From 0b040829952d84bf2a62526f0e24b624e0699447 Mon Sep 17 00:00:00 2001 From: Adrian Bunk Date: Tue, 10 Jun 2008 22:46:50 -0700 Subject: net: remove CVS keywords This patch removes CVS keywords that weren't updated for a long time from comments. Signed-off-by: Adrian Bunk Signed-off-by: David S. Miller --- include/linux/if_tun.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux/if_tun.h') diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h index 8c71fe2fb1f5..18f31b6187a3 100644 --- a/include/linux/if_tun.h +++ b/include/linux/if_tun.h @@ -11,8 +11,6 @@ * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. - * - * $Id: if_tun.h,v 1.2 2001/06/01 18:39:47 davem Exp $ */ #ifndef __IF_TUN_H -- cgit v1.2.3 From 07240fd0902c872f044f523893364a1a24c9f278 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 3 Jul 2008 03:45:32 -0700 Subject: tun: Interface to query tun/tap features. The problem with introducing checksum offload and gso to tun is they need to set dev->features to enable GSO and/or checksumming, which is supposed to be done before register_netdevice(), ie. as part of TUNSETIFF. Unfortunately, TUNSETIFF has always just ignored flags it doesn't understand, so there's no good way of detecting whether the kernel supports new IFF_ flags. This patch implements a TUNGETFEATURES ioctl which returns all the valid IFF flags. It could be extended later to include other features. Here's an example program which uses it: #include #include #include #include #include #include #include static struct { unsigned int flag; const char *name; } known_flags[] = { { IFF_TUN, "TUN" }, { IFF_TAP, "TAP" }, { IFF_NO_PI, "NO_PI" }, { IFF_ONE_QUEUE, "ONE_QUEUE" }, }; int main() { unsigned int features, i; int netfd = open("/dev/net/tun", O_RDWR); if (netfd < 0) err(1, "Opening /dev/net/tun"); if (ioctl(netfd, TUNGETFEATURES, &features) != 0) { printf("Kernel does not support TUNGETFEATURES, guessing\n"); features = (IFF_TUN|IFF_TAP|IFF_NO_PI|IFF_ONE_QUEUE); } printf("Available features are: "); for (i = 0; i < sizeof(known_flags)/sizeof(known_flags[0]); i++) { if (features & known_flags[i].flag) { features &= ~known_flags[i].flag; printf("%s ", known_flags[i].name); } } if (features) printf("(UNKNOWN %#x)", features); printf("\n"); return 0; } Signed-off-by: Rusty Russell Acked-by: Max Krasnyansky Signed-off-by: David S. Miller --- include/linux/if_tun.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/if_tun.h') diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h index 18f31b6187a3..94f76a112303 100644 --- a/include/linux/if_tun.h +++ b/include/linux/if_tun.h @@ -40,6 +40,7 @@ #define TUNSETOWNER _IOW('T', 204, int) #define TUNSETLINK _IOW('T', 205, int) #define TUNSETGROUP _IOW('T', 206, int) +#define TUNGETFEATURES _IOR('T', 207, unsigned int) /* TUNSETIFF ifr flags */ #define IFF_TUN 0x0001 -- cgit v1.2.3 From 5228ddc98fa49b3cedab4024e269d62410a0d806 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 3 Jul 2008 03:46:16 -0700 Subject: tun: TUNSETFEATURES to set gso features. ethtool is useful for setting (some) device fields, but it's root-only. Finer feature control is available through a tun-specific ioctl. (Includes Mark McLoughlin 's fix to hold rtnl sem). Signed-off-by: Rusty Russell Acked-by: Max Krasnyansky Signed-off-by: David S. Miller --- include/linux/if_tun.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/linux/if_tun.h') diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h index 94f76a112303..3f0a0995d449 100644 --- a/include/linux/if_tun.h +++ b/include/linux/if_tun.h @@ -41,6 +41,7 @@ #define TUNSETLINK _IOW('T', 205, int) #define TUNSETGROUP _IOW('T', 206, int) #define TUNGETFEATURES _IOR('T', 207, unsigned int) +#define TUNSETOFFLOAD _IOW('T', 208, unsigned int) /* TUNSETIFF ifr flags */ #define IFF_TUN 0x0001 @@ -48,6 +49,12 @@ #define IFF_NO_PI 0x1000 #define IFF_ONE_QUEUE 0x2000 +/* Features for GSO (TUNSETOFFLOAD). */ +#define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */ +#define TUN_F_TSO4 0x02 /* I can handle TSO for IPv4 packets */ +#define TUN_F_TSO6 0x04 /* I can handle TSO for IPv6 packets */ +#define TUN_F_TSO_ECN 0x08 /* I can handle TSO with ECN bits. */ + struct tun_pi { unsigned short flags; __be16 proto; -- cgit v1.2.3 From f43798c27684ab925adde7d8acc34c78c6e50df8 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 3 Jul 2008 03:48:02 -0700 Subject: tun: Allow GSO using virtio_net_hdr Add a IFF_VNET_HDR flag. This uses the same ABI as virtio_net (ie. prepending struct virtio_net_hdr to packets) to indicate GSO and checksum information. Signed-off-by: Rusty Russell Acked-by: Max Krasnyansky Signed-off-by: David S. Miller --- include/linux/if_tun.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/if_tun.h') diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h index 3f0a0995d449..563fae542da6 100644 --- a/include/linux/if_tun.h +++ b/include/linux/if_tun.h @@ -31,6 +31,7 @@ #define TUN_NO_PI 0x0040 #define TUN_ONE_QUEUE 0x0080 #define TUN_PERSIST 0x0100 +#define TUN_VNET_HDR 0x0200 /* Ioctl defines */ #define TUNSETNOCSUM _IOW('T', 200, int) @@ -48,6 +49,7 @@ #define IFF_TAP 0x0002 #define IFF_NO_PI 0x1000 #define IFF_ONE_QUEUE 0x2000 +#define IFF_VNET_HDR 0x4000 /* Features for GSO (TUNSETOFFLOAD). */ #define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */ -- cgit v1.2.3 From f271b2cc78f09c93ccd00a2056d3237134bf994c Mon Sep 17 00:00:00 2001 From: Max Krasnyansky Date: Mon, 14 Jul 2008 22:18:19 -0700 Subject: tun: Fix/rewrite packet filtering logic Please see the following thread to get some context on this http://marc.info/?l=linux-netdev&m=121564433018903&w=2 Basically the issue is that current multi-cast filtering stuff in the TUN/TAP driver is seriously broken. Original patch went in without proper review and ACK. It was broken and confusing to start with and subsequent patches broke it completely. To give you an idea of what's broken here are some of the issues: - Very confusing comments throughout the code that imply that the character device is a network interface in its own right, and that packets are passed between the two nics. Which is completely wrong. - Wrong set of ioctls is used for setting up filters. They look like shortcuts for manipulating state of the tun/tap network interface but in reality manipulate the state of the TX filter. - ioctls that were originally used for setting address of the the TX filter got "fixed" and now set the address of the network interface itself. Which made filter totaly useless. - Filtering is done too late. Instead of filtering early on, to avoid unnecessary wakeups, filtering is done in the read() call. The list goes on and on :) So the patch cleans all that up. It introduces simple and clean interface for setting up TX filters (TUNSETTXFILTER + tun_filter spec) and does filtering before enqueuing the packets. TX filtering is useful in the scenarios where TAP is part of a bridge, in which case it gets all broadcast, multicast and potentially other packets when the bridge is learning. So for example Ethernet tunnelling app may want to setup TX filters to avoid tunnelling multicast traffic. QEMU and other hypervisors can push RX filtering that is currently done in the guest into the host context therefore saving wakeups and unnecessary data transfer. Signed-off-by: Max Krasnyansky Signed-off-by: David S. Miller --- include/linux/if_tun.h | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) (limited to 'include/linux/if_tun.h') diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h index 563fae542da6..4c6307ad9fdb 100644 --- a/include/linux/if_tun.h +++ b/include/linux/if_tun.h @@ -17,6 +17,7 @@ #define __IF_TUN_H #include +#include /* Read queue size */ #define TUN_READQ_SIZE 500 @@ -42,7 +43,8 @@ #define TUNSETLINK _IOW('T', 205, int) #define TUNSETGROUP _IOW('T', 206, int) #define TUNGETFEATURES _IOR('T', 207, unsigned int) -#define TUNSETOFFLOAD _IOW('T', 208, unsigned int) +#define TUNSETOFFLOAD _IOW('T', 208, unsigned int) +#define TUNSETTXFILTER _IOW('T', 209, unsigned int) /* TUNSETIFF ifr flags */ #define IFF_TUN 0x0001 @@ -57,10 +59,26 @@ #define TUN_F_TSO6 0x04 /* I can handle TSO for IPv6 packets */ #define TUN_F_TSO_ECN 0x08 /* I can handle TSO with ECN bits. */ +/* Protocol info prepended to the packets (when IFF_NO_PI is not set) */ +#define TUN_PKT_STRIP 0x0001 struct tun_pi { - unsigned short flags; + __u16 flags; __be16 proto; }; -#define TUN_PKT_STRIP 0x0001 + +/* + * Filter spec (used for SETXXFILTER ioctls) + * This stuff is applicable only to the TAP (Ethernet) devices. + * If the count is zero the filter is disabled and the driver accepts + * all packets (promisc mode). + * If the filter is enabled in order to accept broadcast packets + * broadcast addr must be explicitly included in the addr list. + */ +#define TUN_FLT_ALLMULTI 0x0001 /* Accept all multicast packets */ +struct tun_filter { + __u16 flags; /* TUN_FLT_ flags see above */ + __u16 count; /* Number of addresses */ + __u8 addr[0][ETH_ALEN]; +}; #endif /* __IF_TUN_H */ -- cgit v1.2.3