On my Alpha system running Digital UNIX V3.2C, the DEC-supplied sendmail
doesn't search the name server properly. For example:
- My local domain is `hprc.utoronto.ca'.
- Another valid domain at U of T is `cs.utoronto.ca'. There is no system
`cs.hprc.utoronto.ca'.
- If handed the hostname `cs', sendmail should (and in versions from other
vendors, does) observe that neither the top-level domain `cs.' nor the
local host `cs.hprc.utoronto.ca' exists, find `cs.utoronto.ca', and use that.
- The Digital UNIX sendmail apparently gives up after the first two failures.
- Experiments with a stripped-down sendmail configuration file show that the
trouble occurs with both the $[ $] operator, and with the internal IPC mailer.
The DEC-supplied configuration file tries to paper this over by appending
the local domain string to any hostname that contains only one domain component
(i.e. doesn't contain a `.'). This helps only in organizations that don't
use subdomains; it's useless here. For example,
- if I mail to norman_at_cs, this scheme will assume I mean
norman_at_cs.hprc.utoronto.ca; wrong.
- if I mail to norman_at_gpu.utcs, this scheme will assume utcs is a
top-level domain; wrong.
The problem is specific to sendmail; other DNS clients get it right. For example,
`telnet cs' connects to cs.utoronto.ca without fuss.
I've seen similar symptoms once before; the sendmail Cray used to ship contained
code to explicitly disable resolver searches. I reported it as a bug, and they
fixed it.
Detailed examples and configuration info below. Have I missed some configuration
quirk, or has Digital shipped me a broken sendmail?
Norman Wilson
High Performance Research Computing
University of Toronto
norman_at_hprc.utoronto.ca
Details:
On the Alpha,
co$ uname -a
OSF1 rolle V3.2 148 alpha
co$ cat /etc/resolv.conf
domain hprc.utoronto.ca
nameserver 128.100.104.10
nameserver 128.100.104.50
nameserver 128.100.100.1
search hprc.utoronto.ca utoronto.ca
co$ grep hosts /etc/svc.conf
# hosts
# bind (hosts ONLY)
hosts=bind,local
co$ # n.b. no NIS involved
co$ cat x.cf
#
# shortest acceptable sendmail.cf;
# for testing
#
#
# mandatory macros
#
Dehello
Dj$w
DlFrom $g $d
Dnpostmaster
Do.:%_at_!
Dq$g$?x ($x)$.
#
# mandatory options
#
OA/usr/lib/aliases
Odb
OF0600
OL9
OQ/usr/spool/mqueue
#
# ruleset 0: send mail
#
S0
R$+_at_$+ $:$1_at_$[$2$]
R$+_at_$+ $#smtp $_at_$2 $:$1_at_$2
R$+ $#local $:$1
#
# mailers
#
Mlocal, P=/bin/mail, F=rlsmn, A=mail -d $u
Mprog, P=/bin/echo, A=echo program mailer disabled
Msmtp, P=[IPC], F=mAn, A=IPC $h, E=\r\n
(green.hprc.utoronto.ca is a valid local hostname; notice that
it is expanded correctly. cs.utoronto.ca is a valid domain,
with both MX and A records; it should be expanded, but is not.)
co$ /usr/lib/sendmail -bt -Cx.cf
ADDRESS TEST MODE
Enter <ruleset> <address>
[Note: No initial ruleset 3 call]
> 0 norman_at_green
rewrite: ruleset 0 input: norman _at_ green
rewrite: ruleset 0 returns: $# smtp $_at_ green . hprc . utoronto . ca $: norman _at_ green . hprc . utoronto . ca
> 0 norman_at_cs
rewrite: ruleset 0 input: norman _at_ cs
rewrite: ruleset 0 returns: $# smtp $_at_ cs $: norman _at_ cs
> ^D
co$
co$ nslookup # to show that it's just sendmail
Default Server: euler.hprc.utoronto.ca
Address: 128.100.104.10
> set type=mx
> cs
Server: euler.hprc.utoronto.ca
Address: 128.100.104.10
cs.utoronto.ca preference = 0, mail exchanger = yonge.cs.utoronto.ca
cs.utoronto.ca preference = 10, mail exchanger = dvp.cs.utoronto.ca
yonge.cs.utoronto.ca inet address = 128.100.1.8
yonge.cs.utoronto.ca inet address = 128.100.2.11
dvp.cs.utoronto.ca inet address = 128.100.2.81
dvp.cs.utoronto.ca inet address = 128.100.3.9
dvp.cs.utoronto.ca inet address = 128.100.1.15
>
co$
Contrast sendmail's behaviour with this, on an SGI IRIX 5.3 system.
(n.b. SGI ships a V8 sendmail.)
cg$ /usr/lib/sendmail -Cx.cf -bt
ADDRESS TEST MODE (ruleset 3 NOT automatically invoked)
Enter <ruleset> <address>
> 0 norman_at_cs
rewrite: ruleset 0 input: norman _at_ cs
rewrite: ruleset 0 returns: $# smtp $_at_ cs . utoronto . ca $: norman _at_ cs . utoronto . ca
>
Received on Mon Feb 05 1996 - 16:10:09 NZDT