2007-10-07 14:35:35

by Mattias Nissler

[permalink] [raw]
Subject: [PATCH] mac80211: Defer setting of RX_FLAG_DECRYPTED.

The decryption handlers will skip the frame if the RX_FLAG_DECRYPTED
flag is set, so the early flag setting introduced by Johannes breaks
decryption. To work around this, call the handlers first and then set
the flag.

Signed-off-by: Mattias Nissler <[email protected]>
---
net/mac80211/rx.c | 20 +++++++++++---------
1 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index de3f7ae..34699a1 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -424,6 +424,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
int keyidx;
int hdrlen;
+ ieee80211_txrx_result result = TXRX_DROP;
struct ieee80211_key *stakey = NULL;

/*
@@ -522,21 +523,22 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
ieee80211_wep_is_weak_iv(rx->skb, rx->key))
rx->sta->wep_weak_iv_count++;

- /* either the frame will be decrypted or dropped */
- rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
-
switch (rx->key->conf.alg) {
case ALG_WEP:
- return ieee80211_crypto_wep_decrypt(rx);
+ result = ieee80211_crypto_wep_decrypt(rx);
+ break;
case ALG_TKIP:
- return ieee80211_crypto_tkip_decrypt(rx);
+ result = ieee80211_crypto_tkip_decrypt(rx);
+ break;
case ALG_CCMP:
- return ieee80211_crypto_ccmp_decrypt(rx);
+ result = ieee80211_crypto_ccmp_decrypt(rx);
+ break;
}

- /* not reached */
- WARN_ON(1);
- return TXRX_DROP;
+ /* either the frame will be decrypted or dropped */
+ rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
+
+ return result;
}

static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
--
1.5.3



2007-10-09 09:12:42

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH] mac80211: Defer setting of RX_FLAG_DECRYPTED.

On Mon, 2007-10-08 at 11:34 +0200, Johannes Berg wrote:

> Huh. Sorry about that. I had a patch like this initially but then wanted
> to not clutter the code. I think we should instead remove the checks
> from the actual decryption functions though. Mind making a patch for
> that?

Never mind. This looks better since it doesn't require rewriting half
the crypto code.

johannes


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2007-10-08 09:34:20

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH] mac80211: Defer setting of RX_FLAG_DECRYPTED.

On Sun, 2007-10-07 at 16:35 +0200, Mattias Nissler wrote:
> The decryption handlers will skip the frame if the RX_FLAG_DECRYPTED
> flag is set, so the early flag setting introduced by Johannes breaks
> decryption. To work around this, call the handlers first and then set
> the flag.

Huh. Sorry about that. I had a patch like this initially but then wanted
to not clutter the code. I think we should instead remove the checks
from the actual decryption functions though. Mind making a patch for
that?

johannes


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2007-10-07 15:05:59

by Mattias Nissler

[permalink] [raw]
Subject: Re: [PATCH] mac80211: Defer setting of RX_FLAG_DECRYPTED.

On Sun, 2007-10-07 at 16:53 +0200, Michael Buesch wrote:
> On Sunday 07 October 2007 16:35:31 Mattias Nissler wrote:
> > + /* either the frame will be decrypted or dropped */
>
> I think this comment doesn't apply then anymore, eh?

Well, I changed the wording to "has been decrypted or will be dropped".

Mattias


The decryption handlers will skip the frame if the RX_FLAG_DECRYPTED
flag is set, so the early flag setting introduced by Johannes breaks
decryption. To work around this, call the handlers first and then set
the flag.

Signed-off-by: Mattias Nissler <[email protected]>
---
net/mac80211/rx.c | 20 +++++++++++---------
1 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index de3f7ae..34699a1 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -424,6 +424,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data
*rx)
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)
rx->skb->data;
int keyidx;
int hdrlen;
+ ieee80211_txrx_result result = TXRX_DROP;
struct ieee80211_key *stakey = NULL;

/*
@@ -522,21 +523,22 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data
*rx)
ieee80211_wep_is_weak_iv(rx->skb, rx->key))
rx->sta->wep_weak_iv_count++;

- /* either the frame will be decrypted or dropped */
- rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
-
switch (rx->key->conf.alg) {
case ALG_WEP:
- return ieee80211_crypto_wep_decrypt(rx);
+ result = ieee80211_crypto_wep_decrypt(rx);
+ break;
case ALG_TKIP:
- return ieee80211_crypto_tkip_decrypt(rx);
+ result = ieee80211_crypto_tkip_decrypt(rx);
+ break;
case ALG_CCMP:
- return ieee80211_crypto_ccmp_decrypt(rx);
+ result = ieee80211_crypto_ccmp_decrypt(rx);
+ break;
}

- /* not reached */
- WARN_ON(1);
- return TXRX_DROP;
+ /* either the frame has been decrypted or will be dropped */
+ rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
+
+ return result;
}

static void ap_sta_ps_start(struct net_device *dev, struct sta_info
*sta)
--
1.5.3



2007-10-07 14:54:29

by Michael Büsch

[permalink] [raw]
Subject: Re: [PATCH] mac80211: Defer setting of RX_FLAG_DECRYPTED.

On Sunday 07 October 2007 16:35:31 Mattias Nissler wrote:
> The decryption handlers will skip the frame if the RX_FLAG_DECRYPTED
> flag is set, so the early flag setting introduced by Johannes breaks
> decryption. To work around this, call the handlers first and then set
> the flag.
>
> Signed-off-by: Mattias Nissler <[email protected]>
> ---
> net/mac80211/rx.c | 20 +++++++++++---------
> 1 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index de3f7ae..34699a1 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -424,6 +424,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
> struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
> int keyidx;
> int hdrlen;
> + ieee80211_txrx_result result = TXRX_DROP;
> struct ieee80211_key *stakey = NULL;
>
> /*
> @@ -522,21 +523,22 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data *rx)
> ieee80211_wep_is_weak_iv(rx->skb, rx->key))
> rx->sta->wep_weak_iv_count++;
>
> - /* either the frame will be decrypted or dropped */
> - rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
> -
> switch (rx->key->conf.alg) {
> case ALG_WEP:
> - return ieee80211_crypto_wep_decrypt(rx);
> + result = ieee80211_crypto_wep_decrypt(rx);
> + break;
> case ALG_TKIP:
> - return ieee80211_crypto_tkip_decrypt(rx);
> + result = ieee80211_crypto_tkip_decrypt(rx);
> + break;
> case ALG_CCMP:
> - return ieee80211_crypto_ccmp_decrypt(rx);
> + result = ieee80211_crypto_ccmp_decrypt(rx);
> + break;
> }
>
> - /* not reached */
> - WARN_ON(1);
> - return TXRX_DROP;
> + /* either the frame will be decrypted or dropped */

I think this comment doesn't apply then anymore, eh?

> + rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
> +
> + return result;
> }
>
> static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)



--
Greetings Michael.

2007-10-10 08:44:22

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH] mac80211: Defer setting of RX_FLAG_DECRYPTED.

On Sun, 2007-10-07 at 17:05 +0200, Mattias Nissler wrote:

> The decryption handlers will skip the frame if the RX_FLAG_DECRYPTED
> flag is set, so the early flag setting introduced by Johannes breaks
> decryption. To work around this, call the handlers first and then set
> the flag.
>
> Signed-off-by: Mattias Nissler <[email protected]>

Reviewed-by: Johannes Berg <[email protected]>

However, the patch is mangled (line-wrapped)

> ---
> net/mac80211/rx.c | 20 +++++++++++---------
> 1 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index de3f7ae..34699a1 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -424,6 +424,7 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data
> *rx)
> struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)
> rx->skb->data;
> int keyidx;
> int hdrlen;
> + ieee80211_txrx_result result = TXRX_DROP;
> struct ieee80211_key *stakey = NULL;
>
> /*
> @@ -522,21 +523,22 @@ ieee80211_rx_h_decrypt(struct ieee80211_txrx_data
> *rx)
> ieee80211_wep_is_weak_iv(rx->skb, rx->key))
> rx->sta->wep_weak_iv_count++;
>
> - /* either the frame will be decrypted or dropped */
> - rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
> -
> switch (rx->key->conf.alg) {
> case ALG_WEP:
> - return ieee80211_crypto_wep_decrypt(rx);
> + result = ieee80211_crypto_wep_decrypt(rx);
> + break;
> case ALG_TKIP:
> - return ieee80211_crypto_tkip_decrypt(rx);
> + result = ieee80211_crypto_tkip_decrypt(rx);
> + break;
> case ALG_CCMP:
> - return ieee80211_crypto_ccmp_decrypt(rx);
> + result = ieee80211_crypto_ccmp_decrypt(rx);
> + break;
> }
>
> - /* not reached */
> - WARN_ON(1);
> - return TXRX_DROP;
> + /* either the frame has been decrypted or will be dropped */
> + rx->u.rx.status->flag |= RX_FLAG_DECRYPTED;
> +
> + return result;
> }
>
> static void ap_sta_ps_start(struct net_device *dev, struct sta_info
> *sta)


Attachments:
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2007-10-10 21:07:22

by Mattias Nissler

[permalink] [raw]
Subject: Re: [PATCH] mac80211: Defer setting of RX_FLAG_DECRYPTED.

On Tue, 2007-10-09 at 22:12 +0200, Johannes Berg wrote:
> On Sun, 2007-10-07 at 17:05 +0200, Mattias Nissler wrote:
>
> > The decryption handlers will skip the frame if the RX_FLAG_DECRYPTED
> > flag is set, so the early flag setting introduced by Johannes breaks
> > decryption. To work around this, call the handlers first and then set
> > the flag.
> >
> > Signed-off-by: Mattias Nissler <[email protected]>
>
> Reviewed-by: Johannes Berg <[email protected]>
>
> However, the patch is mangled (line-wrapped)

Sorry. Comes from editing patches manually. I see John already took care
of it ;-)

Mattias