commit d29d9ada0bf86167edc647285534b8d75890a593 Author: teor <teor2345@gmail.com> Date: Mon Jul 16 10:16:18 2018 +1000 bandwidth: edit bandwidth URL dir-spec and proposal * dir-spec: don't post bandwidth files to other authorities * dir-spec: add URL for current bandwidth file * dir-spec: clean up the consensus and vote "current" publication schedule Closes ticket #21377. --- dir-spec.txt | 26 +++++++------- ...th_votes.txt => xxx-expose-bandwidth-files.txt} | 41 ++++++++++++++-------- 2 files changed, 39 insertions(+), 28 deletions(-) diff --git a/dir-spec.txt b/dir-spec.txt index 388ad04..df74ca8 100644 --- a/dir-spec.txt +++ b/dir-spec.txt @@ -2607,19 +2607,19 @@ http://<hostname>/tor/status-vote/next/bandwidth.z at the start of each voting period. + + It MUST NOT attempt to send its bandwidth list file in a HTTP POST to + other authorities and it SHOULD NOT make bandwidth list files from other + authorities available. + If an authority makes this file available, it MUST be the bandwidth file used to create the vote document available at http://<hostname>/tor/status-vote/next/authority.z - Once the voting period starts, the bandwidth list file SHOULD be available - at + The bandwidth list format is described in bandwidth-file-spec.txt. - http://<hostname>/tor/status-vote/next/bandwidth.z - - The bandwidth list file is described in bandwidth-file-spec.txt. - - First-appeared in Tor 0.3.5. + The standard URLs for bandwidth list files first-appeared in Tor 0.3.5. 3.5. Downloading missing certificates from other directory authorities @@ -3343,16 +3343,14 @@ 3.11. Publishing the signed consensus - Once there are enough signatures, or once the voting period starts, - these documents are available at + The voting period ends at the valid-after time. If the consensus has + been signed by a majority of authorities, these documents are made + available at http://<hostname>/tor/status-vote/current/consensus.z and http://<hostname>/tor/status-vote/current/consensus-signatures.z [XXX current/consensus-signatures is not currently implemented, as it is not used in the voting protocol.] - [XXX It's actually false that the first document is available as soon - as there are enough signatures. It's only available as soon as the - voting period starts. -KL] [XXX possible future features include support for downloading old consensuses.] @@ -3361,13 +3359,15 @@ http://<hostname>/tor/status-vote/current/authority.z http://<hostname>/tor/status-vote/current/<fp>.z http://<hostname>/tor/status-vote/current/d/<d>.z - once the consensus is complete. + http://<hostname>/tor/status-vote/current/bandwidth.z + once the voting period ends, regardless of the number of signatures. The authorities serve another consensus of each flavor "F" from the locations /tor/status-vote/(current|next)/consensus-F.z. and /tor/status-vote/(current|next)/consensus-F/<FP1>+....z. + The standard URLs for bandwidth list files first-appeared in Tor 0.3.5. 4. Directory cache operation diff --git a/proposals/xxx-expose-bwauth_votes.txt b/proposals/xxx-expose-bandwidth-files.txt similarity index 64% rename from proposals/xxx-expose-bwauth_votes.txt rename to proposals/xxx-expose-bandwidth-files.txt index 93a6f1a..12abe0e 100644 --- a/proposals/xxx-expose-bwauth_votes.txt +++ b/proposals/xxx-expose-bandwidth-files.txt @@ -1,5 +1,5 @@ -Filename: xxx-expose-bwauth_votes.txt -Title: Have Directory Authorities expose raw bandwidth list file documents +Filename: xxx-expose-bandwidth-files.txt +Title: Have Directory Authorities expose raw bandwidth list files Author: Tom Ritter Created: 11-December-2017 Status: Open @@ -8,10 +8,10 @@ Ticket: https://trac.torproject.org/projects/tor/ticket/21377 1. Introduction Bandwidth Authorities (bwauths) perform scanning of the Tor Network -and calculate observed speeds for each relay. They produce a bandwidth +and calculate observed bandwidths for each relay. They produce a bandwidth list file that is given to a Directory Authority. The Directory -Authority uses the speed value from this file in its vote file -denoting its view of the speed of the relay. +Authority uses the bw (bandwidth) value from this file in its vote file +denoting its view of the bandwidth of the relay. After collecting all of the votes from other Authorities, a consensus is calculated, and the consensus's view of a relay's speed is @@ -23,16 +23,21 @@ Directory Authority's vote, however the original file contains considerably more diagnostic information about how the bwauth arrives at that measurement for that relay. +For more details, see the bandwidth list file specification in +bandwidth-file-spec.txt. + 2. Motivation The bandwidth list file contains more information than is exposed in the -overall vote file. This information is useful to debug anomalies in -relays' utilization and suspected bugs in the (decrepit) bwauth code. +overall vote file. This information is useful to debug: + * anomalies in relays' utilization, + * suspected bugs in the (decrepit) bwauth code, and + * the transition to a replacement bwauth implementation. Currently, all bwauths expose the bandwidth list file through various (non- standard) means, and that file is downloaded (hourly) by a single person (as long as his home internet connection and home server is working) -and archived (with a small amount of robustness.) +and archived (with a small amount of robustness.) It would be preferable to have this exposed in a standard manner. Doing so would no longer require bwauths to run HTTP servers to expose @@ -43,19 +48,25 @@ parties. We hope that Collector will begin archiving the files. 3. Specification An authority SHOULD publish the bandwidth list file used to calculate its -current vote. It SHOULD make the bandwidth list file available at all -times, and provide the file that it has most recently used for its -vote (even if the vote is not currently published.) It SHOULD make -the file available at +next vote. It SHOULD make the bandwidth list file available whenever the +corresponding vote is available, at the corresponding URL. (See +dir-spec for the exact details.) + +It SHOULD make the file available at http://<hostname>/tor/status-vote/next/bandwidth.z + http://<hostname>/tor/status-vote/current/bandwidth.z It MUST NOT attempt to send its bandwidth list file in a HTTP POST to other authorities and it SHOULD NOT make bandwidth list files from other authorities available. -Clients interested in consuming the document should download it when -votes are created. (For the existing Tor network, this is at HH:50, -or 50 minutes after each hour.) +Clients interested in consuming these documents should download them from +each authority's: + * next URL when votes are created. (In the public Tor network, this is + after HH:50 during normal operation, and after HH:20 during a + consensus failure.) + * current URL after the valid-after time in the consensus. + (After HH:00, and HH:30 during consensus failure.) 4. Security Implications