[PATCH net-next v4 12/12] net: bridge: fdb: add support for flush filtering based on ifindex and vlan

Nikolay Aleksandrov
2022-04-13T10:52:57Z

Add support for fdb flush filtering based on destination ifindex and
vlan id. The ifindex must either match a port's device ifindex or the
bridge's. The vlan support is trivial since it's already validated by
rtnl_fdb_del, we just need to fill it in.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
v2: validate ifindex and fill in vlan id
v3: NDFA -> NDA attributes
v4: use port's ifindex if NTF_MASTER is used and NDA_IFINDEX is not
specified

net/bridge/br_fdb.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 74d759d09f94..1a3d583fbc8e 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -622,12 +622,44 @@ static unsigned long __ndm_flags_to_fdb_flags(u8 ndm_flags)
return flags;
}

+static int __fdb_flush_validate_ifindex(const struct net_bridge *br,
+ int ifindex,
+ struct netlink_ext_ack *extack)
+{
+ const struct net_device *dev;
+
+ dev = __dev_get_by_index(dev_net(br->dev), ifindex);
+ if (!dev) {
+ NL_SET_ERR_MSG_MOD(extack, "Unknown flush device ifindex");
+ return -ENODEV;
+ }
+ if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev)) {
+ NL_SET_ERR_MSG_MOD(extack, "Flush device is not a bridge or bridge port");
+ return -EINVAL;
+ }
+ if (netif_is_bridge_master(dev) && dev != br->dev) {
+ NL_SET_ERR_MSG_MOD(extack,
+ "Flush bridge device does not match target bridge device");
+ return -EINVAL;
+ }
+ if (netif_is_bridge_port(dev)) {
+ struct net_bridge_port *p = br_port_get_rtnl(dev);
+
+ if (p->br != br) {
+ NL_SET_ERR_MSG_MOD(extack, "Port belongs to a different bridge device");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],
struct net_device *dev, u16 vid,
struct netlink_ext_ack *extack)
{
u8 ndm_flags = ndm->ndm_flags & ~FDB_FLUSH_IGNORED_NDM_FLAGS;
- struct net_bridge_fdb_flush_desc desc = {};
+ struct net_bridge_fdb_flush_desc desc = { .vlan_id = vid };
struct net_bridge_port *p = NULL;
struct net_bridge *br;

@@ -663,6 +695,17 @@ int br_fdb_delete_bulk(struct ndmsg *ndm, struct nlattr *tb[],

desc.flags_mask |= __ndm_flags_to_fdb_flags(ndm_flags_mask);
}
+ if (tb[NDA_IFINDEX]) {
+ int err, ifidx = nla_get_s32(tb[NDA_IFINDEX]);
+
+ err = __fdb_flush_validate_ifindex(br, ifidx, extack);
+ if (err)
+ return err;
+ desc.port_ifindex = ifidx;
+ } else if (p) {
+ /* flush was invoked with port device and NTF_MASTER */
+ desc.port_ifindex = p->dev->ifindex;
+ }

br_debug(br, "flushing port ifindex: %d vlan id: %u flags: 0x%lx flags mask: 0x%lx\n",
desc.port_ifindex, desc.vlan_id, desc.flags, desc.flags_mask);
--
2.35.1