🐞 fix(calc_gtp1_hdr_len): fix endless loop for ext hdr

1 files changed, 4 insertions, 4 deletions

diff --git a/src/packet/gtp1_utils.h b/src/packet/gtp1_utils.h
index 3ca4235..2077d9b 100644
--- a/src/packet/gtp1_utils.h
+++ b/src/packet/gtp1_utils.h
@@ -209,15 +209,15 @@ static inline uint16_t calc_gtp1_hdr_len(const char *data, uint16_t len)
             {
                 return 0;
             }
-            uint8_t ext_hdr_len = *((char *)data + offset) * 4;
+            uint8_t ext_hdr_len = *((char *)data + offset) * 4 - 2;
             if (offset + ext_hdr_len > len)
             {
                 return 0;
             }
-            offset += ext_hdr_len; // skip extension header
-            next_ext_hdr = *((char *)data + offset - 1);
+            offset += ext_hdr_len + 1; // skip extension header
+            next_ext_hdr = *((char *)data + offset);
         }
-        return offset;
+        return offset+1; //next_ext_hdr==0 occupy 1 byte
     }
     else
     {