This adds a complete useful capi with ssl suport and most examples added.

It's a step to solve this issue: https://github.com/uNetworking/uWebSockets/issues/1192 Opaque C interface for Swift, Rust, etc

For now its just a wrapper and can be optimized a lot, but its a start.

make capi, and make capi_examples for build added

I am running into a situation where the library has a seg fault while trying to publish on the websockets. During the call to publish(), the library calls into drain(), which calls the cb() function of TopicTree. While executing that function, the segfault occurs because the Subscriber pointer is reset to UINTPTR_MAX.

I could not cause this problem with a single client. The corner case is occurring when I have thousands of clients connected while publishing a large number of updates. As I end up overwhelming the clients, I see TCP retransmits and TCP windows reach 0. As the congestion occurs, some clients begin closing sockets. When this happens, TopicTree.h line 374 cb(min, intersectionCache[intersection] = std::move(res)); is eventually called with min set to UINTPTR_MAX. This then causes the seg fault in WebSocketContextData.h on line 61 auto *asyncSocket = (AsyncSocket<SSL> *) s->user; when trying to access the user.

I've made two changes to workaround this, but am not sure if this is the best or proper solution.

In WebSocketContextData.h, I added the if check on the subscriber pointer:

    WebSocketContextData() : topicTree([this](Subscriber *s, std::string_view data) -> int {
        /* We rely on writing to regular asyncSockets */
        if (s != (Subscriber *)UINTPTR_MAX) {
            auto *asyncSocket = (AsyncSocket<SSL> *) s->user;

And in TopicTree.h in the drain() method around line 350, I added the additional code to decrement nonEmpty.

                    else {
                        /* We need to lower nextMin to us, in the case of min being the last in a set */
                        if ((it[i] != end[i]) && (nextMin > *it[i])) {
                            nextMin = *it[i];
                        } else if (min == (Subscriber *)UINTPTR_MAX) {
                            if (nonEmpty > 0) {
                                nonEmpty--;
                            }
                        }
                    }

Also the backtrace from gdb.

(gdb) bt
#0  0x00007f847a010837 in ioctl () from /lib64/libc.so.6
#1  0x00007f847cb854bf in oo_resource_op (cmd=1074027035, io=0x7f84745ce65c, fp=<optimized out>) at ../../../../../src/include/onload/unix_intf.h:80
#2  citp_signal_terminate (signum=<optimized out>, info=<optimized out>, context=<optimized out>) at ../../../../../src/lib/transport/ip/signal.c:280
#3  0x00007f847cb85412 in citp_signal_run_app_handler ([email protected]=11, [email protected]=0x7f84745ce8f0, [email protected]=0x7f84745ce7c0) at ../../../../../src/lib/transport/ip/signal.c:106
#4  0x00007f847cb8565a in citp_signal_run_now (our_info=<optimized out>, context=0x7f84745ce7c0, info=0x7f84745ce8f0, signum=11) at ../../../../../src/lib/transport/ip/signal.c:226
#5  citp_signal_intercept (signum=11, info=0x7f84745ce8f0, context=0x7f84745ce7c0) at ../../../../../src/lib/transport/ip/signal.c:263
#6  <signal handler called>
#7  0x0000000000446f66 in std::_Function_handler<int (uWS::Subscriber*, std::basic_string_view<char, std::char_traits<char> >), uWS::WebSocketContextData<false>::WebSocketContextData()::{lambda(uWS::Subscriber*, std::basic_string_view<char, std::char_traits<char> >)#1}>::_M_invoke(std::_Any_data const&, uWS::Subscriber*&&, std::basic_string_view<char, std::char_traits<char> >&&) (__functor=...,
    __args#0=<optimized out>, __args#1=...) at /opt/x3p/xrt_b/base/lib/gcc/x86_64-unknown-linux/7/../../../../include/c++/7/bits/std_function.h:299
#8  0x00000000004277e8 in std::function<int (uWS::Subscriber*, std::basic_string_view<char, std::char_traits<char> >)>::operator()(uWS::Subscriber*, std::basic_string_view<char, std::char_traits<char> >) const (__args#1="", __args#0=<optimized out>, this=0x1f4cd48) at /opt/x3p/xrt_b/base/lib/gcc/x86_64-unknown-linux/7/../../../../include/c++/7/bits/std_function.h:706
#9  uWS::TopicTree::drain (this=0x1f4cd48) at bazel-out/k8-opt/bin/external/uWebSockets/_virtual_includes/uWebSockets/uWebSockets/TopicTree.h:374
#10 0x0000000000411bd7 in fu2::abi_400::detail::type_erasure::tables::vtable<fu2::abi_400::detail::property<true, false, void (uWS::Loop*)> >::invoke<0ul, fu2::abi_400::detail::type_erasure::data_accessor*, unsigned long const&, uWS::Loop*>(fu2::abi_400::detail::type_erasure::data_accessor*&&, unsigned long const&, uWS::Loop*&&) const (this=0x1ec7df0)
    at bazel-out/k8-opt/bin/external/uWebSockets/_virtual_includes/uWebSockets/uWebSockets/f2/function2.hpp:995
#11 fu2::abi_400::detail::type_erasure::erasure<true, fu2::abi_400::detail::config<true, false, fu2::capacity_default>, fu2::abi_400::detail::property<true, false, void (uWS::Loop*)> >::invoke<0ul, fu2::abi_400::detail::type_erasure::erasure<true, fu2::abi_400::detail::config<true, false, fu2::capacity_default>, fu2::abi_400::detail::property<true, false, void (uWS::Loop*)> >&, uWS::Loop*>(fu2::abi_400::detail::type_erasure::erasure<true, fu2::abi_400::detail::config<true, false, fu2::capacity_default>, fu2::abi_400::detail::property<true, false, void (uWS::Loop*)> >&, uWS::Loop*&&) (erasure=...)
    at bazel-out/k8-opt/bin/external/uWebSockets/_virtual_includes/uWebSockets/uWebSockets/f2/function2.hpp:1215
#12 fu2::abi_400::detail::type_erasure::invocation_table::operator_impl<0ul, fu2::abi_400::detail::function<fu2::abi_400::detail::config<true, false, fu2::capacity_default>, fu2::abi_400::detail::property<true, false, void (uWS::Loop*)> >, void (uWS::Loop*)>::operator()(uWS::Loop*) (args#0=0x384e000, this=0x1ec7de0)
    at bazel-out/k8-opt/bin/external/uWebSockets/_virtual_includes/uWebSockets/uWebSockets/f2/function2.hpp:775
#13 uWS::Loop::postCb (loop=0x384e000) at bazel-out/k8-opt/bin/external/uWebSockets/_virtual_includes/uWebSockets/uWebSockets/Loop.h:57
#14 0x0000000000706a88 in us_loop_run (loop=0x384e000) at external/uSockets/src/eventing/epoll_kqueue.c:149
#15 0x00000000004557e4 in uWS::Loop::run (this=<optimized out>) at bazel-out/k8-opt/bin/external/uWebSockets/_virtual_includes/uWebSockets/uWebSockets/Loop.h:152
#16 uWS::run () at bazel-out/k8-opt/bin/external/uWebSockets/_virtual_includes/uWebSockets/uWebSockets/Loop.h:164
#17 uWS::TemplatedApp<false>::run (this=<optimized out>) at bazel-out/k8-opt/bin/external/uWebSockets/_virtual_includes/uWebSockets/uWebSockets/App.h:334

All versions of uWS are totally incompatible with iOS 15 when using compression and will not keep a connection. This is because of an Apple bug where client_no_context_takeover is not properly implemented in newest Safari for iOS 15.

Because of this, if you use compression and expect iOS 15 connections, you will have to enable uWS::DEDICATED_DECOMPRESSOR as well.

See EchoServer.cpp example. uWS::DEDICATED_DECOMPRESSOR is available in v20.3.0 and forward. This adds about 44kb of memory usage per connection.

Is there any best practice for implementing websockets authorization with uWS? In previous versions of the library it was possible to check a bearer token in the req.headers of the initial HTTP request before upgrading to websockets, then respond with status 401 oer whatever. Is this still possible somehow? currently I am doing the authorization in the ws callback like this:

app
  .ws("/*", {
    /* Options */
    compression: CompressOptions.SHARED_COMPRESSOR,
    maxPayloadLength: 16 * 1024 * 1024,
    idleTimeout: 10,
    open: (ws, req) => {
      console.log("A WebSocket connected via URL: " + req.getUrl() + "!");

      console.log(ws, req.getHeader("authorization"));

      const authorization = req.getHeader("authorization");

      if (authorization) {
        const token = authorization.split(" ")[1];
        if (token) {
          ws.userId = getUserIdFromToken;
          if(ws.userId) {
             return;
        }
      }
      // 404 is not a valid websocket error code
      ws.end(404, "Unauthorized");
    },

Problem is that there are not suitable standard websocket error codes that express missing authorization or similar. Also it is not as clean as just doing the authorization before even starting the ws connection.

Right now the getQuery function will ignore any parameter, woudln't it be nice to have the option to get the exact Query you are looking for? Making it optional so it doesn't affect performance at all if no params is sent

Hello

socket.id = 1234;
socket.subscribe("TOPIC1");
socket.subscribe("TOPIC2");

//Any way to do this?
socket.getAllSubscribedTopics();  //returns ["TOPIC1", "TOPIC2"]

How can i get the subscribed topics for a given socket. At the moment i keep a state myself in memory with the socket id and the subscribed topics, but i think the underlying library already keeps this state but i don't see a way to access that state.

Thanks!

Apologies if I missed it, but I can't find a way to read the request body (the data after the headers) in HttpRequest.

This would be needed in handling POST/PUT/... requests.

Thanks in advance

Adding support of CMake, adds possibility to easily integrate uWebSockets to other C++ projects.

For my project I wrote small CMakeLists.txt for uWebSockets and it works very well. So If maintainer of project agrees to add Cmake support I could prepare PR.

Hi. Thanks for library.

I got issue in my library issues, which describes this:

• When testing with stream file, under high-load headers duplicated (up to Infinity)
• When under high-load, even not stream file, headers duplicated (1-5x times)
• When testing with wrk this issue happens too
• If as client using Safari, issue happening less than Chrome

More info here and here

uWS is going to implement the QUIC-based QuicTransport protocol as a complement to WebSocket.

The idea is that since QuicTransport has the concept of URL, it can fit nicely into the app/routes concept that is so central to uWS:

app.qt("/route", { // whatever behavior here })

This can be applicable to web messaging that is not in need of reliable & ordered messaging, such as IO-games.

Description

Memory allocation errors occur when launching 100 servers that do not appear when launching 10 servers in the same configuration.

• OS: Mac OS 10.14
• Node: Homebrew v10.15.2

Code to reproduce

https://github.com/bunchtogether/braid-server/blob/master/tests/peers-ring.test.js

(Apologies, I have been unable to reproduce in a simpler example.)

Output

node(65675,0x1091595c0) malloc: Incorrect checksum for freed object 0x104819200: probably modified after being freed.
Corrupt value: 0x1baffed00baffedf
node(65675,0x1091595c0) malloc: *** set a breakpoint in malloc_error_break to debug

Extended Description

The Braid application syncs key-value pairs between a small network of peers and a larger network of read-only subscribers. All communication between the peer and subscriber processes occurs over WebSockets.

In this test 100 uWebSocket servers are created and linked in a ring using ws, i.e. peer A opens a connection to peer B, peer B opens a connection to peer C, peer C opens a connection to peer A.

When the test is reduced to 10 uWebSocket servers the error does not occur.

Thanks

Thanks for the great work and let me know if there is any additional information I can provide.

(For context, I ran into this problem when trying to have nginx proxy to a uWebSockets C++ program I wrote. The following distills it into an easier case.)

If you connect to a server with a .get() method invoked to provide a get handler and send a request like this:

echo -e "GET / HTTP/1.0\r\n\r\n" | nc localhost 3000 or echo -e "GET / HTTP/1.0\r\nhost: localhost\r\nConnection: close\r\n\r\n" | nc localhost 3000

It times out and the uWS::App().get() handler never gets invoked.

echo -e "GET / HTTP/1.1\r\nhost: localhost\r\nConnection: close\r\n\r\n" | nc localhost 3000 does, however, work.

Here's a trivial server program that demonstrates the failure to handle HTTP/1.0 requests properly: include
#include <App.h>

int main(int argc, char** argv) {

uWS::App().get("/*",[](auto *res, auto *req) { std::cout << "Got a request.\n"; res->end("Foo");}).listen(3000, [](auto *listen_socket) {}).run();                                                                                                         

}

In v.20.34.0

https://github.com/uNetworking/uWebSockets/blob/988fdc7285014911dc34eec512d096fd819682db/src/WebSocket.h#L200

Server crashes here when a WebSocket client that never subscribed to anything disconnects. webSocketData->subscriber is null in this case.

I'm trying to integrate capi web sockets. It looks like uws_res_upgrade leads to a segfault with ssl. The segfault is reproduced in provided example UpgradeSync.c Compiler : gcc (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0

Should have built-in ways for iterating all values in a list header, including repeated headers:

for (auto value : req->getHeaderList("some-header-with-list")) {

}

where delim is comma by default but can also be semi-comma for cookie header.