d9d52b5178
virtio added mergeable buffers mode where 2 bytes of extra info is put after vnet header but before actual data (tun does not need this data). In hindsight, it would have been better to add the new info *before* the packet: as it is, users need a lot of tricky code to skip the extra 2 bytes in the middle of the iovec, and in fact applications seem to get it wrong, and only work with specific iovec layout. The fact we might need to split iovec also means we might in theory overflow iovec max size. This patch adds a simpler way for applications to handle this, and future proofs the interface against further extensions, by making the size of the virtio net header configurable from userspace. As a result, tun driver will simply skip the extra 2 bytes on both input and output. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David S. Miller <davem@davemloft.net>
109 lines
3.4 KiB
C
109 lines
3.4 KiB
C
/*
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* Universal TUN/TAP device driver.
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* Copyright (C) 1999-2000 Maxim Krasnyansky <max_mk@yahoo.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef __IF_TUN_H
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#define __IF_TUN_H
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#include <linux/types.h>
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#include <linux/if_ether.h>
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#include <linux/filter.h>
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/* Read queue size */
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#define TUN_READQ_SIZE 500
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/* TUN device flags */
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#define TUN_TUN_DEV 0x0001
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#define TUN_TAP_DEV 0x0002
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#define TUN_TYPE_MASK 0x000f
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#define TUN_FASYNC 0x0010
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#define TUN_NOCHECKSUM 0x0020
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#define TUN_NO_PI 0x0040
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#define TUN_ONE_QUEUE 0x0080
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#define TUN_PERSIST 0x0100
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#define TUN_VNET_HDR 0x0200
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/* Ioctl defines */
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#define TUNSETNOCSUM _IOW('T', 200, int)
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#define TUNSETDEBUG _IOW('T', 201, int)
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#define TUNSETIFF _IOW('T', 202, int)
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#define TUNSETPERSIST _IOW('T', 203, int)
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#define TUNSETOWNER _IOW('T', 204, int)
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#define TUNSETLINK _IOW('T', 205, int)
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#define TUNSETGROUP _IOW('T', 206, int)
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#define TUNGETFEATURES _IOR('T', 207, unsigned int)
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#define TUNSETOFFLOAD _IOW('T', 208, unsigned int)
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#define TUNSETTXFILTER _IOW('T', 209, unsigned int)
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#define TUNGETIFF _IOR('T', 210, unsigned int)
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#define TUNGETSNDBUF _IOR('T', 211, int)
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#define TUNSETSNDBUF _IOW('T', 212, int)
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#define TUNATTACHFILTER _IOW('T', 213, struct sock_fprog)
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#define TUNDETACHFILTER _IOW('T', 214, struct sock_fprog)
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#define TUNGETVNETHDRSZ _IOR('T', 215, int)
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#define TUNSETVNETHDRSZ _IOW('T', 216, int)
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/* TUNSETIFF ifr flags */
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#define IFF_TUN 0x0001
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#define IFF_TAP 0x0002
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#define IFF_NO_PI 0x1000
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#define IFF_ONE_QUEUE 0x2000
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#define IFF_VNET_HDR 0x4000
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#define IFF_TUN_EXCL 0x8000
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/* Features for GSO (TUNSETOFFLOAD). */
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#define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */
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#define TUN_F_TSO4 0x02 /* I can handle TSO for IPv4 packets */
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#define TUN_F_TSO6 0x04 /* I can handle TSO for IPv6 packets */
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#define TUN_F_TSO_ECN 0x08 /* I can handle TSO with ECN bits. */
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#define TUN_F_UFO 0x10 /* I can handle UFO packets */
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/* Protocol info prepended to the packets (when IFF_NO_PI is not set) */
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#define TUN_PKT_STRIP 0x0001
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struct tun_pi {
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__u16 flags;
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__be16 proto;
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};
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/*
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* Filter spec (used for SETXXFILTER ioctls)
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* This stuff is applicable only to the TAP (Ethernet) devices.
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* If the count is zero the filter is disabled and the driver accepts
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* all packets (promisc mode).
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* If the filter is enabled in order to accept broadcast packets
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* broadcast addr must be explicitly included in the addr list.
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*/
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#define TUN_FLT_ALLMULTI 0x0001 /* Accept all multicast packets */
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struct tun_filter {
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__u16 flags; /* TUN_FLT_ flags see above */
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__u16 count; /* Number of addresses */
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__u8 addr[0][ETH_ALEN];
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};
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#ifdef __KERNEL__
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#if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE)
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struct socket *tun_get_socket(struct file *);
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#else
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#include <linux/err.h>
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#include <linux/errno.h>
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struct file;
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struct socket;
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static inline struct socket *tun_get_socket(struct file *f)
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{
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return ERR_PTR(-EINVAL);
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}
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#endif /* CONFIG_TUN */
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#endif /* __KERNEL__ */
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#endif /* __IF_TUN_H */
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