xref: /aosp_15_r20/external/webrtc/net/dcsctp/packet/error_cause/missing_mandatory_parameter_cause.cc (revision d9f758449e529ab9291ac668be2861e7a55c2422) 
1 /*
2  *  Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 #include "net/dcsctp/packet/error_cause/missing_mandatory_parameter_cause.h"
11 
12 #include <stddef.h>
13 
14 #include <cstdint>
15 #include <string>
16 #include <type_traits>
17 #include <vector>
18 
19 #include "absl/types/optional.h"
20 #include "api/array_view.h"
21 #include "net/dcsctp/common/str_join.h"
22 #include "net/dcsctp/packet/bounded_byte_reader.h"
23 #include "net/dcsctp/packet/bounded_byte_writer.h"
24 #include "net/dcsctp/packet/tlv_trait.h"
25 #include "rtc_base/logging.h"
26 #include "rtc_base/strings/string_builder.h"
27 
28 namespace dcsctp {
29 
30 // https://tools.ietf.org/html/rfc4960#section-3.3.10.2
31 
32 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
33 //  |     Cause Code=2              |      Cause Length=8+N*2       |
34 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
35 //  |                   Number of missing params=N                  |
36 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
37 //  |   Missing Param Type #1       |   Missing Param Type #2       |
38 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
39 //  |   Missing Param Type #N-1     |   Missing Param Type #N       |
40 //  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41 constexpr int MissingMandatoryParameterCause::kType;
42 
43 absl::optional<MissingMandatoryParameterCause>
Parse(rtc::ArrayView<const uint8_t> data)44 MissingMandatoryParameterCause::Parse(rtc::ArrayView<const uint8_t> data) {
45   absl::optional<BoundedByteReader<kHeaderSize>> reader = ParseTLV(data);
46   if (!reader.has_value()) {
47     return absl::nullopt;
48   }
49 
50   uint32_t count = reader->Load32<4>();
51   if (reader->variable_data_size() / kMissingParameterSize != count) {
52     RTC_DLOG(LS_WARNING) << "Invalid number of missing parameters";
53     return absl::nullopt;
54   }
55 
56   std::vector<uint16_t> missing_parameter_types;
57   missing_parameter_types.reserve(count);
58   for (uint32_t i = 0; i < count; ++i) {
59     BoundedByteReader<kMissingParameterSize> sub_reader =
60         reader->sub_reader<kMissingParameterSize>(i * kMissingParameterSize);
61 
62     missing_parameter_types.push_back(sub_reader.Load16<0>());
63   }
64   return MissingMandatoryParameterCause(missing_parameter_types);
65 }
66 
SerializeTo(std::vector<uint8_t> & out) const67 void MissingMandatoryParameterCause::SerializeTo(
68     std::vector<uint8_t>& out) const {
69   size_t variable_size =
70       missing_parameter_types_.size() * kMissingParameterSize;
71   BoundedByteWriter<kHeaderSize> writer = AllocateTLV(out, variable_size);
72 
73   writer.Store32<4>(missing_parameter_types_.size());
74 
75   for (size_t i = 0; i < missing_parameter_types_.size(); ++i) {
76     BoundedByteWriter<kMissingParameterSize> sub_writer =
77         writer.sub_writer<kMissingParameterSize>(i * kMissingParameterSize);
78 
79     sub_writer.Store16<0>(missing_parameter_types_[i]);
80   }
81 }
82 
ToString() const83 std::string MissingMandatoryParameterCause::ToString() const {
84   rtc::StringBuilder sb;
85   sb << "Missing Mandatory Parameter, missing_parameter_types="
86      << StrJoin(missing_parameter_types_, ",");
87   return sb.Release();
88 }
89 
90 }  // namespace dcsctp
91