nbd: Don't use *_to_cpup() functions
[qemu.git] / util / oslib-posix.c
1 /*
2 * os-posix-lib.c
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2010 Red Hat, Inc.
6 *
7 * QEMU library functions on POSIX which are shared between QEMU and
8 * the QEMU tools.
9 *
10 * Permission is hereby granted, free of charge, to any person obtaining a copy
11 * of this software and associated documentation files (the "Software"), to deal
12 * in the Software without restriction, including without limitation the rights
13 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14 * copies of the Software, and to permit persons to whom the Software is
15 * furnished to do so, subject to the following conditions:
16 *
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
19 *
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 * THE SOFTWARE.
27 */
28
29 #include "qemu/osdep.h"
30 #include <termios.h>
31 #include <termios.h>
32
33 #include <glib/gprintf.h>
34
35 #include "sysemu/sysemu.h"
36 #include "trace.h"
37 #include "qapi/error.h"
38 #include "qemu/sockets.h"
39 #include <libgen.h>
40 #include <sys/signal.h>
41 #include "qemu/cutils.h"
42
43 #ifdef CONFIG_LINUX
44 #include <sys/syscall.h>
45 #endif
46
47 #ifdef __FreeBSD__
48 #include <sys/sysctl.h>
49 #endif
50
51 #include <qemu/mmap-alloc.h>
52
53 int qemu_get_thread_id(void)
54 {
55 #if defined(__linux__)
56 return syscall(SYS_gettid);
57 #else
58 return getpid();
59 #endif
60 }
61
62 int qemu_daemon(int nochdir, int noclose)
63 {
64 return daemon(nochdir, noclose);
65 }
66
67 void *qemu_oom_check(void *ptr)
68 {
69 if (ptr == NULL) {
70 fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
71 abort();
72 }
73 return ptr;
74 }
75
76 void *qemu_try_memalign(size_t alignment, size_t size)
77 {
78 void *ptr;
79
80 if (alignment < sizeof(void*)) {
81 alignment = sizeof(void*);
82 }
83
84 #if defined(_POSIX_C_SOURCE) && !defined(__sun__)
85 int ret;
86 ret = posix_memalign(&ptr, alignment, size);
87 if (ret != 0) {
88 errno = ret;
89 ptr = NULL;
90 }
91 #elif defined(CONFIG_BSD)
92 ptr = valloc(size);
93 #else
94 ptr = memalign(alignment, size);
95 #endif
96 trace_qemu_memalign(alignment, size, ptr);
97 return ptr;
98 }
99
100 void *qemu_memalign(size_t alignment, size_t size)
101 {
102 return qemu_oom_check(qemu_try_memalign(alignment, size));
103 }
104
105 /* alloc shared memory pages */
106 void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
107 {
108 size_t align = QEMU_VMALLOC_ALIGN;
109 void *ptr = qemu_ram_mmap(-1, size, align, false);
110
111 if (ptr == MAP_FAILED) {
112 return NULL;
113 }
114
115 if (alignment) {
116 *alignment = align;
117 }
118
119 trace_qemu_anon_ram_alloc(size, ptr);
120 return ptr;
121 }
122
123 void qemu_vfree(void *ptr)
124 {
125 trace_qemu_vfree(ptr);
126 free(ptr);
127 }
128
129 void qemu_anon_ram_free(void *ptr, size_t size)
130 {
131 trace_qemu_anon_ram_free(ptr, size);
132 qemu_ram_munmap(ptr, size);
133 }
134
135 void qemu_set_block(int fd)
136 {
137 int f;
138 f = fcntl(fd, F_GETFL);
139 fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
140 }
141
142 void qemu_set_nonblock(int fd)
143 {
144 int f;
145 f = fcntl(fd, F_GETFL);
146 fcntl(fd, F_SETFL, f | O_NONBLOCK);
147 }
148
149 int socket_set_fast_reuse(int fd)
150 {
151 int val = 1, ret;
152
153 ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
154 (const char *)&val, sizeof(val));
155
156 assert(ret == 0);
157
158 return ret;
159 }
160
161 void qemu_set_cloexec(int fd)
162 {
163 int f;
164 f = fcntl(fd, F_GETFD);
165 fcntl(fd, F_SETFD, f | FD_CLOEXEC);
166 }
167
168 /*
169 * Creates a pipe with FD_CLOEXEC set on both file descriptors
170 */
171 int qemu_pipe(int pipefd[2])
172 {
173 int ret;
174
175 #ifdef CONFIG_PIPE2
176 ret = pipe2(pipefd, O_CLOEXEC);
177 if (ret != -1 || errno != ENOSYS) {
178 return ret;
179 }
180 #endif
181 ret = pipe(pipefd);
182 if (ret == 0) {
183 qemu_set_cloexec(pipefd[0]);
184 qemu_set_cloexec(pipefd[1]);
185 }
186
187 return ret;
188 }
189
190 int qemu_utimens(const char *path, const struct timespec *times)
191 {
192 struct timeval tv[2], tv_now;
193 struct stat st;
194 int i;
195 #ifdef CONFIG_UTIMENSAT
196 int ret;
197
198 ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
199 if (ret != -1 || errno != ENOSYS) {
200 return ret;
201 }
202 #endif
203 /* Fallback: use utimes() instead of utimensat() */
204
205 /* happy if special cases */
206 if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
207 return 0;
208 }
209 if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
210 return utimes(path, NULL);
211 }
212
213 /* prepare for hard cases */
214 if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
215 gettimeofday(&tv_now, NULL);
216 }
217 if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
218 stat(path, &st);
219 }
220
221 for (i = 0; i < 2; i++) {
222 if (times[i].tv_nsec == UTIME_NOW) {
223 tv[i].tv_sec = tv_now.tv_sec;
224 tv[i].tv_usec = tv_now.tv_usec;
225 } else if (times[i].tv_nsec == UTIME_OMIT) {
226 tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
227 tv[i].tv_usec = 0;
228 } else {
229 tv[i].tv_sec = times[i].tv_sec;
230 tv[i].tv_usec = times[i].tv_nsec / 1000;
231 }
232 }
233
234 return utimes(path, &tv[0]);
235 }
236
237 char *
238 qemu_get_local_state_pathname(const char *relative_pathname)
239 {
240 return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,
241 relative_pathname);
242 }
243
244 void qemu_set_tty_echo(int fd, bool echo)
245 {
246 struct termios tty;
247
248 tcgetattr(fd, &tty);
249
250 if (echo) {
251 tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN;
252 } else {
253 tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
254 }
255
256 tcsetattr(fd, TCSANOW, &tty);
257 }
258
259 static char exec_dir[PATH_MAX];
260
261 void qemu_init_exec_dir(const char *argv0)
262 {
263 char *dir;
264 char *p = NULL;
265 char buf[PATH_MAX];
266
267 assert(!exec_dir[0]);
268
269 #if defined(__linux__)
270 {
271 int len;
272 len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
273 if (len > 0) {
274 buf[len] = 0;
275 p = buf;
276 }
277 }
278 #elif defined(__FreeBSD__)
279 {
280 static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
281 size_t len = sizeof(buf) - 1;
282
283 *buf = '\0';
284 if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
285 *buf) {
286 buf[sizeof(buf) - 1] = '\0';
287 p = buf;
288 }
289 }
290 #endif
291 /* If we don't have any way of figuring out the actual executable
292 location then try argv[0]. */
293 if (!p) {
294 if (!argv0) {
295 return;
296 }
297 p = realpath(argv0, buf);
298 if (!p) {
299 return;
300 }
301 }
302 dir = dirname(p);
303
304 pstrcpy(exec_dir, sizeof(exec_dir), dir);
305 }
306
307 char *qemu_get_exec_dir(void)
308 {
309 return g_strdup(exec_dir);
310 }
311
312 static sigjmp_buf sigjump;
313
314 static void sigbus_handler(int signal)
315 {
316 siglongjmp(sigjump, 1);
317 }
318
319 void os_mem_prealloc(int fd, char *area, size_t memory)
320 {
321 int ret;
322 struct sigaction act, oldact;
323 sigset_t set, oldset;
324
325 memset(&act, 0, sizeof(act));
326 act.sa_handler = &sigbus_handler;
327 act.sa_flags = 0;
328
329 ret = sigaction(SIGBUS, &act, &oldact);
330 if (ret) {
331 perror("os_mem_prealloc: failed to install signal handler");
332 exit(1);
333 }
334
335 /* unblock SIGBUS */
336 sigemptyset(&set);
337 sigaddset(&set, SIGBUS);
338 pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
339
340 if (sigsetjmp(sigjump, 1)) {
341 fprintf(stderr, "os_mem_prealloc: Insufficient free host memory "
342 "pages available to allocate guest RAM\n");
343 exit(1);
344 } else {
345 int i;
346 size_t hpagesize = qemu_fd_getpagesize(fd);
347 size_t numpages = DIV_ROUND_UP(memory, hpagesize);
348
349 /* MAP_POPULATE silently ignores failures */
350 for (i = 0; i < numpages; i++) {
351 memset(area + (hpagesize * i), 0, 1);
352 }
353
354 ret = sigaction(SIGBUS, &oldact, NULL);
355 if (ret) {
356 perror("os_mem_prealloc: failed to reinstall signal handler");
357 exit(1);
358 }
359
360 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
361 }
362 }
363
364
365 static struct termios oldtty;
366
367 static void term_exit(void)
368 {
369 tcsetattr(0, TCSANOW, &oldtty);
370 }
371
372 static void term_init(void)
373 {
374 struct termios tty;
375
376 tcgetattr(0, &tty);
377 oldtty = tty;
378
379 tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
380 |INLCR|IGNCR|ICRNL|IXON);
381 tty.c_oflag |= OPOST;
382 tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
383 tty.c_cflag &= ~(CSIZE|PARENB);
384 tty.c_cflag |= CS8;
385 tty.c_cc[VMIN] = 1;
386 tty.c_cc[VTIME] = 0;
387
388 tcsetattr(0, TCSANOW, &tty);
389
390 atexit(term_exit);
391 }
392
393 int qemu_read_password(char *buf, int buf_size)
394 {
395 uint8_t ch;
396 int i, ret;
397
398 printf("password: ");
399 fflush(stdout);
400 term_init();
401 i = 0;
402 for (;;) {
403 ret = read(0, &ch, 1);
404 if (ret == -1) {
405 if (errno == EAGAIN || errno == EINTR) {
406 continue;
407 } else {
408 break;
409 }
410 } else if (ret == 0) {
411 ret = -1;
412 break;
413 } else {
414 if (ch == '\r' ||
415 ch == '\n') {
416 ret = 0;
417 break;
418 }
419 if (i < (buf_size - 1)) {
420 buf[i++] = ch;
421 }
422 }
423 }
424 term_exit();
425 buf[i] = '\0';
426 printf("\n");
427 return ret;
428 }
429
430
431 pid_t qemu_fork(Error **errp)
432 {
433 sigset_t oldmask, newmask;
434 struct sigaction sig_action;
435 int saved_errno;
436 pid_t pid;
437
438 /*
439 * Need to block signals now, so that child process can safely
440 * kill off caller's signal handlers without a race.
441 */
442 sigfillset(&newmask);
443 if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
444 error_setg_errno(errp, errno,
445 "cannot block signals");
446 return -1;
447 }
448
449 pid = fork();
450 saved_errno = errno;
451
452 if (pid < 0) {
453 /* attempt to restore signal mask, but ignore failure, to
454 * avoid obscuring the fork failure */
455 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
456 error_setg_errno(errp, saved_errno,
457 "cannot fork child process");
458 errno = saved_errno;
459 return -1;
460 } else if (pid) {
461 /* parent process */
462
463 /* Restore our original signal mask now that the child is
464 * safely running. Only documented failures are EFAULT (not
465 * possible, since we are using just-grabbed mask) or EINVAL
466 * (not possible, since we are using correct arguments). */
467 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
468 } else {
469 /* child process */
470 size_t i;
471
472 /* Clear out all signal handlers from parent so nothing
473 * unexpected can happen in our child once we unblock
474 * signals */
475 sig_action.sa_handler = SIG_DFL;
476 sig_action.sa_flags = 0;
477 sigemptyset(&sig_action.sa_mask);
478
479 for (i = 1; i < NSIG; i++) {
480 /* Only possible errors are EFAULT or EINVAL The former
481 * won't happen, the latter we expect, so no need to check
482 * return value */
483 (void)sigaction(i, &sig_action, NULL);
484 }
485
486 /* Unmask all signals in child, since we've no idea what the
487 * caller's done with their signal mask and don't want to
488 * propagate that to children */
489 sigemptyset(&newmask);
490 if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
491 Error *local_err = NULL;
492 error_setg_errno(&local_err, errno,
493 "cannot unblock signals");
494 error_report_err(local_err);
495 _exit(1);
496 }
497 }
498 return pid;
499 }