X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/431b736177e2cdfd0b4da4c8545d8b732286abe1..5ca6d115da010e279c2f928990b3c8d220378f24:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 960f93ce8..583fe92f1 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,4 +1,4 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.127 2007/01/17 11:17:58 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.159 2008/10/16 07:57:01 nm4 Exp $ New Features in Exim -------------------- @@ -8,103 +8,234 @@ 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 4.70 +------------ + + 1. Preliminary SPF Best Guess support. Documentation for this is in + experimental-spec.txt. + + +Version 4.68 +------------ + + 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 acl_smtp_notquit, 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. + + 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. + + 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: + + 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 + + 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. + +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: + + (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. + + (2) If it contains any slashes, it is taken as a complete parameter set. + + 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. + + 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: + + mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw + + 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 ------------ 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. - - 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. - - 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, - - C=EHLO,QUIT - - 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. + MAIL command. 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 - - dnslists = a.b.c=127.0.0.1 - - 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? - - 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. - - 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: + 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. - . If = or & is used, the condition is true if any one of the looked up - IP addresses matches one of the listed addresses. Consider: + 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. - dnslists = a.b.c=127.0.0.1 + 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. When it is + set, Exim compiles a runtime option called disable_fsync. - 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. + 5. There is a new variable called $smtp_count_at_connection_start. - . 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: + 6. There's a new control called no_pipelining. - dnslists = a.b.c==127.0.0.1 + 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. - 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 + 8. The expansion of the helo_data option in the smtp transport now happens + after the connection to the server has been made. - dnslists = a.b.c==127.0.0.1,127.0.0.2 + 9. There is a new expansion operator ${rfc2047d: that decodes strings that + are encoded as per RFC 2047. - for the condition to be true. +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. - When ! is used to negate IP address matching, it inverts the result, giving - the precise opposite of the behaviour above. Thus: +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. - . If != or !& is used, the condition is true if none of the looked up IP - addresses matches one of the listed addresses. Consider: +12. There are two new expansion conditions that iterate over a list. They are + called forany and forall. - dnslists = a.b.c!&0.0.0.1 +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). - 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. +14. The smtp transport has a new option called hosts_avoid_pipelining. - . If !== or !=& is used, the condition is true there is at least one looked - up IP address that does not match. Consider: +15. By default, exigrep does case-insensitive matches. There is now a -I option + that makes it case-sensitive. - dnslists = a.b.c!=&0.0.0.1 +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. - 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 +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. - dnslists = a.b.c!=&0.0.0.1,0.0.0.2 +18. It is now possible to use newline and other control characters (those with + values less than 32, plus DEL) as separators in lists. - for the condition to be false. +19. The exigrep utility now has a -v option, which inverts the matching + condition. - When the DNS lookup yields only a single IP address, there is no difference - between = and == and between & and =&. +20. The host_find_failed option in the manualroute router can now be set to + "ignore". Version 4.66