-$Cambridge: exim/doc/doc-txt/NewStuff,v 1.145 2007/03/13 15:32:47 ph10 Exp $
-
New Features in Exim
--------------------
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
+Version 4.78
------------
- 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.
+ 1. New authenticator driver, "gsasl". Server-only (at present).
+ This is a SASL interface, licensed under GPL, which can be found at
+ http://www.gnu.org/software/gsasl/.
+ This system does not provide sources of data for authentication, so
+ careful use needs to be made of the conditions in Exim. Note that
+ this can not yet be used as a drop-in replacement for Cyrus SASL, as
+ Exim is currently unable to construct strings with embedded NULs for
+ use as keys in lookups against sasldb2.
- 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
+Version 4.77
+------------
- 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?
+ 1. New options for the ratelimit ACL condition: /count= and /unique=.
+ The /noupdate option has been replaced by a /readonly option.
- 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.
+ 2. The SMTP transport's protocol option may now be set to "smtps", to
+ use SSL-on-connect outbound.
- 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:
+ 3. New variable $av_failed, set true if the AV scanner deferred; ie, when
+ there is a problem talking to the AV scanner, or the AV scanner running.
- . If = or & is used, the condition is true if any one of the looked up
- IP addresses matches one of the listed addresses. Consider:
+ 4. New expansion conditions, "inlist" and "inlisti", which take simple lists
+ and check if the search item is a member of the list. This does not
+ support named lists, but does subject the list part to string expansion.
- dnslists = a.b.c=127.0.0.1
+ 5. Unless the new EXPAND_LISTMATCH_RHS build option is set when Exim was
+ built, Exim no longer performs string expansion on the second string of
+ the match_* expansion conditions: "match_address", "match_domain",
+ "match_ip" & "match_local_part". Named lists can still be used.
- 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:
+Version 4.76
+------------
- dnslists = a.b.c==127.0.0.1
+ 1. The global option "dns_use_edns0" may be set to coerce EDNS0 usage on
+ or off in the resolver library.
- 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
+Version 4.75
+------------
- for the condition to be true.
+ 1. In addition to the existing LDAP and LDAP/SSL ("ldaps") support, there
+ is now LDAP/TLS support, given sufficiently modern OpenLDAP client
+ libraries. The following global options have been added in support of
+ this: ldap_ca_cert_dir, ldap_ca_cert_file, ldap_cert_file, ldap_cert_key,
+ ldap_cipher_suite, ldap_require_cert, ldap_start_tls.
- When ! is used to negate IP address matching, it inverts the result, giving
- the precise opposite of the behaviour above. Thus:
+ 2. The pipe transport now takes a boolean option, "freeze_signal", default
+ false. When true, if the external delivery command exits on a signal then
+ Exim will freeze the message in the queue, instead of generating a bounce.
- . If != or !& is used, the condition is true if none of the looked up IP
- addresses matches one of the listed addresses. Consider:
+ 3. Log filenames may now use %M as an escape, instead of %D (still available).
+ The %M pattern expands to yyyymm, providing month-level resolution.
- dnslists = a.b.c!&0.0.0.1
+ 4. The $message_linecount variable is now updated for the maildir_tag option,
+ in the same way as $message_size, to reflect the real number of lines,
+ including any header additions or removals from transport.
- 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.
+ 5. When contacting a pool of SpamAssassin servers configured in spamd_address,
+ Exim now selects entries randomly, to better scale in a cluster setup.
- . 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
+Version 4.74
+------------
- 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
+ 1. SECURITY FIX: privilege escalation flaw fixed. On Linux (and only Linux)
+ the flaw permitted the Exim run-time user to cause root to append to
+ arbitrary files of the attacker's choosing, with the content based
+ on content supplied by the attacker.
- dnslists = a.b.c!=&0.0.0.1,0.0.0.2
+ 2. Exim now supports loading some lookup types at run-time, using your
+ platform's dlopen() functionality. This has limited platform support
+ and the intention is not to support every variant, it's limited to
+ dlopen(). This permits the main Exim binary to not be linked against
+ all the libraries needed for all the lookup types.
- 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 =&.
+Version 4.73
+------------
- 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.
-
- 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.
-
- 5. There is a new variable called $smtp_count_at_connection_start. The name
- is deliberately long, in order to emphasize what the contents are. This
- variable is set greater than zero only in processes spawned by the Exim
- daemon for handling incoming SMTP connections. When the daemon accepts a
- new connection, it increments this variable. A copy of the variable is
- passed to the child process that handles the connection, but its value is
- fixed, and never changes. It is only an approximation of how many incoming
- connections there actually are, because many other connections may come and
- go while a single connection is being processed. When a child process
- terminates, the daemon decrements the variable.
-
- 6. There's a new control called no_pipelining, which does what its name
- suggests. It turns off the advertising of the PIPELINING extension to SMTP.
- To be useful, this control must be obeyed before Exim sends its response to
- an EHLO command. Therefore, it should normally appear in an ACL controlled
- by acl_smtp_connect or acl_smtp_helo.
+ NOTE: this version is not guaranteed backwards-compatible, please read the
+ items below carefully
+
+ 1. A new main configuration option, "openssl_options", is available if Exim
+ is built with SSL support provided by OpenSSL. The option allows
+ administrators to specify OpenSSL options to be used on connections;
+ typically this is to set bug compatibility features which the OpenSSL
+ developers have not enabled by default. There may be security
+ consequences for certain options, so these should not be changed
+ frivolously.
+
+ 2. A new pipe transport option, "permit_coredumps", may help with problem
+ diagnosis in some scenarios. Note that Exim is typically installed as
+ a setuid binary, which on most OSes will inhibit coredumps by default,
+ so that safety mechanism would have to be overridden for this option to
+ be able to take effect.
+
+ 3. ClamAV 0.95 is now required for ClamAV support in Exim, unless
+ Local/Makefile sets: WITH_OLD_CLAMAV_STREAM=yes
+ Note that this switches Exim to use a new API ("INSTREAM") and a future
+ release of ClamAV will remove support for the old API ("STREAM").
+
+ The av_scanner option, when set to "clamd", now takes an optional third
+ part, "local", which causes Exim to pass a filename to ClamAV instead of
+ the file content. This is the same behaviour as when clamd is pointed at
+ a Unix-domain socket. For example:
+
+ av_scanner = clamd:192.0.2.3 1234:local
+
+ ClamAV's ExtendedDetectionInfo response format is now handled.
+
+ 4. There is now a -bmalware option, restricted to admin users. This option
+ takes one parameter, a filename, and scans that file with Exim's
+ malware-scanning framework. This is intended purely as a debugging aid
+ to ensure that Exim's scanning is working, not to replace other tools.
+ Note that the ACL framework is not invoked, so if av_scanner references
+ ACL variables without a fallback then this will fail.
+
+ 5. There is a new expansion operator, "reverse_ip", which will reverse IP
+ addresses; IPv4 into dotted quad, IPv6 into dotted nibble. Examples:
+
+ ${reverse_ip:192.0.2.4}
+ -> 4.2.0.192
+ ${reverse_ip:2001:0db8:c42:9:1:abcd:192.0.2.3}
+ -> 3.0.2.0.0.0.0.c.d.c.b.a.1.0.0.0.9.0.0.0.2.4.c.0.8.b.d.0.1.0.0.2
+
+ 6. There is a new ACL control called "debug", to enable debug logging.
+ This allows selective logging of certain incoming transactions within
+ production environments, with some care. It takes two options, "tag"
+ and "opts"; "tag" is included in the filename of the log and "opts"
+ is used as per the -d<options> command-line option. Examples, which
+ don't all make sense in all contexts:
+
+ control = debug
+ control = debug/tag=.$sender_host_address
+ control = debug/opts=+expand+acl
+ control = debug/tag=.$message_exim_id/opts=+expand
+
+ 7. It has always been implicit in the design and the documentation that
+ "the Exim user" is not root. src/EDITME said that using root was
+ "very strongly discouraged". This is not enough to keep people from
+ shooting themselves in the foot in days when many don't configure Exim
+ themselves but via package build managers. The security consequences of
+ running various bits of network code are severe if there should be bugs in
+ them. As such, the Exim user may no longer be root. If configured
+ statically, Exim will refuse to build. If configured as ref:user then Exim
+ will exit shortly after start-up. If you must shoot yourself in the foot,
+ then henceforth you will have to maintain your own local patches to strip
+ the safeties off.
+
+ 8. There is a new expansion operator, bool_lax{}. Where bool{} uses the ACL
+ condition logic to determine truth/failure and will fail to expand many
+ strings, bool_lax{} uses the router condition logic, where most strings
+ do evaluate true.
+ Note: bool{00} is false, bool_lax{00} is true.
+
+ 9. Routers now support multiple "condition" tests,
+
+10. There is now a runtime configuration option "tcp_wrappers_daemon_name".
+ Setting this allows an admin to define which entry in the tcpwrappers
+ config file will be used to control access to the daemon. This option
+ is only available when Exim is built with USE_TCP_WRAPPERS. The
+ default value is set at build time using the TCP_WRAPPERS_DAEMON_NAME
+ build option.
+
+11. [POSSIBLE CONFIG BREAKAGE] The default value for system_filter_user is now
+ the Exim run-time user, instead of root.
+
+12. [POSSIBLE CONFIG BREAKAGE] ALT_CONFIG_ROOT_ONLY is no longer optional and
+ is forced on. This is mitigated by the new build option
+ TRUSTED_CONFIG_LIST which defines a list of configuration files which
+ are trusted; one per line. If a config file is owned by root and matches
+ a pathname in the list, then it may be invoked by the Exim build-time
+ user without Exim relinquishing root privileges.
+
+13. [POSSIBLE CONFIG BREAKAGE] The Exim user is no longer automatically
+ trusted to supply -D<Macro[=Value]> overrides on the command-line. Going
+ forward, we recommend using TRUSTED_CONFIG_LIST with shim configs that
+ include the main config. As a transition mechanism, we are temporarily
+ providing a work-around: the new build option WHITELIST_D_MACROS provides
+ a colon-separated list of macro names which may be overridden by the Exim
+ run-time user. The values of these macros are constrained to the regex
+ ^[A-Za-z0-9_/.-]*$ (which explicitly does allow for empty values).
+
+
+Version 4.72
+------------
- 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,
- and they contain the IP address and port of the local interface that is
- being used. They are of interest only on hosts that have more than on IP
- address that want to take on different personalities depending on which one
- is being used.
+ 1. TWO SECURITY FIXES: one relating to mail-spools which are globally
+ writable, the other to locking of MBX folders (not mbox).
- 8. The expansion of the helo_data option in the smtp transport now happens
- after the connection to the server has been made. This means that it can
- use the value of $sending_ip_address (see 7 above) to vary the text of the
- message. For example, if you want the string that is used for helo_data to
- be obtained by a DNS lookup of the interface address, you could use this:
+ 2. MySQL stored procedures are now supported.
- helo_data = ${lookup dnsdb{ptr=$sending_ip_address}{$value}\
- {$primary_hostname}}
+ 3. The dkim_domain transport option is now a list, not a single string, and
+ messages will be signed for each element in the list (discarding
+ duplicates).
- The use of helo_data applies both to sending messages and when doing
- callouts.
+ 4. The 4.70 release unexpectedly changed the behaviour of dnsdb TXT lookups
+ in the presence of multiple character strings within the RR. Prior to 4.70,
+ only the first string would be returned. The dnsdb lookup now, by default,
+ preserves the pre-4.70 semantics, but also now takes an extended output
+ separator specification. The separator can be followed by a semicolon, to
+ concatenate the individual text strings together with no join character,
+ or by a comma and a second separator character, in which case the text
+ strings within a TXT record are joined on that second character.
+ Administrators are reminded that DNS provides no ordering guarantees
+ between multiple records in an RRset. For example:
- 9. There is a new expansion operator ${rfc2047d: that decodes strings that
- are encoded as per RFC 2047. Binary zero bytes are replaced by question
- marks. Characters are converted into the character set defined by
- headers_charset. Overlong RFC 2047 "words" are not recognized unless
- check_rfc2047_length is set false.
+ foo.example. IN TXT "a" "b" "c"
+ foo.example. IN TXT "d" "e" "f"
-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.
+ ${lookup dnsdb{>/ txt=foo.example}} -> "a/d"
+ ${lookup dnsdb{>/; txt=foo.example}} -> "def/abc"
+ ${lookup dnsdb{>/,+ txt=foo.example}} -> "a+b+c/d+e+f"
-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. The effect of the
- new default behaviour is to disable the PIPELINING optimization in these
- situations, in order to avoid unexpected timeouts in clients.
-12. There are two new expansion conditions that iterate over a list. They are
- called forany and forall, and they are used like this:
+Version 4.70 / 4.71
+-------------------
- ${if forany{<a list>}{<a condition>}{<yes-string>}{<no-string>}}
- ${if forall{<a list>}{<a condition>}{<yes-string>}{<no-string>}}
+ 1. Native DKIM support without an external library.
+ (Note that if no action to prevent it is taken, a straight upgrade will
+ result in DKIM verification of all signed incoming emails. See spec
+ for details on conditionally disabling)
- The first argument is expanded, and the result is treated as a list. By
- default, the list separator is a colon, but it can be changed by the normal
- method. The second argument is interpreted as a condition that is to be
- applied to each item in the list in turn. During the interpretation of the
- condition, the current list item is placed in a variable called $item.
+ 2. Experimental DCC support via dccifd (contributed by Wolfgang Breyha).
- - For forany, interpretation stops if the condition is true for any item,
- and the yes-string is then expanded. If the condition is false for all
- items in the list, the no-string is expanded.
+ 3. There is now a bool{} expansion condition which maps certain strings to
+ true/false condition values (most likely of use in conjunction with the
+ and{} expansion operator).
- - For forall, interpration stops if the condition is false for any item,
- and the no-string is then expanded. If the condition is true for all
- items in the list, the yes-string is expanded.
+ 4. The $spam_score, $spam_bar and $spam_report variables are now available
+ at delivery time.
- Note that negation of forany means that the condition must be false for all
- items for the overall condition to succeed, and negation of forall means
- that the condition must be false for at least one item.
+ 5. exim -bP now supports "macros", "macro_list" or "macro MACRO_NAME" as
+ options, provided that Exim is invoked by an admin_user.
- In this example, the list separator is changed to a comma:
+ 6. There is a new option gnutls_compat_mode, when linked against GnuTLS,
+ which increases compatibility with older clients at the cost of decreased
+ security. Don't set this unless you need to support such clients.
- ${if forany{<, $recipients}{match{$item}{^user3@}}{yes}{no}}
+ 7. There is a new expansion operator, ${randint:...} which will produce a
+ "random" number less than the supplied integer. This randomness is
+ not guaranteed to be cryptographically strong, but depending upon how
+ Exim was built may be better than the most naive schemes.
- Outside a forany/forall condition, the value of $item is an empty string.
- Its value is saved and restored while forany/forall is being processed, to
- enable these expansion items to be nested.
+ 8. Exim now explicitly ensures that SHA256 is available when linked against
+ OpenSSL.
-13. There's a new global option called dsn_from that can be used to vary the
- contents of From: lines in bounces and other automatically generated
- messages ("delivery status notifications" - hence the name of the option).
- The default setting is:
+ 9. The transport_filter_timeout option now applies to SMTP transports too.
- dsn_from = Mail Delivery System <Mailer-Daemon@$qualify_domain>
- The value is expanded every time it is needed. If the expansion fails, a
- panic is logged, and the default setting is used.
+Version 4.69
+------------
-14. The smtp transport has a new option called hosts_avoid_pipelining. It can
- be used to suppress the use of PIPELINING to certain hosts, while still
- supporting the other SMTP extensions (cf hosts_avoid_tls).
+ 1. Preliminary DKIM support in Experimental.
-15. By default, exigrep does case-insensitive matches. There is now a -I option
- that makes it case-sensitive. This may give a performance improvement when
- searching large log files. Without -I, the Perl pattern matches use the /i
- option; with -I they don't. In both cases it is possible to change the case
- sensitivity within the pattern using (?i) or (?-i).
-16. A number of new features have been added to string expansions to make it
- easier to process lists of items, typically addresses. These are as
- follows:
+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 <message-id> 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.
- * ${addresses:<string>}
+ 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.
- The string (after expansion) is interpreted as a list of addresses in RFC
- 2822 format, such as can be found in a To: or Cc: header line. The
- operative address (local-part@domain) is extracted from each item, and the
- result of the expansion is a colon-separated list, with appropriate
- doubling of colons should any happen to be present in the email addresses.
- Syntactically invalid RFC2822 address items are omitted from the output.
+ 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.
- It is possible to specify a character other than colon for the output
- separator by starting the string with > followed by the new separator
- character. For example:
+ 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:
- ${addresses:>& The Boss <ceo@up.stairs>, sec@base.ment (dogsbody)}
+ 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
- expands to "ceo@up.stairs&sec@base.ment". Compare ${address (singular),
- which extracts the working address from a single RFC2822 address.
+ 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.
- * ${map{<string1>}{<string2>}}
+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:
- After expansion, <string1> is interpreted as a list, colon-separated by
- default, but the separator can be changed in the usual way. For each item
- in this list, its value is place in $item, and then <string2> is expanded
- and added to the output as an item in a new list. The separator used for
- the output list is the same as the one used for the input, but is not
- included in the output. For example:
+ (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.
- ${map{a:b:c}{[$item]}} ${map{<- x-y-z}{($item)}}
+ (2) If it contains any slashes, it is taken as a complete parameter set.
- expands to "[a]:[b]:[c] (x)-(y)-(z)". At the end of the expansion, the
- value of $item is restored to what it was before.
+ 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.
- * ${filter{<string1>}{<condition>}}
+ 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:
- After expansion, <string1> is interpreted as a list, colon-separated by
- default, but the separator can be changed in the usual way. For each item
- in this list, its value is place in $item, and then the condition is
- evaluated. If the condition is true, $item is added to the output as an
- item in a new list; if the condition is false, the item is discarded. The
- separator used for the output list is the same as the one used for the
- input, but is not included in the output. For example:
+ mysql_servers = slave1/db/name/pw:slave2/db/name/pw:master/db/name/pw
- ${filter{a:b:c}{!eq{$item}{b}}
+ In an updating lookup, you could then write
- yields "a:c". At the end of the expansion, the value of $item is restored
- to what it was before.
+ ${lookup mysql{servers=master; UPDATE ...}
- * ${reduce{<string1>}{<string2>}{<string3>}}
+ If, on the other hand, the master is not to be used for reading lookups:
- The ${reduce expansion operation reduces a list to a single, scalar string.
- After expansion, <string1> is interpreted as a list, colon-separated by
- default, but the separator can be changed in the usual way. Then <string2>
- is expanded and assigned to the $value variable. After this, each item in
- the <string1> list is assigned to $item in turn, and <string3> is expanded
- for each of them. The result of that expansion is assigned to $value before
- the next iteration. When the end of the list is reached, the final value of
- $value is added to the expansion string. The ${reduce expansion item can be
- used in a number of ways. For example, to add up a list of numbers:
+ pgsql_servers = slave1/db/name/pw:slave2/db/name/pw
- ${reduce {<, 1,2,3}{0}{${eval:$value+$item}}}
+ you can still update the master by
- The result of that expansion would be "6". The maximum of a list of numbers
- can be found:
+ ${lookup pgsql{servers=master/db/name/pw; UPDATE ...}
- ${reduce {3:0:9:4:6}{0}{${if >{$item}{$value}{$item}{$value}}}}
+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.
- At the end of a ${reduce expansion, the values of $item and $value is
- restored to what they were before.
+
+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. Typically this would be for updating a database. It is really
- just a syntactic tidiness, because the following two lines have the same
- effect:
-
- continue = <some expansion>
- condition = ${if eq{0}{<some expansion>}{true}{true}}
+ 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. Such separators must
- be provided literally at the time the list is processed, but the string
- expansion that happens first means that you can write them using normal
- escape sequences. For example, if a new-line separated list of domains is
- generated by a lookup, you can now process it directly by a line such as
- this:
-
- domains = <\n ${lookup mysql{.....}}
-
- This avoids having to change the list separator in such data. Unlike
- printing character separators, which can be included in list items by
- doubling, it is not possible to include a control character as data when it
- is set as the separator. Two such characters in succession are interpreted
- as enclosing an empty list item.
+ 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". This causes it to completely ignore a host whose IP address
- cannot be found. If all the hosts in the list are ignored, the behaviour is
- controlled by the new host_all_ignored option, which takes the same values
- as host_find_failed, except that it cannot be set to "ignore". Its default
- is "defer".
+ "ignore".
Version 4.66
projects / exim.git / blobdiff