1 | /* Initgroups handling in nss_db module. |
2 | Copyright (C) 2011-2019 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@gmail.com>. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Library General Public License as |
8 | published by the Free Software Foundation; either version 2 of the |
9 | License, or (at your option) any later version. |
10 | |
11 | The GNU C Library is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
14 | Library General Public License for more details. |
15 | |
16 | You should have received a copy of the GNU Library General Public |
17 | License along with the GNU C Library; see the file COPYING.LIB. If |
18 | not, see <http://www.gnu.org/licenses/>. */ |
19 | |
20 | #include <ctype.h> |
21 | #include <errno.h> |
22 | #include <grp.h> |
23 | #include <limits.h> |
24 | #include <paths.h> |
25 | #include <stdlib.h> |
26 | #include <string.h> |
27 | #include <stdint.h> |
28 | #include <sys/param.h> |
29 | |
30 | #include "nss_db.h" |
31 | |
32 | /* The hashing function we use. */ |
33 | #include "../intl/hash-string.h" |
34 | |
35 | |
36 | enum nss_status |
37 | _nss_db_initgroups_dyn (const char *user, gid_t group, long int *start, |
38 | long int *size, gid_t **groupsp, long int limit, |
39 | int *errnop) |
40 | { |
41 | struct nss_db_map state = { NULL, 0 }; |
42 | enum nss_status status = internal_setent (_PATH_VARDB "group.db" , &state); |
43 | if (status != NSS_STATUS_SUCCESS) |
44 | { |
45 | *errnop = errno; |
46 | return status; |
47 | } |
48 | |
49 | const struct nss_db_header * = state.header; |
50 | int i; |
51 | for (i = 0; i < header->ndbs; ++i) |
52 | if (header->dbs[i].id == ':') |
53 | break; |
54 | if (i == header->ndbs) |
55 | { |
56 | status = NSS_STATUS_UNAVAIL; |
57 | goto out; |
58 | } |
59 | |
60 | const stridx_t *hashtable |
61 | = (const stridx_t *) ((const char *) header |
62 | + header->dbs[i].hashoffset); |
63 | const char *valstrtab = (const char *) header + header->valstroffset; |
64 | size_t userlen = strlen (user); |
65 | uint32_t hashval = __hash_string (user); |
66 | size_t hidx = hashval % header->dbs[i].hashsize; |
67 | size_t hval2 = 1 + hashval % (header->dbs[i].hashsize - 2); |
68 | |
69 | gid_t *groups = *groupsp; |
70 | |
71 | status = NSS_STATUS_NOTFOUND; |
72 | while (hashtable[hidx] != ~((stridx_t) 0)) |
73 | { |
74 | const char *valstr = valstrtab + hashtable[hidx]; |
75 | while (isblank (*valstr)) |
76 | ++valstr; |
77 | |
78 | if (strncmp (valstr, user, userlen) == 0 && isblank (valstr[userlen])) |
79 | { |
80 | valstr += userlen + 1; |
81 | while (isblank (*valstr)) |
82 | ++valstr; |
83 | |
84 | while (*valstr != '\0') |
85 | { |
86 | errno = 0; |
87 | char *endp; |
88 | unsigned long int n = strtoul (valstr, &endp, 10); |
89 | if (*endp != ',' && *endp != '\0') |
90 | break; |
91 | valstr = *endp == '\0' ? endp : endp + 1; |
92 | |
93 | if (n != ULONG_MAX || errno != ERANGE) |
94 | { |
95 | /* Insert the group. */ |
96 | if (*start == *size) |
97 | { |
98 | /* Need a bigger buffer. */ |
99 | if (limit > 0 && *size == limit) |
100 | { |
101 | /* We reached the maximum. */ |
102 | status = NSS_STATUS_SUCCESS; |
103 | goto out; |
104 | } |
105 | |
106 | long int newsize; |
107 | if (limit <= 0) |
108 | newsize = 2 * *size; |
109 | else |
110 | newsize = MIN (limit, 2 * *size); |
111 | |
112 | gid_t *newgroups = realloc (groups, |
113 | newsize * sizeof (*groups)); |
114 | if (newgroups == NULL) |
115 | { |
116 | *errnop = ENOMEM; |
117 | status = NSS_STATUS_TRYAGAIN; |
118 | goto out; |
119 | } |
120 | |
121 | *groupsp = groups = newgroups; |
122 | *size = newsize; |
123 | } |
124 | |
125 | groups[*start] = n; |
126 | *start += 1; |
127 | } |
128 | } |
129 | |
130 | status = NSS_STATUS_SUCCESS; |
131 | break; |
132 | } |
133 | |
134 | if ((hidx += hval2) >= header->dbs[i].hashsize) |
135 | hidx -= header->dbs[i].hashsize; |
136 | } |
137 | |
138 | out: |
139 | internal_endent (&state); |
140 | |
141 | return status; |
142 | } |
143 | |