62 lines
1.8 KiB
Go
62 lines
1.8 KiB
Go
package udp
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/binary"
|
|
"fmt"
|
|
"io"
|
|
"time"
|
|
|
|
"github.com/jzelinskie/trakr/bittorrent"
|
|
)
|
|
|
|
// WriteError writes the failure reason as a null-terminated string.
|
|
func WriteError(w io.Writer, txID []byte, err error) {
|
|
// If the client wasn't at fault, acknowledge it.
|
|
if _, ok := err.(bittorrent.ClientError); !ok {
|
|
err = fmt.Errorf("internal error occurred: %s", err.Error())
|
|
}
|
|
|
|
var buf bytes.Buffer
|
|
writeHeader(&buf, txID, errorActionID)
|
|
buf.WriteString(err.Error())
|
|
buf.WriteRune('\000')
|
|
w.Write(buf.Bytes())
|
|
}
|
|
|
|
// WriteAnnounce encodes an announce response according to BEP 15.
|
|
func WriteAnnounce(w io.Writer, txID []byte, resp *bittorrent.AnnounceResponse) {
|
|
writeHeader(w, txID, announceActionID)
|
|
binary.Write(w, binary.BigEndian, uint32(resp.Interval/time.Second))
|
|
binary.Write(w, binary.BigEndian, uint32(resp.Incomplete))
|
|
binary.Write(w, binary.BigEndian, uint32(resp.Complete))
|
|
|
|
for _, peer := range resp.IPv4Peers {
|
|
w.Write(peer.IP)
|
|
binary.Write(w, binary.BigEndian, peer.Port)
|
|
}
|
|
}
|
|
|
|
// WriteScrape encodes a scrape response according to BEP 15.
|
|
func WriteScrape(w io.Writer, txID []byte, resp *bittorrent.ScrapeResponse) {
|
|
writeHeader(w, txID, scrapeActionID)
|
|
|
|
for _, scrape := range resp.Files {
|
|
binary.Write(w, binary.BigEndian, scrape.Complete)
|
|
binary.Write(w, binary.BigEndian, scrape.Snatches)
|
|
binary.Write(w, binary.BigEndian, scrape.Incomplete)
|
|
}
|
|
}
|
|
|
|
// WriteConnectionID encodes a new connection response according to BEP 15.
|
|
func WriteConnectionID(w io.Writer, txID, connID []byte) {
|
|
writeHeader(w, txID, connectActionID)
|
|
w.Write(connID)
|
|
}
|
|
|
|
// writeHeader writes the action and transaction ID to the provided response
|
|
// buffer.
|
|
func writeHeader(w io.Writer, txID []byte, action uint32) {
|
|
binary.Write(w, binary.BigEndian, action)
|
|
w.Write(txID)
|
|
}
|