From: Matt Corallo <git@bluematt.me>
Date: Tue, 25 May 2021 03:06:53 +0000 (+0000)
Subject: Drop ports_valid flag, it just wastes a register
X-Git-Url: http://git.bitcoin.ninja/?a=commitdiff_plain;h=ac33c8518d541b228fc24efcb89858abca0fc75f;p=flowspec-xdp

Drop ports_valid flag, it just wastes a register
---

diff --git a/genrules.py b/genrules.py
index 37c533e..5d90e8c 100755
--- a/genrules.py
+++ b/genrules.py
@@ -239,10 +239,10 @@ def dscp_to_rule(proto, rules):
 def port_to_rule(ty, rules):
     if ty == "port" :
         ast = parse_ast(rules, parse_numbers_expr, True)
-        return "if (!ports_valid) break;\nif (!( " + ast.write("sport", "dport") + " )) break;"
+        return "if (sport == -1 || dport == -1) break;\nif (!( " + ast.write("sport", "dport") + " )) break;"
 
     ast = parse_ast(rules, parse_numbers_expr, True)
-    return "if (!ports_valid) break;\nif (!( " + ast.write(ty) + " )) break;"
+    return "if (" + ty + " == -1) break;\nif (!( " + ast.write(ty) + " )) break;"
 
 def tcp_flags_to_rule(rules):
     ast = parse_ast(rules, parse_bit_expr, False)
diff --git a/xdp.c b/xdp.c
index a32f605..75a44ff 100644
--- a/xdp.c
+++ b/xdp.c
@@ -264,8 +264,7 @@ int xdp_drop_prog(struct xdp_md *ctx)
 
 	const void *l4hdr = NULL;
 	const struct tcphdr *tcp = NULL;
-	uint8_t ports_valid = 0;
-	uint16_t sport = 0, dport = 0; // Host Endian! Only valid with tcp || udp
+	int32_t sport = -1, dport = -1; // Host Endian! Only valid with tcp || udp
 
 #ifdef NEED_V4_PARSE
 	if (eth_proto == BE16(ETH_P_IP)) {
@@ -287,13 +286,11 @@ int xdp_drop_prog(struct xdp_md *ctx)
 				tcp = (struct tcphdr*) l4hdr;
 				sport = BE16(tcp->source);
 				dport = BE16(tcp->dest);
-				ports_valid = 1;
 			} else if (ip->protocol == IP_PROTO_UDP) {
 				CHECK_LEN(l4hdr, udphdr);
 				const struct udphdr *udp = (struct udphdr*) l4hdr;
 				sport = BE16(udp->source);
 				dport = BE16(udp->dest);
-				ports_valid = 1;
 			} else if (ip->protocol == IP_PROTO_ICMP) {
 				CHECK_LEN(l4hdr, icmphdr);
 				icmp = (struct icmphdr*) l4hdr;
@@ -334,13 +331,11 @@ int xdp_drop_prog(struct xdp_md *ctx)
 				tcp = (struct tcphdr*) l4hdr;
 				sport = BE16(tcp->source);
 				dport = BE16(tcp->dest);
-				ports_valid = 1;
 			} else if (v6nexthdr == IP_PROTO_UDP) {
 				CHECK_LEN(l4hdr, udphdr);
 				const struct udphdr *udp = (struct udphdr*) l4hdr;
 				sport = BE16(udp->source);
 				dport = BE16(udp->dest);
-				ports_valid = 1;
 			} else if (v6nexthdr == IP6_PROTO_ICMPV6) {
 				CHECK_LEN(l4hdr, icmp6hdr);
 				icmpv6 = (struct icmp6hdr*) l4hdr;