From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Oester Subject: [PATCH] iptables: handle cidr notation more sanely Date: Sun, 9 Jul 2006 15:28:18 -0700 Message-ID: <20060709222818.GA23200@linuxace.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="8t9RHnE3ZwKMSgU+" Return-path: To: netfilter-devel@lists.netfilter.org Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-devel-bounces@lists.netfilter.org Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netfilter-devel.vger.kernel.org --8t9RHnE3ZwKMSgU+ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline At present, a command such as iptables -A foo -s 10.10/16 will interpret 10.10/16 as 10.0.0.10/16, and after applying the mask end up with 10.0.0.0/16, which likely isn't what the user intended. Yet some people do expect 10.10 (without the cidr notation) to end up as 10.0.0.10. The below patch should satisfy all parties. It zero pads the missing octets only in the cidr case, leaving the IP untouched otherwise. This resolves bug #422 Phil --8t9RHnE3ZwKMSgU+ Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=patch-cidr diff -ru ipt-orig/iptables.c ipt-new/iptables.c --- ipt-orig/iptables.c 2006-04-21 05:04:51.000000000 -0700 +++ ipt-new/iptables.c 2006-07-09 15:15:15.000000000 -0700 @@ -583,6 +583,34 @@ return (char *) NULL; } +static void +pad_cidr(char *cidr) +{ + char *p, *q; + unsigned int onebyte; + int i, j; + char buf[20]; + + /* copy dotted string, because we need to modify it */ + strncpy(buf, cidr, sizeof(buf) - 1); + buf[sizeof(buf) - 1] = '\0'; + + p = buf; + for (i = 0; i <= 3; i++) { + if ((q = strchr(p, '.')) == NULL) + break; + *q = '\0'; + if (string_to_number(p, 0, 255, &onebyte) == -1) + return; + p = q + 1; + } + + /* pad remaining octets with zeros */ + for (j = i; j < 3; j++) { + strcat(cidr, ".0"); + } +} + /* * All functions starting with "parse" should succeed, otherwise * the program fails. @@ -651,6 +679,8 @@ if ((p = strrchr(buf, '/')) != NULL) { *p = '\0'; addrp = parse_mask(p + 1); + if (strrchr(p + 1, '.') == NULL) + pad_cidr(buf); } else addrp = parse_mask(NULL); inaddrcpy(maskp, addrp); --8t9RHnE3ZwKMSgU+--