Here is is the relevant section of kamailio.cfg
$var(tempfU) = $fU; #!ifdef WITH_IPAUTH if((!is_method("REGISTER")) && allow_source_address() && $au == "") { # Loading $fU from database using IP
sql_pvquery("elxpbx", "SELECT name FROM sip WHERE host = '$si' AND sippasswd IS NULL", "$var(tempfU)");
# source IP allowed return; }
The problem is that when host= somefqdn.com the above will fail since $si will always be an IP address as far as I can tell. More often than not host= is a fqdn and requiring it to always be an IP address is not an option. Converting it to IP before storing it in the DB is also not an option because it needs to be able to work of the IP address changes.
So how can the above be done to accomodate the possibility that host= somefqdn.com or an IP address. Preferably in such a way that it can scale to hundreds/thousands of rows in the database without slowing things down or crashing.
Authentication by IP address must be done by IP address only, DNS names must not be allowed. Period. By definition.
What you want can be achieved with dns_int_match_ip() function provided by ipops module. But keep in mind it is slow because of DNS lookup.
On Sunday 08 March 2015 13:38:52 canuck15 wrote:
Here is is the relevant section of kamailio.cfg
$var(tempfU) = $fU; #!ifdef WITH_IPAUTH if((!is_method("REGISTER")) && allow_source_address() && $au == "") { # Loading $fU from database using IP
sql_pvquery("elxpbx", "SELECT name FROM sip WHERE host = '$si'AND sippasswd IS NULL", "$var(tempfU)");
# source IP allowed return; }The problem is that when host= somefqdn.com the above will fail since $si will always be an IP address as far as I can tell. More often than not host= is a fqdn and requiring it to always be an IP address is not an option. Converting it to IP before storing it in the DB is also not an option because it needs to be able to work of the IP address changes.
So how can the above be done to accomodate the possibility that host= somefqdn.com or an IP address. Preferably in such a way that it can scale to hundreds/thousands of rows in the database without slowing things down or crashing.
SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
Hello,
On 08/03/15 21:38, canuck15 wrote:
Here is is the relevant section of kamailio.cfg
$var(tempfU) = $fU; #!ifdef WITH_IPAUTH if((!is_method("REGISTER")) && allow_source_address() && $au == "") { # Loading $fU from database using IP
sql_pvquery("elxpbx", "SELECT name FROM sip WHERE host = '$si'AND sippasswd IS NULL", "$var(tempfU)");
# source IP allowed return; }The problem is that when host= somefqdn.com the above will fail since $si will always be an IP address as far as I can tell. More often than not host= is a fqdn and requiring it to always be an IP address is not an option. Converting it to IP before storing it in the DB is also not an option because it needs to be able to work of the IP address changes.
So how can the above be done to accomodate the possibility that host= somefqdn.com or an IP address. Preferably in such a way that it can scale to hundreds/thousands of rows in the database without slowing things down or crashing.
as first remark, note that permissions module can work with hostanmes in the address table.
On the other hand, having what you want might not work. If you want to test if a request comes from xyz.com, doing a dns query on xyz.com can return a different IP than what was used for sending. If xyz.com has many IP addresses associated with and they do load balancing, they are usually returning just a subset of their IP addresses, not all of them.
In this case, the best is to discover the subnet addresses used by xyz.com and store them in the address table, then use permissions in the config.
Otherwise, you can try by doing a query and extract all hostnames from the database with sqlops and then loop through them and test with the functions from ipops module. You must have a fast dns server in order to not slow down the processing in the case you have lots of hostnames.
Cheers, Daniel
After further investigation I am considering the ipops module dns_query() command. http://kamailio.org/docs/modules/4.3.x/modules/ipops.html
It needs to be fast to prevent a bottleneck so I have a few things I need to verify.
Will it save to/check internal DNS resolver cache first and if so how many dns_querys can this handle before it starts to affect performance or use excessive amounts of memory etc?
If not what can I use that uses the DNS resolver cache?
For what I am doing it would need to scale to many hundreds of DNS Authenticated SIP trunks. So perhaps hundreds of querys/sec I suppose. Perhaps many thousands of SIP extensions using those trunks but not directly using DNS authentication themselves.
On 3/9/2015 4:27 AM, Daniel-Constantin Mierla wrote:
Hello,
On 08/03/15 21:38, canuck15 wrote:
Here is is the relevant section of kamailio.cfg
$var(tempfU) = $fU; #!ifdef WITH_IPAUTH if((!is_method("REGISTER")) && allow_source_address() && $au == "") { # Loading $fU from database using IP
sql_pvquery("elxpbx", "SELECT name FROM sip WHERE host = '$si'AND sippasswd IS NULL", "$var(tempfU)");
# source IP allowed return; }The problem is that when host= somefqdn.com the above will fail since $si will always be an IP address as far as I can tell. More often than not host= is a fqdn and requiring it to always be an IP address is not an option. Converting it to IP before storing it in the DB is also not an option because it needs to be able to work of the IP address changes.
So how can the above be done to accomodate the possibility that host= somefqdn.com or an IP address. Preferably in such a way that it can scale to hundreds/thousands of rows in the database without slowing things down or crashing.
as first remark, note that permissions module can work with hostanmes in the address table.
On the other hand, having what you want might not work. If you want to test if a request comes from xyz.com, doing a dns query on xyz.com can return a different IP than what was used for sending. If xyz.com has many IP addresses associated with and they do load balancing, they are usually returning just a subset of their IP addresses, not all of them.
In this case, the best is to discover the subnet addresses used by xyz.com and store them in the address table, then use permissions in the config.
Otherwise, you can try by doing a query and extract all hostnames from the database with sqlops and then loop through them and test with the functions from ipops module. You must have a fast dns server in order to not slow down the processing in the case you have lots of hostnames.
Cheers, Daniel
Thanks for this suggestion.
I ended up replacing permissions module |allow_source_address() with sql queries. |Not sure how well it will scale but seems to work ok on a test system. |In order to use allow_source_address() I would need to save all returned IP addresses in the database. The problem with that is it will not automatically update if DNS changes||. I still have not ruled out doing that if this ends up bogging down when the server gets busy.
Excessive DNS queries/delays do not appear to be a problem with this because it is cached in Kamailio DNS resolver. It renews every 120 seconds by default unless configured otherwise.
You can view the contents of the dns resolver by running "kamcmd dns.view".
Here is the replaced IPAUTH section I created for anyone who may be interested.
modparam("sqlops", "sqlcon", "kamailio=>unixodbc:///kamailio-connector") . . . #!ifdef WITH_IPAUTH if((!is_method("REGISTER")) && $au == "") { sql_query("kamailio", "SELECT ip_addr FROM address", "ka"); if($dbr(ka=>rows)>0) { $var(dnsname) = $null; $var(i) = 0; while($var(i)<$dbr(ka=>rows)) { $var(dnsname) = $dbr(ka=>[$var(i),0]); if (dns_int_match_ip("$var(dnsname)", "$si")) { # source IP allowed, leave the 'while' parent loop. $var(i) = $dbr(ka=>rows); return; } $var(i) = $var(i) + 1; } return; } sql_result_free("ka"); return; } |
On 3/9/2015 4:27 AM, Daniel-Constantin Mierla wrote:
Hello,
On 08/03/15 21:38, canuck15 wrote:
Here is is the relevant section of kamailio.cfg
$var(tempfU) = $fU; #!ifdef WITH_IPAUTH if((!is_method("REGISTER")) && allow_source_address() && $au == "") { # Loading $fU from database using IP
sql_pvquery("elxpbx", "SELECT name FROM sip WHERE host = '$si'AND sippasswd IS NULL", "$var(tempfU)");
# source IP allowed return; }The problem is that when host= somefqdn.com the above will fail since $si will always be an IP address as far as I can tell. More often than not host= is a fqdn and requiring it to always be an IP address is not an option. Converting it to IP before storing it in the DB is also not an option because it needs to be able to work of the IP address changes.
So how can the above be done to accomodate the possibility that host= somefqdn.com or an IP address. Preferably in such a way that it can scale to hundreds/thousands of rows in the database without slowing things down or crashing.
as first remark, note that permissions module can work with hostanmes in the address table.
On the other hand, having what you want might not work. If you want to test if a request comes from xyz.com, doing a dns query on xyz.com can return a different IP than what was used for sending. If xyz.com has many IP addresses associated with and they do load balancing, they are usually returning just a subset of their IP addresses, not all of them.
In this case, the best is to discover the subnet addresses used by xyz.com and store them in the address table, then use permissions in the config.
Otherwise, you can try by doing a query and extract all hostnames from the database with sqlops and then loop through them and test with the functions from ipops module. You must have a fast dns server in order to not slow down the processing in the case you have lots of hostnames.
Cheers, Daniel
-
canuck15 -
Daniel-Constantin Mierla -
Sergey Okhapkin