&udp_port_rover);
 }
 
-static bool
-udp_manip_pkt(struct sk_buff *skb,
-             const struct nf_nat_l3proto *l3proto,
-             unsigned int iphdroff, unsigned int hdroff,
-             const struct nf_conntrack_tuple *tuple,
-             enum nf_nat_manip_type maniptype)
+static void
+__udp_manip_pkt(struct sk_buff *skb,
+               const struct nf_nat_l3proto *l3proto,
+               unsigned int iphdroff, struct udphdr *hdr,
+               const struct nf_conntrack_tuple *tuple,
+               enum nf_nat_manip_type maniptype, bool do_csum)
 {
-       struct udphdr *hdr;
        __be16 *portptr, newport;
 
-       if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
-               return false;
-       hdr = (struct udphdr *)(skb->data + hdroff);
-
        if (maniptype == NF_NAT_MANIP_SRC) {
                /* Get rid of src port */
                newport = tuple->src.u.udp.port;
                newport = tuple->dst.u.udp.port;
                portptr = &hdr->dest;
        }
-       if (hdr->check || skb->ip_summed == CHECKSUM_PARTIAL) {
+       if (do_csum) {
                l3proto->csum_update(skb, iphdroff, &hdr->check,
                                     tuple, maniptype);
                inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport,
                        hdr->check = CSUM_MANGLED_0;
        }
        *portptr = newport;
+}
+
+static bool udp_manip_pkt(struct sk_buff *skb,
+                         const struct nf_nat_l3proto *l3proto,
+                         unsigned int iphdroff, unsigned int hdroff,
+                         const struct nf_conntrack_tuple *tuple,
+                         enum nf_nat_manip_type maniptype)
+{
+       struct udphdr *hdr;
+       bool do_csum;
+
+       if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+               return false;
+
+       hdr = (struct udphdr *)(skb->data + hdroff);
+       do_csum = hdr->check || skb->ip_summed == CHECKSUM_PARTIAL;
+
+       __udp_manip_pkt(skb, l3proto, iphdroff, hdr, tuple, maniptype, do_csum);
+       return true;
+}
+
+#ifdef CONFIG_NF_NAT_PROTO_UDPLITE
+static u16 udplite_port_rover;
+
+static bool udplite_manip_pkt(struct sk_buff *skb,
+                             const struct nf_nat_l3proto *l3proto,
+                             unsigned int iphdroff, unsigned int hdroff,
+                             const struct nf_conntrack_tuple *tuple,
+                             enum nf_nat_manip_type maniptype)
+{
+       struct udphdr *hdr;
+
+       if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+               return false;
+
+       hdr = (struct udphdr *)(skb->data + hdroff);
+       __udp_manip_pkt(skb, l3proto, iphdroff, hdr, tuple, maniptype, true);
        return true;
 }
 
+static void
+udplite_unique_tuple(const struct nf_nat_l3proto *l3proto,
+                    struct nf_conntrack_tuple *tuple,
+                    const struct nf_nat_range *range,
+                    enum nf_nat_manip_type maniptype,
+                    const struct nf_conn *ct)
+{
+       nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct,
+                                   &udplite_port_rover);
+}
+
+const struct nf_nat_l4proto nf_nat_l4proto_udplite = {
+       .l4proto                = IPPROTO_UDPLITE,
+       .manip_pkt              = udplite_manip_pkt,
+       .in_range               = nf_nat_l4proto_in_range,
+       .unique_tuple           = udplite_unique_tuple,
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+       .nlattr_to_range        = nf_nat_l4proto_nlattr_to_range,
+#endif
+};
+#endif /* CONFIG_NF_NAT_PROTO_UDPLITE */
+
 const struct nf_nat_l4proto nf_nat_l4proto_udp = {
        .l4proto                = IPPROTO_UDP,
        .manip_pkt              = udp_manip_pkt,
 
+++ /dev/null
-/* (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
- * (C) 2008 Patrick McHardy <kaber@trash.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/types.h>
-#include <linux/udp.h>
-
-#include <linux/netfilter.h>
-#include <net/netfilter/nf_nat.h>
-#include <net/netfilter/nf_nat_l3proto.h>
-#include <net/netfilter/nf_nat_l4proto.h>
-
-static u16 udplite_port_rover;
-
-static void
-udplite_unique_tuple(const struct nf_nat_l3proto *l3proto,
-                    struct nf_conntrack_tuple *tuple,
-                    const struct nf_nat_range *range,
-                    enum nf_nat_manip_type maniptype,
-                    const struct nf_conn *ct)
-{
-       nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct,
-                                   &udplite_port_rover);
-}
-
-static bool
-udplite_manip_pkt(struct sk_buff *skb,
-                 const struct nf_nat_l3proto *l3proto,
-                 unsigned int iphdroff, unsigned int hdroff,
-                 const struct nf_conntrack_tuple *tuple,
-                 enum nf_nat_manip_type maniptype)
-{
-       struct udphdr *hdr;
-       __be16 *portptr, newport;
-
-       if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
-               return false;
-
-       hdr = (struct udphdr *)(skb->data + hdroff);
-
-       if (maniptype == NF_NAT_MANIP_SRC) {
-               /* Get rid of source port */
-               newport = tuple->src.u.udp.port;
-               portptr = &hdr->source;
-       } else {
-               /* Get rid of dst port */
-               newport = tuple->dst.u.udp.port;
-               portptr = &hdr->dest;
-       }
-
-       l3proto->csum_update(skb, iphdroff, &hdr->check, tuple, maniptype);
-       inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, false);
-       if (!hdr->check)
-               hdr->check = CSUM_MANGLED_0;
-
-       *portptr = newport;
-       return true;
-}
-
-const struct nf_nat_l4proto nf_nat_l4proto_udplite = {
-       .l4proto                = IPPROTO_UDPLITE,
-       .manip_pkt              = udplite_manip_pkt,
-       .in_range               = nf_nat_l4proto_in_range,
-       .unique_tuple           = udplite_unique_tuple,
-#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
-       .nlattr_to_range        = nf_nat_l4proto_nlattr_to_range,
-#endif
-};