3 files changed, 21 insertions, 15 deletions
diff --git a/kernel/network/ethernet.c b/kernel/network/ethernet.c
index 7b1de7f..dbd1b6d 100644
--- a/kernel/network/ethernet.c
+++ b/kernel/network/ethernet.c
@@ -68,14 +68,14 @@ void handle_ethernet(const u8 *packet, u64 packet_length) {
   }
 }
 
+u8 ethernet_buffer[0x1000];
 void send_ethernet_packet(u8 mac_dst[6], u16 type, u8 *payload,
                           u64 payload_length) {
-  // FIXME: Janky allocation, do this better
   u64 buffer_size =
       sizeof(struct EthernetHeader) + payload_length + sizeof(u32);
-  u8 *buffer = kmalloc(buffer_size);
-  memset(buffer, 0, buffer_size);
-  u8 *buffer_start = buffer;
+  assert(buffer_size < 0x1000);
+  memset(ethernet_buffer, 0, buffer_size);
+  u8 *buffer = ethernet_buffer;
   struct EthernetHeader *eth_header = (struct EthernetHeader *)buffer;
   buffer += sizeof(struct EthernetHeader);
   memcpy(buffer, payload, payload_length);
@@ -84,8 +84,8 @@ void send_ethernet_packet(u8 mac_dst[6], u16 type, u8 *payload,
   memcpy(eth_header->mac_dst, mac_dst, sizeof(u8[6]));
   get_mac_address(eth_header->mac_src);
   eth_header->type = htons(type);
-  *(u32 *)(buffer) = htonl(crc32((const char *)buffer_start, buffer_size - 4));
+  *(u32 *)(buffer) =
+      htonl(crc32((const char *)ethernet_buffer, buffer_size - 4));
 
-  rtl8139_send_data(buffer_start, buffer_size);
-  kfree(buffer_start);
+  rtl8139_send_data(ethernet_buffer, buffer_size);
 }
diff --git a/kernel/network/ipv4.c b/kernel/network/ipv4.c
index 69ceef7..6074141 100644
--- a/kernel/network/ipv4.c
+++ b/kernel/network/ipv4.c
@@ -26,6 +26,7 @@ static u16 ip_checksum(const u16 *data, u16 length) {
   return htons(~acc);
 }
 
+u8 ipv4_buffer[0x1000];
 void send_ipv4_packet(ipv4_t ip, u8 protocol, const u8 *payload, u16 length) {
   u16 header[10];
   header[0] = (4 /*version*/ << 4) | (5 /*IHL*/);
@@ -46,7 +47,8 @@ void send_ipv4_packet(ipv4_t ip, u8 protocol, const u8 *payload, u16 length) {
 
   header[5] = ip_checksum(header, 20);
   u16 packet_length = length + 20;
-  u8 *packet = kmalloc(packet_length);
+  assert(packet_length < sizeof(ipv4_buffer));
+  u8 *packet = ipv4_buffer;
   memcpy(packet, header, 20);
   memcpy(packet + 20, payload, length);
 
@@ -54,7 +56,6 @@ void send_ipv4_packet(ipv4_t ip, u8 protocol, const u8 *payload, u16 length) {
   for (; !get_mac_from_ip(ip, mac);)
     ;
   send_ethernet_packet(mac, 0x0800, packet, packet_length);
-  kfree(packet);
 }
 
 void handle_ipv4(const u8 *payload, u32 packet_length) {
diff --git a/kernel/network/tcp.c b/kernel/network/tcp.c
index 8a56dd1..8717250 100644
--- a/kernel/network/tcp.c
+++ b/kernel/network/tcp.c
@@ -87,6 +87,7 @@ static void tcp_send(struct TcpConnection *con, u8 *buffer, u16 length,
   send_ipv4_packet((ipv4_t){.d = con->outgoing_ip}, 6, buffer, length);
 }
 
+u8 tcp_buffer[0x1000];
 void tcp_send_empty_payload(struct TcpConnection *con, u8 flags) {
   struct TcpHeader header;
   memset(&header, 0, sizeof(header));
@@ -110,8 +111,10 @@ void tcp_send_empty_payload(struct TcpConnection *con, u8 flags) {
   header.checksum = tcp_calculate_checksum(
       ip_address, con->outgoing_ip, (const u8 *)payload, payload_length,
       &header, sizeof(struct TcpHeader) + payload_length);
-  int send_len = sizeof(header) + payload_length;
-  u8 *send_buffer = kmalloc(send_len);
+  u32 send_len = sizeof(header) + payload_length;
+
+  assert(send_len < sizeof(tcp_buffer));
+  u8 *send_buffer = tcp_buffer;
   memcpy(send_buffer, &header, sizeof(header));
   memcpy(send_buffer + sizeof(header), payload, payload_length);
 
@@ -133,13 +136,15 @@ void tcp_close_connection(struct TcpConnection *con) {
   if (TCP_STATE_CLOSE_WAIT == con->state) {
     tcp_send_empty_payload(con, FIN);
     con->state = TCP_STATE_LAST_ACK;
+    tcp_destroy_connection(con); // Client does not appear to respond
+                                 // with last ack?
     return;
   }
   if (TCP_STATE_ESTABLISHED == con->state) {
     // FIXME:
     // Book says it should be FIN but observed network traffic says it
     // should be FIN|ACK?
-    tcp_send_empty_payload(con, FIN | ACK);
+    tcp_send_empty_payload(con, FIN);
     con->state = TCP_STATE_FIN_WAIT1;
     return;
   }
@@ -189,9 +194,9 @@ int send_tcp_packet(struct TcpConnection *con, const u8 *payload,
   header.checksum = tcp_calculate_checksum(
       ip_address, con->outgoing_ip, (const u8 *)payload, payload_length,
       &header, sizeof(struct TcpHeader) + payload_length);
-  int send_len = sizeof(header) + payload_length;
-  u8 *send_buffer = kmalloc(send_len);
-  assert(send_buffer);
+  u32 send_len = sizeof(header) + payload_length;
+  assert(send_len < sizeof(tcp_buffer));
+  u8 *send_buffer = tcp_buffer;
   memcpy(send_buffer, &header, sizeof(header));
   memcpy(send_buffer + sizeof(header), payload, payload_length);