[tor-commits] [torspec/master] fixup name the right function in 210

[nickm at torproject.org]

commit 5149a07d896e212655992468dbb1edc980c9d0d2
Author: teor (Tim Wilson-Brown) <teor2345 at gmail.com>
Date:   Sat Oct 3 22:44:35 2015 +0200

    fixup name the right function in 210
---
 .../210-faster-headless-consensus-bootstrap.txt    |   27 ++++++++++++--------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/proposals/210-faster-headless-consensus-bootstrap.txt b/proposals/210-faster-headless-consensus-bootstrap.txt
index d527c2c..8e3cc69 100644
--- a/proposals/210-faster-headless-consensus-bootstrap.txt
+++ b/proposals/210-faster-headless-consensus-bootstrap.txt
@@ -154,23 +154,30 @@ Implementation Notes: Code Modifications
  if the purpose is DIR_PURPOSE_FETCH_CONSENSUS and there is no valid
  (reasonably live) consensus. We can make multiple connections from
  update_consensus_networkstatus_downloads(), as the sockets are non-blocking.
- [ XXX - is this true for all platforms? ]
+ [ XXX - is this socket actually non-blocking for all platforms? ]
  As long as we can tolerate a timer resolution of ~1 second (due to the use
  of time_t), this requires no additional timers or callbacks. We can make 1
- connection for each schedule per second, for a total of 2 per second, or 4
- per second if the IPv4 and IPv6 schedules are implemented separately.
+ connection for each schedule per second, for a total of 2 per second.
 
  update_consensus_networkstatus_downloads() would also check the list of
  pending connections and, if it is 10 or greater, skip the connection
  attempt, and leave the retry time constant.
 
- The code in directory_initiate_command_rend() or
- connection_dir_finished_connecting() would need to be altered to check that
- we are not already downloading the consensus. If we’re not, then call
- directory_send_command() to download the consensus, and close any other
- pending consensus dircons. (We may still want to check our clock against an
- authority by allowing a TLS connection to complete, then immediately closing
- it.)
+ The code in connection_dir_finished_connecting() would need to be altered to
+ check that we are not already downloading the consensus. If we’re not, then
+ call directory_send_command() to download the consensus, and close any other
+ pending consensus dircons. Since we want to check our clock against an
+ authority at least once per run, we instead mark authority connections so
+ they only request a HTTP HEAD, and use the first date header we see to
+ detect if the client’s clock is skewed.
+ [ XXX - does Tor support HTTP HEAD? ]
+
+ We might also need to make similar changes in authority_certs_fetch_missing(),
+ as we can’t use a consensus until we have enough authority certificates.
+ However, Tor already makes multiple requests (one per certificate), and only
+ needs a majority of certificates to validate a consensus. Therefore, we will
+ only need to modify authority_certs_fetch_missing() if clients download a
+ consensus, then end up getting stuck downloading certificates.
 
 Reliability Analysis