libutil/gr_util.c

   1 /*-
   2  * Copyright (c) 2008 Sean C. Farley <scf@FreeBSD.org>
   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  *    without modification, immediately at the beginning of the file.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31
  32 #include <grp.h>
  33 #include <inttypes.h>
  34 #include <libutil.h>
  35 #include <stdbool.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <string.h>
  39
  40 struct group_storage {
  41         struct group     gr;
  42         char            *members[];
  43 };
  44
  45 static const char group_line_format[] = "%s:%s:%ju:";
  46
  47 /*
  48  * Compares two struct group's.
  49  */
  50 int
  51 gr_equal(const struct group *gr1, const struct group *gr2)
  52 {
  53         int gr1_ndx;
  54         int gr2_ndx;
  55         bool found;
  56
  57         /* Check that the non-member information is the same. */
  58         if (gr1->gr_name == NULL || gr2->gr_name == NULL) {
  59                 if (gr1->gr_name != gr2->gr_name)
  60                         return (false);
  61         } else if (strcmp(gr1->gr_name, gr2->gr_name) != 0)
  62                 return (false);
  63         if (gr1->gr_passwd == NULL || gr2->gr_passwd == NULL) {
  64                 if (gr1->gr_passwd != gr2->gr_passwd)
  65                         return (false);
  66         } else if (strcmp(gr1->gr_passwd, gr2->gr_passwd) != 0)
  67                 return (false);
  68         if (gr1->gr_gid != gr2->gr_gid)
  69                 return (false);
  70
  71         /* Check all members in both groups. */
  72         if (gr1->gr_mem == NULL || gr2->gr_mem == NULL) {
  73                 if (gr1->gr_mem != gr2->gr_mem)
  74                         return (false);
  75         } else {
  76                 for (found = false, gr1_ndx = 0; gr1->gr_mem[gr1_ndx] != NULL;
  77                     gr1_ndx++) {
  78                         for (gr2_ndx = 0; gr2->gr_mem[gr2_ndx] != NULL;
  79                             gr2_ndx++)
  80                                 if (strcmp(gr1->gr_mem[gr1_ndx],
  81                                     gr2->gr_mem[gr2_ndx]) == 0) {
  82                                         found = true;
  83                                         break;
  84                                 }
  85                         if (!found)
  86                                 return (false);
  87                 }
  88
  89                 /* Check that group2 does not have more members than group1. */
  90                 if (gr2->gr_mem[gr1_ndx] != NULL)
  91                         return (false);
  92         }
  93
  94         return (true);
  95 }
  96
  97 /*
  98  * Make a group line out of a struct group.
  99  */
 100 char *
 101 gr_make(const struct group *gr)
 102 {
 103         char *line;
 104         size_t line_size;
 105         int ndx;
 106
 107         /* Calculate the length of the group line. */
 108         line_size = snprintf(NULL, 0, group_line_format, gr->gr_name,
 109             gr->gr_passwd, (uintmax_t)gr->gr_gid) + 1;
 110         if (gr->gr_mem != NULL) {
 111                 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++)
 112                         line_size += strlen(gr->gr_mem[ndx]) + 1;
 113                 if (ndx > 0)
 114                         line_size--;
 115         }
 116
 117         /* Create the group line and fill it. */
 118         if ((line = malloc(line_size)) == NULL)
 119                 return (NULL);
 120         line_size = snprintf(line, line_size, group_line_format, gr->gr_name,
 121             gr->gr_passwd, (uintmax_t)gr->gr_gid);
 122         if (gr->gr_mem != NULL)
 123                 for (ndx = 0; gr->gr_mem[ndx] != NULL; ndx++) {
 124                         strcat(line, gr->gr_mem[ndx]);
 125                         if (gr->gr_mem[ndx + 1] != NULL)
 126                                 strcat(line, ",");
 127                 }
 128
 129         return (line);
 130 }
 131
 132 /*
 133  * Duplicate a struct group.
 134  */
 135 struct group *
 136 gr_dup(const struct group *gr)
 137 {
 138         char *dst;
 139         size_t len;
 140         struct group_storage *gs;
 141         int ndx;
 142         int num_mem;
 143
 144         /* Calculate size of the group. */
 145         len = sizeof(*gs);
 146         if (gr->gr_name != NULL)
 147                 len += strlen(gr->gr_name) + 1;
 148         if (gr->gr_passwd != NULL)
 149                 len += strlen(gr->gr_passwd) + 1;
 150         if (gr->gr_mem != NULL) {
 151                 for (num_mem = 0; gr->gr_mem[num_mem] != NULL; num_mem++)
 152                         len += strlen(gr->gr_mem[num_mem]) + 1;
 153                 len += (num_mem + 1) * sizeof(*gr->gr_mem);
 154         } else
 155                 num_mem = -1;
 156
 157         /* Create new group and copy old group into it. */
 158         if ((gs = calloc(1, len)) == NULL)
 159                 return (NULL);
 160         dst = (char *)&gs->members[num_mem + 1];
 161         if (gr->gr_name != NULL) {
 162                 gs->gr.gr_name = dst;
 163                 dst = stpcpy(gs->gr.gr_name, gr->gr_name) + 1;
 164         }
 165         if (gr->gr_passwd != NULL) {
 166                 gs->gr.gr_passwd = dst;
 167                 dst = stpcpy(gs->gr.gr_passwd, gr->gr_passwd) + 1;
 168         }
 169         gs->gr.gr_gid = gr->gr_gid;
 170         if (gr->gr_mem != NULL) {
 171                 gs->gr.gr_mem = gs->members;
 172                 for (ndx = 0; ndx < num_mem; ndx++) {
 173                         gs->gr.gr_mem[ndx] = dst;
 174                         dst = stpcpy(gs->gr.gr_mem[ndx], gr->gr_mem[ndx]) + 1;
 175                 }
 176                 gs->gr.gr_mem[ndx] = NULL;
 177         }
 178
 179         return (&gs->gr);
 180 }
 181
 182 /*
 183  * Scan a line and place it into a group structure.
 184  */
 185 static bool
 186 __gr_scan(char *line, struct group *gr)
 187 {
 188         char *loc;
 189         int ndx;
 190
 191         /* Assign non-member information to structure. */
 192         gr->gr_name = line;
 193         if ((loc = strchr(line, ':')) == NULL)
 194                 return (false);
 195         *loc = '\0';
 196         gr->gr_passwd = loc + 1;
 197         if (*gr->gr_passwd == ':')
 198                 *gr->gr_passwd = '\0';
 199         else {
 200                 if ((loc = strchr(loc + 1, ':')) == NULL)
 201                         return (false);
 202                 *loc = '\0';
 203         }
 204         if (sscanf(loc + 1, "%u", &gr->gr_gid) != 1)
 205                 return (false);
 206
 207         /* Assign member information to structure. */
 208         if ((loc = strchr(loc + 1, ':')) == NULL)
 209                 return (false);
 210         line = loc + 1;
 211         gr->gr_mem = NULL;
 212         ndx = 0;
 213         do {
 214                 gr->gr_mem = reallocf(gr->gr_mem, sizeof(*gr->gr_mem) *
 215                     (ndx + 1));
 216                 if (gr->gr_mem == NULL)
 217                         return (false);
 218
 219                 /* Skip locations without members (i.e., empty string). */
 220                 do {
 221                         gr->gr_mem[ndx] = strsep(&line, ",");
 222                 } while (gr->gr_mem[ndx] != NULL && *gr->gr_mem[ndx] == '\0');
 223         } while (gr->gr_mem[ndx++] != NULL);
 224
 225         return (true);
 226 }
 227
 228 /*
 229  * Create a struct group from a line.
 230  */
 231 struct group *
 232 gr_scan(const char *line)
 233 {
 234         struct group gr;
 235         char *line_copy;
 236         struct group *new_gr;
 237
 238         if ((line_copy = strdup(line)) == NULL)
 239                 return (NULL);
 240         if (!__gr_scan(line_copy, &gr)) {
 241                 free(line_copy);
 242                 return (NULL);
 243         }
 244         new_gr = gr_dup(&gr);
 245         free(line_copy);
 246         if (gr.gr_mem != NULL)
 247                 free(gr.gr_mem);
 248
 249         return (new_gr);
 250 }