iplink: bridge: Add support for bridge FDB learning limits

Support setting the FDB limit through ip link. The arguments is:
 - fdb_max_learned: A 32-bit unsigned integer specifying the maximum
                    number of learned FDB entries, with 0 disabling
                    the limit.

Also support reading back the current number of learned FDB entries in
the bridge by this count. The returned value's name is:
 - fdb_n_learned: A 32-bit unsigned integer specifying the current number
                  of learned FDB entries.

Example:

 # ip -d -j -p link show br0
[ {
...
        "linkinfo": {
            "info_kind": "bridge",
            "info_data": {
...
                "fdb_n_learned": 2,
                "fdb_max_learned": 0,
...
            }
        },
...
    } ]
 # ip link set br0 type bridge fdb_max_learned 1024
 # ip -d -j -p link show br0
[ {
...
        "linkinfo": {
            "info_kind": "bridge",
            "info_data": {
...
                "fdb_n_learned": 2,
                "fdb_max_learned": 1024,
...
            }
        },
...
    } ]

Signed-off-by: Johannes Nixdorf <jnixdorf-oss@avm.de>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David Ahern <dsahern@kernel.org>

diff --git a/ip/iplink_bridge.c b/ip/iplink_bridge.c
index 4620752953082563b00db1af18f0bcd4b301c744..6b70ffbb6f5f4bc194ec8bda162fd9ce725439a1 100644 (file)
--- a/ip/iplink_bridge.c
+++ b/ip/iplink_bridge.c
@@ -34,6 +34,7 @@ static void print_explain(FILE *f)
                "                 [ group_fwd_mask MASK ]\n"
                "                 [ group_address ADDRESS ]\n"
                "                 [ no_linklocal_learn NO_LINKLOCAL_LEARN ]\n"
+               "                 [ fdb_max_learned FDB_MAX_LEARNED ]\n"
                "                 [ vlan_filtering VLAN_FILTERING ]\n"
                "                 [ vlan_protocol VLAN_PROTOCOL ]\n"
                "                 [ vlan_default_pvid VLAN_DEFAULT_PVID ]\n"
@@ -168,6 +169,14 @@ static int bridge_parse_opt(struct link_util *lu, int argc, char **argv,
                                bm.optval |= no_ll_learn_bit;
                        else
                                bm.optval &= ~no_ll_learn_bit;
+               } else if (strcmp(*argv, "fdb_max_learned") == 0) {
+                       __u32 fdb_max_learned;
+
+                       NEXT_ARG();
+                       if (get_u32(&fdb_max_learned, *argv, 0))
+                               invarg("invalid fdb_max_learned", *argv);
+
+                       addattr32(n, 1024, IFLA_BR_FDB_MAX_LEARNED, fdb_max_learned);
                } else if (matches(*argv, "fdb_flush") == 0) {
                        addattr(n, 1024, IFLA_BR_FDB_FLUSH);
                } else if (matches(*argv, "vlan_default_pvid") == 0) {
@@ -544,6 +553,18 @@ static void bridge_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
        if (tb[IFLA_BR_GC_TIMER])
                _bridge_print_timer(f, "gc_timer", tb[IFLA_BR_GC_TIMER]);
 
+       if (tb[IFLA_BR_FDB_N_LEARNED])
+               print_uint(PRINT_ANY,
+                          "fdb_n_learned",
+                          "fdb_n_learned %u ",
+                          rta_getattr_u32(tb[IFLA_BR_FDB_N_LEARNED]));
+
+       if (tb[IFLA_BR_FDB_MAX_LEARNED])
+               print_uint(PRINT_ANY,
+                          "fdb_max_learned",
+                          "fdb_max_learned %u ",
+                          rta_getattr_u32(tb[IFLA_BR_FDB_MAX_LEARNED]));
+
        if (tb[IFLA_BR_VLAN_DEFAULT_PVID])
                print_uint(PRINT_ANY,
                           "vlan_default_pvid",

diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
index 7365d0c6b14f90c396565c34a9959a28d8b2388e..e82b2dbb00706f233978d495c539e2fd61a2a019 100644 (file)
--- a/man/man8/ip-link.8.in
+++ b/man/man8/ip-link.8.in
@@ -1630,6 +1630,8 @@ the following additional arguments are supported:
 ] [
 .BI no_linklocal_learn " NO_LINKLOCAL_LEARN "
 ] [
+.BI fdb_max_learned " FDB_MAX_LEARNED "
+] [
 .BI vlan_filtering " VLAN_FILTERING "
 ] [
 .BI vlan_protocol " VLAN_PROTOCOL "
@@ -1741,6 +1743,14 @@ or off
 When disabled, the bridge will not learn from link-local frames (default:
 enabled).
 
+.BI fdb_max_learned " FDB_MAX_LEARNED "
+- set the maximum number of learned FDB entries. If
+.RI ( FDB_MAX_LEARNED " == 0) "
+the feature is disabled. Default is
+.BR 0 .
+.I FDB_MAX_LEARNED
+is a 32bit unsigned integer.
+
 .BI vlan_filtering " VLAN_FILTERING "
 - turn VLAN filtering on
 .RI ( VLAN_FILTERING " > 0) "