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