1 // SPDX-License-Identifier: GPL-2.0-or-later 2 // Copyright (c) 2024 Christian Brauner <brauner@kernel.org> 3 4 #define _GNU_SOURCE 5 #include <fcntl.h> 6 #include <linux/auto_dev-ioctl.h> 7 #include <linux/errno.h> 8 #include <sched.h> 9 #include <stdio.h> 10 #include <string.h> 11 #include <sys/stat.h> 12 #include <sys/mount.h> 13 #include <unistd.h> 14 15 #include "kselftest_harness.h" 16 17 #define MNT_NS_COUNT 11 18 #define MNT_NS_LAST_INDEX 10 19 20 struct mnt_ns_info { 21 __u32 size; 22 __u32 nr_mounts; 23 __u64 mnt_ns_id; 24 }; 25 26 #define MNT_NS_INFO_SIZE_VER0 16 /* size of first published struct */ 27 28 /* Get information about namespace. */ 29 #define NS_MNT_GET_INFO _IOR(0xb7, 10, struct mnt_ns_info) 30 /* Get next namespace. */ 31 #define NS_MNT_GET_NEXT _IOR(0xb7, 11, struct mnt_ns_info) 32 /* Get previous namespace. */ 33 #define NS_MNT_GET_PREV _IOR(0xb7, 12, struct mnt_ns_info) 34 35 FIXTURE(iterate_mount_namespaces) { 36 int fd_mnt_ns[MNT_NS_COUNT]; 37 __u64 mnt_ns_id[MNT_NS_COUNT]; 38 }; 39 40 static inline bool mntns_in_list(__u64 *mnt_ns_id, struct mnt_ns_info *info) 41 { 42 for (int i = 0; i < MNT_NS_COUNT; i++) { 43 if (mnt_ns_id[i] == info->mnt_ns_id) 44 return true; 45 } 46 return false; 47 } 48 49 FIXTURE_SETUP(iterate_mount_namespaces) 50 { 51 for (int i = 0; i < MNT_NS_COUNT; i++) 52 self->fd_mnt_ns[i] = -EBADF; 53 54 for (int i = 0; i < MNT_NS_COUNT; i++) { 55 struct mnt_ns_info info = {}; 56 57 ASSERT_EQ(unshare(CLONE_NEWNS), 0); 58 self->fd_mnt_ns[i] = open("/proc/self/ns/mnt", O_RDONLY | O_CLOEXEC); 59 ASSERT_GE(self->fd_mnt_ns[i], 0); 60 ASSERT_EQ(ioctl(self->fd_mnt_ns[i], NS_MNT_GET_INFO, &info), 0); 61 self->mnt_ns_id[i] = info.mnt_ns_id; 62 } 63 } 64 65 FIXTURE_TEARDOWN(iterate_mount_namespaces) 66 { 67 for (int i = 0; i < MNT_NS_COUNT; i++) { 68 if (self->fd_mnt_ns[i] < 0) 69 continue; 70 ASSERT_EQ(close(self->fd_mnt_ns[i]), 0); 71 } 72 } 73 74 TEST_F(iterate_mount_namespaces, iterate_all_forward) 75 { 76 int fd_mnt_ns_cur, count = 0; 77 78 fd_mnt_ns_cur = fcntl(self->fd_mnt_ns[0], F_DUPFD_CLOEXEC); 79 ASSERT_GE(fd_mnt_ns_cur, 0); 80 81 for (;;) { 82 struct mnt_ns_info info = {}; 83 int fd_mnt_ns_next; 84 85 fd_mnt_ns_next = ioctl(fd_mnt_ns_cur, NS_MNT_GET_NEXT, &info); 86 if (fd_mnt_ns_next < 0 && errno == ENOENT) 87 break; 88 if (mntns_in_list(self->mnt_ns_id, &info)) 89 count++; 90 ASSERT_GE(fd_mnt_ns_next, 0); 91 ASSERT_EQ(close(fd_mnt_ns_cur), 0); 92 fd_mnt_ns_cur = fd_mnt_ns_next; 93 } 94 ASSERT_EQ(count, MNT_NS_LAST_INDEX); 95 } 96 97 TEST_F(iterate_mount_namespaces, iterate_all_backwards) 98 { 99 int fd_mnt_ns_cur, count = 0; 100 101 fd_mnt_ns_cur = fcntl(self->fd_mnt_ns[MNT_NS_LAST_INDEX], F_DUPFD_CLOEXEC); 102 ASSERT_GE(fd_mnt_ns_cur, 0); 103 104 for (;;) { 105 struct mnt_ns_info info = {}; 106 int fd_mnt_ns_prev; 107 108 fd_mnt_ns_prev = ioctl(fd_mnt_ns_cur, NS_MNT_GET_PREV, &info); 109 if (fd_mnt_ns_prev < 0 && errno == ENOENT) 110 break; 111 if (mntns_in_list(self->mnt_ns_id, &info)) 112 count++; 113 ASSERT_GE(fd_mnt_ns_prev, 0); 114 ASSERT_EQ(close(fd_mnt_ns_cur), 0); 115 fd_mnt_ns_cur = fd_mnt_ns_prev; 116 } 117 ASSERT_EQ(count, MNT_NS_LAST_INDEX); 118 } 119 120 TEST_F(iterate_mount_namespaces, iterate_forward) 121 { 122 int fd_mnt_ns_cur; 123 124 ASSERT_EQ(setns(self->fd_mnt_ns[0], CLONE_NEWNS), 0); 125 126 fd_mnt_ns_cur = self->fd_mnt_ns[0]; 127 for (int i = 1; i < MNT_NS_COUNT; i++) { 128 struct mnt_ns_info info = {}; 129 int fd_mnt_ns_next; 130 131 fd_mnt_ns_next = ioctl(fd_mnt_ns_cur, NS_MNT_GET_NEXT, &info); 132 ASSERT_GE(fd_mnt_ns_next, 0); 133 ASSERT_EQ(close(fd_mnt_ns_cur), 0); 134 fd_mnt_ns_cur = fd_mnt_ns_next; 135 } 136 } 137 138 TEST_F(iterate_mount_namespaces, iterate_backward) 139 { 140 int fd_mnt_ns_cur; 141 142 ASSERT_EQ(setns(self->fd_mnt_ns[MNT_NS_LAST_INDEX], CLONE_NEWNS), 0); 143 144 fd_mnt_ns_cur = self->fd_mnt_ns[MNT_NS_LAST_INDEX]; 145 for (int i = MNT_NS_LAST_INDEX - 1; i >= 0; i--) { 146 struct mnt_ns_info info = {}; 147 int fd_mnt_ns_prev; 148 149 fd_mnt_ns_prev = ioctl(fd_mnt_ns_cur, NS_MNT_GET_PREV, &info); 150 ASSERT_GE(fd_mnt_ns_prev, 0); 151 ASSERT_EQ(close(fd_mnt_ns_cur), 0); 152 fd_mnt_ns_cur = fd_mnt_ns_prev; 153 } 154 } 155 156 TEST_F(iterate_mount_namespaces, nfs_valid_ioctl) 157 { 158 ASSERT_NE(ioctl(self->fd_mnt_ns[0], AUTOFS_DEV_IOCTL_OPENMOUNT, NULL), 0); 159 ASSERT_EQ(errno, ENOTTY); 160 161 ASSERT_NE(ioctl(self->fd_mnt_ns[0], AUTOFS_DEV_IOCTL_CLOSEMOUNT, NULL), 0); 162 ASSERT_EQ(errno, ENOTTY); 163 164 ASSERT_NE(ioctl(self->fd_mnt_ns[0], AUTOFS_DEV_IOCTL_READY, NULL), 0); 165 ASSERT_EQ(errno, ENOTTY); 166 } 167 168 TEST_HARNESS_MAIN 169