| 1 | /* |
| 2 | * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License, version 2 only, as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 11 | * more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along with |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 15 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #define _GNU_SOURCE |
| 19 | #include <assert.h> |
| 20 | #include <ctype.h> |
| 21 | #include <fcntl.h> |
| 22 | #include <limits.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <sys/types.h> |
| 26 | #include <sys/stat.h> |
| 27 | #include <unistd.h> |
| 28 | #include <inttypes.h> |
| 29 | |
| 30 | #include <common/common.h> |
| 31 | #include <common/runas.h> |
| 32 | |
| 33 | #include "utils.h" |
| 34 | |
| 35 | /* |
| 36 | * Return the realpath(3) of the path even if the last directory token does not |
| 37 | * exist. For example, with /tmp/test1/test2, if test2/ does not exist but the |
| 38 | * /tmp/test1 does, the real path is returned. In normal time, realpath(3) |
| 39 | * fails if the end point directory does not exist. |
| 40 | */ |
| 41 | LTTNG_HIDDEN |
| 42 | char *utils_expand_path(const char *path) |
| 43 | { |
| 44 | const char *end_path = path; |
| 45 | char *next, *cut_path = NULL, *expanded_path = NULL; |
| 46 | |
| 47 | /* Safety net */ |
| 48 | if (path == NULL) { |
| 49 | goto error; |
| 50 | } |
| 51 | |
| 52 | /* Find last token delimited by '/' */ |
| 53 | while ((next = strpbrk(end_path + 1, "/"))) { |
| 54 | end_path = next; |
| 55 | } |
| 56 | |
| 57 | /* Cut last token from original path */ |
| 58 | cut_path = strndup(path, end_path - path); |
| 59 | |
| 60 | expanded_path = zmalloc(PATH_MAX); |
| 61 | if (expanded_path == NULL) { |
| 62 | PERROR("zmalloc expand path"); |
| 63 | goto error; |
| 64 | } |
| 65 | |
| 66 | expanded_path = realpath((char *)cut_path, expanded_path); |
| 67 | if (expanded_path == NULL) { |
| 68 | switch (errno) { |
| 69 | case ENOENT: |
| 70 | ERR("%s: No such file or directory", cut_path); |
| 71 | break; |
| 72 | default: |
| 73 | PERROR("realpath utils expand path"); |
| 74 | break; |
| 75 | } |
| 76 | goto error; |
| 77 | } |
| 78 | |
| 79 | /* Add end part to expanded path */ |
| 80 | strncat(expanded_path, end_path, PATH_MAX - strlen(expanded_path) - 1); |
| 81 | |
| 82 | free(cut_path); |
| 83 | return expanded_path; |
| 84 | |
| 85 | error: |
| 86 | free(expanded_path); |
| 87 | free(cut_path); |
| 88 | return NULL; |
| 89 | } |
| 90 | |
| 91 | /* |
| 92 | * Create a pipe in dst. |
| 93 | */ |
| 94 | LTTNG_HIDDEN |
| 95 | int utils_create_pipe(int *dst) |
| 96 | { |
| 97 | int ret; |
| 98 | |
| 99 | if (dst == NULL) { |
| 100 | return -1; |
| 101 | } |
| 102 | |
| 103 | ret = pipe(dst); |
| 104 | if (ret < 0) { |
| 105 | PERROR("create pipe"); |
| 106 | } |
| 107 | |
| 108 | return ret; |
| 109 | } |
| 110 | |
| 111 | /* |
| 112 | * Create pipe and set CLOEXEC flag to both fd. |
| 113 | * |
| 114 | * Make sure the pipe opened by this function are closed at some point. Use |
| 115 | * utils_close_pipe(). |
| 116 | */ |
| 117 | LTTNG_HIDDEN |
| 118 | int utils_create_pipe_cloexec(int *dst) |
| 119 | { |
| 120 | int ret, i; |
| 121 | |
| 122 | if (dst == NULL) { |
| 123 | return -1; |
| 124 | } |
| 125 | |
| 126 | ret = utils_create_pipe(dst); |
| 127 | if (ret < 0) { |
| 128 | goto error; |
| 129 | } |
| 130 | |
| 131 | for (i = 0; i < 2; i++) { |
| 132 | ret = fcntl(dst[i], F_SETFD, FD_CLOEXEC); |
| 133 | if (ret < 0) { |
| 134 | PERROR("fcntl pipe cloexec"); |
| 135 | goto error; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | error: |
| 140 | return ret; |
| 141 | } |
| 142 | |
| 143 | /* |
| 144 | * Close both read and write side of the pipe. |
| 145 | */ |
| 146 | LTTNG_HIDDEN |
| 147 | void utils_close_pipe(int *src) |
| 148 | { |
| 149 | int i, ret; |
| 150 | |
| 151 | if (src == NULL) { |
| 152 | return; |
| 153 | } |
| 154 | |
| 155 | for (i = 0; i < 2; i++) { |
| 156 | /* Safety check */ |
| 157 | if (src[i] < 0) { |
| 158 | continue; |
| 159 | } |
| 160 | |
| 161 | ret = close(src[i]); |
| 162 | if (ret) { |
| 163 | PERROR("close pipe"); |
| 164 | } |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | * Create a new string using two strings range. |
| 170 | */ |
| 171 | LTTNG_HIDDEN |
| 172 | char *utils_strdupdelim(const char *begin, const char *end) |
| 173 | { |
| 174 | char *str; |
| 175 | |
| 176 | str = zmalloc(end - begin + 1); |
| 177 | if (str == NULL) { |
| 178 | PERROR("zmalloc strdupdelim"); |
| 179 | goto error; |
| 180 | } |
| 181 | |
| 182 | memcpy(str, begin, end - begin); |
| 183 | str[end - begin] = '\0'; |
| 184 | |
| 185 | error: |
| 186 | return str; |
| 187 | } |
| 188 | |
| 189 | /* |
| 190 | * Set CLOEXEC flag to the give file descriptor. |
| 191 | */ |
| 192 | LTTNG_HIDDEN |
| 193 | int utils_set_fd_cloexec(int fd) |
| 194 | { |
| 195 | int ret; |
| 196 | |
| 197 | if (fd < 0) { |
| 198 | ret = -EINVAL; |
| 199 | goto end; |
| 200 | } |
| 201 | |
| 202 | ret = fcntl(fd, F_SETFD, FD_CLOEXEC); |
| 203 | if (ret < 0) { |
| 204 | PERROR("fcntl cloexec"); |
| 205 | ret = -errno; |
| 206 | } |
| 207 | |
| 208 | end: |
| 209 | return ret; |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * Create pid file to the given path and filename. |
| 214 | */ |
| 215 | LTTNG_HIDDEN |
| 216 | int utils_create_pid_file(pid_t pid, const char *filepath) |
| 217 | { |
| 218 | int ret; |
| 219 | FILE *fp; |
| 220 | |
| 221 | assert(filepath); |
| 222 | |
| 223 | fp = fopen(filepath, "w"); |
| 224 | if (fp == NULL) { |
| 225 | PERROR("open pid file %s", filepath); |
| 226 | ret = -1; |
| 227 | goto error; |
| 228 | } |
| 229 | |
| 230 | ret = fprintf(fp, "%d\n", pid); |
| 231 | if (ret < 0) { |
| 232 | PERROR("fprintf pid file"); |
| 233 | } |
| 234 | |
| 235 | fclose(fp); |
| 236 | DBG("Pid %d written in file %s", pid, filepath); |
| 237 | error: |
| 238 | return ret; |
| 239 | } |
| 240 | |
| 241 | /* |
| 242 | * Recursively create directory using the given path and mode. |
| 243 | * |
| 244 | * On success, return 0 else a negative error code. |
| 245 | */ |
| 246 | LTTNG_HIDDEN |
| 247 | int utils_mkdir_recursive(const char *path, mode_t mode) |
| 248 | { |
| 249 | char *p, tmp[PATH_MAX]; |
| 250 | struct stat statbuf; |
| 251 | size_t len; |
| 252 | int ret; |
| 253 | |
| 254 | assert(path); |
| 255 | |
| 256 | ret = snprintf(tmp, sizeof(tmp), "%s", path); |
| 257 | if (ret < 0) { |
| 258 | PERROR("snprintf mkdir"); |
| 259 | goto error; |
| 260 | } |
| 261 | |
| 262 | len = ret; |
| 263 | if (tmp[len - 1] == '/') { |
| 264 | tmp[len - 1] = 0; |
| 265 | } |
| 266 | |
| 267 | for (p = tmp + 1; *p; p++) { |
| 268 | if (*p == '/') { |
| 269 | *p = 0; |
| 270 | if (tmp[strlen(tmp) - 1] == '.' && |
| 271 | tmp[strlen(tmp) - 2] == '.' && |
| 272 | tmp[strlen(tmp) - 3] == '/') { |
| 273 | ERR("Using '/../' is not permitted in the trace path (%s)", |
| 274 | tmp); |
| 275 | ret = -1; |
| 276 | goto error; |
| 277 | } |
| 278 | ret = stat(tmp, &statbuf); |
| 279 | if (ret < 0) { |
| 280 | ret = mkdir(tmp, mode); |
| 281 | if (ret < 0) { |
| 282 | if (errno != EEXIST) { |
| 283 | PERROR("mkdir recursive"); |
| 284 | ret = -errno; |
| 285 | goto error; |
| 286 | } |
| 287 | } |
| 288 | } |
| 289 | *p = '/'; |
| 290 | } |
| 291 | } |
| 292 | |
| 293 | ret = mkdir(tmp, mode); |
| 294 | if (ret < 0) { |
| 295 | if (errno != EEXIST) { |
| 296 | PERROR("mkdir recursive last piece"); |
| 297 | ret = -errno; |
| 298 | } else { |
| 299 | ret = 0; |
| 300 | } |
| 301 | } |
| 302 | |
| 303 | error: |
| 304 | return ret; |
| 305 | } |
| 306 | |
| 307 | /* |
| 308 | * Create the stream tracefile on disk. |
| 309 | * |
| 310 | * Return 0 on success or else a negative value. |
| 311 | */ |
| 312 | int utils_create_stream_file(char *path_name, char *file_name, uint64_t size, |
| 313 | uint64_t count, int uid, int gid) |
| 314 | { |
| 315 | int ret, out_fd; |
| 316 | char full_path[PATH_MAX], *path_name_id = NULL, *path; |
| 317 | |
| 318 | assert(path_name); |
| 319 | assert(file_name); |
| 320 | |
| 321 | ret = snprintf(full_path, sizeof(full_path), "%s/%s", |
| 322 | path_name, file_name); |
| 323 | if (ret < 0) { |
| 324 | PERROR("snprintf create output file"); |
| 325 | goto error; |
| 326 | } |
| 327 | |
| 328 | /* |
| 329 | * If we split the trace in multiple files, we have to add the count at the |
| 330 | * end of the tracefile name |
| 331 | */ |
| 332 | if (size > 0) { |
| 333 | ret = asprintf(&path_name_id, "%s_%" PRIu64, full_path, count); |
| 334 | if (ret < 0) { |
| 335 | PERROR("Allocating path name ID"); |
| 336 | goto error; |
| 337 | } |
| 338 | path = path_name_id; |
| 339 | } else { |
| 340 | path = full_path; |
| 341 | } |
| 342 | |
| 343 | /* Open with 660 mode */ |
| 344 | out_fd = run_as_open(path, O_WRONLY | O_CREAT | O_TRUNC, |
| 345 | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP, uid, gid); |
| 346 | if (out_fd < 0) { |
| 347 | PERROR("open stream path %s", path); |
| 348 | goto error_open; |
| 349 | } |
| 350 | ret = out_fd; |
| 351 | |
| 352 | error_open: |
| 353 | free(path_name_id); |
| 354 | error: |
| 355 | return ret; |
| 356 | } |
| 357 | |
| 358 | /* |
| 359 | * Change the output tracefile according to the given size and count The |
| 360 | * new_count pointer is set during this operation. |
| 361 | * |
| 362 | * From the consumer, the stream lock MUST be held before calling this function |
| 363 | * because we are modifying the stream status. |
| 364 | * |
| 365 | * Return 0 on success or else a negative value. |
| 366 | */ |
| 367 | int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size, |
| 368 | uint64_t count, int uid, int gid, int out_fd, uint64_t *new_count) |
| 369 | { |
| 370 | int ret; |
| 371 | |
| 372 | ret = close(out_fd); |
| 373 | if (ret < 0) { |
| 374 | PERROR("Closing tracefile"); |
| 375 | goto error; |
| 376 | } |
| 377 | |
| 378 | if (count > 0) { |
| 379 | *new_count = (*new_count + 1) % count; |
| 380 | } else { |
| 381 | (*new_count)++; |
| 382 | } |
| 383 | |
| 384 | return utils_create_stream_file(path_name, file_name, size, *new_count, |
| 385 | uid, gid); |
| 386 | error: |
| 387 | return ret; |
| 388 | } |