/// <inheritdoc />
/// <exception cref="UnauthorizedAccessException">Thrown when trying to open a file/directory without having sufficient access permissions.</exception>
/// <exception cref="FileNotFoundException">Thrown when a file/directory or parts of its path cannot be found.</exception>
/// <exception cref="NativeException">Generic exception thrown when a native method fails, and the error was not covered by one of the other possible exceptions. This exception is also always included as the <see cref="Exception.InnerException"/>.</exception>
public AccessControlListEntry[] GetPermissionData(string fileName, int loadDefaultAcl, out NativePermissionDataContainer dataContainer)
{
// Ensure exclusive access to native functions
lock (_nativeFunctionsLock)
{
// Read permission data and retrieve ACL size
NativeErrorCodes err = OpenFileAndReadPermissionData(fileName, loadDefaultAcl, out dataContainer);
if (err != NativeErrorCodes.NATIVE_ERROR_SUCCESS)
{
// Throw suitable exceptions
var nativeException = RetrieveErrnoAndBuildException(nameof(OpenFileAndReadPermissionData), err, out var _, out var errnoSymbolic);
switch (err)
{
// Handle certain special exception cases
case NativeErrorCodes.NATIVE_ERROR_OPEN_FAILED when errnoSymbolic == Errno.EACCES:
throw new UnauthorizedAccessException($"Could not open \"{fileName}\" for reading.", nativeException);
case NativeErrorCodes.NATIVE_ERROR_OPEN_FAILED when errnoSymbolic == Errno.ENOENT:
throw new FileNotFoundException($"Could not open \"{fileName}\" for reading.", nativeException);
// Unhandled case, just throw generic exception directly
default:
throw nativeException;
}
}
// Read ACL
AccessControlListEntry[] acl = new AccessControlListEntry[dataContainer.AclSize];
err = ReadFileAclAndClose(acl);
if (err != NativeErrorCodes.NATIVE_ERROR_SUCCESS)
{
throw RetrieveErrnoAndBuildException(nameof(ReadFileAclAndClose), err, out var _, out var _);
}
return(acl);
}
}
/// <summary>
/// <para>Applies the contained permissions to the given file or directory.</para>
/// <para>
/// Order in ACL:
/// <list type="number">
/// <item>UserObj (owner permissions)</item>
/// <item>GroupObj (group permissions)</item>
/// <item>Other (other permissions)</item>
/// <item>User (permissions of other users)</item>
/// <item>Group (permissions of other groups)</item>
/// <item>Mask (bitwise OR of all group permissions)</item>
/// </list>
/// </para>
/// </summary>
/// <param name="fullPath">The file or directory to apply the permissions to.</param>
/// <param name="asDefault">Optional. Specifies whether to update a directory's default ACL. When using this option, the contained UNIX permissions are not applied to the file (chown/chmod), but are still assumed as consistent! This must be false for files.</param>
internal void ApplyPermissions(string fullPath, bool asDefault)
{
// Calculate ACL size first
int aclSize = 3 + _aclUserPermissions.Count + _aclGroupPermissions.Count + 1;
// Collect base permissions
NativePermissionDataContainer dataContainer = new NativePermissionDataContainer()
{
AclSize = aclSize,
// These are ignored when a directory's default ACL is set
OwnerId = OwnerId,
OwnerPermissions = OwnerPermissions,
GroupId = GroupId,
GroupPermissions = GroupPermissions,
OtherPermissions = OtherPermissions
};
// Allocate ACL
AccessControlListEntry[] aclEntries = new AccessControlListEntry[aclSize];
int pos = 0;
// Add UNIX permissions
aclEntries[pos++] = new AccessControlListEntry
{
TagType = AccessControlListEntryTagTypes.UserObj,
TagQualifier = OwnerId,
Permissions = OwnerPermissions
};
aclEntries[pos++] = new AccessControlListEntry
{
TagType = AccessControlListEntryTagTypes.GroupObj,
TagQualifier = GroupId,
Permissions = GroupPermissions
};
aclEntries[pos++] = new AccessControlListEntry
{
TagType = AccessControlListEntryTagTypes.Other,
TagQualifier = -1,
Permissions = OtherPermissions
};
// Add user and group entries
FilePermissions aclMask = GroupPermissions | OtherPermissions;
foreach (var perm in _aclUserPermissions)
{
aclMask |= perm.Value;
aclEntries[pos++] = new AccessControlListEntry
{
TagType = AccessControlListEntryTagTypes.User,
TagQualifier = perm.Key,
Permissions = perm.Value
};
}
foreach (var perm in _aclGroupPermissions)
{
aclMask |= perm.Value;
aclEntries[pos++] = new AccessControlListEntry
{
TagType = AccessControlListEntryTagTypes.Group,
TagQualifier = perm.Key,
Permissions = perm.Value
};
}
// Add mask
aclEntries[pos++] = new AccessControlListEntry
{
TagType = AccessControlListEntryTagTypes.Mask,
TagQualifier = -1,
Permissions = aclMask
};
// Apply permissions
_nativeLibraryInterface.SetPermissionData(fullPath, asDefault ? 1 : 0, ref dataContainer, aclEntries);
// TODO handle/document exceptions
}
