| 1 | /* |
| 2 | * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com> |
| 3 | * David Goulet <dgoulet@efficios.com> |
| 4 | * 2016 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License, version 2 only, as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 13 | * more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License along with |
| 16 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 17 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 18 | */ |
| 19 | |
| 20 | #define _LGPL_SOURCE |
| 21 | #include <assert.h> |
| 22 | #include <sys/stat.h> |
| 23 | #include <sys/types.h> |
| 24 | #include <fcntl.h> |
| 25 | |
| 26 | #include <common/common.h> |
| 27 | #include <common/defaults.h> |
| 28 | #include <common/compat/endian.h> |
| 29 | #include <common/utils.h> |
| 30 | |
| 31 | #include "index.h" |
| 32 | |
| 33 | /* |
| 34 | * Create the index file associated with a trace file. |
| 35 | * |
| 36 | * Return allocated struct lttng_index_file, NULL on error. |
| 37 | */ |
| 38 | struct lttng_index_file *lttng_index_file_create(char *path_name, |
| 39 | char *stream_name, int uid, int gid, |
| 40 | uint64_t size, uint64_t count, uint32_t major, uint32_t minor) |
| 41 | { |
| 42 | struct lttng_index_file *index_file; |
| 43 | int ret, fd = -1; |
| 44 | ssize_t size_ret; |
| 45 | struct ctf_packet_index_file_hdr hdr; |
| 46 | char fullpath[PATH_MAX]; |
| 47 | uint32_t element_len = ctf_packet_index_len(major, minor); |
| 48 | |
| 49 | index_file = zmalloc(sizeof(*index_file)); |
| 50 | if (!index_file) { |
| 51 | PERROR("allocating lttng_index_file"); |
| 52 | goto error; |
| 53 | } |
| 54 | |
| 55 | ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR, |
| 56 | path_name); |
| 57 | if (ret < 0) { |
| 58 | PERROR("snprintf index path"); |
| 59 | goto error; |
| 60 | } |
| 61 | |
| 62 | /* Create index directory if necessary. */ |
| 63 | ret = utils_mkdir(fullpath, S_IRWXU | S_IRWXG, uid, gid); |
| 64 | if (ret < 0) { |
| 65 | if (errno != EEXIST) { |
| 66 | PERROR("Index trace directory creation error"); |
| 67 | goto error; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | /* |
| 72 | * For tracefile rotation. We need to unlink the old |
| 73 | * file if present to synchronize with the tail of the |
| 74 | * live viewer which could be working on this same file. |
| 75 | * By doing so, any reference to the old index file |
| 76 | * stays valid even if we re-create a new file with the |
| 77 | * same name afterwards. |
| 78 | */ |
| 79 | ret = utils_unlink_stream_file(fullpath, stream_name, size, count, uid, |
| 80 | gid, DEFAULT_INDEX_FILE_SUFFIX); |
| 81 | if (ret < 0 && errno != ENOENT) { |
| 82 | goto error; |
| 83 | } |
| 84 | ret = utils_create_stream_file(fullpath, stream_name, size, count, uid, |
| 85 | gid, DEFAULT_INDEX_FILE_SUFFIX); |
| 86 | if (ret < 0) { |
| 87 | goto error; |
| 88 | } |
| 89 | fd = ret; |
| 90 | |
| 91 | hdr.magic = htobe32(CTF_INDEX_MAGIC); |
| 92 | hdr.index_major = htobe32(major); |
| 93 | hdr.index_minor = htobe32(minor); |
| 94 | hdr.packet_index_len = htobe32(element_len); |
| 95 | |
| 96 | size_ret = lttng_write(fd, &hdr, sizeof(hdr)); |
| 97 | if (size_ret < sizeof(hdr)) { |
| 98 | PERROR("write index header"); |
| 99 | ret = -1; |
| 100 | goto error; |
| 101 | } |
| 102 | index_file->fd = fd; |
| 103 | index_file->major = major; |
| 104 | index_file->minor = minor; |
| 105 | index_file->element_len = element_len; |
| 106 | urcu_ref_init(&index_file->ref); |
| 107 | |
| 108 | return index_file; |
| 109 | |
| 110 | error: |
| 111 | if (fd >= 0) { |
| 112 | int close_ret; |
| 113 | |
| 114 | close_ret = close(fd); |
| 115 | if (close_ret < 0) { |
| 116 | PERROR("close index fd"); |
| 117 | } |
| 118 | } |
| 119 | free(index_file); |
| 120 | return NULL; |
| 121 | } |
| 122 | |
| 123 | /* |
| 124 | * Write index values to the given index file. |
| 125 | * |
| 126 | * Return 0 on success, -1 on error. |
| 127 | */ |
| 128 | int lttng_index_file_write(const struct lttng_index_file *index_file, |
| 129 | const struct ctf_packet_index *element) |
| 130 | { |
| 131 | ssize_t ret; |
| 132 | int fd = index_file->fd; |
| 133 | size_t len = index_file->element_len; |
| 134 | |
| 135 | assert(element); |
| 136 | |
| 137 | if (fd < 0) { |
| 138 | goto error; |
| 139 | } |
| 140 | |
| 141 | ret = lttng_write(fd, element, len); |
| 142 | if (ret < len) { |
| 143 | PERROR("writing index file"); |
| 144 | goto error; |
| 145 | } |
| 146 | return 0; |
| 147 | |
| 148 | error: |
| 149 | return -1; |
| 150 | } |
| 151 | |
| 152 | /* |
| 153 | * Read index values from the given index file. |
| 154 | * |
| 155 | * Return 0 on success, -1 on error. |
| 156 | */ |
| 157 | int lttng_index_file_read(const struct lttng_index_file *index_file, |
| 158 | struct ctf_packet_index *element) |
| 159 | { |
| 160 | ssize_t ret; |
| 161 | int fd = index_file->fd; |
| 162 | size_t len = index_file->element_len; |
| 163 | |
| 164 | assert(element); |
| 165 | |
| 166 | if (fd < 0) { |
| 167 | goto error; |
| 168 | } |
| 169 | |
| 170 | ret = lttng_read(fd, element, len); |
| 171 | if (ret < len) { |
| 172 | PERROR("read index file"); |
| 173 | goto error; |
| 174 | } |
| 175 | return 0; |
| 176 | |
| 177 | error: |
| 178 | return -1; |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * Open index file using a given path, channel name and tracefile count. |
| 183 | * |
| 184 | * Return allocated struct lttng_index_file, NULL on error. |
| 185 | */ |
| 186 | struct lttng_index_file *lttng_index_file_open(const char *path_name, |
| 187 | const char *channel_name, uint64_t tracefile_count, |
| 188 | uint64_t tracefile_count_current) |
| 189 | { |
| 190 | struct lttng_index_file *index_file; |
| 191 | int ret, read_fd; |
| 192 | ssize_t read_len; |
| 193 | char fullpath[PATH_MAX]; |
| 194 | struct ctf_packet_index_file_hdr hdr; |
| 195 | uint32_t major, minor, element_len; |
| 196 | |
| 197 | assert(path_name); |
| 198 | assert(channel_name); |
| 199 | |
| 200 | index_file = zmalloc(sizeof(*index_file)); |
| 201 | if (!index_file) { |
| 202 | PERROR("allocating lttng_index_file"); |
| 203 | goto error; |
| 204 | } |
| 205 | |
| 206 | if (tracefile_count > 0) { |
| 207 | ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s_%" |
| 208 | PRIu64 DEFAULT_INDEX_FILE_SUFFIX, path_name, |
| 209 | channel_name, tracefile_count_current); |
| 210 | } else { |
| 211 | ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s" |
| 212 | DEFAULT_INDEX_FILE_SUFFIX, path_name, channel_name); |
| 213 | } |
| 214 | if (ret < 0) { |
| 215 | PERROR("snprintf index path"); |
| 216 | goto error; |
| 217 | } |
| 218 | |
| 219 | DBG("Index opening file %s in read only", fullpath); |
| 220 | read_fd = open(fullpath, O_RDONLY); |
| 221 | if (read_fd < 0) { |
| 222 | if (errno == ENOENT) { |
| 223 | ret = -ENOENT; |
| 224 | } else { |
| 225 | PERROR("opening index in read-only"); |
| 226 | } |
| 227 | goto error; |
| 228 | } |
| 229 | |
| 230 | read_len = lttng_read(read_fd, &hdr, sizeof(hdr)); |
| 231 | if (read_len < 0) { |
| 232 | PERROR("Reading index header"); |
| 233 | goto error_close; |
| 234 | } |
| 235 | |
| 236 | if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) { |
| 237 | ERR("Invalid header magic"); |
| 238 | goto error_close; |
| 239 | } |
| 240 | major = be32toh(hdr.index_major); |
| 241 | minor = be32toh(hdr.index_minor); |
| 242 | element_len = be32toh(hdr.packet_index_len); |
| 243 | |
| 244 | if (major != CTF_INDEX_MAJOR) { |
| 245 | ERR("Invalid header version"); |
| 246 | goto error_close; |
| 247 | } |
| 248 | if (element_len > sizeof(struct ctf_packet_index)) { |
| 249 | ERR("Index element length too long"); |
| 250 | goto error_close; |
| 251 | } |
| 252 | |
| 253 | index_file->fd = read_fd; |
| 254 | index_file->major = major; |
| 255 | index_file->minor = minor; |
| 256 | index_file->element_len = element_len; |
| 257 | urcu_ref_init(&index_file->ref); |
| 258 | |
| 259 | return index_file; |
| 260 | |
| 261 | error_close: |
| 262 | if (read_fd >= 0) { |
| 263 | int close_ret; |
| 264 | |
| 265 | close_ret = close(read_fd); |
| 266 | if (close_ret < 0) { |
| 267 | PERROR("close read fd %d", read_fd); |
| 268 | } |
| 269 | } |
| 270 | ret = -1; |
| 271 | |
| 272 | error: |
| 273 | free(index_file); |
| 274 | return NULL; |
| 275 | } |
| 276 | |
| 277 | void lttng_index_file_get(struct lttng_index_file *index_file) |
| 278 | { |
| 279 | urcu_ref_get(&index_file->ref); |
| 280 | } |
| 281 | |
| 282 | static void lttng_index_file_release(struct urcu_ref *ref) |
| 283 | { |
| 284 | struct lttng_index_file *index_file = caa_container_of(ref, |
| 285 | struct lttng_index_file, ref); |
| 286 | |
| 287 | if (close(index_file->fd)) { |
| 288 | PERROR("close index fd"); |
| 289 | } |
| 290 | free(index_file); |
| 291 | } |
| 292 | |
| 293 | void lttng_index_file_put(struct lttng_index_file *index_file) |
| 294 | { |
| 295 | urcu_ref_put(&index_file->ref, lttng_index_file_release); |
| 296 | } |