tcpdump mailing list archives
Re: BPF Extended: addressing BPF's shortcomings
From: "Paul \"LeoNerd\" Evans" <leonerd () leonerd org uk>
Date: Thu, 11 Jun 2015 14:33:52 +0100
On Thu, 11 Jun 2015 20:12:00 +1000 Darren Reed <darrenr () netbsd org> wrote:
2) A few more AD constants added to the Linux "auxdata" area, giving information about the transport layer.Can you please expand on this?
See the SKF_NET_OFF and SKF_LL_OFF constants. I wanted to simply add another, SKF_TRANS_OFF This would give an offset into a virtual view of the "transport" layer; i.e. the start of the TCP/UDP/whatever header, regardless where it starts in the packet. Now, filtering for a given TCP port only needs to compare the value of SKF_AD_TRANSPORT (which we'd also have to add), and then look at certain indexes into SKF_TRANS_OFF; it doesn't have to *find* the TCP header at all, doesn't care if it's IPv4 or IPv6 or whatever... -- Paul "LeoNerd" Evans leonerd () leonerd org uk http://www.leonerd.org.uk/ | https://metacpan.org/author/PEVANS _______________________________________________ tcpdump-workers mailing list tcpdump-workers () lists tcpdump org https://lists.sandelman.ca/mailman/listinfo/tcpdump-workers
Current thread:
- BPF Extended: addressing BPF's shortcomings Darren Reed (Jun 10)
- Re: BPF Extended: addressing BPF's shortcomings Paul "LeoNerd" Evans (Jun 10)
- Re: BPF Extended: addressing BPF's shortcomings Darren Reed (Jun 11)
- Re: BPF Extended: addressing BPF's shortcomings Paul "LeoNerd" Evans (Jun 11)
- Re: BPF Extended: addressing BPF's shortcomings Michael Richardson (Jun 11)
- Re: BPF Extended: addressing BPF's shortcomings Darren Reed (Jun 11)
- Re: BPF Extended: addressing BPF's shortcomings Paul "LeoNerd" Evans (Jun 10)
- Re: BPF Extended: addressing BPF's shortcomings Mindaugas Rasiukevicius (Jun 10)
- Re: BPF Extended: addressing BPF's shortcomings Guy Harris (Jun 10)
- Re: BPF Extended: addressing BPF's shortcomings Paul "LeoNerd" Evans (Jun 11)
- Re: BPF Extended: addressing BPF's shortcomings Darren Reed (Jun 11)
- Re: BPF Extended: addressing BPF's shortcomings Paul "LeoNerd" Evans (Jun 11)
- Re: BPF Extended: addressing BPF's shortcomings Guy Harris (Jun 10)