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Diffstat (limited to 'lib/libc/gen/getvfsbyname.c')
-rw-r--r--lib/libc/gen/getvfsbyname.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/lib/libc/gen/getvfsbyname.c b/lib/libc/gen/getvfsbyname.c
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index 000000000000..18cbf64b9f4a
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+++ b/lib/libc/gen/getvfsbyname.c
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+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1995
+ * 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/sysctl.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*
+ * fusefs(4) file systems may have a "subtype" which gets appended to
+ * statfs(2)'s f_fstypename field on a per-mount basis. Allow getvfsbyname to
+ * match either the full "fusefs.foobar" or the more general "fusefs".
+ */
+static bool
+are_fusefs(const char *fsname, const char *vfc_name)
+{
+ const static char fusefs[] = "fusefs";
+ const static char fusefs_dot[] = "fusefs.";
+
+ return (strncmp(fsname, fusefs_dot, sizeof(fusefs_dot) - 1) == 0 &&
+ strcmp(fusefs, vfc_name) == 0);
+}
+
+/*
+ * Given a filesystem name, determine if it is resident in the kernel,
+ * and if it is resident, return its xvfsconf structure.
+ */
+int
+getvfsbyname(const char *fsname, struct xvfsconf *vfcp)
+{
+ struct xvfsconf *xvfsp;
+ size_t buflen;
+ int cnt, i;
+
+ if (sysctlbyname("vfs.conflist", NULL, &buflen, NULL, 0) < 0)
+ return (-1);
+ xvfsp = malloc(buflen);
+ if (xvfsp == NULL)
+ return (-1);
+ if (sysctlbyname("vfs.conflist", xvfsp, &buflen, NULL, 0) < 0) {
+ free(xvfsp);
+ return (-1);
+ }
+ cnt = buflen / sizeof(struct xvfsconf);
+ for (i = 0; i < cnt; i++) {
+ if (strcmp(fsname, xvfsp[i].vfc_name) == 0 ||
+ are_fusefs(fsname, xvfsp[i].vfc_name)) {
+ memcpy(vfcp, xvfsp + i, sizeof(struct xvfsconf));
+ free(xvfsp);
+ return (0);
+ }
+ }
+ free(xvfsp);
+ errno = ENOENT;
+ return (-1);
+}