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Message-ID: <7dd8ed05495a8f9e1dad7f27e5186f62c8c0b730.camel@redhat.com>
Subject: Re: [PATCHv5] PPPoL2TP: Add more code snippets
From: Paolo Abeni <pabeni@redhat.com>
To: Samuel Thibault <samuel.thibault@ens-lyon.org>, James Chapman
	 <jchapman@katalix.com>, tparkin@katalix.com, edumazet@google.com, 
	gnault@redhat.com
Cc: davem@davemloft.net, kuba@kernel.org, corbet@lwn.net,
 netdev@vger.kernel.org,  linux-doc@vger.kernel.org,
 linux-kernel@vger.kernel.org
Date: Thu, 15 Feb 2024 13:49:42 +0100
In-Reply-To: <20240214012102.dsdgcdgvwgfabzdi@begin>
References: <20240214012102.dsdgcdgvwgfabzdi@begin>
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On Wed, 2024-02-14 at 02:21 +0100, Samuel Thibault wrote:
[...]
> +  - Bridging L2TP sessions which have PPP pseudowire types (this is also=
 called
> +    L2TP tunnel switching or L2TP multihop) is supported by bridging the=
 PPP
> +    channels of the two L2TP sessions to be bridged::
> +
> +        /* Input: the session PPPoX data sockets `session_fd1` and `sess=
ion_fd2`
> +         * which were created as described further above.
> +         */
> +
> +        int ppp_chan_fd;
> +        int chindx1;
> +        int chindx2;
> +        int ret;
> +
> +        ret =3D ioctl(session_fd1, PPPIOCGCHAN, &chindx1);
> +        if (ret < 0)
> +                return -errno;
> +
> +        ret =3D ioctl(session_fd2, PPPIOCGCHAN, &chindx2);
> +        if (ret < 0)
> +                return -errno;
> +
> +        ppp_chan_fd =3D open("/dev/ppp", O_RDWR);
> +        if (ppp_chan_fd < 0)
> +                return -errno;
> +
> +        ret =3D ioctl(ppp_chan_fd, PPPIOCATTCHAN, &chindx1);
> +        if (ret < 0) {
> +                close(ppp_chan_fd);
> +                return -errno;
> +        }
> +
> +        ret =3D ioctl(ppp_chan_fd, PPPIOCBRIDGECHAN, &chindx2);
> +        close(ppp_chan_fd);
> +        if (ret < 0)
> +                return -errno;
> +
>          return 0;
> =20
> +It can be noted that when bridging PPP channels, the PPP session is not =
locally terminated, and no local PPP interface is created.  PPP frames arri=
ving on one channel are directly passed to the other channel, and vice vers=
a.

You need to format the above sentence to fit a more reasonable line
length.

Thanks!

Paolo