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/uio.h> 34 #include <sys/un.h> 35 #include <assert.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <unistd.h> 41 #include "un-namespace.h" 42 #include "nscachedcli.h" 43 44 #define NS_DEFAULT_CACHED_IO_TIMEOUT 4 45 46 static int safe_write(struct cached_connection_ *, const void *, size_t); 47 static int safe_read(struct cached_connection_ *, void *, size_t); 48 static int send_credentials(struct cached_connection_ *, int); 49 50 /* 51 * safe_write writes data to the specified connection and tries to do it in 52 * the very safe manner. We ensure, that we can write to the socket with 53 * kevent. If the data_size can't be sent in one piece, then it would be 54 * splitted. 55 */ 56 static int 57 safe_write(struct cached_connection_ *connection, const void *data, 58 size_t data_size) 59 { 60 struct kevent eventlist; 61 int nevents; 62 size_t result; 63 ssize_t s_result; 64 struct timespec timeout; 65 66 if (data_size == 0) 67 return (0); 68 69 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 70 timeout.tv_nsec = 0; 71 result = 0; 72 do { 73 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 74 1, &timeout); 75 if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) { 76 s_result = _write(connection->sockfd, 77 (char *)data + result, 78 eventlist.data < data_size - result ? 79 eventlist.data : data_size - result); 80 if (s_result == -1) 81 return (-1); 82 else 83 result += s_result; 84 85 if (eventlist.flags & EV_EOF) 86 return (result < data_size ? -1 : 0); 87 } else 88 return (-1); 89 } while (result < data_size); 90 91 return (0); 92 } 93 94 /* 95 * safe_read reads data from connection and tries to do it in the very safe 96 * and stable way. It uses kevent to ensure, that the data are availabe for 97 * reading. If the amount of data to be read is too large, then they would 98 * be splitted. 99 */ 100 static int 101 safe_read(struct cached_connection_ *connection, void *data, size_t data_size) 102 { 103 struct kevent eventlist; 104 size_t result; 105 ssize_t s_result; 106 struct timespec timeout; 107 int nevents; 108 109 if (data_size == 0) 110 return (0); 111 112 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 113 timeout.tv_nsec = 0; 114 result = 0; 115 do { 116 nevents = _kevent(connection->read_queue, NULL, 0, &eventlist, 117 1, &timeout); 118 if (nevents == 1 && eventlist.filter == EVFILT_READ) { 119 s_result = _read(connection->sockfd, 120 (char *)data + result, 121 eventlist.data <= data_size - result ? 122 eventlist.data : data_size - result); 123 if (s_result == -1) 124 return (-1); 125 else 126 result += s_result; 127 128 if (eventlist.flags & EV_EOF) 129 return (result < data_size ? -1 : 0); 130 } else 131 return (-1); 132 } while (result < data_size); 133 134 return (0); 135 } 136 137 /* 138 * Sends the credentials information to the connection along with the 139 * communication element type. 140 */ 141 static int 142 send_credentials(struct cached_connection_ *connection, int type) 143 { 144 struct kevent eventlist; 145 int nevents; 146 ssize_t result; 147 int res; 148 149 struct msghdr cred_hdr; 150 struct iovec iov; 151 152 struct { 153 struct cmsghdr hdr; 154 char cred[CMSG_SPACE(sizeof(struct cmsgcred))]; 155 } cmsg; 156 157 memset(&cmsg, 0, sizeof(cmsg)); 158 cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct cmsgcred)); 159 cmsg.hdr.cmsg_level = SOL_SOCKET; 160 cmsg.hdr.cmsg_type = SCM_CREDS; 161 162 memset(&cred_hdr, 0, sizeof(struct msghdr)); 163 cred_hdr.msg_iov = &iov; 164 cred_hdr.msg_iovlen = 1; 165 cred_hdr.msg_control = (caddr_t)&cmsg; 166 cred_hdr.msg_controllen = CMSG_SPACE(sizeof(struct cmsgcred)); 167 168 iov.iov_base = &type; 169 iov.iov_len = sizeof(int); 170 171 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD, 172 NOTE_LOWAT, sizeof(int), NULL); 173 res = _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL); 174 175 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 1, 176 NULL); 177 if (nevents == 1 && eventlist.filter == EVFILT_WRITE) { 178 result = (_sendmsg(connection->sockfd, &cred_hdr, 0) == -1) ? 179 -1 : 0; 180 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD, 181 0, 0, NULL); 182 _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL); 183 return (result); 184 } else 185 return (-1); 186 } 187 188 /* 189 * Opens the connection with the specified params. Initializes all kqueues. 190 */ 191 struct cached_connection_ * 192 __open_cached_connection(struct cached_connection_params const *params) 193 { 194 struct cached_connection_ *retval; 195 struct kevent eventlist; 196 struct sockaddr_un client_address; 197 int client_address_len, client_socket; 198 int res; 199 200 assert(params != NULL); 201 202 client_socket = _socket(PF_LOCAL, SOCK_STREAM, 0); 203 client_address.sun_family = PF_LOCAL; 204 strncpy(client_address.sun_path, params->socket_path, 205 sizeof(client_address.sun_path)); 206 client_address_len = sizeof(client_address.sun_family) + 207 strlen(client_address.sun_path) + 1; 208 209 res = _connect(client_socket, (struct sockaddr *)&client_address, 210 client_address_len); 211 if (res == -1) { 212 _close(client_socket); 213 return (NULL); 214 } 215 _fcntl(client_socket, F_SETFL, O_NONBLOCK); 216 217 retval = malloc(sizeof(struct cached_connection_)); 218 assert(retval != NULL); 219 memset(retval, 0, sizeof(struct cached_connection_)); 220 221 retval->sockfd = client_socket; 222 223 retval->write_queue = kqueue(); 224 assert(retval->write_queue != -1); 225 226 EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD, 0, 0, NULL); 227 res = _kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL); 228 229 retval->read_queue = kqueue(); 230 assert(retval->read_queue != -1); 231 232 EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD, 0, 0, NULL); 233 res = _kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL); 234 235 return (retval); 236 } 237 238 void 239 __close_cached_connection(struct cached_connection_ *connection) 240 { 241 assert(connection != NULL); 242 243 _close(connection->sockfd); 244 _close(connection->read_queue); 245 _close(connection->write_queue); 246 free(connection); 247 } 248 249 /* 250 * This function is very close to the cache_write function of the caching 251 * library, which is used in the caching daemon. It caches the data with the 252 * specified key in the cache entry with entry_name. 253 */ 254 int 255 __cached_write(struct cached_connection_ *connection, const char *entry_name, 256 const char *key, size_t key_size, const char *data, size_t data_size) 257 { 258 size_t name_size; 259 int error_code; 260 int result; 261 262 error_code = -1; 263 result = 0; 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; 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