X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/b5aea5e16720f8b17bcbbf54af966ba034432db9..74e0617f5ad5aa05f6e19f7b7cf6ecfe039749f6:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 827c5d1dc..053bdabab 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 1.30 2005/03/22 16:52:06 ph10 Exp $ New Features in Exim -------------------- @@ -12,33 +12,84 @@ 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.) + + 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}...} + + 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 + 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. + +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. Version 4.50 ------------