xref: /dragonfly/usr.sbin/mtree/only.c (revision ed183f8c)
1 /*	$NetBSD: only.c,v 1.3 2017/09/07 04:04:13 nakayama Exp $	*/
2 
3 /*-
4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christos Zoulas.
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  * 3. Neither the name of The NetBSD Foundation nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 #if HAVE_NBTOOL_CONFIG_H
35 #include "nbtool_config.h"
36 #endif
37 
38 #include <sys/param.h>
39 
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <stdbool.h>
44 #include <time.h>
45 #include <err.h>
46 #include <util.h>
47 
48 #include "extern.h"
49 
50 struct hentry {
51 	char *str;
52 	uint32_t hash;
53 	struct hentry *next;
54 };
55 
56 static struct hentry *table[1024];
57 static bool loaded;
58 
59 static uint32_t
60 hash_str(const char *str)
61 {
62 	const uint8_t *s = (const uint8_t *)str;
63 	uint8_t c;
64 	uint32_t hash = 0;
65 	while ((c = *s++) != '\0')
66 		hash = hash * 33 + c;           /* "perl": k=33, r=r+r/32 */
67 	return hash + (hash >> 5);
68 }
69 
70 static bool
71 hash_find(const char *str, uint32_t *h)
72 {
73 	struct hentry *e;
74 	*h = hash_str(str) % NELEM(table);
75 
76 	for (e = table[*h]; e; e = e->next)
77 		if (e->hash == *h && strcmp(e->str, str) == 0)
78 			return true;
79 	return false;
80 }
81 
82 static void
83 hash_insert(char *str, uint32_t h)
84 {
85 	struct hentry *e;
86 	char *x;
87 
88 	if ((e = malloc(sizeof(*e))) == NULL)
89 		mtree_err("memory allocation error");
90 	if ((x = strdup(str)) == NULL)
91 		mtree_err("memory allocation error");
92 
93 	e->str = x;
94 	e->hash = h;
95 	e->next = table[h];
96 	table[h] = e;
97 }
98 
99 static void
100 fill(char *str)
101 {
102 	uint32_t h;
103 	char *ptr = strrchr(str, '/');
104 
105 	if (ptr == NULL)
106 		return;
107 
108 	*ptr = '\0';
109 	if (!hash_find(str, &h)) {
110 		hash_insert(str, h);
111 		fill(str);
112 	}
113 	*ptr = '/';
114 }
115 
116 void
117 load_only(const char *fname)
118 {
119 	FILE *fp;
120 	char *line;
121 	size_t len, lineno;
122 
123 	if ((fp = fopen(fname, "r")) == NULL)
124 		err(1, "Cannot open `%s'", fname);
125 
126 	while ((line = fparseln(fp, &len, &lineno, NULL, FPARSELN_UNESCALL))) {
127 		uint32_t h;
128 		if (hash_find(line, &h))
129 			err(1, "Duplicate entry %s", line);
130 		hash_insert(line, h);
131 		fill(line);
132 		free(line);
133 	}
134 
135 	fclose(fp);
136 	loaded = true;
137 }
138 
139 bool
140 find_only(const char *path)
141 {
142 	uint32_t h;
143 
144 	if (!loaded)
145 		return true;
146 	return hash_find(path, &h);
147 }
148