name2id.c revision 1.1
1/* $OpenBSD: name2id.c,v 1.1 2007/01/08 13:01:10 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 "ripd.h" 29 30#define IDVAL_MAX 50000 31 32struct n2id_label { 33 TAILQ_ENTRY(n2id_label) entry; 34 char *name; 35 u_int16_t id; 36 int ref; 37}; 38 39TAILQ_HEAD(n2id_labels, n2id_label); 40 41u_int16_t _name2id(struct n2id_labels *, const char *); 42const char *_id2name(struct n2id_labels *, u_int16_t); 43void _unref(struct n2id_labels *, u_int16_t); 44void _ref(struct n2id_labels *, u_int16_t); 45 46struct n2id_labels rt_labels = TAILQ_HEAD_INITIALIZER(rt_labels); 47 48u_int16_t 49rtlabel_name2id(const char *name) 50{ 51 return (_name2id(&rt_labels, name)); 52} 53 54const char * 55rtlabel_id2name(u_int16_t id) 56{ 57 return (_id2name(&rt_labels, id)); 58} 59 60void 61rtlabel_unref(u_int16_t id) 62{ 63 _unref(&rt_labels, id); 64} 65 66/* 67void 68rtlabel_ref(u_int16_t id) 69{ 70 _ref(&rt_labels, id); 71} 72*/ 73 74u_int16_t 75_name2id(struct n2id_labels *head, const char *name) 76{ 77 struct n2id_label *label, *p = NULL; 78 u_int16_t new_id = 1; 79 80 if (!name[0]) { 81 errno = EINVAL; 82 return (0); 83 } 84 85 TAILQ_FOREACH(label, head, entry) 86 if (strcmp(name, label->name) == 0) { 87 label->ref++; 88 return (label->id); 89 } 90 91 /* 92 * to avoid fragmentation, we do a linear search from the beginning 93 * and take the first free slot we find. if there is none or the list 94 * is empty, append a new entry at the end. 95 */ 96 97 if (!TAILQ_EMPTY(head)) 98 for (p = TAILQ_FIRST(head); p != NULL && 99 p->id == new_id; p = TAILQ_NEXT(p, entry)) 100 new_id = p->id + 1; 101 102 if (new_id > IDVAL_MAX) { 103 errno = ERANGE; 104 return (0); 105 } 106 107 if ((label = calloc(1, sizeof(struct n2id_label))) == NULL) 108 return (0); 109 if ((label->name = strdup(name)) == NULL) { 110 free(label); 111 return (0); 112 } 113 label->id = new_id; 114 label->ref++; 115 116 if (p != NULL) /* insert new entry before p */ 117 TAILQ_INSERT_BEFORE(p, label, entry); 118 else /* either list empty or no free slot in between */ 119 TAILQ_INSERT_TAIL(head, label, entry); 120 121 return (label->id); 122} 123 124const char * 125_id2name(struct n2id_labels *head, u_int16_t id) 126{ 127 struct n2id_label *label; 128 129 if (id == 0) 130 return (""); 131 132 TAILQ_FOREACH(label, head, entry) 133 if (label->id == id) 134 return (label->name); 135 136 return (""); 137} 138 139void 140_unref(struct n2id_labels *head, u_int16_t id) 141{ 142 struct n2id_label *p, *next; 143 144 if (id == 0) 145 return; 146 147 for (p = TAILQ_FIRST(head); p != NULL; p = next) { 148 next = TAILQ_NEXT(p, entry); 149 if (id == p->id) { 150 if (--p->ref == 0) { 151 TAILQ_REMOVE(head, p, entry); 152 free(p->name); 153 free(p); 154 } 155 break; 156 } 157 } 158} 159 160void 161_ref(struct n2id_labels *head, u_int16_t id) 162{ 163 struct n2id_label *label; 164 165 if (id == 0) 166 return; 167 168 TAILQ_FOREACH(label, head, entry) 169 if (label->id == id) { 170 ++label->ref; 171 break; 172 } 173} 174