1/*
2 * Copyright (c) 2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16#include "dslm_msg_serialize.h"
17
18#include <stdbool.h>
19#include <stdint.h>
20#include <stdlib.h>
21#include <string.h>
22
23#include "securec.h"
24
25#include "utils_json.h"
26#include "utils_log.h"
27#include "utils_mem.h"
28
29#define ASCII_MAX 0x7fU
30
31static inline bool IsAscii(const uint8_t ch)
32{
33    return (((ch) & (~ASCII_MAX)) == 0);
34}
35
36bool CheckMessage(const uint8_t *msg, uint32_t length)
37{
38    if (msg == NULL || length <= 1 || length > MSG_BUFF_MAX_LENGTH) {
39        return false;
40    }
41
42    // our msgs is a printable string
43    if (msg[length - 1] != '\0') {
44        return false;
45    }
46    for (uint32_t i = 0; i < length - 1; i++) {
47        if (!IsAscii(msg[i])) {
48            return false;
49        }
50    }
51    return true;
52}
53
54MessagePacket *ParseMessage(const MessageBuff *buff)
55{
56    if (buff == NULL) {
57        SECURITY_LOG_DEBUG("EMPTY BUFF");
58        return NULL;
59    }
60
61    if (!CheckMessage(buff->buff, buff->length)) {
62        SECURITY_LOG_DEBUG("ERR MSG");
63        return NULL;
64    }
65
66    DslmJsonHandle handle = DslmCreateJson((const char *)buff->buff);
67    if (handle == NULL) {
68        SECURITY_LOG_DEBUG("ERR JSON MSG");
69        return NULL;
70    }
71
72    char *payload = NULL;
73    MessagePacket *packet = NULL;
74    do {
75        int32_t msgType = DslmGetJsonFieldInt(handle, FIELD_MESSAGE);
76        if (msgType < 0) {
77            break;
78        }
79        payload = DslmConvertJsonToString(DslmGetJsonFieldJson(handle, FIELD_PAYLOAD));
80        if (payload == NULL) {
81            break;
82        }
83        packet = MALLOC(sizeof(MessagePacket));
84        if (packet == NULL) {
85            FREE(payload);
86            break;
87        }
88        packet->type = (uint32_t)msgType;
89        packet->payload = (uint8_t *)payload;
90        packet->length = strlen(payload) + 1; // for the end flag '\0'
91    } while (0);
92
93    DslmDestroyJson(handle);
94    return packet;
95}
96
97void FreeMessagePacket(MessagePacket *packet)
98{
99    if (packet == NULL) {
100        return;
101    }
102    if (packet->payload != NULL) {
103        FREE(packet->payload);
104        packet->payload = NULL;
105    }
106    FREE((void *)packet);
107}
108
109void FreeMessageBuff(MessageBuff *buff)
110{
111    if (buff == NULL) {
112        return;
113    }
114    if (buff->buff != NULL) {
115        FREE(buff->buff);
116        buff->buff = NULL;
117    }
118    FREE((void *)buff);
119}
120