blob: e4da406f38ca0c63a43db09d2ee8ccb017e1b7ec [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
26#include <unistd.h>
27#include <fcntl.h>
28#include <signal.h>
Jes Sorensen8d963e62010-06-10 11:42:22 +020029#include <sys/types.h>
30#include <sys/wait.h>
Jes Sorensen69e8b162010-07-06 10:50:27 +020031/*needed for MAP_POPULATE before including qemu-options.h */
32#include <sys/mman.h>
Jes Sorensen8847cfe2010-06-10 11:42:26 +020033#include <pwd.h>
Stefan Hajnoczicc4662f2011-07-09 10:22:07 +010034#include <grp.h>
Jes Sorensen61705402010-06-10 11:42:23 +020035#include <libgen.h>
Jes Sorensen86b645e2010-06-10 11:42:19 +020036
37/* Needed early for CONFIG_BSD etc. */
38#include "config-host.h"
Paolo Bonzini9c17d612012-12-17 18:20:04 +010039#include "sysemu/sysemu.h"
Jes Sorensen59a52642010-06-10 11:42:25 +020040#include "net/slirp.h"
41#include "qemu-options.h"
Paolo Bonzinia59629f2015-03-31 13:01:05 +020042#include "qemu/rcu.h"
Jes Sorensen86b645e2010-06-10 11:42:19 +020043
Jes Sorensence798cf2010-06-10 11:42:31 +020044#ifdef CONFIG_LINUX
45#include <sys/prctl.h>
Jes Sorensen949d31e2010-10-26 10:39:22 +020046#endif
47
Jes Sorensen8847cfe2010-06-10 11:42:26 +020048static struct passwd *user_pwd;
Jes Sorensen07663792010-06-10 11:42:27 +020049static const char *chroot_dir;
Jes Sorenseneb505be2010-06-10 11:42:28 +020050static int daemonize;
Michael Tokarev0be5e432014-10-30 17:30:51 +030051static int daemon_pipe;
Jes Sorensen8847cfe2010-06-10 11:42:26 +020052
Jes Sorensenfe98ac12010-06-10 11:42:21 +020053void os_setup_early_signal_handling(void)
Jes Sorensen86b645e2010-06-10 11:42:19 +020054{
55 struct sigaction act;
56 sigfillset(&act.sa_mask);
57 act.sa_flags = 0;
58 act.sa_handler = SIG_IGN;
59 sigaction(SIGPIPE, &act, NULL);
60}
Jes Sorensen8d963e62010-06-10 11:42:22 +020061
Gleb Natapovf64622c2011-03-15 13:56:04 +020062static void termsig_handler(int signal, siginfo_t *info, void *c)
Jes Sorensen8d963e62010-06-10 11:42:22 +020063{
Gleb Natapovf64622c2011-03-15 13:56:04 +020064 qemu_system_killed(info->si_signo, info->si_pid);
Jes Sorensen8d963e62010-06-10 11:42:22 +020065}
66
Jes Sorensen8d963e62010-06-10 11:42:22 +020067void os_setup_signal_handling(void)
68{
69 struct sigaction act;
70
71 memset(&act, 0, sizeof(act));
Gleb Natapovf64622c2011-03-15 13:56:04 +020072 act.sa_sigaction = termsig_handler;
73 act.sa_flags = SA_SIGINFO;
Jes Sorensen8d963e62010-06-10 11:42:22 +020074 sigaction(SIGINT, &act, NULL);
75 sigaction(SIGHUP, &act, NULL);
76 sigaction(SIGTERM, &act, NULL);
Jes Sorensen8d963e62010-06-10 11:42:22 +020077}
Jes Sorensen61705402010-06-10 11:42:23 +020078
79/* Find a likely location for support files using the location of the binary.
80 For installed binaries this will be "$bindir/../share/qemu". When
81 running from the build tree this will be "$bindir/../pc-bios". */
82#define SHARE_SUFFIX "/share/qemu"
83#define BUILD_SUFFIX "/pc-bios"
Fam Zheng10f5bff2014-02-10 14:48:51 +080084char *os_find_datadir(void)
Jes Sorensen61705402010-06-10 11:42:23 +020085{
Fam Zheng10f5bff2014-02-10 14:48:51 +080086 char *dir, *exec_dir;
Jes Sorensen61705402010-06-10 11:42:23 +020087 char *res;
Jes Sorensen61705402010-06-10 11:42:23 +020088 size_t max_len;
89
Fam Zheng10f5bff2014-02-10 14:48:51 +080090 exec_dir = qemu_get_exec_dir();
91 if (exec_dir == NULL) {
92 return NULL;
Jes Sorensen61705402010-06-10 11:42:23 +020093 }
Fam Zheng10f5bff2014-02-10 14:48:51 +080094 dir = dirname(exec_dir);
Jes Sorensen61705402010-06-10 11:42:23 +020095
96 max_len = strlen(dir) +
97 MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
Anthony Liguori7267c092011-08-20 22:09:37 -050098 res = g_malloc0(max_len);
Jes Sorensen61705402010-06-10 11:42:23 +020099 snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX);
100 if (access(res, R_OK)) {
101 snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX);
102 if (access(res, R_OK)) {
Anthony Liguori7267c092011-08-20 22:09:37 -0500103 g_free(res);
Jes Sorensen61705402010-06-10 11:42:23 +0200104 res = NULL;
105 }
106 }
107
Fam Zheng10f5bff2014-02-10 14:48:51 +0800108 g_free(exec_dir);
Jes Sorensen61705402010-06-10 11:42:23 +0200109 return res;
110}
111#undef SHARE_SUFFIX
112#undef BUILD_SUFFIX
Jes Sorensen59a52642010-06-10 11:42:25 +0200113
Jes Sorensence798cf2010-06-10 11:42:31 +0200114void os_set_proc_name(const char *s)
115{
116#if defined(PR_SET_NAME)
117 char name[16];
118 if (!s)
119 return;
Jim Meyering3eadc682012-10-04 13:09:51 +0200120 pstrcpy(name, sizeof(name), s);
Jes Sorensence798cf2010-06-10 11:42:31 +0200121 /* Could rewrite argv[0] too, but that's a bit more complicated.
122 This simple way is enough for `top'. */
123 if (prctl(PR_SET_NAME, name)) {
124 perror("unable to change process name");
125 exit(1);
126 }
127#else
128 fprintf(stderr, "Change of process name not supported by your OS\n");
129 exit(1);
130#endif
131}
132
Jes Sorensen59a52642010-06-10 11:42:25 +0200133/*
134 * Parse OS specific command line options.
135 * return 0 if option handled, -1 otherwise
136 */
137void os_parse_cmd_args(int index, const char *optarg)
138{
139 switch (index) {
140#ifdef CONFIG_SLIRP
141 case QEMU_OPTION_smb:
142 if (net_slirp_smb(optarg) < 0)
143 exit(1);
144 break;
145#endif
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200146 case QEMU_OPTION_runas:
147 user_pwd = getpwnam(optarg);
148 if (!user_pwd) {
149 fprintf(stderr, "User \"%s\" doesn't exist\n", optarg);
150 exit(1);
151 }
152 break;
Jes Sorensen07663792010-06-10 11:42:27 +0200153 case QEMU_OPTION_chroot:
154 chroot_dir = optarg;
155 break;
Jes Sorenseneb505be2010-06-10 11:42:28 +0200156 case QEMU_OPTION_daemonize:
157 daemonize = 1;
158 break;
Anthony Liguori70678b82012-08-03 18:28:37 -0500159#if defined(CONFIG_LINUX)
160 case QEMU_OPTION_enablefips:
161 fips_set_state(true);
162 break;
163#endif
Jes Sorensen59a52642010-06-10 11:42:25 +0200164 }
Jes Sorensen59a52642010-06-10 11:42:25 +0200165}
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200166
Jes Sorensene06eb602010-06-10 11:42:29 +0200167static void change_process_uid(void)
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200168{
169 if (user_pwd) {
170 if (setgid(user_pwd->pw_gid) < 0) {
171 fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
172 exit(1);
173 }
Stefan Hajnoczicc4662f2011-07-09 10:22:07 +0100174 if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
175 fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n",
176 user_pwd->pw_name, user_pwd->pw_gid);
177 exit(1);
178 }
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200179 if (setuid(user_pwd->pw_uid) < 0) {
180 fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
181 exit(1);
182 }
183 if (setuid(0) != -1) {
184 fprintf(stderr, "Dropping privileges failed\n");
185 exit(1);
186 }
187 }
188}
Jes Sorensen07663792010-06-10 11:42:27 +0200189
Jes Sorensene06eb602010-06-10 11:42:29 +0200190static void change_root(void)
Jes Sorensen07663792010-06-10 11:42:27 +0200191{
192 if (chroot_dir) {
193 if (chroot(chroot_dir) < 0) {
194 fprintf(stderr, "chroot failed\n");
195 exit(1);
196 }
197 if (chdir("/")) {
198 perror("not able to chdir to /");
199 exit(1);
200 }
201 }
202
203}
Jes Sorenseneb505be2010-06-10 11:42:28 +0200204
205void os_daemonize(void)
206{
207 if (daemonize) {
Gonglei63ce8e12014-09-26 16:14:30 +0800208 pid_t pid;
Michael Tokarev0be5e432014-10-30 17:30:51 +0300209 int fds[2];
Jes Sorenseneb505be2010-06-10 11:42:28 +0200210
Gonglei63ce8e12014-09-26 16:14:30 +0800211 if (pipe(fds) == -1) {
212 exit(1);
213 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200214
Gonglei63ce8e12014-09-26 16:14:30 +0800215 pid = fork();
216 if (pid > 0) {
217 uint8_t status;
218 ssize_t len;
Jes Sorenseneb505be2010-06-10 11:42:28 +0200219
Gonglei63ce8e12014-09-26 16:14:30 +0800220 close(fds[1]);
Jes Sorenseneb505be2010-06-10 11:42:28 +0200221
Michael Tokarevccea25f2014-10-30 17:37:16 +0300222 do {
223 len = read(fds[0], &status, 1);
224 } while (len < 0 && errno == EINTR);
Michael Tokarevfee78fd2014-10-30 17:40:48 +0300225
226 /* only exit successfully if our child actually wrote
227 * a one-byte zero to our pipe, upon successful init */
228 exit(len == 1 && status == 0 ? 0 : 1);
229
230 } else if (pid < 0) {
231 exit(1);
232 }
Gonglei63ce8e12014-09-26 16:14:30 +0800233
234 close(fds[0]);
Michael Tokarev0be5e432014-10-30 17:30:51 +0300235 daemon_pipe = fds[1];
236 qemu_set_cloexec(daemon_pipe);
Gonglei63ce8e12014-09-26 16:14:30 +0800237
238 setsid();
239
240 pid = fork();
241 if (pid > 0) {
242 exit(0);
243 } else if (pid < 0) {
Jes Sorenseneb505be2010-06-10 11:42:28 +0200244 exit(1);
Gonglei63ce8e12014-09-26 16:14:30 +0800245 }
246 umask(027);
Jes Sorenseneb505be2010-06-10 11:42:28 +0200247
248 signal(SIGTSTP, SIG_IGN);
249 signal(SIGTTOU, SIG_IGN);
250 signal(SIGTTIN, SIG_IGN);
Paolo Bonzinia59629f2015-03-31 13:01:05 +0200251 rcu_after_fork();
Jes Sorenseneb505be2010-06-10 11:42:28 +0200252 }
253}
254
255void os_setup_post(void)
256{
257 int fd = 0;
258
259 if (daemonize) {
Jes Sorenseneb505be2010-06-10 11:42:28 +0200260 if (chdir("/")) {
261 perror("not able to chdir to /");
262 exit(1);
263 }
Gonglei63ce8e12014-09-26 16:14:30 +0800264 TFR(fd = qemu_open("/dev/null", O_RDWR));
265 if (fd == -1) {
266 exit(1);
267 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200268 }
269
Jes Sorensene06eb602010-06-10 11:42:29 +0200270 change_root();
271 change_process_uid();
Jes Sorenseneb505be2010-06-10 11:42:28 +0200272
273 if (daemonize) {
Michael Tokarev25cec2b2014-10-30 17:47:46 +0300274 uint8_t status = 0;
275 ssize_t len;
276
Jes Sorenseneb505be2010-06-10 11:42:28 +0200277 dup2(fd, 0);
278 dup2(fd, 1);
279 dup2(fd, 2);
280
281 close(fd);
Michael Tokarev25cec2b2014-10-30 17:47:46 +0300282
283 do {
284 len = write(daemon_pipe, &status, 1);
285 } while (len < 0 && errno == EINTR);
286 if (len != 1) {
287 exit(1);
288 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200289 }
290}
291
Jes Sorensen9156d762010-06-10 11:42:30 +0200292void os_set_line_buffering(void)
293{
294 setvbuf(stdout, NULL, _IOLBF, 0);
295}
Jes Sorensen949d31e2010-10-26 10:39:22 +0200296
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200297int qemu_create_pidfile(const char *filename)
298{
299 char buffer[128];
300 int len;
301 int fd;
302
303 fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
304 if (fd == -1) {
305 return -1;
306 }
307 if (lockf(fd, F_TLOCK, 0) == -1) {
Markus Armbruster1bbd1592011-11-11 10:40:09 +0100308 close(fd);
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200309 return -1;
310 }
Andreas Färber953ffe02011-06-02 19:58:06 +0200311 len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200312 if (write(fd, buffer, len) != len) {
Markus Armbruster1bbd1592011-11-11 10:40:09 +0100313 close(fd);
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200314 return -1;
315 }
316
Laszlo Ersek93dd7482012-01-27 14:34:05 +0100317 /* keep pidfile open & locked forever */
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200318 return 0;
319}
Hitoshi Mitake995ee2b2012-09-15 01:15:41 +0900320
321bool is_daemonized(void)
322{
323 return daemonize;
324}
Satoru Moriya888a6bc2013-04-19 16:42:06 +0200325
326int os_mlock(void)
327{
328 int ret = 0;
329
330 ret = mlockall(MCL_CURRENT | MCL_FUTURE);
331 if (ret < 0) {
332 perror("mlockall");
333 }
334
335 return ret;
336}