Messages in this thread | | | Date | Thu, 21 Sep 2023 15:41:50 +0300 | Subject | Re: [PATCH net-next v4 4/6] net: bridge: Add netlink knobs for number / max learned FDB entries | From | Nikolay Aleksandrov <> |
| |
On 9/19/23 11:12, Johannes Nixdorf wrote: > The previous patch added accounting and a limit for the number of > dynamically learned FDB entries per bridge. However it did not provide > means to actually configure those bounds or read back the count. This > patch does that. > > Two new netlink attributes are added for the accounting and limit of > dynamically learned FDB entries: > - IFLA_BR_FDB_N_LEARNED (RO) for the number of entries accounted for > a single bridge. > - IFLA_BR_FDB_MAX_LEARNED (RW) for the configured limit of entries for > the bridge. > > The new attributes are used like this: > > # ip link add name br up type bridge fdb_max_learned 256 > # ip link add name v1 up master br type veth peer v2 > # ip link set up dev v2 > # mausezahn -a rand -c 1024 v2 > 0.01 seconds (90877 packets per second > # bridge fdb | grep -v permanent | wc -l > 256 > # ip -d link show dev br > 13: br: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 [...] > [...] fdb_n_learned 256 fdb_max_learned 256 > > Signed-off-by: Johannes Nixdorf <jnixdorf-oss@avm.de> > --- > include/uapi/linux/if_link.h | 2 ++ > net/bridge/br_netlink.c | 15 ++++++++++++++- > 2 files changed, 16 insertions(+), 1 deletion(-) > > diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h > index ce3117df9cec..0486f314c176 100644 > --- a/include/uapi/linux/if_link.h > +++ b/include/uapi/linux/if_link.h > @@ -510,6 +510,8 @@ enum { > IFLA_BR_VLAN_STATS_PER_PORT, > IFLA_BR_MULTI_BOOLOPT, > IFLA_BR_MCAST_QUERIER_STATE, > + IFLA_BR_FDB_N_LEARNED, > + IFLA_BR_FDB_MAX_LEARNED, > __IFLA_BR_MAX, > }; > > diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c > index 505683ef9a26..f5d49a05e61b 100644 > --- a/net/bridge/br_netlink.c > +++ b/net/bridge/br_netlink.c > @@ -1267,6 +1267,8 @@ static const struct nla_policy br_policy[IFLA_BR_MAX + 1] = { > [IFLA_BR_VLAN_STATS_PER_PORT] = { .type = NLA_U8 }, > [IFLA_BR_MULTI_BOOLOPT] = > NLA_POLICY_EXACT_LEN(sizeof(struct br_boolopt_multi)), > + [IFLA_BR_FDB_N_LEARNED] = { .type = NLA_U32 }, > + [IFLA_BR_FDB_MAX_LEARNED] = { .type = NLA_U32 }, > }; > > static int br_changelink(struct net_device *brdev, struct nlattr *tb[], > @@ -1541,6 +1543,12 @@ static int br_changelink(struct net_device *brdev, struct nlattr *tb[], > return err; > } > > + if (data[IFLA_BR_FDB_MAX_LEARNED]) { > + u32 val = nla_get_u32(data[IFLA_BR_FDB_MAX_LEARNED]); > + > + WRITE_ONCE(br->fdb_max_learned, val); > + } > + > return 0; > } > > @@ -1595,6 +1603,8 @@ static size_t br_get_size(const struct net_device *brdev) > nla_total_size_64bit(sizeof(u64)) + /* IFLA_BR_TOPOLOGY_CHANGE_TIMER */ > nla_total_size_64bit(sizeof(u64)) + /* IFLA_BR_GC_TIMER */ > nla_total_size(ETH_ALEN) + /* IFLA_BR_GROUP_ADDR */ > + nla_total_size(sizeof(u32)) + /* IFLA_BR_FDB_N_LEARNED */ > + nla_total_size(sizeof(u32)) + /* IFLA_BR_FDB_MAX_LEARNED */ > #ifdef CONFIG_BRIDGE_IGMP_SNOOPING > nla_total_size(sizeof(u8)) + /* IFLA_BR_MCAST_ROUTER */ > nla_total_size(sizeof(u8)) + /* IFLA_BR_MCAST_SNOOPING */ > @@ -1670,7 +1680,10 @@ static int br_fill_info(struct sk_buff *skb, const struct net_device *brdev) > nla_put_u8(skb, IFLA_BR_TOPOLOGY_CHANGE_DETECTED, > br->topology_change_detected) || > nla_put(skb, IFLA_BR_GROUP_ADDR, ETH_ALEN, br->group_addr) || > - nla_put(skb, IFLA_BR_MULTI_BOOLOPT, sizeof(bm), &bm)) > + nla_put(skb, IFLA_BR_MULTI_BOOLOPT, sizeof(bm), &bm) || > + nla_put_u32(skb, IFLA_BR_FDB_N_LEARNED, > + atomic_read(&br->fdb_n_learned)) || > + nla_put_u32(skb, IFLA_BR_FDB_MAX_LEARNED, br->fdb_max_learned)) > return -EMSGSIZE; > > #ifdef CONFIG_BRIDGE_VLAN_FILTERING >
Actually you're using atomic for counting, but using a u32 for the limit, you should cap it because the count can overflow. Or you should use atomic64 for the counting.
| |