From: Matt Corallo <git@bluematt.me>
Date: Sat, 23 Oct 2021 17:34:00 +0000 (+0000)
Subject: Avoid inlining siphash globally to avoid hitting BPF instruction limits
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=7a55a5451c3c8bdf18adf773059c5e80474e6707;p=flowspec-xdp

Avoid inlining siphash globally to avoid hitting BPF instruction limits
---

diff --git a/siphash.h b/siphash.h
index 4c2ec7a..298a3a2 100644
--- a/siphash.h
+++ b/siphash.h
@@ -140,3 +140,15 @@ static inline uint64_t siphash(const void *in, const size_t inlen, const uint8_t
     b = v0 ^ v1 ^ v2 ^ v3;
     return b;
 }
+
+#include "rand.h"
+static uint64_t siphash_uint64_t(const uint64_t in) {
+	return siphash(&in, sizeof(uint64_t), COMPILE_TIME_RAND);
+}
+__attribute__((always_inline))
+static inline uint64_t siphash_uint32_t(const uint32_t in) {
+	return siphash_uint64_t(in);
+}
+static uint64_t siphash_uint128_t(const __uint128_t in) {
+	return siphash(&in, sizeof(__uint128_t), COMPILE_TIME_RAND);
+}
diff --git a/test.sh b/test.sh
index 0a0dd50..e17ec4b 100755
--- a/test.sh
+++ b/test.sh
@@ -7,12 +7,12 @@ COMMUNITY_DROP="
 	BGP.ext_community: (generic, 0x80060000, 0x0) (generic, 0x80070000, 0xf) (generic, 0x80090000, 0x3f)"
 
 DO_TEST() {
-	clang -g -std=c99 -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -Wno-tautological-constant-out-of-range-compare -Wno-unused-function -Wno-visibility -O3 -emit-llvm -c xdp.c -o xdp.bc
+	clang -g -std=c99 -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -Wno-unused-function -Wno-tautological-constant-out-of-range-compare -Wno-unused-function -Wno-visibility -O3 -emit-llvm -c xdp.c -o xdp.bc
 	cat xdp.bc | llc -O3 -march=bpf -filetype=obj -o xdp
 
 	echo "$TEST_PKT" >> rules.h
 	echo "#define TEST_EXP $1" >> rules.h
-	clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -Wno-tautological-constant-out-of-range-compare -O0 -g xdp.c -o xdp && ./xdp
+	clang -std=c99 -fsanitize=address -pedantic -Wall -Wextra -Wno-pointer-arith -Wno-unused-variable -Wno-unused-function -Wno-tautological-constant-out-of-range-compare -O0 -g xdp.c -o xdp && ./xdp
 }
 
 TEST_PKT='#define TEST \
diff --git a/xdp.c b/xdp.c
index e63bec3..36a45e2 100644
--- a/xdp.c
+++ b/xdp.c
@@ -226,8 +226,6 @@ struct {
 #define SRC_HASH_BUCKET_COUNT_POW 4
 #define SRC_HASH_BUCKET_COUNT (1 << SRC_HASH_BUCKET_COUNT_POW)
 
-#include "rand.h"
-
 #define CREATE_PERSRC_LOOKUP(IPV, IP_TYPE) \
 struct persrc_rate##IPV##_entry { \
 	uint64_t sent_time; \
@@ -247,7 +245,7 @@ struct persrc_rate##IPV##_ptr { \
 __attribute__((always_inline)) \
 static inline struct persrc_rate##IPV##_ptr get_v##IPV##_persrc_ratelimit(IP_TYPE key, void *map, size_t map_limit, int64_t cur_time_masked) { \
 	struct persrc_rate##IPV##_ptr res = { .rate = NULL, .lock = NULL }; \
-	uint64_t hash = siphash(&key, sizeof(key), COMPILE_TIME_RAND); \
+	uint64_t hash = siphash_##IP_TYPE(key); \
  \
 	const uint32_t map_key = hash % SRC_HASH_MAX_PARALLELISM; \
 	struct persrc_rate##IPV##_bucket *buckets = bpf_map_lookup_elem(map, &map_key); \