tipc: let broadcast packet reception use new link receive function

The code path for receiving broadcast packets is currently distinct
from the unicast path. This leads to unnecessary code and data
duplication, something that can be avoided with some effort.

We now introduce separate per-peer tipc_link instances for handling
broadcast packet reception. Each receive link keeps a pointer to the
common, single, broadcast link instance, and can hence handle release
and retransmission of send buffers as if they belonged to the own
instance.

Furthermore, we let each unicast link instance keep a reference to both
the pertaining broadcast receive link, and to the common send link.
This makes it possible for the unicast links to easily access data for
broadcast link synchronization, as well as for carrying acknowledges for
received broadcast packets.

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>

1 files changed, 32 insertions, 11 deletions

diff --git a/net/tipc/link.h b/net/tipc/link.h
index d23329db4b25..28a6396b6d31 100644
--- a/net/tipc/link.h
+++ b/net/tipc/link.h
@@ -66,7 +66,8 @@ enum {
  */
 enum {
         TIPC_LINK_UP_EVT       = 1,
-        TIPC_LINK_DOWN_EVT     = (1 << 1)
+        TIPC_LINK_DOWN_EVT     = (1 << 1),
+        TIPC_LINK_SND_BC_ACK   = (1 << 2)
 };
 
 /* Starting value for maximum packet size negotiation on unicast links
@@ -209,6 +210,10 @@ struct tipc_link {
         /* Broadcast */
         u16 ackers;
         u16 acked;
+        struct tipc_link *bc_rcvlink;
+        struct tipc_link *bc_sndlink;
+        int nack_state;
+        bool bc_peer_is_up;
 
         /* Statistics */
         struct tipc_stats stats;
@@ -217,17 +222,21 @@ struct tipc_link {
 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,
-                      u16 peer_caps, struct tipc_media_addr *maddr,
-                      struct sk_buff_head *inputq, struct sk_buff_head *namedq,
+                      u16 peer_caps,
+                      struct tipc_media_addr *maddr,
+                      struct tipc_link *bc_sndlink,
+                      struct tipc_link *bc_rcvlink,
+                      struct sk_buff_head *inputq,
+                      struct sk_buff_head *namedq,
                       struct tipc_link **link);
-bool tipc_link_bc_create(struct tipc_node *n, int mtu, int window,
-                         u16 peer_caps, struct sk_buff_head *inputq,
+bool tipc_link_bc_create(struct tipc_node *n, u32 ownnode, u32 peer,
+                         int mtu, int window, u16 peer_caps,
+                         struct sk_buff_head *inputq,
                          struct sk_buff_head *namedq,
+                         struct tipc_link *bc_sndlink,
                          struct tipc_link **link);
 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
                            int mtyp, struct sk_buff_head *xmitq);
-void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
-                                    struct sk_buff_head *xmitq);
 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq);
 int tipc_link_fsm_evt(struct tipc_link *l, int evt);
 void tipc_link_reset_fragments(struct tipc_link *l_ptr);
@@ -264,9 +273,21 @@ int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]);
 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq);
 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
                   struct sk_buff_head *xmitq);
-void tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq);
-void tipc_link_add_bc_peer(struct tipc_link *l);
-void tipc_link_remove_bc_peer(struct tipc_link *l);
+int tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq);
+void tipc_link_add_bc_peer(struct tipc_link *snd_l,
+                           struct tipc_link *uc_l,
+                           struct sk_buff_head *xmitq);
+void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
+                              struct tipc_link *rcv_l,
+                              struct sk_buff_head *xmitq);
 int tipc_link_bc_peers(struct tipc_link *l);
-
+void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
+                          struct sk_buff_head *xmitq);
+void tipc_link_build_bc_sync_msg(struct tipc_link *l,
+                                 struct sk_buff_head *xmitq);
+void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr);
+void tipc_link_bc_sync_rcv(struct tipc_link *l,   struct tipc_msg *hdr,
+                           struct sk_buff_head *xmitq);
+int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
+                          struct sk_buff_head *xmitq);
 #endif