xref: /openbsd/usr.sbin/relayd/name2id.c (revision 404b540a)
1 /*	$OpenBSD: name2id.c,v 1.2 2007/12/07 17:17:00 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/param.h>
20 #include <sys/socket.h>
21 #include <sys/queue.h>
22 
23 #include <net/if.h>
24 
25 #include <stdlib.h>
26 #include <stdio.h>
27 #include <string.h>
28 #include <errno.h>
29 #include <event.h>
30 
31 #include <openssl/ssl.h>
32 
33 #include "relayd.h"
34 
35 #define	IDVAL_MAX	50000
36 
37 struct n2id_label {
38 	TAILQ_ENTRY(n2id_label)	 entry;
39 	char			*name;
40 	u_int16_t		 id;
41 	int			 ref;
42 };
43 
44 TAILQ_HEAD(n2id_labels, n2id_label);
45 
46 u_int16_t	 _name2id(struct n2id_labels *, const char *);
47 const char	*_id2name(struct n2id_labels *, u_int16_t);
48 void		 _unref(struct n2id_labels *, u_int16_t);
49 void		 _ref(struct n2id_labels *, u_int16_t);
50 
51 /* for protocolnode labels */
52 struct n2id_labels	pn_labels = TAILQ_HEAD_INITIALIZER(pn_labels);
53 
54 u_int16_t
55 pn_name2id(const char *name)
56 {
57 	return (_name2id(&pn_labels, name));
58 }
59 
60 const char *
61 pn_id2name(u_int16_t id)
62 {
63 	return (_id2name(&pn_labels, id));
64 }
65 
66 void
67 pn_unref(u_int16_t id)
68 {
69 	_unref(&pn_labels, id);
70 }
71 
72 void
73 pn_ref(u_int16_t id)
74 {
75 	_ref(&pn_labels, id);
76 }
77 
78 u_int16_t
79 _name2id(struct n2id_labels *head, const char *name)
80 {
81 	struct n2id_label	*label, *p = NULL;
82 	u_int16_t		 new_id = 1;
83 
84 	if (!name[0]) {
85 		errno = EINVAL;
86 		return (0);
87 	}
88 
89 	TAILQ_FOREACH(label, head, entry)
90 		if (strcmp(name, label->name) == 0) {
91 			label->ref++;
92 			return (label->id);
93 		}
94 
95 	/*
96 	 * to avoid fragmentation, we do a linear search from the beginning
97 	 * and take the first free slot we find. if there is none or the list
98 	 * is empty, append a new entry at the end.
99 	 */
100 
101 	if (!TAILQ_EMPTY(head))
102 		for (p = TAILQ_FIRST(head); p != NULL &&
103 		    p->id == new_id; p = TAILQ_NEXT(p, entry))
104 			new_id = p->id + 1;
105 
106 	if (new_id > IDVAL_MAX) {
107 		errno = ERANGE;
108 		return (0);
109 	}
110 
111 	if ((label = calloc(1, sizeof(struct n2id_label))) == NULL)
112 		return (0);
113 	if ((label->name = strdup(name)) == NULL) {
114 		free(label);
115 		return (0);
116 	}
117 	label->id = new_id;
118 	label->ref++;
119 
120 	if (p != NULL)	/* insert new entry before p */
121 		TAILQ_INSERT_BEFORE(p, label, entry);
122 	else		/* either list empty or no free slot in between */
123 		TAILQ_INSERT_TAIL(head, label, entry);
124 
125 	return (label->id);
126 }
127 
128 const char *
129 _id2name(struct n2id_labels *head, u_int16_t id)
130 {
131 	struct n2id_label	*label;
132 
133 	if (id == 0)
134 		return ("");
135 
136 	TAILQ_FOREACH(label, head, entry)
137 		if (label->id == id)
138 			return (label->name);
139 
140 	return ("");
141 }
142 
143 void
144 _unref(struct n2id_labels *head, u_int16_t id)
145 {
146 	struct n2id_label	*p, *next;
147 
148 	if (id == 0)
149 		return;
150 
151 	for (p = TAILQ_FIRST(head); p != NULL; p = next) {
152 		next = TAILQ_NEXT(p, entry);
153 		if (id == p->id) {
154 			if (--p->ref == 0) {
155 				TAILQ_REMOVE(head, p, entry);
156 				free(p->name);
157 				free(p);
158 			}
159 			break;
160 		}
161 	}
162 }
163 
164 void
165 _ref(struct n2id_labels *head, u_int16_t id)
166 {
167 	struct n2id_label	*label;
168 
169 	if (id == 0)
170 		return;
171 
172 	TAILQ_FOREACH(label, head, entry)
173 		if (label->id == id) {
174 			++label->ref;
175 			break;
176 		}
177 }
178