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, 291 insertions, 0 deletions

diff --git a/bin/sqfs2tar/sqfs2tar.c b/bin/sqfs2tar/sqfs2tar.c
new file mode 100644
index 0000000..305bd4b
--- /dev/null
+++ b/bin/sqfs2tar/sqfs2tar.c
@@ -0,0 +1,291 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * sqfs2tar.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "sqfs2tar.h"
+
+sqfs_xattr_reader_t *xr;
+sqfs_data_reader_t *data;
+sqfs_super_t super;
+sqfs_hard_link_t *links = NULL;
+FILE *out_file = NULL;
+
+static sqfs_file_t *file;
+
+char *assemble_tar_path(char *name, bool is_dir)
+{
+	size_t len, new_len;
+	char *temp;
+	(void)is_dir;
+
+	if (root_becomes == NULL && !is_dir)
+		return name;
+
+	new_len = strlen(name);
+	if (root_becomes != NULL)
+		new_len += strlen(root_becomes) + 1;
+	if (is_dir)
+		new_len += 1;
+
+	temp = realloc(name, new_len + 1);
+	if (temp == NULL) {
+		perror("assembling tar entry filename");
+		free(name);
+		return NULL;
+	}
+
+	name = temp;
+
+	if (root_becomes != NULL) {
+		len = strlen(root_becomes);
+
+		memmove(name + len + 1, name, strlen(name) + 1);
+		memcpy(name, root_becomes, len);
+		name[len] = '/';
+	}
+
+	if (is_dir) {
+		len = strlen(name);
+
+		if (len == 0 || name[len - 1] != '/') {
+			name[len++] = '/';
+			name[len] = '\0';
+		}
+	}
+
+	return name;
+}
+
+static int terminate_archive(void)
+{
+	char buffer[1024];
+
+	memset(buffer, '\0', sizeof(buffer));
+
+	return write_retry("adding archive terminator", out_file,
+			   buffer, sizeof(buffer));
+}
+
+static sqfs_tree_node_t *tree_merge(sqfs_tree_node_t *lhs,
+				    sqfs_tree_node_t *rhs)
+{
+	sqfs_tree_node_t *head = NULL, **next_ptr = &head;
+	sqfs_tree_node_t *it, *l, *r;
+	int diff;
+
+	while (lhs->children != NULL && rhs->children != NULL) {
+		diff = strcmp((const char *)lhs->children->name,
+			      (const char *)rhs->children->name);
+
+		if (diff < 0) {
+			it = lhs->children;
+			lhs->children = lhs->children->next;
+		} else if (diff > 0) {
+			it = rhs->children;
+			rhs->children = rhs->children->next;
+		} else {
+			l = lhs->children;
+			lhs->children = lhs->children->next;
+
+			r = rhs->children;
+			rhs->children = rhs->children->next;
+
+			it = tree_merge(l, r);
+		}
+
+		*next_ptr = it;
+		next_ptr = &it->next;
+	}
+
+	it = (lhs->children != NULL ? lhs->children : rhs->children);
+	*next_ptr = it;
+
+	sqfs_dir_tree_destroy(rhs);
+	lhs->children = head;
+	return lhs;
+}
+
+int main(int argc, char **argv)
+{
+	sqfs_tree_node_t *root = NULL, *subtree;
+	int flags, ret, status = EXIT_FAILURE;
+	sqfs_compressor_config_t cfg;
+	sqfs_compressor_t *cmp;
+	sqfs_id_table_t *idtbl;
+	sqfs_dir_reader_t *dr;
+	sqfs_hard_link_t *lnk;
+	size_t i;
+
+	process_args(argc, argv);
+
+#ifdef _WIN32
+	_setmode(_fileno(stdout), _O_BINARY);
+	out_file = stdout;
+#else
+	out_file = freopen(NULL, "wb", stdout);
+#endif
+
+	if (out_file == NULL) {
+		perror("changing stdout to binary mode");
+		goto out_dirs;
+	}
+
+	file = sqfs_open_file(filename, SQFS_FILE_OPEN_READ_ONLY);
+	if (file == NULL) {
+		perror(filename);
+		goto out_dirs;
+	}
+
+	ret = sqfs_super_read(&super, file);
+	if (ret) {
+		sqfs_perror(filename, "reading super block", ret);
+		goto out_fd;
+	}
+
+	sqfs_compressor_config_init(&cfg, super.compression_id,
+				    super.block_size,
+				    SQFS_COMP_FLAG_UNCOMPRESS);
+
+	ret = sqfs_compressor_create(&cfg, &cmp);
+
+#ifdef WITH_LZO
+	if (super.compression_id == SQFS_COMP_LZO && ret != 0)
+		ret = lzo_compressor_create(&cfg, &cmp);
+#endif
+
+	if (ret != 0) {
+		sqfs_perror(filename, "creating compressor", ret);
+		goto out_fd;
+	}
+
+	idtbl = sqfs_id_table_create(0);
+
+	if (idtbl == NULL) {
+		perror("creating ID table");
+		goto out_cmp;
+	}
+
+	ret = sqfs_id_table_read(idtbl, file, &super, cmp);
+	if (ret) {
+		sqfs_perror(filename, "loading ID table", ret);
+		goto out_id;
+	}
+
+	data = sqfs_data_reader_create(file, super.block_size, cmp);
+	if (data == NULL) {
+		sqfs_perror(filename, "creating data reader",
+			    SQFS_ERROR_ALLOC);
+		goto out_id;
+	}
+
+	ret = sqfs_data_reader_load_fragment_table(data, &super);
+	if (ret) {
+		sqfs_perror(filename, "loading fragment table", ret);
+		goto out_data;
+	}
+
+	dr = sqfs_dir_reader_create(&super, cmp, file);
+	if (dr == NULL) {
+		sqfs_perror(filename, "creating dir reader",
+			    SQFS_ERROR_ALLOC);
+		goto out_data;
+	}
+
+	if (!no_xattr && !(super.flags & SQFS_FLAG_NO_XATTRS)) {
+		xr = sqfs_xattr_reader_create(0);
+		if (xr == NULL) {
+			sqfs_perror(filename, "creating xattr reader",
+				    SQFS_ERROR_ALLOC);
+			goto out_dr;
+		}
+
+		ret = sqfs_xattr_reader_load(xr, &super, file, cmp);
+		if (ret) {
+			sqfs_perror(filename, "loading xattr table", ret);
+			goto out_xr;
+		}
+	}
+
+	if (num_subdirs == 0) {
+		ret = sqfs_dir_reader_get_full_hierarchy(dr, idtbl, NULL,
+							 0, &root);
+		if (ret) {
+			sqfs_perror(filename, "loading filesystem tree", ret);
+			goto out;
+		}
+	} else {
+		flags = 0;
+
+		if (keep_as_dir || num_subdirs > 1)
+			flags = SQFS_TREE_STORE_PARENTS;
+
+		for (i = 0; i < num_subdirs; ++i) {
+			ret = sqfs_dir_reader_get_full_hierarchy(dr, idtbl,
+								 subdirs[i],
+								 flags,
+								 &subtree);
+			if (ret) {
+				sqfs_perror(subdirs[i], "loading filesystem "
+					    "tree", ret);
+				goto out;
+			}
+
+			if (root == NULL) {
+				root = subtree;
+			} else {
+				root = tree_merge(root, subtree);
+			}
+		}
+	}
+
+	if (!no_links) {
+		if (sqfs_tree_find_hard_links(root, &links))
+			goto out_tree;
+
+		for (lnk = links; lnk != NULL; lnk = lnk->next) {
+			lnk->target = assemble_tar_path(lnk->target, false);
+			if (lnk->target == NULL)
+				goto out;
+		}
+	}
+
+	if (write_tree_dfs(root))
+		goto out;
+
+	if (terminate_archive())
+		goto out;
+
+	status = EXIT_SUCCESS;
+	fflush(out_file);
+out:
+	while (links != NULL) {
+		lnk = links;
+		links = links->next;
+		free(lnk->target);
+		free(lnk);
+	}
+out_tree:
+	if (root != NULL)
+		sqfs_dir_tree_destroy(root);
+out_xr:
+	if (xr != NULL)
+		sqfs_destroy(xr);
+out_dr:
+	sqfs_destroy(dr);
+out_data:
+	sqfs_destroy(data);
+out_id:
+	sqfs_destroy(idtbl);
+out_cmp:
+	sqfs_destroy(cmp);
+out_fd:
+	sqfs_destroy(file);
+out_dirs:
+	for (i = 0; i < num_subdirs; ++i)
+		free(subdirs[i]);
+	free(subdirs);
+	free(root_becomes);
+	return status;
+}