RDMACMEVENTCONNECTREQUEST

RDMACMEVENTCONNECTREQUEST, or RDMA_CM_EVENT_CONNECT_REQUEST, is an event type in the RDMA Connection Manager (RDMA-CM) API. It signals the arrival of an incoming connection request on a listening RDMA CM identifier and marks the first step in establishing a new RDMA connection between a client and server. This event is part of the kernel/user-space interface used by applications that implement RDMA communication over InfiniBand or RDMA over Converged Ethernet.

When a remote peer initiates a connection to a listening CM ID, the RDMA CM posts a RDMA_CM_EVENT_CONNECT_REQUEST to the application's event channel. The event provides access to the new connection identifier (rdma_cm_id) representing the client-side connection, and may carry optional private data exchanged during the handshake. The receiving application uses this event to decide whether to accept or reject the connection.

To proceed after receiving the event, the application typically fills a rdma_conn_param structure with desired connection parameters and calls rdma_accept on the new rdma_cm_id to establish the connection. Alternatively, the application can reject the request or perform additional verification before deciding. After handling the event, the application must acknowledge it with rdma_ack_cm_event to free resources associated with the event.

On successful acceptance, the connection progresses toward established state, and subsequent events such as RDMA_CM_EVENT_ESTABLISHED will be reported as the two endpoints complete the handshake and set up their QPs. RDMACMEVENTCONNECTREQUEST is therefore the entry point for server-side connection setup in RDMA-CM.