From: Carlos <cneirabustos@xxxxxxxxx>
sample program to call new bpf helper bpf_get_current_pidns_info.
Signed-off-by: Carlos Neira <cneirabustos@xxxxxxxxx>
---
samples/bpf/Makefile | 3 +++
samples/bpf/trace_ns_info_user.c | 35 ++++++++++++++++++++++++++++
samples/bpf/trace_ns_info_user_kern.c | 44 +++++++++++++++++++++++++++++++++++
3 files changed, 82 insertions(+)
create mode 100644 samples/bpf/trace_ns_info_user.c
create mode 100644 samples/bpf/trace_ns_info_user_kern.c
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 1d9be26b4edd..238453ff27d2 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -53,6 +53,7 @@ hostprogs-y += task_fd_query
hostprogs-y += xdp_sample_pkts
hostprogs-y += ibumad
hostprogs-y += hbm
+hostprogs-y += trace_ns_info
# Libbpf dependencies
LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a
@@ -109,6 +110,7 @@ task_fd_query-objs := bpf_load.o task_fd_query_user.o $(TRACE_HELPERS)
xdp_sample_pkts-objs := xdp_sample_pkts_user.o $(TRACE_HELPERS)
ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS)
hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS)
+trace_ns_info-objs := bpf_load.o trace_ns_info_user.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
@@ -170,6 +172,7 @@ always += xdp_sample_pkts_kern.o
always += ibumad_kern.o
always += hbm_out_kern.o
always += hbm_edt_kern.o
+always += trace_ns_info_user_kern.o
KBUILD_HOSTCFLAGS += -I$(objtree)/usr/include
KBUILD_HOSTCFLAGS += -I$(srctree)/tools/lib/bpf/
diff --git a/samples/bpf/trace_ns_info_user.c b/samples/bpf/trace_ns_info_user.c
new file mode 100644
index 000000000000..e06d08db6f30
--- /dev/null
+++ b/samples/bpf/trace_ns_info_user.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018 Carlos Neira cneirabustos@xxxxxxxxx
+ *
+ * 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 <linux/bpf.h>
+#include <unistd.h>
+#include "bpf/libbpf.h"
+#include "bpf_load.h"
+
+/* This code was taken verbatim from tracex1_user.c, it's used
+ * to exercize bpf_get_current_pidns_info() helper call.
+ */
+int main(int ac, char **argv)
+{
+ FILE *f;
+ char filename[256];
+
+ snprintf(filename, sizeof(filename), "%s_user_kern.o", argv[0]);
+ printf("loading %s\n", filename);
+
+ if (load_bpf_file(filename)) {
+ printf("%s", bpf_log_buf);
+ return 1;
+ }
+
+ f = popen("taskset 1 ping localhost", "r");
+ (void) f;
+ read_trace_pipe();
+ return 0;
+}
diff --git a/samples/bpf/trace_ns_info_user_kern.c b/samples/bpf/trace_ns_info_user_kern.c
new file mode 100644
index 000000000000..96675e02b707
--- /dev/null
+++ b/samples/bpf/trace_ns_info_user_kern.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018 Carlos Neira cneirabustos@xxxxxxxxx
+ *
+ * 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 <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/version.h>
+#include <uapi/linux/bpf.h>
+#include "bpf_helpers.h"
+
+typedef __u64 u64;
+typedef __u32 u32;
+
+
+/* kprobe is NOT a stable ABI
+ * kernel functions can be removed, renamed or completely change semantics.
+ * Number of arguments and their positions can change, etc.
+ * In such case this bpf+kprobe example will no longer be meaningful
+ */
+
+/* This will call bpf_get_current_pidns_info() to display pid and ns values
+ * as seen by the current namespace, on the far left you will see the pid as
+ * seen as by the root namespace.
+ */
+
+SEC("kprobe/__netif_receive_skb_core")
+int bpf_prog1(struct pt_regs *ctx)
+{
+ char fmt[] = "nsid:%u, dev: %u, pid:%u\n";
+ struct bpf_pidns_info nsinfo;
+ int ok = 0;
+
+ ok = bpf_get_current_pidns_info(&nsinfo, sizeof(nsinfo));
+ if (ok == 0)
+ bpf_trace_printk(fmt, sizeof(fmt), (u32)nsinfo.nsid,
+ (u32) nsinfo.dev, (u32)nsinfo.pid);
+
+ return 0;
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
--
2.11.0
