add router component

router/router.go

@@ -0,0 +1,265 @@
+package router
+
+import (
+	"bufio"
+	"context"
+	"io"
+	"net"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/core/router"
+	"github.com/go-gost/x/internal/loader"
+)
+
+type options struct {
+	routes      []*router.Route
+	fileLoader  loader.Loader
+	redisLoader loader.Loader
+	httpLoader  loader.Loader
+	period      time.Duration
+	logger      logger.Logger
+}
+
+type Option func(opts *options)
+
+func RoutesOption(routes []*router.Route) Option {
+	return func(opts *options) {
+		opts.routes = routes
+	}
+}
+
+func ReloadPeriodOption(period time.Duration) Option {
+	return func(opts *options) {
+		opts.period = period
+	}
+}
+
+func FileLoaderOption(fileLoader loader.Loader) Option {
+	return func(opts *options) {
+		opts.fileLoader = fileLoader
+	}
+}
+
+func RedisLoaderOption(redisLoader loader.Loader) Option {
+	return func(opts *options) {
+		opts.redisLoader = redisLoader
+	}
+}
+
+func HTTPLoaderOption(httpLoader loader.Loader) Option {
+	return func(opts *options) {
+		opts.httpLoader = httpLoader
+	}
+}
+
+func LoggerOption(logger logger.Logger) Option {
+	return func(opts *options) {
+		opts.logger = logger
+	}
+}
+
+type localRouter struct {
+	routes     []*router.Route
+	cancelFunc context.CancelFunc
+	options    options
+	mu         sync.RWMutex
+}
+
+// NewRouter creates and initializes a new Router.
+func NewRouter(opts ...Option) router.Router {
+	var options options
+	for _, opt := range opts {
+		opt(&options)
+	}
+
+	ctx, cancel := context.WithCancel(context.TODO())
+
+	r := &localRouter{
+		cancelFunc: cancel,
+		options:    options,
+	}
+
+	if err := r.reload(ctx); err != nil {
+		options.logger.Warnf("reload: %v", err)
+	}
+	if r.options.period > 0 {
+		go r.periodReload(ctx)
+	}
+
+	return r
+}
+
+func (p *localRouter) periodReload(ctx context.Context) error {
+	period := p.options.period
+	if period < time.Second {
+		period = time.Second
+	}
+	ticker := time.NewTicker(period)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			if err := p.reload(ctx); err != nil {
+				p.options.logger.Warnf("reload: %v", err)
+				// return err
+			}
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+}
+
+func (r *localRouter) reload(ctx context.Context) error {
+	routes := r.options.routes
+
+	v, err := r.load(ctx)
+	if err != nil {
+		return err
+	}
+	routes = append(routes, v...)
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	r.routes = routes
+
+	return nil
+}
+
+func (p *localRouter) load(ctx context.Context) (routes []*router.Route, err error) {
+	if p.options.fileLoader != nil {
+		if lister, ok := p.options.fileLoader.(loader.Lister); ok {
+			list, er := lister.List(ctx)
+			if er != nil {
+				p.options.logger.Warnf("file loader: %v", er)
+			}
+			for _, s := range list {
+				routes = append(routes, p.parseLine(s))
+			}
+		} else {
+			fr, er := p.options.fileLoader.Load(ctx)
+			if er != nil {
+				p.options.logger.Warnf("file loader: %v", er)
+			}
+			if v, _ := p.parseRoutes(fr); v != nil {
+				routes = append(routes, v...)
+			}
+		}
+	}
+	if p.options.redisLoader != nil {
+		if lister, ok := p.options.redisLoader.(loader.Lister); ok {
+			list, er := lister.List(ctx)
+			if er != nil {
+				p.options.logger.Warnf("redis loader: %v", er)
+			}
+			for _, v := range list {
+				routes = append(routes, p.parseLine(v))
+			}
+		} else {
+			r, er := p.options.redisLoader.Load(ctx)
+			if er != nil {
+				p.options.logger.Warnf("redis loader: %v", er)
+			}
+			v, _ := p.parseRoutes(r)
+			routes = append(routes, v...)
+		}
+	}
+	if p.options.httpLoader != nil {
+		r, er := p.options.httpLoader.Load(ctx)
+		if er != nil {
+			p.options.logger.Warnf("http loader: %v", er)
+		}
+		v, _ := p.parseRoutes(r)
+		routes = append(routes, v...)
+	}
+
+	p.options.logger.Debugf("load items %d", len(routes))
+	return
+}
+
+func (p *localRouter) parseRoutes(r io.Reader) (routes []*router.Route, err error) {
+	if r == nil {
+		return
+	}
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		if route := p.parseLine(scanner.Text()); route != nil {
+			routes = append(routes, route)
+		}
+	}
+
+	err = scanner.Err()
+	return
+}
+
+func (p *localRouter) GetRoute(ctx context.Context, dst net.IP, opts ...router.Option) *router.Route {
+	if dst == nil || p == nil {
+		return nil
+	}
+
+	p.mu.RLock()
+	routes := p.routes
+	p.mu.RUnlock()
+
+	for _, route := range routes {
+		if route.Net != nil && route.Net.Contains(dst) {
+			return route
+		}
+	}
+	return nil
+}
+
+func (*localRouter) SetRoute(ctx context.Context, route *router.Route, opts ...router.Option) bool {
+	return false
+}
+
+func (*localRouter) parseLine(s string) (route *router.Route) {
+	line := strings.Replace(s, "\t", " ", -1)
+	line = strings.TrimSpace(line)
+	if n := strings.IndexByte(line, '#'); n >= 0 {
+		line = line[:n]
+	}
+	var sp []string
+	for _, s := range strings.Split(line, " ") {
+		if s = strings.TrimSpace(s); s != "" {
+			sp = append(sp, s)
+		}
+	}
+	if len(sp) < 2 {
+		return // invalid lines are ignored
+	}
+
+	return ParseRoute(sp[0], sp[1])
+}
+
+func (p *localRouter) Close() error {
+	p.cancelFunc()
+	if p.options.fileLoader != nil {
+		p.options.fileLoader.Close()
+	}
+	if p.options.redisLoader != nil {
+		p.options.redisLoader.Close()
+	}
+	return nil
+}
+
+func ParseRoute(dst string, gateway string) *router.Route {
+	_, ipNet, _ := net.ParseCIDR(dst)
+	if ipNet == nil {
+		return nil
+	}
+	gw := net.ParseIP(gateway)
+	if gw == nil {
+		return nil
+	}
+
+	return &router.Route{
+		Net:     ipNet,
+		Gateway: gw,
+	}
+}