1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2007 Robert N. M. Watson
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD: stable/11/sbin/ddb/ddb_script.c 330449 2018-03-05 07:26:05Z eadler $");
31
32#include <sys/types.h>
33#include <sys/sysctl.h>
34
35#include <err.h>
36#include <errno.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include <sysexits.h>
41
42#include "ddb.h"
43
44/*
45 * These commands manage DDB(4) scripts from user space.  For better or worse,
46 * the setting and unsetting of scripts is only poorly represented using
47 * sysctl(8), and this interface provides a more user-friendly way to
48 * accomplish this management, wrapped around lower-level sysctls.  For
49 * completeness, listing of scripts is also included.
50 */
51
52#define	SYSCTL_SCRIPT	"debug.ddb.scripting.script"
53#define	SYSCTL_SCRIPTS	"debug.ddb.scripting.scripts"
54#define	SYSCTL_UNSCRIPT	"debug.ddb.scripting.unscript"
55
56/*
57 * Print all scripts (scriptname==NULL) or a specific script.
58 */
59static void
60ddb_list_scripts(const char *scriptname)
61{
62	char *buffer, *line, *nextline;
63	char *line_script, *line_scriptname;
64	size_t buflen, len;
65	int ret;
66
67repeat:
68	if (sysctlbyname(SYSCTL_SCRIPTS, NULL, &buflen, NULL, 0) < 0)
69		err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
70	if (buflen == 0)
71		return;
72	buffer = malloc(buflen);
73	if (buffer == NULL)
74		err(EX_OSERR, "malloc");
75	bzero(buffer, buflen);
76	len = buflen;
77	ret = sysctlbyname(SYSCTL_SCRIPTS, buffer, &len, NULL, 0);
78	if (ret < 0 && errno != ENOMEM)
79		err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
80	if (ret < 0) {
81		free(buffer);
82		goto repeat;
83	}
84
85	/*
86	 * We nul'd the buffer before calling sysctl(), so at worst empty.
87	 *
88	 * If a specific script hasn't been requested, print it all.
89	 */
90	if (scriptname == NULL) {
91		printf("%s", buffer);
92		free(buffer);
93		return;
94	}
95
96	/*
97	 * If a specific script has been requested, we have to parse the
98	 * string to find it.
99	 */
100	nextline = buffer;
101	while ((line = strsep(&nextline, "\n")) != NULL) {
102		line_script = line;
103		line_scriptname = strsep(&line_script, "=");
104		if (line_script == NULL)
105			continue;
106		if (strcmp(scriptname, line_scriptname) != 0)
107			continue;
108		printf("%s\n", line_script);
109		break;
110	}
111	if (line == NULL) {
112		errno = ENOENT;
113		err(EX_DATAERR, "%s", scriptname);
114	}
115	free(buffer);
116}
117
118/*
119 * "ddb script" can be used to either print or set a script.
120 */
121void
122ddb_script(int argc, char *argv[])
123{
124
125	if (argc != 2)
126		usage();
127	argv++;
128	argc--;
129	if (strchr(argv[0], '=') != 0) {
130		if (sysctlbyname(SYSCTL_SCRIPT, NULL, NULL, argv[0],
131		    strlen(argv[0]) + 1) < 0)
132			err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
133	} else
134		ddb_list_scripts(argv[0]);
135}
136
137void
138ddb_scripts(int argc, char *argv[])
139{
140
141	if (argc != 1)
142		usage();
143	ddb_list_scripts(NULL);
144}
145
146void
147ddb_unscript(int argc, char *argv[])
148{
149	int ret;
150
151	if (argc != 2)
152		usage();
153	argv++;
154	argc--;
155	ret = sysctlbyname(SYSCTL_UNSCRIPT, NULL, NULL, argv[0],
156	    strlen(argv[0]) + 1);
157	if (ret < 0 && errno == EINVAL) {
158		errno = ENOENT;
159		err(EX_DATAERR, "sysctl: %s", argv[0]);
160	} else if (ret < 0)
161		err(EX_OSERR, "sysctl: %s", SYSCTL_UNSCRIPT);
162}
163