tipc: clean up connection protocol reception function

We simplify the code for receiving connection probes, leveraging the
recently introduced tipc_msg_reverse() function. We also stick to
the principle of sending a possible response message directly from
the calling (tipc_sk_rcv or backlog_rcv) functions, hence making
the call chain shallower and easier to follow.

We make one small protocol change here, allowed according to
the spec. If a protocol message arrives from a remote socket that
is not the one we are connected to, we are currently generating a
connection abort message and send it to the source. This behavior
is unnecessary, and might even be a security risk, so instead we
now choose to only ignore the message. The consequnce for the sender
is that he will need longer time to discover his mistake (until the
next timeout), but this is an extreme corner case, and may happen
anyway under other circumstances, so we deem this change acceptable.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 50 deletions

diff --git a/net/tipc/port.c b/net/tipc/port.c
index dcc6309..9f53d5a 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -42,8 +42,6 @@
 
 /* Connection management: */
 #define PROBING_INTERVAL 3600000	/* [ms] => 1 h */
-#define CONFIRMED 0
-#define PROBING 1
 
 #define MAX_REJECT_SIZE 1024
 
@@ -299,11 +297,11 @@ static void port_timeout(unsigned long ref)
 	}
 
 	/* Last probe answered ? */
-	if (p_ptr->probing_state == PROBING) {
+	if (p_ptr->probing_state == TIPC_CONN_PROBING) {
 		buf = port_build_self_abort_msg(p_ptr, TIPC_ERR_NO_PORT);
 	} else {
 		buf = port_build_proto_msg(p_ptr, CONN_PROBE, 0);
-		p_ptr->probing_state = PROBING;
+		p_ptr->probing_state = TIPC_CONN_PROBING;
 		k_start_timer(&p_ptr->timer, p_ptr->probing_interval);
 	}
 	tipc_port_unlock(p_ptr);
@@ -365,51 +363,6 @@ static struct sk_buff *port_build_peer_abort_msg(struct tipc_port *p_ptr, u32 er
 	return buf;
 }
 
-void tipc_port_proto_rcv(struct tipc_port *p_ptr, struct sk_buff *buf)
-{
-	struct tipc_msg *msg = buf_msg(buf);
-	struct sk_buff *r_buf = NULL;
-	u32 destport = msg_destport(msg);
-	int wakeable;
-
-	/* Validate connection */
-	if (!p_ptr || !p_ptr->connected || !tipc_port_peer_msg(p_ptr, msg)) {
-		r_buf = tipc_buf_acquire(BASIC_H_SIZE);
-		if (r_buf) {
-			msg = buf_msg(r_buf);
-			tipc_msg_init(msg, TIPC_HIGH_IMPORTANCE, TIPC_CONN_MSG,
-				      BASIC_H_SIZE, msg_orignode(msg));
-			msg_set_errcode(msg, TIPC_ERR_NO_PORT);
-			msg_set_origport(msg, destport);
-			msg_set_destport(msg, msg_origport(msg));
-		}
-		goto exit;
-	}
-
-	/* Process protocol message sent by peer */
-	switch (msg_type(msg)) {
-	case CONN_ACK:
-		wakeable = tipc_port_congested(p_ptr) && p_ptr->congested;
-		p_ptr->acked += msg_msgcnt(msg);
-		if (!tipc_port_congested(p_ptr)) {
-			p_ptr->congested = 0;
-			if (wakeable)
-				tipc_port_wakeup(p_ptr);
-		}
-		break;
-	case CONN_PROBE:
-		r_buf = port_build_proto_msg(p_ptr, CONN_PROBE_REPLY, 0);
-		break;
-	default:
-		/* CONN_PROBE_REPLY or unrecognized - no action required */
-		break;
-	}
-	p_ptr->probing_state = CONFIRMED;
-exit:
-	tipc_link_xmit2(r_buf, msg_destnode(msg), msg_link_selector(msg));
-	kfree_skb(buf);
-}
-
 static int port_print(struct tipc_port *p_ptr, char *buf, int len, int full_id)
 {
 	struct publication *publ;
@@ -613,7 +566,7 @@ int __tipc_port_connect(u32 ref, struct tipc_port *p_ptr,
 	msg_set_hdr_sz(msg, SHORT_H_SIZE);
 
 	p_ptr->probing_interval = PROBING_INTERVAL;
-	p_ptr->probing_state = CONFIRMED;
+	p_ptr->probing_state = TIPC_CONN_OK;
 	p_ptr->connected = 1;
 	k_start_timer(&p_ptr->timer, p_ptr->probing_interval);