[PATCH] s3: Add "spoolss backchannel" parameter

[Volker Lendecke]

---
 .../smbdotconf/printing/spoolssbackchannel.xml     |   16 ++++++++++++++++
 source3/include/proto.h                            |    1 +
 source3/param/loadparm.c                           |   12 ++++++++++++
 source3/rpc_server/spoolss/srv_spoolss_nt.c        |    6 ++++++
 4 files changed, 35 insertions(+), 0 deletions(-)
 create mode 100644 docs-xml/smbdotconf/printing/spoolssbackchannel.xml

diff --git a/docs-xml/smbdotconf/printing/spoolssbackchannel.xml b/docs-xml/smbdotconf/printing/spoolssbackchannel.xml
new file mode 100644
index 0000000..dc168fe
--- /dev/null
+++ b/docs-xml/smbdotconf/printing/spoolssbackchannel.xml
@@ -0,0 +1,16 @@
+<samba:parameter name="spoolss backchannel"
+                 context="S"
+				 print="1"
+				 type="boolean"
+                 xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
+<synonym>print ok</synonym>
+<description>
+  <para>Windows print clients often demand that the server opens
+    connections back to them. Due to firewall settings this can cause
+    considerable timeouts. By setting this parameter to
+    <constant>no</constant> the Samba print server will not even try
+    to connect to clients and treat corresponding requests as if the
+    connection back to the client failed.
+</description>
+<value type="default">yes</value>
+</samba:parameter>
diff --git a/source3/include/proto.h b/source3/include/proto.h
index 78965de..f58fb12 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -3200,6 +3200,7 @@ bool lp_guest_ok(int );
 bool lp_guest_only(int );
 bool lp_administrative_share(int );
 bool lp_print_ok(int );
+bool lp_spoolss_backchannel(int );
 bool lp_map_hidden(int );
 bool lp_map_archive(int );
 bool lp_store_dos_attributes(int );
diff --git a/source3/param/loadparm.c b/source3/param/loadparm.c
index 3314ad2..7ca5543 100644
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -474,6 +474,7 @@ struct service {
 	bool bAdministrative_share;
 	bool bGuest_ok;
 	bool bPrint_ok;
+	bool bSpoolssBackchannel;
 	bool bMap_system;
 	bool bMap_hidden;
 	bool bMap_archive;
@@ -618,6 +619,7 @@ static struct service sDefault = {
 	False,			/* bAdministrative_share */
 	False,			/* bGuest_ok */
 	False,			/* bPrint_ok */
+	True,			/* bSpoolssBackchannel */
 	False,			/* bMap_system */
 	False,			/* bMap_hidden */
 	True,			/* bMap_archive */
@@ -2722,6 +2724,15 @@ static struct parm_struct parm_table[] = {
 		.flags		= FLAG_HIDE,
 	},
 	{
+		.label		= "spoolss backchannel",
+		.type		= P_BOOL,
+		.p_class	= P_LOCAL,
+		.ptr		= &sDefault.bSpoolssBackchannel,
+		.special	= NULL,
+		.enum_list	= NULL,
+		.flags		= FLAG_ADVANCED,
+	},
+	{
 		.label		= "printing",
 		.type		= P_ENUM,
 		.p_class	= P_LOCAL,
@@ -5918,6 +5929,7 @@ FN_LOCAL_BOOL(lp_guest_ok, bGuest_ok)
 FN_LOCAL_BOOL(lp_guest_only, bGuest_only)
 FN_LOCAL_BOOL(lp_administrative_share, bAdministrative_share)
 FN_LOCAL_BOOL(lp_print_ok, bPrint_ok)
+FN_LOCAL_BOOL(lp_spoolss_backchannel, bSpoolssBackchannel)
 FN_LOCAL_BOOL(lp_map_hidden, bMap_hidden)
 FN_LOCAL_BOOL(lp_map_archive, bMap_archive)
 FN_LOCAL_BOOL(lp_store_dos_attributes, bStoreDosAttributes)
diff --git a/source3/rpc_server/spoolss/srv_spoolss_nt.c b/source3/rpc_server/spoolss/srv_spoolss_nt.c
index 3026a88..3a5b060 100644
--- a/source3/rpc_server/spoolss/srv_spoolss_nt.c
+++ b/source3/rpc_server/spoolss/srv_spoolss_nt.c
@@ -2736,6 +2736,12 @@ WERROR _spoolss_RemoteFindFirstPrinterChangeNotifyEx(struct pipes_struct *p,
 	DEBUG(10,("_spoolss_RemoteFindFirstPrinterChangeNotifyEx: "
 		"client_address is %s\n", p->client_id->addr));
 
+	if (!lp_spoolss_backchannel(snum)) {
+		DEBUG(10, ("_spoolss_RemoteFindFirstPrinterChangeNotifyEx: "
+			   "backchannel disabled\n"));
+		return WERR_SERVER_UNAVAILABLE;
+	}
+
 	if (!interpret_string_addr(&client_ss, p->client_id->addr,
 				   AI_NUMERICHOST)) {
 		return WERR_SERVER_UNAVAILABLE;
-- 
1.7.0.4