LXR linux/tools/lib/bpf/skel

   1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
   2/* Copyright (c) 2021 Facebook */
   3#ifndef __SKEL_INTERNAL_H
   4#define __SKEL_INTERNAL_H
   5
   6#include <unistd.h>
   7#include <sys/syscall.h>
   8#include <sys/mman.h>
   9
  10/* This file is a base header for auto-generated *.lskel.h files.
  11 * Its contents will change and may become part of auto-generation in the future.
  12 *
  13 * The layout of bpf_[map|prog]_desc and bpf_loader_ctx is feature dependent
  14 * and will change from one version of libbpf to another and features
  15 * requested during loader program generation.
  16 */
  17struct bpf_map_desc {
  18        union {
  19                /* input for the loader prog */
  20                struct {
  21                        __aligned_u64 initial_value;
  22                        __u32 max_entries;
  23                };
  24                /* output of the loader prog */
  25                struct {
  26                        int map_fd;
  27                };
  28        };
  29};
  30struct bpf_prog_desc {
  31        int prog_fd;
  32};
  33
  34struct bpf_loader_ctx {
  35        size_t sz;
  36        __u32 log_level;
  37        __u32 log_size;
  38        __u64 log_buf;
  39};
  40
  41struct bpf_load_and_run_opts {
  42        struct bpf_loader_ctx *ctx;
  43        const void *data;
  44        const void *insns;
  45        __u32 data_sz;
  46        __u32 insns_sz;
  47        const char *errstr;
  48};
  49
  50static inline int skel_sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
  51                          unsigned int size)
  52{
  53        return syscall(__NR_bpf, cmd, attr, size);
  54}
  55
  56static inline int skel_closenz(int fd)
  57{
  58        if (fd > 0)
  59                return close(fd);
  60        return -EINVAL;
  61}
  62
  63static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
  64{
  65        int map_fd = -1, prog_fd = -1, key = 0, err;
  66        union bpf_attr attr;
  67
  68        map_fd = bpf_create_map_name(BPF_MAP_TYPE_ARRAY, "__loader.map", 4,
  69                                     opts->data_sz, 1, 0);
  70        if (map_fd < 0) {
  71                opts->errstr = "failed to create loader map";
  72                err = -errno;
  73                goto out;
  74        }
  75
  76        err = bpf_map_update_elem(map_fd, &key, opts->data, 0);
  77        if (err < 0) {
  78                opts->errstr = "failed to update loader map";
  79                err = -errno;
  80                goto out;
  81        }
  82
  83        memset(&attr, 0, sizeof(attr));
  84        attr.prog_type = BPF_PROG_TYPE_SYSCALL;
  85        attr.insns = (long) opts->insns;
  86        attr.insn_cnt = opts->insns_sz / sizeof(struct bpf_insn);
  87        attr.license = (long) "Dual BSD/GPL";
  88        memcpy(attr.prog_name, "__loader.prog", sizeof("__loader.prog"));
  89        attr.fd_array = (long) &map_fd;
  90        attr.log_level = opts->ctx->log_level;
  91        attr.log_size = opts->ctx->log_size;
  92        attr.log_buf = opts->ctx->log_buf;
  93        attr.prog_flags = BPF_F_SLEEPABLE;
  94        prog_fd = skel_sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr));
  95        if (prog_fd < 0) {
  96                opts->errstr = "failed to load loader prog";
  97                err = -errno;
  98                goto out;
  99        }
 100
 101        memset(&attr, 0, sizeof(attr));
 102        attr.test.prog_fd = prog_fd;
 103        attr.test.ctx_in = (long) opts->ctx;
 104        attr.test.ctx_size_in = opts->ctx->sz;
 105        err = skel_sys_bpf(BPF_PROG_RUN, &attr, sizeof(attr));
 106        if (err < 0 || (int)attr.test.retval < 0) {
 107                opts->errstr = "failed to execute loader prog";
 108                if (err < 0)
 109                        err = -errno;
 110                else
 111                        err = (int)attr.test.retval;
 112                goto out;
 113        }
 114        err = 0;
 115out:
 116        if (map_fd >= 0)
 117                close(map_fd);
 118        if (prog_fd >= 0)
 119                close(prog_fd);
 120        return err;
 121}
 122
 123#endif
 124