1 /*	$OpenBSD: name2id.c,v 1.10 2018/06/29 11:45:50 claudio 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/socket.h>
21 
22 #include <net/route.h>
23 
24 #include <errno.h>
25 #include <stdlib.h>
26 #include <string.h>
27 
28 #include "bgpd.h"
29 
30 #define	IDVAL_MAX	50000
31 
32 struct n2id_label {
33 	TAILQ_ENTRY(n2id_label)	 entry;
34 	char			*name;
35 	u_int16_t		 id;
36 	int			 ref;
37 };
38 
39 TAILQ_HEAD(n2id_labels, n2id_label);
40 
41 u_int16_t	 _name2id(struct n2id_labels *, const char *);
42 const char	*_id2name(struct n2id_labels *, u_int16_t);
43 void		 _unref(struct n2id_labels *, u_int16_t);
44 u_int16_t	 _ref(struct n2id_labels *, u_int16_t);
45 
46 struct n2id_labels	rt_labels = TAILQ_HEAD_INITIALIZER(rt_labels);
47 struct n2id_labels	pftable_labels = TAILQ_HEAD_INITIALIZER(pftable_labels);
48 
49 u_int16_t
rtlabel_name2id(const char * name)50 rtlabel_name2id(const char *name)
51 {
52 	return (_name2id(&rt_labels, name));
53 }
54 
55 const char *
rtlabel_id2name(u_int16_t id)56 rtlabel_id2name(u_int16_t id)
57 {
58 	return (_id2name(&rt_labels, id));
59 }
60 
61 void
rtlabel_unref(u_int16_t id)62 rtlabel_unref(u_int16_t id)
63 {
64 	_unref(&rt_labels, id);
65 }
66 
67 u_int16_t
rtlabel_ref(u_int16_t id)68 rtlabel_ref(u_int16_t id)
69 {
70 	return (_ref(&rt_labels, id));
71 }
72 
73 u_int16_t
pftable_name2id(const char * name)74 pftable_name2id(const char *name)
75 {
76 	return (_name2id(&pftable_labels, name));
77 }
78 
79 const char *
pftable_id2name(u_int16_t id)80 pftable_id2name(u_int16_t id)
81 {
82 	return (_id2name(&pftable_labels, id));
83 }
84 
85 void
pftable_unref(u_int16_t id)86 pftable_unref(u_int16_t id)
87 {
88 	_unref(&pftable_labels, id);
89 }
90 
91 u_int16_t
pftable_ref(u_int16_t id)92 pftable_ref(u_int16_t id)
93 {
94 	return (_ref(&pftable_labels, id));
95 }
96 
97 u_int16_t
_name2id(struct n2id_labels * head,const char * name)98 _name2id(struct n2id_labels *head, const char *name)
99 {
100 	struct n2id_label	*label, *p = NULL;
101 	u_int16_t		 new_id = 1;
102 
103 	if (!name[0]) {
104 		errno = EINVAL;
105 		return (0);
106 	}
107 
108 	TAILQ_FOREACH(label, head, entry)
109 		if (strcmp(name, label->name) == 0) {
110 			label->ref++;
111 			return (label->id);
112 		}
113 
114 	/*
115 	 * to avoid fragmentation, we do a linear search from the beginning
116 	 * and take the first free slot we find. if there is none or the list
117 	 * is empty, append a new entry at the end.
118 	 */
119 
120 	if (!TAILQ_EMPTY(head))
121 		for (p = TAILQ_FIRST(head); p != NULL &&
122 		    p->id == new_id; p = TAILQ_NEXT(p, entry))
123 			new_id = p->id + 1;
124 
125 	if (new_id > IDVAL_MAX) {
126 		errno = ERANGE;
127 		return (0);
128 	}
129 
130 	if ((label = calloc(1, sizeof(struct n2id_label))) == NULL)
131 		return (0);
132 	if ((label->name = strdup(name)) == NULL) {
133 		free(label);
134 		return (0);
135 	}
136 	label->id = new_id;
137 	label->ref++;
138 
139 	if (p != NULL)	/* insert new entry before p */
140 		TAILQ_INSERT_BEFORE(p, label, entry);
141 	else		/* either list empty or no free slot in between */
142 		TAILQ_INSERT_TAIL(head, label, entry);
143 
144 	return (label->id);
145 }
146 
147 const char *
_id2name(struct n2id_labels * head,u_int16_t id)148 _id2name(struct n2id_labels *head, u_int16_t id)
149 {
150 	struct n2id_label	*label;
151 
152 	if (id == 0)
153 		return ("");
154 
155 	TAILQ_FOREACH(label, head, entry)
156 		if (label->id == id)
157 			return (label->name);
158 
159 	return ("");
160 }
161 
162 void
_unref(struct n2id_labels * head,u_int16_t id)163 _unref(struct n2id_labels *head, u_int16_t id)
164 {
165 	struct n2id_label	*p, *next;
166 
167 	if (id == 0)
168 		return;
169 
170 	for (p = TAILQ_FIRST(head); p != NULL; p = next) {
171 		next = TAILQ_NEXT(p, entry);
172 		if (id == p->id) {
173 			if (--p->ref == 0) {
174 				TAILQ_REMOVE(head, p, entry);
175 				free(p->name);
176 				free(p);
177 			}
178 			break;
179 		}
180 	}
181 }
182 
183 u_int16_t
_ref(struct n2id_labels * head,u_int16_t id)184 _ref(struct n2id_labels *head, u_int16_t id)
185 {
186 	struct n2id_label	*label;
187 
188 	if (id == 0)
189 		return (0);
190 
191 	TAILQ_FOREACH(label, head, entry)
192 		if (label->id == id) {
193 			++label->ref;
194 			return (id);
195 		}
196 
197 	/* id not found, treat like no id  */
198 	return (0);
199 }
200