1 /* SPDX-License-Identifier: LGPL-2.1 */ 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 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU Lesser General Public 12 * License as published by the Free Software Foundation; 13 * version 2.1 of the License (not later!) 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU Lesser General Public License for more details. 19 * 20 * You should have received a copy of the GNU Lesser General Public 21 * License along with this program; if not, see <http://www.gnu.org/licenses> 22 */ 23 #ifndef __BPF_LIBBPF_H 24 #define __BPF_LIBBPF_H 25 26 #include <stdio.h> 27 #include <stdint.h> 28 #include <stdbool.h> 29 #include <sys/types.h> // for size_t 30 #include <linux/bpf.h> 31 32 enum libbpf_errno { 33 __LIBBPF_ERRNO__START = 4000, 34 35 /* Something wrong in libelf */ 36 LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, 37 LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ 38 LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ 39 LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ 40 LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ 41 LIBBPF_ERRNO__RELOC, /* Relocation failed */ 42 LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ 43 LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ 44 LIBBPF_ERRNO__PROG2BIG, /* Program too big */ 45 LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ 46 LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ 47 LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */ 48 LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ 49 __LIBBPF_ERRNO__END, 50 }; 51 52 int libbpf_strerror(int err, char *buf, size_t size); 53 54 /* 55 * __printf is defined in include/linux/compiler-gcc.h. However, 56 * it would be better if libbpf.h didn't depend on Linux header files. 57 * So instead of __printf, here we use gcc attribute directly. 58 */ 59 typedef int (*libbpf_print_fn_t)(const char *, ...) 60 __attribute__((format(printf, 1, 2))); 61 62 void libbpf_set_print(libbpf_print_fn_t warn, 63 libbpf_print_fn_t info, 64 libbpf_print_fn_t debug); 65 66 /* Hide internal to user */ 67 struct bpf_object; 68 69 struct bpf_object *bpf_object__open(const char *path); 70 struct bpf_object *bpf_object__open_buffer(void *obj_buf, 71 size_t obj_buf_sz, 72 const char *name); 73 int bpf_object__pin(struct bpf_object *object, const char *path); 74 void bpf_object__close(struct bpf_object *object); 75 76 /* Load/unload object into/from kernel */ 77 int bpf_object__load(struct bpf_object *obj); 78 int bpf_object__unload(struct bpf_object *obj); 79 const char *bpf_object__name(struct bpf_object *obj); 80 unsigned int bpf_object__kversion(struct bpf_object *obj); 81 int bpf_object__btf_fd(const struct bpf_object *obj); 82 83 struct bpf_object *bpf_object__next(struct bpf_object *prev); 84 #define bpf_object__for_each_safe(pos, tmp) \ 85 for ((pos) = bpf_object__next(NULL), \ 86 (tmp) = bpf_object__next(pos); \ 87 (pos) != NULL; \ 88 (pos) = (tmp), (tmp) = bpf_object__next(tmp)) 89 90 typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *); 91 int bpf_object__set_priv(struct bpf_object *obj, void *priv, 92 bpf_object_clear_priv_t clear_priv); 93 void *bpf_object__priv(struct bpf_object *prog); 94 95 /* Accessors of bpf_program */ 96 struct bpf_program; 97 struct bpf_program *bpf_program__next(struct bpf_program *prog, 98 struct bpf_object *obj); 99 100 #define bpf_object__for_each_program(pos, obj) \ 101 for ((pos) = bpf_program__next(NULL, (obj)); \ 102 (pos) != NULL; \ 103 (pos) = bpf_program__next((pos), (obj))) 104 105 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, 106 void *); 107 108 int bpf_program__set_priv(struct bpf_program *prog, void *priv, 109 bpf_program_clear_priv_t clear_priv); 110 111 void *bpf_program__priv(struct bpf_program *prog); 112 void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex); 113 114 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy); 115 116 int bpf_program__fd(struct bpf_program *prog); 117 int bpf_program__pin_instance(struct bpf_program *prog, const char *path, 118 int instance); 119 int bpf_program__pin(struct bpf_program *prog, const char *path); 120 121 struct bpf_insn; 122 123 /* 124 * Libbpf allows callers to adjust BPF programs before being loaded 125 * into kernel. One program in an object file can be transformed into 126 * multiple variants to be attached to different hooks. 127 * 128 * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd 129 * form an API for this purpose. 130 * 131 * - bpf_program_prep_t: 132 * Defines a 'preprocessor', which is a caller defined function 133 * passed to libbpf through bpf_program__set_prep(), and will be 134 * called before program is loaded. The processor should adjust 135 * the program one time for each instance according to the instance id 136 * passed to it. 137 * 138 * - bpf_program__set_prep: 139 * Attaches a preprocessor to a BPF program. The number of instances 140 * that should be created is also passed through this function. 141 * 142 * - bpf_program__nth_fd: 143 * After the program is loaded, get resulting FD of a given instance 144 * of the BPF program. 145 * 146 * If bpf_program__set_prep() is not used, the program would be loaded 147 * without adjustment during bpf_object__load(). The program has only 148 * one instance. In this case bpf_program__fd(prog) is equal to 149 * bpf_program__nth_fd(prog, 0). 150 */ 151 152 struct bpf_prog_prep_result { 153 /* 154 * If not NULL, load new instruction array. 155 * If set to NULL, don't load this instance. 156 */ 157 struct bpf_insn *new_insn_ptr; 158 int new_insn_cnt; 159 160 /* If not NULL, result FD is written to it. */ 161 int *pfd; 162 }; 163 164 /* 165 * Parameters of bpf_program_prep_t: 166 * - prog: The bpf_program being loaded. 167 * - n: Index of instance being generated. 168 * - insns: BPF instructions array. 169 * - insns_cnt:Number of instructions in insns. 170 * - res: Output parameter, result of transformation. 171 * 172 * Return value: 173 * - Zero: pre-processing success. 174 * - Non-zero: pre-processing error, stop loading. 175 */ 176 typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n, 177 struct bpf_insn *insns, int insns_cnt, 178 struct bpf_prog_prep_result *res); 179 180 int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, 181 bpf_program_prep_t prep); 182 183 int bpf_program__nth_fd(struct bpf_program *prog, int n); 184 185 /* 186 * Adjust type of BPF program. Default is kprobe. 187 */ 188 int bpf_program__set_socket_filter(struct bpf_program *prog); 189 int bpf_program__set_tracepoint(struct bpf_program *prog); 190 int bpf_program__set_raw_tracepoint(struct bpf_program *prog); 191 int bpf_program__set_kprobe(struct bpf_program *prog); 192 int bpf_program__set_sched_cls(struct bpf_program *prog); 193 int bpf_program__set_sched_act(struct bpf_program *prog); 194 int bpf_program__set_xdp(struct bpf_program *prog); 195 int bpf_program__set_perf_event(struct bpf_program *prog); 196 void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type); 197 void bpf_program__set_expected_attach_type(struct bpf_program *prog, 198 enum bpf_attach_type type); 199 200 bool bpf_program__is_socket_filter(struct bpf_program *prog); 201 bool bpf_program__is_tracepoint(struct bpf_program *prog); 202 bool bpf_program__is_raw_tracepoint(struct bpf_program *prog); 203 bool bpf_program__is_kprobe(struct bpf_program *prog); 204 bool bpf_program__is_sched_cls(struct bpf_program *prog); 205 bool bpf_program__is_sched_act(struct bpf_program *prog); 206 bool bpf_program__is_xdp(struct bpf_program *prog); 207 bool bpf_program__is_perf_event(struct bpf_program *prog); 208 209 /* 210 * No need for __attribute__((packed)), all members of 'bpf_map_def' 211 * are all aligned. In addition, using __attribute__((packed)) 212 * would trigger a -Wpacked warning message, and lead to an error 213 * if -Werror is set. 214 */ 215 struct bpf_map_def { 216 unsigned int type; 217 unsigned int key_size; 218 unsigned int value_size; 219 unsigned int max_entries; 220 unsigned int map_flags; 221 }; 222 223 /* 224 * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel, 225 * so no need to worry about a name clash. 226 */ 227 struct bpf_map; 228 struct bpf_map * 229 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); 230 231 /* 232 * Get bpf_map through the offset of corresponding struct bpf_map_def 233 * in the BPF object file. 234 */ 235 struct bpf_map * 236 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); 237 238 struct bpf_map * 239 bpf_map__next(struct bpf_map *map, struct bpf_object *obj); 240 #define bpf_map__for_each(pos, obj) \ 241 for ((pos) = bpf_map__next(NULL, (obj)); \ 242 (pos) != NULL; \ 243 (pos) = bpf_map__next((pos), (obj))) 244 245 int bpf_map__fd(struct bpf_map *map); 246 const struct bpf_map_def *bpf_map__def(struct bpf_map *map); 247 const char *bpf_map__name(struct bpf_map *map); 248 uint32_t bpf_map__btf_key_type_id(const struct bpf_map *map); 249 uint32_t bpf_map__btf_value_type_id(const struct bpf_map *map); 250 251 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); 252 int bpf_map__set_priv(struct bpf_map *map, void *priv, 253 bpf_map_clear_priv_t clear_priv); 254 void *bpf_map__priv(struct bpf_map *map); 255 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 256 int bpf_map__pin(struct bpf_map *map, const char *path); 257 258 long libbpf_get_error(const void *ptr); 259 260 struct bpf_prog_load_attr { 261 const char *file; 262 enum bpf_prog_type prog_type; 263 enum bpf_attach_type expected_attach_type; 264 int ifindex; 265 }; 266 267 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, 268 struct bpf_object **pobj, int *prog_fd); 269 int bpf_prog_load(const char *file, enum bpf_prog_type type, 270 struct bpf_object **pobj, int *prog_fd); 271 272 int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); 273 274 enum bpf_perf_event_ret { 275 LIBBPF_PERF_EVENT_DONE = 0, 276 LIBBPF_PERF_EVENT_ERROR = -1, 277 LIBBPF_PERF_EVENT_CONT = -2, 278 }; 279 280 typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(void *event, 281 void *priv); 282 int bpf_perf_event_read_simple(void *mem, unsigned long size, 283 unsigned long page_size, 284 void **buf, size_t *buf_len, 285 bpf_perf_event_print_t fn, void *priv); 286 #endif 287