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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 | ||
26 | #include <unistd.h> | |
27 | #include <fcntl.h> | |
28 | #include <signal.h> | |
8d963e6a JS |
29 | #include <sys/types.h> |
30 | #include <sys/wait.h> | |
69e8b162 JS |
31 | /*needed for MAP_POPULATE before including qemu-options.h */ |
32 | #include <sys/mman.h> | |
8847cfe8 | 33 | #include <pwd.h> |
cc4662f9 | 34 | #include <grp.h> |
6170540b | 35 | #include <libgen.h> |
86b645e7 JS |
36 | |
37 | /* Needed early for CONFIG_BSD etc. */ | |
38 | #include "config-host.h" | |
9c17d615 | 39 | #include "sysemu/sysemu.h" |
59a5264b JS |
40 | #include "net/slirp.h" |
41 | #include "qemu-options.h" | |
a59629fc | 42 | #include "qemu/rcu.h" |
f853ac66 | 43 | #include "qemu/error-report.h" |
86b645e7 | 44 | |
ce798cf2 JS |
45 | #ifdef CONFIG_LINUX |
46 | #include <sys/prctl.h> | |
949d31e6 JS |
47 | #endif |
48 | ||
8847cfe8 | 49 | static struct passwd *user_pwd; |
0766379d | 50 | static const char *chroot_dir; |
eb505be1 | 51 | static int daemonize; |
0be5e436 | 52 | static int daemon_pipe; |
8847cfe8 | 53 | |
fe98ac14 | 54 | void os_setup_early_signal_handling(void) |
86b645e7 JS |
55 | { |
56 | struct sigaction act; | |
57 | sigfillset(&act.sa_mask); | |
58 | act.sa_flags = 0; | |
59 | act.sa_handler = SIG_IGN; | |
60 | sigaction(SIGPIPE, &act, NULL); | |
61 | } | |
8d963e6a | 62 | |
f64622c4 | 63 | static void termsig_handler(int signal, siginfo_t *info, void *c) |
8d963e6a | 64 | { |
f64622c4 | 65 | qemu_system_killed(info->si_signo, info->si_pid); |
8d963e6a JS |
66 | } |
67 | ||
8d963e6a JS |
68 | void os_setup_signal_handling(void) |
69 | { | |
70 | struct sigaction act; | |
71 | ||
72 | memset(&act, 0, sizeof(act)); | |
f64622c4 GN |
73 | act.sa_sigaction = termsig_handler; |
74 | act.sa_flags = SA_SIGINFO; | |
8d963e6a JS |
75 | sigaction(SIGINT, &act, NULL); |
76 | sigaction(SIGHUP, &act, NULL); | |
77 | sigaction(SIGTERM, &act, NULL); | |
8d963e6a | 78 | } |
6170540b JS |
79 | |
80 | /* Find a likely location for support files using the location of the binary. | |
81 | For installed binaries this will be "$bindir/../share/qemu". When | |
82 | running from the build tree this will be "$bindir/../pc-bios". */ | |
83 | #define SHARE_SUFFIX "/share/qemu" | |
84 | #define BUILD_SUFFIX "/pc-bios" | |
10f5bff6 | 85 | char *os_find_datadir(void) |
6170540b | 86 | { |
10f5bff6 | 87 | char *dir, *exec_dir; |
6170540b | 88 | char *res; |
6170540b JS |
89 | size_t max_len; |
90 | ||
10f5bff6 FZ |
91 | exec_dir = qemu_get_exec_dir(); |
92 | if (exec_dir == NULL) { | |
93 | return NULL; | |
6170540b | 94 | } |
10f5bff6 | 95 | dir = dirname(exec_dir); |
6170540b JS |
96 | |
97 | max_len = strlen(dir) + | |
98 | MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1; | |
7267c094 | 99 | res = g_malloc0(max_len); |
6170540b JS |
100 | snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX); |
101 | if (access(res, R_OK)) { | |
102 | snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX); | |
103 | if (access(res, R_OK)) { | |
7267c094 | 104 | g_free(res); |
6170540b JS |
105 | res = NULL; |
106 | } | |
107 | } | |
108 | ||
10f5bff6 | 109 | g_free(exec_dir); |
6170540b JS |
110 | return res; |
111 | } | |
112 | #undef SHARE_SUFFIX | |
113 | #undef BUILD_SUFFIX | |
59a5264b | 114 | |
ce798cf2 JS |
115 | void os_set_proc_name(const char *s) |
116 | { | |
117 | #if defined(PR_SET_NAME) | |
118 | char name[16]; | |
119 | if (!s) | |
120 | return; | |
3eadc68e | 121 | pstrcpy(name, sizeof(name), s); |
ce798cf2 JS |
122 | /* Could rewrite argv[0] too, but that's a bit more complicated. |
123 | This simple way is enough for `top'. */ | |
124 | if (prctl(PR_SET_NAME, name)) { | |
125 | perror("unable to change process name"); | |
126 | exit(1); | |
127 | } | |
128 | #else | |
129 | fprintf(stderr, "Change of process name not supported by your OS\n"); | |
130 | exit(1); | |
131 | #endif | |
132 | } | |
133 | ||
59a5264b JS |
134 | /* |
135 | * Parse OS specific command line options. | |
136 | * return 0 if option handled, -1 otherwise | |
137 | */ | |
138 | void os_parse_cmd_args(int index, const char *optarg) | |
139 | { | |
140 | switch (index) { | |
141 | #ifdef CONFIG_SLIRP | |
142 | case QEMU_OPTION_smb: | |
f853ac66 TH |
143 | error_report("The -smb option is deprecated. " |
144 | "Please use '-netdev user,smb=...' instead."); | |
59a5264b JS |
145 | if (net_slirp_smb(optarg) < 0) |
146 | exit(1); | |
147 | break; | |
148 | #endif | |
8847cfe8 JS |
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; | |
0766379d JS |
156 | case QEMU_OPTION_chroot: |
157 | chroot_dir = optarg; | |
158 | break; | |
eb505be1 JS |
159 | case QEMU_OPTION_daemonize: |
160 | daemonize = 1; | |
161 | break; | |
70678b82 AL |
162 | #if defined(CONFIG_LINUX) |
163 | case QEMU_OPTION_enablefips: | |
164 | fips_set_state(true); | |
165 | break; | |
166 | #endif | |
59a5264b | 167 | } |
59a5264b | 168 | } |
8847cfe8 | 169 | |
e06eb601 | 170 | static void change_process_uid(void) |
8847cfe8 JS |
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 | } | |
cc4662f9 SH |
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 | } | |
8847cfe8 JS |
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 | } | |
0766379d | 192 | |
e06eb601 | 193 | static void change_root(void) |
0766379d JS |
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 | } | |
eb505be1 JS |
207 | |
208 | void os_daemonize(void) | |
209 | { | |
210 | if (daemonize) { | |
63ce8e15 | 211 | pid_t pid; |
0be5e436 | 212 | int fds[2]; |
eb505be1 | 213 | |
63ce8e15 GA |
214 | if (pipe(fds) == -1) { |
215 | exit(1); | |
216 | } | |
eb505be1 | 217 | |
63ce8e15 GA |
218 | pid = fork(); |
219 | if (pid > 0) { | |
220 | uint8_t status; | |
221 | ssize_t len; | |
eb505be1 | 222 | |
63ce8e15 | 223 | close(fds[1]); |
eb505be1 | 224 | |
ccea25f1 MT |
225 | do { |
226 | len = read(fds[0], &status, 1); | |
227 | } while (len < 0 && errno == EINTR); | |
fee78fd6 MT |
228 | |
229 | /* only exit successfully if our child actually wrote | |
230 | * a one-byte zero to our pipe, upon successful init */ | |
231 | exit(len == 1 && status == 0 ? 0 : 1); | |
232 | ||
233 | } else if (pid < 0) { | |
234 | exit(1); | |
235 | } | |
eb505be1 | 236 | |
63ce8e15 | 237 | close(fds[0]); |
0be5e436 MT |
238 | daemon_pipe = fds[1]; |
239 | qemu_set_cloexec(daemon_pipe); | |
eb505be1 | 240 | |
63ce8e15 | 241 | setsid(); |
eb505be1 | 242 | |
63ce8e15 GA |
243 | pid = fork(); |
244 | if (pid > 0) { | |
245 | exit(0); | |
246 | } else if (pid < 0) { | |
247 | exit(1); | |
248 | } | |
249 | umask(027); | |
eb505be1 JS |
250 | |
251 | signal(SIGTSTP, SIG_IGN); | |
252 | signal(SIGTTOU, SIG_IGN); | |
253 | signal(SIGTTIN, SIG_IGN); | |
a59629fc | 254 | rcu_after_fork(); |
eb505be1 JS |
255 | } |
256 | } | |
257 | ||
258 | void os_setup_post(void) | |
259 | { | |
260 | int fd = 0; | |
261 | ||
262 | if (daemonize) { | |
eb505be1 JS |
263 | if (chdir("/")) { |
264 | perror("not able to chdir to /"); | |
265 | exit(1); | |
266 | } | |
63ce8e15 GA |
267 | TFR(fd = qemu_open("/dev/null", O_RDWR)); |
268 | if (fd == -1) { | |
269 | exit(1); | |
270 | } | |
eb505be1 JS |
271 | } |
272 | ||
e06eb601 JS |
273 | change_root(); |
274 | change_process_uid(); | |
eb505be1 JS |
275 | |
276 | if (daemonize) { | |
25cec2b8 MT |
277 | uint8_t status = 0; |
278 | ssize_t len; | |
279 | ||
eb505be1 JS |
280 | dup2(fd, 0); |
281 | dup2(fd, 1); | |
282 | dup2(fd, 2); | |
283 | ||
284 | close(fd); | |
25cec2b8 MT |
285 | |
286 | do { | |
287 | len = write(daemon_pipe, &status, 1); | |
288 | } while (len < 0 && errno == EINTR); | |
289 | if (len != 1) { | |
290 | exit(1); | |
291 | } | |
eb505be1 JS |
292 | } |
293 | } | |
294 | ||
9156d763 JS |
295 | void os_set_line_buffering(void) |
296 | { | |
297 | setvbuf(stdout, NULL, _IOLBF, 0); | |
298 | } | |
949d31e6 | 299 | |
bc4a957c JS |
300 | int qemu_create_pidfile(const char *filename) |
301 | { | |
302 | char buffer[128]; | |
303 | int len; | |
304 | int fd; | |
305 | ||
306 | fd = qemu_open(filename, O_RDWR | O_CREAT, 0600); | |
307 | if (fd == -1) { | |
308 | return -1; | |
309 | } | |
310 | if (lockf(fd, F_TLOCK, 0) == -1) { | |
1bbd1592 | 311 | close(fd); |
bc4a957c JS |
312 | return -1; |
313 | } | |
953ffe0f | 314 | len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid()); |
bc4a957c | 315 | if (write(fd, buffer, len) != len) { |
1bbd1592 | 316 | close(fd); |
bc4a957c JS |
317 | return -1; |
318 | } | |
319 | ||
93dd748b | 320 | /* keep pidfile open & locked forever */ |
bc4a957c JS |
321 | return 0; |
322 | } | |
995ee2bf HM |
323 | |
324 | bool is_daemonized(void) | |
325 | { | |
326 | return daemonize; | |
327 | } | |
888a6bc6 SM |
328 | |
329 | int os_mlock(void) | |
330 | { | |
331 | int ret = 0; | |
332 | ||
333 | ret = mlockall(MCL_CURRENT | MCL_FUTURE); | |
334 | if (ret < 0) { | |
335 | perror("mlockall"); | |
336 | } | |
337 | ||
338 | return ret; | |
339 | } |