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 /* die on a fatal error */
 146 void fatal_error( const char *err, ... )
 147 {
 148     va_list args;
 149
 150     va_start( args, err );
 151     fprintf( stderr, "wineserver: " );
 152     vfprintf( stderr, err, args );
 153     va_end( args );
 154     exit(1);
 155 }
 156
 157 /* allocate the reply data */
 158 void *set_reply_data_size( data_size_t size )
 159 {
 160     assert( size <= get_reply_max_size() );
 161     if (size && !(current->reply_data = mem_alloc( size ))) size = 0;
 162     current->reply_size = size;
 163     return current->reply_data;
 164 }
 165
 166 /* write the remaining part of the reply */
 167 void write_reply( struct thread *thread )
 168 {
 169     int ret;
 170
 171     if ((ret = write( get_unix_fd( thread->reply_fd ),
 172                       (char *)thread->reply_data + thread->reply_size - thread->reply_towrite,
 173                       thread->reply_towrite )) >= 0)
 174     {
 175         if (!(thread->reply_towrite -= ret))
 176         {
 177             free( thread->reply_data );
 178             thread->reply_data = NULL;
 179             /* sent everything, can go back to waiting for requests */
 180             set_fd_events( thread->request_fd, POLLIN );
 181             set_fd_events( thread->reply_fd, 0 );
 182         }
 183         return;
 184     }
 185     if (errno == EPIPE)
 186         kill_thread( thread, 0 );  /* normal death */
 187     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 188         fatal_protocol_error( thread, "reply write: %s\n", strerror( errno ));
 189 }
 190
 191 /* send a reply to the current thread */
 192 static void send_reply( union generic_reply *reply )
 193 {
 194     int ret;
 195
 196     if (!current->reply_size)
 197     {
 198         if ((ret = write( get_unix_fd( current->reply_fd ),
 199                           reply, sizeof(*reply) )) != sizeof(*reply)) goto error;
 200     }
 201     else
 202     {
 203         struct iovec vec[2];
 204
 205         vec[0].iov_base = (void *)reply;
 206         vec[0].iov_len  = sizeof(*reply);
 207         vec[1].iov_base = current->reply_data;
 208         vec[1].iov_len  = current->reply_size;
 209
 210         if ((ret = writev( get_unix_fd( current->reply_fd ), vec, 2 )) < sizeof(*reply)) goto error;
 211
 212         if ((current->reply_towrite = current->reply_size - (ret - sizeof(*reply))))
 213         {
 214             /* couldn't write it all, wait for POLLOUT */
 215             set_fd_events( current->reply_fd, POLLOUT );
 216             set_fd_events( current->request_fd, 0 );
 217             return;
 218         }
 219     }
 220     free( current->reply_data );
 221     current->reply_data = NULL;
 222     return;
 223
 224  error:
 225     if (ret >= 0)
 226         fatal_protocol_error( current, "partial write %d\n", ret );
 227     else if (errno == EPIPE)
 228         kill_thread( current, 0 );  /* normal death */
 229     else
 230         fatal_protocol_error( current, "reply write: %s\n", strerror( errno ));
 231 }
 232
 233 /* call a request handler */
 234 static void call_req_handler( struct thread *thread )
 235 {
 236     union generic_reply reply;
 237     enum request req = thread->req.request_header.req;
 238
 239     current = thread;
 240     current->reply_size = 0;
 241     clear_error();
 242     memset( &reply, 0, sizeof(reply) );
 243
 244     if (debug_level) trace_request();
 245
 246     if (req < REQ_NB_REQUESTS)
 247         req_handlers[req]( &current->req, &reply );
 248     else
 249         set_error( STATUS_NOT_IMPLEMENTED );
 250
 251     if (current)
 252     {
 253         if (current->reply_fd)
 254         {
 255             reply.reply_header.error = current->error;
 256             reply.reply_header.reply_size = current->reply_size;
 257             if (debug_level) trace_reply( req, &reply );
 258             send_reply( &reply );
 259         }
 260         else
 261         {
 262             current->exit_code = 1;
 263             kill_thread( current, 1 );  /* no way to continue without reply fd */
 264         }
 265     }
 266     current = NULL;
 267 }
 268
 269 /* read a request from a thread */
 270 void read_request( struct thread *thread )
 271 {
 272     int ret;
 273
 274     if (!thread->req_toread)  /* no pending request */
 275     {
 276         if ((ret = read( get_unix_fd( thread->request_fd ), &thread->req,
 277                          sizeof(thread->req) )) != sizeof(thread->req)) goto error;
 278         if (!(thread->req_toread = thread->req.request_header.request_size))
 279         {
 280             /* no data, handle request at once */
 281             call_req_handler( thread );
 282             return;
 283         }
 284         if (!(thread->req_data = malloc( thread->req_toread )))
 285         {
 286             fatal_protocol_error( thread, "no memory for %u bytes request %d\n",
 287                                   thread->req_toread, thread->req.request_header.req );
 288             return;
 289         }
 290     }
 291
 292     /* read the variable sized data */
 293     for (;;)
 294     {
 295         ret = read( get_unix_fd( thread->request_fd ),
 296                     (char *)thread->req_data + thread->req.request_header.request_size
 297                       - thread->req_toread,
 298                     thread->req_toread );
 299         if (ret <= 0) break;
 300         if (!(thread->req_toread -= ret))
 301         {
 302             call_req_handler( thread );
 303             free( thread->req_data );
 304             thread->req_data = NULL;
 305             return;
 306         }
 307     }
 308
 309 error:
 310     if (!ret)  /* closed pipe */
 311         kill_thread( thread, 0 );
 312     else if (ret > 0)
 313         fatal_protocol_error( thread, "partial read %d\n", ret );
 314     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 315         fatal_protocol_error( thread, "read: %s\n", strerror( errno ));
 316 }
 317
 318 /* receive a file descriptor on the process socket */
 319 int receive_fd( struct process *process )
 320 {
 321     struct iovec vec;
 322     struct send_fd data;
 323     struct msghdr msghdr;
 324     int fd = -1, ret;
 325
 326 #ifdef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 327     msghdr.msg_accrightslen = sizeof(int);
 328     msghdr.msg_accrights = (void *)&fd;
 329 #else  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 330     char cmsg_buffer[256];
 331     msghdr.msg_control    = cmsg_buffer;
 332     msghdr.msg_controllen = sizeof(cmsg_buffer);
 333     msghdr.msg_flags      = 0;
 334 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 335
 336     msghdr.msg_name    = NULL;
 337     msghdr.msg_namelen = 0;
 338     msghdr.msg_iov     = &vec;
 339     msghdr.msg_iovlen  = 1;
 340     vec.iov_base = (void *)&data;
 341     vec.iov_len  = sizeof(data);
 342
 343     ret = recvmsg( get_unix_fd( process->msg_fd ), &msghdr, 0 );
 344
 345 #ifndef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 346     if (ret > 0)
 347     {
 348         struct cmsghdr *cmsg;
 349         for (cmsg = CMSG_FIRSTHDR( &msghdr ); cmsg; cmsg = CMSG_NXTHDR( &msghdr, cmsg ))
 350         {
 351             if (cmsg->cmsg_level != SOL_SOCKET) continue;
 352             if (cmsg->cmsg_type == SCM_RIGHTS) fd = *(int *)CMSG_DATA(cmsg);
 353         }
 354     }
 355 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 356
 357     if (ret == sizeof(data))
 358     {
 359         struct thread *thread;
 360
 361         if (data.tid) thread = get_thread_from_id( data.tid );
 362         else thread = (struct thread *)grab_object( get_process_first_thread( process ));
 363
 364         if (!thread || thread->process != process || thread->state == TERMINATED)
 365         {
 366             if (debug_level)
 367                 fprintf( stderr, "%04x: *fd* %d <- %d bad thread id\n",
 368                          data.tid, data.fd, fd );
 369             close( fd );
 370         }
 371         else
 372         {
 373             if (debug_level)
 374                 fprintf( stderr, "%04x: *fd* %d <- %d\n",
 375                          thread->id, data.fd, fd );
 376             thread_add_inflight_fd( thread, data.fd, fd );
 377         }
 378         if (thread) release_object( thread );
 379         return 0;
 380     }
 381
 382     if (!ret)
 383     {
 384         kill_process( process, 0 );
 385     }
 386     else if (ret > 0)
 387     {
 388         fprintf( stderr, "Protocol error: process %04x: partial recvmsg %d for fd\n",
 389                  process->id, ret );
 390         if (fd != -1) close( fd );
 391         kill_process( process, 1 );
 392     }
 393     else
 394     {
 395         if (errno != EWOULDBLOCK && errno != EAGAIN)
 396         {
 397             fprintf( stderr, "Protocol error: process %04x: ", process->id );
 398             perror( "recvmsg" );
 399             kill_process( process, 1 );
 400         }
 401     }
 402     return -1;
 403 }
 404
 405 /* send an fd to a client */
 406 int send_client_fd( struct process *process, int fd, obj_handle_t handle )
 407 {
 408     struct iovec vec;
 409     struct msghdr msghdr;
 410     int ret;
 411
 412 #ifdef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 413     msghdr.msg_accrightslen = sizeof(fd);
 414     msghdr.msg_accrights = (void *)&fd;
 415 #else  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 416     char cmsg_buffer[256];
 417     struct cmsghdr *cmsg;
 418     msghdr.msg_control    = cmsg_buffer;
 419     msghdr.msg_controllen = sizeof(cmsg_buffer);
 420     msghdr.msg_flags      = 0;
 421     cmsg = CMSG_FIRSTHDR( &msghdr );
 422     cmsg->cmsg_len   = CMSG_LEN( sizeof(fd) );
 423     cmsg->cmsg_level = SOL_SOCKET;
 424     cmsg->cmsg_type  = SCM_RIGHTS;
 425     *(int *)CMSG_DATA(cmsg) = fd;
 426     msghdr.msg_controllen = cmsg->cmsg_len;
 427 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 428
 429     msghdr.msg_name    = NULL;
 430     msghdr.msg_namelen = 0;
 431     msghdr.msg_iov     = &vec;
 432     msghdr.msg_iovlen  = 1;
 433
 434     vec.iov_base = (void *)&handle;
 435     vec.iov_len  = sizeof(handle);
 436
 437     if (debug_level)
 438         fprintf( stderr, "%04x: *fd* %04x -> %d\n", current ? current->id : process->id, handle, fd );
 439
 440     ret = sendmsg( get_unix_fd( process->msg_fd ), &msghdr, 0 );
 441
 442     if (ret == sizeof(handle)) return 0;
 443
 444     if (ret >= 0)
 445     {
 446         fprintf( stderr, "Protocol error: process %04x: partial sendmsg %d\n", process->id, ret );
 447         kill_process( process, 1 );
 448     }
 449     else if (errno == EPIPE)
 450     {
 451         kill_process( process, 0 );
 452     }
 453     else
 454     {
 455         fprintf( stderr, "Protocol error: process %04x: ", process->id );
 456         perror( "sendmsg" );
 457         kill_process( process, 1 );
 458     }
 459     return -1;
 460 }
 461
 462 /* get current tick count to return to client */
 463 unsigned int get_tick_count(void)
 464 {
 465 #ifdef HAVE_CLOCK_GETTIME
 466     struct timespec ts;
 467 #ifdef CLOCK_MONOTONIC_RAW
 468     if (!clock_gettime( CLOCK_MONOTONIC_RAW, &ts ))
 469         return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
 470 #endif
 471     if (!clock_gettime( CLOCK_MONOTONIC, &ts ))
 472         return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
 473 #elif defined(__APPLE__)
 474     static mach_timebase_info_data_t timebase;
 475
 476     if (!timebase.denom) mach_timebase_info( &timebase );
 477     return mach_absolute_time() * timebase.numer / timebase.denom / 1000000;
 478 #endif
 479     return (current_time - server_start_time) / 10000;
 480 }
 481
 482 static void master_socket_dump( struct object *obj, int verbose )
 483 {
 484     struct master_socket *sock = (struct master_socket *)obj;
 485     assert( obj->ops == &master_socket_ops );
 486     fprintf( stderr, "Master socket fd=%p\n", sock->fd );
 487 }
 488
 489 static void master_socket_destroy( struct object *obj )
 490 {
 491     struct master_socket *sock = (struct master_socket *)obj;
 492     assert( obj->ops == &master_socket_ops );
 493     release_object( sock->fd );
 494 }
 495
 496 /* handle a socket event */
 497 static void master_socket_poll_event( struct fd *fd, int event )
 498 {
 499     struct master_socket *sock = get_fd_user( fd );
 500     assert( master_socket->obj.ops == &master_socket_ops );
 501
 502     assert( sock == master_socket );  /* there is only one master socket */
 503
 504     if (event & (POLLERR | POLLHUP))
 505     {
 506         /* this is not supposed to happen */
 507         fprintf( stderr, "wineserver: Error on master socket\n" );
 508         set_fd_events( sock->fd, -1 );
 509     }
 510     else if (event & POLLIN)
 511     {
 512         struct sockaddr_un dummy;
 513         socklen_t len = sizeof(dummy);
 514         int client = accept( get_unix_fd( master_socket->fd ), (struct sockaddr *) &dummy, &len );
 515         if (client == -1) return;
 516         fcntl( client, F_SETFL, O_NONBLOCK );
 517         create_process( client, NULL, 0 );
 518     }
 519 }
 520
 521 /* remove the socket upon exit */
 522 static void socket_cleanup(void)
 523 {
 524     static int do_it_once;
 525     if (!do_it_once++) unlink( server_socket_name );
 526 }
 527
 528 /* create a directory and check its permissions */
 529 static void create_dir( const char *name, struct stat *st )
 530 {
 531     if (lstat( name, st ) == -1)
 532     {
 533         if (errno != ENOENT)
 534             fatal_error( "lstat %s: %s", name, strerror( errno ));
 535         if (mkdir( name, 0700 ) == -1 && errno != EEXIST)
 536             fatal_error( "mkdir %s: %s\n", name, strerror( errno ));
 537         if (lstat( name, st ) == -1)
 538             fatal_error( "lstat %s: %s\n", name, strerror( errno ));
 539     }
 540     if (!S_ISDIR(st->st_mode)) fatal_error( "%s is not a directory\n", name );
 541     if (st->st_uid != getuid()) fatal_error( "%s is not owned by you\n", name );
 542     if (st->st_mode & 077) fatal_error( "%s must not be accessible by other users\n", name );
 543 }
 544
 545 /* create the server directory and chdir to it */
 546 static void create_server_dir( const char *dir )
 547 {
 548     char *p, *server_dir;
 549     struct stat st, st2;
 550
 551     if (!(server_dir = strdup( dir ))) fatal_error( "out of memory\n" );
 552
 553     /* first create the base directory if needed */
 554
 555     p = strrchr( server_dir, '/' );
 556     *p = 0;
 557     create_dir( server_dir, &st );
 558
 559     /* now create the server directory */
 560
 561     *p = '/';
 562     create_dir( server_dir, &st );
 563
 564     if (chdir( server_dir ) == -1)
 565         fatal_error( "chdir %s: %s\n", server_dir, strerror( errno ));
 566     if ((server_dir_fd = open( ".", O_RDONLY )) == -1)
 567         fatal_error( "open %s: %s\n", server_dir, strerror( errno ));
 568     if (fstat( server_dir_fd, &st2 ) == -1)
 569         fatal_error( "stat %s: %s\n", server_dir, strerror( errno ));
 570     if (st.st_dev != st2.st_dev || st.st_ino != st2.st_ino)
 571         fatal_error( "chdir did not end up in %s\n", server_dir );
 572
 573     free( server_dir );
 574 }
 575
 576 /* create the lock file and return its file descriptor */
 577 static int create_server_lock(void)
 578 {
 579     struct stat st;
 580     int fd;
 581
 582     if (lstat( server_lock_name, &st ) == -1)
 583     {
 584         if (errno != ENOENT)
 585             fatal_error( "lstat %s/%s: %s", wine_get_server_dir(), server_lock_name, strerror( errno ));
 586     }
 587     else
 588     {
 589         if (!S_ISREG(st.st_mode))
 590             fatal_error( "%s/%s is not a regular file\n", wine_get_server_dir(), server_lock_name );
 591     }
 592
 593     if ((fd = open( server_lock_name, O_CREAT|O_TRUNC|O_WRONLY, 0600 )) == -1)
 594         fatal_error( "error creating %s/%s: %s", wine_get_server_dir(), server_lock_name, strerror( errno ));
 595     return fd;
 596 }
 597
 598 /* wait for the server lock */
 599 int wait_for_lock(void)
 600 {
 601     const char *server_dir = wine_get_server_dir();
 602     int fd, r;
 603     struct flock fl;
 604
 605     if (!server_dir) return 0;  /* no server dir, so no lock to wait on */
 606
 607     create_server_dir( server_dir );
 608     fd = create_server_lock();
 609
 610     fl.l_type   = F_WRLCK;
 611     fl.l_whence = SEEK_SET;
 612     fl.l_start  = 0;
 613     fl.l_len    = 1;
 614     r = fcntl( fd, F_SETLKW, &fl );
 615     close(fd);
 616
 617     return r;
 618 }
 619
 620 /* kill the wine server holding the lock */
 621 int kill_lock_owner( int sig )
 622 {
 623     const char *server_dir = wine_get_server_dir();
 624     int fd, i, ret = 0;
 625     pid_t pid = 0;
 626     struct flock fl;
 627
 628     if (!server_dir) return 0;  /* no server dir, nothing to do */
 629
 630     create_server_dir( server_dir );
 631     fd = create_server_lock();
 632
 633     for (i = 1; i <= 20; i++)
 634     {
 635         fl.l_type   = F_WRLCK;
 636         fl.l_whence = SEEK_SET;
 637         fl.l_start  = 0;
 638         fl.l_len    = 1;
 639         if (fcntl( fd, F_GETLK, &fl ) == -1) goto done;
 640         if (fl.l_type != F_WRLCK) goto done;  /* the file is not locked */
 641         if (!pid)  /* first time around */
 642         {
 643             if (!(pid = fl.l_pid)) goto done;  /* shouldn't happen */
 644             if (sig == -1)
 645             {
 646                 if (kill( pid, SIGINT ) == -1) goto done;
 647                 kill( pid, SIGCONT );
 648                 ret = 1;
 649             }
 650             else  /* just send the specified signal and return */
 651             {
 652                 ret = (kill( pid, sig ) != -1);
 653                 goto done;
 654             }
 655         }
 656         else if (fl.l_pid != pid) goto done;  /* no longer the same process */
 657         usleep( 50000 * i );
 658     }
 659     /* waited long enough, now kill it */
 660     kill( pid, SIGKILL );
 661
 662  done:
 663     close( fd );
 664     return ret;
 665 }
 666
 667 /* acquire the main server lock */
 668 static void acquire_lock(void)
 669 {
 670     struct sockaddr_un addr;
 671     struct stat st;
 672     struct flock fl;
 673     int fd, slen, got_lock = 0;
 674
 675     fd = create_server_lock();
 676
 677     fl.l_type   = F_WRLCK;
 678     fl.l_whence = SEEK_SET;
 679     fl.l_start  = 0;
 680     fl.l_len    = 1;
 681     if (fcntl( fd, F_SETLK, &fl ) != -1)
 682     {
 683         /* check for crashed server */
 684         if (stat( server_socket_name, &st ) != -1 &&   /* there is a leftover socket */
 685             stat( "core", &st ) != -1 && st.st_size)   /* and there is a non-empty core file */
 686         {
 687             fprintf( stderr,
 688                      "Warning: a previous instance of the wine server seems to have crashed.\n"
 689                      "Please run 'gdb %s %s/core',\n"
 690                      "type 'backtrace' at the gdb prompt and report the results. Thanks.\n\n",
 691                      server_argv0, wine_get_server_dir() );
 692         }
 693         unlink( server_socket_name ); /* we got the lock, we can safely remove the socket */
 694         got_lock = 1;
 695         /* in that case we reuse fd without closing it, this ensures
 696          * that we hold the lock until the process exits */
 697     }
 698     else
 699     {
 700         switch(errno)
 701         {
 702         case ENOLCK:
 703             break;
 704         case EACCES:
 705             /* check whether locks work at all on this file system */
 706             if (fcntl( fd, F_GETLK, &fl ) == -1) break;
 707             /* fall through */
 708         case EAGAIN:
 709             exit(2); /* we didn't get the lock, exit with special status */
 710         default:
 711             fatal_error( "fcntl %s/%s: %s", wine_get_server_dir(), server_lock_name, strerror( errno ));
 712         }
 713         /* it seems we can't use locks on this fs, so we will use the socket existence as lock */
 714         close( fd );
 715     }
 716
 717     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_error( "socket: %s\n", strerror( errno ));
 718     addr.sun_family = AF_UNIX;
 719     strcpy( addr.sun_path, server_socket_name );
 720     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 721 #ifdef HAVE_STRUCT_SOCKADDR_UN_SUN_LEN
 722     addr.sun_len = slen;
 723 #endif
 724     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 725     {
 726         if ((errno == EEXIST) || (errno == EADDRINUSE))
 727         {
 728             if (got_lock)
 729                 fatal_error( "couldn't bind to the socket even though we hold the lock\n" );
 730             exit(2); /* we didn't get the lock, exit with special status */
 731         }
 732         fatal_error( "bind: %s\n", strerror( errno ));
 733     }
 734     atexit( socket_cleanup );
 735     chmod( server_socket_name, 0600 );  /* make sure no other user can connect */
 736     if (listen( fd, 5 ) == -1) fatal_error( "listen: %s\n", strerror( errno ));
 737
 738     if (!(master_socket = alloc_object( &master_socket_ops )) ||
 739         !(master_socket->fd = create_anonymous_fd( &master_socket_fd_ops, fd, &master_socket->obj, 0 )))
 740         fatal_error( "out of memory\n" );
 741     set_fd_events( master_socket->fd, POLLIN );
 742     make_object_static( &master_socket->obj );
 743 }
 744
 745 /* open the master server socket and start waiting for new clients */
 746 void open_master_socket(void)
 747 {
 748     const char *server_dir = wine_get_server_dir();
 749     const char *config_dir = wine_get_config_dir();
 750     int fd, pid, status, sync_pipe[2];
 751     char dummy;
 752
 753     /* make sure no request is larger than the maximum size */
 754     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 755     assert( sizeof(union generic_reply) == sizeof(struct request_max_size) );
 756
 757     /* make sure the stdio fds are open */
 758     fd = open( "/dev/null", O_RDWR );
 759     while (fd >= 0 && fd <= 2) fd = dup( fd );
 760
 761     if (!server_dir)
 762         fatal_error( "directory %s cannot be accessed\n", config_dir );
 763     if (chdir( config_dir ) == -1)
 764         fatal_error( "chdir to %s: %s\n", config_dir, strerror( errno ));
 765     if ((config_dir_fd = open( ".", O_RDONLY )) == -1)
 766         fatal_error( "open %s: %s\n", config_dir, strerror( errno ));
 767
 768     create_server_dir( server_dir );
 769
 770     if (!foreground)
 771     {
 772         if (pipe( sync_pipe ) == -1) fatal_error( "pipe: %s\n", strerror( errno ));
 773         pid = fork();
 774         switch( pid )
 775         {
 776         case 0:  /* child */
 777             setsid();
 778             close( sync_pipe[0] );
 779
 780             acquire_lock();
 781
 782             /* close stdin and stdout */
 783             dup2( fd, 0 );
 784             dup2( fd, 1 );
 785
 786             /* signal parent */
 787             dummy = 0;
 788             write( sync_pipe[1], &dummy, 1 );
 789             close( sync_pipe[1] );
 790             break;
 791
 792         case -1:
 793             fatal_error( "fork: %s\n", strerror( errno ));
 794             break;
 795
 796         default:  /* parent */
 797             close( sync_pipe[1] );
 798
 799             /* wait for child to signal us and then exit */
 800             if (read( sync_pipe[0], &dummy, 1 ) == 1) _exit(0);
 801
 802             /* child terminated, propagate exit status */
 803             waitpid( pid, &status, 0 );
 804             if (WIFEXITED(status)) _exit( WEXITSTATUS(status) );
 805             _exit(1);
 806         }
 807     }
 808     else  /* remain in the foreground */
 809     {
 810         acquire_lock();
 811     }
 812
 813     /* init the process tracing mechanism */
 814     init_tracing_mechanism();
 815     close( fd );
 816 }
 817
 818 /* master socket timer expiration handler */
 819 static void close_socket_timeout( void *arg )
 820 {
 821     master_timeout = NULL;
 822     flush_registry();
 823     if (debug_level) fprintf( stderr, "wineserver: exiting (pid=%ld)\n", (long) getpid() );
 824
 825 #ifdef DEBUG_OBJECTS
 826     close_objects();  /* shut down everything properly */
 827 #endif
 828     exit( 0 );
 829 }
 830
 831 /* close the master socket and stop waiting for new clients */
 832 void close_master_socket( timeout_t timeout )
 833 {
 834     if (master_socket)
 835     {
 836         release_object( master_socket );
 837         master_socket = NULL;
 838     }
 839     if (master_timeout)  /* cancel previous timeout */
 840         remove_timeout_user( master_timeout );
 841
 842     master_timeout = add_timeout_user( timeout, close_socket_timeout, NULL );
 843 }