xref: /openbmc/qemu/util/oslib-win32.c (revision 63785678)
1 /*
2  * os-win32.c
3  *
4  * Copyright (c) 2003-2008 Fabrice Bellard
5  * Copyright (c) 2010-2016 Red Hat, Inc.
6  *
7  * QEMU library functions for win32 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  * The implementation of g_poll (functions poll_rest, g_poll) at the end of
29  * this file are based on code from GNOME glib-2 and use a different license,
30  * see the license comment there.
31  */
32 #include "qemu/osdep.h"
33 #include <windows.h>
34 #include <glib.h>
35 #include "qapi/error.h"
36 #include "sysemu/sysemu.h"
37 #include "qemu/main-loop.h"
38 #include "trace.h"
39 #include "qemu/sockets.h"
40 #include "qemu/cutils.h"
41 
42 /* this must come after including "trace.h" */
43 #include <shlobj.h>
44 
45 void *qemu_oom_check(void *ptr)
46 {
47     if (ptr == NULL) {
48         fprintf(stderr, "Failed to allocate memory: %lu\n", GetLastError());
49         abort();
50     }
51     return ptr;
52 }
53 
54 void *qemu_try_memalign(size_t alignment, size_t size)
55 {
56     void *ptr;
57 
58     if (!size) {
59         abort();
60     }
61     ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
62     trace_qemu_memalign(alignment, size, ptr);
63     return ptr;
64 }
65 
66 void *qemu_memalign(size_t alignment, size_t size)
67 {
68     return qemu_oom_check(qemu_try_memalign(alignment, size));
69 }
70 
71 void *qemu_anon_ram_alloc(size_t size, uint64_t *align)
72 {
73     void *ptr;
74 
75     /* FIXME: this is not exactly optimal solution since VirtualAlloc
76        has 64Kb granularity, but at least it guarantees us that the
77        memory is page aligned. */
78     ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
79     trace_qemu_anon_ram_alloc(size, ptr);
80     return ptr;
81 }
82 
83 void qemu_vfree(void *ptr)
84 {
85     trace_qemu_vfree(ptr);
86     if (ptr) {
87         VirtualFree(ptr, 0, MEM_RELEASE);
88     }
89 }
90 
91 void qemu_anon_ram_free(void *ptr, size_t size)
92 {
93     trace_qemu_anon_ram_free(ptr, size);
94     if (ptr) {
95         VirtualFree(ptr, 0, MEM_RELEASE);
96     }
97 }
98 
99 #ifndef CONFIG_LOCALTIME_R
100 /* FIXME: add proper locking */
101 struct tm *gmtime_r(const time_t *timep, struct tm *result)
102 {
103     struct tm *p = gmtime(timep);
104     memset(result, 0, sizeof(*result));
105     if (p) {
106         *result = *p;
107         p = result;
108     }
109     return p;
110 }
111 
112 /* FIXME: add proper locking */
113 struct tm *localtime_r(const time_t *timep, struct tm *result)
114 {
115     struct tm *p = localtime(timep);
116     memset(result, 0, sizeof(*result));
117     if (p) {
118         *result = *p;
119         p = result;
120     }
121     return p;
122 }
123 #endif /* CONFIG_LOCALTIME_R */
124 
125 void qemu_set_block(int fd)
126 {
127     unsigned long opt = 0;
128     WSAEventSelect(fd, NULL, 0);
129     ioctlsocket(fd, FIONBIO, &opt);
130 }
131 
132 void qemu_set_nonblock(int fd)
133 {
134     unsigned long opt = 1;
135     ioctlsocket(fd, FIONBIO, &opt);
136     qemu_fd_register(fd);
137 }
138 
139 int socket_set_fast_reuse(int fd)
140 {
141     /* Enabling the reuse of an endpoint that was used by a socket still in
142      * TIME_WAIT state is usually performed by setting SO_REUSEADDR. On Windows
143      * fast reuse is the default and SO_REUSEADDR does strange things. So we
144      * don't have to do anything here. More info can be found at:
145      * http://msdn.microsoft.com/en-us/library/windows/desktop/ms740621.aspx */
146     return 0;
147 }
148 
149 
150 static int socket_error(void)
151 {
152     switch (WSAGetLastError()) {
153     case 0:
154         return 0;
155     case WSAEINTR:
156         return EINTR;
157     case WSAEINVAL:
158         return EINVAL;
159     case WSA_INVALID_HANDLE:
160         return EBADF;
161     case WSA_NOT_ENOUGH_MEMORY:
162         return ENOMEM;
163     case WSA_INVALID_PARAMETER:
164         return EINVAL;
165     case WSAENAMETOOLONG:
166         return ENAMETOOLONG;
167     case WSAENOTEMPTY:
168         return ENOTEMPTY;
169     case WSAEWOULDBLOCK:
170          /* not using EWOULDBLOCK as we don't want code to have
171           * to check both EWOULDBLOCK and EAGAIN */
172         return EAGAIN;
173     case WSAEINPROGRESS:
174         return EINPROGRESS;
175     case WSAEALREADY:
176         return EALREADY;
177     case WSAENOTSOCK:
178         return ENOTSOCK;
179     case WSAEDESTADDRREQ:
180         return EDESTADDRREQ;
181     case WSAEMSGSIZE:
182         return EMSGSIZE;
183     case WSAEPROTOTYPE:
184         return EPROTOTYPE;
185     case WSAENOPROTOOPT:
186         return ENOPROTOOPT;
187     case WSAEPROTONOSUPPORT:
188         return EPROTONOSUPPORT;
189     case WSAEOPNOTSUPP:
190         return EOPNOTSUPP;
191     case WSAEAFNOSUPPORT:
192         return EAFNOSUPPORT;
193     case WSAEADDRINUSE:
194         return EADDRINUSE;
195     case WSAEADDRNOTAVAIL:
196         return EADDRNOTAVAIL;
197     case WSAENETDOWN:
198         return ENETDOWN;
199     case WSAENETUNREACH:
200         return ENETUNREACH;
201     case WSAENETRESET:
202         return ENETRESET;
203     case WSAECONNABORTED:
204         return ECONNABORTED;
205     case WSAECONNRESET:
206         return ECONNRESET;
207     case WSAENOBUFS:
208         return ENOBUFS;
209     case WSAEISCONN:
210         return EISCONN;
211     case WSAENOTCONN:
212         return ENOTCONN;
213     case WSAETIMEDOUT:
214         return ETIMEDOUT;
215     case WSAECONNREFUSED:
216         return ECONNREFUSED;
217     case WSAELOOP:
218         return ELOOP;
219     case WSAEHOSTUNREACH:
220         return EHOSTUNREACH;
221     default:
222         return EIO;
223     }
224 }
225 
226 int inet_aton(const char *cp, struct in_addr *ia)
227 {
228     uint32_t addr = inet_addr(cp);
229     if (addr == 0xffffffff) {
230         return 0;
231     }
232     ia->s_addr = addr;
233     return 1;
234 }
235 
236 void qemu_set_cloexec(int fd)
237 {
238 }
239 
240 /* Offset between 1/1/1601 and 1/1/1970 in 100 nanosec units */
241 #define _W32_FT_OFFSET (116444736000000000ULL)
242 
243 int qemu_gettimeofday(qemu_timeval *tp)
244 {
245   union {
246     unsigned long long ns100; /*time since 1 Jan 1601 in 100ns units */
247     FILETIME ft;
248   }  _now;
249 
250   if(tp) {
251       GetSystemTimeAsFileTime (&_now.ft);
252       tp->tv_usec=(long)((_now.ns100 / 10ULL) % 1000000ULL );
253       tp->tv_sec= (long)((_now.ns100 - _W32_FT_OFFSET) / 10000000ULL);
254   }
255   /* Always return 0 as per Open Group Base Specifications Issue 6.
256      Do not set errno on error.  */
257   return 0;
258 }
259 
260 int qemu_get_thread_id(void)
261 {
262     return GetCurrentThreadId();
263 }
264 
265 char *
266 qemu_get_local_state_pathname(const char *relative_pathname)
267 {
268     HRESULT result;
269     char base_path[MAX_PATH+1] = "";
270 
271     result = SHGetFolderPath(NULL, CSIDL_COMMON_APPDATA, NULL,
272                              /* SHGFP_TYPE_CURRENT */ 0, base_path);
273     if (result != S_OK) {
274         /* misconfigured environment */
275         g_critical("CSIDL_COMMON_APPDATA unavailable: %ld", (long)result);
276         abort();
277     }
278     return g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s", base_path,
279                            relative_pathname);
280 }
281 
282 void qemu_set_tty_echo(int fd, bool echo)
283 {
284     HANDLE handle = (HANDLE)_get_osfhandle(fd);
285     DWORD dwMode = 0;
286 
287     if (handle == INVALID_HANDLE_VALUE) {
288         return;
289     }
290 
291     GetConsoleMode(handle, &dwMode);
292 
293     if (echo) {
294         SetConsoleMode(handle, dwMode | ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT);
295     } else {
296         SetConsoleMode(handle,
297                        dwMode & ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT));
298     }
299 }
300 
301 static char exec_dir[PATH_MAX];
302 
303 void qemu_init_exec_dir(const char *argv0)
304 {
305 
306     char *p;
307     char buf[MAX_PATH];
308     DWORD len;
309 
310     len = GetModuleFileName(NULL, buf, sizeof(buf) - 1);
311     if (len == 0) {
312         return;
313     }
314 
315     buf[len] = 0;
316     p = buf + len - 1;
317     while (p != buf && *p != '\\') {
318         p--;
319     }
320     *p = 0;
321     if (access(buf, R_OK) == 0) {
322         pstrcpy(exec_dir, sizeof(exec_dir), buf);
323     }
324 }
325 
326 char *qemu_get_exec_dir(void)
327 {
328     return g_strdup(exec_dir);
329 }
330 
331 /*
332  * The original implementation of g_poll from glib has a problem on Windows
333  * when using timeouts < 10 ms.
334  *
335  * Whenever g_poll is called with timeout < 10 ms, it does a quick poll instead
336  * of wait. This causes significant performance degradation of QEMU.
337  *
338  * The following code is a copy of the original code from glib/gpoll.c
339  * (glib commit 20f4d1820b8d4d0fc4447188e33efffd6d4a88d8 from 2014-02-19).
340  * Some debug code was removed and the code was reformatted.
341  * All other code modifications are marked with 'QEMU'.
342  */
343 
344 /*
345  * gpoll.c: poll(2) abstraction
346  * Copyright 1998 Owen Taylor
347  * Copyright 2008 Red Hat, Inc.
348  *
349  * This library is free software; you can redistribute it and/or
350  * modify it under the terms of the GNU Lesser General Public
351  * License as published by the Free Software Foundation; either
352  * version 2 of the License, or (at your option) any later version.
353  *
354  * This library is distributed in the hope that it will be useful,
355  * but WITHOUT ANY WARRANTY; without even the implied warranty of
356  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
357  * Lesser General Public License for more details.
358  *
359  * You should have received a copy of the GNU Lesser General Public
360  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
361  */
362 
363 static int poll_rest(gboolean poll_msgs, HANDLE *handles, gint nhandles,
364                      GPollFD *fds, guint nfds, gint timeout)
365 {
366     DWORD ready;
367     GPollFD *f;
368     int recursed_result;
369 
370     if (poll_msgs) {
371         /* Wait for either messages or handles
372          * -> Use MsgWaitForMultipleObjectsEx
373          */
374         ready = MsgWaitForMultipleObjectsEx(nhandles, handles, timeout,
375                                             QS_ALLINPUT, MWMO_ALERTABLE);
376 
377         if (ready == WAIT_FAILED) {
378             gchar *emsg = g_win32_error_message(GetLastError());
379             g_warning("MsgWaitForMultipleObjectsEx failed: %s", emsg);
380             g_free(emsg);
381         }
382     } else if (nhandles == 0) {
383         /* No handles to wait for, just the timeout */
384         if (timeout == INFINITE) {
385             ready = WAIT_FAILED;
386         } else {
387             SleepEx(timeout, TRUE);
388             ready = WAIT_TIMEOUT;
389         }
390     } else {
391         /* Wait for just handles
392          * -> Use WaitForMultipleObjectsEx
393          */
394         ready =
395             WaitForMultipleObjectsEx(nhandles, handles, FALSE, timeout, TRUE);
396         if (ready == WAIT_FAILED) {
397             gchar *emsg = g_win32_error_message(GetLastError());
398             g_warning("WaitForMultipleObjectsEx failed: %s", emsg);
399             g_free(emsg);
400         }
401     }
402 
403     if (ready == WAIT_FAILED) {
404         return -1;
405     } else if (ready == WAIT_TIMEOUT || ready == WAIT_IO_COMPLETION) {
406         return 0;
407     } else if (poll_msgs && ready == WAIT_OBJECT_0 + nhandles) {
408         for (f = fds; f < &fds[nfds]; ++f) {
409             if (f->fd == G_WIN32_MSG_HANDLE && f->events & G_IO_IN) {
410                 f->revents |= G_IO_IN;
411             }
412         }
413 
414         /* If we have a timeout, or no handles to poll, be satisfied
415          * with just noticing we have messages waiting.
416          */
417         if (timeout != 0 || nhandles == 0) {
418             return 1;
419         }
420 
421         /* If no timeout and handles to poll, recurse to poll them,
422          * too.
423          */
424         recursed_result = poll_rest(FALSE, handles, nhandles, fds, nfds, 0);
425         return (recursed_result == -1) ? -1 : 1 + recursed_result;
426     } else if (/* QEMU: removed the following unneeded statement which causes
427                 * a compiler warning: ready >= WAIT_OBJECT_0 && */
428                ready < WAIT_OBJECT_0 + nhandles) {
429         for (f = fds; f < &fds[nfds]; ++f) {
430             if ((HANDLE) f->fd == handles[ready - WAIT_OBJECT_0]) {
431                 f->revents = f->events;
432             }
433         }
434 
435         /* If no timeout and polling several handles, recurse to poll
436          * the rest of them.
437          */
438         if (timeout == 0 && nhandles > 1) {
439             /* Remove the handle that fired */
440             int i;
441             if (ready < nhandles - 1) {
442                 for (i = ready - WAIT_OBJECT_0 + 1; i < nhandles; i++) {
443                     handles[i-1] = handles[i];
444                 }
445             }
446             nhandles--;
447             recursed_result = poll_rest(FALSE, handles, nhandles, fds, nfds, 0);
448             return (recursed_result == -1) ? -1 : 1 + recursed_result;
449         }
450         return 1;
451     }
452 
453     return 0;
454 }
455 
456 gint g_poll(GPollFD *fds, guint nfds, gint timeout)
457 {
458     HANDLE handles[MAXIMUM_WAIT_OBJECTS];
459     gboolean poll_msgs = FALSE;
460     GPollFD *f;
461     gint nhandles = 0;
462     int retval;
463 
464     for (f = fds; f < &fds[nfds]; ++f) {
465         if (f->fd == G_WIN32_MSG_HANDLE && (f->events & G_IO_IN)) {
466             poll_msgs = TRUE;
467         } else if (f->fd > 0) {
468             /* Don't add the same handle several times into the array, as
469              * docs say that is not allowed, even if it actually does seem
470              * to work.
471              */
472             gint i;
473 
474             for (i = 0; i < nhandles; i++) {
475                 if (handles[i] == (HANDLE) f->fd) {
476                     break;
477                 }
478             }
479 
480             if (i == nhandles) {
481                 if (nhandles == MAXIMUM_WAIT_OBJECTS) {
482                     g_warning("Too many handles to wait for!\n");
483                     break;
484                 } else {
485                     handles[nhandles++] = (HANDLE) f->fd;
486                 }
487             }
488         }
489     }
490 
491     for (f = fds; f < &fds[nfds]; ++f) {
492         f->revents = 0;
493     }
494 
495     if (timeout == -1) {
496         timeout = INFINITE;
497     }
498 
499     /* Polling for several things? */
500     if (nhandles > 1 || (nhandles > 0 && poll_msgs)) {
501         /* First check if one or several of them are immediately
502          * available
503          */
504         retval = poll_rest(poll_msgs, handles, nhandles, fds, nfds, 0);
505 
506         /* If not, and we have a significant timeout, poll again with
507          * timeout then. Note that this will return indication for only
508          * one event, or only for messages. We ignore timeouts less than
509          * ten milliseconds as they are mostly pointless on Windows, the
510          * MsgWaitForMultipleObjectsEx() call will timeout right away
511          * anyway.
512          *
513          * Modification for QEMU: replaced timeout >= 10 by timeout > 0.
514          */
515         if (retval == 0 && (timeout == INFINITE || timeout > 0)) {
516             retval = poll_rest(poll_msgs, handles, nhandles,
517                                fds, nfds, timeout);
518         }
519     } else {
520         /* Just polling for one thing, so no need to check first if
521          * available immediately
522          */
523         retval = poll_rest(poll_msgs, handles, nhandles, fds, nfds, timeout);
524     }
525 
526     if (retval == -1) {
527         for (f = fds; f < &fds[nfds]; ++f) {
528             f->revents = 0;
529         }
530     }
531 
532     return retval;
533 }
534 
535 int getpagesize(void)
536 {
537     SYSTEM_INFO system_info;
538 
539     GetSystemInfo(&system_info);
540     return system_info.dwPageSize;
541 }
542 
543 void os_mem_prealloc(int fd, char *area, size_t memory)
544 {
545     int i;
546     size_t pagesize = getpagesize();
547 
548     memory = (memory + pagesize - 1) & -pagesize;
549     for (i = 0; i < memory / pagesize; i++) {
550         memset(area + pagesize * i, 0, 1);
551     }
552 }
553 
554 
555 /* XXX: put correct support for win32 */
556 int qemu_read_password(char *buf, int buf_size)
557 {
558     int c, i;
559 
560     printf("Password: ");
561     fflush(stdout);
562     i = 0;
563     for (;;) {
564         c = getchar();
565         if (c < 0) {
566             buf[i] = '\0';
567             return -1;
568         } else if (c == '\n') {
569             break;
570         } else if (i < (buf_size - 1)) {
571             buf[i++] = c;
572         }
573     }
574     buf[i] = '\0';
575     return 0;
576 }
577 
578 
579 pid_t qemu_fork(Error **errp)
580 {
581     errno = ENOSYS;
582     error_setg_errno(errp, errno,
583                      "cannot fork child process");
584     return -1;
585 }
586 
587 
588 #undef connect
589 int qemu_connect_wrap(int sockfd, const struct sockaddr *addr,
590                       socklen_t addrlen)
591 {
592     int ret;
593     ret = connect(sockfd, addr, addrlen);
594     if (ret < 0) {
595         errno = socket_error();
596     }
597     return ret;
598 }
599 
600 
601 #undef listen
602 int qemu_listen_wrap(int sockfd, int backlog)
603 {
604     int ret;
605     ret = listen(sockfd, backlog);
606     if (ret < 0) {
607         errno = socket_error();
608     }
609     return ret;
610 }
611 
612 
613 #undef bind
614 int qemu_bind_wrap(int sockfd, const struct sockaddr *addr,
615                    socklen_t addrlen)
616 {
617     int ret;
618     ret = bind(sockfd, addr, addrlen);
619     if (ret < 0) {
620         errno = socket_error();
621     }
622     return ret;
623 }
624 
625 
626 #undef socket
627 int qemu_socket_wrap(int domain, int type, int protocol)
628 {
629     int ret;
630     ret = socket(domain, type, protocol);
631     if (ret < 0) {
632         errno = socket_error();
633     }
634     return ret;
635 }
636 
637 
638 #undef accept
639 int qemu_accept_wrap(int sockfd, struct sockaddr *addr,
640                      socklen_t *addrlen)
641 {
642     int ret;
643     ret = accept(sockfd, addr, addrlen);
644     if (ret < 0) {
645         errno = socket_error();
646     }
647     return ret;
648 }
649 
650 
651 #undef shutdown
652 int qemu_shutdown_wrap(int sockfd, int how)
653 {
654     int ret;
655     ret = shutdown(sockfd, how);
656     if (ret < 0) {
657         errno = socket_error();
658     }
659     return ret;
660 }
661 
662 
663 #undef ioctlsocket
664 int qemu_ioctlsocket_wrap(int fd, int req, void *val)
665 {
666     int ret;
667     ret = ioctlsocket(fd, req, val);
668     if (ret < 0) {
669         errno = socket_error();
670     }
671     return ret;
672 }
673 
674 
675 #undef closesocket
676 int qemu_closesocket_wrap(int fd)
677 {
678     int ret;
679     ret = closesocket(fd);
680     if (ret < 0) {
681         errno = socket_error();
682     }
683     return ret;
684 }
685 
686 
687 #undef getsockopt
688 int qemu_getsockopt_wrap(int sockfd, int level, int optname,
689                          void *optval, socklen_t *optlen)
690 {
691     int ret;
692     ret = getsockopt(sockfd, level, optname, optval, optlen);
693     if (ret < 0) {
694         errno = socket_error();
695     }
696     return ret;
697 }
698 
699 
700 #undef setsockopt
701 int qemu_setsockopt_wrap(int sockfd, int level, int optname,
702                          const void *optval, socklen_t optlen)
703 {
704     int ret;
705     ret = setsockopt(sockfd, level, optname, optval, optlen);
706     if (ret < 0) {
707         errno = socket_error();
708     }
709     return ret;
710 }
711 
712 
713 #undef getpeername
714 int qemu_getpeername_wrap(int sockfd, struct sockaddr *addr,
715                           socklen_t *addrlen)
716 {
717     int ret;
718     ret = getpeername(sockfd, addr, addrlen);
719     if (ret < 0) {
720         errno = socket_error();
721     }
722     return ret;
723 }
724 
725 
726 #undef getsockname
727 int qemu_getsockname_wrap(int sockfd, struct sockaddr *addr,
728                           socklen_t *addrlen)
729 {
730     int ret;
731     ret = getsockname(sockfd, addr, addrlen);
732     if (ret < 0) {
733         errno = socket_error();
734     }
735     return ret;
736 }
737 
738 
739 #undef send
740 ssize_t qemu_send_wrap(int sockfd, const void *buf, size_t len, int flags)
741 {
742     int ret;
743     ret = send(sockfd, buf, len, flags);
744     if (ret < 0) {
745         errno = socket_error();
746     }
747     return ret;
748 }
749 
750 
751 #undef sendto
752 ssize_t qemu_sendto_wrap(int sockfd, const void *buf, size_t len, int flags,
753                          const struct sockaddr *addr, socklen_t addrlen)
754 {
755     int ret;
756     ret = sendto(sockfd, buf, len, flags, addr, addrlen);
757     if (ret < 0) {
758         errno = socket_error();
759     }
760     return ret;
761 }
762 
763 
764 #undef recv
765 ssize_t qemu_recv_wrap(int sockfd, void *buf, size_t len, int flags)
766 {
767     int ret;
768     ret = recv(sockfd, buf, len, flags);
769     if (ret < 0) {
770         errno = socket_error();
771     }
772     return ret;
773 }
774 
775 
776 #undef recvfrom
777 ssize_t qemu_recvfrom_wrap(int sockfd, void *buf, size_t len, int flags,
778                            struct sockaddr *addr, socklen_t *addrlen)
779 {
780     int ret;
781     ret = recvfrom(sockfd, buf, len, flags, addr, addrlen);
782     if (ret < 0) {
783         errno = socket_error();
784     }
785     return ret;
786 }
787