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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2020-06-07 23:38:06 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2020-06-09 06:04:08 +0200
commit1f210bab667a540379243050b5ce3465086e1124 (patch)
tree2f3aafe42326cc47a6f5952d3e4bb980ce41e4a1 /lib/sqfs/xattr/xattr_writer_flush.c
parent04be64583149515f774bf01f03b1be6121649668 (diff)
Cleanup: split libsquashfs xattr writer code
This commit moves the libsquashfs xattr related code into a sub directory and splits the xattr writer code up into several files. No actual code is changed. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/sqfs/xattr/xattr_writer_flush.c')
-rw-r--r--lib/sqfs/xattr/xattr_writer_flush.c342
1 files changed, 342 insertions, 0 deletions
diff --git a/lib/sqfs/xattr/xattr_writer_flush.c b/lib/sqfs/xattr/xattr_writer_flush.c
new file mode 100644
index 0000000..9b3de30
--- /dev/null
+++ b/lib/sqfs/xattr/xattr_writer_flush.c
@@ -0,0 +1,342 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * xattr_writer_flush.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "xattr_writer.h"
+
+static const char *hexmap = "0123456789ABCDEF";
+
+static void *from_base32(const char *input, size_t *size_out)
+{
+ sqfs_u8 lo, hi, *out, *ptr;
+ size_t len;
+
+ len = strlen(input);
+ *size_out = len / 2;
+
+ out = malloc(*size_out);
+ if (out == NULL)
+ return NULL;
+
+ ptr = out;
+
+ while (*input != '\0') {
+ lo = strchr(hexmap, *(input++)) - hexmap;
+ hi = strchr(hexmap, *(input++)) - hexmap;
+
+ *(ptr++) = lo | (hi << 4);
+ }
+
+ return 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;
+
+ free(value);
+ 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, sqfs_u64 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)
+{
+ sqfs_u64 *locations = NULL, kv_start, id_start;
+ sqfs_meta_writer_t *mw;
+ size_t i, count;
+ int err;
+
+ if (xwr->num_pairs == 0 || xwr->num_blocks == 0) {
+ super->xattr_id_table_start = 0xFFFFFFFFFFFFFFFFUL;
+ super->flags |= SQFS_FLAG_NO_XATTRS;
+ return 0;
+ }
+
+ 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_destroy(mw);
+ return err;
+}