working on DHCP pools

iptools/pool.go

@@ -0,0 +1,69 @@
+package iptools
+
+import (
+	"net/netip"
+	"time"
+)
+
+type Pool struct {
+	Name      string                   `yaml:"name"`
+	Range     *Range                   `yaml:"range"`
+	Expiry    time.Duration            `yaml:"expiry"`
+	Available []LeaseInfo              `yaml:"available"`
+	Active    map[netip.Addr]LeaseInfo `yaml:"active"`
+	Limbo     map[netip.Addr]LeaseInfo `yaml:"limbo"` // leases that are currently being offered
+}
+
+func NewPool(name string, exp time.Duration, r *Range) (*Pool, error) {
+	p := &Pool{
+		Name:      name,
+		Expiry:    exp,
+		Available: enumerateRange(name, r, true),
+	}
+
+	return p, nil
+}
+
+func (p *Pool) Sort() {
+	p.Available = SortLeases(p.Available)
+}
+
+func (p *Pool) IsAddressAvailable() bool {
+	return len(p.Available) > 0
+}
+
+func (p *Pool) Peek(t time.Time, waitFor time.Duration) netip.Addr {
+	lease := p.Available[0]
+	p.Available = p.Available[1:]
+	lease.ResetExpiry(t, waitFor)
+
+	p.Limbo[lease.Addr] = lease
+
+	return lease.Addr
+}
+
+// Update checks expirations on leases, moving any expired leases back
+// to the available pool and removing any limbo leases that are expired.
+func (p *Pool) Update(t time.Time) {
+	for k, v := range p.Active {
+		if v.IsExpired(t) {
+			delete(p.Active, k)
+			v = v.Reset()
+			p.Available = append(p.Available, v)
+		}
+	}
+
+	for k, v := range p.Limbo {
+		if v.IsExpired(t) {
+			delete(p.Limbo, k)
+			v = v.Reset()
+			p.Available = append(p.Available, v)
+		}
+	}
+
+	p.Sort()
+}
+
+func (p *Pool) Renew(lease LeaseInfo, t time.Time) {
+
+}