llc2: Fix return statement of llc_stat_ev_rx_null_dsap_xid_c (and _test_c)
authorChan Shu Tak, Alex <alexchan@task.com.hk>
Thu, 19 Dec 2019 06:16:18 +0000 (14:16 +0800)
committerDavid S. Miller <davem@davemloft.net>
Sat, 21 Dec 2019 05:19:36 +0000 (21:19 -0800)
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 return statement of llc_stat_ev_rx_null_dsap_xid_c returns 1
when the incoming frame is not a NULL XID frame and 0 otherwise. Hence, a
NULL XID response is returned unexpectedly, e.g. when the incoming frame is
a NULL TEST command.

To fix the error, simply remove the conditional operator.

A similar error in llc_stat_ev_rx_null_dsap_test_c is also fixed.

Signed-off-by: Chan Shu Tak, Alex <alexchan@task.com.hk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/llc/llc_station.c

index 204a835..c29170e 100644 (file)
@@ -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;                              /* 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;                              /* NULL DSAP */
 }
 
 static int llc_station_ac_send_xid_r(struct sk_buff *skb)