LibCore: Add CTCPServer

This is pretty much a find/replace copy of CLocalServer, and some
modifications to CTCPSocket and CSocketAddress to support it.

Libraries/LibCore/CSocketAddress.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <AK/IPv4Address.h>
+#include <arpa/inet.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 
@@ -19,6 +20,13 @@ public:
     {
     }
 
+    CSocketAddress(const IPv4Address& address, u16 port)
+        : m_type(Type::IPv4)
+        , m_ipv4_address(address)
+        , m_port(port)
+    {
+    }
+
     static CSocketAddress local(const String& address)
     {
         CSocketAddress addr;
@@ -30,12 +38,13 @@ public:
     Type type() const { return m_type; }
     bool is_valid() const { return m_type != Type::Invalid; }
     IPv4Address ipv4_address() const { return m_ipv4_address; }
+    u16 port() const { return m_port; }
 
     String to_string() const
     {
         switch (m_type) {
         case Type::IPv4:
-            return m_ipv4_address.to_string();
+            return String::format("%s:%d", m_ipv4_address.to_string().characters(), m_port);
         case Type::Local:
             return m_local_address;
         default:
@@ -53,9 +62,20 @@ public:
         return address;
     }
 
+    sockaddr_in to_sockaddr_in() const
+    {
+        ASSERT(type() == Type::IPv4);
+        sockaddr_in address;
+        address.sin_family = AF_INET;
+        address.sin_addr.s_addr = m_ipv4_address.to_in_addr_t();
+        address.sin_port = htons(m_port);
+        return address;
+    }
+
 private:
     Type m_type { Type::Invalid };
     IPv4Address m_ipv4_address;
+    u16 m_port;
     String m_local_address;
 };
 

Libraries/LibCore/CTCPServer.cpp

@@ -0,0 +1,55 @@
+#include <AK/IPv4Address.h>
+#include <AK/Types.h>
+#include <LibCore/CTCPServer.h>
+#include <LibCore/CTCPSocket.h>
+#include <LibCore/CNotifier.h>
+#include <stdio.h>
+#include <sys/socket.h>
+
+CTCPServer::CTCPServer(CObject* parent)
+    : CObject(parent)
+{
+    m_fd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK | SOCK_CLOEXEC, 0);
+    ASSERT(m_fd >= 0);
+}
+
+CTCPServer::~CTCPServer()
+{
+}
+
+bool CTCPServer::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 = make<CNotifier>(m_fd, CNotifier::Event::Read);
+    m_notifier->on_ready_to_read = [this] {
+        if (on_ready_to_accept)
+            on_ready_to_accept();
+    };
+    return true;
+}
+
+CTCPSocket* CTCPServer::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 new CTCPSocket({}, accepted_fd);
+}

Libraries/LibCore/CTCPServer.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <AK/IPv4Address.h>
+#include <LibCore/CNotifier.h>
+#include <LibCore/CObject.h>
+
+class CTCPSocket;
+
+class CTCPServer : public CObject {
+    C_OBJECT(CTCPServer)
+public:
+    explicit CTCPServer(CObject* parent = nullptr);
+    virtual ~CTCPServer() override;
+
+    bool is_listening() const { return m_listening; }
+    bool listen(const IPv4Address& address, u16 port);
+
+    CTCPSocket* accept();
+
+    Function<void()> on_ready_to_accept;
+
+private:
+    int m_fd { -1 };
+    bool m_listening { false };
+    OwnPtr<CNotifier> m_notifier;
+};

Libraries/LibCore/CTCPSocket.cpp

@@ -1,5 +1,14 @@
 #include <LibCore/CTCPSocket.h>
 #include <sys/socket.h>
+#include <errno.h>
+
+CTCPSocket::CTCPSocket(Badge<CTCPServer>, int fd, CObject* parent)
+    : CSocket(CSocket::Type::TCP, parent)
+{
+    set_fd(fd);
+    set_mode(CIODevice::ReadWrite);
+    set_error(0);
+}
 
 CTCPSocket::CTCPSocket(CObject* parent)
     : CSocket(CSocket::Type::TCP, parent)

Libraries/LibCore/CTCPSocket.h

@@ -1,8 +1,14 @@
+#pragma once
+
+#include <AK/Badge.h>
 #include <LibCore/CSocket.h>
 
+class CTCPServer;
+
 class CTCPSocket final : public CSocket {
     C_OBJECT(CTCPSocket)
 public:
     explicit CTCPSocket(CObject* parent = nullptr);
+    CTCPSocket(Badge<CTCPServer>, int fd, CObject* parent = nullptr);
     virtual ~CTCPSocket() override;
 };

Libraries/LibCore/Makefile

@@ -9,6 +9,7 @@ OBJS = \
     CLocalSocket.o \
     CLocalServer.o \
     CTCPSocket.o \
+    CTCPServer.o \
     CElapsedTimer.o \
     CNotifier.o \
     CHttpRequest.o \