(struct tcphdr) :
|
|
#endif /* INET6 */
|
|
sizeof(struct tcpiphdr)
|
|
#ifdef INET6
|
|
)
|
|
#endif /* INET6 */
|
|
;
|
|
|
|
if (offered)
|
|
mss = min(mss, offered);
|
|
/*
|
|
* XXX - The above conditional probably violates the TCP
|
|
* spec. The problem is that, since we don't know the
|
|
* other end's MSS, we are supposed to use a conservative
|
|
* default. But, if we do that, then MTU discovery will
|
|
* never actually take place, because the conservative
|
|
* default is much less than the MTUs typically seen
|
|
* on the Internet today. For the moment, we'll sweep
|
|
* this under the carpet.
|
|
*
|
|
* The conservative default might not actually be a problem
|
|
* if the only case this occurs is when sending an initial
|
|
* SYN with options and data to a host we've never talked
|
|
* to before. Then, they will reply with an MSS value which
|
|
* will get recorded and the new parameters should get
|
|
* recomputed. For Further Study.
|
|
*/
|
|
if (tp->t_maxopd <= mss)
|
|
return inp;
|
|
tp->t_maxopd = mss;
|
|
|
|
if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP &&
|
|
(tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP)
|
|
mss -= TCPOLEN_TSTAMP_APPA;
|
|
if ((tp->t_flags & (TF_REQ_CC|TF_NOOPT)) == TF_REQ_CC &&
|
|
(tp->t_flags & TF_RCVD_CC) == TF_RCVD_CC)
|
|
mss -= TCPOLEN_CC_APPA;
|
|
#if (MCLBYTES & (MCLBYTES - 1)) == 0
|
|
if (mss > MCLBYTES)
|
|
mss &= ~(MCLBYTES-1);
|
|
#else
|
|
if (mss > MCLBYTES)
|
|
mss = mss / MCLBYTES * MCLBYTES;
|
|
#endif
|
|
if (so->so_snd.sb_hiwat < mss)
|
|
mss = so->so_snd.sb_hiwat;
|
|
|
|
tp->t_maxseg = mss;
|
|
|
|
tcpstat.tcps_mturesent++;
|
|
tp->t_rtttime = 0;
|
|
tp->snd_nxt = tp->snd_una;
|
|
tcp_output(tp);
|
|
}
|
|
return inp;
|
|
}
|
|
|
|
/*
|
|
* Look-up the routing entry to the peer of this inpcb. If no route
|
|
* is found and it cannot be allocated, then return NULL. This routine
|
|
* is called by TCP routines that access the rmx structure and by tcp_mss
|
|
* to get the interface MTU.
|
|
*/
|
|
struct rtentry *
|
|
tcp_rtlookup(inc)
|
|
struct in_conninfo *inc;
|
|
{
|
|
struct route *ro;
|
|
struct rtentry *rt;
|
|
|
|
ro = &inc->inc_route;
|
|
rt = ro->ro_rt;
|
|
if (rt == NULL || !(rt->rt_flags & RTF_UP)) {
|
|
/* No route yet, so try to acquire one */
|
|
if (inc->inc_faddr.s_addr != INADDR_ANY) {
|
|
ro->ro_dst.sa_family = AF_INET;
|
|
ro->ro_dst.sa_len = sizeof(struct sockaddr_in);
|
|
((struct sockaddr_in *) &ro->ro_dst)->sin_addr =
|
|
inc->inc_faddr;
|
|
rtalloc(ro);
|
|
rt = ro->ro_rt;
|
|
}
|
|
}
|
|
return rt;
|
|
}
|
|
|
|
#ifdef INET6
|
|
struct rtentry *
|
|
tcp_rtlookup6(inc)
|
|
struct in_conninfo *inc;
|
|
{
|
|
struct route_in6 *ro6;
|
|
struct rtentry *rt;
|
|
|
|
ro6 = &inc->inc6_route;
|
|
rt = ro6->ro_rt;
|
|
if (rt == NULL || !(rt->rt_flags & RTF_UP)) {
|
|
/* No route yet, so try to acquire one */
|
|
if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
|
|
ro6->ro_dst.sin6_family = AF_INET6;
|
|
ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6);
|
|
ro6->ro_dst.sin6_addr = inc->inc6_faddr;
|
|
rtalloc((struct route *)ro6);
|
|
rt = ro6->ro_rt;
|
|
}
|
|
}
|
|
return rt;
|
|
}
|
|
#endif /* INET6 */
|
|
|
|
#ifdef IPSEC
|
|
/* compute ESP/AH header size for TCP, including outer IP header. */
|
|
size_t
|
|
ipsec_hdrsiz_tcp(tp)
|
|
struct tcpcb *tp;
|
|
{
|
|
struct inpcb *inp;
|
|
struct mbuf *m;
|
|
size_t hdrsiz;
|
|
struct ip *ip;
|
|
#ifdef INET6
|
|
struct ip6_hdr *ip6;
|
|
#endif /* INET6 */
|
|
struct tcphdr *th;
|
|
|
|
if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
|
|
return 0;
|
|
MGETHDR(m, M_NOWAIT, MT_DATA);
|
|
if (!m)
|
|
return 0;
|
|
|
|
#ifdef INET6
|
|
if ((inp->inp_vflag & INP_IPV6) != 0) {
|
|
ip6 = mtod(m, struct ip6_hdr *);
|
|
th = (struct tcphdr *)(ip6 + 1);
|
|
m->m_pkthdr.len = m->m_len =
|
|
sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
|
|
tcp_fillheaders(tp, ip6, th);
|
|
hdrsiz = ipsec6_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
|
|
} else
|
|
#endif /* INET6 */
|
|
{
|
|
ip = mtod(m, struct ip *);
|
|
th = (struct tcphdr *)(ip + 1);
|
|
m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr);
|
|
tcp_fillheaders(tp, ip, th);
|
|
hdrsiz = ipsec4_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
|
|
}
|
|
|
|
m_free(m);
|
|
return hdrsiz;
|
|
}
|
|
#endif /*IPSEC*/
|
|
|
|
/*
|
|
* Return a pointer to the cached information about the remote host.
|
|
* The cached information is stored in the protocol specific part of
|
|
* the route metrics.
|
|
*/
|
|
struct rmxp_tao *
|
|
tcp_gettaocache(inc)
|
|
struct in_conninfo *inc;
|
|
{
|
|
struct rtentry *rt;
|
|
|
|
#ifdef INET6
|
|
if (inc->inc_isipv6)
|
|
rt = tcp_rtlookup6(inc);
|
|
else
|
|
#endif /* INET6 */
|
|
rt = tcp_rtlookup(inc);
|
|
|
|
/* Make sure this is a host route and is up. */
|
|
if (rt == NULL ||
|
|
(rt->rt_flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST))
|
|
return NULL;
|
|
|
|
return rmx_taop(rt->rt_rmx);
|
|
}
|
|
|
|
/*
|
|
* Clear all the TAO cache entries, called from tcp_init.
|
|
*
|
|
* XXX
|
|
* This routine is just an empty one, because we assume that the routing
|
|
* routing tables are initialized at the same time when TCP, so there is
|
|
* nothing in the cache left over.
|
|
*/
|
|
static void
|
|
tcp_cleartaocache()
|
|
{
|
|
}
|
|
|
|
/*
|
|
* TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING
|
|
*
|
|
* This code attempts to calculate the bandwidth-delay product as a
|
|
* means of determining the optimal window size to maximize bandwidth,
|
|
* minimize RTT, and avoid the over-allocation of buffers on interfaces and
|
|
* routers. This code also does a fairly good job keeping RTTs in check
|
|
* across slow links like modems. We implement an algorithm which is very
|
|
* similar (but not meant to be) TCP/Vegas. The code operates on the
|
|
* transmitter side of a TCP connection and so only effects the transmit
|
|
* side of the connection.
|
|
*
|
|
* BACKGROUND: TCP makes no provision for the management of buffer space
|
|
* at the end points or at the intermediate routers and switches. A TCP
|
|
* stream, whether using NewReno or not, will eventually buffer as
|
|
* many packets as it is able and the only reason this typically works is
|
|
* due to the fairly small default buffers made available for a connection
|
|
* (typicaly 16K or 32K). As machines use larger windows and/or window
|
|
* scaling it is now fairly easy for even a single TCP connection to blow-out
|
|
* all available buffer space not only on the local interface, but on
|
|
* intermediate routers and switches as well. NewReno makes a misguided
|
|
* attempt to 'solve' this problem by waiting for an actual failure to occur,
|
|
* then backing off, then steadily increasing the window again until another
|
|
* failure occurs, ad-infinitum. This results in terrible oscillation that
|
|
* is only made worse as network loads increase and the idea of intentionally
|
|
* blowing out network buffers is, frankly, a terrible way to manage network
|
|
* resources.
|
|
*
|
|
* It is far better to limit the transmit window prior to the failure
|
|
* condition being achieved. There are two general ways to do this: First
|
|
* you can 'scan' through different transmit window sizes and locate the
|
|
* point where the RTT stops increasing, indicating that you have filled the
|
|
* pipe, then scan backwards until you note that RTT stops decreasing, then
|
|
* repeat ad-infinitum. This method works in principle but has severe
|
|
* implementation issues due to RTT variances, timer granularity, and
|
|
* instability in the algorithm which can lead to many false positives and
|
|
* create oscillations as well as interact badly with other TCP streams
|
|
* implementing the same algorithm.
|
|
*
|
|
* The second method is to limit the window to the bandwidth delay product
|
|
* of the link. This is the method we implement. RTT variances and our
|
|
* own manipulation of the congestion window, bwnd, can potentially
|
|
* destabilize the algorithm. For this reason we have to stabilize the
|
|
* elements used to calculate the window. We do this by using the minimum
|
|
* observed RTT, the long term average of the observed bandwidth, and
|
|
* by adding two segments worth of slop. It isn't perfect but it is able
|
|
* to react to changing conditions and gives us a very stable basis on
|
|
* which to extend the algorithm.
|
|
*/
|
|
void
|
|
tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq)
|
|
{
|
|
u_long bw;
|
|
u_long bwnd;
|
|
int save_ticks;
|
|
|
|
/*
|
|
* If inflight_enable is disabled in the middle of a tcp connection,
|
|
* make sure snd_bwnd is effectively disabled.
|
|
*/
|
|
if (tcp_inflight_enable == 0) {
|
|
tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
|
|
tp->snd_bandwidth = 0;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Figure out the bandwidth. Due to the tick granularity this
|
|
* is a very rough number and it MUST be averaged over a fairly
|
|
* long period of time. XXX we need to take into account a link
|
|
* that is not using all available bandwidth, but for now our
|
|
* slop will ramp us up if this case occurs and the bandwidth later
|
|
* increases.
|
|
*
|
|
* Note: if ticks rollover 'bw' may wind up negative. We must
|
|
* effectively reset t_bw_rtttime for this case.
|
|
*/
|
|
save_ticks = ticks;
|
|
if ((u_int)(save_ticks - tp->t_bw_rtttime) < 1)
|
|
return;
|
|
|
|
bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz /
|
|
(save_ticks - tp->t_bw_rtttime);
|
|
tp->t_bw_rtttime = save_ticks;
|
|
tp->t_bw_rtseq = ack_seq;
|
|
if (tp->t_bw_rtttime == 0 || (int)bw < 0)
|
|
return;
|
|
bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4;
|
|
|
|
tp->snd_bandwidth = bw;
|
|
|
|
/*
|
|
* Calculate the semi-static bandwidth delay product, plus two maximal
|
|
* segments. The additional slop puts us squarely in the sweet
|
|
* spot and also handles the bandwidth run-up case and stabilization.
|
|
* Without the slop we could be locking ourselves into a lower
|
|
* bandwidth.
|
|
*
|
|
* Situations Handled:
|
|
* (1) Prevents over-queueing of packets on LANs, especially on
|
|
* high speed LANs, allowing larger TCP buffers to be
|
|
* specified, and also does a good job preventing
|
|
* over-queueing of packets over choke points like modems
|
|
* (at least for the transmit side).
|
|
*
|
|
* (2) Is able to handle changing network loads (bandwidth
|
|
* drops so bwnd drops, bandwidth increases so bwnd
|
|
* increases).
|
|
*
|
|
* (3) Theoretically should stabilize in the face of multiple
|
|
* connections implementing the same algorithm (this may need
|
|
* a little work).
|
|
*
|
|
* (4) Stability value (defaults to 20 = 2 maximal packets) can
|
|
* be adjusted with a sysctl but typically only needs to be
|
|
* on very slow connections. A value no smaller then 5
|
|
* should be used, but only reduce this default if you have
|
|
* no other choice.
|
|
*/
|
|
#define USERTT ((tp->t_srtt + tp->t_rttbest) / 2)
|
|
bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + tcp_inflight_stab * tp->t_maxseg / 10;
|
|
#undef USERTT
|
|
|
|
if (tcp_inflight_debug > 0) {
|
|
static int ltime;
|
|
if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) {
|
|
ltime = ticks;
|
|
printf("%p bw %ld rttbest %d srtt %d bwnd %ld\n",
|
|
tp,
|
|
bw,
|
|
tp->t_rttbest,
|
|
tp->t_srtt,
|
|
bwnd
|
|
);
|
|
}
|
|
}
|
|
if ((long)bwnd < tcp_inflight_min)
|
|
bwnd = tcp_inflight_min;
|
|
if (bwnd > tcp_inflight_max)
|
|
bwnd = tcp_inflight_max;
|
|
if ((long)bwnd < tp->t_maxseg * 2)
|
|
bwnd = tp->t_maxseg * 2;
|
|
tp->snd_bwnd = bwnd;
|
|
}
|
|
|