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freebsd/sbin/ddb/ddb_script.c
Robert Watson a1f25b0daa Add command-line tool ddb(8), which allows DDB(4) scripts to be
managed from userspace.  It is largely a wrapper for sysctl()
calls, but because the sysctls for adding and removing scripts
are awkward to use directly, this provides an easier-to-use
interface.

MFC after:	3 months
2007-12-26 09:38:22 +00:00

161 lines
4.2 KiB
C

/*-
* Copyright (c) 2007 Robert N. M. Watson
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/sysctl.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include "ddb.h"
/*
* These commands manage DDB(4) scripts from user space. For better or worse,
* the setting and unsetting of scripts is only poorly represented using
* sysctl(8), and this interface provides a more user-friendly way to
* accomplish this management, wrapped around lower-level sysctls. For
* completeness, listing of scripts is also included.
*/
#define SYSCTL_SCRIPT "debug.ddb.scripting.script"
#define SYSCTL_SCRIPTS "debug.ddb.scripting.scripts"
#define SYSCTL_UNSCRIPT "debug.ddb.scripting.unscript"
/*
* Print all scripts (scriptname==NULL) or a specific script.
*/
static void
ddb_list_scripts(const char *scriptname)
{
char *buffer, *line, *nextline;
char *line_script, *line_scriptname;
size_t buflen, len;
int ret;
repeat:
if (sysctlbyname(SYSCTL_SCRIPTS, NULL, &buflen, NULL, 0) < 0)
err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
if (buflen == 0)
return;
buffer = malloc(buflen);
if (buffer == NULL)
err(EX_OSERR, "malloc");
bzero(buffer, buflen);
len = buflen;
ret = sysctlbyname(SYSCTL_SCRIPTS, buffer, &len, NULL, 0);
if (ret < 0 && errno != ENOMEM)
err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
if (ret < 0) {
free(buffer);
goto repeat;
}
/*
* We nul'd the buffer before calling sysctl(), so at worst empty.
*
* If a specific script hasn't been requested, print it all.
*/
if (scriptname == NULL) {
printf("%s", buffer);
free(buffer);
return;
}
/*
* If a specific script has been requested, we have to parse the
* string to find it.
*/
nextline = buffer;
while ((line = strsep(&nextline, "\n")) != NULL) {
line_script = line;
line_scriptname = strsep(&line_script, "=");
if (line_script == NULL)
continue;
if (strcmp(scriptname, line_scriptname) != 0)
continue;
printf("%s\n", line_script);
break;
}
if (line == NULL) {
errno = ENOENT;
err(EX_DATAERR, "%s", scriptname);
}
free(buffer);
}
/*
* "ddb script" can be used to either print or set a script.
*/
void
ddb_script(int argc, char *argv[])
{
if (argc != 2)
usage();
argv++;
argc--;
if (strchr(argv[0], '=') != 0) {
if (sysctlbyname(SYSCTL_SCRIPT, NULL, NULL, argv[0],
strlen(argv[0]) + 1) < 0)
err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
} else
ddb_list_scripts(argv[0]);
}
void
ddb_scripts(int argc, char *argv[])
{
if (argc != 1)
usage();
ddb_list_scripts(NULL);
}
void
ddb_unscript(int argc, char *argv[])
{
int ret;
if (argc != 2)
usage();
argv++;
argc--;
ret = sysctlbyname(SYSCTL_UNSCRIPT, NULL, NULL, argv[0],
strlen(argv[0]) + 1);
if (ret < 0 && errno == EINVAL) {
errno = ENOENT;
err(EX_DATAERR, "sysctl: %s", argv[0]);
} else if (ret < 0)
err(EX_OSERR, "sysctl: %s", SYSCTL_UNSCRIPT);
}