From 9bbf903d6e35fe9fa1ae70e440829187a09b523a Mon Sep 17 00:00:00 2001 From: "/C=DE/ST=Berlin/L=Berlin/O=Netfilter Project/OU=Development/CN=kaber/emailAddress=kaber@netfilter.org" Date: Mon, 10 Jul 2006 04:52:56 +0000 Subject: [PATCH] iptables: handle cidr notation more sanely (Phil Oester ) 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 --- iptables.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/iptables.c b/iptables.c index ea0eae3..7814986 100644 --- a/iptables.c +++ b/iptables.c @@ -583,6 +583,34 @@ addr_to_host(const struct in_addr *addr) 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 @@ parse_hostnetworkmask(const char *name, struct in_addr **addrpp, 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); -- cgit v1.2.3