rename frontends to frontend

frontend/http/parser.go

@@ -0,0 +1,151 @@
+// 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"
+	"net/http"
+
+	"github.com/jzelinskie/trakr/bittorrent"
+)
+
+// ParseAnnounce parses an bittorrent.AnnounceRequest from an http.Request.
+//
+// If allowIPSpoofing is true, IPs provided via params will be used.
+// If realIPHeader is not empty string, the first value of the HTTP Header with
+// that name will be used.
+func ParseAnnounce(r *http.Request, realIPHeader string, allowIPSpoofing bool) (*bittorrent.AnnounceRequest, error) {
+	qp, err := NewQueryParams(r.URL.RawQuery)
+	if err != nil {
+		return nil, err
+	}
+
+	request := &bittorrent.AnnounceRequest{Params: qp}
+
+	eventStr, _ := qp.String("event")
+	request.Event, err = bittorrent.NewEvent(eventStr)
+	if err != nil {
+		return nil, bittorrent.ClientError("failed to provide valid client event")
+	}
+
+	compactStr, _ := qp.String("compact")
+	request.Compact = compactStr != "" && compactStr != "0"
+
+	infoHashes := qp.InfoHashes()
+	if len(infoHashes) < 1 {
+		return nil, bittorrent.ClientError("no info_hash parameter supplied")
+	}
+	if len(infoHashes) > 1 {
+		return nil, bittorrent.ClientError("multiple info_hash parameters supplied")
+	}
+	request.InfoHash = infoHashes[0]
+
+	peerID, ok := qp.String("peer_id")
+	if !ok {
+		return nil, bittorrent.ClientError("failed to parse parameter: peer_id")
+	}
+	if len(peerID) != 20 {
+		return nil, bittorrent.ClientError("failed to provide valid peer_id")
+	}
+	request.Peer.ID = bittorrent.PeerIDFromString(peerID)
+
+	request.Left, err = qp.Uint64("left")
+	if err != nil {
+		return nil, bittorrent.ClientError("failed to parse parameter: left")
+	}
+
+	request.Downloaded, err = qp.Uint64("downloaded")
+	if err != nil {
+		return nil, bittorrent.ClientError("failed to parse parameter: downloaded")
+	}
+
+	request.Uploaded, err = qp.Uint64("uploaded")
+	if err != nil {
+		return nil, bittorrent.ClientError("failed to parse parameter: uploaded")
+	}
+
+	numwant, err := qp.Uint64("numwant")
+	if err != nil {
+		return nil, bittorrent.ClientError("failed to parse parameter: numwant")
+	}
+	request.NumWant = uint32(numwant)
+
+	port, err := qp.Uint64("port")
+	if err != nil {
+		return nil, bittorrent.ClientError("failed to parse parameter: port")
+	}
+	request.Peer.Port = uint16(port)
+
+	request.Peer.IP = requestedIP(r, qp, realIPHeader, allowIPSpoofing)
+	if request.Peer.IP == nil {
+		return nil, bittorrent.ClientError("failed to parse peer IP address")
+	}
+
+	return request, nil
+}
+
+// ParseScrape parses an bittorrent.ScrapeRequest from an http.Request.
+func ParseScrape(r *http.Request) (*bittorrent.ScrapeRequest, error) {
+	qp, err := NewQueryParams(r.URL.RawQuery)
+	if err != nil {
+		return nil, err
+	}
+
+	infoHashes := qp.InfoHashes()
+	if len(infoHashes) < 1 {
+		return nil, bittorrent.ClientError("no info_hash parameter supplied")
+	}
+
+	request := &bittorrent.ScrapeRequest{
+		InfoHashes: infoHashes,
+		Params:     qp,
+	}
+
+	return request, nil
+}
+
+// requestedIP determines the IP address for a BitTorrent client request.
+//
+// If allowIPSpoofing is true, IPs provided via params will be used.
+// If realIPHeader is not empty string, the first value of the HTTP Header with
+// that name will be used.
+func requestedIP(r *http.Request, p bittorrent.Params, realIPHeader string, allowIPSpoofing bool) net.IP {
+	if allowIPSpoofing {
+		if ipstr, ok := p.String("ip"); ok {
+			ip := net.ParseIP(ipstr)
+			return ip
+		}
+
+		if ipstr, ok := p.String("ipv4"); ok {
+			ip := net.ParseIP(ipstr)
+			return ip
+		}
+
+		if ipstr, ok := p.String("ipv6"); ok {
+			ip := net.ParseIP(ipstr)
+			return ip
+		}
+	}
+
+	if realIPHeader != "" {
+		if ips, ok := r.Header[realIPHeader]; ok && len(ips) > 0 {
+			ip := net.ParseIP(ips[0])
+			return ip
+		}
+	}
+
+	host, _, _ := net.SplitHostPort(r.RemoteAddr)
+	return net.ParseIP(host)
+}