| README (214518) | README (235426) |
|---|---|
| 1@(#) $Header: /tcpdump/master/libpcap/README,v 1.34 2008-12-14 19:44:14 guy Exp $ (LBL) 2 3LIBPCAP 1.x.y 4 5www.tcpdump.org 6 7Please send inquiries/comments/reports to: 8 tcpdump-workers@lists.tcpdump.org --- 49 unchanged lines hidden (view full) --- 58Although most packet capture interfaces support in-kernel filtering, 59libpcap utilizes in-kernel filtering only for the BPF interface. 60On systems that don't have BPF, all packets are read into user-space 61and the BPF filters are evaluated in the libpcap library, incurring 62added overhead (especially, for selective filters). Ideally, libpcap 63would translate BPF filters into a filter program that is compatible 64with the underlying kernel subsystem, but this is not yet implemented. 65 | 1@(#) $Header: /tcpdump/master/libpcap/README,v 1.34 2008-12-14 19:44:14 guy Exp $ (LBL) 2 3LIBPCAP 1.x.y 4 5www.tcpdump.org 6 7Please send inquiries/comments/reports to: 8 tcpdump-workers@lists.tcpdump.org --- 49 unchanged lines hidden (view full) --- 58Although most packet capture interfaces support in-kernel filtering, 59libpcap utilizes in-kernel filtering only for the BPF interface. 60On systems that don't have BPF, all packets are read into user-space 61and the BPF filters are evaluated in the libpcap library, incurring 62added overhead (especially, for selective filters). Ideally, libpcap 63would translate BPF filters into a filter program that is compatible 64with the underlying kernel subsystem, but this is not yet implemented. 65 |
| 66BPF is standard in 4.4BSD, BSD/OS, NetBSD, FreeBSD, and OpenBSD. DEC 67OSF/1/Digital UNIX/Tru64 UNIX uses the packetfilter interface but has 68been extended to accept BPF filters (which libpcap utilizes). Also, you 69can add BPF filter support to Ultrix using the kernel source and/or 70object patches available in: | 66BPF is standard in 4.4BSD, BSD/OS, NetBSD, FreeBSD, OpenBSD, DragonFly 67BSD, and Mac OS X; an older, modified and undocumented version is 68standard in AIX. {DEC OSF/1, Digital UNIX, Tru64 UNIX} uses the 69packetfilter interface but has been extended to accept BPF filters 70(which libpcap utilizes). Also, you can add BPF filter support to 71Ultrix using the kernel source and/or object patches available in: |
| 71 | 72 |
| 72 ftp://gatekeeper.dec.com/pub/DEC/net/bpfext42.tar.Z. | 73 http://www.tcpdump.org/other/bpfext42.tar.Z |
| 73 74Linux, in the 2.2 kernel and later kernels, has a "Socket Filter" 75mechanism that accepts BPF filters; see the README.linux file for 76information on configuring that option. 77 78Note to Linux distributions and *BSD systems that include libpcap: 79 80There's now a rule to make a shared library, which should work on Linux --- 24 unchanged lines hidden --- | 74 75Linux, in the 2.2 kernel and later kernels, has a "Socket Filter" 76mechanism that accepts BPF filters; see the README.linux file for 77information on configuring that option. 78 79Note to Linux distributions and *BSD systems that include libpcap: 80 81There's now a rule to make a shared library, which should work on Linux --- 24 unchanged lines hidden --- |