Hi all
Quick question, how does one turn channel_t into an IP address, e.g. given a circuit_t how do I get the IP address of the previous and next hop (noting that they might not be in the consensus so I cant use the identity hash). I can see the information is in the connection_t struct but I don't know how to get that from the channel/circuit.
Any help appreciated.
Thanks Gareth
On Thu, Jul 24, 2014 at 12:20:52PM +0100, Gareth Owen wrote:
Hi all
Quick question, how does one turn channel_t into an IP address, e.g. given a circuit_t how do I get the IP address of the previous and next hop (noting that they might not be in the consensus so I cant use the identity hash). I can see the information is in the connection_t struct but I don't know how to get that from the channel/circuit.
The IP address (and the fact that the channel_t even is over IP) are specific to particular transport; you'll have to downcast it to a channel_tls_t using the BASE_CHAN_TO_TLS macro and then look at the or_connection_t pointer in that structure.
Andrea
Thanks for taking the time to reply and for the advice. I have just this second discovered this method:
TO_OR_CIRCUIT(circ)->p_chan->get_remote_descr(TO_OR_CIRCUIT(circ)->p_chan, 0)
which returns the endpoint as a string. I wonder, is this safer/future proof or should this approach be discouraged?
Best Gareth
On 24 July 2014 12:20, Gareth Owen gareth.owen@port.ac.uk wrote:
Hi all
Quick question, how does one turn channel_t into an IP address, e.g. given a circuit_t how do I get the IP address of the previous and next hop (noting that they might not be in the consensus so I cant use the identity hash). I can see the information is in the connection_t struct but I don't know how to get that from the channel/circuit.
Any help appreciated.
Thanks Gareth
-- Dr Gareth Owen Senior Lecturer School of Computing, University of Portsmouth
Tel: 02392 846423 Web: ghowen.me
On Thu, Jul 24, 2014 at 01:55:43PM +0100, Gareth Owen wrote:
Andrea
Thanks for taking the time to reply and for the advice. I have just this second discovered this method:
TO_OR_CIRCUIT(circ)->p_chan->get_remote_descr(TO_OR_CIRCUIT(circ)->p_chan, 0)
which returns the endpoint as a string. I wonder, is this safer/future proof or should this approach be discouraged?
Don't call channel methods directly like that. Do call something like channel_get_actual_remote_descr(), channel_get_actual_remote_address(), or channel_get_canonical_remote_descr() (see code in channel.c for differences among them) on TO_OR_CIRCUIT(circ)->p_chan.
Note: only do this if you want a string to show the user or something like that. If you're going to parse it, it's very much brittle and not future- proof.
-
Andrea Shepard -
Gareth Owen