2 * initgroups.c - This file is part of the libc-8086/grp package for ELKS,
3 * Copyright (C) 1995, 1996 Nat Friedman <ndf@linux.mit.edu>.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the Free
17 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 * Define GR_SCALE_DYNAMIC if you want grp to dynamically scale its read buffer
30 * so that lines of any length can be used. On very very small systems,
31 * you may want to leave this undefined becasue it will make the grp functions
32 * somewhat larger (because of the inclusion of malloc and the code necessary).
33 * On larger systems, you will want to define this, because grp will _not_
34 * deal with long lines gracefully (they will be skipped).
36 #undef GR_SCALE_DYNAMIC
38 #ifndef GR_SCALE_DYNAMIC
40 * If scaling is not dynamic, the buffers will be statically allocated, and
41 * maximums must be chosen. GR_MAX_LINE_LEN is the maximum number of
42 * characters per line in the group file. GR_MAX_MEMBERS is the maximum
43 * number of members of any given group.
45 #define GR_MAX_LINE_LEN 128
46 /* GR_MAX_MEMBERS = (GR_MAX_LINE_LEN-(24+3+6))/9 */
47 #define GR_MAX_MEMBERS 11
49 #endif /* !GR_SCALE_DYNAMIC */
53 * Define GR_DYNAMIC_GROUP_LIST to make initgroups() dynamically allocate
54 * space for it's GID array before calling setgroups(). This is probably
55 * unnecessary scalage, so it's undefined by default.
57 #undef GR_DYNAMIC_GROUP_LIST
59 #ifndef GR_DYNAMIC_GROUP_LIST
61 * GR_MAX_GROUPS is the size of the static array initgroups() uses for
62 * its static GID array if GR_DYNAMIC_GROUP_LIST isn't defined.
64 #define GR_MAX_GROUPS 64
66 #endif /* !GR_DYNAMIC_GROUP_LIST */
68 int initgroups(__const char *user, gid_t gid)
70 register struct group *group;
72 #ifndef GR_DYNAMIC_GROUP_LIST
73 gid_t group_list[GR_MAX_GROUPS];
75 gid_t *group_list = NULL;
77 register char **tmp_mem;
82 if ((grp_fd = open(bb_path_group_file, O_RDONLY)) < 0)
86 #ifdef GR_DYNAMIC_GROUP_LIST
87 group_list = (gid_t *) realloc(group_list, 1);
89 group_list[num_groups] = gid;
90 #ifndef GR_DYNAMIC_GROUP_LIST
91 while (num_groups < GR_MAX_GROUPS &&
92 (group = __getgrent(grp_fd)) != NULL)
94 while ((group = __getgrent(grp_fd)) != NULL)
97 if (group->gr_gid != gid)
99 tmp_mem = group->gr_mem;
100 while (*tmp_mem != NULL) {
101 if (!strcmp(*tmp_mem, user)) {
103 #ifdef GR_DYNAMIC_GROUP_LIST
104 group_list = (gid_t *) realloc(group_list, num_groups *
107 group_list[num_groups-1] = group->gr_gid;
114 return setgroups(num_groups, group_list);