Merge branch 'maint-0.3.2' into release-0.3.2

This commit is contained in:
Nick Mathewson 2017-11-05 14:41:53 -05:00
commit 6bc1632b72
3 changed files with 31 additions and 5 deletions

9
changes/bug21394 Normal file
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@ -0,0 +1,9 @@
o Major bugfixes (Exit nodes):
- Fix an issue causing high-bandwidth exit nodes to fail a majority
or all of their DNS requests, making them basically unsuitable for
regular usage in Tor circuits. The problem is related to
libevent's DNS handling, but we can work around it in Tor. Fixes
bugs 21394 and 18580; bugfix on 0.1.2.2-alpha which introduced
eventdns. Credit goes to Dhalgren for identifying and finding a
workaround to this bug and to gamambel, arthuredelstein and
arma in helping to track it down and analyze it.

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@ -76,13 +76,13 @@ def lintfile(fname):
if isBug and not re.search(r'(\d+)', contents):
warn("Ticket marked as bugfix, but does not mention a number.")
elif isBug and not re.search(r'Fixes ([a-z ]*)bug (\d+)', contents):
elif isBug and not re.search(r'Fixes ([a-z ]*)bugs? (\d+)', contents):
warn("Ticket marked as bugfix, but does not say 'Fixes bug XXX'")
if re.search(r'[bB]ug (\d+)', contents):
if not re.search(r'[Bb]ugfix on ', contents):
warn("Bugfix does not say 'bugfix on X.Y.Z'")
elif not re.search('[fF]ixes ([a-z ]*)bug (\d+); bugfix on ',
elif not re.search('[fF]ixes ([a-z ]*)bugs? (\d+)((, \d+)* and \d+)?; bugfix on ',
contents):
warn("Bugfix does not say 'Fixes bug X; bugfix on Y'")
elif re.search('tor-([0-9]+)', contents):

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@ -1438,14 +1438,31 @@ configure_nameservers(int force)
#define SET(k,v) evdns_base_set_option(the_evdns_base, (k), (v))
// If we only have one nameserver, it does not make sense to back off
// from it for a timeout. Unfortunately, the value for max-timeouts is
// currently clamped by libevent to 255, but it does not hurt to set
// it higher in case libevent gets a patch for this.
// Reducing attempts in the case of just one name server too, because
// it is very likely to be a local one where a network connectivity
// issue should not cause an attempt to fail.
if (evdns_base_count_nameservers(the_evdns_base) == 1) {
SET("max-timeouts:", "16");
SET("timeout:", "10");
SET("max-timeouts:", "1000000");
SET("attempts:", "1");
} else {
SET("max-timeouts:", "3");
SET("timeout:", "5");
}
// Elongate the queue of maximum inflight dns requests, so if a bunch
// time out at the resolver (happens commonly with unbound) we won't
// stall every other DNS request. This potentially means some wasted
// CPU as there's a walk over a linear queue involved, but this is a
// much better tradeoff compared to just failing DNS requests because
// of a full queue.
SET("max-inflight:", "8192");
// Time out after 5 seconds if no reply.
SET("timeout:", "5");
if (options->ServerDNSRandomizeCase)
SET("randomize-case:", "1");
else