PyFCGI/src/pyutils.c

#include "pyutils.h"

void pyinit()
{
	update_python_path();
	Py_Initialize();
}

void update_python_path()
{
	wchar_t *ppath, *wcwd, *wtmp;
	char *cwd, *ncwd, *err_fmt;
	size_t wcwd_sz, ppath_sz;
	int err;
	
	// Add a ':' in front of CWD and convert to wchar_t*
	cwd = get_current_dir_name();
	if(!cwd)
	{
		err = errno;
		err_fmt = "Unable to fecth CWD : %s";
		goto update_python_path_err;
	}
	ncwd = malloc(sizeof(char) * (strlen(cwd) + 2));
	if(!ncwd)
	{
		err = errno;
		err_fmt = "Unable to allocate memory for new CWD : %s";
		goto update_python_path_err_cwd;
	}
	ncwd[0] = ':';
	strcpy(ncwd+1, cwd);
	free(cwd);
	cwd = ncwd;

	wcwd_sz = mbstowcs(NULL, cwd, 0);
	if(wcwd_sz == (size_t)-1)
	{
		err = errno;
		err_fmt = "Unable to convert CWD to wchar : %s";
		goto update_python_path_err_cwd;
	}
	wcwd_sz++;
	wcwd = malloc(sizeof(wchar_t) * wcwd_sz);
	if(!wcwd)
	{
		err = errno;
		err_fmt = "Unable to allocate wchar for CWD : %s";
		goto update_python_path_err_cwd;

	}
	if(mbstowcs(wcwd, cwd, wcwd_sz) == -1)
	{
		err = errno;
		err_fmt = "Unable to convert CWD to wchar : %s";
		goto update_python_path_err_wcwd;
	}

	// Fetch, dup & update the python path
pyfcgi_log(LOG_DEBUG, "DEBUG 0");
	ppath = Py_GetPath();
pyfcgi_log(LOG_DEBUG, "DEBUG 1");
	if(!ppath)
	{
		if(PyErr_Occurred())
		{
			log_expt(LOG_ALERT);
		}
		else
		{
			pyfcgi_log(LOG_ALERT, "Unable to fetch python path, got NULL.");
		}
		err_fmt = NULL;
		err = 0;
		goto update_python_path_err_wcwd;
	}
	ppath = wcsdup(ppath);
	if(!wcwd)
	{
		err = errno;
		err_fmt = "Unable to dup the python PATH : %s";
		goto update_python_path_err_wcwd;
	}

	ppath_sz = wcslen(ppath);
	wtmp = realloc(ppath, sizeof(wchar_t) * (ppath_sz + wcwd_sz + 1));
	if(!wtmp)
	{
		err = errno;
		err_fmt = "Unable reallocate new python path : %s";
		goto update_python_path_err_ppath;
	}
	ppath = wtmp;
	wcsncpy(ppath+ppath_sz, wcwd, wcwd_sz);
	Py_SetPath(ppath);

	free(ppath);
	free(wcwd);
	free(cwd);

	return;
	
update_python_path_err_ppath:
	free(ppath);
update_python_path_err_wcwd:
	free(wcwd);
update_python_path_err_cwd:
	free(cwd);
update_python_path_err:
	if(err_fmt)
	{
		pyfcgi_log( LOG_ALERT, err_fmt, strerror(err));
	}
	exit(err);
}

static PyObject* _fetch_pyflush(const char *fdname)
{
	PyObject *pyfd, *pyflush;
	pyfd = PySys_GetObject(fdname);
	if(!pyfd)
	{
		pyfcgi_log(LOG_ALERT, "Unable to fetch sys.%s", fdname);
		log_expt(LOG_ALERT);
		Py_Exit(EXIT_PYERR);
	}
	pyflush = PyObject_GetAttrString(pyfd, "flush");
	Py_DECREF(pyfd);
	if(!pyflush)
	{
		pyfcgi_log(LOG_ALERT, "Unable to fetch sys.%s.flush", fdname);
		log_expt(LOG_ALERT);
		Py_Exit(EXIT_PYERR);
	}
	if(!PyCallable_Check(pyflush))
	{
		pyfcgi_log(LOG_ALERT, "sys.%s.flush is not callable !",
		       fdname);
		Py_Exit(EXIT_PYERR);
	}

	return pyflush;
}

void fetch_pyflush(PyObject** pystdout_flush, PyObject** pystderr_flush)
{
	*pystdout_flush = _fetch_pyflush("stdout");
	*pystderr_flush = _fetch_pyflush("stderr");
}

void update_python_fd(int pipe_out[2], int pipe_err[2])
{
	int pri, err;
	char *err_fmt;
	PyObject *os_mod, *pyfdopen, *args, *new_fd;

	pri = LOG_ALERT;

	if(pipe2(pipe_out, O_DIRECT) == -1)
	{
		err = errno;
		err_fmt = "Unable to create pipe for python stdout : %s";
		goto update_python_fd_err;
	}
	if(pipe2(pipe_err, O_DIRECT) == -1)
	{
		err = errno;
		err_fmt = "Unable to create pipe for python stderr : %s";
		goto update_python_fd_err_pipeout;
	}

	os_mod = PyImport_ImportModule("os");
	if(!os_mod)
	{
		if(PyErr_Occurred())
		{
			log_expt(LOG_ALERT);
		}
		else
		{
			pyfcgi_log(	LOG_ALERT,
				"Unable to import python os module, got NULL.");
		}
		err_fmt = NULL;
		goto update_python_fd_err_pipes;
	}
	pyfdopen = PyObject_GetAttrString(os_mod, "fdopen");
	Py_DECREF(os_mod);
	if(!pyfdopen)
	{
		if(PyErr_Occurred())
		{
			log_expt(LOG_ALERT);
		}
		else
		{
			pyfcgi_log(	LOG_ALERT,
				"Unable to fetch os.fdopen() , got NULL.");
		}
		err_fmt = NULL;
		goto update_python_fd_err_pipes;
	}

	args = Py_BuildValue("is", pipe_out[1], "w");
	if(!args)
	{
		pyfcgi_log(	LOG_ERR, "Error building values with '%d', '%s' for stdout",
			pipe_out[1], "w");
		log_expt(LOG_ALERT);
		err_fmt = NULL;
		goto update_python_fd_err_fdopen;
	}
	new_fd = PyObject_CallObject(pyfdopen, args);
	if(!new_fd || PyErr_Occurred())
	{
		pyfcgi_log(	LOG_ERR, "Error calling fdopen(%d, '%s')",
			pipe_out[1], "w");
		log_expt(LOG_ALERT);
		err_fmt = NULL;
		goto update_python_fd_err_args;
	}
	Py_DECREF(args);
	if(PySys_SetObject("stdout", new_fd))
	{
		pyfcgi_log(LOG_ERR, "Unable to set sys.stdout");
		log_expt(LOG_ALERT);
		goto update_python_fd_err_newfd;
	}
	Py_DECREF(new_fd);

	args = Py_BuildValue("is", pipe_err[1], "w");
	if(!args)
	{
		pyfcgi_log(	LOG_ERR, "Error building values with '%d', '%s' for stderr",
			pipe_out[1], "w");
		log_expt(LOG_ALERT);
		err_fmt = NULL;
		goto update_python_fd_err_fdopen;
	}
	new_fd = PyObject_CallObject(pyfdopen, args);
	if(!new_fd || PyErr_Occurred())
	{
		pyfcgi_log(	LOG_ERR, "Error calling fdopen(%d, '%s')",
			pipe_out[1], "w");
		log_expt(LOG_ALERT);
		err_fmt = NULL;
		goto update_python_fd_err_args;
	}
	Py_DECREF(args);
	if(PySys_SetObject("stderr", new_fd))
	{
		pyfcgi_log(LOG_ERR, "Unable to set sys.stderr");
		log_expt(LOG_ALERT);
		goto update_python_fd_err_newfd;
	}
	Py_DECREF(new_fd);

	return;

update_python_fd_err_newfd:
	Py_DECREF(new_fd);
update_python_fd_err_args:
	Py_DECREF(args);
update_python_fd_err_fdopen:
	Py_DECREF(fdopen);
update_python_fd_err_pipes:
	close(pipe_err[0]);
	close(pipe_err[1]);
update_python_fd_err_pipeout:
	close(pipe_out[0]);
	close(pipe_out[1]);
update_python_fd_err:
	if(err_fmt)
	{
		pyfcgi_log(pri, err_fmt, strerror(err));
	}
	exit(1);
}


PyObject* update_pyenv(PyObject *py_osmod, char **environ)
{
	PyObject *pyenv, *pykey, *pyval;
	char *key, *value, **cur;

	cur = environ;

	pyenv = PyObject_GetAttrString(py_osmod, "environ");
	if(!pyenv)
	{
		pyfcgi_log(LOG_WARNING, "Unable to get os.environ");
		log_expt(LOG_ALERT);
	}
	else
	{
		Py_DECREF(pyenv);
	}
	pyenv = PyDict_New();



	while(*cur)
	{
		key = value = *cur;
		while(*value && *value != '=')
		{
			value++;
		}
		if(!*value)
		{
			pyfcgi_log(LOG_WARNING, "Droping environment value without value : '%s'",
			       key);
			cur++;
			continue;
		}
		value++;
		*(value-1) = '\0'; // dirty modification of **environ
//pyfcgi_log(LOG_DEBUG, "PySetEnv '%s'='%s'", key, value);
		pykey = PyUnicode_DecodeLocale(key, "surrogateescape");
		if(!pykey)
		{
			*(value-1) = '='; // **environ restore
			pyfcgi_log(LOG_ALERT, "Unable to parse environ key string '%s'",
			       key);
			log_expt(LOG_ALERT);
			Py_Exit(EXIT_PYERR);
		}
		*(value-1) = '='; // **environ restore
		pyval = PyUnicode_DecodeFSDefault(value);
		if(!pyval)
		{
			pyfcgi_log(LOG_ALERT, "Unable to parse environ val string '%s'",
			       value);
			log_expt(LOG_ALERT);
			Py_Exit(EXIT_PYERR);
		}
		if(PyDict_SetItem(pyenv, pykey, pyval) == -1)
		{
			pyfcgi_log(LOG_ERR, "Unable to set environ '%s'='%s'",
			       key, value);
			log_expt(LOG_ERR);
		}
		Py_DECREF(pyval);
		Py_DECREF(pykey);
		cur++;
	}
	PyObject_SetAttrString(py_osmod, "environ", pyenv);
	return pyenv;
}

PyObject* import_entrypoint()
{
	PyObject *entry_fname, *entry_module, *entry_fun;
	entry_fname = PyUnicode_DecodeFSDefault(PyFCGI_conf.py_entrymod);
	entry_module = PyImport_Import(entry_fname);
	Py_DECREF(entry_fname);

	if(!entry_module)
	{
		//TODO syslog python error / traceback
		pyfcgi_log(LOG_CRIT, "Unable to import python file '%s'",
			PyFCGI_conf.py_entrymod);
		//pyfcgi_log( LOG_INFO, "%s", getcwd(NULL, 256));
		log_expt(LOG_ERR);
		return NULL;
	}

	// getting entrypoint function
	entry_fun = PyObject_GetAttrString(entry_module, PyFCGI_conf.py_entryfun);
	Py_DECREF(entry_module);

	if(!entry_fun)
	{
		//TODO syslog python error / traceback
		pyfcgi_log(LOG_CRIT,
			"Unable to import object '%s' from '%s'",
			PyFCGI_conf.py_entryfun, PyFCGI_conf.py_entrymod);
		log_expt(LOG_ERR);
		return NULL;
	}
	if(!PyCallable_Check(entry_fun))
	{
		pyfcgi_log( LOG_CRIT,
			"When imported from '%s', '%s' was not a callable",
			PyFCGI_conf.py_entrymod, PyFCGI_conf.py_entryfun);
		return NULL;
	}
	return entry_fun;
}

PyObject* get_start_response()
{
	PyObject *module;
	if(!libpyfcgi.self)
	{
		module = PyInit_libpyfcgi();
		if(module == NULL)
		{
			pyfcgi_log(LOG_ERR, "Unable to create libpyfcgi python module");
			return NULL;
		}
		libpyfcgi.self = module;
	}
	return PyObject_GetAttrString(libpyfcgi.self, "start_response");
}

void log_expt(int priority)
{
	if(!PyErr_Occurred())
	{
		pyfcgi_log(priority, "No exception");
		return;
	}

	PyObject *expt, *expt_bytes, *expt_cls,
		*expt_val, *expt_type, *traceback;
	char *msg, *type, *val;
	int msg_sz;
	char msg_fmt[] = "%s: %s";

	PyErr_Fetch(&expt_cls, &expt, &traceback);

	// Fetching exception message using __str__()
	expt_val = PyObject_ASCII(expt);
	expt_bytes = PyUnicode_AsUTF8String(expt_val);

	msg = PyBytes_AsString(expt_bytes);
	val = strndup(msg, 1024); // TODO check out of mem if !val

	// Fetching exception class name
	expt_type = PyObject_GetAttrString(expt_cls, "__name__");
	expt_bytes = PyUnicode_AsUTF8String(expt_type);
	msg = PyBytes_AsString(expt_bytes);
	type = strndup(msg, 1024); // TODO check out of mem if !type

	msg_sz = snprintf(NULL, 0, msg_fmt, type, val);
	msg_sz++;
	msg = malloc(sizeof(char) * msg_sz);
	snprintf(msg, msg_sz, msg_fmt, type, val);

	pyfcgi_log(priority, msg);
}

void pyfcgi_python_version(char version[16])
{
	snprintf(version, 16, "%d.%d.%d", PY_MAJOR_VERSION, PY_MINOR_VERSION,
		PY_MICRO_VERSION);
}

PyObject* python_osmod()
{
	PyObject *ret;
	ret = PyImport_ImportModule("os");
	if(!ret)
	{
		pyfcgi_log(LOG_ALERT, "Unable to import os module");
		log_expt(LOG_ALERT);
		Py_Exit(EXIT_PYERR);
	}
	return ret;
}