arp.c revision 1.4
1 /* 2 * Copyright (c) 1984 Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Sun Microsystems, Inc. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 char copyright[] = 39 "@(#) Copyright (c) 1984 Regents of the University of California.\n\ 40 All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 /*static char sccsid[] = "from: @(#)arp.c 5.11.1.1 (Berkeley) 7/22/91";*/ 45 static char rcsid[] = "$Id: arp.c,v 1.4 1993/12/25 02:28:46 deraadt Exp $"; 46 #endif /* not lint */ 47 48 /* 49 * arp - display, set, and delete arp table entries 50 */ 51 52 #include <sys/param.h> 53 #include <sys/file.h> 54 #include <sys/socket.h> 55 #include <sys/ioctl.h> 56 57 #include <netdb.h> 58 #include <netinet/in.h> 59 #include <net/if.h> 60 #include <netinet/if_ether.h> 61 #include <arpa/inet.h> 62 63 #include <errno.h> 64 #include <nlist.h> 65 #include <kvm.h> 66 #include <stdio.h> 67 #include <paths.h> 68 69 extern int errno; 70 71 main(argc, argv) 72 int argc; 73 char **argv; 74 { 75 int ch; 76 77 while ((ch = getopt(argc, argv, "adsf")) != EOF) 78 switch((char)ch) { 79 case 'a': { 80 char *mem = 0; 81 82 if (argc > 4) 83 usage(); 84 if (argc == 4) { 85 mem = argv[3]; 86 } 87 dump((argc >= 3) ? argv[2] : _PATH_UNIX, mem); 88 exit(0); 89 } 90 case 'd': 91 if (argc != 3) 92 usage(); 93 delete(argv[2]); 94 exit(0); 95 case 's': 96 if (argc < 4 || argc > 7) 97 usage(); 98 exit(set(argc-2, &argv[2]) ? 1 : 0); 99 case 'f': 100 if (argc != 3) 101 usage(); 102 exit (file(argv[2]) ? 1 : 0); 103 case '?': 104 default: 105 usage(); 106 } 107 if (argc != 2) 108 usage(); 109 get(argv[1]); 110 exit(0); 111 } 112 113 /* 114 * Process a file to set standard arp entries 115 */ 116 file(name) 117 char *name; 118 { 119 FILE *fp; 120 int i, retval; 121 char line[100], arg[5][50], *args[5]; 122 123 setregid(getegid(), getgid()); 124 if ((fp = fopen(name, "r")) == NULL) { 125 fprintf(stderr, "arp: cannot open %s\n", name); 126 exit(1); 127 } 128 setregid(getegid(), getgid()); 129 args[0] = &arg[0][0]; 130 args[1] = &arg[1][0]; 131 args[2] = &arg[2][0]; 132 args[3] = &arg[3][0]; 133 args[4] = &arg[4][0]; 134 retval = 0; 135 while(fgets(line, 100, fp) != NULL) { 136 i = sscanf(line, "%s %s %s %s %s", arg[0], arg[1], arg[2], 137 arg[3], arg[4]); 138 if (i < 2) { 139 fprintf(stderr, "arp: bad line: %s\n", line); 140 retval = 1; 141 continue; 142 } 143 if (set(i, args)) 144 retval = 1; 145 } 146 fclose(fp); 147 return (retval); 148 } 149 150 /* 151 * Set an individual arp entry 152 */ 153 set(argc, argv) 154 int argc; 155 char **argv; 156 { 157 struct arpreq ar; 158 struct hostent *hp; 159 struct sockaddr_in *sin; 160 u_char *ea; 161 int s; 162 char *host = argv[0], *eaddr = argv[1]; 163 164 argc -= 2; 165 argv += 2; 166 bzero((caddr_t)&ar, sizeof ar); 167 sin = (struct sockaddr_in *)&ar.arp_pa; 168 sin->sin_family = AF_INET; 169 sin->sin_addr.s_addr = inet_addr(host); 170 if (sin->sin_addr.s_addr == -1) { 171 if (!(hp = gethostbyname(host))) { 172 fprintf(stderr, "arp: %s: ", host); 173 herror((char *)NULL); 174 return (1); 175 } 176 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, 177 sizeof sin->sin_addr); 178 } 179 ea = (u_char *)ar.arp_ha.sa_data; 180 if (ether_aton(eaddr, ea)) 181 return (1); 182 ar.arp_flags = ATF_PERM; 183 while (argc-- > 0) { 184 if (strncmp(argv[0], "temp", 4) == 0) 185 ar.arp_flags &= ~ATF_PERM; 186 else if (strncmp(argv[0], "pub", 3) == 0) 187 ar.arp_flags |= ATF_PUBL; 188 else if (strncmp(argv[0], "trail", 5) == 0) 189 ar.arp_flags |= ATF_USETRAILERS; 190 argv++; 191 } 192 193 s = socket(AF_INET, SOCK_DGRAM, 0); 194 if (s < 0) { 195 perror("arp: socket"); 196 exit(1); 197 } 198 if (ioctl(s, SIOCSARP, (caddr_t)&ar) < 0) { 199 perror(host); 200 exit(1); 201 } 202 close(s); 203 return (0); 204 } 205 206 /* 207 * Display an individual arp entry 208 */ 209 get(host) 210 char *host; 211 { 212 struct arpreq ar; 213 struct hostent *hp; 214 struct sockaddr_in *sin; 215 u_char *ea; 216 int s; 217 218 bzero((caddr_t)&ar, sizeof ar); 219 ar.arp_pa.sa_family = AF_INET; 220 sin = (struct sockaddr_in *)&ar.arp_pa; 221 sin->sin_family = AF_INET; 222 sin->sin_addr.s_addr = inet_addr(host); 223 if (sin->sin_addr.s_addr == -1) { 224 if (!(hp = gethostbyname(host))) { 225 fprintf(stderr, "arp: %s: ", host); 226 herror((char *)NULL); 227 exit(1); 228 } 229 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, 230 sizeof sin->sin_addr); 231 } 232 s = socket(AF_INET, SOCK_DGRAM, 0); 233 if (s < 0) { 234 perror("arp: socket"); 235 exit(1); 236 } 237 if (ioctl(s, SIOCGARP, (caddr_t)&ar) < 0) { 238 if (errno == ENXIO) 239 printf("%s (%s) -- no entry\n", 240 host, inet_ntoa(sin->sin_addr)); 241 else 242 perror("SIOCGARP"); 243 exit(1); 244 } 245 close(s); 246 ea = (u_char *)ar.arp_ha.sa_data; 247 printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr)); 248 if (ar.arp_flags & ATF_COM) 249 ether_print(ea); 250 else 251 printf("(incomplete)"); 252 if (ar.arp_flags & ATF_PERM) 253 printf(" permanent"); 254 if (ar.arp_flags & ATF_PUBL) 255 printf(" published"); 256 if (ar.arp_flags & ATF_USETRAILERS) 257 printf(" trailers"); 258 printf("\n"); 259 } 260 261 /* 262 * Delete an arp entry 263 */ 264 delete(host) 265 char *host; 266 { 267 struct arpreq ar; 268 struct hostent *hp; 269 struct sockaddr_in *sin; 270 int s; 271 272 bzero((caddr_t)&ar, sizeof ar); 273 ar.arp_pa.sa_family = AF_INET; 274 sin = (struct sockaddr_in *)&ar.arp_pa; 275 sin->sin_family = AF_INET; 276 sin->sin_addr.s_addr = inet_addr(host); 277 if (sin->sin_addr.s_addr == -1) { 278 if (!(hp = gethostbyname(host))) { 279 fprintf(stderr, "arp: %s: ", host); 280 herror((char *)NULL); 281 exit(1); 282 } 283 bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, 284 sizeof sin->sin_addr); 285 } 286 s = socket(AF_INET, SOCK_DGRAM, 0); 287 if (s < 0) { 288 perror("arp: socket"); 289 exit(1); 290 } 291 if (ioctl(s, SIOCDARP, (caddr_t)&ar) < 0) { 292 if (errno == ENXIO) 293 printf("%s (%s) -- no entry\n", 294 host, inet_ntoa(sin->sin_addr)); 295 else 296 perror("SIOCDARP"); 297 exit(1); 298 } 299 close(s); 300 printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr)); 301 } 302 303 struct nlist nl[] = { 304 #define X_ARPTAB 0 305 { "_arptab" }, 306 #define X_ARPTAB_SIZE 1 307 { "_arptab_size" }, 308 { "" }, 309 }; 310 311 /* 312 * Dump the entire arp table 313 */ 314 dump(kernel, mem) 315 char *kernel, *mem; 316 { 317 extern int h_errno; 318 struct arptab *at; 319 struct hostent *hp; 320 int bynumber, mf, arptab_size, sz; 321 char *host, *malloc(); 322 off_t lseek(); 323 324 if (kvm_openfiles(kernel, mem, NULL) == -1) { 325 fprintf(stderr, "arp: kvm_openfiles: %s\n", kvm_geterr()); 326 exit(1); 327 } 328 if (kvm_nlist(nl) < 0 || nl[X_ARPTAB_SIZE].n_type == 0) { 329 fprintf(stderr, "arp: %s: bad namelist\n", kernel); 330 exit(1); 331 } 332 if (kvm_read((void *)(nl[X_ARPTAB_SIZE].n_value), 333 &arptab_size, sizeof arptab_size) == -1 || 334 arptab_size <= 0 || arptab_size > 1000) { 335 fprintf(stderr, "arp: %s: namelist wrong\n", kernel); 336 exit(1); 337 } 338 sz = arptab_size * sizeof (struct arptab); 339 at = (struct arptab *)malloc((u_int)sz); 340 if (at == NULL) { 341 fputs("arp: can't get memory for arptab.\n", stderr); 342 exit(1); 343 } 344 if (kvm_read((void *)(nl[X_ARPTAB].n_value), (char *)at, sz) == -1) { 345 perror("arp: error reading arptab"); 346 exit(1); 347 } 348 for (bynumber = 0; arptab_size-- > 0; at++) { 349 if (at->at_iaddr.s_addr == 0 || at->at_flags == 0) 350 continue; 351 if (bynumber == 0) 352 hp = gethostbyaddr((caddr_t)&at->at_iaddr, 353 sizeof at->at_iaddr, AF_INET); 354 else 355 hp = 0; 356 if (hp) 357 host = hp->h_name; 358 else { 359 host = "?"; 360 if (h_errno == TRY_AGAIN) 361 bynumber = 1; 362 } 363 printf("%s (%s) at ", host, inet_ntoa(at->at_iaddr)); 364 if (at->at_flags & ATF_COM) 365 ether_print(at->at_enaddr); 366 else 367 printf("(incomplete)"); 368 if (at->at_flags & ATF_PERM) 369 printf(" permanent"); 370 if (at->at_flags & ATF_PUBL) 371 printf(" published"); 372 if (at->at_flags & ATF_USETRAILERS) 373 printf(" trailers"); 374 printf("\n"); 375 } 376 } 377 378 ether_print(cp) 379 u_char *cp; 380 { 381 printf("%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]); 382 } 383 384 ether_aton(a, n) 385 char *a; 386 u_char *n; 387 { 388 int i, o[6]; 389 390 i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o[0], &o[1], &o[2], 391 &o[3], &o[4], &o[5]); 392 if (i != 6) { 393 fprintf(stderr, "arp: invalid Ethernet address '%s'\n", a); 394 return (1); 395 } 396 for (i=0; i<6; i++) 397 n[i] = o[i]; 398 return (0); 399 } 400 401 usage() 402 { 403 printf("usage: arp hostname\n"); 404 printf(" arp -a [kernel] [kernel_memory]\n"); 405 printf(" arp -d hostname\n"); 406 printf(" arp -s hostname ether_addr [temp] [pub] [trail]\n"); 407 printf(" arp -f filename\n"); 408 exit(1); 409 } 410
Indexes created Tue Sep 30 20:09:53 GMT 2025