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 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 /* die on a fatal error */
 107 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 void fatal_perror( const char *err, ... )
 120 {
 121     va_list args;
 122
 123     va_start( args, err );
 124     fprintf( stderr, "wineserver: " );
 125     vfprintf( stderr, err, args );
 126     perror( " " );
 127     va_end( args );
 128     exit(1);
 129 }
 130
 131 /* call a request handler */
 132 static inline void call_req_handler( struct thread *thread )
 133 {
 134     enum request req;
 135     current = thread;
 136     clear_error();
 137
 138     req = ((struct request_header *)current->buffer)->req;
 139
 140     if (debug_level) trace_request( req );
 141
 142     if (req < REQ_NB_REQUESTS)
 143     {
 144         req_handlers[req]( current->buffer );
 145         if (current && !current->wait) send_reply( current );
 146         current = NULL;
 147         return;
 148     }
 149     fatal_protocol_error( current, "bad request %d\n", req );
 150 }
 151
 152 /* set the fd to pass to the thread */
 153 void set_reply_fd( struct thread *thread, int pass_fd )
 154 {
 155     assert( thread->pass_fd == -1 );
 156     thread->pass_fd = pass_fd;
 157 }
 158
 159 /* send a reply to a thread */
 160 void send_reply( struct thread *thread )
 161 {
 162     assert( !thread->wait );
 163     if (debug_level) trace_reply( thread );
 164     if (!write_request( thread )) set_select_events( &thread->obj, POLLOUT );
 165 }
 166
 167 /* read a message from a client that has something to say */
 168 void read_request( struct thread *thread )
 169 {
 170     int ret;
 171     char dummy[1];
 172
 173 #ifdef HAVE_MSGHDR_ACCRIGHTS
 174     msghdr.msg_accrightslen = sizeof(int);
 175     msghdr.msg_accrights = (void *)&thread->pass_fd;
 176 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 177     msghdr.msg_control    = &cmsg;
 178     msghdr.msg_controllen = sizeof(cmsg);
 179     cmsg.fd = -1;
 180 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 181
 182     assert( thread->pass_fd == -1 );
 183
 184     myiovec.iov_base = dummy;
 185     myiovec.iov_len  = 1;
 186
 187     ret = recvmsg( thread->obj.fd, &msghdr, 0 );
 188 #ifndef HAVE_MSGHDR_ACCRIGHTS
 189     thread->pass_fd = cmsg.fd;
 190 #endif
 191
 192     if (ret > 0)
 193     {
 194         call_req_handler( thread );
 195         thread->pass_fd = -1;
 196         return;
 197     }
 198     if (!ret)  /* closed pipe */
 199     {
 200         kill_thread( thread, 0 );
 201         return;
 202     }
 203     perror("recvmsg");
 204     thread->exit_code = 1;
 205     kill_thread( thread, 1 );
 206 }
 207
 208 /* send a message to a client that is ready to receive something */
 209 int write_request( struct thread *thread )
 210 {
 211     int ret;
 212     struct request_header *header = thread->buffer;
 213
 214     header->error = thread->error;
 215
 216     if (thread->pass_fd == -1)
 217     {
 218         /* write a single byte; the value is ignored anyway */
 219         ret = write( thread->obj.fd, header, 1 );
 220     }
 221     else  /* we have an fd to send */
 222     {
 223 #ifdef HAVE_MSGHDR_ACCRIGHTS
 224         msghdr.msg_accrightslen = sizeof(int);
 225         msghdr.msg_accrights = (void *)&thread->pass_fd;
 226 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 227         msghdr.msg_control    = &cmsg;
 228         msghdr.msg_controllen = sizeof(cmsg);
 229         cmsg.fd = thread->pass_fd;
 230 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 231
 232         myiovec.iov_base = (void *)header;
 233         myiovec.iov_len  = 1;
 234
 235         ret = sendmsg( thread->obj.fd, &msghdr, 0 );
 236         close( thread->pass_fd );
 237         thread->pass_fd = -1;
 238     }
 239     if (ret > 0)
 240     {
 241         set_select_events( &thread->obj, POLLIN );
 242         return 1;
 243     }
 244     if (errno == EWOULDBLOCK) return 0;  /* not a fatal error */
 245     if (errno == EPIPE)
 246     {
 247         kill_thread( thread, 0 );  /* normal death */
 248     }
 249     else
 250     {
 251         perror("sendmsg");
 252         thread->exit_code = 1;
 253         kill_thread( thread, 1 );
 254     }
 255     return -1;
 256 }
 257
 258 static void master_socket_dump( struct object *obj, int verbose )
 259 {
 260     struct master_socket *sock = (struct master_socket *)obj;
 261     assert( obj->ops == &master_socket_ops );
 262     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 263 }
 264
 265 /* handle a socket event */
 266 static void master_socket_poll_event( struct object *obj, int event )
 267 {
 268     struct master_socket *sock = (struct master_socket *)obj;
 269     assert( obj->ops == &master_socket_ops );
 270
 271     assert( sock == master_socket );  /* there is only one master socket */
 272
 273     if (event & (POLLERR | POLLHUP))
 274     {
 275         /* this is not supposed to happen */
 276         fprintf( stderr, "wineserver: Error on master socket\n" );
 277         release_object( obj );
 278     }
 279     else if (event & POLLIN)
 280     {
 281         struct sockaddr_un dummy;
 282         int len = sizeof(dummy);
 283         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 284         if (client != -1) create_process( client );
 285     }
 286 }
 287
 288 /* remove the socket upon exit */
 289 static void socket_cleanup(void)
 290 {
 291     static int do_it_once;
 292     if (!do_it_once++) unlink( SOCKETNAME );
 293 }
 294
 295 static void master_socket_destroy( struct object *obj )
 296 {
 297     socket_cleanup();
 298 }
 299
 300 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 301 const char *get_config_dir(void)
 302 {
 303     static char *confdir;
 304     if (!confdir)
 305     {
 306         const char *prefix = getenv( "WINEPREFIX" );
 307         if (prefix)
 308         {
 309             int len = strlen(prefix);
 310             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 311             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 312         }
 313         else
 314         {
 315             const char *home = getenv( "HOME" );
 316             if (!home)
 317             {
 318                 struct passwd *pwd = getpwuid( getuid() );
 319                 if (!pwd) fatal_error( "could not find your home directory\n" );
 320                 home = pwd->pw_dir;
 321             }
 322             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 323                 fatal_error( "out of memory\n" );
 324             strcpy( confdir, home );
 325             strcat( confdir, CONFDIR );
 326         }
 327         mkdir( confdir, 0755 );  /* just in case */
 328     }
 329     return confdir;
 330 }
 331
 332 /* create the server directory and chdir to it */
 333 static void create_server_dir(void)
 334 {
 335     char hostname[64];
 336     char *serverdir;
 337     const char *confdir = get_config_dir();
 338     struct stat st;
 339
 340     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 341
 342     if (!(serverdir = malloc( strlen(confdir) + strlen(SERVERDIR) + strlen(hostname) + 1 )))
 343         fatal_error( "out of memory\n" );
 344
 345     strcpy( serverdir, confdir );
 346     strcat( serverdir, SERVERDIR );
 347     strcat( serverdir, hostname );
 348
 349     if (chdir( serverdir ) == -1)
 350     {
 351         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 352         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 353         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 354     }
 355     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 356     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 357     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 358     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 359 }
 360
 361 /* open the master server socket and start waiting for new clients */
 362 void open_master_socket(void)
 363 {
 364     struct sockaddr_un addr;
 365     int fd, slen;
 366
 367     create_server_dir();
 368     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 369     addr.sun_family = AF_UNIX;
 370     strcpy( addr.sun_path, SOCKETNAME );
 371     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 372 #ifdef HAVE_SOCKADDR_SUN_LEN
 373     addr.sun_len = slen;
 374 #endif
 375     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 376     {
 377         if ((errno == EEXIST) || (errno == EADDRINUSE))
 378             exit(0);  /* pretend we succeeded to start */
 379         else
 380             fatal_perror( "bind" );
 381     }
 382     atexit( socket_cleanup );
 383
 384     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 385     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 386
 387     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 388         fatal_error( "out of memory\n" );
 389     set_select_events( &master_socket->obj, POLLIN );
 390
 391     /* setup msghdr structure constant fields */
 392     msghdr.msg_name    = NULL;
 393     msghdr.msg_namelen = 0;
 394     msghdr.msg_iov     = &myiovec;
 395     msghdr.msg_iovlen  = 1;
 396
 397     /* go in the background */
 398     switch(fork())
 399     {
 400     case -1:
 401         fatal_perror( "fork" );
 402     case 0:
 403         setsid();
 404         break;
 405     default:
 406         _exit(0);  /* do not call atexit functions */
 407     }
 408 }
 409
 410 /* close the master socket and stop waiting for new clients */
 411 void close_master_socket(void)
 412 {
 413     /* if a new client is waiting, we keep on running */
 414     if (!check_select_events( master_socket->obj.fd, POLLIN ))
 415         release_object( master_socket );
 416 }
 417
 418 /* lock/unlock the master socket to stop accepting new clients */
 419 void lock_master_socket( int locked )
 420 {
 421     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 422 }