OpenTTD Source  12.0-beta2
host.cpp
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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 
10 #include "../../stdafx.h"
11 #include "../../debug.h"
12 #include "address.h"
13 
14 #include "../../safeguards.h"
15 
22 
23 #if defined(HAVE_GETIFADDRS)
24 static void NetworkFindBroadcastIPsInternal(NetworkAddressList *broadcast) // GETIFADDRS implementation
25 {
26  struct ifaddrs *ifap, *ifa;
27 
28  if (getifaddrs(&ifap) != 0) return;
29 
30  for (ifa = ifap; ifa != nullptr; ifa = ifa->ifa_next) {
31  if (!(ifa->ifa_flags & IFF_BROADCAST)) continue;
32  if (ifa->ifa_broadaddr == nullptr) continue;
33  if (ifa->ifa_broadaddr->sa_family != AF_INET) continue;
34 
35  NetworkAddress addr(ifa->ifa_broadaddr, sizeof(sockaddr));
36  if (std::none_of(broadcast->begin(), broadcast->end(), [&addr](NetworkAddress const& elem) -> bool { return elem == addr; })) broadcast->push_back(addr);
37  }
38  freeifaddrs(ifap);
39 }
40 
41 #elif defined(_WIN32)
42 static void NetworkFindBroadcastIPsInternal(NetworkAddressList *broadcast) // Win32 implementation
43 {
44  SOCKET sock = socket(AF_INET, SOCK_DGRAM, 0);
45  if (sock == INVALID_SOCKET) return;
46 
47  DWORD len = 0;
48  int num = 2;
49  INTERFACE_INFO *ifo = CallocT<INTERFACE_INFO>(num);
50 
51  for (;;) {
52  if (WSAIoctl(sock, SIO_GET_INTERFACE_LIST, nullptr, 0, ifo, num * sizeof(*ifo), &len, nullptr, nullptr) == 0) break;
53  free(ifo);
54  if (WSAGetLastError() != WSAEFAULT) {
55  closesocket(sock);
56  return;
57  }
58  num *= 2;
59  ifo = CallocT<INTERFACE_INFO>(num);
60  }
61 
62  for (uint j = 0; j < len / sizeof(*ifo); j++) {
63  if (ifo[j].iiFlags & IFF_LOOPBACK) continue;
64  if (!(ifo[j].iiFlags & IFF_BROADCAST)) continue;
65 
66  sockaddr_storage address;
67  memset(&address, 0, sizeof(address));
68  /* iiBroadcast is unusable, because it always seems to be set to 255.255.255.255. */
69  memcpy(&address, &ifo[j].iiAddress.Address, sizeof(sockaddr));
70  ((sockaddr_in*)&address)->sin_addr.s_addr = ifo[j].iiAddress.AddressIn.sin_addr.s_addr | ~ifo[j].iiNetmask.AddressIn.sin_addr.s_addr;
71  NetworkAddress addr(address, sizeof(sockaddr));
72  if (std::none_of(broadcast->begin(), broadcast->end(), [&addr](NetworkAddress const& elem) -> bool { return elem == addr; })) broadcast->push_back(addr);
73  }
74 
75  free(ifo);
76  closesocket(sock);
77 }
78 
79 #else /* not HAVE_GETIFADDRS */
80 
81 #include "../../string_func.h"
82 
83 static void NetworkFindBroadcastIPsInternal(NetworkAddressList *broadcast) // !GETIFADDRS implementation
84 {
85  SOCKET sock = socket(AF_INET, SOCK_DGRAM, 0);
86  if (sock == INVALID_SOCKET) return;
87 
88  char buf[4 * 1024]; // Arbitrary buffer size
89  struct ifconf ifconf;
90 
91  ifconf.ifc_len = sizeof(buf);
92  ifconf.ifc_buf = buf;
93  if (ioctl(sock, SIOCGIFCONF, &ifconf) == -1) {
94  closesocket(sock);
95  return;
96  }
97 
98  const char *buf_end = buf + ifconf.ifc_len;
99  for (const char *p = buf; p < buf_end;) {
100  const struct ifreq *req = (const struct ifreq*)p;
101 
102  if (req->ifr_addr.sa_family == AF_INET) {
103  struct ifreq r;
104 
105  strecpy(r.ifr_name, req->ifr_name, lastof(r.ifr_name));
106  if (ioctl(sock, SIOCGIFFLAGS, &r) != -1 &&
107  (r.ifr_flags & IFF_BROADCAST) &&
108  ioctl(sock, SIOCGIFBRDADDR, &r) != -1) {
109  NetworkAddress addr(&r.ifr_broadaddr, sizeof(sockaddr));
110  if (std::none_of(broadcast->begin(), broadcast->end(), [&addr](NetworkAddress const& elem) -> bool { return elem == addr; })) broadcast->push_back(addr);
111  }
112  }
113 
114  p += sizeof(struct ifreq);
115 #if defined(AF_LINK) && !defined(SUNOS)
116  p += req->ifr_addr.sa_len - sizeof(struct sockaddr);
117 #endif
118  }
119 
120  closesocket(sock);
121 }
122 #endif /* all NetworkFindBroadcastIPsInternals */
123 
130 {
132 
133  /* Now display to the debug all the detected ips */
134  Debug(net, 3, "Detected broadcast addresses:");
135  int i = 0;
136  for (NetworkAddress &addr : *broadcast) {
137  addr.SetPort(NETWORK_DEFAULT_PORT);
138  Debug(net, 3, " {}) {}", i++, addr.GetHostname());
139  }
140 }
NETWORK_DEFAULT_PORT
static const uint16 NETWORK_DEFAULT_PORT
The default port of the game server (TCP & UDP)
Definition: config.h:28
NetworkAddressList
std::vector< NetworkAddress > NetworkAddressList
Type for a list of addresses.
Definition: address.h:21
address.h
NetworkFindBroadcastIPsInternal
static void NetworkFindBroadcastIPsInternal(NetworkAddressList *broadcast)
Internal implementation for finding the broadcast IPs.
Definition: host.cpp:83
NetworkAddress
Wrapper for (un)resolved network addresses; there's no reason to transform a numeric IP to a string a...
Definition: address.h:30
NetworkFindBroadcastIPs
void NetworkFindBroadcastIPs(NetworkAddressList *broadcast)
Find the IPv4 broadcast addresses; IPv6 uses a completely different strategy for broadcasting.
Definition: host.cpp:129
Debug
#define Debug(name, level, format_string,...)
Ouptut a line of debugging information.
Definition: debug.h:37
strecpy
char * strecpy(char *dst, const char *src, const char *last)
Copies characters from one buffer to another.
Definition: string.cpp:112
free
static void free(const void *ptr)
Version of the standard free that accepts const pointers.
Definition: stdafx.h:460
lastof
#define lastof(x)
Get the last element of an fixed size array.
Definition: stdafx.h:394