Skip to content
Find file
Fetching contributors…
Cannot retrieve contributors at this time
380 lines (315 sloc) 8.81 KB
/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* this file contains various functions used by all libhardware modules
* that support QEMU emulation
*/
#include "qemu.h"
#define LOG_TAG "hardware-qemu"
#include <cutils/log.h>
#include <cutils/properties.h>
#include <cutils/sockets.h>
#include <errno.h>
#include <fcntl.h>
#include <termios.h>
#include <stdio.h>
#include <stdarg.h>
#define QEMU_DEBUG 0
#if QEMU_DEBUG
# define D(...) LOGD(__VA_ARGS__)
#else
# define D(...) ((void)0)
#endif
int
qemu_check(void)
{
static int in_qemu = -1;
if (__builtin_expect(in_qemu < 0,0)) {
char propBuf[PROPERTY_VALUE_MAX];
property_get("ro.kernel.qemu", propBuf, "");
in_qemu = (propBuf[0] == '1');
}
return in_qemu;
}
static int
qemu_fd_write( int fd, const char* cmd, int len )
{
int len2;
do {
len2 = write(fd, cmd, len);
} while (len2 < 0 && errno == EINTR);
return len2;
}
static int
qemu_fd_read( int fd, char* buff, int len )
{
int len2;
do {
len2 = read(fd, buff, len);
} while (len2 < 0 && errno == EINTR);
return len2;
}
static int
qemu_channel_open_qemud( QemuChannel* channel,
const char* name )
{
int fd, ret, namelen = strlen(name);
char answer[2];
fd = socket_local_client( "qemud",
ANDROID_SOCKET_NAMESPACE_RESERVED,
SOCK_STREAM );
if (fd < 0) {
D("no qemud control socket: %s", strerror(errno));
return -1;
}
/* send service name to connect */
if (qemu_fd_write(fd, name, namelen) != namelen) {
D("can't send service name to qemud: %s",
strerror(errno));
close(fd);
return -1;
}
/* read answer from daemon */
if (qemu_fd_read(fd, answer, 2) != 2 ||
answer[0] != 'O' || answer[1] != 'K') {
D("cant' connect to %s service through qemud", name);
close(fd);
return -1;
}
channel->is_qemud = 1;
channel->fd = fd;
return 0;
}
static int
qemu_channel_open_qemud_old( QemuChannel* channel,
const char* name )
{
int fd;
snprintf(channel->device, sizeof channel->device,
"qemud_%s", name);
fd = socket_local_client( channel->device,
ANDROID_SOCKET_NAMESPACE_RESERVED,
SOCK_STREAM );
if (fd < 0) {
D("no '%s' control socket available: %s",
channel->device, strerror(errno));
return -1;
}
close(fd);
channel->is_qemud_old = 1;
return 0;
}
static int
qemu_channel_open_tty( QemuChannel* channel,
const char* name,
int mode )
{
char key[PROPERTY_KEY_MAX];
char prop[PROPERTY_VALUE_MAX];
int ret;
ret = snprintf(key, sizeof key, "ro.kernel.android.%s", name);
if (ret >= (int)sizeof key)
return -1;
if (property_get(key, prop, "") == 0) {
D("no kernel-provided %s device name", name);
return -1;
}
ret = snprintf(channel->device, sizeof channel->device,
"/dev/%s", prop);
if (ret >= (int)sizeof channel->device) {
D("%s device name too long: '%s'", name, prop);
return -1;
}
channel->is_tty = !memcmp("/dev/tty", channel->device, 8);
return 0;
}
int
qemu_channel_open( QemuChannel* channel,
const char* name,
int mode )
{
int fd = -1;
/* initialize the channel is needed */
if (!channel->is_inited)
{
channel->is_inited = 1;
do {
if (qemu_channel_open_qemud(channel, name) == 0)
break;
if (qemu_channel_open_qemud_old(channel, name) == 0)
break;
if (qemu_channel_open_tty(channel, name, mode) == 0)
break;
channel->is_available = 0;
return -1;
} while (0);
channel->is_available = 1;
}
/* try to open the file */
if (!channel->is_available) {
errno = ENOENT;
return -1;
}
if (channel->is_qemud) {
return dup(channel->fd);
}
if (channel->is_qemud_old) {
do {
fd = socket_local_client( channel->device,
ANDROID_SOCKET_NAMESPACE_RESERVED,
SOCK_STREAM );
} while (fd < 0 && errno == EINTR);
}
else /* /dev/ttySn ? */
{
do {
fd = open(channel->device, mode);
} while (fd < 0 && errno == EINTR);
/* disable ECHO on serial lines */
if (fd >= 0 && channel->is_tty) {
struct termios ios;
tcgetattr( fd, &ios );
ios.c_lflag = 0; /* disable ECHO, ICANON, etc... */
tcsetattr( fd, TCSANOW, &ios );
}
}
return fd;
}
static int
qemu_command_vformat( char* buffer,
int buffer_size,
const char* format,
va_list args )
{
char header[5];
int len;
if (buffer_size < 6)
return -1;
len = vsnprintf(buffer+4, buffer_size-4, format, args);
if (len >= buffer_size-4)
return -1;
snprintf(header, sizeof header, "%04x", len);
memcpy(buffer, header, 4);
return len + 4;
}
extern int
qemu_command_format( char* buffer,
int buffer_size,
const char* format,
... )
{
va_list args;
int ret;
va_start(args, format);
ret = qemu_command_format(buffer, buffer_size, format, args);
va_end(args);
return ret;
}
static int
qemu_control_fd(void)
{
static QemuChannel channel[1];
int fd;
fd = qemu_channel_open( channel, "hw-control", O_RDWR );
if (fd < 0) {
D("%s: could not open control channel: %s", __FUNCTION__,
strerror(errno));
}
return fd;
}
static int
qemu_control_send(const char* cmd, int len)
{
int fd, len2;
if (len < 0) {
errno = EINVAL;
return -1;
}
fd = qemu_control_fd();
if (fd < 0)
return -1;
len2 = qemu_fd_write(fd, cmd, len);
close(fd);
if (len2 != len) {
D("%s: could not send everything %d < %d",
__FUNCTION__, len2, len);
return -1;
}
return 0;
}
int
qemu_control_command( const char* fmt, ... )
{
va_list args;
char command[256];
int len, fd;
va_start(args, fmt);
len = qemu_command_vformat( command, sizeof command, fmt, args );
va_end(args);
if (len < 0 || len >= (int)sizeof command) {
if (len < 0) {
D("%s: could not send: %s", __FUNCTION__, strerror(errno));
} else {
D("%s: too large %d > %d", __FUNCTION__, len, (int)(sizeof command));
}
errno = EINVAL;
return -1;
}
return qemu_control_send( command, len );
}
extern int qemu_control_query( const char* question, int questionlen,
char* answer, int answersize )
{
int ret, fd, len, result = -1;
char header[5], *end;
if (questionlen <= 0) {
errno = EINVAL;
return -1;
}
fd = qemu_control_fd();
if (fd < 0)
return -1;
ret = qemu_fd_write( fd, question, questionlen );
if (ret != questionlen) {
D("%s: could not write all: %d < %d", __FUNCTION__,
ret, questionlen);
goto Exit;
}
/* read a 4-byte header giving the length of the following content */
ret = qemu_fd_read( fd, header, 4 );
if (ret != 4) {
D("%s: could not read header (%d != 4)",
__FUNCTION__, ret);
goto Exit;
}
header[4] = 0;
len = strtol( header, &end, 16 );
if ( len < 0 || end == NULL || end != header+4 || len > answersize ) {
D("%s: could not parse header: '%s'",
__FUNCTION__, header);
goto Exit;
}
/* read the answer */
ret = qemu_fd_read( fd, answer, len );
if (ret != len) {
D("%s: could not read all of answer %d < %d",
__FUNCTION__, ret, len);
goto Exit;
}
result = len;
Exit:
close(fd);
return result;
}
Something went wrong with that request. Please try again.