1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2014 The FreeBSD Foundation
5 * All rights reserved.
6 *
7 * This software was developed by Edward Tomasz Napierala under sponsorship
8 * from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 */
32
33 /*
34 * All the "defined" stuff is for handling variables,
35 * such as ${OSNAME}, in maps.
36 */
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40
41 #include <sys/types.h>
42 #include <sys/time.h>
43 #include <sys/ioctl.h>
44 #include <sys/param.h>
45 #include <sys/linker.h>
46 #include <sys/mount.h>
47 #include <sys/socket.h>
48 #include <sys/stat.h>
49 #include <sys/wait.h>
50 #include <sys/utsname.h>
51 #include <assert.h>
52 #include <ctype.h>
53 #include <errno.h>
54 #include <fcntl.h>
55 #include <libgen.h>
56 #include <libutil.h>
57 #include <netdb.h>
58 #include <signal.h>
59 #include <stdbool.h>
60 #include <stdint.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <unistd.h>
65
66 #include "common.h"
67
68 static TAILQ_HEAD(, defined_value) defined_values;
69
70 static const char *
defined_find(const char * name)71 defined_find(const char *name)
72 {
73 struct defined_value *d;
74
75 TAILQ_FOREACH(d, &defined_values, d_next) {
76 if (strcmp(d->d_name, name) == 0)
77 return (d->d_value);
78 }
79
80 return (NULL);
81 }
82
83 char *
defined_expand(const char * string)84 defined_expand(const char *string)
85 {
86 const char *value;
87 char c, *expanded, *name;
88 int i, ret, before_len = 0, name_off = 0, name_len = 0, after_off = 0;
89 bool backslashed = false, bracketed = false;
90
91 expanded = checked_strdup(string);
92
93 for (i = 0; string[i] != '\0'; i++) {
94 c = string[i];
95 if (c == '\\' && backslashed == false) {
96 backslashed = true;
97 continue;
98 }
99 if (backslashed) {
100 backslashed = false;
101 continue;
102 }
103 backslashed = false;
104 if (c != '$')
105 continue;
106
107 /*
108 * The 'before_len' variable contains the number
109 * of characters before the '$'.
110 */
111 before_len = i;
112 assert(i + 1 < (int)strlen(string));
113 if (string[i + 1] == '{')
114 bracketed = true;
115
116 if (string[i + 1] == '\0') {
117 log_warnx("truncated variable");
118 return (NULL);
119 }
120
121 /*
122 * Skip '$'.
123 */
124 i++;
125
126 if (bracketed) {
127 if (string[i + 1] == '\0') {
128 log_warnx("truncated variable");
129 return (NULL);
130 }
131
132 /*
133 * Skip '{'.
134 */
135 i++;
136 }
137
138 /*
139 * The 'name_off' variable contains the number
140 * of characters before the variable name,
141 * including the "$" or "${".
142 */
143 name_off = i;
144
145 for (; string[i] != '\0'; i++) {
146 c = string[i];
147 /*
148 * XXX: Decide on the set of characters that can be
149 * used in a variable name.
150 */
151 if (isalnum(c) || c == '_')
152 continue;
153
154 /*
155 * End of variable name.
156 */
157 if (bracketed) {
158 if (c != '}')
159 continue;
160
161 /*
162 * The 'after_off' variable contains the number
163 * of characters before the rest of the string,
164 * i.e. after the variable name.
165 */
166 after_off = i + 1;
167 assert(i > 1);
168 assert(i - 1 > name_off);
169 name_len = i - name_off;
170 break;
171 }
172
173 after_off = i;
174 assert(i > 1);
175 assert(i > name_off);
176 name_len = i - name_off;
177 break;
178 }
179
180 name = strndup(string + name_off, name_len);
181 if (name == NULL)
182 log_err(1, "strndup");
183 value = defined_find(name);
184 if (value == NULL) {
185 log_warnx("undefined variable ${%s}", name);
186 return (NULL);
187 }
188
189 /*
190 * Concatenate it back.
191 */
192 ret = asprintf(&expanded, "%.*s%s%s",
193 before_len, string, value, string + after_off);
194 if (ret < 0)
195 log_err(1, "asprintf");
196
197 //log_debugx("\"%s\" expanded to \"%s\"", string, expanded);
198 free(name);
199
200 /*
201 * Figure out where to start searching for next variable.
202 */
203 string = expanded;
204 i = before_len + strlen(value);
205 backslashed = bracketed = false;
206 before_len = name_off = name_len = after_off = 0;
207 assert(i <= (int)strlen(string));
208 }
209
210 if (before_len != 0 || name_off != 0 || name_len != 0 || after_off != 0) {
211 log_warnx("truncated variable");
212 return (NULL);
213 }
214
215 return (expanded);
216 }
217
218 static void
defined_add(const char * name,const char * value)219 defined_add(const char *name, const char *value)
220 {
221 struct defined_value *d;
222 const char *found;
223
224 found = defined_find(name);
225 if (found != NULL)
226 log_errx(1, "variable %s already defined", name);
227
228 log_debugx("defining variable %s=%s", name, value);
229
230 d = calloc(1, sizeof(*d));
231 if (d == NULL)
232 log_err(1, "calloc");
233 d->d_name = checked_strdup(name);
234 d->d_value = checked_strdup(value);
235
236 TAILQ_INSERT_TAIL(&defined_values, d, d_next);
237 }
238
239 void
defined_parse_and_add(char * def)240 defined_parse_and_add(char *def)
241 {
242 char *name, *value;
243
244 value = def;
245 name = strsep(&value, "=");
246
247 if (value == NULL || value[0] == '\0')
248 log_errx(1, "missing variable value");
249 if (name == NULL || name[0] == '\0')
250 log_errx(1, "missing variable name");
251
252 defined_add(name, value);
253 }
254
255 void
defined_init(void)256 defined_init(void)
257 {
258 struct utsname name;
259 int error;
260
261 TAILQ_INIT(&defined_values);
262
263 error = uname(&name);
264 if (error != 0)
265 log_err(1, "uname");
266
267 defined_add("ARCH", name.machine);
268 defined_add("CPU", name.machine);
269 defined_add("HOST", name.nodename);
270 defined_add("OSNAME", name.sysname);
271 defined_add("OSREL", name.release);
272 defined_add("OSVERS", name.version);
273 }
274