Cleanup: try to split tar2sqfs.c in a reasonable way

This commit breaks tar2sqfs.c into multiple files:
 - options.c contains the command line argument processing
 - process_tarball.c contains the main tar repacking code
 - tar2sqfs.c contains what is left (the main function)
 - A header is added for gluing it all together.

No actual code is changed. The tar repacking code is slightly modified
to pass the sqfs writer and input file pointer around as argument rather
than using a global variable.

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

1 files changed, 272 insertions, 0 deletions

diff --git a/bin/tar2sqfs/process_tarball.c b/bin/tar2sqfs/process_tarball.c
new file mode 100644
index 0000000..3863014
--- /dev/null
+++ b/bin/tar2sqfs/process_tarball.c
@@ -0,0 +1,272 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * process_tarball.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "tar2sqfs.h"
+
+static int write_file(FILE *input_file, sqfs_writer_t *sqfs,
+		      const tar_header_decoded_t *hdr,
+		      file_info_t *fi, sqfs_u64 filesize)
+{
+	sqfs_file_t *file;
+	int flags;
+	int ret;
+
+	file = sqfs_get_stdin_file(input_file, hdr->sparse, filesize);
+	if (file == NULL) {
+		perror("packing files");
+		return -1;
+	}
+
+	flags = 0;
+	if (no_tail_pack && filesize > cfg.block_size)
+		flags |= SQFS_BLK_DONT_FRAGMENT;
+
+	ret = write_data_from_file(hdr->name, sqfs->data,
+				   (sqfs_inode_generic_t **)&fi->user_ptr,
+				   file, flags);
+	sqfs_destroy(file);
+
+	if (ret)
+		return -1;
+
+	return skip_padding(input_file, hdr->sparse == NULL ?
+			    filesize : hdr->record_size);
+}
+
+static int copy_xattr(sqfs_writer_t *sqfs, tree_node_t *node,
+		      const tar_header_decoded_t *hdr)
+{
+	tar_xattr_t *xattr;
+	int ret;
+
+	ret = sqfs_xattr_writer_begin(sqfs->xwr);
+	if (ret) {
+		sqfs_perror(hdr->name, "beginning xattr block", ret);
+		return -1;
+	}
+
+	for (xattr = hdr->xattr; xattr != NULL; xattr = xattr->next) {
+		if (sqfs_get_xattr_prefix_id(xattr->key) < 0) {
+			fprintf(stderr, "%s: squashfs does not "
+				"support xattr prefix of %s\n",
+				dont_skip ? "ERROR" : "WARNING",
+				xattr->key);
+
+			if (dont_skip)
+				return -1;
+			continue;
+		}
+
+		ret = sqfs_xattr_writer_add(sqfs->xwr, xattr->key, xattr->value,
+					    xattr->value_len);
+		if (ret) {
+			sqfs_perror(hdr->name, "storing xattr key-value pair",
+				    ret);
+			return -1;
+		}
+	}
+
+	ret = sqfs_xattr_writer_end(sqfs->xwr, &node->xattr_idx);
+	if (ret) {
+		sqfs_perror(hdr->name, "completing xattr block", ret);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int create_node_and_repack_data(FILE *input_file, sqfs_writer_t *sqfs,
+				       tar_header_decoded_t *hdr)
+{
+	tree_node_t *node;
+
+	if (hdr->is_hard_link) {
+		node = fstree_add_hard_link(&sqfs->fs, hdr->name,
+					    hdr->link_target);
+		if (node == NULL)
+			goto fail_errno;
+
+		if (!cfg.quiet) {
+			printf("Hard link %s -> %s\n", hdr->name,
+			       hdr->link_target);
+		}
+		return 0;
+	}
+
+	if (!keep_time) {
+		hdr->sb.st_mtime = sqfs->fs.defaults.st_mtime;
+	}
+
+	node = fstree_add_generic(&sqfs->fs, hdr->name,
+				  &hdr->sb, hdr->link_target);
+	if (node == NULL)
+		goto fail_errno;
+
+	if (!cfg.quiet)
+		printf("Packing %s\n", hdr->name);
+
+	if (!cfg.no_xattr) {
+		if (copy_xattr(sqfs, node, hdr))
+			return -1;
+	}
+
+	if (S_ISREG(hdr->sb.st_mode)) {
+		if (write_file(input_file, sqfs, hdr, &node->data.file,
+			       hdr->sb.st_size)) {
+			return -1;
+		}
+	}
+
+	return 0;
+fail_errno:
+	perror(hdr->name);
+	return -1;
+}
+
+static int set_root_attribs(sqfs_writer_t *sqfs,
+			    const tar_header_decoded_t *hdr)
+{
+	if (hdr->is_hard_link || !S_ISDIR(hdr->sb.st_mode)) {
+		fprintf(stderr, "'%s' is not a directory!\n", hdr->name);
+		return -1;
+	}
+
+	sqfs->fs.root->uid = hdr->sb.st_uid;
+	sqfs->fs.root->gid = hdr->sb.st_gid;
+	sqfs->fs.root->mode = hdr->sb.st_mode;
+
+	if (keep_time)
+		sqfs->fs.root->mod_time = hdr->sb.st_mtime;
+
+	if (!cfg.no_xattr) {
+		if (copy_xattr(sqfs, sqfs->fs.root, hdr))
+			return -1;
+	}
+
+	return 0;
+}
+
+int process_tarball(FILE *input_file, sqfs_writer_t *sqfs)
+{
+	bool skip, is_root, is_prefixed;
+	tar_header_decoded_t hdr;
+	sqfs_u64 offset, count;
+	sparse_map_t *m;
+	size_t rootlen;
+	int ret;
+
+	rootlen = root_becomes == NULL ? 0 : strlen(root_becomes);
+
+	for (;;) {
+		ret = read_header(input_file, &hdr);
+		if (ret > 0)
+			break;
+		if (ret < 0)
+			return -1;
+
+		if (hdr.mtime < 0)
+			hdr.mtime = 0;
+
+		if ((sqfs_u64)hdr.mtime > 0x0FFFFFFFFUL)
+			hdr.mtime = 0x0FFFFFFFFUL;
+
+		hdr.sb.st_mtime = hdr.mtime;
+
+		skip = false;
+		is_root = false;
+		is_prefixed = true;
+
+		if (hdr.name == NULL || canonicalize_name(hdr.name) != 0) {
+			fprintf(stderr, "skipping '%s' (invalid name)\n",
+				hdr.name);
+			skip = true;
+		}
+
+		if (root_becomes != NULL) {
+			if (strncmp(hdr.name, root_becomes, rootlen) == 0) {
+				if (hdr.name[rootlen] == '\0') {
+					is_root = true;
+				} else if (hdr.name[rootlen] != '/') {
+					is_prefixed = false;
+				}
+			} else {
+				is_prefixed = false;
+			}
+
+			if (is_prefixed && !is_root) {
+				memmove(hdr.name, hdr.name + rootlen + 1,
+					strlen(hdr.name + rootlen + 1) + 1);
+			}
+
+			if (is_prefixed && hdr.name[0] == '\0') {
+				fputs("skipping entry with empty name\n",
+				      stderr);
+				skip = true;
+			}
+		} else if (hdr.name[0] == '\0') {
+			is_root = true;
+		}
+
+		if (!is_prefixed) {
+			clear_header(&hdr);
+			continue;
+		}
+
+		if (is_root) {
+			if (set_root_attribs(sqfs, &hdr))
+				goto fail;
+			clear_header(&hdr);
+			continue;
+		}
+
+		if (!skip && hdr.unknown_record) {
+			fprintf(stderr, "%s: unknown entry type\n", hdr.name);
+			skip = true;
+		}
+
+		if (!skip && hdr.sparse != NULL) {
+			offset = hdr.sparse->offset;
+			count = 0;
+
+			for (m = hdr.sparse; m != NULL; m = m->next) {
+				if (m->offset < offset) {
+					skip = true;
+					break;
+				}
+				offset = m->offset + m->count;
+				count += m->count;
+			}
+
+			if (count != hdr.record_size)
+				skip = true;
+
+			if (skip) {
+				fprintf(stderr, "%s: broken sparse "
+					"file layout\n", hdr.name);
+			}
+		}
+
+		if (skip) {
+			if (dont_skip)
+				goto fail;
+			if (skip_entry(input_file, hdr.sb.st_size))
+				goto fail;
+
+			clear_header(&hdr);
+			continue;
+		}
+
+		if (create_node_and_repack_data(input_file, sqfs, &hdr))
+			goto fail;
+
+		clear_header(&hdr);
+	}
+
+	return 0;
+fail:
+	clear_header(&hdr);
+	return -1;
+}