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