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| -rw-r--r-- | doc/doc-txt/NewStuff | 217 |
1 files changed, 17 insertions, 200 deletions
diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 9d0e93993..e61421830 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,4 +1,4 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.124 2006/12/05 11:35:28 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.125 2006/12/20 09:44:37 ph10 Exp $ New Features in Exim -------------------- @@ -15,232 +15,49 @@ 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 <some conditions> - 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 is accepted. For example, in a RCPT ACL - you could have: - - accept <some conditions> - 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 |