// SPDX-License-Identifier: GPL-2.0 /* eBPF example program: * * - Loads eBPF program * * The eBPF program loads a filter from file and attaches the * program to a cgroup using BPF_PROG_ATTACH */ #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <stddef.h> #include <string.h> #include <unistd.h> #include <assert.h> #include <errno.h> #include <fcntl.h> #include <net/if.h> #include <linux/bpf.h> #include <bpf/bpf.h> #include "bpf_insn.h" #include "bpf_load.h" static int usage(const char *argv0) { printf("Usage: %s cg-path filter-path [filter-id]\n", argv0); return EXIT_FAILURE; } int main(int argc, char **argv) { int cg_fd, ret, filter_id = 0; if (argc < 3) return usage(argv[0]); cg_fd = open(argv[1], O_DIRECTORY | O_RDONLY); if (cg_fd < 0) { printf("Failed to open cgroup path: '%s'\n", strerror(errno)); return EXIT_FAILURE; } if (load_bpf_file(argv[2])) return EXIT_FAILURE; printf("Output from kernel verifier:\n%s\n-------\n", bpf_log_buf); if (argc > 3) filter_id = atoi(argv[3]); if (filter_id >= prog_cnt) { printf("Invalid program id; program not found in file\n"); return EXIT_FAILURE; } ret = bpf_prog_attach(prog_fd[filter_id], cg_fd, BPF_CGROUP_INET_SOCK_CREATE, 0); if (ret < 0) { printf("Failed to attach prog to cgroup: '%s'\n", strerror(errno)); return EXIT_FAILURE; } return EXIT_SUCCESS; }