| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS |
| * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| * SUCH DAMAGE. |
| */ |
| |
| #include<fcntl.h> |
| #include<sys/stat.h> |
| #include<sys/types.h> |
| #include<errno.h> |
| #include<unistd.h> |
| #include<stdio.h> |
| |
| #include"private/FdPath.h" |
| |
| extern"C"int __fchmod(int,mode_t); |
| |
| int fchmod(int fd,mode_t mode){ |
| int saved_errno= errno; |
| int result= __fchmod(fd, mode); |
| if(result==0|| errno!= EBADF){ |
| return result; |
| } |
| |
| // fd could be an O_PATH file descriptor, and the kernel |
| // may not directly support fchmod() on such a file descriptor. |
| // Use /proc/self/fd instead to emulate this support. |
| // https://sourceware.org/bugzilla/show_bug.cgi?id=14578 |
| // |
| // As of February 2015, there are no kernels which support fchmod |
| // on an O_PATH file descriptor, and "man open" documents fchmod |
| // on O_PATH file descriptors as returning EBADF. |
| int fd_flag= fcntl(fd, F_GETFL); |
| if(fd_flag==-1||(fd_flag& O_PATH)==0){ |
| errno= EBADF; |
| return-1; |
| } |
| |
| errno= saved_errno; |
| result= chmod(FdPath(fd).c_str(), mode); |
| if(result==-1&& errno== ELOOP){ |
| // Linux does not support changing the mode of a symlink. |
| // For fchmodat(AT_SYMLINK_NOFOLLOW), POSIX requires a return |
| // value of ENOTSUP. Assume that's true here too. |
| errno= ENOTSUP; |
| } |
| |
| return result; |
| } |
