tracker/frontend/http/writer.go
2016-09-29 18:48:35 -04:00

117 lines
2.9 KiB
Go

package http
import (
"net/http"
log "github.com/Sirupsen/logrus"
"github.com/chihaya/chihaya/bittorrent"
"github.com/chihaya/chihaya/frontend/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()
} else {
log.Errorf("http: internal error: %s", err)
}
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, compact4(peer)...)
}
if len(IPv4CompactDict) > 0 {
bdict["peers"] = IPv4CompactDict
}
// Add the IPv6 peers to the dictionary.
for _, peer := range resp.IPv6Peers {
IPv6CompactDict = append(IPv6CompactDict, compact6(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 compact4(peer bittorrent.Peer) (buf []byte) {
if ip := peer.IP.To4(); ip == nil {
panic("non-IPv4 IP for Peer in IPv4Peers")
} else {
buf = []byte(ip)
}
buf = append(buf, byte(peer.Port>>8))
buf = append(buf, byte(peer.Port&0xff))
return
}
func compact6(peer bittorrent.Peer) (buf []byte) {
if ip := peer.IP.To16(); ip == nil {
panic("non-IPv6 IP for Peer in IPv6Peers")
} else {
buf = []byte(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,
}
}