Add kernel support for sysctl descriptions. The NO_SYSCTL_DESCRIPTIONS option

disables them if they're not wanted; in that case, sysctl_sysctl_descr will
always return an empty string.

Apporved by:	jkh

1 files changed, 48 insertions, 3 deletions

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 55e583b..26dade4 100644
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -37,7 +37,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)kern_sysctl.c	8.4 (Berkeley) 4/14/94
- * $Id: kern_sysctl.c,v 1.80 1998/12/13 07:18:54 truckman Exp $
+ * $Id: kern_sysctl.c,v 1.81 1998/12/27 18:03:29 dfr Exp $
  */
 
 #include "opt_compat.h"
@@ -155,9 +155,10 @@ sysctl_order_all(void)
  *
  * {0,0}	printf the entire MIB-tree.
  * {0,1,...}	return the name of the "..." OID.
- * {0,2,...}	return the next OID.
+ * {0,2}	return the next OID.
  * {0,3}	return the OID of the name in "new"
  * {0,4,...}	return the kind & format info for the "..." OID.
+ * {0,5,...}	return the description for the "..." OID.
  */
 
 static void
@@ -489,9 +490,53 @@ found:
 	return (error);
 }
 
-
 SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, "");
 
+static int
+sysctl_sysctl_descr SYSCTL_HANDLER_ARGS
+{
+#ifndef NO_SYSCTL_DESCRIPTIONS
+	int *name = (int *) arg1;
+	u_int namelen = arg2;
+	int i, j, error = 0;
+	struct sysctl_oid **oidpp;
+	struct linker_set *lsp = &sysctl_;
+
+	if (!lsp || !namelen)
+		return (SYSCTL_OUT(req, "", 1));
+	
+	while (namelen) {
+		oidpp = (struct sysctl_oid **) lsp->ls_items;
+		j = lsp->ls_length;
+		lsp = 0;
+		for (i = 0; i < j; i++, oidpp++) {
+			if (*oidpp && ((*oidpp)->oid_number != *name))
+				continue;
+
+			namelen--;
+			name++;
+
+			if (((*oidpp)->oid_kind & CTLTYPE) != CTLTYPE_NODE)
+				break;
+
+			if ((*oidpp)->oid_handler)
+				break;
+
+			lsp = (struct linker_set*)(*oidpp)->oid_arg1;
+			break;
+		}
+	}
+	
+	error = SYSCTL_OUT(req, (*oidpp)->oid_descr,
+			   strlen((*oidpp)->oid_descr) + 1);
+	return (error);
+#else
+	return (SYSCTL_OUT(req, "", 1));
+#endif /* !NO_SYSCTL_DESCRIPTIONS */
+}
+
+SYSCTL_NODE(_sysctl, 5, descr, CTLFLAG_RD, sysctl_sysctl_descr, "");
+
 /*
  * Default "handler" functions.
  */