From: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
A latter patch refactors bpf_getsockopt(SOL_SOCKET) with the
sock_getsockopt() to avoid code duplication and code
drift between the two duplicates.
The current sock_getsockopt() takes sock ptr as the argument.
The very first thing of this function is to get back the sk ptr
by 'sk = sock->sk'.
bpf_getsockopt() could be called when the sk does not have
the sock ptr created. Meaning sk->sk_socket is NULL. For example,
when a passive tcp connection has just been established but has yet
been accept()-ed. Thus, it cannot use the sock_getsockopt(sk->sk_socket)
or else it will pass a NULL ptr.
This patch moves all sock_getsockopt implementation to the newly
added sk_getsockopt(). The new sk_getsockopt() takes a sk ptr
and immediately gets the sock ptr by 'sock = sk->sk_socket'
The existing sock_getsockopt(sock) is changed to call
sk_getsockopt(sock->sk). All existing callers have both sock->sk
and sk->sk_socket pointer.
The latter patch will make bpf_getsockopt(SOL_SOCKET) call
sk_getsockopt(sk) directly. The bpf_getsockopt(SOL_SOCKET) does
not use the optnames that require sk->sk_socket, so it will
be safe.
Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
---
net/core/sock.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/net/core/sock.c b/net/core/sock.c
index 2a6f84702eb9..21bc4bf6b485 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1580,10 +1580,10 @@ static int groups_to_user(gid_t __user *dst, const struct group_info *src)
return 0;
}
-int sock_getsockopt(struct socket *sock, int level, int optname,
- char __user *optval, int __user *optlen)
+static int sk_getsockopt(struct sock *sk, int level, int optname,
+ char __user *optval, int __user *optlen)
{
- struct sock *sk = sock->sk;
+ struct socket *sock = sk->sk_socket;
union {
int val;
@@ -1947,6 +1947,12 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
return 0;
}
+int sock_getsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ return sk_getsockopt(sock->sk, level, optname, optval, optlen);
+}
+
/*
* Initialize an sk_lock.
*
--
2.30.2
