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) 1984, Sun Microsystems, 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 Sun Microsystems, 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_def (xprt_register)
 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 libc_hidden_def (xprt_unregister)
 140
 141
 142 /* ********************** CALLOUT list related stuff ************* */
 143
 144 /* Search the callout list for a program number, return the callout
 145    struct. */
 146 static struct svc_callout *
 147 svc_find (rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev)
 148 {
 149   register struct svc_callout *s, *p;
 150
 151   p = NULL_SVC;
 152   for (s = svc_head; s != NULL_SVC; s = s->sc_next)
 153     {
 154       if ((s->sc_prog == prog) && (s->sc_vers == vers))
 155         goto done;
 156       p = s;
 157     }
 158 done:
 159   *prev = p;
 160   return s;
 161 }
 162
 163
 164 static bool_t
 165 svc_is_mapped (rpcprog_t prog, rpcvers_t vers)
 166 {
 167   struct svc_callout *prev;
 168   register struct svc_callout *s;
 169   s = svc_find (prog, vers, &prev);
 170   return s!= NULL_SVC && s->sc_mapped;
 171 }
 172
 173
 174 /* Add a service program to the callout list.
 175    The dispatch routine will be called when a rpc request for this
 176    program number comes in. */
 177 bool_t
 178 svc_register (SVCXPRT * xprt, rpcprog_t prog, rpcvers_t vers,
 179               void (*dispatch) (struct svc_req *, SVCXPRT *),
 180               rpcproc_t protocol)
 181 {
 182   struct svc_callout *prev;
 183   register struct svc_callout *s;
 184
 185   if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
 186     {
 187       if (s->sc_dispatch == dispatch)
 188         goto pmap_it;           /* he is registering another xptr */
 189       return FALSE;
 190     }
 191   s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
 192   if (s == (struct svc_callout *) 0)
 193     return FALSE;
 194
 195   s->sc_prog = prog;
 196   s->sc_vers = vers;
 197   s->sc_dispatch = dispatch;
 198   s->sc_next = svc_head;
 199   s->sc_mapped = FALSE;
 200   svc_head = s;
 201
 202 pmap_it:
 203   /* now register the information with the local binder service */
 204   if (protocol)
 205     {
 206       if (! pmap_set (prog, vers, protocol, xprt->xp_port))
 207         return FALSE;
 208
 209       s->sc_mapped = TRUE;
 210     }
 211
 212   return TRUE;
 213 }
 214 libc_hidden_def (svc_register)
 215
 216 /* Remove a service program from the callout list. */
 217 void
 218 svc_unregister (rpcprog_t prog, rpcvers_t vers)
 219 {
 220   struct svc_callout *prev;
 221   register struct svc_callout *s;
 222
 223   if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
 224     return;
 225
 226   if (prev == NULL_SVC)
 227     svc_head = s->sc_next;
 228   else
 229     prev->sc_next = s->sc_next;
 230
 231   s->sc_next = NULL_SVC;
 232   mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
 233   /* now unregister the information with the local binder service */
 234   if (! svc_is_mapped (prog, vers))
 235     pmap_unset (prog, vers);
 236 }
 237 libc_hidden_def (svc_unregister)
 238
 239 /* ******************* REPLY GENERATION ROUTINES  ************ */
 240
 241 /* Send a reply to an rpc request */
 242 bool_t
 243 svc_sendreply (register SVCXPRT *xprt, xdrproc_t xdr_results,
 244                caddr_t xdr_location)
 245 {
 246   struct rpc_msg rply;
 247
 248   rply.rm_direction = REPLY;
 249   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 250   rply.acpted_rply.ar_verf = xprt->xp_verf;
 251   rply.acpted_rply.ar_stat = SUCCESS;
 252   rply.acpted_rply.ar_results.where = xdr_location;
 253   rply.acpted_rply.ar_results.proc = xdr_results;
 254   return SVC_REPLY (xprt, &rply);
 255 }
 256 INTDEF (svc_sendreply)
 257
 258 /* No procedure error reply */
 259 void
 260 svcerr_noproc (register SVCXPRT *xprt)
 261 {
 262   struct rpc_msg rply;
 263
 264   rply.rm_direction = REPLY;
 265   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 266   rply.acpted_rply.ar_verf = xprt->xp_verf;
 267   rply.acpted_rply.ar_stat = PROC_UNAVAIL;
 268   SVC_REPLY (xprt, &rply);
 269 }
 270
 271 /* Can't decode args error reply */
 272 void
 273 svcerr_decode (register SVCXPRT *xprt)
 274 {
 275   struct rpc_msg rply;
 276
 277   rply.rm_direction = REPLY;
 278   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 279   rply.acpted_rply.ar_verf = xprt->xp_verf;
 280   rply.acpted_rply.ar_stat = GARBAGE_ARGS;
 281   SVC_REPLY (xprt, &rply);
 282 }
 283 INTDEF (svcerr_decode)
 284
 285 /* Some system error */
 286 void
 287 svcerr_systemerr (register SVCXPRT *xprt)
 288 {
 289   struct rpc_msg rply;
 290
 291   rply.rm_direction = REPLY;
 292   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 293   rply.acpted_rply.ar_verf = xprt->xp_verf;
 294   rply.acpted_rply.ar_stat = SYSTEM_ERR;
 295   SVC_REPLY (xprt, &rply);
 296 }
 297
 298 /* Authentication error reply */
 299 void
 300 svcerr_auth (SVCXPRT *xprt, enum auth_stat why)
 301 {
 302   struct rpc_msg rply;
 303
 304   rply.rm_direction = REPLY;
 305   rply.rm_reply.rp_stat = MSG_DENIED;
 306   rply.rjcted_rply.rj_stat = AUTH_ERROR;
 307   rply.rjcted_rply.rj_why = why;
 308   SVC_REPLY (xprt, &rply);
 309 }
 310 libc_hidden_def (svcerr_auth)
 311
 312 /* Auth too weak error reply */
 313 void
 314 svcerr_weakauth (SVCXPRT *xprt)
 315 {
 316   svcerr_auth (xprt, AUTH_TOOWEAK);
 317 }
 318
 319 /* Program unavailable error reply */
 320 void
 321 svcerr_noprog (register SVCXPRT *xprt)
 322 {
 323   struct rpc_msg rply;
 324
 325   rply.rm_direction = REPLY;
 326   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 327   rply.acpted_rply.ar_verf = xprt->xp_verf;
 328   rply.acpted_rply.ar_stat = PROG_UNAVAIL;
 329   SVC_REPLY (xprt, &rply);
 330 }
 331 libc_hidden_def (svcerr_noprog)
 332
 333 /* Program version mismatch error reply */
 334 void
 335 svcerr_progvers (register SVCXPRT *xprt, rpcvers_t low_vers,
 336                  rpcvers_t high_vers)
 337 {
 338   struct rpc_msg rply;
 339
 340   rply.rm_direction = REPLY;
 341   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 342   rply.acpted_rply.ar_verf = xprt->xp_verf;
 343   rply.acpted_rply.ar_stat = PROG_MISMATCH;
 344   rply.acpted_rply.ar_vers.low = low_vers;
 345   rply.acpted_rply.ar_vers.high = high_vers;
 346   SVC_REPLY (xprt, &rply);
 347 }
 348 libc_hidden_def (svcerr_progvers)
 349
 350 /* ******************* SERVER INPUT STUFF ******************* */
 351
 352 /*
 353  * Get server side input from some transport.
 354  *
 355  * Statement of authentication parameters management:
 356  * This function owns and manages all authentication parameters, specifically
 357  * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
 358  * the "cooked" credentials (rqst->rq_clntcred).
 359  * However, this function does not know the structure of the cooked
 360  * credentials, so it make the following assumptions:
 361  *   a) the structure is contiguous (no pointers), and
 362  *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
 363  * In all events, all three parameters are freed upon exit from this routine.
 364  * The storage is trivially management on the call stack in user land, but
 365  * is mallocated in kernel land.
 366  */
 367
 368 void
 369 svc_getreq (int rdfds)
 370 {
 371   fd_set readfds;
 372
 373   FD_ZERO (&readfds);
 374   readfds.fds_bits[0] = rdfds;
 375   INTUSE(svc_getreqset) (&readfds);
 376 }
 377 INTDEF (svc_getreq)
 378
 379 void
 380 svc_getreqset (fd_set *readfds)
 381 {
 382   register fd_mask mask;
 383   register fd_mask *maskp;
 384   register int setsize;
 385   register int sock;
 386   register int bit;
 387
 388   setsize = _rpc_dtablesize ();
 389   if (setsize > FD_SETSIZE)
 390     setsize = FD_SETSIZE;
 391   maskp = readfds->fds_bits;
 392   for (sock = 0; sock < setsize; sock += NFDBITS)
 393     for (mask = *maskp++; (bit = ffsl (mask)); mask ^= (1L << (bit - 1)))
 394       INTUSE(svc_getreq_common) (sock + bit - 1);
 395 }
 396 INTDEF (svc_getreqset)
 397
 398 void
 399 svc_getreq_poll (struct pollfd *pfdp, int pollretval)
 400 {
 401   if (pollretval == 0)
 402     return;
 403
 404   register int fds_found;
 405   for (int i = fds_found = 0; i < svc_max_pollfd; ++i)
 406     {
 407       register struct pollfd *p = &pfdp[i];
 408
 409       if (p->fd != -1 && p->revents)
 410         {
 411           /* fd has input waiting */
 412           if (p->revents & POLLNVAL)
 413             xprt_unregister (xports[p->fd]);
 414           else
 415             INTUSE(svc_getreq_common) (p->fd);
 416
 417           if (++fds_found >= pollretval)
 418             break;
 419         }
 420     }
 421 }
 422 INTDEF (svc_getreq_poll)
 423
 424
 425 void
 426 svc_getreq_common (const int fd)
 427 {
 428   enum xprt_stat stat;
 429   struct rpc_msg msg;
 430   register SVCXPRT *xprt;
 431   char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
 432   msg.rm_call.cb_cred.oa_base = cred_area;
 433   msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
 434
 435   xprt = xports[fd];
 436   /* Do we control fd? */
 437   if (xprt == NULL)
 438      return;
 439
 440   /* now receive msgs from xprtprt (support batch calls) */
 441   do
 442     {
 443       if (SVC_RECV (xprt, &msg))
 444         {
 445           /* now find the exported program and call it */
 446           struct svc_callout *s;
 447           struct svc_req r;
 448           enum auth_stat why;
 449           rpcvers_t low_vers;
 450           rpcvers_t high_vers;
 451           int prog_found;
 452
 453           r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);
 454           r.rq_xprt = xprt;
 455           r.rq_prog = msg.rm_call.cb_prog;
 456           r.rq_vers = msg.rm_call.cb_vers;
 457           r.rq_proc = msg.rm_call.cb_proc;
 458           r.rq_cred = msg.rm_call.cb_cred;
 459
 460           /* first authenticate the message */
 461           /* Check for null flavor and bypass these calls if possible */
 462
 463           if (msg.rm_call.cb_cred.oa_flavor == AUTH_NULL)
 464             {
 465               r.rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
 466               r.rq_xprt->xp_verf.oa_length = 0;
 467             }
 468           else if ((why = INTUSE(_authenticate) (&r, &msg)) != AUTH_OK)
 469             {
 470               svcerr_auth (xprt, why);
 471               goto call_done;
 472             }
 473
 474           /* now match message with a registered service */
 475           prog_found = FALSE;
 476           low_vers = 0 - 1;
 477           high_vers = 0;
 478
 479           for (s = svc_head; s != NULL_SVC; s = s->sc_next)
 480             {
 481               if (s->sc_prog == r.rq_prog)
 482                 {
 483                   if (s->sc_vers == r.rq_vers)
 484                     {
 485                       (*s->sc_dispatch) (&r, xprt);
 486                       goto call_done;
 487                     }
 488                   /* found correct version */
 489                   prog_found = TRUE;
 490                   if (s->sc_vers < low_vers)
 491                     low_vers = s->sc_vers;
 492                   if (s->sc_vers > high_vers)
 493                     high_vers = s->sc_vers;
 494                 }
 495               /* found correct program */
 496             }
 497           /* if we got here, the program or version
 498              is not served ... */
 499           if (prog_found)
 500             svcerr_progvers (xprt, low_vers, high_vers);
 501           else
 502             svcerr_noprog (xprt);
 503           /* Fall through to ... */
 504         }
 505     call_done:
 506       if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
 507         {
 508           SVC_DESTROY (xprt);
 509           break;
 510         }
 511     }
 512   while (stat == XPRT_MOREREQS);
 513 }
 514 INTDEF (svc_getreq_common)
 515
 516 #ifdef _RPC_THREAD_SAFE_
 517
 518 void
 519 __rpc_thread_svc_cleanup (void)
 520 {
 521   struct svc_callout *svcp;
 522
 523   while ((svcp = svc_head) != NULL)
 524     svc_unregister (svcp->sc_prog, svcp->sc_vers);
 525 }
 526
 527 #endif /* _RPC_THREAD_SAFE_ */