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  * $FreeBSD: src/lib/libc/net/rcmd.c,v 1.23.2.7 2002/08/26 16:17:49 jdp Exp $
  30  * $DragonFly: src/lib/libc/net/rcmd.c,v 1.7 2005/11/13 02:04:47 swildner Exp $
  31  *
  32  * @(#)rcmd.c   8.3 (Berkeley) 3/26/94
  33  */
  34
  35 #include "namespace.h"
  36 #include <sys/param.h>
  37 #include <sys/socket.h>
  38 #include <sys/stat.h>
  39
  40 #include <netinet/in.h>
  41 #include <arpa/inet.h>
  42
  43 #include <signal.h>
  44 #include <fcntl.h>
  45 #include <netdb.h>
  46 #include <stdlib.h>
  47 #include <unistd.h>
  48 #include <pwd.h>
  49 #include <errno.h>
  50 #include <stdio.h>
  51 #include <ctype.h>
  52 #include <string.h>
  53 #ifdef YP
  54 #include <rpc/rpc.h>
  55 #include <rpcsvc/yp_prot.h>
  56 #include <rpcsvc/ypclnt.h>
  57 #endif
  58 #include <arpa/nameser.h>
  59 #include "un-namespace.h"
  60
  61 /* wrapper for KAME-special getnameinfo() */
  62 #ifndef NI_WITHSCOPEID
  63 #define NI_WITHSCOPEID  0
  64 #endif
  65
  66 extern int innetgr ( const char *, const char *, const char *, const char * );
  67
  68 #define max(a, b)       ((a > b) ? a : b)
  69
  70 int     __ivaliduser (FILE *, u_int32_t, const char *, const char *);
  71 int __ivaliduser_af (FILE *,const void *, const char *, const char *,
  72         int, int);
  73 int __ivaliduser_sa (FILE *, const struct sockaddr *, socklen_t,
  74         const char *,const char *);
  75 static int __icheckhost (const struct sockaddr *, socklen_t,
  76         const char *);
  77
  78 char paddr[NI_MAXHOST];
  79
  80 int
  81 rcmd(char **ahost, int rport, const char *locuser, const char *remuser,
  82      const char *cmd, int *fd2p)
  83 {
  84         return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
  85 }
  86
  87 int
  88 rcmd_af(char **ahost, int rport, const char *locuser, const char *remuser,
  89         const char *cmd, int *fd2p, int af)
  90 {
  91         struct addrinfo hints, *res, *ai;
  92         struct sockaddr_storage from;
  93         fd_set reads;
  94         sigset_t oldmask, newmask;
  95         pid_t pid;
  96         int s, aport, lport, timo, error;
  97         char c, *p;
  98         int refused, nres;
  99         char num[8];
 100         static char canonnamebuf[MAXDNAME];     /* is it proper here? */
 101
 102         /* call rcmdsh() with specified remote shell if appropriate. */
 103         if (!issetugid() && (p = getenv("RSH"))) {
 104                 struct servent *sp = getservbyname("shell", "tcp");
 105
 106                 if (sp && sp->s_port == rport)
 107                         return (rcmdsh(ahost, rport, locuser, remuser,
 108                             cmd, p));
 109         }
 110
 111         /* use rsh(1) if non-root and remote port is shell. */
 112         if (geteuid()) {
 113                 struct servent *sp = getservbyname("shell", "tcp");
 114
 115                 if (sp && sp->s_port == rport)
 116                         return (rcmdsh(ahost, rport, locuser, remuser,
 117                             cmd, NULL));
 118         }
 119
 120         pid = getpid();
 121
 122         memset(&hints, 0, sizeof(hints));
 123         hints.ai_flags = AI_CANONNAME;
 124         hints.ai_family = af;
 125         hints.ai_socktype = SOCK_STREAM;
 126         hints.ai_protocol = 0;
 127         snprintf(num, sizeof(num), "%d", ntohs(rport));
 128         error = getaddrinfo(*ahost, num, &hints, &res);
 129         if (error) {
 130                 fprintf(stderr, "rcmd: getaddrinfo: %s\n",
 131                         gai_strerror(error));
 132                 if (error == EAI_SYSTEM)
 133                         fprintf(stderr, "rcmd: getaddrinfo: %s\n",
 134                                 strerror(errno));
 135                 return (-1);
 136         }
 137
 138         if (res->ai_canonname
 139          && strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) {
 140                 strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf));
 141                 *ahost = canonnamebuf;
 142         }
 143         nres = 0;
 144         for (ai = res; ai; ai = ai->ai_next)
 145                 nres++;
 146         ai = res;
 147         refused = 0;
 148         sigemptyset(&newmask);
 149         sigaddset(&newmask, SIGURG);
 150         _sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask);
 151         for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
 152                 s = rresvport_af(&lport, ai->ai_family);
 153                 if (s < 0) {
 154                         if (errno != EAGAIN && ai->ai_next) {
 155                                 ai = ai->ai_next;
 156                                 continue;
 157                         }
 158                         if (errno == EAGAIN)
 159                                 fprintf(stderr,
 160                                     "rcmd: socket: All ports in use\n");
 161                         else
 162                                 fprintf(stderr, "rcmd: socket: %s\n",
 163                                     strerror(errno));
 164                         freeaddrinfo(res);
 165                         _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
 166                             NULL);
 167                         return (-1);
 168                 }
 169                 _fcntl(s, F_SETOWN, pid);
 170                 if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
 171                         break;
 172                 _close(s);
 173                 if (errno == EADDRINUSE) {
 174                         lport--;
 175                         continue;
 176                 }
 177                 if (errno == ECONNREFUSED)
 178                         refused = 1;
 179                 if (ai->ai_next == NULL && (!refused || timo > 16)) {
 180                         fprintf(stderr, "%s: %s\n", *ahost, strerror(errno));
 181                         freeaddrinfo(res);
 182                         _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask,
 183                             NULL);
 184                         return (-1);
 185                 }
 186                 if (nres > 1) {
 187                         int oerrno = errno;
 188
 189                         getnameinfo(ai->ai_addr, ai->ai_addrlen,
 190                                     paddr, sizeof(paddr),
 191                                     NULL, 0,
 192                                     NI_NUMERICHOST|NI_WITHSCOPEID);
 193                         fprintf(stderr, "connect to address %s: ", paddr);
 194                         errno = oerrno;
 195                         perror(0);
 196                 }
 197                 if ((ai = ai->ai_next) == NULL) {
 198                         /* refused && timo <= 16 */
 199                         struct timespec time_to_sleep, time_remaining;
 200
 201                         time_to_sleep.tv_sec = timo;
 202                         time_to_sleep.tv_nsec = 0;
 203                         _nanosleep(&time_to_sleep, &time_remaining);
 204                         timo *= 2;
 205                         ai = res;
 206                         refused = 0;
 207                 }
 208                 if (nres > 1) {
 209                         getnameinfo(ai->ai_addr, ai->ai_addrlen,
 210                                     paddr, sizeof(paddr),
 211                                     NULL, 0,
 212                                     NI_NUMERICHOST|NI_WITHSCOPEID);
 213                         fprintf(stderr, "Trying %s...\n", paddr);
 214                 }
 215         }
 216         lport--;
 217         if (fd2p == 0) {
 218                 _write(s, "", 1);
 219                 lport = 0;
 220         } else {
 221                 char num[8];
 222                 int s2 = rresvport_af(&lport, ai->ai_family), s3;
 223                 int len = ai->ai_addrlen;
 224                 int nfds;
 225
 226                 if (s2 < 0)
 227                         goto bad;
 228                 _listen(s2, 1);
 229                 snprintf(num, sizeof(num), "%d", lport);
 230                 if (_write(s, num, strlen(num)+1) != strlen(num)+1) {
 231                         fprintf(stderr,
 232                             "rcmd: write (setting up stderr): %s\n",
 233                             strerror(errno));
 234                         _close(s2);
 235                         goto bad;
 236                 }
 237                 nfds = max(s, s2)+1;
 238                 if(nfds > FD_SETSIZE) {
 239                         fprintf(stderr, "rcmd: too many files\n");
 240                         _close(s2);
 241                         goto bad;
 242                 }
 243 again:
 244                 FD_ZERO(&reads);
 245                 FD_SET(s, &reads);
 246                 FD_SET(s2, &reads);
 247                 errno = 0;
 248                 if (_select(nfds, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)){
 249                         if (errno != 0)
 250                                 fprintf(stderr,
 251                                     "rcmd: select (setting up stderr): %s\n",
 252                                     strerror(errno));
 253                         else
 254                                 fprintf(stderr,
 255                                 "select: protocol failure in circuit setup\n");
 256                         _close(s2);
 257                         goto bad;
 258                 }
 259                 s3 = _accept(s2, (struct sockaddr *)&from, &len);
 260                 switch (from.ss_family) {
 261                 case AF_INET:
 262                         aport = ntohs(((struct sockaddr_in *)&from)->sin_port);
 263                         break;
 264 #ifdef INET6
 265                 case AF_INET6:
 266                         aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port);
 267                         break;
 268 #endif
 269                 default:
 270                         aport = 0;      /* error */
 271                         break;
 272                 }
 273                 /*
 274                  * XXX careful for ftp bounce attacks. If discovered, shut them
 275                  * down and check for the real auxiliary channel to connect.
 276                  */
 277                 if (aport == 20) {
 278                         _close(s3);
 279                         goto again;
 280                 }
 281                 _close(s2);
 282                 if (s3 < 0) {
 283                         fprintf(stderr,
 284                             "rcmd: accept: %s\n", strerror(errno));
 285                         lport = 0;
 286                         goto bad;
 287                 }
 288                 *fd2p = s3;
 289                 if (aport >= IPPORT_RESERVED || aport < IPPORT_RESERVED / 2) {
 290                         fprintf(stderr,
 291                             "socket: protocol failure in circuit setup.\n");
 292                         goto bad2;
 293                 }
 294         }
 295         _write(s, locuser, strlen(locuser)+1);
 296         _write(s, remuser, strlen(remuser)+1);
 297         _write(s, cmd, strlen(cmd)+1);
 298         if (_read(s, &c, 1) != 1) {
 299                 fprintf(stderr,
 300                     "rcmd: %s: %s\n", *ahost, strerror(errno));
 301                 goto bad2;
 302         }
 303         if (c != 0) {
 304                 while (_read(s, &c, 1) == 1) {
 305                         _write(STDERR_FILENO, &c, 1);
 306                         if (c == '\n')
 307                                 break;
 308                 }
 309                 goto bad2;
 310         }
 311         _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
 312         freeaddrinfo(res);
 313         return (s);
 314 bad2:
 315         if (lport)
 316                 _close(*fd2p);
 317 bad:
 318         _close(s);
 319         _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL);
 320         freeaddrinfo(res);
 321         return (-1);
 322 }
 323
 324 int
 325 rresvport(int *port)
 326 {
 327         return rresvport_af(port, AF_INET);
 328 }
 329
 330 int
 331 rresvport_af(int *alport, int family)
 332 {
 333         int s;
 334         struct sockaddr_storage ss;
 335         u_short *sport;
 336
 337         memset(&ss, 0, sizeof(ss));
 338         ss.ss_family = family;
 339         switch (family) {
 340         case AF_INET:
 341                 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in);
 342                 sport = &((struct sockaddr_in *)&ss)->sin_port;
 343                 ((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY;
 344                 break;
 345 #ifdef INET6
 346         case AF_INET6:
 347                 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6);
 348                 sport = &((struct sockaddr_in6 *)&ss)->sin6_port;
 349                 ((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any;
 350                 break;
 351 #endif
 352         default:
 353                 errno = EAFNOSUPPORT;
 354                 return -1;
 355         }
 356
 357         s = _socket(ss.ss_family, SOCK_STREAM, 0);
 358         if (s < 0)
 359                 return (-1);
 360 #if 0 /* compat_exact_traditional_rresvport_semantics */
 361         sin.sin_port = htons((u_short)*alport);
 362         if (_bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
 363                 return (s);
 364         if (errno != EADDRINUSE) {
 365                 _close(s);
 366                 return (-1);
 367         }
 368 #endif
 369         *sport = 0;
 370         if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) {
 371                 _close(s);
 372                 return (-1);
 373         }
 374         *alport = (int)ntohs(*sport);
 375         return (s);
 376 }
 377
 378 int     __check_rhosts_file = 1;
 379 char    *__rcmd_errstr;
 380
 381 int
 382 ruserok(const char *rhost, int superuser, const char *ruser, const char *luser)
 383 {
 384         struct addrinfo hints, *res, *r;
 385         int error;
 386
 387         memset(&hints, 0, sizeof(hints));
 388         hints.ai_family = PF_UNSPEC;
 389         hints.ai_socktype = SOCK_DGRAM; /*dummy*/
 390         error = getaddrinfo(rhost, "0", &hints, &res);
 391         if (error)
 392                 return (-1);
 393
 394         for (r = res; r; r = r->ai_next) {
 395                 if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser,
 396                     luser) == 0) {
 397                         freeaddrinfo(res);
 398                         return (0);
 399                 }
 400         }
 401         freeaddrinfo(res);
 402         return (-1);
 403 }
 404
 405 /*
 406  * New .rhosts strategy: We are passed an ip address. We spin through
 407  * hosts.equiv and .rhosts looking for a match. When the .rhosts only
 408  * has ip addresses, we don't have to trust a nameserver.  When it
 409  * contains hostnames, we spin through the list of addresses the nameserver
 410  * gives us and look for a match.
 411  *
 412  * Returns 0 if ok, -1 if not ok.
 413  */
 414 int
 415 iruserok(unsigned long raddr, int superuser, const char *ruser,
 416          const char *luser)
 417 {
 418         struct sockaddr_in sin;
 419
 420         memset(&sin, 0, sizeof(sin));
 421         sin.sin_family = AF_INET;
 422         sin.sin_len = sizeof(struct sockaddr_in);
 423         memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
 424         return iruserok_sa((struct sockaddr *)&sin, sin.sin_len, superuser,
 425                 ruser, luser);
 426 }
 427
 428 /*
 429  * AF independent extension of iruserok.
 430  *
 431  * Returns 0 if ok, -1 if not ok.
 432  */
 433 int
 434 iruserok_sa(const void *ra, int rlen, int superuser, const char *ruser,
 435             const char *luser)
 436 {
 437         char *cp;
 438         struct stat sbuf;
 439         struct passwd *pwd;
 440         FILE *hostf;
 441         uid_t uid;
 442         int first;
 443         char pbuf[MAXPATHLEN];
 444         const struct sockaddr *raddr;
 445         struct sockaddr_storage ss;
 446
 447         /* avoid alignment issue */
 448         if (rlen > sizeof(ss))
 449                 return(-1);
 450         memcpy(&ss, ra, rlen);
 451         raddr = (struct sockaddr *)&ss;
 452
 453         first = 1;
 454         hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r");
 455 again:
 456         if (hostf) {
 457                 if (__ivaliduser_sa(hostf, raddr, rlen, luser, ruser) == 0) {
 458                         fclose(hostf);
 459                         return (0);
 460                 }
 461                 fclose(hostf);
 462         }
 463         if (first == 1 && (__check_rhosts_file || superuser)) {
 464                 first = 0;
 465                 if ((pwd = getpwnam(luser)) == NULL)
 466                         return (-1);
 467                 strcpy(pbuf, pwd->pw_dir);
 468                 strcat(pbuf, "/.rhosts");
 469
 470                 /*
 471                  * Change effective uid while opening .rhosts.  If root and
 472                  * reading an NFS mounted file system, can't read files that
 473                  * are protected read/write owner only.
 474                  */
 475                 uid = geteuid();
 476                 seteuid(pwd->pw_uid);
 477                 hostf = fopen(pbuf, "r");
 478                 seteuid(uid);
 479
 480                 if (hostf == NULL)
 481                         return (-1);
 482                 /*
 483                  * If not a regular file, or is owned by someone other than
 484                  * user or root or if writeable by anyone but the owner, quit.
 485                  */
 486                 cp = NULL;
 487                 if (lstat(pbuf, &sbuf) < 0)
 488                         cp = ".rhosts lstat failed";
 489                 else if (!S_ISREG(sbuf.st_mode))
 490                         cp = ".rhosts not regular file";
 491                 else if (_fstat(fileno(hostf), &sbuf) < 0)
 492                         cp = ".rhosts fstat failed";
 493                 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid)
 494                         cp = "bad .rhosts owner";
 495                 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH))
 496                         cp = ".rhosts writeable by other than owner";
 497                 /* If there were any problems, quit. */
 498                 if (cp) {
 499                         __rcmd_errstr = cp;
 500                         fclose(hostf);
 501                         return (-1);
 502                 }
 503                 goto again;
 504         }
 505         return (-1);
 506 }
 507
 508 /*
 509  * XXX
 510  * Don't make static, used by lpd(8).
 511  *
 512  * Returns 0 if ok, -1 if not ok.
 513  */
 514 int
 515 __ivaliduser(FILE *hostf, u_int32_t raddr, const char *luser, const char *ruser)
 516 {
 517         struct sockaddr_in sin;
 518
 519         memset(&sin, 0, sizeof(sin));
 520         sin.sin_family = AF_INET;
 521         sin.sin_len = sizeof(struct sockaddr_in);
 522         memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr));
 523         return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len,
 524                 luser, ruser);
 525 }
 526
 527 /*
 528  * Returns 0 if ok, -1 if not ok.
 529  *
 530  * XXX obsolete API.
 531  */
 532 int
 533 __ivaliduser_af(FILE *hostf, const void *raddr, const char *luser,
 534                 const char *ruser, int af, int len)
 535 {
 536         struct sockaddr *sa = NULL;
 537         struct sockaddr_in *sin = NULL;
 538 #ifdef INET6
 539         struct sockaddr_in6 *sin6 = NULL;
 540 #endif
 541         struct sockaddr_storage ss;
 542
 543         memset(&ss, 0, sizeof(ss));
 544         switch (af) {
 545         case AF_INET:
 546                 if (len != sizeof(sin->sin_addr))
 547                         return -1;
 548                 sin = (struct sockaddr_in *)&ss;
 549                 sin->sin_family = AF_INET;
 550                 sin->sin_len = sizeof(struct sockaddr_in);
 551                 memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr));
 552                 break;
 553 #ifdef INET6
 554         case AF_INET6:
 555                 if (len != sizeof(sin6->sin6_addr))
 556                         return -1;
 557                 /* you will lose scope info */
 558                 sin6 = (struct sockaddr_in6 *)&ss;
 559                 sin6->sin6_family = AF_INET6;
 560                 sin6->sin6_len = sizeof(struct sockaddr_in6);
 561                 memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr));
 562                 break;
 563 #endif
 564         default:
 565                 return -1;
 566         }
 567
 568         sa = (struct sockaddr *)&ss;
 569         return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser);
 570 }
 571
 572 /*
 573  * Returns 0 if ok, -1 if not ok.
 574  */
 575 int
 576 __ivaliduser_sa(FILE *hostf, const struct sockaddr *raddr, socklen_t salen,
 577                 const char *luser, const char *ruser)
 578 {
 579         char *user, *p;
 580         int ch;
 581         char buf[MAXHOSTNAMELEN + 128];         /* host + login */
 582         char hname[MAXHOSTNAMELEN];
 583         /* Presumed guilty until proven innocent. */
 584         int userok = 0, hostok = 0;
 585 #ifdef YP
 586         char *ypdomain;
 587
 588         if (yp_get_default_domain(&ypdomain))
 589                 ypdomain = NULL;
 590 #else
 591 #define ypdomain NULL
 592 #endif
 593         /* We need to get the damn hostname back for netgroup matching. */
 594         if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0,
 595                         NI_NAMEREQD) != 0)
 596                 hname[0] = '\0';
 597
 598         while (fgets(buf, sizeof(buf), hostf)) {
 599                 p = buf;
 600                 /* Skip lines that are too long. */
 601                 if (strchr(p, '\n') == NULL) {
 602                         while ((ch = getc(hostf)) != '\n' && ch != EOF);
 603                         continue;
 604                 }
 605                 if (*p == '\n' || *p == '#') {
 606                         /* comment... */
 607                         continue;
 608                 }
 609                 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
 610                         *p = isupper((unsigned char)*p) ? tolower((unsigned char)*p) : *p;
 611                         p++;
 612                 }
 613                 if (*p == ' ' || *p == '\t') {
 614                         *p++ = '\0';
 615                         while (*p == ' ' || *p == '\t')
 616                                 p++;
 617                         user = p;
 618                         while (*p != '\n' && *p != ' ' &&
 619                             *p != '\t' && *p != '\0')
 620                                 p++;
 621                 } else
 622                         user = p;
 623                 *p = '\0';
 624                 /*
 625                  * Do +/- and +@/-@ checking. This looks really nasty,
 626                  * but it matches SunOS's behavior so far as I can tell.
 627                  */
 628                 switch(buf[0]) {
 629                 case '+':
 630                         if (!buf[1]) {     /* '+' matches all hosts */
 631                                 hostok = 1;
 632                                 break;
 633                         }
 634                         if (buf[1] == '@')  /* match a host by netgroup */
 635                                 hostok = hname[0] != '\0' &&
 636                                     innetgr(&buf[2], hname, NULL, ypdomain);
 637                         else            /* match a host by addr */
 638                                 hostok = __icheckhost(raddr, salen,
 639                                                       (char *)&buf[1]);
 640                         break;
 641                 case '-':     /* reject '-' hosts and all their users */
 642                         if (buf[1] == '@') {
 643                                 if (hname[0] == '\0' ||
 644                                     innetgr(&buf[2], hname, NULL, ypdomain))
 645                                         return(-1);
 646                         } else {
 647                                 if (__icheckhost(raddr, salen,
 648                                                  (char *)&buf[1]))
 649                                         return(-1);
 650                         }
 651                         break;
 652                 default:  /* if no '+' or '-', do a simple match */
 653                         hostok = __icheckhost(raddr, salen, buf);
 654                         break;
 655                 }
 656                 switch(*user) {
 657                 case '+':
 658                         if (!*(user+1)) {      /* '+' matches all users */
 659                                 userok = 1;
 660                                 break;
 661                         }
 662                         if (*(user+1) == '@')  /* match a user by netgroup */
 663                                 userok = innetgr(user+2, NULL, ruser, ypdomain);
 664                         else       /* match a user by direct specification */
 665                                 userok = !(strcmp(ruser, user+1));
 666                         break;
 667                 case '-':               /* if we matched a hostname, */
 668                         if (hostok) {   /* check for user field rejections */
 669                                 if (!*(user+1))
 670                                         return(-1);
 671                                 if (*(user+1) == '@') {
 672                                         if (innetgr(user+2, NULL,
 673                                                         ruser, ypdomain))
 674                                                 return(-1);
 675                                 } else {
 676                                         if (!strcmp(ruser, user+1))
 677                                                 return(-1);
 678                                 }
 679                         }
 680                         break;
 681                 default:        /* no rejections: try to match the user */
 682                         if (hostok)
 683                                 userok = !(strcmp(ruser,*user ? user : luser));
 684                         break;
 685                 }
 686                 if (hostok && userok)
 687                         return(0);
 688         }
 689         return (-1);
 690 }
 691
 692 /*
 693  * Returns "true" if match, 0 if no match.
 694  *
 695  * NI_WITHSCOPEID is useful for comparing sin6_scope_id portion
 696  * if af == AF_INET6.
 697  */
 698 static int
 699 __icheckhost(const struct sockaddr *raddr, socklen_t salen, const char *lhost)
 700 {
 701         struct sockaddr_in sin;
 702         struct sockaddr_in6 *sin6;
 703         struct addrinfo hints, *res, *r;
 704         int error;
 705         char h1[NI_MAXHOST], h2[NI_MAXHOST];
 706
 707         if (raddr->sa_family == AF_INET6) {
 708                 sin6 = (struct sockaddr_in6 *)raddr;
 709                 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
 710                         memset(&sin, 0, sizeof(sin));
 711                         sin.sin_family = AF_INET;
 712                         sin.sin_len = sizeof(struct sockaddr_in);
 713                         memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12],
 714                                sizeof(sin.sin_addr));
 715                         raddr = (struct sockaddr *)&sin;
 716                         salen = sin.sin_len;
 717                 }
 718         }
 719
 720         h1[0] = '\0';
 721         if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0,
 722                         NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
 723                 return (0);
 724
 725         /* Resolve laddr into sockaddr */
 726         memset(&hints, 0, sizeof(hints));
 727         hints.ai_family = raddr->sa_family;
 728         hints.ai_socktype = SOCK_DGRAM; /*XXX dummy*/
 729         res = NULL;
 730         error = getaddrinfo(lhost, "0", &hints, &res);
 731         if (error)
 732                 return (0);
 733
 734         for (r = res; r ; r = r->ai_next) {
 735                 h2[0] = '\0';
 736                 if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2),
 737                                 NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
 738                         continue;
 739                 if (strcmp(h1, h2) == 0) {
 740                         freeaddrinfo(res);
 741                         return (1);
 742                 }
 743         }
 744
 745         /* No match. */
 746         freeaddrinfo(res);
 747         return (0);
 748 }