src: add safe_strtoull for safe string to number conversion

Add safe_strtoull to validate the execution of strtoull.
Definining the base of the number is required becase partition
codes are base 16 but they lack the 0x prefix.

Replace uses of atoi and strtoull/strtoul and log the conversion
errors.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/utils.c b/src/utils.c
index d49a9ac..2607fc6 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -7,7 +7,12 @@
  * (at your option) any later version.
  */
 
+
 #include <ctype.h>
+#include <errno.h>
+#include <assert.h>
+#include <limits.h>
+#include <stdlib.h>
 #include "utils.h"
 
 void str_toupper(char *str)
@@ -29,3 +34,26 @@ void str_tolower(char *str)
                c++;
        }
 }
+
+int safe_strtoull(const char *str, uint64_t *out_value, int base, uint64_t max)
+{
+        char *endptr = NULL;
+        uint64_t result;
+        errno = 0;
+
+        assert(str != NULL && out_value != NULL);
+
+        if (str[0] == '-')
+                return -1;
+
+        result = strtoull(str, &endptr, base);
+
+        if (endptr == str ||
+            *endptr != '\0' ||
+            (errno == ERANGE && result == ULLONG_MAX) ||
+            result > max)
+                return -1;
+
+        *out_value = result;
+        return 0;
+}