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/* SPDX-License-Identifier: GPL-3.0-or-later */
#include "meta_writer.h"
#include "highlevel.h"
#include "util.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
static const struct {
const char *prefix;
E_SQFS_XATTR_TYPE type;
} xattr_types[] = {
{ "user.", SQUASHFS_XATTR_USER },
{ "trusted.", SQUASHFS_XATTR_TRUSTED },
{ "security.", SQUASHFS_XATTR_SECURITY },
};
static int get_prefix(const char *key)
{
size_t i, len;
for (i = 0; i < sizeof(xattr_types) / sizeof(xattr_types[0]); ++i) {
len = strlen(xattr_types[i].prefix);
if (strncmp(key, xattr_types[i].prefix, len) == 0 &&
strlen(key) > len) {
return xattr_types[i].type;
}
}
return -1;
}
bool sqfs_has_xattr(const char *key)
{
return get_prefix(key) >= 0;
}
static int write_pair(meta_writer_t *mw, const char *key, const char *value)
{
sqfs_xattr_entry_t kent;
sqfs_xattr_value_t vent;
int type;
type = get_prefix(key);
if (type < 0) {
fprintf(stderr, "unsupported xattr key '%s'\n", key);
return -1;
}
key = strchr(key, '.');
assert(key != NULL);
++key;
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;
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;
return 0;
}
static int write_kv_pairs(fstree_t *fs, meta_writer_t *mw, tree_xattr_t *xattr)
{
uint32_t key_idx, val_idx;
const char *key, *value;
size_t i;
for (i = 0; i < xattr->num_attr; ++i) {
key_idx = (xattr->ref[i] >> 32) & 0xFFFFFFFF;
val_idx = xattr->ref[i] & 0xFFFFFFFF;
key = str_table_get_string(&fs->xattr_keys, key_idx);
value = str_table_get_string(&fs->xattr_values, val_idx);
if (write_pair(mw, key, value))
return -1;
xattr->size += sizeof(sqfs_xattr_entry_t) + strlen(key);
xattr->size += sizeof(sqfs_xattr_value_t) + strlen(value);
}
return 0;
}
int write_xattr(int outfd, fstree_t *fs, sqfs_super_t *super,
compressor_t *cmp)
{
uint64_t kv_start, id_start, block, *tbl;
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;
ssize_t ret;
if (fs->xattr == NULL)
return 0;
mw = meta_writer_create(outfd, cmp);
if (mw == NULL)
return -1;
/* 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))
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 = calloc(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;
ret = write_retry(outfd, &idtbl, sizeof(idtbl));
if (ret < 0)
goto fail_wr;
if ((size_t)ret < sizeof(idtbl))
goto fail_trunc;
ret = write_retry(outfd, tbl, sizeof(tbl[0]) * blocks);
if (ret < 0)
goto fail_wr;
if ((size_t)ret < sizeof(tbl[0]) * blocks)
goto fail_trunc;
super->xattr_id_table_start = super->bytes_used;
super->bytes_used += sizeof(idtbl) + sizeof(tbl[0]) * blocks;
free(tbl);
meta_writer_destroy(mw);
return 0;
fail_wr:
perror("writing xattr ID table");
goto fail_tbl;
fail_trunc:
fputs("writing xattr ID table: truncated write\n", stderr);
goto fail_tbl;
fail_tbl:
free(tbl);
fail_mw:
meta_writer_destroy(mw);
return -1;
}
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