Kernel: More work on Ethernet support.

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/1678ac69ef4

Kernel/E1000NetworkAdapter.cpp

@@ -157,9 +157,9 @@ void E1000NetworkAdapter::handle_irq()
         kprintf("E1000: threshold\n");
     }
     if (status & 0x80) {
-        //receive();
+        kprintf("E1000: receive...\n");
+        receive();
     }
-    ASSERT_NOT_REACHED();
 }
 
 void E1000NetworkAdapter::detect_eeprom()
@@ -282,7 +282,6 @@ void E1000NetworkAdapter::out32(word address, dword data)
 {
     if (m_use_mmio) {
         auto* ptr = (volatile dword*)(m_mmio_base.get() + address);
-        kprintf("ptr <-- %p\n", ptr);
         *ptr = data;
         return;
     }
@@ -310,7 +309,7 @@ dword E1000NetworkAdapter::in32(word address)
     return IO::in32(m_io_base + address);
 }
 
-void E1000NetworkAdapter::send(const byte* data, int length)
+void E1000NetworkAdapter::send_raw(const byte* data, int length)
 {
     kprintf("E1000: Sending packet (%d bytes)\n", length);
     auto& descriptor = m_tx_descriptors[m_tx_current];
@@ -323,3 +322,18 @@ void E1000NetworkAdapter::send(const byte* data, int length)
         ;
     kprintf("E1000: Sent packet!\n");
 }
+
+void E1000NetworkAdapter::receive()
+{
+    while (m_rx_descriptors[m_rx_current].status & 1) {
+        auto* buffer = (byte*)m_rx_descriptors[m_rx_current].addr;
+        word length = m_rx_descriptors[m_rx_current].length;
+
+        kprintf("E1000: Received 1 packet @ %p (%u) bytes!\n", buffer, length);
+
+        m_rx_descriptors[m_rx_current].status = 0;
+        auto old_current = m_rx_current;
+        m_rx_current = (m_rx_current + 1) % number_of_rx_descriptors;
+        out32(REG_RXDESCTAIL, old_current);
+    }
+}

Kernel/E1000NetworkAdapter.h

@@ -15,7 +15,7 @@ public:
     E1000NetworkAdapter(PCI::Address, byte irq);
     virtual ~E1000NetworkAdapter() override;
 
-    virtual void send(const byte*, int) override;
+    virtual void send_raw(const byte*, int) override;
 
 private:
     virtual void handle_irq() override;
@@ -57,6 +57,8 @@ private:
     word in16(word address);
     dword in32(word address);
 
+    void receive();
+
     PCI::Address m_pci_address;
     word m_io_base { 0 };
     PhysicalAddress m_mmio_base;

Kernel/EthernetFrameHeader.h

@@ -16,13 +16,14 @@ public:
     word ether_type() const { return (m_ether_type & 0xff) << 16 | ((m_ether_type >> 16) & 0xff); }
     void set_ether_type(word ether_type) { m_ether_type = (ether_type & 0xff) << 16 | ((ether_type >> 16) & 0xff); }
 
-    const void* raw() const { return this; }
-    void* raw() { return this; }
+    const void* payload() const { return &m_payload[0]; }
+    void* payload() { return &m_payload[0]; }
 
 private:
     MACAddress m_destination;
     MACAddress m_source;
     word m_ether_type { 0 };
+    dword m_payload[0];
 };
 
 static_assert(sizeof(EthernetFrameHeader) == 14);

Kernel/MemoryManager.cpp

@@ -99,6 +99,7 @@ void MemoryManager::initialize_paging()
     dbgprintf("MM: Quickmap will use P%x\n", m_quickmap_addr.get());
     dbgprintf("MM: Installing page directory\n");
 #endif
+
     asm volatile("movl %%eax, %%cr3"::"a"(kernel_page_directory().cr3()));
     asm volatile(
         "movl %%cr0, %%eax\n"
@@ -442,6 +443,12 @@ void MemoryManager::enter_process_paging_scope(Process& process)
     asm volatile("movl %%eax, %%cr3"::"a"(process.page_directory().cr3()):"memory");
 }
 
+void MemoryManager::enter_kernel_paging_scope()
+{
+    InterruptDisabler disabler;
+    asm volatile("movl %%eax, %%cr3"::"a"(kernel_page_directory().cr3()):"memory");
+}
+
 void MemoryManager::flush_entire_tlb()
 {
     asm volatile(

Kernel/MemoryManager.h

@@ -242,6 +242,7 @@ public:
     void populate_page_directory(PageDirectory&);
 
     void enter_process_paging_scope(Process&);
+    void enter_kernel_paging_scope();
 
     bool validate_user_read(const Process&, LinearAddress) const;
     bool validate_user_write(const Process&, LinearAddress) const;
@@ -413,3 +414,8 @@ struct ProcessPagingScope {
     ProcessPagingScope(Process& process) { MM.enter_process_paging_scope(process); }
     ~ProcessPagingScope() { MM.enter_process_paging_scope(*current); }
 };
+
+struct KernelPagingScope {
+    KernelPagingScope() { MM.enter_kernel_paging_scope(); }
+    ~KernelPagingScope() { MM.enter_process_paging_scope(*current); }
+};

Kernel/NetworkAdapter.cpp

@@ -1,12 +1,23 @@
 #include <Kernel/NetworkAdapter.h>
 #include <Kernel/StdLib.h>
+#include <Kernel/EthernetFrameHeader.h>
+#include <Kernel/kmalloc.h>
 
 NetworkAdapter::NetworkAdapter()
 {
-    memset(&m_mac_address, 0, sizeof(m_mac_address));
 }
 
 NetworkAdapter::~NetworkAdapter()
 {
 }
 
+void NetworkAdapter::send(const MACAddress& destination, const ARPPacket& packet)
+{
+    int size_in_bytes = sizeof(EthernetFrameHeader) + sizeof(ARPPacket) + 4;
+    auto* eth = (EthernetFrameHeader*)kmalloc(size_in_bytes);
+    eth->set_source(mac_address());
+    eth->set_destination(destination);
+    memcpy(eth->payload(), &packet, sizeof(ARPPacket));
+    send_raw((byte*)eth, size_in_bytes);
+    kfree(eth);
+}

Kernel/NetworkAdapter.h

@@ -2,6 +2,7 @@
 
 #include <AK/Types.h>
 #include <Kernel/MACAddress.h>
+#include <Kernel/ARPPacket.h>
 
 class NetworkAdapter {
 public:
@@ -10,11 +11,12 @@ public:
     virtual const char* class_name() const = 0;
     MACAddress mac_address() { return m_mac_address; }
 
-    virtual void send(const byte*, int) = 0;
+    void send(const MACAddress&, const ARPPacket&);
 
 protected:
     NetworkAdapter();
     void set_mac_address(const MACAddress& mac_address) { m_mac_address = mac_address; }
+    virtual void send_raw(const byte*, int) = 0;
 
 private:
     MACAddress m_mac_address;

Kernel/Process.cpp

@@ -1922,6 +1922,16 @@ int Process::sys$setpgid(pid_t specified_pid, pid_t specified_pgid)
 
 int Process::sys$ioctl(int fd, unsigned request, unsigned arg)
 {
+    if (auto* e1000 = E1000NetworkAdapter::the()) {
+        ARPPacket arp;
+        arp.hardware_type = 1; // Ethernet
+        arp.hardware_address_length = 6; // MAC length
+        arp.protocol_type = 0x0800; // IPv4
+        arp.protocol_address_length = 4; // IP length
+        arp.operation = 1; // 1 (request)
+        e1000->send(MACAddress(), arp);
+    }
+
     auto* descriptor = file_descriptor(fd);
     if (!descriptor)
         return -EBADF;