From a64417804f4c2b0425e167851d10854cf1f23e99 Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Date: Sat, 1 Jul 2023 12:41:56 +0200
Subject: Consolidate some of the stray integer parsers

There are several ad-hoc int/uint parsers scattered around the code,
add a single helper function for that task and replace the multiple
instances. A simple white-box test case is added for the utility
function.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 lib/util/src/parse_int.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 lib/util/src/parse_int.c

(limited to 'lib/util/src/parse_int.c')

diff --git a/lib/util/src/parse_int.c b/lib/util/src/parse_int.c
new file mode 100644
index 0000000..1bca528
--- /dev/null
+++ b/lib/util/src/parse_int.c
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * alloc.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "util/parse.h"
+#include "sqfs/error.h"
+
+#include <ctype.h>
+
+int parse_uint(const char *in, size_t len, size_t *diff,
+	       sqfs_u64 vmin, sqfs_u64 vmax, sqfs_u64 *out)
+{
+	/* init result */
+	if (diff != NULL)
+		*diff = 0;
+	*out = 0;
+
+	/* sequence has at least 1 digit */
+	if (len == 0 || !isdigit(*in))
+		return SQFS_ERROR_CORRUPTED;
+
+	/* parse sequence */
+	while (len > 0 && isdigit(*in)) {
+		sqfs_u64 x = *(in++) - '0';
+		--len;
+
+		if (diff != NULL)
+			++(*diff);
+
+		if ((*out) >= (0xFFFFFFFFFFFFFFFFULL / 10ULL))
+			return SQFS_ERROR_OVERFLOW;
+
+		(*out) *= 10;
+
+		if ((*out) > (0xFFFFFFFFFFFFFFFFULL - x))
+			return SQFS_ERROR_OVERFLOW;
+
+		(*out) += x;
+	}
+
+	/* range check */
+	if ((vmin != vmax) && ((*out < vmin) || (*out > vmax)))
+		return SQFS_ERROR_OUT_OF_BOUNDS;
+
+	/* if diff is not used, entire  must have been processed */
+	if (diff == NULL && (len > 0 && *in != '\0'))
+		return SQFS_ERROR_CORRUPTED;
+
+	return 0;
+}
+
+
+int parse_int(const char *in, size_t len, size_t *diff,
+	      sqfs_s64 vmin, sqfs_s64 vmax, sqfs_s64 *out)
+{
+	bool negative = false;
+	sqfs_u64 temp;
+	int ret;
+
+	if (len > 0 && *in == '-') {
+		++in;
+		--len;
+		negative = true;
+	}
+
+	ret = parse_uint(in, len, diff, 0, 0, &temp);
+	if (ret)
+		return ret;
+
+	if (temp >= 0x7FFFFFFFFFFFFFFFULL)
+		return SQFS_ERROR_OVERFLOW;
+
+	if (negative) {
+		if (diff != NULL)
+			(*diff) += 1;
+		*out = -((sqfs_s64)temp);
+	} else {
+		*out = (sqfs_s64)temp;
+	}
+
+	if (vmin != vmax && ((*out < vmin) || (*out > vmax)))
+		return SQFS_ERROR_OUT_OF_BOUNDS;
+
+	return 0;
+}
-- 
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