Re: Fixing swap1_stop

["Ian D. Leroux" <idleroux%fastmail.fm@localhost>]

On Wed, 9 Aug 2017 03:38:20 -0400 christos%zoulas.com@localhost (Christos Zoulas)
wrote:
> I think it is better to modify mount to either pass a format string
> to it or to quote the pathnames so that the output is predictable.

Here's my second attempt at the latter solution (the first attempt
involved writing a utility functional called shquote which gcc
subsequently informed me was already in the standard library. oops).
It's intended to leave the output completely unchanged in all "normal"
cases, but to quote the mount point (or the device file) if either
filename contains white space or shell operators.

Example output:

$ ./mount
/dev/wd0a on / type ffs (synchronous, local)
/dev/cgd0a on /config type ffs (synchronous, local)
/dev/cgd0e on /var type ffs (log, local)
/dev/wd0f on /build type ffs (log, local)
/dev/cgd0f on /home type ffs (log, local)
kernfs on /kern type kernfs (local)
ptyfs on /dev/pts type ptyfs (local)
procfs on /proc type procfs (local)
tmpfs on /var/shm type tmpfs (nosuid, local)
tmpfs on '/home/idleroux/silly name' type tmpfs (local)

--
IDL

--- mount.c.orig        2017-08-13 15:28:55.214873672 -0400
+++ mount.c     2017-08-13 19:46:24.658887689 -0400
@@ -82,6 +82,7 @@
 static int     mountfs(const char *, const char *, const char *,
                    int, const char *, const char *, int, char *, size_t);
 static void    prmount(struct statvfs *);
+static void    quoteifneeded(const char *, char *, size_t);
 __dead static void     usage(void);


@@ -566,6 +567,22 @@
        return (0);
 }

+
+static void
+quoteifneeded(const char *name, char *buf, size_t buflen)
+{
+       const char *sp;
+       const char shops[] = " \t\n'\"&();|<>";
+
+       for (sp = name; *sp; ++sp) {
+               if (strchr(shops, *sp)) {
+                       shquote(name, buf, buflen);
+                       return;
+               }
+       }
+       strlcpy(buf, name, buflen);
+}
+
 static void
 prmount(struct statvfs *sfp)
 {
@@ -573,9 +590,14 @@
        const struct opt *o;
        struct passwd *pw;
        int f;
+       char mntfrombuf[VFS_MNAMELEN];
+       char mntonbuf[VFS_MNAMELEN];
+
+        quoteifneeded(sfp->f_mntfromname, mntfrombuf, sizeof(mntfrombuf));
+        quoteifneeded(sfp->f_mntonname, mntonbuf, sizeof(mntonbuf));

-       (void)printf("%s on %s type %.*s", sfp->f_mntfromname,
-           sfp->f_mntonname, (int)sizeof(sfp->f_fstypename),
+       (void)printf("%s on %s type %.*s", mntfrombuf, mntonbuf,
+            (int)sizeof(sfp->f_fstypename),
            sfp->f_fstypename);

        flags = sfp->f_flag & MNT_VISFLAGMASK;