When seccomp sandbox is active, SAVECONF failed because it was not
able to save the backup files for torrc. This commit simplifies
the implementation of SAVECONF and sandbox by making it keep only
one backup of the configuration file.
In versions <=2.69, according to the autoconf docs, AC_PROG_CC_C99
is needed with some compilers, if they require extra arguments to
build C99 programs. In versions >=2.70, AC_PROG_CC checks for these
compilers automatically, and so the AC_PROG_CC_C99 macro is
obsolete.
So, what can you do if you want your script to work right with both
autoconf versions? IIUC, neither including AC_PROG_CC_C99 macro nor
leaving it out will give you the right behavior with both versions.
It looks like you need to look at the autoconf version explicitly.
(Now, the autoconf manual implies that it's "against autoconf
philosophy" to look at the autoconf version rather than trying the
behavior to see if it works, but they don't actually tell you how to
detect recoverably at autoconf-time whether a macro is obsolete or
not, and I can't find a way to do that.)
So, is it safe to use m4_version_prereq, like I do here? It isn't
listed in the autoconf 2.63 manual (which is the oldest version we
support). But a mailing list message [1] (which added the
documentation back in 2008) implies that m4_version_prereq has been
there since "at least back to autoconf 2.59".
https://lists.gnu.org/archive/html/autoconf-patches/2008-12/msg00025.html
So I think this will work.
I am basing this patch against Tor 0.3.5 since, if autoconf 2.70
becomes widespread before 0.3.5 is unsupported, we might need this
patch to continue 0.3.5 development. But I don't think we should
backport farther than 0.4.5 until/unless that actually happens.
This is part of a fix for #40355.
On Linux systems, glob automatically ignores the errors ENOENT and
ENOTDIR because they are expected during glob expansion. But BSD
systems do not ignore these, resulting in glob failing when globs
expand to invalid paths. This is fixed by adding a custom error
handler that ignores only these two errors and removing the
GLOB_ERR flag as it makes glob fail even if the error handler
ignores the error and is unnecessary as the error handler will
make glob fail on all other errors anyway.
Fortunately, our tor_free() is setting the variable to NULL after so we were
in a situation where NULL was always used instead of the transport name.
This first appeared in 894ff2dc84 and results in
basically no bridge with a transport being able to use DoS defenses.
Fixes#40345
Signed-off-by: David Goulet <dgoulet@torproject.org>
Clients now check whether their streams are attempting to re-enter
the Tor network (i.e. to send Tor traffic over Tor), and they close
them preemptively if they think exit relays will refuse them.
See bug 2667 for details. Resolves ticket 40271.
- Implement overload statistics structure.
- Implement function that keeps track of overload statistics.
- Implement function that writes overload statistics to descriptor.
- Unittest for the whole logic.
We were looking for the first instance of "directory-signature "
when instead the correct behavior is to look for the first instance
of "directory-signature " at the start of a line.
Unfortunately, this can be exploited as to crash authorities while
they're voting.
Fixes#40316; bugfix on 0.2.2.4-alpha. This is TROVE-2021-002,
also tracked as CVE-2021-28090.
When reloading a service, we can re-register a service and thus end up again
in the metrics store initialization code path which is fine. No need to BUG()
anymore.
Fixes#40334
Signed-off-by: David Goulet <dgoulet@torproject.org>
Use find_str_at_start_of_line(), not strstr() here: we don't want
to match "MemTotal: " if it appears in the middle of a line.
Fixes#40315; bugfix on 0.2.5.4-alpha.
The directory_fetches_from_authorities() is used to know if a client or relay
should fetch data from an authority early in the boot process.
We had a condition in that function that made a relay trigger that fetch if it
didn't know its address (so we can learn it). However, when this is called,
the address discovery has not been done yet so it would always return true for
a relay.
Furthermore, it would always trigger a log notice that the IPv4 couldn't be
found which was inevitable because the address discovery process has not been
done yet (done when building our first descriptor).
It is also important to point out that starting in 0.4.5.1-alpha, asking an
authority for an address is done during address discovery time using a one-hop
circuit thus independent from the relay deciding to fetch or not documents
from an authority.
Small fix also is to reverse the "IPv(4|6)Only" flag in the notice so that if
we can't find IPv6 it would output to use IPv4Only.
Fixes#40300
Signed-off-by: David Goulet <dgoulet@torproject.org>
Fix a bug introduced in 94b56eaa75 which
overwrite the connection message line.
Furthermore, improve how we generate that line by using a smartlist and change
the format so it is clearer of what is being rejected/detected and, if
applicable, which option is disabled thus yielding no stats.
Closes#40308
Signed-off-by: David Goulet <dgoulet@torproject.org>
This is a new detection type which is that a relay can now control the rate of
client connections from a single address.
The mechanism is pretty simple, if the rate/burst is reached, the address is
marked for a period of time and any connection from that address is denied.
Closes#40253
Signed-off-by: David Goulet <dgoulet@torproject.org>
When trying to find our address to publish, we would log notice if we couldn't
find it from the cache but then we would look at the suggested cache (which
contains the address from the authorities) in which we might actually have the
address.
Thus that log notice was misplaced. Move it down after the suggested address
cache lookup.
Closes#40300
Signed-off-by: David Goulet <dgoulet@torproject.org>
It can be called with strings that should have been
length-delimited, but which in fact are not. This can cause a
CPU-DoS bug or, in a worse case, a crash.
Since this function isn't essential, the best solution for older
Tors is to just turn it off.
Fixes bug 40286; bugfix on 0.2.2.1-alpha when dump_desc() was
introduced.
Now that exit relays don't allow exit connections to directory authority
DirPorts, the follow-up step is to make directory authorities stop doing
DirPort reachability checks.
Fixes#40287
Signed-off-by: David Goulet <dgoulet@torproject.org>
Turns out, we forgot to add the METRICS connection type fo the finished
flushing handler.
Fixes#40295
Signed-off-by: David Goulet <dgoulet@torproject.org>
We were just looking at the family which is not correct because it is possible
to have two explicit ORPort for the same family but different addresses. One
example is:
ORPort 127.0.0.1:9001 NoAdvertise
ORPort 1.2.3.4:9001 NoListen
Thus, this patch now ignores ports that have different addresses iff they are
both explicits. That is, if we have this example, also two different
addresses:
ORPort 9001
ORPort 127.0.0.1:9001 NoAdvertise
The first one is implicit and second one is explicit and thus we have to
consider them for removal which in this case would remove the "ORPort 9001" in
favor of the second port.
Fixes#40289
Signe-off-by: David Goulet <dgoulet@torproject.org>
In other words, if PublishServerDescriptor is set to 0 and AssumeReachable to
1, then allow a relay to hold a RFC1918 address.
Reasons for this are documented in #40208Fixes#40208
Signed-off-by: David Goulet <dgoulet@torproject.org>
Handle the EOF situation for a metrics connection. Furthermore, if we failed
to fetch the data from the inbuf properly, mark the socket as closed because
the caller, connection_process_inbuf(), assumes that we did so on error.
Fixes#40257
Signed-off-by: David Goulet <dgoulet@torproject.org>
Previously we would warn in this case... but there's really no
justification for doing so, and it can only cause confusion.
Fixes bug #40281; bugfix on 0.4.0.1-alpha.
In two instances we must look at this flag:
1. When we build the descriptor so the IPv6 is NOT added to the descriptor in
case we judge that we need to omit the address but still publish.
2. When we are deciding if the descriptor is publishable. This flags tells us
that the IPv6 was not found reachable but we should still publish.
Fixes#40279
Signed-off-by: David Goulet <dgoulet@torproject.org>
Exit relays now reject exit attempts to known relay addresses + ORPort and
also to authorities on the ORPort and DirPort.
Closes#2667
Signed-off-by: David Goulet <dgoulet@torproject.org>
Exit relays now reject exit attempts to known relay addresses + ORPort and
also to authorities on the ORPort and DirPort.
Closes#2667
Signed-off-by: David Goulet <dgoulet@torproject.org>
