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
|
/*
* Copyright (C) 2014-2016 Firejail Authors
*
* This file is part of firejail project
*
* 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 of the License, 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.
*/
#include "firejail.h"
#define MAX_READ 4096 // maximum line length
char *restricted_user = NULL;
int restricted_shell(const char *user) {
assert(user);
// open profile file:
char *fname;
if (asprintf(&fname, "%s/login.users", SYSCONFDIR) == -1)
errExit("asprintf");
FILE *fp = fopen(fname, "r");
free(fname);
if (fp == NULL)
return 0;
int lineno = 0;
char buf[MAX_READ];
while (fgets(buf, MAX_READ, fp)) {
lineno++;
// remove empty spaces at the beginning of the line
char *ptr = buf;
while (*ptr == ' ' || *ptr == '\t') {
ptr++;
}
if (*ptr == '\n' || *ptr == '#')
continue;
// parse line
char *usr = ptr;
char *args = strchr(usr, ':');
if (args == NULL) {
fprintf(stderr, "Error: users.conf line %d\n", lineno);
exit(1);
}
*args = '\0';
args++;
ptr = strchr(args, '\n');
if (ptr)
*ptr = '\0';
if (strcmp(user, usr) == 0) {
restricted_user = strdup(user);
// extract program arguments
fullargv[0] = "firejail";
int i;
ptr = args;
for (i = 1; i < MAX_ARGS; i++) {
fullargv[i] = ptr;
while (*ptr != ' ' && *ptr != '\t' && *ptr != '\0')
ptr++;
if (*ptr != '\0') {
*ptr ='\0';
fullargv[i] = strdup(fullargv[i]);
if (fullargv[i] == NULL) {
fprintf(stderr, "Error: cannot allocate memory\n");
exit(1);
}
ptr++;
while (*ptr == ' ' || *ptr == '\t')
ptr++;
if (*ptr != '\0')
continue;
}
fullargv[i] = strdup(fullargv[i]);
fclose(fp);
return i + 1;
}
fprintf(stderr, "Error: too many program arguments in users.conf line %d\n", lineno);
exit(1);
}
}
fclose(fp);
return 0;
}
|