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 "address.h"
13
14 #include "../../safeguards.h"
15
16 /**
17 * Internal implementation for finding the broadcast IPs.
18 * This function is implemented multiple times for multiple targets.
19 * @param broadcast the list of broadcasts to write into.
20 */
21 static void NetworkFindBroadcastIPsInternal(NetworkAddressList *broadcast);
22
23 #if defined(HAVE_GETIFADDRS)
NetworkFindBroadcastIPsInternal(NetworkAddressList * broadcast)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)
NetworkFindBroadcastIPsInternal(NetworkAddressList * broadcast)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
NetworkFindBroadcastIPsInternal(NetworkAddressList * broadcast)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
124 /**
125 * Find the IPv4 broadcast addresses; IPv6 uses a completely different
126 * strategy for broadcasting.
127 * @param broadcast the list of broadcasts to write into.
128 */
NetworkFindBroadcastIPs(NetworkAddressList * broadcast)129 void NetworkFindBroadcastIPs(NetworkAddressList *broadcast)
130 {
131 NetworkFindBroadcastIPsInternal(broadcast);
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 }
141