usr.sbin/portmap/portmap.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1990, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)portmap.c        8.1 (Berkeley) 6/6/93
  35  * $FreeBSD: src/usr.sbin/portmap/portmap.c,v 1.10.2.3 2002/05/06 18:18:21 dwmalone Exp $
  36  * $DragonFly: src/usr.sbin/portmap/portmap.c,v 1.4 2004/03/30 02:58:59 cpressey Exp $
  37  */
  38
  39 /*
  40 @(#)portmap.c   2.3 88/08/11 4.0 RPCSRC
  41 static char sccsid[] = "@(#)portmap.c 1.32 87/08/06 Copyr 1984 Sun Micro";
  42 */
  43
  44 /*
  45  * portmap.c, Implements the program,version to port number mapping for
  46  * rpc.
  47  */
  48
  49 /*
  50  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
  51  * unrestricted use provided that this legend is included on all tape
  52  * media and as a part of the software program in whole or part.  Users
  53  * may copy or modify Sun RPC without charge, but are not authorized
  54  * to license or distribute it to anyone else except as part of a product or
  55  * program developed by the user.
  56  *
  57  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  58  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  59  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  60  *
  61  * Sun RPC is provided with no support and without any obligation on the
  62  * part of Sun Microsystems, Inc. to assist in its use, correction,
  63  * modification or enhancement.
  64  *
  65  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  66  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  67  * OR ANY PART THEREOF.
  68  *
  69  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  70  * or profits or other special, indirect and consequential damages, even if
  71  * Sun has been advised of the possibility of such damages.
  72  *
  73  * Sun Microsystems, Inc.
  74  * 2550 Garcia Avenue
  75  * Mountain View, California  94043
  76  */
  77
  78 #include <sys/types.h>
  79 #include <sys/socket.h>
  80 #include <sys/ioctl.h>
  81 #include <sys/wait.h>
  82 #include <sys/signal.h>
  83 #include <sys/time.h>
  84 #include <sys/resource.h>
  85 #include <rpc/rpc.h>
  86 #include <rpc/pmap_prot.h>
  87
  88 #include <err.h>
  89 #include <errno.h>
  90 #include <netdb.h>
  91 #include <stdio.h>
  92 #include <stdlib.h>
  93 #include <string.h>
  94 #include <syslog.h>
  95 #include <unistd.h>
  96
  97 #include "pmap_check.h"
  98
  99 static void reg_service(struct svc_req *, SVCXPRT *);
 100 static void reap(int);
 101 static void callit(struct svc_req *, SVCXPRT *);
 102 static void usage(void);
 103
 104 struct pmaplist *pmaplist;
 105 int debugging = 0;
 106
 107 int
 108 main(int argc, char **argv)
 109 {
 110         SVCXPRT *xprt;
 111         int sock, c;
 112         char **hosts = NULL;
 113         int nhosts = 0;
 114         struct sockaddr_in addr;
 115         int len = sizeof(struct sockaddr_in);
 116         struct pmaplist *pml;
 117
 118         while ((c = getopt(argc, argv, "dvh:")) != -1) {
 119                 switch (c) {
 120
 121                 case 'd':
 122                         debugging = 1;
 123                         break;
 124
 125                 case 'v':
 126                         verboselog = 1;
 127                         break;
 128
 129                 case 'h':
 130                         ++nhosts;
 131                         hosts = realloc(hosts, nhosts * sizeof(char *));
 132                         hosts[nhosts - 1] = optarg;
 133                         break;
 134
 135                 default:
 136                         usage();
 137                 }
 138         }
 139
 140         if (!debugging && daemon(0, 0))
 141                 err(1, "fork");
 142
 143         openlog("portmap", debugging ? LOG_PID | LOG_PERROR : LOG_PID,
 144             LOG_DAEMON);
 145
 146         bzero(&addr, sizeof(addr));
 147         addr.sin_family = AF_INET;
 148         addr.sin_port = htons(PMAPPORT);
 149
 150         /*
 151          * If no hosts were specified, just bind to INADDR_ANY.  Otherwise
 152          * make sure 127.0.0.1 is added to the list.
 153          */
 154         ++nhosts;
 155         hosts = realloc(hosts, nhosts * sizeof(char *));
 156         if (nhosts == 1)
 157                 hosts[0] = "0.0.0.0";
 158         else
 159                 hosts[nhosts - 1] = "127.0.0.1";
 160
 161         /*
 162          * Add UDP socket(s) - bind to specific IPs if asked to
 163          */
 164         while (nhosts > 0) {
 165             --nhosts;
 166
 167             if (!inet_aton(hosts[nhosts], &addr.sin_addr)) {
 168                     syslog(LOG_ERR, "bad IP address: %s", hosts[nhosts]);
 169                     exit(1);
 170             }
 171             if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
 172                     syslog(LOG_ERR, "cannot create udp socket: %m");
 173                     exit(1);
 174             }
 175
 176             if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
 177                     syslog(LOG_ERR, "cannot bind udp: %m");
 178                     exit(1);
 179             }
 180
 181             if ((xprt = svcudp_create(sock)) == (SVCXPRT *)NULL) {
 182                     syslog(LOG_ERR, "couldn't do udp_create");
 183                     exit(1);
 184             }
 185         }
 186         /* make an entry for ourself */
 187         pml = (struct pmaplist *)malloc((u_int)sizeof(struct pmaplist));
 188         pml->pml_next = 0;
 189         pml->pml_map.pm_prog = PMAPPROG;
 190         pml->pml_map.pm_vers = PMAPVERS;
 191         pml->pml_map.pm_prot = IPPROTO_UDP;
 192         pml->pml_map.pm_port = PMAPPORT;
 193         pmaplist = pml;
 194
 195         /*
 196          * Add TCP socket
 197          */
 198         addr.sin_addr.s_addr = 0;
 199         if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
 200                 syslog(LOG_ERR, "cannot create tcp socket: %m");
 201                 exit(1);
 202         }
 203         if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
 204                 syslog(LOG_ERR, "cannot bind tcp: %m");
 205                 exit(1);
 206         }
 207         if ((xprt = svctcp_create(sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE))
 208             == (SVCXPRT *)NULL) {
 209                 syslog(LOG_ERR, "couldn't do tcp_create");
 210                 exit(1);
 211         }
 212         /* make an entry for ourself */
 213         pml = (struct pmaplist *)malloc((u_int)sizeof(struct pmaplist));
 214         pml->pml_map.pm_prog = PMAPPROG;
 215         pml->pml_map.pm_vers = PMAPVERS;
 216         pml->pml_map.pm_prot = IPPROTO_TCP;
 217         pml->pml_map.pm_port = PMAPPORT;
 218         pml->pml_next = pmaplist;
 219         pmaplist = pml;
 220
 221         svc_register(xprt, PMAPPROG, PMAPVERS, reg_service, FALSE);
 222
 223         /* additional initializations */
 224         check_startup();
 225         signal(SIGCHLD, reap);
 226         svc_run();
 227         syslog(LOG_ERR, "svc_run returned unexpectedly");
 228         abort();
 229 }
 230
 231 static void
 232 usage(void)
 233 {
 234         fprintf(stderr, "usage: portmap [-dv] [-h bindip]\n");
 235         exit(1);
 236 }
 237
 238 #ifndef lint
 239 /* need to override perror calls in rpc library */
 240 void
 241 perror(const char *what)
 242 {
 243         syslog(LOG_ERR, "%s: %m", what);
 244 }
 245 #endif
 246
 247 static struct pmaplist *
 248 find_service(u_long prog, u_long vers, u_long prot)
 249 {
 250         struct pmaplist *hit = NULL;
 251         struct pmaplist *pml;
 252
 253         for (pml = pmaplist; pml != NULL; pml = pml->pml_next) {
 254                 if ((pml->pml_map.pm_prog != prog) ||
 255                         (pml->pml_map.pm_prot != prot))
 256                         continue;
 257                 hit = pml;
 258                 if (pml->pml_map.pm_vers == vers)
 259                     break;
 260         }
 261         return (hit);
 262 }
 263
 264 /*
 265  * 1 OK, 0 not
 266  */
 267 static void
 268 reg_service(struct svc_req *rqstp, SVCXPRT *xprt)
 269 {
 270         struct pmap reg;
 271         struct pmaplist *pml, *prevpml, *fnd;
 272         int ans, port;
 273         caddr_t t;
 274
 275         /*
 276          * Later wrappers change the logging severity on the fly. Reset to
 277          * defaults before handling the next request.
 278          */
 279         allow_severity = LOG_INFO;
 280         deny_severity = LOG_WARNING;
 281
 282         if (debugging)
 283                 fprintf(stderr, "server: about to do a switch\n");
 284         switch (rqstp->rq_proc) {
 285
 286         case PMAPPROC_NULL:
 287                 /*
 288                  * Null proc call
 289                  */
 290                 /* remote host authorization check */
 291                 check_default(svc_getcaller(xprt), rqstp->rq_proc, (u_long) 0);
 292                 if (!svc_sendreply(xprt, xdr_void, (caddr_t)0) && debugging) {
 293                         abort();
 294                 }
 295                 break;
 296
 297         case PMAPPROC_SET:
 298                 /*
 299                  * Set a program,version to port mapping
 300                  */
 301                 if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg))
 302                         svcerr_decode(xprt);
 303                 else {
 304                         /* reject non-local requests, protect priv. ports */
 305                         if (!check_setunset(svc_getcaller(xprt),
 306                             rqstp->rq_proc, reg.pm_prog, reg.pm_port)) {
 307                                 ans = 0;
 308                                 goto done;
 309                         }
 310                         /*
 311                          * check to see if already used
 312                          * find_service returns a hit even if
 313                          * the versions don't match, so check for it
 314                          */
 315                         fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
 316                         if (fnd && fnd->pml_map.pm_vers == reg.pm_vers) {
 317                                 if (fnd->pml_map.pm_port == reg.pm_port) {
 318                                         ans = 1;
 319                                         goto done;
 320                                 }
 321                                 else {
 322                                         ans = 0;
 323                                         goto done;
 324                                 }
 325                         } else {
 326                                 /*
 327                                  * add to END of list
 328                                  */
 329                                 pml = (struct pmaplist *)
 330                                     malloc((u_int)sizeof(struct pmaplist));
 331                                 pml->pml_map = reg;
 332                                 pml->pml_next = 0;
 333                                 if (pmaplist == 0) {
 334                                         pmaplist = pml;
 335                                 } else {
 336                                         for (fnd= pmaplist; fnd->pml_next != 0;
 337                                             fnd = fnd->pml_next);
 338                                         fnd->pml_next = pml;
 339                                 }
 340                                 ans = 1;
 341                         }
 342                 done:
 343                         if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
 344                             debugging) {
 345                                 fprintf(stderr, "svc_sendreply\n");
 346                                 abort();
 347                         }
 348                 }
 349                 break;
 350
 351         case PMAPPROC_UNSET:
 352                 /*
 353                  * Remove a program,version to port mapping.
 354                  */
 355                 if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg))
 356                         svcerr_decode(xprt);
 357                 else {
 358                         ans = 0;
 359                         /* reject non-local requests */
 360                         if (!check_setunset(svc_getcaller(xprt),
 361                             rqstp->rq_proc, reg.pm_prog, (u_long) 0))
 362                                 goto done;
 363                         for (prevpml = NULL, pml = pmaplist; pml != NULL; ) {
 364                                 if ((pml->pml_map.pm_prog != reg.pm_prog) ||
 365                                         (pml->pml_map.pm_vers != reg.pm_vers)) {
 366                                         /* both pml & prevpml move forwards */
 367                                         prevpml = pml;
 368                                         pml = pml->pml_next;
 369                                         continue;
 370                                 }
 371                                 /* found it; pml moves forward, prevpml stays */
 372                                 /* privileged port check */
 373                                 if (!check_privileged_port(svc_getcaller(xprt),
 374                                     rqstp->rq_proc,
 375                                     reg.pm_prog,
 376                                     pml->pml_map.pm_port)) {
 377                                         ans = 0;
 378                                         break;
 379                                 }
 380                                 ans = 1;
 381                                 t = (caddr_t)pml;
 382                                 pml = pml->pml_next;
 383                                 if (prevpml == NULL)
 384                                         pmaplist = pml;
 385                                 else
 386                                         prevpml->pml_next = pml;
 387                                 free(t);
 388                         }
 389                         if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
 390                             debugging) {
 391                                 fprintf(stderr, "svc_sendreply\n");
 392                                 abort();
 393                         }
 394                 }
 395                 break;
 396
 397         case PMAPPROC_GETPORT:
 398                 /*
 399                  * Lookup the mapping for a program,version and return its port
 400                  */
 401                 if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg))
 402                         svcerr_decode(xprt);
 403                 else {
 404                         /* remote host authorization check */
 405                         if (!check_default(svc_getcaller(xprt),
 406                             rqstp->rq_proc,
 407                             reg.pm_prog)) {
 408                                 ans = 0;
 409                                 goto done;
 410                         }
 411                         fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
 412                         if (fnd)
 413                                 port = fnd->pml_map.pm_port;
 414                         else
 415                                 port = 0;
 416                         if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&port)) &&
 417                             debugging) {
 418                                 fprintf(stderr, "svc_sendreply\n");
 419                                 abort();
 420                         }
 421                 }
 422                 break;
 423
 424         case PMAPPROC_DUMP:
 425                 /*
 426                  * Return the current set of mapped program,version
 427                  */
 428                 if (!svc_getargs(xprt, xdr_void, NULL))
 429                         svcerr_decode(xprt);
 430                 else {
 431                         /* remote host authorization check */
 432                         struct pmaplist *p;
 433                         if (!check_default(svc_getcaller(xprt),
 434                             rqstp->rq_proc, (u_long) 0)) {
 435                                 p = 0;  /* send empty list */
 436                         } else {
 437                                 p = pmaplist;
 438                         }
 439                         if ((!svc_sendreply(xprt, xdr_pmaplist,
 440                             (caddr_t)&p)) && debugging) {
 441                                 fprintf(stderr, "svc_sendreply\n");
 442                                 abort();
 443                         }
 444                 }
 445                 break;
 446
 447         case PMAPPROC_CALLIT:
 448                 /*
 449                  * Calls a procedure on the local machine.  If the requested
 450                  * procedure is not registered this procedure does not return
 451                  * error information!!
 452                  * This procedure is only supported on rpc/udp and calls via
 453                  * rpc/udp.  It passes null authentication parameters.
 454                  */
 455                 callit(rqstp, xprt);
 456                 break;
 457
 458         default:
 459                 /* remote host authorization check */
 460                 check_default(svc_getcaller(xprt), rqstp->rq_proc, (u_long) 0);
 461                 svcerr_noproc(xprt);
 462                 break;
 463         }
 464 }
 465
 466
 467 /*
 468  * Stuff for the rmtcall service
 469  */
 470 #define ARGSIZE 9000
 471
 472 struct encap_parms {
 473         u_int arglen;
 474         char *args;
 475 };
 476
 477 static bool_t
 478 xdr_encap_parms(XDR *xdrs, struct encap_parms *epp)
 479 {
 480         return (xdr_bytes(xdrs, &(epp->args), &(epp->arglen), ARGSIZE));
 481 }
 482
 483 struct rmtcallargs {
 484         u_long  rmt_prog;
 485         u_long  rmt_vers;
 486         u_long  rmt_port;
 487         u_long  rmt_proc;
 488         struct encap_parms rmt_args;
 489 };
 490
 491 static bool_t
 492 xdr_rmtcall_args(XDR *xdrs, struct rmtcallargs *cap)
 493 {
 494         /* does not get a port number */
 495         if (xdr_u_long(xdrs, &(cap->rmt_prog)) &&
 496             xdr_u_long(xdrs, &(cap->rmt_vers)) &&
 497             xdr_u_long(xdrs, &(cap->rmt_proc))) {
 498                 return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
 499         }
 500         return (FALSE);
 501 }
 502
 503 static bool_t
 504 xdr_rmtcall_result(XDR *xdrs, struct rmtcallargs *cap)
 505 {
 506         if (xdr_u_long(xdrs, &(cap->rmt_port)))
 507                 return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
 508         return (FALSE);
 509 }
 510
 511 /*
 512  * only worries about the struct encap_parms part of struct rmtcallargs.
 513  * The arglen must already be set!!
 514  */
 515 static bool_t
 516 xdr_opaque_parms(XDR *xdrs, struct rmtcallargs *cap)
 517 {
 518         return (xdr_opaque(xdrs, cap->rmt_args.args, cap->rmt_args.arglen));
 519 }
 520
 521 /*
 522  * This routine finds and sets the length of incoming opaque paraters
 523  * and then calls xdr_opaque_parms.
 524  */
 525 static bool_t
 526 xdr_len_opaque_parms(XDR *xdrs, struct rmtcallargs *cap)
 527 {
 528         u_int beginpos, lowpos, highpos, currpos, pos;
 529
 530         beginpos = lowpos = pos = xdr_getpos(xdrs);
 531         highpos = lowpos + ARGSIZE;
 532         while ((int)(highpos - lowpos) >= 0) {
 533                 currpos = (lowpos + highpos) / 2;
 534                 if (xdr_setpos(xdrs, currpos)) {
 535                         pos = currpos;
 536                         lowpos = currpos + 1;
 537                 } else {
 538                         highpos = currpos - 1;
 539                 }
 540         }
 541         xdr_setpos(xdrs, beginpos);
 542         cap->rmt_args.arglen = pos - beginpos;
 543         return (xdr_opaque_parms(xdrs, cap));
 544 }
 545
 546 /*
 547  * Call a remote procedure service
 548  * This procedure is very quiet when things go wrong.
 549  * The proc is written to support broadcast rpc.  In the broadcast case,
 550  * a machine should shut-up instead of complain, less the requestor be
 551  * overrun with complaints at the expense of not hearing a valid reply ...
 552  *
 553  * This now forks so that the program & process that it calls can call
 554  * back to the portmapper.
 555  */
 556 static void
 557 callit(struct svc_req *rqstp, SVCXPRT *xprt)
 558 {
 559         struct rmtcallargs a;
 560         struct pmaplist *pml;
 561         u_short port;
 562         struct sockaddr_in me;
 563         int pid, so = -1;
 564         CLIENT *client;
 565         struct authunix_parms *au = (struct authunix_parms *)rqstp->rq_clntcred;
 566         struct timeval timeout;
 567         char buf[ARGSIZE];
 568
 569         timeout.tv_sec = 5;
 570         timeout.tv_usec = 0;
 571         a.rmt_args.args = buf;
 572         if (!svc_getargs(xprt, xdr_rmtcall_args, (caddr_t)&a))
 573                 return;
 574         /* host and service access control */
 575         if (!check_callit(svc_getcaller(xprt),
 576             rqstp->rq_proc, a.rmt_prog, a.rmt_proc))
 577                 return;
 578         if ((pml = find_service(a.rmt_prog, a.rmt_vers,
 579             (u_long)IPPROTO_UDP)) == NULL)
 580                 return;
 581         /*
 582          * fork a child to do the work.  Parent immediately returns.
 583          * Child exits upon completion.
 584          */
 585         if ((pid = fork()) != 0) {
 586                 if (pid < 0)
 587                         syslog(LOG_ERR, "CALLIT (prog %lu): fork: %m",
 588                             a.rmt_prog);
 589                 return;
 590         }
 591         port = pml->pml_map.pm_port;
 592         get_myaddress(&me);
 593         me.sin_port = htons(port);
 594         client = clntudp_create(&me, a.rmt_prog, a.rmt_vers, timeout, &so);
 595         if (client != (CLIENT *)NULL) {
 596                 if (rqstp->rq_cred.oa_flavor == AUTH_UNIX) {
 597                         client->cl_auth = authunix_create(au->aup_machname,
 598                            au->aup_uid, au->aup_gid, au->aup_len, au->aup_gids);
 599                 }
 600                 a.rmt_port = (u_long)port;
 601                 if (clnt_call(client, a.rmt_proc, xdr_opaque_parms, &a,
 602                     xdr_len_opaque_parms, &a, timeout) == RPC_SUCCESS) {
 603                         svc_sendreply(xprt, xdr_rmtcall_result, (caddr_t)&a);
 604                 }
 605                 AUTH_DESTROY(client->cl_auth);
 606                 clnt_destroy(client);
 607         }
 608         close(so);
 609         exit(0);
 610 }
 611
 612 static void
 613 reap(int sig)
 614 {
 615         int save_errno;
 616
 617         save_errno = errno;
 618         while (wait3((int *)NULL, WNOHANG, (struct rusage *)NULL) > 0);
 619         errno = save_errno;
 620 }