archive: Use libarchive to check for tar contents

Stop using binary tar to check for tar contents. Use libarchive instead

Signed-off-by: Otavio Pontes <otavio.pontes@intel.com>

src/helpers.c

@@ -906,58 +906,14 @@ int link_or_rename(const char *orig, const char *dest)
 	return 0;
 }
 
-/* list the tarfile content, and verify it contains only one line equal to the expected hash.
- * loop through all the content to detect the case where archive contains more than one file.
- */
-static int check_tarfile_content(struct file *file, const char *tarfilename)
+static int check_single_file_tarball(const char *tarfilename, struct file *file)
 {
 	int err;
-	char *tarcommand;
-	FILE *tar;
-	int count = 0;
+	char *filename;
 
-	string_or_die(&tarcommand, TAR_COMMAND " -tf %s/download/%s.tar 2> /dev/null", state_dir, file->hash);
-
-	err = access(tarfilename, R_OK);
-	if (err) {
-		goto free_tarcommand;
-	}
-
-	tar = popen(tarcommand, "r");
-	if (tar == NULL) {
-		err = -1;
-		goto free_tarcommand;
-	}
-
-	while (!feof(tar)) {
-		char *c;
-		char buffer[PATH_MAXLEN];
-
-		if (fgets(buffer, PATH_MAXLEN, tar) == NULL) {
-			if (count != 1) {
-				err = -1;
-			}
-			break;
-		}
-
-		c = strchr(buffer, '\n');
-		if (c) {
-			*c = 0;
-		}
-		if (c && (c != buffer) && (*(c - 1) == '/')) {
-			/* strip trailing '/' from directory tar */
-			*(c - 1) = 0;
-		}
-		if (strcmp(buffer, file->hash) != 0) {
-			err = -1;
-			break;
-		}
-		count++;
-	}
-
-	pclose(tar);
-free_tarcommand:
-	free_string(&tarcommand);
+	string_or_die(&filename, "%s%s", file->hash, file->is_dir ? "/" : "");
+	err = archives_check_single_file_tarball(tarfilename, filename);
+	free(filename);
 
 	return err;
 }
@@ -1004,7 +960,7 @@ int untar_full_download(void *data)
 	}
 	free_string(&tar_dotfile);
 
-	err = check_tarfile_content(file, tarfile);
+	err = check_single_file_tarball(tarfile, file);
 	if (err) {
 		goto exit;
 	}

src/lib/archives.c

@@ -86,6 +86,43 @@ static int copy_data(struct archive *ar, struct archive *aw)
 	return 0;
 }
 
+static int archive_from_filename(struct archive **a, const char *tarfile)
+{
+	int r = 0;
+
+	if (!a) {
+		return -EINVAL;
+	}
+
+	*a = archive_read_new();
+	if (!*a) {
+		return -ENOMEM;
+	}
+
+	r = archive_read_support_format_tar(*a);
+	if (_archive_check_err(*a, r)) {
+		goto error;
+	}
+
+	r = archive_read_support_filter_all(*a);
+	if (_archive_check_err(*a, r)) {
+		goto error;
+	}
+
+	r = archive_read_open_filename(*a, tarfile, 10240);
+	if (_archive_check_err(*a, r)) {
+		/* could not open archive for read */
+		goto error;
+	}
+
+	return 0;
+
+error:
+	archive_read_close(*a);
+	archive_read_free(*a);
+	return r;
+}
+
 int archives_extract_to(const char *tarfile, const char *outputdir)
 {
 	struct archive *a, *ext;
@@ -104,15 +141,9 @@ int archives_extract_to(const char *tarfile, const char *outputdir)
 	flags |= ARCHIVE_EXTRACT_SECURE_NODOTDOT;
 
 	/* set up read */
-	a = archive_read_new();
-	r = archive_read_support_format_tar(a);
-	if (_archive_check_err(a, r)) {
-		goto out_read;
-	}
-
-	r = archive_read_support_filter_all(a);
-	if (_archive_check_err(a, r)) {
-		goto out_read;
+	r = archive_from_filename(&a, tarfile);
+	if (r < 0) {
+		return r;
 	}
 
 	/* set up write */
@@ -127,12 +158,6 @@ int archives_extract_to(const char *tarfile, const char *outputdir)
 		goto out;
 	}
 
-	r = archive_read_open_filename(a, tarfile, 10240);
-	if (_archive_check_err(a, r)) {
-		/* could not open archive for read */
-		goto out;
-	}
-
 	/* read and write loop */
 	for (;;) {
 		r = archive_read_next_header(a, &entry);
@@ -191,8 +216,37 @@ out:
 	 * error. If 'goto out' is called, we already have an error we are handling
 	 * so don't overwrite that returncode. */
 	archive_write_free(ext);
-out_read:
 	archive_read_close(a);
 	archive_read_free(a);
 	return r;
 }
+
+int archives_check_single_file_tarball(const char *tarfilename, const char *file)
+{
+	struct archive *a;
+	struct archive_entry *entry;
+	int r;
+	bool found = false;
+
+	/* set up read */
+	r = archive_from_filename(&a, tarfilename);
+	if (r < 0) {
+		return r;
+	}
+
+	while (archive_read_next_header(a, &entry) == ARCHIVE_OK) {
+		if (!found && strcmp(archive_entry_pathname(entry), file) == 0) {
+			found = true;
+		} else {
+			found = false;
+			goto end;
+		}
+		archive_read_data_skip(a);
+	}
+
+end:
+	archive_read_close(a);
+	archive_read_free(a);
+
+	return found ? 0 : -ENOENT;
+}

src/lib/archives.h

@@ -11,6 +11,12 @@ extern "C" {
  */
 int archives_extract_to(const char *tarfile, const char *outputdir);
 
+/*
+ * Check if this tarball is valid and if it contains only one file with the
+ * specified name.
+ */
+int archives_check_single_file_tarball(const char *tarfilename, const char *file);
+
 #ifdef __cplusplus
 }
 #endif

src/swupd.h

@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "lib/archives.h"
 #include "lib/formatter_json.h"
 #include "lib/list.h"
 #include "lib/log.h"
@@ -18,7 +19,6 @@
 #include "lib/progress.h"
 #include "lib/strings.h"
 #include "lib/sys.h"
-#include "lib/archives.h"
 #include "manifest.h"
 #include "scripts.h"
 #include "swupd_curl.h"