From 99f3a064bc2e4bd5fe50218646c5be342f2ad18c Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Thu, 13 Jun 2019 15:00:01 -0700 Subject: [PATCH] bpf: net: Add SO_DETACH_REUSEPORT_BPF 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 Signed-off-by: Martin KaFai Lau Reviewed-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- 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 @@ set_rcvbuf: } 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); -- 2.11.0