bridge: Add support for setting bridge port attributes

Add netlink support bridge port attributes such as cost, priority, state
and flags.  This also adds support for HW mode such as VEPA or VEB.

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>

bridge/br_common.h

@@ -10,6 +10,7 @@ extern int do_fdb(int argc, char **argv);
 extern int do_mdb(int argc, char **argv);
 extern int do_monitor(int argc, char **argv);
 extern int do_vlan(int argc, char **argv);
+extern int do_link(int argc, char **argv);
 
 extern int preferred_family;
 extern int show_stats;

bridge/bridge.c

@@ -27,7 +27,7 @@ static void usage(void)
 {
 	fprintf(stderr,
 "Usage: bridge [ OPTIONS ] OBJECT { COMMAND | help }\n"
-"where  OBJECT := { fdb | mdb | vlan | monitor }\n"
+"where  OBJECT := { link | fdb | mdb | vlan | monitor }\n"
 "       OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails]\n" );
 	exit(-1);
 }
@@ -42,6 +42,7 @@ static const struct cmd {
 	const char *cmd;
 	int (*func)(int argc, char **argv);
 } cmds[] = {
+	{ "link", 	do_link },
 	{ "fdb", 	do_fdb },
 	{ "mdb", 	do_mdb },
 	{ "vlan",	do_vlan },

bridge/link.c

@@ -9,10 +9,14 @@
 #include <linux/if.h>
 #include <linux/if_bridge.h>
 #include <string.h>
+#include <stdbool.h>
 
+#include "libnetlink.h"
 #include "utils.h"
 #include "br_common.h"
 
+unsigned int filter_index;
+
 static const char *port_states[] = {
 	[BR_STATE_DISABLED] = "disabled",
 	[BR_STATE_LISTENING] = "listening",
@@ -87,6 +91,9 @@ int print_linkinfo(const struct sockaddr_nl *who,
 	if (!(ifi->ifi_family == AF_BRIDGE || ifi->ifi_family == AF_UNSPEC))
 		return 0;
 
+	if (filter_index && filter_index != ifi->ifi_index)
+		return 0;
+
 	parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), len);
 
 	if (tb[IFLA_IFNAME] == NULL) {
@@ -136,3 +143,213 @@ int print_linkinfo(const struct sockaddr_nl *who,
 	fflush(fp);
 	return 0;
 }
+
+static void usage(void)
+{
+	fprintf(stderr, "Usage: bridge link set dev DEV [ cost COST ] [ priority PRIO ] [ state STATE ]\n");
+	fprintf(stderr, "                               [ guard {on | off} ]\n");
+	fprintf(stderr, "                               [ hairpin {on | off} ] \n");
+	fprintf(stderr, "                               [ fastleave {on | off} ]\n");
+	fprintf(stderr,	"                               [ root_block {on | off} ]\n");
+	fprintf(stderr, "                               [ hwmode {vepa | veb} ]\n");
+	fprintf(stderr, "       bridge link show [dev DEV]\n");
+	exit(-1);
+}
+
+static bool on_off(char *arg, __s8 *attr, char *val)
+{
+	if (strcmp(val, "on") == 0)
+		*attr = 1;
+	else if (strcmp(val, "off") == 0)
+		*attr = 0;
+	else {
+		fprintf(stderr,
+			"Error: argument of \"%s\" must be \"on\" or \"off\"\n",
+			arg);
+		return false;
+	}
+
+	return true;
+}
+
+static int brlink_modify(int argc, char **argv)
+{
+	struct {
+		struct nlmsghdr  n;
+		struct ifinfomsg ifm;
+		char             buf[512];
+	} req;
+	char *d = NULL;
+	__s8 hairpin = -1;
+	__s8 bpdu_guard = -1;
+	__s8 fast_leave = -1;
+	__u32 cost = 0;
+	__s16 priority = -1;
+	__s8 state = -1;
+	__s16 mode = -1;
+	__u16 flags = BRIDGE_FLAGS_MASTER;
+	struct rtattr *nest;
+
+	memset(&req, 0, sizeof(req));
+
+	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+	req.n.nlmsg_flags = NLM_F_REQUEST;
+	req.n.nlmsg_type = RTM_SETLINK;
+	req.ifm.ifi_family = PF_BRIDGE;
+
+	while (argc > 0) {
+		if (strcmp(*argv, "dev") == 0) {
+			NEXT_ARG();
+			d = *argv;
+		} else if (strcmp(*argv, "guard") == 0) {
+			NEXT_ARG();
+			if (!on_off("guard", &bpdu_guard, *argv))
+				exit(-1);
+		} else if (strcmp(*argv, "hairpin") == 0) {
+			NEXT_ARG();
+			if (!on_off("hairping", &hairpin, *argv))
+				exit(-1);
+		} else if (strcmp(*argv, "fastleave") == 0) {
+			NEXT_ARG();
+			if (!on_off("fastleave", &fast_leave, *argv))
+				exit(-1);
+		} else if (strcmp(*argv, "cost")) {
+			NEXT_ARG();
+			cost = atoi(*argv);
+		} else if (strcmp(*argv, "priority")) {
+			NEXT_ARG();
+			priority = atoi(*argv);
+		} else if (strcmp(*argv, "state")) {
+			NEXT_ARG();
+			state = atoi(*argv);
+		} else if (strcmp(*argv, "mode")) {
+			NEXT_ARG();
+			flags |= BRIDGE_FLAGS_SELF;
+			if (strcmp(*argv, "vepa") == 0)
+				mode = BRIDGE_MODE_VEPA;
+			else if (strcmp(*argv, "veb") == 0)
+				mode = BRIDGE_MODE_VEB;
+			else {
+				fprintf(stderr,
+					"Mode argument must be \"vepa\" or "
+					"\"veb\".\n");
+				exit(-1);
+			}
+		} else {
+			usage();
+		}
+		argc--; argv++;
+	}
+	if (d == NULL) {
+		fprintf(stderr, "Device is a required argument.\n");
+		exit(-1);
+	}
+
+
+	req.ifm.ifi_index = ll_name_to_index(d);
+	if (req.ifm.ifi_index == 0) {
+		fprintf(stderr, "Cannot find bridge device \"%s\"\n", d);
+		exit(-1);
+	}
+
+	/* Nested PROTINFO attribute.  Contains: port flags, cost, priority and
+	 * state.
+	 */
+	nest = addattr_nest(&req.n, sizeof(req),
+			    IFLA_PROTINFO | NLA_F_NESTED);
+	/* Flags first */
+	if (bpdu_guard >= 0)
+		addattr8(&req.n, sizeof(req), IFLA_BRPORT_GUARD, bpdu_guard);
+	if (hairpin >= 0)
+		addattr8(&req.n, sizeof(req), IFLA_BRPORT_MODE, hairpin);
+	if (fast_leave >= 0)
+		addattr8(&req.n, sizeof(req), IFLA_BRPORT_FAST_LEAVE,
+			 fast_leave);
+
+	if (cost > 0)
+		addattr32(&req.n, sizeof(req), IFLA_BRPORT_COST, cost);
+
+	if (priority >= 0)
+		addattr16(&req.n, sizeof(req), IFLA_BRPORT_PRIORITY, priority);
+
+	if (state >= 0)
+		addattr8(&req.n, sizeof(req), IFLA_BRPORT_STATE, state);
+
+	addattr_nest_end(&req.n, nest);
+
+	/* IFLA_AF_SPEC nested attribute.  Contains IFLA_BRIDGE_FLAGS that
+	 * designates master or self operation as well as 'vepa' or 'veb'
+	 * operation modes.  These are only valid in 'self' mode on some
+	 * devices so far.  Thus we only need to include the flags attribute
+	 * if we are setting the hw mode.
+	 */
+	if (mode >= 0) {
+		nest = addattr_nest(&req.n, sizeof(req), IFLA_AF_SPEC);
+
+		addattr16(&req.n, sizeof(req), IFLA_BRIDGE_FLAGS, flags);
+
+		if (mode >= 0)
+			addattr16(&req.n, sizeof(req), IFLA_BRIDGE_MODE, mode);
+
+		addattr_nest_end(&req.n, nest);
+	}
+
+	if (rtnl_talk(&rth, &req.n, 0, 0, NULL) < 0)
+		exit(2);
+
+	return 0;
+}
+
+static int brlink_show(int argc, char **argv)
+{
+	char *filter_dev = NULL;
+
+	while (argc > 0) {
+		if (strcmp(*argv, "dev") == 0) {
+			NEXT_ARG();
+			if (filter_dev)
+				duparg("dev", *argv);
+			filter_dev = *argv;
+		}
+		argc--; argv++;
+	}
+
+	if (filter_dev) {
+		if ((filter_index = ll_name_to_index(filter_dev)) == 0) {
+			fprintf(stderr, "Cannot find device \"%s\"\n",
+				filter_dev);
+			return -1;
+		}
+	}
+
+	if (rtnl_wilddump_request(&rth, PF_BRIDGE, RTM_GETLINK) < 0) {
+		perror("Cannon send dump request");
+		exit(1);
+	}
+
+	if (rtnl_dump_filter(&rth, print_linkinfo, stdout) < 0) {
+		fprintf(stderr, "Dump terminated\n");
+		exit(1);
+	}
+	return 0;
+}
+
+int do_link(int argc, char **argv)
+{
+	ll_init_map(&rth);
+	if (argc > 0) {
+		if (matches(*argv, "set") == 0 ||
+		    matches(*argv, "change") == 0)
+			return brlink_modify(argc-1, argv+1);
+		if (matches(*argv, "show") == 0 ||
+		    matches(*argv, "lst") == 0 ||
+		    matches(*argv, "list") == 0)
+			return brlink_show(argc-1, argv+1);
+		if (matches(*argv, "help") == 0)
+			usage();
+	} else
+		return brlink_show(0, NULL);
+
+	fprintf(stderr, "Command \"%s\" is unknown, try \"bridge link help\".\n", *argv);
+	exit(-1);
+}