RetroArch/netplay.c
2012-01-24 23:14:11 +01:00

1406 lines
36 KiB
C

/* SSNES - A Super Nintendo Entertainment System (SNES) Emulator frontend for libsnes.
* Copyright (C) 2010-2012 - 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/>.
*/
#if defined(_WIN32) && !defined(_XBOX)
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0501
#endif
#define WIN32_LEAN_AND_MEAN
#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>
#elif defined(_XBOX)
#include <Xtl.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>
#ifdef __CELLOS_LV2__
#include <cell/sysmodule.h>
#include <netex/net.h>
#else
#include <signal.h>
#endif
#endif
#include "netplay.h"
#include "general.h"
#include "autosave.h"
#include "dynamic.h"
#include "message.h"
#include <stdlib.h>
#include <string.h>
#include "netplay_compat.h"
// Checks if input port/index is controlled by netplay or not.
static bool netplay_is_alive(netplay_t *handle);
static bool netplay_poll(netplay_t *handle);
static int16_t netplay_input_state(netplay_t *handle, bool port, unsigned device, unsigned index, unsigned id);
// If we're fast-forward replaying to resync, check if we should actually show frame.
static bool netplay_should_skip(netplay_t *handle);
static bool netplay_can_poll(netplay_t *handle);
static const struct snes_callbacks* netplay_callbacks(netplay_t *handle);
static void netplay_set_spectate_input(netplay_t *handle, int16_t input);
static bool netplay_send_cmd(netplay_t *handle, uint32_t cmd, const void *data, size_t size);
static bool netplay_get_cmd(netplay_t *handle);
#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
#define MAX_SPECTATORS 16
#define NETPLAY_CMD_ACK 0
#define NETPLAY_CMD_NAK 1
#define NETPLAY_CMD_FLIP_PLAYERS 2
struct netplay
{
char nick[32];
char other_nick[32];
struct sockaddr_storage other_addr;
struct snes_callbacks cbs;
int fd; // TCP connection for state sending, etc. Also used for commands.
int udp_fd; // UDP connection for game state updates.
unsigned port; // Which port is governed by netplay (other player)?
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;
bool 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;
uint32_t tmp_frame_count;
struct addrinfo *addr;
struct sockaddr_storage their_addr;
bool has_client_addr;
unsigned timeout_cnt;
// Spectating.
bool spectate;
bool spectate_client;
int spectate_fds[MAX_SPECTATORS];
uint16_t *spectate_input;
size_t spectate_input_ptr;
size_t spectate_input_size;
// Player flipping
// Flipping state. If ptr >= flip_frame, we apply the flip.
// If not, we apply the opposite, effectively creating a trigger point.
// To avoid collition we need to make sure our client/host is synced up well after flip_frame
// before allowing another flip.
bool flip;
uint32_t flip_frame;
};
static bool send_all(int fd, const void *data_, size_t size)
{
const uint8_t *data = (const uint8_t*)data_;
while (size)
{
ssize_t ret = send(fd, CONST_CAST data, size, 0);
if (ret <= 0)
return false;
data += ret;
size -= ret;
}
return true;
}
static bool recv_all(int fd, void *data_, size_t size)
{
uint8_t *data = (uint8_t*)data_;
while (size)
{
ssize_t ret = recv(fd, NONCONST_CAST data, size, 0);
if (ret <= 0)
return false;
data += ret;
size -= ret;
}
return true;
}
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);
}
#ifndef HAVE_SOCKET_LEGACY
// Custom inet_ntop. Win32 doesn't seem to support this ...
static void log_connection(const struct sockaddr_storage *their_addr,
unsigned slot, const char *nick)
{
union
{
const struct sockaddr_storage *storage;
const struct sockaddr_in *v4;
const struct sockaddr_in6 *v6;
} u;
u.storage = their_addr;
const char *str = NULL;
char buf_v4[INET_ADDRSTRLEN] = {0};
char buf_v6[INET6_ADDRSTRLEN] = {0};
if (their_addr->ss_family == AF_INET)
{
str = buf_v4;
struct sockaddr_in in;
memset(&in, 0, sizeof(in));
in.sin_family = AF_INET;
memcpy(&in.sin_addr, &u.v4->sin_addr, sizeof(struct in_addr));
getnameinfo((struct sockaddr*)&in, sizeof(struct sockaddr_in), buf_v4, sizeof(buf_v4),
NULL, 0, NI_NUMERICHOST);
}
else if (their_addr->ss_family == AF_INET6)
{
str = buf_v6;
struct sockaddr_in6 in;
memset(&in, 0, sizeof(in));
in.sin6_family = AF_INET6;
memcpy(&in.sin6_addr, &u.v6->sin6_addr, sizeof(struct in6_addr));
getnameinfo((struct sockaddr*)&in, sizeof(struct sockaddr_in6),
buf_v6, sizeof(buf_v6), NULL, 0, NI_NUMERICHOST);
}
if (str)
{
char msg[512];
snprintf(msg, sizeof(msg), "Got connection from: \"%s (%s)\" (#%u)", nick, str, slot);
msg_queue_push(g_extern.msg_queue, msg, 1, 180);
SSNES_LOG("%s\n", msg);
}
}
#endif
static bool init_tcp_socket(netplay_t *handle, const char *server, uint16_t port, bool spectate)
{
struct addrinfo hints, *res = NULL;
memset(&hints, 0, sizeof(hints));
#if defined(_WIN32) || defined(HAVE_SOCKET_LEGACY)
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);
handle->fd = -1;
freeaddrinfo(res);
return false;
}
}
else if (handle->spectate)
{
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, MAX_SPECTATORS) < 0)
{
SSNES_ERR("Failed to bind socket.\n");
close(handle->fd);
handle->fd = -1;
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);
handle->fd = -1;
freeaddrinfo(res);
return false;
}
socklen_t addr_size = sizeof(handle->other_addr);
int new_fd = accept(handle->fd,
(struct sockaddr*)&handle->other_addr, &addr_size);
if (new_fd < 0)
{
SSNES_ERR("Failed to accept socket.\n");
close(handle->fd);
handle->fd = -1;
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));
#if defined(_WIN32) || defined(HAVE_SOCKET_LEGACY)
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);
handle->udp_fd = -1;
}
freeaddrinfo(handle->addr);
handle->addr = NULL;
}
return true;
}
// Platform specific socket library init.
static bool init_network(void)
{
static bool inited = false;
if (inited)
return true;
#if defined(_WIN32)
WSADATA wsaData;
if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
{
WSACleanup();
return false;
}
#elif defined(__CELLOS_LV2__)
cellSysmoduleLoadModule(CELL_SYSMODULE_NET);
sys_net_initialize_network();
#else
signal(SIGPIPE, SIG_IGN); // Do not like SIGPIPE killing our app :(
#endif
inited = true;
return true;
}
static bool init_socket(netplay_t *handle, const char *server, uint16_t port)
{
if (!init_network())
return false;
if (!init_tcp_socket(handle, server, port, handle->spectate))
return false;
if (!handle->spectate && !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;
unsigned major = psnes_library_revision_major();
unsigned minor = psnes_library_revision_minor();
res |= (major & 0xf) << 0;
res |= (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);
const char *ver = PACKAGE_VERSION;
len = strlen(ver);
for (size_t i = 0; i < len; i++)
res ^= ver[i] << ((i & 0xf) + 16);
return res;
}
static bool send_nickname(netplay_t *handle, int fd)
{
uint8_t nick_size = strlen(handle->nick);
if (!send_all(fd, &nick_size, sizeof(nick_size)))
{
SSNES_ERR("Failed to send nick size.\n");
return false;
}
if (!send_all(fd, handle->nick, nick_size))
{
SSNES_ERR("Failed to send nick.\n");
return false;
}
return true;
}
static bool get_nickname(netplay_t *handle, int fd)
{
uint8_t nick_size;
if (!recv_all(fd, &nick_size, sizeof(nick_size)))
{
SSNES_ERR("Failed to receive nick size from host.\n");
return false;
}
if (nick_size >= sizeof(handle->other_nick))
{
SSNES_ERR("Invalid nick size.\n");
return false;
}
if (!recv_all(fd, handle->other_nick, nick_size))
{
SSNES_ERR("Failed to receive nick.\n");
return false;
}
return true;
}
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_all(handle->fd, header, sizeof(header)))
return false;
if (!send_nickname(handle, handle->fd))
{
SSNES_ERR("Failed to send nick to host.\n");
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);
if (!recv_all(handle->fd, sram, sram_size))
{
SSNES_ERR("Failed to receive SRAM data from host.\n");
return false;
}
if (!get_nickname(handle, handle->fd))
{
SSNES_ERR("Failed to receive nick from host.\n");
return false;
}
char msg[512];
snprintf(msg, sizeof(msg), "Connected to: \"%s\"", handle->other_nick);
SSNES_LOG("%s\n", msg);
msg_queue_push(g_extern.msg_queue, msg, 1, 180);
return true;
}
static bool get_info(netplay_t *handle)
{
uint32_t header[3];
if (!recv_all(handle->fd, header, 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 and SSNES version!\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;
}
if (!get_nickname(handle, handle->fd))
{
SSNES_ERR("Failed to get nickname from client.\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);
if (!send_all(handle->fd, sram, sram_size))
{
SSNES_ERR("Failed to send SRAM data to client.\n");
return false;
}
if (!send_nickname(handle, handle->fd))
{
SSNES_ERR("Failed to send nickname to client.\n");
return false;
}
#ifndef HAVE_SOCKET_LEGACY
log_connection(&handle->other_addr, 0, handle->other_nick);
#endif
return true;
}
static bool get_info_spectate(netplay_t *handle)
{
if (!send_nickname(handle, handle->fd))
{
SSNES_ERR("Failed to send nickname to host!\n");
return false;
}
if (!get_nickname(handle, handle->fd))
{
SSNES_ERR("Failed to receive nickname from host!\n");
return false;
}
char msg[512];
snprintf(msg, sizeof(msg), "Connected to \"%s\"", handle->other_nick);
msg_queue_push(g_extern.msg_queue, msg, 1, 180);
SSNES_LOG("%s\n", msg);
uint32_t header[4];
if (!recv_all(handle->fd, header, sizeof(header)))
{
SSNES_ERR("Cannot get header from host!\n");
return false;
}
unsigned save_state_size = psnes_serialize_size();
if (!bsv_parse_header(header, implementation_magic_value()))
{
SSNES_ERR("Received invalid BSV header from host!\n");
return false;
}
uint8_t *buf = (uint8_t*)malloc(save_state_size);
if (!buf)
return false;
size_t size = save_state_size;
uint8_t *tmp_buf = buf;
if (!recv_all(handle->fd, tmp_buf, size))
{
SSNES_ERR("Failed to receive save state from host!\n");
free(tmp_buf);
return false;
}
bool ret = true;
if (save_state_size)
ret = psnes_unserialize(buf, save_state_size);
free(buf);
return ret;
}
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,
bool spectate,
const char *nick)
{
(void)spectate;
if (frames > UDP_FRAME_PACKETS)
frames = UDP_FRAME_PACKETS;
netplay_t *handle = (netplay_t*)calloc(1, sizeof(*handle));
if (!handle)
return NULL;
handle->fd = -1;
handle->udp_fd = -1;
handle->cbs = *cb;
handle->port = server ? 0 : 1;
handle->spectate = spectate;
handle->spectate_client = server != NULL;
strlcpy(handle->nick, nick, sizeof(handle->nick));
if (!init_socket(handle, server, port))
{
free(handle);
return NULL;
}
if (spectate)
{
if (server)
{
if (!get_info_spectate(handle))
goto error;
}
for (unsigned i = 0; i < MAX_SPECTATORS; i++)
handle->spectate_fds[i] = -1;
}
else
{
if (server)
{
if (!send_info(handle))
goto error;
}
else
{
if (!get_info(handle))
goto error;
}
handle->buffer_size = frames + 1;
init_buffers(handle);
handle->has_connection = true;
}
return handle;
error:
if (handle->fd >= 0)
close(handle->fd);
if (handle->udp_fd >= 0)
close(handle->udp_fd);
free(handle);
return NULL;
}
static 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.
if (FD_ISSET(handle->fd, &fds) && !netplay_get_cmd(handle))
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 < SSNES_FIRST_META_KEY; 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.
static 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;
}
}
if (handle->read_ptr != handle->self_ptr)
simulate_input(handle);
else
handle->buffer[PREV_PTR(handle->self_ptr)].used_real = true;
return true;
}
static bool netplay_send_cmd(netplay_t *handle, uint32_t cmd, const void *data, size_t size)
{
cmd = (cmd << 16) | (size & 0xffff);
cmd = htonl(cmd);
if (!send_all(handle->fd, &cmd, sizeof(cmd)))
return false;
if (!send_all(handle->fd, data, size))
return false;
return true;
}
static bool netplay_cmd_ack(netplay_t *handle)
{
uint32_t cmd = htonl(NETPLAY_CMD_ACK);
return send_all(handle->fd, &cmd, sizeof(cmd));
}
static bool netplay_cmd_nak(netplay_t *handle)
{
uint32_t cmd = htonl(NETPLAY_CMD_NAK);
return send_all(handle->fd, &cmd, sizeof(cmd));
}
static bool netplay_get_response(netplay_t *handle)
{
uint32_t response;
if (!recv_all(handle->fd, &response, sizeof(response)))
return false;
return ntohl(response) == NETPLAY_CMD_ACK;
}
static bool netplay_get_cmd(netplay_t *handle)
{
uint32_t cmd;
if (!recv_all(handle->fd, &cmd, sizeof(cmd)))
return false;
cmd = ntohl(cmd);
size_t cmd_size = cmd & 0xffff;
cmd = cmd >> 16;
switch (cmd)
{
case NETPLAY_CMD_FLIP_PLAYERS:
{
if (cmd_size != sizeof(uint32_t))
{
SSNES_ERR("CMD_FLIP_PLAYERS has unexpected command size!\n");
return netplay_cmd_nak(handle);
}
uint32_t flip_frame;
if (!recv_all(handle->fd, &flip_frame, sizeof(flip_frame)))
{
SSNES_ERR("Failed to receive CMD_FLIP_PLAYERS argument!\n");
return netplay_cmd_nak(handle);
}
flip_frame = ntohl(flip_frame);
if (flip_frame < handle->flip_frame)
{
SSNES_ERR("Host asked us to flip players in the past. Not possible ...\n");
return netplay_cmd_nak(handle);
}
handle->flip ^= true;
handle->flip_frame = flip_frame;
SSNES_LOG("Netplay players are flipped!\n");
msg_queue_push(g_extern.msg_queue, "Netplay players are flipped!", 1, 180);
return netplay_cmd_ack(handle);
}
default:
SSNES_ERR("Unknown netplay command received!\n");
return netplay_cmd_nak(handle);
}
}
void netplay_flip_players(netplay_t *handle)
{
uint32_t flip_frame = handle->frame_count + 2 * UDP_FRAME_PACKETS;
uint32_t flip_frame_net = htonl(flip_frame);
const char *msg = NULL;
if (handle->spectate)
{
msg = "Cannot flip players in spectate mode!";
goto error;
}
if (handle->port == 0)
{
msg = "Cannot flip players if you're not the host!";
goto error;
}
// Make sure both clients are definitely synced up.
if (handle->frame_count < (handle->flip_frame + 2 * UDP_FRAME_PACKETS))
{
msg = "Cannot flip players yet! Wait a second or two before attempting flip.";
goto error;
}
if (netplay_send_cmd(handle, NETPLAY_CMD_FLIP_PLAYERS, &flip_frame_net, sizeof(flip_frame_net))
&& netplay_get_response(handle))
{
SSNES_LOG("Netplay players are flipped!\n");
msg_queue_push(g_extern.msg_queue, "Netplay players are flipped!", 1, 180);
// Queue up a flip well enough in the future.
handle->flip ^= true;
handle->flip_frame = flip_frame;
}
else
{
msg = "Failed to flip players!";
goto error;
}
return;
error:
SSNES_WARN("%s\n", msg);
msg_queue_push(g_extern.msg_queue, msg, 1, 180);
}
static bool netplay_flip_port(netplay_t *handle, bool port)
{
if (handle->flip_frame == 0)
return port;
size_t frame = handle->is_replay ? handle->tmp_frame_count : handle->frame_count;
return port ^ handle->flip ^ (frame < handle->flip_frame);
}
int16_t netplay_input_state(netplay_t *handle, bool port, unsigned device, unsigned index, unsigned id)
{
uint16_t input_state = 0;
size_t ptr = handle->is_replay ? handle->tmp_ptr : PREV_PTR(handle->self_ptr);
port = netplay_flip_port(handle, port);
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);
if (handle->spectate)
{
for (unsigned i = 0; i < MAX_SPECTATORS; i++)
if (handle->spectate_fds[i] >= 0)
close(handle->spectate_fds[i]);
free(handle->spectate_input);
}
else
{
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);
}
static const struct snes_callbacks* netplay_callbacks(netplay_t *handle)
{
return &handle->cbs;
}
static bool netplay_should_skip(netplay_t *handle)
{
return handle->is_replay && handle->has_connection;
}
static void netplay_pre_frame_net(netplay_t *handle)
{
psnes_serialize(handle->buffer[handle->self_ptr].state, handle->state_size);
handle->can_poll = true;
input_poll_net();
}
static inline uint16_t swap_if_big16(uint16_t input)
{
if (is_little_endian())
return input;
else
return (input << 8) | (input >> 8);
}
static void netplay_set_spectate_input(netplay_t *handle, int16_t input)
{
if (handle->spectate_input_ptr >= handle->spectate_input_size)
{
handle->spectate_input_size++;
handle->spectate_input_size *= 2;
handle->spectate_input = (uint16_t*)realloc(handle->spectate_input,
handle->spectate_input_size * sizeof(uint16_t));
}
handle->spectate_input[handle->spectate_input_ptr++] = swap_if_big16(input);
}
int16_t input_state_spectate(bool port, unsigned device, unsigned index, unsigned id)
{
int16_t res = netplay_callbacks(g_extern.netplay)->state_cb(port, device, index, id);
netplay_set_spectate_input(g_extern.netplay, res);
return res;
}
static int16_t netplay_get_spectate_input(netplay_t *handle, bool port, unsigned device, unsigned index, unsigned id)
{
int16_t inp;
if (recv_all(handle->fd, NONCONST_CAST &inp, sizeof(inp)))
return swap_if_big16(inp);
else
{
SSNES_ERR("Connection with host was cut!\n");
msg_queue_clear(g_extern.msg_queue);
msg_queue_push(g_extern.msg_queue, "Connection with host was cut!", 1, 180);
psnes_set_input_state(netplay_callbacks(g_extern.netplay)->state_cb);
return netplay_callbacks(g_extern.netplay)->state_cb(port, device, index, id);
}
}
int16_t input_state_spectate_client(bool port, unsigned device, unsigned index, unsigned id)
{
return netplay_get_spectate_input(g_extern.netplay, port, device, index, id);
}
static void netplay_pre_frame_spectate(netplay_t *handle)
{
if (handle->spectate_client)
return;
fd_set fds;
FD_ZERO(&fds);
FD_SET(handle->fd, &fds);
struct timeval tmp_tv = {0};
if (select(handle->fd + 1, &fds, NULL, NULL, &tmp_tv) <= 0)
return;
if (!FD_ISSET(handle->fd, &fds))
return;
struct sockaddr_storage their_addr;
socklen_t addr_size = sizeof(their_addr);
int new_fd = accept(handle->fd, (struct sockaddr*)&their_addr, &addr_size);
if (new_fd < 0)
{
SSNES_ERR("Failed to accept incoming spectator!\n");
return;
}
int index = -1;
for (unsigned i = 0; i < MAX_SPECTATORS; i++)
{
if (handle->spectate_fds[i] == -1)
{
index = i;
break;
}
}
// No vacant client streams :(
if (index == -1)
{
close(new_fd);
return;
}
if (!get_nickname(handle, new_fd))
{
SSNES_ERR("Failed to get nickname from client!\n");
close(new_fd);
return;
}
if (!send_nickname(handle, new_fd))
{
SSNES_ERR("Failed to send nickname to client!\n");
close(new_fd);
return;
}
size_t header_size;
uint32_t *header = bsv_header_generate(&header_size, implementation_magic_value());
if (!header)
{
SSNES_ERR("Failed to generate BSV header!\n");
close(new_fd);
return;
}
int bufsize = header_size;
setsockopt(new_fd, SOL_SOCKET, SO_SNDBUF, CONST_CAST &bufsize, sizeof(int));
if (!send_all(new_fd, header, header_size))
{
SSNES_ERR("Failed to send header to client!\n");
close(new_fd);
free(header);
return;
}
free(header);
handle->spectate_fds[index] = new_fd;
#ifndef HAVE_SOCKET_LEGACY
log_connection(&their_addr, index, handle->other_nick);
#endif
}
void netplay_pre_frame(netplay_t *handle)
{
if (handle->spectate)
netplay_pre_frame_spectate(handle);
else
netplay_pre_frame_net(handle);
}
static void netplay_post_frame_net(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)
{
const 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;
handle->tmp_frame_count = handle->other_frame_count;
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);
handle->tmp_frame_count++;
first = false;
}
handle->other_ptr = handle->read_ptr;
handle->other_frame_count = handle->read_frame_count;
handle->is_replay = false;
}
}
static void netplay_post_frame_spectate(netplay_t *handle)
{
if (handle->spectate_client)
return;
for (unsigned i = 0; i < MAX_SPECTATORS; i++)
{
if (handle->spectate_fds[i] == -1)
continue;
if (!send_all(handle->spectate_fds[i],
handle->spectate_input, handle->spectate_input_ptr * sizeof(int16_t)))
{
SSNES_LOG("Client (#%u) disconnected ...\n", i);
char msg[512];
snprintf(msg, sizeof(msg), "Client (#%u) disconnected!", i);
msg_queue_push(g_extern.msg_queue, msg, 1, 180);
close(handle->spectate_fds[i]);
handle->spectate_fds[i] = -1;
break;
}
}
handle->spectate_input_ptr = 0;
}
// Here we check if we have new input and replay from recorded input.
void netplay_post_frame(netplay_t *handle)
{
if (handle->spectate)
netplay_post_frame_spectate(handle);
else
netplay_post_frame_net(handle);
}