From 50524cb5aee1f1f4464f60467122a44befc11203 Mon Sep 17 00:00:00 2001 From: zedddie Date: Tue, 17 Mar 2026 22:27:24 +0100 Subject: use ihl to derive port bytes --- src/sniffing/headers.rs | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'src') diff --git a/src/sniffing/headers.rs b/src/sniffing/headers.rs index a5b0480..2472981 100644 --- a/src/sniffing/headers.rs +++ b/src/sniffing/headers.rs @@ -52,13 +52,15 @@ pub fn sniff_raw_packets(packet: &Packet) -> SniffedPacket { let ver = packet[0] >> 4; match ver { 4 => { - let dst_port = Port::from_be_bytes([packet[22], packet[23]]); + // Internet Header Length (IHL). + let ihl = (packet[0] & 0x0F) as usize * 4; + let dst_port = Port::from_be_bytes([packet[ihl+2], packet[ihl+3]]); let dns; if dst_port == 53 { dns = true; } else { dns = false; }; // FIXME: hardcoded IPv4 port offset let v4 = PacketInfo::V4{ src_ip: ::try_from(&packet[12..16])?, - src_port: Port::from_be_bytes([packet[20], packet[21]]), + src_port: Port::from_be_bytes([packet[ihl], packet[ihl+1]]), dst_ip: ::try_from(&packet[16..20])?, dst_port, protocol: match packet[9] { -- cgit v1.2.3