sunrpc/svc.c

   1 /*
   2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   3  * unrestricted use provided that this legend is included on all tape
   4  * media and as a part of the software program in whole or part.  Users
   5  * may copy or modify Sun RPC without charge, but are not authorized
   6  * to license or distribute it to anyone else except as part of a product or
   7  * program developed by the user.
   8  *
   9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  12  *
  13  * Sun RPC is provided with no support and without any obligation on the
  14  * part of Sun Microsystems, Inc. to assist in its use, correction,
  15  * modification or enhancement.
  16  *
  17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  19  * OR ANY PART THEREOF.
  20  *
  21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  22  * or profits or other special, indirect and consequential damages, even if
  23  * Sun has been advised of the possibility of such damages.
  24  *
  25  * Sun Microsystems, Inc.
  26  * 2550 Garcia Avenue
  27  * Mountain View, California  94043
  28  */
  29 /*
  30  * svc.c, Server-side remote procedure call interface.
  31  *
  32  * There are two sets of procedures here.  The xprt routines are
  33  * for handling transport handles.  The svc routines handle the
  34  * list of service routines.
  35  *
  36  * Copyright (C) 1984, Sun Microsystems, Inc.
  37  */
  38
  39 #include <errno.h>
  40 #include <unistd.h>
  41 #include <rpc/rpc.h>
  42 #include <rpc/svc.h>
  43 #include <rpc/pmap_clnt.h>
  44 #include <sys/poll.h>
  45
  46 #ifdef _RPC_THREAD_SAFE_
  47 #define xports ((SVCXPRT **)RPC_THREAD_VARIABLE(svc_xports_s))
  48 #else
  49 static SVCXPRT **xports;
  50 #endif
  51
  52 #define NULL_SVC ((struct svc_callout *)0)
  53 #define RQCRED_SIZE     400     /* this size is excessive */
  54
  55 /* The services list
  56    Each entry represents a set of procedures (an rpc program).
  57    The dispatch routine takes request structs and runs the
  58    appropriate procedure. */
  59 struct svc_callout {
  60   struct svc_callout *sc_next;
  61   rpcprog_t sc_prog;
  62   rpcvers_t sc_vers;
  63   void (*sc_dispatch) (struct svc_req *, SVCXPRT *);
  64 };
  65 #ifdef _RPC_THREAD_SAFE_
  66 #define svc_head ((struct svc_callout *)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       xports[sock] = xprt;
  90       if (sock < FD_SETSIZE)
  91         FD_SET (sock, &svc_fdset);
  92
  93       /* Check if we have an empty slot */
  94       for (i = 0; i < svc_max_pollfd; ++i)
  95         if (svc_pollfd[i].fd == -1)
  96           {
  97             svc_pollfd[i].fd = sock;
  98             svc_pollfd[i].events = (POLLIN | POLLPRI |
  99                                     POLLRDNORM | POLLRDBAND);
 100             return;
 101           }
 102
 103       ++svc_max_pollfd;
 104       svc_pollfd = realloc (svc_pollfd,
 105                             sizeof (struct pollfd) * svc_max_pollfd);
 106       if (svc_pollfd == NULL) /* Out of memory */
 107         return;
 108
 109       svc_pollfd[svc_max_pollfd - 1].fd = sock;
 110       svc_pollfd[svc_max_pollfd - 1].events = (POLLIN | POLLPRI |
 111                                                POLLRDNORM | POLLRDBAND);
 112     }
 113 }
 114
 115 /* De-activate a transport handle. */
 116 void
 117 xprt_unregister (SVCXPRT *xprt)
 118 {
 119   register int sock = xprt->xp_sock;
 120   register int i;
 121
 122   if ((sock < _rpc_dtablesize ()) && (xports[sock] == xprt))
 123     {
 124       xports[sock] = (SVCXPRT *) 0;
 125
 126       if (sock < FD_SETSIZE)
 127         FD_CLR (sock, &svc_fdset);
 128
 129       for (i = 0; i < svc_max_pollfd; ++i)
 130         if (svc_pollfd[i].fd == sock)
 131           svc_pollfd[i].fd = -1;
 132     }
 133 }
 134
 135
 136 /* ********************** CALLOUT list related stuff ************* */
 137
 138 /* Search the callout list for a program number, return the callout
 139    struct. */
 140 static struct svc_callout *
 141 svc_find (rpcprog_t prog, rpcvers_t vers, struct svc_callout **prev)
 142 {
 143   register struct svc_callout *s, *p;
 144
 145   p = NULL_SVC;
 146   for (s = svc_head; s != NULL_SVC; s = s->sc_next)
 147     {
 148       if ((s->sc_prog == prog) && (s->sc_vers == vers))
 149         goto done;
 150       p = s;
 151     }
 152 done:
 153   *prev = p;
 154   return s;
 155 }
 156
 157 /* Add a service program to the callout list.
 158    The dispatch routine will be called when a rpc request for this
 159    program number comes in. */
 160 bool_t
 161 svc_register (SVCXPRT * xprt, rpcprog_t prog, rpcvers_t vers,
 162               void (*dispatch) (struct svc_req *, SVCXPRT *),
 163               rpcproc_t protocol)
 164 {
 165   struct svc_callout *prev;
 166   register struct svc_callout *s;
 167
 168   if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
 169     {
 170       if (s->sc_dispatch == dispatch)
 171         goto pmap_it;           /* he is registering another xptr */
 172       return FALSE;
 173     }
 174   s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
 175   if (s == (struct svc_callout *) 0)
 176     return FALSE;
 177
 178   s->sc_prog = prog;
 179   s->sc_vers = vers;
 180   s->sc_dispatch = dispatch;
 181   s->sc_next = svc_head;
 182   svc_head = s;
 183
 184 pmap_it:
 185   /* now register the information with the local binder service */
 186   if (protocol)
 187     return pmap_set (prog, vers, protocol, xprt->xp_port);
 188
 189   return TRUE;
 190 }
 191
 192 /* Remove a service program from the callout list. */
 193 void
 194 svc_unregister (rpcprog_t prog, rpcvers_t vers)
 195 {
 196   struct svc_callout *prev;
 197   register struct svc_callout *s;
 198
 199   if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
 200     return;
 201
 202   if (prev == NULL_SVC)
 203     svc_head = s->sc_next;
 204   else
 205     prev->sc_next = s->sc_next;
 206
 207   s->sc_next = NULL_SVC;
 208   mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
 209   /* now unregister the information with the local binder service */
 210   pmap_unset (prog, vers);
 211 }
 212
 213 /* ******************* REPLY GENERATION ROUTINES  ************ */
 214
 215 /* Send a reply to an rpc request */
 216 bool_t
 217 svc_sendreply (register SVCXPRT *xprt, xdrproc_t xdr_results,
 218                caddr_t xdr_location)
 219 {
 220   struct rpc_msg rply;
 221
 222   rply.rm_direction = REPLY;
 223   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 224   rply.acpted_rply.ar_verf = xprt->xp_verf;
 225   rply.acpted_rply.ar_stat = SUCCESS;
 226   rply.acpted_rply.ar_results.where = xdr_location;
 227   rply.acpted_rply.ar_results.proc = xdr_results;
 228   return SVC_REPLY (xprt, &rply);
 229 }
 230
 231 /* No procedure error reply */
 232 void
 233 svcerr_noproc (register SVCXPRT *xprt)
 234 {
 235   struct rpc_msg rply;
 236
 237   rply.rm_direction = REPLY;
 238   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 239   rply.acpted_rply.ar_verf = xprt->xp_verf;
 240   rply.acpted_rply.ar_stat = PROC_UNAVAIL;
 241   SVC_REPLY (xprt, &rply);
 242 }
 243
 244 /* Can't decode args error reply */
 245 void
 246 svcerr_decode (register SVCXPRT *xprt)
 247 {
 248   struct rpc_msg rply;
 249
 250   rply.rm_direction = REPLY;
 251   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 252   rply.acpted_rply.ar_verf = xprt->xp_verf;
 253   rply.acpted_rply.ar_stat = GARBAGE_ARGS;
 254   SVC_REPLY (xprt, &rply);
 255 }
 256
 257 /* Some system error */
 258 void
 259 svcerr_systemerr (register SVCXPRT *xprt)
 260 {
 261   struct rpc_msg rply;
 262
 263   rply.rm_direction = REPLY;
 264   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 265   rply.acpted_rply.ar_verf = xprt->xp_verf;
 266   rply.acpted_rply.ar_stat = SYSTEM_ERR;
 267   SVC_REPLY (xprt, &rply);
 268 }
 269
 270 /* Authentication error reply */
 271 void
 272 svcerr_auth (SVCXPRT *xprt, enum auth_stat why)
 273 {
 274   struct rpc_msg rply;
 275
 276   rply.rm_direction = REPLY;
 277   rply.rm_reply.rp_stat = MSG_DENIED;
 278   rply.rjcted_rply.rj_stat = AUTH_ERROR;
 279   rply.rjcted_rply.rj_why = why;
 280   SVC_REPLY (xprt, &rply);
 281 }
 282
 283 /* Auth too weak error reply */
 284 void
 285 svcerr_weakauth (SVCXPRT *xprt)
 286 {
 287   svcerr_auth (xprt, AUTH_TOOWEAK);
 288 }
 289
 290 /* Program unavailable error reply */
 291 void
 292 svcerr_noprog (register SVCXPRT *xprt)
 293 {
 294   struct rpc_msg rply;
 295
 296   rply.rm_direction = REPLY;
 297   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 298   rply.acpted_rply.ar_verf = xprt->xp_verf;
 299   rply.acpted_rply.ar_stat = PROG_UNAVAIL;
 300   SVC_REPLY (xprt, &rply);
 301 }
 302
 303 /* Program version mismatch error reply */
 304 void
 305 svcerr_progvers (register SVCXPRT *xprt, rpcvers_t low_vers,
 306                  rpcvers_t high_vers)
 307 {
 308   struct rpc_msg rply;
 309
 310   rply.rm_direction = REPLY;
 311   rply.rm_reply.rp_stat = MSG_ACCEPTED;
 312   rply.acpted_rply.ar_verf = xprt->xp_verf;
 313   rply.acpted_rply.ar_stat = PROG_MISMATCH;
 314   rply.acpted_rply.ar_vers.low = low_vers;
 315   rply.acpted_rply.ar_vers.high = high_vers;
 316   SVC_REPLY (xprt, &rply);
 317 }
 318
 319 /* ******************* SERVER INPUT STUFF ******************* */
 320
 321 /*
 322  * Get server side input from some transport.
 323  *
 324  * Statement of authentication parameters management:
 325  * This function owns and manages all authentication parameters, specifically
 326  * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
 327  * the "cooked" credentials (rqst->rq_clntcred).
 328  * However, this function does not know the structure of the cooked
 329  * credentials, so it make the following assumptions:
 330  *   a) the structure is contiguous (no pointers), and
 331  *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
 332  * In all events, all three parameters are freed upon exit from this routine.
 333  * The storage is trivially management on the call stack in user land, but
 334  * is mallocated in kernel land.
 335  */
 336
 337 void
 338 svc_getreq (int rdfds)
 339 {
 340   fd_set readfds;
 341
 342   FD_ZERO (&readfds);
 343   readfds.fds_bits[0] = rdfds;
 344   svc_getreqset (&readfds);
 345 }
 346
 347 void
 348 svc_getreqset (fd_set *readfds)
 349 {
 350   register u_int32_t mask;
 351   register u_int32_t *maskp;
 352   register int setsize;
 353   register int sock;
 354   register int bit;
 355
 356   setsize = _rpc_dtablesize ();
 357   maskp = (u_int32_t *) readfds->fds_bits;
 358   for (sock = 0; sock < setsize; sock += 32)
 359     for (mask = *maskp++; (bit = ffs (mask)); mask ^= (1 << (bit - 1)))
 360       svc_getreq_common (sock + bit - 1);
 361 }
 362
 363 void
 364 svc_getreq_poll (struct pollfd *pfdp, int pollretval)
 365 {
 366   register int i;
 367   register int fds_found;
 368
 369   for (i = fds_found = 0; i < svc_max_pollfd && fds_found < pollretval; ++i)
 370     {
 371       register struct pollfd *p = &pfdp[i];
 372
 373       if (p->fd != -1 && p->revents)
 374         {
 375           /* fd has input waiting */
 376           ++fds_found;
 377
 378           if (p->revents & POLLNVAL)
 379             xprt_unregister (xports[p->fd]);
 380           else
 381             svc_getreq_common (p->fd);
 382         }
 383     }
 384 }
 385
 386
 387 void
 388 svc_getreq_common (const int fd)
 389 {
 390   enum xprt_stat stat;
 391   struct rpc_msg msg;
 392   register SVCXPRT *xprt;
 393   char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
 394   msg.rm_call.cb_cred.oa_base = cred_area;
 395   msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
 396
 397   xprt = xports[fd];
 398   /* Do we control fd? */
 399   if (xprt == NULL)
 400      return;
 401
 402   /* now receive msgs from xprtprt (support batch calls) */
 403   do
 404     {
 405       if (SVC_RECV (xprt, &msg))
 406         {
 407           /* now find the exported program and call it */
 408           struct svc_callout *s;
 409           struct svc_req r;
 410           enum auth_stat why;
 411           rpcvers_t low_vers;
 412           rpcvers_t high_vers;
 413           int prog_found;
 414
 415           r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);
 416           r.rq_xprt = xprt;
 417           r.rq_prog = msg.rm_call.cb_prog;
 418           r.rq_vers = msg.rm_call.cb_vers;
 419           r.rq_proc = msg.rm_call.cb_proc;
 420           r.rq_cred = msg.rm_call.cb_cred;
 421
 422           /* first authenticate the message */
 423           /* Check for null flavor and bypass these calls if possible */
 424
 425           if (msg.rm_call.cb_cred.oa_flavor == AUTH_NULL)
 426             {
 427               r.rq_xprt->xp_verf.oa_flavor = _null_auth.oa_flavor;
 428               r.rq_xprt->xp_verf.oa_length = 0;
 429             }
 430           else if ((why = _authenticate (&r, &msg)) != AUTH_OK)
 431             {
 432               svcerr_auth (xprt, why);
 433               goto call_done;
 434             }
 435
 436           /* now match message with a registered service */
 437           prog_found = FALSE;
 438           low_vers = 0 - 1;
 439           high_vers = 0;
 440
 441           for (s = svc_head; s != NULL_SVC; s = s->sc_next)
 442             {
 443               if (s->sc_prog == r.rq_prog)
 444                 {
 445                   if (s->sc_vers == r.rq_vers)
 446                     {
 447                       (*s->sc_dispatch) (&r, xprt);
 448                       goto call_done;
 449                     }
 450                   /* found correct version */
 451                   prog_found = TRUE;
 452                   if (s->sc_vers < low_vers)
 453                     low_vers = s->sc_vers;
 454                   if (s->sc_vers > high_vers)
 455                     high_vers = s->sc_vers;
 456                 }
 457               /* found correct program */
 458             }
 459           /* if we got here, the program or version
 460              is not served ... */
 461           if (prog_found)
 462             svcerr_progvers (xprt, low_vers, high_vers);
 463           else
 464             svcerr_noprog (xprt);
 465           /* Fall through to ... */
 466         }
 467     call_done:
 468       if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
 469         {
 470           SVC_DESTROY (xprt);
 471           break;
 472         }
 473     }
 474   while (stat == XPRT_MOREREQS);
 475 }
 476
 477 #ifdef _RPC_THREAD_SAFE_
 478
 479 void
 480 __rpc_thread_svc_cleanup (void)
 481 {
 482   struct svc_callout *svcp;
 483
 484   while ((svcp = svc_head) != NULL)
 485     svc_unregister (svcp->sc_prog, svcp->sc_vers);
 486 }
 487
 488 #endif /* _RPC_THREAD_SAFE_ */