qemu/qemu.c - platform/hardware/libhardware_legacy - Git at Google

 /*
  * 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(...)   ALOGD(__VA_ARGS__)
 #else
 #  define  D(...)   ((void)0)
 #endif

 #include "hardware/qemu_pipe.h"

 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_pipe( QemuChannel*  channel,
                               const char*   name )
 {
     int   fd;
     char  pipe_name[512];

     snprintf(pipe_name, sizeof(pipe_name), "qemud:%s", name);
     fd = qemu_pipe_open(pipe_name);
     if (fd < 0) {
         D("no qemud pipe: %s", strerror(errno));
         return -1;
     }

     channel->is_qemud = 1;
     channel->fd       = fd;
     return 0;
 }

 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_pipe(channel, name) == 0)
                 break;

             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_vformat(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;
 }
	/*
	* 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(...) ALOGD(__VA_ARGS__)
	#else
	# define D(...) ((void)0)
	#endif

	#include "hardware/qemu_pipe.h"

	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_pipe( QemuChannel* channel,
	const char* name )
	{
	int fd;
	char pipe_name[512];

	snprintf(pipe_name, sizeof(pipe_name), "qemud:%s", name);
	fd = qemu_pipe_open(pipe_name);
	if (fd < 0) {
	D("no qemud pipe: %s", strerror(errno));
	return -1;
	}

	channel->is_qemud = 1;
	channel->fd = fd;
	return 0;
	}

	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_pipe(channel, name) == 0)
	break;

	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_vformat(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;
	}