tipc: introduce new socket option TIPC_SOCK_RECVQ_USED

When using TIPC_SOCK_RECVQ_DEPTH for getsockopt(), it returns the
number of buffers in receive socket buffer which is not so helpful
for user space applications.

This commit introduces the new option TIPC_SOCK_RECVQ_USED which
returns the current allocated bytes of the receive socket buffer.
This helps user space applications dimension its buffer usage to
avoid buffer overload issue.

Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/tipc.h b/include/uapi/linux/tipc.h
index 6b2fd4d9655f6949d9c752a4f286ed0834d02f1f..7df026ea6affa62a26c2d588a12d3f8f901bdc2b 100644 (file)
--- a/include/uapi/linux/tipc.h
+++ b/include/uapi/linux/tipc.h
@@ -190,6 +190,7 @@ struct sockaddr_tipc {
 #define TIPC_MCAST_REPLICAST    134     /* Default: TIPC selects. No arg */
 #define TIPC_GROUP_JOIN         135     /* Takes struct tipc_group_req* */
 #define TIPC_GROUP_LEAVE        136     /* No argument */
+#define TIPC_SOCK_RECVQ_USED    137     /* Default: none (read only) */
 
 /*
  * Flag values

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 8ac8ddf1e32419d1751a535f5c6d554a9d43836a..1385207a301f64f99b07e46af6c97394e8ebfda1 100644 (file)
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -3070,6 +3070,9 @@ static int tipc_getsockopt(struct socket *sock, int lvl, int opt,
        case TIPC_SOCK_RECVQ_DEPTH:
                value = skb_queue_len(&sk->sk_receive_queue);
                break;
+       case TIPC_SOCK_RECVQ_USED:
+               value = sk_rmem_alloc_get(sk);
+               break;
        case TIPC_GROUP_JOIN:
                seq.type = 0;
                if (tsk->group)