1 files changed, 89 insertions, 0 deletions
diff --git a/lib/tar/read_sparse_map_old.c b/lib/tar/read_sparse_map_old.c
new file mode 100644
index 0000000..c0b2d0d
--- /dev/null
+++ b/lib/tar/read_sparse_map_old.c
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "internal.h"
+
+sparse_map_t *read_gnu_old_sparse(int fd, tar_header_t *hdr)
+{
+	sparse_map_t *list = NULL, *end = NULL, *node;
+	gnu_sparse_t sph;
+	uint64_t off, sz;
+	ssize_t ret;
+	int i;
+
+	for (i = 0; i < 4; ++i) {
+		if (!isdigit(hdr->tail.gnu.sparse[i].offset[0]))
+			break;
+		if (!isdigit(hdr->tail.gnu.sparse[i].numbytes[0]))
+			break;
+
+		if (read_octal(hdr->tail.gnu.sparse[i].offset,
+			       sizeof(hdr->tail.gnu.sparse[i].offset), &off))
+			goto fail;
+		if (read_octal(hdr->tail.gnu.sparse[i].numbytes,
+			       sizeof(hdr->tail.gnu.sparse[i].numbytes), &sz))
+			goto fail;
+
+		node = calloc(1, sizeof(*node));
+		if (node == NULL)
+			goto fail_errno;
+
+		node->offset = off;
+		node->count = sz;
+
+		if (list == NULL) {
+			list = end = node;
+		} else {
+			end->next = node;
+			end = node;
+		}
+	}
+
+	if (hdr->tail.gnu.isextended == 0)
+		return list;
+
+	do {
+		ret = read_retry(fd, &sph, sizeof(sph));
+		if (ret < 0)
+			goto fail_errno;
+		if ((size_t)ret < sizeof(sph))
+			goto fail_eof;
+
+		for (i = 0; i < 21; ++i) {
+			if (!isdigit(sph.sparse[i].offset[0]))
+				break;
+			if (!isdigit(sph.sparse[i].numbytes[0]))
+				break;
+
+			if (read_octal(sph.sparse[i].offset,
+				       sizeof(sph.sparse[i].offset), &off))
+				goto fail;
+			if (read_octal(sph.sparse[i].numbytes,
+				       sizeof(sph.sparse[i].numbytes), &sz))
+				goto fail;
+
+			node = calloc(1, sizeof(*node));
+			if (node == NULL)
+				goto fail_errno;
+
+			node->offset = off;
+			node->count = sz;
+
+			if (list == NULL) {
+				list = end = node;
+			} else {
+				end->next = node;
+				end = node;
+			}
+		}
+	} while (sph.isextended != 0);
+
+	return list;
+fail_eof:
+	fputs("parsing GNU sparse header: unexpected end of file", stderr);
+	goto fail;
+fail_errno:
+	perror("parsing GNU sparse header");
+	goto fail;
+fail:
+	free_sparse_list(list);
+	return NULL;
+}