[PATCH bpf-next] bpf: support SO_DEBUG in bpf_setsockopt()

[Yafang Shao <laoar.shao@gmail.com>]

Then we can enable/disable socket debugging without modifying user code.
That is more convenient for debugging.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 include/net/sock.h | 8 ++++++++
 net/core/filter.c  | 3 +++
 net/core/sock.c    | 8 --------
 3 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 2b229f7..8decee9 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1935,6 +1935,14 @@ static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
 	}
 }
 
+static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
+{
+	if (valbool)
+		sock_set_flag(sk, bit);
+	else
+		sock_reset_flag(sk, bit);
+}
+
 bool sk_mc_loop(struct sock *sk);
 
 static inline bool sk_can_gso(const struct sock *sk)
diff --git a/net/core/filter.c b/net/core/filter.c
index 3a49f68..ce5da57 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4111,6 +4111,9 @@ static unsigned long bpf_xdp_copy(void *dst_buff, const void *src_buff,
 
 		/* Only some socketops are supported */
 		switch (optname) {
+		case SO_DEBUG:
+			sock_valbool_flag(sk, SOCK_DBG, val);
+			break;
 		case SO_RCVBUF:
 			sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
 			sk->sk_rcvbuf = max_t(int, val * 2, SOCK_MIN_RCVBUF);
diff --git a/net/core/sock.c b/net/core/sock.c
index 900e8a9..5ef6daa 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -638,14 +638,6 @@ static int sock_getbindtodevice(struct sock *sk, char __user *optval,
 	return ret;
 }
 
-static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
-{
-	if (valbool)
-		sock_set_flag(sk, bit);
-	else
-		sock_reset_flag(sk, bit);
-}
-
 bool sk_mc_loop(struct sock *sk)
 {
 	if (dev_recursion_level())
-- 
1.8.3.1