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 "sd-event.h"
  37 #include "sparse-endian.h"
  38
  39 typedef struct JournalMetrics {
  40         /* For all these: -1 means "pick automatically", and 0 means "no limit enforced" */
  41         uint64_t max_size;     /* how large journal files grow at max */
  42         uint64_t min_size;     /* how large journal files grow at least */
  43         uint64_t max_use;      /* how much disk space to use in total at max, keep_free permitting */
  44         uint64_t min_use;      /* how much disk space to use in total at least, even if keep_free says not to */
  45         uint64_t keep_free;    /* how much to keep free on disk */
  46         uint64_t n_max_files;  /* how many files to keep around at max */
  47 } JournalMetrics;
  48
  49 typedef enum direction {
  50         DIRECTION_UP,
  51         DIRECTION_DOWN
  52 } direction_t;
  53
  54 typedef enum LocationType {
  55         /* The first and last entries, resp. */
  56         LOCATION_HEAD,
  57         LOCATION_TAIL,
  58
  59         /* We already read the entry we currently point to, and the
  60          * next one to read should probably not be this one again. */
  61         LOCATION_DISCRETE,
  62
  63         /* We should seek to the precise location specified, and
  64          * return it, as we haven't read it yet. */
  65         LOCATION_SEEK
  66 } LocationType;
  67
  68 typedef struct JournalFile {
  69         int fd;
  70
  71         mode_t mode;
  72
  73         int flags;
  74         int prot;
  75         bool writable:1;
  76         bool compress_xz:1;
  77         bool compress_lz4:1;
  78         bool seal:1;
  79         bool defrag_on_close:1;
  80
  81         bool tail_entry_monotonic_valid:1;
  82
  83         direction_t last_direction;
  84         LocationType location_type;
  85         uint64_t last_n_entries;
  86
  87         char *path;
  88         struct stat last_stat;
  89         usec_t last_stat_usec;
  90
  91         Header *header;
  92         HashItem *data_hash_table;
  93         HashItem *field_hash_table;
  94
  95         uint64_t current_offset;
  96         uint64_t current_seqnum;
  97         uint64_t current_realtime;
  98         uint64_t current_monotonic;
  99         sd_id128_t current_boot_id;
 100         uint64_t current_xor_hash;
 101
 102         JournalMetrics metrics;
 103         MMapCache *mmap;
 104
 105         sd_event_source *post_change_timer;
 106         usec_t post_change_timer_period;
 107
 108         OrderedHashmap *chain_cache;
 109
 110 #if defined(HAVE_XZ) || defined(HAVE_LZ4)
 111         void *compress_buffer;
 112         size_t compress_buffer_size;
 113 #endif
 114
 115 #ifdef HAVE_GCRYPT
 116         gcry_md_hd_t hmac;
 117         bool hmac_running;
 118
 119         FSSHeader *fss_file;
 120         size_t fss_file_size;
 121
 122         uint64_t fss_start_usec;
 123         uint64_t fss_interval_usec;
 124
 125         void *fsprg_state;
 126         size_t fsprg_state_size;
 127
 128         void *fsprg_seed;
 129         size_t fsprg_seed_size;
 130 #endif
 131 } JournalFile;
 132
 133 int journal_file_open(
 134                 const char *fname,
 135                 int flags,
 136                 mode_t mode,
 137                 bool compress,
 138                 bool seal,
 139                 JournalMetrics *metrics,
 140                 MMapCache *mmap_cache,
 141                 JournalFile *template,
 142                 JournalFile **ret);
 143
 144 int journal_file_set_offline(JournalFile *f);
 145 JournalFile* journal_file_close(JournalFile *j);
 146
 147 int journal_file_open_reliably(
 148                 const char *fname,
 149                 int flags,
 150                 mode_t mode,
 151                 bool compress,
 152                 bool seal,
 153                 JournalMetrics *metrics,
 154                 MMapCache *mmap_cache,
 155                 JournalFile *template,
 156                 JournalFile **ret);
 157
 158 #define ALIGN64(x) (((x) + 7ULL) & ~7ULL)
 159 #define VALID64(x) (((x) & 7ULL) == 0ULL)
 160
 161 /* Use six characters to cover the offsets common in smallish journal
 162  * files without adding too many zeros. */
 163 #define OFSfmt "%06"PRIx64
 164
 165 static inline bool VALID_REALTIME(uint64_t u) {
 166         /* This considers timestamps until the year 3112 valid. That should be plenty room... */
 167         return u > 0 && u < (1ULL << 55);
 168 }
 169
 170 static inline bool VALID_MONOTONIC(uint64_t u) {
 171         /* This considers timestamps until 1142 years of runtime valid. */
 172         return u < (1ULL << 55);
 173 }
 174
 175 static inline bool VALID_EPOCH(uint64_t u) {
 176         /* This allows changing the key for 1142 years, every usec. */
 177         return u < (1ULL << 55);
 178 }
 179
 180 #define JOURNAL_HEADER_CONTAINS(h, field) \
 181         (le64toh((h)->header_size) >= offsetof(Header, field) + sizeof((h)->field))
 182
 183 #define JOURNAL_HEADER_SEALED(h) \
 184         (!!(le32toh((h)->compatible_flags) & HEADER_COMPATIBLE_SEALED))
 185
 186 #define JOURNAL_HEADER_COMPRESSED_XZ(h) \
 187         (!!(le32toh((h)->incompatible_flags) & HEADER_INCOMPATIBLE_COMPRESSED_XZ))
 188
 189 #define JOURNAL_HEADER_COMPRESSED_LZ4(h) \
 190         (!!(le32toh((h)->incompatible_flags) & HEADER_INCOMPATIBLE_COMPRESSED_LZ4))
 191
 192 int journal_file_move_to_object(JournalFile *f, ObjectType type, uint64_t offset, Object **ret);
 193
 194 uint64_t journal_file_entry_n_items(Object *o) _pure_;
 195 uint64_t journal_file_entry_array_n_items(Object *o) _pure_;
 196 uint64_t journal_file_hash_table_n_items(Object *o) _pure_;
 197
 198 int journal_file_append_object(JournalFile *f, ObjectType type, uint64_t size, Object **ret, uint64_t *offset);
 199 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);
 200
 201 int journal_file_find_data_object(JournalFile *f, const void *data, uint64_t size, Object **ret, uint64_t *offset);
 202 int journal_file_find_data_object_with_hash(JournalFile *f, const void *data, uint64_t size, uint64_t hash, Object **ret, uint64_t *offset);
 203
 204 int journal_file_find_field_object(JournalFile *f, const void *field, uint64_t size, Object **ret, uint64_t *offset);
 205 int journal_file_find_field_object_with_hash(JournalFile *f, const void *field, uint64_t size, uint64_t hash, Object **ret, uint64_t *offset);
 206
 207 void journal_file_reset_location(JournalFile *f);
 208 void journal_file_save_location(JournalFile *f, Object *o, uint64_t offset);
 209 int journal_file_compare_locations(JournalFile *af, JournalFile *bf);
 210 int journal_file_next_entry(JournalFile *f, uint64_t p, direction_t direction, Object **ret, uint64_t *offset);
 211
 212 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);
 213
 214 int journal_file_move_to_entry_by_seqnum(JournalFile *f, uint64_t seqnum, direction_t direction, Object **ret, uint64_t *offset);
 215 int journal_file_move_to_entry_by_realtime(JournalFile *f, uint64_t realtime, direction_t direction, Object **ret, uint64_t *offset);
 216 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);
 217
 218 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);
 219 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);
 220 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);
 221 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);
 222
 223 int journal_file_copy_entry(JournalFile *from, JournalFile *to, Object *o, uint64_t p, uint64_t *seqnum, Object **ret, uint64_t *offset);
 224
 225 void journal_file_dump(JournalFile *f);
 226 void journal_file_print_header(JournalFile *f);
 227
 228 int journal_file_rotate(JournalFile **f, bool compress, bool seal);
 229
 230 void journal_file_post_change(JournalFile *f);
 231 int journal_file_enable_post_change_timer(JournalFile *f, sd_event *e, usec_t t);
 232
 233 void journal_reset_metrics(JournalMetrics *m);
 234 void journal_default_metrics(JournalMetrics *m, int fd);
 235
 236 int journal_file_get_cutoff_realtime_usec(JournalFile *f, usec_t *from, usec_t *to);
 237 int journal_file_get_cutoff_monotonic_usec(JournalFile *f, sd_id128_t boot, usec_t *from, usec_t *to);
 238
 239 bool journal_file_rotate_suggested(JournalFile *f, usec_t max_file_usec);
 240
 241 int journal_file_map_data_hash_table(JournalFile *f);
 242 int journal_file_map_field_hash_table(JournalFile *f);
 243
 244 static inline bool JOURNAL_FILE_COMPRESS(JournalFile *f) {
 245         assert(f);
 246         return f->compress_xz || f->compress_lz4;
 247 }