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