net: mdns_resolver: Fix malformed MDNS response

The query->len does not take 'Terminator' into account, shift over one byte to prevent overwriting it with next field (Type). This fixes mdns_resolver sample. Fixes: 87eb552 (net/dns: Switch mdns responder to new net_pkt API) Signed-off-by: Loic Poulain <[email protected]>
adamkondraciuk · Jun 12, 2019 · 3189da5 · 3189da5
1 parent 4f4adae
commit 3189da5
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/subsys/net/lib/dns/mdns_responder.c b/subsys/net/lib/dns/mdns_responder.c
@@ -154,6 +154,9 @@ static void add_answer(struct net_buf *query, enum dns_rr_type qtype,
 		*prev = strlen(prev) - 1;
 	}
 
+	/* terminator byte (0x00) */
+	query->len += 1;
+
 	offset = DNS_MSG_HEADER_SIZE + query->len;
 	UNALIGNED_PUT(htons(qtype), (u16_t *)(query->data+offset));