From bb01e33d3828d08cd77cc3c9664b2a995ee150cc Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 2 Jun 2021 19:57:37 +0200 Subject: extensions: libxt_connlimit: add translation This patch adds a translation for connlimit matches which requires the definition of a set and the family context (either IPv4 or IPv6) which is required to display the netmask accordingly. Signed-off-by: Pablo Neira Ayuso --- extensions/libxt_connlimit.c | 49 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) (limited to 'extensions/libxt_connlimit.c') diff --git a/extensions/libxt_connlimit.c b/extensions/libxt_connlimit.c index a569f86a..118faea5 100644 --- a/extensions/libxt_connlimit.c +++ b/extensions/libxt_connlimit.c @@ -2,6 +2,8 @@ #include #include #include +#include + #include enum { @@ -183,6 +185,51 @@ static void connlimit_save6(const void *ip, const struct xt_entry_match *match) } } +static int connlimit_xlate(struct xt_xlate *xl, + const struct xt_xlate_mt_params *params) +{ + const struct xt_connlimit_info *info = (const void *)params->match->data; + static uint32_t connlimit_id; + char netmask[128] = {}; + char addr[64] = {}; + uint32_t mask; + + switch (xt_xlate_get_family(xl)) { + case AF_INET: + mask = count_bits4(info->v4_mask); + if (mask != 32) { + struct in_addr *in = (struct in_addr *)&info->v4_mask; + + inet_ntop(AF_INET, in, addr, sizeof(addr)); + snprintf(netmask, sizeof(netmask), "and %s ", addr); + } + break; + case AF_INET6: + mask = count_bits6(info->v6_mask); + if (mask != 128) { + struct in6_addr *in6 = (struct in6_addr *)&info->v6_mask; + + inet_ntop(AF_INET6, in6, addr, sizeof(addr)); + snprintf(netmask, sizeof(netmask), "and %s ", addr); + } + break; + default: + return 0; + } + + xt_xlate_set_add(xl, "connlimit%u { type ipv4_addr; flags dynamic; }", + connlimit_id); + xt_xlate_rule_add(xl, "add @connlimit%u { %s %s %sct count %s%u }", + connlimit_id++, + xt_xlate_get_family(xl) == AF_INET ? "ip" : "ip6", + info->flags & XT_CONNLIMIT_DADDR ? "daddr" : "saddr", + netmask, + info->flags & XT_CONNLIMIT_INVERT ? "" : "over ", + info->limit); + + return 1; +} + static struct xtables_match connlimit_mt_reg[] = { { .name = "connlimit", @@ -228,6 +275,7 @@ static struct xtables_match connlimit_mt_reg[] = { .print = connlimit_print4, .save = connlimit_save4, .x6_options = connlimit_opts, + .xlate = connlimit_xlate, }, { .name = "connlimit", @@ -243,6 +291,7 @@ static struct xtables_match connlimit_mt_reg[] = { .print = connlimit_print6, .save = connlimit_save6, .x6_options = connlimit_opts, + .xlate = connlimit_xlate, }, }; -- cgit v1.2.3