entries.h

/* Copyright 2013-present Barefoot Networks, Inc.
 *
 * 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.
 */
 
/*
 * Antonin Bas (antonin@barefootnetworks.com)
 *
 */
 
#ifndef BM_BM_SIM_ENTRIES_H_
#define BM_BM_SIM_ENTRIES_H_
 
#include <memory>
#include <utility>
 
#include "actions.h"
#include "bytecontainer.h"
#include "control_flow.h"
 
namespace bm {
 
class ControlFlowNode;
 
struct MatchEntry {
  ByteContainer key{};
  ActionFnEntry action_entry{};  // includes action data
  const ControlFlowNode *next_table{nullptr};
 
  MatchEntry() {}
 
  MatchEntry(ByteContainer key,
             ActionFnEntry action_entry,
             const ControlFlowNode *next_table)
  : key(std::move(key)), action_entry(std::move(action_entry)),
    next_table(next_table) {}
 
  MatchEntry(const MatchEntry &other) = delete;
  MatchEntry &operator=(const MatchEntry &other) = delete;
 
  MatchEntry(MatchEntry &&other) = default;
  MatchEntry &operator=(MatchEntry &&other) = default;
};
 
struct ExactMatchEntry: MatchEntry {
  ExactMatchEntry()
    : MatchEntry() {}
 
  ExactMatchEntry(ByteContainer key,
                  ActionFnEntry action_entry,
                  const ControlFlowNode *next_table)
    : MatchEntry(std::move(key), std::move(action_entry), next_table) {}
};
 
struct LongestPrefixMatchEntry : MatchEntry {
  int prefix_length{0};
 
  LongestPrefixMatchEntry()
    : MatchEntry() {}
 
  LongestPrefixMatchEntry(ByteContainer key,
                          ActionFnEntry action_entry,
                          unsigned int prefix_length,
                          const ControlFlowNode *next_table)
    : MatchEntry(std::move(key), std::move(action_entry), next_table),
    prefix_length(prefix_length) {
    unsigned byte_index = prefix_length / 8;
    unsigned mod = prefix_length % 8;
    if (mod > 0) {
      byte_index++;
      this->key[byte_index] &= ~(0xFF >> mod);
    }
    for (; byte_index < key.size(); byte_index++) {
      this->key[byte_index] = 0;
    }
  }
};
 
struct TernaryMatchEntry : MatchEntry {
  ByteContainer mask{};
  int priority{0};
 
  TernaryMatchEntry()
    : MatchEntry() {}
 
  TernaryMatchEntry(ByteContainer key, ActionFnEntry action_entry,
                    ByteContainer mask, int priority,
                    const ControlFlowNode *next_table)
    : MatchEntry(std::move(key), std::move(action_entry), next_table),
    mask(std::move(mask)), priority(priority) {
    for (unsigned byte_index = 0; byte_index < key.size(); byte_index++) {
      this->key[byte_index] &= mask[byte_index];
    }
  }
};
 
}  // namespace bm
 
#endif  // BM_BM_SIM_ENTRIES_H_