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 */
56 static void
ddb_list_scripts(const char * scriptname)57 ddb_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
64 repeat:
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 */
118 void
ddb_script(int argc,char * argv[])119 ddb_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
134 void
ddb_scripts(int argc,char * argv[]__unused)135 ddb_scripts(int argc, char *argv[] __unused)
136 {
137
138 if (argc != 1)
139 usage();
140 ddb_list_scripts(NULL);
141 }
142
143 void
ddb_unscript(int argc,char * argv[])144 ddb_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