src/network/address.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "address.h"
  21
  22 #include <cstdio>
  23 #include <iostream>
  24 #include <cstdlib>
  25 #include <cstring>
  26 #include <cerrno>
  27 #include <sstream>
  28 #include <iomanip>
  29 #include "network/networkexceptions.h"
  30 #include "util/string.h"
  31 #include "util/numeric.h"
  32 #include "constants.h"
  33 #include "debug.h"
  34 #include "settings.h"
  35 #include "log.h"
  36
  37 #ifdef _WIN32
  38 // Without this some of the network functions are not found on mingw
  39 #ifndef _WIN32_WINNT
  40 #define _WIN32_WINNT 0x0501
  41 #endif
  42 #include <windows.h>
  43 #include <winsock2.h>
  44 #include <ws2tcpip.h>
  45 #define LAST_SOCKET_ERR() WSAGetLastError()
  46 typedef SOCKET socket_t;
  47 typedef int socklen_t;
  48 #else
  49 #include <sys/types.h>
  50 #include <sys/socket.h>
  51 #include <netinet/in.h>
  52 #include <fcntl.h>
  53 #include <netdb.h>
  54 #include <unistd.h>
  55 #include <arpa/inet.h>
  56 #define LAST_SOCKET_ERR() (errno)
  57 typedef int socket_t;
  58 #endif
  59
  60 /*
  61         Address
  62 */
  63
  64 Address::Address()
  65 {
  66         memset(&m_address, 0, sizeof(m_address));
  67 }
  68
  69 Address::Address(u32 address, u16 port)
  70 {
  71         memset(&m_address, 0, sizeof(m_address));
  72         setAddress(address);
  73         setPort(port);
  74 }
  75
  76 Address::Address(u8 a, u8 b, u8 c, u8 d, u16 port)
  77 {
  78         memset(&m_address, 0, sizeof(m_address));
  79         setAddress(a, b, c, d);
  80         setPort(port);
  81 }
  82
  83 Address::Address(const IPv6AddressBytes *ipv6_bytes, u16 port)
  84 {
  85         memset(&m_address, 0, sizeof(m_address));
  86         setAddress(ipv6_bytes);
  87         setPort(port);
  88 }
  89
  90 // Equality (address family, IP and port must be equal)
  91 bool Address::operator==(const Address &other)
  92 {
  93         if (other.m_addr_family != m_addr_family || other.m_port != m_port)
  94                 return false;
  95
  96         if (m_addr_family == AF_INET) {
  97                 return m_address.ipv4.s_addr == other.m_address.ipv4.s_addr;
  98         }
  99
 100         if (m_addr_family == AF_INET6) {
 101                 return memcmp(m_address.ipv6.s6_addr,
 102                                 other.m_address.ipv6.s6_addr, 16) == 0;
 103         }
 104
 105         return false;
 106 }
 107
 108 void Address::Resolve(const char *name)
 109 {
 110         if (!name || name[0] == 0) {
 111                 if (m_addr_family == AF_INET)
 112                         setAddress(static_cast<u32>(0));
 113                 else if (m_addr_family == AF_INET6)
 114                         setAddress(static_cast<IPv6AddressBytes*>(nullptr));
 115                 return;
 116         }
 117
 118         struct addrinfo *resolved, hints;
 119         memset(&hints, 0, sizeof(hints));
 120
 121         // Setup hints
 122         if (g_settings->getBool("enable_ipv6")) {
 123                 // AF_UNSPEC allows both IPv6 and IPv4 addresses to be returned
 124                 hints.ai_family = AF_UNSPEC;
 125         } else {
 126                 hints.ai_family = AF_INET;
 127         }
 128
 129         // Do getaddrinfo()
 130         int e = getaddrinfo(name, NULL, &hints, &resolved);
 131         if (e != 0)
 132                 throw ResolveError(gai_strerror(e));
 133
 134         // Copy data
 135         if (resolved->ai_family == AF_INET) {
 136                 struct sockaddr_in *t = (struct sockaddr_in *)resolved->ai_addr;
 137                 m_addr_family = AF_INET;
 138                 m_address.ipv4 = t->sin_addr;
 139         } else if (resolved->ai_family == AF_INET6) {
 140                 struct sockaddr_in6 *t = (struct sockaddr_in6 *)resolved->ai_addr;
 141                 m_addr_family = AF_INET6;
 142                 m_address.ipv6 = t->sin6_addr;
 143         } else {
 144                 m_addr_family = 0;
 145         }
 146         freeaddrinfo(resolved);
 147 }
 148
 149 // IP address -> textual representation
 150 std::string Address::serializeString() const
 151 {
 152 // windows XP doesnt have inet_ntop, maybe use better func
 153 #ifdef _WIN32
 154         if (m_addr_family == AF_INET) {
 155                 return inet_ntoa(m_address.ipv4);
 156         } else if (m_addr_family == AF_INET6) {
 157                 std::ostringstream os;
 158                 os << std::hex;
 159                 for (int i = 0; i < 16; i += 2) {
 160                         u16 section = (m_address.ipv6.s6_addr[i] << 8) |
 161                                         (m_address.ipv6.s6_addr[i + 1]);
 162                         os << section;
 163                         if (i < 14)
 164                                 os << ":";
 165                 }
 166                 return os.str();
 167         } else {
 168                 return "";
 169         }
 170 #else
 171         char str[INET6_ADDRSTRLEN];
 172         if (inet_ntop(m_addr_family, (void*) &m_address, str, sizeof(str)) == nullptr)
 173                 return "";
 174         return str;
 175 #endif
 176 }
 177
 178 struct in_addr Address::getAddress() const
 179 {
 180         return m_address.ipv4;
 181 }
 182
 183 struct in6_addr Address::getAddress6() const
 184 {
 185         return m_address.ipv6;
 186 }
 187
 188 u16 Address::getPort() const
 189 {
 190         return m_port;
 191 }
 192
 193 bool Address::isZero() const
 194 {
 195         if (m_addr_family == AF_INET) {
 196                 return m_address.ipv4.s_addr == 0;
 197         }
 198
 199         if (m_addr_family == AF_INET6) {
 200                 static const char zero[16] = {0};
 201                 return memcmp(m_address.ipv6.s6_addr, zero, 16) == 0;
 202         }
 203
 204         return false;
 205 }
 206
 207 void Address::setAddress(u32 address)
 208 {
 209         m_addr_family = AF_INET;
 210         m_address.ipv4.s_addr = htonl(address);
 211 }
 212
 213 void Address::setAddress(u8 a, u8 b, u8 c, u8 d)
 214 {
 215         u32 addr = (a << 24) | (b << 16) | (c << 8) | d;
 216         setAddress(addr);
 217 }
 218
 219 void Address::setAddress(const IPv6AddressBytes *ipv6_bytes)
 220 {
 221         m_addr_family = AF_INET6;
 222         if (ipv6_bytes)
 223                 memcpy(m_address.ipv6.s6_addr, ipv6_bytes->bytes, 16);
 224         else
 225                 memset(m_address.ipv6.s6_addr, 0, 16);
 226 }
 227
 228 void Address::setPort(u16 port)
 229 {
 230         m_port = port;
 231 }
 232
 233 void Address::print(std::ostream& s) const
 234 {
 235         if (m_addr_family == AF_INET6)
 236                 s << "[" << serializeString() << "]:" << m_port;
 237         else if (m_addr_family == AF_INET)
 238                 s << serializeString() << ":" << m_port;
 239         else
 240                 s << "(undefined)";
 241 }
 242
 243 bool Address::isLocalhost() const
 244 {
 245         if (isIPv6()) {
 246                 static const u8 localhost_bytes[] = {
 247                                 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1};
 248                 static const u8 mapped_ipv4_localhost[] = {
 249                                 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff, 0x7f, 0, 0, 0};
 250
 251                 auto addr = m_address.ipv6.s6_addr;
 252
 253                 return memcmp(addr, localhost_bytes, 16) == 0 ||
 254                         memcmp(addr, mapped_ipv4_localhost, 13) == 0;
 255         }
 256
 257         auto addr = ntohl(m_address.ipv4.s_addr);
 258         return (addr >> 24) == 0x7f;
 259 }