server/request.c

   1 /*
   2  * Server-side request handling
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 #include <assert.h>
  10 #include <errno.h>
  11 #include <fcntl.h>
  12 #include <pwd.h>
  13 #include <signal.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <stdarg.h>
  17 #include <string.h>
  18 #include <sys/stat.h>
  19 #include <sys/time.h>
  20 #include <sys/types.h>
  21 #ifdef HAVE_SYS_SOCKET_H
  22 # include <sys/socket.h>
  23 #endif
  24 #include <sys/uio.h>
  25 #include <sys/un.h>
  26 #include <unistd.h>
  27
  28 #include "winnt.h"
  29 #include "winbase.h"
  30 #include "wincon.h"
  31 #include "thread.h"
  32 #include "process.h"
  33 #include "server.h"
  34 #define WANT_REQUEST_HANDLERS
  35 #include "request.h"
  36 #include "wine/port.h"
  37
  38 /* Some versions of glibc don't define this */
  39 #ifndef SCM_RIGHTS
  40 #define SCM_RIGHTS 1
  41 #endif
  42
  43  /* path names for server master Unix socket */
  44 #define CONFDIR    "/.wine"        /* directory for Wine config relative to $HOME */
  45 #define SERVERDIR  "/wineserver-"  /* server socket directory (hostname appended) */
  46 #define SOCKETNAME "socket"        /* name of the socket file */
  47
  48 struct master_socket
  49 {
  50     struct object       obj;         /* object header */
  51 };
  52
  53 static void master_socket_dump( struct object *obj, int verbose );
  54 static void master_socket_poll_event( struct object *obj, int event );
  55 static void master_socket_destroy( struct object *obj );
  56
  57 static const struct object_ops master_socket_ops =
  58 {
  59     sizeof(struct master_socket),  /* size */
  60     master_socket_dump,            /* dump */
  61     no_add_queue,                  /* add_queue */
  62     NULL,                          /* remove_queue */
  63     NULL,                          /* signaled */
  64     NULL,                          /* satisfied */
  65     NULL,                          /* get_poll_events */
  66     master_socket_poll_event,      /* poll_event */
  67     no_get_fd,                     /* get_fd */
  68     no_flush,                      /* flush */
  69     no_get_file_info,              /* get_file_info */
  70     master_socket_destroy          /* destroy */
  71 };
  72
  73
  74 struct request_socket
  75 {
  76     struct object       obj;         /* object header */
  77     struct thread      *thread;      /* owning thread */
  78 };
  79
  80 static void request_socket_dump( struct object *obj, int verbose );
  81 static void request_socket_poll_event( struct object *obj, int event );
  82
  83 static const struct object_ops request_socket_ops =
  84 {
  85     sizeof(struct request_socket), /* size */
  86     request_socket_dump,           /* dump */
  87     no_add_queue,                  /* add_queue */
  88     NULL,                          /* remove_queue */
  89     NULL,                          /* signaled */
  90     NULL,                          /* satisfied */
  91     NULL,                          /* get_poll_events */
  92     request_socket_poll_event,     /* poll_event */
  93     no_get_fd,                     /* get_fd */
  94     no_flush,                      /* flush */
  95     no_get_file_info,              /* get_file_info */
  96     no_destroy                     /* destroy */
  97 };
  98
  99
 100 struct thread *current = NULL;  /* thread handling the current request */
 101 unsigned int global_error = 0;  /* global error code for when no thread is current */
 102
 103 static struct master_socket *master_socket;  /* the master socket object */
 104
 105 /* socket communication static structures */
 106 static struct iovec myiovec;
 107 static struct msghdr msghdr;
 108 #ifndef HAVE_MSGHDR_ACCRIGHTS
 109 struct cmsg_fd
 110 {
 111     int len;   /* sizeof structure */
 112     int level; /* SOL_SOCKET */
 113     int type;  /* SCM_RIGHTS */
 114     int fd;    /* fd to pass */
 115 };
 116 static struct cmsg_fd cmsg = { sizeof(cmsg), SOL_SOCKET, SCM_RIGHTS, -1 };
 117 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 118
 119 /* complain about a protocol error and terminate the client connection */
 120 void fatal_protocol_error( struct thread *thread, const char *err, ... )
 121 {
 122     va_list args;
 123
 124     va_start( args, err );
 125     fprintf( stderr, "Protocol error:%p: ", thread );
 126     vfprintf( stderr, err, args );
 127     va_end( args );
 128     thread->exit_code = 1;
 129     kill_thread( thread, 1 );
 130 }
 131
 132 /* complain about a protocol error and terminate the client connection */
 133 void fatal_protocol_perror( struct thread *thread, const char *err, ... )
 134 {
 135     va_list args;
 136
 137     va_start( args, err );
 138     fprintf( stderr, "Protocol error:%p: ", thread );
 139     vfprintf( stderr, err, args );
 140     perror( " " );
 141     va_end( args );
 142     thread->exit_code = 1;
 143     kill_thread( thread, 1 );
 144 }
 145
 146 /* die on a fatal error */
 147 void fatal_error( const char *err, ... )
 148 {
 149     va_list args;
 150
 151     va_start( args, err );
 152     fprintf( stderr, "wineserver: " );
 153     vfprintf( stderr, err, args );
 154     va_end( args );
 155     exit(1);
 156 }
 157
 158 /* die on a fatal error */
 159 void fatal_perror( const char *err, ... )
 160 {
 161     va_list args;
 162
 163     va_start( args, err );
 164     fprintf( stderr, "wineserver: " );
 165     vfprintf( stderr, err, args );
 166     perror( " " );
 167     va_end( args );
 168     exit(1);
 169 }
 170
 171 /* call a request handler */
 172 static inline void call_req_handler( struct thread *thread, union generic_request *request )
 173 {
 174     enum request req = request->header.req;
 175
 176     current = thread;
 177     clear_error();
 178
 179     if (debug_level) trace_request( thread, request );
 180
 181     if (request->header.var_size)
 182     {
 183         if ((unsigned int)request->header.var_offset +
 184                           request->header.var_size > MAX_REQUEST_LENGTH)
 185         {
 186             fatal_protocol_error( current, "bad request offset/size %d/%d\n",
 187                                   request->header.var_offset, request->header.var_size );
 188             return;
 189         }
 190     }
 191
 192     if (req < REQ_NB_REQUESTS)
 193     {
 194         req_handlers[req]( request );
 195         if (current) send_reply( current, request );
 196         current = NULL;
 197         return;
 198     }
 199     fatal_protocol_error( current, "bad request %d\n", req );
 200 }
 201
 202 /* send a reply to a thread */
 203 void send_reply( struct thread *thread, union generic_request *request )
 204 {
 205     int ret;
 206
 207     assert (thread->pass_fd == -1);
 208
 209     if (debug_level) trace_reply( thread, request );
 210
 211     request->header.error = thread->error;
 212
 213     if ((ret = write( thread->reply_fd, request, sizeof(*request) )) != sizeof(*request))
 214     {
 215         if (ret >= 0)
 216             fatal_protocol_error( thread, "partial write %d\n", ret );
 217         else if (errno == EPIPE)
 218             kill_thread( thread, 0 );  /* normal death */
 219         else
 220             fatal_protocol_perror( thread, "sendmsg" );
 221     }
 222 }
 223
 224 /* read a message from a client that has something to say */
 225 void read_request( struct thread *thread )
 226 {
 227     union generic_request req;
 228     int ret;
 229
 230 #ifdef HAVE_MSGHDR_ACCRIGHTS
 231     msghdr.msg_accrightslen = sizeof(int);
 232     msghdr.msg_accrights = (void *)&thread->pass_fd;
 233 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 234     msghdr.msg_control    = &cmsg;
 235     msghdr.msg_controllen = sizeof(cmsg);
 236     cmsg.fd = -1;
 237 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 238
 239     assert( thread->pass_fd == -1 );
 240
 241     myiovec.iov_base = &req;
 242     myiovec.iov_len  = sizeof(req);
 243
 244     ret = recvmsg( thread->obj.fd, &msghdr, 0 );
 245 #ifndef HAVE_MSGHDR_ACCRIGHTS
 246     thread->pass_fd = cmsg.fd;
 247 #endif
 248
 249     if (ret == sizeof(req))
 250     {
 251         call_req_handler( thread, &req );
 252         thread->pass_fd = -1;
 253         return;
 254     }
 255     if (!ret)  /* closed pipe */
 256         kill_thread( thread, 0 );
 257     else if (ret > 0)
 258         fatal_protocol_error( thread, "partial recvmsg %d\n", ret );
 259     else
 260         fatal_protocol_perror( thread, "recvmsg" );
 261 }
 262
 263 /* send the wakeup signal to a thread */
 264 int send_thread_wakeup( struct thread *thread, int signaled )
 265 {
 266     int ret = write( thread->wait_fd, &signaled, sizeof(signaled) );
 267     if (ret == sizeof(signaled)) return 0;
 268     if (ret >= 0)
 269         fatal_protocol_error( thread, "partial wakeup write %d\n", ret );
 270     else if (errno == EPIPE)
 271         kill_thread( thread, 0 );  /* normal death */
 272     else
 273         fatal_protocol_perror( thread, "write" );
 274     return -1;
 275 }
 276
 277 /* send an fd to a client */
 278 int send_client_fd( struct thread *thread, int fd, handle_t handle )
 279 {
 280     int ret;
 281
 282     if (debug_level)
 283         fprintf( stderr, "%08x: *fd* %d = %d\n", (unsigned int)thread, handle, fd );
 284
 285 #ifdef HAVE_MSGHDR_ACCRIGHTS
 286     msghdr.msg_accrightslen = sizeof(fd);
 287     msghdr.msg_accrights = (void *)&fd;
 288 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 289     msghdr.msg_control    = &cmsg;
 290     msghdr.msg_controllen = sizeof(cmsg);
 291     cmsg.fd = fd;
 292 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 293
 294     myiovec.iov_base = (void *)&handle;
 295     myiovec.iov_len  = sizeof(handle);
 296
 297     ret = sendmsg( thread->obj.fd, &msghdr, 0 );
 298
 299     if (ret > 0) return 0;
 300     if (errno == EPIPE)
 301     {
 302         kill_thread( thread, 0 );  /* normal death */
 303     }
 304     else
 305     {
 306         fatal_protocol_perror( thread, "sendmsg" );
 307     }
 308     return -1;
 309 }
 310
 311 static void master_socket_dump( struct object *obj, int verbose )
 312 {
 313     struct master_socket *sock = (struct master_socket *)obj;
 314     assert( obj->ops == &master_socket_ops );
 315     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 316 }
 317
 318 /* handle a socket event */
 319 static void master_socket_poll_event( struct object *obj, int event )
 320 {
 321     struct master_socket *sock = (struct master_socket *)obj;
 322     assert( obj->ops == &master_socket_ops );
 323
 324     assert( sock == master_socket );  /* there is only one master socket */
 325
 326     if (event & (POLLERR | POLLHUP))
 327     {
 328         /* this is not supposed to happen */
 329         fprintf( stderr, "wineserver: Error on master socket\n" );
 330         release_object( obj );
 331     }
 332     else if (event & POLLIN)
 333     {
 334         struct sockaddr_un dummy;
 335         int len = sizeof(dummy);
 336         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 337         if (client != -1) create_process( client );
 338     }
 339 }
 340
 341 /* remove the socket upon exit */
 342 static void socket_cleanup(void)
 343 {
 344     static int do_it_once;
 345     if (!do_it_once++) unlink( SOCKETNAME );
 346 }
 347
 348 static void master_socket_destroy( struct object *obj )
 349 {
 350     socket_cleanup();
 351 }
 352
 353 static void request_socket_dump( struct object *obj, int verbose )
 354 {
 355     struct request_socket *sock = (struct request_socket *)obj;
 356     assert( obj->ops == &request_socket_ops );
 357     fprintf( stderr, "Request socket fd=%d thread=%p\n", sock->obj.fd, sock->thread );
 358 }
 359
 360 /* handle a request socket event */
 361 static void request_socket_poll_event( struct object *obj, int event )
 362 {
 363     struct request_socket *sock = (struct request_socket *)obj;
 364     assert( obj->ops == &request_socket_ops );
 365
 366     if (event & (POLLERR | POLLHUP)) kill_thread( sock->thread, 0 );
 367     else if (event & POLLIN)
 368     {
 369         struct thread *thread = sock->thread;
 370         union generic_request req;
 371         int ret;
 372
 373         if ((ret = read( sock->obj.fd, &req, sizeof(req) )) == sizeof(req))
 374         {
 375             call_req_handler( thread, &req );
 376             return;
 377         }
 378         if (!ret)  /* closed pipe */
 379             kill_thread( thread, 0 );
 380         else if (ret > 0)
 381             fatal_protocol_error( thread, "partial read %d\n", ret );
 382         else
 383             fatal_protocol_perror( thread, "read" );
 384     }
 385 }
 386
 387 /* create a request socket and send the fd to the client thread */
 388 struct object *create_request_socket( struct thread *thread )
 389 {
 390     struct request_socket *sock;
 391     int fd[2];
 392
 393     if (pipe( fd )) return NULL;
 394     if (!(sock = alloc_object( &request_socket_ops, fd[0] )))
 395     {
 396         close( fd[1] );
 397         return NULL;
 398     }
 399     sock->thread = thread;
 400     send_client_fd( thread, fd[1], 0 );
 401     close( fd[1] );
 402     fcntl( fd[0], F_SETFL, O_NONBLOCK );
 403     set_select_events( &sock->obj, POLLIN );
 404     return &sock->obj;
 405 }
 406
 407 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 408 const char *get_config_dir(void)
 409 {
 410     static char *confdir;
 411     if (!confdir)
 412     {
 413         const char *prefix = getenv( "WINEPREFIX" );
 414         if (prefix)
 415         {
 416             int len = strlen(prefix);
 417             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 418             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 419         }
 420         else
 421         {
 422             const char *home = getenv( "HOME" );
 423             if (!home)
 424             {
 425                 struct passwd *pwd = getpwuid( getuid() );
 426                 if (!pwd) fatal_error( "could not find your home directory\n" );
 427                 home = pwd->pw_dir;
 428             }
 429             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 430                 fatal_error( "out of memory\n" );
 431             strcpy( confdir, home );
 432             strcat( confdir, CONFDIR );
 433         }
 434         mkdir( confdir, 0755 );  /* just in case */
 435     }
 436     return confdir;
 437 }
 438
 439 /* create the server directory and chdir to it */
 440 static void create_server_dir(void)
 441 {
 442     char hostname[64];
 443     char *serverdir;
 444     const char *confdir = get_config_dir();
 445     struct stat st;
 446
 447     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 448
 449     if (!(serverdir = malloc( strlen(confdir) + strlen(SERVERDIR) + strlen(hostname) + 1 )))
 450         fatal_error( "out of memory\n" );
 451
 452     strcpy( serverdir, confdir );
 453     strcat( serverdir, SERVERDIR );
 454     strcat( serverdir, hostname );
 455
 456     if (chdir( serverdir ) == -1)
 457     {
 458         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 459         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 460         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 461     }
 462     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 463     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 464     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 465     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 466 }
 467
 468 /* open the master server socket and start waiting for new clients */
 469 void open_master_socket(void)
 470 {
 471     struct sockaddr_un addr;
 472     int fd, slen;
 473
 474     /* make sure no request is larger than the maximum size */
 475     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 476
 477     create_server_dir();
 478     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 479     addr.sun_family = AF_UNIX;
 480     strcpy( addr.sun_path, SOCKETNAME );
 481     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 482 #ifdef HAVE_SOCKADDR_SUN_LEN
 483     addr.sun_len = slen;
 484 #endif
 485     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 486     {
 487         if ((errno == EEXIST) || (errno == EADDRINUSE))
 488             exit(0);  /* pretend we succeeded to start */
 489         else
 490             fatal_perror( "bind" );
 491     }
 492     atexit( socket_cleanup );
 493
 494     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 495     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 496
 497     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 498         fatal_error( "out of memory\n" );
 499     set_select_events( &master_socket->obj, POLLIN );
 500
 501     /* setup msghdr structure constant fields */
 502     msghdr.msg_name    = NULL;
 503     msghdr.msg_namelen = 0;
 504     msghdr.msg_iov     = &myiovec;
 505     msghdr.msg_iovlen  = 1;
 506
 507     /* go in the background */
 508     switch(fork())
 509     {
 510     case -1:
 511         fatal_perror( "fork" );
 512     case 0:
 513         setsid();
 514         break;
 515     default:
 516         _exit(0);  /* do not call atexit functions */
 517     }
 518 }
 519
 520 /* close the master socket and stop waiting for new clients */
 521 void close_master_socket(void)
 522 {
 523     /* if a new client is waiting, we keep on running */
 524     if (!check_select_events( master_socket->obj.fd, POLLIN ))
 525         release_object( master_socket );
 526 }
 527
 528 /* lock/unlock the master socket to stop accepting new clients */
 529 void lock_master_socket( int locked )
 530 {
 531     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 532 }