fn handle_state_change()

in nfm-common/src/sock_ops_handler.rs [172:221]

• 38 lines of code
• 7 McCabe index (conditional complexity)

    fn handle_state_change(&mut self) -> SockOpsResult {
        self.counters.state_change_events += 1;

        // This callback is called before the state is actually changed, so the arguments need to
        // be used instead of the ctx.state.
        let old_state = self.ctx.arg(0);
        let new_state = self.ctx.arg(1);
        let mut new_flags = SockStateFlags::empty();

        match self.get_or_add_sock_stats() {
            Ok(stats_raw) => unsafe {
                let sock_stats = &mut *stats_raw;

                if new_state == BPF_TCP_ESTABLISHED {
                    new_flags |= SockStateFlags::ENTERED_ESTABLISH;
                    sock_stats.connect_end_us = self.now_us;

                    if old_state == BPF_TCP_SYN_SENT {
                        self.counters.active_established_events += 1;
                        sock_stats.connect_successes += 1;
                    }
                } else if !matches!(new_state, BPF_TCP_SYN_SENT | BPF_TCP_SYN_RECV) {
                    new_flags |= SockStateFlags::STARTED_CLOSURE;

                    if matches!(old_state, BPF_TCP_SYN_SENT | BPF_TCP_SYN_RECV) {
                        new_flags |= SockStateFlags::TERMINATED_FROM_SYN;
                    }

                    if new_state == BPF_TCP_CLOSE {
                        new_flags |= SockStateFlags::CLOSED;

                        // Store some final stats on connection close.
                        let event_stats = nfm_get_sock_ops_stats(self.ctx);
                        sock_stats.bytes_received = event_stats.bytes_received;
                        sock_stats.bytes_delivered = event_stats.bytes_acked;
                        sock_stats.segments_received = event_stats.segments_received;
                        sock_stats.segments_delivered = event_stats.segments_delivered;

                        if old_state == BPF_TCP_ESTABLISHED {
                            new_flags |= SockStateFlags::TERMINATED_FROM_EST;
                        }
                    }
                }

                sock_stats.state_flags.insert(new_flags);
                Ok(())
            },
            Err(e) => Err(e),
        }
    }