[tcpdump-workers] Add Sigfox support to libpcap
Hi all, Currently, I am extending a Sigfox demodulator https://github.com/Jeija/renard-phy. I already added a function to export the demodulated frames. During my work, I ran into a problem with the Linktype. Sigfox works directly on layer 2 to avoid misinterpretation of my packets I used one of the user Linktypes (DLT_USER0). Would it be possible to reserve a Linktype for Sigfox? I took a quick look at libpcap would there be anything else to do than to add another define to pcap-common.c? Greetings Jannis ___ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
Re: [tcpdump-workers] Add Sigfox support to libpcap
On Jan 8, 2019, at 9:15 AM, wrote: > Currently, I am extending a Sigfox demodulator > https://github.com/Jeija/renard-phy. > I already added a function to export the demodulated frames. During my work, > I ran into a problem with the Linktype. Sigfox works directly on layer 2 to > avoid misinterpretation of my packets I used one of the user Linktypes > (DLT_USER0). > > Would it be possible to reserve a Linktype for Sigfox? > I took a quick look at libpcap would there be anything else to do than to > add another define to pcap-common.c? There's "adding a new link-layer header type for pcap and pcapng files" and there's "adding a module to libpcap that can capture from a new capture source". "reserve a Linktype for Sigfox" is the former; "add a libpcap module that controls a software-defined radio, demodulates Sigfox signals, and supplies packets to callers, so that any program that uses libpcap, such as tcpdump or Wireshark, can directly capture Sigfox packets" is the latter. If you're talking about the former, it would be possible, but the first step would be to provide a detailed description of the packets. See the second item in the bulleted list at the top of http://www.tcpdump.org/linktypes.html for more details on the process, as well as https://github.com/the-tcpdump-group/libpcap/blob/master/doc/DLT_ALLOCATE_HOWTO.md ___ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
Re: [tcpdump-workers] Add Sigfox support to libpcap
Thanks for the quick reply. I am no radio guy so implementing a module for capturing is out of scope for me. Such a module could be implemented by another person (I am not the owner of the referenced project). A protocol specification can be found here https://github.com/Jeija/renard-spec/releases I would like to specify a Linktype at first. -Ursprüngliche Mitteilung- Von: Guy Harris An: jannisohms Cc: tcpdump-workers Verschickt: Di, 8. Jan. 2019 19:54 Betreff: Re: [tcpdump-workers] Add Sigfox support to libpcap On Jan 8, 2019, at 9:15 AM, wrote: > Currently, I am extending a Sigfox demodulator > https://github.com/Jeija/renard-phy. > I already added a function to export the demodulated frames. During my work, > I ran into a problem with the Linktype. Sigfox works directly on layer 2 to > avoid misinterpretation of my packets I used one of the user Linktypes > (DLT_USER0). > > Would it be possible to reserve a Linktype for Sigfox? > I took a quick look at libpcap would there be anything else to do than to > add another define to pcap-common.c? There's "adding a new link-layer header type for pcap and pcapng files" and there's "adding a module to libpcap that can capture from a new capture source". "reserve a Linktype for Sigfox" is the former; "add a libpcap module that controls a software-defined radio, demodulates Sigfox signals, and supplies packets to callers, so that any program that uses libpcap, such as tcpdump or Wireshark, can directly capture Sigfox packets" is the latter. If you're talking about the former, it would be possible, but the first step would be to provide a detailed description of the packets. See the second item in the bulleted list at the top of http://www.tcpdump.org/linktypes.html for more details on the process, as well as https://github.com/the-tcpdump-group/libpcap/blob/master/doc/DLT_ALLOCATE_HOWTO.md ___ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
Re: [tcpdump-workers] Add Sigfox support to libpcap
On Jan 8, 2019, at 11:20 AM, wrote: > A protocol specification can be found here > https://github.com/Jeija/renard-spec/releases OK, so: 1) Would the link-layer header include any radio metadata? For 802.11, there are various forms of radio metadata headers, such as the radiotap header: http://www.radiotap.org If so, what would the format of the radio metadata be? 2) The 2.2.2 "Implementation by Sigfox" section of the spec shows, on page 14, a frame structure. In the captures, is the first byte of frame data (following the radio metadata, if there is radio metadata, or at the beginning of the packet, if there is no radio metadata), the first byte of the Preamble/Type? 3) Is the CRC-16 included with the frames? ___ tcpdump-workers mailing list tcpdump-workers@lists.tcpdump.org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
