From owner-freebsd-net@freebsd.org Mon Jul 29 06:04:42 2019 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id A4690BE405 for ; Mon, 29 Jul 2019 06:04:42 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [IPv6:2a01:4f8:c2c:26d8::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 0F8238FD86 for ; Mon, 29 Jul 2019 06:04:31 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [IPv6:2a03:3100:c:13:0:0:0:5]) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id x6T64GVL010970 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Jul 2019 06:04:23 GMT (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: yuri@rawbw.com Received: from [10.58.0.4] ([10.58.0.4]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id x6T64B3S003468 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Mon, 29 Jul 2019 13:04:11 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: Is there an way for a program to know when the list of network interfaces has changed (without rescanning them)? To: Yuri , "freebsd-net@freebsd.org" References: From: Eugene Grosbein Message-ID: <4c60eb9c-2947-1d2b-3c65-8b87201a0487@grosbein.net> Date: Mon, 29 Jul 2019 13:04:05 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=0.3 required=5.0 tests=BAYES_00,LOCAL_FROM, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.2 X-Spam-Report: * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record * -0.0 SPF_PASS SPF: sender matches SPF record * 2.6 LOCAL_FROM From my domains X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on hz.grosbein.net X-Rspamd-Queue-Id: 0F8238FD86 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; spf=permerror (mx1.freebsd.org: domain of eugen@grosbein.net uses mechanism not recognized by this client) smtp.mailfrom=eugen@grosbein.net X-Spamd-Result: default: False [-2.17 / 15.00]; ARC_NA(0.00)[]; TO_DN_EQ_ADDR_SOME(0.00)[]; MX_INVALID(0.50)[greylisted]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; NEURAL_HAM_MEDIUM(-0.93)[-0.927,0]; NEURAL_HAM_LONG(-0.99)[-0.992,0]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; DMARC_NA(0.00)[grosbein.net]; RCVD_COUNT_THREE(0.00)[3]; TO_MATCH_ENVRCPT_SOME(0.00)[]; R_SPF_PERMFAIL(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_SHORT(-0.90)[-0.901,0]; IP_SCORE(-0.75)[ipnet: 2a01:4f8::/29(-1.93), asn: 24940(-1.82), country: DE(-0.01)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; SUBJECT_ENDS_QUESTION(1.00)[]; ASN(0.00)[asn:24940, ipnet:2a01:4f8::/29, country:DE]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Jul 2019 06:04:42 -0000 29.07.2019 12:35, Yuri wrote: > I am asking because wireshark doesn't sense the interface list changes, and it just always shows the list from the time it was launched . There is a way as we have devd(8) reading kernel-generated events and running commands in response. Look at default /etc/devd.conf rules for example: notify 0 { match "system" "IFNET"; match "subsystem" "!(usbus|wlan)[0-9]+"; match "type" "ATTACH"; action "/etc/pccard_ether $subsystem start"; }; Quoting devd(8) manual page: > Since devctl(4) allows only one active reader, devd multiplexes it, > forwarding all events to any number of connected clients. Clients > connect by opening the SOCK_SEQPACKET UNIX domain socket at > /var/run/devd.seqpacket.pipe. We have bsnmpd(1) in base system and its module usr.sbin/bsnmpd/modules/snmp_hostres acting as client of devd, for example.