qom: Avoid leaking str and bool properties on failure
[qemu.git] / os-posix.c
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
26 #include <unistd.h>
27 #include <fcntl.h>
28 #include <signal.h>
29 #include <sys/types.h>
30 #include <sys/wait.h>
31 /*needed for MAP_POPULATE before including qemu-options.h */
32 #include <sys/mman.h>
33 #include <pwd.h>
34 #include <grp.h>
35 #include <libgen.h>
36
37 /* Needed early for CONFIG_BSD etc. */
38 #include "config-host.h"
39 #include "sysemu/sysemu.h"
40 #include "net/slirp.h"
41 #include "qemu-options.h"
42
43 #ifdef CONFIG_LINUX
44 #include <sys/prctl.h>
45 #endif
46
47 #ifdef __FreeBSD__
48 #include <sys/sysctl.h>
49 #endif
50
51 static struct passwd *user_pwd;
52 static const char *chroot_dir;
53 static int daemonize;
54 static int fds[2];
55
56 void os_setup_early_signal_handling(void)
57 {
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 }
64
65 static void termsig_handler(int signal, siginfo_t *info, void *c)
66 {
67 qemu_system_killed(info->si_signo, info->si_pid);
68 }
69
70 void os_setup_signal_handling(void)
71 {
72 struct sigaction act;
73
74 memset(&act, 0, sizeof(act));
75 act.sa_sigaction = termsig_handler;
76 act.sa_flags = SA_SIGINFO;
77 sigaction(SIGINT, &act, NULL);
78 sigaction(SIGHUP, &act, NULL);
79 sigaction(SIGTERM, &act, NULL);
80 }
81
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"
87 char *os_find_datadir(void)
88 {
89 char *dir, *exec_dir;
90 char *res;
91 size_t max_len;
92
93 exec_dir = qemu_get_exec_dir();
94 if (exec_dir == NULL) {
95 return NULL;
96 }
97 dir = dirname(exec_dir);
98
99 max_len = strlen(dir) +
100 MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
101 res = g_malloc0(max_len);
102 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)) {
106 g_free(res);
107 res = NULL;
108 }
109 }
110
111 g_free(exec_dir);
112 return res;
113 }
114 #undef SHARE_SUFFIX
115 #undef BUILD_SUFFIX
116
117 void os_set_proc_name(const char *s)
118 {
119 #if defined(PR_SET_NAME)
120 char name[16];
121 if (!s)
122 return;
123 pstrcpy(name, sizeof(name), s);
124 /* Could rewrite argv[0] too, but that's a bit more complicated.
125 This simple way is enough for `top'. */
126 if (prctl(PR_SET_NAME, name)) {
127 perror("unable to change process name");
128 exit(1);
129 }
130 #else
131 fprintf(stderr, "Change of process name not supported by your OS\n");
132 exit(1);
133 #endif
134 }
135
136 /*
137 * Parse OS specific command line options.
138 * return 0 if option handled, -1 otherwise
139 */
140 void os_parse_cmd_args(int index, const char *optarg)
141 {
142 switch (index) {
143 #ifdef CONFIG_SLIRP
144 case QEMU_OPTION_smb:
145 if (net_slirp_smb(optarg) < 0)
146 exit(1);
147 break;
148 #endif
149 case QEMU_OPTION_runas:
150 user_pwd = getpwnam(optarg);
151 if (!user_pwd) {
152 fprintf(stderr, "User \"%s\" doesn't exist\n", optarg);
153 exit(1);
154 }
155 break;
156 case QEMU_OPTION_chroot:
157 chroot_dir = optarg;
158 break;
159 case QEMU_OPTION_daemonize:
160 daemonize = 1;
161 break;
162 #if defined(CONFIG_LINUX)
163 case QEMU_OPTION_enablefips:
164 fips_set_state(true);
165 break;
166 #endif
167 }
168 }
169
170 static void change_process_uid(void)
171 {
172 if (user_pwd) {
173 if (setgid(user_pwd->pw_gid) < 0) {
174 fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
175 exit(1);
176 }
177 if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
178 fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n",
179 user_pwd->pw_name, user_pwd->pw_gid);
180 exit(1);
181 }
182 if (setuid(user_pwd->pw_uid) < 0) {
183 fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
184 exit(1);
185 }
186 if (setuid(0) != -1) {
187 fprintf(stderr, "Dropping privileges failed\n");
188 exit(1);
189 }
190 }
191 }
192
193 static void change_root(void)
194 {
195 if (chroot_dir) {
196 if (chroot(chroot_dir) < 0) {
197 fprintf(stderr, "chroot failed\n");
198 exit(1);
199 }
200 if (chdir("/")) {
201 perror("not able to chdir to /");
202 exit(1);
203 }
204 }
205
206 }
207
208 void os_daemonize(void)
209 {
210 if (daemonize) {
211 pid_t pid;
212
213 if (pipe(fds) == -1)
214 exit(1);
215
216 pid = fork();
217 if (pid > 0) {
218 uint8_t status;
219 ssize_t len;
220
221 close(fds[1]);
222
223 again:
224 len = read(fds[0], &status, 1);
225 if (len == -1 && (errno == EINTR))
226 goto again;
227
228 if (len != 1)
229 exit(1);
230 else if (status == 1) {
231 fprintf(stderr, "Could not acquire pidfile: %s\n", strerror(errno));
232 exit(1);
233 } else
234 exit(0);
235 } else if (pid < 0)
236 exit(1);
237
238 close(fds[0]);
239 qemu_set_cloexec(fds[1]);
240
241 setsid();
242
243 pid = fork();
244 if (pid > 0)
245 exit(0);
246 else if (pid < 0)
247 exit(1);
248
249 umask(027);
250
251 signal(SIGTSTP, SIG_IGN);
252 signal(SIGTTOU, SIG_IGN);
253 signal(SIGTTIN, SIG_IGN);
254 }
255 }
256
257 void os_setup_post(void)
258 {
259 int fd = 0;
260
261 if (daemonize) {
262 uint8_t status = 0;
263 ssize_t len;
264
265 again1:
266 len = write(fds[1], &status, 1);
267 if (len == -1 && (errno == EINTR))
268 goto again1;
269
270 if (len != 1)
271 exit(1);
272
273 if (chdir("/")) {
274 perror("not able to chdir to /");
275 exit(1);
276 }
277 TFR(fd = qemu_open("/dev/null", O_RDWR));
278 if (fd == -1)
279 exit(1);
280 }
281
282 change_root();
283 change_process_uid();
284
285 if (daemonize) {
286 dup2(fd, 0);
287 dup2(fd, 1);
288 dup2(fd, 2);
289
290 close(fd);
291 }
292 }
293
294 void os_pidfile_error(void)
295 {
296 if (daemonize) {
297 uint8_t status = 1;
298 if (write(fds[1], &status, 1) != 1) {
299 perror("daemonize. Writing to pipe\n");
300 }
301 } else
302 fprintf(stderr, "Could not acquire pid file: %s\n", strerror(errno));
303 }
304
305 void os_set_line_buffering(void)
306 {
307 setvbuf(stdout, NULL, _IOLBF, 0);
308 }
309
310 int qemu_create_pidfile(const char *filename)
311 {
312 char buffer[128];
313 int len;
314 int fd;
315
316 fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
317 if (fd == -1) {
318 return -1;
319 }
320 if (lockf(fd, F_TLOCK, 0) == -1) {
321 close(fd);
322 return -1;
323 }
324 len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
325 if (write(fd, buffer, len) != len) {
326 close(fd);
327 return -1;
328 }
329
330 /* keep pidfile open & locked forever */
331 return 0;
332 }
333
334 bool is_daemonized(void)
335 {
336 return daemonize;
337 }
338
339 int os_mlock(void)
340 {
341 int ret = 0;
342
343 ret = mlockall(MCL_CURRENT | MCL_FUTURE);
344 if (ret < 0) {
345 perror("mlockall");
346 }
347
348 return ret;
349 }