From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/1569 Path: news.gmane.org!not-for-mail From: "Arvid E. Picciani" Newsgroups: gmane.linux.lib.musl.general Subject: Re: Design for extensible =?UTF-8?Q?passwd=5B/shadow=3F=5D?= =?UTF-8?Q?=20db=20support?= Date: Mon, 13 Aug 2012 22:14:00 +0200 Message-ID: <10bce7f58679d9e976e3ddf95d11d995@exys.org> References: <20120812053802.GA10971@brightrain.aerifal.cx> <20120812205643.GT27715@brightrain.aerifal.cx> <20120813135048.GX27715@brightrain.aerifal.cx> <20120813192833.GY27715@brightrain.aerifal.cx> <58cedf3a99d2a7eb61d861abdb8c1840@exys.org> <20120813195032.GZ27715@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1344888864 27542 80.91.229.3 (13 Aug 2012 20:14:24 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Mon, 13 Aug 2012 20:14:24 +0000 (UTC) To: Original-X-From: musl-return-1570-gllmg-musl=m.gmane.org@lists.openwall.com Mon Aug 13 22:14:25 2012 Return-path: Envelope-to: gllmg-musl@plane.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1T111l-0006jF-Pm for gllmg-musl@plane.gmane.org; Mon, 13 Aug 2012 22:14:17 +0200 Original-Received: (qmail 13500 invoked by uid 550); 13 Aug 2012 20:14:16 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 13492 invoked from network); 13 Aug 2012 20:14:16 -0000 In-Reply-To: <20120813195032.GZ27715@brightrain.aerifal.cx> X-Sender: aep@exys.org User-Agent: Roundcube Webmail/0.5.4 Xref: news.gmane.org gmane.linux.lib.musl.general:1569 Archived-At: On Mon, 13 Aug 2012 15:50:32 -0400, Rich Felker wrote: > [..] parse the entire /etc/passwd file every time it's called hm yeah. This stuff is all fairly ugly, which is why i hoped to get it out of libc into a high level construct that can be replaced with system specific parts. > glibc has a solution for this problem in the form of nscd The libc daemon from hell :/ A proxy daemon requires much more care and policy. What happens when it times out, or responses are invalid, how do i do balancing, ... "Falling back on local database" isn't graceful degradation. It requires that you anticipate the situation and make sure there is a fallback user in the passwd for maintenance. Then security is a whole new topic. Who can access the daemon, what is the retry policy, how do i handle linux namespaces, and containers... So many things to deal with... > The problem with this is when you copy or static-linked busybox onto > a > system that needs non-flat-file user lookups, and it fails to work > right... Yes. They're incompatible. I don't see why this is a problem, but then again i don't work on desktop systems at all. They're not interesting systems, because resources are so inexpensive. > I don't think removing ~50 lines of passwd entry lookup code would be > of much benefit for cutting down size, no, not at all. But being able to ignore ancient posix and go for something that gets us to the product faster is something pretty valuable for me. Let's take the fairly visible example of musl-android: it doesn't have /etc/passwd, so i already have to downstream patch musl. A proxy does not help me, because the fallback is still on /etc/passwd. Again, i can only emphasize that these things are so fundamentally setup dependent, that i think putting this in libc was a bad choice back then. -- Arvid E. Picciani