ImageDecoder: Add a new service for out-of-process image decoding :^)

The new ImageDecoder service (available for members of "image" via
/tmp/portal/image) allows you to decode images in a separate process.

This will allow programs to confidently load untrusted images, since
the bulk of the security concerns are sandboxed to a separate process.

The only API right now is a synchronous IPC DecodeImage() call that
takes a shbuf with encoded image data and returns a shared buffer and
metadata for the decoded image.

It also comes with a very simple library for interfacing with the
ImageDecoder service: LibImageDecoderClient. The name is a bit of a
mouthful but I guess we can rename it later if we think of something
nicer to call it.

There's obviously a bit of overhead to spawning a separate process
for every image decode, so this is mostly only appropriate for
untrusted images (e.g stuff downloaded from the web) and not necessary
for trusted local images (e.g stuff in /res)

7 files changed, 265 insertions, 0 deletions

diff --git a/Services/ImageDecoder/CMakeLists.txt b/Services/ImageDecoder/CMakeLists.txt
new file mode 100644
index 0000000000..ce9ad077fc
--- /dev/null
+++ b/Services/ImageDecoder/CMakeLists.txt
@@ -0,0 +1,12 @@
+compile_ipc(ImageDecoderServer.ipc ImageDecoderServerEndpoint.h)
+compile_ipc(ImageDecoderClient.ipc ImageDecoderClientEndpoint.h)
+
+set(SOURCES
+    ClientConnection.cpp
+    main.cpp
+    ImageDecoderServerEndpoint.h
+    ImageDecoderClientEndpoint.h
+)
+
+serenity_bin(ImageDecoder)
+target_link_libraries(ImageDecoder LibIPC LibGfx)
diff --git a/Services/ImageDecoder/ClientConnection.cpp b/Services/ImageDecoder/ClientConnection.cpp
new file mode 100644
index 0000000000..ce7ec85d6b
--- /dev/null
+++ b/Services/ImageDecoder/ClientConnection.cpp
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <AK/Badge.h>
+#include <AK/SharedBuffer.h>
+#include <ImageDecoder/ClientConnection.h>
+#include <ImageDecoder/ImageDecoderClientEndpoint.h>
+#include <LibGfx/Bitmap.h>
+#include <LibGfx/ImageDecoder.h>
+#include <LibGfx/SystemTheme.h>
+
+namespace ImageDecoder {
+
+static HashMap<int, RefPtr<ClientConnection>> s_connections;
+
+ClientConnection::ClientConnection(Core::LocalSocket& socket, int client_id)
+    : IPC::ClientConnection<ImageDecoderServerEndpoint>(*this, socket, client_id)
+{
+    s_connections.set(client_id, *this);
+}
+
+ClientConnection::~ClientConnection()
+{
+}
+
+void ClientConnection::die()
+{
+    s_connections.remove(client_id());
+    exit(0);
+}
+
+OwnPtr<Messages::ImageDecoderServer::GreetResponse> ClientConnection::handle(const Messages::ImageDecoderServer::Greet& message)
+{
+    set_client_pid(message.client_pid());
+    return make<Messages::ImageDecoderServer::GreetResponse>(client_id(), getpid());
+}
+
+OwnPtr<Messages::ImageDecoderServer::DecodeImageResponse> ClientConnection::handle(const Messages::ImageDecoderServer::DecodeImage& message)
+{
+    auto encoded_buffer = SharedBuffer::create_from_shbuf_id(message.encoded_shbuf_id());
+    if (!encoded_buffer) {
+#ifdef IMAGE_DECODER_DEBUG
+        dbg() << "Could not map encoded data buffer";
+#endif
+        return nullptr;
+    }
+
+    if (message.encoded_size() > (size_t)encoded_buffer->size()) {
+#ifdef IMAGE_DECODER_DEBUG
+        dbg() << "Encoded buffer is smaller than encoded size";
+#endif
+        return nullptr;
+    }
+
+#ifdef IMAGE_DECODER_DEBUG
+    dbg() << "Trying to decode " << message.encoded_size() << " bytes of image(?) data in shbuf_id=" << message.encoded_shbuf_id() << " (shbuf size: " << encoded_buffer->size() << ")";
+#endif
+
+    auto decoder = Gfx::ImageDecoder::create((const u8*)encoded_buffer->data(), message.encoded_size());
+    auto bitmap = decoder->bitmap();
+
+    if (!bitmap) {
+#ifdef IMAGE_DECODER_DEBUG
+        dbg() << "Could not decode image from encoded data";
+#endif
+        return make<Messages::ImageDecoderServer::DecodeImageResponse>(-1, Gfx::IntSize(), (i32)Gfx::BitmapFormat::Invalid, Vector<u32>());
+    }
+
+    // FIXME: We should fix ShareableBitmap so you can send it in responses as well as requests..
+    m_shareable_bitmap = bitmap->to_bitmap_backed_by_shared_buffer();
+    m_shareable_bitmap->shared_buffer()->share_with(client_pid());
+    Vector<u32> palette;
+    if (m_shareable_bitmap->is_indexed()) {
+        palette = m_shareable_bitmap->palette_to_vector();
+    }
+    return make<Messages::ImageDecoderServer::DecodeImageResponse>(m_shareable_bitmap->shbuf_id(), m_shareable_bitmap->size(), (i32)m_shareable_bitmap->format(), palette);
+}
+
+}
diff --git a/Services/ImageDecoder/ClientConnection.h b/Services/ImageDecoder/ClientConnection.h
new file mode 100644
index 0000000000..3b47ed1894
--- /dev/null
+++ b/Services/ImageDecoder/ClientConnection.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/HashMap.h>
+#include <ImageDecoder/Forward.h>
+#include <ImageDecoder/ImageDecoderServerEndpoint.h>
+#include <LibIPC/ClientConnection.h>
+#include <LibWeb/Forward.h>
+
+namespace ImageDecoder {
+
+class ClientConnection final
+    : public IPC::ClientConnection<ImageDecoderServerEndpoint>
+    , public ImageDecoderServerEndpoint {
+    C_OBJECT(ClientConnection);
+
+public:
+    explicit ClientConnection(Core::LocalSocket&, int client_id);
+    ~ClientConnection() override;
+
+    virtual void die() override;
+
+private:
+    virtual OwnPtr<Messages::ImageDecoderServer::GreetResponse> handle(const Messages::ImageDecoderServer::Greet&) override;
+    virtual OwnPtr<Messages::ImageDecoderServer::DecodeImageResponse> handle(const Messages::ImageDecoderServer::DecodeImage&) override;
+
+    RefPtr<Gfx::Bitmap> m_shareable_bitmap;
+};
+
+}
diff --git a/Services/ImageDecoder/Forward.h b/Services/ImageDecoder/Forward.h
new file mode 100644
index 0000000000..e43ca83960
--- /dev/null
+++ b/Services/ImageDecoder/Forward.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+namespace WebContent {
+
+class ClientConnection;
+class PageHost;
+
+}
diff --git a/Services/ImageDecoder/ImageDecoderClient.ipc b/Services/ImageDecoder/ImageDecoderClient.ipc
new file mode 100644
index 0000000000..49dc3862c2
--- /dev/null
+++ b/Services/ImageDecoder/ImageDecoderClient.ipc
@@ -0,0 +1,4 @@
+endpoint ImageDecoderClient = 7002
+{
+    Dummy() =|
+}
diff --git a/Services/ImageDecoder/ImageDecoderServer.ipc b/Services/ImageDecoder/ImageDecoderServer.ipc
new file mode 100644
index 0000000000..295454282f
--- /dev/null
+++ b/Services/ImageDecoder/ImageDecoderServer.ipc
@@ -0,0 +1,7 @@
+endpoint ImageDecoderServer = 7001
+{
+    Greet(i32 client_pid) => (i32 client_id, i32 server_pid)
+
+    DecodeImage(i32 encoded_shbuf_id, u32 encoded_size) => (i32 decoded_shbuf_id, Gfx::IntSize size, i32 bitmap_format, Vector<u32> palette)
+
+}
diff --git a/Services/ImageDecoder/main.cpp b/Services/ImageDecoder/main.cpp
new file mode 100644
index 0000000000..1ee15b1496
--- /dev/null
+++ b/Services/ImageDecoder/main.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <LibCore/EventLoop.h>
+#include <LibCore/LocalServer.h>
+#include <LibIPC/ClientConnection.h>
+#include <ImageDecoder/ClientConnection.h>
+
+int main(int, char**)
+{
+    Core::EventLoop event_loop;
+    if (pledge("stdio shared_buffer unix", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+    if (unveil(nullptr, nullptr) < 0) {
+        perror("unveil");
+        return 1;
+    }
+
+    auto socket = Core::LocalSocket::take_over_accepted_socket_from_system_server();
+    IPC::new_client_connection<ImageDecoder::ClientConnection>(*socket, 1);
+    if (pledge("stdio shared_buffer", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+    return event_loop.exec();
+}