Docs clarification

[users/heiko/exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index df63ad6a0bc5f05a208e198176b24ab9820a8204..ed67f8109f9979f86426275f2cf38ca9bd21a62b 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -45,7 +45,7 @@
 . Update the Copyright year (only) when changing content.
 . /////////////////////////////////////////////////////////////////////////////
 
 . Update the Copyright year (only) when changing content.
 . /////////////////////////////////////////////////////////////////////////////
 

-.set previousversion "4.83"
+.set previousversion "4.84"

 .include ./local_params
 
 .set ACL "access control lists (ACLs)"
 .include ./local_params
 
 .set ACL "access control lists (ACLs)"


@@ -5567,7 +5567,7 @@ of an incoming SMTP connection.
 If you have hosts for which you trust RFC1413 and need this
 information, you can change this.
 
 If you have hosts for which you trust RFC1413 and need this
 information, you can change this.
 

-This line enables an efficiency SMTP option.  It is negociated by clients
+This line enables an efficiency SMTP option.  It is negotiated by clients

 and not expected to cause problems but can be disabled if needed.
 .code
 prdr_enable = true
 and not expected to cause problems but can be disabled if needed.
 .code
 prdr_enable = true


@@ -8939,8 +8939,10 @@ a right angle-bracket followed immediately by the new separator.
 Recognised RDN type labels include "CN", "O", "OU" and "DC".
 
 The field selectors marked as "time" above
 Recognised RDN type labels include "CN", "O", "OU" and "DC".
 
 The field selectors marked as "time" above

-may output a number of seconds since epoch
-if the modifier "int" is used.
+take an optional modifier of "int"
+for which the result is the number of seconds since epoch.
+Otherwise the result is a human-readable string
+in the timezone selected by the main "timezone" option.

 
 The field selectors marked as "list" above return a list,
 newline-separated by default,
 
 The field selectors marked as "list" above return a list,
 newline-separated by default,


@@ -9507,7 +9509,7 @@ locks out the use of this expansion item in filter files.
 .cindex "expansion" "inserting from a socket"
 .cindex "socket, use of in expansion"
 .cindex "&%readsocket%& expansion item"
 .cindex "expansion" "inserting from a socket"
 .cindex "socket, use of in expansion"
 .cindex "&%readsocket%& expansion item"

-This item inserts data from a Unix domain or Internet socket into the expanded
+This item inserts data from a Unix domain or TCP socket into the expanded

 string. The minimal way of using it uses just two arguments, as in these
 examples:
 .code
 string. The minimal way of using it uses just two arguments, as in these
 examples:
 .code


@@ -11930,10 +11932,7 @@ on which interface and/or port is being used for the incoming connection. The
 values of &$received_ip_address$& and &$received_port$& are saved with any
 messages that are received, thus making these variables available at delivery
 time.
 values of &$received_ip_address$& and &$received_port$& are saved with any
 messages that are received, thus making these variables available at delivery
 time.

-
-&*Note:*& There are no equivalent variables for outgoing connections, because
-the values are unknown (unless they are explicitly set by options of the
-&(smtp)& transport).
+For outbound connections see &$sending_ip_address$&.

 
 .vitem &$received_port$&
 .vindex "&$received_port$&"
 
 .vitem &$received_port$&
 .vindex "&$received_port$&"


@@ -12152,8 +12151,9 @@ the &%-bs%& or &%-bS%& options.
 
 .vitem &$sender_host_address$&
 .vindex "&$sender_host_address$&"
 
 .vitem &$sender_host_address$&
 .vindex "&$sender_host_address$&"

-When a message is received from a remote host, this variable contains that
-host's IP address. For locally submitted messages, it is empty.
+When a message is received from a remote host using SMTP,
+this variable contains that
+host's IP address. For locally non-SMTP submitted messages, it is empty.

 
 .vitem &$sender_host_authenticated$&
 .vindex "&$sender_host_authenticated$&"
 
 .vitem &$sender_host_authenticated$&
 .vindex "&$sender_host_authenticated$&"


@@ -12592,6 +12592,13 @@ This variable contains the result of an expansion lookup, extraction operation,
 or external command, as described above. It is also used during a
 &*reduce*& expansion.
 
 or external command, as described above. It is also used during a
 &*reduce*& expansion.
 

+.vitem &$verify_mode$&
+.vindex "&$verify_mode$&"
+While a router or transport is being run in verify mode
+or for cutthrough delivery,
+contains "S" for sender-verification or "R" for recipient-verification.
+Otherwise, empty.
+

 .vitem &$version_number$&
 .vindex "&$version_number$&"
 The version number of Exim.
 .vitem &$version_number$&
 .vindex "&$version_number$&"
 The version number of Exim.


@@ -15054,16 +15061,21 @@ yourself in the foot in various unpleasant ways.  This option should not be
 adjusted lightly.  An unrecognised item will be detected at startup, by
 invoking Exim with the &%-bV%& flag.
 
 adjusted lightly.  An unrecognised item will be detected at startup, by
 invoking Exim with the &%-bV%& flag.
 

+The option affects Exim operating both as a server and as a client.
+

 Historical note: prior to release 4.80, Exim defaulted this value to
 "+dont_insert_empty_fragments", which may still be needed for compatibility
 with some clients, but which lowers security by increasing exposure to
 some now infamous attacks.
 
 Historical note: prior to release 4.80, Exim defaulted this value to
 "+dont_insert_empty_fragments", which may still be needed for compatibility
 with some clients, but which lowers security by increasing exposure to
 some now infamous attacks.
 

-An example:
+Examples:

 .code
 # Make both old MS and old Eudora happy:
 openssl_options = -all +microsoft_big_sslv3_buffer \
                        +dont_insert_empty_fragments
 .code
 # Make both old MS and old Eudora happy:
 openssl_options = -all +microsoft_big_sslv3_buffer \
                        +dont_insert_empty_fragments

+
+# Disable older protocol versions:
+openssl_options = +no_sslv2 +no_sslv3

 .endd
 
 Possible options may include:
 .endd
 
 Possible options may include:


@@ -16484,16 +16496,23 @@ See &%tls_verify_hosts%& below.
 The value of this option is expanded, and must then be the absolute path to
 a file containing permitted certificates for clients that
 match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&. Alternatively, if you
 The value of this option is expanded, and must then be the absolute path to
 a file containing permitted certificates for clients that
 match &%tls_verify_hosts%& or &%tls_try_verify_hosts%&. Alternatively, if you

-are using OpenSSL, you can set &%tls_verify_certificates%& to the name of a
-directory containing certificate files. This does not work with GnuTLS; the
-option must be set to the name of a single file if you are using GnuTLS.
+are using either GnuTLS version 3.3.6 (or later) or OpenSSL,
+you can set &%tls_verify_certificates%& to the name of a
+directory containing certificate files.
+For earlier versions of GnuTLS
+the option must be set to the name of a single file.
+
+With OpenSSL the certificates specified
+explicitly
+either by file or directory
+are added to those given by the system default location.

 
 These certificates should be for the certificate authorities trusted, rather
 than the public cert of individual clients.  With both OpenSSL and GnuTLS, if
 the value is a file then the certificates are sent by Exim as a server to
 connecting clients, defining the list of accepted certificate authorities.
 Thus the values defined should be considered public data.  To avoid this,
 
 These certificates should be for the certificate authorities trusted, rather
 than the public cert of individual clients.  With both OpenSSL and GnuTLS, if
 the value is a file then the certificates are sent by Exim as a server to
 connecting clients, defining the list of accepted certificate authorities.
 Thus the values defined should be considered public data.  To avoid this,

-use OpenSSL with a directory.
+use the explicit directory version.

 
 See &<<SECTtlssni>>& for discussion of when this option might be re-expanded.
 
 
 See &<<SECTtlssni>>& for discussion of when this option might be re-expanded.
 


@@ -16866,7 +16885,7 @@ be specified using &%condition%&.
 Historical note: We have &%condition%& on ACLs and on Routers.  Routers
 are far older, and use one set of semantics.  ACLs are newer and when
 they were created, the ACL &%condition%& process was given far stricter
 Historical note: We have &%condition%& on ACLs and on Routers.  Routers
 are far older, and use one set of semantics.  ACLs are newer and when
 they were created, the ACL &%condition%& process was given far stricter

-parse semantics.  The &%bool{}&% expansion condition uses the same rules as
+parse semantics.  The &%bool{}%& expansion condition uses the same rules as

 ACLs.  The &%bool_lax{}%& expansion condition uses the same rules as
 Routers.  More pointedly, the &%bool_lax{}%& was written to match the existing
 Router rules processing behavior.
 ACLs.  The &%bool_lax{}%& expansion condition uses the same rules as
 Routers.  More pointedly, the &%bool_lax{}%& was written to match the existing
 Router rules processing behavior.


@@ -17777,6 +17796,7 @@ delivering in cutthrough mode
 or testing recipient verification using &%-bv%&.
 See section &<<SECTrouprecon>>& for a list of the order in which preconditions
 are evaluated.
 or testing recipient verification using &%-bv%&.
 See section &<<SECTrouprecon>>& for a list of the order in which preconditions
 are evaluated.

+See also the &$verify_mode$& variable.

 
 
 .option verify_sender routers&!? boolean true
 
 
 .option verify_sender routers&!? boolean true


@@ -17784,6 +17804,7 @@ If this option is false, the router is skipped when verifying sender addresses
 or testing sender verification using &%-bvs%&.
 See section &<<SECTrouprecon>>& for a list of the order in which preconditions
 are evaluated.
 or testing sender verification using &%-bvs%&.
 See section &<<SECTrouprecon>>& for a list of the order in which preconditions
 are evaluated.

+See also the &$verify_mode$& variable.

 .ecindex IIDgenoprou1
 .ecindex IIDgenoprou2
 
 .ecindex IIDgenoprou1
 .ecindex IIDgenoprou2
 


@@ -23412,7 +23433,7 @@ unknown state), opens a new one to the same host, and then tries the delivery
 in clear.
 
 
 in clear.
 
 

-.option tls_try_verify_hosts smtp "host list&!! unset
+.option tls_try_verify_hosts smtp "host list&!!" unset

 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which, on encrypted connections,
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which, on encrypted connections,


@@ -23420,7 +23441,7 @@ certificate verification will be tried but need not succeed.
 The &%tls_verify_certificates%& option must also be set.
 Note that unless the host is in this list
 TLS connections will be denied to hosts using self-signed certificates
 The &%tls_verify_certificates%& option must also be set.
 Note that unless the host is in this list
 TLS connections will be denied to hosts using self-signed certificates

-when &%tls_verify_certificates%& is set.
+when &%tls_verify_certificates%& is matched.

 The &$tls_out_certificate_verified$& variable is set when
 certificate verification succeeds.
 
 The &$tls_out_certificate_verified$& variable is set when
 certificate verification succeeds.
 


@@ -23432,10 +23453,20 @@ certificate verification succeeds.
 .vindex "&$host_address$&"
 The value of this option must be the absolute path to a file containing
 permitted server certificates, for use when setting up an encrypted connection.
 .vindex "&$host_address$&"
 The value of this option must be the absolute path to a file containing
 permitted server certificates, for use when setting up an encrypted connection.

-Alternatively, if you are using OpenSSL, you can set
+Alternatively,
+if you are using either GnuTLS version 3.3.6 (or later) or OpenSSL,
+you can set

 &%tls_verify_certificates%& to the name of a directory containing certificate
 &%tls_verify_certificates%& to the name of a directory containing certificate

-files. This does not work with GnuTLS; the option must be set to the name of a
-single file if you are using GnuTLS. The values of &$host$& and
+files.
+For earlier versions of GnuTLS the option must be set to the name of a
+single file.
+
+With OpenSSL the certificates specified
+explicitly
+either by file or directory
+are added to those given by the system default location.
+
+The values of &$host$& and

 &$host_address$& are set to the name and address of the server during the
 expansion of this option. See chapter &<<CHAPTLS>>& for details of TLS.
 
 &$host_address$& are set to the name and address of the server during the
 expansion of this option. See chapter &<<CHAPTLS>>& for details of TLS.
 


@@ -23444,7 +23475,7 @@ if neither tls_verify_hosts nor tls_try_verify_hosts are set
 and certificate verification fails the TLS connection is closed.
 
 
 and certificate verification fails the TLS connection is closed.
 
 

-.option tls_verify_hosts smtp "host list&!! unset
+.option tls_verify_hosts smtp "host list&!!" unset

 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which. on encrypted connections,
 .cindex "TLS" "server certificate verification"
 .cindex "certificate" "verification of server"
 This option gives a list of hosts for which. on encrypted connections,


@@ -25917,7 +25948,8 @@ There are some differences in usage when using GnuTLS instead of OpenSSL:
 
 .ilist
 The &%tls_verify_certificates%& option must contain the name of a file, not the
 
 .ilist
 The &%tls_verify_certificates%& option must contain the name of a file, not the

-name of a directory (for OpenSSL it can be either).
+name of a directory for GnuTLS versions before 3.3.6
+(for later versions, or OpenSSL, it can be either).

 .next
 The default value for &%tls_dhparam%& differs for historical reasons.
 .next
 .next
 The default value for &%tls_dhparam%& differs for historical reasons.
 .next


@@ -26114,7 +26146,8 @@ The GnuTLS library allows the caller to provide a "priority string", documented
 as part of the &[gnutls_priority_init]& function.  This is very similar to the
 ciphersuite specification in OpenSSL.
 
 as part of the &[gnutls_priority_init]& function.  This is very similar to the
 ciphersuite specification in OpenSSL.
 

-The &%tls_require_ciphers%& option is treated as the GnuTLS priority string.
+The &%tls_require_ciphers%& option is treated as the GnuTLS priority string
+and controls both protocols and ciphers.

 
 The &%tls_require_ciphers%& option is available both as an global option,
 controlling how Exim behaves as a server, and also as an option of the
 
 The &%tls_require_ciphers%& option is available both as an global option,
 controlling how Exim behaves as a server, and also as an option of the


@@ -26131,6 +26164,12 @@ installed on your system.  If you are using GnuTLS 3,
 &url(http://www.gnutls.org/manual/gnutls.html#Listing-the-ciphersuites-in-a-priority-string, then the example code)
 on that site can be used to test a given string.
 
 &url(http://www.gnutls.org/manual/gnutls.html#Listing-the-ciphersuites-in-a-priority-string, then the example code)
 on that site can be used to test a given string.
 

+For example:
+.code
+# Disable older versions of protocols
+tls_require_ciphers = NORMAL:%LATEST_RECORD_VERSION:-VERS-SSL3.0
+.endd
+

 Prior to Exim 4.80, an older API of GnuTLS was used, and Exim supported three
 additional options, "&%gnutls_require_kx%&", "&%gnutls_require_mac%&" and
 "&%gnutls_require_protocols%&".  &%tls_require_ciphers%& was an Exim list.
 Prior to Exim 4.80, an older API of GnuTLS was used, and Exim supported three
 additional options, "&%gnutls_require_kx%&", "&%gnutls_require_mac%&" and
 "&%gnutls_require_protocols%&".  &%tls_require_ciphers%& was an Exim list.


@@ -26181,8 +26220,11 @@ tls_privatekey = /some/file/name
 These options are, in fact, expanded strings, so you can make them depend on
 the identity of the client that is connected if you wish. The first file
 contains the server's X509 certificate, and the second contains the private key
 These options are, in fact, expanded strings, so you can make them depend on
 the identity of the client that is connected if you wish. The first file
 contains the server's X509 certificate, and the second contains the private key

-that goes with it. These files need to be readable by the Exim user, and must
-always be given as full path names. They can be the same file if both the
+that goes with it. These files need to be
+PEM format and readable by the Exim user, and must
+always be given as full path names.
+The key must not be password-protected.
+They can be the same file if both the

 certificate and the key are contained within it. If &%tls_privatekey%& is not
 set, or if its expansion is forced to fail or results in an empty string, this
 is assumed to be the case. The certificate file may also contain intermediate
 certificate and the key are contained within it. If &%tls_privatekey%& is not
 set, or if its expansion is forced to fail or results in an empty string, this
 is assumed to be the case. The certificate file may also contain intermediate


@@ -26309,7 +26351,7 @@ an identically named option for the &(smtp)& transport. In each case, the value
 of the option is expanded and must then be the name of a file that contains a
 CRL in PEM format.
 The downside is that clients have to periodically re-download a potentially huge
 of the option is expanded and must then be the name of a file that contains a
 CRL in PEM format.
 The downside is that clients have to periodically re-download a potentially huge

-file from every certificate authority the know of.
+file from every certificate authority they know of.

 
 The way with most moving parts at query time is Online Certificate
 Status Protocol (OCSP), where the client verifies the certificate
 
 The way with most moving parts at query time is Online Certificate
 Status Protocol (OCSP), where the client verifies the certificate


@@ -26531,7 +26573,7 @@ during TLS session handshake, to permit alternative values to be chosen:
 &%tls_verify_certificates%&
 .next
 .vindex "&%tls_ocsp_file%&"
 &%tls_verify_certificates%&
 .next
 .vindex "&%tls_ocsp_file%&"

-&%tls_verify_certificates%&
+&%tls_ocsp_file%&

 .endlist
 
 Great care should be taken to deal with matters of case, various injection
 .endlist
 
 Great care should be taken to deal with matters of case, various injection


@@ -28307,6 +28349,8 @@ can be appended; they appear within the called ACL in $acl_arg1 to $acl_arg9,
 and $acl_narg is set to the count of values.
 Previous values of these variables are restored after the call returns.
 The name and values are expanded separately.
 and $acl_narg is set to the count of values.
 Previous values of these variables are restored after the call returns.
 The name and values are expanded separately.

+Note that spaces in complex expansions which are used as arguments
+will act as argument separators.

 
 If the nested &%acl%& returns &"drop"& and the outer condition denies access,
 the connection is dropped. If it returns &"discard"&, the verb must be
 
 If the nested &%acl%& returns &"drop"& and the outer condition denies access,
 the connection is dropped. If it returns &"discard"&, the verb must be


@@ -30312,9 +30356,13 @@ av_scanner = cmdline:\
 .endd
 .vitem &%drweb%&
 .cindex "virus scanners" "DrWeb"
 .endd
 .vitem &%drweb%&
 .cindex "virus scanners" "DrWeb"

-The DrWeb daemon scanner (&url(http://www.sald.com/)) interface takes one
-argument, either a full path to a UNIX socket, or an IP address and port
-separated by white space, as in these examples:
+The DrWeb daemon scanner (&url(http://www.sald.com/)) interface
+takes one option,
+either a full path to a UNIX socket,
+or host and port specifiers separated by white space.
+The host may be a name or an IP address; the port is either a
+single number or a pair of numbers with a dash between.
+For example:

 .code
 av_scanner = drweb:/var/run/drwebd.sock
 av_scanner = drweb:192.168.2.20 31337
 .code
 av_scanner = drweb:/var/run/drwebd.sock
 av_scanner = drweb:192.168.2.20 31337


@@ -30322,6 +30370,17 @@ av_scanner = drweb:192.168.2.20 31337
 If you omit the argument, the default path &_/usr/local/drweb/run/drwebd.sock_&
 is used. Thanks to Alex Miller for contributing the code for this scanner.
 
 If you omit the argument, the default path &_/usr/local/drweb/run/drwebd.sock_&
 is used. Thanks to Alex Miller for contributing the code for this scanner.
 

+.vitem &%f-protd%&
+.cindex "virus scanners" "f-protd"
+The f-protd scanner is accessed via HTTP over TCP.
+One argument is taken, being a space-separated hostname and port number
+(or port-range).
+For example:
+.code
+av_scanner = f-protd:localhost 10200-10204
+.endd
+If you omit the argument, the default values show above are used.
+

 .vitem &%fsecure%&
 .cindex "virus scanners" "F-Secure"
 The F-Secure daemon scanner (&url(http://www.f-secure.com)) takes one
 .vitem &%fsecure%&
 .cindex "virus scanners" "F-Secure"
 The F-Secure daemon scanner (&url(http://www.f-secure.com)) takes one


@@ -32520,6 +32579,9 @@ headers_remove = return-receipt-to:acknowledge-to
 Multiple &%headers_remove%& options for a single router or transport can be
 specified; the arguments will append to a single header-names list.
 Each item is separately expanded.
 Multiple &%headers_remove%& options for a single router or transport can be
 specified; the arguments will append to a single header-names list.
 Each item is separately expanded.

+Note that colons in complex expansions which are used to
+form all or part of a &%headers_remove%& list
+will act as list separators.

 
 When &%headers_add%& or &%headers_remove%& is specified on a router,
 items are expanded at routing time,
 
 When &%headers_add%& or &%headers_remove%& is specified on a router,
 items are expanded at routing time,


@@ -35273,9 +35335,11 @@ given message, or all mail for a given user, or for a given host, for example.
 The input files can be in Exim log format or syslog format.
 If a matching log line is not associated with a specific message, it is
 included in &'exigrep'&'s output without any additional lines. The usage is:
 The input files can be in Exim log format or syslog format.
 If a matching log line is not associated with a specific message, it is
 included in &'exigrep'&'s output without any additional lines. The usage is:

+.new

 .display
 .display

-&`exigrep [-t<`&&'n'&&`>] [-I] [-l] [-v] <`&&'pattern'&&`> [<`&&'log file'&&`>] ...`&
+&`exigrep [-t<`&&'n'&&`>] [-I] [-l] [-M] [-v] <`&&'pattern'&&`> [<`&&'log file'&&`>] ...`&

 .endd
 .endd

+.wen

 If no log file names are given on the command line, the standard input is read.
 
 The &%-t%& argument specifies a number of seconds. It adds an additional
 If no log file names are given on the command line, the standard input is read.
 
 The &%-t%& argument specifies a number of seconds. It adds an additional


@@ -35295,6 +35359,21 @@ regular expression.
 The &%-v%& option inverts the matching condition. That is, a line is selected
 if it does &'not'& match the pattern.
 
 The &%-v%& option inverts the matching condition. That is, a line is selected
 if it does &'not'& match the pattern.
 

+.new
+The &%-M%& options means &"related messages"&. &'exigrep'& will show messages
+that are generated as a result/response to a message that &'exigrep'& matched
+normally.
+
+Example of &%-M%&:
+user_a sends a message to user_b, which generates a bounce back to user_b. If
+&'exigrep'& is used to search for &"user_a"&, only the first message will be
+displayed.  But if &'exigrep'& is used to search for &"user_b"&, the first and
+the second (bounce) message will be displayed. Using &%-M%& with &'exigrep'&
+when searching for &"user_a"& will show both messages since the bounce is
+&"related"& to or a &"result"& of the first message that was found by the
+search term.
+.wen
+

 If the location of a &'zcat'& command is known from the definition of
 ZCAT_COMMAND in &_Local/Makefile_&, &'exigrep'& automatically passes any file
 whose name ends in COMPRESS_SUFFIX through &'zcat'& as it searches it.
 If the location of a &'zcat'& command is known from the definition of
 ZCAT_COMMAND in &_Local/Makefile_&, &'exigrep'& automatically passes any file
 whose name ends in COMPRESS_SUFFIX through &'zcat'& as it searches it.