1// SPDX-License-Identifier: GPL-2.0
  2/* Copyright (c) 2020 Facebook */
  3#define _GNU_SOURCE
  4#include <stdio.h>
  5#include <sched.h>
  6#include <sys/mount.h>
  7#include <sys/stat.h>
  8#include <sys/types.h>
  9#include <test_progs.h>
 10
 11#define TDIR "/sys/kernel/debug"
 12
 13static int read_iter(char *file)
 14{
 15	/* 1024 should be enough to get contiguous 4 "iter" letters at some point */
 16	char buf[1024];
 17	int fd, len;
 18
 19	fd = open(file, 0);
 20	if (fd < 0)
 21		return -1;
 22	while ((len = read(fd, buf, sizeof(buf))) > 0) {
 23		buf[sizeof(buf) - 1] = '\0';
 24		if (strstr(buf, "iter")) {
 25			close(fd);
 26			return 0;
 27		}
 28	}
 29	close(fd);
 30	return -1;
 31}
 32
 33static int fn(void)
 34{
 35	struct stat a, b, c;
 36	int err, map;
 37
 38	err = unshare(CLONE_NEWNS);
 39	if (!ASSERT_OK(err, "unshare"))
 40		goto out;
 41
 42	err = mount("", "/", "", MS_REC | MS_PRIVATE, NULL);
 43	if (!ASSERT_OK(err, "mount /"))
 44		goto out;
 45
 46	err = umount(TDIR);
 47	if (!ASSERT_OK(err, "umount " TDIR))
 48		goto out;
 49
 50	err = mount("none", TDIR, "tmpfs", 0, NULL);
 51	if (!ASSERT_OK(err, "mount tmpfs"))
 52		goto out;
 53
 54	err = mkdir(TDIR "/fs1", 0777);
 55	if (!ASSERT_OK(err, "mkdir " TDIR "/fs1"))
 56		goto out;
 57	err = mkdir(TDIR "/fs2", 0777);
 58	if (!ASSERT_OK(err, "mkdir " TDIR "/fs2"))
 59		goto out;
 60
 61	err = mount("bpf", TDIR "/fs1", "bpf", 0, NULL);
 62	if (!ASSERT_OK(err, "mount bpffs " TDIR "/fs1"))
 63		goto out;
 64	err = mount("bpf", TDIR "/fs2", "bpf", 0, NULL);
 65	if (!ASSERT_OK(err, "mount bpffs " TDIR "/fs2"))
 66		goto out;
 67
 68	err = read_iter(TDIR "/fs1/maps.debug");
 69	if (!ASSERT_OK(err, "reading " TDIR "/fs1/maps.debug"))
 70		goto out;
 71	err = read_iter(TDIR "/fs2/progs.debug");
 72	if (!ASSERT_OK(err, "reading " TDIR "/fs2/progs.debug"))
 73		goto out;
 74
 75	err = mkdir(TDIR "/fs1/a", 0777);
 76	if (!ASSERT_OK(err, "creating " TDIR "/fs1/a"))
 77		goto out;
 78	err = mkdir(TDIR "/fs1/a/1", 0777);
 79	if (!ASSERT_OK(err, "creating " TDIR "/fs1/a/1"))
 80		goto out;
 81	err = mkdir(TDIR "/fs1/b", 0777);
 82	if (!ASSERT_OK(err, "creating " TDIR "/fs1/b"))
 83		goto out;
 84
 85	map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, 4, 4, 1, NULL);
 86	if (!ASSERT_GT(map, 0, "create_map(ARRAY)"))
 87		goto out;
 88	err = bpf_obj_pin(map, TDIR "/fs1/c");
 89	if (!ASSERT_OK(err, "pin map"))
 90		goto out;
 91	close(map);
 92
 93	/* Check that RENAME_EXCHANGE works for directories. */
 94	err = stat(TDIR "/fs1/a", &a);
 95	if (!ASSERT_OK(err, "stat(" TDIR "/fs1/a)"))
 96		goto out;
 97	err = renameat2(0, TDIR "/fs1/a", 0, TDIR "/fs1/b", RENAME_EXCHANGE);
 98	if (!ASSERT_OK(err, "renameat2(/fs1/a, /fs1/b, RENAME_EXCHANGE)"))
 99		goto out;
100	err = stat(TDIR "/fs1/b", &b);
101	if (!ASSERT_OK(err, "stat(" TDIR "/fs1/b)"))
102		goto out;
103	if (!ASSERT_EQ(a.st_ino, b.st_ino, "b should have a's inode"))
104		goto out;
105	err = access(TDIR "/fs1/b/1", F_OK);
106	if (!ASSERT_OK(err, "access(" TDIR "/fs1/b/1)"))
107		goto out;
108
109	/* Check that RENAME_EXCHANGE works for mixed file types. */
110	err = stat(TDIR "/fs1/c", &c);
111	if (!ASSERT_OK(err, "stat(" TDIR "/fs1/map)"))
112		goto out;
113	err = renameat2(0, TDIR "/fs1/c", 0, TDIR "/fs1/b", RENAME_EXCHANGE);
114	if (!ASSERT_OK(err, "renameat2(/fs1/c, /fs1/b, RENAME_EXCHANGE)"))
115		goto out;
116	err = stat(TDIR "/fs1/b", &b);
117	if (!ASSERT_OK(err, "stat(" TDIR "/fs1/b)"))
118		goto out;
119	if (!ASSERT_EQ(c.st_ino, b.st_ino, "b should have c's inode"))
120		goto out;
121	err = access(TDIR "/fs1/c/1", F_OK);
122	if (!ASSERT_OK(err, "access(" TDIR "/fs1/c/1)"))
123		goto out;
124
125	/* Check that RENAME_NOREPLACE works. */
126	err = renameat2(0, TDIR "/fs1/b", 0, TDIR "/fs1/a", RENAME_NOREPLACE);
127	if (!ASSERT_ERR(err, "renameat2(RENAME_NOREPLACE)")) {
128		err = -EINVAL;
129		goto out;
130	}
131	err = access(TDIR "/fs1/b", F_OK);
132	if (!ASSERT_OK(err, "access(" TDIR "/fs1/b)"))
133		goto out;
134
135out:
136	umount(TDIR "/fs1");
137	umount(TDIR "/fs2");
138	rmdir(TDIR "/fs1");
139	rmdir(TDIR "/fs2");
140	umount(TDIR);
141	exit(err);
142}
143
144void test_test_bpffs(void)
145{
146	int err, duration = 0, status = 0;
147	pid_t pid;
148
149	pid = fork();
150	if (CHECK(pid == -1, "clone", "clone failed %d", errno))
151		return;
152	if (pid == 0)
153		fn();
154	err = waitpid(pid, &status, 0);
155	if (CHECK(err == -1 && errno != ECHILD, "waitpid", "failed %d", errno))
156		return;
157	if (CHECK(WEXITSTATUS(status), "bpffs test ", "failed %d", WEXITSTATUS(status)))
158		return;
159}