Lorenzo Colitti | 313379e | 2013-07-11 01:07:11 +0900 | [diff] [blame] | 1 | /* |
| 2 | * tracepath6.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 | */ |
| 11 | |
| 12 | #include <stdio.h> |
| 13 | #include <stdlib.h> |
| 14 | #include <unistd.h> |
| 15 | #include <sys/socket.h> |
| 16 | #include <netinet/in.h> |
| 17 | #include <netinet/icmp6.h> |
| 18 | |
| 19 | #include <linux/types.h> |
| 20 | #include <linux/errqueue.h> |
| 21 | #include <errno.h> |
| 22 | #include <string.h> |
| 23 | #include <netdb.h> |
| 24 | #include <resolv.h> |
| 25 | #include <sys/time.h> |
| 26 | #include <sys/uio.h> |
| 27 | #include <arpa/inet.h> |
| 28 | |
| 29 | #ifdef USE_IDN |
| 30 | #include <idna.h> |
| 31 | #include <locale.h> |
| 32 | #endif |
| 33 | |
| 34 | #ifndef SOL_IPV6 |
| 35 | #define SOL_IPV6 IPPROTO_IPV6 |
| 36 | #endif |
| 37 | |
| 38 | #ifndef IP_PMTUDISC_DO |
| 39 | #define IP_PMTUDISC_DO 3 |
| 40 | #endif |
| 41 | #ifndef IPV6_PMTUDISC_DO |
| 42 | #define IPV6_PMTUDISC_DO 3 |
| 43 | #endif |
| 44 | |
| 45 | #define MAX_HOPS_LIMIT 255 |
| 46 | #define MAX_HOPS_DEFAULT 30 |
| 47 | |
| 48 | struct hhistory |
| 49 | { |
| 50 | int hops; |
| 51 | struct timeval sendtime; |
| 52 | }; |
| 53 | |
| 54 | struct hhistory his[64]; |
| 55 | int hisptr; |
| 56 | |
| 57 | sa_family_t family = AF_INET6; |
| 58 | struct sockaddr_storage target; |
| 59 | socklen_t targetlen; |
| 60 | __u16 base_port; |
| 61 | int max_hops = MAX_HOPS_DEFAULT; |
| 62 | |
| 63 | int overhead; |
| 64 | int mtu; |
| 65 | void *pktbuf; |
| 66 | int hops_to = -1; |
| 67 | int hops_from = -1; |
| 68 | int no_resolve = 0; |
| 69 | int show_both = 0; |
| 70 | int mapped; |
| 71 | |
| 72 | #define HOST_COLUMN_SIZE 52 |
| 73 | |
| 74 | struct probehdr |
| 75 | { |
| 76 | __u32 ttl; |
| 77 | struct timeval tv; |
| 78 | }; |
| 79 | |
| 80 | void data_wait(int fd) |
| 81 | { |
| 82 | fd_set fds; |
| 83 | struct timeval tv; |
| 84 | FD_ZERO(&fds); |
| 85 | FD_SET(fd, &fds); |
| 86 | tv.tv_sec = 1; |
| 87 | tv.tv_usec = 0; |
| 88 | select(fd+1, &fds, NULL, NULL, &tv); |
| 89 | } |
| 90 | |
| 91 | void print_host(const char *a, const char *b, int both) |
| 92 | { |
| 93 | int plen; |
| 94 | plen = printf("%s", a); |
| 95 | if (both) |
| 96 | plen += printf(" (%s)", b); |
| 97 | if (plen >= HOST_COLUMN_SIZE) |
| 98 | plen = HOST_COLUMN_SIZE - 1; |
| 99 | printf("%*s", HOST_COLUMN_SIZE - plen, ""); |
| 100 | } |
| 101 | |
| 102 | int recverr(int fd, int ttl) |
| 103 | { |
| 104 | int res; |
| 105 | struct probehdr rcvbuf; |
| 106 | char cbuf[512]; |
| 107 | struct iovec iov; |
| 108 | struct msghdr msg; |
| 109 | struct cmsghdr *cmsg; |
| 110 | struct sock_extended_err *e; |
| 111 | struct sockaddr_storage addr; |
| 112 | struct timeval tv; |
| 113 | struct timeval *rettv; |
| 114 | int slot = 0; |
| 115 | int rethops; |
| 116 | int sndhops; |
| 117 | int progress = -1; |
| 118 | int broken_router; |
| 119 | |
| 120 | restart: |
| 121 | memset(&rcvbuf, -1, sizeof(rcvbuf)); |
| 122 | iov.iov_base = &rcvbuf; |
| 123 | iov.iov_len = sizeof(rcvbuf); |
| 124 | msg.msg_name = (caddr_t)&addr; |
| 125 | msg.msg_namelen = sizeof(addr); |
| 126 | msg.msg_iov = &iov; |
| 127 | msg.msg_iovlen = 1; |
| 128 | msg.msg_flags = 0; |
| 129 | msg.msg_control = cbuf; |
| 130 | msg.msg_controllen = sizeof(cbuf); |
| 131 | |
| 132 | gettimeofday(&tv, NULL); |
| 133 | res = recvmsg(fd, &msg, MSG_ERRQUEUE); |
| 134 | if (res < 0) { |
| 135 | if (errno == EAGAIN) |
| 136 | return progress; |
| 137 | goto restart; |
| 138 | } |
| 139 | |
| 140 | progress = mtu; |
| 141 | |
| 142 | rethops = -1; |
| 143 | sndhops = -1; |
| 144 | e = NULL; |
| 145 | rettv = NULL; |
| 146 | |
| 147 | slot = -base_port; |
| 148 | switch (family) { |
| 149 | case AF_INET6: |
| 150 | slot += ntohs(((struct sockaddr_in6 *)&addr)->sin6_port); |
| 151 | break; |
| 152 | case AF_INET: |
| 153 | slot += ntohs(((struct sockaddr_in *)&addr)->sin_port); |
| 154 | break; |
| 155 | } |
| 156 | |
| 157 | if (slot >= 0 && slot < 63 && his[slot].hops) { |
| 158 | sndhops = his[slot].hops; |
| 159 | rettv = &his[slot].sendtime; |
| 160 | his[slot].hops = 0; |
| 161 | } |
| 162 | broken_router = 0; |
| 163 | if (res == sizeof(rcvbuf)) { |
| 164 | if (rcvbuf.ttl == 0 || rcvbuf.tv.tv_sec == 0) |
| 165 | broken_router = 1; |
| 166 | else { |
| 167 | sndhops = rcvbuf.ttl; |
| 168 | rettv = &rcvbuf.tv; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { |
| 173 | switch (cmsg->cmsg_level) { |
| 174 | case SOL_IPV6: |
| 175 | switch(cmsg->cmsg_type) { |
| 176 | case IPV6_RECVERR: |
| 177 | e = (struct sock_extended_err *)CMSG_DATA(cmsg); |
| 178 | break; |
| 179 | case IPV6_HOPLIMIT: |
| 180 | #ifdef IPV6_2292HOPLIMIT |
| 181 | case IPV6_2292HOPLIMIT: |
| 182 | #endif |
| 183 | memcpy(&rethops, CMSG_DATA(cmsg), sizeof(rethops)); |
| 184 | break; |
| 185 | default: |
| 186 | printf("cmsg6:%d\n ", cmsg->cmsg_type); |
| 187 | } |
| 188 | break; |
| 189 | case SOL_IP: |
| 190 | switch(cmsg->cmsg_type) { |
| 191 | case IP_RECVERR: |
| 192 | e = (struct sock_extended_err *)CMSG_DATA(cmsg); |
| 193 | break; |
| 194 | case IP_TTL: |
| 195 | rethops = *(__u8*)CMSG_DATA(cmsg); |
| 196 | break; |
| 197 | default: |
| 198 | printf("cmsg4:%d\n ", cmsg->cmsg_type); |
| 199 | } |
| 200 | } |
| 201 | } |
| 202 | if (e == NULL) { |
| 203 | printf("no info\n"); |
| 204 | return 0; |
| 205 | } |
| 206 | if (e->ee_origin == SO_EE_ORIGIN_LOCAL) |
| 207 | printf("%2d?: %-32s ", ttl, "[LOCALHOST]"); |
| 208 | else if (e->ee_origin == SO_EE_ORIGIN_ICMP6 || |
| 209 | e->ee_origin == SO_EE_ORIGIN_ICMP) { |
| 210 | char abuf[NI_MAXHOST], hbuf[NI_MAXHOST]; |
| 211 | struct sockaddr *sa = (struct sockaddr *)(e + 1); |
| 212 | socklen_t salen; |
| 213 | |
| 214 | if (sndhops>0) |
| 215 | printf("%2d: ", sndhops); |
| 216 | else |
| 217 | printf("%2d?: ", ttl); |
| 218 | |
| 219 | switch (sa->sa_family) { |
| 220 | case AF_INET6: |
| 221 | salen = sizeof(struct sockaddr_in6); |
| 222 | break; |
| 223 | case AF_INET: |
| 224 | salen = sizeof(struct sockaddr_in); |
| 225 | break; |
| 226 | default: |
| 227 | salen = 0; |
| 228 | } |
| 229 | |
| 230 | if (no_resolve || show_both) { |
| 231 | if (getnameinfo(sa, salen, |
| 232 | abuf, sizeof(abuf), NULL, 0, |
| 233 | NI_NUMERICHOST)) |
| 234 | strcpy(abuf, "???"); |
| 235 | } else |
| 236 | abuf[0] = 0; |
| 237 | |
| 238 | if (!no_resolve || show_both) { |
| 239 | fflush(stdout); |
| 240 | if (getnameinfo(sa, salen, |
| 241 | hbuf, sizeof(hbuf), NULL, 0, |
| 242 | 0 |
| 243 | #ifdef USE_IDN |
| 244 | | NI_IDN |
| 245 | #endif |
| 246 | )) |
| 247 | strcpy(hbuf, "???"); |
| 248 | } else |
| 249 | hbuf[0] = 0; |
| 250 | |
| 251 | if (no_resolve) |
| 252 | print_host(abuf, hbuf, show_both); |
| 253 | else |
| 254 | print_host(hbuf, abuf, show_both); |
| 255 | } |
| 256 | |
| 257 | if (rettv) { |
| 258 | int diff = (tv.tv_sec-rettv->tv_sec)*1000000+(tv.tv_usec-rettv->tv_usec); |
| 259 | printf("%3d.%03dms ", diff/1000, diff%1000); |
| 260 | if (broken_router) |
| 261 | printf("(This broken router returned corrupted payload) "); |
| 262 | } |
| 263 | |
| 264 | switch (e->ee_errno) { |
| 265 | case ETIMEDOUT: |
| 266 | printf("\n"); |
| 267 | break; |
| 268 | case EMSGSIZE: |
| 269 | printf("pmtu %d\n", e->ee_info); |
| 270 | mtu = e->ee_info; |
| 271 | progress = mtu; |
| 272 | break; |
| 273 | case ECONNREFUSED: |
| 274 | printf("reached\n"); |
| 275 | hops_to = sndhops<0 ? ttl : sndhops; |
| 276 | hops_from = rethops; |
| 277 | return 0; |
| 278 | case EPROTO: |
| 279 | printf("!P\n"); |
| 280 | return 0; |
| 281 | case EHOSTUNREACH: |
| 282 | if ((e->ee_origin == SO_EE_ORIGIN_ICMP && |
| 283 | e->ee_type == 11 && |
| 284 | e->ee_code == 0) || |
| 285 | (e->ee_origin == SO_EE_ORIGIN_ICMP6 && |
| 286 | e->ee_type == 3 && |
| 287 | e->ee_code == 0)) { |
| 288 | if (rethops>=0) { |
| 289 | if (rethops<=64) |
| 290 | rethops = 65-rethops; |
| 291 | else if (rethops<=128) |
| 292 | rethops = 129-rethops; |
| 293 | else |
| 294 | rethops = 256-rethops; |
| 295 | if (sndhops>=0 && rethops != sndhops) |
| 296 | printf("asymm %2d ", rethops); |
| 297 | else if (sndhops<0 && rethops != ttl) |
| 298 | printf("asymm %2d ", rethops); |
| 299 | } |
| 300 | printf("\n"); |
| 301 | break; |
| 302 | } |
| 303 | printf("!H\n"); |
| 304 | return 0; |
| 305 | case ENETUNREACH: |
| 306 | printf("!N\n"); |
| 307 | return 0; |
| 308 | case EACCES: |
| 309 | printf("!A\n"); |
| 310 | return 0; |
| 311 | default: |
| 312 | printf("\n"); |
| 313 | errno = e->ee_errno; |
| 314 | perror("NET ERROR"); |
| 315 | return 0; |
| 316 | } |
| 317 | goto restart; |
| 318 | } |
| 319 | |
| 320 | int probe_ttl(int fd, int ttl) |
| 321 | { |
| 322 | int i; |
| 323 | struct probehdr *hdr = pktbuf; |
| 324 | |
| 325 | memset(pktbuf, 0, mtu); |
| 326 | restart: |
| 327 | |
| 328 | for (i=0; i<10; i++) { |
| 329 | int res; |
| 330 | |
| 331 | hdr->ttl = ttl; |
| 332 | switch (family) { |
| 333 | case AF_INET6: |
| 334 | ((struct sockaddr_in6 *)&target)->sin6_port = htons(base_port + hisptr); |
| 335 | break; |
| 336 | case AF_INET: |
| 337 | ((struct sockaddr_in *)&target)->sin_port = htons(base_port + hisptr); |
| 338 | break; |
| 339 | } |
| 340 | gettimeofday(&hdr->tv, NULL); |
| 341 | his[hisptr].hops = ttl; |
| 342 | his[hisptr].sendtime = hdr->tv; |
| 343 | if (sendto(fd, pktbuf, mtu-overhead, 0, (struct sockaddr *)&target, targetlen) > 0) |
| 344 | break; |
| 345 | res = recverr(fd, ttl); |
| 346 | his[hisptr].hops = 0; |
| 347 | if (res==0) |
| 348 | return 0; |
| 349 | if (res > 0) |
| 350 | goto restart; |
| 351 | } |
| 352 | hisptr = (hisptr + 1) & 63; |
| 353 | |
| 354 | if (i<10) { |
| 355 | data_wait(fd); |
| 356 | if (recv(fd, pktbuf, mtu, MSG_DONTWAIT) > 0) { |
| 357 | printf("%2d?: reply received 8)\n", ttl); |
| 358 | return 0; |
| 359 | } |
| 360 | return recverr(fd, ttl); |
| 361 | } |
| 362 | |
| 363 | printf("%2d: send failed\n", ttl); |
| 364 | return 0; |
| 365 | } |
| 366 | |
| 367 | static void usage(void) __attribute((noreturn)); |
| 368 | |
| 369 | static void usage(void) |
| 370 | { |
| 371 | fprintf(stderr, "Usage: tracepath6 [-n] [-b] [-l <len>] [-p port] <destination>\n"); |
| 372 | exit(-1); |
| 373 | } |
| 374 | |
| 375 | |
| 376 | int main(int argc, char **argv) |
| 377 | { |
| 378 | int fd; |
| 379 | int on; |
| 380 | int ttl; |
| 381 | char *p; |
| 382 | struct addrinfo hints, *ai, *ai0; |
| 383 | int ch; |
| 384 | int gai; |
| 385 | char pbuf[NI_MAXSERV]; |
| 386 | |
| 387 | #ifdef USE_IDN |
| 388 | setlocale(LC_ALL, ""); |
| 389 | #endif |
| 390 | |
| 391 | while ((ch = getopt(argc, argv, "nbh?l:m:p:")) != EOF) { |
| 392 | switch(ch) { |
| 393 | case 'n': |
| 394 | no_resolve = 1; |
| 395 | break; |
| 396 | case 'b': |
| 397 | show_both = 1; |
| 398 | break; |
| 399 | case 'l': |
| 400 | mtu = atoi(optarg); |
| 401 | break; |
| 402 | case 'm': |
| 403 | max_hops = atoi(optarg); |
| 404 | if (max_hops < 0 || max_hops > MAX_HOPS_LIMIT) { |
| 405 | fprintf(stderr, |
| 406 | "Error: max hops must be 0 .. %d (inclusive).\n", |
| 407 | MAX_HOPS_LIMIT); |
| 408 | } |
| 409 | break; |
| 410 | case 'p': |
| 411 | base_port = atoi(optarg); |
| 412 | break; |
| 413 | default: |
| 414 | usage(); |
| 415 | } |
| 416 | } |
| 417 | |
| 418 | argc -= optind; |
| 419 | argv += optind; |
| 420 | |
| 421 | if (argc != 1) |
| 422 | usage(); |
| 423 | |
| 424 | /* Backward compatiblity */ |
| 425 | if (!base_port) { |
| 426 | p = strchr(argv[0], '/'); |
| 427 | if (p) { |
| 428 | *p = 0; |
| 429 | base_port = (unsigned)atoi(p+1); |
| 430 | } else { |
| 431 | base_port = 44444; |
| 432 | } |
| 433 | } |
| 434 | sprintf(pbuf, "%u", base_port); |
| 435 | |
| 436 | memset(&hints, 0, sizeof(hints)); |
| 437 | hints.ai_family = family; |
| 438 | hints.ai_socktype = SOCK_DGRAM; |
| 439 | hints.ai_protocol = IPPROTO_UDP; |
| 440 | #ifdef USE_IDN |
| 441 | hints.ai_flags = AI_IDN; |
| 442 | #endif |
| 443 | gai = getaddrinfo(argv[0], pbuf, &hints, &ai0); |
| 444 | if (gai) { |
| 445 | fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(gai)); |
| 446 | exit(1); |
| 447 | } |
| 448 | |
| 449 | fd = -1; |
| 450 | for (ai = ai0; ai; ai = ai->ai_next) { |
| 451 | /* sanity check */ |
| 452 | if (family && ai->ai_family != family) |
| 453 | continue; |
| 454 | if (ai->ai_family != AF_INET6 && |
| 455 | ai->ai_family != AF_INET) |
| 456 | continue; |
| 457 | family = ai->ai_family; |
| 458 | fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
| 459 | if (fd < 0) |
| 460 | continue; |
| 461 | memcpy(&target, ai->ai_addr, sizeof(target)); |
| 462 | targetlen = ai->ai_addrlen; |
| 463 | break; |
| 464 | } |
| 465 | if (fd < 0) { |
| 466 | perror("socket/connect"); |
| 467 | exit(1); |
| 468 | } |
| 469 | freeaddrinfo(ai0); |
| 470 | |
| 471 | switch (family) { |
| 472 | case AF_INET6: |
| 473 | overhead = 48; |
| 474 | if (!mtu) |
| 475 | mtu = 128000; |
| 476 | if (mtu <= overhead) |
| 477 | goto pktlen_error; |
| 478 | |
| 479 | on = IPV6_PMTUDISC_DO; |
| 480 | if (setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &on, sizeof(on)) && |
| 481 | (on = IPV6_PMTUDISC_DO, |
| 482 | setsockopt(fd, SOL_IPV6, IPV6_MTU_DISCOVER, &on, sizeof(on)))) { |
| 483 | perror("IPV6_MTU_DISCOVER"); |
| 484 | exit(1); |
| 485 | } |
| 486 | on = 1; |
| 487 | if (setsockopt(fd, SOL_IPV6, IPV6_RECVERR, &on, sizeof(on))) { |
| 488 | perror("IPV6_RECVERR"); |
| 489 | exit(1); |
| 490 | } |
| 491 | if ( |
| 492 | #ifdef IPV6_RECVHOPLIMIT |
| 493 | setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &on, sizeof(on)) && |
| 494 | setsockopt(fd, SOL_IPV6, IPV6_2292HOPLIMIT, &on, sizeof(on)) |
| 495 | #else |
| 496 | setsockopt(fd, SOL_IPV6, IPV6_HOPLIMIT, &on, sizeof(on)) |
| 497 | #endif |
| 498 | ) { |
| 499 | perror("IPV6_HOPLIMIT"); |
| 500 | exit(1); |
| 501 | } |
| 502 | if (!IN6_IS_ADDR_V4MAPPED(&(((struct sockaddr_in6 *)&target)->sin6_addr))) |
| 503 | break; |
| 504 | mapped = 1; |
| 505 | /*FALLTHROUGH*/ |
| 506 | case AF_INET: |
| 507 | overhead = 28; |
| 508 | if (!mtu) |
| 509 | mtu = 65535; |
| 510 | if (mtu <= overhead) |
| 511 | goto pktlen_error; |
| 512 | |
| 513 | on = IP_PMTUDISC_DO; |
| 514 | if (setsockopt(fd, SOL_IP, IP_MTU_DISCOVER, &on, sizeof(on))) { |
| 515 | perror("IP_MTU_DISCOVER"); |
| 516 | exit(1); |
| 517 | } |
| 518 | on = 1; |
| 519 | if (setsockopt(fd, SOL_IP, IP_RECVERR, &on, sizeof(on))) { |
| 520 | perror("IP_RECVERR"); |
| 521 | exit(1); |
| 522 | } |
| 523 | if (setsockopt(fd, SOL_IP, IP_RECVTTL, &on, sizeof(on))) { |
| 524 | perror("IP_RECVTTL"); |
| 525 | exit(1); |
| 526 | } |
| 527 | } |
| 528 | |
| 529 | pktbuf = malloc(mtu); |
| 530 | if (!pktbuf) { |
| 531 | perror("malloc"); |
| 532 | exit(1); |
| 533 | } |
| 534 | |
| 535 | for (ttl = 1; ttl <= max_hops; ttl++) { |
| 536 | int res; |
| 537 | int i; |
| 538 | |
| 539 | on = ttl; |
| 540 | switch (family) { |
| 541 | case AF_INET6: |
| 542 | if (setsockopt(fd, SOL_IPV6, IPV6_UNICAST_HOPS, &on, sizeof(on))) { |
| 543 | perror("IPV6_UNICAST_HOPS"); |
| 544 | exit(1); |
| 545 | } |
| 546 | if (!mapped) |
| 547 | break; |
| 548 | /*FALLTHROUGH*/ |
| 549 | case AF_INET: |
| 550 | if (setsockopt(fd, SOL_IP, IP_TTL, &on, sizeof(on))) { |
| 551 | perror("IP_TTL"); |
| 552 | exit(1); |
| 553 | } |
| 554 | } |
| 555 | |
| 556 | restart: |
| 557 | for (i=0; i<3; i++) { |
| 558 | int old_mtu; |
| 559 | |
| 560 | old_mtu = mtu; |
| 561 | res = probe_ttl(fd, ttl); |
| 562 | if (mtu != old_mtu) |
| 563 | goto restart; |
| 564 | if (res == 0) |
| 565 | goto done; |
| 566 | if (res > 0) |
| 567 | break; |
| 568 | } |
| 569 | |
| 570 | if (res < 0) |
| 571 | printf("%2d: no reply\n", ttl); |
| 572 | } |
| 573 | printf(" Too many hops: pmtu %d\n", mtu); |
| 574 | |
| 575 | done: |
| 576 | printf(" Resume: pmtu %d ", mtu); |
| 577 | if (hops_to>=0) |
| 578 | printf("hops %d ", hops_to); |
| 579 | if (hops_from>=0) |
| 580 | printf("back %d ", hops_from); |
| 581 | printf("\n"); |
| 582 | exit(0); |
| 583 | |
| 584 | pktlen_error: |
| 585 | fprintf(stderr, "Error: pktlen must be > %d and <= %d\n", |
| 586 | overhead, INT_MAX); |
| 587 | exit(1); |
| 588 | } |