Add translation for icmp to nftables. Not supported types in nftables
are: any, network-unreachable, host-unreachable, protocol-unreachable,
port-unreachable, fragmentation-needed, source-route-failed,
network-unknown, host-unknown, network-prohibited, host-prohibited,
TOS-network-unreachable, TOS-host-unreachable, communication-prohibited,
host-precedence-violation, precedence-cutoff, network-redirect,
host-redirect, TOS-network-redirect, TOS-host-redirect,
router-advertisement, router-solicitation, ttl-zero-during-transit,
ttl-zero-during-reassembly, ip-header-bad and required-option-missing.
Examples:
$ sudo iptables-translate -t filter -A INPUT -m icmp --icmp-type echo-reply -j LOG
nft add rule ip filter INPUT icmp type echo-reply counter log level warn
$ sudo iptables-translate -t filter -A INPUT -m icmp --icmp-type 3 -j LOG
nft add rule ip filter INPUT icmp type destination-unreachable counter log level warn
$ sudo iptables-translate -t filter -A INPUT -m icmp ! --icmp-type 3 -j LOG
nft add rule ip filter INPUT icmp type != destination-unreachable counter log level warn
Signed-off-by: Laura Garcia Liebana <nevola@xxxxxxxxx>
---
v2:
- Detection of not supported types in nftables, as Shivani suggested.
v3:
- Fix array iteration protection.
extensions/libipt_icmp.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 48 insertions(+), 1 deletion(-)
diff --git a/extensions/libipt_icmp.c b/extensions/libipt_icmp.c
index 666e7da..2c8be87 100644
--- a/extensions/libipt_icmp.c
+++ b/extensions/libipt_icmp.c
@@ -218,7 +218,7 @@ static void print_icmptype(uint8_t type,
}
static void icmp_print(const void *ip, const struct xt_entry_match *match,
- int numeric)
+ int numeric)
{
const struct ipt_icmp *icmp = (struct ipt_icmp *)match->data;
@@ -249,6 +249,52 @@ static void icmp_save(const void *ip, const struct xt_entry_match *match)
}
}
+static unsigned int type_xlate_print(struct xt_xlate *xl, unsigned int icmptype,
+ unsigned int code_min, unsigned int code_max)
+{
+ unsigned int i;
+
+ if (code_min == code_max)
+ return 0;
+
+ switch (icmptype) {
+ case 0xFF:
+ case 9:
+ case 10:
+ return 0;
+ default:
+ for (i = 0; i < ARRAY_SIZE(icmp_codes); ++i)
+ if (icmp_codes[i].type == icmptype &&
+ icmp_codes[i].code_min == code_min &&
+ icmp_codes[i].code_max == code_max)
+ break;
+
+ if (i != ARRAY_SIZE(icmp_codes))
+ xt_xlate_add(xl, icmp_codes[i].name);
+ else
+ return 0;
+ }
+
+ return 1;
+}
+
+static int icmp_xlate(const struct xt_entry_match *match, struct xt_xlate *xl,
+ int numeric)
+{
+ const struct ipt_icmp *info = (struct ipt_icmp *)match->data;
+
+ xt_xlate_add(xl, "icmp type%s ",
+ (info->invflags & IPT_ICMP_INV) ? " !=" : "");
+
+ if (!type_xlate_print(xl, info->type, info->code[0], info->code[1]))
+ return 0;
+
+ xt_xlate_add(xl, " ");
+
+ return 1;
+}
+
+
static struct xtables_match icmp_mt_reg = {
.name = "icmp",
.version = XTABLES_VERSION,
@@ -261,6 +307,7 @@ static struct xtables_match icmp_mt_reg = {
.save = icmp_save,
.x6_parse = icmp_parse,
.x6_options = icmp_opts,
+ .xlate = icmp_xlate,
};
void _init(void)
--
2.7.0
--
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