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 thread *current = NULL;  /* thread handling the current request */
  75 unsigned int global_error = 0;  /* global error code for when no thread is current */
  76
  77 static struct master_socket *master_socket;  /* the master socket object */
  78
  79 /* socket communication static structures */
  80 static struct iovec myiovec;
  81 static struct msghdr msghdr;
  82 #ifndef HAVE_MSGHDR_ACCRIGHTS
  83 struct cmsg_fd
  84 {
  85     int len;   /* sizeof structure */
  86     int level; /* SOL_SOCKET */
  87     int type;  /* SCM_RIGHTS */
  88     int fd;    /* fd to pass */
  89 };
  90 static struct cmsg_fd cmsg = { sizeof(cmsg), SOL_SOCKET, SCM_RIGHTS, -1 };
  91 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
  92
  93 /* complain about a protocol error and terminate the client connection */
  94 void fatal_protocol_error( struct thread *thread, const char *err, ... )
  95 {
  96     va_list args;
  97
  98     va_start( args, err );
  99     fprintf( stderr, "Protocol error:%p: ", thread );
 100     vfprintf( stderr, err, args );
 101     va_end( args );
 102     thread->exit_code = 1;
 103     kill_thread( thread, 1 );
 104 }
 105
 106 /* complain about a protocol error and terminate the client connection */
 107 void fatal_protocol_perror( struct thread *thread, const char *err, ... )
 108 {
 109     va_list args;
 110
 111     va_start( args, err );
 112     fprintf( stderr, "Protocol error:%p: ", thread );
 113     vfprintf( stderr, err, args );
 114     perror( " " );
 115     va_end( args );
 116     thread->exit_code = 1;
 117     kill_thread( thread, 1 );
 118 }
 119
 120 /* die on a fatal error */
 121 void fatal_error( const char *err, ... )
 122 {
 123     va_list args;
 124
 125     va_start( args, err );
 126     fprintf( stderr, "wineserver: " );
 127     vfprintf( stderr, err, args );
 128     va_end( args );
 129     exit(1);
 130 }
 131
 132 /* die on a fatal error */
 133 void fatal_perror( const char *err, ... )
 134 {
 135     va_list args;
 136
 137     va_start( args, err );
 138     fprintf( stderr, "wineserver: " );
 139     vfprintf( stderr, err, args );
 140     perror( " " );
 141     va_end( args );
 142     exit(1);
 143 }
 144
 145 /* call a request handler */
 146 static inline void call_req_handler( struct thread *thread, union generic_request *request )
 147 {
 148     enum request req = request->header.req;
 149
 150     current = thread;
 151     clear_error();
 152
 153     if (debug_level) trace_request( thread, request );
 154
 155     if (request->header.var_size)
 156     {
 157         if ((unsigned int)request->header.var_offset +
 158                           request->header.var_size > MAX_REQUEST_LENGTH)
 159         {
 160             fatal_protocol_error( current, "bad request offset/size %d/%d\n",
 161                                   request->header.var_offset, request->header.var_size );
 162             return;
 163         }
 164     }
 165
 166     if (req < REQ_NB_REQUESTS)
 167     {
 168         req_handlers[req]( request );
 169         if (current) send_reply( current, request );
 170         current = NULL;
 171         return;
 172     }
 173     fatal_protocol_error( current, "bad request %d\n", req );
 174 }
 175
 176 /* read a request from a thread */
 177 void read_request( struct thread *thread )
 178 {
 179     union generic_request req;
 180     int ret;
 181
 182     if ((ret = read( thread->obj.fd, &req, sizeof(req) )) == sizeof(req))
 183     {
 184         call_req_handler( thread, &req );
 185         return;
 186     }
 187     if (!ret)  /* closed pipe */
 188         kill_thread( thread, 0 );
 189     else if (ret > 0)
 190         fatal_protocol_error( thread, "partial read %d\n", ret );
 191     else
 192         fatal_protocol_perror( thread, "read" );
 193 }
 194
 195 /* send a reply to a thread */
 196 void send_reply( struct thread *thread, union generic_request *request )
 197 {
 198     int ret;
 199
 200     if (debug_level) trace_reply( thread, request );
 201
 202     request->header.error = thread->error;
 203
 204     if ((ret = write( thread->reply_fd, request, sizeof(*request) )) != sizeof(*request))
 205     {
 206         if (ret >= 0)
 207             fatal_protocol_error( thread, "partial write %d\n", ret );
 208         else if (errno == EPIPE)
 209             kill_thread( thread, 0 );  /* normal death */
 210         else
 211             fatal_protocol_perror( thread, "reply write" );
 212     }
 213 }
 214
 215 /* receive a file descriptor on the process socket */
 216 int receive_fd( struct process *process )
 217 {
 218     struct send_fd data;
 219     int fd, ret;
 220
 221 #ifdef HAVE_MSGHDR_ACCRIGHTS
 222     msghdr.msg_accrightslen = sizeof(int);
 223     msghdr.msg_accrights = (void *)&fd;
 224 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 225     msghdr.msg_control    = &cmsg;
 226     msghdr.msg_controllen = sizeof(cmsg);
 227     cmsg.fd = -1;
 228 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 229
 230     myiovec.iov_base = &data;
 231     myiovec.iov_len  = sizeof(data);
 232
 233     ret = recvmsg( process->obj.fd, &msghdr, 0 );
 234 #ifndef HAVE_MSGHDR_ACCRIGHTS
 235     fd = cmsg.fd;
 236 #endif
 237
 238     if (ret == sizeof(data))
 239     {
 240         struct thread *thread;
 241
 242         if (data.tid) thread = get_thread_from_id( data.tid );
 243         else thread = (struct thread *)grab_object( process->thread_list );
 244
 245         if (!thread || thread->process != process)
 246         {
 247             if (debug_level)
 248                 fprintf( stderr, "%08x: *fd* %d <- %d bad thread id\n",
 249                          (unsigned int)data.tid, data.fd, fd );
 250             close( fd );
 251         }
 252         else
 253         {
 254             if (debug_level)
 255                 fprintf( stderr, "%08x: *fd* %d <- %d\n",
 256                          (unsigned int)thread, data.fd, fd );
 257             thread_add_inflight_fd( thread, data.fd, fd );
 258         }
 259         if (thread) release_object( thread );
 260         return 0;
 261     }
 262
 263     if (ret >= 0)
 264     {
 265         if (ret > 0)
 266             fprintf( stderr, "Protocol error: process %p: partial recvmsg %d for fd\n",
 267                      process, ret );
 268         kill_process( process, NULL, 1 );
 269     }
 270     else
 271     {
 272         if (errno != EWOULDBLOCK && errno != EAGAIN)
 273         {
 274             fprintf( stderr, "Protocol error: process %p: ", process );
 275             perror( "recvmsg" );
 276             kill_process( process, NULL, 1 );
 277         }
 278     }
 279     return -1;
 280 }
 281
 282 /* send an fd to a client */
 283 int send_client_fd( struct process *process, int fd, handle_t handle )
 284 {
 285     int ret;
 286
 287     if (debug_level)
 288         fprintf( stderr, "%08x: *fd* %d -> %d\n", (unsigned int)current, handle, fd );
 289
 290 #ifdef HAVE_MSGHDR_ACCRIGHTS
 291     msghdr.msg_accrightslen = sizeof(fd);
 292     msghdr.msg_accrights = (void *)&fd;
 293 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 294     msghdr.msg_control    = &cmsg;
 295     msghdr.msg_controllen = sizeof(cmsg);
 296     cmsg.fd = fd;
 297 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 298
 299     myiovec.iov_base = (void *)&handle;
 300     myiovec.iov_len  = sizeof(handle);
 301
 302     ret = sendmsg( process->obj.fd, &msghdr, 0 );
 303
 304     if (ret == sizeof(handle)) return 0;
 305
 306     if (ret >= 0)
 307     {
 308         if (ret > 0)
 309             fprintf( stderr, "Protocol error: process %p: partial sendmsg %d\n", process, ret );
 310         kill_process( process, NULL, 1 );
 311     }
 312     else
 313     {
 314         fprintf( stderr, "Protocol error: process %p: ", process );
 315         perror( "sendmsg" );
 316         kill_process( process, NULL, 1 );
 317     }
 318     return -1;
 319 }
 320
 321 static void master_socket_dump( struct object *obj, int verbose )
 322 {
 323     struct master_socket *sock = (struct master_socket *)obj;
 324     assert( obj->ops == &master_socket_ops );
 325     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 326 }
 327
 328 /* handle a socket event */
 329 static void master_socket_poll_event( struct object *obj, int event )
 330 {
 331     struct master_socket *sock = (struct master_socket *)obj;
 332     assert( obj->ops == &master_socket_ops );
 333
 334     assert( sock == master_socket );  /* there is only one master socket */
 335
 336     if (event & (POLLERR | POLLHUP))
 337     {
 338         /* this is not supposed to happen */
 339         fprintf( stderr, "wineserver: Error on master socket\n" );
 340         release_object( obj );
 341     }
 342     else if (event & POLLIN)
 343     {
 344         struct sockaddr_un dummy;
 345         int len = sizeof(dummy);
 346         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 347         if (client == -1) return;
 348         fcntl( client, F_SETFL, O_NONBLOCK );
 349         create_process( client );
 350     }
 351 }
 352
 353 /* remove the socket upon exit */
 354 static void socket_cleanup(void)
 355 {
 356     static int do_it_once;
 357     if (!do_it_once++) unlink( SOCKETNAME );
 358 }
 359
 360 static void master_socket_destroy( struct object *obj )
 361 {
 362     socket_cleanup();
 363 }
 364
 365 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 366 const char *get_config_dir(void)
 367 {
 368     static char *confdir;
 369     if (!confdir)
 370     {
 371         const char *prefix = getenv( "WINEPREFIX" );
 372         if (prefix)
 373         {
 374             int len = strlen(prefix);
 375             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 376             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 377         }
 378         else
 379         {
 380             const char *home = getenv( "HOME" );
 381             if (!home)
 382             {
 383                 struct passwd *pwd = getpwuid( getuid() );
 384                 if (!pwd) fatal_error( "could not find your home directory\n" );
 385                 home = pwd->pw_dir;
 386             }
 387             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 388                 fatal_error( "out of memory\n" );
 389             strcpy( confdir, home );
 390             strcat( confdir, CONFDIR );
 391         }
 392         mkdir( confdir, 0755 );  /* just in case */
 393     }
 394     return confdir;
 395 }
 396
 397 /* create the server directory and chdir to it */
 398 static void create_server_dir(void)
 399 {
 400     char hostname[64];
 401     char *serverdir;
 402     const char *confdir = get_config_dir();
 403     struct stat st;
 404
 405     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 406
 407     if (!(serverdir = malloc( strlen(confdir) + strlen(SERVERDIR) + strlen(hostname) + 1 )))
 408         fatal_error( "out of memory\n" );
 409
 410     strcpy( serverdir, confdir );
 411     strcat( serverdir, SERVERDIR );
 412     strcat( serverdir, hostname );
 413
 414     if (chdir( serverdir ) == -1)
 415     {
 416         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 417         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 418         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 419     }
 420     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 421     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 422     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 423     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 424 }
 425
 426 /* open the master server socket and start waiting for new clients */
 427 void open_master_socket(void)
 428 {
 429     struct sockaddr_un addr;
 430     int fd, slen;
 431
 432     /* make sure no request is larger than the maximum size */
 433     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 434
 435     create_server_dir();
 436     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 437     addr.sun_family = AF_UNIX;
 438     strcpy( addr.sun_path, SOCKETNAME );
 439     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 440 #ifdef HAVE_SOCKADDR_SUN_LEN
 441     addr.sun_len = slen;
 442 #endif
 443     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 444     {
 445         if ((errno == EEXIST) || (errno == EADDRINUSE))
 446             exit(0);  /* pretend we succeeded to start */
 447         else
 448             fatal_perror( "bind" );
 449     }
 450     atexit( socket_cleanup );
 451
 452     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 453     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 454
 455     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 456         fatal_error( "out of memory\n" );
 457     set_select_events( &master_socket->obj, POLLIN );
 458
 459     /* setup msghdr structure constant fields */
 460     msghdr.msg_name    = NULL;
 461     msghdr.msg_namelen = 0;
 462     msghdr.msg_iov     = &myiovec;
 463     msghdr.msg_iovlen  = 1;
 464
 465     /* go in the background */
 466     switch(fork())
 467     {
 468     case -1:
 469         fatal_perror( "fork" );
 470     case 0:
 471         setsid();
 472         break;
 473     default:
 474         _exit(0);  /* do not call atexit functions */
 475     }
 476 }
 477
 478 /* close the master socket and stop waiting for new clients */
 479 void close_master_socket(void)
 480 {
 481     /* if a new client is waiting, we keep on running */
 482     if (!check_select_events( master_socket->obj.fd, POLLIN ))
 483         release_object( master_socket );
 484 }
 485
 486 /* lock/unlock the master socket to stop accepting new clients */
 487 void lock_master_socket( int locked )
 488 {
 489     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 490 }