summaryrefslogtreecommitdiff
path: root/lib/sqfs/write_xattr.c
diff options
context:
space:
mode:
authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-08-31 16:59:50 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-08-31 17:17:23 +0200
commit2ac43d981859bda063e7067371c1cf246c7f81b0 (patch)
treeca289d2b708a60d13e300cc36ae47839389d26cf /lib/sqfs/write_xattr.c
parent9b3d958fb7c37855a63ed75707281c61dc1d44c4 (diff)
Split libsquashfs.a into low seperate libraries
The idea is to make libsquashfs.a independend of libfstree.a, so it becomes a general purpose squashfs manipulation library. All the high level glue code for libfstree.a and utilites that are overly specific with to tools are moved to a seperate librarby. This commit makes the first step by moving the stuff with dependencies on libfstree to a seperate library. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/sqfs/write_xattr.c')
-rw-r--r--lib/sqfs/write_xattr.c279
1 files changed, 0 insertions, 279 deletions
diff --git a/lib/sqfs/write_xattr.c b/lib/sqfs/write_xattr.c
deleted file mode 100644
index 2263fbe..0000000
--- a/lib/sqfs/write_xattr.c
+++ /dev/null
@@ -1,279 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * write_xattr.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "meta_writer.h"
-#include "highlevel.h"
-#include "util.h"
-
-#include <assert.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-
-static int write_key(meta_writer_t *mw, const char *key, tree_xattr_t *xattr,
- bool value_is_ool)
-{
- sqfs_xattr_entry_t kent;
- int type;
-
- type = sqfs_get_xattr_prefix_id(key);
- if (type < 0) {
- fprintf(stderr, "unsupported xattr key '%s'\n", key);
- return -1;
- }
-
- key = strchr(key, '.');
- assert(key != NULL);
- ++key;
-
- if (value_is_ool)
- type |= SQUASHFS_XATTR_FLAG_OOL;
-
- kent.type = htole16(type);
- kent.size = htole16(strlen(key));
-
- if (meta_writer_append(mw, &kent, sizeof(kent)))
- return -1;
- if (meta_writer_append(mw, key, strlen(key)))
- return -1;
-
- xattr->size += sizeof(sqfs_xattr_entry_t) + strlen(key);
- return 0;
-}
-
-static int write_value(meta_writer_t *mw, const char *value,
- tree_xattr_t *xattr, uint64_t *value_ref_out)
-{
- sqfs_xattr_value_t vent;
- uint32_t offset;
- uint64_t block;
-
- meta_writer_get_position(mw, &block, &offset);
- *value_ref_out = (block << 16) | (offset & 0xFFFF);
-
- vent.size = htole32(strlen(value));
-
- if (meta_writer_append(mw, &vent, sizeof(vent)))
- return -1;
-
- if (meta_writer_append(mw, value, strlen(value)))
- return -1;
-
- xattr->size += sizeof(vent) + strlen(value);
- return 0;
-}
-
-static int write_value_ool(meta_writer_t *mw, uint64_t location,
- tree_xattr_t *xattr)
-{
- sqfs_xattr_value_t vent;
- uint64_t ref;
-
- vent.size = htole32(sizeof(location));
- if (meta_writer_append(mw, &vent, sizeof(vent)))
- return -1;
-
- ref = htole64(location);
- if (meta_writer_append(mw, &ref, sizeof(ref)))
- return -1;
-
- xattr->size += sizeof(vent) + sizeof(ref);
- return 0;
-}
-
-static bool should_store_ool(fstree_t *fs, const char *value, size_t index)
-{
- size_t refcount;
-
- refcount = str_table_get_ref_count(&fs->xattr_values, index);
- 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 if:
- refcount * len > len + (refcount - 1) * 8
- => refcount * len - len > (refcount - 1) * 8
- => (refcount - 1) * len > (refcount - 1) * 8
- => len > 8
-
- Note that this only holds iff refcount - 1 != 0, i.e. refcount > 1,
- otherwise we would be dividing by 0 in the 3rd step.
- */
- return strlen(value) > sizeof(uint64_t);
-}
-
-static int write_kv_pairs(fstree_t *fs, meta_writer_t *mw, tree_xattr_t *xattr,
- uint64_t *ool_locations)
-{
- uint32_t key_idx, val_idx;
- const char *key, *value;
- uint64_t ref;
- size_t i;
-
- for (i = 0; i < xattr->num_attr; ++i) {
- key_idx = xattr->attr[i].key_index;
- val_idx = xattr->attr[i].value_index;
-
- key = str_table_get_string(&fs->xattr_keys, key_idx);
- value = str_table_get_string(&fs->xattr_values, val_idx);
-
- if (ool_locations[val_idx] == 0xFFFFFFFFFFFFFFFF) {
- if (write_key(mw, key, xattr, false))
- return -1;
-
- if (write_value(mw, value, xattr, &ref))
- return -1;
-
- if (should_store_ool(fs, value, val_idx))
- ool_locations[val_idx] = ref;
- } else {
- if (write_key(mw, key, xattr, true))
- return -1;
-
- if (write_value_ool(mw, ool_locations[val_idx], xattr))
- return -1;
- }
- }
-
- return 0;
-}
-
-static uint64_t *create_ool_locations_table(fstree_t *fs)
-{
- uint64_t *table;
- size_t i;
-
- table = alloc_array(sizeof(uint64_t), fs->xattr_values.num_strings);
-
- if (table == NULL) {
- perror("allocating Xattr OOL locations table");
- return NULL;
- }
-
- for (i = 0; i < fs->xattr_values.num_strings; ++i) {
- table[i] = 0xFFFFFFFFFFFFFFFFUL;
- }
-
- return table;
-}
-
-int write_xattr(int outfd, fstree_t *fs, sqfs_super_t *super,
- compressor_t *cmp)
-{
- uint64_t kv_start, id_start, block, *tbl, *ool_locations;
- size_t i = 0, count = 0, blocks;
- sqfs_xattr_id_table_t idtbl;
- sqfs_xattr_id_t id_ent;
- meta_writer_t *mw;
- tree_xattr_t *it;
- uint32_t offset;
-
- if (fs->xattr == NULL)
- return 0;
-
- ool_locations = create_ool_locations_table(fs);
- if (ool_locations == NULL)
- return -1;
-
- mw = meta_writer_create(outfd, cmp, false);
- if (mw == NULL)
- goto fail_ool;
-
- /* write xattr key-value pairs */
- kv_start = super->bytes_used;
-
- for (it = fs->xattr; it != NULL; it = it->next) {
- meta_writer_get_position(mw, &it->block, &it->offset);
- it->size = 0;
-
- if (write_kv_pairs(fs, mw, it, ool_locations))
- goto fail_mw;
-
- ++count;
- }
-
- if (meta_writer_flush(mw))
- goto fail_mw;
-
- meta_writer_get_position(mw, &block, &offset);
- meta_writer_reset(mw);
-
- super->bytes_used += block;
-
- /* allocate location table */
- blocks = (count * sizeof(id_ent)) / SQFS_META_BLOCK_SIZE;
-
- if ((count * sizeof(id_ent)) % SQFS_META_BLOCK_SIZE)
- ++blocks;
-
- tbl = alloc_array(sizeof(uint64_t), blocks);
-
- if (tbl == NULL) {
- perror("generating xattr ID table");
- goto fail_mw;
- }
-
- /* write ID table referring to key value pairs, record offsets */
- id_start = 0;
- tbl[i++] = htole64(super->bytes_used);
-
- for (it = fs->xattr; it != NULL; it = it->next) {
- id_ent.xattr = htole64((it->block << 16) | it->offset);
- id_ent.count = htole32(it->num_attr);
- id_ent.size = htole32(it->size);
-
- if (meta_writer_append(mw, &id_ent, sizeof(id_ent)))
- goto fail_tbl;
-
- meta_writer_get_position(mw, &block, &offset);
-
- if (block != id_start) {
- id_start = block;
- tbl[i++] = htole64(super->bytes_used + id_start);
- }
- }
-
- if (meta_writer_flush(mw))
- goto fail_tbl;
-
- meta_writer_get_position(mw, &block, &offset);
- super->bytes_used += block;
-
- /* write offset table */
- idtbl.xattr_table_start = htole64(kv_start);
- idtbl.xattr_ids = htole32(count);
- idtbl.unused = 0;
-
- if (write_data("writing xattr ID table", outfd, &idtbl, sizeof(idtbl)))
- goto fail_tbl;
-
- if (write_data("writing xattr ID table",
- outfd, tbl, sizeof(tbl[0]) * blocks)) {
- goto fail_tbl;
- }
-
- super->xattr_id_table_start = super->bytes_used;
- super->bytes_used += sizeof(idtbl) + sizeof(tbl[0]) * blocks;
- super->flags &= ~SQFS_FLAG_NO_XATTRS;
-
- free(tbl);
- meta_writer_destroy(mw);
- free(ool_locations);
- return 0;
-fail_tbl:
- free(tbl);
-fail_mw:
- meta_writer_destroy(mw);
-fail_ool:
- free(ool_locations);
- return -1;
-}