1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
/*
* Copyright (c) 2007-2008 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#include <sys/types.h>
#include <sys/param.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
# include <strings.h>
# endif
#endif /* HAVE_STRING_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#include <pwd.h>
#include <grp.h>
#include "sudo.h"
#include "lbuf.h"
#ifndef lint
__unused static const char rcsid[] = "$Sudo: sudo_nss.c,v 1.6 2008/02/08 13:18:12 millert Exp $";
#endif /* lint */
extern struct sudo_nss sudo_nss_file;
#ifdef HAVE_LDAP
extern struct sudo_nss sudo_nss_ldap;
#endif
#if defined(HAVE_LDAP) && defined(_PATH_NSSWITCH_CONF)
/*
* Read in /etc/nsswitch.conf
* Returns a tail queue of matches.
*/
struct sudo_nss_list *
sudo_read_nss()
{
FILE *fp;
char *cp;
int saw_files = FALSE;
int saw_ldap = FALSE;
int got_match = FALSE;
static struct sudo_nss_list snl;
if ((fp = fopen(_PATH_NSSWITCH_CONF, "r")) == NULL)
goto nomatch;
while ((cp = sudo_parseln(fp)) != NULL) {
/* Skip blank or comment lines */
if (*cp == '\0')
continue;
/* Look for a line starting with "sudoers:" */
if (strncasecmp(cp, "sudoers:", 8) != 0)
continue;
/* Parse line */
for ((cp = strtok(cp + 8, " \t")); cp != NULL; (cp = strtok(NULL, " \t"))) {
if (strcasecmp(cp, "files") == 0 && !saw_files) {
tq_append(&snl, &sudo_nss_file);
got_match = TRUE;
} else if (strcasecmp(cp, "ldap") == 0 && !saw_ldap) {
tq_append(&snl, &sudo_nss_ldap);
got_match = TRUE;
} else if (strcasecmp(cp, "[NOTFOUND=return]") == 0 && got_match) {
/* NOTFOUND affects the most recent entry */
tq_last(&snl)->ret_notfound = TRUE;
got_match = FALSE;
} else
got_match = FALSE;
}
/* Only parse the first "sudoers:" line */
break;
}
fclose(fp);
nomatch:
/* Default to files only if no matches */
if (tq_empty(&snl))
tq_append(&snl, &sudo_nss_file);
return(&snl);
}
#else /* HAVE_LDAP && _PATH_NSSWITCH_CONF */
/*
* Non-nsswitch.conf version with hard-coded order.
*/
struct sudo_nss_list *
sudo_read_nss()
{
static struct sudo_nss_list snl;
# ifdef HAVE_LDAP
tq_append(&snl, &sudo_nss_ldap);
# endif
tq_append(&snl, &sudo_nss_file);
return(&snl);
}
#endif /* HAVE_LDAP && _PATH_NSSWITCH_CONF */
/* Reset user_groups based on passwd entry. */
static void
reset_groups(pw)
struct passwd *pw;
{
#if defined(HAVE_INITGROUPS) && defined(HAVE_GETGROUPS)
if (pw != sudo_user.pw) {
(void) initgroups(pw->pw_name, pw->pw_gid);
if ((user_ngroups = getgroups(0, NULL)) > 0) {
user_groups = erealloc3(user_groups, user_ngroups,
sizeof(GETGROUPS_T));
if (getgroups(user_ngroups, user_groups) < 0)
log_error(USE_ERRNO|MSG_ONLY, "can't get group vector");
} else {
user_ngroups = 0;
efree(user_groups);
}
}
#endif
}
/*
* Print out privileges for the specified user.
* We only get here if the user is allowed to run something on this host.
*/
void
display_privs(snl, pw)
struct sudo_nss_list *snl;
struct passwd *pw;
{
struct sudo_nss *nss;
struct lbuf lbuf;
int count;
/* Reset group vector so group matching works correctly. */
reset_groups(pw);
lbuf_init(&lbuf, NULL, 4, 0);
/* Display defaults from all sources. */
count = 0;
tq_foreach_fwd(snl, nss)
count += nss->display_defaults(nss, pw, &lbuf);
if (count) {
printf("Matching Defaults entries for %s on this host:\n", pw->pw_name);
lbuf_print(&lbuf);
putchar('\n');
}
/* Display Runas and Cmnd-specific defaults from all sources. */
count = 0;
tq_foreach_fwd(snl, nss)
count += nss->display_bound_defaults(nss, pw, &lbuf);
if (count) {
printf("Runas and Command-specific defaults for %s:\n", pw->pw_name);
lbuf_print(&lbuf);
putchar('\n');
}
/* Display privileges from all sources. */
printf("User %s may run the following commands on this host:\n",
pw->pw_name);
tq_foreach_fwd(snl, nss)
(void) nss->display_privs(nss, pw, &lbuf);
if (lbuf.len != 0)
lbuf_print(&lbuf); /* print remainder, if any */
lbuf_destroy(&lbuf);
}
/*
* Check user_cmnd against sudoers and print the matching entry if the
* command is allowed.
*/
int
display_cmnd(snl, pw)
struct sudo_nss_list *snl;
struct passwd *pw;
{
struct sudo_nss *nss;
/* Reset group vector so group matching works correctly. */
reset_groups(pw);
tq_foreach_fwd(snl, nss) {
if (nss->display_cmnd(nss, pw) == 0)
return(0);
}
return(1);
}
|
