1 /*
2  * Copyright (c) 2015 PLUMgrid, Inc.
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 #pragma once
18 
19 #include <stdint.h>
20 #include <map>
21 #include <memory>
22 #include <string>
23 #include <vector>
24 
25 #include "bcc_exception.h"
26 
27 namespace llvm {
28 class ExecutionEngine;
29 class Function;
30 class LLVMContext;
31 class Module;
32 class Type;
33 }
34 
35 namespace ebpf {
36 
37 // Options to enable different debug logging.
38 enum {
39   // Debug output compiled LLVM IR.
40   DEBUG_LLVM_IR = 0x1,
41   // Debug output loaded BPF bytecode and register state on branches.
42   DEBUG_BPF = 0x2,
43   // Debug output pre-processor result.
44   DEBUG_PREPROCESSOR = 0x4,
45   // Debug output ASM instructions embedded with source.
46   DEBUG_SOURCE = 0x8,
47   // Debug output register state on all instructions in addition to DEBUG_BPF.
48   DEBUG_BPF_REGISTER_STATE = 0x10,
49 };
50 
51 class TableDesc;
52 class TableStorage;
53 class BLoader;
54 class ClangLoader;
55 class FuncSource;
56 
57 class BPFModule {
58  private:
59   static const std::string FN_PREFIX;
60   int init_engine();
61   int parse(llvm::Module *mod);
62   int finalize();
63   int annotate();
64   void annotate_light();
65   std::unique_ptr<llvm::ExecutionEngine> finalize_rw(std::unique_ptr<llvm::Module> mod);
66   std::string make_reader(llvm::Module *mod, llvm::Type *type);
67   std::string make_writer(llvm::Module *mod, llvm::Type *type);
68   void dump_ir(llvm::Module &mod);
69   int load_file_module(std::unique_ptr<llvm::Module> *mod, const std::string &file, bool in_memory);
70   int load_includes(const std::string &text);
71   int load_cfile(const std::string &file, bool in_memory, const char *cflags[], int ncflags);
72   int kbuild_flags(const char *uname_release, std::vector<std::string> *cflags);
73   int run_pass_manager(llvm::Module &mod);
74   StatusTuple sscanf(std::string fn_name, const char *str, void *val);
75   StatusTuple snprintf(std::string fn_name, char *str, size_t sz,
76                        const void *val);
77 
78  public:
79   BPFModule(unsigned flags, TableStorage *ts = nullptr, bool rw_engine_enabled = true,
80             const std::string &maps_ns = "");
81   ~BPFModule();
82   int load_b(const std::string &filename, const std::string &proto_filename);
83   int load_c(const std::string &filename, const char *cflags[], int ncflags);
84   int load_string(const std::string &text, const char *cflags[], int ncflags);
id()85   std::string id() const { return id_; }
maps_ns()86   std::string maps_ns() const { return maps_ns_; }
87   size_t num_functions() const;
88   uint8_t * function_start(size_t id) const;
89   uint8_t * function_start(const std::string &name) const;
90   const char * function_source(const std::string &name) const;
91   const char * function_source_rewritten(const std::string &name) const;
92   int annotate_prog_tag(const std::string &name, int fd,
93 			struct bpf_insn *insn, int prog_len);
94   const char * function_name(size_t id) const;
95   size_t function_size(size_t id) const;
96   size_t function_size(const std::string &name) const;
97   size_t num_tables() const;
98   size_t table_id(const std::string &name) const;
99   int table_fd(size_t id) const;
100   int table_fd(const std::string &name) const;
101   const char * table_name(size_t id) const;
102   int table_type(const std::string &name) const;
103   int table_type(size_t id) const;
104   size_t table_max_entries(const std::string &name) const;
105   size_t table_max_entries(size_t id) const;
106   int table_flags(const std::string &name) const;
107   int table_flags(size_t id) const;
108   const char * table_key_desc(size_t id) const;
109   const char * table_key_desc(const std::string &name) const;
110   size_t table_key_size(size_t id) const;
111   size_t table_key_size(const std::string &name) const;
112   int table_key_printf(size_t id, char *buf, size_t buflen, const void *key);
113   int table_key_scanf(size_t id, const char *buf, void *key);
114   const char * table_leaf_desc(size_t id) const;
115   const char * table_leaf_desc(const std::string &name) const;
116   size_t table_leaf_size(size_t id) const;
117   size_t table_leaf_size(const std::string &name) const;
118   int table_leaf_printf(size_t id, char *buf, size_t buflen, const void *leaf);
119   int table_leaf_scanf(size_t id, const char *buf, void *leaf);
120   char * license() const;
121   unsigned kern_version() const;
table_storage()122   TableStorage &table_storage() { return *ts_; }
123 
124  private:
125   unsigned flags_;  // 0x1 for printing
126   bool rw_engine_enabled_;
127   bool used_b_loader_;
128   std::string filename_;
129   std::string proto_filename_;
130   std::unique_ptr<llvm::LLVMContext> ctx_;
131   std::unique_ptr<llvm::ExecutionEngine> engine_;
132   std::unique_ptr<llvm::ExecutionEngine> rw_engine_;
133   std::unique_ptr<llvm::Module> mod_;
134   std::unique_ptr<FuncSource> func_src_;
135   std::map<std::string, std::tuple<uint8_t *, uintptr_t>> sections_;
136   std::vector<TableDesc *> tables_;
137   std::map<std::string, size_t> table_names_;
138   std::vector<std::string> function_names_;
139   std::map<llvm::Type *, std::string> readers_;
140   std::map<llvm::Type *, std::string> writers_;
141   std::string id_;
142   std::string maps_ns_;
143   std::string mod_src_;
144   std::map<std::string, std::string> src_dbg_fmap_;
145   TableStorage *ts_;
146   std::unique_ptr<TableStorage> local_ts_;
147 };
148 
149 }  // namespace ebpf
150