src/journal/journal-file.h

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 #pragma once
   4
   5 /***
   6   This file is part of systemd.
   7
   8   Copyright 2011 Lennart Poettering
   9
  10   systemd is free software; you can redistribute it and/or modify it
  11   under the terms of the GNU Lesser General Public License as published by
  12   the Free Software Foundation; either version 2.1 of the License, or
  13   (at your option) any later version.
  14
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 ***/
  23
  24 #include <inttypes.h>
  25
  26 #ifdef HAVE_GCRYPT
  27 #include <gcrypt.h>
  28 #endif
  29
  30 #include "sd-id128.h"
  31
  32 #include "hashmap.h"
  33 #include "journal-def.h"
  34 #include "macro.h"
  35 #include "mmap-cache.h"
  36 #include "sparse-endian.h"
  37
  38 typedef struct JournalMetrics {
  39         /* For all these: -1 means "pick automatically", and 0 means "no limit enforced" */
  40         uint64_t max_size;     /* how large journal files grow at max */
  41         uint64_t min_size;     /* how large journal files grow at least */
  42         uint64_t max_use;      /* how much disk space to use in total at max, keep_free permitting */
  43         uint64_t min_use;      /* how much disk space to use in total at least, even if keep_free says not to */
  44         uint64_t keep_free;    /* how much to keep free on disk */
  45         uint64_t n_max_files;  /* how many files to keep around at max */
  46 } JournalMetrics;
  47
  48 typedef enum direction {
  49         DIRECTION_UP,
  50         DIRECTION_DOWN
  51 } direction_t;
  52
  53 typedef enum LocationType {
  54         /* The first and last entries, resp. */
  55         LOCATION_HEAD,
  56         LOCATION_TAIL,
  57
  58         /* We already read the entry we currently point to, and the
  59          * next one to read should probably not be this one again. */
  60         LOCATION_DISCRETE,
  61
  62         /* We should seek to the precise location specified, and
  63          * return it, as we haven't read it yet. */
  64         LOCATION_SEEK
  65 } LocationType;
  66
  67 typedef struct JournalFile {
  68         int fd;
  69
  70         mode_t mode;
  71
  72         int flags;
  73         int prot;
  74         bool writable:1;
  75         bool compress_xz:1;
  76         bool compress_lz4:1;
  77         bool seal:1;
  78         bool defrag_on_close:1;
  79
  80         bool tail_entry_monotonic_valid:1;
  81
  82         direction_t last_direction;
  83         LocationType location_type;
  84         uint64_t last_n_entries;
  85
  86         char *path;
  87         struct stat last_stat;
  88         usec_t last_stat_usec;
  89
  90         Header *header;
  91         HashItem *data_hash_table;
  92         HashItem *field_hash_table;
  93
  94         uint64_t current_offset;
  95         uint64_t current_seqnum;
  96         uint64_t current_realtime;
  97         uint64_t current_monotonic;
  98         sd_id128_t current_boot_id;
  99         uint64_t current_xor_hash;
 100
 101         JournalMetrics metrics;
 102         MMapCache *mmap;
 103
 104         OrderedHashmap *chain_cache;
 105
 106 #if defined(HAVE_XZ) || defined(HAVE_LZ4)
 107         void *compress_buffer;
 108         size_t compress_buffer_size;
 109 #endif
 110
 111 #ifdef HAVE_GCRYPT
 112         gcry_md_hd_t hmac;
 113         bool hmac_running;
 114
 115         FSSHeader *fss_file;
 116         size_t fss_file_size;
 117
 118         uint64_t fss_start_usec;
 119         uint64_t fss_interval_usec;
 120
 121         void *fsprg_state;
 122         size_t fsprg_state_size;
 123
 124         void *fsprg_seed;
 125         size_t fsprg_seed_size;
 126 #endif
 127 } JournalFile;
 128
 129 int journal_file_open(
 130                 const char *fname,
 131                 int flags,
 132                 mode_t mode,
 133                 bool compress,
 134                 bool seal,
 135                 JournalMetrics *metrics,
 136                 MMapCache *mmap_cache,
 137                 JournalFile *template,
 138                 JournalFile **ret);
 139
 140 int journal_file_set_offline(JournalFile *f);
 141 JournalFile* journal_file_close(JournalFile *j);
 142
 143 int journal_file_open_reliably(
 144                 const char *fname,
 145                 int flags,
 146                 mode_t mode,
 147                 bool compress,
 148                 bool seal,
 149                 JournalMetrics *metrics,
 150                 MMapCache *mmap_cache,
 151                 JournalFile *template,
 152                 JournalFile **ret);
 153
 154 #define ALIGN64(x) (((x) + 7ULL) & ~7ULL)
 155 #define VALID64(x) (((x) & 7ULL) == 0ULL)
 156
 157 /* Use six characters to cover the offsets common in smallish journal
 158  * files without adding too many zeros. */
 159 #define OFSfmt "%06"PRIx64
 160
 161 static inline bool VALID_REALTIME(uint64_t u) {
 162         /* This considers timestamps until the year 3112 valid. That should be plenty room... */
 163         return u > 0 && u < (1ULL << 55);
 164 }
 165
 166 static inline bool VALID_MONOTONIC(uint64_t u) {
 167         /* This considers timestamps until 1142 years of runtime valid. */
 168         return u < (1ULL << 55);
 169 }
 170
 171 static inline bool VALID_EPOCH(uint64_t u) {
 172         /* This allows changing the key for 1142 years, every usec. */
 173         return u < (1ULL << 55);
 174 }
 175
 176 #define JOURNAL_HEADER_CONTAINS(h, field) \
 177         (le64toh((h)->header_size) >= offsetof(Header, field) + sizeof((h)->field))
 178
 179 #define JOURNAL_HEADER_SEALED(h) \
 180         (!!(le32toh((h)->compatible_flags) & HEADER_COMPATIBLE_SEALED))
 181
 182 #define JOURNAL_HEADER_COMPRESSED_XZ(h) \
 183         (!!(le32toh((h)->incompatible_flags) & HEADER_INCOMPATIBLE_COMPRESSED_XZ))
 184
 185 #define JOURNAL_HEADER_COMPRESSED_LZ4(h) \
 186         (!!(le32toh((h)->incompatible_flags) & HEADER_INCOMPATIBLE_COMPRESSED_LZ4))
 187
 188 int journal_file_move_to_object(JournalFile *f, ObjectType type, uint64_t offset, Object **ret);
 189
 190 uint64_t journal_file_entry_n_items(Object *o) _pure_;
 191 uint64_t journal_file_entry_array_n_items(Object *o) _pure_;
 192 uint64_t journal_file_hash_table_n_items(Object *o) _pure_;
 193
 194 int journal_file_append_object(JournalFile *f, ObjectType type, uint64_t size, Object **ret, uint64_t *offset);
 195 int journal_file_append_entry(JournalFile *f, const dual_timestamp *ts, const struct iovec iovec[], unsigned n_iovec, uint64_t *seqno, Object **ret, uint64_t *offset);
 196
 197 int journal_file_find_data_object(JournalFile *f, const void *data, uint64_t size, Object **ret, uint64_t *offset);
 198 int journal_file_find_data_object_with_hash(JournalFile *f, const void *data, uint64_t size, uint64_t hash, Object **ret, uint64_t *offset);
 199
 200 int journal_file_find_field_object(JournalFile *f, const void *field, uint64_t size, Object **ret, uint64_t *offset);
 201 int journal_file_find_field_object_with_hash(JournalFile *f, const void *field, uint64_t size, uint64_t hash, Object **ret, uint64_t *offset);
 202
 203 void journal_file_reset_location(JournalFile *f);
 204 void journal_file_save_location(JournalFile *f, Object *o, uint64_t offset);
 205 int journal_file_compare_locations(JournalFile *af, JournalFile *bf);
 206 int journal_file_next_entry(JournalFile *f, uint64_t p, direction_t direction, Object **ret, uint64_t *offset);
 207
 208 int journal_file_next_entry_for_data(JournalFile *f, Object *o, uint64_t p, uint64_t data_offset, direction_t direction, Object **ret, uint64_t *offset);
 209
 210 int journal_file_move_to_entry_by_seqnum(JournalFile *f, uint64_t seqnum, direction_t direction, Object **ret, uint64_t *offset);
 211 int journal_file_move_to_entry_by_realtime(JournalFile *f, uint64_t realtime, direction_t direction, Object **ret, uint64_t *offset);
 212 int journal_file_move_to_entry_by_monotonic(JournalFile *f, sd_id128_t boot_id, uint64_t monotonic, direction_t direction, Object **ret, uint64_t *offset);
 213
 214 int journal_file_move_to_entry_by_offset_for_data(JournalFile *f, uint64_t data_offset, uint64_t p, direction_t direction, Object **ret, uint64_t *offset);
 215 int journal_file_move_to_entry_by_seqnum_for_data(JournalFile *f, uint64_t data_offset, uint64_t seqnum, direction_t direction, Object **ret, uint64_t *offset);
 216 int journal_file_move_to_entry_by_realtime_for_data(JournalFile *f, uint64_t data_offset, uint64_t realtime, direction_t direction, Object **ret, uint64_t *offset);
 217 int journal_file_move_to_entry_by_monotonic_for_data(JournalFile *f, uint64_t data_offset, sd_id128_t boot_id, uint64_t monotonic, direction_t direction, Object **ret, uint64_t *offset);
 218
 219 int journal_file_copy_entry(JournalFile *from, JournalFile *to, Object *o, uint64_t p, uint64_t *seqnum, Object **ret, uint64_t *offset);
 220
 221 void journal_file_dump(JournalFile *f);
 222 void journal_file_print_header(JournalFile *f);
 223
 224 int journal_file_rotate(JournalFile **f, bool compress, bool seal);
 225
 226 void journal_file_post_change(JournalFile *f);
 227
 228 void journal_reset_metrics(JournalMetrics *m);
 229 void journal_default_metrics(JournalMetrics *m, int fd);
 230
 231 int journal_file_get_cutoff_realtime_usec(JournalFile *f, usec_t *from, usec_t *to);
 232 int journal_file_get_cutoff_monotonic_usec(JournalFile *f, sd_id128_t boot, usec_t *from, usec_t *to);
 233
 234 bool journal_file_rotate_suggested(JournalFile *f, usec_t max_file_usec);
 235
 236 int journal_file_map_data_hash_table(JournalFile *f);
 237 int journal_file_map_field_hash_table(JournalFile *f);
 238
 239 static inline bool JOURNAL_FILE_COMPRESS(JournalFile *f) {
 240         assert(f);
 241         return f->compress_xz || f->compress_lz4;
 242 }