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
|
/*
* Copyright (C) 2014-2021 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"
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
pid_t dhclient4_pid = 0;
pid_t dhclient6_pid = 0;
typedef struct {
char *version_arg;
char *pid_file;
char *leases_file;
uint8_t generate_duid;
char *duid_leases_file;
pid_t *pid;
ptrdiff_t arg_offset;
} Dhclient;
static const Dhclient dhclient4 = {
.version_arg = "-4",
.pid_file = RUN_DHCLIENT_4_PID_FILE,
.leases_file = RUN_DHCLIENT_4_LEASES_FILE,
.generate_duid = 1,
.pid = &dhclient4_pid,
.arg_offset = offsetof(Bridge, arg_ip_dhcp)
};
static const Dhclient dhclient6 = {
.version_arg = "-6",
.pid_file = RUN_DHCLIENT_6_PID_FILE,
.leases_file = RUN_DHCLIENT_6_LEASES_FILE,
.duid_leases_file = RUN_DHCLIENT_4_LEASES_FILE,
.pid = &dhclient6_pid,
.arg_offset = offsetof(Bridge, arg_ip6_dhcp)
};
static void dhcp_run_dhclient(char *dhclient_path, const Dhclient *client) {
char *argv[256] = {
dhclient_path,
client->version_arg,
"-pf", client->pid_file,
"-lf", client->leases_file,
};
int i = 6;
if (client->generate_duid)
argv[i++] = "-i";
if (client->duid_leases_file) {
argv[i++] = "-df";
argv[i++] = client->duid_leases_file;
}
if (arg_debug)
argv[i++] = "-v";
if (*(uint8_t *)((char *)&cfg.bridge0 + client->arg_offset))
argv[i++] = cfg.bridge0.devsandbox;
if (*(uint8_t *)((char *)&cfg.bridge1 + client->arg_offset))
argv[i++] = cfg.bridge1.devsandbox;
if (*(uint8_t *)((char *)&cfg.bridge2 + client->arg_offset))
argv[i++] = cfg.bridge2.devsandbox;
if (*(uint8_t *)((char *)&cfg.bridge3 + client->arg_offset))
argv[i++] = cfg.bridge3.devsandbox;
sbox_run_v(SBOX_ROOT | SBOX_CAPS_NETWORK | SBOX_CAPS_NET_SERVICE | SBOX_SECCOMP, argv);
}
static pid_t dhcp_read_pidfile(const Dhclient *client) {
// We have to run dhclient as a forking daemon (not pass the -d option),
// because we want to be notified of a successful DHCP lease by the parent process exit.
int tries = 0;
pid_t found = 0;
while (found == 0 && tries < 10) {
if (tries >= 1)
usleep(100000);
FILE *pidfile = fopen(client->pid_file, "re");
if (pidfile) {
long pid;
if (fscanf(pidfile, "%ld", &pid) == 1)
found = (pid_t) pid;
fclose(pidfile);
}
++tries;
}
if (found == 0) {
fprintf(stderr, "Error: Cannot get dhclient %s PID from %s\n",
client->version_arg, client->pid_file);
exit(1);
}
return found;
}
static void dhcp_start_dhclient(char *dhclient_path, const Dhclient *client) {
dhcp_run_dhclient(dhclient_path, client);
*(client->pid) = dhcp_read_pidfile(client);
}
static void dhcp_waitll(const char *ifname) {
sbox_run(SBOX_ROOT | SBOX_CAPS_NETWORK | SBOX_SECCOMP, 3, PATH_FNET, "waitll", ifname);
}
static void dhcp_waitll_all() {
if (cfg.bridge0.arg_ip6_dhcp)
dhcp_waitll(cfg.bridge0.devsandbox);
if (cfg.bridge1.arg_ip6_dhcp)
dhcp_waitll(cfg.bridge1.devsandbox);
if (cfg.bridge2.arg_ip6_dhcp)
dhcp_waitll(cfg.bridge2.devsandbox);
if (cfg.bridge3.arg_ip6_dhcp)
dhcp_waitll(cfg.bridge3.devsandbox);
}
// Temporarily copy dhclient executable under /run/firejail/mnt and start it from there
// in order to recognize it later in firemon and firetools
void dhcp_store_exec(void) {
if (!any_dhcp())
return;
char *dhclient_path = "/sbin/dhclient";
struct stat s;
if (stat(dhclient_path, &s) == -1) {
dhclient_path = "/usr/sbin/dhclient";
if (stat(dhclient_path, &s) == -1) {
fprintf(stderr, "Error: dhclient was not found.\n");
exit(1);
}
}
sbox_run(SBOX_ROOT| SBOX_SECCOMP, 4, PATH_FCOPY, "--follow-link", dhclient_path, RUN_MNT_DIR);
}
void dhcp_start(void) {
if (!any_dhcp())
return;
char *dhclient_path = RUN_MNT_DIR "/dhclient";;
struct stat s;
if (stat(dhclient_path, &s) == -1) {
dhclient_path = "/usr/sbin/dhclient";
if (stat(dhclient_path, &s) == -1) {
fprintf(stderr, "Error: dhclient was not found.\n");
exit(1);
}
}
sbox_run(SBOX_ROOT| SBOX_SECCOMP, 4, PATH_FCOPY, "--follow-link", dhclient_path, RUN_MNT_DIR);
dhclient_path = RUN_MNT_DIR "/dhclient";
EUID_ROOT();
if (mkdir(RUN_DHCLIENT_DIR, 0700))
errExit("mkdir");
if (any_ip_dhcp()) {
dhcp_start_dhclient(dhclient_path, &dhclient4);
if (arg_debug)
printf("Running dhclient -4 in the background as pid %ld\n", (long) dhclient4_pid);
}
if (any_ip6_dhcp()) {
dhcp_waitll_all();
dhcp_start_dhclient(dhclient_path, &dhclient6);
if (arg_debug)
printf("Running dhclient -6 in the background as pid %ld\n", (long) dhclient6_pid);
if (dhclient4_pid == dhclient6_pid) {
fprintf(stderr, "Error: dhclient -4 and -6 have the same PID: %ld\n", (long) dhclient4_pid);
exit(1);
}
}
unlink(dhclient_path);
}
|
