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Diffstat (limited to 'tools/lib/bpf/libbpf.h')
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h new file mode 100644 index 000000000..96c55fac5 --- /dev/null +++ b/tools/lib/bpf/libbpf.h @@ -0,0 +1,300 @@ +/* SPDX-License-Identifier: LGPL-2.1 */ + +/* + * Common eBPF ELF object loading operations. + * + * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> + * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> + * 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 <http://www.gnu.org/licenses> + */ +#ifndef __BPF_LIBBPF_H +#define __BPF_LIBBPF_H + +#include <stdio.h> +#include <stdint.h> +#include <stdbool.h> +#include <sys/types.h> // for size_t +#include <linux/bpf.h> + +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__WRNGPID, /* Wrong pid in netlink message */ + LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */ + __LIBBPF_ERRNO__END, +}; + +int libbpf_strerror(int err, char *buf, size_t size); + +/* + * __printf is defined in include/linux/compiler-gcc.h. However, + * it would be better if libbpf.h didn't depend on Linux header files. + * 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_open_attr { + const char *file; + enum bpf_prog_type prog_type; +}; + +struct bpf_object *bpf_object__open(const char *path); +struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr); +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); +int bpf_object__btf_fd(const struct bpf_object *obj); + +struct bpf_program * +bpf_object__find_program_by_title(struct bpf_object *obj, const char *title); + +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); + +int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, + enum bpf_attach_type *expected_attach_type); + +/* 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); +void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex); + +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 transformed into + * multiple variants to be attached to different hooks. + * + * bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd + * form an API for this purpose. + * + * - bpf_program_prep_t: + * Defines a '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 instance according to the instance id + * passed to it. + * + * - bpf_program__set_prep: + * Attaches a preprocessor to a BPF program. The number of instances + * that should be created is also passed through this function. + * + * - bpf_program__nth_fd: + * After the program is loaded, get resulting FD of a given instance + * of the BPF program. + * + * If bpf_program__set_prep() is not used, the program would 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 written 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 error, 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_raw_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); +void bpf_program__set_expected_attach_type(struct bpf_program *prog, + enum bpf_attach_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_raw_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); + +/* + * No need for __attribute__((packed)), all members of 'bpf_map_def' + * are all aligned. In addition, using __attribute__((packed)) + * would trigger a -Wpacked warning message, and lead to an error + * if -Werror is set. + */ +struct bpf_map_def { + unsigned int type; + unsigned int key_size; + unsigned int value_size; + unsigned int max_entries; + unsigned int map_flags; +}; + +/* + * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel, + * so no need to worry about a 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); +__u32 bpf_map__btf_key_type_id(const struct bpf_map *map); +__u32 bpf_map__btf_value_type_id(const 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__reuse_fd(struct bpf_map *map, int fd); +bool bpf_map__is_offload_neutral(struct bpf_map *map); +void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); +int bpf_map__pin(struct bpf_map *map, const char *path); + +long libbpf_get_error(const void *ptr); + +struct bpf_prog_load_attr { + const char *file; + enum bpf_prog_type prog_type; + enum bpf_attach_type expected_attach_type; + int ifindex; +}; + +int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, + struct bpf_object **pobj, int *prog_fd); +int bpf_prog_load(const char *file, enum bpf_prog_type type, + struct bpf_object **pobj, int *prog_fd); + +int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags); + +enum bpf_perf_event_ret { + LIBBPF_PERF_EVENT_DONE = 0, + LIBBPF_PERF_EVENT_ERROR = -1, + LIBBPF_PERF_EVENT_CONT = -2, +}; + +typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(void *event, + void *priv); +int bpf_perf_event_read_simple(void *mem, unsigned long size, + unsigned long page_size, + void **buf, size_t *buf_len, + bpf_perf_event_print_t fn, void *priv); +#endif |