tracker/frontends/http/writer.go
2016-08-16 22:17:10 -04:00

112 lines
3.1 KiB
Go

// Copyright 2016 Jimmy Zelinskie
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package http
import (
"net/http"
"github.com/jzelinskie/trakr/bittorrent"
"github.com/jzelinskie/trakr/frontends/http/bencode"
)
// WriteError communicates an error to a BitTorrent client over HTTP.
func WriteError(w http.ResponseWriter, err error) error {
message := "internal server error"
if _, clientErr := err.(bittorrent.ClientError); clientErr {
message = err.Error()
}
w.WriteHeader(http.StatusOK)
return bencode.NewEncoder(w).Encode(bencode.Dict{
"failure reason": message,
})
}
// WriteAnnounceResponse communicates the results of an Announce to a
// BitTorrent client over HTTP.
func WriteAnnounceResponse(w http.ResponseWriter, resp *bittorrent.AnnounceResponse) error {
bdict := bencode.Dict{
"complete": resp.Complete,
"incomplete": resp.Incomplete,
"interval": resp.Interval,
"min interval": resp.MinInterval,
}
// Add the peers to the dictionary in the compact format.
if resp.Compact {
var IPv4CompactDict, IPv6CompactDict []byte
// Add the IPv4 peers to the dictionary.
for _, peer := range resp.IPv4Peers {
IPv4CompactDict = append(IPv4CompactDict, compact(peer)...)
}
if len(IPv4CompactDict) > 0 {
bdict["peers"] = IPv4CompactDict
}
// Add the IPv6 peers to the dictionary.
for _, peer := range resp.IPv6Peers {
IPv6CompactDict = append(IPv6CompactDict, compact(peer)...)
}
if len(IPv6CompactDict) > 0 {
bdict["peers6"] = IPv6CompactDict
}
return bencode.NewEncoder(w).Encode(bdict)
}
// Add the peers to the dictionary.
var peers []bencode.Dict
for _, peer := range resp.IPv4Peers {
peers = append(peers, dict(peer))
}
for _, peer := range resp.IPv6Peers {
peers = append(peers, dict(peer))
}
bdict["peers"] = peers
return bencode.NewEncoder(w).Encode(bdict)
}
// WriteScrapeResponse communicates the results of a Scrape to a BitTorrent
// client over HTTP.
func WriteScrapeResponse(w http.ResponseWriter, resp *bittorrent.ScrapeResponse) error {
filesDict := bencode.NewDict()
for infohash, scrape := range resp.Files {
filesDict[string(infohash[:])] = bencode.Dict{
"complete": scrape.Complete,
"incomplete": scrape.Incomplete,
}
}
return bencode.NewEncoder(w).Encode(bencode.Dict{
"files": filesDict,
})
}
func compact(peer bittorrent.Peer) (buf []byte) {
buf = []byte(peer.IP)
buf = append(buf, byte(peer.Port>>8))
buf = append(buf, byte(peer.Port&0xff))
return
}
func dict(peer bittorrent.Peer) bencode.Dict {
return bencode.Dict{
"peer id": string(peer.ID[:]),
"ip": peer.IP.String(),
"port": peer.Port,
}
}