-
-
Notifications
You must be signed in to change notification settings - Fork 389
/
flatpak-builtins-enter.c
337 lines (281 loc) · 10.7 KB
/
flatpak-builtins-enter.c
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
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
/* vi:set et sw=2 sts=2 cin cino=t0,f0,(0,{s,>2s,n-s,^-s,e-s:
* Copyright © 2014 Red Hat, Inc
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http:https://www.gnu.org/licenses/>.
*
* Authors:
* Alexander Larsson <[email protected]>
*/
#include "config.h"
#include <locale.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <glib/gi18n.h>
#include "libglnx.h"
#include "flatpak-builtins.h"
#include "flatpak-utils-private.h"
#include "flatpak-dbus-generated.h"
#include "flatpak-run-private.h"
#include "flatpak-instance.h"
#include <sys/capability.h>
static GOptionEntry options[] = {
{ NULL }
};
static void
drop_all_caps (void)
{
struct __user_cap_header_struct hdr = { _LINUX_CAPABILITY_VERSION_3, 0 };
struct __user_cap_data_struct data[2] = { { 0 } };
capset (&hdr, data);
}
gboolean
flatpak_builtin_enter (int argc,
char **argv,
GCancellable *cancellable,
GError **error)
{
g_autoptr(GOptionContext) context = NULL;
int rest_argv_start, rest_argc;
const char *ns_name[] = { "user_base", "ipc", "net", "pid", "mnt", "user" };
int ns_fd[G_N_ELEMENTS (ns_name)];
ino_t user_base_ino = 0;
char *pid_s;
int pid, i;
g_autofree char *environment_path = NULL;
g_autoptr(GPtrArray) argv_array = NULL;
g_autoptr(GPtrArray) envp_array = NULL;
g_autofree char *environment = NULL;
gsize environment_len;
char *e;
g_autofree char *pulse_path = NULL;
g_autofree char *session_bus_path = NULL;
g_autofree char *xdg_runtime_dir = NULL;
g_autofree char *stat_path = NULL;
g_autofree char *root_path = NULL;
g_autofree char *root_link = NULL;
g_autofree char *cwd_path = NULL;
g_autofree char *cwd_link = NULL;
int status;
struct stat stat_buf;
uid_t uid;
gid_t gid;
g_autoptr(GPtrArray) instances = NULL;
int j;
context = g_option_context_new (_("INSTANCE COMMAND [ARGUMENT…] - Run a command inside a running sandbox"));
g_option_context_set_translation_domain (context, GETTEXT_PACKAGE);
rest_argc = 0;
rest_argv_start = 0;
for (i = 1; i < argc; i++)
{
/* The non-option is the command, take it out of the arguments */
if (argv[i][0] != '-')
{
rest_argv_start = i;
rest_argc = argc - i;
argc = i;
break;
}
}
if (!flatpak_option_context_parse (context, options, &argc, &argv, FLATPAK_BUILTIN_FLAG_NO_DIR, NULL, cancellable, error))
return FALSE;
if (rest_argc < 2)
{
usage_error (context, _("INSTANCE and COMMAND must be specified"), error);
return FALSE;
}
/* If this wasn't true, rest_argc would still be 0 */
g_assert (rest_argv_start >= 1);
pid_s = argv[rest_argv_start];
pid = atoi (pid_s);
/* Check to see if it matches some running instance, otherwise use
as pid if it looks as a number. */
instances = flatpak_instance_get_all ();
for (j = 0; j < instances->len; j++)
{
FlatpakInstance *instance = (FlatpakInstance *) g_ptr_array_index (instances, j);
if (pid == flatpak_instance_get_pid (instance) ||
g_strcmp0 (pid_s, flatpak_instance_get_app (instance)) == 0 ||
strcmp (pid_s, flatpak_instance_get_id (instance)) == 0)
{
pid = flatpak_instance_get_child_pid (instance);
break;
}
}
if (pid <= 0)
return flatpak_fail (error, _("%s is neither a pid nor an application or instance ID"), pid_s);
stat_path = g_strdup_printf ("/proc/%d/root", pid);
if (stat (stat_path, &stat_buf))
{
if (errno == EACCES)
return flatpak_fail (error, _("entering not supported (need unprivileged user namespaces, or sudo -E)"));
return flatpak_fail (error, _("No such pid %s"), pid_s);
}
uid = stat_buf.st_uid;
gid = stat_buf.st_gid;
environment_path = g_strdup_printf ("/proc/%d/environ", pid);
if (!g_file_get_contents (environment_path, &environment, &environment_len, error))
return FALSE;
cwd_path = g_strdup_printf ("/proc/%d/cwd", pid);
cwd_link = glnx_readlinkat_malloc (-1, cwd_path, NULL, error);
if (cwd_link == NULL)
return glnx_prefix_error (error, _("Can't read cwd"));
root_path = g_strdup_printf ("/proc/%d/root", pid);
root_link = glnx_readlinkat_malloc (-1, root_path, NULL, error);
if (root_link == NULL)
return glnx_prefix_error (error, _("Can't read root"));
for (i = 0; i < G_N_ELEMENTS (ns_name); i++)
{
g_autofree char *path = NULL;
g_autofree char *self_path = NULL;
struct stat path_stat, self_path_stat;
if (strcmp (ns_name[i], "user_base") == 0)
{
/* We could use the NS_GET_USERNS ioctl instead of the .userns bind hack, but that would require >= 4.9 kernel */
path = g_strdup_printf ("%s/run/.userns", root_path);
self_path = g_strdup ("/proc/self/ns/user");
}
else
{
path = g_strdup_printf ("/proc/%d/ns/%s", pid, ns_name[i]);
self_path = g_strdup_printf ("/proc/self/ns/%s", ns_name[i]);
}
if (stat (path, &path_stat) != 0)
{
if (errno == ENOENT)
{
/* If for whatever reason the namespace doesn't exist, skip it */
ns_fd[i] = -1;
continue;
}
return glnx_prefix_error (error, _("Invalid %s namespace for pid %d"), ns_name[i], pid);
}
if (strcmp (ns_name[i], "user") == 0 && path_stat.st_ino == user_base_ino)
{
/* bubblewrap did not create an intermediate user namespace */
ns_fd[i] = -1;
continue;
}
if (stat (self_path, &self_path_stat) != 0)
return glnx_prefix_error (error, _("Invalid %s namespace for self"), ns_name[i]);
if (self_path_stat.st_ino == path_stat.st_ino)
{
/* No need to setns to the same namespace, it will only fail */
ns_fd[i] = -1;
continue;
}
if (strcmp (ns_name[i], "user_base") == 0)
user_base_ino = path_stat.st_ino;
ns_fd[i] = open (path, O_RDONLY);
if (ns_fd[i] == -1)
return flatpak_fail (error, _("Can't open %s namespace: %s"), ns_name[i], g_strerror (errno));
}
for (i = 0; i < G_N_ELEMENTS (ns_fd); i++)
{
if (ns_fd[i] != -1)
{
if (setns (ns_fd[i], 0) == -1)
{
if (errno == EPERM)
return flatpak_fail (error, _("entering not supported (need unprivileged user namespaces)"));
return flatpak_fail (error, _("Can't enter %s namespace: %s"), ns_name[i], g_strerror (errno));
}
close (ns_fd[i]);
}
}
if (chdir (cwd_link))
return flatpak_fail (error, _("Can't chdir"));
if (chroot (root_link))
return flatpak_fail (error, _("Can't chroot"));
if (setgid (gid))
return flatpak_fail (error, _("Can't switch gid"));
if (setuid (uid))
return flatpak_fail (error, _("Can't switch uid"));
drop_all_caps ();
envp_array = g_ptr_array_new_with_free_func (g_free);
for (e = environment; e < environment + environment_len; e = e + strlen (e) + 1)
{
if (*e != 0 &&
!g_str_has_prefix (e, "PULSE_SERVER=") &&
!g_str_has_prefix (e, "PULSE_CLIENTCONFIG=") &&
!g_str_has_prefix (e, "XDG_RUNTIME_DIR=") &&
!g_str_has_prefix (e, "DBUS_SYSTEM_BUS_ADDRESS=") &&
!g_str_has_prefix (e, "DBUS_SESSION_BUS_ADDRESS="))
{
if (g_str_has_prefix (e, "_LD_LIBRARY_PATH="))
e++;
g_ptr_array_add (envp_array, g_strdup (e));
}
}
xdg_runtime_dir = g_strdup_printf ("/run/user/%d", uid);
g_ptr_array_add (envp_array, g_strdup_printf ("XDG_RUNTIME_DIR=%s", xdg_runtime_dir));
pulse_path = g_strdup_printf ("/run/user/%d/pulse/native", uid);
if (g_file_test (pulse_path, G_FILE_TEST_EXISTS))
{
g_ptr_array_add (envp_array, g_strdup_printf ("PULSE_SERVER=unix:%s", pulse_path));
g_ptr_array_add (envp_array, g_strdup_printf ("PULSE_CLIENTCONFIG=/run/user/%d/pulse/config", uid));
}
session_bus_path = g_strdup_printf ("/run/user/%d/bus", uid);
if (g_file_test (session_bus_path, G_FILE_TEST_EXISTS))
g_ptr_array_add (envp_array, g_strdup_printf ("DBUS_SESSION_BUS_ADDRESS=unix:path=%s", session_bus_path));
if (g_file_test ("/run/dbus/system_bus_socket", G_FILE_TEST_EXISTS))
g_ptr_array_add (envp_array, g_strdup ("DBUS_SYSTEM_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket"));
if (getenv ("TERM"))
g_ptr_array_add (envp_array, g_strdup_printf ("TERM=%s", getenv ("TERM")));
g_ptr_array_add (envp_array, NULL);
argv_array = g_ptr_array_new_with_free_func (g_free);
for (i = 1; i < rest_argc; i++)
g_ptr_array_add (argv_array, g_strdup (argv[rest_argv_start + i]));
g_ptr_array_add (argv_array, NULL);
signal (SIGINT, SIG_IGN);
if (!g_spawn_sync (NULL, (char **) argv_array->pdata, (char **) envp_array->pdata,
G_SPAWN_SEARCH_PATH_FROM_ENVP | G_SPAWN_CHILD_INHERITS_STDIN,
NULL, NULL,
NULL, NULL,
&status, error))
return FALSE;
exit (status);
}
gboolean
flatpak_complete_enter (FlatpakCompletion *completion)
{
g_autoptr(GOptionContext) context = NULL;
g_autoptr(GPtrArray) instances = NULL;
int i;
context = g_option_context_new ("");
if (!flatpak_option_context_parse (context, options, &completion->argc, &completion->argv, FLATPAK_BUILTIN_FLAG_NO_DIR, NULL, NULL, NULL))
return FALSE;
switch (completion->argc)
{
case 0:
case 1:
flatpak_complete_options (completion, global_entries);
flatpak_complete_options (completion, options);
instances = flatpak_instance_get_all ();
for (i = 0; i < instances->len; i++)
{
FlatpakInstance *instance = (FlatpakInstance *) g_ptr_array_index (instances, i);
const char *app_name = flatpak_instance_get_app (instance);
if (app_name)
flatpak_complete_word (completion, "%s ", app_name);
flatpak_complete_word (completion, "%s ", flatpak_instance_get_id (instance));
}
break;
default:
break;
}
return TRUE;
}