src/cborencoder_close_container_checked.c

/****************************************************************************
**
** Copyright (C) 2015 Intel Corporation
**
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** of this software and associated documentation files (the "Software"), to deal
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** furnished to do so, subject to the following conditions:
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#define _BSD_SOURCE 1
#define _DEFAULT_SOURCE 1
#ifndef __STDC_LIMIT_MACROS
#  define __STDC_LIMIT_MACROS 1
#endif

#include "cbor.h"
#include "cborconstants_p.h"
#include "compilersupport_p.h"
#include "extract_number_p.h"

#include <assert.h>

#include "assert_p.h"       /* Always include last */

/**
 * \addtogroup CborEncoding
 * @{
 */

/**
 *
 * Closes the CBOR container (array or map) provided by \a containerEncoder and
 * updates the CBOR stream provided by \a encoder. Both parameters must be the
 * same as were passed to cbor_encoder_create_array() or
 * cbor_encoder_create_map().
 *
 * Unlike cbor_encoder_close_container(), this function checks that the number
 * of items (or pair of items, in the case of a map) was correct. If the number
 * of items inserted does not match the length originally passed to
 * cbor_encoder_create_array() or cbor_encoder_create_map(), this function
 * returns either CborErrorTooFewItems or CborErrorTooManyItems.
 *
 * \sa cbor_encoder_create_array(), cbor_encoder_create_map()
 */
CborError cbor_encoder_close_container_checked(CborEncoder *encoder, const CborEncoder *containerEncoder)
{
    const uint8_t *ptr = encoder->data.ptr;
    CborError err = cbor_encoder_close_container(encoder, containerEncoder);
    if (containerEncoder->flags & CborIteratorFlag_UnknownLength || encoder->end == NULL)
        return err;

    /* check what the original length was */
    uint64_t actually_added;
    err = extract_number(&ptr, encoder->data.ptr, &actually_added);
    if (err)
        return err;

    if (containerEncoder->flags & CborIteratorFlag_ContainerIsMap) {
        if (actually_added > SIZE_MAX / 2)
            return CborErrorDataTooLarge;
        actually_added *= 2;
    }
    return actually_added == containerEncoder->added ? CborNoError :
           actually_added < containerEncoder->added ? CborErrorTooManyItems : CborErrorTooFewItems;
}

/** @} */