selftests: bpf: Convert sk_lookup ctx access tests to PROG_TEST_RUN

Convert the selftests for sk_lookup narrow context access to use
PROG_TEST_RUN instead of creating actual sockets. This ensures that
ctx is populated correctly when using PROG_TEST_RUN.

Assert concrete values since we now control remote_ip and remote_port.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210303101816.36774-4-lmb@cloudflare.com

1 files changed, 41 insertions, 21 deletions

diff --git a/tools/testing/selftests/bpf/progs/test_sk_lookup.c b/tools/testing/selftests/bpf/progs/test_sk_lookup.c
index 1032b292af5b..ac6f7f205e25 100644
--- a/tools/testing/selftests/bpf/progs/test_sk_lookup.c
+++ b/tools/testing/selftests/bpf/progs/test_sk_lookup.c
@@ -64,6 +64,10 @@ static const int PROG_DONE = 1;
 static const __u32 KEY_SERVER_A = SERVER_A;
 static const __u32 KEY_SERVER_B = SERVER_B;
 
+static const __u16 SRC_PORT = bpf_htons(8008);
+static const __u32 SRC_IP4 = IP4(127, 0, 0, 2);
+static const __u32 SRC_IP6[] = IP6(0xfd000000, 0x0, 0x0, 0x00000002);
+
 static const __u16 DST_PORT = 7007; /* Host byte order */
 static const __u32 DST_IP4 = IP4(127, 0, 0, 1);
 static const __u32 DST_IP6[] = IP6(0xfd000000, 0x0, 0x0, 0x00000001);
@@ -398,11 +402,12 @@ int ctx_narrow_access(struct bpf_sk_lookup *ctx)
 	if (LSW(ctx->protocol, 0) != IPPROTO_TCP)
 		return SK_DROP;
 
-	/* Narrow loads from remote_port field. Expect non-0 value. */
-	if (LSB(ctx->remote_port, 0) == 0 && LSB(ctx->remote_port, 1) == 0 &&
-	    LSB(ctx->remote_port, 2) == 0 && LSB(ctx->remote_port, 3) == 0)
+	/* Narrow loads from remote_port field. Expect SRC_PORT. */
+	if (LSB(ctx->remote_port, 0) != ((SRC_PORT >> 0) & 0xff) ||
+	    LSB(ctx->remote_port, 1) != ((SRC_PORT >> 8) & 0xff) ||
+	    LSB(ctx->remote_port, 2) != 0 || LSB(ctx->remote_port, 3) != 0)
 		return SK_DROP;
-	if (LSW(ctx->remote_port, 0) == 0)
+	if (LSW(ctx->remote_port, 0) != SRC_PORT)
 		return SK_DROP;
 
 	/* Narrow loads from local_port field. Expect DST_PORT. */
@@ -415,11 +420,14 @@ int ctx_narrow_access(struct bpf_sk_lookup *ctx)
 
 	/* Narrow loads from IPv4 fields */
 	if (v4) {
-		/* Expect non-0.0.0.0 in remote_ip4 */
-		if (LSB(ctx->remote_ip4, 0) == 0 && LSB(ctx->remote_ip4, 1) == 0 &&
-		    LSB(ctx->remote_ip4, 2) == 0 && LSB(ctx->remote_ip4, 3) == 0)
+		/* Expect SRC_IP4 in remote_ip4 */
+		if (LSB(ctx->remote_ip4, 0) != ((SRC_IP4 >> 0) & 0xff) ||
+		    LSB(ctx->remote_ip4, 1) != ((SRC_IP4 >> 8) & 0xff) ||
+		    LSB(ctx->remote_ip4, 2) != ((SRC_IP4 >> 16) & 0xff) ||
+		    LSB(ctx->remote_ip4, 3) != ((SRC_IP4 >> 24) & 0xff))
 			return SK_DROP;
-		if (LSW(ctx->remote_ip4, 0) == 0 && LSW(ctx->remote_ip4, 1) == 0)
+		if (LSW(ctx->remote_ip4, 0) != ((SRC_IP4 >> 0) & 0xffff) ||
+		    LSW(ctx->remote_ip4, 1) != ((SRC_IP4 >> 16) & 0xffff))
 			return SK_DROP;
 
 		/* Expect DST_IP4 in local_ip4 */
@@ -448,20 +456,32 @@ int ctx_narrow_access(struct bpf_sk_lookup *ctx)
 
 	/* Narrow loads from IPv6 fields */
 	if (!v4) {
-		/* Expect non-:: IP in remote_ip6 */
-		if (LSB(ctx->remote_ip6[0], 0) == 0 && LSB(ctx->remote_ip6[0], 1) == 0 &&
-		    LSB(ctx->remote_ip6[0], 2) == 0 && LSB(ctx->remote_ip6[0], 3) == 0 &&
-		    LSB(ctx->remote_ip6[1], 0) == 0 && LSB(ctx->remote_ip6[1], 1) == 0 &&
-		    LSB(ctx->remote_ip6[1], 2) == 0 && LSB(ctx->remote_ip6[1], 3) == 0 &&
-		    LSB(ctx->remote_ip6[2], 0) == 0 && LSB(ctx->remote_ip6[2], 1) == 0 &&
-		    LSB(ctx->remote_ip6[2], 2) == 0 && LSB(ctx->remote_ip6[2], 3) == 0 &&
-		    LSB(ctx->remote_ip6[3], 0) == 0 && LSB(ctx->remote_ip6[3], 1) == 0 &&
-		    LSB(ctx->remote_ip6[3], 2) == 0 && LSB(ctx->remote_ip6[3], 3) == 0)
+		/* Expect SRC_IP6 in remote_ip6 */
+		if (LSB(ctx->remote_ip6[0], 0) != ((SRC_IP6[0] >> 0) & 0xff) ||
+		    LSB(ctx->remote_ip6[0], 1) != ((SRC_IP6[0] >> 8) & 0xff) ||
+		    LSB(ctx->remote_ip6[0], 2) != ((SRC_IP6[0] >> 16) & 0xff) ||
+		    LSB(ctx->remote_ip6[0], 3) != ((SRC_IP6[0] >> 24) & 0xff) ||
+		    LSB(ctx->remote_ip6[1], 0) != ((SRC_IP6[1] >> 0) & 0xff) ||
+		    LSB(ctx->remote_ip6[1], 1) != ((SRC_IP6[1] >> 8) & 0xff) ||
+		    LSB(ctx->remote_ip6[1], 2) != ((SRC_IP6[1] >> 16) & 0xff) ||
+		    LSB(ctx->remote_ip6[1], 3) != ((SRC_IP6[1] >> 24) & 0xff) ||
+		    LSB(ctx->remote_ip6[2], 0) != ((SRC_IP6[2] >> 0) & 0xff) ||
+		    LSB(ctx->remote_ip6[2], 1) != ((SRC_IP6[2] >> 8) & 0xff) ||
+		    LSB(ctx->remote_ip6[2], 2) != ((SRC_IP6[2] >> 16) & 0xff) ||
+		    LSB(ctx->remote_ip6[2], 3) != ((SRC_IP6[2] >> 24) & 0xff) ||
+		    LSB(ctx->remote_ip6[3], 0) != ((SRC_IP6[3] >> 0) & 0xff) ||
+		    LSB(ctx->remote_ip6[3], 1) != ((SRC_IP6[3] >> 8) & 0xff) ||
+		    LSB(ctx->remote_ip6[3], 2) != ((SRC_IP6[3] >> 16) & 0xff) ||
+		    LSB(ctx->remote_ip6[3], 3) != ((SRC_IP6[3] >> 24) & 0xff))
 			return SK_DROP;
-		if (LSW(ctx->remote_ip6[0], 0) == 0 && LSW(ctx->remote_ip6[0], 1) == 0 &&
-		    LSW(ctx->remote_ip6[1], 0) == 0 && LSW(ctx->remote_ip6[1], 1) == 0 &&
-		    LSW(ctx->remote_ip6[2], 0) == 0 && LSW(ctx->remote_ip6[2], 1) == 0 &&
-		    LSW(ctx->remote_ip6[3], 0) == 0 && LSW(ctx->remote_ip6[3], 1) == 0)
+		if (LSW(ctx->remote_ip6[0], 0) != ((SRC_IP6[0] >> 0) & 0xffff) ||
+		    LSW(ctx->remote_ip6[0], 1) != ((SRC_IP6[0] >> 16) & 0xffff) ||
+		    LSW(ctx->remote_ip6[1], 0) != ((SRC_IP6[1] >> 0) & 0xffff) ||
+		    LSW(ctx->remote_ip6[1], 1) != ((SRC_IP6[1] >> 16) & 0xffff) ||
+		    LSW(ctx->remote_ip6[2], 0) != ((SRC_IP6[2] >> 0) & 0xffff) ||
+		    LSW(ctx->remote_ip6[2], 1) != ((SRC_IP6[2] >> 16) & 0xffff) ||
+		    LSW(ctx->remote_ip6[3], 0) != ((SRC_IP6[3] >> 0) & 0xffff) ||
+		    LSW(ctx->remote_ip6[3], 1) != ((SRC_IP6[3] >> 16) & 0xffff))
 			return SK_DROP;
 		/* Expect DST_IP6 in local_ip6 */
 		if (LSB(ctx->local_ip6[0], 0) != ((DST_IP6[0] >> 0) & 0xff) ||