diff options
author | Guy Harris <gharris@sonic.net> | 2021-03-03 15:19:18 -0800 |
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committer | Guy Harris <gharris@sonic.net> | 2021-03-03 15:19:18 -0800 |
commit | b8d90bb54823e8205e5a7412866d89f8eda1fd96 (patch) | |
tree | 7aa394db888ec329e7ecf6b36b608a39942b99b6 /wiretap | |
parent | e536166b38040cf477147e4eaf9fc92d93204e69 (diff) |
netxray: update a comment.
Add additional information derived from more reverse engineering.
Diffstat (limited to 'wiretap')
-rw-r--r-- | wiretap/netxray.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/wiretap/netxray.c b/wiretap/netxray.c index 0e778e3ef0..ed759bf232 100644 --- a/wiretap/netxray.c +++ b/wiretap/netxray.c @@ -280,12 +280,17 @@ struct netxrayrec_1_x_hdr { * * xxx[0]: ATM traffic type and subtype in the low 3 bits of * each nibble, and flags(?) in the upper bit of each nibble. + * Always 0 for 802.11? + * + * xxx[1]: Always 0 for 802.11? * * xxx[2], xxx[3]: for Ethernet, 802.11, ISDN LAPD, LAPB, * Frame Relay, if both are 0xff, there are 4 bytes of stuff * at the end of the packet data, which might be an FCS or * which might be junk to discard. * + * xxx[4-7]: Always 0 for 802.11? + * * xxx[8], xxx[9]: 2 bytes of a flag word? If treated as * a 2-byte little-endian flag word: * @@ -293,11 +298,12 @@ struct netxrayrec_1_x_hdr { * in one ISDN capture it's set in some B2 channel * packets of unknown content (as opposed to the B1 * traffic in the capture, which is PPP) + * 0x0002: Seen in 802.11 - short preamble? Bad CRC? * 0x0004: Some particular type of error? * 0x0008: For (Gigabit?) Ethernet (with special probe?), * 4 bytes at end are junk rather than CRC? * 0x0100: CRC error on ATM? Protected and Not decrypted - * for 802.11? + * for 802.11? Bad CRC? Short preamble? * 0x0200: Something for ATM? Something else for 802.11? * 0x0400: raw ATM cell * 0x0800: OAM cell? @@ -346,18 +352,30 @@ struct netxrayrec_1_x_hdr { * The field appears to be somewhat random in some captures, * however. * + * xxx[10]: for 802.11, always 0? + * * xxx[11]: for 802.11, 0x05 if the packet is WEP-encrypted(?). * * xxx[12]: for 802.11, channel number. * - * xxx[13]: for 802.11, data rate. + * xxx[13]: for 802.11, data rate, in 500 Kb/s units. * * xxx[14]: for 802.11, signal strength. * * xxx[15]: for 802.11, noise level; 0xFF means none reported, * 0x7F means 100%. * + * xxx[16-19]: for 802.11, PHY header, at least for {HR/}DSSS, + * in at least one capture. + * In another capture, xxx[16] appears to be the + * data rate in 500 Kb/s units + * Chip-dependent stuff? + * * xxx[20-25]: for 802.11, MAC address of sending machine(?). + * + * xxx[26]: for 802.11, one of 0x00, 0x01, 0x03, or 0x0b? + * + * xxx[27]: for 802.11, one of 0x00 or 0x30? */ struct netxrayrec_2_x_hdr { guint32 timelo; /* lower 32 bits of time stamp */ |