IPSEC_EROUTE

DESCRIPTION

Eroute manages the IPSEC extended routing tables, which control what (if any) processing is applied to non-encrypted packets arriving for IPSEC processing and forwarding. The form with no additional arguments lists the contents of /proc/net/ipsec_eroute. The --add form adds a table entry, the --replace form replaces a table entry, while the --del form deletes one. The --clear form deletes the entire table.

A table entry consists of:

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source and destination addresses, with masks, source and destination ports and protocol for selection of packets. The source and destination ports are only legal if the transport protocol is TCP or UDP. A port can be specified as either decimal, hexadecimal (leading 0x), octal (leading 0) or a name listed in the first column of /etc/services. A transport protocol can be specified as either decimal, hexadecimal (leading 0x), octal (leading 0) or a name listed in the first column of /etc/protocols. If a transport protocol or port is not specified then it defaults to 0 which means all protocols or all ports respectively.

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Security Association IDentifier, comprised of:

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protocol (proto), indicating (together with the effective destination and the security parameters index) which Security Association should be used to process the packet

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address family (af),

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Security Parameters Index (spi), indicating (together with the effective destination and protocol) which Security Association should be used to process the packet (must be larger than or equal to 0x100)

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effective destination (edst), where the packet should be forwarded after processing (normally the other security gateway)

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OR

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SAID (said), indicating which Security Association should be used to process the packet

Addresses are written as IPv4 dotted quads or IPv6 coloned hex, protocol is one of "ah", "esp", "comp" or "tun" and SPIs are prefixed hexadecimal numbers where '.' represents IPv4 and ':' stands for IPv6.

SAIDs are written as "protoafSPI@address". There are also five "magic" SAIDs that have special meaning:

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%drop means that matches are to be dropped

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%reject means that matches are to be dropped and an ICMP returned, if possible to inform

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%trap means that matches are to trigger an ACQUIRE message to the Key Management daemon(s) and a hold eroute will be put in place to prevent subsequent packets also triggering ACQUIRE messages.

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%hold means that matches are to stored until the eroute is replaced or until that eroute gets reaped

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%pass means that matches are to allowed to pass without IPSEC processing

The format of /proc/net/ipsec_eroute is listed in ipsec_eroute(5).  

EXAMPLES

ipsec eroute --add --eraf inet --src 192.168.0.1/32 \

--dst 192.168.2.0/24 --af inet --edst 192.168.0.2 \

--spi 0x135 --proto tun

sets up an eroute on a Security Gateway to protect traffic between the host 192.168.0.1 and the subnet 192.168.2.0 with 24 bits of subnet mask via Security Gateway 192.168.0.2 using the Security Association with address 192.168.0.2, Security Parameters Index 0x135 and protocol tun (50, IPPROTO_ESP).

ipsec eroute --add --eraf inet6 --src 3049:1::1/128 \

--dst 3049:2::/64 --af inet6 --edst 3049:1::2 \

--spi 0x145 --proto tun

sets up an eroute on a Security Gateway to protect traffic between the host 3049:1::1 and the subnet 3049:2:: with 64 bits of subnet mask via Security Gateway 3049:1::2 using the Security Association with address 3049:1::2, Security Parameters Index 0x145 and protocol tun (50, IPPROTO_ESP).

ipsec eroute --replace --eraf inet --src company.com/24 \

--dst ftp.ngo.org/32 --said tun.135@gw.ngo.org

replaces an eroute on a Security Gateway to protect traffic between the subnet company.com with 24 bits of subnet mask and the host ftp.ngo.org via Security Gateway gw.ngo.org using the Security Association with Security Association ID tun0x135@gw.ngo.org

ipsec eroute --del --eraf inet --src company.com/24 \

--dst www.ietf.org/32 --said %passthrough4

deletes an eroute on a Security Gateway that allowed traffic between the subnet company.com with 24 bits of subnet mask and the host www.ietf.org to pass in the clear, unprocessed.

ipsec eroute --add --eraf inet --src company.com/24 \

--dst mail.ngo.org/32 --transport-proto 6 \

--dst-port 110 --said tun.135@mail.ngo.org

sets up an eroute on on a Security Gateway to protect only TCP traffic on port 110 (pop3) between the subnet company.com with 24 bits of subnet mask and the host ftp.ngo.org via Security Gateway mail.ngo.org using the Security Association with Security Association ID tun0x135@mail.ngo.org. Note that any other traffic bound for mail.ngo.org that is routed via the ipsec device will be dropped. If you wish to allow other traffic to pass through then you must add a %pass rule. For example the following rule when combined with the above will ensure that POP3 messages read from mail.ngo.org will be encrypted but all other traffic to/from mail.ngo.org will be in clear text.

ipsec eroute --add --eraf inet --src company.com/24 \

--dst mail.ngo.org/32 --said %pass  

FILES

/proc/net/ipsec_eroute, /usr/local/bin/ipsec  

SEE ALSO

ipsec(8), ipsec_tncfg(8), ipsec_spi(8), ipsec_spigrp(8), ipsec_klipsdebug(8), ipsec_eroute(5)  

HISTORY

Written for the Linux FreeS/WAN project <m[blue]http://www.freeswan.org/m[]> by Richard Guy Briggs.  

AUTHOR

Paul Wouters

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