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path: root/pkg/ipstack/ipstack.go
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Diffstat (limited to 'pkg/ipstack/ipstack.go')
-rw-r--r--pkg/ipstack/ipstack.go191
1 files changed, 103 insertions, 88 deletions
diff --git a/pkg/ipstack/ipstack.go b/pkg/ipstack/ipstack.go
index e4d1651..fb18161 100644
--- a/pkg/ipstack/ipstack.go
+++ b/pkg/ipstack/ipstack.go
@@ -6,6 +6,7 @@ import (
"iptcp/pkg/lnxconfig"
"net"
"net/netip"
+ "time"
)
const (
@@ -20,7 +21,7 @@ type Interface struct {
IpPrefix netip.Prefix
RecvSocket net.Conn
- SocketChannel chan<- bool
+ SocketChannel chan bool
State bool
}
@@ -29,7 +30,7 @@ type Neighbor struct {
UdpAddr netip.AddrPort
SendSocket net.Conn
- SocketChannel chan<- bool
+ SocketChannel chan bool
}
type RIPMessage struct {
@@ -50,8 +51,8 @@ type Hop struct {
}
// GLOBAL VARIABLES (data structures) ------------------------------------------
-var myInterfaces []Interface
-var myNeighbors = make(map[string][]Neighbor)
+var myInterfaces []*Interface
+var myNeighbors = make(map[string][]*Neighbor)
// var myRIPNeighbors = make(map[string]Neighbor)
type HandlerFunc func(int, string, *[]byte) error
@@ -91,6 +92,7 @@ func Initialize(lnxFilePath string) error {
}
// 1) initialize the interfaces on this node here and into the routing table
+ static := false
for _, iface := range lnxConfig.Interfaces {
prefix := netip.PrefixFrom(iface.AssignedIP, iface.AssignedPrefix.Bits())
i := &Interface{
@@ -104,14 +106,18 @@ func Initialize(lnxFilePath string) error {
if err != nil {
return errors.WithMessage(err, "Error creating UDP socket for interface->\t"+iface.Name)
}
- myInterfaces = append(myInterfaces, *i)
-
- // add to routing table
- //ifacePrefix := netip.PrefixFrom(iface.AssignedIP, iface.AssignedPrefix.Bits())
- //routingTable[ifacePrefix] = Hop{STATIC_COST, iface.Name}
+ myInterfaces = append(myInterfaces, i)
+
+ // TODO: (FOR HOSTS ONLY)
+ // add STATIC to routing table
+ if !static {
+ ifacePrefix := netip.MustParsePrefix("0.0.0.0/0")
+ routingTable[ifacePrefix] = Hop{STATIC_COST, iface.Name}
+ static = true
+ }
}
- // 2) initialize the neighbors connected to the node
+ // 2) initialize the neighbors connected to the node and into the routing table
for _, neighbor := range lnxConfig.Neighbors {
n := &Neighbor{
VipAddr: neighbor.DestAddr,
@@ -122,7 +128,7 @@ func Initialize(lnxFilePath string) error {
if err != nil {
return errors.WithMessage(err, "Error creating UDP socket for neighbor->\t"+neighbor.DestAddr.String())
}
- myNeighbors[neighbor.InterfaceName] = append(myNeighbors[neighbor.InterfaceName], *n)
+ myNeighbors[neighbor.InterfaceName] = append(myNeighbors[neighbor.InterfaceName], n)
// add to routing table
neighborPrefix := netip.PrefixFrom(neighbor.DestAddr, 24)
@@ -132,84 +138,51 @@ func Initialize(lnxFilePath string) error {
return nil
}
-/*
-
-func ListerToInterfaces() {
- for _, iface := range myInterfaces {
- go RecvIp(iface)
- }
-}
-
-func RecvIp(iface Interface) error {
+func InterfaceListenerRoutine(iface Interface, signal <-chan bool) {
+ isDown := false
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
+ select {
+ case open, sig := <-signal:
+ if !open {
+ fmt.Println("channel closed, exiting")
+ return
+ }
+ fmt.Println("received SIGNAL with value", sig)
+ if sig {
+ isDown = <-signal
+ }
+ default:
+ if isDown {
+ continue
+ }
+ fmt.Println("no activity, actively listening on", iface.Name)
+ // TODO: remove these training wheels
+ time.Sleep(1 * time.Millisecond)
}
+ }
+}
- 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)
- }
- }
+// When an interface goes up, we need to start it's go routine that listens
+func InterfaceUp(iface *Interface) {
+ iface.SocketChannel = make(chan bool)
+ iface.State = true
+ go func() {
+ InterfaceListenerRoutine(*iface, iface.SocketChannel)
+ }()
+}
- // check forwarding table
+func InterfaceDown(iface *Interface) {
+ iface.SocketChannel <- true
+ iface.State = false
+}
- }
+/*
+func ListerToInterfaces() {
+ for _, iface := range myInterfaces {
+ go RecvIp(iface)
}
}
-
func ValidateChecksum(b []byte, fromHeader uint16) uint16 {
checksum := header.Checksum(b, fromHeader)
@@ -323,25 +296,67 @@ func GetNeighbors() []netip.Addr {
}
*/
-func PrintInterfaces() {
+func GetInterfaceByName(ifaceName string) (*Interface, error) {
for _, iface := range myInterfaces {
- fmt.Printf("%s\t%s\t%t\n", iface.Name, iface.IpPrefix.String(), iface.State)
+ if iface.Name == ifaceName {
+ return iface, nil
+ }
}
+
+ return nil, errors.Errorf("No interface with name %s", ifaceName)
}
-func PrintNeighbors() {
+func SprintInterfaces() string {
+ buf := ""
+ for _, iface := range myInterfaces {
+ buf += fmt.Sprintf("%s\t%s\t%t\n", iface.Name, iface.IpPrefix.String(), iface.State)
+ }
+ return buf
+}
+
+func SprintNeighbors() string {
+ buf := ""
for ifaceName, neighbor := range myNeighbors {
for _, n := range neighbor {
- fmt.Printf("%s\t%s\t%s\n", ifaceName, n.UdpAddr.String(), n.VipAddr.String())
+ buf += fmt.Sprintf("%s\t%s\t%s\n", ifaceName, n.UdpAddr.String(), n.VipAddr.String())
}
}
+ return buf
}
func SprintRoutingTable() string {
- message := ""
+ buf := ""
for prefix, hop := range routingTable {
- message += fmt.Sprintf("%s\t%s\t%d\n", prefix.String(), hop.VipAsStr, hop.Cost)
+ buf += fmt.Sprintf("%s\t%s\t%d\n", prefix.String(), hop.VipAsStr, hop.Cost)
+ }
+ return buf
+}
+
+func DebugNeighbors() {
+ for ifaceName, neighbor := range myNeighbors {
+ for _, n := range neighbor {
+ fmt.Printf("%s\t%s\t%s\t%s\n", ifaceName, n.UdpAddr.String(), n.VipAddr.String(), n.SendSocket)
+ }
+ }
+}
+
+func CleanUp() {
+ fmt.Print("Cleaning up...\n")
+ // go through the interfaces, pop thread & close the UDP FDs
+ for _, iface := range myInterfaces {
+ if iface.SocketChannel != nil {
+ close(iface.SocketChannel)
+ }
+ iface.RecvSocket.Close()
}
- return message
+ // go through the neighbors, pop thread & close the UDP FDs
+ for _, neighbor := range myNeighbors {
+ for _, n := range neighbor {
+ if n.SocketChannel != nil {
+ close(n.SocketChannel)
+ }
+ n.SendSocket.Close()
+ }
+ }
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-10-06 16:55:16 +0000