[PATCH net-next V2 2/3] tun: introduce ioctls to set and get steering policies

From: Jason Wang
Date: Tue Oct 31 2017 - 06:32:58 EST


This patch introduces new ioctl for change packet steering policy for
tun. Only automatic flow steering is supported, more policies will
come.

Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/net/tun.c | 35 ++++++++++++++++++++++++++++++++++-
include/uapi/linux/if_tun.h | 7 +++++++
2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index bff6259..ab109ff 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -122,7 +122,8 @@ do { \
#define TUN_VNET_BE 0x40000000

#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
- IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS)
+ IFF_MULTI_QUEUE | IFF_NAPI | IFF_NAPI_FRAGS | \
+ IFF_MULTI_STEERING)

#define GOODCOPY_LEN 128

@@ -2516,6 +2517,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
unsigned int ifindex;
int le;
int ret;
+ unsigned int steering;

if (cmd == TUNSETIFF || cmd == TUNSETQUEUE || _IOC_TYPE(cmd) == SOCK_IOC_TYPE) {
if (copy_from_user(&ifr, argp, ifreq_len))
@@ -2774,6 +2776,37 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
ret = 0;
break;

+ case TUNSETSTEERING:
+ ret = -EFAULT;
+ if (copy_from_user(&steering, argp, sizeof(steering)))
+ break;
+ ret = 0;
+ switch (steering) {
+ case TUN_STEERING_AUTOMQ:
+ tun->steering_ops = &tun_automq_ops;
+ break;
+ default:
+ ret = -EFAULT;
+ }
+ break;
+
+ case TUNGETSTEERING:
+ ret = 0;
+ if (tun->steering_ops == &tun_automq_ops)
+ steering = TUN_STEERING_AUTOMQ;
+ else
+ BUG();
+ if (copy_to_user(argp, &steering, sizeof(steering)))
+ ret = -EFAULT;
+ break;
+
+ case TUNGETSTEERINGFEATURES:
+ ret = 0;
+ steering = TUN_STEERING_AUTOMQ;
+ if (copy_to_user(argp, &steering, sizeof(steering)))
+ ret = -EFAULT;
+ break;
+
default:
ret = -EINVAL;
break;
diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h
index 365ade5..109760e 100644
--- a/include/uapi/linux/if_tun.h
+++ b/include/uapi/linux/if_tun.h
@@ -56,6 +56,9 @@
*/
#define TUNSETVNETBE _IOW('T', 222, int)
#define TUNGETVNETBE _IOR('T', 223, int)
+#define TUNSETSTEERING _IOW('T', 224, unsigned int)
+#define TUNGETSTEERING _IOR('T', 225, unsigned int)
+#define TUNGETSTEERINGFEATURES _IOR('T', 226, unsigned int)

/* TUNSETIFF ifr flags */
#define IFF_TUN 0x0001
@@ -70,6 +73,8 @@
#define IFF_MULTI_QUEUE 0x0100
#define IFF_ATTACH_QUEUE 0x0200
#define IFF_DETACH_QUEUE 0x0400
+#define IFF_MULTI_STEERING 0x2000
+
/* read-only flag */
#define IFF_PERSIST 0x0800
#define IFF_NOFILTER 0x1000
@@ -106,4 +111,6 @@ struct tun_filter {
__u8 addr[0][ETH_ALEN];
};

+#define TUN_STEERING_AUTOMQ 0x01 /* Automatic flow steering */
+
#endif /* _UAPI__IF_TUN_H */
--
2.7.4