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         memset(&m_address, 0, sizeof(m_address));
 102         setAddress(address);
 103         setPort(port);
 104 }
 105
 106 Address::Address(u8 a, u8 b, u8 c, u8 d, u16 port)
 107 {
 108         memset(&m_address, 0, sizeof(m_address));
 109         setAddress(a, b, c, d);
 110         setPort(port);
 111 }
 112
 113 Address::Address(const IPv6AddressBytes * ipv6_bytes, u16 port)
 114 {
 115         memset(&m_address, 0, sizeof(m_address));
 116         setAddress(ipv6_bytes);
 117         setPort(port);
 118 }
 119
 120 // Equality (address family, address and port must be equal)
 121 bool Address::operator==(Address &address)
 122 {
 123         if(address.m_addr_family != m_addr_family || address.m_port != m_port)
 124                 return false;
 125         else if(m_addr_family == AF_INET)
 126         {
 127                 return m_address.ipv4.sin_addr.s_addr ==
 128                        address.m_address.ipv4.sin_addr.s_addr;
 129         }
 130         else if(m_addr_family == AF_INET6)
 131         {
 132                 return memcmp(m_address.ipv6.sin6_addr.s6_addr,
 133                               address.m_address.ipv6.sin6_addr.s6_addr, 16) == 0;
 134         }
 135         else
 136                 return false;
 137 }
 138
 139 bool Address::operator!=(Address &address)
 140 {
 141         return !(*this == address);
 142 }
 143
 144 void Address::Resolve(const char *name)
 145 {
 146         if (!name || name[0] == 0) {
 147                 if (m_addr_family == AF_INET) {
 148                         setAddress((u32) 0);
 149                 } else if (m_addr_family == AF_INET6) {
 150                         setAddress((IPv6AddressBytes*) 0);
 151                 }
 152                 return;
 153         }
 154
 155         struct addrinfo *resolved, hints;
 156         memset(&hints, 0, sizeof(hints));
 157
 158         // Setup hints
 159         hints.ai_socktype = 0;
 160         hints.ai_protocol = 0;
 161         hints.ai_flags    = 0;
 162         if(g_settings->getBool("enable_ipv6"))
 163         {
 164                 // AF_UNSPEC allows both IPv6 and IPv4 addresses to be returned
 165                 hints.ai_family = AF_UNSPEC;
 166         }
 167         else
 168         {
 169                 hints.ai_family = AF_INET;
 170         }
 171
 172         // Do getaddrinfo()
 173         int e = getaddrinfo(name, NULL, &hints, &resolved);
 174         if(e != 0)
 175                 throw ResolveError(gai_strerror(e));
 176
 177         // Copy data
 178         if(resolved->ai_family == AF_INET)
 179         {
 180                 struct sockaddr_in *t = (struct sockaddr_in *) resolved->ai_addr;
 181                 m_addr_family = AF_INET;
 182                 m_address.ipv4 = *t;
 183         }
 184         else if(resolved->ai_family == AF_INET6)
 185         {
 186                 struct sockaddr_in6 *t = (struct sockaddr_in6 *) resolved->ai_addr;
 187                 m_addr_family = AF_INET6;
 188                 m_address.ipv6 = *t;
 189         }
 190         else
 191         {
 192                 freeaddrinfo(resolved);
 193                 throw ResolveError("");
 194         }
 195         freeaddrinfo(resolved);
 196 }
 197
 198 // IP address -> textual representation
 199 std::string Address::serializeString() const
 200 {
 201 // windows XP doesnt have inet_ntop, maybe use better func
 202 #ifdef _WIN32
 203         if(m_addr_family == AF_INET)
 204         {
 205                 u8 a, b, c, d, addr;
 206                 addr = ntohl(m_address.ipv4.sin_addr.s_addr);
 207                 a = (addr & 0xFF000000) >> 24;
 208                 b = (addr & 0x00FF0000) >> 16;
 209                 c = (addr & 0x0000FF00) >> 8;
 210                 d = (addr & 0x000000FF);
 211                 return itos(a) + "." + itos(b) + "." + itos(c) + "." + itos(d);
 212         }
 213         else if(m_addr_family == AF_INET6)
 214         {
 215                 std::ostringstream os;
 216                 for(int i = 0; i < 16; i += 2)
 217                 {
 218                         u16 section =
 219                         (m_address.ipv6.sin6_addr.s6_addr[i] << 8) |
 220                         (m_address.ipv6.sin6_addr.s6_addr[i + 1]);
 221                         os << std::hex << section;
 222                         if(i < 14)
 223                                 os << ":";
 224                 }
 225                 return os.str();
 226         }
 227         else
 228                 return std::string("");
 229 #else
 230         char str[INET6_ADDRSTRLEN];
 231         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) {
 232                 return std::string("");
 233         }
 234         return std::string(str);
 235 #endif
 236 }
 237
 238 struct sockaddr_in Address::getAddress() const
 239 {
 240         return m_address.ipv4; // NOTE: NO PORT INCLUDED, use getPort()
 241 }
 242
 243 struct sockaddr_in6 Address::getAddress6() const
 244 {
 245         return m_address.ipv6; // NOTE: NO PORT INCLUDED, use getPort()
 246 }
 247
 248 u16 Address::getPort() const
 249 {
 250         return m_port;
 251 }
 252
 253 int Address::getFamily() const
 254 {
 255         return m_addr_family;
 256 }
 257
 258 bool Address::isIPv6() const
 259 {
 260         return m_addr_family == AF_INET6;
 261 }
 262
 263 bool Address::isZero() const
 264 {
 265         if (m_addr_family == AF_INET) {
 266                 return m_address.ipv4.sin_addr.s_addr == 0;
 267         } else if (m_addr_family == AF_INET6) {
 268                 static const char zero[16] = {0};
 269                 return memcmp(m_address.ipv6.sin6_addr.s6_addr,
 270                               zero, 16) == 0;
 271         }
 272         return false;
 273 }
 274
 275 void Address::setAddress(u32 address)
 276 {
 277         m_addr_family = AF_INET;
 278         m_address.ipv4.sin_family = AF_INET;
 279         m_address.ipv4.sin_addr.s_addr = htonl(address);
 280 }
 281
 282 void Address::setAddress(u8 a, u8 b, u8 c, u8 d)
 283 {
 284         m_addr_family = AF_INET;
 285         m_address.ipv4.sin_family = AF_INET;
 286         u32 addr = htonl((a << 24) | (b << 16) | (c << 8) | d);
 287         m_address.ipv4.sin_addr.s_addr = addr;
 288 }
 289
 290 void Address::setAddress(const IPv6AddressBytes * ipv6_bytes)
 291 {
 292         m_addr_family = AF_INET6;
 293         m_address.ipv6.sin6_family = AF_INET6;
 294         if(ipv6_bytes)
 295                 memcpy(m_address.ipv6.sin6_addr.s6_addr, ipv6_bytes->bytes, 16);
 296         else
 297                 memset(m_address.ipv6.sin6_addr.s6_addr, 0, 16);
 298 }
 299
 300 void Address::setPort(u16 port)
 301 {
 302         m_port = port;
 303 }
 304
 305 void Address::print(std::ostream *s) const
 306 {
 307         if(m_addr_family == AF_INET6)
 308         {
 309                 (*s) << "[" << serializeString() << "]:" << m_port;
 310         }
 311         else
 312         {
 313                 (*s) << serializeString() << ":" << m_port;
 314         }
 315 }
 316
 317 /*
 318         UDPSocket
 319 */
 320
 321 UDPSocket::UDPSocket(bool ipv6)
 322 {
 323         if(g_sockets_initialized == false)
 324                 throw SocketException("Sockets not initialized");
 325
 326         // Use IPv6 if specified
 327         m_addr_family = ipv6 ? AF_INET6 : AF_INET;
 328         m_handle = socket(m_addr_family, SOCK_DGRAM, IPPROTO_UDP);
 329
 330         if(socket_enable_debug_output)
 331         {
 332                 dstream << "UDPSocket(" << (int) m_handle
 333                         << ")::UDPSocket(): ipv6 = "
 334                         << (ipv6 ? "true" : "false")
 335                         << std::endl;
 336         }
 337
 338         if(m_handle <= 0)
 339         {
 340                 throw SocketException("Failed to create socket");
 341         }
 342
 343         setTimeoutMs(0);
 344 }
 345
 346 UDPSocket::~UDPSocket()
 347 {
 348         if(socket_enable_debug_output)
 349         {
 350                 dstream << "UDPSocket( " << (int) m_handle << ")::~UDPSocket()"
 351                         << std::endl;
 352         }
 353
 354 #ifdef _WIN32
 355         closesocket(m_handle);
 356 #else
 357         close(m_handle);
 358 #endif
 359 }
 360
 361 void UDPSocket::Bind(Address addr)
 362 {
 363         if(socket_enable_debug_output)
 364         {
 365                 dstream << "UDPSocket(" << (int) m_handle << ")::Bind(): "
 366                         << addr.serializeString() << ":"
 367                         << addr.getPort() << std::endl;
 368         }
 369
 370         if (addr.getFamily() != m_addr_family)
 371         {
 372                 char errmsg[] = "Socket and bind address families do not match";
 373                 errorstream << "Bind failed: " << errmsg << std::endl;
 374                 throw SocketException(errmsg);
 375         }
 376
 377         if(m_addr_family == AF_INET6)
 378         {
 379                 struct sockaddr_in6 address;
 380                 memset(&address, 0, sizeof(address));
 381
 382                 address             = addr.getAddress6();
 383                 address.sin6_family = AF_INET6;
 384                 address.sin6_port   = htons(addr.getPort());
 385
 386                 if(bind(m_handle, (const struct sockaddr *) &address,
 387                                 sizeof(struct sockaddr_in6)) < 0)
 388                 {
 389                         dstream << (int) m_handle << ": Bind failed: "
 390                                 << strerror(errno) << std::endl;
 391                         throw SocketException("Failed to bind socket");
 392                 }
 393         }
 394         else
 395         {
 396                 struct sockaddr_in address;
 397                 memset(&address, 0, sizeof(address));
 398
 399                 address                 = addr.getAddress();
 400                 address.sin_family      = AF_INET;
 401                 address.sin_port        = htons(addr.getPort());
 402
 403                 if(bind(m_handle, (const struct sockaddr *) &address,
 404                         sizeof(struct sockaddr_in)) < 0)
 405                 {
 406                         dstream << (int) m_handle << ": Bind failed: "
 407                                 << strerror(errno) << std::endl;
 408                         throw SocketException("Failed to bind socket");
 409                 }
 410         }
 411 }
 412
 413 void UDPSocket::Send(const Address & destination, const void * data, int size)
 414 {
 415         bool dumping_packet = false; // for INTERNET_SIMULATOR
 416
 417         if(INTERNET_SIMULATOR)
 418                 dumping_packet = (myrand() % INTERNET_SIMULATOR_PACKET_LOSS == 0);
 419
 420         if(socket_enable_debug_output)
 421         {
 422                 // Print packet destination and size
 423                 dstream << (int) m_handle << " -> ";
 424                 destination.print(&dstream);
 425                 dstream << ", size=" << size;
 426
 427                 // Print packet contents
 428                 dstream << ", data=";
 429                 for(int i = 0; i < size && i < 20; i++)
 430                 {
 431                         if(i % 2 == 0)
 432                                 dstream << " ";
 433                         unsigned int a = ((const unsigned char *) data)[i];
 434                         dstream << std::hex << std::setw(2) << std::setfill('0')
 435                                 << a;
 436                 }
 437
 438                 if(size > 20)
 439                         dstream << "...";
 440
 441                 if(dumping_packet)
 442                         dstream << " (DUMPED BY INTERNET_SIMULATOR)";
 443
 444                 dstream << std::endl;
 445         }
 446
 447         if(dumping_packet)
 448         {
 449                 // Lol let's forget it
 450                 dstream << "UDPSocket::Send(): "
 451                                    "INTERNET_SIMULATOR: dumping packet."
 452                                 << std::endl;
 453                 return;
 454         }
 455
 456         if(destination.getFamily() != m_addr_family)
 457                 throw SendFailedException("Address family mismatch");
 458
 459         int sent;
 460         if(m_addr_family == AF_INET6)
 461         {
 462                 struct sockaddr_in6 address = destination.getAddress6();
 463                 address.sin6_port = htons(destination.getPort());
 464                 sent = sendto(m_handle, (const char *) data, size,
 465                         0, (struct sockaddr *) &address, sizeof(struct sockaddr_in6));
 466         }
 467         else
 468         {
 469                 struct sockaddr_in address = destination.getAddress();
 470                 address.sin_port = htons(destination.getPort());
 471                 sent = sendto(m_handle, (const char *) data, size,
 472                         0, (struct sockaddr *) &address, sizeof(struct sockaddr_in));
 473         }
 474
 475         if(sent != size)
 476         {
 477                 throw SendFailedException("Failed to send packet");
 478         }
 479 }
 480
 481 int UDPSocket::Receive(Address & sender, void * data, int size)
 482 {
 483         // Return on timeout
 484         if(WaitData(m_timeout_ms) == false)
 485         {
 486                 return -1;
 487         }
 488
 489         int received;
 490         if(m_addr_family == AF_INET6)
 491         {
 492                 struct sockaddr_in6 address;
 493                 memset(&address, 0, sizeof(address));
 494                 socklen_t address_len = sizeof(address);
 495
 496                 received = recvfrom(m_handle, (char *) data,
 497                                 size, 0, (struct sockaddr *) &address, &address_len);
 498
 499                 if(received < 0)
 500                         return -1;
 501
 502                 u16 address_port = ntohs(address.sin6_port);
 503                 IPv6AddressBytes bytes;
 504                 memcpy(bytes.bytes, address.sin6_addr.s6_addr, 16);
 505                 sender = Address(&bytes, address_port);
 506         }
 507         else
 508         {
 509                 struct sockaddr_in address;
 510                 memset(&address, 0, sizeof(address));
 511
 512                 socklen_t address_len = sizeof(address);
 513
 514                 received = recvfrom(m_handle, (char *) data,
 515                                 size, 0, (struct sockaddr *) &address, &address_len);
 516
 517                 if(received < 0)
 518                         return -1;
 519
 520                 u32 address_ip = ntohl(address.sin_addr.s_addr);
 521                 u16 address_port = ntohs(address.sin_port);
 522
 523                 sender = Address(address_ip, address_port);
 524         }
 525
 526         if(socket_enable_debug_output)
 527         {
 528                 // Print packet sender and size
 529                 dstream << (int) m_handle << " <- ";
 530                 sender.print(&dstream);
 531                 dstream << ", size=" << received;
 532
 533                 // Print packet contents
 534                 dstream << ", data=";
 535                 for(int i = 0; i < received && i < 20; i++)
 536                 {
 537                         if(i % 2 == 0)
 538                                 dstream << " ";
 539                         unsigned int a = ((const unsigned char *) data)[i];
 540                         dstream << std::hex << std::setw(2) << std::setfill('0')
 541                                 << a;
 542                 }
 543                 if(received > 20)
 544                         dstream << "...";
 545
 546                 dstream << std::endl;
 547         }
 548
 549         return received;
 550 }
 551
 552 int UDPSocket::GetHandle()
 553 {
 554         return m_handle;
 555 }
 556
 557 void UDPSocket::setTimeoutMs(int timeout_ms)
 558 {
 559         m_timeout_ms = timeout_ms;
 560 }
 561
 562 bool UDPSocket::WaitData(int timeout_ms)
 563 {
 564         fd_set readset;
 565         int result;
 566
 567         // Initialize the set
 568         FD_ZERO(&readset);
 569         FD_SET(m_handle, &readset);
 570
 571         // Initialize time out struct
 572         struct timeval tv;
 573         tv.tv_sec = 0;
 574         tv.tv_usec = timeout_ms * 1000;
 575
 576         // select()
 577         result = select(m_handle+1, &readset, NULL, NULL, &tv);
 578
 579         if(result == 0)
 580                 return false;
 581         else if(result < 0 && (errno == EINTR || errno == EBADF))
 582                 // N.B. select() fails when sockets are destroyed on Connection's dtor
 583                 // with EBADF.  Instead of doing tricky synchronization, allow this
 584                 // thread to exit but don't throw an exception.
 585                 return false;
 586         else if(result < 0)
 587         {
 588                 dstream << (int) m_handle << ": Select failed: "
 589                         << strerror(errno) << std::endl;
 590
 591 #ifdef _WIN32
 592                 int e = WSAGetLastError();
 593                 dstream << (int) m_handle << ": WSAGetLastError()="
 594                         << e << std::endl;
 595                 if(e == 10004 /* = WSAEINTR */ || e == 10009 /*WSAEBADF*/)
 596                 {
 597                         dstream << "WARNING: Ignoring WSAEINTR/WSAEBADF." << std::endl;
 598                         return false;
 599                 }
 600 #endif
 601
 602                 throw SocketException("Select failed");
 603         }
 604         else if(FD_ISSET(m_handle, &readset) == false)
 605         {
 606                 // No data
 607                 return false;
 608         }
 609
 610         // There is data
 611         return true;
 612 }