dns: fix outputs with 0-len A/AAAA records

src/log-dnslog.c

@@ -138,11 +138,11 @@ static void LogAnswer(LogDnsLogThread *aft, char *timebuf, char *srcip, char *ds
                 " [**] %s [**] TTL %u [**] ", record, entry->ttl);
 
         uint8_t *ptr = (uint8_t *)((uint8_t *)entry + sizeof(DNSAnswerEntry) + entry->fqdn_len);
-        if (entry->type == DNS_RECORD_TYPE_A) {
+        if (entry->type == DNS_RECORD_TYPE_A && entry->data_len == 4) {
             char a[16] = "";
             PrintInet(AF_INET, (const void *)ptr, a, sizeof(a));
             MemBufferWriteString(aft->buffer, "%s", a);
-        } else if (entry->type == DNS_RECORD_TYPE_AAAA) {
+        } else if (entry->type == DNS_RECORD_TYPE_AAAA && entry->data_len == 16) {
             char a[46];
             PrintInet(AF_INET6, (const void *)ptr, a, sizeof(a));
             MemBufferWriteString(aft->buffer, "%s", a);

src/output-json-dns.c

@@ -479,11 +479,11 @@ static void OutputAnswer(LogDnsLogThread *aft, json_t *djs,
     json_object_set_new(js, "ttl", json_integer(entry->ttl));
 
     uint8_t *ptr = (uint8_t *)((uint8_t *)entry + sizeof(DNSAnswerEntry)+ entry->fqdn_len);
-    if (entry->type == DNS_RECORD_TYPE_A) {
+    if (entry->type == DNS_RECORD_TYPE_A && entry->data_len == 4) {
         char a[16] = "";
         PrintInet(AF_INET, (const void *)ptr, a, sizeof(a));
         json_object_set_new(js, "rdata", json_string(a));
-    } else if (entry->type == DNS_RECORD_TYPE_AAAA) {
+    } else if (entry->type == DNS_RECORD_TYPE_AAAA && entry->data_len == 16) {
         char a[46] = "";
         PrintInet(AF_INET6, (const void *)ptr, a, sizeof(a));
         json_object_set_new(js, "rdata", json_string(a));

src/util-lua-dns.c

@@ -214,13 +214,17 @@ static int DnsGetAnswerTable(lua_State *luastate)
             ptr = (uint8_t *)((uint8_t *)answer + sizeof(DNSAnswerEntry) + answer->fqdn_len);
             if (answer->type == DNS_RECORD_TYPE_A) {
                 char a[16] = "";
+                if (answer->data_len == 4) {
                     PrintInet(AF_INET, (const void *)ptr, a, sizeof(a));
+                }
                 lua_pushstring(luastate, "addr");
                 LuaPushStringBuffer(luastate, (uint8_t *)a, strlen(a));
                 lua_settable(luastate, -3);
             } else if (answer->type == DNS_RECORD_TYPE_AAAA) {
-                char a[46];
+                char a[46] = "";
+                if (answer->data_len == 16) {
                     PrintInet(AF_INET6, (const void *)ptr, a, sizeof(a));
+                }
                 lua_pushstring(luastate, "addr");
                 LuaPushStringBuffer(luastate, (uint8_t *)a, strlen(a));
                 lua_settable(luastate, -3);