linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Chan Shu Tak, Alex" <alexchan@task.com.hk>
To: unlisted-recipients:; (no To-header on input)
Cc: "Chan Shu Tak, Alex" <alexchan@task.com.hk>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [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.
Date: Tue, 17 Dec 2019 12:00:36 +0800	[thread overview]
Message-ID: <1576555237-4037-1-git-send-email-alexchan@task.com.hk> (raw)
In-Reply-To: <1576340820-4929-1-git-send-email-alexchan@task.com.hk>

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


  parent reply	other threads:[~2019-12-17  4:11 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
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 [this message]
2019-12-18  6:18   ` [PATCH v2] llc2: Remove " David Miller
2019-12-18 15:07     ` Chan Shu Tak, ALex
2019-12-18 20:24       ` David Miller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1576555237-4037-1-git-send-email-alexchan@task.com.hk \
    --to=alexchan@task.com.hk \
    --cc=davem@davemloft.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).