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mirror of https://github.com/vdukhovni/postfix synced 2025-08-30 05:38:06 +00:00

postfix-3.5.23

This commit is contained in:
Wietse Venema 2023-12-22 00:00:00 -05:00 committed by Viktor Dukhovni
parent 86b885a4e6
commit f75140fe85
13 changed files with 471 additions and 180 deletions

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@ -25399,3 +25399,17 @@ Apologies for any names omitted.
delimiter. Fixed by restoring Postfix 2.10 behavior to use
a configured recipient delimiter value. Reported by Tod
A. Sandman. Files: proto/postconf.proto, local/local_expand.c.
20231221
Security: with "smtpd_forbid_bare_newline = yes" (default
"no" for Postfix < 3.9), reply with "Error: bare <LF>
received" and disconnect when an SMTP client sends a line
ending in <LF>, violating the RFC 5321 requirement that
lines must end in <CR><LF>. This prevents SMTP smuggling
attacks that target a recipient at a Postfix server. For
backwards compatibility, local clients are excluded by
default with "smtpd_forbid_bare_newline_exclusions =
$mynetworks". Files: mantools/postlink, proto/postconf.proto,
global/mail_params.h, global/smtp_stream.c, global/smtp_stream.h,
smtpd/smtpd.c.

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@ -25,6 +25,31 @@ more recent Eclipse Public License 2.0. Recipients can choose to take
the software under the license of their choice. Those who are more
comfortable with the IPL can continue with that license.
Major changes with Postfix 3.5.23
=================================
Security: the Postfix SMTP server optionally disconnects a remote
SMTP client that sends a 'bare newline' line ending in SMTP. This
prevents an SMTP smuggling attack on recipients at a Postfix server.
For background, see https://www.postfix.org/smtp-smuggling.html
Sites concerned about SMTP smuggling attacks should enable this
feature in Internet-facing Postfix servers. For compatibility with
non-standard clients, Postfix by default excludes clients in
mynetworks from this countermeasure.
The recommended settings are:
# Optionally disconnect remote SMTP clients that send bare newlines,
# but allow local clients with non-standard SMTP implementations
# such as netcat, fax machines, or load balancer health checks.
#
smtpd_forbid_bare_newline = no
smtpd_forbid_bare_newline_exclusions = $mynetworks
This feature is back-ported from Postfix 3.9, with the difference
that "smtpd_forbid_bare_newline = no" by default.
Major changes with Postfix 3.5.20
=================================

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@ -15047,6 +15047,65 @@ This feature is available in Postfix 2.0 and later.
</p>
</DD>
<DT><b><a name="smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a>
(default: Postfix &lt; 3.9: no)</b></DT><DD>
<p> Reply with "Error: bare &lt;LF&gt; received" and disconnect
when a remote SMTP client sends a line ending in &lt;LF&gt;, violating
the <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a> requirement that lines must end in &lt;CR&gt;&lt;LF&gt;.
This feature is disbled by default with Postfix &lt; 3.9. Use
<a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a> to exclude non-standard clients
such as netcat. Specify "<a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> = no" to disable
(not recommended for an Internet-connected MTA). </p>
<p> See <a href="https://www.postfix.org/smtp-smuggling.html">
https://www.postfix.org/smtp-smuggling.html</a> for details.
<p> Example: </p>
<blockquote>
<pre>
# Disconnect remote SMTP clients that send bare newlines, but allow
# local clients with non-standard SMTP implementations such as netcat,
# fax machines, or load balancer health checks.
#
<a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> = yes
<a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a> = $<a href="postconf.5.html#mynetworks">mynetworks</a>
</pre>
</blockquote>
<p> This feature is available in Postfix &ge; 3.9, 3.8.4, 3.7.9,
3.6.13, and 3.5.23. </p>
</DD>
<DT><b><a name="smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a>
(default: $<a href="postconf.5.html#mynetworks">mynetworks</a>)</b></DT><DD>
<p> Exclude the specified clients from <a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a>
enforcement. It uses the same syntax and parent-domain matching
behavior as <a href="postconf.5.html#mynetworks">mynetworks</a>. </p>
<p> Example: </p>
<blockquote>
<pre>
# Disconnect remote SMTP clients that send bare newlines, but allow
# local clients with non-standard SMTP implementations such as netcat,
# fax machines, or load balancer health checks.
#
<a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> = yes
<a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a> = $<a href="postconf.5.html#mynetworks">mynetworks</a>
</pre>
</blockquote>
<p> This feature is available in Postfix &ge; 3.9, 3.8.4, 3.7.9,
3.6.13, and 3.5.23. </p>
</DD>
<DT><b><a name="smtpd_forbid_unauth_pipelining">smtpd_forbid_unauth_pipelining</a>

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@ -612,12 +612,12 @@ SMTPD(8) SMTPD(8)
tialization functions.
<b>OBSOLETE STARTTLS CONTROLS</b>
The following configuration parameters exist for compatibility with
Postfix versions before 2.3. Support for these will be removed in a
The following configuration parameters exist for compatibility with
Postfix versions before 2.3. Support for these will be removed in a
future release.
<b><a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> (no)</b>
Opportunistic TLS: announce STARTTLS support to remote SMTP
Opportunistic TLS: announce STARTTLS support to remote SMTP
clients, but do not require that clients use TLS encryption.
<b><a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a> (no)</b>
@ -625,92 +625,92 @@ SMTPD(8) SMTPD(8)
and require that clients use TLS encryption.
<b><a href="postconf.5.html#smtpd_tls_cipherlist">smtpd_tls_cipherlist</a> (empty)</b>
Obsolete Postfix &lt; 2.3 control for the Postfix SMTP server TLS
Obsolete Postfix &lt; 2.3 control for the Postfix SMTP server TLS
cipher list.
<b>SMTPUTF8 CONTROLS</b>
Preliminary SMTPUTF8 support is introduced with Postfix 3.0.
<b><a href="postconf.5.html#smtputf8_enable">smtputf8_enable</a> (yes)</b>
Enable preliminary SMTPUTF8 support for the protocols described
Enable preliminary SMTPUTF8 support for the protocols described
in <a href="http://tools.ietf.org/html/rfc6531">RFC 6531</a>..6533.
<b><a href="postconf.5.html#strict_smtputf8">strict_smtputf8</a> (no)</b>
Enable stricter enforcement of the SMTPUTF8 protocol.
<b><a href="postconf.5.html#smtputf8_autodetect_classes">smtputf8_autodetect_classes</a> (sendmail, verify)</b>
Detect that a message requires SMTPUTF8 support for the speci-
Detect that a message requires SMTPUTF8 support for the speci-
fied mail origin classes.
Available in Postfix version 3.2 and later:
<b><a href="postconf.5.html#enable_idna2003_compatibility">enable_idna2003_compatibility</a> (no)</b>
Enable 'transitional' compatibility between IDNA2003 and
IDNA2008, when converting UTF-8 domain names to/from the ASCII
Enable 'transitional' compatibility between IDNA2003 and
IDNA2008, when converting UTF-8 domain names to/from the ASCII
form that is used for DNS lookups.
<b>VERP SUPPORT CONTROLS</b>
With VERP style delivery, each recipient of a message receives a cus-
tomized copy of the message with his/her own recipient address encoded
With VERP style delivery, each recipient of a message receives a cus-
tomized copy of the message with his/her own recipient address encoded
in the envelope sender address. The <a href="VERP_README.html">VERP_README</a> file describes config-
uration and operation details of Postfix support for variable envelope
return path addresses. VERP style delivery is requested with the SMTP
XVERP command or with the "sendmail -V" command-line option and is
uration and operation details of Postfix support for variable envelope
return path addresses. VERP style delivery is requested with the SMTP
XVERP command or with the "sendmail -V" command-line option and is
available in Postfix version 1.1 and later.
<b><a href="postconf.5.html#default_verp_delimiters">default_verp_delimiters</a> (+=)</b>
The two default VERP delimiter characters.
<b><a href="postconf.5.html#verp_delimiter_filter">verp_delimiter_filter</a> (-=+)</b>
The characters Postfix accepts as VERP delimiter characters on
The characters Postfix accepts as VERP delimiter characters on
the Postfix <a href="sendmail.1.html"><b>sendmail</b>(1)</a> command line and in SMTP commands.
Available in Postfix version 1.1 and 2.0:
<b><a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a> ($<a href="postconf.5.html#mynetworks">mynetworks</a>)</b>
What remote SMTP clients are allowed to specify the XVERP com-
What remote SMTP clients are allowed to specify the XVERP com-
mand.
Available in Postfix version 2.1 and later:
<b><a href="postconf.5.html#smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> ($<a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a>)</b>
What remote SMTP clients are allowed to specify the XVERP com-
What remote SMTP clients are allowed to specify the XVERP com-
mand.
<b>TROUBLE SHOOTING CONTROLS</b>
The <a href="DEBUG_README.html">DEBUG_README</a> document describes how to debug parts of the Postfix
mail system. The methods vary from making the software log a lot of
The <a href="DEBUG_README.html">DEBUG_README</a> document describes how to debug parts of the Postfix
mail system. The methods vary from making the software log a lot of
detail, to running some daemon processes under control of a call tracer
or debugger.
<b><a href="postconf.5.html#debug_peer_level">debug_peer_level</a> (2)</b>
The increment in verbose logging level when a remote client or
The increment in verbose logging level when a remote client or
server matches a pattern in the <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> parameter.
<b><a href="postconf.5.html#debug_peer_list">debug_peer_list</a> (empty)</b>
Optional list of remote client or server hostname or network
Optional list of remote client or server hostname or network
address patterns that cause the verbose logging level to
increase by the amount specified in $<a href="postconf.5.html#debug_peer_level">debug_peer_level</a>.
<b><a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> (postmaster)</b>
The recipient of postmaster notifications about mail delivery
The recipient of postmaster notifications about mail delivery
problems that are caused by policy, resource, software or proto-
col errors.
<b><a href="postconf.5.html#internal_mail_filter_classes">internal_mail_filter_classes</a> (empty)</b>
What categories of Postfix-generated mail are subject to
before-queue content inspection by <a href="postconf.5.html#non_smtpd_milters">non_smtpd_milters</a>,
What categories of Postfix-generated mail are subject to
before-queue content inspection by <a href="postconf.5.html#non_smtpd_milters">non_smtpd_milters</a>,
<a href="postconf.5.html#header_checks">header_checks</a> and <a href="postconf.5.html#body_checks">body_checks</a>.
<b><a href="postconf.5.html#notify_classes">notify_classes</a> (resource, software)</b>
The list of error classes that are reported to the postmaster.
<b><a href="postconf.5.html#smtpd_reject_footer">smtpd_reject_footer</a> (empty)</b>
Optional information that is appended after each Postfix SMTP
Optional information that is appended after each Postfix SMTP
server 4XX or 5XX response.
<b><a href="postconf.5.html#soft_bounce">soft_bounce</a> (no)</b>
Safety net to keep mail queued that would otherwise be returned
Safety net to keep mail queued that would otherwise be returned
to the sender.
Available in Postfix version 2.1 and later:
@ -721,109 +721,109 @@ SMTPD(8) SMTPD(8)
Available in Postfix version 2.10 and later:
<b><a href="postconf.5.html#smtpd_log_access_permit_actions">smtpd_log_access_permit_actions</a> (empty)</b>
Enable logging of the named "permit" actions in SMTP server
access lists (by default, the SMTP server logs "reject" actions
Enable logging of the named "permit" actions in SMTP server
access lists (by default, the SMTP server logs "reject" actions
but not "permit" actions).
<b>KNOWN VERSUS UNKNOWN RECIPIENT CONTROLS</b>
As of Postfix version 2.0, the SMTP server rejects mail for unknown
As of Postfix version 2.0, the SMTP server rejects mail for unknown
recipients. This prevents the mail queue from clogging up with undeliv-
erable MAILER-DAEMON messages. Additional information on this topic is
erable MAILER-DAEMON messages. Additional information on this topic is
in the <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a> and <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> documents.
<b><a href="postconf.5.html#show_user_unknown_table_name">show_user_unknown_table_name</a> (yes)</b>
Display the name of the recipient table in the "User unknown"
Display the name of the recipient table in the "User unknown"
responses.
<b><a href="postconf.5.html#canonical_maps">canonical_maps</a> (empty)</b>
Optional address mapping lookup tables for message headers and
Optional address mapping lookup tables for message headers and
envelopes.
<b><a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> (empty)</b>
Optional address mapping lookup tables for envelope and header
Optional address mapping lookup tables for envelope and header
recipient addresses.
<b><a href="postconf.5.html#sender_canonical_maps">sender_canonical_maps</a> (empty)</b>
Optional address mapping lookup tables for envelope and header
Optional address mapping lookup tables for envelope and header
sender addresses.
Parameters concerning known/unknown local recipients:
<b><a href="postconf.5.html#mydestination">mydestination</a> ($<a href="postconf.5.html#myhostname">myhostname</a>, localhost.$<a href="postconf.5.html#mydomain">mydomain</a>, localhost)</b>
The list of domains that are delivered via the $<a href="postconf.5.html#local_transport">local_transport</a>
The list of domains that are delivered via the $<a href="postconf.5.html#local_transport">local_transport</a>
mail delivery transport.
<b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a> (all)</b>
The network interface addresses that this mail system receives
The network interface addresses that this mail system receives
mail on.
<b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> (empty)</b>
The network interface addresses that this mail system receives
The network interface addresses that this mail system receives
mail on by way of a proxy or network address translation unit.
<b><a href="postconf.5.html#inet_protocols">inet_protocols</a> (all)</b>
The Internet protocols Postfix will attempt to use when making
The Internet protocols Postfix will attempt to use when making
or accepting connections.
<b><a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> (<a href="proxymap.8.html">proxy</a>:unix:passwd.byname $<a href="postconf.5.html#alias_maps">alias_maps</a>)</b>
Lookup tables with all names or addresses of local recipients: a
recipient address is local when its domain matches $<a href="postconf.5.html#mydestination">mydestina</a>-
recipient address is local when its domain matches $<a href="postconf.5.html#mydestination">mydestina</a>-
<a href="postconf.5.html#mydestination">tion</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>.
<b><a href="postconf.5.html#unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> (550)</b>
The numerical Postfix SMTP server response code when a recipient
address is local, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> specifies a list of
address is local, and $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> specifies a list of
lookup tables that does not match the recipient.
Parameters concerning known/unknown recipients of relay destinations:
<b><a href="postconf.5.html#relay_domains">relay_domains</a> (Postfix</b> &gt;<b>= 3.0: empty, Postfix</b> &lt; <b>3.0: $<a href="postconf.5.html#mydestination">mydestination</a>)</b>
What destination domains (and subdomains thereof) this system
What destination domains (and subdomains thereof) this system
will relay mail to.
<b><a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> (empty)</b>
Optional lookup tables with all valid addresses in the domains
Optional lookup tables with all valid addresses in the domains
that match $<a href="postconf.5.html#relay_domains">relay_domains</a>.
<b><a href="postconf.5.html#unknown_relay_recipient_reject_code">unknown_relay_recipient_reject_code</a> (550)</b>
The numerical Postfix SMTP server reply code when a recipient
address matches $<a href="postconf.5.html#relay_domains">relay_domains</a>, and <a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> speci-
fies a list of lookup tables that does not match the recipient
The numerical Postfix SMTP server reply code when a recipient
address matches $<a href="postconf.5.html#relay_domains">relay_domains</a>, and <a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> speci-
fies a list of lookup tables that does not match the recipient
address.
Parameters concerning known/unknown recipients in virtual alias
Parameters concerning known/unknown recipients in virtual alias
domains:
<b><a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> ($<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>)</b>
Postfix is final destination for the specified list of virtual
alias domains, that is, domains for which all addresses are
Postfix is final destination for the specified list of virtual
alias domains, that is, domains for which all addresses are
aliased to addresses in other local or remote domains.
<b><a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> ($<a href="postconf.5.html#virtual_maps">virtual_maps</a>)</b>
Optional lookup tables that alias specific mail addresses or
Optional lookup tables that alias specific mail addresses or
domains to other local or remote address.
<b><a href="postconf.5.html#unknown_virtual_alias_reject_code">unknown_virtual_alias_reject_code</a> (550)</b>
The Postfix SMTP server reply code when a recipient address
matches $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, and $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> speci-
fies a list of lookup tables that does not match the recipient
The Postfix SMTP server reply code when a recipient address
matches $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>, and $<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> speci-
fies a list of lookup tables that does not match the recipient
address.
Parameters concerning known/unknown recipients in virtual mailbox
domains:
<b><a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> ($<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>)</b>
Postfix is final destination for the specified list of domains;
mail is delivered via the $<a href="postconf.5.html#virtual_transport">virtual_transport</a> mail delivery
Postfix is final destination for the specified list of domains;
mail is delivered via the $<a href="postconf.5.html#virtual_transport">virtual_transport</a> mail delivery
transport.
<b><a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> (empty)</b>
Optional lookup tables with all valid addresses in the domains
Optional lookup tables with all valid addresses in the domains
that match $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>.
<b><a href="postconf.5.html#unknown_virtual_mailbox_reject_code">unknown_virtual_mailbox_reject_code</a> (550)</b>
The Postfix SMTP server reply code when a recipient address
matches $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, and $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>
The Postfix SMTP server reply code when a recipient address
matches $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>, and $<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>
specifies a list of lookup tables that does not match the recip-
ient address.
@ -832,7 +832,7 @@ SMTPD(8) SMTPD(8)
control client request rates.
<b><a href="postconf.5.html#line_length_limit">line_length_limit</a> (2048)</b>
Upon input, long lines are chopped up into pieces of at most
Upon input, long lines are chopped up into pieces of at most
this length; upon delivery, long lines are reconstructed.
<b><a href="postconf.5.html#queue_minfree">queue_minfree</a> (0)</b>
@ -840,58 +840,58 @@ SMTPD(8) SMTPD(8)
tem that is needed to receive mail.
<b><a href="postconf.5.html#message_size_limit">message_size_limit</a> (10240000)</b>
The maximal size in bytes of a message, including envelope
The maximal size in bytes of a message, including envelope
information.
<b><a href="postconf.5.html#smtpd_recipient_limit">smtpd_recipient_limit</a> (1000)</b>
The maximal number of recipients that the Postfix SMTP server
The maximal number of recipients that the Postfix SMTP server
accepts per message delivery request.
<b><a href="postconf.5.html#smtpd_timeout">smtpd_timeout</a> (normal: 300s, overload: 10s)</b>
The time limit for sending a Postfix SMTP server response and
The time limit for sending a Postfix SMTP server response and
for receiving a remote SMTP client request.
<b><a href="postconf.5.html#smtpd_history_flush_threshold">smtpd_history_flush_threshold</a> (100)</b>
The maximal number of lines in the Postfix SMTP server command
history before it is flushed upon receipt of EHLO, RSET, or end
The maximal number of lines in the Postfix SMTP server command
history before it is flushed upon receipt of EHLO, RSET, or end
of DATA.
Available in Postfix version 2.3 and later:
<b><a href="postconf.5.html#smtpd_peername_lookup">smtpd_peername_lookup</a> (yes)</b>
Attempt to look up the remote SMTP client hostname, and verify
Attempt to look up the remote SMTP client hostname, and verify
that the name matches the client IP address.
The per SMTP client connection count and request rate limits are imple-
mented in co-operation with the <a href="anvil.8.html"><b>anvil</b>(8)</a> service, and are available in
mented in co-operation with the <a href="anvil.8.html"><b>anvil</b>(8)</a> service, and are available in
Postfix version 2.2 and later.
<b><a href="postconf.5.html#smtpd_client_connection_count_limit">smtpd_client_connection_count_limit</a> (50)</b>
How many simultaneous connections any client is allowed to make
How many simultaneous connections any client is allowed to make
to this service.
<b><a href="postconf.5.html#smtpd_client_connection_rate_limit">smtpd_client_connection_rate_limit</a> (0)</b>
The maximal number of connection attempts any client is allowed
The maximal number of connection attempts any client is allowed
to make to this service per time unit.
<b><a href="postconf.5.html#smtpd_client_message_rate_limit">smtpd_client_message_rate_limit</a> (0)</b>
The maximal number of message delivery requests that any client
is allowed to make to this service per time unit, regardless of
The maximal number of message delivery requests that any client
is allowed to make to this service per time unit, regardless of
whether or not Postfix actually accepts those messages.
<b><a href="postconf.5.html#smtpd_client_recipient_rate_limit">smtpd_client_recipient_rate_limit</a> (0)</b>
The maximal number of recipient addresses that any client is
allowed to send to this service per time unit, regardless of
The maximal number of recipient addresses that any client is
allowed to send to this service per time unit, regardless of
whether or not Postfix actually accepts those recipients.
<b><a href="postconf.5.html#smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a> ($<a href="postconf.5.html#mynetworks">mynetworks</a>)</b>
Clients that are excluded from smtpd_client_*_count/rate_limit
Clients that are excluded from smtpd_client_*_count/rate_limit
restrictions.
Available in Postfix version 2.3 and later:
<b><a href="postconf.5.html#smtpd_client_new_tls_session_rate_limit">smtpd_client_new_tls_session_rate_limit</a> (0)</b>
The maximal number of new (i.e., uncached) TLS sessions that a
The maximal number of new (i.e., uncached) TLS sessions that a
remote SMTP client is allowed to negotiate with this service per
time unit.
@ -899,74 +899,85 @@ SMTPD(8) SMTPD(8)
<b><a href="postconf.5.html#smtpd_per_record_deadline">smtpd_per_record_deadline</a> (normal: no, overload: yes)</b>
Change the behavior of the <a href="postconf.5.html#smtpd_timeout">smtpd_timeout</a> and <a href="postconf.5.html#smtpd_starttls_timeout">smtpd_start</a>-
<a href="postconf.5.html#smtpd_starttls_timeout">tls_timeout</a> time limits, from a time limit per read or write
system call, to a time limit to send or receive a complete
record (an SMTP command line, SMTP response line, SMTP message
<a href="postconf.5.html#smtpd_starttls_timeout">tls_timeout</a> time limits, from a time limit per read or write
system call, to a time limit to send or receive a complete
record (an SMTP command line, SMTP response line, SMTP message
content line, or TLS protocol message).
Available in Postfix version 3.1 and later:
<b><a href="postconf.5.html#smtpd_client_auth_rate_limit">smtpd_client_auth_rate_limit</a> (0)</b>
The maximal number of AUTH commands that any client is allowed
to send to this service per time unit, regardless of whether or
The maximal number of AUTH commands that any client is allowed
to send to this service per time unit, regardless of whether or
not Postfix actually accepts those commands.
Available in Postfix 3.9, 3.8.1, 3.7.6, 3.6.10, 3.5.20 and later:
<b><a href="postconf.5.html#smtpd_forbid_unauth_pipelining">smtpd_forbid_unauth_pipelining</a> (Postfix</b> &gt;<b>= 3.9: yes)</b>
Disconnect remote SMTP clients that violate <a href="https://tools.ietf.org/html/rfc2920">RFC 2920</a> (or 5321)
Disconnect remote SMTP clients that violate <a href="http://tools.ietf.org/html/rfc2920">RFC 2920</a> (or 5321)
command pipelining constraints.
Available in Postfix 3.9, 3.8.4, 3.7.9, 3.6.13, 3.5.23 and later:
<b><a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> (Postfix</b> &lt; <b>3.9: no)</b>
Reply with "Error: bare &lt;LF&gt; received" and disconnect when a
remote SMTP client sends a line ending in &lt;LF&gt;, violating the
<a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a> requirement that lines must end in &lt;CR&gt;&lt;LF&gt;.
<b><a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a> ($<a href="postconf.5.html#mynetworks">mynetworks</a>)</b>
Exclude the specified clients from <a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a>
enforcement.
<b>TARPIT CONTROLS</b>
When a remote SMTP client makes errors, the Postfix SMTP server can
insert delays before responding. This can help to slow down run-away
software. The behavior is controlled by an error counter that counts
When a remote SMTP client makes errors, the Postfix SMTP server can
insert delays before responding. This can help to slow down run-away
software. The behavior is controlled by an error counter that counts
the number of errors within an SMTP session that a client makes without
delivering mail.
<b><a href="postconf.5.html#smtpd_error_sleep_time">smtpd_error_sleep_time</a> (1s)</b>
With Postfix version 2.1 and later: the SMTP server response
delay after a client has made more than $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a>
errors, and fewer than $<a href="postconf.5.html#smtpd_hard_error_limit">smtpd_hard_error_limit</a> errors, without
With Postfix version 2.1 and later: the SMTP server response
delay after a client has made more than $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a>
errors, and fewer than $<a href="postconf.5.html#smtpd_hard_error_limit">smtpd_hard_error_limit</a> errors, without
delivering mail.
<b><a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> (10)</b>
The number of errors a remote SMTP client is allowed to make
without delivering mail before the Postfix SMTP server slows
The number of errors a remote SMTP client is allowed to make
without delivering mail before the Postfix SMTP server slows
down all its responses.
<b><a href="postconf.5.html#smtpd_hard_error_limit">smtpd_hard_error_limit</a> (normal: 20, overload: 1)</b>
The maximal number of errors a remote SMTP client is allowed to
The maximal number of errors a remote SMTP client is allowed to
make without delivering mail.
<b><a href="postconf.5.html#smtpd_junk_command_limit">smtpd_junk_command_limit</a> (normal: 100, overload: 1)</b>
The number of junk commands (NOOP, VRFY, ETRN or RSET) that a
remote SMTP client can send before the Postfix SMTP server
The number of junk commands (NOOP, VRFY, ETRN or RSET) that a
remote SMTP client can send before the Postfix SMTP server
starts to increment the error counter with each junk command.
Available in Postfix version 2.1 and later:
<b><a href="postconf.5.html#smtpd_recipient_overshoot_limit">smtpd_recipient_overshoot_limit</a> (1000)</b>
The number of recipients that a remote SMTP client can send in
The number of recipients that a remote SMTP client can send in
excess of the limit specified with $<a href="postconf.5.html#smtpd_recipient_limit">smtpd_recipient_limit</a>,
before the Postfix SMTP server increments the per-session error
before the Postfix SMTP server increments the per-session error
count for each excess recipient.
<b>ACCESS POLICY DELEGATION CONTROLS</b>
As of version 2.1, Postfix can be configured to delegate access policy
decisions to an external server that runs outside Postfix. See the
As of version 2.1, Postfix can be configured to delegate access policy
decisions to an external server that runs outside Postfix. See the
file <a href="SMTPD_POLICY_README.html">SMTPD_POLICY_README</a> for more information.
<b><a href="postconf.5.html#smtpd_policy_service_max_idle">smtpd_policy_service_max_idle</a> (300s)</b>
The time after which an idle SMTPD policy service connection is
The time after which an idle SMTPD policy service connection is
closed.
<b><a href="postconf.5.html#smtpd_policy_service_max_ttl">smtpd_policy_service_max_ttl</a> (1000s)</b>
The time after which an active SMTPD policy service connection
The time after which an active SMTPD policy service connection
is closed.
<b><a href="postconf.5.html#smtpd_policy_service_timeout">smtpd_policy_service_timeout</a> (100s)</b>
The time limit for connecting to, writing to, or receiving from
The time limit for connecting to, writing to, or receiving from
a delegated SMTPD policy server.
Available in Postfix version 3.0 and later:
@ -976,81 +987,81 @@ SMTPD(8) SMTPD(8)
The default action when an SMTPD policy service request fails.
<b><a href="postconf.5.html#smtpd_policy_service_request_limit">smtpd_policy_service_request_limit</a> (0)</b>
The maximal number of requests per SMTPD policy service connec-
The maximal number of requests per SMTPD policy service connec-
tion, or zero (no limit).
<b><a href="postconf.5.html#smtpd_policy_service_try_limit">smtpd_policy_service_try_limit</a> (2)</b>
The maximal number of attempts to send an SMTPD policy service
The maximal number of attempts to send an SMTPD policy service
request before giving up.
<b><a href="postconf.5.html#smtpd_policy_service_retry_delay">smtpd_policy_service_retry_delay</a> (1s)</b>
The delay between attempts to resend a failed SMTPD policy ser-
The delay between attempts to resend a failed SMTPD policy ser-
vice request.
Available in Postfix version 3.1 and later:
<b><a href="postconf.5.html#smtpd_policy_service_policy_context">smtpd_policy_service_policy_context</a> (empty)</b>
Optional information that the Postfix SMTP server specifies in
the "policy_context" attribute of a policy service request
(originally, to share the same service endpoint among multiple
Optional information that the Postfix SMTP server specifies in
the "policy_context" attribute of a policy service request
(originally, to share the same service endpoint among multiple
<a href="postconf.5.html#check_policy_service">check_policy_service</a> clients).
<b>ACCESS CONTROLS</b>
The <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a> document gives an introduction to all the SMTP
The <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a> document gives an introduction to all the SMTP
server access control features.
<b><a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> (yes)</b>
Wait until the RCPT TO command before evaluating
Wait until the RCPT TO command before evaluating
$<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>, $<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> and
$<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>, or wait until the ETRN command
before evaluating $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and
before evaluating $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and
$<a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a>.
<b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> (see 'postconf -d' output)</b>
A list of Postfix features where the pattern "example.com" also
matches subdomains of example.com, instead of requiring an
A list of Postfix features where the pattern "example.com" also
matches subdomains of example.com, instead of requiring an
explicit ".example.com" pattern.
<b><a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> (empty)</b>
Optional restrictions that the Postfix SMTP server applies in
Optional restrictions that the Postfix SMTP server applies in
the context of a client connection request.
<b><a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> (no)</b>
Require that a remote SMTP client introduces itself with the
HELO or EHLO command before sending the MAIL command or other
Require that a remote SMTP client introduces itself with the
HELO or EHLO command before sending the MAIL command or other
commands that require EHLO negotiation.
<b><a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> (empty)</b>
Optional restrictions that the Postfix SMTP server applies in
Optional restrictions that the Postfix SMTP server applies in
the context of a client HELO command.
<b><a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> (empty)</b>
Optional restrictions that the Postfix SMTP server applies in
Optional restrictions that the Postfix SMTP server applies in
the context of a client MAIL FROM command.
<b><a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a> (see 'postconf -d' output)</b>
Optional restrictions that the Postfix SMTP server applies in
the context of a client RCPT TO command, after
Optional restrictions that the Postfix SMTP server applies in
the context of a client RCPT TO command, after
<a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a>.
<b><a href="postconf.5.html#smtpd_etrn_restrictions">smtpd_etrn_restrictions</a> (empty)</b>
Optional restrictions that the Postfix SMTP server applies in
Optional restrictions that the Postfix SMTP server applies in
the context of a client ETRN command.
<b><a href="postconf.5.html#allow_untrusted_routing">allow_untrusted_routing</a> (no)</b>
Forward mail with sender-specified routing
(user[@%!]remote[@%!]site) from untrusted clients to destina-
Forward mail with sender-specified routing
(user[@%!]remote[@%!]site) from untrusted clients to destina-
tions matching $<a href="postconf.5.html#relay_domains">relay_domains</a>.
<b><a href="postconf.5.html#smtpd_restriction_classes">smtpd_restriction_classes</a> (empty)</b>
User-defined aliases for groups of access restrictions.
<b><a href="postconf.5.html#smtpd_null_access_lookup_key">smtpd_null_access_lookup_key</a> (</b>&lt;&gt;<b>)</b>
The lookup key to be used in SMTP <a href="access.5.html"><b>access</b>(5)</a> tables instead of
The lookup key to be used in SMTP <a href="access.5.html"><b>access</b>(5)</a> tables instead of
the null sender address.
<b><a href="postconf.5.html#permit_mx_backup_networks">permit_mx_backup_networks</a> (empty)</b>
Restrict the use of the <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> SMTP access feature to
Restrict the use of the <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a> SMTP access feature to
only domains whose primary MX hosts match the listed networks.
Available in Postfix version 2.0 and later:
@ -1060,19 +1071,19 @@ SMTPD(8) SMTPD(8)
applies in the context of the SMTP DATA command.
<b><a href="postconf.5.html#smtpd_expansion_filter">smtpd_expansion_filter</a> (see 'postconf -d' output)</b>
What characters are allowed in $name expansions of RBL reply
What characters are allowed in $name expansions of RBL reply
templates.
Available in Postfix version 2.1 and later:
<b><a href="postconf.5.html#smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a> (no)</b>
Request that the Postfix SMTP server rejects mail from unknown
sender addresses, even when no explicit <a href="postconf.5.html#reject_unlisted_sender">reject_unlisted_sender</a>
Request that the Postfix SMTP server rejects mail from unknown
sender addresses, even when no explicit <a href="postconf.5.html#reject_unlisted_sender">reject_unlisted_sender</a>
access restriction is specified.
<b><a href="postconf.5.html#smtpd_reject_unlisted_recipient">smtpd_reject_unlisted_recipient</a> (yes)</b>
Request that the Postfix SMTP server rejects mail for unknown
recipient addresses, even when no explicit
Request that the Postfix SMTP server rejects mail for unknown
recipient addresses, even when no explicit
<a href="postconf.5.html#reject_unlisted_recipient">reject_unlisted_recipient</a> access restriction is specified.
Available in Postfix version 2.2 and later:
@ -1086,17 +1097,17 @@ SMTPD(8) SMTPD(8)
<b><a href="postconf.5.html#smtpd_relay_restrictions">smtpd_relay_restrictions</a> (<a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>, <a href="postconf.5.html#permit_sasl_authenticated">permit_sasl_authenticated</a>,</b>
<b><a href="postconf.5.html#defer_unauth_destination">defer_unauth_destination</a>)</b>
Access restrictions for mail relay control that the Postfix SMTP
server applies in the context of the RCPT TO command, before
server applies in the context of the RCPT TO command, before
<a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>.
<b>SENDER AND RECIPIENT ADDRESS VERIFICATION CONTROLS</b>
Postfix version 2.1 introduces sender and recipient address verifica-
Postfix version 2.1 introduces sender and recipient address verifica-
tion. This feature is implemented by sending probe email messages that
are not actually delivered. This feature is requested via the
<a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> and <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> access
restrictions. The status of verification probes is maintained by the
<a href="verify.8.html"><b>verify</b>(8)</a> server. See the file <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a> for infor-
mation about how to configure and operate the Postfix sender/recipient
<a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> and <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> access
restrictions. The status of verification probes is maintained by the
<a href="verify.8.html"><b>verify</b>(8)</a> server. See the file <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a> for infor-
mation about how to configure and operate the Postfix sender/recipient
address verification service.
<b><a href="postconf.5.html#address_verify_poll_count">address_verify_poll_count</a> (normal: 3, overload: 1)</b>
@ -1108,7 +1119,7 @@ SMTPD(8) SMTPD(8)
fication request in progress.
<b><a href="postconf.5.html#address_verify_sender">address_verify_sender</a> ($<a href="postconf.5.html#double_bounce_sender">double_bounce_sender</a>)</b>
The sender address to use in address verification probes; prior
The sender address to use in address verification probes; prior
to Postfix 2.5 the default was "postmaster".
<b><a href="postconf.5.html#unverified_sender_reject_code">unverified_sender_reject_code</a> (450)</b>
@ -1116,18 +1127,18 @@ SMTPD(8) SMTPD(8)
address is rejected by the <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> restriction.
<b><a href="postconf.5.html#unverified_recipient_reject_code">unverified_recipient_reject_code</a> (450)</b>
The numerical Postfix SMTP server response when a recipient
address is rejected by the <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> restric-
The numerical Postfix SMTP server response when a recipient
address is rejected by the <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a> restric-
tion.
Available in Postfix version 2.6 and later:
<b><a href="postconf.5.html#unverified_sender_defer_code">unverified_sender_defer_code</a> (450)</b>
The numerical Postfix SMTP server response code when a sender
The numerical Postfix SMTP server response code when a sender
address probe fails due to a temporary error condition.
<b><a href="postconf.5.html#unverified_recipient_defer_code">unverified_recipient_defer_code</a> (450)</b>
The numerical Postfix SMTP server response when a recipient
The numerical Postfix SMTP server response when a recipient
address probe fails due to a temporary error condition.
<b><a href="postconf.5.html#unverified_sender_reject_reason">unverified_sender_reject_reason</a> (empty)</b>
@ -1139,17 +1150,17 @@ SMTPD(8) SMTPD(8)
<a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>.
<b><a href="postconf.5.html#unverified_sender_tempfail_action">unverified_sender_tempfail_action</a> ($<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b>
The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a>
The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a>
fails due to a temporary error condition.
<b><a href="postconf.5.html#unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a> ($<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b>
The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipi</a>-
The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipi</a>-
<a href="postconf.5.html#reject_unverified_recipient">ent</a> fails due to a temporary error condition.
Available with Postfix 2.9 and later:
<b><a href="postconf.5.html#address_verify_sender_ttl">address_verify_sender_ttl</a> (0s)</b>
The time between changes in the time-dependent portion of
The time between changes in the time-dependent portion of
address verification probe sender addresses.
<b>ACCESS CONTROL RESPONSES</b>
@ -1161,36 +1172,36 @@ SMTPD(8) SMTPD(8)
map "reject" action.
<b><a href="postconf.5.html#defer_code">defer_code</a> (450)</b>
The numerical Postfix SMTP server response code when a remote
The numerical Postfix SMTP server response code when a remote
SMTP client request is rejected by the "defer" restriction.
<b><a href="postconf.5.html#invalid_hostname_reject_code">invalid_hostname_reject_code</a> (501)</b>
The numerical Postfix SMTP server response code when the client
HELO or EHLO command parameter is rejected by the
The numerical Postfix SMTP server response code when the client
HELO or EHLO command parameter is rejected by the
<a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a> restriction.
<b><a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> (554)</b>
The numerical Postfix SMTP server response code when a remote
SMTP client request is blocked by the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a>,
The numerical Postfix SMTP server response code when a remote
SMTP client request is blocked by the <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a>,
<a href="postconf.5.html#reject_rhsbl_client">reject_rhsbl_client</a>, <a href="postconf.5.html#reject_rhsbl_reverse_client">reject_rhsbl_reverse_client</a>,
<a href="postconf.5.html#reject_rhsbl_sender">reject_rhsbl_sender</a> or <a href="postconf.5.html#reject_rhsbl_recipient">reject_rhsbl_recipient</a> restriction.
<b><a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> (504)</b>
The numerical Postfix SMTP server reply code when a client
request is rejected by the <a href="postconf.5.html#reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a>,
The numerical Postfix SMTP server reply code when a client
request is rejected by the <a href="postconf.5.html#reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a>,
<a href="postconf.5.html#reject_non_fqdn_sender">reject_non_fqdn_sender</a> or <a href="postconf.5.html#reject_non_fqdn_recipient">reject_non_fqdn_recipient</a> restriction.
<b><a href="postconf.5.html#plaintext_reject_code">plaintext_reject_code</a> (450)</b>
The numerical Postfix SMTP server response code when a request
The numerical Postfix SMTP server response code when a request
is rejected by the <b><a href="postconf.5.html#reject_plaintext_session">reject_plaintext_session</a></b> restriction.
<b><a href="postconf.5.html#reject_code">reject_code</a> (554)</b>
The numerical Postfix SMTP server response code when a remote
The numerical Postfix SMTP server response code when a remote
SMTP client request is rejected by the "reject" restriction.
<b><a href="postconf.5.html#relay_domains_reject_code">relay_domains_reject_code</a> (554)</b>
The numerical Postfix SMTP server response code when a client
request is rejected by the <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> recipient
The numerical Postfix SMTP server response code when a client
request is rejected by the <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> recipient
restriction.
<b><a href="postconf.5.html#unknown_address_reject_code">unknown_address_reject_code</a> (450)</b>
@ -1198,24 +1209,24 @@ SMTPD(8) SMTPD(8)
a sender or recipient address because its domain is unknown.
<b><a href="postconf.5.html#unknown_client_reject_code">unknown_client_reject_code</a> (450)</b>
The numerical Postfix SMTP server response code when a client
without valid address &lt;=&gt; name mapping is rejected by the
The numerical Postfix SMTP server response code when a client
without valid address &lt;=&gt; name mapping is rejected by the
<a href="postconf.5.html#reject_unknown_client_hostname">reject_unknown_client_hostname</a> restriction.
<b><a href="postconf.5.html#unknown_hostname_reject_code">unknown_hostname_reject_code</a> (450)</b>
The numerical Postfix SMTP server response code when the host-
name specified with the HELO or EHLO command is rejected by the
The numerical Postfix SMTP server response code when the host-
name specified with the HELO or EHLO command is rejected by the
<a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> restriction.
Available in Postfix version 2.0 and later:
<b><a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> (see 'postconf -d' output)</b>
The default Postfix SMTP server response template for a request
The default Postfix SMTP server response template for a request
that is rejected by an RBL-based restriction.
<b><a href="postconf.5.html#multi_recipient_bounce_reject_code">multi_recipient_bounce_reject_code</a> (550)</b>
The numerical Postfix SMTP server response code when a remote
SMTP client request is blocked by the <a href="postconf.5.html#reject_multi_recipient_bounce">reject_multi_recipi</a>-
The numerical Postfix SMTP server response code when a remote
SMTP client request is blocked by the <a href="postconf.5.html#reject_multi_recipient_bounce">reject_multi_recipi</a>-
<a href="postconf.5.html#reject_multi_recipient_bounce">ent_bounce</a> restriction.
<b><a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> (empty)</b>
@ -1225,52 +1236,52 @@ SMTPD(8) SMTPD(8)
<b><a href="postconf.5.html#access_map_defer_code">access_map_defer_code</a> (450)</b>
The numerical Postfix SMTP server response code for an <a href="access.5.html"><b>access</b>(5)</a>
map "defer" action, including "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" or
map "defer" action, including "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" or
"<a href="postconf.5.html#defer_if_reject">defer_if_reject</a>".
<b><a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a> (<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>)</b>
The Postfix SMTP server's action when a reject-type restriction
The Postfix SMTP server's action when a reject-type restriction
fails due to a temporary error condition.
<b><a href="postconf.5.html#unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a> ($<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b>
The Postfix SMTP server's action when <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_host</a>-
The Postfix SMTP server's action when <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_host</a>-
<a href="postconf.5.html#reject_unknown_helo_hostname">name</a> fails due to a temporary error condition.
<b><a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a> ($<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b>
The Postfix SMTP server's action when
<a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a> or <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a>
The Postfix SMTP server's action when
<a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a> or <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a>
fail due to a temporary error condition.
<b>MISCELLANEOUS CONTROLS</b>
<b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
The default location of the Postfix <a href="postconf.5.html">main.cf</a> and <a href="master.5.html">master.cf</a> con-
The default location of the Postfix <a href="postconf.5.html">main.cf</a> and <a href="master.5.html">master.cf</a> con-
figuration files.
<b><a href="postconf.5.html#daemon_timeout">daemon_timeout</a> (18000s)</b>
How much time a Postfix daemon process may take to handle a
How much time a Postfix daemon process may take to handle a
request before it is terminated by a built-in watchdog timer.
<b><a href="postconf.5.html#command_directory">command_directory</a> (see 'postconf -d' output)</b>
The location of all postfix administrative commands.
<b><a href="postconf.5.html#double_bounce_sender">double_bounce_sender</a> (double-bounce)</b>
The sender address of postmaster notifications that are gener-
The sender address of postmaster notifications that are gener-
ated by the mail system.
<b><a href="postconf.5.html#ipc_timeout">ipc_timeout</a> (3600s)</b>
The time limit for sending or receiving information over an
The time limit for sending or receiving information over an
internal communication channel.
<b><a href="postconf.5.html#mail_name">mail_name</a> (Postfix)</b>
The mail system name that is displayed in Received: headers, in
The mail system name that is displayed in Received: headers, in
the SMTP greeting banner, and in bounced mail.
<b><a href="postconf.5.html#mail_owner">mail_owner</a> (postfix)</b>
The UNIX system account that owns the Postfix queue and most
The UNIX system account that owns the Postfix queue and most
Postfix daemon processes.
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix daemon process
The maximum amount of time that an idle Postfix daemon process
waits for an incoming connection before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
@ -1281,11 +1292,11 @@ SMTPD(8) SMTPD(8)
The internet hostname of this mail system.
<b><a href="postconf.5.html#mynetworks">mynetworks</a> (see 'postconf -d' output)</b>
The list of "trusted" remote SMTP clients that have more privi-
The list of "trusted" remote SMTP clients that have more privi-
leges than "strangers".
<b><a href="postconf.5.html#myorigin">myorigin</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
The domain name that locally-posted mail appears to come from,
The domain name that locally-posted mail appears to come from,
and that locally posted mail is delivered to.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
@ -1298,25 +1309,25 @@ SMTPD(8) SMTPD(8)
The location of the Postfix top-level queue directory.
<b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> (empty)</b>
The set of characters that can separate a user name from its
extension (example: user+foo), or a .forward file name from its
The set of characters that can separate a user name from its
extension (example: user+foo), or a .forward file name from its
extension (example: .forward+foo).
<b><a href="postconf.5.html#smtpd_banner">smtpd_banner</a> ($<a href="postconf.5.html#myhostname">myhostname</a> ESMTP $<a href="postconf.5.html#mail_name">mail_name</a>)</b>
The text that follows the 220 status code in the SMTP greeting
The text that follows the 220 status code in the SMTP greeting
banner.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (see 'postconf -d' output)</b>
A prefix that is prepended to the process name in syslog
A prefix that is prepended to the process name in syslog
records, so that, for example, "smtpd" becomes "prefix/smtpd".
Available in Postfix version 2.2 and later:
<b><a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a> (CONNECT, GET, POST)</b>
List of commands that cause the Postfix SMTP server to immedi-
List of commands that cause the Postfix SMTP server to immedi-
ately terminate the session with a 221 code.
Available in Postfix version 2.5 and later:
@ -1333,7 +1344,7 @@ SMTPD(8) SMTPD(8)
Available in Postfix 3.4 and later:
<b><a href="postconf.5.html#smtpd_reject_footer_maps">smtpd_reject_footer_maps</a> (empty)</b>
Lookup tables, indexed by the complete Postfix SMTP server 4xx
Lookup tables, indexed by the complete Postfix SMTP server 4xx
or 5xx response, with reject footer templates.
<b>SEE ALSO</b>

View File

@ -10206,6 +10206,61 @@ The smtpd_expansion_filter value is not subject to Postfix configuration
parameter $name expansion.
.PP
This feature is available in Postfix 2.0 and later.
.SH smtpd_forbid_bare_newline (default: Postfix < 3.9: no)
Reply with "Error: bare <LF> received" and disconnect
when a remote SMTP client sends a line ending in <LF>, violating
the RFC 5321 requirement that lines must end in <CR><LF>.
This feature is disbled by default with Postfix < 3.9. Use
smtpd_forbid_bare_newline_exclusions to exclude non\-standard clients
such as netcat. Specify "smtpd_forbid_bare_newline = no" to disable
(not recommended for an Internet\-connected MTA).
.PP
See
https://www.postfix.org/smtp\-smuggling.html for details.
.PP
Example:
.sp
.in +4
.nf
.na
.ft C
# Disconnect remote SMTP clients that send bare newlines, but allow
# local clients with non\-standard SMTP implementations such as netcat,
# fax machines, or load balancer health checks.
#
smtpd_forbid_bare_newline = yes
smtpd_forbid_bare_newline_exclusions = $mynetworks
.fi
.ad
.ft R
.in -4
.PP
This feature is available in Postfix >= 3.9, 3.8.4, 3.7.9,
3.6.13, and 3.5.23.
.SH smtpd_forbid_bare_newline_exclusions (default: $mynetworks)
Exclude the specified clients from smtpd_forbid_bare_newline
enforcement. It uses the same syntax and parent\-domain matching
behavior as mynetworks.
.PP
Example:
.sp
.in +4
.nf
.na
.ft C
# Disconnect remote SMTP clients that send bare newlines, but allow
# local clients with non\-standard SMTP implementations such as netcat,
# fax machines, or load balancer health checks.
#
smtpd_forbid_bare_newline = yes
smtpd_forbid_bare_newline_exclusions = $mynetworks
.fi
.ad
.ft R
.in -4
.PP
This feature is available in Postfix >= 3.9, 3.8.4, 3.7.9,
3.6.13, and 3.5.23.
.SH smtpd_forbid_unauth_pipelining (default: Postfix >= 3.9: yes)
Disconnect remote SMTP clients that violate RFC 2920 (or 5321)
command pipelining constraints. The server replies with "554 5.5.0

View File

@ -809,6 +809,15 @@ Available in Postfix 3.9, 3.8.1, 3.7.6, 3.6.10, 3.5.20 and later:
.IP "\fBsmtpd_forbid_unauth_pipelining (Postfix >= 3.9: yes)\fR"
Disconnect remote SMTP clients that violate RFC 2920 (or 5321)
command pipelining constraints.
.PP
Available in Postfix 3.9, 3.8.4, 3.7.9, 3.6.13, 3.5.23 and later:
.IP "\fBsmtpd_forbid_bare_newline (Postfix < 3.9: no)\fR"
Reply with "Error: bare <LF> received" and disconnect
when a remote SMTP client sends a line ending in <LF>, violating
the RFC 5321 requirement that lines must end in <CR><LF>.
.IP "\fBsmtpd_forbid_bare_newline_exclusions ($mynetworks)\fR"
Exclude the specified clients from smtpd_forbid_bare_newline
enforcement.
.SH "TARPIT CONTROLS"
.na
.nf

View File

@ -548,6 +548,8 @@ while (<>) {
s;\bsmtpd_etrn_restrictions\b;<a href="postconf.5.html#smtpd_etrn_restrictions">$&</a>;g;
s;\bsmtpd_expansion_filter\b;<a href="postconf.5.html#smtpd_expansion_filter">$&</a>;g;
s;\bsmtpd_for[-</bB>]*\n*[ <bB>]*bidden_commands\b;<a href="postconf.5.html#smtpd_forbidden_commands">$&</a>;g;
s;\bsmtpd_for[-</bB>]*\n*[ <bB>]*bid_bare_newline\b;<a href="postconf.5.html#smtpd_forbid_bare_newline">$&</a>;g;
s;\bsmtpd_for[-</bB>]*\n*[ <bB>]*bid_bare_newline_exclusions\b;<a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">$&</a>;g;
s;\bsmtpd_for[-</bB>]*\n*[ <bB>]*bid_unauth_pipelining\b;<a href="postconf.5.html#smtpd_forbid_unauth_pipelining">$&</a>;g;
s;\bsmtpd_hard_error_limit\b;<a href="postconf.5.html#smtpd_hard_error_limit">$&</a>;g;
s;\bsmtpd_helo_required\b;<a href="postconf.5.html#smtpd_helo_required">$&</a>;g;

View File

@ -17863,6 +17863,57 @@ MinProtocol = TLSv1
<p> This feature is available in Postfix &ge; 3.9, 3.8.1, 3.7.6,
3.6.10, and 3.5.20. </p>
%PARAM smtpd_forbid_bare_newline Postfix &lt; 3.9: no
<p> Reply with "Error: bare &lt;LF&gt; received" and disconnect
when a remote SMTP client sends a line ending in &lt;LF&gt;, violating
the RFC 5321 requirement that lines must end in &lt;CR&gt;&lt;LF&gt;.
This feature is disbled by default with Postfix &lt; 3.9. Use
smtpd_forbid_bare_newline_exclusions to exclude non-standard clients
such as netcat. Specify "smtpd_forbid_bare_newline = no" to disable
(not recommended for an Internet-connected MTA). </p>
<p> See <a href="https://www.postfix.org/smtp-smuggling.html">
https://www.postfix.org/smtp-smuggling.html</a> for details.
<p> Example: </p>
<blockquote>
<pre>
# Disconnect remote SMTP clients that send bare newlines, but allow
# local clients with non-standard SMTP implementations such as netcat,
# fax machines, or load balancer health checks.
#
smtpd_forbid_bare_newline = yes
smtpd_forbid_bare_newline_exclusions = $mynetworks
</pre>
</blockquote>
<p> This feature is available in Postfix &ge; 3.9, 3.8.4, 3.7.9,
3.6.13, and 3.5.23. </p>
%PARAM smtpd_forbid_bare_newline_exclusions $mynetworks
<p> Exclude the specified clients from smtpd_forbid_bare_newline
enforcement. It uses the same syntax and parent-domain matching
behavior as mynetworks. </p>
<p> Example: </p>
<blockquote>
<pre>
# Disconnect remote SMTP clients that send bare newlines, but allow
# local clients with non-standard SMTP implementations such as netcat,
# fax machines, or load balancer health checks.
#
smtpd_forbid_bare_newline = yes
smtpd_forbid_bare_newline_exclusions = $mynetworks
</pre>
</blockquote>
<p> This feature is available in Postfix &ge; 3.9, 3.8.4, 3.7.9,
3.6.13, and 3.5.23. </p>
%PARAM smtpd_forbid_unauth_pipelining Postfix &ge; 3.9: yes
<p> Disconnect remote SMTP clients that violate RFC 2920 (or 5321)

View File

@ -4142,7 +4142,16 @@ extern char *var_smtp_dns_re_filter;
extern char *var_smtpd_dns_re_filter;
/*
* Share TLS sessions through tlproxy(8).
* Backwards compatibility.
*/
#define VAR_SMTPD_FORBID_BARE_LF "smtpd_forbid_bare_newline"
#define DEF_SMTPD_FORBID_BARE_LF 0
#define VAR_SMTPD_FORBID_BARE_LF_EXCL "smtpd_forbid_bare_newline_exclusions"
#define DEF_SMTPD_FORBID_BARE_LF_EXCL "$" VAR_MYNETWORKS
/*
* Share TLS sessions through tlsproxy(8).
*/
#define VAR_SMTP_TLS_CONN_REUSE "smtp_tls_connection_reuse"
#define DEF_SMTP_TLS_CONN_REUSE 0

View File

@ -20,8 +20,8 @@
* Patches change both the patchlevel and the release date. Snapshots have no
* patchlevel; they change the release date only.
*/
#define MAIL_RELEASE_DATE "20231101"
#define MAIL_VERSION_NUMBER "3.5.22"
#define MAIL_RELEASE_DATE "20231222"
#define MAIL_VERSION_NUMBER "3.5.23"
#ifdef SNAPSHOT
#define MAIL_VERSION_DATE "-" MAIL_RELEASE_DATE

View File

@ -50,6 +50,8 @@
/* VSTREAM *stream;
/* char *format;
/* va_list ap;
/*
/* int smtp_forbid_bare_lf;
/* AUXILIARY API
/* int smtp_get_noexcept(vp, stream, maxlen, flags)
/* VSTRING *vp;
@ -124,11 +126,16 @@
/* smtp_vprintf() is the machine underneath smtp_printf().
/*
/* smtp_get_noexcept() implements the subset of smtp_get()
/* without timeouts and without making long jumps. Instead,
/* without long jumps for timeout or EOF errors. Instead,
/* query the stream status with vstream_feof() etc.
/* This function will make a VSTREAM long jump (error code
/* SMTP_ERR_LF) when rejecting input with a bare newline byte.
/*
/* smtp_timeout_setup() is a backwards-compatibility interface
/* for programs that don't require per-record deadline support.
/*
/* smtp_forbid_bare_lf controls whether smtp_get_noexcept()
/* will reject input with a bare newline byte.
/* DIAGNOSTICS
/* .fi
/* .ad
@ -201,6 +208,8 @@
#include "smtp_stream.h"
int smtp_forbid_bare_lf;
/* smtp_timeout_reset - reset per-stream error flags, restart deadline timer */
static void smtp_timeout_reset(VSTREAM *stream)
@ -404,6 +413,9 @@ int smtp_get_noexcept(VSTRING *vp, VSTREAM *stream, ssize_t bound, int flags
*/
case '\n':
vstring_truncate(vp, VSTRING_LEN(vp) - 1);
if (smtp_forbid_bare_lf
&& (VSTRING_LEN(vp) == 0 || vstring_end(vp)[-1] != '\r'))
vstream_longjmp(stream, SMTP_ERR_LF);
while (VSTRING_LEN(vp) > 0 && vstring_end(vp)[-1] == '\r')
vstring_truncate(vp, VSTRING_LEN(vp) - 1);
VSTRING_TERMINATE(vp);

View File

@ -32,6 +32,7 @@
#define SMTP_ERR_QUIET 3 /* silent cleanup (application) */
#define SMTP_ERR_NONE 4 /* non-error case */
#define SMTP_ERR_DATA 5 /* application data error */
#define SMTP_ERR_LF 6 /* bare <LF> protocol error */
extern void smtp_stream_setup(VSTREAM *, int, int);
extern void PRINTFLIKE(2, 3) smtp_printf(VSTREAM *, const char *,...);
@ -43,6 +44,7 @@ extern void smtp_fputs(const char *, ssize_t len, VSTREAM *);
extern void smtp_fwrite(const char *, ssize_t len, VSTREAM *);
extern void smtp_fread_buf(VSTRING *, ssize_t len, VSTREAM *);
extern void smtp_fputc(int, VSTREAM *);
extern int smtp_forbid_bare_lf;
extern void smtp_vprintf(VSTREAM *, const char *, va_list);

View File

@ -763,6 +763,15 @@
/* .IP "\fBsmtpd_forbid_unauth_pipelining (Postfix >= 3.9: yes)\fR"
/* Disconnect remote SMTP clients that violate RFC 2920 (or 5321)
/* command pipelining constraints.
/* .PP
/* Available in Postfix 3.9, 3.8.4, 3.7.9, 3.6.13, 3.5.23 and later:
/* .IP "\fBsmtpd_forbid_bare_newline (Postfix < 3.9: no)\fR"
/* Reply with "Error: bare <LF> received" and disconnect
/* when a remote SMTP client sends a line ending in <LF>, violating
/* the RFC 5321 requirement that lines must end in <CR><LF>.
/* .IP "\fBsmtpd_forbid_bare_newline_exclusions ($mynetworks)\fR"
/* Exclude the specified clients from smtpd_forbid_bare_newline
/* enforcement.
/* TARPIT CONTROLS
/* .ad
/* .fi
@ -1468,6 +1477,10 @@ char *var_tlsproxy_service;
char *var_smtpd_uproxy_proto;
int var_smtpd_uproxy_tmout;
bool var_smtpd_forbid_bare_lf;
char *var_smtpd_forbid_bare_lf_excl;
static NAMADR_LIST *bare_lf_excl;
/*
* Silly little macros.
*/
@ -1542,6 +1555,7 @@ static void tls_reset(SMTPD_STATE *);
#define REASON_TIMEOUT "timeout"
#define REASON_LOST_CONNECTION "lost connection"
#define REASON_ERROR_LIMIT "too many errors"
#define REASON_BARE_LF "bare <LF> received"
#ifdef USE_TLS
@ -3968,6 +3982,7 @@ static int bdat_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
*/
done = 0;
do {
int payload_err;
/*
* Do not skip the smtp_fread_buf() call if read_len == 0. We still
@ -3981,6 +3996,10 @@ static int bdat_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
smtp_fread_buf(state->buffer, read_len, state->client);
state->bdat_get_stream = vstream_memreopen(
state->bdat_get_stream, state->buffer, O_RDONLY);
vstream_control(state->bdat_get_stream, CA_VSTREAM_CTL_EXCEPT,
CA_VSTREAM_CTL_END);
if ((payload_err = vstream_setjmp(state->bdat_get_stream)) != 0)
vstream_longjmp(state->client, payload_err);
/*
* Read lines from the fragment. The last line may continue in the
@ -4656,6 +4675,9 @@ static int xclient_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
*/
xclient_allowed =
namadr_list_match(xclient_hosts, state->name, state->addr);
smtp_forbid_bare_lf = SMTPD_STAND_ALONE((state)) == 0
&& var_smtpd_forbid_bare_lf
&& !namadr_list_match(bare_lf_excl, state->name, state->addr);
/* NOT: tls_reset() */
if (got_helo == 0)
helo_reset(state);
@ -5474,6 +5496,13 @@ static void smtpd_proto(SMTPD_STATE *state)
var_myhostname);
break;
case SMTP_ERR_LF:
state->reason = REASON_BARE_LF;
if (vstream_setjmp(state->client) == 0)
smtpd_chat_reply(state, "521 5.5.2 %s Error: bare <LF> received",
var_myhostname);
break;
case 0:
/*
@ -6032,6 +6061,13 @@ static void smtpd_service(VSTREAM *stream, char *service, char **argv)
xforward_allowed = SMTPD_STAND_ALONE((&state)) == 0 &&
namadr_list_match(xforward_hosts, state.name, state.addr);
/*
* Enforce strict SMTP line endings, with compatibility exclusions.
*/
smtp_forbid_bare_lf = SMTPD_STAND_ALONE((&state)) == 0
&& var_smtpd_forbid_bare_lf
&& !namadr_list_match(bare_lf_excl, state.name, state.addr);
/*
* See if we need to turn on verbose logging for this client.
*/
@ -6093,6 +6129,10 @@ static void pre_jail_init(char *unused_name, char **unused_argv)
hogger_list = namadr_list_init(VAR_SMTPD_HOGGERS, MATCH_FLAG_RETURN
| match_parent_style(VAR_SMTPD_HOGGERS),
var_smtpd_hoggers);
bare_lf_excl = namadr_list_init(VAR_SMTPD_FORBID_BARE_LF_EXCL,
MATCH_FLAG_RETURN
| match_parent_style(VAR_MYNETWORKS),
var_smtpd_forbid_bare_lf_excl);
/*
* Open maps before dropping privileges so we can read passwords etc.
@ -6451,6 +6491,7 @@ int main(int argc, char **argv)
VAR_SMTPD_DELAY_OPEN, DEF_SMTPD_DELAY_OPEN, &var_smtpd_delay_open,
VAR_SMTPD_CLIENT_PORT_LOG, DEF_SMTPD_CLIENT_PORT_LOG, &var_smtpd_client_port_log,
VAR_SMTPD_FORBID_UNAUTH_PIPE, DEF_SMTPD_FORBID_UNAUTH_PIPE, &var_smtpd_forbid_unauth_pipe,
VAR_SMTPD_FORBID_BARE_LF, DEF_SMTPD_FORBID_BARE_LF, &var_smtpd_forbid_bare_lf,
0,
};
static const CONFIG_NBOOL_TABLE nbool_table[] = {
@ -6564,6 +6605,7 @@ int main(int argc, char **argv)
VAR_SMTPD_POLICY_CONTEXT, DEF_SMTPD_POLICY_CONTEXT, &var_smtpd_policy_context, 0, 0,
VAR_SMTPD_DNS_RE_FILTER, DEF_SMTPD_DNS_RE_FILTER, &var_smtpd_dns_re_filter, 0, 0,
VAR_SMTPD_REJ_FTR_MAPS, DEF_SMTPD_REJ_FTR_MAPS, &var_smtpd_rej_ftr_maps, 0, 0,
VAR_SMTPD_FORBID_BARE_LF_EXCL, DEF_SMTPD_FORBID_BARE_LF_EXCL, &var_smtpd_forbid_bare_lf_excl, 0, 0,
0,
};
static const CONFIG_RAW_TABLE raw_table[] = {