[PATCH v2] iwlwifi: mvm: allow monitor mode capture in STA mode

[gavinli]

From: Gavin Li 

Open up the filter if there is a monitor interface configured; this
allows all packets on the channel to be captured even if the device is
in STA mode and associated to a BSS.

Signed-off-by: Gavin Li 
---
 drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c |  3 +-
 drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c | 42 +++
 drivers/net/wireless/intel/iwlwifi/mvm/mvm.h  |  3 ++
 3 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c 
b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
index fd2fc46e2fe5..ea98fc040aa8 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac-ctxt.c
@@ -752,7 +752,8 @@ static void iwl_mvm_mac_ctxt_cmd_common(struct iwl_mvm *mvm,
cpu_to_le32(vif->bss_conf.use_short_slot ?
MAC_FLG_SHORT_SLOT : 0);
 
-   cmd->filter_flags = cpu_to_le32(MAC_FILTER_ACCEPT_GRP);
+   cmd->filter_flags = cpu_to_le32(mvm->addl_filter_flags |
+   MAC_FILTER_ACCEPT_GRP);
 
for (i = 0; i < IEEE80211_NUM_ACS; i++) {
u8 txf = iwl_mvm_ac_to_tx_fifo[i];
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c 
b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
index db5ad222e5ea..7c6d30ea3cf1 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c
@@ -1641,6 +1641,13 @@ static u64 iwl_mvm_prepare_multicast(struct ieee80211_hw 
*hw,
return (u64)(unsigned long)cmd;
 }
 
+static void iwl_mvm_addl_ff_iface_iterator(
+   void *_mvm, u8 *mac, struct ieee80211_vif *vif)
+{
+   struct iwl_mvm *mvm = _mvm;
+   iwl_mvm_mac_ctxt_changed(mvm, vif, false, NULL);
+}
+
 static void iwl_mvm_configure_filter(struct ieee80211_hw *hw,
 unsigned int changed_flags,
 unsigned int *total_flags,
@@ -1648,20 +1655,41 @@ static void iwl_mvm_configure_filter(struct 
ieee80211_hw *hw,
 {
struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
struct iwl_mcast_filter_cmd *cmd = (void *)(unsigned long)multicast;
+   const u32 supported_filters =
+   FIF_BCN_PRBRESP_PROMISC |
+   FIF_CONTROL |
+   FIF_OTHER_BSS |
+   FIF_PROBE_REQ;
+   u32 addl_filter_flags = 0;
+
+   *total_flags &= supported_filters;
+   if (*total_flags & FIF_BCN_PRBRESP_PROMISC)
+   addl_filter_flags |= MAC_FILTER_IN_BEACON;
+   if (*total_flags & FIF_CONTROL)
+   addl_filter_flags |= MAC_FILTER_IN_CONTROL_AND_MGMT;
+   if (*total_flags & FIF_OTHER_BSS)
+   addl_filter_flags |= MAC_FILTER_IN_CONTROL_AND_MGMT |
+   MAC_FILTER_IN_PROMISC |
+   MAC_FILTER_IN_BEACON;
+   if (*total_flags & FIF_PROBE_REQ)
+   addl_filter_flags |= MAC_FILTER_IN_PROBE_REQUEST;
 
+   /* replace previous configuration */
mutex_lock(&mvm->mutex);
 
-   /* replace previous configuration */
+   if (mvm->addl_filter_flags != addl_filter_flags) {
+   mvm->addl_filter_flags = addl_filter_flags;
+   ieee80211_iterate_active_interfaces(
+   mvm->hw, IEEE80211_IFACE_ITER_NORMAL,
+   iwl_mvm_addl_ff_iface_iterator, mvm);
+   }
+
kfree(mvm->mcast_filter_cmd);
mvm->mcast_filter_cmd = cmd;
+   if (cmd)
+   iwl_mvm_recalc_multicast(mvm);
 
-   if (!cmd)
-   goto out;
-
-   iwl_mvm_recalc_multicast(mvm);
-out:
mutex_unlock(&mvm->mutex);
-   *total_flags = 0;
 }
 
 static void iwl_mvm_config_iface_filter(struct ieee80211_hw *hw,
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h 
b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index 52f8d7a6a7dc..827c413157c7 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -832,6 +832,9 @@ struct iwl_mvm {
/* configured by mac80211 */
u32 rts_threshold;
 
+   /* packets to pass as requested by mac80211 */
+   u32 addl_filter_flags;
+
/* Scan status, cmd (pre-allocated) and auxiliary station */
unsigned int scan_status;
void *scan_cmd;
-- 
2.14.1

Re: [PATCH v2] iwlwifi: mvm: allow monitor mode capture in STA mode

[Coelho, Luciano]

Hi Gavin,

On Thu, 2017-09-14 at 22:11 -0700, gavi...@thegavinli.com wrote:
> From: Gavin Li 
>
> Open up the filter if there is a monitor interface configured; this
> allows all packets on the channel to be captured even if the device is
> in STA mode and associated to a BSS.
> 
> Signed-off-by: Gavin Li 
> ---

Sorry for the delay in responding, we were discussing this patch
internally.

Unfortunately this is not something that our firmware officially
supports, so we cannot allow it in the driver.  The firmware doesn't
*block* this from working, but there are no guarantees that it will work
and that there will not be any side-effects.

If this works for you, feel free to use it (that's one of the beauties
of open source), but I won't apply it in the mainline driver.


--
Cheers,
Luca.

Re: [PATCH v2] iwlwifi: mvm: allow monitor mode capture in STA mode

[Gavin Li]

Hi Luciano,

Thanks for the update. I was hoping that it would be supported since I
remember that iwldvm had no problem with it in the past.

Best,
Gavin

On Tue, Sep 26, 2017 at 12:59 AM, Coelho, Luciano
 wrote:
> Hi Gavin,
>
> On Thu, 2017-09-14 at 22:11 -0700, gavi...@thegavinli.com wrote:
>> From: Gavin Li 
>>
>> Open up the filter if there is a monitor interface configured; this
>> allows all packets on the channel to be captured even if the device is
>> in STA mode and associated to a BSS.
>>
>> Signed-off-by: Gavin Li 
>> ---
>
> Sorry for the delay in responding, we were discussing this patch
> internally.
>
> Unfortunately this is not something that our firmware officially
> supports, so we cannot allow it in the driver.  The firmware doesn't
> *block* this from working, but there are no guarantees that it will work
> and that there will not be any side-effects.
>
> If this works for you, feel free to use it (that's one of the beauties
> of open source), but I won't apply it in the mainline driver.
>
>
> --
> Cheers,
> Luca.

Re: [PATCH v2] iwlwifi: mvm: allow monitor mode capture in STA mode

[Coelho, Luciano]

On Tue, 2017-09-26 at 10:29 -0700, Gavin Li wrote:
> Hi Luciano,

Hi,

> Thanks for the update. I was hoping that it would be supported since I
> remember that iwldvm had no problem with it in the past.

As I said, it *may* work for you as it did with iwldvm, but we cannot
guarantee that it will work and we cannot support it officially.  Thus I
can't apply this to the official driver, but you can use it at your own
risk. ;)

--
Cheers,
Luca.