New 'DisableNetwork' option to prevent Tor from using the network

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.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/or/router.h b/src/or/router.h
index f9d156cb09..8cc529f86f 100644
--- a/src/or/router.h
+++ b/src/or/router.h
@@ -39,6 +39,8 @@ void router_orport_found_reachable(void);
 void router_dirport_found_reachable(void);
 void router_perform_bandwidth_test(int num_circs, time_t now);
 
+int net_is_disabled(void);
+
 int authdir_mode(const or_options_t *options);
 int authdir_mode_v1(const or_options_t *options);
 int authdir_mode_v2(const or_options_t *options);