1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */ 2 3 /* 4 * Common eBPF ELF object loading operations. 5 * 6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 8 * Copyright (C) 2015 Huawei Inc. 9 */ 10 #ifndef __LIBBPF_LIBBPF_H 11 #define __LIBBPF_LIBBPF_H 12 13 #include <stdio.h> 14 #include <stdint.h> 15 #include <stdbool.h> 16 #include <sys/types.h> // for size_t 17 #include <linux/bpf.h> 18 19 #ifndef LIBBPF_API 20 #define LIBBPF_API __attribute__((visibility("default"))) 21 #endif 22 23 enum libbpf_errno { 24 __LIBBPF_ERRNO__START = 4000, 25 26 /* Something wrong in libelf */ 27 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, 28 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ 29 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ 30 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ 31 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ 32 LIBBPF_ERRNO__RELOC, /* Relocation failed */ 33 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ 34 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ 35 LIBBPF_ERRNO__PROG2BIG, /* Program too big */ 36 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ 37 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ 38 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ 39 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ 40 LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */ 41 __LIBBPF_ERRNO__END, 42 }; 43 44 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size); 45 46 /* 47 * __printf is defined in include/linux/compiler-gcc.h. However, 48 * it would be better if libbpf.h didn't depend on Linux header files. 49 * So instead of __printf, here we use gcc attribute directly. 50 */ 51 typedef int (*libbpf_print_fn_t)(const char *, ...) 52 __attribute__((format(printf, 1, 2))); 53 54 LIBBPF_API void libbpf_set_print(libbpf_print_fn_t warn, 55 libbpf_print_fn_t info, 56 libbpf_print_fn_t debug); 57 58 /* Hide internal to user */ 59 struct bpf_object; 60 61 struct bpf_object_open_attr { 62 const char *file; 63 enum bpf_prog_type prog_type; 64 }; 65 66 LIBBPF_API struct bpf_object *bpf_object__open(const char *path); 67 LIBBPF_API struct bpf_object * 68 bpf_object__open_xattr(struct bpf_object_open_attr *attr); 69 struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr, 70 int flags); 71 LIBBPF_API struct bpf_object *bpf_object__open_buffer(void *obj_buf, 72 size_t obj_buf_sz, 73 const char *name); 74 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path); 75 LIBBPF_API void bpf_object__close(struct bpf_object *object); 76 77 /* Load/unload object into/from kernel */ 78 LIBBPF_API int bpf_object__load(struct bpf_object *obj); 79 LIBBPF_API int bpf_object__unload(struct bpf_object *obj); 80 LIBBPF_API const char *bpf_object__name(struct bpf_object *obj); 81 LIBBPF_API unsigned int bpf_object__kversion(struct bpf_object *obj); 82 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj); 83 84 LIBBPF_API struct bpf_program * 85 bpf_object__find_program_by_title(struct bpf_object *obj, const char *title); 86 87 LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev); 88 #define bpf_object__for_each_safe(pos, tmp) \ 89 for ((pos) = bpf_object__next(NULL), \ 90 (tmp) = bpf_object__next(pos); \ 91 (pos) != NULL; \ 92 (pos) = (tmp), (tmp) = bpf_object__next(tmp)) 93 94 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *); 95 LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv, 96 bpf_object_clear_priv_t clear_priv); 97 LIBBPF_API void *bpf_object__priv(struct bpf_object *prog); 98 99 LIBBPF_API int 100 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, 101 enum bpf_attach_type *expected_attach_type); 102 LIBBPF_API int libbpf_attach_type_by_name(const char *name, 103 enum bpf_attach_type *attach_type); 104 105 /* Accessors of bpf_program */ 106 struct bpf_program; 107 LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog, 108 struct bpf_object *obj); 109 110 #define bpf_object__for_each_program(pos, obj) \ 111 for ((pos) = bpf_program__next(NULL, (obj)); \ 112 (pos) != NULL; \ 113 (pos) = bpf_program__next((pos), (obj))) 114 115 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, 116 void *); 117 118 LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv, 119 bpf_program_clear_priv_t clear_priv); 120 121 LIBBPF_API void *bpf_program__priv(struct bpf_program *prog); 122 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog, 123 __u32 ifindex); 124 125 LIBBPF_API const char *bpf_program__title(struct bpf_program *prog, 126 bool needs_copy); 127 128 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license, 129 __u32 kern_version); 130 LIBBPF_API int bpf_program__fd(struct bpf_program *prog); 131 LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog, 132 const char *path, 133 int instance); 134 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path); 135 LIBBPF_API void bpf_program__unload(struct bpf_program *prog); 136 137 struct bpf_insn; 138 139 /* 140 * Libbpf allows callers to adjust BPF programs before being loaded 141 * into kernel. One program in an object file can be transformed into 142 * multiple variants to be attached to different hooks. 143 * 144 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd 145 * form an API for this purpose. 146 * 147 * - bpf_program_prep_t: 148 * Defines a 'preprocessor', which is a caller defined function 149 * passed to libbpf through bpf_program__set_prep(), and will be 150 * called before program is loaded. The processor should adjust 151 * the program one time for each instance according to the instance id 152 * passed to it. 153 * 154 * - bpf_program__set_prep: 155 * Attaches a preprocessor to a BPF program. The number of instances 156 * that should be created is also passed through this function. 157 * 158 * - bpf_program__nth_fd: 159 * After the program is loaded, get resulting FD of a given instance 160 * of the BPF program. 161 * 162 * If bpf_program__set_prep() is not used, the program would be loaded 163 * without adjustment during bpf_object__load(). The program has only 164 * one instance. In this case bpf_program__fd(prog) is equal to 165 * bpf_program__nth_fd(prog, 0). 166 */ 167 168 struct bpf_prog_prep_result { 169 /* 170 * If not NULL, load new instruction array. 171 * If set to NULL, don't load this instance. 172 */ 173 struct bpf_insn *new_insn_ptr; 174 int new_insn_cnt; 175 176 /* If not NULL, result FD is written to it. */ 177 int *pfd; 178 }; 179 180 /* 181 * Parameters of bpf_program_prep_t: 182 * - prog: The bpf_program being loaded. 183 * - n: Index of instance being generated. 184 * - insns: BPF instructions array. 185 * - insns_cnt:Number of instructions in insns. 186 * - res: Output parameter, result of transformation. 187 * 188 * Return value: 189 * - Zero: pre-processing success. 190 * - Non-zero: pre-processing error, stop loading. 191 */ 192 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n, 193 struct bpf_insn *insns, int insns_cnt, 194 struct bpf_prog_prep_result *res); 195 196 LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, 197 bpf_program_prep_t prep); 198 199 LIBBPF_API int bpf_program__nth_fd(struct bpf_program *prog, int n); 200 201 /* 202 * Adjust type of BPF program. Default is kprobe. 203 */ 204 LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog); 205 LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog); 206 LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog); 207 LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog); 208 LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog); 209 LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog); 210 LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog); 211 LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog); 212 LIBBPF_API void bpf_program__set_type(struct bpf_program *prog, 213 enum bpf_prog_type type); 214 LIBBPF_API void 215 bpf_program__set_expected_attach_type(struct bpf_program *prog, 216 enum bpf_attach_type type); 217 218 LIBBPF_API bool bpf_program__is_socket_filter(struct bpf_program *prog); 219 LIBBPF_API bool bpf_program__is_tracepoint(struct bpf_program *prog); 220 LIBBPF_API bool bpf_program__is_raw_tracepoint(struct bpf_program *prog); 221 LIBBPF_API bool bpf_program__is_kprobe(struct bpf_program *prog); 222 LIBBPF_API bool bpf_program__is_sched_cls(struct bpf_program *prog); 223 LIBBPF_API bool bpf_program__is_sched_act(struct bpf_program *prog); 224 LIBBPF_API bool bpf_program__is_xdp(struct bpf_program *prog); 225 LIBBPF_API bool bpf_program__is_perf_event(struct bpf_program *prog); 226 227 /* 228 * No need for __attribute__((packed)), all members of 'bpf_map_def' 229 * are all aligned. In addition, using __attribute__((packed)) 230 * would trigger a -Wpacked warning message, and lead to an error 231 * if -Werror is set. 232 */ 233 struct bpf_map_def { 234 unsigned int type; 235 unsigned int key_size; 236 unsigned int value_size; 237 unsigned int max_entries; 238 unsigned int map_flags; 239 }; 240 241 /* 242 * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel, 243 * so no need to worry about a name clash. 244 */ 245 struct bpf_map; 246 LIBBPF_API struct bpf_map * 247 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); 248 249 /* 250 * Get bpf_map through the offset of corresponding struct bpf_map_def 251 * in the BPF object file. 252 */ 253 LIBBPF_API struct bpf_map * 254 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); 255 256 LIBBPF_API struct bpf_map * 257 bpf_map__next(struct bpf_map *map, struct bpf_object *obj); 258 #define bpf_map__for_each(pos, obj) \ 259 for ((pos) = bpf_map__next(NULL, (obj)); \ 260 (pos) != NULL; \ 261 (pos) = bpf_map__next((pos), (obj))) 262 263 LIBBPF_API int bpf_map__fd(struct bpf_map *map); 264 LIBBPF_API const struct bpf_map_def *bpf_map__def(struct bpf_map *map); 265 LIBBPF_API const char *bpf_map__name(struct bpf_map *map); 266 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map); 267 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map); 268 269 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); 270 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv, 271 bpf_map_clear_priv_t clear_priv); 272 LIBBPF_API void *bpf_map__priv(struct bpf_map *map); 273 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd); 274 LIBBPF_API bool bpf_map__is_offload_neutral(struct bpf_map *map); 275 LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 276 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path); 277 278 LIBBPF_API long libbpf_get_error(const void *ptr); 279 280 struct bpf_prog_load_attr { 281 const char *file; 282 enum bpf_prog_type prog_type; 283 enum bpf_attach_type expected_attach_type; 284 int ifindex; 285 }; 286 287 LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 288 struct bpf_object **pobj, int *prog_fd); 289 LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type, 290 struct bpf_object **pobj, int *prog_fd); 291 292 LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); 293 294 enum bpf_perf_event_ret { 295 LIBBPF_PERF_EVENT_DONE = 0, 296 LIBBPF_PERF_EVENT_ERROR = -1, 297 LIBBPF_PERF_EVENT_CONT = -2, 298 }; 299 300 struct perf_event_header; 301 typedef enum bpf_perf_event_ret 302 (*bpf_perf_event_print_t)(struct perf_event_header *hdr, 303 void *private_data); 304 LIBBPF_API enum bpf_perf_event_ret 305 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, 306 void **copy_mem, size_t *copy_size, 307 bpf_perf_event_print_t fn, void *private_data); 308 309 struct nlattr; 310 typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb); 311 int libbpf_netlink_open(unsigned int *nl_pid); 312 int libbpf_nl_get_link(int sock, unsigned int nl_pid, 313 libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie); 314 int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex, 315 libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie); 316 int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex, 317 libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie); 318 int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle, 319 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie); 320 #endif /* __LIBBPF_LIBBPF_H */ 321