Ejemplo n.º 1
0
func ruleHandle(rule *Rule, req *nl.NetlinkRequest) error {
	msg := nl.NewRtMsg()
	msg.Family = syscall.AF_INET
	var dstFamily uint8

	var rtAttrs []*nl.RtAttr
	if rule.Dst != nil && rule.Dst.IP != nil {
		dstLen, _ := rule.Dst.Mask.Size()
		msg.Dst_len = uint8(dstLen)
		msg.Family = uint8(nl.GetIPFamily(rule.Dst.IP))
		dstFamily = msg.Family
		var dstData []byte
		if msg.Family == syscall.AF_INET {
			dstData = rule.Dst.IP.To4()
		} else {
			dstData = rule.Dst.IP.To16()
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_DST, dstData))
	}

	if rule.Src != nil && rule.Src.IP != nil {
		msg.Family = uint8(nl.GetIPFamily(rule.Src.IP))
		if dstFamily != 0 && dstFamily != msg.Family {
			return fmt.Errorf("source and destination ip are not the same IP family")
		}
		srcLen, _ := rule.Src.Mask.Size()
		msg.Src_len = uint8(srcLen)
		var srcData []byte
		if msg.Family == syscall.AF_INET {
			srcData = rule.Src.IP.To4()
		} else {
			srcData = rule.Src.IP.To16()
		}
		rtAttrs = append(rtAttrs, nl.NewRtAttr(syscall.RTA_SRC, srcData))
	}

	if rule.Table >= 0 {
		msg.Table = uint8(rule.Table)
		if rule.Table >= 256 {
			msg.Table = syscall.RT_TABLE_UNSPEC
		}
	}

	req.AddData(msg)
	for i := range rtAttrs {
		req.AddData(rtAttrs[i])
	}

	var (
		b      = make([]byte, 4)
		native = nl.NativeEndian()
	)

	if rule.Priority >= 0 {
		native.PutUint32(b, uint32(rule.Priority))
		req.AddData(nl.NewRtAttr(nl.FRA_PRIORITY, b))
	}
	if rule.Mark >= 0 {
		native.PutUint32(b, uint32(rule.Mark))
		req.AddData(nl.NewRtAttr(nl.FRA_FWMARK, b))
	}
	if rule.Mask >= 0 {
		native.PutUint32(b, uint32(rule.Mask))
		req.AddData(nl.NewRtAttr(nl.FRA_FWMASK, b))
	}
	if rule.Flow >= 0 {
		native.PutUint32(b, uint32(rule.Flow))
		req.AddData(nl.NewRtAttr(nl.FRA_FLOW, b))
	}
	if rule.TunID > 0 {
		native.PutUint32(b, uint32(rule.TunID))
		req.AddData(nl.NewRtAttr(nl.FRA_TUN_ID, b))
	}
	if rule.Table >= 256 {
		native.PutUint32(b, uint32(rule.Table))
		req.AddData(nl.NewRtAttr(nl.FRA_TABLE, b))
	}
	if msg.Table > 0 {
		if rule.SuppressPrefixlen >= 0 {
			native.PutUint32(b, uint32(rule.SuppressPrefixlen))
			req.AddData(nl.NewRtAttr(nl.FRA_SUPPRESS_PREFIXLEN, b))
		}
		if rule.SuppressIfgroup >= 0 {
			native.PutUint32(b, uint32(rule.SuppressIfgroup))
			req.AddData(nl.NewRtAttr(nl.FRA_SUPPRESS_IFGROUP, b))
		}
	}
	if rule.IifName != "" {
		req.AddData(nl.NewRtAttr(nl.FRA_IIFNAME, []byte(rule.IifName)))
	}
	if rule.OifName != "" {
		req.AddData(nl.NewRtAttr(nl.FRA_OIFNAME, []byte(rule.OifName)))
	}
	if rule.Goto >= 0 {
		msg.Type = nl.FR_ACT_NOP
		native.PutUint32(b, uint32(rule.Goto))
		req.AddData(nl.NewRtAttr(nl.FRA_GOTO, b))
	}

	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
	return err
}
Ejemplo n.º 2
0
// RouteAdd will add a route to the system.
// Equivalent to: `ip route add $route`
func RouteAdd(route *Route) error {
	req := nl.NewNetlinkRequest(syscall.RTM_NEWROUTE, syscall.NLM_F_CREATE|syscall.NLM_F_EXCL|syscall.NLM_F_ACK)
	return routeHandle(route, req, nl.NewRtMsg())
}