curl/ares/ares_data.c

144 lines
3.5 KiB
C
Raw Normal View History

/* $Id$ */
/* Copyright (C) 2009 by Daniel Stenberg
*
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting
* documentation, and that the name of M.I.T. not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is"
* without express or implied warranty.
*/
#include "ares_setup.h"
#include <stddef.h>
#include "ares.h"
#include "ares_data.h"
#include "ares_private.h"
/*
** ares_free_data() - c-ares external API function.
**
** This function must be used by the application to free data memory that
** has been internally allocated by some c-ares function and for which a
** pointer has already been returned to the calling application. The list
** of c-ares functions returning pointers that must be free'ed using this
** function is:
**
** ares_parse_srv_reply()
** ares_parse_txt_reply()
*/
void ares_free_data(void *dataptr)
{
struct ares_data *ptr;
if (!dataptr)
return;
ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
if (ptr->mark != ARES_DATATYPE_MARK)
return;
switch (ptr->type)
{
case ARES_DATATYPE_SRV_REPLY:
if (ptr->data.srv_reply.next)
ares_free_data(ptr->data.srv_reply.next);
if (ptr->data.srv_reply.host)
free(ptr->data.srv_reply.host);
break;
case ARES_DATATYPE_TXT_REPLY:
if (ptr->data.txt_reply.next)
ares_free_data(ptr->data.txt_reply.next);
if (ptr->data.txt_reply.txt)
free(ptr->data.txt_reply.txt);
break;
default:
return;
}
free(ptr);
}
/*
** ares_malloc_data() - c-ares internal helper function.
**
** This function allocates memory for a c-ares private ares_data struct
** for the specified ares_datatype, initializes c-ares private fields
** and zero initializes those which later might be used from the public
** API. It returns an interior pointer which can be passed by c-ares
** functions to the calling application, and that must be free'ed using
** c-ares external API function ares_free_data().
*/
void *ares_malloc_data(ares_datatype type)
{
struct ares_data *ptr;
ptr = malloc(sizeof(struct ares_data));
if (!ptr)
return NULL;
switch (type)
{
case ARES_DATATYPE_SRV_REPLY:
ptr->data.srv_reply.next = NULL;
ptr->data.srv_reply.host = NULL;
ptr->data.srv_reply.priority = 0;
ptr->data.srv_reply.weight = 0;
ptr->data.srv_reply.port = 0;
break;
case ARES_DATATYPE_TXT_REPLY:
ptr->data.txt_reply.next = NULL;
ptr->data.txt_reply.txt = NULL;
ptr->data.txt_reply.length = 0;
break;
default:
free(ptr);
return NULL;
}
ptr->mark = ARES_DATATYPE_MARK;
ptr->type = type;
return &ptr->data;
}
/*
** ares_get_datatype() - c-ares internal helper function.
**
** This function returns the ares_datatype of the data stored in a
** private ares_data struct when given the public API pointer.
*/
ares_datatype ares_get_datatype(void * dataptr)
{
struct ares_data *ptr;
ptr = (void *)((char *)dataptr - offsetof(struct ares_data, data));
if (ptr->mark == ARES_DATATYPE_MARK)
return ptr->type;
return ARES_DATATYPE_UNKNOWN;
}