From: Carlos <cneirabus...@gmail.com>
Added self-tests for new helper bpf_get_current_pidns_info.
Signed-off-by: Carlos Neira <cneirabus...@gmail.com>
---
tools/include/uapi/linux/bpf.h | 31 ++++-
tools/testing/selftests/bpf/Makefile | 2 +-
tools/testing/selftests/bpf/bpf_helpers.h | 3 +
.../testing/selftests/bpf/progs/test_pidns_kern.c | 51 ++++++++
tools/testing/selftests/bpf/test_pidns.c | 138 +++++++++++++++++++++
5 files changed, 223 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/bpf/progs/test_pidns_kern.c
create mode 100644 tools/testing/selftests/bpf/test_pidns.c
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 4393bd4b2419..db241857ec15 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2741,6 +2741,28 @@ union bpf_attr {
* **-EOPNOTSUPP** kernel configuration does not enable SYN cookies
*
* **-EPROTONOSUPPORT** IP packet version is not 4 or 6
+ *
+ * int bpf_get_current_pidns_info(struct bpf_pidns_info *pidns, u32
size_of_pidns)
+ * Description
+ * Copies into *pidns* pid, namespace id and tgid as seen by the
+ * current namespace and also device from /proc/self/ns/pid.
+ * *size_of_pidns* must be the size of *pidns*
+ *
+ * This helper is used when pid filtering is needed inside a
+ * container as bpf_get_current_tgid() helper returns always the
+ * pid id as seen by the root namespace.
+ * Return
+ * 0 on success
+ *
+ * **-EINVAL** if *size_of_pidns* is not valid or unable to get
ns, pid
+ * or tgid of the current task.
+ *
+ * **-ECHILD** if /proc/self/ns/pid does not exists.
+ *
+ * **-ENOTDIR** if /proc/self/ns does not exists.
+ *
+ * **-ENOMEM** if allocation fails.
+ *
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2853,7 +2875,8 @@ union bpf_attr {
FN(sk_storage_get), \
FN(sk_storage_delete), \
FN(send_signal), \
- FN(tcp_gen_syncookie),
+ FN(tcp_gen_syncookie), \
+ FN(get_current_pidns_info),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -3604,4 +3627,10 @@ struct bpf_sockopt {
__s32 retval;
};
+struct bpf_pidns_info {
+ __u32 dev;
+ __u32 nsid;
+ __u32 tgid;
+ __u32 pid;
+};
#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/tools/testing/selftests/bpf/Makefile
b/tools/testing/selftests/bpf/Makefile
index 3bd0f4a0336a..1f97b571b581 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -29,7 +29,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps
test_lru_map test_lpm_map test
test_cgroup_storage test_select_reuseport test_section_names \
test_netcnt test_tcpnotify_user test_sock_fields test_sysctl
test_hashmap \
test_btf_dump test_cgroup_attach xdping test_sockopt test_sockopt_sk \
- test_sockopt_multi test_tcp_rtt
+ test_sockopt_multi test_tcp_rtt test_pidns
BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c)))
TEST_GEN_FILES = $(BPF_OBJ_FILES)
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h
b/tools/testing/selftests/bpf/bpf_helpers.h
index 8b503ea142f0..3fae3b9fcd2c 100644
--- a/tools/testing/selftests/bpf/bpf_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -231,6 +231,9 @@ static int (*bpf_send_signal)(unsigned sig) = (void
*)BPF_FUNC_send_signal;
static long long (*bpf_tcp_gen_syncookie)(struct bpf_sock *sk, void *ip,
int ip_len, void *tcp, int tcp_len) =
(void *) BPF_FUNC_tcp_gen_syncookie;
+static int (*bpf_get_current_pidns_info)(struct bpf_pidns_info *buf,
+ unsigned int buf_size) =
+ (void *) BPF_FUNC_get_current_pidns_info;
/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions
diff --git a/tools/testing/selftests/bpf/progs/test_pidns_kern.c
b/tools/testing/selftests/bpf/progs/test_pidns_kern.c
new file mode 100644
index 000000000000..e1d2facfa762
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_pidns_kern.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018 Carlos Neira cneirabus...@gmail.com
+ *
+ * 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/bpf.h>
+#include <errno.h>
+#include "bpf_helpers.h"
+
+struct bpf_map_def SEC("maps") nsidmap = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(__u32),
+ .max_entries = 1,
+};
+
+struct bpf_map_def SEC("maps") pidmap = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(__u32),
+ .max_entries = 1,
+};
+
+SEC("tracepoint/syscalls/sys_enter_nanosleep")
+int trace(void *ctx)
+{
+ struct bpf_pidns_info nsinfo;
+ __u32 key = 0, *expected_pid, *val;
+ char fmt[] = "ERROR nspid:%d\n";
+
+ if (bpf_get_current_pidns_info(&nsinfo, sizeof(nsinfo)))
+ return -EINVAL;
+
+ expected_pid = bpf_map_lookup_elem(&pidmap, &key);
+
+
+ if (!expected_pid || *expected_pid != nsinfo.pid)
+ return 0;
+
+ val = bpf_map_lookup_elem(&nsidmap, &key);
+ if (val)
+ *val = nsinfo.nsid;
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+__u32 _version SEC("version") = 1;
diff --git a/tools/testing/selftests/bpf/test_pidns.c
b/tools/testing/selftests/bpf/test_pidns.c
new file mode 100644
index 000000000000..a7254055f294
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_pidns.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2018 Carlos Neira cneirabus...@gmail.com
+ *
+ * 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 <errno.h>
+#include <fcntl.h>
+#include <syscall.h>
+#include <unistd.h>
+#include <linux/perf_event.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "cgroup_helpers.h"
+#include "bpf_rlimit.h"
+
+#define CHECK(condition, tag, format...) ({ \
+ int __ret = !!(condition); \
+ if (__ret) { \
+ printf("%s:FAIL:%s ", __func__, tag); \
+ printf(format); \
+ } else { \
+ printf("%s:PASS:%s\n", __func__, tag); \
+ } \
+ __ret; \
+})
+
+static int bpf_find_map(const char *test, struct bpf_object *obj,
+ const char *name)
+{
+ struct bpf_map *map;
+
+ map = bpf_object__find_map_by_name(obj, name);
+ if (!map)
+ return -1;
+ return bpf_map__fd(map);
+}
+
+
+int main(int argc, char **argv)
+{
+ const char *probe_name = "syscalls/sys_enter_nanosleep";
+ const char *file = "test_pidns_kern.o";
+ int err, bytes, efd, prog_fd, pmu_fd;
+ int pidmap_fd, nsidmap_fd;
+ struct perf_event_attr attr = {};
+ struct bpf_object *obj;
+ __u32 knsid = 0;
+ __u32 key = 0, pid;
+ int exit_code = 1;
+ struct stat st;
+ char buf[256];
+
+ err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd);
+ if (CHECK(err, "bpf_prog_load", "err %d errno %d\n", err, errno))
+ goto cleanup_cgroup_env;
+
+ nsidmap_fd = bpf_find_map(__func__, obj, "nsidmap");
+ if (CHECK(nsidmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
+ nsidmap_fd, errno))
+ goto close_prog;
+
+ pidmap_fd = bpf_find_map(__func__, obj, "pidmap");
+ if (CHECK(pidmap_fd < 0, "bpf_find_map", "err %d errno %d\n",
+ pidmap_fd, errno))
+ goto close_prog;
+
+ pid = getpid();
+ bpf_map_update_elem(pidmap_fd, &key, &pid, 0);
+
+ snprintf(buf, sizeof(buf),
+ "/sys/kernel/debug/tracing/events/%s/id", probe_name);
+ efd = open(buf, O_RDONLY, 0);
+ if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno))
+ goto close_prog;
+ bytes = read(efd, buf, sizeof(buf));
+ close(efd);
+ if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read",
+ "bytes %d errno %d\n", bytes, errno))
+ goto close_prog;
+
+ attr.config = strtol(buf, NULL, 0);
+ attr.type = PERF_TYPE_TRACEPOINT;
+ attr.sample_type = PERF_SAMPLE_RAW;
+ attr.sample_period = 1;
+ attr.wakeup_events = 1;
+
+ pmu_fd = syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0);
+ if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd,
+ errno))
+ goto close_prog;
+
+ err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
+ if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err,
+ errno))
+ goto close_pmu;
+
+ err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
+ if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err,
+ errno))
+ goto close_pmu;
+
+ /* trigger some syscalls */
+ sleep(1);
+
+ err = bpf_map_lookup_elem(nsidmap_fd, &key, &knsid);
+ if (CHECK(err, "bpf_map_lookup_elem", "err %d errno %d\n", err, errno))
+ goto close_pmu;
+
+ if (stat("/proc/self/ns/pid", &st))
+ goto close_pmu;
+
+ if (CHECK(knsid != (__u32) st.st_ino, "compare_namespace_id",
+ "kern knsid %u user unsid %u\n", knsid, (__u32) st.st_ino))
+ goto close_pmu;
+
+ exit_code = 0;
+ printf("%s:PASS\n", argv[0]);
+
+close_pmu:
+ close(pmu_fd);
+close_prog:
+ bpf_object__close(obj);
+cleanup_cgroup_env:
+ return exit_code;
+}
--
2.11.0
