[dpdk-dev,10/17] net/fm10k/base: improve VF's multi-bit VLAN update requests
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Commit Message
The VF uses a multi-bit update request to clear unused VLANs whenever it
resets. However, an accident in a previous refector 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>
---
drivers/net/fm10k/base/fm10k_pf.c | 30 ++++++++++++++++++++++--------
1 file changed, 22 insertions(+), 8 deletions(-)
Comments
On 3/3/2017 3:17 AM, Qi Zhang wrote:
> The VF uses a multi-bit update request to clear unused VLANs whenever it
> resets. However, an accident in a previous refector broke multi-bit
s/refector/refactor
> 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>
<...>
@@ -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);