Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 8, 2022, at 10:47 PM, Tomasz Moń wrote: > On Sun, May 8, 2022 at 8:53 PM Guy Harris wrote: >> At least from a quick look at section 5.2.3 "Physical Bus Topology" of the >> USB 2.0 spec, a given bus can either be a high-speed bus or a full/low-speed >> bus. > > The

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 8, 2022, at 11:09 PM, Tomasz Moń wrote: > Note that end nodes cannot directly communicate with each other. The > communication is always between host and a device. Those two sentences, when combined, imply that either 1) a host is not an end node or

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, May 9, 2022 at 9:21 AM Guy Harris wrote: > On May 8, 2022, at 11:09 PM, Tomasz Moń wrote: > > Note that end nodes cannot directly communicate with each other. The > > communication is always between host and a device. > > Those two sentences, when combined, imply tha

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, May 9, 2022 at 9:17 AM Guy Harris wrote: > On May 8, 2022, at 10:47 PM, Tomasz Moń wrote: > > On Sun, May 8, 2022 at 8:53 PM Guy Harris wrote: > >> At least from a quick look at section 5.2.3 "Physical Bus Topology" of the > >> USB 2.0 spec, a given bus can either

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, May 9, 2022 at 2:48 PM Michael Richardson wrote: > Tomasz Moń via tcpdump-workers wrote: > Guy> "super-speed" is USB 3.0, right? No LINKTYPE_/DLT_ has been > Guy> proposed for the 3.0 link layer, as far as I know. > > > Yes, "super-speed" is USB 3.0. I do

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, 2022-05-09 at 07:47 +0200, Tomasz Moń wrote: > The problematic case (and the reason why full/low-speed bus is > mentioned) is the LINKTYPE_USB_2_0_FULL_SPEED. It is the case when > you capture at the connection between full speed hub and the host > (and possibly full s

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, 2022-05-09 at 08:44 -0400, Michael Richardson wrote: > A capture from a host to a hub with a mix of downstream devices would > seem to include transmissions at different speeds. The problem is only when capturing at full-speed where either the host or hub is full-spee

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 9, 2022, at 1:33 AM, Tomasz Moń wrote: > On Mon, May 9, 2022 at 9:21 AM Guy Harris wrote: >> On May 8, 2022, at 11:09 PM, Tomasz Moń wrote: >> >>> Device to device communication is not possible. >> >> Is the idea that the topology of USB is a tree, with the host a

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 9, 2022, at 1:58 AM, Tomasz Moń wrote: > On Mon, May 9, 2022 at 9:17 AM Guy Harris wrote: >> On May 8, 2022, at 10:47 PM, Tomasz Moń wrote: >>> On Sun, May 8, 2022 at 8:53 PM Guy Harris wrote: At least from a quick look at section 5.2.3 "Physical Bus Topology"

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 9, 2022, at 7:41 AM, Tomasz Moń wrote: > That would require defining pseudoheader that would have to be included > in every packet. Is that really a great burden? > And it would only solve the corner case that the > currently available open-source friendly sniffers

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, 2022-05-09 at 11:52 -0700, Guy Harris wrote: > On May 9, 2022, at 1:58 AM, Tomasz Moń wrote: > > > On Mon, May 9, 2022 at 9:17 AM Guy Harris > > wrote: > > > On May 8, 2022, at 10:47 PM, Tomasz Moń > > > wrote: > > > > On Sun, May 8, 2022 at 8:53 PM Guy Harris > >

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, 2022-05-09 at 12:02 -0700, Guy Harris wrote: > On May 9, 2022, at 7:41 AM, Tomasz Moń wrote: > > > That would require defining pseudoheader that would have to be > > included in every packet. > > Is that really a great burden? I think it would make it harder to und

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 9, 2022, at 12:40 PM, Tomasz Moń wrote: > On Mon, 2022-05-09 at 12:02 -0700, Guy Harris wrote: >> On May 9, 2022, at 7:41 AM, Tomasz Moń wrote: >> >>> That would require defining pseudoheader that would have to be >>> included in every packet. >> >> Is that really

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, 2022-05-09 at 12:52 -0700, Guy Harris wrote: > On May 9, 2022, at 12:40 PM, Tomasz Moń wrote: > > > On Mon, 2022-05-09 at 12:02 -0700, Guy Harris wrote: > > > On May 9, 2022, at 7:41 AM, Tomasz Moń wrote: > > > > > > > That would require defining pseudoheader that

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 9, 2022, at 12:31 PM, Tomasz Moń wrote: > There is no such thing as "low-speed bus" because low-speed is only > allowed for non-hub devices. USB hosts and hubs *must* support atleast > full and high speed. USB devices are allowed to be low-speed (such > devices can op

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 9, 2022, at 1:02 PM, Tomasz Moń wrote: > The same as why URB level captures are confusing. Maybe not to the same > level as that would be just a single byte (and the URB metadata > contains way more information), but it would still raise the questions > like "where in

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, 2022-05-09 at 13:19 -0700, Guy Harris wrote: > On May 9, 2022, at 1:02 PM, Tomasz Moń wrote: > > > The same as why URB level captures are confusing. Maybe not to the > > same > > level as that would be just a single byte (and the URB metadata > > contains way more in

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 9, 2022, at 9:41 PM, Tomasz Moń wrote: > On Mon, 2022-05-09 at 13:19 -0700, Guy Harris wrote: >> On May 9, 2022, at 1:02 PM, Tomasz Moń wrote: >> >>> "Why this doesn't match all the documents on USB that I have >>> read?". >> >> What is the "this" that wouldn't mat

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Tue, May 10, 2022 at 6:57 AM Guy Harris wrote: > On May 9, 2022, at 9:41 PM, Tomasz Moń wrote: > > Also Wireshark would have to show "USB Full/Low speed capture" section with > > only the single byte denoting > > full or low speed, followed by "USB Link Layer" (as shown

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Guy Harris via tcpdump-workers
--- Begin Message --- On May 9, 2022, at 10:05 PM, Tomasz Moń wrote: > On Tue, May 10, 2022 at 6:57 AM Guy Harris wrote: >> On May 9, 2022, at 9:41 PM, Tomasz Moń wrote: >>> Also Wireshark would have to show "USB Full/Low speed capture" section with >>> only the single byte denoting >>> full o

Re: [tcpdump-workers] Speed specific Link-Layer Header Types for USB 2.0

2022-05-09 Thread Tomasz Moń via tcpdump-workers
--- Begin Message --- On Mon, May 9, 2022 at 10:17 PM Guy Harris wrote: > On May 9, 2022, at 12:31 PM, Tomasz Moń wrote: > > There is no such thing as "low-speed bus" because low-speed is only > > allowed for non-hub devices. USB hosts and hubs *must* support atleast > > full and high speed. USB