Commit 74b38819 authored by Daniel Borkmann's avatar Daniel Borkmann
Browse files

Merge branch 'bpf-samples-improvements' 



Jakub Kicinski says:

====================
This set is next part of a quest to get rid of the bpf_load
ELF loader.  It fixes some minor issues with the samples and
starts the conversion.

First patch fixes ping invocations, ping localhost defaults
to IPv6 on modern setups. Next load_sock_ops sample is removed
and users are directed towards using bpftool directly.

Patch 4 removes the use of bpf_load from samples which don't
need the auto-attachment functionality at all.

Patch 5 improves symbol counting in libbpf, it's not currently
an issue but it will be when anyone adds a symbol with a long
name. Let's make sure that person doesn't have to spend time
scratching their head and wondering why .a and .so symbol
counts don't match.

v2: - specify prog_type where possible (Andrii).
====================

Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parents ebace0e9 771744f9

samples/bpf/.gitignore

+0 −1
Original line number Diff line number Diff line 
cpustat

fds_example

lathist

load_sock_ops

lwt_len_hist

map_perf_test

offwaketime

samples/bpf/Makefile

+3 −5
Original line number Diff line number Diff line
@@ -40,7 +40,6 @@ hostprogs-y += lwt_len_hist 
hostprogs-y += xdp_tx_iptunnel

hostprogs-y += test_map_in_map

hostprogs-y += per_socket_stats_example

hostprogs-y += load_sock_ops

hostprogs-y += xdp_redirect

hostprogs-y += xdp_redirect_map

hostprogs-y += xdp_redirect_cpu
@@ -60,9 +59,9 @@ LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a 
CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o

TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o



fds_example-objs := bpf_load.o fds_example.o

sockex1-objs := bpf_load.o sockex1_user.o

sockex2-objs := bpf_load.o sockex2_user.o

fds_example-objs := fds_example.o

sockex1-objs := sockex1_user.o

sockex2-objs := sockex2_user.o

sockex3-objs := bpf_load.o sockex3_user.o

tracex1-objs := bpf_load.o tracex1_user.o

tracex2-objs := bpf_load.o tracex2_user.o
@@ -71,7 +70,6 @@ tracex4-objs := bpf_load.o tracex4_user.o 
tracex5-objs := bpf_load.o tracex5_user.o

tracex6-objs := bpf_load.o tracex6_user.o

tracex7-objs := bpf_load.o tracex7_user.o

load_sock_ops-objs := bpf_load.o load_sock_ops.o

test_probe_write_user-objs := bpf_load.o test_probe_write_user_user.o

trace_output-objs := bpf_load.o trace_output_user.o $(TRACE_HELPERS)

lathist-objs := bpf_load.o lathist_user.o

samples/bpf/fds_example.c

+7 −3
Original line number Diff line number Diff line
@@ -14,8 +14,8 @@ 


#include <bpf/bpf.h>



#include "bpf/libbpf.h"

#include "bpf_insn.h"

#include "bpf_load.h"

#include "sock_example.h"



#define BPF_F_PIN	(1 << 0)
@@ -57,10 +57,14 @@ static int bpf_prog_create(const char *object) 
		BPF_EXIT_INSN(),

	};

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

	char bpf_log_buf[BPF_LOG_BUF_SIZE];

	struct bpf_object *obj;

	int prog_fd;



	if (object) {

		assert(!load_bpf_file((char *)object));

		return prog_fd[0];

		assert(!bpf_prog_load(object, BPF_PROG_TYPE_UNSPEC,

				      &obj, &prog_fd));

		return prog_fd;

	} else {

		return bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER,

					insns, insns_cnt, "GPL", 0,

samples/bpf/load_sock_ops.c

deleted100644 → 0
+0 −97
Original line number Diff line number Diff line 
/* Copyright (c) 2017 Facebook

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of version 2 of the GNU General Public

 * License as published by the Free Software Foundation.

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <linux/bpf.h>

#include <bpf/bpf.h>

#include "bpf_load.h"

#include <unistd.h>

#include <errno.h>

#include <fcntl.h>

#include <linux/unistd.h>



static void usage(char *pname)

{

	printf("USAGE:\n  %s [-l] <cg-path> <prog filename>\n", pname);

	printf("\tLoad and attach a sock_ops program to the specified "

	       "cgroup\n");

	printf("\tIf \"-l\" is used, the program will continue to run\n");

	printf("\tprinting the BPF log buffer\n");

	printf("\tIf the specified filename does not end in \".o\", it\n");

	printf("\tappends \"_kern.o\" to the name\n");

	printf("\n");

	printf("  %s -r <cg-path>\n", pname);

	printf("\tDetaches the currently attached sock_ops program\n");

	printf("\tfrom the specified cgroup\n");

	printf("\n");

	exit(1);

}



int main(int argc, char **argv)

{

	int logFlag = 0;

	int error = 0;

	char *cg_path;

	char fn[500];

	char *prog;

	int cg_fd;



	if (argc < 3)

		usage(argv[0]);



	if (!strcmp(argv[1], "-r")) {

		cg_path = argv[2];

		cg_fd = open(cg_path, O_DIRECTORY, O_RDONLY);

		error = bpf_prog_detach(cg_fd, BPF_CGROUP_SOCK_OPS);

		if (error) {

			printf("ERROR: bpf_prog_detach: %d (%s)\n",

			       error, strerror(errno));

			return 2;

		}

		return 0;

	} else if (!strcmp(argv[1], "-h")) {

		usage(argv[0]);

	} else if (!strcmp(argv[1], "-l")) {

		logFlag = 1;

		if (argc < 4)

			usage(argv[0]);

	}



	prog = argv[argc - 1];

	cg_path = argv[argc - 2];

	if (strlen(prog) > 480) {

		fprintf(stderr, "ERROR: program name too long (> 480 chars)\n");

		return 3;

	}

	cg_fd = open(cg_path, O_DIRECTORY, O_RDONLY);



	if (!strcmp(prog + strlen(prog)-2, ".o"))

		strcpy(fn, prog);

	else

		sprintf(fn, "%s_kern.o", prog);

	if (logFlag)

		printf("loading bpf file:%s\n", fn);

	if (load_bpf_file(fn)) {

		printf("ERROR: load_bpf_file failed for: %s\n", fn);

		printf("%s", bpf_log_buf);

		return 4;

	}

	if (logFlag)

		printf("TCP BPF Loaded %s\n", fn);



	error = bpf_prog_attach(prog_fd[0], cg_fd, BPF_CGROUP_SOCK_OPS, 0);

	if (error) {

		printf("ERROR: bpf_prog_attach: %d (%s)\n",

		       error, strerror(errno));

		return 5;

	} else if (logFlag) {

		read_trace_pipe();

	}



	return error;

}

samples/bpf/sock_example.c

+1 −1
Original line number Diff line number Diff line
@@ -99,7 +99,7 @@ int main(void) 
{

	FILE *f;



	f = popen("ping -c5 localhost", "r");

	f = popen("ping -4 -c5 localhost", "r");

	(void)f;



	return test_sock();

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