From af641713e97da4126439c3fb1dee031f7e497654 Mon Sep 17 00:00:00 2001 From: Petr Machata Date: Fri, 3 Nov 2017 10:03:40 +0100 Subject: [PATCH] mlxsw: spectrum_router: Onload conflicting tunnels The approach for offloading IP tunnels implemented currently by mlxsw doesn't allow two tunnels that have the same local IP address in the same (underlay) VRF. Previously, offloads were introduced on demand as encap routes were formed. When such a route was created that would cause offload of a conflicting tunnel, mlxsw_sp_ipip_entry_create() would detect it and return -EEXIST, which would propagate up and cause FIB abort. Now however IPIP entries are created as soon as an offloadable netdevice is created, and the failure prevents creation of such device. Furthermore, if the driver is installed at the point where such conflicting tunnels exist, the failure actually prevents successful modprobe. Furthermore, follow-up patches implement handling of NETDEV_CHANGE due to the local address change. However, NETDEV_CHANGE can't be vetoed. The failure merely means that the offloads weren't updated, but the change in Linux configuration is not rolled back. It is thus desirable to have a robust way of handling these conflicts, which can later be reused for handling NETDEV_CHANGE as well. To fix this, when a conflicting tunnel is created, instead of failing, simply pull the old tunnel to slow path and reject offloading the new one. Introduce two functions: mlxsw_sp_ipip_entry_demote_tunnel() and mlxsw_sp_ipip_demote_tunnel_by_saddr() to handle this. Make them both public, because they will be useful later on in this patchset. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- .../ethernet/mellanox/mlxsw/spectrum_router.c | 73 +++++++++++++------ .../ethernet/mellanox/mlxsw/spectrum_router.h | 8 ++ 2 files changed, 60 insertions(+), 21 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c index 897a3841e52f..832bfa125512 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c @@ -1159,24 +1159,7 @@ mlxsw_sp_ipip_entry_create(struct mlxsw_sp *mlxsw_sp, enum mlxsw_sp_ipip_type ipipt, struct net_device *ol_dev) { - u32 ul_tb_id = mlxsw_sp_ipip_dev_ul_tb_id(ol_dev); - struct mlxsw_sp_router *router = mlxsw_sp->router; struct mlxsw_sp_ipip_entry *ipip_entry; - enum mlxsw_sp_l3proto ul_proto; - union mlxsw_sp_l3addr saddr; - - /* The configuration where several tunnels have the same local address - * in the same underlay table needs special treatment in the HW. That is - * currently not implemented in the driver. - */ - ul_proto = router->ipip_ops_arr[ipipt]->ul_proto; - saddr = mlxsw_sp_ipip_netdev_saddr(ul_proto, ol_dev); - list_for_each_entry(ipip_entry, &mlxsw_sp->router->ipip_list, - ipip_list_node) { - if (mlxsw_sp_ipip_entry_saddr_matches(mlxsw_sp, ul_proto, saddr, - ul_tb_id, ipip_entry)) - return ERR_PTR(-EEXIST); - } ipip_entry = mlxsw_sp_ipip_entry_alloc(mlxsw_sp, ipipt, ol_dev); if (IS_ERR(ipip_entry)) @@ -1292,14 +1275,24 @@ static int mlxsw_sp_netdevice_ipip_ol_reg_event(struct mlxsw_sp *mlxsw_sp, struct net_device *ol_dev) { struct mlxsw_sp_ipip_entry *ipip_entry; + enum mlxsw_sp_l3proto ul_proto; enum mlxsw_sp_ipip_type ipipt; + union mlxsw_sp_l3addr saddr; + u32 ul_tb_id; mlxsw_sp_netdev_ipip_type(mlxsw_sp, ol_dev, &ipipt); if (mlxsw_sp_netdevice_ipip_can_offload(mlxsw_sp, ol_dev, ipipt)) { - ipip_entry = mlxsw_sp_ipip_entry_create(mlxsw_sp, ipipt, - ol_dev); - if (IS_ERR(ipip_entry)) - return PTR_ERR(ipip_entry); + ul_tb_id = mlxsw_sp_ipip_dev_ul_tb_id(ol_dev); + ul_proto = mlxsw_sp->router->ipip_ops_arr[ipipt]->ul_proto; + saddr = mlxsw_sp_ipip_netdev_saddr(ul_proto, ol_dev); + if (!mlxsw_sp_ipip_demote_tunnel_by_saddr(mlxsw_sp, ul_proto, + saddr, ul_tb_id, + NULL)) { + ipip_entry = mlxsw_sp_ipip_entry_create(mlxsw_sp, ipipt, + ol_dev); + if (IS_ERR(ipip_entry)) + return PTR_ERR(ipip_entry); + } } return 0; @@ -1441,6 +1434,44 @@ static int mlxsw_sp_netdevice_ipip_ol_vrf_event(struct mlxsw_sp *mlxsw_sp, true, false, false, extack); } +void mlxsw_sp_ipip_entry_demote_tunnel(struct mlxsw_sp *mlxsw_sp, + struct mlxsw_sp_ipip_entry *ipip_entry) +{ + struct net_device *ol_dev = ipip_entry->ol_dev; + + if (ol_dev->flags & IFF_UP) + mlxsw_sp_ipip_entry_ol_down_event(mlxsw_sp, ipip_entry); + mlxsw_sp_ipip_entry_destroy(mlxsw_sp, ipip_entry); +} + +/* The configuration where several tunnels have the same local address in the + * same underlay table needs special treatment in the HW. That is currently not + * implemented in the driver. This function finds and demotes the first tunnel + * with a given source address, except the one passed in in the argument + * `except'. + */ +bool +mlxsw_sp_ipip_demote_tunnel_by_saddr(struct mlxsw_sp *mlxsw_sp, + enum mlxsw_sp_l3proto ul_proto, + union mlxsw_sp_l3addr saddr, + u32 ul_tb_id, + const struct mlxsw_sp_ipip_entry *except) +{ + struct mlxsw_sp_ipip_entry *ipip_entry, *tmp; + + list_for_each_entry_safe(ipip_entry, tmp, &mlxsw_sp->router->ipip_list, + ipip_list_node) { + if (ipip_entry != except && + mlxsw_sp_ipip_entry_saddr_matches(mlxsw_sp, ul_proto, saddr, + ul_tb_id, ipip_entry)) { + mlxsw_sp_ipip_entry_demote_tunnel(mlxsw_sp, ipip_entry); + return true; + } + } + + return false; +} + int mlxsw_sp_netdevice_ipip_ol_event(struct mlxsw_sp *mlxsw_sp, struct net_device *ol_dev, unsigned long event, diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.h b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.h index 4b8a12a4f493..5dd650bdcff6 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.h +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.h @@ -110,6 +110,14 @@ int __mlxsw_sp_ipip_entry_update_tunnel(struct mlxsw_sp *mlxsw_sp, bool keep_encap, bool update_nexthops, struct netlink_ext_ack *extack); +void mlxsw_sp_ipip_entry_demote_tunnel(struct mlxsw_sp *mlxsw_sp, + struct mlxsw_sp_ipip_entry *ipip_entry); +bool +mlxsw_sp_ipip_demote_tunnel_by_saddr(struct mlxsw_sp *mlxsw_sp, + enum mlxsw_sp_l3proto ul_proto, + union mlxsw_sp_l3addr saddr, + u32 ul_tb_id, + const struct mlxsw_sp_ipip_entry *except); struct mlxsw_sp_nexthop *mlxsw_sp_nexthop_next(struct mlxsw_sp_router *router, struct mlxsw_sp_nexthop *nh); bool mlxsw_sp_nexthop_offload(struct mlxsw_sp_nexthop *nh);