Date: Wed, 06 Dec 1995 14:47:40 +0100 From: Poul-Henning Kamp <phk@critter.tfs.com> To: current@freebsd.org Subject: sysctl status right now, and plea for testing. Message-ID: <379.818257660@critter.tfs.com>
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I am now in the position to actually fix the sysctl program to pick up
any sysctl variable defined in the kernel on the fly.
This means that you can add sysctl variables to your hearts content,
and they will show up in "sysctl -a" when you boot your kernel.
You don't even need to register them in the tables in <sys/sysctl.h>
(as a matter of fact: please don't!), by using the OID_AUTO as numeric
identifier in the SYSCTL_foo() macro.
In particular debug is easy now:
Stick this in your code in the kernel:
#ifdef DEBUG
#include <sys/kernel.h> /* if not already there */
#include <sys/sysctl.h> /* if not already there */
static int tweak;
SYSCTL_INT(_debug, OID_AUTO, tweak_my_driver, CTLFLAG_RW, &tweak, 0, "");
#endif
And then you can
sysctl -w debug.tweak_my_driver=7
(Please contact core@freebsd.org before adding variables outside the
_debug tree, we want to architect this a bit. Thanks).
Anyway,
The problem at hand is that sysctl now works in a systematic way, so
making it compatible with the rather haphazard output from the present
sysctl program is hard, and in my eyes, not desirable anyway.
(In particular I nuked the printing of references to other programs to
examine the variables it couldn't handle.)
I include here for your critique and comments a sysctl.c which you can
dump in usr/src/usr.sbin/sysctl and test out.
I'm considering if we should add a couple of strategic options to
sysctl, for instance:
-b
write variable value in raw binary to stdout (for dumping vnode-table
into program for instance).
-X
hexdump variables for which no rendering is known (typically structs)
-t <int>
repeat every <int> seconds
You need a kernel with the commit I made one minute ago for this to work.
If I hear no comments I will commit this in some days.
Poul-Henning
/*
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
/*static char sccsid[] = "From: @(#)sysctl.c 8.1 (Berkeley) 6/6/93"; */
static const char rcsid[] =
"$Id: sysctl.c,v 1.8 1995/11/17 16:28:42 phk Exp $";
#endif /* not lint */
#include <sys/param.h>
#include <sys/gmon.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <sys/resource.h>
#include <vm/vm_param.h>
#include <machine/cpu.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp_var.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/igmp_var.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <err.h>
int Aflag, aflag, nflag, wflag;
static int oidfmt(int *, int, char *, u_int *);
static void parse(char *);
static int show_var(int *, int);
static int sysctl_all (int *oid, int len);
static int name2oid(char *, int *);
static void
usage(void)
{
(void)fprintf(stderr, "usage:\t%s\n\t%s\n\t%s\n\t%s\n",
"sysctl [-n] variable ...", "sysctl [-n] -w variable=value ...",
"sysctl [-n] -a", "sysctl [-n] -A");
exit(1);
}
int
main(int argc, char **argv)
{
extern char *optarg;
extern int optind;
int ch;
while ((ch = getopt(argc, argv, "Aanw")) != EOF) {
switch (ch) {
case 'A':
Aflag = 1;
break;
case 'a':
aflag = 1;
break;
case 'n':
nflag = 1;
break;
case 'w':
wflag = 1;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (Aflag || aflag)
exit (sysctl_all(0,0));
if (argc == 0)
usage();
while (argc-- > 0)
parse(*argv++);
exit(0);
}
/*
* Parse a name into a MIB entry.
* Lookup and print out the MIB entry if it exists.
* Set a new value if requested.
*/
static void
parse(char *string)
{
int len;
void *newval = 0;
int intval, newsize = 0;
quad_t quadval;
int mib[CTL_MAXNAME];
char *cp, *bufp, buf[BUFSIZ];
u_int kind;
bufp = buf;
snprintf(buf, BUFSIZ, "%s", string);
if ((cp = strchr(string, '=')) != NULL) {
if (!wflag) {
fprintf(stderr, "Must specify -w to set variables\n");
exit(2);
}
*strchr(buf, '=') = '\0';
*cp++ = '\0';
while (isspace(*cp))
cp++;
newval = cp;
newsize = strlen(cp);
}
len = name2oid(bufp, mib);
if (len < 0)
errx(1, "Unknown oid '%s'", bufp);
if (oidfmt(mib,len,0,&kind))
err(1, "Couldn't find format of oid '%s'", bufp);
if (!wflag) {
if ((kind & CTLTYPE) == CTLTYPE_NODE)
sysctl_all(mib,len);
else
show_var(mib,len);
} else {
if ((kind & CTLTYPE) == CTLTYPE_NODE)
errx(1, "oid '%s' isn't a leaf node", bufp);
if (!(kind&CTLFLAG_WR))
errx(1, "oid '%s' is read only", bufp);
switch (kind & CTLTYPE) {
case CTLTYPE_INT:
intval = atoi(newval);
newval = &intval;
newsize = sizeof intval;
break;
break;
case CTLTYPE_STRING:
break;
case CTLTYPE_QUAD:
break;
sscanf(newval, "%qd", &quadval);
newval = &quadval;
newsize = sizeof quadval;
break;
default:
errx(1, "oid '%s' is type %d,"
" cannot set that", bufp);
}
printf("before:\t");
show_var(mib,len);
if (sysctl(mib, len, 0, 0, newval, newsize) == -1) {
switch (errno) {
case EOPNOTSUPP:
errx(1, "%s: value is not available\n",
string);
case ENOTDIR:
errx(1, "%s: specification is incomplete\n",
string);
case ENOMEM:
errx(1, "%s: type is unknown to this program\n",
string);
default:
perror(string);
return;
}
}
printf("after:\t");
show_var(mib,len);
}
}
/* These functions will dump out various interesting structures. */
static int
S_clockinfo(int l2,void *p)
{
struct clockinfo *ci = (struct clockinfo*)p;
if (l2 < sizeof *ci)
return 0;
printf("{ hz = %d, tick = %d, profhz = %d, stathz = %d }",
ci->hz, ci->tick, ci->profhz, ci->stathz);
return 1;
}
static int
S_loadavg(int l2,void *p)
{
struct loadavg *tv = (struct loadavg*)p;
if (l2 < sizeof *tv)
return 0;
printf("{ %.2f %.2f %.2f }",
(double)tv->ldavg[0]/(double)tv->fscale,
(double)tv->ldavg[1]/(double)tv->fscale,
(double)tv->ldavg[2]/(double)tv->fscale);
return 1;
}
static int
S_timeval(int l2,void *p)
{
struct timeval *tv = (struct timeval*)p;
char *p1,*p2;
if (l2 < sizeof *tv)
return 0;
printf("{ sec = %ld, usec = %ld } ",
tv->tv_sec, tv->tv_usec);
p1 = strdup(ctime(&tv->tv_sec));
for (p2=p1; *p2 ; p2++)
if (*p2 == '\n')
*p2 = '\0';
fputs(p1,stdout);
return 1;
}
static int
T_dev_t(int l2,void *p)
{
dev_t *d = (dev_t *)p;
if (l2 < sizeof *d)
return 0;
printf("{ major = %d, minor = %d }",
major(*d), minor(*d));
return 1;
}
/*
* These functions uses a presently undocumented interface to the kernel
* to walk the tree and get the type so it can print the value.
* This interface is under work and consideration, and should probably
* be killed with a big axe by the first person who can find the time.
* (be aware though, that the proper interface isn't as obvious as it
* may seem, there are various conflicting requirements.
*/
static int
name2oid(char *name, int *oidp)
{
int oid[2];
int i,j;
oid[0] = 0;
oid[1] = 3;
j = CTL_MAXNAME * sizeof (int);
i = sysctl(oid, 2, oidp, &j, name, strlen(name));
if (i < 0)
return i;
j /= sizeof (int);
return (j);
}
static int
oidfmt(int *oid, int len, char *fmt, u_int *kind)
{
int qoid[CTL_MAXNAME+2];
u_char buf[BUFSIZ];
int i,j;
qoid[0] = 0;
qoid[1] = 4;
memcpy(qoid + 2, oid, len * sizeof(int));
j = sizeof buf;
i = sysctl(qoid, len + 2, buf, &j, 0, 0);
if (i)
err(-1,"sysctl fmt %d %d %d",i,j,errno);
if (kind)
*kind = *(u_int *)buf;
if (fmt)
strcpy(fmt,(char *)(buf + sizeof(u_int)));
return 0;
}
static int
show_var(int *oid, int len)
{
u_char buf[BUFSIZ], val[BUFSIZ*100], *p;
char name[BUFSIZ], *fmt;
int qoid[CTL_MAXNAME+2];
int i, j;
u_int kind;
qoid[0] = 0;
qoid[1] = 4;
memcpy(qoid + 2, oid, len * sizeof(int));
j = sizeof buf;
i = sysctl(qoid, len + 2, buf, &j, 0, 0);
if (i)
err(-1,"sysctl fmt %d %d %d",i,j,errno);
kind = *(u_int *)buf;
fmt = (char *)(buf + sizeof(u_int));
qoid[1] = 1;
j = sizeof name;
i = sysctl(qoid, len + 2, name, &j, 0, 0);
if (i)
return (0);
j = sizeof val;
i = sysctl(oid, len, val, &j, 0, 0);
if (i || !j)
return (0);
p = val;
switch (*fmt) {
case 'A':
if (!nflag)
printf("%s = ", name);
printf("%s\n", p);
break;
case 'I':
if (!nflag)
printf("%s = ", name);
printf("%d\n", *(int *)p);
break;
case 'T':
case 'S':
{
int (*func)(int, void *) = 0;
i = 0;
if (!strcmp(fmt, "S,clockinfo")) func = S_clockinfo;
else if (!strcmp(fmt, "S,timeval")) func = S_timeval;
else if (!strcmp(fmt, "S,loadavg")) func = S_loadavg;
else if (!strcmp(fmt, "T,dev_t")) func = T_dev_t;
if (func) {
if (!nflag)
printf("%s = ", name);
i = (*func)(j, p);
}
if (i) {
printf("\n");
break;
}
}
default:
if (!Aflag)
break;
if (!nflag)
printf("%s = ",name);
printf("Format:%s Length:%d Dump:0x", fmt, j);
while (j--) {
printf("%02x",*p++);
if (p < val+16)
continue;
printf("...");
break;
}
printf("\n");
break;
}
return (0);
}
static int
sysctl_all (int *oid, int len)
{
int name1[22],name2[22];
int i,j, l1,l2;
name1[0] = 0;
name1[1] = 2;
l1 = 2;
if (len) {
memcpy(name1+2, oid, len*sizeof (int));
l1 += len;
} else {
name1[2] = 1;
l1++;
}
while (1) {
l2 = sizeof name2;
j = sysctl(name1,l1,name2,&l2,0,0);
if (j < 0)
if (errno == ENOENT)
return 0;
else
err(-1,"sysctl(getnext) %d %d",j,l2);
l2 /= sizeof (int);
if (l2 < len)
return 0;
for (i = 0; i < len; i++)
if (name2[i] != oid[i])
return 0;
i = show_var(name2, l2);
if (i)
return i;
memcpy(name1+2, name2, l2*sizeof (int));
l1 = 2 + l2;
}
}
--
Poul-Henning Kamp | phk@FreeBSD.ORG FreeBSD Core-team.
http://www.freebsd.org/~phk | phk@login.dknet.dk Private mailbox.
whois: [PHK] | phk@ref.tfs.com TRW Financial Systems, Inc.
Just that: dried leaves in boiling water ?
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