| 1 | /* |
| 2 | * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: LGPL-2.1-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #ifndef _COMPAT_DIRECTORY_HANDLE_H |
| 9 | #define _COMPAT_DIRECTORY_HANDLE_H |
| 10 | |
| 11 | #include <common/credentials.hpp> |
| 12 | #include <common/macros.hpp> |
| 13 | |
| 14 | #include <sys/stat.h> |
| 15 | #include <urcu/ref.h> |
| 16 | |
| 17 | enum lttng_directory_handle_rmdir_recursive_flags { |
| 18 | LTTNG_DIRECTORY_HANDLE_FAIL_NON_EMPTY_FLAG = (1U << 0), |
| 19 | LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG = (1U << 1), |
| 20 | }; |
| 21 | |
| 22 | /* |
| 23 | * Some platforms, such as Solaris 10, do not support directory file descriptors |
| 24 | * and their associated functions (*at(...)), which are defined in POSIX.2008. |
| 25 | * |
| 26 | * This wrapper provides a handle that is either a copy of a directory's path |
| 27 | * or a directory file descriptors, depending on the platform's capabilities. |
| 28 | */ |
| 29 | #ifdef HAVE_DIRFD |
| 30 | |
| 31 | struct lttng_directory_handle; |
| 32 | |
| 33 | using lttng_directory_handle_destroy_cb = void (*)(struct lttng_directory_handle *, void *); |
| 34 | |
| 35 | struct lttng_directory_handle { |
| 36 | struct urcu_ref ref; |
| 37 | ino_t directory_inode; |
| 38 | int dirfd; |
| 39 | lttng_directory_handle_destroy_cb destroy_cb; |
| 40 | void *destroy_cb_data; |
| 41 | }; |
| 42 | |
| 43 | static inline int lttng_directory_handle_get_dirfd(const struct lttng_directory_handle *handle) |
| 44 | { |
| 45 | return handle->dirfd; |
| 46 | } |
| 47 | |
| 48 | #else |
| 49 | struct lttng_directory_handle { |
| 50 | struct urcu_ref ref; |
| 51 | char *base_path; |
| 52 | }; |
| 53 | #endif |
| 54 | |
| 55 | /* |
| 56 | * Create a directory handle to the provided path. Passing a NULL path |
| 57 | * returns a handle to the current working directory. |
| 58 | * |
| 59 | * The reference to the directory handle must be released using |
| 60 | * lttng_directory_handle_put(). |
| 61 | */ |
| 62 | struct lttng_directory_handle *lttng_directory_handle_create(const char *path); |
| 63 | |
| 64 | /* |
| 65 | * Create a new directory handle to a path relative to an existing handle. |
| 66 | * |
| 67 | * The provided path must already exist. Note that the creation of a |
| 68 | * subdirectory and the creation of a handle are kept as separate operations |
| 69 | * to highlight the fact that there is an inherent race between the creation of |
| 70 | * a directory and the creation of a handle to it. |
| 71 | * |
| 72 | * Passing a NULL path effectively copies the original handle. |
| 73 | * |
| 74 | * The reference to the directory handle must be released using |
| 75 | * lttng_directory_handle_put(). |
| 76 | */ |
| 77 | struct lttng_directory_handle * |
| 78 | lttng_directory_handle_create_from_handle(const char *path, |
| 79 | const struct lttng_directory_handle *ref_handle); |
| 80 | |
| 81 | /* |
| 82 | * Create a new directory handle from an existing directory fd. |
| 83 | * |
| 84 | * The new directory handle assumes the ownership of the directory fd. |
| 85 | * Note that this method should only be used in very specific cases, such as |
| 86 | * re-creating a directory handle from a dirfd passed over a unix socket. |
| 87 | * |
| 88 | * The reference to the directory handle must be released using |
| 89 | * lttng_directory_handle_put(). |
| 90 | */ |
| 91 | struct lttng_directory_handle *lttng_directory_handle_create_from_dirfd(int dirfd); |
| 92 | |
| 93 | /* |
| 94 | * Copy a directory handle. |
| 95 | * |
| 96 | * The reference to the directory handle must be released using |
| 97 | * lttng_directory_handle_put(). |
| 98 | */ |
| 99 | struct lttng_directory_handle * |
| 100 | lttng_directory_handle_copy(const struct lttng_directory_handle *handle); |
| 101 | |
| 102 | /* |
| 103 | * Acquire a reference to a directory handle. |
| 104 | */ |
| 105 | bool lttng_directory_handle_get(struct lttng_directory_handle *handle); |
| 106 | |
| 107 | /* |
| 108 | * Release a reference to a directory handle. |
| 109 | */ |
| 110 | void lttng_directory_handle_put(struct lttng_directory_handle *handle); |
| 111 | |
| 112 | /* |
| 113 | * Create a subdirectory relative to a directory handle. |
| 114 | */ |
| 115 | int lttng_directory_handle_create_subdirectory(const struct lttng_directory_handle *handle, |
| 116 | const char *subdirectory, |
| 117 | mode_t mode); |
| 118 | |
| 119 | /* |
| 120 | * Create a subdirectory relative to a directory handle |
| 121 | * as a given user. |
| 122 | */ |
| 123 | int lttng_directory_handle_create_subdirectory_as_user(const struct lttng_directory_handle *handle, |
| 124 | const char *subdirectory, |
| 125 | mode_t mode, |
| 126 | const struct lttng_credentials *creds); |
| 127 | |
| 128 | /* |
| 129 | * Recursively create a directory relative to a directory handle. |
| 130 | */ |
| 131 | int lttng_directory_handle_create_subdirectory_recursive( |
| 132 | const struct lttng_directory_handle *handle, const char *subdirectory_path, mode_t mode); |
| 133 | |
| 134 | /* |
| 135 | * Recursively create a directory relative to a directory handle |
| 136 | * as a given user. |
| 137 | */ |
| 138 | int lttng_directory_handle_create_subdirectory_recursive_as_user( |
| 139 | const struct lttng_directory_handle *handle, |
| 140 | const char *subdirectory_path, |
| 141 | mode_t mode, |
| 142 | const struct lttng_credentials *creds); |
| 143 | |
| 144 | /* |
| 145 | * Open a file descriptor to a path relative to a directory handle. |
| 146 | */ |
| 147 | int lttng_directory_handle_open_file(const struct lttng_directory_handle *handle, |
| 148 | const char *filename, |
| 149 | int flags, |
| 150 | mode_t mode); |
| 151 | |
| 152 | /* |
| 153 | * Open a file descriptor to a path relative to a directory handle |
| 154 | * as a given user. |
| 155 | */ |
| 156 | int lttng_directory_handle_open_file_as_user(const struct lttng_directory_handle *handle, |
| 157 | const char *filename, |
| 158 | int flags, |
| 159 | mode_t mode, |
| 160 | const struct lttng_credentials *creds); |
| 161 | |
| 162 | /* |
| 163 | * Unlink a file to a path relative to a directory handle. |
| 164 | */ |
| 165 | int lttng_directory_handle_unlink_file(const struct lttng_directory_handle *handle, |
| 166 | const char *filename); |
| 167 | |
| 168 | /* |
| 169 | * Unlink a file to a path relative to a directory handle as a given user. |
| 170 | */ |
| 171 | int lttng_directory_handle_unlink_file_as_user(const struct lttng_directory_handle *handle, |
| 172 | const char *filename, |
| 173 | const struct lttng_credentials *creds); |
| 174 | |
| 175 | /* |
| 176 | * Rename a file from a path relative to a directory handle to a new |
| 177 | * name relative to another directory handle. |
| 178 | */ |
| 179 | int lttng_directory_handle_rename(const struct lttng_directory_handle *old_handle, |
| 180 | const char *old_name, |
| 181 | const struct lttng_directory_handle *new_handle, |
| 182 | const char *new_name); |
| 183 | |
| 184 | /* |
| 185 | * Rename a file from a path relative to a directory handle to a new |
| 186 | * name relative to another directory handle as a given user. |
| 187 | */ |
| 188 | int lttng_directory_handle_rename_as_user(const struct lttng_directory_handle *old_handle, |
| 189 | const char *old_name, |
| 190 | const struct lttng_directory_handle *new_handle, |
| 191 | const char *new_name, |
| 192 | const struct lttng_credentials *creds); |
| 193 | |
| 194 | /* |
| 195 | * Remove a subdirectory relative to a directory handle. |
| 196 | */ |
| 197 | int lttng_directory_handle_remove_subdirectory(const struct lttng_directory_handle *handle, |
| 198 | const char *name); |
| 199 | |
| 200 | /* |
| 201 | * Remove a subdirectory relative to a directory handle as a given user. |
| 202 | */ |
| 203 | int lttng_directory_handle_remove_subdirectory_as_user(const struct lttng_directory_handle *handle, |
| 204 | const char *name, |
| 205 | const struct lttng_credentials *creds); |
| 206 | |
| 207 | /* |
| 208 | * Remove a subdirectory and remove its contents if it only |
| 209 | * consists in empty directories. |
| 210 | * @flags: enum lttng_directory_handle_rmdir_recursive_flags |
| 211 | */ |
| 212 | int lttng_directory_handle_remove_subdirectory_recursive( |
| 213 | const struct lttng_directory_handle *handle, const char *name, int flags); |
| 214 | |
| 215 | /* |
| 216 | * Remove a subdirectory and remove its contents if it only |
| 217 | * consists in empty directories as a given user. |
| 218 | * @flags: enum lttng_directory_handle_rmdir_recursive_flags |
| 219 | */ |
| 220 | int lttng_directory_handle_remove_subdirectory_recursive_as_user( |
| 221 | const struct lttng_directory_handle *handle, |
| 222 | const char *name, |
| 223 | const struct lttng_credentials *creds, |
| 224 | int flags); |
| 225 | |
| 226 | /* |
| 227 | * stat() a file relative to a directory handle. |
| 228 | */ |
| 229 | int lttng_directory_handle_stat(const struct lttng_directory_handle *handle, |
| 230 | const char *name, |
| 231 | struct stat *stat_buf); |
| 232 | |
| 233 | /* |
| 234 | * Returns true if this directory handle is backed by a file |
| 235 | * descriptor, false otherwise. |
| 236 | */ |
| 237 | bool lttng_directory_handle_uses_fd(const struct lttng_directory_handle *handle); |
| 238 | |
| 239 | /* |
| 240 | * Compare two directory handles. |
| 241 | * |
| 242 | * Returns true if the two directory handles are equal, false otherwise. |
| 243 | */ |
| 244 | bool lttng_directory_handle_equals(const struct lttng_directory_handle *lhs, |
| 245 | const struct lttng_directory_handle *rhs); |
| 246 | |
| 247 | #endif /* _COMPAT_PATH_HANDLE_H */ |