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@xxxxxxxxxx>
Signed-off-by: Martin KaFai Lau <kafai@xxxxxx>
---
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..8029b681fc7c 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 0x0047
+
#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..9408f9264d05 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;
+
+ old_prog = NULL;
+ spin_lock_bh(&reuseport_lock);
+ reuse = rcu_dereference_protected(sk->sk_reuseport_cb,
+ lockdep_is_held(&reuseport_lock));
+ rcu_swap_protected(reuse->prog, old_prog,
+ lockdep_is_held(&reuseport_lock));
+ 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
