inet/rcmd.c

   1 /*
   2  * Copyright (C) 1998 WIDE Project.
   3  * 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 project 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 PROJECT 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 PROJECT 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 /*
  30  * Copyright (c) 1983, 1993, 1994
  31  *      The Regents of the University of California.  All rights reserved.
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58 #if defined(LIBC_SCCS) && !defined(lint)
  59 static char sccsid[] = "@(#)rcmd.c      8.3 (Berkeley) 3/26/94";
  60 #endif /* LIBC_SCCS and not lint */
  61
  62 #include <sys/param.h>
  63 #include <sys/poll.h>
  64 #include <sys/socket.h>
  65 #include <sys/stat.h>
  66
  67 #include <netinet/in.h>
  68 #include <arpa/inet.h>
  69
  70 #include <alloca.h>
  71 #include <signal.h>
  72 #include <fcntl.h>
  73 #include <netdb.h>
  74 #include <unistd.h>
  75 #include <pwd.h>
  76 #include <errno.h>
  77 #include <stdio.h>
  78 #include <stdio_ext.h>
  79 #include <ctype.h>
  80 #include <string.h>
  81 #include <libintl.h>
  82 #include <stdlib.h>
  83
  84
  85 int __ivaliduser (FILE *, u_int32_t, const char *, const char *);
  86 static int __validuser2_sa (FILE *, struct sockaddr *, size_t,
  87                             const char *, const char *, const char *);
  88 static int ruserok2_sa (struct sockaddr *ra, size_t ralen,
  89                         int superuser, const char *ruser,
  90                         const char *luser, const char *rhost);
  91 static int ruserok_sa (struct sockaddr *ra, size_t ralen,
  92                         int superuser, const char *ruser,
  93                         const char *luser);
  94 int iruserok_af (const void *raddr, int superuser, const char *ruser,
  95                  const char *luser, sa_family_t af);
  96 int iruserok (u_int32_t raddr, int superuser, const char *ruser,
  97               const char *luser);
  98
  99 static char ahostbuf[NI_MAXHOST];
 100
 101 int
 102 rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af)
 103         char **ahost;
 104         u_short rport;
 105         const char *locuser, *remuser, *cmd;
 106         int *fd2p;
 107         sa_family_t af;
 108 {
 109         char paddr[INET6_ADDRSTRLEN];
 110         struct addrinfo hints, *res, *ai;
 111         struct sockaddr_storage from;
 112         struct pollfd pfd[2];
 113         int32_t oldmask;
 114         pid_t pid;
 115         int s, lport, timo, error;
 116         char c;
 117         int refused;
 118         char num[8];
 119         ssize_t n;
 120
 121         if (af != AF_INET && af != AF_INET6 && af != AF_UNSPEC)
 122           {
 123             __set_errno (EAFNOSUPPORT);
 124             return -1;
 125           }
 126
 127         pid = __getpid();
 128
 129         memset(&hints, '\0', sizeof(hints));
 130         hints.ai_flags = AI_CANONNAME;
 131         hints.ai_family = af;
 132         hints.ai_socktype = SOCK_STREAM;
 133         (void)__snprintf(num, sizeof(num), "%d", ntohs(rport));
 134         error = getaddrinfo(*ahost, num, &hints, &res);
 135         if (error) {
 136             fprintf(stderr, "rcmd: getaddrinfo: %s\n",
 137                     gai_strerror(error));
 138                 return (-1);
 139         }
 140
 141         pfd[0].events = POLLIN;
 142         pfd[1].events = POLLIN;
 143
 144         if (res->ai_canonname){
 145                 strncpy(ahostbuf, res->ai_canonname, sizeof(ahostbuf));
 146                 ahostbuf[sizeof(ahostbuf)-1] = '\0';
 147                 *ahost = ahostbuf;
 148         }
 149         else
 150                 *ahost = NULL;
 151         ai = res;
 152         refused = 0;
 153         oldmask = __sigblock(sigmask(SIGURG));
 154         for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
 155                 s = rresvport_af(&lport, ai->ai_family);
 156                 if (s < 0) {
 157                         if (errno == EAGAIN)
 158                                 fprintf(stderr,
 159                                         _("rcmd: socket: All ports in use\n"));
 160                         else
 161                                 fprintf(stderr, "rcmd: socket: %m\n");
 162                         __sigsetmask(oldmask);
 163                         freeaddrinfo(res);
 164                         return -1;
 165                 }
 166                 __fcntl(s, F_SETOWN, pid);
 167                 if (__connect(s, ai->ai_addr, ai->ai_addrlen) >= 0)
 168                         break;
 169                 (void)__close(s);
 170                 if (errno == EADDRINUSE) {
 171                         lport--;
 172                         continue;
 173                 }
 174                 if (errno == ECONNREFUSED)
 175                         refused = 1;
 176                 if (ai->ai_next != NULL) {
 177                         int oerrno = errno;
 178
 179                         getnameinfo(ai->ai_addr, ai->ai_addrlen,
 180                                     paddr, sizeof(paddr),
 181                                     NULL, 0,
 182                                     NI_NUMERICHOST);
 183                         fprintf(stderr, "connect to address %s: ", paddr);
 184                         __set_errno (oerrno);
 185                         perror(0);
 186                         ai = ai->ai_next;
 187                         getnameinfo(ai->ai_addr, ai->ai_addrlen,
 188                                     paddr, sizeof(paddr),
 189                                     NULL, 0,
 190                                     NI_NUMERICHOST);
 191                         fprintf(stderr, "Trying %s...\n", paddr);
 192                         continue;
 193                 }
 194                 if (refused && timo <= 16) {
 195                         (void)__sleep(timo);
 196                         timo *= 2;
 197                         ai = res;
 198                         refused = 0;
 199                         continue;
 200                 }
 201                 freeaddrinfo(res);
 202                 (void)fprintf(stderr, "%s: %s\n", *ahost, strerror(errno));
 203                 __sigsetmask(oldmask);
 204                 return -1;
 205         }
 206         lport--;
 207         if (fd2p == 0) {
 208                 __write(s, "", 1);
 209                 lport = 0;
 210         } else {
 211                 char num[8];
 212                 int s2 = rresvport_af(&lport, ai->ai_family), s3;
 213                 socklen_t len = ai->ai_addrlen;
 214
 215                 if (s2 < 0)
 216                         goto bad;
 217                 listen(s2, 1);
 218                 (void)__snprintf(num, sizeof(num), "%d", lport);
 219                 if (__write(s, num, strlen(num)+1) != (ssize_t)strlen(num)+1) {
 220                         (void)fprintf(stderr,
 221                             _("rcmd: write (setting up stderr): %m\n"));
 222                         (void)__close(s2);
 223                         goto bad;
 224                 }
 225                 pfd[0].fd = s;
 226                 pfd[1].fd = s2;
 227                 __set_errno (0);
 228                 if (__poll (pfd, 2, -1) < 1 || (pfd[1].revents & POLLIN) == 0){
 229                         if (errno != 0)
 230                                 (void)fprintf(stderr,
 231                                   _("rcmd: poll (setting up stderr): %m\n"));
 232                         else
 233                                 (void)fprintf(stderr,
 234                              _("poll: protocol failure in circuit setup\n"));
 235                         (void)__close(s2);
 236                         goto bad;
 237                 }
 238                 s3 = accept(s2, (struct sockaddr *)&from, &len);
 239                 switch (from.ss_family) {
 240                 case AF_INET:
 241                         rport = ntohs(((struct sockaddr_in *)&from)->sin_port);
 242                         break;
 243                 case AF_INET6:
 244                         rport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port);
 245                         break;
 246                 default:
 247                         rport = 0;
 248                         break;
 249                 }
 250                 (void)__close(s2);
 251                 if (s3 < 0) {
 252                         (void)fprintf(stderr,
 253                             "rcmd: accept: %m\n");
 254                         lport = 0;
 255                         goto bad;
 256                 }
 257                 *fd2p = s3;
 258
 259                 if (rport >= IPPORT_RESERVED || rport < IPPORT_RESERVED / 2){
 260                         (void)fprintf(stderr,
 261                         _("socket: protocol failure in circuit setup\n"));
 262                         goto bad2;
 263                 }
 264         }
 265         (void)__write(s, locuser, strlen(locuser)+1);
 266         (void)__write(s, remuser, strlen(remuser)+1);
 267         (void)__write(s, cmd, strlen(cmd)+1);
 268         n = __read(s, &c, 1);
 269         if (n != 1) {
 270                 if (n == 0)
 271                         (void)fprintf(stderr, _("rcmd: %s: short read"),
 272                                       *ahost);
 273                 else
 274                         (void)fprintf(stderr, "rcmd: %s: %m\n", *ahost);
 275                 goto bad2;
 276         }
 277         if (c != 0) {
 278                 while (__read(s, &c, 1) == 1) {
 279                         (void)__write(STDERR_FILENO, &c, 1);
 280                         if (c == '\n')
 281                                 break;
 282                 }
 283                 goto bad2;
 284         }
 285         __sigsetmask(oldmask);
 286         freeaddrinfo(res);
 287         return s;
 288 bad2:
 289         if (lport)
 290                 (void)__close(*fd2p);
 291 bad:
 292         (void)__close(s);
 293         __sigsetmask(oldmask);
 294         freeaddrinfo(res);
 295         return -1;
 296 }
 297
 298 int
 299 rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
 300         char **ahost;
 301         u_short rport;
 302         const char *locuser, *remuser, *cmd;
 303         int *fd2p;
 304 {
 305   return rcmd_af (ahost, rport, locuser, remuser, cmd, fd2p, AF_INET);
 306 }
 307
 308 int
 309 rresvport_af(alport, family)
 310         int *alport;
 311         sa_family_t family;
 312 {
 313         struct sockaddr_storage ss;
 314         int s;
 315         size_t len;
 316         uint16_t *sport;
 317
 318         switch(family){
 319         case AF_INET:
 320                 len = sizeof(struct sockaddr_in);
 321                 sport = &((struct sockaddr_in *)&ss)->sin_port;
 322                 break;
 323         case AF_INET6:
 324                 len = sizeof(struct sockaddr_in6);
 325                 sport = &((struct sockaddr_in6 *)&ss)->sin6_port;
 326                 break;
 327         default:
 328                 __set_errno (EAFNOSUPPORT);
 329                 return -1;
 330         }
 331         s = __socket(family, SOCK_STREAM, 0);
 332         if (s < 0)
 333                 return -1;
 334
 335         memset (&ss, '\0', sizeof(ss));
 336 #ifdef SALEN
 337         ss.__ss_len = len;
 338 #endif
 339         ss.ss_family = family;
 340
 341         for (;;) {
 342                 *sport = htons((uint16_t) *alport);
 343                 if (bind(s, (struct sockaddr *)&ss, len) >= 0)
 344                         return s;
 345                 if (errno != EADDRINUSE) {
 346                         (void)__close(s);
 347                         return -1;
 348                 }
 349                 (*alport)--;
 350                 if (*alport == IPPORT_RESERVED/2)
 351                         break;
 352         }
 353         (void)__close(s);
 354         __set_errno (EAGAIN);
 355         return -1;
 356 }
 357
 358 int
 359 rresvport(alport)
 360         int *alport;
 361 {
 362         return rresvport_af(alport, AF_INET);
 363 }
 364
 365 int     __check_rhosts_file = 1;
 366 char    *__rcmd_errstr;
 367
 368 int
 369 ruserok_af(rhost, superuser, ruser, luser, af)
 370         const char *rhost, *ruser, *luser;
 371         int superuser;
 372         sa_family_t af;
 373 {
 374         struct addrinfo hints, *res, *res0;
 375         int gai;
 376         int ret;
 377
 378         memset (&hints, '\0', sizeof(hints));
 379         hints.ai_family = af;
 380         gai = getaddrinfo(rhost, NULL, &hints, &res0);
 381         if (gai)
 382                 return -1;
 383         ret = -1;
 384         for (res=res0; res; res=res->ai_next)
 385                 if (ruserok2_sa(res->ai_addr, res->ai_addrlen,
 386                                 superuser, ruser, luser, rhost) == 0){
 387                         ret = 0;
 388                         break;
 389                 }
 390         freeaddrinfo(res0);
 391         return (ret);
 392 }
 393 int
 394 ruserok(rhost, superuser, ruser, luser)
 395         const char *rhost, *ruser, *luser;
 396         int superuser;
 397 {
 398         return ruserok_af(rhost, superuser, ruser, luser, AF_INET);
 399 }
 400
 401 /* Extremely paranoid file open function. */
 402 static FILE *
 403 iruserfopen (const char *file, uid_t okuser)
 404 {
 405   struct stat64 st;
 406   char *cp = NULL;
 407   FILE *res = NULL;
 408
 409   /* If not a regular file, if owned by someone other than user or
 410      root, if writeable by anyone but the owner, or if hardlinked
 411      anywhere, quit.  */
 412   cp = NULL;
 413   if (__lxstat64 (_STAT_VER, file, &st))
 414     cp = _("lstat failed");
 415   else if (!S_ISREG (st.st_mode))
 416     cp = _("not regular file");
 417   else
 418     {
 419       res = fopen (file, "r");
 420       if (!res)
 421         cp = _("cannot open");
 422       else if (__fxstat64 (_STAT_VER, fileno (res), &st) < 0)
 423         cp = _("fstat failed");
 424       else if (st.st_uid && st.st_uid != okuser)
 425         cp = _("bad owner");
 426       else if (st.st_mode & (S_IWGRP|S_IWOTH))
 427         cp = _("writeable by other than owner");
 428       else if (st.st_nlink > 1)
 429         cp = _("hard linked somewhere");
 430     }
 431
 432   /* If there were any problems, quit.  */
 433   if (cp != NULL)
 434     {
 435       __rcmd_errstr = cp;
 436       if (res)
 437         fclose (res);
 438       return NULL;
 439     }
 440
 441   /* No threads use this stream.  */
 442   __fsetlocking (res, FSETLOCKING_BYCALLER);
 443
 444   return res;
 445 }
 446
 447 /*
 448  * New .rhosts strategy: We are passed an ip address. We spin through
 449  * hosts.equiv and .rhosts looking for a match. When the .rhosts only
 450  * has ip addresses, we don't have to trust a nameserver.  When it
 451  * contains hostnames, we spin through the list of addresses the nameserver
 452  * gives us and look for a match.
 453  *
 454  * Returns 0 if ok, -1 if not ok.
 455  */
 456 static int
 457 ruserok2_sa (ra, ralen, superuser, ruser, luser, rhost)
 458      struct sockaddr *ra;
 459      size_t ralen;
 460      int superuser;
 461      const char *ruser, *luser, *rhost;
 462 {
 463   FILE *hostf = NULL;
 464   int isbad = -1;
 465
 466   if (!superuser)
 467     hostf = iruserfopen (_PATH_HEQUIV, 0);
 468
 469   if (hostf)
 470     {
 471       isbad = __validuser2_sa (hostf, ra, ralen, luser, ruser, rhost);
 472       fclose (hostf);
 473
 474       if (!isbad)
 475         return 0;
 476     }
 477
 478   if (__check_rhosts_file || superuser)
 479     {
 480       char *pbuf;
 481       struct passwd pwdbuf, *pwd;
 482       size_t dirlen;
 483       size_t buflen = __sysconf (_SC_GETPW_R_SIZE_MAX);
 484       char *buffer = __alloca (buflen);
 485       uid_t uid;
 486
 487       if (__getpwnam_r (luser, &pwdbuf, buffer, buflen, &pwd) != 0
 488           || pwd == NULL)
 489         return -1;
 490
 491       dirlen = strlen (pwd->pw_dir);
 492       pbuf = alloca (dirlen + sizeof "/.rhosts");
 493       __mempcpy (__mempcpy (pbuf, pwd->pw_dir, dirlen),
 494                  "/.rhosts", sizeof "/.rhosts");
 495
 496        /* Change effective uid while reading .rhosts.  If root and
 497           reading an NFS mounted file system, can't read files that
 498           are protected read/write owner only.  */
 499        uid = __geteuid ();
 500        seteuid (pwd->pw_uid);
 501        hostf = iruserfopen (pbuf, pwd->pw_uid);
 502
 503        if (hostf != NULL)
 504          {
 505            isbad = __validuser2_sa (hostf, ra, ralen, luser, ruser, rhost);
 506            fclose (hostf);
 507          }
 508
 509        seteuid (uid);
 510        return isbad;
 511     }
 512   return -1;
 513 }
 514 /*
 515  * ruserok_sa() is now discussed on ipng, so
 516  * currently disabled for external use
 517  */
 518 static int ruserok_sa(ra, ralen, superuser, ruser, luser)
 519      struct sockaddr *ra;
 520      size_t ralen;
 521      int superuser;
 522      const char *ruser, *luser;
 523 {
 524   return ruserok2_sa(ra, ralen, superuser, ruser, luser, "-");
 525 }
 526
 527 /* This is the exported version.  */
 528 int
 529 iruserok_af (raddr, superuser, ruser, luser, af)
 530      const void *raddr;
 531      int superuser;
 532      const char *ruser, *luser;
 533      sa_family_t af;
 534 {
 535   struct sockaddr_storage ra;
 536   size_t ralen;
 537
 538   memset (&ra, '\0', sizeof(ra));
 539   switch (af){
 540   case AF_INET:
 541     ((struct sockaddr_in *)&ra)->sin_family = AF_INET;
 542     memcpy (&(((struct sockaddr_in *)&ra)->sin_addr), raddr,
 543             sizeof(struct in_addr));
 544     ralen = sizeof(struct sockaddr_in);
 545     break;
 546   case AF_INET6:
 547     ((struct sockaddr_in6 *)&ra)->sin6_family = AF_INET6;
 548     memcpy (&(((struct sockaddr_in6 *)&ra)->sin6_addr), raddr,
 549             sizeof(struct in6_addr));
 550     ralen = sizeof(struct sockaddr_in6);
 551     break;
 552   default:
 553     return 0;
 554   }
 555   return ruserok_sa ((struct sockaddr *)&ra, ralen, superuser, ruser, luser);
 556 }
 557 int
 558 iruserok (raddr, superuser, ruser, luser)
 559      u_int32_t raddr;
 560      int superuser;
 561      const char *ruser, *luser;
 562 {
 563   return iruserok_af (&raddr, superuser, ruser, luser, AF_INET);
 564 }
 565
 566 /*
 567  * XXX
 568  * Don't make static, used by lpd(8).
 569  *
 570  * This function is not used anymore. It is only present because lpd(8)
 571  * calls it (!?!). We simply call __invaliduser2() with an illegal rhost
 572  * argument. This means that netgroups won't work in .rhost/hosts.equiv
 573  * files. If you want lpd to work with netgroups, fix lpd to use ruserok()
 574  * or PAM.
 575  * Returns 0 if ok, -1 if not ok.
 576  */
 577 int
 578 __ivaliduser(hostf, raddr, luser, ruser)
 579         FILE *hostf;
 580         u_int32_t raddr;
 581         const char *luser, *ruser;
 582 {
 583         struct sockaddr_in ra;
 584         memset(&ra, '\0', sizeof(ra));
 585         ra.sin_family = AF_INET;
 586         ra.sin_addr.s_addr = raddr;
 587         return __validuser2_sa(hostf, (struct sockaddr *)&ra, sizeof(ra),
 588                                luser, ruser, "-");
 589 }
 590
 591
 592 /* Returns 1 on positive match, 0 on no match, -1 on negative match.  */
 593 static int
 594 internal_function
 595 __checkhost_sa (struct sockaddr *ra, size_t ralen, char *lhost,
 596                 const char *rhost)
 597 {
 598         struct addrinfo hints, *res0, *res;
 599         char raddr[INET6_ADDRSTRLEN];
 600         int match;
 601         int negate=1;    /* Multiply return with this to get -1 instead of 1 */
 602
 603         /* Check nis netgroup.  */
 604         if (strncmp ("+@", lhost, 2) == 0)
 605                 return innetgr (&lhost[2], rhost, NULL, NULL);
 606
 607         if (strncmp ("-@", lhost, 2) == 0)
 608                 return -innetgr (&lhost[2], rhost, NULL, NULL);
 609
 610         /* -host */
 611         if (strncmp ("-", lhost,1) == 0) {
 612                 negate = -1;
 613                 lhost++;
 614         } else if (strcmp ("+",lhost) == 0) {
 615                 return 1;                    /* asking for trouble, but ok.. */
 616         }
 617
 618         /* Try for raw ip address first. */
 619         /* XXX */
 620         if (getnameinfo(ra, ralen,
 621                         raddr, sizeof(raddr), NULL, 0,
 622                         NI_NUMERICHOST) == 0
 623             && strcmp(raddr, lhost) == 0)
 624                 return negate;
 625
 626         /* Better be a hostname. */
 627         match = 0;
 628         memset(&hints, '\0', sizeof(hints));
 629         hints.ai_family = ra->sa_family;
 630         if (getaddrinfo(lhost, NULL, &hints, &res0) == 0){
 631                 /* Spin through ip addresses. */
 632                 for (res = res0; res; res = res->ai_next)
 633                   {
 634                     if (res->ai_family == ra->sa_family
 635                         && !memcmp(res->ai_addr, ra, res->ai_addrlen))
 636                       {
 637                         match = 1;
 638                         break;
 639                       }
 640                   }
 641                 freeaddrinfo (res0);
 642         }
 643         return negate * match;
 644 }
 645
 646 /* Returns 1 on positive match, 0 on no match, -1 on negative match.  */
 647 static int
 648 internal_function
 649 __icheckuser (const char *luser, const char *ruser)
 650 {
 651     /*
 652       luser is user entry from .rhosts/hosts.equiv file
 653       ruser is user id on remote host
 654       */
 655
 656     /* [-+]@netgroup */
 657     if (strncmp ("+@", luser, 2) == 0)
 658         return innetgr (&luser[2], NULL, ruser, NULL);
 659
 660     if (strncmp ("-@", luser,2) == 0)
 661         return -innetgr (&luser[2], NULL, ruser, NULL);
 662
 663     /* -user */
 664     if (strncmp ("-", luser, 1) == 0)
 665         return -(strcmp (&luser[1], ruser) == 0);
 666
 667     /* + */
 668     if (strcmp ("+", luser) == 0)
 669         return 1;
 670
 671     /* simple string match */
 672     return strcmp (ruser, luser) == 0;
 673 }
 674
 675 /*
 676  * Returns 1 for blank lines (or only comment lines) and 0 otherwise
 677  */
 678 static int
 679 __isempty (char *p)
 680 {
 681     while (*p && isspace (*p)) {
 682         ++p;
 683     }
 684
 685     return (*p == '\0' || *p == '#') ? 1 : 0 ;
 686 }
 687
 688 /*
 689  * Returns 0 if positive match, -1 if _not_ ok.
 690  */
 691 static int
 692 __validuser2_sa(hostf, ra, ralen, luser, ruser, rhost)
 693         FILE *hostf;
 694         struct sockaddr *ra;
 695         size_t ralen;
 696         const char *luser, *ruser, *rhost;
 697 {
 698     register const char *user;
 699     register char *p;
 700     int hcheck, ucheck;
 701     char *buf = NULL;
 702     size_t bufsize = 0;
 703     int retval = -1;
 704
 705     while (__getline (&buf, &bufsize, hostf) > 0) {
 706         buf[bufsize - 1] = '\0'; /* Make sure it's terminated.  */
 707         p = buf;
 708
 709         /* Skip empty or comment lines */
 710         if (__isempty (p)) {
 711             continue;
 712         }
 713
 714         /* Skip lines that are too long. */
 715         if (strchr (p, '\n') == NULL) {
 716             int ch = getc_unlocked (hostf);
 717
 718             while (ch != '\n' && ch != EOF)
 719                 ch = getc_unlocked (hostf);
 720             continue;
 721         }
 722
 723         for (;*p && !isspace(*p); ++p) {
 724             *p = _tolower (*p);
 725         }
 726
 727         /* Next we want to find the permitted name for the remote user.  */
 728         if (*p == ' ' || *p == '\t') {
 729             /* <nul> terminate hostname and skip spaces */
 730             for (*p++='\0'; *p && isspace (*p); ++p);
 731
 732             user = p;                   /* this is the user's name */
 733             while (*p && !isspace (*p))
 734                 ++p;                    /* find end of user's name */
 735         } else
 736             user = p;
 737
 738         *p = '\0';              /* <nul> terminate username (+host?) */
 739
 740         /* buf -> host(?) ; user -> username(?) */
 741
 742         /* First check host part */
 743         hcheck = __checkhost_sa (ra, ralen, buf, rhost);
 744
 745         if (hcheck < 0)
 746             break;
 747
 748         if (hcheck) {
 749             /* Then check user part */
 750             if (! (*user))
 751                 user = luser;
 752
 753             ucheck = __icheckuser (user, ruser);
 754
 755             /* Positive 'host user' match? */
 756             if (ucheck > 0) {
 757                 retval = 0;
 758                 break;
 759             }
 760
 761             /* Negative 'host -user' match? */
 762             if (ucheck < 0)
 763                 break;
 764
 765             /* Neither, go on looking for match */
 766         }
 767     }
 768
 769     if (buf != NULL)
 770       free (buf);
 771
 772     return retval;
 773 }