This C file will eventually belong in lib/confmgt, so it needs to
have only low-level dependencies. Now that it no longers needs
routerset.c, we can adjust its includes accordingly.
I'm not moving the file yet, since it would make fixup commits on
earlier branches here really hard to do.
Now that we have a reasonable implementation for overriding the
default options for TestingTorNetwork, we don't need to modify
config_var_t structs any more. And therefore, we can have constant
format options, like reasonable people.
It's important to make sure that we don't change a config_mgr_t
after we start using it to make objects, or we could get into
inconsistent states. This feature is the start of a safety
mechanism to prevent this problem.
Previously, when TestingTorNetwork was set, we would manually adjust
the initvalue members of a bunch of other config_var_t, and then
re-run the early parts or parsing the options.
Now we treat the initvalue fields as immutable, but instead assign
to them in options_init(), as early as possible. Rather than
re-running the early parts of options, we just re-call the
options_init_from_string() function.
This patch de-kludges some of our code pretty handily. I think it
could later handle authorities and fallbacks, but for now I think we
should leave those alone.
Iterating over this array was once a good idea, but now that we are
going to have a separate structure for each submodule's
configuration variables, we should indirect through the config_mgr_t
object.
The eventual design here will be that multiple config_format_t
objects get registered with a single config_mgr_t. That
config_mgr_t manages a "top-level" object, which has a pointer to
the other objects.
I had earlier thought of a different design, where there would be no
top-level object, and config_mgr_t would deal with a container
instead. But this would require a bunch of invasive refactoring
that I don't think we should do just yet.
Remember that our goal in the present refactoring is to allow each
subsystem to declare its own configuration structure and
variables. To do this, each module will get its own
config_format_t, and so we'll want a different structure that wraps
several config_format_t objects. This is a "config_mgr_t".
This shouldn't be possible while Tor is running, but the tests can
hit this code. Rather than force the tests to add a dummy channel
object, let's just tolerate their incompletely built circuits.
Make origin-side messages about padding negotiation failure into
LOG_PROTOCOL_WARN.
I'm not sure I like this either.. But the negotiation refusal case might
happen naturally due to consensus drift, and is functionally no different than
a corrupted cell.
There is other code that uses this value, and some of it is
apparently reachable from inside router_dir_info_changed(), which
routerlist_free() apparently calls. (ouch!) This is a minimal fix
to try to resolve the issue without causing other problems.
Fixes bug 31003. I'm calling this a bugfix on 0.1.2.2-alpha, where
the call to router_dir_info_changed() was added to routerlist_free().
Overflowing a signed integer in C is an undefined behaviour.
It is possible to trigger this undefined behaviour in tor_asprintf on
Windows or systems lacking vasprintf.
On these systems, eiter _vscprintf or vsnprintf is called to retrieve
the required amount of bytes to hold the string. These functions can
return INT_MAX. The easiest way to recreate this is the use of a
specially crafted configuration file, e.g. containing the line:
FirewallPorts AAAAA<in total 2147483610 As>
This line triggers the needed tor_asprintf call which eventually
leads to an INT_MAX return value from _vscprintf or vsnprintf.
The needed byte for \0 is added to the result, triggering the
overflow and therefore the undefined behaviour.
Casting the value to size_t before addition fixes the behaviour.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Overflowing a signed integer in C is an undefined behaviour.
It is possible to trigger this undefined behaviour in tor_asprintf on
Windows or systems lacking vasprintf.
On these systems, eiter _vscprintf or vsnprintf is called to retrieve
the required amount of bytes to hold the string. These functions can
return INT_MAX. The easiest way to recreate this is the use of a
specially crafted configuration file, e.g. containing the line:
FirewallPorts AAAAA<in total 2147483610 As>
This line triggers the needed tor_asprintf call which eventually
leads to an INT_MAX return value from _vscprintf or vsnprintf.
The needed byte for \0 is added to the result, triggering the
overflow and therefore the undefined behaviour.
Casting the value to size_t before addition fixes the behaviour.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
