Date: Wed, 25 Apr 2018 20:10:28 +0530 From: Reshad Patuck <reshadpatuck1@gmail.com> To: Eugene Grosbein <eugen@grosbein.net>,freebsd-net@freebsd.org Subject: Re: [netgraph] ng_bpf filter large list of IP addresses Message-ID: <EFFB436D-3A09-4D91-88F1-D641993BBED3@gmail.com> In-Reply-To: <5AC118E8.1020800@grosbein.net> References: <D4E00F05-F64D-4446-A572-E1A0E06B2C47@gmail.com> <5AC118E8.1020800@grosbein.net>
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Hey, I have tried to write some c code to add a bpf filter to my ng_bpf node, but its just segfaulting. My c is not good enough to debug this. What baffles me is that when I load a filter for 250 IP addresses using the command in this link https://paste.ee/d/BHOoG/3 it loads fine. If I use 'ngctl -f' with the file in this link https://paste.ee/d/BHOoG/2 I get an error saying 'ngctl: send msg: Invalid argument; ngctl: line 1: error in file' The BPF filter and arguments in that command are exactly the same. My problem is that I need to load thousands of IP addresses in a blocking filter, which I am not able to pass over a command line because the list becomes too long and I hit either the kern.argmax limit of 262144 bytes or the LINE_MAX (2048) for ngctl. I can share the c code I am using to attempt this using NgSendAsciiMsg(), but I don't think that would be too useful. I am open to hiring someone as a consultant to help write a program/script preferably in python or c to accomplish this. If anyone can help with this or knows someone who can, please feel free to contact me. Best regards, Reshad On 1 April 2018 11:07:44 PM IST, Eugene Grosbein <eugen@grosbein.net> wrote: >31.03.2018 20:46, Reshad Patuck wrote: > >> Please let me know what I am doing wrong with the ngctl config file >and >> if there is another way, maybe something more direct to load a binary >bpf filter directly into ng_bpf. > >There is also netgraph(3) - Netgraph User Library. You can use it >within your C code >to send binary or text (ASCII) control messages directly to ng_bpf >without limitations >of ngctl's own parser. > >You can get an example of NgSendAsciiMsg() usage in ngctl's sources: > >https://svnweb.freebsd.org/base/head/usr.sbin/ngctl/msg.c?view=markup
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