| 1 | /* |
| 2 | * Copyright (C) 2013 - Julien Desfossez <jdesfossez@efficios.com> |
| 3 | * David Goulet <dgoulet@efficios.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License, version 2 only, as |
| 7 | * published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License along with |
| 15 | * this program; if not, write to the Free Software Foundation, Inc., 51 |
| 16 | * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #define _LGPL_SOURCE |
| 20 | #include <assert.h> |
| 21 | #include <sys/stat.h> |
| 22 | #include <sys/types.h> |
| 23 | #include <fcntl.h> |
| 24 | |
| 25 | #include <common/common.h> |
| 26 | #include <common/defaults.h> |
| 27 | #include <common/compat/endian.h> |
| 28 | #include <common/utils.h> |
| 29 | |
| 30 | #include "index.h" |
| 31 | |
| 32 | /* |
| 33 | * Create the index file associated with a trace file. |
| 34 | * |
| 35 | * Return fd on success, a negative value on error. |
| 36 | */ |
| 37 | int index_create_file(char *path_name, char *stream_name, int uid, int gid, |
| 38 | uint64_t size, uint64_t count) |
| 39 | { |
| 40 | int ret, fd = -1; |
| 41 | ssize_t size_ret; |
| 42 | struct ctf_packet_index_file_hdr hdr; |
| 43 | char fullpath[PATH_MAX]; |
| 44 | |
| 45 | ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR, |
| 46 | path_name); |
| 47 | if (ret < 0) { |
| 48 | PERROR("snprintf index path"); |
| 49 | goto error; |
| 50 | } |
| 51 | |
| 52 | /* Create index directory if necessary. */ |
| 53 | ret = utils_mkdir(fullpath, S_IRWXU | S_IRWXG, uid, gid); |
| 54 | if (ret < 0) { |
| 55 | if (errno != EEXIST) { |
| 56 | PERROR("Index trace directory creation error"); |
| 57 | goto error; |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | /* |
| 62 | * For tracefile rotation. We need to unlink the old |
| 63 | * file if present to synchronize with the tail of the |
| 64 | * live viewer which could be working on this same file. |
| 65 | * By doing so, any reference to the old index file |
| 66 | * stays valid even if we re-create a new file with the |
| 67 | * same name afterwards. |
| 68 | */ |
| 69 | ret = utils_unlink_stream_file(fullpath, stream_name, size, count, uid, |
| 70 | gid, DEFAULT_INDEX_FILE_SUFFIX); |
| 71 | if (ret < 0 && errno != ENOENT) { |
| 72 | goto error; |
| 73 | } |
| 74 | ret = utils_create_stream_file(fullpath, stream_name, size, count, uid, |
| 75 | gid, DEFAULT_INDEX_FILE_SUFFIX); |
| 76 | if (ret < 0) { |
| 77 | goto error; |
| 78 | } |
| 79 | fd = ret; |
| 80 | |
| 81 | hdr.magic = htobe32(CTF_INDEX_MAGIC); |
| 82 | hdr.index_major = htobe32(CTF_INDEX_MAJOR); |
| 83 | hdr.index_minor = htobe32(CTF_INDEX_MINOR); |
| 84 | hdr.packet_index_len = htobe32(sizeof(struct ctf_packet_index)); |
| 85 | |
| 86 | size_ret = lttng_write(fd, &hdr, sizeof(hdr)); |
| 87 | if (size_ret < sizeof(hdr)) { |
| 88 | PERROR("write index header"); |
| 89 | ret = -1; |
| 90 | goto error; |
| 91 | } |
| 92 | |
| 93 | return fd; |
| 94 | |
| 95 | error: |
| 96 | if (fd >= 0) { |
| 97 | int close_ret; |
| 98 | |
| 99 | close_ret = close(fd); |
| 100 | if (close_ret < 0) { |
| 101 | PERROR("close index fd"); |
| 102 | } |
| 103 | } |
| 104 | return ret; |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * Write index values to the given fd of size len. |
| 109 | * |
| 110 | * Return "len" on success or else < len on error. errno contains error |
| 111 | * details. |
| 112 | */ |
| 113 | ssize_t index_write(int fd, struct ctf_packet_index *index, size_t len) |
| 114 | { |
| 115 | ssize_t ret; |
| 116 | |
| 117 | assert(index); |
| 118 | |
| 119 | if (fd < 0) { |
| 120 | ret = -EINVAL; |
| 121 | goto error; |
| 122 | } |
| 123 | |
| 124 | ret = lttng_write(fd, index, len); |
| 125 | if (ret < len) { |
| 126 | PERROR("writing index file"); |
| 127 | } |
| 128 | |
| 129 | error: |
| 130 | return ret; |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * Open index file using a given path, channel name and tracefile count. |
| 135 | * |
| 136 | * Return read only FD on success or else a negative value. |
| 137 | */ |
| 138 | int index_open(const char *path_name, const char *channel_name, |
| 139 | uint64_t tracefile_count, uint64_t tracefile_count_current) |
| 140 | { |
| 141 | int ret, read_fd; |
| 142 | ssize_t read_len; |
| 143 | char fullpath[PATH_MAX]; |
| 144 | struct ctf_packet_index_file_hdr hdr; |
| 145 | |
| 146 | assert(path_name); |
| 147 | assert(channel_name); |
| 148 | |
| 149 | if (tracefile_count > 0) { |
| 150 | ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s_%" |
| 151 | PRIu64 DEFAULT_INDEX_FILE_SUFFIX, path_name, |
| 152 | channel_name, tracefile_count_current); |
| 153 | } else { |
| 154 | ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s" |
| 155 | DEFAULT_INDEX_FILE_SUFFIX, path_name, channel_name); |
| 156 | } |
| 157 | if (ret < 0) { |
| 158 | PERROR("snprintf index path"); |
| 159 | goto error; |
| 160 | } |
| 161 | |
| 162 | DBG("Index opening file %s in read only", fullpath); |
| 163 | read_fd = open(fullpath, O_RDONLY); |
| 164 | if (read_fd < 0) { |
| 165 | if (errno == ENOENT) { |
| 166 | ret = -ENOENT; |
| 167 | } else { |
| 168 | PERROR("opening index in read-only"); |
| 169 | } |
| 170 | goto error; |
| 171 | } |
| 172 | |
| 173 | read_len = lttng_read(read_fd, &hdr, sizeof(hdr)); |
| 174 | if (read_len < 0) { |
| 175 | PERROR("Reading index header"); |
| 176 | goto error_close; |
| 177 | } |
| 178 | |
| 179 | if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) { |
| 180 | ERR("Invalid header magic"); |
| 181 | goto error_close; |
| 182 | } |
| 183 | if (be32toh(hdr.index_major) != CTF_INDEX_MAJOR || |
| 184 | be32toh(hdr.index_minor) != CTF_INDEX_MINOR) { |
| 185 | ERR("Invalid header version"); |
| 186 | goto error_close; |
| 187 | } |
| 188 | |
| 189 | return read_fd; |
| 190 | |
| 191 | error_close: |
| 192 | if (read_fd >= 0) { |
| 193 | int close_ret; |
| 194 | |
| 195 | close_ret = close(read_fd); |
| 196 | if (close_ret < 0) { |
| 197 | PERROR("close read fd %d", read_fd); |
| 198 | } |
| 199 | } |
| 200 | ret = -1; |
| 201 | |
| 202 | error: |
| 203 | return ret; |
| 204 | } |