X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/4e88a19f714c90a9381432c7562bd35446fd1f98..51473862ca62bf14157e0d7aa957b5a0d41748be:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 67901a28c..583fe92f1 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,4 +1,4 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.123 2006/11/14 16:40:36 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.159 2008/10/16 07:57:01 nm4 Exp $ New Features in Exim -------------------- @@ -8,6 +8,247 @@ 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. + + 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 ------------ @@ -15,232 +256,49 @@ 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. The rest of the name can contain alphanumeric characters and - underscores. This is a compatible change because the old set of variables - such as acl_m12 are a subset of the allowed names. There may now be any - number of ACL variables. For example: - - set acl_c13 = value for original ACL variable - set acl_c13b = whatever - set acl_m_foo = something - - What happens if a syntactically valid but undefined ACL variable is - referenced depends on the setting of the strict_acl_vars option. If it is - false (the default), an empty string is substituted; if it is true, an - error is generated. This affects all ACL variables, including the "old" - ones such as acl_c4. (Previously there wasn't the concept of an undefined - ACL variable.) - - The implementation has been done in such a way that spool files containing - ACL variable settings written by previous releases of Exim are compatible - and can be read by the new release. If only the original numeric names are - used, spool files written by the new release can be read by earlier - releases. + 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. Its - argument is a list of words which can be "main", "reject", or "panic". The - default is "main:reject". The list may be empty, in which case a rejection - is not logged at all. For example, this ACL fragment writes no logging - information when access is denied: - - deny - log_reject_target = - - The modifier can be used in SMTP and non-SMTP ACLs. It applies to both - permanent and temporary rejections. + 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. If you are using Dovecot to authenticate - POP/IMAP clients, it might be helpful to use the same mechanisms for SMTP - authentication. This is a server authenticator only. The only option is - server_socket, which must specify the socket which is the interface to - Dovecot authentication. The public_name option must specify an - authentication mechanism that Dovecot is configured to support. You can - have several authenticators for different mechanisms. For example: - - dovecot_plain: - driver = dovecot - public_name = PLAIN - server_name = /var/run/dovecot/auth-client - server_setid = $auth1 - - dovecot_ntlm: - driver = dovecot - public_name = NTLM - server_name = /var/run/dovecot/auth-client - server_setid = $auth1 - - If the SMTP connection is encrypted, or if $sender_host_address is equal to - $interface_address (that is, the connection is local), the "secured" option - is passed in the Dovecot authentication command. If, for a TLS connection, - a client certificate has been verified, the "valid-client-cert" option is - passed. + 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, when the facility for restricting the matching IP - values is used, the text from the TXT record that is set in $dnslist_text - may not reflect the true reason for rejection. This happens when lists are - merged and the IP address in the A record is used to distinguish them; - unfortunately there is only one TXT record. One way round this is not to - use merged lists, but that can be inefficient because it requires multiple - DNS lookups where one would do in the vast majority of cases when the host - of interest is not on any of the lists. - - A less inefficient way of solving this problem has now been implemented. 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. As a byproduct of this, there is also - a check that the IP being tested is indeed on the first list. The first - domain is the one that is put in $dnslist_domain. For example: - - reject message = rejected because $sender_ip_address is blacklisted \ - at $dnslist_domain\n$dnslist_text - dnslists = sbl.spamhaus.org,sbl-xbl.spamhaus.org=127.0.0.2 : \ - dul.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.10 - - For the first blacklist item, this starts by doing a lookup in - sbl-xbl.spamhaus.org and testing for a 127.0.0.2 return. If there is a - match, it then looks in sbl.spamhaus.org, without checking the return - value, and as long as something is found, it looks for the corresponding - TXT record. If there is no match in sbl-xbl.spamhaus.org, nothing more is - done. The second blacklist item is processed similarly. - - If you are interested in more than one merged list, the same list must be - given several times, but because the results of the DNS lookups are cached, - the DNS calls themselves are not repeated. For example: - - reject dnslists = http.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.2 : \ - socks.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.3 : \ - misc.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.4 : \ - dul.dnsbl.sorbs.net,dnsbl.sorbs.net=127.0.0.10 - - In this case there is a lookup in dnsbl.sorbs.net, and if none of the IP - values matches (or if no record is found), this is the only lookup that is - done. Only if there is a match is one of the more specific lists consulted. - - 6. All authenticators now have a server_condition option. Previously, only - plaintext had this, and this has not changed: it must be set to the - authenticator as a server. For the others, if server_condition is set, it - is expanded if authentication is successful, and treated exactly as it is - in plaintext. This can serve as a means of adding authorization to an - authenticator. + 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, thus setting message-specific variables such - as $message_size and the header variables. The $recipients variable is - available. This feature is provided to make it easier to test expansions - that make use of these variables. However, Exim must be called by an admin - user when -Mset is used. + 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. For example: - - exim -bem /tmp/testmessage - - The file is read as a message (as if receiving a locally-submitted non-SMTP - message) before any of the test expansions are done. Thus, message-specific - variables such as $message_size and $h_from: are available. However, no - Received: header is added to the message. If the -t option is set, - recipients are read from the headers in the normal way, and are shown in - the $recipients variable. Note that recipients cannot be given on the - command line, because further arguments are taken as strings to expand - (just like -be). + -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. You can revert to - the previous behavious, that is, delay the recipient independent of the - sender, by setting address_retry_include_sender=false in the smtp - transport. However, this can lead to problems with servers that regularly - issue 4xx responses to RCPT commands. + 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. These - items may now contain arithmetic operators (plus, minus, times, divide, - remainder, negate), bitwise operators (and, or, xor, not, shift), and - parentheses. All operations are carried out using signed integer - arithmetic. Operator priorities are as in C, namely: - - (highest) not, negate - times, divide, remainder - plus, minus - shift-left, shift-right - and - xor - (lowest) or - - Binary operators with the same priority are evaluated from left to right. - For example: - - ${eval:1+1} yields 2 - ${eval:1+2*3} yields 7 - ${eval:(1+2)*3} yields 9 - ${eval:2+42%5} yields 4 - ${eval:0xc&5} yields 4 - ${eval:0xc|5} yields 13 - ${eval:0xc^5} yields 9 - ${eval:0xc>>1} yields 6 - ${eval:0xc<<1} yields 24 - ${eval:~255&0x1234} yields 4608 - ${eval:-(~255&0x1234)} yields -4608 + 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 acl verbs to vary the message - that is sent when an SMTP command. For example, in a RCPT ACL you could - have: - - accept - message = OK, I'll allow you through today - - Previously, this message modifier would have had no effect whatsoever. - - IMPORTANT: The new behaviour applies to "accept" (and "discard") only if - there is no occurrence of "endpass" in the statement. If "endpass" is - present, the behaviour reverts to the old case, where "message" applies to - rejection. This is for backwards compatibility. - - It is always possible to rewrite ACL statements so that "endpass" is not - needed (and indeed it is no longer used in the default configuration, and - is somewhat not recommended nowadays because it causes confusion.) - - It is now generally true that the "message" modifier sets up a text string - that is expanded and used as a response message if the current statement - terminates the ACL. The expansion happens at the time Exim decides that the - ACL is to end, not at the time it processes "message". If the expansion - fails, or generates an empty string, the modifier is ignored. - - For ACLs that are triggered by SMTP commands, the message is returned as - part of the SMTP response. In this situation, the message may begin with an - overriding SMTP response code, optionally followed by an "extended response - code". However, the first digit of the supplied response code must be the - same as would be sent by default. A panic occurs if it is not. For the - predata ACL, note that the default success code is 354, not 2xx. - - However, notwithstanding the previous paragraph, for the QUIT ACL, unlike - the others, the message modifier cannot override the 221 response code. - - In the case of the "connect" ACL, accepting with a message modifier - overrides the value of smtp_banner. - - The ACL test specified by acl_smtp_helo happens when the client issues the - HELO or EHLO commands, after the tests specified by helo_accept_junk_hosts, - helo_allow_chars and helo(_try)_verify_hosts. An acceptance message - modifier for EHLO/HELO may not contain more than one line (it will be - truncated at the first newline and a panic logged), and it cannot affect - the EHLO options. - +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