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* [PATCH] llc2: Reverse the true/false statements of the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c.
@ 2019-12-14 16:26 Chan Shu Tak, Alex
  2019-12-17  0:26 ` David Miller
  2019-12-17  4:00 ` [PATCH v2] llc2: Remove " Chan Shu Tak, Alex
  0 siblings, 2 replies; 6+ messages in thread
From: Chan Shu Tak, Alex @ 2019-12-14 16:26 UTC (permalink / raw)
  Cc: Chan Shu Tak, Alex, David S. Miller, netdev, linux-kernel

From: "Chan Shu Tak, Alex" <alexchan@task.com.hk>

When a frame with NULL DSAP is received, llc_station_rcv is called.
In turn, llc_stat_ev_rx_null_dsap_xid_c is called to check if it is
a NULL XID frame. The original true statement returns 0 while the
false statement returns 1. As a result, an incoming NULL TEST frame
would trigger an XID response instead.

The same error is found in llc_stat_ev_rx_null_dsap_test_c and fixed.

Signed-off-by: Chan Shu Tak, Alex <alexchan@task.com.hk>
---
 net/llc/llc_station.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/llc/llc_station.c b/net/llc/llc_station.c
index 204a835..90955d7 100644
--- a/net/llc/llc_station.c
+++ b/net/llc/llc_station.c
@@ -32,7 +32,7 @@ static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
 	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
 	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
 	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
-	       !pdu->dsap ? 0 : 1;			/* NULL DSAP value */
+	       !pdu->dsap ? 1 : 0;			/* NULL DSAP value */
 }
 
 static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
@@ -42,7 +42,7 @@ static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
 	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
 	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
 	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST &&
-	       !pdu->dsap ? 0 : 1;			/* NULL DSAP */
+	       !pdu->dsap ? 1 : 0;			/* NULL DSAP */
 }
 
 static int llc_station_ac_send_xid_r(struct sk_buff *skb)
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] llc2: Reverse the true/false statements of the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c.
  2019-12-14 16:26 [PATCH] llc2: Reverse the true/false statements of the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c Chan Shu Tak, Alex
@ 2019-12-17  0:26 ` David Miller
  2019-12-17  4:00 ` [PATCH v2] llc2: Remove " Chan Shu Tak, Alex
  1 sibling, 0 replies; 6+ messages in thread
From: David Miller @ 2019-12-17  0:26 UTC (permalink / raw)
  To: alexchan; +Cc: netdev, linux-kernel

From: "Chan Shu Tak, Alex" <alexchan@task.com.hk>
Date: Sun, 15 Dec 2019 00:26:58 +0800

> @@ -32,7 +32,7 @@ static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
>  	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
>  	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
>  	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
> -	       !pdu->dsap ? 0 : 1;			/* NULL DSAP value */
> +	       !pdu->dsap ? 1 : 0;			/* NULL DSAP value */
>  }
>  
>  static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
> @@ -42,7 +42,7 @@ static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
>  	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
>  	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
>  	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST &&
> -	       !pdu->dsap ? 0 : 1;			/* NULL DSAP */
> +	       !pdu->dsap ? 1 : 0;			/* NULL DSAP */
>  }
>  

These are both plain booleans now then.  Just plain "!pdu->dsap" is
therefore, sufficient.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v2] llc2: Remove the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c.
  2019-12-14 16:26 [PATCH] llc2: Reverse the true/false statements of the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c Chan Shu Tak, Alex
  2019-12-17  0:26 ` David Miller
@ 2019-12-17  4:00 ` Chan Shu Tak, Alex
  2019-12-18  6:18   ` David Miller
  1 sibling, 1 reply; 6+ messages in thread
From: Chan Shu Tak, Alex @ 2019-12-17  4:00 UTC (permalink / raw)
  Cc: Chan Shu Tak, Alex, David S. Miller, netdev, linux-kernel

From: "Chan Shu Tak, Alex" <alexchan@task.com.hk>

When a frame with NULL DSAP is received, llc_station_rcv is called.
In turn, llc_stat_ev_rx_null_dsap_xid_c is called to check if it is a NULL
XID frame. The original condition operator returns 1 when the incoming
frame is not a NULL XID frame and 0 otherwise. As a result, an incoming
NULL TEST frame would trigger an XID response instead.

To fix the error, we just need to remove the condition operator.

The same error is found in llc_stat_ev_rx_null_dsap_test_c and fixed.

Signed-off-by: Chan Shu Tak, Alex <alexchan@task.com.hk>
---
 net/llc/llc_station.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/llc/llc_station.c b/net/llc/llc_station.c
index 90955d7..c29170e 100644
--- a/net/llc/llc_station.c
+++ b/net/llc/llc_station.c
@@ -32,7 +32,7 @@ static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
 	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
 	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
 	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
-	       !pdu->dsap ? 1 : 0;			/* NULL DSAP value */
+	       !pdu->dsap;				/* NULL DSAP value */
 }
 
 static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
@@ -42,7 +42,7 @@ static int llc_stat_ev_rx_null_dsap_test_c(struct sk_buff *skb)
 	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
 	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
 	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_TEST &&
-	       !pdu->dsap ? 1 : 0;			/* NULL DSAP */
+	       !pdu->dsap;				/* NULL DSAP */
 }
 
 static int llc_station_ac_send_xid_r(struct sk_buff *skb)
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] llc2: Remove the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c.
  2019-12-17  4:00 ` [PATCH v2] llc2: Remove " Chan Shu Tak, Alex
@ 2019-12-18  6:18   ` David Miller
  2019-12-18 15:07     ` Chan Shu Tak, ALex
  0 siblings, 1 reply; 6+ messages in thread
From: David Miller @ 2019-12-18  6:18 UTC (permalink / raw)
  To: alexchan; +Cc: netdev, linux-kernel

From: "Chan Shu Tak, Alex" <alexchan@task.com.hk>
Date: Tue, 17 Dec 2019 12:00:36 +0800

> @@ -32,7 +32,7 @@ static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
>  	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
>  	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
>  	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
> -	       !pdu->dsap ? 1 : 0;			/* NULL DSAP value */
> +	       !pdu->dsap;				/* NULL DSAP value */

This isn't a v2 of your patch, it's a patch against v1 of your patch.

Please do this properly, thank you.

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] llc2: Remove the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c.
  2019-12-18  6:18   ` David Miller
@ 2019-12-18 15:07     ` Chan Shu Tak, ALex
  2019-12-18 20:24       ` David Miller
  0 siblings, 1 reply; 6+ messages in thread
From: Chan Shu Tak, ALex @ 2019-12-18 15:07 UTC (permalink / raw)
  To: David Miller; +Cc: netdev, linux-kernel

On Tue, Dec 17, 2019 at 10:18:46PM -0800, David Miller wrote:
> From: "Chan Shu Tak, Alex" <alexchan@task.com.hk>
> Date: Tue, 17 Dec 2019 12:00:36 +0800
> 
> > @@ -32,7 +32,7 @@ static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
> >  	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
> >  	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
> >  	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
> > -	       !pdu->dsap ? 1 : 0;			/* NULL DSAP value */
> > +	       !pdu->dsap;				/* NULL DSAP value */
> 
> This isn't a v2 of your patch, it's a patch against v1 of your patch.
> 
> Please do this properly, thank you.

Thanks for your comments and patience and sorry for the troubles that I caused.

I will revise my patch and try again.

In this case, should I start anew or continue on this thread? 

Thanks again for your time.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v2] llc2: Remove the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c.
  2019-12-18 15:07     ` Chan Shu Tak, ALex
@ 2019-12-18 20:24       ` David Miller
  0 siblings, 0 replies; 6+ messages in thread
From: David Miller @ 2019-12-18 20:24 UTC (permalink / raw)
  To: alexchan; +Cc: netdev, linux-kernel

From: "Chan Shu Tak, ALex" <alexchan@task.com.hk>
Date: Wed, 18 Dec 2019 23:07:37 +0800

> On Tue, Dec 17, 2019 at 10:18:46PM -0800, David Miller wrote:
>> From: "Chan Shu Tak, Alex" <alexchan@task.com.hk>
>> Date: Tue, 17 Dec 2019 12:00:36 +0800
>> 
>> > @@ -32,7 +32,7 @@ static int llc_stat_ev_rx_null_dsap_xid_c(struct sk_buff *skb)
>> >  	return LLC_PDU_IS_CMD(pdu) &&			/* command PDU */
>> >  	       LLC_PDU_TYPE_IS_U(pdu) &&		/* U type PDU */
>> >  	       LLC_U_PDU_CMD(pdu) == LLC_1_PDU_CMD_XID &&
>> > -	       !pdu->dsap ? 1 : 0;			/* NULL DSAP value */
>> > +	       !pdu->dsap;				/* NULL DSAP value */
>> 
>> This isn't a v2 of your patch, it's a patch against v1 of your patch.
>> 
>> Please do this properly, thank you.
> 
> Thanks for your comments and patience and sorry for the troubles that I caused.
> 
> I will revise my patch and try again.
> 
> In this case, should I start anew or continue on this thread? 

Post a new patch that does the full change from "!pdu->dsap ? 0 : 1" to just
plain "!pdu->dsap".

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2019-12-18 20:24 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-12-14 16:26 [PATCH] llc2: Reverse the true/false statements of the condition operator in llc_stat_ev_rx_null_dsap_xid_c and llc_stat_ev_rx_null_dsap_test_c Chan Shu Tak, Alex
2019-12-17  0:26 ` David Miller
2019-12-17  4:00 ` [PATCH v2] llc2: Remove " Chan Shu Tak, Alex
2019-12-18  6:18   ` David Miller
2019-12-18 15:07     ` Chan Shu Tak, ALex
2019-12-18 20:24       ` David Miller

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