trip.go

   1 /*
   2 tofuproxy -- HTTP proxy with TLS certificates management
   3 Copyright (C) 2021 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 package tofuproxy
  19
  20 import (
  21         "fmt"
  22         "io"
  23         "log"
  24         "net"
  25         "net/http"
  26         "strings"
  27         "time"
  28
  29         "github.com/dustin/go-humanize"
  30         "go.stargrave.org/tofuproxy/fifos"
  31         "go.stargrave.org/tofuproxy/rounds"
  32 )
  33
  34 var (
  35         transport = http.Transport{
  36                 DialContext: (&net.Dialer{
  37                         Timeout:   time.Minute,
  38                         KeepAlive: time.Minute,
  39                 }).DialContext,
  40                 MaxIdleConns:        http.DefaultTransport.(*http.Transport).MaxIdleConns,
  41                 IdleConnTimeout:     http.DefaultTransport.(*http.Transport).IdleConnTimeout * 2,
  42                 TLSHandshakeTimeout: time.Minute,
  43                 DialTLSContext:      dialTLS,
  44                 ForceAttemptHTTP2:   true,
  45         }
  46         proxyHeaders = map[string]struct{}{
  47                 "Location":       {},
  48                 "Content-Type":   {},
  49                 "Content-Length": {},
  50         }
  51 )
  52
  53 type Round func(
  54         host string,
  55         resp *http.Response,
  56         w http.ResponseWriter,
  57         req *http.Request,
  58 ) (bool, error)
  59
  60 func roundTrip(w http.ResponseWriter, req *http.Request) {
  61         host := strings.TrimSuffix(req.URL.Host, ":443")
  62         for _, round := range []Round{
  63                 rounds.RoundNoHead,
  64                 rounds.RoundLog,
  65                 rounds.RoundDenySpy,
  66                 rounds.RoundRedditOld,
  67                 rounds.RoundHabrImage,
  68         } {
  69                 if cont, _ := round(host, nil, w, req); !cont {
  70                         return
  71                 }
  72         }
  73
  74         resp, err := transport.RoundTrip(req)
  75         if err != nil {
  76                 fifos.SinkErr <- fmt.Sprintf("%s\t%s", req.URL.Host, err.Error())
  77                 http.Error(w, err.Error(), http.StatusBadGateway)
  78                 return
  79         }
  80
  81         for k, vs := range resp.Header {
  82                 if _, ok := proxyHeaders[k]; ok {
  83                         continue
  84                 }
  85                 for _, v := range vs {
  86                         w.Header().Add(k, v)
  87                 }
  88         }
  89
  90         for _, round := range []Round{
  91                 rounds.RoundDenyFonts,
  92                 rounds.RoundTranscodeWebP,
  93                 rounds.RoundTranscodeJXL,
  94                 rounds.RoundRedirectHTML,
  95         } {
  96                 cont, err := round(host, resp, w, req)
  97                 if err != nil {
  98                         http.Error(w, err.Error(), http.StatusBadGateway)
  99                         return
 100                 }
 101                 if !cont {
 102                         return
 103                 }
 104         }
 105
 106         for h := range proxyHeaders {
 107                 if v := resp.Header.Get(h); v != "" {
 108                         w.Header().Add(h, v)
 109                 }
 110         }
 111         w.WriteHeader(resp.StatusCode)
 112         n, err := io.Copy(w, resp.Body)
 113         if err != nil {
 114                 log.Printf("Error during %s: %+v\n", req.URL, err)
 115         }
 116         resp.Body.Close()
 117         msg := fmt.Sprintf(
 118                 "%s %s\t%s\t%s\t%s",
 119                 req.Method,
 120                 req.URL.String(),
 121                 resp.Status,
 122                 resp.Header.Get("Content-Type"),
 123                 humanize.IBytes(uint64(n)),
 124         )
 125         if resp.StatusCode == http.StatusOK {
 126                 fifos.SinkOK <- msg
 127         } else {
 128                 fifos.SinkOther <- msg
 129         }
 130 }