tcpdump mailing list archives
Re: [BUG] pcap-usb-linux.c
From: Guy Harris <guy () alum mit edu>
Date: Mon, 24 Nov 2008 12:10:58 -0800
On Oct 29, 2008, at 7:38 PM, Jean-Louis wrote:
in accordance with usbmon.txt in "mmap mode" the data is at &mmap_area[vec[i]] + 64; rather than &mmap_area[vec[i]] + 48; with mmap ther'is 16Byte filled with 0 first to the real data...so if i.e. I have caplen = 18Byte, in file.pcap I have 16Byte with garbage (0x00) and only 2Byte with real data other 16Byte of real data is lost.the mmap mode is *default* with kernel >= 2.6.25-rc8-mm1I'm newbie with libpcap and I don't know how I can fix that without degrading performance
The only way to fix that without doing a lot of copying would be to add a new DLT_ value for Linux mmapped access, with the USB header defined to include the padding (and change apps that handle USB captures to handle the new DLT_ value). -
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Current thread:
- Re: [Patch 4-4] pcap-usb-linux.c, (continued)
- Re: [Patch 4-4] pcap-usb-linux.c Jean-Louis (Oct 29)
- Re: [BUG] pcap-usb-linux.c Jean-Louis (Oct 29)
- Re: [Patch/Workaround?] pcap-usb-linux.c Jean-Louis (Oct 30)
- Re: [Patch/Workaround?] pcap-usb-linux.c Tyson Key (Oct 30)
- Re: [Patch/Workaround?] pcap-usb-linux.c Jean-Louis (Oct 30)
- Re: [Patch/Workaround?] pcap-usb-linux.c Tyson Key (Oct 30)
- Re: [Patch/Workaround?] pcap-usb-linux.c Jean-Louis (Oct 30)
- Re: [Patch/Workaround?] pcap-usb-linux.c Jean-Louis (Oct 30)
- Re: [Patch/Workaround?] pcap-usb-linux.c Tyson Key (Oct 30)
- Re: [Patch/Workaround?] pcap-usb-linux.c Guy Harris (Dec 23)
- Re: [BUG] pcap-usb-linux.c Guy Harris (Nov 24)
- Re: [BUG] pcap-usb-linux.c Tyson Key (Nov 24)
- Re: [BUG] pcap-usb-linux.c Guy Harris (Nov 25)
- Re: [BUG] pcap-usb-linux.c Jean-Louis (Nov 27)
- Re: [BUG] pcap-usb-linux.c Jean-Louis (Nov 27)
- Re: [BUG] pcap-usb-linux.c Guy Harris (Dec 23)
- Re: [BUG] pcap-usb-linux.c Guy Harris (Dec 23)
- Re: [Patch 4-4] pcap-usb-linux.c Guy Harris (Nov 24)
- Re: [Patch 3-4] pcap-usb-linux.c Guy Harris (Nov 24)
- Re: [Patch 3-4] pcap-usb-linux.c Jean-Louis (Nov 27)
- Re: [Patch 2-4] pcap-usb-linux.c Guy Harris (Nov 24)