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log packet information

This commit is contained in:
Johannes Kimmel 2021-12-14 10:28:17 +01:00
parent ce4c21154b
commit 3983700788
2 changed files with 16 additions and 11 deletions
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8
main.go
View File

@ -42,13 +42,17 @@ func run(opt options) error {
buf := [4096]byte{} buf := [4096]byte{}
var s tlv.PacketDecoder var s tlv.PacketDecoder
for { for {
b, src, ifindex, err := conn.ReadFrom(buf[:]) b, src, rcm, err := conn.ReadFrom(buf[:])
if err != nil { if err != nil {
fmt.Println("Skipping packet:", err) fmt.Println("Skipping packet:", err)
continue continue
} }
s.Reset(b, src, ifindex) fmt.Print("\x1B[1m")
fmt.Printf("Packet size %4d %s", len(b), rcm)
fmt.Println("\x1B[0m")
s.Reset(b, src, rcm.IfIndex)
for s.Scan() { for s.Scan() {
switch t := s.TLV().(type) { switch t := s.TLV().(type) {
case tlv.NextHop: case tlv.NextHop:

19
packet/packet.go
View File

@ -48,15 +48,16 @@ func (c Conn) JoinGroup(ifname string, addr string) error {
return c.v6pc.JoinGroup(ifi, &net.UDPAddr{IP: ip.IPAddr().IP}) return c.v6pc.JoinGroup(ifi, &net.UDPAddr{IP: ip.IPAddr().IP})
} }
func (c Conn) ReadFrom(b []byte) (body []byte, src netaddr.IP, ifindex int, err error) { func (c Conn) ReadFrom(b []byte) (body []byte, src netaddr.IP, rcm *ipv6.ControlMessage, err error) {
n, rcm, _, err := c.v6pc.ReadFrom(b) var n int
n, rcm, _, err = c.v6pc.ReadFrom(b)
if err != nil { if err != nil {
return nil, netaddr.IP{}, 0, err return nil, netaddr.IP{}, nil, err
} }
b = b[:n] b = b[:n]
if len(b) < BabelPacketHeaderSize { if len(b) < BabelPacketHeaderSize {
return nil, netaddr.IP{}, 0, fmt.Errorf("Packet too short: %d", len(b)) return nil, netaddr.IP{}, nil, fmt.Errorf("Packet too short: %d", len(b))
} }
magic := b[0] magic := b[0]
@ -65,22 +66,22 @@ func (c Conn) ReadFrom(b []byte) (body []byte, src netaddr.IP, ifindex int, err
b = b[4:] b = b[4:]
if magic != BabelMagic { if magic != BabelMagic {
return nil, netaddr.IP{}, 0, fmt.Errorf("Invalid magic number %d", magic) return nil, netaddr.IP{}, nil, fmt.Errorf("Invalid magic number %d", magic)
} }
if version != BabelVersion { if version != BabelVersion {
return nil, netaddr.IP{}, 0, fmt.Errorf("Unsupported version number %d", version) return nil, netaddr.IP{}, nil, fmt.Errorf("Unsupported version number %d", version)
} }
if int(length) > len(b) { if int(length) > len(b) {
return nil, netaddr.IP{}, 0, fmt.Errorf("Invalid length for packet of size %d: %d", n, length) return nil, netaddr.IP{}, nil, fmt.Errorf("Invalid length for packet of size %d: %d", n, length)
} }
var ok bool var ok bool
src, ok = netaddr.FromStdIPRaw(rcm.Src) src, ok = netaddr.FromStdIPRaw(rcm.Src)
if !ok { if !ok {
return nil, netaddr.IP{}, 0, fmt.Errorf("Invalid src address %q", rcm.Src) return nil, netaddr.IP{}, nil, fmt.Errorf("Invalid src address %q", rcm.Src)
} }
return b, src, rcm.IfIndex, err return b, src, rcm, err
} }