From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" Newsgroups: gmane.emacs.bugs Subject: bug#58520: Persistent failure to DNS-lookup hostname Date: Sun, 17 Dec 2023 18:27:10 -0500 Message-ID: References: <875y2j9sm6.fsf@gmail.com> <87r0l6fzdv.fsf@gmail.com> <87edh6fdvo.fsf@gmail.com> <87fs09uf7z.fsf@gmail.com> Reply-To: Stefan Monnier Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="36077"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Cc: 58520@debbugs.gnu.org, Paul Eggert To: Visuwesh Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Mon Dec 18 00:28:20 2023 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1rF0YU-0009Ck-Kx for geb-bug-gnu-emacs@m.gmane-mx.org; Mon, 18 Dec 2023 00:28:18 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rF0YD-0007cv-Gp; Sun, 17 Dec 2023 18:28:01 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rF0YC-0007cc-Fr for bug-gnu-emacs@gnu.org; Sun, 17 Dec 2023 18:28:00 -0500 Original-Received: from debbugs.gnu.org ([2001:470:142:5::43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1rF0YC-00009D-7Q for bug-gnu-emacs@gnu.org; Sun, 17 Dec 2023 18:28:00 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1rF0YD-0003p5-Mf for bug-gnu-emacs@gnu.org; Sun, 17 Dec 2023 18:28:01 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sun, 17 Dec 2023 23:28:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 58520 X-GNU-PR-Package: emacs Original-Received: via spool by 58520-submit@debbugs.gnu.org id=B58520.170285563914643 (code B ref 58520); Sun, 17 Dec 2023 23:28:01 +0000 Original-Received: (at 58520) by debbugs.gnu.org; 17 Dec 2023 23:27:19 +0000 Original-Received: from localhost ([127.0.0.1]:59168 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1rF0XX-0003o6-3Q for submit@debbugs.gnu.org; Sun, 17 Dec 2023 18:27:19 -0500 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:15073) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1rF0XU-0003nt-HN for 58520@debbugs.gnu.org; Sun, 17 Dec 2023 18:27:17 -0500 Original-Received: from pmg2.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id 7DEAB80D06; Sun, 17 Dec 2023 18:27:09 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1702855628; bh=NG2Ry5yBZBafGMWIaqUVPhLWPEqgmlc50f/RfuILK14=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=knKmhU134SZ8WZGzWmNfjAkw6NVmW4klrtGBJewH570Ki0YJ/FQppOfQwsF8SXPdD ijOVoFbapbzG0TmCraoxAvhHdYl+t4ka44rowRrGzJCbYEKqOVFKBwZIkIZ2VxRL9c q3BqYrGtj/a/n7GKVF2JVnYBLHYoRQ90x3O29G/8OhpD8RqCATtG248ZRBiE0+dImv yELzTZ0c1VEhKdxPwlMXKmFjw6cBiCoZxRpE4KulvTHJ986I8YX/2uzqBJZGLd+WzI +7t0MMLrOp53M9B4y1dratT2+RPd1ZQfgj15Uw7KuqoRxU/IWZW+9GjKrfIuT8xyLy gzQMNXWxL9C+w== Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg2.iro.umontreal.ca (Proxmox) with ESMTP id 2625480CDE; Sun, 17 Dec 2023 18:27:08 -0500 (EST) Original-Received: from alfajor (65-110-221-238.cpe.pppoe.ca [65.110.221.238]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id EFF4D120DFD; Sun, 17 Dec 2023 18:27:07 -0500 (EST) In-Reply-To: <87fs09uf7z.fsf@gmail.com> (Visuwesh's message of "Mon, 11 Dec 2023 17:24:24 +0530") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:276447 Archived-At: > P.S. It would be nice to have that patch that you mentioned that added a > function that fixes the broken requests. I use the patch below. When Emacs gets into this weird state, I do `M-: (res-init) RET` after which I can connect again. Stefan diff --git a/src/process.c b/src/process.c index 8bc922ab509..56773fe192e 100644 --- a/src/process.c +++ b/src/process.c @@ -3770,6 +3769,33 @@ connect_network_socket (Lisp_Object proc, Lisp_Object addrinfos, unbind_to (count, Qnil); } +/* FIXME: Persistent DNS lookup errors!! + * Madhu suggests calling `res_init`, but that doesn't + * seem to exist any more in current glibc. + * Robert Pluim suggests to use + * + * tcpdump -i any -n udp and port 53 + * + * to try and see what requests are being sent out (if any) to where. + * Eli suggests checking systemwide DNS caches, pointing to: + * + * https://devconnected.com/how-to-flush-dns-cache-on-linux/ + * https://beebom.com/how-flush-dns-cache-linux/ + * https://linuxize.com/post/how-to-clear-the-dns-cache/ + * + * Relevant: + * https://sourceware.org/bugzilla/show_bug.cgi?id=984 + */ + +#include + +DEFUN ("res-init", Fres_init, Sres_init, 0, 0, 0, doc: /* Run `res_init`. */) + (void) +{ + res_init (); + return Qnil; +} + /* Create a network stream/datagram client/server process. Treated exactly like a normal process when reading and writing. Primary differences are in status display and process deletion. A network @@ -8821,6 +8849,7 @@ syms_of_process (void) defsubr (&Sserial_process_configure); defsubr (&Smake_serial_process); defsubr (&Sset_network_process_option); + defsubr (&Sres_init); defsubr (&Smake_network_process); defsubr (&Sformat_network_address); defsubr (&Snetwork_lookup_address_info);