Commit Graph

6 Commits

Author SHA1 Message Date
David Goulet
36a0ae151f dos: Add the DoSRefuseSingleHopClientRendezvous option
This option refuses any ESTABLISH_RENDEZVOUS cell arriving from a client
connection. Its default value is "auto" for which we can turn it on or off
with a consensus parameter. Default value is 0.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2018-01-30 09:18:16 -05:00
David Goulet
acf7ea77d8 dos: Add the connection DoS mitigation subsystem
Defend against an address that has reached the concurrent connection count
threshold.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2018-01-30 09:18:15 -05:00
David Goulet
1bfc91a029 dos: Apply defense for circuit creation DoS
If the client address was detected as malicious, apply a defense which is at
this commit to return a DESTROY cell.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2018-01-30 09:18:15 -05:00
David Goulet
97abb3543b dos: Detect circuit creation denial of service
Add a function that notifies the DoS subsystem that a new CREATE cell has
arrived. The statistics are updated accordingly and the IP address can also be
marked as malicious if it is above threshold.

At this commit, no defense is applied, just detection with a circuit creation
token bucket system.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2018-01-30 09:18:15 -05:00
David Goulet
c05272783d dos: Track new and closed OR client connections
Implement a basic connection tracking that counts the number of concurrent
connections when they open and close.

This commit also adds the circuit creation mitigation data structure that will
be needed at later commit to keep track of the circuit rate.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2018-01-30 09:18:15 -05:00
David Goulet
64149353dd dos: Initial code of Denial of Service mitigation
This commit introduces the src/or/dos.{c|h} files that contains the code for
the Denial of Service mitigation subsystem. It currently contains basic
functions to initialize and free the subsystem. They are used at this commit.

The torrc options and consensus parameters are defined at this commit and
getters are implemented.

Signed-off-by: David Goulet <dgoulet@torproject.org>
2018-01-30 09:18:15 -05:00