net/fm10k/base: improve VF multi-bit VLAN update requests

The VF uses a multi-bit update request to clear unused VLANs whenever it
resets. However, an accident in a previous refactor broke multi-bit
updates for VFs, due to misreading a comment in fm10k_vf.c and
attempting to reduce code duplication. The problem occurs because
a multi-bit request has a non-zero length, and the PF would simply drop
any request with the upper 16 bits set. In addition, a multi-bit vlan
update does not have a concept for "VLAN 0" as the single bit update
does.

A previous revision of this patch resolved the issue by simply removing
the upper 16 bit check and the iov_select_vid checks. However, this would
remove the checks for default VID and for ensuring no other VLANs can be
enabled except pf_vid when it has been set. To resolve that issue, this
revision uses the iov_select_vid when we have a single-bit update, and
denies any multi-bit update when the VLAN was administratively set by
the PF. This should be ok since the PF properly updates VLAN_TABLE when
it assigns the PF vid. This ensures that requests to add or "remove" the
PF vid work as expected, but a rogue VF could not use the multi-bit
update as a loophole to attempt receiving traffic on other VLANs.

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
This commit is contained in:
Qi Zhang 2017-03-08 01:18:58 -05:00 committed by Ferruh Yigit
parent c631e94842
commit a5db0e8004

View File

@ -1271,18 +1271,32 @@ s32 fm10k_iov_msg_mac_vlan_pf(struct fm10k_hw *hw, u32 **results,
if (err)
return err;
/* verify upper 16 bits are zero */
if (vid >> 16)
return FM10K_ERR_PARAM;
set = !(vid & FM10K_VLAN_CLEAR);
vid &= ~FM10K_VLAN_CLEAR;
err = fm10k_iov_select_vid(vf_info, (u16)vid);
if (err < 0)
return err;
/* if the length field has been set, this is a multi-bit
* update request. For multi-bit requests, simply disallow
* them when the pf_vid has been set. In this case, the PF
* should have already cleared the VLAN_TABLE, and if we
* allowed them, it could allow a rogue VF to receive traffic
* on a VLAN it was not assigned. In the single-bit case, we
* need to modify requests for VLAN 0 to use the default PF or
* SW vid when assigned.
*/
vid = err;
if (vid >> 16) {
/* prevent multi-bit requests when PF has
* administratively set the VLAN for this VF
*/
if (vf_info->pf_vid)
return FM10K_ERR_PARAM;
} else {
err = fm10k_iov_select_vid(vf_info, (u16)vid);
if (err < 0)
return err;
vid = err;
}
/* update VSI info for VF in regards to VLAN table */
err = hw->mac.ops.update_vlan(hw, vid, vf_info->vsi, set);