components/mdns: wrong Message compression detect

Old behavior assumes message compressed when any of 2 most significant bits are set,
But in fact Message compressed only when both those bits are set to 1.

Also maximal label length should be 63 bytes.

diff --git a/components/mdns/mdns.c b/components/mdns/mdns.c
index 40b4c709615a050c504ac2632a94c7331e450509..c77283e071a2252bc6b6b5c0cf7e36a08e48286c 100644 (file)
--- a/components/mdns/mdns.c
+++ b/components/mdns/mdns.c
@@ -555,9 +555,9 @@ static const uint8_t * _mdns_read_fqdn(const uint8_t * packet, const uint8_t * s
             return NULL;
         }
         uint8_t len = start[index++];
-        if ((len & 0xC0) == 0) {
-            if (len > 64) {
-                //length can not be more than 64
+        if (len < 0xC0) {
+            if (len > 63) {
+                //length can not be more than 63
                 return NULL;
             }
             uint8_t i;