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 1.4 2005/11/13 02:04:47 swildner 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(const char *l, struct ether_addr *e, char *hostname) 66 { 67 int i, o[6]; 68 69 i = sscanf(l, "%x:%x:%x:%x:%x:%x %s", &o[0], &o[1], &o[2], 70 &o[3], &o[4], &o[5], 71 hostname); 72 if (i != 7) 73 return (i); 74 75 for (i=0; i<6; i++) 76 e->octet[i] = o[i]; 77 return (0); 78 } 79 80 /* 81 * Convert an ASCII representation of an ethernet address to 82 * binary form. 83 */ 84 struct ether_addr * 85 ether_aton(const char *a) 86 { 87 int i; 88 static struct ether_addr o; 89 unsigned int o0, o1, o2, o3, o4, o5; 90 91 i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o0, &o1, &o2, &o3, &o4, &o5); 92 93 if (i != 6) 94 return (NULL); 95 96 o.octet[0]=o0; 97 o.octet[1]=o1; 98 o.octet[2]=o2; 99 o.octet[3]=o3; 100 o.octet[4]=o4; 101 o.octet[5]=o5; 102 103 return ((struct ether_addr *)&o); 104 } 105 106 /* 107 * Convert a binary representation of an ethernet address to 108 * an ASCII string. 109 */ 110 char * 111 ether_ntoa(const struct ether_addr *n) 112 { 113 int i; 114 static char a[18]; 115 116 i = sprintf(a, "%02x:%02x:%02x:%02x:%02x:%02x", 117 n->octet[0], n->octet[1], n->octet[2], 118 n->octet[3], n->octet[4], n->octet[5]); 119 if (i < 17) 120 return (NULL); 121 return ((char *)&a); 122 } 123 124 /* 125 * Map an ethernet address to a hostname. Use either /etc/ethers or 126 * NIS/YP. 127 */ 128 int 129 ether_ntohost(char *hostname, const struct ether_addr *e) 130 { 131 FILE *fp; 132 char buf[BUFSIZ + 2]; 133 struct ether_addr local_ether; 134 char local_host[MAXHOSTNAMELEN]; 135 #ifdef YP 136 char *result; 137 int resultlen; 138 char *ether_a; 139 char *yp_domain; 140 #endif 141 if ((fp = fopen(_PATH_ETHERS, "r")) == NULL) 142 return (1); 143 144 while (fgets(buf,BUFSIZ,fp)) { 145 if (buf[0] == '#') 146 continue; 147 #ifdef YP 148 if (buf[0] == '+') { 149 if (yp_get_default_domain(&yp_domain)) 150 continue; 151 ether_a = ether_ntoa(e); 152 if (yp_match(yp_domain, "ethers.byaddr", ether_a, 153 strlen(ether_a), &result, &resultlen)) { 154 continue; 155 } 156 strncpy(buf, result, resultlen); 157 buf[resultlen] = '\0'; 158 free(result); 159 } 160 #endif 161 if (!ether_line(buf, &local_ether, local_host)) { 162 if (!bcmp((char *)&local_ether.octet[0], 163 (char *)&e->octet[0], 6)) { 164 /* We have a match */ 165 strcpy(hostname, local_host); 166 fclose(fp); 167 return(0); 168 } 169 } 170 } 171 fclose(fp); 172 return (1); 173 } 174 175 /* 176 * Map a hostname to an ethernet address using /etc/ethers or 177 * NIS/YP. 178 */ 179 int 180 ether_hostton(const char *hostname, struct ether_addr *e) 181 { 182 FILE *fp; 183 char buf[BUFSIZ + 2]; 184 struct ether_addr local_ether; 185 char local_host[MAXHOSTNAMELEN]; 186 #ifdef YP 187 char *result; 188 int resultlen; 189 char *yp_domain; 190 #endif 191 if ((fp = fopen(_PATH_ETHERS, "r")) == NULL) 192 return (1); 193 194 while (fgets(buf,BUFSIZ,fp)) { 195 if (buf[0] == '#') 196 continue; 197 #ifdef YP 198 if (buf[0] == '+') { 199 if (yp_get_default_domain(&yp_domain)) 200 continue; 201 if (yp_match(yp_domain, "ethers.byname", hostname, 202 strlen(hostname), &result, &resultlen)) { 203 continue; 204 } 205 strncpy(buf, result, resultlen); 206 buf[resultlen] = '\0'; 207 free(result); 208 } 209 #endif 210 if (!ether_line(buf, &local_ether, local_host)) { 211 if (!strcmp(hostname, local_host)) { 212 /* We have a match */ 213 bcopy((char *)&local_ether.octet[0], 214 (char *)&e->octet[0], 6); 215 fclose(fp); 216 return(0); 217 } 218 } 219 } 220 fclose(fp); 221 return (1); 222 } 223