cbor.c

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/*
 * Copyright (c) 2014-2017 Pavel Kalvoda <me@pavelkalvoda.com>
 *
 * libcbor is free software; you can redistribute it and/or modify
 * it under the terms of the MIT license. See LICENSE for details.
 */

#include "cbor.h"
#include "cbor/internal/builder_callbacks.h"
#include "cbor/internal/loaders.h"

cbor_item_t * cbor_load(cbor_data source,
                        size_t source_size,
                        struct cbor_load_result *result)
{
    /* Context stack */
    static struct cbor_callbacks callbacks = {
        .uint8 = &cbor_builder_uint8_callback,
        .uint16 = &cbor_builder_uint16_callback,
        .uint32 = &cbor_builder_uint32_callback,
        .uint64 = &cbor_builder_uint64_callback,

        .negint8 = &cbor_builder_negint8_callback,
        .negint16 = &cbor_builder_negint16_callback,
        .negint32 = &cbor_builder_negint32_callback,
        .negint64 = &cbor_builder_negint64_callback,

        .byte_string = &cbor_builder_byte_string_callback,
        .byte_string_start = &cbor_builder_byte_string_start_callback,

        .string = &cbor_builder_string_callback,
        .string_start = &cbor_builder_string_start_callback,

        .array_start = &cbor_builder_array_start_callback,
        .indef_array_start = &cbor_builder_indef_array_start_callback,

        .map_start = &cbor_builder_map_start_callback,
        .indef_map_start = &cbor_builder_indef_map_start_callback,

        .tag = &cbor_builder_tag_callback,

        .null = &cbor_builder_null_callback,
        .undefined = &cbor_builder_undefined_callback,
        .boolean = &cbor_builder_boolean_callback,
        .float2 = &cbor_builder_float2_callback,
        .float4 = &cbor_builder_float4_callback,
        .float8 = &cbor_builder_float8_callback,
        .indef_break = &cbor_builder_indef_break_callback
    };

    if (source_size == 0) {
        result->error.code = CBOR_ERR_NODATA;
        return NULL;
    }
    struct _cbor_stack stack = _cbor_stack_init();

    /* Target for callbacks */
    struct _cbor_decoder_context context = (struct _cbor_decoder_context) {
        .stack = &stack,
        .creation_failed = false,
        .syntax_error = false
    };
    struct cbor_decoder_result decode_result;
    *result = (struct cbor_load_result) {.read = 0, .error = {.code = CBOR_ERR_NONE}};

    do {
        if (source_size > result->read) { /* Check for overflows */
            decode_result = cbor_stream_decode(
                source + result->read,
                source_size - result->read,
                &callbacks,
                &context);
        } else {
            result->error = (struct cbor_error) {
                .code = CBOR_ERR_NOTENOUGHDATA,
                .position = result->read
            };
            goto error;
        }

        switch (decode_result.status) {
        case CBOR_DECODER_FINISHED:
            /* Everything OK */
        {
            result->read += decode_result.read;
            break;
        }
        case CBOR_DECODER_NEDATA:
            /* Data length doesn't match MTB expectation */
        {
            result->error.code = CBOR_ERR_NOTENOUGHDATA;
            goto error;
        }
        case CBOR_DECODER_EBUFFER:
            /* Fallthrough */
        case CBOR_DECODER_ERROR:
            /* Reserved/malformated item */
        {
            result->error.code = CBOR_ERR_MALFORMATED;
            goto error;
        }
        }

        if (context.creation_failed) {
            /* Most likely unsuccessful allocation - our callback has failed */
            result->error.code = CBOR_ERR_MEMERROR;
            goto error;
        } else if (context.syntax_error) {
            result->error.code = CBOR_ERR_SYNTAXERROR;
            goto error;
        }
    } while (stack.size > 0);

    /* Move the result before free */
    cbor_item_t *result_item = context.root;
    return result_item;

    error:
    result->error.position = result->read;
    //debug_print("Failed with decoder error %d at %d\n", result->error.code, result->error.position);
    //cbor_describe(stack.top->item, stdout);
    /* Free the stack */
    while (stack.size > 0) {
        cbor_decref(&stack.top->item);
        _cbor_stack_pop(&stack);
    }
    return NULL;
}


static cbor_item_t * _cbor_copy_int(cbor_item_t * item, bool negative)
{
    cbor_item_t * res;
    switch (cbor_int_get_width(item)) {
    case CBOR_INT_8: res = cbor_build_uint8(cbor_get_uint8(item)); break;
    case CBOR_INT_16: res = cbor_build_uint16(cbor_get_uint16(item)); break;
    case CBOR_INT_32: res = cbor_build_uint32(cbor_get_uint32(item)); break;
    case CBOR_INT_64: res = cbor_build_uint64(cbor_get_uint64(item)); break;
    default: return NULL;
    }

    if (negative)
        cbor_mark_negint(res);

    return res;
}

static cbor_item_t * _cbor_copy_float_ctrl(cbor_item_t * item)
{
    switch (cbor_float_get_width(item)) {
    case CBOR_FLOAT_0:
        return cbor_build_ctrl(cbor_ctrl_value(item));
    case CBOR_FLOAT_16:
        return cbor_build_float2(cbor_float_get_float2(item));
    case CBOR_FLOAT_32:
        return cbor_build_float4(cbor_float_get_float4(item));
    case CBOR_FLOAT_64:
        return cbor_build_float8(cbor_float_get_float8(item));
    }

    return NULL;
}

cbor_item_t * cbor_copy(cbor_item_t * item)
{
    switch (cbor_typeof(item)) {
    case CBOR_TYPE_UINT:
        return _cbor_copy_int(item, false);
    case CBOR_TYPE_NEGINT:
        return _cbor_copy_int(item, true);
    case CBOR_TYPE_BYTESTRING:
        if (cbor_bytestring_is_definite(item)) {
            return cbor_build_bytestring(cbor_bytestring_handle(item), cbor_bytestring_length(item));
        } else {
            cbor_item_t * res = cbor_new_indefinite_bytestring();
            for (size_t i = 0; i < cbor_bytestring_chunk_count(item); i++)
                cbor_bytestring_add_chunk(
                    res,
                    cbor_move(
                        cbor_copy(cbor_bytestring_chunks_handle(item)[i])
                    )
                );
            return res;
        }
    case CBOR_TYPE_STRING:
        if (cbor_string_is_definite(item)) {
            return cbor_build_stringn((const char *) cbor_string_handle(item), cbor_string_length(item));
        } else {
            cbor_item_t * res = cbor_new_indefinite_string();
            for (size_t i = 0; i < cbor_string_chunk_count(item); i++)
                cbor_string_add_chunk(
                    res,
                    cbor_move(
                        cbor_copy(cbor_string_chunks_handle(item)[i])
                    )
                );
            return res;
        }
    case CBOR_TYPE_ARRAY: {
        cbor_item_t * res;
        if (cbor_array_is_definite(item))
            res = cbor_new_definite_array(cbor_array_size(item));
        else
            res = cbor_new_indefinite_array();

        for (size_t i = 0; i < cbor_array_size(item); i++)
            cbor_array_push(
                res,
                cbor_move(cbor_copy(cbor_move(cbor_array_get(item, i))))
            );
        return res;
    }
    case CBOR_TYPE_MAP: {
        cbor_item_t * res;
        if (cbor_map_is_definite(item))
            res = cbor_new_definite_map(cbor_map_size(item));
        else
            res = cbor_new_indefinite_map();

        struct cbor_pair * it = cbor_map_handle(item);
        for (size_t i = 0; i < cbor_map_size(item); i++)
            cbor_map_add(res, (struct cbor_pair) {
                .key = cbor_move(cbor_copy(it[i].key)),
                .value = cbor_move(cbor_copy(it[i].value))
            });
        return res;
    }
    case CBOR_TYPE_TAG:
        return cbor_build_tag(
            cbor_tag_value(item),
            cbor_move(cbor_copy(cbor_tag_item(item)))
        );
    case CBOR_TYPE_FLOAT_CTRL:
        return _cbor_copy_float_ctrl(item);
    }

    return NULL;
}

#if CBOR_PRETTY_PRINTER

#include <inttypes.h>
#include <wchar.h>
#include <locale.h>
#include <stdlib.h>

#define __STDC_FORMAT_MACROS

static int _pow(int b, int ex)
{
    if (ex == 0) return 1;
    int res = b;
    while (--ex > 0) res *= b;
    return res;
}

static void _cbor_nested_describe(cbor_item_t *item, FILE *out, int indent)
{
    setlocale(LC_ALL, "");
    switch (cbor_typeof(item)) {
    case CBOR_TYPE_UINT: {
        fprintf(out, "%*s[CBOR_TYPE_UINT] ", indent, " ");
        fprintf(out, "Width: %dB, ", _pow(2, cbor_int_get_width(item)));
        fprintf(out, "Value: %"PRIu64"\n", cbor_get_int(item));
        break;
    };
    case CBOR_TYPE_NEGINT: {
        fprintf(out, "%*s[CBOR_TYPE_NEGINT] ", indent, " ");
        fprintf(out, "Width: %dB, ", _pow(2, cbor_int_get_width(item)));
        fprintf(out, "Value: -%"PRIu64" -1\n", cbor_get_int(item));
        break;
    };
    case CBOR_TYPE_BYTESTRING: {
        fprintf(out, "%*s[CBOR_TYPE_BYTESTRING] ", indent, " ");
        if (cbor_bytestring_is_indefinite(item)) {
            fprintf(out,
                    "Indefinite, with %zu chunks:\n",
                    cbor_bytestring_chunk_count(item));
            for (size_t i = 0; i < cbor_bytestring_chunk_count(item); i++)
                _cbor_nested_describe(
                    cbor_bytestring_chunks_handle(item)[i],
                    out,
                    indent + 4);
        } else {
            fprintf(out,
                    "Definite, length %zuB\n",
                    cbor_bytestring_length(item));
        }
        break;
    };
    case CBOR_TYPE_STRING: {
        fprintf(out, "%*s[CBOR_TYPE_STRING] ", indent, " ");
        if (cbor_string_is_indefinite(item)) {
            fprintf(out,
                    "Indefinite, with %zu chunks:\n",
                    cbor_string_chunk_count(item));
            for (size_t i = 0; i < cbor_string_chunk_count(item); i++)
                _cbor_nested_describe(
                    cbor_string_chunks_handle(item)[i],
                    out,
                    indent + 4);
        } else {
            fprintf(out,
                    "Definite, length %zuB, %zu codepoints\n",
                    cbor_string_length(item),
                    cbor_string_codepoint_count(item));
            /* Careful - this doesn't support multibyte characters! */
            /* Printing those is out of the scope of this demo :) */
            /* libICU is your friend */
            fprintf(out, "%*s", indent + 4, " ");
            /* XXX: no null at the end -> confused vprintf */
            fwrite(cbor_string_handle(item), (int) cbor_string_length(item), 1, out);
            fprintf(out, "\n");
        }
        break;
    };
    case CBOR_TYPE_ARRAY: {
        fprintf(out, "%*s[CBOR_TYPE_ARRAY] ", indent, " ");
        if (cbor_array_is_definite(item)) {
            fprintf(out,
                    "Definite, size: %zu\n",
                    cbor_array_size(item));
        } else {
            fprintf(out,
                    "Indefinite, size:  %zu\n",
                    cbor_array_size(item));
        }

        for (size_t i = 0; i < cbor_array_size(item); i++)
            _cbor_nested_describe(
                cbor_array_handle(item)[i],
                out,
                indent + 4);
        break;
    };
    case CBOR_TYPE_MAP: {
        fprintf(out, "%*s[CBOR_TYPE_MAP] ", indent, " ");
        if (cbor_map_is_definite(item)) {
            fprintf(out,
                    "Definite, size: %zu\n",
                    cbor_map_size(item));
        } else {
            fprintf(out,
                    "Indefinite, size:  %zu\n",
                    cbor_map_size(item));
        }

        for (size_t i = 0; i < cbor_map_size(item); i++) {
            _cbor_nested_describe(
                cbor_map_handle(item)[i].key,
                out,
                indent + 4);
            _cbor_nested_describe(
                cbor_map_handle(item)[i].value,
                out,
                indent + 4);
        }
        break;
    };
    case CBOR_TYPE_TAG: {
        fprintf(out, "%*s[CBOR_TYPE_TAG] ", indent, " ");
        fprintf(out, "Value: %"PRIu64"\n", cbor_tag_value(item));
        _cbor_nested_describe(cbor_tag_item(item), out, indent + 4);
        break;
    };
    case CBOR_TYPE_FLOAT_CTRL: {
        fprintf(out, "%*s[CBOR_TYPE_FLOAT_CTRL] ", indent, " ");
        if (cbor_float_ctrl_is_ctrl(item)) {
            if (cbor_is_bool(item))
                fprintf(out, "Bool: %s\n", cbor_ctrl_is_bool(item) ? "true" : "false");
            else if (cbor_is_undef(item))
                fprintf(out, "Undefined\n");
            else if (cbor_is_null(item))
                fprintf(out, "Null\n");
            else
                fprintf(out, "Simple value %d\n", cbor_ctrl_value(item));
        } else {
            fprintf(out, "Width: %dB, ", _pow(2, cbor_float_get_width(item)));
            fprintf(out, "value: %lf\n", cbor_float_get_float(item));
        }
        break;
    };
    }
}

void cbor_describe(cbor_item_t *item, FILE *out)
{
    _cbor_nested_describe(item, out, 0);
}

#endif