revnetgroup.tproj/parse_netgroup.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * "Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.0 (the 'License').  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License."
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /* $OpenBSD: parse_netgroup.c,v 1.2 1997/08/18 03:11:35 millert Exp $ */
  25 /*
  26  * Copyright (c) 1992, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * This code is derived from software contributed to Berkeley by
  30  * Rick Macklem at The University of Guelph.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      $FreeBSD: parse_netgroup.c,v 1.5 1997/02/22 14:22:02 peter Exp $
  61  */
  62
  63 /*
  64  * This is a specially hacked-up version of getnetgrent.c used to parse
  65  * data from the stored hash table of netgroup info rather than from a
  66  * file. It's used mainly for the parse_netgroup() function. All the YP
  67  * stuff and file support has been stripped out since it isn't needed.
  68  */
  69
  70 #include <stdio.h>
  71 #include <string.h>
  72 #include <stdlib.h>
  73 #include <unistd.h>
  74 #include "hash.h"
  75
  76 #ifndef lint
  77 static const char rcsid[] = "$OpenBSD: parse_netgroup.c,v 1.2 1997/08/18 03:11:35 millert Exp $";
  78 #endif
  79
  80 /*
  81  * Static Variables and functions used by setnetgrent(), getnetgrent() and
  82  * __endnetgrent().
  83  * There are two linked lists:
  84  * - linelist is just used by setnetgrent() to parse the net group file via.
  85  *   parse_netgrp()
  86  * - netgrp is the list of entries for the current netgroup
  87  */
  88 struct linelist {
  89         struct linelist *l_next;        /* Chain ptr. */
  90         int             l_parsed;       /* Flag for cycles */
  91         char            *l_groupname;   /* Name of netgroup */
  92         char            *l_line;        /* Netgroup entrie(s) to be parsed */
  93 };
  94
  95 struct netgrp {
  96         struct netgrp   *ng_next;       /* Chain ptr */
  97         char            *ng_str[3];     /* Field pointers, see below */
  98 };
  99 #define NG_HOST         0       /* Host name */
 100 #define NG_USER         1       /* User name */
 101 #define NG_DOM          2       /* and Domain name */
 102
 103 static struct linelist  *linehead = (struct linelist *)0;
 104 static struct netgrp    *nextgrp = (struct netgrp *)0;
 105 static struct {
 106         struct netgrp   *gr;
 107         char            *grname;
 108 } grouphead = {
 109         (struct netgrp *)0,
 110         (char *)0,
 111 };
 112 static int parse_netgrp();
 113 static struct linelist *read_for_group();
 114 void __setnetgrent(), __endnetgrent();
 115 int __getnetgrent();
 116 extern struct group_entry *gtable[];
 117
 118 /*
 119  * setnetgrent()
 120  * Parse the netgroup file looking for the netgroup and build the list
 121  * of netgrp structures. Let parse_netgrp() and read_for_group() do
 122  * most of the work.
 123  */
 124 void
 125 __setnetgrent(group)
 126         char *group;
 127 {
 128         /* Sanity check */
 129
 130         if (group == NULL || !strlen(group))
 131                 return;
 132
 133         if (grouphead.gr == (struct netgrp *)0 ||
 134                 strcmp(group, grouphead.grname)) {
 135                 __endnetgrent();
 136                 if (parse_netgrp(group))
 137                         __endnetgrent();
 138                 else {
 139                         grouphead.grname = (char *)
 140                                 malloc(strlen(group) + 1);
 141                         strcpy(grouphead.grname, group);
 142                 }
 143         }
 144         nextgrp = grouphead.gr;
 145 }
 146
 147 /*
 148  * Get the next netgroup off the list.
 149  */
 150 int
 151 __getnetgrent(hostp, userp, domp)
 152         char **hostp, **userp, **domp;
 153 {
 154         if (nextgrp) {
 155                 *hostp = nextgrp->ng_str[NG_HOST];
 156                 *userp = nextgrp->ng_str[NG_USER];
 157                 *domp = nextgrp->ng_str[NG_DOM];
 158                 nextgrp = nextgrp->ng_next;
 159                 return (1);
 160         }
 161         return (0);
 162 }
 163
 164 /*
 165  * __endnetgrent() - cleanup
 166  */
 167 void
 168 __endnetgrent()
 169 {
 170         register struct linelist *lp, *olp;
 171         register struct netgrp *gp, *ogp;
 172
 173         lp = linehead;
 174         while (lp) {
 175                 olp = lp;
 176                 lp = lp->l_next;
 177                 free(olp->l_groupname);
 178                 free(olp->l_line);
 179                 free((char *)olp);
 180         }
 181         linehead = (struct linelist *)0;
 182         if (grouphead.grname) {
 183                 free(grouphead.grname);
 184                 grouphead.grname = (char *)0;
 185         }
 186         gp = grouphead.gr;
 187         while (gp) {
 188                 ogp = gp;
 189                 gp = gp->ng_next;
 190                 if (ogp->ng_str[NG_HOST])
 191                         free(ogp->ng_str[NG_HOST]);
 192                 if (ogp->ng_str[NG_USER])
 193                         free(ogp->ng_str[NG_USER]);
 194                 if (ogp->ng_str[NG_DOM])
 195                         free(ogp->ng_str[NG_DOM]);
 196                 free((char *)ogp);
 197         }
 198         grouphead.gr = (struct netgrp *)0;
 199 }
 200
 201 /*
 202  * Parse the netgroup file setting up the linked lists.
 203  */
 204 static int
 205 parse_netgrp(group)
 206         char *group;
 207 {
 208         register char *spos, *epos;
 209         register int len, strpos;
 210 #ifdef DEBUG
 211         register int fields;
 212 #endif
 213         char *pos, *gpos;
 214         struct netgrp *grp;
 215         struct linelist *lp = linehead;
 216
 217         /*
 218          * First, see if the line has already been read in.
 219          */
 220         while (lp) {
 221                 if (!strcmp(group, lp->l_groupname))
 222                         break;
 223                 lp = lp->l_next;
 224         }
 225         if (lp == (struct linelist *)0 &&
 226             (lp = read_for_group(group)) == (struct linelist *)0)
 227                 return (1);
 228         if (lp->l_parsed) {
 229 #ifdef DEBUG
 230                 /*
 231                  * This error message is largely superflous since the
 232                  * code handles the error condition sucessfully, and
 233                  * spewing it out from inside libc can actually hose
 234                  * certain programs.
 235                  */
 236                 fprintf(stderr, "Cycle in netgroup %s\n", lp->l_groupname);
 237 #endif
 238                 return (1);
 239         } else
 240                 lp->l_parsed = 1;
 241         pos = lp->l_line;
 242         /* Watch for null pointer dereferences, dammit! */
 243         while (pos != NULL && *pos != '\0') {
 244                 if (*pos == '(') {
 245                         grp = (struct netgrp *)malloc(sizeof (struct netgrp));
 246                         bzero((char *)grp, sizeof (struct netgrp));
 247                         grp->ng_next = grouphead.gr;
 248                         grouphead.gr = grp;
 249                         pos++;
 250                         gpos = strsep(&pos, ")");
 251 #ifdef DEBUG
 252                         fields = 0;
 253 #endif
 254                         for (strpos = 0; strpos < 3; strpos++) {
 255                                 if ((spos = strsep(&gpos, ","))) {
 256 #ifdef DEBUG
 257                                         fields++;
 258 #endif
 259                                         while (*spos == ' ' || *spos == '\t')
 260                                                 spos++;
 261                                         if ((epos = strpbrk(spos, " \t"))) {
 262                                                 *epos = '\0';
 263                                                 len = epos - spos;
 264                                         } else
 265                                                 len = strlen(spos);
 266                                         if (len > 0) {
 267                                                 grp->ng_str[strpos] =  (char *)
 268                                                         malloc(len + 1);
 269                                                 bcopy(spos, grp->ng_str[strpos],
 270                                                         len + 1);
 271                                         }
 272                                 } else {
 273                                         /*
 274                                          * All other systems I've tested
 275                                          * return NULL for empty netgroup
 276                                          * fields. It's up to user programs
 277                                          * to handle the NULLs appropriately.
 278                                          */
 279                                         grp->ng_str[strpos] = NULL;
 280                                 }
 281                         }
 282 #ifdef DEBUG
 283                         /*
 284                          * Note: on other platforms, malformed netgroup
 285                          * entries are not normally flagged. While we
 286                          * can catch bad entries and report them, we should
 287                          * stay silent by default for compatibility's sake.
 288                          */
 289                         if (fields < 3)
 290                                         fprintf(stderr, "Bad entry (%s%s%s%s%s) in netgroup \"%s\"\n",
 291                                                 grp->ng_str[NG_HOST] == NULL ? "" : grp->ng_str[NG_HOST],
 292                                                 grp->ng_str[NG_USER] == NULL ? "" : ",",
 293                                                 grp->ng_str[NG_USER] == NULL ? "" : grp->ng_str[NG_USER],
 294                                                 grp->ng_str[NG_DOM] == NULL ? "" : ",",
 295                                                 grp->ng_str[NG_DOM] == NULL ? "" : grp->ng_str[NG_DOM],
 296                                                 lp->l_groupname);
 297 #endif
 298                 } else {
 299                         spos = strsep(&pos, ", \t");
 300                         if (parse_netgrp(spos))
 301                                 continue;
 302                 }
 303                 /* Watch for null pointer dereferences, dammit! */
 304                 if (pos != NULL)
 305                         while (*pos == ' ' || *pos == ',' || *pos == '\t')
 306                                 pos++;
 307         }
 308         return (0);
 309 }
 310
 311 /*
 312  * Read the netgroup file and save lines until the line for the netgroup
 313  * is found. Return 1 if eof is encountered.
 314  */
 315 static struct linelist *
 316 read_for_group(group)
 317         char *group;
 318 {
 319         register char *pos, *spos, *linep = NULL, *olinep = NULL;
 320         register int len, olen;
 321         int cont;
 322         struct linelist *lp;
 323         char line[LINSIZ + 1];
 324         char *data = NULL;
 325
 326         data = lookup (gtable, group);
 327         sprintf(line, "%s %s", group, data);
 328         pos = (char *)&line;
 329 #ifdef CANT_HAPPEN
 330         if (*pos == '#')
 331                 continue;
 332 #endif
 333         while (*pos == ' ' || *pos == '\t')
 334                 pos++;
 335         spos = pos;
 336         while (*pos != ' ' && *pos != '\t' && *pos != '\n' &&
 337                 *pos != '\0')
 338                 pos++;
 339         len = pos - spos;
 340         while (*pos == ' ' || *pos == '\t')
 341                 pos++;
 342         if (*pos != '\n' && *pos != '\0') {
 343                 lp = (struct linelist *)malloc(sizeof (*lp));
 344                 lp->l_parsed = 0;
 345                 lp->l_groupname = (char *)malloc(len + 1);
 346                 bcopy(spos, lp->l_groupname, len);
 347                 *(lp->l_groupname + len) = '\0';
 348                 len = strlen(pos);
 349                 olen = 0;
 350                         /*
 351                          * Loop around handling line continuations.
 352                          */
 353                         do {
 354                                 if (*(pos + len - 1) == '\n')
 355                                         len--;
 356                                 if (*(pos + len - 1) == '\\') {
 357                                         len--;
 358                                         cont = 1;
 359                                 } else
 360                                         cont = 0;
 361                                 if (len > 0) {
 362                                         linep = (char *)malloc(olen + len + 1);
 363                                         if (olen > 0) {
 364                                                 bcopy(olinep, linep, olen);
 365                                                 free(olinep);
 366                                         }
 367                                         bcopy(pos, linep + olen, len);
 368                                         olen += len;
 369                                         *(linep + olen) = '\0';
 370                                         olinep = linep;
 371                                 }
 372 #ifdef CANT_HAPPEN
 373                                 if (cont) {
 374                                         if (fgets(line, LINSIZ, netf)) {
 375                                                 pos = line;
 376                                                 len = strlen(pos);
 377                                         } else
 378                                                 cont = 0;
 379                                 }
 380 #endif
 381                         } while (cont);
 382                 lp->l_line = linep;
 383                 lp->l_next = linehead;
 384                 linehead = lp;
 385 #ifdef CANT_HAPPEN
 386                 /*
 387                  * If this is the one we wanted, we are done.
 388                  */
 389                 if (!strcmp(lp->l_groupname, group))
 390 #endif
 391                         return (lp);
 392         }
 393         return ((struct linelist *)0);
 394 }