This time, I follow grarpamp's suggestion and move the check for
.exit+AllowDotExit 0 to the top of connection_ap_rewrite_and_attach,
before any rewriting occurs. This way, .exit addresses are
forbidden as they arrive from a socks connection or a DNSPort
request, and not otherwise.
It _is_ a little more complicated than that, though. We need to
treat any .exit addresses whose source is TrackHostExits as meaning
that we can retry without that exit. We also need to treat any
.exit address that comes from an AutomapHostsOnResolve operation as
user-provided (and thus forbidden if AllowDotExits==0), so that
transitioning from AllowDotExits==1 to AllowDotExits==0 will
actually turn off automapped .exit addresses.
This fixes a side-channel attack on the (fortunately unused!)
BridgePassword option for bridge authorities. Fix for bug 5543;
bugfix on 0.2.0.14-alpha.
This is ticket 2479. Roger's original explanation was:
We have a series of bugs where relays publish a descriptor within
12 hours of their last descriptor, but the authorities drop it
because it's not different "enough" from the last one and it's
too close to the last one.
The original goal of this idea was to a) reduce the number of new
descriptors authorities accept (and thus have to store) and b)
reduce the total number of descriptors that clients and mirrors
fetch. It's a defense against bugs where relays publish a new
descriptor every minute.
Now that we're putting out one consensus per hour, we're doing
better at the total damage that can be caused by 'b'.
There are broader-scale design changes that would help here, and
we've had a trac entry open for years about how relays should
recognize that they're not in the consensus, or recognize when
their publish failed, and republish sooner.
In the mean time, I think we should change some of the parameters
to make the problem less painful.
This commit is completely mechanical; I used this perl script to make it:
#!/usr/bin/perl -w -i.bak -p
if (/^\s*\#/) {
s/MS_WINDOWS/_WIN32/g;
s/\bWIN32\b/_WIN32/g;
}
The Tor2webMode torrc option is still required to run a Tor client in
'tor2web mode', but now it can't be turned on at runtime in a normal build
of Tor. (And a tor2web build of Tor can't be used as a normal Tor client,
so we don't have to worry as much about someone distributing packages with
this particular pistol accessible to normal users.)
Comments below focus on changes, see diff for added code.
New type tor_addr_port_t holding an IP address and a TCP/UDP port.
New flag in routerinfo_t, ipv6_preferred. This should go in the
node_t instead but not now.
Replace node_get_addr() with
- node_get_prim_addr() for primary address, i.e. IPv4 for now
- node_get_pref_addr() for preferred address, IPv4 or IPv6.
Rename node_get_addr_ipv4h() node_get_prim_addr_ipv4h() for
consistency. The primary address will not allways be an IPv4 address.
Same for node_get_orport() -> node_get_prim_orport().
Rewrite node_is_a_configured_bridge() to take all OR ports into account.
Extend argument list to extend_info_from_node and
extend_info_from_router with a flag indicating if we want to use the
routers primary address or the preferred address. Use the preferred
address in as few situtations as possible for allowing clients to
connect to bridges over IPv6.
This code handles the new ORPort options, and incidentally makes all
remaining port types use the new port configuration systems.
There are some rough edges! It doesn't do well in the case where your
Address says one thing but you say to Advertise another ORPort. It
doesn't handle AllAddrs. It doesn't actually advertise anything besides
the first listed advertised IPv4 ORPort and DirPort. It doesn't do
port forwarding to them either.
It's not tested either, it needs more documentation, and it probably
forgets to put the milk back in the refrigerator.
Some controllers want this so they can mess with Tor's configuration
for a while via the control port before actually letting Tor out of
the house.
We do this with a new DisableNetwork option, that prevents Tor from
making any outbound connections or binding any non-control
listeners. Additionally, it shuts down the same functionality as
shuts down when we are hibernating, plus the code that launches
directory downloads.
To make sure I didn't miss anything, I added a clause straight to
connection_connect, so that we won't even try to open an outbound
socket when the network is disabled. In my testing, I made this an
assert, but since I probably missed something, I've turned it into a
BUG warning for testing.
This starts an effort to refactor torrc handling code to make it easier
to live with. It makes it possible to override exit policies from the
command line, and possible to override (rather than append to) socksport
lists from the command line.
It'll be necessary to make a "base" torrc implementation work at all.
