X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=blobdiff_plain;f=xdp.c;h=506d4224030168ff32f98032199bf144e6630ec0;hb=2400b2559ac2947300b90173a3fe25d632dba523;hp=4e4d6c6308437ed759239c1f166f982dca36256c;hpb=a8be3b609743627f58a464d7b75217a778eb4fa9;p=flowspec-xdp

diff --git a/xdp.c b/xdp.c
index 4e4d6c6..506d422 100644
--- a/xdp.c
+++ b/xdp.c
@@ -96,6 +96,7 @@ struct tcphdr {
 #elif defined(__BIG_ENDIAN)
 #define BIGEND128(a, b, c, d) ((((uint128_t)a) << 3*32) | (((uint128_t)b) << 2*32) | (((uint128_t)c) << 1*32) | (((uint128_t)d) << 0*32))
 #define HTON128(a) (a)
+#define BE16(a) ((uint16_t)a)
 #else
 #error "Need endian info"
 #endif
@@ -117,6 +118,16 @@ static const uint32_t IHL_DROP = 2;
 static const uint32_t V6FRAG_DROP = 3;
 #define STATIC_RULE_CNT 4
 
+#define DO_RETURN(reason, ret) {\
+		if (ret == XDP_DROP) { INCREMENT_MATCH(reason); } \
+		return ret; \
+	}
+
+// It seems (based on drop counts) that data_end points to the last byte, not one-past-the-end.
+// This feels strange, but some documentation suggests > here as well, so we stick with that.
+#define CHECK_LEN(start, struc) \
+	if (unlikely((void*)(start) + sizeof(struct struc) > data_end)) DO_RETURN(PKT_LEN_DROP, XDP_DROP);
+
 #ifdef TEST
 // 64 bit version of xdp_md for testing
 struct xdp_md {
@@ -133,38 +144,47 @@ static const int XDP_PASS = 0;
 static const int XDP_DROP = 1;
 
 static long drop_cnt_map[RULECNT + STATIC_RULE_CNT];
-#define DO_RETURN(reason, ret) { \
-		if (ret == XDP_DROP) drop_cnt_map[reason] += 1; \
-		return ret; \
-	}
+#define INCREMENT_MATCH(reason) { drop_cnt_map[reason] += 1; drop_cnt_map[reason] += data_end - pktdata; }
 
 #else
 #include <linux/bpf.h>
 #include <bpf/bpf_helpers.h>
 
-struct bpf_map_def SEC("maps") drop_cnt_map = {
-	.type = BPF_MAP_TYPE_PERCPU_ARRAY,
-	.key_size = sizeof(uint32_t),
-	.value_size = sizeof(long),
-	.max_entries = RULECNT + STATIC_RULE_CNT,
+struct match_counter {
+	uint64_t bytes;
+	uint64_t packets;
 };
-#define DO_RETURN(reason, ret) {\
-		if (ret == XDP_DROP) { \
-			long *value = bpf_map_lookup_elem(&drop_cnt_map, &reason); \
-			if (value) \
-				*value += 1; \
-		} \
-		return XDP_DROP; \
-	}
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(max_entries, RULECNT + STATIC_RULE_CNT);
+	__u32 *key;
+	struct match_counter *value;
+} drop_cnt_map SEC(".maps");
+
+#define INCREMENT_MATCH(reason) { \
+	struct match_counter *value = bpf_map_lookup_elem(&drop_cnt_map, &reason); \
+	if (value) { \
+		value->bytes += data_end - pktdata; \
+		value->packets += 1; \
+	} \
+}
 
-SEC("xdp_drop")
+#ifdef RATE_CNT
+struct ratelimit {
+	struct bpf_spin_lock lock;
+	int64_t sent_bytes;
+	int64_t sent_time;
+};
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, RATE_CNT);
+	__u32 *key;
+	struct ratelimit *value;
+} rate_map SEC(".maps");
 #endif
 
-// It seems (based on drop counts) that data_end points to the last byte, not one-past-the-end.
-// This feels strange, but some documentation suggests > here as well, so we stick with that.
-#define CHECK_LEN(start, struc) \
-	if (unlikely((void*)(start) + sizeof(struct struc) > data_end)) DO_RETURN(PKT_LEN_DROP, XDP_DROP);
-
+SEC("xdp_drop")
+#endif
 int xdp_drop_prog(struct xdp_md *ctx)
 {
 	const void *const data_end = (void *)(size_t)ctx->data_end;
@@ -173,30 +193,32 @@ int xdp_drop_prog(struct xdp_md *ctx)
 	unsigned short eth_proto;
 
 	{
+		// DO_RETURN in CHECK_LEN relies on pktdata being set to calculate packet length.
+		// That said, we don't want to overflow, so just set packet length to 0 here.
+		pktdata = data_end;
 		CHECK_LEN((size_t)ctx->data, ethhdr);
 		const struct ethhdr *const eth = (void*)(size_t)ctx->data;
+		pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr);
 
 #if PARSE_8021Q == PARSE
 		if (likely(eth->h_proto == BE16(ETH_P_8021Q))) {
 			CHECK_LEN((size_t)ctx->data, ethhdr_vlan);
 			const struct ethhdr_vlan *const eth_vlan = (void*)(size_t)ctx->data;
-
+			pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr_vlan);
 #ifdef REQ_8021Q
 			if (unlikely((eth_vlan->tci & BE16(0xfff)) != BE16(REQ_8021Q)))
 				DO_RETURN(VLAN_DROP, 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))) {
+			pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr_vlan);
 			DO_RETURN(VLAN_DROP, PARSE_8021Q);
 #endif
 		} else {
 #ifdef REQ_8021Q
 			DO_RETURN(VLAN_DROP, XDP_DROP);
 #else
-			pktdata = (const void *)(long)ctx->data + sizeof(struct ethhdr);
 			eth_proto = eth->h_proto;
 #endif
 		}
@@ -210,7 +232,7 @@ int xdp_drop_prog(struct xdp_md *ctx)
 #ifdef NEED_V4_PARSE
 	if (eth_proto == BE16(ETH_P_IP)) {
 		CHECK_LEN(pktdata, iphdr);
-		const struct iphdr *ip = (struct iphdr*) pktdata;
+		struct iphdr *ip = (struct iphdr*) pktdata;
 
 #if PARSE_IHL == PARSE
 		if (unlikely(ip->ihl < 5)) DO_RETURN(IHL_DROP, XDP_DROP);
@@ -246,7 +268,7 @@ int xdp_drop_prog(struct xdp_md *ctx)
 #ifdef NEED_V6_PARSE
 	if (eth_proto == BE16(ETH_P_IPV6)) {
 		CHECK_LEN(pktdata, ip6hdr);
-		const struct ip6hdr *ip6 = (struct ip6hdr*) pktdata;
+		struct ip6hdr *ip6 = (struct ip6hdr*) pktdata;
 
 		l4hdr = pktdata + 40;
 
@@ -298,7 +320,7 @@ int xdp_drop_prog(struct xdp_md *ctx)
 #include <assert.h>
 #include <string.h>
 
-const char d[] = TEST;
+char d[] = TEST;
 int main() {
 	struct xdp_md test = {
 		.data = (uint64_t)d,