X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/7766a4f0bde58b3456f26dc584aa869cd1340f3c..0e8a94711a90ed63933a10ac7598e8743432837c:/doc/doc-txt/NewStuff diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff index 51ac28c37..ac707ae40 100644 --- a/doc/doc-txt/NewStuff +++ b/doc/doc-txt/NewStuff @@ -1,105 +1,362 @@ -$Cambridge: exim/doc/doc-txt/NewStuff,v 1.31 2005/03/29 14:19:21 ph10 Exp $ +$Cambridge: exim/doc/doc-txt/NewStuff,v 1.129 2007/01/22 16:29:54 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 4.67 +------------ + + 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. + + 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: + + . If = or & is used, the condition is true if any one of the looked up + IP addresses matches one of the listed addresses. Consider: + + dnslists = a.b.c=127.0.0.1 + + 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. + + . 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: + + dnslists = a.b.c==127.0.0.1 + + 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 + + dnslists = a.b.c==127.0.0.1,127.0.0.2 + + for the condition to be true. + + When ! is used to negate IP address matching, it inverts the result, giving + the precise opposite of the behaviour above. Thus: + + . If != or !& is used, the condition is true if none of the looked up IP + addresses matches one of the listed addresses. Consider: + + dnslists = a.b.c!&0.0.0.1 + + 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. + + . If !== or !=& is used, the condition is true there is at least one looked + up IP address that does not match. Consider: + + dnslists = a.b.c!=&0.0.0.1 + + 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 + + dnslists = a.b.c!=&0.0.0.1,0.0.0.2 + + for the condition to be false. + + When the DNS lookup yields only a single IP address, there is no difference + between = and == and between & and =&. + + 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. Here is complete documentation for the + available features: + + GnuTLS allows the caller to specify separate lists of permitted key + exchange methods, main cipher algorithms, and MAC algorithms. These may be + used in any combination to form a specific cipher suite. This is unlike + OpenSSL, where complete cipher names can be passed to its control function. + GnuTLS also allows a list of acceptable protocols to be supplied. + + For compatibility with OpenSSL, the tls_require_ciphers option can be set + to complete cipher suite names such as RSA_ARCFOUR_SHA, but for GnuTLS this + option controls only the cipher algorithms. Exim searches each item in the + list for the name of an available algorithm. For example, if the list + contains RSA_AES_SHA, then AES is recognized, and the behaviour is exactly + the same as if just AES were given. + + There are additional options called gnutls_require_kx, gnutls_require_mac, + and gnutls_require_protocols that can be used to restrict the key exchange + methods, MAC algorithms, and protocols, respectively. These options are + ignored if OpenSSL is in use. + + All four options are available as global options, controlling how Exim + behaves as a server, and also as options of the smtp transport, controlling + how Exim behaves as a client. All the values are string expanded. After + expansion, the values must be colon-separated lists, though the separator + can be changed in the usual way. + + Each of the four lists starts out with a default set of algorithms. If the + first item in one of the "require" options does _not_ start with an + exclamation mark, all the default items are deleted. In this case, only + those that are explicitly specified can be used. If the first item in one + of the "require" items _does_ start with an exclamation mark, the defaults + are left on the list. + + Then, any item that starts with an exclamation mark causes the relevant + entry to be removed from the list, and any item that does not start with an + exclamation mark causes a new entry to be added to the list. Unrecognized + items in the list are ignored. Thus: + + tls_require_ciphers = !ARCFOUR + + allows all the defaults except ARCFOUR, whereas + + tls_require_ciphers = AES : 3DES + + allows only cipher suites that use AES or 3DES. For tls_require_ciphers + the recognized names are AES_256, AES_128, AES (both of the preceding), + 3DES, ARCFOUR_128, ARCFOUR_40, and ARCFOUR (both of the preceding). The + default list does not contain all of these; it just has AES_256, AES_128, + 3DES, and ARCFOUR_128. + + For gnutls_require_kx, the recognized names are DHE_RSA, RSA (which + includes DHE_RSA), DHE_DSS, and DHE (which includes both DHE_RSA and + DHE_DSS). The default list contains RSA, DHE_DSS, DHE_RSA. -Version 4.51 + For gnutls_require_mac, the recognized names are SHA (synonym SHA1), and + MD5. The default list contains SHA, MD5. + + For gnutls_require_protocols, the recognized names are TLS1 and SSL3. + The default list contains TLS1, SSL3. + + In a server, the order of items in these lists is unimportant. The server + will advertise the availability of all the relevant cipher suites. However, + in a client, the order in the tls_require_ciphers list specifies a + preference order for the cipher algorithms. The first one in the client's + list that is also advertised by the server is tried first. + + 4. There is a new compile-time option called ENABLE_DISABLE_FSYNC. You must + not set this option unless you really, really, really understand what you + are doing. No pre-compiled distributions of Exim should ever set this + option. When it is set, Exim compiles a runtime option called + disable_fsync. If this is set true, Exim no longer calls fsync() to force + updated files' data to be written to disc. Unexpected events such as + crashes and power outages may cause data to be lost or scrambled. Beware. + + When ENABLE_DISABLE_FSYNC is not set, a reference to disable_fsync in a + runtime configuration generates an "unknown option" error. + + +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 ------------ -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. 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. - 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. +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. - 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: +4. There is a new parameter for LDAP lookups called "referrals", which takes + one of the settings "follow" (the default) or "nofollow". - # 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 +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). - If Exim never has to generate the parameters itself, the possibility of - stalling is removed. -PH/02 A new expansion item for dynamically loading and calling a locally- - written C function is now provided, if Exim is compiled with +Version 4.62 +------------ - EXPAND_DLFUNC=yes +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: - 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.) + ${readsocket{inet:[::1]:1234}{}... - 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. + 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. - You load and call an external function like this: +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. - ${dlfunc{/some/file}{function}{arg1}{arg2}...} +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. - 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: +Version 4.61 +------------ - int dlfunction(uschar **yield, int argc, uschar *argv[]) +The documentation is up-to-date for the 4.61 release. Major new features since +the 4.60 release are: - Where "uschar" is a typedef for "unsigned char" in local_scan.h. The - function should return one of the following values: +. An option called disable_ipv6, to disable the use of IPv6 completely. - OK Success. The string that is placed in "yield" is put into - the expanded string that is being built. +. An increase in the number of ACL variables to 20 of each type. - FAIL A non-forced expansion failure occurs, with the error - message taken from "yield", if it is set. +. 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. - FAIL_FORCED A forced expansion failure occurs, with the error message - taken from "yield" if it is set. +. The default for rfc1413_query_timeout has been changed from 30s to 5s. - ERROR Same as FAIL, except that a panic log entry is written. +. It is possible to use setclassresources() on some BSD OS to control the + resources used in pipe deliveries. - 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. +. A new ACL modifier called add_header, which can be used with any verb. -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. +. More errors are detectable in retry rules. -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. +There are a number of other additions too. -Version 4.50 +Version 4.60 ------------ -The documentation is up-to-date for the 4.50 release. +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. ****