text: /*
   * eBPF library header borrowed from BCC project
   * Copyright (C) 2018 The Android Open Source Project
   * 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.
   */
  
  /* eBPF mini library */
  
  #ifndef LIBBPF_H
  #define LIBBPF_H
  
  #include <linux/bpf.h>
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  enum bpf_probe_attach_type {
  	BPF_PROBE_ENTRY,
  	BPF_PROBE_RETURN
  };
  
  int bpf_create_map(enum bpf_map_type map_type, const char *name,
                     int key_size, int value_size, int max_entries,
                     int map_flags);
  int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags);
  int bpf_lookup_elem(int fd, void *key, void *value);
  int bpf_delete_elem(int fd, void *key);
  int bpf_get_first_key(int fd, void *key, size_t key_size);
  int bpf_get_next_key(int fd, void *key, void *next_key);
  
  /*
   * Load a BPF program, and return the FD of the loaded program.
   *
   * On newer Kernels, the parameter name is used to identify the loaded program
   * for inspection and debugging. It could be different from the function name.
   *
   * If log_level has value greater than 0, or the load failed, it will enable
   * extra logging of loaded BPF bytecode and register status, and will print the
   * logging message to stderr. In such cases:
   *   - If log_buf and log_buf_size are provided, it will use and also write the
   *     log messages to the provided log_buf. If log_buf is insufficient in size,
   *     it will not to any additional memory allocation.
   *   - Otherwise, it will allocate an internal temporary buffer for log message
   *     printing, and continue to attempt increase that allocated buffer size if
   *     initial attemp was insufficient in size.
   */
  int bpf_prog_load(enum bpf_prog_type prog_type, const char *name,
                    const struct bpf_insn *insns, int insn_len,
                    const char *license, unsigned kern_version,
                    int log_level, char *log_buf, unsigned log_buf_size);
  
  int bpf_attach_socket(int sockfd, int progfd);
  
  /* create RAW socket. If name is not NULL/a non-empty null-terminated string,
   * bind the raw socket to the interface 'name' */
  int bpf_open_raw_sock(const char *name);
  
  typedef void (*perf_reader_raw_cb)(void *cb_cookie, void *raw, int raw_size);
  typedef void (*perf_reader_lost_cb)(void *cb_cookie, uint64_t lost);
  
  int bpf_attach_kprobe(int progfd, enum bpf_probe_attach_type attach_type,
                        const char *ev_name, const char *fn_name, uint64_t fn_offset);
  int bpf_detach_kprobe(const char *ev_name);
  
  int bpf_attach_uprobe(int progfd, enum bpf_probe_attach_type attach_type,
                        const char *ev_name, const char *binary_path,
                        uint64_t offset, pid_t pid);
  int bpf_detach_uprobe(const char *ev_name);
  
  int bpf_attach_tracepoint(int progfd, const char *tp_category,
                            const char *tp_name);
  int bpf_detach_tracepoint(const char *tp_category, const char *tp_name);
  
  int bpf_attach_raw_tracepoint(int progfd, char *tp_name);
  
  void * bpf_open_perf_buffer(perf_reader_raw_cb raw_cb,
                              perf_reader_lost_cb lost_cb, void *cb_cookie,
                              int pid, int cpu, int page_cnt);
  
  /* attached a prog expressed by progfd to the device specified in dev_name */
  int bpf_attach_xdp(const char *dev_name, int progfd, uint32_t flags);
  
  // attach a prog expressed by progfd to run on a specific perf event. The perf
  // event will be created using the perf_event_attr pointer provided.
  int bpf_attach_perf_event_raw(int progfd, void *perf_event_attr, pid_t pid,
                                int cpu, int group_fd, unsigned long extra_flags);
  // attach a prog expressed by progfd to run on a specific perf event, with
  // certain sample period or sample frequency
  int bpf_attach_perf_event(int progfd, uint32_t ev_type, uint32_t ev_config,
                            uint64_t sample_period, uint64_t sample_freq,
                            pid_t pid, int cpu, int group_fd);
  
  int bpf_open_perf_event(uint32_t type, uint64_t config, int pid, int cpu);
  
  int bpf_close_perf_event_fd(int fd);
  
  int bpf_obj_pin(int fd, const char *pathname);
  int bpf_obj_get(const char *pathname);
  int bpf_obj_get_info(int prog_map_fd, void *info, uint32_t *info_len);
  int bpf_prog_compute_tag(const struct bpf_insn *insns, int prog_len,
                           unsigned long long *tag);
  int bpf_prog_get_tag(int fd, unsigned long long *tag);
  int bpf_prog_get_next_id(uint32_t start_id, uint32_t *next_id);
  int bpf_prog_get_fd_by_id(uint32_t id);
  int bpf_map_get_fd_by_id(uint32_t id);
  
  #define LOG_BUF_SIZE 65536
  
  // Put non-static/inline functions in their own section with this prefix +
  // fn_name to enable discovery by the bcc library.
  #define BPF_FN_PREFIX ".bpf.fn."
  
  /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
  
  #define BPF_ALU64_REG(OP, DST, SRC)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = 0,					\
  		.imm   = 0 })
  
  #define BPF_ALU32_REG(OP, DST, SRC)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = 0,					\
  		.imm   = 0 })
  
  /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
  
  #define BPF_ALU64_IMM(OP, DST, IMM)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
  		.dst_reg = DST,					\
  		.src_reg = 0,					\
  		.off   = 0,					\
  		.imm   = IMM })
  
  #define BPF_ALU32_IMM(OP, DST, IMM)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
  		.dst_reg = DST,					\
  		.src_reg = 0,					\
  		.off   = 0,					\
  		.imm   = IMM })
  
  /* Short form of mov, dst_reg = src_reg */
  
  #define BPF_MOV64_REG(DST, SRC)					\
  	((struct bpf_insn) {					\
  		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = 0,					\
  		.imm   = 0 })
  
  /* Short form of mov, dst_reg = imm32 */
  
  #define BPF_MOV64_IMM(DST, IMM)					\
  	((struct bpf_insn) {					\
  		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
  		.dst_reg = DST,					\
  		.src_reg = 0,					\
  		.off   = 0,					\
  		.imm   = IMM })
  
  /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
  #define BPF_LD_IMM64(DST, IMM)					\
  	BPF_LD_IMM64_RAW(DST, 0, IMM)
  
  #define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = 0,					\
  		.imm   = (__u32) (IMM) }),			\
  	((struct bpf_insn) {					\
  		.code  = 0, /* zero is reserved opcode */	\
  		.dst_reg = 0,					\
  		.src_reg = 0,					\
  		.off   = 0,					\
  		.imm   = ((__u64) (IMM)) >> 32 })
  
  #define BPF_PSEUDO_MAP_FD	1
  
  /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
  #define BPF_LD_MAP_FD(DST, MAP_FD)				\
  	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
  
  
  /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
  
  #define BPF_LD_ABS(SIZE, IMM)					\
  	((struct bpf_insn) {					\
  		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
  		.dst_reg = 0,					\
  		.src_reg = 0,					\
  		.off   = 0,					\
  		.imm   = IMM })
  
  /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
  
  #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
  	((struct bpf_insn) {					\
  		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = OFF,					\
  		.imm   = 0 })
  
  /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
  
  #define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
  	((struct bpf_insn) {					\
  		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = OFF,					\
  		.imm   = 0 })
  
  /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
  
  #define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
  		.dst_reg = DST,					\
  		.src_reg = 0,					\
  		.off   = OFF,					\
  		.imm   = IMM })
  
  /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
  
  #define BPF_JMP_REG(OP, DST, SRC, OFF)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = OFF,					\
  		.imm   = 0 })
  
  /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
  
  #define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
  	((struct bpf_insn) {					\
  		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
  		.dst_reg = DST,					\
  		.src_reg = 0,					\
  		.off   = OFF,					\
  		.imm   = IMM })
  
  /* Raw code statement block */
  
  #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
  	((struct bpf_insn) {					\
  		.code  = CODE,					\
  		.dst_reg = DST,					\
  		.src_reg = SRC,					\
  		.off   = OFF,					\
  		.imm   = IMM })
  
  /* Program exit */
  
  #define BPF_EXIT_INSN()						\
  	((struct bpf_insn) {					\
  		.code  = BPF_JMP | BPF_EXIT,			\
  		.dst_reg = 0,					\
  		.src_reg = 0,					\
  		.off   = 0,					\
  		.imm   = 0 })
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  