Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 1 | /* Copyright 2018 IBM Corp. |
| 2 | * |
| 3 | * Author: Jeremy Kerr <jk@ozlabs.org> |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| 6 | * use this file except in compliance with the License. You may obtain a copy |
| 7 | * of the License at |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| 13 | * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| 14 | * License for the specific language governing permissions and limitations |
| 15 | * under the License. |
| 16 | */ |
| 17 | |
| 18 | #define _GNU_SOURCE |
| 19 | |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 20 | #include <dirent.h> |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 21 | #include <err.h> |
| 22 | #include <errno.h> |
| 23 | #include <fcntl.h> |
Jeremy Kerr | 6f9c433 | 2018-08-03 17:11:15 +0800 | [diff] [blame] | 24 | #include <getopt.h> |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 25 | #include <limits.h> |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 26 | #include <signal.h> |
| 27 | #include <stdbool.h> |
| 28 | #include <stdint.h> |
| 29 | #include <stdio.h> |
| 30 | #include <stdlib.h> |
| 31 | #include <string.h> |
| 32 | #include <unistd.h> |
| 33 | |
| 34 | #include <sys/poll.h> |
| 35 | #include <sys/socket.h> |
| 36 | #include <sys/stat.h> |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 37 | #include <sys/types.h> |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 38 | #include <sys/un.h> |
| 39 | #include <sys/wait.h> |
| 40 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 41 | #include <json.h> |
| 42 | |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 43 | #include "config.h" |
| 44 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 45 | struct config { |
| 46 | char *name; |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 47 | bool is_default; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 48 | char *nbd_device; |
| 49 | struct json_object *metadata; |
| 50 | }; |
| 51 | |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 52 | struct ctx { |
| 53 | int sock; |
| 54 | int sock_client; |
| 55 | int signal_pipe[2]; |
| 56 | char *sock_path; |
| 57 | pid_t nbd_client_pid; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 58 | int nbd_timeout; |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 59 | uint8_t *buf; |
| 60 | size_t bufsize; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 61 | struct config *configs; |
| 62 | int n_configs; |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 63 | struct config *default_config; |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 64 | struct config *config; |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 65 | }; |
| 66 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 67 | static const char *conf_path = SYSCONFDIR "/nbd-proxy/config.json"; |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 68 | static const char *state_hook_path = SYSCONFDIR "/nbd-proxy/state.d"; |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 69 | static const char *sockpath_tmpl = RUNSTATEDIR "/nbd.%d.sock"; |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 70 | |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 71 | static const size_t bufsize = 0x20000; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 72 | static const int nbd_timeout_default = 30; |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 73 | |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 74 | #define BUILD_ASSERT_OR_ZERO(c) (sizeof(struct {int:-!(c);})) |
| 75 | |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 76 | static int open_nbd_socket(struct ctx *ctx) |
| 77 | { |
| 78 | struct sockaddr_un addr; |
| 79 | char *path; |
| 80 | int sd, rc; |
| 81 | |
| 82 | rc = asprintf(&path, sockpath_tmpl, getpid()); |
| 83 | if (rc < 0) |
| 84 | return -1; |
| 85 | |
| 86 | sd = socket(AF_UNIX, SOCK_STREAM, 0); |
| 87 | if (sd < 0) { |
| 88 | warn("can't create socket"); |
| 89 | goto err_free; |
| 90 | } |
| 91 | |
| 92 | rc = fchmod(sd, S_IRUSR | S_IWUSR); |
| 93 | if (rc) { |
| 94 | warn("can't set permissions on socket"); |
| 95 | goto err_close; |
| 96 | } |
| 97 | |
| 98 | addr.sun_family = AF_UNIX; |
| 99 | strncpy(addr.sun_path, path, sizeof(addr.sun_path)); |
| 100 | |
| 101 | rc = bind(sd, (struct sockaddr *)&addr, sizeof(addr)); |
| 102 | if (rc) { |
| 103 | warn("can't bind to path %s", path); |
| 104 | goto err_close; |
| 105 | } |
| 106 | |
| 107 | rc = listen(sd, 1); |
| 108 | if (rc) { |
| 109 | warn("can't listen on socket %s", path); |
| 110 | goto err_unlink; |
| 111 | } |
| 112 | |
| 113 | ctx->sock = sd; |
| 114 | ctx->sock_path = path; |
| 115 | return 0; |
| 116 | |
| 117 | err_unlink: |
| 118 | unlink(path); |
| 119 | err_close: |
| 120 | close(sd); |
| 121 | err_free: |
| 122 | free(path); |
| 123 | return -1; |
| 124 | } |
| 125 | |
| 126 | static int start_nbd_client(struct ctx *ctx) |
| 127 | { |
| 128 | pid_t pid; |
| 129 | |
| 130 | pid = fork(); |
| 131 | if (pid < 0) { |
| 132 | warn("can't create client process"); |
| 133 | return -1; |
| 134 | } |
| 135 | |
| 136 | /* child process: run nbd-client in non-fork mode */ |
| 137 | if (pid == 0) { |
Jeremy Kerr | 09295f2 | 2018-07-27 16:29:38 +0800 | [diff] [blame] | 138 | char timeout_str[10]; |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 139 | int fd; |
| 140 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 141 | snprintf(timeout_str, sizeof(timeout_str), |
| 142 | "%d", ctx->nbd_timeout); |
Jeremy Kerr | 09295f2 | 2018-07-27 16:29:38 +0800 | [diff] [blame] | 143 | |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 144 | fd = open("/dev/null", O_RDWR); |
| 145 | if (fd < 0) |
| 146 | err(EXIT_FAILURE, "can't open /dev/null"); |
| 147 | |
| 148 | dup2(fd, STDIN_FILENO); |
| 149 | dup2(fd, STDOUT_FILENO); |
| 150 | dup2(fd, STDERR_FILENO); |
| 151 | close(fd); |
| 152 | close(ctx->sock); |
| 153 | |
| 154 | execlp("nbd-client", "nbd-client", |
| 155 | "-u", ctx->sock_path, |
| 156 | "-n", |
Jeremy Kerr | 09295f2 | 2018-07-27 16:29:38 +0800 | [diff] [blame] | 157 | "-t", timeout_str, |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 158 | ctx->config->nbd_device, |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 159 | NULL); |
| 160 | err(EXIT_FAILURE, "can't start ndb client"); |
| 161 | } |
| 162 | |
| 163 | ctx->nbd_client_pid = pid; |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | static void stop_nbd_client(struct ctx *ctx) |
| 168 | { |
| 169 | int rc; |
| 170 | |
| 171 | if (!ctx->nbd_client_pid) |
| 172 | return; |
| 173 | |
| 174 | rc = kill(ctx->nbd_client_pid, SIGTERM); |
| 175 | if (rc) |
| 176 | return; |
| 177 | |
| 178 | waitpid(ctx->nbd_client_pid, NULL, 0); |
| 179 | ctx->nbd_client_pid = 0; |
| 180 | } |
| 181 | |
| 182 | static int copy_fd(struct ctx *ctx, int fd_in, int fd_out) |
| 183 | { |
| 184 | #ifdef HAVE_SPLICE |
| 185 | int rc; |
| 186 | |
| 187 | rc = splice(fd_in, NULL, fd_out, NULL, ctx->bufsize, 0); |
| 188 | if (rc < 0) |
| 189 | warn("splice"); |
| 190 | |
| 191 | return rc; |
| 192 | #else |
| 193 | size_t len, pos; |
| 194 | ssize_t rc; |
| 195 | |
| 196 | for (;;) { |
| 197 | errno = 0; |
| 198 | rc = read(fd_in, ctx->buf, ctx->bufsize); |
| 199 | if (rc < 0) { |
| 200 | if (errno == EINTR) |
| 201 | continue; |
| 202 | warn("read failure"); |
| 203 | return -1; |
| 204 | } |
| 205 | if (rc == 0) |
| 206 | return 0; |
| 207 | break; |
| 208 | } |
| 209 | |
| 210 | len = rc; |
| 211 | |
| 212 | for (pos = 0; pos < len;) { |
| 213 | errno = 0; |
| 214 | rc = write(fd_out, ctx->buf + pos, len - pos); |
| 215 | if (rc < 0) { |
| 216 | if (errno == EINTR) |
| 217 | continue; |
| 218 | warn("write failure"); |
| 219 | return -1; |
| 220 | } |
| 221 | if (rc == 0) |
| 222 | break; |
| 223 | pos += rc; |
| 224 | } |
| 225 | |
| 226 | return pos; |
| 227 | #endif |
| 228 | } |
| 229 | |
| 230 | static int signal_pipe_fd = -1; |
| 231 | |
| 232 | static void signal_handler(int signal) |
| 233 | { |
| 234 | int rc; |
| 235 | |
| 236 | rc = write(signal_pipe_fd, &signal, sizeof(signal)); |
| 237 | |
| 238 | /* not a lot we can do here but exit... */ |
| 239 | if (rc != sizeof(signal)) |
| 240 | exit(EXIT_FAILURE); |
| 241 | } |
| 242 | |
| 243 | static int setup_signals(struct ctx *ctx) |
| 244 | { |
| 245 | struct sigaction sa; |
| 246 | int rc; |
| 247 | |
| 248 | rc = pipe(ctx->signal_pipe); |
| 249 | if (rc) { |
| 250 | warn("cant setup signal pipe"); |
| 251 | return -1; |
| 252 | } |
| 253 | |
| 254 | signal_pipe_fd = ctx->signal_pipe[1]; |
| 255 | |
| 256 | memset(&sa, 0, sizeof(sa)); |
| 257 | sa.sa_handler = signal_handler; |
| 258 | |
| 259 | sigaction(SIGINT, &sa, NULL); |
| 260 | sigaction(SIGTERM, &sa, NULL); |
| 261 | sigaction(SIGCHLD, &sa, NULL); |
| 262 | |
| 263 | return 0; |
| 264 | } |
| 265 | |
| 266 | static void cleanup_signals(struct ctx *ctx) |
| 267 | { |
| 268 | struct sigaction sa; |
| 269 | memset(&sa, 0, sizeof(sa)); |
| 270 | sa.sa_handler = SIG_DFL; |
| 271 | |
| 272 | sigaction(SIGINT, &sa, NULL); |
| 273 | sigaction(SIGTERM, &sa, NULL); |
| 274 | sigaction(SIGCHLD, &sa, NULL); |
| 275 | |
| 276 | close(ctx->signal_pipe[0]); |
| 277 | close(ctx->signal_pipe[1]); |
| 278 | } |
| 279 | |
| 280 | static int process_signal_pipe(struct ctx *ctx, bool *exit) |
| 281 | { |
| 282 | int buf, rc, status; |
| 283 | |
| 284 | rc = read(ctx->signal_pipe[0], &buf, sizeof(buf)); |
| 285 | if (rc != sizeof(buf)) |
| 286 | return -1; |
| 287 | |
| 288 | *exit = false; |
| 289 | |
| 290 | switch (buf) { |
| 291 | case SIGCHLD: |
| 292 | rc = waitpid(ctx->nbd_client_pid, &status, WNOHANG); |
| 293 | if (rc > 0) { |
| 294 | warnx("nbd client stopped (%s: %d); exiting", |
| 295 | WIFEXITED(status) ? "rc" : "sig", |
| 296 | WIFEXITED(status) ? |
| 297 | WEXITSTATUS(status) : |
| 298 | WTERMSIG(status)); |
| 299 | ctx->nbd_client_pid = 0; |
| 300 | } |
| 301 | break; |
| 302 | case SIGINT: |
| 303 | case SIGTERM: |
| 304 | *exit = true; |
| 305 | break; |
| 306 | } |
| 307 | |
| 308 | return 0; |
| 309 | } |
| 310 | |
| 311 | static int wait_for_nbd_client(struct ctx *ctx) |
| 312 | { |
| 313 | struct pollfd pollfds[2]; |
| 314 | int rc; |
| 315 | |
| 316 | pollfds[0].fd = ctx->sock; |
| 317 | pollfds[0].events = POLLIN; |
| 318 | pollfds[1].fd = ctx->signal_pipe[0]; |
| 319 | pollfds[1].events = POLLIN; |
| 320 | |
| 321 | for (;;) { |
| 322 | errno = 0; |
| 323 | rc = poll(pollfds, 2, -1); |
| 324 | if (rc < 0) { |
| 325 | if (errno == EINTR) |
| 326 | continue; |
| 327 | warn("poll failed"); |
| 328 | return -1; |
| 329 | } |
| 330 | |
| 331 | if (pollfds[0].revents) { |
| 332 | rc = accept(ctx->sock, NULL, NULL); |
| 333 | if (rc < 0) { |
| 334 | warn("can't create connection"); |
| 335 | return -1; |
| 336 | } |
| 337 | ctx->sock_client = rc; |
| 338 | break; |
| 339 | } |
| 340 | |
| 341 | if (pollfds[1].revents) { |
| 342 | bool exit; |
| 343 | rc = process_signal_pipe(ctx, &exit); |
| 344 | if (rc || exit) |
| 345 | return -1; |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | return 0; |
| 350 | } |
| 351 | |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 352 | #define join_paths(p1, p2, r) \ |
| 353 | (BUILD_ASSERT_OR_ZERO(sizeof(r) > PATH_MAX) + __join_paths(p1, p2, r)) |
| 354 | static int __join_paths(const char *p1, const char *p2, char res[]) |
| 355 | { |
| 356 | size_t len; |
| 357 | char *pos; |
| 358 | |
| 359 | len = strlen(p1) + 1 + strlen(p2); |
| 360 | if (len > PATH_MAX) |
| 361 | return -1; |
| 362 | |
| 363 | pos = res; |
| 364 | strcpy(pos, p1); |
| 365 | pos += strlen(p1); |
| 366 | *pos = '/'; |
| 367 | pos++; |
| 368 | strcpy(pos, p2); |
| 369 | |
| 370 | return 0; |
| 371 | } |
| 372 | |
| 373 | static int run_state_hook(struct ctx *ctx, |
| 374 | const char *path, const char *name, const char *action) |
| 375 | { |
| 376 | int status, rc, fd; |
| 377 | pid_t pid; |
| 378 | |
| 379 | pid = fork(); |
| 380 | if (pid < 0) { |
| 381 | warn("can't fork to execute hook %s", name); |
| 382 | return -1; |
| 383 | } |
| 384 | |
| 385 | if (!pid) { |
| 386 | close(ctx->sock); |
| 387 | close(ctx->sock_client); |
| 388 | close(ctx->signal_pipe[0]); |
| 389 | close(ctx->signal_pipe[1]); |
| 390 | fd = open("/dev/null", O_RDWR); |
| 391 | if (fd < 0) |
| 392 | exit(EXIT_FAILURE); |
| 393 | |
| 394 | dup2(fd, STDIN_FILENO); |
| 395 | dup2(fd, STDOUT_FILENO); |
| 396 | dup2(fd, STDERR_FILENO); |
| 397 | execl(path, name, action, ctx->config->name, NULL); |
| 398 | exit(EXIT_FAILURE); |
| 399 | } |
| 400 | |
| 401 | rc = waitpid(pid, &status, 0); |
| 402 | if (rc < 0) { |
| 403 | warn("wait"); |
| 404 | return -1; |
| 405 | } |
| 406 | |
| 407 | if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { |
| 408 | warnx("hook %s failed", name); |
| 409 | return -1; |
| 410 | } |
| 411 | |
| 412 | return 0; |
| 413 | } |
| 414 | |
| 415 | static int run_state_hooks(struct ctx *ctx, const char *action) |
| 416 | { |
| 417 | struct dirent *dirent; |
| 418 | int rc; |
| 419 | DIR *dir; |
| 420 | |
| 421 | dir = opendir(state_hook_path); |
| 422 | if (!dir) |
| 423 | return 0; |
| 424 | |
| 425 | rc = 0; |
| 426 | |
| 427 | for (dirent = readdir(dir); dirent; dirent = readdir(dir)) { |
| 428 | char full_path[PATH_MAX+1]; |
| 429 | struct stat statbuf; |
| 430 | |
| 431 | if (dirent->d_name[0] == '.') |
| 432 | continue; |
| 433 | |
| 434 | rc = fstatat(dirfd(dir), dirent->d_name, &statbuf, 0); |
| 435 | if (rc) |
| 436 | continue; |
| 437 | |
| 438 | if (!(S_ISREG(statbuf.st_mode) || S_ISLNK(statbuf.st_mode))) |
| 439 | continue; |
| 440 | |
| 441 | if (faccessat(dirfd(dir), dirent->d_name, X_OK, 0)) |
| 442 | continue; |
| 443 | |
| 444 | rc = join_paths(state_hook_path, dirent->d_name, full_path); |
| 445 | if (rc) |
| 446 | continue; |
| 447 | |
| 448 | rc = run_state_hook(ctx, full_path, dirent->d_name, action); |
| 449 | if (rc) |
| 450 | break; |
| 451 | } |
| 452 | |
| 453 | closedir(dir); |
| 454 | |
| 455 | return rc; |
| 456 | } |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 457 | |
| 458 | static int run_proxy(struct ctx *ctx) |
| 459 | { |
| 460 | struct pollfd pollfds[3]; |
| 461 | bool exit = false; |
| 462 | int rc; |
| 463 | |
| 464 | /* main proxy: forward data between stdio & socket */ |
| 465 | pollfds[0].fd = ctx->sock_client; |
| 466 | pollfds[0].events = POLLIN; |
| 467 | pollfds[1].fd = STDIN_FILENO; |
| 468 | pollfds[1].events = POLLIN; |
| 469 | pollfds[2].fd = ctx->signal_pipe[0]; |
| 470 | pollfds[2].events = POLLIN; |
| 471 | |
| 472 | for (;;) { |
| 473 | errno = 0; |
| 474 | rc = poll(pollfds, 3, -1); |
| 475 | if (rc < 0) { |
| 476 | if (errno == EINTR) |
| 477 | continue; |
| 478 | warn("poll failed"); |
| 479 | break; |
| 480 | } |
| 481 | |
| 482 | if (pollfds[0].revents) { |
| 483 | rc = copy_fd(ctx, ctx->sock_client, STDOUT_FILENO); |
| 484 | if (rc <= 0) |
| 485 | break; |
| 486 | } |
| 487 | |
| 488 | if (pollfds[1].revents) { |
| 489 | rc = copy_fd(ctx, STDIN_FILENO, ctx->sock_client); |
| 490 | if (rc <= 0) |
| 491 | break; |
| 492 | } |
| 493 | |
| 494 | if (pollfds[2].revents) { |
| 495 | rc = process_signal_pipe(ctx, &exit); |
| 496 | if (rc || exit) |
| 497 | break; |
| 498 | } |
| 499 | } |
| 500 | |
| 501 | return rc ? -1 : 0; |
| 502 | } |
| 503 | |
Jeremy Kerr | 13bb28f | 2018-08-09 10:41:10 +0800 | [diff] [blame] | 504 | static void print_metadata(struct ctx *ctx) |
| 505 | { |
| 506 | struct json_object *md; |
| 507 | int i; |
| 508 | |
| 509 | md = json_object_new_object(); |
| 510 | |
| 511 | for (i = 0; i < ctx->n_configs; i++) { |
| 512 | struct config *config = &ctx->configs[i]; |
| 513 | json_object_object_add(md, config->name, |
| 514 | config->metadata); |
| 515 | } |
| 516 | |
| 517 | puts(json_object_get_string(md)); |
| 518 | |
| 519 | json_object_put(md); |
| 520 | } |
| 521 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 522 | static void config_free_one(struct config *config) |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 523 | { |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 524 | if (config->metadata) |
| 525 | json_object_put(config->metadata); |
| 526 | free(config->nbd_device); |
| 527 | free(config->name); |
| 528 | } |
| 529 | |
| 530 | static int config_parse_one(struct config *config, const char *name, |
| 531 | json_object *obj) |
| 532 | { |
| 533 | struct json_object *tmp, *meta; |
| 534 | json_bool jrc; |
| 535 | |
| 536 | jrc = json_object_object_get_ex(obj, "nbd-device", &tmp); |
| 537 | if (!jrc) { |
| 538 | warnx("config %s doesn't specify a nbd-device", name); |
| 539 | return -1; |
| 540 | } |
| 541 | |
| 542 | if (!json_object_is_type(tmp, json_type_string)) { |
| 543 | warnx("config %s has invalid nbd-device", name); |
| 544 | return -1; |
| 545 | } |
| 546 | |
| 547 | config->nbd_device = strdup(json_object_get_string(tmp)); |
| 548 | config->name = strdup(name); |
| 549 | |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 550 | jrc = json_object_object_get_ex(obj, "default", &tmp); |
| 551 | config->is_default = jrc && json_object_get_boolean(tmp); |
| 552 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 553 | jrc = json_object_object_get_ex(obj, "metadata", &meta); |
| 554 | if (jrc && json_object_is_type(meta, json_type_object)) |
| 555 | config->metadata = json_object_get(meta); |
| 556 | else |
| 557 | config->metadata = NULL; |
| 558 | |
| 559 | return 0; |
| 560 | } |
| 561 | |
| 562 | static void config_free(struct ctx *ctx) |
| 563 | { |
| 564 | int i; |
| 565 | |
| 566 | for (i = 0; i < ctx->n_configs; i++) |
| 567 | config_free_one(&ctx->configs[i]); |
| 568 | |
| 569 | free(ctx->configs); |
| 570 | ctx->n_configs = 0; |
| 571 | } |
| 572 | |
| 573 | static int config_init(struct ctx *ctx) |
| 574 | { |
| 575 | struct json_object *obj, *tmp; |
| 576 | json_bool jrc; |
| 577 | int i, rc; |
| 578 | |
| 579 | /* apply defaults */ |
| 580 | ctx->nbd_timeout = nbd_timeout_default; |
| 581 | |
| 582 | obj = json_object_from_file(conf_path); |
| 583 | if (!obj) { |
| 584 | warnx("can't read configuration from %s\n", conf_path); |
| 585 | return -1; |
| 586 | } |
| 587 | |
| 588 | /* global configuration */ |
| 589 | jrc = json_object_object_get_ex(obj, "timeout", &tmp); |
| 590 | if (jrc) { |
| 591 | errno = 0; |
| 592 | ctx->nbd_timeout = json_object_get_int(tmp); |
| 593 | if (ctx->nbd_timeout == 0 && errno) { |
| 594 | warnx("can't parse timeout value"); |
| 595 | goto err_free; |
| 596 | } |
| 597 | } |
| 598 | |
| 599 | /* per-config configuration */ |
| 600 | jrc = json_object_object_get_ex(obj, "configurations", &tmp); |
| 601 | if (!jrc) { |
| 602 | warnx("no configurations specified"); |
| 603 | goto err_free; |
| 604 | } |
| 605 | |
| 606 | if (!json_object_is_type(tmp, json_type_object)) { |
| 607 | warnx("invalid configurations format"); |
| 608 | goto err_free; |
| 609 | } |
| 610 | |
| 611 | ctx->n_configs = json_object_object_length(tmp); |
| 612 | ctx->configs = calloc(ctx->n_configs, sizeof(*ctx->configs)); |
| 613 | |
| 614 | i = 0; |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 615 | json_object_object_foreach(tmp, name, config_json) { |
| 616 | struct config *config = &ctx->configs[i]; |
| 617 | |
| 618 | rc = config_parse_one(config, name, config_json); |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 619 | if (rc) |
| 620 | goto err_free; |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 621 | |
| 622 | if (config->is_default) { |
| 623 | if (ctx->default_config) { |
| 624 | warn("multiple configs flagged as default"); |
| 625 | goto err_free; |
| 626 | } |
| 627 | ctx->default_config = config; |
| 628 | } |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 629 | i++; |
| 630 | } |
| 631 | |
| 632 | json_object_put(obj); |
| 633 | |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 634 | if (ctx->n_configs == 1) |
| 635 | ctx->default_config = &ctx->configs[0]; |
| 636 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 637 | return 0; |
| 638 | |
| 639 | err_free: |
| 640 | warnx("failed to load config from %s", conf_path); |
| 641 | json_object_put(obj); |
| 642 | return -1; |
| 643 | } |
| 644 | |
| 645 | static int config_select(struct ctx *ctx, const char *name) |
| 646 | { |
| 647 | struct config *config; |
| 648 | int i; |
| 649 | |
| 650 | config = NULL; |
| 651 | |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 652 | if (!name) { |
| 653 | /* no config specified: use the default */ |
| 654 | if (!ctx->default_config) { |
| 655 | warnx("no config specified, and no default"); |
| 656 | return -1; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 657 | } |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 658 | config = ctx->default_config; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 659 | |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 660 | } else { |
| 661 | /* find a matching config... */ |
| 662 | for (i = 0; i < ctx->n_configs; i++) { |
| 663 | if (!strcmp(ctx->configs[i].name, name)) { |
| 664 | config = &ctx->configs[i]; |
| 665 | break; |
| 666 | } |
| 667 | } |
| 668 | |
| 669 | if (!config) { |
| 670 | warnx("no such configuration '%s'", name); |
| 671 | return -1; |
| 672 | } |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 673 | } |
| 674 | |
| 675 | /* ... and apply it */ |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 676 | ctx->config = config; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 677 | return 0; |
| 678 | } |
| 679 | |
Jeremy Kerr | 6f9c433 | 2018-08-03 17:11:15 +0800 | [diff] [blame] | 680 | static const struct option options[] = { |
Jeremy Kerr | 13bb28f | 2018-08-09 10:41:10 +0800 | [diff] [blame] | 681 | { .name = "help", .val = 'h' }, |
| 682 | { .name = "metadata", .val = 'm' }, |
Jeremy Kerr | 6f9c433 | 2018-08-03 17:11:15 +0800 | [diff] [blame] | 683 | { 0 }, |
| 684 | }; |
| 685 | |
Jeremy Kerr | 13bb28f | 2018-08-09 10:41:10 +0800 | [diff] [blame] | 686 | enum action { |
| 687 | ACTION_PROXY, |
| 688 | ACTION_METADATA, |
| 689 | }; |
| 690 | |
Jeremy Kerr | 6f9c433 | 2018-08-03 17:11:15 +0800 | [diff] [blame] | 691 | static void print_usage(const char *progname) |
| 692 | { |
Jeremy Kerr | 13bb28f | 2018-08-09 10:41:10 +0800 | [diff] [blame] | 693 | fprintf(stderr, "usage:\n"); |
| 694 | fprintf(stderr, "\t%s [configuration]\n", progname); |
| 695 | fprintf(stderr, "\t%s --metadata\n", progname); |
Jeremy Kerr | 6f9c433 | 2018-08-03 17:11:15 +0800 | [diff] [blame] | 696 | } |
| 697 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 698 | int main(int argc, char **argv) |
| 699 | { |
Jeremy Kerr | 13bb28f | 2018-08-09 10:41:10 +0800 | [diff] [blame] | 700 | enum action action = ACTION_PROXY; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 701 | const char *config_name; |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 702 | struct ctx _ctx, *ctx; |
| 703 | int rc; |
| 704 | |
Jeremy Kerr | 0f1a49c | 2018-08-03 15:41:38 +0800 | [diff] [blame] | 705 | config_name = NULL; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 706 | |
Jeremy Kerr | 6f9c433 | 2018-08-03 17:11:15 +0800 | [diff] [blame] | 707 | for (;;) { |
| 708 | int c = getopt_long(argc, argv, "h", options, NULL); |
| 709 | if (c == -1) |
| 710 | break; |
| 711 | |
| 712 | switch (c) { |
Jeremy Kerr | 13bb28f | 2018-08-09 10:41:10 +0800 | [diff] [blame] | 713 | case 'm': |
| 714 | action = ACTION_METADATA; |
| 715 | break; |
Jeremy Kerr | 6f9c433 | 2018-08-03 17:11:15 +0800 | [diff] [blame] | 716 | case 'h': |
| 717 | case '?': |
| 718 | print_usage(argv[0]); |
| 719 | return c == 'h' ? EXIT_SUCCESS : EXIT_FAILURE; |
| 720 | } |
| 721 | } |
| 722 | |
| 723 | if (optind < argc) |
| 724 | config_name = argv[optind]; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 725 | |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 726 | ctx = &_ctx; |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 727 | memset(ctx, 0, sizeof(*ctx)); |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 728 | ctx->bufsize = bufsize; |
| 729 | ctx->buf = malloc(ctx->bufsize); |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 730 | |
| 731 | rc = config_init(ctx); |
| 732 | if (rc) |
| 733 | goto out_free; |
| 734 | |
Jeremy Kerr | 13bb28f | 2018-08-09 10:41:10 +0800 | [diff] [blame] | 735 | if (action == ACTION_METADATA) { |
| 736 | print_metadata(ctx); |
| 737 | goto out_free; |
| 738 | } |
| 739 | |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 740 | rc = config_select(ctx, config_name); |
| 741 | if (rc) |
| 742 | goto out_free; |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 743 | |
| 744 | rc = open_nbd_socket(ctx); |
| 745 | if (rc) |
| 746 | goto out_free; |
| 747 | |
| 748 | rc = setup_signals(ctx); |
| 749 | if (rc) |
| 750 | goto out_close; |
| 751 | |
| 752 | rc = start_nbd_client(ctx); |
| 753 | if (rc) |
| 754 | goto out_stop_client; |
| 755 | |
| 756 | rc = wait_for_nbd_client(ctx); |
| 757 | if (rc) |
| 758 | goto out_stop_client; |
| 759 | |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 760 | rc = run_state_hooks(ctx, "start"); |
| 761 | if (rc) |
| 762 | goto out_stop_client; |
| 763 | |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 764 | rc = run_proxy(ctx); |
| 765 | |
Jeremy Kerr | c6134c1 | 2018-08-09 13:03:33 +0800 | [diff] [blame^] | 766 | run_state_hooks(ctx, "stop"); |
| 767 | |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 768 | out_stop_client: |
| 769 | /* we cleanup signals before stopping the client, because we |
| 770 | * no longer care about SIGCHLD from the stopping nbd-client |
| 771 | * process. stop_nbd_client will be a no-op if the client hasn't |
| 772 | * been started. */ |
| 773 | cleanup_signals(ctx); |
| 774 | |
| 775 | stop_nbd_client(ctx); |
| 776 | close(ctx->sock_client); |
| 777 | |
| 778 | out_close: |
| 779 | if (ctx->sock_path) { |
| 780 | unlink(ctx->sock_path); |
| 781 | free(ctx->sock_path); |
| 782 | } |
| 783 | close(ctx->sock); |
| 784 | out_free: |
Jeremy Kerr | 1952735 | 2018-08-03 15:04:38 +0800 | [diff] [blame] | 785 | config_free(ctx); |
Jeremy Kerr | f403c42 | 2018-07-26 12:14:56 +0800 | [diff] [blame] | 786 | free(ctx->buf); |
| 787 | return rc ? EXIT_FAILURE : EXIT_SUCCESS; |
| 788 | } |