Re: [Devel] [Users] nathelper/rtpproxy when both SIP UA are behind same NAT

actually, this would be better avp_printf("i:401", "$rd"); if ( avp_check("i:401", "eq/$src_ip/g") ) { xlog("L_INFO", "\"$si\" == \"$rd\" "); } Tavis P wrote: > Opps i made a mistake, instead of "avp_write" you need to use > "avp_printf" to store the pseudo variable into an AVP > and when you are doing the comparison with avp_check you need an alias > defined for the second AVP otherwise you might end up comparing the AVP > with a literal value > > > modparam( "avpops", "avp_aliases", "dest_ip=i:401" ) > > avp_printf("i:400", "$si"); > avp_printf("i:401", "$rd"); > > if ( avp_check("i:400", "eq/$dest_ip/g") ) > { > xlog("L_INFO", "\"$si\" == \"$rd\" "); > } > > > Norman Brandinger wrote: > > > > > > > > >> I agree that the solution that was presented is BAD for the reasons >> stated by both of us and probably more :) >> >> Perhaps using $Ri after the successful lookup() and comparing it to >> the $src_ip AVP would work. >> >> The problem was trying to compare a pseudo variable with an AVP. >> >> >> The doc <snipped below> does not state that pseudo variables can be >> used by avp_write(). >> >> Pseudo-variables can be used with following modules of OpenSER: >> >> * avpops - function “avp_printf()” >> * xlog - functions “xlog()” and “xdbg()” >> >> I did try to use avp_write() to save a pseudo variable to an AVP but >> was unsuccessful. >> >> Do you have an example of writing a pseudo variable to an AVP ? >> >> Regards, >> Norm >> >> >> >> Tavis P wrote: >> >> >> >> >> >> >> >>> Another, more lightweight solution, is: >>> >>> After a successful lookup(location) you can compare the received IP >>> address ($si) with the destination domain/ip address returned from >>> the >>> "lookup" function call ($rd), i think these two pieces of information >>> are reliable for this purpose >>> >>> This way you don't have to make extra database calls to determine >>> locality >>> >>> Also if you want to compare pseudo variables you can first write >>> them to >>> an AVP using "avp_write" and then you can make use of "avp_check" >>> with >>> data sourced from a pseudo variable >>> >>> Norman Brandinger wrote: >>> >>> >>> >>> >>> >>> >>> >>> >>> >>>> I have looked into the problem related to saving saving resources by >>>> not calling rtpproxy or mediaproxy when both the caller and >>>> callee are >>>> behind the same NAT. >>>> >>>> This topic has been discussed many times however, there have been no >>>> "working" examples, or even partial examples posted (that I'm aware >>>> of). >>>> >>>> Below is a solution to the problem, but is a BAD hack at best. >>>> >>>> This solution is BAD because AVP's are added to the usr_preferences >>>> table during the registration process, but there is no notification >>>> that a registration has expired and is no longer valid. A cron job >>>> could be run periodically to delete all received_ip AVP's with no >>>> matching entry in the location table, but this is another hack to >>>> fix >>>> the first hack. >>>> >>>> The solution is BAD because a database calls must be made to save >>>> the >>>> received_ip address into an AVP, then another database call must be >>>> made to reload the value just so that it can be tested against the >>>> caller's $src_ip. A pseudo variable $Ri already exists that >>>> contains >>>> the value we use in received_ip, but I have not been able to find a >>>> way for avp_check() to use $Ri. >>>> >>>> The solution is BAD because it will fail when the SIP device(s) are >>>> behind more than a single NAT router. I believe this is not an >>>> issue >>>> for 95% of the users and 99% of the small office or home users. >>>> >>>> I think that a better solution would be to enhance avp_check() to >>>> accept pseudo variables for the "value" parameter. This would >>>> remove >>>> the need for any database calls. >>>> >>>> I'm cross-posting this response to the developers list to bring this >>>> to their attention and ask for suggestions (it's possible that I've >>>> totally missed something). If a decision is made to open the avpops >>>> module to pseudo variables (other than just avp_print()), I would >>>> suggest the following be looked at: >>>> >>>> avp_check() the value parm should accept pseudo variables >>>> avp_write() the value parm should accept pseudo variables >>>> avp_pushto() the name parameter should accept pseudo variables >>>> avp_op() the value parameter should accept pseudo variables >>>> >>>> Regards, >>>> Norm >>>> >>>> >>>> 1) During REGISTER processing, place the following code. I would >>>> suggest that you put the code "after" all authentication checks and >>>> "after" the save("location") statement. >>>> >>>> # Delete any previously saved IP addressess from the user. >>>> avp_db_delete("$from/username","s:received_ip"); >>>> >>>> # Save the source IP address of the user into an AVP called >>>> received_ip. >>>> # The saved IP address should be the public address of the NAT >>>> router. >>>> avp_write("$src_ip", "s:received_ip"); >>>> >>>> # Save the AVP received_ip into the usr_preferences tables >>>> associated >>>> with the user that just registered >>>> avp_db_store("$from/username","s:received_ip"); >>>> >>>> 2) During INVITE processing (or wherever you make the decision to >>>> use >>>> or not use rtpproxy / mediaproxy) , place the following code. >>>> >>>> >>>> #--------------------------------------------------------------------------- >>>> >>>> >>>> >>>> # Are the caller and callee behind the same NAT ? >>>> >>>> #--------------------------------------------------------------------------- >>>> >>>> >>>> >>>> avp_db_load("$to/username", "s:received_ip"); >>>> if (avp_check("s:received_ip", "eq/$src_ip")) { >>>> setflag(CALLER_AND_CALLEE_ ARE_BEHIND_THE_SAME_NAT); >>>> }; >>>> >>>> >>>> >>>> _______________________________________________ >>>> Devel mailing list >>>> Devel(a)openser.org >>>> http://openser.org/cgi-bin/mailman/listinfo/devel >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>> >>> >>> >>> >>> >> >> >> >> >> > _______________________________________________ > Users mailing list > Users(a)openser.org > http://openser.org/cgi-bin/mailman/listinfo/users > > > > > > > >