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         fprintf( stderr, "Protocol error: process %p: partial recvmsg %d for fd\n", process, ret );
 266         kill_process( process, NULL, 1 );
 267     }
 268     else
 269     {
 270         if (errno != EWOULDBLOCK && errno != EAGAIN)
 271         {
 272             fprintf( stderr, "Protocol error: process %p: ", process );
 273             perror( "recvmsg" );
 274             kill_process( process, NULL, 1 );
 275         }
 276     }
 277     return -1;
 278 }
 279
 280 /* send an fd to a client */
 281 int send_client_fd( struct process *process, int fd, handle_t handle )
 282 {
 283     int ret;
 284
 285     if (debug_level)
 286         fprintf( stderr, "%08x: *fd* %d -> %d\n", (unsigned int)current, handle, fd );
 287
 288 #ifdef HAVE_MSGHDR_ACCRIGHTS
 289     msghdr.msg_accrightslen = sizeof(fd);
 290     msghdr.msg_accrights = (void *)&fd;
 291 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 292     msghdr.msg_control    = &cmsg;
 293     msghdr.msg_controllen = sizeof(cmsg);
 294     cmsg.fd = fd;
 295 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 296
 297     myiovec.iov_base = (void *)&handle;
 298     myiovec.iov_len  = sizeof(handle);
 299
 300     ret = sendmsg( process->obj.fd, &msghdr, 0 );
 301
 302     if (ret == sizeof(handle)) return 0;
 303
 304     if (ret >= 0)
 305     {
 306         fprintf( stderr, "Protocol error: process %p: partial sendmsg %d\n", process, ret );
 307         kill_process( process, NULL, 1 );
 308     }
 309     else
 310     {
 311         fprintf( stderr, "Protocol error: process %p: ", process );
 312         perror( "sendmsg" );
 313         kill_process( process, NULL, 1 );
 314     }
 315     return -1;
 316 }
 317
 318 static void master_socket_dump( struct object *obj, int verbose )
 319 {
 320     struct master_socket *sock = (struct master_socket *)obj;
 321     assert( obj->ops == &master_socket_ops );
 322     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 323 }
 324
 325 /* handle a socket event */
 326 static void master_socket_poll_event( struct object *obj, int event )
 327 {
 328     struct master_socket *sock = (struct master_socket *)obj;
 329     assert( obj->ops == &master_socket_ops );
 330
 331     assert( sock == master_socket );  /* there is only one master socket */
 332
 333     if (event & (POLLERR | POLLHUP))
 334     {
 335         /* this is not supposed to happen */
 336         fprintf( stderr, "wineserver: Error on master socket\n" );
 337         release_object( obj );
 338     }
 339     else if (event & POLLIN)
 340     {
 341         struct sockaddr_un dummy;
 342         int len = sizeof(dummy);
 343         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 344         if (client != -1) create_process( client );
 345     }
 346 }
 347
 348 /* remove the socket upon exit */
 349 static void socket_cleanup(void)
 350 {
 351     static int do_it_once;
 352     if (!do_it_once++) unlink( SOCKETNAME );
 353 }
 354
 355 static void master_socket_destroy( struct object *obj )
 356 {
 357     socket_cleanup();
 358 }
 359
 360 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 361 const char *get_config_dir(void)
 362 {
 363     static char *confdir;
 364     if (!confdir)
 365     {
 366         const char *prefix = getenv( "WINEPREFIX" );
 367         if (prefix)
 368         {
 369             int len = strlen(prefix);
 370             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 371             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 372         }
 373         else
 374         {
 375             const char *home = getenv( "HOME" );
 376             if (!home)
 377             {
 378                 struct passwd *pwd = getpwuid( getuid() );
 379                 if (!pwd) fatal_error( "could not find your home directory\n" );
 380                 home = pwd->pw_dir;
 381             }
 382             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 383                 fatal_error( "out of memory\n" );
 384             strcpy( confdir, home );
 385             strcat( confdir, CONFDIR );
 386         }
 387         mkdir( confdir, 0755 );  /* just in case */
 388     }
 389     return confdir;
 390 }
 391
 392 /* create the server directory and chdir to it */
 393 static void create_server_dir(void)
 394 {
 395     char hostname[64];
 396     char *serverdir;
 397     const char *confdir = get_config_dir();
 398     struct stat st;
 399
 400     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 401
 402     if (!(serverdir = malloc( strlen(confdir) + strlen(SERVERDIR) + strlen(hostname) + 1 )))
 403         fatal_error( "out of memory\n" );
 404
 405     strcpy( serverdir, confdir );
 406     strcat( serverdir, SERVERDIR );
 407     strcat( serverdir, hostname );
 408
 409     if (chdir( serverdir ) == -1)
 410     {
 411         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 412         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 413         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 414     }
 415     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 416     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 417     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 418     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 419 }
 420
 421 /* open the master server socket and start waiting for new clients */
 422 void open_master_socket(void)
 423 {
 424     struct sockaddr_un addr;
 425     int fd, slen;
 426
 427     /* make sure no request is larger than the maximum size */
 428     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 429
 430     create_server_dir();
 431     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 432     addr.sun_family = AF_UNIX;
 433     strcpy( addr.sun_path, SOCKETNAME );
 434     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 435 #ifdef HAVE_SOCKADDR_SUN_LEN
 436     addr.sun_len = slen;
 437 #endif
 438     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 439     {
 440         if ((errno == EEXIST) || (errno == EADDRINUSE))
 441             exit(0);  /* pretend we succeeded to start */
 442         else
 443             fatal_perror( "bind" );
 444     }
 445     atexit( socket_cleanup );
 446
 447     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 448     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 449
 450     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 451         fatal_error( "out of memory\n" );
 452     set_select_events( &master_socket->obj, POLLIN );
 453
 454     /* setup msghdr structure constant fields */
 455     msghdr.msg_name    = NULL;
 456     msghdr.msg_namelen = 0;
 457     msghdr.msg_iov     = &myiovec;
 458     msghdr.msg_iovlen  = 1;
 459
 460     /* go in the background */
 461     switch(fork())
 462     {
 463     case -1:
 464         fatal_perror( "fork" );
 465     case 0:
 466         setsid();
 467         break;
 468     default:
 469         _exit(0);  /* do not call atexit functions */
 470     }
 471 }
 472
 473 /* close the master socket and stop waiting for new clients */
 474 void close_master_socket(void)
 475 {
 476     /* if a new client is waiting, we keep on running */
 477     if (!check_select_events( master_socket->obj.fd, POLLIN ))
 478         release_object( master_socket );
 479 }
 480
 481 /* lock/unlock the master socket to stop accepting new clients */
 482 void lock_master_socket( int locked )
 483 {
 484     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 485 }