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

6 files changed, 73 insertions, 8 deletions

diff --git a/sys/conf/NOTES b/sys/conf/NOTES
index fbeb207..7fa3e23 100644
--- a/sys/conf/NOTES
+++ b/sys/conf/NOTES
@@ -2,7 +2,7 @@
 # LINT -- config file for checking all the sources, tries to pull in
 #	as much of the source tree as it can.
 #
-#	$Id: LINT,v 1.528 1999/01/08 17:31:07 eivind Exp $
+#	$Id: LINT,v 1.529 1999/01/09 18:12:07 wpaul Exp $
 #
 # NB: You probably don't want to try running a kernel built from this
 # file.  Instead, you should start from GENERIC, and add options from
@@ -772,6 +772,9 @@ options 	VINUMDEBUG	#enable Vinum debugging hooks
 # Size of the kernel message buffer.  Should be N * pagesize.
 options		"MSGBUF_SIZE=40960"
 
+# Conserve space by not including sysctl descriptions (see sysctl(8))
+#options	NO_SYSCTL_DESCRIPTIONS
+
 
 #####################################################################
 # HARDWARE DEVICE CONFIGURATION
diff --git a/sys/conf/options b/sys/conf/options
index 8e593d9..d401ef8 100644
--- a/sys/conf/options
+++ b/sys/conf/options
@@ -1,4 +1,4 @@
-#	$Id: options,v 1.113 1998/12/28 16:31:26 peter Exp $
+#	$Id: options,v 1.114 1999/01/08 17:31:05 eivind Exp $
 #
 #        On the handling of kernel options   
 # 
@@ -254,6 +254,7 @@ DIAGNOSTIC		opt_global.h
 ENABLE_VFS_IOOPT	opt_global.h
 INVARIANT_SUPPORT	opt_global.h
 INVARIANTS		opt_global.h
+NO_SYSCTL_DESCRIPTIONS	opt_global.h
 SIMPLELOCK_DEBUG	opt_global.h
 VFS_BIO_DEBUG		opt_global.h
 
diff --git a/sys/i386/conf/LINT b/sys/i386/conf/LINT
index fbeb207..7fa3e23 100644
--- a/sys/i386/conf/LINT
+++ b/sys/i386/conf/LINT
@@ -2,7 +2,7 @@
 # LINT -- config file for checking all the sources, tries to pull in
 #	as much of the source tree as it can.
 #
-#	$Id: LINT,v 1.528 1999/01/08 17:31:07 eivind Exp $
+#	$Id: LINT,v 1.529 1999/01/09 18:12:07 wpaul Exp $
 #
 # NB: You probably don't want to try running a kernel built from this
 # file.  Instead, you should start from GENERIC, and add options from
@@ -772,6 +772,9 @@ options 	VINUMDEBUG	#enable Vinum debugging hooks
 # Size of the kernel message buffer.  Should be N * pagesize.
 options		"MSGBUF_SIZE=40960"
 
+# Conserve space by not including sysctl descriptions (see sysctl(8))
+#options	NO_SYSCTL_DESCRIPTIONS
+
 
 #####################################################################
 # HARDWARE DEVICE CONFIGURATION
diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES
index fbeb207..7fa3e23 100644
--- a/sys/i386/conf/NOTES
+++ b/sys/i386/conf/NOTES
@@ -2,7 +2,7 @@
 # LINT -- config file for checking all the sources, tries to pull in
 #	as much of the source tree as it can.
 #
-#	$Id: LINT,v 1.528 1999/01/08 17:31:07 eivind Exp $
+#	$Id: LINT,v 1.529 1999/01/09 18:12:07 wpaul Exp $
 #
 # NB: You probably don't want to try running a kernel built from this
 # file.  Instead, you should start from GENERIC, and add options from
@@ -772,6 +772,9 @@ options 	VINUMDEBUG	#enable Vinum debugging hooks
 # Size of the kernel message buffer.  Should be N * pagesize.
 options		"MSGBUF_SIZE=40960"
 
+# Conserve space by not including sysctl descriptions (see sysctl(8))
+#options	NO_SYSCTL_DESCRIPTIONS
+
 
 #####################################################################
 # HARDWARE DEVICE CONFIGURATION
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.
  */
diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h
index 4c14622..01049d0 100644
--- a/sys/sys/sysctl.h
+++ b/sys/sys/sysctl.h
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)sysctl.h	8.1 (Berkeley) 6/2/93
- * $Id: sysctl.h,v 1.67 1998/12/16 16:06:29 bde Exp $
+ * $Id: sysctl.h,v 1.68 1998/12/27 18:03:29 dfr Exp $
  */
 
 #ifndef _SYS_SYSCTL_H_
@@ -122,6 +122,9 @@ struct sysctl_oid {
 	const char	*oid_name;
 	int 		(*oid_handler) SYSCTL_HANDLER_ARGS;
 	const char	*oid_fmt;
+#ifndef NO_SYSCTL_DESCRIPTIONS
+	const char	*oid_descr;
+#endif /* !NO_SYSCTL_DESCRIPTIONS */
 };
 
 #define SYSCTL_IN(r, p, l) (r->newfunc)(r, p, l)
@@ -134,10 +137,17 @@ int sysctl_handle_string SYSCTL_HANDLER_ARGS;
 int sysctl_handle_opaque SYSCTL_HANDLER_ARGS;
 
 /* This constructs a "raw" MIB oid. */
+#ifndef NO_SYSCTL_DESCRIPTIONS
+#define SYSCTL_OID(parent, nbr, name, kind, a1, a2, handler, fmt, descr) \
+	static struct sysctl_oid sysctl__##parent##_##name = { \
+		nbr, kind, a1, a2, #name, handler, fmt, descr }; \
+	DATA_SET(sysctl_##parent, sysctl__##parent##_##name)
+#else
 #define SYSCTL_OID(parent, nbr, name, kind, a1, a2, handler, fmt, descr) \
 	static struct sysctl_oid sysctl__##parent##_##name = { \
 		nbr, kind, a1, a2, #name, handler, fmt }; \
 	DATA_SET(sysctl_##parent, sysctl__##parent##_##name)
+#endif /* !NO_SYSCTL_DESCRIPTIONS */
 
 /* This constructs a node from which other oids can hang. */
 #define SYSCTL_NODE(parent, nbr, name, access, handler, descr) \