ginuerzh
28d3ffa310
Fix async resolve goroutine using caller's cancelable context by switching to context.WithoutCancel. Fix NewGRPCPlugin silently returning broken resolver on connection failure. Fix "resolover" typo in log field. Add doc comments to all exported symbols.
110 lines
2.3 KiB
Go
110 lines
2.3 KiB
Go
package resolver
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import (
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"bytes"
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"context"
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"encoding/json"
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"errors"
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"fmt"
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"net"
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"net/http"
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"github.com/go-gost/core/logger"
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"github.com/go-gost/core/resolver"
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ctxvalue "github.com/go-gost/x/ctx"
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"github.com/go-gost/x/internal/plugin"
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)
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// httpPluginRequest is the JSON body sent to an HTTP resolver plugin.
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type httpPluginRequest struct {
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Network string `json:"network"`
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Host string `json:"host"`
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Client string `json:"client"`
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}
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// httpPluginResponse is the JSON response from an HTTP resolver plugin.
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type httpPluginResponse struct {
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IPs []string `json:"ips"`
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OK bool `json:"ok"`
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}
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// httpPlugin is a Resolver implementation that delegates to an external HTTP service.
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type httpPlugin struct {
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url string
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client *http.Client
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header http.Header
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log logger.Logger
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}
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// NewHTTPPlugin creates an Resolver plugin based on HTTP.
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func NewHTTPPlugin(name string, url string, opts ...plugin.Option) resolver.Resolver {
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var options plugin.Options
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for _, opt := range opts {
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opt(&options)
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}
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return &httpPlugin{
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url: url,
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client: plugin.NewHTTPClient(&options),
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header: options.Header,
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log: logger.Default().WithFields(map[string]any{
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"kind": "resolver",
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"resolver": name,
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}),
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}
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}
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func (p *httpPlugin) Resolve(ctx context.Context, network, host string, opts ...resolver.Option) (ips []net.IP, err error) {
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p.log.Debugf("resolve %s/%s", host, network)
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if p.client == nil {
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return
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}
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rb := httpPluginRequest{
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Network: network,
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Host: host,
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Client: string(ctxvalue.ClientIDFromContext(ctx)),
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}
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v, err := json.Marshal(&rb)
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if err != nil {
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return
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}
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req, err := http.NewRequestWithContext(ctx, http.MethodPost, p.url, bytes.NewReader(v))
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if err != nil {
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return
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}
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if p.header != nil {
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req.Header = p.header.Clone()
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}
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req.Header.Set("Content-Type", "application/json")
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resp, err := p.client.Do(req)
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if err != nil {
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return
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}
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defer resp.Body.Close()
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if resp.StatusCode != http.StatusOK {
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err = fmt.Errorf("%s", resp.Status)
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return
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}
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res := httpPluginResponse{}
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if err = json.NewDecoder(resp.Body).Decode(&res); err != nil {
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return
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}
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if !res.OK {
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return nil, errors.New("resolve failed")
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}
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for _, s := range res.IPs {
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if ip := net.ParseIP(s); ip != nil {
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ips = append(ips, ip)
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}
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}
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return ips, nil
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}
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