| /* |
| * 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; |
| } |
| |
| |
| int |
| qemu_channel_open( QemuChannel* channel, |
| const char* name, |
| int mode ) |
| { |
| int fd = -1; |
| |
| /* initialize the channel is needed */ |
| if (!channel->is_inited) |
| { |
| int done = 0; |
| |
| // try to connect to qemud socket first |
| do { |
| 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)); |
| break; |
| } |
| close(fd); |
| channel->is_qemud = 1; |
| done = 1; |
| } while (0); |
| |
| // otherwise, look for a kernel-provided device name |
| if (!done) do { |
| 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) |
| break; |
| |
| if (property_get(key, prop, "") == 0) { |
| D("no kernel-provided %s device name", name); |
| break; |
| } |
| |
| 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); |
| break; |
| } |
| channel->is_tty = !memcmp("/dev/tty", channel->device, 8); |
| done = 1; |
| |
| } while (0); |
| |
| channel->is_available = done; |
| channel->is_inited = 1; |
| } |
| |
| /* try to open the file */ |
| if (!channel->is_available) { |
| fd = -1; |
| errno = ENOENT; |
| } else if (channel->is_qemud) { |
| do { |
| fd = socket_local_client( channel->device, |
| ANDROID_SOCKET_NAMESPACE_RESERVED, |
| SOCK_STREAM ); |
| } while (fd < 0 && errno == EINTR); |
| } else { |
| 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, "control", O_RDWR ); |
| if (fd < 0) { |
| D("%s: could not open control channel: %s", __FUNCTION__, |
| strerror(errno)); |
| } |
| return fd; |
| } |
| |
| static int |
| qemu_control_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_control_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_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_control_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_control_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_control_read( fd, header, 4 ); |
| if (ret != 4) { |
| D("%s: could not read header (%d != 4)", |
| __FUNCTION__, ret); |
| goto Exit; |
| } |
| |
| header[5] = 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_control_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; |
| } |