[hackers] [sbase] Make strtol() parsing even stricter in parseoffset() || FRIGN

[git]

commit 8be7c428636afe405ac6fe5fa1b09dbc9552bf75
Author:     FRIGN <d...@frign.de>
AuthorDate: Wed Sep 30 20:05:14 2015 +0200
Commit:     sin <s...@2f30.org>
CommitDate: Wed Sep 30 19:44:11 2015 +0100

    Make strtol() parsing even stricter in parseoffset()
    
    Be strict about what we pass to it and how we handle errors.
    The base-check is done by strtol anyway.
    Also improve error-reporting.

diff --git a/libutil/parseoffset.c b/libutil/parseoffset.c
index d12557f..37673da 100644
--- a/libutil/parseoffset.c
+++ b/libutil/parseoffset.c
@@ -1,5 +1,6 @@
 /* See LICENSE file for copyright and license details. */
 #include <ctype.h>
+#include <errno.h>
 #include <inttypes.h>
 #include <stdlib.h>
 #include <string.h>
@@ -9,25 +10,21 @@
 off_t
 parseoffset(const char *str)
 {
-       off_t res;
-       size_t scale = 1;
-       int base = 10;
+       off_t res, scale = 1;
        char *end;
 
-       if (!str || !*str) {
-               weprintf("parseoffset: empty string\n");
+       /* strictly check what strtol() usually would let pass */
+       if (!str || !*str || isspace(*str) || *str == '+' || *str == '-') {
+               weprintf("parseoffset %s: invalid value\n", str);
                return -1;
        }
 
-       /* bases */
-       if (!strncasecmp(str, "0x", strlen("0x"))) {
-               base = 16;
-       } else if (*str == '0') {
-               str++;
-               base = 8;
+       errno = 0;
+       res = strtol(str, &end, 0);
+       if (errno) {
+               weprintf("parseoffset %s: invalid value\n", str);
+               return -1;
        }
-
-       res = strtol(str, &end, base);
        if (res < 0) {
                weprintf("parseoffset %s: negative value\n", str);
                return -1;
@@ -49,7 +46,7 @@ parseoffset(const char *str)
                        scale = 1024L * 1024L * 1024L;
                        break;
                default:
-                       weprintf("parseoffset %s: invalid suffix\n", str);
+                       weprintf("parseoffset %s: invalid suffix '%s'\n", str, 
end);
                        return -1;
                }
        }