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 __unused; 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 = send_credentials(connection, CET_WRITE_REQUEST); 264 if (result != 0) 265 goto fin; 266 267 name_size = strlen(entry_name); 268 result = safe_write(connection, &name_size, sizeof(size_t)); 269 if (result != 0) 270 goto fin; 271 272 result = safe_write(connection, &key_size, sizeof(size_t)); 273 if (result != 0) 274 goto fin; 275 276 result = safe_write(connection, &data_size, sizeof(size_t)); 277 if (result != 0) 278 goto fin; 279 280 result = safe_write(connection, entry_name, name_size); 281 if (result != 0) 282 goto fin; 283 284 result = safe_write(connection, key, key_size); 285 if (result != 0) 286 goto fin; 287 288 result = safe_write(connection, data, data_size); 289 if (result != 0) 290 goto fin; 291 292 result = safe_read(connection, &error_code, sizeof(int)); 293 if (result != 0) 294 error_code = -1; 295 296 fin: 297 return (error_code); 298 } 299 300 /* 301 * This function is very close to the cache_read function of the caching 302 * library, which is used in the caching daemon. It reads cached data with the 303 * specified key from the cache entry with entry_name. 304 */ 305 int 306 __cached_read(struct cached_connection_ *connection, const char *entry_name, 307 const char *key, size_t key_size, char *data, size_t *data_size) 308 { 309 size_t name_size, result_size; 310 int error_code, rec_error_code; 311 int result; 312 313 assert(connection != NULL); 314 result = 0; 315 error_code = -1; 316 317 result = send_credentials(connection, CET_READ_REQUEST); 318 if (result != 0) 319 goto fin; 320 321 name_size = strlen(entry_name); 322 result = safe_write(connection, &name_size, sizeof(size_t)); 323 if (result != 0) 324 goto fin; 325 326 result = safe_write(connection, &key_size, sizeof(size_t)); 327 if (result != 0) 328 goto fin; 329 330 result = safe_write(connection, entry_name, name_size); 331 if (result != 0) 332 goto fin; 333 334 result = safe_write(connection, key, key_size); 335 if (result != 0) 336 goto fin; 337 338 result = safe_read(connection, &rec_error_code, sizeof(int)); 339 if (result != 0) 340 goto fin; 341 342 if (rec_error_code != 0) { 343 error_code = rec_error_code; 344 goto fin; 345 } 346 347 result = safe_read(connection, &result_size, sizeof(size_t)); 348 if (result != 0) 349 goto fin; 350 351 if (result_size > *data_size) { 352 *data_size = result_size; 353 error_code = -2; 354 goto fin; 355 } 356 357 result = safe_read(connection, data, result_size); 358 if (result != 0) 359 goto fin; 360 361 *data_size = result_size; 362 error_code = 0; 363 364 fin: 365 return (error_code); 366 } 367 368 /* 369 * Initializes the mp_write_session. For such a session the new connection 370 * would be opened. The data should be written to the session with 371 * __cached_mp_write function. The __close_cached_mp_write_session function 372 * should be used to submit session and __abandon_cached_mp_write_session - to 373 * abandon it. When the session is submitted, the whole se 374 */ 375 struct cached_connection_ * 376 __open_cached_mp_write_session(struct cached_connection_params const *params, 377 const char *entry_name) 378 { 379 struct cached_connection_ *connection, *retval; 380 size_t name_size; 381 int error_code; 382 int result; 383 384 retval = NULL; 385 connection = __open_cached_connection(params); 386 if (connection == NULL) 387 return (NULL); 388 connection->mp_flag = 1; 389 390 result = send_credentials(connection, CET_MP_WRITE_SESSION_REQUEST); 391 if (result != 0) 392 goto fin; 393 394 name_size = strlen(entry_name); 395 result = safe_write(connection, &name_size, sizeof(size_t)); 396 if (result != 0) 397 goto fin; 398 399 result = safe_write(connection, entry_name, name_size); 400 if (result != 0) 401 goto fin; 402 403 result = safe_read(connection, &error_code, sizeof(int)); 404 if (result != 0) 405 goto fin; 406 407 if (error_code != 0) 408 result = error_code; 409 410 fin: 411 if (result != 0) 412 __close_cached_connection(connection); 413 else 414 retval = connection; 415 return (retval); 416 } 417 418 /* 419 * Adds new portion of data to the opened write session 420 */ 421 int 422 __cached_mp_write(struct cached_connection_ *ws, const char *data, 423 size_t data_size) 424 { 425 int request, result; 426 int error_code; 427 428 error_code = -1; 429 430 request = CET_MP_WRITE_SESSION_WRITE_REQUEST; 431 result = safe_write(ws, &request, sizeof(int)); 432 if (result != 0) 433 goto fin; 434 435 result = safe_write(ws, &data_size, sizeof(size_t)); 436 if (result != 0) 437 goto fin; 438 439 result = safe_write(ws, data, data_size); 440 if (result != 0) 441 goto fin; 442 443 result = safe_read(ws, &error_code, sizeof(int)); 444 if (result != 0) 445 error_code = -1; 446 447 fin: 448 return (error_code); 449 } 450 451 /* 452 * Abandons all operations with the write session. All data, that were written 453 * to the session before, are discarded. 454 */ 455 int 456 __abandon_cached_mp_write_session(struct cached_connection_ *ws) 457 { 458 int notification; 459 int result; 460 461 notification = CET_MP_WRITE_SESSION_ABANDON_NOTIFICATION; 462 result = safe_write(ws, ¬ification, sizeof(int)); 463 __close_cached_connection(ws); 464 return (result); 465 } 466 467 /* 468 * Gracefully closes the write session. The data, that were previously written 469 * to the session, are committed. 470 */ 471 int 472 __close_cached_mp_write_session(struct cached_connection_ *ws) 473 { 474 int notification; 475 int result __unused; 476 477 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION; 478 result = safe_write(ws, ¬ification, sizeof(int)); 479 __close_cached_connection(ws); 480 return (0); 481 } 482 483 struct cached_connection_ * 484 __open_cached_mp_read_session(struct cached_connection_params const *params, 485 const char *entry_name) 486 { 487 struct cached_connection_ *connection, *retval; 488 size_t name_size; 489 int error_code; 490 int result; 491 492 retval = NULL; 493 connection = __open_cached_connection(params); 494 if (connection == NULL) 495 return (NULL); 496 connection->mp_flag = 1; 497 498 result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST); 499 if (result != 0) 500 goto fin; 501 502 name_size = strlen(entry_name); 503 result = safe_write(connection, &name_size, sizeof(size_t)); 504 if (result != 0) 505 goto fin; 506 507 result = safe_write(connection, entry_name, name_size); 508 if (result != 0) 509 goto fin; 510 511 result = safe_read(connection, &error_code, sizeof(int)); 512 if (result != 0) 513 goto fin; 514 515 if (error_code != 0) 516 result = error_code; 517 518 fin: 519 if (result != 0) 520 __close_cached_connection(connection); 521 else 522 retval = connection; 523 return (retval); 524 } 525 526 int 527 __cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size) 528 { 529 size_t result_size; 530 int error_code, rec_error_code; 531 int request, result; 532 533 error_code = -1; 534 request = CET_MP_READ_SESSION_READ_REQUEST; 535 result = safe_write(rs, &request, sizeof(int)); 536 if (result != 0) 537 goto fin; 538 539 result = safe_read(rs, &rec_error_code, sizeof(int)); 540 if (result != 0) 541 goto fin; 542 543 if (rec_error_code != 0) { 544 error_code = rec_error_code; 545 goto fin; 546 } 547 548 result = safe_read(rs, &result_size, sizeof(size_t)); 549 if (result != 0) 550 goto fin; 551 552 if (result_size > *data_size) { 553 *data_size = result_size; 554 error_code = -2; 555 goto fin; 556 } 557 558 result = safe_read(rs, data, result_size); 559 if (result != 0) 560 goto fin; 561 562 *data_size = result_size; 563 error_code = 0; 564 565 fin: 566 return (error_code); 567 } 568 569 int 570 __close_cached_mp_read_session(struct cached_connection_ *rs) 571 { 572 573 __close_cached_connection(rs); 574 return (0); 575 } 576