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
  55 #include "ntstatus.h"
  56 #define WIN32_NO_STATUS
  57 #include "windef.h"
  58 #include "winbase.h"
  59 #include "wincon.h"
  60 #include "winternl.h"
  61 #include "wine/library.h"
  62
  63 #include "file.h"
  64 #include "process.h"
  65 #define WANT_REQUEST_HANDLERS
  66 #include "request.h"
  67
  68 /* Some versions of glibc don't define this */
  69 #ifndef SCM_RIGHTS
  70 #define SCM_RIGHTS 1
  71 #endif
  72
  73 /* path names for server master Unix socket */
  74 static const char * const server_socket_name = "socket";   /* name of the socket file */
  75 static const char * const server_lock_name = "lock";       /* name of the server lock file */
  76
  77 struct master_socket
  78 {
  79     struct object        obj;        /* object header */
  80     struct fd           *fd;         /* file descriptor of the master socket */
  81 };
  82
  83 static void master_socket_dump( struct object *obj, int verbose );
  84 static void master_socket_destroy( struct object *obj );
  85 static void master_socket_poll_event( struct fd *fd, int event );
  86
  87 static const struct object_ops master_socket_ops =
  88 {
  89     sizeof(struct master_socket),  /* size */
  90     master_socket_dump,            /* dump */
  91     no_get_type,                   /* get_type */
  92     no_add_queue,                  /* add_queue */
  93     NULL,                          /* remove_queue */
  94     NULL,                          /* signaled */
  95     NULL,                          /* satisfied */
  96     no_signal,                     /* signal */
  97     no_get_fd,                     /* get_fd */
  98     no_map_access,                 /* map_access */
  99     default_get_sd,                /* get_sd */
 100     default_set_sd,                /* set_sd */
 101     no_lookup_name,                /* lookup_name */
 102     no_open_file,                  /* open_file */
 103     no_close_handle,               /* close_handle */
 104     master_socket_destroy          /* destroy */
 105 };
 106
 107 static const struct fd_ops master_socket_fd_ops =
 108 {
 109     NULL,                          /* get_poll_events */
 110     master_socket_poll_event,      /* poll_event */
 111     NULL,                          /* flush */
 112     NULL,                          /* get_fd_type */
 113     NULL,                          /* ioctl */
 114     NULL,                          /* queue_async */
 115     NULL,                          /* reselect_async */
 116     NULL                           /* cancel_async */
 117 };
 118
 119
 120 struct thread *current = NULL;  /* thread handling the current request */
 121 unsigned int global_error = 0;  /* global error code for when no thread is current */
 122 timeout_t server_start_time = 0;  /* server startup time */
 123 int server_dir_fd = -1;    /* file descriptor for the server dir */
 124 int config_dir_fd = -1;    /* file descriptor for the config dir */
 125
 126 static struct master_socket *master_socket;  /* the master socket object */
 127 static struct timeout_user *master_timeout;
 128
 129 /* complain about a protocol error and terminate the client connection */
 130 void fatal_protocol_error( struct thread *thread, const char *err, ... )
 131 {
 132     va_list args;
 133
 134     va_start( args, err );
 135     fprintf( stderr, "Protocol error:%04x: ", thread->id );
 136     vfprintf( stderr, err, args );
 137     va_end( args );
 138     thread->exit_code = 1;
 139     kill_thread( thread, 1 );
 140 }
 141
 142 /* complain about a protocol error and terminate the client connection */
 143 void fatal_protocol_perror( struct thread *thread, const char *err, ... )
 144 {
 145     va_list args;
 146
 147     va_start( args, err );
 148     fprintf( stderr, "Protocol error:%04x: ", thread->id );
 149     vfprintf( stderr, err, args );
 150     perror( " " );
 151     va_end( args );
 152     thread->exit_code = 1;
 153     kill_thread( thread, 1 );
 154 }
 155
 156 /* die on a fatal error */
 157 void fatal_error( const char *err, ... )
 158 {
 159     va_list args;
 160
 161     va_start( args, err );
 162     fprintf( stderr, "wineserver: " );
 163     vfprintf( stderr, err, args );
 164     va_end( args );
 165     exit(1);
 166 }
 167
 168 /* die on a fatal error */
 169 void fatal_perror( const char *err, ... )
 170 {
 171     va_list args;
 172
 173     va_start( args, err );
 174     fprintf( stderr, "wineserver: " );
 175     vfprintf( stderr, err, args );
 176     perror( " " );
 177     va_end( args );
 178     exit(1);
 179 }
 180
 181 /* allocate the reply data */
 182 void *set_reply_data_size( data_size_t size )
 183 {
 184     assert( size <= get_reply_max_size() );
 185     if (size && !(current->reply_data = mem_alloc( size ))) size = 0;
 186     current->reply_size = size;
 187     return current->reply_data;
 188 }
 189
 190 /* write the remaining part of the reply */
 191 void write_reply( struct thread *thread )
 192 {
 193     int ret;
 194
 195     if ((ret = write( get_unix_fd( thread->reply_fd ),
 196                       (char *)thread->reply_data + thread->reply_size - thread->reply_towrite,
 197                       thread->reply_towrite )) >= 0)
 198     {
 199         if (!(thread->reply_towrite -= ret))
 200         {
 201             free( thread->reply_data );
 202             thread->reply_data = NULL;
 203             /* sent everything, can go back to waiting for requests */
 204             set_fd_events( thread->request_fd, POLLIN );
 205             set_fd_events( thread->reply_fd, 0 );
 206         }
 207         return;
 208     }
 209     if (errno == EPIPE)
 210         kill_thread( thread, 0 );  /* normal death */
 211     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 212         fatal_protocol_perror( thread, "reply write" );
 213 }
 214
 215 /* send a reply to the current thread */
 216 static void send_reply( union generic_reply *reply )
 217 {
 218     int ret;
 219
 220     if (!current->reply_size)
 221     {
 222         if ((ret = write( get_unix_fd( current->reply_fd ),
 223                           reply, sizeof(*reply) )) != sizeof(*reply)) goto error;
 224     }
 225     else
 226     {
 227         struct iovec vec[2];
 228
 229         vec[0].iov_base = (void *)reply;
 230         vec[0].iov_len  = sizeof(*reply);
 231         vec[1].iov_base = current->reply_data;
 232         vec[1].iov_len  = current->reply_size;
 233
 234         if ((ret = writev( get_unix_fd( current->reply_fd ), vec, 2 )) < sizeof(*reply)) goto error;
 235
 236         if ((current->reply_towrite = current->reply_size - (ret - sizeof(*reply))))
 237         {
 238             /* couldn't write it all, wait for POLLOUT */
 239             set_fd_events( current->reply_fd, POLLOUT );
 240             set_fd_events( current->request_fd, 0 );
 241             return;
 242         }
 243     }
 244     free( current->reply_data );
 245     current->reply_data = NULL;
 246     return;
 247
 248  error:
 249     if (ret >= 0)
 250         fatal_protocol_error( current, "partial write %d\n", ret );
 251     else if (errno == EPIPE)
 252         kill_thread( current, 0 );  /* normal death */
 253     else
 254         fatal_protocol_perror( current, "reply write" );
 255 }
 256
 257 /* call a request handler */
 258 static void call_req_handler( struct thread *thread )
 259 {
 260     union generic_reply reply;
 261     enum request req = thread->req.request_header.req;
 262
 263     current = thread;
 264     current->reply_size = 0;
 265     clear_error();
 266     memset( &reply, 0, sizeof(reply) );
 267
 268     if (debug_level) trace_request();
 269
 270     if (req < REQ_NB_REQUESTS)
 271         req_handlers[req]( &current->req, &reply );
 272     else
 273         set_error( STATUS_NOT_IMPLEMENTED );
 274
 275     if (current)
 276     {
 277         if (current->reply_fd)
 278         {
 279             reply.reply_header.error = current->error;
 280             reply.reply_header.reply_size = current->reply_size;
 281             if (debug_level) trace_reply( req, &reply );
 282             send_reply( &reply );
 283         }
 284         else
 285         {
 286             current->exit_code = 1;
 287             kill_thread( current, 1 );  /* no way to continue without reply fd */
 288         }
 289     }
 290     current = NULL;
 291 }
 292
 293 /* read a request from a thread */
 294 void read_request( struct thread *thread )
 295 {
 296     int ret;
 297
 298     if (!thread->req_toread)  /* no pending request */
 299     {
 300         if ((ret = read( get_unix_fd( thread->request_fd ), &thread->req,
 301                          sizeof(thread->req) )) != sizeof(thread->req)) goto error;
 302         if (!(thread->req_toread = thread->req.request_header.request_size))
 303         {
 304             /* no data, handle request at once */
 305             call_req_handler( thread );
 306             return;
 307         }
 308         if (!(thread->req_data = malloc( thread->req_toread )))
 309         {
 310             fatal_protocol_error( thread, "no memory for %u bytes request %d\n",
 311                                   thread->req_toread, thread->req.request_header.req );
 312             return;
 313         }
 314     }
 315
 316     /* read the variable sized data */
 317     for (;;)
 318     {
 319         ret = read( get_unix_fd( thread->request_fd ),
 320                     (char *)thread->req_data + thread->req.request_header.request_size
 321                       - thread->req_toread,
 322                     thread->req_toread );
 323         if (ret <= 0) break;
 324         if (!(thread->req_toread -= ret))
 325         {
 326             call_req_handler( thread );
 327             free( thread->req_data );
 328             thread->req_data = NULL;
 329             return;
 330         }
 331     }
 332
 333 error:
 334     if (!ret)  /* closed pipe */
 335         kill_thread( thread, 0 );
 336     else if (ret > 0)
 337         fatal_protocol_error( thread, "partial read %d\n", ret );
 338     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 339         fatal_protocol_perror( thread, "read" );
 340 }
 341
 342 /* receive a file descriptor on the process socket */
 343 int receive_fd( struct process *process )
 344 {
 345     struct iovec vec;
 346     struct send_fd data;
 347     struct msghdr msghdr;
 348     int fd = -1, ret;
 349
 350 #ifdef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 351     msghdr.msg_accrightslen = sizeof(int);
 352     msghdr.msg_accrights = (void *)&fd;
 353 #else  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 354     char cmsg_buffer[256];
 355     msghdr.msg_control    = cmsg_buffer;
 356     msghdr.msg_controllen = sizeof(cmsg_buffer);
 357     msghdr.msg_flags      = 0;
 358 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 359
 360     msghdr.msg_name    = NULL;
 361     msghdr.msg_namelen = 0;
 362     msghdr.msg_iov     = &vec;
 363     msghdr.msg_iovlen  = 1;
 364     vec.iov_base = (void *)&data;
 365     vec.iov_len  = sizeof(data);
 366
 367     ret = recvmsg( get_unix_fd( process->msg_fd ), &msghdr, 0 );
 368
 369 #ifndef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 370     if (ret > 0)
 371     {
 372         struct cmsghdr *cmsg;
 373         for (cmsg = CMSG_FIRSTHDR( &msghdr ); cmsg; cmsg = CMSG_NXTHDR( &msghdr, cmsg ))
 374         {
 375             if (cmsg->cmsg_level != SOL_SOCKET) continue;
 376             if (cmsg->cmsg_type == SCM_RIGHTS) fd = *(int *)CMSG_DATA(cmsg);
 377         }
 378     }
 379 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 380
 381     if (ret == sizeof(data))
 382     {
 383         struct thread *thread;
 384
 385         if (data.tid) thread = get_thread_from_id( data.tid );
 386         else thread = (struct thread *)grab_object( get_process_first_thread( process ));
 387
 388         if (!thread || thread->process != process || thread->state == TERMINATED)
 389         {
 390             if (debug_level)
 391                 fprintf( stderr, "%04x: *fd* %d <- %d bad thread id\n",
 392                          data.tid, data.fd, fd );
 393             close( fd );
 394         }
 395         else
 396         {
 397             if (debug_level)
 398                 fprintf( stderr, "%04x: *fd* %d <- %d\n",
 399                          thread->id, data.fd, fd );
 400             thread_add_inflight_fd( thread, data.fd, fd );
 401         }
 402         if (thread) release_object( thread );
 403         return 0;
 404     }
 405
 406     if (!ret)
 407     {
 408         kill_process( process, 0 );
 409     }
 410     else if (ret > 0)
 411     {
 412         fprintf( stderr, "Protocol error: process %04x: partial recvmsg %d for fd\n",
 413                  process->id, ret );
 414         if (fd != -1) close( fd );
 415         kill_process( process, 1 );
 416     }
 417     else
 418     {
 419         if (errno != EWOULDBLOCK && errno != EAGAIN)
 420         {
 421             fprintf( stderr, "Protocol error: process %04x: ", process->id );
 422             perror( "recvmsg" );
 423             kill_process( process, 1 );
 424         }
 425     }
 426     return -1;
 427 }
 428
 429 /* send an fd to a client */
 430 int send_client_fd( struct process *process, int fd, obj_handle_t handle )
 431 {
 432     struct iovec vec;
 433     struct msghdr msghdr;
 434     int ret;
 435
 436 #ifdef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 437     msghdr.msg_accrightslen = sizeof(fd);
 438     msghdr.msg_accrights = (void *)&fd;
 439 #else  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 440     char cmsg_buffer[256];
 441     struct cmsghdr *cmsg;
 442     msghdr.msg_control    = cmsg_buffer;
 443     msghdr.msg_controllen = sizeof(cmsg_buffer);
 444     msghdr.msg_flags      = 0;
 445     cmsg = CMSG_FIRSTHDR( &msghdr );
 446     cmsg->cmsg_len   = CMSG_LEN( sizeof(fd) );
 447     cmsg->cmsg_level = SOL_SOCKET;
 448     cmsg->cmsg_type  = SCM_RIGHTS;
 449     *(int *)CMSG_DATA(cmsg) = fd;
 450     msghdr.msg_controllen = cmsg->cmsg_len;
 451 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 452
 453     msghdr.msg_name    = NULL;
 454     msghdr.msg_namelen = 0;
 455     msghdr.msg_iov     = &vec;
 456     msghdr.msg_iovlen  = 1;
 457
 458     vec.iov_base = (void *)&handle;
 459     vec.iov_len  = sizeof(handle);
 460
 461     if (debug_level)
 462         fprintf( stderr, "%04x: *fd* %04x -> %d\n", current ? current->id : process->id, handle, fd );
 463
 464     ret = sendmsg( get_unix_fd( process->msg_fd ), &msghdr, 0 );
 465
 466     if (ret == sizeof(handle)) return 0;
 467
 468     if (ret >= 0)
 469     {
 470         fprintf( stderr, "Protocol error: process %04x: partial sendmsg %d\n", process->id, ret );
 471         kill_process( process, 1 );
 472     }
 473     else if (errno == EPIPE)
 474     {
 475         kill_process( process, 0 );
 476     }
 477     else
 478     {
 479         fprintf( stderr, "Protocol error: process %04x: ", process->id );
 480         perror( "sendmsg" );
 481         kill_process( process, 1 );
 482     }
 483     return -1;
 484 }
 485
 486 /* get current tick count to return to client */
 487 unsigned int get_tick_count(void)
 488 {
 489     return (current_time - server_start_time) / 10000;
 490 }
 491
 492 static void master_socket_dump( struct object *obj, int verbose )
 493 {
 494     struct master_socket *sock = (struct master_socket *)obj;
 495     assert( obj->ops == &master_socket_ops );
 496     fprintf( stderr, "Master socket fd=%p\n", sock->fd );
 497 }
 498
 499 static void master_socket_destroy( struct object *obj )
 500 {
 501     struct master_socket *sock = (struct master_socket *)obj;
 502     assert( obj->ops == &master_socket_ops );
 503     release_object( sock->fd );
 504 }
 505
 506 /* handle a socket event */
 507 static void master_socket_poll_event( struct fd *fd, int event )
 508 {
 509     struct master_socket *sock = get_fd_user( fd );
 510     assert( master_socket->obj.ops == &master_socket_ops );
 511
 512     assert( sock == master_socket );  /* there is only one master socket */
 513
 514     if (event & (POLLERR | POLLHUP))
 515     {
 516         /* this is not supposed to happen */
 517         fprintf( stderr, "wineserver: Error on master socket\n" );
 518         set_fd_events( sock->fd, -1 );
 519     }
 520     else if (event & POLLIN)
 521     {
 522         struct sockaddr_un dummy;
 523         unsigned int len = sizeof(dummy);
 524         int client = accept( get_unix_fd( master_socket->fd ), (struct sockaddr *) &dummy, &len );
 525         if (client == -1) return;
 526         fcntl( client, F_SETFL, O_NONBLOCK );
 527         create_process( client, NULL, 0 );
 528     }
 529 }
 530
 531 /* remove the socket upon exit */
 532 static void socket_cleanup(void)
 533 {
 534     static int do_it_once;
 535     if (!do_it_once++) unlink( server_socket_name );
 536 }
 537
 538 /* create a directory and check its permissions */
 539 static void create_dir( const char *name, struct stat *st )
 540 {
 541     if (lstat( name, st ) == -1)
 542     {
 543         if (errno != ENOENT) fatal_perror( "lstat %s", name );
 544         if (mkdir( name, 0700 ) == -1 && errno != EEXIST) fatal_perror( "mkdir %s", name );
 545         if (lstat( name, st ) == -1) fatal_perror( "lstat %s", name );
 546     }
 547     if (!S_ISDIR(st->st_mode)) fatal_error( "%s is not a directory\n", name );
 548     if (st->st_uid != getuid()) fatal_error( "%s is not owned by you\n", name );
 549     if (st->st_mode & 077) fatal_error( "%s must not be accessible by other users\n", name );
 550 }
 551
 552 /* create the server directory and chdir to it */
 553 static void create_server_dir( const char *dir )
 554 {
 555     char *p, *server_dir;
 556     struct stat st, st2;
 557
 558     if (!(server_dir = strdup( dir ))) fatal_error( "out of memory\n" );
 559
 560     /* first create the base directory if needed */
 561
 562     p = strrchr( server_dir, '/' );
 563     *p = 0;
 564     create_dir( server_dir, &st );
 565
 566     /* now create the server directory */
 567
 568     *p = '/';
 569     create_dir( server_dir, &st );
 570
 571     if (chdir( server_dir ) == -1) fatal_perror( "chdir %s", server_dir );
 572     if ((server_dir_fd = open( ".", O_RDONLY )) == -1) fatal_perror( "open %s", server_dir );
 573     if (fstat( server_dir_fd, &st2 ) == -1) fatal_perror( "stat %s", server_dir );
 574     if (st.st_dev != st2.st_dev || st.st_ino != st2.st_ino)
 575         fatal_error( "chdir did not end up in %s\n", server_dir );
 576
 577     free( server_dir );
 578 }
 579
 580 /* create the lock file and return its file descriptor */
 581 static int create_server_lock(void)
 582 {
 583     struct stat st;
 584     int fd;
 585
 586     if (lstat( server_lock_name, &st ) == -1)
 587     {
 588         if (errno != ENOENT)
 589             fatal_perror( "lstat %s/%s", wine_get_server_dir(), server_lock_name );
 590     }
 591     else
 592     {
 593         if (!S_ISREG(st.st_mode))
 594             fatal_error( "%s/%s is not a regular file\n", wine_get_server_dir(), server_lock_name );
 595     }
 596
 597     if ((fd = open( server_lock_name, O_CREAT|O_TRUNC|O_WRONLY, 0600 )) == -1)
 598         fatal_perror( "error creating %s/%s", wine_get_server_dir(), server_lock_name );
 599     return fd;
 600 }
 601
 602 /* wait for the server lock */
 603 int wait_for_lock(void)
 604 {
 605     const char *server_dir = wine_get_server_dir();
 606     int fd, r;
 607     struct flock fl;
 608
 609     if (!server_dir) return 0;  /* no server dir, so no lock to wait on */
 610
 611     create_server_dir( server_dir );
 612     fd = create_server_lock();
 613
 614     fl.l_type   = F_WRLCK;
 615     fl.l_whence = SEEK_SET;
 616     fl.l_start  = 0;
 617     fl.l_len    = 1;
 618     r = fcntl( fd, F_SETLKW, &fl );
 619     close(fd);
 620
 621     return r;
 622 }
 623
 624 /* kill the wine server holding the lock */
 625 int kill_lock_owner( int sig )
 626 {
 627     const char *server_dir = wine_get_server_dir();
 628     int fd, i, ret = 0;
 629     pid_t pid = 0;
 630     struct flock fl;
 631
 632     if (!server_dir) return 0;  /* no server dir, nothing to do */
 633
 634     create_server_dir( server_dir );
 635     fd = create_server_lock();
 636
 637     for (i = 1; i <= 20; i++)
 638     {
 639         fl.l_type   = F_WRLCK;
 640         fl.l_whence = SEEK_SET;
 641         fl.l_start  = 0;
 642         fl.l_len    = 1;
 643         if (fcntl( fd, F_GETLK, &fl ) == -1) goto done;
 644         if (fl.l_type != F_WRLCK) goto done;  /* the file is not locked */
 645         if (!pid)  /* first time around */
 646         {
 647             if (!(pid = fl.l_pid)) goto done;  /* shouldn't happen */
 648             if (sig == -1)
 649             {
 650                 if (kill( pid, SIGINT ) == -1) goto done;
 651                 kill( pid, SIGCONT );
 652                 ret = 1;
 653             }
 654             else  /* just send the specified signal and return */
 655             {
 656                 ret = (kill( pid, sig ) != -1);
 657                 goto done;
 658             }
 659         }
 660         else if (fl.l_pid != pid) goto done;  /* no longer the same process */
 661         usleep( 50000 * i );
 662     }
 663     /* waited long enough, now kill it */
 664     kill( pid, SIGKILL );
 665
 666  done:
 667     close( fd );
 668     return ret;
 669 }
 670
 671 /* acquire the main server lock */
 672 static void acquire_lock(void)
 673 {
 674     struct sockaddr_un addr;
 675     struct stat st;
 676     struct flock fl;
 677     int fd, slen, got_lock = 0;
 678
 679     fd = create_server_lock();
 680
 681     fl.l_type   = F_WRLCK;
 682     fl.l_whence = SEEK_SET;
 683     fl.l_start  = 0;
 684     fl.l_len    = 1;
 685     if (fcntl( fd, F_SETLK, &fl ) != -1)
 686     {
 687         /* check for crashed server */
 688         if (stat( server_socket_name, &st ) != -1 &&   /* there is a leftover socket */
 689             stat( "core", &st ) != -1 && st.st_size)   /* and there is a non-empty core file */
 690         {
 691             fprintf( stderr,
 692                      "Warning: a previous instance of the wine server seems to have crashed.\n"
 693                      "Please run 'gdb %s %s/core',\n"
 694                      "type 'backtrace' at the gdb prompt and report the results. Thanks.\n\n",
 695                      server_argv0, wine_get_server_dir() );
 696         }
 697         unlink( server_socket_name ); /* we got the lock, we can safely remove the socket */
 698         got_lock = 1;
 699         /* in that case we reuse fd without closing it, this ensures
 700          * that we hold the lock until the process exits */
 701     }
 702     else
 703     {
 704         switch(errno)
 705         {
 706         case ENOLCK:
 707             break;
 708         case EACCES:
 709             /* check whether locks work at all on this file system */
 710             if (fcntl( fd, F_GETLK, &fl ) == -1) break;
 711             /* fall through */
 712         case EAGAIN:
 713             exit(2); /* we didn't get the lock, exit with special status */
 714         default:
 715             fatal_perror( "fcntl %s/%s", wine_get_server_dir(), server_lock_name );
 716         }
 717         /* it seems we can't use locks on this fs, so we will use the socket existence as lock */
 718         close( fd );
 719     }
 720
 721     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 722     addr.sun_family = AF_UNIX;
 723     strcpy( addr.sun_path, server_socket_name );
 724     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 725 #ifdef HAVE_STRUCT_SOCKADDR_UN_SUN_LEN
 726     addr.sun_len = slen;
 727 #endif
 728     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 729     {
 730         if ((errno == EEXIST) || (errno == EADDRINUSE))
 731         {
 732             if (got_lock)
 733                 fatal_error( "couldn't bind to the socket even though we hold the lock\n" );
 734             exit(2); /* we didn't get the lock, exit with special status */
 735         }
 736         fatal_perror( "bind" );
 737     }
 738     atexit( socket_cleanup );
 739     chmod( server_socket_name, 0600 );  /* make sure no other user can connect */
 740     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 741
 742     if (!(master_socket = alloc_object( &master_socket_ops )) ||
 743         !(master_socket->fd = create_anonymous_fd( &master_socket_fd_ops, fd, &master_socket->obj, 0 )))
 744         fatal_error( "out of memory\n" );
 745     set_fd_events( master_socket->fd, POLLIN );
 746     make_object_static( &master_socket->obj );
 747 }
 748
 749 /* open the master server socket and start waiting for new clients */
 750 void open_master_socket(void)
 751 {
 752     const char *server_dir = wine_get_server_dir();
 753     const char *config_dir = wine_get_config_dir();
 754     int fd, pid, status, sync_pipe[2];
 755     char dummy;
 756
 757     /* make sure no request is larger than the maximum size */
 758     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 759     assert( sizeof(union generic_reply) == sizeof(struct request_max_size) );
 760
 761     /* make sure the stdio fds are open */
 762     fd = open( "/dev/null", O_RDWR );
 763     while (fd >= 0 && fd <= 2) fd = dup( fd );
 764
 765     if (!server_dir) fatal_error( "directory %s cannot be accessed\n", config_dir );
 766     if (chdir( config_dir ) == -1) fatal_perror( "chdir to %s", config_dir );
 767     if ((config_dir_fd = open( ".", O_RDONLY )) == -1) fatal_perror( "open %s", config_dir );
 768
 769     create_server_dir( server_dir );
 770
 771     if (!foreground)
 772     {
 773         if (pipe( sync_pipe ) == -1) fatal_perror( "pipe" );
 774         pid = fork();
 775         switch( pid )
 776         {
 777         case 0:  /* child */
 778             setsid();
 779             close( sync_pipe[0] );
 780
 781             acquire_lock();
 782
 783             /* close stdin and stdout */
 784             dup2( fd, 0 );
 785             dup2( fd, 1 );
 786
 787             /* signal parent */
 788             dummy = 0;
 789             write( sync_pipe[1], &dummy, 1 );
 790             close( sync_pipe[1] );
 791             break;
 792
 793         case -1:
 794             fatal_perror( "fork" );
 795             break;
 796
 797         default:  /* parent */
 798             close( sync_pipe[1] );
 799
 800             /* wait for child to signal us and then exit */
 801             if (read( sync_pipe[0], &dummy, 1 ) == 1) _exit(0);
 802
 803             /* child terminated, propagate exit status */
 804             wait4( pid, &status, 0, NULL );
 805             if (WIFEXITED(status)) _exit( WEXITSTATUS(status) );
 806             _exit(1);
 807         }
 808     }
 809     else  /* remain in the foreground */
 810     {
 811         acquire_lock();
 812     }
 813
 814     /* init the process tracing mechanism */
 815     init_tracing_mechanism();
 816     close( fd );
 817 }
 818
 819 /* master socket timer expiration handler */
 820 static void close_socket_timeout( void *arg )
 821 {
 822     master_timeout = NULL;
 823     flush_registry();
 824     if (debug_level) fprintf( stderr, "wineserver: exiting (pid=%ld)\n", (long) getpid() );
 825
 826 #ifdef DEBUG_OBJECTS
 827     close_objects();  /* shut down everything properly */
 828 #endif
 829     exit( 0 );
 830 }
 831
 832 /* close the master socket and stop waiting for new clients */
 833 void close_master_socket( timeout_t timeout )
 834 {
 835     if (master_socket)
 836     {
 837         release_object( master_socket );
 838         master_socket = NULL;
 839     }
 840     if (master_timeout)  /* cancel previous timeout */
 841         remove_timeout_user( master_timeout );
 842
 843     master_timeout = add_timeout_user( timeout, close_socket_timeout, NULL );
 844 }