github.com/kubiko/snapd@v0.0.0-20201013125620-d4f3094d9ddf/cmd/libsnap-confine-private/mount-opt.h (about)

     1  /*
     2   * Copyright (C) 2016 Canonical Ltd
     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 3 as
     6   * published by the Free Software Foundation.
     7   *
     8   * This program is distributed in the hope that it will be useful,
     9   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    10   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    11   * GNU General Public License for more details.
    12   *
    13   * You should have received a copy of the GNU General Public License
    14   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    15   *
    16   */
    17  
    18  #ifndef SNAP_CONFINE_MOUNT_OPT_H
    19  #define SNAP_CONFINE_MOUNT_OPT_H
    20  
    21  #include <stdbool.h>
    22  #include <stddef.h>
    23  
    24  /**
    25   * Convert flags for mount(2) system call to a string representation. 
    26   **/
    27  const char *sc_mount_opt2str(char *buf, size_t buf_size, unsigned long flags);
    28  
    29  /**
    30   * Compute an equivalent mount(8) command from mount(2) arguments.
    31   *
    32   * This function serves as a human-readable representation of the mount system
    33   * call. The return value is a string that looks like a shell mount command.
    34   *
    35   * Note that the returned command is may not be a valid mount command. No
    36   * sanity checking is performed on the mount flags, source or destination
    37   * arguments.
    38   *
    39   * The returned value is always buf, it is provided as a convenience.
    40   **/
    41  const char *sc_mount_cmd(char *buf, size_t buf_size, const char *source, const char
    42  			 *target, const char *fs_type, unsigned long mountflags,
    43  			 const void *data);
    44  
    45  /**
    46   * Compute an equivalent umount(8) command from umount2(2) arguments.
    47   *
    48   * This function serves as a human-readable representation of the unmount
    49   * system call. The return value is a string that looks like a shell unmount
    50   * command.
    51   *
    52   * Note that some flags are not surfaced at umount command line level. For
    53   * those flags a fake option is synthesized.
    54   *
    55   * Note that the returned command is may not be a valid umount command. No
    56   * sanity checking is performed on the mount flags, source or destination
    57   * arguments.
    58   *
    59   * The returned value is always buf, it is provided as a convenience.
    60   **/
    61  const char *sc_umount_cmd(char *buf, size_t buf_size, const char *target,
    62  			  int flags);
    63  
    64  /**
    65   * A thin wrapper around mount(2) with logging and error checks.
    66   **/
    67  void sc_do_mount(const char *source, const char *target,
    68  		 const char *fs_type, unsigned long mountflags,
    69  		 const void *data);
    70  
    71  /**
    72   * A thin wrapper around mount(2) with logging and error checks.
    73   *
    74   * This variant is allowed to silently fail when mount fails with ENOENT.
    75   * That is, it can be used to perform mount operations and if either the source
    76   * or the destination is not present, carry on as if nothing had happened.
    77   *
    78   * The return value indicates if the operation was successful or not.
    79   **/
    80  bool sc_do_optional_mount(const char *source, const char *target,
    81  			  const char *fs_type, unsigned long mountflags,
    82  			  const void *data);
    83  
    84  /**
    85   * A thin wrapper around umount(2) with logging and error checks.
    86   **/
    87  void sc_do_umount(const char *target, int flags);
    88  
    89  #endif				// SNAP_CONFINE_MOUNT_OPT_H