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