src/common/index/index.c

   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 _GNU_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/utils.h>
  28
  29 #include "index.h"
  30
  31 /*
  32  * Create the index file associated with a trace file.
  33  *
  34  * Return fd on success, a negative value on error.
  35  */
  36 int index_create_file(char *path_name, char *stream_name, int uid, int gid,
  37                 uint64_t size, uint64_t count)
  38 {
  39         int ret, fd = -1;
  40         ssize_t size_ret;
  41         struct ctf_packet_index_file_hdr hdr;
  42         char fullpath[PATH_MAX];
  43
  44         ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR,
  45                         path_name);
  46         if (ret < 0) {
  47                 PERROR("snprintf index path");
  48                 goto error;
  49         }
  50
  51         /* Create index directory if necessary. */
  52         ret = run_as_mkdir(fullpath, S_IRWXU | S_IRWXG, uid, gid);
  53         if (ret < 0) {
  54                 if (ret != -EEXIST) {
  55                         PERROR("Index trace directory creation error");
  56                         goto error;
  57                 }
  58         }
  59
  60         ret = utils_create_stream_file(fullpath, stream_name, size, count, uid,
  61                         gid, DEFAULT_INDEX_FILE_SUFFIX);
  62         if (ret < 0) {
  63                 goto error;
  64         }
  65         fd = ret;
  66
  67         hdr.magic = htobe32(CTF_INDEX_MAGIC);
  68         hdr.index_major = htobe32(CTF_INDEX_MAJOR);
  69         hdr.index_minor = htobe32(CTF_INDEX_MINOR);
  70         hdr.packet_index_len = htobe32(sizeof(struct ctf_packet_index));
  71
  72         size_ret = lttng_write(fd, &hdr, sizeof(hdr));
  73         if (size_ret < sizeof(hdr)) {
  74                 PERROR("write index header");
  75                 ret = -1;
  76                 goto error;
  77         }
  78
  79         return fd;
  80
  81 error:
  82         if (fd >= 0) {
  83                 int close_ret;
  84
  85                 close_ret = close(fd);
  86                 if (close_ret < 0) {
  87                         PERROR("close index fd");
  88                 }
  89         }
  90         return ret;
  91 }
  92
  93 /*
  94  * Write index values to the given fd of size len.
  95  *
  96  * Return "len" on success or else < len on error. errno contains error
  97  * details.
  98  */
  99 ssize_t index_write(int fd, struct ctf_packet_index *index, size_t len)
 100 {
 101         ssize_t ret;
 102
 103         assert(index);
 104
 105         if (fd < 0) {
 106                 ret = -EINVAL;
 107                 goto error;
 108         }
 109
 110         ret = lttng_write(fd, index, len);
 111         if (ret < len) {
 112                 PERROR("writing index file");
 113         }
 114
 115 error:
 116         return ret;
 117 }
 118
 119 /*
 120  * Open index file using a given path, channel name and tracefile count.
 121  *
 122  * Return read only FD on success or else a negative value.
 123  */
 124 int index_open(const char *path_name, const char *channel_name,
 125                 uint64_t tracefile_count, uint64_t tracefile_count_current)
 126 {
 127         int ret, read_fd;
 128         ssize_t read_len;
 129         char fullpath[PATH_MAX];
 130         struct ctf_packet_index_file_hdr hdr;
 131
 132         assert(path_name);
 133         assert(channel_name);
 134
 135         if (tracefile_count > 0) {
 136                 ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s_%"
 137                                 PRIu64 DEFAULT_INDEX_FILE_SUFFIX, path_name,
 138                                 channel_name, tracefile_count_current);
 139         } else {
 140                 ret = snprintf(fullpath, sizeof(fullpath), "%s/" DEFAULT_INDEX_DIR "/%s"
 141                                 DEFAULT_INDEX_FILE_SUFFIX, path_name, channel_name);
 142         }
 143         if (ret < 0) {
 144                 PERROR("snprintf index path");
 145                 goto error;
 146         }
 147
 148         DBG("Index opening file %s in read only", fullpath);
 149         read_fd = open(fullpath, O_RDONLY);
 150         if (read_fd < 0) {
 151                 if (errno == ENOENT) {
 152                         ret = -ENOENT;
 153                 } else {
 154                         PERROR("opening index in read-only");
 155                 }
 156                 goto error;
 157         }
 158
 159         read_len = lttng_read(read_fd, &hdr, sizeof(hdr));
 160         if (read_len < 0) {
 161                 PERROR("Reading index header");
 162                 goto error_close;
 163         }
 164
 165         if (be32toh(hdr.magic) != CTF_INDEX_MAGIC) {
 166                 ERR("Invalid header magic");
 167                 goto error_close;
 168         }
 169         if (be32toh(hdr.index_major) != CTF_INDEX_MAJOR ||
 170                         be32toh(hdr.index_minor) != CTF_INDEX_MINOR) {
 171                 ERR("Invalid header version");
 172                 goto error_close;
 173         }
 174
 175         return read_fd;
 176
 177 error_close:
 178         if (read_fd >= 0) {
 179                 int close_ret;
 180
 181                 close_ret = close(read_fd);
 182                 if (close_ret < 0) {
 183                         PERROR("close read fd %d", read_fd);
 184                 }
 185         }
 186         ret = -1;
 187
 188 error:
 189         return ret;
 190 }