/mail/lib/rewrite and net!$smtp

/mail/lib/rewrite and net!$smtp

[Steven Stallion]

All,

I was reviewing my mail setup this evening and I came across an old
kludge to forward mail to a relay host on my network in
/mail/lib/rewrite.  I used a host-specific dial string rather than
net!$smtp.  For kicks, I reverted back to the classic behavior to try
and sort out why the lookup fails and I'm hitting a brick wall
(again).

I've try adding smtp= entries to the sys, ipnet, and dom entries in
/lib/ndb/local and nothing seems to be taking.  I'm testing changes by
issuing an ndb/csquery and I'm always getting the same result:

	% ndb/csquery /net/cs 'net!$smtp!smtp'
	translating net!$smtp!smtp: cs: can't translate address: dns: name does not exist

I haven't found much other than a thread dating back to 2013 from fgb,
which appears related but doesn't seem to have a solution that works
for me.

Any ideas?
Steve

Re: [9fans] /mail/lib/rewrite and net!$smtp

[Richard Miller]

>         % ndb/csquery /net/cs 'net!$smtp!smtp'
>         translating net!$smtp!smtp: cs: can't translate address: dns: name does not exist

Don't give up yet, it works for me:

term% ndb/csquery /net/cs 'net!$smtp!smtp'
/net/tcp/clone 93.93.130.6!25
/net/tcp/clone 93.93.131.52!25
/net/tcp/clone 2a00:1098::86:1000:0:2:1!25
/net/tcp/clone 2a00:1098::82:1000:0:2:1!25

In my /lib/ndb/local I have this:

ipnet=localnet
	ip=192.168.0.0 ipmask=255.255.0.0
	smtp=mx.mythic-beasts.com
	ntp=pool.ntp.org
	dnsdomain=hamnavoe.com
	MAILSERVER=atom

Re: [9fans] /mail/lib/rewrite and net!$smtp

[Steven Stallion]

> Don't give up yet, it works for me:
> 
> term% ndb/csquery /net/cs 'net!$smtp!smtp'
> /net/tcp/clone 93.93.130.6!25
> /net/tcp/clone 93.93.131.52!25
> /net/tcp/clone 2a00:1098::86:1000:0:2:1!25
> /net/tcp/clone 2a00:1098::82:1000:0:2:1!25
> 
> In my /lib/ndb/local I have this:
> 
> ipnet=localnet
>         ip=192.168.0.0 ipmask=255.255.0.0
>         smtp=mx.mythic-beasts.com
>         ntp=pool.ntp.org
>         dnsdomain=hamnavoe.com
>         MAILSERVER=atom

Thanks!  Unfortunately my MX host only exposes port 587 for relaying
mail outside of the domain.  I suppose I could update cs to permit
specifying a port number in ndb for $smtp, but I'm not sure that's any
better than just specifying the relay host directly in rewrite.

Cheers,
Steve

Re: /mail/lib/rewrite and net!$smtp

[Steven Stallion]

> I haven't found much other than a thread dating back to 2013  from fgb,
> which appears related but doesn't seem to have a solution that works
> for me.

Apologies, this was a thread from 2007 though fgb was not the original
poster.

After digging a little more based on one of steve's suggestions in the
thread to run upas/smtp with -d, I think this makes much more sense
now:

% upas/smtp -d 'net!$smtp' stallion foo@bar.com
expanding /net!$smtp
sending /net/dns 'x.x.x.x mx'
dns: dns: name does not exist
mxlookup returns nothing
smtp: cs: can't translate address: dns: name does not exist (net!$smtp)

So it looks like upas will attempt to do an mx lookup for smtp; which
means it's expecting a domain rather than the dial string of an SMTP
server.

After digging into the source a bit, it looks like mkdial in
/sys/src/cmd/upas/smtp/mkdial.c is to blame; it also looks like it's
not possible to specify a port number, which makes sense given that
its relying on an mx lookup.

I suppose in the end the kludge I added was the right solution after
all.  Go figure.

Steve