misc/winsock_dns.c

   1 /*
   2  * asynchronous DNS services
   3  *
   4  * (C) 1996,1997 Alex Korobka.
   5  *
   6  * TODO: Fork dns lookup helper during the startup (with a pipe
   7  *       for communication) and make it fork for a database request
   8  *       instead of forking the main process (i.e. something like
   9  *       Netscape 4.0).
  10  */
  11
  12 #include <unistd.h>
  13 #include <string.h>
  14 #include <signal.h>
  15 #include <sys/ioctl.h>
  16 #include <sys/types.h>
  17 #include <sys/ipc.h>
  18 #include <sys/msg.h>
  19 #include <sys/wait.h>
  20 #include <errno.h>
  21 #ifdef __EMX__
  22 #include <sys/so_ioctl.h>
  23 #include <sys/param.h>
  24 #endif
  25 #ifdef __svr4__
  26 #include <sys/file.h>
  27 #include <sys/filio.h>
  28 #endif
  29
  30 extern int h_errno;
  31
  32 #include "windows.h"
  33 #include "heap.h"
  34 #include "ldt.h"
  35 #include "message.h"
  36 #include "miscemu.h"
  37 #include "winsock.h"
  38 #include "debug.h"
  39
  40 #ifndef FASYNC
  41 #define FASYNC FIOASYNC
  42 #endif
  43
  44 #define __WS_ASYNC_DEBUG        0
  45
  46 typedef struct          /* async DNS op control struct */
  47 {
  48   ws_async_op*  ws_aop;
  49   char*         buffer;
  50   int           type;
  51   union
  52   {
  53     char*       init;
  54     char*       name;
  55     char*       addr;
  56   } rq;
  57   unsigned      ilength;
  58 } ws_async_ctl;
  59
  60 extern HANDLE16 __ws_gethandle( void* ptr );
  61 extern void*    __ws_memalloc( int size );
  62 extern void     __ws_memfree( void* ptr );
  63
  64 /* NOTE: ws_async_op list is traversed inside the SIGIO handler! */
  65
  66 static int              __async_io_max_fd = 0;
  67 static fd_set           __async_io_fdset;
  68 static ws_async_op*     __async_op_list = NULL;
  69
  70 static void fixup_wshe(struct ws_hostent* p_wshe, SEGPTR base);
  71 static void fixup_wspe(struct ws_protoent* p_wspe, SEGPTR base);
  72 static void fixup_wsse(struct ws_servent* p_wsse, SEGPTR base);
  73
  74 extern void EVENT_AddIO( int fd, unsigned flag );
  75 extern void EVENT_DeleteIO( int fd, unsigned flag );
  76
  77 /* ----------------------------------- async/non-blocking I/O */
  78
  79 int WINSOCK_async_io(int fd, int async)
  80 {
  81     int fd_flags;
  82
  83 #ifndef __EMX__
  84     fcntl(fd, F_SETOWN, getpid());
  85 #endif
  86
  87     fd_flags = fcntl(fd, F_GETFL, 0);
  88     if (fcntl(fd, F_SETFL, (async)? fd_flags | FASYNC
  89                                   : fd_flags & ~FASYNC ) != -1) return 0;
  90     return -1;
  91 }
  92
  93 int WINSOCK_unblock_io(int fd, int noblock)
  94 {
  95     int fd_flags;
  96
  97     fd_flags = fcntl(fd, F_GETFL, 0);
  98     if (fcntl(fd, F_SETFL, (noblock)? fd_flags |  O_NONBLOCK
  99                                     : fd_flags & ~O_NONBLOCK ) != -1) return 0;
 100     return -1;
 101 }
 102
 103 int WINSOCK_check_async_op(ws_async_op* p_aop)
 104 {
 105   ws_async_op*   p = __async_op_list;
 106   while( p ) if( p == p_aop ) return 1;
 107              else p = p->next;
 108   return 0;
 109 }
 110
 111 int WINSOCK_cancel_async_op(ws_async_op* p_aop)
 112 {
 113     /* SIGIO unsafe! */
 114
 115     if( WINSOCK_check_async_op(p_aop) )
 116     {
 117         if( !(p_aop->flags & WSMSG_DEAD_AOP) )
 118         {
 119             kill(p_aop->pid, SIGKILL);
 120             waitpid(p_aop->pid, NULL, 0); /* just in case */
 121             close(p_aop->fd[0]);
 122         }
 123         WINSOCK_unlink_async_op(p_aop);
 124         EVENT_DeleteIO( p_aop->fd[0], EVENT_IO_READ );
 125         p_aop->flags = 0;
 126         p_aop->hWnd = p_aop->uMsg = 0;
 127         return 1;
 128     }
 129     return 0;
 130 }
 131
 132 void WINSOCK_cancel_task_aops(HTASK16 hTask, void (*__opfree)(void*))
 133 {
 134     /* SIGIO safe, hTask == 0 cancels all outstanding async ops */
 135
 136     int num = 0;
 137     ws_async_op*   p, *next;
 138
 139     dprintf_winsock(stddeb,"\tcancelling async DNS requests... ");
 140
 141     SIGNAL_MaskAsyncEvents( TRUE );
 142     next = __async_op_list;
 143     while( (p = next) )
 144     {
 145         HTASK16 hWndTask = GetWindowTask16(p->hWnd);
 146
 147         next = p->next;
 148         if(!hTask || !hWndTask || (hTask == hWndTask))
 149         {
 150             WINSOCK_cancel_async_op(p);
 151             if( __opfree ) __opfree(p);
 152             num++;
 153         }
 154     }
 155     SIGNAL_MaskAsyncEvents( FALSE );
 156     dprintf_winsock(stddeb,"%i total\n", num );
 157 }
 158
 159 void WINSOCK_link_async_op(ws_async_op* p_aop)
 160 {
 161   /* SIGIO safe */
 162
 163   p_aop->prev = NULL;
 164   SIGNAL_MaskAsyncEvents( TRUE );
 165   if( __async_op_list )
 166   {
 167       ws_async_op*      p = __async_op_list;
 168       __async_op_list->prev = p_aop;
 169
 170       /* traverse the list and reap dead ops */
 171       while( p )
 172       {
 173           if( p->flags & WSMSG_DEAD_AOP )
 174           {
 175               ws_async_op* dead = p;
 176
 177               dprintf_winsock(stddeb,"\treaping dead aop [%08x]\n", (unsigned)p );
 178
 179               p = p->next;
 180               WINSOCK_unlink_async_op( dead );
 181               __ws_memfree( dead );
 182               continue;
 183           }
 184           p = p->next;
 185       }
 186   }
 187   else FD_ZERO(&__async_io_fdset);
 188   p_aop->next = __async_op_list;
 189   __async_op_list = p_aop;
 190   SIGNAL_MaskAsyncEvents( FALSE );
 191
 192   FD_SET(p_aop->fd[0], &__async_io_fdset);
 193   if( p_aop->fd[0] > __async_io_max_fd )
 194                      __async_io_max_fd = p_aop->fd[0];
 195 }
 196
 197 void WINSOCK_unlink_async_op(ws_async_op* p_aop)
 198 {
 199   /* SIGIO unsafe! */
 200
 201   if( p_aop == __async_op_list ) __async_op_list = p_aop->next;
 202   else
 203       p_aop->prev->next = p_aop->next;
 204   if( p_aop->next ) p_aop->next->prev = p_aop->prev;
 205
 206   FD_CLR(p_aop->fd[0], &__async_io_fdset);
 207   if( p_aop->fd[0] == __async_io_max_fd )
 208                       __async_io_max_fd--;
 209 }
 210
 211 /* ----------------------------------- SIGIO handler -
 212  *
 213  * link_async_op/unlink_async_op allow to install generic
 214  * async IO handlers (provided that aop_control function is defined).
 215  *
 216  * Note: AsyncGetXbyY expilicitly raise it.
 217  */
 218
 219 void WINSOCK_sigio(int signal)
 220 {
 221  struct timeval         timeout;
 222  fd_set                 check_set;
 223  ws_async_op*           p_aop;
 224
 225  check_set = __async_io_fdset;
 226  memset(&timeout, 0, sizeof(timeout));
 227
 228  while( select(__async_io_max_fd + 1,
 229               &check_set, NULL, NULL, &timeout) > 0)
 230  {
 231    for( p_aop = __async_op_list;
 232         p_aop ; p_aop = p_aop->next )
 233       if( FD_ISSET(p_aop->fd[0], &check_set) )
 234           if( p_aop->aop_control(p_aop, AOP_IO) == AOP_CONTROL_REMOVE )
 235           {
 236               p_aop->flags = WSMSG_DEAD_AOP;  /* can't free inside the signal */
 237               close(p_aop->fd[0]);
 238               FD_CLR(p_aop->fd[0],&__async_io_fdset);
 239               if( p_aop->fd[0] == __async_io_max_fd )
 240                                  __async_io_max_fd = p_aop->fd[0];
 241               if( p_aop->pid )
 242               {
 243                   kill(p_aop->pid, SIGKILL);
 244                   waitpid(p_aop->pid, NULL, WNOHANG);
 245                   p_aop->pid = 0;
 246               }
 247           }
 248    check_set = __async_io_fdset;
 249   }
 250 }
 251
 252 /* ----------------------------------- getXbyY requests */
 253
 254 static   ws_async_ctl   async_ctl; /* child process control struct */
 255
 256 static int aop_control(ws_async_op* p_aop, int flag )
 257 {
 258     unsigned    lLength;
 259
 260   /* success:   LOWORD(lLength) has the length of the struct
 261    *            to read.
 262    * failure:   LOWORD(lLength) is zero, HIWORD(lLength) contains
 263    *            the error code.
 264    */
 265
 266     read(p_aop->fd[0], &lLength, sizeof(unsigned));
 267     if( LOWORD(lLength) )
 268     {
 269         if( (int)LOWORD(lLength) <= p_aop->buflen )
 270         {
 271             char* buffer = (char*)PTR_SEG_TO_LIN(p_aop->buffer_base);
 272             read(p_aop->fd[0], buffer, LOWORD(lLength));
 273             switch( p_aop->flags )
 274             {
 275                 case WSMSG_ASYNC_HOSTBYNAME:
 276                 case WSMSG_ASYNC_HOSTBYADDR:
 277                      fixup_wshe((struct ws_hostent*)buffer, p_aop->buffer_base); break;
 278                 case WSMSG_ASYNC_PROTOBYNAME:
 279                 case WSMSG_ASYNC_PROTOBYNUM:
 280                      fixup_wspe((struct ws_protoent*)buffer, p_aop->buffer_base); break;
 281                 case WSMSG_ASYNC_SERVBYNAME:
 282                 case WSMSG_ASYNC_SERVBYPORT:
 283                      fixup_wsse((struct ws_servent*)buffer, p_aop->buffer_base); break;
 284                 default:
 285                      if( p_aop->flags ) fprintf(stderr,"Received unknown async request!\n");
 286                      return AOP_CONTROL_REMOVE;
 287             }
 288         }
 289         else lLength =  ((UINT32)LOWORD(lLength)) | ((unsigned)WSAENOBUFS << 16);
 290     } /* failure */
 291
 292 #if __WS_ASYNC_DEBUG
 293     printf("DNS aop completed: hWnd [%04x], uMsg [%04x], aop [%04x], event [%08x]\n",
 294          p_aop->hWnd, p_aop->uMsg, __ws_gethandle(p_aop), (LPARAM)lLength);
 295 #endif
 296
 297     /* FIXME: update num_async_rq */
 298     EVENT_DeleteIO( p_aop->fd[0], EVENT_IO_READ );
 299     PostMessage16( p_aop->hWnd, p_aop->uMsg, __ws_gethandle(p_aop), (LPARAM)lLength );
 300
 301     return AOP_CONTROL_REMOVE;  /* one-shot request */
 302 }
 303
 304
 305 HANDLE16 __WSAsyncDBQuery(LPWSINFO pwsi, HWND16 hWnd, UINT16 uMsg, INT16 type, LPSTR init,
 306                           INT16 len, LPSTR proto, SEGPTR sbuf, INT16 buflen, UINT32 flag)
 307 {
 308     /* queue 'flag' request and fork off its handler */
 309
 310     async_ctl.ws_aop = (ws_async_op*)__ws_memalloc(sizeof(ws_async_op));
 311
 312     if( async_ctl.ws_aop )
 313     {
 314         HANDLE16        handle = __ws_gethandle(async_ctl.ws_aop);
 315
 316         if( pipe(async_ctl.ws_aop->fd) == 0 )
 317         {
 318             async_ctl.rq.init = (char*)init;
 319             async_ctl.ilength = len;
 320             async_ctl.buffer = proto;
 321             async_ctl.type = type;
 322
 323             async_ctl.ws_aop->hWnd = hWnd;
 324             async_ctl.ws_aop->uMsg = uMsg;
 325             async_ctl.ws_aop->buffer_base = sbuf; async_ctl.ws_aop->buflen = buflen;
 326             async_ctl.ws_aop->flags = flag;
 327             async_ctl.ws_aop->aop_control = &aop_control;
 328
 329             WINSOCK_link_async_op( async_ctl.ws_aop );
 330
 331             async_ctl.ws_aop->pid = fork();
 332             if( async_ctl.ws_aop->pid )
 333             {
 334                 close(async_ctl.ws_aop->fd[1]);  /* write endpoint */
 335                 dprintf_winsock(stddeb, "\tasync_op = %04x (child %i)\n",
 336                                         handle, async_ctl.ws_aop->pid);
 337                 if( async_ctl.ws_aop->pid > 0 )
 338                 {
 339                     EVENT_AddIO( async_ctl.ws_aop->fd[0], EVENT_IO_READ );
 340                     pwsi->num_async_rq++;
 341                     return __ws_gethandle(async_ctl.ws_aop);
 342                 }
 343
 344                 /* fork() failed */
 345                 close(async_ctl.ws_aop->fd[0]);
 346                 pwsi->err = WSAEWOULDBLOCK;
 347             }
 348             else
 349             {
 350                 /* child process */
 351
 352                 close(async_ctl.ws_aop->fd[0]);  /* read endpoint */
 353                 switch( flag )
 354                 {
 355                     case WSMSG_ASYNC_HOSTBYADDR:
 356                     case WSMSG_ASYNC_HOSTBYNAME:
 357                         WS_do_async_gethost(pwsi, flag);
 358                         break;
 359                     case WSMSG_ASYNC_PROTOBYNUM:
 360                     case WSMSG_ASYNC_PROTOBYNAME:
 361                         WS_do_async_getproto(pwsi, flag);
 362                         break;
 363                     case WSMSG_ASYNC_SERVBYPORT:
 364                     case WSMSG_ASYNC_SERVBYNAME:
 365                         WS_do_async_getserv(pwsi, flag);
 366                         break;
 367                 }
 368                 _exit(0);       /* skip  atexit()'ed cleanup */
 369             }
 370         }
 371         else pwsi->err = wsaErrno(); /* failed to create pipe */
 372
 373         __ws_memfree((void*)async_ctl.ws_aop);
 374     } else pwsi->err = WSAEWOULDBLOCK;
 375     return 0;
 376 }
 377
 378 static int _async_notify()
 379 {
 380     /* use half-duplex pipe to send variable length packets
 381      * to the parent process */
 382
 383     write(async_ctl.ws_aop->fd[1], &async_ctl.ilength, sizeof(unsigned));
 384     write(async_ctl.ws_aop->fd[1], async_ctl.buffer, async_ctl.ilength );
 385
 386 #ifndef __EMX__
 387     kill(getppid(), SIGIO);    /* simulate async I/O */
 388 #endif
 389
 390 #if __WS_ASYNC_DEBUG
 391     printf("handler - notify aop [%d, buf %d]\n", async_ctl.ilength, async_ctl.ws_aop->buflen);
 392 #endif
 393     return 1;
 394 }
 395
 396 static void _async_fail()
 397 {
 398      /* write a DWORD with error code (low word is zero) */
 399
 400      async_ctl.ilength =
 401         (h_errno < 0) ? (unsigned)WSAMAKEASYNCREPLY( 0, wsaErrno() )
 402                       : (unsigned)WSAMAKEASYNCREPLY( 0, wsaHerrno() );
 403      write(async_ctl.ws_aop->fd[1], &async_ctl.ilength, sizeof(unsigned) );
 404 #ifndef __EMX__
 405      kill(getppid(), SIGIO);    /* simulate async I/O */
 406 #endif
 407
 408 #if __WS_ASYNC_DEBUG
 409     printf("handler - failed aop [%d, buf %d]\n", async_ctl.ilength, async_ctl.ws_aop->buflen);
 410 #endif
 411 }
 412
 413 void dump_ws_hostent_offset(struct ws_hostent* wshe)
 414 {
 415   int           i;
 416   char*         base = (char*)wshe;
 417   unsigned*     ptr;
 418
 419   printf("h_name = %08x\t[%s]\n", (unsigned)wshe->h_name, base + (unsigned)wshe->h_name);
 420   printf("h_aliases = %08x\t[%08x]\n", (unsigned)wshe->h_aliases,
 421                                        (unsigned)(base + (unsigned)wshe->h_aliases));
 422   ptr = (unsigned*)(base + (unsigned)wshe->h_aliases);
 423   for(i = 0; ptr[i]; i++ )
 424   {
 425         printf("%i - %08x ", i + 1, ptr[i]);
 426         printf(" [%s]\n", ((char*)base) + ptr[i]);
 427   }
 428   printf("h_length = %i\n", wshe->h_length);
 429 }
 430
 431 void WS_do_async_gethost(LPWSINFO pwsi, unsigned flag )
 432 {
 433   int                   size = 0;
 434   struct hostent*       p_he;
 435
 436   close(async_ctl.ws_aop->fd[0]);
 437
 438   dprintf_winsock(stddeb,"DNS: getting hostent for [%s]\n", async_ctl.rq.name );
 439
 440   p_he = (flag & WSMSG_ASYNC_HOSTBYNAME)
 441          ? gethostbyname(async_ctl.rq.name)
 442          : gethostbyaddr(async_ctl.rq.name,
 443                          async_ctl.ilength, async_ctl.type);
 444   dprintf_winsock(stddeb,"DNS: done!\n");
 445
 446   if( p_he ) size = WS_dup_he(pwsi, p_he, WS_DUP_SEGPTR | WS_DUP_OFFSET );
 447   if( size )
 448   {
 449      async_ctl.buffer = pwsi->buffer;
 450      async_ctl.ilength = (unsigned)WSAMAKEASYNCREPLY( (UINT16)size, 0 );
 451      _async_notify( flag );
 452   }
 453   else _async_fail();
 454 }
 455
 456 void WS_do_async_getproto(LPWSINFO pwsi, unsigned flag )
 457 {
 458   int                   size = 0;
 459   struct protoent*      p_pe;
 460
 461   close(async_ctl.ws_aop->fd[0]);
 462   p_pe = (flag & WSMSG_ASYNC_PROTOBYNAME)
 463          ? getprotobyname(async_ctl.rq.name)
 464          : getprotobynumber(async_ctl.type);
 465   if( p_pe ) size = WS_dup_pe(pwsi, p_pe, WS_DUP_SEGPTR | WS_DUP_OFFSET );
 466   if( size )
 467   {
 468      async_ctl.buffer = pwsi->buffer;
 469      async_ctl.ilength = (unsigned)WSAMAKEASYNCREPLY( (UINT16)size, 0 );
 470      _async_notify( flag );
 471   }
 472   else _async_fail();
 473 }
 474
 475 void WS_do_async_getserv(LPWSINFO pwsi, unsigned flag )
 476 {
 477   int                   size = 0;
 478   struct servent*       p_se;
 479
 480   close(async_ctl.ws_aop->fd[0]);
 481   p_se = (flag & WSMSG_ASYNC_SERVBYNAME)
 482          ? getservbyname(async_ctl.rq.name, async_ctl.buffer)
 483          : getservbyport(async_ctl.type, async_ctl.buffer);
 484   if( p_se ) size = WS_dup_se(pwsi, p_se, WS_DUP_SEGPTR | WS_DUP_OFFSET );
 485   if( size )
 486   {
 487      async_ctl.buffer = pwsi->buffer;
 488      async_ctl.ilength = (unsigned)WSAMAKEASYNCREPLY( (UINT16)size, 0 );
 489      _async_notify( flag );
 490   }
 491   else _async_fail();
 492 }
 493
 494 /* ----------------------------------- helper functions */
 495
 496 void fixup_wshe(struct ws_hostent* p_wshe, SEGPTR base)
 497 {
 498    /* add 'base' to ws_hostent pointers to convert them from offsets */
 499
 500    int i;
 501    unsigned*    p_aliases,*p_addr;
 502
 503    p_aliases = (unsigned*)((char*)p_wshe + (unsigned)p_wshe->h_aliases);
 504    p_addr = (unsigned*)((char*)p_wshe + (unsigned)p_wshe->h_addr_list);
 505    ((unsigned)(p_wshe->h_name)) += (unsigned)base;
 506    ((unsigned)(p_wshe->h_aliases)) += (unsigned)base;
 507    ((unsigned)(p_wshe->h_addr_list)) += (unsigned)base;
 508    for(i=0;p_aliases[i];i++) p_aliases[i] += (unsigned)base;
 509    for(i=0;p_addr[i];i++) p_addr[i] += (unsigned)base;
 510 }
 511
 512 void fixup_wspe(struct ws_protoent* p_wspe, SEGPTR base)
 513 {
 514    int i;
 515    unsigned*       p_aliases = (unsigned*)((char*)p_wspe + (unsigned)p_wspe->p_aliases);
 516    ((unsigned)(p_wspe->p_name)) += (unsigned)base;
 517    ((unsigned)(p_wspe->p_aliases)) += (unsigned)base;
 518    for(i=0;p_aliases[i];i++) p_aliases[i] += (unsigned)base;
 519 }
 520
 521 void fixup_wsse(struct ws_servent* p_wsse, SEGPTR base)
 522 {
 523    int i;
 524    unsigned*       p_aliases = (unsigned*)((char*)p_wsse + (unsigned)p_wsse->s_aliases);
 525    ((unsigned)(p_wsse->s_name)) += (unsigned)base;
 526    ((p_wsse->s_proto)) += (unsigned)base;
 527    ((p_wsse->s_aliases)) += (unsigned)base;
 528    for(i=0;p_aliases[i];i++) p_aliases[i] += (unsigned)base;
 529 }
 530