selftest/bpf: Use bpf_sk_lookup_{tcp, udp} in test_sock_addr

Use bpf_sk_lookup_tcp, bpf_sk_lookup_udp and bpf_sk_release helpers from
test_sock_addr programs to make sure they're available and can lookup
and release socket properly for IPv4/IPv4, TCP/UDP.

Reading from a few fields of returned struct bpf_sock is also tested.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/connect4_prog.c

@@ -21,23 +21,48 @@ int _version SEC("version") = 1;
 SEC("cgroup/connect4")
 int connect_v4_prog(struct bpf_sock_addr *ctx)
 {
+	struct bpf_sock_tuple tuple = {};
 	struct sockaddr_in sa;
+	struct bpf_sock *sk;
+
+	/* Verify that new destination is available. */
+	memset(&tuple.ipv4.saddr, 0, sizeof(tuple.ipv4.saddr));
+	memset(&tuple.ipv4.sport, 0, sizeof(tuple.ipv4.sport));
+
+	tuple.ipv4.daddr = bpf_htonl(DST_REWRITE_IP4);
+	tuple.ipv4.dport = bpf_htons(DST_REWRITE_PORT4);
+
+	if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
+		return 0;
+	else if (ctx->type == SOCK_STREAM)
+		sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof(tuple.ipv4), 0, 0);
+	else
+		sk = bpf_sk_lookup_udp(ctx, &tuple, sizeof(tuple.ipv4), 0, 0);
+
+	if (!sk)
+		return 0;
+
+	if (sk->src_ip4 != tuple.ipv4.daddr ||
+	    sk->src_port != DST_REWRITE_PORT4) {
+		bpf_sk_release(sk);
+		return 0;
+	}
+
+	bpf_sk_release(sk);
 
 	/* Rewrite destination. */
 	ctx->user_ip4 = bpf_htonl(DST_REWRITE_IP4);
 	ctx->user_port = bpf_htons(DST_REWRITE_PORT4);
 
-	if (ctx->type == SOCK_DGRAM || ctx->type == SOCK_STREAM) {
-		///* Rewrite source. */
-		memset(&sa, 0, sizeof(sa));
+	/* Rewrite source. */
+	memset(&sa, 0, sizeof(sa));
 
-		sa.sin_family = AF_INET;
-		sa.sin_port = bpf_htons(0);
-		sa.sin_addr.s_addr = bpf_htonl(SRC_REWRITE_IP4);
+	sa.sin_family = AF_INET;
+	sa.sin_port = bpf_htons(0);
+	sa.sin_addr.s_addr = bpf_htonl(SRC_REWRITE_IP4);
 
-		if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
-			return 0;
-	}
+	if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
+		return 0;
 
 	return 1;
 }

tools/testing/selftests/bpf/connect6_prog.c

@@ -29,7 +29,41 @@ int _version SEC("version") = 1;
 SEC("cgroup/connect6")
 int connect_v6_prog(struct bpf_sock_addr *ctx)
 {
+	struct bpf_sock_tuple tuple = {};
 	struct sockaddr_in6 sa;
+	struct bpf_sock *sk;
+
+	/* Verify that new destination is available. */
+	memset(&tuple.ipv6.saddr, 0, sizeof(tuple.ipv6.saddr));
+	memset(&tuple.ipv6.sport, 0, sizeof(tuple.ipv6.sport));
+
+	tuple.ipv6.daddr[0] = bpf_htonl(DST_REWRITE_IP6_0);
+	tuple.ipv6.daddr[1] = bpf_htonl(DST_REWRITE_IP6_1);
+	tuple.ipv6.daddr[2] = bpf_htonl(DST_REWRITE_IP6_2);
+	tuple.ipv6.daddr[3] = bpf_htonl(DST_REWRITE_IP6_3);
+
+	tuple.ipv6.dport = bpf_htons(DST_REWRITE_PORT6);
+
+	if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
+		return 0;
+	else if (ctx->type == SOCK_STREAM)
+		sk = bpf_sk_lookup_tcp(ctx, &tuple, sizeof(tuple.ipv6), 0, 0);
+	else
+		sk = bpf_sk_lookup_udp(ctx, &tuple, sizeof(tuple.ipv6), 0, 0);
+
+	if (!sk)
+		return 0;
+
+	if (sk->src_ip6[0] != tuple.ipv6.daddr[0] ||
+	    sk->src_ip6[1] != tuple.ipv6.daddr[1] ||
+	    sk->src_ip6[2] != tuple.ipv6.daddr[2] ||
+	    sk->src_ip6[3] != tuple.ipv6.daddr[3] ||
+	    sk->src_port != DST_REWRITE_PORT6) {
+		bpf_sk_release(sk);
+		return 0;
+	}
+
+	bpf_sk_release(sk);
 
 	/* Rewrite destination. */
 	ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_0);
@@ -39,21 +73,19 @@ int connect_v6_prog(struct bpf_sock_addr *ctx)
 
 	ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
 
-	if (ctx->type == SOCK_DGRAM || ctx->type == SOCK_STREAM) {
-		/* Rewrite source. */
-		memset(&sa, 0, sizeof(sa));
+	/* Rewrite source. */
+	memset(&sa, 0, sizeof(sa));
 
-		sa.sin6_family = AF_INET6;
-		sa.sin6_port = bpf_htons(0);
+	sa.sin6_family = AF_INET6;
+	sa.sin6_port = bpf_htons(0);
 
-		sa.sin6_addr.s6_addr32[0] = bpf_htonl(SRC_REWRITE_IP6_0);
-		sa.sin6_addr.s6_addr32[1] = bpf_htonl(SRC_REWRITE_IP6_1);
-		sa.sin6_addr.s6_addr32[2] = bpf_htonl(SRC_REWRITE_IP6_2);
-		sa.sin6_addr.s6_addr32[3] = bpf_htonl(SRC_REWRITE_IP6_3);
+	sa.sin6_addr.s6_addr32[0] = bpf_htonl(SRC_REWRITE_IP6_0);
+	sa.sin6_addr.s6_addr32[1] = bpf_htonl(SRC_REWRITE_IP6_1);
+	sa.sin6_addr.s6_addr32[2] = bpf_htonl(SRC_REWRITE_IP6_2);
+	sa.sin6_addr.s6_addr32[3] = bpf_htonl(SRC_REWRITE_IP6_3);
 
-		if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
-			return 0;
-	}
+	if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0)
+		return 0;
 
 	return 1;
 }