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 /* die on a fatal error */
 133 void fatal_error( const char *err, ... )
 134 {
 135     va_list args;
 136
 137     va_start( args, err );
 138     fprintf( stderr, "wineserver: " );
 139     vfprintf( stderr, err, args );
 140     va_end( args );
 141     exit(1);
 142 }
 143
 144 /* die on a fatal error */
 145 void fatal_perror( const char *err, ... )
 146 {
 147     va_list args;
 148
 149     va_start( args, err );
 150     fprintf( stderr, "wineserver: " );
 151     vfprintf( stderr, err, args );
 152     perror( " " );
 153     va_end( args );
 154     exit(1);
 155 }
 156
 157 /* call a request handler */
 158 static inline void call_req_handler( struct thread *thread )
 159 {
 160     enum request req;
 161     current = thread;
 162     clear_error();
 163
 164     req = ((struct request_header *)current->buffer)->req;
 165
 166     if (debug_level) trace_request( req );
 167
 168     if (req < REQ_NB_REQUESTS)
 169     {
 170         req_handlers[req]( current->buffer );
 171         if (current && !current->wait) send_reply( current );
 172         current = NULL;
 173         return;
 174     }
 175     fatal_protocol_error( current, "bad request %d\n", req );
 176 }
 177
 178 /* send a reply to a thread */
 179 void send_reply( struct thread *thread )
 180 {
 181     assert( !thread->wait );
 182     if (debug_level) trace_reply( thread );
 183     if (!write_request( thread )) set_select_events( &thread->obj, POLLOUT );
 184 }
 185
 186 /* read a message from a client that has something to say */
 187 void read_request( struct thread *thread )
 188 {
 189     int ret;
 190     char dummy[1];
 191
 192 #ifdef HAVE_MSGHDR_ACCRIGHTS
 193     msghdr.msg_accrightslen = sizeof(int);
 194     msghdr.msg_accrights = (void *)&thread->pass_fd;
 195 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 196     msghdr.msg_control    = &cmsg;
 197     msghdr.msg_controllen = sizeof(cmsg);
 198     cmsg.fd = -1;
 199 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 200
 201     assert( thread->pass_fd == -1 );
 202
 203     myiovec.iov_base = dummy;
 204     myiovec.iov_len  = 1;
 205
 206     ret = recvmsg( thread->obj.fd, &msghdr, 0 );
 207 #ifndef HAVE_MSGHDR_ACCRIGHTS
 208     thread->pass_fd = cmsg.fd;
 209 #endif
 210
 211     if (ret > 0)
 212     {
 213         call_req_handler( thread );
 214         thread->pass_fd = -1;
 215         return;
 216     }
 217     if (!ret)  /* closed pipe */
 218     {
 219         kill_thread( thread, 0 );
 220         return;
 221     }
 222     perror("recvmsg");
 223     thread->exit_code = 1;
 224     kill_thread( thread, 1 );
 225 }
 226
 227 /* send a message to a client that is ready to receive something */
 228 int write_request( struct thread *thread )
 229 {
 230     int ret;
 231     struct request_header *header = thread->buffer;
 232
 233     header->error = thread->error;
 234
 235     assert (thread->pass_fd == -1);
 236
 237     ret = write( thread->reply_fd, header, 1 );
 238     if (ret > 0)
 239     {
 240         set_select_events( &thread->obj, POLLIN );
 241         return 1;
 242     }
 243     if (errno == EWOULDBLOCK) return 0;  /* not a fatal error */
 244     if (errno == EPIPE)
 245     {
 246         kill_thread( thread, 0 );  /* normal death */
 247     }
 248     else
 249     {
 250         perror("sendmsg");
 251         thread->exit_code = 1;
 252         kill_thread( thread, 1 );
 253     }
 254     return -1;
 255 }
 256
 257 /* send an fd to a client */
 258 int send_client_fd( struct thread *thread, int fd, int handle )
 259 {
 260     int ret;
 261
 262     if (debug_level)
 263         fprintf( stderr, "%08x: *fd* %d = %d\n", (unsigned int)thread, handle, fd );
 264
 265 #ifdef HAVE_MSGHDR_ACCRIGHTS
 266     msghdr.msg_accrightslen = sizeof(fd);
 267     msghdr.msg_accrights = (void *)&fd;
 268 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 269     msghdr.msg_control    = &cmsg;
 270     msghdr.msg_controllen = sizeof(cmsg);
 271     cmsg.fd = fd;
 272 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 273
 274     myiovec.iov_base = (void *)&handle;
 275     myiovec.iov_len  = sizeof(handle);
 276
 277     ret = sendmsg( thread->obj.fd, &msghdr, 0 );
 278
 279     if (ret > 0) return 0;
 280     if (errno == EPIPE)
 281     {
 282         kill_thread( thread, 0 );  /* normal death */
 283     }
 284     else
 285     {
 286         perror("sendmsg");
 287         thread->exit_code = 1;
 288         kill_thread( thread, 1 );
 289     }
 290     return -1;
 291 }
 292
 293 static void master_socket_dump( struct object *obj, int verbose )
 294 {
 295     struct master_socket *sock = (struct master_socket *)obj;
 296     assert( obj->ops == &master_socket_ops );
 297     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 298 }
 299
 300 /* handle a socket event */
 301 static void master_socket_poll_event( struct object *obj, int event )
 302 {
 303     struct master_socket *sock = (struct master_socket *)obj;
 304     assert( obj->ops == &master_socket_ops );
 305
 306     assert( sock == master_socket );  /* there is only one master socket */
 307
 308     if (event & (POLLERR | POLLHUP))
 309     {
 310         /* this is not supposed to happen */
 311         fprintf( stderr, "wineserver: Error on master socket\n" );
 312         release_object( obj );
 313     }
 314     else if (event & POLLIN)
 315     {
 316         struct sockaddr_un dummy;
 317         int len = sizeof(dummy);
 318         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 319         if (client != -1) create_process( client );
 320     }
 321 }
 322
 323 /* remove the socket upon exit */
 324 static void socket_cleanup(void)
 325 {
 326     static int do_it_once;
 327     if (!do_it_once++) unlink( SOCKETNAME );
 328 }
 329
 330 static void master_socket_destroy( struct object *obj )
 331 {
 332     socket_cleanup();
 333 }
 334
 335 static void request_socket_dump( struct object *obj, int verbose )
 336 {
 337     struct request_socket *sock = (struct request_socket *)obj;
 338     assert( obj->ops == &request_socket_ops );
 339     fprintf( stderr, "Request socket fd=%d thread=%p\n", sock->obj.fd, sock->thread );
 340 }
 341
 342 /* handle a request socket event */
 343 static void request_socket_poll_event( struct object *obj, int event )
 344 {
 345     struct request_socket *sock = (struct request_socket *)obj;
 346     assert( obj->ops == &request_socket_ops );
 347
 348     if (event & (POLLERR | POLLHUP)) kill_thread( sock->thread, 0 );
 349     else if (event & POLLIN)
 350     {
 351         struct thread *thread = sock->thread;
 352         int ret;
 353         char dummy[1];
 354
 355         ret = read( sock->obj.fd, &dummy, 1 );
 356         if (ret > 0)
 357         {
 358             call_req_handler( thread );
 359             return;
 360         }
 361         if (!ret)  /* closed pipe */
 362         {
 363             kill_thread( thread, 0 );
 364             return;
 365         }
 366         perror("read");
 367         thread->exit_code = 1;
 368         kill_thread( thread, 1 );
 369     }
 370 }
 371
 372 /* create a request socket and send the fd to the client thread */
 373 struct object *create_request_socket( struct thread *thread )
 374 {
 375     struct request_socket *sock;
 376     int fd[2];
 377
 378     if (pipe( fd )) return NULL;
 379     if (!(sock = alloc_object( &request_socket_ops, fd[0] )))
 380     {
 381         close( fd[1] );
 382         return NULL;
 383     }
 384     sock->thread = thread;
 385     send_client_fd( thread, fd[1], -1 );
 386     close( fd[1] );
 387     set_select_events( &sock->obj, POLLIN );
 388     return &sock->obj;
 389 }
 390
 391 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 392 const char *get_config_dir(void)
 393 {
 394     static char *confdir;
 395     if (!confdir)
 396     {
 397         const char *prefix = getenv( "WINEPREFIX" );
 398         if (prefix)
 399         {
 400             int len = strlen(prefix);
 401             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 402             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 403         }
 404         else
 405         {
 406             const char *home = getenv( "HOME" );
 407             if (!home)
 408             {
 409                 struct passwd *pwd = getpwuid( getuid() );
 410                 if (!pwd) fatal_error( "could not find your home directory\n" );
 411                 home = pwd->pw_dir;
 412             }
 413             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 414                 fatal_error( "out of memory\n" );
 415             strcpy( confdir, home );
 416             strcat( confdir, CONFDIR );
 417         }
 418         mkdir( confdir, 0755 );  /* just in case */
 419     }
 420     return confdir;
 421 }
 422
 423 /* create the server directory and chdir to it */
 424 static void create_server_dir(void)
 425 {
 426     char hostname[64];
 427     char *serverdir;
 428     const char *confdir = get_config_dir();
 429     struct stat st;
 430
 431     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 432
 433     if (!(serverdir = malloc( strlen(confdir) + strlen(SERVERDIR) + strlen(hostname) + 1 )))
 434         fatal_error( "out of memory\n" );
 435
 436     strcpy( serverdir, confdir );
 437     strcat( serverdir, SERVERDIR );
 438     strcat( serverdir, hostname );
 439
 440     if (chdir( serverdir ) == -1)
 441     {
 442         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 443         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 444         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 445     }
 446     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 447     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 448     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 449     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 450 }
 451
 452 /* open the master server socket and start waiting for new clients */
 453 void open_master_socket(void)
 454 {
 455     struct sockaddr_un addr;
 456     int fd, slen;
 457
 458     /* make sure no request is larger than the maximum size */
 459     assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
 460
 461     create_server_dir();
 462     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 463     addr.sun_family = AF_UNIX;
 464     strcpy( addr.sun_path, SOCKETNAME );
 465     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 466 #ifdef HAVE_SOCKADDR_SUN_LEN
 467     addr.sun_len = slen;
 468 #endif
 469     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 470     {
 471         if ((errno == EEXIST) || (errno == EADDRINUSE))
 472             exit(0);  /* pretend we succeeded to start */
 473         else
 474             fatal_perror( "bind" );
 475     }
 476     atexit( socket_cleanup );
 477
 478     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 479     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 480
 481     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 482         fatal_error( "out of memory\n" );
 483     set_select_events( &master_socket->obj, POLLIN );
 484
 485     /* setup msghdr structure constant fields */
 486     msghdr.msg_name    = NULL;
 487     msghdr.msg_namelen = 0;
 488     msghdr.msg_iov     = &myiovec;
 489     msghdr.msg_iovlen  = 1;
 490
 491     /* go in the background */
 492     switch(fork())
 493     {
 494     case -1:
 495         fatal_perror( "fork" );
 496     case 0:
 497         setsid();
 498         break;
 499     default:
 500         _exit(0);  /* do not call atexit functions */
 501     }
 502 }
 503
 504 /* close the master socket and stop waiting for new clients */
 505 void close_master_socket(void)
 506 {
 507     /* if a new client is waiting, we keep on running */
 508     if (!check_select_events( master_socket->obj.fd, POLLIN ))
 509         release_object( master_socket );
 510 }
 511
 512 /* lock/unlock the master socket to stop accepting new clients */
 513 void lock_master_socket( int locked )
 514 {
 515     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 516 }