revnetgroup.tproj/parse_netgroup.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /* $OpenBSD: parse_netgroup.c,v 1.2 1997/08/18 03:11:35 millert Exp $ */
  24 /*
  25  * Copyright (c) 1992, 1993
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * This code is derived from software contributed to Berkeley by
  29  * Rick Macklem at The University of Guelph.
  30  *
  31  * Redistribution and use in source and binary forms, with or without
  32  * modification, are permitted provided that the following conditions
  33  * are met:
  34  * 1. Redistributions of source code must retain the above copyright
  35  *    notice, this list of conditions and the following disclaimer.
  36  * 2. Redistributions in binary form must reproduce the above copyright
  37  *    notice, this list of conditions and the following disclaimer in the
  38  *    documentation and/or other materials provided with the distribution.
  39  * 3. All advertising materials mentioning features or use of this software
  40  *    must display the following acknowledgement:
  41  *      This product includes software developed by the University of
  42  *      California, Berkeley and its contributors.
  43  * 4. Neither the name of the University nor the names of its contributors
  44  *    may be used to endorse or promote products derived from this software
  45  *    without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  57  * SUCH DAMAGE.
  58  *
  59  *      $FreeBSD: parse_netgroup.c,v 1.5 1997/02/22 14:22:02 peter Exp $
  60  */
  61
  62 /*
  63  * This is a specially hacked-up version of getnetgrent.c used to parse
  64  * data from the stored hash table of netgroup info rather than from a
  65  * file. It's used mainly for the parse_netgroup() function. All the YP
  66  * stuff and file support has been stripped out since it isn't needed.
  67  */
  68
  69 #include <stdio.h>
  70 #include <string.h>
  71 #include <stdlib.h>
  72 #include <unistd.h>
  73 #include "hash.h"
  74
  75 #ifndef lint
  76 static const char rcsid[] = "$OpenBSD: parse_netgroup.c,v 1.2 1997/08/18 03:11:35 millert Exp $";
  77 #endif
  78
  79 /*
  80  * Static Variables and functions used by setnetgrent(), getnetgrent() and
  81  * __endnetgrent().
  82  * There are two linked lists:
  83  * - linelist is just used by setnetgrent() to parse the net group file via.
  84  *   parse_netgrp()
  85  * - netgrp is the list of entries for the current netgroup
  86  */
  87 struct linelist {
  88         struct linelist *l_next;        /* Chain ptr. */
  89         int             l_parsed;       /* Flag for cycles */
  90         char            *l_groupname;   /* Name of netgroup */
  91         char            *l_line;        /* Netgroup entrie(s) to be parsed */
  92 };
  93
  94 struct netgrp {
  95         struct netgrp   *ng_next;       /* Chain ptr */
  96         char            *ng_str[3];     /* Field pointers, see below */
  97 };
  98 #define NG_HOST         0       /* Host name */
  99 #define NG_USER         1       /* User name */
 100 #define NG_DOM          2       /* and Domain name */
 101
 102 static struct linelist  *linehead = (struct linelist *)0;
 103 static struct netgrp    *nextgrp = (struct netgrp *)0;
 104 static struct {
 105         struct netgrp   *gr;
 106         char            *grname;
 107 } grouphead = {
 108         (struct netgrp *)0,
 109         (char *)0,
 110 };
 111 static int parse_netgrp();
 112 static struct linelist *read_for_group();
 113 void __setnetgrent(), __endnetgrent();
 114 int __getnetgrent();
 115 extern struct group_entry *gtable[];
 116
 117 /*
 118  * setnetgrent()
 119  * Parse the netgroup file looking for the netgroup and build the list
 120  * of netgrp structures. Let parse_netgrp() and read_for_group() do
 121  * most of the work.
 122  */
 123 void
 124 __setnetgrent(group)
 125         char *group;
 126 {
 127         /* Sanity check */
 128
 129         if (group == NULL || !strlen(group))
 130                 return;
 131
 132         if (grouphead.gr == (struct netgrp *)0 ||
 133                 strcmp(group, grouphead.grname)) {
 134                 __endnetgrent();
 135                 if (parse_netgrp(group))
 136                         __endnetgrent();
 137                 else {
 138                         grouphead.grname = (char *)
 139                                 malloc(strlen(group) + 1);
 140                         strcpy(grouphead.grname, group);
 141                 }
 142         }
 143         nextgrp = grouphead.gr;
 144 }
 145
 146 /*
 147  * Get the next netgroup off the list.
 148  */
 149 int
 150 __getnetgrent(hostp, userp, domp)
 151         char **hostp, **userp, **domp;
 152 {
 153         if (nextgrp) {
 154                 *hostp = nextgrp->ng_str[NG_HOST];
 155                 *userp = nextgrp->ng_str[NG_USER];
 156                 *domp = nextgrp->ng_str[NG_DOM];
 157                 nextgrp = nextgrp->ng_next;
 158                 return (1);
 159         }
 160         return (0);
 161 }
 162
 163 /*
 164  * __endnetgrent() - cleanup
 165  */
 166 void
 167 __endnetgrent()
 168 {
 169         register struct linelist *lp, *olp;
 170         register struct netgrp *gp, *ogp;
 171
 172         lp = linehead;
 173         while (lp) {
 174                 olp = lp;
 175                 lp = lp->l_next;
 176                 free(olp->l_groupname);
 177                 free(olp->l_line);
 178                 free((char *)olp);
 179         }
 180         linehead = (struct linelist *)0;
 181         if (grouphead.grname) {
 182                 free(grouphead.grname);
 183                 grouphead.grname = (char *)0;
 184         }
 185         gp = grouphead.gr;
 186         while (gp) {
 187                 ogp = gp;
 188                 gp = gp->ng_next;
 189                 if (ogp->ng_str[NG_HOST])
 190                         free(ogp->ng_str[NG_HOST]);
 191                 if (ogp->ng_str[NG_USER])
 192                         free(ogp->ng_str[NG_USER]);
 193                 if (ogp->ng_str[NG_DOM])
 194                         free(ogp->ng_str[NG_DOM]);
 195                 free((char *)ogp);
 196         }
 197         grouphead.gr = (struct netgrp *)0;
 198 }
 199
 200 /*
 201  * Parse the netgroup file setting up the linked lists.
 202  */
 203 static int
 204 parse_netgrp(group)
 205         char *group;
 206 {
 207         register char *spos, *epos;
 208         register int len, strpos;
 209 #ifdef DEBUG
 210         register int fields;
 211 #endif
 212         char *pos, *gpos;
 213         struct netgrp *grp;
 214         struct linelist *lp = linehead;
 215
 216         /*
 217          * First, see if the line has already been read in.
 218          */
 219         while (lp) {
 220                 if (!strcmp(group, lp->l_groupname))
 221                         break;
 222                 lp = lp->l_next;
 223         }
 224         if (lp == (struct linelist *)0 &&
 225             (lp = read_for_group(group)) == (struct linelist *)0)
 226                 return (1);
 227         if (lp->l_parsed) {
 228 #ifdef DEBUG
 229                 /*
 230                  * This error message is largely superflous since the
 231                  * code handles the error condition sucessfully, and
 232                  * spewing it out from inside libc can actually hose
 233                  * certain programs.
 234                  */
 235                 fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname);
 236 #endif
 237                 return (1);
 238         } else
 239                 lp->l_parsed = 1;
 240         pos = lp->l_line;
 241         /* Watch for null pointer dereferences, dammit! */
 242         while (pos != NULL && *pos != '\0') {
 243                 if (*pos == '(') {
 244                         grp = (struct netgrp *)malloc(sizeof (struct netgrp));
 245                         bzero((char *)grp, sizeof (struct netgrp));
 246                         grp->ng_next = grouphead.gr;
 247                         grouphead.gr = grp;
 248                         pos++;
 249                         gpos = strsep(&pos, ")");
 250 #ifdef DEBUG
 251                         fields = 0;
 252 #endif
 253                         for (strpos = 0; strpos < 3; strpos++) {
 254                                 if ((spos = strsep(&gpos, ","))) {
 255 #ifdef DEBUG
 256                                         fields++;
 257 #endif
 258                                         while (*spos == ' ' || *spos == '\t')
 259                                                 spos++;
 260                                         if ((epos = strpbrk(spos, " \t"))) {
 261                                                 *epos = '\0';
 262                                                 len = epos - spos;
 263                                         } else
 264                                                 len = strlen(spos);
 265                                         if (len > 0) {
 266                                                 grp->ng_str[strpos] =  (char *)
 267                                                         malloc(len + 1);
 268                                                 bcopy(spos, grp->ng_str[strpos],
 269                                                         len + 1);
 270                                         }
 271                                 } else {
 272                                         /*
 273                                          * All other systems I've tested
 274                                          * return NULL for empty netgroup
 275                                          * fields. It's up to user programs
 276                                          * to handle the NULLs appropriately.
 277                                          */
 278                                         grp->ng_str[strpos] = NULL;
 279                                 }
 280                         }
 281 #ifdef DEBUG
 282                         /*
 283                          * Note: on other platforms, malformed netgroup
 284                          * entries are not normally flagged. While we
 285                          * can catch bad entries and report them, we should
 286                          * stay silent by default for compatibility's sake.
 287                          */
 288                         if (fields < 3)
 289                                         fprintf(stderr, "Bad entry (%s%s%s%s%s) in netgroup \"%s\"\n",
 290                                                 grp->ng_str[NG_HOST] == NULL ? "" : grp->ng_str[NG_HOST],
 291                                                 grp->ng_str[NG_USER] == NULL ? "" : ",",
 292                                                 grp->ng_str[NG_USER] == NULL ? "" : grp->ng_str[NG_USER],
 293                                                 grp->ng_str[NG_DOM] == NULL ? "" : ",",
 294                                                 grp->ng_str[NG_DOM] == NULL ? "" : grp->ng_str[NG_DOM],
 295                                                 lp->l_groupname);
 296 #endif
 297                 } else {
 298                         spos = strsep(&pos, ", \t");
 299                         if (parse_netgrp(spos))
 300                                 continue;
 301                 }
 302                 /* Watch for null pointer dereferences, dammit! */
 303                 if (pos != NULL)
 304                         while (*pos == ' ' || *pos == ',' || *pos == '\t')
 305                                 pos++;
 306         }
 307         return (0);
 308 }
 309
 310 /*
 311  * Read the netgroup file and save lines until the line for the netgroup
 312  * is found. Return 1 if eof is encountered.
 313  */
 314 static struct linelist *
 315 read_for_group(group)
 316         char *group;
 317 {
 318         register char *pos, *spos, *linep = NULL, *olinep = NULL;
 319         register int len, olen;
 320         int cont;
 321         struct linelist *lp;
 322         char line[LINSIZ + 1];
 323         char *data = NULL;
 324
 325         data = lookup (gtable, group);
 326         sprintf(line, "%s %s", group, data);
 327         pos = (char *)&line;
 328 #ifdef CANT_HAPPEN
 329         if (*pos == '#')
 330                 continue;
 331 #endif
 332         while (*pos == ' ' || *pos == '\t')
 333                 pos++;
 334         spos = pos;
 335         while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
 336                 *pos != '\0')
 337                 pos++;
 338         len = pos - spos;
 339         while (*pos == ' ' || *pos == '\t')
 340                 pos++;
 341         if (*pos != '\n' && *pos != '\0') {
 342                 lp = (struct linelist *)malloc(sizeof (*lp));
 343                 lp->l_parsed = 0;
 344                 lp->l_groupname = (char *)malloc(len + 1);
 345                 bcopy(spos, lp->l_groupname, len);
 346                 *(lp->l_groupname + len) = '\0';
 347                 len = strlen(pos);
 348                 olen = 0;
 349                         /*
 350                          * Loop around handling line continuations.
 351                          */
 352                         do {
 353                                 if (*(pos + len - 1) == '\n')
 354                                         len--;
 355                                 if (*(pos + len - 1) == '\\') {
 356                                         len--;
 357                                         cont = 1;
 358                                 } else
 359                                         cont = 0;
 360                                 if (len > 0) {
 361                                         linep = (char *)malloc(olen + len + 1);
 362                                         if (olen > 0) {
 363                                                 bcopy(olinep, linep, olen);
 364                                                 free(olinep);
 365                                         }
 366                                         bcopy(pos, linep + olen, len);
 367                                         olen += len;
 368                                         *(linep + olen) = '\0';
 369                                         olinep = linep;
 370                                 }
 371 #ifdef CANT_HAPPEN
 372                                 if (cont) {
 373                                         if (fgets(line, LINSIZ, netf)) {
 374                                                 pos = line;
 375                                                 len = strlen(pos);
 376                                         } else
 377                                                 cont = 0;
 378                                 }
 379 #endif
 380                         } while (cont);
 381                 lp->l_line = linep;
 382                 lp->l_next = linehead;
 383                 linehead = lp;
 384 #ifdef CANT_HAPPEN
 385                 /*
 386                  * If this is the one we wanted, we are done.
 387                  */
 388                 if (!strcmp(lp->l_groupname, group))
 389 #endif
 390                         return (lp);
 391         }
 392         return ((struct linelist *)0);
 393 }