Add recognition of SMTP error codes in bespoke messages.

[users/jgh/exim.git] / doc / doc-misc / WishList

diff --git a/doc/doc-misc/WishList b/doc/doc-misc/WishList
index 8c058484ca86fca804e1648ae52807fae17db9c2..7fadb1ee326d7180b49c10ee06f6028cde7be8ad 100644 (file)
--- a/doc/doc-misc/WishList
+++ b/doc/doc-misc/WishList
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-misc/WishList,v 1.58 2006/02/13 15:09:30 ph10 Exp $
+$Cambridge: exim/doc/doc-misc/WishList,v 1.69 2006/06/30 08:53:49 ph10 Exp $

 
 EXIM 4 WISH LIST
 ----------------
 
 EXIM 4 WISH LIST
 ----------------


@@ -295,16 +295,6 @@ David Carter
 So several warnings could be generated as the mailbox got bigger and bigger.
 ------------------------------------------------------------------------------
 
 So several warnings could be generated as the mailbox got bigger and bigger.
 ------------------------------------------------------------------------------
 

-(146) 15-May-2000 M  Allow SMTP error codes in retry rules
-
-This would allow special handling of certain errors from certain hosts. In
-particular, it would allow failing of certain 4xx codes.
-
-This is now available for 4xx responses to RCPT commands. Is anything more
-needed? Apparently, yes; there's been a request for a similar feature for MAIL
-commands.
-------------------------------------------------------------------------------
-

 (148) 15-May-2000 S  Warn recipient if message rejected for quota excession.
 Heinz Ekker
 
 (148) 15-May-2000 S  Warn recipient if message rejected for quota excession.
 Heinz Ekker
 


@@ -1220,12 +1210,6 @@ Maybe there should always be a variable with the error message for all the
 different kinds of verify failure.
 ------------------------------------------------------------------------------
 
 different kinds of verify failure.
 ------------------------------------------------------------------------------
 

-(196) 30-Sep-03 S  A way of detecting whether it was HELO or EHLO in the ACL
-
-$received_protocol isn't reset until after the command is accepted (which
-seems right), and $smtp_data shows only the arguments. Maybe $smtp_command?
-------------------------------------------------------------------------------
-

 (197) 30-Sep-03 S  MACROS_DROP_PRIVS and ALT_CONFIG_DROP_PRIVS
 
 Now that alternative configurations can be restricted to certain directories,
 (197) 30-Sep-03 S  MACROS_DROP_PRIVS and ALT_CONFIG_DROP_PRIVS
 
 Now that alternative configurations can be restricted to certain directories,


@@ -1261,11 +1245,6 @@ This is an option that turns all hard bounces into soft bounces. The idea is
 that it can be used as a safety-net while testing configurations. Instead of a
 local bounce, the message stays on the queue; instead of 5xx SMTP responses,
 4xx ones are given.
 that it can be used as a safety-net while testing configurations. Instead of a
 local bounce, the message stays on the queue; instead of 5xx SMTP responses,
 4xx ones are given.

-
-The ability to do the opposite - turn 4xx into 5xx under certain circumstances
-might also be useful (e.g. after a certain time). This might best be done by
-extending the retry logic to recognize 4xx as a special error. (This is now
-done.)

 ------------------------------------------------------------------------------
 
 (202) 10-Oct-03 S  -bvsomething to do a callout after the verify
 ------------------------------------------------------------------------------
 
 (202) 10-Oct-03 S  -bvsomething to do a callout after the verify


@@ -1303,7 +1282,6 @@ permanent ones after some fixed time.
 ------------------------------------------------------------------------------
 
 (209) 31-Oct-03 S  a way of making crashes in pipe commands temporary errors
 ------------------------------------------------------------------------------
 
 (209) 31-Oct-03 S  a way of making crashes in pipe commands temporary errors

-

 ------------------------------------------------------------------------------
 
 (210) 31-Oct-03 S  runtime option to change the daemon name used for tcprwappers
 ------------------------------------------------------------------------------
 
 (210) 31-Oct-03 S  runtime option to change the daemon name used for tcprwappers


@@ -1325,14 +1303,6 @@ See also 333.
 Unfortunately, this isn't quite as trivial as it seems.
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 Unfortunately, this isn't quite as trivial as it seems.
 ------------------------------------------------------------------------------
 

-(215) 14-Nov-03 S  A way of turning off message-submission fix-ups
-
-Globally, and perhaps also via an ACL control so that it can be done on a
-per-message basis. Is this still needed? Since this item was added to this
-list, default fixups for non-local messages have been removed, and control =
-submission has been added.
-------------------------------------------------------------------------------
-

 (215) 26-Nov-03 M/L Conversion of IDNA domain names for logging
 
 IDNA (RFCs 3490-3492) converts domains names containing non-ASCII characters
 (215) 26-Nov-03 M/L Conversion of IDNA domain names for logging
 
 IDNA (RFCs 3490-3492) converts domains names containing non-ASCII characters


@@ -1344,13 +1314,6 @@ e.g. exigrep, eximstats, will be automatically handled if the logs are
 changed.)
 ------------------------------------------------------------------------------
 
 changed.)
 ------------------------------------------------------------------------------
 

-(216) 27-Nov-03 S  Option to bounce if required TLS doesn't happen
-
-This is for the smtp transport with hosts_require_tls set. Currently, it
-defers. Possibly the best approach is to make the error one that can be seen by
-the retry logic.
-------------------------------------------------------------------------------
-

 (217) 27-Nov-03 M  A function to pass back variables from Perl
 
 This is a function that can be called from Perl, to take a name and a value and
 (217) 27-Nov-03 M  A function to pass back variables from Perl
 
 This is a function that can be called from Perl, to take a name and a value and


@@ -1456,12 +1419,6 @@ this reason, I don't really like this idea.
 (236) 02-Feb-04 S  String in local_scan that's added to the binary version string
 ------------------------------------------------------------------------------
 
 (236) 02-Feb-04 S  String in local_scan that's added to the binary version string
 ------------------------------------------------------------------------------
 

-(237) 02-Feb-04 M  Add_header in ACLs because "message" is overloaded
-
-This would be useful for verbs where "message" is an error message. See also
-333.
-------------------------------------------------------------------------------
-

 (238) 05-Feb-04 S  ${address to handle multiple addresses
 
 At present, ${address expects to see just one address. An extension would let
 (238) 05-Feb-04 S  ${address to handle multiple addresses
 
 At present, ${address expects to see just one address. An extension would let


@@ -1622,12 +1579,6 @@ For example: mainlog_selector and rejectlog_selector, with log_selector setting
 both of them.
 ------------------------------------------------------------------------------
 
 both of them.
 ------------------------------------------------------------------------------
 

-(286) 21-Jul-04 M Distinguishing a larger number of errors
-
-For instance, detecting "connection reset by peer" (ENETRESET or ECONNRESET)
-might be useful.
-------------------------------------------------------------------------------
-

 (288) 10-Aug-04 M Option for verify to require MX
 
 e.g. verify=sender/require_mx
 (288) 10-Aug-04 M Option for verify to require MX
 
 e.g. verify=sender/require_mx


@@ -1919,7 +1870,7 @@ headers should be re-planned and re-implemented in a more consistent manner.
 These are the main previous items:
 
 Exim 3 Wish List: 41, 85, 149, 187.
 These are the main previous items:
 
 Exim 3 Wish List: 41, 85, 149, 187.

-Exim 4 Wish List: 55, 62, 63, 160, 212, 237, 270, 314, 328.
+Exim 4 Wish List: 55, 62, 63, 160, 212, 270, 314, 328.

 ------------------------------------------------------------------------------
 
 (334) 07-Jun-05 M Support for messages larger than 2G
 ------------------------------------------------------------------------------
 
 (334) 07-Jun-05 M Support for messages larger than 2G


@@ -1969,7 +1920,7 @@ second. Maybe something like ${match_any{...}{...}} is needed.
 
 (341) 15-Sep-05 S Add /return_path_retain to submission mode
 
 
 (341) 15-Sep-05 S Add /return_path_retain to submission mode
 

-This would re-instate the behaviour prior to change 4.52/TF/02.
+This would re-instate the behaviour prior to change 4.52/PH/04.

 ------------------------------------------------------------------------------
 
 (342) 26-Sep-05 T Log and maybe defer odd values for condition pre-condition
 ------------------------------------------------------------------------------
 
 (342) 26-Sep-05 T Log and maybe defer odd values for condition pre-condition


@@ -1983,6 +1934,34 @@ should also defer, for compatibility with ACLs.
 
 The natural syntax for this would be to use a regex, like this:
 ${lookup regex{/some/file regex}{found-string}{not-found-string}}
 
 The natural syntax for this would be to use a regex, like this:
 ${lookup regex{/some/file regex}{found-string}{not-found-string}}

+However, it would be natural to want to use $1 etc in the found-string; this
+would be hard because of the lookup caching (if repeated, the lookup won't
+actually be done and therefore the numerical variables won't be set), and in
+any case, even without caching (and it could, I suppose, be disabled for this
+lookup) those variables are not in the right storage pool even if they were
+preserved after the lookup.
+
+An alternative approach might be to implement something like this:
+
+  ${scanfile{/some/file}{sub-expression}}
+
+where the sub-expression is expanded for every line in the file, with each line
+in turn being put into $value. This is like a conditional ${readfile, and in
+fact ${readfile could be written using ${scanfile. It would be nice to find a
+way of stopping the scan once something has happened. The only thing I can
+think of is to invent a variable that changes when scanning a line generates
+some non-null text, and then always to stop on a forced failure. That would
+allow expressions like this:
+
+  ${scanfile{/some/file}
+    {
+    ${if eq{$generated}{}{${if match{regex}{$value}{something}}} fail}
+    }}
+
+It's all rather clumsy. Once a line has matched and generated some text, the
+next iteration would stop the scan. Another thought: maybe use $scanline
+instead of $value (to save confusion) and have $scantext containing everything
+that's been generated so far. That sounds pretty flexible.

 ------------------------------------------------------------------------------
 
 (344) 10-Oct-05 M Make debug_print work in authenticators
 ------------------------------------------------------------------------------
 
 (344) 10-Oct-05 M Make debug_print work in authenticators


@@ -2011,21 +1990,66 @@ code, because of caching. Probably means we have to invent ewildlsearch and
 enwildlsearch.
 ------------------------------------------------------------------------------
 
 enwildlsearch.
 ------------------------------------------------------------------------------
 

-(348) 17-Nov-05 S Option to allow AUTH when not advertised.
+(351) 31-Mar-06 ? Allow some/all/a few internal variables to be set

 
 

-It seems that there are clients that send AUTH when it hasn't been advertised,
-some even after HELO, not even EHLO. Sigh. Possibly this should be an ACL
-control, to enable it to be restricted to certain hosts.
+The original idea was to allow "set authenticated = x" to pretend a connection
+is authenticated after other conditions are true. This can, of course, be
+packaged up using macros in other ways. Setting other variables could cause
+problems.

 ------------------------------------------------------------------------------
 
 ------------------------------------------------------------------------------
 

-(349) 13-Feb-06 S Add login_cap support to the pipe transport
+(352) 04-Apr-06 S Add +accept_defer for host lists (and maybe others)
+
+At present, a defer causes a delivery defer. For non-critical ACLs there are
+times when it may be better to accept. See also 226 and 289.
+------------------------------------------------------------------------------
+
+(354) 30-Jun-06 ? Extensions to SMTP error codes
+
+A number of ideas arose following a discussion on the mailing list. I record
+them here so that they don't get lost. The motivations were to support the 551
+bounce code and enhanced status codes. Suggestions are to add a new ACL
+feature, possibly one of:
+
+  errorcode = 511
+  control = errorcode=551
+  message = 551 xxxx
+
+where in the last case, it's recognized by being 3 digits. In all cases, the
+first digit must be "right" for the circumstance - ignore or fault if not?
+
+To handle ESC, perhaps a new variable called $smtp_errorcode, settable by an
+option in a router when it fails, would do the trick. It could be used in any
+of the above modifiers.
+------------------------------------------------------------------------------
+
+(355) 30-Jun-06 ? Facility to permit experiments with SMTP extensions
+
+This is what was suggested:
+
+- adding some expansion variables: $ehlo_extensions (which will
+   hold the remote server supported smtp extensions announced
+   in the ehlo) and $rcpt_arguments with any RCPT extra argument
+
+- a main configuration option for adding ehlo extensions to the
+   ehlo response, like:
+
+   extra_ehlo_extensions = XFOO : XBAR
+
+- a extra option for the smtp transport to add arguments to
+   the RCPT TO command, like:
+
+   rcpt_args = FOO=BAR  (will make exim issue RCPT TO:<a@b.c> FOO=BAR
+   when delivering that message)
+
+- a new acl for unknown smtp commands

 
 

-FreeBSD (and maybe others) have some functions for a per-user resource database
-of which login_cap() is one. A copile-time macro (set for FreeBSD) could enable
-a new pipe transport option to cause setclassresources() to be called to limit
-the resources used. It's a bit tricky, because it has to be done as root, but
-in the forked transport process. There will have to be some higher-level code
-to deal with this.
+This should be very simple to implement and will allow to make
+some experiments and implement custom extensions, i.e. one to
+known if remote client will redirect on 551 or not. Also the acl
+for unknown smpt command could be used for other purposes, like
+to dectect and react to some kiddies that send things like
+http://... on the smtp port.

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---- HWM 349 ------------------------------------------------------------------
+--- HWM 355 ------------------------------------------------------------------

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