From f780c9542d2c96cb0ae00a8de8d67b9a8fd278cd Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Tue, 3 Sep 2019 12:54:15 +0200 Subject: Add fstree independend directory writer to libsquashfs.so This commit adds a directory writer to libsquashfs that wrapps a meta data writer and provides a higher-level interface for writing directory entries. Under the hood it enforces the rules that squashfs insists upon. Signed-off-by: David Oberhollenzer --- lib/Makemodule.am | 3 +- lib/sqfs/dir_writer.c | 287 ++++++++++++++++++++++++++++++++++++++ lib/sqfshelper/serialize_fstree.c | 9 +- lib/sqfshelper/write_dir.c | 144 ------------------- lib/sqfshelper/write_inode.c | 59 ++++---- 5 files changed, 325 insertions(+), 177 deletions(-) create mode 100644 lib/sqfs/dir_writer.c delete mode 100644 lib/sqfshelper/write_dir.c (limited to 'lib') diff --git a/lib/Makemodule.am b/lib/Makemodule.am index a5db913..1f709c1 100644 --- a/lib/Makemodule.am +++ b/lib/Makemodule.am @@ -24,7 +24,6 @@ libsqfshelper_a_SOURCES += lib/sqfshelper/serialize_fstree.c libsqfshelper_a_SOURCES += lib/sqfshelper/statistics.c libsqfshelper_a_SOURCES += lib/sqfshelper/tree_node_from_inode.c libsqfshelper_a_SOURCES += lib/sqfshelper/sqfs_reader.c -libsqfshelper_a_SOURCES += lib/sqfshelper/write_dir.c libsqfshelper_a_SOURCES += lib/sqfshelper/write_inode.c libsqfshelper_a_SOURCES += lib/sqfshelper/write_export_table.c libsqfshelper_a_SOURCES += lib/sqfshelper/print_version.c @@ -50,7 +49,7 @@ libsquashfs_la_SOURCES += include/sqfs/super.h include/sqfs/inode.h libsquashfs_la_SOURCES += include/sqfs/dir.h include/sqfs/xattr.h libsquashfs_la_SOURCES += include/sqfs/table.h libsquashfs_la_SOURCES += lib/sqfs/meta_writer.c lib/sqfs/super.c -libsquashfs_la_SOURCES += lib/sqfs/id_table.c +libsquashfs_la_SOURCES += lib/sqfs/id_table.c lib/sqfs/dir_writer.c libsquashfs_la_SOURCES += lib/sqfs/write_table.c include/highlevel.h libsquashfs_la_SOURCES += lib/sqfs/read_super.c lib/sqfs/meta_reader.c libsquashfs_la_SOURCES += lib/sqfs/read_inode.c diff --git a/lib/sqfs/dir_writer.c b/lib/sqfs/dir_writer.c new file mode 100644 index 0000000..3ef3bc7 --- /dev/null +++ b/lib/sqfs/dir_writer.c @@ -0,0 +1,287 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * dir_writer.c + * + * Copyright (C) 2019 David Oberhollenzer + */ +#include "config.h" + +#include "sqfs/inode.h" +#include "sqfs/dir.h" +#include "util.h" + +#include +#include +#include +#include +#include +#include + +typedef struct dir_entry_t { + struct dir_entry_t *next; + uint64_t inode_ref; + uint32_t inode_num; + uint16_t type; + size_t name_len; + char name[]; +} dir_entry_t; + +typedef struct index_ent_t { + struct index_ent_t *next; + dir_entry_t *ent; + uint64_t block; + uint32_t index; +} index_ent_t; + +struct sqfs_dir_writer_t { + dir_entry_t *list; + dir_entry_t *list_end; + + index_ent_t *idx; + index_ent_t *idx_end; + + uint64_t dir_ref; + size_t dir_size; + size_t idx_size; + meta_writer_t *dm; +}; + +static int get_type(mode_t mode) +{ + switch (mode & S_IFMT) { + case S_IFSOCK: return SQFS_INODE_SOCKET; + case S_IFIFO: return SQFS_INODE_FIFO; + case S_IFLNK: return SQFS_INODE_SLINK; + case S_IFBLK: return SQFS_INODE_BDEV; + case S_IFCHR: return SQFS_INODE_CDEV; + case S_IFDIR: return SQFS_INODE_DIR; + case S_IFREG: return SQFS_INODE_FILE; + default: + assert(0); + } +} + +static void writer_reset(sqfs_dir_writer_t *writer) +{ + dir_entry_t *ent; + index_ent_t *idx; + + while (writer->idx != NULL) { + idx = writer->idx; + writer->idx = idx->next; + free(idx); + } + + while (writer->list != NULL) { + ent = writer->list; + writer->list = ent->next; + free(ent); + } + + writer->list_end = NULL; + writer->idx_end = NULL; + writer->dir_ref = 0; + writer->dir_size = 0; + writer->idx_size = 0; +} + +sqfs_dir_writer_t *sqfs_dir_writer_create(meta_writer_t *dm) +{ + sqfs_dir_writer_t *writer = calloc(1, sizeof(*writer)); + + if (writer == NULL) { + perror("creating directory writer"); + return NULL; + } + + writer->dm = dm; + return writer; +} + +void sqfs_dir_writer_destroy(sqfs_dir_writer_t *writer) +{ + writer_reset(writer); + free(writer); +} + +int sqfs_dir_writer_begin(sqfs_dir_writer_t *writer) +{ + uint32_t offset; + uint64_t block; + + writer_reset(writer); + + meta_writer_get_position(writer->dm, &block, &offset); + writer->dir_ref = (block << 16) | offset; + return 0; +} + +int sqfs_dir_writer_add_entry(sqfs_dir_writer_t *writer, const char *name, + uint32_t inode_num, uint64_t inode_ref, + mode_t mode) +{ + dir_entry_t *ent = alloc_flex(sizeof(*ent), 1, strlen(name)); + + if (ent == NULL) { + perror("creating directory entry"); + return -1; + } + + ent->inode_ref = inode_ref; + ent->inode_num = inode_num; + ent->type = get_type(mode); + ent->name_len = strlen(name); + memcpy(ent->name, name, ent->name_len); + + if (writer->list_end == NULL) { + writer->list = writer->list_end = ent; + } else { + writer->list_end->next = ent; + writer->list_end = ent; + } + + writer->dir_size += sizeof(ent) + ent->name_len; + return 0; +} + +static size_t get_conseq_entry_count(uint32_t offset, dir_entry_t *head) +{ + size_t size, count = 0; + dir_entry_t *it; + int32_t diff; + + size = (offset + sizeof(sqfs_dir_header_t)) % SQFS_META_BLOCK_SIZE; + + for (it = head; it != NULL; it = it->next) { + if ((it->inode_ref >> 16) != (head->inode_ref >> 16)) + break; + + diff = it->inode_num - head->inode_num; + + if (diff > 32767 || diff < -32767) + break; + + size += sizeof(sqfs_dir_entry_t) + it->name_len; + + if (count > 0 && size > SQFS_META_BLOCK_SIZE) + break; + + count += 1; + + if (count == SQFS_MAX_DIR_ENT) + break; + } + + return count; +} + +static int add_header(sqfs_dir_writer_t *writer, size_t count, + dir_entry_t *ref, uint64_t block) +{ + sqfs_dir_header_t hdr; + index_ent_t *idx; + + hdr.count = htole32(count - 1); + hdr.start_block = htole32(ref->inode_ref >> 16); + hdr.inode_number = htole32(ref->inode_num); + + if (meta_writer_append(writer->dm, &hdr, sizeof(hdr))) + return -1; + + idx = calloc(1, sizeof(*idx)); + if (idx == NULL) { + perror("creating directory index entry"); + return -1; + } + + idx->ent = ref; + idx->block = block; + idx->index = writer->dir_size; + + if (writer->idx_end == NULL) { + writer->idx = writer->idx_end = idx; + } else { + writer->idx_end->next = idx; + writer->idx_end = idx; + } + + writer->dir_size += sizeof(hdr); + writer->idx_size += 1; + return 0; +} + +int sqfs_dir_writer_end(sqfs_dir_writer_t *writer) +{ + dir_entry_t *it, *first; + sqfs_dir_entry_t ent; + uint16_t *diff_u16; + size_t i, count; + uint32_t offset; + uint64_t block; + + for (it = writer->list; it != NULL; ) { + meta_writer_get_position(writer->dm, &block, &offset); + count = get_conseq_entry_count(offset, it); + + if (add_header(writer, count, it, block)) + return -1; + + first = it; + + for (i = 0; i < count; ++i) { + ent.offset = htole16(it->inode_ref & 0x0000FFFF); + ent.inode_diff = it->inode_num - first->inode_num; + ent.type = htole16(it->type); + ent.size = htole16(it->name_len - 1); + + diff_u16 = (uint16_t *)&ent.inode_diff; + *diff_u16 = htole16(*diff_u16); + + if (meta_writer_append(writer->dm, &ent, sizeof(ent))) + return -1; + + if (meta_writer_append(writer->dm, it->name, it->name_len)) + return -1; + + it = it->next; + } + } + + return 0; +} + +size_t sqfs_dir_writer_get_size(sqfs_dir_writer_t *writer) +{ + return writer->dir_size; +} + +uint64_t sqfs_dir_writer_get_dir_reference(sqfs_dir_writer_t *writer) +{ + return writer->dir_ref; +} + +size_t sqfs_dir_writer_get_index_size(sqfs_dir_writer_t *writer) +{ + return writer->idx_size; +} + +int sqfs_dir_writer_write_index(sqfs_dir_writer_t *writer, + meta_writer_t *im) +{ + sqfs_dir_index_t ent; + index_ent_t *idx; + + for (idx = writer->idx; idx != NULL; idx = idx->next) { + ent.start_block = htole32(idx->block); + ent.index = htole32(idx->index); + ent.size = htole32(idx->ent->name_len - 1); + + if (meta_writer_append(im, &ent, sizeof(ent))) + return -1; + + if (meta_writer_append(im, idx->ent->name, idx->ent->name_len)) + return -1; + } + + return 0; +} diff --git a/lib/sqfshelper/serialize_fstree.c b/lib/sqfshelper/serialize_fstree.c index e6eccea..53e2236 100644 --- a/lib/sqfshelper/serialize_fstree.c +++ b/lib/sqfshelper/serialize_fstree.c @@ -16,6 +16,7 @@ int sqfs_serialize_fstree(int outfd, sqfs_super_t *super, fstree_t *fs, compressor_t *cmp, id_table_t *idtbl) { + sqfs_dir_writer_t *dirwr; meta_writer_t *im, *dm; uint32_t offset; uint64_t block; @@ -30,8 +31,12 @@ int sqfs_serialize_fstree(int outfd, sqfs_super_t *super, fstree_t *fs, if (dm == NULL) goto out_im; + dirwr = sqfs_dir_writer_create(dm); + if (dirwr == NULL) + goto out_dm; + for (i = 2; i < fs->inode_tbl_size; ++i) { - if (meta_writer_write_inode(fs, idtbl, im, dm, + if (meta_writer_write_inode(fs, idtbl, im, dirwr, fs->inode_table[i])) { goto out; } @@ -58,6 +63,8 @@ int sqfs_serialize_fstree(int outfd, sqfs_super_t *super, fstree_t *fs, ret = 0; out: + sqfs_dir_writer_destroy(dirwr); +out_dm: meta_writer_destroy(dm); out_im: meta_writer_destroy(im); diff --git a/lib/sqfshelper/write_dir.c b/lib/sqfshelper/write_dir.c deleted file mode 100644 index b977bc4..0000000 --- a/lib/sqfshelper/write_dir.c +++ /dev/null @@ -1,144 +0,0 @@ -/* SPDX-License-Identifier: GPL-3.0-or-later */ -/* - * write_dir.c - * - * Copyright (C) 2019 David Oberhollenzer - */ -#include "config.h" - -#include "sqfs/inode.h" -#include "sqfs/dir.h" -#include "highlevel.h" -#include "util.h" - -#include -#include -#include -#include -#include -#include - -static int get_type(mode_t mode) -{ - switch (mode & S_IFMT) { - case S_IFSOCK: return SQFS_INODE_SOCKET; - case S_IFIFO: return SQFS_INODE_FIFO; - case S_IFLNK: return SQFS_INODE_SLINK; - case S_IFBLK: return SQFS_INODE_BDEV; - case S_IFCHR: return SQFS_INODE_CDEV; - case S_IFDIR: return SQFS_INODE_DIR; - case S_IFREG: return SQFS_INODE_FILE; - default: - assert(0); - } -} - -static int dir_index_grow(dir_index_t **index) -{ - size_t size = sizeof(dir_index_t) + sizeof(idx_ref_t) * 10; - void *new; - - if (*index == NULL) { - new = calloc(1, size); - } else { - if ((*index)->num_nodes < (*index)->max_nodes) - return 0; - - size += sizeof(idx_ref_t) * (*index)->num_nodes; - new = realloc(*index, size); - } - - if (new == NULL) { - perror("creating directory index"); - return -1; - } - - *index = new; - (*index)->max_nodes += 10; - return 0; -} - -int meta_writer_write_dir(meta_writer_t *dm, dir_info_t *dir, - dir_index_t **index) -{ - size_t i, size, count; - sqfs_dir_header_t hdr; - sqfs_dir_entry_t ent; - tree_node_t *c, *d; - uint16_t *diff_u16; - uint32_t offset; - uint64_t block; - int32_t diff; - - c = dir->children; - dir->size = 0; - - meta_writer_get_position(dm, &dir->start_block, &dir->block_offset); - - while (c != NULL) { - meta_writer_get_position(dm, &block, &offset); - - count = 0; - size = (offset + sizeof(hdr)) % SQFS_META_BLOCK_SIZE; - - for (d = c; d != NULL; d = d->next) { - if ((d->inode_ref >> 16) != (c->inode_ref >> 16)) - break; - - diff = d->inode_num - c->inode_num; - - if (diff > 32767 || diff < -32767) - break; - - size += sizeof(ent) + strlen(c->name); - - if (count > 0 && size > SQFS_META_BLOCK_SIZE) - break; - - count += 1; - } - - if (count > SQFS_MAX_DIR_ENT) - count = SQFS_MAX_DIR_ENT; - - if (dir_index_grow(index)) - return -1; - - meta_writer_get_position(dm, &block, &offset); - - i = (*index)->num_nodes++; - (*index)->idx_nodes[i].node = c; - (*index)->idx_nodes[i].block = block; - (*index)->idx_nodes[i].index = dir->size; - - hdr.count = htole32(count - 1); - hdr.start_block = htole32(c->inode_ref >> 16); - hdr.inode_number = htole32(c->inode_num); - dir->size += sizeof(hdr); - - if (meta_writer_append(dm, &hdr, sizeof(hdr))) - return -1; - - d = c; - - for (i = 0; i < count; ++i) { - ent.inode_diff = c->inode_num - d->inode_num; - - diff_u16 = (uint16_t *)&ent.inode_diff; - *diff_u16 = htole16(*diff_u16); - - ent.offset = htole16(c->inode_ref & 0x0000FFFF); - ent.type = htole16(get_type(c->mode)); - ent.size = htole16(strlen(c->name) - 1); - dir->size += sizeof(ent) + strlen(c->name); - - if (meta_writer_append(dm, &ent, sizeof(ent))) - return -1; - if (meta_writer_append(dm, c->name, strlen(c->name))) - return -1; - - c = c->next; - } - } - return 0; -} diff --git a/lib/sqfshelper/write_inode.c b/lib/sqfshelper/write_inode.c index 1cd8e72..d9dfe53 100644 --- a/lib/sqfshelper/write_inode.c +++ b/lib/sqfshelper/write_inode.c @@ -103,32 +103,36 @@ static int write_file_blocks(fstree_t *fs, file_info_t *fi, meta_writer_t *im) return 0; } -static int write_dir_index(dir_index_t *diridx, meta_writer_t *im) +static int write_dir_entries(sqfs_dir_writer_t *dirw, tree_node_t *node) { - sqfs_dir_index_t idx; - size_t i; + tree_node_t *it; + uint64_t ref; + int ret; - for (i = 0; i < diridx->num_nodes; ++i) { - idx.start_block = htole32(diridx->idx_nodes[i].block); - idx.index = htole32(diridx->idx_nodes[i].index); - idx.size = strlen(diridx->idx_nodes[i].node->name) - 1; - idx.size = htole32(idx.size); - - if (meta_writer_append(im, &idx, sizeof(idx))) - return -1; + if (sqfs_dir_writer_begin(dirw)) + return -1; - if (meta_writer_append(im, diridx->idx_nodes[i].node->name, - le32toh(idx.size) + 1)) { + for (it = node->data.dir->children; it != NULL; it = it->next) { + ret = sqfs_dir_writer_add_entry(dirw, it->name, it->inode_num, + it->inode_ref, it->mode); + if (ret) return -1; - } } + + if (sqfs_dir_writer_end(dirw)) + return -1; + + ref = sqfs_dir_writer_get_dir_reference(dirw); + + node->data.dir->size = sqfs_dir_writer_get_size(dirw); + node->data.dir->start_block = ref >> 16; + node->data.dir->block_offset = ref & 0xFFFF; return 0; } int meta_writer_write_inode(fstree_t *fs, id_table_t *idtbl, meta_writer_t *im, - meta_writer_t *dm, tree_node_t *node) + sqfs_dir_writer_t *dirw, tree_node_t *node) { - dir_index_t *diridx = NULL; uint16_t uid_idx, gid_idx; sqfs_inode_t base; uint32_t offset; @@ -144,7 +148,7 @@ int meta_writer_write_inode(fstree_t *fs, id_table_t *idtbl, meta_writer_t *im, node->inode_ref = (block << 16) | offset; if (S_ISDIR(node->mode)) { - if (meta_writer_write_dir(dm, node->data.dir, &diridx)) + if (write_dir_entries(dirw, node)) return -1; } @@ -155,10 +159,8 @@ int meta_writer_write_inode(fstree_t *fs, id_table_t *idtbl, meta_writer_t *im, base.mod_time = htole32(node->mod_time); base.inode_number = htole32(node->inode_num); - if (meta_writer_append(im, &base, sizeof(base))) { - free(diridx); + if (meta_writer_append(im, &base, sizeof(base))) return -1; - } switch (le16toh(base.type)) { case SQFS_INODE_FIFO: @@ -292,6 +294,7 @@ int meta_writer_write_inode(fstree_t *fs, id_table_t *idtbl, meta_writer_t *im, return meta_writer_append(im, &dir, sizeof(dir)); } case SQFS_INODE_EXT_DIR: { + size_t idx_size; sqfs_inode_dir_ext_t ext = { .nlink = htole32(hard_link_count(node)), .size = htole32(node->data.dir->size), @@ -306,20 +309,16 @@ int meta_writer_write_inode(fstree_t *fs, id_table_t *idtbl, meta_writer_t *im, if (node->xattr != NULL) ext.xattr_idx = htole32(node->xattr->index); - if (diridx != NULL) - ext.inodex_count = htole32(diridx->num_nodes - 1); + idx_size = sqfs_dir_writer_get_index_size(dirw); - if (meta_writer_append(im, &ext, sizeof(ext))) { - free(diridx); - return -1; - } + if (idx_size > 0) + ext.inodex_count = htole32(idx_size - 1); - if (diridx != NULL && write_dir_index(diridx, im) != 0) { - free(diridx); + if (meta_writer_append(im, &ext, sizeof(ext))) return -1; - } - free(diridx); + if (sqfs_dir_writer_write_index(dirw, im)) + return -1; break; } default: -- cgit v1.2.3