From 3c37745ec614ff048d5dce38f976804b05d307ee Mon Sep 17 00:00:00 2001 From: Or Gerlitz Date: Tue, 17 Oct 2017 12:33:43 +0200 Subject: [PATCH] net/mlx5e: Properly deal with encap flows add/del under neigh update Currently, the encap action offload is handled in the actions parse function and not in mlx5e_tc_add_fdb_flow() where we deal with all the other aspects of offloading actions (vlan, modify header) and the rule itself. When the neigh update code (mlx5e_tc_encap_flows_add()) recreates the encap entry and offloads the related flows, we wrongly call again into mlx5e_tc_add_fdb_flow(), this for itself would cause us to handle again the offloading of vlans and header re-write which puts things in non consistent state and step on freed memory (e.g the modify header parse buffer which is already freed). Since on error, mlx5e_tc_add_fdb_flow() detaches and may release the encap entry, it causes a corruption at the neigh update code which goes over the list of flows associated with this encap entry, or double free when the tc flow is later deleted by user-space. When neigh update (mlx5e_tc_encap_flows_del()) unoffloads the flows related to an encap entry which is now invalid, we do a partial repeat of the eswitch flow removal code which is wrong too. To fix things up we do the following: (1) handle the encap action offload in the eswitch flow add function mlx5e_tc_add_fdb_flow() as done for the other actions and the rule itself. (2) modify the neigh update code (mlx5e_tc_encap_flows_add/del) to only deal with the encap entry and rules delete/add and not with any of the other offloaded actions. Fixes: 232c001398ae ('net/mlx5e: Add support to neighbour update flow') Signed-off-by: Or Gerlitz Reviewed-by: Paul Blakey Signed-off-by: Saeed Mahameed --- .../net/ethernet/mellanox/mlx5/core/en_tc.c | 89 +++++++++++-------- 1 file changed, 54 insertions(+), 35 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c index 1aa2028ed995..9ba1f72060aa 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -78,9 +78,11 @@ struct mlx5e_tc_flow { }; struct mlx5e_tc_flow_parse_attr { + struct ip_tunnel_info tun_info; struct mlx5_flow_spec spec; int num_mod_hdr_actions; void *mod_hdr_actions; + int mirred_ifindex; }; enum { @@ -322,6 +324,12 @@ static void mlx5e_tc_del_nic_flow(struct mlx5e_priv *priv, static void mlx5e_detach_encap(struct mlx5e_priv *priv, struct mlx5e_tc_flow *flow); +static int mlx5e_attach_encap(struct mlx5e_priv *priv, + struct ip_tunnel_info *tun_info, + struct net_device *mirred_dev, + struct net_device **encap_dev, + struct mlx5e_tc_flow *flow); + static struct mlx5_flow_handle * mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv, struct mlx5e_tc_flow_parse_attr *parse_attr, @@ -329,9 +337,27 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv, { struct mlx5_eswitch *esw = priv->mdev->priv.eswitch; struct mlx5_esw_flow_attr *attr = flow->esw_attr; - struct mlx5_flow_handle *rule; + struct net_device *out_dev, *encap_dev = NULL; + struct mlx5_flow_handle *rule = NULL; + struct mlx5e_rep_priv *rpriv; + struct mlx5e_priv *out_priv; int err; + if (attr->action & MLX5_FLOW_CONTEXT_ACTION_ENCAP) { + out_dev = __dev_get_by_index(dev_net(priv->netdev), + attr->parse_attr->mirred_ifindex); + err = mlx5e_attach_encap(priv, &parse_attr->tun_info, + out_dev, &encap_dev, flow); + if (err) { + rule = ERR_PTR(err); + if (err != -EAGAIN) + goto err_attach_encap; + } + out_priv = netdev_priv(encap_dev); + rpriv = out_priv->ppriv; + attr->out_rep = rpriv->rep; + } + err = mlx5_eswitch_add_vlan_action(esw, attr); if (err) { rule = ERR_PTR(err); @@ -347,10 +373,14 @@ mlx5e_tc_add_fdb_flow(struct mlx5e_priv *priv, } } - rule = mlx5_eswitch_add_offloaded_rule(esw, &parse_attr->spec, attr); - if (IS_ERR(rule)) - goto err_add_rule; - + /* we get here if (1) there's no error (rule being null) or when + * (2) there's an encap action and we're on -EAGAIN (no valid neigh) + */ + if (rule != ERR_PTR(-EAGAIN)) { + rule = mlx5_eswitch_add_offloaded_rule(esw, &parse_attr->spec, attr); + if (IS_ERR(rule)) + goto err_add_rule; + } return rule; err_add_rule: @@ -361,6 +391,7 @@ err_mod_hdr: err_add_vlan: if (attr->action & MLX5_FLOW_CONTEXT_ACTION_ENCAP) mlx5e_detach_encap(priv, flow); +err_attach_encap: return rule; } @@ -389,6 +420,8 @@ static void mlx5e_tc_del_fdb_flow(struct mlx5e_priv *priv, void mlx5e_tc_encap_flows_add(struct mlx5e_priv *priv, struct mlx5e_encap_entry *e) { + struct mlx5_eswitch *esw = priv->mdev->priv.eswitch; + struct mlx5_esw_flow_attr *esw_attr; struct mlx5e_tc_flow *flow; int err; @@ -404,10 +437,9 @@ void mlx5e_tc_encap_flows_add(struct mlx5e_priv *priv, mlx5e_rep_queue_neigh_stats_work(priv); list_for_each_entry(flow, &e->flows, encap) { - flow->esw_attr->encap_id = e->encap_id; - flow->rule = mlx5e_tc_add_fdb_flow(priv, - flow->esw_attr->parse_attr, - flow); + esw_attr = flow->esw_attr; + esw_attr->encap_id = e->encap_id; + flow->rule = mlx5_eswitch_add_offloaded_rule(esw, &esw_attr->parse_attr->spec, esw_attr); if (IS_ERR(flow->rule)) { err = PTR_ERR(flow->rule); mlx5_core_warn(priv->mdev, "Failed to update cached encapsulation flow, %d\n", @@ -421,15 +453,13 @@ void mlx5e_tc_encap_flows_add(struct mlx5e_priv *priv, void mlx5e_tc_encap_flows_del(struct mlx5e_priv *priv, struct mlx5e_encap_entry *e) { + struct mlx5_eswitch *esw = priv->mdev->priv.eswitch; struct mlx5e_tc_flow *flow; - struct mlx5_fc *counter; list_for_each_entry(flow, &e->flows, encap) { if (flow->flags & MLX5E_TC_FLOW_OFFLOADED) { flow->flags &= ~MLX5E_TC_FLOW_OFFLOADED; - counter = mlx5_flow_rule_counter(flow->rule); - mlx5_del_flow_rules(flow->rule); - mlx5_fc_destroy(priv->mdev, counter); + mlx5_eswitch_del_offloaded_rule(esw, flow->rule, flow->esw_attr); } } @@ -1942,7 +1972,7 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv, struct tcf_exts *exts, if (is_tcf_mirred_egress_redirect(a)) { int ifindex = tcf_mirred_ifindex(a); - struct net_device *out_dev, *encap_dev = NULL; + struct net_device *out_dev; struct mlx5e_priv *out_priv; out_dev = __dev_get_by_index(dev_net(priv->netdev), ifindex); @@ -1955,17 +1985,13 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv, struct tcf_exts *exts, rpriv = out_priv->ppriv; attr->out_rep = rpriv->rep; } else if (encap) { - err = mlx5e_attach_encap(priv, info, - out_dev, &encap_dev, flow); - if (err && err != -EAGAIN) - return err; + parse_attr->mirred_ifindex = ifindex; + parse_attr->tun_info = *info; + attr->parse_attr = parse_attr; attr->action |= MLX5_FLOW_CONTEXT_ACTION_ENCAP | MLX5_FLOW_CONTEXT_ACTION_FWD_DEST | MLX5_FLOW_CONTEXT_ACTION_COUNT; - out_priv = netdev_priv(encap_dev); - rpriv = out_priv->ppriv; - attr->out_rep = rpriv->rep; - attr->parse_attr = parse_attr; + /* attr->out_rep is resolved when we handle encap */ } else { pr_err("devices %s %s not on same switch HW, can't offload forwarding\n", priv->netdev->name, out_dev->name); @@ -2047,7 +2073,7 @@ int mlx5e_configure_flower(struct mlx5e_priv *priv, if (flow->flags & MLX5E_TC_FLOW_ESWITCH) { err = parse_tc_fdb_actions(priv, f->exts, parse_attr, flow); if (err < 0) - goto err_handle_encap_flow; + goto err_free; flow->rule = mlx5e_tc_add_fdb_flow(priv, parse_attr, flow); } else { err = parse_tc_nic_actions(priv, f->exts, parse_attr, flow); @@ -2058,10 +2084,13 @@ int mlx5e_configure_flower(struct mlx5e_priv *priv, if (IS_ERR(flow->rule)) { err = PTR_ERR(flow->rule); - goto err_free; + if (err != -EAGAIN) + goto err_free; } - flow->flags |= MLX5E_TC_FLOW_OFFLOADED; + if (err != -EAGAIN) + flow->flags |= MLX5E_TC_FLOW_OFFLOADED; + err = rhashtable_insert_fast(&tc->ht, &flow->node, tc->ht_params); if (err) @@ -2075,16 +2104,6 @@ int mlx5e_configure_flower(struct mlx5e_priv *priv, err_del_rule: mlx5e_tc_del_flow(priv, flow); -err_handle_encap_flow: - if (err == -EAGAIN) { - err = rhashtable_insert_fast(&tc->ht, &flow->node, - tc->ht_params); - if (err) - mlx5e_tc_del_flow(priv, flow); - else - return 0; - } - err_free: kvfree(parse_attr); kfree(flow); -- 2.20.1