lib/libc/net/rcmd.c

   1 /*
   2  * Copyright (c) 1983, 1993, 1994
   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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)rcmd.c   8.3 (Berkeley) 3/26/94
  30  * $FreeBSD: src/lib/libc/net/rcmd.c,v 1.42 2007/01/09 00:28:02 imp Exp $
  31  * $DragonFly: src/lib/libc/net/rcmd.c,v 1.7 2005/11/13 02:04:47 swildner Exp $
  32  */
  33
  34 #include "namespace.h"
  35 #include <sys/param.h>
  36 #include <sys/socket.h>
  37 #include <sys/stat.h>
  38
  39 #include <netinet/in.h>
  40 #include <arpa/inet.h>
  41
  42 #include <signal.h>
  43 #include <fcntl.h>
  44 #include <netdb.h>
  45 #include <stdlib.h>
  46 #include <unistd.h>
  47 #include <pwd.h>
  48 #include <errno.h>
  49 #include <stdio.h>
  50 #include <ctype.h>
  51 #include <string.h>
  52 #include <rpc/rpc.h>
  53 #ifdef YP
  54 #include <rpcsvc/yp_prot.h>
  55 #include <rpcsvc/ypclnt.h>
  56 #endif
  57 #include <arpa/nameser.h>
  58 #include "un-namespace.h"
  59
  60 extern int innetgr(const char *, const char *, const char *, const char *);
  61
  62 #define max(a, b)       ((a > b) ? a : b)
  63
  64 int __ivaliduser(FILE *, u_int32_t, const char *, const char *);
  65 int __ivaliduser_af(FILE *,const void *, const char *, const char *, int, int);
  66 int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t, const char *,
  67                     const char *);
  68 static int __icheckhost(const struct sockaddr *, socklen_t, const char *);
  69
  70 char paddr[NI_MAXHOST];
  71
  72 int
  73 rcmd(char **ahost, int rport, const char *locuser, const char *remuser,
  74      const char *cmd, int *fd2p)
  75 {
  76         return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
  77 }
  78
  79 int
  80 rcmd_af(char **ahost, int rport, const char *locuser, const char *remuser,
  81         const char *cmd, int *fd2p, int af)
  82 {
  83         struct addrinfo hints, *res, *ai;
  84         struct sockaddr_storage from;
  85         fd_set reads;
  86         sigset_t oldmask, newmask;
  87         pid_t pid;
  88         int s, aport, lport, timo, error;
  89         char c, *p;
  90         int refused, nres;
  91         char num[8];
  92         static char canonnamebuf[MAXDNAME];     /* is it proper here? */
  93
  94         /* call rcmdsh() with specified remote shell if appropriate. */
  95         if (!issetugid() && (p = getenv("RSH"))) {
  96                 struct servent *sp = getservbyname("shell", "tcp");
  97
  98                 if (sp && sp->s_port == rport)
  99                         return (rcmdsh(ahost, rport, locuser, remuser,
 100                             cmd, p));
 101         }
 102
 103         /* use rsh(1) if non-root and remote port is shell. */
 104         if (geteuid()) {
 105                 struct servent *sp = getservbyname("shell", "tcp");
 106
 107                 if (sp && sp->s_port == rport)
 108                         return (rcmdsh(ahost, rport, locuser, remuser,
 109                             cmd, NULL));
 110         }
 111
 112         pid = getpid();
 113
 114         memset(&hints, 0, sizeof(hints));
 115         hints.ai_flags = AI_CANONNAME;
 116         hints.ai_family = af;
 117         hints.ai_socktype = SOCK_STREAM;
 118         hints.ai_protocol = 0;
 119         snprintf(num, sizeof(num), "%d", ntohs(rport));
 120         error = getaddrinfo(*ahost, num, &hints, &res);
 121         if (error) {
 122                 fprintf(stderr, "rcmd: getaddrinfo: %s\n",
 123                         gai_strerror(error));
 124                 if (error == EAI_SYSTEM)
 125                         fprintf(stderr, "rcmd: getaddrinfo: %s\n",
 126                                 strerror(errno));
 127                 return (-1);
 128         }
 129
 130         if (res->ai_canonname &&
 131             strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) {
 132                 strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf));
 133                 *ahost = canonnamebuf;
 134         }
 135         nres = 0;
 136         for (ai = res; ai; ai = ai->ai_next)
 137                 nres++;
 138         ai = res;
 139         refused = 0;
 140         sigemptyset(&newmask);
 141         sigaddset(&newmask, SIGURG);
 142         _sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask);
 143         for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
 144                 s = rresvport_af(&lport, ai->ai_family);
 145                 if (s < 0) {
 146                         if (errno != EAGAIN && ai->ai_next) {
 147                                 ai = ai->ai_next;
 148                                 continue;
 149                         }
 150                         if (errno == EAGAIN)
 151                                 fprintf(stderr,
 152                                     "rcmd: socket: All ports in use\n");
 153                         else
 154                                 fprintf(stderr, "rcmd: socket: %s\n",
 155                                     strerror(errno));
 156                         freeaddrinfo(res);
 157                         _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
 158                             NULL);
 159                         return (-1);
 160                 }
 161                 _fcntl(s, F_SETOWN, pid);
 162                 if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
 163                         break;
 164                 _close(s);
 165                 if (errno == EADDRINUSE) {
 166                         lport--;
 167                         continue;
 168                 }
 169                 if (errno == ECONNREFUSED)
 170                         refused = 1;
 171                 if (ai->ai_next == NULL && (!refused || timo > 16)) {
 172                         fprintf(stderr, "%s: %s\n", *ahost, strerror(errno));
 173                         freeaddrinfo(res);
 174                         _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
 175                             NULL);
 176                         return (-1);
 177                 }
 178                 if (nres > 1) {
 179                         int oerrno = errno;
 180
 181                         getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr,
 182                             sizeof(paddr), NULL, 0, NI_NUMERICHOST);
 183                         fprintf(stderr, "connect to address %s: ", paddr);
 184                         errno = oerrno;
 185                         perror(0);
 186                 }
 187                 if ((ai = ai->ai_next) == NULL) {
 188                         /* refused && timo <= 16 */
 189                         struct timespec time_to_sleep, time_remaining;
 190
 191                         time_to_sleep.tv_sec = timo;
 192                         time_to_sleep.tv_nsec = 0;
 193                         _nanosleep(&time_to_sleep, &time_remaining);
 194                         timo *= 2;
 195                         ai = res;
 196                         refused = 0;
 197                 }
 198                 if (nres > 1) {
 199                         getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr,
 200                             sizeof(paddr), NULL, 0, NI_NUMERICHOST);
 201                         fprintf(stderr, "Trying %s...\n", paddr);
 202                 }
 203         }
 204         lport--;
 205         if (fd2p == 0) {
 206                 _write(s, "", 1);
 207                 lport = 0;
 208         } else {
 209                 int s2 = rresvport_af(&lport, ai->ai_family), s3;
 210                 socklen_t len = ai->ai_addrlen;
 211                 int nfds;
 212
 213                 if (s2 < 0)
 214                         goto bad;
 215                 _listen(s2, 1);
 216                 snprintf(num, sizeof(num), "%d", lport);
 217                 if (_write(s, num, strlen(num)+1) != strlen(num)+1) {
 218                         fprintf(stderr,
 219                             "rcmd: write (setting up stderr): %s\n",
 220                             strerror(errno));
 221                         _close(s2);
 222                         goto bad;
 223                 }
 224                 nfds = max(s, s2)+1;
 225                 if(nfds > FD_SETSIZE) {
 226                         fprintf(stderr, "rcmd: too many files\n");
 227                         _close(s2);
 228                         goto bad;
 229                 }
 230 again:
 231                 FD_ZERO(&reads);
 232                 FD_SET(s, &reads);
 233                 FD_SET(s2, &reads);
 234                 errno = 0;
 235                 if (_select(nfds, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)){
 236                         if (errno != 0)
 237                                 fprintf(stderr,
 238                                     "rcmd: select (setting up stderr): %s\n",
 239                                     strerror(errno));
 240                         else
 241                                 fprintf(stderr,
 242                                 "select: protocol failure in circuit setup\n");
 243                         _close(s2);
 244                         goto bad;
 245                 }
 246                 s3 = _accept(s2, (struct sockaddr *)&from, &len);
 247                 switch (from.ss_family) {
 248                 case AF_INET:
 249                         aport = ntohs(((struct sockaddr_in *)&from)->sin_port);
 250                         break;
 251 #ifdef INET6
 252                 case AF_INET6:
 253                         aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port);
 254                         break;
 255 #endif
 256                 default:
 257                         aport = 0;      /* error */
 258                         break;
 259                 }
 260                 /*
 261                  * XXX careful for ftp bounce attacks. If discovered, shut them
 262                  * down and check for the real auxiliary channel to connect.
 263                  */
 264                 if (aport == 20) {
 265                         _close(s3);
 266                         goto again;
 267                 }
 268                 _close(s2);
 269                 if (s3 < 0) {
 270                         fprintf(stderr,
 271                             "rcmd: accept: %s\n", strerror(errno));
 272                         lport = 0;
 273                         goto bad;
 274                 }
 275                 *fd2p = s3;
 276                 if (aport >= IPPORT_RESERVED || aport < IPPORT_RESERVED / 2) {
 277                         fprintf(stderr,
 278                             "socket: protocol failure in circuit setup.\n");
 279                         goto bad2;
 280                 }
 281         }
 282         _write(s, locuser, strlen(locuser)+1);
 283         _write(s, remuser, strlen(remuser)+1);
 284         _write(s, cmd, strlen(cmd)+1);
 285         if (_read(s, &c, 1) != 1) {
 286                 fprintf(stderr,
 287                     "rcmd: %s: %s\n", *ahost, strerror(errno));
 288                 goto bad2;
 289         }
 290         if (c != 0) {
 291                 while (_read(s, &c, 1) == 1) {
 292                         _write(STDERR_FILENO, &c, 1);
 293                         if (c == '\n')
 294                                 break;
 295                 }
 296                 goto bad2;
 297         }
 298         _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
 299         freeaddrinfo(res);
 300         return (s);
 301 bad2:
 302         if (lport)
 303                 _close(*fd2p);
 304 bad:
 305         _close(s);
 306         _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
 307         freeaddrinfo(res);
 308         return (-1);
 309 }
 310
 311 int
 312 rresvport(int *port)
 313 {
 314         return rresvport_af(port, AF_INET);
 315 }
 316
 317 int
 318 rresvport_af(int *alport, int family)
 319 {
 320         int s;
 321         struct sockaddr_storage ss;
 322         u_short *sport;
 323
 324         memset(&ss, 0, sizeof(ss));
 325         ss.ss_family = family;
 326         switch (family) {
 327         case AF_INET:
 328                 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in);
 329                 sport = &((struct sockaddr_in *)&ss)->sin_port;
 330                 ((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY;
 331                 break;
 332 #ifdef INET6
 333         case AF_INET6:
 334                 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6);
 335                 sport = &((struct sockaddr_in6 *)&ss)->sin6_port;
 336                 ((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any;
 337                 break;
 338 #endif
 339         default:
 340                 errno = EAFNOSUPPORT;
 341                 return -1;
 342         }
 343
 344         s = _socket(ss.ss_family, SOCK_STREAM, 0);
 345         if (s < 0)
 346                 return (-1);
 347 #if 0 /* compat_exact_traditional_rresvport_semantics */
 348         sin.sin_port = htons((u_short)*alport);
 349         if (_bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
 350                 return (s);
 351         if (errno != EADDRINUSE) {
 352                 _close(s);
 353                 return (-1);
 354         }
 355 #endif
 356         *sport = 0;
 357         if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) {
 358                 _close(s);
 359                 return (-1);
 360         }
 361         *alport = (int)ntohs(*sport);
 362         return (s);
 363 }
 364
 365 int     __check_rhosts_file = 1;
 366 char    *__rcmd_errstr;
 367
 368 int
 369 ruserok(const char *rhost, int superuser, const char *ruser, const char *luser)
 370 {
 371         struct addrinfo hints, *res, *r;
 372         int error;
 373
 374         memset(&hints, 0, sizeof(hints));
 375         hints.ai_family = PF_UNSPEC;
 376         hints.ai_socktype = SOCK_DGRAM; /*dummy*/
 377         error = getaddrinfo(rhost, "0", &hints, &res);
 378         if (error)
 379                 return (-1);
 380
 381         for (r = res; r; r = r->ai_next) {
 382                 if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser,
 383                     luser) == 0) {
 384                         freeaddrinfo(res);
 385                         return (0);
 386                 }
 387         }
 388         freeaddrinfo(res);
 389         return (-1);
 390 }
 391
 392 /*
 393  * New .rhosts strategy: We are passed an ip address. We spin through
 394  * hosts.equiv and .rhosts looking for a match. When the .rhosts only
 395  * has ip addresses, we don't have to trust a nameserver.  When it
 396  * contains hostnames, we spin through the list of addresses the nameserver
 397  * gives us and look for a match.
 398  *
 399  * Returns 0 if ok, -1 if not ok.
 400  */
 401 int
 402 iruserok(unsigned long raddr, int superuser, const char *ruser,
 403          const char *luser)
 404 {
 405         struct sockaddr_in sin;
 406
 407         memset(&sin, 0, sizeof(sin));
 408         sin.sin_family = AF_INET;
 409         sin.sin_len = sizeof(struct sockaddr_in);
 410         memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
 411         return iruserok_sa((struct sockaddr *)&sin, sin.sin_len, superuser,
 412                 ruser, luser);
 413 }
 414
 415 /*
 416  * AF independent extension of iruserok.
 417  *
 418  * Returns 0 if ok, -1 if not ok.
 419  */
 420 int
 421 iruserok_sa(const void *ra, int rlen, int superuser, const char *ruser,
 422             const char *luser)
 423 {
 424         char *cp;
 425         struct stat sbuf;
 426         struct passwd *pwd;
 427         FILE *hostf;
 428         uid_t uid;
 429         int first;
 430         char pbuf[MAXPATHLEN];
 431         const struct sockaddr *raddr;
 432         struct sockaddr_storage ss;
 433
 434         /* avoid alignment issue */
 435         if (rlen > sizeof(ss))
 436                 return(-1);
 437         memcpy(&ss, ra, rlen);
 438         raddr = (struct sockaddr *)&ss;
 439
 440         first = 1;
 441         hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r");
 442 again:
 443         if (hostf) {
 444                 if (__ivaliduser_sa(hostf, raddr, rlen, luser, ruser) == 0) {
 445                         fclose(hostf);
 446                         return (0);
 447                 }
 448                 fclose(hostf);
 449         }
 450         if (first == 1 && (__check_rhosts_file || superuser)) {
 451                 first = 0;
 452                 if ((pwd = getpwnam(luser)) == NULL)
 453                         return (-1);
 454                 strcpy(pbuf, pwd->pw_dir);
 455                 strcat(pbuf, "/.rhosts");
 456
 457                 /*
 458                  * Change effective uid while opening .rhosts.  If root and
 459                  * reading an NFS mounted file system, can't read files that
 460                  * are protected read/write owner only.
 461                  */
 462                 uid = geteuid();
 463                 seteuid(pwd->pw_uid);
 464                 hostf = fopen(pbuf, "r");
 465                 seteuid(uid);
 466
 467                 if (hostf == NULL)
 468                         return (-1);
 469                 /*
 470                  * If not a regular file, or is owned by someone other than
 471                  * user or root or if writeable by anyone but the owner, quit.
 472                  */
 473                 cp = NULL;
 474                 if (lstat(pbuf, &sbuf) < 0)
 475                         cp = ".rhosts lstat failed";
 476                 else if (!S_ISREG(sbuf.st_mode))
 477                         cp = ".rhosts not regular file";
 478                 else if (_fstat(fileno(hostf), &sbuf) < 0)
 479                         cp = ".rhosts fstat failed";
 480                 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid)
 481                         cp = "bad .rhosts owner";
 482                 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH))
 483                         cp = ".rhosts writeable by other than owner";
 484                 /* If there were any problems, quit. */
 485                 if (cp) {
 486                         __rcmd_errstr = cp;
 487                         fclose(hostf);
 488                         return (-1);
 489                 }
 490                 goto again;
 491         }
 492         return (-1);
 493 }
 494
 495 /*
 496  * XXX
 497  * Don't make static, used by lpd(8).
 498  *
 499  * Returns 0 if ok, -1 if not ok.
 500  */
 501 int
 502 __ivaliduser(FILE *hostf, u_int32_t raddr, const char *luser, const char *ruser)
 503 {
 504         struct sockaddr_in sin;
 505
 506         memset(&sin, 0, sizeof(sin));
 507         sin.sin_family = AF_INET;
 508         sin.sin_len = sizeof(struct sockaddr_in);
 509         memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
 510         return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len,
 511                 luser, ruser);
 512 }
 513
 514 /*
 515  * Returns 0 if ok, -1 if not ok.
 516  *
 517  * XXX obsolete API.
 518  */
 519 int
 520 __ivaliduser_af(FILE *hostf, const void *raddr, const char *luser,
 521                 const char *ruser, int af, int len)
 522 {
 523         struct sockaddr *sa = NULL;
 524         struct sockaddr_in *sin = NULL;
 525 #ifdef INET6
 526         struct sockaddr_in6 *sin6 = NULL;
 527 #endif
 528         struct sockaddr_storage ss;
 529
 530         memset(&ss, 0, sizeof(ss));
 531         switch (af) {
 532         case AF_INET:
 533                 if (len != sizeof(sin->sin_addr))
 534                         return -1;
 535                 sin = (struct sockaddr_in *)&ss;
 536                 sin->sin_family = AF_INET;
 537                 sin->sin_len = sizeof(struct sockaddr_in);
 538                 memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr));
 539                 break;
 540 #ifdef INET6
 541         case AF_INET6:
 542                 if (len != sizeof(sin6->sin6_addr))
 543                         return -1;
 544                 /* you will lose scope info */
 545                 sin6 = (struct sockaddr_in6 *)&ss;
 546                 sin6->sin6_family = AF_INET6;
 547                 sin6->sin6_len = sizeof(struct sockaddr_in6);
 548                 memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr));
 549                 break;
 550 #endif
 551         default:
 552                 return -1;
 553         }
 554
 555         sa = (struct sockaddr *)&ss;
 556         return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser);
 557 }
 558
 559 int
 560 __ivaliduser_sa(FILE *hostf, const struct sockaddr *raddr, socklen_t salen,
 561                 const char *luser, const char *ruser)
 562 {
 563         char *user, *p;
 564         int ch;
 565         char buf[MAXHOSTNAMELEN + 128];         /* host + login */
 566         char hname[MAXHOSTNAMELEN];
 567         /* Presumed guilty until proven innocent. */
 568         int userok = 0, hostok = 0;
 569 #ifdef YP
 570         char *ypdomain;
 571
 572         if (yp_get_default_domain(&ypdomain))
 573                 ypdomain = NULL;
 574 #else
 575 #define ypdomain NULL
 576 #endif
 577         /* We need to get the damn hostname back for netgroup matching. */
 578         if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0,
 579                         NI_NAMEREQD) != 0)
 580                 hname[0] = '\0';
 581
 582         while (fgets(buf, sizeof(buf), hostf)) {
 583                 p = buf;
 584                 /* Skip lines that are too long. */
 585                 if (strchr(p, '\n') == NULL) {
 586                         while ((ch = getc(hostf)) != '\n' && ch != EOF);
 587                         continue;
 588                 }
 589                 if (*p == '\n' || *p == '#') {
 590                         /* comment... */
 591                         continue;
 592                 }
 593                 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
 594                         *p = isupper((unsigned char)*p) ? tolower((unsigned char)*p) : *p;
 595                         p++;
 596                 }
 597                 if (*p == ' ' || *p == '\t') {
 598                         *p++ = '\0';
 599                         while (*p == ' ' || *p == '\t')
 600                                 p++;
 601                         user = p;
 602                         while (*p != '\n' && *p != ' ' &&
 603                             *p != '\t' && *p != '\0')
 604                                 p++;
 605                 } else
 606                         user = p;
 607                 *p = '\0';
 608                 /*
 609                  * Do +/- and +@/-@ checking. This looks really nasty,
 610                  * but it matches SunOS's behavior so far as I can tell.
 611                  */
 612                 switch(buf[0]) {
 613                 case '+':
 614                         if (!buf[1]) {     /* '+' matches all hosts */
 615                                 hostok = 1;
 616                                 break;
 617                         }
 618                         if (buf[1] == '@')  /* match a host by netgroup */
 619                                 hostok = hname[0] != '\0' &&
 620                                     innetgr(&buf[2], hname, NULL, ypdomain);
 621                         else            /* match a host by addr */
 622                                 hostok = __icheckhost(raddr, salen,
 623                                                       (char *)&buf[1]);
 624                         break;
 625                 case '-':     /* reject '-' hosts and all their users */
 626                         if (buf[1] == '@') {
 627                                 if (hname[0] == '\0' ||
 628                                     innetgr(&buf[2], hname, NULL, ypdomain))
 629                                         return(-1);
 630                         } else {
 631                                 if (__icheckhost(raddr, salen,
 632                                                  (char *)&buf[1]))
 633                                         return(-1);
 634                         }
 635                         break;
 636                 default:  /* if no '+' or '-', do a simple match */
 637                         hostok = __icheckhost(raddr, salen, buf);
 638                         break;
 639                 }
 640                 switch(*user) {
 641                 case '+':
 642                         if (!*(user+1)) {      /* '+' matches all users */
 643                                 userok = 1;
 644                                 break;
 645                         }
 646                         if (*(user+1) == '@')  /* match a user by netgroup */
 647                                 userok = innetgr(user+2, NULL, ruser, ypdomain);
 648                         else       /* match a user by direct specification */
 649                                 userok = !(strcmp(ruser, user+1));
 650                         break;
 651                 case '-':               /* if we matched a hostname, */
 652                         if (hostok) {   /* check for user field rejections */
 653                                 if (!*(user+1))
 654                                         return(-1);
 655                                 if (*(user+1) == '@') {
 656                                         if (innetgr(user+2, NULL,
 657                                                         ruser, ypdomain))
 658                                                 return(-1);
 659                                 } else {
 660                                         if (!strcmp(ruser, user+1))
 661                                                 return(-1);
 662                                 }
 663                         }
 664                         break;
 665                 default:        /* no rejections: try to match the user */
 666                         if (hostok)
 667                                 userok = !(strcmp(ruser,*user ? user : luser));
 668                         break;
 669                 }
 670                 if (hostok && userok)
 671                         return(0);
 672         }
 673         return (-1);
 674 }
 675
 676 /*
 677  * Returns "true" if match, 0 if no match.
 678  */
 679 static int
 680 __icheckhost(const struct sockaddr *raddr, socklen_t salen, const char *lhost)
 681 {
 682         struct sockaddr_in sin;
 683         struct sockaddr_in6 *sin6;
 684         struct addrinfo hints, *res, *r;
 685         int error;
 686         char h1[NI_MAXHOST], h2[NI_MAXHOST];
 687
 688         if (raddr->sa_family == AF_INET6) {
 689                 sin6 = (struct sockaddr_in6 *)raddr;
 690                 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
 691                         memset(&sin, 0, sizeof(sin));
 692                         sin.sin_family = AF_INET;
 693                         sin.sin_len = sizeof(struct sockaddr_in);
 694                         memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12],
 695                                sizeof(sin.sin_addr));
 696                         raddr = (struct sockaddr *)&sin;
 697                         salen = sin.sin_len;
 698                 }
 699         }
 700
 701         h1[0] = '\0';
 702         if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0,
 703                         NI_NUMERICHOST) != 0)
 704                 return (0);
 705
 706         /* Resolve laddr into sockaddr */
 707         memset(&hints, 0, sizeof(hints));
 708         hints.ai_family = raddr->sa_family;
 709         hints.ai_socktype = SOCK_DGRAM; /*XXX dummy*/
 710         res = NULL;
 711         error = getaddrinfo(lhost, "0", &hints, &res);
 712         if (error)
 713                 return (0);
 714
 715         for (r = res; r ; r = r->ai_next) {
 716                 h2[0] = '\0';
 717                 if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2),
 718                                 NULL, 0, NI_NUMERICHOST) != 0)
 719                         continue;
 720                 if (strcmp(h1, h2) == 0) {
 721                         freeaddrinfo(res);
 722                         return (1);
 723                 }
 724         }
 725
 726         /* No match. */
 727         freeaddrinfo(res);
 728         return (0);
 729 }