Re: [PATCHv6 1/3] tun: export underlying socket
From: Arnd Bergmann <arnd@arndb.de>
Date: 2009-11-03 12:13:22
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kvm, linux-mm, lkml
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?
quoted hunk ↗ jump to hunk
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 <linux/err.h> +#include <linux/errno.h> +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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>