Internalize the layout of the id_table_t structure

As an opaque struct it has a chance to change its layout in the future
without breaking ABI compatibiliy.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

6 files changed, 110 insertions, 113 deletions

diff --git a/lib/Makemodule.am b/lib/Makemodule.am
index 3681344..180833e 100644
--- a/lib/Makemodule.am
+++ b/lib/Makemodule.am
@@ -53,8 +53,7 @@ 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/write_table.c include/highlevel.h
 libsquashfs_la_SOURCES += lib/sqfs/read_super.c lib/sqfs/meta_reader.c
-libsquashfs_la_SOURCES += lib/sqfs/id_table_write.c
-libsquashfs_la_SOURCES += lib/sqfs/id_table_read.c lib/sqfs/read_inode.c
+libsquashfs_la_SOURCES += lib/sqfs/read_inode.c
 libsquashfs_la_SOURCES += lib/sqfs/readdir.c
 libsquashfs_la_SOURCES += lib/sqfs/xattr.c
 libsquashfs_la_SOURCES += lib/sqfs/read_table.c
diff --git a/lib/sqfs/id_table.c b/lib/sqfs/id_table.c
index 192cdbb..75d5db4 100644
--- a/lib/sqfs/id_table.c
+++ b/lib/sqfs/id_table.c
@@ -7,20 +7,32 @@
 #include "config.h"
 
 #include "sqfs/id_table.h"
+#include "sqfs/table.h"
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
-int id_table_init(id_table_t *tbl)
+struct id_table_t {
+	uint32_t *ids;
+	size_t num_ids;
+	size_t max_ids;
+};
+
+id_table_t *id_table_create(void)
 {
-	memset(tbl, 0, sizeof(*tbl));
-	return 0;
+	id_table_t *tbl = calloc(1, sizeof(*tbl));
+
+	if (tbl == NULL)
+		perror("Creating ID table");
+
+	return tbl;
 }
 
-void id_table_cleanup(id_table_t *tbl)
+void id_table_destroy(id_table_t *tbl)
 {
 	free(tbl->ids);
+	free(tbl);
 }
 
 int id_table_id_to_index(id_table_t *tbl, uint32_t id, uint16_t *out)
@@ -57,3 +69,82 @@ 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_index_to_id(const id_table_t *tbl, uint16_t index, uint32_t *out)
+{
+	if (index >= tbl->num_ids) {
+		fputs("attempted out of bounds ID table access\n", stderr);
+		return -1;
+	}
+
+	*out = tbl->ids[index];
+	return 0;
+}
+
+int id_table_read(id_table_t *tbl, int fd, sqfs_super_t *super,
+		  compressor_t *cmp)
+{
+	uint64_t upper_limit, lower_limit;
+	size_t i;
+
+	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;
+	}
+
+	upper_limit = super->id_table_start;
+	lower_limit = super->directory_table_start;
+
+	if (super->fragment_table_start > lower_limit &&
+	    super->fragment_table_start < upper_limit) {
+		lower_limit = super->fragment_table_start;
+	}
+
+	if (super->export_table_start > lower_limit &&
+	    super->export_table_start < upper_limit) {
+		lower_limit = super->export_table_start;
+	}
+
+	tbl->num_ids = super->id_count;
+	tbl->max_ids = super->id_count;
+	tbl->ids = sqfs_read_table(fd, cmp, tbl->num_ids * sizeof(uint32_t),
+				   super->id_table_start, lower_limit,
+				   upper_limit);
+	if (tbl->ids == NULL)
+		return -1;
+
+	for (i = 0; i < tbl->num_ids; ++i)
+		tbl->ids[i] = le32toh(tbl->ids[i]);
+
+	return 0;
+}
+
+int id_table_write(id_table_t *tbl, int outfd, sqfs_super_t *super,
+		   compressor_t *cmp)
+{
+	uint64_t start;
+	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, cmp, tbl->ids,
+			       sizeof(tbl->ids[0]) * tbl->num_ids, &start);
+
+	super->id_table_start = start;
+
+	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
deleted file mode 100644
index ccb0fc8..0000000
--- a/lib/sqfs/id_table_read.c
+++ /dev/null
@@ -1,58 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * id_table_read.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "highlevel.h"
-#include "util.h"
-
-#include <stdlib.h>
-#include <stdio.h>
-
-int id_table_read(id_table_t *tbl, int fd, sqfs_super_t *super,
-		  compressor_t *cmp)
-{
-	uint64_t upper_limit, lower_limit;
-	size_t i;
-
-	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;
-	}
-
-	upper_limit = super->id_table_start;
-	lower_limit = super->directory_table_start;
-
-	if (super->fragment_table_start > lower_limit &&
-	    super->fragment_table_start < upper_limit) {
-		lower_limit = super->fragment_table_start;
-	}
-
-	if (super->export_table_start > lower_limit &&
-	    super->export_table_start < upper_limit) {
-		lower_limit = super->export_table_start;
-	}
-
-	tbl->num_ids = super->id_count;
-	tbl->max_ids = super->id_count;
-	tbl->ids = sqfs_read_table(fd, cmp, tbl->num_ids * sizeof(uint32_t),
-				   super->id_table_start, lower_limit,
-				   upper_limit);
-	if (tbl->ids == NULL)
-		return -1;
-
-	for (i = 0; i < tbl->num_ids; ++i)
-		tbl->ids[i] = le32toh(tbl->ids[i]);
-
-	return 0;
-}
diff --git a/lib/sqfs/id_table_write.c b/lib/sqfs/id_table_write.c
deleted file mode 100644
index 0f0e475..0000000
--- a/lib/sqfs/id_table_write.c
+++ /dev/null
@@ -1,32 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * id_table_write.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "highlevel.h"
-
-int id_table_write(id_table_t *tbl, int outfd, sqfs_super_t *super,
-		   compressor_t *cmp)
-{
-	uint64_t start;
-	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, cmp, tbl->ids,
-			       sizeof(tbl->ids[0]) * tbl->num_ids, &start);
-
-	super->id_table_start = start;
-
-	for (i = 0; i < tbl->num_ids; ++i)
-		tbl->ids[i] = le32toh(tbl->ids[i]);
-
-	return ret;
-}
diff --git a/lib/sqfshelper/deserialize_fstree.c b/lib/sqfshelper/deserialize_fstree.c
index 232c382..c418b16 100644
--- a/lib/sqfshelper/deserialize_fstree.c
+++ b/lib/sqfshelper/deserialize_fstree.c
@@ -207,7 +207,7 @@ int deserialize_fstree(fstree_t *out, sqfs_super_t *super, compressor_t *cmp,
 	sqfs_inode_generic_t *root;
 	meta_reader_t *ir, *dr;
 	xattr_reader_t *xr;
-	id_table_t idtbl;
+	id_table_t *idtbl;
 	int status = -1;
 	size_t offset;
 
@@ -226,10 +226,11 @@ int deserialize_fstree(fstree_t *out, sqfs_super_t *super, compressor_t *cmp,
 	if (dr == NULL)
 		goto out_ir;
 
-	if (id_table_init(&idtbl))
+	idtbl = id_table_create();
+	if (idtbl == NULL)
 		goto out_dr;
 
-	if (id_table_read(&idtbl, fd, super, cmp))
+	if (id_table_read(idtbl, fd, super, cmp))
 		goto out_id;
 
 	xr = xattr_reader_create(fd, super, cmp);
@@ -257,7 +258,7 @@ int deserialize_fstree(fstree_t *out, sqfs_super_t *super, compressor_t *cmp,
 	out->defaults.st_mode = 0755;
 	out->defaults.st_mtime = super->modification_time;
 
-	out->root = tree_node_from_inode(root, &idtbl, "", super->block_size);
+	out->root = tree_node_from_inode(root, idtbl, "", super->block_size);
 
 	if (out->root == NULL) {
 		free(root);
@@ -285,7 +286,7 @@ int deserialize_fstree(fstree_t *out, sqfs_super_t *super, compressor_t *cmp,
 
 	free(root);
 
-	if (fill_dir(ir, dr, out->root, super, &idtbl, out, xr, flags))
+	if (fill_dir(ir, dr, out->root, super, idtbl, out, xr, flags))
 		goto fail_fs;
 
 	tree_node_sort_recursive(out->root);
@@ -294,7 +295,7 @@ int deserialize_fstree(fstree_t *out, sqfs_super_t *super, compressor_t *cmp,
 out_xr:
 	xattr_reader_destroy(xr);
 out_id:
-	id_table_cleanup(&idtbl);
+	id_table_destroy(idtbl);
 out_dr:
 	meta_reader_destroy(dr);
 out_ir:
diff --git a/lib/sqfshelper/tree_node_from_inode.c b/lib/sqfshelper/tree_node_from_inode.c
index 582399c..e77266a 100644
--- a/lib/sqfshelper/tree_node_from_inode.c
+++ b/lib/sqfshelper/tree_node_from_inode.c
@@ -73,26 +73,22 @@ tree_node_t *tree_node_from_inode(sqfs_inode_generic_t *inode,
 {
 	tree_node_t *out;
 
-	if (inode->base.uid_idx >= idtbl->num_ids) {
-		fputs("converting inode to fs tree node: UID out of range\n",
-		      stderr);
+	out = calloc(1, compute_size(inode, name, block_size));
+	if (out == NULL) {
+		perror("converting inode to fs tree node");
 		return NULL;
 	}
 
-	if (inode->base.gid_idx >= idtbl->num_ids) {
-		fputs("converting inode to fs tree node: GID out of range\n",
-		      stderr);
+	if (id_table_index_to_id(idtbl, inode->base.uid_idx, &out->uid)) {
+		free(out);
 		return NULL;
 	}
 
-	out = calloc(1, compute_size(inode, name, block_size));
-	if (out == NULL) {
-		perror("converting inode to fs tree node");
+	if (id_table_index_to_id(idtbl, inode->base.gid_idx, &out->gid)) {
+		free(out);
 		return NULL;
 	}
 
-	out->uid = idtbl->ids[inode->base.uid_idx];
-	out->gid = idtbl->ids[inode->base.gid_idx];
 	out->mode = inode->base.mode;
 	out->inode_num = inode->base.inode_number;
 	out->mod_time = inode->base.mod_time;