/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * In addition, for the avoidance of any doubt, permission is granted to
 * link this program with OpenSSL and to (re)distribute the binaries
 * produced as the result of such linking.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include "query-local-address.hh"
#include "iputils.hh"
#include "dns_random.hh"

namespace pdns {
  static const ComboAddress local4("0.0.0.0");
  static const ComboAddress local6("::");

  static vector<ComboAddress> g_localQueryAddresses4;
  static vector<ComboAddress> g_localQueryAddresses6;

  ComboAddress getQueryLocalAddress(const sa_family_t family, const in_port_t port) {
    ComboAddress ret;
    if (family==AF_INET) {
      if (g_localQueryAddresses4.empty()) {
        ret = local4;
      } else if (g_localQueryAddresses4.size() == 1) {
        ret = g_localQueryAddresses4.at(0);
      } else {
        ret = g_localQueryAddresses4[dns_random(g_localQueryAddresses4.size())];
      }
      ret.sin4.sin_port = htons(port);
    }
    else {
      if (g_localQueryAddresses6.empty()) {
        ret = local6;
      } else if (g_localQueryAddresses6.size() == 1) {
        ret = g_localQueryAddresses6.at(0);
      } else {
        ret = g_localQueryAddresses6[dns_random(g_localQueryAddresses6.size())];
      }
      ret.sin6.sin6_port = htons(port);
    }
    return ret;
  }

  ComboAddress getNonAnyQueryLocalAddress(const sa_family_t family) {
    if (family == AF_INET) {
      for (const auto& addr : pdns::g_localQueryAddresses4) {
        if (!IsAnyAddress(addr)) {
          return addr;
        }
      }
    }
    if (family == AF_INET6) {
      for (const auto& addr : pdns::g_localQueryAddresses6) {
        if (!IsAnyAddress(addr)) {
          return addr;
        }
      }
    }
    ComboAddress ret("0.0.0.0");
    ret.reset(); // Ensure all is zero, even the addr family
    return ret;
  }

  void parseQueryLocalAddress(const std::string &qla) {
    vector<string> addrs;
    stringtok(addrs, qla, ", ;");
    for(const string& addr : addrs) {
      ComboAddress tmp(addr);
      if (tmp.isIPv4()) {
        g_localQueryAddresses4.push_back(tmp);
        continue;
      }
      g_localQueryAddresses6.push_back(tmp);
    }
  }

  bool isQueryLocalAddressFamilyEnabled(const sa_family_t family) {
    if (family == AF_INET) {
      return !g_localQueryAddresses4.empty();
    }
    if (family == AF_INET6) {
      return !g_localQueryAddresses6.empty();
    }
    return false;
  }
} // namespace pdns