Add per-source ratelimit support

[flowspec-xdp] / xdp.c

diff --git a/xdp.c b/xdp.c
index 113c4a3306d2ed7fc65b3161cfabfbf348b36690..6d1a16a239c4a449246947ee14cd43c1b74084ad 100644 (file)
--- a/xdp.c
+++ b/xdp.c
@@ -7,6 +7,8 @@
 #include <linux/icmpv6.h>
 #include <arpa/inet.h>
 
+#include "repeat_macro.h"
+
 #define NULL (void*)0
 
 /* IP flags. */
@@ -189,6 +191,44 @@ struct {
 } rate_map SEC(".maps");
 #endif
 
+// For per-source rate limiting, we have to use per-CPU hash maps as Linux
+// doesn't support spinlocks inside of a LRU_HASH (see if block in
+// map_check_btf as of Linux 5.10).
+// This isn't exactly accurate, but at least its faster.
+#if defined(V4_SRC_RATE_CNT) || defined(V6_SRC_RATE_CNT)
+struct percpu_ratelimit {
+       union {
+               int64_t sent_bytes;
+               int64_t sent_packets;
+       } rate;
+       int64_t sent_time;
+};
+#endif
+
+#define SRC_HASH_ENTRY_MAX 8192
+#define CONCAT(a, b) a##b
+#define DEFINE_SRC_RATE_MAPS(CNT, NAME) CONCAT(DEFINE_MAP, CNT)(NAME)
+
+#ifdef V4_SRC_RATE_CNT
+#define V4_SRC_MAPS DEFINE_SRC_RATE_MAPS(V4_SRC_RATE_CNT, v4_src_rate)
+struct {
+       __uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH);
+       __uint(max_entries, SRC_HASH_ENTRY_MAX);
+       __u32 *key;
+       struct percpu_ratelimit *value;
+} V4_SRC_MAPS;
+#endif
+
+#ifdef V6_SRC_RATE_CNT
+#define V6_SRC_MAPS DEFINE_SRC_RATE_MAPS(V6_SRC_RATE_CNT, v6_src_rate)
+struct {
+       __uint(type, BPF_MAP_TYPE_LRU_PERCPU_HASH);
+       __uint(max_entries, SRC_HASH_ENTRY_MAX);
+       uint128_t *key;
+       struct percpu_ratelimit *value;
+} V6_SRC_MAPS;
+#endif
+
 #ifndef HAVE_WRAPPER // Set this to call xdp_drop externally
 SEC("xdp_drop")
 #endif