blob: ba091f1530bfaf6d3a59b720bdb6412058f17b67 [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"
Jes Sorensen86b645e2010-06-10 11:42:19 +020042
Jes Sorensence798cf2010-06-10 11:42:31 +020043#ifdef CONFIG_LINUX
44#include <sys/prctl.h>
Jes Sorensen949d31e2010-10-26 10:39:22 +020045#endif
46
Jes Sorensen8847cfe2010-06-10 11:42:26 +020047static struct passwd *user_pwd;
Jes Sorensen07663792010-06-10 11:42:27 +020048static const char *chroot_dir;
Jes Sorenseneb505be2010-06-10 11:42:28 +020049static int daemonize;
Michael Tokarev0be5e432014-10-30 17:30:51 +030050static int daemon_pipe;
Jes Sorensen8847cfe2010-06-10 11:42:26 +020051
Jes Sorensenfe98ac12010-06-10 11:42:21 +020052void os_setup_early_signal_handling(void)
Jes Sorensen86b645e2010-06-10 11:42:19 +020053{
54 struct sigaction act;
55 sigfillset(&act.sa_mask);
56 act.sa_flags = 0;
57 act.sa_handler = SIG_IGN;
58 sigaction(SIGPIPE, &act, NULL);
59}
Jes Sorensen8d963e62010-06-10 11:42:22 +020060
Gleb Natapovf64622c2011-03-15 13:56:04 +020061static void termsig_handler(int signal, siginfo_t *info, void *c)
Jes Sorensen8d963e62010-06-10 11:42:22 +020062{
Gleb Natapovf64622c2011-03-15 13:56:04 +020063 qemu_system_killed(info->si_signo, info->si_pid);
Jes Sorensen8d963e62010-06-10 11:42:22 +020064}
65
Jes Sorensen8d963e62010-06-10 11:42:22 +020066void os_setup_signal_handling(void)
67{
68 struct sigaction act;
69
70 memset(&act, 0, sizeof(act));
Gleb Natapovf64622c2011-03-15 13:56:04 +020071 act.sa_sigaction = termsig_handler;
72 act.sa_flags = SA_SIGINFO;
Jes Sorensen8d963e62010-06-10 11:42:22 +020073 sigaction(SIGINT, &act, NULL);
74 sigaction(SIGHUP, &act, NULL);
75 sigaction(SIGTERM, &act, NULL);
Jes Sorensen8d963e62010-06-10 11:42:22 +020076}
Jes Sorensen61705402010-06-10 11:42:23 +020077
78/* Find a likely location for support files using the location of the binary.
79 For installed binaries this will be "$bindir/../share/qemu". When
80 running from the build tree this will be "$bindir/../pc-bios". */
81#define SHARE_SUFFIX "/share/qemu"
82#define BUILD_SUFFIX "/pc-bios"
Fam Zheng10f5bff2014-02-10 14:48:51 +080083char *os_find_datadir(void)
Jes Sorensen61705402010-06-10 11:42:23 +020084{
Fam Zheng10f5bff2014-02-10 14:48:51 +080085 char *dir, *exec_dir;
Jes Sorensen61705402010-06-10 11:42:23 +020086 char *res;
Jes Sorensen61705402010-06-10 11:42:23 +020087 size_t max_len;
88
Fam Zheng10f5bff2014-02-10 14:48:51 +080089 exec_dir = qemu_get_exec_dir();
90 if (exec_dir == NULL) {
91 return NULL;
Jes Sorensen61705402010-06-10 11:42:23 +020092 }
Fam Zheng10f5bff2014-02-10 14:48:51 +080093 dir = dirname(exec_dir);
Jes Sorensen61705402010-06-10 11:42:23 +020094
95 max_len = strlen(dir) +
96 MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
Anthony Liguori7267c092011-08-20 22:09:37 -050097 res = g_malloc0(max_len);
Jes Sorensen61705402010-06-10 11:42:23 +020098 snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX);
99 if (access(res, R_OK)) {
100 snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX);
101 if (access(res, R_OK)) {
Anthony Liguori7267c092011-08-20 22:09:37 -0500102 g_free(res);
Jes Sorensen61705402010-06-10 11:42:23 +0200103 res = NULL;
104 }
105 }
106
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:
141 if (net_slirp_smb(optarg) < 0)
142 exit(1);
143 break;
144#endif
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200145 case QEMU_OPTION_runas:
146 user_pwd = getpwnam(optarg);
147 if (!user_pwd) {
148 fprintf(stderr, "User \"%s\" doesn't exist\n", optarg);
149 exit(1);
150 }
151 break;
Jes Sorensen07663792010-06-10 11:42:27 +0200152 case QEMU_OPTION_chroot:
153 chroot_dir = optarg;
154 break;
Jes Sorenseneb505be2010-06-10 11:42:28 +0200155 case QEMU_OPTION_daemonize:
156 daemonize = 1;
157 break;
Anthony Liguori70678b82012-08-03 18:28:37 -0500158#if defined(CONFIG_LINUX)
159 case QEMU_OPTION_enablefips:
160 fips_set_state(true);
161 break;
162#endif
Jes Sorensen59a52642010-06-10 11:42:25 +0200163 }
Jes Sorensen59a52642010-06-10 11:42:25 +0200164}
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200165
Jes Sorensene06eb602010-06-10 11:42:29 +0200166static void change_process_uid(void)
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200167{
168 if (user_pwd) {
169 if (setgid(user_pwd->pw_gid) < 0) {
170 fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
171 exit(1);
172 }
Stefan Hajnoczicc4662f2011-07-09 10:22:07 +0100173 if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
174 fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n",
175 user_pwd->pw_name, user_pwd->pw_gid);
176 exit(1);
177 }
Jes Sorensen8847cfe2010-06-10 11:42:26 +0200178 if (setuid(user_pwd->pw_uid) < 0) {
179 fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
180 exit(1);
181 }
182 if (setuid(0) != -1) {
183 fprintf(stderr, "Dropping privileges failed\n");
184 exit(1);
185 }
186 }
187}
Jes Sorensen07663792010-06-10 11:42:27 +0200188
Jes Sorensene06eb602010-06-10 11:42:29 +0200189static void change_root(void)
Jes Sorensen07663792010-06-10 11:42:27 +0200190{
191 if (chroot_dir) {
192 if (chroot(chroot_dir) < 0) {
193 fprintf(stderr, "chroot failed\n");
194 exit(1);
195 }
196 if (chdir("/")) {
197 perror("not able to chdir to /");
198 exit(1);
199 }
200 }
201
202}
Jes Sorenseneb505be2010-06-10 11:42:28 +0200203
204void os_daemonize(void)
205{
206 if (daemonize) {
Gonglei63ce8e12014-09-26 16:14:30 +0800207 pid_t pid;
Michael Tokarev0be5e432014-10-30 17:30:51 +0300208 int fds[2];
Jes Sorenseneb505be2010-06-10 11:42:28 +0200209
Gonglei63ce8e12014-09-26 16:14:30 +0800210 if (pipe(fds) == -1) {
211 exit(1);
212 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200213
Gonglei63ce8e12014-09-26 16:14:30 +0800214 pid = fork();
215 if (pid > 0) {
216 uint8_t status;
217 ssize_t len;
Jes Sorenseneb505be2010-06-10 11:42:28 +0200218
Gonglei63ce8e12014-09-26 16:14:30 +0800219 close(fds[1]);
Jes Sorenseneb505be2010-06-10 11:42:28 +0200220
Michael Tokarevccea25f2014-10-30 17:37:16 +0300221 do {
222 len = read(fds[0], &status, 1);
223 } while (len < 0 && errno == EINTR);
Michael Tokarevfee78fd2014-10-30 17:40:48 +0300224
225 /* only exit successfully if our child actually wrote
226 * a one-byte zero to our pipe, upon successful init */
227 exit(len == 1 && status == 0 ? 0 : 1);
228
229 } else if (pid < 0) {
230 exit(1);
231 }
Gonglei63ce8e12014-09-26 16:14:30 +0800232
233 close(fds[0]);
Michael Tokarev0be5e432014-10-30 17:30:51 +0300234 daemon_pipe = fds[1];
235 qemu_set_cloexec(daemon_pipe);
Gonglei63ce8e12014-09-26 16:14:30 +0800236
237 setsid();
238
239 pid = fork();
240 if (pid > 0) {
241 exit(0);
242 } else if (pid < 0) {
Jes Sorenseneb505be2010-06-10 11:42:28 +0200243 exit(1);
Gonglei63ce8e12014-09-26 16:14:30 +0800244 }
245 umask(027);
Jes Sorenseneb505be2010-06-10 11:42:28 +0200246
247 signal(SIGTSTP, SIG_IGN);
248 signal(SIGTTOU, SIG_IGN);
249 signal(SIGTTIN, SIG_IGN);
250 }
251}
252
253void os_setup_post(void)
254{
255 int fd = 0;
256
257 if (daemonize) {
Jes Sorenseneb505be2010-06-10 11:42:28 +0200258 if (chdir("/")) {
259 perror("not able to chdir to /");
260 exit(1);
261 }
Gonglei63ce8e12014-09-26 16:14:30 +0800262 TFR(fd = qemu_open("/dev/null", O_RDWR));
263 if (fd == -1) {
264 exit(1);
265 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200266 }
267
Jes Sorensene06eb602010-06-10 11:42:29 +0200268 change_root();
269 change_process_uid();
Jes Sorenseneb505be2010-06-10 11:42:28 +0200270
271 if (daemonize) {
Michael Tokarev25cec2b2014-10-30 17:47:46 +0300272 uint8_t status = 0;
273 ssize_t len;
274
Jes Sorenseneb505be2010-06-10 11:42:28 +0200275 dup2(fd, 0);
276 dup2(fd, 1);
277 dup2(fd, 2);
278
279 close(fd);
Michael Tokarev25cec2b2014-10-30 17:47:46 +0300280
281 do {
282 len = write(daemon_pipe, &status, 1);
283 } while (len < 0 && errno == EINTR);
284 if (len != 1) {
285 exit(1);
286 }
Jes Sorenseneb505be2010-06-10 11:42:28 +0200287 }
288}
289
Jes Sorensen9156d762010-06-10 11:42:30 +0200290void os_set_line_buffering(void)
291{
292 setvbuf(stdout, NULL, _IOLBF, 0);
293}
Jes Sorensen949d31e2010-10-26 10:39:22 +0200294
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200295int qemu_create_pidfile(const char *filename)
296{
297 char buffer[128];
298 int len;
299 int fd;
300
301 fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
302 if (fd == -1) {
303 return -1;
304 }
305 if (lockf(fd, F_TLOCK, 0) == -1) {
Markus Armbruster1bbd1592011-11-11 10:40:09 +0100306 close(fd);
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200307 return -1;
308 }
Andreas Färber953ffe02011-06-02 19:58:06 +0200309 len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200310 if (write(fd, buffer, len) != len) {
Markus Armbruster1bbd1592011-11-11 10:40:09 +0100311 close(fd);
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200312 return -1;
313 }
314
Laszlo Ersek93dd7482012-01-27 14:34:05 +0100315 /* keep pidfile open & locked forever */
Jes Sorensenbc4a9572010-10-26 10:39:25 +0200316 return 0;
317}
Hitoshi Mitake995ee2b2012-09-15 01:15:41 +0900318
319bool is_daemonized(void)
320{
321 return daemonize;
322}
Satoru Moriya888a6bc2013-04-19 16:42:06 +0200323
324int os_mlock(void)
325{
326 int ret = 0;
327
328 ret = mlockall(MCL_CURRENT | MCL_FUTURE);
329 if (ret < 0) {
330 perror("mlockall");
331 }
332
333 return ret;
334}