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