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Diffstat (limited to 'lib/tar/read_sparse_map_new.c')
-rw-r--r--lib/tar/read_sparse_map_new.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/lib/tar/read_sparse_map_new.c b/lib/tar/read_sparse_map_new.c
new file mode 100644
index 0000000..246f8a5
--- /dev/null
+++ b/lib/tar/read_sparse_map_new.c
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * read_sparse_map_new.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "internal.h"
+
+static int decode(const char *str, size_t len, size_t *out)
+{
+ size_t count = 0;
+
+ *out = 0;
+
+ while (count < len && isdigit(*str)) {
+ if (*out > 0xFFFFFFFFFFFFFFFFUL / 10)
+ return -1;
+ *out = (*out) * 10 + (*(str++) - '0');
+ ++count;
+ }
+
+ if (count == 0 || count == len)
+ return 0;
+
+ return (*str == '\n') ? ((int)count + 1) : -1;
+}
+
+sparse_map_t *read_gnu_new_sparse(FILE *fp, tar_header_decoded_t *out)
+{
+ sparse_map_t *last = NULL, *list = NULL, *ent = NULL;
+ size_t i, count, value;
+ char buffer[1024];
+ int diff, ret;
+
+ if (read_retry("reading GNU sparse map", fp, buffer, 512))
+ return NULL;
+
+ diff = decode(buffer, 512, &count);
+ if (diff <= 0)
+ goto fail_format;
+
+ out->record_size -= 512;
+
+ for (i = 0; i < (count * 2); ++i) {
+ ret = decode(buffer + diff, 512 - diff, &value);
+ if (ret < 0)
+ goto fail_format;
+
+ if (ret > 0) {
+ diff += ret;
+ } else {
+ if (read_retry("reading GNU sparse map", fp,
+ buffer + 512, 512)) {
+ return NULL;
+ }
+
+ ret = decode(buffer + diff, 1024 - diff, &value);
+ if (ret <= 0)
+ goto fail_format;
+
+ memcpy(buffer, buffer + 512, 512);
+ diff = diff + ret - 512;
+ out->record_size -= 512;
+ }
+
+ if ((i & 0x01) == 0) {
+ ent = calloc(1, sizeof(*ent));
+ if (ent == NULL)
+ goto fail_errno;
+
+ if (list == NULL) {
+ list = last = ent;
+ } else {
+ last->next = ent;
+ last = ent;
+ }
+
+ ent->offset = value;
+ } else {
+ ent->count = value;
+ }
+ }
+
+ return list;
+fail_errno:
+ perror("parsing GNU 1.0 style sparse file record");
+ goto fail;
+fail_format:
+ fputs("Malformed GNU 1.0 style sparse file map.\n", stderr);
+ goto fail;
+fail:
+ free_sparse_list(list);
+ return NULL;
+}