src/gromacs/imd/imdsocket.cpp

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  35
  36 /*! \internal \file
  37  *
  38  * \brief
  39  * Implements functions of imdsocket.h.
  40  *
  41  * This file re-implements vmdsock.c functions from original IMD API from scratch,
  42  * see imdsocket.h for references to the IMD API.
  43  *
  44  * \author Martin Hoefling, Carsten Kutzner <ckutzne@gwdg.de>
  45  *
  46  * \ingroup module_imd
  47  */
  48
  49 #include "gmxpre.h"
  50
  51 #include "imdsocket.h"
  52
  53 #include "config.h"
  54
  55 #include <errno.h>
  56 #include <string.h>
  57
  58 #include "gromacs/imd/imd.h"
  59 #include "gromacs/utility/fatalerror.h"
  60 #include "gromacs/utility/smalloc.h"
  61
  62 #if GMX_NATIVE_WINDOWS
  63 #ifdef GMX_HAVE_WINSOCK
  64 /*! \brief Define socklen type on Windows. */
  65 typedef int socklen_t;
  66
  67 /*! \brief Define a function to initialize winsock. */
  68 extern int imdsock_winsockinit()
  69 {
  70     int ret = -1;
  71
  72
  73     WSADATA wsd;
  74
  75     /* We use winsock 1.1 compatibility for now. Though I guess no one will try on Windows 95. */
  76     ret = WSAStartup(MAKEWORD(1, 1), &wsd);
  77     return ret;
  78 }
  79 #endif
  80 #else
  81 /* On UNIX, we can use nice errors from errno.h */
  82 #include <unistd.h>
  83 #ifdef GMX_IMD
  84 #include <time.h>
  85
  86 #include <sys/select.h>
  87 #include <sys/time.h>
  88 #endif
  89 #endif
  90
  91
  92 /*! \brief Simple error handling. */
  93 #if GMX_NATIVE_WINDOWS
  94 #define ERR_ARGS __FILE__, __LINE__, NULL
  95 #else
  96 #define ERR_ARGS __FILE__, __LINE__, strerror(errno)
  97 #endif
  98
  99
 100 /*! \brief Currently only 1 client connection is supported. */
 101 #define MAXIMDCONNECTIONS 1
 102
 103
 104 /*! \brief Print a nice error message on UNIX systems, using errno.h. */
 105 static void print_IMD_error(const char *file, int line, char *msg)
 106 {
 107     fprintf(stderr, "%s Error in file %s on line %d.\n", IMDstr, file, line);
 108
 109     if (nullptr != msg)
 110     {
 111         fprintf(stderr, "%s\n", msg);
 112     }
 113 }
 114
 115 /*! \brief Byte swap in case we are little-endian */
 116 static uint16_t gmx_htons(uint16_t src)
 117 {
 118     uint16_t num = 1;
 119
 120     if (*(char *)&num == 1)
 121     {
 122         return src;
 123     }
 124     else
 125     {
 126         uint16_t dest = 0;
 127
 128         dest |= (src & 0x0000FF00) >> 8;
 129         dest |= (src & 0x000000FF) << 8;
 130
 131         return dest;
 132     }
 133 }
 134
 135 /*! \brief Byte-unswap 16 bit word in case we are little-endian */
 136 static uint16_t gmx_ntohs(uint16_t src)
 137 {
 138     return gmx_htons(src);
 139 }
 140
 141
 142 extern IMDSocket* imdsock_create()
 143 {
 144     IMDSocket *sock = nullptr;
 145
 146
 147 #ifdef GMX_IMD
 148     snew(sock, 1);
 149     /* Try to create socket: */
 150     if ((sock->sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1)
 151     {
 152         print_IMD_error(ERR_ARGS);
 153         sfree(sock);
 154
 155         return nullptr;
 156     }
 157     else
 158 #endif
 159     {
 160         return sock;
 161     }
 162 }
 163
 164
 165 extern int imdsock_bind(IMDSocket *sock, int port)
 166 {
 167     int ret;
 168
 169
 170 #ifdef GMX_IMD
 171     memset(&(sock->address), 0, sizeof(sock->address));
 172     sock->address.sin_family = PF_INET;
 173     sock->address.sin_port   = gmx_htons(port);
 174
 175     /* Try to bind to address and port ...*/
 176     ret = bind(sock->sockfd, (struct sockaddr *) &sock->address, sizeof(sock->address));
 177 #else
 178     ret = -1;
 179 #endif
 180
 181     if (ret)
 182     {
 183         print_IMD_error(ERR_ARGS);
 184     }
 185
 186     return ret;
 187 }
 188
 189
 190 extern int imd_sock_listen(IMDSocket *sock)
 191 {
 192     int ret;
 193
 194
 195 #ifdef GMX_IMD
 196     /* Try to set to listening state */
 197     ret = listen(sock->sockfd, MAXIMDCONNECTIONS);
 198 #else
 199     ret = -1;
 200 #endif
 201
 202     if (ret)
 203     {
 204         print_IMD_error(ERR_ARGS);
 205     }
 206
 207     return ret;
 208 }
 209
 210
 211 extern IMDSocket* imdsock_accept(IMDSocket *sock)
 212 {
 213     int       ret;
 214
 215 #ifdef GMX_IMD
 216     socklen_t length;
 217
 218
 219     length = sizeof(sock->address);
 220     ret    = accept(sock->sockfd, (struct sockaddr *) &sock->address, &length);
 221
 222     /* successful, redirect to distinct clientsocket */
 223     if (ret >= 0)
 224     {
 225         IMDSocket *newsock;
 226
 227         snew(newsock, 1);
 228         newsock->address    = sock->address;
 229         newsock->sockfd     = ret;
 230
 231         return newsock;
 232     }
 233     else
 234 #endif
 235     {
 236         print_IMD_error(ERR_ARGS);
 237
 238         return nullptr;
 239     }
 240 }
 241
 242
 243 extern int imdsock_getport(IMDSocket *sock, int *port)
 244 {
 245     int                ret;
 246 #ifdef GMX_IMD
 247     socklen_t          len;
 248
 249
 250     len = sizeof(struct sockaddr_in);
 251     ret = getsockname(sock->sockfd, (struct sockaddr *) &(sock->address), &len);
 252     if (ret)
 253     {
 254         fprintf(stderr, "%s getsockname failed with error %d.\n", IMDstr, ret);
 255         print_IMD_error(ERR_ARGS);
 256     }
 257     else
 258     {
 259         *port = gmx_ntohs(sock->address.sin_port);
 260     }
 261 #else
 262     gmx_incons("imdsock_getport called without IMD support.");
 263     ret = -1;
 264 #endif
 265
 266     return ret;
 267 }
 268
 269
 270 extern int imdsock_write(IMDSocket *sock, const char *buffer, int length)
 271 {
 272     /* No read and write on windows, we have to use send and recv instead... */
 273 #if GMX_NATIVE_WINDOWS
 274 #ifdef GMX_HAVE_WINSOCK
 275     return send(sock->sockfd, (const char *) buffer, length, NOFLAGS);
 276 #else
 277     return -1;
 278 #endif
 279 #else
 280     return write(sock->sockfd, buffer, length);
 281 #endif
 282 }
 283
 284
 285 extern int imdsock_read(IMDSocket *sock, char *buffer, int length)
 286 {
 287     /* See above... */
 288 #if GMX_NATIVE_WINDOWS
 289 #ifdef GMX_HAVE_WINSOCK
 290     return recv(sock->sockfd, (char *) buffer, length, NOFLAGS);
 291 #else
 292     return -1;
 293 #endif
 294 #else
 295     return read(sock->sockfd, buffer, length);
 296 #endif
 297 }
 298
 299
 300 extern void imdsock_shutdown(IMDSocket *sock)
 301 {
 302     int ret = -1;
 303
 304
 305     /* is the socket already NULL? */
 306     if (sock == nullptr)
 307     {
 308         return;
 309     }
 310
 311 #ifdef GMX_IMD
 312     /* If not, try to properly shut down. */
 313     ret = shutdown(sock->sockfd, 1);
 314 #endif
 315
 316     if (ret == -1)
 317     {
 318         fprintf(stderr, "%s Failed to shutdown socket. Did the client already disconnect?\n", IMDstr);
 319         print_IMD_error(ERR_ARGS);
 320     }
 321 }
 322
 323
 324 extern int imdsock_destroy(IMDSocket *sock)
 325 {
 326     int ret = -1;
 327
 328
 329     if (sock == nullptr)
 330     {
 331         return 1;
 332     }
 333
 334 #if GMX_NATIVE_WINDOWS
 335     /* On Windows, this function is called closesocket */
 336 #ifdef GMX_HAVE_WINSOCK
 337     ret = closesocket(sock->sockfd);
 338 #endif
 339 #else
 340     ret = close(sock->sockfd);
 341 #endif
 342
 343     if (ret == -1)
 344     {
 345         sfree(sock);
 346         print_IMD_error(ERR_ARGS);
 347
 348         return 0;
 349     }
 350
 351     return 1;
 352 }
 353
 354
 355 extern int imdsock_tryread(IMDSocket *sock, int timeoutsec, int timeoutusec)
 356 {
 357     int             ret = -1;
 358
 359
 360 #ifdef GMX_IMD
 361     fd_set          readfds;
 362     /* Create new time structure with sec and usec. */
 363     struct timeval *tval;
 364
 365
 366     snew(tval, 1);
 367
 368     /* clear the set */
 369     FD_ZERO(&readfds);
 370     /* add the socket to the read set */
 371     FD_SET(sock->sockfd, &readfds);
 372
 373     /* set the timeout */
 374     tval->tv_sec  = timeoutsec;
 375     tval->tv_usec = timeoutusec;
 376     do
 377     {
 378         /* check the set for read readiness. */
 379         ret = select(sock->sockfd + 1, &readfds, nullptr, nullptr, tval);
 380         /* redo on system interrupt */
 381     }
 382     while (ret < 0 && errno == EINTR);
 383
 384     sfree(tval);
 385 #endif
 386
 387     if (ret < 0)
 388     {
 389         print_IMD_error(ERR_ARGS);
 390     }
 391
 392     return ret;
 393 }