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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-09-03 12:54:15 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-09-04 15:10:43 +0200
commitf780c9542d2c96cb0ae00a8de8d67b9a8fd278cd (patch)
tree8bde83d298124bd9ec8bb678e76a578ec62b10a7 /lib
parent949edd852d959c6350c4544632740e700c734b4f (diff)
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 <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib')
-rw-r--r--lib/Makemodule.am3
-rw-r--r--lib/sqfs/dir_writer.c287
-rw-r--r--lib/sqfshelper/serialize_fstree.c9
-rw-r--r--lib/sqfshelper/write_dir.c144
-rw-r--r--lib/sqfshelper/write_inode.c59
5 files changed, 325 insertions, 177 deletions
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 <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "sqfs/inode.h"
+#include "sqfs/dir.h"
+#include "util.h"
+
+#include <sys/stat.h>
+#include <endian.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+
+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 <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "sqfs/inode.h"
-#include "sqfs/dir.h"
-#include "highlevel.h"
-#include "util.h"
-
-#include <sys/stat.h>
-#include <assert.h>
-#include <endian.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-
-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: