bpf: program to load and attach sock_ops BPF progs (ae16189e) · Commits · 戴 / test

samples/bpf/Makefile

+3 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@ 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

		# Libbpf dependencies
		LIBBPF := ../../tools/lib/bpf/bpf.o
		@@ -52,6 +53,7 @@ tracex3-objs := bpf_load.o $(LIBBPF) tracex3_user.o
		tracex4-objs := bpf_load.o $(LIBBPF) tracex4_user.o
		tracex5-objs := bpf_load.o $(LIBBPF) tracex5_user.o
		tracex6-objs := bpf_load.o $(LIBBPF) tracex6_user.o
		load_sock_ops-objs := bpf_load.o $(LIBBPF) load_sock_ops.o
		test_probe_write_user-objs := bpf_load.o $(LIBBPF) test_probe_write_user_user.o
		trace_output-objs := bpf_load.o $(LIBBPF) trace_output_user.o
		lathist-objs := bpf_load.o $(LIBBPF) lathist_user.o
		@@ -130,6 +132,7 @@ HOSTLOADLIBES_tracex4 += -lelf -lrt
		HOSTLOADLIBES_tracex5 += -lelf
		HOSTLOADLIBES_tracex6 += -lelf
		HOSTLOADLIBES_test_cgrp2_sock2 += -lelf
		HOSTLOADLIBES_load_sock_ops += -lelf
		HOSTLOADLIBES_test_probe_write_user += -lelf
		HOSTLOADLIBES_trace_output += -lelf -lrt
		HOSTLOADLIBES_lathist += -lelf

samples/bpf/load_sock_ops.c

0 → 100644

+97 −0

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 "libbpf.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;
		}

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