Hello, I would like to request a Link-Layer Header Type for USB 2.0 packets. This is intended to be used as a export format from sigrok.
While sigrok contains code to convert D+/D- signals into LINKTYPE_USB_LINUX_MMAPPED, it is a bit limited. One issue is that without dissecting USB Configuration Descriptor, it is impossible to determine endpoint type for non-split transactions. Another issue that without knowing endpoint maximum transfer size (also found in Configuration Descriptor), it is not possible to accurately determine short transfers and thus convert multiple transactions into transfer. If the user is not familiar with these limitations it can be really confusing. I am currently working on OpenVizsla dissector for Wireshark. While LINKTYPE_OPENVIZSLA packets can contain USB 2.0 packets, they also do contain information that is specific to the OpenVizsla itself. The dissector code I have written so far clearly separates OpenVizsla from USB Link-Layer and thus I believe it makes sense to have a separate direct entry point for USB 2.0 packets. The new Link-Layer Header Type is supposed to contain the USB 2.0 packets. That is, anything that appears on the bus between the Start- and End-of-Packet delimiters. The packet format is described in Chapter 8 Protocol Layer of Universal Serial Bus Specification Revision 2.0. Best Regards, Tomasz Moń _______________________________________________ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
