1 // Copyright (C) 2014-2017 Bayerische Motoren Werke Aktiengesellschaft (BMW AG)
2 // This Source Code Form is subject to the terms of the Mozilla Public
3 // License, v. 2.0. If a copy of the MPL was not distributed with this
4 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
5 
6 #include "../../../../../e2e_protection/include/e2e/profile/profile01/protector.hpp"
7 #include <vsomeip/internal/logger.hpp>
8 
9 #include <iostream>
10 #include <sstream>
11 #include <string>
12 #include <iomanip>
13 
14 namespace vsomeip_v3 {
15 namespace e2e {
16 namespace profile01 {
17 
18 /** @req [SWS_E2E_00195] */
protect(e2e_buffer & _buffer,instance_t _instance)19 void protector::protect(e2e_buffer &_buffer, instance_t _instance) {
20 
21     (void)_instance;
22 
23     std::lock_guard<std::mutex> lock(protect_mutex_);
24 
25     if (profile_01::is_buffer_length_valid(config_, _buffer)) {
26         // write the current Counter value in Data
27         write_counter(_buffer);
28 
29         // write DataID nibble in Data (E2E_P01_DATAID_NIBBLE) in Data
30         write_data_id(_buffer);
31 
32         // compute the CRC over DataID and Data
33         uint8_t computed_crc = profile_01::compute_crc(config_, _buffer);
34         // write CRC in Data
35         write_crc(_buffer, computed_crc);
36 
37         // increment the Counter (new value will be used in the next invocation of E2E_P01Protect()),
38         increment_counter();
39     }
40 }
41 
42 /** @req [SRS_E2E_08528] */
write_counter(e2e_buffer & _buffer)43 void protector::write_counter(e2e_buffer &_buffer) {
44     if (config_.counter_offset_ % 8 == 0) {
45         // write write counter value into low nibble
46         _buffer[config_.counter_offset_ / 8] =
47                 static_cast<uint8_t>((_buffer[config_.counter_offset_ / 8] & 0xF0) | (counter_ & 0x0F));
48     } else {
49         // write counter into high nibble
50         _buffer[config_.counter_offset_ / 8] =
51                 static_cast<uint8_t>((_buffer[config_.counter_offset_ / 8] & 0x0F) | ((counter_ << 4) & 0xF0));
52     }
53 }
54 
55 /** @req [SRS_E2E_08528] */
write_data_id(e2e_buffer & _buffer)56 void protector::write_data_id(e2e_buffer &_buffer) {
57     if (config_.data_id_mode_ == p01_data_id_mode::E2E_P01_DATAID_NIBBLE) {
58         if (config_.data_id_nibble_offset_ % 8 == 0) {
59             // write low nibble of high byte of Data ID
60             _buffer[config_.data_id_nibble_offset_ / 8] =
61                     static_cast<uint8_t>((_buffer[config_.data_id_nibble_offset_ / 8] & 0xF0) | ((config_.data_id_ >> 8) & 0x0F));
62         } else {
63             // write low nibble of high byte of Data ID
64             _buffer[config_.data_id_nibble_offset_ / 8] =
65                     static_cast<uint8_t>((_buffer[config_.data_id_nibble_offset_ / 8] & 0x0F) | ((config_.data_id_ >> 4) & 0xF0));
66         }
67     }
68 }
69 
70 /** @req [SRS_E2E_08528] */
write_crc(e2e_buffer & _buffer,uint8_t _computed_crc)71 void protector::write_crc(e2e_buffer &_buffer, uint8_t _computed_crc) {
72     _buffer[config_.crc_offset_] = _computed_crc;
73 }
74 
75 /** @req [SWS_E2E_00075] */
increment_counter(void)76 void protector::increment_counter(void) {
77     counter_ = static_cast<uint8_t>((counter_ + 1U) % 15);
78 }
79 
80 } // namespace profile01
81 } // namespace e2e
82 } // namespace vsomeip_v3
83