func()

in pkg/skoop/plugin/simple.go [58:125]
62 lines of code
10 McCabe index (conditional complexity)

func (p *simpleVEthPod) Send(dst model.Endpoint, protocol model.Protocol) ([]model.Transmission, error) {
	err := p.assert()
	if err != nil {
		return nil, err
	}

	pkt := &model.Packet{
		Dst:      net.ParseIP(dst.IP),
		Dport:    dst.Port,
		Protocol: protocol,
	}

	addr, dstRoute, err := p.podInfo.NetNS.Router.RouteSrc(pkt, "", "")
	if err != nil {
		if err == netstack.ErrNoRouteToHost {
			p.netNode.AddSuspicion(model.SuspicionLevelFatal, fmt.Sprintf("no route to host: %v", dst))
		}
		return nil, &assertions.CannotBuildTransmissionError{
			SrcNode: p.netNode,
			Err:     fmt.Errorf("no route to host: %v", err)}
	}
	neigh, err := p.podInfo.NetNS.Neighbour.ProbeRouteNeigh(dstRoute, pkt.Dst)
	if err != nil {
		return nil, &assertions.CannotBuildTransmissionError{
			SrcNode: p.netNode,
			Err:     fmt.Errorf("pod neigh system probe failed: %v", err),
		}
	}
	if neigh != nil && (neigh.State == netstack.NudFailed || neigh.State == netstack.NudIncomplete) {
		if dstRoute.Gw == nil {
			p.netNode.AddSuspicion(model.SuspicionLevelCritical, fmt.Sprintf("dst: %v ARP resolve failed.", pkt.Dst.String()))
		} else {
			p.netNode.AddSuspicion(model.SuspicionLevelCritical, fmt.Sprintf("dst: %v route's gateway: %v ARP resolve failed.", pkt.Dst.String(), dstRoute.Gw.String()))
		}
	}

	pkt.Src = net.ParseIP(addr)

	iface, _ := lo.Find(p.podInfo.NetNS.Interfaces, func(i netstack.Interface) bool { return i.Name == "eth0" })
	link := &model.Link{
		Type:   model.LinkVeth,
		Source: p.netNode,
		Packet: pkt,
		SourceAttribute: model.VEthLinkAttribute{
			SimpleLinkAttribute: model.SimpleLinkAttribute{
				Interface: "eth0",
				IP:        addr,
			},
			PeerIndex: iface.PeerIndex,
		},
	}
	err = p.net.AssertRoute(assertions.RouteAssertion{Dev: utils.ToPointer("eth0")}, *pkt, "", "")
	if err != nil {
		return nil, err
	}

	p.netNode.DoAction(model.ActionSend([]*model.Link{link}))

	return []model.Transmission{
		{
			NextHop: model.Hop{
				Type: model.NetNodeTypeNode,
				ID:   p.podInfo.NodeName,
			},
			Link: link,
		},
	}, nil
}