echoip/api/api.go
2018-02-09 20:41:30 +01:00

282 lines
6.7 KiB
Go

package api
import (
"encoding/json"
"fmt"
"html/template"
"github.com/mpolden/ipd/useragent"
"github.com/sirupsen/logrus"
"math/big"
"net"
"net/http"
"path/filepath"
"strconv"
"strings"
"github.com/gorilla/mux"
)
const (
jsonMediaType = "application/json"
textMediaType = "text/plain"
)
type API struct {
Template string
IPHeader string
oracle Oracle
log *logrus.Logger
}
type Response struct {
IP net.IP `json:"ip"`
IPDecimal *big.Int `json:"ip_decimal"`
Country string `json:"country,omitempty"`
CountryISO string `json:"country_iso,omitempty"`
City string `json:"city,omitempty"`
Hostname string `json:"hostname,omitempty"`
}
type PortResponse struct {
IP net.IP `json:"ip"`
Port uint64 `json:"port"`
Reachable bool `json:"reachable"`
}
func New(oracle Oracle, logger *logrus.Logger) *API {
return &API{oracle: oracle, log: logger}
}
func ipToDecimal(ip net.IP) *big.Int {
i := big.NewInt(0)
if to4 := ip.To4(); to4 != nil {
i.SetBytes(to4)
} else {
i.SetBytes(ip)
}
return i
}
func ipFromRequest(header string, r *http.Request) (net.IP, error) {
remoteIP := r.Header.Get(header)
if remoteIP == "" {
host, _, err := net.SplitHostPort(r.RemoteAddr)
if err != nil {
return nil, err
}
remoteIP = host
}
ip := net.ParseIP(remoteIP)
if ip == nil {
return nil, fmt.Errorf("could not parse IP: %s", remoteIP)
}
return ip, nil
}
func (a *API) newResponse(r *http.Request) (Response, error) {
ip, err := ipFromRequest(a.IPHeader, r)
if err != nil {
return Response{}, err
}
ipDecimal := ipToDecimal(ip)
country, err := a.oracle.LookupCountry(ip)
if err != nil {
a.log.Debug(err)
}
countryISO, err := a.oracle.LookupCountryISO(ip)
if err != nil {
a.log.Debug(err)
}
city, err := a.oracle.LookupCity(ip)
if err != nil {
a.log.Debug(err)
}
hostnames, err := a.oracle.LookupAddr(ip)
if err != nil {
a.log.Debug(err)
}
return Response{
IP: ip,
IPDecimal: ipDecimal,
Country: country,
CountryISO: countryISO,
City: city,
Hostname: strings.Join(hostnames, " "),
}, nil
}
func (a *API) newPortResponse(r *http.Request) (PortResponse, error) {
vars := mux.Vars(r)
port, err := strconv.ParseUint(vars["port"], 10, 16)
if err != nil {
return PortResponse{Port: port}, err
}
if port < 1 || port > 65355 {
return PortResponse{Port: port}, fmt.Errorf("invalid port: %d", port)
}
ip, err := ipFromRequest(a.IPHeader, r)
if err != nil {
return PortResponse{Port: port}, err
}
err = a.oracle.LookupPort(ip, port)
return PortResponse{
IP: ip,
Port: port,
Reachable: err == nil,
}, nil
}
func (a *API) CLIHandler(w http.ResponseWriter, r *http.Request) *appError {
ip, err := ipFromRequest(a.IPHeader, r)
if err != nil {
return internalServerError(err)
}
fmt.Fprintln(w, ip.String())
return nil
}
func (a *API) CLICountryHandler(w http.ResponseWriter, r *http.Request) *appError {
response, err := a.newResponse(r)
if err != nil {
return internalServerError(err)
}
fmt.Fprintln(w, response.Country)
return nil
}
func (a *API) CLICountryISOHandler(w http.ResponseWriter, r *http.Request) *appError {
response, err := a.newResponse(r)
if err != nil {
return internalServerError(err)
}
fmt.Fprintln(w, response.CountryISO)
return nil
}
func (a *API) CLICityHandler(w http.ResponseWriter, r *http.Request) *appError {
response, err := a.newResponse(r)
if err != nil {
return internalServerError(err)
}
fmt.Fprintln(w, response.City)
return nil
}
func (a *API) JSONHandler(w http.ResponseWriter, r *http.Request) *appError {
response, err := a.newResponse(r)
if err != nil {
return internalServerError(err).AsJSON()
}
b, err := json.Marshal(response)
if err != nil {
return internalServerError(err).AsJSON()
}
w.Header().Set("Content-Type", jsonMediaType)
w.Write(b)
return nil
}
func (a *API) PortHandler(w http.ResponseWriter, r *http.Request) *appError {
response, err := a.newPortResponse(r)
if err != nil {
return badRequest(err).WithMessage(fmt.Sprintf("Invalid port: %d", response.Port)).AsJSON()
}
b, err := json.Marshal(response)
if err != nil {
return internalServerError(err).AsJSON()
}
w.Header().Set("Content-Type", jsonMediaType)
w.Write(b)
return nil
}
func (a *API) DefaultHandler(w http.ResponseWriter, r *http.Request) *appError {
response, err := a.newResponse(r)
if err != nil {
return internalServerError(err)
}
t, err := template.New(filepath.Base(a.Template)).ParseFiles(a.Template)
if err != nil {
return internalServerError(err)
}
var data = struct {
Host string
Response
Oracle
}{r.Host, response, a.oracle}
if err := t.Execute(w, &data); err != nil {
return internalServerError(err)
}
return nil
}
func (a *API) NotFoundHandler(w http.ResponseWriter, r *http.Request) *appError {
err := notFound(nil).WithMessage("404 page not found")
if r.Header.Get("accept") == jsonMediaType {
err = err.AsJSON()
}
return err
}
func cliMatcher(r *http.Request, rm *mux.RouteMatch) bool {
ua := useragent.Parse(r.UserAgent())
switch ua.Product {
case "curl", "HTTPie", "Wget", "fetch libfetch", "Go", "Go-http-client", "ddclient":
return true
}
return false
}
type appHandler func(http.ResponseWriter, *http.Request) *appError
func (fn appHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if e := fn(w, r); e != nil { // e is *appError
// When Content-Type for error is JSON, we need to marshal the response into JSON
if e.IsJSON() {
var data = struct {
Error string `json:"error"`
}{e.Message}
b, err := json.Marshal(data)
if err != nil {
panic(err)
}
e.Message = string(b)
}
// Set Content-Type of response if set in error
if e.ContentType != "" {
w.Header().Set("Content-Type", e.ContentType)
}
w.WriteHeader(e.Code)
fmt.Fprint(w, e.Message)
}
}
func (a *API) Router() http.Handler {
r := mux.NewRouter()
// JSON
r.Handle("/", appHandler(a.JSONHandler)).Methods("GET").Headers("Accept", jsonMediaType)
r.Handle("/json", appHandler(a.JSONHandler)).Methods("GET")
// CLI
r.Handle("/", appHandler(a.CLIHandler)).Methods("GET").MatcherFunc(cliMatcher)
r.Handle("/", appHandler(a.CLIHandler)).Methods("GET").Headers("Accept", textMediaType)
r.Handle("/ip", appHandler(a.CLIHandler)).Methods("GET")
r.Handle("/country", appHandler(a.CLICountryHandler)).Methods("GET")
r.Handle("/country-iso", appHandler(a.CLICountryISOHandler)).Methods("GET")
r.Handle("/city", appHandler(a.CLICityHandler)).Methods("GET")
// Browser
r.Handle("/", appHandler(a.DefaultHandler)).Methods("GET")
// Port testing
r.Handle("/port/{port:[0-9]+}", appHandler(a.PortHandler)).Methods("GET")
// Not found handler which returns JSON when appropriate
r.NotFoundHandler = appHandler(a.NotFoundHandler)
return r
}