nft: check for source and destination address in first place

When generating bytecode, check for source and destination address in
first place, then, check for the input and output device. In general,
the first expression in the rule is the most evaluated during the
evaluation process. These selectors are likely to show more variability
in rulesets.

 # iptables-nft -vv -I INPUT -s 1.2.3.4 -p tcp
  tcp opt -- in * out *  1.2.3.4  -> 0.0.0.0/0
table filter ip flags 0 use 0 handle 0
ip filter INPUT use 0 type filter hook input prio 0 policy accept packets 0 bytes 0
ip filter INPUT
  [ payload load 4b @ network header + 12 => reg 1 ]
  [ cmp eq reg 1 0x04030201 ]
  [ meta load l4proto => reg 1 ]
  [ cmp eq reg 1 0x00000006 ]
  [ counter pkts 0 bytes 0 ]

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Phil Sutter <phil@nwl.cc>

3 files changed, 47 insertions, 43 deletions

diff --git a/iptables/nft-bridge.c b/iptables/nft-bridge.c
index f3dfa488..6e509507 100644
--- a/iptables/nft-bridge.c
+++ b/iptables/nft-bridge.c
@@ -163,6 +163,20 @@ static int nft_bridge_add(struct nft_handle *h,
 	struct ebt_entry *fw = &cs->eb;
 	uint32_t op;
 
+	if (fw->bitmask & EBT_ISOURCE) {
+		op = nft_invflags2cmp(fw->invflags, EBT_ISOURCE);
+		add_addr(h, r, NFT_PAYLOAD_LL_HEADER,
+			 offsetof(struct ethhdr, h_source),
+			 fw->sourcemac, fw->sourcemsk, ETH_ALEN, op);
+	}
+
+	if (fw->bitmask & EBT_IDEST) {
+		op = nft_invflags2cmp(fw->invflags, EBT_IDEST);
+		add_addr(h, r, NFT_PAYLOAD_LL_HEADER,
+			 offsetof(struct ethhdr, h_dest),
+			 fw->destmac, fw->destmsk, ETH_ALEN, op);
+	}
+
 	if (fw->in[0] != '\0') {
 		op = nft_invflags2cmp(fw->invflags, EBT_IIN);
 		add_iniface(h, r, fw->in, op);
@@ -183,20 +197,6 @@ static int nft_bridge_add(struct nft_handle *h,
 		add_logical_outiface(h, r, fw->logical_out, op);
 	}
 
-	if (fw->bitmask & EBT_ISOURCE) {
-		op = nft_invflags2cmp(fw->invflags, EBT_ISOURCE);
-		add_addr(h, r, NFT_PAYLOAD_LL_HEADER,
-			 offsetof(struct ethhdr, h_source),
-			 fw->sourcemac, fw->sourcemsk, ETH_ALEN, op);
-	}
-
-	if (fw->bitmask & EBT_IDEST) {
-		op = nft_invflags2cmp(fw->invflags, EBT_IDEST);
-		add_addr(h, r, NFT_PAYLOAD_LL_HEADER,
-			 offsetof(struct ethhdr, h_dest),
-			 fw->destmac, fw->destmsk, ETH_ALEN, op);
-	}
-
 	if ((fw->bitmask & EBT_NOPROTO) == 0) {
 		uint16_t ethproto = fw->ethproto;
 		uint8_t reg;
diff --git a/iptables/nft-ipv4.c b/iptables/nft-ipv4.c
index 6df4e46b..d67d8198 100644
--- a/iptables/nft-ipv4.c
+++ b/iptables/nft-ipv4.c
@@ -33,6 +33,22 @@ static int nft_ipv4_add(struct nft_handle *h, struct nftnl_rule *r,
 	uint32_t op;
 	int ret;
 
+	if (cs->fw.ip.src.s_addr || cs->fw.ip.smsk.s_addr || cs->fw.ip.invflags & IPT_INV_SRCIP) {
+		op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_SRCIP);
+		add_addr(h, r, NFT_PAYLOAD_NETWORK_HEADER,
+			 offsetof(struct iphdr, saddr),
+			 &cs->fw.ip.src.s_addr, &cs->fw.ip.smsk.s_addr,
+			 sizeof(struct in_addr), op);
+	}
+
+	if (cs->fw.ip.dst.s_addr || cs->fw.ip.dmsk.s_addr || cs->fw.ip.invflags & IPT_INV_DSTIP) {
+		op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_DSTIP);
+		add_addr(h, r, NFT_PAYLOAD_NETWORK_HEADER,
+			 offsetof(struct iphdr, daddr),
+			 &cs->fw.ip.dst.s_addr, &cs->fw.ip.dmsk.s_addr,
+			 sizeof(struct in_addr), op);
+	}
+
 	if (cs->fw.ip.iniface[0] != '\0') {
 		op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_VIA_IN);
 		add_iniface(h, r, cs->fw.ip.iniface, op);
@@ -48,20 +64,6 @@ static int nft_ipv4_add(struct nft_handle *h, struct nftnl_rule *r,
 		add_l4proto(h, r, cs->fw.ip.proto, op);
 	}
 
-	if (cs->fw.ip.src.s_addr || cs->fw.ip.smsk.s_addr || cs->fw.ip.invflags & IPT_INV_SRCIP) {
-		op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_SRCIP);
-		add_addr(h, r, NFT_PAYLOAD_NETWORK_HEADER,
-			 offsetof(struct iphdr, saddr),
-			 &cs->fw.ip.src.s_addr, &cs->fw.ip.smsk.s_addr,
-			 sizeof(struct in_addr), op);
-	}
-	if (cs->fw.ip.dst.s_addr || cs->fw.ip.dmsk.s_addr || cs->fw.ip.invflags & IPT_INV_DSTIP) {
-		op = nft_invflags2cmp(cs->fw.ip.invflags, IPT_INV_DSTIP);
-		add_addr(h, r, NFT_PAYLOAD_NETWORK_HEADER,
-			 offsetof(struct iphdr, daddr),
-			 &cs->fw.ip.dst.s_addr, &cs->fw.ip.dmsk.s_addr,
-			 sizeof(struct in_addr), op);
-	}
 	if (cs->fw.ip.flags & IPT_F_FRAG) {
 		uint8_t reg;
 
diff --git a/iptables/nft-ipv6.c b/iptables/nft-ipv6.c
index 693a1c87..658a4f20 100644
--- a/iptables/nft-ipv6.c
+++ b/iptables/nft-ipv6.c
@@ -32,21 +32,6 @@ static int nft_ipv6_add(struct nft_handle *h, struct nftnl_rule *r,
 	uint32_t op;
 	int ret;
 
-	if (cs->fw6.ipv6.iniface[0] != '\0') {
-		op = nft_invflags2cmp(cs->fw6.ipv6.invflags, IPT_INV_VIA_IN);
-		add_iniface(h, r, cs->fw6.ipv6.iniface, op);
-	}
-
-	if (cs->fw6.ipv6.outiface[0] != '\0') {
-		op = nft_invflags2cmp(cs->fw6.ipv6.invflags, IPT_INV_VIA_OUT);
-		add_outiface(h, r, cs->fw6.ipv6.outiface, op);
-	}
-
-	if (cs->fw6.ipv6.proto != 0) {
-		op = nft_invflags2cmp(cs->fw6.ipv6.invflags, XT_INV_PROTO);
-		add_l4proto(h, r, cs->fw6.ipv6.proto, op);
-	}
-
 	if (!IN6_IS_ADDR_UNSPECIFIED(&cs->fw6.ipv6.src) ||
 	    !IN6_IS_ADDR_UNSPECIFIED(&cs->fw6.ipv6.smsk) ||
 	    (cs->fw6.ipv6.invflags & IPT_INV_SRCIP)) {
@@ -56,6 +41,7 @@ static int nft_ipv6_add(struct nft_handle *h, struct nftnl_rule *r,
 			 &cs->fw6.ipv6.src, &cs->fw6.ipv6.smsk,
 			 sizeof(struct in6_addr), op);
 	}
+
 	if (!IN6_IS_ADDR_UNSPECIFIED(&cs->fw6.ipv6.dst) ||
 	    !IN6_IS_ADDR_UNSPECIFIED(&cs->fw6.ipv6.dmsk) ||
 	    (cs->fw6.ipv6.invflags & IPT_INV_DSTIP)) {
@@ -65,6 +51,22 @@ static int nft_ipv6_add(struct nft_handle *h, struct nftnl_rule *r,
 			 &cs->fw6.ipv6.dst, &cs->fw6.ipv6.dmsk,
 			 sizeof(struct in6_addr), op);
 	}
+
+	if (cs->fw6.ipv6.iniface[0] != '\0') {
+		op = nft_invflags2cmp(cs->fw6.ipv6.invflags, IPT_INV_VIA_IN);
+		add_iniface(h, r, cs->fw6.ipv6.iniface, op);
+	}
+
+	if (cs->fw6.ipv6.outiface[0] != '\0') {
+		op = nft_invflags2cmp(cs->fw6.ipv6.invflags, IPT_INV_VIA_OUT);
+		add_outiface(h, r, cs->fw6.ipv6.outiface, op);
+	}
+
+	if (cs->fw6.ipv6.proto != 0) {
+		op = nft_invflags2cmp(cs->fw6.ipv6.invflags, XT_INV_PROTO);
+		add_l4proto(h, r, cs->fw6.ipv6.proto, op);
+	}
+
 	add_compat(r, cs->fw6.ipv6.proto, cs->fw6.ipv6.invflags & XT_INV_PROTO);
 
 	for (matchp = cs->matches; matchp; matchp = matchp->next) {