s4-resolv: fix dns_ex so as to fail correctly when a name does not exist

[kai/samba.git] / source4 / libcli / resolve / dns_ex.c

diff --git a/source4/libcli/resolve/dns_ex.c b/source4/libcli/resolve/dns_ex.c
index 9467521394efb2afa5f4b9dcd11e9ed1d69a03dc..4f46235a9ff57ae885ba020d75e1c94c00e4ac37 100644 (file)
--- a/source4/libcli/resolve/dns_ex.c
+++ b/source4/libcli/resolve/dns_ex.c
@@ -393,6 +393,12 @@ static void run_child_dns_lookup(struct dns_ex_state *state, int fd)
                c = get_a_aaaa_records(state, state->name.name, state->port);
        }
 
+       /* This line in critical - if we return without writing to the
+        * pipe, this is the signal that the name did not exist */
+       if (c.count == 0) {
+               goto done;
+       }
+
        addrs = talloc_strdup(state, "");
        if (!addrs) {
                goto done;
@@ -521,6 +527,9 @@ static void pipe_handler(struct tevent_context *ev, struct tevent_fd *fde,
        }
 
        if (ret <= 0) {
+               /* The check for ret == 0 here is important, if the
+                * name does not exist, then no bytes are written to
+                * the pipe */
                DEBUG(3,("dns child failed to find name '%s' of type %s\n",
                         state->name.name, (state->flags & RESOLVE_NAME_FLAG_DNS_SRV)?"SRV":"A"));
                composite_error(c, NT_STATUS_OBJECT_NAME_NOT_FOUND);