You can use dns name as SIP realm. Then you can silencly drop messages that contains IP address to From/To field
Example https://github.com/2600hz/kazoo-configs-kamailio/blob/master/kamailio/traffi...
вт, 10 окт. 2017 г., 13:36 Daniel-Constantin Mierla miconda@gmail.com:
Hello,
On 09.10.17 12:17, Mark Boyce wrote:
Hi Daniel,
Thanks, I see tcpops lets us set the lifetime … although it’s not really
the length of the lifetime that concerns me.
I guess I’m thinking more a SIP TCP Firewall type of system. If someone
is scanning/ddos/etc I don’t think we should be sending a response at all, unless there’s something I’ve missed?
usually is better not to send a response, especially when matching the attack first time, so it doesn't discover it is a sip server. If the attacker already knows, sometimes it helps to just send a 200 ok response, because that may make the scanning script stop, because it thinks it has discovered a good password.
We could just use fail2ban but that would mean spawning an executable or
writing each attempt to logs.
That's an option used by many out there, a matter of preferences.
Maybe I’m doing things the wrong way round but I can’t help feeling that
letting kamailio see the attempts and log stats, sources, etc is more useful than an iptables drop?
I typically do it with kamailio, as I am more familiar with.
Of course, there is always the option to add a function to close a tcp connection (as alternative to setting lifetime to 1 sec), but one has to go and code it, tcpops is a good place for such addition.
Cheers, Daniel
Cheers, Mark
On 9 Oct 2017, at 10:51, Daniel-Constantin Mierla miconda@gmail.com
wrote:
Hello,
tcpops module offers a function to set the lifetime of a tcp connection, so you can set it to 1 second:
-https://www.kamailio.org/docs/modules/stable/modules/tcpops.html
Core offers a function to instruct closing the connection once a reply has been sent, but it seems you don't want to send anything back.
Cheers, Daniel
On 08.10.17 22:11, Mark Boyce wrote:
Hi all
Just working on some connections security filters on a Kamailio
install. The security goes something like this;
In REQINT … if source_ip is not in customers IP white-list then just
exit
This works fine for UDP where packets are just ignored if they don’t
come from a trusted IP.
However on TCP this leads to the connection staying open until it
either times out or the source disconnects. Which feels untidy.
Is there a way to say close the TCP connection from within the config
script?
Thanks
Mark
-- Daniel-Constantin Mierla www.twitter.com/miconda -- www.linkedin.com/in/miconda Kamailio Advanced Training - www.asipto.com Kamailio World Conference - www.kamailioworld.com
-- Daniel-Constantin Mierla www.twitter.com/miconda -- www.linkedin.com/in/miconda Kamailio Advanced Training - www.asipto.com Kamailio World Conference - www.kamailioworld.com
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