1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/types.h>
30#include <sys/sysctl.h>
31
32#include <err.h>
33#include <errno.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37#include <sysexits.h>
38
39#include "ddb.h"
40
41/*
42 * These commands manage DDB(4) scripts from user space.  For better or worse,
43 * the setting and unsetting of scripts is only poorly represented using
44 * sysctl(8), and this interface provides a more user-friendly way to
45 * accomplish this management, wrapped around lower-level sysctls.  For
46 * completeness, listing of scripts is also included.
47 */
48
49#define	SYSCTL_SCRIPT	"debug.ddb.scripting.script"
50#define	SYSCTL_SCRIPTS	"debug.ddb.scripting.scripts"
51#define	SYSCTL_UNSCRIPT	"debug.ddb.scripting.unscript"
52
53/*
54 * Print all scripts (scriptname==NULL) or a specific script.
55 */
56static void
57ddb_list_scripts(const char *scriptname)
58{
59	char *buffer, *line, *nextline;
60	char *line_script, *line_scriptname;
61	size_t buflen, len;
62	int ret;
63
64repeat:
65	if (sysctlbyname(SYSCTL_SCRIPTS, NULL, &buflen, NULL, 0) < 0)
66		err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
67	if (buflen == 0)
68		return;
69	buffer = malloc(buflen);
70	if (buffer == NULL)
71		err(EX_OSERR, "malloc");
72	bzero(buffer, buflen);
73	len = buflen;
74	ret = sysctlbyname(SYSCTL_SCRIPTS, buffer, &len, NULL, 0);
75	if (ret < 0 && errno != ENOMEM)
76		err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
77	if (ret < 0) {
78		free(buffer);
79		goto repeat;
80	}
81
82	/*
83	 * We nul'd the buffer before calling sysctl(), so at worst empty.
84	 *
85	 * If a specific script hasn't been requested, print it all.
86	 */
87	if (scriptname == NULL) {
88		printf("%s", buffer);
89		free(buffer);
90		return;
91	}
92
93	/*
94	 * If a specific script has been requested, we have to parse the
95	 * string to find it.
96	 */
97	nextline = buffer;
98	while ((line = strsep(&nextline, "\n")) != NULL) {
99		line_script = line;
100		line_scriptname = strsep(&line_script, "=");
101		if (line_script == NULL)
102			continue;
103		if (strcmp(scriptname, line_scriptname) != 0)
104			continue;
105		printf("%s\n", line_script);
106		break;
107	}
108	if (line == NULL) {
109		errno = ENOENT;
110		err(EX_DATAERR, "%s", scriptname);
111	}
112	free(buffer);
113}
114
115/*
116 * "ddb script" can be used to either print or set a script.
117 */
118void
119ddb_script(int argc, char *argv[])
120{
121
122	if (argc != 2)
123		usage();
124	argv++;
125	argc--;
126	if (strchr(argv[0], '=') != 0) {
127		if (sysctlbyname(SYSCTL_SCRIPT, NULL, NULL, argv[0],
128		    strlen(argv[0]) + 1) < 0)
129			err(EX_OSERR, "sysctl: %s", SYSCTL_SCRIPTS);
130	} else
131		ddb_list_scripts(argv[0]);
132}
133
134void
135ddb_scripts(int argc, char *argv[] __unused)
136{
137
138	if (argc != 1)
139		usage();
140	ddb_list_scripts(NULL);
141}
142
143void
144ddb_unscript(int argc, char *argv[])
145{
146	int ret;
147
148	if (argc != 2)
149		usage();
150	argv++;
151	argc--;
152	ret = sysctlbyname(SYSCTL_UNSCRIPT, NULL, NULL, argv[0],
153	    strlen(argv[0]) + 1);
154	if (ret < 0 && errno == EINVAL) {
155		errno = ENOENT;
156		err(EX_DATAERR, "sysctl: %s", argv[0]);
157	} else if (ret < 0)
158		err(EX_OSERR, "sysctl: %s", SYSCTL_UNSCRIPT);
159}
160