X-Git-Url: https://git.exim.org/users/heiko/exim.git/blobdiff_plain/e5a9dba621b4301bfbe2bc05576ddc5ec752b1b5..a843aaa6426eea0384891c3b7023511cc0525522:/doc/doc-txt/NewStuff?ds=inline diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 98c6fe258..e18d215aa 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,250 +1,406 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.40 2005/05/10 10:19:11 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.157 2007/08/23 11:01:49 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. - - -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 +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 4.68 ------------ -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. + 1. The body_linecount and body_zerocount C variables are now exported in the + local_scan API. + + 2. When a dnslists lookup succeeds, the key that was looked up is now placed + in $dnslist_matched. When the key is an IP address, it is not reversed in + this variable (though it is, of course, in the actual lookup). In simple + cases, for example: + + deny dnslists = spamhaus.example + + the key is also available in another variable (in this case, + $sender_host_address). In more complicated cases, however, this is not + true. For example, using a data lookup might generate a dnslists lookup + like this: + + deny dnslists = spamhaus.example/<|192.168.1.2|192.168.6.7|... + + If this condition succeeds, the value in $dnslist_matched might be + 192.168.6.7 (for example). + + 3. Authenticators now have a client_condition option. When Exim is running as + a client, it skips an authenticator whose client_condition expansion yields + "0", "no", or "false". This can be used, for example, to skip plain text + authenticators when the connection is not encrypted by a setting such as: + + client_condition = ${if !eq{$tls_cipher}{}} + + Note that the 4.67 documentation states that $tls_cipher contains the + cipher used for incoming messages. In fact, during SMTP delivery, it + contains the cipher used for the delivery. The same is true for + $tls_peerdn. + + 4. There is now a -Mvc option, which outputs a copy of the + message to the standard output, in RFC 2822 format. The option can be used + only by an admin user. + + 5. There is now a /noupdate option for the ratelimit ACL condition. It + computes the rate and checks the limit as normal, but it does not update + the saved data. This means that, in relevant ACLs, it is possible to lookup + the existence of a specified (or auto-generated) ratelimit key without + incrementing the ratelimit counter for that key. + + In order for this to be useful, another ACL entry must set the rate + for the same key somewhere (otherwise it will always be zero). + + Example: + + acl_check_connect: + # Read the rate; if it doesn't exist or is below the maximum + # we update it below + deny ratelimit = 100 / 5m / strict / noupdate + log_message = RATE: $sender_rate / $sender_rate_period \ + (max $sender_rate_limit) + + [... some other logic and tests...] + + warn ratelimit = 100 / 5m / strict / per_cmd + log_message = RATE UPDATE: $sender_rate / $sender_rate_period \ + (max $sender_rate_limit) + condition = ${if le{$sender_rate}{$sender_rate_limit}} + + accept + + 6. The variable $max_received_linelength contains the number of bytes in the + longest line that was received as part of the message, not counting the + line termination character(s). + + 7. Host lists can now include +ignore_defer and +include_defer, analagous to + +ignore_unknown and +include_unknown. These options should be used with + care, probably only in non-critical host lists such as whitelists. + + 8. There's a new option called queue_only_load_latch, which defaults true. + If set false when queue_only_load is greater than zero, Exim re-evaluates + the load for each incoming message in an SMTP session. Otherwise, once one + message is queued, the remainder are also. + + 9. There is a new ACL, specified by smtp_notquit_acl, which is run in most + cases when an SMTP session ends without sending QUIT. However, when Exim + itself is is bad trouble, such as being unable to write to its log files, + this ACL is not run, because it might try to do things (such as write to + log files) that make the situation even worse. - 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. + Like the QUIT ACL, this new ACL is provided to make it possible to gather + statistics. Whatever it returns (accept or deny) is immaterial. The "delay" + modifier is forbidden in this ACL. - 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: + When the NOTQUIT ACL is running, the variable $smtp_notquit_reason is set + to a string that indicates the reason for the termination of the SMTP + connection. The possible values are: - # 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 + acl-drop Another ACL issued a "drop" command + bad-commands Too many unknown or non-mail commands + command-timeout Timeout while reading SMTP commands + connection-lost The SMTP connection has been lost + data-timeout Timeout while reading message data + local-scan-error The local_scan() function crashed + local-scan-timeout The local_scan() function timed out + signal-exit SIGTERM or SIGINT + synchronization-error SMTP synchronization error + tls-failed TLS failed to start - If Exim never has to generate the parameters itself, the possibility of - stalling is removed. + In most cases when an SMTP connection is closed without having received + QUIT, Exim sends an SMTP response message before actually closing the + connection. With the exception of acl-drop, the default message can be + overridden by the "message" modifier in the NOTQUIT ACL. In the case of a + "drop" verb in another ACL, it is the message from the other ACL that is + used. -PH/02 A new expansion item for dynamically loading and calling a locally- - written C function is now provided, if Exim is compiled with +10. For MySQL and PostgreSQL lookups, it is now possible to specify a list of + servers with individual queries. This is done by starting the query with + "servers=x:y:z;", where each item in the list may take one of two forms: - EXPAND_DLFUNC=yes + (1) If it is just a host name, the appropriate global option (mysql_servers + or pgsql_servers) is searched for a host of the same name, and the + remaining parameters (database, user, password) are taken from there. - 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.) + (2) If it contains any slashes, it is taken as a complete parameter set. - 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. + The list of servers is used in exactly the same was as the global list. + Once a connection to a server has happened and a query has been + successfully executed, processing of the lookup ceases. - 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: + This feature is intended for use in master/slave situations where updates + are occurring, and one wants to update a master rather than a slave. If the + masters are in the list for reading, you might have: - warn !verify = sender - set acl_m0 = $acl_verify_message + mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw - 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 + In an updating lookup, you could then write + + ${lookup mysql{servers=master; UPDATE ...} + + If, on the other hand, the master is not to be used for reading lookups: + + pgsql_servers = slave1/db/name/pw:slave2/db/name/pw + + you can still update the master by + + ${lookup pgsql{servers=master/db/name/pw; UPDATE ...} + +11. The message_body_newlines option (default FALSE, for backwards + compatibility) can be used to control whether newlines are present in + $message_body and $message_body_end. If it is FALSE, they are replaced by + spaces. + + +Version 4.67 ------------ -The documentation is up-to-date for the 4.50 release. + 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. + + 2. When an item in a dnslists list is followed by = and & and a list of IP + addresses, the behaviour was not clear when the lookup returned more than + one IP address. This has been solved by the addition of == and =& for "all" + rather than the default "any" matching. + + 3. Up till now, the only control over which cipher suites GnuTLS uses has been + for the cipher algorithms. New options have been added to allow some of the + other parameters to be varied. + + 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is + set, Exim compiles a runtime option called disable_fsync. + + 5. There is a new variable called $smtp_count_at_connection_start. + + 6. There's a new control called no_pipelining. + + 7. There are two new variables called $sending_ip_address and $sending_port. + These are set whenever an SMTP connection to another host has been set up. + + 8. The expansion of the helo_data option in the smtp transport now happens + after the connection to the server has been made. + + 9. There is a new expansion operator ${rfc2047d: that decodes strings that + are encoded as per RFC 2047. + +10. There is a new log selector called "pid", which causes the current process + id to be added to every log line, in square brackets, immediately after the + time and date. + +11. Exim has been modified so that it flushes SMTP output before implementing + a delay in an ACL. It also flushes the output before performing a callout, + as this can take a substantial time. These behaviours can be disabled by + obeying control = no_delay_flush or control = no_callout_flush, + respectively, at some earlier stage of the connection. + +12. There are two new expansion conditions that iterate over a list. They are + called forany and forall. + +13. There's a new global option called dsn_from that can be used to vary the + contents of From: lines in bounces and other automatically generated + messages ("delivery status notifications" - hence the name of the option). + +14. The smtp transport has a new option called hosts_avoid_pipelining. + +15. By default, exigrep does case-insensitive matches. There is now a -I option + that makes it case-sensitive. + +16. A number of new features ("addresses", "map", "filter", and "reduce") have + been added to string expansions to make it easier to process lists of + items, typically addresses. + +17. There's a new ACL modifier called "continue". It does nothing of itself, + and processing of the ACL always continues with the next condition or + modifier. It is provided so that the side effects of expanding its argument + can be used. + +18. It is now possible to use newline and other control characters (those with + values less than 32, plus DEL) as separators in lists. + +19. The exigrep utility now has a -v option, which inverts the matching + condition. + +20. The host_find_failed option in the manualroute router can now be set to + "ignore". + + +Version 4.66 +------------ + +No new features were added to 4.66. + + +Version 4.65 +------------ + +No new features were added to 4.65. + + +Version 4.64 +------------ + + 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. + + 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. + + 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. + + 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. + + 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. + + 6. All authenticators now have a server_condition option. + + 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. + + 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. + + 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. + +10. Unary negation and the bitwise logical operators and, or, xor, not, and + shift, have been added to the eval: and eval10: expansion items. + +11. The variables $interface_address and $interface_port have been renamed + as $received_ip_address and $received_port, to make it clear that they + relate to message reception rather than delivery. (The old names remain + available for compatibility.) + +12. The "message" modifier can now be used on "accept" and "discard" acl verbs + to vary the message that is sent when an SMTP command is accepted. + + +Version 4.63 +------------ + +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 [,...] + Before displaying matching messages, sort the messages according to + each messages value for each variable. + --not + Negate the value for every test (returns inverse output from the + same criteria without --not). + + +Version 4.62 +------------ + +1. The ${readsocket expansion item now supports Internet domain sockets as well + as Unix domain sockets. If the first argument begins "inet:", it must be of + the form "inet:host:port". The port is mandatory; it may be a number or the + name of a TCP port in /etc/services. The host may be a name, or it may be an + IP address. An ip address may optionally be enclosed in square brackets. + This is best for IPv6 addresses. For example: + + ${readsocket{inet:[::1]:1234}{}... + + Only a single host name may be given, but if looking it up yield more than + one IP address, they are each tried in turn until a connection is made. Once + a connection has been made, the behaviour is as for ${readsocket with a Unix + domain socket. + +2. If a redirect router sets up file or pipe deliveries for more than one + incoming address, and the relevant transport has batch_max set greater than + one, a batch delivery now occurs. + +3. The appendfile transport has a new option called maildirfolder_create_regex. + Its value is a regular expression. For a maildir delivery, this is matched + against the maildir directory; if it matches, Exim ensures that a + maildirfolder file is created alongside the new, cur, and tmp directories. + + +Version 4.61 +------------ + +The documentation is up-to-date for the 4.61 release. Major new features since +the 4.60 release are: + +. An option called disable_ipv6, to disable the use of IPv6 completely. + +. An increase in the number of ACL variables to 20 of each type. + +. A change to use $auth1, $auth2, and $auth3 in authenticators instead of $1, + $2, $3, (though those are still set) because the numeric variables get used + for other things in complicated expansions. + +. The default for rfc1413_query_timeout has been changed from 30s to 5s. + +. It is possible to use setclassresources() on some BSD OS to control the + resources used in pipe deliveries. + +. A new ACL modifier called add_header, which can be used with any verb. + +. More errors are detectable in retry rules. + +There are a number of other additions too. + + +Version 4.60 +------------ + +The documentation is up-to-date for the 4.60 release. Major new features since +the 4.50 release are: + +. Support for SQLite. + +. Support for IGNOREQUOTA in LMTP. + +. Extensions to the "submission mode" features. + +. Support for Client SMTP Authorization (CSA). + +. Support for ratelimiting hosts and users. + +. New expansion items to help with the BATV "prvs" scheme. + +. A "match_ip" condition, that matches an IP address against a list. + +There are many more minor changes. ****