/
api.go
112 lines (98 loc) · 2.39 KB
/
api.go
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package api
import (
"fmt"
"github.com/cpacia/ens-lite"
"github.com/miekg/dns"
"net/http"
"path"
"time"
"strconv"
"strings"
)
const Addr = "127.0.0.1:31313"
var client *apiClient
type apiClient struct {
ensClient *ens.ENSLiteClient
cache map[string]cachedRecord
}
type cachedRecord struct {
rr dns.RR
expiration time.Time
}
func ServeAPI(ensClient *ens.ENSLiteClient) error {
topMux := http.NewServeMux()
handler := new(resolverHandler)
topMux.Handle("/resolver/", handler)
topMux.Handle("/ws", newWSAPIHandler(ensClient))
srv := &http.Server{Addr: Addr, Handler: topMux}
handler.server = srv
client = &apiClient{ensClient, make(map[string]cachedRecord)}
err := srv.ListenAndServe()
if err != nil {
return err
}
return nil
}
type resolverHandler struct {
server *http.Server
}
func resolve(w http.ResponseWriter, r *http.Request) {
urlPath, name := path.Split(r.URL.Path)
_, queryType := path.Split(urlPath[:len(urlPath)-1])
if strings.ToLower(queryType) == "dns" {
lookup := r.URL.Query().Get("lookup")
l, _ := strconv.ParseBool(lookup)
record, ok := client.cache[name]
if ok {
if time.Now().Before(record.expiration) {
fmt.Fprint(w, record.rr.(*dns.A).A.String())
return
} else {
delete(client.cache, name)
}
}
resp, err := client.ensClient.ResolveDNS(name)
if err != nil && err == ens.ErrorBlockchainSyncing {
w.WriteHeader(http.StatusServiceUnavailable)
return
} else if err != nil || len(resp) == 0 {
w.WriteHeader(http.StatusNotFound)
return
}
client.cache[name] = cachedRecord{resp[0], time.Now().Add(time.Duration(resp[0].Header().Ttl))}
if l {
var ret string
for i, rec := range resp {
ret += rec.String()
if i != len(resp) - 1 {
ret += "\n"
}
}
fmt.Fprint(w, ret)
} else {
fmt.Fprint(w, resp[0].(*dns.A).A.String())
}
} else if strings.ToLower(queryType) == "address" {
resp, err := client.ensClient.ResolveAddress(name)
if err != nil && err == ens.ErrorBlockchainSyncing {
w.WriteHeader(http.StatusServiceUnavailable)
return
} else if err != nil {
w.WriteHeader(http.StatusNotFound)
return
}
fmt.Fprint(w, resp.Hex())
}
}
func (rh resolverHandler) shutdown() {
client.ensClient.Stop()
rh.server.Close()
}
func (rh resolverHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
switch r.Method {
case "GET":
resolve(w, r)
case "POST":
rh.shutdown()
}
}