Subject: [PATCH bpf-next 3/3] selftests/bpf: extend bind{4,6} programs with a call to bpf_setsockopt

From: Stanislav Fomichev <[email-masked]>
Date: Wed, 2 Dec 2020 09:25:16 -0800

To make sure it doesn't trigger sock_owned_by_me splat.

Signed-off-by: Stanislav Fomichev <[email-masked]>
Acked-by: Andrii Nakryiko <[email-masked]>
---
 .../testing/selftests/bpf/progs/bind4_prog.c  | 31 +++++++++++++++++++
 .../testing/selftests/bpf/progs/bind6_prog.c  | 31 +++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/tools/testing/selftests/bpf/progs/bind4_prog.c b/tools/testing/selftests/bpf/progs/bind4_prog.c
index 0951302a984a..c6520f21f5f5 100644
--- a/tools/testing/selftests/bpf/progs/bind4_prog.c
+++ b/tools/testing/selftests/bpf/progs/bind4_prog.c
@@ -19,6 +19,33 @@
 #define SERV4_REWRITE_IP	0x7f000001U /* 127.0.0.1 */
 #define SERV4_REWRITE_PORT	4444
 
+#ifndef IFNAMSIZ
+#define IFNAMSIZ 16
+#endif
+
+static __inline int bind_to_device(struct bpf_sock_addr *ctx)
+{
+	char veth1[IFNAMSIZ] = "test_sock_addr1";
+	char veth2[IFNAMSIZ] = "test_sock_addr2";
+	char missing[IFNAMSIZ] = "nonexistent_dev";
+	char del_bind[IFNAMSIZ] = "";
+
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+				&veth1, sizeof(veth1)))
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+				&veth2, sizeof(veth2)))
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+				&missing, sizeof(missing)) != -ENODEV)
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+				&del_bind, sizeof(del_bind)))
+		return 1;
+
+	return 0;
+}
+
 SEC("cgroup/bind4")
 int bind_v4_prog(struct bpf_sock_addr *ctx)
 {
@@ -62,6 +89,10 @@ int bind_v4_prog(struct bpf_sock_addr *ctx)
 	if (ctx->user_ip4 != user_ip4)
 		return 0;
 
+	/* Bind to device and unbind it. */
+	if (bind_to_device(ctx))
+		return 0;
+
 	ctx->user_ip4 = bpf_htonl(SERV4_REWRITE_IP);
 	ctx->user_port = bpf_htons(SERV4_REWRITE_PORT);
 
diff --git a/tools/testing/selftests/bpf/progs/bind6_prog.c b/tools/testing/selftests/bpf/progs/bind6_prog.c
index 16da1cf85418..4358e44dcf47 100644
--- a/tools/testing/selftests/bpf/progs/bind6_prog.c
+++ b/tools/testing/selftests/bpf/progs/bind6_prog.c
@@ -25,6 +25,33 @@
 #define SERV6_REWRITE_IP_3	0x00000001
 #define SERV6_REWRITE_PORT	6666
 
+#ifndef IFNAMSIZ
+#define IFNAMSIZ 16
+#endif
+
+static __inline int bind_to_device(struct bpf_sock_addr *ctx)
+{
+	char veth1[IFNAMSIZ] = "test_sock_addr1";
+	char veth2[IFNAMSIZ] = "test_sock_addr2";
+	char missing[IFNAMSIZ] = "nonexistent_dev";
+	char del_bind[IFNAMSIZ] = "";
+
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+				&veth1, sizeof(veth1)))
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+				&veth2, sizeof(veth2)))
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+				&missing, sizeof(missing)) != -ENODEV)
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+				&del_bind, sizeof(del_bind)))
+		return 1;
+
+	return 0;
+}
+
 SEC("cgroup/bind6")
 int bind_v6_prog(struct bpf_sock_addr *ctx)
 {
@@ -76,6 +103,10 @@ int bind_v6_prog(struct bpf_sock_addr *ctx)
 			return 0;
 	}
 
+	/* Bind to device and unbind it. */
+	if (bind_to_device(ctx))
+		return 0;
+
 	ctx->user_ip6[0] = bpf_htonl(SERV6_REWRITE_IP_0);
 	ctx->user_ip6[1] = bpf_htonl(SERV6_REWRITE_IP_1);
 	ctx->user_ip6[2] = bpf_htonl(SERV6_REWRITE_IP_2);
-- 
2.29.2.454.gaff20da3a2-goog