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>

4 files changed, 583 insertions, 0 deletions

diff --git a/bin/tar2sqfs/options.c b/bin/tar2sqfs/options.c
new file mode 100644
index 0000000..b5aa3ba
--- /dev/null
+++ b/bin/tar2sqfs/options.c
@@ -0,0 +1,228 @@
+#include "tar2sqfs.h"
+
+static struct option long_opts[] = {
+	{ "root-becomes", required_argument, NULL, 'r' },
+	{ "compressor", required_argument, NULL, 'c' },
+	{ "block-size", required_argument, NULL, 'b' },
+	{ "dev-block-size", required_argument, NULL, 'B' },
+	{ "defaults", required_argument, NULL, 'd' },
+	{ "num-jobs", required_argument, NULL, 'j' },
+	{ "queue-backlog", required_argument, NULL, 'Q' },
+	{ "comp-extra", required_argument, NULL, 'X' },
+	{ "no-skip", no_argument, NULL, 's' },
+	{ "no-xattr", no_argument, NULL, 'x' },
+	{ "no-keep-time", no_argument, NULL, 'k' },
+	{ "exportable", no_argument, NULL, 'e' },
+	{ "no-tail-packing", no_argument, NULL, 'T' },
+	{ "force", no_argument, NULL, 'f' },
+	{ "quiet", no_argument, NULL, 'q' },
+	{ "help", no_argument, NULL, 'h' },
+	{ "version", no_argument, NULL, 'V' },
+	{ NULL, 0, NULL, 0 },
+};
+
+static const char *short_opts = "r:c:b:B:d:X:j:Q:sxekfqThV";
+
+static const char *usagestr =
+"Usage: tar2sqfs [OPTIONS...] <sqfsfile>\n"
+"\n"
+"Read an uncompressed tar archive from stdin and turn it into a squashfs\n"
+"filesystem image.\n"
+"\n"
+"Possible options:\n"
+"\n"
+"  --root-becomes, -r <dir>    The specified directory becomes the root.\n"
+"                              Only its children are packed into the image\n"
+"                              and its attributes (ownership, permissions,\n"
+"                              xattrs, ...) are stored in the root inode.\n"
+"                              If not set and a tarbal has an entry for './'\n"
+"                              or '/', it becomes the root instead.\n"
+"\n"
+"  --compressor, -c <name>     Select the compressor to use.\n"
+"                              A list of available compressors is below.\n"
+"  --comp-extra, -X <options>  A comma separated list of extra options for\n"
+"                              the selected compressor. Specify 'help' to\n"
+"                              get a list of available options.\n"
+"  --num-jobs, -j <count>      Number of compressor jobs to create.\n"
+"  --queue-backlog, -Q <count> Maximum number of data blocks in the thread\n"
+"                              worker queue before the packer starts waiting\n"
+"                              for the block processors to catch up.\n"
+"                              Defaults to 10 times the number of jobs.\n"
+"  --block-size, -b <size>     Block size to use for Squashfs image.\n"
+"                              Defaults to %u.\n"
+"  --dev-block-size, -B <size> Device block size to padd the image to.\n"
+"                              Defaults to %u.\n"
+"  --defaults, -d <options>    A comma separated list of default values for\n"
+"                              implicitly created directories.\n"
+"\n"
+"                              Possible options:\n"
+"                                 uid=<value>    0 if not set.\n"
+"                                 gid=<value>    0 if not set.\n"
+"                                 mode=<value>   0755 if not set.\n"
+"                                 mtime=<value>  0 if not set.\n"
+"\n"
+"  --no-skip, -s               Abort if a tar record cannot be read instead\n"
+"                              of skipping it.\n"
+"  --no-xattr, -x              Do not copy extended attributes from archive.\n"
+"  --no-keep-time, -k          Do not keep the time stamps stored in the\n"
+"                              archive. Instead, set defaults on all files.\n"
+"  --exportable, -e            Generate an export table for NFS support.\n"
+"  --no-tail-packing, -T       Do not perform tail end packing on files that\n"
+"                              are larger than block size.\n"
+"  --force, -f                 Overwrite the output file if it exists.\n"
+"  --quiet, -q                 Do not print out progress reports.\n"
+"  --help, -h                  Print help text and exit.\n"
+"  --version, -V               Print version information and exit.\n"
+"\n"
+"Examples:\n"
+"\n"
+"\ttar2sqfs rootfs.sqfs < rootfs.tar\n"
+"\tzcat rootfs.tar.gz | tar2sqfs rootfs.sqfs\n"
+"\txzcat rootfs.tar.xz | tar2sqfs rootfs.sqfs\n"
+"\n";
+
+bool dont_skip = false;
+bool keep_time = true;
+bool no_tail_pack = false;
+sqfs_writer_cfg_t cfg;
+char *root_becomes = NULL;
+
+void process_args(int argc, char **argv)
+{
+	bool have_compressor;
+	int i, ret;
+
+	sqfs_writer_cfg_init(&cfg);
+
+	for (;;) {
+		i = getopt_long(argc, argv, short_opts, long_opts, NULL);
+		if (i == -1)
+			break;
+
+		switch (i) {
+		case 'T':
+			no_tail_pack = true;
+			break;
+		case 'b':
+			if (parse_size("Block size", &cfg.block_size,
+				       optarg, 0)) {
+				exit(EXIT_FAILURE);
+			}
+			break;
+		case 'B':
+			if (parse_size("Device block size", &cfg.devblksize,
+				       optarg, 0)) {
+				exit(EXIT_FAILURE);
+			}
+			if (cfg.devblksize < 1024) {
+				fputs("Device block size must be at "
+				      "least 1024\n", stderr);
+				exit(EXIT_FAILURE);
+			}
+			break;
+		case 'c':
+			have_compressor = true;
+			ret = sqfs_compressor_id_from_name(optarg);
+
+			if (ret < 0) {
+				have_compressor = false;
+#ifdef WITH_LZO
+				if (cfg.comp_id == SQFS_COMP_LZO)
+					have_compressor = true;
+#endif
+			}
+
+			if (!have_compressor) {
+				fprintf(stderr, "Unsupported compressor '%s'\n",
+					optarg);
+				exit(EXIT_FAILURE);
+			}
+
+			cfg.comp_id = ret;
+			break;
+		case 'j':
+			cfg.num_jobs = strtol(optarg, NULL, 0);
+			break;
+		case 'Q':
+			cfg.max_backlog = strtol(optarg, NULL, 0);
+			break;
+		case 'X':
+			cfg.comp_extra = optarg;
+			break;
+		case 'd':
+			cfg.fs_defaults = optarg;
+			break;
+		case 'x':
+			cfg.no_xattr = true;
+			break;
+		case 'k':
+			keep_time = false;
+			break;
+		case 'r':
+			free(root_becomes);
+			root_becomes = strdup(optarg);
+			if (root_becomes == NULL) {
+				perror("copying root directory name");
+				exit(EXIT_FAILURE);
+			}
+
+			if (canonicalize_name(root_becomes) != 0 ||
+			    strlen(root_becomes) == 0) {
+				fprintf(stderr,
+					"Invalid root directory '%s'.\n",
+					optarg);
+				goto fail_arg;
+			}
+			break;
+		case 's':
+			dont_skip = true;
+			break;
+		case 'e':
+			cfg.exportable = true;
+			break;
+		case 'f':
+			cfg.outmode |= SQFS_FILE_OPEN_OVERWRITE;
+			break;
+		case 'q':
+			cfg.quiet = true;
+			break;
+		case 'h':
+			printf(usagestr, SQFS_DEFAULT_BLOCK_SIZE,
+			       SQFS_DEVBLK_SIZE);
+			compressor_print_available();
+			exit(EXIT_SUCCESS);
+		case 'V':
+			print_version("tar2sqfs");
+			exit(EXIT_SUCCESS);
+		default:
+			goto fail_arg;
+		}
+	}
+
+	if (cfg.num_jobs < 1)
+		cfg.num_jobs = 1;
+
+	if (cfg.max_backlog < 1)
+		cfg.max_backlog = 10 * cfg.num_jobs;
+
+	if (cfg.comp_extra != NULL && strcmp(cfg.comp_extra, "help") == 0) {
+		compressor_print_help(cfg.comp_id);
+		exit(EXIT_SUCCESS);
+	}
+
+	if (optind >= argc) {
+		fputs("Missing argument: squashfs image\n", stderr);
+		goto fail_arg;
+	}
+
+	cfg.filename = argv[optind++];
+
+	if (optind < argc) {
+		fputs("Unknown extra arguments specified.\n", stderr);
+		goto fail_arg;
+	}
+	return;
+fail_arg:
+	fputs("Try `tar2sqfs --help' for more information.\n", stderr);
+	exit(EXIT_FAILURE);
+}
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;
+}
diff --git a/bin/tar2sqfs/tar2sqfs.c b/bin/tar2sqfs/tar2sqfs.c
new file mode 100644
index 0000000..ae56e6b
--- /dev/null
+++ b/bin/tar2sqfs/tar2sqfs.c
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * tar2sqfs.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "tar2sqfs.h"
+
+int main(int argc, char **argv)
+{
+	int status = EXIT_FAILURE;
+	FILE *input_file = NULL;
+	sqfs_writer_t sqfs;
+
+	process_args(argc, argv);
+
+#ifdef _WIN32
+	_setmode(_fileno(stdin), _O_BINARY);
+	input_file = stdin;
+#else
+	input_file = freopen(NULL, "rb", stdin);
+#endif
+
+	if (input_file == NULL) {
+		perror("changing stdin to binary mode");
+		return EXIT_FAILURE;
+	}
+
+	memset(&sqfs, 0, sizeof(sqfs));
+	if (sqfs_writer_init(&sqfs, &cfg))
+		return EXIT_FAILURE;
+
+	if (process_tarball(input_file, &sqfs))
+		goto out;
+
+	if (fstree_post_process(&sqfs.fs))
+		goto out;
+
+	if (sqfs_writer_finish(&sqfs, &cfg))
+		goto out;
+
+	status = EXIT_SUCCESS;
+out:
+	sqfs_writer_cleanup(&sqfs, status);
+	return status;
+}
diff --git a/bin/tar2sqfs/tar2sqfs.h b/bin/tar2sqfs/tar2sqfs.h
new file mode 100644
index 0000000..a27a50b
--- /dev/null
+++ b/bin/tar2sqfs/tar2sqfs.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * tar2sqfs.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef TAR2SQFS_H
+#define TAR2SQFS_H
+
+#include "config.h"
+#include "common.h"
+#include "compat.h"
+#include "tar.h"
+
+#include <stdlib.h>
+#include <getopt.h>
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+
+#ifdef _WIN32
+#include <io.h>
+#endif
+
+/* options.c */
+extern bool dont_skip;
+extern bool keep_time;
+extern bool no_tail_pack;
+extern sqfs_writer_cfg_t cfg;
+extern char *root_becomes;
+
+void process_args(int argc, char **argv);
+
+/* process_tarball.c */
+int process_tarball(FILE *input_file, sqfs_writer_t *sqfs);
+
+#endif /* TAR2SQFS_H */