2007-12-09 12:33:51

by Ron Rindjunsky

[permalink] [raw]
Subject: [PATCH 1/1] mac80211: pass in PS_POLL frames

This patch fixes should_drop_frame function to pass in ps poll control
frames required for power save functioanlity. Interface types that do not
have interest for PS POLL frames now drop it in handler.

Signed-off-by: Ron Rindjunsky <[email protected]>
---
net/mac80211/ieee80211_i.h | 5 +++++
net/mac80211/rx.c | 10 ++++++++--
net/mac80211/util.c | 6 +++++-
3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 2476cc5..a7746da 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -58,6 +58,11 @@ struct ieee80211_local;
* increased memory use (about 2 kB of RAM per entry). */
#define IEEE80211_FRAGMENT_MAX 4

+/* IEEE 80211.11 minimal headers length */
+#define IEEE80211_HDR_MIN_LEN_CTRL 16
+#define IEEE80211_HDR_MIN_LEN_DATA 24
+#define IEEE80211_HDR_MIN_LEN_MGMT 24
+
struct ieee80211_fragment_entry {
unsigned long first_frag_time;
unsigned int seq;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 9009444..3bd9edc 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -61,8 +61,10 @@ static inline int should_drop_frame(struct ieee80211_rx_status *status,
return 1;
if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
return 1;
- if ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
- cpu_to_le16(IEEE80211_FTYPE_CTL))
+ if (((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_FTYPE)) ==
+ cpu_to_le16(IEEE80211_FTYPE_CTL)) &&
+ ((hdr->frame_control & cpu_to_le16(IEEE80211_FCTL_STYPE)) !=
+ cpu_to_le16(IEEE80211_STYPE_PSPOLL)))
return 1;
return 0;
}
@@ -874,6 +876,7 @@ ieee80211_rx_h_defragment(struct ieee80211_txrx_data *rx)
static ieee80211_txrx_result
ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
{
+ struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
struct sk_buff *skb;
int no_pending_pkts;
DECLARE_MAC_BUF(mac);
@@ -884,6 +887,9 @@ ieee80211_rx_h_ps_poll(struct ieee80211_txrx_data *rx)
!(rx->flags & IEEE80211_TXRXD_RXRA_MATCH)))
return TXRX_CONTINUE;

+ if (sdata->type == IEEE80211_IF_TYPE_STA)
+ return TXRX_DROP;
+
skb = skb_dequeue(&rx->sta->tx_filtered);
if (!skb) {
skb = skb_dequeue(&rx->sta->ps_tx_buf);
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index f90287a..b53644c 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -134,13 +134,15 @@ u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len)
{
u16 fc;

- if (len < 24)
+ if (len < IEEE80211_HDR_MIN_LEN_CTRL)
return NULL;

fc = le16_to_cpu(hdr->frame_control);

switch (fc & IEEE80211_FCTL_FTYPE) {
case IEEE80211_FTYPE_DATA:
+ if (len < IEEE80211_HDR_MIN_LEN_DATA)
+ return NULL;
switch (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) {
case IEEE80211_FCTL_TODS:
return hdr->addr1;
@@ -153,6 +155,8 @@ u8 *ieee80211_get_bssid(struct ieee80211_hdr *hdr, size_t len)
}
break;
case IEEE80211_FTYPE_MGMT:
+ if (len < IEEE80211_HDR_MIN_LEN_MGMT)
+ return NULL;
return hdr->addr3;
case IEEE80211_FTYPE_CTL:
if ((fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)
--
1.5.3.3
---------------------------------------------------------------------
Intel Israel (74) Limited

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2007-12-10 08:20:02

by Ron Rindjunsky

[permalink] [raw]
Subject: Re: [PATCH 1/1] mac80211: pass in PS_POLL frames

> > +/* IEEE 80211.11 minimal headers length */
> > +#define IEEE80211_HDR_MIN_LEN_CTRL 16
>
> Where does this value 16 come from? It is likely the shortest length one
> would receive from hardware/firmware in normal mode, but it is not the
> shortest length for a valid IEEE 802.11 control frame. Both CTS and ACK
> frames have only 10 octets in the header (just one address). Having
> IEEE80211_HDR_MIN_LEN_CTRL defined to 16 would be a bit confusing.. CTS
> and ACK frames are received at least in monitor mode, so these frames
> with 10 octet headers will need to be processed in some cases.

this check comes after monitor interface has been fed, so it shouldn't
damage it.
My intention in the name was "min length for a frame that i want to
pass" so i see why it can cause confusion. As no good name for it
comes to my mind i think i will drop the #defines , add remarks to
explain length use, and will welcome any change for better naming
convention.

ron

>
> --
> Jouni Malinen PGP id EFC895FA

2007-12-10 05:00:43

by Jouni Malinen

[permalink] [raw]
Subject: Re: [PATCH 1/1] mac80211: pass in PS_POLL frames

On Sun, Dec 09, 2007 at 02:33:42PM +0200, Ron Rindjunsky wrote:

> +/* IEEE 80211.11 minimal headers length */
> +#define IEEE80211_HDR_MIN_LEN_CTRL 16

Where does this value 16 come from? It is likely the shortest length one
would receive from hardware/firmware in normal mode, but it is not the
shortest length for a valid IEEE 802.11 control frame. Both CTS and ACK
frames have only 10 octets in the header (just one address). Having
IEEE80211_HDR_MIN_LEN_CTRL defined to 16 would be a bit confusing.. CTS
and ACK frames are received at least in monitor mode, so these frames
with 10 octet headers will need to be processed in some cases.

--
Jouni Malinen PGP id EFC895FA

2007-12-10 04:05:27

by Michael Wu

[permalink] [raw]
Subject: Re: [PATCH 1/1] mac80211: pass in PS_POLL frames

On Sunday 09 December 2007 07:33:42 Ron Rindjunsky wrote:
> This patch fixes should_drop_frame function to pass in ps poll control
> frames required for power save functioanlity. Interface types that do not
> have interest for PS POLL frames now drop it in handler.
>
> Signed-off-by: Ron Rindjunsky <[email protected]>
> ---
> net/mac80211/ieee80211_i.h | 5 +++++
> net/mac80211/rx.c | 10 ++++++++--
> net/mac80211/util.c | 6 +++++-
> 3 files changed, 18 insertions(+), 3 deletions(-)
>
> diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
> index 2476cc5..a7746da 100644
> --- a/net/mac80211/ieee80211_i.h
> +++ b/net/mac80211/ieee80211_i.h
> @@ -58,6 +58,11 @@ struct ieee80211_local;
> * increased memory use (about 2 kB of RAM per entry). */
> #define IEEE80211_FRAGMENT_MAX 4
>
> +/* IEEE 80211.11 minimal headers length */
One too many '11's in there.

> +#define IEEE80211_HDR_MIN_LEN_CTRL 16
> +#define IEEE80211_HDR_MIN_LEN_DATA 24
> +#define IEEE80211_HDR_MIN_LEN_MGMT 24
> +
This isn't really related to fixing the PS_POLL frame passing. It's a good
idea however - please put it in include/linux/ieee80211.h and follow the
naming conventions there.

Otherwise looks fine.

Thanks,
-Michael Wu


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