Bitrot: Berkeley DB 18 is like Berkeley DB 6. Yasuhiro
Kimura. File: util/dict_db.c.
+
+20240109
+
+ Security (outbound SMTP smuggling): with the default setting
+ "cleanup_replace_stray_cr_lf = yes" Postfix will replace
+ stray <CR> or <LF> characters in message content with a
+ space character. This prevents Postfix from enabling
+ outbound (remote) SMTP smuggling, and it also makes evaluation
+ of Postfix-added DKIM etc. signatures independent from how
+ a remote mail server handles stray <CR> or <LF> characters.
+ Files: global/mail_params.h, cleanup/cleanup.c,
+ cleanup/cleanup_message.c, mantools/postlink, proto/postconf.proto.
+
+20240112
+
+ Security (inbound SMTP smuggling): with "smtpd_forbid_bare_newline
+ = normalize" (default "no" for Postfix < 3.9), the Postfix
+ SMTP server requires the standard End-of-DATA sequence
+ <CR><LF>.<CR><LF>, and otherwise allows command or message
+ content lines ending in the non-standard <LF>, processing
+ them as if the client sent the standard <CR><LF>.
+
+ The alternative setting, "smtpd_forbid_bare_newline = reject"
+ will reject any command or message that contains a bare
+ <LF>, and is more likely to cause problems with legitimate
+ clients.
+
+ 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, smtpd/smtpd_check.[hc].
If you upgrade from Postfix 3.1 or earlier, read RELEASE_NOTES-3.2
before proceeding.
+Incompatibility with Postfix 3.8.5, 3.7.10, 3.6.14, and 3.5.24
+==============================================================
+
+Improvements for outbound SMTP smuggling defense:
+
+- With "cleanup_replace_stray_cr_lf = yes" (the default), the cleanup
+ daemon replaces each stray <CR> or <LF> character in message
+ content with a space character. The replacement happens before
+ any other content management (header/body_checks, Milters, etc).
+
+ This prevents outbound SMTP smuggling, where an attacker uses
+ Postfix to send email containing a non-standard End-of-DATA
+ sequence, to exploit inbound SMTP smuggling at a vulnerable remote
+ SMTP server.
+
+ This also improves the remote evaluation of Postfix-added DKIM
+ and other signatures, as the evaluation result will not depend
+ on how a remote email server handles stray <CR> or <LF> characters.
+
+This feature applies to all email that Postfix locally or remotely
+sends out. It is not allowlisted based on client identity.
+
+Major changes with Postfix 3.8.5, 3.7.10, 3.6.14, and 3.5.24
+============================================================
+
+Improvements for inbound SMTP smuggling defense:
+
+- Better compatibility: the recommended setting "smtpd_forbid_bare_newline
+ = normalize" requires the standard End-of-DATA sequence
+ <CR><LF>.<CR><LF>, but allows bare newlines from SMTP clients,
+ maintaining more compatibility with existing infrastructure.
+
+- Improved logging for rejected input (it now includes queue ID,
+ helo, mail, and rcpt, if available).
+
+- The setting "smtpd_forbid_bare_newline = reject" requires
+ that input lines end in <CR><LF>, requires the standard End-of-DATA
+ sequence <CR><LF>.<CR><LF>, and rejects a command or message that
+ contains a bare newline. To disconnect the client, specify
+ "smtpd_forbid_bare_newline_reject_code = 521".
+
+- The Postfix SMTP server no longer strips extra <CR> as in
+ <CR><LF>.<CR><CR><LF>, to silence false alarms from test tools
+ that send attack sequences that real mail servers cannot send.
+ Details at https://www.postfix.org/false-smuggling-claims.html
+
+- The old setting "yes" has become an alias for "normalize".
+
+- The old setting "no" has not changed, and allows SMTP smuggling.
+
+The recommended settings are now:
+
+ # Require the standard End-of-DATA sequence <CR><LF>.<CR><LF>.
+ # Otherwise, allow bare <LF> and process it as if the client sent
+ # <CR><LF>.
+ #
+ # This maintains compatibility with many legitimate SMTP client
+ # applications that send a mix of standard and non-standard line
+ # endings, but will fail to receive email from client implementations
+ # that do not terminate DATA content with the standard End-of-DATA
+ # sequence <CR><LF>.<CR><LF>.
+ #
+ # Such clients can be allowlisted with smtpd_forbid_bare_newline_exclusions.
+ # The example below allowlists SMTP clients in trusted networks.
+ #
+ smtpd_forbid_bare_newline = normalize
+ smtpd_forbid_bare_newline_exclusions = $mynetworks
+
+Alternative settings:
+
+ # Reject input lines that contain <LF> and log a "bare <LF> received"
+ # error. Require that input lines end in <CR><LF>, and require the
+ # standard End-of-DATA sequence <CR><LF>.<CR><LF>.
+ #
+ # This will reject email from SMTP clients that send any non-standard
+ # line endings such as web applications, netcat, or load balancer
+ # health checks.
+ #
+ # Such clients can be allowlisted with smtpd_forbid_bare_newline_exclusions.
+ # The example below allowlists SMTP clients in trusted networks.
+ #
+ smtpd_forbid_bare_newline = reject
+ smtpd_forbid_bare_newline_exclusions = $mynetworks
+
Runtime detection of DNSSEC support
-----------------------------------
The set of characters that Postfix will remove from message con-
tent.
+ Available in Postfix version 3.9, 3.8.5, 3.7.10, 3.6.14, 3.5.24, and
+ later:
+
+ <b><a href="postconf.5.html#cleanup_replace_stray_cr_lf">cleanup_replace_stray_cr_lf</a> (yes)</b>
+ Replace each stray <CR> or <LF> character in message content
+ with a space character, to prevent outbound SMTP smuggling, and
+ to make the evaluation of Postfix-added DKIM or other signatures
+ independent from how a remote mail server handles such charac-
+ ters.
+
<b>BEFORE QUEUE MILTER CONTROLS</b>
As of version 2.3, Postfix supports the Sendmail version 8 Milter (mail
filter) protocol. When mail is not received via the <a href="smtpd.8.html">smtpd(8)</a> server,
</pre>
+</DD>
+
+<DT><b><a name="cleanup_replace_stray_cr_lf">cleanup_replace_stray_cr_lf</a>
+(default: yes)</b></DT><DD>
+
+<p> Replace each stray <CR> or <LF> character in message
+content with a space character, to prevent outbound SMTP smuggling,
+and to make the evaluation of Postfix-added DKIM or other signatures
+independent from how a remote mail server handles such characters.
+</p>
+
+<p> SMTP does not allow such characters unless they are part of a
+<CR><LF> sequence, and different mail systems handle
+such stray characters in an implementation-dependent manner. Stray
+<CR> or <LF> characters could be used for outbound
+SMTP smuggling, where an attacker uses a Postfix server to send
+message content with a non-standard End-of-DATA sequence that
+triggers inbound SMTP smuggling at a remote SMTP server.</p>
+
+<p> The replacement happens before all other content management,
+and before Postfix may add a DKIM etc. signature; if the signature
+were created first, the replacement could invalidate the signature.
+</p>
+
+<p> In addition to preventing SMTP smuggling, replacing stray
+<CR> or <LF> characters ensures that the result of
+signature validation by later mail system will not depend on how
+that mail system handles those stray characters in an
+implementation-dependent manner. </p>
+
+<p> This feature is available in Postfix ≥ 3.9, 3.8.5, 3.7.10,
+3.6.14, and 3.5.24. </p>
+
+
</DD>
<DT><b><a name="cleanup_service_name">cleanup_service_name</a>
</p>
+</DD>
+
+<DT><b><a name="smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a>
+(default: Postfix < 3.9: no)</b></DT><DD>
+
+<p> Reject or restrict input lines from an SMTP client that end in
+<LF> instead of the standard <CR><LF>. Such line
+endings are commonly allowed with UNIX-based SMTP servers, but they
+violate <a href="http://tools.ietf.org/html/rfc5321">RFC 5321</a>, and allowing such line endings can make a server
+vulnerable to <a href="https://www.postfix.org/smtp-smuggling.html">
+SMTP smuggling</a>. </p>
+
+<p> Specify one of the following values (case does not matter): </p>
+
+<dl compact>
+
+<dt> <b>normalize</b></dt> <dd> Require the standard
+End-of-DATA sequence <CR><LF>.<CR><LF>.
+Otherwise, allow command or message content lines ending in the
+non-standard <LF>, and process them as if the client sent the
+standard <CR><LF>. <br> <br> This maintains compatibility
+with many legitimate SMTP client applications that send a mix of
+standard and non-standard line endings, but will fail to receive
+email from client implementations that do not terminate DATA content
+with the standard End-of-DATA sequence
+<CR><LF>.<CR><LF>. <br> <br> Such clients
+can be excluded with <a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a>. </dd>
+
+<dt> <b>yes</b> </dt> <dd> Compatibility alias for <b>normalize</b>. </dd>
+
+<dt> <b>reject</b> </dt> <dd> Require the standard End-of-DATA
+sequence <CR><LF>.<CR><LF>. Reject a command
+or message content when a line contains bare <LF>, log a "bare
+<LF> received" error, and reply with the SMTP status code in
+$<a href="postconf.5.html#smtpd_forbid_bare_newline_reject_code">smtpd_forbid_bare_newline_reject_code</a>. <br> <br> This will reject
+email from SMTP clients that send any non-standard line endings
+such as web applications, netcat, or load balancer health checks.
+<br> <br> Such clients can be
+excluded with <a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a>. </dd>
+
+<dt> <b>no</b> (default)</dt> <dd> Do not require the standard
+End-of-DATA
+sequence <CR><LF>.<CR><LF>. Always process
+a bare <LF> as if the client sent <CR><LF>. This
+option is fully backwards compatible, but is not recommended for
+an Internet-facing SMTP server, because it is vulnerable to <a
+href="https://www.postfix.org/smtp-smuggling.html"> SMTP smuggling</a>.
+</dd>
+
+</dl>
+
+<p> Recommended settings: </p>
+
+<blockquote>
+<pre>
+# Require the standard End-of-DATA sequence <CR><LF>.<CR><LF>.
+# Otherwise, allow bare <LF> and process it as if the client sent
+# <CR><LF>.
+#
+# This maintains compatibility with many legitimate SMTP client
+# applications that send a mix of standard and non-standard line
+# endings, but will fail to receive email from client implementations
+# that do not terminate DATA content with the standard End-of-DATA
+# sequence <CR><LF>.<CR><LF>.
+#
+# Such clients can be allowlisted with <a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a>.
+# The example below allowlists SMTP clients in trusted networks.
+#
+<a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> = normalize
+<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> Alternative: </p>
+
+<blockquote>
+<pre>
+# Reject input lines that contain <LF> and log a "bare <LF> received"
+# error. Require that input lines end in <CR><LF>, and require the
+# standard End-of-DATA sequence <CR><LF>.<CR><LF>.
+#
+# This will reject email from SMTP clients that send any non-standard
+# line endings such as web applications, netcat, or load balancer
+# health checks.
+#
+# Such clients can be allowlisted with <a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a>.
+# The example below allowlists SMTP clients in trusted networks.
+#
+<a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> = reject
+<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 with settings <b>yes</b> and <b>no</b> is available
+in Postfix 3.8.4, 3.7.9, 3.6.13, and 3.5.23. Additionally, the
+settings <b>reject</b>, and <b>normalize</b> are available with
+Postfix ≥ 3.9, 3.8.5, 3.7.10, 3.6.14, and 3.5.24. </p>
+
+
+</DD>
+
+<DT><b><a name="smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a>
+(default: $<a href="postconf.5.html#mynetworks">mynetworks</a>)</b></DT><DD>
+
+<p> Exclude the specified clients from <a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a>
+enforcement. This setting uses the same syntax and parent-domain
+matching behavior as <a href="postconf.5.html#mynetworks">mynetworks</a>. </p>
+
+<p> This feature is available in Postfix ≥ 3.9, 3.8.4, 3.7.9,
+3.6.13, and 3.5.23. </p>
+
+
+</DD>
+
+<DT><b><a name="smtpd_forbid_bare_newline_reject_code">smtpd_forbid_bare_newline_reject_code</a>
+(default: 550)</b></DT><DD>
+
+<p>
+The numerical Postfix SMTP server response code when rejecting a
+request with "<a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> = reject".
+Specify a 5XX status code (521 to disconnect).
+</p>
+
+<p> This feature is available in Postfix ≥ 3.9, 3.8.5, 3.7.10,
+3.6.14, and 3.5.24. </p>
+
+
</DD>
<DT><b><a name="smtpd_forbidden_commands">smtpd_forbidden_commands</a>
to send to this service per time unit, regardless of whether or
not Postfix actually accepts those commands.
+ Available in Postfix 3.9, 3.8.4, 3.7.9, 3.6.13, 3.5.23 and later:
+
+ <b><a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> (Postfix</b> < <b>3.9: no)</b>
+ Reject or restrict input lines from an SMTP client that end in
+ <LF> instead of the standard <CR><LF>.
+
+ <b><a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">smtpd_forbid_bare_newline_exclusions</a> ($<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.
+
+ Available in Postfix 3.9, 3.8.5, 3.7.10, 3.6.14, 3.5.24 and later:
+
+ <b><a href="postconf.5.html#smtpd_forbid_bare_newline_reject_code">smtpd_forbid_bare_newline_reject_code</a> (550)</b>
+ The numerical Postfix SMTP server response code when rejecting a
+ request with "<a href="postconf.5.html#smtpd_forbid_bare_newline">smtpd_forbid_bare_newline</a> = reject".
+
<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
.fi
.ad
.ft R
+.SH cleanup_replace_stray_cr_lf (default: yes)
+Replace each stray <CR> or <LF> character in message
+content with a space character, to prevent outbound SMTP smuggling,
+and to make the evaluation of Postfix\-added DKIM or other signatures
+independent from how a remote mail server handles such characters.
+.PP
+SMTP does not allow such characters unless they are part of a
+<CR><LF> sequence, and different mail systems handle
+such stray characters in an implementation\-dependent manner. Stray
+<CR> or <LF> characters could be used for outbound
+SMTP smuggling, where an attacker uses a Postfix server to send
+message content with a non\-standard End\-of\-DATA sequence that
+triggers inbound SMTP smuggling at a remote SMTP server.
+.PP
+The replacement happens before all other content management,
+and before Postfix may add a DKIM etc. signature; if the signature
+were created first, the replacement could invalidate the signature.
+.PP
+In addition to preventing SMTP smuggling, replacing stray
+<CR> or <LF> characters ensures that the result of
+signature validation by later mail system will not depend on how
+that mail system handles those stray characters in an
+implementation\-dependent manner.
+.PP
+This feature is available in Postfix >= 3.9, 3.8.5, 3.7.10,
+3.6.14, and 3.5.24.
.SH cleanup_service_name (default: cleanup)
The name of the \fBcleanup\fR(8) service. This service rewrites addresses
into the standard form, and performs \fBcanonical\fR(5) address mapping
This parameter is not subjected to $parameter expansion.
.PP
This feature is available in Postfix 2.0 and later.
+.SH smtpd_forbid_bare_newline (default: Postfix < 3.9: no)
+Reject or restrict input lines from an SMTP client that end in
+<LF> instead of the standard <CR><LF>. Such line
+endings are commonly allowed with UNIX\-based SMTP servers, but they
+violate RFC 5321, and allowing such line endings can make a server
+vulnerable to
+SMTP smuggling.
+.PP
+Specify one of the following values (case does not matter):
+.IP "\fBnormalize\fR"
+Require the standard
+End\-of\-DATA sequence <CR><LF>.<CR><LF>.
+Otherwise, allow command or message content lines ending in the
+non\-standard <LF>, and process them as if the client sent the
+standard <CR><LF>.
+.br
+.br
+This maintains compatibility
+with many legitimate SMTP client applications that send a mix of
+standard and non\-standard line endings, but will fail to receive
+email from client implementations that do not terminate DATA content
+with the standard End\-of\-DATA sequence
+<CR><LF>.<CR><LF>.
+.br
+.br
+Such clients
+can be excluded with smtpd_forbid_bare_newline_exclusions.
+.br
+.IP "\fByes\fR"
+Compatibility alias for \fBnormalize\fR.
+.br
+.IP "\fBreject\fR"
+Require the standard End\-of\-DATA
+sequence <CR><LF>.<CR><LF>. Reject a command
+or message content when a line contains bare <LF>, log a "bare
+<LF> received" error, and reply with the SMTP status code in
+$smtpd_forbid_bare_newline_reject_code.
+.br
+.br
+This will reject
+email from SMTP clients that send any non\-standard line endings
+such as web applications, netcat, or load balancer health checks.
+.br
+.br
+Such clients can be
+excluded with smtpd_forbid_bare_newline_exclusions.
+.br
+.IP "\fBno\fR (default)"
+Do not require the standard
+End\-of\-DATA
+sequence <CR><LF>.<CR><LF>. Always process
+a bare <LF> as if the client sent <CR><LF>. This
+option is fully backwards compatible, but is not recommended for
+an Internet\-facing SMTP server, because it is vulnerable to SMTP smuggling.
+.br
+.br
+.PP
+Recommended settings:
+.sp
+.in +4
+.nf
+.na
+.ft C
+# Require the standard End\-of\-DATA sequence <CR><LF>.<CR><LF>.
+# Otherwise, allow bare <LF> and process it as if the client sent
+# <CR><LF>.
+#
+# This maintains compatibility with many legitimate SMTP client
+# applications that send a mix of standard and non\-standard line
+# endings, but will fail to receive email from client implementations
+# that do not terminate DATA content with the standard End\-of\-DATA
+# sequence <CR><LF>.<CR><LF>.
+#
+# Such clients can be allowlisted with smtpd_forbid_bare_newline_exclusions.
+# The example below allowlists SMTP clients in trusted networks.
+#
+smtpd_forbid_bare_newline = normalize
+smtpd_forbid_bare_newline_exclusions = $mynetworks
+.fi
+.ad
+.ft R
+.in -4
+.PP
+Alternative:
+.sp
+.in +4
+.nf
+.na
+.ft C
+# Reject input lines that contain <LF> and log a "bare <LF> received"
+# error. Require that input lines end in <CR><LF>, and require the
+# standard End\-of\-DATA sequence <CR><LF>.<CR><LF>.
+#
+# This will reject email from SMTP clients that send any non\-standard
+# line endings such as web applications, netcat, or load balancer
+# health checks.
+#
+# Such clients can be allowlisted with smtpd_forbid_bare_newline_exclusions.
+# The example below allowlists SMTP clients in trusted networks.
+#
+smtpd_forbid_bare_newline = reject
+smtpd_forbid_bare_newline_exclusions = $mynetworks
+.fi
+.ad
+.ft R
+.in -4
+.PP
+This feature with settings \fByes\fR and \fBno\fR is available
+in Postfix 3.8.4, 3.7.9, 3.6.13, and 3.5.23. Additionally, the
+settings \fBreject\fR, and \fBnormalize\fR are available with
+Postfix >= 3.9, 3.8.5, 3.7.10, 3.6.14, and 3.5.24.
+.SH smtpd_forbid_bare_newline_exclusions (default: $mynetworks)
+Exclude the specified clients from smtpd_forbid_bare_newline
+enforcement. This setting uses the same syntax and parent\-domain
+matching behavior as mynetworks.
+.PP
+This feature is available in Postfix >= 3.9, 3.8.4, 3.7.9,
+3.6.13, and 3.5.23.
+.SH smtpd_forbid_bare_newline_reject_code (default: 550)
+The numerical Postfix SMTP server response code when rejecting a
+request with "smtpd_forbid_bare_newline = reject".
+Specify a 5XX status code (521 to disconnect).
+.PP
+This feature is available in Postfix >= 3.9, 3.8.5, 3.7.10,
+3.6.14, and 3.5.24.
.SH smtpd_forbidden_commands (default: CONNECT, GET, POST)
List of commands that cause the Postfix SMTP server to immediately
terminate the session with a 221 code. This can be used to disconnect
.IP "\fBmessage_strip_characters (empty)\fR"
The set of characters that Postfix will remove from message
content.
+.PP
+Available in Postfix version 3.9, 3.8.5, 3.7.10, 3.6.14,
+3.5.24, and later:
+.IP "\fBcleanup_replace_stray_cr_lf (yes)\fR"
+Replace each stray <CR> or <LF> character in message
+content with a space character, to prevent outbound SMTP smuggling,
+and to make the evaluation of Postfix\-added DKIM or other signatures
+independent from how a remote mail server handles such characters.
.SH "BEFORE QUEUE MILTER CONTROLS"
.na
.nf
The maximal number of AUTH commands that any client is allowed to
send to this service per time unit, regardless of whether or not
Postfix actually accepts those commands.
+.PP
+Available in Postfix 3.9, 3.8.4, 3.7.9, 3.6.13, 3.5.23 and later:
+.IP "\fBsmtpd_forbid_bare_newline (Postfix < 3.9: no)\fR"
+Reject or restrict input lines from an SMTP client that end in
+<LF> instead of the standard <CR><LF>.
+.IP "\fBsmtpd_forbid_bare_newline_exclusions ($mynetworks)\fR"
+Exclude the specified clients from smtpd_forbid_bare_newline
+enforcement.
+.PP
+Available in Postfix 3.9, 3.8.5, 3.7.10, 3.6.14, 3.5.24 and
+later:
+.IP "\fBsmtpd_forbid_bare_newline_reject_code (550)\fR"
+The numerical Postfix SMTP server response code when rejecting a
+request with "smtpd_forbid_bare_newline = reject".
.SH "TARPIT CONTROLS"
.na
.nf
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">$&</a>;g;
+ s;\bsmtpd_for[-</bB>]*\n*[ <bB>]*bid_bare_new[-</bB>]*\n*[ <bB>]*line\b;<a href="postconf.5.html#smtpd_forbid_bare_newline">$&</a>;g;
+ s;\bsmtpd_for[-</bB>]*\n*[ <bB>]*bid_bare_new[-</bB>]*\n*[ <bB>]*line_reject_code\b;<a href="postconf.5.html#smtpd_forbid_bare_newline_reject_code">$&</a>;g;
+ s;\bsmtpd_for[-</bB>]*\n*[ <bB>]*bid_bare_new[-</bB>]*\n*[ <bB>]*line_exclusions\b;<a href="postconf.5.html#smtpd_forbid_bare_newline_exclusions">$&</a>;g;
+ s;\bcleanup_replace_stray_cr_lf\b;<a href="postconf.5.html#cleanup_replace_stray_cr_lf">$&</a>;g;
s;\bsmtpd_hard_error_limit\b;<a href="postconf.5.html#smtpd_hard_error_limit">$&</a>;g;
s;\bsmtpd_helo_required\b;<a href="postconf.5.html#smtpd_helo_required">$&</a>;g;
s;\bsmtpd_helo_restrictions\b;<a href="postconf.5.html#smtpd_helo_restrictions">$&</a>;g;
<p> This feature was backported from Postfix 3.6 to Postfix versions
3.5.9, 3.4.19, 3.3.16. 3.2.21. </p>
+
+%PARAM smtpd_forbid_bare_newline Postfix < 3.9: no
+
+<p> Reject or restrict input lines from an SMTP client that end in
+<LF> instead of the standard <CR><LF>. Such line
+endings are commonly allowed with UNIX-based SMTP servers, but they
+violate RFC 5321, and allowing such line endings can make a server
+vulnerable to <a href="https://www.postfix.org/smtp-smuggling.html">
+SMTP smuggling</a>. </p>
+
+<p> Specify one of the following values (case does not matter): </p>
+
+<dl compact>
+
+<dt> <b>normalize</b></dt> <dd> Require the standard
+End-of-DATA sequence <CR><LF>.<CR><LF>.
+Otherwise, allow command or message content lines ending in the
+non-standard <LF>, and process them as if the client sent the
+standard <CR><LF>. <br> <br> This maintains compatibility
+with many legitimate SMTP client applications that send a mix of
+standard and non-standard line endings, but will fail to receive
+email from client implementations that do not terminate DATA content
+with the standard End-of-DATA sequence
+<CR><LF>.<CR><LF>. <br> <br> Such clients
+can be excluded with smtpd_forbid_bare_newline_exclusions. </dd>
+
+<dt> <b>yes</b> </dt> <dd> Compatibility alias for <b>normalize</b>. </dd>
+
+<dt> <b>reject</b> </dt> <dd> Require the standard End-of-DATA
+sequence <CR><LF>.<CR><LF>. Reject a command
+or message content when a line contains bare <LF>, log a "bare
+<LF> received" error, and reply with the SMTP status code in
+$smtpd_forbid_bare_newline_reject_code. <br> <br> This will reject
+email from SMTP clients that send any non-standard line endings
+such as web applications, netcat, or load balancer health checks.
+<br> <br> Such clients can be
+excluded with smtpd_forbid_bare_newline_exclusions. </dd>
+
+<dt> <b>no</b> (default)</dt> <dd> Do not require the standard
+End-of-DATA
+sequence <CR><LF>.<CR><LF>. Always process
+a bare <LF> as if the client sent <CR><LF>. This
+option is fully backwards compatible, but is not recommended for
+an Internet-facing SMTP server, because it is vulnerable to <a
+href="https://www.postfix.org/smtp-smuggling.html"> SMTP smuggling</a>.
+</dd>
+
+</dl>
+
+<p> Recommended settings: </p>
+
+<blockquote>
+<pre>
+# Require the standard End-of-DATA sequence <CR><LF>.<CR><LF>.
+# Otherwise, allow bare <LF> and process it as if the client sent
+# <CR><LF>.
+#
+# This maintains compatibility with many legitimate SMTP client
+# applications that send a mix of standard and non-standard line
+# endings, but will fail to receive email from client implementations
+# that do not terminate DATA content with the standard End-of-DATA
+# sequence <CR><LF>.<CR><LF>.
+#
+# Such clients can be allowlisted with smtpd_forbid_bare_newline_exclusions.
+# The example below allowlists SMTP clients in trusted networks.
+#
+smtpd_forbid_bare_newline = normalize
+smtpd_forbid_bare_newline_exclusions = $mynetworks
+</pre>
+</blockquote>
+
+<p> Alternative: </p>
+
+<blockquote>
+<pre>
+# Reject input lines that contain <LF> and log a "bare <LF> received"
+# error. Require that input lines end in <CR><LF>, and require the
+# standard End-of-DATA sequence <CR><LF>.<CR><LF>.
+#
+# This will reject email from SMTP clients that send any non-standard
+# line endings such as web applications, netcat, or load balancer
+# health checks.
+#
+# Such clients can be allowlisted with smtpd_forbid_bare_newline_exclusions.
+# The example below allowlists SMTP clients in trusted networks.
+#
+smtpd_forbid_bare_newline = reject
+smtpd_forbid_bare_newline_exclusions = $mynetworks
+</pre>
+</blockquote>
+
+<p> This feature with settings <b>yes</b> and <b>no</b> is available
+in Postfix 3.8.4, 3.7.9, 3.6.13, and 3.5.23. Additionally, the
+settings <b>reject</b>, and <b>normalize</b> are available with
+Postfix ≥ 3.9, 3.8.5, 3.7.10, 3.6.14, and 3.5.24. </p>
+
+%PARAM smtpd_forbid_bare_newline_exclusions $mynetworks
+
+<p> Exclude the specified clients from smtpd_forbid_bare_newline
+enforcement. This setting uses the same syntax and parent-domain
+matching behavior as mynetworks. </p>
+
+<p> This feature is available in Postfix ≥ 3.9, 3.8.4, 3.7.9,
+3.6.13, and 3.5.23. </p>
+
+%PARAM smtpd_forbid_bare_newline_reject_code 550
+
+<p>
+The numerical Postfix SMTP server response code when rejecting a
+request with "smtpd_forbid_bare_newline = reject".
+Specify a 5XX status code (521 to disconnect).
+</p>
+
+<p> This feature is available in Postfix ≥ 3.9, 3.8.5, 3.7.10,
+3.6.14, and 3.5.24. </p>
+
+%PARAM cleanup_replace_stray_cr_lf yes
+
+<p> Replace each stray <CR> or <LF> character in message
+content with a space character, to prevent outbound SMTP smuggling,
+and to make the evaluation of Postfix-added DKIM or other signatures
+independent from how a remote mail server handles such characters.
+</p>
+
+<p> SMTP does not allow such characters unless they are part of a
+<CR><LF> sequence, and different mail systems handle
+such stray characters in an implementation-dependent manner. Stray
+<CR> or <LF> characters could be used for outbound
+SMTP smuggling, where an attacker uses a Postfix server to send
+message content with a non-standard End-of-DATA sequence that
+triggers inbound SMTP smuggling at a remote SMTP server.</p>
+
+<p> The replacement happens before all other content management,
+and before Postfix may add a DKIM etc. signature; if the signature
+were created first, the replacement could invalidate the signature.
+</p>
+
+<p> In addition to preventing SMTP smuggling, replacing stray
+<CR> or <LF> characters ensures that the result of
+signature validation by later mail system will not depend on how
+that mail system handles those stray characters in an
+implementation-dependent manner. </p>
+
+<p> This feature is available in Postfix ≥ 3.9, 3.8.5, 3.7.10,
+3.6.14, and 3.5.24. </p>
+
/* .IP "\fBmessage_strip_characters (empty)\fR"
/* The set of characters that Postfix will remove from message
/* content.
+/* .PP
+/* Available in Postfix version 3.9, 3.8.5, 3.7.10, 3.6.14,
+/* 3.5.24, and later:
+/* .IP "\fBcleanup_replace_stray_cr_lf (yes)\fR"
+/* Replace each stray <CR> or <LF> character in message
+/* content with a space character, to prevent outbound SMTP smuggling,
+/* and to make the evaluation of Postfix-added DKIM or other signatures
+/* independent from how a remote mail server handles such characters.
/* BEFORE QUEUE MILTER CONTROLS
/* .ad
/* .fi
int var_always_add_hdrs; /* always add missing headers */
int var_virt_addrlen_limit; /* stop exponential growth */
char *var_hfrom_format; /* header_from_format */
+int var_cleanup_mask_stray_cr_lf; /* replace stray CR or LF with space */
const CONFIG_INT_TABLE cleanup_int_table[] = {
VAR_HOPCOUNT_LIMIT, DEF_HOPCOUNT_LIMIT, &var_hopcount_limit, 1, 0,
VAR_VERP_BOUNCE_OFF, DEF_VERP_BOUNCE_OFF, &var_verp_bounce_off,
VAR_AUTO_8BIT_ENC_HDR, DEF_AUTO_8BIT_ENC_HDR, &var_auto_8bit_enc_hdr,
VAR_ALWAYS_ADD_HDRS, DEF_ALWAYS_ADD_HDRS, &var_always_add_hdrs,
+ VAR_CLEANUP_MASK_STRAY_CR_LF, DEF_CLEANUP_MASK_STRAY_CR_LF, &var_cleanup_mask_stray_cr_lf,
0,
};
const char *cp;
char *dst;
+ /*
+ * Replace each stray CR or LF with one space. These are not allowed in
+ * SMTP, and can be used to enable outbound (remote) SMTP smuggling.
+ * Replacing these early ensures that our later DKIM etc. signature will
+ * not be invalidated. Besides preventing SMTP smuggling, replacing stray
+ * <CR> or <LF> ensures that the result of signature validation by a
+ * later mail system will not depend on how that mail system handles
+ * those stray characters in an implementation-dependent manner.
+ *
+ * The input length is not changed, therefore it is safe to overwrite the
+ * input.
+ */
+ if (var_cleanup_mask_stray_cr_lf)
+ for (dst = (char *) buf; dst < buf + len; dst++)
+ if (*dst == '\r' || *dst == '\n')
+ *dst = ' ';
+
/*
* Reject unwanted characters.
*
CLEANUP_STAT_SIZE, 552, "5.3.4", "message file too big",
CLEANUP_STAT_CONT, 550, "5.7.1", "message content rejected",
CLEANUP_STAT_WRITE, 451, "4.3.0", "queue file write error",
+ CLEANUP_STAT_BARE_LF, 521, "5.5.2", "bare <LF> received",
};
static CLEANUP_STAT_DETAIL cleanup_stat_success = {
#define CLEANUP_STAT_PROXY (1<<7) /* Proxy reject */
#define CLEANUP_STAT_DEFER (1<<8) /* Temporary reject */
+ /*
+ * Non-cleanup errors that live in the same bitmask space, to centralize
+ * error handling.
+ */
+#define CLEANUP_STAT_BARE_LF (1<<16) /* Bare <LF> received */
+
/*
* These are set when we can't bounce even if we were asked to.
*/
#define DEF_SMTPD_DNS_RE_FILTER ""
extern char *var_smtpd_dns_re_filter;
+ /*
+ * Backwards compatibility.
+ */
+#define VAR_SMTPD_FORBID_BARE_LF "smtpd_forbid_bare_newline"
+#define DEF_SMTPD_FORBID_BARE_LF "no"
+
+#define VAR_SMTPD_FORBID_BARE_LF_EXCL "smtpd_forbid_bare_newline_exclusions"
+#define DEF_SMTPD_FORBID_BARE_LF_EXCL "$" VAR_MYNETWORKS
+
+#define VAR_SMTPD_FORBID_BARE_LF_CODE "smtpd_forbid_bare_newline_reject_code"
+#define DEF_SMTPD_FORBID_BARE_LF_CODE 550
+
+#define VAR_CLEANUP_MASK_STRAY_CR_LF "cleanup_replace_stray_cr_lf"
+#define DEF_CLEANUP_MASK_STRAY_CR_LF 1
+extern int var_cleanup_mask_stray_cr_lf;
+
/*
* Location of shared-library files.
*
/* VSTREAM *stream;
/* char *format;
/* va_list ap;
+/*
+/* int smtp_detect_bare_lf;
+/* int smtp_got_bare_lf;
/* LEGACY API
/* void smtp_timeout_setup(stream, timeout)
/* VSTREAM *stream;
/*
/* smtp_vprintf() is the machine underneath smtp_printf().
/*
+/* This function assigns smtp_got_bare_lf = smtp_detect_bare_lf,
+/* if smtp_detect_bare_lf is non-zero and the last read line
+/* was terminated with a bare newline. Otherwise, this function
+/* sets smtp_got_bare_lf to zero.
+/*
/* smtp_timeout_setup() is a backwards-compatibility interface
/* for programs that don't require per-record deadline support.
/* DIAGNOSTICS
#include "smtp_stream.h"
+int smtp_detect_bare_lf;
+int smtp_got_bare_lf;
+
/* smtp_timeout_reset - reset per-stream error flags, restart deadline timer */
static void smtp_timeout_reset(VSTREAM *stream)
int last_char;
int next_char;
+ smtp_got_bare_lf = 0;
+
/*
* It's painful to do I/O with records that may span multiple buffers.
* Allow for partial long lines (we will read the remainder later) and
*/
case '\n':
vstring_truncate(vp, VSTRING_LEN(vp) - 1);
- while (VSTRING_LEN(vp) > 0 && vstring_end(vp)[-1] == '\r')
- vstring_truncate(vp, VSTRING_LEN(vp) - 1);
+ if (smtp_detect_bare_lf) {
+ if (VSTRING_LEN(vp) == 0 || vstring_end(vp)[-1] != '\r')
+ smtp_got_bare_lf = smtp_detect_bare_lf;
+ else
+ vstring_truncate(vp, VSTRING_LEN(vp) - 1);
+ } else {
+ while (VSTRING_LEN(vp) > 0 && vstring_end(vp)[-1] == '\r')
+ vstring_truncate(vp, VSTRING_LEN(vp) - 1);
+ }
VSTRING_TERMINATE(vp);
/* FALLTRHOUGH */
extern void smtp_fputs(const char *, ssize_t len, VSTREAM *);
extern void smtp_fwrite(const char *, ssize_t len, VSTREAM *);
extern void smtp_fputc(int, VSTREAM *);
+extern int smtp_detect_bare_lf;
+extern int smtp_got_bare_lf;
extern void smtp_vprintf(VSTREAM *, const char *, va_list);
/* 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.
+/* .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"
+/* Reject or restrict input lines from an SMTP client that end in
+/* <LF> instead of the standard <CR><LF>.
+/* .IP "\fBsmtpd_forbid_bare_newline_exclusions ($mynetworks)\fR"
+/* Exclude the specified clients from smtpd_forbid_bare_newline
+/* enforcement.
+/* .PP
+/* Available in Postfix 3.9, 3.8.5, 3.7.10, 3.6.14, 3.5.24 and
+/* later:
+/* .IP "\fBsmtpd_forbid_bare_newline_reject_code (550)\fR"
+/* The numerical Postfix SMTP server response code when rejecting a
+/* request with "smtpd_forbid_bare_newline = reject".
/* TARPIT CONTROLS
/* .ad
/* .fi
char *var_smtpd_uproxy_proto;
int var_smtpd_uproxy_tmout;
+char *var_smtpd_forbid_bare_lf;
+char *var_smtpd_forbid_bare_lf_excl;
+int var_smtpd_forbid_bare_lf_code;
+static int bare_lf_mask;
+static NAMADR_LIST *bare_lf_excl;
+
/*
* Silly little macros.
*/
*/
static DICT *smtpd_cmd_filter;
+ /*
+ * Bare LF and End-of-DATA controls (bare CR is handled elsewhere).
+ *
+ * At the smtp_get*() line reader level, setting any of these flags in the
+ * smtp_detect_bare_lf variable enables the detection of bare newlines. The
+ * line reader will set the same flags in the smtp_got_bare_lf variable
+ * after it detects a bare newline, otherwise it clears smtp_got_bare_lf.
+ *
+ * At the SMTP command level, the flags in smtp_got_bare_lf control whether
+ * commands ending in a bare newline are rejected.
+ *
+ * At the DATA and BDAT content level, the flags in smtp_got_bare_lf control
+ * whether the standard End-of-DATA sequence CRLF.CRLF is required, and
+ * whether lines ending in bare newlines are rejected.
+ *
+ * Postfix implements "delayed reject" after detecting a bare newline in BDAT
+ * or DATA content. The SMTP server delays a REJECT response until the
+ * command is finished, instead of replying and hanging up immediately. The
+ * End-of-DATA detection is secured with BARE_LF_FLAG_WANT_STD_EOD.
+ */
+#define BARE_LF_FLAG_WANT_STD_EOD (1<<0) /* Require CRLF.CRLF */
+#define BARE_LF_FLAG_REPLY_REJECT (1<<1) /* Reject bare newline */
+
+#define IS_BARE_LF_WANT_STD_EOD(m) ((m) & BARE_LF_FLAG_WANT_STD_EOD)
+#define IS_BARE_LF_REPLY_REJECT(m) ((m) & BARE_LF_FLAG_REPLY_REJECT)
+
+static const NAME_CODE bare_lf_mask_table[] = {
+ "normalize", BARE_LF_FLAG_WANT_STD_EOD, /* Default */
+ "yes", BARE_LF_FLAG_WANT_STD_EOD, /* Migration aid */
+ "reject", BARE_LF_FLAG_WANT_STD_EOD | BARE_LF_FLAG_REPLY_REJECT,
+ "no", 0,
+ 0, -1, /* error */
+};
+
#ifdef USE_SASL_AUTH
/*
int curr_rec_type;
int prev_rec_type;
int first = 1;
+ int prev_got_bare_lf = 0;
VSTRING *why = 0;
int saved_err;
int (*out_record) (VSTREAM *, int, const char *, ssize_t);
* XXX Deal with UNIX-style From_ lines at the start of message content
* because sendmail permits it.
*/
- for (prev_rec_type = 0; /* void */ ; prev_rec_type = curr_rec_type) {
+ for (prev_rec_type = 0; /* void */ ; prev_rec_type = curr_rec_type,
+ prev_got_bare_lf = smtp_got_bare_lf) {
if (smtp_get(state->buffer, state->client, var_line_limit,
SMTP_GET_FLAG_NONE) == '\n')
curr_rec_type = REC_TYPE_NORM;
else
curr_rec_type = REC_TYPE_CONT;
+ if (IS_BARE_LF_REPLY_REJECT(smtp_got_bare_lf))
+ state->err |= CLEANUP_STAT_BARE_LF;
start = vstring_str(state->buffer);
len = VSTRING_LEN(state->buffer);
if (first) {
if (len > 0 && IS_SPACE_TAB(start[0]))
out_record(out_stream, REC_TYPE_NORM, "", 0);
}
- if (prev_rec_type != REC_TYPE_CONT && *start == '.'
- && (proxy == 0 ? (++start, --len) == 0 : len == 1))
- break;
+ if (prev_rec_type != REC_TYPE_CONT && *start == '.') {
+ if (len == 1 && IS_BARE_LF_WANT_STD_EOD(smtp_detect_bare_lf)
+ && (smtp_got_bare_lf || prev_got_bare_lf))
+ /* Do not store or send to proxy filter. */
+ continue;
+ if (proxy == 0 ? (++start, --len) == 0 : len == 1)
+ break;
+ }
if (state->err == CLEANUP_STAT_OK) {
if (var_message_limit > 0 && var_message_limit - state->act_size < len + 2) {
state->err = CLEANUP_STAT_SIZE;
else
smtpd_chat_reply(state,
"250 2.0.0 Ok: queued as %s", state->queue_id);
+ } else if ((state->err & CLEANUP_STAT_BARE_LF) != 0) {
+ state->error_mask |= MAIL_ERROR_PROTOCOL;
+ log_whatsup(state, "reject", "bare <LF> received");
+ smtpd_chat_reply(state, "%d 5.5.2 %s Error: bare <LF> received",
+ var_smtpd_forbid_bare_lf_code, var_myhostname);
} else if (why && IS_SMTP_REJECT(STR(why))) {
state->error_mask |= MAIL_ERROR_POLICY;
smtpd_chat_reply(state, "%s", STR(why));
*/
xclient_allowed =
namadr_list_match(xclient_hosts, state->name, state->addr);
+ smtp_detect_bare_lf = (SMTPD_STAND_ALONE((state)) == 0 && bare_lf_mask
+ && !namadr_list_match(bare_lf_excl, state->name, state->addr)) ?
+ bare_lf_mask : 0;
/* NOT: tls_reset() */
if (got_helo == 0)
helo_reset(state);
}
watchdog_pat();
smtpd_chat_query(state);
+ if (IS_BARE_LF_REPLY_REJECT(smtp_got_bare_lf)) {
+ log_whatsup(state, "reject", "bare <LF> received");
+ state->error_mask |= MAIL_ERROR_PROTOCOL;
+ smtpd_chat_reply(state, "%d 5.5.2 %s Error: bare <LF> received",
+ var_smtpd_forbid_bare_lf_code, var_myhostname);
+ break;
+ }
/* Safety: protect internal interfaces against malformed UTF-8. */
if (var_smtputf8_enable && valid_utf8_string(STR(state->buffer),
LEN(state->buffer)) == 0) {
xforward_allowed = SMTPD_STAND_ALONE((&state)) == 0 &&
namadr_list_match(xforward_hosts, state.name, state.addr);
+ /*
+ * Reject or normalize bare LF, with compatibility exclusions.
+ */
+ smtp_detect_bare_lf = (SMTPD_STAND_ALONE((&state)) == 0 && bare_lf_mask
+ && !namadr_list_match(bare_lf_excl, state.name, state.addr)) ?
+ bare_lf_mask : 0;
+
/*
* See if we need to turn on verbose logging for this client.
*/
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);
+ if ((bare_lf_mask = name_code(bare_lf_mask_table, NAME_CODE_FLAG_NONE,
+ var_smtpd_forbid_bare_lf)) < 0)
+ msg_fatal("bad parameter value: '%s = %s'",
+ VAR_SMTPD_FORBID_BARE_LF, var_smtpd_forbid_bare_lf);
/*
* Open maps before dropping privileges so we can read passwords etc.
VAR_VIRT_MAILBOX_CODE, DEF_VIRT_MAILBOX_CODE, &var_virt_mailbox_code, 0, 0,
VAR_RELAY_RCPT_CODE, DEF_RELAY_RCPT_CODE, &var_relay_rcpt_code, 0, 0,
VAR_PLAINTEXT_CODE, DEF_PLAINTEXT_CODE, &var_plaintext_code, 0, 0,
+ VAR_SMTPD_FORBID_BARE_LF_CODE, DEF_SMTPD_FORBID_BARE_LF_CODE, &var_smtpd_forbid_bare_lf_code, 500, 599,
VAR_SMTPD_CRATE_LIMIT, DEF_SMTPD_CRATE_LIMIT, &var_smtpd_crate_limit, 0, 0,
VAR_SMTPD_CCONN_LIMIT, DEF_SMTPD_CCONN_LIMIT, &var_smtpd_cconn_limit, 0, 0,
VAR_SMTPD_CMAIL_LIMIT, DEF_SMTPD_CMAIL_LIMIT, &var_smtpd_cmail_limit, 0, 0,
VAR_SMTPD_POLICY_DEF_ACTION, DEF_SMTPD_POLICY_DEF_ACTION, &var_smtpd_policy_def_action, 1, 0,
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_FORBID_BARE_LF_EXCL, DEF_SMTPD_FORBID_BARE_LF_EXCL, &var_smtpd_forbid_bare_lf_excl, 0, 0,
+ VAR_SMTPD_FORBID_BARE_LF, DEF_SMTPD_FORBID_BARE_LF, &var_smtpd_forbid_bare_lf, 1, 0,
0,
};
static const CONFIG_RAW_TABLE raw_table[] = {
/*
/* char *smtpd_check_queue(state)
/* SMTPD_STATE *state;
+/* AUXILIARY FUNCTIONS
+/* void log_whatsup(state, action, text)
+/* SMTPD_STATE *state;
+/* const char *action;
+/* const char *text;
/* DESCRIPTION
/* This module implements additional checks on SMTP client requests.
/* A client request is validated in the context of the session state.
/* The recipient address given with the RCPT TO or VRFY command.
/* .IP size
/* The message size given with the MAIL FROM command (zero if unknown).
+/* .PP
+/* log_whatsup() logs "<queueid>: <action>: <protocol state>
+/* from: <client-name[client-addr]>: <text>" plus the protocol
+/* (SMTP or ESMTP), and if available, EHLO, MAIL FROM, or RCPT
+/* TO.
/* BUGS
/* Policies like these should not be hard-coded in C, but should
/* be user-programmable instead.
/* log_whatsup - log as much context as we have */
-static void log_whatsup(SMTPD_STATE *state, const char *whatsup,
- const char *text)
+void log_whatsup(SMTPD_STATE *state, const char *whatsup,
+ const char *text)
{
VSTRING *buf = vstring_alloc(100);
extern char *smtpd_check_data(SMTPD_STATE *);
extern char *smtpd_check_eod(SMTPD_STATE *);
extern char *smtpd_check_policy(SMTPD_STATE *, char *);
+extern void log_whatsup(SMTPD_STATE *, const char *, const char *);
/* LICENSE
/* .ad
projects / thirdparty / postfix.git / commitdiff
