IPv4: Remove an unnecessary copy of each outgoing IPv4 payload

There's no need for send_ipv4() to take a ByteBuffer&&, the data is
immediately cooked into a packet and transmitted. Instead, just pass
it the address+length of whatever buffer we've been using locally.

The more we can reduce the pressure on kmalloc the better. :^)

Kernel/Net/IPv4Socket.cpp

@@ -164,7 +164,7 @@ ssize_t IPv4Socket::sendto(FileDescription&, const void* data, size_t data_lengt
     kprintf("sendto: destination=%s:%u\n", m_peer_address.to_string().characters(), m_peer_port);
 
     if (type() == SOCK_RAW) {
-        adapter->send_ipv4(MACAddress(), m_peer_address, (IPv4Protocol)protocol(), ByteBuffer::copy(data, data_length));
+        adapter->send_ipv4(MACAddress(), m_peer_address, (IPv4Protocol)protocol(), (const u8*)data, data_length);
         return data_length;
     }
 

Kernel/Net/NetworkAdapter.cpp

@@ -56,9 +56,9 @@ void NetworkAdapter::send(const MACAddress& destination, const ARPPacket& packet
     send_raw((u8*)eth, size_in_bytes);
 }
 
-void NetworkAdapter::send_ipv4(const MACAddress& destination_mac, const IPv4Address& destination_ipv4, IPv4Protocol protocol, ByteBuffer&& payload)
+void NetworkAdapter::send_ipv4(const MACAddress& destination_mac, const IPv4Address& destination_ipv4, IPv4Protocol protocol, const u8* payload, size_t payload_size)
 {
-    size_t size_in_bytes = sizeof(EthernetFrameHeader) + sizeof(IPv4Packet) + payload.size();
+    size_t size_in_bytes = sizeof(EthernetFrameHeader) + sizeof(IPv4Packet) + payload_size;
     auto buffer = ByteBuffer::create_zeroed(size_in_bytes);
     auto& eth = *(EthernetFrameHeader*)buffer.pointer();
     eth.set_source(mac_address());
@@ -70,11 +70,11 @@ void NetworkAdapter::send_ipv4(const MACAddress& destination_mac, const IPv4Addr
     ipv4.set_source(ipv4_address());
     ipv4.set_destination(destination_ipv4);
     ipv4.set_protocol((u8)protocol);
-    ipv4.set_length(sizeof(IPv4Packet) + payload.size());
+    ipv4.set_length(sizeof(IPv4Packet) + payload_size);
     ipv4.set_ident(1);
     ipv4.set_ttl(64);
     ipv4.set_checksum(ipv4.compute_checksum());
-    memcpy(ipv4.payload(), payload.pointer(), payload.size());
+    memcpy(ipv4.payload(), payload, payload_size);
     send_raw((const u8*)&eth, size_in_bytes);
 }
 

Kernel/Net/NetworkAdapter.h

@@ -27,7 +27,7 @@ public:
     void set_ipv4_address(const IPv4Address&);
 
     void send(const MACAddress&, const ARPPacket&);
-    void send_ipv4(const MACAddress&, const IPv4Address&, IPv4Protocol, ByteBuffer&& payload);
+    void send_ipv4(const MACAddress&, const IPv4Address&, IPv4Protocol, const u8* payload, size_t payload_size);
 
     RefPtr<KBuffer> dequeue_packet();
 

Kernel/Net/NetworkTask.cpp

@@ -228,7 +228,7 @@ void handle_icmp(const EthernetFrameHeader& eth, int frame_size)
         if (size_t icmp_payload_size = icmp_packet_size - sizeof(ICMPEchoPacket))
             memcpy(response.payload(), request.payload(), icmp_payload_size);
         response.header.set_checksum(internet_checksum(&response, icmp_packet_size));
-        adapter->send_ipv4(eth.source(), ipv4_packet.source(), IPv4Protocol::ICMP, move(buffer));
+        adapter->send_ipv4(eth.source(), ipv4_packet.source(), IPv4Protocol::ICMP, buffer.data(), buffer.size());
     }
 }
 

Kernel/Net/TCPSocket.cpp

@@ -107,7 +107,7 @@ void TCPSocket::send_tcp_packet(u16 flags, const void* payload, int payload_size
         tcp_packet.sequence_number(),
         tcp_packet.ack_number());
 #endif
-    adapter->send_ipv4(MACAddress(), peer_address(), IPv4Protocol::TCP, move(buffer));
+    adapter->send_ipv4(MACAddress(), peer_address(), IPv4Protocol::TCP, buffer.data(), buffer.size());
 }
 
 NetworkOrdered<u16> TCPSocket::compute_tcp_checksum(const IPv4Address& source, const IPv4Address& destination, const TCPPacket& packet, u16 payload_size)

Kernel/Net/UDPSocket.cpp

@@ -70,7 +70,7 @@ int UDPSocket::protocol_send(const void* data, int data_length)
         local_port(),
         peer_address().to_string().characters(),
         peer_port());
-    adapter->send_ipv4(MACAddress(), peer_address(), IPv4Protocol::UDP, move(buffer));
+    adapter->send_ipv4(MACAddress(), peer_address(), IPv4Protocol::UDP, buffer.data(), buffer.size());
     return data_length;
 }