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Commit 02bf6819 authored by 4ast's avatar 4ast
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Merge pull request #125 from iovisor/bblanco_dev 

Add printf for key/leaf and fix trace_printk bug
parents 3381c792 a328d238
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Showing with 212 additions and 40 deletions
src/cc/bpf_common.cc
View file @ 02bf6819
......@@ -182,4 +182,15 @@ int bpf_table_update_id(void *program, size_t id, const char *key, const char *l
return mod->table_update(id, key, leaf);
}
int bpf_table_key_snprintf(void *program, size_t id, char *buf, size_t buflen, const void *key) {
auto mod = static_cast<ebpf::BPFModule *>(program);
if (!mod) return 0;
return mod->table_key_printf(id, buf, buflen, key);
}
int bpf_table_leaf_snprintf(void *program, size_t id, char *buf, size_t buflen, const void *leaf) {
auto mod = static_cast<ebpf::BPFModule *>(program);
if (!mod) return 0;
return mod->table_key_printf(id, buf, buflen, leaf);
}
}
src/cc/bpf_common.h
View file @ 02bf6819
......@@ -48,6 +48,10 @@ size_t bpf_table_key_size(void *program, const char *table_name);
size_t bpf_table_key_size_id(void *program, size_t id);
size_t bpf_table_leaf_size(void *program, const char *table_name);
size_t bpf_table_leaf_size_id(void *program, size_t id);
int bpf_table_key_snprintf(void *program, size_t id, char *buf, size_t buflen, const void *key);
int bpf_table_leaf_snprintf(void *program, size_t id, char *buf, size_t buflen, const void *leaf);
//int bpf_table_key_sscanf(void *program, size_t id, const char *buf, void *key);
//int bpf_table_leaf_sscanf(void *program, size_t id, const char *buf, void *leaf);
int bpf_table_update(void *program, const char *table_name, const char *key, const char *leaf);
int bpf_table_update_id(void *program, size_t id, const char *key, const char *leaf);
......
src/cc/bpf_module.cc
View file @ 02bf6819
......@@ -109,31 +109,52 @@ BPFModule::BPFModule(unsigned flags)
BPFModule::~BPFModule() {
engine_.reset();
rw_engine_.reset();
ctx_.reset();
}
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);
}
// recursive helper to capture the arguments
void parse_type(IRBuilder<> &B, vector<Value *> *args, string *fmt, Type *type, Value *out) {
static void parse_type(IRBuilder<> &B, vector<Value *> *args, string *fmt,
Type *type, Value *out, 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++));
parse_type(B, args, fmt, field, B.CreateStructGEP(type, out, idx++), is_writer);
*fmt += " ";
}
*fmt += "}";
} else if (IntegerType *it = dyn_cast<IntegerType>(type)) {
if (is_writer)
*fmt += "0x";
if (it->getBitWidth() <= 8)
*fmt += "%hhi";
*fmt += "%hh";
else if (it->getBitWidth() <= 16)
*fmt += "%hi";
*fmt += "%h";
else if (it->getBitWidth() <= 32)
*fmt += "%i";
else if (it->getBitWidth() <= 64)
*fmt += "%li";
*fmt += "%l";
else
*fmt += "%lli";
args->push_back(out);
*fmt += "%ll";
if (is_writer)
*fmt += "x";
else
*fmt += "i";
args->push_back(is_writer ? B.CreateLoad(out) : out);
}
}
......@@ -168,14 +189,13 @@ Function * BPFModule::make_reader(Module *mod, Type *type) {
BasicBlock *label_exit = BasicBlock::Create(*ctx_, "exit", fn);
B.SetInsertPoint(label_entry);
vector<Value *> args;
vector<Value *> args({arg_in, nullptr});
string fmt;
parse_type(B, &args, &fmt, type, arg_out);
parse_type(B, &args, &fmt, type, arg_out, false);
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(), arg_in);
args[1] = B.CreateInBoundsGEP(fmt_gvar, vector<Value *>({B.getInt64(0), B.getInt64(0)}));
vector<Type *> sscanf_fn_args({B.getInt8PtrTy(), B.getInt8PtrTy()});
FunctionType *sscanf_fn_type = FunctionType::get(B.getInt32Ty(), sscanf_fn_args, /*isVarArg=*/true);
......@@ -203,7 +223,63 @@ Function * BPFModule::make_reader(Module *mod, Type *type) {
return fn;
}
unique_ptr<ExecutionEngine> BPFModule::finalize_reader(unique_ptr<Module> m) {
Function * 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_);
// The JIT currently supports a limited number of function prototypes, use the
// int (*) (int, char **, const char **) version
vector<Type *> fn_args({B.getInt32Ty(), B.getInt8PtrTy(), PointerType::getUnqual(type)});
FunctionType *fn_type = FunctionType::get(B.getInt32Ty(), fn_args, /*isVarArg=*/false);
Function *fn = Function::Create(fn_type, GlobalValue::ExternalLinkage,
"writer" + std::to_string(writers_.size()), mod);
auto arg_it = fn->arg_begin();
Argument *arg_len = arg_it++;
arg_len->setName("len");
Argument *arg_out = arg_it++;
arg_out->setName("out");
Argument *arg_in = arg_it++;
arg_in->setName("in");
BasicBlock *label_entry = BasicBlock::Create(*ctx_, "entry", fn);
B.SetInsertPoint(label_entry);
vector<Value *> args({arg_out, B.CreateZExt(arg_len, B.getInt64Ty()), nullptr});
string fmt;
parse_type(B, &args, &fmt, type, arg_in, 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] = fn;
return fn;
}
unique_ptr<ExecutionEngine> BPFModule::finalize_rw(unique_ptr<Module> m) {
Module *mod = &*m;
run_pass_manager(*mod);
......@@ -256,22 +332,24 @@ int BPFModule::annotate() {
Type *key_type = st->elements()[0];
Type *leaf_type = st->elements()[1];
table.key_reader = make_reader(&*m, key_type);
if (!table.key_reader) {
if (!table.key_reader)
errs() << "Failed to compile reader for " << *key_type << "\n";
continue;
}
table.leaf_reader = make_reader(&*m, leaf_type);
if (!table.leaf_reader) {
if (!table.leaf_reader)
errs() << "Failed to compile reader for " << *leaf_type << "\n";
continue;
}
table.key_writer = make_writer(&*m, key_type);
if (!table.key_writer)
errs() << "Failed to compile writer for " << *key_type << "\n";
table.leaf_writer = make_writer(&*m, leaf_type);
if (!table.leaf_writer)
errs() << "Failed to compile writer for " << *leaf_type << "\n";
}
}
}
reader_engine_ = finalize_reader(move(m));
if (reader_engine_)
reader_engine_->finalizeObject();
rw_engine_ = finalize_rw(move(m));
if (rw_engine_)
rw_engine_->finalizeObject();
return 0;
}
......@@ -467,7 +545,7 @@ int BPFModule::table_update(size_t id, const char *key_str, const char *leaf_str
const TableDesc &desc = (*tables_)[id];
if (desc.fd < 0) return -1;
if (!reader_engine_ || !desc.key_reader || !desc.leaf_reader) {
if (!rw_engine_ || !desc.key_reader || !desc.leaf_reader) {
fprintf(stderr, "Table sscanf not available\n");
return -1;
}
......@@ -475,19 +553,80 @@ int BPFModule::table_update(size_t id, const char *key_str, const char *leaf_str
unique_ptr<uint8_t[]> key(new uint8_t[desc.key_size]);
unique_ptr<uint8_t[]> leaf(new uint8_t[desc.leaf_size]);
GenericValue rc;
rc = reader_engine_->runFunction(desc.key_reader, vector<GenericValue>({GenericValue(),
GenericValue((void *)key_str),
GenericValue((void *)key.get())}));
rc = rw_engine_->runFunction(desc.key_reader, vector<GenericValue>({GenericValue(),
GenericValue((void *)key_str),
GenericValue((void *)key.get())}));
if (rc.IntVal != 0)
return -1;
rc = reader_engine_->runFunction(desc.leaf_reader, vector<GenericValue>({GenericValue(),
GenericValue((void *)leaf_str),
GenericValue((void *)leaf.get())}));
rc = rw_engine_->runFunction(desc.leaf_reader, vector<GenericValue>({GenericValue(),
GenericValue((void *)leaf_str),
GenericValue((void *)leaf.get())}));
if (rc.IntVal != 0)
return -1;
return bpf_update_elem(desc.fd, key.get(), leaf.get(), 0);
}
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()) {
fprintf(stderr, "table id %zu out of range\n", id);
return -1;
}
const TableDesc &desc = (*tables_)[id];
if (!desc.key_writer) {
fprintf(stderr, "table snprintf not implemented for %s key\n", desc.name.c_str());
return -1;
}
GenericValue gv_buflen;
gv_buflen.IntVal = APInt(32, buflen, true);
vector<GenericValue> args({gv_buflen, GenericValue((void *)buf), GenericValue((void *)key)});
GenericValue rc = rw_engine_->runFunction(desc.key_writer, args);
if (rc.IntVal.isNegative()) {
perror("snprintf");
return -1;
}
if (rc.IntVal.sge(buflen)) {
fprintf(stderr, "snprintf ran out of buffer space\n");
return -1;
}
return 0;
}
int BPFModule::table_leaf_printf(size_t id, char *buf, size_t buflen, const void *leaf) {
if (id >= tables_->size()) {
fprintf(stderr, "table id %zu out of range\n", id);
return -1;
}
const TableDesc &desc = (*tables_)[id];
if (!desc.leaf_writer) {
fprintf(stderr, "table snprintf not implemented for %s leaf\n", desc.name.c_str());
return -1;
}
GenericValue gv_buflen;
gv_buflen.IntVal = buflen;
vector<GenericValue> args({gv_buflen, GenericValue((void *)buf), GenericValue((void *)leaf)});
GenericValue rc = rw_engine_->runFunction(desc.leaf_writer, args);
if (rc.IntVal.isNegative()) {
perror("snprintf");
return -1;
}
if (rc.IntVal.sge(buflen)) {
fprintf(stderr, "snprintf ran out of buffer space\n");
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()) {
......
src/cc/bpf_module.h
View file @ 02bf6819
......@@ -42,8 +42,9 @@ class BPFModule {
int parse(llvm::Module *mod);
int finalize();
int annotate();
std::unique_ptr<llvm::ExecutionEngine> finalize_reader(std::unique_ptr<llvm::Module> mod);
std::unique_ptr<llvm::ExecutionEngine> finalize_rw(std::unique_ptr<llvm::Module> mod);
llvm::Function * make_reader(llvm::Module *mod, llvm::Type *type);
llvm::Function * make_writer(llvm::Module *mod, llvm::Type *type);
void dump_ir(llvm::Module &mod);
int load_file_module(std::unique_ptr<llvm::Module> *mod, const std::string &file, bool in_memory);
int load_includes(const std::string &tmpfile);
......@@ -70,10 +71,12 @@ class BPFModule {
const char * table_key_desc(const std::string &name) const;
size_t table_key_size(size_t id) const;
size_t table_key_size(const std::string &name) const;
int table_key_printf(size_t id, char *buf, size_t buflen, const void *key);
const char * table_leaf_desc(size_t id) const;
const char * table_leaf_desc(const std::string &name) const;
size_t table_leaf_size(size_t id) const;
size_t table_leaf_size(const std::string &name) const;
int table_leaf_printf(size_t id, char *buf, size_t buflen, const void *leaf);
int table_update(size_t id, const char *key, const char *leaf);
int table_update(const std::string &name, const char *key, const char *leaf);
char * license() const;
......@@ -84,7 +87,7 @@ class BPFModule {
std::string proto_filename_;
std::unique_ptr<llvm::LLVMContext> ctx_;
std::unique_ptr<llvm::ExecutionEngine> engine_;
std::unique_ptr<llvm::ExecutionEngine> reader_engine_;
std::unique_ptr<llvm::ExecutionEngine> rw_engine_;
std::unique_ptr<llvm::Module> mod_;
std::unique_ptr<BLoader> b_loader_;
std::unique_ptr<ClangLoader> clang_loader_;
......@@ -93,6 +96,7 @@ class BPFModule {
std::map<std::string, size_t> table_names_;
std::vector<std::string> function_names_;
std::map<llvm::Type *, llvm::Function *> readers_;
std::map<llvm::Type *, llvm::Function *> writers_;
};
} // namespace ebpf
src/cc/frontends/clang/b_frontend_action.cc
View file @ 02bf6819
......@@ -227,24 +227,24 @@ bool BTypeVisitor::VisitCallExpr(CallExpr *Call) {
if (Decl->getName() == "incr_cksum_l3") {
text = "bpf_l3_csum_replace_(" + fn_args_[0]->getName().str() + ", (u64)";
text += args[0] + ", " + args[1] + ", " + args[2] + ", sizeof(" + args[2] + "))";
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
} else if (Decl->getName() == "incr_cksum_l4") {
text = "bpf_l4_csum_replace_(" + fn_args_[0]->getName().str() + ", (u64)";
text += args[0] + ", " + args[1] + ", " + args[2];
text += ", ((" + args[3] + " & 0x1) << 4) | sizeof(" + args[2] + "))";
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
} else if (Decl->getName() == "bpf_trace_printk") {
// #define bpf_trace_printk(fmt, args...)
// ({ char _fmt[] = fmt; bpf_trace_printk_(_fmt, sizeof(_fmt), args...); })
text = "({ char _fmt[] = " + args[0] + "; bpf_trace_printk_(_fmt, sizeof(_fmt)";
if (args.size() > 1)
text += ", ";
for (auto arg = args.begin() + 1; arg != args.end(); ++arg) {
text += *arg;
if (arg + 1 != args.end())
text += ", ";
if (args.size() <= 1) {
text += "); })";
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
} else {
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getArg(0)->getLocEnd()), text);
rewriter_.InsertTextAfter(Call->getLocEnd(), "); }");
}
text += "); })";
}
rewriter_.ReplaceText(SourceRange(Call->getLocStart(), Call->getLocEnd()), text);
}
}
}
......
src/cc/table_desc.h
View file @ 02bf6819
......@@ -33,6 +33,8 @@ struct TableDesc {
std::string leaf_desc;
llvm::Function *key_reader;
llvm::Function *leaf_reader;
llvm::Function *key_writer;
llvm::Function *leaf_writer;
};
} // namespace ebpf
tests/cc/test_clang.py
View file @ 02bf6819
......@@ -82,6 +82,18 @@ int do_request(struct pt_regs *ctx, struct request *req) {
return 0;
}
"""
b = BPF(text=text, debug=0)
fn = b.load_func("do_request", BPF.KPROBE)
def test_blk_start_request(self):
text = """
#include <linux/blkdev.h>
#include <uapi/linux/ptrace.h>
int do_request(struct pt_regs *ctx, int req) {
bpf_trace_printk("req ptr: 0x%x\\n", req);
return 0;
}
"""
b = BPF(text=text, debug=0)
fn = b.load_func("do_request", BPF.KPROBE)
......
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