.TH TCPBRIDGE 1 2006-07-17 "" "Programmer's Manual" .\" DO NOT EDIT THIS FILE (tcpbridge.1) .\" .\" It has been AutoGen-ed Monday July 17, 2006 at 06:48:26 PM PDT .\" From the definitions tcpbridge_opts.def .\" and the template file agman1.tpl .\" .SH NAME tcpbridge \- Bridge network traffic across two interfaces .SH SYNOPSIS .B tcpbridge .\" Mixture of short (flag) options and long options .RB [ -\fIflag\fP " [\fIvalue\fP]]... [" --\fIopt-name\fP " [[=| ]\fIvalue\fP]]..." .PP All arguments must be options. .PP tcpbridge is a tool for briding network traffic across two interfaces and optionally modifying the packets in betweeen .SH "DESCRIPTION" This manual page documents, briefly, the \fBtcpbridge\fP command. The basic operation of tcpbridge is to be a network bridge between two subnets. All packets received on one interface are sent via the other. Optionally, packets can be edited in a variety of ways according to your needs. .SH OPTIONS .TP .BR -D " \fIstring\fP, " --dmac "=" \fIstring\fP Rewrite destination MAC addresses. This option may appear up to 1 times. .sp Takes a pair of comma deliminated ethernet MAC addresses which will replace the destination MAC address of outbound packets. The first MAC address will be used for the server traffic and the optional second MAC address will be used for the client traffic. Example: .nf --dmac 00:12:13:14:15:16,00:22:33:44:55:66 .fi .TP .BR -S " \fIstring\fP, " --smac "=" \fIstring\fP Rewrite source MAC addresses. This option may appear up to 1 times. .sp Takes a pair of comma deliminated ethernet MAC addresses which will replace the source MAC address of outbound packets. The first MAC address will be used for the server traffic and the optional second MAC address will be used for the client traffic. Example: .nf --smac 00:12:13:14:15:16,00:22:33:44:55:66 .fi .TP .BR -P " \fInumber\fP, " --proto "=" \fInumber\fP Override L2 protocol type for DLT_RAW. This option may appear up to 1 times. This option takes an integer number as its argument. The value of \fInumber\fP is constrained to being: .in +4 .nf .na in the range 0 through 65535 .fi .in -4 .sp By default, pcap files encapsulated using DLT_RAW will have their protocol set to ETHERTYPE_IP (0x0800). .TP .BR -l " \fIstring\fP, " --dlink "=" \fIstring\fP Rewrite Data-Link layer with specified data. This option may appear up to 2 times. .sp Provide a series of comma deliminated hex values which will be used to rewrite or create the Layer 2 header of the packets. The first instance of this argument will rewrite both server and client traffic, but if this argument is specified a second time, it will be used for the client traffic. Example: .nf --dlink=01,02,03,04,05,06,00,1A,2B,3C,4D,5E,6F,08,00 .fi .TP .BR -r " \fIstring\fP, " --portmap "=" \fIstring\fP Rewrite TCP/UDP ports. This option may appear up to 1 times. .sp Specify a list of comma delimited port mappingings consisting of colon delimited port number pairs. Each colon delimited port pair consists of the port to match followed by the port number to rewrite. Example: .nf --portmap=80:8000,8080:80 .fi .TP .BR -s " \fInumber\fP, " --seed "=" \fInumber\fP Randomize src/dst IP addresses w/ given seed. This option may appear up to 1 times. This option takes an integer number as its argument. .sp Causes the source and destination IP addresses to be pseudo randomized but still maintain client/server relationships. Since the randomization is deterministic based on the seed, you can reuse the same seed value to recreate the traffic. .TP .BR -N " \fIstring\fP, " --pnat "=" \fIstring\fP Rewrite IP addresses using pseudo-NAT. This option may appear up to 2 times. .sp Takes a comma delimited series of colon delimited CIDR netblock pairs. Each netblock pair is evaluated in order against the IP addresses. If the IP address in the packet matches the first netblock, it is rewriten using the second netblock as a mask against the high order bits. Example: .nf --pnat=192.168.0.0/16:10.77.0.0/16,172.16.0.0/12:10.1.0.0/24 .fi .TP .BR -e " \fIstring\fP, " --endpoints "=" \fIstring\fP Rewrite IP addresses to be between two endpoints. This option may appear up to 1 times. .sp Takes a pair of colon delimited IP addresses which will be used to rewrite all traffic to appear to be between the two IP's. Example: .nf --endpoints=172.16.0.1:172.16.0.2 .fi .TP .BR -C ", " --fixcsum Force recalculation of IP/TCP/UDP checksums. .sp Causes each IP packet to have it's checksums recalcualted and fixed. Automatically enabled for packets modified with \fB--seed\fP, \fB--pnat\fP, \fB--endpoints\fP or \fB--fixlen\fP. .TP .BR -m " \fInumber\fP, " --mtu "=" \fInumber\fP Override default MTU length (1500 bytes). This option may appear up to 1 times. This option takes an integer number as its argument. The value of \fInumber\fP is constrained to being: .in +4 .nf .na in the range 1 through MAXPACKET .fi .in -4 .sp Override the default 1500 byte MTU size for determining the maximum padding length. .TP .BR -E ", " --efcs Remove Ethernet checksums (FCS) from end of frames. .sp .TP .BR -F " \fIstring\fP, " --fixlen "=" \fIstring\fP Pad or truncate packet data to match header length. This option may appear up to 1 times. .sp Packets may be truncated during capture if the snaplen is smaller then the packet. This option allows you to modify the packet to pad the packet back out to the size stored in the IPv4 header or rewrite the IP header total length to reflect the stored packet length. .sp 1 \fBpad\fP Truncated packets will be padded out so that the packet length matches the IPv4 total length .sp 1 \fBtrunc\fP Truncated packets will have their IPv4 total length field rewritten to match the actual packet length .sp 1 \fBdel\fP Delete the packet .TP .BR -T " \fIstring\fP, " --vlan "=" \fIstring\fP Specify 802.1q VLAN tag mode. This option may appear up to 1 times. .sp Allows you to rewrite ethernet frames to add a 802.1q header to standard 802.3 ethernet headers or remove the 802.1q VLAN tag information. .sp 1 \fBadd\fP Rewrites the existing 802.3 ethernet header as an 802.1q VLAN header .sp 1 \fBdel\fP Rewrites the existing 802.1q VLAN header as an 802.3 ethernet header .TP .BR -t " \fInumber\fP, " --vlan-tag "=" \fInumber\fP Specify the new 802.1q VLAN tag value. This option may appear up to 1 times. This option must appear in combination with the following options: vlan. This option takes an integer number as its argument. The value of \fInumber\fP is constrained to being: .in +4 .nf .na in the range 0 through 4095 .fi .in -4 .sp .TP .BR -f " \fInumber\fP, " --vlan-cfi "=" \fInumber\fP Specify the 802.1q VLAN CFI value. This option may appear up to 1 times. This option must appear in combination with the following options: vlan. This option takes an integer number as its argument. The value of \fInumber\fP is constrained to being: .in +4 .nf .na in the range 0 through 1 .fi .in -4 .sp .TP .BR -p " \fInumber\fP, " --vlan-pri "=" \fInumber\fP Specify the 802.1q VLAN priority. This option may appear up to 1 times. This option must appear in combination with the following options: vlan. This option takes an integer number as its argument. The value of \fInumber\fP is constrained to being: .in +4 .nf .na in the range 0 through 7 .fi .in -4 .sp .TP .BR -d " \fInumber\fP, " --dbug "=" \fInumber\fP Enable debugging output. This option may appear up to 1 times. This option takes an integer number as its argument. The value of \fInumber\fP is constrained to being: .in +4 .nf .na in the range 0 through 5 .fi .in -4 The default \fInumber\fP for this option is: .ti +4 0 .sp If configured with --enable-debug, then you can specify a verbosity level for debugging output. Higher numbers increase verbosity. .TP .BR -i " \fIstring\fP, " --intf1 "=" \fIstring\fP Primary interface (listen in uni-directional mode). This option may appear up to 1 times. .sp .TP .BR -I " \fIstring\fP, " --intf2 "=" \fIstring\fP Secondary interface (send in uni-directional mode). This option may appear up to 1 times. .sp .TP .BR -u ", " --unidir Send and receive in only one direction. This option may appear up to 1 times. .sp Normally, tcpbridge will send and receive traffic in both directions (bi-directionally). However, if you choose this option, traffic will be sent uni-directionally. .TP .BR -L " \fInumber\fP, " --limit "=" \fInumber\fP Limit the number of packets to send. This option may appear up to 1 times. This option takes an integer number as its argument. The value of \fInumber\fP is constrained to being: .in +4 .nf .na greater than or equal to 0 .fi .in -4 The default \fInumber\fP for this option is: .ti +4 -1 .sp By default, tcpbridge will send packets forever or until Ctrl-C. Alternatively, you can specify a maximum number of packets to send. .TP .BR -x " \fIstring\fP, " --include "=" \fIstring\fP Include only packets matching rule. This option may appear up to 1 times. This option must not appear in combination with any of the following options: exclude. .sp Override default of sending all packets stored in the capture file and only send packets which match the provided rule. Rules can be one of: .sp .IR "S:,... " - Source IP must match specified CIDR(s) .sp .IR "D:,... " - Destination IP must match specified CIDR(s) .sp .IR "B:,... " - Both source and destination IP must match specified CIDR(s) .sp .IR "E:,... " - Either IP must match specified CIDR(s) .sp .IR "P: " - Must be one of the listed packets where the list corresponds to the packet number in the capture file. .nf --include=P:1-5,9,15,72- .fi would send packets 1 thru 5, the 9th and 15th packet, and packets 72 until the end of the file .sp .IR "F:''" - BPF filter. See the \fItcpdump(8)\fP man page for syntax. .br .TP .BR -X " \fIstring\fP, " --exclude "=" \fIstring\fP Exclude any packet matching this rule. This option may appear up to 1 times. This option must not appear in combination with any of the following options: include. .sp Override default of sending all packets stored in the capture file and only send packets which do not match the provided rule. Rules can be one of: .sp .IR "S:,... " - Source IP must not match specified CIDR(s) .sp .IR "D:,... " - Destination IP must not match specified CIDR(s) .sp .IR "B:,... " - Both source and destination IP must not match specified CIDR(s) .sp .IR "E:,... " - Either IP must not match specified CIDR(s) .sp .IR "P: " - Must not be one of the listed packets where the list corresponds to the packet number in the capture file. .nf --exclude=P:1-5,9,15,72- .fi would drop packets 1 thru 5, the 9th and 15th packet, and packets 72 until the end of the file .br .TP .BR -P ", " --pid Print the PID of tcpbridge at startup. .sp .TP .BR -v ", " --verbose Print decoded packets via tcpdump to STDOUT. This option may appear up to 1 times. .sp .TP .BR -A " \fIstring\fP, " --decode "=" \fIstring\fP Arguments passed to tcpdump decoder. This option may appear up to 1 times. This option must appear in combination with the following options: verbose. .sp When enabling verbose mode (\fB-v\fP) you may also specify one or more additional arguments to pass to \fBtcpdump\fP to modify the way packets are decoded. By default, -n and -l are used. Be sure to quote the arguments like: --verbose="-axxx" so that they are not interpreted by tcpbridge. The following arguments are vaild: [ -aAeNqRStuvxX ] [ -E spi@ipaddr algo:secret,... ] [ -s snaplen ] .TP .BR -V ", " --version Print version information. .sp .TP .BR -h ", " --less-help Display less usage information and exit. .sp .TP .BR \-H , " \--help" Display usage information and exit. .TP .BR \-! , " \--more-help" Extended usage information passed thru pager. .TP .BR \- " [\fIrcfile\fP]," " \--save-opts" "[=\fIrcfile\fP]" Save the option state to \fIrcfile\fP. The default is the \fIlast\fP configuration file listed in the \fBOPTION PRESETS\fP section, below. .TP .BR \- " \fIrcfile\fP," " \--load-opts" "=\fIrcfile\fP," " --no-load-opts" Load options from \fIrcfile\fP. The \fIno-load-opts\fP form will disable the loading of earlier RC/INI files. \fI--no-load-opts\fP is handled early, out of order. .SH OPTION PRESETS Any option that is not marked as \fInot presettable\fP may be preset by loading values from configuration ("RC" or ".INI") file(s). The \fIhomerc\fP file is "\fI$$/\fP", unless that is a directory. In that case, the file "\fI.tcpbridgerc\fP" is searched for within that directory. .SH "SIGNALS" tcpbridge understands the following signals: .sp .IR "\fBSIGUSR1\fP" Suspend tcpbridge .sp .IR "\fBSIGCONT\fP" Restart tcpbridge .br .SH "SEE ALSO" tcpdump(1), tcpprep(1), tcprewrite(1), tcpreplay(1) .SH "BUGS" tcpbridge can only send packets as fast as your computer's interface, processor and system bus will allow. Connecting both interfaces to the same subnet may create a broadcast storm and take down the network. Improper use of the packet editing functions may have other undefined and possible negative consequences. Some operating systems by default do not allow for forging source MAC addresses. Please consult your operating system's documentation and the tcpreplay FAQ if you experiance this issue. .SH AUTHOR Copyright 2000-2005 Aaron Turner For support please use the tcpreplay-users@lists.sourceforge.net mailing list. .PP Released under the Free BSD License. .PP This manual page was \fIAutoGen\fP-erated from the \fBtcpbridge\fP option definitions.