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_read_fd,                    /* get_read_fd */
  68     no_write_fd,                   /* get_write_fd */
  69     no_flush,                      /* flush */
  70     no_get_file_info,              /* get_file_info */
  71     master_socket_destroy          /* destroy */
  72 };
  73
  74
  75 struct thread *current = NULL;  /* thread handling the current request */
  76 unsigned int global_error = 0;  /* global error code for when no thread is current */
  77
  78 static struct master_socket *master_socket;  /* the master socket object */
  79
  80 /* socket communication static structures */
  81 static struct iovec myiovec;
  82 static struct msghdr msghdr;
  83 #ifndef HAVE_MSGHDR_ACCRIGHTS
  84 struct cmsg_fd
  85 {
  86     int len;   /* sizeof structure */
  87     int level; /* SOL_SOCKET */
  88     int type;  /* SCM_RIGHTS */
  89     int fd;    /* fd to pass */
  90 };
  91 static struct cmsg_fd cmsg = { sizeof(cmsg), SOL_SOCKET, SCM_RIGHTS, -1 };
  92 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
  93
  94 /* complain about a protocol error and terminate the client connection */
  95 void fatal_protocol_error( struct thread *thread, const char *err, ... )
  96 {
  97     va_list args;
  98
  99     va_start( args, err );
 100     fprintf( stderr, "Protocol error:%p: ", thread );
 101     vfprintf( stderr, err, args );
 102     va_end( args );
 103     thread->exit_code = 1;
 104     kill_thread( thread, 1 );
 105 }
 106
 107 /* die on a fatal error */
 108 void fatal_error( const char *err, ... )
 109 {
 110     va_list args;
 111
 112     va_start( args, err );
 113     fprintf( stderr, "wineserver: " );
 114     vfprintf( stderr, err, args );
 115     va_end( args );
 116     exit(1);
 117 }
 118
 119 /* die on a fatal error */
 120 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 )
 134 {
 135     enum request req;
 136     current = thread;
 137     clear_error();
 138
 139     req = ((struct request_header *)current->buffer)->req;
 140
 141     if (debug_level) trace_request( req );
 142
 143     if (req < REQ_NB_REQUESTS)
 144     {
 145         req_handlers[req]( current->buffer );
 146         if (current && !current->wait) send_reply( current );
 147         current = NULL;
 148         return;
 149     }
 150     fatal_protocol_error( current, "bad request %d\n", req );
 151 }
 152
 153 /* set the fd to pass to the thread */
 154 void set_reply_fd( struct thread *thread, int pass_fd )
 155 {
 156     assert( thread->pass_fd == -1 );
 157     thread->pass_fd = pass_fd;
 158 }
 159
 160 /* send a reply to a thread */
 161 void send_reply( struct thread *thread )
 162 {
 163     assert( !thread->wait );
 164     if (debug_level) trace_reply( thread );
 165     if (!write_request( thread )) set_select_events( &thread->obj, POLLOUT );
 166 }
 167
 168 /* read a message from a client that has something to say */
 169 void read_request( struct thread *thread )
 170 {
 171     int ret;
 172     char dummy[1];
 173
 174 #ifdef HAVE_MSGHDR_ACCRIGHTS
 175     msghdr.msg_accrightslen = sizeof(int);
 176     msghdr.msg_accrights = (void *)&thread->pass_fd;
 177 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 178     msghdr.msg_control    = &cmsg;
 179     msghdr.msg_controllen = sizeof(cmsg);
 180     cmsg.fd = -1;
 181 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 182
 183     assert( thread->pass_fd == -1 );
 184
 185     myiovec.iov_base = dummy;
 186     myiovec.iov_len  = 1;
 187
 188     ret = recvmsg( thread->obj.fd, &msghdr, 0 );
 189 #ifndef HAVE_MSGHDR_ACCRIGHTS
 190     thread->pass_fd = cmsg.fd;
 191 #endif
 192
 193     if (ret > 0)
 194     {
 195         call_req_handler( thread );
 196         thread->pass_fd = -1;
 197         return;
 198     }
 199     if (!ret)  /* closed pipe */
 200     {
 201         kill_thread( thread, 0 );
 202         return;
 203     }
 204     perror("recvmsg");
 205     thread->exit_code = 1;
 206     kill_thread( thread, 1 );
 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     struct request_header *header = thread->buffer;
 214
 215     header->error = thread->error;
 216
 217     if (thread->pass_fd == -1)
 218     {
 219         /* write a single byte; the value is ignored anyway */
 220         ret = write( thread->obj.fd, header, 1 );
 221     }
 222     else  /* we have an fd to send */
 223     {
 224 #ifdef HAVE_MSGHDR_ACCRIGHTS
 225         msghdr.msg_accrightslen = sizeof(int);
 226         msghdr.msg_accrights = (void *)&thread->pass_fd;
 227 #else  /* HAVE_MSGHDR_ACCRIGHTS */
 228         msghdr.msg_control    = &cmsg;
 229         msghdr.msg_controllen = sizeof(cmsg);
 230         cmsg.fd = thread->pass_fd;
 231 #endif  /* HAVE_MSGHDR_ACCRIGHTS */
 232
 233         myiovec.iov_base = (void *)header;
 234         myiovec.iov_len  = 1;
 235
 236         ret = sendmsg( thread->obj.fd, &msghdr, 0 );
 237         close( thread->pass_fd );
 238         thread->pass_fd = -1;
 239     }
 240     if (ret > 0)
 241     {
 242         set_select_events( &thread->obj, POLLIN );
 243         return 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     return -1;
 257 }
 258
 259 static void master_socket_dump( struct object *obj, int verbose )
 260 {
 261     struct master_socket *sock = (struct master_socket *)obj;
 262     assert( obj->ops == &master_socket_ops );
 263     fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
 264 }
 265
 266 /* handle a socket event */
 267 static void master_socket_poll_event( struct object *obj, int event )
 268 {
 269     struct master_socket *sock = (struct master_socket *)obj;
 270     assert( obj->ops == &master_socket_ops );
 271
 272     assert( sock == master_socket );  /* there is only one master socket */
 273
 274     if (event & (POLLERR | POLLHUP))
 275     {
 276         /* this is not supposed to happen */
 277         fprintf( stderr, "wineserver: Error on master socket\n" );
 278         release_object( obj );
 279     }
 280     else if (event & POLLIN)
 281     {
 282         struct sockaddr_un dummy;
 283         int len = sizeof(dummy);
 284         int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
 285         if (client != -1) create_process( client );
 286     }
 287 }
 288
 289 /* remove the socket upon exit */
 290 static void socket_cleanup(void)
 291 {
 292     static int do_it_once;
 293     if (!do_it_once++) unlink( SOCKETNAME );
 294 }
 295
 296 static void master_socket_destroy( struct object *obj )
 297 {
 298     socket_cleanup();
 299 }
 300
 301 /* return the configuration directory ($WINEPREFIX or $HOME/.wine) */
 302 const char *get_config_dir(void)
 303 {
 304     static char *confdir;
 305     if (!confdir)
 306     {
 307         const char *prefix = getenv( "WINEPREFIX" );
 308         if (prefix)
 309         {
 310             int len = strlen(prefix);
 311             if (!(confdir = strdup( prefix ))) fatal_error( "out of memory\n" );
 312             if (len > 1 && confdir[len-1] == '/') confdir[len-1] = 0;
 313         }
 314         else
 315         {
 316             const char *home = getenv( "HOME" );
 317             if (!home)
 318             {
 319                 struct passwd *pwd = getpwuid( getuid() );
 320                 if (!pwd) fatal_error( "could not find your home directory\n" );
 321                 home = pwd->pw_dir;
 322             }
 323             if (!(confdir = malloc( strlen(home) + strlen(CONFDIR) + 1 )))
 324                 fatal_error( "out of memory\n" );
 325             strcpy( confdir, home );
 326             strcat( confdir, CONFDIR );
 327         }
 328         mkdir( confdir, 0755 );  /* just in case */
 329     }
 330     return confdir;
 331 }
 332
 333 /* create the server directory and chdir to it */
 334 static void create_server_dir(void)
 335 {
 336     char hostname[64];
 337     char *serverdir;
 338     const char *confdir = get_config_dir();
 339     struct stat st;
 340
 341     if (gethostname( hostname, sizeof(hostname) ) == -1) fatal_perror( "gethostname" );
 342
 343     if (!(serverdir = malloc( strlen(confdir) + strlen(SERVERDIR) + strlen(hostname) + 1 )))
 344         fatal_error( "out of memory\n" );
 345
 346     strcpy( serverdir, confdir );
 347     strcat( serverdir, SERVERDIR );
 348     strcat( serverdir, hostname );
 349
 350     if (chdir( serverdir ) == -1)
 351     {
 352         if (errno != ENOENT) fatal_perror( "chdir %s", serverdir );
 353         if (mkdir( serverdir, 0700 ) == -1) fatal_perror( "mkdir %s", serverdir );
 354         if (chdir( serverdir ) == -1) fatal_perror( "chdir %s", serverdir );
 355     }
 356     if (stat( ".", &st ) == -1) fatal_perror( "stat %s", serverdir );
 357     if (!S_ISDIR(st.st_mode)) fatal_error( "%s is not a directory\n", serverdir );
 358     if (st.st_uid != getuid()) fatal_error( "%s is not owned by you\n", serverdir );
 359     if (st.st_mode & 077) fatal_error( "%s must not be accessible by other users\n", serverdir );
 360 }
 361
 362 /* open the master server socket and start waiting for new clients */
 363 void open_master_socket(void)
 364 {
 365     struct sockaddr_un addr;
 366     int fd, slen;
 367
 368     create_server_dir();
 369     if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
 370     addr.sun_family = AF_UNIX;
 371     strcpy( addr.sun_path, SOCKETNAME );
 372     slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
 373 #ifdef HAVE_SOCKADDR_SUN_LEN
 374     addr.sun_len = slen;
 375 #endif
 376     if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
 377     {
 378         if ((errno == EEXIST) || (errno == EADDRINUSE))
 379             exit(0);  /* pretend we succeeded to start */
 380         else
 381             fatal_perror( "bind" );
 382     }
 383     atexit( socket_cleanup );
 384
 385     chmod( SOCKETNAME, 0600 );  /* make sure no other user can connect */
 386     if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
 387
 388     if (!(master_socket = alloc_object( &master_socket_ops, fd )))
 389         fatal_error( "out of memory\n" );
 390     set_select_events( &master_socket->obj, POLLIN );
 391
 392     /* setup msghdr structure constant fields */
 393     msghdr.msg_name    = NULL;
 394     msghdr.msg_namelen = 0;
 395     msghdr.msg_iov     = &myiovec;
 396     msghdr.msg_iovlen  = 1;
 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     /* if a new client is waiting, we keep on running */
 415     if (!check_select_events( master_socket->obj.fd, POLLIN ))
 416         release_object( master_socket );
 417 }
 418
 419 /* lock/unlock the master socket to stop accepting new clients */
 420 void lock_master_socket( int locked )
 421 {
 422     set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
 423 }