Lorenzo Colitti | 313379e | 2013-07-11 01:07:11 +0900 | [diff] [blame] | 1 | /* |
| 2 | * arping.c |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| 10 | * YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> |
| 11 | */ |
| 12 | |
| 13 | #include <stdlib.h> |
| 14 | #include <sys/param.h> |
| 15 | #include <sys/socket.h> |
| 16 | #include <linux/sockios.h> |
| 17 | #include <sys/file.h> |
| 18 | #include <sys/time.h> |
| 19 | #include <sys/signal.h> |
| 20 | #include <sys/ioctl.h> |
| 21 | #include <net/if.h> |
| 22 | #include <linux/if_packet.h> |
| 23 | #include <linux/if_ether.h> |
| 24 | #include <net/if_arp.h> |
| 25 | #include <sys/uio.h> |
| 26 | #ifdef CAPABILITIES |
| 27 | #include <sys/prctl.h> |
| 28 | #include <sys/capability.h> |
| 29 | #endif |
| 30 | |
| 31 | #include <netdb.h> |
| 32 | #include <unistd.h> |
| 33 | #include <stdio.h> |
| 34 | #include <ctype.h> |
| 35 | #include <errno.h> |
| 36 | #include <string.h> |
| 37 | #include <netinet/in.h> |
| 38 | #include <arpa/inet.h> |
| 39 | |
| 40 | #ifdef USE_SYSFS |
| 41 | #include <sysfs/libsysfs.h> |
| 42 | struct sysfs_devattr_values; |
| 43 | #endif |
| 44 | |
| 45 | #ifndef WITHOUT_IFADDRS |
| 46 | #include <ifaddrs.h> |
| 47 | #endif |
| 48 | |
| 49 | #ifdef USE_IDN |
| 50 | #include <idna.h> |
| 51 | #include <locale.h> |
| 52 | #endif |
| 53 | |
| 54 | #include "SNAPSHOT.h" |
| 55 | |
| 56 | static void usage(void) __attribute__((noreturn)); |
| 57 | |
| 58 | #ifdef DEFAULT_DEVICE |
| 59 | # define DEFAULT_DEVICE_STR DEFAULT_DEVICE |
| 60 | #else |
| 61 | # define DEFAULT_DEVICE NULL |
| 62 | #endif |
| 63 | |
| 64 | struct device { |
| 65 | char *name; |
| 66 | int ifindex; |
| 67 | #ifndef WITHOUT_IFADDRS |
| 68 | struct ifaddrs *ifa; |
| 69 | #endif |
| 70 | #ifdef USE_SYSFS |
| 71 | struct sysfs_devattr_values *sysfs; |
| 72 | #endif |
| 73 | }; |
| 74 | |
| 75 | int quit_on_reply=0; |
| 76 | struct device device = { |
| 77 | .name = DEFAULT_DEVICE, |
| 78 | }; |
| 79 | char *source; |
| 80 | struct in_addr src, dst; |
| 81 | char *target; |
| 82 | int dad, unsolicited, advert; |
| 83 | int quiet; |
| 84 | int count=-1; |
| 85 | int timeout; |
| 86 | int unicasting; |
| 87 | int s; |
| 88 | int broadcast_only; |
| 89 | |
| 90 | struct sockaddr_storage me; |
| 91 | struct sockaddr_storage he; |
| 92 | |
| 93 | struct timeval start, last; |
| 94 | |
| 95 | int sent, brd_sent; |
| 96 | int received, brd_recv, req_recv; |
| 97 | |
| 98 | #ifndef CAPABILITIES |
| 99 | static uid_t euid; |
| 100 | #endif |
| 101 | |
| 102 | #define MS_TDIFF(tv1,tv2) ( ((tv1).tv_sec-(tv2).tv_sec)*1000 + \ |
| 103 | ((tv1).tv_usec-(tv2).tv_usec)/1000 ) |
| 104 | |
| 105 | #define OFFSET_OF(name,ele) ((size_t)(((name *)0)->ele)) |
| 106 | |
| 107 | static inline socklen_t sll_len(size_t halen) |
| 108 | { |
| 109 | socklen_t len = OFFSET_OF(struct sockaddr_ll, sll_addr) + halen; |
| 110 | if (len < sizeof(struct sockaddr_ll)) |
| 111 | len = sizeof(struct sockaddr_ll); |
| 112 | return len; |
| 113 | } |
| 114 | |
| 115 | #define SLL_LEN(hln) sll_len(hln) |
| 116 | |
| 117 | void usage(void) |
| 118 | { |
| 119 | fprintf(stderr, |
| 120 | "Usage: arping [-fqbDUAV] [-c count] [-w timeout] [-I device] [-s source] destination\n" |
| 121 | " -f : quit on first reply\n" |
| 122 | " -q : be quiet\n" |
| 123 | " -b : keep broadcasting, don't go unicast\n" |
| 124 | " -D : duplicate address detection mode\n" |
| 125 | " -U : Unsolicited ARP mode, update your neighbours\n" |
| 126 | " -A : ARP answer mode, update your neighbours\n" |
| 127 | " -V : print version and exit\n" |
| 128 | " -c count : how many packets to send\n" |
| 129 | " -w timeout : how long to wait for a reply\n" |
| 130 | " -I device : which ethernet device to use" |
| 131 | #ifdef DEFAULT_DEVICE_STR |
| 132 | " (" DEFAULT_DEVICE_STR ")" |
| 133 | #endif |
| 134 | "\n" |
| 135 | " -s source : source ip address\n" |
| 136 | " destination : ask for what ip address\n" |
| 137 | ); |
| 138 | exit(2); |
| 139 | } |
| 140 | |
| 141 | void set_signal(int signo, void (*handler)(void)) |
| 142 | { |
| 143 | struct sigaction sa; |
| 144 | |
| 145 | memset(&sa, 0, sizeof(sa)); |
| 146 | sa.sa_handler = (void (*)(int))handler; |
| 147 | sa.sa_flags = SA_RESTART; |
| 148 | sigaction(signo, &sa, NULL); |
| 149 | } |
| 150 | |
| 151 | #ifdef CAPABILITIES |
| 152 | static const cap_value_t caps[] = { CAP_NET_RAW, }; |
| 153 | static cap_flag_value_t cap_raw = CAP_CLEAR; |
| 154 | #endif |
| 155 | |
| 156 | void limit_capabilities(void) |
| 157 | { |
| 158 | #ifdef CAPABILITIES |
| 159 | cap_t cap_p; |
| 160 | |
| 161 | cap_p = cap_get_proc(); |
| 162 | if (!cap_p) { |
| 163 | perror("arping: cap_get_proc"); |
| 164 | exit(-1); |
| 165 | } |
| 166 | |
| 167 | cap_get_flag(cap_p, CAP_NET_RAW, CAP_PERMITTED, &cap_raw); |
| 168 | |
| 169 | if (cap_raw != CAP_CLEAR) { |
| 170 | if (cap_clear(cap_p) < 0) { |
| 171 | perror("arping: cap_clear"); |
| 172 | exit(-1); |
| 173 | } |
| 174 | |
| 175 | cap_set_flag(cap_p, CAP_PERMITTED, 1, caps, CAP_SET); |
| 176 | |
| 177 | if (cap_set_proc(cap_p) < 0) { |
| 178 | perror("arping: cap_set_proc"); |
| 179 | if (errno != EPERM) |
| 180 | exit(-1); |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | if (prctl(PR_SET_KEEPCAPS, 1) < 0) { |
| 185 | perror("arping: prctl"); |
| 186 | exit(-1); |
| 187 | } |
| 188 | |
| 189 | if (setuid(getuid()) < 0) { |
| 190 | perror("arping: setuid"); |
| 191 | exit(-1); |
| 192 | } |
| 193 | |
| 194 | if (prctl(PR_SET_KEEPCAPS, 0) < 0) { |
| 195 | perror("arping: prctl"); |
| 196 | exit(-1); |
| 197 | } |
| 198 | |
| 199 | cap_free(cap_p); |
| 200 | #else |
| 201 | euid = geteuid(); |
| 202 | #endif |
| 203 | } |
| 204 | |
| 205 | int modify_capability_raw(int on) |
| 206 | { |
| 207 | #ifdef CAPABILITIES |
| 208 | cap_t cap_p; |
| 209 | |
| 210 | if (cap_raw != CAP_SET) |
| 211 | return on ? -1 : 0; |
| 212 | |
| 213 | cap_p = cap_get_proc(); |
| 214 | if (!cap_p) { |
| 215 | perror("arping: cap_get_proc"); |
| 216 | return -1; |
| 217 | } |
| 218 | |
| 219 | cap_set_flag(cap_p, CAP_EFFECTIVE, 1, caps, on ? CAP_SET : CAP_CLEAR); |
| 220 | |
| 221 | if (cap_set_proc(cap_p) < 0) { |
| 222 | perror("arping: cap_set_proc"); |
| 223 | return -1; |
| 224 | } |
| 225 | |
| 226 | cap_free(cap_p); |
| 227 | #else |
| 228 | if (setuid(on ? euid : getuid())) { |
| 229 | perror("arping: setuid"); |
| 230 | return -1; |
| 231 | } |
| 232 | #endif |
| 233 | return 0; |
| 234 | } |
| 235 | |
| 236 | static inline int enable_capability_raw(void) |
| 237 | { |
| 238 | return modify_capability_raw(1); |
| 239 | } |
| 240 | |
| 241 | static inline int disable_capability_raw(void) |
| 242 | { |
| 243 | return modify_capability_raw(0); |
| 244 | } |
| 245 | |
| 246 | void drop_capabilities(void) |
| 247 | { |
| 248 | #ifdef CAPABILITIES |
| 249 | cap_t cap_p = cap_init(); |
| 250 | |
| 251 | if (!cap_p) { |
| 252 | perror("arping: cap_init"); |
| 253 | exit(-1); |
| 254 | } |
| 255 | |
| 256 | if (cap_set_proc(cap_p) < 0) { |
| 257 | perror("arping: cap_set_proc"); |
| 258 | exit(-1); |
| 259 | } |
| 260 | |
| 261 | cap_free(cap_p); |
| 262 | #else |
| 263 | if (setuid(getuid()) < 0) { |
| 264 | perror("arping: setuid"); |
| 265 | exit(-1); |
| 266 | } |
| 267 | #endif |
| 268 | } |
| 269 | |
| 270 | int send_pack(int s, struct in_addr src, struct in_addr dst, |
| 271 | struct sockaddr_ll *ME, struct sockaddr_ll *HE) |
| 272 | { |
| 273 | int err; |
| 274 | struct timeval now; |
| 275 | unsigned char buf[256]; |
| 276 | struct arphdr *ah = (struct arphdr*)buf; |
| 277 | unsigned char *p = (unsigned char *)(ah+1); |
| 278 | |
| 279 | ah->ar_hrd = htons(ME->sll_hatype); |
| 280 | if (ah->ar_hrd == htons(ARPHRD_FDDI)) |
| 281 | ah->ar_hrd = htons(ARPHRD_ETHER); |
| 282 | ah->ar_pro = htons(ETH_P_IP); |
| 283 | ah->ar_hln = ME->sll_halen; |
| 284 | ah->ar_pln = 4; |
| 285 | ah->ar_op = advert ? htons(ARPOP_REPLY) : htons(ARPOP_REQUEST); |
| 286 | |
| 287 | memcpy(p, &ME->sll_addr, ah->ar_hln); |
| 288 | p+=ME->sll_halen; |
| 289 | |
| 290 | memcpy(p, &src, 4); |
| 291 | p+=4; |
| 292 | |
| 293 | if (advert) |
| 294 | memcpy(p, &ME->sll_addr, ah->ar_hln); |
| 295 | else |
| 296 | memcpy(p, &HE->sll_addr, ah->ar_hln); |
| 297 | p+=ah->ar_hln; |
| 298 | |
| 299 | memcpy(p, &dst, 4); |
| 300 | p+=4; |
| 301 | |
| 302 | gettimeofday(&now, NULL); |
| 303 | err = sendto(s, buf, p-buf, 0, (struct sockaddr*)HE, SLL_LEN(ah->ar_hln)); |
| 304 | if (err == p-buf) { |
| 305 | last = now; |
| 306 | sent++; |
| 307 | if (!unicasting) |
| 308 | brd_sent++; |
| 309 | } |
| 310 | return err; |
| 311 | } |
| 312 | |
| 313 | void finish(void) |
| 314 | { |
| 315 | if (!quiet) { |
| 316 | printf("Sent %d probes (%d broadcast(s))\n", sent, brd_sent); |
| 317 | printf("Received %d response(s)", received); |
| 318 | if (brd_recv || req_recv) { |
| 319 | printf(" ("); |
| 320 | if (req_recv) |
| 321 | printf("%d request(s)", req_recv); |
| 322 | if (brd_recv) |
| 323 | printf("%s%d broadcast(s)", |
| 324 | req_recv ? ", " : "", |
| 325 | brd_recv); |
| 326 | printf(")"); |
| 327 | } |
| 328 | printf("\n"); |
| 329 | fflush(stdout); |
| 330 | } |
| 331 | if (dad) |
| 332 | exit(!!received); |
| 333 | if (unsolicited) |
| 334 | exit(0); |
| 335 | exit(!received); |
| 336 | } |
| 337 | |
| 338 | void catcher(void) |
| 339 | { |
| 340 | struct timeval tv, tv_s, tv_o; |
| 341 | |
| 342 | gettimeofday(&tv, NULL); |
| 343 | |
| 344 | if (start.tv_sec==0) |
| 345 | start = tv; |
| 346 | |
| 347 | timersub(&tv, &start, &tv_s); |
| 348 | tv_o.tv_sec = timeout; |
| 349 | tv_o.tv_usec = 500 * 1000; |
| 350 | |
| 351 | if (count-- == 0 || (timeout && timercmp(&tv_s, &tv_o, >))) |
| 352 | finish(); |
| 353 | |
| 354 | timersub(&tv, &last, &tv_s); |
| 355 | tv_o.tv_sec = 0; |
| 356 | |
| 357 | if (last.tv_sec==0 || timercmp(&tv_s, &tv_o, >)) { |
| 358 | send_pack(s, src, dst, |
| 359 | (struct sockaddr_ll *)&me, (struct sockaddr_ll *)&he); |
| 360 | if (count == 0 && unsolicited) |
| 361 | finish(); |
| 362 | } |
| 363 | alarm(1); |
| 364 | } |
| 365 | |
| 366 | void print_hex(unsigned char *p, int len) |
| 367 | { |
| 368 | int i; |
| 369 | for (i=0; i<len; i++) { |
| 370 | printf("%02X", p[i]); |
| 371 | if (i != len-1) |
| 372 | printf(":"); |
| 373 | } |
| 374 | } |
| 375 | |
| 376 | int recv_pack(unsigned char *buf, int len, struct sockaddr_ll *FROM) |
| 377 | { |
| 378 | struct timeval tv; |
| 379 | struct arphdr *ah = (struct arphdr*)buf; |
| 380 | unsigned char *p = (unsigned char *)(ah+1); |
| 381 | struct in_addr src_ip, dst_ip; |
| 382 | |
| 383 | gettimeofday(&tv, NULL); |
| 384 | |
| 385 | /* Filter out wild packets */ |
| 386 | if (FROM->sll_pkttype != PACKET_HOST && |
| 387 | FROM->sll_pkttype != PACKET_BROADCAST && |
| 388 | FROM->sll_pkttype != PACKET_MULTICAST) |
| 389 | return 0; |
| 390 | |
| 391 | /* Only these types are recognised */ |
| 392 | if (ah->ar_op != htons(ARPOP_REQUEST) && |
| 393 | ah->ar_op != htons(ARPOP_REPLY)) |
| 394 | return 0; |
| 395 | |
| 396 | /* ARPHRD check and this darned FDDI hack here :-( */ |
| 397 | if (ah->ar_hrd != htons(FROM->sll_hatype) && |
| 398 | (FROM->sll_hatype != ARPHRD_FDDI || ah->ar_hrd != htons(ARPHRD_ETHER))) |
| 399 | return 0; |
| 400 | |
| 401 | /* Protocol must be IP. */ |
| 402 | if (ah->ar_pro != htons(ETH_P_IP)) |
| 403 | return 0; |
| 404 | if (ah->ar_pln != 4) |
| 405 | return 0; |
| 406 | if (ah->ar_hln != ((struct sockaddr_ll *)&me)->sll_halen) |
| 407 | return 0; |
| 408 | if (len < sizeof(*ah) + 2*(4 + ah->ar_hln)) |
| 409 | return 0; |
| 410 | memcpy(&src_ip, p+ah->ar_hln, 4); |
| 411 | memcpy(&dst_ip, p+ah->ar_hln+4+ah->ar_hln, 4); |
| 412 | if (!dad) { |
| 413 | if (src_ip.s_addr != dst.s_addr) |
| 414 | return 0; |
| 415 | if (src.s_addr != dst_ip.s_addr) |
| 416 | return 0; |
| 417 | if (memcmp(p+ah->ar_hln+4, ((struct sockaddr_ll *)&me)->sll_addr, ah->ar_hln)) |
| 418 | return 0; |
| 419 | } else { |
| 420 | /* DAD packet was: |
| 421 | src_ip = 0 (or some src) |
| 422 | src_hw = ME |
| 423 | dst_ip = tested address |
| 424 | dst_hw = <unspec> |
| 425 | |
| 426 | We fail, if receive request/reply with: |
| 427 | src_ip = tested_address |
| 428 | src_hw != ME |
| 429 | if src_ip in request was not zero, check |
| 430 | also that it matches to dst_ip, otherwise |
| 431 | dst_ip/dst_hw do not matter. |
| 432 | */ |
| 433 | if (src_ip.s_addr != dst.s_addr) |
| 434 | return 0; |
| 435 | if (memcmp(p, ((struct sockaddr_ll *)&me)->sll_addr, ((struct sockaddr_ll *)&me)->sll_halen) == 0) |
| 436 | return 0; |
| 437 | if (src.s_addr && src.s_addr != dst_ip.s_addr) |
| 438 | return 0; |
| 439 | } |
| 440 | if (!quiet) { |
| 441 | int s_printed = 0; |
| 442 | printf("%s ", FROM->sll_pkttype==PACKET_HOST ? "Unicast" : "Broadcast"); |
| 443 | printf("%s from ", ah->ar_op == htons(ARPOP_REPLY) ? "reply" : "request"); |
| 444 | printf("%s [", inet_ntoa(src_ip)); |
| 445 | print_hex(p, ah->ar_hln); |
| 446 | printf("] "); |
| 447 | if (dst_ip.s_addr != src.s_addr) { |
| 448 | printf("for %s ", inet_ntoa(dst_ip)); |
| 449 | s_printed = 1; |
| 450 | } |
| 451 | if (memcmp(p+ah->ar_hln+4, ((struct sockaddr_ll *)&me)->sll_addr, ah->ar_hln)) { |
| 452 | if (!s_printed) |
| 453 | printf("for "); |
| 454 | printf("["); |
| 455 | print_hex(p+ah->ar_hln+4, ah->ar_hln); |
| 456 | printf("]"); |
| 457 | } |
| 458 | if (last.tv_sec) { |
| 459 | long usecs = (tv.tv_sec-last.tv_sec) * 1000000 + |
| 460 | tv.tv_usec-last.tv_usec; |
| 461 | long msecs = (usecs+500)/1000; |
| 462 | usecs -= msecs*1000 - 500; |
| 463 | printf(" %ld.%03ldms\n", msecs, usecs); |
| 464 | } else { |
| 465 | printf(" UNSOLICITED?\n"); |
| 466 | } |
| 467 | fflush(stdout); |
| 468 | } |
| 469 | received++; |
| 470 | if (FROM->sll_pkttype != PACKET_HOST) |
| 471 | brd_recv++; |
| 472 | if (ah->ar_op == htons(ARPOP_REQUEST)) |
| 473 | req_recv++; |
| 474 | if (quit_on_reply) |
| 475 | finish(); |
| 476 | if(!broadcast_only) { |
| 477 | memcpy(((struct sockaddr_ll *)&he)->sll_addr, p, ((struct sockaddr_ll *)&me)->sll_halen); |
| 478 | unicasting=1; |
| 479 | } |
| 480 | return 1; |
| 481 | } |
| 482 | |
| 483 | #ifdef USE_SYSFS |
| 484 | union sysfs_devattr_value { |
| 485 | unsigned long ulong; |
| 486 | void *ptr; |
| 487 | }; |
| 488 | |
| 489 | enum { |
| 490 | SYSFS_DEVATTR_IFINDEX, |
| 491 | SYSFS_DEVATTR_FLAGS, |
| 492 | SYSFS_DEVATTR_ADDR_LEN, |
| 493 | #if 0 |
| 494 | SYSFS_DEVATTR_TYPE, |
| 495 | SYSFS_DEVATTR_ADDRESS, |
| 496 | #endif |
| 497 | SYSFS_DEVATTR_BROADCAST, |
| 498 | SYSFS_DEVATTR_NUM |
| 499 | }; |
| 500 | |
| 501 | struct sysfs_devattr_values |
| 502 | { |
| 503 | char *ifname; |
| 504 | union sysfs_devattr_value value[SYSFS_DEVATTR_NUM]; |
| 505 | }; |
| 506 | |
| 507 | static int sysfs_devattr_ulong_dec(char *ptr, struct sysfs_devattr_values *v, unsigned idx); |
| 508 | static int sysfs_devattr_ulong_hex(char *ptr, struct sysfs_devattr_values *v, unsigned idx); |
| 509 | static int sysfs_devattr_macaddr(char *ptr, struct sysfs_devattr_values *v, unsigned idx); |
| 510 | |
| 511 | struct sysfs_devattrs { |
| 512 | const char *name; |
| 513 | int (*handler)(char *ptr, struct sysfs_devattr_values *v, unsigned int idx); |
| 514 | int free; |
| 515 | } sysfs_devattrs[SYSFS_DEVATTR_NUM] = { |
| 516 | [SYSFS_DEVATTR_IFINDEX] = { |
| 517 | .name = "ifindex", |
| 518 | .handler = sysfs_devattr_ulong_dec, |
| 519 | }, |
| 520 | [SYSFS_DEVATTR_ADDR_LEN] = { |
| 521 | .name = "addr_len", |
| 522 | .handler = sysfs_devattr_ulong_dec, |
| 523 | }, |
| 524 | [SYSFS_DEVATTR_FLAGS] = { |
| 525 | .name = "flags", |
| 526 | .handler = sysfs_devattr_ulong_hex, |
| 527 | }, |
| 528 | #if 0 |
| 529 | [SYSFS_DEVATTR_TYPE] = { |
| 530 | .name = "type", |
| 531 | .handler = sysfs_devattr_ulong_dec, |
| 532 | }, |
| 533 | [SYSFS_DEVATTR_ADDRESS] = { |
| 534 | .name = "address", |
| 535 | .handler = sysfs_devattr_macaddr, |
| 536 | .free = 1, |
| 537 | }, |
| 538 | #endif |
| 539 | [SYSFS_DEVATTR_BROADCAST] = { |
| 540 | .name = "broadcast", |
| 541 | .handler = sysfs_devattr_macaddr, |
| 542 | .free = 1, |
| 543 | }, |
| 544 | }; |
| 545 | #endif |
| 546 | |
| 547 | /* |
| 548 | * find_device() |
| 549 | * |
| 550 | * This function checks 1) if the device (if given) is okay for ARP, |
| 551 | * or 2) find fist appropriate device on the system. |
| 552 | * |
| 553 | * Return value: |
| 554 | * >0 : Succeeded, and appropriate device not found. |
| 555 | * device.ifindex remains 0. |
| 556 | * 0 : Succeeded, and approptiate device found. |
| 557 | * device.ifindex is set. |
| 558 | * <0 : Failed. Support not found, or other |
| 559 | * : system error. Try other method. |
| 560 | * |
| 561 | * If an appropriate device found, it is recorded inside the |
| 562 | * "device" variable for later reference. |
| 563 | * |
| 564 | * We have several implementations for this. |
| 565 | * by_ifaddrs(): requires getifaddr() in glibc, and rtnetlink in |
| 566 | * kernel. default and recommended for recent systems. |
| 567 | * by_sysfs(): requires libsysfs , and sysfs in kernel. |
| 568 | * by_ioctl(): unable to list devices without ipv4 address; this |
| 569 | * means, you need to supply the device name for |
| 570 | * DAD purpose. |
| 571 | */ |
| 572 | /* Common check for ifa->ifa_flags */ |
| 573 | static int check_ifflags(unsigned int ifflags, int fatal) |
| 574 | { |
| 575 | if (!(ifflags & IFF_UP)) { |
| 576 | if (fatal) { |
| 577 | if (!quiet) |
| 578 | printf("Interface \"%s\" is down\n", device.name); |
| 579 | exit(2); |
| 580 | } |
| 581 | return -1; |
| 582 | } |
| 583 | if (ifflags & (IFF_NOARP | IFF_LOOPBACK)) { |
| 584 | if (fatal) { |
| 585 | if (!quiet) |
| 586 | printf("Interface \"%s\" is not ARPable\n", device.name); |
| 587 | exit(dad ? 0 : 2); |
| 588 | } |
| 589 | return -1; |
| 590 | } |
| 591 | return 0; |
| 592 | } |
| 593 | |
| 594 | static int find_device_by_ifaddrs(void) |
| 595 | { |
| 596 | #ifndef WITHOUT_IFADDRS |
| 597 | int rc; |
| 598 | struct ifaddrs *ifa0, *ifa; |
| 599 | int count = 0; |
| 600 | |
| 601 | rc = getifaddrs(&ifa0); |
| 602 | if (rc) { |
| 603 | perror("getifaddrs"); |
| 604 | return -1; |
| 605 | } |
| 606 | |
| 607 | for (ifa = ifa0; ifa; ifa = ifa->ifa_next) { |
| 608 | if (!ifa->ifa_addr) |
| 609 | continue; |
| 610 | if (ifa->ifa_addr->sa_family != AF_PACKET) |
| 611 | continue; |
| 612 | if (device.name && ifa->ifa_name && strcmp(ifa->ifa_name, device.name)) |
| 613 | continue; |
| 614 | |
| 615 | if (check_ifflags(ifa->ifa_flags, device.name != NULL) < 0) |
| 616 | continue; |
| 617 | |
| 618 | if (!((struct sockaddr_ll *)ifa->ifa_addr)->sll_halen) |
| 619 | continue; |
| 620 | if (!ifa->ifa_broadaddr) |
| 621 | continue; |
| 622 | |
| 623 | device.ifa = ifa; |
| 624 | |
| 625 | if (count++) |
| 626 | break; |
| 627 | } |
| 628 | |
| 629 | if (count == 1 && device.ifa) { |
| 630 | device.ifindex = if_nametoindex(device.ifa->ifa_name); |
| 631 | if (!device.ifindex) { |
| 632 | perror("arping: if_nametoindex"); |
| 633 | freeifaddrs(ifa0); |
| 634 | return -1; |
| 635 | } |
| 636 | device.name = device.ifa->ifa_name; |
| 637 | return 0; |
| 638 | } |
| 639 | return 1; |
| 640 | #else |
| 641 | return -1; |
| 642 | #endif |
| 643 | } |
| 644 | |
| 645 | #ifdef USE_SYSFS |
| 646 | static void sysfs_devattr_values_init(struct sysfs_devattr_values *v, int do_free) |
| 647 | { |
| 648 | int i; |
| 649 | if (do_free) { |
| 650 | free(v->ifname); |
| 651 | for (i = 0; i < SYSFS_DEVATTR_NUM; i++) { |
| 652 | if (sysfs_devattrs[i].free) |
| 653 | free(v->value[i].ptr); |
| 654 | } |
| 655 | } |
| 656 | memset(v, 0, sizeof(*v)); |
| 657 | } |
| 658 | |
| 659 | static int sysfs_devattr_ulong(char *ptr, struct sysfs_devattr_values *v, unsigned int idx, |
| 660 | unsigned int base) |
| 661 | { |
| 662 | unsigned long *p; |
| 663 | char *ep; |
| 664 | |
| 665 | if (!ptr || !v) |
| 666 | return -1; |
| 667 | |
| 668 | p = &v->value[idx].ulong; |
| 669 | errno = 0; |
| 670 | *p = strtoul(ptr, &ep, base); |
| 671 | if ((*ptr && isspace(*ptr & 0xff)) || errno || (*ep != '\0' && *ep != '\n')) |
| 672 | goto out; |
| 673 | |
| 674 | return 0; |
| 675 | out: |
| 676 | return -1; |
| 677 | } |
| 678 | |
| 679 | static int sysfs_devattr_ulong_dec(char *ptr, struct sysfs_devattr_values *v, unsigned int idx) |
| 680 | { |
| 681 | int rc = sysfs_devattr_ulong(ptr, v, idx, 10); |
| 682 | return rc; |
| 683 | } |
| 684 | |
| 685 | static int sysfs_devattr_ulong_hex(char *ptr, struct sysfs_devattr_values *v, unsigned int idx) |
| 686 | { |
| 687 | int rc = sysfs_devattr_ulong(ptr, v, idx, 16); |
| 688 | return rc; |
| 689 | } |
| 690 | |
| 691 | static int sysfs_devattr_macaddr(char *ptr, struct sysfs_devattr_values *v, unsigned int idx) |
| 692 | { |
| 693 | unsigned char *m; |
| 694 | int i; |
| 695 | unsigned int addrlen; |
| 696 | |
| 697 | if (!ptr || !v) |
| 698 | return -1; |
| 699 | |
| 700 | addrlen = v->value[SYSFS_DEVATTR_ADDR_LEN].ulong; |
| 701 | m = malloc(addrlen); |
| 702 | |
| 703 | for (i = 0; i < addrlen; i++) { |
| 704 | if (i && *(ptr + i * 3 - 1) != ':') |
| 705 | goto out; |
| 706 | if (sscanf(ptr + i * 3, "%02hhx", &m[i]) != 1) |
| 707 | goto out; |
| 708 | } |
| 709 | |
| 710 | v->value[idx].ptr = m; |
| 711 | return 0; |
| 712 | out: |
| 713 | free(m); |
| 714 | return -1; |
| 715 | } |
| 716 | #endif |
| 717 | |
| 718 | int find_device_by_sysfs(void) |
| 719 | { |
| 720 | int rc = -1; |
| 721 | #ifdef USE_SYSFS |
| 722 | struct sysfs_class *cls_net; |
| 723 | struct dlist *dev_list; |
| 724 | struct sysfs_class_device *dev; |
| 725 | struct sysfs_attribute *dev_attr; |
| 726 | struct sysfs_devattr_values sysfs_devattr_values; |
| 727 | int count = 0; |
| 728 | |
| 729 | if (!device.sysfs) { |
| 730 | device.sysfs = malloc(sizeof(*device.sysfs)); |
| 731 | sysfs_devattr_values_init(device.sysfs, 0); |
| 732 | } |
| 733 | |
| 734 | cls_net = sysfs_open_class("net"); |
| 735 | if (!cls_net) { |
| 736 | perror("sysfs_open_class"); |
| 737 | return -1; |
| 738 | } |
| 739 | |
| 740 | dev_list = sysfs_get_class_devices(cls_net); |
| 741 | if (!dev_list) { |
| 742 | perror("sysfs_get_class_devices"); |
| 743 | goto out; |
| 744 | } |
| 745 | |
| 746 | sysfs_devattr_values_init(&sysfs_devattr_values, 0); |
| 747 | |
| 748 | dlist_for_each_data(dev_list, dev, struct sysfs_class_device) { |
| 749 | int i; |
| 750 | int rc = -1; |
| 751 | |
| 752 | if (device.name && strcmp(dev->name, device.name)) |
| 753 | goto do_next; |
| 754 | |
| 755 | sysfs_devattr_values_init(&sysfs_devattr_values, 1); |
| 756 | |
| 757 | for (i = 0; i < SYSFS_DEVATTR_NUM; i++) { |
| 758 | |
| 759 | dev_attr = sysfs_get_classdev_attr(dev, sysfs_devattrs[i].name); |
| 760 | if (!dev_attr) { |
| 761 | perror("sysfs_get_classdev_attr"); |
| 762 | rc = -1; |
| 763 | break; |
| 764 | } |
| 765 | if (sysfs_read_attribute(dev_attr)) { |
| 766 | perror("sysfs_read_attribute"); |
| 767 | rc = -1; |
| 768 | break; |
| 769 | } |
| 770 | rc = sysfs_devattrs[i].handler(dev_attr->value, &sysfs_devattr_values, i); |
| 771 | |
| 772 | if (rc < 0) |
| 773 | break; |
| 774 | } |
| 775 | |
| 776 | if (rc < 0) |
| 777 | goto do_next; |
| 778 | |
| 779 | if (check_ifflags(sysfs_devattr_values.value[SYSFS_DEVATTR_FLAGS].ulong, |
| 780 | device.name != NULL) < 0) |
| 781 | goto do_next; |
| 782 | |
| 783 | if (!sysfs_devattr_values.value[SYSFS_DEVATTR_ADDR_LEN].ulong) |
| 784 | goto do_next; |
| 785 | |
| 786 | if (device.sysfs->value[SYSFS_DEVATTR_IFINDEX].ulong) { |
| 787 | if (device.sysfs->value[SYSFS_DEVATTR_FLAGS].ulong & IFF_RUNNING) |
| 788 | goto do_next; |
| 789 | } |
| 790 | |
| 791 | sysfs_devattr_values.ifname = strdup(dev->name); |
| 792 | if (!sysfs_devattr_values.ifname) { |
| 793 | perror("malloc"); |
| 794 | goto out; |
| 795 | } |
| 796 | |
| 797 | sysfs_devattr_values_init(device.sysfs, 1); |
| 798 | memcpy(device.sysfs, &sysfs_devattr_values, sizeof(*device.sysfs)); |
| 799 | sysfs_devattr_values_init(&sysfs_devattr_values, 0); |
| 800 | |
| 801 | if (count++) |
| 802 | break; |
| 803 | |
| 804 | continue; |
| 805 | do_next: |
| 806 | sysfs_devattr_values_init(&sysfs_devattr_values, 1); |
| 807 | } |
| 808 | |
| 809 | if (count == 1) { |
| 810 | device.ifindex = device.sysfs->value[SYSFS_DEVATTR_IFINDEX].ulong; |
| 811 | device.name = device.sysfs->ifname; |
| 812 | } |
| 813 | rc = !device.ifindex; |
| 814 | out: |
| 815 | sysfs_close_class(cls_net); |
| 816 | #endif |
| 817 | return rc; |
| 818 | } |
| 819 | |
| 820 | static int check_device_by_ioctl(int s, struct ifreq *ifr) |
| 821 | { |
| 822 | if (ioctl(s, SIOCGIFFLAGS, ifr) < 0) { |
| 823 | perror("ioctl(SIOCGIFINDEX"); |
| 824 | return -1; |
| 825 | } |
| 826 | |
| 827 | if (check_ifflags(ifr->ifr_flags, device.name != NULL) < 0) |
| 828 | return 1; |
| 829 | |
| 830 | if (ioctl(s, SIOCGIFINDEX, ifr) < 0) { |
| 831 | perror("ioctl(SIOCGIFINDEX"); |
| 832 | return -1; |
| 833 | } |
| 834 | |
| 835 | return 0; |
| 836 | } |
| 837 | |
| 838 | static int find_device_by_ioctl(void) |
| 839 | { |
| 840 | int s; |
| 841 | struct ifreq *ifr0, *ifr, *ifr_end; |
| 842 | size_t ifrsize = sizeof(*ifr); |
| 843 | struct ifconf ifc; |
| 844 | static struct ifreq ifrbuf; |
| 845 | int count = 0; |
| 846 | |
| 847 | s = socket(AF_INET, SOCK_DGRAM, 0); |
| 848 | if (s < 0) { |
| 849 | perror("socket"); |
| 850 | return -1; |
| 851 | } |
| 852 | |
| 853 | memset(&ifrbuf, 0, sizeof(ifrbuf)); |
| 854 | |
| 855 | if (device.name) { |
| 856 | strncpy(ifrbuf.ifr_name, device.name, sizeof(ifrbuf.ifr_name) - 1); |
| 857 | if (check_device_by_ioctl(s, &ifrbuf)) |
| 858 | goto out; |
| 859 | count++; |
| 860 | } else { |
| 861 | do { |
| 862 | int rc; |
| 863 | ifr0 = malloc(ifrsize); |
| 864 | if (!ifr0) { |
| 865 | perror("malloc"); |
| 866 | goto out; |
| 867 | } |
| 868 | |
| 869 | ifc.ifc_buf = (char *)ifr0; |
| 870 | ifc.ifc_len = ifrsize; |
| 871 | |
| 872 | rc = ioctl(s, SIOCGIFCONF, &ifc); |
| 873 | if (rc < 0) { |
| 874 | perror("ioctl(SIOCFIFCONF"); |
| 875 | goto out; |
| 876 | } |
| 877 | |
| 878 | if (ifc.ifc_len + sizeof(*ifr0) + sizeof(struct sockaddr_storage) - sizeof(struct sockaddr) <= ifrsize) |
| 879 | break; |
| 880 | ifrsize *= 2; |
| 881 | free(ifr0); |
| 882 | ifr0 = NULL; |
| 883 | } while(ifrsize < INT_MAX / 2); |
| 884 | |
| 885 | if (!ifr0) { |
| 886 | fprintf(stderr, "arping: too many interfaces!?\n"); |
| 887 | goto out; |
| 888 | } |
| 889 | |
| 890 | ifr_end = (struct ifreq *)(((char *)ifr0) + ifc.ifc_len - sizeof(*ifr0)); |
| 891 | for (ifr = ifr0; ifr <= ifr_end; ifr++) { |
| 892 | if (check_device_by_ioctl(s, &ifrbuf)) |
| 893 | continue; |
| 894 | memcpy(&ifrbuf.ifr_name, ifr->ifr_name, sizeof(ifrbuf.ifr_name)); |
| 895 | if (count++) |
| 896 | break; |
| 897 | } |
| 898 | } |
| 899 | |
| 900 | close(s); |
| 901 | |
| 902 | if (count == 1) { |
| 903 | device.ifindex = ifrbuf.ifr_ifindex; |
| 904 | device.name = ifrbuf.ifr_name; |
| 905 | } |
| 906 | return !device.ifindex; |
| 907 | out: |
| 908 | close(s); |
| 909 | return -1; |
| 910 | } |
| 911 | |
| 912 | static int find_device(void) |
| 913 | { |
| 914 | int rc; |
| 915 | rc = find_device_by_ifaddrs(); |
| 916 | if (rc >= 0) |
| 917 | goto out; |
| 918 | rc = find_device_by_sysfs(); |
| 919 | if (rc >= 0) |
| 920 | goto out; |
| 921 | rc = find_device_by_ioctl(); |
| 922 | out: |
| 923 | return rc; |
| 924 | } |
| 925 | |
| 926 | /* |
| 927 | * set_device_broadcast() |
| 928 | * |
| 929 | * This fills the device "broadcast address" |
| 930 | * based on information found by find_device() funcion. |
| 931 | */ |
| 932 | static int set_device_broadcast_ifaddrs_one(struct device *device, unsigned char *ba, size_t balen, int fatal) |
| 933 | { |
| 934 | #ifndef WITHOUT_IFADDRS |
| 935 | struct ifaddrs *ifa; |
| 936 | struct sockaddr_ll *sll; |
| 937 | |
| 938 | if (!device) |
| 939 | return -1; |
| 940 | |
| 941 | ifa = device->ifa; |
| 942 | if (!ifa) |
| 943 | return -1; |
| 944 | |
| 945 | sll = (struct sockaddr_ll *)ifa->ifa_broadaddr; |
| 946 | |
| 947 | if (sll->sll_halen != balen) { |
| 948 | if (fatal) { |
| 949 | if (!quiet) |
| 950 | printf("Address length does not match...\n"); |
| 951 | exit(2); |
| 952 | } |
| 953 | return -1; |
| 954 | } |
| 955 | memcpy(ba, sll->sll_addr, sll->sll_halen); |
| 956 | return 0; |
| 957 | #else |
| 958 | return -1; |
| 959 | #endif |
| 960 | } |
| 961 | int set_device_broadcast_sysfs(struct device *device, unsigned char *ba, size_t balen) |
| 962 | { |
| 963 | #ifdef USE_SYSFS |
| 964 | struct sysfs_devattr_values *v; |
| 965 | if (!device) |
| 966 | return -1; |
| 967 | v = device->sysfs; |
| 968 | if (!v) |
| 969 | return -1; |
| 970 | if (v->value[SYSFS_DEVATTR_ADDR_LEN].ulong != balen) |
| 971 | return -1; |
| 972 | memcpy(ba, v->value[SYSFS_DEVATTR_BROADCAST].ptr, balen); |
| 973 | return 0; |
| 974 | #else |
| 975 | return -1; |
| 976 | #endif |
| 977 | } |
| 978 | |
| 979 | static int set_device_broadcast_fallback(struct device *device, unsigned char *ba, size_t balen) |
| 980 | { |
| 981 | if (!quiet) |
| 982 | fprintf(stderr, "WARNING: using default broadcast address.\n"); |
| 983 | memset(ba, -1, balen); |
| 984 | return 0; |
| 985 | } |
| 986 | |
| 987 | static void set_device_broadcast(struct device *dev, unsigned char *ba, size_t balen) |
| 988 | { |
| 989 | if (!set_device_broadcast_ifaddrs_one(dev, ba, balen, 0)) |
| 990 | return; |
| 991 | if (!set_device_broadcast_sysfs(dev, ba, balen)) |
| 992 | return; |
| 993 | set_device_broadcast_fallback(dev, ba, balen); |
| 994 | } |
| 995 | |
| 996 | int |
| 997 | main(int argc, char **argv) |
| 998 | { |
| 999 | int socket_errno; |
| 1000 | int ch; |
| 1001 | |
| 1002 | limit_capabilities(); |
| 1003 | |
| 1004 | #ifdef USE_IDN |
| 1005 | setlocale(LC_ALL, ""); |
| 1006 | #endif |
| 1007 | |
| 1008 | enable_capability_raw(); |
| 1009 | |
| 1010 | s = socket(PF_PACKET, SOCK_DGRAM, 0); |
| 1011 | socket_errno = errno; |
| 1012 | |
| 1013 | disable_capability_raw(); |
| 1014 | |
| 1015 | while ((ch = getopt(argc, argv, "h?bfDUAqc:w:s:I:V")) != EOF) { |
| 1016 | switch(ch) { |
| 1017 | case 'b': |
| 1018 | broadcast_only=1; |
| 1019 | break; |
| 1020 | case 'D': |
| 1021 | dad++; |
| 1022 | quit_on_reply=1; |
| 1023 | break; |
| 1024 | case 'U': |
| 1025 | unsolicited++; |
| 1026 | break; |
| 1027 | case 'A': |
| 1028 | advert++; |
| 1029 | unsolicited++; |
| 1030 | break; |
| 1031 | case 'q': |
| 1032 | quiet++; |
| 1033 | break; |
| 1034 | case 'c': |
| 1035 | count = atoi(optarg); |
| 1036 | break; |
| 1037 | case 'w': |
| 1038 | timeout = atoi(optarg); |
| 1039 | break; |
| 1040 | case 'I': |
| 1041 | device.name = optarg; |
| 1042 | break; |
| 1043 | case 'f': |
| 1044 | quit_on_reply=1; |
| 1045 | break; |
| 1046 | case 's': |
| 1047 | source = optarg; |
| 1048 | break; |
| 1049 | case 'V': |
| 1050 | printf("arping utility, iputils-%s\n", SNAPSHOT); |
| 1051 | exit(0); |
| 1052 | case 'h': |
| 1053 | case '?': |
| 1054 | default: |
| 1055 | usage(); |
| 1056 | } |
| 1057 | } |
| 1058 | argc -= optind; |
| 1059 | argv += optind; |
| 1060 | |
| 1061 | if (argc != 1) |
| 1062 | usage(); |
| 1063 | |
| 1064 | target = *argv; |
| 1065 | |
| 1066 | if (device.name && !*device.name) |
| 1067 | device.name = NULL; |
| 1068 | |
| 1069 | if (s < 0) { |
| 1070 | errno = socket_errno; |
| 1071 | perror("arping: socket"); |
| 1072 | exit(2); |
| 1073 | } |
| 1074 | |
| 1075 | if (find_device() < 0) |
| 1076 | exit(2); |
| 1077 | |
| 1078 | if (!device.ifindex) { |
| 1079 | if (device.name) { |
| 1080 | fprintf(stderr, "arping: Device %s not available.\n", device.name); |
| 1081 | exit(2); |
| 1082 | } |
| 1083 | fprintf(stderr, "arping: device (option -I) is required.\n"); |
| 1084 | usage(); |
| 1085 | } |
| 1086 | |
| 1087 | if (inet_aton(target, &dst) != 1) { |
| 1088 | struct hostent *hp; |
| 1089 | char *idn = target; |
| 1090 | #ifdef USE_IDN |
| 1091 | int rc; |
| 1092 | |
| 1093 | rc = idna_to_ascii_lz(target, &idn, 0); |
| 1094 | |
| 1095 | if (rc != IDNA_SUCCESS) { |
| 1096 | fprintf(stderr, "arping: IDN encoding failed: %s\n", idna_strerror(rc)); |
| 1097 | exit(2); |
| 1098 | } |
| 1099 | #endif |
| 1100 | |
| 1101 | hp = gethostbyname2(idn, AF_INET); |
| 1102 | if (!hp) { |
| 1103 | fprintf(stderr, "arping: unknown host %s\n", target); |
| 1104 | exit(2); |
| 1105 | } |
| 1106 | |
| 1107 | #ifdef USE_IDN |
| 1108 | free(idn); |
| 1109 | #endif |
| 1110 | |
| 1111 | memcpy(&dst, hp->h_addr, 4); |
| 1112 | } |
| 1113 | |
| 1114 | if (source && inet_aton(source, &src) != 1) { |
| 1115 | fprintf(stderr, "arping: invalid source %s\n", source); |
| 1116 | exit(2); |
| 1117 | } |
| 1118 | |
| 1119 | if (!dad && unsolicited && src.s_addr == 0) |
| 1120 | src = dst; |
| 1121 | |
| 1122 | if (!dad || src.s_addr) { |
| 1123 | struct sockaddr_in saddr; |
| 1124 | int probe_fd = socket(AF_INET, SOCK_DGRAM, 0); |
| 1125 | |
| 1126 | if (probe_fd < 0) { |
| 1127 | perror("socket"); |
| 1128 | exit(2); |
| 1129 | } |
| 1130 | if (device.name) { |
| 1131 | enable_capability_raw(); |
| 1132 | |
| 1133 | if (setsockopt(probe_fd, SOL_SOCKET, SO_BINDTODEVICE, device.name, strlen(device.name)+1) == -1) |
| 1134 | perror("WARNING: interface is ignored"); |
| 1135 | |
| 1136 | disable_capability_raw(); |
| 1137 | } |
| 1138 | memset(&saddr, 0, sizeof(saddr)); |
| 1139 | saddr.sin_family = AF_INET; |
| 1140 | if (src.s_addr) { |
| 1141 | saddr.sin_addr = src; |
| 1142 | if (bind(probe_fd, (struct sockaddr*)&saddr, sizeof(saddr)) == -1) { |
| 1143 | perror("bind"); |
| 1144 | exit(2); |
| 1145 | } |
| 1146 | } else if (!dad) { |
| 1147 | int on = 1; |
| 1148 | socklen_t alen = sizeof(saddr); |
| 1149 | |
| 1150 | saddr.sin_port = htons(1025); |
| 1151 | saddr.sin_addr = dst; |
| 1152 | |
| 1153 | if (setsockopt(probe_fd, SOL_SOCKET, SO_DONTROUTE, (char*)&on, sizeof(on)) == -1) |
| 1154 | perror("WARNING: setsockopt(SO_DONTROUTE)"); |
| 1155 | if (connect(probe_fd, (struct sockaddr*)&saddr, sizeof(saddr)) == -1) { |
| 1156 | perror("connect"); |
| 1157 | exit(2); |
| 1158 | } |
| 1159 | if (getsockname(probe_fd, (struct sockaddr*)&saddr, &alen) == -1) { |
| 1160 | perror("getsockname"); |
| 1161 | exit(2); |
| 1162 | } |
| 1163 | src = saddr.sin_addr; |
| 1164 | } |
| 1165 | close(probe_fd); |
| 1166 | }; |
| 1167 | |
| 1168 | ((struct sockaddr_ll *)&me)->sll_family = AF_PACKET; |
| 1169 | ((struct sockaddr_ll *)&me)->sll_ifindex = device.ifindex; |
| 1170 | ((struct sockaddr_ll *)&me)->sll_protocol = htons(ETH_P_ARP); |
| 1171 | if (bind(s, (struct sockaddr*)&me, sizeof(me)) == -1) { |
| 1172 | perror("bind"); |
| 1173 | exit(2); |
| 1174 | } |
| 1175 | |
| 1176 | if (1) { |
| 1177 | socklen_t alen = sizeof(me); |
| 1178 | if (getsockname(s, (struct sockaddr*)&me, &alen) == -1) { |
| 1179 | perror("getsockname"); |
| 1180 | exit(2); |
| 1181 | } |
| 1182 | } |
| 1183 | if (((struct sockaddr_ll *)&me)->sll_halen == 0) { |
| 1184 | if (!quiet) |
| 1185 | printf("Interface \"%s\" is not ARPable (no ll address)\n", device.name); |
| 1186 | exit(dad?0:2); |
| 1187 | } |
| 1188 | |
| 1189 | he = me; |
| 1190 | |
| 1191 | set_device_broadcast(&device, ((struct sockaddr_ll *)&he)->sll_addr, |
| 1192 | ((struct sockaddr_ll *)&he)->sll_halen); |
| 1193 | |
| 1194 | if (!quiet) { |
| 1195 | printf("ARPING %s ", inet_ntoa(dst)); |
| 1196 | printf("from %s %s\n", inet_ntoa(src), device.name ? : ""); |
| 1197 | } |
| 1198 | |
| 1199 | if (!src.s_addr && !dad) { |
| 1200 | fprintf(stderr, "arping: no source address in not-DAD mode\n"); |
| 1201 | exit(2); |
| 1202 | } |
| 1203 | |
| 1204 | drop_capabilities(); |
| 1205 | |
| 1206 | set_signal(SIGINT, finish); |
| 1207 | set_signal(SIGALRM, catcher); |
| 1208 | |
| 1209 | catcher(); |
| 1210 | |
| 1211 | while(1) { |
| 1212 | sigset_t sset, osset; |
| 1213 | unsigned char packet[4096]; |
| 1214 | struct sockaddr_storage from; |
| 1215 | socklen_t alen = sizeof(from); |
| 1216 | int cc; |
| 1217 | |
| 1218 | if ((cc = recvfrom(s, packet, sizeof(packet), 0, |
| 1219 | (struct sockaddr *)&from, &alen)) < 0) { |
| 1220 | perror("arping: recvfrom"); |
| 1221 | continue; |
| 1222 | } |
| 1223 | |
| 1224 | sigemptyset(&sset); |
| 1225 | sigaddset(&sset, SIGALRM); |
| 1226 | sigaddset(&sset, SIGINT); |
| 1227 | sigprocmask(SIG_BLOCK, &sset, &osset); |
| 1228 | recv_pack(packet, cc, (struct sockaddr_ll *)&from); |
| 1229 | sigprocmask(SIG_SETMASK, &osset, NULL); |
| 1230 | } |
| 1231 | } |
| 1232 | |
| 1233 | |