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 894ff2dc 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>

"ours" to avoid version bump.

"ours" to avoid version bump.

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.

We're going to disable this feature in all versions for now.

"ours" to avoid version bump.

"ours" to avoid version bump.

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>

See comments about why this needs a new flag and we can't just use
CIRCUIT_PURPOSE_CONTROLLER.

Fixes #40285; bugfix on 0.3.2.1-alpha.

Fixes bug #40256; bugfix on 0.2.9.4-alpha.

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.