1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* this file contains various functions used by all libhardware modules 18 * that support QEMU emulation 19 */ 20 #include "qemu.h" 21 #define LOG_TAG "hardware-qemu" 22 #include <cutils/log.h> 23 #include <cutils/properties.h> 24 #include <cutils/sockets.h> 25 #include <errno.h> 26 #include <fcntl.h> 27 #include <termios.h> 28 #include <stdio.h> 29 #include <stdarg.h> 30 31 #define QEMU_DEBUG 0 32 33 #if QEMU_DEBUG 34 # define D(...) ALOGD(__VA_ARGS__) 35 #else 36 # define D(...) ((void)0) 37 #endif 38 39 #include "hardware/qemu_pipe.h" 40 41 int 42 qemu_check(void) 43 { 44 static int in_qemu = -1; 45 46 if (__builtin_expect(in_qemu < 0,0)) { 47 char propBuf[PROPERTY_VALUE_MAX]; 48 property_get("ro.kernel.qemu", propBuf, ""); 49 in_qemu = (propBuf[0] == '1'); 50 } 51 return in_qemu; 52 } 53 54 static int 55 qemu_fd_write( int fd, const char* cmd, int len ) 56 { 57 int len2; 58 do { 59 len2 = write(fd, cmd, len); 60 } while (len2 < 0 && errno == EINTR); 61 return len2; 62 } 63 64 static int 65 qemu_fd_read( int fd, char* buff, int len ) 66 { 67 int len2; 68 do { 69 len2 = read(fd, buff, len); 70 } while (len2 < 0 && errno == EINTR); 71 return len2; 72 } 73 74 static int 75 qemu_channel_open_qemud_pipe( QemuChannel* channel, 76 const char* name ) 77 { 78 int fd; 79 char pipe_name[512]; 80 81 snprintf(pipe_name, sizeof(pipe_name), "qemud:%s", name); 82 fd = qemu_pipe_open(pipe_name); 83 if (fd < 0) { 84 D("no qemud pipe: %s", strerror(errno)); 85 return -1; 86 } 87 88 channel->is_qemud = 1; 89 channel->fd = fd; 90 return 0; 91 } 92 93 static int 94 qemu_channel_open_qemud( QemuChannel* channel, 95 const char* name ) 96 { 97 int fd, ret, namelen = strlen(name); 98 char answer[2]; 99 100 fd = socket_local_client( "qemud", 101 ANDROID_SOCKET_NAMESPACE_RESERVED, 102 SOCK_STREAM ); 103 if (fd < 0) { 104 D("no qemud control socket: %s", strerror(errno)); 105 return -1; 106 } 107 108 /* send service name to connect */ 109 if (qemu_fd_write(fd, name, namelen) != namelen) { 110 D("can't send service name to qemud: %s", 111 strerror(errno)); 112 close(fd); 113 return -1; 114 } 115 116 /* read answer from daemon */ 117 if (qemu_fd_read(fd, answer, 2) != 2 || 118 answer[0] != 'O' || answer[1] != 'K') { 119 D("cant' connect to %s service through qemud", name); 120 close(fd); 121 return -1; 122 } 123 124 channel->is_qemud = 1; 125 channel->fd = fd; 126 return 0; 127 } 128 129 130 static int 131 qemu_channel_open_qemud_old( QemuChannel* channel, 132 const char* name ) 133 { 134 int fd; 135 136 snprintf(channel->device, sizeof channel->device, 137 "qemud_%s", name); 138 139 fd = socket_local_client( channel->device, 140 ANDROID_SOCKET_NAMESPACE_RESERVED, 141 SOCK_STREAM ); 142 if (fd < 0) { 143 D("no '%s' control socket available: %s", 144 channel->device, strerror(errno)); 145 return -1; 146 } 147 148 close(fd); 149 channel->is_qemud_old = 1; 150 return 0; 151 } 152 153 154 static int 155 qemu_channel_open_tty( QemuChannel* channel, 156 const char* name, 157 int mode ) 158 { 159 char key[PROPERTY_KEY_MAX]; 160 char prop[PROPERTY_VALUE_MAX]; 161 int ret; 162 163 ret = snprintf(key, sizeof key, "ro.kernel.android.%s", name); 164 if (ret >= (int)sizeof key) 165 return -1; 166 167 if (property_get(key, prop, "") == 0) { 168 D("no kernel-provided %s device name", name); 169 return -1; 170 } 171 172 ret = snprintf(channel->device, sizeof channel->device, 173 "/dev/%s", prop); 174 if (ret >= (int)sizeof channel->device) { 175 D("%s device name too long: '%s'", name, prop); 176 return -1; 177 } 178 179 channel->is_tty = !memcmp("/dev/tty", channel->device, 8); 180 return 0; 181 } 182 183 int 184 qemu_channel_open( QemuChannel* channel, 185 const char* name, 186 int mode ) 187 { 188 int fd = -1; 189 190 /* initialize the channel is needed */ 191 if (!channel->is_inited) 192 { 193 channel->is_inited = 1; 194 195 do { 196 if (qemu_channel_open_qemud_pipe(channel, name) == 0) 197 break; 198 199 if (qemu_channel_open_qemud(channel, name) == 0) 200 break; 201 202 if (qemu_channel_open_qemud_old(channel, name) == 0) 203 break; 204 205 if (qemu_channel_open_tty(channel, name, mode) == 0) 206 break; 207 208 channel->is_available = 0; 209 return -1; 210 } while (0); 211 212 channel->is_available = 1; 213 } 214 215 /* try to open the file */ 216 if (!channel->is_available) { 217 errno = ENOENT; 218 return -1; 219 } 220 221 if (channel->is_qemud) { 222 return dup(channel->fd); 223 } 224 225 if (channel->is_qemud_old) { 226 do { 227 fd = socket_local_client( channel->device, 228 ANDROID_SOCKET_NAMESPACE_RESERVED, 229 SOCK_STREAM ); 230 } while (fd < 0 && errno == EINTR); 231 } 232 else /* /dev/ttySn ? */ 233 { 234 do { 235 fd = open(channel->device, mode); 236 } while (fd < 0 && errno == EINTR); 237 238 /* disable ECHO on serial lines */ 239 if (fd >= 0 && channel->is_tty) { 240 struct termios ios; 241 tcgetattr( fd, &ios ); 242 ios.c_lflag = 0; /* disable ECHO, ICANON, etc... */ 243 tcsetattr( fd, TCSANOW, &ios ); 244 } 245 } 246 return fd; 247 } 248 249 250 static int 251 qemu_command_vformat( char* buffer, 252 int buffer_size, 253 const char* format, 254 va_list args ) 255 { 256 char header[5]; 257 int len; 258 259 if (buffer_size < 6) 260 return -1; 261 262 len = vsnprintf(buffer+4, buffer_size-4, format, args); 263 if (len >= buffer_size-4) 264 return -1; 265 266 snprintf(header, sizeof header, "%04x", len); 267 memcpy(buffer, header, 4); 268 return len + 4; 269 } 270 271 extern int 272 qemu_command_format( char* buffer, 273 int buffer_size, 274 const char* format, 275 ... ) 276 { 277 va_list args; 278 int ret; 279 280 va_start(args, format); 281 ret = qemu_command_vformat(buffer, buffer_size, format, args); 282 va_end(args); 283 return ret; 284 } 285 286 287 static int 288 qemu_control_fd(void) 289 { 290 static QemuChannel channel[1]; 291 int fd; 292 293 fd = qemu_channel_open( channel, "hw-control", O_RDWR ); 294 if (fd < 0) { 295 D("%s: could not open control channel: %s", __FUNCTION__, 296 strerror(errno)); 297 } 298 return fd; 299 } 300 301 static int 302 qemu_control_send(const char* cmd, int len) 303 { 304 int fd, len2; 305 306 if (len < 0) { 307 errno = EINVAL; 308 return -1; 309 } 310 311 fd = qemu_control_fd(); 312 if (fd < 0) 313 return -1; 314 315 len2 = qemu_fd_write(fd, cmd, len); 316 close(fd); 317 if (len2 != len) { 318 D("%s: could not send everything %d < %d", 319 __FUNCTION__, len2, len); 320 return -1; 321 } 322 return 0; 323 } 324 325 326 int 327 qemu_control_command( const char* fmt, ... ) 328 { 329 va_list args; 330 char command[256]; 331 int len, fd; 332 333 va_start(args, fmt); 334 len = qemu_command_vformat( command, sizeof command, fmt, args ); 335 va_end(args); 336 337 if (len < 0 || len >= (int)sizeof command) { 338 if (len < 0) { 339 D("%s: could not send: %s", __FUNCTION__, strerror(errno)); 340 } else { 341 D("%s: too large %d > %d", __FUNCTION__, len, (int)(sizeof command)); 342 } 343 errno = EINVAL; 344 return -1; 345 } 346 347 return qemu_control_send( command, len ); 348 } 349 350 extern int qemu_control_query( const char* question, int questionlen, 351 char* answer, int answersize ) 352 { 353 int ret, fd, len, result = -1; 354 char header[5], *end; 355 356 if (questionlen <= 0) { 357 errno = EINVAL; 358 return -1; 359 } 360 361 fd = qemu_control_fd(); 362 if (fd < 0) 363 return -1; 364 365 ret = qemu_fd_write( fd, question, questionlen ); 366 if (ret != questionlen) { 367 D("%s: could not write all: %d < %d", __FUNCTION__, 368 ret, questionlen); 369 goto Exit; 370 } 371 372 /* read a 4-byte header giving the length of the following content */ 373 ret = qemu_fd_read( fd, header, 4 ); 374 if (ret != 4) { 375 D("%s: could not read header (%d != 4)", 376 __FUNCTION__, ret); 377 goto Exit; 378 } 379 380 header[4] = 0; 381 len = strtol( header, &end, 16 ); 382 if ( len < 0 || end == NULL || end != header+4 || len > answersize ) { 383 D("%s: could not parse header: '%s'", 384 __FUNCTION__, header); 385 goto Exit; 386 } 387 388 /* read the answer */ 389 ret = qemu_fd_read( fd, answer, len ); 390 if (ret != len) { 391 D("%s: could not read all of answer %d < %d", 392 __FUNCTION__, ret, len); 393 goto Exit; 394 } 395 396 result = len; 397 398 Exit: 399 close(fd); 400 return result; 401 } 402
