postfix-1.1.11-20021024

postfix/HISTORY

@@ -7068,6 +7068,13 @@ Apologies for any names omitted.
 	TO addresses. Some remnant of code that someone put in
 	there long ago. File: lmtp/lmtp_proto.c.
 
+20021024
+
+	Feature: proxy_interfaces parameter. Specify your NAT or
+	other proxy addresses here to avoid mail delivery loops.
+	Files: global/mail_params.[hc] global/own_inet_addr.[hc]
+	global/resolve_local.c smtp/smtp_addr.c smtpd/smtpd_check.c.
+
 Open problems:
 
 	Low: smtpd should log queue ID with reject/warn/hold/discard

postfix/RELEASE_NOTES

@@ -12,6 +12,13 @@ snapshot release).  Patches change the patchlevel and the release
 date. Snapshots change only the release date, unless they include
 the same bugfixes as a patch release.
 
+Major changes with Postfix snapshot 1.1.11-20021024
+===================================================
+
+New proxy_interfaces parameter, for sites behind a network address
+translation gateway or other type of proxy. Specify all the proxy
+network addresses here, to avoid avoid mail delivery loops.
+
 Incompatible changes with Postfix snapshot 1.1.11-20021015
 ==========================================================
 

postfix/conf/main.cf

@@ -97,10 +97,25 @@ mail_owner = postfix
 # the software claims all active interfaces on the machine. The
 # parameter also controls delivery of mail to user@[ip.address].
 #
+# See also the proxy_interfaces parameter, for network addresses that
+# are forwarded to us via a proxy or network address translator.
+#
 #inet_interfaces = all
 #inet_interfaces = $myhostname
 #inet_interfaces = $myhostname, localhost
 
+# The proxy_interfaces parameter specifies the network interface
+# addresses that this mail system receives mail on by way of a
+# proxy or network address translation unit. This setting extends
+# the address list specified with the inet_interfaces parameter.
+#
+# You must specify your proxy/NAT addresses when your system is a
+# backup MX host for other domains, otherwise mail delivery loops
+# will happen when the primary MX host is down.
+#
+#proxy_interfaces =
+#proxy_interfaces = 1.2.3.4
+
 # The mydestination parameter specifies the list of domains that this
 # machine considers itself the final destination for. That includes
 # Sendmail-style virtual domains hosted on this machine.

postfix/conf/sample-misc.cf

@@ -119,8 +119,23 @@ import_environment = MAIL_CONFIG MAIL_DEBUG MAIL_LOGTAG TZ XAUTHORITY DISPLAY
 # the software claims all active interfaces on the machine. The
 # parameter also controls delivery of mail to user@[ip.address].
 #
+# See also the proxy_interfaces parameter, for network addresses that
+# are forwarded to us by way of a proxy or address translator.
+#
 inet_interfaces = all
 
+# The proxy_interfaces parameter specifies the network interface
+# addresses that this mail system receives mail on by way of a
+# proxy or network address translation unit. This setting extends
+# the address list specified with the inet_interfaces parameter.
+#
+# You must specify your proxy/NAT addresses when your system is a
+# backup MX host for other domains, otherwise mail delivery loops
+# will happen when the primary MX host is down.
+#
+#proxy_interfaces =
+#proxy_interfaces = 1.2.3.4
+
 # The ipc_idle parameter bounds the idle time for internal communication
 # channels after which a client disconnects voluntarily. The purpose
 # is to allow servers to terminate voluntarily after they become

postfix/html/basic.html

@@ -55,6 +55,18 @@ to the local postmaster:
 
 <p>
 
+Be sure to set the following correctly if you're behind a proxy or
+network address translator, and you are running a backup MX host
+for some other domain:
+
+<p>
+
+<ul>
+
+<li> <a href="#proxy_interfaces"> Proxy/NAT network addresses </a>
+
+</ul>
+
 By the way, if you change parameters of a running Postfix system,
 don't forget to issue a <b>postfix reload</b> command.
 
@@ -261,6 +273,43 @@ due to software problems.
 
 </dl>
 
+<a name="proxy_interfaces"> <h2> Proxy/NAT network addresses </h2> </a>
+
+The <b>proxy_interfaces</b> parameter specifies all network addresses
+that the Postfix receives mail on by way of a proxy or network
+address translation unit. You may specify symbolic hostnames instead
+of network addresses.
+
+<p>
+
+You must specify your proxy/NAT addresses when your system is a
+backup MX host for other domains, otherwise mail delivery loops
+will happen when the primary MX host is down.
+
+<p>
+
+<dl>
+
+<dt> Examples:
+
+<p>
+
+<dl>
+
+<dt> Default:
+
+<dd> <b>proxy_interfaces = </b>
+
+<p>
+
+<dt> Host running backup MTA:
+
+<dd> <b>proxy_interfaces = 1.2.3.4</b> (the proxy/NAT network address)
+
+</dl>
+
+</dl>
+
 <a name="myhostname"> <h2> My own hostname </h2> </a>
 
 The <b>myhostname</b> parameter describes the fully-qualified domain

postfix/html/smtp.8.html

@@ -107,13 +107,22 @@ SMTP(8)                                                   SMTP(8)
               tem  receives  mail on. When any of those addresses
               appears in the list of mail exchangers for a remote
               destination,  the  list  is truncated to avoid mail
-              delivery loops.
+              delivery  loops.   See  also  the  <b>proxy</b><i>_</i><b>interfaces</b>
+              parameter.
 
        <b>notify</b><i>_</i><b>classes</b>
-              When this parameter includes  the  <b>protocol</b>  class,
-              send  mail  to  the  postmaster with transcripts of
+              When  this  parameter  includes the <b>protocol</b> class,
+              send mail to the  postmaster  with  transcripts  of
               SMTP sessions with protocol errors.
 
+       <b>proxy</b><i>_</i><b>interfaces</b>
+              Network  interfaces  that this mail system receives
+              mail on by way of a proxy or network address trans-
+              lator.  When  any of those addresses appears in the
+              list of mail exchangers for a  remote  destination,
+              the list is truncated to avoid mail delivery loops.
+              See also the <b>inet</b><i>_</i><b>interfaces</b> parameter.
+
        <b>smtp</b><i>_</i><b>always</b><i>_</i><b>send</b><i>_</i><b>ehlo</b>
               Always send EHLO at the start of a connection.
 

postfix/man/man8/smtp.8

@@ -108,9 +108,16 @@ The network interface addresses that this mail system receives
 mail on. When any of those addresses appears in the list of mail
 exchangers for a remote destination, the list is truncated to
 avoid mail delivery loops.
+See also the \fBproxy_interfaces\fR parameter.
 .IP \fBnotify_classes\fR
 When this parameter includes the \fBprotocol\fR class, send mail to the
 postmaster with transcripts of SMTP sessions with protocol errors.
+.IP \fBproxy_interfaces\fR
+Network interfaces that this mail system receives mail on by way
+of a proxy or network address translator. When any of those addresses
+appears in the list of mail exchangers for a remote destination, the
+list is truncated to avoid mail delivery loops.
+See also the \fBinet_interfaces\fR parameter.
 .IP \fBsmtp_always_send_ehlo\fR
 Always send EHLO at the start of a connection.
 .IP \fBsmtp_never_send_ehlo\fR

postfix/src/global/mail_params.c

@@ -37,6 +37,7 @@
 /*	char	*var_pid_dir;
 /*	int	var_dont_remove;
 /*	char	*var_inet_interfaces;
+/*	char	*var_proxy_interfaces;
 /*	char	*var_mynetworks;
 /*	char	*var_double_bounce_sender;
 /*	int	var_line_limit;
@@ -190,6 +191,7 @@ int     var_ipc_timeout;
 char   *var_pid_dir;
 int     var_dont_remove;
 char   *var_inet_interfaces;
+char   *var_proxy_interfaces;
 char   *var_mynetworks;
 char   *var_double_bounce_sender;
 int     var_line_limit;
@@ -439,6 +441,7 @@ void    mail_params_init()
 	VAR_QUEUE_DIR, DEF_QUEUE_DIR, &var_queue_dir, 1, 0,
 	VAR_PID_DIR, DEF_PID_DIR, &var_pid_dir, 1, 0,
 	VAR_INET_INTERFACES, DEF_INET_INTERFACES, &var_inet_interfaces, 1, 0,
+	VAR_PROXY_INTERFACES, DEF_PROXY_INTERFACES, &var_proxy_interfaces, 0, 0,
 	VAR_DOUBLE_BOUNCE, DEF_DOUBLE_BOUNCE, &var_double_bounce_sender, 1, 0,
 	VAR_DEFAULT_PRIVS, DEF_DEFAULT_PRIVS, &var_default_privs, 1, 0,
 	VAR_ALIAS_DB_MAP, DEF_ALIAS_DB_MAP, &var_alias_db_map, 0, 0,

postfix/src/global/mail_params.h

@@ -118,6 +118,10 @@ extern char *var_error_rcpt;
 #define DEF_INET_INTERFACES	"all"
 extern char *var_inet_interfaces;
 
+#define VAR_PROXY_INTERFACES	"proxy_interfaces"	/* proxies, NATs */
+#define DEF_PROXY_INTERFACES	""
+extern char *var_proxy_interfaces;
+
  /*
   * Masquerading (i.e. subdomain stripping).
   */

postfix/src/global/mail_version.h

@@ -20,7 +20,7 @@
   * Patches change the patchlevel and the release date. Snapshots change the
   * release date only, unless they include the same bugfix as a patch release.
   */
-#define MAIL_RELEASE_DATE	"20021015"
+#define MAIL_RELEASE_DATE	"20021024"
 
 #define VAR_MAIL_VERSION	"mail_version"
 #define DEF_MAIL_VERSION	"1.1.11-" MAIL_RELEASE_DATE

postfix/src/global/own_inet_addr.c

@@ -12,6 +12,11 @@
 /*	INET_ADDR_LIST *own_inet_addr_list()
 /*
 /*	INET_ADDR_LIST *own_inet_mask_list()
+/*
+/*	int	proxy_inet_addr(addr)
+/*	struct in_addr *addr;
+/*
+/*	INET_ADDR_LIST *proxy_inet_addr_list()
 /* DESCRIPTION
 /*	own_inet_addr() determines if the specified IP address belongs
 /*	to this mail system instance, i.e. if this mail system instance
@@ -22,6 +27,12 @@
 /*
 /*	own_inet_mask_list() returns the list of all corresponding
 /*	netmasks.
+/*
+/*	proxy_inet_addr() determines if the specified IP address is
+/*	listed with the proxy_interfaces configuration parameter.
+/*
+/*	proxy_inet_addr_list() returns the list of all addresses that
+/*	belong to proxy network interfaces.
 /* LICENSE
 /* .ad
 /* .fi
@@ -62,6 +73,7 @@
 
 static INET_ADDR_LIST addr_list;
 static INET_ADDR_LIST mask_list;
+static INET_ADDR_LIST proxy_list;
 
 /* own_inet_addr_init - initialize my own address list */
 
@@ -171,3 +183,58 @@ INET_ADDR_LIST *own_inet_mask_list(void)
 
     return (&mask_list);
 }
+
+/* proxy_inet_addr_init - initialize my proxy interface list */
+
+static void proxy_inet_addr_init(INET_ADDR_LIST *addr_list)
+{
+    char   *hosts;
+    char   *host;
+    char   *sep = " \t,";
+    char   *bufp;
+
+    /*
+     * Parse the proxy_interfaces parameter, and expand any symbolic
+     * hostnames into IP addresses.
+     */
+    inet_addr_list_init(addr_list);
+    bufp = hosts = mystrdup(var_proxy_interfaces);
+    while ((host = mystrtok(&bufp, sep)) != 0)
+	if (inet_addr_host(addr_list, host) == 0)
+	    msg_fatal("config variable %s: host not found: %s",
+		      VAR_PROXY_INTERFACES, host);
+    myfree(hosts);
+
+    /*
+     * Weed out duplicate IP addresses.
+     */
+    inet_addr_list_uniq(addr_list);
+}
+
+/* proxy_inet_addr - is this my proxy internet address */
+
+int     proxy_inet_addr(struct in_addr * addr)
+{
+    int     i;
+
+    if (*var_proxy_interfaces == 0)
+	return (0);
+
+    if (proxy_list.used == 0)
+	proxy_inet_addr_init(&proxy_list);
+
+    for (i = 0; i < proxy_list.used; i++)
+	if (addr->s_addr == proxy_list.addrs[i].s_addr)
+	    return (1);
+    return (0);
+}
+
+/* proxy_inet_addr_list - return list of addresses */
+
+INET_ADDR_LIST *proxy_inet_addr_list(void)
+{
+    if (*var_proxy_interfaces != 0 && proxy_list.used == 0)
+	proxy_inet_addr_init(&proxy_list);
+
+    return (&proxy_list);
+}

postfix/src/global/own_inet_addr.h

@@ -22,6 +22,8 @@
 extern int own_inet_addr(struct in_addr *);
 extern struct INET_ADDR_LIST *own_inet_addr_list(void);
 extern struct INET_ADDR_LIST *own_inet_mask_list(void);
+extern int proxy_inet_addr(struct in_addr *);
+extern struct INET_ADDR_LIST *proxy_inet_addr_list(void);
 
 /* LICENSE
 /* .ad

postfix/src/global/resolve_local.c

@@ -14,7 +14,8 @@
 /*	resolve_local() determines if the named domain resolves to the
 /*	local mail system, either by case-insensitive exact match
 /*	against the domains, files or tables listed in $mydestination,
-/*	or by any of the network addresses listed in $inet_interfaces.
+/*	or by any of the network addresses listed in $inet_interfaces
+/*	or in $proxy_interfaces.
 /*
 /*	resolve_local_init() performs initialization. If this routine is
 /*	not called explicitly ahead of time, it will be called on the fly.
@@ -118,7 +119,7 @@ int     resolve_local(const char *addr)
 	dest++;
 	dest[len -= 2] = 0;
 	if ((ipaddr.s_addr = inet_addr(dest)) != INADDR_NONE
-	    && own_inet_addr(&ipaddr))
+	    && (own_inet_addr(&ipaddr) || proxy_inet_addr(&ipaddr)))
 	    RETURN(1);
     }
 

postfix/src/smtp/smtp.c

@@ -92,9 +92,16 @@
 /*	mail on. When any of those addresses appears in the list of mail
 /*	exchangers for a remote destination, the list is truncated to
 /*	avoid mail delivery loops.
+/*	See also the \fBproxy_interfaces\fR parameter.
 /* .IP \fBnotify_classes\fR
 /*	When this parameter includes the \fBprotocol\fR class, send mail to the
 /*	postmaster with transcripts of SMTP sessions with protocol errors.
+/* .IP \fBproxy_interfaces\fR
+/*	Network interfaces that this mail system receives mail on by way
+/*	of a proxy or network address translator. When any of those addresses
+/*	appears in the list of mail exchangers for a remote destination, the
+/*	list is truncated to avoid mail delivery loops.
+/*	See also the \fBinet_interfaces\fR parameter.
 /* .IP \fBsmtp_always_send_ehlo\fR
 /*	Always send EHLO at the start of a connection.
 /* .IP \fBsmtp_never_send_ehlo\fR

postfix/src/smtp/smtp_addr.c

@@ -268,6 +268,19 @@ static DNS_RR *smtp_find_self(DNS_RR *addr_list)
 	    }
     }
 
+    /*
+     * Find out if this mail system has a proxy listening on this address.
+     */
+    self = proxy_inet_addr_list();
+    for (addr = addr_list; addr; addr = addr->next) {
+	for (i = 0; i < self->used; i++)
+	    if (INADDRP(addr->data)->s_addr == self->addrs[i].s_addr) {
+		if (msg_verbose)
+		    msg_info("%s: found at pref %d", myname, addr->pref);
+		return (addr);
+	    }
+    }
+
     /*
      * Didn't find myself.
      */

postfix/src/smtpd/smtpd_check.c

@@ -1388,6 +1388,8 @@ static int has_my_addr(SMTPD_STATE *state, const char *host,
 	    msg_info("%s: addr %s", myname, inet_ntoa(addr));
 	if (own_inet_addr(&addr))
 	    return (YUP);
+	if (proxy_inet_addr(&addr))
+	    return (YUP);
     }
     if (msg_verbose)
 	msg_info("%s: host %s: no match", myname, host);