Commit 4d748f99 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
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net: Add sk_setsockopt() to take the sk ptr instead of the sock ptr 



A latter patch refactors bpf_setsockopt(SOL_SOCKET) with the
sock_setsockopt() to avoid code duplication and code
drift between the two duplicates.

The current sock_setsockopt() 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_setsockopt() 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_setsockopt(sk->sk_socket)
or else it will pass a NULL ptr.

This patch moves all sock_setsockopt implementation to the newly
added sk_setsockopt().  The new sk_setsockopt() takes a sk ptr
and immediately gets the sock ptr by 'sock = sk->sk_socket'

The existing sock_setsockopt(sock) is changed to call
sk_setsockopt(sock->sk).  All existing callers have both sock->sk
and sk->sk_socket pointer.

The latter patch will make bpf_setsockopt(SOL_SOCKET) call
sk_setsockopt(sk) directly.  The bpf_setsockopt(SOL_SOCKET) does
not use the optnames that require sk->sk_socket, so it will
be safe.

Reviewed-by: default avatarStanislav Fomichev <sdf@google.com>
Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061711.4175048-1-kafai@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent fb8d784b

net/core/sock.c

+10 −3
Original line number Diff line number Diff line
@@ -1041,12 +1041,12 @@ static int sock_reserve_memory(struct sock *sk, int bytes) 
 *	at the socket level. Everything here is generic.

 */



int sock_setsockopt(struct socket *sock, int level, int optname,

static int sk_setsockopt(struct sock *sk, int level, int optname,

			 sockptr_t optval, unsigned int optlen)

{

	struct so_timestamping timestamping;

	struct socket *sock = sk->sk_socket;

	struct sock_txtime sk_txtime;

	struct sock *sk = sock->sk;

	int val;

	int valbool;

	struct linger ling;
@@ -1499,6 +1499,13 @@ int sock_setsockopt(struct socket *sock, int level, int optname, 
	release_sock(sk);

	return ret;

}



int sock_setsockopt(struct socket *sock, int level, int optname,

		    sockptr_t optval, unsigned int optlen)

{

	return sk_setsockopt(sock->sk, level, optname,

			     optval, optlen);

}

EXPORT_SYMBOL(sock_setsockopt);



static const struct cred *sk_get_peer_cred(struct sock *sk)