1 // Copyright 2020 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://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, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14
15 // clang-format off
16 #include "pw_rpc/internal/log_config.h" // PW_LOG_* macros must be first.
17
18 #include "pw_rpc/internal/channel.h"
19 // clang-format on
20
21 #include "pw_assert/check.h"
22 #include "pw_bytes/span.h"
23 #include "pw_log/log.h"
24 #include "pw_protobuf/decoder.h"
25 #include "pw_protobuf/find.h"
26 #include "pw_rpc/internal/config.h"
27 #include "pw_rpc/internal/encoding_buffer.h"
28 #include "pw_rpc/internal/packet.pwpb.h"
29
30 using pw::rpc::internal::pwpb::RpcPacket::Fields;
31
32 namespace pw::rpc {
33 namespace internal {
34
OverwriteChannelId(ByteSpan rpc_packet,uint32_t channel_id_under_128)35 Status OverwriteChannelId(ByteSpan rpc_packet, uint32_t channel_id_under_128) {
36 Result<ConstByteSpan> raw_field =
37 protobuf::FindRaw(rpc_packet, Fields::kChannelId);
38 if (!raw_field.ok()) {
39 return Status::DataLoss(); // Unexpected packet format
40 }
41 if (raw_field->size() != 1u) {
42 return Status::OutOfRange();
43 }
44 const_cast<std::byte*>(raw_field->data())[0] =
45 static_cast<std::byte>(channel_id_under_128);
46 return OkStatus();
47 }
48
49 } // namespace internal
50
ExtractChannelId(ConstByteSpan packet)51 Result<uint32_t> ExtractChannelId(ConstByteSpan packet) {
52 protobuf::Decoder decoder(packet);
53
54 while (decoder.Next().ok()) {
55 if (static_cast<Fields>(decoder.FieldNumber()) != Fields::kChannelId) {
56 continue;
57 }
58 uint32_t channel_id;
59 PW_TRY(decoder.ReadUint32(&channel_id));
60 return channel_id;
61 }
62
63 return Status::DataLoss();
64 }
65
66 namespace internal {
67
Send(const Packet & packet)68 Status Channel::Send(const Packet& packet) {
69 ByteSpan buffer = encoding_buffer.GetPacketBuffer(packet.payload().size());
70 Result encoded = packet.Encode(buffer);
71
72 if (!encoded.ok()) {
73 encoding_buffer.Release();
74 PW_LOG_ERROR(
75 "Failed to encode RPC packet type %u to channel %u buffer, status %u",
76 static_cast<unsigned>(packet.type()),
77 static_cast<unsigned>(id()),
78 encoded.status().code());
79 return Status::Internal();
80 }
81
82 Status sent = output().Send(encoded.value());
83 encoding_buffer.Release();
84
85 if (!sent.ok()) {
86 PW_LOG_DEBUG("Channel %u failed to send packet with status %u",
87 static_cast<unsigned>(id()),
88 sent.code());
89
90 return Status::Unknown();
91 }
92 return OkStatus();
93 }
94
95 } // namespace internal
96 } // namespace pw::rpc
97