[PATCH bpf-next] selftests/bpf: don't use bpf helpers in non-bpf environment

[Stanislav Fomichev]

We're using bpf_htons in test_progs.c to initialize some static
global data and I think I hit some weird case on an older compiler
which doesn't have __builtin_bswap16 (and __builtin_constant_p
expands to false).

In this case I see:
error: implicit declaration of function '__builtin_bswap16'

Let's explicitly use __constant_htons which should be exposed by the
linux/byteorder.h uapi header.

Signed-off-by: Stanislav Fomichev <s...@google.com>
---
 tools/testing/selftests/bpf/test_progs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_progs.c 
b/tools/testing/selftests/bpf/test_progs.c
index 26f1fdf3e2bf..61593d319c0e 100644
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -51,10 +51,10 @@ static struct {
        struct iphdr iph;
        struct tcphdr tcp;
 } __packed pkt_v4 = {
-       .eth.h_proto = bpf_htons(ETH_P_IP),
+       .eth.h_proto = __constant_htons(ETH_P_IP),
        .iph.ihl = 5,
        .iph.protocol = 6,
-       .iph.tot_len = bpf_htons(MAGIC_BYTES),
+       .iph.tot_len = __constant_htons(MAGIC_BYTES),
        .tcp.urg_ptr = 123,
 };
 
@@ -64,9 +64,9 @@ static struct {
        struct ipv6hdr iph;
        struct tcphdr tcp;
 } __packed pkt_v6 = {
-       .eth.h_proto = bpf_htons(ETH_P_IPV6),
+       .eth.h_proto = __constant_htons(ETH_P_IPV6),
        .iph.nexthdr = 6,
-       .iph.payload_len = bpf_htons(MAGIC_BYTES),
+       .iph.payload_len = __constant_htons(MAGIC_BYTES),
        .tcp.urg_ptr = 123,
 };
 
-- 
2.20.0.rc2.403.gdbc3b29805-goog