From: Phil Sutter Date: Fri, 25 Nov 2016 17:52:55 +0000 (+0100) Subject: nft_ipv{4,6}_xlate: Respect prefix lengths X-Git-Tag: v1.6.1~13 X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=f1cd86ddcf1726b91aedb9ef916b380edc8c2b61;p=thirdparty%2Fiptables.git nft_ipv{4,6}_xlate: Respect prefix lengths This was an annoying bug in the translator since it silently dropped crucial information which is easily overlooked: | $ iptables-translate -A INPUT -s 192.168.0.0/24 -j ACCEPT | nft add rule ip filter INPUT ip saddr 192.168.0.0 counter accept | $ ip6tables-translate -A INPUT -s feed:babe::/64 -j ACCEPT | nft add rule ip6 filter INPUT ip6 saddr feed:babe:: counter accept To my surprise, this fix works really well in all kinds of situations: | $ iptables-translate -A INPUT -s 1.2.3.4/0 -j ACCEPT | nft add rule ip filter INPUT counter accept | | $ iptables-translate -A INPUT -s 1.2.3.4/23 -j ACCEPT | nft add rule ip filter INPUT ip saddr 1.2.2.0/23 counter accept | | $ iptables-translate -A INPUT -s 1.2.3.4/24 -j ACCEPT | nft add rule ip filter INPUT ip saddr 1.2.3.0/24 counter accept | | $ iptables-translate -A INPUT -s 1.2.3.4/32 -j ACCEPT | nft add rule ip filter INPUT ip saddr 1.2.3.4 counter accept | | $ iptables-translate -A INPUT -s 1.2.3.4/255.255.0.0 -j ACCEPT | nft add rule ip filter INPUT ip saddr 1.2.0.0/16 counter accept Ditto for IPv6. Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- diff --git a/iptables/nft-ipv4.c b/iptables/nft-ipv4.c index 295dd425..52b1bed2 100644 --- a/iptables/nft-ipv4.c +++ b/iptables/nft-ipv4.c @@ -471,14 +471,16 @@ static int nft_ipv4_xlate(const void *data, struct xt_xlate *xl) } if (cs->fw.ip.src.s_addr != 0) { - xt_xlate_add(xl, "ip saddr %s%s ", + xt_xlate_add(xl, "ip saddr %s%s%s ", cs->fw.ip.invflags & IPT_INV_SRCIP ? "!= " : "", - inet_ntoa(cs->fw.ip.src)); + inet_ntoa(cs->fw.ip.src), + xtables_ipmask_to_numeric(&cs->fw.ip.smsk)); } if (cs->fw.ip.dst.s_addr != 0) { - xt_xlate_add(xl, "ip daddr %s%s ", + xt_xlate_add(xl, "ip daddr %s%s%s ", cs->fw.ip.invflags & IPT_INV_DSTIP ? "!= " : "", - inet_ntoa(cs->fw.ip.dst)); + inet_ntoa(cs->fw.ip.dst), + xtables_ipmask_to_numeric(&cs->fw.ip.dmsk)); } ret = xlate_matches(cs, xl); diff --git a/iptables/nft-ipv6.c b/iptables/nft-ipv6.c index 8bebf6be..c475b8e9 100644 --- a/iptables/nft-ipv6.c +++ b/iptables/nft-ipv6.c @@ -387,6 +387,7 @@ static void nft_ipv6_save_counters(const void *data) } static void xlate_ipv6_addr(const char *selector, const struct in6_addr *addr, + const struct in6_addr *mask, int invert, struct xt_xlate *xl) { char addr_str[INET6_ADDRSTRLEN]; @@ -395,7 +396,8 @@ static void xlate_ipv6_addr(const char *selector, const struct in6_addr *addr, return; inet_ntop(AF_INET6, addr, addr_str, INET6_ADDRSTRLEN); - xt_xlate_add(xl, "%s %s%s ", selector, invert ? "!= " : "", addr_str); + xt_xlate_add(xl, "%s %s%s%s ", selector, invert ? "!= " : "", addr_str, + xtables_ip6mask_to_numeric(mask)); } static int nft_ipv6_xlate(const void *data, struct xt_xlate *xl) @@ -425,9 +427,9 @@ static int nft_ipv6_xlate(const void *data, struct xt_xlate *xl) } } - xlate_ipv6_addr("ip6 saddr", &cs->fw6.ipv6.src, + xlate_ipv6_addr("ip6 saddr", &cs->fw6.ipv6.src, &cs->fw6.ipv6.smsk, cs->fw6.ipv6.invflags & IP6T_INV_SRCIP, xl); - xlate_ipv6_addr("ip6 daddr", &cs->fw6.ipv6.dst, + xlate_ipv6_addr("ip6 daddr", &cs->fw6.ipv6.dst, &cs->fw6.ipv6.dmsk, cs->fw6.ipv6.invflags & IP6T_INV_DSTIP, xl); ret = xlate_matches(cs, xl);