/* * Common eBPF ELF object loading operations. * * Copyright (C) 2013-2015 Alexei Starovoitov * Copyright (C) 2015 Wang Nan * Copyright (C) 2015 Huawei Inc. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License (not later!) * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, see */ #ifndef __BPF_LIBBPF_H #define __BPF_LIBBPF_H #include #include #include #include // for size_t #include enum libbpf_errno { __LIBBPF_ERRNO__START = 4000, /* Something wrong in libelf */ LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START, LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */ LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */ LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */ LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */ LIBBPF_ERRNO__RELOC, /* Relocation failed */ LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */ LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */ LIBBPF_ERRNO__PROG2BIG, /* Program too big */ LIBBPF_ERRNO__KVER, /* Incorrect kernel version */ LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */ __LIBBPF_ERRNO__END, }; int libbpf_strerror(int err, char *buf, size_t size); /* * In include/linux/compiler-gcc.h, __printf is defined. However * it should be better if libbpf.h doesn't depend on Linux header file. * So instead of __printf, here we use gcc attribute directly. */ typedef int (*libbpf_print_fn_t)(const char *, ...) __attribute__((format(printf, 1, 2))); void libbpf_set_print(libbpf_print_fn_t warn, libbpf_print_fn_t info, libbpf_print_fn_t debug); /* Hide internal to user */ struct bpf_object; struct bpf_object *bpf_object__open(const char *path); struct bpf_object *bpf_object__open_buffer(void *obj_buf, size_t obj_buf_sz, const char *name); int bpf_object__pin(struct bpf_object *object, const char *path); void bpf_object__close(struct bpf_object *object); /* Load/unload object into/from kernel */ int bpf_object__load(struct bpf_object *obj); int bpf_object__unload(struct bpf_object *obj); const char *bpf_object__name(struct bpf_object *obj); unsigned int bpf_object__kversion(struct bpf_object *obj); struct bpf_object *bpf_object__next(struct bpf_object *prev); #define bpf_object__for_each_safe(pos, tmp) \ for ((pos) = bpf_object__next(NULL), \ (tmp) = bpf_object__next(pos); \ (pos) != NULL; \ (pos) = (tmp), (tmp) = bpf_object__next(tmp)) typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *); int bpf_object__set_priv(struct bpf_object *obj, void *priv, bpf_object_clear_priv_t clear_priv); void *bpf_object__priv(struct bpf_object *prog); /* Accessors of bpf_program. */ struct bpf_program; struct bpf_program *bpf_program__next(struct bpf_program *prog, struct bpf_object *obj); #define bpf_object__for_each_program(pos, obj) \ for ((pos) = bpf_program__next(NULL, (obj)); \ (pos) != NULL; \ (pos) = bpf_program__next((pos), (obj))) typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *); int bpf_program__set_priv(struct bpf_program *prog, void *priv, bpf_program_clear_priv_t clear_priv); void *bpf_program__priv(struct bpf_program *prog); const char *bpf_program__title(struct bpf_program *prog, bool needs_copy); int bpf_program__fd(struct bpf_program *prog); int bpf_program__pin_instance(struct bpf_program *prog, const char *path, int instance); int bpf_program__pin(struct bpf_program *prog, const char *path); struct bpf_insn; /* * Libbpf allows callers to adjust BPF programs before being loaded * into kernel. One program in an object file can be transform into * multiple variants to be attached to different code. * * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd * are APIs for this propose. * * - bpf_program_prep_t: * It defines 'preprocessor', which is a caller defined function * passed to libbpf through bpf_program__set_prep(), and will be * called before program is loaded. The processor should adjust * the program one time for each instances according to the number * passed to it. * * - bpf_program__set_prep: * Attachs a preprocessor to a BPF program. The number of instances * whould be created is also passed through this function. * * - bpf_program__nth_fd: * After the program is loaded, get resuling fds from bpf program for * each instances. * * If bpf_program__set_prep() is not used, the program whould be loaded * without adjustment during bpf_object__load(). The program has only * one instance. In this case bpf_program__fd(prog) is equal to * bpf_program__nth_fd(prog, 0). */ struct bpf_prog_prep_result { /* * If not NULL, load new instruction array. * If set to NULL, don't load this instance. */ struct bpf_insn *new_insn_ptr; int new_insn_cnt; /* If not NULL, result fd is set to it */ int *pfd; }; /* * Parameters of bpf_program_prep_t: * - prog: The bpf_program being loaded. * - n: Index of instance being generated. * - insns: BPF instructions array. * - insns_cnt:Number of instructions in insns. * - res: Output parameter, result of transformation. * * Return value: * - Zero: pre-processing success. * - Non-zero: pre-processing, stop loading. */ typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n, struct bpf_insn *insns, int insns_cnt, struct bpf_prog_prep_result *res); int bpf_program__set_prep(struct bpf_program *prog, int nr_instance, bpf_program_prep_t prep); int bpf_program__nth_fd(struct bpf_program *prog, int n); /* * Adjust type of bpf program. Default is kprobe. */ int bpf_program__set_socket_filter(struct bpf_program *prog); int bpf_program__set_tracepoint(struct bpf_program *prog); int bpf_program__set_kprobe(struct bpf_program *prog); int bpf_program__set_sched_cls(struct bpf_program *prog); int bpf_program__set_sched_act(struct bpf_program *prog); int bpf_program__set_xdp(struct bpf_program *prog); int bpf_program__set_perf_event(struct bpf_program *prog); void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type); bool bpf_program__is_socket_filter(struct bpf_program *prog); bool bpf_program__is_tracepoint(struct bpf_program *prog); bool bpf_program__is_kprobe(struct bpf_program *prog); bool bpf_program__is_sched_cls(struct bpf_program *prog); bool bpf_program__is_sched_act(struct bpf_program *prog); bool bpf_program__is_xdp(struct bpf_program *prog); bool bpf_program__is_perf_event(struct bpf_program *prog); /* * We don't need __attribute__((packed)) now since it is * unnecessary for 'bpf_map_def' because they are all aligned. * In addition, using it will trigger -Wpacked warning message, * and will be treated as an error due to -Werror. */ struct bpf_map_def { unsigned int type; unsigned int key_size; unsigned int value_size; unsigned int max_entries; unsigned int map_flags; }; /* * There is another 'struct bpf_map' in include/linux/map.h. However, * it is not a uapi header so no need to consider name clash. */ struct bpf_map; struct bpf_map * bpf_object__find_map_by_name(struct bpf_object *obj, const char *name); /* * Get bpf_map through the offset of corresponding struct bpf_map_def * in the bpf object file. */ struct bpf_map * bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset); struct bpf_map * bpf_map__next(struct bpf_map *map, struct bpf_object *obj); #define bpf_map__for_each(pos, obj) \ for ((pos) = bpf_map__next(NULL, (obj)); \ (pos) != NULL; \ (pos) = bpf_map__next((pos), (obj))) int bpf_map__fd(struct bpf_map *map); const struct bpf_map_def *bpf_map__def(struct bpf_map *map); const char *bpf_map__name(struct bpf_map *map); typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *); int bpf_map__set_priv(struct bpf_map *map, void *priv, bpf_map_clear_priv_t clear_priv); void *bpf_map__priv(struct bpf_map *map); int bpf_map__pin(struct bpf_map *map, const char *path); long libbpf_get_error(const void *ptr); int bpf_prog_load(const char *file, enum bpf_prog_type type, struct bpf_object **pobj, int *prog_fd); #endif