blob: c6ddb7d830198929d2805d74b64336fae12def08 [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 Sorensen69e8b162010-07-06 10:50:27 +020028/*needed for MAP_POPULATE before including qemu-options.h */
Jes Sorensen8847cfe2010-06-10 11:42:26 +020029#include <pwd.h>
Stefan Hajnoczicc4662f2011-07-09 10:22:07 +010030#include <grp.h>
Jes Sorensen61705402010-06-10 11:42:23 +020031#include <libgen.h>
Jes Sorensen86b645e2010-06-10 11:42:19 +020032
33/* Needed early for CONFIG_BSD etc. */
Paolo Bonzini9c17d612012-12-17 18:20:04 +010034#include "sysemu/sysemu.h"
Jes Sorensen59a52642010-06-10 11:42:25 +020035#include "net/slirp.h"
36#include "qemu-options.h"
Paolo Bonzinia59629f2015-03-31 13:01:05 +020037#include "qemu/rcu.h"
Thomas Huthf853ac62016-01-13 09:05:32 +010038#include "qemu/error-report.h"
Dimitris Aragiorgis96c33a42016-02-18 13:38:38 +020039#include "qemu/log.h"
Veronia Bahaaf348b6d2016-03-20 19:16:19 +020040#include "qemu/cutils.h"
Jes Sorensen86b645e2010-06-10 11:42:19 +020041
Jes Sorensence798cf2010-06-10 11:42:31 +020042#ifdef CONFIG_LINUX
43#include <sys/prctl.h>
Jes Sorensen949d31e2010-10-26 10:39:22 +020044#endif
45
Jes Sorensen8847cfe2010-06-10 11:42:26 +020046static struct passwd *user_pwd;
Jes Sorensen07663792010-06-10 11:42:27 +020047static const char *chroot_dir;
Jes Sorenseneb505be2010-06-10 11:42:28 +020048static int daemonize;
Michael Tokarev0be5e432014-10-30 17:30:51 +030049static int daemon_pipe;
Jes Sorensen8847cfe2010-06-10 11:42:26 +020050
Jes Sorensenfe98ac12010-06-10 11:42:21 +020051void os_setup_early_signal_handling(void)
Jes Sorensen86b645e2010-06-10 11:42:19 +020052{
53 struct sigaction act;
54 sigfillset(&act.sa_mask);
55 act.sa_flags = 0;
56 act.sa_handler = SIG_IGN;
57 sigaction(SIGPIPE, &act, NULL);
58}
Jes Sorensen8d963e62010-06-10 11:42:22 +020059
Gleb Natapovf64622c2011-03-15 13:56:04 +020060static void termsig_handler(int signal, siginfo_t *info, void *c)
Jes Sorensen8d963e62010-06-10 11:42:22 +020061{
Gleb Natapovf64622c2011-03-15 13:56:04 +020062 qemu_system_killed(info->si_signo, info->si_pid);
Jes Sorensen8d963e62010-06-10 11:42:22 +020063}
64
Jes Sorensen8d963e62010-06-10 11:42:22 +020065void os_setup_signal_handling(void)
66{
67 struct sigaction act;
68
69 memset(&act, 0, sizeof(act));
Gleb Natapovf64622c2011-03-15 13:56:04 +020070 act.sa_sigaction = termsig_handler;
71 act.sa_flags = SA_SIGINFO;
Jes Sorensen8d963e62010-06-10 11:42:22 +020072 sigaction(SIGINT, &act, NULL);
73 sigaction(SIGHUP, &act, NULL);
74 sigaction(SIGTERM, &act, NULL);
Jes Sorensen8d963e62010-06-10 11:42:22 +020075}
Jes Sorensen61705402010-06-10 11:42:23 +020076
77/* Find a likely location for support files using the location of the binary.
78 For installed binaries this will be "$bindir/../share/qemu". When
79 running from the build tree this will be "$bindir/../pc-bios". */
80#define SHARE_SUFFIX "/share/qemu"
81#define BUILD_SUFFIX "/pc-bios"
Fam Zheng10f5bff2014-02-10 14:48:51 +080082char *os_find_datadir(void)
Jes Sorensen61705402010-06-10 11:42:23 +020083{
Fam Zheng10f5bff2014-02-10 14:48:51 +080084 char *dir, *exec_dir;
Jes Sorensen61705402010-06-10 11:42:23 +020085 char *res;
Jes Sorensen61705402010-06-10 11:42:23 +020086 size_t max_len;
87
Fam Zheng10f5bff2014-02-10 14:48:51 +080088 exec_dir = qemu_get_exec_dir();
89 if (exec_dir == NULL) {
90 return NULL;
Jes Sorensen61705402010-06-10 11:42:23 +020091 }
Wei Jiangang55ad7812016-04-07 10:46:24 +080092 dir = g_path_get_dirname(exec_dir);
Jes Sorensen61705402010-06-10 11:42:23 +020093
94 max_len = strlen(dir) +
95 MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
Anthony Liguori7267c092011-08-20 22:09:37 -050096 res = g_malloc0(max_len);
Jes Sorensen61705402010-06-10 11:42:23 +020097 snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX);
98 if (access(res, R_OK)) {
99 snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX);
100 if (access(res, R_OK)) {
Anthony Liguori7267c092011-08-20 22:09:37 -0500101 g_free(res);
Jes Sorensen61705402010-06-10 11:42:23 +0200102 res = NULL;
103 }
104 }
105
Wei Jiangang55ad7812016-04-07 10:46:24 +0800106 g_free(dir);
Fam Zheng10f5bff2014-02-10 14:48:51 +0800107 g_free(exec_dir);
Jes Sorensen61705402010-06-10 11:42:23 +0200108 return res;
109}
110#undef SHARE_SUFFIX
111#undef BUILD_SUFFIX
Jes Sorensen59a52642010-06-10 11:42:25 +0200112
Jes Sorensence798cf2010-06-10 11:42:31 +0200113void os_set_proc_name(const char *s)
114{
115#if defined(PR_SET_NAME)
116 char name[16];
117 if (!s)
118 return;
Jim Meyering3eadc682012-10-04 13:09:51 +0200119 pstrcpy(name, sizeof(name), s);
Jes Sorensence798cf2010-06-10 11:42:31 +0200120 /* Could rewrite argv[0] too, but that's a bit more complicated.
121 This simple way is enough for `top'. */
122 if (prctl(PR_SET_NAME, name)) {
123 perror("unable to change process name");
124 exit(1);
125 }
126#else
127 fprintf(stderr, "Change of process name not supported by your OS\n");
128 exit(1);
129#endif
130}
131
Jes Sorensen59a52642010-06-10 11:42:25 +0200132/*
133 * Parse OS specific command line options.
134 * return 0 if option handled, -1 otherwise
135 */
136void os_parse_cmd_args(int index, const char *optarg)
137{
138 switch (index) {
139#ifdef CONFIG_SLIRP
140 case QEMU_OPTION_smb:
Thomas Huthf853ac62016-01-13 09:05:32 +0100141 error_report("The -smb option is deprecated. "
142 "Please use '-netdev user,smb=...' instead.");
Jes Sorensen59a52642010-06-10 11:42:25 +0200143 if (net_slirp_smb(optarg) < 0)
144 exit(1);
145 break;
146#endif
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200147 case QEMU_OPTION_runas:
148 user_pwd = getpwnam(optarg);
149 if (!user_pwd) {
150 fprintf(stderr, "User \"%s\" doesn't exist\n", optarg);
151 exit(1);
152 }
153 break;
Jes Sorensen07663792010-06-10 11:42:27 +0200154 case QEMU_OPTION_chroot:
155 chroot_dir = optarg;
156 break;
Jes Sorenseneb505be2010-06-10 11:42:28 +0200157 case QEMU_OPTION_daemonize:
158 daemonize = 1;
159 break;
Anthony Liguori70678b82012-08-03 18:28:37 -0500160#if defined(CONFIG_LINUX)
161 case QEMU_OPTION_enablefips:
162 fips_set_state(true);
163 break;
164#endif
Jes Sorensen59a52642010-06-10 11:42:25 +0200165 }
Jes Sorensen59a52642010-06-10 11:42:25 +0200166}
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200167
Jes Sorensene06eb602010-06-10 11:42:29 +0200168static void change_process_uid(void)
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200169{
170 if (user_pwd) {
171 if (setgid(user_pwd->pw_gid) < 0) {
172 fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
173 exit(1);
174 }
Stefan Hajnoczicc4662f2011-07-09 10:22:07 +0100175 if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
176 fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n",
177 user_pwd->pw_name, user_pwd->pw_gid);
178 exit(1);
179 }
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200180 if (setuid(user_pwd->pw_uid) < 0) {
181 fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
182 exit(1);
183 }
184 if (setuid(0) != -1) {
185 fprintf(stderr, "Dropping privileges failed\n");
186 exit(1);
187 }
188 }
189}
Jes Sorensen07663792010-06-10 11:42:27 +0200190
Jes Sorensene06eb602010-06-10 11:42:29 +0200191static void change_root(void)
Jes Sorensen07663792010-06-10 11:42:27 +0200192{
193 if (chroot_dir) {
194 if (chroot(chroot_dir) < 0) {
195 fprintf(stderr, "chroot failed\n");
196 exit(1);
197 }
198 if (chdir("/")) {
199 perror("not able to chdir to /");
200 exit(1);
201 }
202 }
203
204}
Jes Sorenseneb505be2010-06-10 11:42:28 +0200205
206void os_daemonize(void)
207{
208 if (daemonize) {
Gonglei63ce8e12014-09-26 16:14:30 +0800209 pid_t pid;
Michael Tokarev0be5e432014-10-30 17:30:51 +0300210 int fds[2];
Jes Sorenseneb505be2010-06-10 11:42:28 +0200211
Gonglei63ce8e12014-09-26 16:14:30 +0800212 if (pipe(fds) == -1) {
213 exit(1);
214 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200215
Gonglei63ce8e12014-09-26 16:14:30 +0800216 pid = fork();
217 if (pid > 0) {
218 uint8_t status;
219 ssize_t len;
Jes Sorenseneb505be2010-06-10 11:42:28 +0200220
Gonglei63ce8e12014-09-26 16:14:30 +0800221 close(fds[1]);
Jes Sorenseneb505be2010-06-10 11:42:28 +0200222
Michael Tokarevccea25f2014-10-30 17:37:16 +0300223 do {
224 len = read(fds[0], &status, 1);
225 } while (len < 0 && errno == EINTR);
Michael Tokarevfee78fd2014-10-30 17:40:48 +0300226
227 /* only exit successfully if our child actually wrote
228 * a one-byte zero to our pipe, upon successful init */
229 exit(len == 1 && status == 0 ? 0 : 1);
230
231 } else if (pid < 0) {
232 exit(1);
233 }
Gonglei63ce8e12014-09-26 16:14:30 +0800234
235 close(fds[0]);
Michael Tokarev0be5e432014-10-30 17:30:51 +0300236 daemon_pipe = fds[1];
237 qemu_set_cloexec(daemon_pipe);
Gonglei63ce8e12014-09-26 16:14:30 +0800238
239 setsid();
240
241 pid = fork();
242 if (pid > 0) {
243 exit(0);
244 } else if (pid < 0) {
Jes Sorenseneb505be2010-06-10 11:42:28 +0200245 exit(1);
Gonglei63ce8e12014-09-26 16:14:30 +0800246 }
247 umask(027);
Jes Sorenseneb505be2010-06-10 11:42:28 +0200248
249 signal(SIGTSTP, SIG_IGN);
250 signal(SIGTTOU, SIG_IGN);
251 signal(SIGTTIN, SIG_IGN);
Paolo Bonzinia59629f2015-03-31 13:01:05 +0200252 rcu_after_fork();
Jes Sorenseneb505be2010-06-10 11:42:28 +0200253 }
254}
255
256void os_setup_post(void)
257{
258 int fd = 0;
259
260 if (daemonize) {
Jes Sorenseneb505be2010-06-10 11:42:28 +0200261 if (chdir("/")) {
262 perror("not able to chdir to /");
263 exit(1);
264 }
Gonglei63ce8e12014-09-26 16:14:30 +0800265 TFR(fd = qemu_open("/dev/null", O_RDWR));
266 if (fd == -1) {
267 exit(1);
268 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200269 }
270
Jes Sorensene06eb602010-06-10 11:42:29 +0200271 change_root();
272 change_process_uid();
Jes Sorenseneb505be2010-06-10 11:42:28 +0200273
274 if (daemonize) {
Michael Tokarev25cec2b2014-10-30 17:47:46 +0300275 uint8_t status = 0;
276 ssize_t len;
277
Jes Sorenseneb505be2010-06-10 11:42:28 +0200278 dup2(fd, 0);
279 dup2(fd, 1);
Dimitris Aragiorgis96c33a42016-02-18 13:38:38 +0200280 /* In case -D is given do not redirect stderr to /dev/null */
281 if (!qemu_logfile) {
282 dup2(fd, 2);
283 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200284
285 close(fd);
Michael Tokarev25cec2b2014-10-30 17:47:46 +0300286
287 do {
288 len = write(daemon_pipe, &status, 1);
289 } while (len < 0 && errno == EINTR);
290 if (len != 1) {
291 exit(1);
292 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200293 }
294}
295
Jes Sorensen9156d762010-06-10 11:42:30 +0200296void os_set_line_buffering(void)
297{
298 setvbuf(stdout, NULL, _IOLBF, 0);
299}
Jes Sorensen949d31e2010-10-26 10:39:22 +0200300
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200301int qemu_create_pidfile(const char *filename)
302{
303 char buffer[128];
304 int len;
305 int fd;
306
307 fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
308 if (fd == -1) {
309 return -1;
310 }
311 if (lockf(fd, F_TLOCK, 0) == -1) {
Markus Armbruster1bbd1592011-11-11 10:40:09 +0100312 close(fd);
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200313 return -1;
314 }
Andreas Färber953ffe02011-06-02 19:58:06 +0200315 len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200316 if (write(fd, buffer, len) != len) {
Markus Armbruster1bbd1592011-11-11 10:40:09 +0100317 close(fd);
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200318 return -1;
319 }
320
Laszlo Ersek93dd7482012-01-27 14:34:05 +0100321 /* keep pidfile open & locked forever */
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200322 return 0;
323}
Hitoshi Mitake995ee2b2012-09-15 01:15:41 +0900324
325bool is_daemonized(void)
326{
327 return daemonize;
328}
Satoru Moriya888a6bc2013-04-19 16:42:06 +0200329
330int os_mlock(void)
331{
332 int ret = 0;
333
334 ret = mlockall(MCL_CURRENT | MCL_FUTURE);
335 if (ret < 0) {
336 perror("mlockall");
337 }
338
339 return ret;
340}