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 "config.h"
  13
  14 #include <unistd.h>
  15 #include <string.h>
  16 #include <signal.h>
  17 #include <sys/ioctl.h>
  18 #include <sys/types.h>
  19 #include <sys/ipc.h>
  20 #include <sys/msg.h>
  21 #include <sys/wait.h>
  22 #include <errno.h>
  23 #ifdef __EMX__
  24 # include <sys/so_ioctl.h>
  25 #endif
  26 #ifdef HAVE_SYS_PARAM_H
  27 # include <sys/param.h>
  28 #endif
  29 #ifdef HAVE_SYS_FILIO_H
  30 # include <sys/filio.h>
  31 #endif
  32 #ifdef __svr4__
  33 # include <sys/file.h>
  34 #endif
  35
  36 #include "winsock.h"
  37 #include "windows.h"
  38 #include "heap.h"
  39 #include "ldt.h"
  40 #include "message.h"
  41 #include "selectors.h"
  42 #include "miscemu.h"
  43 #include "sig_context.h"
  44 #include "debug.h"
  45
  46 #ifndef FASYNC
  47 #define FASYNC FIOASYNC
  48 #endif
  49
  50 /* async DNS op control struct */
  51 typedef struct
  52 {
  53   ws_async_op*  ws_aop;
  54   char*         buffer;
  55   int           type;
  56   union
  57   {
  58     char*       init;
  59     char*       name;
  60     char*       addr;
  61   } rq;
  62   unsigned      ilength;
  63 } ws_async_ctl;
  64
  65 extern HANDLE16 __ws_gethandle( void* ptr );
  66 extern void*    __ws_memalloc( int size );
  67 extern void     __ws_memfree( void* ptr );
  68
  69 /* NOTE: ws_async_op list is traversed inside the SIGIO handler! */
  70
  71 static int              __async_io_max_fd = 0;
  72 static fd_set           __async_io_fdset;
  73 static ws_async_op*     __async_op_list = NULL;
  74
  75 static void fixup_wshe(struct ws_hostent* p_wshe, void* base);
  76 static void fixup_wspe(struct ws_protoent* p_wspe, void* base);
  77 static void fixup_wsse(struct ws_servent* p_wsse, void* base);
  78
  79 /* ----------------------------------- async/non-blocking I/O */
  80
  81 int WINSOCK_async_io(int fd, int async)
  82 {
  83     int fd_flags;
  84
  85 #ifndef __EMX__
  86     fcntl(fd, F_SETOWN, getpid());
  87 #endif
  88
  89     fd_flags = fcntl(fd, F_GETFL, 0);
  90     if (fcntl(fd, F_SETFL, (async)? fd_flags | FASYNC
  91                                   : fd_flags & ~FASYNC ) != -1) return 0;
  92     return -1;
  93 }
  94
  95 int WINSOCK_unblock_io(int fd, int noblock)
  96 {
  97     int fd_flags;
  98
  99     fd_flags = fcntl(fd, F_GETFL, 0);
 100     if (fcntl(fd, F_SETFL, (noblock)? fd_flags |  O_NONBLOCK
 101                                     : fd_flags & ~O_NONBLOCK ) != -1) return 0;
 102     return -1;
 103 }
 104
 105 int WINSOCK_check_async_op(ws_async_op* p_aop)
 106 {
 107   ws_async_op*   p = __async_op_list;
 108   while( p ) if( p == p_aop ) return 1;
 109              else p = p->next;
 110   return 0;
 111 }
 112
 113 int WINSOCK_cancel_async_op(ws_async_op* p_aop)
 114 {
 115     /* SIGIO unsafe! */
 116
 117     if( WINSOCK_check_async_op(p_aop) )
 118     {
 119         if( !(p_aop->flags & WSMSG_DEAD_AOP) )
 120         {
 121             kill(p_aop->pid, SIGKILL);
 122             waitpid(p_aop->pid, NULL, 0); /* just in case */
 123             close(p_aop->fd[0]);
 124         }
 125         WINSOCK_unlink_async_op(p_aop);
 126         EVENT_DeleteIO( p_aop->fd[0], EVENT_IO_READ );
 127         p_aop->flags = 0;
 128         p_aop->hWnd = p_aop->uMsg = 0;
 129         return 1;
 130     }
 131     return 0;
 132 }
 133
 134 void WINSOCK_cancel_task_aops(HTASK16 hTask, void (*__opfree)(void*))
 135 {
 136     /* SIGIO safe, hTask == 0 cancels all outstanding async ops */
 137
 138     int num = 0, num_dead = 0;
 139     ws_async_op*   p, *next;
 140
 141     TRACE(winsock," cancelling async DNS requests... \n");
 142
 143     SIGNAL_MaskAsyncEvents( TRUE );
 144     next = __async_op_list;
 145     while( (p = next) )
 146     {
 147         HTASK16 hWndTask = GetWindowTask16(p->hWnd);
 148
 149         next = p->next;
 150         if(!hTask || !hWndTask || (hTask == hWndTask))
 151         {
 152             num++;
 153             if( p->flags & WSMSG_DEAD_AOP )
 154                 num_dead++;
 155
 156             WINSOCK_cancel_async_op(p);
 157             if( __opfree ) __opfree(p);
 158         }
 159     }
 160     SIGNAL_MaskAsyncEvents( FALSE );
 161     TRACE(winsock," -> %i total (%i active)\n", num, num - num_dead );
 162 }
 163
 164 void WINSOCK_link_async_op(ws_async_op* p_aop)
 165 {
 166   /* SIGIO safe */
 167
 168   p_aop->prev = NULL;
 169   SIGNAL_MaskAsyncEvents( TRUE );
 170   if( __async_op_list )
 171   {
 172       ws_async_op*      p = __async_op_list;
 173       __async_op_list->prev = p_aop;
 174
 175       /* traverse the list and retire dead ops created
 176        * by the signal handler (see below). */
 177
 178       while( p )
 179       {
 180           if( p->flags & WSMSG_DEAD_AOP )
 181           {
 182               ws_async_op* dead = p;
 183
 184               TRACE(winsock,"\treaping dead aop [%08x]\n", (unsigned)p );
 185
 186               p = p->next;
 187               WINSOCK_unlink_async_op( dead );
 188               __ws_memfree( dead );
 189               continue;
 190           }
 191           p = p->next;
 192       }
 193   }
 194   else FD_ZERO(&__async_io_fdset);
 195   p_aop->next = __async_op_list;
 196   __async_op_list = p_aop;
 197   SIGNAL_MaskAsyncEvents( FALSE );
 198
 199   FD_SET(p_aop->fd[0], &__async_io_fdset);
 200   if( p_aop->fd[0] > __async_io_max_fd )
 201                      __async_io_max_fd = p_aop->fd[0];
 202 }
 203
 204 void WINSOCK_unlink_async_op(ws_async_op* p_aop)
 205 {
 206   /* SIGIO unsafe! */
 207
 208   if( p_aop == __async_op_list ) __async_op_list = p_aop->next;
 209   else
 210       p_aop->prev->next = p_aop->next;
 211   if( p_aop->next ) p_aop->next->prev = p_aop->prev;
 212
 213   FD_CLR(p_aop->fd[0], &__async_io_fdset);
 214   if( p_aop->fd[0] == __async_io_max_fd )
 215                       __async_io_max_fd--;
 216 }
 217
 218 /* ----------------------------------- SIGIO handler -
 219  *
 220  * link_async_op/unlink_async_op allow to install generic
 221  * async IO handlers (provided that aop_control function is defined).
 222  *
 223  * Note: pipe-based handlers must raise explicit SIGIO with kill(2).
 224  */
 225
 226 HANDLER_DEF(WINSOCK_sigio)
 227 {
 228  struct timeval         timeout;
 229  fd_set                 check_set;
 230  ws_async_op*           p_aop;
 231
 232  HANDLER_INIT();
 233
 234  check_set = __async_io_fdset;
 235  memset(&timeout, 0, sizeof(timeout));
 236
 237  while( select(__async_io_max_fd + 1,
 238               &check_set, NULL, NULL, &timeout) > 0)
 239  {
 240    for( p_aop = __async_op_list;
 241         p_aop ; p_aop = p_aop->next )
 242       if( FD_ISSET(p_aop->fd[0], &check_set) )
 243           if( p_aop->aop_control(p_aop, AOP_IO) == AOP_CONTROL_REMOVE )
 244           {
 245              /* NOTE: memory management is signal-unsafe, therefore
 246               * we can only set a flag to remove this p_aop later on.
 247               */
 248
 249               p_aop->flags = WSMSG_DEAD_AOP;
 250               close(p_aop->fd[0]);
 251               FD_CLR(p_aop->fd[0],&__async_io_fdset);
 252               if( p_aop->fd[0] == __async_io_max_fd )
 253                                  __async_io_max_fd = p_aop->fd[0];
 254               if( p_aop->pid )
 255               {
 256                   kill(p_aop->pid, SIGKILL);
 257                   waitpid(p_aop->pid, NULL, WNOHANG);
 258                   p_aop->pid = 0;
 259               }
 260           }
 261    check_set = __async_io_fdset;
 262   }
 263 }
 264
 265 /* ----------------------------------- getXbyY requests */
 266
 267 /* child process control struct */
 268 static   ws_async_ctl   async_ctl;
 269
 270 static int aop_control(ws_async_op* p_aop, int flag )
 271 {
 272     unsigned    lLength;
 273
 274   /* success:   LOWORD(lLength) has the length of the struct
 275    *            to read.
 276    * failure:   LOWORD(lLength) is zero, HIWORD(lLength) contains
 277    *            the error code.
 278    */
 279
 280     read(p_aop->fd[0], &lLength, sizeof(unsigned));
 281     if( LOWORD(lLength) )
 282     {
 283         if( (int)LOWORD(lLength) <= p_aop->buflen )
 284         {
 285             char* buffer = (p_aop->flags & WSMSG_WIN32_AOP)
 286                   ? p_aop->b.lin_base : (char*)PTR_SEG_TO_LIN(p_aop->b.seg_base);
 287
 288             read(p_aop->fd[0], buffer, LOWORD(lLength));
 289             switch( p_aop->flags & WSMSG_ASYNC_RQMASK )
 290             {
 291                 case WSMSG_ASYNC_HOSTBYNAME:
 292                 case WSMSG_ASYNC_HOSTBYADDR:
 293                      fixup_wshe((struct ws_hostent*)buffer, p_aop->b.ptr_base); break;
 294                 case WSMSG_ASYNC_PROTOBYNAME:
 295                 case WSMSG_ASYNC_PROTOBYNUM:
 296                      fixup_wspe((struct ws_protoent*)buffer, p_aop->b.ptr_base); break;
 297                 case WSMSG_ASYNC_SERVBYNAME:
 298                 case WSMSG_ASYNC_SERVBYPORT:
 299                      fixup_wsse((struct ws_servent*)buffer, p_aop->b.ptr_base); break;
 300                 default:
 301                      if( p_aop->flags ) WARN(winsock,"Received unknown async request!\n");
 302                      return AOP_CONTROL_REMOVE;
 303             }
 304         }
 305         else lLength =  ((UINT32)LOWORD(lLength)) | ((unsigned)WSAENOBUFS << 16);
 306     } /* failure */
 307
 308      /* was a __WS_ASYNC_DEBUG statement */
 309      TRACE(winsock, "DNS aop completed: hWnd [%04x], uMsg [%04x], "
 310           "aop [%04x], event [%08lx]\n",
 311           p_aop->hWnd, p_aop->uMsg, __ws_gethandle(p_aop), (LPARAM)lLength);
 312
 313     /* FIXME: update num_async_rq */
 314     EVENT_DeleteIO( p_aop->fd[0], EVENT_IO_READ );
 315     PostMessage32A( p_aop->hWnd, p_aop->uMsg, __ws_gethandle(p_aop), (LPARAM)lLength );
 316
 317     return AOP_CONTROL_REMOVE;  /* one-shot request */
 318 }
 319
 320
 321 HANDLE16 __WSAsyncDBQuery(LPWSINFO pwsi, HWND32 hWnd, UINT32 uMsg, INT32 type,
 322     LPCSTR init, INT32 len, LPCSTR proto, void* sbuf, INT32 buflen, UINT32 flag)
 323 {
 324     /* queue 'flag' request and fork off its handler */
 325
 326     async_ctl.ws_aop = (ws_async_op*)__ws_memalloc(sizeof(ws_async_op));
 327
 328     if( async_ctl.ws_aop )
 329     {
 330         HANDLE16        handle = __ws_gethandle(async_ctl.ws_aop);
 331
 332         if( pipe(async_ctl.ws_aop->fd) == 0 )
 333         {
 334             async_ctl.rq.init = (char*)init;
 335             async_ctl.ilength = len;
 336             async_ctl.buffer = (char*)proto;
 337             async_ctl.type = type;
 338
 339             async_ctl.ws_aop->hWnd = hWnd;
 340             async_ctl.ws_aop->uMsg = uMsg;
 341             async_ctl.ws_aop->b.ptr_base = sbuf;
 342             async_ctl.ws_aop->buflen = buflen;
 343             async_ctl.ws_aop->flags = flag;
 344             async_ctl.ws_aop->aop_control = &aop_control;
 345
 346             WINSOCK_link_async_op( async_ctl.ws_aop );
 347
 348             EVENT_AddIO( async_ctl.ws_aop->fd[0], EVENT_IO_READ );
 349             pwsi->num_async_rq++;
 350
 351             async_ctl.ws_aop->pid = fork();
 352             if( async_ctl.ws_aop->pid )
 353             {
 354                 TRACE(winsock, "\tasync_op = %04x (child %i)\n",
 355                                 handle, async_ctl.ws_aop->pid);
 356
 357                 close(async_ctl.ws_aop->fd[1]);  /* write endpoint */
 358                 if( async_ctl.ws_aop->pid > 0 )
 359                     return __ws_gethandle(async_ctl.ws_aop);
 360
 361                 /* fork() failed */
 362
 363                 pwsi->num_async_rq--;
 364                 EVENT_DeleteIO( async_ctl.ws_aop->fd[0], EVENT_IO_READ );
 365                 close(async_ctl.ws_aop->fd[0]);
 366                 pwsi->err = WSAEWOULDBLOCK;
 367             }
 368             else
 369             {
 370                 extern BOOL32 THREAD_InitDone;
 371
 372                 THREAD_InitDone = FALSE;
 373                 /* child process */
 374
 375                 close(async_ctl.ws_aop->fd[0]);  /* read endpoint */
 376                 switch( flag & WSMSG_ASYNC_RQMASK )
 377                 {
 378                     case WSMSG_ASYNC_HOSTBYADDR:
 379                     case WSMSG_ASYNC_HOSTBYNAME:
 380                         WS_do_async_gethost(pwsi, flag);
 381                         break;
 382                     case WSMSG_ASYNC_PROTOBYNUM:
 383                     case WSMSG_ASYNC_PROTOBYNAME:
 384                         WS_do_async_getproto(pwsi, flag);
 385                         break;
 386                     case WSMSG_ASYNC_SERVBYPORT:
 387                     case WSMSG_ASYNC_SERVBYNAME:
 388                         WS_do_async_getserv(pwsi, flag);
 389                         break;
 390                 }
 391                 _exit(0);       /* skip  atexit()'ed cleanup */
 392             }
 393         }
 394         else pwsi->err = wsaErrno(); /* failed to create pipe */
 395
 396         __ws_memfree((void*)async_ctl.ws_aop);
 397     } else pwsi->err = WSAEWOULDBLOCK;
 398     return 0;
 399 }
 400
 401 static int _async_notify()
 402 {
 403     /* use half-duplex pipe to send variable length packets
 404      * to the parent process */
 405
 406     write(async_ctl.ws_aop->fd[1], &async_ctl.ilength, sizeof(unsigned));
 407     write(async_ctl.ws_aop->fd[1], async_ctl.buffer, async_ctl.ilength );
 408
 409 #ifndef __EMX__
 410     kill(getppid(), SIGIO);    /* simulate async I/O */
 411 #endif
 412
 413     /* was a __WS_ASYNC_DEBUG statement */
 414     TRACE(winsock, "handler - notify aop [%d, buf %d]\n",
 415           async_ctl.ilength, async_ctl.ws_aop->buflen);
 416     return 1;
 417 }
 418
 419 static void _async_fail()
 420 {
 421      /* write a DWORD with error code (low word is zero) */
 422
 423      async_ctl.ilength =
 424         (h_errno < 0) ? (unsigned)WSAMAKEASYNCREPLY( 0, wsaErrno() )
 425                       : (unsigned)WSAMAKEASYNCREPLY( 0, wsaHerrno() );
 426      write(async_ctl.ws_aop->fd[1], &async_ctl.ilength, sizeof(unsigned) );
 427 #ifndef __EMX__
 428      kill(getppid(), SIGIO);    /* simulate async I/O */
 429 #endif
 430
 431     /* was a __WS_ASYNC_DEBUG statement */
 432     TRACE(winsock, "handler - failed aop [%d, buf %d]\n",
 433           async_ctl.ilength, async_ctl.ws_aop->buflen);
 434 }
 435
 436 void dump_ws_hostent_offset(struct ws_hostent* wshe)
 437 {
 438   int           i;
 439   char*         base = (char*)wshe;
 440   unsigned*     ptr;
 441
 442   DUMP("h_name = %08x\t[%s]\n",
 443        (unsigned)wshe->h_name, base + (unsigned)wshe->h_name);
 444   DUMP("h_aliases = %08x\t[%08x]\n",
 445        (unsigned)wshe->h_aliases, (unsigned)(base+(unsigned)wshe->h_aliases));
 446   ptr = (unsigned*)(base + (unsigned)wshe->h_aliases);
 447   for(i = 0; ptr[i]; i++ )
 448   {
 449         DUMP("%i - %08x [%s]\n", i + 1, ptr[i], ((char*)base) + ptr[i]);
 450   }
 451   DUMP("h_length = %i\n", wshe->h_length);
 452 }
 453
 454 void WS_do_async_gethost(LPWSINFO pwsi, unsigned flag )
 455 {
 456   int                   size = 0;
 457   struct hostent*       p_he;
 458
 459   close(async_ctl.ws_aop->fd[0]);
 460
 461   p_he = (flag & WSMSG_ASYNC_HOSTBYNAME)
 462          ? gethostbyname(async_ctl.rq.name)
 463          : gethostbyaddr(async_ctl.rq.name,
 464                          async_ctl.ilength, async_ctl.type);
 465
 466   TRACE(winsock,"DNS: got hostent for [%s]\n", async_ctl.rq.name );
 467
 468   if( p_he ) /* convert to the Winsock format with internal pointers as offsets */
 469       size = WS_dup_he(pwsi, p_he, WS_DUP_OFFSET |
 470                      ((flag & WSMSG_WIN32_AOP) ? WS_DUP_LINEAR : WS_DUP_SEGPTR) );
 471   if( size )
 472   {
 473       async_ctl.buffer = (char*)pwsi->he;
 474       async_ctl.ilength = (unsigned)WSAMAKEASYNCREPLY( (UINT16)size, 0 );
 475      _async_notify( flag );
 476   }
 477   else _async_fail();
 478 }
 479
 480 void WS_do_async_getproto(LPWSINFO pwsi, unsigned flag )
 481 {
 482   int                   size = 0;
 483   struct protoent*      p_pe;
 484
 485   close(async_ctl.ws_aop->fd[0]);
 486   p_pe = (flag & WSMSG_ASYNC_PROTOBYNAME)
 487          ? getprotobyname(async_ctl.rq.name)
 488          : getprotobynumber(async_ctl.type);
 489
 490   TRACE(winsock,"DNS: got protoent for [%s]\n", async_ctl.rq.name );
 491
 492   if( p_pe ) /* convert to the Winsock format with internal pointers as offsets */
 493       size = WS_dup_pe(pwsi, p_pe, WS_DUP_OFFSET |
 494                      ((flag & WSMSG_WIN32_AOP) ? WS_DUP_LINEAR : WS_DUP_SEGPTR) );
 495   if( size )
 496   {
 497       async_ctl.buffer = (char*)pwsi->pe;
 498       async_ctl.ilength = (unsigned)WSAMAKEASYNCREPLY( (UINT16)size, 0 );
 499      _async_notify( flag );
 500   }
 501   else _async_fail();
 502 }
 503
 504 void WS_do_async_getserv(LPWSINFO pwsi, unsigned flag )
 505 {
 506   int                   size = 0;
 507   struct servent*       p_se;
 508
 509   close(async_ctl.ws_aop->fd[0]);
 510   p_se = (flag & WSMSG_ASYNC_SERVBYNAME)
 511          ? getservbyname(async_ctl.rq.name, async_ctl.buffer)
 512          : getservbyport(async_ctl.type, async_ctl.buffer);
 513
 514   if( p_se ) /* convert to the Winsock format with internal pointers as offsets */
 515       size = WS_dup_se(pwsi, p_se, WS_DUP_OFFSET |
 516                       ((flag & WSMSG_WIN32_AOP) ? WS_DUP_LINEAR : WS_DUP_SEGPTR) );
 517   if( size )
 518   {
 519       async_ctl.buffer = (char*)pwsi->se;
 520       async_ctl.ilength = (unsigned)WSAMAKEASYNCREPLY( (UINT16)size, 0 );
 521      _async_notify( flag );
 522   }
 523   else _async_fail();
 524 }
 525
 526 /* ----------------------------------- helper functions -
 527  *
 528  * Raw results from the pipe contain internal pointers stored as
 529  * offsets relative to the beginning of the buffer and we need
 530  * to apply a fixup before passing them to applications.
 531  *
 532  * NOTE: It is possible to exploit the fact that fork() doesn't
 533  * change the buffer address by storing fixed up pointers right
 534  * in the handler. However, this will get in the way if we ever
 535  * get around to implementing DNS helper daemon a-la Netscape 4.x.
 536  */
 537
 538 void fixup_wshe(struct ws_hostent* p_wshe, void* base)
 539 {
 540    /* add 'base' to ws_hostent pointers to convert them from offsets */
 541
 542    int i;
 543    unsigned*    p_aliases,*p_addr;
 544
 545    p_aliases = (unsigned*)((char*)p_wshe + (unsigned)p_wshe->h_aliases);
 546    p_addr = (unsigned*)((char*)p_wshe + (unsigned)p_wshe->h_addr_list);
 547    ((unsigned)(p_wshe->h_name)) += (unsigned)base;
 548    ((unsigned)(p_wshe->h_aliases)) += (unsigned)base;
 549    ((unsigned)(p_wshe->h_addr_list)) += (unsigned)base;
 550    for(i=0;p_aliases[i];i++) p_aliases[i] += (unsigned)base;
 551    for(i=0;p_addr[i];i++) p_addr[i] += (unsigned)base;
 552 }
 553
 554 void fixup_wspe(struct ws_protoent* p_wspe, void* base)
 555 {
 556    int i;
 557    unsigned*       p_aliases = (unsigned*)((char*)p_wspe + (unsigned)p_wspe->p_aliases);
 558    ((unsigned)(p_wspe->p_name)) += (unsigned)base;
 559    ((unsigned)(p_wspe->p_aliases)) += (unsigned)base;
 560    for(i=0;p_aliases[i];i++) p_aliases[i] += (unsigned)base;
 561 }
 562
 563 void fixup_wsse(struct ws_servent* p_wsse, void* base)
 564 {
 565    int i;
 566    unsigned*       p_aliases = (unsigned*)((char*)p_wsse + (unsigned)p_wsse->s_aliases);
 567    ((unsigned)(p_wsse->s_name)) += (unsigned)base;
 568    ((p_wsse->s_proto)) += (unsigned)base;
 569    ((p_wsse->s_aliases)) += (unsigned)base;
 570    for(i=0;p_aliases[i];i++) p_aliases[i] += (unsigned)base;
 571 }