Cleanup: try to split sqfs2tar.c in a reasonable way

This comit breaks sqfs2tar into multiple files:
 - options.c contains the command line argument processing
 - write_tree.c contains the code for generating the actual tar archive
 - sqfs2tar.c contains what is left
 - A header is added for glueing it all together.

No actual code is changed.

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

1 files changed, 211 insertions, 0 deletions

diff --git a/bin/sqfs2tar/write_tree.c b/bin/sqfs2tar/write_tree.c
new file mode 100644
index 0000000..545adc1
--- /dev/null
+++ b/bin/sqfs2tar/write_tree.c
@@ -0,0 +1,211 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * write_tree.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "sqfs2tar.h"
+
+static unsigned int record_counter;
+
+static int get_xattrs(const char *name, const sqfs_inode_generic_t *inode,
+		      tar_xattr_t **out)
+{
+	tar_xattr_t *list = NULL, *ent;
+	sqfs_xattr_value_t *value;
+	sqfs_xattr_entry_t *key;
+	sqfs_xattr_id_t desc;
+	sqfs_u32 index;
+	size_t i;
+	int ret;
+
+	if (xr == NULL)
+		return 0;
+
+	sqfs_inode_get_xattr_index(inode, &index);
+
+	if (index == 0xFFFFFFFF)
+		return 0;
+
+	ret = sqfs_xattr_reader_get_desc(xr, index, &desc);
+	if (ret) {
+		sqfs_perror(name, "resolving xattr index", ret);
+		return -1;
+	}
+
+	ret = sqfs_xattr_reader_seek_kv(xr, &desc);
+	if (ret) {
+		sqfs_perror(name, "locating xattr key-value pairs", ret);
+		return -1;
+	}
+
+	for (i = 0; i < desc.count; ++i) {
+		ret = sqfs_xattr_reader_read_key(xr, &key);
+		if (ret) {
+			sqfs_perror(name, "reading xattr key", ret);
+			goto fail;
+		}
+
+		ret = sqfs_xattr_reader_read_value(xr, key, &value);
+		if (ret) {
+			sqfs_perror(name, "reading xattr value", ret);
+			free(key);
+			goto fail;
+		}
+
+		ent = calloc(1, sizeof(*ent) + strlen((const char *)key->key) +
+			     value->size + 2);
+		if (ent == NULL) {
+			perror("creating xattr entry");
+			free(key);
+			free(value);
+			goto fail;
+		}
+
+		ent->key = ent->data;
+		strcpy(ent->key, (const char *)key->key);
+
+		ent->value = (sqfs_u8 *)ent->key + strlen(ent->key) + 1;
+		memcpy(ent->value, value->value, value->size + 1);
+
+		ent->value_len = value->size;
+		ent->next = list;
+		list = ent;
+
+		free(key);
+		free(value);
+	}
+
+	*out = list;
+	return 0;
+fail:
+	while (list != NULL) {
+		ent = list;
+		list = list->next;
+		free(ent);
+	}
+	return -1;
+}
+
+int write_tree_dfs(const sqfs_tree_node_t *n)
+{
+	tar_xattr_t *xattr = NULL, *xit;
+	sqfs_hard_link_t *lnk = NULL;
+	char *name, *target;
+	struct stat sb;
+	size_t len;
+	int ret;
+
+	inode_stat(n, &sb);
+
+	if (n->parent == NULL) {
+		if (root_becomes == NULL)
+			goto skip_hdr;
+
+		len = strlen(root_becomes);
+		name = malloc(len + 2);
+		if (name == NULL) {
+			perror("creating root directory");
+			return -1;
+		}
+
+		memcpy(name, root_becomes, len);
+		name[len] = '/';
+		name[len + 1] = '\0';
+	} else {
+		if (!is_filename_sane((const char *)n->name, false)) {
+			fprintf(stderr, "Found a file named '%s', skipping.\n",
+				n->name);
+			if (dont_skip) {
+				fputs("Not allowed to skip files, aborting!\n",
+				      stderr);
+				return -1;
+			}
+			return 0;
+		}
+
+		name = sqfs_tree_node_get_path(n);
+		if (name == NULL) {
+			perror("resolving tree node path");
+			return -1;
+		}
+
+		if (canonicalize_name(name))
+			goto out_skip;
+
+		for (lnk = links; lnk != NULL; lnk = lnk->next) {
+			if (lnk->inode_number == n->inode->base.inode_number) {
+				if (strcmp(name, lnk->target) == 0)
+					lnk = NULL;
+				break;
+			}
+		}
+
+		name = assemble_tar_path(name, S_ISDIR(sb.st_mode));
+		if (name == NULL)
+			return -1;
+	}
+
+	if (lnk != NULL) {
+		ret = write_hard_link(out_file, &sb, name, lnk->target,
+				      record_counter++);
+		free(name);
+		return ret;
+	}
+
+	if (!no_xattr) {
+		if (get_xattrs(name, n->inode, &xattr)) {
+			free(name);
+			return -1;
+		}
+	}
+
+	target = S_ISLNK(sb.st_mode) ? (char *)n->inode->extra : NULL;
+	ret = write_tar_header(out_file, &sb, name, target, xattr,
+			       record_counter++);
+
+	while (xattr != NULL) {
+		xit = xattr;
+		xattr = xattr->next;
+		free(xit);
+	}
+
+	if (ret > 0)
+		goto out_skip;
+
+	if (ret < 0) {
+		free(name);
+		return -1;
+	}
+
+	if (S_ISREG(sb.st_mode)) {
+		if (sqfs_data_reader_dump(name, data, n->inode, out_file,
+					  super.block_size, false)) {
+			free(name);
+			return -1;
+		}
+
+		if (padd_file(out_file, sb.st_size)) {
+			free(name);
+			return -1;
+		}
+	}
+
+	free(name);
+skip_hdr:
+	for (n = n->children; n != NULL; n = n->next) {
+		if (write_tree_dfs(n))
+			return -1;
+	}
+	return 0;
+out_skip:
+	if (dont_skip) {
+		fputs("Not allowed to skip files, aborting!\n", stderr);
+		ret = -1;
+	} else {
+		fprintf(stderr, "Skipping %s\n", name);
+		ret = 0;
+	}
+	free(name);
+	return ret;
+}