Update and expose default client identifiers

diff --git a/cmd/torrent/main.go b/cmd/torrent/main.go
index bd5d6f7a80497f2a9c0e005f1dc08933bff1b752..61fd2ab2791cafc5ec80d2f5249181b02fe82f5e 100644 (file)
--- a/cmd/torrent/main.go
+++ b/cmd/torrent/main.go
@@ -18,6 +18,7 @@ import (
        "github.com/anacrolix/envpprof"
        "github.com/anacrolix/missinggo/v2"
        "github.com/anacrolix/torrent/bencode"
+       "github.com/anacrolix/torrent/version"
        "github.com/davecgh/go-spew/spew"
        "github.com/dustin/go-humanize"
        "golang.org/x/xerrors"
@@ -164,8 +165,11 @@ var flags struct {
        *ListFilesCmd     `arg:"subcommand:list-files"`
        *SpewBencodingCmd `arg:"subcommand:spew-bencoding"`
        *AnnounceCmd      `arg:"subcommand:announce"`
+       *VersionCmd       `arg:"subcommand:version"`
 }
 
+type VersionCmd struct{}
+
 type SpewBencodingCmd struct{}
 
 type DownloadCmd struct {
@@ -268,6 +272,11 @@ func mainErr() error {
                        spew.Dump(v)
                }
                return nil
+       case flags.VersionCmd != nil:
+               fmt.Printf("HTTP User-Agent: %q\n", version.DefaultHttpUserAgent)
+               fmt.Printf("Torrent client version: %q\n", version.DefaultExtendedHandshakeClientVersion)
+               fmt.Printf("Torrent version prefix: %q\n", version.DefaultBep20Prefix)
+               return nil
        default:
                p.Fail(fmt.Sprintf("unexpected subcommand: %v", p.Subcommand()))
                panic("unreachable")

diff --git a/config.go b/config.go
index 03d85c06eb4d0d53cc4ab68f20b91acde85382b8..c7720a0d5ea9f0191e8f7dd5284dbde6d693679a 100644 (file)
--- a/config.go
+++ b/config.go
@@ -9,8 +9,9 @@ import (
        "github.com/anacrolix/dht/v2"
        "github.com/anacrolix/dht/v2/krpc"
        "github.com/anacrolix/log"
-       "github.com/anacrolix/missinggo/v2"
        "github.com/anacrolix/missinggo/expect"
+       "github.com/anacrolix/missinggo/v2"
+       "github.com/anacrolix/torrent/version"
        "golang.org/x/time/rate"
 
        "github.com/anacrolix/torrent/iplist"
@@ -157,10 +158,10 @@ func (cfg *ClientConfig) SetListenAddr(addr string) *ClientConfig {
 
 func NewDefaultClientConfig() *ClientConfig {
        cc := &ClientConfig{
-               HTTPUserAgent:                  "Go-Torrent/1.0",
-               ExtendedHandshakeClientVersion: "go.torrent dev 20181121",
-               Bep20:                          "-GT0002-",
-               UpnpID:                         "anacrolix/torrent",
+               HTTPUserAgent:                  version.DefaultHttpUserAgent,
+               ExtendedHandshakeClientVersion: version.DefaultExtendedHandshakeClientVersion,
+               Bep20:                          version.DefaultBep20Prefix,
+               UpnpID:                         version.DefaultUpnpId,
                NominalDialTimeout:             20 * time.Second,
                MinDialTimeout:                 3 * time.Second,
                EstablishedConnsPerTorrent:     50,

diff --git a/tracker/http/http.go b/tracker/http/http.go
index c4f2fac4463e3a679240e94b98088286f0555b9b..15306ca974eaa0656318ab4eab533dbd9ad4f35c 100644 (file)
--- a/tracker/http/http.go
+++ b/tracker/http/http.go
@@ -16,6 +16,7 @@ import (
        "github.com/anacrolix/torrent/bencode"
        "github.com/anacrolix/torrent/tracker/shared"
        "github.com/anacrolix/torrent/tracker/udp"
+       "github.com/anacrolix/torrent/version"
 )
 
 var vars = expvar.NewMap("tracker/http")
@@ -76,7 +77,13 @@ func (cl Client) Announce(ctx context.Context, ar AnnounceRequest, opt AnnounceO
        _url := httptoo.CopyURL(cl.url_)
        setAnnounceParams(_url, &ar, opt)
        req, err := http.NewRequestWithContext(ctx, http.MethodGet, _url.String(), nil)
-       req.Header.Set("User-Agent", opt.UserAgent)
+       userAgent := opt.UserAgent
+       if userAgent == "" {
+               userAgent = version.DefaultHttpUserAgent
+       }
+       if userAgent != "" {
+               req.Header.Set("User-Agent", userAgent)
+       }
        req.Host = opt.HostHeader
        resp, err := cl.hc.Do(req)
        if err != nil {

diff --git a/version/version.go b/version/version.go
new file mode 100644 (file)
index 0000000..3d3ae55
--- /dev/null
+++ b/version/version.go
@@ -0,0 +1,58 @@
+// Package version provides default versions, user-agents etc. for client identification.
+package version
+
+import (
+       "fmt"
+       "reflect"
+       "runtime/debug"
+)
+
+var (
+       DefaultExtendedHandshakeClientVersion string
+       // This should be updated when client behaviour changes in a way that other peers could care
+       // about.
+       DefaultBep20Prefix   = "-GT0003-"
+       DefaultHttpUserAgent string
+       DefaultUpnpId        string
+)
+
+func init() {
+       const (
+               longNamespace   = "anacrolix"
+               longPackageName = "torrent"
+       )
+       type Newtype struct{}
+       var newtype Newtype
+       thisPkg := reflect.TypeOf(newtype).PkgPath()
+       var (
+               mainPath       = "unknown"
+               mainVersion    = "unknown"
+               torrentVersion = "unknown"
+       )
+       if buildInfo, ok := debug.ReadBuildInfo(); ok {
+               mainPath = buildInfo.Main.Path
+               mainVersion = buildInfo.Main.Version
+               // Note that if the main module is the same as this module, we get a version of "(devel)".
+               for _, dep := range append(buildInfo.Deps, &buildInfo.Main) {
+                       if dep.Path == thisPkg {
+                               torrentVersion = dep.Version
+                       }
+               }
+       }
+       DefaultExtendedHandshakeClientVersion = fmt.Sprintf(
+               "%v %v (%v/%v %v)",
+               mainPath,
+               mainVersion,
+               longNamespace,
+               longPackageName,
+               torrentVersion,
+       )
+       DefaultUpnpId = fmt.Sprintf("%v %v", mainPath, mainVersion)
+       // Per https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/User-Agent#library_and_net_tool_ua_strings
+       DefaultHttpUserAgent = fmt.Sprintf(
+               "%v-%v/%v",
+               longNamespace,
+               longPackageName,
+               torrentVersion,
+       )
+}