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Diffstat (limited to 'pkg/protocol.go')
-rw-r--r--pkg/protocol.go300
1 files changed, 0 insertions, 300 deletions
diff --git a/pkg/protocol.go b/pkg/protocol.go
deleted file mode 100644
index 63951d6..0000000
--- a/pkg/protocol.go
+++ /dev/null
@@ -1,300 +0,0 @@
-package protocol
-
-import (
- "net"
- "net/netip"
- "fmt"
- "os"
- "bufio"
- "time"
- "github.com/pkg/errors"
- ipv4header "github.com/brown-csci1680/iptcp-headers"
- "github.com/google/netstack/tcpip/header"
- "github.com/brown-csci1680/ipstack-utils"
-)
-
-const (
- MAX_IP_PACKET_SIZE = 1400
-)
-
-type Interface struct {
- Name string
- AssignedIP netip.Addr
- AssignedPrefix netip.Prefix
-
- UDPAddr netip.AddrPort
- State uint8_t
- neighbors map[netip.AddrPort]netip.AddrPort
-}
-
-// type Host struct {
-// Interface Interface
-// Neighbors []Neighbor
-// }
-
-// type Router struct {
-// Interfaces []Interface
-// Neighbors []Neighbor
-// RIPNeighbors []Neighbor
-// }
-
-
-type Neighbor struct{
- DestAddr netip.Addr
- UDPAddr netip.AddrPort
-
- InterfaceName string
-}
-
-type RIPMessage struct {
- command uint8_t;
- numEntries uint8_t;
- entries []RIPEntry;
-}
-
-type RIPEntry struct {
- addr netip.Addr;
- cost uint16_t;
- mask netip.Prefix;
-}
-
-type RoutingTable interface {
- Initialize(config IpConfig) (error)
- AddRoute(dest Address, cost uint16_t, mask netip.Prefix) (error)
- RemoveRoute(dest Address) (error)
- GetRoute(dest Address) (Routing, error)
-}
-
-
-myInterfaces := make([]Interface);
-myNeighbors := make(map[string]Neighbor)
-myRIPNeighbors := make(map[string]Neighbor)
-protocolHandlers := make(map[uint16]HandlerFunc)
-routingTable := RoutingTable{}
-// routingTable := make(map[Address]Routing)
-
-func Initialize(config IpConfig) (error) {
- if len(os.Args) != 2 {
- fmt.Printf("Usage: %s <configFile>\n", os.Args[0])
- os.Exit(1)
- }
- fileName := os.Args[1]
-
- // Parse the file
- lnxConfig, err := lnxconfig.ParseConfig(fileName)
- if err != nil {
- panic(err)
- }
-
- // populate routing table???
- for _, iface := range lnxConfig.Interfaces {
- myInterfaces = append(myInterfaces, Interface{iface.Name, iface.AssignedIP, iface.AssignedPrefix, iface.UDPAddr, 0})
- }
-
- for _, neighbor := range lnxConfig.Neighbors {
- myNeighbors[neighbor.DestAddr.String()] = Neighbor{neighbor.DestAddr, neighbor.UDPAddr, neighbor.InterfaceName}
- }
-
- // add RIP neighbors
- for _, neighbor := range lnxConfig.RipNeighbors {
- myRIPNeighbors[neighbor.DestAddr.String()] = Neighbor{neighbor.DestAddr, neighbor.UDPAddr, neighbor.InterfaceName}
- }
- // call routingTable.Initialize(config)
- // create new routing table
- routingTable.Initialize(config)
-
-}
-
-func ListerToInterfaces() {
- for _, iface := range myInterfaces {
- go RecvIp(iface)
- }
-}
-
-func RecvIp(iface Interface) (error) {
- for {
- buffer := make([]byte, MAX_IP_PACKET_SIZE)
- _, sourceAddr, err := iface.udp.ReadFrom(buffer)
- if err != nil {
- log.Panicln("Error reading from UDP socket ", err)
- }
-
- hdr, err := ipv4header.ParseHeader(buffer)
-
- if err != nil {
- fmt.Println("Error parsing header", err)
- continue
- }
-
- headerSize := hdr.Len
- headerBytes := buffer[:headerSize]
-
- checksumFromHeader := uint16(hdr.Checksum)
- computedChecksum := ValidateChecksum(headerBytes, checksumFromHeader)
-
- var checksumState string
- if computedChecksum == checksumFromHeader {
- checksumState = "OK"
- } else {
- checksumState = "FAIL"
- continue
- }
-
- // check ttl
- ttl := data[8]
- if ttl == 0 {
- fmt.Println("TTL is 0")
- continue
- }
-
-
- destAddr := netip.AddrFrom(data[16:20])
- protocolNum := data[9]
-
- if destAddr == iface.addr {
- // send to handler
- protocolHandlers[protocolNum](data)
- // message := buffer[headerSize:]
-
- // fmt.Printf("Received IP packet from %s\nHeader: %v\nChecksum: %s\nMessage: %s\n",
- // sourceAddr.String(), hdr, checksumState, string(message))
- } else {
- // decrement ttl and update checksum
- data[8] = ttl - 1
- data[10] = 0
- data[11] = 0
- newChecksum := int(ComputeChecksum(data[:headerSize]))
- data[10] = newChecksum >> 8
- data[11] = newChecksum & 0xff
-
- // check neighbors
- for _, neighbor := range iface.neighbors {
- if neighbor == destAddr {
- // send to neighbor
- // SendIp(destAddr, protocolNum, data)
- }
- }
-
- // check forwarding table
-
- }
-
- }
-}
-
-func ValidateChecksum(b []byte, fromHeader uint16) uint16 {
- checksum := header.Checksum(b, fromHeader)
-
- return checksum
-}
-
-func SendIp(dst netip.Addr, port uint16, protocolNum uint16, data []byte, iface Interface) (error) {
- bindLocalAddr, err := net.ResolveUDPAddr("udp4", iface.UDPAddr.String())
- if err != nil {
- log.Panicln("Error resolving address: ", err)
- }
-
- addrString := fmt.Sprintf("%s:%s", dst, port)
- remoteAddr, err := net.ResolveUDPAddr("udp4", addrString)
- if err != nil {
- log.Panicln("Error resolving address: ", err)
- }
-
- fmt.Printf("Sending to %s:%d\n",
- remoteAddr.IP.String(), remoteAddr.Port)
-
- // Bind on the local UDP port: this sets the source port
- // and creates a conn
- conn, err := net.ListenUDP("udp4", bindLocalAddr)
- if err != nil {
- log.Panicln("Dial: ", err)
- }
-
- message := data[20:]
- hdr := ipv4header.IPv4Header{
- Version: data[0] >> 4,
- Len: 20, // Header length is always 20 when no IP options
- TOS: data[1],
- TotalLen: ipv4header.HeaderLen + len(message),
- ID: data[4],
- Flags: data[6] >> 5,
- FragOff: data[6] & 0x1f,
- TTL: data[8],
- Protocol: data[9],
- Checksum: 0, // Should be 0 until checksum is computed
- Src: netip.MustParseAddr(iface.addr.String()),
- Dst: netip.MustParseAddr(dst.String()),
- Options: []byte{},
- }
-
- headerBytes, err := hdr.Marshal()
- if err != nil {
- log.Fatalln("Error marshalling header: ", err)
- }
-
- hdr.Checksum = int(ComputeChecksum(headerBytes))
-
- headerBytes, err = hdr.Marshal()
- if err != nil {
- log.Fatalln("Error marshalling header: ", err)
- }
-
- bytesToSend := make([]byte, 0, len(headerBytes)+len(message))
- bytesToSend = append(bytesToSend, headerBytes...)
- bytesToSend = append(bytesToSend, []byte(message)...)
-
- // Send the message to the "link-layer" addr:port on UDP
- bytesWritten, err := conn.WriteToUDP(bytesToSend, remoteAddr)
- if err != nil {
- log.Panicln("Error writing to socket: ", err)
- }
- fmt.Printf("Sent %d bytes\n", bytesWritten)
-}
-
-func ComputeChecksum(b []byte) uint16 {
- checksum := header.Checksum(b, 0)
- checksumInv := checksum ^ 0xffff
-
- return checksumInv
-}
-
-func ForwardIP(data []byte) (error) {
-}
-
-type HandlerFunc = func help(*Packet, []interface{}) (error) {
-
- // do smth with packet
-}
-
-func AddRecvHandler(protocolNum uint8, callbackFunc HandlerFunc) (error) {
- if protocolHandlers[protocolNum] != nil {
- fmt.Printf("Warning: Handler for protocol %d already exists", protocolNum)
- }
- protocolHandlers[protocolNum] = callbackFunc
- return nil
-}
-
-func RemoveRecvHandler(protocolNum uint8) (error) {
- // consider error
- if protocolHandlers[protocolNum] == nil {
- return errors.Errorf("No handler for protocol %d", protocolNum)
- }
- delete(protocolHandlers, protocolNum)
- return nil
-}
-
-func PrintNeighbors() {
- for _, iface := range myNeighbors {
- fmt.Printf("%s\n", iface.addr.String())
- }
-}
-
-func PrintInterfaces() {
- for _, iface := range myInterfaces {
- fmt.Printf("%s\n", iface.addr.String())
- }
-}
-func GetNeighbors() ([]netip.Addr) {
- return myNeighbors
-}
-
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-10-06 19:21:30 +0000