[Devel] append_branch

[Bogdan-Andrei Iancu]

Klaus Darilion wrote:
> Bogdan-Andrei Iancu wrote:
>> Hi Klaus,
>>
>> actually append_branch() does not store any path variable. Only 
>> registrar module sets it when doing lookup().
>
> Yes. But what happens if after lookup I call append_branch and add 
> another URI:
> route  { lookup(); # sets RURI/DURI/PATH
>          append_branch();
>          rewriteuri("sip:foo at bar"); # this branch reuses
>                                     # DURI and PATH from above
>          t_relay();
> }
>
> this one also will use the previous path - not?
>
> int append_branch(struct sip_msg* msg,....
> {
> ...
>
>         /* copy the path string */
>         if (path && path->len && path->s) {
> ...
>
> }
>
the new branch will not use the already set path as the script 
"append_branch" functions does not pass this parameter to the internal 
"append_branch" fct.


>> BTW, this lead to a related issue I found - stateless forward does 
>> not obey the path info.
>>
>> What you are saying about resetting the path after append_branch() is 
>> more related here to a logical issue: when creating a new branch (via 
>> append), all the info pushed into the new branch should be reset? 
>
> Not sure how it should be done - probably I still do not know what 
> append branch exactly does. I try to write down my understanding of 
> branches and please correct me:
>
> When a request enters openser.cfg the message has one branch 
> (branches[0]).
>
> Any manipulation or lookup of RURI and DURI will be done on branches[0].
>
> If I call append_branch, the current RURI/DURI/PATH (identically to 
> branches[0]) will be copied into the next empty branch - in this case 
> branches[1].
>
> Then further URI/DURI manipulation will not touch branches[1] anymore.
>
> Is the above correct?
yes, this is correct. The same applies for the branch flags and forced 
socket (along RURI, DURI and PATH)
>
> Thus IMO it would make sense to reset all parameters of branches[0] to 
> avoid confusion between the existing (copied into branches[x]) and the 
> fresh new branch.
I agree, but note that there is no equivalent of branch[0]. all info for 
branch 0 is kept directly into the SIP request. The additional branches 
(>0) are kept in an array of branch structures.

so, after doing append_branch(), all per-branch info from the request 
will be reset (following the above logic).

if we expand a bit the idea, it should be a different logic behind 
append_branch(); and append_branch(URI); :
    append_branch() - appends current branch[0] (RURI) as a new branch; 
the request must be reset after;
    append_branch(URI) - appends a new URI as a new branch; this new URI 
should not inherit and reset anything from branch[0].

regards,
bogdan
>
> regards
> klaus
>
> > like
>> append_branch() will reset duri, bflags, path, forced socket ,leaving 
>> a new virgin branch 0 (ruri) to work with??
>>
>> regards,
>> bogdan
>>
>> Klaus Darilion wrote:
>>> Hi!
>>>
>>> AFAIK append_branch copies the current RURI, DURI and PATH into a 
>>> new branch. Then, if I push a new RURI I also have to delete the 
>>> previous DURI using resetdsturi(). Thus I guess we would also need a 
>>> function to reset the PATH too - don't we?
>>>
>>> regards
>>> klaus
>
>