1. Update version.

[exim.git] / doc / doc-txt / NewStuff

diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
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--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.28 2005/03/22 14:11:54 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.40 2005/05/10 10:19:11 ph10 Exp $

 
 New Features in Exim
 --------------------
 
 New Features in Exim
 --------------------


@@ -9,6 +9,66 @@ updated when there is a relatively large batch of changes). The doc/ChangeLog
 file contains a listing of all changes, including bug fixes.
 
 
 file contains a listing of all changes, including bug fixes.
 
 

+Exim version 4.52
+-----------------
+
+TF/01 Support for checking Client SMTP Authorization has been added. CSA is a
+      system which allows a site to advertise which machines are and are not
+      permitted to send email. This is done by placing special SRV records in
+      the DNS, which are looked up using the client's HELO domain. At this
+      time CSA is still an Internet-Draft.
+
+      Client SMTP Authorization checks are performed by the ACL condition
+      verify=csa. This will fail if the client is not authorized. If there is
+      a DNS problem, or if no valid CSA SRV record is found, or if the client
+      is authorized, the condition succeeds. These three cases can be
+      distinguished using the expansion variable $csa_status, which can take
+      one of the values "fail", "defer", "unknown", or "ok". The condition
+      does not itself defer because that would be likely to cause problems
+      for legitimate email.
+
+      The error messages produced by the CSA code include slightly more
+      detail. If $csa_status is "defer" this may be because of problems
+      looking up the CSA SRV record, or problems looking up the CSA target
+      address record. There are four reasons for $csa_status being "fail":
+      the client's host name is explicitly not authorized; the client's IP
+      address does not match any of the CSA target IP addresses; the client's
+      host name is authorized but it has no valid target IP addresses (e.g.
+      the target's addresses are IPv6 and the client is using IPv4); or the
+      client's host name has no CSA SRV record but a parent domain has
+      asserted that all subdomains must be explicitly authorized.
+
+      The verify=csa condition can take an argument which is the domain to
+      use for the DNS query. The default is verify=csa/$sender_helo_name.
+
+      This implementation includes an extension to CSA. If the query domain
+      is an address literal such as [192.0.2.95], or if it is a bare IP
+      address, Exim will search for CSA SRV records in the reverse DNS as if
+      the HELO domain was e.g. 95.2.0.192.in-addr.arpa. Therefore it is
+      meaningful to say, for example, verify=csa/$sender_host_address - in
+      fact, this is the check that Exim performs if the client does not say
+      HELO. This extension can be turned off by setting the main
+      configuration option dns_csa_use_reverse = false.
+
+      If a CSA SRV record is not found for the domain itself, then a search
+      is performed through its parent domains for a record which might be
+      making assertions about subdomains. The maximum depth of this search is
+      limited using the main configuration option dns_csa_search_limit, which
+      takes the value 5 by default. Exim does not look for CSA SRV records in
+      a top level domain, so the default settings handle HELO domains as long
+      as seven (hostname.five.four.three.two.one.com) which encompasses the
+      vast majority of legitimate HELO domains.
+
+      The dnsdb lookup also has support for CSA. Although dnsdb already
+      supports SRV lookups, this is not sufficient because of the extra
+      parent domain search behaviour of CSA, and (as with PTR lookups)
+      dnsdb also turns IP addresses into lookups in the reverse DNS space.
+      The result of ${lookup dnsdb {csa=$sender_helo_name} } has two
+      space-separated fields: an authorization code and a target host name.
+      The authorization code can be "Y" for yes, "N" for no, "X" for explicit
+      authorization required but absent, or "?" for unknown.
+
+

 Version 4.51
 ------------
 
 Version 4.51
 ------------
 


@@ -46,12 +106,20 @@ PH/02 A new expansion item for dynamically loading and calling a locally-
 
       set in Local/Makefile. The facility is not included by default (a
       suitable error is given if you try to use it when it is not there.)
 
       set in Local/Makefile. The facility is not included by default (a
       suitable error is given if you try to use it when it is not there.)

-      You load and call the function like this:
+
+      If you enable EXPAND_DLFUNC, you should also be aware of the new redirect
+      router option forbid_filter_dlfunc. If you have unprivileged users on
+      your system who are permitted to create filter files, you might want to
+      set forbid_filter_dlfunc=true in the appropriate router, to stop them
+      using ${dlfunc to run code within Exim.
+
+      You load and call an external function like this:

 
         ${dlfunc{/some/file}{function}{arg1}{arg2}...}
 
 
         ${dlfunc{/some/file}{function}{arg1}{arg2}...}
 

-      Once loaded, Exim remembers it so that it doesn't reload it in the same
-      Exim process (but of course Exim does start new processes frequently).
+      Once loaded, Exim remembers the dynamically loaded object so that it
+      doesn't reload the same object file in the same Exim process (but of
+      course Exim does start new processes frequently).

 
       There may be from zero to eight arguments to the function. When compiling
       a local function that is to be called in this way, local_scan.h should be
 
       There may be from zero to eight arguments to the function. When compiling
       a local function that is to be called in this way, local_scan.h should be


@@ -79,6 +147,100 @@ PH/02 A new expansion item for dynamically loading and calling a locally-
       you need to add -shared to the gcc command. Also, in the Exim build-time
       configuration, you must add -export-dynamic to EXTRALIBS.
 
       you need to add -shared to the gcc command. Also, in the Exim build-time
       configuration, you must add -export-dynamic to EXTRALIBS.
 

+TF/01 $received_time is a new expansion variable containing the time and date
+      as a number of seconds since the start of the Unix epoch when the
+      current message was received.
+
+PH/03 There is a new value for RADIUS_LIB_TYPE that can be set in
+      Local/Makefile. It is RADIUSCLIENTNEW, and it requests that the new API,
+      in use from radiusclient 0.4.0 onwards, be used. It does not appear to be
+      possible to detect the different versions automatically.
+
+PH/04 There is a new option called acl_not_smtp_mime that allows you to scan
+      MIME parts in non-SMTP messages. It operates in exactly the same way as
+      acl_smtp_mime
+
+PH/05 It is now possible to redefine a macro within the configuration file.
+      The macro must have been previously defined within the configuration (or
+      an included file). A definition on the command line using the -D option
+      causes all definitions and redefinitions within the file to be ignored.
+      In other words, -D overrides any values that are set in the file.
+      Redefinition is specified by using '==' instead of '='. For example:
+
+        MAC1 =  initial value
+        ...
+        MAC1 == updated value
+
+      Redefinition does not alter the order in which the macros are applied to
+      the subsequent lines of the configuration file. It is still the same
+      order in which the macros were originally defined. All that changes is
+      the macro's value. Redefinition makes it possible to accumulate values.
+      For example:
+
+        MAC1 =  initial value
+        ...
+        MAC1 == MAC1 and something added
+
+      This can be helpful in situations where the configuration file is built
+      from a number of other files.
+
+PH/06 Macros may now be defined or redefined between router, transport,
+      authenticator, or ACL definitions, as well as in the main part of the
+      configuration. They may not, however, be changed within an individual
+      driver or ACL, or in the local_scan, retry, or rewrite sections of the
+      configuration.
+
+PH/07 $acl_verify_message is now set immediately after the failure of a
+      verification in an ACL, and so is available in subsequent modifiers. In
+      particular, the message can be preserved by coding like this:
+
+         warn  !verify = sender
+               set acl_m0 = $acl_verify_message
+
+      Previously, $acl_verify_message was set only while expanding "message"
+      and "log_message" when a very denied access.
+
+PH/08 The redirect router has two new options, sieve_useraddress and
+      sieve_subaddress. These are passed to a Sieve filter to specify the :user
+      and :subaddress parts of an address. Both options are unset by default.
+      However, when a Sieve filter is run, if sieve_useraddress is unset, the
+      entire original local part (including any prefix or suffix) is used for
+      :user. An unset subaddress is treated as an empty subaddress.
+
+PH/09 Quota values can be followed by G as well as K and M.
+
+PH/10 $message_linecount is a new variable that contains the total number of
+      lines in the header and body of the message. Compare $body_linecount,
+      which is the count for the body only. During the DATA and
+      content-scanning ACLs, $message_linecount contains the number of lines
+      received. Before delivery happens (that is, before filters, routers, and
+      transports run) the count is increased to include the Received: header
+      line that Exim standardly adds, and also any other header lines that are
+      added by ACLs. The blank line that separates the message header from the
+      body is not counted. Here is an example of the use of this variable in a
+      DATA ACL:
+
+        deny message   = Too many lines in message header
+             condition = \
+               ${if <{250}{${eval: $message_linecount - $body_linecount}}}
+
+      In the MAIL and RCPT ACLs, the value is zero because at that stage the
+      message has not yet been received.
+
+PH/11 In a ${run expansion, the variable $value (which contains the standard
+      output) is now also usable in the "else" string.
+
+PH/12 In a pipe transport, although a timeout while waiting for the pipe
+      process to complete was treated as a delivery failure, a timeout while
+      writing the message to the pipe was logged, but erroneously treated as a
+      successful delivery. Such timeouts include transport filter timeouts. For
+      consistency with the overall process timeout, these timeouts are now
+      treated as errors, giving rise to delivery failures by default. However,
+      there is now a new Boolean option for the pipe transport called
+      timeout_defer, which, if set TRUE, converts the failures into defers for
+      both kinds of timeout. A transport filter timeout is now identified in
+      the log output.
+

 
 Version 4.50
 ------------
 
 Version 4.50
 ------------