xref: /illumos-gate/usr/src/cmd/cron/parse.c (revision 8119dad84d6416f13557b0ba8e2aaf9064cbcfd3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved	*/
29 
30 /*
31  * Copyright 2019 OmniOS Community Edition (OmniOSce) Association.
32  */
33 
34 #include <stdio.h>
35 #include <err.h>
36 #include <sys/types.h>
37 #include <string.h>
38 #include <stdlib.h>
39 #include <ctype.h>
40 #include <assert.h>
41 #include <libcustr.h>
42 #include "cron.h"
43 
44 #ifdef PARSETEST
45 #define	xstrdup(x) strdup((x))
46 #endif
47 
48 #define	MAX_ELEMENTS 60
49 
50 #define	READNUMBER(x) \
51 	do { \
52 		(x) = (x) * 10 + (line[cursor] - '0'); \
53 		if ((x) > MAX_ELEMENTS) { \
54 			err = CFOUTOFBOUND; \
55 			goto out; \
56 		} \
57 	} while (isdigit(line[++cursor]))
58 
59 #define	ADDELEMENT(x)  \
60 	do { \
61 		if (eindex >= MAX_ELEMENTS) { \
62 			err = CFEOVERFLOW; \
63 			goto out; \
64 		} \
65 		elements[eindex++] = (x); \
66 	} while (0)
67 
68 /* A more restrictive version of isspace(3C) that only looks for space/tab */
69 #define	ISSPACE(x) \
70 	((x) == ' ' || (x) == '\t')
71 
72 cferror_t
73 next_field(uint_t lower, uint_t upper, char *line, int *cursorp, char **ret)
74 {
75 	uint_t elements[MAX_ELEMENTS];
76 	uint_t eindex = 0, i;
77 	int cursor = *cursorp;
78 	cferror_t err = CFOK;
79 
80 	assert(upper - lower <= MAX_ELEMENTS);
81 
82 	if (ret != NULL)
83 		*ret = NULL;
84 
85 	while (ISSPACE(line[cursor]))
86 		cursor++;
87 
88 	if (line[cursor] == '\0') {
89 		err = CFEOLN;
90 		goto out;
91 	}
92 
93 	for (;;) {
94 		uint_t num = 0, num2 = 0, step = 0;
95 
96 		if (line[cursor] == '*') {
97 			cursor++;
98 
99 			/* Short circuit for plain '*' */
100 			if (ISSPACE(line[cursor])) {
101 				if (ret != NULL)
102 					*ret = xstrdup("*");
103 				goto out;
104 			}
105 
106 			/*
107 			 * '*' is only permitted alongside other elements if
108 			 * it has an associated step.
109 			 */
110 
111 			if (line[cursor] != '/') {
112 				err = CFUNEXPECT;
113 				goto out;
114 			}
115 
116 			/* Treat it as a range covering all values */
117 			num = lower;
118 			num2 = upper;
119 		} else {
120 			if (!isdigit(line[cursor])) {
121 				err = CFUNEXPECT;
122 				goto out;
123 			}
124 
125 			READNUMBER(num);
126 
127 			if (num < lower || num > upper) {
128 				err = CFOUTOFBOUND;
129 				goto out;
130 			}
131 
132 			if (line[cursor] == '-') {
133 				cursor++;
134 				if (!isdigit(line[cursor])) {
135 					err = CFUNEXPECT;
136 					goto out;
137 				}
138 
139 				READNUMBER(num2);
140 
141 				if (num2 < lower || num2 > upper) {
142 					err = CFOUTOFBOUND;
143 					goto out;
144 				}
145 			} else {
146 				ADDELEMENT(num);
147 				goto next;
148 			}
149 		}
150 
151 		/* Look for a step definition */
152 		if (line[cursor] == '/') {
153 			cursor++;
154 			if (!isdigit(line[cursor])) {
155 				err = CFUNEXPECT;
156 				goto out;
157 			}
158 
159 			READNUMBER(step);
160 
161 			if (step == 0) {
162 				err = CFOUTOFBOUND;
163 				goto out;
164 			}
165 		} else {
166 			step = 1;
167 		}
168 
169 		if (num <= num2) {
170 			for (i = num; i <= num2; i += step) {
171 				ADDELEMENT(i);
172 			}
173 		} else {
174 			/* Wrap-around range */
175 			for (i = num; i <= upper; i += step) {
176 				ADDELEMENT(i);
177 			}
178 
179 			i -= (upper - lower + 1);
180 			for (; i <= num2; i += step) {
181 				ADDELEMENT(i);
182 			}
183 		}
184 
185 next:
186 
187 		if (line[cursor] != ',')
188 			break;
189 
190 		cursor++;
191 	}
192 
193 	if (line[cursor] == '\0') {
194 		err = CFEOLN;
195 		goto out;
196 	}
197 
198 	if (!ISSPACE(line[cursor])) {
199 		err = CFUNEXPECT;
200 		goto out;
201 	}
202 
203 	if (ret != NULL) {
204 		custr_t *cs = NULL;
205 
206 		if (custr_alloc(&cs) != 0) {
207 			err = CFENOMEM;
208 			goto out;
209 		}
210 
211 		for (i = 0; i < eindex; i++) {
212 			if (custr_len(cs) > 0) {
213 				if (custr_appendc(cs, ',') != 0) {
214 					custr_free(cs);
215 					err = CFENOMEM;
216 					goto out;
217 				}
218 			}
219 			if (custr_append_printf(cs, "%u", elements[i]) != 0) {
220 				custr_free(cs);
221 				err = CFENOMEM;
222 				goto out;
223 			}
224 		}
225 
226 		if (custr_len(cs) != 0)
227 			*ret = xstrdup(custr_cstr(cs));
228 		custr_free(cs);
229 	}
230 
231 out:
232 
233 	*cursorp = cursor;
234 
235 	return (err);
236 }
237 
238 #ifdef PARSETEST
239 int
240 main(int argc, char **argv)
241 {
242 	int lower, upper, cursor = 0;
243 	char *ret;
244 
245 	if (argc != 4)
246 		errx(1, "<lower> <upper> <string>");
247 
248 	lower = atoi(argv[1]);
249 	upper = atoi(argv[2]);
250 
251 	switch (next_field(lower, upper, argv[3], &cursor, &ret)) {
252 	case CFOK:
253 		(void) printf("%s\n", ret);
254 		break;
255 	case CFEOLN:
256 		(void) printf("UnexpectedEOL\n");
257 		break;
258 	case CFUNEXPECT:
259 		(void) printf("UnexpectedChar\n");
260 		break;
261 	case CFOUTOFBOUND:
262 		(void) printf("OutOfBounds\n");
263 		break;
264 	case CFEOVERFLOW:
265 		(void) printf("Overflow\n");
266 		break;
267 	case CFENOMEM:
268 		(void) printf("OutOfMemory\n");
269 		break;
270 	default:
271 		(void) printf("UnknownError\n");
272 		break;
273 	}
274 
275 	return (0);
276 }
277 #endif
278