From af7c5d500b76a6f2db790a1a8e0480f370da81ce Mon Sep 17 00:00:00 2001
From: Trygve Laugstøl <trygvis@inamo.no>
Date: Tue, 29 Oct 2024 21:17:53 +0100
Subject: utils: networks

---
 utils/ipam/ipam.go | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 120 insertions(+)
 create mode 100644 utils/ipam/ipam.go

(limited to 'utils/ipam')

diff --git a/utils/ipam/ipam.go b/utils/ipam/ipam.go
new file mode 100644
index 0000000..faec6e7
--- /dev/null
+++ b/utils/ipam/ipam.go
@@ -0,0 +1,120 @@
+package ipam
+
+import (
+	"cmp"
+	"fmt"
+	"log"
+	"net/netip"
+	"utils/ipam/yaml_model"
+)
+
+func LoadIpam(bs []byte) (*Ipam, error) {
+	parsed, err := yaml_model.Parse(bs)
+	if err != nil {
+		return nil, err
+	}
+
+	ipam_, err := processNetworks(parsed.Ipam6.Networks)
+	if err != nil {
+		return nil, err
+	}
+
+	ipam_.ResolveParents()
+
+	return ipam_, nil
+}
+
+type Ipam struct {
+	Networks []*Network
+}
+
+func contains(a, b netip.Prefix) bool {
+	return b.Bits() > a.Bits() && b.Overlaps(a)
+}
+
+func (ipam *Ipam) ResolveParents() {
+	for _, n := range ipam.Networks {
+		log.Printf("network %s/%s", n.Name, n.Prefix)
+		for _, p := range ipam.Networks {
+			if n == p {
+				continue
+			}
+			log.Printf(" candidate %s/%s", p.Name, p.Prefix)
+			if contains(p.Prefix, n.Prefix) {
+				if n.Parent == nil {
+					log.Printf(" found parent %s/%s", p.Name, p.Prefix)
+					n.Parent = p
+				} else {
+					if n.Parent.Prefix.Bits() < p.Prefix.Bits() {
+						log.Printf(" found better parent %s/%s", p.Name, p.Prefix)
+						n.Parent = p
+					}
+				}
+			}
+		}
+	}
+
+	return
+}
+
+func (ipam *Ipam) FindRoots() []*Network {
+	var ns []*Network
+
+	for _, n := range ipam.Networks {
+		if n.Parent == nil {
+			ns = append(ns, n)
+		}
+	}
+
+	return ns
+}
+
+type Network struct {
+	Name   string
+	Parent *Network
+	Prefix netip.Prefix
+	hosts  []networkHost
+}
+
+func CompareNetwork(a, b *Network) int {
+	return cmp.Compare(a.Name, b.Name)
+}
+
+func (n *Network) Compare(other *Network) int {
+	return cmp.Compare(n.Name, other.Name)
+}
+
+type networkHost struct {
+	name    string
+	address netip.Addr
+}
+
+func processNetworks(networks map[string]yaml_model.Network6Yaml) (*Ipam, error) {
+	var ns []*Network
+
+	for name, net := range networks {
+		log.Printf("Processing net %v\n", name)
+		prefix, err := netip.ParsePrefix(net.Range)
+		if err != nil {
+			return nil, fmt.Errorf("error parsing net range: %v", err)
+		}
+		log.Printf("prefix: %s", prefix.String())
+
+		n := Network{Name: name, Prefix: prefix}
+		for hostname, a := range net.Hosts {
+			addr, err := netip.ParseAddr(a)
+			if err != nil {
+				return nil, fmt.Errorf("network: %s, unable to parse host address %s", n.Name, a)
+			}
+
+			n.hosts = append(n.hosts, networkHost{
+				name:    hostname,
+				address: addr,
+			})
+		}
+
+		ns = append(ns, &n)
+	}
+
+	return &Ipam{Networks: ns}, nil
+}
-- 
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