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 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 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,"%x:%x:%x:%x:%x:%x",n->octet[0],n->octet[1],n->octet[2], 122 n->octet[3],n->octet[4],n->octet[5]); 123 if (i < 11) 124 return (NULL); 125 return ((char *)&a); 126 } 127 128 /* 129 * Map an ethernet address to a hostname. Use either /etc/ethers or 130 * NIS/YP. 131 */ 132 int 133 ether_ntohost(hostname, e) 134 char *hostname; 135 const struct ether_addr *e; 136 { 137 FILE *fp; 138 char buf[BUFSIZ + 2]; 139 struct ether_addr local_ether; 140 char local_host[MAXHOSTNAMELEN]; 141 #ifdef YP 142 char *result; 143 int resultlen; 144 char *ether_a; 145 char *yp_domain; 146 #endif 147 if ((fp = fopen(_PATH_ETHERS, "r")) == NULL) 148 return (1); 149 150 while (fgets(buf,BUFSIZ,fp)) { 151 if (buf[0] == '#') 152 continue; 153 #ifdef YP 154 if (buf[0] == '+') { 155 if (yp_get_default_domain(&yp_domain)) 156 continue; 157 ether_a = ether_ntoa(e); 158 if (yp_match(yp_domain, "ethers.byaddr", ether_a, 159 strlen(ether_a), &result, &resultlen)) { 160 continue; 161 } 162 strncpy(buf, result, resultlen); 163 buf[resultlen] = '\0'; 164 free(result); 165 } 166 #endif 167 if (!ether_line(buf, &local_ether, local_host)) { 168 if (!bcmp((char *)&local_ether.octet[0], 169 (char *)&e->octet[0], 6)) { 170 /* We have a match */ 171 strcpy(hostname, local_host); 172 fclose(fp); 173 return(0); 174 } 175 } 176 } 177 fclose(fp); 178 return (1); 179 } 180 181 /* 182 * Map a hostname to an ethernet address using /etc/ethers or 183 * NIS/YP. 184 */ 185 int 186 ether_hostton(hostname, e) 187 const char *hostname; 188 struct ether_addr *e; 189 { 190 FILE *fp; 191 char buf[BUFSIZ + 2]; 192 struct ether_addr local_ether; 193 char local_host[MAXHOSTNAMELEN]; 194 #ifdef YP 195 char *result; 196 int resultlen; 197 char *yp_domain; 198 #endif 199 if ((fp = fopen(_PATH_ETHERS, "r")) == NULL) 200 return (1); 201 202 while (fgets(buf,BUFSIZ,fp)) { 203 if (buf[0] == '#') 204 continue; 205 #ifdef YP 206 if (buf[0] == '+') { 207 if (yp_get_default_domain(&yp_domain)) 208 continue; 209 if (yp_match(yp_domain, "ethers.byname", hostname, 210 strlen(hostname), &result, &resultlen)) { 211 continue; 212 } 213 strncpy(buf, result, resultlen); 214 buf[resultlen] = '\0'; 215 free(result); 216 } 217 #endif 218 if (!ether_line(buf, &local_ether, local_host)) { 219 if (!strcmp(hostname, local_host)) { 220 /* We have a match */ 221 bcopy((char *)&local_ether.octet[0], 222 (char *)&e->octet[0], 6); 223 fclose(fp); 224 return(0); 225 } 226 } 227 } 228 fclose(fp); 229 return (1); 230 } 231