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/cdefs.h>
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 */
57 static void
ddb_list_scripts(const char * scriptname)58 ddb_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
65 repeat:
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 */
119 void
ddb_script(int argc,char * argv[])120 ddb_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
135 void
ddb_scripts(int argc,char * argv[]__unused)136 ddb_scripts(int argc, char *argv[] __unused)
137 {
138
139 if (argc != 1)
140 usage();
141 ddb_list_scripts(NULL);
142 }
143
144 void
ddb_unscript(int argc,char * argv[])145 ddb_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