svn commit: r235624 - stable/9/lib/libjail

[Jamie Gritton]

Author: jamie
Date: Fri May 18 19:08:10 2012
New Revision: 235624
URL: http://svn.freebsd.org/changeset/base/235624

Log:
  MFC r235291:
  
   The linker isn't consistent in the ordering of dynamic sysctls, so don't
   assume that the unnamed final component of "security.jail.param.foo." is
   one less than the "foo" component.  It might be one greater instead.

Modified:
  stable/9/lib/libjail/jail.c
Directory Properties:
  stable/9/lib/libjail/   (props changed)

Modified: stable/9/lib/libjail/jail.c
==============================================================================
--- stable/9/lib/libjail/jail.c	Fri May 18 19:02:39 2012	(r235623)
+++ stable/9/lib/libjail/jail.c	Fri May 18 19:08:10 2012	(r235624)
@@ -855,7 +855,7 @@ jailparam_type(struct jailparam *jp)
 {
 	char *p, *nname;
 	size_t miblen, desclen;
-	int isarray;
+	int i, isarray;
 	struct {
 	    int i;
 	    char s[MAXPATHLEN];
@@ -977,21 +977,33 @@ jailparam_type(struct jailparam *jp)
 		}
 		break;
 	case CTLTYPE_NODE:
-		/* A node might be described by an empty-named child. */
+		/*
+		 * A node might be described by an empty-named child,
+		 * which would be immediately before or after the node itself.
+		 */
 		mib[1] = 1;
-		mib[(miblen / sizeof(int)) + 2] =
-		    mib[(miblen / sizeof(int)) + 1] - 1;
 		miblen += sizeof(int);
-		desclen = sizeof(desc.s);
-		if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s, &desclen,
-		    NULL, 0) < 0) {
-			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
-			    "sysctl(0.1): %s", strerror(errno));
-			return (-1);
+		for (i = -1; i <= 1; i += 2) {
+			mib[(miblen / sizeof(int)) + 1] =
+			    mib[(miblen / sizeof(int))] + i;
+			desclen = sizeof(desc.s);
+			if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s,
+			    &desclen, NULL, 0) < 0) {
+				if (errno == ENOENT)
+					continue;
+				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
+				    "sysctl(0.1): %s", strerror(errno));
+				return (-1);
+			}
+			if (desclen ==
+			    sizeof(SJPARAM) + strlen(jp->jp_name) + 2 &&
+			    memcmp(SJPARAM ".", desc.s, sizeof(SJPARAM)) == 0 &&
+			    memcmp(jp->jp_name, desc.s + sizeof(SJPARAM),
+			    desclen - sizeof(SJPARAM) - 2) == 0 &&
+			    desc.s[desclen - 2] == '.')
+				goto mib_desc;
 		}
-		if (desc.s[desclen - 2] != '.')
-			goto unknown_parameter;
-		goto mib_desc;
+		goto unknown_parameter;
 	default:
 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
 		    "unknown type for %s", jp->jp_name);