From owner-freebsd-net@freebsd.org Tue Jan 5 07:02:50 2021 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 250EB4DAE86 for ; Tue, 5 Jan 2021 07:02:50 +0000 (UTC) (envelope-from shamaz.mazum@gmail.com) Received: from mail-oi1-x236.google.com (mail-oi1-x236.google.com [IPv6:2607:f8b0:4864:20::236]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4D93NT32wHz3L45 for ; Tue, 5 Jan 2021 07:02:49 +0000 (UTC) (envelope-from shamaz.mazum@gmail.com) Received: by mail-oi1-x236.google.com with SMTP id q205so34975983oig.13 for ; Mon, 04 Jan 2021 23:02:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=+z7hQ/hiUdp73+YSIjwfT4ewYJuVcXMVqpGPulkQxfc=; b=Oi9FQ3iUmbO+peX0Vakt5wYA0dU151lW984AHns+a1kUC281MFKcfd3caY4H1MaC0E jxvwTBSkBEIjohu5mHfebiq14bxfGhl2jmG141WRpibLPExO18P3DKvr1YEOGswt2ZiL XS4zGhpktJzNrrSTZX1R5tV5L4r6umNXDXADVqISLtzFPOw1RNU6Sj7DTTvwdW7zAhKV lSr4TV1e5rwWYSr7CSdIcOlxnx4h9fXkMg8C0BVjquY/Aa81xcrsMfYzYuSelqg1eMPf XyMyCfEGH5og1pvhyrDf0Ajzmu5FeZ4S3nc68NLlVEPKIoseld7qiJFI6fVebyiYfdkM 5mMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=+z7hQ/hiUdp73+YSIjwfT4ewYJuVcXMVqpGPulkQxfc=; b=mlwvpLDo9nJnE/SUryMlPsXqw+ijM7sPkGlGoeD1M11/ZGXtJiPxYkxXZCIecRR+Ye JkmGD8H5rKIDQS3CpcjxzWOW+0klnFRBvXmGHx3HK/E7YdI3zE6S3aFQHhcZbRqZxk66 yVvJ4geOQ52i55EjDZiPo7hoSte8PhGP+LP7Dusy1zGowuBXfrE5ShTiXxeitmOP/yVy AATROkjOOMgm95qSvgw8AF1Gt4pn5Msce+d63I4q+VS12jOKRoycNMPwtYUxRo3fhtZQ jW0u3piehagibYCkWzaIAIHt88kfrVbFlMeyMHaf03j87IbYY7b0MGZhQlNB+YeUemFm WVgA== X-Gm-Message-State: AOAM532U5ktljPQFe7PhhLLpS5B1MoKPFy4xhgeMhz6kq/gXF+z2JHfS 2b7KbfTHz+yMOCfbQg5bEAl9OAz5thVWsbZXZrmotehKJe3PiA== X-Google-Smtp-Source: ABdhPJzDUtwmwJ9GaRlXPmuIxIMCP8/10SgYwVicf/NSwyvjnoT7SPHEa2+yybZuQmHxQ5yD4njNSNDhlwwI1dFlPGo= X-Received: by 2002:a54:400e:: with SMTP id x14mr1791202oie.21.1609830168114; Mon, 04 Jan 2021 23:02:48 -0800 (PST) MIME-Version: 1.0 From: Vasily Postnicov Date: Tue, 5 Jan 2021 10:02:37 +0300 Message-ID: Subject: DNS using Name Service Switch module and Casper To: freebsd-net@freebsd.org X-Rspamd-Queue-Id: 4D93NT32wHz3L45 X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=Oi9FQ3iU; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of shamazmazum@gmail.com designates 2607:f8b0:4864:20::236 as permitted sender) smtp.mailfrom=shamazmazum@gmail.com X-Spamd-Result: default: False [-4.00 / 15.00]; R_SPF_ALLOW(-0.20)[+ip6:2607:f8b0:4000::/36:c]; FREEMAIL_FROM(0.00)[gmail.com]; TO_DN_NONE(0.00)[]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; NEURAL_HAM_SHORT(-1.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RBL_DBL_DONT_QUERY_IPS(0.00)[2607:f8b0:4864:20::236:from]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; TAGGED_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-net@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[2607:f8b0:4864:20::236:from:127.0.2.255]; RCVD_IN_DNSWL_NONE(0.00)[2607:f8b0:4864:20::236:from]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-net] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.34 X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Jan 2021 07:02:50 -0000 Hello. I wrote a simple daemon called ZeroDNS which provides functionality similar to multicast DNS, namely it discovers other participating machines over the LAN and stores their hostname and IPv4 address pairs. Here is a NSS module which allows the system to use information from that daemon: https://github.com/shamazmazum/nss-zero-dns You need to modify /etc/nsswitch.conf, changing the line 'hosts: files dns' to 'hosts: files dns zerodns'. It all works on FreeBSD 12.2-RELEASE, but sometimes not on 13.0-CURRENT. For example, ping(8) just blocks when trying to ping a host whose name is resolvable with ZeroDNS. Turns out that programs built with casper support (like ping(8) and some others) stop working with my NSS module (they just block trying to resolve the name). Is there some kind of manual on how to write casper-compatible NSS modules?