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Diffstat (limited to 'fwd.c')
-rw-r--r--fwd.c27
1 files changed, 23 insertions, 4 deletions
diff --git a/fwd.c b/fwd.c
index 3288b0d..a70ebfd 100644
--- a/fwd.c
+++ b/fwd.c
@@ -169,12 +169,16 @@ void fwd_scan_ports_init(struct ctx *c)
uint8_t fwd_nat_from_tap(const struct ctx *c, uint8_t proto,
const struct flowside *ini, struct flowside *tgt)
{
- (void)proto;
-
tgt->eaddr = ini->faddr;
tgt->eport = ini->fport;
- if (!c->no_map_gw) {
+ if (proto == IPPROTO_UDP && tgt->eport == 53 &&
+ inany_equals4(&tgt->eaddr, &c->ip4.dns_match)) {
+ tgt->eaddr = inany_from_v4(c->ip4.dns_host);
+ } else if (proto == IPPROTO_UDP && tgt->eport == 53 &&
+ inany_equals6(&tgt->eaddr, &c->ip6.dns_match)) {
+ tgt->eaddr.a6 = c->ip6.dns_host;
+ } else if (!c->no_map_gw) {
if (inany_equals4(&tgt->eaddr, &c->ip4.gw))
tgt->eaddr = inany_loopback4;
else if (inany_equals6(&tgt->eaddr, &c->ip6.gw))
@@ -191,6 +195,10 @@ uint8_t fwd_nat_from_tap(const struct ctx *c, uint8_t proto,
/* Let the kernel pick a host side source port */
tgt->fport = 0;
+ if (proto == IPPROTO_UDP) {
+ /* But for UDP we preserve the source port */
+ tgt->fport = ini->eport;
+ }
return PIF_HOST;
}
@@ -233,9 +241,14 @@ uint8_t fwd_nat_from_splice(const struct ctx *c, uint8_t proto,
tgt->eport = ini->fport;
if (proto == IPPROTO_TCP)
tgt->eport += c->tcp.fwd_out.delta[tgt->eport];
+ else if (proto == IPPROTO_UDP)
+ tgt->eport += c->udp.fwd_out.f.delta[tgt->eport];
/* Let the kernel pick a host side source port */
tgt->fport = 0;
+ if (proto == IPPROTO_UDP)
+ /* But for UDP preserve the source port */
+ tgt->fport = ini->eport;
return PIF_HOST;
}
@@ -257,9 +270,11 @@ uint8_t fwd_nat_from_host(const struct ctx *c, uint8_t proto,
tgt->eport = ini->fport;
if (proto == IPPROTO_TCP)
tgt->eport += c->tcp.fwd_in.delta[tgt->eport];
+ else if (proto == IPPROTO_UDP)
+ tgt->eport += c->udp.fwd_in.f.delta[tgt->eport];
if (c->mode == MODE_PASTA && inany_is_loopback(&ini->eaddr) &&
- proto == IPPROTO_TCP) {
+ (proto == IPPROTO_TCP || proto == IPPROTO_UDP)) {
/* spliceable */
/* Preserve the specific loopback adddress used, but let the
@@ -267,11 +282,15 @@ uint8_t fwd_nat_from_host(const struct ctx *c, uint8_t proto,
*/
tgt->faddr = ini->eaddr;
tgt->fport = 0;
+ if (proto == IPPROTO_UDP)
+ /* But for UDP preserve the source port */
+ tgt->fport = ini->eport;
if (inany_v4(&ini->eaddr))
tgt->eaddr = inany_loopback4;
else
tgt->eaddr = inany_loopback6;
+
return PIF_SPLICE;
}