Networking: Split network packets if they are too large

4 files changed, 16 insertions, 6 deletions

diff --git a/kernel/drivers/rtl8139.c b/kernel/drivers/rtl8139.c
index 4b53ef4..dd81533 100644
--- a/kernel/drivers/rtl8139.c
+++ b/kernel/drivers/rtl8139.c
@@ -103,12 +103,16 @@ __attribute__((interrupt)) void rtl8139_handler(void *regs) {
   EOI(0xB);
 }
 
-int rtl8139_send_data(u8 *data, u16 data_size) {
+void rtl8139_send_data(u8 *data, u16 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)
-    return 0;
+  if (data_size > 0x1000) {
+    rtl8139_send_data(data, 0x1000);
+    data += 0x1000;
+    data_size -= 0x1000;
+    return rtl8139_send_data(data, data_size);
+  }
   if (send_buffers_loop > 3) {
     send_buffers_loop = 0;
   }
@@ -117,7 +121,6 @@ int rtl8139_send_data(u8 *data, u16 data_size) {
        (u32)virtual_to_physical(send_buffers[send_buffers_loop], NULL));
   outl(device->gen.base_mem_io + 0x10 + send_buffers_loop * 4, data_size);
   send_buffers_loop += 1;
-  return 1;
 }
 
 void get_mac_address(u8 mac[6]) {
diff --git a/kernel/drivers/rtl8139.h b/kernel/drivers/rtl8139.h
index 7cbca4b..c61e6de 100644
--- a/kernel/drivers/rtl8139.h
+++ b/kernel/drivers/rtl8139.h
@@ -1,4 +1,4 @@
 #include <typedefs.h>
 void get_mac_address(u8 mac[6]);
 void rtl8139_init(void);
-int rtl8139_send_data(u8 *data, u16 data_size);
+void rtl8139_send_data(u8 *data, u16 data_size);
diff --git a/kernel/network/ethernet.c b/kernel/network/ethernet.c
index 6255ecb..940802f 100644
--- a/kernel/network/ethernet.c
+++ b/kernel/network/ethernet.c
@@ -67,6 +67,7 @@ void handle_ethernet(const u8 *packet, u64 packet_length) {
 
 void send_ethernet_packet(u8 mac_dst[6], u16 type, u8 *payload,
                           u64 payload_length) {
+  assert(payload_length <= 1500);
   // FIXME: Janky allocation, do this better
   u64 buffer_size =
       sizeof(struct ETHERNET_HEADER) + payload_length + sizeof(u32);
@@ -82,6 +83,6 @@ void send_ethernet_packet(u8 mac_dst[6], u16 type, u8 *payload,
   eth_header->type = htons(type);
   *(u32 *)(buffer) = htonl(crc32((const char *)buffer_start, buffer_size - 4));
 
-  assert(rtl8139_send_data(buffer_start, buffer_size));
+  rtl8139_send_data(buffer_start, buffer_size);
   kfree(buffer_start);
 }
diff --git a/kernel/network/tcp.c b/kernel/network/tcp.c
index 14bd0cb..e4b0891 100644
--- a/kernel/network/tcp.c
+++ b/kernel/network/tcp.c
@@ -113,6 +113,12 @@ void tcp_close_connection(struct INCOMING_TCP_CONNECTION *inc) {
 
 void send_tcp_packet(struct INCOMING_TCP_CONNECTION *inc, u8 *payload,
                      u16 payload_length) {
+  if (payload_length > 1500 - 20 - sizeof(struct TCP_HEADER)) {
+    send_tcp_packet(inc, payload, 1500 - 20 - sizeof(struct TCP_HEADER));
+    payload_length -= 1500 - 20 - sizeof(struct TCP_HEADER);
+    payload += 1500 - 20 - sizeof(struct TCP_HEADER);
+    return  send_tcp_packet(inc, payload, payload_length);
+  }
   struct TCP_HEADER header = {0};
   header.src_port = htons(inc->dst_port);
   header.dst_port = inc->n_port;