Cheers, I have managed to hack something together which seems to work, and I am getting the decode I expect after I modified the dictionary.dhcp to have the DHCP-Relay-Circuit-Id and DHCP-Relay-Remote-Id to be string rather than octet.

++[files] returns ok
        DHCP-Message-Type += DHCP-Discover
        DHCP-Client-Identifier += 00:19:c7:f9:fb:df
        DHCP-Vendor-Class-Identifier += "dslforum.org"
        DHCP-DHCP-Maximum-Msg-Size += 576
        DHCP-Parameter-Request-List += DHCP-Subnet-Mask
        DHCP-Parameter-Request-List += DHCP-Router-Address
        DHCP-Parameter-Request-List += DHCP-Domain-Name-Server
        DHCP-Parameter-Request-List += DHCP-Hostname
        DHCP-Parameter-Request-List += DHCP-Domain-Name
        DHCP-Parameter-Request-List += DHCP-Broadcast-Address
        DHCP-Parameter-Request-List += DHCP-NTP-Servers
        DHCP-Parameter-Request-List += DHCP-Vendor
        DHCP-Parameter-Request-List += DHCP-TFTP-Server-Name
        DHCP-Relay-Circuit-Id = "WN-POLT01 eth 1/1/01/05/5/14/1:10"
        DHCP-Relay-Remote-Id = "CHORUS1634567895"
        expand: %{dhcp_options:ERX-Dhcp-Options} -> 15
++[request] returns ok

Which is brilliant :)

Now I just need to figure out how to re-encode into the hex string from the TLVs of Option 43.

I think this may be the only way.

Ideally I would like to reverse what the decode is doing, and be able to set TLV VSAs and have the regex preform the opposite.  But my c fu isn't that strong so I am going to hunt down someone who may be able to help.

IE going from:

        DHCP-Vendor-ACS = "http://sip.config.co.nz:8080/openacs/acs"
        DHCP-Vendor-User = "USR1"
        DHCP-Vendor-Password = "USR1"

With this in the dictionary.dhcp:

# N Vendor Specific Information
ATTRIBUTE       DHCP-Vendor                             43      tlv
BEGIN-TLV       DHCP-Vendor
ATTRIBUTE       DHCP-Vendor-ACS                         1       string
ATTRIBUTE       DHCP-Vendor-User                        2       string
ATTRIBUTE       DHCP-Vendor-Password                    254     string
END-TLV         DHCP-Vendor


Using something like:

        update reply {
                ERX-Dhcp-Options := "%{encode_dhcp_options:DHCP-Vendor-ACS,DHCP-Vendor-User,DHCP-Vendor-Password}"
        }

Or just specify the top level VSA so the encode knows to take all the TLVs underneath so:

        update reply {
                ERX-Dhcp-Options := "%{encode_dhcp_options:DHCP-Vendor}"
        }

Would suffice and end up with something like:

ERX-Dhcp-Options := 0x2b360128687474703a2f2f7369702e636f6e6669672e636f2e6e7a3a383038302f6f70656e6163732f616373020455535231fe0455535231

That would be handy :)