server/request.c

   1 /*
   2  * Server-side request handling
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  */
  20
  21 #include "config.h"
  22 #include "wine/port.h"
  23
  24 #include <assert.h>
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #ifdef HAVE_PWD_H
  28 #include <pwd.h>
  29 #endif
  30 #include <signal.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <stdarg.h>
  34 #include <string.h>
  35 #include <sys/stat.h>
  36 #include <sys/time.h>
  37 #include <sys/types.h>
  38 #ifdef HAVE_SYS_SOCKET_H
  39 # include <sys/socket.h>
  40 #endif
  41 #ifdef HAVE_SYS_WAIT_H
  42 # include <sys/wait.h>
  43 #endif
  44 #ifdef HAVE_SYS_UIO_H
  45 #include <sys/uio.h>
  46 #endif
  47 #ifdef HAVE_SYS_UN_H
  48 #include <sys/un.h>
  49 #endif
  50 #include <unistd.h>
  51 #ifdef HAVE_POLL_H
  52 #include <poll.h>
  53 #endif
  54 #ifdef __APPLE__
  55 # include <mach/mach_time.h>
  56 #endif
  57
  58 #include "ntstatus.h"
  59 #define WIN32_NO_STATUS
  60 #include "windef.h"
  61 #include "winbase.h"
  62 #include "wincon.h"
  63 #include "winternl.h"
  64 #include "wine/library.h"
  65
  66 #include "file.h"
  67 #include "process.h"
  68 #define WANT_REQUEST_HANDLERS
  69 #include "request.h"
  70
  71 /* Some versions of glibc don't define this */
  72 #ifndef SCM_RIGHTS
  73 #define SCM_RIGHTS 1
  74 #endif
  75
  76 /* path names for server master Unix socket */
  77 static const char * const server_socket_name = "socket";   /* name of the socket file */
  78 static const char * const server_lock_name = "lock";       /* name of the server lock file */
  79
  80 struct master_socket
  81 {
  82     struct object        obj;        /* object header */
  83     struct fd           *fd;         /* file descriptor of the master socket */
  84 };
  85
  86 static void master_socket_dump( struct object *obj, int verbose );
  87 static void master_socket_destroy( struct object *obj );
  88 static void master_socket_poll_event( struct fd *fd, int event );
  89
  90 static const struct object_ops master_socket_ops =
  91 {
  92     sizeof(struct master_socket),  /* size */
  93     master_socket_dump,            /* dump */
  94     no_get_type,                   /* get_type */
  95     no_add_queue,                  /* add_queue */
  96     NULL,                          /* remove_queue */
  97     NULL,                          /* signaled */
  98     NULL,                          /* satisfied */
  99     no_signal,                     /* signal */
 100     no_get_fd,                     /* get_fd */
 101     no_map_access,                 /* map_access */
 102     default_get_sd,                /* get_sd */
 103     default_set_sd,                /* set_sd */
 104     no_lookup_name,                /* lookup_name */
 105     no_open_file,                  /* open_file */
 106     no_close_handle,               /* close_handle */
 107     master_socket_destroy          /* destroy */
 108 };
 109
 110 static const struct fd_ops master_socket_fd_ops =
 111 {
 112     NULL,                          /* get_poll_events */
 113     master_socket_poll_event,      /* poll_event */
 114     NULL,                          /* flush */
 115     NULL,                          /* get_fd_type */
 116     NULL,                          /* ioctl */
 117     NULL,                          /* queue_async */
 118     NULL,                          /* reselect_async */
 119     NULL                           /* cancel_async */
 120 };
 121
 122
 123 struct thread *current = NULL;  /* thread handling the current request */
 124 unsigned int global_error = 0;  /* global error code for when no thread is current */
 125 timeout_t server_start_time = 0;  /* server startup time */
 126 int server_dir_fd = -1;    /* file descriptor for the server dir */
 127 int config_dir_fd = -1;    /* file descriptor for the config dir */
 128
 129 static struct master_socket *master_socket;  /* the master socket object */
 130 static struct timeout_user *master_timeout;
 131
 132 /* complain about a protocol error and terminate the client connection */
 133 void fatal_protocol_error( struct thread *thread, const char *err, ... )
 134 {
 135     va_list args;
 136
 137     va_start( args, err );
 138     fprintf( stderr, "Protocol error:%04x: ", thread->id );
 139     vfprintf( stderr, err, args );
 140     va_end( args );
 141     thread->exit_code = 1;
 142     kill_thread( thread, 1 );
 143 }
 144
 145 /* complain about a protocol error and terminate the client connection */
 146 void fatal_protocol_perror( struct thread *thread, const char *err, ... )
 147 {
 148     va_list args;
 149
 150     va_start( args, err );
 151     fprintf( stderr, "Protocol error:%04x: ", thread->id );
 152     vfprintf( stderr, err, args );
 153     perror( " " );
 154     va_end( args );
 155     thread->exit_code = 1;
 156     kill_thread( thread, 1 );
 157 }
 158
 159 /* die on a fatal error */
 160 void fatal_error( const char *err, ... )
 161 {
 162     va_list args;
 163
 164     va_start( args, err );
 165     fprintf( stderr, "wineserver: " );
 166     vfprintf( stderr, err, args );
 167     va_end( args );
 168     exit(1);
 169 }
 170
 171 /* die on a fatal error */
 172 void fatal_perror( const char *err, ... )
 173 {
 174     va_list args;
 175
 176     va_start( args, err );
 177     fprintf( stderr, "wineserver: " );
 178     vfprintf( stderr, err, args );
 179     perror( " " );
 180     va_end( args );
 181     exit(1);
 182 }
 183
 184 /* allocate the reply data */
 185 void *set_reply_data_size( data_size_t size )
 186 {
 187     assert( size <= get_reply_max_size() );
 188     if (size && !(current->reply_data = mem_alloc( size ))) size = 0;
 189     current->reply_size = size;
 190     return current->reply_data;
 191 }
 192
 193 /* write the remaining part of the reply */
 194 void write_reply( struct thread *thread )
 195 {
 196     int ret;
 197
 198     if ((ret = write( get_unix_fd( thread->reply_fd ),
 199                       (char *)thread->reply_data + thread->reply_size - thread->reply_towrite,
 200                       thread->reply_towrite )) >= 0)
 201     {
 202         if (!(thread->reply_towrite -= ret))
 203         {
 204             free( thread->reply_data );
 205             thread->reply_data = NULL;
 206             /* sent everything, can go back to waiting for requests */
 207             set_fd_events( thread->request_fd, POLLIN );
 208             set_fd_events( thread->reply_fd, 0 );
 209         }
 210         return;
 211     }
 212     if (errno == EPIPE)
 213         kill_thread( thread, 0 );  /* normal death */
 214     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 215         fatal_protocol_perror( thread, "reply write" );
 216 }
 217
 218 /* send a reply to the current thread */
 219 static void send_reply( union generic_reply *reply )
 220 {
 221     int ret;
 222
 223     if (!current->reply_size)
 224     {
 225         if ((ret = write( get_unix_fd( current->reply_fd ),
 226                           reply, sizeof(*reply) )) != sizeof(*reply)) goto error;
 227     }
 228     else
 229     {
 230         struct iovec vec[2];
 231
 232         vec[0].iov_base = (void *)reply;
 233         vec[0].iov_len  = sizeof(*reply);
 234         vec[1].iov_base = current->reply_data;
 235         vec[1].iov_len  = current->reply_size;
 236
 237         if ((ret = writev( get_unix_fd( current->reply_fd ), vec, 2 )) < sizeof(*reply)) goto error;
 238
 239         if ((current->reply_towrite = current->reply_size - (ret - sizeof(*reply))))
 240         {
 241             /* couldn't write it all, wait for POLLOUT */
 242             set_fd_events( current->reply_fd, POLLOUT );
 243             set_fd_events( current->request_fd, 0 );
 244             return;
 245         }
 246     }
 247     free( current->reply_data );
 248     current->reply_data = NULL;
 249     return;
 250
 251  error:
 252     if (ret >= 0)
 253         fatal_protocol_error( current, "partial write %d\n", ret );
 254     else if (errno == EPIPE)
 255         kill_thread( current, 0 );  /* normal death */
 256     else
 257         fatal_protocol_perror( current, "reply write" );
 258 }
 259
 260 /* call a request handler */
 261 static void call_req_handler( struct thread *thread )
 262 {
 263     union generic_reply reply;
 264     enum request req = thread->req.request_header.req;
 265
 266     current = thread;
 267     current->reply_size = 0;
 268     clear_error();
 269     memset( &reply, 0, sizeof(reply) );
 270
 271     if (debug_level) trace_request();
 272
 273     if (req < REQ_NB_REQUESTS)
 274         req_handlers[req]( &current->req, &reply );
 275     else
 276         set_error( STATUS_NOT_IMPLEMENTED );
 277
 278     if (current)
 279     {
 280         if (current->reply_fd)
 281         {
 282             reply.reply_header.error = current->error;
 283             reply.reply_header.reply_size = current->reply_size;
 284             if (debug_level) trace_reply( req, &reply );
 285             send_reply( &reply );
 286         }
 287         else
 288         {
 289             current->exit_code = 1;
 290             kill_thread( current, 1 );  /* no way to continue without reply fd */
 291         }
 292     }
 293     current = NULL;
 294 }
 295
 296 /* read a request from a thread */
 297 void read_request( struct thread *thread )
 298 {
 299     int ret;
 300
 301     if (!thread->req_toread)  /* no pending request */
 302     {
 303         if ((ret = read( get_unix_fd( thread->request_fd ), &thread->req,
 304                          sizeof(thread->req) )) != sizeof(thread->req)) goto error;
 305         if (!(thread->req_toread = thread->req.request_header.request_size))
 306         {
 307             /* no data, handle request at once */
 308             call_req_handler( thread );
 309             return;
 310         }
 311         if (!(thread->req_data = malloc( thread->req_toread )))
 312         {
 313             fatal_protocol_error( thread, "no memory for %u bytes request %d\n",
 314                                   thread->req_toread, thread->req.request_header.req );
 315             return;
 316         }
 317     }
 318
 319     /* read the variable sized data */
 320     for (;;)
 321     {
 322         ret = read( get_unix_fd( thread->request_fd ),
 323                     (char *)thread->req_data + thread->req.request_header.request_size
 324                       - thread->req_toread,
 325                     thread->req_toread );
 326         if (ret <= 0) break;
 327         if (!(thread->req_toread -= ret))
 328         {
 329             call_req_handler( thread );
 330             free( thread->req_data );
 331             thread->req_data = NULL;
 332             return;
 333         }
 334     }
 335
 336 error:
 337     if (!ret)  /* closed pipe */
 338         kill_thread( thread, 0 );
 339     else if (ret > 0)
 340         fatal_protocol_error( thread, "partial read %d\n", ret );
 341     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 342         fatal_protocol_perror( thread, "read" );
 343 }
 344
 345 /* receive a file descriptor on the process socket */
 346 int receive_fd( struct process *process )
 347 {
 348     struct iovec vec;
 349     struct send_fd data;
 350     struct msghdr msghdr;
 351     int fd = -1, ret;
 352
 353 #ifdef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 354     msghdr.msg_accrightslen = sizeof(int);
 355     msghdr.msg_accrights = (void *)&fd;
 356 #else  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 357     char cmsg_buffer[256];
 358     msghdr.msg_control    = cmsg_buffer;
 359     msghdr.msg_controllen = sizeof(cmsg_buffer);
 360     msghdr.msg_flags      = 0;
 361 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 362
 363     msghdr.msg_name    = NULL;
 364     msghdr.msg_namelen = 0;
 365     msghdr.msg_iov     = &vec;
 366     msghdr.msg_iovlen  = 1;
 367     vec.iov_base = (void *)&data;
 368     vec.iov_len  = sizeof(data);
 369
 370     ret = recvmsg( get_unix_fd( process->msg_fd ), &msghdr, 0 );
 371
 372 #ifndef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 373     if (ret > 0)
 374     {
 375         struct cmsghdr *cmsg;
 376         for (cmsg = CMSG_FIRSTHDR( &msghdr ); cmsg; cmsg = CMSG_NXTHDR( &msghdr, cmsg ))
 377         {
 378             if (cmsg->cmsg_level != SOL_SOCKET) continue;
 379             if (cmsg->cmsg_type == SCM_RIGHTS) fd = *(int *)CMSG_DATA(cmsg);
 380         }
 381     }
 382 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 383
 384     if (ret == sizeof(data))
 385     {
 386         struct thread *thread;
 387
 388         if (data.tid) thread = get_thread_from_id( data.tid );
 389         else thread = (struct thread *)grab_object( get_process_first_thread( process ));
 390
 391         if (!thread || thread->process != process || thread->state == TERMINATED)
 392         {
 393             if (debug_level)
 394                 fprintf( stderr, "%04x: *fd* %d <- %d bad thread id\n",
 395                          data.tid, data.fd, fd );
 396             close( fd );
 397         }
 398         else
 399         {
 400             if (debug_level)
 401                 fprintf( stderr, "%04x: *fd* %d <- %d\n",
 402                          thread->id, data.fd, fd );
 403             thread_add_inflight_fd( thread, data.fd, fd );
 404         }
 405         if (thread) release_object( thread );
 406         return 0;
 407     }
 408
 409     if (!ret)
 410     {
 411         kill_process( process, 0 );
 412     }
 413     else if (ret > 0)
 414     {
 415         fprintf( stderr, "Protocol error: process %04x: partial recvmsg %d for fd\n",
 416                  process->id, ret );
 417         if (fd != -1) close( fd );
 418         kill_process( process, 1 );
 419     }
 420     else
 421     {
 422         if (errno != EWOULDBLOCK && errno != EAGAIN)
 423         {
 424             fprintf( stderr, "Protocol error: process %04x: ", process->id );
 425             perror( "recvmsg" );
 426             kill_process( process, 1 );
 427         }
 428     }
 429     return -1;
 430 }
 431
 432 /* send an fd to a client */
 433 int send_client_fd( struct process *process, int fd, obj_handle_t handle )
 434 {
 435     struct iovec vec;
 436     struct msghdr msghdr;
 437     int ret;
 438
 439 #ifdef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 440     msghdr.msg_accrightslen = sizeof(fd);
 441     msghdr.msg_accrights = (void *)&fd;
 442 #else  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 443     char cmsg_buffer[256];
 444     struct cmsghdr *cmsg;
 445     msghdr.msg_control    = cmsg_buffer;
 446     msghdr.msg_controllen = sizeof(cmsg_buffer);
 447     msghdr.msg_flags      = 0;
 448     cmsg = CMSG_FIRSTHDR( &msghdr );
 449     cmsg->cmsg_len   = CMSG_LEN( sizeof(fd) );
 450     cmsg->cmsg_level = SOL_SOCKET;
 451     cmsg->cmsg_type  = SCM_RIGHTS;
 452     *(int *)CMSG_DATA(cmsg) = fd;
 453     msghdr.msg_controllen = cmsg->cmsg_len;
 454 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 455
 456     msghdr.msg_name    = NULL;
 457     msghdr.msg_namelen = 0;
 458     msghdr.msg_iov     = &vec;
 459     msghdr.msg_iovlen  = 1;
 460
 461     vec.iov_base = (void *)&handle;
 462     vec.iov_len  = sizeof(handle);
 463
 464     if (debug_level)
 465         fprintf( stderr, "%04x: *fd* %04x -> %d\n", current ? current->id : process->id, handle, fd );
 466
 467     ret = sendmsg( get_unix_fd( process->msg_fd ), &msghdr, 0 );
 468
 469     if (ret == sizeof(handle)) return 0;
 470
 471     if (ret >= 0)
 472     {
 473         fprintf( stderr, "Protocol error: process %04x: partial sendmsg %d\n", process->id, ret );
 474         kill_process( process, 1 );
 475     }
 476     else if (errno == EPIPE)
 477     {
 478         kill_process( process, 0 );
 479     }
 480     else
 481     {
 482         fprintf( stderr, "Protocol error: process %04x: ", process->id );
 483         perror( "sendmsg" );
 484         kill_process( process, 1 );
 485     }
 486     return -1;
 487 }
 488
 489 /* get current tick count to return to client */
 490 unsigned int get_tick_count(void)
 491 {
 492 #ifdef HAVE_CLOCK_GETTIME
 493     struct timespec ts;
 494 #ifdef CLOCK_MONOTONIC_RAW
 495     if (!clock_gettime( CLOCK_MONOTONIC_RAW, &ts ))
 496         return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
 497 #endif
 498     if (!clock_gettime( CLOCK_MONOTONIC, &ts ))
 499         return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
 500 #elif defined(__APPLE__)
 501     static mach_timebase_info_data_t timebase;
 502
 503     if (!timebase.denom) mach_timebase_info( &timebase );
 504     return mach_absolute_time() * timebase.numer / timebase.denom / 1000000;
 505 #endif
 506     return (current_time - server_start_time) / 10000;
 507 }
 508
 509 static void master_socket_dump( struct object *obj, int verbose )
 510 {
 511     struct master_socket *sock = (struct master_socket *)obj;
 512     assert( obj->ops == &master_socket_ops );
 513     fprintf( stderr, "Master socket fd=%p\n", sock->fd );
 514 }
 515
 516 static void master_socket_destroy( struct object *obj )
 517 {
 518     struct master_socket *sock = (struct master_socket *)obj;
 519     assert( obj->ops == &master_socket_ops );
 520     release_object( sock->fd );
 521 }
 522
 523 /* handle a socket event */
 524 static void master_socket_poll_event( struct fd *fd, int event )
 525 {
 526     struct master_socket *sock = get_fd_user( fd );
 527     assert( master_socket->obj.ops == &master_socket_ops );
 528
 529     assert( sock == master_socket );  /* there is only one master socket */
 530
 531     if (event & (POLLERR | POLLHUP))
 532     {
 533         /* this is not supposed to happen */
 534         fprintf( stderr, "wineserver: Error on master socket\n" );
 535         set_fd_events( sock->fd, -1 );
 536     }
 537     else if (event & POLLIN)
 538     {
 539         struct sockaddr_un dummy;
 540         socklen_t len = sizeof(dummy);
 541         int client = accept( get_unix_fd( master_socket->fd ), (struct sockaddr *) &dummy, &len );
 542         if (client == -1) return;
 543         fcntl( client, F_SETFL, O_NONBLOCK );
 544         create_process( client, NULL, 0 );
 545     }
 546 }
 547
 548 /* remove the socket upon exit */
 549 static void socket_cleanup(void)
 550 {
 551     static int do_it_once;
 552     if (!do_it_once++) unlink( server_socket_name );
 553 }
 554
 555 /* create a directory and check its permissions */
 556 static void create_dir( const char *name, struct stat *st )
 557 {
 558     if (lstat( name, st ) == -1)
 559     {
 560         if (errno != ENOENT) fatal_perror( "lstat %s", name );
 561         if (mkdir( name, 0700 ) == -1 && errno != EEXIST) fatal_perror( "mkdir %s", name );
 562         if (lstat( name, st ) == -1) fatal_perror( "lstat %s", name );
 563     }
 564     if (!S_ISDIR(st->st_mode)) fatal_error( "%s is not a directory\n", name );
 565     if (st->st_uid != getuid()) fatal_error( "%s is not owned by you\n", name );
 566     if (st->st_mode & 077) fatal_error( "%s must not be accessible by other users\n", name );
 567 }
 568
 569 /* create the server directory and chdir to it */
 570 static void create_server_dir( const char *dir )
 571 {
 572     char *p, *server_dir;
 573     struct stat st, st2;
 574
 575     if (!(server_dir = strdup( dir ))) fatal_error( "out of memory\n" );
 576
 577     /* first create the base directory if needed */
 578
 579     p = strrchr( server_dir, '/' );
 580     *p = 0;
 581     create_dir( server_dir, &st );
 582
 583     /* now create the server directory */
 584
 585     *p = '/';
 586     create_dir( server_dir, &st );
 587
 588     if (chdir( server_dir ) == -1) fatal_perror( "chdir %s", server_dir );
 589     if ((server_dir_fd = open( ".", O_RDONLY )) == -1) fatal_perror( "open %s", server_dir );
 590     if (fstat( server_dir_fd, &st2 ) == -1) fatal_perror( "stat %s", server_dir );
 591     if (st.st_dev != st2.st_dev || st.st_ino != st2.st_ino)
 592         fatal_error( "chdir did not end up in %s\n", server_dir );
 593
 594     free( server_dir );
 595 }
 596
 597 /* create the lock file and return its file descriptor */
 598 static int create_server_lock(void)
 599 {
 600     struct stat st;
 601     int fd;
 602
 603     if (lstat( server_lock_name, &st ) == -1)
 604     {
 605         if (errno != ENOENT)
 606             fatal_perror( "lstat %s/%s", wine_get_server_dir(), server_lock_name );
 607     }
 608     else
 609     {
 610         if (!S_ISREG(st.st_mode))
 611             fatal_error( "%s/%s is not a regular file\n", wine_get_server_dir(), server_lock_name );
 612     }
 613
 614     if ((fd = open( server_lock_name, O_CREAT|O_TRUNC|O_WRONLY, 0600 )) == -1)
 615         fatal_perror( "error creating %s/%s", wine_get_server_dir(), server_lock_name );
 616     return fd;
 617 }
 618
 619 /* wait for the server lock */
 620 int wait_for_lock(void)
 621 {
 622     const char *server_dir = wine_get_server_dir();
 623     int fd, r;
 624     struct flock fl;
 625
 626     if (!server_dir) return 0;  /* no server dir, so no lock to wait on */
 627
 628     create_server_dir( server_dir );
 629     fd = create_server_lock();
 630
 631     fl.l_type   = F_WRLCK;
 632     fl.l_whence = SEEK_SET;
 633     fl.l_start  = 0;
 634     fl.l_len    = 1;
 635     r = fcntl( fd, F_SETLKW, &fl );
 636     close(fd);
 637
 638     return r;
 639 }
 640
 641 /* kill the wine server holding the lock */
 642 int kill_lock_owner( int sig )
 643 {
 644     const char *server_dir = wine_get_server_dir();
 645     int fd, i, ret = 0;
 646     pid_t pid = 0;
 647     struct flock fl;
 648
 649     if (!server_dir) return 0;  /* no server dir, nothing to do */
 650
 651     create_server_dir( server_dir );
 652     fd = create_server_lock();
 653
 654     for (i = 1; i <= 20; i++)
 655     {
 656         fl.l_type   = F_WRLCK;
 657         fl.l_whence = SEEK_SET;
 658         fl.l_start  = 0;
 659         fl.l_len    = 1;
 660         if (fcntl( fd, F_GETLK, &fl ) == -1) goto done;
 661         if (fl.l_type != F_WRLCK) goto done;  /* the file is not locked */
 662         if (!pid)  /* first time around */
 663         {
 664             if (!(pid = fl.l_pid)) goto done;  /* shouldn't happen */
 665             if (sig == -1)
 666             {
 667                 if (kill( pid, SIGINT ) == -1) goto done;
 668                 kill( pid, SIGCONT );
 669                 ret = 1;
 670             }
 671             else  /* just send the specified signal and return */
 672             {
 673                 ret = (kill( pid, sig ) != -1);
 674                 goto done;
 675             }
 676         }
 677         else if (fl.l_pid != pid) goto done;  /* no longer the same process */
 678         usleep( 50000 * i );
 679     }
 680     /* waited long enough, now kill it */
 681     kill( pid, SIGKILL );
 682
 683  done:
 684     close( fd );
 685     return ret;
 686 }
 687
 688 /* acquire the main server lock */
 689 static void acquire_lock(void)
 690 {
 691     struct sockaddr_un addr;
 692     struct stat st;
 693     struct flock fl;
 694     int fd, slen, got_lock = 0;
 695
 696     fd = create_server_lock();
 697
 698     fl.l_type   = F_WRLCK;
 699     fl.l_whence = SEEK_SET;
 700     fl.l_start  = 0;
 701     fl.l_len    = 1;
 702     if (fcntl( fd, F_SETLK, &fl ) != -1)
 703     {
 704         /* check for crashed server */
 705         if (stat( server_socket_name, &st ) != -1 &&   /* there is a leftover socket */
 706             stat( "core", &st ) != -1 && st.st_size)   /* and there is a non-empty core file */
 707         {
 708             fprintf( stderr,
 709                      "Warning: a previous instance of the wine server seems to have crashed.\n"
 710                      "Please run 'gdb %s %s/core',\n"
 711                      "type 'backtrace' at the gdb prompt and report the results. Thanks.\n\n",
 712                      server_argv0, wine_get_server_dir() );
 713         }
 714         unlink( server_socket_name ); /* we got the lock, we can safely remove the socket */
 715         got_lock = 1;
 716         /* in that case we reuse fd without closing it, this ensures
 717          * that we hold the lock until the process exits */
 718     }
 719     else
 720     {
 721         switch(errno)
 722         {
 723         case ENOLCK:
 724             break;
 725         case EACCES:
 726             /* check whether locks work at all on this file system */
 727             if (fcntl( fd, F_GETLK, &fl ) == -1) break;
 728             /* fall through */
 729         case EAGAIN:
 730             exit(2); /* we didn't get the lock, exit with special status */
 731         default:
 732             fatal_perror( "fcntl %s/%s", wine_get_server_dir(), server_lock_name );
 733         }
 734         /* it seems we can't use locks on this fs, so we will use the socket existence as lock */
 735         close( fd );
 736     }
 737
 738     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 739     addr.sun_family = AF_UNIX;
 740     strcpy( addr.sun_path, server_socket_name );
 741     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 742 #ifdef HAVE_STRUCT_SOCKADDR_UN_SUN_LEN
 743     addr.sun_len = slen;
 744 #endif
 745     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 746     {
 747         if ((errno == EEXIST) || (errno == EADDRINUSE))
 748         {
 749             if (got_lock)
 750                 fatal_error( "couldn't bind to the socket even though we hold the lock\n" );
 751             exit(2); /* we didn't get the lock, exit with special status */
 752         }
 753         fatal_perror( "bind" );
 754     }
 755     atexit( socket_cleanup );
 756     chmod( server_socket_name, 0600 );  /* make sure no other user can connect */
 757     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 758
 759     if (!(master_socket = alloc_object( &master_socket_ops )) ||
 760         !(master_socket->fd = create_anonymous_fd( &master_socket_fd_ops, fd, &master_socket->obj, 0 )))
 761         fatal_error( "out of memory\n" );
 762     set_fd_events( master_socket->fd, POLLIN );
 763     make_object_static( &master_socket->obj );
 764 }
 765
 766 /* open the master server socket and start waiting for new clients */
 767 void open_master_socket(void)
 768 {
 769     const char *server_dir = wine_get_server_dir();
 770     const char *config_dir = wine_get_config_dir();
 771     int fd, pid, status, sync_pipe[2];
 772     char dummy;
 773
 774     /* make sure no request is larger than the maximum size */
 775     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 776     assert( sizeof(union generic_reply) == sizeof(struct request_max_size) );
 777
 778     /* make sure the stdio fds are open */
 779     fd = open( "/dev/null", O_RDWR );
 780     while (fd >= 0 && fd <= 2) fd = dup( fd );
 781
 782     if (!server_dir) fatal_error( "directory %s cannot be accessed\n", config_dir );
 783     if (chdir( config_dir ) == -1) fatal_perror( "chdir to %s", config_dir );
 784     if ((config_dir_fd = open( ".", O_RDONLY )) == -1) fatal_perror( "open %s", config_dir );
 785
 786     create_server_dir( server_dir );
 787
 788     if (!foreground)
 789     {
 790         if (pipe( sync_pipe ) == -1) fatal_perror( "pipe" );
 791         pid = fork();
 792         switch( pid )
 793         {
 794         case 0:  /* child */
 795             setsid();
 796             close( sync_pipe[0] );
 797
 798             acquire_lock();
 799
 800             /* close stdin and stdout */
 801             dup2( fd, 0 );
 802             dup2( fd, 1 );
 803
 804             /* signal parent */
 805             dummy = 0;
 806             write( sync_pipe[1], &dummy, 1 );
 807             close( sync_pipe[1] );
 808             break;
 809
 810         case -1:
 811             fatal_perror( "fork" );
 812             break;
 813
 814         default:  /* parent */
 815             close( sync_pipe[1] );
 816
 817             /* wait for child to signal us and then exit */
 818             if (read( sync_pipe[0], &dummy, 1 ) == 1) _exit(0);
 819
 820             /* child terminated, propagate exit status */
 821             waitpid( pid, &status, 0 );
 822             if (WIFEXITED(status)) _exit( WEXITSTATUS(status) );
 823             _exit(1);
 824         }
 825     }
 826     else  /* remain in the foreground */
 827     {
 828         acquire_lock();
 829     }
 830
 831     /* init the process tracing mechanism */
 832     init_tracing_mechanism();
 833     close( fd );
 834 }
 835
 836 /* master socket timer expiration handler */
 837 static void close_socket_timeout( void *arg )
 838 {
 839     master_timeout = NULL;
 840     flush_registry();
 841     if (debug_level) fprintf( stderr, "wineserver: exiting (pid=%ld)\n", (long) getpid() );
 842
 843 #ifdef DEBUG_OBJECTS
 844     close_objects();  /* shut down everything properly */
 845 #endif
 846     exit( 0 );
 847 }
 848
 849 /* close the master socket and stop waiting for new clients */
 850 void close_master_socket( timeout_t timeout )
 851 {
 852     if (master_socket)
 853     {
 854         release_object( master_socket );
 855         master_socket = NULL;
 856     }
 857     if (master_timeout)  /* cancel previous timeout */
 858         remove_timeout_user( master_timeout );
 859
 860     master_timeout = add_timeout_user( timeout, close_socket_timeout, NULL );
 861 }