/* Test of link() function. Copyright (C) 2009-2018 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ /* This file is designed to test both link(a,b) and linkat(AT_FDCWD,a,AT_FDCWD,b,0). FUNC is the function to test. Assumes that BASE and ASSERT are already defined, and that appropriate headers are already included. If PRINT, warn before skipping tests with status 77. This test does not try to create hard links to symlinks, but does test other aspects of symlink. */ static int test_link (int (*func) (char const *, char const *), bool print) { int fd; int ret; /* Create first file. */ fd = open (BASE "a", O_CREAT | O_EXCL | O_WRONLY, 0600); ASSERT (0 <= fd); ASSERT (write (fd, "hello", 5) == 5); ASSERT (close (fd) == 0); /* Not all file systems support link. Mingw doesn't have reliable st_nlink on hard links, but our implementation does fail with EPERM on poor file systems, and we can detect the inferior stat() via st_ino. Cygwin 1.5.x copies rather than links files on those file systems, but there, st_nlink and st_ino are reliable. */ ret = func (BASE "a", BASE "b"); if (!ret) { struct stat st; ASSERT (stat (BASE "b", &st) == 0); if (st.st_ino && st.st_nlink != 2) { ASSERT (unlink (BASE "b") == 0); errno = EPERM; ret = -1; } } if (ret == -1) { /* If the device does not support hard links, errno is EPERM on Linux, EOPNOTSUPP on FreeBSD. */ switch (errno) { case EPERM: case EOPNOTSUPP: if (print) fputs ("skipping test: " "hard links not supported on this file system\n", stderr); ASSERT (unlink (BASE "a") == 0); return 77; default: perror ("link"); return 1; } } ASSERT (ret == 0); /* Now, for some behavior tests. Modify the contents of 'b', and ensure that 'a' can see it, both while 'b' exists and after. */ fd = open (BASE "b", O_APPEND | O_WRONLY); ASSERT (0 <= fd); ASSERT (write (fd, "world", 5) == 5); ASSERT (close (fd) == 0); { char buf[11] = { 0 }; fd = open (BASE "a", O_RDONLY); ASSERT (0 <= fd); ASSERT (read (fd, buf, 10) == 10); ASSERT (strcmp (buf, "helloworld") == 0); ASSERT (close (fd) == 0); ASSERT (unlink (BASE "b") == 0); fd = open (BASE "a", O_RDONLY); ASSERT (0 <= fd); ASSERT (read (fd, buf, 10) == 10); ASSERT (strcmp (buf, "helloworld") == 0); ASSERT (close (fd) == 0); } /* Test for various error conditions. */ ASSERT (mkdir (BASE "d", 0700) == 0); errno = 0; ASSERT (func (BASE "a", ".") == -1); ASSERT (errno == EEXIST || errno == EINVAL); errno = 0; ASSERT (func (BASE "a", BASE "a") == -1); ASSERT (errno == EEXIST); ASSERT (func (BASE "a", BASE "b") == 0); errno = 0; ASSERT (func (BASE "a", BASE "b") == -1); ASSERT (errno == EEXIST); errno = 0; ASSERT (func (BASE "a", BASE "d") == -1); ASSERT (errno == EEXIST); errno = 0; ASSERT (func (BASE "c", BASE "e") == -1); ASSERT (errno == ENOENT); errno = 0; ASSERT (func (BASE "a", BASE "c/.") == -1); ASSERT (errno == ENOENT); errno = 0; ASSERT (func (BASE "a/", BASE "c") == -1); ASSERT (errno == ENOTDIR || errno == EINVAL); errno = 0; ASSERT (func (BASE "a", BASE "c/") == -1); ASSERT (errno == ENOTDIR || errno == ENOENT || errno == EINVAL); /* Most platforms reject hard links to directories, and even on those that do permit it, most users can't create them. We assume that if this test is run as root and we managed to create a hard link, then unlink better be able to clean it up. */ { int result; errno = 0; result = func (BASE "d", BASE "c"); if (result == 0) { /* Probably root on Solaris. */ ASSERT (unlink (BASE "c") == 0); } else { /* Most everyone else. */ ASSERT (errno == EPERM || errno == EACCES || errno == EISDIR); errno = 0; ASSERT (func (BASE "d/.", BASE "c") == -1); ASSERT (errno == EPERM || errno == EACCES || errno == EISDIR || errno == EINVAL); errno = 0; ASSERT (func (BASE "d/.//", BASE "c") == -1); ASSERT (errno == EPERM || errno == EACCES || errno == EISDIR || errno == EINVAL); } } ASSERT (unlink (BASE "a") == 0); errno = 0; ASSERT (unlink (BASE "c") == -1); ASSERT (errno == ENOENT); ASSERT (rmdir (BASE "d") == 0); /* Test invalid use of symlink. */ if (symlink (BASE "a", BASE "link") != 0) { ASSERT (unlink (BASE "b") == 0); if (print) fputs ("skipping test: symlinks not supported on this file system\n", stderr); return 77; } errno = 0; ASSERT (func (BASE "b", BASE "link/") == -1); ASSERT (errno == ENOTDIR || errno == ENOENT || errno == EEXIST || errno == EINVAL); errno = 0; ASSERT (func (BASE "b", BASE "link") == -1); ASSERT (errno == EEXIST); ASSERT (rename (BASE "b", BASE "a") == 0); errno = 0; ASSERT (func (BASE "link/", BASE "b") == -1); ASSERT (errno == ENOTDIR || errno == EEXIST || errno == EINVAL); /* Clean up. */ ASSERT (unlink (BASE "a") == 0); ASSERT (unlink (BASE "link") == 0); return 0; }