Add option to control use of shutdown by ${readsocket }. Bug 400

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 18e1710360e925b6fad6cbb422149325a0589049..054a135b93201d2fd8d25df47d99910e6177365f 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -52,7 +52,7 @@
 .set I   "    "
 
 .macro copyyear
 .set I   "    "
 
 .macro copyyear

-2016
+2017

 .endmacro
 
 . /////////////////////////////////////////////////////////////////////////////
 .endmacro
 
 . /////////////////////////////////////////////////////////////////////////////


@@ -3830,7 +3830,13 @@ remote host supports the ESMTP &_DSN_& extension.
 .oindex "&%-MCG%&"
 This option is not intended for use by external callers. It is used internally
 by Exim in conjunction with the &%-MC%& option. It signifies that an
 .oindex "&%-MCG%&"
 This option is not intended for use by external callers. It is used internally
 by Exim in conjunction with the &%-MC%& option. It signifies that an

-alternate queue is used, named by the following option.
+alternate queue is used, named by the following argument.
+
+.vitem &%-MCK%&
+.oindex "&%-MCK%&"
+This option is not intended for use by external callers. It is used internally
+by Exim in conjunction with the &%-MC%& option. It signifies that an
+remote host supports the ESMTP &_CHUNKING_& extension.

 
 .vitem &%-MCP%&
 .oindex "&%-MCP%&"
 
 .vitem &%-MCP%&
 .oindex "&%-MCP%&"


@@ -9761,7 +9767,7 @@ locks out the use of this expansion item in filter files.
 
 
 .vitem "&*${readsocket{*&<&'name'&>&*}{*&<&'request'&>&*}&&&
 
 
 .vitem "&*${readsocket{*&<&'name'&>&*}{*&<&'request'&>&*}&&&

-        {*&<&'timeout'&>&*}{*&<&'eol&~string'&>&*}{*&<&'fail&~string'&>&*}}*&"
+        {*&<&'options'&>&*}{*&<&'eol&~string'&>&*}{*&<&'fail&~string'&>&*}}*&"

 .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"


@@ -9791,6 +9797,17 @@ extend what can be done. Firstly, you can vary the timeout. For example:
 .code
 ${readsocket{/socket/name}{request string}{3s}}
 .endd
 .code
 ${readsocket{/socket/name}{request string}{3s}}
 .endd

+.new
+The third argument is a list of options, of which the first element is the timeout
+and must be present if the argument is given.
+Further elements are options of form &'name=value'&.
+One option type is currently recognised, defining whether (the default)
+or not a shutdown is done on the connection after sending the request.
+Example, to not do so (preferred, eg. by some webservers):
+.code
+${readsocket{/socket/name}{request string}{3s:shutdown=no}}
+.endd
+.wen

 A fourth argument allows you to change any newlines that are in the data
 that is read, in the same way as for &%readfile%& (see above). This example
 turns them into spaces:
 A fourth argument allows you to change any newlines that are in the data
 that is read, in the same way as for &%readfile%& (see above). This example
 turns them into spaces:


@@ -12257,7 +12274,7 @@ qualified host name. See also &$smtp_active_hostname$&.
        &$proxy_local_port$& &&&
        &$proxy_session$&
 These variables are only available when built with Proxy Protocol
        &$proxy_local_port$& &&&
        &$proxy_session$&
 These variables are only available when built with Proxy Protocol

-or Socks5 support
+or SOCKS5 support.

 For details see chapter &<<SECTproxyInbound>>&.
 
 .vitem &$prdr_requested$&
 For details see chapter &<<SECTproxyInbound>>&.
 
 .vitem &$prdr_requested$&


@@ -12607,6 +12624,13 @@ validating resolver (e.g. unbound, or bind with suitable configuration).
 If you have changed &%host_lookup_order%& so that &`bydns`& is not the first
 mechanism in the list, then this variable will be false.
 
 If you have changed &%host_lookup_order%& so that &`bydns`& is not the first
 mechanism in the list, then this variable will be false.
 

+.new
+This requires that your system resolver library support EDNS0 (and that
+DNSSEC flags exist in the system headers).  If the resolver silently drops
+all EDNS0 options, then this will have no effect.  OpenBSD's asr resolver
+is known to currently ignore EDNS0, documented in CAVEATS of asr_run(3).
+.wen
+

 
 .vitem &$sender_host_name$&
 .vindex "&$sender_host_name$&"
 
 .vitem &$sender_host_name$&
 .vindex "&$sender_host_name$&"


@@ -13528,6 +13552,7 @@ listed in more than one group.
 .section "Miscellaneous" "SECID96"
 .table2
 .row &%bi_command%&                  "to run for &%-bi%& command line option"
 .section "Miscellaneous" "SECID96"
 .table2
 .row &%bi_command%&                  "to run for &%-bi%& command line option"

+.row &%debug_store%&                 "do extra internal checks"

 .row &%disable_ipv6%&                "do no IPv6 processing"
 .row &%keep_malformed%&              "for broken files &-- should not happen"
 .row &%localhost_number%&            "for unique message ids in clusters"
 .row &%disable_ipv6%&                "do no IPv6 processing"
 .row &%keep_malformed%&              "for broken files &-- should not happen"
 .row &%localhost_number%&            "for unique message ids in clusters"


@@ -14416,6 +14441,15 @@ The CHUNKING extension (RFC3030) will be advertised in the EHLO message to
 these hosts.
 Hosts may use the BDAT command as an alternate to DATA.
 
 these hosts.
 Hosts may use the BDAT command as an alternate to DATA.
 

+.new
+.option debug_store main boolean &`false`&
+.cindex debugging "memory corruption"
+.cindex memory debugging
+This option, when true, enables extra checking in Exim's internal memory
+management.  For use when a memory corruption issue is being investigated,
+it should normally be left as default.
+.wen
+

 .option daemon_smtp_ports main string &`smtp`&
 .cindex "port" "for daemon"
 .cindex "TCP/IP" "setting listening ports"
 .option daemon_smtp_ports main string &`smtp`&
 .cindex "port" "for daemon"
 .cindex "TCP/IP" "setting listening ports"


@@ -14665,6 +14699,7 @@ record in the authoritative section is used instead.
 .option dns_use_edns0 main integer -1
 .cindex "DNS" "resolver options"
 .cindex "DNS" "EDNS0"
 .option dns_use_edns0 main integer -1
 .cindex "DNS" "resolver options"
 .cindex "DNS" "EDNS0"

+.cindex "DNS" "OpenBSD

 If this option is set to a non-negative number then Exim will initialise the
 DNS resolver library to either use or not use EDNS0 extensions, overriding
 the system default. A value of 0 coerces EDNS0 off, a value of 1 coerces EDNS0
 If this option is set to a non-negative number then Exim will initialise the
 DNS resolver library to either use or not use EDNS0 extensions, overriding
 the system default. A value of 0 coerces EDNS0 off, a value of 1 coerces EDNS0


@@ -14672,6 +14707,12 @@ on.
 
 If the resolver library does not support EDNS0 then this option has no effect.
 
 
 If the resolver library does not support EDNS0 then this option has no effect.
 

+.new
+OpenBSD's asr resolver routines are known to ignore the EDNS0 option; this
+means that DNSSEC will not work with Exim on that platform either, unless Exim
+is linked against an alternative DNS client library.
+.wen
+

 
 .option drop_cr main boolean false
 This is an obsolete option that is now a no-op. It used to affect the way Exim
 
 .option drop_cr main boolean false
 This is an obsolete option that is now a no-op. It used to affect the way Exim


@@ -16871,6 +16912,9 @@ generates any deliveries to files or pipes, or any new mail messages, the
 appropriate &%system_filter_..._transport%& option(s) must be set, to define
 which transports are to be used. Details of this facility are given in chapter
 &<<CHAPsystemfilter>>&.
 appropriate &%system_filter_..._transport%& option(s) must be set, to define
 which transports are to be used. Details of this facility are given in chapter
 &<<CHAPsystemfilter>>&.

+.new
+A forced expansion failure results in no filter operation.
+.wen

 
 
 .option system_filter_directory_transport main string&!! unset
 
 
 .option system_filter_directory_transport main string&!! unset


@@ -17113,7 +17157,8 @@ acceptable bound from 1024 to 2048.
 
 .option tls_eccurve main string&!! &`auto`&
 .cindex TLS "EC cryptography"
 
 .option tls_eccurve main string&!! &`auto`&
 .cindex TLS "EC cryptography"

-This option selects a EC curve for use by Exim.
+This option selects a EC curve for use by Exim when used with OpenSSL.
+It has no effect when Exim is used with GnuTLS.

 
 After expansion it must contain a valid EC curve parameter, such as
 &`prime256v1`&, &`secp384r1`&, or &`P-512`&. Consult your OpenSSL manual
 
 After expansion it must contain a valid EC curve parameter, such as
 &`prime256v1`&, &`secp384r1`&, or &`P-512`&. Consult your OpenSSL manual


@@ -25875,7 +25920,7 @@ running, the transport may get an IP for the name for its authentication
 check which does not match the connection peer IP.
 No authentication will then be done, despite the names being identical.
 
 check which does not match the connection peer IP.
 No authentication will then be done, despite the names being identical.
 

-For such cases use a separate transport which alwats authenticates.
+For such cases use a separate transport which always authenticates.

 .wen
 
 .cindex "AUTH" "on MAIL command"
 .wen
 
 .cindex "AUTH" "on MAIL command"


@@ -28093,6 +28138,11 @@ run. A &"discard"& return from the DATA or the non-SMTP ACL discards all the
 remaining recipients. The &"discard"& return is not permitted for the
 &%acl_smtp_predata%& ACL.
 
 remaining recipients. The &"discard"& return is not permitted for the
 &%acl_smtp_predata%& ACL.
 

+.new
+If the ACL for VRFY returns &"accept"&, a recipient verify (without callout)
+is done on the address and the result determines the SMTP response.
+.wen
+

 
 .cindex "&[local_scan()]& function" "when all recipients discarded"
 The &[local_scan()]& function is always run, even if there are no remaining
 
 .cindex "&[local_scan()]& function" "when all recipients discarded"
 The &[local_scan()]& function is always run, even if there are no remaining


@@ -28912,7 +28962,11 @@ message body.
 Cutthrough delivery is not supported via transport-filters or when DKIM signing
 of outgoing messages is done, because it sends data to the ultimate destination
 before the entire message has been received from the source.
 Cutthrough delivery is not supported via transport-filters or when DKIM signing
 of outgoing messages is done, because it sends data to the ultimate destination
 before the entire message has been received from the source.

-It is not supported for messages received with the SMTP PRDR option in use.
+It is not supported for messages received with the SMTP PRDR
+.new
+or CHUNKING
+.wen
+options in use.

 
 Should the ultimate destination system positively accept or reject the mail,
 a corresponding indication is given to the source system and nothing is queued.
 
 Should the ultimate destination system positively accept or reject the mail,
 a corresponding indication is given to the source system and nothing is queued.


@@ -29763,6 +29817,15 @@ to avoid doing it more than once per message.
 .cindex "&%verify%& ACL condition"
 This is a variation of the previous option, in which a modified address is
 verified as a sender.
 .cindex "&%verify%& ACL condition"
 This is a variation of the previous option, in which a modified address is
 verified as a sender.

+
+.new
+Note that '/' is legal in local-parts; if the address may have such
+(eg. is generated from the received message)
+they must be protected from the options parsing by doubling:
+.code
+verify = sender=${sg{${address:$h_sender:}}{/}{//}}
+.endd
+.wen

 .endlist
 
 
 .endlist
 
 


@@ -36028,7 +36091,7 @@ The latter can be disabled by turning off the &%outgoing_interface%& option.
 &%proxy%&: The internal (closest to the system running Exim) IP address
 of the proxy, tagged by PRX=, on the &"<="& line for a message accepted
 on a proxied connection
 &%proxy%&: The internal (closest to the system running Exim) IP address
 of the proxy, tagged by PRX=, on the &"<="& line for a message accepted
 on a proxied connection

-or the &"=>"& line for a message delivered on a proxied connection..
+or the &"=>"& line for a message delivered on a proxied connection.

 See &<<SECTproxyInbound>>& for more information.
 .next
 .cindex "log" "incoming remote port"
 See &<<SECTproxyInbound>>& for more information.
 .next
 .cindex "log" "incoming remote port"


@@ -37888,9 +37951,8 @@ lock will be lost at the instant of rename.
 .next
 .vindex "&$body_linecount$&"
 If you change the number of lines in the file, the value of
 .next
 .vindex "&$body_linecount$&"
 If you change the number of lines in the file, the value of

-&$body_linecount$&, which is stored in the -H file, will be incorrect. At
-present, this value is not used by Exim, but there is no guarantee that this
-will always be the case.
+&$body_linecount$&, which is stored in the -H file, will be incorrect and can
+cause incomplete transmission of messages or undeliverable messages.

 .next
 If the message is in MIME format, you must take care not to break it.
 .next
 .next
 If the message is in MIME format, you must take care not to break it.
 .next


@@ -38519,6 +38581,13 @@ recorded in an ACL (example is below).
 Use of a proxy is enabled by setting the &%hosts_proxy%&
 main configuration option to a hostlist; connections from these
 hosts will use Proxy Protocol.
 Use of a proxy is enabled by setting the &%hosts_proxy%&
 main configuration option to a hostlist; connections from these
 hosts will use Proxy Protocol.

+Exim supports both version 1 and version 2 of the Proxy Protocol and
+automatically determines which version is in use.
+
+The Proxy Protocol header is the first data received on a TCP connection
+and is inserted before any TLS-on-connect handshake from the client; Exim
+negotiates TLS between Exim-as-server and the remote client, not between
+Exim and the proxy server.

 
 The following expansion variables are usable
 (&"internal"& and &"external"& here refer to the interfaces
 
 The following expansion variables are usable
 (&"internal"& and &"external"& here refer to the interfaces


@@ -38639,6 +38708,12 @@ Exim has support for Internationalised mail names.
 To include this it must be built with SUPPORT_I18N and the libidn library.
 Standards supported are RFCs 2060, 5890, 6530 and 6533.
 
 To include this it must be built with SUPPORT_I18N and the libidn library.
 Standards supported are RFCs 2060, 5890, 6530 and 6533.
 

+.new
+If Exim is built with SUPPORT_I18N_2008 (in addition to SUPPORT_I18N, not
+instead of it) then IDNA2008 is supported; this adds an extra library
+requirement, upon libidn2.
+.wen
+

 .section "MTA operations" SECTi18nMTA
 .cindex SMTPUTF8 "ESMTP option"
 The main configuration option &%smtputf8_advertise_hosts%& specifies
 .section "MTA operations" SECTi18nMTA
 .cindex SMTPUTF8 "ESMTP option"
 The main configuration option &%smtputf8_advertise_hosts%& specifies