/*
* Copyright (c) 2015 PLUMgrid, 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.
*/
#include <algorithm>
#include <fcntl.h>
#include <ftw.h>
#include <map>
#include <stdio.h>
#include <string>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <unistd.h>
#include <vector>
#include <linux/bpf.h>
#include <llvm/ADT/STLExtras.h>
#include <llvm/ExecutionEngine/MCJIT.h>
#include <llvm/ExecutionEngine/SectionMemoryManager.h>
#include <llvm/IRReader/IRReader.h>
#include <llvm/IR/IRBuilder.h>
#include <llvm/IR/IRPrintingPasses.h>
#include <llvm/IR/LegacyPassManager.h>
#include <llvm/IR/LLVMContext.h>
#include <llvm/IR/Module.h>
#include <llvm/IR/Verifier.h>
#include <llvm/Object/ObjectFile.h>
#include <llvm/Support/FormattedStream.h>
#include <llvm/Support/Host.h>
#include <llvm/Support/SourceMgr.h>
#include <llvm/Support/TargetSelect.h>
#include <llvm/Transforms/IPO.h>
#include <llvm/Transforms/IPO/PassManagerBuilder.h>
#include <llvm-c/Transforms/IPO.h>
#include "common.h"
#include "bcc_debug.h"
#include "bcc_exception.h"
#include "frontends/b/loader.h"
#include "frontends/clang/loader.h"
#include "frontends/clang/b_frontend_action.h"
#include "bpf_module.h"
#include "exported_files.h"
#include "kbuild_helper.h"
#include "libbpf.h"
namespace ebpf {
using std::get;
using std::make_tuple;
using std::map;
using std::move;
using std::string;
using std::tuple;
using std::unique_ptr;
using std::vector;
using namespace llvm;
const string BPFModule::FN_PREFIX = BPF_FN_PREFIX;
// Snooping class to remember the sections as the JIT creates them
class MyMemoryManager : public SectionMemoryManager {
public:
explicit MyMemoryManager(map<string, tuple<uint8_t *, uintptr_t>> *sections)
: sections_(sections) {
}
virtual ~MyMemoryManager() {}
uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID,
StringRef SectionName) override {
uint8_t *Addr = SectionMemoryManager::allocateCodeSection(Size, Alignment, SectionID, SectionName);
//printf("allocateCodeSection: %s Addr %p Size %ld Alignment %d SectionID %d\n",
// SectionName.str().c_str(), (void *)Addr, Size, Alignment, SectionID);
(*sections_)[SectionName.str()] = make_tuple(Addr, Size);
return Addr;
}
uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID, StringRef SectionName,
bool isReadOnly) override {
uint8_t *Addr = SectionMemoryManager::allocateDataSection(Size, Alignment, SectionID, SectionName, isReadOnly);
//printf("allocateDataSection: %s Addr %p Size %ld Alignment %d SectionID %d RO %d\n",
// SectionName.str().c_str(), (void *)Addr, Size, Alignment, SectionID, isReadOnly);
(*sections_)[SectionName.str()] = make_tuple(Addr, Size);
return Addr;
}
map<string, tuple<uint8_t *, uintptr_t>> *sections_;
};
BPFModule::BPFModule(unsigned flags, TableStorage *ts, bool rw_engine_enabled,
const std::string &maps_ns)
: flags_(flags),
rw_engine_enabled_(rw_engine_enabled),
used_b_loader_(false),
ctx_(new LLVMContext),
id_(std::to_string((uintptr_t)this)),
maps_ns_(maps_ns),
ts_(ts) {
InitializeNativeTarget();
InitializeNativeTargetAsmPrinter();
LLVMInitializeBPFTarget();
LLVMInitializeBPFTargetMC();
LLVMInitializeBPFTargetInfo();
LLVMInitializeBPFAsmPrinter();
#if LLVM_MAJOR_VERSION >= 6
LLVMInitializeBPFAsmParser();
if (flags & DEBUG_SOURCE)
LLVMInitializeBPFDisassembler();
#endif
LLVMLinkInMCJIT(); /* call empty function to force linking of MCJIT */
if (!ts_) {
local_ts_ = createSharedTableStorage();
ts_ = &*local_ts_;
}
func_src_ = ebpf::make_unique<FuncSource>();
}
static StatusTuple unimplemented_sscanf(const char *, void *) {
return StatusTuple(-1, "sscanf unimplemented");
}
static StatusTuple unimplemented_snprintf(char *, size_t, const void *) {
return StatusTuple(-1, "snprintf unimplemented");
}
BPFModule::~BPFModule() {
for (auto &v : tables_) {
v->key_sscanf = unimplemented_sscanf;
v->leaf_sscanf = unimplemented_sscanf;
v->key_snprintf = unimplemented_snprintf;
v->leaf_snprintf = unimplemented_snprintf;
}
if (!rw_engine_enabled_) {
for (auto section : sections_)
delete[] get<0>(section.second);
}
engine_.reset();
rw_engine_.reset();
ctx_.reset();
func_src_.reset();
ts_->DeletePrefix(Path({id_}));
}
static void debug_printf(Module *mod, IRBuilder<> &B, const string &fmt, vector<Value *> args) {
GlobalVariable *fmt_gvar = B.CreateGlobalString(fmt, "fmt");
args.insert(args.begin(), B.CreateInBoundsGEP(fmt_gvar, vector<Value *>({B.getInt64(0), B.getInt64(0)})));
args.insert(args.begin(), B.getInt64((uintptr_t)stderr));
Function *fprintf_fn = mod->getFunction("fprintf");
if (!fprintf_fn) {
vector<Type *> fprintf_fn_args({B.getInt64Ty(), B.getInt8PtrTy()});
FunctionType *fprintf_fn_type = FunctionType::get(B.getInt32Ty(), fprintf_fn_args, /*isvarArg=*/true);
fprintf_fn = Function::Create(fprintf_fn_type, GlobalValue::ExternalLinkage, "fprintf", mod);
fprintf_fn->setCallingConv(CallingConv::C);
fprintf_fn->addFnAttr(Attribute::NoUnwind);
}
B.CreateCall(fprintf_fn, args);
}
static void finish_sscanf(IRBuilder<> &B, vector<Value *> *args, string *fmt,
const map<string, Value *> &locals, bool exact_args) {
// fmt += "%n";
// int nread = 0;
// int n = sscanf(s, fmt, args..., &nread);
// if (n < 0) return -1;
// s = &s[nread];
Value *sptr = locals.at("sptr");
Value *nread = locals.at("nread");
Function *cur_fn = B.GetInsertBlock()->getParent();
Function *sscanf_fn = B.GetInsertBlock()->getModule()->getFunction("sscanf");
*fmt += "%n";
B.CreateStore(B.getInt32(0), nread);
GlobalVariable *fmt_gvar = B.CreateGlobalString(*fmt, "fmt");
(*args)[1] = B.CreateInBoundsGEP(fmt_gvar, {B.getInt64(0), B.getInt64(0)});
(*args)[0] = B.CreateLoad(sptr);
args->push_back(nread);
CallInst *call = B.CreateCall(sscanf_fn, *args);
call->setTailCall(true);
BasicBlock *label_true = BasicBlock::Create(B.getContext(), "", cur_fn);
BasicBlock *label_false = BasicBlock::Create(B.getContext(), "", cur_fn);
// exact_args means fail if don't consume exact number of "%" inputs
// exact_args is disabled for string parsing (empty case)
Value *cond = exact_args ? B.CreateICmpNE(call, B.getInt32(args->size() - 3))
: B.CreateICmpSLT(call, B.getInt32(0));
B.CreateCondBr(cond, label_true, label_false);
B.SetInsertPoint(label_true);
B.CreateRet(B.getInt32(-1));
B.SetInsertPoint(label_false);
// s = &s[nread];
B.CreateStore(
B.CreateInBoundsGEP(B.CreateLoad(sptr), B.CreateLoad(nread, true)), sptr);
args->resize(2);
fmt->clear();
}
// recursive helper to capture the arguments
static void parse_type(IRBuilder<> &B, vector<Value *> *args, string *fmt,
Type *type, Value *out,
const map<string, Value *> &locals, bool is_writer) {
if (StructType *st = dyn_cast<StructType>(type)) {
*fmt += "{ ";
unsigned idx = 0;
for (auto field : st->elements()) {
parse_type(B, args, fmt, field, B.CreateStructGEP(type, out, idx++),
locals, is_writer);
*fmt += " ";
}
*fmt += "}";
} else if (ArrayType *at = dyn_cast<ArrayType>(type)) {
if (at->getElementType() == B.getInt8Ty()) {
// treat i8[] as a char string instead of as an array of u8's
if (is_writer) {
*fmt += "\"%s\"";
args->push_back(out);
} else {
// When reading strings, scanf doesn't support empty "", so we need to
// break this up into multiple scanf calls. To understand it, let's take
// an example:
// struct Event {
// u32 a;
// struct {
// char x[64];
// int y;
// } b[2];
// u32 c;
// };
// The writer string would look like:
// "{ 0x%x [ { \"%s\" 0x%x } { \"%s\" 0x%x } ] 0x%x }"
// But the reader string needs to restart at each \"\".
// reader0(const char *s, struct Event *val) {
// int nread, rc;
// nread = 0;
// rc = sscanf(s, "{ %i [ { \"%n", &val->a, &nread);
// if (rc != 1) return -1;
// s += nread; nread = 0;
// rc = sscanf(s, "%[^\"]%n", &val->b[0].x, &nread);
// if (rc < 0) return -1;
// s += nread; nread = 0;
// rc = sscanf(s, "\" %i } { \"%n", &val->b[0].y, &nread);
// if (rc != 1) return -1;
// s += nread; nread = 0;
// rc = sscanf(s, "%[^\"]%n", &val->b[1].x, &nread);
// if (rc < 0) return -1;
// s += nread; nread = 0;
// rc = sscanf(s, "\" %i } ] %i }%n", &val->b[1].y, &val->c, &nread);
// if (rc != 2) return -1;
// s += nread; nread = 0;
// return 0;
// }
*fmt += "\"";
finish_sscanf(B, args, fmt, locals, true);
*fmt = "%[^\"]";
args->push_back(out);
finish_sscanf(B, args, fmt, locals, false);
*fmt = "\"";
}
} else {
*fmt += "[ ";
for (size_t i = 0; i < at->getNumElements(); ++i) {
parse_type(B, args, fmt, at->getElementType(),
B.CreateStructGEP(type, out, i), locals, is_writer);
*fmt += " ";
}
*fmt += "]";
}
} else if (isa<PointerType>(type)) {
*fmt += "0xl";
if (is_writer)
*fmt += "x";
else
*fmt += "i";
} else if (IntegerType *it = dyn_cast<IntegerType>(type)) {
if (is_writer)
*fmt += "0x";
if (it->getBitWidth() <= 8)
*fmt += "%hh";
else if (it->getBitWidth() <= 16)
*fmt += "%h";
else if (it->getBitWidth() <= 32)
*fmt += "%";
else
*fmt += "%l";
if (is_writer)
*fmt += "x";
else
*fmt += "i";
args->push_back(is_writer ? B.CreateLoad(out) : out);
}
}
// make_reader generates a dynamic function in the instruction set of the host
// (not bpf) that is able to convert c-strings in the pretty-print format of
// make_writer back into binary representations. The encoding of the string
// takes the llvm ir structure format, which closely maps the c structure but
// not exactly (no support for unions for instance).
// The general algorithm is:
// pod types (u8..u64) <= %i
// array types
// u8[] no nested quotes :( <= "..."
// !u8[] <= [ %i %i ... ]
// struct types
// struct { u8 a; u64 b; } <= { %i %i }
// nesting is supported
// struct { struct { u8 a[]; }; } <= { "" }
// struct { struct { u64 a[]; }; } <= { [ %i %i .. ] }
string BPFModule::make_reader(Module *mod, Type *type) {
auto fn_it = readers_.find(type);
if (fn_it != readers_.end())
return fn_it->second;
// int read(const char *in, Type *out) {
// int n = sscanf(in, "{ %i ... }", &out->field1, ...);
// if (n != num_fields) return -1;
// return 0;
// }
IRBuilder<> B(*ctx_);
FunctionType *sscanf_fn_type = FunctionType::get(
B.getInt32Ty(), {B.getInt8PtrTy(), B.getInt8PtrTy()}, /*isVarArg=*/true);
Function *sscanf_fn = mod->getFunction("sscanf");
if (!sscanf_fn) {
sscanf_fn = Function::Create(sscanf_fn_type, GlobalValue::ExternalLinkage,
"sscanf", mod);
sscanf_fn->setCallingConv(CallingConv::C);
sscanf_fn->addFnAttr(Attribute::NoUnwind);
}
string name = "reader" + std::to_string(readers_.size());
vector<Type *> fn_args({B.getInt8PtrTy(), PointerType::getUnqual(type)});
FunctionType *fn_type = FunctionType::get(B.getInt32Ty(), fn_args, /*isVarArg=*/false);
Function *fn =
Function::Create(fn_type, GlobalValue::ExternalLinkage, name, mod);
auto arg_it = fn->arg_begin();
Argument *arg_in = &*arg_it;
++arg_it;
arg_in->setName("in");
Argument *arg_out = &*arg_it;
++arg_it;
arg_out->setName("out");
BasicBlock *label_entry = BasicBlock::Create(*ctx_, "entry", fn);
B.SetInsertPoint(label_entry);
Value *nread = B.CreateAlloca(B.getInt32Ty());
Value *sptr = B.CreateAlloca(B.getInt8PtrTy());
map<string, Value *> locals{{"nread", nread}, {"sptr", sptr}};
B.CreateStore(arg_in, sptr);
vector<Value *> args({nullptr, nullptr});
string fmt;
parse_type(B, &args, &fmt, type, arg_out, locals, false);
if (0)
debug_printf(mod, B, "%p %p\n", vector<Value *>({arg_in, arg_out}));
finish_sscanf(B, &args, &fmt, locals, true);
B.CreateRet(B.getInt32(0));
readers_[type] = name;
return name;
}
// make_writer generates a dynamic function in the instruction set of the host
// (not bpf) that is able to pretty-print key/leaf entries as a c-string. The
// encoding of the string takes the llvm ir structure format, which closely maps
// the c structure but not exactly (no support for unions for instance).
// The general algorithm is:
// pod types (u8..u64) => 0x%x
// array types
// u8[] => "..."
// !u8[] => [ 0x%x 0x%x ... ]
// struct types
// struct { u8 a; u64 b; } => { 0x%x 0x%x }
// nesting is supported
// struct { struct { u8 a[]; }; } => { "" }
// struct { struct { u64 a[]; }; } => { [ 0x%x 0x%x .. ] }
string BPFModule::make_writer(Module *mod, Type *type) {
auto fn_it = writers_.find(type);
if (fn_it != writers_.end())
return fn_it->second;
// int write(int len, char *out, Type *in) {
// return snprintf(out, len, "{ %i ... }", out->field1, ...);
// }
IRBuilder<> B(*ctx_);
string name = "writer" + std::to_string(writers_.size());
vector<Type *> fn_args({B.getInt8PtrTy(), B.getInt64Ty(), PointerType::getUnqual(type)});
FunctionType *fn_type = FunctionType::get(B.getInt32Ty(), fn_args, /*isVarArg=*/false);
Function *fn =
Function::Create(fn_type, GlobalValue::ExternalLinkage, name, mod);
auto arg_it = fn->arg_begin();
Argument *arg_out = &*arg_it;
++arg_it;
arg_out->setName("out");
Argument *arg_len = &*arg_it;
++arg_it;
arg_len->setName("len");
Argument *arg_in = &*arg_it;
++arg_it;
arg_in->setName("in");
BasicBlock *label_entry = BasicBlock::Create(*ctx_, "entry", fn);
B.SetInsertPoint(label_entry);
map<string, Value *> locals{
{"nread", B.CreateAlloca(B.getInt64Ty())},
};
vector<Value *> args({arg_out, B.CreateZExt(arg_len, B.getInt64Ty()), nullptr});
string fmt;
parse_type(B, &args, &fmt, type, arg_in, locals, true);
GlobalVariable *fmt_gvar = B.CreateGlobalString(fmt, "fmt");
args[2] = B.CreateInBoundsGEP(fmt_gvar, vector<Value *>({B.getInt64(0), B.getInt64(0)}));
if (0)
debug_printf(mod, B, "%d %p %p\n", vector<Value *>({arg_len, arg_out, arg_in}));
vector<Type *> snprintf_fn_args({B.getInt8PtrTy(), B.getInt64Ty(), B.getInt8PtrTy()});
FunctionType *snprintf_fn_type = FunctionType::get(B.getInt32Ty(), snprintf_fn_args, /*isVarArg=*/true);
Function *snprintf_fn = mod->getFunction("snprintf");
if (!snprintf_fn)
snprintf_fn = Function::Create(snprintf_fn_type, GlobalValue::ExternalLinkage, "snprintf", mod);
snprintf_fn->setCallingConv(CallingConv::C);
snprintf_fn->addFnAttr(Attribute::NoUnwind);
CallInst *call = B.CreateCall(snprintf_fn, args);
call->setTailCall(true);
B.CreateRet(call);
writers_[type] = name;
return name;
}
unique_ptr<ExecutionEngine> BPFModule::finalize_rw(unique_ptr<Module> m) {
Module *mod = &*m;
run_pass_manager(*mod);
string err;
EngineBuilder builder(move(m));
builder.setErrorStr(&err);
builder.setUseOrcMCJITReplacement(false);
auto engine = unique_ptr<ExecutionEngine>(builder.create());
if (!engine)
fprintf(stderr, "Could not create ExecutionEngine: %s\n", err.c_str());
return engine;
}
// load an entire c file as a module
int BPFModule::load_cfile(const string &file, bool in_memory, const char *cflags[], int ncflags) {
ClangLoader clang_loader(&*ctx_, flags_);
if (clang_loader.parse(&mod_, *ts_, file, in_memory, cflags, ncflags, id_,
*func_src_, mod_src_, maps_ns_))
return -1;
return 0;
}
// NOTE: this is a duplicate of the above, but planning to deprecate if we
// settle on clang as the frontend
// Load in a pre-built list of functions into the initial Module object, then
// build an ExecutionEngine.
int BPFModule::load_includes(const string &text) {
ClangLoader clang_loader(&*ctx_, flags_);
if (clang_loader.parse(&mod_, *ts_, text, true, nullptr, 0, "", *func_src_,
mod_src_, ""))
return -1;
return 0;
}
void BPFModule::annotate_light() {
for (auto fn = mod_->getFunctionList().begin(); fn != mod_->getFunctionList().end(); ++fn)
if (!fn->hasFnAttribute(Attribute::NoInline))
fn->addFnAttr(Attribute::AlwaysInline);
size_t id = 0;
Path path({id_});
for (auto it = ts_->lower_bound(path), up = ts_->upper_bound(path); it != up; ++it) {
TableDesc &table = it->second;
tables_.push_back(&it->second);
table_names_[table.name] = id++;
}
}
int BPFModule::annotate() {
for (auto fn = mod_->getFunctionList().begin(); fn != mod_->getFunctionList().end(); ++fn)
if (!fn->hasFnAttribute(Attribute::NoInline))
fn->addFnAttr(Attribute::AlwaysInline);
// separate module to hold the reader functions
auto m = ebpf::make_unique<Module>("sscanf", *ctx_);
size_t id = 0;
Path path({id_});
for (auto it = ts_->lower_bound(path), up = ts_->upper_bound(path); it != up; ++it) {
TableDesc &table = it->second;
tables_.push_back(&it->second);
table_names_[table.name] = id++;
GlobalValue *gvar = mod_->getNamedValue(table.name);
if (!gvar) continue;
if (PointerType *pt = dyn_cast<PointerType>(gvar->getType())) {
if (StructType *st = dyn_cast<StructType>(pt->getElementType())) {
if (st->getNumElements() < 2) continue;
Type *key_type = st->elements()[0];
Type *leaf_type = st->elements()[1];
using std::placeholders::_1;
using std::placeholders::_2;
using std::placeholders::_3;
table.key_sscanf = std::bind(&BPFModule::sscanf, this,
make_reader(&*m, key_type), _1, _2);
table.leaf_sscanf = std::bind(&BPFModule::sscanf, this,
make_reader(&*m, leaf_type), _1, _2);
table.key_snprintf = std::bind(&BPFModule::snprintf, this,
make_writer(&*m, key_type), _1, _2, _3);
table.leaf_snprintf =
std::bind(&BPFModule::snprintf, this, make_writer(&*m, leaf_type),
_1, _2, _3);
}
}
}
rw_engine_ = finalize_rw(move(m));
if (!rw_engine_)
return -1;
return 0;
}
StatusTuple BPFModule::sscanf(string fn_name, const char *str, void *val) {
if (!rw_engine_enabled_)
return StatusTuple(-1, "rw_engine not enabled");
auto fn =
(int (*)(const char *, void *))rw_engine_->getFunctionAddress(fn_name);
if (!fn)
return StatusTuple(-1, "sscanf not available");
int rc = fn(str, val);
if (rc < 0)
return StatusTuple(rc, "error in sscanf: %s", std::strerror(errno));
return StatusTuple(rc);
}
StatusTuple BPFModule::snprintf(string fn_name, char *str, size_t sz,
const void *val) {
if (!rw_engine_enabled_)
return StatusTuple(-1, "rw_engine not enabled");
auto fn = (int (*)(char *, size_t,
const void *))rw_engine_->getFunctionAddress(fn_name);
if (!fn)
return StatusTuple(-1, "snprintf not available");
int rc = fn(str, sz, val);
if (rc < 0)
return StatusTuple(rc, "error in snprintf: %s", std::strerror(errno));
if ((size_t)rc == sz)
return StatusTuple(-1, "buffer of size %zd too small", sz);
return StatusTuple(0);
}
void BPFModule::dump_ir(Module &mod) {
legacy::PassManager PM;
PM.add(createPrintModulePass(errs()));
PM.run(mod);
}
int BPFModule::run_pass_manager(Module &mod) {
if (verifyModule(mod, &errs())) {
if (flags_ & DEBUG_LLVM_IR)
dump_ir(mod);
return -1;
}
legacy::PassManager PM;
PassManagerBuilder PMB;
PMB.OptLevel = 3;
PM.add(createFunctionInliningPass());
/*
* llvm < 4.0 needs
* PM.add(createAlwaysInlinerPass());
* llvm >= 4.0 needs
* PM.add(createAlwaysInlinerLegacyPass());
* use below 'stable' workaround
*/
LLVMAddAlwaysInlinerPass(reinterpret_cast<LLVMPassManagerRef>(&PM));
PMB.populateModulePassManager(PM);
if (flags_ & DEBUG_LLVM_IR)
PM.add(createPrintModulePass(outs()));
PM.run(mod);
return 0;
}
int BPFModule::finalize() {
Module *mod = &*mod_;
std::map<std::string, std::tuple<uint8_t *, uintptr_t>> tmp_sections,
*sections_p;
mod->setTargetTriple("bpf-pc-linux");
sections_p = rw_engine_enabled_ ? §ions_ : &tmp_sections;
string err;
EngineBuilder builder(move(mod_));
builder.setErrorStr(&err);
builder.setMCJITMemoryManager(ebpf::make_unique<MyMemoryManager>(sections_p));
builder.setMArch("bpf");
builder.setUseOrcMCJITReplacement(false);
engine_ = unique_ptr<ExecutionEngine>(builder.create());
if (!engine_) {
fprintf(stderr, "Could not create ExecutionEngine: %s\n", err.c_str());
return -1;
}
if (flags_ & DEBUG_SOURCE)
engine_->setProcessAllSections(true);
if (int rc = run_pass_manager(*mod))
return rc;
engine_->finalizeObject();
if (flags_ & DEBUG_SOURCE) {
SourceDebugger src_debugger(mod, *sections_p, FN_PREFIX, mod_src_,
src_dbg_fmap_);
src_debugger.dump();
}
if (!rw_engine_enabled_) {
// Setup sections_ correctly and then free llvm internal memory
for (auto section : tmp_sections) {
auto fname = section.first;
uintptr_t size = get<1>(section.second);
uint8_t *tmp_p = NULL;
// Only copy data for non-map sections
if (strncmp("maps/", section.first.c_str(), 5)) {
uint8_t *addr = get<0>(section.second);
tmp_p = new uint8_t[size];
memcpy(tmp_p, addr, size);
}
sections_[fname] = make_tuple(tmp_p, size);
}
engine_.reset();
ctx_.reset();
}
// give functions an id
for (auto section : sections_)
if (!strncmp(FN_PREFIX.c_str(), section.first.c_str(), FN_PREFIX.size()))
function_names_.push_back(section.first);
return 0;
}
size_t BPFModule::num_functions() const {
return function_names_.size();
}
const char * BPFModule::function_name(size_t id) const {
if (id >= function_names_.size())
return nullptr;
return function_names_[id].c_str() + FN_PREFIX.size();
}
uint8_t * BPFModule::function_start(size_t id) const {
if (id >= function_names_.size())
return nullptr;
auto section = sections_.find(function_names_[id]);
if (section == sections_.end())
return nullptr;
return get<0>(section->second);
}
uint8_t * BPFModule::function_start(const string &name) const {
auto section = sections_.find(FN_PREFIX + name);
if (section == sections_.end())
return nullptr;
return get<0>(section->second);
}
const char * BPFModule::function_source(const string &name) const {
return func_src_->src(name);
}
const char * BPFModule::function_source_rewritten(const string &name) const {
return func_src_->src_rewritten(name);
}
int BPFModule::annotate_prog_tag(const string &name, int prog_fd,
struct bpf_insn *insns, int prog_len) {
unsigned long long tag1, tag2;
int err;
err = bpf_prog_compute_tag(insns, prog_len, &tag1);
if (err)
return err;
err = bpf_prog_get_tag(prog_fd, &tag2);
if (err)
return err;
if (tag1 != tag2) {
fprintf(stderr, "prog tag mismatch %llx %llx\n", tag1, tag2);
return -1;
}
err = mkdir(BCC_PROG_TAG_DIR, 0777);
if (err && errno != EEXIST) {
fprintf(stderr, "cannot create " BCC_PROG_TAG_DIR "\n");
return -1;
}
char buf[128];
::snprintf(buf, sizeof(buf), BCC_PROG_TAG_DIR "/bpf_prog_%llx", tag1);
err = mkdir(buf, 0777);
if (err && errno != EEXIST) {
fprintf(stderr, "cannot create %s\n", buf);
return -1;
}
::snprintf(buf, sizeof(buf), BCC_PROG_TAG_DIR "/bpf_prog_%llx/%s.c",
tag1, name.data());
FileDesc fd(open(buf, O_CREAT | O_WRONLY | O_TRUNC, 0644));
if (fd < 0) {
fprintf(stderr, "cannot create %s\n", buf);
return -1;
}
const char *src = function_source(name);
write(fd, src, strlen(src));
::snprintf(buf, sizeof(buf), BCC_PROG_TAG_DIR "/bpf_prog_%llx/%s.rewritten.c",
tag1, name.data());
fd = open(buf, O_CREAT | O_WRONLY | O_TRUNC, 0644);
if (fd < 0) {
fprintf(stderr, "cannot create %s\n", buf);
return -1;
}
src = function_source_rewritten(name);
write(fd, src, strlen(src));
if (!src_dbg_fmap_[name].empty()) {
::snprintf(buf, sizeof(buf), BCC_PROG_TAG_DIR "/bpf_prog_%llx/%s.dis.txt",
tag1, name.data());
fd = open(buf, O_CREAT | O_WRONLY | O_TRUNC, 0644);
if (fd < 0) {
fprintf(stderr, "cannot create %s\n", buf);
return -1;
}
const char *src = src_dbg_fmap_[name].c_str();
write(fd, src, strlen(src));
}
return 0;
}
size_t BPFModule::function_size(size_t id) const {
if (id >= function_names_.size())
return 0;
auto section = sections_.find(function_names_[id]);
if (section == sections_.end())
return 0;
return get<1>(section->second);
}
size_t BPFModule::function_size(const string &name) const {
auto section = sections_.find(FN_PREFIX + name);
if (section == sections_.end())
return 0;
return get<1>(section->second);
}
char * BPFModule::license() const {
auto section = sections_.find("license");
if (section == sections_.end())
return nullptr;
return (char *)get<0>(section->second);
}
unsigned BPFModule::kern_version() const {
auto section = sections_.find("version");
if (section == sections_.end())
return 0;
return *(unsigned *)get<0>(section->second);
}
size_t BPFModule::num_tables() const { return tables_.size(); }
size_t BPFModule::table_id(const string &name) const {
auto it = table_names_.find(name);
if (it == table_names_.end()) return ~0ull;
return it->second;
}
int BPFModule::table_fd(const string &name) const {
return table_fd(table_id(name));
}
int BPFModule::table_fd(size_t id) const {
if (id >= tables_.size())
return -1;
return tables_[id]->fd;
}
int BPFModule::table_type(const string &name) const {
return table_type(table_id(name));
}
int BPFModule::table_type(size_t id) const {
if (id >= tables_.size())
return -1;
return tables_[id]->type;
}
size_t BPFModule::table_max_entries(const string &name) const {
return table_max_entries(table_id(name));
}
size_t BPFModule::table_max_entries(size_t id) const {
if (id >= tables_.size())
return 0;
return tables_[id]->max_entries;
}
int BPFModule::table_flags(const string &name) const {
return table_flags(table_id(name));
}
int BPFModule::table_flags(size_t id) const {
if (id >= tables_.size())
return -1;
return tables_[id]->flags;
}
const char * BPFModule::table_name(size_t id) const {
if (id >= tables_.size())
return nullptr;
return tables_[id]->name.c_str();
}
const char * BPFModule::table_key_desc(size_t id) const {
if (used_b_loader_) return nullptr;
if (id >= tables_.size())
return nullptr;
return tables_[id]->key_desc.c_str();
}
const char * BPFModule::table_key_desc(const string &name) const {
return table_key_desc(table_id(name));
}
const char * BPFModule::table_leaf_desc(size_t id) const {
if (used_b_loader_) return nullptr;
if (id >= tables_.size())
return nullptr;
return tables_[id]->leaf_desc.c_str();
}
const char * BPFModule::table_leaf_desc(const string &name) const {
return table_leaf_desc(table_id(name));
}
size_t BPFModule::table_key_size(size_t id) const {
if (id >= tables_.size())
return 0;
return tables_[id]->key_size;
}
size_t BPFModule::table_key_size(const string &name) const {
return table_key_size(table_id(name));
}
size_t BPFModule::table_leaf_size(size_t id) const {
if (id >= tables_.size())
return 0;
return tables_[id]->leaf_size;
}
size_t BPFModule::table_leaf_size(const string &name) const {
return table_leaf_size(table_id(name));
}
struct TableIterator {
TableIterator(size_t key_size, size_t leaf_size)
: key(new uint8_t[key_size]), leaf(new uint8_t[leaf_size]) {
}
unique_ptr<uint8_t[]> key;
unique_ptr<uint8_t[]> leaf;
uint8_t keyb[512];
};
int BPFModule::table_key_printf(size_t id, char *buf, size_t buflen, const void *key) {
if (id >= tables_.size())
return -1;
const TableDesc &desc = *tables_[id];
StatusTuple rc = desc.key_snprintf(buf, buflen, key);
if (rc.code() < 0) {
fprintf(stderr, "%s\n", rc.msg().c_str());
return -1;
}
return 0;
}
int BPFModule::table_leaf_printf(size_t id, char *buf, size_t buflen, const void *leaf) {
if (id >= tables_.size())
return -1;
const TableDesc &desc = *tables_[id];
StatusTuple rc = desc.leaf_snprintf(buf, buflen, leaf);
if (rc.code() < 0) {
fprintf(stderr, "%s\n", rc.msg().c_str());
return -1;
}
return 0;
}
int BPFModule::table_key_scanf(size_t id, const char *key_str, void *key) {
if (id >= tables_.size())
return -1;
const TableDesc &desc = *tables_[id];
StatusTuple rc = desc.key_sscanf(key_str, key);
if (rc.code() < 0) {
fprintf(stderr, "%s\n", rc.msg().c_str());
return -1;
}
return 0;
}
int BPFModule::table_leaf_scanf(size_t id, const char *leaf_str, void *leaf) {
if (id >= tables_.size())
return -1;
const TableDesc &desc = *tables_[id];
StatusTuple rc = desc.leaf_sscanf(leaf_str, leaf);
if (rc.code() < 0) {
fprintf(stderr, "%s\n", rc.msg().c_str());
return -1;
}
return 0;
}
// load a B file, which comes in two parts
int BPFModule::load_b(const string &filename, const string &proto_filename) {
if (!sections_.empty()) {
fprintf(stderr, "Program already initialized\n");
return -1;
}
if (filename.empty() || proto_filename.empty()) {
fprintf(stderr, "Invalid filenames\n");
return -1;
}
// Helpers are inlined in the following file (C). Load the definitions and
// pass the partially compiled module to the B frontend to continue with.
auto helpers_h = ExportedFiles::headers().find("/virtual/include/bcc/helpers.h");
if (helpers_h == ExportedFiles::headers().end()) {
fprintf(stderr, "Internal error: missing bcc/helpers.h");
return -1;
}
if (int rc = load_includes(helpers_h->second))
return rc;
BLoader b_loader(flags_);
used_b_loader_ = true;
if (int rc = b_loader.parse(&*mod_, filename, proto_filename, *ts_, id_,
maps_ns_))
return rc;
if (rw_engine_enabled_) {
if (int rc = annotate())
return rc;
} else {
annotate_light();
}
if (int rc = finalize())
return rc;
return 0;
}
// load a C file
int BPFModule::load_c(const string &filename, const char *cflags[], int ncflags) {
if (!sections_.empty()) {
fprintf(stderr, "Program already initialized\n");
return -1;
}
if (filename.empty()) {
fprintf(stderr, "Invalid filename\n");
return -1;
}
if (int rc = load_cfile(filename, false, cflags, ncflags))
return rc;
if (rw_engine_enabled_) {
if (int rc = annotate())
return rc;
} else {
annotate_light();
}
if (int rc = finalize())
return rc;
return 0;
}
// load a C text string
int BPFModule::load_string(const string &text, const char *cflags[], int ncflags) {
if (!sections_.empty()) {
fprintf(stderr, "Program already initialized\n");
return -1;
}
if (int rc = load_cfile(text, true, cflags, ncflags))
return rc;
if (rw_engine_enabled_) {
if (int rc = annotate())
return rc;
} else {
annotate_light();
}
if (int rc = finalize())
return rc;
return 0;
}
} // namespace ebpf