ebpfProgram.h

/*
Copyright 2013-present Barefoot Networks, Inc.
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
 
    http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
 
#ifndef BACKENDS_EBPF_EBPFPROGRAM_H_
#define BACKENDS_EBPF_EBPFPROGRAM_H_
 
#include "codeGen.h"
#include "ebpfModel.h"
#include "ebpfObject.h"
#include "ebpfOptions.h"
#include "frontends/common/options.h"
#include "frontends/p4/evaluator/evaluator.h"
#include "frontends/p4/typeMap.h"
#include "ir/ir.h"
#include "target.h"
 
namespace EBPF {
 
class EBPFProgram;
class EBPFParser;
class EBPFControl;
class EBPFDeparser;
class EBPFTable;
class EBPFType;
 
class EBPFProgram : public EBPFObject {
 public:
    // The builder->target defines either TC or XDP target,
    // while for PSA-eBPF we may use both of them interchangeably.
    // This field stores the Target object that is unique per eBPF program (pipeline).
    const Target *progTarget;
    const EbpfOptions &options;
    const IR::P4Program *program;
    const IR::ToplevelBlock *toplevel;
    P4::ReferenceMap *refMap;
    P4::TypeMap *typeMap;
    EBPFParser *parser;
    EBPFControl *control;
    EBPFModel &model;
    EBPFDeparser *deparser;
 
    cstring endLabel, offsetVar, lengthVar, headerStartVar;
    cstring zeroKey, functionName, errorVar;
    cstring packetStartVar, packetEndVar, byteVar;
    cstring errorEnum;
    cstring license = "GPL"_cs;  
    cstring arrayIndexType = "u32"_cs;
 
    virtual bool build();  
 
    EBPFProgram(const EbpfOptions &options, const IR::P4Program *program, P4::ReferenceMap *refMap,
                P4::TypeMap *typeMap, const IR::ToplevelBlock *toplevel)
        : progTarget(nullptr),
          options(options),
          program(program),
          toplevel(toplevel),
          refMap(refMap),
          typeMap(typeMap),
          parser(nullptr),
          control(nullptr),
          model(EBPFModel::instance),
          deparser(nullptr) {
        // NB: offsetVar not used in eBPF backend - uBPF and TC only
        offsetVar = EBPFModel::reserved("packetOffsetInBits"_cs);
        zeroKey = EBPFModel::reserved("zero"_cs);
        functionName = EBPFModel::reserved("filter"_cs);
        errorVar = EBPFModel::reserved("errorCode"_cs);
        packetStartVar = EBPFModel::reserved("packetStart"_cs);
        packetEndVar = EBPFModel::reserved("packetEnd"_cs);
        headerStartVar = EBPFModel::reserved("headerStart"_cs);
        lengthVar = EBPFModel::reserved("pkt_len"_cs);
        byteVar = EBPFModel::reserved("byte"_cs);
        endLabel = EBPFModel::reserved("end"_cs);
        errorEnum = EBPFModel::reserved("errorCodes"_cs);
    }
 
 protected:
    virtual void emitPreamble(CodeBuilder *builder);
    virtual void emitTypes(CodeBuilder *builder);
    virtual void emitHeaderInstances(CodeBuilder *builder);
    virtual void emitLocalVariables(CodeBuilder *builder);
    virtual void emitPipeline(CodeBuilder *builder);
 
    virtual bool isLibraryMethod(cstring methodName);
 
 public:
    virtual void emitCommonPreamble(CodeBuilder *builder);
    virtual void emitGeneratedComment(CodeBuilder *builder);
    virtual void emitH(CodeBuilder *builder,
                       const std::filesystem::path &headerFile);  // emits C headers
    virtual void emitC(CodeBuilder *builder,
                       const std::filesystem::path &headerFile);  // emits C program
 
    DECLARE_TYPEINFO(EBPFProgram, EBPFObject);
};
 
}  // namespace EBPF
 
#endif /* BACKENDS_EBPF_EBPFPROGRAM_H_ */