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, data + result, 77 eventlist.data < data_size - result ? 78 eventlist.data : data_size - result); 79 if (s_result == -1) 80 return (-1); 81 else 82 result += s_result; 83 84 if (eventlist.flags & EV_EOF) 85 return (result < data_size ? -1 : 0); 86 } else 87 return (-1); 88 } while (result < data_size); 89 90 return (0); 91 } 92 93 /* 94 * safe_read reads data from connection and tries to do it in the very safe 95 * and stable way. It uses kevent to ensure, that the data are availabe for 96 * reading. If the amount of data to be read is too large, then they would 97 * be splitted. 98 */ 99 static int 100 safe_read(struct cached_connection_ *connection, void *data, size_t data_size) 101 { 102 struct kevent eventlist; 103 size_t result; 104 ssize_t s_result; 105 struct timespec timeout; 106 int nevents; 107 108 if (data_size == 0) 109 return (0); 110 111 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 112 timeout.tv_nsec = 0; 113 result = 0; 114 do { 115 nevents = _kevent(connection->read_queue, NULL, 0, &eventlist, 116 1, &timeout); 117 if (nevents == 1 && eventlist.filter == EVFILT_READ) { 118 s_result = _read(connection->sockfd, data + result, 119 eventlist.data <= data_size - result ? 120 eventlist.data : data_size - result); 121 if (s_result == -1) 122 return (-1); 123 else 124 result += s_result; 125 126 if (eventlist.flags & EV_EOF) 127 return (result < data_size ? -1 : 0); 128 } else 129 return (-1); 130 } while (result < data_size); 131 132 return (0); 133 } 134 135 /* 136 * Sends the credentials information to the connection along with the 137 * communication element type. 138 */ 139 static int 140 send_credentials(struct cached_connection_ *connection, int type) 141 { 142 struct kevent eventlist; 143 int nevents; 144 ssize_t result; 145 int res; 146 147 struct msghdr cred_hdr; 148 struct iovec iov; 149 150 struct { 151 struct cmsghdr hdr; 152 char cred[CMSG_SPACE(sizeof(struct cmsgcred))]; 153 } cmsg; 154 155 memset(&cmsg, 0, sizeof(cmsg)); 156 cmsg.hdr.cmsg_len = CMSG_LEN(sizeof(struct cmsgcred)); 157 cmsg.hdr.cmsg_level = SOL_SOCKET; 158 cmsg.hdr.cmsg_type = SCM_CREDS; 159 160 memset(&cred_hdr, 0, sizeof(struct msghdr)); 161 cred_hdr.msg_iov = &iov; 162 cred_hdr.msg_iovlen = 1; 163 cred_hdr.msg_control = (caddr_t)&cmsg; 164 cred_hdr.msg_controllen = CMSG_SPACE(sizeof(struct cmsgcred)); 165 166 iov.iov_base = &type; 167 iov.iov_len = sizeof(int); 168 169 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD, 170 NOTE_LOWAT, sizeof(int), NULL); 171 res = _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL); 172 173 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 1, 174 NULL); 175 if (nevents == 1 && eventlist.filter == EVFILT_WRITE) { 176 result = (_sendmsg(connection->sockfd, &cred_hdr, 0) == -1) ? 177 -1 : 0; 178 EV_SET(&eventlist, connection->sockfd, EVFILT_WRITE, EV_ADD, 179 0, 0, NULL); 180 _kevent(connection->write_queue, &eventlist, 1, NULL, 0, NULL); 181 return (result); 182 } else 183 return (-1); 184 } 185 186 /* 187 * Opens the connection with the specified params. Initializes all kqueues. 188 */ 189 struct cached_connection_ * 190 __open_cached_connection(struct cached_connection_params const *params) 191 { 192 struct cached_connection_ *retval; 193 struct kevent eventlist; 194 struct sockaddr_un client_address; 195 int client_address_len, client_socket; 196 int res; 197 198 assert(params != NULL); 199 200 client_socket = _socket(PF_LOCAL, SOCK_STREAM, 0); 201 client_address.sun_family = PF_LOCAL; 202 strncpy(client_address.sun_path, params->socket_path, 203 sizeof(client_address.sun_path)); 204 client_address_len = sizeof(client_address.sun_family) + 205 strlen(client_address.sun_path) + 1; 206 207 res = _connect(client_socket, (struct sockaddr *)&client_address, 208 client_address_len); 209 if (res == -1) { 210 _close(client_socket); 211 return (NULL); 212 } 213 _fcntl(client_socket, F_SETFL, O_NONBLOCK); 214 215 retval = malloc(sizeof(struct cached_connection_)); 216 assert(retval != NULL); 217 memset(retval, 0, sizeof(struct cached_connection_)); 218 219 retval->sockfd = client_socket; 220 221 retval->write_queue = kqueue(); 222 assert(retval->write_queue != -1); 223 224 EV_SET(&eventlist, retval->sockfd, EVFILT_WRITE, EV_ADD, 0, 0, NULL); 225 res = _kevent(retval->write_queue, &eventlist, 1, NULL, 0, NULL); 226 227 retval->read_queue = kqueue(); 228 assert(retval->read_queue != -1); 229 230 EV_SET(&eventlist, retval->sockfd, EVFILT_READ, EV_ADD, 0, 0, NULL); 231 res = _kevent(retval->read_queue, &eventlist, 1, NULL, 0, NULL); 232 233 return (retval); 234 } 235 236 void 237 __close_cached_connection(struct cached_connection_ *connection) 238 { 239 assert(connection != NULL); 240 241 _close(connection->sockfd); 242 _close(connection->read_queue); 243 _close(connection->write_queue); 244 free(connection); 245 } 246 247 /* 248 * This function is very close to the cache_write function of the caching 249 * library, which is used in the caching daemon. It caches the data with the 250 * specified key in the cache entry with entry_name. 251 */ 252 int 253 __cached_write(struct cached_connection_ *connection, const char *entry_name, 254 const char *key, size_t key_size, const char *data, size_t data_size) 255 { 256 size_t name_size; 257 int error_code; 258 int result; 259 260 error_code = -1; 261 result = 0; 262 result = send_credentials(connection, CET_WRITE_REQUEST); 263 if (result != 0) 264 goto fin; 265 266 name_size = strlen(entry_name); 267 result = safe_write(connection, &name_size, sizeof(size_t)); 268 if (result != 0) 269 goto fin; 270 271 result = safe_write(connection, &key_size, sizeof(size_t)); 272 if (result != 0) 273 goto fin; 274 275 result = safe_write(connection, &data_size, sizeof(size_t)); 276 if (result != 0) 277 goto fin; 278 279 result = safe_write(connection, entry_name, name_size); 280 if (result != 0) 281 goto fin; 282 283 result = safe_write(connection, key, key_size); 284 if (result != 0) 285 goto fin; 286 287 result = safe_write(connection, data, data_size); 288 if (result != 0) 289 goto fin; 290 291 result = safe_read(connection, &error_code, sizeof(int)); 292 if (result != 0) 293 error_code = -1; 294 295 fin: 296 return (error_code); 297 } 298 299 /* 300 * This function is very close to the cache_read function of the caching 301 * library, which is used in the caching daemon. It reads cached data with the 302 * specified key from the cache entry with entry_name. 303 */ 304 int 305 __cached_read(struct cached_connection_ *connection, const char *entry_name, 306 const char *key, size_t key_size, char *data, size_t *data_size) 307 { 308 size_t name_size, result_size; 309 int error_code, rec_error_code; 310 int result; 311 312 assert(connection != NULL); 313 result = 0; 314 error_code = -1; 315 316 result = send_credentials(connection, CET_READ_REQUEST); 317 if (result != 0) 318 goto fin; 319 320 name_size = strlen(entry_name); 321 result = safe_write(connection, &name_size, sizeof(size_t)); 322 if (result != 0) 323 goto fin; 324 325 result = safe_write(connection, &key_size, sizeof(size_t)); 326 if (result != 0) 327 goto fin; 328 329 result = safe_write(connection, entry_name, name_size); 330 if (result != 0) 331 goto fin; 332 333 result = safe_write(connection, key, key_size); 334 if (result != 0) 335 goto fin; 336 337 result = safe_read(connection, &rec_error_code, sizeof(int)); 338 if (result != 0) 339 goto fin; 340 341 if (rec_error_code != 0) { 342 error_code = rec_error_code; 343 goto fin; 344 } 345 346 result = safe_read(connection, &result_size, sizeof(size_t)); 347 if (result != 0) 348 goto fin; 349 350 if (result_size > *data_size) { 351 *data_size = result_size; 352 error_code = -2; 353 goto fin; 354 } 355 356 result = safe_read(connection, data, result_size); 357 if (result != 0) 358 goto fin; 359 360 *data_size = result_size; 361 error_code = 0; 362 363 fin: 364 return (error_code); 365 } 366 367 /* 368 * Initializes the mp_write_session. For such a session the new connection 369 * would be opened. The data should be written to the session with 370 * __cached_mp_write function. The __close_cached_mp_write_session function 371 * should be used to submit session and __abandon_cached_mp_write_session - to 372 * abandon it. When the session is submitted, the whole se 373 */ 374 struct cached_connection_ * 375 __open_cached_mp_write_session(struct cached_connection_params const *params, 376 const char *entry_name) 377 { 378 struct cached_connection_ *connection, *retval; 379 size_t name_size; 380 int error_code; 381 int result; 382 383 retval = NULL; 384 connection = __open_cached_connection(params); 385 if (connection == NULL) 386 return (NULL); 387 connection->mp_flag = 1; 388 389 result = send_credentials(connection, CET_MP_WRITE_SESSION_REQUEST); 390 if (result != 0) 391 goto fin; 392 393 name_size = strlen(entry_name); 394 result = safe_write(connection, &name_size, sizeof(size_t)); 395 if (result != 0) 396 goto fin; 397 398 result = safe_write(connection, entry_name, name_size); 399 if (result != 0) 400 goto fin; 401 402 result = safe_read(connection, &error_code, sizeof(int)); 403 if (result != 0) 404 goto fin; 405 406 if (error_code != 0) 407 result = error_code; 408 409 fin: 410 if (result != 0) 411 __close_cached_connection(connection); 412 else 413 retval = connection; 414 return (retval); 415 } 416 417 /* 418 * Adds new portion of data to the opened write session 419 */ 420 int 421 __cached_mp_write(struct cached_connection_ *ws, const char *data, 422 size_t data_size) 423 { 424 int request, result; 425 int error_code; 426 427 error_code = -1; 428 429 request = CET_MP_WRITE_SESSION_WRITE_REQUEST; 430 result = safe_write(ws, &request, sizeof(int)); 431 if (result != 0) 432 goto fin; 433 434 result = safe_write(ws, &data_size, sizeof(size_t)); 435 if (result != 0) 436 goto fin; 437 438 result = safe_write(ws, data, data_size); 439 if (result != 0) 440 goto fin; 441 442 result = safe_read(ws, &error_code, sizeof(int)); 443 if (result != 0) 444 error_code = -1; 445 446 fin: 447 return (error_code); 448 } 449 450 /* 451 * Abandons all operations with the write session. All data, that were written 452 * to the session before, are discarded. 453 */ 454 int 455 __abandon_cached_mp_write_session(struct cached_connection_ *ws) 456 { 457 int notification; 458 int result; 459 460 notification = CET_MP_WRITE_SESSION_ABANDON_NOTIFICATION; 461 result = safe_write(ws, ¬ification, sizeof(int)); 462 __close_cached_connection(ws); 463 return (result); 464 } 465 466 /* 467 * Gracefully closes the write session. The data, that were previously written 468 * to the session, are committed. 469 */ 470 int 471 __close_cached_mp_write_session(struct cached_connection_ *ws) 472 { 473 int notification; 474 int result; 475 476 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION; 477 result = safe_write(ws, ¬ification, sizeof(int)); 478 __close_cached_connection(ws); 479 return (0); 480 } 481 482 struct cached_connection_ * 483 __open_cached_mp_read_session(struct cached_connection_params const *params, 484 const char *entry_name) 485 { 486 struct cached_connection_ *connection, *retval; 487 size_t name_size; 488 int error_code; 489 int result; 490 491 retval = NULL; 492 connection = __open_cached_connection(params); 493 if (connection == NULL) 494 return (NULL); 495 connection->mp_flag = 1; 496 497 result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST); 498 if (result != 0) 499 goto fin; 500 501 name_size = strlen(entry_name); 502 result = safe_write(connection, &name_size, sizeof(size_t)); 503 if (result != 0) 504 goto fin; 505 506 result = safe_write(connection, entry_name, name_size); 507 if (result != 0) 508 goto fin; 509 510 result = safe_read(connection, &error_code, sizeof(int)); 511 if (result != 0) 512 goto fin; 513 514 if (error_code != 0) 515 result = error_code; 516 517 fin: 518 if (result != 0) 519 __close_cached_connection(connection); 520 else 521 retval = connection; 522 return (retval); 523 } 524 525 int 526 __cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size) 527 { 528 size_t result_size; 529 int error_code, rec_error_code; 530 int request, result; 531 532 error_code = -1; 533 request = CET_MP_READ_SESSION_READ_REQUEST; 534 result = safe_write(rs, &request, sizeof(int)); 535 if (result != 0) 536 goto fin; 537 538 result = safe_read(rs, &rec_error_code, sizeof(int)); 539 if (result != 0) 540 goto fin; 541 542 if (rec_error_code != 0) { 543 error_code = rec_error_code; 544 goto fin; 545 } 546 547 result = safe_read(rs, &result_size, sizeof(size_t)); 548 if (result != 0) 549 goto fin; 550 551 if (result_size > *data_size) { 552 *data_size = result_size; 553 error_code = -2; 554 goto fin; 555 } 556 557 result = safe_read(rs, data, result_size); 558 if (result != 0) 559 goto fin; 560 561 *data_size = result_size; 562 error_code = 0; 563 564 fin: 565 return (error_code); 566 } 567 568 int 569 __close_cached_mp_read_session(struct cached_connection_ *rs) 570 { 571 572 __close_cached_connection(rs); 573 return (0); 574 } 575