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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 <stdlib.h>
25 #include <stdio.h>
26 #include <stdarg.h>
27 #include <stdbool.h>
28 #include <string.h>
29 #include <errno.h>
30 #include <unistd.h>
31 #include <fcntl.h>
32 
33 #ifndef _WIN32
34 #include <sys/socket.h>
35 #endif
36 
37 /* Needed early for CONFIG_BSD etc. */
38 #include "config-host.h"
39 
40 #if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
41 #include <sys/mman.h>
42 #endif
43 
44 #ifdef CONFIG_SOLARIS
45 #include <sys/types.h>
46 #include <sys/statvfs.h>
47 /* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
48    discussion about Solaris header problems */
49 extern int madvise(caddr_t, size_t, int);
50 #endif
51 
52 #include "qemu-common.h"
53 #include "trace.h"
54 #include "qemu/sockets.h"
55 #include "monitor/monitor.h"
56 
57 static bool fips_enabled = false;
58 
59 static const char *qemu_version = QEMU_VERSION;
60 
61 #ifndef CONFIG_ANDROID  // See android/sockets.c instead.
socket_set_cork(int fd,int v)62 int socket_set_cork(int fd, int v)
63 {
64 #if defined(SOL_TCP) && defined(TCP_CORK)
65     return qemu_setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
66 #else
67     return 0;
68 #endif
69 }
70 
socket_set_nodelay(int fd)71 int socket_set_nodelay(int fd)
72 {
73     int v = 1;
74     return qemu_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
75 }
76 #endif  // !CONFIG_ANDROID
77 
qemu_madvise(void * addr,size_t len,int advice)78 int qemu_madvise(void *addr, size_t len, int advice)
79 {
80     if (advice == QEMU_MADV_INVALID) {
81         errno = EINVAL;
82         return -1;
83     }
84 #if defined(CONFIG_MADVISE)
85     return madvise(addr, len, advice);
86 #elif defined(CONFIG_POSIX_MADVISE)
87     return posix_madvise(addr, len, advice);
88 #else
89     errno = EINVAL;
90     return -1;
91 #endif
92 }
93 
94 #ifndef CONFIG_ANDROID
95 #ifndef _WIN32
96 /*
97  * Dups an fd and sets the flags
98  */
qemu_dup_flags(int fd,int flags)99 static int qemu_dup_flags(int fd, int flags)
100 {
101     int ret;
102     int serrno;
103     int dup_flags;
104 
105 #ifdef F_DUPFD_CLOEXEC
106     ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
107 #else
108     ret = dup(fd);
109     if (ret != -1) {
110         qemu_set_cloexec(ret);
111     }
112 #endif
113     if (ret == -1) {
114         goto fail;
115     }
116 
117     dup_flags = fcntl(ret, F_GETFL);
118     if (dup_flags == -1) {
119         goto fail;
120     }
121 
122     if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
123         errno = EINVAL;
124         goto fail;
125     }
126 
127     /* Set/unset flags that we can with fcntl */
128     if (fcntl(ret, F_SETFL, flags) == -1) {
129         goto fail;
130     }
131 
132     /* Truncate the file in the cases that open() would truncate it */
133     if (flags & O_TRUNC ||
134             ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) {
135         if (ftruncate(ret, 0) == -1) {
136             goto fail;
137         }
138     }
139 
140     return ret;
141 
142 fail:
143     serrno = errno;
144     if (ret != -1) {
145         close(ret);
146     }
147     errno = serrno;
148     return -1;
149 }
150 
qemu_parse_fdset(const char * param)151 static int qemu_parse_fdset(const char *param)
152 {
153     return qemu_parse_fd(param);
154 }
155 #endif
156 #endif  // !CONFIG_ANDROID
157 
158 /*
159  * Opens a file with FD_CLOEXEC set
160  */
qemu_open(const char * name,int flags,...)161 int qemu_open(const char *name, int flags, ...)
162 {
163     int ret;
164     int mode = 0;
165 
166 #ifndef CONFIG_ANDROID
167 #ifndef _WIN32
168     const char *fdset_id_str;
169 
170     /* Attempt dup of fd from fd set */
171     if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
172         int64_t fdset_id;
173         int fd, dupfd;
174 
175         fdset_id = qemu_parse_fdset(fdset_id_str);
176         if (fdset_id == -1) {
177             errno = EINVAL;
178             return -1;
179         }
180 
181         fd = monitor_fdset_get_fd(fdset_id, flags);
182         if (fd == -1) {
183             return -1;
184         }
185 
186         dupfd = qemu_dup_flags(fd, flags);
187         if (dupfd == -1) {
188             return -1;
189         }
190 
191         ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
192         if (ret == -1) {
193             close(dupfd);
194             errno = EINVAL;
195             return -1;
196         }
197         return dupfd;
198     }
199 #endif
200 #endif  // !CONFIG_ANDROID
201 
202     if (flags & O_CREAT) {
203         va_list ap;
204 
205         va_start(ap, flags);
206         mode = va_arg(ap, int);
207         va_end(ap);
208     }
209 
210 #ifdef O_CLOEXEC
211     ret = open(name, flags | O_CLOEXEC, mode);
212 #else
213     ret = open(name, flags, mode);
214     if (ret >= 0) {
215         qemu_set_cloexec(ret);
216     }
217 #endif
218 
219 #ifdef O_DIRECT
220     if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
221         error_report("file system may not support O_DIRECT");
222         errno = EINVAL; /* in case it was clobbered */
223     }
224 #endif /* O_DIRECT */
225 
226     return ret;
227 }
228 
qemu_close(int fd)229 int qemu_close(int fd)
230 {
231 #ifndef CONFIG_ANDROID
232     int64_t fdset_id;
233 
234     /* Close fd that was dup'd from an fdset */
235     fdset_id = monitor_fdset_dup_fd_find(fd);
236     if (fdset_id != -1) {
237         int ret;
238 
239         ret = close(fd);
240         if (ret == 0) {
241             monitor_fdset_dup_fd_remove(fd);
242         }
243 
244         return ret;
245     }
246 #endif
247     return close(fd);
248 }
249 
250 /*
251  * A variant of write(2) which handles partial write.
252  *
253  * Return the number of bytes transferred.
254  * Set errno if fewer than `count' bytes are written.
255  *
256  * This function don't work with non-blocking fd's.
257  * Any of the possibilities with non-bloking fd's is bad:
258  *   - return a short write (then name is wrong)
259  *   - busy wait adding (errno == EAGAIN) to the loop
260  */
qemu_write_full(int fd,const void * buf,size_t count)261 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
262 {
263     ssize_t ret = 0;
264     ssize_t total = 0;
265 
266     while (count) {
267         ret = write(fd, buf, count);
268         if (ret < 0) {
269             if (errno == EINTR)
270                 continue;
271             break;
272         }
273 
274         count -= ret;
275         buf += ret;
276         total += ret;
277     }
278 
279     return total;
280 }
281 
282 /*
283  * Opens a socket with FD_CLOEXEC set
284  */
qemu_socket(int domain,int type,int protocol)285 int qemu_socket(int domain, int type, int protocol)
286 {
287     int ret;
288 
289 #ifdef SOCK_CLOEXEC
290     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
291     if (ret != -1 || errno != EINVAL) {
292         return ret;
293     }
294 #endif
295     ret = socket(domain, type, protocol);
296     if (ret >= 0) {
297         qemu_set_cloexec(ret);
298     }
299 
300     return ret;
301 }
302 
303 #ifndef CONFIG_ANDROID
304 /*
305  * Accept a connection and set FD_CLOEXEC
306  */
qemu_accept(int s,struct sockaddr * addr,socklen_t * addrlen)307 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
308 {
309     int ret;
310 
311 #ifdef CONFIG_ACCEPT4
312     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
313     if (ret != -1 || errno != ENOSYS) {
314         return ret;
315     }
316 #endif
317     ret = accept(s, addr, addrlen);
318     if (ret >= 0) {
319         qemu_set_cloexec(ret);
320     }
321 
322     return ret;
323 }
324 #endif
325 
326 /*
327  * A variant of send(2) which handles partial write.
328  *
329  * Return the number of bytes transferred, which is only
330  * smaller than `count' if there is an error.
331  *
332  * This function won't work with non-blocking fd's.
333  * Any of the possibilities with non-bloking fd's is bad:
334  *   - return a short write (then name is wrong)
335  *   - busy wait adding (errno == EAGAIN) to the loop
336  */
qemu_send_full(int fd,const void * buf,size_t count,int flags)337 ssize_t qemu_send_full(int fd, const void *buf, size_t count, int flags)
338 {
339     ssize_t ret = 0;
340     ssize_t total = 0;
341 
342     while (count) {
343         ret = send(fd, buf, count, flags);
344         if (ret < 0) {
345             if (errno == EINTR) {
346                 continue;
347             }
348             break;
349         }
350 
351         count -= ret;
352         buf += ret;
353         total += ret;
354     }
355 
356     return total;
357 }
358 
359 /*
360  * A variant of recv(2) which handles partial write.
361  *
362  * Return the number of bytes transferred, which is only
363  * smaller than `count' if there is an error.
364  *
365  * This function won't work with non-blocking fd's.
366  * Any of the possibilities with non-bloking fd's is bad:
367  *   - return a short write (then name is wrong)
368  *   - busy wait adding (errno == EAGAIN) to the loop
369  */
qemu_recv_full(int fd,void * buf,size_t count,int flags)370 ssize_t qemu_recv_full(int fd, void *buf, size_t count, int flags)
371 {
372     ssize_t ret = 0;
373     ssize_t total = 0;
374 
375     while (count) {
376         ret = qemu_recv(fd, buf, count, flags);
377         if (ret <= 0) {
378             if (ret < 0 && errno == EINTR) {
379                 continue;
380             }
381             break;
382         }
383 
384         count -= ret;
385         buf += ret;
386         total += ret;
387     }
388 
389     return total;
390 }
391 
qemu_set_version(const char * version)392 void qemu_set_version(const char *version)
393 {
394     qemu_version = version;
395 }
396 
qemu_get_version(void)397 const char *qemu_get_version(void)
398 {
399     return qemu_version;
400 }
401 
fips_set_state(bool requested)402 void fips_set_state(bool requested)
403 {
404 #ifdef __linux__
405     if (requested) {
406         FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
407         if (fds != NULL) {
408             fips_enabled = (fgetc(fds) == '1');
409             fclose(fds);
410         }
411     }
412 #else
413     fips_enabled = false;
414 #endif /* __linux__ */
415 
416 #ifdef _FIPS_DEBUG
417     fprintf(stderr, "FIPS mode %s (requested %s)\n",
418 	    (fips_enabled ? "enabled" : "disabled"),
419 	    (requested ? "enabled" : "disabled"));
420 #endif
421 }
422 
fips_get_state(void)423 bool fips_get_state(void)
424 {
425     return fips_enabled;
426 }
427 
428 #ifndef CONFIG_ANDROID
429 #ifdef _WIN32
socket_cleanup(void)430 static void socket_cleanup(void)
431 {
432     WSACleanup();
433 }
434 #endif
435 
socket_init(void)436 int socket_init(void)
437 {
438 #ifdef _WIN32
439     WSADATA Data;
440     int ret, err;
441 
442     ret = WSAStartup(MAKEWORD(2, 2), &Data);
443     if (ret != 0) {
444         err = WSAGetLastError();
445         fprintf(stderr, "WSAStartup: %d\n", err);
446         return -1;
447     }
448     atexit(socket_cleanup);
449 #endif
450     return 0;
451 }
452 #endif  // !CONFIG_ANDROID
453 
454 #ifndef CONFIG_IOVEC
455 /* helper function for iov_send_recv() */
456 static ssize_t
readv_writev(int fd,const struct iovec * iov,int iov_cnt,bool do_write)457 readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
458 {
459     unsigned i = 0;
460     ssize_t ret = 0;
461     while (i < iov_cnt) {
462         ssize_t r = do_write
463             ? write(fd, iov[i].iov_base, iov[i].iov_len)
464             : read(fd, iov[i].iov_base, iov[i].iov_len);
465         if (r > 0) {
466             ret += r;
467         } else if (!r) {
468             break;
469         } else if (errno == EINTR) {
470             continue;
471         } else {
472             /* else it is some "other" error,
473              * only return if there was no data processed. */
474             if (ret == 0) {
475                 ret = -1;
476             }
477             break;
478         }
479         i++;
480     }
481     return ret;
482 }
483 
484 ssize_t
readv(int fd,const struct iovec * iov,int iov_cnt)485 readv(int fd, const struct iovec *iov, int iov_cnt)
486 {
487     return readv_writev(fd, iov, iov_cnt, false);
488 }
489 
490 ssize_t
writev(int fd,const struct iovec * iov,int iov_cnt)491 writev(int fd, const struct iovec *iov, int iov_cnt)
492 {
493     return readv_writev(fd, iov, iov_cnt, true);
494 }
495 #endif
496 
497 #if defined(_WIN32) && !QEMU_GNUC_PREREQ(4,4)
498 // Older Mingw32 didn't provide these.
499 int asprintf( char **, const char *, ... );
500 int vasprintf( char **, const char *, va_list );
501 
vasprintf(char ** sptr,const char * fmt,va_list argv)502 int vasprintf( char **sptr, const char *fmt, va_list argv )
503 {
504     int wanted = vsnprintf( *sptr = NULL, 0, fmt, argv );
505     if( (wanted > 0) && ((*sptr = malloc( 1 + wanted )) != NULL) )
506         return vsprintf( *sptr, fmt, argv );
507 
508     return wanted;
509 }
510 
asprintf(char ** sptr,const char * fmt,...)511 int asprintf( char **sptr, const char *fmt, ... )
512 {
513     int retval;
514     va_list argv;
515     va_start( argv, fmt );
516     retval = vasprintf( sptr, fmt, argv );
517     va_end( argv );
518     return retval;
519 }
520 #endif  // _WIN32 && !QEMU_GNUC_PREREQ(4,4)
521