res_pjsip: Don't assume a request will have any addresses.

When performing DNS resolution the failover code present in
res_pjsip currently assumes that a request will always have
at least one viable address. In practice this is not true.
A domain may be used that has no records.

The code now checks that at least one address exists on the
request which prevents looping.

ASTERISK-26364 #close

Change-Id: Ic0761b0264864acd85915c94d878a81624940f4c

diff --git a/res/res_pjsip.c b/res/res_pjsip.c
index 34edc8ca511ccd7e1e8c6fb12accadce4395afc0..8ecdb03825383135f9480272251ec36a7ae4f3d6 100644 (file)
--- a/res/res_pjsip.c
+++ b/res/res_pjsip.c
@@ -3578,7 +3578,7 @@ int ast_sip_failover_request(pjsip_tx_data *tdata)
 {
        pjsip_via_hdr *via;
 
-       if (tdata->dest_info.cur_addr == tdata->dest_info.addr.count - 1) {
+       if (!tdata->dest_info.addr.count || (tdata->dest_info.cur_addr == tdata->dest_info.addr.count - 1)) {
                /* No more addresses to try */
                return 0;
        }