Implement file sending via Jingle

This is still disabled by default until prioritization is implemented;
otherwise this could be preferred to HTTP uploads.

File sending only works via Jingle In-Band-Bytestreams right now, more
transports are going to be implemented.

To test this, uncomment the line with `JingleFileTransfer` in
libdino/src/application.vala.

5 files changed, 677 insertions, 2 deletions

diff --git a/xmpp-vala/src/module/message/stanza.vala b/xmpp-vala/src/module/message/stanza.vala
index 640f2796..053c44dd 100644
--- a/xmpp-vala/src/module/message/stanza.vala
+++ b/xmpp-vala/src/module/message/stanza.vala
@@ -18,7 +18,7 @@ public class MessageStanza : Xmpp.Stanza {
     public string body {
         get {
             StanzaNode? body_node = stanza.get_subnode(NODE_BODY);
-            return body_node == null? null : body_node.get_string_content();
+            return body_node == null ? null : body_node.get_string_content();
         }
         set {
             StanzaNode? body_node = stanza.get_subnode(NODE_BODY);
@@ -65,4 +65,4 @@ public abstract class MessageFlag : Object {
     public abstract string get_id();
 }
 
-}
\ No newline at end of file
+}
diff --git a/xmpp-vala/src/module/xep/0047_in_band_bytestreams.vala b/xmpp-vala/src/module/xep/0047_in_band_bytestreams.vala
new file mode 100644
index 00000000..0e1dd6be
--- /dev/null
+++ b/xmpp-vala/src/module/xep/0047_in_band_bytestreams.vala
@@ -0,0 +1,172 @@
+using Gee;
+using Xmpp;
+using Xmpp.Xep;
+
+namespace Xmpp.Xep.InBandBytestreams {
+
+private const string NS_URI = "http://jabber.org/protocol/ibb";
+private const int SEQ_MODULUS = 65536;
+
+public class Module : XmppStreamModule {
+    public static Xmpp.ModuleIdentity<Module> IDENTITY = new Xmpp.ModuleIdentity<Module>(NS_URI, "0047_in_band_bytestreams");
+
+    public override void attach(XmppStream stream) {
+        stream.add_flag(new Flag());
+    }
+    public override void detach(XmppStream stream) { }
+
+    public void on_iq_set(XmppStream stream, Iq.Stanza iq) {
+        StanzaNode? data = iq.stanza.get_subnode("data", NS_URI);
+        string? sid = data != null ? data.get_attribute("sid") : null;
+        if (data == null || sid == null) {
+            stream.get_module(Iq.Module.IDENTITY).send_iq(stream, new Iq.Stanza.error(iq, new ErrorStanza.bad_request("missing data node or sid")));
+            return;
+        }
+        Connection? conn = stream.get_flag(Flag.IDENTITY).get_connection(sid);
+        if (conn == null) {
+            stream.get_module(Iq.Module.IDENTITY).send_iq(stream, new Iq.Stanza.error(iq, new ErrorStanza.item_not_found()));
+            return;
+        }
+
+        int seq = data.get_attribute_int("seq");
+        // TODO(hrxi): return an error on malformed base64 (need to do this
+        // according to the xep)
+        uint8[] content = Base64.decode(data.get_string_content());
+        if (seq < 0 || seq != conn.remote_seq) {
+            // TODO(hrxi): send an error and close the connection
+            return;
+        }
+        conn.remote_seq = (conn.remote_seq + 1) % SEQ_MODULUS;
+
+        stream.get_module(Iq.Module.IDENTITY).send_iq(stream, new Iq.Stanza.result(iq));
+        conn.on_data(stream, content);
+    }
+
+    public override string get_ns() { return NS_URI; }
+    public override string get_id() { return IDENTITY.id; }
+}
+
+public class Connection {
+    // TODO(hrxi): implement half-open states
+    public enum State {
+        UNCONNECTED,
+        CONNECTING,
+        CONNECTED,
+        DISCONNECTING,
+        DISCONNECTED,
+        ERROR,
+    }
+    State state = UNCONNECTED;
+    Jid receiver_full_jid;
+    public string sid { get; private set; }
+    int block_size;
+    int local_seq = 0;
+    int remote_ack = 0;
+    internal int remote_seq = 0;
+
+    public signal void on_error(XmppStream stream, string error);
+    public signal void on_data(XmppStream stream, uint8[] data);
+    public signal void on_ready(XmppStream stream);
+
+    public Connection(Jid receiver_full_jid, string sid, int block_size) {
+        this.receiver_full_jid = receiver_full_jid;
+        this.sid = sid;
+        this.block_size = block_size;
+    }
+
+    public void connect(XmppStream stream) {
+        assert(state == UNCONNECTED);
+        state = CONNECTING;
+
+        StanzaNode open = new StanzaNode.build("open", NS_URI)
+            .add_self_xmlns()
+            .put_attribute("block-size", block_size.to_string())
+            .put_attribute("sid", sid);
+
+        Iq.Stanza iq = new Iq.Stanza.set(open) { to=receiver_full_jid };
+        stream.get_module(Iq.Module.IDENTITY).send_iq(stream, iq, (stream, iq) => {
+            assert(state == CONNECTING);
+            if (!iq.is_error()) {
+                state = CONNECTED;
+                stream.get_flag(Flag.IDENTITY).add_connection(this);
+                on_ready(stream);
+            } else {
+                set_error(stream, "connection failed");
+            }
+        });
+    }
+
+    void set_error(XmppStream stream, string error) {
+        // TODO(hrxi): Send disconnect?
+        state = ERROR;
+        on_error(stream, error);
+    }
+
+    public void send(XmppStream stream, uint8[] bytes) {
+        assert(state == CONNECTED);
+        // TODO(hrxi): rate-limiting/merging?
+        int seq = local_seq;
+        local_seq = (local_seq + 1) % SEQ_MODULUS;
+        StanzaNode data = new StanzaNode.build("data", NS_URI)
+            .add_self_xmlns()
+            .put_attribute("sid", sid)
+            .put_attribute("seq", seq.to_string())
+            .put_node(new StanzaNode.text(Base64.encode(bytes)));
+        Iq.Stanza iq = new Iq.Stanza.set(data) { to=receiver_full_jid };
+        stream.get_module(Iq.Module.IDENTITY).send_iq(stream, iq, (stream, iq) => {
+            if (iq.is_error()) {
+                set_error(stream, "sending failed");
+                return;
+            }
+            if (remote_ack != seq) {
+                set_error(stream, "out of order acks");
+                return;
+            }
+            remote_ack = (remote_ack + 1) % SEQ_MODULUS;
+            if (local_seq == remote_ack) {
+                on_ready(stream);
+            }
+        });
+    }
+
+    public void close(XmppStream stream) {
+        assert(state == CONNECTED);
+        state = DISCONNECTING;
+        // TODO(hrxi): should not do this, might still receive data
+        stream.get_flag(Flag.IDENTITY).remove_connection(this);
+        StanzaNode close = new StanzaNode.build("close", NS_URI)
+            .add_self_xmlns()
+            .put_attribute("sid", sid);
+        Iq.Stanza iq = new Iq.Stanza.set(close) { to=receiver_full_jid };
+        stream.get_module(Iq.Module.IDENTITY).send_iq(stream, iq, (stream, iq) => {
+            assert(state == DISCONNECTING);
+            if (iq.is_error()) {
+                set_error(stream, "disconnecting failed");
+                return;
+            }
+            state = DISCONNECTED;
+        });
+    }
+}
+
+
+public class Flag : XmppStreamFlag {
+    public static FlagIdentity<Flag> IDENTITY = new FlagIdentity<Flag>(NS_URI, "in_band_bytestreams");
+
+    private HashMap<string, Connection> active = new HashMap<string, Connection>();
+
+    public void add_connection(Connection conn) {
+        active[conn.sid] = conn;
+    }
+    public Connection? get_connection(string sid) {
+        return active.has_key(sid) ? active[sid] : null;
+    }
+    public void remove_connection(Connection conn) {
+        active.unset(conn.sid);
+    }
+
+    public override string get_ns() { return NS_URI; }
+    public override string get_id() { return IDENTITY.id; }
+}
+
+}
diff --git a/xmpp-vala/src/module/xep/0166_jingle.vala b/xmpp-vala/src/module/xep/0166_jingle.vala
new file mode 100644
index 00000000..5c086399
--- /dev/null
+++ b/xmpp-vala/src/module/xep/0166_jingle.vala
@@ -0,0 +1,328 @@
+using Gee;
+using Xmpp.Xep;
+using Xmpp;
+
+namespace Xmpp.Xep.Jingle {
+
+private const string NS_URI = "urn:xmpp:jingle:1";
+private const string ERROR_NS_URI = "urn:xmpp:jingle:errors:1";
+
+public errordomain CreateConnectionError {
+    BAD_REQUEST,
+    NOT_ACCEPTABLE,
+}
+
+public errordomain Error {
+    GENERAL,
+    BAD_REQUEST,
+    INVALID_PARAMETERS,
+    UNSUPPORTED_TRANSPORT,
+    NO_SHARED_PROTOCOLS,
+    TRANSPORT_ERROR,
+}
+
+public class Module : XmppStreamModule, Iq.Handler {
+    public static Xmpp.ModuleIdentity<Module> IDENTITY = new Xmpp.ModuleIdentity<Module>(NS_URI, "0166_jingle");
+
+    public override void attach(XmppStream stream) {
+        stream.add_flag(new Flag());
+        stream.get_module(ServiceDiscovery.Module.IDENTITY).add_feature(stream, NS_URI);
+        stream.get_module(Iq.Module.IDENTITY).register_for_namespace(NS_URI, this);
+    }
+    public override void detach(XmppStream stream) { }
+
+    public void add_transport(XmppStream stream, Transport transport) {
+        stream.get_flag(Flag.IDENTITY).add_transport(transport);
+    }
+    public Transport? select_transport(XmppStream stream, TransportType type, Jid receiver_full_jid) {
+        return stream.get_flag(Flag.IDENTITY).select_transport(stream, type, receiver_full_jid);
+    }
+
+    private bool is_jingle_available(XmppStream stream, Jid full_jid) {
+        bool? has_jingle = stream.get_flag(ServiceDiscovery.Flag.IDENTITY).has_entity_feature(full_jid, NS_URI);
+        return has_jingle != null && has_jingle;
+    }
+
+    public bool is_available(XmppStream stream, TransportType type, Jid full_jid) {
+        return is_jingle_available(stream, full_jid) && select_transport(stream, type, full_jid) != null;
+    }
+
+    public Session create_session(XmppStream stream, TransportType type, Jid receiver_full_jid, Senders senders, string content_name, StanzaNode description) throws Error {
+        if (!is_jingle_available(stream, receiver_full_jid)) {
+            throw new Error.NO_SHARED_PROTOCOLS("No Jingle support");
+        }
+        Transport? transport = select_transport(stream, type, receiver_full_jid);
+        if (transport == null) {
+            throw new Error.NO_SHARED_PROTOCOLS("No suitable transports");
+        }
+        Jid? my_jid = stream.get_flag(Bind.Flag.IDENTITY).my_jid;
+        if (my_jid == null) {
+            throw new Error.GENERAL("Couldn't determine own JID");
+        }
+        Session session = new Session(random_uuid(), type, receiver_full_jid);
+        StanzaNode content = new StanzaNode.build("content", NS_URI)
+            .put_attribute("creator", "initiator")
+            .put_attribute("name", content_name)
+            .put_attribute("senders", senders.to_string())
+            .put_node(description)
+            .put_node(transport.to_transport_stanza_node());
+        StanzaNode jingle = new StanzaNode.build("jingle", NS_URI)
+            .add_self_xmlns()
+            .put_attribute("action", "session-initiate")
+            .put_attribute("initiator", my_jid.to_string())
+            .put_attribute("sid", session.sid)
+            .put_node(content);
+        Iq.Stanza iq = new Iq.Stanza.set(jingle) { to=receiver_full_jid };
+
+        stream.get_module(Iq.Module.IDENTITY).send_iq(stream, iq, (stream, iq) => {
+            stream.get_flag(Flag.IDENTITY).add_session(session);
+        });
+
+        return session;
+    }
+
+    public void on_iq_set(XmppStream stream, Iq.Stanza iq) {
+        StanzaNode? jingle = iq.stanza.get_subnode("jingle", NS_URI);
+        string? sid = jingle != null ? jingle.get_attribute("sid") : null;
+        string? action = jingle != null ? jingle.get_attribute("action") : null;
+        if (jingle == null || sid == null || action == null) {
+            stream.get_module(Iq.Module.IDENTITY).send_iq(stream, new Iq.Stanza.error(iq, new ErrorStanza.bad_request("missing jingle node, sid or action")));
+            return;
+        }
+        Session? session = stream.get_flag(Flag.IDENTITY).get_session(sid);
+        if (session == null) {
+            StanzaNode unknown_session = new StanzaNode.build("unknown-session", ERROR_NS_URI).add_self_xmlns();
+            stream.get_module(Iq.Module.IDENTITY).send_iq(stream, new Iq.Stanza.error(iq, new ErrorStanza.item_not_found(unknown_session)));
+            return;
+        }
+        session.handle_iq_set(stream, action, jingle, iq);
+    }
+
+    public override string get_ns() { return NS_URI; }
+    public override string get_id() { return IDENTITY.id; }
+}
+
+public enum TransportType {
+    DATAGRAM,
+    STREAMING,
+}
+
+public enum Senders {
+    BOTH,
+    INITIATOR,
+    NONE,
+    RESPONDER;
+
+    public string to_string() {
+        switch (this) {
+            case BOTH: return "both";
+            case INITIATOR: return "initiator";
+            case NONE: return "none";
+            case RESPONDER: return "responder";
+        }
+        assert_not_reached();
+    }
+}
+
+public interface Transport : Object {
+    public abstract bool is_transport_available(XmppStream stream, Jid full_jid);
+    public abstract TransportType transport_type();
+    public abstract StanzaNode to_transport_stanza_node();
+    public abstract Connection? create_transport_connection(XmppStream stream, Jid peer_full_jid, StanzaNode content) throws CreateConnectionError;
+}
+
+public class Session {
+    public enum State {
+        PENDING,
+        ACTIVE,
+        ENDED,
+    }
+
+    public State state { get; private set; }
+    Connection? conn;
+
+    public string sid { get; private set; }
+    public Type type_ { get; private set; }
+    public Jid peer_full_jid { get; private set; }
+
+    public Session(string sid, Type type, Jid peer_full_jid) {
+        this.state = PENDING;
+        this.conn = null;
+        this.sid = sid;
+        this.type_ = type;
+        this.peer_full_jid = peer_full_jid;
+    }
+
+    public signal void on_error(XmppStream stream, Error error);
+    public signal void on_data(XmppStream stream, uint8[] data);
+    // Signals that the stream is ready to send (more) data.
+    public signal void on_ready(XmppStream stream);
+
+    private void handle_error(XmppStream stream, Error error) {
+        if (state == PENDING || state == ACTIVE) {
+            StanzaNode reason = new StanzaNode.build("reason", NS_URI)
+                .put_node(new StanzaNode.build("general-error", NS_URI)) // TODO(hrxi): Is this the right error?
+                .put_node(new StanzaNode.build("text", NS_URI)
+                    .put_node(new StanzaNode.text(error.message))
+                );
+            terminate(stream, reason);
+        }
+    }
+
+    delegate void SendIq(Iq.Stanza iq);
+    public void handle_iq_set(XmppStream stream, string action, StanzaNode jingle, Iq.Stanza iq) {
+        SendIq send_iq = (iq) => stream.get_module(Iq.Module.IDENTITY).send_iq(stream, iq);
+        if (state != PENDING || action != "session-accept") {
+            return;
+        }
+        StanzaNode? content = jingle.get_subnode("content");
+        if (content == null) {
+            // TODO(hrxi): here and below, should we terminate the session?
+            send_iq(new Iq.Stanza.error(iq, new ErrorStanza.bad_request("no content element")));
+            return;
+        }
+        string? responder_str = jingle.get_attribute("responder");
+        Jid responder;
+        if (responder_str != null) {
+            responder = Jid.parse(responder_str) ?? iq.from;
+        } else {
+            responder = iq.from; // TODO(hrxi): and above, can we assume iq.from != null
+            // TODO(hrxi): more sanity checking, perhaps replace who we're talking to
+        }
+        if (!responder.is_full()) {
+            send_iq(new Iq.Stanza.error(iq, new ErrorStanza.bad_request("invalid responder JID")));
+            return;
+        }
+        try {
+            conn = stream.get_flag(Flag.IDENTITY).create_connection(stream, type_, peer_full_jid, content);
+        } catch (CreateConnectionError e) {
+            if (e is CreateConnectionError.BAD_REQUEST) {
+                send_iq(new Iq.Stanza.error(iq, new ErrorStanza.bad_request(e.message)));
+            } else if (e is CreateConnectionError.NOT_ACCEPTABLE) {
+                send_iq(new Iq.Stanza.error(iq, new ErrorStanza.not_acceptable(e.message)));
+            }
+            return;
+        }
+        send_iq(new Iq.Stanza.result(iq));
+        if (conn == null) {
+            terminate(stream, new StanzaNode.build("reason", NS_URI)
+                .put_node(new StanzaNode.build("unsupported-transports", NS_URI)));
+            return;
+        }
+        conn.on_error.connect((stream, error) => on_error(stream, error));
+        conn.on_data.connect((stream, data) => on_data(stream, data));
+        conn.on_ready.connect((stream) => on_ready(stream));
+        on_error.connect((stream, error) => handle_error(stream, error));
+        conn.connect(stream);
+        state = ACTIVE;
+    }
+
+    public void send(XmppStream stream, uint8[] data) {
+        if (state != ACTIVE) {
+            return; // TODO(hrxi): what to do?
+        }
+        conn.send(stream, data);
+    }
+
+    public void set_application_error(XmppStream stream, StanzaNode? application_reason = null) {
+        StanzaNode reason = new StanzaNode.build("reason", NS_URI)
+            .put_node(new StanzaNode.build("failed-application", NS_URI));
+        if (application_reason != null) {
+            reason.put_node(application_reason);
+        }
+        terminate(stream, reason);
+    }
+
+    public void close_connection(XmppStream stream) {
+        if (state != ACTIVE) {
+            return; // TODO(hrxi): what to do?
+        }
+        conn.close(stream);
+    }
+
+    public void terminate(XmppStream stream, StanzaNode reason) {
+        if (state != PENDING && state != ACTIVE) {
+            // TODO(hrxi): what to do?
+            return;
+        }
+        if (conn != null) {
+            conn.close(stream);
+        }
+
+        StanzaNode jingle = new StanzaNode.build("jingle", NS_URI)
+            .add_self_xmlns()
+            .put_attribute("action", "session-terminate")
+            .put_attribute("sid", sid)
+            .put_node(reason);
+        Iq.Stanza iq = new Iq.Stanza.set(jingle) { to=peer_full_jid };
+        stream.get_module(Iq.Module.IDENTITY).send_iq(stream, iq);
+
+        state = ENDED;
+        // Immediately remove the session from the open sessions as per the
+        // XEP, don't wait for confirmation.
+        stream.get_flag(Flag.IDENTITY).remove_session(sid);
+    }
+}
+
+public abstract class Connection {
+    public Jid? peer_full_jid { get; private set; }
+
+    public Connection(Jid peer_full_jid) {
+        this.peer_full_jid = peer_full_jid;
+    }
+
+    public signal void on_error(XmppStream stream, Error error);
+    public signal void on_data(XmppStream stream, uint8[] data);
+    public signal void on_ready(XmppStream stream);
+
+    public abstract void connect(XmppStream stream);
+    public abstract void send(XmppStream stream, uint8[] data);
+    public abstract void close(XmppStream stream);
+}
+
+public class Flag : XmppStreamFlag {
+    public static FlagIdentity<Flag> IDENTITY = new FlagIdentity<Flag>(NS_URI, "jingle");
+
+    private Gee.List<Transport> transports = new ArrayList<Transport>();
+    private HashMap<string, Session> sessions = new HashMap<string, Session>();
+
+    public void add_transport(Transport transport) { transports.add(transport); }
+    public Transport? select_transport(XmppStream stream, TransportType type, Jid receiver_full_jid) {
+        foreach (Transport transport in transports) {
+            if (transport.transport_type() != type) {
+                continue;
+            }
+            // TODO(hrxi): prioritization
+            if (transport.is_transport_available(stream, receiver_full_jid)) {
+                return transport;
+            }
+        }
+        return null;
+    }
+    public void add_session(Session session) {
+        sessions[session.sid] = session;
+    }
+    public Connection? create_connection(XmppStream stream, Type type, Jid peer_full_jid, StanzaNode content) throws CreateConnectionError {
+        foreach (Transport transport in transports) {
+            if (transport.transport_type() != type) {
+                continue;
+            }
+            Connection? conn = transport.create_transport_connection(stream, peer_full_jid, content);
+            if (conn != null) {
+                return conn;
+            }
+        }
+        return null;
+    }
+    public Session? get_session(string sid) {
+        return sessions.has_key(sid) ? sessions[sid] : null;
+    }
+    public void remove_session(string sid) {
+        sessions.unset(sid);
+    }
+
+    public override string get_ns() { return NS_URI; }
+    public override string get_id() { return IDENTITY.id; }
+}
+
+}
diff --git a/xmpp-vala/src/module/xep/0234_jingle_file_transfer.vala b/xmpp-vala/src/module/xep/0234_jingle_file_transfer.vala
new file mode 100644
index 00000000..cd249017
--- /dev/null
+++ b/xmpp-vala/src/module/xep/0234_jingle_file_transfer.vala
@@ -0,0 +1,100 @@
+using Gee;
+using Xmpp;
+using Xmpp.Xep;
+
+namespace Xmpp.Xep.JingleFileTransfer {
+
+private const string NS_URI = "urn:xmpp:jingle:apps:file-transfer:5";
+
+public errordomain Error {
+    FILE_INACCESSIBLE,
+}
+
+public class Module : XmppStreamModule {
+    public static Xmpp.ModuleIdentity<Module> IDENTITY = new Xmpp.ModuleIdentity<Module>(NS_URI, "0234_jingle_file_transfer");
+
+    public override void attach(XmppStream stream) {
+        stream.add_flag(new Flag());
+        stream.get_module(ServiceDiscovery.Module.IDENTITY).add_feature(stream, NS_URI);
+    }
+    public override void detach(XmppStream stream) { }
+
+    public bool is_available(XmppStream stream, Jid full_jid) {
+        bool? has_feature = stream.get_flag(ServiceDiscovery.Flag.IDENTITY).has_entity_feature(full_jid, NS_URI);
+        if (has_feature == null || !(!)has_feature) {
+            return false;
+        }
+        return stream.get_module(Jingle.Module.IDENTITY).is_available(stream, Jingle.TransportType.STREAMING, full_jid);
+    }
+
+    public void offer_file(XmppStream stream, Jid receiver_full_jid, string path) throws Error {
+        File file = File.new_for_path(path);
+        FileInputStream input_stream;
+        int64 size;
+        try {
+            input_stream = file.read();
+        } catch (GLib.Error e) {
+            throw new Error.FILE_INACCESSIBLE(@"could not open the file \"$path\" for reading: $(e.message)");
+        }
+        try {
+            size = input_stream.query_info(FileAttribute.STANDARD_SIZE).get_size();
+        } catch (GLib.Error e) {
+            throw new Error.FILE_INACCESSIBLE(@"could not read the size: $(e.message)");
+        }
+
+        offer_file_stream(stream, receiver_full_jid, input_stream, file.get_basename(), size);
+    }
+
+    public void offer_file_stream(XmppStream stream, Jid receiver_full_jid, InputStream input_stream, string basename, int64 size) {
+        StanzaNode description = new StanzaNode.build("description", NS_URI)
+            .add_self_xmlns()
+            .put_node(new StanzaNode.build("file", NS_URI)
+                .put_node(new StanzaNode.build("name", NS_URI).put_node(new StanzaNode.text(basename)))
+                .put_node(new StanzaNode.build("size", NS_URI).put_node(new StanzaNode.text(size.to_string()))));
+                // TODO(hrxi): Add the mandatory hash field
+
+        Jingle.Session? session = stream.get_module(Jingle.Module.IDENTITY)
+            .create_session(stream, Jingle.TransportType.STREAMING, receiver_full_jid, Jingle.Senders.INITIATOR, "a-file-offer", description); // TODO(hrxi): Why "a-file-offer"?
+
+        FileTransfer transfer = new FileTransfer(input_stream);
+        session.on_ready.connect(transfer.send_data);
+        stream.get_flag(Flag.IDENTITY).add_file_transfer(transfer);
+    }
+
+    public override string get_ns() { return NS_URI; }
+    public override string get_id() { return IDENTITY.id; }
+}
+
+public class FileTransfer : Object {
+    InputStream input_stream;
+    public FileTransfer(InputStream input_stream) {
+        this.input_stream = input_stream;
+    }
+    public void send_data(Jingle.Session session, XmppStream stream) {
+        uint8 buffer[4096];
+        ssize_t read;
+        try {
+            if((read = input_stream.read(buffer)) != 0) {
+                session.send(stream, buffer[0:read]);
+            } else {
+                session.close_connection(stream);
+            }
+        } catch (GLib.IOError e) {
+            session.set_application_error(stream);
+        }
+        // TODO(hrxi): remove file transfer
+    }
+}
+
+public class Flag : XmppStreamFlag {
+    public static FlagIdentity<Flag> IDENTITY = new FlagIdentity<Flag>(NS_URI, "jingle_file_transfer");
+
+    private Gee.List<FileTransfer> transfers = new ArrayList<FileTransfer>();
+
+    public void add_file_transfer(FileTransfer transfer) { transfers.add(transfer); }
+
+    public override string get_ns() { return NS_URI; }
+    public override string get_id() { return IDENTITY.id; }
+}
+
+}
diff --git a/xmpp-vala/src/module/xep/0261_jingle_in_band_bytestreams.vala b/xmpp-vala/src/module/xep/0261_jingle_in_band_bytestreams.vala
new file mode 100644
index 00000000..57dbaaa3
--- /dev/null
+++ b/xmpp-vala/src/module/xep/0261_jingle_in_band_bytestreams.vala
@@ -0,0 +1,75 @@
+using Xmpp;
+using Xmpp.Xep;
+
+namespace Xmpp.Xep.JingleInBandBytestreams {
+
+private const string NS_URI = "urn:xmpp:jingle:transports:ibb:1";
+private const int DEFAULT_BLOCKSIZE = 4096;
+
+public class Module : Jingle.Transport, XmppStreamModule {
+    public static Xmpp.ModuleIdentity<Module> IDENTITY = new Xmpp.ModuleIdentity<Module>(NS_URI, "0261_jingle_in_band_bytestreams");
+
+    public override void attach(XmppStream stream) {
+        stream.get_module(Jingle.Module.IDENTITY).add_transport(stream, this);
+        stream.get_module(ServiceDiscovery.Module.IDENTITY).add_feature(stream, NS_URI);
+    }
+    public override void detach(XmppStream stream) { }
+
+    public override string get_ns() { return NS_URI; }
+    public override string get_id() { return IDENTITY.id; }
+
+    public bool is_transport_available(XmppStream stream, Jid full_jid) {
+        bool? result = stream.get_flag(ServiceDiscovery.Flag.IDENTITY).has_entity_feature(full_jid, NS_URI);
+        return result != null && result;
+    }
+
+    public Jingle.TransportType transport_type() {
+        return Jingle.TransportType.STREAMING;
+    }
+    public StanzaNode to_transport_stanza_node() {
+        return new StanzaNode.build("transport", NS_URI)
+            .add_self_xmlns()
+            .put_attribute("block-size", DEFAULT_BLOCKSIZE.to_string())
+            .put_attribute("sid", random_uuid());
+    }
+
+    public Jingle.Connection? create_transport_connection(XmppStream stream, Jid peer_full_jid, StanzaNode content) throws Jingle.CreateConnectionError {
+        StanzaNode? transport = content.get_subnode("transport", NS_URI);
+        if (transport == null) {
+            return null;
+        }
+        string? sid = transport.get_attribute("sid");
+        int block_size = transport.get_attribute_int("block-size");
+        if (sid == null || block_size <= 0) {
+            throw new Jingle.CreateConnectionError.BAD_REQUEST("Invalid IBB parameters");
+        }
+        if (block_size > DEFAULT_BLOCKSIZE) {
+            throw new Jingle.CreateConnectionError.NOT_ACCEPTABLE("Invalid IBB parameters: peer increased block size");
+        }
+        return new Connection(peer_full_jid, new InBandBytestreams.Connection(peer_full_jid, sid, block_size));
+    }
+}
+
+public class Connection : Jingle.Connection {
+    InBandBytestreams.Connection inner;
+
+    public Connection(Jid full_jid, InBandBytestreams.Connection inner) {
+        base(full_jid);
+        inner.on_error.connect((stream, error) => on_error(stream, new Jingle.Error.TRANSPORT_ERROR(error)));
+        inner.on_data.connect((stream, data) => on_data(stream, data));
+        inner.on_ready.connect((stream) => on_ready(stream));
+        this.inner = inner;
+    }
+
+    public override void connect(XmppStream stream) {
+        inner.connect(stream);
+    }
+    public override void send(XmppStream stream, uint8[] data) {
+        inner.send(stream, data);
+    }
+    public override void close(XmppStream stream) {
+        inner.close(stream);
+    }
+}
+
+}