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#include <Kernel/Net/TCPSocket.h>
#include <Kernel/Net/TCP.h>
#include <Kernel/Net/NetworkAdapter.h>
#include <Kernel/Net/Routing.h>
#include <Kernel/Process.h>
#include <Kernel/RandomDevice.h>
Lockable<HashMap<word, TCPSocket*>>& TCPSocket::sockets_by_port()
{
static Lockable<HashMap<word, TCPSocket*>>* s_map;
if (!s_map)
s_map = new Lockable<HashMap<word, TCPSocket*>>;
return *s_map;
}
TCPSocketHandle TCPSocket::from_port(word port)
{
RetainPtr<TCPSocket> socket;
{
LOCKER(sockets_by_port().lock());
auto it = sockets_by_port().resource().find(port);
if (it == sockets_by_port().resource().end())
return { };
socket = (*it).value;
ASSERT(socket);
}
return { move(socket) };
}
TCPSocket::TCPSocket(int protocol)
: IPv4Socket(SOCK_STREAM, protocol)
{
}
TCPSocket::~TCPSocket()
{
LOCKER(sockets_by_port().lock());
sockets_by_port().resource().remove(source_port());
}
Retained<TCPSocket> TCPSocket::create(int protocol)
{
return adopt(*new TCPSocket(protocol));
}
int TCPSocket::protocol_receive(const ByteBuffer& packet_buffer, void* buffer, size_t buffer_size, int flags, sockaddr* addr, socklen_t* addr_length)
{
(void)flags;
(void)addr_length;
ASSERT(!packet_buffer.is_null());
auto& ipv4_packet = *(const IPv4Packet*)(packet_buffer.pointer());
auto& tcp_packet = *static_cast<const TCPPacket*>(ipv4_packet.payload());
size_t payload_size = packet_buffer.size() - sizeof(IPv4Packet) - tcp_packet.header_size();
kprintf("payload_size %u, will it fit in %u?\n", payload_size, buffer_size);
ASSERT(buffer_size >= payload_size);
if (addr) {
auto& ia = *(sockaddr_in*)addr;
ia.sin_port = htons(tcp_packet.destination_port());
}
memcpy(buffer, tcp_packet.payload(), payload_size);
return payload_size;
}
int TCPSocket::protocol_send(const void* data, int data_length)
{
auto* adapter = adapter_for_route_to(destination_address());
if (!adapter)
return -EHOSTUNREACH;
send_tcp_packet(TCPFlags::PUSH | TCPFlags::ACK, data, data_length);
return data_length;
}
void TCPSocket::send_tcp_packet(word flags, const void* payload, int payload_size)
{
// FIXME: Maybe the socket should be bound to an adapter instead of looking it up every time?
auto* adapter = adapter_for_route_to(destination_address());
ASSERT(adapter);
auto buffer = ByteBuffer::create_zeroed(sizeof(TCPPacket) + payload_size);
auto& tcp_packet = *(TCPPacket*)(buffer.pointer());
ASSERT(source_port());
tcp_packet.set_source_port(source_port());
tcp_packet.set_destination_port(destination_port());
tcp_packet.set_window_size(1024);
tcp_packet.set_sequence_number(m_sequence_number);
tcp_packet.set_data_offset(sizeof(TCPPacket) / sizeof(dword));
tcp_packet.set_flags(flags);
if (flags & TCPFlags::ACK)
tcp_packet.set_ack_number(m_ack_number);
if (flags == TCPFlags::SYN) {
++m_sequence_number;
} else {
m_sequence_number += payload_size;
}
memcpy(tcp_packet.payload(), payload, payload_size);
tcp_packet.set_checksum(compute_tcp_checksum(adapter->ipv4_address(), destination_address(), tcp_packet, payload_size));
kprintf("sending tcp packet from %s:%u to %s:%u with (%s %s) seq_no=%u, ack_no=%u\n",
adapter->ipv4_address().to_string().characters(),
source_port(),
destination_address().to_string().characters(),
destination_port(),
tcp_packet.has_syn() ? "SYN" : "",
tcp_packet.has_ack() ? "ACK" : "",
tcp_packet.sequence_number(),
tcp_packet.ack_number()
);
adapter->send_ipv4(MACAddress(), destination_address(), IPv4Protocol::TCP, move(buffer));
}
NetworkOrdered<word> TCPSocket::compute_tcp_checksum(const IPv4Address& source, const IPv4Address& destination, const TCPPacket& packet, word payload_size)
{
struct [[gnu::packed]] PseudoHeader {
IPv4Address source;
IPv4Address destination;
byte zero;
byte protocol;
NetworkOrdered<word> payload_size;
};
PseudoHeader pseudo_header { source, destination, 0, (byte)IPv4Protocol::TCP, sizeof(TCPPacket) + payload_size };
dword checksum = 0;
auto* w = (const NetworkOrdered<word>*)&pseudo_header;
for (size_t i = 0; i < sizeof(pseudo_header) / sizeof(word); ++i) {
checksum += w[i];
if (checksum > 0xffff)
checksum = (checksum >> 16) + (checksum & 0xffff);
}
w = (const NetworkOrdered<word>*)&packet;
for (size_t i = 0; i < sizeof(packet) / sizeof(word); ++i) {
checksum += w[i];
if (checksum > 0xffff)
checksum = (checksum >> 16) + (checksum & 0xffff);
}
ASSERT(packet.data_offset() * 4 == sizeof(TCPPacket));
w = (const NetworkOrdered<word>*)packet.payload();
for (size_t i = 0; i < payload_size / sizeof(word); ++i) {
checksum += w[i];
if (checksum > 0xffff)
checksum = (checksum >> 16) + (checksum & 0xffff);
}
if (payload_size & 1) {
word expanded_byte = ((const byte*)packet.payload())[payload_size - 1] << 8;
checksum += expanded_byte;
if (checksum > 0xffff)
checksum = (checksum >> 16) + (checksum & 0xffff);
}
return ~(checksum & 0xffff);
}
KResult TCPSocket::protocol_connect()
{
auto* adapter = adapter_for_route_to(destination_address());
if (!adapter)
return KResult(-EHOSTUNREACH);
allocate_source_port_if_needed();
m_sequence_number = 0;
m_ack_number = 0;
send_tcp_packet(TCPFlags::SYN);
m_state = State::Connecting;
current->set_blocked_socket(this);
current->block(Thread::BlockedConnect);
ASSERT(is_connected());
return KSuccess;
}
int TCPSocket::protocol_allocate_source_port()
{
static const word first_ephemeral_port = 32768;
static const word last_ephemeral_port = 60999;
static const word ephemeral_port_range_size = last_ephemeral_port - first_ephemeral_port;
word first_scan_port = first_ephemeral_port + (word)(RandomDevice::random_percentage() * ephemeral_port_range_size);
LOCKER(sockets_by_port().lock());
for (word port = first_scan_port;;) {
auto it = sockets_by_port().resource().find(port);
if (it == sockets_by_port().resource().end()) {
set_source_port(port);
sockets_by_port().resource().set(port, this);
return port;
}
++port;
if (port > last_ephemeral_port)
port = first_ephemeral_port;
if (port == first_scan_port)
break;
}
return -EADDRINUSE;
}
bool TCPSocket::protocol_is_disconnected() const
{
return m_state == State::Disconnecting || m_state == State::Disconnected;
}
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