postfix-2.11-20130710

postfix/HISTORY

@@ -18782,3 +18782,17 @@ Apologies for any names omitted.
 	Logging: minimal DNAME support. Viktor Dukhovni.  dns/dns.h,
 	dns/dns_lookup.c, dns/dns_strtype.c, dns/test_dns_lookup.c.
 
+20130710
+
+	Workaround: smtp_connection_reuse_count_limit (default 0,
+	i.e.  unlimited) for sites that must deal with hostile
+	connection reuse policies. The documentation comes with a
+	warning that this feature introduces a "fatal attractor"
+	failure mode.  Files: global/mail_params.h, mantools/postlink,
+	proto/postconf.proto, smtp/smtp.c, smtp/smtp_params.c,
+	smtp/lmtp_params.c, smtp/smtp.h.
+
+	Workaround: FreeBSD9 nroff outputs ANSI escape sequences
+	instead of overstrike sequences. To make matters worse, it
+	uses the ESC[0m sequence sometimes for end-of-bold and
+	sometimes for end-of-italic.  File: mantools/man2html.

postfix/README_FILES/CONNECTION_CACHE_README

@@ -148,12 +148,17 @@ mechanisms:
     times. This avoids triggering bugs in implementations that do not correctly
     handle multiple deliveries per session.
 
-    With Postfix 2.2 the use count is limited with the
+    As of Postfix 2.3 connection reuse is preferably limited with the
-    smtp_connection_cache_reuse_limit configuration parameter. With Postfix 2.3
+    smtp_connection_reuse_time_limit parameter. In addition, Postfix 2.11
-    this is replaced by a time limit which is specified with the
+    provides smtp_connection_reuse_count_limit to limit how many times a
-    smtp_connection_reuse_time_limit parameter. In addition, Postfix 2.3 logs
+    connection may be reused, but this feature is unsafe as it introduces a
-    the use count of multiply-used connections, as shown in the following
+    "fatal attractor" failure mode (when a destination has multiple inbound
-    example:
+    MTAs, the slowest inbound MTA will attract most connections from Postfix to
+    that destination).
+
+    .
+    Postfix 2.3 logs the use count of multiply-used connections, as shown in
+    the following example:
 
         Nov  3 16:04:31 myname postfix/smtp[30840]: 19B6B2900FE:
         to=<wietse@test.example.com>, orig_to=<wietse@test>,

postfix/html/CONNECTION_CACHE_README.html

@@ -226,11 +226,15 @@ configuration parameters. This prevents anti-social behavior. </p>
 limited number of times. This avoids triggering bugs in implementations
 that do not correctly handle multiple deliveries per session. </p>
 
-<p> With Postfix 2.2 the use count is limited with the
+<p> As of Postfix 2.3 connection reuse is preferably limited with
-<a href="postconf.5.html#smtp_connection_cache_reuse_limit">smtp_connection_cache_reuse_limit</a> configuration parameter. With
+the <a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> parameter. In addition, Postfix
-Postfix 2.3 this is replaced by a time limit which is specified
+2.11 provides <a href="postconf.5.html#smtp_connection_reuse_count_limit">smtp_connection_reuse_count_limit</a> to limit how many
-with the <a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> parameter. In addition,
+times a connection may be reused, but this feature is unsafe as it
-Postfix 2.3 logs the use count of multiply-used connections,
+introduces a "fatal attractor" failure mode (when a destination has
+multiple inbound MTAs, the slowest inbound MTA will attract most
+connections from Postfix to that destination).  </p>.
+
+<p> Postfix 2.3 logs the use count of multiply-used connections,
 as shown in the following example: </p>
 
 <blockquote>

postfix/html/lmtp.8.html

@@ -79,7 +79,7 @@ SMTP(8)                                                                SMTP(8)
 
        <b>inet</b>:<i>hostname</i>
 
-       <b>inet:</b><i>hostname</i>:<i>port</i>
+       <b>inet</b>:<i>hostname</i>:<i>port</i>
 
        <b>inet</b>:[<i>address</i>]
 
@@ -762,6 +762,13 @@ SMTP(8)                                                                SMTP(8)
               SMTP message content line,  or  TLS  protocol  mes-
               sage).
 
+       Available in Postfix version 2.11 and later:
+
+       <b><a href="postconf.5.html#smtp_connection_reuse_count_limit">smtp_connection_reuse_count_limit</a> (0)</b>
+              When SMTP connection caching is enabled, the number
+              of times that an SMTP session may be reused  before
+              it is closed, or zero (no limit).
+
 <b>TROUBLE SHOOTING CONTROLS</b>
        <b><a href="postconf.5.html#debug_peer_level">debug_peer_level</a> (2)</b>
               The  increment  in  verbose  logging  level  when a

postfix/html/postconf.5.html

@@ -3968,6 +3968,17 @@ See there for details. </p>
 <p> This feature is available in Postfix 2.3 and later. </p>
 
 
+</DD>
+
+<DT><b><a name="lmtp_connection_reuse_count_limit">lmtp_connection_reuse_count_limit</a>
+(default: 0)</b></DT><DD>
+
+<p> The LMTP-specific version of the <a href="postconf.5.html#smtp_connection_reuse_count_limit">smtp_connection_reuse_count_limit</a>
+configuration parameter.  See there for details. </p>
+
+<p> This feature is available in Postfix 2.11 and later. </p>
+
+
 </DD>
 
 <DT><b><a name="lmtp_connection_reuse_time_limit">lmtp_connection_reuse_time_limit</a>
@@ -9556,19 +9567,6 @@ delivery performance. </p>
 <p> This feature is available in Postfix 2.2 and later. </p>
 
 
-</DD>
-
-<DT><b><a name="smtp_connection_cache_reuse_limit">smtp_connection_cache_reuse_limit</a>
-(default: 10)</b></DT><DD>
-
-<p> When SMTP connection caching is enabled, the number of times that
-an SMTP session may be reused before it is closed.
-</p>
-
-<p> This feature is available in Postfix 2.2. In Postfix 2.3 it is
-replaced by $<a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a>.</p>
-
-
 </DD>
 
 <DT><b><a name="smtp_connection_cache_time_limit">smtp_connection_cache_time_limit</a>
@@ -9582,6 +9580,24 @@ not specify larger values without permission from the remote sites.
 <p> This feature is available in Postfix 2.2 and later. </p>
 
 
+</DD>
+
+<DT><b><a name="smtp_connection_reuse_count_limit">smtp_connection_reuse_count_limit</a>
+(default: 0)</b></DT><DD>
+
+<p> When SMTP connection caching is enabled, the number of times
+that an SMTP session may be reused before it is closed, or zero (no
+limit).  With a reuse count limit of N, a connection is used up to
+N+1 times.  </p>
+
+<p> NOTE: This feature is unsafe. When a high-volume destination
+has multiple inbound MTAs, then the slowest inbound MTA will attract
+the most connections to that destination.  This limitation does not
+exist with the <a href="postconf.5.html#smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a> feature. </p>
+
+<p> This feature is available in Postfix 2.11. </p>
+
+
 </DD>
 
 <DT><b><a name="smtp_connection_reuse_time_limit">smtp_connection_reuse_time_limit</a>

postfix/html/smtp.8.html

@@ -79,7 +79,7 @@ SMTP(8)                                                                SMTP(8)
 
        <b>inet</b>:<i>hostname</i>
 
-       <b>inet:</b><i>hostname</i>:<i>port</i>
+       <b>inet</b>:<i>hostname</i>:<i>port</i>
 
        <b>inet</b>:[<i>address</i>]
 
@@ -762,6 +762,13 @@ SMTP(8)                                                                SMTP(8)
               SMTP message content line,  or  TLS  protocol  mes-
               sage).
 
+       Available in Postfix version 2.11 and later:
+
+       <b><a href="postconf.5.html#smtp_connection_reuse_count_limit">smtp_connection_reuse_count_limit</a> (0)</b>
+              When SMTP connection caching is enabled, the number
+              of times that an SMTP session may be reused  before
+              it is closed, or zero (no limit).
+
 <b>TROUBLE SHOOTING CONTROLS</b>
        <b><a href="postconf.5.html#debug_peer_level">debug_peer_level</a> (2)</b>
               The  increment  in  verbose  logging  level  when a

postfix/man/man5/postconf.5

@@ -2345,6 +2345,11 @@ smtp_connection_cache_time_limit configuration parameter.
 See there for details.
 .PP
 This feature is available in Postfix 2.3 and later.
+.SH lmtp_connection_reuse_count_limit (default: 0)
+The LMTP-specific version of the smtp_connection_reuse_count_limit
+configuration parameter.  See there for details.
+.PP
+This feature is available in Postfix 2.11 and later.
 .SH lmtp_connection_reuse_time_limit (default: 300s)
 The LMTP-specific version of the smtp_connection_reuse_time_limit
 configuration parameter.  See there for details.
@@ -5820,18 +5825,24 @@ connections to be reused for other deliveries, and can improve mail
 delivery performance.
 .PP
 This feature is available in Postfix 2.2 and later.
-.SH smtp_connection_cache_reuse_limit (default: 10)
-When SMTP connection caching is enabled, the number of times that
-an SMTP session may be reused before it is closed.
-.PP
-This feature is available in Postfix 2.2. In Postfix 2.3 it is
-replaced by $smtp_connection_reuse_time_limit.
 .SH smtp_connection_cache_time_limit (default: 2s)
 When SMTP connection caching is enabled, the amount of time that
 an unused SMTP client socket is kept open before it is closed.  Do
 not specify larger values without permission from the remote sites.
 .PP
 This feature is available in Postfix 2.2 and later.
+.SH smtp_connection_reuse_count_limit (default: 0)
+When SMTP connection caching is enabled, the number of times
+that an SMTP session may be reused before it is closed, or zero (no
+limit).  With a reuse count limit of N, a connection is used up to
+N+1 times.
+.PP
+NOTE: This feature is unsafe. When a high-volume destination
+has multiple inbound MTAs, then the slowest inbound MTA will attract
+the most connections to that destination.  This limitation does not
+exist with the smtp_connection_reuse_time_limit feature.
+.PP
+This feature is available in Postfix 2.11.
 .SH smtp_connection_reuse_time_limit (default: 300s)
 The amount of time during which Postfix will use an SMTP
 connection repeatedly.  The timer starts when the connection is

postfix/man/man8/smtp.8

@@ -71,7 +71,7 @@ Connect to the local UNIX-domain server that is bound to the specified
 \fIpathname\fR. If the process runs chrooted, an absolute pathname
 is interpreted relative to the Postfix queue directory.
 .IP \fBinet\fR:\fIhostname\fR
-.IP \fBinet\fB:\fIhostname\fR:\fIport\fR
+.IP \fBinet\fR:\fIhostname\fR:\fIport\fR
 .IP \fBinet\fR:[\fIaddress\fR]
 .IP \fBinet\fR:[\fIaddress\fR]:\fIport\fR
 Connect to the specified TCP port on the specified local or
@@ -596,6 +596,11 @@ Change the behavior of the smtp_*_timeout 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).
+.PP
+Available in Postfix version 2.11 and later:
+.IP "\fBsmtp_connection_reuse_count_limit (0)\fR"
+When SMTP connection caching is enabled, the number of times that
+an SMTP session may be reused before it is closed, or zero (no limit).
 .SH "TROUBLE SHOOTING CONTROLS"
 .na
 .nf

postfix/mantools/man2html

@@ -18,6 +18,8 @@ echo "<!doctype html public \"-//W3C//DTD HTML 4.01 Transitional//EN\"
 <title> $title </title>
 </head> <body> <pre>"
 
+ESC=`echo x | tr '[x]' '[\033]'`
+
 sed '
 	s/\([<>&]\)\1/\1/g
 	s/&/\&amp;/g
@@ -29,6 +31,24 @@ sed '
 	s/>/\&gt;/g
 	s;_\([^_]\);<i>\1</i>;g
 	s;.\(.\);<b>\1</b>;g
+	# Why change nroff to hard-coded ANSI escape sequences?
+	/'$ESC'\[0m$/{
+		/'$ESC'\[1m[^'$ESC']*'$ESC'\[0m$/{
+			# Here, ESC[0m means end-of-bold.
+			s;0m$;22m;
+		}
+		/'$ESC'\[4m[^'$ESC']*'$ESC'\[0m$/{
+			# Here, ESC[0m means end-of-italic.
+			s;0m$;24m;
+		}
+	}
+	s;'$ESC'\[1m;<b>;g
+	s;'$ESC'\[22m;</b>;g
+	s;'$ESC'\[4m;<i>;g
+	s;'$ESC'\[24m;</i>;g
+	# Undo gratuitous whitespace changes.
+	s;\(  *\)\(</[bi]>\);\2\1;g
+	# End nroff ANSI escape sequence workarounds.
 	s;</i>\( *\)<i>;\1;g
 	s;</b>\( *\)<b>;\1;g
 ' "$@" | egrep -v 'postconf (readme|html)_direc|tory</b>" *to *locate *this'

postfix/mantools/postlink

@@ -264,6 +264,7 @@ while (<>) {
     s;\blmtp_pix_workaround_delay_time\b;<a href="postconf.5.html#lmtp_pix_workaround_delay_time">$&</a>;g;
     s;\blmtp_pix_workarounds\b;<a href="postconf.5.html#lmtp_pix_workarounds">$&</a>;g;
     s;\blmtp_pix_workaround_maps\b;<a href="postconf.5.html#lmtp_pix_workaround_maps">$&</a>;g;
+    s;\blmtp_connection_reuse_count_limit\b;<a href="postconf.5.html#lmtp_connection_reuse_count_limit">$&</a>;g;
     s;\blmtp_connection_reuse_time_limit\b;<a href="postconf.5.html#lmtp_connection_reuse_time_limit">$&</a>;g;
     s;\blmtp_starttls_timeout\b;<a href="postconf.5.html#lmtp_starttls_timeout">$&</a>;g;
     s;\blmtp_line_length_limit\b;<a href="postconf.5.html#lmtp_line_length_limit">$&</a>;g;
@@ -444,7 +445,7 @@ while (<>) {
     s;\bsmtp_connect_timeout\b;<a href="postconf.5.html#smtp_connect_timeout">$&</a>;g;
 
     s;\bsmtp_connection_cache_on_demand\b;<a href="postconf.5.html#smtp_connection_cache_on_demand">$&</a>;g;
-    s;\bsmtp_connection_cache_reuse_limit\b;<a href="postconf.5.html#smtp_connection_cache_reuse_limit">$&</a>;g;
+    s;\bsmtp_connection_reuse_count_limit\b;<a href="postconf.5.html#smtp_connection_reuse_count_limit">$&</a>;g;
     s;\bsmtp_connection_reuse_time_limit\b;<a href="postconf.5.html#smtp_connection_reuse_time_limit">$&</a>;g;
     s;\bsmtp_connection_cache_time_limit\b;<a href="postconf.5.html#smtp_connection_cache_time_limit">$&</a>;g;
     s;\bsmtp_connection_cache_destinations\b;<a href="postconf.5.html#smtp_connection_cache_destinations">$&</a>;g;

postfix/proto/CONNECTION_CACHE_README.html

@@ -226,11 +226,15 @@ configuration parameters. This prevents anti-social behavior. </p>
 limited number of times. This avoids triggering bugs in implementations
 that do not correctly handle multiple deliveries per session. </p>
 
-<p> With Postfix 2.2 the use count is limited with the
+<p> As of Postfix 2.3 connection reuse is preferably limited with
-smtp_connection_cache_reuse_limit configuration parameter. With
+the smtp_connection_reuse_time_limit parameter. In addition, Postfix
-Postfix 2.3 this is replaced by a time limit which is specified
+2.11 provides smtp_connection_reuse_count_limit to limit how many
-with the smtp_connection_reuse_time_limit parameter. In addition,
+times a connection may be reused, but this feature is unsafe as it
-Postfix 2.3 logs the use count of multiply-used connections,
+introduces a "fatal attractor" failure mode (when a destination has
+multiple inbound MTAs, the slowest inbound MTA will attract most
+connections from Postfix to that destination).  </p>.
+
+<p> Postfix 2.3 logs the use count of multiply-used connections,
 as shown in the following example: </p>
 
 <blockquote>

postfix/proto/postconf.proto

@@ -3907,15 +3907,6 @@ not specify larger values without permission from the remote sites.
 
 <p> This feature is available in Postfix 2.2 and later. </p>
 
-%PARAM smtp_connection_cache_reuse_limit 10
-
-<p> When SMTP connection caching is enabled, the number of times that
-an SMTP session may be reused before it is closed. 
-</p>
-
-<p> This feature is available in Postfix 2.2. In Postfix 2.3 it is
-replaced by $smtp_connection_reuse_time_limit.</p>
-
 %PARAM smtp_connection_reuse_time_limit 300s
 
 <p> The amount of time during which Postfix will use an SMTP
@@ -15381,3 +15372,24 @@ service maintains TLS session caches and other information in support
 of TLS. </p>
 
 <p> This feature is available in Postfix 2.11 and later. </p>
+
+%PARAM lmtp_connection_reuse_count_limit 0
+
+<p> The LMTP-specific version of the smtp_connection_reuse_count_limit
+configuration parameter.  See there for details. </p>
+
+<p> This feature is available in Postfix 2.11 and later. </p>
+
+%PARAM smtp_connection_reuse_count_limit 0
+
+<p> When SMTP connection caching is enabled, the number of times
+that an SMTP session may be reused before it is closed, or zero (no
+limit).  With a reuse count limit of N, a connection is used up to
+N+1 times.  </p>
+
+<p> NOTE: This feature is unsafe. When a high-volume destination
+has multiple inbound MTAs, then the slowest inbound MTA will attract
+the most connections to that destination.  This limitation does not
+exist with the smtp_connection_reuse_time_limit feature. </p>
+
+<p> This feature is available in Postfix 2.11. </p>

postfix/src/global/mail_params.h

@@ -964,6 +964,12 @@ extern char *var_bestmx_transp;
 #define DEF_LMTP_CACHE_CONNT	"2s"
 extern int var_smtp_cache_conn;
 
+#define VAR_SMTP_REUSE_COUNT	"smtp_connection_reuse_count_limit"
+#define DEF_SMTP_REUSE_COUNT	0
+#define VAR_LMTP_REUSE_COUNT	"lmtp_connection_reuse_count_limit"
+#define DEF_LMTP_REUSE_COUNT	0
+extern int var_smtp_reuse_count;
+
 #define VAR_SMTP_REUSE_TIME	"smtp_connection_reuse_time_limit"
 #define DEF_SMTP_REUSE_TIME	"300s"
 #define VAR_LMTP_REUSE_TIME	"lmtp_connection_reuse_time_limit"

postfix/src/global/mail_version.h

@@ -20,7 +20,7 @@
   * Patches change both the patchlevel and the release date. Snapshots have no
   * patchlevel; they change the release date only.
   */
-#define MAIL_RELEASE_DATE	"20130709"
+#define MAIL_RELEASE_DATE	"20130710"
 #define MAIL_VERSION_NUMBER	"2.11"
 
 #ifdef SNAPSHOT

postfix/src/smtp/lmtp_params.c

@@ -85,6 +85,7 @@
 	VAR_LMTP_LINE_LIMIT, DEF_LMTP_LINE_LIMIT, &var_smtp_line_limit, 0, 0,
 	VAR_LMTP_MXADDR_LIMIT, DEF_LMTP_MXADDR_LIMIT, &var_smtp_mxaddr_limit, 0, 0,
 	VAR_LMTP_MXSESS_LIMIT, DEF_LMTP_MXSESS_LIMIT, &var_smtp_mxsess_limit, 0, 0,
+	VAR_LMTP_REUSE_COUNT, DEF_LMTP_REUSE_COUNT, &var_smtp_reuse_count, 0, 0,
 #ifdef USE_TLS
 	VAR_LMTP_TLS_SCERT_VD, DEF_LMTP_TLS_SCERT_VD, &var_smtp_tls_scert_vd, 0, 0,
 #endif

postfix/src/smtp/smtp.c

@@ -61,7 +61,7 @@
 /*      \fIpathname\fR. If the process runs chrooted, an absolute pathname
 /*      is interpreted relative to the Postfix queue directory.
 /* .IP \fBinet\fR:\fIhostname\fR
-/* .IP \fBinet\fB:\fIhostname\fR:\fIport\fR
+/* .IP \fBinet\fR:\fIhostname\fR:\fIport\fR
 /* .IP \fBinet\fR:[\fIaddress\fR]
 /* .IP \fBinet\fR:[\fIaddress\fR]:\fIport\fR
 /*      Connect to the specified TCP port on the specified local or
@@ -562,6 +562,11 @@
 /*	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).
+/* .PP
+/*	Available in Postfix version 2.11 and later:
+/* .IP "\fBsmtp_connection_reuse_count_limit (0)\fR"
+/*	When SMTP connection caching is enabled, the number of times that
+/*	an SMTP session may be reused before it is closed, or zero (no limit).
 /* TROUBLE SHOOTING CONTROLS
 /* .ad
 /* .fi
@@ -806,6 +811,7 @@ int     var_smtp_mxaddr_limit;
 int     var_smtp_mxsess_limit;
 int     var_smtp_cache_conn;
 int     var_smtp_reuse_time;
+int     var_smtp_reuse_count;
 char   *var_smtp_cache_dest;
 char   *var_scache_service;		/* You can now leave this here. */
 bool    var_smtp_cache_demand;

postfix/src/smtp/smtp.h

@@ -422,7 +422,9 @@ extern HBC_CALL_BACKS smtp_hbc_callbacks[];
 
 #define THIS_SESSION_IS_EXPIRED \
 	(THIS_SESSION_IS_CACHED \
-	    && session->expire_time < vstream_ftime(session->stream))
+	    && (session->expire_time < vstream_ftime(session->stream) \
+		|| (var_smtp_reuse_count > 0 \
+		    && session->reuse_count >= var_smtp_reuse_count)))
 
 #define THIS_SESSION_IS_BAD \
 	(!THIS_SESSION_IS_DEAD && session->expire_time < 0)

postfix/src/smtp/smtp_params.c

@@ -86,6 +86,7 @@
 	VAR_SMTP_LINE_LIMIT, DEF_SMTP_LINE_LIMIT, &var_smtp_line_limit, 0, 0,
 	VAR_SMTP_MXADDR_LIMIT, DEF_SMTP_MXADDR_LIMIT, &var_smtp_mxaddr_limit, 0, 0,
 	VAR_SMTP_MXSESS_LIMIT, DEF_SMTP_MXSESS_LIMIT, &var_smtp_mxsess_limit, 0, 0,
+	VAR_SMTP_REUSE_COUNT, DEF_SMTP_REUSE_COUNT, &var_smtp_reuse_count, 0, 0,
 #ifdef USE_TLS
 	VAR_SMTP_TLS_SCERT_VD, DEF_SMTP_TLS_SCERT_VD, &var_smtp_tls_scert_vd, 0, 0,
 #endif