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diff --git a/share/man/man4/faith.4 b/share/man/man4/faith.4 new file mode 100644 index 000000000000..3f13cd662554 --- /dev/null +++ b/share/man/man4/faith.4 @@ -0,0 +1,134 @@ +.\" $KAME: faith.4,v 1.9 2001/04/27 17:26:35 itojun Exp $ +.\" +.\" Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. +.\" All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. Neither the name of the project nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" $FreeBSD$ +.\" +.Dd April 10, 1999 +.Dt FAITH 4 +.Os +.Sh NAME +.Nm faith +.Nd IPv6-to-IPv4 TCP relay capturing interface +.Sh SYNOPSIS +.Cd "device faith" +.Sh DESCRIPTION +The +.Nm +interface captures IPv6 TCP traffic, +for implementing userland IPv6-to-IPv4 TCP relay +like +.Xr faithd 8 . +.Pp +Each +.Nm +interface is created at runtime using interface cloning. +This is +most easily done with the +.Xr ifconfig 8 +.Cm create +command or using the +.Va cloned_interfaces +variable in +.Xr rc.conf 5 . +.Pp +Special action will be taken when IPv6 TCP traffic is seen on a router, +and routing table suggests to route it to +.Nm +interface. +In this case, the packet will be accepted by the router, +regardless of list of IPv6 interface addresses assigned to the router. +The packet will be captured by an IPv6 TCP socket, if it has +.Dv IN6P_FAITH +flag turned on and it has matching address/port pairs. +In result, +.Nm +will let you capture IPv6 TCP traffic to some specific destination addresses. +Userland programs, such as +.Xr faithd 8 +can use this behavior to relay IPv6 TCP traffic to IPv4 TCP traffic. +The program can accept some specific IPv6 TCP traffic, perform +.Xr getsockname 2 +to get the IPv6 destination address specified by the client, +and perform application-specific address mapping to relay IPv6 TCP to IPv4 TCP. +.Pp +The +.Dv IN6P_FAITH +flag on IPv6 TCP socket can be set by using +.Xr setsockopt 2 , +with level equals to +.Dv IPPROTO_IPV6 +and optname equals to +.Dv IPv6_FAITH . +.Pp +To handle error reports by ICMPv6, some of ICMPv6 packets routed to +.Nm +interface will be delivered to IPv6 TCP, as well. +.Pp +To understand how +.Nm +can be used, take a look at source code of +.Xr faithd 8 . +.Pp +As +.Nm +interface implements potentially dangerous operation, +great care must be taken when configuring +.Nm +interface. +To avoid possible misuse, +.Xr sysctl 8 +variable +.Li net.inet6.ip6.keepfaith +must be set to +.Li 1 +prior to the use of the interface. +When +.Li net.inet6.ip6.keepfaith +is +.Li 0 , +no packet will be captured by +.Nm +interface. +.Pp +.Nm +interface is intended to be used on routers, not on hosts. +.\" +.Sh SEE ALSO +.Xr inet 4 , +.Xr inet6 4 , +.Xr faithd 8 +.Rs +.%A Jun-ichiro itojun Hagino +.%A Kazu Yamamoto +.%T "An IPv6-to-IPv4 transport relay translator" +.%O RFC3142 +.Re +.Sh HISTORY +The FAITH IPv6-to-IPv4 TCP relay translator was first appeared in +WIDE hydrangea IPv6 stack. |