Date: Thu, 3 Oct 2002 12:55:15 -0700 From: "Crist J. Clark" <crist.clark@attbi.com> To: Artem Okounev <aokounev@yahoo.com> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: inet_aton() Bug or feature? Message-ID: <20021003195515.GA92263@blossom.cjclark.org> In-Reply-To: <1136947159.20021003160026@yahoo.com> References: <1136947159.20021003160026@yahoo.com>
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On Thu, Oct 03, 2002 at 04:00:26PM +0300, Artem Okounev wrote:
> To my great surprise I found out that:
> ping 192.168.0.26,
> ping 192.168.0.032,
> and even ping 192.168.0.0x1a - all correct commands doing
> the same thing: pinging 192.168.0.26.
Yep.
> That was my problem. IP addresses was stored in text file in
> the form of 192.168.000.032, and after issuing command: arp
> - -s 192.168.000.032 xx:xx:xx:xx:xx:xx (which actually was
> treated as arp -s 192.168.0.26) I had a great headache.
That should be pretty easy to fix in your script.
> After some investigation I found that both ping and arp use
> inet_aton() libc call to interpret their command arguments
> into network format. Futher, inet_aton() uses
> strtoul(c,&endptr, 0) for each octet in IP address to
> convert string representation of number to unsigned long.
>
> Why not to use strtoul(x, x, 10) and fix aforementioned
> confusing thing with arp/ping/...? Does anybody write
> command arguments to ping using octal or hex format :)?
>
> I am not hacker. Just curious.
This is a feature not a bug since it is documented in inet_aton(3),
All numbers supplied as ``parts'' in a `.' notation may be decimal,
octal, or hexadecimal, as specified in the C language (i.e., a leading 0x
or 0X implies hexadecimal; otherwise, a leading 0 implies octal; other-
wise, the number is interpreted as decimal).
People use this notation all of the time,
# ifconfig if0 172.16.1.10 netmask 0xffffff00
^^^^^^^^^^
--
Crist J. Clark | cjclark@alum.mit.edu
| cjclark@jhu.edu
http://people.freebsd.org/~cjc/ | cjc@freebsd.org
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