Files
linux/include/linux
Rusty Russell 07240fd090 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 <linux/if_tun.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <err.h>
#include <stdio.h>

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 <rusty@rustcorp.com.au>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-03 03:45:32 -07:00
..
2008-01-28 14:54:13 -08:00
2008-06-11 21:00:38 -07:00
2007-12-26 19:36:35 -08:00
2008-02-05 03:20:13 -08:00
2008-02-06 10:41:02 -08:00
2008-04-29 08:06:00 -07:00
2008-01-28 15:00:14 -08:00
2008-03-04 13:41:23 +01:00
2008-04-28 06:28:37 -04:00
2008-04-29 08:11:16 -07:00
2008-06-06 11:29:10 -07:00
2008-04-29 12:36:54 -07:00
2008-05-29 01:38:46 -07:00
2008-04-22 15:16:32 -05:00
2008-04-29 08:06:01 -07:00
2008-01-28 14:54:10 -08:00
2008-02-03 17:45:46 +02:00
2008-05-01 08:03:59 -07:00
2008-01-28 23:21:18 +01:00
2008-04-30 08:29:52 -07:00
2008-02-03 17:45:46 +02:00
2008-02-03 15:42:53 +02:00
2008-03-04 14:47:06 -08:00
2008-04-21 11:22:28 -05:00
2008-04-25 13:26:55 +01:00
2008-04-25 13:26:55 +01:00
2008-02-08 02:09:56 +00:00
2008-04-25 13:26:55 +01:00
2008-04-21 22:38:45 +00:00
2008-02-08 09:22:24 -08:00
2008-04-28 08:58:30 -07:00
2008-04-19 19:19:54 +02:00
2008-02-07 08:42:30 -08:00
2008-01-28 23:21:18 +01:00
2008-05-07 09:48:23 +02:00
2008-04-28 08:58:35 -07:00
2008-05-16 17:22:26 -04:00
2008-05-01 13:08:16 -04:00
2008-06-06 11:29:11 -07:00
2008-05-13 08:02:26 -07:00
2008-05-24 09:56:13 -07:00
2008-05-20 16:44:43 +02:00
2008-05-20 16:44:43 +02:00
2008-04-22 11:34:59 +02:00
2008-02-05 09:44:19 -08:00
2008-04-04 18:36:49 +02:00
2008-04-29 23:11:38 +02:00
2008-05-18 20:49:41 +02:00
2008-04-29 08:06:25 -07:00
2008-06-11 21:00:38 -07:00
2008-01-28 15:07:58 -08:00
2008-06-11 21:00:38 -07:00
2008-01-28 14:55:09 -08:00
2008-07-03 17:51:57 +09:00
2008-03-17 22:48:46 -07:00
2008-04-29 08:06:03 -07:00
2008-04-29 08:06:02 -07:00
2008-05-05 16:47:14 +10:00
2008-06-11 19:13:46 -04:00
2008-06-11 21:00:38 -07:00
2008-04-29 08:06:15 -07:00
2008-04-19 19:10:28 -07:00
2008-05-01 08:03:58 -07:00
2008-05-14 19:11:14 -07:00
2008-04-19 19:44:57 +02:00
2008-06-06 21:25:51 +03:00
2008-01-25 21:08:34 +01:00
2008-02-03 17:45:46 +02:00
2008-02-06 10:41:01 -08:00
2008-02-26 14:03:47 +09:00
2008-04-29 08:06:01 -07:00
2008-06-12 18:05:41 -07:00
2008-05-24 09:56:09 -07:00
2008-05-26 16:08:40 +02:00
2008-06-06 11:29:12 -07:00
2008-02-08 09:22:31 -08:00
2008-02-14 21:13:33 -08:00
2008-04-28 08:58:29 -07:00
2008-04-19 16:54:56 -04:00
2008-04-19 16:55:29 -04:00
2008-02-14 21:13:33 -08:00
2008-06-23 20:33:01 -07:00
2008-04-20 21:47:03 -07:00
2008-04-20 21:47:03 -07:00
2008-04-29 08:06:02 -07:00
2008-02-07 23:11:56 -08:00
2008-04-29 08:06:02 -07:00
2008-05-06 12:01:41 -04:00
2008-03-17 22:46:46 -07:00
2008-06-11 21:00:38 -07:00
2008-06-11 21:00:38 -07:00
2008-02-08 09:22:31 -08:00
2008-02-05 09:44:22 -08:00
2008-01-30 13:31:47 +01:00
2008-04-30 08:29:51 -07:00
2008-04-29 08:05:59 -07:00
2008-04-17 10:43:01 -04:00
2008-04-25 00:25:08 +02:00
2008-02-07 08:42:34 -08:00
2008-04-28 08:58:32 -07:00
2008-04-15 13:26:52 -04:00
2008-02-07 08:42:30 -08:00
2008-06-06 11:29:14 -07:00
2008-01-25 21:08:33 +01:00
2008-01-31 19:28:30 -08:00
2008-01-24 00:47:27 -05:00
2008-01-30 13:31:20 +01:00
2008-01-30 13:31:20 +01:00
2008-01-25 21:08:34 +01:00
2008-02-07 08:42:34 -08:00
2008-04-28 08:58:20 -07:00
2008-04-28 08:58:29 -07:00
2008-04-19 19:44:59 +02:00
2008-05-04 17:07:03 -07:00
2008-04-29 02:48:01 -04:00
2008-02-01 17:45:14 +01:00
2008-06-12 10:48:00 +02:00
2008-05-01 08:03:59 -07:00
2008-05-29 14:46:30 +02:00
2008-04-17 20:05:36 +02:00
2008-01-24 20:40:26 -08:00
2008-04-24 21:16:57 -07:00
2008-05-09 07:45:18 -07:00
2007-12-26 19:36:35 -08:00
2008-02-04 23:50:13 +11:00
2008-04-28 08:58:21 -07:00
2008-02-06 10:41:03 -08:00