src/journal/journal-file.h

   1 #pragma once
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2011 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <inttypes.h>
  23
  24 #ifdef HAVE_GCRYPT
  25 #include <gcrypt.h>
  26 #endif
  27
  28 #include "sd-id128.h"
  29
  30 #include "hashmap.h"
  31 #include "journal-def.h"
  32 #include "macro.h"
  33 #include "mmap-cache.h"
  34 #include "sd-event.h"
  35 #include "sparse-endian.h"
  36
  37 typedef struct JournalMetrics {
  38         /* For all these: -1 means "pick automatically", and 0 means "no limit enforced" */
  39         uint64_t max_size;     /* how large journal files grow at max */
  40         uint64_t min_size;     /* how large journal files grow at least */
  41         uint64_t max_use;      /* how much disk space to use in total at max, keep_free permitting */
  42         uint64_t min_use;      /* how much disk space to use in total at least, even if keep_free says not to */
  43         uint64_t keep_free;    /* how much to keep free on disk */
  44         uint64_t n_max_files;  /* how many files to keep around at max */
  45 } JournalMetrics;
  46
  47 typedef enum direction {
  48         DIRECTION_UP,
  49         DIRECTION_DOWN
  50 } direction_t;
  51
  52 typedef enum LocationType {
  53         /* The first and last entries, resp. */
  54         LOCATION_HEAD,
  55         LOCATION_TAIL,
  56
  57         /* We already read the entry we currently point to, and the
  58          * next one to read should probably not be this one again. */
  59         LOCATION_DISCRETE,
  60
  61         /* We should seek to the precise location specified, and
  62          * return it, as we haven't read it yet. */
  63         LOCATION_SEEK
  64 } LocationType;
  65
  66 typedef struct JournalFile {
  67         int fd;
  68
  69         mode_t mode;
  70
  71         int flags;
  72         int prot;
  73         bool writable:1;
  74         bool compress_xz:1;
  75         bool compress_lz4:1;
  76         bool seal:1;
  77         bool defrag_on_close:1;
  78
  79         bool tail_entry_monotonic_valid:1;
  80
  81         direction_t last_direction;
  82         LocationType location_type;
  83         uint64_t last_n_entries;
  84
  85         char *path;
  86         struct stat last_stat;
  87         usec_t last_stat_usec;
  88
  89         Header *header;
  90         HashItem *data_hash_table;
  91         HashItem *field_hash_table;
  92
  93         uint64_t current_offset;
  94         uint64_t current_seqnum;
  95         uint64_t current_realtime;
  96         uint64_t current_monotonic;
  97         sd_id128_t current_boot_id;
  98         uint64_t current_xor_hash;
  99
 100         JournalMetrics metrics;
 101         MMapCache *mmap;
 102
 103         sd_event_source *post_change_timer;
 104         usec_t post_change_timer_period;
 105
 106         OrderedHashmap *chain_cache;
 107
 108 #if defined(HAVE_XZ) || defined(HAVE_LZ4)
 109         void *compress_buffer;
 110         size_t compress_buffer_size;
 111 #endif
 112
 113 #ifdef HAVE_GCRYPT
 114         gcry_md_hd_t hmac;
 115         bool hmac_running;
 116
 117         FSSHeader *fss_file;
 118         size_t fss_file_size;
 119
 120         uint64_t fss_start_usec;
 121         uint64_t fss_interval_usec;
 122
 123         void *fsprg_state;
 124         size_t fsprg_state_size;
 125
 126         void *fsprg_seed;
 127         size_t fsprg_seed_size;
 128 #endif
 129 } JournalFile;
 130
 131 int journal_file_open(
 132                 const char *fname,
 133                 int flags,
 134                 mode_t mode,
 135                 bool compress,
 136                 bool seal,
 137                 JournalMetrics *metrics,
 138                 MMapCache *mmap_cache,
 139                 JournalFile *template,
 140                 JournalFile **ret);
 141
 142 int journal_file_set_offline(JournalFile *f);
 143 JournalFile* journal_file_close(JournalFile *j);
 144
 145 int journal_file_open_reliably(
 146                 const char *fname,
 147                 int flags,
 148                 mode_t mode,
 149                 bool compress,
 150                 bool seal,
 151                 JournalMetrics *metrics,
 152                 MMapCache *mmap_cache,
 153                 JournalFile *template,
 154                 JournalFile **ret);
 155
 156 #define ALIGN64(x) (((x) + 7ULL) & ~7ULL)
 157 #define VALID64(x) (((x) & 7ULL) == 0ULL)
 158
 159 /* Use six characters to cover the offsets common in smallish journal
 160  * files without adding too many zeros. */
 161 #define OFSfmt "%06"PRIx64
 162
 163 static inline bool VALID_REALTIME(uint64_t u) {
 164         /* This considers timestamps until the year 3112 valid. That should be plenty room... */
 165         return u > 0 && u < (1ULL << 55);
 166 }
 167
 168 static inline bool VALID_MONOTONIC(uint64_t u) {
 169         /* This considers timestamps until 1142 years of runtime valid. */
 170         return u < (1ULL << 55);
 171 }
 172
 173 static inline bool VALID_EPOCH(uint64_t u) {
 174         /* This allows changing the key for 1142 years, every usec. */
 175         return u < (1ULL << 55);
 176 }
 177
 178 #define JOURNAL_HEADER_CONTAINS(h, field) \
 179         (le64toh((h)->header_size) >= offsetof(Header, field) + sizeof((h)->field))
 180
 181 #define JOURNAL_HEADER_SEALED(h) \
 182         (!!(le32toh((h)->compatible_flags) & HEADER_COMPATIBLE_SEALED))
 183
 184 #define JOURNAL_HEADER_COMPRESSED_XZ(h) \
 185         (!!(le32toh((h)->incompatible_flags) & HEADER_INCOMPATIBLE_COMPRESSED_XZ))
 186
 187 #define JOURNAL_HEADER_COMPRESSED_LZ4(h) \
 188         (!!(le32toh((h)->incompatible_flags) & HEADER_INCOMPATIBLE_COMPRESSED_LZ4))
 189
 190 int journal_file_move_to_object(JournalFile *f, ObjectType type, uint64_t offset, Object **ret);
 191
 192 uint64_t journal_file_entry_n_items(Object *o) _pure_;
 193 uint64_t journal_file_entry_array_n_items(Object *o) _pure_;
 194 uint64_t journal_file_hash_table_n_items(Object *o) _pure_;
 195
 196 int journal_file_append_object(JournalFile *f, ObjectType type, uint64_t size, Object **ret, uint64_t *offset);
 197 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);
 198
 199 int journal_file_find_data_object(JournalFile *f, const void *data, uint64_t size, Object **ret, uint64_t *offset);
 200 int journal_file_find_data_object_with_hash(JournalFile *f, const void *data, uint64_t size, uint64_t hash, Object **ret, uint64_t *offset);
 201
 202 int journal_file_find_field_object(JournalFile *f, const void *field, uint64_t size, Object **ret, uint64_t *offset);
 203 int journal_file_find_field_object_with_hash(JournalFile *f, const void *field, uint64_t size, uint64_t hash, Object **ret, uint64_t *offset);
 204
 205 void journal_file_reset_location(JournalFile *f);
 206 void journal_file_save_location(JournalFile *f, Object *o, uint64_t offset);
 207 int journal_file_compare_locations(JournalFile *af, JournalFile *bf);
 208 int journal_file_next_entry(JournalFile *f, uint64_t p, direction_t direction, Object **ret, uint64_t *offset);
 209
 210 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);
 211
 212 int journal_file_move_to_entry_by_seqnum(JournalFile *f, uint64_t seqnum, direction_t direction, Object **ret, uint64_t *offset);
 213 int journal_file_move_to_entry_by_realtime(JournalFile *f, uint64_t realtime, direction_t direction, Object **ret, uint64_t *offset);
 214 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);
 215
 216 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);
 217 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);
 218 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);
 219 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);
 220
 221 int journal_file_copy_entry(JournalFile *from, JournalFile *to, Object *o, uint64_t p, uint64_t *seqnum, Object **ret, uint64_t *offset);
 222
 223 void journal_file_dump(JournalFile *f);
 224 void journal_file_print_header(JournalFile *f);
 225
 226 int journal_file_rotate(JournalFile **f, bool compress, bool seal);
 227
 228 void journal_file_post_change(JournalFile *f);
 229 int journal_file_enable_post_change_timer(JournalFile *f, sd_event *e, usec_t t);
 230
 231 void journal_reset_metrics(JournalMetrics *m);
 232 void journal_default_metrics(JournalMetrics *m, int fd);
 233
 234 int journal_file_get_cutoff_realtime_usec(JournalFile *f, usec_t *from, usec_t *to);
 235 int journal_file_get_cutoff_monotonic_usec(JournalFile *f, sd_id128_t boot, usec_t *from, usec_t *to);
 236
 237 bool journal_file_rotate_suggested(JournalFile *f, usec_t max_file_usec);
 238
 239 int journal_file_map_data_hash_table(JournalFile *f);
 240 int journal_file_map_field_hash_table(JournalFile *f);
 241
 242 static inline bool JOURNAL_FILE_COMPRESS(JournalFile *f) {
 243         assert(f);
 244         return f->compress_xz || f->compress_lz4;
 245 }