Re: [PATCH bpf-next 2/2] bpf: extend bind v4/v6 selftests for mark/prio/bindtoifindex

Yonghong Song <yhs@xxxxxx> · Mon, 11 Jan 2021 12:15:14 -0800

On 1/11/21 8:17 AM, Daniel Borkmann wrote:
Extend existing cgroup bind4/bind6 tests to add coverage for setting and
retrieving SO_MARK, SO_PRIORITY and SO_BINDTOIFINDEX at the bind hook.

Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>

Ack with a minor comments below.

Acked-by: Yonghong Song <yhs@xxxxxx>

---
  .../testing/selftests/bpf/progs/bind4_prog.c  | 41 +++++++++++++++++--
  .../testing/selftests/bpf/progs/bind6_prog.c  | 41 +++++++++++++++++--
  2 files changed, 74 insertions(+), 8 deletions(-)

diff --git a/tools/testing/selftests/bpf/progs/bind4_prog.c b/tools/testing/selftests/bpf/progs/bind4_prog.c
index c6520f21f5f5..4479ac27b1d3 100644
--- a/tools/testing/selftests/bpf/progs/bind4_prog.c
+++ b/tools/testing/selftests/bpf/progs/bind4_prog.c
@@ -29,18 +29,47 @@ static __inline int bind_to_device(struct bpf_sock_addr *ctx)
  	char veth2[IFNAMSIZ] = "test_sock_addr2";
  	char missing[IFNAMSIZ] = "nonexistent_dev";
  	char del_bind[IFNAMSIZ] = "";
+	int veth1_idx, veth2_idx;
  
  	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-				&veth1, sizeof(veth1)))
+			   &veth1, sizeof(veth1)))
+		return 1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &veth1_idx, sizeof(veth1_idx)) || !veth1_idx)
  		return 1;
  	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-				&veth2, sizeof(veth2)))
+			   &veth2, sizeof(veth2)))
+		return 1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &veth2_idx, sizeof(veth2_idx)) || !veth2_idx ||
+	    veth1_idx == veth2_idx)
  		return 1;
  	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-				&missing, sizeof(missing)) != -ENODEV)
+			   &missing, sizeof(missing)) != -ENODEV)
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &veth1_idx, sizeof(veth1_idx)))
  		return 1;
  	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-				&del_bind, sizeof(del_bind)))
+			   &del_bind, sizeof(del_bind)))
+		return 1;
+
+	return 0;
+}
+
+static __inline int misc_opts(struct bpf_sock_addr *ctx, int opt)
+{
+	int old, tmp, new = 0xeb9f;
+
+	if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)) ||
+	    old == new)
+		return 1;

Here, we assume old never equals to new. it would be good to add
a comment to explicitly state this is true. Maybe in the future
somebody will try to add more misc_opts which might have conflict
here.

Alternatively, you could pass in "new" values
from user space with global variables for each option,
but that may be an overkill.

+	if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &new, sizeof(new)))
+		return 1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &tmp, sizeof(tmp)) ||
+	    tmp != new)
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)))
  		return 1;
  
  	return 0;
@@ -93,6 +122,10 @@ int bind_v4_prog(struct bpf_sock_addr *ctx)
  	if (bind_to_device(ctx))
  		return 0;
  
+	/* Test for misc socket options. */
+	if (misc_opts(ctx, SO_MARK) || misc_opts(ctx, SO_PRIORITY))
+		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 4358e44dcf47..1b4142fcdd4b 100644
--- a/tools/testing/selftests/bpf/progs/bind6_prog.c
+++ b/tools/testing/selftests/bpf/progs/bind6_prog.c
@@ -35,18 +35,47 @@ static __inline int bind_to_device(struct bpf_sock_addr *ctx)
  	char veth2[IFNAMSIZ] = "test_sock_addr2";
  	char missing[IFNAMSIZ] = "nonexistent_dev";
  	char del_bind[IFNAMSIZ] = "";
+	int veth1_idx, veth2_idx;
  
  	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-				&veth1, sizeof(veth1)))
+			   &veth1, sizeof(veth1)))
+		return 1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &veth1_idx, sizeof(veth1_idx)) || !veth1_idx)
  		return 1;
  	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-				&veth2, sizeof(veth2)))
+			   &veth2, sizeof(veth2)))
+		return 1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &veth2_idx, sizeof(veth2_idx)) || !veth2_idx ||
+	    veth1_idx == veth2_idx)
  		return 1;
  	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-				&missing, sizeof(missing)) != -ENODEV)
+			   &missing, sizeof(missing)) != -ENODEV)
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+			   &veth1_idx, sizeof(veth1_idx)))
  		return 1;
  	if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
-				&del_bind, sizeof(del_bind)))
+			   &del_bind, sizeof(del_bind)))
+		return 1;
+
+	return 0;
+}
+
+static __inline int misc_opts(struct bpf_sock_addr *ctx, int opt)
+{
+	int old, tmp, new = 0xeb9f;
+
+	if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)) ||
+	    old == new)
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &new, sizeof(new)))
+		return 1;
+	if (bpf_getsockopt(ctx, SOL_SOCKET, opt, &tmp, sizeof(tmp)) ||
+	    tmp != new)
+		return 1;
+	if (bpf_setsockopt(ctx, SOL_SOCKET, opt, &old, sizeof(old)))
  		return 1;
  
  	return 0;
@@ -107,6 +136,10 @@ int bind_v6_prog(struct bpf_sock_addr *ctx)
  	if (bind_to_device(ctx))
  		return 0;
  
+	/* Test for misc socket options. */
+	if (misc_opts(ctx, SO_MARK) || misc_opts(ctx, SO_PRIORITY))
+		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);







