[PATCH iproute2 3/3] ip link: Config and display device proto_down bits.

@@ -66,6 +66,8 @@
  * @IFF_LOWER_UP: driver signals L1 up. Volatile.
  * @IFF_DORMANT: driver signals dormant. Volatile.
  * @IFF_ECHO: echo sent packets. Volatile.
+ * @IFF_PROTO_DOWN: protocol is down on the interface. Userspace can toggle
+ *	this by toggling the net_device proto_down bits. Volatile.
  */
 enum net_device_flags {
 	IFF_UP				= 1<<0,  /* sysfs */

@@ -87,6 +89,7 @@ enum net_device_flags {
 	IFF_LOWER_UP			= 1<<16, /* __volatile__ */
 	IFF_DORMANT			= 1<<17, /* __volatile__ */
 	IFF_ECHO			= 1<<18, /* __volatile__ */
+	IFF_PROTO_DOWN			= 1<<19, /* __volatile__ */
 };
 
 #define IFF_UP				IFF_UP

@@ -108,9 +111,11 @@ enum net_device_flags {
 #define IFF_LOWER_UP			IFF_LOWER_UP
 #define IFF_DORMANT			IFF_DORMANT
 #define IFF_ECHO			IFF_ECHO
+#define IFF_PROTO_DOWN			IFF_PROTO_DOWN
 
 #define IFF_VOLATILE	(IFF_LOOPBACK|IFF_POINTOPOINT|IFF_BROADCAST|IFF_ECHO|\
-		IFF_MASTER|IFF_SLAVE|IFF_RUNNING|IFF_LOWER_UP|IFF_DORMANT)
+		IFF_MASTER|IFF_SLAVE|IFF_RUNNING|IFF_LOWER_UP|IFF_DORMANT|\
+		IFF_PROTO_DOWN)
 
 #define IF_GET_IFACE	0x0001		/* for querying only */
 #define IF_GET_PROTO	0x0002

@@ -156,6 +161,28 @@ enum {
 	IF_LINK_MODE_DORMANT,	/* limit upward transition to dormant */
 };
 
+/**
+ * enum net_device_proto_down - &struct net_device proto_down
+ *
+ * These are the &struct net_device proto_down bits and define a list of
+ * protocols that could hold the device in a IFF_PROTO_DOWN state. Setting of
+ * these bits is triggered by userspace. Userspace can query and set these
+ * flags using userspace utilities. There is also a sysfs entry available
+ * which can only be queried. The sysfs entries are available via
+ * /sys/class/net/<dev>/proto_down
+ *
+ *
+ * @IF_LINK_PROTO_DOWN_MLAG: proto_down by a multi-chassis LAG application.
+ * @IF_LINK_PROTO_DOWN_STP: proto_down by an STP application.
+ */
+enum net_device_proto_down {
+	IF_LINK_PROTO_DOWN_MLAG		= 1<<0,
+	IF_LINK_PROTO_DOWN_STP		= 1<<1,
+};
+
+#define IF_LINK_PROTO_DOWN_MLAG		IF_LINK_PROTO_DOWN_MLAG
+#define IF_LINK_PROTO_DOWN_STP		IF_LINK_PROTO_DOWN_STP
+
 /*
  *	Device mapping structure. I'd just gone off and designed a 
  *	beautiful scheme using only loadable modules with arguments

@@ -80,6 +80,13 @@ struct rtnl_link_ifmap {
 	__u8	port;
 };
 
+/* link protodown */
+struct rtnl_link_protodown {
+	__u32	proto_down;		/* Bitmap of protocols that want
+					 * to hold the device down */
+	__u32	proto_down_change;	/* Change mask for proto_down */
+};
+
 /*
  * IFLA_AF_SPEC
  *   Contains nested attributes for address family specific attributes.

@@ -147,6 +154,8 @@ enum {
 	IFLA_CARRIER_CHANGES,
 	IFLA_PHYS_SWITCH_ID,
 	IFLA_LINK_NETNSID,
+	IFLA_LINKPROTODOWN,	/* Bitmap of protocols that want to
+				 * hold the device down */
 	__IFLA_MAX
 };
 

@@ -119,6 +119,7 @@ static void print_link_flags(FILE *fp, unsigned flags, unsigned mdown)
 	_PF(LOWER_UP);
 	_PF(DORMANT);
 	_PF(ECHO);
+	_PF(PROTO_DOWN);
 #undef _PF
 	if (flags)
 		fprintf(fp, "%x", flags);

@@ -203,6 +204,26 @@ static char *parse_link_kind(struct rtattr *tb)
 	return "";
 }
 
+static void print_linkprotodown(FILE *fp,
+		struct rtnl_link_protodown *link_proto_down)
+{
+	unsigned int proto_down = link_proto_down->proto_down;
+
+	if (!proto_down)
+		return;
+
+	fprintf(fp, "protodown <");
+#define _PDNF(f) if (proto_down&IF_LINK_PROTO_DOWN_##f) { \
+		     proto_down &= ~IF_LINK_PROTO_DOWN_##f ; \
+		     fprintf(fp, #f "%s", proto_down ? "," : ""); }
+	_PDNF(MLAG);
+	_PDNF(STP);
+#undef _PDNF
+	if (proto_down)
+		fprintf(fp, "%x", proto_down);
+	fprintf(fp, "> ");
+}
+
 static void print_linktype(FILE *fp, struct rtattr *tb)
 {
 	struct rtattr *linkinfo[IFLA_INFO_MAX+1];

@@ -657,6 +678,9 @@ int print_linkinfo(const struct sockaddr_nl *who,
 		fprintf(fp, "group %s ", rtnl_group_n2a(group, b1, sizeof(b1)));
 	}
 
+	if (do_link && tb[IFLA_LINKPROTODOWN])
+		print_linkprotodown(fp, RTA_DATA(tb[IFLA_LINKPROTODOWN]));
+
 	if (filter.showqueue)
 		print_queuelen(fp, tb);
 

@@ -72,6 +72,7 @@ void iplink_usage(void)
 	fprintf(stderr, "	                  [ mtu MTU ]\n");
 	fprintf(stderr, "	                  [ netns PID ]\n");
 	fprintf(stderr, "	                  [ netns NAME ]\n");
+	fprintf(stderr, "	                  [ protodown PROTODOWNTYPE { on | off } ]\n");
 	fprintf(stderr, "                         [ link-netnsid ID ]\n");
 	fprintf(stderr, "			  [ alias NAME ]\n");
 	fprintf(stderr, "	                  [ vf NUM [ mac LLADDR ]\n");

@@ -94,6 +95,7 @@ void iplink_usage(void)
 		fprintf(stderr, "          gre | gretap | ip6gre | ip6gretap | vti | nlmon |\n");
 		fprintf(stderr, "          bond_slave | ipvlan }\n");
 	}
+	fprintf(stderr, "PROTODOWNTYPE := { mlag | stp }\n");
 	exit(-1);
 }
 

@@ -175,6 +177,30 @@ static int get_addr_gen_mode(const char *mode)
 	return -1;
 }
 
+static int get_link_proto_down_type(const char *type)
+{
+	if (matches(type, "mlag") == 0)
+		return IF_LINK_PROTO_DOWN_MLAG;
+	if (matches(type, "stp") == 0)
+		return IF_LINK_PROTO_DOWN_STP;
+	return 0;
+}
+
+static int fill_link_proto_down_value(
+		struct rtnl_link_protodown *link_proto_down, char *set_type)
+{
+	if (matches(set_type, "on") == 0) {
+		link_proto_down->proto_down =
+			link_proto_down->proto_down_change;
+		return 0;
+	}
+	if (matches(set_type, "off") == 0) {
+		link_proto_down->proto_down = 0;
+		return 0;
+	}
+	return -1;
+}
+
 #if IPLINK_IOCTL_COMPAT
 static int have_rtnl_newlink = -1;
 

@@ -554,6 +580,28 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req,
 			if (mode < 0)
 				invarg("Invalid link mode\n", *argv);
 			addattr8(&req->n, sizeof(*req), IFLA_LINKMODE, mode);
+		} else if (strcmp(*argv, "protodown") == 0) {
+			struct rtnl_link_protodown link_proto_down;
+			char proto_down_str[64];
+
+			NEXT_ARG();
+			link_proto_down.proto_down_change =
+					get_link_proto_down_type(*argv);
+			if (!link_proto_down.proto_down_change)
+				invarg("Invalid \"protodown\" value\n", *argv);
+			sprintf(proto_down_str, "protodown %s", *argv);
+			if (NEXT_ARG_OK()) {
+				NEXT_ARG();
+				if (fill_link_proto_down_value(
+					&link_proto_down, *argv) < 0){
+					return on_off(proto_down_str, *argv);
+				}
+				addattr_l(&req->n, sizeof(*req),
+					  IFLA_LINKPROTODOWN, &link_proto_down,
+					  sizeof(link_proto_down));
+			} else {
+				return on_off(proto_down_str, *argv);
+			}
 		} else if (strcmp(*argv, "state") == 0) {
 			int state;
 			NEXT_ARG();

@@ -113,6 +113,9 @@ ip-link \- network device configuration
 .B  netns
 .IR NETNSNAME " |"
 .br
+.BI "protodown " PROTODOWNTYPE
+.RB  "{ " on " | " off " } |"
+.br
 .B alias
 .IR NAME  " |"
 .br

@@ -687,6 +690,14 @@ tool can be used. But it allows to change network namespace only for physical de
 .IR PID .
 
 .TP
+.BI "protodown " PROTODOWNTYPE " on|off"
+protodown the device for a specific protocol type
+
+.IR PROTODOWNTYPE " := [ "
+.BR mlag " | "
+.BR stp " ]"
+
+.TP
 .BI alias " NAME"
 give the device a symbolic name for easy reference.