[Kamailio-Users] new feature: update sip msg content in request route

[Daniel-Constantin Mierla]

Hello,

I just committed a new function in modules_k/textops - 
msg_apply_changes(). Hopefully the name is suggestive enough - the 
function applies the changes done to the content of sip message - e.g., 
if you added a new header, once you use the function, that header will 
become visible in config file.

Therefore the function tries to overcome the overhead of looping various 
messages back to sip server just because modifications were not visible 
once done. Another benefit is ability to access latest value for a field 
(being header or body content) in case of need to hashes or signatures 
for security purposes.

The function can be used only in request route for now. Be carefully 
when using it, since it changes the expectation you had so far of always 
working on initially received sip message. Once the function is sued, 
initial content is lost forever. Since it builds a new buffer and 
re-parses, it is not very recommended to use it extensively.

Example of usage:

append_hf("My-Header: yes\r\n");
if(msg_apply_changes())
{
        # msg buffer has a new content
        if(is_present_hf("My-Header"))
        {
               # will get always here
       }
}

Testing and feedback is welcome!

Cheers,
Daniel