Domain ordering a possible solution!?
Khalid Sattar
domain ordering I decided to find a sloution too. What I have come up
with seems to work but would like comments from sendmail guru's to
point out if I am wrong or have made wrong assumptions or headed in
the right direction.
I believe that one of the possible reason why the domain ordering
causes confusion is because sendmail does not have a complete list of
NRS sites and it tries expansions of a partial address by looking at
the components of the supplied address. However with the ida sendmail
is now possible to keep a full database of all NRS mail sites and thus
lookup address as a whole. I have been trying on that assumption.
I basically try and keep the user specified (possibly partial address)
separate and tagging it with diffenent partial domain until either a
match is found or I run out of domains. Here is an example - we
have a site uk.ac.ex.ca which has been causing problems bacause it
clashes with the Canada top level.
When the user specifies any address, eg ex.ca I apply
cs.exeter.ac.uk
exeter.ac.uk
ac.uk
uk
to "ex.ca" in turn until a match is found - if not found then I apply
the abbreviated doamins
if that fails I reverse the user supplied address (ex.ca -> ca.ex) and
try again. If at the end there still no match then I return the user
supplied address (ex.ca) which would then get handled by rule set 0 which
will either find a top level domain or return an error.
In the example above uk.ac.ex.ca, ac.ex.ca, ex.ca, ca, (in either NRS
or RFC822 order) will match and return the fully qualified address
where as fred.ca will return fred.ca and will get handle by ruleset 0
and sent to Canada using the appropriate gateway.
For details read on...
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Here are my rule set 3, 26 and 27 (the later two are new ones which
essentially do the work of S10 and S11). Please note that this is a
testing of an idea so it may break somethings for the moment.
Macro Z contains the abbreviated domain "cs.ex.ac.uk"
Macro J contains the std domain "cs.exeter.ac.uk"
X points to teh dbm database of all NRS mail sites
My changes are preceded with a *
S3
# handle special cases
R$- $@$1 return "user"
R~$- $@~$1 return "~ user"
# basic textual canonicalisation
R$*<$*>$* $2 basic RFC 822 parsing
R$+\ at\ $+ $1@$2 " at " -> "@" for RFC 822
R$+%$+ $1@$2 convert '%'s to '@'s
R$+@$+@$+ $1%$2@$3 then reduce to only one '@'
# Address conversions.
R@$+:$+ $:$>5@$1:$2 RFC822 to Percent form
R$+::$+ $1!$2 decnet to uucp form
R$+!$+ $:$>7$1!$2 uucp to Percent form
R$+@$+.$+ $:$>13$1@$2.$3 NRS ordering to 822 ordering
# Domain name expansion.
OKX/u3/misc/admin/developments/sendmail-2.1/expya/Sites
*R$+@$+ $:$>26$1@$2 # try qualifying the address
*R$+@$+?$- $:?$>9$1@$2 # no match reverse address
*R?$+@$+ $:$>26$1@$2 # no match try with flipped address
*R$+@$+?$- $:$>13$1@$2 # no match flip address again
R$+@$+ $:$>15$1@$2 standardise local domain name
S26
*R$+@$+ $: $1@$(X $2 $: $2 ? $J $) # match - if not tag the domain
*R$+@$+?$+ $: $>27 $1@$2 ? $3
*R$+@$+?$+ $: $>27 $1@$2 ? $Z # try with abbrev domain
S27
*R$+@$+?$-$+ $1@$(X $2.$3$4 $: $2?$4 $) # apply partial domains
*R$+@$+?$- $: $1@$( X $2.$3 $: $2?$3 $)
Here is an example run from sendmail
/usr/lib/sendmail -bt -Cexpya.cf
ADDRESS TEST MODE
Enter <ruleset> <address>
[Note: No initial ruleset 3 call]
| 3 kha...@ex.ca
rewrite: ruleset 3 input: khalid @ ex . ca
rewrite: ruleset 13 input: khalid @ ex . ca
rewrite: ruleset 13 returns: khalid @ ex . ca
rewrite: ruleset 26 input: khalid @ ex . ca
rewrite: ruleset 27 input: khalid @ ex . ca ? cs . exeter . ac . uk
rewrite: ruleset 27 returns: khalid @ ex . ca ? uk
rewrite: ruleset 27 input: khalid @ ex . ca ? cs . ex . ac . uk
rewrite: ruleset 27 returns: khalid @ ex . ca ? uk
rewrite: ruleset 26 returns: khalid @ ex . ca ? uk
rewrite: ruleset 9 input: khalid @ ex . ca
rewrite: ruleset 9 returns: khalid @ ca . ex
rewrite: ruleset 26 input: khalid @ ca . ex
rewrite: ruleset 27 input: khalid @ ca . ex ? cs . exeter . ac . uk
rewrite: ruleset 27 returns: khalid @ ca . ex . ac . uk
rewrite: ruleset 26 returns: khalid @ ca . ex . ac . uk
rewrite: ruleset 15 input: khalid @ ca . ex . ac . uk
rewrite: ruleset 15 returns: khalid @ ca . ex . ac . uk
rewrite: ruleset 3 returns: khalid @ ca . ex . ac . uk
| 3 kha...@ubu.ca
rewrite: ruleset 3 input: khalid @ ubu . ca
rewrite: ruleset 13 input: khalid @ ubu . ca
rewrite: ruleset 13 returns: khalid @ ubu . ca
rewrite: ruleset 26 input: khalid @ ubu . ca
rewrite: ruleset 27 input: khalid @ ubu . ca ? cs . exeter . ac . uk
rewrite: ruleset 27 returns: khalid @ ubu . ca ? uk
rewrite: ruleset 27 input: khalid @ ubu . ca ? cs . ex . ac . uk
rewrite: ruleset 27 returns: khalid @ ubu . ca ? uk
rewrite: ruleset 26 returns: khalid @ ubu . ca ? uk
rewrite: ruleset 9 input: khalid @ ubu . ca
rewrite: ruleset 9 returns: khalid @ ca . ubu
rewrite: ruleset 26 input: khalid @ ca . ubu
rewrite: ruleset 27 input: khalid @ ca . ubu ? cs . exeter . ac . uk
rewrite: ruleset 27 returns: khalid @ ca . ubu ? uk
rewrite: ruleset 27 input: khalid @ ca . ubu ? cs . ex . ac . uk
rewrite: ruleset 27 returns: khalid @ ca . ubu ? uk
rewrite: ruleset 26 returns: khalid @ ca . ubu ? uk
rewrite: ruleset 13 input: khalid @ ca . ubu
rewrite: ruleset 9 input: khalid @ ca . ubu
rewrite: ruleset 9 returns: khalid @ ubu . ca
rewrite: ruleset 13 returns: khalid @ ubu . ca
rewrite: ruleset 15 input: khalid @ ubu . ca
rewrite: ruleset 15 returns: khalid @ ubu . ca
rewrite: ruleset 3 returns: khalid @ ubu . ca
| 3 kha...@gb.rl
rewrite: ruleset 3 input: khalid @ gb . rl
rewrite: ruleset 13 input: khalid @ gb . rl
rewrite: ruleset 9 input: khalid @ gb . rl
rewrite: ruleset 9 returns: khalid @ rl . gb
rewrite: ruleset 13 returns: khalid @ rl . gb
rewrite: ruleset 26 input: khalid @ rl . gb
rewrite: ruleset 27 input: khalid @ rl . gb ? cs . exeter . ac . uk
rewrite: ruleset 27 returns: khalid @ rl . gb ? uk
rewrite: ruleset 27 input: khalid @ rl . gb ? cs . ex . ac . uk
rewrite: ruleset 27 returns: khalid @ rl . gb ? uk
rewrite: ruleset 26 returns: khalid @ rl . gb ? uk
rewrite: ruleset 9 input: khalid @ rl . gb
rewrite: ruleset 9 returns: khalid @ gb . rl
rewrite: ruleset 26 input: khalid @ gb . rl
rewrite: ruleset 27 input: khalid @ gb . rl ? cs . exeter . ac . uk
rewrite: ruleset 27 returns: khalid @ gb . rl . ac . uk
rewrite: ruleset 26 returns: khalid @ gb . rl . ac . uk
rewrite: ruleset 15 input: khalid @ gb . rl . ac . uk
rewrite: ruleset 15 returns: khalid @ gb . rl . ac . uk
rewrite: ruleset 3 returns: khalid @ gb . rl . ac . uk
| 3 k...@acorn.co
rewrite: ruleset 3 input: ks @ acorn . co
rewrite: ruleset 13 input: ks @ acorn . co
rewrite: ruleset 13 returns: ks @ acorn . co
rewrite: ruleset 26 input: ks @ acorn . co
rewrite: ruleset 27 input: ks @ acorn . co ? cs . exeter . ac . uk
rewrite: ruleset 27 returns: ks @ acorn . co . uk
rewrite: ruleset 26 returns: ks @ acorn . co . uk
rewrite: ruleset 15 input: ks @ acorn . co . uk
rewrite: ruleset 15 returns: ks @ acorn . co . uk
rewrite: ruleset 3 returns: ks @ acorn . co . uk
Comments suggestions welcomed.
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Khalid Sattar JANET : ad...@uk.ac.exeter.cs
Computer Science Dept. UUCP : ad...@expya.uucp
University of Exeter BITNET : admin%uk.ac.exeter.cs@ukacrl
Exeter, UK. Tel : +44 392 264062