a3f7461734
test_cgrp2_array_pin.c: A userland program that creates a bpf_map (BPF_MAP_TYPE_GROUP_ARRAY), pouplates/updates it with a cgroup2's backed fd and pins it to a bpf-fs's file. The pinned file can be loaded by tc and then used by the bpf prog later. This program can also update an existing pinned array and it could be useful for debugging/testing purpose. test_cgrp2_tc_kern.c: A bpf prog which should be loaded by tc. It is to demonstrate the usage of bpf_skb_in_cgroup. test_cgrp2_tc.sh: A script that glues the test_cgrp2_array_pin.c and test_cgrp2_tc_kern.c together. The idea is like: 1. Load the test_cgrp2_tc_kern.o by tc 2. Use test_cgrp2_array_pin.c to populate a BPF_MAP_TYPE_CGROUP_ARRAY with a cgroup fd 3. Do a 'ping -6 ff02::1%ve' to ensure the packet has been dropped because of a match on the cgroup Most of the lines in test_cgrp2_tc.sh is the boilerplate to setup the cgroup/bpf-fs/net-devices/netns...etc. It is not bulletproof on errors but should work well enough and give enough debug info if things did not go well. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Tejun Heo <tj@kernel.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
109 lines
2.2 KiB
C
109 lines
2.2 KiB
C
/* Copyright (c) 2016 Facebook
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*/
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#include <linux/unistd.h>
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#include <linux/bpf.h>
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#include <stdio.h>
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#include <stdint.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <fcntl.h>
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#include "libbpf.h"
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static void usage(void)
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{
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printf("Usage: test_cgrp2_array_pin [...]\n");
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printf(" -F <file> File to pin an BPF cgroup array\n");
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printf(" -U <file> Update an already pinned BPF cgroup array\n");
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printf(" -v <value> Full path of the cgroup2\n");
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printf(" -h Display this help\n");
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}
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int main(int argc, char **argv)
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{
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const char *pinned_file = NULL, *cg2 = NULL;
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int create_array = 1;
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int array_key = 0;
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int array_fd = -1;
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int cg2_fd = -1;
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int ret = -1;
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int opt;
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while ((opt = getopt(argc, argv, "F:U:v:")) != -1) {
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switch (opt) {
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/* General args */
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case 'F':
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pinned_file = optarg;
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break;
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case 'U':
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pinned_file = optarg;
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create_array = 0;
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break;
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case 'v':
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cg2 = optarg;
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break;
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default:
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usage();
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goto out;
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}
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}
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if (!cg2 || !pinned_file) {
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usage();
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goto out;
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}
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cg2_fd = open(cg2, O_RDONLY);
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if (cg2_fd < 0) {
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fprintf(stderr, "open(%s,...): %s(%d)\n",
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cg2, strerror(errno), errno);
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goto out;
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}
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if (create_array) {
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array_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,
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sizeof(uint32_t), sizeof(uint32_t),
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1, 0);
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if (array_fd < 0) {
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fprintf(stderr,
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"bpf_create_map(BPF_MAP_TYPE_CGROUP_ARRAY,...): %s(%d)\n",
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strerror(errno), errno);
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goto out;
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}
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} else {
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array_fd = bpf_obj_get(pinned_file);
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if (array_fd < 0) {
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fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
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pinned_file, strerror(errno), errno);
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goto out;
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}
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}
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ret = bpf_update_elem(array_fd, &array_key, &cg2_fd, 0);
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if (ret) {
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perror("bpf_update_elem");
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goto out;
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}
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if (create_array) {
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ret = bpf_obj_pin(array_fd, pinned_file);
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if (ret) {
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fprintf(stderr, "bpf_obj_pin(..., %s): %s(%d)\n",
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pinned_file, strerror(errno), errno);
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goto out;
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}
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}
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out:
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if (array_fd != -1)
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close(array_fd);
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if (cg2_fd != -1)
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close(cg2_fd);
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return ret;
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}
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