From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id BA3CD6B004D for ; Tue, 3 Nov 2009 07:12:56 -0500 (EST) From: Arnd Bergmann Subject: Re: [PATCHv6 1/3] tun: export underlying socket Date: Tue, 3 Nov 2009 13:12:33 +0100 References: <20091102222612.GB15184@redhat.com> In-Reply-To: <20091102222612.GB15184@redhat.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200911031312.33580.arnd@arndb.de> Sender: owner-linux-mm@kvack.org To: virtualization@lists.linux-foundation.org Cc: "Michael S. Tsirkin" , netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@elte.hu, linux-mm@kvack.org, akpm@linux-foundation.org, hpa@zytor.com, gregory.haskins@gmail.com, Rusty Russell , s.hetze@linux-ag.com List-ID: On Monday 02 November 2009, Michael S. Tsirkin wrote: > Tun device looks similar to a packet socket > in that both pass complete frames from/to userspace. > > This patch fills in enough fields in the socket underlying tun driver > to support sendmsg/recvmsg operations, and message flags > MSG_TRUNC and MSG_DONTWAIT, and exports access to this socket > to modules. Regular read/write behaviour is unchanged. > > This way, code using raw sockets to inject packets > into a physical device, can support injecting > packets into host network stack almost without modification. > > First user of this interface will be vhost virtualization > accelerator. You mentioned before that you wanted to export the socket using some ioctl function returning an open file descriptor, which seemed to be a cleaner approach than this one. What was your reason for changing? > index 3f5fd52..404abe0 100644 > --- a/include/linux/if_tun.h > +++ b/include/linux/if_tun.h > @@ -86,4 +86,18 @@ struct tun_filter { > __u8 addr[0][ETH_ALEN]; > }; > > +#ifdef __KERNEL__ > +#if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE) > +struct socket *tun_get_socket(struct file *); > +#else > +#include > +#include > +struct file; > +struct socket; > +static inline struct socket *tun_get_socket(struct file *f) > +{ > + return ERR_PTR(-EINVAL); > +} > +#endif /* CONFIG_TUN */ > +#endif /* __KERNEL__ */ > #endif /* __IF_TUN_H */ Is this a leftover from testing? Exporting the function for !__KERNEL__ seems pointless. Arnd <>< -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org