[Bug 558878] New: bad default ^host: entry in /etc/nsswitch.conf
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c0 Summary: bad default ^host: entry in /etc/nsswitch.conf Classification: openSUSE Product: openSUSE 11.2 Version: Final Platform: Other OS/Version: Other Status: NEW Severity: Normal Priority: P5 - None Component: Network AssignedTo: bnc-team-screening@forge.provo.novell.com ReportedBy: dpecka@techniservit.cz QAContact: qa@suse.de Found By: --- Blocker: --- User-Agent: Opera/9.80 (X11; Linux i686; U; en) Presto/2.2.15 Version/10.00 hi i have experienced, that suse has by default as ^host: entry in /etc/nsswitch.conf : hosts: files mdns4_minimal [NOTFOUND=return] dns it leads, mixed with windows DNS server, to weird dns subsystem behaviour like: 1) ping $fqdn ## fails 2) ping $shortname ## suceed and returns $fqdn 3) dig $fqdn && dig $shortname ## suceed, same for *host|nslookup utility example:
host s10u7-esx.dmtest.local s10u7-esx.dmtest.local has address 192.168.60.201
ping -w 3 s10u7-esx.dmtest.local ping: unknown host s10u7-esx.dmtest.local
dig s10u7-esx.dmtest.local ; <<>> DiG 9.5.0-P2 <<>> s10u7-esx.dmtest.local ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 29670 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;s10u7-esx.dmtest.local. IN A ;; ANSWER SECTION: s10u7-esx.dmtest.local. 3600 IN A 192.168.60.201 ;; Query time: 5 msec ;; SERVER: 192.168.60.11#53(192.168.60.11) ;; WHEN: Fri Nov 27 13:39:09 2009 ;; MSG SIZE rcvd: 56
cat /etc/resolv.conf search dmtest.local nameserver 192.168.60.111 domain dmtest.local
. this problem could be fixed by correcting entry to: hosts: files dns mdns4_minimal [NOTFOUND=return] regards and thanks for SUSE, daniel Reproducible: Always Steps to Reproduce: 1. 2. 3. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c1 --- Comment #1 from Daniel Pecka <dpecka@techniservit.cz> 2009-11-30 11:00:56 UTC --- ps. i have been sniffing around a bit and this issue can't be reproduced on other Linux and Unix systems .. i have tested: Fedora, Debian, freeBSD and Solaris .. none of listed systems contains in nsswitch.conf file a option "mdns4_minimal" and works out of box with default dhcp client .. ave -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c2 Jan Šembera <jsembera@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jsembera@novell.com AssignedTo|bnc-team-screening@forge.pr |pbaudis@novell.com |ovo.novell.com | --- Comment #2 from Jan Šembera <jsembera@novell.com> 2009-11-30 15:18:45 UTC --- Resolver -> pasky. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c3 Petr Baudis <pbaudis@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |pbaudis@novell.com AssignedTo|pbaudis@novell.com |maw@novell.com --- Comment #3 from Petr Baudis <pbaudis@novell.com> 2009-11-30 16:36:04 UTC --- Daniel, does removing [NOTFOUND=return] fix the issue for you? I have no idea why is it in there... This is inserted to nsswitch.conf by nss-mdns, passing on... :) -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c4 --- Comment #4 from Daniel Pecka <dpecka@techniservit.cz> 2009-11-30 17:13:13 UTC --- Created an attachment (id=330065) --> (http://bugzilla.novell.com/attachment.cgi?id=330065) ping strace hi Peter, unfortunately not .. it rather seems like it depends on order at ^hosts: line, because of one would think, that obscure mdns4_minimal stucks it. it works until standard "dns" is just before mdns* entry independently where is "[NOTFOUND=return]" .. and iirc i thought, that this *return entry must|should be at the end of line anyway .. i'm appending with this message strace output from ping .. in *tgz archive are two files .. ping.good as working ping strace and ping.bad as malfunctioned ping strace .. i am restarting nscd after changes in nsswitch.conf regards -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c5 --- Comment #5 from Daniel Pecka <dpecka@techniservit.cz> 2009-11-30 17:16:04 UTC --- and ps. Peter: only changes which were been done is changing order in nsswitch.conf and restarting nscd daemon .. it simply won't run if dns is not before mdns* .. ave -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c7 Petr Baudis <pbaudis@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO Info Provider| |vuntz@novell.com --- Comment #7 from Petr Baudis <pbaudis@novell.com> 2009-11-30 18:58:20 UTC --- Vincent (I hope you are the right person for this :), can you please reassign this to the current nss-mdns maintainer, and also fix that information in GNOME:Factory metainfo? -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c8 Vincent Untz <vuntz@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW CC| |vuntz@novell.com Info Provider|vuntz@novell.com | --- Comment #8 from Vincent Untz <vuntz@novell.com> 2009-11-30 21:08:47 UTC --- I have no idea who is the current nss-mdns maintainer. It's yet another package that was inherited by the GNOME team for obscure reasons... FWIW, reading the doc on http://0pointer.de/lennart/projects/nss-mdns/, it looks like the recommended setting is: hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4 Can you test this? If this works, I guess I can try to update the package to fix this. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c9 --- Comment #9 from Daniel Pecka <dpecka@techniservit.cz> 2009-12-01 07:32:06 UTC --- well boys .. 1) "[NOTFOUND=return]" option in nsswitch.conf causes, that while reached within resolving process, resolving ends, so this option *must be on the end of the line .. everything *after will be never used ;) simply move "[NOTFOUND=return]" just after "files", `rcnscd restart` and see .. 2) @Vincent, ad.your_recommendation) even if NOTFOUND= option moved at the end, resolving stucks and common "dns" entry is used after "mdns4_minimal" timeouts. ## here we're waiting several seconds for mdns4_minimal timeout to use "dns" hosts: files mdns4_minimal dns [NOTFOUND=return] ## this works good as far as mdns4_minimal is not used hosts: files dns mdns4_minimal [NOTFOUND=return] ## this default entry is simply bad, because of "dns" or "mdns4" will be never used hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4 regards -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c10 --- Comment #10 from Daniel Pecka <dpecka@techniservit.cz> 2009-12-01 07:59:44 UTC --- Created an attachment (id=330196) --> (http://bugzilla.novell.com/attachment.cgi?id=330196) ltrace and strace with following forks i have attached strace and ltrace output with: hosts: files mdns4_minimal dns [NOTFOUND=return] ^^ where you can see mdns4_minimal timeout .. regards -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c11 Petr Baudis <pbaudis@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |NEEDINFO Info Provider| |dpecka@techniservit.cz --- Comment #11 from Petr Baudis <pbaudis@novell.com> 2009-12-01 08:38:42 UTC --- Daniel, [NOTFOUND=return] means that if the last NSS module returned "not found" status, the lookup should not continue. But the important thing to realize is that "not found" status is different from "failed" status (e.g. non-existing DNS record vs failing DNS server), and that mdns_minimal always fails if this is not a zeroconf hostname (name ending with .local etc.). So by now I understand why [NOTFOUND=return] is where it is and it looks reasonably. There are two problems here: * mdns_minimal times out; it seems that it does that while talking to avahi, can you also attach strace to avahi daemon and have a look at what is it doing? * mdns_minimal returns not-found instead of failure on timeout. Looks like simply a bug. Then there is a third problem that it seems nss_mdns is currently unmaintained; if we can't solve this bug, I think we will have to discuss in the opensuse community whether to continue shipping nss_mdns. But let's see if something won't be obvious from avahi strace first. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
ping s10u7-esx.dmtest.local
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c12 Daniel Pecka <dpecka@techniservit.cz> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |NEW Info Provider|dpecka@techniservit.cz | --- Comment #12 from Daniel Pecka <dpecka@techniservit.cz> 2009-12-01 09:23:02 UTC --- Created an attachment (id=330220) --> (http://bugzilla.novell.com/attachment.cgi?id=330220) avahi strace output well Peter, sorry but i am still in doubts about order at ^hosts: line .. ## this strictly causes, that dns won't be used at all hosts: files [NOTFOUND=return] dns ## this, leads to behaviour below hosts: files mdns4_minimal [NOTFOUND=return] dns ----------------------------------------------- ping: unknown host s10u7-esx.dmtest.local
nslookup s10u7-esx.dmtest.local Server: 192.168.60.11 Address: 192.168.60.11#53
Name: s10u7-esx.dmtest.local Address: 192.168.60.201 ----------------------------------------------- ## this seems like succeeds after mdns4_minimal timeout hosts: files mdns4_minimal dns [NOTFOUND=return] ## .. but ok, i'm attaching avahi strace with hosts: files mdns4_minimal [NOTFOUND=return] dns . which is default entry. strace -fo /tmp/avahi.strace -p `pgrep avahi` & ping s10u7-esx.dmtest.local & wait `pgrep -f dmtest.local`; pkill strace regards -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c13 --- Comment #13 from Daniel Pecka <dpecka@techniservit.cz> 2009-12-01 09:34:05 UTC --- . now i can see, that for real app like ping causes [NOTFOUND=return] before "dns" message "unknown host: ...", but nslookup or dig works .. but anyway, shouldn't it be rather: hosts: files mdns4_minimal [NOTFOUND=continue] dns regards -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c14 Petr Baudis <pbaudis@novell.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |INVALID --- Comment #14 from Petr Baudis <pbaudis@novell.com> 2009-12-01 09:43:31 UTC --- Oh, I'm sorry, I completely missed that you are using .local; this namespace is reserved for mDNS and mDNS will snatch any DNS requests there - you need to either start using a different TLD or stop using mDNS on your system. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c15 --- Comment #15 from Daniel Pecka <dpecka@techniservit.cz> 2009-12-01 11:36:07 UTC --- no, problem is elsewhere Peter !! [NOTFOUND=return] before "dns" entry causes, that dns will be never used if mDNS fails .. default behaviour is [NOTFOUND=continue] .. i am wondering why you've closed a bug .. even if mDNS works good, but not for *.local namespace, default ^hosts: entry is in SUSE bad !! it doesn't give any sense imho to have it this order .. regards -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
http://bugzilla.novell.com/show_bug.cgi?id=558878 http://bugzilla.novell.com/show_bug.cgi?id=558878#c16 --- Comment #16 from Daniel Pecka <dpecka@techniservit.cz> 2009-12-01 11:53:23 UTC --- ah sorry Peter .. i can see now. you're true .. i didn't know, that *.local namespace is reserved for avahi regards -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
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