Date: 09 Jan 1999 12:05:20 +0100 From: Dag-Erling Smorgrav <des@flood.ping.uio.no> To: committers@FreeBSD.ORG Subject: sysctl descriptions Message-ID: <86u2y0btan.fsf@niobe.ewox.org>
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The attached patches implement a mechanism for retrieving a sysctl's
description. I haven't tested the patches yet, but they compile
cleanly against a fairly recent (couple of hours old) -current.
There are four patches in this patchkit: two for the kernel (sysctl.h
and kern_sysctl.c) and two for userland (sysctl.c and sysctl.8). The
changes are:
sysctl.h: bring the description into the sysctl structure (it was
previously ignored)
kern_sysctl.c: add sysctl_sysctl_descr, which returns the description
of a given sysctl. Register it as sysctl 0.5.
sysctl.c: some cleanup (usage() and option handling), add a -d option
which makes sysctl(8) display the description instead of the value.
sysctl.8: document it.
So what do you think? Go or no go?
OBTW, while I'm at it I'm game to redesign the meta-sysctl API if
you'll let me :) I won't mind too much if somebody tells me what those
"conflicting requirements" are so I don't jump in and repeat an old
mistake instead of making up my own.
DES
--
Dag-Erling Smørgrav - des@flood.ping.uio.no
Index: sys/sys/sysctl.h
===================================================================
RCS file: /home/ncvs/src/sys/sys/sysctl.h,v
retrieving revision 1.68
diff -u -r1.68 sysctl.h
--- sysctl.h 1998/12/27 18:03:29 1.68
+++ sysctl.h 1999/01/09 09:59:06
@@ -122,6 +122,7 @@
const char *oid_name;
int (*oid_handler) SYSCTL_HANDLER_ARGS;
const char *oid_fmt;
+ const char *oid_descr;
};
#define SYSCTL_IN(r, p, l) (r->newfunc)(r, p, l)
@@ -136,7 +137,7 @@
/* This constructs a "raw" MIB oid. */
#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 }; \
+ nbr, kind, a1, a2, #name, handler, fmt, descr }; \
DATA_SET(sysctl_##parent, sysctl__##parent##_##name)
/* This constructs a node from which other oids can hang. */
Index: sys/kern/kern_sysctl.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/kern_sysctl.c,v
retrieving revision 1.81
diff -u -r1.81 kern_sysctl.c
--- kern_sysctl.c 1998/12/27 18:03:29 1.81
+++ kern_sysctl.c 1999/01/09 10:49:48
@@ -155,9 +155,10 @@
*
* {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
@@ -491,6 +492,47 @@
SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, "");
+
+static int
+sysctl_sysctl_descr SYSCTL_HANDLER_ARGS
+{
+ 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);
+}
+
+SYSCTL_NODE(_sysctl, 5, descr, CTLFLAG_RD, sysctl_sysctl_descr, "");
/*
* Default "handler" functions.
Index: sysctl/sysctl.c
===================================================================
RCS file: /home/ncvs/src/usr.sbin/sysctl/sysctl.c,v
retrieving revision 1.19
diff -u -r1.19 sysctl.c
--- sysctl.c 1998/11/08 19:27:43 1.19
+++ sysctl.c 1999/01/09 10:22:21
@@ -58,7 +58,7 @@
#include <string.h>
#include <unistd.h>
-static int Aflag, aflag, nflag, wflag, Xflag, bflag;
+static int Aflag, aflag, bflag, dflag, nflag, wflag, Xflag;
static int oidfmt(int *, int, char *, u_int *);
static void parse(char *);
@@ -70,11 +70,12 @@
usage(void)
{
- (void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
- "usage: sysctl [-bnX] variable ...",
- " sysctl [-bnX] -w variable=value ...",
- " sysctl [-bnX] -a",
- " sysctl [-bnX] -A");
+ (void)fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n",
+ "usage: sysctl [-bdn] variable ...",
+ " sysctl [-bn] -w variable=value ...",
+ " sysctl [-bdn] -a",
+ " sysctl [-bdn] -A",
+ " sysctl [-bdn] -X");
exit(1);
}
@@ -85,11 +86,12 @@
setbuf(stdout,0);
setbuf(stderr,0);
- while ((ch = getopt(argc, argv, "AabnwX")) != -1) {
+ while ((ch = getopt(argc, argv, "AabdnwX")) != -1) {
switch (ch) {
case 'A': Aflag = 1; break;
case 'a': aflag = 1; break;
case 'b': bflag = 1; break;
+ case 'd': dflag = 1; break;
case 'n': nflag = 1; break;
case 'w': wflag = 1; break;
case 'X': Xflag = Aflag = 1; break;
@@ -99,6 +101,8 @@
argc -= optind;
argv += optind;
+ if (wflag && (Aflag || aflag || dflag))
+ usage();
if (Aflag || aflag)
exit (sysctl_all(0, 0));
if (argc == 0)
@@ -336,7 +340,7 @@
show_var(int *oid, int nlen)
{
u_char buf[BUFSIZ], *val, *p;
- char name[BUFSIZ], *fmt;
+ char name[BUFSIZ], descr[BUFSIZ], *fmt;
int qoid[CTL_MAXNAME+2];
int i;
size_t j, len;
@@ -378,6 +382,19 @@
if (i || !j)
err(1, "sysctl name %d %d %d", i, j, errno);
+ qoid[1] = 5;
+ j = sizeof descr;
+ i = sysctl(qoid, nlen + 2, descr, &j, 0, 0);
+ if (i || !j)
+ err(1, "sysctl name %d %d %d", i, j, errno);
+
+ if (dflag) {
+ if (!nflag)
+ printf("%s: ", name);
+ printf("%s", descr[0] ? descr : "[no description]");
+ return (0);
+ }
+
p = val;
switch (*fmt) {
case 'A':
Index: sysctl/sysctl.8
===================================================================
RCS file: /home/ncvs/src/usr.sbin/sysctl/sysctl.8,v
retrieving revision 1.17
diff -u -r1.17 sysctl.8
--- sysctl.8 1998/09/29 02:01:06 1.17
+++ sysctl.8 1999/01/09 10:17:06
@@ -40,14 +40,14 @@
.Nd get or set kernel state
.Sh SYNOPSIS
.Nm sysctl
-.Op Fl bn
+.Op Fl bdn
.Ar name ...
.Nm sysctl
.Op Fl bn
.Fl w
.Ar name=value ...
.Nm sysctl
-.Op Fl bn
+.Op Fl bdn
.Fl aAX
.Sh DESCRIPTION
The
@@ -85,6 +85,9 @@
Force the value of the variable(s) to be output in raw, binary
format. No names are printed and no terminating newlines are output.
This is mostly useful with a single variable.
+.It Fl d
+Display the description rather than the value of the requested
+variable(s).
.It Fl w Ar name=value ...
Set the MIB
.Ar name
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