LibCore: Add UDP socket and server classes

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/3c129172d44

Libraries/LibCore/CUdpServer.cpp

@@ -0,0 +1,107 @@
+/*
+ * 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/IPv4Address.h>
+#include <AK/Types.h>
+#include <LibCore/CNotifier.h>
+#include <LibCore/CUdpServer.h>
+#include <LibCore/CUdpSocket.h>
+#include <stdio.h>
+#include <sys/socket.h>
+
+CUdpServer::CUdpServer(CObject* parent)
+    : CObject(parent)
+{
+    m_fd = socket(AF_INET, SOCK_DGRAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
+    ASSERT(m_fd >= 0);
+}
+
+CUdpServer::~CUdpServer()
+{
+}
+
+bool CUdpServer::listen(const IPv4Address& address, u16 port)
+{
+    if (m_listening)
+        return false;
+
+    int rc;
+    auto socket_address = CSocketAddress(address, port);
+    auto in = socket_address.to_sockaddr_in();
+    rc = ::bind(m_fd, (const sockaddr*)&in, sizeof(in));
+    ASSERT(rc == 0);
+
+    rc = ::listen(m_fd, 5);
+    ASSERT(rc == 0);
+    m_listening = true;
+
+    m_notifier = CNotifier::construct(m_fd, CNotifier::Event::Read);
+    m_notifier->on_ready_to_read = [this] {
+        if (on_ready_to_accept)
+            on_ready_to_accept();
+    };
+    return true;
+}
+
+RefPtr<CUdpSocket> CUdpServer::accept()
+{
+    ASSERT(m_listening);
+    sockaddr_in in;
+    socklen_t in_size = sizeof(in);
+    int accepted_fd = ::accept(m_fd, (sockaddr*)&in, &in_size);
+    if (accepted_fd < 0) {
+        perror("accept");
+        return nullptr;
+    }
+
+    return CUdpSocket::construct(accepted_fd);
+}
+
+Optional<IPv4Address> CUdpServer::local_address() const
+{
+    if (m_fd == -1)
+        return {};
+
+    sockaddr_in address;
+    socklen_t len = sizeof(address);
+    if (getsockname(m_fd, (sockaddr*)&address, &len) != 0)
+        return {};
+
+    return IPv4Address(address.sin_addr.s_addr);
+}
+
+Optional<u16> CUdpServer::local_port() const
+{
+    if (m_fd == -1)
+        return {};
+
+    sockaddr_in address;
+    socklen_t len = sizeof(address);
+    if (getsockname(m_fd, (sockaddr*)&address, &len) != 0)
+        return {};
+
+    return ntohs(address.sin_port);
+}

Libraries/LibCore/CUdpServer.h

@@ -0,0 +1,56 @@
+/*
+ * 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/IPv4Address.h>
+#include <LibCore/CNotifier.h>
+#include <LibCore/CObject.h>
+
+class CUdpSocket;
+
+class CUdpServer : public CObject {
+    C_OBJECT(CUdpServer)
+public:
+    virtual ~CUdpServer() override;
+
+    bool is_listening() const { return m_listening; }
+    bool listen(const IPv4Address& address, u16 port);
+
+    RefPtr<CUdpSocket> accept();
+
+    Optional<IPv4Address> local_address() const;
+    Optional<u16> local_port() const;
+
+    Function<void()> on_ready_to_accept;
+
+private:
+    explicit CUdpServer(CObject* parent = nullptr);
+
+    int m_fd { -1 };
+    bool m_listening { false };
+    RefPtr<CNotifier> m_notifier;
+};

Libraries/LibCore/CUdpSocket.cpp

@@ -0,0 +1,56 @@
+/*
+ * 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/CUdpSocket.h>
+#include <sys/socket.h>
+#include <errno.h>
+
+CUdpSocket::CUdpSocket(int fd, CObject* parent)
+    : CSocket(CSocket::Type::UDP, parent)
+{
+    // NOTE: This constructor is used by CUdpServer::accept(), so the socket is already connected.
+    m_connected = true;
+    set_fd(fd);
+    set_mode(CIODevice::ReadWrite);
+    set_error(0);
+}
+
+CUdpSocket::CUdpSocket(CObject* parent)
+    : CSocket(CSocket::Type::UDP, parent)
+{
+    int fd = socket(AF_INET, SOCK_DGRAM | SOCK_NONBLOCK, 0);
+    if (fd < 0) {
+        set_error(errno);
+    } else {
+        set_fd(fd);
+        set_mode(CIODevice::ReadWrite);
+        set_error(0);
+    }
+}
+
+CUdpSocket::~CUdpSocket()
+{
+}

Libraries/LibCore/CUdpSocket.h

@@ -0,0 +1,40 @@
+/*
+ * 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/Badge.h>
+#include <LibCore/CSocket.h>
+
+class CUdpSocket final : public CSocket {
+    C_OBJECT(CUdpSocket)
+public:
+    virtual ~CUdpSocket() override;
+
+private:
+    CUdpSocket(int fd, CObject* parent = nullptr);
+    explicit CUdpSocket(CObject* parent = nullptr);
+};

Libraries/LibCore/Makefile

@@ -7,6 +7,8 @@ OBJS = \
     CLocalServer.o \
     CTCPSocket.o \
     CTCPServer.o \
+    CUdpSocket.o \
+    CUdpServer.o \
     CElapsedTimer.o \
     CNotifier.o \
     CHttpRequest.o \