package main
// read in all files from netdb dir into a slice of routerinfos
// for every unique requesting IP
// look up that IP in the db
// - if it exists, check the creation time
// - if the creation time is within the threshold, serve up the routerinfos
// - if the creation time is outside the threshold, or if it does not exist generate a new slice of routerinfos from the current master set
// at some regular interval, update the master slice with fresh netdb routerinfos
// can serve up html/ul of routerinfos
// can serve up su3 signed file
// https://geti2p.net/en/docs/spec/updates
import (
"github.com/PuerkitoBio/throttled"
"github.com/PuerkitoBio/throttled/store"
"github.com/gorilla/handlers"
"github.com/gorilla/mux"
"html/template"
"io"
"io/ioutil"
"log"
"math/rand"
"net/http"
"os"
"time"
)
func proxiedHandler(h http.Handler) http.Handler {
return remoteAddrFixup{h}
}
type remoteAddrFixup struct {
h http.Handler
}
func (h remoteAddrFixup) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if prior, ok := r.Header["X-Forwarded-For"]; ok {
r.RemoteAddr = prior[0]
}
h.h.ServeHTTP(w, r)
}
type Reseeder struct {
NetDBDir string
nextMap chan []string
RefreshInterval time.Duration
Proxy bool
Verbose bool
RateLimit int
listTemplate *template.Template
}
func (rs *Reseeder) Start(addr, port, cert, key string) {
var err error
go rs.runMap()
go rs.refresher()
// parse the template for routerInfo lists
rs.listTemplate, err = template.New("routerinfos").Parse(`NetDB`)
if err != nil {
log.Fatalln("error parsing routerInfo list template", err)
return
}
r := mux.NewRouter()
s := r.PathPrefix("/netdb").Subrouter()
s.HandleFunc("/", rs.listHandler)
s.HandleFunc("/i2pseeds.su3", rs.su3Handler)
s.HandleFunc(`/routerInfo-{hash:[A-Za-z0-9+/\-=~]+}.dat`, rs.routerInfoHandler)
// timeout
muxWithMiddlewares := http.TimeoutHandler(r, time.Second*5, "Timeout!")
if rs.Proxy {
muxWithMiddlewares = proxiedHandler(muxWithMiddlewares)
}
th := throttled.RateLimit(throttled.PerMin(rs.RateLimit), &throttled.VaryBy{RemoteAddr: true}, store.NewMemStore(0))
muxWithMiddlewares = th.Throttle(muxWithMiddlewares)
if rs.Verbose {
muxWithMiddlewares = handlers.CombinedLoggingHandler(os.Stdout, muxWithMiddlewares)
}
// try to start tls server
if _, err = os.Stat(cert); err == nil {
if _, err = os.Stat(key); err == nil {
log.Println("Starting TLS reseed server on " + addr + ":" + port)
err := http.ListenAndServeTLS(addr+":"+port, cert, key, muxWithMiddlewares)
if nil != err {
log.Fatalln(err)
}
return
}
}
// fall back to regular http server
log.Println("Starting reseed server on " + addr + ":" + port)
err = http.ListenAndServe(addr+":"+port, muxWithMiddlewares)
if nil != err {
log.Fatalln(err)
}
}
func NewReseeder() *Reseeder {
return &Reseeder{nextMap: make(chan []string)}
}
func (r *Reseeder) runMap() {
var m []string
for {
select {
case m = <-r.nextMap:
case r.nextMap <- m:
}
}
}
func (r *Reseeder) refresher() {
for {
log.Println("Updating routerInfos")
r.Refresh()
time.Sleep(r.RefreshInterval)
}
}
func (r *Reseeder) Refresh() {
var m []string
src, err := ioutil.ReadDir(r.NetDBDir)
if nil != err {
log.Fatalln("error reading netdb dir", err)
return
}
// randomize the file order
files := make([]os.FileInfo, len(src))
perm := rand.Perm(len(src))
for i, v := range perm {
files[v] = src[i]
}
added := 0
for _, file := range files {
if !file.IsDir() && file.Name() != "." && file.Name() != ".." {
m = append(m, file.Name())
added++
}
if added >= 50 {
break
}
}
r.nextMap <- m
}
func (rs *Reseeder) listHandler(w http.ResponseWriter, r *http.Request) {
err := rs.listTemplate.Execute(w, <-rs.nextMap)
if err != nil {
log.Fatalln("error rending list template", err)
}
}
func (rs *Reseeder) su3Handler(w http.ResponseWriter, r *http.Request) {
http.NotFound(w, r)
}
func (rs *Reseeder) routerInfoHandler(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
fileName := "routerInfo-" + vars["hash"] + ".dat"
f, err := os.Open(rs.NetDBDir + "/" + fileName)
if nil != err {
http.NotFound(w, r)
log.Println("error sending file", err)
return
}
io.Copy(w, f)
}