Re: libnfsidmap: Virtual domains/users handling with at sign in idmap

[HABIB Ramzi <ramzi@nomado.eu>]

You're welcome.
The patch fixes the problem if not using kerberos.
I checked the latest version (0.23, in testing and unstable packages. 
Doesn't apply for oldstable and stable ones) from citi's website and it 
seems there's an additional fix to make for function 
"nss_gss_princ_to_ids" in nss.c file on line 279 :

/////////////////////////////////////////////////

     /* get princ's realm */
     princ_realm = strstr(princ, "@");
     if (princ_realm == NULL)
         return -EINVAL;
     princ_realm++;

////////////////////////////////////////////////

I'll check that soon and get back to you with the results.

Ramzi

Le 11/05/2010 15:07, Kevin Coffman a écrit :
> Thanks.  Unless someone else sees a problem with this, I'll apply it.
>
> On Tue, May 11, 2010 at 9:07 AM, HABIB Ramzi<ramzi@nomado.eu>  wrote:
>    
>> Subject: libnfsidmap: Virtual domains/users handling with at sign in idmap
>> Package: libnfsidmap
>> Version: 0.23
>> Severity: normal
>> Tags: patch
>>
>> *** Please type your report below this line ***
>>
>> Idmap fails to map uid to localname or vice versa in case an 'at' ( @ ) sign
>> is included in the localname.
>> This is particularly the case of virtual domains username where
>> a user@virtual_domain is in fact the username and its @ sign conflicts with
>> username@idmap_domain format used by idmap to handle uid/localname
>> conversions.
>> Where username = user@virtual_domain.
>> Idmap is still able to map uid/localname correctly when the username does
>> not
>> include an @ sign.
>> Both NFS Server and Client are PAM/NSS clients of an OpenLDAP Server that
>> handles users&  groups. NFSv4 is used and without kerberos and "nsswitch"
>> Translation method is used rather than umich_ldap.
>> Idmap looks for the first occurrence of and @ sign in the name string
>> and assumes that the @ sign is the one of user@virtual_domain rather than
>> using the one of username@idmap_domain (user@virtual_domain@idmap_domain).
>> The function "strip_domain" is defined in nss.c file and uses "strchr"
>> function on line 138 to find the first occurrence of an @ sign from the name
>> string.
>> As the name string includes 2 occurrences, the domain resulting from that
>> (virtual_domain@idmap_domain) fails to match with the configured idmap
>> domain
>> (idmap_domain) and this causes idmap returning a null value.
>> Switching from "strchr" to "strrchr" simply fix the problem as it would look
>> for the last occurrence rather than the first one and therefore has a
>> resulting
>> domain that matched the idmap one.
>> This obviously makes sense as a URI should be read from right to left and
>> not
>> from left to right when handling domains.
>> The idmap domain is this way the root domain and all virtual domains
>> included
>> in the username it handles will not conflicts with it.
>>
>> A patch is included here below :
>>
>> libnfsidmap_0.23_fix_at_sign_user_with_domain.diff
>>
>> //////////////////////////////////////////////////////////////////
>>
>> --- libnfsidmap-0.23.orig/nss.c    2009-07-29 22:19:06.000000000 +0200
>> +++ libnfsidmap-0.23/nss.c    2010-05-11 15:02:13.000000000 +0200
>> @@ -135,7 +135,7 @@
>>      char *l = NULL;
>>      int len;
>>
>> -    c = strchr(name, '@');
>> +    c = strrchr(name, '@');
>>      if (c == NULL&&  domain != NULL)
>>          goto out;
>>      if (c == NULL&&  domain == NULL) {
>>
>> //////////////////////////////////////////////////////////////////
>>
>> The patch applies to all archs.
>> Versions checked :
>> Debian :
>> libnfsidmap2 0.18-0 (oldstable)
>> libnfsidmap2 0.20-1 (stable)
>> libnfsidmap2 0.23-2 (testing,unstable)
>>
>> -- System Information:
>> Debian Release: 5.0.4
>>   APT prefers stable
>>   APT policy: (500, 'stable')
>> Architecture: amd64 (x86_64)
>>
>> Kernel: Linux 2.6.26-2-amd64 (SMP w/1 CPU core)
>> Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8)
>> Shell: /bin/sh linked to /bin/bash
>>
>> Versions of packages libnfsidmap2 depends on:
>> ii  libc6                       2.7-18lenny2 GNU C Library: Shared libraries
>> ii  libldap-2.4-2               2.4.11-1+lenny1   OpenLDAP libraries
>>
>> Ramzi HABIB
>> ramzi<at>  nomado.eu
>>
>>      
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