1 /* $OpenBSD: ethers.c,v 1.12 2001/06/27 00:58:54 lebel 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. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 19 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY 20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 21 * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 22 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 26 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 27 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * ethers(3) a la Sun. 32 * Originally Written by Roland McGrath <roland@frob.com> 10/14/93. 33 * Substantially modified by Todd C. Miller <Todd.Miller@courtesan.com> 34 */ 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 static char rcsid[] = "$OpenBSD: ethers.c,v 1.12 2001/06/27 00:58:54 lebel Exp $"; 38 #endif /* LIBC_SCCS and not lint */ 39 40 #include <sys/types.h> 41 #include <sys/socket.h> 42 #include <net/if.h> 43 #include <netinet/in.h> 44 #include <netinet/if_ether.h> 45 #include <sys/param.h> 46 #include <paths.h> 47 #include <errno.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <ctype.h> 52 #ifdef YP 53 #include <rpcsvc/ypclnt.h> 54 #endif 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 || l < 0) 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 #ifdef YP 129 char trybuf[sizeof("xx:xx:xx:xx:xx:xx")]; 130 int trylen; 131 #endif 132 133 if (e->ether_addr_octet[0] > 0xFF || e->ether_addr_octet[1] > 0xFF || 134 e->ether_addr_octet[2] > 0xFF || e->ether_addr_octet[3] > 0xFF || 135 e->ether_addr_octet[4] > 0xFF || e->ether_addr_octet[5] > 0xFF) { 136 errno = EINVAL; 137 return (-1); 138 } 139 140 #ifdef YP 141 sprintf(trybuf, "%x:%x:%x:%x:%x:%x", 142 e->ether_addr_octet[0], e->ether_addr_octet[1], 143 e->ether_addr_octet[2], e->ether_addr_octet[3], 144 e->ether_addr_octet[4], e->ether_addr_octet[5]); 145 trylen = strlen(trybuf); 146 #endif 147 148 f = fopen(_PATH_ETHERS, "r"); 149 if (f == NULL) 150 return (-1); 151 while ((p = fgetln(f, &len)) != NULL) { 152 if (p[len-1] == '\n') 153 len--; 154 if (len > sizeof(buf) - 2) 155 continue; 156 (void)memcpy(buf, p, len); 157 buf[len] = '\n'; /* code assumes newlines later on */ 158 buf[len+1] = '\0'; 159 #ifdef YP 160 /* A + in the file means try YP now. */ 161 if (!strncmp(buf, "+\n", sizeof(buf))) { 162 char *ypbuf, *ypdom; 163 int ypbuflen; 164 165 if (yp_get_default_domain(&ypdom)) 166 continue; 167 if (yp_match(ypdom, "ethers.byaddr", trybuf, 168 trylen, &ypbuf, &ypbuflen)) 169 continue; 170 if (ether_line(ypbuf, &try, hostname) == 0) { 171 free(ypbuf); 172 (void)fclose(f); 173 return (0); 174 } 175 free(ypbuf); 176 continue; 177 } 178 #endif 179 if (ether_line(buf, &try, hostname) == 0 && 180 memcmp((void *)&try, (void *)e, sizeof(try)) == 0) { 181 (void)fclose(f); 182 return (0); 183 } 184 } 185 (void)fclose(f); 186 errno = ENOENT; 187 return (-1); 188 } 189 190 int 191 ether_hostton(hostname, e) 192 char *hostname; 193 struct ether_addr *e; 194 { 195 FILE *f; 196 char buf[BUFSIZ+1], *p; 197 char try[MAXHOSTNAMELEN]; 198 size_t len; 199 #ifdef YP 200 int hostlen = strlen(hostname); 201 #endif 202 203 f = fopen(_PATH_ETHERS, "r"); 204 if (f==NULL) 205 return (-1); 206 207 while ((p = fgetln(f, &len)) != NULL) { 208 if (p[len-1] == '\n') 209 len--; 210 if (len > sizeof(buf) - 2) 211 continue; 212 memcpy(buf, p, len); 213 buf[len] = '\n'; /* code assumes newlines later on */ 214 buf[len+1] = '\0'; 215 #ifdef YP 216 /* A + in the file means try YP now. */ 217 if (!strncmp(buf, "+\n", sizeof(buf))) { 218 char *ypbuf, *ypdom; 219 int ypbuflen; 220 221 if (yp_get_default_domain(&ypdom)) 222 continue; 223 if (yp_match(ypdom, "ethers.byname", hostname, hostlen, 224 &ypbuf, &ypbuflen)) 225 continue; 226 if (ether_line(ypbuf, e, try) == 0) { 227 free(ypbuf); 228 (void)fclose(f); 229 return (0); 230 } 231 free(ypbuf); 232 continue; 233 } 234 #endif 235 if (ether_line(buf, e, try) == 0 && strcmp(hostname, try) == 0) { 236 (void)fclose(f); 237 return (0); 238 } 239 } 240 (void)fclose(f); 241 errno = ENOENT; 242 return (-1); 243 } 244 245 int 246 ether_line(line, e, hostname) 247 char *line; 248 struct ether_addr *e; 249 char *hostname; 250 { 251 char *p; 252 size_t n; 253 254 /* Parse "xx:xx:xx:xx:xx:xx" */ 255 if ((p = _ether_aton(line, e)) == NULL || (*p != ' ' && *p != '\t')) 256 goto bad; 257 258 /* Now get the hostname */ 259 while (isspace(*p)) 260 p++; 261 if (*p == '\0') 262 goto bad; 263 n = strcspn(p, " \t\n"); 264 if (n >= MAXHOSTNAMELEN) 265 goto bad; 266 strlcpy(hostname, p, n + 1); 267 return (0); 268 269 bad: 270 errno = EINVAL; 271 return (-1); 272 } 273