1 /*
2  * Copyright 2019 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "fields/payload_field.h"
18 
19 #include "util.h"
20 
21 const std::string PayloadField::kFieldType = "PayloadField";
22 
PayloadField(std::string modifier,ParseLocation loc)23 PayloadField::PayloadField(std::string modifier, ParseLocation loc)
24     : PacketField("payload", loc), size_field_(nullptr), size_modifier_(modifier) {}
25 
SetSizeField(const SizeField * size_field)26 void PayloadField::SetSizeField(const SizeField* size_field) {
27   if (size_field_ != nullptr) {
28     ERROR(this, size_field_, size_field)
29             << "The size field for the payload has already been assigned.";
30   }
31 
32   size_field_ = size_field;
33 }
34 
GetFieldType() const35 const std::string& PayloadField::GetFieldType() const { return PayloadField::kFieldType; }
36 
GetSize() const37 Size PayloadField::GetSize() const {
38   if (size_field_ == nullptr) {
39     if (!size_modifier_.empty()) {
40       ERROR(this) << "Missing size field for payload with size modifier.";
41     }
42     return Size();
43   }
44 
45   std::string dynamic_size =
46           "(Get" + util::UnderscoreToCamelCase(size_field_->GetName()) + "() * 8)";
47   if (!size_modifier_.empty()) {
48     dynamic_size += "- (" + size_modifier_.substr(1) + " * 8)";
49   }
50 
51   return dynamic_size;
52 }
53 
GetDataType() const54 std::string PayloadField::GetDataType() const { return "PacketView"; }
55 
GenExtractor(std::ostream &,int,bool) const56 void PayloadField::GenExtractor(std::ostream&, int, bool) const {
57   ERROR(this) << __func__ << " should never be called. ";
58 }
59 
GetGetterFunctionName() const60 std::string PayloadField::GetGetterFunctionName() const { return "GetPayload"; }
61 
GenGetter(std::ostream & s,Size start_offset,Size end_offset) const62 void PayloadField::GenGetter(std::ostream& s, Size start_offset, Size end_offset) const {
63   s << "PacketView<kLittleEndian> " << GetGetterFunctionName() << "() const {";
64   s << "ASSERT(was_validated_);";
65   s << "size_t end_index = size();";
66   s << "auto to_bound = begin();";
67   GenBounds(s, start_offset, end_offset, GetSize());
68   s << "return GetLittleEndianSubview(field_begin, field_end);";
69   s << "}\n\n";
70 }
71 
GetBuilderParameterType() const72 std::string PayloadField::GetBuilderParameterType() const {
73   return "std::unique_ptr<BasePacketBuilder>";
74 }
75 
BuilderParameterMustBeMoved() const76 bool PayloadField::BuilderParameterMustBeMoved() const { return true; }
77 
GenBuilderParameterFromView(std::ostream & s) const78 void PayloadField::GenBuilderParameterFromView(std::ostream& s) const {
79   s << "std::make_unique<RawBuilder>(std::vector<uint8_t>(view.GetPayload().begin(), "
80        "view.GetPayload().end()))";
81 }
82 
HasParameterValidator() const83 bool PayloadField::HasParameterValidator() const { return false; }
84 
GenParameterValidator(std::ostream &) const85 void PayloadField::GenParameterValidator(std::ostream&) const {
86   // There is no validation needed for a payload
87 }
88 
GenInserter(std::ostream &) const89 void PayloadField::GenInserter(std::ostream&) const {
90   ERROR() << __func__ << " Should never be called.";
91 }
92 
GenValidator(std::ostream &) const93 void PayloadField::GenValidator(std::ostream&) const {
94   // Do nothing
95 }
96 
GenStringRepresentation(std::ostream & s,std::string) const97 void PayloadField::GenStringRepresentation(std::ostream& s, std::string) const {
98   // TODO: we should parse the child packets
99   s << "\"PAYLOAD[]\"";
100 }
101