SDP_RX_SIZE
.cap.max_recv_wr = SDP_RX_SIZE,
rx_req = ssk->rx_ring.buffer + (id & (SDP_RX_SIZE - 1));
if (posted >= SDP_RX_SIZE)
rx_req = &ssk->rx_ring.buffer[id & (SDP_RX_SIZE - 1)];
.cqe = SDP_RX_SIZE,
ssk->rx_ring.buffer = malloc(sizeof(*ssk->rx_ring.buffer) * SDP_RX_SIZE,