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