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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 /* eBPF mini library */
     17 
     18 #ifndef LIBBPF_H
     19 #define LIBBPF_H
     20 
     21 #include "compat/linux/bpf.h"
     22 #include <stdint.h>
     23 #include <sys/types.h>
     24 
     25 #ifdef __cplusplus
     26 extern "C" {
     27 #endif
     28 
     29 enum bpf_probe_attach_type {
     30 	BPF_PROBE_ENTRY,
     31 	BPF_PROBE_RETURN
     32 };
     33 
     34 int bpf_create_map(enum bpf_map_type map_type, const char *name,
     35                    int key_size, int value_size, int max_entries,
     36                    int map_flags);
     37 int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags);
     38 int bpf_lookup_elem(int fd, void *key, void *value);
     39 int bpf_delete_elem(int fd, void *key);
     40 int bpf_get_first_key(int fd, void *key, size_t key_size);
     41 int bpf_get_next_key(int fd, void *key, void *next_key);
     42 
     43 /*
     44  * Load a BPF program, and return the FD of the loaded program.
     45  *
     46  * On newer Kernels, the parameter name is used to identify the loaded program
     47  * for inspection and debugging. It could be different from the function name.
     48  *
     49  * If log_level has value greater than 0, or the load failed, it will enable
     50  * extra logging of loaded BPF bytecode and register status, and will print the
     51  * logging message to stderr. In such cases:
     52  *   - If log_buf and log_buf_size are provided, it will use and also write the
     53  *     log messages to the provided log_buf. If log_buf is insufficient in size,
     54  *     it will not to any additional memory allocation.
     55  *   - Otherwise, it will allocate an internal temporary buffer for log message
     56  *     printing, and continue to attempt increase that allocated buffer size if
     57  *     initial attemp was insufficient in size.
     58  */
     59 int bpf_prog_load(enum bpf_prog_type prog_type, const char *name,
     60                   const struct bpf_insn *insns, int insn_len,
     61                   const char *license, unsigned kern_version,
     62                   int log_level, char *log_buf, unsigned log_buf_size);
     63 
     64 int bpf_attach_socket(int sockfd, int progfd);
     65 
     66 /* create RAW socket. If name is not NULL/a non-empty null-terminated string,
     67  * bind the raw socket to the interface 'name' */
     68 int bpf_open_raw_sock(const char *name);
     69 
     70 typedef void (*perf_reader_raw_cb)(void *cb_cookie, void *raw, int raw_size);
     71 typedef void (*perf_reader_lost_cb)(void *cb_cookie, uint64_t lost);
     72 
     73 int bpf_attach_kprobe(int progfd, enum bpf_probe_attach_type attach_type,
     74                       const char *ev_name, const char *fn_name, uint64_t fn_offset);
     75 int bpf_detach_kprobe(const char *ev_name);
     76 
     77 int bpf_attach_uprobe(int progfd, enum bpf_probe_attach_type attach_type,
     78                       const char *ev_name, const char *binary_path,
     79                       uint64_t offset, pid_t pid);
     80 int bpf_detach_uprobe(const char *ev_name);
     81 
     82 int bpf_attach_tracepoint(int progfd, const char *tp_category,
     83                           const char *tp_name);
     84 int bpf_detach_tracepoint(const char *tp_category, const char *tp_name);
     85 
     86 int bpf_attach_raw_tracepoint(int progfd, char *tp_name);
     87 
     88 void * bpf_open_perf_buffer(perf_reader_raw_cb raw_cb,
     89                             perf_reader_lost_cb lost_cb, void *cb_cookie,
     90                             int pid, int cpu, int page_cnt);
     91 
     92 /* attached a prog expressed by progfd to the device specified in dev_name */
     93 int bpf_attach_xdp(const char *dev_name, int progfd, uint32_t flags);
     94 
     95 // attach a prog expressed by progfd to run on a specific perf event. The perf
     96 // event will be created using the perf_event_attr pointer provided.
     97 int bpf_attach_perf_event_raw(int progfd, void *perf_event_attr, pid_t pid,
     98                               int cpu, int group_fd, unsigned long extra_flags);
     99 // attach a prog expressed by progfd to run on a specific perf event, with
    100 // certain sample period or sample frequency
    101 int bpf_attach_perf_event(int progfd, uint32_t ev_type, uint32_t ev_config,
    102                           uint64_t sample_period, uint64_t sample_freq,
    103                           pid_t pid, int cpu, int group_fd);
    104 
    105 int bpf_open_perf_event(uint32_t type, uint64_t config, int pid, int cpu);
    106 
    107 int bpf_close_perf_event_fd(int fd);
    108 
    109 int bpf_obj_pin(int fd, const char *pathname);
    110 int bpf_obj_get(const char *pathname);
    111 int bpf_obj_get_info(int prog_map_fd, void *info, uint32_t *info_len);
    112 int bpf_prog_compute_tag(const struct bpf_insn *insns, int prog_len,
    113                          unsigned long long *tag);
    114 int bpf_prog_get_tag(int fd, unsigned long long *tag);
    115 int bpf_prog_get_next_id(uint32_t start_id, uint32_t *next_id);
    116 int bpf_prog_get_fd_by_id(uint32_t id);
    117 int bpf_map_get_fd_by_id(uint32_t id);
    118 
    119 #define LOG_BUF_SIZE 65536
    120 
    121 // Put non-static/inline functions in their own section with this prefix +
    122 // fn_name to enable discovery by the bcc library.
    123 #define BPF_FN_PREFIX ".bpf.fn."
    124 
    125 /* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
    126 
    127 #define BPF_ALU64_REG(OP, DST, SRC)				\
    128 	((struct bpf_insn) {					\
    129 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
    130 		.dst_reg = DST,					\
    131 		.src_reg = SRC,					\
    132 		.off   = 0,					\
    133 		.imm   = 0 })
    134 
    135 #define BPF_ALU32_REG(OP, DST, SRC)				\
    136 	((struct bpf_insn) {					\
    137 		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
    138 		.dst_reg = DST,					\
    139 		.src_reg = SRC,					\
    140 		.off   = 0,					\
    141 		.imm   = 0 })
    142 
    143 /* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
    144 
    145 #define BPF_ALU64_IMM(OP, DST, IMM)				\
    146 	((struct bpf_insn) {					\
    147 		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
    148 		.dst_reg = DST,					\
    149 		.src_reg = 0,					\
    150 		.off   = 0,					\
    151 		.imm   = IMM })
    152 
    153 #define BPF_ALU32_IMM(OP, DST, IMM)				\
    154 	((struct bpf_insn) {					\
    155 		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
    156 		.dst_reg = DST,					\
    157 		.src_reg = 0,					\
    158 		.off   = 0,					\
    159 		.imm   = IMM })
    160 
    161 /* Short form of mov, dst_reg = src_reg */
    162 
    163 #define BPF_MOV64_REG(DST, SRC)					\
    164 	((struct bpf_insn) {					\
    165 		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
    166 		.dst_reg = DST,					\
    167 		.src_reg = SRC,					\
    168 		.off   = 0,					\
    169 		.imm   = 0 })
    170 
    171 /* Short form of mov, dst_reg = imm32 */
    172 
    173 #define BPF_MOV64_IMM(DST, IMM)					\
    174 	((struct bpf_insn) {					\
    175 		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
    176 		.dst_reg = DST,					\
    177 		.src_reg = 0,					\
    178 		.off   = 0,					\
    179 		.imm   = IMM })
    180 
    181 /* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
    182 #define BPF_LD_IMM64(DST, IMM)					\
    183 	BPF_LD_IMM64_RAW(DST, 0, IMM)
    184 
    185 #define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
    186 	((struct bpf_insn) {					\
    187 		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
    188 		.dst_reg = DST,					\
    189 		.src_reg = SRC,					\
    190 		.off   = 0,					\
    191 		.imm   = (__u32) (IMM) }),			\
    192 	((struct bpf_insn) {					\
    193 		.code  = 0, /* zero is reserved opcode */	\
    194 		.dst_reg = 0,					\
    195 		.src_reg = 0,					\
    196 		.off   = 0,					\
    197 		.imm   = ((__u64) (IMM)) >> 32 })
    198 
    199 #define BPF_PSEUDO_MAP_FD	1
    200 
    201 /* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
    202 #define BPF_LD_MAP_FD(DST, MAP_FD)				\
    203 	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
    204 
    205 
    206 /* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
    207 
    208 #define BPF_LD_ABS(SIZE, IMM)					\
    209 	((struct bpf_insn) {					\
    210 		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
    211 		.dst_reg = 0,					\
    212 		.src_reg = 0,					\
    213 		.off   = 0,					\
    214 		.imm   = IMM })
    215 
    216 /* Memory load, dst_reg = *(uint *) (src_reg + off16) */
    217 
    218 #define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
    219 	((struct bpf_insn) {					\
    220 		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
    221 		.dst_reg = DST,					\
    222 		.src_reg = SRC,					\
    223 		.off   = OFF,					\
    224 		.imm   = 0 })
    225 
    226 /* Memory store, *(uint *) (dst_reg + off16) = src_reg */
    227 
    228 #define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
    229 	((struct bpf_insn) {					\
    230 		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
    231 		.dst_reg = DST,					\
    232 		.src_reg = SRC,					\
    233 		.off   = OFF,					\
    234 		.imm   = 0 })
    235 
    236 /* Memory store, *(uint *) (dst_reg + off16) = imm32 */
    237 
    238 #define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
    239 	((struct bpf_insn) {					\
    240 		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
    241 		.dst_reg = DST,					\
    242 		.src_reg = 0,					\
    243 		.off   = OFF,					\
    244 		.imm   = IMM })
    245 
    246 /* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
    247 
    248 #define BPF_JMP_REG(OP, DST, SRC, OFF)				\
    249 	((struct bpf_insn) {					\
    250 		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
    251 		.dst_reg = DST,					\
    252 		.src_reg = SRC,					\
    253 		.off   = OFF,					\
    254 		.imm   = 0 })
    255 
    256 /* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
    257 
    258 #define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
    259 	((struct bpf_insn) {					\
    260 		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
    261 		.dst_reg = DST,					\
    262 		.src_reg = 0,					\
    263 		.off   = OFF,					\
    264 		.imm   = IMM })
    265 
    266 /* Raw code statement block */
    267 
    268 #define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
    269 	((struct bpf_insn) {					\
    270 		.code  = CODE,					\
    271 		.dst_reg = DST,					\
    272 		.src_reg = SRC,					\
    273 		.off   = OFF,					\
    274 		.imm   = IMM })
    275 
    276 /* Program exit */
    277 
    278 #define BPF_EXIT_INSN()						\
    279 	((struct bpf_insn) {					\
    280 		.code  = BPF_JMP | BPF_EXIT,			\
    281 		.dst_reg = 0,					\
    282 		.src_reg = 0,					\
    283 		.off   = 0,					\
    284 		.imm   = 0 })
    285 
    286 #ifdef __cplusplus
    287 }
    288 #endif
    289 
    290 #endif
    291