x/handler/redirect/udp/handler.go
2023-04-18 20:52:56 +08:00

111 lines
2.3 KiB
Go

package redirect
import (
"context"
"fmt"
"net"
"time"
"github.com/go-gost/core/chain"
"github.com/go-gost/core/handler"
md "github.com/go-gost/core/metadata"
netpkg "github.com/go-gost/x/internal/net"
"github.com/go-gost/x/registry"
)
func init() {
registry.HandlerRegistry().Register("redu", NewHandler)
}
type redirectHandler struct {
router *chain.Router
md metadata
options handler.Options
}
func NewHandler(opts ...handler.Option) handler.Handler {
options := handler.Options{}
for _, opt := range opts {
opt(&options)
}
return &redirectHandler{
options: options,
}
}
func (h *redirectHandler) Init(md md.Metadata) (err error) {
if err = h.parseMetadata(md); err != nil {
return
}
h.router = h.options.Router
if h.router == nil {
h.router = chain.NewRouter(chain.LoggerRouterOption(h.options.Logger))
}
return
}
func (h *redirectHandler) Handle(ctx context.Context, conn net.Conn, opts ...handler.HandleOption) error {
defer conn.Close()
start := time.Now()
log := h.options.Logger.WithFields(map[string]any{
"remote": conn.RemoteAddr().String(),
"local": conn.LocalAddr().String(),
})
log.Infof("%s <> %s", conn.RemoteAddr(), conn.LocalAddr())
defer func() {
log.WithFields(map[string]any{
"duration": time.Since(start),
}).Infof("%s >< %s", conn.RemoteAddr(), conn.LocalAddr())
}()
if !h.checkRateLimit(conn.RemoteAddr()) {
return nil
}
dstAddr := conn.LocalAddr()
log = log.WithFields(map[string]any{
"dst": fmt.Sprintf("%s/%s", dstAddr, dstAddr.Network()),
})
log.Debugf("%s >> %s", conn.RemoteAddr(), dstAddr)
if h.options.Bypass != nil && h.options.Bypass.Contains(ctx, dstAddr.String()) {
log.Debug("bypass: ", dstAddr)
return nil
}
cc, err := h.router.Dial(ctx, dstAddr.Network(), dstAddr.String())
if err != nil {
log.Error(err)
return err
}
defer cc.Close()
t := time.Now()
log.Debugf("%s <-> %s", conn.RemoteAddr(), dstAddr)
netpkg.Transport(conn, cc)
log.WithFields(map[string]any{
"duration": time.Since(t),
}).Debugf("%s >-< %s", conn.RemoteAddr(), dstAddr)
return nil
}
func (h *redirectHandler) checkRateLimit(addr net.Addr) bool {
if h.options.RateLimiter == nil {
return true
}
host, _, _ := net.SplitHostPort(addr.String())
if limiter := h.options.RateLimiter.Limiter(host); limiter != nil {
return limiter.Allow(1)
}
return true
}