On Mon, Apr 26, 2021 at 04:49 AM CEST, Cong Wang wrote:
> From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
>
> unix_proto is special, it is very different from INET proto,
> which even does not have a ->close(). We have to add a dummy
> one to satisfy sockmap.
>
> And now we can implement unix_bpf_update_proto() to update
> sk_prot.
>
> Cc: John Fastabend <john.fastabend@xxxxxxxxx>
> Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> Cc: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
> Cc: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
> Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
> ---
[...]
> diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c
> new file mode 100644
> index 000000000000..b1582a659427
> --- /dev/null
> +++ b/net/unix/unix_bpf.c
> @@ -0,0 +1,47 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2021 Cong Wang <cong.wang@xxxxxxxxxxxxx> */
> +
> +#include <linux/skmsg.h>
> +#include <linux/bpf.h>
> +#include <net/sock.h>
> +#include <net/af_unix.h>
> +
> +static struct proto *unix_prot_saved __read_mostly;
> +static DEFINE_SPINLOCK(unix_prot_lock);
> +static struct proto unix_bpf_prot;
> +
> +static void unix_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
> +{
> + *prot = *base;
> + prot->close = sock_map_close;
> +}
I think we also need unhash so that socket gets removed from sockmap
on disconnect, that is connect(fd, {sa_family=AF_UNSPEC, ...}, ...).
