The Android Open Source Project | 52d4c30 | 2009-03-03 19:29:09 -0800 | [diff] [blame] | 1 | // |
| 2 | // Copyright 2005 The Android Open Source Project |
| 3 | // |
| 4 | // Local named bi-directional communication channel. |
| 5 | // |
| 6 | #include "LocalBiChannel.h" |
| 7 | #include "utils/Log.h" |
| 8 | |
| 9 | #if defined(HAVE_WIN32_IPC) |
| 10 | # define _WIN32_WINNT 0x0500 |
| 11 | # include <windows.h> |
| 12 | #else |
| 13 | # include <sys/types.h> |
| 14 | # include <sys/socket.h> |
| 15 | # include <sys/stat.h> |
| 16 | # include <sys/un.h> |
| 17 | #endif |
| 18 | |
| 19 | #include <stdlib.h> |
| 20 | #include <unistd.h> |
| 21 | #include <string.h> |
| 22 | #include <errno.h> |
| 23 | #include <assert.h> |
| 24 | |
| 25 | #ifndef SUN_LEN |
| 26 | /* |
| 27 | * Our current set of ARM header files don't define this. |
| 28 | */ |
| 29 | # define SUN_LEN(ptr) ((size_t) (((struct sockaddr_un *) 0)->sun_path) \ |
| 30 | + strlen ((ptr)->sun_path)) |
| 31 | #endif |
| 32 | |
| 33 | using namespace android; |
| 34 | |
| 35 | const unsigned long kInvalidHandle = (unsigned long) -1; |
| 36 | |
| 37 | /* |
| 38 | * Initialize data fields. |
| 39 | */ |
| 40 | LocalBiChannel::LocalBiChannel(void) |
| 41 | : mFileName(NULL), mIsListener(false), mHandle(kInvalidHandle) |
| 42 | { |
| 43 | } |
| 44 | |
| 45 | #if defined(HAVE_WIN32_IPC) |
| 46 | /* |
| 47 | * Implementation for Win32, using named pipes. |
| 48 | * |
| 49 | * Cygwin actually supports UNIX-domain sockets, but we want to stuff |
| 50 | * the file handles into a Pipe, which uses HANDLE under Win32. |
| 51 | */ |
| 52 | |
| 53 | const int kPipeSize = 4096; |
| 54 | |
| 55 | /* |
| 56 | * Destructor. If we're the server side, we may need to clean up after |
| 57 | * ourselves. |
| 58 | */ |
| 59 | LocalBiChannel::~LocalBiChannel(void) |
| 60 | { |
| 61 | if (mHandle != kInvalidHandle) |
| 62 | CloseHandle((HANDLE)mHandle); |
| 63 | |
| 64 | delete[] mFileName; |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * Construct the full path. The caller must delete[] the return value. |
| 69 | */ |
| 70 | static char* makeFilename(const char* name) |
| 71 | { |
| 72 | static const char* kBasePath = "\\\\.\\pipe\\android-"; |
| 73 | char* fileName; |
| 74 | |
| 75 | assert(name != NULL && name[0] != '\0'); |
| 76 | |
| 77 | fileName = new char[strlen(kBasePath) + strlen(name) + 1]; |
| 78 | strcpy(fileName, kBasePath); |
| 79 | strcat(fileName, name); |
| 80 | |
| 81 | return fileName; |
| 82 | } |
| 83 | |
| 84 | /* |
| 85 | * Create a named pipe, so the client has something to connect to. |
| 86 | */ |
| 87 | bool LocalBiChannel::create(const char* name) |
| 88 | { |
| 89 | delete[] mFileName; |
| 90 | mFileName = makeFilename(name); |
| 91 | |
| 92 | #if 0 |
| 93 | HANDLE hPipe; |
| 94 | |
| 95 | hPipe = CreateNamedPipe( |
| 96 | mFileName, // unique pipe name |
| 97 | PIPE_ACCESS_DUPLEX | // open mode |
| 98 | FILE_FLAG_FIRST_PIPE_INSTANCE, |
| 99 | 0, // pipe mode (byte, blocking) |
| 100 | 1, // max instances |
| 101 | kPipeSize, // output buffer |
| 102 | kPipeSize, // input buffer |
| 103 | NMPWAIT_USE_DEFAULT_WAIT, // client time-out |
| 104 | NULL); // security |
| 105 | |
| 106 | if (hPipe == 0) { |
| 107 | LOG(LOG_ERROR, "lbicomm", |
| 108 | "CreateNamedPipe failed (err=%ld)\n", GetLastError()); |
| 109 | return false; |
| 110 | } |
| 111 | |
| 112 | mHandle = (unsigned long) hPipe; |
| 113 | #endif |
| 114 | |
| 115 | return true; |
| 116 | } |
| 117 | |
| 118 | /* |
| 119 | * Attach to an existing named pipe. |
| 120 | */ |
| 121 | bool LocalBiChannel::attach(const char* name, Pipe** ppReadPipe, |
| 122 | Pipe** ppWritePipe) |
| 123 | { |
| 124 | HANDLE hPipe, dupHandle; |
| 125 | |
| 126 | delete[] mFileName; |
| 127 | mFileName = makeFilename(name); |
| 128 | |
| 129 | hPipe = CreateFile( |
| 130 | mFileName, // filename |
| 131 | GENERIC_READ | GENERIC_WRITE, // access |
| 132 | 0, // no sharing |
| 133 | NULL, // security |
| 134 | OPEN_EXISTING, // don't create |
| 135 | 0, // attributes |
| 136 | NULL); // template |
| 137 | if (hPipe == INVALID_HANDLE_VALUE) { |
| 138 | LOG(LOG_ERROR, "lbicomm", |
| 139 | "CreateFile on pipe '%s' failed (err=%ld)\n", name, GetLastError()); |
| 140 | return false; |
| 141 | } |
| 142 | |
| 143 | assert(mHandle == kInvalidHandle); |
| 144 | |
| 145 | /* |
| 146 | * Set up the pipes. Use the new handle for one, and a duplicate |
| 147 | * of it for the other, in case we decide to only close one side. |
| 148 | */ |
| 149 | *ppReadPipe = new Pipe(); |
| 150 | (*ppReadPipe)->createReader((unsigned long) hPipe); |
| 151 | |
| 152 | DuplicateHandle( |
| 153 | GetCurrentProcess(), |
| 154 | hPipe, |
| 155 | GetCurrentProcess(), |
| 156 | &dupHandle, |
| 157 | 0, |
| 158 | FALSE, |
| 159 | DUPLICATE_SAME_ACCESS); |
| 160 | *ppWritePipe = new Pipe(); |
| 161 | (*ppWritePipe)->createWriter((unsigned long) dupHandle); |
| 162 | |
| 163 | return true; |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * Listen for a new connection, discarding any existing connection. |
| 168 | */ |
| 169 | bool LocalBiChannel::listen(Pipe** ppReadPipe, Pipe** ppWritePipe) |
| 170 | { |
| 171 | BOOL connected; |
| 172 | HANDLE hPipe; |
| 173 | |
| 174 | /* |
| 175 | * Create up to 3 instances of the named pipe: |
| 176 | * - currently active connection |
| 177 | * - connection currently being rejected because one is already active |
| 178 | * - a new listener to wait for the next round |
| 179 | */ |
| 180 | hPipe = CreateNamedPipe( |
| 181 | mFileName, // unique pipe name |
| 182 | PIPE_ACCESS_DUPLEX // open mode |
| 183 | /*| FILE_FLAG_FIRST_PIPE_INSTANCE*/, |
| 184 | 0, // pipe mode (byte, blocking) |
| 185 | 3, // max instances |
| 186 | kPipeSize, // output buffer |
| 187 | kPipeSize, // input buffer |
| 188 | NMPWAIT_USE_DEFAULT_WAIT, // client time-out |
| 189 | NULL); // security |
| 190 | |
| 191 | if (hPipe == 0) { |
| 192 | LOG(LOG_ERROR, "lbicomm", |
| 193 | "CreateNamedPipe failed (err=%ld)\n", GetLastError()); |
| 194 | return false; |
| 195 | } |
| 196 | |
| 197 | /* |
| 198 | * If a client is already connected to us, this fails with |
| 199 | * ERROR_PIPE_CONNECTED. It returns success if we had to wait |
| 200 | * a little bit before the connection happens. |
| 201 | */ |
| 202 | connected = ConnectNamedPipe(hPipe, NULL) ? |
| 203 | TRUE : (GetLastError() == ERROR_PIPE_CONNECTED); |
| 204 | |
| 205 | if (connected) { |
| 206 | /* |
| 207 | * Create the pipes. Give one a duplicated handle so that, |
| 208 | * when one closes, we don't lose both. |
| 209 | */ |
| 210 | HANDLE dupHandle; |
| 211 | |
| 212 | *ppReadPipe = new Pipe(); |
| 213 | (*ppReadPipe)->createReader((unsigned long) hPipe); |
| 214 | |
| 215 | DuplicateHandle( |
| 216 | GetCurrentProcess(), |
| 217 | hPipe, |
| 218 | GetCurrentProcess(), |
| 219 | &dupHandle, |
| 220 | 0, |
| 221 | FALSE, |
| 222 | DUPLICATE_SAME_ACCESS); |
| 223 | *ppWritePipe = new Pipe(); |
| 224 | (*ppWritePipe)->createWriter((unsigned long) dupHandle); |
| 225 | |
| 226 | return true; |
| 227 | } else { |
| 228 | LOG(LOG_WARN, "lbicomm", |
| 229 | "ConnectNamedPipe failed (err=%ld)\n", GetLastError()); |
| 230 | #ifdef HAVE_WIN32_THREADS |
| 231 | Sleep(500); /* 500 ms */ |
| 232 | #else |
| 233 | usleep(500000); // DEBUG DEBUG |
| 234 | #endif |
| 235 | return false; |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | #else |
| 240 | |
| 241 | /* |
| 242 | * Implementation for Linux and Darwin, using UNIX-domain sockets. |
| 243 | */ |
| 244 | |
| 245 | /* |
| 246 | * Destructor. If we're the server side, blow away the socket file. |
| 247 | */ |
| 248 | LocalBiChannel::~LocalBiChannel(void) |
| 249 | { |
| 250 | if (mHandle != kInvalidHandle) |
| 251 | close((int) mHandle); |
| 252 | |
| 253 | if (mIsListener && mFileName != NULL) { |
| 254 | LOG(LOG_DEBUG, "lbicomm", "Removing '%s'\n", mFileName); |
| 255 | (void) unlink(mFileName); |
| 256 | } |
| 257 | delete[] mFileName; |
| 258 | } |
| 259 | |
| 260 | /* |
| 261 | * Construct the full path. The caller must delete[] the return value. |
| 262 | */ |
| 263 | static char* makeFilename(const char* name) |
| 264 | { |
| 265 | static const char* kBasePath = "/tmp/android-"; |
| 266 | char* fileName; |
| 267 | |
| 268 | assert(name != NULL && name[0] != '\0'); |
| 269 | |
| 270 | fileName = new char[strlen(kBasePath) + strlen(name) + 1]; |
| 271 | strcpy(fileName, kBasePath); |
| 272 | strcat(fileName, name); |
| 273 | |
| 274 | return fileName; |
| 275 | } |
| 276 | |
| 277 | /* |
| 278 | * Create a UNIX domain socket, carefully removing it if it already |
| 279 | * exists. |
| 280 | */ |
| 281 | bool LocalBiChannel::create(const char* name) |
| 282 | { |
| 283 | struct stat sb; |
| 284 | bool result = false; |
| 285 | int sock = -1; |
| 286 | int cc; |
| 287 | |
| 288 | delete[] mFileName; |
| 289 | mFileName = makeFilename(name); |
| 290 | |
| 291 | cc = stat(mFileName, &sb); |
| 292 | if (cc < 0) { |
| 293 | if (errno != ENOENT) { |
| 294 | LOG(LOG_ERROR, "lbicomm", |
| 295 | "Unable to stat '%s' (errno=%d)\n", mFileName, errno); |
| 296 | goto bail; |
| 297 | } |
| 298 | } else { |
| 299 | /* don't touch it if it's not a socket */ |
| 300 | if (!(S_ISSOCK(sb.st_mode))) { |
| 301 | LOG(LOG_ERROR, "lbicomm", |
| 302 | "File '%s' exists and is not a socket\n", mFileName); |
| 303 | goto bail; |
| 304 | } |
| 305 | |
| 306 | /* remove the cruft */ |
| 307 | if (unlink(mFileName) < 0) { |
| 308 | LOG(LOG_ERROR, "lbicomm", |
| 309 | "Unable to remove '%s' (errno=%d)\n", mFileName, errno); |
| 310 | goto bail; |
| 311 | } |
| 312 | } |
| 313 | |
| 314 | struct sockaddr_un addr; |
| 315 | |
| 316 | sock = ::socket(AF_UNIX, SOCK_STREAM, 0); |
| 317 | if (sock < 0) { |
| 318 | LOG(LOG_ERROR, "lbicomm", |
| 319 | "UNIX domain socket create failed (errno=%d)\n", errno); |
| 320 | goto bail; |
| 321 | } |
| 322 | |
| 323 | /* bind the socket; this creates the file on disk */ |
| 324 | strcpy(addr.sun_path, mFileName); // max 108 bytes |
| 325 | addr.sun_family = AF_UNIX; |
| 326 | cc = ::bind(sock, (struct sockaddr*) &addr, SUN_LEN(&addr)); |
| 327 | if (cc < 0) { |
| 328 | LOG(LOG_ERROR, "lbicomm", |
| 329 | "AF_UNIX bind failed for '%s' (errno=%d)\n", mFileName, errno); |
| 330 | goto bail; |
| 331 | } |
| 332 | |
| 333 | mHandle = (unsigned long) sock; |
| 334 | sock = -1; |
| 335 | mIsListener = true; |
| 336 | result = true; |
| 337 | |
| 338 | bail: |
| 339 | if (sock >= 0) |
| 340 | close(sock); |
| 341 | return result; |
| 342 | } |
| 343 | |
| 344 | /* |
| 345 | * Attach to an existing UNIX domain socket. |
| 346 | */ |
| 347 | bool LocalBiChannel::attach(const char* name, Pipe** ppReadPipe, |
| 348 | Pipe** ppWritePipe) |
| 349 | { |
| 350 | bool result = false; |
| 351 | int sock = -1; |
| 352 | int cc; |
| 353 | |
| 354 | assert(ppReadPipe != NULL); |
| 355 | assert(ppWritePipe != NULL); |
| 356 | |
| 357 | delete[] mFileName; |
| 358 | mFileName = makeFilename(name); |
| 359 | |
| 360 | struct sockaddr_un addr; |
| 361 | |
| 362 | sock = ::socket(AF_UNIX, SOCK_STREAM, 0); |
| 363 | if (sock < 0) { |
| 364 | LOG(LOG_ERROR, "lbicomm", |
| 365 | "UNIX domain socket create failed (errno=%d)\n", errno); |
| 366 | goto bail; |
| 367 | } |
| 368 | |
| 369 | /* connect to socket; fails if file doesn't exist */ |
| 370 | strcpy(addr.sun_path, mFileName); // max 108 bytes |
| 371 | addr.sun_family = AF_UNIX; |
| 372 | cc = ::connect(sock, (struct sockaddr*) &addr, SUN_LEN(&addr)); |
| 373 | if (cc < 0) { |
| 374 | // ENOENT means socket file doesn't exist |
| 375 | // ECONNREFUSED means socket exists but nobody is listening |
| 376 | LOG(LOG_ERROR, "lbicomm", |
| 377 | "AF_UNIX connect failed for '%s': %s\n", mFileName,strerror(errno)); |
| 378 | goto bail; |
| 379 | } |
| 380 | |
| 381 | /* |
| 382 | * Create the two halves. We dup() the sock so that closing one side |
| 383 | * does not hose the other. |
| 384 | */ |
| 385 | *ppReadPipe = new Pipe(); |
| 386 | (*ppReadPipe)->createReader(sock); |
| 387 | *ppWritePipe = new Pipe(); |
| 388 | (*ppWritePipe)->createWriter(dup(sock)); |
| 389 | |
| 390 | assert(mHandle == kInvalidHandle); |
| 391 | sock = -1; |
| 392 | mIsListener = false; |
| 393 | |
| 394 | result = true; |
| 395 | |
| 396 | bail: |
| 397 | if (sock >= 0) |
| 398 | close(sock); |
| 399 | return result; |
| 400 | } |
| 401 | |
| 402 | /* |
| 403 | * Listen for a new connection. |
| 404 | */ |
| 405 | bool LocalBiChannel::listen(Pipe** ppReadPipe, Pipe** ppWritePipe) |
| 406 | { |
| 407 | bool result = false; |
| 408 | struct sockaddr_un from; |
| 409 | socklen_t fromlen; |
| 410 | int sock, lsock; |
| 411 | int cc; |
| 412 | |
| 413 | assert(mHandle != kInvalidHandle); |
| 414 | lsock = (int) mHandle; |
| 415 | |
| 416 | LOG(LOG_DEBUG, "lbicomm", "AF_UNIX listening\n"); |
| 417 | cc = ::listen(lsock, 5); |
| 418 | if (cc < 0) { |
| 419 | LOG(LOG_ERROR, "lbicomm", "AF_UNIX listen failed (errno=%d)\n", errno); |
| 420 | goto bail; |
| 421 | } |
| 422 | |
| 423 | fromlen = sizeof(from); // not SUN_LEN() |
| 424 | sock = ::accept(lsock, (struct sockaddr*) &from, &fromlen); |
| 425 | if (sock < 0) { |
| 426 | LOG(LOG_WARN, "lbicomm", "AF_UNIX accept failed (errno=%d)\n", errno); |
| 427 | goto bail; |
| 428 | } |
| 429 | |
| 430 | /* |
| 431 | * Create the two halves. We dup() the sock so that closing one side |
| 432 | * does not hose the other. |
| 433 | */ |
| 434 | *ppReadPipe = new Pipe(); |
| 435 | (*ppReadPipe)->createReader(sock); |
| 436 | *ppWritePipe = new Pipe(); |
| 437 | (*ppWritePipe)->createWriter(dup(sock)); |
| 438 | result = true; |
| 439 | |
| 440 | bail: |
| 441 | return result; |
| 442 | } |
| 443 | |
| 444 | #endif |