| 1 | /* |
| 2 | * Copyright (C) 2012 David Goulet <dgoulet@efficios.com> |
| 3 | * Copyright (C) 2013 Raphaël Beamonte <raphael.beamonte@gmail.com> |
| 4 | * Copyright (C) 2013 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 5 | * |
| 6 | * SPDX-License-Identifier: GPL-2.0-only |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | #include "common/macros.h" |
| 11 | #define _LGPL_SOURCE |
| 12 | #include <assert.h> |
| 13 | #include <ctype.h> |
| 14 | #include <fcntl.h> |
| 15 | #include <limits.h> |
| 16 | #include <stdlib.h> |
| 17 | #include <sys/stat.h> |
| 18 | #include <sys/types.h> |
| 19 | #include <unistd.h> |
| 20 | #include <inttypes.h> |
| 21 | #include <grp.h> |
| 22 | #include <pwd.h> |
| 23 | #include <sys/file.h> |
| 24 | #include <unistd.h> |
| 25 | |
| 26 | #include <common/common.h> |
| 27 | #include <common/readwrite.h> |
| 28 | #include <common/runas.h> |
| 29 | #include <common/compat/getenv.h> |
| 30 | #include <common/compat/string.h> |
| 31 | #include <common/compat/dirent.h> |
| 32 | #include <common/compat/directory-handle.h> |
| 33 | #include <common/dynamic-buffer.h> |
| 34 | #include <common/string-utils/format.h> |
| 35 | #include <lttng/constant.h> |
| 36 | |
| 37 | #include "utils.h" |
| 38 | #include "defaults.h" |
| 39 | #include "time.h" |
| 40 | |
| 41 | #define PROC_MEMINFO_PATH "/proc/meminfo" |
| 42 | #define PROC_MEMINFO_MEMAVAILABLE_LINE "MemAvailable:" |
| 43 | #define PROC_MEMINFO_MEMTOTAL_LINE "MemTotal:" |
| 44 | |
| 45 | /* The length of the longest field of `/proc/meminfo`. */ |
| 46 | #define PROC_MEMINFO_FIELD_MAX_NAME_LEN 20 |
| 47 | |
| 48 | #if (PROC_MEMINFO_FIELD_MAX_NAME_LEN == 20) |
| 49 | #define MAX_NAME_LEN_SCANF_IS_A_BROKEN_API "19" |
| 50 | #else |
| 51 | #error MAX_NAME_LEN_SCANF_IS_A_BROKEN_API must be updated to match (PROC_MEMINFO_FIELD_MAX_NAME_LEN - 1) |
| 52 | #endif |
| 53 | |
| 54 | #define FALLBACK_USER_BUFLEN 16384 |
| 55 | #define FALLBACK_GROUP_BUFLEN 16384 |
| 56 | |
| 57 | /* |
| 58 | * Return a partial realpath(3) of the path even if the full path does not |
| 59 | * exist. For instance, with /tmp/test1/test2/test3, if test2/ does not exist |
| 60 | * but the /tmp/test1 does, the real path for /tmp/test1 is concatened with |
| 61 | * /test2/test3 then returned. In normal time, realpath(3) fails if the end |
| 62 | * point directory does not exist. |
| 63 | * In case resolved_path is NULL, the string returned was allocated in the |
| 64 | * function and thus need to be freed by the caller. The size argument allows |
| 65 | * to specify the size of the resolved_path argument if given, or the size to |
| 66 | * allocate. |
| 67 | */ |
| 68 | LTTNG_HIDDEN |
| 69 | char *utils_partial_realpath(const char *path, char *resolved_path, size_t size) |
| 70 | { |
| 71 | char *cut_path = NULL, *try_path = NULL, *try_path_prev = NULL; |
| 72 | const char *next, *prev, *end; |
| 73 | |
| 74 | /* Safety net */ |
| 75 | if (path == NULL) { |
| 76 | goto error; |
| 77 | } |
| 78 | |
| 79 | /* |
| 80 | * Identify the end of the path, we don't want to treat the |
| 81 | * last char if it is a '/', we will just keep it on the side |
| 82 | * to be added at the end, and return a value coherent with |
| 83 | * the path given as argument |
| 84 | */ |
| 85 | end = path + strlen(path); |
| 86 | if (*(end-1) == '/') { |
| 87 | end--; |
| 88 | } |
| 89 | |
| 90 | /* Initiate the values of the pointers before looping */ |
| 91 | next = path; |
| 92 | prev = next; |
| 93 | /* Only to ensure try_path is not NULL to enter the while */ |
| 94 | try_path = (char *)next; |
| 95 | |
| 96 | /* Resolve the canonical path of the first part of the path */ |
| 97 | while (try_path != NULL && next != end) { |
| 98 | char *try_path_buf = NULL; |
| 99 | |
| 100 | /* |
| 101 | * If there is not any '/' left, we want to try with |
| 102 | * the full path |
| 103 | */ |
| 104 | next = strpbrk(next + 1, "/"); |
| 105 | if (next == NULL) { |
| 106 | next = end; |
| 107 | } |
| 108 | |
| 109 | /* Cut the part we will be trying to resolve */ |
| 110 | cut_path = lttng_strndup(path, next - path); |
| 111 | if (cut_path == NULL) { |
| 112 | PERROR("lttng_strndup"); |
| 113 | goto error; |
| 114 | } |
| 115 | |
| 116 | try_path_buf = zmalloc(LTTNG_PATH_MAX); |
| 117 | if (!try_path_buf) { |
| 118 | PERROR("zmalloc"); |
| 119 | goto error; |
| 120 | } |
| 121 | |
| 122 | /* Try to resolve this part */ |
| 123 | try_path = realpath((char *) cut_path, try_path_buf); |
| 124 | if (try_path == NULL) { |
| 125 | free(try_path_buf); |
| 126 | /* |
| 127 | * There was an error, we just want to be assured it |
| 128 | * is linked to an unexistent directory, if it's another |
| 129 | * reason, we spawn an error |
| 130 | */ |
| 131 | switch (errno) { |
| 132 | case ENOENT: |
| 133 | /* Ignore the error */ |
| 134 | break; |
| 135 | default: |
| 136 | PERROR("realpath (partial_realpath)"); |
| 137 | goto error; |
| 138 | break; |
| 139 | } |
| 140 | } else { |
| 141 | /* Save the place we are before trying the next step */ |
| 142 | try_path_buf = NULL; |
| 143 | free(try_path_prev); |
| 144 | try_path_prev = try_path; |
| 145 | prev = next; |
| 146 | } |
| 147 | |
| 148 | /* Free the allocated memory */ |
| 149 | free(cut_path); |
| 150 | cut_path = NULL; |
| 151 | } |
| 152 | |
| 153 | /* Allocate memory for the resolved path if necessary */ |
| 154 | if (resolved_path == NULL) { |
| 155 | resolved_path = zmalloc(size); |
| 156 | if (resolved_path == NULL) { |
| 157 | PERROR("zmalloc resolved path"); |
| 158 | goto error; |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | /* |
| 163 | * If we were able to solve at least partially the path, we can concatenate |
| 164 | * what worked and what didn't work |
| 165 | */ |
| 166 | if (try_path_prev != NULL) { |
| 167 | /* If we risk to concatenate two '/', we remove one of them */ |
| 168 | if (try_path_prev[strlen(try_path_prev) - 1] == '/' && prev[0] == '/') { |
| 169 | try_path_prev[strlen(try_path_prev) - 1] = '\0'; |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * Duplicate the memory used by prev in case resolved_path and |
| 174 | * path are pointers for the same memory space |
| 175 | */ |
| 176 | cut_path = strdup(prev); |
| 177 | if (cut_path == NULL) { |
| 178 | PERROR("strdup"); |
| 179 | goto error; |
| 180 | } |
| 181 | |
| 182 | /* Concatenate the strings */ |
| 183 | snprintf(resolved_path, size, "%s%s", try_path_prev, cut_path); |
| 184 | |
| 185 | /* Free the allocated memory */ |
| 186 | free(cut_path); |
| 187 | free(try_path_prev); |
| 188 | cut_path = NULL; |
| 189 | try_path_prev = NULL; |
| 190 | /* |
| 191 | * Else, we just copy the path in our resolved_path to |
| 192 | * return it as is |
| 193 | */ |
| 194 | } else { |
| 195 | strncpy(resolved_path, path, size); |
| 196 | } |
| 197 | |
| 198 | /* Then we return the 'partially' resolved path */ |
| 199 | return resolved_path; |
| 200 | |
| 201 | error: |
| 202 | free(resolved_path); |
| 203 | free(cut_path); |
| 204 | free(try_path); |
| 205 | if (try_path_prev != try_path) { |
| 206 | free(try_path_prev); |
| 207 | } |
| 208 | return NULL; |
| 209 | } |
| 210 | |
| 211 | static |
| 212 | int expand_double_slashes_dot_and_dotdot(char *path) |
| 213 | { |
| 214 | size_t expanded_path_len, path_len; |
| 215 | const char *curr_char, *path_last_char, *next_slash, *prev_slash; |
| 216 | |
| 217 | path_len = strlen(path); |
| 218 | path_last_char = &path[path_len]; |
| 219 | |
| 220 | if (path_len == 0) { |
| 221 | goto error; |
| 222 | } |
| 223 | |
| 224 | expanded_path_len = 0; |
| 225 | |
| 226 | /* We iterate over the provided path to expand the "//", "../" and "./" */ |
| 227 | for (curr_char = path; curr_char <= path_last_char; curr_char = next_slash + 1) { |
| 228 | /* Find the next forward slash. */ |
| 229 | size_t curr_token_len; |
| 230 | |
| 231 | if (curr_char == path_last_char) { |
| 232 | expanded_path_len++; |
| 233 | break; |
| 234 | } |
| 235 | |
| 236 | next_slash = memchr(curr_char, '/', path_last_char - curr_char); |
| 237 | if (next_slash == NULL) { |
| 238 | /* Reached the end of the provided path. */ |
| 239 | next_slash = path_last_char; |
| 240 | } |
| 241 | |
| 242 | /* Compute how long is the previous token. */ |
| 243 | curr_token_len = next_slash - curr_char; |
| 244 | switch(curr_token_len) { |
| 245 | case 0: |
| 246 | /* |
| 247 | * The pointer has not move meaning that curr_char is |
| 248 | * pointing to a slash. It that case there is no token |
| 249 | * to copy, so continue the iteration to find the next |
| 250 | * token |
| 251 | */ |
| 252 | continue; |
| 253 | case 1: |
| 254 | /* |
| 255 | * The pointer moved 1 character. Check if that |
| 256 | * character is a dot ('.'), if it is: omit it, else |
| 257 | * copy the token to the normalized path. |
| 258 | */ |
| 259 | if (curr_char[0] == '.') { |
| 260 | continue; |
| 261 | } |
| 262 | break; |
| 263 | case 2: |
| 264 | /* |
| 265 | * The pointer moved 2 characters. Check if these |
| 266 | * characters are double dots ('..'). If that is the |
| 267 | * case, we need to remove the last token of the |
| 268 | * normalized path. |
| 269 | */ |
| 270 | if (curr_char[0] == '.' && curr_char[1] == '.') { |
| 271 | /* |
| 272 | * Find the previous path component by |
| 273 | * using the memrchr function to find the |
| 274 | * previous forward slash and substract that |
| 275 | * len to the resulting path. |
| 276 | */ |
| 277 | prev_slash = lttng_memrchr(path, '/', expanded_path_len); |
| 278 | /* |
| 279 | * If prev_slash is NULL, we reached the |
| 280 | * beginning of the path. We can't go back any |
| 281 | * further. |
| 282 | */ |
| 283 | if (prev_slash != NULL) { |
| 284 | expanded_path_len = prev_slash - path; |
| 285 | } |
| 286 | continue; |
| 287 | } |
| 288 | break; |
| 289 | default: |
| 290 | break; |
| 291 | } |
| 292 | |
| 293 | /* |
| 294 | * Copy the current token which is neither a '.' nor a '..'. |
| 295 | */ |
| 296 | path[expanded_path_len++] = '/'; |
| 297 | memcpy(&path[expanded_path_len], curr_char, curr_token_len); |
| 298 | expanded_path_len += curr_token_len; |
| 299 | } |
| 300 | |
| 301 | if (expanded_path_len == 0) { |
| 302 | path[expanded_path_len++] = '/'; |
| 303 | } |
| 304 | |
| 305 | path[expanded_path_len] = '\0'; |
| 306 | return 0; |
| 307 | error: |
| 308 | return -1; |
| 309 | } |
| 310 | |
| 311 | /* |
| 312 | * Make a full resolution of the given path even if it doesn't exist. |
| 313 | * This function uses the utils_partial_realpath function to resolve |
| 314 | * symlinks and relatives paths at the start of the string, and |
| 315 | * implements functionnalities to resolve the './' and '../' strings |
| 316 | * in the middle of a path. This function is only necessary because |
| 317 | * realpath(3) does not accept to resolve unexistent paths. |
| 318 | * The returned string was allocated in the function, it is thus of |
| 319 | * the responsibility of the caller to free this memory. |
| 320 | */ |
| 321 | static |
| 322 | char *_utils_expand_path(const char *path, bool keep_symlink) |
| 323 | { |
| 324 | int ret; |
| 325 | char *absolute_path = NULL; |
| 326 | char *last_token; |
| 327 | bool is_dot, is_dotdot; |
| 328 | |
| 329 | /* Safety net */ |
| 330 | if (path == NULL) { |
| 331 | goto error; |
| 332 | } |
| 333 | |
| 334 | /* Allocate memory for the absolute_path */ |
| 335 | absolute_path = zmalloc(LTTNG_PATH_MAX); |
| 336 | if (absolute_path == NULL) { |
| 337 | PERROR("zmalloc expand path"); |
| 338 | goto error; |
| 339 | } |
| 340 | |
| 341 | if (path[0] == '/') { |
| 342 | ret = lttng_strncpy(absolute_path, path, LTTNG_PATH_MAX); |
| 343 | if (ret) { |
| 344 | ERR("Path exceeds maximal size of %i bytes", LTTNG_PATH_MAX); |
| 345 | goto error; |
| 346 | } |
| 347 | } else { |
| 348 | /* |
| 349 | * This is a relative path. We need to get the present working |
| 350 | * directory and start the path walk from there. |
| 351 | */ |
| 352 | char current_working_dir[LTTNG_PATH_MAX]; |
| 353 | char *cwd_ret; |
| 354 | |
| 355 | cwd_ret = getcwd(current_working_dir, sizeof(current_working_dir)); |
| 356 | if (!cwd_ret) { |
| 357 | goto error; |
| 358 | } |
| 359 | /* |
| 360 | * Get the number of character in the CWD and allocate an array |
| 361 | * to can hold it and the path provided by the caller. |
| 362 | */ |
| 363 | ret = snprintf(absolute_path, LTTNG_PATH_MAX, "%s/%s", |
| 364 | current_working_dir, path); |
| 365 | if (ret >= LTTNG_PATH_MAX) { |
| 366 | ERR("Concatenating current working directory %s and path %s exceeds maximal size of %i bytes", |
| 367 | current_working_dir, path, LTTNG_PATH_MAX); |
| 368 | goto error; |
| 369 | } |
| 370 | } |
| 371 | |
| 372 | if (keep_symlink) { |
| 373 | /* Resolve partially our path */ |
| 374 | absolute_path = utils_partial_realpath(absolute_path, |
| 375 | absolute_path, LTTNG_PATH_MAX); |
| 376 | if (!absolute_path) { |
| 377 | goto error; |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | ret = expand_double_slashes_dot_and_dotdot(absolute_path); |
| 382 | if (ret) { |
| 383 | goto error; |
| 384 | } |
| 385 | |
| 386 | /* Identify the last token */ |
| 387 | last_token = strrchr(absolute_path, '/'); |
| 388 | |
| 389 | /* Verify that this token is not a relative path */ |
| 390 | is_dotdot = (strcmp(last_token, "/..") == 0); |
| 391 | is_dot = (strcmp(last_token, "/.") == 0); |
| 392 | |
| 393 | /* If it is, take action */ |
| 394 | if (is_dot || is_dotdot) { |
| 395 | /* For both, remove this token */ |
| 396 | *last_token = '\0'; |
| 397 | |
| 398 | /* If it was a reference to parent directory, go back one more time */ |
| 399 | if (is_dotdot) { |
| 400 | last_token = strrchr(absolute_path, '/'); |
| 401 | |
| 402 | /* If there was only one level left, we keep the first '/' */ |
| 403 | if (last_token == absolute_path) { |
| 404 | last_token++; |
| 405 | } |
| 406 | |
| 407 | *last_token = '\0'; |
| 408 | } |
| 409 | } |
| 410 | |
| 411 | return absolute_path; |
| 412 | |
| 413 | error: |
| 414 | free(absolute_path); |
| 415 | return NULL; |
| 416 | } |
| 417 | LTTNG_HIDDEN |
| 418 | char *utils_expand_path(const char *path) |
| 419 | { |
| 420 | return _utils_expand_path(path, true); |
| 421 | } |
| 422 | |
| 423 | LTTNG_HIDDEN |
| 424 | char *utils_expand_path_keep_symlink(const char *path) |
| 425 | { |
| 426 | return _utils_expand_path(path, false); |
| 427 | } |
| 428 | /* |
| 429 | * Create a pipe in dst. |
| 430 | */ |
| 431 | LTTNG_HIDDEN |
| 432 | int utils_create_pipe(int *dst) |
| 433 | { |
| 434 | int ret; |
| 435 | |
| 436 | if (dst == NULL) { |
| 437 | return -1; |
| 438 | } |
| 439 | |
| 440 | ret = pipe(dst); |
| 441 | if (ret < 0) { |
| 442 | PERROR("create pipe"); |
| 443 | } |
| 444 | |
| 445 | return ret; |
| 446 | } |
| 447 | |
| 448 | /* |
| 449 | * Create pipe and set CLOEXEC flag to both fd. |
| 450 | * |
| 451 | * Make sure the pipe opened by this function are closed at some point. Use |
| 452 | * utils_close_pipe(). |
| 453 | */ |
| 454 | LTTNG_HIDDEN |
| 455 | int utils_create_pipe_cloexec(int *dst) |
| 456 | { |
| 457 | int ret, i; |
| 458 | |
| 459 | if (dst == NULL) { |
| 460 | return -1; |
| 461 | } |
| 462 | |
| 463 | ret = utils_create_pipe(dst); |
| 464 | if (ret < 0) { |
| 465 | goto error; |
| 466 | } |
| 467 | |
| 468 | for (i = 0; i < 2; i++) { |
| 469 | ret = fcntl(dst[i], F_SETFD, FD_CLOEXEC); |
| 470 | if (ret < 0) { |
| 471 | PERROR("fcntl pipe cloexec"); |
| 472 | goto error; |
| 473 | } |
| 474 | } |
| 475 | |
| 476 | error: |
| 477 | return ret; |
| 478 | } |
| 479 | |
| 480 | /* |
| 481 | * Create pipe and set fd flags to FD_CLOEXEC and O_NONBLOCK. |
| 482 | * |
| 483 | * Make sure the pipe opened by this function are closed at some point. Use |
| 484 | * utils_close_pipe(). Using pipe() and fcntl rather than pipe2() to |
| 485 | * support OSes other than Linux 2.6.23+. |
| 486 | */ |
| 487 | LTTNG_HIDDEN |
| 488 | int utils_create_pipe_cloexec_nonblock(int *dst) |
| 489 | { |
| 490 | int ret, i; |
| 491 | |
| 492 | if (dst == NULL) { |
| 493 | return -1; |
| 494 | } |
| 495 | |
| 496 | ret = utils_create_pipe(dst); |
| 497 | if (ret < 0) { |
| 498 | goto error; |
| 499 | } |
| 500 | |
| 501 | for (i = 0; i < 2; i++) { |
| 502 | ret = fcntl(dst[i], F_SETFD, FD_CLOEXEC); |
| 503 | if (ret < 0) { |
| 504 | PERROR("fcntl pipe cloexec"); |
| 505 | goto error; |
| 506 | } |
| 507 | /* |
| 508 | * Note: we override any flag that could have been |
| 509 | * previously set on the fd. |
| 510 | */ |
| 511 | ret = fcntl(dst[i], F_SETFL, O_NONBLOCK); |
| 512 | if (ret < 0) { |
| 513 | PERROR("fcntl pipe nonblock"); |
| 514 | goto error; |
| 515 | } |
| 516 | } |
| 517 | |
| 518 | error: |
| 519 | return ret; |
| 520 | } |
| 521 | |
| 522 | /* |
| 523 | * Close both read and write side of the pipe. |
| 524 | */ |
| 525 | LTTNG_HIDDEN |
| 526 | void utils_close_pipe(int *src) |
| 527 | { |
| 528 | int i, ret; |
| 529 | |
| 530 | if (src == NULL) { |
| 531 | return; |
| 532 | } |
| 533 | |
| 534 | for (i = 0; i < 2; i++) { |
| 535 | /* Safety check */ |
| 536 | if (src[i] < 0) { |
| 537 | continue; |
| 538 | } |
| 539 | |
| 540 | ret = close(src[i]); |
| 541 | if (ret) { |
| 542 | PERROR("close pipe"); |
| 543 | } |
| 544 | src[i] = -1; |
| 545 | } |
| 546 | } |
| 547 | |
| 548 | /* |
| 549 | * Create a new string using two strings range. |
| 550 | */ |
| 551 | LTTNG_HIDDEN |
| 552 | char *utils_strdupdelim(const char *begin, const char *end) |
| 553 | { |
| 554 | char *str; |
| 555 | |
| 556 | str = zmalloc(end - begin + 1); |
| 557 | if (str == NULL) { |
| 558 | PERROR("zmalloc strdupdelim"); |
| 559 | goto error; |
| 560 | } |
| 561 | |
| 562 | memcpy(str, begin, end - begin); |
| 563 | str[end - begin] = '\0'; |
| 564 | |
| 565 | error: |
| 566 | return str; |
| 567 | } |
| 568 | |
| 569 | /* |
| 570 | * Set CLOEXEC flag to the give file descriptor. |
| 571 | */ |
| 572 | LTTNG_HIDDEN |
| 573 | int utils_set_fd_cloexec(int fd) |
| 574 | { |
| 575 | int ret; |
| 576 | |
| 577 | if (fd < 0) { |
| 578 | ret = -EINVAL; |
| 579 | goto end; |
| 580 | } |
| 581 | |
| 582 | ret = fcntl(fd, F_SETFD, FD_CLOEXEC); |
| 583 | if (ret < 0) { |
| 584 | PERROR("fcntl cloexec"); |
| 585 | ret = -errno; |
| 586 | } |
| 587 | |
| 588 | end: |
| 589 | return ret; |
| 590 | } |
| 591 | |
| 592 | /* |
| 593 | * Create pid file to the given path and filename. |
| 594 | */ |
| 595 | LTTNG_HIDDEN |
| 596 | int utils_create_pid_file(pid_t pid, const char *filepath) |
| 597 | { |
| 598 | int ret; |
| 599 | FILE *fp; |
| 600 | |
| 601 | assert(filepath); |
| 602 | |
| 603 | fp = fopen(filepath, "w"); |
| 604 | if (fp == NULL) { |
| 605 | PERROR("open pid file %s", filepath); |
| 606 | ret = -1; |
| 607 | goto error; |
| 608 | } |
| 609 | |
| 610 | ret = fprintf(fp, "%d\n", (int) pid); |
| 611 | if (ret < 0) { |
| 612 | PERROR("fprintf pid file"); |
| 613 | goto error; |
| 614 | } |
| 615 | |
| 616 | if (fclose(fp)) { |
| 617 | PERROR("fclose"); |
| 618 | } |
| 619 | DBG("Pid %d written in file %s", (int) pid, filepath); |
| 620 | ret = 0; |
| 621 | error: |
| 622 | return ret; |
| 623 | } |
| 624 | |
| 625 | /* |
| 626 | * Create lock file to the given path and filename. |
| 627 | * Returns the associated file descriptor, -1 on error. |
| 628 | */ |
| 629 | LTTNG_HIDDEN |
| 630 | int utils_create_lock_file(const char *filepath) |
| 631 | { |
| 632 | int ret; |
| 633 | int fd; |
| 634 | struct flock lock; |
| 635 | |
| 636 | assert(filepath); |
| 637 | |
| 638 | memset(&lock, 0, sizeof(lock)); |
| 639 | fd = open(filepath, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR | |
| 640 | S_IRGRP | S_IWGRP); |
| 641 | if (fd < 0) { |
| 642 | PERROR("open lock file %s", filepath); |
| 643 | fd = -1; |
| 644 | goto error; |
| 645 | } |
| 646 | |
| 647 | /* |
| 648 | * Attempt to lock the file. If this fails, there is |
| 649 | * already a process using the same lock file running |
| 650 | * and we should exit. |
| 651 | */ |
| 652 | lock.l_whence = SEEK_SET; |
| 653 | lock.l_type = F_WRLCK; |
| 654 | |
| 655 | ret = fcntl(fd, F_SETLK, &lock); |
| 656 | if (ret == -1) { |
| 657 | PERROR("fcntl lock file"); |
| 658 | ERR("Could not get lock file %s, another instance is running.", |
| 659 | filepath); |
| 660 | if (close(fd)) { |
| 661 | PERROR("close lock file"); |
| 662 | } |
| 663 | fd = ret; |
| 664 | goto error; |
| 665 | } |
| 666 | |
| 667 | error: |
| 668 | return fd; |
| 669 | } |
| 670 | |
| 671 | /* |
| 672 | * Create directory using the given path and mode. |
| 673 | * |
| 674 | * On success, return 0 else a negative error code. |
| 675 | */ |
| 676 | LTTNG_HIDDEN |
| 677 | int utils_mkdir(const char *path, mode_t mode, int uid, int gid) |
| 678 | { |
| 679 | int ret; |
| 680 | struct lttng_directory_handle *handle; |
| 681 | const struct lttng_credentials creds = { |
| 682 | .uid = (uid_t) uid, |
| 683 | .gid = (gid_t) gid, |
| 684 | }; |
| 685 | |
| 686 | handle = lttng_directory_handle_create(NULL); |
| 687 | if (!handle) { |
| 688 | ret = -1; |
| 689 | goto end; |
| 690 | } |
| 691 | ret = lttng_directory_handle_create_subdirectory_as_user( |
| 692 | handle, path, mode, |
| 693 | (uid >= 0 || gid >= 0) ? &creds : NULL); |
| 694 | end: |
| 695 | lttng_directory_handle_put(handle); |
| 696 | return ret; |
| 697 | } |
| 698 | |
| 699 | /* |
| 700 | * Recursively create directory using the given path and mode, under the |
| 701 | * provided uid and gid. |
| 702 | * |
| 703 | * On success, return 0 else a negative error code. |
| 704 | */ |
| 705 | LTTNG_HIDDEN |
| 706 | int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid) |
| 707 | { |
| 708 | int ret; |
| 709 | struct lttng_directory_handle *handle; |
| 710 | const struct lttng_credentials creds = { |
| 711 | .uid = (uid_t) uid, |
| 712 | .gid = (gid_t) gid, |
| 713 | }; |
| 714 | |
| 715 | handle = lttng_directory_handle_create(NULL); |
| 716 | if (!handle) { |
| 717 | ret = -1; |
| 718 | goto end; |
| 719 | } |
| 720 | ret = lttng_directory_handle_create_subdirectory_recursive_as_user( |
| 721 | handle, path, mode, |
| 722 | (uid >= 0 || gid >= 0) ? &creds : NULL); |
| 723 | end: |
| 724 | lttng_directory_handle_put(handle); |
| 725 | return ret; |
| 726 | } |
| 727 | |
| 728 | /* |
| 729 | * out_stream_path is the output parameter. |
| 730 | * |
| 731 | * Return 0 on success or else a negative value. |
| 732 | */ |
| 733 | LTTNG_HIDDEN |
| 734 | int utils_stream_file_path(const char *path_name, const char *file_name, |
| 735 | uint64_t size, uint64_t count, const char *suffix, |
| 736 | char *out_stream_path, size_t stream_path_len) |
| 737 | { |
| 738 | int ret; |
| 739 | char count_str[MAX_INT_DEC_LEN(count) + 1] = {}; |
| 740 | const char *path_separator; |
| 741 | |
| 742 | if (path_name && (path_name[0] == '\0' || |
| 743 | path_name[strlen(path_name) - 1] == '/')) { |
| 744 | path_separator = ""; |
| 745 | } else { |
| 746 | path_separator = "/"; |
| 747 | } |
| 748 | |
| 749 | path_name = path_name ? : ""; |
| 750 | suffix = suffix ? : ""; |
| 751 | if (size > 0) { |
| 752 | ret = snprintf(count_str, sizeof(count_str), "_%" PRIu64, |
| 753 | count); |
| 754 | assert(ret > 0 && ret < sizeof(count_str)); |
| 755 | } |
| 756 | |
| 757 | ret = snprintf(out_stream_path, stream_path_len, "%s%s%s%s%s", |
| 758 | path_name, path_separator, file_name, count_str, |
| 759 | suffix); |
| 760 | if (ret < 0 || ret >= stream_path_len) { |
| 761 | ERR("Truncation occurred while formatting stream path"); |
| 762 | ret = -1; |
| 763 | } else { |
| 764 | ret = 0; |
| 765 | } |
| 766 | return ret; |
| 767 | } |
| 768 | |
| 769 | /** |
| 770 | * Parse a string that represents a size in human readable format. It |
| 771 | * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'. |
| 772 | * |
| 773 | * The suffix multiply the integer by: |
| 774 | * 'k': 1024 |
| 775 | * 'M': 1024^2 |
| 776 | * 'G': 1024^3 |
| 777 | * |
| 778 | * @param str The string to parse. |
| 779 | * @param size Pointer to a uint64_t that will be filled with the |
| 780 | * resulting size. |
| 781 | * |
| 782 | * @return 0 on success, -1 on failure. |
| 783 | */ |
| 784 | LTTNG_HIDDEN |
| 785 | int utils_parse_size_suffix(const char * const str, uint64_t * const size) |
| 786 | { |
| 787 | int ret; |
| 788 | uint64_t base_size; |
| 789 | long shift = 0; |
| 790 | const char *str_end; |
| 791 | char *num_end; |
| 792 | |
| 793 | if (!str) { |
| 794 | DBG("utils_parse_size_suffix: received a NULL string."); |
| 795 | ret = -1; |
| 796 | goto end; |
| 797 | } |
| 798 | |
| 799 | /* strtoull will accept a negative number, but we don't want to. */ |
| 800 | if (strchr(str, '-') != NULL) { |
| 801 | DBG("utils_parse_size_suffix: invalid size string, should not contain '-'."); |
| 802 | ret = -1; |
| 803 | goto end; |
| 804 | } |
| 805 | |
| 806 | /* str_end will point to the \0 */ |
| 807 | str_end = str + strlen(str); |
| 808 | errno = 0; |
| 809 | base_size = strtoull(str, &num_end, 0); |
| 810 | if (errno != 0) { |
| 811 | PERROR("utils_parse_size_suffix strtoull"); |
| 812 | ret = -1; |
| 813 | goto end; |
| 814 | } |
| 815 | |
| 816 | if (num_end == str) { |
| 817 | /* strtoull parsed nothing, not good. */ |
| 818 | DBG("utils_parse_size_suffix: strtoull had nothing good to parse."); |
| 819 | ret = -1; |
| 820 | goto end; |
| 821 | } |
| 822 | |
| 823 | /* Check if a prefix is present. */ |
| 824 | switch (*num_end) { |
| 825 | case 'G': |
| 826 | shift = GIBI_LOG2; |
| 827 | num_end++; |
| 828 | break; |
| 829 | case 'M': /* */ |
| 830 | shift = MEBI_LOG2; |
| 831 | num_end++; |
| 832 | break; |
| 833 | case 'K': |
| 834 | case 'k': |
| 835 | shift = KIBI_LOG2; |
| 836 | num_end++; |
| 837 | break; |
| 838 | case '\0': |
| 839 | break; |
| 840 | default: |
| 841 | DBG("utils_parse_size_suffix: invalid suffix."); |
| 842 | ret = -1; |
| 843 | goto end; |
| 844 | } |
| 845 | |
| 846 | /* Check for garbage after the valid input. */ |
| 847 | if (num_end != str_end) { |
| 848 | DBG("utils_parse_size_suffix: Garbage after size string."); |
| 849 | ret = -1; |
| 850 | goto end; |
| 851 | } |
| 852 | |
| 853 | *size = base_size << shift; |
| 854 | |
| 855 | /* Check for overflow */ |
| 856 | if ((*size >> shift) != base_size) { |
| 857 | DBG("utils_parse_size_suffix: oops, overflow detected."); |
| 858 | ret = -1; |
| 859 | goto end; |
| 860 | } |
| 861 | |
| 862 | ret = 0; |
| 863 | end: |
| 864 | return ret; |
| 865 | } |
| 866 | |
| 867 | /** |
| 868 | * Parse a string that represents a time in human readable format. It |
| 869 | * supports decimal integers suffixed by: |
| 870 | * "us" for microsecond, |
| 871 | * "ms" for millisecond, |
| 872 | * "s" for second, |
| 873 | * "m" for minute, |
| 874 | * "h" for hour |
| 875 | * |
| 876 | * The suffix multiply the integer by: |
| 877 | * "us" : 1 |
| 878 | * "ms" : 1000 |
| 879 | * "s" : 1000000 |
| 880 | * "m" : 60000000 |
| 881 | * "h" : 3600000000 |
| 882 | * |
| 883 | * Note that unit-less numbers are assumed to be microseconds. |
| 884 | * |
| 885 | * @param str The string to parse, assumed to be NULL-terminated. |
| 886 | * @param time_us Pointer to a uint64_t that will be filled with the |
| 887 | * resulting time in microseconds. |
| 888 | * |
| 889 | * @return 0 on success, -1 on failure. |
| 890 | */ |
| 891 | LTTNG_HIDDEN |
| 892 | int utils_parse_time_suffix(char const * const str, uint64_t * const time_us) |
| 893 | { |
| 894 | int ret; |
| 895 | uint64_t base_time; |
| 896 | uint64_t multiplier = 1; |
| 897 | const char *str_end; |
| 898 | char *num_end; |
| 899 | |
| 900 | if (!str) { |
| 901 | DBG("utils_parse_time_suffix: received a NULL string."); |
| 902 | ret = -1; |
| 903 | goto end; |
| 904 | } |
| 905 | |
| 906 | /* strtoull will accept a negative number, but we don't want to. */ |
| 907 | if (strchr(str, '-') != NULL) { |
| 908 | DBG("utils_parse_time_suffix: invalid time string, should not contain '-'."); |
| 909 | ret = -1; |
| 910 | goto end; |
| 911 | } |
| 912 | |
| 913 | /* str_end will point to the \0 */ |
| 914 | str_end = str + strlen(str); |
| 915 | errno = 0; |
| 916 | base_time = strtoull(str, &num_end, 10); |
| 917 | if (errno != 0) { |
| 918 | PERROR("utils_parse_time_suffix strtoull on string \"%s\"", str); |
| 919 | ret = -1; |
| 920 | goto end; |
| 921 | } |
| 922 | |
| 923 | if (num_end == str) { |
| 924 | /* strtoull parsed nothing, not good. */ |
| 925 | DBG("utils_parse_time_suffix: strtoull had nothing good to parse."); |
| 926 | ret = -1; |
| 927 | goto end; |
| 928 | } |
| 929 | |
| 930 | /* Check if a prefix is present. */ |
| 931 | switch (*num_end) { |
| 932 | case 'u': |
| 933 | /* |
| 934 | * Microsecond (us) |
| 935 | * |
| 936 | * Skip the "us" if the string matches the "us" suffix, |
| 937 | * otherwise let the check for the end of the string handle |
| 938 | * the error reporting. |
| 939 | */ |
| 940 | if (*(num_end + 1) == 's') { |
| 941 | num_end += 2; |
| 942 | } |
| 943 | break; |
| 944 | case 'm': |
| 945 | if (*(num_end + 1) == 's') { |
| 946 | /* Millisecond (ms) */ |
| 947 | multiplier = USEC_PER_MSEC; |
| 948 | /* Skip the 's' */ |
| 949 | num_end++; |
| 950 | } else { |
| 951 | /* Minute (m) */ |
| 952 | multiplier = USEC_PER_MINUTE; |
| 953 | } |
| 954 | num_end++; |
| 955 | break; |
| 956 | case 's': |
| 957 | /* Second */ |
| 958 | multiplier = USEC_PER_SEC; |
| 959 | num_end++; |
| 960 | break; |
| 961 | case 'h': |
| 962 | /* Hour */ |
| 963 | multiplier = USEC_PER_HOURS; |
| 964 | num_end++; |
| 965 | break; |
| 966 | case '\0': |
| 967 | break; |
| 968 | default: |
| 969 | DBG("utils_parse_time_suffix: invalid suffix."); |
| 970 | ret = -1; |
| 971 | goto end; |
| 972 | } |
| 973 | |
| 974 | /* Check for garbage after the valid input. */ |
| 975 | if (num_end != str_end) { |
| 976 | DBG("utils_parse_time_suffix: Garbage after time string."); |
| 977 | ret = -1; |
| 978 | goto end; |
| 979 | } |
| 980 | |
| 981 | *time_us = base_time * multiplier; |
| 982 | |
| 983 | /* Check for overflow */ |
| 984 | if ((*time_us / multiplier) != base_time) { |
| 985 | DBG("utils_parse_time_suffix: oops, overflow detected."); |
| 986 | ret = -1; |
| 987 | goto end; |
| 988 | } |
| 989 | |
| 990 | ret = 0; |
| 991 | end: |
| 992 | return ret; |
| 993 | } |
| 994 | |
| 995 | /* |
| 996 | * fls: returns the position of the most significant bit. |
| 997 | * Returns 0 if no bit is set, else returns the position of the most |
| 998 | * significant bit (from 1 to 32 on 32-bit, from 1 to 64 on 64-bit). |
| 999 | */ |
| 1000 | #if defined(__i386) || defined(__x86_64) |
| 1001 | static inline unsigned int fls_u32(uint32_t x) |
| 1002 | { |
| 1003 | int r; |
| 1004 | |
| 1005 | asm("bsrl %1,%0\n\t" |
| 1006 | "jnz 1f\n\t" |
| 1007 | "movl $-1,%0\n\t" |
| 1008 | "1:\n\t" |
| 1009 | : "=r" (r) : "rm" (x)); |
| 1010 | return r + 1; |
| 1011 | } |
| 1012 | #define HAS_FLS_U32 |
| 1013 | #endif |
| 1014 | |
| 1015 | #if defined(__x86_64) && defined(__LP64__) |
| 1016 | static inline |
| 1017 | unsigned int fls_u64(uint64_t x) |
| 1018 | { |
| 1019 | long r; |
| 1020 | |
| 1021 | asm("bsrq %1,%0\n\t" |
| 1022 | "jnz 1f\n\t" |
| 1023 | "movq $-1,%0\n\t" |
| 1024 | "1:\n\t" |
| 1025 | : "=r" (r) : "rm" (x)); |
| 1026 | return r + 1; |
| 1027 | } |
| 1028 | #define HAS_FLS_U64 |
| 1029 | #endif |
| 1030 | |
| 1031 | #ifndef HAS_FLS_U64 |
| 1032 | static __attribute__((unused)) |
| 1033 | unsigned int fls_u64(uint64_t x) |
| 1034 | { |
| 1035 | unsigned int r = 64; |
| 1036 | |
| 1037 | if (!x) |
| 1038 | return 0; |
| 1039 | |
| 1040 | if (!(x & 0xFFFFFFFF00000000ULL)) { |
| 1041 | x <<= 32; |
| 1042 | r -= 32; |
| 1043 | } |
| 1044 | if (!(x & 0xFFFF000000000000ULL)) { |
| 1045 | x <<= 16; |
| 1046 | r -= 16; |
| 1047 | } |
| 1048 | if (!(x & 0xFF00000000000000ULL)) { |
| 1049 | x <<= 8; |
| 1050 | r -= 8; |
| 1051 | } |
| 1052 | if (!(x & 0xF000000000000000ULL)) { |
| 1053 | x <<= 4; |
| 1054 | r -= 4; |
| 1055 | } |
| 1056 | if (!(x & 0xC000000000000000ULL)) { |
| 1057 | x <<= 2; |
| 1058 | r -= 2; |
| 1059 | } |
| 1060 | if (!(x & 0x8000000000000000ULL)) { |
| 1061 | x <<= 1; |
| 1062 | r -= 1; |
| 1063 | } |
| 1064 | return r; |
| 1065 | } |
| 1066 | #endif |
| 1067 | |
| 1068 | #ifndef HAS_FLS_U32 |
| 1069 | static __attribute__((unused)) unsigned int fls_u32(uint32_t x) |
| 1070 | { |
| 1071 | unsigned int r = 32; |
| 1072 | |
| 1073 | if (!x) { |
| 1074 | return 0; |
| 1075 | } |
| 1076 | if (!(x & 0xFFFF0000U)) { |
| 1077 | x <<= 16; |
| 1078 | r -= 16; |
| 1079 | } |
| 1080 | if (!(x & 0xFF000000U)) { |
| 1081 | x <<= 8; |
| 1082 | r -= 8; |
| 1083 | } |
| 1084 | if (!(x & 0xF0000000U)) { |
| 1085 | x <<= 4; |
| 1086 | r -= 4; |
| 1087 | } |
| 1088 | if (!(x & 0xC0000000U)) { |
| 1089 | x <<= 2; |
| 1090 | r -= 2; |
| 1091 | } |
| 1092 | if (!(x & 0x80000000U)) { |
| 1093 | x <<= 1; |
| 1094 | r -= 1; |
| 1095 | } |
| 1096 | return r; |
| 1097 | } |
| 1098 | #endif |
| 1099 | |
| 1100 | /* |
| 1101 | * Return the minimum order for which x <= (1UL << order). |
| 1102 | * Return -1 if x is 0. |
| 1103 | */ |
| 1104 | LTTNG_HIDDEN |
| 1105 | int utils_get_count_order_u32(uint32_t x) |
| 1106 | { |
| 1107 | if (!x) { |
| 1108 | return -1; |
| 1109 | } |
| 1110 | |
| 1111 | return fls_u32(x - 1); |
| 1112 | } |
| 1113 | |
| 1114 | /* |
| 1115 | * Return the minimum order for which x <= (1UL << order). |
| 1116 | * Return -1 if x is 0. |
| 1117 | */ |
| 1118 | LTTNG_HIDDEN |
| 1119 | int utils_get_count_order_u64(uint64_t x) |
| 1120 | { |
| 1121 | if (!x) { |
| 1122 | return -1; |
| 1123 | } |
| 1124 | |
| 1125 | return fls_u64(x - 1); |
| 1126 | } |
| 1127 | |
| 1128 | /** |
| 1129 | * Obtain the value of LTTNG_HOME environment variable, if exists. |
| 1130 | * Otherwise returns the value of HOME. |
| 1131 | */ |
| 1132 | LTTNG_HIDDEN |
| 1133 | const char *utils_get_home_dir(void) |
| 1134 | { |
| 1135 | char *val = NULL; |
| 1136 | struct passwd *pwd; |
| 1137 | |
| 1138 | val = lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR); |
| 1139 | if (val != NULL) { |
| 1140 | goto end; |
| 1141 | } |
| 1142 | val = lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR); |
| 1143 | if (val != NULL) { |
| 1144 | goto end; |
| 1145 | } |
| 1146 | |
| 1147 | /* Fallback on the password file entry. */ |
| 1148 | pwd = getpwuid(getuid()); |
| 1149 | if (!pwd) { |
| 1150 | goto end; |
| 1151 | } |
| 1152 | val = pwd->pw_dir; |
| 1153 | |
| 1154 | DBG3("Home directory is '%s'", val); |
| 1155 | |
| 1156 | end: |
| 1157 | return val; |
| 1158 | } |
| 1159 | |
| 1160 | /** |
| 1161 | * Get user's home directory. Dynamically allocated, must be freed |
| 1162 | * by the caller. |
| 1163 | */ |
| 1164 | LTTNG_HIDDEN |
| 1165 | char *utils_get_user_home_dir(uid_t uid) |
| 1166 | { |
| 1167 | struct passwd pwd; |
| 1168 | struct passwd *result; |
| 1169 | char *home_dir = NULL; |
| 1170 | char *buf = NULL; |
| 1171 | long buflen; |
| 1172 | int ret; |
| 1173 | |
| 1174 | buflen = sysconf(_SC_GETPW_R_SIZE_MAX); |
| 1175 | if (buflen == -1) { |
| 1176 | goto end; |
| 1177 | } |
| 1178 | retry: |
| 1179 | buf = zmalloc(buflen); |
| 1180 | if (!buf) { |
| 1181 | goto end; |
| 1182 | } |
| 1183 | |
| 1184 | ret = getpwuid_r(uid, &pwd, buf, buflen, &result); |
| 1185 | if (ret || !result) { |
| 1186 | if (ret == ERANGE) { |
| 1187 | free(buf); |
| 1188 | buflen *= 2; |
| 1189 | goto retry; |
| 1190 | } |
| 1191 | goto end; |
| 1192 | } |
| 1193 | |
| 1194 | home_dir = strdup(pwd.pw_dir); |
| 1195 | end: |
| 1196 | free(buf); |
| 1197 | return home_dir; |
| 1198 | } |
| 1199 | |
| 1200 | /* |
| 1201 | * With the given format, fill dst with the time of len maximum siz. |
| 1202 | * |
| 1203 | * Return amount of bytes set in the buffer or else 0 on error. |
| 1204 | */ |
| 1205 | LTTNG_HIDDEN |
| 1206 | size_t utils_get_current_time_str(const char *format, char *dst, size_t len) |
| 1207 | { |
| 1208 | size_t ret; |
| 1209 | time_t rawtime; |
| 1210 | struct tm *timeinfo; |
| 1211 | |
| 1212 | assert(format); |
| 1213 | assert(dst); |
| 1214 | |
| 1215 | /* Get date and time for session path */ |
| 1216 | time(&rawtime); |
| 1217 | timeinfo = localtime(&rawtime); |
| 1218 | ret = strftime(dst, len, format, timeinfo); |
| 1219 | if (ret == 0) { |
| 1220 | ERR("Unable to strftime with format %s at dst %p of len %zu", format, |
| 1221 | dst, len); |
| 1222 | } |
| 1223 | |
| 1224 | return ret; |
| 1225 | } |
| 1226 | |
| 1227 | /* |
| 1228 | * Return 0 on success and set *gid to the group_ID matching the passed name. |
| 1229 | * Else -1 if it cannot be found or an error occurred. |
| 1230 | */ |
| 1231 | LTTNG_HIDDEN |
| 1232 | int utils_get_group_id(const char *name, bool warn, gid_t *gid) |
| 1233 | { |
| 1234 | static volatile int warn_once; |
| 1235 | int ret; |
| 1236 | long sys_len; |
| 1237 | size_t len; |
| 1238 | struct group grp; |
| 1239 | struct group *result; |
| 1240 | struct lttng_dynamic_buffer buffer; |
| 1241 | |
| 1242 | /* Get the system limit, if it exists. */ |
| 1243 | sys_len = sysconf(_SC_GETGR_R_SIZE_MAX); |
| 1244 | if (sys_len == -1) { |
| 1245 | len = 1024; |
| 1246 | } else { |
| 1247 | len = (size_t) sys_len; |
| 1248 | } |
| 1249 | |
| 1250 | lttng_dynamic_buffer_init(&buffer); |
| 1251 | ret = lttng_dynamic_buffer_set_size(&buffer, len); |
| 1252 | if (ret) { |
| 1253 | ERR("Failed to allocate group info buffer"); |
| 1254 | ret = -1; |
| 1255 | goto error; |
| 1256 | } |
| 1257 | |
| 1258 | while ((ret = getgrnam_r(name, &grp, buffer.data, buffer.size, &result)) == ERANGE) { |
| 1259 | const size_t new_len = 2 * buffer.size; |
| 1260 | |
| 1261 | /* Buffer is not big enough, increase its size. */ |
| 1262 | if (new_len < buffer.size) { |
| 1263 | ERR("Group info buffer size overflow"); |
| 1264 | ret = -1; |
| 1265 | goto error; |
| 1266 | } |
| 1267 | |
| 1268 | ret = lttng_dynamic_buffer_set_size(&buffer, new_len); |
| 1269 | if (ret) { |
| 1270 | ERR("Failed to grow group info buffer to %zu bytes", |
| 1271 | new_len); |
| 1272 | ret = -1; |
| 1273 | goto error; |
| 1274 | } |
| 1275 | } |
| 1276 | if (ret) { |
| 1277 | PERROR("Failed to get group file entry for group name \"%s\"", |
| 1278 | name); |
| 1279 | ret = -1; |
| 1280 | goto error; |
| 1281 | } |
| 1282 | |
| 1283 | /* Group not found. */ |
| 1284 | if (!result) { |
| 1285 | ret = -1; |
| 1286 | goto error; |
| 1287 | } |
| 1288 | |
| 1289 | *gid = result->gr_gid; |
| 1290 | ret = 0; |
| 1291 | |
| 1292 | error: |
| 1293 | if (ret && warn && !warn_once) { |
| 1294 | WARN("No tracing group detected"); |
| 1295 | warn_once = 1; |
| 1296 | } |
| 1297 | lttng_dynamic_buffer_reset(&buffer); |
| 1298 | return ret; |
| 1299 | } |
| 1300 | |
| 1301 | /* |
| 1302 | * Return a newly allocated option string. This string is to be used as the |
| 1303 | * optstring argument of getopt_long(), see GETOPT(3). opt_count is the number |
| 1304 | * of elements in the long_options array. Returns NULL if the string's |
| 1305 | * allocation fails. |
| 1306 | */ |
| 1307 | LTTNG_HIDDEN |
| 1308 | char *utils_generate_optstring(const struct option *long_options, |
| 1309 | size_t opt_count) |
| 1310 | { |
| 1311 | int i; |
| 1312 | size_t string_len = opt_count, str_pos = 0; |
| 1313 | char *optstring; |
| 1314 | |
| 1315 | /* |
| 1316 | * Compute the necessary string length. One letter per option, two when an |
| 1317 | * argument is necessary, and a trailing NULL. |
| 1318 | */ |
| 1319 | for (i = 0; i < opt_count; i++) { |
| 1320 | string_len += long_options[i].has_arg ? 1 : 0; |
| 1321 | } |
| 1322 | |
| 1323 | optstring = zmalloc(string_len); |
| 1324 | if (!optstring) { |
| 1325 | goto end; |
| 1326 | } |
| 1327 | |
| 1328 | for (i = 0; i < opt_count; i++) { |
| 1329 | if (!long_options[i].name) { |
| 1330 | /* Got to the trailing NULL element */ |
| 1331 | break; |
| 1332 | } |
| 1333 | |
| 1334 | if (long_options[i].val != '\0') { |
| 1335 | optstring[str_pos++] = (char) long_options[i].val; |
| 1336 | if (long_options[i].has_arg) { |
| 1337 | optstring[str_pos++] = ':'; |
| 1338 | } |
| 1339 | } |
| 1340 | } |
| 1341 | |
| 1342 | end: |
| 1343 | return optstring; |
| 1344 | } |
| 1345 | |
| 1346 | /* |
| 1347 | * Try to remove a hierarchy of empty directories, recursively. Don't unlink |
| 1348 | * any file. Try to rmdir any empty directory within the hierarchy. |
| 1349 | */ |
| 1350 | LTTNG_HIDDEN |
| 1351 | int utils_recursive_rmdir(const char *path) |
| 1352 | { |
| 1353 | int ret; |
| 1354 | struct lttng_directory_handle *handle; |
| 1355 | |
| 1356 | handle = lttng_directory_handle_create(NULL); |
| 1357 | if (!handle) { |
| 1358 | ret = -1; |
| 1359 | goto end; |
| 1360 | } |
| 1361 | ret = lttng_directory_handle_remove_subdirectory(handle, path); |
| 1362 | end: |
| 1363 | lttng_directory_handle_put(handle); |
| 1364 | return ret; |
| 1365 | } |
| 1366 | |
| 1367 | LTTNG_HIDDEN |
| 1368 | int utils_truncate_stream_file(int fd, off_t length) |
| 1369 | { |
| 1370 | int ret; |
| 1371 | off_t lseek_ret; |
| 1372 | |
| 1373 | ret = ftruncate(fd, length); |
| 1374 | if (ret < 0) { |
| 1375 | PERROR("ftruncate"); |
| 1376 | goto end; |
| 1377 | } |
| 1378 | lseek_ret = lseek(fd, length, SEEK_SET); |
| 1379 | if (lseek_ret < 0) { |
| 1380 | PERROR("lseek"); |
| 1381 | ret = -1; |
| 1382 | goto end; |
| 1383 | } |
| 1384 | end: |
| 1385 | return ret; |
| 1386 | } |
| 1387 | |
| 1388 | static const char *get_man_bin_path(void) |
| 1389 | { |
| 1390 | char *env_man_path = lttng_secure_getenv(DEFAULT_MAN_BIN_PATH_ENV); |
| 1391 | |
| 1392 | if (env_man_path) { |
| 1393 | return env_man_path; |
| 1394 | } |
| 1395 | |
| 1396 | return DEFAULT_MAN_BIN_PATH; |
| 1397 | } |
| 1398 | |
| 1399 | LTTNG_HIDDEN |
| 1400 | int utils_show_help(int section, const char *page_name, |
| 1401 | const char *help_msg) |
| 1402 | { |
| 1403 | char section_string[8]; |
| 1404 | const char *man_bin_path = get_man_bin_path(); |
| 1405 | int ret = 0; |
| 1406 | |
| 1407 | if (help_msg) { |
| 1408 | printf("%s", help_msg); |
| 1409 | goto end; |
| 1410 | } |
| 1411 | |
| 1412 | /* Section integer -> section string */ |
| 1413 | ret = sprintf(section_string, "%d", section); |
| 1414 | assert(ret > 0 && ret < 8); |
| 1415 | |
| 1416 | /* |
| 1417 | * Execute man pager. |
| 1418 | * |
| 1419 | * We provide -M to man here because LTTng-tools can |
| 1420 | * be installed outside /usr, in which case its man pages are |
| 1421 | * not located in the default /usr/share/man directory. |
| 1422 | */ |
| 1423 | ret = execlp(man_bin_path, "man", "-M", MANPATH, |
| 1424 | section_string, page_name, NULL); |
| 1425 | |
| 1426 | end: |
| 1427 | return ret; |
| 1428 | } |
| 1429 | |
| 1430 | static |
| 1431 | int read_proc_meminfo_field(const char *field, size_t *value) |
| 1432 | { |
| 1433 | int ret; |
| 1434 | FILE *proc_meminfo; |
| 1435 | char name[PROC_MEMINFO_FIELD_MAX_NAME_LEN] = {}; |
| 1436 | |
| 1437 | proc_meminfo = fopen(PROC_MEMINFO_PATH, "r"); |
| 1438 | if (!proc_meminfo) { |
| 1439 | PERROR("Failed to fopen() " PROC_MEMINFO_PATH); |
| 1440 | ret = -1; |
| 1441 | goto fopen_error; |
| 1442 | } |
| 1443 | |
| 1444 | /* |
| 1445 | * Read the contents of /proc/meminfo line by line to find the right |
| 1446 | * field. |
| 1447 | */ |
| 1448 | while (!feof(proc_meminfo)) { |
| 1449 | unsigned long value_kb; |
| 1450 | |
| 1451 | ret = fscanf(proc_meminfo, |
| 1452 | "%" MAX_NAME_LEN_SCANF_IS_A_BROKEN_API "s %lu kB\n", |
| 1453 | name, &value_kb); |
| 1454 | if (ret == EOF) { |
| 1455 | /* |
| 1456 | * fscanf() returning EOF can indicate EOF or an error. |
| 1457 | */ |
| 1458 | if (ferror(proc_meminfo)) { |
| 1459 | PERROR("Failed to parse " PROC_MEMINFO_PATH); |
| 1460 | } |
| 1461 | break; |
| 1462 | } |
| 1463 | |
| 1464 | if (ret == 2 && strcmp(name, field) == 0) { |
| 1465 | /* |
| 1466 | * This number is displayed in kilo-bytes. Return the |
| 1467 | * number of bytes. |
| 1468 | */ |
| 1469 | *value = ((size_t) value_kb) * 1024; |
| 1470 | ret = 0; |
| 1471 | goto found; |
| 1472 | } |
| 1473 | } |
| 1474 | /* Reached the end of the file without finding the right field. */ |
| 1475 | ret = -1; |
| 1476 | |
| 1477 | found: |
| 1478 | fclose(proc_meminfo); |
| 1479 | fopen_error: |
| 1480 | return ret; |
| 1481 | } |
| 1482 | |
| 1483 | /* |
| 1484 | * Returns an estimate of the number of bytes of memory available based on the |
| 1485 | * the information in `/proc/meminfo`. The number returned by this function is |
| 1486 | * a best guess. |
| 1487 | */ |
| 1488 | LTTNG_HIDDEN |
| 1489 | int utils_get_memory_available(size_t *value) |
| 1490 | { |
| 1491 | return read_proc_meminfo_field(PROC_MEMINFO_MEMAVAILABLE_LINE, value); |
| 1492 | } |
| 1493 | |
| 1494 | /* |
| 1495 | * Returns the total size of the memory on the system in bytes based on the |
| 1496 | * the information in `/proc/meminfo`. |
| 1497 | */ |
| 1498 | LTTNG_HIDDEN |
| 1499 | int utils_get_memory_total(size_t *value) |
| 1500 | { |
| 1501 | return read_proc_meminfo_field(PROC_MEMINFO_MEMTOTAL_LINE, value); |
| 1502 | } |
| 1503 | |
| 1504 | LTTNG_HIDDEN |
| 1505 | int utils_change_working_directory(const char *path) |
| 1506 | { |
| 1507 | int ret; |
| 1508 | |
| 1509 | assert(path); |
| 1510 | |
| 1511 | DBG("Changing working directory to \"%s\"", path); |
| 1512 | ret = chdir(path); |
| 1513 | if (ret) { |
| 1514 | PERROR("Failed to change working directory to \"%s\"", path); |
| 1515 | goto end; |
| 1516 | } |
| 1517 | |
| 1518 | /* Check for write access */ |
| 1519 | if (access(path, W_OK)) { |
| 1520 | if (errno == EACCES) { |
| 1521 | /* |
| 1522 | * Do not treat this as an error since the permission |
| 1523 | * might change in the lifetime of the process |
| 1524 | */ |
| 1525 | DBG("Working directory \"%s\" is not writable", path); |
| 1526 | } else { |
| 1527 | PERROR("Failed to check if working directory \"%s\" is writable", |
| 1528 | path); |
| 1529 | } |
| 1530 | } |
| 1531 | |
| 1532 | end: |
| 1533 | return ret; |
| 1534 | } |
| 1535 | |
| 1536 | LTTNG_HIDDEN |
| 1537 | enum lttng_error_code utils_user_id_from_name(const char *user_name, uid_t *uid) |
| 1538 | { |
| 1539 | struct passwd p, *pres; |
| 1540 | int ret; |
| 1541 | enum lttng_error_code ret_val = LTTNG_OK; |
| 1542 | char *buf = NULL; |
| 1543 | ssize_t buflen; |
| 1544 | |
| 1545 | buflen = sysconf(_SC_GETPW_R_SIZE_MAX); |
| 1546 | if (buflen < 0) { |
| 1547 | buflen = FALLBACK_USER_BUFLEN; |
| 1548 | } |
| 1549 | |
| 1550 | buf = zmalloc(buflen); |
| 1551 | if (!buf) { |
| 1552 | ret_val = LTTNG_ERR_NOMEM; |
| 1553 | goto end; |
| 1554 | } |
| 1555 | |
| 1556 | for (;;) { |
| 1557 | ret = getpwnam_r(user_name, &p, buf, buflen, &pres); |
| 1558 | switch (ret) { |
| 1559 | case EINTR: |
| 1560 | continue; |
| 1561 | case ERANGE: |
| 1562 | buflen *= 2; |
| 1563 | free(buf); |
| 1564 | buf = zmalloc(buflen); |
| 1565 | if (!buf) { |
| 1566 | ret_val = LTTNG_ERR_NOMEM; |
| 1567 | goto end; |
| 1568 | } |
| 1569 | continue; |
| 1570 | default: |
| 1571 | goto end_loop; |
| 1572 | } |
| 1573 | } |
| 1574 | end_loop: |
| 1575 | |
| 1576 | switch (ret) { |
| 1577 | case 0: |
| 1578 | if (pres == NULL) { |
| 1579 | ret_val = LTTNG_ERR_USER_NOT_FOUND; |
| 1580 | } else { |
| 1581 | *uid = p.pw_uid; |
| 1582 | DBG("Lookup of tracker UID/VUID: name '%s' maps to uid %" PRId64, |
| 1583 | user_name, (int64_t) *uid); |
| 1584 | ret_val = LTTNG_OK; |
| 1585 | } |
| 1586 | break; |
| 1587 | case ENOENT: |
| 1588 | case ESRCH: |
| 1589 | case EBADF: |
| 1590 | case EPERM: |
| 1591 | ret_val = LTTNG_ERR_USER_NOT_FOUND; |
| 1592 | break; |
| 1593 | default: |
| 1594 | ret_val = LTTNG_ERR_NOMEM; |
| 1595 | } |
| 1596 | end: |
| 1597 | free(buf); |
| 1598 | return ret_val; |
| 1599 | } |
| 1600 | |
| 1601 | LTTNG_HIDDEN |
| 1602 | enum lttng_error_code utils_group_id_from_name( |
| 1603 | const char *group_name, gid_t *gid) |
| 1604 | { |
| 1605 | struct group g, *gres; |
| 1606 | int ret; |
| 1607 | enum lttng_error_code ret_val = LTTNG_OK; |
| 1608 | char *buf = NULL; |
| 1609 | ssize_t buflen; |
| 1610 | |
| 1611 | buflen = sysconf(_SC_GETGR_R_SIZE_MAX); |
| 1612 | if (buflen < 0) { |
| 1613 | buflen = FALLBACK_GROUP_BUFLEN; |
| 1614 | } |
| 1615 | |
| 1616 | buf = zmalloc(buflen); |
| 1617 | if (!buf) { |
| 1618 | ret_val = LTTNG_ERR_NOMEM; |
| 1619 | goto end; |
| 1620 | } |
| 1621 | |
| 1622 | for (;;) { |
| 1623 | ret = getgrnam_r(group_name, &g, buf, buflen, &gres); |
| 1624 | switch (ret) { |
| 1625 | case EINTR: |
| 1626 | continue; |
| 1627 | case ERANGE: |
| 1628 | buflen *= 2; |
| 1629 | free(buf); |
| 1630 | buf = zmalloc(buflen); |
| 1631 | if (!buf) { |
| 1632 | ret_val = LTTNG_ERR_NOMEM; |
| 1633 | goto end; |
| 1634 | } |
| 1635 | continue; |
| 1636 | default: |
| 1637 | goto end_loop; |
| 1638 | } |
| 1639 | } |
| 1640 | end_loop: |
| 1641 | |
| 1642 | switch (ret) { |
| 1643 | case 0: |
| 1644 | if (gres == NULL) { |
| 1645 | ret_val = LTTNG_ERR_GROUP_NOT_FOUND; |
| 1646 | } else { |
| 1647 | *gid = g.gr_gid; |
| 1648 | DBG("Lookup of tracker GID/GUID: name '%s' maps to gid %" PRId64, |
| 1649 | group_name, (int64_t) *gid); |
| 1650 | ret_val = LTTNG_OK; |
| 1651 | } |
| 1652 | break; |
| 1653 | case ENOENT: |
| 1654 | case ESRCH: |
| 1655 | case EBADF: |
| 1656 | case EPERM: |
| 1657 | ret_val = LTTNG_ERR_GROUP_NOT_FOUND; |
| 1658 | break; |
| 1659 | default: |
| 1660 | ret_val = LTTNG_ERR_NOMEM; |
| 1661 | } |
| 1662 | end: |
| 1663 | free(buf); |
| 1664 | return ret_val; |
| 1665 | } |