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From: Phil Sutter <phil@nwl.cc>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org
Subject: [iptables PATCH 5/9] extensions: ipt_DNAT: Combine xlate functions also
Date: Wed, 30 Mar 2022 17:58:47 +0200	[thread overview]
Message-ID: <20220330155851.13249-6-phil@nwl.cc> (raw)
In-Reply-To: <20220330155851.13249-1-phil@nwl.cc>

Make use of the new sprint_range() to introduce a common inner function
for both v1 and v2 xlate functions.

Also abort translation with shifted port ranges to not hide the missing
feature in nftables.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 extensions/libipt_DNAT.c | 88 ++++++++++------------------------------
 1 file changed, 21 insertions(+), 67 deletions(-)

diff --git a/extensions/libipt_DNAT.c b/extensions/libipt_DNAT.c
index b72437d5e92f2..9a179919f522d 100644
--- a/extensions/libipt_DNAT.c
+++ b/extensions/libipt_DNAT.c
@@ -266,47 +266,36 @@ static void DNAT_save(const void *ip, const struct xt_entry_target *target)
 	__DNAT_print(&range, true);
 }
 
-static void print_range_xlate(const struct nf_nat_ipv4_range *r,
-			struct xt_xlate *xl)
+static int __DNAT_xlate(struct xt_xlate *xl, const struct nf_nat_range2 *r)
 {
-	if (r->flags & NF_NAT_RANGE_MAP_IPS) {
-		struct in_addr a;
+	char *range_str = sprint_range(r);
+	const char *sep = " ";
 
-		a.s_addr = r->min_ip;
-		xt_xlate_add(xl, "%s", xtables_ipaddr_to_numeric(&a));
-		if (r->max_ip != r->min_ip) {
-			a.s_addr = r->max_ip;
-			xt_xlate_add(xl, "-%s", xtables_ipaddr_to_numeric(&a));
-		}
+	/* shifted portmap ranges are not supported by nftables */
+	if (r->flags & NF_NAT_RANGE_PROTO_OFFSET)
+		return 0;
+
+	xt_xlate_add(xl, "dnat");
+	if (strlen(range_str))
+		xt_xlate_add(xl, " to %s", range_str);
+	if (r->flags & NF_NAT_RANGE_PROTO_RANDOM) {
+		xt_xlate_add(xl, "%srandom", sep);
+		sep = ",";
 	}
-	if (r->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
-		xt_xlate_add(xl, ":%hu", ntohs(r->min.tcp.port));
-		if (r->max.tcp.port != r->min.tcp.port)
-			xt_xlate_add(xl, "-%hu", ntohs(r->max.tcp.port));
+	if (r->flags & NF_NAT_RANGE_PERSISTENT) {
+		xt_xlate_add(xl, "%spersistent", sep);
+		sep = ",";
 	}
+	return 1;
 }
 
 static int DNAT_xlate(struct xt_xlate *xl,
 		      const struct xt_xlate_tg_params *params)
 {
-	const struct nf_nat_ipv4_multi_range_compat *mr =
-			(const void *)params->target->data;
-	bool sep_need = false;
-	const char *sep = " ";
-
-	xt_xlate_add(xl, "dnat to ");
-	print_range_xlate(mr->range, xl);
-	if (mr->range->flags & NF_NAT_RANGE_PROTO_RANDOM) {
-		xt_xlate_add(xl, " random");
-		sep_need = true;
-	}
-	if (mr->range->flags & NF_NAT_RANGE_PERSISTENT) {
-		if (sep_need)
-			sep = ",";
-		xt_xlate_add(xl, "%spersistent", sep);
-	}
+	struct nf_nat_range2 range =
+		RANGE2_INIT_FROM_IPV4_MRC(params->target->data);
 
-	return 1;
+	return __DNAT_xlate(xl, &range);
 }
 
 static void DNAT_parse_v2(struct xt_option_call *cb)
@@ -336,45 +325,10 @@ static void DNAT_save_v2(const void *ip, const struct xt_entry_target *target)
 	__DNAT_print((const void *)target->data, true);
 }
 
-static void print_range_xlate_v2(const struct nf_nat_range2 *range,
-			      struct xt_xlate *xl)
-{
-	if (range->flags & NF_NAT_RANGE_MAP_IPS) {
-		xt_xlate_add(xl, "%s", xtables_ipaddr_to_numeric(&range->min_addr.in));
-		if (memcmp(&range->min_addr, &range->max_addr,
-			   sizeof(range->min_addr))) {
-			xt_xlate_add(xl, "-%s", xtables_ipaddr_to_numeric(&range->max_addr.in));
-		}
-	}
-	if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
-		xt_xlate_add(xl, ":%hu", ntohs(range->min_proto.tcp.port));
-		if (range->max_proto.tcp.port != range->min_proto.tcp.port)
-			xt_xlate_add(xl, "-%hu", ntohs(range->max_proto.tcp.port));
-		if (range->flags & NF_NAT_RANGE_PROTO_OFFSET)
-			xt_xlate_add(xl, ";%hu", ntohs(range->base_proto.tcp.port));
-	}
-}
-
 static int DNAT_xlate_v2(struct xt_xlate *xl,
 		      const struct xt_xlate_tg_params *params)
 {
-	const struct nf_nat_range2 *range = (const void *)params->target->data;
-	bool sep_need = false;
-	const char *sep = " ";
-
-	xt_xlate_add(xl, "dnat to ");
-	print_range_xlate_v2(range, xl);
-	if (range->flags & NF_NAT_RANGE_PROTO_RANDOM) {
-		xt_xlate_add(xl, " random");
-		sep_need = true;
-	}
-	if (range->flags & NF_NAT_RANGE_PERSISTENT) {
-		if (sep_need)
-			sep = ",";
-		xt_xlate_add(xl, "%spersistent", sep);
-	}
-
-	return 1;
+	return __DNAT_xlate(xl, (const void *)params->target->data);
 }
 
 static struct xtables_target dnat_tg_reg[] = {
-- 
2.34.1


  parent reply	other threads:[~2022-03-30 15:59 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-30 15:58 [iptables PATCH 0/9] extensions: Merge *_DNAT and *_REDIRECT Phil Sutter
2022-03-30 15:58 ` [iptables PATCH 1/9] man: DNAT: Describe shifted port range feature Phil Sutter
2022-03-30 15:58 ` [iptables PATCH 2/9] Revert "libipt_[SD]NAT: avoid false error about multiple destinations specified" Phil Sutter
2022-03-30 15:58 ` [iptables PATCH 3/9] extensions: ipt_DNAT: Merge v1 and v2 parsers Phil Sutter
2022-03-30 15:58 ` [iptables PATCH 4/9] extensions: ipt_DNAT: Merge v1/v2 print/save code Phil Sutter
2022-03-30 15:58 ` Phil Sutter [this message]
2022-03-30 15:58 ` [iptables PATCH 6/9] extensions: DNAT: Rename from libipt to libxt Phil Sutter
2022-03-30 15:58 ` [iptables PATCH 7/9] extensions: Merge IPv4 and IPv6 DNAT targets Phil Sutter
2022-03-30 15:58 ` [iptables PATCH 8/9] extensions: Merge REDIRECT into DNAT Phil Sutter
2022-03-30 15:58 ` [iptables PATCH 9/9] extensions: DNAT: Support service names in all spots Phil Sutter
2022-03-30 18:38   ` Jan Engelhardt
2022-03-30 20:57     ` Phil Sutter
2022-03-31  0:19       ` Jan Engelhardt
2022-03-31 10:04         ` Phil Sutter

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