X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/e5a9dba621b4301bfbe2bc05576ddc5ec752b1b5..2632889eca3018763375f85b31212712044c395f:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 98c6fe258..7627fb7f9 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,4 +1,4 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.40 2005/05/10 10:19:11 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.88 2006/02/21 16:24:19 ph10 Exp $ New Features in Exim -------------------- @@ -8,243 +8,88 @@ but have not yet made it into the main manual (which is most conveniently updated when there is a relatively large batch of changes). The doc/ChangeLog 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 4.61 ------------ -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 +PH/01 There is a new global option called disable_ipv6, which does exactly what + its name implies. If set true, even if the Exim binary has IPv6 support, + no IPv6 activities take place. AAAA records are never looked up for host + names given in manual routing data or elsewhere. AAAA records that are + received from the DNS as additional data for MX records are ignored. Any + IPv6 addresses that are listed in local_interfaces, manualroute route + data, etc. are also ignored. If IP literals are enabled, the ipliteral + router declines to handle IPv6 literal addresses. + +PH/02 There are now 20 of each type of ACL variable by default (instead of 10). + It is also possible to change the numbers by setting ACL_CVARS and/or + ACL_MVARS in Local/Makefile. Backward compatibility is maintained if you + upgrade to this release with existing messages containing ACL variable + settings on the queue. However, going in the other direction + (downgrading) will not be compatible; the values of ACL variables will be + lost. + +PH/03 If quota_warn_message contains a From: header, Exim now refrains from + adding the default one. Similarly, if it contains a Reply-To: header, the + errors_reply_to option, if set, is not used. + +PH/04 The variables $auth1, $auth2, $auth3 are now available in authenticators, + containing the same values as $1, $2, $3. The new variables are provided + because the numerical variables can be reset during string expansions + (for example, during a "match" operation) and so may lose the + authentication data. The preferred variables are now the new ones, with + the use of the numerical ones being deprecated, though the support will + not be removed, at least, not for a long time. + +PH/05 The "control=freeze" ACL modifier can now be followed by /no_tell. If + the global option freeze_tell is set, it is ignored for the current + message (that is, nobody is told about the freezing), provided all the + "control=freeze" modifiers that are obeyed in the current message have + the /no_tell option. + +PH/06 In both GnuTLS and OpenSSL, an expansion of tls_privatekey that results + in an empty string is now treated as unset. + +PH/07 There is a new log selector called sender_verify_fail, which is set by + default. If it is unset, the separate log line that gives details of a + sender verification failure is not written. Log lines for the rejection + of SMTP commands (e.g. RCPT) contain just "sender verify failed", so some + detail is lost. + +PH/08 The default for dns_check_names_pattern now allows slashes within names, + as there are now some PTR records that contain slashes. This check is + only to protect against broken name servers that fall over on strange + characters, so the fact that it applies to all lookups doesn't matter. + +PH/09 The default for rfc4131_query_timeout has been changed from 30s to 5s. + +PH/10 When compiled on FreeBSD, NetBSD, or BSD/OS, the pipe transport has a new + Boolean option called use_classresources, defaulting false. If it is set + true, the setclassresources() function is used to set resource limits + when a pipe transport is run to perform a delivery. The limits for the + uid under which the pipe is to run are obtained from the login class + database. + + +Version 4.60 +------------ - If Exim never has to generate the parameters itself, the possibility of - stalling is removed. +The documentation is up-to-date for the 4.60 release. Major new features since +the 4.50 release are: -PH/02 A new expansion item for dynamically loading and calling a locally- - written C function is now provided, if Exim is compiled with +. Support for SQLite. - EXPAND_DLFUNC=yes +. Support for IGNOREQUOTA in LMTP. - 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.) +. Extensions to the "submission mode" features. - 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. +. Support for Client SMTP Authorization (CSA). - 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. - -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: +. Support for ratelimiting hosts and users. - warn !verify = sender - set acl_m0 = $acl_verify_message +. New expansion items to help with the BATV "prvs" scheme. - 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 ------------- +. A "match_ip" condition, that matches an IP address against a list. -The documentation is up-to-date for the 4.50 release. +There are many more minor changes. ****