Only parse v4/v6 if we have relevant rules for them

[flowspec-xdp] / xdp.c

diff --git a/xdp.c b/xdp.c
index 669d3ebfa365f13feee331258df4b4434e3cc5ab..b93b16936bdfdde7f72d6e84277a95cda8e501cf 100644 (file)
--- a/xdp.c
+++ b/xdp.c
@@ -170,14 +170,21 @@ int xdp_drop_prog(struct xdp_md *ctx)
                }
        }
 
-       const struct tcphdr *tcp = NULL;
-       const struct udphdr *udp = NULL;
+#ifdef NEED_V4_PARSE
+       const struct iphdr *ip = NULL;
        const struct icmphdr *icmp = NULL;
+#endif
+#ifdef NEED_V6_PARSE
+       const struct ip6hdr *ip6 = NULL;
        const struct icmp6hdr *icmpv6 = NULL;
        const struct ip6_fraghdr *frag6 = NULL;
-       const struct iphdr *ip = NULL;
-       const struct ip6hdr *ip6 = NULL;
+#endif
+
        const void *l4hdr = NULL;
+       const struct tcphdr *tcp = NULL;
+       const struct udphdr *udp = NULL;
+
+#ifdef NEED_V4_PARSE
        if (eth_proto == BE16(ETH_P_IP)) {
                if (unlikely(pktdata + sizeof(struct iphdr) > data_end))
                        return XDP_DROP;
@@ -204,7 +211,10 @@ int xdp_drop_prog(struct xdp_md *ctx)
                                return XDP_DROP;
                        icmp = (struct icmphdr*) l4hdr;
                }
-       } else if (eth_proto == BE16(ETH_P_IPV6)) {
+       }
+#endif
+#ifdef NEED_V6_PARSE
+       if (eth_proto == BE16(ETH_P_IPV6)) {
                if (unlikely(pktdata + sizeof(struct ip6hdr) > data_end))
                        return XDP_DROP;
                ip6 = (struct ip6hdr*) pktdata;
@@ -236,9 +246,8 @@ int xdp_drop_prog(struct xdp_md *ctx)
                        icmpv6 = (struct icmp6hdr*) l4hdr;
                }
                // TODO: Handle some options?
-       } else {
-               return XDP_PASS;
        }
+#endif
 
        uint16_t sport, dport; // Host Endian! Only valid with tcp || udp
        if (tcp != NULL) {