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("$FreeBSD$");
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 */
59 static void
ddb_list_scripts(const char * scriptname)60 ddb_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
67 repeat:
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 */
121 void
ddb_script(int argc,char * argv[])122 ddb_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
137 void
ddb_scripts(int argc,char * argv[]__unused)138 ddb_scripts(int argc, char *argv[] __unused)
139 {
140
141 if (argc != 1)
142 usage();
143 ddb_list_scripts(NULL);
144 }
145
146 void
ddb_unscript(int argc,char * argv[])147 ddb_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