qemu/util/oslib-win32.c
Sebastian Ottlik 606600a176 util: add socket_set_fast_reuse function which will replace setting SO_REUSEADDR
If a socket is closed it remains in TIME_WAIT state for some time. On operating
systems using BSD sockets the endpoint of the socket may not be reused while in
this state unless SO_REUSEADDR was set on the socket. On windows on the other
hand the default behaviour is to allow reuse (i.e. identical to SO_REUSEADDR on
other operating systems) and setting SO_REUSEADDR on a socket allows it to be
bound to a endpoint even if the endpoint is already used by another socket
independently of the other sockets state. This can even result in undefined
behaviour.

Many sockets used by QEMU should not block the use of their endpoint after being
closed while they are still in TIME_WAIT state. Currently QEMU sets SO_REUSEADDR
for such sockets, which can lead to problems on Windows. This patch introduces
the function socket_set_fast_reuse that should be used instead of setting
SO_REUSEADDR when fast socket reuse is desired and behaves correctly on all
operating systems.

As a failure of this function can only be caused by bad QEMU internal errors, an
assertion handles these situations. The return value is still passed on, to
minimize changes in client code and prevent unused variable warnings if NDEBUG
is defined.

Signed-off-by: Sebastian Ottlik <ottlik@fzi.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
2013-10-02 19:20:31 +02:00

192 lines
5.0 KiB
C

/*
* os-win32.c
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2010 Red Hat, Inc.
*
* QEMU library functions for win32 which are shared between QEMU and
* the QEMU tools.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <windows.h>
#include <glib.h>
#include <stdlib.h>
#include "config-host.h"
#include "sysemu/sysemu.h"
#include "qemu/main-loop.h"
#include "trace.h"
#include "qemu/sockets.h"
/* this must come after including "trace.h" */
#include <shlobj.h>
void *qemu_oom_check(void *ptr)
{
if (ptr == NULL) {
fprintf(stderr, "Failed to allocate memory: %lu\n", GetLastError());
abort();
}
return ptr;
}
void *qemu_memalign(size_t alignment, size_t size)
{
void *ptr;
if (!size) {
abort();
}
ptr = qemu_oom_check(VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE));
trace_qemu_memalign(alignment, size, ptr);
return ptr;
}
void *qemu_anon_ram_alloc(size_t size)
{
void *ptr;
/* FIXME: this is not exactly optimal solution since VirtualAlloc
has 64Kb granularity, but at least it guarantees us that the
memory is page aligned. */
ptr = VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
trace_qemu_anon_ram_alloc(size, ptr);
return ptr;
}
void qemu_vfree(void *ptr)
{
trace_qemu_vfree(ptr);
if (ptr) {
VirtualFree(ptr, 0, MEM_RELEASE);
}
}
void qemu_anon_ram_free(void *ptr, size_t size)
{
trace_qemu_anon_ram_free(ptr, size);
if (ptr) {
VirtualFree(ptr, 0, MEM_RELEASE);
}
}
/* FIXME: add proper locking */
struct tm *gmtime_r(const time_t *timep, struct tm *result)
{
struct tm *p = gmtime(timep);
memset(result, 0, sizeof(*result));
if (p) {
*result = *p;
p = result;
}
return p;
}
/* FIXME: add proper locking */
struct tm *localtime_r(const time_t *timep, struct tm *result)
{
struct tm *p = localtime(timep);
memset(result, 0, sizeof(*result));
if (p) {
*result = *p;
p = result;
}
return p;
}
void qemu_set_block(int fd)
{
unsigned long opt = 0;
WSAEventSelect(fd, NULL, 0);
ioctlsocket(fd, FIONBIO, &opt);
}
void qemu_set_nonblock(int fd)
{
unsigned long opt = 1;
ioctlsocket(fd, FIONBIO, &opt);
qemu_fd_register(fd);
}
int socket_set_fast_reuse(int fd)
{
/* Enabling the reuse of an endpoint that was used by a socket still in
* TIME_WAIT state is usually performed by setting SO_REUSEADDR. On Windows
* fast reuse is the default and SO_REUSEADDR does strange things. So we
* don't have to do anything here. More info can be found at:
* http://msdn.microsoft.com/en-us/library/windows/desktop/ms740621.aspx */
return 0;
}
int inet_aton(const char *cp, struct in_addr *ia)
{
uint32_t addr = inet_addr(cp);
if (addr == 0xffffffff) {
return 0;
}
ia->s_addr = addr;
return 1;
}
void qemu_set_cloexec(int fd)
{
}
/* Offset between 1/1/1601 and 1/1/1970 in 100 nanosec units */
#define _W32_FT_OFFSET (116444736000000000ULL)
int qemu_gettimeofday(qemu_timeval *tp)
{
union {
unsigned long long ns100; /*time since 1 Jan 1601 in 100ns units */
FILETIME ft;
} _now;
if(tp) {
GetSystemTimeAsFileTime (&_now.ft);
tp->tv_usec=(long)((_now.ns100 / 10ULL) % 1000000ULL );
tp->tv_sec= (long)((_now.ns100 - _W32_FT_OFFSET) / 10000000ULL);
}
/* Always return 0 as per Open Group Base Specifications Issue 6.
Do not set errno on error. */
return 0;
}
int qemu_get_thread_id(void)
{
return GetCurrentThreadId();
}
char *
qemu_get_local_state_pathname(const char *relative_pathname)
{
HRESULT result;
char base_path[MAX_PATH+1] = "";
result = SHGetFolderPath(NULL, CSIDL_COMMON_APPDATA, NULL,
/* SHGFP_TYPE_CURRENT */ 0, base_path);
if (result != S_OK) {
/* misconfigured environment */
g_critical("CSIDL_COMMON_APPDATA unavailable: %ld", (long)result);
abort();
}
return g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s", base_path,
relative_pathname);
}