X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=xdp.c;h=b93b16936bdfdde7f72d6e84277a95cda8e501cf;hb=b6de860db504248c8eb737887e10a334a2b5c298;hp=26a12313097539af3477af65dece5d8945016d98;hpb=e6d17f2612e4274d79de87b5d6c0cb992c1aa888;p=flowspec-xdp

diff --git a/xdp.c b/xdp.c
index 26a1231..b93b169 100644
--- a/xdp.c
+++ b/xdp.c
@@ -104,8 +104,8 @@ struct tcphdr {
 #define MASK6(pfxlen) HTON128(~((((uint128_t)1) << (128 - pfxlen)) - 1))
 #define MASK6_OFFS(offs, pfxlen) HTON128((~((((uint128_t)1) << (128 - pfxlen)) - 1)) & ((((uint128_t)1) << (128 - offs)) - 1))
 
-// Note rules.h may also define PARSE_8021Q and REQ_8021Q
-// Note rules.h may also define PARSE_IHL
+// PARSE is used as a preprocessor flag to indicate parsing fields
+#define PARSE 42
 #include "rules.h"
 
 #define unlikely(a) __builtin_expect(a, 0)
@@ -143,7 +143,7 @@ int xdp_drop_prog(struct xdp_md *ctx)
 			return XDP_DROP;
 		const struct ethhdr *const eth = (void*)(size_t)ctx->data;
 
-#ifdef PARSE_8021Q
+#if PARSE_8021Q == PARSE
 		if (likely(eth->h_proto == BE16(ETH_P_8021Q))) {
 			if (unlikely((void*)(size_t)ctx->data + sizeof(struct ethhdr_vlan) > data_end))
 				return XDP_DROP;
@@ -156,6 +156,10 @@ int xdp_drop_prog(struct xdp_md *ctx)
 
 			eth_proto = eth_vlan->h_proto;
 			pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr_vlan);
+#else
+		if (unlikely(eth->h_proto == BE16(ETH_P_8021Q))) {
+			return PARSE_8021Q;
+#endif
 		} else {
 #ifdef REQ_8021Q
 			return XDP_DROP;
@@ -164,32 +168,36 @@ int xdp_drop_prog(struct xdp_md *ctx)
 			eth_proto = eth->h_proto;
 #endif
 		}
-#else
-		pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr);
-		eth_proto = eth->h_proto;
-#endif
 	}
 
-	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;
 		ip = (struct iphdr*) pktdata;
 
-#ifdef PARSE_IHL
+#if PARSE_IHL == PARSE
 		if (unlikely(ip->ihl < 5)) return XDP_DROP;
 		l4hdr = pktdata + ip->ihl * 4;
 #else
-		if (ip->ihl != 5) return XDP_DROP;
+		if (ip->ihl != 5) return PARSE_IHL;
 		l4hdr = pktdata + 5*4;
 #endif
+
 		if (ip->protocol == IP_PROTO_TCP) {
 			if (unlikely(l4hdr + sizeof(struct tcphdr) > data_end))
 				return XDP_DROP;
@@ -203,7 +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;
@@ -235,9 +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) {