initial foundation

Definitely doesn't work, certainly has the right ideas.

bittorrent/http/parser.go

@@ -0,0 +1,168 @@
+// 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: q}
+
+	eventStr, err := qp.String("event")
+	if err == query.ErrKeyNotFound {
+		eventStr = ""
+	} else if err != nil {
+		return nil, bittorrent.ClientError("failed to parse parameter: 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, err := qp.String("peer_id")
+	if err != nil {
+		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.PeerID = 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, _ := qp.Uint64("numwant")
+	request.NumWant = int32(numwant)
+
+	port, err := qp.Uint64("port")
+	if err != nil {
+		return nil, bittorrent.ClientError("failed to parse parameter: port")
+	}
+	request.Port = uint16(port)
+
+	request.IP, err = requestedIP(q, r, realIPHeader, allowIPSpoofing)
+	if err != nil {
+		return nil, bittorrent.ClientError("failed to parse peer IP address: " + err.Error())
+	}
+
+	return request, nil
+}
+
+// ParseScrape parses an bittorrent.ScrapeRequest from an http.Request.
+func ParseScrape(r *http.Request) (*bittorent.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:     q,
+	}
+
+	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 bittorent.Params, realIPHeader string, allowIPSpoofing bool) (net.IP, error) {
+	if allowIPSpoofing {
+		if ipstr, err := p.String("ip"); err == nil {
+			ip, err := net.ParseIP(str)
+			if err != nil {
+				return nil, err
+			}
+
+			return ip, nil
+		}
+
+		if ipstr, err := p.String("ipv4"); err == nil {
+			ip, err := net.ParseIP(str)
+			if err != nil {
+				return nil, err
+			}
+
+			return ip, nil
+		}
+
+		if ipstr, err := p.String("ipv6"); err == nil {
+			ip, err := net.ParseIP(str)
+			if err != nil {
+				return nil, err
+			}
+
+			return ip, nil
+		}
+	}
+
+	if realIPHeader != "" {
+		if ips, ok := r.Header[realIPHeader]; ok && len(ips) > 0 {
+			ip, err := net.ParseIP(ips[0])
+			if err != nil {
+				return nil, err
+			}
+
+			return ip, nil
+		}
+	}
+
+	return r.RemoteAddr
+}

bittorrent/http/query_params.go

@@ -0,0 +1,141 @@
+// 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 (
+	"errors"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/jzelinskie/trakr/bittorrent"
+)
+
+// ErrKeyNotFound is returned when a provided key has no value associated with
+// it.
+var ErrKeyNotFound = errors.New("http: value for the provided key does not exist")
+
+// ErrInvalidInfohash is returned when parsing a query encounters an infohash
+// with invalid length.
+var ErrInvalidInfohash = errors.New("http: invalid infohash")
+
+// QueryParams parses an HTTP Query and implements the bittorrent.Params
+// interface with some additional helpers.
+type QueryParams struct {
+	query      string
+	params     map[string]string
+	infoHashes []bittorrent.InfoHash
+}
+
+// NewQueryParams parses a raw URL query.
+func NewQueryParams(query string) (*Query, error) {
+	var (
+		keyStart, keyEnd int
+		valStart, valEnd int
+
+		onKey = true
+
+		q = &Query{
+			query:      query,
+			infoHashes: nil,
+			params:     make(map[string]string),
+		}
+	)
+
+	for i, length := 0, len(query); i < length; i++ {
+		separator := query[i] == '&' || query[i] == ';' || query[i] == '?'
+		last := i == length-1
+
+		if separator || last {
+			if onKey && !last {
+				keyStart = i + 1
+				continue
+			}
+
+			if last && !separator && !onKey {
+				valEnd = i
+			}
+
+			keyStr, err := url.QueryUnescape(query[keyStart : keyEnd+1])
+			if err != nil {
+				return nil, err
+			}
+
+			var valStr string
+
+			if valEnd > 0 {
+				valStr, err = url.QueryUnescape(query[valStart : valEnd+1])
+				if err != nil {
+					return nil, err
+				}
+			}
+
+			if keyStr == "info_hash" {
+				if len(valStr) != 20 {
+					return nil, ErrInvalidInfohash
+				}
+				q.infoHashes = append(q.infoHashes, bittorrent.InfoHashFromString(valStr))
+			} else {
+				q.params[strings.ToLower(keyStr)] = valStr
+			}
+
+			valEnd = 0
+			onKey = true
+			keyStart = i + 1
+
+		} else if query[i] == '=' {
+			onKey = false
+			valStart = i + 1
+			valEnd = 0
+		} else if onKey {
+			keyEnd = i
+		} else {
+			valEnd = i
+		}
+	}
+
+	return q, nil
+}
+
+// String returns a string parsed from a query. Every key can be returned as a
+// string because they are encoded in the URL as strings.
+func (q *Query) String(key string) (string, error) {
+	val, exists := q.params[key]
+	if !exists {
+		return "", ErrKeyNotFound
+	}
+	return val, nil
+}
+
+// Uint64 returns a uint parsed from a query. After being called, it is safe to
+// cast the uint64 to your desired length.
+func (q *Query) Uint64(key string) (uint64, error) {
+	str, exists := q.params[key]
+	if !exists {
+		return 0, ErrKeyNotFound
+	}
+
+	val, err := strconv.ParseUint(str, 10, 64)
+	if err != nil {
+		return 0, err
+	}
+
+	return val, nil
+}
+
+// InfoHashes returns a list of requested infohashes.
+func (q *Query) InfoHashes() []bittorrent.InfoHash {
+	return q.infoHashes
+}

bittorrent/http/query_params_test.go

@@ -0,0 +1,110 @@
+// 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/url"
+	"testing"
+)
+
+var (
+	baseAddr     = "https://www.subdomain.tracker.com:80/"
+	testInfoHash = "01234567890123456789"
+	testPeerID   = "-TEST01-6wfG2wk6wWLc"
+
+	ValidAnnounceArguments = []url.Values{
+		{"peer_id": {testPeerID}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}},
+		{"peer_id": {testPeerID}, "ip": {"192.168.0.1"}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}},
+		{"peer_id": {testPeerID}, "ip": {"192.168.0.1"}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}, "numwant": {"28"}},
+		{"peer_id": {testPeerID}, "ip": {"192.168.0.1"}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}, "event": {"stopped"}},
+		{"peer_id": {testPeerID}, "ip": {"192.168.0.1"}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}, "event": {"started"}, "numwant": {"13"}},
+		{"peer_id": {testPeerID}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}, "no_peer_id": {"1"}},
+		{"peer_id": {testPeerID}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}, "compact": {"0"}, "no_peer_id": {"1"}},
+		{"peer_id": {testPeerID}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}, "compact": {"0"}, "no_peer_id": {"1"}, "key": {"peerKey"}},
+		{"peer_id": {testPeerID}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}, "compact": {"0"}, "no_peer_id": {"1"}, "key": {"peerKey"}, "trackerid": {"trackerId"}},
+		{"peer_id": {"%3Ckey%3A+0x90%3E"}, "port": {"6881"}, "downloaded": {"1234"}, "left": {"4321"}, "compact": {"0"}, "no_peer_id": {"1"}, "key": {"peerKey"}, "trackerid": {"trackerId"}},
+		{"peer_id": {"%3Ckey%3A+0x90%3E"}, "compact": {"1"}},
+		{"peer_id": {""}, "compact": {""}},
+	}
+
+	InvalidQueries = []string{
+		baseAddr + "announce/?" + "info_hash=%0%a",
+	}
+)
+
+func mapArrayEqual(boxed map[string][]string, unboxed map[string]string) bool {
+	if len(boxed) != len(unboxed) {
+		return false
+	}
+
+	for mapKey, mapVal := range boxed {
+		// Always expect box to hold only one element
+		if len(mapVal) != 1 || mapVal[0] != unboxed[mapKey] {
+			return false
+		}
+	}
+
+	return true
+}
+
+func TestValidQueries(t *testing.T) {
+	for parseIndex, parseVal := range ValidAnnounceArguments {
+		parsedQueryObj, err := NewQueryParams(baseAddr + "announce/?" + parseVal.Encode())
+		if err != nil {
+			t.Error(err)
+		}
+
+		if !mapArrayEqual(parseVal, parsedQueryObj.params) {
+			t.Errorf("Incorrect parse at item %d.\n Expected=%v\n Recieved=%v\n", parseIndex, parseVal, parsedQueryObj.params)
+		}
+	}
+}
+
+func TestInvalidQueries(t *testing.T) {
+	for parseIndex, parseStr := range InvalidQueries {
+		parsedQueryObj, err := NewQueryParams(parseStr)
+		if err == nil {
+			t.Error("Should have produced error", parseIndex)
+		}
+
+		if parsedQueryObj != nil {
+			t.Error("Should be nil after error", parsedQueryObj, parseIndex)
+		}
+	}
+}
+
+func BenchmarkParseQuery(b *testing.B) {
+	for bCount := 0; bCount < b.N; bCount++ {
+		for parseIndex, parseStr := range ValidAnnounceArguments {
+			parsedQueryObj, err := NewQueryParams(baseAddr + "announce/?" + parseStr.Encode())
+			if err != nil {
+				b.Error(err, parseIndex)
+				b.Log(parsedQueryObj)
+			}
+		}
+	}
+}
+
+func BenchmarkURLParseQuery(b *testing.B) {
+	for bCount := 0; bCount < b.N; bCount++ {
+		for parseIndex, parseStr := range ValidAnnounceArguments {
+			parsedQueryObj, err := url.ParseQuery(baseAddr + "announce/?" + parseStr.Encode())
+			if err != nil {
+				b.Error(err, parseIndex)
+				b.Log(parsedQueryObj)
+			}
+		}
+	}
+}

bittorrent/http/server.go

@@ -0,0 +1,136 @@
+// 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
+
+type Config struct {
+	Addr            string
+	ReadTimeout     time.Duration
+	WriteTimeout    time.Duration
+	RequestTimeout  time.Duration
+	AllowIPSpoofing bool
+	RealIPHeader    string
+}
+
+type Server struct {
+	grace *graceful.Server
+
+	bittorrent.ServerFuncs
+	Config
+}
+
+func NewServer(funcs bittorrent.ServerFuncs, cfg Config) {
+	return &Server{
+		ServerFuncs: funcs,
+		Config:      cfg,
+	}
+}
+
+func (s *Server) Stop() {
+	s.grace.Stop(s.grace.Timeout)
+	<-s.grace.StopChan()
+}
+
+func (s *Server) handler() {
+	router := httprouter.New()
+	router.GET("/announce", s.announceRoute)
+	router.GET("/scrape", s.scrapeRoute)
+	return server
+}
+
+func (s *Server) ListenAndServe() error {
+	s.grace = &graceful.Server{
+		Server: &http.Server{
+			Addr:         s.Addr,
+			Handler:      s.handler(),
+			ReadTimeout:  s.ReadTimeout,
+			WriteTimeout: s.WriteTimeout,
+		},
+		Timeout:          s.RequestTimeout,
+		NoSignalHandling: true,
+		ConnState: func(conn net.Conn, state http.ConnState) {
+			switch state {
+			case http.StateNew:
+				//stats.RecordEvent(stats.AcceptedConnection)
+
+			case http.StateClosed:
+				//stats.RecordEvent(stats.ClosedConnection)
+
+			case http.StateHijacked:
+				panic("http: connection impossibly hijacked")
+
+			// Ignore the following cases.
+			case http.StateActive, http.StateIdle:
+
+			default:
+				panic("http: connection transitioned to unknown state")
+			}
+		},
+	}
+	s.grace.SetKeepAlivesEnabled(false)
+
+	if err := s.grace.ListenAndServe(); err != nil {
+		if opErr, ok := err.(*net.OpError); !ok || (ok && opErr.Op != "accept") {
+			panic("http: failed to gracefully run HTTP server: " + err.Error())
+		}
+	}
+}
+
+func (s *Server) announceRoute(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
+	req, err := ParseAnnounce(r, s.RealIPHeader, s.AllowIPSpoofing)
+	if err != nil {
+		WriteError(w, err)
+		return
+	}
+
+	resp, err := s.HandleAnnounce(req)
+	if err != nil {
+		WriteError(w, err)
+		return
+	}
+
+	err = WriteAnnounceResponse(w, resp)
+	if err != nil {
+		WriteError(w, err)
+		return
+	}
+
+	if s.AfterAnnounce != nil {
+		s.AfterAnnounce(req, resp)
+	}
+}
+
+func (s *Server) scrapeRoute(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
+	req, err := ParseScrape(r)
+	if err != nil {
+		WriteError(w, err)
+		return
+	}
+
+	resp, err := s.HandleScrape(req)
+	if err != nil {
+		WriteError(w, err)
+		return
+	}
+
+	err = WriteScrapeResponse(w, resp)
+	if err != nil {
+		WriteError(w, err)
+		return
+	}
+
+	if s.AfterScrape != nil {
+		s.AfterScrape(req, resp)
+	}
+}

bittorrent/http/writer.go

@@ -0,0 +1,111 @@
+// 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"
+)
+
+// 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,
+	}
+}

bittorrent/http/writer_test.go

@@ -0,0 +1,46 @@
+// 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/httptest"
+	"testing"
+
+	"github.com/jzelinskie/trakr/bittorrent"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestWriteError(t *testing.T) {
+	var table = []struct {
+		reason, expected string
+	}{
+		{"hello world", "d14:failure reason11:hello worlde"},
+		{"what's up", "d14:failure reason9:what's upe"},
+	}
+
+	for _, tt := range table {
+		r := httptest.NewRecorder()
+		err := writeError(r, bittorrent.ClientError(tt.reason))
+		assert.Nil(t, err)
+		assert.Equal(t, r.Body.String(), tt.expected)
+	}
+}
+
+func TestWriteStatus(t *testing.T) {
+	r := httptest.NewRecorder()
+	err := writeError(r, bittorrent.ClientError("something is missing"))
+	assert.Nil(t, err)
+	assert.Equal(t, r.Body.String(), "d14:failure reason20:something is missinge")
+}