From: Martin KaFai Lau
> Sent: 27 July 2022 07:09
>
> 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
> a userspace owner. Meaning sk->sk_socket is NULL. For example,
> when a passive tcp connection has just been established. Thus,
> it cannot use the sock_setsockopt(sk->sk_socket) or else it will
> pass a NULL sock ptr.
I'm intrigued, I've some code that uses sock_create_kern() to create
sockets without a userspace owner - I'd have though bpf is doing
much the same.
I end up doing:
if (level == SOL_SOCKET)
err = sock_setsockopt(sock, level, optname, koptval, optlen);
else
err = sock->ops->setsockopt(sock, level, optname, koptval,
optlen);
to set options.
(This code used to use kern_setsockopt() - but that got removed.)
I'd have though bpf would need similar code??
David
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