strace/tests/bpf.c

/*
 * Copyright (c) 2015-2016 Dmitry V. Levin <ldv@altlinux.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "tests.h"
#include <stdio.h>
#include <stdint.h>
#include <unistd.h>
#include <asm/unistd.h>

#if defined HAVE_UNION_BPF_ATTR_LOG_BUF && defined __NR_bpf
# include <linux/bpf.h>

static const struct bpf_insn insns[] = {
	{ .code = BPF_JMP | BPF_EXIT }
};

static char log_buf[4096];

static int
map_create(void)
{
	union bpf_attr attr = {
		.key_size = 4,
		.value_size = 8,
		.max_entries = 256
	};
	return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
}

static int
map_any(int cmd)
{
	union bpf_attr attr = {
		.map_fd = -1,
		.key = 0xdeadbeef,
		.value = 0xbadc0ded
	};
	return syscall(__NR_bpf, cmd, &attr, sizeof(attr));
}

static int
prog_load(void)
{
	union bpf_attr attr = {
		.insn_cnt = sizeof(insns) / sizeof(insns[0]),
		.insns = (unsigned long) insns,
		.license = (unsigned long) "GPL",
		.log_level = 42,
		.log_size = sizeof(log_buf),
		.log_buf = (unsigned long) log_buf
	};
	return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
}

int
main(void)
{
	if (!map_create())
		perror_msg_and_skip("BPF_MAP_CREATE");
	printf("bpf\\(BPF_MAP_CREATE, "
	       "\\{map_type=BPF_MAP_TYPE_UNSPEC, key_size=4, value_size=8, max_entries=256\\}, "
	       "%u\\) += -1 .*\n",
		(unsigned) sizeof(union bpf_attr));

	if (!map_any(BPF_MAP_LOOKUP_ELEM))
		perror_msg_and_skip("BPF_MAP_LOOKUP_ELEM");
	printf("bpf\\(BPF_MAP_LOOKUP_ELEM, "
	       "\\{map_fd=-1, key=0xdeadbeef\\}, %u\\) += -1 .*\n",
		(unsigned) sizeof(union bpf_attr));

	if (!map_any(BPF_MAP_UPDATE_ELEM))
		perror_msg_and_skip("BPF_MAP_UPDATE_ELEM");
	printf("bpf\\(BPF_MAP_UPDATE_ELEM, "
	       "\\{map_fd=-1, key=0xdeadbeef, value=0xbadc0ded, flags=BPF_ANY\\}, "
	       "%u\\) += -1 .*\n",
		(unsigned) sizeof(union bpf_attr));

	if (!map_any(BPF_MAP_DELETE_ELEM))
		perror_msg_and_skip("BPF_MAP_DELETE_ELEM");
	printf("bpf\\(BPF_MAP_DELETE_ELEM, "
	       "\\{map_fd=-1, key=0xdeadbeef\\}, %u\\) += -1 .*\n",
		(unsigned) sizeof(union bpf_attr));

	if (!map_any(BPF_MAP_GET_NEXT_KEY))
		perror_msg_and_skip("BPF_MAP_GET_NEXT_KEY");
	printf("bpf\\(BPF_MAP_GET_NEXT_KEY, "
	       "\\{map_fd=-1, key=0xdeadbeef\\}, %u\\) += -1 .*\n",
		(unsigned) sizeof(union bpf_attr));

	if (!prog_load())
		perror_msg_and_skip("BPF_PROG_LOAD");
	printf("bpf\\(BPF_PROG_LOAD, "
	       "\\{prog_type=BPF_PROG_TYPE_UNSPEC, insn_cnt=1, insns=%p, "
	       "license=\"GPL\", log_level=42, log_size=4096, log_buf=%p, "
	       "kern_version=0\\}, %u\\) += -1 .*\n",
		insns, log_buf, (unsigned) sizeof(union bpf_attr));

	return 0;
}

#else

SKIP_MAIN_UNDEFINED("__NR_bpf")

#endif