The program load_sock_ops can be used to load sock_ops bpf programs and
to attach it to an existing (v2) cgroup. It can also be used to detach
sock_ops programs.
Examples:
load_sock_ops [-l] <cg-path> <prog filename>
Load and attaches a sock_ops program at the specified cgroup.
If "-l" is used, the program will continue to run to output the
BPF log buffer.
If the specified filename does not end in ".o", it appends
"_kern.o" to the name.
load_sock_ops -r <cg-path>
Detaches the currently attached sock_ops program from the
specified cgroup.
Signed-off-by: Lawrence Brakmo <bra...@fb.com>
Acked-by: Daniel Borkmann <dan...@iogearbox.net>
---
samples/bpf/Makefile | 3 ++
samples/bpf/load_sock_ops.c | 97 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 100 insertions(+)
create mode 100644 samples/bpf/load_sock_ops.c
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index e7ec9b8..015589b 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -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
diff --git a/samples/bpf/load_sock_ops.c b/samples/bpf/load_sock_ops.c
new file mode 100644
index 0000000..e5da6cf
--- /dev/null
+++ b/samples/bpf/load_sock_ops.c
@@ -0,0 +1,97 @@
+/* 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;
+}
--
2.9.3
