xlat_priv.h

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#pragma once
/*
 *   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: bdf7ab068ec85e73d93f5828e9eaec0a6a36260b $
 *
 * @file src/lib/unlang/xlat_priv.h
 * @brief String expansion ("translation"). Implements %Attribute -> value
 *
 * Private structures for the xlat tokenizer and xlat eval code.
 *
 * @copyright 2000,2006 The FreeRADIUS server project
 * @copyright 2000 Alan DeKok (aland@freeradius.org)
 */
#ifdef __cplusplus
extern "C" {
#endif
 
#include <freeradius-devel/unlang/xlat_ctx.h>
#include <freeradius-devel/unlang/xlat.h>
#include <freeradius-devel/unlang/xlat_func.h>
#include <freeradius-devel/io/pair.h>
#include <freeradius-devel/util/talloc.h>
#include <freeradius-devel/build.h>
 
#ifdef DEBUG_XLAT
#  define XLAT_DEBUG RDEBUG3
#else
#  define XLAT_DEBUG(...)
#endif
 
/*
 *      Allow public and private versions of the same structures
 */
#ifdef _CONST
#  error _CONST can only be defined in the local header
#endif
#ifndef _XLAT_PRIVATE
#  define _CONST const
#else
#  define _CONST
#endif
 
typedef struct xlat_s {
        fr_rb_node_t            node;                   //!< Entry in the xlat function tree.
        char const              *name;                  //!< Name of xlat function.
        xlat_func_t             func;                   //!< async xlat function (async unsafe).
 
        bool                    internal;               //!< If true, cannot be redefined.
        fr_token_t              token;                  //!< for expressions
 
        module_inst_ctx_t const *mctx;                  //!< Original module instantiation ctx if this
                                                        ///< xlat was registered by a module.
 
        xlat_instantiate_t      instantiate;            //!< Instantiation function.
        xlat_detach_t           detach;                 //!< Destructor for when xlat instances are freed.
        char const              *inst_type;             //!< C type of instance structure.
        size_t                  inst_size;              //!< Size of instance data to pre-allocate.
        void                    *uctx;                  //!< uctx to pass to instantiation functions.
 
        xlat_thread_instantiate_t thread_instantiate;   //!< Thread instantiation function.
        xlat_thread_detach_t    thread_detach;          //!< Destructor for when xlat thread instance data
                                                        ///< is freed.
        char const              *thread_inst_type;      //!< C type of thread instance structure.
        size_t                  thread_inst_size;       //!< Size of the thread instance data to pre-allocate.
        void                    *thread_uctx;           //!< uctx to pass to instantiation functions.
 
        xlat_print_t            print;                  //!< function to call when printing
        xlat_resolve_t          resolve;                //!< function to call when resolving
        xlat_purify_t           purify;                 //!< function to call when purifying the node.
 
        xlat_flags_t            flags;                  //!< various flags
 
        xlat_input_type_t       input_type;             //!< Type of input used.
        xlat_arg_parser_t const *args;                  //!< Definition of args consumed.
 
        call_env_method_t const *call_env_method;       //!< Optional tmpl expansions performed before calling the
                                                        ///< xlat.  Typically used for xlats which refer to tmpls
                                                        ///< in their module config.
 
        fr_value_box_safe_for_t return_safe_for;        //!< Escaped value to set in output boxes.
        fr_type_t               return_type;            //!< Function is guaranteed to return one or more boxes
                                                        ///< of this type.  If the return type is FR_TYPE_VOID
                                                        ///< then the xlat function can return any type of output.
} xlat_t;
 
typedef enum {
        XLAT_INVALID            = 0x0000,               //!< Bad expansion
        XLAT_BOX                = 0x0001,               //!< #fr_value_box_t
        XLAT_ONE_LETTER         = 0x0002,               //!< Special "one-letter" expansion
        XLAT_FUNC               = 0x0004,               //!< xlat module
        XLAT_FUNC_UNRESOLVED    = 0x0008,               //!< func needs resolution during pass2.
        XLAT_VIRTUAL            = 0x0010,               //!< virtual attribute
        XLAT_VIRTUAL_UNRESOLVED = 0x0020,               //!< virtual attribute needs resolution during pass2.
        XLAT_TMPL               = 0x0040,               //!< xlat attribute
#ifdef HAVE_REGEX
        XLAT_REGEX              = 0x0080,               //!< regex reference %{1}, etc.
#endif
        XLAT_GROUP              = 0x0200                //!< encapsulated string of xlats
} xlat_type_t;
 
/** An xlat function call
 *
 */
typedef struct {
        uint64_t                id;                     //!< Identifier unique to each permanent xlat node.
                                                        ///< This is used by the instantiation code to order
                                                        ///< nodes by the time they were created.
 
        xlat_t const            *func;                  //!< The xlat expansion to expand format with.
        xlat_exp_head_t         *args;                  //!< arguments to the function call
 
        fr_dict_t const         *dict;                  //!< Records the namespace this xlat call was created in.
                                                        ///< Used by the purify code to run fake requests in
                                                        ///< the correct namespace, and accessible to instantiation
                                                        ///< functions in case the xlat needs to perform runtime
                                                        ///< resolution of attributes (as with %eval()).
 
        xlat_inst_t             *inst;                  //!< Instance data for the #xlat_t.
        xlat_thread_inst_t      *thread_inst;           //!< Thread specific instance.
                                                        ///< ONLY USED FOR EPHEMERAL XLATS.
 
        bool                    ephemeral;              //!< Instance data is ephemeral (not inserted)
                                                        ///< into the instance tree.
        xlat_input_type_t       input_type;             //!< The input type used inferred from the
                                                        ///< bracketing style.
} xlat_call_t;
 
/** An xlat expansion node
 *
 * These nodes form a tree which represents one or more nested expansions.
 */
struct xlat_exp_s {
        fr_dlist_t              entry;
 
        char const *  _CONST    fmt;            //!< The original format string (a talloced buffer).
        fr_token_t              quote;          //!< Type of quoting around XLAT_GROUP types.
 
        xlat_flags_t            flags;          //!< Flags that control resolution and evaluation.
        xlat_type_t _CONST      type;           //!< type of this expansion.
 
#ifndef NDEBUG
        char const * _CONST     file;           //!< File where the xlat was allocated.
        int                     line;           //!< Line where the xlat was allocated.
#endif
 
        union {
                xlat_exp_head_t *group;         //!< children of a group
 
                /** An tmpl_t reference
                 *
                 * May be an attribute to expand, or an exec reference, or a value-box, ...
                 */
                tmpl_t          *vpt;
 
                /** A capture group, i.e. for %{1} and friends
                 */
                int             regex_index;
 
                /** An xlat function call
                 */
                xlat_call_t     call;
 
                /** A value box
                 */
                fr_value_box_t  data;
        };
};
 
struct xlat_exp_head_s {
        fr_dlist_head_t         dlist;
        xlat_flags_t            flags;          //!< Flags that control resolution and evaluation.
        bool                    instantiated;   //!< temporary flag until we fix more things
 
#ifndef NDEBUG
        char const * _CONST     file;           //!< File where the xlat was allocated.
        int                     line;           //!< Line where the xlat was allocated.
#endif
};
 
typedef struct {
        char const              *out;           //!< Output data.
        size_t                  len;            //!< Length of the output string.
} xlat_out_t;
/*
 *      Helper functions
 */
 
static inline xlat_exp_t *xlat_exp_head(xlat_exp_head_t const *head)
{
        if (!head) return NULL;
 
        return fr_dlist_head(&head->dlist);
}
 
/** Iterate over the contents of a list, only one level
 *
 * @param[in] _list_head        to iterate over.
 * @param[in] _iter             Name of iteration variable.
 *                              Will be declared in the scope of the loop.
 */
#define xlat_exp_foreach(_list_head, _iter) fr_dlist_foreach(&((_list_head)->dlist), xlat_exp_t, _iter)
 
/** Merge flags from child to parent
 *
 * For pass2, if either the parent or child is marked up for pass2, then the parent
 * is marked up for pass2.
 */
static inline CC_HINT(nonnull) void xlat_flags_merge(xlat_flags_t *parent, xlat_flags_t const *child)
{
        parent->needs_resolving |= child->needs_resolving;
        parent->pure &= child->pure; /* purity can only be removed, never added */
        parent->can_purify |= child->can_purify;
        parent->constant &= child->constant;
}
 
static inline CC_HINT(nonnull) int xlat_exp_insert_tail(xlat_exp_head_t *head, xlat_exp_t *node)
{
        XLAT_VERIFY(node);
 
        xlat_flags_merge(&head->flags, &node->flags);
        return fr_dlist_insert_tail(&head->dlist, node);
}
 
static inline xlat_exp_t *xlat_exp_next(xlat_exp_head_t const *head, xlat_exp_t const *node)
{
        if (!head) return NULL;
 
        return fr_dlist_next(&head->dlist, node);
}
 
/*
 *      xlat_purify.c
 */
int xlat_purify_list(xlat_exp_head_t *head, request_t *request);
 
/** Walker callback for xlat_walk()
 *
 * @param[in] exp       being evaluated.
 * @param[in] uctx      passed to xlat_walk.
 * @return
 *      - 1 for "prune walk here".
 *      - 0 on success.
 *      - <0 if node evaluation failed.  Causes xlat_walk to return the negative integer.
 */
typedef int (*xlat_walker_t)(xlat_exp_t *exp, void *uctx);
 
/*
 *      xlat_alloc.c
 */
xlat_exp_head_t *_xlat_exp_head_alloc(NDEBUG_LOCATION_ARGS TALLOC_CTX *ctx);
#define         xlat_exp_head_alloc(_ctx) _xlat_exp_head_alloc(NDEBUG_LOCATION_EXP _ctx)
 
void            _xlat_exp_set_type(NDEBUG_LOCATION_ARGS xlat_exp_t *node, xlat_type_t type);
#define         xlat_exp_set_type(_node, _type) _xlat_exp_set_type(NDEBUG_LOCATION_EXP _node, _type)
 
xlat_exp_t      *_xlat_exp_alloc_null(NDEBUG_LOCATION_ARGS TALLOC_CTX *ctx);
#define         xlat_exp_alloc_null(_ctx) _xlat_exp_alloc_null(NDEBUG_LOCATION_EXP _ctx)
 
xlat_exp_t      *_xlat_exp_alloc(NDEBUG_LOCATION_ARGS TALLOC_CTX *ctx, xlat_type_t type, char const *in, size_t inlen);
#define         xlat_exp_alloc(_ctx, _type, _in, _inlen) _xlat_exp_alloc(NDEBUG_LOCATION_EXP _ctx, _type, _in, _inlen)
 
void            xlat_exp_set_name(xlat_exp_t *node, char const *fmt, size_t len) CC_HINT(nonnull);
void            xlat_exp_set_name_buffer_shallow(xlat_exp_t *node, char const *fmt) CC_HINT(nonnull);
void            xlat_exp_set_name_buffer(xlat_exp_t *node, char const *fmt) CC_HINT(nonnull);
 
/*
 *      xlat_func.c
 */
xlat_t          *xlat_func_find(char const *name, ssize_t namelen);
 
/*
 *      xlat_eval.c
 */
extern fr_dict_attr_t const *attr_expr_bool_enum;
extern fr_dict_attr_t const *attr_module_return_code;
extern fr_dict_attr_t const *attr_cast_base;
 
/*
 *      xlat_tokenize.c
 */
extern bool const xlat_func_chars[UINT8_MAX + 1];
 
void            xlat_signal(xlat_func_signal_t signal, xlat_exp_t const *exp,
                            request_t *request, void *rctx, fr_signal_t action);
 
xlat_action_t   xlat_frame_eval_resume(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                       xlat_exp_head_t const **child,
                                       request_t *request,  xlat_exp_head_t const *head, xlat_exp_t const **in,
                                       fr_value_box_list_t *result, xlat_func_t resume, void *rctx);
 
xlat_action_t   xlat_frame_eval_repeat(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                       xlat_exp_head_t const **child,
                                       request_t *request, xlat_exp_head_t const *head, xlat_exp_t const **in,
                                       void *env_data, fr_value_box_list_t *result) CC_HINT(nonnull(1,2,3,4));
 
xlat_action_t   xlat_frame_eval(TALLOC_CTX *ctx, fr_dcursor_t *out, xlat_exp_head_t const **child,
                                request_t *request, xlat_exp_head_t const *head, xlat_exp_t const **in);
 
int             xlat_eval_walk(xlat_exp_head_t *head, xlat_walker_t walker, xlat_type_t type, void *uctx);
 
int             xlat_eval_init(void);
 
void            xlat_eval_free(void);
 
void            unlang_xlat_init(void);
 
int             unlang_xlat_push_node(TALLOC_CTX *ctx, bool *p_success, fr_value_box_list_t *out,
                                      request_t *request, xlat_exp_t *node);
 
int             xlat_decode_value_box_list(TALLOC_CTX *ctx, fr_pair_list_t *out,
                                           request_t *request, void *decode_ctx, fr_pair_decode_t decode,
                                           fr_value_box_list_t *in);
/*
 *      xlat_expr.c
 */
int             xlat_register_expressions(void);
 
/*
 *      xlat_tokenize.c
 */
int             xlat_tokenize_expansion(xlat_exp_head_t *head, fr_sbuff_t *in,
                                        tmpl_rules_t const *t_rules);
 
ssize_t         xlat_print_node(fr_sbuff_t *out, xlat_exp_head_t const *head, xlat_exp_t const *node,
                                fr_sbuff_escape_rules_t const *e_rules, char c);
 
#ifdef __cplusplus
}
#endif