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

From: <git_AT_suckless.org>
Date: Wed, 30 Sep 2015 20:44:19 +0200 (CEST)

commit 8be7c428636afe405ac6fe5fa1b09dbc9552bf75
Author: FRIGN <dev_AT_frign.de>
AuthorDate: Wed Sep 30 20:05:14 2015 +0200
Commit: sin <sin_AT_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
_AT_@ -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>
_AT_@ -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;
_AT_@ -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;
                 }
         }
Received on Wed Sep 30 2015 - 20:44:19 CEST