1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2005 Michael Bushkov <bushman@rsu.ru> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include "namespace.h" 34 #include <sys/types.h> 35 #include <sys/socket.h> 36 #include <sys/event.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 #include <assert.h> 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <unistd.h> 45 #include "un-namespace.h" 46 #include "nscachedcli.h" 47 48 #define NS_DEFAULT_CACHED_IO_TIMEOUT 4 49 50 static int safe_write(struct cached_connection_ *, const void *, size_t); 51 static int safe_read(struct cached_connection_ *, void *, size_t); 52 static int send_credentials(struct cached_connection_ *, int); 53 54 /* 55 * safe_write writes data to the specified connection and tries to do it in 56 * the very safe manner. We ensure, that we can write to the socket with 57 * kevent. If the data_size can't be sent in one piece, then it would be 58 * splitted. 59 */ 60 static int 61 safe_write(struct cached_connection_ *connection, const void *data, 62 size_t data_size) 63 { 64 struct kevent eventlist; 65 int nevents; 66 size_t result; 67 ssize_t s_result; 68 struct timespec timeout; 69 70 if (data_size == 0) 71 return (0); 72 73 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 74 timeout.tv_nsec = 0; 75 result = 0; 76 do { 77 nevents = _kevent(connection->write_queue, NULL, 0, &eventlist, 78 1, &timeout); 79 if ((nevents == 1) && (eventlist.filter == EVFILT_WRITE)) { 80 s_result = _sendto(connection->sockfd, data + result, 81 eventlist.data < data_size - result ? 82 eventlist.data : data_size - result, MSG_NOSIGNAL, 83 NULL, 0); 84 if (s_result == -1) 85 return (-1); 86 else 87 result += s_result; 88 89 if (eventlist.flags & EV_EOF) 90 return (result < data_size ? -1 : 0); 91 } else 92 return (-1); 93 } while (result < data_size); 94 95 return (0); 96 } 97 98 /* 99 * safe_read reads data from connection and tries to do it in the very safe 100 * and stable way. It uses kevent to ensure, that the data are available for 101 * reading. If the amount of data to be read is too large, then they would 102 * be splitted. 103 */ 104 static int 105 safe_read(struct cached_connection_ *connection, void *data, size_t data_size) 106 { 107 struct kevent eventlist; 108 size_t result; 109 ssize_t s_result; 110 struct timespec timeout; 111 int nevents; 112 113 if (data_size == 0) 114 return (0); 115 116 timeout.tv_sec = NS_DEFAULT_CACHED_IO_TIMEOUT; 117 timeout.tv_nsec = 0; 118 result = 0; 119 do { 120 nevents = _kevent(connection->read_queue, NULL, 0, &eventlist, 121 1, &timeout); 122 if (nevents == 1 && eventlist.filter == EVFILT_READ) { 123 s_result = _read(connection->sockfd, data + result, 124 eventlist.data <= data_size - result ? 125 eventlist.data : data_size - result); 126 if (s_result == -1) 127 return (-1); 128 else 129 result += s_result; 130 131 if (eventlist.flags & EV_EOF) 132 return (result < data_size ? -1 : 0); 133 } else 134 return (-1); 135 } while (result < data_size); 136 137 return (0); 138 } 139 140 /* 141 * Sends the credentials information to the connection along with the 142 * communication element type. 143 */ 144 static int 145 send_credentials(struct cached_connection_ *connection, int type) 146 { 147 union { 148 struct cmsghdr hdr; 149 char pad[CMSG_SPACE(sizeof(struct cmsgcred))]; 150 } cmsg; 151 struct msghdr mhdr; 152 struct iovec iov; 153 struct kevent eventlist; 154 int nevents; 155 ssize_t result; 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(&mhdr, 0, sizeof(mhdr)); 163 mhdr.msg_iov = &iov; 164 mhdr.msg_iovlen = 1; 165 mhdr.msg_control = &cmsg; 166 mhdr.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 (void)_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, &mhdr, 179 MSG_NOSIGNAL) == -1 ? -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 | SOCK_CLOEXEC, 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; 476 477 notification = CET_MP_WRITE_SESSION_CLOSE_NOTIFICATION; 478 (void)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