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 #include <stdio.h>
  23 #include <iostream>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <sstream>
  28 #include <iomanip>
  29 #include "util/string.h"
  30 #include "util/numeric.h"
  31 #include "constants.h"
  32 #include "debug.h"
  33 #include "settings.h"
  34 #include "log.h"
  35
  36 #ifdef _WIN32
  37         #ifndef WIN32_LEAN_AND_MEAN
  38                 #define WIN32_LEAN_AND_MEAN
  39         #endif
  40         // Without this some of the network functions are not found on mingw
  41         #ifndef _WIN32_WINNT
  42                 #define _WIN32_WINNT 0x0501
  43         #endif
  44         #include <windows.h>
  45         #include <winsock2.h>
  46         #include <ws2tcpip.h>
  47         #define LAST_SOCKET_ERR() WSAGetLastError()
  48         typedef SOCKET socket_t;
  49         typedef int socklen_t;
  50 #else
  51         #include <sys/types.h>
  52         #include <sys/socket.h>
  53         #include <netinet/in.h>
  54         #include <fcntl.h>
  55         #include <netdb.h>
  56         #include <unistd.h>
  57         #include <arpa/inet.h>
  58         #define LAST_SOCKET_ERR() (errno)
  59         typedef int socket_t;
  60 #endif
  61
  62 // Set to true to enable verbose debug output
  63 bool socket_enable_debug_output = false;        // yuck
  64
  65 static bool g_sockets_initialized = false;
  66
  67 // Initialize sockets
  68 void sockets_init()
  69 {
  70 #ifdef _WIN32
  71         // Windows needs sockets to be initialized before use
  72         WSADATA WsaData;
  73         if(WSAStartup( MAKEWORD(2,2), &WsaData ) != NO_ERROR)
  74                 throw SocketException("WSAStartup failed");
  75 #endif
  76         g_sockets_initialized = true;
  77 }
  78
  79 void sockets_cleanup()
  80 {
  81 #ifdef _WIN32
  82         // On Windows, cleanup sockets after use
  83         WSACleanup();
  84 #endif
  85 }
  86
  87 /*
  88         Address
  89 */
  90
  91 Address::Address()
  92 {
  93         m_addr_family = 0;
  94         memset(&m_address, 0, sizeof(m_address));
  95         m_port = 0;
  96 }
  97
  98 Address::Address(u32 address, u16 port)
  99 {
 100         memset(&m_address, 0, sizeof(m_address));
 101         setAddress(address);
 102         setPort(port);
 103 }
 104
 105 Address::Address(u8 a, u8 b, u8 c, u8 d, u16 port)
 106 {
 107         memset(&m_address, 0, sizeof(m_address));
 108         setAddress(a, b, c, d);
 109         setPort(port);
 110 }
 111
 112 Address::Address(const IPv6AddressBytes *ipv6_bytes, u16 port)
 113 {
 114         memset(&m_address, 0, sizeof(m_address));
 115         setAddress(ipv6_bytes);
 116         setPort(port);
 117 }
 118
 119 // Equality (address family, address and port must be equal)
 120 bool Address::operator==(const Address &address)
 121 {
 122         if(address.m_addr_family != m_addr_family || address.m_port != m_port)
 123                 return false;
 124         else if(m_addr_family == AF_INET)
 125         {
 126                 return m_address.ipv4.sin_addr.s_addr ==
 127                        address.m_address.ipv4.sin_addr.s_addr;
 128         }
 129         else if(m_addr_family == AF_INET6)
 130         {
 131                 return memcmp(m_address.ipv6.sin6_addr.s6_addr,
 132                               address.m_address.ipv6.sin6_addr.s6_addr, 16) == 0;
 133         }
 134         else
 135                 return false;
 136 }
 137
 138 bool Address::operator!=(const Address &address)
 139 {
 140         return !(*this == address);
 141 }
 142
 143 void Address::Resolve(const char *name)
 144 {
 145         if (!name || name[0] == 0) {
 146                 if (m_addr_family == AF_INET) {
 147                         setAddress((u32) 0);
 148                 } else if (m_addr_family == AF_INET6) {
 149                         setAddress((IPv6AddressBytes*) 0);
 150                 }
 151                 return;
 152         }
 153
 154         struct addrinfo *resolved, hints;
 155         memset(&hints, 0, sizeof(hints));
 156
 157         // Setup hints
 158         hints.ai_socktype = 0;
 159         hints.ai_protocol = 0;
 160         hints.ai_flags    = 0;
 161         if(g_settings->getBool("enable_ipv6"))
 162         {
 163                 // AF_UNSPEC allows both IPv6 and IPv4 addresses to be returned
 164                 hints.ai_family = AF_UNSPEC;
 165         }
 166         else
 167         {
 168                 hints.ai_family = AF_INET;
 169         }
 170
 171         // Do getaddrinfo()
 172         int e = getaddrinfo(name, NULL, &hints, &resolved);
 173         if(e != 0)
 174                 throw ResolveError(gai_strerror(e));
 175
 176         // Copy data
 177         if(resolved->ai_family == AF_INET)
 178         {
 179                 struct sockaddr_in *t = (struct sockaddr_in *) resolved->ai_addr;
 180                 m_addr_family = AF_INET;
 181                 m_address.ipv4 = *t;
 182         }
 183         else if(resolved->ai_family == AF_INET6)
 184         {
 185                 struct sockaddr_in6 *t = (struct sockaddr_in6 *) resolved->ai_addr;
 186                 m_addr_family = AF_INET6;
 187                 m_address.ipv6 = *t;
 188         }
 189         else
 190         {
 191                 freeaddrinfo(resolved);
 192                 throw ResolveError("");
 193         }
 194         freeaddrinfo(resolved);
 195 }
 196
 197 // IP address -> textual representation
 198 std::string Address::serializeString() const
 199 {
 200 // windows XP doesnt have inet_ntop, maybe use better func
 201 #ifdef _WIN32
 202         if(m_addr_family == AF_INET)
 203         {
 204                 u8 a, b, c, d;
 205                 u32 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                 *s << "[" << serializeString() << "]:" << m_port;
 309         else
 310                 *s << serializeString() << ":" << m_port;
 311 }
 312
 313 /*
 314         UDPSocket
 315 */
 316
 317 UDPSocket::UDPSocket(bool ipv6)
 318 {
 319         init(ipv6, false);
 320 }
 321
 322 bool UDPSocket::init(bool ipv6, bool noExceptions)
 323 {
 324         if (g_sockets_initialized == false) {
 325                 dstream << "Sockets not initialized" << std::endl;
 326                 return false;
 327         }
 328
 329         // Use IPv6 if specified
 330         m_addr_family = ipv6 ? AF_INET6 : AF_INET;
 331         m_handle = socket(m_addr_family, SOCK_DGRAM, IPPROTO_UDP);
 332
 333         if (socket_enable_debug_output) {
 334                 dstream << "UDPSocket(" << (int) m_handle
 335                         << ")::UDPSocket(): ipv6 = "
 336                         << (ipv6 ? "true" : "false")
 337                         << std::endl;
 338         }
 339
 340         if (m_handle <= 0) {
 341                 if (noExceptions) {
 342                         return false;
 343                 } else {
 344                         throw SocketException(std::string("Failed to create socket: error ")
 345                                 + itos(LAST_SOCKET_ERR()));
 346                 }
 347         }
 348
 349         setTimeoutMs(0);
 350
 351         return true;
 352 }
 353
 354
 355 UDPSocket::~UDPSocket()
 356 {
 357         if (socket_enable_debug_output) {
 358                 dstream << "UDPSocket( " << (int) m_handle << ")::~UDPSocket()"
 359                         << std::endl;
 360         }
 361
 362 #ifdef _WIN32
 363         closesocket(m_handle);
 364 #else
 365         close(m_handle);
 366 #endif
 367 }
 368
 369 void UDPSocket::Bind(Address addr)
 370 {
 371         if(socket_enable_debug_output) {
 372                 dstream << "UDPSocket(" << (int) m_handle << ")::Bind(): "
 373                         << addr.serializeString() << ":"
 374                         << addr.getPort() << std::endl;
 375         }
 376
 377         if (addr.getFamily() != m_addr_family) {
 378                 static const char *errmsg = "Socket and bind address families do not match";
 379                 errorstream << "Bind failed: " << errmsg << std::endl;
 380                 throw SocketException(errmsg);
 381         }
 382
 383         if(m_addr_family == AF_INET6) {
 384                 struct sockaddr_in6 address;
 385                 memset(&address, 0, sizeof(address));
 386
 387                 address             = addr.getAddress6();
 388                 address.sin6_family = AF_INET6;
 389                 address.sin6_port   = htons(addr.getPort());
 390
 391                 if(bind(m_handle, (const struct sockaddr *) &address,
 392                                 sizeof(struct sockaddr_in6)) < 0) {
 393                         dstream << (int) m_handle << ": Bind failed: "
 394                                 << strerror(errno) << std::endl;
 395                         throw SocketException("Failed to bind socket");
 396                 }
 397         } else {
 398                 struct sockaddr_in address;
 399                 memset(&address, 0, sizeof(address));
 400
 401                 address                 = addr.getAddress();
 402                 address.sin_family      = AF_INET;
 403                 address.sin_port        = htons(addr.getPort());
 404
 405                 if (bind(m_handle, (const struct sockaddr *) &address,
 406                                 sizeof(struct sockaddr_in)) < 0) {
 407                         dstream << (int)m_handle << ": Bind failed: "
 408                                 << strerror(errno) << std::endl;
 409                         throw SocketException("Failed to bind socket");
 410                 }
 411         }
 412 }
 413
 414 void UDPSocket::Send(const Address & destination, const void * data, int size)
 415 {
 416         bool dumping_packet = false; // for INTERNET_SIMULATOR
 417
 418         if(INTERNET_SIMULATOR)
 419                 dumping_packet = myrand() % INTERNET_SIMULATOR_PACKET_LOSS == 0;
 420
 421         if(socket_enable_debug_output) {
 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                         if(i % 2 == 0)
 431                                 dstream << " ";
 432                         unsigned int a = ((const unsigned char *)data)[i];
 433                         dstream << std::hex << std::setw(2) << std::setfill('0') << a;
 434                 }
 435
 436                 if(size > 20)
 437                         dstream << "...";
 438
 439                 if(dumping_packet)
 440                         dstream << " (DUMPED BY INTERNET_SIMULATOR)";
 441
 442                 dstream << std::endl;
 443         }
 444
 445         if(dumping_packet) {
 446                 // Lol let's forget it
 447                 dstream << "UDPSocket::Send(): INTERNET_SIMULATOR: dumping packet."
 448                                 << std::endl;
 449                 return;
 450         }
 451
 452         if(destination.getFamily() != m_addr_family)
 453                 throw SendFailedException("Address family mismatch");
 454
 455         int sent;
 456         if(m_addr_family == AF_INET6) {
 457                 struct sockaddr_in6 address = destination.getAddress6();
 458                 address.sin6_port = htons(destination.getPort());
 459                 sent = sendto(m_handle, (const char *)data, size,
 460                                 0, (struct sockaddr *)&address, sizeof(struct sockaddr_in6));
 461         } else {
 462                 struct sockaddr_in address = destination.getAddress();
 463                 address.sin_port = htons(destination.getPort());
 464                 sent = sendto(m_handle, (const char *)data, size,
 465                                 0, (struct sockaddr *)&address, sizeof(struct sockaddr_in));
 466         }
 467
 468         if(sent != size)
 469                 throw SendFailedException("Failed to send packet");
 470 }
 471
 472 int UDPSocket::Receive(Address & sender, void *data, int size)
 473 {
 474         // Return on timeout
 475         if(WaitData(m_timeout_ms) == false)
 476                 return -1;
 477
 478         int received;
 479         if (m_addr_family == AF_INET6) {
 480                 struct sockaddr_in6 address;
 481                 memset(&address, 0, sizeof(address));
 482                 socklen_t address_len = sizeof(address);
 483
 484                 received = recvfrom(m_handle, (char *) data,
 485                                 size, 0, (struct sockaddr *) &address, &address_len);
 486
 487                 if(received < 0)
 488                         return -1;
 489
 490                 u16 address_port = ntohs(address.sin6_port);
 491                 IPv6AddressBytes bytes;
 492                 memcpy(bytes.bytes, address.sin6_addr.s6_addr, 16);
 493                 sender = Address(&bytes, address_port);
 494         } else {
 495                 struct sockaddr_in address;
 496                 memset(&address, 0, sizeof(address));
 497
 498                 socklen_t address_len = sizeof(address);
 499
 500                 received = recvfrom(m_handle, (char *)data,
 501                                 size, 0, (struct sockaddr *)&address, &address_len);
 502
 503                 if(received < 0)
 504                         return -1;
 505
 506                 u32 address_ip = ntohl(address.sin_addr.s_addr);
 507                 u16 address_port = ntohs(address.sin_port);
 508
 509                 sender = Address(address_ip, address_port);
 510         }
 511
 512         if (socket_enable_debug_output) {
 513                 // Print packet sender and size
 514                 dstream << (int) m_handle << " <- ";
 515                 sender.print(&dstream);
 516                 dstream << ", size=" << received;
 517
 518                 // Print packet contents
 519                 dstream << ", data=";
 520                 for(int i = 0; i < received && i < 20; i++) {
 521                         if(i % 2 == 0)
 522                                 dstream << " ";
 523                         unsigned int a = ((const unsigned char *) data)[i];
 524                         dstream << std::hex << std::setw(2) << std::setfill('0') << a;
 525                 }
 526                 if(received > 20)
 527                         dstream << "...";
 528
 529                 dstream << std::endl;
 530         }
 531
 532         return received;
 533 }
 534
 535 int UDPSocket::GetHandle()
 536 {
 537         return m_handle;
 538 }
 539
 540 void UDPSocket::setTimeoutMs(int timeout_ms)
 541 {
 542         m_timeout_ms = timeout_ms;
 543 }
 544
 545 bool UDPSocket::WaitData(int timeout_ms)
 546 {
 547         fd_set readset;
 548         int result;
 549
 550         // Initialize the set
 551         FD_ZERO(&readset);
 552         FD_SET(m_handle, &readset);
 553
 554         // Initialize time out struct
 555         struct timeval tv;
 556         tv.tv_sec = 0;
 557         tv.tv_usec = timeout_ms * 1000;
 558
 559         // select()
 560         result = select(m_handle+1, &readset, NULL, NULL, &tv);
 561
 562         if (result == 0)
 563                 return false;
 564         else if (result < 0 && (errno == EINTR || errno == EBADF)) {
 565                 // N.B. select() fails when sockets are destroyed on Connection's dtor
 566                 // with EBADF.  Instead of doing tricky synchronization, allow this
 567                 // thread to exit but don't throw an exception.
 568                 return false;
 569         } else if (result < 0) {
 570                 dstream << (int) m_handle << ": Select failed: "
 571                         << strerror(errno) << std::endl;
 572
 573 #ifdef _WIN32
 574                 int e = WSAGetLastError();
 575                 dstream << (int) m_handle << ": WSAGetLastError()="
 576                         << e << std::endl;
 577                 if (e == 10004 /* WSAEINTR */ || e == 10009 /* WSAEBADF */) {
 578                         infostream << "Ignoring WSAEINTR/WSAEBADF." << std::endl;
 579                         return false;
 580                 }
 581 #endif
 582
 583                 throw SocketException("Select failed");
 584         } else if(FD_ISSET(m_handle, &readset) == false) {
 585                 // No data
 586                 return false;
 587         }
 588
 589         // There is data
 590         return true;
 591 }