reactos/dll/win32/libtirpc/src/auth_time.c

   1 /*
   2  *      auth_time.c
   3  *
   4  * This module contains the private function __rpc_get_time_offset()
   5  * which will return the difference in seconds between the local system's
   6  * notion of time and a remote server's notion of time. This must be
   7  * possible without calling any functions that may invoke the name
   8  * service. (netdir_getbyxxx, getXbyY, etc). The function is used in the
   9  * synchronize call of the authdes code to synchronize clocks between
  10  * NIS+ clients and their servers.
  11  *
  12  * Note to minimize the amount of duplicate code, portions of the
  13  * synchronize() function were folded into this code, and the synchronize
  14  * call becomes simply a wrapper around this function. Further, if this
  15  * function is called with a timehost it *DOES* recurse to the name
  16  * server so don't use it in that mode if you are doing name service code.
  17  *
  18  *      Copyright (c) 1992 Sun Microsystems Inc.
  19  *      All rights reserved.
  20  *
  21  * Side effects :
  22  *      When called a client handle to a RPCBIND process is created
  23  *      and destroyed. Two strings "netid" and "uaddr" are malloc'd
  24  *      and returned. The SIGALRM processing is modified only if
  25  *      needed to deal with TCP connections.
  26  */
  27
  28 //#include <sys/cdefs.h>
  29 #include <wintirpc.h>
  30 //#include <syslog.h>
  31 #include <string.h>
  32 #include <stdlib.h>
  33 //#include <unistd.h>
  34 //#include <netdb.h>
  35 //#include <sys/signal.h>
  36 #include <errno.h>
  37 //#include <sys/socket.h>
  38 //#include <netinet/in.h>
  39 //#include <arpa/inet.h>
  40
  41 #include <rpc/rpc.h>
  42 #include <rpc/rpc_com.h>
  43 #include <rpc/rpcb_prot.h>
  44 //#include <clnt_soc.h>
  45 //#include <sys/select.h>
  46 #undef NIS
  47 #include <rpcsvc/nis.h>
  48
  49
  50 #ifdef TESTING
  51 #define msg(x)  printf("ERROR: %s\n", x)
  52 /* #define msg(x) syslog(LOG_ERR, "%s", x) */
  53 #else
  54 #define msg(x)
  55 #endif
  56
  57 static int saw_alarm = 0;
  58
  59 static void
  60 alarm_hndler(s)
  61         int     s;
  62 {
  63         saw_alarm = 1;
  64         return;
  65 }
  66
  67 /*
  68  * The internet time server defines the epoch to be Jan 1, 1900
  69  * whereas UNIX defines it to be Jan 1, 1970. To adjust the result
  70  * from internet time-service time, into UNIX time we subtract the
  71  * following offset :
  72  */
  73 #define NYEARS  (1970 - 1900)
  74 #define TOFFSET ((u_long)60*60*24*(365*NYEARS + (NYEARS/4)))
  75
  76
  77 /*
  78  * Stolen from rpc.nisd:
  79  * Turn a 'universal address' into a struct sockaddr_in.
  80  * Bletch.
  81  */
  82 static int uaddr_to_sockaddr(uaddr, sin)
  83 #ifdef foo
  84         endpoint                *endpt;
  85 #endif
  86         char                    *uaddr;
  87         struct sockaddr_in      *sin;
  88 {
  89         unsigned char           p_bytes[2];
  90         int                     i;
  91         unsigned long           a[6];
  92
  93         i = sscanf(uaddr, "%lu.%lu.%lu.%lu.%lu.%lu", &a[0], &a[1], &a[2],
  94                                                 &a[3], &a[4], &a[5]);
  95
  96         if (i < 6)
  97                 return(1);
  98
  99         for (i = 0; i < 4; i++)
 100                 sin->sin_addr.s_addr |= (a[i] & 0x000000FF) << (8 * i);
 101
 102         p_bytes[0] = (unsigned char)a[4] & 0x000000FF;
 103         p_bytes[1] = (unsigned char)a[5] & 0x000000FF;
 104
 105         sin->sin_family = AF_INET; /* always */
 106         bcopy((char *)&p_bytes, (char *)&sin->sin_port, 2);
 107
 108         return (0);
 109 }
 110
 111 /*
 112  * free_eps()
 113  *
 114  * Free the strings that were strduped into the eps structure.
 115  */
 116 static void
 117 free_eps(eps, num)
 118         endpoint        eps[];
 119         int             num;
 120 {
 121         int             i;
 122
 123         for (i = 0; i < num; i++) {
 124                 free(eps[i].uaddr);
 125                 free(eps[i].proto);
 126                 free(eps[i].family);
 127         }
 128         return;
 129 }
 130
 131 /*
 132  * get_server()
 133  *
 134  * This function constructs a nis_server structure description for the
 135  * indicated hostname.
 136  *
 137  * NOTE: There is a chance we may end up recursing here due to the
 138  * fact that gethostbyname() could do an NIS search. Ideally, the
 139  * NIS+ server will call __rpc_get_time_offset() with the nis_server
 140  * structure already populated.
 141  */
 142 static nis_server *
 143 get_server(sin, host, srv, eps, maxep)
 144         struct sockaddr_in *sin;
 145         char            *host;  /* name of the time host        */
 146         nis_server      *srv;   /* nis_server struct to use.    */
 147         endpoint        eps[];  /* array of endpoints           */
 148         int             maxep;  /* max array size               */
 149 {
 150         char                    hname[256];
 151         int                     num_ep = 0, i;
 152         struct hostent          *he;
 153         struct hostent          dummy;
 154         char                    *ptr[2];
 155
 156         if (host == NULL && sin == NULL)
 157                 return (NULL);
 158
 159         if (sin == NULL) {
 160                 he = gethostbyname(host);
 161                 if (he == NULL)
 162                         return(NULL);
 163         } else {
 164                 he = &dummy;
 165                 ptr[0] = (char *)&sin->sin_addr.s_addr;
 166                 ptr[1] = NULL;
 167                 dummy.h_addr_list = ptr;
 168         }
 169
 170         /*
 171          * This is lame. We go around once for TCP, then again
 172          * for UDP.
 173          */
 174         for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
 175                                                 i++, num_ep++) {
 176                 struct in_addr *a;
 177
 178                 a = (struct in_addr *)he->h_addr_list[i];
 179                 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
 180                 eps[num_ep].uaddr = strdup(hname);
 181                 eps[num_ep].family = strdup("inet");
 182                 eps[num_ep].proto =  strdup("tcp");
 183         }
 184
 185         for (i = 0; (he->h_addr_list[i] != NULL) && (num_ep < maxep);
 186                                                 i++, num_ep++) {
 187                 struct in_addr *a;
 188
 189                 a = (struct in_addr *)he->h_addr_list[i];
 190                 snprintf(hname, sizeof(hname), "%s.0.111", inet_ntoa(*a));
 191                 eps[num_ep].uaddr = strdup(hname);
 192                 eps[num_ep].family = strdup("inet");
 193                 eps[num_ep].proto =  strdup("udp");
 194         }
 195
 196         srv->name = (nis_name) host;
 197         srv->ep.ep_len = num_ep;
 198         srv->ep.ep_val = eps;
 199         srv->key_type = NIS_PK_NONE;
 200         srv->pkey.n_bytes = NULL;
 201         srv->pkey.n_len = 0;
 202         return (srv);
 203 }
 204
 205 /*
 206  * __rpc_get_time_offset()
 207  *
 208  * This function uses a nis_server structure to contact the a remote
 209  * machine (as named in that structure) and returns the offset in time
 210  * between that machine and this one. This offset is returned in seconds
 211  * and may be positive or negative.
 212  *
 213  * The first time through, a lot of fiddling is done with the netconfig
 214  * stuff to find a suitable transport. The function is very aggressive
 215  * about choosing UDP or at worst TCP if it can. This is because
 216  * those transports support both the RCPBIND call and the internet
 217  * time service.
 218  *
 219  * Once through, *uaddr is set to the universal address of
 220  * the machine and *netid is set to the local netid for the transport
 221  * that uaddr goes with. On the second call, the netconfig stuff
 222  * is skipped and the uaddr/netid pair are used to fetch the netconfig
 223  * structure and to then contact the machine for the time.
 224  *
 225  * td = "server" - "client"
 226  */
 227 int
 228 __rpc_get_time_offset(td, srv, thost, uaddr, netid)
 229         struct timeval  *td;     /* Time difference                     */
 230         nis_server      *srv;    /* NIS Server description              */
 231         char            *thost;  /* if no server, this is the timehost  */
 232         char            **uaddr; /* known universal address             */
 233         struct sockaddr_in *netid; /* known network identifier          */
 234 {
 235         CLIENT                  *clnt;          /* Client handle        */
 236         endpoint                *ep,            /* useful endpoints     */
 237                                 *useep = NULL;  /* endpoint of xp       */
 238         char                    *useua = NULL;  /* uaddr of selected xp */
 239         int                     epl, i;         /* counters             */
 240         enum clnt_stat          status;         /* result of clnt_call  */
 241         long                    thetime;
 242         long                    delta;
 243         int                     needfree = 0;
 244         struct timeval          tv;
 245         int                     time_valid;
 246         int                     udp_ep = -1, tcp_ep = -1;
 247         int                     a1, a2, a3, a4;
 248         char                    ut[64], ipuaddr[64];
 249         endpoint                teps[32];
 250         nis_server              tsrv;
 251         void                    (*oldsig)() = NULL; /* old alarm handler */
 252         struct sockaddr_in      sin;
 253         SOCKET                  s = RPC_ANYSOCK;
 254         socklen_t len;
 255         int                     type = 0;
 256
 257         td->tv_sec = 0;
 258         td->tv_usec = 0;
 259
 260         /*
 261          * First check to see if we need to find and address for this
 262          * server.
 263          */
 264         if (*uaddr == NULL) {
 265                 if ((srv != NULL) && (thost != NULL)) {
 266                         msg("both timehost and srv pointer used!");
 267                         return (0);
 268                 }
 269                 if (! srv) {
 270                         srv = get_server(netid, thost, &tsrv, teps, 32);
 271                         if (srv == NULL) {
 272                                 msg("unable to contruct server data.");
 273                                 return (0);
 274                         }
 275                         needfree = 1;   /* need to free data in endpoints */
 276                 }
 277
 278                 ep = srv->ep.ep_val;
 279                 epl = srv->ep.ep_len;
 280
 281                 /* Identify the TCP and UDP endpoints */
 282                 for (i = 0;
 283                         (i < epl) && ((udp_ep == -1) || (tcp_ep == -1)); i++) {
 284                         if (strcasecmp(ep[i].proto, "udp") == 0)
 285                                 udp_ep = i;
 286                         if (strcasecmp(ep[i].proto, "tcp") == 0)
 287                                 tcp_ep = i;
 288                 }
 289
 290                 /* Check to see if it is UDP or TCP */
 291                 if (tcp_ep > -1) {
 292                         useep = &ep[tcp_ep];
 293                         useua = ep[tcp_ep].uaddr;
 294                         type = SOCK_STREAM;
 295                 } else if (udp_ep > -1) {
 296                         useep = &ep[udp_ep];
 297                         useua = ep[udp_ep].uaddr;
 298                         type = SOCK_DGRAM;
 299                 }
 300
 301                 if (useep == NULL) {
 302                         msg("no acceptable transport endpoints.");
 303                         if (needfree)
 304                                 free_eps(teps, tsrv.ep.ep_len);
 305                         return (0);
 306                 }
 307         }
 308
 309         /*
 310          * Create a sockaddr from the uaddr.
 311          */
 312         if (*uaddr != NULL)
 313                 useua = *uaddr;
 314
 315         /* Fixup test for NIS+ */
 316         sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
 317         sprintf(ipuaddr, "%d.%d.%d.%d.0.111", a1, a2, a3, a4);
 318         useua = &ipuaddr[0];
 319
 320         bzero((char *)&sin, sizeof(sin));
 321         if (uaddr_to_sockaddr(useua, &sin)) {
 322                 msg("unable to translate uaddr to sockaddr.");
 323                 if (needfree)
 324                         free_eps(teps, tsrv.ep.ep_len);
 325                 return (0);
 326         }
 327
 328         /*
 329          * Create the client handle to rpcbind. Note we always try
 330          * version 3 since that is the earliest version that supports
 331          * the RPCB_GETTIME call. Also it is the version that comes
 332          * standard with SVR4. Since most everyone supports TCP/IP
 333          * we could consider trying the rtime call first.
 334          */
 335         clnt = clnttcp_create(&sin, RPCBPROG, RPCBVERS, &s, 0, 0);
 336         if (clnt == NULL) {
 337                 msg("unable to create client handle to rpcbind.");
 338                 if (needfree)
 339                         free_eps(teps, tsrv.ep.ep_len);
 340                 return (0);
 341         }
 342
 343         tv.tv_sec = 5;
 344         tv.tv_usec = 0;
 345         time_valid = 0;
 346         status = clnt_call(clnt, RPCBPROC_GETTIME, (xdrproc_t)xdr_void, NULL,
 347                                         (xdrproc_t)xdr_u_long, &thetime, tv);
 348         /*
 349          * The only error we check for is anything but success. In
 350          * fact we could have seen PROGMISMATCH if talking to a 4.1
 351          * machine (pmap v2) or TIMEDOUT if the net was busy.
 352          */
 353         if (status == RPC_SUCCESS)
 354                 time_valid = 1;
 355         else {
 356                 int save;
 357
 358                 /* Blow away possible stale CLNT handle. */
 359                 if (clnt != NULL) {
 360                         clnt_destroy(clnt);
 361                         clnt = NULL;
 362                 }
 363
 364                 /*
 365                  * Convert PMAP address into timeservice address
 366                  * We take advantage of the fact that we "know" what
 367                  * the universal address looks like for inet transports.
 368                  *
 369                  * We also know that the internet timeservice is always
 370                  * listening on port 37.
 371                  */
 372                 sscanf(useua, "%d.%d.%d.%d.", &a1, &a2, &a3, &a4);
 373                 sprintf(ut, "%d.%d.%d.%d.0.37", a1, a2, a3, a4);
 374
 375                 if (uaddr_to_sockaddr(ut, &sin)) {
 376                         msg("cannot convert timeservice uaddr to sockaddr.");
 377                         goto error;
 378                 }
 379
 380                 s = socket(AF_INET, type, 0);
 381                 if (s == INVALID_SOCKET) {
 382                         msg("unable to open fd to network.");
 383                         goto error;
 384                 }
 385
 386                 /*
 387                  * Now depending on whether or not we're talking to
 388                  * UDP we set a timeout or not.
 389                  */
 390                 if (type == SOCK_DGRAM) {
 391                         struct timeval timeout = { 20, 0 };
 392                         struct sockaddr_in from;
 393                         fd_set readfds;
 394                         int res;
 395
 396                         if (sendto(s, (const char *)&thetime, sizeof(thetime), 0,
 397                                 (struct sockaddr *)&sin, sizeof(sin)) == -1) {
 398                                 msg("udp : sendto failed.");
 399                                 goto error;
 400                         }
 401                         do {
 402                                 FD_ZERO(&readfds);
 403                                 FD_SET(s, &readfds);
 404                                 res = select(_rpc_dtablesize(), &readfds,
 405                                      (fd_set *)NULL, (fd_set *)NULL, &timeout);
 406                         } while (res == SOCKET_ERROR && WSAGetLastError() == WSAEINTR);
 407                         if (res == SOCKET_ERROR)
 408                                 goto error;
 409                         len = sizeof(from);
 410                         res = recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
 411                                        (struct sockaddr *)&from, &len);
 412                         if (res == SOCKET_ERROR) {
 413                                 msg("recvfrom failed on udp transport.");
 414                                 goto error;
 415                         }
 416                         time_valid = 1;
 417                 } else {
 418                         int res;
 419 #ifndef _WIN32
 420                         oldsig = (void (*)())signal(SIGALRM, alarm_hndler);
 421                         saw_alarm = 0; /* global tracking the alarm */
 422                         alarm(20); /* only wait 20 seconds */
 423 #else
 424                         saw_alarm = 0;
 425                         /* XXX Need Windows signal/alarm stuff here XXX */
 426 #endif
 427                         res = connect(s, (struct sockaddr *)&sin, sizeof(sin));
 428                         if (res == SOCKET_ERROR) {
 429                                 msg("failed to connect to tcp endpoint.");
 430                                 goto error;
 431                         }
 432                         if (saw_alarm) {
 433                                 msg("alarm caught it, must be unreachable.");
 434                                 goto error;
 435                         }
 436 //                      res = read(s, (char *)&thetime, sizeof(thetime));
 437                         res = recv(s, (char *)&thetime, sizeof(thetime), 0);
 438                         if (res != sizeof(thetime)) {
 439                                 if (saw_alarm)
 440                                         msg("timed out TCP call.");
 441                                 else
 442                                         msg("wrong size of results returned");
 443
 444                                 goto error;
 445                         }
 446                         time_valid = 1;
 447                 }
 448                 save = WSAGetLastError();
 449                 (void)closesocket(s);
 450                 errno = save;
 451                 s = RPC_ANYSOCK;
 452
 453                 if (time_valid) {
 454                         thetime = ntohl(thetime);
 455                         thetime = thetime - TOFFSET; /* adjust to UNIX time */
 456                 } else
 457                         thetime = 0;
 458         }
 459
 460         gettimeofday(&tv, 0);
 461
 462 error:
 463         /*
 464          * clean up our allocated data structures.
 465          */
 466
 467         if (s != RPC_ANYSOCK)
 468                 (void)closesocket(s);
 469
 470         if (clnt != NULL)
 471                 clnt_destroy(clnt);
 472
 473 #ifdef _WIN32
 474         /* XXX Need Windows signal/alarm stuff here XXX */
 475 #else
 476         alarm(0);       /* reset that alarm if its outstanding */
 477         if (oldsig) {
 478                 signal(SIGALRM, oldsig);
 479         }
 480 #endif
 481
 482         /*
 483          * note, don't free uaddr strings until after we've made a
 484          * copy of them.
 485          */
 486         if (time_valid) {
 487                 if (*uaddr == NULL)
 488                         *uaddr = strdup(useua);
 489
 490                 /* Round to the nearest second */
 491                 tv.tv_sec += (tv.tv_sec > 500000) ? 1 : 0;
 492                 delta = (thetime > tv.tv_sec) ? thetime - tv.tv_sec :
 493                                                 tv.tv_sec - thetime;
 494                 td->tv_sec = (thetime < tv.tv_sec) ? - delta : delta;
 495                 td->tv_usec = 0;
 496         } else {
 497                 msg("unable to get the server's time.");
 498         }
 499
 500         if (needfree)
 501                 free_eps(teps, tsrv.ep.ep_len);
 502
 503         return (time_valid);
 504 }