= On startup spamd dies with "IO::Socket::INET: Invalid argument" =


== Overview ==

This bug is seen from time to time and is currently tracked down via the [[http://bugs.gentoo.org/show_bug.cgi?id=58122|Gentoo Bug 58122]].
The reason ''why'' it happens is yet unknown, but it seems to be caused by a broken Perl.


== Symptoms ==

When you start spamd with debugging you will see something like this:
{{{
$ spamd -D
trying to connect to syslog/unix...
no error connecting to syslog/unix
logging enabled:
        facility: mail
        socket:   unix
        output:   syslog
creating INET socket:
        Listen: 128
        LocalAddr: 127.0.0.1
        LocalPort: 783
        Proto: 6
        ReuseAddr: 1
        Type: 1
Could not create INET socket on 127.0.0.1:783: Invalid argument (IO::Socket::INET: Invalid argument)
}}}

The output above is from SpamAssassin 3.0.0, previous versions are a bit less verbose.

The [[http://www.ijs.si/software/amavisd/#faq-spam|FAQ]] on the amavisd-new site notes:

  On some operating systems the Perl module IO::Socket reports obscure error on unsuccessful connect() in non-blocking mode as:   "Invalid argument" in place of the true cause: "Connection refused". 
  The remote service should be checked if available and accessible (firewall rules? network problems?). 

  Another possible reason for "Invalid argument" reported by IO::Socket when running within chroot jail is some network-related system file missing in a chroot jail, e.g. /etc/protocols, /etc/services, /etc/netconfig, /etc/resolv.conf, /etc/nsswitch.conf, /etc/hosts, /etc/host.conf -- depending on the operating system in use.
  System debugging tools (debugger, strace, truss) may help to find the cause. 


== Diagnosis ==

The Gentoo bug mentioned above lead to the following wrong bind(2) call:
{{{
bind(5, {sa_family=0x3837 /* AF_??? */, sa_data="3\0\0\0\0\0\0\0\0\0001\306\1\0"}, 3) = -1 EINVAL (Invalid argument)
}}}

That one should actually look like:
{{{
bind(5, {sa_family=AF_INET, sin_port=htons(783), sin_addr=inet_addr("127.0.0.1")}, 16) = -1
}}}

Both the contents of the second parameter, {{{struct sockaddr *my_addr}}}, and the value of the third, {{{socklen_t addrlen}}}, are completely bogus. In hex they read:
{{{
37 38 33 00 00 00 00 00 00 00 00 00 30 31 03 30 | 783.........01.0
36 01 00                                        | 6..
}}}

Note the number 783, which is the port we try to connect on (as a string).
The characters 1 and 6 might be the Type and Proto values above.
Conclusion: Brain... err... Memfart :)


== Cure ==

An upgrade to Perl 5.8.4 helped in the case mentioned.
Recompiling Perl might have helped, too.

(MalteStretz)