fixed some things, still nothing

Author: no382001

kernel/kernel.c

@@ -36,21 +36,14 @@ void kernel_main(void) {
   arp_init();
   serial_debug("arp done...");
 
-  uint8_t mac_addr[] = {0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF};
+  uint8_t mac_addr[] = {0};
   get_mac_addr(mac_addr);
 
   /*
   ethernet_send_packet(mac_addr, (void *)str, strlen(str), 0x0021);
   ip_send_packet(ip_addr, (void *)str, strlen(str));
   */
 
-  extern uint8_t my_ip[4];
-  arp_lookup_add(mac_addr, my_ip);
-
-  uint8_t dst_ip[] = {127, 0, 0, 1};
-  icmp_send_echo_request(dst_ip, 1234, 1, 0,
-                         0); // checksum should be the other way
-
   // this does not work i cant seem to set up the network on wsl2 qemu
   // the packet looks okay, but i cant reach the dhcp server
   /*

net/arp.c

@@ -5,9 +5,9 @@
 #include "network.h"
 #include "rtl8139.h"
 
-arp_table_entry_t arp_table[512];
-int arp_table_size;
-int arp_table_curr;
+#define ARP_TABLE_MAX 16
+arp_table_entry_t arp_table[ARP_TABLE_MAX] = {0};
+int arp_table_curr = 0;
 
 uint8_t broadcast_mac_address[] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
 
@@ -20,12 +20,10 @@ void arp_handle_packet(arp_packet_t *arp_packet) {
   // save some packet field
   memcpy(dst_hardware_addr, arp_packet->src_hardware_addr, 6);
   memcpy(dst_protocol_addr, arp_packet->src_protocol_addr, 4);
-  // reply arp request, if the ip address matches(have to hard code the IP
-  // eveywhere, because I don't have dhcp yet)
+
   if (ntohs(arp_packet->opcode) == ARP_REQUEST) {
     if (!memcmp(arp_packet->dst_protocol_addr, my_ip, 4)) {
-      // set source MAC address, IP address (hardcode the IP address as 10.2.2.3
-      // until we really get one..)
+
       get_mac_addr(arp_packet->src_hardware_addr);
       memcpy(arp_packet->src_protocol_addr, my_ip, 4);
 
@@ -50,24 +48,22 @@ void arp_handle_packet(arp_packet_t *arp_packet) {
       ethernet_send_packet(dst_hardware_addr, (uint8_t *)arp_packet,
                            sizeof(arp_packet_t), ETHERNET_TYPE_ARP);
       serial_debug(
-          "sent an arp reply to %d.%d.%d.%d", arp_packet->dst_protocol_addr[0],
-          arp_packet->dst_protocol_addr[1], arp_packet->dst_protocol_addr[2],
-          arp_packet->dst_protocol_addr[3]);
+          "sent an arp reply to %d.%d.%d.%d %x:%x:%x:%x",
+          arp_packet->dst_protocol_addr[0], arp_packet->dst_protocol_addr[1],
+          arp_packet->dst_protocol_addr[2], arp_packet->dst_protocol_addr[3],
+          arp_packet->dst_hardware_addr[0], arp_packet->dst_hardware_addr[1],
+          arp_packet->dst_hardware_addr[2], arp_packet->dst_hardware_addr[3]);
     }
   } else if (ntohs(arp_packet->opcode) == ARP_REPLY) {
-    return; // reply
+    // reply
   } else {
     return; // not for us
   }
-
-  // now, store the ip-mac address mapping relation
-  memcpy(&arp_table[arp_table_curr].ip_addr, dst_protocol_addr, 4);
-  memcpy(&arp_table[arp_table_curr].mac_addr, dst_hardware_addr, 6);
-  if (arp_table_size < 512)
-    arp_table_size++;
-  // wrap around
-  if (arp_table_curr >= 512)
-    arp_table_curr = 0;
+  uint8_t mac[6] = {0};
+  if (arp_lookup(mac, arp_packet->src_protocol_addr) == 0) {
+    arp_lookup_add(arp_packet->src_hardware_addr,
+                   arp_packet->src_protocol_addr);
+  }
 }
 
 void arp_send_packet(uint8_t *dst_hardware_addr, uint8_t *dst_protocol_addr) {
@@ -76,6 +72,7 @@ void arp_send_packet(uint8_t *dst_hardware_addr, uint8_t *dst_protocol_addr) {
   // set source MAC address, IP address (hardcode the IP address as 10.2.2.3
   // until we really get one..)
   get_mac_addr(arp_packet.src_hardware_addr);
+  // TODO
   arp_packet.src_protocol_addr[0] = 10;
   arp_packet.src_protocol_addr[1] = 0;
   arp_packet.src_protocol_addr[2] = 2;
@@ -103,20 +100,20 @@ void arp_send_packet(uint8_t *dst_hardware_addr, uint8_t *dst_protocol_addr) {
                        sizeof(arp_packet_t), ETHERNET_TYPE_ARP);
 }
 
-void arp_lookup_add(uint8_t *ret_hardware_addr, uint8_t *ip_addr) {
+void arp_lookup_add(uint8_t *hardware_addr, uint8_t *ip_addr) {
   memcpy(&arp_table[arp_table_curr].ip_addr, ip_addr, 4);
-  memcpy(&arp_table[arp_table_curr].mac_addr, ret_hardware_addr, 6);
-  if (arp_table_size < 512)
-    arp_table_size++;
+  memcpy(&arp_table[arp_table_curr].mac_addr, hardware_addr, 6);
+  arp_table_curr++;
   // wrap around
-  if (arp_table_curr >= 512)
+  if (arp_table_curr >= ARP_TABLE_MAX)
     arp_table_curr = 0;
 }
 
+// supply a destination mac and an ip to search
+// 0 not found
 int arp_lookup(uint8_t *ret_hardware_addr, uint8_t *ip_addr) {
-  uint32_t ip_entry = *((uint32_t *)(ip_addr));
   for (int i = 0; i < 512; i++) {
-    if (arp_table[i].ip_addr == ip_entry) {
+    if (!memcmp((uint8_t *)&arp_table[i].ip_addr, ip_addr, 4)) {
       memcpy(ret_hardware_addr, &arp_table[i].mac_addr, 6);
       return 1;
     }
@@ -125,10 +122,8 @@ int arp_lookup(uint8_t *ret_hardware_addr, uint8_t *ip_addr) {
 }
 
 void arp_init() {
-  uint8_t broadcast_ip[4];
-  uint8_t broadcast_mac[6];
+  uint8_t broadcast_ip[4] = {0xff};
+  uint8_t broadcast_mac[6] = {0xff};
 
-  memset(broadcast_ip, 0xff, 4);
-  memset(broadcast_mac, 0xff, 6);
   arp_lookup_add(broadcast_mac, broadcast_ip);
-}
+}

net/arp.h

@@ -25,4 +25,5 @@ void arp_handle_packet(arp_packet_t *arp_packet);
 void arp_send_packet(uint8_t *dst_hardware_addr, uint8_t *dst_protocol_addr);
 int arp_lookup(uint8_t *ret_hardware_addr, uint8_t *ip_addr);
 void arp_lookup_add(uint8_t *ret_hardware_addr, uint8_t *ip_addr);
-void arp_init();
+void arp_init();
+void arp_print_table();

net/icmp.c

@@ -83,6 +83,8 @@ void icmp_handle_packet(icmp_packet_t *packet, uint16_t length,
                  src_ip[0], src_ip[1], src_ip[2], src_ip[3], ntohs(packet->id),
                  ntohs(packet->sequence));
 
+    // TODO i could use the same packet and send it back
+    // what the fuck is wrong with the destination mac tho?
     icmp_send_packet(src_ip, ICMP_ECHO_REPLY, 0, packet->id, packet->sequence,
                      packet->data, length - sizeof(icmp_packet_t));
     break;

net/ip.c

@@ -60,18 +60,20 @@ void _ip_send_packet(uint8_t *dst_ip, void *data, uint32_t len,
 
   ip_packet_t *packet = (ip_packet_t *)kmalloc(sizeof(ip_packet_t) + len);
 
-  packet->version_ihl = (4 << 4) | 5; // IPv4, header length 5 words (20 bytes)
+  packet->version_ihl =
+      (IP_IPV4 << 4) | 5; // IPv4, header length 5 words (20 bytes)
   serial_debug("version_ihl = %x", packet->version_ihl);
 
   packet->tos = 0;
 
   uint16_t total_length = sizeof(ip_packet_t) + len;
   packet->length = htons(total_length);
-  serial_debug("total length = %d (%x in network order)", total_length,
-               packet->length);
+  // serial_debug("total length = %d (%x in network order)", total_length,
+  // packet->length);
 
-  static uint16_t ip_id = 0;
-  packet->id = htons(ip_id++);
+  static uint16_t ip_packet_id = 0;
+
+  packet->id = htons(ip_packet_id++);
 
   // no fragmentation
   packet->flags_fragment = htons(0);
@@ -85,22 +87,24 @@ void _ip_send_packet(uint8_t *dst_ip, void *data, uint32_t len,
 
   packet->header_checksum = 0;
   packet->header_checksum = ip_calculate_checksum(packet);
-  serial_debug("ip checksum = %x", ntohs(packet->header_checksum));
+  // serial_debug("ip checksum = %x", ntohs(packet->header_checksum));
 
   memcpy(packet->data, data, len);
 
-  uint8_t dst_mac[6];
-  if (arp_lookup(dst_ip, dst_mac) != 0) {
+  uint8_t dst_mac[6] = {0};
+  if (arp_lookup(dst_mac, dst_ip) == 0) {
     serial_debug("no MAC found for IP %d.%d.%d.%d - sending ARP request",
                  dst_ip[0], dst_ip[1], dst_ip[2], dst_ip[3]);
 
     uint8_t broadcast_mac[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
     arp_send_packet(broadcast_mac, dst_ip);
-    // we could queue the packet here for later transmission
+    // TODO we could queue the packet here for later transmission
+    // cuz we miss a packet now
+    // also i should add the mac to the lut when it arrives
     kfree(packet);
     return;
   }
-
+  // arp_print_table();
   serial_debug("sending to mac %x:%x:%x:%x:%x:%x", dst_mac[0], dst_mac[1],
                dst_mac[2], dst_mac[3], dst_mac[4], dst_mac[5]);
 

net/network.c

@@ -29,8 +29,6 @@ int ethernet_send_packet(uint8_t *dst_mac_addr, uint8_t *data, int len,
   rtl8139_send_packet(frame, sizeof(ethernet_frame_t) + len);
   kfree(frame);
 
-  // qemu_printf("Sent an ethernet packet, it looks like this\n");
-
   return len;
 }