Add hex2pcap

2026-10-05 20:07:31 +02:00
parent 477e6c0ee7
commit 5b5cf211d0
19 changed files with 1694 additions and 0 deletions
@@ -26,6 +26,12 @@ Builds a single-packet pcap file from pasted hex.

  It walks IPv6 extension headers and uses the final destination from a routing header in the pseudo-header. Fragments only get their IP header fixed.

+  The end of the layer 3 field marks where the headers end. The fix uses that boundary for two more fields:
+  - **TCP data offset**: set to the length of the TCP header, including options, in the layer 3 field.
+  - **SCTP chunk length**: set for the last chunk whose header starts in the layer 3 field. It covers the rest of the packet, so paste chunk data without padding. If the payload already includes padding, the tool keeps a chunk length that matches. Chunks bundled before it keep their own lengths.
+
+  The IPv4 IHL and the IPv6 extension header lengths are taken as entered, because they are what says where the IP options end. If an IPv4 option doesn't fit inside the IHL, you get a warning. When the layer 3 field is empty, these two fields are left unchanged.
+
  The IP header is taken to start at the layer 3 field. If that field is empty, the tool parses the link-layer header to find it: Ethernet (including VLAN and QinQ), Linux SLL or SLL2.
 - **Link type**: *Auto* picks Raw IP when layer 2 is empty and layer 3 is set, and Ethernet otherwise. You can also pick a link type from the list or enter any numeric LINKTYPE.
 - **Preview** shows the fixups that were applied and a hex dump coloured by layer, with changed bytes underlined. **Download pcap** returns the file.