tipc: make link implementation independent from struct tipc_bearer

In reality, the link implementation is already independent from
struct tipc_bearer, in that it doesn't store any reference to it.
However, we still pass on a pointer to a bearer instance in the
function tipc_link_create(), just to have it extract some
initialization information from it.

I later commits, we need to create instances of tipc_link without
having any associated struct tipc_bearer. To facilitate this, we
want to extract the initialization data already in the creator
function in node.c, before calling tipc_link_create(), and pass
this info on as individual parameters in the call.

This commit introduces this change.

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

net/tipc/link.c

@@ -165,57 +165,64 @@ static u32 link_own_addr(struct tipc_link *l)
 /**
  * tipc_link_create - create a new link
  * @n: pointer to associated node
- * @b: pointer to associated bearer
+ * @if_name: associated interface name
+ * @bearer_id: id (index) of associated bearer
+ * @tolerance: link tolerance to be used by link
+ * @net_plane: network plane (A,B,c..) this link belongs to
+ * @mtu: mtu to be advertised by link
+ * @priority: priority to be used by link
+ * @window: send window to be used by link
+ * @session: session to be used by link
  * @ownnode: identity of own node
- * @peer: identity of peer node
+ * @peer: node id of peer node
  * @maddr: media address to be used
  * @inputq: queue to put messages ready for delivery
  * @namedq: queue to put binding table update messages ready for delivery
  * @link: return value, pointer to put the created link
  *
  * Returns true if link was created, otherwise false
  */
-bool tipc_link_create(struct tipc_node *n, struct tipc_bearer *b, u32 session,
-		      u32 ownnode, u32 peer, struct tipc_media_addr *maddr,
+bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
+		      int tolerance, char net_plane, u32 mtu, int priority,
+		      int window, u32 session, u32 ownnode, u32 peer,
+		      struct tipc_media_addr *maddr,
 		      struct sk_buff_head *inputq, struct sk_buff_head *namedq,
 		      struct tipc_link **link)
 {
 	struct tipc_link *l;
 	struct tipc_msg *hdr;
-	char *if_name;
 
 	l = kzalloc(sizeof(*l), GFP_ATOMIC);
 	if (!l)
 		return false;
 	*link = l;
+	l->pmsg = (struct tipc_msg *)&l->proto_msg;
+	hdr = l->pmsg;
+	tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
+	msg_set_size(hdr, sizeof(l->proto_msg));
+	msg_set_session(hdr, session);
+	msg_set_bearer_id(hdr, l->bearer_id);
 
 	/* Note: peer i/f name is completed by reset/activate message */
-	if_name = strchr(b->name, ':') + 1;
 	sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 		tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
 		if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
+	strcpy((char *)msg_data(hdr), if_name);
 
 	l->addr = peer;
 	l->media_addr = maddr;
 	l->owner = n;
 	l->peer_session = WILDCARD_SESSION;
-	l->bearer_id = b->identity;
-	l->tolerance = b->tolerance;
-	l->net_plane = b->net_plane;
-	l->advertised_mtu = b->mtu;
-	l->mtu = b->mtu;
-	l->priority = b->priority;
-	tipc_link_set_queue_limits(l, b->window);
+	l->bearer_id = bearer_id;
+	l->tolerance = tolerance;
+	l->net_plane = net_plane;
+	l->advertised_mtu = mtu;
+	l->mtu = mtu;
+	l->priority = priority;
+	tipc_link_set_queue_limits(l, window);
 	l->inputq = inputq;
 	l->namedq = namedq;
 	l->state = LINK_RESETTING;
-	l->pmsg = (struct tipc_msg *)&l->proto_msg;
-	hdr = l->pmsg;
-	tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
-	msg_set_size(hdr, sizeof(l->proto_msg));
-	msg_set_session(hdr, session);
-	msg_set_bearer_id(hdr, l->bearer_id);
-	strcpy((char *)msg_data(hdr), if_name);
 	__skb_queue_head_init(&l->transmq);
 	__skb_queue_head_init(&l->backlogq);
 	__skb_queue_head_init(&l->deferdq);

net/tipc/link.h

@@ -205,8 +205,10 @@ struct tipc_link {
 	struct tipc_stats stats;
 };
 
-bool tipc_link_create(struct tipc_node *n, struct tipc_bearer *b, u32 session,
-		      u32 ownnode, u32 peer, struct tipc_media_addr *maddr,
+bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
+		      int tolerance, char net_plane, u32 mtu, int priority,
+		      int window, u32 session, u32 ownnode, u32 peer,
+		      struct tipc_media_addr *maddr,
 		      struct sk_buff_head *inputq, struct sk_buff_head *namedq,
 		      struct tipc_link **link);
 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,

net/tipc/node.c

@@ -493,6 +493,7 @@ void tipc_node_check_dest(struct net *net, u32 onode,
 	bool link_up = false;
 	bool accept_addr = false;
 	bool reset = true;
+	char *if_name;
 
 	*dupl_addr = false;
 	*respond = false;
@@ -579,7 +580,10 @@ void tipc_node_check_dest(struct net *net, u32 onode,
 			pr_warn("Cannot establish 3rd link to %x\n", n->addr);
 			goto exit;
 		}
-		if (!tipc_link_create(n, b, mod(tipc_net(net)->random),
+		if_name = strchr(b->name, ':') + 1;
+		if (!tipc_link_create(n, if_name, b->identity, b->tolerance,
+				      b->net_plane, b->mtu, b->priority,
+				      b->window, mod(tipc_net(net)->random),
 				      tipc_own_addr(net), onode, &le->maddr,
 				      &le->inputq, &n->bclink.namedq, &l)) {
 			*respond = false;