src/socket.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 "socket.h"
  21
  22 #ifdef _WIN32
  23         #ifndef WIN32_LEAN_AND_MEAN
  24                 #define WIN32_LEAN_AND_MEAN
  25         #endif
  26         // Without this some of the network functions are not found on mingw
  27         #ifndef _WIN32_WINNT
  28                 #define _WIN32_WINNT 0x0501
  29         #endif
  30         #include <windows.h>
  31         #include <winsock2.h>
  32         #include <ws2tcpip.h>
  33         #ifdef _MSC_VER
  34                 #pragma comment(lib, "ws2_32.lib")
  35         #endif
  36 typedef SOCKET socket_t;
  37 typedef int socklen_t;
  38 #else
  39         #include <sys/types.h>
  40         #include <sys/socket.h>
  41         #include <netinet/in.h>
  42         #include <fcntl.h>
  43         #include <netdb.h>
  44         #include <unistd.h>
  45         #include <arpa/inet.h>
  46 typedef int socket_t;
  47 #endif
  48
  49 #include "constants.h"
  50 #include "debug.h"
  51 #include "settings.h"
  52 #include "main.h" // for g_settings
  53 #include <stdio.h>
  54 #include <iostream>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <errno.h>
  58 #include <sstream>
  59 #include <iomanip>
  60 #include "util/string.h"
  61 #include "util/numeric.h"
  62
  63 // Set to true to enable verbose debug output
  64 bool socket_enable_debug_output = false;
  65
  66 bool g_sockets_initialized = false;
  67
  68 // Initialize sockets
  69 void sockets_init()
  70 {
  71 #ifdef _WIN32
  72         // Windows needs sockets to be initialized before use
  73         WSADATA WsaData;
  74         if(WSAStartup( MAKEWORD(2,2), &WsaData ) != NO_ERROR)
  75                 throw SocketException("WSAStartup failed");
  76 #endif
  77         g_sockets_initialized = true;
  78 }
  79
  80 void sockets_cleanup()
  81 {
  82 #ifdef _WIN32
  83         // On Windows, cleanup sockets after use
  84         WSACleanup();
  85 #endif
  86 }
  87
  88 /*
  89         Address
  90 */
  91
  92 Address::Address()
  93 {
  94         m_addr_family = 0;
  95         memset(&m_address, 0, sizeof m_address);
  96         m_port = 0;
  97 }
  98
  99 Address::Address(u32 address, u16 port)
 100 {
 101         setAddress(address);
 102         setPort(port);
 103 }
 104
 105 Address::Address(u8 a, u8 b, u8 c, u8 d, u16 port)
 106 {
 107         setAddress(a, b, c, d);
 108         setPort(port);
 109 }
 110
 111 Address::Address(const IPv6AddressBytes * ipv6_bytes, u16 port)
 112 {
 113         setAddress(ipv6_bytes);
 114         setPort(port);
 115 }
 116
 117 // Equality (address family, address and port must be equal)
 118 bool Address::operator==(Address &address)
 119 {
 120         if(address.m_addr_family != m_addr_family || address.m_port != m_port)
 121                 return false;
 122         else if(m_addr_family == AF_INET)
 123         {
 124                 return m_address.ipv4.sin_addr.s_addr ==
 125                        address.m_address.ipv4.sin_addr.s_addr;
 126         }
 127         else if(m_addr_family == AF_INET6)
 128         {
 129                 return memcmp(m_address.ipv6.sin6_addr.s6_addr,
 130                               address.m_address.ipv6.sin6_addr.s6_addr, 16) == 0;
 131         }
 132         else
 133                 return false;
 134 }
 135
 136 bool Address::operator!=(Address &address)
 137 {
 138         return !(*this == address);
 139 }
 140
 141 void Address::Resolve(const char *name)
 142 {
 143         struct addrinfo *resolved, hints;
 144         memset(&hints, 0, sizeof(hints));
 145
 146         // Setup hints
 147         hints.ai_socktype = 0;
 148         hints.ai_protocol = 0;
 149         hints.ai_flags    = 0;
 150         if(g_settings->getBool("enable_ipv6"))
 151         {
 152                 // AF_UNSPEC allows both IPv6 and IPv4 addresses to be returned
 153                 hints.ai_family = AF_UNSPEC;
 154         }
 155         else
 156         {
 157                 hints.ai_family = AF_INET;
 158         }
 159
 160         // Do getaddrinfo()
 161         int e = getaddrinfo(name, NULL, &hints, &resolved);
 162         if(e != 0)
 163                 throw ResolveError(gai_strerror(e));
 164
 165         // Copy data
 166         if(resolved->ai_family == AF_INET)
 167         {
 168                 struct sockaddr_in *t = (struct sockaddr_in *) resolved->ai_addr;
 169                 m_addr_family = AF_INET;
 170                 m_address.ipv4 = *t;
 171         }
 172         else if(resolved->ai_family == AF_INET6)
 173         {
 174                 struct sockaddr_in6 *t = (struct sockaddr_in6 *) resolved->ai_addr;
 175                 m_addr_family = AF_INET6;
 176                 m_address.ipv6 = *t;
 177         }
 178         else
 179         {
 180                 freeaddrinfo(resolved);
 181                 throw ResolveError("");
 182         }
 183         freeaddrinfo(resolved);
 184 }
 185
 186 // IP address -> textual representation
 187 std::string Address::serializeString() const
 188 {
 189 // windows XP doesnt have inet_ntop, maybe use better func
 190 #ifdef _WIN32
 191         if(m_addr_family == AF_INET)
 192         {
 193                 u8 a, b, c, d, addr;
 194                 addr = ntohl(m_address.ipv4.sin_addr.s_addr);
 195                 a = (addr & 0xFF000000) >> 24;
 196                 b = (addr & 0x00FF0000) >> 16;
 197                 c = (addr & 0x0000FF00) >> 8;
 198                 d = (addr & 0x000000FF);
 199                 return itos(a) + "." + itos(b) + "." + itos(c) + "." + itos(d);
 200         }
 201         else if(m_addr_family == AF_INET6)
 202         {
 203                 std::ostringstream os;
 204                 for(int i = 0; i < 16; i += 2)
 205                 {
 206                         u16 section =
 207                         (m_address.ipv6.sin6_addr.s6_addr[i] << 8) |
 208                         (m_address.ipv6.sin6_addr.s6_addr[i + 1]);
 209                         os << std::hex << section;
 210                         if(i < 14)
 211                                 os << ":";
 212                 }
 213                 return os.str();
 214         }
 215         else
 216                 return std::string("");
 217 #else
 218         char str[INET6_ADDRSTRLEN];
 219         if (inet_ntop(m_addr_family, (m_addr_family == AF_INET) ? (void*)&(m_address.ipv4.sin_addr) : (void*)&(m_address.ipv6.sin6_addr), str, INET6_ADDRSTRLEN) == NULL) {
 220                 return std::string("");
 221         }
 222         return std::string(str);
 223 #endif
 224 }
 225
 226 struct sockaddr_in Address::getAddress() const
 227 {
 228         return m_address.ipv4; // NOTE: NO PORT INCLUDED, use getPort()
 229 }
 230
 231 struct sockaddr_in6 Address::getAddress6() const
 232 {
 233         return m_address.ipv6; // NOTE: NO PORT INCLUDED, use getPort()
 234 }
 235
 236 u16 Address::getPort() const
 237 {
 238         return m_port;
 239 }
 240
 241 int Address::getFamily() const
 242 {
 243         return m_addr_family;
 244 }
 245
 246 bool Address::isIPv6() const
 247 {
 248         return m_addr_family == AF_INET6;
 249 }
 250
 251 void Address::setAddress(u32 address)
 252 {
 253         m_addr_family = AF_INET;
 254         m_address.ipv4.sin_family = AF_INET;
 255         m_address.ipv4.sin_addr.s_addr = htonl(address);
 256 }
 257
 258 void Address::setAddress(u8 a, u8 b, u8 c, u8 d)
 259 {
 260         m_addr_family = AF_INET;
 261         m_address.ipv4.sin_family = AF_INET;
 262         u32 addr = htonl((a << 24) | (b << 16) | (c << 8) | d);
 263         m_address.ipv4.sin_addr.s_addr = addr;
 264 }
 265
 266 void Address::setAddress(const IPv6AddressBytes * ipv6_bytes)
 267 {
 268         m_addr_family = AF_INET6;
 269         m_address.ipv6.sin6_family = AF_INET6;
 270         if(ipv6_bytes)
 271                 memcpy(m_address.ipv6.sin6_addr.s6_addr, ipv6_bytes->bytes, 16);
 272         else
 273                 memset(m_address.ipv6.sin6_addr.s6_addr, 0, 16);
 274 }
 275
 276 void Address::setPort(u16 port)
 277 {
 278         m_port = port;
 279 }
 280
 281 void Address::print(std::ostream *s) const
 282 {
 283         if(m_addr_family == AF_INET6)
 284         {
 285                 (*s) << "[" << serializeString() << "]:" << m_port;
 286         }
 287         else
 288         {
 289                 (*s) << serializeString() << ":" << m_port;
 290         }
 291 }
 292
 293 /*
 294         UDPSocket
 295 */
 296
 297 UDPSocket::UDPSocket(bool ipv6)
 298 {
 299         if(g_sockets_initialized == false)
 300                 throw SocketException("Sockets not initialized");
 301
 302         // Use IPv6 if specified
 303         m_addr_family = ipv6 ? AF_INET6 : AF_INET;
 304         m_handle = socket(m_addr_family, SOCK_DGRAM, IPPROTO_UDP);
 305
 306         if(socket_enable_debug_output)
 307         {
 308                 dstream << "UDPSocket(" << (int) m_handle
 309                         << ")::UDPSocket(): ipv6 = "
 310                         << (ipv6 ? "true" : "false")
 311                         << std::endl;
 312         }
 313
 314         if(m_handle <= 0)
 315         {
 316                 throw SocketException("Failed to create socket");
 317         }
 318
 319         setTimeoutMs(0);
 320 }
 321
 322 UDPSocket::~UDPSocket()
 323 {
 324         if(socket_enable_debug_output)
 325         {
 326                 dstream << "UDPSocket( " << (int) m_handle << ")::~UDPSocket()"
 327                         << std::endl;
 328         }
 329
 330 #ifdef _WIN32
 331         closesocket(m_handle);
 332 #else
 333         close(m_handle);
 334 #endif
 335 }
 336
 337 void UDPSocket::Bind(u16 port)
 338 {
 339         if(socket_enable_debug_output)
 340         {
 341                 dstream << "UDPSocket(" << (int) m_handle << ")::Bind(): "
 342                         << "port=" << port << std::endl;
 343         }
 344
 345         if(m_addr_family == AF_INET6)
 346         {
 347                 struct sockaddr_in6 address;
 348                 address.sin6_family = AF_INET6;
 349                 address.sin6_addr   = in6addr_any;
 350                 address.sin6_port   = htons(port);
 351
 352                 if(bind(m_handle, (const struct sockaddr *) &address,
 353                         sizeof(struct sockaddr_in6)) < 0)
 354                 {
 355                         dstream << (int) m_handle << ": Bind failed: "
 356                                 << strerror(errno) << std::endl;
 357                         throw SocketException("Failed to bind socket");
 358                 }
 359         }
 360         else
 361         {
 362                 struct sockaddr_in address;
 363                 address.sin_family      = AF_INET;
 364                 address.sin_addr.s_addr = INADDR_ANY;
 365                 address.sin_port        = htons(port);
 366
 367                 if(bind(m_handle, (const struct sockaddr *) &address,
 368                         sizeof(struct sockaddr_in)) < 0)
 369                 {
 370                         dstream << (int) m_handle << ": Bind failed: "
 371                                 << strerror(errno) << std::endl;
 372                         throw SocketException("Failed to bind socket");
 373                 }
 374         }
 375 }
 376
 377 void UDPSocket::Send(const Address & destination, const void * data, int size)
 378 {
 379         bool dumping_packet = false; // for INTERNET_SIMULATOR
 380
 381         if(INTERNET_SIMULATOR)
 382                 dumping_packet = (myrand() % INTERNET_SIMULATOR_PACKET_LOSS == 0);
 383
 384         if(socket_enable_debug_output)
 385         {
 386                 // Print packet destination and size
 387                 dstream << (int) m_handle << " -> ";
 388                 destination.print(&dstream);
 389                 dstream << ", size=" << size;
 390
 391                 // Print packet contents
 392                 dstream << ", data=";
 393                 for(int i = 0; i < size && i < 20; i++)
 394                 {
 395                         if(i % 2 == 0)
 396                                 dstream << " ";
 397                         unsigned int a = ((const unsigned char *) data)[i];
 398                         dstream << std::hex << std::setw(2) << std::setfill('0')
 399                                 << a;
 400                 }
 401
 402                 if(size > 20)
 403                         dstream << "...";
 404
 405                 if(dumping_packet)
 406                         dstream << " (DUMPED BY INTERNET_SIMULATOR)";
 407
 408                 dstream << std::endl;
 409         }
 410
 411         if(dumping_packet)
 412         {
 413                 // Lol let's forget it
 414                 dstream << "UDPSocket::Send(): "
 415                                    "INTERNET_SIMULATOR: dumping packet."
 416                                 << std::endl;
 417                 return;
 418         }
 419
 420         if(destination.getFamily() != m_addr_family)
 421                 throw SendFailedException("Address family mismatch");
 422
 423         int sent;
 424         if(m_addr_family == AF_INET6)
 425         {
 426                 struct sockaddr_in6 address = destination.getAddress6();
 427                 address.sin6_port = htons(destination.getPort());
 428                 sent = sendto(m_handle, (const char *) data, size,
 429                         0, (struct sockaddr *) &address, sizeof(struct sockaddr_in6));
 430         }
 431         else
 432         {
 433                 struct sockaddr_in address = destination.getAddress();
 434                 address.sin_port = htons(destination.getPort());
 435                 sent = sendto(m_handle, (const char *) data, size,
 436                         0, (struct sockaddr *) &address, sizeof(struct sockaddr_in));
 437         }
 438
 439         if(sent != size)
 440         {
 441                 throw SendFailedException("Failed to send packet");
 442         }
 443 }
 444
 445 int UDPSocket::Receive(Address & sender, void * data, int size)
 446 {
 447         // Return on timeout
 448         if(WaitData(m_timeout_ms) == false)
 449         {
 450                 return -1;
 451         }
 452
 453         int received;
 454         if(m_addr_family == AF_INET6)
 455         {
 456                 struct sockaddr_in6 address;
 457                 socklen_t address_len = sizeof(address);
 458
 459                 received = recvfrom(m_handle, (char *) data,
 460                                 size, 0, (struct sockaddr *) &address, &address_len);
 461
 462                 if(received < 0)
 463                         return -1;
 464
 465                 u16 address_port = ntohs(address.sin6_port);
 466                 IPv6AddressBytes bytes;
 467                 memcpy(bytes.bytes, address.sin6_addr.s6_addr, 16);
 468                 sender = Address(&bytes, address_port);
 469         }
 470         else
 471         {
 472                 struct sockaddr_in address;
 473                 socklen_t address_len = sizeof(address);
 474
 475                 received = recvfrom(m_handle, (char *) data,
 476                                 size, 0, (struct sockaddr *) &address, &address_len);
 477
 478                 if(received < 0)
 479                         return -1;
 480
 481                 u32 address_ip = ntohl(address.sin_addr.s_addr);
 482                 u16 address_port = ntohs(address.sin_port);
 483
 484                 sender = Address(address_ip, address_port);
 485         }
 486
 487         if(socket_enable_debug_output)
 488         {
 489                 // Print packet sender and size
 490                 dstream << (int) m_handle << " <- ";
 491                 sender.print(&dstream);
 492                 dstream << ", size=" << received;
 493
 494                 // Print packet contents
 495                 dstream << ", data=";
 496                 for(int i = 0; i < received && i < 20; i++)
 497                 {
 498                         if(i % 2 == 0)
 499                                 dstream << " ";
 500                         unsigned int a = ((const unsigned char *) data)[i];
 501                         dstream << std::hex << std::setw(2) << std::setfill('0')
 502                                 << a;
 503                 }
 504                 if(received > 20)
 505                         dstream << "...";
 506
 507                 dstream << std::endl;
 508         }
 509
 510         return received;
 511 }
 512
 513 int UDPSocket::GetHandle()
 514 {
 515         return m_handle;
 516 }
 517
 518 void UDPSocket::setTimeoutMs(int timeout_ms)
 519 {
 520         m_timeout_ms = timeout_ms;
 521 }
 522
 523 bool UDPSocket::WaitData(int timeout_ms)
 524 {
 525         fd_set readset;
 526         int result;
 527
 528         // Initialize the set
 529         FD_ZERO(&readset);
 530         FD_SET(m_handle, &readset);
 531
 532         // Initialize time out struct
 533         struct timeval tv;
 534         tv.tv_sec = 0;
 535         tv.tv_usec = timeout_ms * 1000;
 536
 537         // select()
 538         result = select(m_handle+1, &readset, NULL, NULL, &tv);
 539
 540         if(result == 0)
 541                 return false;
 542         else if(result < 0 && errno == EINTR)
 543                 return false;
 544         else if(result < 0)
 545         {
 546                 dstream << (int) m_handle << ": Select failed: "
 547                         << strerror(errno) << std::endl;
 548
 549 #ifdef _WIN32
 550                 int e = WSAGetLastError();
 551                 dstream << (int) m_handle << ": WSAGetLastError()="
 552                         << e << std::endl;
 553                 if(e == 10004 /* = WSAEINTR */)
 554                 {
 555                         dstream << "WARNING: Ignoring WSAEINTR." << std::endl;
 556                         return false;
 557                 }
 558 #endif
 559
 560                 throw SocketException("Select failed");
 561         }
 562         else if(FD_ISSET(m_handle, &readset) == false)
 563         {
 564                 // No data
 565                 return false;
 566         }
 567
 568         // There is data
 569         return true;
 570 }
 571
 572