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