[PATCH v2 bpf-next 0/3] bpf: net: Detach BPF prog from reuseport sk

[PATCH v2 bpf-next 0/3] bpf: net: Detach BPF prog from reuseport sk

[Martin KaFai Lau]

v2:
Copy asm-generic/socket.h to tools/ in the new patch 2 (Stanislav Fomichev)

This patch adds SO_DETACH_REUSEPORT_BPF to detach BPF prog from
reuseport sk.

Martin KaFai Lau (3):
  bpf: net: Add SO_DETACH_REUSEPORT_BPF
  bpf: Sync asm-generic/socket.h to tools/
  bpf: Add test for SO_REUSEPORT_DETACH_BPF

 arch/alpha/include/uapi/asm/socket.h          |  2 +
 arch/mips/include/uapi/asm/socket.h           |  2 +
 arch/parisc/include/uapi/asm/socket.h         |  2 +
 arch/sparc/include/uapi/asm/socket.h          |  2 +
 include/net/sock_reuseport.h                  |  2 +
 include/uapi/asm-generic/socket.h             |  2 +
 net/core/sock.c                               |  4 ++
 net/core/sock_reuseport.c                     | 24 +++++++++
 .../include}/uapi/asm-generic/socket.h        |  2 +
 .../selftests/bpf/test_select_reuseport.c     | 54 +++++++++++++++++++
 10 files changed, 96 insertions(+)
 copy {include => tools/include}/uapi/asm-generic/socket.h (98%)

-- 
2.17.1

[PATCH v2 bpf-next 1/3] bpf: net: Add SO_DETACH_REUSEPORT_BPF

[Martin KaFai Lau]

There is SO_ATTACH_REUSEPORT_[CE]BPF but there is no DETACH.
This patch adds SO_DETACH_REUSEPORT_BPF sockopt.  The same
sockopt can be used to undo both SO_ATTACH_REUSEPORT_[CE]BPF.

reseport_detach_prog() is added and it is mostly a mirror
of the existing reuseport_attach_prog().  The differences are,
it does not call reuseport_alloc() and returns -ENOENT when
there is no old prog.

Cc: Craig Gallek <kraig@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 arch/alpha/include/uapi/asm/socket.h  |  2 ++
 arch/mips/include/uapi/asm/socket.h   |  2 ++
 arch/parisc/include/uapi/asm/socket.h |  2 ++
 arch/sparc/include/uapi/asm/socket.h  |  2 ++
 include/net/sock_reuseport.h          |  2 ++
 include/uapi/asm-generic/socket.h     |  2 ++
 net/core/sock.c                       |  4 ++++
 net/core/sock_reuseport.c             | 24 ++++++++++++++++++++++++
 8 files changed, 40 insertions(+)

diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index 976e89b116e5..de6c4df61082 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -122,6 +122,8 @@
 #define SO_RCVTIMEO_NEW         66
 #define SO_SNDTIMEO_NEW         67
 
+#define SO_DETACH_REUSEPORT_BPF 68
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64
diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
index d41765cfbc6e..d0a9ed2ca2d6 100644
--- a/arch/mips/include/uapi/asm/socket.h
+++ b/arch/mips/include/uapi/asm/socket.h
@@ -133,6 +133,8 @@
 #define SO_RCVTIMEO_NEW         66
 #define SO_SNDTIMEO_NEW         67
 
+#define SO_DETACH_REUSEPORT_BPF 68
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64
diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
index 66c5dd245ac7..10173c32195e 100644
--- a/arch/parisc/include/uapi/asm/socket.h
+++ b/arch/parisc/include/uapi/asm/socket.h
@@ -114,6 +114,8 @@
 #define SO_RCVTIMEO_NEW         0x4040
 #define SO_SNDTIMEO_NEW         0x4041
 
+#define SO_DETACH_REUSEPORT_BPF 0x4042
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64
diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
index 9265a9eece15..1895ac112a24 100644
--- a/arch/sparc/include/uapi/asm/socket.h
+++ b/arch/sparc/include/uapi/asm/socket.h
@@ -115,6 +115,8 @@
 #define SO_RCVTIMEO_NEW          0x0044
 #define SO_SNDTIMEO_NEW          0x0045
 
+#define SO_DETACH_REUSEPORT_BPF  0x0046
+
 #if !defined(__KERNEL__)
 
 
diff --git a/include/net/sock_reuseport.h b/include/net/sock_reuseport.h
index 8a5f70c7cdf2..d9112de85261 100644
--- a/include/net/sock_reuseport.h
+++ b/include/net/sock_reuseport.h
@@ -35,6 +35,8 @@ extern struct sock *reuseport_select_sock(struct sock *sk,
 					  struct sk_buff *skb,
 					  int hdr_len);
 extern int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog);
+extern int reuseport_detach_prog(struct sock *sk);
+
 int reuseport_get_id(struct sock_reuseport *reuse);
 
 #endif  /* _SOCK_REUSEPORT_H */
diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
index 8c1391c89171..77f7c1638eb1 100644
--- a/include/uapi/asm-generic/socket.h
+++ b/include/uapi/asm-generic/socket.h
@@ -117,6 +117,8 @@
 #define SO_RCVTIMEO_NEW         66
 #define SO_SNDTIMEO_NEW         67
 
+#define SO_DETACH_REUSEPORT_BPF 68
+
 #if !defined(__KERNEL__)
 
 #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
diff --git a/net/core/sock.c b/net/core/sock.c
index 75b1c950b49f..06be30737b69 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1045,6 +1045,10 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 		}
 		break;
 
+	case SO_DETACH_REUSEPORT_BPF:
+		ret = reuseport_detach_prog(sk);
+		break;
+
 	case SO_DETACH_FILTER:
 		ret = sk_detach_filter(sk);
 		break;
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
index dc4aefdf2a08..e0cb29469fa7 100644
--- a/net/core/sock_reuseport.c
+++ b/net/core/sock_reuseport.c
@@ -332,3 +332,27 @@ int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog)
 	return 0;
 }
 EXPORT_SYMBOL(reuseport_attach_prog);
+
+int reuseport_detach_prog(struct sock *sk)
+{
+	struct sock_reuseport *reuse;
+	struct bpf_prog *old_prog;
+
+	if (!rcu_access_pointer(sk->sk_reuseport_cb))
+		return sk->sk_reuseport ? -ENOENT : -EINVAL;
+
+	spin_lock_bh(&reuseport_lock);
+	reuse = rcu_dereference_protected(sk->sk_reuseport_cb,
+					  lockdep_is_held(&reuseport_lock));
+	old_prog = rcu_dereference_protected(reuse->prog,
+					     lockdep_is_held(&reuseport_lock));
+	RCU_INIT_POINTER(reuse->prog, NULL);
+	spin_unlock_bh(&reuseport_lock);
+
+	if (!old_prog)
+		return -ENOENT;
+
+	sk_reuseport_prog_free(old_prog);
+	return 0;
+}
+EXPORT_SYMBOL(reuseport_detach_prog);
-- 
2.17.1

Re: [PATCH v2 bpf-next 1/3] bpf: net: Add SO_DETACH_REUSEPORT_BPF

[Stanislav Fomichev]

On 06/12, Martin KaFai Lau wrote:
> There is SO_ATTACH_REUSEPORT_[CE]BPF but there is no DETACH.
> This patch adds SO_DETACH_REUSEPORT_BPF sockopt.  The same
> sockopt can be used to undo both SO_ATTACH_REUSEPORT_[CE]BPF.
> 
> reseport_detach_prog() is added and it is mostly a mirror
> of the existing reuseport_attach_prog().  The differences are,
> it does not call reuseport_alloc() and returns -ENOENT when
> there is no old prog.
> 
> Cc: Craig Gallek <kraig@google.com>
> Signed-off-by: Martin KaFai Lau <kafai@fb.com>
> ---
>  arch/alpha/include/uapi/asm/socket.h  |  2 ++
>  arch/mips/include/uapi/asm/socket.h   |  2 ++
>  arch/parisc/include/uapi/asm/socket.h |  2 ++
>  arch/sparc/include/uapi/asm/socket.h  |  2 ++
>  include/net/sock_reuseport.h          |  2 ++
>  include/uapi/asm-generic/socket.h     |  2 ++
>  net/core/sock.c                       |  4 ++++
>  net/core/sock_reuseport.c             | 24 ++++++++++++++++++++++++
>  8 files changed, 40 insertions(+)
> 
> diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
> index 976e89b116e5..de6c4df61082 100644
> --- a/arch/alpha/include/uapi/asm/socket.h
> +++ b/arch/alpha/include/uapi/asm/socket.h
> @@ -122,6 +122,8 @@
>  #define SO_RCVTIMEO_NEW         66
>  #define SO_SNDTIMEO_NEW         67
>  
> +#define SO_DETACH_REUSEPORT_BPF 68
> +
>  #if !defined(__KERNEL__)
>  
>  #if __BITS_PER_LONG == 64
> diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h
> index d41765cfbc6e..d0a9ed2ca2d6 100644
> --- a/arch/mips/include/uapi/asm/socket.h
> +++ b/arch/mips/include/uapi/asm/socket.h
> @@ -133,6 +133,8 @@
>  #define SO_RCVTIMEO_NEW         66
>  #define SO_SNDTIMEO_NEW         67
>  
> +#define SO_DETACH_REUSEPORT_BPF 68
> +
>  #if !defined(__KERNEL__)
>  
>  #if __BITS_PER_LONG == 64
> diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h
> index 66c5dd245ac7..10173c32195e 100644
> --- a/arch/parisc/include/uapi/asm/socket.h
> +++ b/arch/parisc/include/uapi/asm/socket.h
> @@ -114,6 +114,8 @@
>  #define SO_RCVTIMEO_NEW         0x4040
>  #define SO_SNDTIMEO_NEW         0x4041
>  
> +#define SO_DETACH_REUSEPORT_BPF 0x4042
> +
>  #if !defined(__KERNEL__)
>  
>  #if __BITS_PER_LONG == 64
> diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h
> index 9265a9eece15..1895ac112a24 100644
> --- a/arch/sparc/include/uapi/asm/socket.h
> +++ b/arch/sparc/include/uapi/asm/socket.h
> @@ -115,6 +115,8 @@
>  #define SO_RCVTIMEO_NEW          0x0044
>  #define SO_SNDTIMEO_NEW          0x0045
>  
> +#define SO_DETACH_REUSEPORT_BPF  0x0046
> +
>  #if !defined(__KERNEL__)
>  
>  
> diff --git a/include/net/sock_reuseport.h b/include/net/sock_reuseport.h
> index 8a5f70c7cdf2..d9112de85261 100644
> --- a/include/net/sock_reuseport.h
> +++ b/include/net/sock_reuseport.h
> @@ -35,6 +35,8 @@ extern struct sock *reuseport_select_sock(struct sock *sk,
>  					  struct sk_buff *skb,
>  					  int hdr_len);
>  extern int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog);
> +extern int reuseport_detach_prog(struct sock *sk);
> +
>  int reuseport_get_id(struct sock_reuseport *reuse);
>  
>  #endif  /* _SOCK_REUSEPORT_H */
> diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h
> index 8c1391c89171..77f7c1638eb1 100644
> --- a/include/uapi/asm-generic/socket.h
> +++ b/include/uapi/asm-generic/socket.h
> @@ -117,6 +117,8 @@
>  #define SO_RCVTIMEO_NEW         66
>  #define SO_SNDTIMEO_NEW         67
>  
> +#define SO_DETACH_REUSEPORT_BPF 68
> +
>  #if !defined(__KERNEL__)
>  
>  #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 75b1c950b49f..06be30737b69 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -1045,6 +1045,10 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
>  		}
>  		break;
>  
> +	case SO_DETACH_REUSEPORT_BPF:
> +		ret = reuseport_detach_prog(sk);
> +		break;
> +
>  	case SO_DETACH_FILTER:
>  		ret = sk_detach_filter(sk);
>  		break;
> diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
> index dc4aefdf2a08..e0cb29469fa7 100644
> --- a/net/core/sock_reuseport.c
> +++ b/net/core/sock_reuseport.c
> @@ -332,3 +332,27 @@ int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog)
>  	return 0;
>  }
>  EXPORT_SYMBOL(reuseport_attach_prog);
> +
> +int reuseport_detach_prog(struct sock *sk)
> +{
> +	struct sock_reuseport *reuse;
> +	struct bpf_prog *old_prog;
> +
> +	if (!rcu_access_pointer(sk->sk_reuseport_cb))
> +		return sk->sk_reuseport ? -ENOENT : -EINVAL;
> +
> +	spin_lock_bh(&reuseport_lock);
> +	reuse = rcu_dereference_protected(sk->sk_reuseport_cb,
> +					  lockdep_is_held(&reuseport_lock));

[..]
> +	old_prog = rcu_dereference_protected(reuse->prog,
> +					     lockdep_is_held(&reuseport_lock));
> +	RCU_INIT_POINTER(reuse->prog, NULL);
Nit, optionally can do the following instead:

	struct bpf_prog *old_prog = NULL;

	...

	spin_lock_bh(&reuseport_lock);
	reuse = rcu_dereference_protected(...);
	rcu_swap_protected(reuse->prog, old_prog, lockdep_is_held(...));
	spin_unlock_bh(&reuseport_lock);

	if (!old_prog)
		....

	...

rcu_swap_protected does rcu_dereference_protected+rcu_assign_pointer,
can save you one line :-)

> +	spin_unlock_bh(&reuseport_lock);
> +
> +	if (!old_prog)
> +		return -ENOENT;
> +
> +	sk_reuseport_prog_free(old_prog);
> +	return 0;
> +}
> +EXPORT_SYMBOL(reuseport_detach_prog);
> -- 
> 2.17.1
> 

[PATCH v2 bpf-next 2/3] bpf: Sync asm-generic/socket.h to tools/

[Martin KaFai Lau]

SO_DETACH_REUSEPORT_BPF is needed for the test in the next patch.
It is defined in the socket.h.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 tools/include/uapi/asm-generic/socket.h | 147 ++++++++++++++++++++++++
 1 file changed, 147 insertions(+)
 create mode 100644 tools/include/uapi/asm-generic/socket.h

diff --git a/tools/include/uapi/asm-generic/socket.h b/tools/include/uapi/asm-generic/socket.h
new file mode 100644
index 000000000000..77f7c1638eb1
--- /dev/null
+++ b/tools/include/uapi/asm-generic/socket.h
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __ASM_GENERIC_SOCKET_H
+#define __ASM_GENERIC_SOCKET_H
+
+#include <linux/posix_types.h>
+#include <asm/sockios.h>
+
+/* For setsockopt(2) */
+#define SOL_SOCKET	1
+
+#define SO_DEBUG	1
+#define SO_REUSEADDR	2
+#define SO_TYPE		3
+#define SO_ERROR	4
+#define SO_DONTROUTE	5
+#define SO_BROADCAST	6
+#define SO_SNDBUF	7
+#define SO_RCVBUF	8
+#define SO_SNDBUFFORCE	32
+#define SO_RCVBUFFORCE	33
+#define SO_KEEPALIVE	9
+#define SO_OOBINLINE	10
+#define SO_NO_CHECK	11
+#define SO_PRIORITY	12
+#define SO_LINGER	13
+#define SO_BSDCOMPAT	14
+#define SO_REUSEPORT	15
+#ifndef SO_PASSCRED /* powerpc only differs in these */
+#define SO_PASSCRED	16
+#define SO_PEERCRED	17
+#define SO_RCVLOWAT	18
+#define SO_SNDLOWAT	19
+#define SO_RCVTIMEO_OLD	20
+#define SO_SNDTIMEO_OLD	21
+#endif
+
+/* Security levels - as per NRL IPv6 - don't actually do anything */
+#define SO_SECURITY_AUTHENTICATION		22
+#define SO_SECURITY_ENCRYPTION_TRANSPORT	23
+#define SO_SECURITY_ENCRYPTION_NETWORK		24
+
+#define SO_BINDTODEVICE	25
+
+/* Socket filtering */
+#define SO_ATTACH_FILTER	26
+#define SO_DETACH_FILTER	27
+#define SO_GET_FILTER		SO_ATTACH_FILTER
+
+#define SO_PEERNAME		28
+
+#define SO_ACCEPTCONN		30
+
+#define SO_PEERSEC		31
+#define SO_PASSSEC		34
+
+#define SO_MARK			36
+
+#define SO_PROTOCOL		38
+#define SO_DOMAIN		39
+
+#define SO_RXQ_OVFL             40
+
+#define SO_WIFI_STATUS		41
+#define SCM_WIFI_STATUS	SO_WIFI_STATUS
+#define SO_PEEK_OFF		42
+
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS		43
+
+#define SO_LOCK_FILTER		44
+
+#define SO_SELECT_ERR_QUEUE	45
+
+#define SO_BUSY_POLL		46
+
+#define SO_MAX_PACING_RATE	47
+
+#define SO_BPF_EXTENSIONS	48
+
+#define SO_INCOMING_CPU		49
+
+#define SO_ATTACH_BPF		50
+#define SO_DETACH_BPF		SO_DETACH_FILTER
+
+#define SO_ATTACH_REUSEPORT_CBPF	51
+#define SO_ATTACH_REUSEPORT_EBPF	52
+
+#define SO_CNX_ADVICE		53
+
+#define SCM_TIMESTAMPING_OPT_STATS	54
+
+#define SO_MEMINFO		55
+
+#define SO_INCOMING_NAPI_ID	56
+
+#define SO_COOKIE		57
+
+#define SCM_TIMESTAMPING_PKTINFO	58
+
+#define SO_PEERGROUPS		59
+
+#define SO_ZEROCOPY		60
+
+#define SO_TXTIME		61
+#define SCM_TXTIME		SO_TXTIME
+
+#define SO_BINDTOIFINDEX	62
+
+#define SO_TIMESTAMP_OLD        29
+#define SO_TIMESTAMPNS_OLD      35
+#define SO_TIMESTAMPING_OLD     37
+
+#define SO_TIMESTAMP_NEW        63
+#define SO_TIMESTAMPNS_NEW      64
+#define SO_TIMESTAMPING_NEW     65
+
+#define SO_RCVTIMEO_NEW         66
+#define SO_SNDTIMEO_NEW         67
+
+#define SO_DETACH_REUSEPORT_BPF 68
+
+#if !defined(__KERNEL__)
+
+#if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
+/* on 64-bit and x32, avoid the ?: operator */
+#define SO_TIMESTAMP		SO_TIMESTAMP_OLD
+#define SO_TIMESTAMPNS		SO_TIMESTAMPNS_OLD
+#define SO_TIMESTAMPING		SO_TIMESTAMPING_OLD
+
+#define SO_RCVTIMEO		SO_RCVTIMEO_OLD
+#define SO_SNDTIMEO		SO_SNDTIMEO_OLD
+#else
+#define SO_TIMESTAMP (sizeof(time_t) == sizeof(__kernel_long_t) ? SO_TIMESTAMP_OLD : SO_TIMESTAMP_NEW)
+#define SO_TIMESTAMPNS (sizeof(time_t) == sizeof(__kernel_long_t) ? SO_TIMESTAMPNS_OLD : SO_TIMESTAMPNS_NEW)
+#define SO_TIMESTAMPING (sizeof(time_t) == sizeof(__kernel_long_t) ? SO_TIMESTAMPING_OLD : SO_TIMESTAMPING_NEW)
+
+#define SO_RCVTIMEO (sizeof(time_t) == sizeof(__kernel_long_t) ? SO_RCVTIMEO_OLD : SO_RCVTIMEO_NEW)
+#define SO_SNDTIMEO (sizeof(time_t) == sizeof(__kernel_long_t) ? SO_SNDTIMEO_OLD : SO_SNDTIMEO_NEW)
+#endif
+
+#define SCM_TIMESTAMP           SO_TIMESTAMP
+#define SCM_TIMESTAMPNS         SO_TIMESTAMPNS
+#define SCM_TIMESTAMPING        SO_TIMESTAMPING
+
+#endif
+
+#endif /* __ASM_GENERIC_SOCKET_H */
-- 
2.17.1

[PATCH v2 bpf-next 3/3] bpf: Add test for SO_REUSEPORT_DETACH_BPF

[Martin KaFai Lau]

This patch adds a test for the new sockopt SO_REUSEPORT_DETACH_BPF.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 .../selftests/bpf/test_select_reuseport.c     | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/tools/testing/selftests/bpf/test_select_reuseport.c b/tools/testing/selftests/bpf/test_select_reuseport.c
index 75646d9b34aa..7566c13eb51a 100644
--- a/tools/testing/selftests/bpf/test_select_reuseport.c
+++ b/tools/testing/selftests/bpf/test_select_reuseport.c
@@ -523,6 +523,58 @@ static void test_pass_on_err(int type, sa_family_t family)
 	printf("OK\n");
 }
 
+static void test_detach_bpf(int type, sa_family_t family)
+{
+#ifdef SO_DETACH_REUSEPORT_BPF
+	__u32 nr_run_before = 0, nr_run_after = 0, tmp, i;
+	struct epoll_event ev;
+	int cli_fd, err, nev;
+	struct cmd cmd = {};
+	int optvalue = 0;
+
+	printf("%s: ", __func__);
+	err = setsockopt(sk_fds[0], SOL_SOCKET, SO_DETACH_REUSEPORT_BPF,
+			 &optvalue, sizeof(optvalue));
+	CHECK(err == -1, "setsockopt(SO_DETACH_REUSEPORT_BPF)",
+	      "err:%d errno:%d\n", err, errno);
+
+	err = setsockopt(sk_fds[1], SOL_SOCKET, SO_DETACH_REUSEPORT_BPF,
+			 &optvalue, sizeof(optvalue));
+	CHECK(err == 0 || errno != ENOENT, "setsockopt(SO_DETACH_REUSEPORT_BPF)",
+	      "err:%d errno:%d\n", err, errno);
+
+	for (i = 0; i < NR_RESULTS; i++) {
+		err = bpf_map_lookup_elem(result_map, &i, &tmp);
+		CHECK(err == -1, "lookup_elem(result_map)",
+		      "i:%u err:%d errno:%d\n", i, err, errno);
+		nr_run_before += tmp;
+	}
+
+	cli_fd = send_data(type, family, &cmd, sizeof(cmd), PASS);
+	nev = epoll_wait(epfd, &ev, 1, 5);
+	CHECK(nev <= 0, "nev <= 0",
+	      "nev:%d expected:1 type:%d family:%d data:(0, 0)\n",
+	      nev,  type, family);
+
+	for (i = 0; i < NR_RESULTS; i++) {
+		err = bpf_map_lookup_elem(result_map, &i, &tmp);
+		CHECK(err == -1, "lookup_elem(result_map)",
+		      "i:%u err:%d errno:%d\n", i, err, errno);
+		nr_run_after += tmp;
+	}
+
+	CHECK(nr_run_before != nr_run_after,
+	      "nr_run_before != nr_run_after",
+	      "nr_run_before:%u nr_run_after:%u\n",
+	      nr_run_before, nr_run_after);
+
+	printf("OK\n");
+	close(cli_fd);
+#else
+	printf("%s: SKIP\n", __func__);
+#endif
+}
+
 static void prepare_sk_fds(int type, sa_family_t family, bool inany)
 {
 	const int first = REUSEPORT_ARRAY_SIZE - 1;
@@ -664,6 +716,8 @@ static void test_all(void)
 			test_pass(type, family);
 			test_syncookie(type, family);
 			test_pass_on_err(type, family);
+			/* Must be the last test */
+			test_detach_bpf(type, family);
 
 			cleanup_per_test();
 			printf("\n");
-- 
2.17.1