From 31d327c3780aecdb78304263f676ff89a8ea93d1 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Wed, 1 May 2019 16:55:08 +0200 Subject: unsquashfs: read ID table from file Signed-off-by: David Oberhollenzer --- lib/Makemodule.am | 3 +- lib/sqfs/id_table.c | 21 ----------- lib/sqfs/id_table_read.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++ lib/sqfs/id_table_write.c | 23 ++++++++++++ 4 files changed, 121 insertions(+), 22 deletions(-) create mode 100644 lib/sqfs/id_table_read.c create mode 100644 lib/sqfs/id_table_write.c (limited to 'lib') diff --git a/lib/Makemodule.am b/lib/Makemodule.am index 5cadf58..08b53e1 100644 --- a/lib/Makemodule.am +++ b/lib/Makemodule.am @@ -12,7 +12,8 @@ libsquashfs_a_SOURCES += lib/sqfs/meta_writer.c lib/sqfs/super.c libsquashfs_a_SOURCES += lib/sqfs/id_table.c include/id_table.h libsquashfs_a_SOURCES += lib/sqfs/table.c include/table.h libsquashfs_a_SOURCES += lib/sqfs/read_super.c lib/sqfs/meta_reader.c -libsquashfs_a_SOURCES += include/meta_reader.h +libsquashfs_a_SOURCES += include/meta_reader.h lib/sqfs/id_table_write.c +libsquashfs_a_SOURCES += lib/sqfs/id_table_read.c libutil_a_SOURCES = lib/util/canonicalize_name.c lib/util/write_retry.c libutil_a_SOURCES += lib/util/read_retry.c include/util.h diff --git a/lib/sqfs/id_table.c b/lib/sqfs/id_table.c index 4cc12c6..cd31360 100644 --- a/lib/sqfs/id_table.c +++ b/lib/sqfs/id_table.c @@ -1,6 +1,5 @@ /* SPDX-License-Identifier: GPL-3.0-or-later */ #include "id_table.h" -#include "table.h" #include #include @@ -51,23 +50,3 @@ int id_table_id_to_index(id_table_t *tbl, uint32_t id, uint16_t *out) tbl->ids[tbl->num_ids++] = id; return 0; } - -int id_table_write(id_table_t *tbl, int outfd, sqfs_super_t *super, - compressor_t *cmp) -{ - size_t i; - int ret; - - for (i = 0; i < tbl->num_ids; ++i) - tbl->ids[i] = htole32(tbl->ids[i]); - - super->id_count = tbl->num_ids; - - ret = sqfs_write_table(outfd, super, tbl->ids, sizeof(tbl->ids[0]), - tbl->num_ids, &super->id_table_start, cmp); - - for (i = 0; i < tbl->num_ids; ++i) - tbl->ids[i] = le32toh(tbl->ids[i]); - - return ret; -} diff --git a/lib/sqfs/id_table_read.c b/lib/sqfs/id_table_read.c new file mode 100644 index 0000000..b1305ff --- /dev/null +++ b/lib/sqfs/id_table_read.c @@ -0,0 +1,96 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +#include "meta_reader.h" +#include "id_table.h" +#include "table.h" +#include "util.h" + +#include +#include +#include + +int id_table_read(id_table_t *tbl, int fd, sqfs_super_t *super, + compressor_t *cmp) +{ + size_t i, block_count, count, diff; + uint64_t blocks[32]; + meta_reader_t *m; + uint32_t *ptr; + ssize_t ret; + + if (tbl->ids != NULL) { + free(tbl->ids); + tbl->num_ids = 0; + tbl->max_ids = 0; + tbl->ids = NULL; + } + + if (!super->id_count || super->id_table_start >= super->bytes_used) { + fputs("ID table missing from file system\n", stderr); + return -1; + } + + tbl->ids = malloc(super->id_count * sizeof(uint32_t)); + if (tbl->ids == NULL) { + perror("reading ID table"); + return -1; + } + + tbl->num_ids = super->id_count; + tbl->max_ids = super->id_count; + + if (lseek(fd, super->id_table_start, SEEK_SET) == (off_t)-1) + goto fail_seek; + + block_count = super->id_count / 2048; + if (super->id_count % 2048) + ++block_count; + + ret = read_retry(fd, blocks, sizeof(blocks[0]) * block_count); + if (ret < 0) + goto fail_rd; + + if ((size_t)ret < sizeof(blocks[0]) * block_count) + goto fail_trunc; + + for (i = 0; i < block_count; ++i) + blocks[i] = le64toh(blocks[i]); + + m = meta_reader_create(fd, cmp); + if (m == NULL) + return -1; + + count = super->id_count; + ptr = tbl->ids; + + for (i = 0; i < block_count && count > 0; ++i) { + diff = count < 2048 ? count : 2048; + + if (meta_reader_seek(m, blocks[i], 0)) + goto fail_meta; + + if (meta_reader_read(m, ptr, diff * sizeof(tbl->ids[0]))) + goto fail_meta; + + count -= diff; + ptr += diff; + } + + meta_reader_destroy(m); + + for (i = 0; i < tbl->num_ids; ++i) + tbl->ids[i] = le32toh(tbl->ids[i]); + + return 0; +fail_meta: + meta_reader_destroy(m); + return -1; +fail_trunc: + fputs("reading ID table: unexpected end of file\n", stderr); + return -1; +fail_rd: + perror("reading ID table"); + return -1; +fail_seek: + perror("seeking to ID table"); + return -1; +} diff --git a/lib/sqfs/id_table_write.c b/lib/sqfs/id_table_write.c new file mode 100644 index 0000000..490c2af --- /dev/null +++ b/lib/sqfs/id_table_write.c @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +#include "id_table.h" +#include "table.h" + +int id_table_write(id_table_t *tbl, int outfd, sqfs_super_t *super, + compressor_t *cmp) +{ + size_t i; + int ret; + + for (i = 0; i < tbl->num_ids; ++i) + tbl->ids[i] = htole32(tbl->ids[i]); + + super->id_count = tbl->num_ids; + + ret = sqfs_write_table(outfd, super, tbl->ids, sizeof(tbl->ids[0]), + tbl->num_ids, &super->id_table_start, cmp); + + for (i = 0; i < tbl->num_ids; ++i) + tbl->ids[i] = le32toh(tbl->ids[i]); + + return ret; +} -- cgit v1.2.3