]>
Commit | Line | Data |
---|---|---|
86b645e7 JS |
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 | ||
d38ea87a | 26 | #include "qemu/osdep.h" |
8d963e6a | 27 | #include <sys/wait.h> |
8847cfe8 | 28 | #include <pwd.h> |
cc4662f9 | 29 | #include <grp.h> |
6170540b | 30 | #include <libgen.h> |
86b645e7 JS |
31 | |
32 | /* Needed early for CONFIG_BSD etc. */ | |
59a5264b | 33 | #include "net/slirp.h" |
fd5fc4b1 | 34 | #include "qemu/qemu-options.h" |
f853ac66 | 35 | #include "qemu/error-report.h" |
96c33a45 | 36 | #include "qemu/log.h" |
54d31236 | 37 | #include "sysemu/runstate.h" |
f348b6d1 | 38 | #include "qemu/cutils.h" |
80bd81ca CI |
39 | #include "qemu/config-file.h" |
40 | #include "qemu/option.h" | |
9ffcbe2a | 41 | #include "qemu/module.h" |
86b645e7 | 42 | |
ce798cf2 JS |
43 | #ifdef CONFIG_LINUX |
44 | #include <sys/prctl.h> | |
c891c24b | 45 | #include "qemu/async-teardown.h" |
949d31e6 JS |
46 | #endif |
47 | ||
2c42f1e8 IJ |
48 | /* |
49 | * Must set all three of these at once. | |
50 | * Legal combinations are unset by name by uid | |
51 | */ | |
52 | static struct passwd *user_pwd; /* NULL non-NULL NULL */ | |
53 | static uid_t user_uid = (uid_t)-1; /* -1 -1 >=0 */ | |
54 | static gid_t user_gid = (gid_t)-1; /* -1 -1 >=0 */ | |
55 | ||
0766379d | 56 | static const char *chroot_dir; |
eb505be1 | 57 | static int daemonize; |
0be5e436 | 58 | static int daemon_pipe; |
8847cfe8 | 59 | |
fe98ac14 | 60 | void os_setup_early_signal_handling(void) |
86b645e7 JS |
61 | { |
62 | struct sigaction act; | |
63 | sigfillset(&act.sa_mask); | |
64 | act.sa_flags = 0; | |
65 | act.sa_handler = SIG_IGN; | |
66 | sigaction(SIGPIPE, &act, NULL); | |
67 | } | |
8d963e6a | 68 | |
f64622c4 | 69 | static void termsig_handler(int signal, siginfo_t *info, void *c) |
8d963e6a | 70 | { |
f64622c4 | 71 | qemu_system_killed(info->si_signo, info->si_pid); |
8d963e6a JS |
72 | } |
73 | ||
8d963e6a JS |
74 | void os_setup_signal_handling(void) |
75 | { | |
76 | struct sigaction act; | |
77 | ||
78 | memset(&act, 0, sizeof(act)); | |
f64622c4 GN |
79 | act.sa_sigaction = termsig_handler; |
80 | act.sa_flags = SA_SIGINFO; | |
8d963e6a JS |
81 | sigaction(SIGINT, &act, NULL); |
82 | sigaction(SIGHUP, &act, NULL); | |
83 | sigaction(SIGTERM, &act, NULL); | |
8d963e6a | 84 | } |
6170540b | 85 | |
ce798cf2 JS |
86 | void os_set_proc_name(const char *s) |
87 | { | |
88 | #if defined(PR_SET_NAME) | |
89 | char name[16]; | |
90 | if (!s) | |
91 | return; | |
3eadc68e | 92 | pstrcpy(name, sizeof(name), s); |
ce798cf2 JS |
93 | /* Could rewrite argv[0] too, but that's a bit more complicated. |
94 | This simple way is enough for `top'. */ | |
95 | if (prctl(PR_SET_NAME, name)) { | |
a7aaec14 | 96 | error_report("unable to change process name: %s", strerror(errno)); |
ce798cf2 JS |
97 | exit(1); |
98 | } | |
99 | #else | |
22cd4f48 | 100 | error_report("Change of process name not supported by your OS"); |
ce798cf2 JS |
101 | exit(1); |
102 | #endif | |
103 | } | |
104 | ||
2c42f1e8 IJ |
105 | |
106 | static bool os_parse_runas_uid_gid(const char *optarg) | |
107 | { | |
108 | unsigned long lv; | |
109 | const char *ep; | |
110 | uid_t got_uid; | |
111 | gid_t got_gid; | |
112 | int rc; | |
113 | ||
114 | rc = qemu_strtoul(optarg, &ep, 0, &lv); | |
115 | got_uid = lv; /* overflow here is ID in C99 */ | |
116 | if (rc || *ep != ':' || got_uid != lv || got_uid == (uid_t)-1) { | |
117 | return false; | |
118 | } | |
119 | ||
120 | rc = qemu_strtoul(ep + 1, 0, 0, &lv); | |
121 | got_gid = lv; /* overflow here is ID in C99 */ | |
122 | if (rc || got_gid != lv || got_gid == (gid_t)-1) { | |
123 | return false; | |
124 | } | |
125 | ||
126 | user_pwd = NULL; | |
127 | user_uid = got_uid; | |
128 | user_gid = got_gid; | |
129 | return true; | |
130 | } | |
131 | ||
59a5264b JS |
132 | /* |
133 | * Parse OS specific command line options. | |
134 | * return 0 if option handled, -1 otherwise | |
135 | */ | |
1217d6ca | 136 | int os_parse_cmd_args(int index, const char *optarg) |
59a5264b JS |
137 | { |
138 | switch (index) { | |
8847cfe8 JS |
139 | case QEMU_OPTION_runas: |
140 | user_pwd = getpwnam(optarg); | |
2c42f1e8 IJ |
141 | if (user_pwd) { |
142 | user_uid = -1; | |
143 | user_gid = -1; | |
144 | } else if (!os_parse_runas_uid_gid(optarg)) { | |
145 | error_report("User \"%s\" doesn't exist" | |
146 | " (and is not <uid>:<gid>)", | |
147 | optarg); | |
8847cfe8 JS |
148 | exit(1); |
149 | } | |
150 | break; | |
0766379d | 151 | case QEMU_OPTION_chroot: |
9ffcbe2a | 152 | warn_report("option is deprecated, use '-run-with chroot=...' instead"); |
0766379d JS |
153 | chroot_dir = optarg; |
154 | break; | |
eb505be1 JS |
155 | case QEMU_OPTION_daemonize: |
156 | daemonize = 1; | |
157 | break; | |
c891c24b | 158 | #if defined(CONFIG_LINUX) |
80bd81ca | 159 | /* deprecated */ |
c891c24b CI |
160 | case QEMU_OPTION_asyncteardown: |
161 | init_async_teardown(); | |
162 | break; | |
9ffcbe2a | 163 | #endif |
80bd81ca | 164 | case QEMU_OPTION_run_with: { |
9ffcbe2a | 165 | const char *str; |
80bd81ca CI |
166 | QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("run-with"), |
167 | optarg, false); | |
168 | if (!opts) { | |
169 | exit(1); | |
170 | } | |
9ffcbe2a | 171 | #if defined(CONFIG_LINUX) |
80bd81ca CI |
172 | if (qemu_opt_get_bool(opts, "async-teardown", false)) { |
173 | init_async_teardown(); | |
174 | } | |
9ffcbe2a TH |
175 | #endif |
176 | str = qemu_opt_get(opts, "chroot"); | |
177 | if (str) { | |
178 | chroot_dir = str; | |
179 | } | |
80bd81ca CI |
180 | break; |
181 | } | |
1217d6ca TH |
182 | default: |
183 | return -1; | |
59a5264b | 184 | } |
1217d6ca TH |
185 | |
186 | return 0; | |
59a5264b | 187 | } |
8847cfe8 | 188 | |
e06eb601 | 189 | static void change_process_uid(void) |
8847cfe8 | 190 | { |
2c42f1e8 IJ |
191 | assert((user_uid == (uid_t)-1) || user_pwd == NULL); |
192 | assert((user_uid == (uid_t)-1) == | |
193 | (user_gid == (gid_t)-1)); | |
194 | ||
195 | if (user_pwd || user_uid != (uid_t)-1) { | |
196 | gid_t intended_gid = user_pwd ? user_pwd->pw_gid : user_gid; | |
197 | uid_t intended_uid = user_pwd ? user_pwd->pw_uid : user_uid; | |
198 | if (setgid(intended_gid) < 0) { | |
199 | error_report("Failed to setgid(%d)", intended_gid); | |
8847cfe8 JS |
200 | exit(1); |
201 | } | |
2c42f1e8 IJ |
202 | if (user_pwd) { |
203 | if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) { | |
204 | error_report("Failed to initgroups(\"%s\", %d)", | |
205 | user_pwd->pw_name, user_pwd->pw_gid); | |
206 | exit(1); | |
207 | } | |
208 | } else { | |
209 | if (setgroups(1, &user_gid) < 0) { | |
210 | error_report("Failed to setgroups(1, [%d])", | |
211 | user_gid); | |
212 | exit(1); | |
213 | } | |
cc4662f9 | 214 | } |
2c42f1e8 IJ |
215 | if (setuid(intended_uid) < 0) { |
216 | error_report("Failed to setuid(%d)", intended_uid); | |
8847cfe8 JS |
217 | exit(1); |
218 | } | |
219 | if (setuid(0) != -1) { | |
f0a2171b | 220 | error_report("Dropping privileges failed"); |
8847cfe8 JS |
221 | exit(1); |
222 | } | |
223 | } | |
224 | } | |
0766379d | 225 | |
e06eb601 | 226 | static void change_root(void) |
0766379d JS |
227 | { |
228 | if (chroot_dir) { | |
229 | if (chroot(chroot_dir) < 0) { | |
22cd4f48 | 230 | error_report("chroot failed"); |
0766379d JS |
231 | exit(1); |
232 | } | |
233 | if (chdir("/")) { | |
a7aaec14 | 234 | error_report("not able to chdir to /: %s", strerror(errno)); |
0766379d JS |
235 | exit(1); |
236 | } | |
237 | } | |
238 | ||
239 | } | |
eb505be1 JS |
240 | |
241 | void os_daemonize(void) | |
242 | { | |
243 | if (daemonize) { | |
63ce8e15 | 244 | pid_t pid; |
0be5e436 | 245 | int fds[2]; |
eb505be1 | 246 | |
3338a41f | 247 | if (!g_unix_open_pipe(fds, FD_CLOEXEC, NULL)) { |
63ce8e15 GA |
248 | exit(1); |
249 | } | |
eb505be1 | 250 | |
63ce8e15 GA |
251 | pid = fork(); |
252 | if (pid > 0) { | |
253 | uint8_t status; | |
254 | ssize_t len; | |
eb505be1 | 255 | |
63ce8e15 | 256 | close(fds[1]); |
eb505be1 | 257 | |
ccea25f1 MT |
258 | do { |
259 | len = read(fds[0], &status, 1); | |
260 | } while (len < 0 && errno == EINTR); | |
fee78fd6 MT |
261 | |
262 | /* only exit successfully if our child actually wrote | |
263 | * a one-byte zero to our pipe, upon successful init */ | |
264 | exit(len == 1 && status == 0 ? 0 : 1); | |
265 | ||
266 | } else if (pid < 0) { | |
267 | exit(1); | |
268 | } | |
eb505be1 | 269 | |
63ce8e15 | 270 | close(fds[0]); |
0be5e436 | 271 | daemon_pipe = fds[1]; |
eb505be1 | 272 | |
63ce8e15 | 273 | setsid(); |
eb505be1 | 274 | |
63ce8e15 GA |
275 | pid = fork(); |
276 | if (pid > 0) { | |
277 | exit(0); | |
278 | } else if (pid < 0) { | |
279 | exit(1); | |
280 | } | |
281 | umask(027); | |
eb505be1 JS |
282 | |
283 | signal(SIGTSTP, SIG_IGN); | |
284 | signal(SIGTTOU, SIG_IGN); | |
285 | signal(SIGTTIN, SIG_IGN); | |
286 | } | |
287 | } | |
288 | ||
289 | void os_setup_post(void) | |
290 | { | |
291 | int fd = 0; | |
292 | ||
293 | if (daemonize) { | |
eb505be1 | 294 | if (chdir("/")) { |
a7aaec14 | 295 | error_report("not able to chdir to /: %s", strerror(errno)); |
eb505be1 JS |
296 | exit(1); |
297 | } | |
8b6aa693 | 298 | fd = RETRY_ON_EINTR(qemu_open_old("/dev/null", O_RDWR)); |
63ce8e15 GA |
299 | if (fd == -1) { |
300 | exit(1); | |
301 | } | |
eb505be1 JS |
302 | } |
303 | ||
e06eb601 JS |
304 | change_root(); |
305 | change_process_uid(); | |
eb505be1 JS |
306 | |
307 | if (daemonize) { | |
25cec2b8 MT |
308 | uint8_t status = 0; |
309 | ssize_t len; | |
310 | ||
eb505be1 JS |
311 | dup2(fd, 0); |
312 | dup2(fd, 1); | |
96c33a45 | 313 | /* In case -D is given do not redirect stderr to /dev/null */ |
229ef2eb | 314 | if (!qemu_log_enabled()) { |
96c33a45 DA |
315 | dup2(fd, 2); |
316 | } | |
eb505be1 JS |
317 | |
318 | close(fd); | |
25cec2b8 MT |
319 | |
320 | do { | |
321 | len = write(daemon_pipe, &status, 1); | |
322 | } while (len < 0 && errno == EINTR); | |
323 | if (len != 1) { | |
324 | exit(1); | |
325 | } | |
eb505be1 JS |
326 | } |
327 | } | |
328 | ||
9156d763 JS |
329 | void os_set_line_buffering(void) |
330 | { | |
331 | setvbuf(stdout, NULL, _IOLBF, 0); | |
332 | } | |
949d31e6 | 333 | |
995ee2bf HM |
334 | bool is_daemonized(void) |
335 | { | |
336 | return daemonize; | |
337 | } | |
888a6bc6 | 338 | |
f22ac472 HR |
339 | int os_set_daemonize(bool d) |
340 | { | |
341 | daemonize = d; | |
342 | return 0; | |
343 | } | |
344 | ||
888a6bc6 SM |
345 | int os_mlock(void) |
346 | { | |
195588cc | 347 | #ifdef HAVE_MLOCKALL |
888a6bc6 SM |
348 | int ret = 0; |
349 | ||
350 | ret = mlockall(MCL_CURRENT | MCL_FUTURE); | |
351 | if (ret < 0) { | |
a7aaec14 | 352 | error_report("mlockall: %s", strerror(errno)); |
888a6bc6 SM |
353 | } |
354 | ||
355 | return ret; | |
195588cc DC |
356 | #else |
357 | return -ENOSYS; | |
358 | #endif | |
888a6bc6 | 359 | } |
9ffcbe2a TH |
360 | |
361 | static QemuOptsList qemu_run_with_opts = { | |
362 | .name = "run-with", | |
363 | .head = QTAILQ_HEAD_INITIALIZER(qemu_run_with_opts.head), | |
364 | .desc = { | |
365 | #if defined(CONFIG_LINUX) | |
366 | { | |
367 | .name = "async-teardown", | |
368 | .type = QEMU_OPT_BOOL, | |
369 | }, | |
370 | #endif | |
371 | { | |
372 | .name = "chroot", | |
373 | .type = QEMU_OPT_STRING, | |
374 | }, | |
375 | { /* end of list */ } | |
376 | }, | |
377 | }; | |
378 | ||
379 | static void register_runwith(void) | |
380 | { | |
381 | qemu_add_opts(&qemu_run_with_opts); | |
382 | } | |
383 | opts_init(register_runwith); |