X-Git-Url: https://git.distorted.org.uk/~mdw/exim-config/blobdiff_plain/185b5456076ca86959643ce2f19c98c0f82f281e..7c43ea06b0694c3a1f50cb1ef17f48271f28b8ce:/exchange.m4

diff --git a/exchange.m4 b/exchange.m4
index 08fe4a0..b4cb02b 100644
--- a/exchange.m4
+++ b/exchange.m4
@@ -24,17 +24,8 @@
 ###--------------------------------------------------------------------------
 ### Listen for incoming connections.
 
-SECTION(global, tls)m4_dnl
-tls_certificate = CONF_sysconf_dir/server.cert
-tls_privatekey = CONF_sysconf_dir/server.key
-tls_advertise_hosts = *
-tls_dhparam = CONF_ca_dir/dh-param.pem
-tls_require_ciphers = ${if or {{={$received_port}{CONF_submission_port}} \
-			       {match_ip {$sender_host_address}{+trusted}}} \
-			   {CONF_good_ciphers} \
-			   {CONF_acceptable_ciphers}}
-tls_verify_certificates = CONF_ca_dir/ca.cert
-tls_verify_hosts = ${if eq{$acl_c_mode}{submission} {} {+allnets}}
+SECTION(global, daemon)m4_dnl
+daemon_smtp_ports = CONF_smtp_port : CONF_submission_port
 
 DIVERT(null)
 ###--------------------------------------------------------------------------
@@ -44,38 +35,66 @@ SECTION(acl, mail-hooks)m4_dnl
 	## Check that a submitted message's sender address is allowable.
 	require	 acl = mail_client_addr
 
-	## Insist that a local client connect through TLS.
-	deny	 message = Hosts within CONF_master_domain must use TLS
-		!condition = ${if eq{$acl_c_mode}{submission}}
-		 hosts = +allnets
-		!encrypted = *
-
 SECTION(acl, misc)m4_dnl
 mail_client_addr:
 
 	## If this is a message submission then that's handled elsewhere.
 	accept	 condition = ${if eq{$acl_c_mode}{submission}}
 
-	## Make sure that the sender matches the client address.
-	require	 message = Client host invalid for sender domain
-		 hosts = ${LOOKUP_DOMAIN($sender_address_domain,
+	## Make sure that the sender matches the client address.  I feel like
+	## I want to reject these, but that will break stuff.  For example,
+	## if I send mail to an externally hosted address which is really a
+	## distribution list containing some local address, then we'll
+	## (approximately legitimately) receive mail with an apparently-local
+	## sender from a remote host.
+	warn	!hosts = ${LOOKUP_DOMAIN($sender_address_domain,
 			   {KV(hosts, {$value}{+allnets})},
 			   {${if match_domain {$sender_address_domain} \
 					      {+public} \
 				 {+allnets}{! +allnets}}})}
+		  WARNING_HEADER(RCLNTLSNDR,
+				 <:Apparently local sender, but received from remote \
+				   server.\n\t\
+				   sender=$sender_address \
+				   host=$sender_host_address:>)
 
 	## OK.
 	accept
 
 DIVERT(null)
 ###--------------------------------------------------------------------------
+### Rename locally-meaningful headers in mail from outside.
+
+m4_define(<:DISTORTED_HEADERS:>,
+<:X-CONF_header_token-SpamAssassin-Score,
+X-CONF_header_token-SpamAssassin-Status:>)
+
+SECTION(acl, data)m4_dnl
+	## If this message is coming from outside then rename headers which
+	## look like the ones we're likely to add.  This is most relevant for
+	## our spam-report headers, because I'm not sure I understand why
+	## someone would want to fake an X-Distorted-Warning header.
+	warn	!condition = ${if eq{$acl_c_mode}{submission}}
+		!hosts = +allnets
+		 set acl_m_hdradd = ${if def:acl_m_hdradd{$acl_m_hdradd}}\
+			RENAME_HEADERS_ADD(<:DISTORTED_HEADERS:>)
+		 set acl_m_hdrrm = ${if def:acl_m_hdrrm{$acl_m_hdrrm:}}\
+			RENAME_HEADERS_REMOVE(<:DISTORTED_HEADERS:>)
+
+DIVERT(null)
+###--------------------------------------------------------------------------
 ### The obvious trivial router.
 
 SECTION(routers, remote)m4_dnl
 ## Send mail on to a host in our own network.  We must apply extra security.
 local:
 	driver = dnslookup
-	domains = ! +known : *.CONF_master_domain
+	domains = ${if bool {${LOOKUP_DOMAIN($domain,
+			       {KV(service, {$value}{true})},
+			       {false})}} \
+		       {}{ ! +public : \
+			   CONF_master_domain : \
+			   *.CONF_master_domain }}
 	self = fail
 	transport = smtp_local
 	no_more
@@ -83,7 +102,10 @@ local:
 ## Send mail on to unknown hosts.
 remote:
 	driver = dnslookup
-	domains = ! +known
+	domains = ${if bool {${LOOKUP_DOMAIN($domain,
+			       {KV(service, {$value}{true})},
+			       {false})}} \
+		       {}{ ! +public }}
 	self = fail
 	transport = smtp
 	no_more