/*
* QEMU low level functions
*
* Copyright (c) 2003 Fabrice Bellard
*
* 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 "qemu/osdep.h"
#include "qapi/error.h"
#include "qemu/cutils.h"
#include "qemu/sockets.h"
#include "qemu/error-report.h"
#include "qemu/madvise.h"
#include "qemu/mprotect.h"
#include "qemu/hw-version.h"
#include "monitor/monitor.h"
static const char *hw_version = QEMU_HW_VERSION;
int socket_set_cork(int fd, int v)
{
#if defined(SOL_TCP) && defined(TCP_CORK)
return setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
#else
return 0;
#endif
}
int socket_set_nodelay(int fd)
{
int v = 1;
return setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
}
int qemu_madvise(void *addr, size_t len, int advice)
{
if (advice == QEMU_MADV_INVALID) {
errno = EINVAL;
return -1;
}
#if defined(CONFIG_MADVISE)
return madvise(addr, len, advice);
#elif defined(CONFIG_POSIX_MADVISE)
return posix_madvise(addr, len, advice);
#else
errno = EINVAL;
return -1;
#endif
}
static int qemu_mprotect__osdep(void *addr, size_t size, int prot)
{
g_assert(!((uintptr_t)addr & ~qemu_real_host_page_mask()));
g_assert(!(size & ~qemu_real_host_page_mask()));
#ifdef _WIN32
DWORD old_protect;
if (!VirtualProtect(addr, size, prot, &old_protect)) {
g_autofree gchar *emsg = g_win32_error_message(GetLastError());
error_report("%s: VirtualProtect failed: %s", __func__, emsg);
return -1;
}
return 0;
#else
if (mprotect(addr, size, prot)) {
error_report("%s: mprotect failed: %s", __func__, strerror(errno));
return -1;
}
return 0;
#endif
}
int qemu_mprotect_rw(void *addr, size_t size)
{
#ifdef _WIN32
return qemu_mprotect__osdep(addr, size, PAGE_READWRITE);
#else
return qemu_mprotect__osdep(addr, size, PROT_READ | PROT_WRITE);
#endif
}
int qemu_mprotect_rwx(void *addr, size_t size)
{
#ifdef _WIN32
return qemu_mprotect__osdep(addr, size, PAGE_EXECUTE_READWRITE);
#else
return qemu_mprotect__osdep(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC);
#endif
}
int qemu_mprotect_none(void *addr, size_t size)
{
#ifdef _WIN32
return qemu_mprotect__osdep(addr, size, PAGE_NOACCESS);
#else
return qemu_mprotect__osdep(addr, size, PROT_NONE);
#endif
}
#ifndef _WIN32
static int fcntl_op_setlk = -1;
static int fcntl_op_getlk = -1;
/*
* Dups an fd and sets the flags
*/
int qemu_dup_flags(int fd, int flags)
{
int ret;
int serrno;
int dup_flags;
ret = qemu_dup(fd);
if (ret == -1) {
goto fail;
}
dup_flags = fcntl(ret, F_GETFL);
if (dup_flags == -1) {
goto fail;
}
if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
errno = EINVAL;
goto fail;
}
/* Set/unset flags that we can with fcntl */
if (fcntl(ret, F_SETFL, flags) == -1) {
goto fail;
}
/* Truncate the file in the cases that open() would truncate it */
if (flags & O_TRUNC ||
((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) {
if (ftruncate(ret, 0) == -1) {
goto fail;
}
}
return ret;
fail:
serrno = errno;
if (ret != -1) {
close(ret);
}
errno = serrno;
return -1;
}
int qemu_dup(int fd)
{
int ret;
#ifdef F_DUPFD_CLOEXEC
ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
#else
ret = dup(fd);
if (ret != -1) {
qemu_set_cloexec(ret);
}
#endif
return ret;
}
static int qemu_parse_fdset(const char *param)
{
return qemu_parse_fd(param);
}
static void qemu_probe_lock_ops(void)
{
if (fcntl_op_setlk == -1) {
#ifdef F_OFD_SETLK
int fd;
int ret;
struct flock fl = {
.l_whence = SEEK_SET,
.l_start = 0,
.l_len = 0,
.l_type = F_WRLCK,
};
fd = open("/dev/null", O_RDWR);
if (fd < 0) {
fprintf(stderr,
"Failed to open /dev/null for OFD lock probing: %s\n",
strerror(errno));
fcntl_op_setlk = F_SETLK;
fcntl_op_getlk = F_GETLK;
return;
}
ret = fcntl(fd, F_OFD_GETLK, &fl);
close(fd);
if (!ret) {
fcntl_op_setlk = F_OFD_SETLK;
fcntl_op_getlk = F_OFD_GETLK;
} else {
fcntl_op_setlk = F_SETLK;
fcntl_op_getlk = F_GETLK;
}
#else
fcntl_op_setlk = F_SETLK;
fcntl_op_getlk = F_GETLK;
#endif
}
}
bool qemu_has_ofd_lock(void)
{
qemu_probe_lock_ops();
#ifdef F_OFD_SETLK
return fcntl_op_setlk == F_OFD_SETLK;
#else
return false;
#endif
}
static int qemu_lock_fcntl(int fd, int64_t start, int64_t len, int fl_type)
{
int ret;
struct flock fl = {
.l_whence = SEEK_SET,
.l_start = start,
.l_len = len,
.l_type = fl_type,
};
qemu_probe_lock_ops();
do {
ret = fcntl(fd, fcntl_op_setlk, &fl);
} while (ret == -1 && errno == EINTR);
return ret == -1 ? -errno : 0;
}
int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive)
{
return qemu_lock_fcntl(fd, start, len, exclusive ? F_WRLCK : F_RDLCK);
}
int qemu_unlock_fd(int fd, int64_t start, int64_t len)
{
return qemu_lock_fcntl(fd, start, len, F_UNLCK);
}
int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive)
{
int ret;
struct flock fl = {
.l_whence = SEEK_SET,
.l_start = start,
.l_len = len,
.l_type = exclusive ? F_WRLCK : F_RDLCK,
};
qemu_probe_lock_ops();
ret = fcntl(fd, fcntl_op_getlk, &fl);
if (ret == -1) {
return -errno;
} else {
return fl.l_type == F_UNLCK ? 0 : -EAGAIN;
}
}
#endif
static int qemu_open_cloexec(const char *name, int flags, mode_t mode)
{
int ret;
#ifdef O_CLOEXEC
ret = open(name, flags | O_CLOEXEC, mode);
#else
ret = open(name, flags, mode);
if (ret >= 0) {
qemu_set_cloexec(ret);
}
#endif
return ret;
}
/*
* Opens a file with FD_CLOEXEC set
*/
static int
qemu_open_internal(const char *name, int flags, mode_t mode, Error **errp)
{
int ret;
#ifndef _WIN32
const char *fdset_id_str;
/* Attempt dup of fd from fd set */
if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
int64_t fdset_id;
int dupfd;
fdset_id = qemu_parse_fdset(fdset_id_str);
if (fdset_id == -1) {
error_setg(errp, "Could not parse fdset %s", name);
errno = EINVAL;
return -1;
}
dupfd = monitor_fdset_dup_fd_add(fdset_id, flags);
if (dupfd == -1) {
error_setg_errno(errp, errno, "Could not dup FD for %s flags %x",
name, flags);
return -1;
}
return dupfd;
}
#endif
ret = qemu_open_cloexec(name, flags, mode);
if (ret == -1) {
const char *action = flags & O_CREAT ? "create" : "open";
#ifdef O_DIRECT
/* Give more helpful error message for O_DIRECT */
if (errno == EINVAL && (flags & O_DIRECT)) {
ret = open(name, flags & ~O_DIRECT, mode);
if (ret != -1) {
close(ret);
error_setg(errp, "Could not %s '%s': "
"filesystem does not support O_DIRECT",
action, name);
errno = EINVAL; /* restore first open()'s errno */
return -1;
}
}
#endif /* O_DIRECT */
error_setg_errno(errp, errno, "Could not %s '%s'",
action, name);
}
return ret;
}
int qemu_open(const char *name, int flags, Error **errp)
{
assert(!(flags & O_CREAT));
return qemu_open_internal(name, flags, 0, errp);
}
int qemu_create(const char *name, int flags, mode_t mode, Error **errp)
{
assert(!(flags & O_CREAT));
return qemu_open_internal(name, flags | O_CREAT, mode, errp);
}
int qemu_open_old(const char *name, int flags, ...)
{
va_list ap;
mode_t mode = 0;
int ret;
va_start(ap, flags);
if (flags & O_CREAT) {
mode = va_arg(ap, int);
}
va_end(ap);
ret = qemu_open_internal(name, flags, mode, NULL);
#ifdef O_DIRECT
if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
error_report("file system may not support O_DIRECT");
errno = EINVAL; /* in case it was clobbered */
}
#endif /* O_DIRECT */
return ret;
}
int qemu_close(int fd)
{
int64_t fdset_id;
/* Close fd that was dup'd from an fdset */
fdset_id = monitor_fdset_dup_fd_find(fd);
if (fdset_id != -1) {
int ret;
ret = close(fd);
if (ret == 0) {
monitor_fdset_dup_fd_remove(fd);
}
return ret;
}
return close(fd);
}
/*
* Delete a file from the filesystem, unless the filename is /dev/fdset/...
*
* Returns: On success, zero is returned. On error, -1 is returned,
* and errno is set appropriately.
*/
int qemu_unlink(const char *name)
{
if (g_str_has_prefix(name, "/dev/fdset/")) {
return 0;
}
return unlink(name);
}
/*
* A variant of write(2) which handles partial write.
*
* Return the number of bytes transferred.
* Set errno if fewer than `count' bytes are written.
*
* This function don't work with non-blocking fd's.
* Any of the possibilities with non-blocking fd's is bad:
* - return a short write (then name is wrong)
* - busy wait adding (errno == EAGAIN) to the loop
*/
ssize_t qemu_write_full(int fd, const void *buf, size_t count)
{
ssize_t ret = 0;
ssize_t total = 0;
while (count) {
ret = write(fd, buf, count);
if (ret < 0) {
if (errno == EINTR)
continue;
break;
}
count -= ret;
buf += ret;
total += ret;
}
return total;
}
/*
* Opens a socket with FD_CLOEXEC set
*/
int qemu_socket(int domain, int type, int protocol)
{
int ret;
#ifdef SOCK_CLOEXEC
ret = socket(domain, type | SOCK_CLOEXEC, protocol);
if (ret != -1 || errno != EINVAL) {
return ret;
}
#endif
ret = socket(domain, type, protocol);
if (ret >= 0) {
qemu_set_cloexec(ret);
}
return ret;
}
/*
* Accept a connection and set FD_CLOEXEC
*/
int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
{
int ret;
#ifdef CONFIG_ACCEPT4
ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
if (ret != -1 || errno != ENOSYS) {
return ret;
}
#endif
ret = accept(s, addr, addrlen);
if (ret >= 0) {
qemu_set_cloexec(ret);
}
return ret;
}
ssize_t qemu_send_full(int s, const void *buf, size_t count)
{
ssize_t ret = 0;
ssize_t total = 0;
while (count) {
ret = send(s, buf, count, 0);
if (ret < 0) {
if (errno == EINTR) {
continue;
}
break;
}
count -= ret;
buf += ret;
total += ret;
}
return total;
}
void qemu_set_hw_version(const char *version)
{
hw_version = version;
}
const char *qemu_hw_version(void)
{
return hw_version;
}
#ifdef _WIN32
static void socket_cleanup(void)
{
WSACleanup();
}
#endif
int socket_init(void)
{
#ifdef _WIN32
WSADATA Data;
int ret, err;
ret = WSAStartup(MAKEWORD(2, 2), &Data);
if (ret != 0) {
err = WSAGetLastError();
fprintf(stderr, "WSAStartup: %d\n", err);
return -1;
}
atexit(socket_cleanup);
#endif
return 0;
}
#ifndef CONFIG_IOVEC
static ssize_t
readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
{
unsigned i = 0;
ssize_t ret = 0;
ssize_t off = 0;
while (i < iov_cnt) {
ssize_t r = do_write
? write(fd, iov[i].iov_base + off, iov[i].iov_len - off)
: read(fd, iov[i].iov_base + off, iov[i].iov_len - off);
if (r > 0) {
ret += r;
off += r;
if (off < iov[i].iov_len) {
continue;
}
} else if (!r) {
break;
} else if (errno == EINTR) {
continue;
} else {
/* else it is some "other" error,
* only return if there was no data processed. */
if (ret == 0) {
ret = -1;
}
break;
}
off = 0;
i++;
}
return ret;
}
ssize_t
readv(int fd, const struct iovec *iov, int iov_cnt)
{
return readv_writev(fd, iov, iov_cnt, false);
}
ssize_t
writev(int fd, const struct iovec *iov, int iov_cnt)
{
return readv_writev(fd, iov, iov_cnt, true);
}
#endif
/*
* Make sure data goes on disk, but if possible do not bother to
* write out the inode just for timestamp updates.
*
* Unfortunately even in 2009 many operating systems do not support
* fdatasync and have to fall back to fsync.
*/
int qemu_fdatasync(int fd)
{
#ifdef CONFIG_FDATASYNC
return fdatasync(fd);
#else
return fsync(fd);
#endif
}
