extensions: ipt_DNAT: Combine xlate functions also

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>

diff --git a/extensions/libipt_DNAT.c b/extensions/libipt_DNAT.c
index b72437d5e92f28f8e246ed8a1d753ccd9fa5baf3..9a179919f522da7de46659409980b95d9936f17e 100644 (file)
--- 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[] = {