decode/tcp: improve pointer hygene

Avoid NULL pointer calculations.
10 months ago · 86a363b1bc
parent 0dfa5793db
commit 86a363b1bc
1 changed files with 5 additions and 6 deletions
--- a/src/decode-tcp.c
+++ b/src/decode-tcp.c
@ -138,12 +138,11 @@ static void DecodeTCPOptions(Packet *p, const uint8_t *pkt, uint16_t pktlen)
                    break;
                case TCP_OPT_SACK:
                    SCLogDebug("SACK option, len %u", olen);
-                    if ((olen != 2) &&
-                           (olen < TCP_OPT_SACK_MIN_LEN ||
-                            olen > TCP_OPT_SACK_MAX_LEN ||
-                            !((olen - 2) % 8 == 0)))
-                    {
-                        ENGINE_SET_EVENT(p,TCP_OPT_INVALID_LEN);
+                    if (olen == 2) {
+                        /* useless, but common empty SACK record */
+                    } else if (olen < TCP_OPT_SACK_MIN_LEN || olen > TCP_OPT_SACK_MAX_LEN ||
+                               !((olen - 2) % 8 == 0)) {
+                        ENGINE_SET_EVENT(p, TCP_OPT_INVALID_LEN);
                    } else {
                        if (p->l4.vars.tcp.sack_set) {
                            ENGINE_SET_EVENT(p,TCP_OPT_DUPLICATE);