1 files changed, 301 insertions, 0 deletions
diff --git a/lib/libutil/mntopts.c b/lib/libutil/mntopts.c
new file mode 100644
index 000000000000..07d3dd6d98a3
--- /dev/null
+++ b/lib/libutil/mntopts.c
@@ -0,0 +1,301 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/param.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+
+#include <err.h>
+#include <errno.h>
+#include <mntopts.h>
+#include <paths.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int getmnt_silent = 0;
+
+void
+getmntopts(const char *options, const struct mntopt *m0, int *flagp,
+	int *altflagp)
+{
+	const struct mntopt *m;
+	int negative, len;
+	char *opt, *optbuf, *p;
+	int *thisflagp;
+
+	/* Copy option string, since it is about to be torn asunder... */
+	if ((optbuf = strdup(options)) == NULL)
+		err(1, NULL);
+
+	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
+		/* Check for "no" prefix. */
+		if (opt[0] == 'n' && opt[1] == 'o') {
+			negative = 1;
+			opt += 2;
+		} else
+			negative = 0;
+
+		/*
+		 * for options with assignments in them (ie. quotas)
+		 * ignore the assignment as it's handled elsewhere
+		 */
+		p = strchr(opt, '=');
+		if (p != NULL)
+			 *++p = '\0';
+
+		/* Scan option table. */
+		for (m = m0; m->m_option != NULL; ++m) {
+			len = strlen(m->m_option);
+			if (strncasecmp(opt, m->m_option, len) == 0)
+				if (opt[len] == '\0' || opt[len] == '=')
+					break;
+		}
+
+		/* Save flag, or fail if option is not recognized. */
+		if (m->m_option) {
+			thisflagp = m->m_altloc ? altflagp : flagp;
+			if (negative == m->m_inverse)
+				*thisflagp |= m->m_flag;
+			else
+				*thisflagp &= ~m->m_flag;
+		} else if (!getmnt_silent) {
+			errx(1, "-o %s: option not supported", opt);
+		}
+	}
+
+	free(optbuf);
+}
+
+void
+rmslashes(char *rrpin, char *rrpout)
+{
+	char *rrpoutstart;
+
+	*rrpout = *rrpin;
+	for (rrpoutstart = rrpout; *rrpin != '\0'; *rrpout++ = *rrpin++) {
+
+		/* skip all double slashes */
+		while (*rrpin == '/' && *(rrpin + 1) == '/')
+			 rrpin++;
+	}
+
+	/* remove trailing slash if necessary */
+	if (rrpout - rrpoutstart > 1 && *(rrpout - 1) == '/')
+		*(rrpout - 1) = '\0';
+	else
+		*rrpout = '\0';
+}
+
+int
+checkpath(const char *path, char *resolved)
+{
+	struct stat sb;
+
+	if (realpath(path, resolved) == NULL || stat(resolved, &sb) != 0)
+		return (1);
+	if (!S_ISDIR(sb.st_mode)) {
+		errno = ENOTDIR;
+		return (1);
+	}
+	return (0);
+}
+
+int
+checkpath_allow_file(const char *path, char *resolved)
+{
+	struct stat sb;
+
+	if (realpath(path, resolved) == NULL || stat(resolved, &sb) != 0)
+		return (1);
+	if (!S_ISDIR(sb.st_mode) && !S_ISREG(sb.st_mode)) {
+		errno = ENOTDIR;
+		return (1);
+	}
+	return (0);
+}
+
+/*
+ * Get the mount point information for name. Name may be mount point name
+ * or device name (with or without /dev/ preprended).
+ */
+struct statfs *
+getmntpoint(const char *name)
+{
+	struct stat devstat, mntdevstat;
+	char device[sizeof(_PATH_DEV) - 1 + MNAMELEN];
+	char *ddevname;
+	struct statfs *mntbuf, *statfsp;
+	int i, mntsize, isdev;
+	u_long len;
+
+	if (stat(name, &devstat) != 0)
+		return (NULL);
+	if (S_ISCHR(devstat.st_mode) || S_ISBLK(devstat.st_mode))
+		isdev = 1;
+	else
+		isdev = 0;
+	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
+	for (i = 0; i < mntsize; i++) {
+		statfsp = &mntbuf[i];
+		if (isdev == 0) {
+			if (strcmp(name, statfsp->f_mntonname))
+				continue;
+			return (statfsp);
+		}
+		ddevname = statfsp->f_mntfromname;
+		if (*ddevname != '/') {
+			if ((len = strlen(_PATH_DEV) + strlen(ddevname) + 1) >
+			    sizeof(statfsp->f_mntfromname) ||
+			    len > sizeof(device))
+				continue;
+			strncpy(device, _PATH_DEV, len);
+			strncat(device, ddevname, len);
+			if (stat(device, &mntdevstat) == 0)
+				strncpy(statfsp->f_mntfromname, device, len);
+		}
+		if (stat(ddevname, &mntdevstat) == 0 &&
+		    S_ISCHR(mntdevstat.st_mode) &&
+		    mntdevstat.st_rdev == devstat.st_rdev)
+			return (statfsp);
+	}
+	return (NULL);
+}
+
+/*
+ * If possible reload a mounted filesystem.
+ * When prtmsg != NULL print a warning if a reload is attempted, but fails.
+ * Return 0 on success, 1 on failure.
+ */
+int
+chkdoreload(struct statfs *mntp,
+	void (*prtmsg)(const char *, ...) __printflike(1,2))
+{
+	struct iovec *iov;
+	int iovlen, error;
+	char errmsg[255];
+
+	/*
+	 * If the filesystem is not mounted it does not need to be reloaded.
+	 * If it is mounted for writing, then it could not have been opened
+	 * for writing by a utility, so does not need to be reloaded.
+	 */
+	if (mntp == NULL || (mntp->f_flags & MNT_RDONLY) == 0)
+		return (0);
+
+	/*
+	 * We modified a mounted file system.  Do a mount update on
+	 * it so we can continue using it as safely as possible.
+	 */
+	iov = NULL;
+	iovlen = 0;
+	errmsg[0] = '\0';
+	build_iovec(&iov, &iovlen, "fstype", __DECONST(void *, "ffs"), 4);
+	build_iovec(&iov, &iovlen, "from", mntp->f_mntfromname, (size_t)-1);
+	build_iovec(&iov, &iovlen, "fspath", mntp->f_mntonname, (size_t)-1);
+	build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));
+	build_iovec(&iov, &iovlen, "update", NULL, 0);
+	build_iovec(&iov, &iovlen, "reload", NULL, 0);
+	/*
+	 * XX: We need the following line until we clean up
+	 * nmount parsing of root mounts and NFS root mounts.
+	 */
+	build_iovec(&iov, &iovlen, "ro", NULL, 0);
+	error = nmount(iov, iovlen, mntp->f_flags);
+	free_iovec(&iov, &iovlen);
+	if (error == 0)
+		return (0);
+	if (prtmsg != NULL)
+		prtmsg("mount reload of '%s' failed: %s %s\n\n",
+		    mntp->f_mntonname, strerror(errno), errmsg);
+	return (1);
+}
+
+void
+build_iovec(struct iovec **iov, int *iovlen, const char *name, void *val,
+	    size_t len)
+{
+	int i;
+
+	if (*iovlen < 0)
+		return;
+	i = *iovlen;
+	*iov = realloc(*iov, sizeof **iov * (i + 2));
+	if (*iov == NULL) {
+		*iovlen = -1;
+		return;
+	}
+	(*iov)[i].iov_base = strdup(name);
+	(*iov)[i].iov_len = strlen(name) + 1;
+	i++;
+	(*iov)[i].iov_base = val;
+	if (len == (size_t)-1) {
+		if (val != NULL)
+			len = strlen(val) + 1;
+		else
+			len = 0;
+	}
+	(*iov)[i].iov_len = (int)len;
+	*iovlen = ++i;
+}
+
+/*
+ * This function is needed for compatibility with parameters
+ * which used to use the mount_argf() command for the old mount() syscall.
+ */
+void
+build_iovec_argf(struct iovec **iov, int *iovlen, const char *name,
+    const char *fmt, ...)
+{
+	va_list ap;
+	char val[255] = { 0 };
+
+	va_start(ap, fmt);
+	vsnprintf(val, sizeof(val), fmt, ap);
+	va_end(ap);
+	build_iovec(iov, iovlen, name, strdup(val), (size_t)-1);
+}
+
+/*
+ * Free the iovec and reset to NULL with zero length.  Useful for calling
+ * nmount in a loop.
+ */
+void
+free_iovec(struct iovec **iov, int *iovlen)
+{
+	int i;
+
+	for (i = 0; i < *iovlen; i += 2)
+		free((*iov)[i].iov_base);
+	free(*iov);
+}