rlm_python.c

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/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or (at
 *   your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: 7bc08eda6b3a69329bcb8f1578906e3ef93ed693 $
 * @file rlm_python.c
 * @brief Translates requests between the server an a python interpreter.
 *
 * @note Rewritten by Nick Porter for FreeRADIUS v4
 *
 * @copyright 2000,2006,2015-2016 The FreeRADIUS server project
 * @copyright 2025 Network RADIUS SAS
 */
RCSID("$Id: 7bc08eda6b3a69329bcb8f1578906e3ef93ed693 $")
 
#define LOG_PREFIX inst->name
 
#include <freeradius-devel/server/base.h>
#include <freeradius-devel/server/module_rlm.h>
#include <freeradius-devel/util/debug.h>
#include <freeradius-devel/util/lsan.h>
 
#include <Python.h>
#include <structmember.h>
#include <frameobject.h> /* Python header not pulled in by default. */
#include <libgen.h>
#include <dlfcn.h>
 
/** Specifies the module.function to load for processing a section
 *
 */
typedef struct {
        PyObject        *module;                //!< Python reference to module.
        PyObject        *function;              //!< Python reference to function in module.
 
        char const      *module_name;           //!< String name of module.
        char const      *function_name;         //!< String name of function in module.
        char            *name1;                 //!< Section name1 where this is called.
        char            *name2;                 //!< Section name2 where this is called.
        fr_rb_node_t    node;                   //!< Entry in tree of Python functions.
} python_func_def_t;
 
/** An instance of the rlm_python module
 *
 */
typedef struct {
        char const      *name;                  //!< Name of the module instance
        PyThreadState   *interpreter;           //!< The interpreter used for this instance of rlm_python.
        PyObject        *module;                //!< Local, interpreter specific module.
        char const      *def_module_name;       //!< Default module for Python functions
        fr_rb_tree_t    funcs;                  //!< Tree of function calls found by call_env parser
        bool            funcs_init;             //!< Has the tree been initialised.
 
        python_func_def_t
        instantiate,
        detach;
 
        PyObject        *pythonconf_dict;       //!< Configuration parameters defined in the module
                                                //!< made available to the python script.
} rlm_python_t;
 
/** Global config for python library
 *
 */
typedef struct {
        char const      *path;                  //!< Path to search for python files in.
        bool            path_include_default;   //!< Include the default python path in `path`
        bool            verbose;                //!< Enable libpython verbose logging
} libpython_global_config_t;
 
typedef struct {
        python_func_def_t       *func;
} python_call_env_t;
 
/** Tracks a python module inst/thread state pair
 *
 * Multiple instances of python create multiple interpreters and each
 * thread must have a PyThreadState per interpreter, to track execution.
 */
typedef struct {
        rlm_python_t const      *inst;          //!< Current module instance data.
        PyThreadState           *state;         //!< Module instance/thread specific state.
} rlm_python_thread_t;
 
/** Additional fields for pairs
 *
 */
typedef struct {
        PyObject_HEAD                           //!< Common fields needed for every python object.
        fr_dict_attr_t const    *da;            //!< dictionary attribute for this pair.
        fr_pair_t               *vp;            //!< Real FreeRADIUS pair for this Python pair.
        unsigned int            idx;            //!< Instance index.
        PyObject                *parent;        //!< Parent object of this pair.
} py_freeradius_pair_t;
 
typedef struct {
        PyObject_HEAD                           //!< Common fields needed for every python object.
        PyObject                *request;       //!< Request list.
        PyObject                *reply;         //!< Reply list.
        PyObject                *control;       //!< Control list.
        PyObject                *state;         //!< Session state list.
} py_freeradius_request_t;
 
/** Wrapper around a python instance
 *
 * This is added to the FreeRADIUS module to allow us to
 * get at the global and thread local instance data.
 */
typedef struct {
        PyObject_HEAD                           //!< Common fields needed for every python object.
        rlm_python_t const      *inst;          //!< Module instance.
        rlm_python_thread_t     *t;             //!< Thread-specific python instance.
        request_t               *request;       //!< Current request.
} py_freeradius_state_t;
 
static void                     *python_dlhandle;
static PyThreadState            *global_interpreter;    //!< Our first interpreter.
 
static rlm_python_t const       *current_inst = NULL;   //!< Used for communication with inittab functions.
static rlm_python_thread_t      *current_t;             //!< Used for communicating with object init function.
 
static PyObject *py_freeradius_log(UNUSED PyObject *self, PyObject *args, PyObject *kwds);
 
static int      py_freeradius_state_init(PyObject *self, UNUSED PyObject *args, UNUSED PyObject *kwds);
 
static PyObject *py_freeradius_pair_map_subscript(PyObject *self, PyObject *attr);
static PyObject *py_freeradius_attribute_instance(PyObject *self, PyObject *attr);
static int      py_freeradius_pair_map_set(PyObject* self, PyObject* attr, PyObject* value);
static PyObject *py_freeradius_pair_getvalue(PyObject *self, void *closure);
static int      py_freeradius_pair_setvalue(PyObject *self, PyObject *value, void *closure);
static PyObject *py_freeradius_pair_str(PyObject *self);
 
static libpython_global_config_t libpython_global_config = {
        .path = NULL,
        .path_include_default = true
};
 
static conf_parser_t const python_global_config[] = {
        { FR_CONF_OFFSET("path", libpython_global_config_t, path) },
        { FR_CONF_OFFSET("path_include_default", libpython_global_config_t, path_include_default) },
        { FR_CONF_OFFSET("verbose", libpython_global_config_t, verbose) },
        CONF_PARSER_TERMINATOR
};
 
static int libpython_init(void);
static void libpython_free(void);
 
static global_lib_autoinst_t rlm_python_autoinst = {
        .name = "python",
        .config = python_global_config,
        .init = libpython_init,
        .free = libpython_free,
        .inst = &libpython_global_config
};
 
extern global_lib_autoinst_t const * const rlm_python_lib[];
global_lib_autoinst_t const * const rlm_python_lib[] = {
        &rlm_python_autoinst,
        GLOBAL_LIB_TERMINATOR
};
 
/*
 *      As of Python 3.8 the GIL will be per-interpreter
 *      If there are still issues with CEXTs,
 *      multiple interpreters and the GIL at that point
 *      users can build rlm_python against Python 3.8
 *      and the horrible hack of using a single interpreter
 *      for all instances of rlm_python will no longer be
 *      required.
 */
 
/*
 *      A mapping of configuration file names to internal variables.
 */
static conf_parser_t module_config[] = {
 
#define A(x) { FR_CONF_OFFSET("mod_" #x, rlm_python_t, x.module_name), .dflt = "${.module}" }, \
        { FR_CONF_OFFSET("func_" #x, rlm_python_t, x.function_name) },
 
        A(instantiate)
        A(detach)
 
#undef A
 
        { FR_CONF_OFFSET("module", rlm_python_t, def_module_name) },
 
        CONF_PARSER_TERMINATOR
};
 
static struct {
        char const *name;
        int  value;
} freeradius_constants[] = {
 
#define A(x) { #x, x },
 
        A(L_DBG)
        A(L_WARN)
        A(L_INFO)
        A(L_ERR)
        A(L_WARN)
        A(L_DBG_WARN)
        A(L_DBG_ERR)
        A(L_DBG_WARN_REQ)
        A(L_DBG_ERR_REQ)
        A(L_DBG_LVL_OFF)
        A(L_DBG_LVL_1)
        A(L_DBG_LVL_2)
        A(L_DBG_LVL_3)
        A(L_DBG_LVL_4)
        A(L_DBG_LVL_MAX)
        A(RLM_MODULE_REJECT)
        A(RLM_MODULE_FAIL)
        A(RLM_MODULE_OK)
        A(RLM_MODULE_HANDLED)
        A(RLM_MODULE_INVALID)
        A(RLM_MODULE_DISALLOW)
        A(RLM_MODULE_NOTFOUND)
        A(RLM_MODULE_NOOP)
        A(RLM_MODULE_UPDATED)
        A(RLM_MODULE_TIMEOUT)
#undef A
 
        { NULL, 0 },
};
 
/** The class which all pair types inherit from
 *
 */
static PyTypeObject py_freeradius_pair_def = {
        PyVarObject_HEAD_INIT(NULL, 0)
        .tp_name = "freeradius.Pair",
        .tp_doc = "An attribute value pair",
        .tp_basicsize = sizeof(py_freeradius_pair_t),
        .tp_itemsize = 0,
        .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
        .tp_new = PyType_GenericNew,
};
 
/** How to access "value" attribute of a pair
 *
 */
static PyGetSetDef py_freeradius_pair_getset[] = {
        {
                .name = "value",
                .get = py_freeradius_pair_getvalue,
                .set = py_freeradius_pair_setvalue,
                .doc = "Pair value",
                .closure = NULL
        },
        { .name = NULL }        /* Terminator */
};
 
/** Contains a value pair of a specific type
 *
 */
static PyTypeObject py_freeradius_value_pair_def = {
        PyVarObject_HEAD_INIT(NULL, 0)
        .tp_name = "freeradius.ValuePair",
        .tp_doc = "A value pair, i.e. one of the type string, integer, ipaddr etc...)",
        .tp_flags = Py_TPFLAGS_DEFAULT,
        .tp_base = &py_freeradius_pair_def,
        .tp_getset = py_freeradius_pair_getset,
        .tp_str = py_freeradius_pair_str,
        .tp_as_mapping = &(PyMappingMethods) {
                .mp_subscript = py_freeradius_attribute_instance,
                .mp_ass_subscript = py_freeradius_pair_map_set,
        }
};
 
/** Contains group attribute of a specific type
 *
 * Children of this attribute may be accessed using the map protocol
 * i.e. foo['child-of-foo'].
 *
 */
static PyTypeObject py_freeradius_grouping_pair_def = {
        PyVarObject_HEAD_INIT(NULL, 0)
        .tp_name = "freeradius.GroupingPair",
        .tp_doc = "A grouping pair, i.e. one of the type group, tlv, vsa or vendor.  "
                  "Children are accessible via the mapping protocol i.e. foo['child-of-foo]",
        .tp_flags = Py_TPFLAGS_DEFAULT,
        .tp_base = &py_freeradius_pair_def,
        .tp_as_mapping = &(PyMappingMethods){
                .mp_subscript = py_freeradius_pair_map_subscript,
                .mp_ass_subscript = py_freeradius_pair_map_set,
        }
};
 
/** Each instance contains a top level list (i.e. request, reply, control, session-state)
 */
static PyTypeObject py_freeradius_pair_list_def = {
        PyVarObject_HEAD_INIT(NULL, 0)
        .tp_name = "freeradius.PairList",
        .tp_doc = "A list of objects of freeradius.GroupingPairList and freeradius.ValuePair",
        .tp_flags = Py_TPFLAGS_DEFAULT,
        .tp_base = &py_freeradius_pair_def,
        .tp_as_mapping = &(PyMappingMethods){
                .mp_subscript = py_freeradius_pair_map_subscript,
                .mp_ass_subscript = py_freeradius_pair_map_set,
        }
};
 
static PyMemberDef py_freeradius_request_attrs[] = {
        {
                .name = "request",
                .type = T_OBJECT,
                .offset = offsetof(py_freeradius_request_t, request),
                .flags = READONLY,
                .doc = "Pairs in the request list - received from the network"
        },
        {
                .name = "reply",
                .type = T_OBJECT,
                .offset = offsetof(py_freeradius_request_t, reply),
                .flags = READONLY,
                .doc = "Pairs in the reply list - sent to the network"
        },
        {
                .name = "control",
                .type = T_OBJECT,
                .offset = offsetof(py_freeradius_request_t, control),
                .flags = READONLY,
                .doc = "Pairs in the control list - control the behaviour of subsequently called modules"
        },
        {
                .name = "session-state",
                .type = T_OBJECT,
                .offset = offsetof(py_freeradius_request_t, state),
                .flags = READONLY,
                .doc = "Pairs in the session-state list - persists for the length of the session"
        },
        { .name = NULL }        /* Terminator */
};
 
static PyTypeObject py_freeradius_request_def = {
        PyVarObject_HEAD_INIT(NULL, 0)
        .tp_name = "freeradius.Request",
        .tp_doc = "freeradius request handle",
        .tp_basicsize = sizeof(py_freeradius_request_t),
        .tp_itemsize = 0,
        .tp_flags = Py_TPFLAGS_DEFAULT,
        .tp_new = PyType_GenericNew,
        .tp_members = py_freeradius_request_attrs
};
 
static PyTypeObject py_freeradius_state_def = {
        PyVarObject_HEAD_INIT(NULL, 0)
        .tp_name = "freeradius.State",
        .tp_doc = "Private state data",
        .tp_basicsize = sizeof(py_freeradius_state_t),
        .tp_itemsize = 0,
        .tp_flags = Py_TPFLAGS_DEFAULT,
        .tp_new = PyType_GenericNew,
        .tp_init = py_freeradius_state_init
};
 
#ifndef _PyCFunction_CAST
#define _PyCFunction_CAST(func) (PyCFunction)((void(*)(void))(func))
#endif
 
/*
 *      freeradius Python functions
 */
static PyMethodDef py_freeradius_methods[] = {
        { "log", _PyCFunction_CAST(py_freeradius_log), METH_VARARGS | METH_KEYWORDS,
          "freeradius.log(msg[, type, lvl])\n\n"
          "Print a message using the freeradius daemon's logging system.\n"
          "type should be one of the following constants:\n"
          "        freeradius.L_DBG\n"
          "        freeradius.L_INFO\n"
          "        freeradius.L_WARN\n"
          "        freeradius.L_ERR\n"
          "lvl should be one of the following constants:\n"
          "        freeradius.L_DBG_LVL_OFF\n"
          "        freeradius.L_DBG_LVL_1\n"
          "        freeradius.L_DBG_LVL_2\n"
          "        freeradius.L_DBG_LVL_3\n"
          "        freeradius.L_DBG_LVL_4\n"
          "        freeradius.L_DBG_LVL_MAX\n"
        },
        { NULL, NULL, 0, NULL },
};
 
static PyModuleDef py_freeradius_def = {
        PyModuleDef_HEAD_INIT,
        .m_name = "freeradius",
        .m_doc = "FreeRADIUS python module",
        .m_size = 0,
        .m_methods = py_freeradius_methods
};
 
/** How to compare two Python calls
 *
 */
static fr_cmp_ret_t python_func_def_cmp(void const *one, void const *two)
{
        python_func_def_t const *a = one, *b = two;
        int ret;
 
        ret = strcmp(a->name1, b->name1);
        if (ret != 0) return CMP(ret, 0);
        if (!a->name2 && !b->name2) return CMP_EQ;
        if (!a->name2 || !b->name2) return a->name2 ? CMP_GT : CMP_LT;
        ret = strcmp(a->name2, b->name2);
        return CMP(ret, 0);
}
 
/** Return the module instance object associated with the thread state or interpreter state
 *
 */
static inline CC_HINT(always_inline) py_freeradius_state_t *rlm_python_state_obj(void)
{
        PyObject *dict;
 
        dict = PyThreadState_GetDict(); /* If this is NULL, we're dealing with the main interpreter */
        if (!dict) {
                PyObject *module;
 
                module = PyState_FindModule(&py_freeradius_def);
                if (unlikely(!module)) return NULL;
 
                dict = PyModule_GetDict(module);
                if (unlikely(!dict)) return NULL;
        }
 
        return (py_freeradius_state_t *)PyDict_GetItemString(dict, "__State");
}
 
/** Return the rlm_python instance associated with the current interpreter
 *
 */
static rlm_python_t const *rlm_python_get_inst(void)
{
        py_freeradius_state_t const *p_state;
 
        p_state = rlm_python_state_obj();
        if (unlikely(!p_state)) return NULL;
        return p_state->inst;
}
 
/** Return the request associated with the current thread state
 *
 */
static request_t *rlm_python_get_request(void)
{
        py_freeradius_state_t const *p_state;
 
        p_state = rlm_python_state_obj();
        if (unlikely(!p_state)) return NULL;
 
        return p_state->request;
}
 
/** Set the request associated with the current thread state
 *
 */
static void rlm_python_set_request(request_t *request)
{
        py_freeradius_state_t *p_state;
 
        p_state = rlm_python_state_obj();
        if (unlikely(!p_state)) return;
 
        p_state->request = request;
}
 
/** Allow fr_log to be called from python
 *
 */
static PyObject *py_freeradius_log(UNUSED PyObject *self, PyObject *args, PyObject *kwds)
{
        static char const       *kwlist[] = { "msg", "type", "lvl", NULL };
        char                    *msg;
        int                     type = L_DBG;
        int                     lvl = L_DBG_LVL_2;
        rlm_python_t const      *inst = rlm_python_get_inst();
 
        if (fr_debug_lvl < lvl) Py_RETURN_NONE; /* Don't bother parsing args */
 
        if (!PyArg_ParseTupleAndKeywords(args, kwds, "s|ii", (char **)((uintptr_t)kwlist),
                                         &msg, &type, &lvl)) Py_RETURN_NONE;
 
        fr_log(&default_log, type, __FILE__, __LINE__, "rlm_python (%s) - %s", inst->name, msg);
 
        Py_RETURN_NONE;
}
 
static int py_freeradius_state_init(PyObject *self, UNUSED PyObject *args, UNUSED PyObject *kwds)
{
        py_freeradius_state_t   *our_self = (py_freeradius_state_t *)self;
        rlm_python_t const      *inst;
 
        fr_assert(current_inst);
        our_self->t = current_t ? talloc_get_type_abort(current_t, rlm_python_thread_t) : NULL; /*  May be NULL if this is the first interpreter */
        our_self->inst = inst = current_t ? current_t->inst : current_inst;
        DEBUG3("Populating __State data with %p/%p", our_self->inst, our_self->t);
 
        return 0;
}
 
/** Returns a specific instance of freeradius.Pair
 *
 * Called when a numeric index is used on a PairGroup or PairValue as part of an object getter
 */
static PyObject *py_freeradius_attribute_instance(PyObject *self, PyObject *attr)
{
        long                    idx;
        py_freeradius_pair_t    *pair, *init_pair = (py_freeradius_pair_t *)self;
 
        if (!PyLong_CheckExact(attr)) Py_RETURN_NONE;
        idx = PyLong_AsLong(attr);
 
        if (idx < 0) {
                PyErr_SetString(PyExc_AttributeError, "Cannot use negative attribute instance values");
                return NULL;
        }
        if (idx == 0) return self;
 
        if (fr_type_is_leaf(init_pair->da->type)) {
                pair = PyObject_New(py_freeradius_pair_t, (PyTypeObject *)&py_freeradius_value_pair_def);
 
        } else if (fr_type_is_struct(init_pair->da->type)) {
                pair = PyObject_New(py_freeradius_pair_t, (PyTypeObject *)&py_freeradius_grouping_pair_def);
        } else {
                PyErr_SetString(PyExc_AttributeError, "Unsupported data type");
                return NULL;
        }
        if (!pair) {
                PyErr_SetString(PyExc_MemoryError, "Failed to allocate PyObject");
                return NULL;
        }
        pair->parent = init_pair->parent;
        Py_INCREF(init_pair->parent);
        pair->da = init_pair->da;
        pair->idx = idx;
        if (init_pair->vp) pair->vp = fr_pair_find_by_da_idx(fr_pair_parent_list(init_pair->vp), pair->da, (unsigned int)idx);
        return (PyObject *)pair;
}
 
/** Returns a freeradius.Pair
 *
 * Called when pair["attr"] or pair["attr"][n] is accessed.
 * When pair["attr"] is accessed, `self` is `pair` - which is the list or a pair group object
 * When pair["attr"][n] is accessed, `self` is pair["attr"]
 *
 * Either a group object or pair object will be returned.
 */
static PyObject *py_freeradius_pair_map_subscript(PyObject *self, PyObject *attr)
{
        py_freeradius_pair_t    *our_self = (py_freeradius_pair_t *)self;
        char const              *attr_name;
        ssize_t                 len;
        request_t               *request = rlm_python_get_request();
        py_freeradius_pair_t    *pair;
        fr_dict_attr_t const    *da;
        fr_pair_list_t          *list = NULL;
 
        /*
         *      If we have a numeric subscript, find the nth instance of the pair.
         */
        if (PyLong_CheckExact(attr)) return py_freeradius_attribute_instance(self, attr);
 
        if (!PyUnicode_CheckExact(attr)) {
                PyErr_Format(PyExc_AttributeError, "Invalid type '%s' for map attribute",
                          ((PyTypeObject *)PyObject_Type(attr))->tp_name);
                return NULL;
        }
        attr_name = PyUnicode_AsUTF8AndSize(attr, &len);
 
        if (PyObject_IsInstance(self, (PyObject *)&py_freeradius_pair_list_def)) {
                fr_dict_attr_search_by_name_substr(NULL, &da, request->proto_dict, &FR_SBUFF_IN(attr_name, len),
                                                   NULL, true, false);
        } else {
                fr_dict_attr_by_name_substr(NULL, &da, our_self->da, &FR_SBUFF_IN(attr_name, len), NULL);
        }
        if (our_self->vp) list = &our_self->vp->vp_group;
 
        if (!da) {
                PyErr_Format(PyExc_AttributeError, "Invalid attribute name '%.*s'", (int)len, attr_name);
                return NULL;
        }
 
        if (fr_type_is_leaf(da->type)) {
                pair = PyObject_New(py_freeradius_pair_t, (PyTypeObject *)&py_freeradius_value_pair_def);
        } else if (fr_type_is_structural(da->type)) {
                pair = PyObject_New(py_freeradius_pair_t, (PyTypeObject *)&py_freeradius_grouping_pair_def);
        } else {
                PyErr_SetString(PyExc_AttributeError, "Unsupported data type");
                return NULL;
        }
        if (!pair) {
                PyErr_SetString(PyExc_MemoryError, "Failed to allocate PyObject");
                return NULL;
        }
 
        pair->parent = self;
        Py_INCREF(self);
        pair->da = da;
        pair->vp = list ? fr_pair_find_by_da(list, NULL, da) : NULL;
        pair->idx = 0;
 
        return (PyObject *)pair;
}
 
/** Build out missing parent pairs when a leaf node is assigned a value.
 *
 */
static fr_pair_t *py_freeradius_build_parents(PyObject *obj)
{
        py_freeradius_pair_t    *obj_pair = (py_freeradius_pair_t *)obj;
        fr_pair_t               *parent = ((py_freeradius_pair_t *)obj_pair->parent)->vp;
 
        if (!parent) {
                parent = py_freeradius_build_parents(obj_pair->parent);
                if (!parent) return NULL;
        }
 
        /*
         *      Asked to populate foo[n] - check that we have n instances already
         */
        if (obj_pair->idx > 0) {
                unsigned int count = fr_pair_count_by_da(&parent->vp_group, obj_pair->da);
                if (count < obj_pair->idx) {
                        PyErr_Format(PyExc_AttributeError, "Attempt to set instance %d when only %d exist", obj_pair->idx, count);
                        return NULL;
                }
        }
        fr_pair_append_by_da(parent, &obj_pair->vp, &parent->vp_group, obj_pair->da);
 
        return obj_pair->vp;
}
 
/**  Set the value of a pair
 *
 * Called with two Python syntaxes
 *
 *  - request['foo'] = 'baa'
 *    `self` will be the parent object - either the list or parent structural object.
 *    `attr` is the value in [].
 *    `value` is what we want to set the pair to.
 *
 *   - request['foo'][n] = 'baa'
 *     `self` will be the first instance of the attribute `foo`
 *     `attr` will be the instance number
 *     `value` is what we want to set the pair to.
 *
 * We expect `value` to be a UTF8 string object.
 *
 * Due to Python "magic" this is also called when `del request['foo']` happens - only with
 * value as NULL.
 */
static int py_freeradius_pair_map_set(PyObject* self, PyObject* attr, PyObject* value)
{
        fr_pair_list_t          *list = NULL;
        request_t               *request = rlm_python_get_request();
        py_freeradius_pair_t    *our_self = (py_freeradius_pair_t *)self;
        fr_pair_t               *vp = NULL;
        char const              *vstr;
        ssize_t                 vlen;
        bool                    del = (value ? false : true);
 
        if (value && !PyUnicode_CheckExact(value)) {
                PyErr_Format(PyExc_AttributeError, "Invalid value type '%s'", ((PyTypeObject *)PyObject_Type(value))->tp_name);
                return -1;
        }
 
        /*
         *      list['attr'] = 'value'
         *      Look up DA represented by 'attr' and find pair or create pair to update
         */
        if (PyUnicode_CheckExact(attr)) {
                char const              *attr_name;
                ssize_t                 len;
                fr_dict_attr_t const    *da = NULL;
 
                attr_name = PyUnicode_AsUTF8AndSize(attr, &len);
 
                if (PyObject_IsInstance(self, (PyObject *)&py_freeradius_pair_list_def)) {
                        fr_dict_attr_search_by_name_substr(NULL, &da, request->proto_dict, &FR_SBUFF_IN(attr_name, len),
                                                           NULL, true, false);
                } else {
                        fr_dict_attr_by_name_substr(NULL, &da, our_self->da, &FR_SBUFF_IN(attr_name, len), NULL);
                }
 
                if (!da) {
                        PyErr_Format(PyExc_AttributeError, "Invalid attribute name %.*s", (int)len, attr_name);
                        return -1;
                }
 
                // `self` is the parent of the pair we're building - so we build parents to that point.
                if (!our_self->vp) {
                        if (del) return 0;      // If we're deleting then no need to build parents.
                        our_self->vp = py_freeradius_build_parents(self);
                }
                if (!our_self->vp) return -1;
 
                list = &our_self->vp->vp_group;
 
                vp = fr_pair_find_by_da(list, NULL, da);
                if (del) goto del;
 
                if (!vp) {
                        if (fr_pair_append_by_da(fr_pair_list_parent(list), &vp, list, da) < 0) {
                                PyErr_Format(PyExc_MemoryError, "Failed to add attribute %s", da->name);
                                return -1;
                        }
                } else {
                        fr_value_box_clear_value(&vp->data);
                }
 
        /*
         *      list['attr'][n] = 'value'
         *      Look for instance n, creating if necessary
         */
        } else if (PyLong_CheckExact(attr)) {
                long                    idx = PyLong_AsLong(attr);
                py_freeradius_pair_t    *parent = (py_freeradius_pair_t *)our_self->parent;
 
                if (idx < 0) {
                        PyErr_SetString(PyExc_AttributeError, "Cannot use negative attribute instance values");
                        return -1;
                }
 
                if (!parent->vp) {
                        if (del) return 0;
                        parent->vp = py_freeradius_build_parents(our_self->parent);
                }
                if (!parent->vp) return -1;
 
                list = &parent->vp->vp_group;
 
                if (idx == 0) {
                        if (!our_self->vp) {
                                if (fr_pair_append_by_da(fr_pair_list_parent(list), &our_self->vp, list, our_self->da) < 0) {
                                        PyErr_Format(PyExc_MemoryError, "Failed to add attribute %s", our_self->da->name);
                                        return -1;
                                }
                        } else {
                                fr_value_box_clear_value(&our_self->vp->data);
                        }
                        vp = our_self->vp;
                        if (del) goto del;
                } else {
                        vp = fr_pair_find_by_da_idx(list, our_self->da, idx);
                        if (del) goto del;
                        if (!vp) {
                                unsigned int    count = fr_pair_count_by_da(list, our_self->da);
                                if (count < idx) {
                                        PyErr_Format(PyExc_AttributeError, "Attempt to set instance %ld when only %d exist", idx, count);
                                        return -1;
                                }
                                if (fr_pair_append_by_da(fr_pair_list_parent(list), &vp, list, our_self->da) < 0) {
                                        PyErr_Format(PyExc_MemoryError, "Failed to add attribute %s", our_self->da->name);
                                        return -1;
                                }
                        }
                }
        } else {
                PyErr_Format(PyExc_AttributeError, "Invalid object type '%s'", ((PyTypeObject *)PyObject_Type(attr))->tp_name);
                return -1;
        }
 
        fr_assert(fr_type_is_leaf(vp->da->type));
 
        vstr = PyUnicode_AsUTF8AndSize(value, &vlen);
 
        if (fr_pair_value_from_str(vp, vstr, vlen, NULL, false) < 0) {
                PyErr_Format(PyExc_AttributeError, "Failed setting '%s' = '%.*s", vp->da->name, (int)vlen, vstr);
                fr_pair_delete(list, vp);
                return -1;
        }
 
        RDEBUG2("set %pP", vp);
        return 0;
 
del:
        if (vp) {
                RDEBUG2("delete %pP", vp);
                fr_pair_delete(list, vp);
        }
        return 0;
}
 
/** Return a native Python object of the appropriate type for leaf pair objects
 *
 * Accessed as `request['attr'].value`
 *
 * `self` is the Python leaf pair object
 */
static PyObject *py_freeradius_pair_getvalue(PyObject *self, UNUSED void *closure)
{
        py_freeradius_pair_t    *own_self = (py_freeradius_pair_t *)self;
        PyObject                *value = NULL;
        fr_pair_t               *vp = own_self->vp;
 
        if (!vp) Py_RETURN_NONE;
 
        switch(vp->vp_type) {
        case FR_TYPE_STRING:
                value = PyUnicode_FromStringAndSize(vp->vp_strvalue, vp->vp_length);
                break;
 
        case FR_TYPE_OCTETS:
                value = PyBytes_FromStringAndSize((char const *)vp->vp_octets, vp->vp_length);
                break;
 
        case FR_TYPE_BOOL:
                value = PyBool_FromLong(vp->vp_bool);
                break;
 
        case FR_TYPE_UINT8:
                value = PyLong_FromUnsignedLong(vp->vp_uint8);
                break;
 
        case FR_TYPE_UINT16:
                value = PyLong_FromUnsignedLong(vp->vp_uint16);
                break;
 
        case FR_TYPE_UINT32:
                value = PyLong_FromUnsignedLong(vp->vp_uint32);
                break;
 
        case FR_TYPE_UINT64:
                value = PyLong_FromUnsignedLongLong(vp->vp_uint64);
                break;
 
        case FR_TYPE_INT8:
                value = PyLong_FromLong(vp->vp_int8);
                break;
 
        case FR_TYPE_INT16:
                value = PyLong_FromLong(vp->vp_int16);
                break;
 
        case FR_TYPE_INT32:
                value = PyLong_FromLong(vp->vp_int32);
                break;
 
        case FR_TYPE_INT64:
                value = PyLong_FromLongLong(vp->vp_int64);
                break;
 
        case FR_TYPE_FLOAT32:
                value = PyFloat_FromDouble((double) vp->vp_float32);
                break;
 
        case FR_TYPE_FLOAT64:
                value = PyFloat_FromDouble(vp->vp_float64);
                break;
 
        case FR_TYPE_SIZE:
                value = PyLong_FromSize_t(vp->vp_size);
                break;
 
        case FR_TYPE_TIME_DELTA:
        case FR_TYPE_DATE:
        case FR_TYPE_IFID:
        case FR_TYPE_IPV6_ADDR:
        case FR_TYPE_IPV6_PREFIX:
        case FR_TYPE_IPV4_ADDR:
        case FR_TYPE_IPV4_PREFIX:
        case FR_TYPE_COMBO_IP_ADDR:
        case FR_TYPE_COMBO_IP_PREFIX:
        case FR_TYPE_ETHERNET:
        case FR_TYPE_ATTR:
        {
                ssize_t slen;
                char buffer[1024];
 
                slen = fr_value_box_print(&FR_SBUFF_OUT(buffer, sizeof(buffer)), &vp->data, NULL);
                if (slen < 0) {
                error:
                        PyErr_Format(PyExc_MemoryError, "Failed marshalling %s to Python value", vp->da->name);
                        return NULL;
                }
                value = PyUnicode_FromStringAndSize(buffer, (size_t)slen);
        }
                break;
 
        case FR_TYPE_NON_LEAF:
                fr_assert(0);
                break;
        }
 
        if (value == NULL) goto error;
 
        Py_INCREF(value);
        return value;
}
 
/** Use a native Python object of the appropriate type to set a leaf pair
 *
 * Using Python syntax `request['attr'].value = object` or `request['attr'][n].value`
 *
 * `self` is the Python object representing the leaf node pair
 */
static int py_freeradius_pair_setvalue(PyObject *self, PyObject *value, UNUSED void *closure)
{
        py_freeradius_pair_t    *own_self = (py_freeradius_pair_t *)self;
        fr_pair_t               *vp = own_self->vp;
 
        /*
         *      The pair doesn't exist yet - so create it
         */
        if (!vp) {
                py_freeradius_pair_t    *parent = (py_freeradius_pair_t *)own_self->parent;
                fr_pair_list_t          *list;
                unsigned int            count;
 
                if (!parent->vp) parent->vp = py_freeradius_build_parents(own_self->parent);
                if (!parent->vp) return -1;
 
                list = &parent->vp->vp_group;
                count = fr_pair_count_by_da(list, own_self->da);
                if (count < own_self->idx) {
                        PyErr_Format(PyExc_AttributeError, "Attempt to set instance %d when only %d exist", own_self->idx, count);
                        return -1;
                }
                fr_pair_append_by_da(fr_pair_list_parent(list), &vp, list, own_self->da);
                own_self->vp = vp;
        }
 
        switch (vp->da->type) {
        case FR_TYPE_STRING:
        {
                char const      *val;
                ssize_t         len;
                if (!PyUnicode_CheckExact(value)){
                wrong_type:
                        PyErr_Format(PyExc_AttributeError, "Incorrect Python type '%s' for attribute type '%s'",
                                     ((PyTypeObject *)PyObject_Type(value))->tp_name, fr_type_to_str(vp->da->type));
                        return -1;
                }
                val = PyUnicode_AsUTF8AndSize(value, &len);
                fr_value_box_clear_value(&vp->data);
                fr_value_box_bstrndup(vp, &vp->data, NULL, val, len, false);
        }
                break;
 
        case FR_TYPE_OCTETS:
        {
                uint8_t *val;
                ssize_t len;
                if (!PyObject_IsInstance(value, (PyObject *)&PyBytes_Type)) goto wrong_type;
                PyBytes_AsStringAndSize(value, (char **)&val, &len);
                fr_value_box_clear(&vp->data);
                fr_value_box_memdup(vp, &vp->data, NULL, val, len, false);
        }
                break;
 
        case FR_TYPE_BOOL:
        case FR_TYPE_UINT8:
        case FR_TYPE_UINT16:
        case FR_TYPE_UINT32:
        case FR_TYPE_UINT64:
        case FR_TYPE_INT8:
        case FR_TYPE_INT16:
        case FR_TYPE_INT32:
        case FR_TYPE_INT64:
        case FR_TYPE_SIZE:
        {
                long long val;
                if (!PyLong_CheckExact(value)) goto wrong_type;
                val = PyLong_AsLongLong(value);
 
                switch (vp->da->type) {
                case FR_TYPE_BOOL:
                        vp->vp_bool = (bool)val;
                        break;
                case FR_TYPE_UINT8:
                        vp->vp_uint8 = (uint8_t)val;
                        break;
                case FR_TYPE_UINT16:
                        vp->vp_uint16 = (uint16_t)val;
                        break;
                case FR_TYPE_UINT32:
                        vp->vp_uint32 = (uint32_t)val;
                        break;
                case FR_TYPE_UINT64:
                        vp->vp_uint64 = (uint64_t)val;
                        break;
                case FR_TYPE_INT8:
                        vp->vp_int8 = (int8_t)val;
                        break;
                case FR_TYPE_INT16:
                        vp->vp_int16 = (int16_t)val;
                        break;
                case FR_TYPE_INT32:
                        vp->vp_int32 = (int32_t)val;
                        break;
                case FR_TYPE_INT64:
                        vp->vp_int64 = (int64_t)val;
                        break;
                case FR_TYPE_SIZE:
                        vp->vp_size = (size_t)val;
                        break;
                default:
                        fr_assert(0);
                }
        }
                break;
 
        case FR_TYPE_FLOAT32:
        case FR_TYPE_FLOAT64:
        {
                double val;
                if (!PyFloat_CheckExact(value)) goto wrong_type;
                val = PyFloat_AsDouble(value);
 
                if (vp->da->type == FR_TYPE_FLOAT32) {
                        vp->vp_float32 = (float)val;
                } else {
                        vp->vp_float64 = val;
                }
        }
                break;
 
        case FR_TYPE_TIME_DELTA:
        case FR_TYPE_DATE:
        case FR_TYPE_IFID:
        case FR_TYPE_IPV6_ADDR:
        case FR_TYPE_IPV6_PREFIX:
        case FR_TYPE_IPV4_ADDR:
        case FR_TYPE_IPV4_PREFIX:
        case FR_TYPE_COMBO_IP_ADDR:
        case FR_TYPE_COMBO_IP_PREFIX:
        case FR_TYPE_ETHERNET:
        case FR_TYPE_ATTR:
        {
                char const      *val;
                ssize_t         len;
 
                if (!PyUnicode_CheckExact(value)) goto wrong_type;
 
                val = PyUnicode_AsUTF8AndSize(value, &len);
                if (fr_pair_value_from_str(vp, val, len, NULL, false) < 0) {
                        PyErr_Format(PyExc_AttributeError, "Failed parsing %.*s as %s", (int)len, val, fr_type_to_str(vp->da->type));
                        return -1;
                }
        }
                break;
 
        case FR_TYPE_NON_LEAF:
                fr_assert(0);
                break;
        }
 
        return 0;
}
 
/** Return the string representation of a leaf pair node
 *
 * Called when the attribute is accessed in print() or str() or selective other
 * magical Python contexts.
 */
static PyObject *py_freeradius_pair_str(PyObject *self) {
        py_freeradius_pair_t    *own_self = (py_freeradius_pair_t *)self;
        PyObject                *value = NULL;
        fr_pair_t               *vp = own_self->vp;
 
        if (!vp) return PyObject_Str(Py_None);
 
        switch(vp->vp_type) {
        case FR_TYPE_STRING:
                value = PyUnicode_FromStringAndSize(vp->vp_strvalue, vp->vp_length);
                break;
 
        case FR_TYPE_NON_LEAF:
                fr_assert(0);
                break;
 
        default:
        {
                ssize_t         slen;
                char            buffer[1024];
 
                slen = fr_value_box_print(&FR_SBUFF_OUT(buffer, sizeof(buffer)), &vp->data, NULL);
                if (slen < 0) {
                error:
                        PyErr_Format(PyExc_MemoryError, "Failed casting %s to Python string", vp->da->name);
                        return NULL;
                }
                value = PyUnicode_FromStringAndSize(buffer, (size_t)slen);
        }
                break;
        }
 
        if (value == NULL) goto error;
 
        return value;
}
 
/** Print out the current error
 *
 * Must be called with a valid thread state set
 */
static void python_error_log(rlm_python_t const *inst, request_t *request)
{
        PyObject *p_type = NULL, *p_value = NULL, *p_traceback = NULL, *p_str_1 = NULL, *p_str_2 = NULL;
 
        PyErr_Fetch(&p_type, &p_value, &p_traceback);
        PyErr_NormalizeException(&p_type, &p_value, &p_traceback);
        if (!p_type || !p_value) goto failed;
 
        if (((p_str_1 = PyObject_Str(p_type)) == NULL) || ((p_str_2 = PyObject_Str(p_value)) == NULL)) goto failed;
 
        ROPTIONAL(RERROR, ERROR, "%s (%s)", PyUnicode_AsUTF8(p_str_1), PyUnicode_AsUTF8(p_str_2));
 
        if (p_traceback != Py_None) {
                PyTracebackObject *ptb = (PyTracebackObject*)p_traceback;
                size_t fnum = 0;
 
                while (ptb != NULL) {
                        PyFrameObject *cur_frame = ptb->tb_frame;
#if PY_VERSION_HEX >= 0x030A0000
                        PyCodeObject *code = PyFrame_GetCode(cur_frame);
 
                        ROPTIONAL(RERROR, ERROR, "[%zu] %s:%d at %s()",
                                fnum,
                                PyUnicode_AsUTF8(code->co_filename),
                                PyFrame_GetLineNumber(cur_frame),
                                PyUnicode_AsUTF8(code->co_name)
                        );
                        Py_XDECREF(code);
#else
                        ROPTIONAL(RERROR, ERROR, "[%ld] %s:%d at %s()",
                                  fnum,
                                  PyUnicode_AsUTF8(cur_frame->f_code->co_filename),
                                  PyFrame_GetLineNumber(cur_frame),
                                  PyUnicode_AsUTF8(cur_frame->f_code->co_name)
                        );
#endif
 
                        ptb = ptb->tb_next;
                        fnum++;
                }
        }
 
failed:
        Py_XDECREF(p_str_1);
        Py_XDECREF(p_str_2);
        Py_XDECREF(p_type);
        Py_XDECREF(p_value);
        Py_XDECREF(p_traceback);
}
 
/** Create the Python object representing a pair list
 *
 */
static inline CC_HINT(always_inline) PyObject *pair_list_alloc(request_t *request, fr_dict_attr_t const *list)
{
        PyObject                *py_list;
        py_freeradius_pair_t    *our_list;
 
        /*
         *      When handing instantiate and detach, there is no request
         */
        if (!request) {
                Py_INCREF(Py_None);
                return Py_None;
        }
 
        py_list = PyObject_CallObject((PyObject *)&py_freeradius_pair_list_def, NULL);
        if (unlikely(!py_list)) return NULL;
 
        our_list = (py_freeradius_pair_t *)py_list;
        our_list->da = list;
        our_list->vp = fr_pair_list_parent(tmpl_list_head(request, list));
        our_list->parent = NULL;
        our_list->idx = 0;
        return py_list;
}
 
/** Convert the integer which a Python function returned to an rcode
 *
 * @param[in] inst      of rlm_python.
 * @param[in] value     which the Python function returned.
 * @return
 *      - The rcode.
 *      - RLM_MODULE_FAIL if the integer is not an rcode which a module may return.
 */
static rlm_rcode_t python_rcode_from_long(rlm_python_t const *inst, long value)
{
        if (!RLM_MODULE_RCODE_VALID(value)) {
                ERROR("Python function returned %ld, which is not a valid return code", value);
                return RLM_MODULE_FAIL;
        }
 
        return (rlm_rcode_t) value;
}
 
static unlang_action_t do_python_single(unlang_result_t *p_result, module_ctx_t const *mctx,
                                        request_t *request, PyObject *p_func, char const *funcname)
{
        rlm_rcode_t             rcode = RLM_MODULE_OK;
        rlm_python_t const      *inst = talloc_get_type_abort(mctx->mi->data, rlm_python_t);
 
        PyObject                *p_ret = NULL;
        PyObject                *py_request;
        py_freeradius_request_t *our_request;
 
        /*
         *      Instantiate the request
         */
        py_request = PyObject_CallObject((PyObject *)&py_freeradius_request_def, NULL);
        if (unlikely(!py_request)) {
                python_error_log(inst, request);
                RETURN_UNLANG_FAIL;
        }
 
        our_request = (py_freeradius_request_t *)py_request;
        rlm_python_set_request(request);
 
        /*
         *      Create the list roots
         */
        our_request->request = pair_list_alloc(request, request_attr_request);
        if (unlikely(!our_request->request)) {
        req_error:
                Py_DECREF(py_request);
                python_error_log(inst, request);
                RETURN_UNLANG_FAIL;
        }
 
        our_request->reply = pair_list_alloc(request, request_attr_reply);
        if (unlikely(!our_request->reply)) goto req_error;
 
        our_request->control = pair_list_alloc(request, request_attr_control);
        if (unlikely(!our_request->control)) goto req_error;
 
        our_request->state = pair_list_alloc(request, request_attr_state);
        if (unlikely(!our_request->state)) goto req_error;
 
        /* Call Python function. */
        p_ret = PyObject_CallFunctionObjArgs(p_func, py_request, NULL);
        if (!p_ret) {
                RERROR("Python function returned no value");
                rcode = RLM_MODULE_FAIL;
                goto finish;
        }
 
        if (!request) {
                // check return code at module instantiation time
                if (PyNumber_Check(p_ret)) rcode = python_rcode_from_long(inst, PyLong_AsLong(p_ret));
                goto finish;
        }
 
        /*
         *  The function is expected to either return a return value
         *  or None, which results in the default return value.
         */
        if (PyNumber_Check(p_ret)) {
                /* Just an integer */
                rcode = python_rcode_from_long(inst, PyLong_AsLong(p_ret));
 
        } else if (p_ret == Py_None) {
                /* returned 'None', return value defaults to "OK, continue." */
                rcode = RLM_MODULE_OK;
        } else {
                /* Not tuple or None */
                ERROR("%s - Function did not return a tuple or None", funcname);
                rcode = RLM_MODULE_FAIL;
                goto finish;
        }
 
finish:
        rlm_python_set_request(NULL);
 
        if (rcode == RLM_MODULE_FAIL) python_error_log(inst, request);
        Py_XDECREF(p_ret);
        Py_XDECREF(py_request);
 
        RETURN_UNLANG_RCODE(rcode);
}
 
/** Thread safe call to a python function
 *
 * Will swap in thread state specific to module/thread.
 */
static unlang_action_t mod_python(unlang_result_t *p_result, module_ctx_t const *mctx, request_t *request)
{
        rlm_python_thread_t     *t = talloc_get_type_abort(mctx->thread, rlm_python_thread_t);
        python_call_env_t       *func = talloc_get_type_abort(mctx->env_data, python_call_env_t);
 
        /*
         *      It's a NOOP if the function wasn't defined
         */
        if (!func->func->function) RETURN_UNLANG_NOOP;
 
        RDEBUG3("Using thread state %p/%p", mctx->mi->data, t->state);
 
        PyEval_RestoreThread(t->state); /* Swap in our local thread state */
        do_python_single(p_result, mctx, request, func->func->function, func->func->function_name);
        (void)fr_cond_assert(PyEval_SaveThread() == t->state);
 
        return UNLANG_ACTION_CALCULATE_RESULT;
}
 
static void python_obj_destroy(PyObject **ob)
{
        if (*ob != NULL) {
                Py_DECREF(*ob);
                *ob = NULL;
        }
}
 
static void python_function_destroy(python_func_def_t *def)
{
        python_obj_destroy(&def->function);
        python_obj_destroy(&def->module);
}
 
/** Import a user module and load a function from it
 *
 */
static int python_function_load(module_inst_ctx_t const *mctx, python_func_def_t *def)
{
        rlm_python_t const      *inst = talloc_get_type_abort(mctx->mi->data, rlm_python_t);
        char const *funcname = "python_function_load";
 
        if (def->module_name == NULL || (def->function_name == NULL && def->name1 == NULL)) return 0;
 
        LSAN_DISABLE(def->module = PyImport_ImportModule(def->module_name));
        if (!def->module) {
                ERROR("%s - Module '%s' load failed", funcname, def->module_name);
        error:
                python_error_log(inst, NULL);
                Py_XDECREF(def->function);
                def->function = NULL;
                Py_XDECREF(def->module);
                def->module = NULL;
 
                return -1;
        }
 
        /*
         *      Calls found by call_env parsing will have name1 set
         *      If name2 is set first look for <name1>_<name2> and fall back to <name1>
         */
        if (!def->function_name) def->function_name = def->name2 ? talloc_asprintf(def, "%s_%s", def->name1, def->name2) : def->name1;
 
        def->function = PyObject_GetAttrString(def->module, def->function_name);
        if (!def->function && def->name2) {
                PyErr_Clear();  // Since we're checking for another function, clear any errors.
                talloc_const_free(def->function_name);
                def->function_name = def->name1;
                def->function = PyObject_GetAttrString(def->module, def->function_name);
        }
        if (!def->function) {
                ERROR("%s - Function '%s.%s' is not found", funcname, def->module_name, def->function_name);
                goto error;
        }
 
        if (!PyCallable_Check(def->function)) {
                ERROR("%s - Function '%s.%s' is not callable", funcname, def->module_name, def->function_name);
                goto error;
        }
 
        DEBUG2("Loaded function '%s.%s'", def->module_name, def->function_name);
        return 0;
}
 
/*
 *      Parse a configuration section, and populate a dict.
 *      This function is recursively called (allows to have nested dicts.)
 */
static int python_parse_config(rlm_python_t const *inst, CONF_SECTION *cs, int lvl, PyObject *dict)
{
        int             indent_section = (lvl * 4);
        int             indent_item = (lvl + 1) * 4;
        int             ret = 0;
        CONF_ITEM       *ci = NULL;
 
        if (!cs || !dict) return -1;
 
        DEBUG("%*s%s {", indent_section, " ", cf_section_name1(cs));
 
        while ((ci = cf_item_next(cs, ci))) {
                /*
                 *  This is a section.
                 *  Create a new dict, store it in current dict,
                 *  Then recursively call python_parse_config with this section and the new dict.
                 */
                if (cf_item_is_section(ci)) {
                        CONF_SECTION    *sub_cs = cf_item_to_section(ci);
                        char const      *key = cf_section_name1(sub_cs); /* dict key */
                        PyObject        *sub_dict, *p_key;
 
                        p_key = PyUnicode_FromString(key);
                        if (!p_key) {
                                ERROR("Failed converting config key \"%s\" to python string", key);
                                return -1;
                        }
 
                        if (PyDict_Contains(dict, p_key)) {
                                WARN("Ignoring duplicate config section '%s'", key);
                                Py_DECREF(p_key);
                                continue;
                        }
 
                        MEM(sub_dict = PyDict_New());
                        (void)PyDict_SetItem(dict, p_key, sub_dict);
                        Py_DECREF(p_key);
                        Py_DECREF(sub_dict);
 
                        ret = python_parse_config(inst, sub_cs, lvl + 1, sub_dict);
                        if (ret < 0) break;
                } else if (cf_item_is_pair(ci)) {
                        CONF_PAIR       *cp = cf_item_to_pair(ci);
                        char const      *key = cf_pair_attr(cp); /* dict key */
                        char const      *value = cf_pair_value(cp); /* dict value */
                        PyObject        *p_key, *p_value;
 
                        if (!value) {
                                WARN("Skipping \"%s\" as it has no value", key);
                                continue;
                        }
 
                        p_key = PyUnicode_FromString(key);
                        p_value = PyUnicode_FromString(value);
                        if (!p_key) {
                                ERROR("Failed converting config key \"%s\" to python string", key);
                                Py_XDECREF(p_value);
                                return -1;
                        }
                        if (!p_value) {
                                ERROR("Failed converting config value \"%s\" to python string", value);
                                Py_DECREF(p_key);
                                return -1;
                        }
 
                        /*
                         *  This is an item.
                         *  Store item attr / value in current dict.
                         */
                        if (PyDict_Contains(dict, p_key)) {
                                WARN("Ignoring duplicate config item '%s'", key);
                                Py_DECREF(p_key);
                                Py_DECREF(p_value);
                                continue;
                        }
 
                        (void)PyDict_SetItem(dict, p_key, p_value);
                        Py_DECREF(p_key);
                        Py_DECREF(p_value);
 
                        DEBUG("%*s%s = \"%s\"", indent_item, " ", key, value);
                }
        }
 
        DEBUG("%*s}", indent_section, " ");
 
        return ret;
}
 
/** Make the current instance's config available within the module we're initialising
 *
 */
static int python_module_import_config(rlm_python_t *inst, CONF_SECTION *conf, PyObject *module)
{
        CONF_SECTION *cs;
 
        /*
         *      Convert a FreeRADIUS config structure into a python
         *      dictionary.
         */
        inst->pythonconf_dict = PyDict_New();
        if (!inst->pythonconf_dict) {
                ERROR("Unable to create python dict for config");
        error:
                Py_XDECREF(inst->pythonconf_dict);
                inst->pythonconf_dict = NULL;
                python_error_log(inst, NULL);
                return -1;
        }
 
        cs = cf_section_find(conf, "config", NULL);
        if (cs) {
                DEBUG("Inserting \"config\" section into python environment as radiusd.config");
                if (python_parse_config(inst, cs, 0, inst->pythonconf_dict) < 0) goto error;
        }
 
        /*
         *      Add module configuration as a dict
         */
        if (PyModule_AddObject(module, "config", inst->pythonconf_dict) < 0) goto error;
 
        return 0;
}
 
/** Import integer constants into the module we're initialising
 *
 */
static int python_module_import_constants(rlm_python_t const *inst, PyObject *module)
{
        size_t i;
 
        for (i = 0; freeradius_constants[i].name; i++) {
                if ((PyModule_AddIntConstant(module, freeradius_constants[i].name, freeradius_constants[i].value)) < 0) {
                        ERROR("Failed adding constant to module");
                        python_error_log(inst, NULL);
                        return -1;
                }
        }
 
        return 0;
}
 
/*
 *      Python 3 interpreter initialisation and destruction
 */
static PyObject *python_module_init(void)
{
        PyObject                *module;
        PyObject                *p_state;
        static pthread_mutex_t  init_lock = PTHREAD_MUTEX_INITIALIZER;
        static bool             type_ready = false;
 
        fr_assert(current_inst);
 
        /*
         *      Only allow one thread at a time to do the module init.  This is
         *      out of an abundance of caution as it's unclear whether the
         *      reference counts on the various objects are thread safe.
         */
        pthread_mutex_lock(&init_lock);
 
        /*
         *      The type definitions are global, so we only need to call the
         *      init functions the first pass through.
        */
 
        if (!type_ready) {
                /*
                 *      We need to initialise the definitions first
                 *      this fills in any fields we didn't explicitly
                 *      specify, and gets the structures ready for
                 *      use by the python interpreter.
                 */
                if (PyType_Ready(&py_freeradius_pair_def) < 0) {
                error:
                        pthread_mutex_unlock(&init_lock);
                        python_error_log(current_inst, NULL);
                        Py_RETURN_NONE;
                }
 
                if (PyType_Ready(&py_freeradius_value_pair_def) < 0) goto error;
 
                if (PyType_Ready(&py_freeradius_grouping_pair_def) < 0) goto error;
 
                if (PyType_Ready(&py_freeradius_pair_list_def) < 0) goto error;
 
                if (PyType_Ready(&py_freeradius_request_def) < 0) goto error;
 
                if (PyType_Ready(&py_freeradius_state_def) < 0) goto error;
 
                type_ready = true;
        }
 
        /*
         *      The module is per-interpreter
         */
        module = PyModule_Create(&py_freeradius_def);
        if (!module) {
                python_error_log(current_inst, NULL);
                goto error;
        }
 
        /*
         *      PyModule_AddObject steals ref on success, we we
         *      INCREF here to give it something to steal, else
         *      on free the refcount would go negative.
         *
         *      Note here we're creating a new instance of an
         *      object, not adding the object definition itself
         *      as there's no reason that a python script would
         *      ever need to create an instance object.
         *
         *      The instantiation function associated with the
         *      the __State object takes care of populating the
         *      instance data from globals and thread-specific
         *      variables.
         */
        p_state = PyObject_CallObject((PyObject *)&py_freeradius_state_def, NULL);
        if (unlikely(!p_state)) {
                Py_DECREF(module);
                goto error;
        }
        Py_INCREF(&py_freeradius_state_def);
 
        if (PyModule_AddObject(module, "__State", p_state) < 0) {
                Py_DECREF(p_state);
                Py_DECREF(&py_freeradius_state_def);
                Py_DECREF(module);
                goto error;
        }
 
        /*
         *      For "Pair" we're inserting an object definition
         *      as opposed to the object instance we inserted
         *      for inst.
         */
        Py_INCREF(&py_freeradius_pair_def);
        if (PyModule_AddObject(module, "Pair", (PyObject *)&py_freeradius_pair_def) < 0) {
                Py_DECREF(&py_freeradius_pair_def);
                Py_DECREF(module);
                goto error;
        }
        pthread_mutex_unlock(&init_lock);
 
        return module;
}
 
static int python_interpreter_init(module_inst_ctx_t const *mctx)
{
        rlm_python_t    *inst = talloc_get_type_abort(mctx->mi->data, rlm_python_t);
        CONF_SECTION    *conf = mctx->mi->conf;
        PyObject        *module;
 
        /*
         *      python_module_init() takes no arguments, so the
         *      current_inst global passes the module instance to
         *      python_module_init() when the interpreter
         *      initialisation calls python_module_init().
         */
        current_inst = inst;
 
        PyEval_RestoreThread(global_interpreter);
        LSAN_DISABLE(inst->interpreter = Py_NewInterpreter());
        if (!inst->interpreter) {
                ERROR("Failed creating new interpreter");
                return -1;
        }
        DEBUG3("Created new interpreter %p", inst->interpreter);
        PyEval_SaveThread();            /* Unlock GIL */
 
        PyEval_RestoreThread(inst->interpreter);
 
        /*
         *      Import the radiusd module into this python
         *      environment.  Each interpreter gets its
         *      own copy which it can mutate as much as
         *      it wants.
         */
        module = PyImport_ImportModule("freeradius");
        if (!module) {
                ERROR("Failed importing \"freeradius\" module into interpreter %p", inst->interpreter);
                return -1;
        }
        if ((python_module_import_config(inst, conf, module) < 0) ||
            (python_module_import_constants(inst, module) < 0)) {
                Py_DECREF(module);
                return -1;
        }
        inst->module = module;
        PyEval_SaveThread();
 
        return 0;
}
 
static void python_interpreter_free(rlm_python_t *inst, PyThreadState *interp)
{
        PyEval_RestoreThread(interp);   /* Switches thread state and locks GIL */
 
        /*
         *      We incremented the reference count earlier
         *      during module initialisation.
         */
        Py_XDECREF(inst->module);
 
        Py_EndInterpreter(interp);      /* Destroys interpreter (GIL still locked) - sets thread state to NULL */
        PyThreadState_Swap(global_interpreter); /* Get a none-null thread state */
        PyEval_SaveThread();            /* Unlock GIL */
}
 
/*
 *      Do any per-module initialization that is separate to each
 *      configured instance of the module.  e.g. set up connections
 *      to external databases, read configuration files, set up
 *      dictionary entries, etc.
 *
 *      If configuration information is given in the config section
 *      that must be referenced in later calls, store a handle to it
 *      in *instance otherwise put a null pointer there.
 *
 */
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        rlm_python_t            *inst = talloc_get_type_abort(mctx->mi->data, rlm_python_t);
        python_func_def_t       *func = NULL;
        fr_rb_iter_inorder_t    iter;
        CONF_PAIR               *cp;
        char                    *pair_name;
 
        if (inst->interpreter) return 0;
        if (python_interpreter_init(mctx) < 0) return -1;
        inst->name = mctx->mi->name;
        if (!inst->funcs_init) fr_rb_inline_init(&inst->funcs, python_func_def_t, node, python_func_def_cmp, NULL);
        /*
         *      Switch to our module specific interpreter
         */
        PyEval_RestoreThread(inst->interpreter);
 
        /*
         *      Process the various sections
         */
#define PYTHON_FUNC_LOAD(_x) if (python_function_load(mctx, &inst->_x) < 0) goto error
        PYTHON_FUNC_LOAD(instantiate);
        PYTHON_FUNC_LOAD(detach);
 
        /*
         *      Load all the Python functions found by the call_env parser.
         */
        for (func = fr_rb_iter_init_inorder(&inst->funcs, &iter);
             func != NULL;
             func = fr_rb_iter_next_inorder(&inst->funcs, &iter)) {
                /*
                 *      Check for mod_<name1>_<name2> or mod_<name1> config pairs.
                 *      If neither exist, fall back to default Python module.
                 */
                if (func->name2) {
                        pair_name = talloc_asprintf(func, "mod_%s_%s", func->name1, func->name2);
                        cp = cf_pair_find(mctx->mi->conf, pair_name);
                        talloc_free(pair_name);
                        if (cp) goto found_mod;
                }
                pair_name = talloc_asprintf(func, "mod_%s", func->name1);
                cp = cf_pair_find(mctx->mi->conf, pair_name);
                talloc_free(pair_name);
        found_mod:
                func->module_name = cp ? cf_pair_value(cp) : inst->def_module_name;
 
                /*
                 *      Check for func_<name1>_<name2> or func_<name1> function overrides.
                 *      Checks for Python functions <name1>_<name2> and <name1> are done
                 *      in python_function_load.
                 */
                if (func->name2) {
                        pair_name = talloc_asprintf(func, "func_%s_%s", func->name1, func->name2);
                        cp = cf_pair_find(mctx->mi->conf, pair_name);
                        talloc_free(pair_name);
                        if (cp) goto found_func;
                }
                pair_name = talloc_asprintf(func, "func_%s", func->name1);
                cp = cf_pair_find(mctx->mi->conf, pair_name);
                talloc_free(pair_name);
        found_func:
                if (cp) func->function_name = cf_pair_value(cp);
 
                if (python_function_load(mctx, func) < 0) goto error;
        }
 
        /*
         *      Call the instantiate function.
         */
        if (inst->instantiate.function) {
                unlang_result_t result;
 
                do_python_single(&result, MODULE_CTX_FROM_INST(mctx), NULL, inst->instantiate.function, "instantiate");
                switch (result.rcode) {
                case RLM_MODULE_FAIL:
                case RLM_MODULE_REJECT:
                error:
                        fr_cond_assert(PyEval_SaveThread() == inst->interpreter);
                        python_interpreter_free(inst, inst->interpreter);
                        return -1;
 
                default:
                        break;
                }
        }
 
        /*
         *      Switch back to the global interpreter
         */
        if (!fr_cond_assert(PyEval_SaveThread() == inst->interpreter)) goto error;
 
        return 0;
}
 
static int mod_detach(module_detach_ctx_t const *mctx)
{
        rlm_python_t            *inst = talloc_get_type_abort(mctx->mi->data, rlm_python_t);
        python_func_def_t       *func = NULL;
        fr_rb_iter_inorder_t    iter;
 
        /*
         *      If we don't have a interpreter
         *      we didn't get far enough into
         *      instantiation to generate things
         *      we need to clean up...
         */
        if (!inst->interpreter) return 0;
 
        /*
         *      Call module destructor
         */
        PyEval_RestoreThread(inst->interpreter);
 
        /*
         *      We don't care if this fails.
         */
        if (inst->detach.function) {
                unlang_result_t result;
 
                (void)do_python_single(&result, MODULE_CTX_FROM_INST(mctx), NULL, inst->detach.function, "detach");
        }
 
#define PYTHON_FUNC_DESTROY(_x) python_function_destroy(&inst->_x)
        PYTHON_FUNC_DESTROY(instantiate);
        PYTHON_FUNC_DESTROY(detach);
 
        for (func = fr_rb_iter_init_inorder(&inst->funcs, &iter);
             func != NULL;
             func = fr_rb_iter_next_inorder(&inst->funcs, &iter)) {
                python_function_destroy(func);
        }
 
        PyEval_SaveThread();
 
        /*
         *      Free the module specific interpreter
         */
        python_interpreter_free(inst, inst->interpreter);
 
        return 0;
}
 
static int mod_thread_instantiate(module_thread_inst_ctx_t const *mctx)
{
        rlm_python_t            *inst = talloc_get_type_abort(mctx->mi->data, rlm_python_t);
        rlm_python_thread_t     *t = talloc_get_type_abort(mctx->thread, rlm_python_thread_t);
 
        PyThreadState           *t_state;
        PyObject                *t_dict;
        PyObject                *p_state;
 
        current_t = t;
 
        t->inst = inst;
        t_state = PyThreadState_New(inst->interpreter->interp);
        if (!t_state) {
                ERROR("Failed initialising local PyThreadState");
                return -1;
        }
 
        PyEval_RestoreThread(t_state);  /* Switches thread state and locks GIL */
        t_dict = PyThreadState_GetDict();
        if (unlikely(!t_dict)) {
                ERROR("Failed getting PyThreadState dictionary");
        error:
                PyEval_SaveThread();                    /* Unlock GIL */
                PyThreadState_Delete(t_state);
 
                return -1;
        }
 
        /*
         *      Instantiate a new instance object which captures
         *      the global and thread instances, and associates
         *      them with the thread.
         */
        p_state = PyObject_CallObject((PyObject *)&py_freeradius_state_def, NULL);
        if (unlikely(!p_state)) {
                ERROR("Failed instantiating module instance information object");
                goto error;
        }
 
        if (unlikely(PyDict_SetItemString(t_dict, "__State", p_state) < 0)) {
                ERROR("Failed setting module instance information in thread dict");
                goto error;
        }
 
        DEBUG3("Initialised PyThreadState %p", t_state);
        t->state = t_state;
        PyEval_SaveThread();                            /* Unlock GIL */
 
        return 0;
}
 
static int mod_thread_detach(module_thread_inst_ctx_t const *mctx)
{
        rlm_python_thread_t     *t = talloc_get_type_abort(mctx->thread, rlm_python_thread_t);
 
        PyEval_RestoreThread(t->state); /* Swap in our local thread state */
        PyThreadState_Clear(t->state);
        PyEval_SaveThread();
 
        PyThreadState_Delete(t->state); /* Don't need to hold lock for this */
 
        return 0;
}
 
static int libpython_init(void)
{
#define LOAD_INFO(_fmt, ...) fr_log(LOG_DST, L_INFO, __FILE__, __LINE__, "rlm_python - " _fmt,  ## __VA_ARGS__)
#define LOAD_WARN(_fmt, ...) fr_log_perror(LOG_DST, L_WARN, __FILE__, __LINE__, \
                                           (&(fr_log_perror_format_t){ \
                                                .first_prefix = "rlm_python - ", \
                                                .subsq_prefix = "rlm_python - ", \
                                           }), \
                                           _fmt,  ## __VA_ARGS__)
        PyConfig        config;
        PyStatus        status;
        wchar_t         *wide_name;
 
        fr_assert(!Py_IsInitialized());
 
        LOAD_INFO("Python version: %s", Py_GetVersion());
        dependency_version_number_add(NULL, "python", Py_GetVersion());
 
        /*
         *      Load python using RTLD_GLOBAL and dlopen.
         *      This fixes issues where python C extensions
         *      can't find the symbols they need.
         */
        python_dlhandle = dl_open_by_sym("Py_IsInitialized", RTLD_NOW | RTLD_GLOBAL);
        if (!python_dlhandle) LOAD_WARN("Failed loading libpython symbols into global symbol table");
 
        PyConfig_InitPythonConfig(&config);
 
        /*
         *      Set program name (i.e. the software calling the interpreter)
         *      The value of argv[0] as a wide char string
         */
        wide_name = Py_DecodeLocale(main_config->name, NULL);
        status = PyConfig_SetString(&config, &config.program_name, wide_name);
        PyMem_RawFree(wide_name);
 
        if (PyStatus_Exception(status)) {
        fail:
                LOAD_WARN("%s", status.err_msg);
                PyConfig_Clear(&config);
                return -1;
        }
 
        /*
         *      Python 3 introduces the concept of a
         *      "inittab", i.e. a list of modules which
         *      are automatically created when the first
         *      interpreter is spawned.
         */
        PyImport_AppendInittab("freeradius", python_module_init);
 
        if (libpython_global_config.path) {
                wchar_t *wide_path = Py_DecodeLocale(libpython_global_config.path, NULL);
 
                if (libpython_global_config.path_include_default) {
                        /*
                         *      The path from config is to be used in addition to the default.
                         *      Set it in the pythonpath_env.
                         */
                        status = PyConfig_SetString(&config, &config.pythonpath_env, wide_path);
                } else {
                        /*
                         *      Only the path from config is to be used.
                         *      Setting module_search_paths_set to 1 disables any automatic paths.
                         */
                        config.module_search_paths_set = 1;
                        status = PyWideStringList_Append(&config.module_search_paths, wide_path);
                }
                PyMem_RawFree(wide_path);
                if (PyStatus_Exception(status)) goto fail;
        }
 
        config.install_signal_handlers = 0;     /* Don't override signal handlers - noop on subs calls */
 
        if (libpython_global_config.verbose) config.verbose = 1;        /* Enable libpython logging*/
 
        LSAN_DISABLE(status = Py_InitializeFromConfig(&config));
        if (PyStatus_Exception(status)) goto fail;
 
        PyConfig_Clear(&config);
 
        global_interpreter = PyEval_SaveThread();       /* Store reference to the main interpreter and release the GIL */
 
        return 0;
}
 
static void libpython_free(void)
{
        PyThreadState_Swap(global_interpreter); /* Swap to the main thread */
 
        /*
         *      PyImport_Cleanup - Leaks memory in python 3.6
         *      should check once we require 3.8 that this is
         *      still needed.
         */
        LSAN_DISABLE(Py_Finalize());                    /* Ignore leaks on exit, we don't reload modules so we don't care */
        if (python_dlhandle) dlclose(python_dlhandle);  /* dlclose will SEGV on null handle */
}
 
/*
 *      Restrict automatic Python function names to lowercase characters, numbers and underscore
 *      meaning that a module call in `recv Access-Request` will look for `recv_access_request`
 */
static void python_func_name_safe(char *name) {
        char    *p;
        size_t  i;
 
        p = name;
        for (i = 0; i < talloc_array_length(name); i++) {
                *p = tolower(*p);
                if (!strchr("abcdefghijklmnopqrstuvwxyz1234567890", *p)) *p = '_';
                p++;
        }
}
 
static int python_func_parse(TALLOC_CTX *ctx, call_env_parsed_head_t *out, UNUSED tmpl_rules_t const *t_rules,
                             UNUSED CONF_ITEM *ci, call_env_ctx_t const *cec, call_env_parser_t const *rule)
{
        rlm_python_t            *inst = talloc_get_type_abort(cec->mi->data, rlm_python_t);
        call_env_parsed_t       *parsed;
        python_func_def_t       *func;
        void                    *found;
 
        if (!inst->funcs_init) {
                fr_rb_inline_init(&inst->funcs, python_func_def_t, node, python_func_def_cmp, NULL);
                inst->funcs_init = true;
        }
 
        MEM(parsed = call_env_parsed_add(ctx, out,
                                         &(call_env_parser_t){
                                                .name = "func",
                                                .flags = CALL_ENV_FLAG_PARSE_ONLY,
                                                .pair = {
                                                        .parsed = {
                                                                .offset = rule->pair.offset,
                                                                .type = CALL_ENV_PARSE_TYPE_VOID
                                                        }
                                                }
                                         }));
 
        MEM(func = talloc_zero(inst, python_func_def_t));
        func->name1 = talloc_strdup(func, cec->asked->name1);
        python_func_name_safe(func->name1);
        if (cec->asked->name2) {
                func->name2 = talloc_strdup(func, cec->asked->name2);
                python_func_name_safe(func->name2);
        }
 
        if (fr_rb_find_or_insert(&found, &inst->funcs, func) < 0) {
                talloc_free(func);
                return -1;
        }
 
        /*
         *      If the function call is already in the tree, use that entry.
         */
        if (found) {
                talloc_free(func);
                call_env_parsed_set_data(parsed, found);
        } else {
                call_env_parsed_set_data(parsed, func);
        }
        return 0;
}
 
static const call_env_method_t python_method_env = {
        FR_CALL_ENV_METHOD_OUT(python_call_env_t),
        .env = (call_env_parser_t[]) {
                { FR_CALL_ENV_SUBSECTION_FUNC(CF_IDENT_ANY, CF_IDENT_ANY, CALL_ENV_FLAG_PARSE_MISSING, python_func_parse) },
                CALL_ENV_TERMINATOR
        }
};
 
/*
 *      The module name should be the only globally exported symbol.
 *      That is, everything else should be 'static'.
 *
 *      If the module needs to temporarily modify it's instantiation
 *      data, the type should be changed to MODULE_TYPE_THREAD_UNSAFE.
 *      The server will then take care of ensuring that the module
 *      is single-threaded.
 */
extern module_rlm_t rlm_python;
module_rlm_t rlm_python = {
        .common = {
                .magic                  = MODULE_MAGIC_INIT,
                .name                   = "python",
 
                .inst_size              = sizeof(rlm_python_t),
                .thread_inst_size       = sizeof(rlm_python_thread_t),
 
                .config                 = module_config,
 
                .instantiate            = mod_instantiate,
                .detach                 = mod_detach,
 
                .thread_instantiate     = mod_thread_instantiate,
                .thread_detach          = mod_thread_detach
        },
        .method_group = {
                .bindings = (module_method_binding_t[]){
                        { .section = SECTION_NAME(CF_IDENT_ANY, CF_IDENT_ANY), .method = mod_python, .method_env = &python_method_env },
                        MODULE_BINDING_TERMINATOR
                }
        }
};