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
|
/*
* SPDX-FileCopyrightText: 1991 , Julianne Frances Haugh
* SPDX-FileCopyrightText: 1991 , Chip Rosenthal
* SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#include "defines.h"
#include <stdio.h>
#include "getdef.h"
#include "prototypes.h"
#ident "$Id$"
/*
* This is now rather generic function which decides if "tty" is listed
* under "cfgin" in config (directly or indirectly). Fallback to default if
* something is bad.
*/
static bool is_listed (const char *cfgin, const char *tty, bool def)
{
FILE *fp;
char buf[1024], *s;
const char *cons;
/*
* If the CONSOLE configuration definition isn't given,
* fallback to default.
*/
cons = getdef_str (cfgin);
if (NULL == cons) {
return def;
}
/*
* If this isn't a filename, then it is a ":" delimited list of
* console devices upon which root logins are allowed.
*/
if (*cons != '/') {
char *pbuf;
strncpy (buf, cons, sizeof (buf));
buf[sizeof (buf) - 1] = '\0';
pbuf = &buf[0];
while ((s = strtok (pbuf, ":")) != NULL) {
if (strcmp (s, tty) == 0) {
return true;
}
pbuf = NULL;
}
return false;
}
/*
* If we can't open the console list, then call everything a
* console - otherwise root will never be allowed to login.
*/
fp = fopen (cons, "r");
if (NULL == fp) {
return def;
}
/*
* See if this tty is listed in the console file.
*/
while (fgets (buf, (int) sizeof (buf), fp) != NULL) {
buf[strlen (buf) - 1] = '\0';
if (strcmp (buf, tty) == 0) {
(void) fclose (fp);
return true;
}
}
/*
* This tty isn't a console.
*/
(void) fclose (fp);
return false;
}
/*
* console - return 1 if the "tty" is a console device, else 0.
*
* Note - we need to take extreme care here to avoid locking out root logins
* if something goes awry. That's why we do things like call everything a
* console if the consoles file can't be opened. Because of this, we must
* warn the user to protect against the remove of the consoles file since
* that would allow an unauthorized root login.
*/
bool console (const char *tty)
{
if (strncmp (tty, "/dev/", 5) == 0) {
tty += 5;
}
return is_listed ("CONSOLE", tty, true);
}
|
