libcurlwrapper

This library loads CURL from an Aroma Module instead of statically linking it to the binary. This results in a much smaller binary size (saves about 750KiB).

Requires the CURLWrapperModule to be running via WUMSLoader.
Requires wut for building.
Use with curl 7.84.0 headers, other versions might not be compatible.
See important changes in the Usage section.

Install via make install.

Usage

Make sure to define this in your Makefile:

WUMS_ROOT := $(DEVKITPRO)/wums

Use the normal curl headers, but link against -lcurlwrapper instead. For example replace -lcurl -lmbedtls -lmbedx509 -lmbedcrypto -lz with -lcurlwrapper.

If the CURLWrapperModule is not loaded curl_global_init will return a negative value.

Changes compared to normal CURL

libcurlwrapper tries to be a drop-in replacement for libcurl, but some things need to be considered.

All function are only available between calling `curl_global_init` and `curl_global_cleanup`.

Even functions like curl_version only work after calling curl_global_init.

Calling `curl_easy_init` will automatically add CA certificates.

It curl_easy_init returns success, curl_easy_setopt(curl, CURLOPT_CAINFO_BLOB, &blob); with current CA certificates will be called. These CA certificates are coming from the modules and can be updated in the future.

CURLOPT_SOCKOPTFUNCTION

The CURLOPT_SOCKOPTFUNCTION callback requires a workaround to work properly.
This is caused by setsockopt not being compatible with the sockets from the CURLWrapperModule.

Currently, there are two options to get the correct setsockopt function:

Option 1: CURLOPT_SOCKOPTDATA

To get a pointer to the correct setsockopt function, you have to set the CURLOPT_SOCKOPTDATA to 0x13371337.
The 0x13371337 will be replaced with a pointer to the correct setsockopt function.

Example:

static int initSocket(void *ptr, curl_socket_t socket, curlsocktype type) {    
  int r;
  // If ptr is not our magic value, it got replaced with a pointer to a valid setsockopt function.
  if ((uint32_t) ptr != 0x13371337) {
      r = reinterpret_cast<decltype(&setsockopt)>(ptr)(socket, SOL_SOCKET, SO_WINSCALE, &o, sizeof(o));
  } else {
      r = setsockopt(socket, SOL_SOCKET, SO_WINSCALE, &o, sizeof(o));
  }
   return r == 0 ? CURL_SOCKOPT_OK : CURL_SOCKOPT_ERROR;
}
[...]
// Set socktopt data to a magic value to get a pointer to the correct setsockopt function.
curl_easy_setopt(curl, CURLOPT_SOCKOPTDATA, 0x13371337);
curl_easy_setopt(curl, CURLOPT_SOCKOPTFUNCTION, initSocket);

Downside of this option: the data pointer of CURLOPT_SOCKOPTFUNCTION can not be used.

Option 2: curlwrapper_setsockopt

This lib exposes the function curlwrapper_setsockopt which will call the correct function. Because this lib had no headers, you have to declare it in your app like this:

int curlwrapper_setsockopt(int sockfd, int level, int optname, const void *optval, socklen_t optlen);

When using C++, you have to add extern "C" at the start.

Downside of this option: Linking to the original libcurl fails because curlwrapper_setsockopt is only defined in this wrapper lib.

Use this lib in Dockerfiles.

A prebuilt version of this lib can found on dockerhub. To use it for your projects, add this to your Dockerfile.

[...]
COPY --from=ghcr.io/wiiu-env/libcurlwrapper:[tag] /artifacts $DEVKITPRO
[...]

Replace [tag] with a tag you want to use, a list of tags can be found here. It's highly recommended to pin the version to the latest date instead of using latest.

Format the code via docker

docker run --rm -v ${PWD}:/src ghcr.io/wiiu-env/clang-format:13.0.0-2 -r ./source -i

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