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>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 8ac8ddf1e324..1385207a301f 100644
--- 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)