RetroArch/netplay.c
2011-12-25 12:47:47 +01:00

742 lines
20 KiB
C

/* SSNES - A Super Nintendo Entertainment System (SNES) Emulator frontend for libsnes.
* Copyright (C) 2010-2011 - Hans-Kristian Arntzen
*
* Some code herein may be based on code found in BSNES.
*
* SSNES is free software: you can redistribute it and/or modify it under the terms
* of the GNU General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* SSNES is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with SSNES.
* If not, see <http://www.gnu.org/licenses/>.
*/
#ifdef _WIN32
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0501
#endif
#define WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>
#else
#include <sys/select.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <signal.h>
#endif
#include "netplay.h"
#include "general.h"
#include "autosave.h"
#include "dynamic.h"
#include "message.h"
#include <stdlib.h>
#include <string.h>
#ifdef _WIN32
// Woohoo, Winsock has headers from the STONE AGE! :D
#define close(x) closesocket(x)
#define CONST_CAST (const char*)
#define NONCONST_CAST (char*)
#else
#define CONST_CAST
#define NONCONST_CAST
#include <sys/time.h>
#include <unistd.h>
#endif
#define PREV_PTR(x) ((x) == 0 ? handle->buffer_size - 1 : (x) - 1)
#define NEXT_PTR(x) ((x + 1) % handle->buffer_size)
struct delta_frame
{
uint8_t *state;
uint16_t real_input_state;
uint16_t simulated_input_state;
bool is_simulated;
uint16_t self_state;
bool used_real;
};
#define UDP_FRAME_PACKETS 16
struct netplay
{
struct snes_callbacks cbs;
int fd; // TCP connection for state sending, etc. Could perhaps be used for messaging later on. :)
int udp_fd; // UDP connection for game state updates.
unsigned port; // Which port is governed by netplay?
bool has_connection;
struct delta_frame *buffer;
size_t buffer_size;
size_t self_ptr; // Ptr where we are now.
size_t other_ptr; // Points to the last reliable state that self ever had.
size_t read_ptr; // Ptr to where we are reading. Generally, other_ptr <= read_ptr <= self_ptr.
size_t tmp_ptr; // A temporary pointer used on replay.
size_t state_size;
size_t is_replay; // Are we replaying old frames?
bool can_poll; // We don't want to poll several times on a frame.
uint32_t packet_buffer[UDP_FRAME_PACKETS * 2]; // To compat UDP packet loss we also send old data along with the packets.
uint32_t frame_count;
uint32_t read_frame_count;
uint32_t other_frame_count;
struct addrinfo *addr;
struct sockaddr_storage their_addr;
bool has_client_addr;
unsigned timeout_cnt;
};
static void warn_hangup(void)
{
SSNES_WARN("Netplay has disconnected. Will continue without connection ...\n");
if (g_extern.msg_queue)
msg_queue_push(g_extern.msg_queue, "Netplay has disconnected. Will continue without connection.", 0, 480);
}
void input_poll_net(void)
{
if (!netplay_should_skip(g_extern.netplay) && netplay_can_poll(g_extern.netplay))
netplay_poll(g_extern.netplay);
}
void video_frame_net(const uint16_t *data, unsigned width, unsigned height)
{
if (!netplay_should_skip(g_extern.netplay))
netplay_callbacks(g_extern.netplay)->frame_cb(data, width, height);
}
void audio_sample_net(uint16_t left, uint16_t right)
{
if (!netplay_should_skip(g_extern.netplay))
netplay_callbacks(g_extern.netplay)->sample_cb(left, right);
}
int16_t input_state_net(bool port, unsigned device, unsigned index, unsigned id)
{
if (netplay_is_alive(g_extern.netplay))
return netplay_input_state(g_extern.netplay, port, device, index, id);
else
return netplay_callbacks(g_extern.netplay)->state_cb(port, device, index, id);
}
static bool init_tcp_socket(netplay_t *handle, const char *server, uint16_t port)
{
struct addrinfo hints, *res = NULL;
memset(&hints, 0, sizeof(hints));
#ifdef _WIN32 // Lolol, no AF_UNSPEC, wtf.
hints.ai_family = AF_INET;
#else
hints.ai_family = AF_UNSPEC;
#endif
hints.ai_socktype = SOCK_STREAM;
if (!server)
hints.ai_flags = AI_PASSIVE;
char port_buf[16];
snprintf(port_buf, sizeof(port_buf), "%hu", (unsigned short)port);
if (getaddrinfo(server, port_buf, &hints, &res) < 0)
return false;
if (!res)
return false;
handle->fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (handle->fd < 0)
{
SSNES_ERR("Failed to init socket...\n");
if (res)
freeaddrinfo(res);
return false;
}
if (server)
{
if (connect(handle->fd, res->ai_addr, res->ai_addrlen) < 0)
{
SSNES_ERR("Failed to connect to server.\n");
close(handle->fd);
freeaddrinfo(res);
return false;
}
}
else
{
int yes = 1;
setsockopt(handle->fd, SOL_SOCKET, SO_REUSEADDR, CONST_CAST &yes, sizeof(int));
if (bind(handle->fd, res->ai_addr, res->ai_addrlen) < 0 || listen(handle->fd, 1) < 0)
{
SSNES_ERR("Failed to bind socket.\n");
close(handle->fd);
freeaddrinfo(res);
return false;
}
int new_fd = accept(handle->fd, NULL, NULL);
if (new_fd < 0)
{
SSNES_ERR("Failed to accept socket.\n");
close(handle->fd);
freeaddrinfo(res);
return false;
}
close(handle->fd);
handle->fd = new_fd;
}
freeaddrinfo(res);
return true;
}
static bool init_udp_socket(netplay_t *handle, const char *server, uint16_t port)
{
struct addrinfo hints;
memset(&hints, 0, sizeof(hints));
#ifdef _WIN32 // Lolol, no AF_UNSPEC, wtf.
hints.ai_family = AF_INET;
#else
hints.ai_family = AF_UNSPEC;
#endif
hints.ai_socktype = SOCK_DGRAM;
if (!server)
hints.ai_flags = AI_PASSIVE;
char port_buf[16];
snprintf(port_buf, sizeof(port_buf), "%hu", (unsigned short)port);
if (getaddrinfo(server, port_buf, &hints, &handle->addr) < 0)
return false;
if (!handle->addr)
return false;
handle->udp_fd = socket(handle->addr->ai_family, handle->addr->ai_socktype, handle->addr->ai_protocol);
if (handle->udp_fd < 0)
{
SSNES_ERR("Failed to init socket...\n");
return false;
}
if (!server)
{
// Note sure if we have to do this for UDP, but hey :)
int yes = 1;
setsockopt(handle->udp_fd, SOL_SOCKET, SO_REUSEADDR, CONST_CAST &yes, sizeof(int));
if (bind(handle->udp_fd, handle->addr->ai_addr, handle->addr->ai_addrlen) < 0)
{
SSNES_ERR("Failed to bind socket.\n");
close(handle->udp_fd);
}
freeaddrinfo(handle->addr);
handle->addr = NULL;
}
return true;
}
static bool init_socket(netplay_t *handle, const char *server, uint16_t port)
{
#ifdef _WIN32
WSADATA wsaData;
if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
{
WSACleanup();
return false;
}
#else
signal(SIGPIPE, SIG_IGN); // Do not like SIGPIPE killing our app :(
#endif
if (!init_tcp_socket(handle, server, port))
return false;
if (!init_udp_socket(handle, server, port))
return false;
return true;
}
bool netplay_can_poll(netplay_t *handle)
{
return handle->can_poll;
}
// Not really a hash, but should be enough to differentiate implementations from each other.
// Subtle differences in the implementation will not be possible to spot.
// The alternative would have been checking serialization sizes, but it was troublesome for cross platform compat.
static uint32_t implementation_magic_value(void)
{
uint32_t res = 0;
res |= (psnes_library_revision_major() & 0xf) << 0;
res |= (psnes_library_revision_minor() & 0xf) << 4;
// Shouldn't really use this, but oh well :) It'll do the job.
const char *lib = psnes_library_id();
size_t len = strlen(lib);
for (size_t i = 0; i < len; i++)
res ^= lib[i] << (i & 0xf);
return res;
}
static bool send_info(netplay_t *handle)
{
uint32_t header[3] = { htonl(g_extern.cart_crc), htonl(implementation_magic_value()), htonl(psnes_get_memory_size(SNES_MEMORY_CARTRIDGE_RAM)) };
if (send(handle->fd, CONST_CAST header, sizeof(header), 0) != sizeof(header))
return false;
// Get SRAM data from Player 1 :)
uint8_t *sram = psnes_get_memory_data(SNES_MEMORY_CARTRIDGE_RAM);
unsigned sram_size = psnes_get_memory_size(SNES_MEMORY_CARTRIDGE_RAM);
while (sram_size > 0)
{
ssize_t ret = recv(handle->fd, NONCONST_CAST sram, sram_size, 0);
if (ret <= 0)
{
SSNES_ERR("Failed to receive SRAM data from host.\n");
return false;
}
sram += ret;
sram_size -= ret;
}
return true;
}
static bool get_info(netplay_t *handle)
{
uint32_t header[3];
if (recv(handle->fd, NONCONST_CAST header, sizeof(header), 0) != sizeof(header))
{
SSNES_ERR("Failed to receive header from client.\n");
return false;
}
if (g_extern.cart_crc != ntohl(header[0]))
{
SSNES_ERR("Cart CRC32s differ! Cannot use different games!\n");
return false;
}
if (implementation_magic_value() != ntohl(header[1]))
{
SSNES_ERR("Implementations differ, make sure you're using exact same libsnes implementations!\n");
return false;
}
if (psnes_get_memory_size(SNES_MEMORY_CARTRIDGE_RAM) != ntohl(header[2]))
{
SSNES_ERR("Cartridge SRAM sizes do not correspond!\n");
return false;
}
// Send SRAM data to our Player 2 :)
const uint8_t *sram = psnes_get_memory_data(SNES_MEMORY_CARTRIDGE_RAM);
unsigned sram_size = psnes_get_memory_size(SNES_MEMORY_CARTRIDGE_RAM);
while (sram_size > 0)
{
ssize_t ret = send(handle->fd, CONST_CAST sram, sram_size, 0);
if (ret <= 0)
{
SSNES_ERR("Failed to send SRAM data to client.\n");
return false;
}
sram += ret;
sram_size -= ret;
}
return true;
}
static void init_buffers(netplay_t *handle)
{
handle->buffer = (struct delta_frame*)calloc(handle->buffer_size, sizeof(*handle->buffer));
handle->state_size = psnes_serialize_size();
for (unsigned i = 0; i < handle->buffer_size; i++)
{
handle->buffer[i].state = (uint8_t*)malloc(handle->state_size);
handle->buffer[i].is_simulated = true;
}
}
netplay_t *netplay_new(const char *server, uint16_t port, unsigned frames, const struct snes_callbacks *cb)
{
if (frames > UDP_FRAME_PACKETS)
frames = UDP_FRAME_PACKETS;
netplay_t *handle = (netplay_t*)calloc(1, sizeof(*handle));
if (!handle)
return NULL;
handle->cbs = *cb;
handle->port = server ? 0 : 1;
if (!init_socket(handle, server, port))
{
free(handle);
return NULL;
}
if (server)
{
if (!send_info(handle))
{
close(handle->fd);
free(handle);
return NULL;
}
}
else
{
if (!get_info(handle))
{
close(handle->fd);
free(handle);
return NULL;
}
}
handle->buffer_size = frames + 1;
init_buffers(handle);
handle->has_connection = true;
return handle;
}
bool netplay_is_alive(netplay_t *handle)
{
return handle->has_connection;
}
static bool send_chunk(netplay_t *handle)
{
const struct sockaddr *addr = NULL;
if (handle->addr)
addr = handle->addr->ai_addr;
else if (handle->has_client_addr)
addr = (const struct sockaddr*)&handle->their_addr;
if (addr)
{
if (sendto(handle->udp_fd, CONST_CAST handle->packet_buffer, sizeof(handle->packet_buffer), 0, addr, sizeof(struct sockaddr)) != sizeof(handle->packet_buffer))
{
warn_hangup();
handle->has_connection = false;
return false;
}
}
return true;
}
#define MAX_RETRIES 16
#define RETRY_MS 500
static int poll_input(netplay_t *handle, bool block)
{
int max_fd = (handle->fd > handle->udp_fd ? handle->fd : handle->udp_fd) + 1;
struct timeval tv = {0};
tv.tv_sec = 0;
tv.tv_usec = block ? (RETRY_MS * 1000) : 0;
do
{
handle->timeout_cnt++;
// select() does not take pointer to const struct timeval.
// Technically possible for select() to modify tmp_tv, so we go paranoia mode.
struct timeval tmp_tv = tv;
fd_set fds;
FD_ZERO(&fds);
FD_SET(handle->udp_fd, &fds);
FD_SET(handle->fd, &fds);
if (select(max_fd, &fds, NULL, NULL, &tmp_tv) < 0)
return -1;
// Somewhat hacky, but we aren't using the TCP connection for anything useful atm.
// Will probably add some proper messaging system here later.
if (FD_ISSET(handle->fd, &fds))
return -1;
if (FD_ISSET(handle->udp_fd, &fds))
return 1;
if (block && !send_chunk(handle))
{
warn_hangup();
handle->has_connection = false;
return -1;
}
if (block)
{
SSNES_LOG("Network is stalling, resending packet... Count %u of %d ...\n",
handle->timeout_cnt, MAX_RETRIES);
}
} while ((handle->timeout_cnt < MAX_RETRIES) && block);
if (block)
return -1;
return 0;
}
// Grab our own input state and send this over the network.
static bool get_self_input_state(netplay_t *handle)
{
struct delta_frame *ptr = &handle->buffer[handle->self_ptr];
uint32_t state = 0;
if (handle->frame_count > 0) // First frame we always give zero input since relying on input from first frame screws up when we use -F 0.
{
snes_input_state_t cb = handle->cbs.state_cb;
for (unsigned i = 0; i <= 11; i++)
{
int16_t tmp = cb(g_settings.input.netplay_client_swap_input ? 0 : !handle->port, SNES_DEVICE_JOYPAD, 0, i);
state |= tmp ? 1 << i : 0;
}
}
memmove(handle->packet_buffer, handle->packet_buffer + 2, sizeof (handle->packet_buffer) - 2 * sizeof(uint32_t));
handle->packet_buffer[(UDP_FRAME_PACKETS - 1) * 2] = htonl(handle->frame_count);
handle->packet_buffer[(UDP_FRAME_PACKETS - 1) * 2 + 1] = htonl(state);
if (!send_chunk(handle))
{
warn_hangup();
handle->has_connection = false;
return false;
}
ptr->self_state = state;
handle->self_ptr = NEXT_PTR(handle->self_ptr);
return true;
}
// TODO: Somewhat better prediction. :P
static void simulate_input(netplay_t *handle)
{
size_t ptr = PREV_PTR(handle->self_ptr);
size_t prev = PREV_PTR(handle->read_ptr);
handle->buffer[ptr].simulated_input_state = handle->buffer[prev].real_input_state;
handle->buffer[ptr].is_simulated = true;
handle->buffer[ptr].used_real = false;
}
static void parse_packet(netplay_t *handle, uint32_t *buffer, unsigned size)
{
for (unsigned i = 0; i < size * 2; i++)
buffer[i] = ntohl(buffer[i]);
for (unsigned i = 0; i < size && handle->read_frame_count <= handle->frame_count; i++)
{
uint32_t frame = buffer[2 * i + 0];
uint32_t state = buffer[2 * i + 1];
if (frame == handle->read_frame_count)
{
handle->buffer[handle->read_ptr].is_simulated = false;
handle->buffer[handle->read_ptr].real_input_state = state;
handle->read_ptr = NEXT_PTR(handle->read_ptr);
handle->read_frame_count++;
handle->timeout_cnt = 0;
}
}
}
static bool receive_data(netplay_t *handle, uint32_t *buffer, size_t size)
{
socklen_t addrlen = sizeof(handle->their_addr);
if (recvfrom(handle->udp_fd, NONCONST_CAST buffer, size, 0, (struct sockaddr*)&handle->their_addr, &addrlen) != (ssize_t)size)
return false;
handle->has_client_addr = true;
return true;
}
// Poll network to see if we have anything new. If our network buffer is full, we simply have to block for new input data.
bool netplay_poll(netplay_t *handle)
{
if (!handle->has_connection)
return false;
handle->can_poll = false;
if (!get_self_input_state(handle))
return false;
// We skip reading the first frame so the host has a chance to grab our host info so we don't block forever :')
if (handle->frame_count == 0)
{
handle->buffer[0].used_real = true;
handle->buffer[0].is_simulated = false;
handle->buffer[0].real_input_state = 0;
handle->read_ptr = NEXT_PTR(handle->read_ptr);
handle->read_frame_count++;
return true;
}
// We might have reached the end of the buffer, where we simply have to block.
int res = poll_input(handle, handle->other_ptr == handle->self_ptr);
if (res == -1)
{
handle->has_connection = false;
warn_hangup();
return false;
}
if (res == 1)
{
uint32_t first_read = handle->read_frame_count;
do
{
uint32_t buffer[UDP_FRAME_PACKETS * 2];
if (!receive_data(handle, buffer, sizeof(buffer)))
{
warn_hangup();
handle->has_connection = false;
return false;
}
parse_packet(handle, buffer, UDP_FRAME_PACKETS);
} while ((handle->read_frame_count <= handle->frame_count) &&
poll_input(handle, (handle->other_ptr == handle->self_ptr) &&
(first_read == handle->read_frame_count)) == 1);
}
else
{
// Cannot allow this. Should not happen though.
if (handle->self_ptr == handle->other_ptr)
{
warn_hangup();
return false;
}
}
//fprintf(stderr, "After poll: Other ptr: %lu, Read ptr: %lu, Self ptr: %lu\n", handle->other_ptr, handle->read_ptr, handle->self_ptr);
if (handle->read_ptr != handle->self_ptr)
simulate_input(handle);
else
handle->buffer[PREV_PTR(handle->self_ptr)].used_real = true;
return true;
}
int16_t netplay_input_state(netplay_t *handle, bool port, unsigned device, unsigned index, unsigned id)
{
uint16_t input_state = 0;
size_t ptr = 0;
if (handle->is_replay)
ptr = handle->tmp_ptr;
else
ptr = PREV_PTR(handle->self_ptr);
if ((port ? 1 : 0) == handle->port)
{
if (handle->buffer[ptr].is_simulated)
input_state = handle->buffer[ptr].simulated_input_state;
else
input_state = handle->buffer[ptr].real_input_state;
}
else
input_state = handle->buffer[ptr].self_state;
return ((1 << id) & input_state) ? 1 : 0;
}
void netplay_free(netplay_t *handle)
{
close(handle->fd);
close(handle->udp_fd);
for (unsigned i = 0; i < handle->buffer_size; i++)
free(handle->buffer[i].state);
free(handle->buffer);
if (handle->addr)
freeaddrinfo(handle->addr);
free(handle);
}
const struct snes_callbacks* netplay_callbacks(netplay_t *handle)
{
return &handle->cbs;
}
bool netplay_should_skip(netplay_t *handle)
{
return handle->is_replay && handle->has_connection;
}
void netplay_pre_frame(netplay_t *handle)
{
psnes_serialize(handle->buffer[handle->self_ptr].state, handle->state_size);
handle->can_poll = true;
input_poll_net();
}
// Here we check if we have new input and replay from recorded input.
void netplay_post_frame(netplay_t *handle)
{
handle->frame_count++;
// Nothing to do...
if (handle->other_frame_count == handle->read_frame_count)
return;
// Skip ahead if we predicted correctly. Skip until our simulation failed.
while (handle->other_frame_count < handle->read_frame_count)
{
struct delta_frame *ptr = &handle->buffer[handle->other_ptr];
if ((ptr->simulated_input_state != ptr->real_input_state) && !ptr->used_real)
break;
handle->other_ptr = NEXT_PTR(handle->other_ptr);
handle->other_frame_count++;
}
if (handle->other_frame_count < handle->read_frame_count)
{
// Replay frames
handle->is_replay = true;
handle->tmp_ptr = handle->other_ptr;
psnes_unserialize(handle->buffer[handle->other_ptr].state, handle->state_size);
bool first = true;
while (first || (handle->tmp_ptr != handle->self_ptr))
{
psnes_serialize(handle->buffer[handle->tmp_ptr].state, handle->state_size);
#ifdef HAVE_THREADS
lock_autosave();
#endif
psnes_run();
#ifdef HAVE_THREADS
unlock_autosave();
#endif
handle->tmp_ptr = NEXT_PTR(handle->tmp_ptr);
first = false;
}
handle->other_ptr = handle->read_ptr;
handle->other_frame_count = handle->read_frame_count;
handle->is_replay = false;
}
}