Kernel: Fixup rtl8139, add basic ARP and ethernet support

Currently the ARP appears to be able to respond to requests.

2 files changed, 88 insertions, 24 deletions

diff --git a/drivers/rtl8139.c b/drivers/rtl8139.c
index 0d665b1..0c1606b 100644
--- a/drivers/rtl8139.c
+++ b/drivers/rtl8139.c
@@ -4,6 +4,7 @@
 #include <drivers/pci.h>
 #include <drivers/rtl8139.h>
 #include <mmu.h>
+#include <network/ethernet.h>
 
 #define RBSTART 0x30
 #define CMD 0x37
@@ -13,31 +14,84 @@
 #define TSAD0 0x20 // transmit start address
 
 struct PCI_DEVICE rtl8139;
-uint8_t device_buffer[8192 + 16];
-uint32_t g_base_address;
+uint8_t *device_buffer;
 
 uint8_t *send_buffers[4];
 
-#define ROK (1 << 0)
-#define TOK (1 << 2)
+struct _INT_PACKET_HEADER {
+  uint8_t ROK : 1;
+  uint8_t FAE : 1;
+  uint8_t CRC : 1;
+  uint8_t LONG : 1;
+  uint8_t RUNT : 1;
+  uint8_t ISE : 1;
+  uint8_t reserved : 5;
+  uint8_t BAR : 1;
+  uint8_t PAM : 1;
+  uint8_t MAR : 1;
+};
+
+struct PACKET_HEADER {
+  union {
+    uint16_t raw;
+    struct _INT_PACKET_HEADER data;
+  };
+};
+
+uint16_t current_packet_read = 0;
+
+void handle_packet(void) {
+  assert(sizeof(struct _INT_PACKET_HEADER) == sizeof(uint16_t));
+
+  uint16_t *buf = (uint16_t *)(device_buffer + current_packet_read);
+  struct PACKET_HEADER packet_header;
+  packet_header.raw = *buf;
+  assert(packet_header.data.ROK);
+  kprintf("packet_header.raw: %x\n", packet_header.raw);
+  uint16_t packet_length = *(buf + 1);
+  kprintf("packet_length: %x\n", packet_length);
+
+  uint8_t packet_buffer[8192 + 16];
+  if (current_packet_read + packet_length >= 8192 + 16) {
+    uint32_t first_run = ((uint8_t *)buf + (8192 + 16)) - device_buffer;
+    memcpy(packet_buffer, buf, first_run);
+    memcpy(packet_buffer, device_buffer, packet_length - first_run);
+  } else {
+    memcpy(packet_buffer, buf, packet_length);
+  }
+
+  handle_ethernet((uint8_t *)packet_buffer + 4, packet_length);
+
+  // Thanks to exscape
+  // https://github.com/exscape/exscapeOS/blob/master/src/kernel/net/rtl8139.c
+  // and the programmers guide
+  // https://www.cs.usfca.edu/~cruse/cs326f04/RTL8139_ProgrammersGuide.pdf I
+  // have no clue what this calculation, I can't find anything possibly relating
+  // to this in the manual, but it does work I guess.
+  current_packet_read = (current_packet_read + packet_length + 4 + 3) & (~3);
+  current_packet_read %= 8192 + 16;
+  outw(rtl8139.gen.base_mem_io + 0x38, current_packet_read - 0x10);
+}
 
 __attribute__((interrupt)) void rtl8139_handler(void *regs) {
   (void)regs;
   uint16_t status = inw(rtl8139.gen.base_mem_io + 0x3e);
+  kprintf("status: %x\n", status);
 
-  if (status & TOK) {
+  outw(rtl8139.gen.base_mem_io + 0x3E, 0x5);
+  if (status & (1 << 2)) {
     kprintf("Packet sent\n");
   }
-  if (status & ROK) {
+  if (status & (1 << 0)) {
     kprintf("Received packet\n");
+    handle_packet();
   }
 
-  outw(rtl8139.gen.base_mem_io + 0x3E, 0x5);
   EOI(0xB);
 }
 
-int rtl8139_send_data(const struct PCI_DEVICE *device, uint8_t *data,
-                      uint16_t data_size) {
+int rtl8139_send_data(uint8_t *data, uint16_t data_size) {
+  const struct PCI_DEVICE *device = &rtl8139;
   // FIXME: It should block or fail if there is too little space for the
   // buffer
   if (data_size > 0x1000)
@@ -54,6 +108,19 @@ int rtl8139_send_data(const struct PCI_DEVICE *device, uint8_t *data,
   return 1;
 }
 
+void get_mac_address(uint8_t mac[6]) {
+  uint32_t base_address = rtl8139.gen.base_mem_io;
+  // Read the MAC address
+  uint64_t mac_address;
+  {
+    uint32_t low_mac = inl(base_address);
+    uint16_t high_mac = inw(base_address + 0x4);
+    mac_address = ((uint64_t)high_mac << 32) | low_mac;
+  }
+  kprintf("mac_address: %x\n", mac_address);
+  memcpy(mac, &mac_address, sizeof(uint8_t[6]));
+}
+
 uint8_t rtl8139_get_transmit_status(uint32_t base_address) {
   uint32_t status_register = inl(base_address + 0x3E);
   if ((status_register >> 3) & 0x1)
@@ -76,14 +143,10 @@ void rtl8139_init(void) {
   uint32_t base_address = rtl8139.gen.base_mem_io;
   uint8_t interrupt_line = pci_get_interrupt_line(&rtl8139);
 
-  // Read the MAC address
-  uint64_t mac_address;
-  {
-    uint32_t low_mac = inl(base_address);
-    uint16_t high_mac = inw(base_address + 0x4);
-    mac_address = ((uint64_t)high_mac << 32) | low_mac;
-  }
-  kprintf("mac_address: %x\n", mac_address);
+  // Enable bus mastering
+  uint32_t register1 = pci_config_read32(&rtl8139, 0, 0x4);
+  register1 |= (1 << 2);
+  pci_config_write32(&rtl8139, 0, 0x4, register1);
 
   // Turning on the device
   outb(base_address + 0x52, 0x0);
@@ -92,19 +155,21 @@ void rtl8139_init(void) {
   outb(base_address + CMD, 0x10);
   for (; 0 != (inb(base_address + CMD) & 0x10);)
     ;
-
+  device_buffer = ksbrk(8192 + 16);
+  memset(device_buffer, 0, 8192 + 16);
   // Setupt the recieve buffer
   uint32_t rx_buffer = (uint32_t)virtual_to_physical(device_buffer, NULL);
   outl(base_address + RBSTART, rx_buffer);
 
   // Set IMR + ISR
-  outw(base_address + IMR, (1 << 2) | (1 << 3));
+  outw(base_address + IMR, (1 << 2) | (1 << 3) | (1 << 0));
 
+  // Set transmit and reciever enable
   outb(base_address + 0x37, (1 << 2) | (1 << 3));
 
   // Configure the recieve buffer
   outl(base_address + 0x44,
-       0xf | (1 << 7)); // (1 << 7) is the WRAP bit, 0xf is AB+AM+APM+AAP
+       0xf); // 0xf is AB+AM+APM+AAP
 
   install_handler(rtl8139_handler, INT_32_INTERRUPT_GATE(0x0),
                   0x20 + interrupt_line);
@@ -114,10 +179,6 @@ void rtl8139_init(void) {
   for (int i = 0; i < 4; i++)
     send_buffers[i] = ksbrk(0x1000);
   asm("sti");
-  for (int i = 0; i < 10; i++) {
-    char buffer[512];
-    rtl8139_send_data(&rtl8139, (uint8_t *)buffer, 512);
-  }
   for (;;)
     asm("sti");
 }
diff --git a/drivers/rtl8139.h b/drivers/rtl8139.h
index 1f3d84e..6e13fdd 100644
--- a/drivers/rtl8139.h
+++ b/drivers/rtl8139.h
@@ -1 +1,4 @@
+#include <stdint.h>
+void get_mac_address(uint8_t mac[6]);
 void rtl8139_init(void);
+int rtl8139_send_data(uint8_t *data, uint16_t data_size);