[tor-dev] New Fallback Directory File Format

teor teor2345 at gmail.com
Wed Dec 27 10:53:42 UTC 2017

> On 26 Dec 2017, at 18:47, teor <teor2345 at gmail.com> wrote:
>> On 25 Dec 2017, at 07:26, Iain Learmonth <irl at torproject.org> wrote:
>> As we are planning to also add a parser to metrics-lib (#24434), would
>> it be possible to get a full description of the format of the file
>> possibly in RFC5234 format so that we can check that the generator and
>> parsers all match up to that specification?
> I have written up a format in the standard torspec style:
> https://github.com/teor2345/torspec/blob/fallback-format-2/fallback-spec.txt
> It is deliberately under-specified, please let me know if this causes
> any trouble when writing the parser, and I will tighten it up.
> It's not ABNF/RFC5234, it's rather restrictive, and strict ABNF is
> unreadable for case sensitive strings. I am happy to put an ABNF spec in
> an appendix, if someone wants to write one.

We've added separators to each section, and a timestamp field in the header.

The revised spec is here:


The revised sample file is here:


We're tracking the details in this ticket:



Tim Wilson-Brown (teor)

teor2345 at gmail dot com
PGP C855 6CED 5D90 A0C5 29F6 4D43 450C BA7F 968F 094B
xmpp: teor at torproject dot org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Message signed with OpenPGP
URL: <http://lists.torproject.org/pipermail/tor-dev/attachments/20171227/56439f70/attachment.sig>

More information about the tor-dev mailing list