journal: verify structural consistency

This commit is contained in:
Lennart Poettering 2012-08-16 17:09:53 +02:00
parent f9fffc31cd
commit 86adf873be
2 changed files with 396 additions and 51 deletions

View file

@ -47,12 +47,12 @@ typedef struct FSPRGHeader FSPRGHeader;
/* Object types */
enum {
OBJECT_UNUSED,
OBJECT_DATA,
OBJECT_DATA, /* !!! */
OBJECT_FIELD,
OBJECT_ENTRY,
OBJECT_DATA_HASH_TABLE,
OBJECT_FIELD_HASH_TABLE,
OBJECT_ENTRY_ARRAY,
OBJECT_ENTRY_ARRAY, /* !!! */
OBJECT_TAG,
_OBJECT_TYPE_MAX
};

View file

@ -34,10 +34,11 @@
/* FIXME:
*
* - follow all chains
* - check for unreferenced objects
* - verify FSPRG
* - Allow building without libgcrypt
* - check with sparse
* - 64bit conversions
* - verification should use MAP_PRIVATE
*
* */
@ -110,12 +111,18 @@ static int journal_file_object_verify(JournalFile *f, Object *o) {
if ((le64toh(o->object.size) - offsetof(HashTableObject, items)) % sizeof(HashItem) != 0)
return -EBADMSG;
if ((le64toh(o->object.size) - offsetof(HashTableObject, items)) / sizeof(HashItem) <= 0)
return -EBADMSG;
break;
case OBJECT_ENTRY_ARRAY:
if ((le64toh(o->object.size) - offsetof(EntryArrayObject, items)) % sizeof(le64_t) != 0)
return -EBADMSG;
if ((le64toh(o->object.size) - offsetof(EntryArrayObject, items)) / sizeof(le64_t) <= 0)
return -EBADMSG;
break;
case OBJECT_TAG:
@ -206,7 +213,7 @@ static int contains_uint64(MMapCache *m, int fd, uint64_t n, uint64_t p) {
c = (a + b) / 2;
r = mmap_cache_get(m, fd, PROT_READ, 0, c * sizeof(uint64_t), sizeof(uint64_t), (void **) &z);
r = mmap_cache_get(m, fd, PROT_READ|PROT_WRITE, 0, c * sizeof(uint64_t), sizeof(uint64_t), (void **) &z);
if (r < 0)
return r;
@ -222,6 +229,368 @@ static int contains_uint64(MMapCache *m, int fd, uint64_t n, uint64_t p) {
return 0;
}
static int entry_points_to_data(
JournalFile *f,
int entry_fd,
uint64_t n_entries,
uint64_t entry_p,
uint64_t data_p) {
int r;
uint64_t i, n, a;
Object *o;
bool found = false;
assert(f);
assert(entry_fd >= 0);
if (!contains_uint64(f->mmap, entry_fd, n_entries, entry_p)) {
log_error("Data object references invalid entry at %llu", (unsigned long long) data_p);
return -EBADMSG;
}
r = journal_file_move_to_object(f, OBJECT_ENTRY, entry_p, &o);
if (r < 0)
return r;
n = journal_file_entry_n_items(o);
for (i = 0; i < n; i++)
if (le64toh(o->entry.items[i].object_offset) == data_p) {
found = true;
break;
}
if (!found) {
log_error("Data object not referenced by linked entry at %llu", (unsigned long long) data_p);
return -EBADMSG;
}
/* Check if this entry is also in main entry array. Since the
* main entry array has already been verified we can rely on
* its consistency.*/
n = le64toh(f->header->n_entries);
a = le64toh(f->header->entry_array_offset);
i = 0;
while (i < n) {
uint64_t m, j;
r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o);
if (r < 0)
return r;
m = journal_file_entry_array_n_items(o);
for (j = 0; i < n && j < m; i++, j++)
if (le64toh(o->entry_array.items[j]) == entry_p)
return 0;
a = le64toh(o->entry_array.next_entry_array_offset);;
}
return 0;
}
static int verify_data(
JournalFile *f,
Object *o, uint64_t p,
int entry_fd, uint64_t n_entries,
int entry_array_fd, uint64_t n_entry_arrays) {
uint64_t i, n, a, last, q;
int r;
assert(f);
assert(o);
assert(entry_fd >= 0);
assert(entry_array_fd >= 0);
n = le64toh(o->data.n_entries);
a = le64toh(o->data.entry_array_offset);
/* We already checked this earlier */
assert(n > 0);
last = q = le64toh(o->data.entry_offset);
r = entry_points_to_data(f, entry_fd, n_entries, q, p);
if (r < 0)
return r;
while (i < n) {
uint64_t next, m, j;
if (a == 0) {
log_error("Array chain too short at %llu.", (unsigned long long) p);
return -EBADMSG;
}
if (!contains_uint64(f->mmap, entry_array_fd, n_entry_arrays, a)) {
log_error("Invalid array at %llu.", (unsigned long long) p);
return -EBADMSG;
}
r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o);
if (r < 0)
return r;
next = le64toh(o->entry_array.next_entry_array_offset);
if (next != 0 && next <= a) {
log_error("Array chain has cycle at %llu.", (unsigned long long) p);
return -EBADMSG;
}
m = journal_file_entry_array_n_items(o);
for (j = 0; i < n && j < m; i++, j++) {
q = le64toh(o->entry_array.items[j]);
if (q <= last) {
log_error("Data object's entry array not sorted at %llu.", (unsigned long long) p);
return -EBADMSG;
}
last = q;
r = entry_points_to_data(f, entry_fd, n_entries, q, p);
if (r < 0)
return r;
/* Pointer might have moved, reposition */
r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o);
if (r < 0)
return r;
}
a = next;
}
return 0;
}
static int verify_hash_table(
JournalFile *f,
int data_fd, uint64_t n_data,
int entry_fd, uint64_t n_entries,
int entry_array_fd, uint64_t n_entry_arrays,
usec_t *last_usec) {
uint64_t i, n;
int r;
assert(f);
assert(data_fd >= 0);
assert(entry_fd >= 0);
assert(entry_array_fd >= 0);
assert(last_usec);
n = le64toh(f->header->data_hash_table_size) / sizeof(HashItem);
for (i = 0; i < n; i++) {
uint64_t last = 0, p;
draw_progress(0xC000 + (0x3FFF * i / n), last_usec);
p = le64toh(f->data_hash_table[i].head_hash_offset);
while (p != 0) {
Object *o;
uint64_t next;
if (!contains_uint64(f->mmap, data_fd, n_data, p)) {
log_error("Invalid data object at hash entry %llu of %llu.",
(unsigned long long) i, (unsigned long long) n);
return -EBADMSG;
}
r = journal_file_move_to_object(f, OBJECT_DATA, p, &o);
if (r < 0)
return r;
next = le64toh(o->data.next_hash_offset);
if (next != 0 && next <= p) {
log_error("Hash chain has a cycle in hash entry %llu of %llu.",
(unsigned long long) i, (unsigned long long) n);
return -EBADMSG;
}
if (le64toh(o->data.hash) % n != i) {
log_error("Hash value mismatch in hash entry %llu of %llu.",
(unsigned long long) i, (unsigned long long) n);
return -EBADMSG;
}
r = verify_data(f, o, p, entry_fd, n_entries, entry_array_fd, n_entry_arrays);
if (r < 0)
return r;
last = p;
p = next;
}
if (last != le64toh(f->data_hash_table[i].tail_hash_offset)) {
log_error("Tail hash pointer mismatch in hash table.");
return -EBADMSG;
}
}
return 0;
}
static int data_object_in_hash_table(JournalFile *f, uint64_t hash, uint64_t p) {
uint64_t n, h, q;
int r;
assert(f);
n = le64toh(f->header->data_hash_table_size) / sizeof(HashItem);
h = hash % n;
q = le64toh(f->data_hash_table[h].head_hash_offset);
while (q != 0) {
Object *o;
if (p == q)
return 1;
r = journal_file_move_to_object(f, OBJECT_DATA, q, &o);
if (r < 0)
return r;
q = le64toh(o->data.next_hash_offset);
}
return 0;
}
static int verify_entry(
JournalFile *f,
Object *o, uint64_t p,
int data_fd, uint64_t n_data) {
uint64_t i, n;
int r;
assert(f);
assert(o);
assert(data_fd >= 0);
n = journal_file_entry_n_items(o);
for (i = 0; i < n; i++) {
uint64_t q, h;
Object *u;
q = le64toh(o->entry.items[i].object_offset);
h = le64toh(o->entry.items[i].hash);
if (!contains_uint64(f->mmap, data_fd, n_data, q)) {
log_error("Invalid data object at entry %llu.",
(unsigned long long) o);
return -EBADMSG;
}
r = journal_file_move_to_object(f, OBJECT_DATA, q, &u);
if (r < 0)
return r;
if (le64toh(u->data.hash) != h) {
log_error("Hash mismatch for data object at entry %llu.",
(unsigned long long) p);
return -EBADMSG;
}
r = data_object_in_hash_table(f, h, q);
if (r < 0)
return r;
if (r == 0) {
log_error("Data object missing from hash at entry %llu.",
(unsigned long long) p);
return -EBADMSG;
}
}
return 0;
}
static int verify_entry_array(
JournalFile *f,
int data_fd, uint64_t n_data,
int entry_fd, uint64_t n_entries,
int entry_array_fd, uint64_t n_entry_arrays,
usec_t *last_usec) {
uint64_t i = 0, a, n, last = 0;
int r;
assert(f);
assert(data_fd >= 0);
assert(entry_fd >= 0);
assert(entry_array_fd >= 0);
assert(last_usec);
n = le64toh(f->header->n_entries);
a = le64toh(f->header->entry_array_offset);
while (i < n) {
uint64_t next, m, j;
Object *o;
draw_progress(0x8000 + (0x3FFF * i / n), last_usec);
if (a == 0) {
log_error("Array chain too short at %llu of %llu.",
(unsigned long long) i, (unsigned long long) n);
return -EBADMSG;
}
if (!contains_uint64(f->mmap, entry_array_fd, n_entry_arrays, a)) {
log_error("Invalid array at %llu of %llu.",
(unsigned long long) i, (unsigned long long) n);
return -EBADMSG;
}
r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o);
if (r < 0)
return r;
next = le64toh(o->entry_array.next_entry_array_offset);
if (next != 0 && next <= a) {
log_error("Array chain has cycle at %llu of %llu.",
(unsigned long long) i, (unsigned long long) n);
return -EBADMSG;
}
m = journal_file_entry_array_n_items(o);
for (j = 0; i < n && j < m; i++, j++) {
uint64_t p;
p = le64toh(o->entry_array.items[j]);
if (p <= last) {
log_error("Entry array not sorted at %llu of %llu.",
(unsigned long long) i, (unsigned long long) n);
return -EBADMSG;
}
last = p;
if (!contains_uint64(f->mmap, entry_fd, n_entries, p)) {
log_error("Invalid array entry at %llu of %llu.",
(unsigned long long) i, (unsigned long long) n);
return -EBADMSG;
}
r = journal_file_move_to_object(f, OBJECT_ENTRY, p, &o);
if (r < 0)
return r;
r = verify_entry(f, o, p, data_fd, n_data);
if (r < 0)
return r;
/* Pointer might have moved, reposition */
r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &o);
if (r < 0)
return r;
}
a = next;
}
return 0;
}
int journal_file_verify(JournalFile *f, const char *key) {
int r;
Object *o;
@ -270,7 +639,7 @@ int journal_file_verify(JournalFile *f, const char *key) {
p = le64toh(f->header->header_size);
while (p != 0) {
draw_progress((0x7FFF * p) / le64toh(f->header->tail_object_offset), &last_usec);
draw_progress(0x7FFF * p / le64toh(f->header->tail_object_offset), &last_usec);
r = journal_file_move_to_object(f, -1, p, &o);
if (r < 0) {
@ -504,53 +873,29 @@ int journal_file_verify(JournalFile *f, const char *key) {
goto fail;
}
/* Second iteration: we go through all objects again, this
* time verify all pointers. */
/* Second iteration: we follow all objects referenced from the
* two entry points: the object hash table and the entry
* array. We also check that everything referenced (directly
* or indirectly) in the data hash table also exists in the
* entry array, and vice versa. Note that we do not care for
* unreferenced objects. We only care that everything that is
* referenced is consistent. */
p = le64toh(f->header->header_size);
while (p != 0) {
draw_progress(0x8000 + (0x7FFF * p) / le64toh(f->header->tail_object_offset), &last_usec);
r = verify_entry_array(f,
data_fd, n_data,
entry_fd, n_entries,
entry_array_fd, n_entry_arrays,
&last_usec);
if (r < 0)
goto fail;
r = journal_file_move_to_object(f, -1, p, &o);
if (r < 0) {
log_error("Invalid object at %llu", (unsigned long long) p);
goto fail;
}
if (o->object.type == OBJECT_ENTRY_ARRAY) {
uint64_t i = 0, n;
if (le64toh(o->entry_array.next_entry_array_offset) != 0 &&
!contains_uint64(f->mmap, entry_array_fd, n_entry_arrays, le64toh(o->entry_array.next_entry_array_offset))) {
log_error("Entry array chains up to invalid next array at %llu", (unsigned long long) p);
r = -EBADMSG;
goto fail;
}
n = journal_file_entry_array_n_items(o);
for (i = 0; i < n; i++) {
if (le64toh(o->entry_array.items[i]) != 0 &&
!contains_uint64(f->mmap, entry_fd, n_entries, le64toh(o->entry_array.items[i]))) {
log_error("Entry array points to invalid next array at %llu", (unsigned long long) p);
r = -EBADMSG;
goto fail;
}
}
}
r = journal_file_move_to_object(f, -1, p, &o);
if (r < 0) {
log_error("Invalid object at %llu", (unsigned long long) p);
goto fail;
}
if (p == le64toh(f->header->tail_object_offset))
p = 0;
else
p = p + ALIGN64(le64toh(o->object.size));
}
r = verify_hash_table(f,
data_fd, n_data,
entry_fd, n_entries,
entry_array_fd, n_entry_arrays,
&last_usec);
if (r < 0)
goto fail;
flush_progress();