netdev - Re: [PATCH bpf-next v4 1/7] bpf: add bpf_skc_to_mptcp_sock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CA+WQbwvHidwt0ua=g67CJfmjtCow8SCvZp4Sz=2AZa+ocDxnpg@mail.gmail.com>
Date:   Tue, 17 May 2022 13:26:27 +0800
From:   Geliang Tang <geliangtang@...il.com>
To:     Martin KaFai Lau <kafai@...com>
Cc:     Geliang Tang <geliang.tang@...e.com>,
        Mat Martineau <mathew.j.martineau@...ux.intel.com>,
        Networking <netdev@...r.kernel.org>, bpf <bpf@...r.kernel.org>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        MPTCP Upstream <mptcp@...ts.linux.dev>,
        Nicolas Rybowski <nicolas.rybowski@...sares.net>,
        Matthieu Baerts <matthieu.baerts@...sares.net>
Subject: Re: [PATCH bpf-next v4 1/7] bpf: add bpf_skc_to_mptcp_sock_proto

Martin KaFai Lau <kafai@...com> 于2022年5月17日周二 09:07写道：
>
> On Fri, May 13, 2022 at 03:48:21PM -0700, Mat Martineau wrote:
> [ ... ]
>
> > diff --git a/include/net/mptcp.h b/include/net/mptcp.h
> > index 8b1afd6f5cc4..2ba09de955c7 100644
> > --- a/include/net/mptcp.h
> > +++ b/include/net/mptcp.h
> > @@ -284,4 +284,10 @@ static inline int mptcpv6_init(void) { return 0; }
> >  static inline void mptcpv6_handle_mapped(struct sock *sk, bool mapped) { }
> >  #endif
> >
> > +#if defined(CONFIG_MPTCP) && defined(CONFIG_BPF_SYSCALL)
> > +struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk);
> Can this be inline ?

This function can't be inline since it uses struct mptcp_subflow_context.

mptcp_subflow_context is defined in net/mptcp/protocol.h, and we don't
want to export it to user space in net/mptcp/protocol.h.

>
> > +#else
> > +static inline struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk) { return NULL; }
> > +#endif
> > +
> >  #endif /* __NET_MPTCP_H */
>
> [ ... ]
>
> > diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
> > new file mode 100644
> > index 000000000000..535602ba2582
> > --- /dev/null
> > +++ b/net/mptcp/bpf.c
> > @@ -0,0 +1,22 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Multipath TCP
> > + *
> > + * Copyright (c) 2020, Tessares SA.
> > + * Copyright (c) 2022, SUSE.
> > + *
> > + * Author: Nicolas Rybowski <nicolas.rybowski@...sares.net>
> > + */
> > +
> > +#define pr_fmt(fmt) "MPTCP: " fmt
> > +
> > +#include <linux/bpf.h>
> > +#include "protocol.h"
> > +
> > +struct mptcp_sock *bpf_mptcp_sock_from_subflow(struct sock *sk)
> > +{
> > +     if (sk && sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP && sk_is_mptcp(sk))
> > +             return mptcp_sk(mptcp_subflow_ctx(sk)->conn);
> > +
> > +     return NULL;
> > +}
> > +EXPORT_SYMBOL(bpf_mptcp_sock_from_subflow);
> Is EXPORT_SYMBOL needed ?

Will drop in v5.

Thanks,
-Geliang

>