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