selftests/bpf: introduce bpf_cpu_to_be64 and bpf_be64_to_cpu

test_lwt_seg6local and test_seg6_loop use custom 64-bit endianness
conversion macros. Centralize their definitions in bpf_endian.h in order
to reduce code duplication. This will also be useful when bpf_endian.h
is promoted to an offical libbpf header.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/testing/selftests/bpf/bpf_endian.h

@@ -29,6 +29,10 @@
 # define __bpf_htonl(x)			__builtin_bswap32(x)
 # define __bpf_constant_ntohl(x)	___constant_swab32(x)
 # define __bpf_constant_htonl(x)	___constant_swab32(x)
+# define __bpf_be64_to_cpu(x)		__builtin_bswap64(x)
+# define __bpf_cpu_to_be64(x)		__builtin_bswap64(x)
+# define __bpf_constant_be64_to_cpu(x)	___constant_swab64(x)
+# define __bpf_constant_cpu_to_be64(x)	___constant_swab64(x)
 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 # define __bpf_ntohs(x)			(x)
 # define __bpf_htons(x)			(x)
@@ -38,6 +42,10 @@
 # define __bpf_htonl(x)			(x)
 # define __bpf_constant_ntohl(x)	(x)
 # define __bpf_constant_htonl(x)	(x)
+# define __bpf_be64_to_cpu(x)		(x)
+# define __bpf_cpu_to_be64(x)		(x)
+# define __bpf_constant_be64_to_cpu(x)  (x)
+# define __bpf_constant_cpu_to_be64(x)  (x)
 #else
 # error "Fix your compiler's __BYTE_ORDER__?!"
 #endif
@@ -54,5 +62,11 @@
 #define bpf_ntohl(x)				\
 	(__builtin_constant_p(x) ?		\
 	 __bpf_constant_ntohl(x) : __bpf_ntohl(x))
+#define bpf_cpu_to_be64(x)			\
+	(__builtin_constant_p(x) ?		\
+	 __bpf_constant_cpu_to_be64(x) : __bpf_cpu_to_be64(x))
+#define bpf_be64_to_cpu(x)			\
+	(__builtin_constant_p(x) ?		\
+	 __bpf_constant_be64_to_cpu(x) : __bpf_be64_to_cpu(x))
 
 #endif /* __BPF_ENDIAN__ */

tools/testing/selftests/bpf/progs/test_lwt_seg6local.c

@@ -12,10 +12,6 @@
 
 #define SR6_FLAG_ALERT (1 << 4)
 
-#define htonll(x) ((bpf_htonl(1)) == 1 ? (x) : ((uint64_t)bpf_htonl((x) & \
-				0xFFFFFFFF) << 32) | bpf_htonl((x) >> 32))
-#define ntohll(x) ((bpf_ntohl(1)) == 1 ? (x) : ((uint64_t)bpf_ntohl((x) & \
-				0xFFFFFFFF) << 32) | bpf_ntohl((x) >> 32))
 #define BPF_PACKET_HEADER __attribute__((packed))
 
 struct ip6_t {
@@ -276,8 +272,8 @@ int has_egr_tlv(struct __sk_buff *skb, struct ip6_srh_t *srh)
 			return 0;
 
 		// check if egress TLV value is correct
-		if (ntohll(egr_addr.hi) == 0xfd00000000000000 &&
-				ntohll(egr_addr.lo) == 0x4)
+		if (bpf_be64_to_cpu(egr_addr.hi) == 0xfd00000000000000 &&
+		    bpf_be64_to_cpu(egr_addr.lo) == 0x4)
 			return 1;
 	}
 
@@ -308,8 +304,8 @@ int __encap_srh(struct __sk_buff *skb)
 
 	#pragma clang loop unroll(full)
 	for (unsigned long long lo = 0; lo < 4; lo++) {
-		seg->lo = htonll(4 - lo);
-		seg->hi = htonll(hi);
+		seg->lo = bpf_cpu_to_be64(4 - lo);
+		seg->hi = bpf_cpu_to_be64(hi);
 		seg = (struct ip6_addr_t *)((char *)seg + sizeof(*seg));
 	}
 
@@ -349,8 +345,8 @@ int __add_egr_x(struct __sk_buff *skb)
 	if (err)
 		return BPF_DROP;
 
-	addr.lo = htonll(lo);
-	addr.hi = htonll(hi);
+	addr.lo = bpf_cpu_to_be64(lo);
+	addr.hi = bpf_cpu_to_be64(hi);
 	err = bpf_lwt_seg6_action(skb, SEG6_LOCAL_ACTION_END_X,
 				  (void *)&addr, sizeof(addr));
 	if (err)

tools/testing/selftests/bpf/progs/test_seg6_loop.c

@@ -12,10 +12,6 @@
 
 #define SR6_FLAG_ALERT (1 << 4)
 
-#define htonll(x) ((bpf_htonl(1)) == 1 ? (x) : ((uint64_t)bpf_htonl((x) & \
-				0xFFFFFFFF) << 32) | bpf_htonl((x) >> 32))
-#define ntohll(x) ((bpf_ntohl(1)) == 1 ? (x) : ((uint64_t)bpf_ntohl((x) & \
-				0xFFFFFFFF) << 32) | bpf_ntohl((x) >> 32))
 #define BPF_PACKET_HEADER __attribute__((packed))
 
 struct ip6_t {
@@ -251,8 +247,8 @@ int __add_egr_x(struct __sk_buff *skb)
 	if (err)
 		return BPF_DROP;
 
-	addr.lo = htonll(lo);
-	addr.hi = htonll(hi);
+	addr.lo = bpf_cpu_to_be64(lo);
+	addr.hi = bpf_cpu_to_be64(hi);
 	err = bpf_lwt_seg6_action(skb, SEG6_LOCAL_ACTION_END_X,
 				  (void *)&addr, sizeof(addr));
 	if (err)