bin/165515: [jail][patch] "jail: unknown parameter: allow.nomount" when starting jail

[Jamie Gritton]

The allow.mount parameter recently changed in a subtle way - it's now
a node (to e.g. allow.mount.devfs) as well as a parameter in its own
right. This confused libjail which knows how to handle such parameters
as long as they're not boolean.

I'm including my proposed fix to libjail. This this fix, allow.nomount
should once again work, as should allow.mount and other things such as
allow.quotas/allow.noquotas should work as they did before.

- Jamie


On 02/27/12 18:21, Glen Barber wrote:
>
>> Number:         165515
>> Category:       bin
>> Synopsis:       [jail][patch] "jail: unknown parameter: allow.nomount" when starting jail
>> Confidential:   no
>> Severity:       non-critical
>> Priority:       low
>> Responsible:    freebsd-bugs
>> State:          open
>> Quarter:
>> Keywords:
>> Date-Required:
>> Class:          sw-bug
>> Submitter-Id:   current-users
>> Arrival-Date:   Tue Feb 28 01:30:07 UTC 2012
>> Closed-Date:
>> Last-Modified:
>> Originator:     Glen Barber
>> Release:        10.0-CURRENT r232116M
>> Organization:
>> Environment:
> FreeBSD nucleus 10.0-CURRENT FreeBSD 10.0-CURRENT #7 r232116M: Sun Feb 26 14:12:14 EST 2012     root at nucleus:/usr/obj/usr/src/sys/NUCLEUS  amd64
>> Description:
> On a recent -CURRENT, the jail(8) rc script fails to start jails.  This seems to be caused by looking up a sysctl that does not exist.
>> How-To-Repeat:
> Create a minimalistic jail setup as follows:
>
>   nucleus# cat /etc/rc.conf.local
>   #
>   jail_enable="YES"
>   jail_parallel_start="YES"
>   jail_list="cfm"
>   jail_cfm_hostname="cfm"
>   jail_cfm_rootdir="/jails/cfm"
>   jail_cfm_ip="172.16.1.2"
>
> Start the jail with the rc(8) script:
>
>   nucleus# sh -x /etc/rc.d/jail start cfm
>   + . /etc/rc.subr
>   [...]
>   + eval '_x="$jail_cfm_ip_multi0"'
>   + _x=''
>   + break
>   + echo ' cannot start jail "cfm": '
>    cannot start jail "cfm":
>   + tail +2 /tmp/jail.bJIDqW5x/jail.52395
>   jail: unknown parameter: allow.nomount
>
>> Fix:
> The attached patch fixes it for me.
>
>
> Patch attached with submission follows:
>
> Index: usr.sbin/jail/jail.c
> ===================================================================
> --- usr.sbin/jail/jail.c	(revision 232116)
> +++ usr.sbin/jail/jail.c	(working copy)
> @@ -84,7 +84,7 @@
>   	{ "security.jail.chflags_allowed",
>   	  "allow.nochflags", "allow.chflags" },
>   	{ "security.jail.mount_allowed",
> -	  "allow.nomount", "allow.mount" },
> +	  "allow.mount", "allow.nomount" },
>   	{ "security.jail.socket_unixiproute_only",
>   	  "allow.socket_af", "allow.nosocket_af" },
>   };
>
>
>> Release-Note:
>> Audit-Trail:
>> Unformatted:
> _______________________________________________
> freebsd-bugs at freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-bugs
> To unsubscribe, send any mail to "freebsd-bugs-unsubscribe at freebsd.org"
-------------- next part --------------
Index: lib/libjail/jail.c
===================================================================
--- lib/libjail/jail.c	(revision 232240)
+++ lib/libjail/jail.c	(working copy)
@@ -885,36 +885,20 @@
 		 * the "no" counterpart to a boolean.
 		 */
 		nname = nononame(jp->jp_name);
-		if (nname != NULL) {
-			snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", nname);
-			free(nname);
-			miblen = sizeof(mib) - 2 * sizeof(int);
-			if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
-			    strlen(desc.s)) >= 0) {
-				mib[1] = 4;
-				desclen = sizeof(desc);
-				if (sysctl(mib, (miblen / sizeof(int)) + 2,
-				    &desc, &desclen, NULL, 0) < 0) {
-					snprintf(jail_errmsg,
-					    JAIL_ERRMSGLEN,
-					    "sysctl(0.4.%s): %s", desc.s,
-					    strerror(errno));
-					return (-1);
-				}
-				if ((desc.i & CTLTYPE) == CTLTYPE_INT &&
-				    desc.s[0] == 'B') {
-					jp->jp_ctltype = desc.i;
-					jp->jp_flags |= JP_NOBOOL;
-					jp->jp_valuelen = sizeof(int);
-					return (0);
-				}
-			}
+		if (nname == NULL) {
+		unknown_parameter:
+			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
+			    "unknown parameter: %s", jp->jp_name);
+			errno = ENOENT;
+			return (-1);
 		}
-	unknown_parameter:
-		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
-		    "unknown parameter: %s", jp->jp_name);
-		errno = ENOENT;
-		return (-1);
+		snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", nname);
+		free(nname);
+		miblen = sizeof(mib) - 2 * sizeof(int);
+		if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
+		    strlen(desc.s)) < 0)
+			goto unknown_parameter;
+		jp->jp_flags |= JP_NOBOOL;
 	}
  mib_desc:
 	mib[1] = 4;
@@ -925,6 +909,16 @@
 		    "sysctl(0.4.%s): %s", jp->jp_name, strerror(errno));
 		return (-1);
 	}
+	jp->jp_ctltype = desc.i;
+	/* If this came from removing a "no", it better be a boolean. */
+	if (jp->jp_flags & JP_NOBOOL) {
+		if ((desc.i & CTLTYPE) == CTLTYPE_INT && desc.s[0] == 'B') {
+			jp->jp_valuelen = sizeof(int);
+			return (0);
+		}
+		else if ((desc.i & CTLTYPE) != CTLTYPE_NODE)
+			goto unknown_parameter;
+	}
 	/* See if this is an array type. */
 	p = strchr(desc.s, '\0');
 	isarray  = 0;
@@ -935,7 +929,6 @@
 		p[-2] = 0;
 	}
 	/* Look for types we understand. */
-	jp->jp_ctltype = desc.i;
 	switch (desc.i & CTLTYPE) {
 	case CTLTYPE_INT:
 		if (desc.s[0] == 'B')