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 #include "thread.h"
  69 #include "security.h"
  70 #define WANT_REQUEST_HANDLERS
  71 #include "request.h"
  72
  73 /* Some versions of glibc don't define this */
  74 #ifndef SCM_RIGHTS
  75 #define SCM_RIGHTS 1
  76 #endif
  77
  78 /* path names for server master Unix socket */
  79 static const char * const server_socket_name = "socket";   /* name of the socket file */
  80 static const char * const server_lock_name = "lock";       /* name of the server lock file */
  81
  82 struct master_socket
  83 {
  84     struct object        obj;        /* object header */
  85     struct fd           *fd;         /* file descriptor of the master socket */
  86 };
  87
  88 static void master_socket_dump( struct object *obj, int verbose );
  89 static void master_socket_destroy( struct object *obj );
  90 static void master_socket_poll_event( struct fd *fd, int event );
  91
  92 static const struct object_ops master_socket_ops =
  93 {
  94     sizeof(struct master_socket),  /* size */
  95     master_socket_dump,            /* dump */
  96     no_get_type,                   /* get_type */
  97     no_add_queue,                  /* add_queue */
  98     NULL,                          /* remove_queue */
  99     NULL,                          /* signaled */
 100     NULL,                          /* satisfied */
 101     no_signal,                     /* signal */
 102     no_get_fd,                     /* get_fd */
 103     no_map_access,                 /* map_access */
 104     default_get_sd,                /* get_sd */
 105     default_set_sd,                /* set_sd */
 106     no_lookup_name,                /* lookup_name */
 107     no_link_name,                  /* link_name */
 108     NULL,                          /* unlink_name */
 109     no_open_file,                  /* open_file */
 110     no_close_handle,               /* close_handle */
 111     master_socket_destroy          /* destroy */
 112 };
 113
 114 static const struct fd_ops master_socket_fd_ops =
 115 {
 116     NULL,                          /* get_poll_events */
 117     master_socket_poll_event,      /* poll_event */
 118     NULL,                          /* flush */
 119     NULL,                          /* get_fd_type */
 120     NULL,                          /* ioctl */
 121     NULL,                          /* queue_async */
 122     NULL,                          /* reselect_async */
 123     NULL                           /* cancel_async */
 124 };
 125
 126
 127 struct thread *current = NULL;  /* thread handling the current request */
 128 unsigned int global_error = 0;  /* global error code for when no thread is current */
 129 timeout_t server_start_time = 0;  /* server startup time */
 130 int server_dir_fd = -1;    /* file descriptor for the server dir */
 131 int config_dir_fd = -1;    /* file descriptor for the config dir */
 132
 133 static struct master_socket *master_socket;  /* the master socket object */
 134 static struct timeout_user *master_timeout;
 135
 136 /* complain about a protocol error and terminate the client connection */
 137 void fatal_protocol_error( struct thread *thread, const char *err, ... )
 138 {
 139     va_list args;
 140
 141     va_start( args, err );
 142     fprintf( stderr, "Protocol error:%04x: ", thread->id );
 143     vfprintf( stderr, err, args );
 144     va_end( args );
 145     thread->exit_code = 1;
 146     kill_thread( thread, 1 );
 147 }
 148
 149 /* die on a fatal error */
 150 void fatal_error( const char *err, ... )
 151 {
 152     va_list args;
 153
 154     va_start( args, err );
 155     fprintf( stderr, "wineserver: " );
 156     vfprintf( stderr, err, args );
 157     va_end( args );
 158     exit(1);
 159 }
 160
 161 /* allocate the reply data */
 162 void *set_reply_data_size( data_size_t size )
 163 {
 164     assert( size <= get_reply_max_size() );
 165     if (size && !(current->reply_data = mem_alloc( size ))) size = 0;
 166     current->reply_size = size;
 167     return current->reply_data;
 168 }
 169
 170 /* return object attributes from the current request */
 171 const struct object_attributes *get_req_object_attributes( const struct security_descriptor **sd,
 172                                                            struct unicode_str *name,
 173                                                            struct object **root )
 174 {
 175     static const struct object_attributes empty_attributes;
 176     const struct object_attributes *attr = get_req_data();
 177     data_size_t size = get_req_data_size();
 178
 179     if (root) *root = NULL;
 180
 181     if (!size)
 182     {
 183         *sd = NULL;
 184         name->len = 0;
 185         return &empty_attributes;
 186     }
 187
 188     if ((size < sizeof(*attr)) || (size - sizeof(*attr) < attr->sd_len) ||
 189         (size - sizeof(*attr) - attr->sd_len < attr->name_len))
 190     {
 191         set_error( STATUS_ACCESS_VIOLATION );
 192         return NULL;
 193     }
 194     if (attr->sd_len && !sd_is_valid( (const struct security_descriptor *)(attr + 1), attr->sd_len ))
 195     {
 196         set_error( STATUS_INVALID_SECURITY_DESCR );
 197         return NULL;
 198     }
 199     if ((attr->name_len & (sizeof(WCHAR) - 1)) || attr->name_len >= 65534)
 200     {
 201         set_error( STATUS_OBJECT_NAME_INVALID );
 202         return NULL;
 203     }
 204     if (root && attr->rootdir && attr->name_len)
 205     {
 206         if (!(*root = get_directory_obj( current->process, attr->rootdir ))) return NULL;
 207     }
 208     *sd = attr->sd_len ? (const struct security_descriptor *)(attr + 1) : NULL;
 209     name->len = attr->name_len;
 210     name->str = (const WCHAR *)(attr + 1) + attr->sd_len / sizeof(WCHAR);
 211     return attr;
 212 }
 213
 214 /* return a pointer to the request data following an object attributes structure */
 215 const void *get_req_data_after_objattr( const struct object_attributes *attr, data_size_t *len )
 216 {
 217     const void *ptr = (const WCHAR *)((const struct object_attributes *)get_req_data() + 1) +
 218                        attr->sd_len / sizeof(WCHAR) + attr->name_len / sizeof(WCHAR);
 219     *len = get_req_data_size() - ((const char *)ptr - (const char *)get_req_data());
 220     return ptr;
 221 }
 222
 223 /* write the remaining part of the reply */
 224 void write_reply( struct thread *thread )
 225 {
 226     int ret;
 227
 228     if ((ret = write( get_unix_fd( thread->reply_fd ),
 229                       (char *)thread->reply_data + thread->reply_size - thread->reply_towrite,
 230                       thread->reply_towrite )) >= 0)
 231     {
 232         if (!(thread->reply_towrite -= ret))
 233         {
 234             free( thread->reply_data );
 235             thread->reply_data = NULL;
 236             /* sent everything, can go back to waiting for requests */
 237             set_fd_events( thread->request_fd, POLLIN );
 238             set_fd_events( thread->reply_fd, 0 );
 239         }
 240         return;
 241     }
 242     if (errno == EPIPE)
 243         kill_thread( thread, 0 );  /* normal death */
 244     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 245         fatal_protocol_error( thread, "reply write: %s\n", strerror( errno ));
 246 }
 247
 248 /* send a reply to the current thread */
 249 static void send_reply( union generic_reply *reply )
 250 {
 251     int ret;
 252
 253     if (!current->reply_size)
 254     {
 255         if ((ret = write( get_unix_fd( current->reply_fd ),
 256                           reply, sizeof(*reply) )) != sizeof(*reply)) goto error;
 257     }
 258     else
 259     {
 260         struct iovec vec[2];
 261
 262         vec[0].iov_base = (void *)reply;
 263         vec[0].iov_len  = sizeof(*reply);
 264         vec[1].iov_base = current->reply_data;
 265         vec[1].iov_len  = current->reply_size;
 266
 267         if ((ret = writev( get_unix_fd( current->reply_fd ), vec, 2 )) < sizeof(*reply)) goto error;
 268
 269         if ((current->reply_towrite = current->reply_size - (ret - sizeof(*reply))))
 270         {
 271             /* couldn't write it all, wait for POLLOUT */
 272             set_fd_events( current->reply_fd, POLLOUT );
 273             set_fd_events( current->request_fd, 0 );
 274             return;
 275         }
 276     }
 277     free( current->reply_data );
 278     current->reply_data = NULL;
 279     return;
 280
 281  error:
 282     if (ret >= 0)
 283         fatal_protocol_error( current, "partial write %d\n", ret );
 284     else if (errno == EPIPE)
 285         kill_thread( current, 0 );  /* normal death */
 286     else
 287         fatal_protocol_error( current, "reply write: %s\n", strerror( errno ));
 288 }
 289
 290 /* call a request handler */
 291 static void call_req_handler( struct thread *thread )
 292 {
 293     union generic_reply reply;
 294     enum request req = thread->req.request_header.req;
 295
 296     current = thread;
 297     current->reply_size = 0;
 298     clear_error();
 299     memset( &reply, 0, sizeof(reply) );
 300
 301     if (debug_level) trace_request();
 302
 303     if (req < REQ_NB_REQUESTS)
 304         req_handlers[req]( &current->req, &reply );
 305     else
 306         set_error( STATUS_NOT_IMPLEMENTED );
 307
 308     if (current)
 309     {
 310         if (current->reply_fd)
 311         {
 312             reply.reply_header.error = current->error;
 313             reply.reply_header.reply_size = current->reply_size;
 314             if (debug_level) trace_reply( req, &reply );
 315             send_reply( &reply );
 316         }
 317         else
 318         {
 319             current->exit_code = 1;
 320             kill_thread( current, 1 );  /* no way to continue without reply fd */
 321         }
 322     }
 323     current = NULL;
 324 }
 325
 326 /* read a request from a thread */
 327 void read_request( struct thread *thread )
 328 {
 329     int ret;
 330
 331     if (!thread->req_toread)  /* no pending request */
 332     {
 333         if ((ret = read( get_unix_fd( thread->request_fd ), &thread->req,
 334                          sizeof(thread->req) )) != sizeof(thread->req)) goto error;
 335         if (!(thread->req_toread = thread->req.request_header.request_size))
 336         {
 337             /* no data, handle request at once */
 338             call_req_handler( thread );
 339             return;
 340         }
 341         if (!(thread->req_data = malloc( thread->req_toread )))
 342         {
 343             fatal_protocol_error( thread, "no memory for %u bytes request %d\n",
 344                                   thread->req_toread, thread->req.request_header.req );
 345             return;
 346         }
 347     }
 348
 349     /* read the variable sized data */
 350     for (;;)
 351     {
 352         ret = read( get_unix_fd( thread->request_fd ),
 353                     (char *)thread->req_data + thread->req.request_header.request_size
 354                       - thread->req_toread,
 355                     thread->req_toread );
 356         if (ret <= 0) break;
 357         if (!(thread->req_toread -= ret))
 358         {
 359             call_req_handler( thread );
 360             free( thread->req_data );
 361             thread->req_data = NULL;
 362             return;
 363         }
 364     }
 365
 366 error:
 367     if (!ret)  /* closed pipe */
 368         kill_thread( thread, 0 );
 369     else if (ret > 0)
 370         fatal_protocol_error( thread, "partial read %d\n", ret );
 371     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 372         fatal_protocol_error( thread, "read: %s\n", strerror( errno ));
 373 }
 374
 375 /* receive a file descriptor on the process socket */
 376 int receive_fd( struct process *process )
 377 {
 378     struct iovec vec;
 379     struct send_fd data;
 380     struct msghdr msghdr;
 381     int fd = -1, ret;
 382
 383 #ifdef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 384     msghdr.msg_accrightslen = sizeof(int);
 385     msghdr.msg_accrights = (void *)&fd;
 386 #else  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 387     char cmsg_buffer[256];
 388     msghdr.msg_control    = cmsg_buffer;
 389     msghdr.msg_controllen = sizeof(cmsg_buffer);
 390     msghdr.msg_flags      = 0;
 391 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 392
 393     msghdr.msg_name    = NULL;
 394     msghdr.msg_namelen = 0;
 395     msghdr.msg_iov     = &vec;
 396     msghdr.msg_iovlen  = 1;
 397     vec.iov_base = (void *)&data;
 398     vec.iov_len  = sizeof(data);
 399
 400     ret = recvmsg( get_unix_fd( process->msg_fd ), &msghdr, 0 );
 401
 402 #ifndef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 403     if (ret > 0)
 404     {
 405         struct cmsghdr *cmsg;
 406         for (cmsg = CMSG_FIRSTHDR( &msghdr ); cmsg; cmsg = CMSG_NXTHDR( &msghdr, cmsg ))
 407         {
 408             if (cmsg->cmsg_level != SOL_SOCKET) continue;
 409             if (cmsg->cmsg_type == SCM_RIGHTS) fd = *(int *)CMSG_DATA(cmsg);
 410         }
 411     }
 412 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 413
 414     if (ret == sizeof(data))
 415     {
 416         struct thread *thread;
 417
 418         if (data.tid) thread = get_thread_from_id( data.tid );
 419         else thread = (struct thread *)grab_object( get_process_first_thread( process ));
 420
 421         if (!thread || thread->process != process || thread->state == TERMINATED)
 422         {
 423             if (debug_level)
 424                 fprintf( stderr, "%04x: *fd* %d <- %d bad thread id\n",
 425                          data.tid, data.fd, fd );
 426             close( fd );
 427         }
 428         else
 429         {
 430             if (debug_level)
 431                 fprintf( stderr, "%04x: *fd* %d <- %d\n",
 432                          thread->id, data.fd, fd );
 433             thread_add_inflight_fd( thread, data.fd, fd );
 434         }
 435         if (thread) release_object( thread );
 436         return 0;
 437     }
 438
 439     if (!ret)
 440     {
 441         kill_process( process, 0 );
 442     }
 443     else if (ret > 0)
 444     {
 445         fprintf( stderr, "Protocol error: process %04x: partial recvmsg %d for fd\n",
 446                  process->id, ret );
 447         if (fd != -1) close( fd );
 448         kill_process( process, 1 );
 449     }
 450     else
 451     {
 452         if (errno != EWOULDBLOCK && errno != EAGAIN)
 453         {
 454             fprintf( stderr, "Protocol error: process %04x: ", process->id );
 455             perror( "recvmsg" );
 456             kill_process( process, 1 );
 457         }
 458     }
 459     return -1;
 460 }
 461
 462 /* send an fd to a client */
 463 int send_client_fd( struct process *process, int fd, obj_handle_t handle )
 464 {
 465     struct iovec vec;
 466     struct msghdr msghdr;
 467     int ret;
 468
 469 #ifdef HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS
 470     msghdr.msg_accrightslen = sizeof(fd);
 471     msghdr.msg_accrights = (void *)&fd;
 472 #else  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 473     char cmsg_buffer[256];
 474     struct cmsghdr *cmsg;
 475     msghdr.msg_control    = cmsg_buffer;
 476     msghdr.msg_controllen = sizeof(cmsg_buffer);
 477     msghdr.msg_flags      = 0;
 478     cmsg = CMSG_FIRSTHDR( &msghdr );
 479     cmsg->cmsg_len   = CMSG_LEN( sizeof(fd) );
 480     cmsg->cmsg_level = SOL_SOCKET;
 481     cmsg->cmsg_type  = SCM_RIGHTS;
 482     *(int *)CMSG_DATA(cmsg) = fd;
 483     msghdr.msg_controllen = cmsg->cmsg_len;
 484 #endif  /* HAVE_STRUCT_MSGHDR_MSG_ACCRIGHTS */
 485
 486     msghdr.msg_name    = NULL;
 487     msghdr.msg_namelen = 0;
 488     msghdr.msg_iov     = &vec;
 489     msghdr.msg_iovlen  = 1;
 490
 491     vec.iov_base = (void *)&handle;
 492     vec.iov_len  = sizeof(handle);
 493
 494     if (debug_level)
 495         fprintf( stderr, "%04x: *fd* %04x -> %d\n", current ? current->id : process->id, handle, fd );
 496
 497     ret = sendmsg( get_unix_fd( process->msg_fd ), &msghdr, 0 );
 498
 499     if (ret == sizeof(handle)) return 0;
 500
 501     if (ret >= 0)
 502     {
 503         fprintf( stderr, "Protocol error: process %04x: partial sendmsg %d\n", process->id, ret );
 504         kill_process( process, 1 );
 505     }
 506     else if (errno == EPIPE)
 507     {
 508         kill_process( process, 0 );
 509     }
 510     else
 511     {
 512         fprintf( stderr, "Protocol error: process %04x: ", process->id );
 513         perror( "sendmsg" );
 514         kill_process( process, 1 );
 515     }
 516     return -1;
 517 }
 518
 519 /* get current tick count to return to client */
 520 unsigned int get_tick_count(void)
 521 {
 522 #ifdef HAVE_CLOCK_GETTIME
 523     struct timespec ts;
 524 #ifdef CLOCK_MONOTONIC_RAW
 525     if (!clock_gettime( CLOCK_MONOTONIC_RAW, &ts ))
 526         return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
 527 #endif
 528     if (!clock_gettime( CLOCK_MONOTONIC, &ts ))
 529         return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
 530 #elif defined(__APPLE__)
 531     static mach_timebase_info_data_t timebase;
 532
 533     if (!timebase.denom) mach_timebase_info( &timebase );
 534     return mach_absolute_time() * timebase.numer / timebase.denom / 1000000;
 535 #endif
 536     return (current_time - server_start_time) / 10000;
 537 }
 538
 539 static void master_socket_dump( struct object *obj, int verbose )
 540 {
 541     struct master_socket *sock = (struct master_socket *)obj;
 542     assert( obj->ops == &master_socket_ops );
 543     fprintf( stderr, "Master socket fd=%p\n", sock->fd );
 544 }
 545
 546 static void master_socket_destroy( struct object *obj )
 547 {
 548     struct master_socket *sock = (struct master_socket *)obj;
 549     assert( obj->ops == &master_socket_ops );
 550     release_object( sock->fd );
 551 }
 552
 553 /* handle a socket event */
 554 static void master_socket_poll_event( struct fd *fd, int event )
 555 {
 556     struct master_socket *sock = get_fd_user( fd );
 557     assert( master_socket->obj.ops == &master_socket_ops );
 558
 559     assert( sock == master_socket );  /* there is only one master socket */
 560
 561     if (event & (POLLERR | POLLHUP))
 562     {
 563         /* this is not supposed to happen */
 564         fprintf( stderr, "wineserver: Error on master socket\n" );
 565         set_fd_events( sock->fd, -1 );
 566     }
 567     else if (event & POLLIN)
 568     {
 569         struct sockaddr_un dummy;
 570         socklen_t len = sizeof(dummy);
 571         int client = accept( get_unix_fd( master_socket->fd ), (struct sockaddr *) &dummy, &len );
 572         if (client == -1) return;
 573         fcntl( client, F_SETFL, O_NONBLOCK );
 574         create_process( client, NULL, 0 );
 575     }
 576 }
 577
 578 /* remove the socket upon exit */
 579 static void socket_cleanup(void)
 580 {
 581     static int do_it_once;
 582     if (!do_it_once++) unlink( server_socket_name );
 583 }
 584
 585 /* create a directory and check its permissions */
 586 static void create_dir( const char *name, struct stat *st )
 587 {
 588     if (lstat( name, st ) == -1)
 589     {
 590         if (errno != ENOENT)
 591             fatal_error( "lstat %s: %s", name, strerror( errno ));
 592         if (mkdir( name, 0700 ) == -1 && errno != EEXIST)
 593             fatal_error( "mkdir %s: %s\n", name, strerror( errno ));
 594         if (lstat( name, st ) == -1)
 595             fatal_error( "lstat %s: %s\n", name, strerror( errno ));
 596     }
 597     if (!S_ISDIR(st->st_mode)) fatal_error( "%s is not a directory\n", name );
 598     if (st->st_uid != getuid()) fatal_error( "%s is not owned by you\n", name );
 599     if (st->st_mode & 077) fatal_error( "%s must not be accessible by other users\n", name );
 600 }
 601
 602 /* create the server directory and chdir to it */
 603 static void create_server_dir( const char *dir )
 604 {
 605     char *p, *server_dir;
 606     struct stat st, st2;
 607
 608     if (!(server_dir = strdup( dir ))) fatal_error( "out of memory\n" );
 609
 610     /* first create the base directory if needed */
 611
 612     p = strrchr( server_dir, '/' );
 613     *p = 0;
 614     create_dir( server_dir, &st );
 615
 616     /* now create the server directory */
 617
 618     *p = '/';
 619     create_dir( server_dir, &st );
 620
 621     if (chdir( server_dir ) == -1)
 622         fatal_error( "chdir %s: %s\n", server_dir, strerror( errno ));
 623     if ((server_dir_fd = open( ".", O_RDONLY )) == -1)
 624         fatal_error( "open %s: %s\n", server_dir, strerror( errno ));
 625     if (fstat( server_dir_fd, &st2 ) == -1)
 626         fatal_error( "stat %s: %s\n", server_dir, strerror( errno ));
 627     if (st.st_dev != st2.st_dev || st.st_ino != st2.st_ino)
 628         fatal_error( "chdir did not end up in %s\n", server_dir );
 629
 630     free( server_dir );
 631 }
 632
 633 /* create the lock file and return its file descriptor */
 634 static int create_server_lock(void)
 635 {
 636     struct stat st;
 637     int fd;
 638
 639     if (lstat( server_lock_name, &st ) == -1)
 640     {
 641         if (errno != ENOENT)
 642             fatal_error( "lstat %s/%s: %s", wine_get_server_dir(), server_lock_name, strerror( errno ));
 643     }
 644     else
 645     {
 646         if (!S_ISREG(st.st_mode))
 647             fatal_error( "%s/%s is not a regular file\n", wine_get_server_dir(), server_lock_name );
 648     }
 649
 650     if ((fd = open( server_lock_name, O_CREAT|O_TRUNC|O_WRONLY, 0600 )) == -1)
 651         fatal_error( "error creating %s/%s: %s", wine_get_server_dir(), server_lock_name, strerror( errno ));
 652     return fd;
 653 }
 654
 655 /* wait for the server lock */
 656 int wait_for_lock(void)
 657 {
 658     const char *server_dir = wine_get_server_dir();
 659     int fd, r;
 660     struct flock fl;
 661
 662     if (!server_dir) return 0;  /* no server dir, so no lock to wait on */
 663
 664     create_server_dir( server_dir );
 665     fd = create_server_lock();
 666
 667     fl.l_type   = F_WRLCK;
 668     fl.l_whence = SEEK_SET;
 669     fl.l_start  = 0;
 670     fl.l_len    = 1;
 671     r = fcntl( fd, F_SETLKW, &fl );
 672     close(fd);
 673
 674     return r;
 675 }
 676
 677 /* kill the wine server holding the lock */
 678 int kill_lock_owner( int sig )
 679 {
 680     const char *server_dir = wine_get_server_dir();
 681     int fd, i, ret = 0;
 682     pid_t pid = 0;
 683     struct flock fl;
 684
 685     if (!server_dir) return 0;  /* no server dir, nothing to do */
 686
 687     create_server_dir( server_dir );
 688     fd = create_server_lock();
 689
 690     for (i = 1; i <= 20; i++)
 691     {
 692         fl.l_type   = F_WRLCK;
 693         fl.l_whence = SEEK_SET;
 694         fl.l_start  = 0;
 695         fl.l_len    = 1;
 696         if (fcntl( fd, F_GETLK, &fl ) == -1) goto done;
 697         if (fl.l_type != F_WRLCK) goto done;  /* the file is not locked */
 698         if (!pid)  /* first time around */
 699         {
 700             if (!(pid = fl.l_pid)) goto done;  /* shouldn't happen */
 701             if (sig == -1)
 702             {
 703                 if (kill( pid, SIGINT ) == -1) goto done;
 704                 kill( pid, SIGCONT );
 705                 ret = 1;
 706             }
 707             else  /* just send the specified signal and return */
 708             {
 709                 ret = (kill( pid, sig ) != -1);
 710                 goto done;
 711             }
 712         }
 713         else if (fl.l_pid != pid) goto done;  /* no longer the same process */
 714         usleep( 50000 * i );
 715     }
 716     /* waited long enough, now kill it */
 717     kill( pid, SIGKILL );
 718
 719  done:
 720     close( fd );
 721     return ret;
 722 }
 723
 724 /* acquire the main server lock */
 725 static void acquire_lock(void)
 726 {
 727     struct sockaddr_un addr;
 728     struct stat st;
 729     struct flock fl;
 730     int fd, slen, got_lock = 0;
 731
 732     fd = create_server_lock();
 733
 734     fl.l_type   = F_WRLCK;
 735     fl.l_whence = SEEK_SET;
 736     fl.l_start  = 0;
 737     fl.l_len    = 1;
 738     if (fcntl( fd, F_SETLK, &fl ) != -1)
 739     {
 740         /* check for crashed server */
 741         if (stat( server_socket_name, &st ) != -1 &&   /* there is a leftover socket */
 742             stat( "core", &st ) != -1 && st.st_size)   /* and there is a non-empty core file */
 743         {
 744             fprintf( stderr,
 745                      "Warning: a previous instance of the wine server seems to have crashed.\n"
 746                      "Please run 'gdb %s %s/core',\n"
 747                      "type 'backtrace' at the gdb prompt and report the results. Thanks.\n\n",
 748                      server_argv0, wine_get_server_dir() );
 749         }
 750         unlink( server_socket_name ); /* we got the lock, we can safely remove the socket */
 751         got_lock = 1;
 752         /* in that case we reuse fd without closing it, this ensures
 753          * that we hold the lock until the process exits */
 754     }
 755     else
 756     {
 757         switch(errno)
 758         {
 759         case ENOLCK:
 760             break;
 761         case EACCES:
 762             /* check whether locks work at all on this file system */
 763             if (fcntl( fd, F_GETLK, &fl ) == -1) break;
 764             /* fall through */
 765         case EAGAIN:
 766             exit(2); /* we didn't get the lock, exit with special status */
 767         default:
 768             fatal_error( "fcntl %s/%s: %s", wine_get_server_dir(), server_lock_name, strerror( errno ));
 769         }
 770         /* it seems we can't use locks on this fs, so we will use the socket existence as lock */
 771         close( fd );
 772     }
 773
 774     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_error( "socket: %s\n", strerror( errno ));
 775     addr.sun_family = AF_UNIX;
 776     strcpy( addr.sun_path, server_socket_name );
 777     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 778 #ifdef HAVE_STRUCT_SOCKADDR_UN_SUN_LEN
 779     addr.sun_len = slen;
 780 #endif
 781     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 782     {
 783         if ((errno == EEXIST) || (errno == EADDRINUSE))
 784         {
 785             if (got_lock)
 786                 fatal_error( "couldn't bind to the socket even though we hold the lock\n" );
 787             exit(2); /* we didn't get the lock, exit with special status */
 788         }
 789         fatal_error( "bind: %s\n", strerror( errno ));
 790     }
 791     atexit( socket_cleanup );
 792     chmod( server_socket_name, 0600 );  /* make sure no other user can connect */
 793     if (listen( fd, 5 ) == -1) fatal_error( "listen: %s\n", strerror( errno ));
 794
 795     if (!(master_socket = alloc_object( &master_socket_ops )) ||
 796         !(master_socket->fd = create_anonymous_fd( &master_socket_fd_ops, fd, &master_socket->obj, 0 )))
 797         fatal_error( "out of memory\n" );
 798     set_fd_events( master_socket->fd, POLLIN );
 799     make_object_static( &master_socket->obj );
 800 }
 801
 802 /* open the master server socket and start waiting for new clients */
 803 void open_master_socket(void)
 804 {
 805     const char *server_dir = wine_get_server_dir();
 806     const char *config_dir = wine_get_config_dir();
 807     int fd, pid, status, sync_pipe[2];
 808     char dummy;
 809
 810     /* make sure no request is larger than the maximum size */
 811     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 812     assert( sizeof(union generic_reply) == sizeof(struct request_max_size) );
 813
 814     /* make sure the stdio fds are open */
 815     fd = open( "/dev/null", O_RDWR );
 816     while (fd >= 0 && fd <= 2) fd = dup( fd );
 817
 818     if (!server_dir)
 819         fatal_error( "directory %s cannot be accessed\n", config_dir );
 820     if (chdir( config_dir ) == -1)
 821         fatal_error( "chdir to %s: %s\n", config_dir, strerror( errno ));
 822     if ((config_dir_fd = open( ".", O_RDONLY )) == -1)
 823         fatal_error( "open %s: %s\n", config_dir, strerror( errno ));
 824
 825     create_server_dir( server_dir );
 826
 827     if (!foreground)
 828     {
 829         if (pipe( sync_pipe ) == -1) fatal_error( "pipe: %s\n", strerror( errno ));
 830         pid = fork();
 831         switch( pid )
 832         {
 833         case 0:  /* child */
 834             setsid();
 835             close( sync_pipe[0] );
 836
 837             acquire_lock();
 838
 839             /* close stdin and stdout */
 840             dup2( fd, 0 );
 841             dup2( fd, 1 );
 842
 843             /* signal parent */
 844             dummy = 0;
 845             write( sync_pipe[1], &dummy, 1 );
 846             close( sync_pipe[1] );
 847             break;
 848
 849         case -1:
 850             fatal_error( "fork: %s\n", strerror( errno ));
 851             break;
 852
 853         default:  /* parent */
 854             close( sync_pipe[1] );
 855
 856             /* wait for child to signal us and then exit */
 857             if (read( sync_pipe[0], &dummy, 1 ) == 1) _exit(0);
 858
 859             /* child terminated, propagate exit status */
 860             waitpid( pid, &status, 0 );
 861             if (WIFEXITED(status)) _exit( WEXITSTATUS(status) );
 862             _exit(1);
 863         }
 864     }
 865     else  /* remain in the foreground */
 866     {
 867         acquire_lock();
 868     }
 869
 870     /* init the process tracing mechanism */
 871     init_tracing_mechanism();
 872     close( fd );
 873 }
 874
 875 /* master socket timer expiration handler */
 876 static void close_socket_timeout( void *arg )
 877 {
 878     master_timeout = NULL;
 879     flush_registry();
 880     if (debug_level) fprintf( stderr, "wineserver: exiting (pid=%ld)\n", (long) getpid() );
 881
 882 #ifdef DEBUG_OBJECTS
 883     close_objects();  /* shut down everything properly */
 884 #endif
 885     exit( 0 );
 886 }
 887
 888 /* close the master socket and stop waiting for new clients */
 889 void close_master_socket( timeout_t timeout )
 890 {
 891     if (master_socket)
 892     {
 893         release_object( master_socket );
 894         master_socket = NULL;
 895     }
 896     if (master_timeout)  /* cancel previous timeout */
 897         remove_timeout_user( master_timeout );
 898
 899     master_timeout = add_timeout_user( timeout, close_socket_timeout, NULL );
 900 }