]> git.ipfire.org Git - thirdparty/qemu.git/blame - os-posix.c
block: Avoid memleak on qcow2 image info failure
[thirdparty/qemu.git] / os-posix.c
CommitLineData
86b645e7
JS
1/*
2 * os-posix.c
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2010 Red Hat, Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
d38ea87a 26#include "qemu/osdep.h"
8d963e6a 27#include <sys/wait.h>
8847cfe8 28#include <pwd.h>
cc4662f9 29#include <grp.h>
6170540b 30#include <libgen.h>
86b645e7 31
a8d25326 32#include "qemu-common.h"
86b645e7 33/* Needed early for CONFIG_BSD etc. */
59a5264b
JS
34#include "net/slirp.h"
35#include "qemu-options.h"
f853ac66 36#include "qemu/error-report.h"
96c33a45 37#include "qemu/log.h"
54d31236 38#include "sysemu/runstate.h"
f348b6d1 39#include "qemu/cutils.h"
86b645e7 40
ce798cf2
JS
41#ifdef CONFIG_LINUX
42#include <sys/prctl.h>
949d31e6
JS
43#endif
44
2c42f1e8
IJ
45/*
46 * Must set all three of these at once.
47 * Legal combinations are unset by name by uid
48 */
49static struct passwd *user_pwd; /* NULL non-NULL NULL */
50static uid_t user_uid = (uid_t)-1; /* -1 -1 >=0 */
51static gid_t user_gid = (gid_t)-1; /* -1 -1 >=0 */
52
0766379d 53static const char *chroot_dir;
eb505be1 54static int daemonize;
0be5e436 55static int daemon_pipe;
8847cfe8 56
fe98ac14 57void os_setup_early_signal_handling(void)
86b645e7
JS
58{
59 struct sigaction act;
60 sigfillset(&act.sa_mask);
61 act.sa_flags = 0;
62 act.sa_handler = SIG_IGN;
63 sigaction(SIGPIPE, &act, NULL);
64}
8d963e6a 65
f64622c4 66static void termsig_handler(int signal, siginfo_t *info, void *c)
8d963e6a 67{
f64622c4 68 qemu_system_killed(info->si_signo, info->si_pid);
8d963e6a
JS
69}
70
8d963e6a
JS
71void os_setup_signal_handling(void)
72{
73 struct sigaction act;
74
75 memset(&act, 0, sizeof(act));
f64622c4
GN
76 act.sa_sigaction = termsig_handler;
77 act.sa_flags = SA_SIGINFO;
8d963e6a
JS
78 sigaction(SIGINT, &act, NULL);
79 sigaction(SIGHUP, &act, NULL);
80 sigaction(SIGTERM, &act, NULL);
8d963e6a 81}
6170540b 82
6dd2dace
MAL
83/*
84 * Find a likely location for support files using the location of the binary.
85 * When running from the build tree this will be "$bindir/../pc-bios".
86 * Otherwise, this is CONFIG_QEMU_DATADIR.
87 */
10f5bff6 88char *os_find_datadir(void)
6170540b 89{
6dd2dace
MAL
90 g_autofree char *exec_dir = NULL;
91 g_autofree char *dir = NULL;
6170540b 92
10f5bff6 93 exec_dir = qemu_get_exec_dir();
6dd2dace
MAL
94 g_return_val_if_fail(exec_dir != NULL, NULL);
95
96 dir = g_build_filename(exec_dir, "..", "pc-bios", NULL);
97 if (g_file_test(dir, G_FILE_TEST_IS_DIR)) {
98 return g_steal_pointer(&dir);
6170540b
JS
99 }
100
6dd2dace 101 return g_strdup(CONFIG_QEMU_DATADIR);
6170540b 102}
59a5264b 103
ce798cf2
JS
104void os_set_proc_name(const char *s)
105{
106#if defined(PR_SET_NAME)
107 char name[16];
108 if (!s)
109 return;
3eadc68e 110 pstrcpy(name, sizeof(name), s);
ce798cf2
JS
111 /* Could rewrite argv[0] too, but that's a bit more complicated.
112 This simple way is enough for `top'. */
113 if (prctl(PR_SET_NAME, name)) {
a7aaec14 114 error_report("unable to change process name: %s", strerror(errno));
ce798cf2
JS
115 exit(1);
116 }
117#else
22cd4f48 118 error_report("Change of process name not supported by your OS");
ce798cf2
JS
119 exit(1);
120#endif
121}
122
2c42f1e8
IJ
123
124static bool os_parse_runas_uid_gid(const char *optarg)
125{
126 unsigned long lv;
127 const char *ep;
128 uid_t got_uid;
129 gid_t got_gid;
130 int rc;
131
132 rc = qemu_strtoul(optarg, &ep, 0, &lv);
133 got_uid = lv; /* overflow here is ID in C99 */
134 if (rc || *ep != ':' || got_uid != lv || got_uid == (uid_t)-1) {
135 return false;
136 }
137
138 rc = qemu_strtoul(ep + 1, 0, 0, &lv);
139 got_gid = lv; /* overflow here is ID in C99 */
140 if (rc || got_gid != lv || got_gid == (gid_t)-1) {
141 return false;
142 }
143
144 user_pwd = NULL;
145 user_uid = got_uid;
146 user_gid = got_gid;
147 return true;
148}
149
59a5264b
JS
150/*
151 * Parse OS specific command line options.
152 * return 0 if option handled, -1 otherwise
153 */
1217d6ca 154int os_parse_cmd_args(int index, const char *optarg)
59a5264b
JS
155{
156 switch (index) {
8847cfe8
JS
157 case QEMU_OPTION_runas:
158 user_pwd = getpwnam(optarg);
2c42f1e8
IJ
159 if (user_pwd) {
160 user_uid = -1;
161 user_gid = -1;
162 } else if (!os_parse_runas_uid_gid(optarg)) {
163 error_report("User \"%s\" doesn't exist"
164 " (and is not <uid>:<gid>)",
165 optarg);
8847cfe8
JS
166 exit(1);
167 }
168 break;
0766379d
JS
169 case QEMU_OPTION_chroot:
170 chroot_dir = optarg;
171 break;
eb505be1
JS
172 case QEMU_OPTION_daemonize:
173 daemonize = 1;
174 break;
70678b82
AL
175#if defined(CONFIG_LINUX)
176 case QEMU_OPTION_enablefips:
177 fips_set_state(true);
178 break;
179#endif
1217d6ca
TH
180 default:
181 return -1;
59a5264b 182 }
1217d6ca
TH
183
184 return 0;
59a5264b 185}
8847cfe8 186
e06eb601 187static void change_process_uid(void)
8847cfe8 188{
2c42f1e8
IJ
189 assert((user_uid == (uid_t)-1) || user_pwd == NULL);
190 assert((user_uid == (uid_t)-1) ==
191 (user_gid == (gid_t)-1));
192
193 if (user_pwd || user_uid != (uid_t)-1) {
194 gid_t intended_gid = user_pwd ? user_pwd->pw_gid : user_gid;
195 uid_t intended_uid = user_pwd ? user_pwd->pw_uid : user_uid;
196 if (setgid(intended_gid) < 0) {
197 error_report("Failed to setgid(%d)", intended_gid);
8847cfe8
JS
198 exit(1);
199 }
2c42f1e8
IJ
200 if (user_pwd) {
201 if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
202 error_report("Failed to initgroups(\"%s\", %d)",
203 user_pwd->pw_name, user_pwd->pw_gid);
204 exit(1);
205 }
206 } else {
207 if (setgroups(1, &user_gid) < 0) {
208 error_report("Failed to setgroups(1, [%d])",
209 user_gid);
210 exit(1);
211 }
cc4662f9 212 }
2c42f1e8
IJ
213 if (setuid(intended_uid) < 0) {
214 error_report("Failed to setuid(%d)", intended_uid);
8847cfe8
JS
215 exit(1);
216 }
217 if (setuid(0) != -1) {
f0a2171b 218 error_report("Dropping privileges failed");
8847cfe8
JS
219 exit(1);
220 }
221 }
222}
0766379d 223
e06eb601 224static void change_root(void)
0766379d
JS
225{
226 if (chroot_dir) {
227 if (chroot(chroot_dir) < 0) {
22cd4f48 228 error_report("chroot failed");
0766379d
JS
229 exit(1);
230 }
231 if (chdir("/")) {
a7aaec14 232 error_report("not able to chdir to /: %s", strerror(errno));
0766379d
JS
233 exit(1);
234 }
235 }
236
237}
eb505be1
JS
238
239void os_daemonize(void)
240{
241 if (daemonize) {
63ce8e15 242 pid_t pid;
0be5e436 243 int fds[2];
eb505be1 244
63ce8e15
GA
245 if (pipe(fds) == -1) {
246 exit(1);
247 }
eb505be1 248
63ce8e15
GA
249 pid = fork();
250 if (pid > 0) {
251 uint8_t status;
252 ssize_t len;
eb505be1 253
63ce8e15 254 close(fds[1]);
eb505be1 255
ccea25f1
MT
256 do {
257 len = read(fds[0], &status, 1);
258 } while (len < 0 && errno == EINTR);
fee78fd6
MT
259
260 /* only exit successfully if our child actually wrote
261 * a one-byte zero to our pipe, upon successful init */
262 exit(len == 1 && status == 0 ? 0 : 1);
263
264 } else if (pid < 0) {
265 exit(1);
266 }
eb505be1 267
63ce8e15 268 close(fds[0]);
0be5e436
MT
269 daemon_pipe = fds[1];
270 qemu_set_cloexec(daemon_pipe);
eb505be1 271
63ce8e15 272 setsid();
eb505be1 273
63ce8e15
GA
274 pid = fork();
275 if (pid > 0) {
276 exit(0);
277 } else if (pid < 0) {
278 exit(1);
279 }
280 umask(027);
eb505be1
JS
281
282 signal(SIGTSTP, SIG_IGN);
283 signal(SIGTTOU, SIG_IGN);
284 signal(SIGTTIN, SIG_IGN);
285 }
286}
287
288void os_setup_post(void)
289{
290 int fd = 0;
291
292 if (daemonize) {
eb505be1 293 if (chdir("/")) {
a7aaec14 294 error_report("not able to chdir to /: %s", strerror(errno));
eb505be1
JS
295 exit(1);
296 }
63ce8e15
GA
297 TFR(fd = qemu_open("/dev/null", O_RDWR));
298 if (fd == -1) {
299 exit(1);
300 }
eb505be1
JS
301 }
302
e06eb601
JS
303 change_root();
304 change_process_uid();
eb505be1
JS
305
306 if (daemonize) {
25cec2b8
MT
307 uint8_t status = 0;
308 ssize_t len;
309
eb505be1
JS
310 dup2(fd, 0);
311 dup2(fd, 1);
96c33a45
DA
312 /* In case -D is given do not redirect stderr to /dev/null */
313 if (!qemu_logfile) {
314 dup2(fd, 2);
315 }
eb505be1
JS
316
317 close(fd);
25cec2b8
MT
318
319 do {
320 len = write(daemon_pipe, &status, 1);
321 } while (len < 0 && errno == EINTR);
322 if (len != 1) {
323 exit(1);
324 }
eb505be1
JS
325 }
326}
327
9156d763
JS
328void os_set_line_buffering(void)
329{
330 setvbuf(stdout, NULL, _IOLBF, 0);
331}
949d31e6 332
995ee2bf
HM
333bool is_daemonized(void)
334{
335 return daemonize;
336}
888a6bc6
SM
337
338int os_mlock(void)
339{
340 int ret = 0;
341
342 ret = mlockall(MCL_CURRENT | MCL_FUTURE);
343 if (ret < 0) {
a7aaec14 344 error_report("mlockall: %s", strerror(errno));
888a6bc6
SM
345 }
346
347 return ret;
348}