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Diffstat (limited to '')
| -rw-r--r-- | src/libsystemd/sd-journal/journal-file.c | 4255 |
1 files changed, 4255 insertions, 0 deletions
diff --git a/src/libsystemd/sd-journal/journal-file.c b/src/libsystemd/sd-journal/journal-file.c new file mode 100644 index 0000000..d3a9505 --- /dev/null +++ b/src/libsystemd/sd-journal/journal-file.c @@ -0,0 +1,4255 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <fcntl.h> +#include <linux/fs.h> +#include <linux/magic.h> +#include <pthread.h> +#include <stddef.h> +#include <sys/mman.h> +#include <sys/statvfs.h> +#include <sys/uio.h> +#include <unistd.h> + +#include "sd-event.h" + +#include "alloc-util.h" +#include "chattr-util.h" +#include "compress.h" +#include "env-util.h" +#include "fd-util.h" +#include "format-util.h" +#include "fs-util.h" +#include "journal-authenticate.h" +#include "journal-def.h" +#include "journal-file.h" +#include "lookup3.h" +#include "memory-util.h" +#include "path-util.h" +#include "random-util.h" +#include "set.h" +#include "sort-util.h" +#include "stat-util.h" +#include "string-table.h" +#include "string-util.h" +#include "strv.h" +#include "sync-util.h" +#include "xattr-util.h" + +#define DEFAULT_DATA_HASH_TABLE_SIZE (2047ULL*sizeof(HashItem)) +#define DEFAULT_FIELD_HASH_TABLE_SIZE (333ULL*sizeof(HashItem)) + +#define DEFAULT_COMPRESS_THRESHOLD (512ULL) +#define MIN_COMPRESS_THRESHOLD (8ULL) + +/* This is the minimum journal file size */ +#define JOURNAL_FILE_SIZE_MIN (512 * 1024ULL) /* 512 KiB */ +#define JOURNAL_COMPACT_SIZE_MAX UINT32_MAX /* 4 GiB */ + +/* These are the lower and upper bounds if we deduce the max_use value + * from the file system size */ +#define MAX_USE_LOWER (1 * 1024 * 1024ULL) /* 1 MiB */ +#define MAX_USE_UPPER (4 * 1024 * 1024 * 1024ULL) /* 4 GiB */ + +/* Those are the lower and upper bounds for the minimal use limit, + * i.e. how much we'll use even if keep_free suggests otherwise. */ +#define MIN_USE_LOW (1 * 1024 * 1024ULL) /* 1 MiB */ +#define MIN_USE_HIGH (16 * 1024 * 1024ULL) /* 16 MiB */ + +/* This is the upper bound if we deduce max_size from max_use */ +#define MAX_SIZE_UPPER (128 * 1024 * 1024ULL) /* 128 MiB */ + +/* This is the upper bound if we deduce the keep_free value from the + * file system size */ +#define KEEP_FREE_UPPER (4 * 1024 * 1024 * 1024ULL) /* 4 GiB */ + +/* This is the keep_free value when we can't determine the system + * size */ +#define DEFAULT_KEEP_FREE (1024 * 1024ULL) /* 1 MB */ + +/* This is the default maximum number of journal files to keep around. */ +#define DEFAULT_N_MAX_FILES 100 + +/* n_data was the first entry we added after the initial file format design */ +#define HEADER_SIZE_MIN ALIGN64(offsetof(Header, n_data)) + +/* How many entries to keep in the entry array chain cache at max */ +#define CHAIN_CACHE_MAX 20 + +/* How much to increase the journal file size at once each time we allocate something new. */ +#define FILE_SIZE_INCREASE (8 * 1024 * 1024ULL) /* 8MB */ + +/* Reread fstat() of the file for detecting deletions at least this often */ +#define LAST_STAT_REFRESH_USEC (5*USEC_PER_SEC) + +/* The mmap context to use for the header we pick as one above the last defined typed */ +#define CONTEXT_HEADER _OBJECT_TYPE_MAX + +/* Longest hash chain to rotate after */ +#define HASH_CHAIN_DEPTH_MAX 100 + +#ifdef __clang__ +# pragma GCC diagnostic ignored "-Waddress-of-packed-member" +#endif + +int journal_file_tail_end_by_pread(JournalFile *f, uint64_t *ret_offset) { + uint64_t p; + int r; + + assert(f); + assert(f->header); + assert(ret_offset); + + /* Same as journal_file_tail_end_by_mmap() below, but operates with pread() to avoid the mmap cache + * (and thus is thread safe) */ + + p = le64toh(f->header->tail_object_offset); + if (p == 0) + p = le64toh(f->header->header_size); + else { + Object tail; + uint64_t sz; + + r = journal_file_read_object_header(f, OBJECT_UNUSED, p, &tail); + if (r < 0) + return r; + + sz = le64toh(tail.object.size); + if (sz > UINT64_MAX - sizeof(uint64_t) + 1) + return -EBADMSG; + + sz = ALIGN64(sz); + if (p > UINT64_MAX - sz) + return -EBADMSG; + + p += sz; + } + + *ret_offset = p; + + return 0; +} + +int journal_file_tail_end_by_mmap(JournalFile *f, uint64_t *ret_offset) { + uint64_t p; + int r; + + assert(f); + assert(f->header); + assert(ret_offset); + + /* Same as journal_file_tail_end_by_pread() above, but operates with the usual mmap logic */ + + p = le64toh(f->header->tail_object_offset); + if (p == 0) + p = le64toh(f->header->header_size); + else { + Object *tail; + uint64_t sz; + + r = journal_file_move_to_object(f, OBJECT_UNUSED, p, &tail); + if (r < 0) + return r; + + sz = le64toh(READ_NOW(tail->object.size)); + if (sz > UINT64_MAX - sizeof(uint64_t) + 1) + return -EBADMSG; + + sz = ALIGN64(sz); + if (p > UINT64_MAX - sz) + return -EBADMSG; + + p += sz; + } + + *ret_offset = p; + + return 0; +} + +int journal_file_set_offline_thread_join(JournalFile *f) { + int r; + + assert(f); + + if (f->offline_state == OFFLINE_JOINED) + return 0; + + r = pthread_join(f->offline_thread, NULL); + if (r) + return -r; + + f->offline_state = OFFLINE_JOINED; + + if (mmap_cache_fd_got_sigbus(f->cache_fd)) + return -EIO; + + return 0; +} + +static int journal_file_set_online(JournalFile *f) { + bool wait = true; + + assert(f); + + if (!journal_file_writable(f)) + return -EPERM; + + if (f->fd < 0 || !f->header) + return -EINVAL; + + while (wait) { + switch (f->offline_state) { + case OFFLINE_JOINED: + /* No offline thread, no need to wait. */ + wait = false; + break; + + case OFFLINE_SYNCING: { + OfflineState tmp_state = OFFLINE_SYNCING; + if (!__atomic_compare_exchange_n(&f->offline_state, &tmp_state, OFFLINE_CANCEL, + false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) + continue; + } + /* Canceled syncing prior to offlining, no need to wait. */ + wait = false; + break; + + case OFFLINE_AGAIN_FROM_SYNCING: { + OfflineState tmp_state = OFFLINE_AGAIN_FROM_SYNCING; + if (!__atomic_compare_exchange_n(&f->offline_state, &tmp_state, OFFLINE_CANCEL, + false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) + continue; + } + /* Canceled restart from syncing, no need to wait. */ + wait = false; + break; + + case OFFLINE_AGAIN_FROM_OFFLINING: { + OfflineState tmp_state = OFFLINE_AGAIN_FROM_OFFLINING; + if (!__atomic_compare_exchange_n(&f->offline_state, &tmp_state, OFFLINE_CANCEL, + false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) + continue; + } + /* Canceled restart from offlining, must wait for offlining to complete however. */ + _fallthrough_; + default: { + int r; + + r = journal_file_set_offline_thread_join(f); + if (r < 0) + return r; + + wait = false; + break; + } + } + } + + if (mmap_cache_fd_got_sigbus(f->cache_fd)) + return -EIO; + + switch (f->header->state) { + case STATE_ONLINE: + return 0; + + case STATE_OFFLINE: + f->header->state = STATE_ONLINE; + (void) fsync(f->fd); + return 0; + + default: + return -EINVAL; + } +} + +JournalFile* journal_file_close(JournalFile *f) { + if (!f) + return NULL; + + if (f->cache_fd) + mmap_cache_fd_free(f->cache_fd); + + if (f->close_fd) + safe_close(f->fd); + free(f->path); + + ordered_hashmap_free_free(f->chain_cache); + +#if HAVE_COMPRESSION + free(f->compress_buffer); +#endif + +#if HAVE_GCRYPT + if (f->fss_file) + munmap(f->fss_file, PAGE_ALIGN(f->fss_file_size)); + else + free(f->fsprg_state); + + free(f->fsprg_seed); + + if (f->hmac) + gcry_md_close(f->hmac); +#endif + + return mfree(f); +} + +static bool keyed_hash_requested(void) { + int r; + + r = getenv_bool("SYSTEMD_JOURNAL_KEYED_HASH"); + if (r >= 0) + return r; + if (r != -ENXIO) + log_debug_errno(r, "Failed to parse $SYSTEMD_JOURNAL_KEYED_HASH environment variable, ignoring: %m"); + + return true; +} + +static bool compact_mode_requested(void) { + int r; + + r = getenv_bool("SYSTEMD_JOURNAL_COMPACT"); + if (r >= 0) + return r; + if (r != -ENXIO) + log_debug_errno(r, "Failed to parse $SYSTEMD_JOURNAL_COMPACT environment variable, ignoring: %m"); + + return true; +} + +static int journal_file_init_header(JournalFile *f, JournalFileFlags file_flags, JournalFile *template) { + Header h = {}; + ssize_t k; + bool seal = false; + int r; + + assert(f); + +#if HAVE_GCRYPT + /* Try to load the FSPRG state, and if we can't, then just don't do sealing */ + seal = FLAGS_SET(file_flags, JOURNAL_SEAL) && journal_file_fss_load(f) >= 0; +#endif + + memcpy(h.signature, HEADER_SIGNATURE, 8); + h.header_size = htole64(ALIGN64(sizeof(h))); + + h.incompatible_flags |= htole32( + FLAGS_SET(file_flags, JOURNAL_COMPRESS) * + COMPRESSION_TO_HEADER_INCOMPATIBLE_FLAG(DEFAULT_COMPRESSION) | + keyed_hash_requested() * HEADER_INCOMPATIBLE_KEYED_HASH | + compact_mode_requested() * HEADER_INCOMPATIBLE_COMPACT); + + h.compatible_flags = htole32(seal * HEADER_COMPATIBLE_SEALED); + + r = sd_id128_randomize(&h.file_id); + if (r < 0) + return r; + + if (template) { + h.seqnum_id = template->header->seqnum_id; + h.tail_entry_seqnum = template->header->tail_entry_seqnum; + } else + h.seqnum_id = h.file_id; + + k = pwrite(f->fd, &h, sizeof(h), 0); + if (k < 0) + return -errno; + + if (k != sizeof(h)) + return -EIO; + + return 0; +} + +static int journal_file_refresh_header(JournalFile *f) { + int r; + + assert(f); + assert(f->header); + + r = sd_id128_get_machine(&f->header->machine_id); + if (IN_SET(r, -ENOENT, -ENOMEDIUM, -ENOPKG)) + /* We don't have a machine-id, let's continue without */ + zero(f->header->machine_id); + else if (r < 0) + return r; + + r = sd_id128_get_boot(&f->header->boot_id); + if (r < 0) + return r; + + r = journal_file_set_online(f); + + /* Sync the online state to disk; likely just created a new file, also sync the directory this file + * is located in. */ + (void) fsync_full(f->fd); + + return r; +} + +static bool warn_wrong_flags(const JournalFile *f, bool compatible) { + const uint32_t any = compatible ? HEADER_COMPATIBLE_ANY : HEADER_INCOMPATIBLE_ANY, + supported = compatible ? HEADER_COMPATIBLE_SUPPORTED : HEADER_INCOMPATIBLE_SUPPORTED; + const char *type = compatible ? "compatible" : "incompatible"; + uint32_t flags; + + assert(f); + assert(f->header); + + flags = le32toh(compatible ? f->header->compatible_flags : f->header->incompatible_flags); + + if (flags & ~supported) { + if (flags & ~any) + log_debug("Journal file %s has unknown %s flags 0x%"PRIx32, + f->path, type, flags & ~any); + flags = (flags & any) & ~supported; + if (flags) { + const char* strv[6]; + size_t n = 0; + _cleanup_free_ char *t = NULL; + + if (compatible) { + if (flags & HEADER_COMPATIBLE_SEALED) + strv[n++] = "sealed"; + } else { + if (flags & HEADER_INCOMPATIBLE_COMPRESSED_XZ) + strv[n++] = "xz-compressed"; + if (flags & HEADER_INCOMPATIBLE_COMPRESSED_LZ4) + strv[n++] = "lz4-compressed"; + if (flags & HEADER_INCOMPATIBLE_COMPRESSED_ZSTD) + strv[n++] = "zstd-compressed"; + if (flags & HEADER_INCOMPATIBLE_KEYED_HASH) + strv[n++] = "keyed-hash"; + if (flags & HEADER_INCOMPATIBLE_COMPACT) + strv[n++] = "compact"; + } + strv[n] = NULL; + assert(n < ELEMENTSOF(strv)); + + t = strv_join((char**) strv, ", "); + log_debug("Journal file %s uses %s %s %s disabled at compilation time.", + f->path, type, n > 1 ? "flags" : "flag", strnull(t)); + } + return true; + } + + return false; +} + +static int journal_file_verify_header(JournalFile *f) { + uint64_t arena_size, header_size; + + assert(f); + assert(f->header); + + if (memcmp(f->header->signature, HEADER_SIGNATURE, 8)) + return -EBADMSG; + + /* In both read and write mode we refuse to open files with incompatible + * flags we don't know. */ + if (warn_wrong_flags(f, false)) + return -EPROTONOSUPPORT; + + /* When open for writing we refuse to open files with compatible flags, too. */ + if (journal_file_writable(f) && warn_wrong_flags(f, true)) + return -EPROTONOSUPPORT; + + if (f->header->state >= _STATE_MAX) + return -EBADMSG; + + header_size = le64toh(READ_NOW(f->header->header_size)); + + /* The first addition was n_data, so check that we are at least this large */ + if (header_size < HEADER_SIZE_MIN) + return -EBADMSG; + + if (JOURNAL_HEADER_SEALED(f->header) && !JOURNAL_HEADER_CONTAINS(f->header, n_entry_arrays)) + return -EBADMSG; + + arena_size = le64toh(READ_NOW(f->header->arena_size)); + + if (UINT64_MAX - header_size < arena_size || header_size + arena_size > (uint64_t) f->last_stat.st_size) + return -ENODATA; + + if (le64toh(f->header->tail_object_offset) > header_size + arena_size) + return -ENODATA; + + if (!VALID64(le64toh(f->header->data_hash_table_offset)) || + !VALID64(le64toh(f->header->field_hash_table_offset)) || + !VALID64(le64toh(f->header->tail_object_offset)) || + !VALID64(le64toh(f->header->entry_array_offset))) + return -ENODATA; + + if (journal_file_writable(f)) { + sd_id128_t machine_id; + uint8_t state; + int r; + + r = sd_id128_get_machine(&machine_id); + if (r < 0) + return r; + + if (!sd_id128_equal(machine_id, f->header->machine_id)) + return -EHOSTDOWN; + + state = f->header->state; + + if (state == STATE_ARCHIVED) + return -ESHUTDOWN; /* Already archived */ + else if (state == STATE_ONLINE) + return log_debug_errno(SYNTHETIC_ERRNO(EBUSY), + "Journal file %s is already online. Assuming unclean closing.", + f->path); + else if (state != STATE_OFFLINE) + return log_debug_errno(SYNTHETIC_ERRNO(EBUSY), + "Journal file %s has unknown state %i.", + f->path, state); + + if (f->header->field_hash_table_size == 0 || f->header->data_hash_table_size == 0) + return -EBADMSG; + + /* Don't permit appending to files from the future. Because otherwise the realtime timestamps wouldn't + * be strictly ordered in the entries in the file anymore, and we can't have that since it breaks + * bisection. */ + if (le64toh(f->header->tail_entry_realtime) > now(CLOCK_REALTIME)) + return log_debug_errno(SYNTHETIC_ERRNO(ETXTBSY), + "Journal file %s is from the future, refusing to append new data to it that'd be older.", + f->path); + } + + return 0; +} + +int journal_file_fstat(JournalFile *f) { + int r; + + assert(f); + assert(f->fd >= 0); + + if (fstat(f->fd, &f->last_stat) < 0) + return -errno; + + f->last_stat_usec = now(CLOCK_MONOTONIC); + + /* Refuse dealing with files that aren't regular */ + r = stat_verify_regular(&f->last_stat); + if (r < 0) + return r; + + /* Refuse appending to files that are already deleted */ + if (f->last_stat.st_nlink <= 0) + return -EIDRM; + + return 0; +} + +static int journal_file_allocate(JournalFile *f, uint64_t offset, uint64_t size) { + uint64_t old_size, new_size, old_header_size, old_arena_size; + int r; + + assert(f); + assert(f->header); + + /* We assume that this file is not sparse, and we know that for sure, since we always call + * posix_fallocate() ourselves */ + + if (size > PAGE_ALIGN_DOWN(UINT64_MAX) - offset) + return -EINVAL; + + if (mmap_cache_fd_got_sigbus(f->cache_fd)) + return -EIO; + + old_header_size = le64toh(READ_NOW(f->header->header_size)); + old_arena_size = le64toh(READ_NOW(f->header->arena_size)); + if (old_arena_size > PAGE_ALIGN_DOWN(UINT64_MAX) - old_header_size) + return -EBADMSG; + + old_size = old_header_size + old_arena_size; + + new_size = MAX(PAGE_ALIGN(offset + size), old_header_size); + + if (new_size <= old_size) { + + /* We already pre-allocated enough space, but before + * we write to it, let's check with fstat() if the + * file got deleted, in order make sure we don't throw + * away the data immediately. Don't check fstat() for + * all writes though, but only once ever 10s. */ + + if (f->last_stat_usec + LAST_STAT_REFRESH_USEC > now(CLOCK_MONOTONIC)) + return 0; + + return journal_file_fstat(f); + } + + /* Allocate more space. */ + + if (f->metrics.max_size > 0 && new_size > f->metrics.max_size) + return -E2BIG; + + /* Refuse to go over 4G in compact mode so offsets can be stored in 32-bit. */ + if (JOURNAL_HEADER_COMPACT(f->header) && new_size > UINT32_MAX) + return -E2BIG; + + if (new_size > f->metrics.min_size && f->metrics.keep_free > 0) { + struct statvfs svfs; + + if (fstatvfs(f->fd, &svfs) >= 0) { + uint64_t available; + + available = LESS_BY((uint64_t) svfs.f_bfree * (uint64_t) svfs.f_bsize, f->metrics.keep_free); + + if (new_size - old_size > available) + return -E2BIG; + } + } + + /* Increase by larger blocks at once */ + new_size = DIV_ROUND_UP(new_size, FILE_SIZE_INCREASE) * FILE_SIZE_INCREASE; + if (f->metrics.max_size > 0 && new_size > f->metrics.max_size) + new_size = f->metrics.max_size; + + /* Note that the glibc fallocate() fallback is very + inefficient, hence we try to minimize the allocation area + as we can. */ + r = posix_fallocate_loop(f->fd, old_size, new_size - old_size); + if (r < 0) + return r; + + f->header->arena_size = htole64(new_size - old_header_size); + + return journal_file_fstat(f); +} + +static unsigned type_to_context(ObjectType type) { + /* One context for each type, plus one catch-all for the rest */ + assert_cc(_OBJECT_TYPE_MAX <= MMAP_CACHE_MAX_CONTEXTS); + assert_cc(CONTEXT_HEADER < MMAP_CACHE_MAX_CONTEXTS); + return type > OBJECT_UNUSED && type < _OBJECT_TYPE_MAX ? type : 0; +} + +static int journal_file_move_to( + JournalFile *f, + ObjectType type, + bool keep_always, + uint64_t offset, + uint64_t size, + void **ret) { + + int r; + + assert(f); + assert(ret); + + /* This function may clear, overwrite, or alter previously cached entries. After this function has + * been called, all objects except for one obtained by this function are invalidated and must be + * re-read before use. */ + + if (size <= 0) + return -EINVAL; + + if (size > UINT64_MAX - offset) + return -EBADMSG; + + /* Avoid SIGBUS on invalid accesses */ + if (offset + size > (uint64_t) f->last_stat.st_size) { + /* Hmm, out of range? Let's refresh the fstat() data + * first, before we trust that check. */ + + r = journal_file_fstat(f); + if (r < 0) + return r; + + if (offset + size > (uint64_t) f->last_stat.st_size) + return -EADDRNOTAVAIL; + } + + return mmap_cache_fd_get(f->cache_fd, type_to_context(type), keep_always, offset, size, &f->last_stat, ret); +} + +static uint64_t minimum_header_size(JournalFile *f, Object *o) { + + static const uint64_t table[] = { + [OBJECT_DATA] = sizeof(DataObject), + [OBJECT_FIELD] = sizeof(FieldObject), + [OBJECT_ENTRY] = sizeof(EntryObject), + [OBJECT_DATA_HASH_TABLE] = sizeof(HashTableObject), + [OBJECT_FIELD_HASH_TABLE] = sizeof(HashTableObject), + [OBJECT_ENTRY_ARRAY] = sizeof(EntryArrayObject), + [OBJECT_TAG] = sizeof(TagObject), + }; + + assert(f); + assert(o); + + if (o->object.type == OBJECT_DATA) + return journal_file_data_payload_offset(f); + + if (o->object.type >= ELEMENTSOF(table) || table[o->object.type] <= 0) + return sizeof(ObjectHeader); + + return table[o->object.type]; +} + +static int check_object_header(JournalFile *f, Object *o, ObjectType type, uint64_t offset) { + uint64_t s; + + assert(f); + assert(o); + + s = le64toh(READ_NOW(o->object.size)); + if (s == 0) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to move to uninitialized object: %" PRIu64, + offset); + + if (s < sizeof(ObjectHeader)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to move to overly short object: %" PRIu64, + offset); + + if (o->object.type <= OBJECT_UNUSED) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to move to object with invalid type: %" PRIu64, + offset); + + if (type > OBJECT_UNUSED && o->object.type != type) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to move to object of unexpected type: %" PRIu64, + offset); + + if (s < minimum_header_size(f, o)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to move to truncated object: %" PRIu64, + offset); + + return 0; +} + +/* Lightweight object checks. We want this to be fast, so that we won't + * slowdown every journal_file_move_to_object() call too much. */ +static int check_object(JournalFile *f, Object *o, uint64_t offset) { + assert(f); + assert(o); + + switch (o->object.type) { + + case OBJECT_DATA: + if ((le64toh(o->data.entry_offset) == 0) ^ (le64toh(o->data.n_entries) == 0)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Bad n_entries: %" PRIu64 ": %" PRIu64, + le64toh(o->data.n_entries), + offset); + + if (le64toh(o->object.size) <= journal_file_data_payload_offset(f)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Bad object size (<= %zu): %" PRIu64 ": %" PRIu64, + journal_file_data_payload_offset(f), + le64toh(o->object.size), + offset); + + if (!VALID64(le64toh(o->data.next_hash_offset)) || + !VALID64(le64toh(o->data.next_field_offset)) || + !VALID64(le64toh(o->data.entry_offset)) || + !VALID64(le64toh(o->data.entry_array_offset))) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid offset, next_hash_offset=" OFSfmt ", next_field_offset=" OFSfmt ", entry_offset=" OFSfmt ", entry_array_offset=" OFSfmt ": %" PRIu64, + le64toh(o->data.next_hash_offset), + le64toh(o->data.next_field_offset), + le64toh(o->data.entry_offset), + le64toh(o->data.entry_array_offset), + offset); + + break; + + case OBJECT_FIELD: + if (le64toh(o->object.size) <= offsetof(Object, field.payload)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Bad field size (<= %zu): %" PRIu64 ": %" PRIu64, + offsetof(Object, field.payload), + le64toh(o->object.size), + offset); + + if (!VALID64(le64toh(o->field.next_hash_offset)) || + !VALID64(le64toh(o->field.head_data_offset))) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid offset, next_hash_offset=" OFSfmt ", head_data_offset=" OFSfmt ": %" PRIu64, + le64toh(o->field.next_hash_offset), + le64toh(o->field.head_data_offset), + offset); + break; + + case OBJECT_ENTRY: { + uint64_t sz; + + sz = le64toh(READ_NOW(o->object.size)); + if (sz < offsetof(Object, entry.items) || + (sz - offsetof(Object, entry.items)) % journal_file_entry_item_size(f) != 0) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Bad entry size (<= %zu): %" PRIu64 ": %" PRIu64, + offsetof(Object, entry.items), + sz, + offset); + + if ((sz - offsetof(Object, entry.items)) / journal_file_entry_item_size(f) <= 0) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid number items in entry: %" PRIu64 ": %" PRIu64, + (sz - offsetof(Object, entry.items)) / journal_file_entry_item_size(f), + offset); + + if (le64toh(o->entry.seqnum) <= 0) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid entry seqnum: %" PRIx64 ": %" PRIu64, + le64toh(o->entry.seqnum), + offset); + + if (!VALID_REALTIME(le64toh(o->entry.realtime))) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid entry realtime timestamp: %" PRIu64 ": %" PRIu64, + le64toh(o->entry.realtime), + offset); + + if (!VALID_MONOTONIC(le64toh(o->entry.monotonic))) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid entry monotonic timestamp: %" PRIu64 ": %" PRIu64, + le64toh(o->entry.monotonic), + offset); + + break; + } + + case OBJECT_DATA_HASH_TABLE: + case OBJECT_FIELD_HASH_TABLE: { + uint64_t sz; + + sz = le64toh(READ_NOW(o->object.size)); + if (sz < offsetof(Object, hash_table.items) || + (sz - offsetof(Object, hash_table.items)) % sizeof(HashItem) != 0 || + (sz - offsetof(Object, hash_table.items)) / sizeof(HashItem) <= 0) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid %s hash table size: %" PRIu64 ": %" PRIu64, + o->object.type == OBJECT_DATA_HASH_TABLE ? "data" : "field", + sz, + offset); + + break; + } + + case OBJECT_ENTRY_ARRAY: { + uint64_t sz, next; + + sz = le64toh(READ_NOW(o->object.size)); + if (sz < offsetof(Object, entry_array.items) || + (sz - offsetof(Object, entry_array.items)) % journal_file_entry_array_item_size(f) != 0 || + (sz - offsetof(Object, entry_array.items)) / journal_file_entry_array_item_size(f) <= 0) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid object entry array size: %" PRIu64 ": %" PRIu64, + sz, + offset); + /* Here, we request that the offset of each entry array object is in strictly increasing order. */ + next = le64toh(o->entry_array.next_entry_array_offset); + if (!VALID64(next) || (next > 0 && next <= offset)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid object entry array next_entry_array_offset: %" PRIu64 ": %" PRIu64, + next, + offset); + + break; + } + + case OBJECT_TAG: + if (le64toh(o->object.size) != sizeof(TagObject)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid object tag size: %" PRIu64 ": %" PRIu64, + le64toh(o->object.size), + offset); + + if (!VALID_EPOCH(le64toh(o->tag.epoch))) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid object tag epoch: %" PRIu64 ": %" PRIu64, + le64toh(o->tag.epoch), offset); + + break; + } + + return 0; +} + +int journal_file_move_to_object(JournalFile *f, ObjectType type, uint64_t offset, Object **ret) { + int r; + Object *o; + + assert(f); + + /* Even if this function fails, it may clear, overwrite, or alter previously cached entries. After + * this function has been called, all objects except for one obtained by this function are + * invalidated and must be re-read before use.. */ + + /* Objects may only be located at multiple of 64 bit */ + if (!VALID64(offset)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to move to object at non-64bit boundary: %" PRIu64, + offset); + + /* Object may not be located in the file header */ + if (offset < le64toh(f->header->header_size)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to move to object located in file header: %" PRIu64, + offset); + + r = journal_file_move_to(f, type, false, offset, sizeof(ObjectHeader), (void**) &o); + if (r < 0) + return r; + + r = check_object_header(f, o, type, offset); + if (r < 0) + return r; + + r = journal_file_move_to(f, type, false, offset, le64toh(READ_NOW(o->object.size)), (void**) &o); + if (r < 0) + return r; + + r = check_object_header(f, o, type, offset); + if (r < 0) + return r; + + r = check_object(f, o, offset); + if (r < 0) + return r; + + if (ret) + *ret = o; + + return 0; +} + +int journal_file_read_object_header(JournalFile *f, ObjectType type, uint64_t offset, Object *ret) { + ssize_t n; + Object o; + int r; + + assert(f); + + /* Objects may only be located at multiple of 64 bit */ + if (!VALID64(offset)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to read object at non-64bit boundary: %" PRIu64, + offset); + + /* Object may not be located in the file header */ + if (offset < le64toh(f->header->header_size)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Attempt to read object located in file header: %" PRIu64, + offset); + + /* This will likely read too much data but it avoids having to call pread() twice. */ + n = pread(f->fd, &o, sizeof(o), offset); + if (n < 0) + return log_debug_errno(errno, "Failed to read journal file at offset: %" PRIu64, + offset); + + if ((size_t) n < sizeof(o.object)) + return log_debug_errno(SYNTHETIC_ERRNO(EIO), + "Failed to read short object at offset: %" PRIu64, + offset); + + r = check_object_header(f, &o, type, offset); + if (r < 0) + return r; + + if ((size_t) n < minimum_header_size(f, &o)) + return log_debug_errno(SYNTHETIC_ERRNO(EIO), + "Short read while reading object: %" PRIu64, + offset); + + r = check_object(f, &o, offset); + if (r < 0) + return r; + + if (ret) + *ret = o; + + return 0; +} + +static uint64_t journal_file_entry_seqnum( + JournalFile *f, + uint64_t *seqnum) { + + uint64_t ret; + + assert(f); + assert(f->header); + + /* Picks a new sequence number for the entry we are about to add and returns it. */ + + ret = le64toh(f->header->tail_entry_seqnum) + 1; + + if (seqnum) { + /* If an external seqnum counter was passed, we update both the local and the external one, + * and set it to the maximum of both */ + + if (*seqnum + 1 > ret) + ret = *seqnum + 1; + + *seqnum = ret; + } + + f->header->tail_entry_seqnum = htole64(ret); + + if (f->header->head_entry_seqnum == 0) + f->header->head_entry_seqnum = htole64(ret); + + return ret; +} + +int journal_file_append_object( + JournalFile *f, + ObjectType type, + uint64_t size, + Object **ret_object, + uint64_t *ret_offset) { + + int r; + uint64_t p; + Object *o; + + assert(f); + assert(f->header); + assert(type > OBJECT_UNUSED && type < _OBJECT_TYPE_MAX); + assert(size >= sizeof(ObjectHeader)); + + r = journal_file_set_online(f); + if (r < 0) + return r; + + r = journal_file_tail_end_by_mmap(f, &p); + if (r < 0) + return r; + + r = journal_file_allocate(f, p, size); + if (r < 0) + return r; + + r = journal_file_move_to(f, type, false, p, size, (void**) &o); + if (r < 0) + return r; + + o->object = (ObjectHeader) { + .type = type, + .size = htole64(size), + }; + + f->header->tail_object_offset = htole64(p); + f->header->n_objects = htole64(le64toh(f->header->n_objects) + 1); + + if (ret_object) + *ret_object = o; + + if (ret_offset) + *ret_offset = p; + + return 0; +} + +static int journal_file_setup_data_hash_table(JournalFile *f) { + uint64_t s, p; + Object *o; + int r; + + assert(f); + assert(f->header); + + /* We estimate that we need 1 hash table entry per 768 bytes + of journal file and we want to make sure we never get + beyond 75% fill level. Calculate the hash table size for + the maximum file size based on these metrics. */ + + s = (f->metrics.max_size * 4 / 768 / 3) * sizeof(HashItem); + if (s < DEFAULT_DATA_HASH_TABLE_SIZE) + s = DEFAULT_DATA_HASH_TABLE_SIZE; + + log_debug("Reserving %"PRIu64" entries in data hash table.", s / sizeof(HashItem)); + + r = journal_file_append_object(f, + OBJECT_DATA_HASH_TABLE, + offsetof(Object, hash_table.items) + s, + &o, &p); + if (r < 0) + return r; + + memzero(o->hash_table.items, s); + + f->header->data_hash_table_offset = htole64(p + offsetof(Object, hash_table.items)); + f->header->data_hash_table_size = htole64(s); + + return 0; +} + +static int journal_file_setup_field_hash_table(JournalFile *f) { + uint64_t s, p; + Object *o; + int r; + + assert(f); + assert(f->header); + + /* We use a fixed size hash table for the fields as this + * number should grow very slowly only */ + + s = DEFAULT_FIELD_HASH_TABLE_SIZE; + log_debug("Reserving %"PRIu64" entries in field hash table.", s / sizeof(HashItem)); + + r = journal_file_append_object(f, + OBJECT_FIELD_HASH_TABLE, + offsetof(Object, hash_table.items) + s, + &o, &p); + if (r < 0) + return r; + + memzero(o->hash_table.items, s); + + f->header->field_hash_table_offset = htole64(p + offsetof(Object, hash_table.items)); + f->header->field_hash_table_size = htole64(s); + + return 0; +} + +int journal_file_map_data_hash_table(JournalFile *f) { + uint64_t s, p; + void *t; + int r; + + assert(f); + assert(f->header); + + if (f->data_hash_table) + return 0; + + p = le64toh(f->header->data_hash_table_offset); + s = le64toh(f->header->data_hash_table_size); + + r = journal_file_move_to(f, + OBJECT_DATA_HASH_TABLE, + true, + p, s, + &t); + if (r < 0) + return r; + + f->data_hash_table = t; + return 0; +} + +int journal_file_map_field_hash_table(JournalFile *f) { + uint64_t s, p; + void *t; + int r; + + assert(f); + assert(f->header); + + if (f->field_hash_table) + return 0; + + p = le64toh(f->header->field_hash_table_offset); + s = le64toh(f->header->field_hash_table_size); + + r = journal_file_move_to(f, + OBJECT_FIELD_HASH_TABLE, + true, + p, s, + &t); + if (r < 0) + return r; + + f->field_hash_table = t; + return 0; +} + +static int journal_file_link_field( + JournalFile *f, + Object *o, + uint64_t offset, + uint64_t hash) { + + uint64_t p, h, m; + int r; + + assert(f); + assert(f->header); + assert(f->field_hash_table); + assert(o); + assert(offset > 0); + + if (o->object.type != OBJECT_FIELD) + return -EINVAL; + + m = le64toh(READ_NOW(f->header->field_hash_table_size)) / sizeof(HashItem); + if (m <= 0) + return -EBADMSG; + + /* This might alter the window we are looking at */ + o->field.next_hash_offset = o->field.head_data_offset = 0; + + h = hash % m; + p = le64toh(f->field_hash_table[h].tail_hash_offset); + if (p == 0) + f->field_hash_table[h].head_hash_offset = htole64(offset); + else { + r = journal_file_move_to_object(f, OBJECT_FIELD, p, &o); + if (r < 0) + return r; + + o->field.next_hash_offset = htole64(offset); + } + + f->field_hash_table[h].tail_hash_offset = htole64(offset); + + if (JOURNAL_HEADER_CONTAINS(f->header, n_fields)) + f->header->n_fields = htole64(le64toh(f->header->n_fields) + 1); + + return 0; +} + +static int journal_file_link_data( + JournalFile *f, + Object *o, + uint64_t offset, + uint64_t hash) { + + uint64_t p, h, m; + int r; + + assert(f); + assert(f->header); + assert(f->data_hash_table); + assert(o); + assert(offset > 0); + + if (o->object.type != OBJECT_DATA) + return -EINVAL; + + m = le64toh(READ_NOW(f->header->data_hash_table_size)) / sizeof(HashItem); + if (m <= 0) + return -EBADMSG; + + /* This might alter the window we are looking at */ + o->data.next_hash_offset = o->data.next_field_offset = 0; + o->data.entry_offset = o->data.entry_array_offset = 0; + o->data.n_entries = 0; + + h = hash % m; + p = le64toh(f->data_hash_table[h].tail_hash_offset); + if (p == 0) + /* Only entry in the hash table is easy */ + f->data_hash_table[h].head_hash_offset = htole64(offset); + else { + /* Move back to the previous data object, to patch in + * pointer */ + + r = journal_file_move_to_object(f, OBJECT_DATA, p, &o); + if (r < 0) + return r; + + o->data.next_hash_offset = htole64(offset); + } + + f->data_hash_table[h].tail_hash_offset = htole64(offset); + + if (JOURNAL_HEADER_CONTAINS(f->header, n_data)) + f->header->n_data = htole64(le64toh(f->header->n_data) + 1); + + return 0; +} + +static int get_next_hash_offset( + JournalFile *f, + uint64_t *p, + le64_t *next_hash_offset, + uint64_t *depth, + le64_t *header_max_depth) { + + uint64_t nextp; + + assert(f); + assert(p); + assert(next_hash_offset); + assert(depth); + + nextp = le64toh(READ_NOW(*next_hash_offset)); + if (nextp > 0) { + if (nextp <= *p) /* Refuse going in loops */ + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Detected hash item loop in %s, refusing.", f->path); + + (*depth)++; + + /* If the depth of this hash chain is larger than all others we have seen so far, record it */ + if (header_max_depth && journal_file_writable(f)) + *header_max_depth = htole64(MAX(*depth, le64toh(*header_max_depth))); + } + + *p = nextp; + return 0; +} + +int journal_file_find_field_object_with_hash( + JournalFile *f, + const void *field, + uint64_t size, + uint64_t hash, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t p, osize, h, m, depth = 0; + int r; + + assert(f); + assert(f->header); + assert(field); + assert(size > 0); + + /* If the field hash table is empty, we can't find anything */ + if (le64toh(f->header->field_hash_table_size) <= 0) + return 0; + + /* Map the field hash table, if it isn't mapped yet. */ + r = journal_file_map_field_hash_table(f); + if (r < 0) + return r; + + osize = offsetof(Object, field.payload) + size; + + m = le64toh(READ_NOW(f->header->field_hash_table_size)) / sizeof(HashItem); + if (m <= 0) + return -EBADMSG; + + h = hash % m; + p = le64toh(f->field_hash_table[h].head_hash_offset); + while (p > 0) { + Object *o; + + r = journal_file_move_to_object(f, OBJECT_FIELD, p, &o); + if (r < 0) + return r; + + if (le64toh(o->field.hash) == hash && + le64toh(o->object.size) == osize && + memcmp(o->field.payload, field, size) == 0) { + + if (ret_object) + *ret_object = o; + if (ret_offset) + *ret_offset = p; + + return 1; + } + + r = get_next_hash_offset( + f, + &p, + &o->field.next_hash_offset, + &depth, + JOURNAL_HEADER_CONTAINS(f->header, field_hash_chain_depth) ? &f->header->field_hash_chain_depth : NULL); + if (r < 0) + return r; + } + + return 0; +} + +uint64_t journal_file_hash_data( + JournalFile *f, + const void *data, + size_t sz) { + + assert(f); + assert(f->header); + assert(data || sz == 0); + + /* We try to unify our codebase on siphash, hence new-styled journal files utilizing the keyed hash + * function use siphash. Old journal files use the Jenkins hash. */ + + if (JOURNAL_HEADER_KEYED_HASH(f->header)) + return siphash24(data, sz, f->header->file_id.bytes); + + return jenkins_hash64(data, sz); +} + +int journal_file_find_field_object( + JournalFile *f, + const void *field, + uint64_t size, + Object **ret_object, + uint64_t *ret_offset) { + + assert(f); + assert(field); + assert(size > 0); + + return journal_file_find_field_object_with_hash( + f, + field, size, + journal_file_hash_data(f, field, size), + ret_object, ret_offset); +} + +int journal_file_find_data_object_with_hash( + JournalFile *f, + const void *data, + uint64_t size, + uint64_t hash, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t p, h, m, depth = 0; + int r; + + assert(f); + assert(f->header); + assert(data || size == 0); + + /* If there's no data hash table, then there's no entry. */ + if (le64toh(f->header->data_hash_table_size) <= 0) + return 0; + + /* Map the data hash table, if it isn't mapped yet. */ + r = journal_file_map_data_hash_table(f); + if (r < 0) + return r; + + m = le64toh(READ_NOW(f->header->data_hash_table_size)) / sizeof(HashItem); + if (m <= 0) + return -EBADMSG; + + h = hash % m; + p = le64toh(f->data_hash_table[h].head_hash_offset); + + while (p > 0) { + Object *o; + void *d; + size_t rsize; + + r = journal_file_move_to_object(f, OBJECT_DATA, p, &o); + if (r < 0) + return r; + + if (le64toh(o->data.hash) != hash) + goto next; + + r = journal_file_data_payload(f, o, p, NULL, 0, 0, &d, &rsize); + if (r < 0) + return r; + assert(r > 0); /* journal_file_data_payload() always returns > 0 if no field is provided. */ + + if (memcmp_nn(data, size, d, rsize) == 0) { + if (ret_object) + *ret_object = o; + + if (ret_offset) + *ret_offset = p; + + return 1; + } + + next: + r = get_next_hash_offset( + f, + &p, + &o->data.next_hash_offset, + &depth, + JOURNAL_HEADER_CONTAINS(f->header, data_hash_chain_depth) ? &f->header->data_hash_chain_depth : NULL); + if (r < 0) + return r; + } + + return 0; +} + +int journal_file_find_data_object( + JournalFile *f, + const void *data, + uint64_t size, + Object **ret_object, + uint64_t *ret_offset) { + + assert(f); + assert(data || size == 0); + + return journal_file_find_data_object_with_hash( + f, + data, size, + journal_file_hash_data(f, data, size), + ret_object, ret_offset); +} + +bool journal_field_valid(const char *p, size_t l, bool allow_protected) { + /* We kinda enforce POSIX syntax recommendations for + environment variables here, but make a couple of additional + requirements. + + http://pubs.opengroup.org/onlinepubs/000095399/basedefs/xbd_chap08.html */ + + assert(p); + + if (l == SIZE_MAX) + l = strlen(p); + + /* No empty field names */ + if (l <= 0) + return false; + + /* Don't allow names longer than 64 chars */ + if (l > 64) + return false; + + /* Variables starting with an underscore are protected */ + if (!allow_protected && p[0] == '_') + return false; + + /* Don't allow digits as first character */ + if (ascii_isdigit(p[0])) + return false; + + /* Only allow A-Z0-9 and '_' */ + for (const char *a = p; a < p + l; a++) + if ((*a < 'A' || *a > 'Z') && + !ascii_isdigit(*a) && + *a != '_') + return false; + + return true; +} + +static int journal_file_append_field( + JournalFile *f, + const void *field, + uint64_t size, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t hash, p; + uint64_t osize; + Object *o; + int r; + + assert(f); + assert(field); + assert(size > 0); + + if (!journal_field_valid(field, size, true)) + return -EBADMSG; + + hash = journal_file_hash_data(f, field, size); + + r = journal_file_find_field_object_with_hash(f, field, size, hash, ret_object, ret_offset); + if (r < 0) + return r; + if (r > 0) + return 0; + + osize = offsetof(Object, field.payload) + size; + r = journal_file_append_object(f, OBJECT_FIELD, osize, &o, &p); + if (r < 0) + return r; + + o->field.hash = htole64(hash); + memcpy(o->field.payload, field, size); + + r = journal_file_link_field(f, o, p, hash); + if (r < 0) + return r; + + /* The linking might have altered the window, so let's only pass the offset to hmac which will + * move to the object again if needed. */ + +#if HAVE_GCRYPT + r = journal_file_hmac_put_object(f, OBJECT_FIELD, NULL, p); + if (r < 0) + return r; +#endif + + if (ret_object) { + r = journal_file_move_to_object(f, OBJECT_FIELD, p, ret_object); + if (r < 0) + return r; + } + + if (ret_offset) + *ret_offset = p; + + return 0; +} + +static Compression maybe_compress_payload(JournalFile *f, uint8_t *dst, const uint8_t *src, uint64_t size, size_t *rsize) { + Compression compression = COMPRESSION_NONE; + + assert(f); + assert(f->header); + +#if HAVE_COMPRESSION + if (JOURNAL_FILE_COMPRESS(f) && size >= f->compress_threshold_bytes) { + compression = compress_blob(src, size, dst, size - 1, rsize); + if (compression > 0) + log_debug("Compressed data object %"PRIu64" -> %zu using %s", + size, *rsize, compression_to_string(compression)); + else + /* Compression didn't work, we don't really care why, let's continue without compression */ + compression = COMPRESSION_NONE; + } +#endif + + return compression; +} + +static int journal_file_append_data( + JournalFile *f, + const void *data, + uint64_t size, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t hash, p, osize; + Object *o, *fo; + size_t rsize = 0; + Compression c; + const void *eq; + int r; + + assert(f); + + if (!data || size == 0) + return -EINVAL; + + hash = journal_file_hash_data(f, data, size); + + r = journal_file_find_data_object_with_hash(f, data, size, hash, ret_object, ret_offset); + if (r < 0) + return r; + if (r > 0) + return 0; + + eq = memchr(data, '=', size); + if (!eq) + return -EINVAL; + + osize = journal_file_data_payload_offset(f) + size; + r = journal_file_append_object(f, OBJECT_DATA, osize, &o, &p); + if (r < 0) + return r; + + o->data.hash = htole64(hash); + + c = maybe_compress_payload(f, journal_file_data_payload_field(f, o), data, size, &rsize); + + if (c != COMPRESSION_NONE) { + o->object.size = htole64(journal_file_data_payload_offset(f) + rsize); + o->object.flags |= COMPRESSION_TO_OBJECT_FLAG(c); + } else + memcpy_safe(journal_file_data_payload_field(f, o), data, size); + + r = journal_file_link_data(f, o, p, hash); + if (r < 0) + return r; + + /* The linking might have altered the window, so let's refresh our pointer. */ + r = journal_file_move_to_object(f, OBJECT_DATA, p, &o); + if (r < 0) + return r; + +#if HAVE_GCRYPT + r = journal_file_hmac_put_object(f, OBJECT_DATA, o, p); + if (r < 0) + return r; +#endif + + /* Create field object ... */ + r = journal_file_append_field(f, data, (uint8_t*) eq - (uint8_t*) data, &fo, NULL); + if (r < 0) + return r; + + /* ... and link it in. */ + o->data.next_field_offset = fo->field.head_data_offset; + fo->field.head_data_offset = le64toh(p); + + if (ret_object) + *ret_object = o; + + if (ret_offset) + *ret_offset = p; + + return 0; +} + +static int maybe_decompress_payload( + JournalFile *f, + uint8_t *payload, + uint64_t size, + Compression compression, + const char *field, + size_t field_length, + size_t data_threshold, + void **ret_data, + size_t *ret_size) { + + assert(f); + + /* We can't read objects larger than 4G on a 32bit machine */ + if ((uint64_t) (size_t) size != size) + return -E2BIG; + + if (compression != COMPRESSION_NONE) { +#if HAVE_COMPRESSION + size_t rsize; + int r; + + if (field) { + r = decompress_startswith(compression, payload, size, &f->compress_buffer, field, + field_length, '='); + if (r < 0) + return log_debug_errno(r, + "Cannot decompress %s object of length %" PRIu64 ": %m", + compression_to_string(compression), + size); + if (r == 0) { + if (ret_data) + *ret_data = NULL; + if (ret_size) + *ret_size = 0; + return 0; + } + } + + r = decompress_blob(compression, payload, size, &f->compress_buffer, &rsize, 0); + if (r < 0) + return r; + + if (ret_data) + *ret_data = f->compress_buffer; + if (ret_size) + *ret_size = rsize; +#else + return -EPROTONOSUPPORT; +#endif + } else { + if (field && (size < field_length + 1 || memcmp(payload, field, field_length) != 0 || payload[field_length] != '=')) { + if (ret_data) + *ret_data = NULL; + if (ret_size) + *ret_size = 0; + return 0; + } + + if (ret_data) + *ret_data = payload; + if (ret_size) + *ret_size = (size_t) size; + } + + return 1; +} + +int journal_file_data_payload( + JournalFile *f, + Object *o, + uint64_t offset, + const char *field, + size_t field_length, + size_t data_threshold, + void **ret_data, + size_t *ret_size) { + + uint64_t size; + Compression c; + int r; + + assert(f); + assert(!field == (field_length == 0)); /* These must be specified together. */ + + if (!o) { + r = journal_file_move_to_object(f, OBJECT_DATA, offset, &o); + if (r < 0) + return r; + } + + size = le64toh(READ_NOW(o->object.size)); + if (size < journal_file_data_payload_offset(f)) + return -EBADMSG; + + size -= journal_file_data_payload_offset(f); + + c = COMPRESSION_FROM_OBJECT(o); + if (c < 0) + return -EPROTONOSUPPORT; + + return maybe_decompress_payload(f, journal_file_data_payload_field(f, o), size, c, field, + field_length, data_threshold, ret_data, ret_size); +} + +uint64_t journal_file_entry_n_items(JournalFile *f, Object *o) { + uint64_t sz; + + assert(f); + assert(o); + + if (o->object.type != OBJECT_ENTRY) + return 0; + + sz = le64toh(READ_NOW(o->object.size)); + if (sz < offsetof(Object, entry.items)) + return 0; + + return (sz - offsetof(Object, entry.items)) / journal_file_entry_item_size(f); +} + +uint64_t journal_file_entry_array_n_items(JournalFile *f, Object *o) { + uint64_t sz; + + assert(f); + assert(o); + + if (o->object.type != OBJECT_ENTRY_ARRAY) + return 0; + + sz = le64toh(READ_NOW(o->object.size)); + if (sz < offsetof(Object, entry_array.items)) + return 0; + + return (sz - offsetof(Object, entry_array.items)) / journal_file_entry_array_item_size(f); +} + +uint64_t journal_file_hash_table_n_items(Object *o) { + uint64_t sz; + + assert(o); + + if (!IN_SET(o->object.type, OBJECT_DATA_HASH_TABLE, OBJECT_FIELD_HASH_TABLE)) + return 0; + + sz = le64toh(READ_NOW(o->object.size)); + if (sz < offsetof(Object, hash_table.items)) + return 0; + + return (sz - offsetof(Object, hash_table.items)) / sizeof(HashItem); +} + +static void write_entry_array_item(JournalFile *f, Object *o, uint64_t i, uint64_t p) { + assert(f); + assert(o); + + if (JOURNAL_HEADER_COMPACT(f->header)) { + assert(p <= UINT32_MAX); + o->entry_array.items.compact[i] = htole32(p); + } else + o->entry_array.items.regular[i] = htole64(p); +} + +static int link_entry_into_array( + JournalFile *f, + le64_t *first, + le64_t *idx, + le32_t *tail, + le32_t *tidx, + uint64_t p) { + + uint64_t n = 0, ap = 0, q, i, a, hidx; + Object *o; + int r; + + assert(f); + assert(f->header); + assert(first); + assert(idx); + assert(p > 0); + + a = tail ? le32toh(*tail) : le64toh(*first); + hidx = le64toh(READ_NOW(*idx)); + i = tidx ? le32toh(READ_NOW(*tidx)) : hidx; + + while (a > 0) { + r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o); + if (r < 0) + return r; + + n = journal_file_entry_array_n_items(f, o); + if (i < n) { + write_entry_array_item(f, o, i, p); + *idx = htole64(hidx + 1); + if (tidx) + *tidx = htole32(le32toh(*tidx) + 1); + return 0; + } + + i -= n; + ap = a; + a = le64toh(o->entry_array.next_entry_array_offset); + } + + if (hidx > n) + n = (hidx+1) * 2; + else + n = n * 2; + + if (n < 4) + n = 4; + + r = journal_file_append_object(f, OBJECT_ENTRY_ARRAY, + offsetof(Object, entry_array.items) + n * journal_file_entry_array_item_size(f), + &o, &q); + if (r < 0) + return r; + +#if HAVE_GCRYPT + r = journal_file_hmac_put_object(f, OBJECT_ENTRY_ARRAY, o, q); + if (r < 0) + return r; +#endif + + write_entry_array_item(f, o, i, p); + + if (ap == 0) + *first = htole64(q); + else { + r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, ap, &o); + if (r < 0) + return r; + + o->entry_array.next_entry_array_offset = htole64(q); + } + + if (tail) + *tail = htole32(q); + + if (JOURNAL_HEADER_CONTAINS(f->header, n_entry_arrays)) + f->header->n_entry_arrays = htole64(le64toh(f->header->n_entry_arrays) + 1); + + *idx = htole64(hidx + 1); + if (tidx) + *tidx = htole32(1); + + return 0; +} + +static int link_entry_into_array_plus_one( + JournalFile *f, + le64_t *extra, + le64_t *first, + le64_t *idx, + le32_t *tail, + le32_t *tidx, + uint64_t p) { + + uint64_t hidx; + int r; + + assert(f); + assert(extra); + assert(first); + assert(idx); + assert(p > 0); + + hidx = le64toh(READ_NOW(*idx)); + if (hidx == UINT64_MAX) + return -EBADMSG; + if (hidx == 0) + *extra = htole64(p); + else { + le64_t i; + + i = htole64(hidx - 1); + r = link_entry_into_array(f, first, &i, tail, tidx, p); + if (r < 0) + return r; + } + + *idx = htole64(hidx + 1); + return 0; +} + +static int journal_file_link_entry_item(JournalFile *f, uint64_t offset, uint64_t p) { + Object *o; + int r; + + assert(f); + assert(offset > 0); + + r = journal_file_move_to_object(f, OBJECT_DATA, p, &o); + if (r < 0) + return r; + + return link_entry_into_array_plus_one(f, + &o->data.entry_offset, + &o->data.entry_array_offset, + &o->data.n_entries, + JOURNAL_HEADER_COMPACT(f->header) ? &o->data.compact.tail_entry_array_offset : NULL, + JOURNAL_HEADER_COMPACT(f->header) ? &o->data.compact.tail_entry_array_n_entries : NULL, + offset); +} + +static int journal_file_link_entry( + JournalFile *f, + Object *o, + uint64_t offset, + const EntryItem items[], + size_t n_items) { + + int r; + + assert(f); + assert(f->header); + assert(o); + assert(offset > 0); + + if (o->object.type != OBJECT_ENTRY) + return -EINVAL; + + __atomic_thread_fence(__ATOMIC_SEQ_CST); + + /* Link up the entry itself */ + r = link_entry_into_array(f, + &f->header->entry_array_offset, + &f->header->n_entries, + JOURNAL_HEADER_CONTAINS(f->header, tail_entry_array_offset) ? &f->header->tail_entry_array_offset : NULL, + JOURNAL_HEADER_CONTAINS(f->header, tail_entry_array_n_entries) ? &f->header->tail_entry_array_n_entries : NULL, + offset); + if (r < 0) + return r; + + /* log_debug("=> %s seqnr=%"PRIu64" n_entries=%"PRIu64, f->path, o->entry.seqnum, f->header->n_entries); */ + + if (f->header->head_entry_realtime == 0) + f->header->head_entry_realtime = o->entry.realtime; + + f->header->tail_entry_realtime = o->entry.realtime; + f->header->tail_entry_monotonic = o->entry.monotonic; + + /* Link up the items */ + for (uint64_t i = 0; i < n_items; i++) { + int k; + + /* If we fail to link an entry item because we can't allocate a new entry array, don't fail + * immediately but try to link the other entry items since it might still be possible to link + * those if they don't require a new entry array to be allocated. */ + + k = journal_file_link_entry_item(f, offset, items[i].object_offset); + if (k == -E2BIG) + r = k; + else if (k < 0) + return k; + } + + return r; +} + +static void write_entry_item(JournalFile *f, Object *o, uint64_t i, const EntryItem *item) { + assert(f); + assert(o); + assert(item); + + if (JOURNAL_HEADER_COMPACT(f->header)) { + assert(item->object_offset <= UINT32_MAX); + o->entry.items.compact[i].object_offset = htole32(item->object_offset); + } else { + o->entry.items.regular[i].object_offset = htole64(item->object_offset); + o->entry.items.regular[i].hash = htole64(item->hash); + } +} + +static int journal_file_append_entry_internal( + JournalFile *f, + const dual_timestamp *ts, + const sd_id128_t *boot_id, + uint64_t xor_hash, + const EntryItem items[], + size_t n_items, + uint64_t *seqnum, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t np; + uint64_t osize; + Object *o; + int r; + + assert(f); + assert(f->header); + assert(ts); + assert(items || n_items == 0); + + osize = offsetof(Object, entry.items) + (n_items * journal_file_entry_item_size(f)); + + r = journal_file_append_object(f, OBJECT_ENTRY, osize, &o, &np); + if (r < 0) + return r; + + o->entry.seqnum = htole64(journal_file_entry_seqnum(f, seqnum)); + o->entry.realtime = htole64(ts->realtime); + o->entry.monotonic = htole64(ts->monotonic); + o->entry.xor_hash = htole64(xor_hash); + if (boot_id) + f->header->boot_id = *boot_id; + o->entry.boot_id = f->header->boot_id; + + for (size_t i = 0; i < n_items; i++) + write_entry_item(f, o, i, &items[i]); + +#if HAVE_GCRYPT + r = journal_file_hmac_put_object(f, OBJECT_ENTRY, o, np); + if (r < 0) + return r; +#endif + + r = journal_file_link_entry(f, o, np, items, n_items); + if (r < 0) + return r; + + if (ret_object) + *ret_object = o; + + if (ret_offset) + *ret_offset = np; + + return r; +} + +void journal_file_post_change(JournalFile *f) { + assert(f); + + if (f->fd < 0) + return; + + /* inotify() does not receive IN_MODIFY events from file + * accesses done via mmap(). After each access we hence + * trigger IN_MODIFY by truncating the journal file to its + * current size which triggers IN_MODIFY. */ + + __atomic_thread_fence(__ATOMIC_SEQ_CST); + + if (ftruncate(f->fd, f->last_stat.st_size) < 0) + log_debug_errno(errno, "Failed to truncate file to its own size: %m"); +} + +static int post_change_thunk(sd_event_source *timer, uint64_t usec, void *userdata) { + assert(userdata); + + journal_file_post_change(userdata); + + return 1; +} + +static void schedule_post_change(JournalFile *f) { + sd_event *e; + int r; + + assert(f); + assert(f->post_change_timer); + + assert_se(e = sd_event_source_get_event(f->post_change_timer)); + + /* If we are already going down, post the change immediately. */ + if (IN_SET(sd_event_get_state(e), SD_EVENT_EXITING, SD_EVENT_FINISHED)) + goto fail; + + r = sd_event_source_get_enabled(f->post_change_timer, NULL); + if (r < 0) { + log_debug_errno(r, "Failed to get ftruncate timer state: %m"); + goto fail; + } + if (r > 0) + return; + + r = sd_event_source_set_time_relative(f->post_change_timer, f->post_change_timer_period); + if (r < 0) { + log_debug_errno(r, "Failed to set time for scheduling ftruncate: %m"); + goto fail; + } + + r = sd_event_source_set_enabled(f->post_change_timer, SD_EVENT_ONESHOT); + if (r < 0) { + log_debug_errno(r, "Failed to enable scheduled ftruncate: %m"); + goto fail; + } + + return; + +fail: + /* On failure, let's simply post the change immediately. */ + journal_file_post_change(f); +} + +/* Enable coalesced change posting in a timer on the provided sd_event instance */ +int journal_file_enable_post_change_timer(JournalFile *f, sd_event *e, usec_t t) { + _cleanup_(sd_event_source_unrefp) sd_event_source *timer = NULL; + int r; + + assert(f); + assert_return(!f->post_change_timer, -EINVAL); + assert(e); + assert(t); + + /* If we are already going down, we cannot install the timer. + * In such case, the caller needs to call journal_file_post_change() explicitly. */ + if (IN_SET(sd_event_get_state(e), SD_EVENT_EXITING, SD_EVENT_FINISHED)) + return 0; + + r = sd_event_add_time(e, &timer, CLOCK_MONOTONIC, 0, 0, post_change_thunk, f); + if (r < 0) + return r; + + r = sd_event_source_set_enabled(timer, SD_EVENT_OFF); + if (r < 0) + return r; + + f->post_change_timer = TAKE_PTR(timer); + f->post_change_timer_period = t; + + return 1; +} + +static int entry_item_cmp(const EntryItem *a, const EntryItem *b) { + return CMP(ASSERT_PTR(a)->object_offset, ASSERT_PTR(b)->object_offset); +} + +static size_t remove_duplicate_entry_items(EntryItem items[], size_t n) { + size_t j = 1; + + assert(items || n == 0); + + if (n <= 1) + return n; + + for (size_t i = 1; i < n; i++) + if (items[i].object_offset != items[j - 1].object_offset) + items[j++] = items[i]; + + return j; +} + +int journal_file_append_entry( + JournalFile *f, + const dual_timestamp *ts, + const sd_id128_t *boot_id, + const struct iovec iovec[], + unsigned n_iovec, + uint64_t *seqnum, + Object **ret_object, + uint64_t *ret_offset) { + + _cleanup_free_ EntryItem *items_alloc = NULL; + EntryItem *items; + uint64_t xor_hash = 0; + struct dual_timestamp _ts; + int r; + + assert(f); + assert(f->header); + assert(iovec); + assert(n_iovec > 0); + + if (ts) { + if (!VALID_REALTIME(ts->realtime)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid realtime timestamp %" PRIu64 ", refusing entry.", + ts->realtime); + if (!VALID_MONOTONIC(ts->monotonic)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "Invalid monotomic timestamp %" PRIu64 ", refusing entry.", + ts->monotonic); + } else { + dual_timestamp_get(&_ts); + ts = &_ts; + } + +#if HAVE_GCRYPT + r = journal_file_maybe_append_tag(f, ts->realtime); + if (r < 0) + return r; +#endif + + if (n_iovec < ALLOCA_MAX / sizeof(EntryItem) / 2) + items = newa(EntryItem, n_iovec); + else { + items_alloc = new(EntryItem, n_iovec); + if (!items_alloc) + return -ENOMEM; + + items = items_alloc; + } + + for (size_t i = 0; i < n_iovec; i++) { + uint64_t p; + Object *o; + + r = journal_file_append_data(f, iovec[i].iov_base, iovec[i].iov_len, &o, &p); + if (r < 0) + return r; + + /* When calculating the XOR hash field, we need to take special care if the "keyed-hash" + * journal file flag is on. We use the XOR hash field to quickly determine the identity of a + * specific record, and give records with otherwise identical position (i.e. match in seqno, + * timestamp, …) a stable ordering. But for that we can't have it that the hash of the + * objects in each file is different since they are keyed. Hence let's calculate the Jenkins + * hash here for that. This also has the benefit that cursors for old and new journal files + * are completely identical (they include the XOR hash after all). For classic Jenkins-hash + * files things are easier, we can just take the value from the stored record directly. */ + + if (JOURNAL_HEADER_KEYED_HASH(f->header)) + xor_hash ^= jenkins_hash64(iovec[i].iov_base, iovec[i].iov_len); + else + xor_hash ^= le64toh(o->data.hash); + + items[i] = (EntryItem) { + .object_offset = p, + .hash = le64toh(o->data.hash), + }; + } + + /* Order by the position on disk, in order to improve seek + * times for rotating media. */ + typesafe_qsort(items, n_iovec, entry_item_cmp); + n_iovec = remove_duplicate_entry_items(items, n_iovec); + + r = journal_file_append_entry_internal(f, ts, boot_id, xor_hash, items, n_iovec, seqnum, ret_object, ret_offset); + + /* If the memory mapping triggered a SIGBUS then we return an + * IO error and ignore the error code passed down to us, since + * it is very likely just an effect of a nullified replacement + * mapping page */ + + if (mmap_cache_fd_got_sigbus(f->cache_fd)) + r = -EIO; + + if (f->post_change_timer) + schedule_post_change(f); + else + journal_file_post_change(f); + + return r; +} + +typedef struct ChainCacheItem { + uint64_t first; /* the array at the beginning of the chain */ + uint64_t array; /* the cached array */ + uint64_t begin; /* the first item in the cached array */ + uint64_t total; /* the total number of items in all arrays before this one in the chain */ + uint64_t last_index; /* the last index we looked at, to optimize locality when bisecting */ +} ChainCacheItem; + +static void chain_cache_put( + OrderedHashmap *h, + ChainCacheItem *ci, + uint64_t first, + uint64_t array, + uint64_t begin, + uint64_t total, + uint64_t last_index) { + + assert(h); + + if (!ci) { + /* If the chain item to cache for this chain is the + * first one it's not worth caching anything */ + if (array == first) + return; + + if (ordered_hashmap_size(h) >= CHAIN_CACHE_MAX) { + ci = ordered_hashmap_steal_first(h); + assert(ci); + } else { + ci = new(ChainCacheItem, 1); + if (!ci) + return; + } + + ci->first = first; + + if (ordered_hashmap_put(h, &ci->first, ci) < 0) { + free(ci); + return; + } + } else + assert(ci->first == first); + + ci->array = array; + ci->begin = begin; + ci->total = total; + ci->last_index = last_index; +} + +static int bump_array_index(uint64_t *i, direction_t direction, uint64_t n) { + assert(i); + + /* Increase or decrease the specified index, in the right direction. */ + + if (direction == DIRECTION_DOWN) { + if (*i >= n - 1) + return 0; + + (*i)++; + } else { + if (*i <= 0) + return 0; + + (*i)--; + } + + return 1; +} + +static int bump_entry_array( + JournalFile *f, + Object *o, + uint64_t offset, + uint64_t first, + direction_t direction, + uint64_t *ret) { + + uint64_t p, q = 0; + int r; + + assert(f); + assert(offset); + assert(ret); + + if (direction == DIRECTION_DOWN) { + assert(o); + *ret = le64toh(o->entry_array.next_entry_array_offset); + return 0; + } + + /* Entry array chains are a singly linked list, so to find the previous array in the chain, we have + * to start iterating from the top. */ + + p = first; + + while (p > 0 && p != offset) { + r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, p, &o); + if (r < 0) + return r; + + q = p; + p = le64toh(o->entry_array.next_entry_array_offset); + } + + /* If we can't find the previous entry array in the entry array chain, we're likely dealing with a + * corrupted journal file. */ + if (p == 0) + return -EBADMSG; + + *ret = q; + + return 0; +} + +static int generic_array_get( + JournalFile *f, + uint64_t first, + uint64_t i, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t p = 0, a, t = 0, k; + ChainCacheItem *ci; + Object *o; + int r; + + assert(f); + + /* FIXME: fix return value assignment on success. */ + + a = first; + + /* Try the chain cache first */ + ci = ordered_hashmap_get(f->chain_cache, &first); + if (ci && i > ci->total) { + a = ci->array; + i -= ci->total; + t = ci->total; + } + + while (a > 0) { + r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o); + if (IN_SET(r, -EBADMSG, -EADDRNOTAVAIL)) { + /* If there's corruption and we're going downwards, let's pretend we reached the + * final entry in the entry array chain. */ + + if (direction == DIRECTION_DOWN) + return 0; + + /* If there's corruption and we're going upwards, move back to the previous entry + * array and start iterating entries from there. */ + + r = bump_entry_array(f, NULL, a, first, DIRECTION_UP, &a); + if (r < 0) + return r; + + i = UINT64_MAX; + + break; + } + if (r < 0) + return r; + + k = journal_file_entry_array_n_items(f, o); + if (i < k) + break; + + i -= k; + t += k; + a = le64toh(o->entry_array.next_entry_array_offset); + } + + /* If we've found the right location, now look for the first non-corrupt entry object (in the right + * direction). */ + + while (a > 0) { + /* In the first iteration of the while loop, we reuse i, k and o from the previous while + * loop. */ + if (i == UINT64_MAX) { + r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o); + if (r < 0) + return r; + + k = journal_file_entry_array_n_items(f, o); + if (k == 0) + break; + + i = direction == DIRECTION_DOWN ? 0 : k - 1; + } + + do { + p = journal_file_entry_array_item(f, o, i); + + r = journal_file_move_to_object(f, OBJECT_ENTRY, p, ret_object); + if (r >= 0) { + /* Let's cache this item for the next invocation */ + chain_cache_put(f->chain_cache, ci, first, a, journal_file_entry_array_item(f, o, 0), t, i); + + if (ret_offset) + *ret_offset = p; + + return 1; + } + if (!IN_SET(r, -EADDRNOTAVAIL, -EBADMSG)) + return r; + + /* OK, so this entry is borked. Most likely some entry didn't get synced to + * disk properly, let's see if the next one might work for us instead. */ + log_debug_errno(r, "Entry item %" PRIu64 " is bad, skipping over it.", i); + } while (bump_array_index(&i, direction, k) > 0); + + r = bump_entry_array(f, o, a, first, direction, &a); + if (r < 0) + return r; + + t += k; + i = UINT64_MAX; + } + + return 0; +} + +static int generic_array_get_plus_one( + JournalFile *f, + uint64_t extra, + uint64_t first, + uint64_t i, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + int r; + + assert(f); + + /* FIXME: fix return value assignment on success. */ + + if (i == 0) { + r = journal_file_move_to_object(f, OBJECT_ENTRY, extra, ret_object); + if (IN_SET(r, -EADDRNOTAVAIL, -EBADMSG)) + return generic_array_get(f, first, 0, direction, ret_object, ret_offset); + if (r < 0) + return r; + + if (ret_offset) + *ret_offset = extra; + + return 1; + } + + return generic_array_get(f, first, i - 1, direction, ret_object, ret_offset); +} + +enum { + TEST_FOUND, + TEST_LEFT, + TEST_RIGHT +}; + +static int generic_array_bisect( + JournalFile *f, + uint64_t first, + uint64_t n, + uint64_t needle, + int (*test_object)(JournalFile *f, uint64_t p, uint64_t needle), + direction_t direction, + Object **ret_object, + uint64_t *ret_offset, + uint64_t *ret_idx) { + + /* Given an entry array chain, this function finds the object "closest" to the given needle in the + * chain, taking into account the provided direction. A function can be provided to determine how + * an object is matched against the given needle. + * + * Given a journal file, the offset of an object and the needle, the test_object() function should + * return TEST_LEFT if the needle is located earlier in the entry array chain, TEST_RIGHT if the + * needle is located later in the entry array chain and TEST_FOUND if the object matches the needle. + * If test_object() returns TEST_FOUND for a specific object, that object's information will be used + * to populate the return values of this function. If test_object() never returns TEST_FOUND, the + * return values are populated with the details of one of the objects closest to the needle. If the + * direction is DIRECTION_UP, the earlier object is used. Otherwise, the later object is used. + */ + + uint64_t a, p, t = 0, i = 0, last_p = 0, last_index = UINT64_MAX; + bool subtract_one = false; + Object *array = NULL; + ChainCacheItem *ci; + int r; + + assert(f); + assert(test_object); + + /* Start with the first array in the chain */ + a = first; + + ci = ordered_hashmap_get(f->chain_cache, &first); + if (ci && n > ci->total && ci->begin != 0) { + /* Ah, we have iterated this bisection array chain + * previously! Let's see if we can skip ahead in the + * chain, as far as the last time. But we can't jump + * backwards in the chain, so let's check that + * first. */ + + r = test_object(f, ci->begin, needle); + if (r < 0) + return r; + + if (r == TEST_LEFT) { + /* OK, what we are looking for is right of the + * begin of this EntryArray, so let's jump + * straight to previously cached array in the + * chain */ + + a = ci->array; + n -= ci->total; + t = ci->total; + last_index = ci->last_index; + } + } + + while (a > 0) { + uint64_t left, right, k, lp; + + r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &array); + if (r < 0) + return r; + + k = journal_file_entry_array_n_items(f, array); + right = MIN(k, n); + if (right <= 0) + return 0; + + i = right - 1; + lp = p = journal_file_entry_array_item(f, array, i); + if (p <= 0) + r = -EBADMSG; + else + r = test_object(f, p, needle); + if (r == -EBADMSG) { + log_debug_errno(r, "Encountered invalid entry while bisecting, cutting algorithm short. (1)"); + n = i; + continue; + } + if (r < 0) + return r; + + if (r == TEST_FOUND) + r = direction == DIRECTION_DOWN ? TEST_RIGHT : TEST_LEFT; + + if (r == TEST_RIGHT) { + left = 0; + right -= 1; + + if (last_index != UINT64_MAX) { + assert(last_index <= right); + + /* If we cached the last index we + * looked at, let's try to not to jump + * too wildly around and see if we can + * limit the range to look at early to + * the immediate neighbors of the last + * index we looked at. */ + + if (last_index > 0) { + uint64_t x = last_index - 1; + + p = journal_file_entry_array_item(f, array, x); + if (p <= 0) + return -EBADMSG; + + r = test_object(f, p, needle); + if (r < 0) + return r; + + if (r == TEST_FOUND) + r = direction == DIRECTION_DOWN ? TEST_RIGHT : TEST_LEFT; + + if (r == TEST_RIGHT) + right = x; + else + left = x + 1; + } + + if (last_index < right) { + uint64_t y = last_index + 1; + + p = journal_file_entry_array_item(f, array, y); + if (p <= 0) + return -EBADMSG; + + r = test_object(f, p, needle); + if (r < 0) + return r; + + if (r == TEST_FOUND) + r = direction == DIRECTION_DOWN ? TEST_RIGHT : TEST_LEFT; + + if (r == TEST_RIGHT) + right = y; + else + left = y + 1; + } + } + + for (;;) { + if (left == right) { + if (direction == DIRECTION_UP) + subtract_one = true; + + i = left; + goto found; + } + + assert(left < right); + i = (left + right) / 2; + + p = journal_file_entry_array_item(f, array, i); + if (p <= 0) + r = -EBADMSG; + else + r = test_object(f, p, needle); + if (r == -EBADMSG) { + log_debug_errno(r, "Encountered invalid entry while bisecting, cutting algorithm short. (2)"); + right = n = i; + continue; + } + if (r < 0) + return r; + + if (r == TEST_FOUND) + r = direction == DIRECTION_DOWN ? TEST_RIGHT : TEST_LEFT; + + if (r == TEST_RIGHT) + right = i; + else + left = i + 1; + } + } + + if (k >= n) { + if (direction == DIRECTION_UP) { + i = n; + subtract_one = true; + goto found; + } + + return 0; + } + + last_p = lp; + + n -= k; + t += k; + last_index = UINT64_MAX; + a = le64toh(array->entry_array.next_entry_array_offset); + } + + return 0; + +found: + if (subtract_one && t == 0 && i == 0) + return 0; + + /* Let's cache this item for the next invocation */ + chain_cache_put(f->chain_cache, ci, first, a, journal_file_entry_array_item(f, array, 0), t, subtract_one ? (i > 0 ? i-1 : UINT64_MAX) : i); + + if (subtract_one && i == 0) + p = last_p; + else if (subtract_one) + p = journal_file_entry_array_item(f, array, i - 1); + else + p = journal_file_entry_array_item(f, array, i); + + if (ret_object) { + r = journal_file_move_to_object(f, OBJECT_ENTRY, p, ret_object); + if (r < 0) + return r; + } + + if (ret_offset) + *ret_offset = p; + + if (ret_idx) + *ret_idx = t + i + (subtract_one ? -1 : 0); + + return 1; +} + +static int generic_array_bisect_plus_one( + JournalFile *f, + uint64_t extra, + uint64_t first, + uint64_t n, + uint64_t needle, + int (*test_object)(JournalFile *f, uint64_t p, uint64_t needle), + direction_t direction, + Object **ret_object, + uint64_t *ret_offset, + uint64_t *ret_idx) { + + int r; + bool step_back = false; + + assert(f); + assert(test_object); + + if (n <= 0) + return 0; + + /* This bisects the array in object 'first', but first checks + * an extra */ + r = test_object(f, extra, needle); + if (r < 0) + return r; + + if (r == TEST_FOUND) + r = direction == DIRECTION_DOWN ? TEST_RIGHT : TEST_LEFT; + + /* if we are looking with DIRECTION_UP then we need to first + see if in the actual array there is a matching entry, and + return the last one of that. But if there isn't any we need + to return this one. Hence remember this, and return it + below. */ + if (r == TEST_LEFT) + step_back = direction == DIRECTION_UP; + + if (r == TEST_RIGHT) { + if (direction == DIRECTION_DOWN) + goto found; + else + return 0; + } + + r = generic_array_bisect(f, first, n-1, needle, test_object, direction, ret_object, ret_offset, ret_idx); + + if (r == 0 && step_back) + goto found; + + if (r > 0 && ret_idx) + (*ret_idx)++; + + return r; + +found: + if (ret_object) { + r = journal_file_move_to_object(f, OBJECT_ENTRY, extra, ret_object); + if (r < 0) + return r; + } + + if (ret_offset) + *ret_offset = extra; + + if (ret_idx) + *ret_idx = 0; + + return 1; +} + +_pure_ static int test_object_offset(JournalFile *f, uint64_t p, uint64_t needle) { + assert(f); + assert(p > 0); + + if (p == needle) + return TEST_FOUND; + else if (p < needle) + return TEST_LEFT; + else + return TEST_RIGHT; +} + +int journal_file_move_to_entry_by_offset( + JournalFile *f, + uint64_t p, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + assert(f); + assert(f->header); + + return generic_array_bisect( + f, + le64toh(f->header->entry_array_offset), + le64toh(f->header->n_entries), + p, + test_object_offset, + direction, + ret_object, ret_offset, NULL); +} + +static int test_object_seqnum(JournalFile *f, uint64_t p, uint64_t needle) { + uint64_t sq; + Object *o; + int r; + + assert(f); + assert(p > 0); + + r = journal_file_move_to_object(f, OBJECT_ENTRY, p, &o); + if (r < 0) + return r; + + sq = le64toh(READ_NOW(o->entry.seqnum)); + if (sq == needle) + return TEST_FOUND; + else if (sq < needle) + return TEST_LEFT; + else + return TEST_RIGHT; +} + +int journal_file_move_to_entry_by_seqnum( + JournalFile *f, + uint64_t seqnum, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + assert(f); + assert(f->header); + + return generic_array_bisect( + f, + le64toh(f->header->entry_array_offset), + le64toh(f->header->n_entries), + seqnum, + test_object_seqnum, + direction, + ret_object, ret_offset, NULL); +} + +static int test_object_realtime(JournalFile *f, uint64_t p, uint64_t needle) { + Object *o; + uint64_t rt; + int r; + + assert(f); + assert(p > 0); + + r = journal_file_move_to_object(f, OBJECT_ENTRY, p, &o); + if (r < 0) + return r; + + rt = le64toh(READ_NOW(o->entry.realtime)); + if (rt == needle) + return TEST_FOUND; + else if (rt < needle) + return TEST_LEFT; + else + return TEST_RIGHT; +} + +int journal_file_move_to_entry_by_realtime( + JournalFile *f, + uint64_t realtime, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + assert(f); + assert(f->header); + + return generic_array_bisect( + f, + le64toh(f->header->entry_array_offset), + le64toh(f->header->n_entries), + realtime, + test_object_realtime, + direction, + ret_object, ret_offset, NULL); +} + +static int test_object_monotonic(JournalFile *f, uint64_t p, uint64_t needle) { + Object *o; + uint64_t m; + int r; + + assert(f); + assert(p > 0); + + r = journal_file_move_to_object(f, OBJECT_ENTRY, p, &o); + if (r < 0) + return r; + + m = le64toh(READ_NOW(o->entry.monotonic)); + if (m == needle) + return TEST_FOUND; + else if (m < needle) + return TEST_LEFT; + else + return TEST_RIGHT; +} + +static int find_data_object_by_boot_id( + JournalFile *f, + sd_id128_t boot_id, + Object **ret_object, + uint64_t *ret_offset) { + + char t[STRLEN("_BOOT_ID=") + 32 + 1] = "_BOOT_ID="; + + assert(f); + + sd_id128_to_string(boot_id, t + 9); + return journal_file_find_data_object(f, t, sizeof(t) - 1, ret_object, ret_offset); +} + +int journal_file_move_to_entry_by_monotonic( + JournalFile *f, + sd_id128_t boot_id, + uint64_t monotonic, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + Object *o; + int r; + + assert(f); + + r = find_data_object_by_boot_id(f, boot_id, &o, NULL); + if (r <= 0) + return r; + + return generic_array_bisect_plus_one( + f, + le64toh(o->data.entry_offset), + le64toh(o->data.entry_array_offset), + le64toh(o->data.n_entries), + monotonic, + test_object_monotonic, + direction, + ret_object, ret_offset, NULL); +} + +void journal_file_reset_location(JournalFile *f) { + assert(f); + + f->location_type = LOCATION_HEAD; + f->current_offset = 0; + f->current_seqnum = 0; + f->current_realtime = 0; + f->current_monotonic = 0; + zero(f->current_boot_id); + f->current_xor_hash = 0; +} + +void journal_file_save_location(JournalFile *f, Object *o, uint64_t offset) { + assert(f); + assert(o); + + f->location_type = LOCATION_SEEK; + f->current_offset = offset; + f->current_seqnum = le64toh(o->entry.seqnum); + f->current_realtime = le64toh(o->entry.realtime); + f->current_monotonic = le64toh(o->entry.monotonic); + f->current_boot_id = o->entry.boot_id; + f->current_xor_hash = le64toh(o->entry.xor_hash); +} + +int journal_file_compare_locations(JournalFile *af, JournalFile *bf) { + int r; + + assert(af); + assert(af->header); + assert(bf); + assert(bf->header); + assert(af->location_type == LOCATION_SEEK); + assert(bf->location_type == LOCATION_SEEK); + + /* If contents, timestamps and seqnum match, these entries are + * identical. */ + if (sd_id128_equal(af->current_boot_id, bf->current_boot_id) && + af->current_monotonic == bf->current_monotonic && + af->current_realtime == bf->current_realtime && + af->current_xor_hash == bf->current_xor_hash && + sd_id128_equal(af->header->seqnum_id, bf->header->seqnum_id) && + af->current_seqnum == bf->current_seqnum) + return 0; + + if (sd_id128_equal(af->header->seqnum_id, bf->header->seqnum_id)) { + + /* If this is from the same seqnum source, compare + * seqnums */ + r = CMP(af->current_seqnum, bf->current_seqnum); + if (r != 0) + return r; + + /* Wow! This is weird, different data but the same + * seqnums? Something is borked, but let's make the + * best of it and compare by time. */ + } + + if (sd_id128_equal(af->current_boot_id, bf->current_boot_id)) { + + /* If the boot id matches, compare monotonic time */ + r = CMP(af->current_monotonic, bf->current_monotonic); + if (r != 0) + return r; + } + + /* Otherwise, compare UTC time */ + r = CMP(af->current_realtime, bf->current_realtime); + if (r != 0) + return r; + + /* Finally, compare by contents */ + return CMP(af->current_xor_hash, bf->current_xor_hash); +} + +static bool check_properly_ordered(uint64_t new_offset, uint64_t old_offset, direction_t direction) { + + /* Consider it an error if any of the two offsets is uninitialized */ + if (old_offset == 0 || new_offset == 0) + return false; + + /* If we go down, the new offset must be larger than the old one. */ + return direction == DIRECTION_DOWN ? + new_offset > old_offset : + new_offset < old_offset; +} + +int journal_file_next_entry( + JournalFile *f, + uint64_t p, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t i, n, ofs; + int r; + + assert(f); + assert(f->header); + + /* FIXME: fix return value assignment. */ + + n = le64toh(READ_NOW(f->header->n_entries)); + if (n <= 0) + return 0; + + if (p == 0) + i = direction == DIRECTION_DOWN ? 0 : n - 1; + else { + r = generic_array_bisect(f, + le64toh(f->header->entry_array_offset), + le64toh(f->header->n_entries), + p, + test_object_offset, + DIRECTION_DOWN, + NULL, NULL, + &i); + if (r <= 0) + return r; + + r = bump_array_index(&i, direction, n); + if (r <= 0) + return r; + } + + /* And jump to it */ + r = generic_array_get(f, le64toh(f->header->entry_array_offset), i, direction, ret_object, &ofs); + if (r <= 0) + return r; + + /* Ensure our array is properly ordered. */ + if (p > 0 && !check_properly_ordered(ofs, p, direction)) + return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), + "%s: entry array not properly ordered at entry %" PRIu64, + f->path, i); + + if (ret_offset) + *ret_offset = ofs; + + return 1; +} + +int journal_file_next_entry_for_data( + JournalFile *f, + Object *d, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t i, n, ofs; + int r; + + assert(f); + assert(d); + assert(d->object.type == OBJECT_DATA); + + /* FIXME: fix return value assignment. */ + + n = le64toh(READ_NOW(d->data.n_entries)); + if (n <= 0) + return n; + + i = direction == DIRECTION_DOWN ? 0 : n - 1; + + r = generic_array_get_plus_one(f, + le64toh(d->data.entry_offset), + le64toh(d->data.entry_array_offset), + i, + direction, + ret_object, &ofs); + if (r <= 0) + return r; + + if (ret_offset) + *ret_offset = ofs; + + return 1; +} + +int journal_file_move_to_entry_by_offset_for_data( + JournalFile *f, + Object *d, + uint64_t p, + direction_t direction, + Object **ret, uint64_t *ret_offset) { + + assert(f); + assert(d); + assert(d->object.type == OBJECT_DATA); + + return generic_array_bisect_plus_one( + f, + le64toh(d->data.entry_offset), + le64toh(d->data.entry_array_offset), + le64toh(d->data.n_entries), + p, + test_object_offset, + direction, + ret, ret_offset, NULL); +} + +int journal_file_move_to_entry_by_monotonic_for_data( + JournalFile *f, + Object *d, + sd_id128_t boot_id, + uint64_t monotonic, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + uint64_t b, z, entry_offset, entry_array_offset, n_entries; + Object *o; + int r; + + assert(f); + assert(d); + assert(d->object.type == OBJECT_DATA); + + /* Save all the required data before the data object gets invalidated. */ + entry_offset = le64toh(READ_NOW(d->data.entry_offset)); + entry_array_offset = le64toh(READ_NOW(d->data.entry_array_offset)); + n_entries = le64toh(READ_NOW(d->data.n_entries)); + + /* First, seek by time */ + r = find_data_object_by_boot_id(f, boot_id, &o, &b); + if (r <= 0) + return r; + + r = generic_array_bisect_plus_one(f, + le64toh(o->data.entry_offset), + le64toh(o->data.entry_array_offset), + le64toh(o->data.n_entries), + monotonic, + test_object_monotonic, + direction, + NULL, &z, NULL); + if (r <= 0) + return r; + + /* And now, continue seeking until we find an entry that + * exists in both bisection arrays */ + + r = journal_file_move_to_object(f, OBJECT_DATA, b, &o); + if (r < 0) + return r; + + for (;;) { + uint64_t p, q; + + r = generic_array_bisect_plus_one(f, + entry_offset, + entry_array_offset, + n_entries, + z, + test_object_offset, + direction, + NULL, &p, NULL); + if (r <= 0) + return r; + + r = generic_array_bisect_plus_one(f, + le64toh(o->data.entry_offset), + le64toh(o->data.entry_array_offset), + le64toh(o->data.n_entries), + p, + test_object_offset, + direction, + NULL, &q, NULL); + + if (r <= 0) + return r; + + if (p == q) { + if (ret_object) { + r = journal_file_move_to_object(f, OBJECT_ENTRY, q, ret_object); + if (r < 0) + return r; + } + + if (ret_offset) + *ret_offset = q; + + return 1; + } + + z = q; + } +} + +int journal_file_move_to_entry_by_seqnum_for_data( + JournalFile *f, + Object *d, + uint64_t seqnum, + direction_t direction, + Object **ret_object, + uint64_t *ret_offset) { + + assert(f); + assert(d); + assert(d->object.type == OBJECT_DATA); + + return generic_array_bisect_plus_one( + f, + le64toh(d->data.entry_offset), + le64toh(d->data.entry_array_offset), + le64toh(d->data.n_entries), + seqnum, + test_object_seqnum, + direction, + ret_object, ret_offset, NULL); +} + +int journal_file_move_to_entry_by_realtime_for_data( + JournalFile *f, + Object *d, + uint64_t realtime, + direction_t direction, + Object **ret, uint64_t *ret_offset) { + + assert(f); + assert(d); + assert(d->object.type == OBJECT_DATA); + + return generic_array_bisect_plus_one( + f, + le64toh(d->data.entry_offset), + le64toh(d->data.entry_array_offset), + le64toh(d->data.n_entries), + realtime, + test_object_realtime, + direction, + ret, ret_offset, NULL); +} + +void journal_file_dump(JournalFile *f) { + Object *o; + uint64_t p; + int r; + + assert(f); + assert(f->header); + + journal_file_print_header(f); + + p = le64toh(READ_NOW(f->header->header_size)); + while (p != 0) { + const char *s; + Compression c; + + r = journal_file_move_to_object(f, OBJECT_UNUSED, p, &o); + if (r < 0) + goto fail; + + s = journal_object_type_to_string(o->object.type); + + switch (o->object.type) { + + case OBJECT_ENTRY: + assert(s); + + printf("Type: %s seqnum=%"PRIu64" monotonic=%"PRIu64" realtime=%"PRIu64"\n", + s, + le64toh(o->entry.seqnum), + le64toh(o->entry.monotonic), + le64toh(o->entry.realtime)); + break; + + case OBJECT_TAG: + assert(s); + + printf("Type: %s seqnum=%"PRIu64" epoch=%"PRIu64"\n", + s, + le64toh(o->tag.seqnum), + le64toh(o->tag.epoch)); + break; + + default: + if (s) + printf("Type: %s \n", s); + else + printf("Type: unknown (%i)", o->object.type); + + break; + } + + c = COMPRESSION_FROM_OBJECT(o); + if (c > COMPRESSION_NONE) + printf("Flags: %s\n", + compression_to_string(c)); + + if (p == le64toh(f->header->tail_object_offset)) + p = 0; + else + p += ALIGN64(le64toh(o->object.size)); + } + + return; +fail: + log_error("File corrupt"); +} + +/* Note: the lifetime of the compound literal is the immediately surrounding block. */ +#define FORMAT_TIMESTAMP_SAFE(t) (FORMAT_TIMESTAMP(t) ?: " --- ") + +void journal_file_print_header(JournalFile *f) { + struct stat st; + + assert(f); + assert(f->header); + + printf("File path: %s\n" + "File ID: %s\n" + "Machine ID: %s\n" + "Boot ID: %s\n" + "Sequential number ID: %s\n" + "State: %s\n" + "Compatible flags:%s%s\n" + "Incompatible flags:%s%s%s%s%s%s\n" + "Header size: %"PRIu64"\n" + "Arena size: %"PRIu64"\n" + "Data hash table size: %"PRIu64"\n" + "Field hash table size: %"PRIu64"\n" + "Rotate suggested: %s\n" + "Head sequential number: %"PRIu64" (%"PRIx64")\n" + "Tail sequential number: %"PRIu64" (%"PRIx64")\n" + "Head realtime timestamp: %s (%"PRIx64")\n" + "Tail realtime timestamp: %s (%"PRIx64")\n" + "Tail monotonic timestamp: %s (%"PRIx64")\n" + "Objects: %"PRIu64"\n" + "Entry objects: %"PRIu64"\n", + f->path, + SD_ID128_TO_STRING(f->header->file_id), + SD_ID128_TO_STRING(f->header->machine_id), + SD_ID128_TO_STRING(f->header->boot_id), + SD_ID128_TO_STRING(f->header->seqnum_id), + f->header->state == STATE_OFFLINE ? "OFFLINE" : + f->header->state == STATE_ONLINE ? "ONLINE" : + f->header->state == STATE_ARCHIVED ? "ARCHIVED" : "UNKNOWN", + JOURNAL_HEADER_SEALED(f->header) ? " SEALED" : "", + (le32toh(f->header->compatible_flags) & ~HEADER_COMPATIBLE_ANY) ? " ???" : "", + JOURNAL_HEADER_COMPRESSED_XZ(f->header) ? " COMPRESSED-XZ" : "", + JOURNAL_HEADER_COMPRESSED_LZ4(f->header) ? " COMPRESSED-LZ4" : "", + JOURNAL_HEADER_COMPRESSED_ZSTD(f->header) ? " COMPRESSED-ZSTD" : "", + JOURNAL_HEADER_KEYED_HASH(f->header) ? " KEYED-HASH" : "", + JOURNAL_HEADER_COMPACT(f->header) ? " COMPACT" : "", + (le32toh(f->header->incompatible_flags) & ~HEADER_INCOMPATIBLE_ANY) ? " ???" : "", + le64toh(f->header->header_size), + le64toh(f->header->arena_size), + le64toh(f->header->data_hash_table_size) / sizeof(HashItem), + le64toh(f->header->field_hash_table_size) / sizeof(HashItem), + yes_no(journal_file_rotate_suggested(f, 0, LOG_DEBUG)), + le64toh(f->header->head_entry_seqnum), le64toh(f->header->head_entry_seqnum), + le64toh(f->header->tail_entry_seqnum), le64toh(f->header->tail_entry_seqnum), + FORMAT_TIMESTAMP_SAFE(le64toh(f->header->head_entry_realtime)), le64toh(f->header->head_entry_realtime), + FORMAT_TIMESTAMP_SAFE(le64toh(f->header->tail_entry_realtime)), le64toh(f->header->tail_entry_realtime), + FORMAT_TIMESPAN(le64toh(f->header->tail_entry_monotonic), USEC_PER_MSEC), le64toh(f->header->tail_entry_monotonic), + le64toh(f->header->n_objects), + le64toh(f->header->n_entries)); + + if (JOURNAL_HEADER_CONTAINS(f->header, n_data)) + printf("Data objects: %"PRIu64"\n" + "Data hash table fill: %.1f%%\n", + le64toh(f->header->n_data), + 100.0 * (double) le64toh(f->header->n_data) / ((double) (le64toh(f->header->data_hash_table_size) / sizeof(HashItem)))); + + if (JOURNAL_HEADER_CONTAINS(f->header, n_fields)) + printf("Field objects: %"PRIu64"\n" + "Field hash table fill: %.1f%%\n", + le64toh(f->header->n_fields), + 100.0 * (double) le64toh(f->header->n_fields) / ((double) (le64toh(f->header->field_hash_table_size) / sizeof(HashItem)))); + + if (JOURNAL_HEADER_CONTAINS(f->header, n_tags)) + printf("Tag objects: %"PRIu64"\n", + le64toh(f->header->n_tags)); + if (JOURNAL_HEADER_CONTAINS(f->header, n_entry_arrays)) + printf("Entry array objects: %"PRIu64"\n", + le64toh(f->header->n_entry_arrays)); + + if (JOURNAL_HEADER_CONTAINS(f->header, field_hash_chain_depth)) + printf("Deepest field hash chain: %" PRIu64"\n", + f->header->field_hash_chain_depth); + + if (JOURNAL_HEADER_CONTAINS(f->header, data_hash_chain_depth)) + printf("Deepest data hash chain: %" PRIu64"\n", + f->header->data_hash_chain_depth); + + if (fstat(f->fd, &st) >= 0) + printf("Disk usage: %s\n", FORMAT_BYTES((uint64_t) st.st_blocks * 512ULL)); +} + +static int journal_file_warn_btrfs(JournalFile *f) { + unsigned attrs; + int r; + + assert(f); + + /* Before we write anything, check if the COW logic is turned + * off on btrfs. Given our write pattern that is quite + * unfriendly to COW file systems this should greatly improve + * performance on COW file systems, such as btrfs, at the + * expense of data integrity features (which shouldn't be too + * bad, given that we do our own checksumming). */ + + r = fd_is_fs_type(f->fd, BTRFS_SUPER_MAGIC); + if (r < 0) + return log_warning_errno(r, "Failed to determine if journal is on btrfs: %m"); + if (!r) + return 0; + + r = read_attr_fd(f->fd, &attrs); + if (r < 0) + return log_warning_errno(r, "Failed to read file attributes: %m"); + + if (attrs & FS_NOCOW_FL) { + log_debug("Detected btrfs file system with copy-on-write disabled, all is good."); + return 0; + } + + log_notice("Creating journal file %s on a btrfs file system, and copy-on-write is enabled. " + "This is likely to slow down journal access substantially, please consider turning " + "off the copy-on-write file attribute on the journal directory, using chattr +C.", f->path); + + return 1; +} + +static void journal_default_metrics(JournalMetrics *m, int fd, bool compact) { + struct statvfs ss; + uint64_t fs_size = 0; + + assert(m); + assert(fd >= 0); + + if (fstatvfs(fd, &ss) >= 0) + fs_size = ss.f_frsize * ss.f_blocks; + else + log_debug_errno(errno, "Failed to determine disk size: %m"); + + if (m->max_use == UINT64_MAX) { + + if (fs_size > 0) + m->max_use = CLAMP(PAGE_ALIGN(fs_size / 10), /* 10% of file system size */ + MAX_USE_LOWER, MAX_USE_UPPER); + else + m->max_use = MAX_USE_LOWER; + } else { + m->max_use = PAGE_ALIGN(m->max_use); + + if (m->max_use != 0 && m->max_use < JOURNAL_FILE_SIZE_MIN*2) + m->max_use = JOURNAL_FILE_SIZE_MIN*2; + } + + if (m->min_use == UINT64_MAX) { + if (fs_size > 0) + m->min_use = CLAMP(PAGE_ALIGN(fs_size / 50), /* 2% of file system size */ + MIN_USE_LOW, MIN_USE_HIGH); + else + m->min_use = MIN_USE_LOW; + } + + if (m->min_use > m->max_use) + m->min_use = m->max_use; + + if (m->max_size == UINT64_MAX) + m->max_size = MIN(PAGE_ALIGN(m->max_use / 8), /* 8 chunks */ + MAX_SIZE_UPPER); + else + m->max_size = PAGE_ALIGN(m->max_size); + + if (compact && m->max_size > JOURNAL_COMPACT_SIZE_MAX) + m->max_size = JOURNAL_COMPACT_SIZE_MAX; + + if (m->max_size != 0) { + if (m->max_size < JOURNAL_FILE_SIZE_MIN) + m->max_size = JOURNAL_FILE_SIZE_MIN; + + if (m->max_use != 0 && m->max_size*2 > m->max_use) + m->max_use = m->max_size*2; + } + + if (m->min_size == UINT64_MAX) + m->min_size = JOURNAL_FILE_SIZE_MIN; + else + m->min_size = CLAMP(PAGE_ALIGN(m->min_size), + JOURNAL_FILE_SIZE_MIN, + m->max_size ?: UINT64_MAX); + + if (m->keep_free == UINT64_MAX) { + if (fs_size > 0) + m->keep_free = MIN(PAGE_ALIGN(fs_size / 20), /* 5% of file system size */ + KEEP_FREE_UPPER); + else + m->keep_free = DEFAULT_KEEP_FREE; + } + + if (m->n_max_files == UINT64_MAX) + m->n_max_files = DEFAULT_N_MAX_FILES; + + log_debug("Fixed min_use=%s max_use=%s max_size=%s min_size=%s keep_free=%s n_max_files=%" PRIu64, + FORMAT_BYTES(m->min_use), + FORMAT_BYTES(m->max_use), + FORMAT_BYTES(m->max_size), + FORMAT_BYTES(m->min_size), + FORMAT_BYTES(m->keep_free), + m->n_max_files); +} + +int journal_file_open( + int fd, + const char *fname, + int open_flags, + JournalFileFlags file_flags, + mode_t mode, + uint64_t compress_threshold_bytes, + JournalMetrics *metrics, + MMapCache *mmap_cache, + JournalFile *template, + JournalFile **ret) { + + bool newly_created = false; + JournalFile *f; + void *h; + int r; + + assert(fd >= 0 || fname); + assert(mmap_cache); + assert(ret); + + if (!IN_SET((open_flags & O_ACCMODE), O_RDONLY, O_RDWR)) + return -EINVAL; + + if ((open_flags & O_ACCMODE) == O_RDONLY && FLAGS_SET(open_flags, O_CREAT)) + return -EINVAL; + + if (fname && (open_flags & O_CREAT) && !endswith(fname, ".journal")) + return -EINVAL; + + f = new(JournalFile, 1); + if (!f) + return -ENOMEM; + + *f = (JournalFile) { + .fd = fd, + .mode = mode, + .open_flags = open_flags, + .compress_threshold_bytes = compress_threshold_bytes == UINT64_MAX ? + DEFAULT_COMPRESS_THRESHOLD : + MAX(MIN_COMPRESS_THRESHOLD, compress_threshold_bytes), + }; + + if (fname) { + f->path = strdup(fname); + if (!f->path) { + r = -ENOMEM; + goto fail; + } + } else { + assert(fd >= 0); + + /* If we don't know the path, fill in something explanatory and vaguely useful */ + if (asprintf(&f->path, "/proc/self/%i", fd) < 0) { + r = -ENOMEM; + goto fail; + } + } + + f->chain_cache = ordered_hashmap_new(&uint64_hash_ops); + if (!f->chain_cache) { + r = -ENOMEM; + goto fail; + } + + if (f->fd < 0) { + /* We pass O_NONBLOCK here, so that in case somebody pointed us to some character device node or FIFO + * or so, we likely fail quickly than block for long. For regular files O_NONBLOCK has no effect, hence + * it doesn't hurt in that case. */ + + f->fd = openat_report_new(AT_FDCWD, f->path, f->open_flags|O_CLOEXEC|O_NONBLOCK, f->mode, &newly_created); + if (f->fd < 0) { + r = f->fd; + goto fail; + } + + /* fds we opened here by us should also be closed by us. */ + f->close_fd = true; + + r = fd_nonblock(f->fd, false); + if (r < 0) + goto fail; + + if (!newly_created) { + r = journal_file_fstat(f); + if (r < 0) + goto fail; + } + } else { + r = journal_file_fstat(f); + if (r < 0) + goto fail; + + /* If we just got the fd passed in, we don't really know if we created the file anew */ + newly_created = f->last_stat.st_size == 0 && journal_file_writable(f); + } + + f->cache_fd = mmap_cache_add_fd(mmap_cache, f->fd, prot_from_flags(open_flags)); + if (!f->cache_fd) { + r = -ENOMEM; + goto fail; + } + + if (newly_created) { + (void) journal_file_warn_btrfs(f); + + /* Let's attach the creation time to the journal file, so that the vacuuming code knows the age of this + * file even if the file might end up corrupted one day... Ideally we'd just use the creation time many + * file systems maintain for each file, but the API to query this is very new, hence let's emulate this + * via extended attributes. If extended attributes are not supported we'll just skip this, and rely + * solely on mtime/atime/ctime of the file. */ + (void) fd_setcrtime(f->fd, 0); + + r = journal_file_init_header(f, file_flags, template); + if (r < 0) + goto fail; + + r = journal_file_fstat(f); + if (r < 0) + goto fail; + } + + if (f->last_stat.st_size < (off_t) HEADER_SIZE_MIN) { + r = -ENODATA; + goto fail; + } + + r = mmap_cache_fd_get(f->cache_fd, CONTEXT_HEADER, true, 0, PAGE_ALIGN(sizeof(Header)), &f->last_stat, &h); + if (r == -EINVAL) { + /* Some file systems (jffs2 or p9fs) don't support mmap() properly (or only read-only + * mmap()), and return EINVAL in that case. Let's propagate that as a more recognizable error + * code. */ + r = -EAFNOSUPPORT; + goto fail; + } + if (r < 0) + goto fail; + + f->header = h; + + if (!newly_created) { + r = journal_file_verify_header(f); + if (r < 0) + goto fail; + } + +#if HAVE_GCRYPT + if (!newly_created && journal_file_writable(f) && JOURNAL_HEADER_SEALED(f->header)) { + r = journal_file_fss_load(f); + if (r < 0) + goto fail; + } +#endif + + if (journal_file_writable(f)) { + if (metrics) { + journal_default_metrics(metrics, f->fd, JOURNAL_HEADER_COMPACT(f->header)); + f->metrics = *metrics; + } else if (template) + f->metrics = template->metrics; + + r = journal_file_refresh_header(f); + if (r < 0) + goto fail; + } + +#if HAVE_GCRYPT + r = journal_file_hmac_setup(f); + if (r < 0) + goto fail; +#endif + + if (newly_created) { + r = journal_file_setup_field_hash_table(f); + if (r < 0) + goto fail; + + r = journal_file_setup_data_hash_table(f); + if (r < 0) + goto fail; + +#if HAVE_GCRYPT + r = journal_file_append_first_tag(f); + if (r < 0) + goto fail; +#endif + } + + if (mmap_cache_fd_got_sigbus(f->cache_fd)) { + r = -EIO; + goto fail; + } + + if (template && template->post_change_timer) { + r = journal_file_enable_post_change_timer( + f, + sd_event_source_get_event(template->post_change_timer), + template->post_change_timer_period); + + if (r < 0) + goto fail; + } + + /* The file is opened now successfully, thus we take possession of any passed in fd. */ + f->close_fd = true; + + if (DEBUG_LOGGING) { + static int last_seal = -1, last_compress = -1, last_keyed_hash = -1; + static uint64_t last_bytes = UINT64_MAX; + + if (last_seal != JOURNAL_HEADER_SEALED(f->header) || + last_keyed_hash != JOURNAL_HEADER_KEYED_HASH(f->header) || + last_compress != JOURNAL_FILE_COMPRESS(f) || + last_bytes != f->compress_threshold_bytes) { + + log_debug("Journal effective settings seal=%s keyed_hash=%s compress=%s compress_threshold_bytes=%s", + yes_no(JOURNAL_HEADER_SEALED(f->header)), yes_no(JOURNAL_HEADER_KEYED_HASH(f->header)), + yes_no(JOURNAL_FILE_COMPRESS(f)), FORMAT_BYTES(f->compress_threshold_bytes)); + last_seal = JOURNAL_HEADER_SEALED(f->header); + last_keyed_hash = JOURNAL_HEADER_KEYED_HASH(f->header); + last_compress = JOURNAL_FILE_COMPRESS(f); + last_bytes = f->compress_threshold_bytes; + } + } + + *ret = f; + return 0; + +fail: + if (f->cache_fd && mmap_cache_fd_got_sigbus(f->cache_fd)) + r = -EIO; + + (void) journal_file_close(f); + + if (newly_created && fd < 0) + (void) unlink(fname); + + return r; +} + +int journal_file_archive(JournalFile *f, char **ret_previous_path) { + _cleanup_free_ char *p = NULL; + + assert(f); + + if (!journal_file_writable(f)) + return -EINVAL; + + /* Is this a journal file that was passed to us as fd? If so, we synthesized a path name for it, and we refuse + * rotation, since we don't know the actual path, and couldn't rename the file hence. */ + if (path_startswith(f->path, "/proc/self/fd")) + return -EINVAL; + + if (!endswith(f->path, ".journal")) + return -EINVAL; + + if (asprintf(&p, "%.*s@" SD_ID128_FORMAT_STR "-%016"PRIx64"-%016"PRIx64".journal", + (int) strlen(f->path) - 8, f->path, + SD_ID128_FORMAT_VAL(f->header->seqnum_id), + le64toh(f->header->head_entry_seqnum), + le64toh(f->header->head_entry_realtime)) < 0) + return -ENOMEM; + + /* Try to rename the file to the archived version. If the file already was deleted, we'll get ENOENT, let's + * ignore that case. */ + if (rename(f->path, p) < 0 && errno != ENOENT) + return -errno; + + /* Sync the rename to disk */ + (void) fsync_directory_of_file(f->fd); + + if (ret_previous_path) + *ret_previous_path = f->path; + else + free(f->path); + + f->path = TAKE_PTR(p); + + /* Set as archive so offlining commits w/state=STATE_ARCHIVED. Previously we would set old_file->header->state + * to STATE_ARCHIVED directly here, but journal_file_set_offline() short-circuits when state != STATE_ONLINE, + * which would result in the rotated journal never getting fsync() called before closing. Now we simply queue + * the archive state by setting an archive bit, leaving the state as STATE_ONLINE so proper offlining + * occurs. */ + f->archive = true; + + return 0; +} + +int journal_file_dispose(int dir_fd, const char *fname) { + _cleanup_free_ char *p = NULL; + + assert(fname); + + /* Renames a journal file to *.journal~, i.e. to mark it as corrupted or otherwise uncleanly shutdown. Note that + * this is done without looking into the file or changing any of its contents. The idea is that this is called + * whenever something is suspicious and we want to move the file away and make clear that it is not accessed + * for writing anymore. */ + + if (!endswith(fname, ".journal")) + return -EINVAL; + + if (asprintf(&p, "%.*s@%016" PRIx64 "-%016" PRIx64 ".journal~", + (int) strlen(fname) - 8, fname, + now(CLOCK_REALTIME), + random_u64()) < 0) + return -ENOMEM; + + if (renameat(dir_fd, fname, dir_fd, p) < 0) + return -errno; + + return 0; +} + +int journal_file_copy_entry(JournalFile *from, JournalFile *to, Object *o, uint64_t p) { + _cleanup_free_ EntryItem *items_alloc = NULL; + EntryItem *items; + uint64_t n, m = 0, xor_hash = 0; + sd_id128_t boot_id; + dual_timestamp ts; + int r; + + assert(from); + assert(to); + assert(o); + assert(p > 0); + + if (!journal_file_writable(to)) + return -EPERM; + + ts = (dual_timestamp) { + .monotonic = le64toh(o->entry.monotonic), + .realtime = le64toh(o->entry.realtime), + }; + boot_id = o->entry.boot_id; + + n = journal_file_entry_n_items(from, o); + if (n == 0) + return 0; + + if (n < ALLOCA_MAX / sizeof(EntryItem) / 2) + items = newa(EntryItem, n); + else { + items_alloc = new(EntryItem, n); + if (!items_alloc) + return -ENOMEM; + + items = items_alloc; + } + + for (uint64_t i = 0; i < n; i++) { + uint64_t h, q; + void *data; + size_t l; + Object *u; + + q = journal_file_entry_item_object_offset(from, o, i); + r = journal_file_data_payload(from, NULL, q, NULL, 0, 0, &data, &l); + if (IN_SET(r, -EADDRNOTAVAIL, -EBADMSG)) { + log_debug_errno(r, "Entry item %"PRIu64" data object is bad, skipping over it: %m", i); + goto next; + } + if (r < 0) + return r; + assert(r > 0); + + if (l == 0) + return -EBADMSG; + + r = journal_file_append_data(to, data, l, &u, &h); + if (r < 0) + return r; + + if (JOURNAL_HEADER_KEYED_HASH(to->header)) + xor_hash ^= jenkins_hash64(data, l); + else + xor_hash ^= le64toh(u->data.hash); + + items[m++] = (EntryItem) { + .object_offset = h, + .hash = le64toh(u->data.hash), + }; + + next: + /* The above journal_file_data_payload() may clear or overwrite cached object. Hence, we need + * to re-read the object from the cache. */ + r = journal_file_move_to_object(from, OBJECT_ENTRY, p, &o); + if (r < 0) + return r; + } + + if (m == 0) + return 0; + + r = journal_file_append_entry_internal(to, &ts, &boot_id, xor_hash, items, m, NULL, NULL, NULL); + + if (mmap_cache_fd_got_sigbus(to->cache_fd)) + return -EIO; + + return r; +} + +void journal_reset_metrics(JournalMetrics *m) { + assert(m); + + /* Set everything to "pick automatic values". */ + + *m = (JournalMetrics) { + .min_use = UINT64_MAX, + .max_use = UINT64_MAX, + .min_size = UINT64_MAX, + .max_size = UINT64_MAX, + .keep_free = UINT64_MAX, + .n_max_files = UINT64_MAX, + }; +} + +int journal_file_get_cutoff_realtime_usec(JournalFile *f, usec_t *ret_from, usec_t *ret_to) { + assert(f); + assert(f->header); + assert(ret_from || ret_to); + + if (ret_from) { + if (f->header->head_entry_realtime == 0) + return -ENOENT; + + *ret_from = le64toh(f->header->head_entry_realtime); + } + + if (ret_to) { + if (f->header->tail_entry_realtime == 0) + return -ENOENT; + + *ret_to = le64toh(f->header->tail_entry_realtime); + } + + return 1; +} + +int journal_file_get_cutoff_monotonic_usec(JournalFile *f, sd_id128_t boot_id, usec_t *ret_from, usec_t *ret_to) { + Object *o; + uint64_t p; + int r; + + assert(f); + assert(ret_from || ret_to); + + /* FIXME: fix return value assignment on success with 0. */ + + r = find_data_object_by_boot_id(f, boot_id, &o, &p); + if (r <= 0) + return r; + + if (le64toh(o->data.n_entries) <= 0) + return 0; + + if (ret_from) { + r = journal_file_move_to_object(f, OBJECT_ENTRY, le64toh(o->data.entry_offset), &o); + if (r < 0) + return r; + + *ret_from = le64toh(o->entry.monotonic); + } + + if (ret_to) { + r = journal_file_move_to_object(f, OBJECT_DATA, p, &o); + if (r < 0) + return r; + + r = generic_array_get_plus_one(f, + le64toh(o->data.entry_offset), + le64toh(o->data.entry_array_offset), + le64toh(o->data.n_entries) - 1, + DIRECTION_UP, + &o, NULL); + if (r <= 0) + return r; + + *ret_to = le64toh(o->entry.monotonic); + } + + return 1; +} + +bool journal_file_rotate_suggested(JournalFile *f, usec_t max_file_usec, int log_level) { + assert(f); + assert(f->header); + + /* If we gained new header fields we gained new features, + * hence suggest a rotation */ + if (le64toh(f->header->header_size) < sizeof(Header)) { + log_full(log_level, "%s uses an outdated header, suggesting rotation.", f->path); + return true; + } + + /* Let's check if the hash tables grew over a certain fill level (75%, borrowing this value from + * Java's hash table implementation), and if so suggest a rotation. To calculate the fill level we + * need the n_data field, which only exists in newer versions. */ + + if (JOURNAL_HEADER_CONTAINS(f->header, n_data)) + if (le64toh(f->header->n_data) * 4ULL > (le64toh(f->header->data_hash_table_size) / sizeof(HashItem)) * 3ULL) { + log_full(log_level, + "Data hash table of %s has a fill level at %.1f (%"PRIu64" of %"PRIu64" items, %llu file size, %"PRIu64" bytes per hash table item), suggesting rotation.", + f->path, + 100.0 * (double) le64toh(f->header->n_data) / ((double) (le64toh(f->header->data_hash_table_size) / sizeof(HashItem))), + le64toh(f->header->n_data), + le64toh(f->header->data_hash_table_size) / sizeof(HashItem), + (unsigned long long) f->last_stat.st_size, + f->last_stat.st_size / le64toh(f->header->n_data)); + return true; + } + + if (JOURNAL_HEADER_CONTAINS(f->header, n_fields)) + if (le64toh(f->header->n_fields) * 4ULL > (le64toh(f->header->field_hash_table_size) / sizeof(HashItem)) * 3ULL) { + log_full(log_level, + "Field hash table of %s has a fill level at %.1f (%"PRIu64" of %"PRIu64" items), suggesting rotation.", + f->path, + 100.0 * (double) le64toh(f->header->n_fields) / ((double) (le64toh(f->header->field_hash_table_size) / sizeof(HashItem))), + le64toh(f->header->n_fields), + le64toh(f->header->field_hash_table_size) / sizeof(HashItem)); + return true; + } + + /* If there are too many hash collisions somebody is most likely playing games with us. Hence, if our + * longest chain is longer than some threshold, let's suggest rotation. */ + if (JOURNAL_HEADER_CONTAINS(f->header, data_hash_chain_depth) && + le64toh(f->header->data_hash_chain_depth) > HASH_CHAIN_DEPTH_MAX) { + log_full(log_level, + "Data hash table of %s has deepest hash chain of length %" PRIu64 ", suggesting rotation.", + f->path, le64toh(f->header->data_hash_chain_depth)); + return true; + } + + if (JOURNAL_HEADER_CONTAINS(f->header, field_hash_chain_depth) && + le64toh(f->header->field_hash_chain_depth) > HASH_CHAIN_DEPTH_MAX) { + log_full(log_level, + "Field hash table of %s has deepest hash chain of length at %" PRIu64 ", suggesting rotation.", + f->path, le64toh(f->header->field_hash_chain_depth)); + return true; + } + + /* Are the data objects properly indexed by field objects? */ + if (JOURNAL_HEADER_CONTAINS(f->header, n_data) && + JOURNAL_HEADER_CONTAINS(f->header, n_fields) && + le64toh(f->header->n_data) > 0 && + le64toh(f->header->n_fields) == 0) { + log_full(log_level, + "Data objects of %s are not indexed by field objects, suggesting rotation.", + f->path); + return true; + } + + if (max_file_usec > 0) { + usec_t t, h; + + h = le64toh(f->header->head_entry_realtime); + t = now(CLOCK_REALTIME); + + if (h > 0 && t > h + max_file_usec) { + log_full(log_level, + "Oldest entry in %s is older than the configured file retention duration (%s), suggesting rotation.", + f->path, FORMAT_TIMESPAN(max_file_usec, USEC_PER_SEC)); + return true; + } + } + + return false; +} + +static const char * const journal_object_type_table[] = { + [OBJECT_UNUSED] = "unused", + [OBJECT_DATA] = "data", + [OBJECT_FIELD] = "field", + [OBJECT_ENTRY] = "entry", + [OBJECT_DATA_HASH_TABLE] = "data hash table", + [OBJECT_FIELD_HASH_TABLE] = "field hash table", + [OBJECT_ENTRY_ARRAY] = "entry array", + [OBJECT_TAG] = "tag", +}; + +DEFINE_STRING_TABLE_LOOKUP_TO_STRING(journal_object_type, ObjectType); |