slirp: Generalizing and neutralizing ARP code
[qemu/ar7.git] / util / oslib-posix.c
blobd25f6715c75c042a71014ede79460d94f720aaae
1 /*
2 * os-posix-lib.c
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2010 Red Hat, Inc.
7 * QEMU library functions on POSIX which are shared between QEMU and
8 * the QEMU tools.
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:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
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.
29 /* The following block of code temporarily renames the daemon() function so the
30 compiler does not see the warning associated with it in stdlib.h on OSX */
31 #ifdef __APPLE__
32 #define daemon qemu_fake_daemon_function
33 #include <stdlib.h>
34 #undef daemon
35 extern int daemon(int, int);
36 #endif
38 #if defined(__linux__) && (defined(__x86_64__) || defined(__arm__))
39 /* Use 2 MiB alignment so transparent hugepages can be used by KVM.
40 Valgrind does not support alignments larger than 1 MiB,
41 therefore we need special code which handles running on Valgrind. */
42 # define QEMU_VMALLOC_ALIGN (512 * 4096)
43 #elif defined(__linux__) && defined(__s390x__)
44 /* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
45 # define QEMU_VMALLOC_ALIGN (256 * 4096)
46 #else
47 # define QEMU_VMALLOC_ALIGN getpagesize()
48 #endif
50 #include <termios.h>
51 #include <unistd.h>
52 #include <termios.h>
54 #include <glib/gprintf.h>
56 #include "config-host.h"
57 #include "sysemu/sysemu.h"
58 #include "trace.h"
59 #include "qemu/sockets.h"
60 #include <sys/mman.h>
61 #include <libgen.h>
62 #include <setjmp.h>
63 #include <sys/signal.h>
65 #ifdef CONFIG_LINUX
66 #include <sys/syscall.h>
67 #endif
69 #ifdef __FreeBSD__
70 #include <sys/sysctl.h>
71 #endif
73 #include <qemu/mmap-alloc.h>
75 int qemu_get_thread_id(void)
77 #if defined(__linux__)
78 return syscall(SYS_gettid);
79 #else
80 return getpid();
81 #endif
84 int qemu_daemon(int nochdir, int noclose)
86 return daemon(nochdir, noclose);
89 void *qemu_oom_check(void *ptr)
91 if (ptr == NULL) {
92 fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
93 abort();
95 return ptr;
98 void *qemu_try_memalign(size_t alignment, size_t size)
100 void *ptr;
102 if (alignment < sizeof(void*)) {
103 alignment = sizeof(void*);
106 #if defined(_POSIX_C_SOURCE) && !defined(__sun__)
107 int ret;
108 ret = posix_memalign(&ptr, alignment, size);
109 if (ret != 0) {
110 errno = ret;
111 ptr = NULL;
113 #elif defined(CONFIG_BSD)
114 ptr = valloc(size);
115 #else
116 ptr = memalign(alignment, size);
117 #endif
118 trace_qemu_memalign(alignment, size, ptr);
119 return ptr;
122 void *qemu_memalign(size_t alignment, size_t size)
124 return qemu_oom_check(qemu_try_memalign(alignment, size));
127 /* alloc shared memory pages */
128 void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
130 size_t align = QEMU_VMALLOC_ALIGN;
131 void *ptr = qemu_ram_mmap(-1, size, align, false);
133 if (ptr == MAP_FAILED) {
134 return NULL;
137 if (alignment) {
138 *alignment = align;
141 trace_qemu_anon_ram_alloc(size, ptr);
142 return ptr;
145 void qemu_vfree(void *ptr)
147 trace_qemu_vfree(ptr);
148 free(ptr);
151 void qemu_anon_ram_free(void *ptr, size_t size)
153 trace_qemu_anon_ram_free(ptr, size);
154 qemu_ram_munmap(ptr, size);
157 void qemu_set_block(int fd)
159 int f;
160 f = fcntl(fd, F_GETFL);
161 fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
164 void qemu_set_nonblock(int fd)
166 int f;
167 f = fcntl(fd, F_GETFL);
168 fcntl(fd, F_SETFL, f | O_NONBLOCK);
171 int socket_set_fast_reuse(int fd)
173 int val = 1, ret;
175 ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
176 (const char *)&val, sizeof(val));
178 assert(ret == 0);
180 return ret;
183 void qemu_set_cloexec(int fd)
185 int f;
186 f = fcntl(fd, F_GETFD);
187 fcntl(fd, F_SETFD, f | FD_CLOEXEC);
191 * Creates a pipe with FD_CLOEXEC set on both file descriptors
193 int qemu_pipe(int pipefd[2])
195 int ret;
197 #ifdef CONFIG_PIPE2
198 ret = pipe2(pipefd, O_CLOEXEC);
199 if (ret != -1 || errno != ENOSYS) {
200 return ret;
202 #endif
203 ret = pipe(pipefd);
204 if (ret == 0) {
205 qemu_set_cloexec(pipefd[0]);
206 qemu_set_cloexec(pipefd[1]);
209 return ret;
212 int qemu_utimens(const char *path, const struct timespec *times)
214 struct timeval tv[2], tv_now;
215 struct stat st;
216 int i;
217 #ifdef CONFIG_UTIMENSAT
218 int ret;
220 ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
221 if (ret != -1 || errno != ENOSYS) {
222 return ret;
224 #endif
225 /* Fallback: use utimes() instead of utimensat() */
227 /* happy if special cases */
228 if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
229 return 0;
231 if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
232 return utimes(path, NULL);
235 /* prepare for hard cases */
236 if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
237 gettimeofday(&tv_now, NULL);
239 if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
240 stat(path, &st);
243 for (i = 0; i < 2; i++) {
244 if (times[i].tv_nsec == UTIME_NOW) {
245 tv[i].tv_sec = tv_now.tv_sec;
246 tv[i].tv_usec = tv_now.tv_usec;
247 } else if (times[i].tv_nsec == UTIME_OMIT) {
248 tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
249 tv[i].tv_usec = 0;
250 } else {
251 tv[i].tv_sec = times[i].tv_sec;
252 tv[i].tv_usec = times[i].tv_nsec / 1000;
256 return utimes(path, &tv[0]);
259 char *
260 qemu_get_local_state_pathname(const char *relative_pathname)
262 return g_strdup_printf("%s/%s", CONFIG_QEMU_LOCALSTATEDIR,
263 relative_pathname);
266 void qemu_set_tty_echo(int fd, bool echo)
268 struct termios tty;
270 tcgetattr(fd, &tty);
272 if (echo) {
273 tty.c_lflag |= ECHO | ECHONL | ICANON | IEXTEN;
274 } else {
275 tty.c_lflag &= ~(ECHO | ECHONL | ICANON | IEXTEN);
278 tcsetattr(fd, TCSANOW, &tty);
281 static char exec_dir[PATH_MAX];
283 void qemu_init_exec_dir(const char *argv0)
285 char *dir;
286 char *p = NULL;
287 char buf[PATH_MAX];
289 assert(!exec_dir[0]);
291 #if defined(__linux__)
293 int len;
294 len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
295 if (len > 0) {
296 buf[len] = 0;
297 p = buf;
300 #elif defined(__FreeBSD__)
302 static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
303 size_t len = sizeof(buf) - 1;
305 *buf = '\0';
306 if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
307 *buf) {
308 buf[sizeof(buf) - 1] = '\0';
309 p = buf;
312 #endif
313 /* If we don't have any way of figuring out the actual executable
314 location then try argv[0]. */
315 if (!p) {
316 if (!argv0) {
317 return;
319 p = realpath(argv0, buf);
320 if (!p) {
321 return;
324 dir = dirname(p);
326 pstrcpy(exec_dir, sizeof(exec_dir), dir);
329 char *qemu_get_exec_dir(void)
331 return g_strdup(exec_dir);
334 static sigjmp_buf sigjump;
336 static void sigbus_handler(int signal)
338 siglongjmp(sigjump, 1);
341 void os_mem_prealloc(int fd, char *area, size_t memory)
343 int ret;
344 struct sigaction act, oldact;
345 sigset_t set, oldset;
347 memset(&act, 0, sizeof(act));
348 act.sa_handler = &sigbus_handler;
349 act.sa_flags = 0;
351 ret = sigaction(SIGBUS, &act, &oldact);
352 if (ret) {
353 perror("os_mem_prealloc: failed to install signal handler");
354 exit(1);
357 /* unblock SIGBUS */
358 sigemptyset(&set);
359 sigaddset(&set, SIGBUS);
360 pthread_sigmask(SIG_UNBLOCK, &set, &oldset);
362 if (sigsetjmp(sigjump, 1)) {
363 fprintf(stderr, "os_mem_prealloc: Insufficient free host memory "
364 "pages available to allocate guest RAM\n");
365 exit(1);
366 } else {
367 int i;
368 size_t hpagesize = qemu_fd_getpagesize(fd);
369 size_t numpages = DIV_ROUND_UP(memory, hpagesize);
371 /* MAP_POPULATE silently ignores failures */
372 for (i = 0; i < numpages; i++) {
373 memset(area + (hpagesize * i), 0, 1);
376 ret = sigaction(SIGBUS, &oldact, NULL);
377 if (ret) {
378 perror("os_mem_prealloc: failed to reinstall signal handler");
379 exit(1);
382 pthread_sigmask(SIG_SETMASK, &oldset, NULL);
387 static struct termios oldtty;
389 static void term_exit(void)
391 tcsetattr(0, TCSANOW, &oldtty);
394 static void term_init(void)
396 struct termios tty;
398 tcgetattr(0, &tty);
399 oldtty = tty;
401 tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
402 |INLCR|IGNCR|ICRNL|IXON);
403 tty.c_oflag |= OPOST;
404 tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
405 tty.c_cflag &= ~(CSIZE|PARENB);
406 tty.c_cflag |= CS8;
407 tty.c_cc[VMIN] = 1;
408 tty.c_cc[VTIME] = 0;
410 tcsetattr(0, TCSANOW, &tty);
412 atexit(term_exit);
415 int qemu_read_password(char *buf, int buf_size)
417 uint8_t ch;
418 int i, ret;
420 printf("password: ");
421 fflush(stdout);
422 term_init();
423 i = 0;
424 for (;;) {
425 ret = read(0, &ch, 1);
426 if (ret == -1) {
427 if (errno == EAGAIN || errno == EINTR) {
428 continue;
429 } else {
430 break;
432 } else if (ret == 0) {
433 ret = -1;
434 break;
435 } else {
436 if (ch == '\r' ||
437 ch == '\n') {
438 ret = 0;
439 break;
441 if (i < (buf_size - 1)) {
442 buf[i++] = ch;
446 term_exit();
447 buf[i] = '\0';
448 printf("\n");
449 return ret;
453 pid_t qemu_fork(Error **errp)
455 sigset_t oldmask, newmask;
456 struct sigaction sig_action;
457 int saved_errno;
458 pid_t pid;
461 * Need to block signals now, so that child process can safely
462 * kill off caller's signal handlers without a race.
464 sigfillset(&newmask);
465 if (pthread_sigmask(SIG_SETMASK, &newmask, &oldmask) != 0) {
466 error_setg_errno(errp, errno,
467 "cannot block signals");
468 return -1;
471 pid = fork();
472 saved_errno = errno;
474 if (pid < 0) {
475 /* attempt to restore signal mask, but ignore failure, to
476 * avoid obscuring the fork failure */
477 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
478 error_setg_errno(errp, saved_errno,
479 "cannot fork child process");
480 errno = saved_errno;
481 return -1;
482 } else if (pid) {
483 /* parent process */
485 /* Restore our original signal mask now that the child is
486 * safely running. Only documented failures are EFAULT (not
487 * possible, since we are using just-grabbed mask) or EINVAL
488 * (not possible, since we are using correct arguments). */
489 (void)pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
490 } else {
491 /* child process */
492 size_t i;
494 /* Clear out all signal handlers from parent so nothing
495 * unexpected can happen in our child once we unblock
496 * signals */
497 sig_action.sa_handler = SIG_DFL;
498 sig_action.sa_flags = 0;
499 sigemptyset(&sig_action.sa_mask);
501 for (i = 1; i < NSIG; i++) {
502 /* Only possible errors are EFAULT or EINVAL The former
503 * won't happen, the latter we expect, so no need to check
504 * return value */
505 (void)sigaction(i, &sig_action, NULL);
508 /* Unmask all signals in child, since we've no idea what the
509 * caller's done with their signal mask and don't want to
510 * propagate that to children */
511 sigemptyset(&newmask);
512 if (pthread_sigmask(SIG_SETMASK, &newmask, NULL) != 0) {
513 Error *local_err = NULL;
514 error_setg_errno(&local_err, errno,
515 "cannot unblock signals");
516 error_report_err(local_err);
517 _exit(1);
520 return pid;