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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 bool bpf_module_rw_engine_enabled(void);
58 
59 class BPFModule {
60  private:
61   static const std::string FN_PREFIX;
62   int init_engine();
63   void initialize_rw_engine();
64   void cleanup_rw_engine();
65   int parse(llvm::Module *mod);
66   int finalize();
67   int annotate();
68   void annotate_light();
69   std::unique_ptr<llvm::ExecutionEngine> finalize_rw(std::unique_ptr<llvm::Module> mod);
70   std::string make_reader(llvm::Module *mod, llvm::Type *type);
71   std::string make_writer(llvm::Module *mod, llvm::Type *type);
72   void dump_ir(llvm::Module &mod);
73   int load_file_module(std::unique_ptr<llvm::Module> *mod, const std::string &file, bool in_memory);
74   int load_includes(const std::string &text);
75   int load_cfile(const std::string &file, bool in_memory, const char *cflags[], int ncflags);
76   int kbuild_flags(const char *uname_release, std::vector<std::string> *cflags);
77   int run_pass_manager(llvm::Module &mod);
78   StatusTuple sscanf(std::string fn_name, const char *str, void *val);
79   StatusTuple snprintf(std::string fn_name, char *str, size_t sz,
80                        const void *val);
81 
82  public:
83   BPFModule(unsigned flags, TableStorage *ts = nullptr, bool rw_engine_enabled = true,
84             const std::string &maps_ns = "");
85   ~BPFModule();
86   int load_b(const std::string &filename, const std::string &proto_filename);
87   int load_c(const std::string &filename, const char *cflags[], int ncflags);
88   int load_string(const std::string &text, const char *cflags[], int ncflags);
id()89   std::string id() const { return id_; }
maps_ns()90   std::string maps_ns() const { return maps_ns_; }
91   size_t num_functions() const;
92   uint8_t * function_start(size_t id) const;
93   uint8_t * function_start(const std::string &name) const;
94   const char * function_source(const std::string &name) const;
95   const char * function_source_rewritten(const std::string &name) const;
96   int annotate_prog_tag(const std::string &name, int fd,
97 			struct bpf_insn *insn, int prog_len);
98   const char * function_name(size_t id) const;
99   size_t function_size(size_t id) const;
100   size_t function_size(const std::string &name) const;
101   size_t num_tables() const;
102   size_t table_id(const std::string &name) const;
103   int table_fd(size_t id) const;
104   int table_fd(const std::string &name) const;
105   const char * table_name(size_t id) const;
106   int table_type(const std::string &name) const;
107   int table_type(size_t id) const;
108   size_t table_max_entries(const std::string &name) const;
109   size_t table_max_entries(size_t id) const;
110   int table_flags(const std::string &name) const;
111   int table_flags(size_t id) const;
112   const char * table_key_desc(size_t id) const;
113   const char * table_key_desc(const std::string &name) const;
114   size_t table_key_size(size_t id) const;
115   size_t table_key_size(const std::string &name) const;
116   int table_key_printf(size_t id, char *buf, size_t buflen, const void *key);
117   int table_key_scanf(size_t id, const char *buf, void *key);
118   const char * table_leaf_desc(size_t id) const;
119   const char * table_leaf_desc(const std::string &name) const;
120   size_t table_leaf_size(size_t id) const;
121   size_t table_leaf_size(const std::string &name) const;
122   int table_leaf_printf(size_t id, char *buf, size_t buflen, const void *leaf);
123   int table_leaf_scanf(size_t id, const char *buf, void *leaf);
124   char * license() const;
125   unsigned kern_version() const;
table_storage()126   TableStorage &table_storage() { return *ts_; }
127 
128  private:
129   unsigned flags_;  // 0x1 for printing
130   bool rw_engine_enabled_;
131   bool used_b_loader_;
132   std::string filename_;
133   std::string proto_filename_;
134   std::unique_ptr<llvm::LLVMContext> ctx_;
135   std::unique_ptr<llvm::ExecutionEngine> engine_;
136   std::unique_ptr<llvm::ExecutionEngine> rw_engine_;
137   std::unique_ptr<llvm::Module> mod_;
138   std::unique_ptr<FuncSource> func_src_;
139   std::map<std::string, std::tuple<uint8_t *, uintptr_t>> sections_;
140   std::vector<TableDesc *> tables_;
141   std::map<std::string, size_t> table_names_;
142   std::vector<std::string> function_names_;
143   std::map<llvm::Type *, std::string> readers_;
144   std::map<llvm::Type *, std::string> writers_;
145   std::string id_;
146   std::string maps_ns_;
147   std::string mod_src_;
148   std::map<std::string, std::string> src_dbg_fmap_;
149   TableStorage *ts_;
150   std::unique_ptr<TableStorage> local_ts_;
151 };
152 
153 }  // namespace ebpf
154