/* * feat_bitmap.h: bitmap for managing feature invocation * * Copyright (c) 2013 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef included_vnet_l2_feat_bitmap_h #define included_vnet_l2_feat_bitmap_h #include <vlib/vlib.h> #include <vnet/vnet.h> /* * The feature bitmap is a way of organizing input and output feature graph nodes. * The set of features to be executed are arranged in a bitmap with one bit per * feature and each bit positioned in the same order that the features should be * executed. Features can be dynamically removed from the set by masking off their * corresponding bits. The bitmap is stored in packet context. Each feature clears * its bit and then calls feat_bitmap_get_next_node_index() to go to the next * graph node. */ /* 32 features in a u32 bitmap */ #define FEAT_MAX 32 /** Initialize the feature next-node indexes of a graph node. Should be called by the init function of each feature graph node. */ always_inline void feat_bitmap_init_next_nodes (vlib_main_t * vm, u32 node_index, /* the current graph node index */ u32 num_features, /* number of entries in feat_names */ char **feat_names, /* array of feature graph node names */ u32 * next_nodes) /* array of 32 next indexes to init */ { u32 idx; ASSERT (num_features <= FEAT_MAX); for (idx = 0; idx < num_features; idx++) { if (vlib_get_node_by_name (vm, (u8 *) feat_names[idx])) { next_nodes[idx] = vlib_node_add_named_next (vm, node_index, feat_names[idx]); } else { // Node may be in plugin which is not installed, use drop node next_nodes[idx] = vlib_node_add_named_next (vm, node_index, "feature-bitmap-drop"); } } /* All unassigned bits go to the drop node */ for (; idx < FEAT_MAX; idx++) { next_nodes[idx] = vlib_node_add_named_next (vm, node_index, "feature-bitmap-drop"); } } /** Return the graph node index for the feature corresponding to the first set bit in the bitmap. */ always_inline u32 feat_bitmap_get_next_node_index (u32 * next_nodes, u32 bitmap) { u32 first_bit; first_bit = count_leading_zeros (bitmap); first_bit = uword_bits - 1 - first_bit; return next_nodes[first_bit]; } /** Return the graph node index for the feature corresponding to the next set bit after clearing the current feature bit in the feature_bitmap of the current packet. */ always_inline u32 vnet_l2_feature_next (vlib_buffer_t * b, u32 * next_nodes, u32 feat_bit) { vnet_buffer (b)->l2.feature_bitmap &= ~feat_bit; u32 fb = vnet_buffer (b)->l2.feature_bitmap; ASSERT (fb != 0); return feat_bitmap_get_next_node_index (next_nodes, fb); } #endif /* included_vnet_l2_feat_bitmap_h */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */