contrib/bind-9.5.2/lib/bind/irs/lcl_gr.c

   1 /*
   2  * Copyright (c) 1989, 1993, 1995
   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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 /*
  35  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  36  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  37  *
  38  * Permission to use, copy, modify, and distribute this software for any
  39  * purpose with or without fee is hereby granted, provided that the above
  40  * copyright notice and this permission notice appear in all copies.
  41  *
  42  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
  43  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  44  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
  45  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  46  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  47  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  48  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  49  */
  50
  51 #if defined(LIBC_SCCS) && !defined(lint)
  52 static const char rcsid[] = "$Id: lcl_gr.c,v 1.3 2005/04/27 04:56:30 sra Exp $";
  53 /* from getgrent.c 8.2 (Berkeley) 3/21/94"; */
  54 /* from BSDI Id: getgrent.c,v 2.8 1996/05/28 18:15:14 bostic Exp $      */
  55 #endif /* LIBC_SCCS and not lint */
  56
  57 /* extern */
  58
  59 #include "port_before.h"
  60
  61 #ifndef WANT_IRS_PW
  62 static int __bind_irs_gr_unneeded;
  63 #else
  64
  65 #include <sys/param.h>
  66 #include <sys/types.h>
  67 #include <netinet/in.h>
  68 #include <arpa/nameser.h>
  69 #include <resolv.h>
  70
  71 #include <errno.h>
  72 #include <fcntl.h>
  73 #include <grp.h>
  74 #include <stdio.h>
  75 #include <stdlib.h>
  76 #include <string.h>
  77 #include <unistd.h>
  78
  79 #include <irs.h>
  80 #include <isc/memcluster.h>
  81
  82 #include "irs_p.h"
  83 #include "lcl_p.h"
  84 #include "irp_p.h"
  85
  86 #include "port_after.h"
  87
  88
  89 /* Types. */
  90
  91 struct pvt {
  92         FILE *          fp;
  93         /*%<
  94          * Need space to store the entries read from the group file.
  95          * The members list also needs space per member, and the
  96          * strings making up the user names must be allocated
  97          * somewhere.  Rather than doing lots of small allocations,
  98          * we keep one buffer and resize it as needed.
  99          */
 100         struct group    group;
 101         size_t          nmemb;          /*%< Malloc'd max index of gr_mem[]. */
 102         char *          membuf;
 103         size_t          membufsize;
 104 };
 105
 106 /* Forward. */
 107
 108 static void             gr_close(struct irs_gr *);
 109 static struct group *   gr_next(struct irs_gr *);
 110 static struct group *   gr_byname(struct irs_gr *, const char *);
 111 static struct group *   gr_bygid(struct irs_gr *, gid_t);
 112 static void             gr_rewind(struct irs_gr *);
 113 static void             gr_minimize(struct irs_gr *);
 114
 115 static int              grstart(struct pvt *);
 116 static char *           grnext(struct pvt *);
 117 static struct group *   grscan(struct irs_gr *, int, gid_t, const char *);
 118
 119 /* Portability. */
 120
 121 #ifndef SEEK_SET
 122 # define SEEK_SET 0
 123 #endif
 124
 125 /* Public. */
 126
 127 struct irs_gr *
 128 irs_lcl_gr(struct irs_acc *this) {
 129         struct irs_gr *gr;
 130         struct pvt *pvt;
 131
 132         UNUSED(this);
 133
 134         if (!(gr = memget(sizeof *gr))) {
 135                 errno = ENOMEM;
 136                 return (NULL);
 137         }
 138         memset(gr, 0x5e, sizeof *gr);
 139         if (!(pvt = memget(sizeof *pvt))) {
 140                 memput(gr, sizeof *gr);
 141                 errno = ENOMEM;
 142                 return (NULL);
 143         }
 144         memset(pvt, 0, sizeof *pvt);
 145         gr->private = pvt;
 146         gr->close = gr_close;
 147         gr->next = gr_next;
 148         gr->byname = gr_byname;
 149         gr->bygid = gr_bygid;
 150         gr->rewind = gr_rewind;
 151         gr->list = make_group_list;
 152         gr->minimize = gr_minimize;
 153         gr->res_get = NULL;
 154         gr->res_set = NULL;
 155         return (gr);
 156 }
 157
 158 /* Methods. */
 159
 160 static void
 161 gr_close(struct irs_gr *this) {
 162         struct pvt *pvt = (struct pvt *)this->private;
 163
 164         if (pvt->fp)
 165                 (void)fclose(pvt->fp);
 166         if (pvt->group.gr_mem)
 167                 free(pvt->group.gr_mem);
 168         if (pvt->membuf)
 169                 free(pvt->membuf);
 170         memput(pvt, sizeof *pvt);
 171         memput(this, sizeof *this);
 172 }
 173
 174 static struct group *
 175 gr_next(struct irs_gr *this) {
 176         struct pvt *pvt = (struct pvt *)this->private;
 177
 178         if (!pvt->fp && !grstart(pvt))
 179                 return (NULL);
 180         return (grscan(this, 0, 0, NULL));
 181 }
 182
 183 static struct group *
 184 gr_byname(struct irs_gr *this, const char *name) {
 185         if (!grstart((struct pvt *)this->private))
 186                 return (NULL);
 187         return (grscan(this, 1, 0, name));
 188 }
 189
 190 static struct group *
 191 gr_bygid(struct irs_gr *this, gid_t gid) {
 192         if (!grstart((struct pvt *)this->private))
 193                 return (NULL);
 194         return (grscan(this, 1, gid, NULL));
 195 }
 196
 197 static void
 198 gr_rewind(struct irs_gr *this) {
 199         (void) grstart((struct pvt *)this->private);
 200 }
 201
 202 static void
 203 gr_minimize(struct irs_gr *this) {
 204         struct pvt *pvt = (struct pvt *)this->private;
 205
 206         if (pvt->fp != NULL) {
 207                 (void)fclose(pvt->fp);
 208                 pvt->fp = NULL;
 209         }
 210 }
 211
 212 /* Private. */
 213
 214 static int
 215 grstart(struct pvt *pvt) {
 216         if (pvt->fp) {
 217                 if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
 218                         return (1);
 219                 (void)fclose(pvt->fp);
 220         }
 221         if (!(pvt->fp = fopen(_PATH_GROUP, "r")))
 222                 return (0);
 223         if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
 224                 fclose(pvt->fp);
 225                 return (0);
 226         }
 227         return (1);
 228 }
 229
 230 #define INITIAL_NMEMB   30                      /*%< about 120 bytes */
 231 #define INITIAL_BUFSIZ  (INITIAL_NMEMB * 8)     /*%< about 240 bytes */
 232 static char *
 233 grnext(struct pvt *pvt) {
 234         char *w, *e;
 235         int ch;
 236
 237         /* Make sure we have a buffer. */
 238         if (pvt->membuf == NULL) {
 239                 pvt->membuf = malloc(INITIAL_BUFSIZ);
 240                 if (pvt->membuf == NULL) {
 241  enomem:
 242                         errno = ENOMEM;
 243                         return (NULL);
 244                 }
 245                 pvt->membufsize = INITIAL_BUFSIZ;
 246         }
 247
 248         /* Read until EOF or EOL. */
 249         w = pvt->membuf;
 250         e = pvt->membuf + pvt->membufsize;
 251         while ((ch = fgetc(pvt->fp)) != EOF && ch != '\n') {
 252                 /* Make sure we have room for this character and a \0. */
 253                 if (w + 1 == e) {
 254                         size_t o = w - pvt->membuf;
 255                         size_t n = pvt->membufsize * 2;
 256                         char *t = realloc(pvt->membuf, n);
 257
 258                         if (t == NULL)
 259                                 goto enomem;
 260                         pvt->membuf = t;
 261                         pvt->membufsize = n;
 262                         w = pvt->membuf + o;
 263                         e = pvt->membuf + pvt->membufsize;
 264                 }
 265                 /* Store it. */
 266                 *w++ = (char)ch;
 267         }
 268
 269         /* Hitting EOF on the first character really does mean EOF. */
 270         if (w == pvt->membuf && ch == EOF) {
 271                 errno = ENOENT;
 272                 return (NULL);
 273         }
 274
 275         /* Last line of /etc/group need not end with \n; we don't care. */
 276         *w = '\0';
 277         return (pvt->membuf);
 278 }
 279
 280 static struct group *
 281 grscan(struct irs_gr *this, int search, gid_t gid, const char *name) {
 282         struct pvt *pvt = (struct pvt *)this->private;
 283         size_t n;
 284         char *bp, **m, *p;
 285
 286         /* Read lines until we find one that matches our search criteria. */
 287         for (;;) {
 288                 if ((bp = grnext(pvt)) == NULL)
 289                         return (NULL);
 290
 291                 /* Optimize the usual case of searching for a name. */
 292                 pvt->group.gr_name = strsep(&bp, ":");
 293                 if (search && name != NULL &&
 294                     strcmp(pvt->group.gr_name, name) != 0)
 295                         continue;
 296                 if (bp == NULL || *bp == '\0')
 297                         goto corrupt;
 298
 299                 /* Skip past the password field. */
 300                 pvt->group.gr_passwd = strsep(&bp, ":");
 301                 if (bp == NULL || *bp == '\0')
 302                         goto corrupt;
 303
 304                 /* Checking for a gid. */
 305                 if ((p = strsep(&bp, ":")) == NULL)
 306                         continue;
 307                 /*
 308                  * Unlike the tests above, the test below is supposed to be
 309                  * testing 'p' and not 'bp', in case you think it's a typo.
 310                  */
 311                 if (p == NULL || *p == '\0') {
 312  corrupt:
 313                         /* warning: corrupted %s file!", _PATH_GROUP */
 314                         continue;
 315                 }
 316                 pvt->group.gr_gid = atoi(p);
 317                 if (search && name == NULL && (gid_t)pvt->group.gr_gid != gid)
 318                         continue;
 319
 320                 /* We want this record. */
 321                 break;
 322         }
 323
 324         /*
 325          * Count commas to find out how many members there might be.
 326          * Note that commas separate, so if there is one comma there
 327          * can be two members (group:*:id:user1,user2).  Add another
 328          * to account for the NULL terminator.  As above, allocate
 329          * largest of INITIAL_NMEMB, or 2*n.
 330          */
 331         n = 1;
 332         if (bp != NULL)
 333                 for (n = 2, p = bp; (p = strpbrk(p, ", ")) != NULL; ++n)
 334                         p += strspn(p, ", ");
 335         if (n > pvt->nmemb || pvt->group.gr_mem == NULL) {
 336                 if ((n *= 2) < INITIAL_NMEMB)
 337                         n = INITIAL_NMEMB;
 338                 if ((m = realloc(pvt->group.gr_mem, n * sizeof *m)) == NULL)
 339                         return (NULL);
 340                 pvt->group.gr_mem = m;
 341                 pvt->nmemb = n;
 342         }
 343
 344         /* Set the name pointers. */
 345         for (m = pvt->group.gr_mem; (p = strsep(&bp, ", ")) != NULL;)
 346                 if (p[0] != '\0')
 347                         *m++ = p;
 348         *m = NULL;
 349
 350         return (&pvt->group);
 351 }
 352
 353 #endif /* WANT_IRS_GR */
 354 /*! \file */