kernel/linux.git/drivers/net/tun.c, branch v3.15.2

drivers/net: Use RCU_INIT_POINTER(x, NULL) in tun.c

2014-03-27T04:18:09+00:00

This patch replaces rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL) The rcu_assign_pointer() ensures that the initialization of a structure is carried out before storing a pointer to that structure. And in the case of the NULL pointer, there is no structure to initialize. So, rcu_assign_pointer(p, NULL) can be safely converted to RCU_INIT_POINTER(p, NULL) Signed-off-by: Monam Agarwal Signed-off-by: David S. Miller

tun: remove bogus hardware vlan acceleration flags from vlan_features

2014-02-20T07:15:38+00:00

Even though only the outer vlan tag can be HW accelerated in the transmission path, in the TUN/TAP driver vlan_features mirrors hw_features, which happens to have the NETIF_F_HW_VLAN_?TAG_TX flags set. Because of this, during packet tranmisssion through a stacked vlan device dev_hard_start_xmit, (incorrectly) assuming that the vlan device supports hardware vlan acceleration, does not add the vlan header to the skb payload and the inner vlan tags are lost (vlan_tci contains the outer vlan tag when userspace reads the packet from the tap device). Signed-off-by: Fernando Luis Vazquez Cao Signed-off-by: Toshiaki Makita Signed-off-by: David S. Miller

netdevice: add queue selection fallback handler for ndo_select_queue

2014-02-17T05:36:34+00:00

Add a new argument for ndo_select_queue() callback that passes a fallback handler. This gets invoked through netdev_pick_tx(); fallback handler is currently __netdev_pick_tx() as most drivers invoke this function within their customized implementation in case for skbs that don't need any special handling. This fallback handler can then be replaced on other call-sites with different queue selection methods (e.g. in packet sockets, pktgen etc). This also has the nice side-effect that __netdev_pick_tx() is then only invoked from netdev_pick_tx() and export of that function to modules can be undone. Suggested-by: David S. Miller Signed-off-by: Daniel Borkmann Signed-off-by: David S. Miller

tun: add device name(iff) field to proc fdinfo entry

2014-01-29T07:46:56+00:00

A file descriptor opened for /dev/net/tun and a tun device are connected with ioctl. Though understanding the connection is important for trouble shooting, no way is given to a user to know the connected device for a given file descriptor at userland. This patch adds a new fdinfo field for the device name connected to a file descriptor opened for /dev/net/tun. Here is an example of the field: # lsof | grep tun qemu-syst 4565 qemu 25u CHR 10,200 0t138 12921 /dev/net/tun ... # cat /proc/4565/fdinfo/25 pos: 138 flags: 0104002 iff: vnet0 # ip link show dev vnet0 8: vnet0: mtu 1500 ... changelog: v2: indent iff just like the other fdinfo fields are. v3: remove unused variable. Both are suggested by David Miller . Signed-off-by: Masatake YAMATO Signed-off-by: David S. Miller

tuntap: Fix for a race in accessing numqueues

2014-01-23T05:32:56+00:00

A patch for fixing a race between queue selection and changing queues was introduced in commit 92bb73ea2("tuntap: fix a possible race between queue selection and changing queues"). The fix was to prevent the driver from re-reading the tun->numqueues more than once within tun_select_queue() using ACCESS_ONCE(). We have been experiancing 'Divide-by-zero' errors in tun_net_xmit() since we moved from 3.6 to 3.10, and believe that they come from a simular source where the value of tun->numqueues changes to zero between the first and a subsequent read of tun->numqueues. The fix is a simular use of ACCESS_ONCE(), as well as a multiply instead of a divide in the if statement. Signed-off-by: Dominic Curran Cc: Jason Wang Cc: Maxim Krasnyansky Acked-by: Jason Wang Acked-by: Max Krasnyansky Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2014-01-14T22:42:42+00:00

net: core: explicitly select a txq before doing l2 forwarding

2014-01-10T18:23:08+00:00

Currently, the tx queue were selected implicitly in ndo_dfwd_start_xmit(). The will cause several issues: - NETIF_F_LLTX were removed for macvlan, so txq lock were done for macvlan instead of lower device which misses the necessary txq synchronization for lower device such as txq stopping or frozen required by dev watchdog or control path. - dev_hard_start_xmit() was called with NULL txq which bypasses the net device watchdog. - dev_hard_start_xmit() does not check txq everywhere which will lead a crash when tso is disabled for lower device. Fix this by explicitly introducing a new param for .ndo_select_queue() for just selecting queues in the case of l2 forwarding offload. netdev_pick_tx() was also extended to accept this parameter and dev_queue_xmit_accel() was used to do l2 forwarding transmission. With this fixes, NETIF_F_LLTX could be preserved for macvlan and there's no need to check txq against NULL in dev_hard_start_xmit(). Also there's no need to keep a dedicated ndo_dfwd_start_xmit() and we can just reuse the code of dev_queue_xmit() to do the transmission. In the future, it was also required for macvtap l2 forwarding support since it provides a necessary synchronization method. Cc: John Fastabend Cc: Neil Horman Cc: e1000-devel@lists.sourceforge.net Signed-off-by: Jason Wang Acked-by: Neil Horman Acked-by: John Fastabend Signed-off-by: David S. Miller

tun, rfs: fix the incorrect hash value

2014-01-02T07:41:22+00:00

The code incorrectly save the queue index as the hash, so this patch is fixing it with the hash received in the stack receive path. Signed-off-by: Zhi Yong Wu Acked-by: Jason Wang Signed-off-by: David S. Miller

tun: Add support for RFS on tun flows

2013-12-31T18:31:34+00:00

This patch adds support so that the rps_flow_tables (RFS) can be programmed using the tun flows which are already set up to track flows for the purposes of queue selection. On the receive path (corresponding to select_queue and tun_net_xmit) the rxhash is saved in the flow_entry. The original code only does flow lookup in select_queue, so this patch adds a flow lookup in tun_net_xmit if num_queues == 1 (select_queue is not called from dev_queue_xmit->netdev_pick_tx in that case). The flow is recorded (processing CPU) in tun_flow_update (TX path), and reset when flow is deleted. Signed-off-by: Tom Herbert Signed-off-by: Zhi Yong Wu Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2013-12-18T21:42:06+00:00

Conflicts: drivers/net/ethernet/intel/i40e/i40e_main.c drivers/net/macvtap.c Both minor merge hassles, simple overlapping changes. Signed-off-by: David S. Miller