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
|
/* idcache.c -- map user and group IDs, cached for speed
Copyright (C) 1985, 1988, 1989, 1990, 1997, 1998, 2003, 2005 Free
Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <pwd.h>
#include <grp.h>
#include <unistd.h>
#include "xalloc.h"
#ifdef __DJGPP__
static char digits[] = "0123456789";
#endif
struct userid
{
union
{
uid_t u;
gid_t g;
} id;
char *name;
struct userid *next;
};
static struct userid *user_alist;
/* The members of this list have names not in the local passwd file. */
static struct userid *nouser_alist;
/* Translate UID to a login name, with cache, or NULL if unresolved. */
char *
getuser (uid_t uid)
{
register struct userid *tail;
struct passwd *pwent;
for (tail = user_alist; tail; tail = tail->next)
if (tail->id.u == uid)
return tail->name;
pwent = getpwuid (uid);
tail = xmalloc (sizeof *tail);
tail->id.u = uid;
tail->name = pwent ? xstrdup (pwent->pw_name) : NULL;
/* Add to the head of the list, so most recently used is first. */
tail->next = user_alist;
user_alist = tail;
return tail->name;
}
/* Translate USER to a UID, with cache.
Return NULL if there is no such user.
(We also cache which user names have no passwd entry,
so we don't keep looking them up.) */
uid_t *
getuidbyname (const char *user)
{
register struct userid *tail;
struct passwd *pwent;
for (tail = user_alist; tail; tail = tail->next)
/* Avoid a function call for the most common case. */
if (*tail->name == *user && !strcmp (tail->name, user))
return &tail->id.u;
for (tail = nouser_alist; tail; tail = tail->next)
/* Avoid a function call for the most common case. */
if (*tail->name == *user && !strcmp (tail->name, user))
return 0;
pwent = getpwnam (user);
#ifdef __DJGPP__
/* We need to pretend to be the user USER, to make
pwd functions know about an arbitrary user name. */
if (!pwent && strspn (user, digits) < strlen (user))
{
setenv ("USER", user, 1);
pwent = getpwnam (user); /* now it will succeed */
}
#endif
tail = xmalloc (sizeof *tail);
tail->name = xstrdup (user);
/* Add to the head of the list, so most recently used is first. */
if (pwent)
{
tail->id.u = pwent->pw_uid;
tail->next = user_alist;
user_alist = tail;
return &tail->id.u;
}
tail->next = nouser_alist;
nouser_alist = tail;
return 0;
}
/* Use the same struct as for userids. */
static struct userid *group_alist;
static struct userid *nogroup_alist;
/* Translate GID to a group name, with cache, or NULL if unresolved. */
char *
getgroup (gid_t gid)
{
register struct userid *tail;
struct group *grent;
for (tail = group_alist; tail; tail = tail->next)
if (tail->id.g == gid)
return tail->name;
grent = getgrgid (gid);
tail = xmalloc (sizeof *tail);
tail->id.g = gid;
tail->name = grent ? xstrdup (grent->gr_name) : NULL;
/* Add to the head of the list, so most recently used is first. */
tail->next = group_alist;
group_alist = tail;
return tail->name;
}
/* Translate GROUP to a GID, with cache.
Return NULL if there is no such group.
(We also cache which group names have no group entry,
so we don't keep looking them up.) */
gid_t *
getgidbyname (const char *group)
{
register struct userid *tail;
struct group *grent;
for (tail = group_alist; tail; tail = tail->next)
/* Avoid a function call for the most common case. */
if (*tail->name == *group && !strcmp (tail->name, group))
return &tail->id.g;
for (tail = nogroup_alist; tail; tail = tail->next)
/* Avoid a function call for the most common case. */
if (*tail->name == *group && !strcmp (tail->name, group))
return 0;
grent = getgrnam (group);
#ifdef __DJGPP__
/* We need to pretend to belong to group GROUP, to make
grp functions know about any arbitrary group name. */
if (!grent && strspn (group, digits) < strlen (group))
{
setenv ("GROUP", group, 1);
grent = getgrnam (group); /* now it will succeed */
}
#endif
tail = xmalloc (sizeof *tail);
tail->name = xstrdup (group);
/* Add to the head of the list, so most recently used is first. */
if (grent)
{
tail->id.g = grent->gr_gid;
tail->next = group_alist;
group_alist = tail;
return &tail->id.g;
}
tail->next = nogroup_alist;
nogroup_alist = tail;
return 0;
}
|
