talloc.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
 */
 
/** Functions which we wish were included in the standard talloc distribution
 *
 * @file src/lib/util/talloc.h
 *
 * @copyright 2017 The FreeRADIUS server project
 * @copyright 2017 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 */
RCSIDH(talloc_h, "$Id: 1d7cc13b2df104e1dda30f82c3a15c5816e72fc9 $")
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include <ctype.h>
#include <stdbool.h>
#include <stdint.h>
 
#ifdef HAVE_WDOCUMENTATION
DIAG_OFF(documentation)
#endif
#include <talloc.h>
#ifdef HAVE_WDOCUMENTATION
DIAG_ON(documentation)
#endif
 
#include <freeradius-devel/autoconf.h>  /* Very easy to miss including in special builds */
#include <freeradius-devel/build.h>
#include <freeradius-devel/missing.h>
#include <freeradius-devel/util/sbuff.h>
 
#undef talloc_autofree_context
/** The original function is deprecated, so replace it with our version
 */
#define talloc_autofree_context talloc_autofree_context_global
 
/** Iterate over a talloced array of elements
 *
@verbatim
talloc_foreach(vpt_m, vpt) {
        tmpl_debug(vpt);
}
@endverbatim
 *
 * There seems to be a limitation in for loop initialiser arguments where they all
 * must be the same type, though we can control the number of layers of pointer
 * indirection on a per variable basis.
 *
 * We declare _p to be a pointer of the specified _type, and initialise it to the
 * start of the array.  We declare _end to be a pointer of the specified type and
 * initialise it to point to the end of the array using talloc_array_length().
 *
 * _iter is only updated in the condition to avoid de-referencing invalid memory.
 *
 * @param[in] _array    to iterate over.  May contain zero elements.
 * @param[in] _iter     Name of iteration variable.
 *                      Will be declared in the scope of the loop.
 */
#define talloc_foreach(_array, _iter) \
        for (__typeof__(_array[0]) _iter, *_p = (void *)(_array), *_end = _array ? (void *)((_array) + talloc_array_length(_array)) : NULL; \
             (_p < _end) && (_iter = *((void **)(uintptr_t)(_p))); \
             _p = (__typeof__(_p))((__typeof__(_array))_p) + 1)
 
typedef int(* fr_talloc_free_func_t)(void *fire_ctx, void *uctx);
 
typedef struct fr_talloc_destructor_s fr_talloc_destructor_t;
typedef struct fr_talloc_destructor_disarm_s fr_talloc_destructor_disarm_t;
 
/** Structure to record a destructor operation on a specific talloc chunk
 *
 * Provided here so that additional memory can be allocated with talloc pool.
 */
struct fr_talloc_destructor_s {
        void                            *fire;                  //!< Parent chunk.
 
        fr_talloc_free_func_t           func;                   //!< Free function.
        void                            *uctx;                  //!< uctx to pass to free function.
        fr_talloc_destructor_disarm_t   *ds;                    //!< Chunk to free.
};
 
/** Structure to record a destructor to disarm if a child talloc chunk is freed
 *
 * Provided here so that additional memory can be allocated with talloc pool.
 */
struct fr_talloc_destructor_disarm_s {
        fr_talloc_destructor_t          *d;     //!< Destructor to disarm.
};
 
/** Allocate a top level chunk with a constant name
 *
 * @param[in] name      Must be a string literal.
 * @return
 *      - NULL on allocation error.
 *      - A new talloc chunk on success.
 */
static inline TALLOC_CTX *talloc_init_const(char const *name)
{
        TALLOC_CTX *ctx;
 
        ctx = talloc_new(NULL);
        if (unlikely(!ctx)) return NULL;
 
        talloc_set_name_const(ctx, name);
 
        return ctx;
}
 
void            talloc_free_data(void *data);
 
void            *talloc_null_ctx(void);
 
fr_talloc_destructor_t *talloc_destructor_add(TALLOC_CTX *fire_ctx, TALLOC_CTX *disarm_ctx,
                                              fr_talloc_free_func_t func, void const *uctx);
 
void            talloc_destructor_disarm(fr_talloc_destructor_t *d);
 
int             talloc_link_ctx(TALLOC_CTX *parent, TALLOC_CTX *child);
 
TALLOC_CTX      *talloc_page_aligned_pool(TALLOC_CTX *ctx, void **start, void **end, size_t size);
TALLOC_CTX      *talloc_aligned_array(TALLOC_CTX *ctx, void **start, size_t alignment, size_t size);
 
/*
 *      Add variant that zeroes out newly allocated memory
 */
#if defined(HAVE__TALLOC_POOLED_OBJECT) && defined(talloc_pooled_object)
#  define HAVE_TALLOC_ZERO_POOLED_OBJECT        1
#  define HAVE_TALLOC_POOLED_OBJECT             1
 
#  define       talloc_zero_pooled_object(_ctx, _type, _num_subobjects, _total_subobjects_size) \
                (_type *)_talloc_zero_pooled_object((_ctx), sizeof(_type), #_type, \
                                                    (_num_subobjects), (_total_subobjects_size))
 
static inline TALLOC_CTX *_talloc_zero_pooled_object(const void *ctx,
                                                     size_t type_size,
                                                     const char *type_name,
                                                     unsigned num_subobjects,
                                                     size_t total_subobjects_size)
{
        TALLOC_CTX *new;
        new = _talloc_pooled_object(ctx, type_size, type_name, num_subobjects, total_subobjects_size);
        if (unlikely(!new)) return NULL;
        memset(new, 0, type_size);
        return new;
}
/*
 *      Fall back to non-pooled variants
 */
#else
#  define       talloc_zero_pooled_object(_ctx, _type, _num_subobjects, _total_subobjects_size) \
                talloc_zero(_ctx, _type)
#undef talloc_pooled_object
#  define       talloc_pooled_object(_ctx, _type, _num_subobjects, _total_subobjects_size) \
                talloc(_ctx, _type)
#endif
 
/** @hidecallergraph */
char            *talloc_typed_strdup(TALLOC_CTX *ctx, char const *p);
 
char            *talloc_typed_strdup_buffer(TALLOC_CTX *ctx, char const *p);
 
char            *talloc_typed_asprintf(TALLOC_CTX *ctx, char const *fmt, ...) CC_HINT(format (printf, 2, 3));
 
char            *talloc_typed_vasprintf(TALLOC_CTX *ctx, char const *fmt, va_list ap) CC_HINT(format (printf, 2, 0)) CC_HINT(nonnull (2));
 
uint8_t         *talloc_typed_memdup(TALLOC_CTX *ctx, uint8_t const *in, size_t inlen);
 
char            *talloc_bstrdup(TALLOC_CTX *ctx, char const *in);
 
char            *talloc_bstrndup(TALLOC_CTX *ctx, char const *in, size_t inlen);
 
char            *talloc_bstr_append(TALLOC_CTX *ctx, char *to, char const *from, size_t from_len);
 
char            *talloc_bstr_realloc(TALLOC_CTX *ctx, char *in, size_t inlen);
 
char            *talloc_buffer_append_buffer(TALLOC_CTX *ctx, char *to, char const *from);
 
char            *talloc_buffer_append_variadic_buffer(TALLOC_CTX *ctx, char *to, int argc, ...);
 
int             talloc_memcmp_array(uint8_t const *a, uint8_t const *b);
 
int             talloc_memcmp_bstr(char const *a, char const *b);
 
int             talloc_decrease_ref_count(void const *ptr);
 
void            **talloc_array_null_terminate(void **array);
 
void            **talloc_array_null_strip(void **array);
 
fr_slen_t       talloc_array_concat(fr_sbuff_t *out, char const * const *array, char const *sep);
 
 
/** Free const'd memory
 *
 * @param[in] ptr       to free.
 */
static inline int talloc_const_free(void const *ptr)
{
        if (!ptr) return 0;
 
        return talloc_free(UNCONST(void *, ptr));
}
 
/** Free a list of talloced structures containing a next field
 *
 * @param[in] _head     of list to free.  Will set memory it points to to be NULL.
 */
#define talloc_list_free(_head) _talloc_list_free((void **)_head, offsetof(__typeof__(**(_head)), next))
 
static inline void _talloc_list_free(void **head, size_t offset)
{
        void *v = *head, *n;
 
        while (v) {
                n = *((void **)(((uint8_t *)(v)) + offset));
                talloc_free(v);
                v = n;
        }
        *head = NULL;
}
 
/** Verify a list of talloced structures are the correct type and are still valid
 *
 * @param[in] _head     of list to check.
 * @param[in] _type     of talloced chunk we expect.
 */
#ifndef TALLOC_GET_TYPE_ABORT_NOOP
#  define talloc_list_get_type_abort(_head, _type) (_type *)_talloc_list_get_type_abort(_head, offsetof(__typeof__(*(_head)), next), #_type, __location__)
static inline void *_talloc_list_get_type_abort(void *head, size_t offset, char const *type, char const *location)
{
        void *v = head, *n;
 
        if (!v) _talloc_get_type_abort(v, type, location);      /* Behave like the normal talloc_get_type_abort function */
 
        while (v) {
                n = *((void **)(((uint8_t *)(v)) + offset));
                _talloc_get_type_abort(v, type, location);
                v = n;
        }
 
        return head;
}
#else
#  define talloc_list_get_type_abort(_head, _type) (_type *)(_head)
#endif
 
/*
 *      talloc portability issues.  'const' is not part of the talloc
 *      type, but it is part of the pointer type.  But only if
 *      talloc_get_type_abort() is just a cast.
 */
#ifdef TALLOC_GET_TYPE_ABORT_NOOP
#  define talloc_get_type_abort_const(ptr, type) (const type *)(ptr)
#else
#  define talloc_get_type_abort_const talloc_get_type_abort
#endif
 
/** Returns the length of a talloc array containing a string
 *
 * @param[in] s to return the length of.
 */
static inline size_t talloc_strlen(char const *s)
{
        char const *our_s = talloc_get_type_abort_const(s, char);
        return talloc_array_length(our_s) - 1;
}
 
TALLOC_CTX              *talloc_autofree_context_global(void);
TALLOC_CTX              *talloc_autofree_context_thread_local(void);
 
typedef struct talloc_child_ctx_s TALLOC_CHILD_CTX;
 
TALLOC_CHILD_CTX        *talloc_child_ctx_init(TALLOC_CTX *ctx);
TALLOC_CHILD_CTX        *talloc_child_ctx_alloc(TALLOC_CHILD_CTX *parent) CC_HINT(nonnull);
 
#ifdef __cplusplus
}
#endif