netfilter: nft_nat: add helper function to set up NAT address and protocol

This patch add nft_nat_setup_addr() and nft_nat_setup_proto() to set up
the NAT mangling.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_nat.c b/net/netfilter/nft_nat.c
index 5c7ff21..7442aa8 100644 (file)
--- a/net/netfilter/nft_nat.c
+++ b/net/netfilter/nft_nat.c
@@ -30,6 +30,36 @@ struct nft_nat {
        u16                     flags;
 };
 
+static void nft_nat_setup_addr(struct nf_nat_range2 *range,
+                              const struct nft_regs *regs,
+                              const struct nft_nat *priv)
+{
+       switch (priv->family) {
+       case AF_INET:
+               range->min_addr.ip = (__force __be32)
+                               regs->data[priv->sreg_addr_min];
+               range->max_addr.ip = (__force __be32)
+                               regs->data[priv->sreg_addr_max];
+               break;
+       case AF_INET6:
+               memcpy(range->min_addr.ip6, &regs->data[priv->sreg_addr_min],
+                      sizeof(range->min_addr.ip6));
+               memcpy(range->max_addr.ip6, &regs->data[priv->sreg_addr_max],
+                      sizeof(range->max_addr.ip6));
+               break;
+       }
+}
+
+static void nft_nat_setup_proto(struct nf_nat_range2 *range,
+                               const struct nft_regs *regs,
+                               const struct nft_nat *priv)
+{
+       range->min_proto.all = (__force __be16)
+               nft_reg_load16(&regs->data[priv->sreg_proto_min]);
+       range->max_proto.all = (__force __be16)
+               nft_reg_load16(&regs->data[priv->sreg_proto_max]);
+}
+
 static void nft_nat_eval(const struct nft_expr *expr,
                         struct nft_regs *regs,
                         const struct nft_pktinfo *pkt)
@@ -40,29 +70,11 @@ static void nft_nat_eval(const struct nft_expr *expr,
        struct nf_nat_range2 range;
 
        memset(&range, 0, sizeof(range));
-       if (priv->sreg_addr_min) {
-               if (priv->family == AF_INET) {
-                       range.min_addr.ip = (__force __be32)
-                                       regs->data[priv->sreg_addr_min];
-                       range.max_addr.ip = (__force __be32)
-                                       regs->data[priv->sreg_addr_max];
-
-               } else {
-                       memcpy(range.min_addr.ip6,
-                              &regs->data[priv->sreg_addr_min],
-                              sizeof(range.min_addr.ip6));
-                       memcpy(range.max_addr.ip6,
-                              &regs->data[priv->sreg_addr_max],
-                              sizeof(range.max_addr.ip6));
-               }
-       }
+       if (priv->sreg_addr_min)
+               nft_nat_setup_addr(&range, regs, priv);
 
-       if (priv->sreg_proto_min) {
-               range.min_proto.all = (__force __be16)nft_reg_load16(
-                       &regs->data[priv->sreg_proto_min]);
-               range.max_proto.all = (__force __be16)nft_reg_load16(
-                       &regs->data[priv->sreg_proto_max]);
-       }
+       if (priv->sreg_proto_min)
+               nft_nat_setup_proto(&range, regs, priv);
 
        range.flags = priv->flags;