1 /*- 2 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: src/lib/libc/net/nscachedcli.c,v 1.3 2006/12/04 17:08:43 ume Exp $ 27 */ 28 29 #include "namespace.h" 30 #include <sys/types.h> 31 #include <sys/socket.h> 32 #include <sys/event.h> 33 #include <sys/time.h> 34 #include <sys/uio.h> 35 #include <sys/un.h> 36 #include <assert.h> 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 #include "un-namespace.h" 43 #include "nscachedcli.h" 44 45 #define NS_DEFAULT_CACHED_IO_TIMEOUT 4 46 47 static int safe_write(struct cached_connection_ *, const void *, size_t); 48 static int safe_read(struct cached_connection_ *, void *, size_t); 49 static int send_credentials(struct cached_connection_ *, int); 50 51 /* 52 * safe_write writes data to the specified connection and tries to do it in 53 * the very safe manner. We ensure, that we can write to the socket with 54 * kevent. If the data_size can't be sent in one piece, then it would be 55 * splitted. 56 */ 57 static int 58 safe_write(struct cached_connection_ *connection, const void *data, 59 size_t data_size) 60 { 61 struct kevent eventlist; 62 int nevents; 63 size_t result; 64 ssize_t s_result; 65 struct timespec timeout; 66 67 if (data_size == 0) 68 return (0); 69 70 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 71 timeout.tv_nsec = 0; 72 result = 0; 73 do { 74 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 75 1, &timeout); 76 if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) { 77 s_result = _write(connection->sockfd, 78 (char *)data + result, 79 eventlist.data < data_size - result ? 80 eventlist.data : data_size - result); 81 if (s_result == -1) 82 return (-1); 83 else 84 result += s_result; 85 86 if (eventlist.flags & EV_EOF) 87 return (result < data_size ? -1 : 0); 88 } else 89 return (-1); 90 } while (result < data_size); 91 92 return (0); 93 } 94 95 /* 96 * safe_read reads data from connection and tries to do it in the very safe 97 * and stable way. It uses kevent to ensure, that the data are availabe for 98 * reading. If the amount of data to be read is too large, then they would 99 * be splitted. 100 */ 101 static int 102 safe_read(struct cached_connection_ *connection, void *data, size_t data_size) 103 { 104 struct kevent eventlist; 105 size_t result; 106 ssize_t s_result; 107 struct timespec timeout; 108 int nevents; 109 110 if (data_size == 0) 111 return (0); 112 113 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 114 timeout.tv_nsec = 0; 115 result = 0; 116 do { 117 nevents = _kevent(connection->read_queue, NULL, 0, &eventlist, 118 1, &timeout); 119 if (nevents == 1 && eventlist.filter == EVFILT_READ) { 120 s_result = _read(connection->sockfd, 121 (char *)data + result, 122 eventlist.data <= data_size - result ? 123 eventlist.data : data_size - result); 124 if (s_result == -1) 125 return (-1); 126 else 127 result += s_result; 128 129 if (eventlist.flags & EV_EOF) 130 return (result < data_size ? -1 : 0); 131 } else 132 return (-1); 133 } while (result < data_size); 134 135 return (0); 136 } 137 138 /* 139 * Sends the credentials information to the connection along with the 140 * communication element type. 141 */ 142 static int 143 send_credentials(struct cached_connection_ *connection, int type) 144 { 145 struct kevent eventlist; 146 int nevents; 147 ssize_t result; 148 int res __unused; 149 150 struct msghdr cred_hdr; 151 struct iovec iov; 152 153 struct { 154 struct cmsghdr hdr; 155 char cred[CMSG_SPACE(sizeof(struct cmsgcred))]; 156 } cmsg; 157 158 memset(&cmsg, 0, sizeof(cmsg)); 159 cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct cmsgcred)); 160 cmsg.hdr.cmsg_level = SOL_SOCKET; 161 cmsg.hdr.cmsg_type = SCM_CREDS; 162 163 memset(&cred_hdr, 0, sizeof(struct msghdr)); 164 cred_hdr.msg_iov = &iov; 165 cred_hdr.msg_iovlen = 1; 166 cred_hdr.msg_control = (caddr_t)&cmsg; 167 cred_hdr.msg_controllen = CMSG_SPACE(sizeof(struct cmsgcred)); 168 169 iov.iov_base = &type; 170 iov.iov_len = sizeof(int); 171 172 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD, 173 NOTE_LOWAT, sizeof(int), NULL); 174 res = _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL); 175 176 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 1, 177 NULL); 178 if (nevents == 1 && eventlist.filter == EVFILT_WRITE) { 179 result = (_sendmsg(connection->sockfd, &cred_hdr, 0) == -1) ? 180 -1 : 0; 181 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD, 182 0, 0, NULL); 183 _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL); 184 return (result); 185 } else 186 return (-1); 187 } 188 189 /* 190 * Opens the connection with the specified params. Initializes all kqueues. 191 */ 192 struct cached_connection_ * 193 __open_cached_connection(struct cached_connection_params const *params) 194 { 195 struct cached_connection_ *retval; 196 struct kevent eventlist; 197 struct sockaddr_un client_address; 198 int client_address_len, client_socket; 199 int res; 200 201 assert(params != NULL); 202 203 client_socket = _socket(PF_LOCAL, SOCK_STREAM, 0); 204 client_address.sun_family = PF_LOCAL; 205 strncpy(client_address.sun_path, params->socket_path, 206 sizeof(client_address.sun_path)); 207 client_address_len = sizeof(client_address.sun_family) + 208 strlen(client_address.sun_path) + 1; 209 210 res = _connect(client_socket, (struct sockaddr *)&client_address, 211 client_address_len); 212 if (res == -1) { 213 _close(client_socket); 214 return (NULL); 215 } 216 _fcntl(client_socket, F_SETFL, O_NONBLOCK); 217 218 retval = malloc(sizeof(struct cached_connection_)); 219 assert(retval != NULL); 220 memset(retval, 0, sizeof(struct cached_connection_)); 221 222 retval->sockfd = client_socket; 223 224 retval->write_queue = kqueue(); 225 assert(retval->write_queue != -1); 226 227 EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD, 0, 0, NULL); 228 res = _kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL); 229 230 retval->read_queue = kqueue(); 231 assert(retval->read_queue != -1); 232 233 EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD, 0, 0, NULL); 234 res = _kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL); 235 236 return (retval); 237 } 238 239 void 240 __close_cached_connection(struct cached_connection_ *connection) 241 { 242 assert(connection != NULL); 243 244 _close(connection->sockfd); 245 _close(connection->read_queue); 246 _close(connection->write_queue); 247 free(connection); 248 } 249 250 /* 251 * This function is very close to the cache_write function of the caching 252 * library, which is used in the caching daemon. It caches the data with the 253 * specified key in the cache entry with entry_name. 254 */ 255 int 256 __cached_write(struct cached_connection_ *connection, const char *entry_name, 257 const char *key, size_t key_size, const char *data, size_t data_size) 258 { 259 size_t name_size; 260 int error_code; 261 int result; 262 263 error_code = -1; 264 result = send_credentials(connection, CET_WRITE_REQUEST); 265 if (result != 0) 266 goto fin; 267 268 name_size = strlen(entry_name); 269 result = safe_write(connection, &name_size, sizeof(size_t)); 270 if (result != 0) 271 goto fin; 272 273 result = safe_write(connection, &key_size, sizeof(size_t)); 274 if (result != 0) 275 goto fin; 276 277 result = safe_write(connection, &data_size, sizeof(size_t)); 278 if (result != 0) 279 goto fin; 280 281 result = safe_write(connection, entry_name, name_size); 282 if (result != 0) 283 goto fin; 284 285 result = safe_write(connection, key, key_size); 286 if (result != 0) 287 goto fin; 288 289 result = safe_write(connection, data, data_size); 290 if (result != 0) 291 goto fin; 292 293 result = safe_read(connection, &error_code, sizeof(int)); 294 if (result != 0) 295 error_code = -1; 296 297 fin: 298 return (error_code); 299 } 300 301 /* 302 * This function is very close to the cache_read function of the caching 303 * library, which is used in the caching daemon. It reads cached data with the 304 * specified key from the cache entry with entry_name. 305 */ 306 int 307 __cached_read(struct cached_connection_ *connection, const char *entry_name, 308 const char *key, size_t key_size, char *data, size_t *data_size) 309 { 310 size_t name_size, result_size; 311 int error_code, rec_error_code; 312 int result; 313 314 assert(connection != NULL); 315 result = 0; 316 error_code = -1; 317 318 result = send_credentials(connection, CET_READ_REQUEST); 319 if (result != 0) 320 goto fin; 321 322 name_size = strlen(entry_name); 323 result = safe_write(connection, &name_size, sizeof(size_t)); 324 if (result != 0) 325 goto fin; 326 327 result = safe_write(connection, &key_size, sizeof(size_t)); 328 if (result != 0) 329 goto fin; 330 331 result = safe_write(connection, entry_name, name_size); 332 if (result != 0) 333 goto fin; 334 335 result = safe_write(connection, key, key_size); 336 if (result != 0) 337 goto fin; 338 339 result = safe_read(connection, &rec_error_code, sizeof(int)); 340 if (result != 0) 341 goto fin; 342 343 if (rec_error_code != 0) { 344 error_code = rec_error_code; 345 goto fin; 346 } 347 348 result = safe_read(connection, &result_size, sizeof(size_t)); 349 if (result != 0) 350 goto fin; 351 352 if (result_size > *data_size) { 353 *data_size = result_size; 354 error_code = -2; 355 goto fin; 356 } 357 358 result = safe_read(connection, data, result_size); 359 if (result != 0) 360 goto fin; 361 362 *data_size = result_size; 363 error_code = 0; 364 365 fin: 366 return (error_code); 367 } 368 369 /* 370 * Initializes the mp_write_session. For such a session the new connection 371 * would be opened. The data should be written to the session with 372 * __cached_mp_write function. The __close_cached_mp_write_session function 373 * should be used to submit session and __abandon_cached_mp_write_session - to 374 * abandon it. When the session is submitted, the whole se 375 */ 376 struct cached_connection_ * 377 __open_cached_mp_write_session(struct cached_connection_params const *params, 378 const char *entry_name) 379 { 380 struct cached_connection_ *connection, *retval; 381 size_t name_size; 382 int error_code; 383 int result; 384 385 retval = NULL; 386 connection = __open_cached_connection(params); 387 if (connection == NULL) 388 return (NULL); 389 connection->mp_flag = 1; 390 391 result = send_credentials(connection, CET_MP_WRITE_SESSION_REQUEST); 392 if (result != 0) 393 goto fin; 394 395 name_size = strlen(entry_name); 396 result = safe_write(connection, &name_size, sizeof(size_t)); 397 if (result != 0) 398 goto fin; 399 400 result = safe_write(connection, entry_name, name_size); 401 if (result != 0) 402 goto fin; 403 404 result = safe_read(connection, &error_code, sizeof(int)); 405 if (result != 0) 406 goto fin; 407 408 if (error_code != 0) 409 result = error_code; 410 411 fin: 412 if (result != 0) 413 __close_cached_connection(connection); 414 else 415 retval = connection; 416 return (retval); 417 } 418 419 /* 420 * Adds new portion of data to the opened write session 421 */ 422 int 423 __cached_mp_write(struct cached_connection_ *ws, const char *data, 424 size_t data_size) 425 { 426 int request, result; 427 int error_code; 428 429 error_code = -1; 430 431 request = CET_MP_WRITE_SESSION_WRITE_REQUEST; 432 result = safe_write(ws, &request, sizeof(int)); 433 if (result != 0) 434 goto fin; 435 436 result = safe_write(ws, &data_size, sizeof(size_t)); 437 if (result != 0) 438 goto fin; 439 440 result = safe_write(ws, data, data_size); 441 if (result != 0) 442 goto fin; 443 444 result = safe_read(ws, &error_code, sizeof(int)); 445 if (result != 0) 446 error_code = -1; 447 448 fin: 449 return (error_code); 450 } 451 452 /* 453 * Abandons all operations with the write session. All data, that were written 454 * to the session before, are discarded. 455 */ 456 int 457 __abandon_cached_mp_write_session(struct cached_connection_ *ws) 458 { 459 int notification; 460 int result; 461 462 notification = CET_MP_WRITE_SESSION_ABANDON_NOTIFICATION; 463 result = safe_write(ws, ¬ification, sizeof(int)); 464 __close_cached_connection(ws); 465 return (result); 466 } 467 468 /* 469 * Gracefully closes the write session. The data, that were previously written 470 * to the session, are committed. 471 */ 472 int 473 __close_cached_mp_write_session(struct cached_connection_ *ws) 474 { 475 int notification; 476 int result __unused; 477 478 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION; 479 result = safe_write(ws, ¬ification, sizeof(int)); 480 __close_cached_connection(ws); 481 return (0); 482 } 483 484 struct cached_connection_ * 485 __open_cached_mp_read_session(struct cached_connection_params const *params, 486 const char *entry_name) 487 { 488 struct cached_connection_ *connection, *retval; 489 size_t name_size; 490 int error_code; 491 int result; 492 493 retval = NULL; 494 connection = __open_cached_connection(params); 495 if (connection == NULL) 496 return (NULL); 497 connection->mp_flag = 1; 498 499 result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST); 500 if (result != 0) 501 goto fin; 502 503 name_size = strlen(entry_name); 504 result = safe_write(connection, &name_size, sizeof(size_t)); 505 if (result != 0) 506 goto fin; 507 508 result = safe_write(connection, entry_name, name_size); 509 if (result != 0) 510 goto fin; 511 512 result = safe_read(connection, &error_code, sizeof(int)); 513 if (result != 0) 514 goto fin; 515 516 if (error_code != 0) 517 result = error_code; 518 519 fin: 520 if (result != 0) 521 __close_cached_connection(connection); 522 else 523 retval = connection; 524 return (retval); 525 } 526 527 int 528 __cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size) 529 { 530 size_t result_size; 531 int error_code, rec_error_code; 532 int request, result; 533 534 error_code = -1; 535 request = CET_MP_READ_SESSION_READ_REQUEST; 536 result = safe_write(rs, &request, sizeof(int)); 537 if (result != 0) 538 goto fin; 539 540 result = safe_read(rs, &rec_error_code, sizeof(int)); 541 if (result != 0) 542 goto fin; 543 544 if (rec_error_code != 0) { 545 error_code = rec_error_code; 546 goto fin; 547 } 548 549 result = safe_read(rs, &result_size, sizeof(size_t)); 550 if (result != 0) 551 goto fin; 552 553 if (result_size > *data_size) { 554 *data_size = result_size; 555 error_code = -2; 556 goto fin; 557 } 558 559 result = safe_read(rs, data, result_size); 560 if (result != 0) 561 goto fin; 562 563 *data_size = result_size; 564 error_code = 0; 565 566 fin: 567 return (error_code); 568 } 569 570 int 571 __close_cached_mp_read_session(struct cached_connection_ *rs) 572 { 573 574 __close_cached_connection(rs); 575 return (0); 576 } 577