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 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include "namespace.h" 32 #include <sys/types.h> 33 #include <sys/socket.h> 34 #include <sys/event.h> 35 #include <sys/uio.h> 36 #include <sys/un.h> 37 #include <assert.h> 38 #include <errno.h> 39 #include <fcntl.h> 40 #include <stdlib.h> 41 #include <string.h> 42 #include <unistd.h> 43 #include "un-namespace.h" 44 #include "nscachedcli.h" 45 46 #define NS_DEFAULT_CACHED_IO_TIMEOUT 4 47 48 static int safe_write(struct cached_connection_ *, const void *, size_t); 49 static int safe_read(struct cached_connection_ *, void *, size_t); 50 static int send_credentials(struct cached_connection_ *, int); 51 52 /* 53 * safe_write writes data to the specified connection and tries to do it in 54 * the very safe manner. We ensure, that we can write to the socket with 55 * kevent. If the data_size can't be sent in one piece, then it would be 56 * splitted. 57 */ 58 static int 59 safe_write(struct cached_connection_ *connection, const void *data, 60 size_t data_size) 61 { 62 struct kevent eventlist; 63 int nevents; 64 size_t result; 65 ssize_t s_result; 66 struct timespec timeout; 67 68 if (data_size == 0) 69 return (0); 70 71 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 72 timeout.tv_nsec = 0; 73 result = 0; 74 do { 75 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 76 1, &timeout); 77 if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) { 78 s_result = _sendto(connection->sockfd, data + result, 79 eventlist.data < data_size - result ? 80 eventlist.data : data_size - result, MSG_NOSIGNAL, 81 NULL, 0); 82 if (s_result == -1) 83 return (-1); 84 else 85 result += s_result; 86 87 if (eventlist.flags & EV_EOF) 88 return (result < data_size ? -1 : 0); 89 } else 90 return (-1); 91 } while (result < data_size); 92 93 return (0); 94 } 95 96 /* 97 * safe_read reads data from connection and tries to do it in the very safe 98 * and stable way. It uses kevent to ensure, that the data are availabe for 99 * reading. If the amount of data to be read is too large, then they would 100 * be splitted. 101 */ 102 static int 103 safe_read(struct cached_connection_ *connection, void *data, size_t data_size) 104 { 105 struct kevent eventlist; 106 size_t result; 107 ssize_t s_result; 108 struct timespec timeout; 109 int nevents; 110 111 if (data_size == 0) 112 return (0); 113 114 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 115 timeout.tv_nsec = 0; 116 result = 0; 117 do { 118 nevents = _kevent(connection->read_queue, NULL, 0, &eventlist, 119 1, &timeout); 120 if (nevents == 1 && eventlist.filter == EVFILT_READ) { 121 s_result = _read(connection->sockfd, 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; 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, 180 MSG_NOSIGNAL) == -1) ? -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 | SOCK_CLOEXEC, 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 = 0; 265 result = send_credentials(connection, CET_WRITE_REQUEST); 266 if (result != 0) 267 goto fin; 268 269 name_size = strlen(entry_name); 270 result = safe_write(connection, &name_size, sizeof(size_t)); 271 if (result != 0) 272 goto fin; 273 274 result = safe_write(connection, &key_size, sizeof(size_t)); 275 if (result != 0) 276 goto fin; 277 278 result = safe_write(connection, &data_size, sizeof(size_t)); 279 if (result != 0) 280 goto fin; 281 282 result = safe_write(connection, entry_name, name_size); 283 if (result != 0) 284 goto fin; 285 286 result = safe_write(connection, key, key_size); 287 if (result != 0) 288 goto fin; 289 290 result = safe_write(connection, data, data_size); 291 if (result != 0) 292 goto fin; 293 294 result = safe_read(connection, &error_code, sizeof(int)); 295 if (result != 0) 296 error_code = -1; 297 298 fin: 299 return (error_code); 300 } 301 302 /* 303 * This function is very close to the cache_read function of the caching 304 * library, which is used in the caching daemon. It reads cached data with the 305 * specified key from the cache entry with entry_name. 306 */ 307 int 308 __cached_read(struct cached_connection_ *connection, const char *entry_name, 309 const char *key, size_t key_size, char *data, size_t *data_size) 310 { 311 size_t name_size, result_size; 312 int error_code, rec_error_code; 313 int result; 314 315 assert(connection != NULL); 316 result = 0; 317 error_code = -1; 318 319 result = send_credentials(connection, CET_READ_REQUEST); 320 if (result != 0) 321 goto fin; 322 323 name_size = strlen(entry_name); 324 result = safe_write(connection, &name_size, sizeof(size_t)); 325 if (result != 0) 326 goto fin; 327 328 result = safe_write(connection, &key_size, sizeof(size_t)); 329 if (result != 0) 330 goto fin; 331 332 result = safe_write(connection, entry_name, name_size); 333 if (result != 0) 334 goto fin; 335 336 result = safe_write(connection, key, key_size); 337 if (result != 0) 338 goto fin; 339 340 result = safe_read(connection, &rec_error_code, sizeof(int)); 341 if (result != 0) 342 goto fin; 343 344 if (rec_error_code != 0) { 345 error_code = rec_error_code; 346 goto fin; 347 } 348 349 result = safe_read(connection, &result_size, sizeof(size_t)); 350 if (result != 0) 351 goto fin; 352 353 if (result_size > *data_size) { 354 *data_size = result_size; 355 error_code = -2; 356 goto fin; 357 } 358 359 result = safe_read(connection, data, result_size); 360 if (result != 0) 361 goto fin; 362 363 *data_size = result_size; 364 error_code = 0; 365 366 fin: 367 return (error_code); 368 } 369 370 /* 371 * Initializes the mp_write_session. For such a session the new connection 372 * would be opened. The data should be written to the session with 373 * __cached_mp_write function. The __close_cached_mp_write_session function 374 * should be used to submit session and __abandon_cached_mp_write_session - to 375 * abandon it. When the session is submitted, the whole se 376 */ 377 struct cached_connection_ * 378 __open_cached_mp_write_session(struct cached_connection_params const *params, 379 const char *entry_name) 380 { 381 struct cached_connection_ *connection, *retval; 382 size_t name_size; 383 int error_code; 384 int result; 385 386 retval = NULL; 387 connection = __open_cached_connection(params); 388 if (connection == NULL) 389 return (NULL); 390 connection->mp_flag = 1; 391 392 result = send_credentials(connection, CET_MP_WRITE_SESSION_REQUEST); 393 if (result != 0) 394 goto fin; 395 396 name_size = strlen(entry_name); 397 result = safe_write(connection, &name_size, sizeof(size_t)); 398 if (result != 0) 399 goto fin; 400 401 result = safe_write(connection, entry_name, name_size); 402 if (result != 0) 403 goto fin; 404 405 result = safe_read(connection, &error_code, sizeof(int)); 406 if (result != 0) 407 goto fin; 408 409 if (error_code != 0) 410 result = error_code; 411 412 fin: 413 if (result != 0) 414 __close_cached_connection(connection); 415 else 416 retval = connection; 417 return (retval); 418 } 419 420 /* 421 * Adds new portion of data to the opened write session 422 */ 423 int 424 __cached_mp_write(struct cached_connection_ *ws, const char *data, 425 size_t data_size) 426 { 427 int request, result; 428 int error_code; 429 430 error_code = -1; 431 432 request = CET_MP_WRITE_SESSION_WRITE_REQUEST; 433 result = safe_write(ws, &request, sizeof(int)); 434 if (result != 0) 435 goto fin; 436 437 result = safe_write(ws, &data_size, sizeof(size_t)); 438 if (result != 0) 439 goto fin; 440 441 result = safe_write(ws, data, data_size); 442 if (result != 0) 443 goto fin; 444 445 result = safe_read(ws, &error_code, sizeof(int)); 446 if (result != 0) 447 error_code = -1; 448 449 fin: 450 return (error_code); 451 } 452 453 /* 454 * Abandons all operations with the write session. All data, that were written 455 * to the session before, are discarded. 456 */ 457 int 458 __abandon_cached_mp_write_session(struct cached_connection_ *ws) 459 { 460 int notification; 461 int result; 462 463 notification = CET_MP_WRITE_SESSION_ABANDON_NOTIFICATION; 464 result = safe_write(ws, ¬ification, sizeof(int)); 465 __close_cached_connection(ws); 466 return (result); 467 } 468 469 /* 470 * Gracefully closes the write session. The data, that were previously written 471 * to the session, are committed. 472 */ 473 int 474 __close_cached_mp_write_session(struct cached_connection_ *ws) 475 { 476 int notification; 477 int result; 478 479 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION; 480 result = safe_write(ws, ¬ification, sizeof(int)); 481 __close_cached_connection(ws); 482 return (0); 483 } 484 485 struct cached_connection_ * 486 __open_cached_mp_read_session(struct cached_connection_params const *params, 487 const char *entry_name) 488 { 489 struct cached_connection_ *connection, *retval; 490 size_t name_size; 491 int error_code; 492 int result; 493 494 retval = NULL; 495 connection = __open_cached_connection(params); 496 if (connection == NULL) 497 return (NULL); 498 connection->mp_flag = 1; 499 500 result = send_credentials(connection, CET_MP_READ_SESSION_REQUEST); 501 if (result != 0) 502 goto fin; 503 504 name_size = strlen(entry_name); 505 result = safe_write(connection, &name_size, sizeof(size_t)); 506 if (result != 0) 507 goto fin; 508 509 result = safe_write(connection, entry_name, name_size); 510 if (result != 0) 511 goto fin; 512 513 result = safe_read(connection, &error_code, sizeof(int)); 514 if (result != 0) 515 goto fin; 516 517 if (error_code != 0) 518 result = error_code; 519 520 fin: 521 if (result != 0) 522 __close_cached_connection(connection); 523 else 524 retval = connection; 525 return (retval); 526 } 527 528 int 529 __cached_mp_read(struct cached_connection_ *rs, char *data, size_t *data_size) 530 { 531 size_t result_size; 532 int error_code, rec_error_code; 533 int request, result; 534 535 error_code = -1; 536 request = CET_MP_READ_SESSION_READ_REQUEST; 537 result = safe_write(rs, &request, sizeof(int)); 538 if (result != 0) 539 goto fin; 540 541 result = safe_read(rs, &rec_error_code, sizeof(int)); 542 if (result != 0) 543 goto fin; 544 545 if (rec_error_code != 0) { 546 error_code = rec_error_code; 547 goto fin; 548 } 549 550 result = safe_read(rs, &result_size, sizeof(size_t)); 551 if (result != 0) 552 goto fin; 553 554 if (result_size > *data_size) { 555 *data_size = result_size; 556 error_code = -2; 557 goto fin; 558 } 559 560 result = safe_read(rs, data, result_size); 561 if (result != 0) 562 goto fin; 563 564 *data_size = result_size; 565 error_code = 0; 566 567 fin: 568 return (error_code); 569 } 570 571 int 572 __close_cached_mp_read_session(struct cached_connection_ *rs) 573 { 574 575 __close_cached_connection(rs); 576 return (0); 577 } 578