1 files changed, 157 insertions, 0 deletions
diff --git a/src/basic/percent-util.c b/src/basic/percent-util.c
new file mode 100644
index 0000000..cab9d0e
--- /dev/null
+++ b/src/basic/percent-util.c
@@ -0,0 +1,157 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "percent-util.h"
+#include "string-util.h"
+#include "parse-util.h"
+
+static int parse_parts_value_whole(const char *p, const char *symbol) {
+        const char *pc, *n;
+        int r, v;
+
+        pc = endswith(p, symbol);
+        if (!pc)
+                return -EINVAL;
+
+        n = strndupa_safe(p, pc - p);
+        r = safe_atoi(n, &v);
+        if (r < 0)
+                return r;
+        if (v < 0)
+                return -ERANGE;
+
+        return v;
+}
+
+static int parse_parts_value_with_tenths_place(const char *p, const char *symbol) {
+        const char *pc, *dot, *n;
+        int r, q, v;
+
+        pc = endswith(p, symbol);
+        if (!pc)
+                return -EINVAL;
+
+        dot = memchr(p, '.', pc - p);
+        if (dot) {
+                if (dot + 2 != pc)
+                        return -EINVAL;
+                if (dot[1] < '0' || dot[1] > '9')
+                        return -EINVAL;
+                q = dot[1] - '0';
+                n = strndupa_safe(p, dot - p);
+        } else {
+                q = 0;
+                n = strndupa_safe(p, pc - p);
+        }
+        r = safe_atoi(n, &v);
+        if (r < 0)
+                return r;
+        if (v < 0)
+                return -ERANGE;
+        if (v > (INT_MAX - q) / 10)
+                return -ERANGE;
+
+        v = v * 10 + q;
+        return v;
+}
+
+static int parse_parts_value_with_hundredths_place(const char *p, const char *symbol) {
+        const char *pc, *dot, *n;
+        int r, q, v;
+
+        pc = endswith(p, symbol);
+        if (!pc)
+                return -EINVAL;
+
+        dot = memchr(p, '.', pc - p);
+        if (dot) {
+                if (dot + 3 == pc) {
+                        /* Support two places after the dot */
+
+                        if (dot[1] < '0' || dot[1] > '9' || dot[2] < '0' || dot[2] > '9')
+                                return -EINVAL;
+                        q = (dot[1] - '0') * 10 + (dot[2] - '0');
+
+                } else if (dot + 2 == pc) {
+                        /* Support one place after the dot */
+
+                        if (dot[1] < '0' || dot[1] > '9')
+                                return -EINVAL;
+                        q = (dot[1] - '0') * 10;
+                } else
+                        /* We do not support zero or more than two places */
+                        return -EINVAL;
+
+                n = strndupa_safe(p, dot - p);
+        } else {
+                q = 0;
+                n = strndupa_safe(p, pc - p);
+        }
+        r = safe_atoi(n, &v);
+        if (r < 0)
+                return r;
+        if (v < 0)
+                return -ERANGE;
+        if (v > (INT_MAX - q) / 100)
+                return -ERANGE;
+
+        v = v * 100 + q;
+        return v;
+}
+
+int parse_percent_unbounded(const char *p) {
+        return parse_parts_value_whole(p, "%");
+}
+
+int parse_percent(const char *p) {
+        int v;
+
+        v = parse_percent_unbounded(p);
+        if (v > 100)
+                return -ERANGE;
+
+        return v;
+}
+
+int parse_permille_unbounded(const char *p) {
+        const char *pm;
+
+        pm = endswith(p, "‰");
+        if (pm)
+                return parse_parts_value_whole(p, "‰");
+
+        return parse_parts_value_with_tenths_place(p, "%");
+}
+
+int parse_permille(const char *p) {
+        int v;
+
+        v = parse_permille_unbounded(p);
+        if (v > 1000)
+                return -ERANGE;
+
+        return v;
+}
+
+int parse_permyriad_unbounded(const char *p) {
+        const char *pm;
+
+        pm = endswith(p, "‱");
+        if (pm)
+                return parse_parts_value_whole(p, "‱");
+
+        pm = endswith(p, "‰");
+        if (pm)
+                return parse_parts_value_with_tenths_place(p, "‰");
+
+        return parse_parts_value_with_hundredths_place(p, "%");
+}
+
+int parse_permyriad(const char *p) {
+        int v;
+
+        v = parse_permyriad_unbounded(p);
+        if (v > 10000)
+                return -ERANGE;
+
+        return v;
+}