Bug#833296: exim4-config: dpkg-reconfigure exim4-config: misleading message

[Mauro Salvini]

> Hi,
> 
> thanks for your bug report. Superb research, well done.

Hi,

thank you, it's my first bug report, glad to hear that is well done :-)

> @ expands to primary_hostname. Are you manualy setting this in your
> configuration?

No, i never set this variable in my configuration.
/var/lib/exim4/config.autogenerated contains

.ifdef MAIN_HARDCODE_PRIMARY_HOSTNAME
primary_hostname = MAIN_HARDCODE_PRIMARY_HOSTNAME
.endif

and MAIN_HARDCODE_PRIMARY_HOSTNAME is never set.

About this, if during dpkg-reconfigure exim4-config I set "Keep number
of DNS queries minimal (Dial-on-Demand)" to yes,
MAIN_HARDCODE_PRIMARY_HOSTNAME becomes defined as myhost.mydomain.local,
and exim4 delivers mail in the right way.


> If uname() returns a single-component name, Exim calls gethostbyname()
> (or getipnodebyname() where available) in an attempt to acquire a
> fully qualified host name.
> 
> Can you check what your gethostbyname/getipnodebyname returns?

I wrote this code snippet (getipnodebyname() is not available in my
system):

#include <stdio.h>
#include <netdb.h>
#include <sys/utsname.h>

int main()
{
        struct utsname buf;
        uname(&buf);
        printf("hostname by uname(): %s\n", buf.nodename);

        struct hostent *hent = gethostbyname(buf.nodename);
        printf("hostname by gethostbyname(): %s\n", hent->h_name);

        return 0;
}

It returns:

hostname by uname(): myhostname
hostname by gethostbyname(): myhostname.mydomain.local

> I guess that there is something not right with your /etc/hosts which
> misguides gethostbyname. I have never fully understood what to do with
> /etc/hosts if one does not have a static IP address, and since all my
> hosts do have static IP addresses, I have neve had a problem like that.
> 
> For starters, I'd try to add an entry with your full host name for
> the IP address your network interface actually has.

I tried with a /etc/hosts like this:

127.0.0.1 localhost
192.168.0.10 myhostname.mydomain.local myhostname

but behavior is the same.

(by the way: static IP address means manually-assigned IP address only
or also DHCP-assigned IP address that is always the same because is
based on a static map on DHCP server?)


I also tried "exim -bt -d+all username" on various scenarios:

- /etc/mailname set with FQDN, "Other destinations for which mail is
accepted" during dpkg-reconfigure set with FQDN, hostname set as
myhostname, it states:
08:53:19  3350 local_part=username domain=myhostname.mydomain.local
08:53:19  3350 checking domains
08:53:19  3350 myhostname.mydomain.local in
"@:localhost:myhostname.mydomain.local"? yes (matched
"myhostname.mydomain.local")

so it does not match "@"

- /etc/mailname set with FQDN, "Other destinations for which mail is
accepted" during dpkg-reconfigure leaved blank, hostname set as
myhostname.mydomain.local, it states:
08:56:56  3363 local_part=username domain=myhostname.mydomain.local
08:56:56  3363 checking domains
08:56:56  3363 myhostname.mydomain.local in "@:localhost"? yes (matched
"@")

so it right matches "@".

Thank you again, greetings

Mauro