kea/src/lib/dns/python/rcode_python.cc

// Copyright (C) 2010  Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.

#include <Python.h>

#include <exceptions/exceptions.h>
#include <dns/rcode.h>
#include <util/python/pycppwrapper_util.h>

#include "pydnspp_common.h"
#include "rcode_python.h"

using namespace isc::dns;
using namespace isc::dns::python;
using namespace isc::util::python;

namespace {
// The s_* Class simply covers one instantiation of the object.
//
// We added a helper variable static_code here
// Since we can create Rcodes dynamically with Rcode(int), but also
// use the static globals (Rcode::NOERROR() etc), we use this
// variable to see if the code came from one of the latter, in which
// case Rcode_destroy should not free it (the other option is to
// allocate new Rcodes for every use of the static ones, but this
// seems more efficient).
//
// Follow-up note: we don't have to use the proxy function in the python lib;
// we can just define class specific constants directly (see TSIGError).
// We should make this cleanup later.
class s_Rcode : public PyObject {
public:
    s_Rcode() : cppobj(NULL), static_code(false) {};
    const Rcode* cppobj;
    bool static_code;
};

typedef CPPPyObjectContainer<s_Rcode, Rcode> RcodeContainer;

int Rcode_init(s_Rcode* const self, PyObject* args);
void Rcode_destroy(s_Rcode* const self);

PyObject* Rcode_getCode(const s_Rcode* const self);
PyObject* Rcode_getExtendedCode(const s_Rcode* const self);
PyObject* Rcode_toText(const s_Rcode* const self);
PyObject* Rcode_str(PyObject* self);
PyObject* Rcode_richcmp(const s_Rcode* const self,
                         const s_Rcode* const other, int op);

PyMethodDef Rcode_methods[] = {
    { "get_code", reinterpret_cast<PyCFunction>(Rcode_getCode), METH_NOARGS,
      "Returns the code value" },
    { "get_extended_code",
      reinterpret_cast<PyCFunction>(Rcode_getExtendedCode), METH_NOARGS,
      "Returns the upper 8-bit part of the extended code value" },
    { "to_text", reinterpret_cast<PyCFunction>(Rcode_toText), METH_NOARGS,
      "Returns the text representation" },
    { NULL, NULL, 0, NULL }
};

int
Rcode_init(s_Rcode* const self, PyObject* args) {
    long code = 0;
    int ext_code = 0;

    if (PyArg_ParseTuple(args, "l", &code)) {
        if (code < 0 || code > 0xffff) {
            PyErr_SetString(PyExc_ValueError, "Rcode out of range");
            return (-1);
        }
        ext_code = -1;
    } else if (PyArg_ParseTuple(args, "li", &code, &ext_code)) {
        if (code < 0 || code > 0xff || ext_code < 0 || ext_code > 0xff) {
            PyErr_SetString(PyExc_ValueError, "Rcode out of range");
            return (-1);
        }
    } else {
        PyErr_Clear();
        PyErr_SetString(PyExc_TypeError,
                        "Invalid arguments to Rcode constructor");
        return (-1);
    }
    try {
        if (ext_code == -1) {
            self->cppobj = new Rcode(code);
        } else {
            self->cppobj = new Rcode(code, ext_code);
        }
        self->static_code = false;
    } catch (const isc::OutOfRange& ex) {
            PyErr_SetString(PyExc_OverflowError, ex.what());
            return (-1);
    } catch (...) {
        PyErr_SetString(po_IscException, "Unexpected exception");
        return (-1);
    }
    return (0);
}

void
Rcode_destroy(s_Rcode* const self) {
    // Depending on whether we created the rcode or are referring
    // to a global one, we do or do not delete self->cppobj here
    if (!self->static_code) {
        delete self->cppobj;
    }
    self->cppobj = NULL;
    Py_TYPE(self)->tp_free(self);
}

PyObject*
Rcode_getCode(const s_Rcode* const self) {
    return (Py_BuildValue("I", self->cppobj->getCode()));
}

PyObject*
Rcode_getExtendedCode(const s_Rcode* const self) {
    return (Py_BuildValue("I", self->cppobj->getExtendedCode()));
}

PyObject*
Rcode_toText(const s_Rcode* const self) {
    return (Py_BuildValue("s", self->cppobj->toText().c_str()));
}

PyObject*
Rcode_str(PyObject* self) {
    // Simply call the to_text method we already defined
    return (PyObject_CallMethod(self, const_cast<char*>("to_text"),
                                const_cast<char*>("")));
}

PyObject*
Rcode_richcmp(const s_Rcode* const self, const s_Rcode* const other,
              const int op)
{
    bool c = false;

    // Check for null and if the types match. If different type,
    // simply return False
    if (!other || (self->ob_type != other->ob_type)) {
        Py_RETURN_FALSE;
    }

    // Only equals and not equals here, unorderable type
    switch (op) {
    case Py_LT:
        PyErr_SetString(PyExc_TypeError, "Unorderable type; Rcode");
        return (NULL);
    case Py_LE:
        PyErr_SetString(PyExc_TypeError, "Unorderable type; Rcode");
        return (NULL);
    case Py_EQ:
        c = (*self->cppobj == *other->cppobj);
        break;
    case Py_NE:
        c = (*self->cppobj != *other->cppobj);
        break;
    case Py_GT:
        PyErr_SetString(PyExc_TypeError, "Unorderable type; Rcode");
        return (NULL);
    case Py_GE:
        PyErr_SetString(PyExc_TypeError, "Unorderable type; Rcode");
        return (NULL);
    }
    if (c)
        Py_RETURN_TRUE;
    else
        Py_RETURN_FALSE;
}
} // end of unnamed namespace

namespace isc {
namespace dns {
namespace python {
PyTypeObject rcode_type = {
    PyVarObject_HEAD_INIT(NULL, 0)
    "pydnspp.Rcode",
    sizeof(s_Rcode),                    // tp_basicsize
    0,                                  // tp_itemsize
    (destructor)Rcode_destroy,          // tp_dealloc
    NULL,                               // tp_print
    NULL,                               // tp_getattr
    NULL,                               // tp_setattr
    NULL,                               // tp_reserved
    NULL,                               // tp_repr
    NULL,                               // tp_as_number
    NULL,                               // tp_as_sequence
    NULL,                               // tp_as_mapping
    NULL,                               // tp_hash
    NULL,                               // tp_call
    Rcode_str,                          // tp_str
    NULL,                               // tp_getattro
    NULL,                               // tp_setattro
    NULL,                               // tp_as_buffer
    Py_TPFLAGS_DEFAULT,                 // tp_flags
    "The Rcode class objects represent standard RCODEs"
    "of the header section of DNS messages.",
    NULL,                               // tp_traverse
    NULL,                               // tp_clear
    reinterpret_cast<richcmpfunc>(Rcode_richcmp),         // tp_richcompare
    0,                                  // tp_weaklistoffset
    NULL,                               // tp_iter
    NULL,                               // tp_iternext
    Rcode_methods,                      // tp_methods
    NULL,                               // tp_members
    NULL,                               // tp_getset
    NULL,                               // tp_base
    NULL,                               // tp_dict
    NULL,                               // tp_descr_get
    NULL,                               // tp_descr_set
    0,                                  // tp_dictoffset
    (initproc)Rcode_init,               // tp_init
    NULL,                               // tp_alloc
    PyType_GenericNew,                  // tp_new
    NULL,                               // tp_free
    NULL,                               // tp_is_gc
    NULL,                               // tp_bases
    NULL,                               // tp_mro
    NULL,                               // tp_cache
    NULL,                               // tp_subclasses
    NULL,                               // tp_weaklist
    NULL,                               // tp_del
    0                                   // tp_version_tag
};

PyObject*
createRcodeObject(const Rcode& source) {
    RcodeContainer container(PyObject_New(s_Rcode, &rcode_type));
    container.set(new Rcode(source));
    return (container.release());
}

bool
PyRcode_Check(PyObject* obj) {
    if (obj == NULL) {
        isc_throw(PyCPPWrapperException, "obj argument NULL in typecheck");
    }
    return (PyObject_TypeCheck(obj, &rcode_type));
}

const Rcode&
PyRcode_ToRcode(const PyObject* rcode_obj) {
    if (rcode_obj == NULL) {
        isc_throw(PyCPPWrapperException,
                  "obj argument NULL in Rcode PyObject conversion");
    }
    const s_Rcode* rcode = static_cast<const s_Rcode*>(rcode_obj);
    return (*rcode->cppobj);
}

} // namespace python
} // namespace dns
} // namespace isc