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 */
32extern 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
41static bool fips_enabled = false;
42
43static const char *hw_version = QEMU_HW_VERSION;
44
45int 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
54int socket_set_nodelay(int fd)
55{
56 int v = 1;
57 return qemu_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
58}
59
60int 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
76static 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 error_report("%s: VirtualProtect failed with error code %ld",
86 __func__, GetLastError());
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
99int 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
108int 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
119static int fcntl_op_setlk = -1;
120static int fcntl_op_getlk = -1;
121
122/*
123 * Dups an fd and sets the flags
124 */
125static 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
161fail:
162 serrno = errno;
163 if (ret != -1) {
164 close(ret);
165 }
166 errno = serrno;
167 return -1;
168}
169
170int 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
184static int qemu_parse_fdset(const char *param)
185{
186 return qemu_parse_fd(param);
187}
188
189static 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
227bool 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
237static 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
253int 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
258int qemu_unlock_fd(int fd, int64_t start, int64_t len)
259{
260 return qemu_lock_fcntl(fd, start, len, F_UNLCK);
261}
262
263int 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/*
283 * Opens a file with FD_CLOEXEC set
284 */
285int qemu_open(const char *name, int flags, ...)
286{
287 int ret;
288 int mode = 0;
289
290#ifndef _WIN32
291 const char *fdset_id_str;
292
293 /* Attempt dup of fd from fd set */
294 if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
295 int64_t fdset_id;
296 int fd, dupfd;
297
298 fdset_id = qemu_parse_fdset(fdset_id_str);
299 if (fdset_id == -1) {
300 errno = EINVAL;
301 return -1;
302 }
303
304 fd = monitor_fdset_get_fd(fdset_id, flags);
305 if (fd < 0) {
306 errno = -fd;
307 return -1;
308 }
309
310 dupfd = qemu_dup_flags(fd, flags);
311 if (dupfd == -1) {
312 return -1;
313 }
314
315 ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
316 if (ret == -1) {
317 close(dupfd);
318 errno = EINVAL;
319 return -1;
320 }
321
322 return dupfd;
323 }
324#endif
325
326 if (flags & O_CREAT) {
327 va_list ap;
328
329 va_start(ap, flags);
330 mode = va_arg(ap, int);
331 va_end(ap);
332 }
333
334#ifdef O_CLOEXEC
335 ret = open(name, flags | O_CLOEXEC, mode);
336#else
337 ret = open(name, flags, mode);
338 if (ret >= 0) {
339 qemu_set_cloexec(ret);
340 }
341#endif
342
343#ifdef O_DIRECT
344 if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
345 error_report("file system may not support O_DIRECT");
346 errno = EINVAL; /* in case it was clobbered */
347 }
348#endif /* O_DIRECT */
349
350 return ret;
351}
352
353int qemu_close(int fd)
354{
355 int64_t fdset_id;
356
357 /* Close fd that was dup'd from an fdset */
358 fdset_id = monitor_fdset_dup_fd_find(fd);
359 if (fdset_id != -1) {
360 int ret;
361
362 ret = close(fd);
363 if (ret == 0) {
364 monitor_fdset_dup_fd_remove(fd);
365 }
366
367 return ret;
368 }
369
370 return close(fd);
371}
372
373/*
374 * A variant of write(2) which handles partial write.
375 *
376 * Return the number of bytes transferred.
377 * Set errno if fewer than `count' bytes are written.
378 *
379 * This function don't work with non-blocking fd's.
380 * Any of the possibilities with non-bloking fd's is bad:
381 * - return a short write (then name is wrong)
382 * - busy wait adding (errno == EAGAIN) to the loop
383 */
384ssize_t qemu_write_full(int fd, const void *buf, size_t count)
385{
386 ssize_t ret = 0;
387 ssize_t total = 0;
388
389 while (count) {
390 ret = write(fd, buf, count);
391 if (ret < 0) {
392 if (errno == EINTR)
393 continue;
394 break;
395 }
396
397 count -= ret;
398 buf += ret;
399 total += ret;
400 }
401
402 return total;
403}
404
405/*
406 * Opens a socket with FD_CLOEXEC set
407 */
408int qemu_socket(int domain, int type, int protocol)
409{
410 int ret;
411
412#ifdef SOCK_CLOEXEC
413 ret = socket(domain, type | SOCK_CLOEXEC, protocol);
414 if (ret != -1 || errno != EINVAL) {
415 return ret;
416 }
417#endif
418 ret = socket(domain, type, protocol);
419 if (ret >= 0) {
420 qemu_set_cloexec(ret);
421 }
422
423 return ret;
424}
425
426/*
427 * Accept a connection and set FD_CLOEXEC
428 */
429int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
430{
431 int ret;
432
433#ifdef CONFIG_ACCEPT4
434 ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
435 if (ret != -1 || errno != ENOSYS) {
436 return ret;
437 }
438#endif
439 ret = accept(s, addr, addrlen);
440 if (ret >= 0) {
441 qemu_set_cloexec(ret);
442 }
443
444 return ret;
445}
446
447void qemu_set_hw_version(const char *version)
448{
449 hw_version = version;
450}
451
452const char *qemu_hw_version(void)
453{
454 return hw_version;
455}
456
457void fips_set_state(bool requested)
458{
459#ifdef __linux__
460 if (requested) {
461 FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
462 if (fds != NULL) {
463 fips_enabled = (fgetc(fds) == '1');
464 fclose(fds);
465 }
466 }
467#else
468 fips_enabled = false;
469#endif /* __linux__ */
470
471#ifdef _FIPS_DEBUG
472 fprintf(stderr, "FIPS mode %s (requested %s)\n",
473 (fips_enabled ? "enabled" : "disabled"),
474 (requested ? "enabled" : "disabled"));
475#endif
476}
477
478bool fips_get_state(void)
479{
480 return fips_enabled;
481}
482
483#ifdef _WIN32
484static void socket_cleanup(void)
485{
486 WSACleanup();
487}
488#endif
489
490int socket_init(void)
491{
492#ifdef _WIN32
493 WSADATA Data;
494 int ret, err;
495
496 ret = WSAStartup(MAKEWORD(2, 2), &Data);
497 if (ret != 0) {
498 err = WSAGetLastError();
499 fprintf(stderr, "WSAStartup: %d\n", err);
500 return -1;
501 }
502 atexit(socket_cleanup);
503#endif
504 return 0;
505}
506
507
508#ifndef CONFIG_IOVEC
509/* helper function for iov_send_recv() */
510static ssize_t
511readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
512{
513 unsigned i = 0;
514 ssize_t ret = 0;
515 while (i < iov_cnt) {
516 ssize_t r = do_write
517 ? write(fd, iov[i].iov_base, iov[i].iov_len)
518 : read(fd, iov[i].iov_base, iov[i].iov_len);
519 if (r > 0) {
520 ret += r;
521 } else if (!r) {
522 break;
523 } else if (errno == EINTR) {
524 continue;
525 } else {
526 /* else it is some "other" error,
527 * only return if there was no data processed. */
528 if (ret == 0) {
529 ret = -1;
530 }
531 break;
532 }
533 i++;
534 }
535 return ret;
536}
537
538ssize_t
539readv(int fd, const struct iovec *iov, int iov_cnt)
540{
541 return readv_writev(fd, iov, iov_cnt, false);
542}
543
544ssize_t
545writev(int fd, const struct iovec *iov, int iov_cnt)
546{
547 return readv_writev(fd, iov, iov_cnt, true);
548}
549#endif
550