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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-09-28 18:52:54 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-09-28 20:27:19 +0200
commitd1189724303fe1794ff65689b5c4fc402fa2ad3b (patch)
tree772859c249fd80e3c5d14b842c2b4ea3bc26a606 /lib
parent0bd27cbaec56d71b2525c2b37ae209396c65d45b (diff)
Implement flush function that generates all the tables
Mostly straight copy-pasta from the sqfshelper code, except it doesn't use the fstree functions. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib')
-rw-r--r--lib/sqfs/xattr_writer.c306
1 files changed, 301 insertions, 5 deletions
diff --git a/lib/sqfs/xattr_writer.c b/lib/sqfs/xattr_writer.c
index 7643d49..318c613 100644
--- a/lib/sqfs/xattr_writer.c
+++ b/lib/sqfs/xattr_writer.c
@@ -20,6 +20,7 @@
#include <stdlib.h>
#include <string.h>
+#include <assert.h>
#define XATTR_KEY_BUCKETS 31
@@ -92,6 +93,9 @@ typedef struct kv_block_desc_t {
struct kv_block_desc_t *next;
size_t start;
size_t count;
+
+ uint64_t start_ref;
+ size_t size_bytes;
} kv_block_desc_t;
struct sqfs_xattr_writer_t {
@@ -290,12 +294,304 @@ int sqfs_xattr_writer_end(sqfs_xattr_writer_t *xwr, sqfs_u32 *out)
/*****************************************************************************/
+static sqfs_s32 write_key(sqfs_meta_writer_t *mw, const char *key,
+ bool value_is_ool)
+{
+ sqfs_xattr_entry_t kent;
+ int type, err;
+ size_t len;
+
+ type = sqfs_get_xattr_prefix_id(key);
+ assert(type >= 0);
+
+ key = strchr(key, '.');
+ assert(key != NULL);
+ ++key;
+ len = strlen(key);
+
+ if (value_is_ool)
+ type |= SQFS_XATTR_FLAG_OOL;
+
+ memset(&kent, 0, sizeof(kent));
+ kent.type = htole16(type);
+ kent.size = htole16(len);
+
+ err = sqfs_meta_writer_append(mw, &kent, sizeof(kent));
+ if (err)
+ return err;
+
+ err = sqfs_meta_writer_append(mw, key, len);
+ if (err)
+ return err;
+
+ return sizeof(kent) + len;
+}
+
+static sqfs_s32 write_value(sqfs_meta_writer_t *mw, const char *value_str,
+ sqfs_u64 *value_ref_out)
+{
+ sqfs_xattr_value_t vent;
+ sqfs_u32 offset;
+ sqfs_u64 block;
+ size_t size;
+ void *value;
+ int err;
+
+ value = from_base32(value_str, &size);
+ if (value == NULL)
+ return SQFS_ERROR_ALLOC;
+
+ memset(&vent, 0, sizeof(vent));
+ vent.size = htole32(size);
+
+ sqfs_meta_writer_get_position(mw, &block, &offset);
+ *value_ref_out = (block << 16) | (offset & 0xFFFF);
+
+ err = sqfs_meta_writer_append(mw, &vent, sizeof(vent));
+ if (err)
+ goto fail;
+
+ err = sqfs_meta_writer_append(mw, value, size);
+ if (err)
+ goto fail;
+
+ return sizeof(vent) + size;
+fail:
+ free(value);
+ return err;
+}
+
+static sqfs_s32 write_value_ool(sqfs_meta_writer_t *mw, sqfs_u64 location)
+{
+ sqfs_xattr_value_t vent;
+ sqfs_u64 ref;
+ int err;
+
+ memset(&vent, 0, sizeof(vent));
+ vent.size = htole32(sizeof(location));
+ ref = htole64(location);
+
+ err = sqfs_meta_writer_append(mw, &vent, sizeof(vent));
+ if (err)
+ return err;
+
+ err = sqfs_meta_writer_append(mw, &ref, sizeof(ref));
+ if (err)
+ return err;
+
+ return sizeof(vent) + sizeof(ref);
+}
+
+static bool should_store_ool(const char *val_str, size_t refcount)
+{
+ if (refcount < 2)
+ return false;
+
+ /*
+ Storing in line needs this many bytes: refcount * len
+
+ Storing out-of-line needs this many: len + (refcount - 1) * 8
+
+ Out-of-line prefereable iff refcount > 1 and:
+ refcount * len > len + (refcount - 1) * 8
+ => refcount * len - len > (refcount - 1) * 8
+ => (refcount - 1) * len > (refcount - 1) * 8
+ => len > 8
+ */
+ return (strlen(val_str) / 2) > sizeof(sqfs_u64);
+}
+
+static int write_block_pairs(sqfs_xattr_writer_t *xwr, sqfs_meta_writer_t *mw,
+ kv_block_desc_t *blk, sqfs_u64 *ool_locations)
+{
+ sqfs_u32 key_idx, val_idx;
+ const char *key_str, *value_str;
+ sqfs_s32 diff, total = 0;
+ size_t i, refcount;
+ sqfs_u64 ref;
+
+ for (i = 0; i < blk->count; ++i) {
+ key_idx = GET_KEY(xwr->kv_pairs[blk->start + i]);
+ val_idx = GET_VALUE(xwr->kv_pairs[blk->start + i]);
+
+ key_str = str_table_get_string(&xwr->keys, key_idx);
+ value_str = str_table_get_string(&xwr->values, val_idx);
+
+ if (ool_locations[val_idx] == 0xFFFFFFFFFFFFFFFFUL) {
+ diff = write_key(mw, key_str, false);
+ if (diff < 0)
+ return diff;
+ total += diff;
+
+ diff = write_value(mw, value_str, &ref);
+ if (diff < 0)
+ return diff;
+ total += diff;
+
+ refcount = str_table_get_ref_count(&xwr->values,
+ val_idx);
+
+ if (should_store_ool(value_str, refcount))
+ ool_locations[val_idx] = ref;
+ } else {
+ diff = write_key(mw, key_str, true);
+ if (diff < 0)
+ return diff;
+ total += diff;
+
+ diff = write_value_ool(mw, ool_locations[val_idx]);
+ if (diff < 0)
+ return diff;
+ total += diff;
+ }
+ }
+
+ return total;
+}
+
+static int write_kv_pairs(sqfs_xattr_writer_t *xwr, sqfs_meta_writer_t *mw)
+{
+ sqfs_u64 block, *ool_locations;
+ kv_block_desc_t *blk;
+ sqfs_u32 offset;
+ sqfs_s32 size;
+ size_t i;
+
+ ool_locations = alloc_array(sizeof(ool_locations[0]),
+ xwr->values.num_strings);
+ if (ool_locations == NULL)
+ return SQFS_ERROR_ALLOC;
+
+ for (i = 0; i < xwr->values.num_strings; ++i)
+ ool_locations[i] = 0xFFFFFFFFFFFFFFFFUL;
+
+ for (blk = xwr->kv_blocks; blk != NULL; blk = blk->next) {
+ sqfs_meta_writer_get_position(mw, &block, &offset);
+ blk->start_ref = (block << 16) | (offset & 0xFFFF);
+
+ size = write_block_pairs(xwr, mw, blk, ool_locations);
+ if (size < 0) {
+ free(ool_locations);
+ return size;
+ }
+
+ blk->size_bytes = size;
+ }
+
+ free(ool_locations);
+ return sqfs_meta_writer_flush(mw);
+}
+
+static int write_id_table(sqfs_xattr_writer_t *xwr, sqfs_meta_writer_t *mw,
+ sqfs_u64 *locations)
+{
+ sqfs_xattr_id_t id_ent;
+ kv_block_desc_t *blk;
+ sqfs_u32 offset;
+ sqfs_u64 block;
+ size_t i = 0;
+ int err;
+
+ locations[i++] = 0;
+
+ for (blk = xwr->kv_blocks; blk != NULL; blk = blk->next) {
+ memset(&id_ent, 0, sizeof(id_ent));
+ id_ent.xattr = htole64(blk->start_ref);
+ id_ent.count = htole32(blk->count);
+ id_ent.size = htole32(blk->size_bytes);
+
+ err = sqfs_meta_writer_append(mw, &id_ent, sizeof(id_ent));
+ if (err)
+ return err;
+
+ sqfs_meta_writer_get_position(mw, &block, &offset);
+ if (block != locations[i - 1])
+ locations[i++] = block;
+ }
+
+ return sqfs_meta_writer_flush(mw);
+}
+
+static int write_location_table(sqfs_xattr_writer_t *xwr, uint64_t kv_start,
+ sqfs_file_t *file, const sqfs_super_t *super,
+ sqfs_u64 *locations, size_t loc_count)
+{
+ sqfs_xattr_id_table_t idtbl;
+ int err;
+
+ memset(&idtbl, 0, sizeof(idtbl));
+ idtbl.xattr_table_start = htole64(kv_start);
+ idtbl.xattr_ids = htole32(xwr->num_blocks);
+
+ err = file->write_at(file, super->xattr_id_table_start,
+ &idtbl, sizeof(idtbl));
+ if (err)
+ return err;
+
+ return file->write_at(file, super->xattr_id_table_start + sizeof(idtbl),
+ locations, sizeof(locations[0]) * loc_count);
+}
+
+static int alloc_location_table(sqfs_xattr_writer_t *xwr, sqfs_u64 **tbl_out,
+ size_t *szout)
+{
+ sqfs_u64 *locations;
+ size_t size, count;
+
+ if (SZ_MUL_OV(xwr->num_blocks, sizeof(sqfs_xattr_id_t), &size))
+ return SQFS_ERROR_OVERFLOW;
+
+ count = size / SQFS_META_BLOCK_SIZE;
+ if (size % SQFS_META_BLOCK_SIZE)
+ ++count;
+
+ locations = alloc_array(sizeof(sqfs_u64), count);
+ if (locations == NULL)
+ return SQFS_ERROR_ALLOC;
+
+ *tbl_out = locations;
+ *szout = count;
+ return 0;
+}
+
int sqfs_xattr_writer_flush(sqfs_xattr_writer_t *xwr, sqfs_file_t *file,
sqfs_super_t *super, sqfs_compressor_t *cmp)
{
- (void)xwr;
- (void)file;
- (void)super;
- (void)cmp;
- return 0;
+ sqfs_u64 *locations = NULL, kv_start, id_start;
+ sqfs_meta_writer_t *mw;
+ size_t i, count;
+ int err;
+
+ mw = sqfs_meta_writer_create(file, cmp, 0);
+ if (mw == NULL)
+ return SQFS_ERROR_ALLOC;
+
+ kv_start = file->get_size(file);
+ err = write_kv_pairs(xwr, mw);
+ if (err)
+ goto out;
+
+ sqfs_meta_writer_reset(mw);
+
+ id_start = file->get_size(file);
+ err = alloc_location_table(xwr, &locations, &count);
+ if (err)
+ goto out;
+
+ err = write_id_table(xwr, mw, locations);
+ if (err)
+ goto out;
+
+ super->xattr_id_table_start = file->get_size(file);
+ super->flags &= ~SQFS_FLAG_NO_XATTRS;
+
+ for (i = 0; i < count; ++i)
+ locations[i] = htole64(locations[i] + id_start);
+
+ err = write_location_table(xwr, kv_start, file, super,
+ locations, count);
+out:
+ free(locations);
+ sqfs_meta_writer_destroy(mw);
+ return err;
}