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Date:      Tue, 26 Nov 2013 13:02:07 +1100
From:      Mark Andrews <marka@isc.org>
To:        Michael Butler <imb@protected-networks.net>
Cc:        freebsd-stable@freebsd.org
Subject:   Re: ipfw table add problem
Message-ID:  <20131126020208.37AF9AD4D2C@rock.dv.isc.org>
In-Reply-To: Your message of "Mon, 25 Nov 2013 20:30:57 -0500." <5293F9D1.2030800@protected-networks.net>
References:  <CAAcX-AGDZbFn5RmhLBBn2PPWRPcsFUnea5MgTc7nuXGD8Ge53A@mail.gmail.com> <52911993.8010108@ipfw.ru> <CAAcX-AEt_i8RUfmMy6WLnER0X=uLk5A1=oj911k-nyMJEghRLw@mail.gmail.com> <529259DE.2040701@FreeBSD.org> <20131125152238.S78756@sola.nimnet.asn.au> <1385391778.1220.4.camel@revolution.hippie.lan> <20131126001806.27951AD3DBF@rock.dv.isc.org> <5293EBD6.8010009@protected-networks.net> <20131126003941.1ACD9AD41B4@rock.dv.isc.org> <5293F9D1.2030800@protected-networks.net>

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I remember incorrectly, the actual change was this one.

revision 1.8
date: 2001-07-16 13:22:24 +1000;  author: marka;  state: Exp;  lines: +4 -2;
1242.   [bug]           inet_pton() failed to reject octal input.

Index: inet/inet_pton.c
===================================================================
RCS file: /proj/cvs/prod/bind8/src/lib/inet/inet_pton.c,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -r1.7 -r1.8
--- inet/inet_pton.c	13 Oct 1999 16:39:28 -0000	1.7
+++ inet/inet_pton.c	16 Jul 2001 03:22:24 -0000	1.8
@@ -16,7 +16,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static const char rcsid[] = "$Id: inet_pton.c,v 1.7 1999-10-13 16:39:28 vixie Exp $";
+static const char rcsid[] = "$Id: inet_pton.c,v 1.8 2001-07-16 03:22:24 marka Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include "port_before.h"
@@ -95,10 +95,12 @@
 		if ((pch = strchr(digits, ch)) != NULL) {
 			u_int new = *tp * 10 + (pch - digits);
 
+			if (saw_digit && *tp == 0)
+				return (0);
 			if (new > 255)
 				return (0);
 			*tp = new;
-			if (! saw_digit) {
+			if (!saw_digit) {
 				if (++octets > 4)
 					return (0);
 				saw_digit = 1;

Now if you want to make it accept 0+[89][0-9]* go ahead but
0+[01234567][01234567]* need to be rejected when the inet_aton
accepts octal and hexadecimal.  Having different routines return
different values for 070.070.070.070 is infintitely worse than
having 070.070.070.070 be rejected by one.  Yes there is a small
subset of 8 octal inputs that match decimal input for which there
is no harm.  I'm much more worried about the ones that do differ.

Mark

In message <5293F9D1.2030800@protected-networks.net>, Michael Butler writes:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On 11/25/13 19:39, Mark Andrews wrote:
> 
> >> When inet_pton() implementations have been rejecting leading zero's since
> >> they were first written their can't be a POLA.  There can be a difference
> >> but not a POLA.  To make is now accept a leading zero would be a POLA as
> >> there is code that depends on leading zeros being rejected by it.
> 
> History disagrees with you; from the BIND 4 sources:
> 
> /* This is from the BIND 4.9.4 release, modified to compile by itself */
> 
> /* Copyright (c) 1996 by Internet Software Consortium.
>  *
>  * Permission to use, copy, modify, and distribute this software for any
>  * purpose with or without fee is hereby granted, provided that the above
>  * copyright notice and this permission notice appear in all copies.
>  *
>  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
> DISCLAIMS
>  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
> WARRANTIES
>  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
>  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
>  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
>  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
>  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
> OF THIS
>  * SOFTWARE.
>  */
> 
> #if defined(LIBC_SCCS) && !defined(lint)
> static char rcsid[] = "$Id: inet_pton.c,v 8.6 1996/06/26 23:17:26 vixie
> Exp $";
> #endif /* LIBC_SCCS and not lint */
> 
>  [ .. snip .. ]
> 
> /* int
>  * inet_pton4(src, dst)
>  *	like inet_aton() but without all the hexadecimal and shorthand.
>  * return:
>  *	1 if `src' is a valid dotted quad, else 0.
>  * notice:
>  *	does not touch `dst' unless it's returning 1.
>  * author:
>  *	Paul Vixie, 1996.
>  */
> static int
> inet_pton4(src, dst)
> 	const char *src;
> 	u_char *dst;
> {
> 	static const char digits[] = "0123456789";
> 	int saw_digit, octets, ch;
> 	u_char tmp[INADDRSZ], *tp;
> 
> 	saw_digit = 0;
> 	octets = 0;
> 	*(tp = tmp) = 0;
> 	while ((ch = *src++) != '\0') {
> 		const char *pch;
> 
> 		if ((pch = strchr(digits, ch)) != NULL) {
> 			u_int new = *tp * 10 + (pch - digits);
> 
> 			if (new > 255)
> 				return (0);
> 			*tp = new;
> 			if (! saw_digit) {
> 				if (++octets > 4)
> 					return (0);
> 				saw_digit = 1;
> 			}
> 		} else if (ch == '.' && saw_digit) {
> 			if (octets == 4)
> 				return (0);
> 			*++tp = 0;
> 			saw_digit = 0;
> 		} else
> 			return (0);
> 	}
> 	if (octets < 4)
> 		return (0);
> 	/* bcopy(tmp, dst, INADDRSZ); */
> 	memcpy(dst, tmp, INADDRSZ);
> 	return (1);
> }
> 
> Note especially that at some time after 1996, an additional two lines
> were added and the man page not updated to reflect their addition.
> 
> Above the test "(new > 255)" these lines were added:
> 
>                         if (saw_digit && *tp == 0)
>                                 return (0);
> 
>  .. and which now causes this confusion.
> 
> Either the code or the man page are wrong,
> 
> 	imb
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.15 (FreeBSD)
> 
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> zrkAmwSXukkcAhAKKfteEuFRe7tbTqnT
> =1JzH
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-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka@isc.org



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