ovs-vsctl: Allow "fake bridges" to be created for VLAN 0.

A fake bridge for VLAN 0 is useful, because it provides a way to create
access ports for VLAN 0.  There is no good reason to prevent it.

NIC-464.
Reported-by: Rob Hoes <Rob.Hoes@citrix.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

3 files changed, 52 insertions, 38 deletions

diff --git a/tests/ovs-vsctl.at b/tests/ovs-vsctl.at
index 8ade1727..dfacbf8a 100644
--- a/tests/ovs-vsctl.at
+++ b/tests/ovs-vsctl.at
@@ -401,8 +401,7 @@ OVS_VSCTL_CLEANUP
 AT_CLEANUP
 
 dnl ----------------------------------------------------------------------
-AT_BANNER([ovs-vsctl unit tests -- fake bridges])
-
+dnl OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF([VLAN])
 m4_define([OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF],
   [AT_CHECK(
      [RUN_OVS_VSCTL(
@@ -410,36 +409,40 @@ m4_define([OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF],
         [--may-exist add-br xenbr0],
         [add-port xenbr0 eth0],
         [--may-exist add-port xenbr0 eth0],
-        [add-br xapi1 xenbr0 9],
-        [--may-exist add-br xapi1 xenbr0 9],
-        [add-port xapi1 eth0.9])],
+        [add-br xapi1 xenbr0 $1],
+        [--may-exist add-br xapi1 xenbr0 $1],
+        [add-port xapi1 eth0.$1])],
      [0], [], [], [OVS_VSCTL_CLEANUP])])
 
-AT_SETUP([simple fake bridge])
+dnl OVS_VSCTL_FAKE_BRIDGE_TESTS([VLAN])
+m4_define([OVS_VSCTL_FAKE_BRIDGE_TESTS], [
+AT_BANNER([ovs-vsctl unit tests -- fake bridges (VLAN $1)])
+
+AT_SETUP([simple fake bridge (VLAN $1)])
 AT_KEYWORDS([ovs-vsctl fake-bridge])
 OVS_VSCTL_SETUP
-OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF
+OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF([$1])
 AT_CHECK([RUN_OVS_VSCTL([--may-exist add-br xapi1])], [1], [],
-  [ovs-vsctl: "--may-exist add-br xapi1" but xapi1 is a VLAN bridge for VLAN 9
+  [ovs-vsctl: "--may-exist add-br xapi1" but xapi1 is a VLAN bridge for VLAN $1
 ], [OVS_VSCTL_CLEANUP])
-AT_CHECK([RUN_OVS_VSCTL([--may-exist add-br xapi1 xxx 9])], [1], [],
-  [ovs-vsctl: "--may-exist add-br xapi1 xxx 9" but xapi1 has the wrong parent xenbr0
+AT_CHECK([RUN_OVS_VSCTL([--may-exist add-br xapi1 xxx $1])], [1], [],
+  [ovs-vsctl: "--may-exist add-br xapi1 xxx $1" but xapi1 has the wrong parent xenbr0
 ], [OVS_VSCTL_CLEANUP])
 AT_CHECK([RUN_OVS_VSCTL([--may-exist add-br xapi1 xenbr0 10])], [1], [],
-  [ovs-vsctl: "--may-exist add-br xapi1 xenbr0 10" but xapi1 is a VLAN bridge for the wrong VLAN 9
+  [ovs-vsctl: "--may-exist add-br xapi1 xenbr0 10" but xapi1 is a VLAN bridge for the wrong VLAN $1
 ], [OVS_VSCTL_CLEANUP])
-CHECK_BRIDGES([xapi1, xenbr0, 9], [xenbr0, xenbr0, 0])
+CHECK_BRIDGES([xapi1, xenbr0, $1], [xenbr0, xenbr0, 0])
 CHECK_PORTS([xenbr0], [eth0])
 CHECK_IFACES([xenbr0], [eth0])
-CHECK_PORTS([xapi1], [eth0.9])
-CHECK_IFACES([xapi1], [eth0.9])
+CHECK_PORTS([xapi1], [eth0.$1])
+CHECK_IFACES([xapi1], [eth0.$1])
 OVS_VSCTL_CLEANUP
 AT_CLEANUP
 
-AT_SETUP([simple fake bridge + del-br fake bridge])
+AT_SETUP([simple fake bridge + del-br fake bridge (VLAN $1)])
 AT_KEYWORDS([ovs-vsctl fake-bridge])
 OVS_VSCTL_SETUP
-OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF
+OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF([$1])
 AT_CHECK([RUN_OVS_VSCTL([del-br xapi1])], [0], [], [], [OVS_VSCTL_CLEANUP])
 CHECK_BRIDGES([xenbr0, xenbr0, 0])
 CHECK_PORTS([xenbr0], [eth0])
@@ -447,19 +450,19 @@ CHECK_IFACES([xenbr0], [eth0])
 OVS_VSCTL_CLEANUP
 AT_CLEANUP
 
-AT_SETUP([simple fake bridge + del-br real bridge])
+AT_SETUP([simple fake bridge + del-br real bridge (VLAN $1)])
 AT_KEYWORDS([ovs-vsctl fake-bridge])
 OVS_VSCTL_SETUP
-OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF
+OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF([$1])
 AT_CHECK([RUN_OVS_VSCTL([del-br xenbr0])], [0], [], [], [OVS_VSCTL_CLEANUP])
 CHECK_BRIDGES
 OVS_VSCTL_CLEANUP
 AT_CLEANUP
 
-AT_SETUP([simple fake bridge + external IDs])
+AT_SETUP([simple fake bridge + external IDs (VLAN $1)])
 AT_KEYWORDS([ovs-vsctl fake-bridge])
 OVS_VSCTL_SETUP
-OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF
+OVS_VSCTL_SETUP_SIMPLE_FAKE_CONF([$1])
 AT_CHECK([RUN_OVS_VSCTL_TOGETHER(
   [br-set-external-id xenbr0 key0 value0],
   [br-set-external-id xapi1 key1 value1],
@@ -473,27 +476,32 @@ value0
 key1=value1
 value1
 ], [], [OVS_VSCTL_CLEANUP])
-CHECK_BRIDGES([xapi1, xenbr0, 9], [xenbr0, xenbr0, 0])
+CHECK_BRIDGES([xapi1, xenbr0, $1], [xenbr0, xenbr0, 0])
 CHECK_PORTS([xenbr0], [eth0])
 CHECK_IFACES([xenbr0], [eth0])
-CHECK_PORTS([xapi1], [eth0.9])
-CHECK_IFACES([xapi1], [eth0.9])
+CHECK_PORTS([xapi1], [eth0.$1])
+CHECK_IFACES([xapi1], [eth0.$1])
 OVS_VSCTL_CLEANUP
 AT_CLEANUP
+]) # OVS_VSCTL_FAKE_BRIDGE_TESTS
+
+OVS_VSCTL_FAKE_BRIDGE_TESTS([9])
+OVS_VSCTL_FAKE_BRIDGE_TESTS([0])
 
+dnl OVS_VSCTL_SETUP_BOND_FAKE_CONF([VLAN])
 m4_define([OVS_VSCTL_SETUP_BOND_FAKE_CONF],
   [AT_CHECK(
      [RUN_OVS_VSCTL(
         [add-br xapi1],
         [add-bond xapi1 bond0 eth0 eth1],
-        [add-br xapi2 xapi1 11],
-        [add-port xapi2 bond0.11])],
+        [add-br xapi2 xapi1 $1],
+        [add-port xapi2 bond0.$1])],
      [0], [], [], [OVS_VSCTL_CLEANUP])])
 
 AT_SETUP([fake bridge on bond])
 AT_KEYWORDS([ovs-vsctl fake-bridge])
 OVS_VSCTL_SETUP
-OVS_VSCTL_SETUP_BOND_FAKE_CONF
+OVS_VSCTL_SETUP_BOND_FAKE_CONF([11])
 CHECK_BRIDGES([xapi1, xapi1, 0], [xapi2, xapi1, 11])
 CHECK_PORTS([xapi1], [bond0])
 CHECK_IFACES([xapi1], [eth0], [eth1])
@@ -505,7 +513,7 @@ AT_CLEANUP
 AT_SETUP([fake bridge on bond + del-br fake bridge])
 AT_KEYWORDS([ovs-vsctl fake-bridge])
 OVS_VSCTL_SETUP
-OVS_VSCTL_SETUP_BOND_FAKE_CONF
+OVS_VSCTL_SETUP_BOND_FAKE_CONF([11])
 AT_CHECK([RUN_OVS_VSCTL_ONELINE([del-br xapi2])], [0], [
 ], [], [OVS_VSCTL_CLEANUP])
 CHECK_BRIDGES([xapi1, xapi1, 0])
@@ -517,7 +525,7 @@ AT_CLEANUP
 AT_SETUP([fake bridge on bond + del-br real bridge])
 AT_KEYWORDS([ovs-vsctl fake-bridge])
 OVS_VSCTL_SETUP
-OVS_VSCTL_SETUP_BOND_FAKE_CONF
+OVS_VSCTL_SETUP_BOND_FAKE_CONF([11])
 AT_CHECK([RUN_OVS_VSCTL([del-br xapi1])])
 CHECK_BRIDGES
 OVS_VSCTL_CLEANUP
diff --git a/utilities/ovs-vsctl.8.in b/utilities/ovs-vsctl.8.in
index a4a67662..0e7ab775 100644
--- a/utilities/ovs-vsctl.8.in
+++ b/utilities/ovs-vsctl.8.in
@@ -69,7 +69,8 @@ When such a ``fake bridge'' is active, \fBovs\-vsctl\fR will treat it
 much like a bridge separate from its ``parent bridge,'' but the actual
 implementation in Open vSwitch uses only a single bridge, with ports on
 the fake bridge assigned the implicit VLAN of the fake bridge of which
-they are members.
+they are members.  (A fake bridge for VLAN 0 receives packets that
+have no 802.1Q tag or a tag with VLAN 0.)
 .
 .SH OPTIONS
 .
@@ -179,7 +180,7 @@ nothing if \fIbridge\fR already exists as a real bridge.
 Creates a ``fake bridge'' named \fIbridge\fR within the existing Open
 vSwitch bridge \fIparent\fR, which must already exist and must not
 itself be a fake bridge.  The new fake bridge will be on 802.1Q VLAN
-\fIvlan\fR, which must be an integer between 1 and 4095.  Initially
+\fIvlan\fR, which must be an integer between 0 and 4095.  Initially
 \fIbridge\fR will have no ports (other than \fIbridge\fR itself).
 .IP
 Without \fB\-\-may\-exist\fR, attempting to create a bridge that
diff --git a/utilities/ovs-vsctl.c b/utilities/ovs-vsctl.c
index a2af2f66..275c2a9a 100644
--- a/utilities/ovs-vsctl.c
+++ b/utilities/ovs-vsctl.c
@@ -612,8 +612,13 @@ struct vsctl_bridge {
     struct ovsrec_controller **ctrl;
     char *fail_mode;
     size_t n_ctrl;
-    struct vsctl_bridge *parent;
-    int vlan;
+
+    /* VLAN ("fake") bridge support.
+     *
+     * Use 'parent != NULL' to detect a fake bridge, because 'vlan' can be 0
+     * in either case. */
+    struct vsctl_bridge *parent; /* Real bridge, or NULL. */
+    int vlan;                    /* VLAN VID (0...4095), or 0. */
 };
 
 struct vsctl_port {
@@ -704,7 +709,7 @@ port_is_fake_bridge(const struct ovsrec_port *port_cfg)
 {
     return (port_cfg->fake_bridge
             && port_cfg->tag
-            && *port_cfg->tag >= 1 && *port_cfg->tag <= 4095);
+            && *port_cfg->tag >= 0 && *port_cfg->tag <= 4095);
 }
 
 static struct vsctl_bridge *
@@ -841,7 +846,7 @@ get_info(struct vsctl_context *ctx, struct vsctl_info *info)
             port = xmalloc(sizeof *port);
             port->port_cfg = port_cfg;
             if (port_cfg->tag
-                && *port_cfg->tag >= 1 && *port_cfg->tag <= 4095) {
+                && *port_cfg->tag >= 0 && *port_cfg->tag <= 4095) {
                 port->bridge = find_vlan_bridge(info, br, *port_cfg->tag);
                 if (!port->bridge) {
                     port->bridge = br;
@@ -1329,8 +1334,8 @@ cmd_add_br(struct vsctl_context *ctx)
     } else if (ctx->argc == 4) {
         parent_name = ctx->argv[2];
         vlan = atoi(ctx->argv[3]);
-        if (vlan < 1 || vlan > 4095) {
-            vsctl_fatal("%s: vlan must be between 1 and 4095", ctx->argv[0]);
+        if (vlan < 0 || vlan > 4095) {
+            vsctl_fatal("%s: vlan must be between 0 and 4095", ctx->argv[0]);
         }
     } else {
         vsctl_fatal("'%s' command takes exactly 1 or 3 arguments",
@@ -1397,7 +1402,7 @@ cmd_add_br(struct vsctl_context *ctx)
         int64_t tag = vlan;
 
         parent = find_bridge(&info, parent_name, false);
-        if (parent && parent->vlan) {
+        if (parent && parent->parent) {
             vsctl_fatal("cannot create bridge with fake bridge as parent");
         }
         if (!parent) {
@@ -1750,7 +1755,7 @@ add_port(struct vsctl_context *ctx,
     ovsrec_port_set_bond_fake_iface(port, fake_iface);
     free(ifaces);
 
-    if (bridge->vlan) {
+    if (bridge->parent) {
         int64_t tag = bridge->vlan;
         ovsrec_port_set_tag(port, &tag, 1);
     }