tracker/middleware/torrentapproval/torrentapproval.go
Pierre-Alain TORET 82c9f08f4f middleware : add torrent approval package
this makes it possible to specify a torrent whitelist/blacklist in the
configuration file based on their hexadecimal hash.

Fixes #375

Signed-off-by: Pierre-Alain TORET <pierre-alain.toret@protonmail.com>
2018-09-19 14:11:13 +02:00

109 lines
2.9 KiB
Go

// Package torrentapproval implements a Hook that fails an Announce based on a
// whitelist or blacklist of torrent hash.
package torrentapproval
import (
"context"
"encoding/hex"
"fmt"
"gopkg.in/yaml.v2"
"github.com/chihaya/chihaya/bittorrent"
"github.com/chihaya/chihaya/middleware"
)
// Name is the name by which this middleware is registered with Chihaya.
const Name = "torrent approval"
func init() {
middleware.RegisterDriver(Name, driver{})
}
var _ middleware.Driver = driver{}
type driver struct{}
func (d driver) NewHook(optionBytes []byte) (middleware.Hook, error) {
var cfg Config
err := yaml.Unmarshal(optionBytes, &cfg)
if err != nil {
return nil, fmt.Errorf("invalid options for middleware %s: %s", Name, err)
}
return NewHook(cfg)
}
// ErrTorrentUnapproved is the error returned when a torrent hash is invalid.
var ErrTorrentUnapproved = bittorrent.ClientError("unapproved torrent")
// Config represents all the values required by this middleware to validate
// torrents based on their hash value.
type Config struct {
Whitelist []string `yaml:"whitelist"`
Blacklist []string `yaml:"blacklist"`
}
type hook struct {
approved map[bittorrent.InfoHash]struct{}
unapproved map[bittorrent.InfoHash]struct{}
}
// NewHook returns an instance of the torrent approval middleware.
func NewHook(cfg Config) (middleware.Hook, error) {
h := &hook{
approved: make(map[bittorrent.InfoHash]struct{}),
unapproved: make(map[bittorrent.InfoHash]struct{}),
}
if len(cfg.Whitelist) > 0 && len(cfg.Blacklist) > 0 {
return nil, fmt.Errorf("using both whitelist and blacklist is invalid")
}
for _, hashString := range cfg.Whitelist {
hashinfo, err := hex.DecodeString(hashString)
if err != nil {
return nil, fmt.Errorf("whitelist : invalid hash %s", hashString)
}
if len(hashinfo) != 20 {
return nil, fmt.Errorf("whitelist : hash %s is not 20 byes", hashString)
}
h.approved[bittorrent.InfoHashFromBytes(hashinfo)] = struct{}{}
}
for _, hashString := range cfg.Blacklist {
hashinfo, err := hex.DecodeString(hashString)
if err != nil {
return nil, fmt.Errorf("blacklist : invalid hash %s", hashString)
}
if len(hashinfo) != 20 {
return nil, fmt.Errorf("blacklist : hash %s is not 20 byes", hashString)
}
h.unapproved[bittorrent.InfoHashFromBytes(hashinfo)] = struct{}{}
}
return h, nil
}
func (h *hook) HandleAnnounce(ctx context.Context, req *bittorrent.AnnounceRequest, resp *bittorrent.AnnounceResponse) (context.Context, error) {
infohash := req.InfoHash
if len(h.approved) > 0 {
if _, found := h.approved[infohash]; !found {
return ctx, ErrTorrentUnapproved
}
}
if len(h.unapproved) > 0 {
if _, found := h.unapproved[infohash]; found {
return ctx, ErrTorrentUnapproved
}
}
return ctx, nil
}
func (h *hook) HandleScrape(ctx context.Context, req *bittorrent.ScrapeRequest, resp *bittorrent.ScrapeResponse) (context.Context, error) {
// Scrapes don't require any protection.
return ctx, nil
}