ice: Add a per-VF limit on number of FDIR filters

While the iavf driver adds a s/w limit (128) on the number of FDIR
filters that the VF can request, a malicious VF driver can request more
than that and exhaust the resources for other VFs.

Add a similar limit in ice.

CC: stable@vger.kernel.org
Fixes: 1f7ea1cd ("ice: Enable FDIR Configure for AVF")
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Suggested-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ice/ice_ethtool_fdir.c

@@ -534,7 +534,7 @@ ice_parse_rx_flow_user_data(struct ethtool_rx_flow_spec *fsp,
  *
  * Returns the number of available flow director filters to this VSI
  */
-static int ice_fdir_num_avail_fltr(struct ice_hw *hw, struct ice_vsi *vsi)
+int ice_fdir_num_avail_fltr(struct ice_hw *hw, struct ice_vsi *vsi)
 {
 	u16 vsi_num = ice_get_hw_vsi_num(hw, vsi->idx);
 	u16 num_guar;

drivers/net/ethernet/intel/ice/ice_fdir.h

@@ -207,6 +207,8 @@ struct ice_fdir_base_pkt {
 	const u8 *tun_pkt;
 };
 
+struct ice_vsi;
+
 int ice_alloc_fd_res_cntr(struct ice_hw *hw, u16 *cntr_id);
 int ice_free_fd_res_cntr(struct ice_hw *hw, u16 cntr_id);
 int ice_alloc_fd_guar_item(struct ice_hw *hw, u16 *cntr_id, u16 num_fltr);
@@ -218,6 +220,7 @@ int
 ice_fdir_get_gen_prgm_pkt(struct ice_hw *hw, struct ice_fdir_fltr *input,
 			  u8 *pkt, bool frag, bool tun);
 int ice_get_fdir_cnt_all(struct ice_hw *hw);
+int ice_fdir_num_avail_fltr(struct ice_hw *hw, struct ice_vsi *vsi);
 bool ice_fdir_is_dup_fltr(struct ice_hw *hw, struct ice_fdir_fltr *input);
 bool ice_fdir_has_frag(enum ice_fltr_ptype flow);
 struct ice_fdir_fltr *

drivers/net/ethernet/intel/ice/ice_virtchnl_fdir.c

@@ -536,6 +536,8 @@ static void ice_vc_fdir_reset_cnt_all(struct ice_vf_fdir *fdir)
 		fdir->fdir_fltr_cnt[flow][0] = 0;
 		fdir->fdir_fltr_cnt[flow][1] = 0;
 	}
+
+	fdir->fdir_fltr_cnt_total = 0;
 }
 
 /**
@@ -1560,6 +1562,7 @@ ice_vc_add_fdir_fltr_post(struct ice_vf *vf, struct ice_vf_fdir_ctx *ctx,
 	resp->status = status;
 	resp->flow_id = conf->flow_id;
 	vf->fdir.fdir_fltr_cnt[conf->input.flow_type][is_tun]++;
+	vf->fdir.fdir_fltr_cnt_total++;
 
 	ret = ice_vc_send_msg_to_vf(vf, ctx->v_opcode, v_ret,
 				    (u8 *)resp, len);
@@ -1624,6 +1627,7 @@ ice_vc_del_fdir_fltr_post(struct ice_vf *vf, struct ice_vf_fdir_ctx *ctx,
 	resp->status = status;
 	ice_vc_fdir_remove_entry(vf, conf, conf->flow_id);
 	vf->fdir.fdir_fltr_cnt[conf->input.flow_type][is_tun]--;
+	vf->fdir.fdir_fltr_cnt_total--;
 
 	ret = ice_vc_send_msg_to_vf(vf, ctx->v_opcode, v_ret,
 				    (u8 *)resp, len);
@@ -1790,6 +1794,7 @@ int ice_vc_add_fdir_fltr(struct ice_vf *vf, u8 *msg)
 	struct virtchnl_fdir_add *stat = NULL;
 	struct virtchnl_fdir_fltr_conf *conf;
 	enum virtchnl_status_code v_ret;
+	struct ice_vsi *vf_vsi;
 	struct device *dev;
 	struct ice_pf *pf;
 	int is_tun = 0;
@@ -1798,6 +1803,17 @@ int ice_vc_add_fdir_fltr(struct ice_vf *vf, u8 *msg)
 
 	pf = vf->pf;
 	dev = ice_pf_to_dev(pf);
+	vf_vsi = ice_get_vf_vsi(vf);
+
+#define ICE_VF_MAX_FDIR_FILTERS	128
+	if (!ice_fdir_num_avail_fltr(&pf->hw, vf_vsi) ||
+	    vf->fdir.fdir_fltr_cnt_total >= ICE_VF_MAX_FDIR_FILTERS) {
+		v_ret = VIRTCHNL_STATUS_ERR_PARAM;
+		dev_err(dev, "Max number of FDIR filters for VF %d is reached\n",
+			vf->vf_id);
+		goto err_exit;
+	}
+
 	ret = ice_vc_fdir_param_check(vf, fltr->vsi_id);
 	if (ret) {
 		v_ret = VIRTCHNL_STATUS_ERR_PARAM;

drivers/net/ethernet/intel/ice/ice_virtchnl_fdir.h

@@ -29,6 +29,7 @@ struct ice_vf_fdir_ctx {
 struct ice_vf_fdir {
 	u16 fdir_fltr_cnt[ICE_FLTR_PTYPE_MAX][ICE_FD_HW_SEG_MAX];
 	int prof_entry_cnt[ICE_FLTR_PTYPE_MAX][ICE_FD_HW_SEG_MAX];
+	u16 fdir_fltr_cnt_total;
 	struct ice_fd_hw_prof **fdir_prof;
 
 	struct idr fdir_rule_idr;