X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=xdp.c;h=b93b16936bdfdde7f72d6e84277a95cda8e501cf;hb=b6de860db504248c8eb737887e10a334a2b5c298;hp=87b7eb5edae258cfbe695c21ac30ff4ae9c4a9a5;hpb=a0ba2a08e5f98bc4f731b384ac13e11f610ffdda;p=flowspec-xdp

diff --git a/xdp.c b/xdp.c
index 87b7eb5..b93b169 100644
--- a/xdp.c
+++ b/xdp.c
@@ -18,7 +18,8 @@
 #define IP_PROTO_TCP 6
 #define IP_PROTO_UDP 17
 #define IP_PROTO_ICMP 1
-#define IP_PROTO_ICMPV6 58
+#define IP6_PROTO_ICMPV6 58
+#define IP6_PROTO_FRAG 44
 
 typedef __uint128_t uint128_t;
 
@@ -43,6 +44,15 @@ struct ip6hdr {
 	uint128_t	daddr;
 } __attribute__((packed));
 
+#define IP6_MF 1
+#define IP6_FRAGOFF 0xfff8
+struct ip6_fraghdr {
+	uint8_t nexthdr;
+	uint8_t _reserved;
+	uint16_t frag_off; // BE low 3 bits flags, last is "more frags"
+	uint32_t id;
+} __attribute__((packed));
+
 // Our own ethhdr with optional vlan tags
 struct ethhdr_vlan {
 	unsigned char	h_dest[ETH_ALEN];	/* destination eth addr	*/
@@ -94,10 +104,13 @@ 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)
+#define likely(a) __builtin_expect(a, 1)
+
 #ifdef TEST
 // 64 bit version of xdp_md for testing
 struct xdp_md {
@@ -126,23 +139,27 @@ int xdp_drop_prog(struct xdp_md *ctx)
 	unsigned short eth_proto;
 
 	{
-		if ((void*)(size_t)ctx->data + sizeof(struct ethhdr) > data_end)
+		if (unlikely((void*)(size_t)ctx->data + sizeof(struct ethhdr) > data_end))
 			return XDP_DROP;
 		const struct ethhdr *const eth = (void*)(size_t)ctx->data;
 
-#ifdef PARSE_8021Q
-		if (eth->h_proto == BE16(ETH_P_8021Q)) {
-			if ((void*)(size_t)ctx->data + sizeof(struct ethhdr_vlan) > data_end)
+#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;
 			const struct ethhdr_vlan *const eth_vlan = (void*)(size_t)ctx->data;
 
 #ifdef REQ_8021Q
-			if ((eth_vlan->tci & BE16(0xfff)) != BE16(REQ_8021Q))
+			if (unlikely((eth_vlan->tci & BE16(0xfff)) != BE16(REQ_8021Q)))
 				return XDP_DROP;
 #endif
 
 			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;
@@ -151,67 +168,86 @@ 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;
-	const struct icmphdr *icmp = NULL;
-	const struct icmp6hdr *icmpv6 = 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;
+#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 (pktdata + sizeof(struct iphdr) > data_end)
+		if (unlikely(pktdata + sizeof(struct iphdr) > data_end))
 			return XDP_DROP;
 		ip = (struct iphdr*) pktdata;
 
-#ifdef PARSE_IHL
-		if (ip->ihl < 5) return XDP_DROP;
+#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 (l4hdr + sizeof(struct tcphdr) > data_end)
+			if (unlikely(l4hdr + sizeof(struct tcphdr) > data_end))
 				return XDP_DROP;
 			tcp = (struct tcphdr*) l4hdr;
 		} else if (ip->protocol == IP_PROTO_UDP) {
-			if (l4hdr + sizeof(struct udphdr) > data_end)
+			if (unlikely(l4hdr + sizeof(struct udphdr) > data_end))
 				return XDP_DROP;
 			udp = (struct udphdr*) l4hdr;
 		} else if (ip->protocol == IP_PROTO_ICMP) {
-			if (l4hdr + sizeof(struct icmphdr) > data_end)
+			if (unlikely(l4hdr + sizeof(struct icmphdr) > data_end))
 				return XDP_DROP;
 			icmp = (struct icmphdr*) l4hdr;
 		}
-	} else if (eth_proto == BE16(ETH_P_IPV6)) {
-		if (pktdata + sizeof(struct ip6hdr) > data_end)
+	}
+#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;
 
 		l4hdr = pktdata + 40;
-		if (ip6->nexthdr == IP_PROTO_TCP) {
-			if (l4hdr + sizeof(struct tcphdr) > data_end)
+
+		uint8_t v6nexthdr;
+		if (ip6->nexthdr == IP6_PROTO_FRAG) {
+			if (unlikely(l4hdr + sizeof(struct ip6_fraghdr) > data_end))
+				return XDP_DROP;
+			frag6 = (struct ip6_fraghdr*) l4hdr;
+			l4hdr = l4hdr + sizeof(struct ip6_fraghdr);
+			v6nexthdr = frag6->nexthdr;
+		} else {
+			v6nexthdr = ip6->nexthdr;
+		}
+
+		if (v6nexthdr == IP_PROTO_TCP) {
+			if (unlikely(l4hdr + sizeof(struct tcphdr) > data_end))
 				return XDP_DROP;
 			tcp = (struct tcphdr*) l4hdr;
-		} else if (ip6->nexthdr == IP_PROTO_UDP) {
-			if (l4hdr + sizeof(struct udphdr) > data_end)
+		} else if (v6nexthdr == IP_PROTO_UDP) {
+			if (unlikely(l4hdr + sizeof(struct udphdr) > data_end))
 				return XDP_DROP;
 			udp = (struct udphdr*) l4hdr;
-		} else if (ip6->nexthdr == IP_PROTO_ICMPV6) {
-			if (l4hdr + sizeof(struct icmp6hdr) > data_end)
+		} else if (v6nexthdr == IP6_PROTO_ICMPV6) {
+			if (unlikely(l4hdr + sizeof(struct icmp6hdr) > data_end))
 				return XDP_DROP;
 			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) {