[PATCH iproute2-next v2] bridge: Add backup nexthop ID support

[Ido Schimmel <idosch@nvidia.com>]

Extend the bridge and ip utilities to set and show the backup nexthop ID
bridge port attribute. A value of 0 (default) disables the feature, in
which case the attribute is not printed since it is not emitted by the
kernel.

Example:

 # bridge -d link show dev swp1 | grep -o "backup_nhid [0-9]*"
 # bridge -d -j -p link show dev swp1 | jq '.[]["backup_nhid"]'
 null

 # bridge link set dev swp1 backup_nhid 10
 # bridge -d link show dev swp1 | grep -o "backup_nhid [0-9]*"
 backup_nhid 10
 # bridge -d -j -p link show dev swp1 | jq '.[]["backup_nhid"]'
 10

 # bridge link set dev swp1 backup_nhid 0
 # bridge -d link show dev swp1 | grep -o "backup_nhid [0-9]*"
 # bridge -d -j -p link show dev swp1 | jq '.[]["backup_nhid"]'
 null

 # ip -d link show dev swp1 | grep -o "backup_nhid [0-9]*"
 # ip -d -j -p lin show dev swp1 | jq '.[]["linkinfo"]["info_slave_data"]["backup_nhid"]'
 null

 # ip link set dev swp1 type bridge_slave backup_nhid 10
 # ip -d link show dev swp1 | grep -o "backup_nhid [0-9]*"
 backup_nhid 10
 # ip -d -j -p lin show dev swp1 | jq '.[]["linkinfo"]["info_slave_data"]["backup_nhid"]'
 10

 # ip link set dev swp1 type bridge_slave backup_nhid 0
 # ip -d link show dev swp1 | grep -o "backup_nhid [0-9]*"
 # ip -d -j -p lin show dev swp1 | jq '.[]["linkinfo"]["info_slave_data"]["backup_nhid"]'
 null

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
---
v2:
* Use __u32 instead of __s32 for backup nexthop ID
---
 bridge/link.c            | 16 ++++++++++++++++
 ip/iplink_bridge_slave.c | 13 +++++++++++++
 man/man8/bridge.8        |  9 +++++++++
 man/man8/ip-link.8.in    | 11 ++++++++++-
 4 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/bridge/link.c b/bridge/link.c
index af0457b6e04d..1c8faa85e7a5 100644
--- a/bridge/link.c
+++ b/bridge/link.c
@@ -187,6 +187,10 @@ static void print_protinfo(FILE *fp, struct rtattr *attr)
 				     ll_index_to_name(ifidx));
 		}
 
+		if (prtb[IFLA_BRPORT_BACKUP_NHID])
+			print_uint(PRINT_ANY, "backup_nhid", "backup_nhid %u ",
+				   rta_getattr_u32(prtb[IFLA_BRPORT_BACKUP_NHID]));
+
 		if (prtb[IFLA_BRPORT_ISOLATED])
 			print_on_off(PRINT_ANY, "isolated", "isolated %s ",
 				     rta_getattr_u8(prtb[IFLA_BRPORT_ISOLATED]));
@@ -316,6 +320,7 @@ static void usage(void)
 		"                               [ mab {on | off} ]\n"
 		"                               [ hwmode {vepa | veb} ]\n"
 		"                               [ backup_port DEVICE ] [ nobackup_port ]\n"
+		"                               [ backup_nhid NHID ]\n"
 		"                               [ self ] [ master ]\n"
 		"       bridge link show [dev DEV] [master DEVICE]\n");
 	exit(-1);
@@ -334,6 +339,8 @@ static int brlink_modify(int argc, char **argv)
 		.ifm.ifi_family = PF_BRIDGE,
 	};
 	char *d = NULL;
+	bool backup_nhid_set = false;
+	__u32 backup_nhid;
 	int backup_port_idx = -1;
 	__s8 neigh_suppress = -1;
 	__s8 neigh_vlan_suppress = -1;
@@ -498,6 +505,11 @@ static int brlink_modify(int argc, char **argv)
 			}
 		} else if (strcmp(*argv, "nobackup_port") == 0) {
 			backup_port_idx = 0;
+		} else if (strcmp(*argv, "backup_nhid") == 0) {
+			NEXT_ARG();
+			if (get_u32(&backup_nhid, *argv, 0))
+				invarg("invalid backup_nhid", *argv);
+			backup_nhid_set = true;
 		} else {
 			usage();
 		}
@@ -584,6 +596,10 @@ static int brlink_modify(int argc, char **argv)
 		addattr32(&req.n, sizeof(req), IFLA_BRPORT_BACKUP_PORT,
 			  backup_port_idx);
 
+	if (backup_nhid_set)
+		addattr32(&req.n, sizeof(req), IFLA_BRPORT_BACKUP_NHID,
+			  backup_nhid);
+
 	addattr_nest_end(&req.n, nest);
 
 	/* IFLA_AF_SPEC nested attribute. Contains IFLA_BRIDGE_FLAGS that
diff --git a/ip/iplink_bridge_slave.c b/ip/iplink_bridge_slave.c
index 11ab2113fe96..dc73c86574da 100644
--- a/ip/iplink_bridge_slave.c
+++ b/ip/iplink_bridge_slave.c
@@ -43,6 +43,7 @@ static void print_explain(FILE *f)
 		"			[ locked {on | off} ]\n"
 		"			[ mab {on | off} ]\n"
 		"			[ backup_port DEVICE ] [ nobackup_port ]\n"
+		"			[ backup_nhid NHID ]\n"
 	);
 }
 
@@ -301,6 +302,10 @@ static void bridge_slave_print_opt(struct link_util *lu, FILE *f,
 		print_string(PRINT_ANY, "backup_port", "backup_port %s ",
 			     ll_index_to_name(backup_p));
 	}
+
+	if (tb[IFLA_BRPORT_BACKUP_NHID])
+		print_uint(PRINT_ANY, "backup_nhid", "backup_nhid %u ",
+			   rta_getattr_u32(tb[IFLA_BRPORT_BACKUP_NHID]));
 }
 
 static void bridge_slave_parse_on_off(char *arg_name, char *arg_val,
@@ -436,6 +441,14 @@ static int bridge_slave_parse_opt(struct link_util *lu, int argc, char **argv,
 			addattr32(n, 1024, IFLA_BRPORT_BACKUP_PORT, ifindex);
 		} else if (matches(*argv, "nobackup_port") == 0) {
 			addattr32(n, 1024, IFLA_BRPORT_BACKUP_PORT, 0);
+		} else if (strcmp(*argv, "backup_nhid") == 0) {
+			__u32 backup_nhid;
+
+			NEXT_ARG();
+			if (get_u32(&backup_nhid, *argv, 0))
+				invarg("backup_nhid is invalid", *argv);
+			addattr32(n, 1024, IFLA_BRPORT_BACKUP_NHID,
+				  backup_nhid);
 		} else if (matches(*argv, "help") == 0) {
 			explain();
 			return -1;
diff --git a/man/man8/bridge.8 b/man/man8/bridge.8
index e05528199eab..dd0659d37df2 100644
--- a/man/man8/bridge.8
+++ b/man/man8/bridge.8
@@ -61,6 +61,8 @@ bridge \- show / manipulate bridge addresses and devices
 .B backup_port
 .IR  DEVICE " ] ["
 .BR nobackup_port " ] [ "
+.B backup_nhid
+.IR NHID " ] ["
 .BR self " ] [ " master " ]"
 
 .ti -8
@@ -647,6 +649,13 @@ configured backup port
 .B nobackup_port
 Removes the currently configured backup port
 
+.TP
+.BI backup_nhid " NHID"
+The FDB nexthop object ID (see \fBip-nexthop\fR(8)) to attach to packets being
+redirected to a backup port that has VLAN tunnel mapping enabled (via the
+\fBvlan_tunnel\fR option). Setting a value of 0 (default) has the effect of not
+attaching any ID.
+
 .TP
 .B self
 link setting is configured on specified physical device
diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index 8f07de9a8a25..7365d0c6b14f 100644
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -2540,7 +2540,10 @@ the following additional arguments are supported:
 ] [
 .BR backup_port " DEVICE"
 ] [
-.BR nobackup_port " ]"
+.BR nobackup_port
+] [
+.BR backup_nhid " NHID"
+]
 
 .in +8
 .sp
@@ -2679,6 +2682,12 @@ configured backup port
 .BR nobackup_port
 - removes the currently configured backup port
 
+.BI backup_nhid " NHID"
+- the FDB nexthop object ID (see \fBip-nexthop\fR(8)) to attach to packets
+being redirected to a backup port that has VLAN tunnel mapping enabled (via the
+\fBvlan_tunnel\fR option). Setting a value of 0 (default) has the effect of not
+attaching any ID.
+
 .in -8
 
 .TP
-- 
2.40.1