1 /* 2 * Copyright (c) 1995 3 * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by Bill Paul. 16 * 4. Neither the name of the author nor the names of any co-contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * ethernet address conversion and lookup routines 33 * 34 * Written by Bill Paul <wpaul@ctr.columbia.edu> 35 * Center for Telecommunications Research 36 * Columbia University, New York City 37 * 38 * $FreeBSD: src/lib/libc/net/ether_addr.c,v 1.10.2.5 2002/04/08 08:01:50 ru Exp $ 39 * $DragonFly: src/lib/libc/net/ether_addr.c,v 1.2 2003/06/17 04:26:44 dillon Exp $ 40 */ 41 42 #include <stdio.h> 43 #include <paths.h> 44 #include <sys/types.h> 45 #include <string.h> 46 #include <stdlib.h> 47 #include <sys/param.h> 48 #include <sys/socket.h> 49 #include <net/ethernet.h> 50 #ifdef YP 51 #include <rpc/rpc.h> 52 #include <rpcsvc/yp_prot.h> 53 #include <rpcsvc/ypclnt.h> 54 #endif 55 56 #ifndef _PATH_ETHERS 57 #define _PATH_ETHERS "/etc/ethers" 58 #endif 59 60 /* 61 * Parse a string of text containing an ethernet address and hostname 62 * and separate it into its component parts. 63 */ 64 int 65 ether_line(l, e, hostname) 66 const char *l; 67 struct ether_addr *e; 68 char *hostname; 69 { 70 int i, o[6]; 71 72 i = sscanf(l, "%x:%x:%x:%x:%x:%x %s", &o[0], &o[1], &o[2], 73 &o[3], &o[4], &o[5], 74 hostname); 75 if (i != 7) 76 return (i); 77 78 for (i=0; i<6; i++) 79 e->octet[i] = o[i]; 80 return (0); 81 } 82 83 /* 84 * Convert an ASCII representation of an ethernet address to 85 * binary form. 86 */ 87 struct 88 ether_addr *ether_aton(a) 89 const char *a; 90 { 91 int i; 92 static struct ether_addr o; 93 unsigned int o0, o1, o2, o3, o4, o5; 94 95 i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o0, &o1, &o2, &o3, &o4, &o5); 96 97 if (i != 6) 98 return (NULL); 99 100 o.octet[0]=o0; 101 o.octet[1]=o1; 102 o.octet[2]=o2; 103 o.octet[3]=o3; 104 o.octet[4]=o4; 105 o.octet[5]=o5; 106 107 return ((struct ether_addr *)&o); 108 } 109 110 /* 111 * Convert a binary representation of an ethernet address to 112 * an ASCII string. 113 */ 114 char 115 *ether_ntoa(n) 116 const struct ether_addr *n; 117 { 118 int i; 119 static char a[18]; 120 121 i = sprintf(a, "%02x:%02x:%02x:%02x:%02x:%02x", 122 n->octet[0], n->octet[1], n->octet[2], 123 n->octet[3], n->octet[4], n->octet[5]); 124 if (i < 17) 125 return (NULL); 126 return ((char *)&a); 127 } 128 129 /* 130 * Map an ethernet address to a hostname. Use either /etc/ethers or 131 * NIS/YP. 132 */ 133 int 134 ether_ntohost(hostname, e) 135 char *hostname; 136 const struct ether_addr *e; 137 { 138 FILE *fp; 139 char buf[BUFSIZ + 2]; 140 struct ether_addr local_ether; 141 char local_host[MAXHOSTNAMELEN]; 142 #ifdef YP 143 char *result; 144 int resultlen; 145 char *ether_a; 146 char *yp_domain; 147 #endif 148 if ((fp = fopen(_PATH_ETHERS, "r")) == NULL) 149 return (1); 150 151 while (fgets(buf,BUFSIZ,fp)) { 152 if (buf[0] == '#') 153 continue; 154 #ifdef YP 155 if (buf[0] == '+') { 156 if (yp_get_default_domain(&yp_domain)) 157 continue; 158 ether_a = ether_ntoa(e); 159 if (yp_match(yp_domain, "ethers.byaddr", ether_a, 160 strlen(ether_a), &result, &resultlen)) { 161 continue; 162 } 163 strncpy(buf, result, resultlen); 164 buf[resultlen] = '\0'; 165 free(result); 166 } 167 #endif 168 if (!ether_line(buf, &local_ether, local_host)) { 169 if (!bcmp((char *)&local_ether.octet[0], 170 (char *)&e->octet[0], 6)) { 171 /* We have a match */ 172 strcpy(hostname, local_host); 173 fclose(fp); 174 return(0); 175 } 176 } 177 } 178 fclose(fp); 179 return (1); 180 } 181 182 /* 183 * Map a hostname to an ethernet address using /etc/ethers or 184 * NIS/YP. 185 */ 186 int 187 ether_hostton(hostname, e) 188 const char *hostname; 189 struct ether_addr *e; 190 { 191 FILE *fp; 192 char buf[BUFSIZ + 2]; 193 struct ether_addr local_ether; 194 char local_host[MAXHOSTNAMELEN]; 195 #ifdef YP 196 char *result; 197 int resultlen; 198 char *yp_domain; 199 #endif 200 if ((fp = fopen(_PATH_ETHERS, "r")) == NULL) 201 return (1); 202 203 while (fgets(buf,BUFSIZ,fp)) { 204 if (buf[0] == '#') 205 continue; 206 #ifdef YP 207 if (buf[0] == '+') { 208 if (yp_get_default_domain(&yp_domain)) 209 continue; 210 if (yp_match(yp_domain, "ethers.byname", hostname, 211 strlen(hostname), &result, &resultlen)) { 212 continue; 213 } 214 strncpy(buf, result, resultlen); 215 buf[resultlen] = '\0'; 216 free(result); 217 } 218 #endif 219 if (!ether_line(buf, &local_ether, local_host)) { 220 if (!strcmp(hostname, local_host)) { 221 /* We have a match */ 222 bcopy((char *)&local_ether.octet[0], 223 (char *)&e->octet[0], 6); 224 fclose(fp); 225 return(0); 226 } 227 } 228 } 229 fclose(fp); 230 return (1); 231 } 232