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