X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/c38d6da94aa327f7c42a90b50508c62702412fef..ebe2da9781157d14b0c9e91f08e93bd67755f0dd:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index b4fda862d..827c5d1dc 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,4 +1,4 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.19 2004/11/25 14:31:28 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.27 2005/03/08 11:38:21 ph10 Exp $ New Features in Exim -------------------- @@ -9,808 +9,40 @@ updated when there is a relatively large batch of changes). The doc/ChangeLog file contains a listing of all changes, including bug fixes. -Version 4.44 +Version 4.51 ------------ - 1. There is a new build-time option called CONFIGURE_GROUP which works like - CONFIGURE_OWNER. It specifies one additional group that is permitted for - the runtime configuration file when the group write permission is set. +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. - 2. The "control=submission" facility has a new option /sender_retain. This - has the effect of setting local_sender_retain true and local_from_check - false for the incoming message in which it is encountered. + 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. - 3. $recipients is now available in the predata ACL (oversight). + 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: - 4. The value of address_data from a sender verification is now available in - $sender_address_data in subsequent conditions in the ACL statement. Note: - this is just like $address_data. The value does not persist after the end - of the current ACL statement. If you want to preserve it, you can use one - of the ACL variables. + # 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 - 5. The redirect router has two new options: forbid_sieve_filter and - forbid_exim_filter. When filtering is enabled by allow_filter, these - options control which type(s) of filtering are permitted. By default, both - Exim and Sieve filters are allowed. + If Exim never has to generate the parameters itself, the possibility of + stalling is removed. - 6. A new option for callouts makes it possible to set a different (usually - smaller) timeout for making the SMTP connection. The keyword is "connect". - For example: - verify = sender/callout=5s,connect=1s - - If not specified, it defaults to the general timeout value. - - 7. The new variables $sender_verify_failure and $recipient_verify_failure - contain information about exactly what failed. In an ACL, after one of - these failures, the relevant variable contains one of the following words: - - qualify the address was unqualified (no domain), and the message - was neither local nor came from an exempted host; - - route routing failed; - - mail routing succeeded, and a callout was attempted; rejection - occurred at or before the MAIL command (that is, on initial - connection, HELO, or MAIL); - - recipient the RCPT command in a callout was rejected; - - postmaster the postmaster check in a callout was rejected. - - The main use of these variables is expected to be to distinguish between - rejections of MAIL and rejections of RCPT. - - 8. The command line option -dd behaves exactly like -d except when used on a - command that starts a daemon process. In that case, debugging is turned off - for the subprocesses that the daemon creates. Thus, it is useful for - monitoring the behaviour of the daemon without creating as much output as - full debugging. - - 9. $host_address is now set to the target address during the checking of - ignore_target_hosts. - -10. There are four new variables called $spool_space, $log_space, - $spool_inodes, and $log_inodes. The first two contain the amount of free - space in the disk partitions where Exim has its spool directory and log - directory, respectively. (When these are in the same partition, the values - will, of course, be the same.) The second two variables contain the numbers - of free inodes in the respective partitions. - - NOTE: Because disks can nowadays be very large, the values in the space - variables are in kilobytes rather than in bytes. Thus, for example, to - check in an ACL that there is at least 50M free on the spool, you would - write: - - condition = ${if > {$spool_space}{50000}{yes}{no}} - - The values are recalculated whenever any of these variables is referenced. - If the relevant file system does not have the concept of inodes, the value - of those variables is -1. If the operating system does not have the ability - to find the amount of free space (only true for experimental systems), the - space value is -1. - -11. It is now permitted to omit both strings after an "if" condition; if the - condition is true, the result is the string "true". As before, when the - second string is omitted, a false condition yields an empty string. This - makes it less cumbersome to write custom ACL and router conditions. For - example, instead of - - condition = ${if eq {$acl_m4}{1}{yes}{no}} - - or the shorter form - - condition = ${if eq {$acl_m4}{1}{yes}} - - (because the second string has always defaulted to ""), you can now write - - condition = ${if eq {$acl_m4}{1}} - - Previously this was a syntax error. - -12. There is a new "record type" that can be specified in dnsdb lookups. It - is "zns" (for "zone NS"). It performs a lookup for NS records on the given - domain, but if none are found, it removes the first component of the domain - name, and tries again. This process continues until NS records are found - or there are no more components left (or there's a DNS error). In other - words, it may return the name servers for a top-level domain, but it never - returns the root name servers. If there are no NS records for the top-level - domain, the lookup fails. - - For example, ${lookup dnsdb{zns=xxx.quercite.com}} returns the name - servers for quercite.com, whereas ${lookup dnsdb{zns=xxx.edu}} returns - the name servers for edu, assuming in each case that there are no NS - records for the full domain name. - - You should be careful about how you use this lookup because, unless the - top-level domain does not exist, the lookup will always return some host - names. The sort of use to which this might be put is for seeing if the name - servers for a given domain are on a blacklist. You can probably assume that - the name servers for the high-level domains such as .com or .co.uk are not - going to be on such a list. - -13. Another new "record type" is "mxh"; this looks up MX records just as "mx" - does, but it returns only the names of the hosts, omitting the priority - values. - -14. It is now possible to specify a list of domains or IP addresses to be - looked up in a dnsdb lookup. The list is specified in the normal Exim way, - with colon as the default separator, but with the ability to change this. - For example: - - ${lookup dnsdb{one.domain.com:two.domain.com}} - ${lookup dnsdb{a=one.host.com:two.host.com}} - ${lookup dnsdb{ptr = <; 1.2.3.4 ; 4.5.6.8}} - - In order to retain backwards compatibility, there is one special case: if - the lookup type is PTR and no change of separator is specified, Exim looks - to see if the rest of the string is precisely one IPv6 address. In this - case, it does not treat it as a list. - - The data from each lookup is concatenated, with newline separators (by - default - see 14 below), in the same way that multiple DNS records for a - single item are handled. - - The dnsdb lookup fails only if all the DNS lookups fail. If there is a - temporary DNS error for any of them, the remaining lookups are still done, - and only if none of them succeed does the dnsdb lookup defer. As long as at - least one of the DNS lookups yields some data, the dnsdb lookup succeeds. - -15. It is now possible to specify the character to be used as a separator when - a dnsdb lookup returns data from more than one DNS record. The default is a - newline. To specify a different character, put '>' followed by the new - character at the start of the query. For example: - - ${lookup dnsdb{>: a=h1.test.ex:h2.test.ex}} - ${lookup dnsdb{>| mxh=<;m1.test.ex;m2.test.ex}} - - It is permitted to specify a space as the separator character. Note that - more than one DNS record can be found for a single lookup item; this - feature is relevant even when you do not specify a list. - - The same effect could be achieved by wrapping the lookup in ${tr...}; this - feature is just a syntactic simplification. - -16. It is now possible to supply a list of domains and/or IP addresses to be - lookup up in a DNS blacklist. Previously, only a single domain name could - be given, for example: - - dnslists = black.list.tld/$sender_host_name - - What follows the slash can now be a list. As with all lists, the default - separator is a colon. However, because this is a sublist within the list of - DNS blacklist domains, it is necessary either to double the separators like - this: - - dnslists = black.list.tld/name.1::name.2 - - or to change the separator character, like this: - - dnslists = black.list.tld/<;name.1;name.2 - - If an item in the list is an IP address, it is inverted before the DNS - blacklist domain is appended. If it is not an IP address, no inversion - occurs. Consider this condition: - - dnslists = black.list.tls/<;192.168.1.2;a.domain - - The DNS lookups that occur are for - - 2.1.168.192.black.list.tld and a.domain.black.list.tld - - Once a DNS record has been found (that matches a specific IP return - address, if specified), no further lookups are done. If there is a - temporary DNS error, the rest of the sublist of domains or IP addresses is - tried. The dnslists item itself defers only if none of the other DNS - lookups in this sublist succeeds. In other words, a successful lookup for - any of the items in the sublist overrides a defer for a previous item. - -17. The log selector queue_time_overall causes Exim to output the time spent on - the queue as an addition to the "Completed" message. Like queue_time (which - puts the queue time on individual delivery lines), the time is tagged with - "QT=", and it is measured from the time that the message starts to be - received, so it includes the reception time. - -18. It is now possible to use both -bF and -bf on the same command, in order to - test a system filter and a user filter in the same run. For example: - - exim -bF /system/filter -bf /user/filter } to the expansion operators. This operator - converts an arbitrary string into one that is base64 encoded. - -10. A new authenticator, called cyrus_sasl, has been added. This requires - the presence of the Cyrus SASL library; it authenticates by calling this - library, which supports a number of authentication mechanisms, including - PLAIN and LOGIN, but also several others that Exim does not support - directly. The code for this authenticator was provided by Matthew - Byng-Maddick of A L Digital Ltd (http://www.aldigital.co.uk). Here follows - draft documentation: - - xx. THE CYRUS_SASL AUTHENTICATOR - - The cyrus_sasl authenticator provides server support for the Cyrus library - Implementation of the RFC 2222 "Simple Authentication and Security Layer". - It provides a gatewaying mechanism directly to the Cyrus interface, so if - your Cyrus library can do, for example, CRAM-MD5, then so can the - cyrus_sasl authenticator. By default it uses the public name of the driver - to determine which mechanism to support. - - Where access to some kind of secret file is required, for example in GSSAPI - or CRAM-MD5, it is worth noting that the authenticator runs as the exim - user, and that the Cyrus SASL library has no way of escalating privileges - by default. You may also find you need to set environment variables, - depending on the driver you are using. - - xx.1 Using cyrus_sasl as a server - - The cyrus_sasl authenticator has four private options. It puts the username - (on a successful authentication) into $1. - - server_hostname Type: string* Default: $primary_hostname - - This option selects the hostname that is used when communicating with - the library. It is up to the underlying SASL plug-in what it does with - this data. - - server_mech Type: string Default: public_name - - This option selects the authentication mechanism this driver should - use. It allows you to use a different underlying mechanism from the - advertised name. For example: - - sasl: - driver = cyrus_sasl - public_name = X-ANYTHING - server_mech = CRAM-MD5 - server_set_id = $1 - - server_realm Type: string Default: unset - - This is the SASL realm that the server is claiming to be in. - - server_service Type: string Default: "smtp" - - This is the SASL service that the server claims to implement. - - For straigthforward cases, you do not need to set any of the - authenticator's private options. All you need to do is to specify an - appropriate mechanism as the public name. Thus, if you have a SASL library - that supports CRAM-MD5 and PLAIN, you might have two authenticators as - follows: - - sasl_cram_md5: - driver = cyrus_sasl - public_name = CRAM-MD5 - server_set_id = $1 - - sasl_plain: - driver = cyrus_sasl - public_name = PLAIN - server_set_id = $1 - -11. There is a new global option called tls_on_connect_ports. Its value must be - a list of port numbers; the most common use is expected to be - - tls_on_connect_ports = 465 - - Setting this option has the same effect as -tls-on-connect on the command - line, but only for the specified ports. It applies to all connections, both - via the daemon and via inetd. You still need to specify all the ports for - the daemon (using daemon_smtp_ports or local_interfaces or the -X command - line option) because this option does not add an extra port -- rather, it - specifies different behaviour on a port that is defined elsewhere. The - -tls-on-connect command line option overrides tls_on_connect_ports, and - forces tls-on-connect for all ports. - -12. There is a new ACL that is run when a DATA command is received, before the - data itself is received. The ACL is defined by acl_smtp_predata. (Compare - acl_smtp_data, which is run after the data has been received.) - This new ACL allows a negative response to be given to the DATA command - itself. Header lines added by MAIL or RCPT ACLs are not visible at this - time, but any that are defined here are visible when the acl_smtp_data ACL - is run. - -13. The "control=submission" ACL modifier has an option "/domain=xxx" which - specifies the domain to be used when creating From: or Sender: lines using - the authenticated id as a local part. If the option is supplied with an - empty domain, that is, just "/domain=", Exim assumes that the authenticated - id is a complete email address, and it uses it as is when creating From: - or Sender: lines. - -14. It is now possible to make retry rules that apply only when the failing - message has a specific sender. In particular, this can be used to define - retry rules that apply only to bounce messages. The syntax is to add a new - third item to a retry rule, of the form "senders=
". The retry - timings themselves then become the fourth item. For example: - - * * senders=: F,1h,30m - - would match all bounce messages. If the address list contains white space, - it must be enclosed in quotes. For example: - - a.domain timeout senders="x@b.dom : y@c.dom" G,8h,10m,1.5 - - When testing retry rules using -brt, you can supply a sender using the -f - command line option, like this: - - exim -f "" -brt user@dom.ain - - If you do not set -f with -brt, a retry rule that contains a senders list - will never be matched. - -15. Two new control modifiers have been added to ACLs: "control = enforce_sync" - and "control = no_enforce_sync". This makes it possible to be selective - about when SMTP synchronization is enforced. The global option - smtp_enforce_sync now specifies the default state of the switch. These - controls can appear in any ACL, but the most obvious place to put them is - in the ACL defined by acl_smtp_connect, which is run at the start of an - incoming SMTP connection, before the first synchronization check. - -16. Another two new control modifiers are "control = caseful_local_part" and - "control = caselower_local_part". These are permitted only in the ACL - specified by acl_smtp_rcpt (i.e. during RCPT processing). By default, the - contents of $local_part are lower cased before ACL processing. - After "control = caseful_local_part", any uppercase letters in the original - local part are restored in $local_part for the rest of the ACL, or until - "control = caselower_local_part" is encountered. However, this applies only - to local part handling that takes place directly in the ACL (for example, - as a key in lookups). If a "verify = recipient" test is obeyed, the - case-related handling of the local part during the verification is - controlled by the router configuration (see the caseful_local_part generic - router option). - - This facility could be used, for example, to add a spam score to local - parts containing upper case letters. For example, using $acl_m4 to - accumulate the spam score: - - warn control = caseful_local_part - set acl_m4 = ${eval:\ - $acl_m4 + \ - ${if match{$local_part}{[A-Z]}{1}{0}}\ - } - control = caselower_local_part - - Notice that we put back the lower cased version afterwards, assuming that - is what is wanted for subsequent tests. - -17. The option hosts_connection_nolog is provided so that certain hosts can be - excepted from logging when the +smtp_connection log selector is set. For - example, you might want not to log SMTP connections from local processes, - or from 127.0.0.1, or from your local LAN. The option is a host list with - an unset default. Because it is consulted in the main loop of the daemon, - you should strive to restrict its value to a short inline list of IP - addresses and networks. To disable logging SMTP connections from local - processes, you must create a host list with an empty item. For example: - - hosts_connection_nolog = : - - If the +smtp_connection log selector is not set, this option has no effect. - -18. There is now an acl called acl_smtp_quit, which is run for the QUIT - command. The outcome of the ACL does not affect the response code to QUIT, - which is always 221. Thus, the ACL does not in fact control any access. - For this reason, the only verbs that are permitted are "accept" and "warn". - - The ACL can be used for tasks such as custom logging at the end of an SMTP - session. For example, you can use ACL variables in other ACLs to count - messages, recipients, etc., and log the totals at QUIT time using one or - more "logwrite" modifiers on a "warn" command. - - You do not need to have a final "accept", but if you do, you can use a - "message" modifier to specify custom text that is sent as part of the 221 - response. - - This ACL is run only for a "normal" QUIT. For certain kinds of disastrous - failure (for example, failure to open a log file, or when Exim is bombing - out because it has detected an unrecoverable error), all SMTP commands - from the client are given temporary error responses until QUIT is received - or the connection is closed. In these special cases, the ACL is not run. - -19. The appendfile transport has two new options, mailbox_size and mailbox_ - filecount. If either these options are set, it is expanded, and the result - is taken as the current size of the mailbox or the number of files in the - mailbox, respectively. This makes it possible to use some external means of - maintaining the data about the size of a mailbox for enforcing quota - limits. The result of expanding these option values must be a decimal - number, optionally followed by "K" or "M". - -20. It seems that there are broken clients in use that cannot handle multiline - SMTP responses. Can't people who implement these braindead programs read? - RFC 821 mentions multiline responses, and it is over 20 years old. They - must handle multiline responses for EHLO, or do they still use HELO? - Anyway, here is YAWFAB (yet another workaround for asinine brokenness). - There's a new ACL switch that can be set by - - control = no_multiline_responses - - If this is set, it suppresses multiline SMTP responses from ACL rejections. - One way of doing this would have been just to put out these responses as - one long line. However, RFC 2821 specifies a maximum of 512 bytes per - response ("use multiline responses for more" it says), and some of the - responses might get close to that. So I have implemented this by doing two - very easy things: - - (1) Extra information that is normally output as part of a rejection - caused by sender verification failure is omitted. Only the final line - (typically "sender verification failed") is now sent. - - (2) If a "message" modifier supplies a multiline response, only the first - line is output. - - The setting of the switch can, of course, be made conditional on the - calling host. - -21. There is now support for the libradius library that comes with FreeBSD. - This is an alternative to the radiusclient library that Exim already - supports. To use the FreeBSD library, you need to set - - RADIUS_LIB_TYPE=RADLIB - - in Local/Makefile, in addition to RADIUS_CONFIGURE_FILE, and you probably - also need -libradius in EXTRALIBS. - - -Version 4.42 ------------- - - 1. The "personal" filter test is brought up-to-date with recommendations from - the Sieve specification: (a) The list of non-personal From: addresses now - includes "listserv", "majordomo", and "*-request"; (b) If the message - contains any header line starting with "List=-" it is treated as - non-personal. - - 2. The Sieve functionality has been extended to support the "copy" and - "vacation" extensions, and comparison tests. - - 3. There is now an overall timeout for performing a callout verification. It - defaults to 4 times the callout timeout, which applies to individual SMTP - commands during the callout. The overall timeout applies when there is more - than one host that can be tried. The timeout is checked before trying the - next host. This prevents very long delays if there are a large number of - hosts and all are timing out (e.g. when the network connections are timing - out). The value of the overall timeout can be changed by specifying an - additional sub-option for "callout", called "maxwait". For example: - - verify = sender/callout=5s,maxwait=20s - - 4. Changes to the "personal" filter test: - - (1) The list of non-personal local parts in From: addresses has been - extended to include "listserv", "majordomo", "*-request", and "owner-*", - taken from the Sieve specification recommendations. - - (2) If the message contains any header line starting with "List-" it is - treated as non-personal. - - (3) The test for "circular" in the Subject: header line has been removed - because it now seems ill-conceived. - - 5. The autoreply transport has a new option called never_mail. This is an - address list. If any run of the transport creates a message with a - recipient that matches any item in the list, that recipient is quietly - discarded. If all recipients are discarded, no message is created. - - -Version 4.40 ------------- - -The documentation is up-to-date for the 4.40 release. What follows here is a -brief list of the new features that have been added since 4.30. - - 1. log_incoming_interface affects more log lines. - - 2. New ACL modifier "control = submission". - - 3. CONFIGURE_OWNER can be set at build time to define an alternative owner for - the configuration file, in addition to root and exim. - - 4. Added expansion variables $body_zerocount, $recipient_data, and - $sender_data. - - 5. The time of last modification of the "new" subdirectory is now used as the - "mailbox time last read" when there is a quota error for a maildir - delivery. - - 6. The special item "+ignore_unknown" may now appear in host lists. - - 7. The special domain-matching patterns @mx_any, @mx_primary, and - @mx_secondary can now be followed by "/ignore=". - - 8. New expansion conditions: match_domain, match_address, match_local_part, - lt, lti, le, lei, gt, gti, ge, and new expansion operators time_interval, - eval10, and base62d. - - 9. New lookup type called "iplsearch". - -10. New log selectors ident_timeout, tls_certificate_verified, queue_time, - deliver_time, outgoing_port, return_path_on_delivery. - -11. New global options smtp_active_hostname and tls_require_ciphers. - -12. Exinext has -C and -D options. - -13. "domainlist_cache" forces caching of an apparently variable list. - -14. For compatibility with Sendmail, the command line option -prval:sval - is equivalent to -oMr rval -oMs sval. - -15. New callout options use_sender and use_postmaster for use when verifying - recipients. - -16. John Jetmore's "exipick" utility has been added to the distribution. - -17. The TLS code now supports CRLs. - -18. The dnslookup router and the dnsdb lookup type now support the use of SRV - records. - -19. The redirect router has a new option called qualify_domain. - -20. exigrep's output now also includes lines that are not related to any - particular message, but which do match the pattern. - -21. New global option write_rejectlog. If it is set false, Exim no longer - writes anything to the reject log. +The documentation is up-to-date for the 4.50 release. ****