util: refactor qemu_open_old to split off variadic args handling
[qemu.git] / util / osdep.c
1 /*
2 * QEMU low level functions
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #include "qemu/osdep.h"
25
26 /* Needed early for CONFIG_BSD etc. */
27
28 #ifdef CONFIG_SOLARIS
29 #include <sys/statvfs.h>
30 /* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
31 discussion about Solaris header problems */
32 extern int madvise(char *, size_t, int);
33 #endif
34
35 #include "qemu-common.h"
36 #include "qemu/cutils.h"
37 #include "qemu/sockets.h"
38 #include "qemu/error-report.h"
39 #include "monitor/monitor.h"
40
41 static bool fips_enabled = false;
42
43 static const char *hw_version = QEMU_HW_VERSION;
44
45 int socket_set_cork(int fd, int v)
46 {
47 #if defined(SOL_TCP) && defined(TCP_CORK)
48 return qemu_setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
49 #else
50 return 0;
51 #endif
52 }
53
54 int socket_set_nodelay(int fd)
55 {
56 int v = 1;
57 return qemu_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
58 }
59
60 int qemu_madvise(void *addr, size_t len, int advice)
61 {
62 if (advice == QEMU_MADV_INVALID) {
63 errno = EINVAL;
64 return -1;
65 }
66 #if defined(CONFIG_MADVISE)
67 return madvise(addr, len, advice);
68 #elif defined(CONFIG_POSIX_MADVISE)
69 return posix_madvise(addr, len, advice);
70 #else
71 errno = EINVAL;
72 return -1;
73 #endif
74 }
75
76 static int qemu_mprotect__osdep(void *addr, size_t size, int prot)
77 {
78 g_assert(!((uintptr_t)addr & ~qemu_real_host_page_mask));
79 g_assert(!(size & ~qemu_real_host_page_mask));
80
81 #ifdef _WIN32
82 DWORD old_protect;
83
84 if (!VirtualProtect(addr, size, prot, &old_protect)) {
85 g_autofree gchar *emsg = g_win32_error_message(GetLastError());
86 error_report("%s: VirtualProtect failed: %s", __func__, emsg);
87 return -1;
88 }
89 return 0;
90 #else
91 if (mprotect(addr, size, prot)) {
92 error_report("%s: mprotect failed: %s", __func__, strerror(errno));
93 return -1;
94 }
95 return 0;
96 #endif
97 }
98
99 int qemu_mprotect_rwx(void *addr, size_t size)
100 {
101 #ifdef _WIN32
102 return qemu_mprotect__osdep(addr, size, PAGE_EXECUTE_READWRITE);
103 #else
104 return qemu_mprotect__osdep(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC);
105 #endif
106 }
107
108 int qemu_mprotect_none(void *addr, size_t size)
109 {
110 #ifdef _WIN32
111 return qemu_mprotect__osdep(addr, size, PAGE_NOACCESS);
112 #else
113 return qemu_mprotect__osdep(addr, size, PROT_NONE);
114 #endif
115 }
116
117 #ifndef _WIN32
118
119 static int fcntl_op_setlk = -1;
120 static int fcntl_op_getlk = -1;
121
122 /*
123 * Dups an fd and sets the flags
124 */
125 int qemu_dup_flags(int fd, int flags)
126 {
127 int ret;
128 int serrno;
129 int dup_flags;
130
131 ret = qemu_dup(fd);
132 if (ret == -1) {
133 goto fail;
134 }
135
136 dup_flags = fcntl(ret, F_GETFL);
137 if (dup_flags == -1) {
138 goto fail;
139 }
140
141 if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
142 errno = EINVAL;
143 goto fail;
144 }
145
146 /* Set/unset flags that we can with fcntl */
147 if (fcntl(ret, F_SETFL, flags) == -1) {
148 goto fail;
149 }
150
151 /* Truncate the file in the cases that open() would truncate it */
152 if (flags & O_TRUNC ||
153 ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) {
154 if (ftruncate(ret, 0) == -1) {
155 goto fail;
156 }
157 }
158
159 return ret;
160
161 fail:
162 serrno = errno;
163 if (ret != -1) {
164 close(ret);
165 }
166 errno = serrno;
167 return -1;
168 }
169
170 int qemu_dup(int fd)
171 {
172 int ret;
173 #ifdef F_DUPFD_CLOEXEC
174 ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
175 #else
176 ret = dup(fd);
177 if (ret != -1) {
178 qemu_set_cloexec(ret);
179 }
180 #endif
181 return ret;
182 }
183
184 static int qemu_parse_fdset(const char *param)
185 {
186 return qemu_parse_fd(param);
187 }
188
189 static void qemu_probe_lock_ops(void)
190 {
191 if (fcntl_op_setlk == -1) {
192 #ifdef F_OFD_SETLK
193 int fd;
194 int ret;
195 struct flock fl = {
196 .l_whence = SEEK_SET,
197 .l_start = 0,
198 .l_len = 0,
199 .l_type = F_WRLCK,
200 };
201
202 fd = open("/dev/null", O_RDWR);
203 if (fd < 0) {
204 fprintf(stderr,
205 "Failed to open /dev/null for OFD lock probing: %s\n",
206 strerror(errno));
207 fcntl_op_setlk = F_SETLK;
208 fcntl_op_getlk = F_GETLK;
209 return;
210 }
211 ret = fcntl(fd, F_OFD_GETLK, &fl);
212 close(fd);
213 if (!ret) {
214 fcntl_op_setlk = F_OFD_SETLK;
215 fcntl_op_getlk = F_OFD_GETLK;
216 } else {
217 fcntl_op_setlk = F_SETLK;
218 fcntl_op_getlk = F_GETLK;
219 }
220 #else
221 fcntl_op_setlk = F_SETLK;
222 fcntl_op_getlk = F_GETLK;
223 #endif
224 }
225 }
226
227 bool qemu_has_ofd_lock(void)
228 {
229 qemu_probe_lock_ops();
230 #ifdef F_OFD_SETLK
231 return fcntl_op_setlk == F_OFD_SETLK;
232 #else
233 return false;
234 #endif
235 }
236
237 static int qemu_lock_fcntl(int fd, int64_t start, int64_t len, int fl_type)
238 {
239 int ret;
240 struct flock fl = {
241 .l_whence = SEEK_SET,
242 .l_start = start,
243 .l_len = len,
244 .l_type = fl_type,
245 };
246 qemu_probe_lock_ops();
247 do {
248 ret = fcntl(fd, fcntl_op_setlk, &fl);
249 } while (ret == -1 && errno == EINTR);
250 return ret == -1 ? -errno : 0;
251 }
252
253 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive)
254 {
255 return qemu_lock_fcntl(fd, start, len, exclusive ? F_WRLCK : F_RDLCK);
256 }
257
258 int qemu_unlock_fd(int fd, int64_t start, int64_t len)
259 {
260 return qemu_lock_fcntl(fd, start, len, F_UNLCK);
261 }
262
263 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive)
264 {
265 int ret;
266 struct flock fl = {
267 .l_whence = SEEK_SET,
268 .l_start = start,
269 .l_len = len,
270 .l_type = exclusive ? F_WRLCK : F_RDLCK,
271 };
272 qemu_probe_lock_ops();
273 ret = fcntl(fd, fcntl_op_getlk, &fl);
274 if (ret == -1) {
275 return -errno;
276 } else {
277 return fl.l_type == F_UNLCK ? 0 : -EAGAIN;
278 }
279 }
280 #endif
281
282 static int qemu_open_cloexec(const char *name, int flags, mode_t mode)
283 {
284 int ret;
285 #ifdef O_CLOEXEC
286 ret = open(name, flags | O_CLOEXEC, mode);
287 #else
288 ret = open(name, flags, mode);
289 if (ret >= 0) {
290 qemu_set_cloexec(ret);
291 }
292 #endif
293 return ret;
294 }
295
296 /*
297 * Opens a file with FD_CLOEXEC set
298 */
299 static int
300 qemu_open_internal(const char *name, int flags, mode_t mode)
301 {
302 int ret;
303
304 #ifndef _WIN32
305 const char *fdset_id_str;
306
307 /* Attempt dup of fd from fd set */
308 if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
309 int64_t fdset_id;
310 int dupfd;
311
312 fdset_id = qemu_parse_fdset(fdset_id_str);
313 if (fdset_id == -1) {
314 errno = EINVAL;
315 return -1;
316 }
317
318 dupfd = monitor_fdset_dup_fd_add(fdset_id, flags);
319 if (dupfd == -1) {
320 return -1;
321 }
322
323 return dupfd;
324 }
325 #endif
326
327 ret = qemu_open_cloexec(name, flags, mode);
328
329 return ret;
330 }
331
332
333 int qemu_open_old(const char *name, int flags, ...)
334 {
335 va_list ap;
336 mode_t mode = 0;
337 int ret;
338
339 va_start(ap, flags);
340 if (flags & O_CREAT) {
341 mode = va_arg(ap, int);
342 }
343 va_end(ap);
344
345 ret = qemu_open_internal(name, flags, mode);
346
347 #ifdef O_DIRECT
348 if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
349 error_report("file system may not support O_DIRECT");
350 errno = EINVAL; /* in case it was clobbered */
351 }
352 #endif /* O_DIRECT */
353
354 return ret;
355 }
356
357 int qemu_close(int fd)
358 {
359 int64_t fdset_id;
360
361 /* Close fd that was dup'd from an fdset */
362 fdset_id = monitor_fdset_dup_fd_find(fd);
363 if (fdset_id != -1) {
364 int ret;
365
366 ret = close(fd);
367 if (ret == 0) {
368 monitor_fdset_dup_fd_remove(fd);
369 }
370
371 return ret;
372 }
373
374 return close(fd);
375 }
376
377 /*
378 * Delete a file from the filesystem, unless the filename is /dev/fdset/...
379 *
380 * Returns: On success, zero is returned. On error, -1 is returned,
381 * and errno is set appropriately.
382 */
383 int qemu_unlink(const char *name)
384 {
385 if (g_str_has_prefix(name, "/dev/fdset/")) {
386 return 0;
387 }
388
389 return unlink(name);
390 }
391
392 /*
393 * A variant of write(2) which handles partial write.
394 *
395 * Return the number of bytes transferred.
396 * Set errno if fewer than `count' bytes are written.
397 *
398 * This function don't work with non-blocking fd's.
399 * Any of the possibilities with non-bloking fd's is bad:
400 * - return a short write (then name is wrong)
401 * - busy wait adding (errno == EAGAIN) to the loop
402 */
403 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
404 {
405 ssize_t ret = 0;
406 ssize_t total = 0;
407
408 while (count) {
409 ret = write(fd, buf, count);
410 if (ret < 0) {
411 if (errno == EINTR)
412 continue;
413 break;
414 }
415
416 count -= ret;
417 buf += ret;
418 total += ret;
419 }
420
421 return total;
422 }
423
424 /*
425 * Opens a socket with FD_CLOEXEC set
426 */
427 int qemu_socket(int domain, int type, int protocol)
428 {
429 int ret;
430
431 #ifdef SOCK_CLOEXEC
432 ret = socket(domain, type | SOCK_CLOEXEC, protocol);
433 if (ret != -1 || errno != EINVAL) {
434 return ret;
435 }
436 #endif
437 ret = socket(domain, type, protocol);
438 if (ret >= 0) {
439 qemu_set_cloexec(ret);
440 }
441
442 return ret;
443 }
444
445 /*
446 * Accept a connection and set FD_CLOEXEC
447 */
448 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
449 {
450 int ret;
451
452 #ifdef CONFIG_ACCEPT4
453 ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
454 if (ret != -1 || errno != ENOSYS) {
455 return ret;
456 }
457 #endif
458 ret = accept(s, addr, addrlen);
459 if (ret >= 0) {
460 qemu_set_cloexec(ret);
461 }
462
463 return ret;
464 }
465
466 void qemu_set_hw_version(const char *version)
467 {
468 hw_version = version;
469 }
470
471 const char *qemu_hw_version(void)
472 {
473 return hw_version;
474 }
475
476 void fips_set_state(bool requested)
477 {
478 #ifdef __linux__
479 if (requested) {
480 FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
481 if (fds != NULL) {
482 fips_enabled = (fgetc(fds) == '1');
483 fclose(fds);
484 }
485 }
486 #else
487 fips_enabled = false;
488 #endif /* __linux__ */
489
490 #ifdef _FIPS_DEBUG
491 fprintf(stderr, "FIPS mode %s (requested %s)\n",
492 (fips_enabled ? "enabled" : "disabled"),
493 (requested ? "enabled" : "disabled"));
494 #endif
495 }
496
497 bool fips_get_state(void)
498 {
499 return fips_enabled;
500 }
501
502 #ifdef _WIN32
503 static void socket_cleanup(void)
504 {
505 WSACleanup();
506 }
507 #endif
508
509 int socket_init(void)
510 {
511 #ifdef _WIN32
512 WSADATA Data;
513 int ret, err;
514
515 ret = WSAStartup(MAKEWORD(2, 2), &Data);
516 if (ret != 0) {
517 err = WSAGetLastError();
518 fprintf(stderr, "WSAStartup: %d\n", err);
519 return -1;
520 }
521 atexit(socket_cleanup);
522 #endif
523 return 0;
524 }
525
526
527 #ifndef CONFIG_IOVEC
528 /* helper function for iov_send_recv() */
529 static ssize_t
530 readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
531 {
532 unsigned i = 0;
533 ssize_t ret = 0;
534 while (i < iov_cnt) {
535 ssize_t r = do_write
536 ? write(fd, iov[i].iov_base, iov[i].iov_len)
537 : read(fd, iov[i].iov_base, iov[i].iov_len);
538 if (r > 0) {
539 ret += r;
540 } else if (!r) {
541 break;
542 } else if (errno == EINTR) {
543 continue;
544 } else {
545 /* else it is some "other" error,
546 * only return if there was no data processed. */
547 if (ret == 0) {
548 ret = -1;
549 }
550 break;
551 }
552 i++;
553 }
554 return ret;
555 }
556
557 ssize_t
558 readv(int fd, const struct iovec *iov, int iov_cnt)
559 {
560 return readv_writev(fd, iov, iov_cnt, false);
561 }
562
563 ssize_t
564 writev(int fd, const struct iovec *iov, int iov_cnt)
565 {
566 return readv_writev(fd, iov, iov_cnt, true);
567 }
568 #endif