1 /*	$OpenBSD: name2id.c,v 1.4 2015/01/22 17:42:09 reyk Exp $	*/
2 
3 /*
4  * Copyright (c) 2004, 2005 Henning Brauer <henning@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER IN
15  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
16  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/queue.h>
21 
22 #include <stdlib.h>
23 #include <string.h>
24 #include <errno.h>
25 
26 #include "relayd.h"
27 
28 #define	IDVAL_MAX	50000
29 
30 struct n2id_label {
31 	TAILQ_ENTRY(n2id_label)	 entry;
32 	char			*name;
33 	u_int16_t		 id;
34 	int			 ref;
35 };
36 
37 TAILQ_HEAD(n2id_labels, n2id_label);
38 
39 u_int16_t	 _name2id(struct n2id_labels *, const char *);
40 const char	*_id2name(struct n2id_labels *, u_int16_t);
41 void		 _unref(struct n2id_labels *, u_int16_t);
42 void		 _ref(struct n2id_labels *, u_int16_t);
43 
44 struct n2id_labels	relay_labels = TAILQ_HEAD_INITIALIZER(relay_labels);
45 struct n2id_labels	relay_tags = TAILQ_HEAD_INITIALIZER(relay_tags);
46 
47 u_int16_t
48 tag_name2id(const char *name)
49 {
50 	return (_name2id(&relay_tags, name));
51 }
52 
53 const char *
54 tag_id2name(u_int16_t id)
55 {
56 	return (_id2name(&relay_tags, id));
57 }
58 
59 void
60 tag_unref(u_int16_t id)
61 {
62 	_unref(&relay_tags, id);
63 }
64 
65 void
66 tag_ref(u_int16_t id)
67 {
68 	_ref(&relay_tags, id);
69 }
70 
71 u_int16_t
72 label_name2id(const char *name)
73 {
74 	return (_name2id(&relay_labels, name));
75 }
76 
77 const char *
78 label_id2name(u_int16_t id)
79 {
80 	return (_id2name(&relay_labels, id));
81 }
82 
83 void
84 label_unref(u_int16_t id)
85 {
86 	_unref(&relay_labels, id);
87 }
88 
89 void
90 label_ref(u_int16_t id)
91 {
92 	_ref(&relay_labels, id);
93 }
94 
95 u_int16_t
96 _name2id(struct n2id_labels *head, const char *name)
97 {
98 	struct n2id_label	*label, *p = NULL;
99 	u_int16_t		 new_id = 1;
100 
101 	if (!name[0]) {
102 		errno = EINVAL;
103 		return (0);
104 	}
105 
106 	TAILQ_FOREACH(label, head, entry)
107 		if (strcmp(name, label->name) == 0) {
108 			label->ref++;
109 			return (label->id);
110 		}
111 
112 	/*
113 	 * to avoid fragmentation, we do a linear search from the beginning
114 	 * and take the first free slot we find. if there is none or the list
115 	 * is empty, append a new entry at the end.
116 	 */
117 
118 	if (!TAILQ_EMPTY(head))
119 		for (p = TAILQ_FIRST(head); p != NULL &&
120 		    p->id == new_id; p = TAILQ_NEXT(p, entry))
121 			new_id = p->id + 1;
122 
123 	if (new_id > IDVAL_MAX) {
124 		errno = ERANGE;
125 		return (0);
126 	}
127 
128 	if ((label = calloc(1, sizeof(struct n2id_label))) == NULL)
129 		return (0);
130 	if ((label->name = strdup(name)) == NULL) {
131 		free(label);
132 		return (0);
133 	}
134 	label->id = new_id;
135 	label->ref++;
136 
137 	if (p != NULL)	/* insert new entry before p */
138 		TAILQ_INSERT_BEFORE(p, label, entry);
139 	else		/* either list empty or no free slot in between */
140 		TAILQ_INSERT_TAIL(head, label, entry);
141 
142 	return (label->id);
143 }
144 
145 const char *
146 _id2name(struct n2id_labels *head, u_int16_t id)
147 {
148 	struct n2id_label	*label;
149 
150 	if (id == 0)
151 		return ("");
152 
153 	TAILQ_FOREACH(label, head, entry)
154 		if (label->id == id)
155 			return (label->name);
156 
157 	return ("");
158 }
159 
160 void
161 _unref(struct n2id_labels *head, u_int16_t id)
162 {
163 	struct n2id_label	*p, *next;
164 
165 	if (id == 0)
166 		return;
167 
168 	for (p = TAILQ_FIRST(head); p != NULL; p = next) {
169 		next = TAILQ_NEXT(p, entry);
170 		if (id == p->id) {
171 			if (--p->ref == 0) {
172 				TAILQ_REMOVE(head, p, entry);
173 				free(p->name);
174 				free(p);
175 			}
176 			break;
177 		}
178 	}
179 }
180 
181 void
182 _ref(struct n2id_labels *head, u_int16_t id)
183 {
184 	struct n2id_label	*label;
185 
186 	if (id == 0)
187 		return;
188 
189 	TAILQ_FOREACH(label, head, entry)
190 		if (label->id == id) {
191 			++label->ref;
192 			break;
193 		}
194 }