1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License, Version 1.0 only
7 * (the "License"). You may not use this file except in compliance
8 * with the License.
9 *
10 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
11 * or https://opensource.org/licenses/CDDL-1.0.
12 * See the License for the specific language governing permissions
13 * and limitations under the License.
14 *
15 * When distributing Covered Code, include this CDDL HEADER in each
16 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
17 * If applicable, add the following below this CDDL HEADER, with the
18 * fields enclosed by brackets "[]" replaced with your own identifying
19 * information: Portions Copyright [yyyy] [name of copyright owner]
20 *
21 * CDDL HEADER END
22 */
23 /*
24 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
25 * Copyright 2006 Ricardo Correia. All rights reserved.
26 * Use is subject to license terms.
27 */
28
29 /* Copyright (c) 1988 AT&T */
30 /* All Rights Reserved */
31
32 #include <stdio.h>
33 #include <string.h>
34 #include <mntent.h>
35 #include <sys/errno.h>
36 #include <sys/mnttab.h>
37
38 #include <sys/types.h>
39 #include <sys/sysmacros.h>
40 #include <sys/stat.h>
41 #include <unistd.h>
42 #include <libzutil.h>
43
44 #define BUFSIZE (MNT_LINE_MAX + 2)
45
46 static __thread char buf[BUFSIZE];
47
48 #define DIFF(xx) ( \
49 (mrefp->xx != NULL) && \
50 (mgetp->xx == NULL || strcmp(mrefp->xx, mgetp->xx) != 0))
51
52 int
getmntany(FILE * fp,struct mnttab * mgetp,struct mnttab * mrefp)53 getmntany(FILE *fp, struct mnttab *mgetp, struct mnttab *mrefp)
54 {
55 int ret;
56
57 while (
58 ((ret = _sol_getmntent(fp, mgetp)) == 0) && (
59 DIFF(mnt_special) || DIFF(mnt_mountp) ||
60 DIFF(mnt_fstype) || DIFF(mnt_mntopts))) { }
61
62 return (ret);
63 }
64
65 int
_sol_getmntent(FILE * fp,struct mnttab * mgetp)66 _sol_getmntent(FILE *fp, struct mnttab *mgetp)
67 {
68 struct mntent mntbuf;
69 struct mntent *ret;
70
71 ret = getmntent_r(fp, &mntbuf, buf, BUFSIZE);
72
73 if (ret != NULL) {
74 mgetp->mnt_special = mntbuf.mnt_fsname;
75 mgetp->mnt_mountp = mntbuf.mnt_dir;
76 mgetp->mnt_fstype = mntbuf.mnt_type;
77 mgetp->mnt_mntopts = mntbuf.mnt_opts;
78 return (0);
79 }
80
81 if (feof(fp))
82 return (-1);
83
84 return (MNT_TOOLONG);
85 }
86
87 static int
getextmntent_impl(FILE * fp,struct extmnttab * mp,uint64_t * mnt_id)88 getextmntent_impl(FILE *fp, struct extmnttab *mp, uint64_t *mnt_id)
89 {
90 int ret;
91 struct stat64 st;
92
93 *mnt_id = 0;
94 ret = _sol_getmntent(fp, (struct mnttab *)mp);
95 if (ret == 0) {
96 #ifdef HAVE_STATX_MNT_ID
97 struct statx stx;
98 if (statx(AT_FDCWD, mp->mnt_mountp,
99 AT_STATX_SYNC_AS_STAT | AT_SYMLINK_NOFOLLOW,
100 STATX_MNT_ID, &stx) == 0 && (stx.stx_mask & STATX_MNT_ID))
101 *mnt_id = stx.stx_mnt_id;
102 #endif
103 if (stat64(mp->mnt_mountp, &st) != 0) {
104 mp->mnt_major = 0;
105 mp->mnt_minor = 0;
106 return (ret);
107 }
108 mp->mnt_major = major(st.st_dev);
109 mp->mnt_minor = minor(st.st_dev);
110 }
111
112 return (ret);
113 }
114
115 int
getextmntent(const char * path,struct extmnttab * entry,struct stat64 * statbuf)116 getextmntent(const char *path, struct extmnttab *entry, struct stat64 *statbuf)
117 {
118 struct stat64 st;
119 FILE *fp;
120 int match;
121 boolean_t have_mnt_id = B_FALSE;
122 uint64_t target_mnt_id = 0;
123 uint64_t entry_mnt_id;
124 #ifdef HAVE_STATX_MNT_ID
125 struct statx stx;
126 #endif
127
128 if (strlen(path) >= MAXPATHLEN) {
129 (void) fprintf(stderr, "invalid object; pathname too long\n");
130 return (-1);
131 }
132
133 /*
134 * Search for the path in /proc/self/mounts. Rather than looking for the
135 * specific path, which can be fooled by non-standard paths (i.e. ".."
136 * or "//"), we stat() the path and search for the corresponding
137 * (major,minor) device pair.
138 */
139 if (stat64(path, statbuf) != 0) {
140 (void) fprintf(stderr, "cannot open '%s': %s\n",
141 path, zfs_strerror(errno));
142 return (-1);
143 }
144
145 #ifdef HAVE_STATX_MNT_ID
146 if (statx(AT_FDCWD, path, AT_STATX_SYNC_AS_STAT | AT_SYMLINK_NOFOLLOW,
147 STATX_MNT_ID, &stx) == 0 && (stx.stx_mask & STATX_MNT_ID)) {
148 have_mnt_id = B_TRUE;
149 target_mnt_id = stx.stx_mnt_id;
150 }
151 #endif
152
153 if ((fp = fopen(MNTTAB, "re")) == NULL) {
154 (void) fprintf(stderr, "cannot open %s\n", MNTTAB);
155 return (-1);
156 }
157
158 /*
159 * Search for the given (major,minor) pair in the mount table.
160 */
161
162 match = 0;
163 while (getextmntent_impl(fp, entry, &entry_mnt_id) == 0) {
164 if (have_mnt_id) {
165 match = (entry_mnt_id == target_mnt_id);
166 } else {
167 match = makedev(entry->mnt_major, entry->mnt_minor) ==
168 statbuf->st_dev;
169 }
170 if (match)
171 break;
172 }
173 (void) fclose(fp);
174
175 if (!match) {
176 (void) fprintf(stderr, "cannot find mountpoint for '%s'\n",
177 path);
178 return (-1);
179 }
180
181 if (stat64(entry->mnt_mountp, &st) != 0) {
182 entry->mnt_major = 0;
183 entry->mnt_minor = 0;
184 return (-1);
185 }
186
187 return (0);
188 }
189