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, ... ) WINE_NORETURN;
 107 static void fatal_error( const char *err, ... )
 108 {
 109     va_list args;
 110
 111     va_start( args, err );
 112     fprintf( stderr, "wineserver: " );
 113     vfprintf( stderr, err, args );
 114     va_end( args );
 115     exit(1);
 116 }
 117
 118 /* die on a fatal error */
 119 static void fatal_perror( const char *err, ... ) WINE_NORETURN;
 120 static void fatal_perror( const char *err, ... )
 121 {
 122     va_list args;
 123
 124     va_start( args, err );
 125     fprintf( stderr, "wineserver: " );
 126     vfprintf( stderr, err, args );
 127     perror( " " );
 128     va_end( args );
 129     exit(1);
 130 }
 131
 132 /* call a request handler */
 133 static inline void call_req_handler( struct thread *thread, enum request req )
 134 {
 135     current = thread;
 136     clear_error();
 137
 138     if (debug_level) trace_request( req );
 139
 140     if (req < REQ_NB_REQUESTS)
 141     {
 142         req_handlers[req]( current->buffer );
 143         if (current && !current->wait) send_reply( current );
 144         current = NULL;
 145         return;
 146     }
 147     fatal_protocol_error( current, "bad request %d\n", req );
 148 }
 149
 150 /* set the fd to pass to the thread */
 151 void set_reply_fd( struct thread *thread, int pass_fd )
 152 {
 153     assert( thread->pass_fd == -1 );
 154     thread->pass_fd = pass_fd;
 155 }
 156
 157 /* send a reply to a thread */
 158 void send_reply( struct thread *thread )
 159 {
 160     assert( !thread->wait );
 161     if (debug_level) trace_reply( thread );
 162     if (!write_request( thread )) set_select_events( &thread->obj, POLLOUT );
 163 }
 164
 165 /* read a message from a client that has something to say */
 166 void read_request( struct thread *thread )
 167 {
 168     int ret;
 169     enum request req;
 170
 171 #ifdef HAVE_MSGHDR_ACCRIGHTS
 172     msghdr.msg_accrightslen = sizeof(int);
 173     msghdr.msg_accrights = (void *)&thread->pass_fd;
 174 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 175     msghdr.msg_control    = &cmsg;
 176     msghdr.msg_controllen = sizeof(cmsg);
 177     cmsg.fd = -1;
 178 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 179
 180     assert( thread->pass_fd == -1 );
 181
 182     myiovec.iov_base = (void *)&req;
 183     myiovec.iov_len  = sizeof(req);
 184
 185     ret = recvmsg( thread->obj.fd, &msghdr, 0 );
 186 #ifndef HAVE_MSGHDR_ACCRIGHTS
 187     thread->pass_fd = cmsg.fd;
 188 #endif
 189
 190     if (ret == sizeof(req))
 191     {
 192         call_req_handler( thread, req );
 193         thread->pass_fd = -1;
 194         return;
 195     }
 196     if (ret == -1)
 197     {
 198         perror("recvmsg");
 199         thread->exit_code = 1;
 200         kill_thread( thread, 1 );
 201         return;
 202     }
 203     if (!ret)  /* closed pipe */
 204     {
 205         kill_thread( thread, 0 );
 206         return;
 207     }
 208     fatal_protocol_error( thread, "partial message received %d/%d\n", ret, sizeof(req) );
 209 }
 210
 211 /* send a message to a client that is ready to receive something */
 212 int write_request( struct thread *thread )
 213 {
 214     int ret;
 215
 216     if (thread->pass_fd == -1)
 217     {
 218         ret = write( thread->obj.fd, &thread->error, sizeof(thread->error) );
 219     }
 220     else  /* we have an fd to send */
 221     {
 222 #ifdef HAVE_MSGHDR_ACCRIGHTS
 223         msghdr.msg_accrightslen = sizeof(int);
 224         msghdr.msg_accrights = (void *)&thread->pass_fd;
 225 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 226         msghdr.msg_control    = &cmsg;
 227         msghdr.msg_controllen = sizeof(cmsg);
 228         cmsg.fd = thread->pass_fd;
 229 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 230
 231         myiovec.iov_base = (void *)&thread->error;
 232         myiovec.iov_len  = sizeof(thread->error);
 233
 234         ret = sendmsg( thread->obj.fd, &msghdr, 0 );
 235         close( thread->pass_fd );
 236         thread->pass_fd = -1;
 237     }
 238     if (ret == sizeof(thread->error))
 239     {
 240         set_select_events( &thread->obj, POLLIN );
 241         return 1;
 242     }
 243     if (ret == -1)
 244     {
 245         if (errno == EWOULDBLOCK) return 0;  /* not a fatal error */
 246         if (errno == EPIPE)
 247         {
 248             kill_thread( thread, 0 );  /* normal death */
 249         }
 250         else
 251         {
 252             perror("sendmsg");
 253             thread->exit_code = 1;
 254             kill_thread( thread, 1 );
 255         }
 256     }
 257     else
 258     {
 259         thread->exit_code = 1;
 260         kill_thread( thread, 1 );
 261         fprintf( stderr, "Partial message sent %d/%d\n", ret, sizeof(thread->error) );
 262     }
 263     return -1;
 264 }
 265
 266 static void master_socket_dump( struct object *obj, int verbose )
 267 {
 268     struct master_socket *sock = (struct master_socket *)obj;
 269     assert( obj->ops == &master_socket_ops );
 270     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 271 }
 272
 273 /* handle a socket event */
 274 static void master_socket_poll_event( struct object *obj, int event )
 275 {
 276     struct master_socket *sock = (struct master_socket *)obj;
 277     assert( obj->ops == &master_socket_ops );
 278
 279     assert( sock == master_socket );  /* there is only one master socket */
 280
 281     if (event & (POLLERR | POLLHUP))
 282     {
 283         /* this is not supposed to happen */
 284         fprintf( stderr, "wineserver: Error on master socket\n" );
 285         release_object( obj );
 286     }
 287     else if (event & POLLIN)
 288     {
 289         struct sockaddr_un dummy;
 290         int len = sizeof(dummy);
 291         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 292         if (client != -1) create_process( client, NULL, NULL, "", 1 );
 293     }
 294 }
 295
 296 /* remove the socket upon exit */
 297 static void socket_cleanup(void)
 298 {
 299     unlink( SOCKETNAME );
 300 }
 301
 302 static void master_socket_destroy( struct object *obj )
 303 {
 304     socket_cleanup();
 305 }
 306
 307 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 308 static const char *get_config_dir(void)
 309 {
 310     static char *confdir;
 311     if (!confdir)
 312     {
 313         const char *prefix = getenv( "WINEPREFIX" );
 314         if (prefix)
 315         {
 316             int len = strlen(prefix);
 317             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 318             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 319         }
 320         else
 321         {
 322             const char *home = getenv( "HOME" );
 323             if (!home)
 324             {
 325                 struct passwd *pwd = getpwuid( getuid() );
 326                 if (!pwd) fatal_error( "could not find your home directory\n" );
 327                 home = pwd->pw_dir;
 328             }
 329             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 330                 fatal_error( "out of memory\n" );
 331             strcpy( confdir, home );
 332             strcat( confdir, CONFDIR );
 333         }
 334         mkdir( confdir, 0755 );  /* just in case */
 335     }
 336     return confdir;
 337 }
 338
 339 /* create the server directory and chdir to it */
 340 static void create_server_dir(void)
 341 {
 342     char hostname[64];
 343     char *serverdir;
 344     const char *confdir = get_config_dir();
 345     struct stat st;
 346
 347     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 348
 349     if (!(serverdir = malloc( strlen(confdir) + strlen(SERVERDIR) + strlen(hostname) + 1 )))
 350         fatal_error( "out of memory\n" );
 351
 352     strcpy( serverdir, confdir );
 353     strcat( serverdir, SERVERDIR );
 354     strcat( serverdir, hostname );
 355
 356     if (chdir( serverdir ) == -1)
 357     {
 358         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 359         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 360         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 361     }
 362     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 363     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 364     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 365     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 366 }
 367
 368 /* open the master server socket and start waiting for new clients */
 369 void open_master_socket(void)
 370 {
 371     struct sockaddr_un addr;
 372     int fd, slen;
 373
 374     create_server_dir();
 375     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 376     addr.sun_family = AF_UNIX;
 377     strcpy( addr.sun_path, SOCKETNAME );
 378     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 379 #ifdef HAVE_SOCKADDR_SUN_LEN
 380     addr.sun_len = slen;
 381 #endif
 382     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 383     {
 384         if ((errno == EEXIST) || (errno == EADDRINUSE))
 385             fatal_error( "another server is already running\n" );
 386         else
 387             fatal_perror( "bind" );
 388     }
 389     atexit( socket_cleanup );
 390
 391     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 392     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 393
 394     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 395         fatal_error( "out of memory\n" );
 396     set_select_events( &master_socket->obj, POLLIN );
 397
 398     /* go in the background */
 399     switch(fork())
 400     {
 401     case -1:
 402         fatal_perror( "fork" );
 403     case 0:
 404         setsid();
 405         break;
 406     default:
 407         _exit(0);  /* do not call atexit functions */
 408     }
 409 }
 410
 411 /* close the master socket and stop waiting for new clients */
 412 void close_master_socket(void)
 413 {
 414     release_object( master_socket );
 415 }
 416
 417 /* lock/unlock the master socket to stop accepting new clients */
 418 void lock_master_socket( int locked )
 419 {
 420     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 421 }