From 83bbd52cee0d5c4c475df913ecdd7f7e885eb0cf Mon Sep 17 00:00:00 2001
From: Jim Colderwood <jim.colderwood@pnsol.com>
Date: Wed, 10 Apr 2024 16:33:33 +0100
Subject: [PATCH] Route slice

---
 main.go                | 13 ++++------
 ripv2/ripv2.go         | 15 ++++++------
 ripv2/routes/routes.go | 54 ++++++++++++++++++++++++++++++++++++++++++
 ripv2/types.go         |  8 +++----
 4 files changed, 68 insertions(+), 22 deletions(-)
 create mode 100644 ripv2/routes/routes.go

diff --git a/main.go b/main.go
index 05b4006..fd5bd43 100644
--- a/main.go
+++ b/main.go
@@ -6,10 +6,12 @@ import (
 	"net"
 
 	"github.com/crip/ripv2"
+	"github.com/crip/ripv2/routes"
 )
 
 func main() {
 	rip := ripv2.New()
+	routes := routes.New()
 	addr := net.UDPAddr{
 		Port: 520,
 		IP:   net.ParseIP("224.0.0.9"),
@@ -36,14 +38,7 @@ func main() {
 		if err := rip.MParse(&buff, n); err != nil {
 			log.Fatalln(err)
 		}
-
-		/* Just testing the parsing output */
-		for i := 0; i < 24; i++ {
-			if rip.RIP[i].Metric == 0 {
-				break
-			}
-			fmt.Printf("%d\t%s\t%s\t%s\t%d\n", rip.RIP[i].AFI, rip.RIP[i].Addr.String(), rip.RIP[i].Subnet.String(), rip.RIP[i].Nexthop.String(), rip.RIP[i].Metric)
-		}
-		fmt.Println("")
+		routes.ParseRoutes(*UDPAddr, &rip.RIP)
+		fmt.Println(routes)
 	}
 }
diff --git a/ripv2/ripv2.go b/ripv2/ripv2.go
index e4b2977..5e12052 100644
--- a/ripv2/ripv2.go
+++ b/ripv2/ripv2.go
@@ -21,16 +21,15 @@ func (m *Message) MParse(b *[]byte, n int) error {
 		return errors.New("rip table exceeds limit")
 	}
 
-	data := (*b)
-	m.Command = Command(data[0])
-	m.Version = Version(data[1])
+	m.Command = Command((*b)[0])
+	m.Version = Version((*b)[1])
 
 	if m.Version > RIPv2 {
 		return errors.New("unknown version")
 	}
 
 	var indexA, indexB = 4, 25
-	ripentry := data[indexA:indexB]
+	ripentry := (*b)[indexA:indexB]
 	switch m.Command {
 	case REQUEST:
 		return nil
@@ -38,13 +37,13 @@ func (m *Message) MParse(b *[]byte, n int) error {
 		for i := 0; i < (n-4)/20; i++ {
 			m.RIP[i].AFI = binary.BigEndian.Uint16(ripentry[0:2])
 			m.RIP[i].RouteTag = binary.BigEndian.Uint16(ripentry[2:4])
-			m.RIP[i].Addr = net.IPv4(ripentry[4], ripentry[5], ripentry[6], ripentry[7])
-			m.RIP[i].Subnet = net.IPv4Mask(ripentry[8], ripentry[9], ripentry[10], ripentry[11])
-			m.RIP[i].Nexthop = net.IPv4(ripentry[12], ripentry[13], ripentry[14], ripentry[15])
+			m.RIP[i].Addr = binary.BigEndian.Uint32(ripentry[4:8])      //net.IPv4(ripentry[4], ripentry[5], ripentry[6], ripentry[7])
+			m.RIP[i].Subnet = binary.BigEndian.Uint32(ripentry[8:12])   //net.IPv4Mask(ripentry[8], ripentry[9], ripentry[10], ripentry[11])
+			m.RIP[i].Nexthop = binary.BigEndian.Uint32(ripentry[12:16]) //net.IPv4(ripentry[12], ripentry[13], ripentry[14], ripentry[15])
 			m.RIP[i].Metric = binary.BigEndian.Uint32(ripentry[16:20])
 			indexA += 20
 			indexB += 20
-			ripentry = data[indexA:indexB]
+			ripentry = (*b)[indexA:indexB]
 		}
 	default:
 		return errors.New("unknown command type")
diff --git a/ripv2/routes/routes.go b/ripv2/routes/routes.go
new file mode 100644
index 0000000..35894be
--- /dev/null
+++ b/ripv2/routes/routes.go
@@ -0,0 +1,54 @@
+package routes
+
+import (
+	"net"
+	"time"
+
+	"github.com/crip/ripv2"
+)
+
+type Routes []Route
+
+type Route struct {
+	Addr    net.IP
+	Subnet  net.IPMask
+	Nexthop net.IP
+	Metric  uint32
+	TTL     time.Time
+}
+
+func New() Routes {
+	var routes Routes
+	return routes
+}
+
+func (r *Routes) append(route Route) {
+	*r = append(*r, route)
+}
+
+func (r *Routes) ParseRoutes(addr net.UDPAddr, rip *[25]ripv2.RIP) {
+	var route Route
+	for _, rip := range *rip {
+		/* if not af_inet */
+		if rip.AFI != 2 {
+			continue
+		}
+
+		if rip.Addr == 0 || rip.Subnet == 0 {
+			continue
+		}
+
+		route = Route{}
+
+		route.Addr = net.IPv4(byte(rip.Addr>>24), byte(rip.Addr>>16), byte(rip.Addr>>8), byte(rip.Addr))
+		route.Subnet = net.IPv4Mask(byte(rip.Subnet>>24), byte(rip.Subnet>>16), byte(rip.Subnet>>8), byte(rip.Subnet))
+		if rip.Nexthop == 0 {
+			route.Nexthop = addr.IP
+		} else {
+			route.Nexthop = net.IPv4(byte(rip.Nexthop>>24), byte(rip.Nexthop>>16), byte(rip.Nexthop>>8), byte(rip.Nexthop))
+		}
+		route.Metric = rip.Metric
+		route.TTL = time.Now()
+		r.append(route)
+	}
+}
diff --git a/ripv2/types.go b/ripv2/types.go
index fbed13d..f01dc77 100644
--- a/ripv2/types.go
+++ b/ripv2/types.go
@@ -1,7 +1,5 @@
 package ripv2
 
-import "net"
-
 type Command uint8
 type Version uint8
 
@@ -26,8 +24,8 @@ type Message struct {
 type RIP struct {
 	AFI      uint16
 	RouteTag uint16
-	Addr     net.IP
-	Subnet   net.IPMask
-	Nexthop  net.IP
+	Addr     uint32
+	Subnet   uint32
+	Nexthop  uint32
 	Metric   uint32
 }