src/common/compat/directory-handle.h

   1 /*
   2  * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #ifndef _COMPAT_DIRECTORY_HANDLE_H
  19 #define _COMPAT_DIRECTORY_HANDLE_H
  20
  21 #include <common/macros.h>
  22 #include <common/credentials.h>
  23
  24 /*
  25  * Some platforms, such as Solaris 10, do not support directory file descriptors
  26  * and their associated functions (*at(...)), which are defined in POSIX.2008.
  27  *
  28  * This wrapper provides a handle that is either a copy of a directory's path
  29  * or a directory file descriptors, depending on the platform's capabilities.
  30  */
  31 #ifdef COMPAT_DIRFD
  32 struct lttng_directory_handle {
  33         int dirfd;
  34 };
  35 #else
  36 struct lttng_directory_handle {
  37         char *base_path;
  38 };
  39 #endif
  40
  41 /*
  42  * Initialize a directory handle to the provided path. Passing a NULL path
  43  * returns a handle to the current working directory. The working directory
  44  * is not sampled; it will be accessed at the time of use of the functions
  45  * of this API.
  46  *
  47  * An initialized directory handle must be finalized using
  48  * lttng_directory_handle_fini().
  49  */
  50 LTTNG_HIDDEN
  51 int lttng_directory_handle_init(struct lttng_directory_handle *handle,
  52                 const char *path);
  53
  54 /*
  55  * Initialize a new directory handle from an existing directory fd.
  56  *
  57  * The new directory handle assumes the ownership of the directory fd.
  58  * Note that this method should only be used in very specific cases, such as
  59  * re-creating a directory handle from a dirfd passed over a unix socket.
  60  *
  61  * An initialized directory handle must be finalized using
  62  * lttng_directory_handle_fini().
  63  */
  64 LTTNG_HIDDEN
  65 int lttng_directory_handle_init_from_dirfd(
  66                 struct lttng_directory_handle *handle, int dirfd);
  67
  68 /*
  69  * Copy a directory handle.
  70  */
  71 LTTNG_HIDDEN
  72 int lttng_directory_handle_copy(const struct lttng_directory_handle *handle,
  73                 struct lttng_directory_handle *new_copy);
  74
  75 /*
  76  * Move a directory handle. The original directory handle may no longer be
  77  * used after this call. This call cannot fail; directly assign the
  78  * return value to the new directory handle.
  79  *
  80  * It is safe (but unnecessary) to call lttng_directory_handle_fini on the
  81  * original handle.
  82  */
  83 LTTNG_HIDDEN
  84 struct lttng_directory_handle
  85 lttng_directory_handle_move(struct lttng_directory_handle *original);
  86
  87 /*
  88  * Release the resources of a directory handle.
  89  */
  90 LTTNG_HIDDEN
  91 void lttng_directory_handle_fini(struct lttng_directory_handle *handle);
  92
  93 /*
  94  * Create a subdirectory relative to a directory handle.
  95  */
  96 LTTNG_HIDDEN
  97 int lttng_directory_handle_create_subdirectory(
  98                 const struct lttng_directory_handle *handle,
  99                 const char *subdirectory,
 100                 mode_t mode);
 101
 102 /*
 103  * Create a subdirectory relative to a directory handle
 104  * as a given user.
 105  */
 106 LTTNG_HIDDEN
 107 int lttng_directory_handle_create_subdirectory_as_user(
 108                 const struct lttng_directory_handle *handle,
 109                 const char *subdirectory,
 110                 mode_t mode, const struct lttng_credentials *creds);
 111
 112 /*
 113  * Recursively create a directory relative to a directory handle.
 114  */
 115 LTTNG_HIDDEN
 116 int lttng_directory_handle_create_subdirectory_recursive(
 117                 const struct lttng_directory_handle *handle,
 118                 const char *subdirectory_path,
 119                 mode_t mode);
 120
 121 /*
 122  * Recursively create a directory relative to a directory handle
 123  * as a given user.
 124  */
 125 LTTNG_HIDDEN
 126 int lttng_directory_handle_create_subdirectory_recursive_as_user(
 127                 const struct lttng_directory_handle *handle,
 128                 const char *subdirectory_path,
 129                 mode_t mode, const struct lttng_credentials *creds);
 130
 131 #endif /* _COMPAT_PATH_HANDLE_H */