pylwan.c

#include "Python.h"

#include "lwan/lwan.h"

/*
  Compile with:
	gcc `python3-config --cflags` -I/usr/local/include/lwan /usr/local/lib/liblwan.a `python3-config --ldflags` server.c -lz -o pylw

  Run with:
  ./pylw wsgi.py
  
  wsgi.py
  
  def app(environ):
    print("App() {}".format(environ))
*/

PyObject *wsgi_handler = NULL;

static lwan_http_status_t
request_handler(lwan_request_t *request,
                lwan_response_t *response) 
{
    const char *ip_address;
    char ip_address_buf[INET6_ADDRSTRLEN];

    PyObject *resp;
    PyObject *environ = PyDict_New();

    ip_address = lwan_request_get_remote_address(request, ip_address_buf);

    if (UNLIKELY(!ip_address))
        return HTTP_INTERNAL_ERROR;

    PyGILState_STATE _st = PyGILState_Ensure();

    if (wsgi_handler && PyCallable_Check(wsgi_handler)) {
        Py_XINCREF(environ);
        PyDict_SetItemString(environ, "ip", Py_BuildValue("s", ip_address_buf));
        resp = PyObject_CallFunctionObjArgs(wsgi_handler, environ, NULL);
        if (!resp) {
            PyErr_Print();
        }
        Py_XDECREF(environ);
    } else  {
        PyErr_Print();

    }

    printf("%s\n", ip_address_buf);

    PyGILState_Release(_st);

    return HTTP_OK;
}

int main(int argc, char **argv) {
    int i;
    lwan_t l;
    lwan_config_t c;
    PyObject *pName, *pModule;

    Py_Initialize();
    PyEval_InitThreads();

    wchar_t *program = Py_DecodeLocale(argv[0], NULL);
    pName = PyUnicode_DecodeFSDefault(argv[1]);

    pModule = PyImport_Import(pName);
    Py_DECREF(pName);
    Py_XINCREF(pModule);

    if (program == NULL) {
        fprintf(stderr, "Fatal error: cannot decode argv[0]\n");
        return -1;
    }

    Py_SetProgramName(program);

    if (pModule) {
        wsgi_handler = PyObject_GetAttrString(pModule, "app");
        Py_XINCREF(wsgi_handler);
    } else {
        PyErr_Print();
        return -1;
    }

    c = *lwan_get_default_config();
    c.listener = strdup("*:8080");

    const lwan_url_map_t default_map[] = {
        { .prefix = "/", .handler = request_handler},
    };

    lwan_init_with_config(&l, &c);
    lwan_set_url_map(&l, default_map);

    Py_BEGIN_ALLOW_THREADS
    lwan_main_loop(&l);
    lwan_shutdown(&l);
    Py_END_ALLOW_THREADS

    Py_XDECREF(wsgi_handler);
    Py_XDECREF(pModule);

    Py_Finalize();
    PyMem_RawFree(program);

    return 0;
}