net: improve check for no IP options
There's no reason we should accept an IP packet with a malformed IHL
field. So ensure that it is exactly 5, not just <= 5.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/net/net.c b/net/net.c
index b27b021..be4374f 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1226,7 +1226,7 @@
if ((ip->ip_hl_v & 0xf0) != 0x40)
return;
/* Can't deal with IP options (headers != 20 bytes) */
- if ((ip->ip_hl_v & 0x0f) > 0x05)
+ if ((ip->ip_hl_v & 0x0f) != 0x05)
return;
/* Check the Checksum of the header */
if (!ip_checksum_ok((uchar *)ip, IP_HDR_SIZE)) {