Do not exit when cwd has no name. Bug 2078

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

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index aab8c00d5ba8968d5072669ed23516a195d0c7f5..a9a048ecb3640fa30028675eece740f19011cebe 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -1667,6 +1667,9 @@ Symbolic links to the sources are installed in this directory, which is where
 the actual building takes place. In most cases, Exim can discover the machine
 architecture and operating system for itself, but the defaults can be
 overridden if necessary.
 the actual building takes place. In most cases, Exim can discover the machine
 architecture and operating system for itself, but the defaults can be
 overridden if necessary.

+.cindex compiler requirements
+.cindex compiler version
+A C99-capable compiler will be required for the build.

 
 
 .section "PCRE library" "SECTpcre"
 
 
 .section "PCRE library" "SECTpcre"


@@ -9964,7 +9967,7 @@ a regular expression, and a substitution string. For example:
 ${sg{abcdefabcdef}{abc}{xyz}}
 .endd
 yields &"xyzdefxyzdef"&. Because all three arguments are expanded before use,
 ${sg{abcdefabcdef}{abc}{xyz}}
 .endd
 yields &"xyzdefxyzdef"&. Because all three arguments are expanded before use,

-if any $ or \ characters are required in the regular expression or in the
+if any $, } or \ characters are required in the regular expression or in the

 substitution string, they have to be escaped. For example:
 .code
 ${sg{abcdef}{^(...)(...)\$}{\$2\$1}}
 substitution string, they have to be escaped. For example:
 .code
 ${sg{abcdef}{^(...)(...)\$}{\$2\$1}}


@@ -10115,7 +10118,15 @@ character. For example:
 .code
 ${addresses:>& Chief <ceo@up.stairs>, sec@base.ment (dogsbody)}
 .endd
 .code
 ${addresses:>& Chief <ceo@up.stairs>, sec@base.ment (dogsbody)}
 .endd

-expands to &`ceo@up.stairs&&sec@base.ment`&. Compare the &*address*& (singular)
+expands to &`ceo@up.stairs&&sec@base.ment`&. The string is expanded
+first, so if the expanded string starts with >, it may change the output
+separator unintentionally. This can be avoided by setting the output
+separator explicitly:
+.code
+${addresses:>:$h_from:}
+.endd
+
+Compare the &*address*& (singular)

 expansion item, which extracts the working address from a single RFC2822
 address. See the &*filter*&, &*map*&, and &*reduce*& items for ways of
 processing lists.
 expansion item, which extracts the working address from a single RFC2822
 address. See the &*filter*&, &*map*&, and &*reduce*& items for ways of
 processing lists.


@@ -12793,6 +12804,15 @@ argument, that is, the text that follows the command name, with leading white
 space removed. Following the introduction of &$smtp_command$&, this variable is
 somewhat redundant, but is retained for backwards compatibility.
 
 space removed. Following the introduction of &$smtp_command$&, this variable is
 somewhat redundant, but is retained for backwards compatibility.
 

+.new
+.vitem &$smtp_command_history$&
+.cindex SMTP "command history"
+.vindex "&$smtp_command_history$&"
+A comma-separated list (with no whitespace) of the most-recent SMTP commands
+received, in time-order left to right.  Only a limited number of commands
+are remembered.
+.wen
+

 .vitem &$smtp_count_at_connection_start$&
 .vindex "&$smtp_count_at_connection_start$&"
 This variable is set greater than zero only in processes spawned by the Exim
 .vitem &$smtp_count_at_connection_start$&
 .vindex "&$smtp_count_at_connection_start$&"
 This variable is set greater than zero only in processes spawned by the Exim


@@ -23786,7 +23806,9 @@ of the message. Its value must not be zero. See also &%final_timeout%&.
 .option dkim_private_key smtp string&!! unset
 .option dkim_canon smtp string&!! unset
 .option dkim_strict smtp string&!! unset
 .option dkim_private_key smtp string&!! unset
 .option dkim_canon smtp string&!! unset
 .option dkim_strict smtp string&!! unset

-.option dkim_sign_headers smtp string&!! unset
+.option dkim_sign_headers smtp string&!! "per RFC"
+.option dkim_hash smtp string&!! sha256
+.option dkim_identity smtp string&!! unset

 DKIM signing options.  For details see section &<<SECDKIMSIGN>>&.
 
 
 DKIM signing options.  For details see section &<<SECDKIMSIGN>>&.
 
 


@@ -24125,7 +24147,7 @@ This option provides a list of servers to which, provided they announce
 CHUNKING support, Exim will attempt to use BDAT commands rather than DATA.
 BDAT will not be used in conjunction with a transport filter.
 
 CHUNKING support, Exim will attempt to use BDAT commands rather than DATA.
 BDAT will not be used in conjunction with a transport filter.
 

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

 .cindex "fast open, TCP" "enabling, in client"
 .cindex "TCP Fast Open" "enabling, in client"
 .cindex "RFC 7413" "TCP Fast Open"
 .cindex "fast open, TCP" "enabling, in client"
 .cindex "TCP Fast Open" "enabling, in client"
 .cindex "RFC 7413" "TCP Fast Open"


@@ -24141,6 +24163,9 @@ as the initiator must present a cookie in the SYN segment.
 
 On (at least some) current Linux distributions the facility must be enabled
 in the kernel by the sysadmin before the support is usable.
 
 On (at least some) current Linux distributions the facility must be enabled
 in the kernel by the sysadmin before the support is usable.

+There is no option for control of the server side; if the system supports
+it it is always enebled.  Note that legthy operations in the connect ACL,
+such as DNSBL lookups, will still delay the emission of the SMTP banner.

 
 .option hosts_try_prdr smtp "host list&!!" *
 .cindex "PRDR" "enabling, optional in client"
 
 .option hosts_try_prdr smtp "host list&!!" *
 .cindex "PRDR" "enabling, optional in client"


@@ -36028,6 +36053,7 @@ the following table:
 &`SNI `&        server name indication from TLS client hello
 &`ST  `&        shadow transport name
 &`T   `&        on &`<=`& lines: message subject (topic)
 &`SNI `&        server name indication from TLS client hello
 &`ST  `&        shadow transport name
 &`T   `&        on &`<=`& lines: message subject (topic)

+&`TFO `&        connection took advantage of TCP Fast Open

 &`    `&        on &`=>`& &`**`& and &`==`& lines: transport name
 &`U   `&        local user or RFC 1413 identity
 &`X   `&        TLS cipher suite
 &`    `&        on &`=>`& &`**`& and &`==`& lines: transport name
 &`U   `&        local user or RFC 1413 identity
 &`X   `&        TLS cipher suite


@@ -36109,6 +36135,7 @@ selection marked by asterisks:
 &` incoming_interface         `&  local interface on <= and => lines
 &` incoming_port              `&  remote port on <= lines
 &`*lost_incoming_connection   `&  as it says (includes timeouts)
 &` incoming_interface         `&  local interface on <= and => lines
 &` incoming_port              `&  remote port on <= lines
 &`*lost_incoming_connection   `&  as it says (includes timeouts)

+&` millisec                   `&  millisecond timestamps and QT,DT,D times

 &` outgoing_interface         `&  local interface on => lines
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs
 &` outgoing_interface         `&  local interface on => lines
 &` outgoing_port              `&  add remote port to => lines
 &`*queue_run                  `&  start and end queue runs


@@ -36198,6 +36225,8 @@ process is started because &%queue_only%& is set or &%-odq%& was used.
 .cindex "log" "delivery duration"
 &%deliver_time%&: For each delivery, the amount of real time it has taken to
 perform the actual delivery is logged as DT=<&'time'&>, for example, &`DT=1s`&.
 .cindex "log" "delivery duration"
 &%deliver_time%&: For each delivery, the amount of real time it has taken to
 perform the actual delivery is logged as DT=<&'time'&>, for example, &`DT=1s`&.

+If millisecond logging is enabled, short times will be shown with greater
+precision, eg. &`DT=0.304`&.

 .next
 .cindex "log" "message size on delivery"
 .cindex "size" "of message"
 .next
 .cindex "log" "message size on delivery"
 .cindex "size" "of message"


@@ -36273,6 +36302,14 @@ important with the widening use of NAT (see RFC 2505).
 &%lost_incoming_connection%&: A log line is written when an incoming SMTP
 connection is unexpectedly dropped.
 .next
 &%lost_incoming_connection%&: A log line is written when an incoming SMTP
 connection is unexpectedly dropped.
 .next

+.new
+.cindex "log" "millisecond timestamps"
+.cindex millisecond logging
+.cindex timstamps "millisecond, in logs"
+&%millisec%&: Timestamps have a period and three decimal places of finer granularity
+appended to the seconds value.
+.wen
+.next

 .cindex "log" "outgoing interface"
 .cindex "log" "local interface"
 .cindex "log" "local address and port"
 .cindex "log" "outgoing interface"
 .cindex "log" "local interface"
 .cindex "log" "local address and port"


@@ -36311,6 +36348,8 @@ includes reception time as well as the delivery time for the current address.
 This means that it may be longer than the difference between the arrival and
 delivery log line times, because the arrival log line is not written until the
 message has been successfully received.
 This means that it may be longer than the difference between the arrival and
 delivery log line times, because the arrival log line is not written until the
 message has been successfully received.

+If millisecond logging is enabled, short times will be shown with greater
+precision, eg. &`QT=1.578s`&.

 .next
 &%queue_time_overall%&: The amount of time the message has been in the queue on
 the local host is logged as QT=<&'time'&> on &"Completed"& lines, for
 .next
 &%queue_time_overall%&: The amount of time the message has been in the queue on
 the local host is logged as QT=<&'time'&> on &"Completed"& lines, for


@@ -38499,13 +38538,15 @@ while expanding the remaining signing options.
 .wen
 If it is empty after expansion, DKIM signing is not done.
 
 .wen
 If it is empty after expansion, DKIM signing is not done.
 

-.option dkim_selector smtp string&!! unset
+.option dkim_selector smtp string list&!! unset

 This sets the key selector string.
 This sets the key selector string.

-You can use the &%$dkim_domain%& expansion variable to look up a matching selector.
-The result is put in the expansion
+.new
+After expansion, which can use &$dkim_domain$&, this can be a list.
+Each element in turn is put in the expansion

 variable &%$dkim_selector%& which may be used in the &%dkim_private_key%&
 option along with &%$dkim_domain%&.
 variable &%$dkim_selector%& which may be used in the &%dkim_private_key%&
 option along with &%$dkim_domain%&.

-If the option is empty after expansion, DKIM signing is not done.
+If the option is empty after expansion, DKIM signing is not done for this domain.
+.wen

 
 .option dkim_private_key smtp string&!! unset
 This sets the private key to use.
 
 .option dkim_private_key smtp string&!! unset
 This sets the private key to use.


@@ -38524,6 +38565,19 @@ is set.
 .endlist
 If the option is empty after expansion, DKIM signing is not done.
 
 .endlist
 If the option is empty after expansion, DKIM signing is not done.
 

+.new
+.option dkim_hash smtp string&!! sha256
+Can be set alternatively to &"sha1"& to use an alternate hash
+method.  Note that sha1 is now condidered insecure, and deprecated.
+
+.option dkim_identity smtp string&!! unset
+If set after expansion, the value is used to set an "i=" tag in
+the signing header.  The DKIM standards restrict the permissible
+syntax of this optional tag to a mail address, with possibly-empty
+local part, an @, and a domain identical to or subdomain of the "d="
+tag value.  Note that Exim does not check the value.
+.wen
+

 .option dkim_canon smtp string&!! unset
 This option sets the canonicalization method used when signing a message.
 The DKIM RFC currently supports two methods: "simple" and "relaxed".
 .option dkim_canon smtp string&!! unset
 This option sets the canonicalization method used when signing a message.
 The DKIM RFC currently supports two methods: "simple" and "relaxed".


@@ -38537,11 +38591,17 @@ either "1" or "true", Exim will defer. Otherwise Exim will send the message
 unsigned. You can use the &%$dkim_domain%& and &%$dkim_selector%& expansion
 variables here.
 
 unsigned. You can use the &%$dkim_domain%& and &%$dkim_selector%& expansion
 variables here.
 

-.option dkim_sign_headers smtp string&!! unset
-If set, this option must expand to (or be specified as) a colon-separated
-list of header names. Headers with these names will be included in the message
-signature.
-When unspecified, the header names recommended in RFC4871 will be used.
+.option dkim_sign_headers smtp string&!! "see below"
+If set, this option must expand to a colon-separated
+list of header names.
+.new
+Headers with these names, or the absence or such a header, will be included
+in the message signature.
+When unspecified, the header names listed in RFC4871 will be used,
+whether or not each header is present in the message.
+The default list is available for the expansion in the macro
+"_DKIM_SIGN_HEADERS".
+.wen

 
 
 .section "Verifying DKIM signatures in incoming mail" "SECID514"
 
 
 .section "Verifying DKIM signatures in incoming mail" "SECID514"


@@ -38552,7 +38612,7 @@ Verification of DKIM signatures in SMTP incoming email is implemented via the
 syntactically(!) correct signature in the incoming message.
 A missing ACL definition defaults to accept.
 If any ACL call does not accept, the message is not accepted.
 syntactically(!) correct signature in the incoming message.
 A missing ACL definition defaults to accept.
 If any ACL call does not accept, the message is not accepted.

-If a cutthrough delivery was in progress for the message it is
+If a cutthrough delivery was in progress for the message, that is

 summarily dropped (having wasted the transmission effort).
 
 To evaluate the signature in the ACL a large number of expansion variables
 summarily dropped (having wasted the transmission effort).
 
 To evaluate the signature in the ACL a large number of expansion variables