X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/f7b639017a889d802b26b61df6b3f1ac46c6f4f0..431b736177e2cdfd0b4da4c8545d8b732286abe1:/doc/doc-txt/NewStuff?ds=inline diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 16c9c4653..960f93ce8 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,819 +1,282 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.20 2004/12/17 14:52:44 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.127 2007/01/17 11:17:58 ph10 Exp $ New Features in Exim -------------------- -This file contains descriptions of new features that have been added to Exim, -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. +This file contains descriptions of new features that have been added to Exim. +Before a formal release, there may be quite a lot of detail so that people can +test from the snapshots or the CVS before the documentation is updated. Once +the documentation is updated, this file is reduced to a short list. - -Version 4.50 +Version 4.67 ------------ - 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. - - 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. - - 3. $recipients is now available in the predata ACL (oversight). - - 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. - - 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. - - 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; + 1. There is a new log selector called smtp_no_mail, which is not included in + the default setting. When it is set, a line is written to the main log + whenever an accepted SMTP connection terminates without having issued a + MAIL command. This includes both the case when the connection is dropped, + and the case when QUIT is used. Note that it does not include cases where + the connection is rejected right at the start (by an ACL, or because there + are too many connections, or whatever). These cases already have their own + log lines. - route routing failed; + The log line that is written contains the identity of the client in the + usual way, followed by D= and a time, which records the duration of the + connection. If the connection was authenticated, this fact is logged + exactly as it is for an incoming message, with an A= item. If the + connection was encrypted, CV=, DN=, and X= items may appear as they do for + an incoming message, controlled by the same logging options. - mail routing succeeded, and a callout was attempted; rejection - occurred at or before the MAIL command (that is, on initial - connection, HELO, or MAIL); + Finally, if any SMTP commands were issued during the connection, a C= item + is added to the line, listing the commands that were used. For example, - recipient the RCPT command in a callout was rejected; + C=EHLO,QUIT - postmaster the postmaster check in a callout was rejected. + shows that the client issued QUIT straight after EHLO. If there were fewer + than 20 commands, they are all listed. If there were more than 20 commands, + the last 20 are listed, preceded by "...". However, with the default + setting of 10 for smtp_accep_max_nonmail, the connection will in any case + be aborted before 20 non-mail commands are processed. - The main use of these variables is expected to be to distinguish between - rejections of MAIL and rejections of RCPT. + 2. When an item in a dnslists list is followed by = and & and a list of IP + addresses, in order to restrict the match to specific results from the DNS + lookup, the behaviour was not clear when the lookup returned more than one + IP address. For example, consider the condition - 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. + dnslists = a.b.c=127.0.0.1 - 9. $host_address is now set to the target address during the checking of - ignore_target_hosts. + What happens if the DNS lookup for the incoming IP address yields both + 127.0.0.1 and 127.0.0.2 by means of two separate DNS records? Is the + condition true because at least one given value was found, or is it false + because at least one of the found values was not listed? And how does this + affect negated conditions? -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. + The behaviour of = and & has not been changed; however, the text below + documents it more clearly. In addition, two new additional conditions (== + and =&) have been added, to permit the "other" behaviour to be configured. - 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: + A DNS lookup may yield more than one record. Thus, the result of the lookup + for a dnslists check may yield more than one IP address. The question then + arises as to whether all the looked up addresses must be listed, or whether + just one is good enough. Both possibilities are provided for: - condition = ${if > {$spool_space}{50000}{yes}{no}} + . If = or & is used, the condition is true if any one of the looked up + IP addresses matches one of the listed addresses. Consider: - 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. + dnslists = a.b.c=127.0.0.1 -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 + If the DNS lookup yields both 127.0.0.1 and 127.0.0.2, the condition is + true because 127.0.0.1 matches. - condition = ${if eq {$acl_m4}{1}{yes}{no}} + . If == or =& is used, the condition is true only if every one of the + looked up IP addresses matches one of the listed addresses. Consider: - or the shorter form + dnslists = a.b.c==127.0.0.1 - condition = ${if eq {$acl_m4}{1}{yes}} + If the DNS lookup yields both 127.0.0.1 and 127.0.0.2, the condition is + false because 127.0.0.2 is not listed. You would need to have - (because the second string has always defaulted to ""), you can now write + dnslists = a.b.c==127.0.0.1,127.0.0.2 - condition = ${if eq {$acl_m4}{1}} + for the condition to be true. - Previously this was a syntax error. + When ! is used to negate IP address matching, it inverts the result, giving + the precise opposite of the behaviour above. Thus: -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. + . If != or !& is used, the condition is true if none of the looked up IP + addresses matches one of the listed addresses. Consider: - 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. + dnslists = a.b.c!&0.0.0.1 - 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. + If the DNS lookup yields both 127.0.0.1 and 127.0.0.2, the condition is + false because 127.0.0.1 matches. -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. + . If !== or !=& is used, the condition is true there is at least one looked + up IP address that does not match. Consider: -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: + dnslists = a.b.c!=&0.0.0.1 - ${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}} + If the DNS lookup yields both 127.0.0.1 and 127.0.0.2, the condition is + true, because 127.0.0.2 does not match. You would need to have - 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. + dnslists = a.b.c!=&0.0.0.1,0.0.0.2 - 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. + for the condition to be false. - 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. + When the DNS lookup yields only a single IP address, there is no difference + between = and == and between & and =&. -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}} +Version 4.66 +------------ - 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. +No new features were added to 4.66. - The same effect could be achieved by wrapping the lookup in ${tr...}; this - feature is just a syntactic simplification. -16. It is now possible to supply a list of domains and/or IP addresses to be - lookup up in a DNS blacklist. Previously, only a single domain name could - be given, for example: +Version 4.65 +------------ - dnslists = black.list.tld/$sender_host_name +No new features were added to 4.65. - 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 +Version 4.64 +------------ - or to change the separator character, like this: + 1. ACL variables can now be given arbitrary names, as long as they start with + "acl_c" or "acl_m" (for connection variables and message variables), are at + least six characters long, with the sixth character being either a digit or + an underscore. - dnslists = black.list.tld/<;name.1;name.2 + 2. There is a new ACL modifier called log_reject_target. It makes it possible + to specify which logs are used for messages about ACL rejections. - 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: + 3. There is a new authenticator called "dovecot". This is an interface to the + authentication facility of the Dovecot POP/IMAP server, which can support a + number of authentication methods. - dnslists = black.list.tls/<;192.168.1.2;a.domain + 4. The variable $message_headers_raw provides a concatenation of all the + messages's headers without any decoding. This is in contrast to + $message_headers, which does RFC2047 decoding on the header contents. - The DNS lookups that occur are for + 5. In a DNS black list, if two domain names, comma-separated, are given, the + second is used first to do an initial check, making use of any IP value + restrictions that are set. If there is a match, the first domain is used, + without any IP value restrictions, to get the TXT record. - 2.1.168.192.black.list.tld and a.domain.black.list.tld + 6. All authenticators now have a server_condition option. - 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. + 7. There is a new command-line option called -Mset. It is useful only in + conjunction with -be (that is, when testing string expansions). It must be + followed by a message id; Exim loads the given message from its spool + before doing the expansions. -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. + 8. Another similar new command-line option is called -bem. It operates like + -be except that it must be followed by the name of a file that contains a + message. -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: + 9. When an address is delayed because of a 4xx response to a RCPT command, it + is now the combination of sender and recipient that is delayed in + subsequent queue runs until its retry time is reached. - 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. There is a new Boolean option called filter_prepend_home for the redirect + router. + +2. There is a new acl, set by acl_not_smtp_start, which is run right at the + start of receiving a non-SMTP message, before any of the message has been + read. + +3. When an SMTP error message is specified in a "message" modifier in an ACL, + or in a :fail: or :defer: message in a redirect router, Exim now checks the + start of the message for an SMTP error code. + +4. There is a new parameter for LDAP lookups called "referrals", which takes + one of the settings "follow" (the default) or "nofollow". + +5. Version 20070721.2 of exipick now included, offering these new options: + --reverse + After all other sorting options have bee processed, reverse order + before displaying messages (-R is synonym). + --random + Randomize order of matching messages before displaying. + --size + Instead of displaying the matching messages, display the sum + of their sizes. + --sort