Redoing the patch discussed below.
Using the direction that Tomo had suggested with some variations.
On 06/20/2010 05:01 AM, FUJITA Tomonori wrote:
> On Thu, 17 Jun 2010 16:19:43 +0300 (IDT)
> Alexander Nezhinsky <alexandern@xxxxxxxxxxxx> wrote:
>
>> When a numerical command line param value is out of range or contains garbage
>> (both tgtd and tgtadm), this remains unchecked in many cases.
>> In some of them 0 value will be used, which may lead to unpredicted or
>> "silently" faulty behavior.
>>
>> This fix defines a new function str_to_uit64() which uses strtoull() and
>> detects its errors properly, by checking 1) errno (range errors) and
>> 2) comparing endptr to the original argument (nun-numerical garbage);
>> must check both.
>>
>> str_to_uit64() is declared static twice, in tgtd.c and tgtadm.c, as
>> tgtadm does not uses util.c, where the natural place of this function
>> would be otherwise.
>>
>> It returns the converted integer value directly, while error is returned
>> through a pointer argument. Although the opposite arrangement may seem
>> intuitive, this one allows free casting of the returned value to various
>> types. Return type uint64 is choosen to cover all possible cases.
>> min and max arguments support range checking. To use the natural integer
>> ranges, use ULLONG_MAX, ULONG_MAX, USHRT_MAX etc.
>>
>> Signed-off-by: Alexander Nezhinsky <alexandern@xxxxxxxxxxxx>
>
> I'm for the strict checking however two comments.
>
> - casting a returned value looks ugly.
>
> - duplicating the same function isn't nice.
>
>
> How about something like this?
>
> diff --git a/usr/tgtadm.c b/usr/tgtadm.c
> index 28ed754..2282c86 100644
> --- a/usr/tgtadm.c
> +++ b/usr/tgtadm.c
> @@ -471,8 +471,8 @@ int main(int argc, char **argv)
> mode = str_to_mode(optarg);
> break;
> case 't':
> - tid = strtol(optarg, NULL, 10);
> - if (errno == EINVAL) {
> + tid = str_to_val(optarg, int, 0, INT_MAX, &rc);
> + if (rc == EINVAL) {
> eprintf("invalid tid '%s'\n", optarg);
> exit(EINVAL);
> }
> diff --git a/usr/util.h b/usr/util.h
> index 6e1fd6f..fc406b1 100644
> --- a/usr/util.h
> +++ b/usr/util.h
> @@ -156,4 +156,17 @@ struct signalfd_siginfo {
> };
> #endif
>
> +#define str_to_val(str, type, min, max, err_ptr) \
> +({ \
> + char *ptr; \
> + int ret = 0; \
> + typeof(type) v = strtoull(str, &ptr, 0); \
> + if (errno || ptr == str) \
> + ret = EINVAL; \
> + if (v < min|| v > max) \
> + ret = ERANGE; \
> + *err_ptr = ret; \
> + v; \
> +}) \
> +
> #endif
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