Gentoo Archives: gentoo-user

From: Nils Holland <nhg@×××××.org>
To: gentoo-user@l.g.o
Subject: [gentoo-user] PAM and utmp
Date: Fri, 17 Feb 2012 21:39:55
Message-Id: 20120217213735.GA3952@eee1215n.fritz.box
1 Hi folks,
2
3 well, I did some searches on this already, but without success, so I
4 thought I'd ask here. Following issue:
5
6 I have the strong feeling that my ~x86 Gentoo box no longer seems to
7 record "local" logins into /var/run/utmp. When I use screen or login via
8 ssh, everything works fine, but I can do millions of local, non-X11
9 plain vanilla terminal logins without ever seeing anything when running
10 "who" or "w". And I have the feeling that this used to work in the past.
11
12 Now, what do I know, I tried to trace the problem down a bit. My
13 /var/run/utmp seems absolutely fine structure- and permission-wise. So I
14 had a look at the sources of /bin/login, because I believed that this
15 little guy actually writes to utmp entry when I login. That assumption
16 seemed to be wrong, however, since in cases where PAM is used (which is
17 the case here), /bin/login no longer seems to be responsible for that,
18 but instead it is handled by PAM. At least it looks so in the source.
19
20 Interestingly, I found a man page for the PAM module "pam_lastlog.so" on
21 the web which states that this modul would create the utmp entry. The
22 pam_lastlog man page on my local system only mentions /var/log/lastlog
23 and wtmp - nothing about utmp. So ... I have pam_lastlog in use here but
24 it in fact doesn't seem to make a difference utmp-wise. Is it possible
25 that the module *used* to do utmp stuff but no longer does today?
26
27 Some further searching revealed another PAM module called
28 "pam_loginuid", which, according to its man page, "sets the loginuid
29 process attribute for the process that was authenticated" and should be
30 used for "entry point applications like login". Aha. Tried that. Didn't
31 seem to do anything. Now I really wonder who on earth is really
32 responsible to record my login this days. ;-)
33
34 Am I the only thing seeing this, or can somebody confirm this? Any hints
35 would be greatly appreciated!
36
37 Thanks and greetings,
38 Nils
39
40
41 --
42 Nils Holland * Ti Systems, Wunstorf-Luthe (Germany)
43 Our Gentoo mirror: http://rush.tisys.org/ (IPv4 + IPv6)
44 Powered by GNU/Linux since 1998

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Re: [gentoo-user] PAM and utmp Nils Holland <nhg@×××××.org>