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      1 /*
      2  * Copyright (c) 2014 Fujitsu Ltd.
      3  * Author: Xiaoguang Wang <wangxg.fnst (at) cn.fujitsu.com>
      4  *
      5  * This program is free software; you can redistribute it and/or modify it
      6  * under the terms of version 2 of the GNU General Public License as
      7  * published by the Free Software Foundation.
      8  *
      9  * This program is distributed in the hope that it would be useful, but
     10  * WITHOUT ANY WARRANTY; without even the implied warranty of
     11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
     12  *
     13  * You should have received a copy of the GNU General Public License along
     14  * with this program; if not, write the Free Software Foundation, Inc.,
     15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
     16  */
     17 
     18 /*
     19  * Description:
     20  * Verify that,
     21  *  1) mknod(2) returns -1 and sets errno to EROFS if pathname refers to
     22  *     a file on a read-only file system.
     23  *  2) mknod(2) returns -1 and sets errno to ELOOP if Too many symbolic
     24  *     links were encountered in resolving pathname.
     25  */
     26 
     27 #define _GNU_SOURCE
     28 
     29 #include <sys/types.h>
     30 #include <fcntl.h>
     31 #include <sys/stat.h>
     32 #include <stdlib.h>
     33 #include <errno.h>
     34 #include <string.h>
     35 #include <signal.h>
     36 #include <sys/mount.h>
     37 
     38 #include "test.h"
     39 #include "safe_macros.h"
     40 #include "lapi/fcntl.h"
     41 #include "mknodat.h"
     42 
     43 static void setup(void);
     44 static void cleanup(void);
     45 
     46 #define DIR_MODE	(S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP| \
     47 			 S_IXGRP|S_IROTH|S_IXOTH)
     48 #define MNT_POINT	"mntpoint"
     49 
     50 #define FIFOMODE	(S_IFIFO | S_IRUSR | S_IRGRP | S_IROTH)
     51 #define FREGMODE	(S_IFREG | S_IRUSR | S_IRGRP | S_IROTH)
     52 #define SOCKMODE	(S_IFSOCK | S_IRUSR | S_IRGRP | S_IROTH)
     53 
     54 static const char *device;
     55 static int mount_flag;
     56 
     57 static int dir_fd;
     58 static int curfd = AT_FDCWD;
     59 
     60 #define ELOPFILE	"/test_eloop"
     61 static char elooppathname[sizeof(ELOPFILE) * 43] = ".";
     62 
     63 static struct test_case_t {
     64 	int *dir_fd;
     65 	char *pathname;
     66 	mode_t mode;
     67 	int exp_errno;
     68 } test_cases[] = {
     69 	{ &curfd, "tnode1", FIFOMODE, 0 },
     70 	{ &curfd, "tnode2", FREGMODE, 0 },
     71 	{ &curfd, "tnode3", SOCKMODE, 0 },
     72 	{ &dir_fd, "tnode4", FIFOMODE, EROFS },
     73 	{ &dir_fd, "tnode5", FREGMODE, EROFS },
     74 	{ &dir_fd, "tnode6", SOCKMODE, EROFS },
     75 	{ &curfd, elooppathname, FIFOMODE, ELOOP },
     76 	{ &curfd, elooppathname, FREGMODE, ELOOP },
     77 	{ &curfd, elooppathname, SOCKMODE, ELOOP },
     78 };
     79 
     80 static void mknodat_verify(struct test_case_t *tc);
     81 
     82 char *TCID = "mknodat";
     83 int TST_TOTAL = ARRAY_SIZE(test_cases);
     84 
     85 int main(int ac, char **av)
     86 {
     87 	int lc, i;
     88 
     89 	tst_parse_opts(ac, av, NULL, NULL);
     90 
     91 	setup();
     92 
     93 	for (lc = 0; TEST_LOOPING(lc); lc++) {
     94 		tst_count = 0;
     95 
     96 		for (i = 0; i < TST_TOTAL; i++)
     97 			mknodat_verify(&test_cases[i]);
     98 	}
     99 
    100 	cleanup();
    101 	tst_exit();
    102 }
    103 
    104 static void setup(void)
    105 {
    106 	int i;
    107 	const char *fs_type;
    108 
    109 	if (tst_kvercmp(2, 6, 16) < 0) {
    110 		tst_brkm(TCONF, NULL, "This test can only run on kernels "
    111 			 "that are 2.6.16 and higher");
    112 	}
    113 
    114 	tst_require_root();
    115 
    116 	tst_sig(NOFORK, DEF_HANDLER, cleanup);
    117 
    118 	tst_tmpdir();
    119 
    120 	fs_type = tst_dev_fs_type();
    121 	device = tst_acquire_device(cleanup);
    122 
    123 	if (!device)
    124 		tst_brkm(TCONF, cleanup, "Failed to acquire device");
    125 
    126 	tst_mkfs(cleanup, device, fs_type, NULL, NULL);
    127 
    128 	TEST_PAUSE;
    129 
    130 	/*
    131 	 * mount a read-only file system for EROFS test
    132 	 */
    133 	SAFE_MKDIR(cleanup, MNT_POINT, DIR_MODE);
    134 	if (mount(device, MNT_POINT, fs_type, MS_RDONLY, NULL) < 0) {
    135 		tst_brkm(TBROK | TERRNO, cleanup,
    136 			 "mount device:%s failed", device);
    137 	}
    138 	mount_flag = 1;
    139 	dir_fd = SAFE_OPEN(cleanup, MNT_POINT, O_DIRECTORY);
    140 
    141 	/*
    142 	 * NOTE: the ELOOP test is written based on that the consecutive
    143 	 * symlinks limits in kernel is hardwired to 40.
    144 	 */
    145 	SAFE_MKDIR(cleanup, "test_eloop", DIR_MODE);
    146 	SAFE_SYMLINK(cleanup, "../test_eloop", "test_eloop/test_eloop");
    147 	for (i = 0; i < 43; i++)
    148 		strcat(elooppathname, ELOPFILE);
    149 }
    150 
    151 static void mknodat_verify(struct test_case_t *tc)
    152 {
    153 	int fd = *(tc->dir_fd);
    154 	char *pathname = tc->pathname;
    155 	mode_t mode = tc->mode;
    156 
    157 	TEST(mknodat(fd, pathname, mode, 0));
    158 
    159 	if (TEST_ERRNO == tc->exp_errno) {
    160 		tst_resm(TPASS | TTERRNO,
    161 			 "mknodat() returned the expected value");
    162 	} else {
    163 		tst_resm(TFAIL | TTERRNO,
    164 			 "mknodat() got unexpected return value; expected: "
    165 			 "%d - %s", tc->exp_errno,
    166 			 strerror(tc->exp_errno));
    167 	}
    168 
    169 	if (TEST_ERRNO == 0 &&
    170 	    ltp_syscall(__NR_unlinkat, fd, pathname, 0) < 0) {
    171 		tst_brkm(TBROK | TERRNO, cleanup, "unlinkat(%d, %s) "
    172 			 "failed.", fd, pathname);
    173 	}
    174 }
    175 
    176 static void cleanup(void)
    177 {
    178 	if (dir_fd > 0 && close(dir_fd) < 0)
    179 		tst_resm(TWARN | TERRNO, "close(%d) failed", dir_fd);
    180 	if (mount_flag && tst_umount(MNT_POINT) < 0)
    181 		tst_resm(TWARN | TERRNO, "umount device:%s failed", device);
    182 
    183 	if (device)
    184 		tst_release_device(device);
    185 
    186 	tst_rmdir();
    187 }
    188