bridge link: add support to specify master

This patch adds support to specify 'master' keyword,
to target a bridge link command explicitly to the software
bridge driver.

Adds self/master keywords to usage and man page

v2:
	fix usage to say (self and master) and not (self or master)
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>

bridge/link.c

@@ -227,6 +227,7 @@ static void usage(void)
 	fprintf(stderr,	"                               [ learning_sync {on | off} ]\n");
 	fprintf(stderr,	"                               [ flood {on | off} ]\n");
 	fprintf(stderr, "                               [ hwmode {vepa | veb} ]\n");
+	fprintf(stderr, "                               [ self ] [ master ]\n");
 	fprintf(stderr, "       bridge link show [dev DEV]\n");
 	exit(-1);
 }
@@ -343,7 +344,9 @@ static int brlink_modify(int argc, char **argv)
 				exit(-1);
 			}
 		} else if (strcmp(*argv, "self") == 0) {
-			flags = BRIDGE_FLAGS_SELF;
+			flags |= BRIDGE_FLAGS_SELF;
+		} else if (strcmp(*argv, "master") == 0) {
+			flags |= BRIDGE_FLAGS_MASTER;
 		} else {
 			usage();
 		}

man/man8/bridge.8

@@ -40,7 +40,8 @@ bridge \- show / manipulate bridge addresses and devices
 .BR learning " { " on " | " off " } ] [ "
 .BR learning_sync " { " on " | " off " } ] [ "
 .BR flood " { " on " | " off " } ] [ "
-.BR hwmode " { " vepa " | " veb " } ] "
+.BR hwmode " { " vepa " | " veb " } ] [ "
+.BR self " ]  [ " master " ] "
 
 .ti -8
 .BR "bridge link" " [ " show " ] [ "
@@ -286,6 +287,15 @@ switch.
 .B veb
 - bridging happens in hardware.
 
+.TP
+.BI self
+link setting is configured on specified physical device
+
+.TP
+.BI master
+link setting is configured on the software bridge (default)
+
+
 .SS bridge link show - list bridge port configuration.
 
 This command displays the current bridge port configuration and flags.