| 1 | #ifndef lint |
| 2 | static char *sccsid = "@(#)arp.c 5.2 (Berkeley) %G%"; |
| 3 | #endif |
| 4 | |
| 5 | /* |
| 6 | * arp - display, set, and delete arp table entries |
| 7 | */ |
| 8 | |
| 9 | #include <stdio.h> |
| 10 | #include <sys/types.h> |
| 11 | #include <sys/socket.h> |
| 12 | #include <netinet/in.h> |
| 13 | #include <sys/ioctl.h> |
| 14 | #include <errno.h> |
| 15 | #include <netdb.h> |
| 16 | #include <nlist.h> |
| 17 | #include <net/if.h> |
| 18 | #include <netinet/if_ether.h> |
| 19 | |
| 20 | extern int errno; |
| 21 | |
| 22 | main(argc, argv) |
| 23 | char **argv; |
| 24 | { |
| 25 | if (argc >= 2 && strcmp(argv[1], "-a") == 0) { |
| 26 | char *kernel = "/vmunix", *mem = "/dev/kmem"; |
| 27 | |
| 28 | if (argc >= 3) |
| 29 | kernel = argv[2]; |
| 30 | if (argc >= 4) |
| 31 | mem = argv[3]; |
| 32 | dump(kernel, mem); |
| 33 | exit(0); |
| 34 | } |
| 35 | if (argc == 2) { |
| 36 | get(argv[1]); |
| 37 | exit(0); |
| 38 | } |
| 39 | if (argc >= 4 && strcmp(argv[1], "-s") == 0) { |
| 40 | set(argc-2, &argv[2]); |
| 41 | exit(0); |
| 42 | } |
| 43 | if (argc == 3 && strcmp(argv[1], "-d") == 0) { |
| 44 | delete(argv[2]); |
| 45 | exit(0); |
| 46 | } |
| 47 | if (argc == 3 && strcmp(argv[1], "-f") == 0) { |
| 48 | file(argv[2]); |
| 49 | exit(0); |
| 50 | } |
| 51 | usage(); |
| 52 | exit(1); |
| 53 | } |
| 54 | |
| 55 | /* |
| 56 | * Process a file to set standard arp entries |
| 57 | */ |
| 58 | file(name) |
| 59 | char *name; |
| 60 | { |
| 61 | FILE *fp; |
| 62 | int i; |
| 63 | char line[100], arg[5][50], *args[5]; |
| 64 | |
| 65 | if ((fp = fopen(name, "r")) == NULL) { |
| 66 | fprintf(stderr, "arp: cannot open %s\n", name); |
| 67 | exit(1); |
| 68 | } |
| 69 | args[0] = &arg[0][0]; |
| 70 | args[1] = &arg[1][0]; |
| 71 | args[2] = &arg[2][0]; |
| 72 | args[3] = &arg[3][0]; |
| 73 | args[4] = &arg[4][0]; |
| 74 | while(fgets(line, 100, fp) != NULL) { |
| 75 | i = sscanf(line, "%s %s %s %s", arg[0], arg[1], arg[2], arg[3], |
| 76 | arg[4]); |
| 77 | if (i < 2) { |
| 78 | fprintf(stderr, "arp: bad line: %s\n", line); |
| 79 | continue; |
| 80 | } |
| 81 | set(i, args); |
| 82 | } |
| 83 | fclose(fp); |
| 84 | } |
| 85 | |
| 86 | /* |
| 87 | * Set an individual arp entry |
| 88 | */ |
| 89 | set(argc, argv) |
| 90 | char **argv; |
| 91 | { |
| 92 | struct arpreq ar; |
| 93 | struct hostent *hp; |
| 94 | struct sockaddr_in *sin; |
| 95 | u_char *ea; |
| 96 | int s; |
| 97 | char *host = argv[0], *eaddr = argv[1]; |
| 98 | |
| 99 | argc -= 2; |
| 100 | argv += 2; |
| 101 | bzero((caddr_t)&ar, sizeof ar); |
| 102 | sin = (struct sockaddr_in *)&ar.arp_pa; |
| 103 | sin->sin_family = AF_INET; |
| 104 | sin->sin_addr.s_addr = inet_addr(host); |
| 105 | if (sin->sin_addr.s_addr == -1) { |
| 106 | hp = gethostbyname(host); |
| 107 | if (hp == NULL) { |
| 108 | fprintf(stderr, "arp: %s: unknown host\n", host); |
| 109 | return; |
| 110 | } |
| 111 | bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, |
| 112 | sizeof sin->sin_addr); |
| 113 | } |
| 114 | ea = (u_char *)ar.arp_ha.sa_data; |
| 115 | if (ether_aton(eaddr, ea)) |
| 116 | return; |
| 117 | ar.arp_flags = ATF_PERM; |
| 118 | while (argc-- > 0) { |
| 119 | if (strncmp(argv[0], "temp", 4) == 0) |
| 120 | ar.arp_flags &= ~ATF_PERM; |
| 121 | if (strncmp(argv[0], "pub", 3) == 0) |
| 122 | ar.arp_flags |= ATF_PUBL; |
| 123 | if (strncmp(argv[0], "trail", 5) == 0) |
| 124 | ar.arp_flags |= ATF_USETRAILERS; |
| 125 | argv++; |
| 126 | } |
| 127 | |
| 128 | s = socket(AF_INET, SOCK_DGRAM, 0); |
| 129 | if (s < 0) { |
| 130 | perror("arp: socket"); |
| 131 | exit(1); |
| 132 | } |
| 133 | if (ioctl(s, SIOCSARP, (caddr_t)&ar) < 0) { |
| 134 | perror(host); |
| 135 | exit(1); |
| 136 | } |
| 137 | close(s); |
| 138 | } |
| 139 | |
| 140 | |
| 141 | /* |
| 142 | * Display an individual arp entry |
| 143 | */ |
| 144 | get(host) |
| 145 | char *host; |
| 146 | { |
| 147 | struct arpreq ar; |
| 148 | struct hostent *hp; |
| 149 | struct sockaddr_in *sin; |
| 150 | u_char *ea; |
| 151 | int s; |
| 152 | |
| 153 | bzero((caddr_t)&ar, sizeof ar); |
| 154 | ar.arp_pa.sa_family = AF_INET; |
| 155 | sin = (struct sockaddr_in *)&ar.arp_pa; |
| 156 | sin->sin_family = AF_INET; |
| 157 | sin->sin_addr.s_addr = inet_addr(host); |
| 158 | if (sin->sin_addr.s_addr == -1) { |
| 159 | hp = gethostbyname(host); |
| 160 | if (hp == NULL) { |
| 161 | fprintf(stderr, "arp: %s: unknown host\n", host); |
| 162 | exit(1); |
| 163 | } |
| 164 | bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, |
| 165 | sizeof sin->sin_addr); |
| 166 | } |
| 167 | s = socket(AF_INET, SOCK_DGRAM, 0); |
| 168 | if (s < 0) { |
| 169 | perror("arp: socket"); |
| 170 | exit(1); |
| 171 | } |
| 172 | if (ioctl(s, SIOCGARP, (caddr_t)&ar) < 0) { |
| 173 | if (errno == ENXIO) |
| 174 | printf("%s (%s) -- no entry\n", |
| 175 | host, inet_ntoa(sin->sin_addr)); |
| 176 | else |
| 177 | perror("SIOCGARP"); |
| 178 | exit(1); |
| 179 | } |
| 180 | close(s); |
| 181 | ea = (u_char *)ar.arp_ha.sa_data; |
| 182 | printf("%s (%s) at ", host, inet_ntoa(sin->sin_addr)); |
| 183 | if (ar.arp_flags & ATF_COM) |
| 184 | ether_print(ea); |
| 185 | else |
| 186 | printf("(incomplete)"); |
| 187 | if (ar.arp_flags & ATF_PERM) printf(" permanent"); |
| 188 | if (ar.arp_flags & ATF_PUBL) printf(" published"); |
| 189 | if (ar.arp_flags & ATF_USETRAILERS) printf(" trailers"); |
| 190 | printf("\n"); |
| 191 | } |
| 192 | |
| 193 | /* |
| 194 | * Delete an arp entry |
| 195 | */ |
| 196 | delete(host) |
| 197 | char *host; |
| 198 | { |
| 199 | struct arpreq ar; |
| 200 | struct hostent *hp; |
| 201 | struct sockaddr_in *sin; |
| 202 | int s; |
| 203 | |
| 204 | bzero((caddr_t)&ar, sizeof ar); |
| 205 | ar.arp_pa.sa_family = AF_INET; |
| 206 | sin = (struct sockaddr_in *)&ar.arp_pa; |
| 207 | sin->sin_family = AF_INET; |
| 208 | sin->sin_addr.s_addr = inet_addr(host); |
| 209 | if (sin->sin_addr.s_addr == -1) { |
| 210 | hp = gethostbyname(host); |
| 211 | if (hp == NULL) { |
| 212 | fprintf(stderr, "arp: %s: unknown host\n", host); |
| 213 | exit(1); |
| 214 | } |
| 215 | bcopy((char *)hp->h_addr, (char *)&sin->sin_addr, |
| 216 | sizeof sin->sin_addr); |
| 217 | } |
| 218 | s = socket(AF_INET, SOCK_DGRAM, 0); |
| 219 | if (s < 0) { |
| 220 | perror("arp: socket"); |
| 221 | exit(1); |
| 222 | } |
| 223 | if (ioctl(s, SIOCDARP, (caddr_t)&ar) < 0) { |
| 224 | if (errno == ENXIO) |
| 225 | printf("%s (%s) -- no entry\n", |
| 226 | host, inet_ntoa(sin->sin_addr)); |
| 227 | else |
| 228 | perror("SIOCDARP"); |
| 229 | exit(1); |
| 230 | } |
| 231 | close(s); |
| 232 | printf("%s (%s) deleted\n", host, inet_ntoa(sin->sin_addr)); |
| 233 | } |
| 234 | |
| 235 | struct nlist nl[] = { |
| 236 | #define X_ARPTAB 0 |
| 237 | { "_arptab" }, |
| 238 | #define X_ARPTAB_SIZE 1 |
| 239 | { "_arptab_size" }, |
| 240 | { "" }, |
| 241 | }; |
| 242 | |
| 243 | /* |
| 244 | * Dump the entire arp table |
| 245 | */ |
| 246 | dump(kernel, mem) |
| 247 | char *kernel, *mem; |
| 248 | { |
| 249 | int mf, arptab_size, sz; |
| 250 | struct arptab *at; |
| 251 | struct hostent *hp; |
| 252 | char *host; |
| 253 | int bynumber = 0; |
| 254 | |
| 255 | nlist(kernel, nl); |
| 256 | if(nl[X_ARPTAB_SIZE].n_type == 0) { |
| 257 | fprintf(stderr, "arp: %s: bad namelist\n", kernel); |
| 258 | exit(1); |
| 259 | } |
| 260 | mf = open(mem, 0); |
| 261 | if(mf < 0) { |
| 262 | fprintf(fprintf, "arp: cannot open %s\n", mem); |
| 263 | exit(1); |
| 264 | } |
| 265 | lseek(mf, (long)nl[X_ARPTAB_SIZE].n_value, 0); |
| 266 | read(mf, &arptab_size, sizeof arptab_size); |
| 267 | if (arptab_size <=0 || arptab_size > 1000) { |
| 268 | fprintf(stderr, "arp: %s: namelist wrong\n", kernel); |
| 269 | exit(1); |
| 270 | } |
| 271 | sz = arptab_size * sizeof (struct arptab); |
| 272 | at = (struct arptab *)malloc(sz); |
| 273 | if (at == NULL) { |
| 274 | fprintf(stderr, "arp: can't get memory for arptab\n"); |
| 275 | exit(1); |
| 276 | } |
| 277 | lseek(mf, (long)nl[X_ARPTAB].n_value, 0); |
| 278 | if (read(mf, (char *)at, sz) != sz) { |
| 279 | perror("arp: error reading arptab"); |
| 280 | exit(1); |
| 281 | } |
| 282 | close(mf); |
| 283 | for (; arptab_size-- > 0; at++) { |
| 284 | if (at->at_iaddr.s_addr == 0 || at->at_flags == 0) |
| 285 | continue; |
| 286 | if (bynumber == 0) |
| 287 | hp = gethostbyaddr((caddr_t)&at->at_iaddr, |
| 288 | sizeof at->at_iaddr, AF_INET); |
| 289 | else |
| 290 | hp = 0; |
| 291 | if (hp) |
| 292 | host = hp->h_name; |
| 293 | else { |
| 294 | host = "?"; |
| 295 | if (h_errno == TRY_AGAIN) |
| 296 | bynumber = 1; |
| 297 | } |
| 298 | printf("%s (%s) at ", host, inet_ntoa(at->at_iaddr)); |
| 299 | if (at->at_flags & ATF_COM) |
| 300 | ether_print(at->at_enaddr); |
| 301 | else |
| 302 | printf("(incomplete)"); |
| 303 | if (at->at_flags & ATF_PERM) printf(" permanent"); |
| 304 | if (at->at_flags & ATF_PUBL) printf(" published"); |
| 305 | if (at->at_flags & ATF_USETRAILERS) printf(" trailers"); |
| 306 | printf("\n"); |
| 307 | } |
| 308 | } |
| 309 | |
| 310 | ether_print(cp) |
| 311 | u_char *cp; |
| 312 | { |
| 313 | printf("%x:%x:%x:%x:%x:%x", cp[0], cp[1], cp[2], cp[3], cp[4], cp[5]); |
| 314 | } |
| 315 | |
| 316 | ether_aton(a, n) |
| 317 | char *a; |
| 318 | u_char *n; |
| 319 | { |
| 320 | int i, o[6]; |
| 321 | |
| 322 | i = sscanf(a, "%x:%x:%x:%x:%x:%x", &o[0], &o[1], &o[2], |
| 323 | &o[3], &o[4], &o[5]); |
| 324 | if (i != 6) { |
| 325 | fprintf(stderr, "arp: invalid Ethernet address '%s'\n", a); |
| 326 | return (1); |
| 327 | } |
| 328 | for (i=0; i<6; i++) |
| 329 | n[i] = o[i]; |
| 330 | return (0); |
| 331 | } |
| 332 | |
| 333 | usage() |
| 334 | { |
| 335 | printf("Usage: arp hostname\n"); |
| 336 | printf(" arp -a [/vmunix] [/dev/kmem]\n"); |
| 337 | printf(" arp -d hostname\n"); |
| 338 | printf(" arp -s hostname ether_addr [temp] [pub]\n"); |
| 339 | printf(" arp -f filename\n"); |
| 340 | } |