linux-imx

/* eBPF example program:

 *

 * - Creates arraymap in kernel with 4 bytes keys and 8 byte values

 *

 * - Loads eBPF program

 *

 *   The eBPF program accesses the map passed in to store two pieces of

 *   information. The number of invocations of the program, which maps

 *   to the number of packets received, is stored to key 0. Key 1 is

 *   incremented on each iteration by the number of bytes stored in

 *   the skb. The program also stores the number of received bytes

 *   in the cgroup storage.

 *

 * - Attaches the new program to a cgroup using BPF_PROG_ATTACH

 *

 * - Every second, reads map[0] and map[1] to see how many bytes and

 *   packets were seen on any socket of tasks in the given cgroup.

 */

​

#define _GNU_SOURCE

​

#include <stdio.h>

#include <stdlib.h>

#include <assert.h>

#include <sys/resource.h>

#include <sys/time.h>

#include <unistd.h>

​

#include <linux/bpf.h>

#include <bpf/bpf.h>

​

#include "bpf_insn.h"

#include "bpf_rlimit.h"

#include "cgroup_helpers.h"

​

#define FOO     "/foo"

#define BAR     "/foo/bar/"

#define PING_CMD    "ping -c1 -w1 127.0.0.1 > /dev/null"

​

char bpf_log_buf[BPF_LOG_BUF_SIZE];

​

static int prog_load(int verdict)

{

    int ret;

    struct bpf_insn prog[] = {

        BPF_MOV64_IMM(BPF_REG_0, verdict), /* r0 = verdict */

        BPF_EXIT_INSN(),

    };

    size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);

​

    ret = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,

                   prog, insns_cnt, "GPL", 0,

                   bpf_log_buf, BPF_LOG_BUF_SIZE);

​

    if (ret < 0) {

        log_err("Loading program");

        printf("Output from verifier:\n%s\n-------\n", bpf_log_buf);

        return 0;

    }

    return ret;

}

​

static int test_foo_bar(void)