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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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 #include <pwd.h>
  28 #include <signal.h>
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <stdarg.h>
  32 #include <string.h>
  33 #include <sys/stat.h>
  34 #include <sys/time.h>
  35 #include <sys/types.h>
  36 #ifdef HAVE_SYS_SOCKET_H
  37 # include <sys/socket.h>
  38 #endif
  39 #include <sys/uio.h>
  40 #include <sys/un.h>
  41 #include <unistd.h>
  42
  43 #include "winnt.h"
  44 #include "winbase.h"
  45 #include "wincon.h"
  46 #include "thread.h"
  47 #include "process.h"
  48 #define WANT_REQUEST_HANDLERS
  49 #include "request.h"
  50
  51 /* Some versions of glibc don't define this */
  52 #ifndef SCM_RIGHTS
  53 #define SCM_RIGHTS 1
  54 #endif
  55
  56  /* path names for server master Unix socket */
  57 #define CONFDIR    "/.wine"        /* directory for Wine config relative to $HOME */
  58 #define SERVERDIR  "wineserver-"   /* server socket directory (hostname appended) */
  59 #define SOCKETNAME "socket"        /* name of the socket file */
  60
  61 struct master_socket
  62 {
  63     struct object        obj;         /* object header */
  64     struct timeout_user *timeout;    /* timeout on last process exit */
  65 };
  66
  67 static void master_socket_dump( struct object *obj, int verbose );
  68 static void master_socket_poll_event( struct object *obj, int event );
  69
  70 static const struct object_ops master_socket_ops =
  71 {
  72     sizeof(struct master_socket),  /* size */
  73     master_socket_dump,            /* dump */
  74     no_add_queue,                  /* add_queue */
  75     NULL,                          /* remove_queue */
  76     NULL,                          /* signaled */
  77     NULL,                          /* satisfied */
  78     NULL,                          /* get_poll_events */
  79     master_socket_poll_event,      /* poll_event */
  80     no_get_fd,                     /* get_fd */
  81     no_flush,                      /* flush */
  82     no_get_file_info,              /* get_file_info */
  83     NULL,                          /* queue_async */
  84     no_destroy                     /* destroy */
  85 };
  86
  87
  88 struct thread *current = NULL;  /* thread handling the current request */
  89 unsigned int global_error = 0;  /* global error code for when no thread is current */
  90 unsigned int server_start_ticks = 0;  /* tick count offset from server startup */
  91
  92 static struct master_socket *master_socket;  /* the master socket object */
  93
  94 /* socket communication static structures */
  95 static struct iovec myiovec;
  96 static struct msghdr msghdr;
  97 #ifndef HAVE_MSGHDR_ACCRIGHTS
  98 struct cmsg_fd
  99 {
 100     int len;   /* sizeof structure */
 101     int level; /* SOL_SOCKET */
 102     int type;  /* SCM_RIGHTS */
 103     int fd;    /* fd to pass */
 104 };
 105 static struct cmsg_fd cmsg = { sizeof(cmsg), SOL_SOCKET, SCM_RIGHTS, -1 };
 106 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 107
 108 /* complain about a protocol error and terminate the client connection */
 109 void fatal_protocol_error( struct thread *thread, const char *err, ... )
 110 {
 111     va_list args;
 112
 113     va_start( args, err );
 114     fprintf( stderr, "Protocol error:%p: ", thread );
 115     vfprintf( stderr, err, args );
 116     va_end( args );
 117     thread->exit_code = 1;
 118     kill_thread( thread, 1 );
 119 }
 120
 121 /* complain about a protocol error and terminate the client connection */
 122 void fatal_protocol_perror( struct thread *thread, const char *err, ... )
 123 {
 124     va_list args;
 125
 126     va_start( args, err );
 127     fprintf( stderr, "Protocol error:%p: ", thread );
 128     vfprintf( stderr, err, args );
 129     perror( " " );
 130     va_end( args );
 131     thread->exit_code = 1;
 132     kill_thread( thread, 1 );
 133 }
 134
 135 /* die on a fatal error */
 136 void fatal_error( const char *err, ... )
 137 {
 138     va_list args;
 139
 140     va_start( args, err );
 141     fprintf( stderr, "wineserver: " );
 142     vfprintf( stderr, err, args );
 143     va_end( args );
 144     exit(1);
 145 }
 146
 147 /* die on a fatal error */
 148 void fatal_perror( const char *err, ... )
 149 {
 150     va_list args;
 151
 152     va_start( args, err );
 153     fprintf( stderr, "wineserver: " );
 154     vfprintf( stderr, err, args );
 155     perror( " " );
 156     va_end( args );
 157     exit(1);
 158 }
 159
 160 /* allocate the reply data */
 161 void *set_reply_data_size( size_t size )
 162 {
 163     assert( size <= get_reply_max_size() );
 164     if (size && !(current->reply_data = mem_alloc( size ))) size = 0;
 165     current->reply_size = size;
 166     return current->reply_data;
 167 }
 168
 169 /* write the remaining part of the reply */
 170 void write_reply( struct thread *thread )
 171 {
 172     int ret;
 173
 174     if ((ret = write( thread->reply_fd,
 175                       (char *)thread->reply_data + thread->reply_size - thread->reply_towrite,
 176                       thread->reply_towrite )) >= 0)
 177     {
 178         if (!(thread->reply_towrite -= ret))
 179         {
 180             free( thread->reply_data );
 181             thread->reply_data = NULL;
 182             /* sent everything, can go back to waiting for requests */
 183             change_select_fd( &thread->obj, thread->request_fd, POLLIN );
 184         }
 185         return;
 186     }
 187     if (errno == EPIPE)
 188         kill_thread( thread, 0 );  /* normal death */
 189     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 190         fatal_protocol_perror( thread, "reply write" );
 191 }
 192
 193 /* send a reply to the current thread */
 194 static void send_reply( union generic_reply *reply )
 195 {
 196     int ret;
 197
 198     if (!current->reply_size)
 199     {
 200         if ((ret = write( current->reply_fd, reply, sizeof(*reply) )) != sizeof(*reply)) goto error;
 201     }
 202     else
 203     {
 204         struct iovec vec[2];
 205
 206         vec[0].iov_base = (void *)reply;
 207         vec[0].iov_len  = sizeof(*reply);
 208         vec[1].iov_base = current->reply_data;
 209         vec[1].iov_len  = current->reply_size;
 210
 211         if ((ret = writev( current->reply_fd, vec, 2 )) < sizeof(*reply)) goto error;
 212
 213         if ((current->reply_towrite = current->reply_size - (ret - sizeof(*reply))))
 214         {
 215             /* couldn't write it all, wait for POLLOUT */
 216             change_select_fd( &current->obj, current->reply_fd, POLLOUT );
 217             return;
 218         }
 219     }
 220     if (current->reply_data)
 221     {
 222         free( current->reply_data );
 223         current->reply_data = NULL;
 224     }
 225     return;
 226
 227  error:
 228     if (ret >= 0)
 229         fatal_protocol_error( current, "partial write %d\n", ret );
 230     else if (errno == EPIPE)
 231         kill_thread( current, 0 );  /* normal death */
 232     else
 233         fatal_protocol_perror( current, "reply write" );
 234 }
 235
 236 /* call a request handler */
 237 static void call_req_handler( struct thread *thread )
 238 {
 239     union generic_reply reply;
 240     enum request req = thread->req.request_header.req;
 241
 242     current = thread;
 243     current->reply_size = 0;
 244     clear_error();
 245     memset( &reply, 0, sizeof(reply) );
 246
 247     if (debug_level) trace_request();
 248
 249     if (req < REQ_NB_REQUESTS)
 250     {
 251         req_handlers[req]( &current->req, &reply );
 252         if (current)
 253         {
 254             reply.reply_header.error = current->error;
 255             reply.reply_header.reply_size = current->reply_size;
 256             if (debug_level) trace_reply( req, &reply );
 257             send_reply( &reply );
 258         }
 259         current = NULL;
 260         return;
 261     }
 262     fatal_protocol_error( current, "bad request %d\n", req );
 263 }
 264
 265 /* read a request from a thread */
 266 void read_request( struct thread *thread )
 267 {
 268     int ret;
 269
 270     if (!thread->req_toread)  /* no pending request */
 271     {
 272         if ((ret = read( thread->obj.fd, &thread->req,
 273                          sizeof(thread->req) )) != sizeof(thread->req)) goto error;
 274         if (!(thread->req_toread = thread->req.request_header.request_size))
 275         {
 276             /* no data, handle request at once */
 277             call_req_handler( thread );
 278             return;
 279         }
 280         if (!(thread->req_data = malloc( thread->req_toread )))
 281             fatal_protocol_error( thread, "no memory for %d bytes request\n", thread->req_toread );
 282     }
 283
 284     /* read the variable sized data */
 285     for (;;)
 286     {
 287         ret = read( thread->obj.fd, ((char *)thread->req_data +
 288                                      thread->req.request_header.request_size - thread->req_toread),
 289                     thread->req_toread );
 290         if (ret <= 0) break;
 291         if (!(thread->req_toread -= ret))
 292         {
 293             call_req_handler( thread );
 294             free( thread->req_data );
 295             thread->req_data = NULL;
 296             return;
 297         }
 298     }
 299
 300 error:
 301     if (!ret)  /* closed pipe */
 302         kill_thread( thread, 0 );
 303     else if (ret > 0)
 304         fatal_protocol_error( thread, "partial read %d\n", ret );
 305     else if (errno != EWOULDBLOCK && errno != EAGAIN)
 306         fatal_protocol_perror( thread, "read" );
 307 }
 308
 309 /* receive a file descriptor on the process socket */
 310 int receive_fd( struct process *process )
 311 {
 312     struct send_fd data;
 313     int fd, ret;
 314
 315 #ifdef HAVE_MSGHDR_ACCRIGHTS
 316     msghdr.msg_accrightslen = sizeof(int);
 317     msghdr.msg_accrights = (void *)&fd;
 318 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 319     msghdr.msg_control    = &cmsg;
 320     msghdr.msg_controllen = sizeof(cmsg);
 321     cmsg.fd = -1;
 322 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 323
 324     myiovec.iov_base = (void *)&data;
 325     myiovec.iov_len  = sizeof(data);
 326
 327     ret = recvmsg( process->obj.fd, &msghdr, 0 );
 328 #ifndef HAVE_MSGHDR_ACCRIGHTS
 329     fd = cmsg.fd;
 330 #endif
 331
 332     if (ret == sizeof(data))
 333     {
 334         struct thread *thread;
 335
 336         if (data.tid) thread = get_thread_from_id( data.tid );
 337         else thread = (struct thread *)grab_object( process->thread_list );
 338
 339         if (!thread || thread->process != process)
 340         {
 341             if (debug_level)
 342                 fprintf( stderr, "%08x: *fd* %d <- %d bad thread id\n",
 343                          (unsigned int)data.tid, data.fd, fd );
 344             close( fd );
 345         }
 346         else
 347         {
 348             if (debug_level)
 349                 fprintf( stderr, "%08x: *fd* %d <- %d\n",
 350                          (unsigned int)thread, data.fd, fd );
 351             thread_add_inflight_fd( thread, data.fd, fd );
 352         }
 353         if (thread) release_object( thread );
 354         return 0;
 355     }
 356
 357     if (ret >= 0)
 358     {
 359         if (ret > 0)
 360             fprintf( stderr, "Protocol error: process %p: partial recvmsg %d for fd\n",
 361                      process, ret );
 362         kill_process( process, NULL, 1 );
 363     }
 364     else
 365     {
 366         if (errno != EWOULDBLOCK && errno != EAGAIN)
 367         {
 368             fprintf( stderr, "Protocol error: process %p: ", process );
 369             perror( "recvmsg" );
 370             kill_process( process, NULL, 1 );
 371         }
 372     }
 373     return -1;
 374 }
 375
 376 /* send an fd to a client */
 377 int send_client_fd( struct process *process, int fd, obj_handle_t handle )
 378 {
 379     int ret;
 380
 381     if (debug_level)
 382         fprintf( stderr, "%08x: *fd* %d -> %d\n", (unsigned int)current, handle, fd );
 383
 384 #ifdef HAVE_MSGHDR_ACCRIGHTS
 385     msghdr.msg_accrightslen = sizeof(fd);
 386     msghdr.msg_accrights = (void *)&fd;
 387 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 388     msghdr.msg_control    = &cmsg;
 389     msghdr.msg_controllen = sizeof(cmsg);
 390     cmsg.fd = fd;
 391 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 392
 393     myiovec.iov_base = (void *)&handle;
 394     myiovec.iov_len  = sizeof(handle);
 395
 396     ret = sendmsg( process->obj.fd, &msghdr, 0 );
 397
 398     if (ret == sizeof(handle)) return 0;
 399
 400     if (ret >= 0)
 401     {
 402         if (ret > 0)
 403             fprintf( stderr, "Protocol error: process %p: partial sendmsg %d\n", process, ret );
 404         kill_process( process, NULL, 1 );
 405     }
 406     else
 407     {
 408         fprintf( stderr, "Protocol error: process %p: ", process );
 409         perror( "sendmsg" );
 410         kill_process( process, NULL, 1 );
 411     }
 412     return -1;
 413 }
 414
 415 /* get current tick count to return to client */
 416 unsigned int get_tick_count(void)
 417 {
 418     struct timeval t;
 419     gettimeofday( &t, NULL );
 420     return (t.tv_sec * 1000) + (t.tv_usec / 1000) - server_start_ticks;
 421 }
 422
 423 static void master_socket_dump( struct object *obj, int verbose )
 424 {
 425     struct master_socket *sock = (struct master_socket *)obj;
 426     assert( obj->ops == &master_socket_ops );
 427     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 428 }
 429
 430 /* handle a socket event */
 431 static void master_socket_poll_event( struct object *obj, int event )
 432 {
 433     struct master_socket *sock = (struct master_socket *)obj;
 434     assert( obj->ops == &master_socket_ops );
 435
 436     assert( sock == master_socket );  /* there is only one master socket */
 437
 438     if (event & (POLLERR | POLLHUP))
 439     {
 440         /* this is not supposed to happen */
 441         fprintf( stderr, "wineserver: Error on master socket\n" );
 442         release_object( obj );
 443     }
 444     else if (event & POLLIN)
 445     {
 446         struct sockaddr_un dummy;
 447         int len = sizeof(dummy);
 448         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 449         if (client == -1) return;
 450         if (sock->timeout)
 451         {
 452             remove_timeout_user( sock->timeout );
 453             sock->timeout = NULL;
 454         }
 455         fcntl( client, F_SETFL, O_NONBLOCK );
 456         create_process( client );
 457     }
 458 }
 459
 460 /* remove the socket upon exit */
 461 static void socket_cleanup(void)
 462 {
 463     static int do_it_once;
 464     if (!do_it_once++) unlink( SOCKETNAME );
 465 }
 466
 467 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 468 const char *get_config_dir(void)
 469 {
 470     static char *confdir;
 471     if (!confdir)
 472     {
 473         const char *prefix = getenv( "WINEPREFIX" );
 474         if (prefix)
 475         {
 476             int len = strlen(prefix);
 477             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 478             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 479         }
 480         else
 481         {
 482             const char *home = getenv( "HOME" );
 483             if (!home)
 484             {
 485                 struct passwd *pwd = getpwuid( getuid() );
 486                 if (!pwd) fatal_error( "could not find your home directory\n" );
 487                 home = pwd->pw_dir;
 488             }
 489             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 490                 fatal_error( "out of memory\n" );
 491             strcpy( confdir, home );
 492             strcat( confdir, CONFDIR );
 493         }
 494     }
 495     return confdir;
 496 }
 497
 498 /* create the server directory and chdir to it */
 499 static void create_server_dir(void)
 500 {
 501     char hostname[64];
 502     char *serverdir;
 503     const char *confdir = get_config_dir();
 504     struct stat st;
 505
 506     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 507
 508     if (!(serverdir = malloc( strlen(SERVERDIR) + strlen(hostname) + 1 )))
 509         fatal_error( "out of memory\n" );
 510
 511     if (chdir( confdir ) == -1) fatal_perror( "chdir %s", confdir );
 512
 513     strcpy( serverdir, SERVERDIR );
 514     strcat( serverdir, hostname );
 515
 516     if (chdir( serverdir ) == -1)
 517     {
 518         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 519         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 520         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 521     }
 522     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 523     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 524     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 525     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 526 }
 527
 528 /* open the master server socket and start waiting for new clients */
 529 void open_master_socket(void)
 530 {
 531     struct sockaddr_un addr;
 532     int fd, slen;
 533
 534     /* make sure no request is larger than the maximum size */
 535     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 536     assert( sizeof(union generic_reply) == sizeof(struct request_max_size) );
 537
 538     create_server_dir();
 539     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 540     addr.sun_family = AF_UNIX;
 541     strcpy( addr.sun_path, SOCKETNAME );
 542     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 543 #ifdef HAVE_SOCKADDR_SUN_LEN
 544     addr.sun_len = slen;
 545 #endif
 546     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 547     {
 548         if ((errno == EEXIST) || (errno == EADDRINUSE))
 549             exit(0);  /* pretend we succeeded to start */
 550         else
 551             fatal_perror( "bind" );
 552     }
 553     atexit( socket_cleanup );
 554
 555     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 556     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 557
 558     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 559         fatal_error( "out of memory\n" );
 560     master_socket->timeout = NULL;
 561     set_select_events( &master_socket->obj, POLLIN );
 562
 563     /* setup msghdr structure constant fields */
 564     msghdr.msg_name    = NULL;
 565     msghdr.msg_namelen = 0;
 566     msghdr.msg_iov     = &myiovec;
 567     msghdr.msg_iovlen  = 1;
 568
 569     /* init startup ticks */
 570     server_start_ticks = get_tick_count();
 571
 572     /* go in the background */
 573     switch(fork())
 574     {
 575     case -1:
 576         fatal_perror( "fork" );
 577     case 0:
 578         setsid();
 579         break;
 580     default:
 581         _exit(0);  /* do not call atexit functions */
 582     }
 583 }
 584
 585 /* master socket timer expiration handler */
 586 static void close_socket_timeout( void *arg )
 587 {
 588     /* if a new client is waiting, we keep on running */
 589     if (!check_select_events( master_socket->obj.fd, POLLIN ))
 590         release_object( master_socket );
 591 }
 592
 593 /* close the master socket and stop waiting for new clients */
 594 void close_master_socket(void)
 595 {
 596     struct timeval when;
 597
 598     if (master_socket_timeout == -1) return;  /* just keep running forever */
 599
 600     if (master_socket_timeout)
 601     {
 602         gettimeofday( &when, 0 );
 603         add_timeout( &when, master_socket_timeout * 1000 );
 604         master_socket->timeout = add_timeout_user( &when, close_socket_timeout, NULL );
 605     }
 606     else close_socket_timeout( NULL );  /* close it right away */
 607 }
 608
 609 /* lock/unlock the master socket to stop accepting new clients */
 610 void lock_master_socket( int locked )
 611 {
 612     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 613 }