sunrpc/svc.c

   1 /*
   2  * svc.c, Server-side remote procedure call interface.
   3  *
   4  * There are two sets of procedures here.  The xprt routines are
   5  * for handling transport handles.  The svc routines handle the
   6  * list of service routines.
   7  *
   8  * Copyright (c) 2010, Oracle America, Inc.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions are
  12  * met:
  13  *
  14  *     * Redistributions of source code must retain the above copyright
  15  *       notice, this list of conditions and the following disclaimer.
  16  *     * Redistributions in binary form must reproduce the above
  17  *       copyright notice, this list of conditions and the following
  18  *       disclaimer in the documentation and/or other materials
  19  *       provided with the distribution.
  20  *     * Neither the name of the "Oracle America, Inc." nor the names of its
  21  *       contributors may be used to endorse or promote products derived
  22  *       from this software without specific prior written permission.
  23  *
  24  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  26  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  27  *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  28  *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  29  *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  30  *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  31  *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  33  *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  34  *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include <errno.h>
  39 #include <unistd.h>
  40 #include <rpc/rpc.h>
  41 #include <rpc/svc.h>
  42 #include <rpc/pmap_clnt.h>
  43 #include <sys/poll.h>
  44
  45 #ifdef _RPC_THREAD_SAFE_
  46 #define xports RPC_THREAD_VARIABLE(svc_xports_s)
  47 #else
  48 static SVCXPRT **xports;
  49 #endif
  50
  51 #define NULL_SVC ((struct svc_callout *)0)
  52 #define RQCRED_SIZE     400     /* this size is excessive */
  53
  54 /* The services list
  55    Each entry represents a set of procedures (an rpc program).
  56    The dispatch routine takes request structs and runs the
  57    appropriate procedure. */
  58 struct svc_callout {
  59   struct svc_callout *sc_next;
  60   rpcprog_t sc_prog;
  61   rpcvers_t sc_vers;
  62   void (*sc_dispatch) (struct svc_req *, SVCXPRT *);
  63   bool_t sc_mapped;
  64 };
  65 #ifdef _RPC_THREAD_SAFE_
  66 #define svc_head RPC_THREAD_VARIABLE(svc_head_s)
  67 #else
  68 static struct svc_callout *svc_head;
  69 #endif
  70
  71 /* ***************  SVCXPRT related stuff **************** */
  72
  73 /* Activate a transport handle. */
  74 void
  75 xprt_register (SVCXPRT *xprt)
  76 {
  77   register int sock = xprt->xp_sock;
  78   register int i;
  79
  80   if (xports == NULL)
  81     {
  82       xports = (SVCXPRT **) malloc (_rpc_dtablesize () * sizeof (SVCXPRT *));
  83       if (xports == NULL) /* Don´t add handle */
  84         return;
  85     }
  86
  87   if (sock < _rpc_dtablesize ())
  88     {
  89       struct pollfd *new_svc_pollfd;
  90
  91       xports[sock] = xprt;
  92       if (sock < FD_SETSIZE)
  93         FD_SET (sock, &svc_fdset);
  94
  95       /* Check if we have an empty slot */
  96       for (i = 0; i < svc_max_pollfd; ++i)
  97         if (svc_pollfd[i].fd == -1)
  98           {
  99             svc_pollfd[i].fd = sock;
 100             svc_pollfd[i].events = (POLLIN | POLLPRI |
 101                                     POLLRDNORM | POLLRDBAND);
 102             return;
 103           }
 104
 105       new_svc_pollfd = (struct pollfd *) realloc (svc_pollfd,
 106                                                   sizeof (struct pollfd)
 107                                                   * (svc_max_pollfd + 1));
 108       if (new_svc_pollfd == NULL) /* Out of memory */
 109         return;
 110       svc_pollfd = new_svc_pollfd;
 111       ++svc_max_pollfd;
 112
 113       svc_pollfd[svc_max_pollfd - 1].fd = sock;
 114       svc_pollfd[svc_max_pollfd - 1].events = (POLLIN | POLLPRI |
 115                                                POLLRDNORM | POLLRDBAND);
 116     }
 117 }
 118 libc_hidden_nolink_sunrpc (xprt_register, GLIBC_2_0)
 119
 120 /* De-activate a transport handle. */
 121 void
 122 xprt_unregister (SVCXPRT *xprt)
 123 {
 124   register int sock = xprt->xp_sock;
 125   register int i;
 126
 127   if ((sock < _rpc_dtablesize ()) && (xports[sock] == xprt))
 128     {
 129       xports[sock] = (SVCXPRT *) 0;
 130
 131       if (sock < FD_SETSIZE)
 132         FD_CLR (sock, &svc_fdset);
 133
 134       for (i = 0; i < svc_max_pollfd; ++i)
 135         if (svc_pollfd[i].fd == sock)
 136           svc_pollfd[i].fd = -1;
 137     }
 138 }
 139 #ifdef EXPORT_RPC_SYMBOLS
 140 libc_hidden_def (xprt_unregister)
 141 #else
 142 libc_hidden_nolink_sunrpc (xprt_unregister, GLIBC_2_0)
 143 #endif
 144
 145
 146 /* ********************** CALLOUT list related stuff ************* */
 147
 148 /* Search the callout list for a program number, return the callout
 149    struct. */
 150 static struct svc_callout *
 151 svc_find (rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev)
 152 {
 153   register struct svc_callout *s, *p;
 154
 155   p = NULL_SVC;
 156   for (s = svc_head; s != NULL_SVC; s = s->sc_next)
 157     {
 158       if ((s->sc_prog == prog) && (s->sc_vers == vers))
 159         goto done;
 160       p = s;
 161     }
 162 done:
 163   *prev = p;
 164   return s;
 165 }
 166
 167
 168 static bool_t
 169 svc_is_mapped (rpcprog_t prog, rpcvers_t vers)
 170 {
 171   struct svc_callout *prev;
 172   register struct svc_callout *s;
 173   s = svc_find (prog, vers, &prev);
 174   return s!= NULL_SVC && s->sc_mapped;
 175 }
 176
 177
 178 /* Add a service program to the callout list.
 179    The dispatch routine will be called when a rpc request for this
 180    program number comes in. */
 181 bool_t
 182 svc_register (SVCXPRT * xprt, rpcprog_t prog, rpcvers_t vers,
 183               void (*dispatch) (struct svc_req *, SVCXPRT *),
 184               rpcproc_t protocol)
 185 {
 186   struct svc_callout *prev;
 187   register struct svc_callout *s;
 188
 189   if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
 190     {
 191       if (s->sc_dispatch == dispatch)
 192         goto pmap_it;           /* he is registering another xptr */
 193       return FALSE;
 194     }
 195   s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
 196   if (s == (struct svc_callout *) 0)
 197     return FALSE;
 198
 199   s->sc_prog = prog;
 200   s->sc_vers = vers;
 201   s->sc_dispatch = dispatch;
 202   s->sc_next = svc_head;
 203   s->sc_mapped = FALSE;
 204   svc_head = s;
 205
 206 pmap_it:
 207   /* now register the information with the local binder service */
 208   if (protocol)
 209     {
 210       if (! pmap_set (prog, vers, protocol, xprt->xp_port))
 211         return FALSE;
 212
 213       s->sc_mapped = TRUE;
 214     }
 215
 216   return TRUE;
 217 }
 218 #ifdef EXPORT_RPC_SYMBOLS
 219 libc_hidden_def (svc_register)
 220 #else
 221 libc_hidden_nolink_sunrpc (svc_register, GLIBC_2_0)
 222 #endif
 223
 224 /* Remove a service program from the callout list. */
 225 void
 226 svc_unregister (rpcprog_t prog, rpcvers_t vers)
 227 {
 228   struct svc_callout *prev;
 229   register struct svc_callout *s;
 230
 231   if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
 232     return;
 233
 234   if (prev == NULL_SVC)
 235     svc_head = s->sc_next;
 236   else
 237     prev->sc_next = s->sc_next;
 238
 239   s->sc_next = NULL_SVC;
 240   mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
 241   /* now unregister the information with the local binder service */
 242   if (! svc_is_mapped (prog, vers))
 243     pmap_unset (prog, vers);
 244 }
 245 libc_hidden_nolink_sunrpc (svc_unregister, GLIBC_2_0)
 246
 247 /* ******************* REPLY GENERATION ROUTINES  ************ */
 248
 249 /* Send a reply to an rpc request */
 250 bool_t
 251 svc_sendreply (register SVCXPRT *xprt, xdrproc_t xdr_results,
 252                caddr_t xdr_location)
 253 {
 254   struct rpc_msg rply;
 255
 256   rply.rm_direction = REPLY;
 257   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 258   rply.acpted_rply.ar_verf = xprt->xp_verf;
 259   rply.acpted_rply.ar_stat = SUCCESS;
 260   rply.acpted_rply.ar_results.where = xdr_location;
 261   rply.acpted_rply.ar_results.proc = xdr_results;
 262   return SVC_REPLY (xprt, &rply);
 263 }
 264 #ifdef EXPORT_RPC_SYMBOLS
 265 libc_hidden_def (svc_sendreply)
 266 #else
 267 libc_hidden_nolink_sunrpc (svc_sendreply, GLIBC_2_0)
 268 #endif
 269
 270 /* No procedure error reply */
 271 void
 272 svcerr_noproc (register SVCXPRT *xprt)
 273 {
 274   struct rpc_msg rply;
 275
 276   rply.rm_direction = REPLY;
 277   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 278   rply.acpted_rply.ar_verf = xprt->xp_verf;
 279   rply.acpted_rply.ar_stat = PROC_UNAVAIL;
 280   SVC_REPLY (xprt, &rply);
 281 }
 282 #ifdef EXPORT_RPC_SYMBOLS
 283 libc_hidden_def (svcerr_noproc)
 284 #else
 285 libc_hidden_nolink_sunrpc (svcerr_noproc, GLIBC_2_0)
 286 #endif
 287
 288 /* Can't decode args error reply */
 289 void
 290 svcerr_decode (register SVCXPRT *xprt)
 291 {
 292   struct rpc_msg rply;
 293
 294   rply.rm_direction = REPLY;
 295   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 296   rply.acpted_rply.ar_verf = xprt->xp_verf;
 297   rply.acpted_rply.ar_stat = GARBAGE_ARGS;
 298   SVC_REPLY (xprt, &rply);
 299 }
 300 #ifdef EXPORT_RPC_SYMBOLS
 301 libc_hidden_def (svcerr_decode)
 302 #else
 303 libc_hidden_nolink_sunrpc (svcerr_decode, GLIBC_2_0)
 304 #endif
 305
 306 /* Some system error */
 307 void
 308 svcerr_systemerr (register SVCXPRT *xprt)
 309 {
 310   struct rpc_msg rply;
 311
 312   rply.rm_direction = REPLY;
 313   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 314   rply.acpted_rply.ar_verf = xprt->xp_verf;
 315   rply.acpted_rply.ar_stat = SYSTEM_ERR;
 316   SVC_REPLY (xprt, &rply);
 317 }
 318 #ifdef EXPORT_RPC_SYMBOLS
 319 libc_hidden_def (svcerr_systemerr)
 320 #else
 321 libc_hidden_nolink_sunrpc (svcerr_systemerr, GLIBC_2_0)
 322 #endif
 323
 324 /* Authentication error reply */
 325 void
 326 svcerr_auth (SVCXPRT *xprt, enum auth_stat why)
 327 {
 328   struct rpc_msg rply;
 329
 330   rply.rm_direction = REPLY;
 331   rply.rm_reply.rp_stat = MSG_DENIED;
 332   rply.rjcted_rply.rj_stat = AUTH_ERROR;
 333   rply.rjcted_rply.rj_why = why;
 334   SVC_REPLY (xprt, &rply);
 335 }
 336 libc_hidden_nolink_sunrpc (svcerr_auth, GLIBC_2_0)
 337
 338 /* Auth too weak error reply */
 339 void
 340 svcerr_weakauth (SVCXPRT *xprt)
 341 {
 342   svcerr_auth (xprt, AUTH_TOOWEAK);
 343 }
 344 libc_hidden_nolink_sunrpc (svcerr_weakauth, GLIBC_2_0)
 345
 346 /* Program unavailable error reply */
 347 void
 348 svcerr_noprog (register SVCXPRT *xprt)
 349 {
 350   struct rpc_msg rply;
 351
 352   rply.rm_direction = REPLY;
 353   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 354   rply.acpted_rply.ar_verf = xprt->xp_verf;
 355   rply.acpted_rply.ar_stat = PROG_UNAVAIL;
 356   SVC_REPLY (xprt, &rply);
 357 }
 358 libc_hidden_nolink_sunrpc (svcerr_noprog, GLIBC_2_0)
 359
 360 /* Program version mismatch error reply */
 361 void
 362 svcerr_progvers (register SVCXPRT *xprt, rpcvers_t low_vers,
 363                  rpcvers_t high_vers)
 364 {
 365   struct rpc_msg rply;
 366
 367   rply.rm_direction = REPLY;
 368   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 369   rply.acpted_rply.ar_verf = xprt->xp_verf;
 370   rply.acpted_rply.ar_stat = PROG_MISMATCH;
 371   rply.acpted_rply.ar_vers.low = low_vers;
 372   rply.acpted_rply.ar_vers.high = high_vers;
 373   SVC_REPLY (xprt, &rply);
 374 }
 375 libc_hidden_nolink_sunrpc (svcerr_progvers, GLIBC_2_0)
 376
 377 /* ******************* SERVER INPUT STUFF ******************* */
 378
 379 /*
 380  * Get server side input from some transport.
 381  *
 382  * Statement of authentication parameters management:
 383  * This function owns and manages all authentication parameters, specifically
 384  * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
 385  * the "cooked" credentials (rqst->rq_clntcred).
 386  * However, this function does not know the structure of the cooked
 387  * credentials, so it make the following assumptions:
 388  *   a) the structure is contiguous (no pointers), and
 389  *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
 390  * In all events, all three parameters are freed upon exit from this routine.
 391  * The storage is trivially management on the call stack in user land, but
 392  * is mallocated in kernel land.
 393  */
 394
 395 void
 396 svc_getreq (int rdfds)
 397 {
 398   fd_set readfds;
 399
 400   FD_ZERO (&readfds);
 401   readfds.fds_bits[0] = rdfds;
 402   svc_getreqset (&readfds);
 403 }
 404 libc_hidden_nolink_sunrpc (svc_getreq, GLIBC_2_0)
 405
 406 void
 407 svc_getreqset (fd_set *readfds)
 408 {
 409   register fd_mask mask;
 410   register fd_mask *maskp;
 411   register int setsize;
 412   register int sock;
 413   register int bit;
 414
 415   setsize = _rpc_dtablesize ();
 416   if (setsize > FD_SETSIZE)
 417     setsize = FD_SETSIZE;
 418   maskp = readfds->fds_bits;
 419   for (sock = 0; sock < setsize; sock += NFDBITS)
 420     for (mask = *maskp++; (bit = ffsl (mask)); mask ^= (1L << (bit - 1)))
 421       svc_getreq_common (sock + bit - 1);
 422 }
 423 libc_hidden_nolink_sunrpc (svc_getreqset, GLIBC_2_0)
 424
 425 void
 426 svc_getreq_poll (struct pollfd *pfdp, int pollretval)
 427 {
 428   if (pollretval == 0)
 429     return;
 430
 431   register int fds_found;
 432   for (int i = fds_found = 0; i < svc_max_pollfd; ++i)
 433     {
 434       register struct pollfd *p = &pfdp[i];
 435
 436       if (p->fd != -1 && p->revents)
 437         {
 438           /* fd has input waiting */
 439           if (p->revents & POLLNVAL)
 440             xprt_unregister (xports[p->fd]);
 441           else
 442             svc_getreq_common (p->fd);
 443
 444           if (++fds_found >= pollretval)
 445             break;
 446         }
 447     }
 448 }
 449 #ifdef EXPORT_RPC_SYMBOLS
 450 libc_hidden_def (svc_getreq_poll)
 451 #else
 452 libc_hidden_nolink_sunrpc (svc_getreq_poll, GLIBC_2_2)
 453 #endif
 454
 455
 456 void
 457 svc_getreq_common (const int fd)
 458 {
 459   enum xprt_stat stat;
 460   struct rpc_msg msg;
 461   register SVCXPRT *xprt;
 462   char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
 463   msg.rm_call.cb_cred.oa_base = cred_area;
 464   msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
 465
 466   xprt = xports[fd];
 467   /* Do we control fd? */
 468   if (xprt == NULL)
 469      return;
 470
 471   /* now receive msgs from xprtprt (support batch calls) */
 472   do
 473     {
 474       if (SVC_RECV (xprt, &msg))
 475         {
 476           /* now find the exported program and call it */
 477           struct svc_callout *s;
 478           struct svc_req r;
 479           enum auth_stat why;
 480           rpcvers_t low_vers;
 481           rpcvers_t high_vers;
 482           int prog_found;
 483
 484           r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);
 485           r.rq_xprt = xprt;
 486           r.rq_prog = msg.rm_call.cb_prog;
 487           r.rq_vers = msg.rm_call.cb_vers;
 488           r.rq_proc = msg.rm_call.cb_proc;
 489           r.rq_cred = msg.rm_call.cb_cred;
 490
 491           /* first authenticate the message */
 492           /* Check for null flavor and bypass these calls if possible */
 493
 494           if (msg.rm_call.cb_cred.oa_flavor == AUTH_NULL)
 495             {
 496               r.rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
 497               r.rq_xprt->xp_verf.oa_length = 0;
 498             }
 499           else if ((why = _authenticate (&r, &msg)) != AUTH_OK)
 500             {
 501               svcerr_auth (xprt, why);
 502               goto call_done;
 503             }
 504
 505           /* now match message with a registered service */
 506           prog_found = FALSE;
 507           low_vers = 0 - 1;
 508           high_vers = 0;
 509
 510           for (s = svc_head; s != NULL_SVC; s = s->sc_next)
 511             {
 512               if (s->sc_prog == r.rq_prog)
 513                 {
 514                   if (s->sc_vers == r.rq_vers)
 515                     {
 516                       (*s->sc_dispatch) (&r, xprt);
 517                       goto call_done;
 518                     }
 519                   /* found correct version */
 520                   prog_found = TRUE;
 521                   if (s->sc_vers < low_vers)
 522                     low_vers = s->sc_vers;
 523                   if (s->sc_vers > high_vers)
 524                     high_vers = s->sc_vers;
 525                 }
 526               /* found correct program */
 527             }
 528           /* if we got here, the program or version
 529              is not served ... */
 530           if (prog_found)
 531             svcerr_progvers (xprt, low_vers, high_vers);
 532           else
 533             svcerr_noprog (xprt);
 534           /* Fall through to ... */
 535         }
 536     call_done:
 537       if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
 538         {
 539           SVC_DESTROY (xprt);
 540           break;
 541         }
 542     }
 543   while (stat == XPRT_MOREREQS);
 544 }
 545 libc_hidden_nolink_sunrpc (svc_getreq_common, GLIBC_2_2)
 546
 547 #ifdef _RPC_THREAD_SAFE_
 548
 549 void
 550 __rpc_thread_svc_cleanup (void)
 551 {
 552   struct svc_callout *svcp;
 553
 554   while ((svcp = svc_head) != NULL)
 555     svc_unregister (svcp->sc_prog, svcp->sc_vers);
 556 }
 557
 558 #endif /* _RPC_THREAD_SAFE_ */