12 Oct
2014
12 Oct
'14
3:48 a.m.
On 12/10/14 09:37, Juha Heinanen wrote:
while doing pua module tests in db_mode=2, i used
pua_mi to send two
publish requests. in both of them id and etag params had value '.'.
first generated publish request without sip-if-match header (as it
should) and after 200 ok was received, record was properly inserted to
pua table with etag value a.1413029856.5521.112.0 and empty pres_id.
the second for a different pres_uri however resulted in error in
presence server:
Oct 12 10:06:42 siika /usr/bin/pres-serv[5522]: ERROR: presence [presentity.c:807]:
update_presentity(): No E_Tag match a.1413029856.5521.112.0
after digging into it, i found with wireshark that the second publish
indeed included sip-if-match header with that etag value even when it
was initial publish (etag and id params '.') for another pres_uri.
then i took a look at pua source and found that if etag param is null it
is not included in db query at all leaving only pres_id param to match
against:
ua_pres_t *get_record_puadb(str pres_id, str *etag, ua_pres_t *result, db1_res_t
**dbres)
{
int n_query_cols = 0, nr_rows;
...
q_cols[n_query_cols] = &str_pres_id_col;
q_vals[n_query_cols].type = DB1_STR;
q_vals[n_query_cols].nul = 0;
q_vals[n_query_cols].val.str_val = pres_id;
n_query_cols++;
if (etag != NULL)
{
q_cols[n_query_cols] = &str_etag_col;
q_vals[n_query_cols].type = DB1_STR;
q_vals[n_query_cols].nul = 0;
q_vals[n_query_cols].val.str_val.s = etag->s;
q_vals[n_query_cols].val.str_val.len = etag->len;
n_query_cols++;
}
...
if(query_fn(pua_db, q_cols, 0, q_vals,
NULL,n_query_cols,0,0,&res) < 0)
{
LM_ERR("DB query error\n");
return(NULL);
}
of course this kind of query matched the just inserted record for
another pres_uri, which is wrong.
how should this be fixed? is it enough to always add etag value to the
query or should also pres_uri be added just in case etags for different
pres_uris would match? or perhaps the best fix would be to skip the
query altogether in send_publish if etag is null?
I think that if it is an initial
publish, then send out directly (I
assume a new etag is going to be generated).
Then, iirc, etag is kind of unique globally per instance if generated by
kamailio, so if it exists, then a query on it would be safe. But if it
is generated by somone else, perhaps we cannot guarantee that, therefore
I think the query has to be done on pres_uri as well to be in safe side
always.
In other words, my impression is that both updates have to be done.
Cheers,
Daniel
has anyone else ever used pua module in db_mode=2?
-- juha
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Daniel-Constantin Mierla
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