easywsclient
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Published
20 hours ago •
dhbaird
dhbaird
enhancement: VC++ and MinGW ports
Easywsclient works in Linux at the moment. Let's get it working in Windows and Winsock, too.
I made modifications so that Easywsclient worked in Windows and Winsock. However, the operation check is insufficient. https://github.com/kivatek/easywsclient
@kivatek - First of all, thank you for your contribution. A few comments for your code:
(1) Can you fold this into the mainline code files (rather than as separate VS files) and use #if statements to choose Winsock-specific stuff? (rather than have completely separate files for MSVC) e.g., starting with something like this:
// See: Creating a Basic Winsock Application
// http://msdn.microsoft.com/en-us/library/windows/desktop/ms737629(v=vs.85).aspx
#ifdef _WIN32 // Windows
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <winsock2.h>
#include <ws2tcpip.h>
#pragma comment(lib, "Ws2_32.lib")
#else // Linux et al.
#include <sys/socket.h>
#include <netdb.h>
#endif
(2) A Winsock socket returns SOCKET (which is unsigned). Linux socket returns int. On error, a Linux socket returns -1, whereas Winsock returns INVALID_SOCKET (which is not a -1). So, there will need to be some more conditionals sprinkled around for these cases. The key here is to try to handle all of these cases, but also still keep the code as minimal as possible. Here are some good resources about Winsock:
- http://stackoverflow.com/questions/829625/winsock-2-portability (not sure this is complete or 100% accurate, so double check anything you read here)
- MSDN socket function
(3) Just for a heads up - when it comes time to merge, I'll be looking for a squashed patch (with intermediate edits removed). This is common practice on Github and plenty of documentation about how to do this exists.
If you do continue working on this, I'll be more than happy to work with you until we can get a final patch merged.
@kivatek - very good work, this looks great. Can you merge your work into the mainline code? I.e., vs2008/easywsclient.cpp -> easywsclient.cpp, vs2008/easywsclient.hpp -> easywsclient.hpp, et al. Then squash the commits into another branch (use git rebase) and send a pull request. If you need help with squash or pull request, let me know.
I get a bunch of "snprint_s" not found when I try to compile with MinGW on Windows. If I comment out those lines it compiles fine I get a memory read exception (code is nothing other than a basic client that sends hello and has winsock in the linker). The same source and files work fine in my Linux environment. Any ideas?
I was able to resolve all issues, for the snprint_s problem for some reason the ifndef wasn't detecting that it was defined and then I had to call WSAStartup to initialize winsock before the socket was requested. All in all I can compile and exchange data with these bits added:
#if !defined(snprintf) && !defined(__MINGW32__)
#define snprintf _snprintf_s
#endif
#if _MSC_VER >=1600 || defined(__MINGW32__)
// vs2010 or later
#include <stdint.h>
#else
and
#ifdef _WIN32
WSADATA WSAData;
if ((ret = WSAStartup(MAKEWORD(2, 2), &WSAData)) != 0)
{
fprintf(stderr, "WSAStartup: %s\n", gai_strerror(ret));
return 1;
}
#endif
Here it is all together:
#ifdef _WIN32
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS // _CRT_SECURE_NO_WARNINGS for sscanf errors in MSVC2013 Express
#endif
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <fcntl.h>
#include <WinSock2.h>
#include <WS2tcpip.h>
#pragma comment( lib, "ws2_32" )
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <io.h>
#ifndef _SSIZE_T_DEFINED
typedef int ssize_t;
#define _SSIZE_T_DEFINED
#endif
#ifndef _SOCKET_T_DEFINED
typedef SOCKET socket_t;
#define _SOCKET_T_DEFINED
#endif
#if !defined(snprintf) && !defined(__MINGW32__)
#define snprintf _snprintf_s
#endif
#if _MSC_VER >=1600 || defined(__MINGW32__)
// vs2010 or later
#include <stdint.h>
#else
typedef __int8 int8_t;
typedef unsigned __int8 uint8_t;
typedef __int32 int32_t;
typedef unsigned __int32 uint32_t;
typedef __int64 int64_t;
typedef unsigned __int64 uint64_t;
#endif
#define socketerrno WSAGetLastError()
#define SOCKET_EAGAIN_EINPROGRESS WSAEINPROGRESS
#define SOCKET_EWOULDBLOCK WSAEWOULDBLOCK
#else
#include <fcntl.h>
#include <netdb.h>
#include <netinet/tcp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdint.h>
#ifndef _SOCKET_T_DEFINED
typedef int socket_t;
#define _SOCKET_T_DEFINED
#endif
#ifndef INVALID_SOCKET
#define INVALID_SOCKET (-1)
#endif
#ifndef SOCKET_ERROR
#define SOCKET_ERROR (-1)
#endif
#define closesocket(s) ::close(s)
#include <errno.h>
#define socketerrno errno
#define SOCKET_EAGAIN_EINPROGRESS EAGAIN
#define SOCKET_EWOULDBLOCK EWOULDBLOCK
#endif
#include <vector>
#include <string>
#include "easywsclient.hpp"
using easywsclient::Callback_Imp;
using easywsclient::BytesCallback_Imp;
namespace { // private module-only namespace
socket_t hostname_connect(const std::string& hostname, int port) {
struct addrinfo hints;
struct addrinfo *result;
struct addrinfo *p;
int ret;
socket_t sockfd = INVALID_SOCKET;
char sport[16];
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
snprintf(sport, 16, "%d", port);
#ifdef _WIN32
WSADATA WSAData;
if ((ret = WSAStartup(MAKEWORD(2, 2), &WSAData)) != 0)
{
fprintf(stderr, "WSAStartup: %s\n", gai_strerror(ret));
return 1;
}
#endif
if ((ret = getaddrinfo(hostname.c_str(), sport, &hints, &result)) != 0)
{
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(ret));
return 1;
}
for(p = result; p != NULL; p = p->ai_next)
{
sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
if (sockfd == INVALID_SOCKET) { continue; }
if (connect(sockfd, p->ai_addr, p->ai_addrlen) != SOCKET_ERROR) {
break;
}
closesocket(sockfd);
sockfd = INVALID_SOCKET;
}
freeaddrinfo(result);
return sockfd;
}
class _DummyWebSocket : public easywsclient::WebSocket
{
public:
void poll(int timeout) { }
void send(const std::string& message) { }
void sendBinary(const std::string& message) { }
void sendBinary(const std::vector<uint8_t>& message) { }
void sendPing() { }
void close() { }
readyStateValues getReadyState() const { return CLOSED; }
void _dispatch(Callback_Imp & callable) { }
void _dispatchBinary(BytesCallback_Imp& callable) { }
};
class _RealWebSocket : public easywsclient::WebSocket
{
public:
// http://tools.ietf.org/html/rfc6455#section-5.2 Base Framing Protocol
//
// 0 1 2 3
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
// +-+-+-+-+-------+-+-------------+-------------------------------+
// |F|R|R|R| opcode|M| Payload len | Extended payload length |
// |I|S|S|S| (4) |A| (7) | (16/64) |
// |N|V|V|V| |S| | (if payload len==126/127) |
// | |1|2|3| |K| | |
// +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - +
// | Extended payload length continued, if payload len == 127 |
// + - - - - - - - - - - - - - - - +-------------------------------+
// | |Masking-key, if MASK set to 1 |
// +-------------------------------+-------------------------------+
// | Masking-key (continued) | Payload Data |
// +-------------------------------- - - - - - - - - - - - - - - - +
// : Payload Data continued ... :
// + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
// | Payload Data continued ... |
// +---------------------------------------------------------------+
struct wsheader_type {
unsigned header_size;
bool fin;
bool mask;
enum opcode_type {
CONTINUATION = 0x0,
TEXT_FRAME = 0x1,
BINARY_FRAME = 0x2,
CLOSE = 8,
PING = 9,
PONG = 0xa,
} opcode;
int N0;
uint64_t N;
uint8_t masking_key[4];
};
std::vector<uint8_t> rxbuf;
std::vector<uint8_t> txbuf;
std::vector<uint8_t> receivedData;
socket_t sockfd;
readyStateValues readyState;
bool useMask;
_RealWebSocket(socket_t sockfd, bool useMask) : sockfd(sockfd), readyState(OPEN), useMask(useMask) {
}
readyStateValues getReadyState() const {
return readyState;
}
void poll(int timeout) { // timeout in milliseconds
if (readyState == CLOSED) {
if (timeout > 0) {
timeval tv = { timeout/1000, (timeout%1000) * 1000 };
select(0, NULL, NULL, NULL, &tv);
}
return;
}
if (timeout > 0) {
fd_set rfds;
fd_set wfds;
timeval tv = { timeout/1000, (timeout%1000) * 1000 };
FD_ZERO(&rfds);
FD_ZERO(&wfds);
FD_SET(sockfd, &rfds);
if (txbuf.size()) { FD_SET(sockfd, &wfds); }
select(sockfd + 1, &rfds, &wfds, NULL, &tv);
}
while (true) {
// FD_ISSET(0, &rfds) will be true
int N = rxbuf.size();
ssize_t ret;
rxbuf.resize(N + 1500);
ret = recv(sockfd, (char*)&rxbuf[0] + N, 1500, 0);
if (false) { }
else if (ret < 0 && (socketerrno == SOCKET_EWOULDBLOCK || socketerrno == SOCKET_EAGAIN_EINPROGRESS)) {
rxbuf.resize(N);
break;
}
else if (ret <= 0) {
rxbuf.resize(N);
closesocket(sockfd);
readyState = CLOSED;
fputs(ret < 0 ? "Connection error!\n" : "Connection closed!\n", stderr);
break;
}
else {
rxbuf.resize(N + ret);
}
}
while (txbuf.size()) {
int ret = ::send(sockfd, (char*)&txbuf[0], txbuf.size(), 0);
if (false) { } // ??
else if (ret < 0 && (socketerrno == SOCKET_EWOULDBLOCK || socketerrno == SOCKET_EAGAIN_EINPROGRESS)) {
break;
}
else if (ret <= 0) {
closesocket(sockfd);
readyState = CLOSED;
fputs(ret < 0 ? "Connection error!\n" : "Connection closed!\n", stderr);
break;
}
else {
txbuf.erase(txbuf.begin(), txbuf.begin() + ret);
}
}
if (!txbuf.size() && readyState == CLOSING) {
closesocket(sockfd);
readyState = CLOSED;
}
}
// Callable must have signature: void(const std::string & message).
// Should work with C functions, C++ functors, and C++11 std::function and
// lambda:
//template<class Callable>
//void dispatch(Callable callable)
virtual void _dispatch(Callback_Imp & callable) {
struct CallbackAdapter : public BytesCallback_Imp
// Adapt void(const std::string<uint8_t>&) to void(const std::string&)
{
Callback_Imp& callable;
CallbackAdapter(Callback_Imp& callable) : callable(callable) { }
void operator()(const std::vector<uint8_t>& message) {
std::string stringMessage(message.begin(), message.end());
callable(stringMessage);
}
};
CallbackAdapter bytesCallback(callable);
_dispatchBinary(bytesCallback);
}
virtual void _dispatchBinary(BytesCallback_Imp & callable) {
// TODO: consider acquiring a lock on rxbuf...
while (true) {
wsheader_type ws;
if (rxbuf.size() < 2) { return; /* Need at least 2 */ }
const uint8_t * data = (uint8_t *) &rxbuf[0]; // peek, but don't consume
ws.fin = (data[0] & 0x80) == 0x80;
ws.opcode = (wsheader_type::opcode_type) (data[0] & 0x0f);
ws.mask = (data[1] & 0x80) == 0x80;
ws.N0 = (data[1] & 0x7f);
ws.header_size = 2 + (ws.N0 == 126? 2 : 0) + (ws.N0 == 127? 8 : 0) + (ws.mask? 4 : 0);
if (rxbuf.size() < ws.header_size) { return; /* Need: ws.header_size - rxbuf.size() */ }
int i = 0;
if (ws.N0 < 126) {
ws.N = ws.N0;
i = 2;
}
else if (ws.N0 == 126) {
ws.N = 0;
ws.N |= ((uint64_t) data[2]) << 8;
ws.N |= ((uint64_t) data[3]) << 0;
i = 4;
}
else if (ws.N0 == 127) {
ws.N = 0;
ws.N |= ((uint64_t) data[2]) << 56;
ws.N |= ((uint64_t) data[3]) << 48;
ws.N |= ((uint64_t) data[4]) << 40;
ws.N |= ((uint64_t) data[5]) << 32;
ws.N |= ((uint64_t) data[6]) << 24;
ws.N |= ((uint64_t) data[7]) << 16;
ws.N |= ((uint64_t) data[8]) << 8;
ws.N |= ((uint64_t) data[9]) << 0;
i = 10;
}
if (ws.mask) {
ws.masking_key[0] = ((uint8_t) data[i+0]) << 0;
ws.masking_key[1] = ((uint8_t) data[i+1]) << 0;
ws.masking_key[2] = ((uint8_t) data[i+2]) << 0;
ws.masking_key[3] = ((uint8_t) data[i+3]) << 0;
}
else {
ws.masking_key[0] = 0;
ws.masking_key[1] = 0;
ws.masking_key[2] = 0;
ws.masking_key[3] = 0;
}
if (rxbuf.size() < ws.header_size+ws.N) { return; /* Need: ws.header_size+ws.N - rxbuf.size() */ }
// We got a whole message, now do something with it:
if (false) { }
else if (
ws.opcode == wsheader_type::TEXT_FRAME
|| ws.opcode == wsheader_type::BINARY_FRAME
|| ws.opcode == wsheader_type::CONTINUATION
) {
if (ws.mask) { for (size_t i = 0; i != ws.N; ++i) { rxbuf[i+ws.header_size] ^= ws.masking_key[i&0x3]; } }
receivedData.insert(receivedData.end(), rxbuf.begin()+ws.header_size, rxbuf.begin()+ws.header_size+(size_t)ws.N);// just feed
if (ws.fin) {
callable((const std::vector<uint8_t>) receivedData);
receivedData.erase(receivedData.begin(), receivedData.end());
std::vector<uint8_t> ().swap(receivedData);// free memory
}
}
else if (ws.opcode == wsheader_type::PING) {
if (ws.mask) { for (size_t i = 0; i != ws.N; ++i) { rxbuf[i+ws.header_size] ^= ws.masking_key[i&0x3]; } }
std::string data(rxbuf.begin()+ws.header_size, rxbuf.begin()+ws.header_size+(size_t)ws.N);
sendData(wsheader_type::PONG, data.size(), data.begin(), data.end());
}
else if (ws.opcode == wsheader_type::PONG) { }
else if (ws.opcode == wsheader_type::CLOSE) { close(); }
else { fprintf(stderr, "ERROR: Got unexpected WebSocket message.\n"); close(); }
rxbuf.erase(rxbuf.begin(), rxbuf.begin() + ws.header_size+(size_t)ws.N);
}
}
void sendPing() {
std::string empty;
sendData(wsheader_type::PING, empty.size(), empty.begin(), empty.end());
}
void send(const std::string& message) {
sendData(wsheader_type::TEXT_FRAME, message.size(), message.begin(), message.end());
}
void sendBinary(const std::string& message) {
sendData(wsheader_type::BINARY_FRAME, message.size(), message.begin(), message.end());
}
void sendBinary(const std::vector<uint8_t>& message) {
sendData(wsheader_type::BINARY_FRAME, message.size(), message.begin(), message.end());
}
template<class Iterator>
void sendData(wsheader_type::opcode_type type, uint64_t message_size, Iterator message_begin, Iterator message_end) {
// TODO:
// Masking key should (must) be derived from a high quality random
// number generator, to mitigate attacks on non-WebSocket friendly
// middleware:
const uint8_t masking_key[4] = { 0x12, 0x34, 0x56, 0x78 };
// TODO: consider acquiring a lock on txbuf...
if (readyState == CLOSING || readyState == CLOSED) { return; }
std::vector<uint8_t> header;
header.assign(2 + (message_size >= 126 ? 2 : 0) + (message_size >= 65536 ? 6 : 0) + (useMask ? 4 : 0), 0);
header[0] = 0x80 | type;
if (false) { }
else if (message_size < 126) {
header[1] = (message_size & 0xff) | (useMask ? 0x80 : 0);
if (useMask) {
header[2] = masking_key[0];
header[3] = masking_key[1];
header[4] = masking_key[2];
header[5] = masking_key[3];
}
}
else if (message_size < 65536) {
header[1] = 126 | (useMask ? 0x80 : 0);
header[2] = (message_size >> 8) & 0xff;
header[3] = (message_size >> 0) & 0xff;
if (useMask) {
header[4] = masking_key[0];
header[5] = masking_key[1];
header[6] = masking_key[2];
header[7] = masking_key[3];
}
}
else { // TODO: run coverage testing here
header[1] = 127 | (useMask ? 0x80 : 0);
header[2] = (message_size >> 56) & 0xff;
header[3] = (message_size >> 48) & 0xff;
header[4] = (message_size >> 40) & 0xff;
header[5] = (message_size >> 32) & 0xff;
header[6] = (message_size >> 24) & 0xff;
header[7] = (message_size >> 16) & 0xff;
header[8] = (message_size >> 8) & 0xff;
header[9] = (message_size >> 0) & 0xff;
if (useMask) {
header[10] = masking_key[0];
header[11] = masking_key[1];
header[12] = masking_key[2];
header[13] = masking_key[3];
}
}
// N.B. - txbuf will keep growing until it can be transmitted over the socket:
txbuf.insert(txbuf.end(), header.begin(), header.end());
txbuf.insert(txbuf.end(), message_begin, message_end);
if (useMask) {
for (size_t i = 0; i != message_size; ++i) { *(txbuf.end() - message_size + i) ^= masking_key[i&0x3]; }
}
}
void close() {
if(readyState == CLOSING || readyState == CLOSED) { return; }
readyState = CLOSING;
uint8_t closeFrame[6] = {0x88, 0x80, 0x00, 0x00, 0x00, 0x00}; // last 4 bytes are a masking key
std::vector<uint8_t> header(closeFrame, closeFrame+6);
txbuf.insert(txbuf.end(), header.begin(), header.end());
}
};
easywsclient::WebSocket::pointer from_url(const std::string& url, bool useMask, const std::string& origin) {
char host[128];
int port;
char path[128];
if (url.size() >= 128) {
fprintf(stderr, "ERROR: url size limit exceeded: %s\n", url.c_str());
return NULL;
}
if (origin.size() >= 200) {
fprintf(stderr, "ERROR: origin size limit exceeded: %s\n", origin.c_str());
return NULL;
}
if (false) { }
else if (sscanf(url.c_str(), "ws://%[^:/]:%d/%s", host, &port, path) == 3) {
}
else if (sscanf(url.c_str(), "ws://%[^:/]/%s", host, path) == 2) {
port = 80;
}
else if (sscanf(url.c_str(), "ws://%[^:/]:%d", host, &port) == 2) {
path[0] = '\0';
}
else if (sscanf(url.c_str(), "ws://%[^:/]", host) == 1) {
port = 80;
path[0] = '\0';
}
else {
fprintf(stderr, "ERROR: Could not parse WebSocket url: %s\n", url.c_str());
return NULL;
}
fprintf(stderr, "easywsclient: connecting: host=%s port=%d path=/%s\n", host, port, path);
socket_t sockfd = hostname_connect(host, port);
if (sockfd == INVALID_SOCKET) {
fprintf(stderr, "Unable to connect to %s:%d\n", host, port);
return NULL;
}
{
// XXX: this should be done non-blocking,
char line[256];
int status;
int i;
snprintf(line, 256, "GET /%s HTTP/1.1\r\n", path); ::send(sockfd, line, strlen(line), 0);
if (port == 80) {
snprintf(line, 256, "Host: %s\r\n", host); ::send(sockfd, line, strlen(line), 0);
}
else {
snprintf(line, 256, "Host: %s:%d\r\n", host, port); ::send(sockfd, line, strlen(line), 0);
}
snprintf(line, 256, "Upgrade: websocket\r\n"); ::send(sockfd, line, strlen(line), 0);
snprintf(line, 256, "Connection: Upgrade\r\n"); ::send(sockfd, line, strlen(line), 0);
if (!origin.empty()) {
snprintf(line, 256, "Origin: %s\r\n", origin.c_str()); ::send(sockfd, line, strlen(line), 0);
}
snprintf(line, 256, "Sec-WebSocket-Key: x3JJHMbDL1EzLkh9GBhXDw==\r\n"); ::send(sockfd, line, strlen(line), 0);
snprintf(line, 256, "Sec-WebSocket-Version: 13\r\n"); ::send(sockfd, line, strlen(line), 0);
snprintf(line, 256, "\r\n"); ::send(sockfd, line, strlen(line), 0);
for (i = 0; i < 2 || (i < 255 && line[i-2] != '\r' && line[i-1] != '\n'); ++i) { if (recv(sockfd, line+i, 1, 0) == 0) { return NULL; } }
line[i] = 0;
if (i == 255) { fprintf(stderr, "ERROR: Got invalid status line connecting to: %s\n", url.c_str()); return NULL; }
if (sscanf(line, "HTTP/1.1 %d", &status) != 1 || status != 101) { fprintf(stderr, "ERROR: Got bad status connecting to %s: %s", url.c_str(), line); return NULL; }
// TODO: verify response headers,
while (true) {
for (i = 0; i < 2 || (i < 255 && line[i-2] != '\r' && line[i-1] != '\n'); ++i) { if (recv(sockfd, line+i, 1, 0) == 0) { return NULL; } }
if (line[0] == '\r' && line[1] == '\n') { break; }
}
}
int flag = 1;
setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, (char*) &flag, sizeof(flag)); // Disable Nagle's algorithm
#ifdef _WIN32
u_long on = 1;
ioctlsocket(sockfd, FIONBIO, &on);
#else
fcntl(sockfd, F_SETFL, O_NONBLOCK);
#endif
fprintf(stderr, "Connected to: %s\n", url.c_str());
return easywsclient::WebSocket::pointer(new _RealWebSocket(sockfd, useMask));
}
} // end of module-only namespace
namespace easywsclient {
WebSocket::pointer WebSocket::create_dummy() {
static pointer dummy = pointer(new _DummyWebSocket);
return dummy;
}
WebSocket::pointer WebSocket::from_url(const std::string& url, const std::string& origin) {
return ::from_url(url, true, origin);
}
WebSocket::pointer WebSocket::from_url_no_mask(const std::string& url, const std::string& origin) {
return ::from_url(url, false, origin);
}
} // namespace easywsclient
Hey @zamadatix if you are still out there, please know - you just helped me a lot with this example. <3
