One pain point in evolving the Tor design and implementing has been
adding code that makes clients reject directory documents that they
previously would have accepted, if those descriptors actually exist.
When this happened, the clients would get the document, reject it,
and then decide to try downloading it again, ad infinitum. This
problem becomes particularly obnoxious with authorities, since if
some authorities accept a descriptor that others don't, the ones
that don't accept it would go crazy trying to re-fetch it over and
over. (See for example ticket #9286.)
This patch tries to solve this problem by tracking, if a descriptor
isn't parseable, what its digest was, and whether it is invalid
because of some flaw that applies to the portion containing the
digest. (This excludes RSA signature problems: RSA signatures
aren't included in the digest. This means that a directory
authority can still put another directory authority into a loop by
mentioning a descriptor, and then serving that descriptor with an
invalid RSA signatures. But that would also make the misbehaving
directory authority get DoSed by the server it's attacking, so it's
not much of an issue.)
We already have a mechanism to mark something undownloadable with
downloadstatus_mark_impossible(); we use that here for
microdescriptors, extrainfos, and router descriptors.
Unit tests to follow in another patch.
Closes ticket #11243.
The remaining vestige is that we continue to publish the V2dir flag,
and that, for the controller, we continue to emit v2 directory
formats when requested.
The 'body' field of a microdesc_t holds a strdup()'d value if the
microdesc's saved_location field is SAVED_IN_JOURNAL or
SAVED_NOWHERE, and holds a pointer to the middle of an mmap if the
microdesc is SAVED_IN_CACHE. But we weren't setting that field
until a while after we parsed the microdescriptor, which left an
interval where microdesc_free() would try to free() the middle of
the mmap().
This patch also includes a regression test.
This is a fix for #10409; bugfix on 0.2.2.6-alpha.
Now we can compute the hash and signature of a dirobj before
concatenating the smartlist, and we don't need to play silly games
with sigbuf and realloc any more.
This was causing dirauths to emit flag weight validation warns if there
was a sufficiently large amount of badexit bandwidth to make a difference in
flag weight results.
This patch moves the measured_bw field and the has_measured_bw field
into vote_routerstatus_t, since only votes have 'Measured=XX' set on
their weight line.
I also added a new bw_is_unmeasured flag to routerstatus_t to
represent the Unmeasured=1 flag on a w line. Previously, I was using
has_measured_bw for this, which was quite incorrect: has_measured_bw
means that the measured_bw field is set, and it's probably a mistake
to have it serve double duty as meaning that 'baandwidth' represents a
measured value.
While making this change,I also found a harmless but stupid bug in
dirserv_read_measured_bandwidths: It assumes that it's getting a
smartlist of routerstatus_t, when really it's getting a smartlist of
vote_routerstatus_t. C's struct layout rules mean that we could never
actually get an error because of that, but it's still quite incorrect.
I fixed that, and in the process needed to add two more sorting and
searching helpers.
Finally, I made the Unmeasured=1 flag get parsed. We don't use it for
anything yet, but someday we might.
This isn't complete yet -- the new 2286 unit test doesn't build.
In C, we technically aren't supposed to define our own things that
start with an underscore.
This is a purely machine-generated commit. First, I ran this script
on all the headers in src/{common,or,test,tools/*}/*.h :
==============================
use strict;
my %macros = ();
my %skipped = ();
FILE: for my $fn (@ARGV) {
my $f = $fn;
if ($fn !~ /^\.\//) {
$f = "./$fn";
}
$skipped{$fn} = 0;
open(F, $fn);
while (<F>) {
if (/^#ifndef ([A-Za-z0-9_]+)/) {
$macros{$fn} = $1;
next FILE;
}
}
}
print "#!/usr/bin/perl -w -i -p\n\n";
for my $fn (@ARGV) {
if (! exists $macros{$fn}) {
print "# No macro known for $fn!\n" if (!$skipped{$fn});
next;
}
if ($macros{$fn} !~ /_H_?$/) {
print "# Weird macro for $fn...\n";
}
my $goodmacro = uc $fn;
$goodmacro =~ s#.*/##;
$goodmacro =~ s#[\/\-\.]#_#g;
print "s/(?<![A-Za-z0-9_])$macros{$fn}(?![A-Za-z0-9_])/TOR_${goodmacro}/g;\n"
}
==============================
It produced the following output, which I then re-ran on those same files:
==============================
s/(?<![A-Za-z0-9_])_TOR_ADDRESS_H(?![A-Za-z0-9_])/TOR_ADDRESS_H/g;
s/(?<![A-Za-z0-9_])_TOR_AES_H(?![A-Za-z0-9_])/TOR_AES_H/g;
s/(?<![A-Za-z0-9_])_TOR_COMPAT_H(?![A-Za-z0-9_])/TOR_COMPAT_H/g;
s/(?<![A-Za-z0-9_])_TOR_COMPAT_LIBEVENT_H(?![A-Za-z0-9_])/TOR_COMPAT_LIBEVENT_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONTAINER_H(?![A-Za-z0-9_])/TOR_CONTAINER_H/g;
s/(?<![A-Za-z0-9_])_TOR_CRYPTO_H(?![A-Za-z0-9_])/TOR_CRYPTO_H/g;
s/(?<![A-Za-z0-9_])TOR_DI_OPS_H(?![A-Za-z0-9_])/TOR_DI_OPS_H/g;
s/(?<![A-Za-z0-9_])_TOR_MEMAREA_H(?![A-Za-z0-9_])/TOR_MEMAREA_H/g;
s/(?<![A-Za-z0-9_])_TOR_MEMPOOL_H(?![A-Za-z0-9_])/TOR_MEMPOOL_H/g;
s/(?<![A-Za-z0-9_])TOR_PROCMON_H(?![A-Za-z0-9_])/TOR_PROCMON_H/g;
s/(?<![A-Za-z0-9_])_TOR_TORGZIP_H(?![A-Za-z0-9_])/TOR_TORGZIP_H/g;
s/(?<![A-Za-z0-9_])_TOR_TORINT_H(?![A-Za-z0-9_])/TOR_TORINT_H/g;
s/(?<![A-Za-z0-9_])_TOR_LOG_H(?![A-Za-z0-9_])/TOR_TORLOG_H/g;
s/(?<![A-Za-z0-9_])_TOR_TORTLS_H(?![A-Za-z0-9_])/TOR_TORTLS_H/g;
s/(?<![A-Za-z0-9_])_TOR_UTIL_H(?![A-Za-z0-9_])/TOR_UTIL_H/g;
s/(?<![A-Za-z0-9_])_TOR_BUFFERS_H(?![A-Za-z0-9_])/TOR_BUFFERS_H/g;
s/(?<![A-Za-z0-9_])_TOR_CHANNEL_H(?![A-Za-z0-9_])/TOR_CHANNEL_H/g;
s/(?<![A-Za-z0-9_])_TOR_CHANNEL_TLS_H(?![A-Za-z0-9_])/TOR_CHANNELTLS_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITBUILD_H(?![A-Za-z0-9_])/TOR_CIRCUITBUILD_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITLIST_H(?![A-Za-z0-9_])/TOR_CIRCUITLIST_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITMUX_EWMA_H(?![A-Za-z0-9_])/TOR_CIRCUITMUX_EWMA_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITMUX_H(?![A-Za-z0-9_])/TOR_CIRCUITMUX_H/g;
s/(?<![A-Za-z0-9_])_TOR_CIRCUITUSE_H(?![A-Za-z0-9_])/TOR_CIRCUITUSE_H/g;
s/(?<![A-Za-z0-9_])_TOR_COMMAND_H(?![A-Za-z0-9_])/TOR_COMMAND_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONFIG_H(?![A-Za-z0-9_])/TOR_CONFIG_H/g;
s/(?<![A-Za-z0-9_])TOR_CONFPARSE_H(?![A-Za-z0-9_])/TOR_CONFPARSE_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONNECTION_EDGE_H(?![A-Za-z0-9_])/TOR_CONNECTION_EDGE_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONNECTION_H(?![A-Za-z0-9_])/TOR_CONNECTION_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONNECTION_OR_H(?![A-Za-z0-9_])/TOR_CONNECTION_OR_H/g;
s/(?<![A-Za-z0-9_])_TOR_CONTROL_H(?![A-Za-z0-9_])/TOR_CONTROL_H/g;
s/(?<![A-Za-z0-9_])_TOR_CPUWORKER_H(?![A-Za-z0-9_])/TOR_CPUWORKER_H/g;
s/(?<![A-Za-z0-9_])_TOR_DIRECTORY_H(?![A-Za-z0-9_])/TOR_DIRECTORY_H/g;
s/(?<![A-Za-z0-9_])_TOR_DIRSERV_H(?![A-Za-z0-9_])/TOR_DIRSERV_H/g;
s/(?<![A-Za-z0-9_])_TOR_DIRVOTE_H(?![A-Za-z0-9_])/TOR_DIRVOTE_H/g;
s/(?<![A-Za-z0-9_])_TOR_DNS_H(?![A-Za-z0-9_])/TOR_DNS_H/g;
s/(?<![A-Za-z0-9_])_TOR_DNSSERV_H(?![A-Za-z0-9_])/TOR_DNSSERV_H/g;
s/(?<![A-Za-z0-9_])TOR_EVENTDNS_TOR_H(?![A-Za-z0-9_])/TOR_EVENTDNS_TOR_H/g;
s/(?<![A-Za-z0-9_])_TOR_GEOIP_H(?![A-Za-z0-9_])/TOR_GEOIP_H/g;
s/(?<![A-Za-z0-9_])_TOR_HIBERNATE_H(?![A-Za-z0-9_])/TOR_HIBERNATE_H/g;
s/(?<![A-Za-z0-9_])_TOR_MAIN_H(?![A-Za-z0-9_])/TOR_MAIN_H/g;
s/(?<![A-Za-z0-9_])_TOR_MICRODESC_H(?![A-Za-z0-9_])/TOR_MICRODESC_H/g;
s/(?<![A-Za-z0-9_])_TOR_NETWORKSTATUS_H(?![A-Za-z0-9_])/TOR_NETWORKSTATUS_H/g;
s/(?<![A-Za-z0-9_])_TOR_NODELIST_H(?![A-Za-z0-9_])/TOR_NODELIST_H/g;
s/(?<![A-Za-z0-9_])_TOR_NTMAIN_H(?![A-Za-z0-9_])/TOR_NTMAIN_H/g;
s/(?<![A-Za-z0-9_])_TOR_ONION_H(?![A-Za-z0-9_])/TOR_ONION_H/g;
s/(?<![A-Za-z0-9_])_TOR_OR_H(?![A-Za-z0-9_])/TOR_OR_H/g;
s/(?<![A-Za-z0-9_])_TOR_POLICIES_H(?![A-Za-z0-9_])/TOR_POLICIES_H/g;
s/(?<![A-Za-z0-9_])_TOR_REASONS_H(?![A-Za-z0-9_])/TOR_REASONS_H/g;
s/(?<![A-Za-z0-9_])_TOR_RELAY_H(?![A-Za-z0-9_])/TOR_RELAY_H/g;
s/(?<![A-Za-z0-9_])_TOR_RENDCLIENT_H(?![A-Za-z0-9_])/TOR_RENDCLIENT_H/g;
s/(?<![A-Za-z0-9_])_TOR_RENDCOMMON_H(?![A-Za-z0-9_])/TOR_RENDCOMMON_H/g;
s/(?<![A-Za-z0-9_])_TOR_RENDMID_H(?![A-Za-z0-9_])/TOR_RENDMID_H/g;
s/(?<![A-Za-z0-9_])_TOR_RENDSERVICE_H(?![A-Za-z0-9_])/TOR_RENDSERVICE_H/g;
s/(?<![A-Za-z0-9_])_TOR_REPHIST_H(?![A-Za-z0-9_])/TOR_REPHIST_H/g;
s/(?<![A-Za-z0-9_])_TOR_REPLAYCACHE_H(?![A-Za-z0-9_])/TOR_REPLAYCACHE_H/g;
s/(?<![A-Za-z0-9_])_TOR_ROUTER_H(?![A-Za-z0-9_])/TOR_ROUTER_H/g;
s/(?<![A-Za-z0-9_])_TOR_ROUTERLIST_H(?![A-Za-z0-9_])/TOR_ROUTERLIST_H/g;
s/(?<![A-Za-z0-9_])_TOR_ROUTERPARSE_H(?![A-Za-z0-9_])/TOR_ROUTERPARSE_H/g;
s/(?<![A-Za-z0-9_])TOR_ROUTERSET_H(?![A-Za-z0-9_])/TOR_ROUTERSET_H/g;
s/(?<![A-Za-z0-9_])TOR_STATEFILE_H(?![A-Za-z0-9_])/TOR_STATEFILE_H/g;
s/(?<![A-Za-z0-9_])_TOR_STATUS_H(?![A-Za-z0-9_])/TOR_STATUS_H/g;
s/(?<![A-Za-z0-9_])TOR_TRANSPORTS_H(?![A-Za-z0-9_])/TOR_TRANSPORTS_H/g;
s/(?<![A-Za-z0-9_])_TOR_TEST_H(?![A-Za-z0-9_])/TOR_TEST_H/g;
s/(?<![A-Za-z0-9_])_TOR_FW_HELPER_H(?![A-Za-z0-9_])/TOR_TOR_FW_HELPER_H/g;
s/(?<![A-Za-z0-9_])_TOR_FW_HELPER_NATPMP_H(?![A-Za-z0-9_])/TOR_TOR_FW_HELPER_NATPMP_H/g;
s/(?<![A-Za-z0-9_])_TOR_FW_HELPER_UPNP_H(?![A-Za-z0-9_])/TOR_TOR_FW_HELPER_UPNP_H/g;
==============================
We were doing an O(n) strlen in router_get_extrainfo_hash() for
every one we tried to parse. Instead, have
router_get_extrainfo_hash() take the length of the extrainfo as an
argument, so that when it's called from
extrainfo_parse_from_string(), it doesn't do a strlen() over the
whole pile of extrainfos.
Previously the client would ask the bridge for microdescriptors, which are
only supported in 0.2.3.x and later, and then fail to bootstrap when it
didn't get the answers it wanted. Fixes bug 4013; bugfix on 0.2.3.2-alpha.
The fix here is to revert to using normal descriptors if any of our
bridges are known to not support microdescs. This is not ideal, a) because
we'll start downloading a microdesc consensus as soon as we get a bridge
descriptor, and that will waste time if we later get a bridge descriptor
that tells us we don't like microdescriptors; and b) by changing our mind
we're leaking to our other bridges that we have an old-version bridge.
The alternate fix would have been to change
we_use_microdescriptors_for_circuits() to ask if *any* of our bridges
can support microdescriptors, and then change the directory logic that
picks a bridge to only select from those that do. For people living in
the future, where 0.2.2.x is obsolete, there won't be a difference.
Note that in either of these potential fixes, we have risk of oscillation
if our one funny-looking bridges goes away / comes back.
