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Implement the WHIP protocol.

This commit is contained in:
Juliusz Chroboczek 2023-07-10 16:24:30 +02:00
parent 90e2de0b2d
commit 1e050fa4e3
4 changed files with 644 additions and 0 deletions

213
rtpconn/whipclient.go Normal file
View file

@ -0,0 +1,213 @@
package rtpconn
import (
"context"
"errors"
"sync"
"github.com/jech/galene/conn"
"github.com/jech/galene/group"
"github.com/pion/webrtc/v3"
)
type WhipClient struct {
group *group.Group
id string
token string
username string
mu sync.Mutex
permissions []string
connection *rtpUpConnection
}
func NewWhipClient(g *group.Group, id string, token string) *WhipClient {
return &WhipClient{group: g, id: id, token: token}
}
func (c *WhipClient) Group() *group.Group {
return c.group
}
func (c *WhipClient) Id() string {
return c.id
}
func (c *WhipClient) Token() string {
return c.token
}
func (c *WhipClient) Username() string {
return c.username
}
func (c *WhipClient) SetUsername(username string) {
c.username = username
}
func (c *WhipClient) Permissions() []string {
c.mu.Lock()
defer c.mu.Unlock()
return c.permissions
}
func (c *WhipClient) SetPermissions(perms []string) {
c.mu.Lock()
defer c.mu.Unlock()
c.permissions = perms
}
func (c *WhipClient) Data() map[string]interface{} {
return nil
}
func (c *WhipClient) PushConn(g *group.Group, id string, conn conn.Up, tracks []conn.UpTrack, replace string) error {
return nil
}
func (c *WhipClient) RequestConns(target group.Client, g *group.Group, id string) error {
if g != c.group {
return nil
}
c.mu.Lock()
up := c.connection
c.mu.Unlock()
if up == nil {
return nil
}
tracks := up.getTracks()
ts := make([]conn.UpTrack, len(tracks))
for i, t := range tracks {
ts[i] = t
}
target.PushConn(g, up.Id(), up, ts, "")
return nil
}
func (c *WhipClient) Joined(group, kind string) error {
return nil
}
func (c *WhipClient) PushClient(group, kind, id, username string, permissions []string, status map[string]interface{}) error {
return nil
}
func (c *WhipClient) Kick(id string, user *string, message string) error {
return c.Close()
}
func (c *WhipClient) Close() error {
c.mu.Lock()
defer c.mu.Unlock()
g := c.group
if g == nil {
return nil
}
if c.connection != nil {
id := c.connection.Id()
c.connection.pc.OnICEConnectionStateChange(nil)
c.connection.pc.Close()
c.connection = nil
for _, c := range g.GetClients(c) {
c.PushConn(g, id, nil, nil, "")
}
c.connection = nil
}
group.DelClient(c)
c.group = nil
return nil
}
func (c *WhipClient) NewConnection(ctx context.Context, offer []byte) ([]byte, error) {
conn, err := newUpConn(c, c.id, "", string(offer))
if err != nil {
return nil, err
}
conn.pc.OnICEConnectionStateChange(
func(state webrtc.ICEConnectionState) {
switch state {
case webrtc.ICEConnectionStateFailed,
webrtc.ICEConnectionStateClosed:
c.Close()
}
})
c.mu.Lock()
defer c.mu.Unlock()
if c.connection != nil {
conn.pc.OnICEConnectionStateChange(nil)
conn.pc.Close()
return nil, errors.New("duplicate connection")
}
c.connection = conn
answer, err := c.gotOffer(ctx, offer)
if err != nil {
conn.pc.OnICEConnectionStateChange(nil)
conn.pc.Close()
return nil, err
}
return answer, nil
}
func (c *WhipClient) GotOffer(ctx context.Context, offer []byte) ([]byte, error) {
c.mu.Lock()
defer c.mu.Unlock()
return c.gotOffer(ctx, offer)
}
// called locked
func (c *WhipClient) gotOffer(ctx context.Context, offer []byte) ([]byte, error) {
conn := c.connection
err := conn.pc.SetRemoteDescription(webrtc.SessionDescription{
Type: webrtc.SDPTypeOffer,
SDP: string(offer),
})
if err != nil {
return nil, err
}
answer, err := conn.pc.CreateAnswer(nil)
if err != nil {
return nil, err
}
gatherComplete := webrtc.GatheringCompletePromise(conn.pc)
err = conn.pc.SetLocalDescription(answer)
if err != nil {
return nil, err
}
conn.flushICECandidates()
select {
case <-ctx.Done():
return nil, ctx.Err()
case <-gatherComplete:
}
return []byte(conn.pc.CurrentLocalDescription().SDP), nil
}
func (c *WhipClient) GotICECandidate(candidate, ufrag []byte) error {
zero := uint16(0)
init := webrtc.ICECandidateInit{
Candidate: string(candidate),
SDPMLineIndex: &zero,
}
if ufrag != nil {
u := string(ufrag)
init.UsernameFragment = &u
}
c.mu.Lock()
defer c.mu.Unlock()
if c.connection == nil {
return nil
}
return c.connection.addICECandidate(&init)
}

View file

@ -304,6 +304,16 @@ func groupHandler(w http.ResponseWriter, r *http.Request) {
return
}
dir, id := parseWhip(r.URL.Path)
if dir != "" {
if id == "" {
whipEndpointHandler(w, r)
} else {
whipResourceHandler(w, r)
}
return
}
name := parseGroupName("/group/", r.URL.Path)
if name == "" {
notFound(w)

View file

@ -2,6 +2,8 @@ package webserver
import (
"testing"
"github.com/pion/webrtc/v3"
)
func TestParseGroupName(t *testing.T) {
@ -29,3 +31,79 @@ func TestParseGroupName(t *testing.T) {
})
}
}
func TestParseWhip(t *testing.T) {
a := []struct{ p, d, b string }{
{"", "", ""},
{"/", "", ""},
{"/foo", "", ""},
{"/foo/", "", ""},
{"/foo/bar", "", ""},
{"/foo/bar/", "", ""},
{"/foo/bar/baz", "", ""},
{"/foo/bar/baz/", "", ""},
{"/foo/.whip", "/foo/", ""},
{"/foo/.whip/", "/foo/", ""},
{"/foo/.whip/bar", "/foo/", "bar"},
{"/foo/.whip/bar/", "/foo/", "bar"},
{"/foo/.whip/bar/baz", "", ""},
{"/foo/.whip/bar/baz/", "", ""},
}
for _, pdb := range a {
t.Run(pdb.p, func(t *testing.T) {
d, b := parseWhip(pdb.p)
if d != pdb.d || b != pdb.b {
t.Errorf("Path %v, got %v %v, expected %v %v",
pdb.p, d, b, pdb.d, pdb.b)
}
})
}
}
func TestFormatICEServer(t *testing.T) {
a := []struct {
s webrtc.ICEServer
v string
}{
{
webrtc.ICEServer{
URLs: []string{"stun:stun.example.org:3478"},
}, "<stun:stun.example.org:3478>; rel=\"ice-server\"",
},
{
webrtc.ICEServer{
URLs: []string{"turn:turn.example.org:3478"},
Username: "toto",
Credential: "titi",
CredentialType: webrtc.ICECredentialTypePassword,
}, "<turn:turn.example.org:3478>; rel=\"ice-server\"; " +
"username=\"toto\"; credential=\"titi\"; " +
"credential-type=\"password\"",
},
{
webrtc.ICEServer{
URLs: []string{"turns:turn.example.org:5349"},
Username: "toto",
Credential: "titi",
CredentialType: webrtc.ICECredentialTypePassword,
}, "<turns:turn.example.org:5349>; rel=\"ice-server\"; " +
"username=\"toto\"; credential=\"titi\"; " +
"credential-type=\"password\"",
},
{
webrtc.ICEServer{
URLs: []string{"https://stun.example.org"},
}, "",
},
}
for _, sv := range a {
t.Run(sv.s.URLs[0], func(t *testing.T) {
v := formatICEServer(sv.s, sv.s.URLs[0])
if v != sv.v {
t.Errorf("Got %v, expected %v", v, sv.v)
}
})
}
}

343
webserver/whip.go Normal file
View file

@ -0,0 +1,343 @@
package webserver
import (
"bytes"
crand "crypto/rand"
"encoding/base64"
"errors"
"fmt"
"io"
"log"
"net/http"
"net/url"
"os"
"path"
"strings"
"github.com/pion/webrtc/v3"
"github.com/jech/galene/group"
"github.com/jech/galene/ice"
"github.com/jech/galene/rtpconn"
)
func parseWhip(pth string) (string, string) {
if pth != "/" {
pth = strings.TrimSuffix(pth, "/")
}
dir := path.Dir(pth)
base := path.Base(pth)
if base == ".whip" {
return dir + "/", ""
}
if path.Base(dir) == ".whip" {
return path.Dir(dir) + "/", base
}
return "", ""
}
func newId() string {
b := make([]byte, 16)
crand.Read(b)
return base64.RawURLEncoding.EncodeToString(b)
}
const sdpLimit = 1024 * 1024
func readLimited(r io.Reader) ([]byte, error) {
v, err := io.ReadAll(io.LimitReader(r, sdpLimit))
if len(v) == sdpLimit {
err = errors.New("SDP too large")
}
return v, err
}
func canPresent(perms []string) bool {
for _, p := range perms {
if p == "present" {
return true
}
}
return false
}
func getBearerToken(r *http.Request) string {
auth := r.Header.Get("Authorization")
auths := strings.Split(auth, ",")
for _, a := range auths {
a = strings.Trim(a, " \t")
s := strings.Split(a, " ")
if len(s) == 2 && strings.EqualFold(s[0], "bearer") {
return s[1]
}
}
return ""
}
var iceServerReplacer = strings.NewReplacer(`\`, `\\`, `"`, `\"`)
func formatICEServer(server webrtc.ICEServer, u string) string {
quote := func(s string) string {
return iceServerReplacer.Replace(s)
}
uu, err := url.Parse(u)
if err != nil {
return ""
}
if strings.EqualFold(uu.Scheme, "stun") {
return fmt.Sprintf("<%v>; rel=\"ice-server\"", u)
} else if strings.EqualFold(uu.Scheme, "turn") ||
strings.EqualFold(uu.Scheme, "turns") {
pw, ok := server.Credential.(string)
if !ok {
return ""
}
return fmt.Sprintf("<%v>; rel=\"ice-server\"; "+
"username=\"%v\"; "+
"credential=\"%v\"; "+
"credential-type=\"%v\"",
u,
quote(server.Username),
quote(pw),
quote(server.CredentialType.String()))
}
return ""
}
func whipICEServers(w http.ResponseWriter) {
conf := ice.ICEConfiguration()
for _, server := range conf.ICEServers {
for _, u := range server.URLs {
v := formatICEServer(server, u)
if v != "" {
w.Header().Add("Link", v)
}
}
}
}
func whipEndpointHandler(w http.ResponseWriter, r *http.Request) {
if redirect(w, r) {
return
}
pth, pthid := parseWhip(r.URL.Path)
if pthid != "" {
http.Error(w, "Internal server error",
http.StatusInternalServerError)
return
}
name := parseGroupName("/group/", pth)
if name == "" {
notFound(w)
return
}
g, err := group.Add(name, nil)
if err != nil {
if os.IsNotExist(err) {
notFound(w)
return
}
log.Printf("group.Add: %v", err)
http.Error(w, "Internal server error",
http.StatusInternalServerError)
return
}
conf, err := group.GetConfiguration()
if err != nil {
http.Error(w, "Internal server error",
http.StatusInternalServerError)
return
}
if conf.PublicServer {
w.Header().Set("Access-Control-Allow-Origin", "*")
}
if r.Method == "OPTIONS" {
w.Header().Set("Access-Control-Allow-Methods", "OPTIONS, POST")
w.Header().Set("Access-Control-Allow-Headers",
"Authorization, Content-Type",
)
w.Header().Set("Access-Control-Expose-Headers", "Link")
whipICEServers(w)
return
}
if r.Method != "POST" {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
return
}
ctype := r.Header.Get("content-type")
if !strings.EqualFold(ctype, "application/sdp") {
http.Error(w, "bad content type", http.StatusBadRequest)
return
}
body, err := readLimited(r.Body)
if err != nil {
httpError(w, err)
return
}
token := getBearerToken(r)
whip := "whip"
creds := group.ClientCredentials{
Username: &whip,
Token: token,
}
id := newId()
c := rtpconn.NewWhipClient(g, id, token)
_, err = group.AddClient(g.Name(), c, creds)
if err == group.ErrNotAuthorised ||
err == group.ErrAnonymousNotAuthorised {
http.Error(w, "Authentication failed", http.StatusUnauthorized)
return
} else if err != nil {
log.Printf("WHIP: %v", err)
http.Error(w, "Internal Server Error",
http.StatusInternalServerError)
return
}
if !canPresent(c.Permissions()) {
group.DelClient(c)
http.Error(w, "Forbidden", http.StatusForbidden)
return
}
answer, err := c.NewConnection(r.Context(), body)
if err != nil {
group.DelClient(c)
log.Printf("WHIP offer: %v", err)
http.Error(w, "Internal Server Error",
http.StatusInternalServerError)
}
w.Header().Set("Location", path.Join(r.URL.Path, id))
w.Header().Set("Access-Control-Expose-Headers",
"Location, Content-Type, Link")
whipICEServers(w)
w.Header().Set("Content-Type", "application/sdp")
w.WriteHeader(http.StatusCreated)
w.Write(answer)
return
}
func whipResourceHandler(w http.ResponseWriter, r *http.Request) {
pth, id := parseWhip(r.URL.Path)
if pth == "" || id == "" {
http.Error(w, "Internal server error",
http.StatusInternalServerError)
return
}
name := parseGroupName("/group/", pth)
if name == "" {
notFound(w)
return
}
g := group.Get(name)
if g == nil {
notFound(w)
return
}
cc := g.GetClient(id)
if cc == nil {
notFound(w)
return
}
c, ok := cc.(*rtpconn.WhipClient)
if !ok {
notFound(w)
return
}
if t := c.Token(); t != "" {
token := getBearerToken(r)
if token != t {
http.Error(w, "Forbidden", http.StatusForbidden)
return
}
}
conf, err := group.GetConfiguration()
if err != nil {
http.Error(w, "Internal server error",
http.StatusInternalServerError)
return
}
if conf.PublicServer {
w.Header().Set("Access-Control-Allow-Origin", "*")
}
if r.Method == "OPTIONS" {
w.Header().Set("Access-Control-Allow-Methods",
"OPTIONS, PATCH, DELETE",
)
w.Header().Set("Access-Control-Allow-Headers",
"Authorization, Content-Type",
)
return
}
if r.Method == "DELETE" {
c.Close()
return
}
if r.Method != "PATCH" {
http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
}
ctype := r.Header.Get("content-type")
if !strings.EqualFold(ctype, "application/trickle-ice-sdpfrag") {
http.Error(w, "bad content type", http.StatusBadRequest)
return
}
body, err := readLimited(r.Body)
if err != nil {
httpError(w, err)
return
}
if len(body) < 2 {
http.Error(w, "SDP truncated", http.StatusBadRequest)
return
}
// RFC 8840
lines := bytes.Split(body, []byte{'\n'})
var ufrag []byte
for _, l := range lines {
l = bytes.TrimRight(l, " \r")
if bytes.HasPrefix(l, []byte("a=ice-ufrag:")) {
ufrag = l[len("a=ice-ufrag:"):]
} else if bytes.HasPrefix(l, []byte("a=candidate:")) {
err := c.GotICECandidate(l[2:], ufrag)
if err != nil {
log.Printf("WHIP candidate: %v", err)
}
} else if bytes.Equal(l, []byte("a=end-of-candidates")) {
c.GotICECandidate(nil, ufrag)
}
}
w.WriteHeader(http.StatusNoContent)
return
}