add all files from Hong

plugins/range/storage.go

@@ -0,0 +1,93 @@
+// Copyright 2018-present the CoreDHCP Authors. All rights reserved
+// This source code is licensed under the MIT license found in the
+// LICENSE file in the root directory of this source tree.
+
+package rangeplugin
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"net"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+func loadDB(path string) (*sql.DB, error) {
+	db, err := sql.Open("sqlite3", fmt.Sprintf("file:%s", path))
+	if err != nil {
+		return nil, fmt.Errorf("failed to open database (%T): %w", err, err)
+	}
+	if _, err := db.Exec("create table if not exists leases4 (mac string not null, ip string not null, static bool, expiry int, hostname string not null, primary key (mac, ip))"); err != nil {
+		return nil, fmt.Errorf("table creation failed: %w", err)
+	}
+	return db, nil
+}
+
+// loadRecords loads the DHCPv6/v4 Records global map with records stored on
+// the specified file. The records have to be one per line, a mac address and an
+// IP address.
+func loadRecords(db *sql.DB) (map[string]*Record, error) {
+	rows, err := db.Query("select mac, ip, static, expiry, hostname from leases4")
+	if err != nil {
+		return nil, fmt.Errorf("failed to query leases database: %w", err)
+	}
+	defer rows.Close()
+	var (
+		mac, ip, hostname string
+		static            bool
+		expiry            int
+		records           = make(map[string]*Record)
+	)
+	for rows.Next() {
+		if err := rows.Scan(&mac, &ip, &static, &expiry, &hostname); err != nil {
+			return nil, fmt.Errorf("failed to scan row: %w", err)
+		}
+		hwaddr, err := net.ParseMAC(mac)
+		if err != nil {
+			return nil, fmt.Errorf("malformed hardware address: %s", mac)
+		}
+		ipaddr := net.ParseIP(ip)
+		if ipaddr.To4() == nil {
+			return nil, fmt.Errorf("expected an IPv4 address, got: %v", ipaddr)
+		}
+		records[hwaddr.String()] = &Record{IP: ipaddr, Static: static, Expires: expiry, Hostname: hostname}
+	}
+	if err := rows.Err(); err != nil {
+		return nil, fmt.Errorf("failed lease database row scanning: %w", err)
+	}
+	return records, nil
+}
+
+// saveIPAddress writes out a lease to storage
+func (p *PluginState) saveIPAddress(mac net.HardwareAddr, record *Record) error {
+	stmt, err := p.leasedb.Prepare(`insert or replace into leases4(mac, ip, static, expiry, hostname) values (?, ?, ?, ?, ?)`)
+	if err != nil {
+		return fmt.Errorf("statement preparation failed: %w", err)
+	}
+	defer stmt.Close()
+	if _, err := stmt.Exec(
+		mac.String(),
+		record.IP.String(),
+		record.Static,
+		record.Expires,
+		record.Hostname,
+	); err != nil {
+		return fmt.Errorf("record insert/update failed: %w", err)
+	}
+	return nil
+}
+
+// registerBackingDB installs a database connection string as the backing store for leases
+func (p *PluginState) registerBackingDB(filename string) error {
+	if p.leasedb != nil {
+		return errors.New("cannot swap out a lease database while running")
+	}
+	// We never close this, but that's ok because plugins are never stopped/unregistered
+	newLeaseDB, err := loadDB(filename)
+	if err != nil {
+		return fmt.Errorf("failed to open lease database %s: %w", filename, err)
+	}
+	p.leasedb = newLeaseDB
+	return nil
+}