On Friday 2010-08-06 10:00, Luciano Coelho wrote: >> >+ buf[length - 1] = '\0'; >> >+ >> >+ if (strict_strtoull(buf, 0, &value) != 0) >> >+ return -EINVAL; >> >+ >> >+ if (value > (u32) value) >> >+ return -EINVAL; >> >> Is it possible to use just strict_strtoul? > >Not easily. I found that there is a bug in strtoul (and strtoull for >that matter) that causes the long to overflow if there are valid digits >after the maximum possible digits for the base. For example if you try >to strtoul 0xfffffffff (with 9 f's) the strtoul will overflow and come >up with a bogus result. I see. Strange that no one has adressed this yet - I mean, writing a just-too-large value into a procfs/sysfs file and thus effectively causing a bogus value to be actually written isn't quite so thrilling as things go haywire. >I can't easily truncate the string to avoid >this problem, because with decimal or octal, the same valid value would >take more spaces. I could do some magic here, checking whether it's a >hex, dec or oct and truncate appropriately, but that would be very ugly. > >So the simplest way I came up with was to use strtoull and return >-EINVAL if the value exceeds 32 bits. ;) If I read strtoul(3) right, ERANGE is used for "out of range". >> Since the condition value (cdmark) was thought of an nfmark-style thing, >> would it perhaps make sense to model it after it >> >> return (var->value & ~info->mask) ^ info->value; >> >> Other opinions? > >I think it's nicer to have it as a normal equals here for now and then >extend the match with more operations. We can later add, for example, >an --and option to the condition match in order to do other kinds of >binary operations. It would be more flexible this way because we could >use several different types of comparisons, wouldn't it? And in the >target we could have several different types of operations. Indeed. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
