1 /* $OpenBSD: ethers.c,v 1.7 1998/03/17 06:22:00 millert Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Todd C. Miller. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 22 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 23 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 24 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 25 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 26 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 27 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 28 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 29 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 30 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * ethers(3) a la Sun. 35 * Originally Written by Roland McGrath <roland@frob.com> 10/14/93. 36 * Substantially modified by Todd C. Miller <Todd.Miller@courtesan.com> 37 */ 38 39 #if defined(LIBC_SCCS) && !defined(lint) 40 static char rcsid[] = "$OpenBSD: ethers.c,v 1.7 1998/03/17 06:22:00 millert Exp $"; 41 #endif /* LIBC_SCCS and not lint */ 42 43 #include <sys/types.h> 44 #include <sys/socket.h> 45 #include <net/if.h> 46 #include <netinet/in.h> 47 #include <netinet/if_ether.h> 48 #include <sys/param.h> 49 #include <paths.h> 50 #include <errno.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <ctype.h> 55 56 #ifndef _PATH_ETHERS 57 #define _PATH_ETHERS "/etc/ethers" 58 #endif 59 60 static char * _ether_aton __P((char *, struct ether_addr *)); 61 62 char * 63 ether_ntoa(e) 64 struct ether_addr *e; 65 { 66 static char a[] = "xx:xx:xx:xx:xx:xx"; 67 68 if (e->ether_addr_octet[0] > 0xFF || e->ether_addr_octet[1] > 0xFF || 69 e->ether_addr_octet[2] > 0xFF || e->ether_addr_octet[3] > 0xFF || 70 e->ether_addr_octet[4] > 0xFF || e->ether_addr_octet[5] > 0xFF) { 71 errno = EINVAL; 72 return (NULL); 73 } 74 75 (void)sprintf(a, "%02x:%02x:%02x:%02x:%02x:%02x", 76 e->ether_addr_octet[0], e->ether_addr_octet[1], 77 e->ether_addr_octet[2], e->ether_addr_octet[3], 78 e->ether_addr_octet[4], e->ether_addr_octet[5]); 79 80 return (a); 81 } 82 83 static char * 84 _ether_aton(s, e) 85 char *s; 86 struct ether_addr *e; 87 { 88 int i; 89 long l; 90 char *pp; 91 92 while (isspace(*s)) 93 s++; 94 95 /* expect 6 hex octets separated by ':' or space/NUL if last octet */ 96 for (i = 0; i < 6; i++) { 97 l = strtol(s, &pp, 16); 98 if (pp == s || l > 0xFF) 99 return (NULL); 100 if (!(*pp == ':' || (i == 5 && (isspace(*pp) || *pp == '\0')))) 101 return (NULL); 102 e->ether_addr_octet[i] = (u_char)l; 103 s = pp + 1; 104 } 105 106 /* return character after the octets ala strtol(3) */ 107 return (pp); 108 } 109 110 struct ether_addr * 111 ether_aton(s) 112 char *s; 113 { 114 static struct ether_addr n; 115 116 return (_ether_aton(s, &n) ? &n : NULL); 117 } 118 119 int 120 ether_ntohost(hostname, e) 121 char *hostname; 122 struct ether_addr *e; 123 { 124 FILE *f; 125 char buf[BUFSIZ+1], *p; 126 size_t len; 127 struct ether_addr try; 128 129 if (e->ether_addr_octet[0] > 0xFF || e->ether_addr_octet[1] > 0xFF || 130 e->ether_addr_octet[2] > 0xFF || e->ether_addr_octet[3] > 0xFF || 131 e->ether_addr_octet[4] > 0xFF || e->ether_addr_octet[5] > 0xFF) { 132 errno = EINVAL; 133 return (-1); 134 } 135 136 #ifdef YP 137 char trybuf[sizeof("xx:xx:xx:xx:xx:xx")]; 138 int trylen; 139 140 sprintf(trybuf, "%x:%x:%x:%x:%x:%x", 141 e->ether_addr_octet[0], e->ether_addr_octet[1], 142 e->ether_addr_octet[2], e->ether_addr_octet[3], 143 e->ether_addr_octet[4], e->ether_addr_octet[5]); 144 trylen = strlen(trybuf); 145 #endif 146 147 f = fopen(_PATH_ETHERS, "r"); 148 if (f == NULL) 149 return (-1); 150 while ((p = fgetln(f, &len)) != NULL) { 151 if (p[len-1] == '\n') 152 len--; 153 if (len > sizeof(buf) - 2) 154 continue; 155 (void)memcpy(buf, p, len); 156 buf[len] = '\n'; /* code assumes newlines later on */ 157 buf[len+1] = '\0'; 158 #ifdef YP 159 /* A + in the file means try YP now. */ 160 if (!strncmp(buf, "+\n", sizeof(buf))) { 161 char *ypbuf, *ypdom; 162 int ypbuflen; 163 164 if (yp_get_default_domain(&ypdom)) 165 continue; 166 if (yp_match(ypdom, "ethers.byaddr", trybuf, 167 trylen, &ypbuf, &ypbuflen)) 168 continue; 169 if (ether_line(ypbuf, &try, hostname) == 0) { 170 free(ypbuf); 171 (void)fclose(f); 172 return (0); 173 } 174 free(ypbuf); 175 continue; 176 } 177 #endif 178 if (ether_line(buf, &try, hostname) == 0 && 179 memcmp((void *)&try, (void *)e, sizeof(try)) == 0) { 180 (void)fclose(f); 181 return (0); 182 } 183 } 184 (void)fclose(f); 185 errno = ENOENT; 186 return (-1); 187 } 188 189 int 190 ether_hostton(hostname, e) 191 char *hostname; 192 struct ether_addr *e; 193 { 194 FILE *f; 195 char buf[BUFSIZ+1], *p; 196 char try[MAXHOSTNAMELEN]; 197 size_t len; 198 #ifdef YP 199 int hostlen = strlen(hostname); 200 #endif 201 202 f = fopen(_PATH_ETHERS, "r"); 203 if (f==NULL) 204 return (-1); 205 206 while ((p = fgetln(f, &len)) != NULL) { 207 if (p[len-1] == '\n') 208 len--; 209 if (len > sizeof(buf) - 2) 210 continue; 211 memcpy(buf, p, len); 212 buf[len] = '\n'; /* code assumes newlines later on */ 213 buf[len+1] = '\0'; 214 #ifdef YP 215 /* A + in the file means try YP now. */ 216 if (!strncmp(buf, "+\n", sizeof(buf))) { 217 char *ypbuf, *ypdom; 218 int ypbuflen; 219 220 if (yp_get_default_domain(&ypdom)) 221 continue; 222 if (yp_match(ypdom, "ethers.byname", hostname, hostlen, 223 &ypbuf, &ypbuflen)) 224 continue; 225 if (ether_line(ypbuf, e, try) == 0) { 226 free(ypbuf); 227 (void)fclose(f); 228 return (0); 229 } 230 free(ypbuf); 231 continue; 232 } 233 #endif 234 if (ether_line(buf, e, try) == 0 && strcmp(hostname, try) == 0) { 235 (void)fclose(f); 236 return (0); 237 } 238 } 239 (void)fclose(f); 240 errno = ENOENT; 241 return (-1); 242 } 243 244 int 245 ether_line(line, e, hostname) 246 char *line; 247 struct ether_addr *e; 248 char *hostname; 249 { 250 char *p; 251 size_t n; 252 253 /* Parse "xx:xx:xx:xx:xx:xx" */ 254 if ((p = _ether_aton(line, e)) == NULL || (*p != ' ' && *p != '\t')) 255 goto bad; 256 257 /* Now get the hostname */ 258 while (isspace(*p)) 259 p++; 260 if (*p == '\0') 261 goto bad; 262 n = strcspn(p, " \t\n"); 263 if (n >= MAXHOSTNAMELEN) 264 goto bad; 265 (void)strncpy(hostname, p, n); 266 hostname[n] = '\0'; 267 return (0); 268 269 bad: 270 errno = EINVAL; 271 return (-1); 272 } 273