ddnet/src/engine/shared/websockets.cpp
2022-03-21 16:28:25 -03:00

309 lines
7.2 KiB
C++

#if defined(CONF_WEBSOCKETS)
#include <map>
#include <stdlib.h>
#include <string>
#include "base/system.h"
#include "protocol.h"
#include "ringbuffer.h"
#if defined(CONF_FAMILY_UNIX)
#include <arpa/inet.h>
#elif defined(CONF_FAMILY_WINDOWS)
#include <ws2tcpip.h>
#endif
#include <libwebsockets.h>
#include "websockets.h"
// not sure why would anyone need more than one but well...
#define WS_CONTEXTS 4
// ddnet client opens two connections for whatever reason
#define WS_CLIENTS (MAX_CLIENTS * 2)
typedef CStaticRingBuffer<unsigned char, WS_CLIENTS * 4 * 1024,
CRingBufferBase::FLAG_RECYCLE>
TRecvBuffer;
typedef CStaticRingBuffer<unsigned char, 4 * 1024,
CRingBufferBase::FLAG_RECYCLE>
TSendBuffer;
typedef struct
{
size_t size;
size_t read;
sockaddr_in addr;
unsigned char data[0];
} websocket_chunk;
struct per_session_data
{
struct lws *wsi;
std::string addr_str;
sockaddr_in addr;
TSendBuffer send_buffer;
};
struct context_data
{
lws_context *context;
std::map<std::string, per_session_data *> port_map;
TRecvBuffer recv_buffer;
};
static int receive_chunk(context_data *ctx_data, struct per_session_data *pss,
void *in, size_t len)
{
websocket_chunk *chunk = (websocket_chunk *)ctx_data->recv_buffer.Allocate(
len + sizeof(websocket_chunk));
if(chunk == 0)
return 1;
chunk->size = len;
chunk->read = 0;
memcpy(&chunk->addr, &pss->addr, sizeof(sockaddr_in));
memcpy(&chunk->data[0], in, len);
return 0;
}
static int websocket_callback(struct lws *wsi, enum lws_callback_reasons reason,
void *user, void *in, size_t len)
{
struct per_session_data *pss = (struct per_session_data *)user;
lws_context *context = lws_get_context(wsi);
context_data *ctx_data = (context_data *)lws_context_user(context);
switch(reason)
{
case LWS_CALLBACK_WSI_CREATE:
if(pss == NULL)
{
return 0;
}
/* FALLTHRU */
case LWS_CALLBACK_ESTABLISHED:
{
pss->wsi = wsi;
int fd = lws_get_socket_fd(wsi);
socklen_t addr_size = sizeof(pss->addr);
getpeername(fd, (struct sockaddr *)&pss->addr, &addr_size);
int orig_port = ntohs(pss->addr.sin_port);
pss->send_buffer.Init();
char addr_str[NETADDR_MAXSTRSIZE];
int ip_uint32 = pss->addr.sin_addr.s_addr;
str_format(addr_str, sizeof(addr_str), "%d.%d.%d.%d:%d", (ip_uint32)&0xff, (ip_uint32 >> 8) & 0xff, (ip_uint32 >> 16) & 0xff, (ip_uint32 >> 24) & 0xff, orig_port);
dbg_msg("websockets", "connection established with %s", addr_str);
pss->addr_str = addr_str;
ctx_data->port_map[pss->addr_str] = pss;
}
break;
case LWS_CALLBACK_CLOSED:
{
dbg_msg("websockets", "connection with addr string %s closed", pss->addr_str.c_str());
if(!pss->addr_str.empty())
{
unsigned char close_packet[] = {0x10, 0x0e, 0x00, 0x04};
receive_chunk(ctx_data, pss, &close_packet, sizeof(close_packet));
pss->wsi = 0;
ctx_data->port_map.erase(pss->addr_str);
}
}
break;
case LWS_CALLBACK_CLIENT_WRITEABLE:
/* FALLTHRU */
case LWS_CALLBACK_SERVER_WRITEABLE:
{
websocket_chunk *chunk = (websocket_chunk *)pss->send_buffer.First();
if(chunk == NULL)
break;
int chunk_len = chunk->size - chunk->read;
int n =
lws_write(wsi, &chunk->data[LWS_SEND_BUFFER_PRE_PADDING + chunk->read],
chunk->size - chunk->read, LWS_WRITE_BINARY);
if(n < 0)
return 1;
if(n < chunk_len)
{
chunk->read += n;
lws_callback_on_writable(wsi);
break;
}
pss->send_buffer.PopFirst();
lws_callback_on_writable(wsi);
}
break;
case LWS_CALLBACK_CLIENT_RECEIVE:
/* FALLTHRU */
case LWS_CALLBACK_RECEIVE:
if(pss->addr_str.empty())
return -1;
if(receive_chunk(ctx_data, pss, in, len))
return 1;
break;
default:
break;
}
return 0;
}
static struct lws_protocols protocols[] = {
{
"binary", /* name */
websocket_callback, /* callback */
sizeof(struct per_session_data) /* per_session_data_size */
},
{
NULL, NULL, 0 /* End of list */
}};
static context_data contexts[WS_CONTEXTS];
int websocket_create(const char *addr, int port)
{
struct lws_context_creation_info info;
memset(&info, 0, sizeof(info));
info.port = port;
info.iface = addr;
info.protocols = protocols;
info.gid = -1;
info.uid = -1;
// find free context
int first_free = -1;
for(int i = 0; i < WS_CONTEXTS; i++)
{
if(contexts[i].context == NULL)
{
first_free = i;
break;
}
}
if(first_free == -1)
return -1;
context_data *ctx_data = &contexts[first_free];
info.user = (void *)ctx_data;
ctx_data->context = lws_create_context(&info);
if(ctx_data->context == NULL)
{
return -1;
}
ctx_data->recv_buffer.Init();
return first_free;
}
int websocket_destroy(int socket)
{
lws_context *context = contexts[socket].context;
if(context == NULL)
return -1;
lws_context_destroy(context);
contexts[socket].context = NULL;
return 0;
}
int websocket_recv(int socket, unsigned char *data, size_t maxsize,
struct sockaddr_in *sockaddrbuf, size_t fromLen)
{
lws_context *context = contexts[socket].context;
if(context == NULL)
return -1;
int n = lws_service(context, -1);
if(n < 0)
return n;
context_data *ctx_data = (context_data *)lws_context_user(context);
websocket_chunk *chunk = (websocket_chunk *)ctx_data->recv_buffer.First();
if(chunk == 0)
return 0;
if(maxsize >= chunk->size - chunk->read)
{
int len = chunk->size - chunk->read;
memcpy(data, &chunk->data[chunk->read], len);
memcpy(sockaddrbuf, &chunk->addr, fromLen);
ctx_data->recv_buffer.PopFirst();
return len;
}
else
{
memcpy(data, &chunk->data[chunk->read], maxsize);
memcpy(sockaddrbuf, &chunk->addr, fromLen);
chunk->read += maxsize;
return maxsize;
}
}
int websocket_send(int socket, const unsigned char *data, size_t size,
const char *addr_str, int port)
{
lws_context *context = contexts[socket].context;
if(context == NULL)
{
return -1;
}
context_data *ctx_data = (context_data *)lws_context_user(context);
char buf[100];
snprintf(buf, sizeof(buf), "%s:%d", addr_str, port);
std::string addr_str_with_port = std::string(buf);
struct per_session_data *pss = ctx_data->port_map[addr_str_with_port];
if(pss == NULL)
{
struct lws_client_connect_info ccinfo = {0};
ccinfo.context = context;
ccinfo.address = addr_str;
ccinfo.port = port;
ccinfo.protocol = protocols[0].name;
lws *wsi = lws_client_connect_via_info(&ccinfo);
if(wsi == NULL)
{
return -1;
}
lws_service(context, -1);
pss = ctx_data->port_map[addr_str_with_port];
if(pss == NULL)
{
return -1;
}
}
websocket_chunk *chunk = (websocket_chunk *)pss->send_buffer.Allocate(
size + sizeof(websocket_chunk) + LWS_SEND_BUFFER_PRE_PADDING +
LWS_SEND_BUFFER_POST_PADDING);
if(chunk == NULL)
return -1;
chunk->size = size;
chunk->read = 0;
memcpy(&chunk->addr, &pss->addr, sizeof(sockaddr_in));
memcpy(&chunk->data[LWS_SEND_BUFFER_PRE_PADDING], data, size);
lws_callback_on_writable(pss->wsi);
lws_service(context, -1);
return size;
}
int websocket_fd_set(int socket, fd_set *set)
{
lws_context *context = contexts[socket].context;
if(context == NULL)
return -1;
lws_service(context, -1);
context_data *ctx_data = (context_data *)lws_context_user(context);
int max = 0;
for(auto const &x : ctx_data->port_map)
{
if(x.second == NULL)
continue;
int fd = lws_get_socket_fd(x.second->wsi);
if(fd > max)
max = fd;
FD_SET(fd, set);
}
return max;
}
#endif