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
  37 /* Some versions of glibc don't define this */
  38 #ifndef SCM_RIGHTS
  39 #define SCM_RIGHTS 1
  40 #endif
  41
  42  /* path names for server master Unix socket */
  43 #define CONFDIR    "/.wine"        /* directory for Wine config relative to $HOME */
  44 #define SERVERDIR  "/wineserver-"  /* server socket directory (hostname appended) */
  45 #define SOCKETNAME "socket"        /* name of the socket file */
  46
  47 struct master_socket
  48 {
  49     struct object       obj;         /* object header */
  50 };
  51
  52 static void master_socket_dump( struct object *obj, int verbose );
  53 static void master_socket_poll_event( struct object *obj, int event );
  54 static void master_socket_destroy( struct object *obj );
  55
  56 static const struct object_ops master_socket_ops =
  57 {
  58     sizeof(struct master_socket),  /* size */
  59     master_socket_dump,            /* dump */
  60     no_add_queue,                  /* add_queue */
  61     NULL,                          /* remove_queue */
  62     NULL,                          /* signaled */
  63     NULL,                          /* satisfied */
  64     NULL,                          /* get_poll_events */
  65     master_socket_poll_event,      /* poll_event */
  66     no_read_fd,                    /* get_read_fd */
  67     no_write_fd,                   /* get_write_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
  76 static struct master_socket *master_socket;  /* the master socket object */
  77
  78 /* socket communication static structures */
  79 static struct iovec myiovec;
  80 static struct msghdr msghdr = { NULL, 0, &myiovec, 1, };
  81 #ifndef HAVE_MSGHDR_ACCRIGHTS
  82 struct cmsg_fd
  83 {
  84     int len;   /* sizeof structure */
  85     int level; /* SOL_SOCKET */
  86     int type;  /* SCM_RIGHTS */
  87     int fd;    /* fd to pass */
  88 };
  89 static struct cmsg_fd cmsg = { sizeof(cmsg), SOL_SOCKET, SCM_RIGHTS, -1 };
  90 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
  91
  92 /* complain about a protocol error and terminate the client connection */
  93 void fatal_protocol_error( struct thread *thread, const char *err, ... )
  94 {
  95     va_list args;
  96
  97     va_start( args, err );
  98     fprintf( stderr, "Protocol error:%p: ", thread );
  99     vfprintf( stderr, err, args );
 100     va_end( args );
 101     thread->exit_code = 1;
 102     kill_thread( thread, 1 );
 103 }
 104
 105 /* die on a fatal error */
 106 static void fatal_error( const char *err, ... )
 107 {
 108     va_list args;
 109
 110     va_start( args, err );
 111     fprintf( stderr, "wineserver: " );
 112     vfprintf( stderr, err, args );
 113     va_end( args );
 114     exit(1);
 115 }
 116
 117 /* die on a fatal error */
 118 static void fatal_perror( const char *err, ... )
 119 {
 120     va_list args;
 121
 122     va_start( args, err );
 123     fprintf( stderr, "wineserver: " );
 124     vfprintf( stderr, err, args );
 125     perror( " " );
 126     va_end( args );
 127     exit(1);
 128 }
 129
 130 /* call a request handler */
 131 static inline void call_req_handler( struct thread *thread, enum request req )
 132 {
 133     current = thread;
 134     clear_error();
 135
 136     if (debug_level) trace_request( req );
 137
 138     if (req < REQ_NB_REQUESTS)
 139     {
 140         req_handlers[req]( current->buffer );
 141         if (current && !current->wait) send_reply( current );
 142         current = NULL;
 143         return;
 144     }
 145     fatal_protocol_error( current, "bad request %d\n", req );
 146 }
 147
 148 /* set the fd to pass to the thread */
 149 void set_reply_fd( struct thread *thread, int pass_fd )
 150 {
 151     assert( thread->pass_fd == -1 );
 152     thread->pass_fd = pass_fd;
 153 }
 154
 155 /* send a reply to a thread */
 156 void send_reply( struct thread *thread )
 157 {
 158     assert( !thread->wait );
 159     if (debug_level) trace_reply( thread );
 160     if (!write_request( thread )) set_select_events( &thread->obj, POLLOUT );
 161 }
 162
 163 /* read a message from a client that has something to say */
 164 void read_request( struct thread *thread )
 165 {
 166     int ret;
 167     enum request req;
 168
 169 #ifdef HAVE_MSGHDR_ACCRIGHTS
 170     msghdr.msg_accrightslen = sizeof(int);
 171     msghdr.msg_accrights = (void *)&thread->pass_fd;
 172 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 173     msghdr.msg_control    = &cmsg;
 174     msghdr.msg_controllen = sizeof(cmsg);
 175     cmsg.fd = -1;
 176 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 177
 178     assert( thread->pass_fd == -1 );
 179
 180     myiovec.iov_base = (void *)&req;
 181     myiovec.iov_len  = sizeof(req);
 182
 183     ret = recvmsg( thread->obj.fd, &msghdr, 0 );
 184 #ifndef HAVE_MSGHDR_ACCRIGHTS
 185     thread->pass_fd = cmsg.fd;
 186 #endif
 187
 188     if (ret == sizeof(req))
 189     {
 190         call_req_handler( thread, req );
 191         thread->pass_fd = -1;
 192         return;
 193     }
 194     if (ret == -1)
 195     {
 196         perror("recvmsg");
 197         thread->exit_code = 1;
 198         kill_thread( thread, 1 );
 199         return;
 200     }
 201     if (!ret)  /* closed pipe */
 202     {
 203         kill_thread( thread, 0 );
 204         return;
 205     }
 206     fatal_protocol_error( thread, "partial message received %d/%d\n", ret, sizeof(req) );
 207 }
 208
 209 /* send a message to a client that is ready to receive something */
 210 int write_request( struct thread *thread )
 211 {
 212     int ret;
 213
 214     if (thread->pass_fd == -1)
 215     {
 216         ret = write( thread->obj.fd, &thread->error, sizeof(thread->error) );
 217     }
 218     else  /* we have an fd to send */
 219     {
 220 #ifdef HAVE_MSGHDR_ACCRIGHTS
 221         msghdr.msg_accrightslen = sizeof(int);
 222         msghdr.msg_accrights = (void *)&thread->pass_fd;
 223 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 224         msghdr.msg_control    = &cmsg;
 225         msghdr.msg_controllen = sizeof(cmsg);
 226         cmsg.fd = thread->pass_fd;
 227 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 228
 229         myiovec.iov_base = (void *)&thread->error;
 230         myiovec.iov_len  = sizeof(thread->error);
 231
 232         ret = sendmsg( thread->obj.fd, &msghdr, 0 );
 233         close( thread->pass_fd );
 234         thread->pass_fd = -1;
 235     }
 236     if (ret == sizeof(thread->error))
 237     {
 238         set_select_events( &thread->obj, POLLIN );
 239         return 1;
 240     }
 241     if (ret == -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     }
 255     else
 256     {
 257         thread->exit_code = 1;
 258         kill_thread( thread, 1 );
 259         fprintf( stderr, "Partial message sent %d/%d\n", ret, sizeof(thread->error) );
 260     }
 261     return -1;
 262 }
 263
 264 static void master_socket_dump( struct object *obj, int verbose )
 265 {
 266     struct master_socket *sock = (struct master_socket *)obj;
 267     assert( obj->ops == &master_socket_ops );
 268     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 269 }
 270
 271 /* handle a socket event */
 272 static void master_socket_poll_event( struct object *obj, int event )
 273 {
 274     struct master_socket *sock = (struct master_socket *)obj;
 275     assert( obj->ops == &master_socket_ops );
 276
 277     assert( sock == master_socket );  /* there is only one master socket */
 278
 279     if (event & (POLLERR | POLLHUP))
 280     {
 281         /* this is not supposed to happen */
 282         fprintf( stderr, "wineserver: Error on master socket\n" );
 283         release_object( obj );
 284     }
 285     else if (event & POLLIN)
 286     {
 287         struct sockaddr_un dummy;
 288         int len = sizeof(dummy);
 289         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 290         if (client != -1) create_process( client, NULL, NULL, "", 1 );
 291     }
 292 }
 293
 294 /* remove the socket upon exit */
 295 static void socket_cleanup(void)
 296 {
 297     unlink( SOCKETNAME );
 298 }
 299
 300 static void master_socket_destroy( struct object *obj )
 301 {
 302     socket_cleanup();
 303 }
 304
 305 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 306 static const char *get_config_dir(void)
 307 {
 308     static char *confdir;
 309     if (!confdir)
 310     {
 311         const char *prefix = getenv( "WINEPREFIX" );
 312         if (prefix)
 313         {
 314             int len = strlen(prefix);
 315             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 316             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 317         }
 318         else
 319         {
 320             const char *home = getenv( "HOME" );
 321             if (!home)
 322             {
 323                 struct passwd *pwd = getpwuid( getuid() );
 324                 if (!pwd) fatal_error( "could not find your home directory\n" );
 325                 home = pwd->pw_dir;
 326             }
 327             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 328                 fatal_error( "out of memory\n" );
 329             strcpy( confdir, home );
 330             strcat( confdir, CONFDIR );
 331         }
 332         mkdir( confdir, 0755 );  /* just in case */
 333     }
 334     return confdir;
 335 }
 336
 337 /* create the server directory and chdir to it */
 338 static void create_server_dir(void)
 339 {
 340     char hostname[64];
 341     char *serverdir;
 342     const char *confdir = get_config_dir();
 343     struct stat st;
 344
 345     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 346
 347     if (!(serverdir = malloc( strlen(confdir) + strlen(SERVERDIR) + strlen(hostname) + 1 )))
 348         fatal_error( "out of memory\n" );
 349
 350     strcpy( serverdir, confdir );
 351     strcat( serverdir, SERVERDIR );
 352     strcat( serverdir, hostname );
 353
 354     if (chdir( serverdir ) == -1)
 355     {
 356         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 357         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 358         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 359     }
 360     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 361     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 362     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 363     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 364 }
 365
 366 /* open the master server socket and start waiting for new clients */
 367 void open_master_socket(void)
 368 {
 369     struct sockaddr_un addr;
 370     int fd, slen;
 371
 372     create_server_dir();
 373     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 374     addr.sun_family = AF_UNIX;
 375     strcpy( addr.sun_path, SOCKETNAME );
 376     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 377 #ifdef HAVE_SOCKADDR_SUN_LEN
 378     addr.sun_len = slen;
 379 #endif
 380     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 381     {
 382         if ((errno == EEXIST) || (errno == EADDRINUSE))
 383             fatal_error( "another server is already running\n" );
 384         else
 385             fatal_perror( "bind" );
 386     }
 387     atexit( socket_cleanup );
 388
 389     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 390     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 391
 392     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 393         fatal_error( "out of memory\n" );
 394     set_select_events( &master_socket->obj, POLLIN );
 395 }
 396
 397 /* close the master socket and stop waiting for new clients */
 398 void close_master_socket(void)
 399 {
 400     release_object( master_socket );
 401 }
 402
 403 /* lock/unlock the master socket to stop accepting new clients */
 404 void lock_master_socket( int locked )
 405 {
 406     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 407 }