1. Added Tony F's ${dlfunc expansion, slightly modified (see NewStuff).

2. Recognize ${perl even if not compiled, and give suitable error
message.

2 files changed, 121 insertions, 75 deletions

diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index b2a43652c..f366edf2c 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.93 2005/03/22 10:11:42 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/ChangeLog,v 1.94 2005/03/22 14:11:54 ph10 Exp $
 
 Change log file for Exim from version 4.21
 -------------------------------------------
@@ -7,53 +7,59 @@ Change log file for Exim from version 4.21
 Exim version 4.51
 -----------------
 
-TK/01. Added Yahoo DomainKeys support via libdomainkeys. See
-       doc/experimental-spec.txt for details. (http://domainkeys.sf.net)
-
-TK/02. Fix ACL "control" statment not being available in MIME ACL.
-
-TK/03. Fix ACL "regex" condition not being available in MIME ACL.
-
-PH/01. Installed a patch from the Sieve maintainer that allows -bf to be used
-       to test Sieve filters that use "vacation".
-
-PH/02. Installed a slightly modified version of Nikos Mavrogiannopoulos' patch
-       that changes the way the GnuTLS parameters are stored in the cache file.
-       The new format can be generated externally. For backward compatibility,
-       if the data in the cache doesn't make sense, Exim assumes it has read an
-       old-format file, and it generates new data and writes a new file. This
-       means that you can't go back to an older release without removing the
-       file.
-
-PH/03. A redirect router that has both "unseen" and "one_time" set does not
-       work if there are any delivery delays because "one_time" forces the
-       parent to be marked "delivered", so its unseen clone is never tried
-       again. For this reason, Exim now forbids the simultaneous setting of
-       these two options.
-
-PH/04. Change 4.11/85 fixed an obscure bug concerned with addresses that are
-       redirected to themselves ("homonym" addresses). Read the long ChangeLog
-       entry if you want to know the details. The fix, however, neglected to
-       consider the case when local delivery batching is involved. The test for
-       "previously delivered" was not happening when checking to see if an
-       address could be batched with a previous (undelivered) one; under
-       certain circumstances this could lead to multiple deliveries to the same
-       address. A one-line patch to add the appropriate test fixes the bug.
-
-PH/05. Renamed the macro SOCKLEN_T as EXIM_SOCKLEN_T because AIX uses SOCKLEN_T
-       in its include files, and this causes problems building Exim.
-
-PH/06. A number of "verify =" ACL conditions have no options (e.g. verify =
-       header_syntax) but Exim was just ignoring anything given after a slash.
-       In particular, this caused confusion with an attempt to use "verify =
-       reverse_host_lookup/defer_ok". An error is now given when options are
-       supplied for verify items that do not have them. (Maybe reverse_host_
-       lookup should have a defer_ok option, but that's a different point.)
-
-PH/07. Increase the size of the buffer for incoming SMTP commands from 512 (as
-       defined by RFC 821) to 2048, because there were problems with some AUTH
-       commands, and RFC 1869 says the size should be increased for extended
-       SMTP commands that take arguments.
+TK/01 Added Yahoo DomainKeys support via libdomainkeys. See
+      doc/experimental-spec.txt for details. (http://domainkeys.sf.net)
+
+TK/02 Fix ACL "control" statment not being available in MIME ACL.
+
+TK/03 Fix ACL "regex" condition not being available in MIME ACL.
+
+PH/01 Installed a patch from the Sieve maintainer that allows -bf to be used
+      to test Sieve filters that use "vacation".
+
+PH/02 Installed a slightly modified version of Nikos Mavrogiannopoulos' patch
+      that changes the way the GnuTLS parameters are stored in the cache file.
+      The new format can be generated externally. For backward compatibility,
+      if the data in the cache doesn't make sense, Exim assumes it has read an
+      old-format file, and it generates new data and writes a new file. This
+      means that you can't go back to an older release without removing the
+      file.
+
+PH/03 A redirect router that has both "unseen" and "one_time" set does not
+      work if there are any delivery delays because "one_time" forces the
+      parent to be marked "delivered", so its unseen clone is never tried
+      again. For this reason, Exim now forbids the simultaneous setting of
+      these two options.
+
+PH/04 Change 4.11/85 fixed an obscure bug concerned with addresses that are
+      redirected to themselves ("homonym" addresses). Read the long ChangeLog
+      entry if you want to know the details. The fix, however, neglected to
+      consider the case when local delivery batching is involved. The test for
+      "previously delivered" was not happening when checking to see if an
+      address could be batched with a previous (undelivered) one; under
+      certain circumstances this could lead to multiple deliveries to the same
+      address. A one-line patch to add the appropriate test fixes the bug.
+
+PH/05 Renamed the macro SOCKLEN_T as EXIM_SOCKLEN_T because AIX uses SOCKLEN_T
+      in its include files, and this causes problems building Exim.
+
+PH/06 A number of "verify =" ACL conditions have no options (e.g. verify =
+      header_syntax) but Exim was just ignoring anything given after a slash.
+      In particular, this caused confusion with an attempt to use "verify =
+      reverse_host_lookup/defer_ok". An error is now given when options are
+      supplied for verify items that do not have them. (Maybe reverse_host_
+      lookup should have a defer_ok option, but that's a different point.)
+
+PH/07 Increase the size of the buffer for incoming SMTP commands from 512 (as
+      defined by RFC 821) to 2048, because there were problems with some AUTH
+      commands, and RFC 1869 says the size should be increased for extended
+      SMTP commands that take arguments.
+
+PH/08 Added ${dlfunc dynamically loaded function for expansion (code from Tony
+      Finch).
+
+PH/09 Previously, an attempt to use ${perl when it wasn't compiled gave an
+      "unknown" error; now it says that the functionality isn't in the binary.
 
 
 A note about Exim versions 4.44 and 4.50
diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index 827c5d1dc..383c0f6f4 100644
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -1,4 +1,4 @@
-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.27 2005/03/08 11:38:21 ph10 Exp $
+$Cambridge: exim/doc/doc-txt/NewStuff,v 1.28 2005/03/22 14:11:54 ph10 Exp $
 
 New Features in Exim
 --------------------
@@ -12,32 +12,72 @@ file contains a listing of all changes, including bug fixes.
 Version 4.51
 ------------
 
-PH/01. The format in which GnuTLS parameters are written to the gnutls-param
-       file in the spool directory has been changed. This change has been made
-       to alleviate problems that some people had with the generation of the
-       parameters by Exim when /dev/random was exhausted. In this situation,
-       Exim would hang until /dev/random acquired some more entropy.
-
-       The new code exports and imports the DH and RSA parameters in PEM
-       format. This means that the parameters can be generated externally using
-       the certtool command that is part of GnuTLS.
-
-       To replace the parameters with new ones, instead of deleting the file
-       and letting Exim re-create it, you can generate new parameters using
-       certtool and, when this has been done, replace Exim's cache file by
-       renaming. The relevant commands are something like this:
-
-         # rm -f new.params
-         # touch new.params
-         # chown exim:exim new.params
-         # chmod 0400 new.params
-         # certtool --generate-privkey --bits 512 >new.params
-         # echo "" >>new.params
-         # certtool --generate-dh-params --bits 1024 >> new.params
-         # mv new.params params
-
-       If Exim never has to generate the parameters itself, the possibility of
-       stalling is removed.
+PH/01 The format in which GnuTLS parameters are written to the gnutls-param
+      file in the spool directory has been changed. This change has been made
+      to alleviate problems that some people had with the generation of the
+      parameters by Exim when /dev/random was exhausted. In this situation,
+      Exim would hang until /dev/random acquired some more entropy.
+
+      The new code exports and imports the DH and RSA parameters in PEM
+      format. This means that the parameters can be generated externally using
+      the certtool command that is part of GnuTLS.
+
+      To replace the parameters with new ones, instead of deleting the file
+      and letting Exim re-create it, you can generate new parameters using
+      certtool and, when this has been done, replace Exim's cache file by
+      renaming. The relevant commands are something like this:
+
+        # rm -f new.params
+        # touch new.params
+        # chown exim:exim new.params
+        # chmod 0400 new.params
+        # certtool --generate-privkey --bits 512 >new.params
+        # echo "" >>new.params
+        # certtool --generate-dh-params --bits 1024 >> new.params
+        # mv new.params params
+
+      If Exim never has to generate the parameters itself, the possibility of
+      stalling is removed.
+
+PH/02 A new expansion item for dynamically loading and calling a locally-
+      written C function is now provided, if Exim is compiled with
+
+        EXPAND_DLFUNC=yes
+
+      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:
+
+        ${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).
+
+      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
+      included. The Exim variables and functions that are defined by that API
+      are also available for dynamically loaded functions. The function itself
+      must have the following type:
+
+        int dlfunction(uschar **yield, int argc, uschar *argv[])
+
+      Where "uschar" is a typedef for "unsigned char" in local_scan.h. The
+      function should return one of the following values:
+
+      OK            Success. The string that is placed in "yield" is put into
+                    the expanded string that is being built.
+
+      FAIL          A non-forced expansion failure occurs, with the error
+                    message taken from "yield", if it is set.
+
+      FAIL_FORCED   A forced expansion failure occurs, with the error message
+                    taken from "yield" if it is set.
+
+      ERROR         Same as FAIL, except that a panic log entry is written.
+
+      When compiling a function that is to be used in this way with gcc,
+      you need to add -shared to the gcc command. Also, in the Exim build-time
+      configuration, you must add -export-dynamic to EXTRALIBS.
 
 
 Version 4.50