From 1c1052e0140af8f211c283c0a333ecff2a6edfc9 Mon Sep 17 00:00:00 2001 From: Carlos Neira Date: Wed, 4 Mar 2020 17:41:57 -0300 Subject: [PATCH] tools/testing/selftests/bpf: Add self-tests for new helper bpf_get_ns_current_pid_tgid. Self tests added for new helper bpf_get_ns_current_pid_tgid Signed-off-by: Carlos Neira Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200304204157.58695-4-cneirabustos@gmail.com --- tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 3 +- .../selftests/bpf/prog_tests/ns_current_pid_tgid.c | 88 ++++++++++++ .../selftests/bpf/progs/test_ns_current_pid_tgid.c | 37 +++++ .../selftests/bpf/test_current_pid_tgid_new_ns.c | 159 +++++++++++++++++++++ 5 files changed, 287 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c create mode 100644 tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c create mode 100644 tools/testing/selftests/bpf/test_current_pid_tgid_new_ns.c diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index ec46485..2198cd8 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -31,6 +31,7 @@ test_tcp_check_syncookie_user test_sysctl test_hashmap test_btf_dump +test_current_pid_tgid_new_ns xdping test_cpp *.skel.h diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index ee4ad34..da4389d 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -32,7 +32,8 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test test_sock test_btf test_sockmap get_cgroup_id_user test_socket_cookie \ test_cgroup_storage \ test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ - test_progs-no_alu32 + test_progs-no_alu32 \ + test_current_pid_tgid_new_ns # Also test bpf-gcc, if present ifneq ($(BPF_GCC),) diff --git a/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c b/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c new file mode 100644 index 0000000..542240e --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Carlos Neira cneirabustos@gmail.com */ +#include +#include +#include +#include +#include + +struct bss { + __u64 dev; + __u64 ino; + __u64 pid_tgid; + __u64 user_pid_tgid; +}; + +void test_ns_current_pid_tgid(void) +{ + const char *probe_name = "raw_tracepoint/sys_enter"; + const char *file = "test_ns_current_pid_tgid.o"; + int err, key = 0, duration = 0; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_map *bss_map; + struct bpf_object *obj; + struct bss bss; + struct stat st; + __u64 id; + + obj = bpf_object__open_file(file, NULL); + if (CHECK(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj))) + return; + + err = bpf_object__load(obj); + if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) + goto cleanup; + + bss_map = bpf_object__find_map_by_name(obj, "test_ns_.bss"); + if (CHECK(!bss_map, "find_bss_map", "failed\n")) + goto cleanup; + + prog = bpf_object__find_program_by_title(obj, probe_name); + if (CHECK(!prog, "find_prog", "prog '%s' not found\n", + probe_name)) + goto cleanup; + + memset(&bss, 0, sizeof(bss)); + pid_t tid = syscall(SYS_gettid); + pid_t pid = getpid(); + + id = (__u64) tid << 32 | pid; + bss.user_pid_tgid = id; + + if (CHECK_FAIL(stat("/proc/self/ns/pid", &st))) { + perror("Failed to stat /proc/self/ns/pid"); + goto cleanup; + } + + bss.dev = st.st_dev; + bss.ino = st.st_ino; + + err = bpf_map_update_elem(bpf_map__fd(bss_map), &key, &bss, 0); + if (CHECK(err, "setting_bss", "failed to set bss : %d\n", err)) + goto cleanup; + + link = bpf_program__attach_raw_tracepoint(prog, "sys_enter"); + if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n", + PTR_ERR(link))) { + link = NULL; + goto cleanup; + } + + /* trigger some syscalls */ + usleep(1); + + err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &key, &bss); + if (CHECK(err, "set_bss", "failed to get bss : %d\n", err)) + goto cleanup; + + if (CHECK(id != bss.pid_tgid, "Compare user pid/tgid vs. bpf pid/tgid", + "User pid/tgid %llu BPF pid/tgid %llu\n", id, bss.pid_tgid)) + goto cleanup; +cleanup: + if (!link) { + bpf_link__destroy(link); + link = NULL; + } + bpf_object__close(obj); +} diff --git a/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c b/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c new file mode 100644 index 0000000..1dca70a --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2019 Carlos Neira cneirabustos@gmail.com */ + +#include +#include +#include + +static volatile struct { + __u64 dev; + __u64 ino; + __u64 pid_tgid; + __u64 user_pid_tgid; +} res; + +SEC("raw_tracepoint/sys_enter") +int trace(void *ctx) +{ + __u64 ns_pid_tgid, expected_pid; + struct bpf_pidns_info nsdata; + __u32 key = 0; + + if (bpf_get_ns_current_pid_tgid(res.dev, res.ino, &nsdata, + sizeof(struct bpf_pidns_info))) + return 0; + + ns_pid_tgid = (__u64)nsdata.tgid << 32 | nsdata.pid; + expected_pid = res.user_pid_tgid; + + if (expected_pid != ns_pid_tgid) + return 0; + + res.pid_tgid = ns_pid_tgid; + + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/test_current_pid_tgid_new_ns.c b/tools/testing/selftests/bpf/test_current_pid_tgid_new_ns.c new file mode 100644 index 0000000..ed253f2 --- /dev/null +++ b/tools/testing/selftests/bpf/test_current_pid_tgid_new_ns.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Carlos Neira cneirabustos@gmail.com */ +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include "test_progs.h" + +#define CHECK_NEWNS(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; \ +}) + +struct bss { + __u64 dev; + __u64 ino; + __u64 pid_tgid; + __u64 user_pid_tgid; +}; + +int main(int argc, char **argv) +{ + pid_t pid; + int exit_code = 1; + struct stat st; + + printf("Testing bpf_get_ns_current_pid_tgid helper in new ns\n"); + + if (stat("/proc/self/ns/pid", &st)) { + perror("stat failed on /proc/self/ns/pid ns\n"); + printf("%s:FAILED\n", argv[0]); + return exit_code; + } + + if (CHECK_NEWNS(unshare(CLONE_NEWPID | CLONE_NEWNS), + "unshare CLONE_NEWPID | CLONE_NEWNS", "error errno=%d\n", errno)) + return exit_code; + + pid = fork(); + if (pid == -1) { + perror("Fork() failed\n"); + printf("%s:FAILED\n", argv[0]); + return exit_code; + } + + if (pid > 0) { + int status; + + usleep(5); + waitpid(pid, &status, 0); + return 0; + } else { + + pid = fork(); + if (pid == -1) { + perror("Fork() failed\n"); + printf("%s:FAILED\n", argv[0]); + return exit_code; + } + + if (pid > 0) { + int status; + waitpid(pid, &status, 0); + return 0; + } else { + if (CHECK_NEWNS(mount("none", "/proc", NULL, MS_PRIVATE|MS_REC, NULL), + "Unmounting proc", "Cannot umount proc! errno=%d\n", errno)) + return exit_code; + + if (CHECK_NEWNS(mount("proc", "/proc", "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL), + "Mounting proc", "Cannot mount proc! errno=%d\n", errno)) + return exit_code; + + const char *probe_name = "raw_tracepoint/sys_enter"; + const char *file = "test_ns_current_pid_tgid.o"; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_map *bss_map; + struct bpf_object *obj; + int exit_code = 1; + int err, key = 0; + struct bss bss; + struct stat st; + __u64 id; + + obj = bpf_object__open_file(file, NULL); + if (CHECK_NEWNS(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj))) + return exit_code; + + err = bpf_object__load(obj); + if (CHECK_NEWNS(err, "obj_load", "err %d errno %d\n", err, errno)) + goto cleanup; + + bss_map = bpf_object__find_map_by_name(obj, "test_ns_.bss"); + if (CHECK_NEWNS(!bss_map, "find_bss_map", "failed\n")) + goto cleanup; + + prog = bpf_object__find_program_by_title(obj, probe_name); + if (CHECK_NEWNS(!prog, "find_prog", "prog '%s' not found\n", + probe_name)) + goto cleanup; + + memset(&bss, 0, sizeof(bss)); + pid_t tid = syscall(SYS_gettid); + pid_t pid = getpid(); + + id = (__u64) tid << 32 | pid; + bss.user_pid_tgid = id; + + if (CHECK_NEWNS(stat("/proc/self/ns/pid", &st), + "stat new ns", "Failed to stat /proc/self/ns/pid errno=%d\n", errno)) + goto cleanup; + + bss.dev = st.st_dev; + bss.ino = st.st_ino; + + err = bpf_map_update_elem(bpf_map__fd(bss_map), &key, &bss, 0); + if (CHECK_NEWNS(err, "setting_bss", "failed to set bss : %d\n", err)) + goto cleanup; + + link = bpf_program__attach_raw_tracepoint(prog, "sys_enter"); + if (CHECK_NEWNS(IS_ERR(link), "attach_raw_tp", "err %ld\n", + PTR_ERR(link))) { + link = NULL; + goto cleanup; + } + + /* trigger some syscalls */ + usleep(1); + + err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &key, &bss); + if (CHECK_NEWNS(err, "set_bss", "failed to get bss : %d\n", err)) + goto cleanup; + + if (CHECK_NEWNS(id != bss.pid_tgid, "Compare user pid/tgid vs. bpf pid/tgid", + "User pid/tgid %llu BPF pid/tgid %llu\n", id, bss.pid_tgid)) + goto cleanup; + + exit_code = 0; + printf("%s:PASS\n", argv[0]); +cleanup: + if (!link) { + bpf_link__destroy(link); + link = NULL; + } + bpf_object__close(obj); + } + } +} -- 2.7.4