blob: 9ce6f74513020cea1fe6996d5f130767c7103c5d [file] [log] [blame]
Jes Sorensen86b645e2010-06-10 11:42:19 +02001/*
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
Peter Maydelld38ea872016-01-29 17:50:05 +000026#include "qemu/osdep.h"
Jes Sorensen8d963e62010-06-10 11:42:22 +020027#include <sys/wait.h>
Jes Sorensen8847cfe2010-06-10 11:42:26 +020028#include <pwd.h>
Stefan Hajnoczicc4662f2011-07-09 10:22:07 +010029#include <grp.h>
Jes Sorensen61705402010-06-10 11:42:23 +020030#include <libgen.h>
Jes Sorensen86b645e2010-06-10 11:42:19 +020031
32/* Needed early for CONFIG_BSD etc. */
Paolo Bonzini9c17d612012-12-17 18:20:04 +010033#include "sysemu/sysemu.h"
Jes Sorensen59a52642010-06-10 11:42:25 +020034#include "net/slirp.h"
35#include "qemu-options.h"
Thomas Huthf853ac62016-01-13 09:05:32 +010036#include "qemu/error-report.h"
Dimitris Aragiorgis96c33a42016-02-18 13:38:38 +020037#include "qemu/log.h"
Veronia Bahaaf348b6d2016-03-20 19:16:19 +020038#include "qemu/cutils.h"
Jes Sorensen86b645e2010-06-10 11:42:19 +020039
Jes Sorensence798cf2010-06-10 11:42:31 +020040#ifdef CONFIG_LINUX
41#include <sys/prctl.h>
Jes Sorensen949d31e2010-10-26 10:39:22 +020042#endif
43
Ian Jackson2c42f1e2017-09-15 18:10:44 +010044/*
45 * Must set all three of these at once.
46 * Legal combinations are unset by name by uid
47 */
48static struct passwd *user_pwd; /* NULL non-NULL NULL */
49static uid_t user_uid = (uid_t)-1; /* -1 -1 >=0 */
50static gid_t user_gid = (gid_t)-1; /* -1 -1 >=0 */
51
Jes Sorensen07663792010-06-10 11:42:27 +020052static const char *chroot_dir;
Jes Sorenseneb505be2010-06-10 11:42:28 +020053static int daemonize;
Michael Tokarev0be5e432014-10-30 17:30:51 +030054static int daemon_pipe;
Jes Sorensen8847cfe2010-06-10 11:42:26 +020055
Jes Sorensenfe98ac12010-06-10 11:42:21 +020056void os_setup_early_signal_handling(void)
Jes Sorensen86b645e2010-06-10 11:42:19 +020057{
58 struct sigaction act;
59 sigfillset(&act.sa_mask);
60 act.sa_flags = 0;
61 act.sa_handler = SIG_IGN;
62 sigaction(SIGPIPE, &act, NULL);
63}
Jes Sorensen8d963e62010-06-10 11:42:22 +020064
Gleb Natapovf64622c2011-03-15 13:56:04 +020065static void termsig_handler(int signal, siginfo_t *info, void *c)
Jes Sorensen8d963e62010-06-10 11:42:22 +020066{
Gleb Natapovf64622c2011-03-15 13:56:04 +020067 qemu_system_killed(info->si_signo, info->si_pid);
Jes Sorensen8d963e62010-06-10 11:42:22 +020068}
69
Jes Sorensen8d963e62010-06-10 11:42:22 +020070void os_setup_signal_handling(void)
71{
72 struct sigaction act;
73
74 memset(&act, 0, sizeof(act));
Gleb Natapovf64622c2011-03-15 13:56:04 +020075 act.sa_sigaction = termsig_handler;
76 act.sa_flags = SA_SIGINFO;
Jes Sorensen8d963e62010-06-10 11:42:22 +020077 sigaction(SIGINT, &act, NULL);
78 sigaction(SIGHUP, &act, NULL);
79 sigaction(SIGTERM, &act, NULL);
Jes Sorensen8d963e62010-06-10 11:42:22 +020080}
Jes Sorensen61705402010-06-10 11:42:23 +020081
82/* Find a likely location for support files using the location of the binary.
83 For installed binaries this will be "$bindir/../share/qemu". When
84 running from the build tree this will be "$bindir/../pc-bios". */
85#define SHARE_SUFFIX "/share/qemu"
86#define BUILD_SUFFIX "/pc-bios"
Fam Zheng10f5bff2014-02-10 14:48:51 +080087char *os_find_datadir(void)
Jes Sorensen61705402010-06-10 11:42:23 +020088{
Fam Zheng10f5bff2014-02-10 14:48:51 +080089 char *dir, *exec_dir;
Jes Sorensen61705402010-06-10 11:42:23 +020090 char *res;
Jes Sorensen61705402010-06-10 11:42:23 +020091 size_t max_len;
92
Fam Zheng10f5bff2014-02-10 14:48:51 +080093 exec_dir = qemu_get_exec_dir();
94 if (exec_dir == NULL) {
95 return NULL;
Jes Sorensen61705402010-06-10 11:42:23 +020096 }
Wei Jiangang55ad7812016-04-07 10:46:24 +080097 dir = g_path_get_dirname(exec_dir);
Jes Sorensen61705402010-06-10 11:42:23 +020098
99 max_len = strlen(dir) +
100 MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
Anthony Liguori7267c092011-08-20 22:09:37 -0500101 res = g_malloc0(max_len);
Jes Sorensen61705402010-06-10 11:42:23 +0200102 snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX);
103 if (access(res, R_OK)) {
104 snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX);
105 if (access(res, R_OK)) {
Anthony Liguori7267c092011-08-20 22:09:37 -0500106 g_free(res);
Jes Sorensen61705402010-06-10 11:42:23 +0200107 res = NULL;
108 }
109 }
110
Wei Jiangang55ad7812016-04-07 10:46:24 +0800111 g_free(dir);
Fam Zheng10f5bff2014-02-10 14:48:51 +0800112 g_free(exec_dir);
Jes Sorensen61705402010-06-10 11:42:23 +0200113 return res;
114}
115#undef SHARE_SUFFIX
116#undef BUILD_SUFFIX
Jes Sorensen59a52642010-06-10 11:42:25 +0200117
Jes Sorensence798cf2010-06-10 11:42:31 +0200118void os_set_proc_name(const char *s)
119{
120#if defined(PR_SET_NAME)
121 char name[16];
122 if (!s)
123 return;
Jim Meyering3eadc682012-10-04 13:09:51 +0200124 pstrcpy(name, sizeof(name), s);
Jes Sorensence798cf2010-06-10 11:42:31 +0200125 /* Could rewrite argv[0] too, but that's a bit more complicated.
126 This simple way is enough for `top'. */
127 if (prctl(PR_SET_NAME, name)) {
Ian Jacksona7aaec12018-04-16 15:16:23 +0100128 error_report("unable to change process name: %s", strerror(errno));
Jes Sorensence798cf2010-06-10 11:42:31 +0200129 exit(1);
130 }
131#else
Ian Jackson22cd4f42018-04-16 15:15:51 +0100132 error_report("Change of process name not supported by your OS");
Jes Sorensence798cf2010-06-10 11:42:31 +0200133 exit(1);
134#endif
135}
136
Ian Jackson2c42f1e2017-09-15 18:10:44 +0100137
138static bool os_parse_runas_uid_gid(const char *optarg)
139{
140 unsigned long lv;
141 const char *ep;
142 uid_t got_uid;
143 gid_t got_gid;
144 int rc;
145
146 rc = qemu_strtoul(optarg, &ep, 0, &lv);
147 got_uid = lv; /* overflow here is ID in C99 */
148 if (rc || *ep != ':' || got_uid != lv || got_uid == (uid_t)-1) {
149 return false;
150 }
151
152 rc = qemu_strtoul(ep + 1, 0, 0, &lv);
153 got_gid = lv; /* overflow here is ID in C99 */
154 if (rc || got_gid != lv || got_gid == (gid_t)-1) {
155 return false;
156 }
157
158 user_pwd = NULL;
159 user_uid = got_uid;
160 user_gid = got_gid;
161 return true;
162}
163
Jes Sorensen59a52642010-06-10 11:42:25 +0200164/*
165 * Parse OS specific command line options.
166 * return 0 if option handled, -1 otherwise
167 */
Thomas Huth1217d6ca2018-05-04 19:01:07 +0200168int os_parse_cmd_args(int index, const char *optarg)
Jes Sorensen59a52642010-06-10 11:42:25 +0200169{
170 switch (index) {
171#ifdef CONFIG_SLIRP
172 case QEMU_OPTION_smb:
Thomas Huthf853ac62016-01-13 09:05:32 +0100173 error_report("The -smb option is deprecated. "
174 "Please use '-netdev user,smb=...' instead.");
Jes Sorensen59a52642010-06-10 11:42:25 +0200175 if (net_slirp_smb(optarg) < 0)
176 exit(1);
177 break;
178#endif
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200179 case QEMU_OPTION_runas:
180 user_pwd = getpwnam(optarg);
Ian Jackson2c42f1e2017-09-15 18:10:44 +0100181 if (user_pwd) {
182 user_uid = -1;
183 user_gid = -1;
184 } else if (!os_parse_runas_uid_gid(optarg)) {
185 error_report("User \"%s\" doesn't exist"
186 " (and is not <uid>:<gid>)",
187 optarg);
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200188 exit(1);
189 }
190 break;
Jes Sorensen07663792010-06-10 11:42:27 +0200191 case QEMU_OPTION_chroot:
192 chroot_dir = optarg;
193 break;
Jes Sorenseneb505be2010-06-10 11:42:28 +0200194 case QEMU_OPTION_daemonize:
195 daemonize = 1;
196 break;
Anthony Liguori70678b82012-08-03 18:28:37 -0500197#if defined(CONFIG_LINUX)
198 case QEMU_OPTION_enablefips:
199 fips_set_state(true);
200 break;
201#endif
Thomas Huth1217d6ca2018-05-04 19:01:07 +0200202 default:
203 return -1;
Jes Sorensen59a52642010-06-10 11:42:25 +0200204 }
Thomas Huth1217d6ca2018-05-04 19:01:07 +0200205
206 return 0;
Jes Sorensen59a52642010-06-10 11:42:25 +0200207}
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200208
Jes Sorensene06eb602010-06-10 11:42:29 +0200209static void change_process_uid(void)
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200210{
Ian Jackson2c42f1e2017-09-15 18:10:44 +0100211 assert((user_uid == (uid_t)-1) || user_pwd == NULL);
212 assert((user_uid == (uid_t)-1) ==
213 (user_gid == (gid_t)-1));
214
215 if (user_pwd || user_uid != (uid_t)-1) {
216 gid_t intended_gid = user_pwd ? user_pwd->pw_gid : user_gid;
217 uid_t intended_uid = user_pwd ? user_pwd->pw_uid : user_uid;
218 if (setgid(intended_gid) < 0) {
219 error_report("Failed to setgid(%d)", intended_gid);
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200220 exit(1);
221 }
Ian Jackson2c42f1e2017-09-15 18:10:44 +0100222 if (user_pwd) {
223 if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
224 error_report("Failed to initgroups(\"%s\", %d)",
225 user_pwd->pw_name, user_pwd->pw_gid);
226 exit(1);
227 }
228 } else {
229 if (setgroups(1, &user_gid) < 0) {
230 error_report("Failed to setgroups(1, [%d])",
231 user_gid);
232 exit(1);
233 }
Stefan Hajnoczicc4662f2011-07-09 10:22:07 +0100234 }
Ian Jackson2c42f1e2017-09-15 18:10:44 +0100235 if (setuid(intended_uid) < 0) {
236 error_report("Failed to setuid(%d)", intended_uid);
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200237 exit(1);
238 }
239 if (setuid(0) != -1) {
Ian Jacksonf0a21712018-04-16 15:08:03 +0100240 error_report("Dropping privileges failed");
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200241 exit(1);
242 }
243 }
244}
Jes Sorensen07663792010-06-10 11:42:27 +0200245
Jes Sorensene06eb602010-06-10 11:42:29 +0200246static void change_root(void)
Jes Sorensen07663792010-06-10 11:42:27 +0200247{
248 if (chroot_dir) {
249 if (chroot(chroot_dir) < 0) {
Ian Jackson22cd4f42018-04-16 15:15:51 +0100250 error_report("chroot failed");
Jes Sorensen07663792010-06-10 11:42:27 +0200251 exit(1);
252 }
253 if (chdir("/")) {
Ian Jacksona7aaec12018-04-16 15:16:23 +0100254 error_report("not able to chdir to /: %s", strerror(errno));
Jes Sorensen07663792010-06-10 11:42:27 +0200255 exit(1);
256 }
257 }
258
259}
Jes Sorenseneb505be2010-06-10 11:42:28 +0200260
261void os_daemonize(void)
262{
263 if (daemonize) {
Gonglei63ce8e12014-09-26 16:14:30 +0800264 pid_t pid;
Michael Tokarev0be5e432014-10-30 17:30:51 +0300265 int fds[2];
Jes Sorenseneb505be2010-06-10 11:42:28 +0200266
Gonglei63ce8e12014-09-26 16:14:30 +0800267 if (pipe(fds) == -1) {
268 exit(1);
269 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200270
Gonglei63ce8e12014-09-26 16:14:30 +0800271 pid = fork();
272 if (pid > 0) {
273 uint8_t status;
274 ssize_t len;
Jes Sorenseneb505be2010-06-10 11:42:28 +0200275
Gonglei63ce8e12014-09-26 16:14:30 +0800276 close(fds[1]);
Jes Sorenseneb505be2010-06-10 11:42:28 +0200277
Michael Tokarevccea25f2014-10-30 17:37:16 +0300278 do {
279 len = read(fds[0], &status, 1);
280 } while (len < 0 && errno == EINTR);
Michael Tokarevfee78fd2014-10-30 17:40:48 +0300281
282 /* only exit successfully if our child actually wrote
283 * a one-byte zero to our pipe, upon successful init */
284 exit(len == 1 && status == 0 ? 0 : 1);
285
286 } else if (pid < 0) {
287 exit(1);
288 }
Gonglei63ce8e12014-09-26 16:14:30 +0800289
290 close(fds[0]);
Michael Tokarev0be5e432014-10-30 17:30:51 +0300291 daemon_pipe = fds[1];
292 qemu_set_cloexec(daemon_pipe);
Gonglei63ce8e12014-09-26 16:14:30 +0800293
294 setsid();
295
296 pid = fork();
297 if (pid > 0) {
298 exit(0);
299 } else if (pid < 0) {
Jes Sorenseneb505be2010-06-10 11:42:28 +0200300 exit(1);
Gonglei63ce8e12014-09-26 16:14:30 +0800301 }
302 umask(027);
Jes Sorenseneb505be2010-06-10 11:42:28 +0200303
304 signal(SIGTSTP, SIG_IGN);
305 signal(SIGTTOU, SIG_IGN);
306 signal(SIGTTIN, SIG_IGN);
307 }
308}
309
310void os_setup_post(void)
311{
312 int fd = 0;
313
314 if (daemonize) {
Jes Sorenseneb505be2010-06-10 11:42:28 +0200315 if (chdir("/")) {
Ian Jacksona7aaec12018-04-16 15:16:23 +0100316 error_report("not able to chdir to /: %s", strerror(errno));
Jes Sorenseneb505be2010-06-10 11:42:28 +0200317 exit(1);
318 }
Gonglei63ce8e12014-09-26 16:14:30 +0800319 TFR(fd = qemu_open("/dev/null", O_RDWR));
320 if (fd == -1) {
321 exit(1);
322 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200323 }
324
Jes Sorensene06eb602010-06-10 11:42:29 +0200325 change_root();
326 change_process_uid();
Jes Sorenseneb505be2010-06-10 11:42:28 +0200327
328 if (daemonize) {
Michael Tokarev25cec2b2014-10-30 17:47:46 +0300329 uint8_t status = 0;
330 ssize_t len;
331
Jes Sorenseneb505be2010-06-10 11:42:28 +0200332 dup2(fd, 0);
333 dup2(fd, 1);
Dimitris Aragiorgis96c33a42016-02-18 13:38:38 +0200334 /* In case -D is given do not redirect stderr to /dev/null */
335 if (!qemu_logfile) {
336 dup2(fd, 2);
337 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200338
339 close(fd);
Michael Tokarev25cec2b2014-10-30 17:47:46 +0300340
341 do {
342 len = write(daemon_pipe, &status, 1);
343 } while (len < 0 && errno == EINTR);
344 if (len != 1) {
345 exit(1);
346 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200347 }
348}
349
Jes Sorensen9156d762010-06-10 11:42:30 +0200350void os_set_line_buffering(void)
351{
352 setvbuf(stdout, NULL, _IOLBF, 0);
353}
Jes Sorensen949d31e2010-10-26 10:39:22 +0200354
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200355int qemu_create_pidfile(const char *filename)
356{
357 char buffer[128];
358 int len;
359 int fd;
360
361 fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
362 if (fd == -1) {
363 return -1;
364 }
365 if (lockf(fd, F_TLOCK, 0) == -1) {
Markus Armbruster1bbd1592011-11-11 10:40:09 +0100366 close(fd);
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200367 return -1;
368 }
Andreas Färber953ffe02011-06-02 19:58:06 +0200369 len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200370 if (write(fd, buffer, len) != len) {
Markus Armbruster1bbd1592011-11-11 10:40:09 +0100371 close(fd);
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200372 return -1;
373 }
374
Laszlo Ersek93dd7482012-01-27 14:34:05 +0100375 /* keep pidfile open & locked forever */
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200376 return 0;
377}
Hitoshi Mitake995ee2b2012-09-15 01:15:41 +0900378
379bool is_daemonized(void)
380{
381 return daemonize;
382}
Satoru Moriya888a6bc2013-04-19 16:42:06 +0200383
384int os_mlock(void)
385{
386 int ret = 0;
387
388 ret = mlockall(MCL_CURRENT | MCL_FUTURE);
389 if (ret < 0) {
Ian Jacksona7aaec12018-04-16 15:16:23 +0100390 error_report("mlockall: %s", strerror(errno));
Satoru Moriya888a6bc2013-04-19 16:42:06 +0200391 }
392
393 return ret;
394}