src/network/core/host.cpp

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   4  * OpenTTD 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.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file host.cpp Functions related to getting host specific data (IPs). */
   9
  10 #include "../../stdafx.h"
  11 #include "../../debug.h"
  12 #include "../../core/alloc_func.hpp"
  13 #include "address.h"
  14
  15 #include "../../safeguards.h"
  16
  17 /**
  18  * Internal implementation for finding the broadcast IPs.
  19  * This function is implemented multiple times for multiple targets.
  20  * @param broadcast the list of broadcasts to write into.
  21  */
  22 static void NetworkFindBroadcastIPsInternal(NetworkAddressList *broadcast);
  23
  24 #ifdef _WIN32
  25 static void NetworkFindBroadcastIPsInternal(NetworkAddressList *broadcast) // Win32 implementation
  26 {
  27         SOCKET sock = socket(AF_INET, SOCK_DGRAM, 0);
  28         if (sock == INVALID_SOCKET) return;
  29
  30         DWORD len = 0;
  31         int num = 2;
  32         INTERFACE_INFO *ifo = CallocT<INTERFACE_INFO>(num);
  33
  34         for (;;) {
  35                 if (WSAIoctl(sock, SIO_GET_INTERFACE_LIST, nullptr, 0, ifo, num * sizeof(*ifo), &len, nullptr, nullptr) == 0) break;
  36                 free(ifo);
  37                 if (WSAGetLastError() != WSAEFAULT) {
  38                         closesocket(sock);
  39                         return;
  40                 }
  41                 num *= 2;
  42                 ifo = CallocT<INTERFACE_INFO>(num);
  43         }
  44
  45         for (uint j = 0; j < len / sizeof(*ifo); j++) {
  46                 if (ifo[j].iiFlags & IFF_LOOPBACK) continue;
  47                 if (!(ifo[j].iiFlags & IFF_BROADCAST)) continue;
  48
  49                 sockaddr_storage address;
  50                 memset(&address, 0, sizeof(address));
  51                 /* iiBroadcast is unusable, because it always seems to be set to 255.255.255.255. */
  52                 memcpy(&address, &ifo[j].iiAddress.Address, sizeof(sockaddr));
  53                 ((sockaddr_in*)&address)->sin_addr.s_addr = ifo[j].iiAddress.AddressIn.sin_addr.s_addr | ~ifo[j].iiNetmask.AddressIn.sin_addr.s_addr;
  54                 NetworkAddress addr(address, sizeof(sockaddr));
  55                 if (std::none_of(broadcast->begin(), broadcast->end(), [&addr](NetworkAddress const &elem) -> bool { return elem == addr; })) broadcast->push_back(addr);
  56         }
  57
  58         free(ifo);
  59         closesocket(sock);
  60 }
  61
  62 #else /* not WIN32 */
  63 static void NetworkFindBroadcastIPsInternal(NetworkAddressList *broadcast)
  64 {
  65         struct ifaddrs *ifap, *ifa;
  66
  67         if (getifaddrs(&ifap) != 0) return;
  68
  69         for (ifa = ifap; ifa != nullptr; ifa = ifa->ifa_next) {
  70                 if (!(ifa->ifa_flags & IFF_BROADCAST)) continue;
  71                 if (ifa->ifa_broadaddr == nullptr) continue;
  72                 if (ifa->ifa_broadaddr->sa_family != AF_INET) continue;
  73
  74                 NetworkAddress addr(ifa->ifa_broadaddr, sizeof(sockaddr));
  75                 if (std::none_of(broadcast->begin(), broadcast->end(), [&addr](NetworkAddress const &elem) -> bool { return elem == addr; })) broadcast->push_back(addr);
  76         }
  77         freeifaddrs(ifap);
  78 }
  79 #endif /* all NetworkFindBroadcastIPsInternals */
  80
  81 /**
  82  * Find the IPv4 broadcast addresses; IPv6 uses a completely different
  83  * strategy for broadcasting.
  84  * @param broadcast the list of broadcasts to write into.
  85  */
  86 void NetworkFindBroadcastIPs(NetworkAddressList *broadcast)
  87 {
  88         NetworkFindBroadcastIPsInternal(broadcast);
  89
  90         /* Now display to the debug all the detected ips */
  91         Debug(net, 3, "Detected broadcast addresses:");
  92         int i = 0;
  93         for (NetworkAddress &addr : *broadcast) {
  94                 addr.SetPort(NETWORK_DEFAULT_PORT);
  95                 Debug(net, 3, "  {}) {}", i++, addr.GetHostname());
  96         }
  97 }