Add translation for dccp to nftables.
Full translation of this match awaits the support for --dccp-option.
Examples:
$ sudo iptables-translate -A INPUT -p dccp -m dccp --sport 100
nft add rule ip filter INPUT dccp sport 100 counter
$ sudo iptables-translate -A INPUT -p dccp -m dccp --dport 100:200
nft add rule ip filter INPUT dccp dport 100-200 counter
$ sudo iptables-translate -A INPUT -p dccp -m dccp ! --dport 100
nft add rule ip filter INPUT dccp dport != 100 counter
$ sudo iptables-translate -A INPUT -p dccp -m dccp --dport 100 --dccp-types REQUEST,RESPONSE,DATA,ACK,DATAACK,CLOSEREQ,CLOSE,SYNC,SYNCACK
nft add rule ip filter INPUT dccp dport 100 dccp type {request, response, data, ack, dataack, closereq, close, sync, syncack} counter
Signed-off-by: Shivani Bhardwaj <shivanib134@xxxxxxxxx>
---
Changes in v3:
Return 0 if translation for dccp-option is demanded
Changes in v2:
Fix bugs and remove invalid dccp type
Following is not added in commit message as it is not translation code
issue:
* Since inversion of set is not possible in nftables, using dccp
with rules like
...dccp type != {request, response}..
* dccp type reset
is going to throw errors.
extensions/libxt_dccp.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)
diff --git a/extensions/libxt_dccp.c b/extensions/libxt_dccp.c
index a35cabb..0d4f369 100644
--- a/extensions/libxt_dccp.c
+++ b/extensions/libxt_dccp.c
@@ -277,6 +277,97 @@ static void dccp_save(const void *ip, const struct xt_entry_match *match)
}
}
+static const char *const dccp_pkt_types_xlate[] = {
+ [DCCP_PKT_REQUEST] = "request",
+ [DCCP_PKT_RESPONSE] = "response",
+ [DCCP_PKT_DATA] = "data",
+ [DCCP_PKT_ACK] = "ack",
+ [DCCP_PKT_DATAACK] = "dataack",
+ [DCCP_PKT_CLOSEREQ] = "closereq",
+ [DCCP_PKT_CLOSE] = "close",
+ [DCCP_PKT_RESET] = "reset",
+ [DCCP_PKT_SYNC] = "sync",
+ [DCCP_PKT_SYNCACK] = "syncack",
+};
+
+static int dccp_type_xlate(const struct xt_dccp_info *einfo,
+ struct xt_xlate *xl)
+{
+ bool have_type = false, set_need = false;
+ uint16_t types = einfo->typemask;
+
+ if (types & (1 << DCCP_PKT_INVALID))
+ return 0;
+
+ xt_xlate_add(xl, "dccp type%s ", einfo->invflags ? " !=" : "");
+
+ if ((types != 0) && !(types == (types & -types))) {
+ xt_xlate_add(xl, "{");
+ set_need = true;
+ }
+
+ while (types) {
+ unsigned int i;
+
+ for (i = 0; !(types & (1 << i)); i++);
+
+ if (have_type)
+ xt_xlate_add(xl, ", ");
+ else
+ have_type = true;
+
+ xt_xlate_add(xl, "%s", dccp_pkt_types_xlate[i]);
+
+ types &= ~(1 << i);
+ }
+
+ if (set_need)
+ xt_xlate_add(xl, "}");
+
+ xt_xlate_add(xl, " ");
+
+ return 1;
+}
+
+static int dccp_xlate(const struct xt_entry_match *match,
+ struct xt_xlate *xl, int numeric)
+{
+ const struct xt_dccp_info *einfo =
+ (const struct xt_dccp_info *)match->data;
+ int ret = 1;
+
+ xt_xlate_add(xl, "dccp ");
+
+ if (einfo->flags & XT_DCCP_SRC_PORTS) {
+ if (einfo->spts[0] != einfo->spts[1])
+ xt_xlate_add(xl, "sport%s %u-%u ",
+ einfo->invflags & XT_DCCP_SRC_PORTS ? " !=" : "",
+ einfo->spts[0], einfo->spts[1]);
+ else
+ xt_xlate_add(xl, "sport%s %u ",
+ einfo->invflags & XT_DCCP_SRC_PORTS ? " !=" : "",
+ einfo->spts[0]);
+ }
+
+ if (einfo->flags & XT_DCCP_DEST_PORTS) {
+ if (einfo->dpts[0] != einfo->dpts[1])
+ xt_xlate_add(xl, "dport%s %u-%u ",
+ einfo->invflags & XT_DCCP_DEST_PORTS ? " !=" : "",
+ einfo->dpts[0], einfo->dpts[1]);
+ else
+ xt_xlate_add(xl, "dport%s %u ",
+ einfo->invflags & XT_DCCP_DEST_PORTS ? " !=" : "",
+ einfo->dpts[0]);
+ }
+
+ if (einfo->flags & XT_DCCP_TYPE)
+ ret = dccp_type_xlate(einfo, xl);
+
+ if (einfo->flags & XT_DCCP_OPTION)
+ ret = 0;
+
+ return ret;
+}
static struct xtables_match dccp_match = {
.name = "dccp",
.family = NFPROTO_UNSPEC,
@@ -288,6 +379,7 @@ static struct xtables_match dccp_match = {
.save = dccp_save,
.x6_parse = dccp_parse,
.x6_options = dccp_opts,
+ .xlate = dccp_xlate,
};
void _init(void)
--
1.9.1
--
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