Wireshark mailing list archives
Re: usbmon: size of different fields?
From: "Maynard, Chris" <Christopher.Maynard () GTECH COM>
Date: Tue, 9 Nov 2010 11:25:11 -0500
Not sure why I don't see this message posted on gmane? Anyway, I see you received a few responses already elsewhere: -> http://lkml.org/lkml/2010/11/9/243 -> http://www.spinics.net/lists/linux-usb/msg38480.html But I don't think those responses are technically correct. With the C standard, there are no guarantees except for relative sizes, ie., char <= short <= int <= long, although if the OS is POSIX-compliant, then you can sleep well at night knowing CHAR_BIT is defined as 8 in <limits.h>. But there's no guarantee that every platform is POSIX-compliant or that the char size is guaranteed to be 8 bits on non-POSIX-conforming platforms, although I can't imagine that Wireshark runs today on any platform where that isn't the case. As for int, I suspect that most platforms have 32-bit ints, but again, there are no guarantees. - Chris P.S. The endian-ness is not an issue because of the libpcap header's magic number. -----Original Message----- From: wireshark-dev-bounces () wireshark org [mailto:wireshark-dev-bounces () wireshark org] On Behalf Of Németh Márton Sent: Tuesday, November 09, 2010 1:41 AM To: linux-usb () vger kernel org Cc: Developer support list for Wireshark; LKML Subject: [Wireshark-dev] usbmon: size of different fields? Hi, I'm looking at the struct mon_bin_hdr and struct mon_bin_isodesc in file http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=drivers/usb/mon/mon_bin.c;h=44cb37b5a4dc1f9b27075e3db5346b9ebe307b22;hb=HEAD As far as I understand u64, s64, u32 and s32 have always fixed bit lengths. What about "unsigned char", "char", "unsigned int" and "int"? May their size in bits differ in different architecture? I'm asking this because I was dealing with the USB packet dissectors for Wireshark and it is possible to capture the USB traffic on one computer and then transfer the file to another computer. Márton Németh CONFIDENTIALITY NOTICE: The contents of this email are confidential and for the exclusive use of the intended recipient. If you receive this email in error, please delete it from your system immediately and notify us either by email, telephone or fax. You should not copy, forward, or otherwise disclose the content of the email. ___________________________________________________________________________ Sent via: Wireshark-dev mailing list <wireshark-dev () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-dev Unsubscribe: https://wireshark.org/mailman/options/wireshark-dev mailto:wireshark-dev-request () wireshark org?subject=unsubscribe
Current thread:
- usbmon: size of different fields? Németh Márton (Nov 08)
- Re: usbmon: size of different fields? Maynard, Chris (Nov 09)
- Re: usbmon: size of different fields? Guy Harris (Nov 09)
- Re: usbmon: size of different fields? Pete Zaitcev (Nov 11)
- Re: usbmon: size of different fields? Németh Márton (Nov 09)
- Re: usbmon: size of different fields? Guy Harris (Nov 09)
- Re: usbmon: size of different fields? Pete Zaitcev (Nov 11)
- Re: usbmon: size of different fields? Guy Harris (Nov 10)
- Re: usbmon: size of different fields? Németh Márton (Nov 09)
- Re: usbmon: size of different fields? Maynard, Chris (Nov 09)