src/astraceroute.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2011 Daniel Borkmann.
   5  * Subject to the GPL, version 2.
   6  *
   7  * An Autonomous System trace route utility based on TCP instead of ICMP for
   8  * a better passing of firewalls. Supports IPv4 and IPv6. Based on the idea
   9  * of tcptraceroute (http://michael.toren.net/code/tcptraceroute/), but hacked
  10  * for Autonomous Systems tracing, thus you will know an approximate path of
  11  * your curvetun tunneled packets, for instance. However, astraceroute was
  12  * written from scratch and does not use any libraries. Special thanks to
  13  * Team CYMRU!
  14  *
  15  *   The road must be trod, but it will be very hard. And neither strength nor
  16  *   wisdom will carry us far upon it. This quest may be attempted by the weak
  17  *   with as much hope as the strong. Yet such is oft the course of deeds that
  18  *   move the wheels of the world: small hands do them because they must,
  19  *   while the eyes of the great are elsewhere.
  20  *
  21  *     -- The Lord of the Rings, Elrond, Chapter 'The Council of Elrond'.
  22  *
  23  * astraceroute includes GeoLite data created by MaxMind, available from
  24  * http://www.maxmind.com/. On Debian you need libgeoip-dev, libgeoip1 and
  25  * geoip-database-contrib.
  26  */
  27
  28 /*
  29
  30 =head1 NAME
  31
  32 astraceroute - Autonomous System (AS) trace route utility
  33
  34 =head1 SYNOPSIS
  35
  36 astraceroute    -H|--host <host> -i|-d|--dev <dev> [-6|--ipv6]
  37         [-n|--numeric] [-N|--dns] [-f|--init-ttl <ttl>]
  38         [-m|--max-ttl <ttl>] [-q|--num-probes] [-x|--timeout <sec>]
  39         [-S|--syn] [-A|--ack] [-F|--fin] [-P|--psh] [-U|--urg]
  40         [-R|--rst] [-E|--ecn-syn] [-t|--tos <tos>] [-G|--nofrag]
  41         [-X|--payload <string>] [-Z|--show-packet] [-l|--totlen <len>]
  42         [-w|--whois <server>] [-W|--wport <port>] [--city-db <path>]
  43         [--country-db <path>] [-v|--version] [-h|--help]
  44
  45 =head1 DESCRIPTION
  46
  47 This program provides AS information on each hop between the client
  48 and the target host.
  49
  50 =head1 OPTIONS
  51
  52 =over
  53
  54 =item astraceroute -i eth0 -N -E -H netsniff-ng.org
  55
  56 IPv4 trace of AS with TCP ECN SYN probe
  57
  58 =item astraceroute -i eth0 -N -S -H netsniff-ng.org
  59
  60 IPv4 trace of AS with TCP SYN probe
  61
  62 =item astraceroute -i eth0 -N -F -H netsniff-ng.org
  63
  64 IPv4 trace of AS with TCP FIN probe
  65
  66 =item astraceroute -i eth0 -N -FPU -H netsniff-ng.org
  67
  68 IPv4 trace of AS with Xmas probe
  69
  70 =item astraceroute -i eth0 -N -H netsniff-ng.org -X "censor-me" -Z
  71
  72 IPv4 trace of AS with Null probe with ASCII payload
  73
  74 =item astraceroute -6 -S -i eth0 -H netsniff-ng.org
  75
  76 IPv6 trace of AS up to netsniff-ng.org
  77
  78 =back
  79
  80 =head1 OPTIONS
  81
  82 =over
  83
  84 =item -h|--help
  85
  86 Print help text and lists all options.
  87
  88 =item -v|--version
  89
  90 Print version.
  91
  92 =item -H|--host <host>
  93
  94 Host/IPv4/IPv6 to lookup AS route to
  95
  96 =item i-|-d|--dev <netdev>
  97
  98 Networking device, i.e. eth0
  99
 100 =item -p|--port <port>
 101
 102 Hosts port to lookup AS route to
 103
 104 =item -4|--ipv4
 105
 106 Use IPv4 requests (default)
 107
 108 =item -6|--ipv6
 109
 110 Use IPv6 requests
 111
 112 =item -n|--numeric
 113
 114 Do not do reverse DNS lookup for hops
 115
 116 =item -N|--dns
 117
 118 Do a reverse DNS lookup for hops
 119
 120 =item -f|--init-ttl <ttl>
 121
 122 Set initial TTL
 123
 124 =item -m|--max-ttl <ttl>
 125
 126 Set maximum TTL (default: 30)
 127
 128 =item -q|--num-probes <num>
 129
 130 Number of max probes for each hop (default: 3)
 131
 132 =item -x|--timeout <sec>
 133
 134 Probe response timeout in sec (default: 3)
 135
 136 =item -S|--syn
 137
 138 Set TCP SYN flag in packets
 139
 140 =item -A|--ack
 141
 142 Set TCP ACK flag in packets
 143
 144 =item -F|--fin
 145
 146 Set TCP FIN flag in packets
 147
 148 =item -P|--psh
 149
 150 Set TCP PSH flag in packets
 151
 152 =item -U|--urg
 153
 154 Set TCP URG flag in packets
 155
 156 =item -R|--rst
 157
 158 Set TCP RST flag in packets
 159
 160 =item -E|--ecn-syn
 161
 162 Send ECN SYN packets (RFC3168)
 163
 164 =item -t|--tos <tos>
 165
 166 Set the IP TOS field
 167
 168 =item -w|--whois <server>
 169
 170 Use a different AS whois DB server
 171 (default: /etc/netsniff-ng/whois.conf)
 172
 173 =item -W|--wport <port>
 174
 175 Use a different port to AS whois server
 176 (default: /etc/netsniff-ng/whois.conf)
 177
 178 =item --city-db <path>
 179
 180 Specifiy path for geoip city database
 181
 182 =item --country-db <path>
 183
 184 Specifiy path for geoip country database
 185
 186 =back
 187
 188 =head1 AUTHOR
 189
 190 Written by Daniel Borkmann <daniel@netsniff-ng.org>
 191
 192 =head1 DOCUMENTATION
 193
 194 Documentation by Emmanuel Roullit <emmanuel@netsniff-ng.org>
 195
 196 =head1 BUGS
 197
 198 Please report bugs to <bugs@netsniff-ng.org>
 199
 200 =cut
 201
 202 */
 203
 204 #include <stdio.h>
 205 #include <stdlib.h>
 206 #include <signal.h>
 207 #include <getopt.h>
 208 #include <ctype.h>
 209 #include <stdint.h>
 210 #include <sys/types.h>
 211 #include <sys/stat.h>
 212 #include <sys/socket.h>
 213 #include <fcntl.h>
 214 #include <string.h>
 215 #include <asm/byteorder.h>
 216 #include <linux/tcp.h>
 217 #include <netinet/ip.h>
 218 #include <netinet/ip6.h>
 219 #include <netinet/in.h>
 220 #include <errno.h>
 221 #include <netdb.h>
 222 #include <arpa/inet.h>
 223 #include <linux/if_ether.h>
 224 #include <linux/icmp.h>
 225 #include <linux/icmpv6.h>
 226 #include <GeoIP.h>
 227 #include <GeoIPCity.h>
 228
 229 #include "bpf.h"
 230 #include "die.h"
 231 #include "tprintf.h"
 232 #include "pkt_buff.h"
 233 #include "proto.h"
 234 #include "xmalloc.h"
 235 #include "xio.h"
 236 #include "aslookup.h"
 237 #include "xutils.h"
 238 #include "mtrand.h"
 239 #include "ring_rx.h"
 240 #include "built_in.h"
 241
 242 #define WHOIS_SERVER_SOURCE "/etc/netsniff-ng/whois.conf"
 243
 244 static int assemble_ipv6_tcp(uint8_t *packet, size_t len, int ttl,
 245                              struct sockaddr_in *sin) __attribute__ ((unused));
 246
 247 struct ash_cfg {
 248         char *host;
 249         char *port;
 250         int init_ttl;
 251         int max_ttl;
 252         int dns_resolv;
 253         char *dev;
 254         int queries;
 255         int timeout;
 256         int syn, ack, ecn, fin, psh, rst, urg;
 257         int tos, nofrag;
 258         int totlen;
 259         char *whois;
 260         char *whois_port;
 261         int ip;
 262         char *payload;
 263 };
 264
 265 volatile sig_atomic_t sigint = 0;
 266
 267 static int show_pkt = 0;
 268
 269 static GeoIP *gi_country = NULL;
 270 static GeoIP *gi_city = NULL;
 271
 272 static const char *short_options = "H:p:nNf:m:i:d:q:x:SAEFPURt:Gl:w:W:hv46X:ZLK";
 273
 274 static struct option long_options[] = {
 275         {"host", required_argument, 0, 'H'},
 276         {"port", required_argument, 0, 'p'},
 277         {"init-ttl", required_argument, 0, 'f'},
 278         {"max-ttl", required_argument, 0, 'm'},
 279         {"numeric", no_argument, 0, 'n'},
 280         {"dns", no_argument, 0, 'N'},
 281         {"ipv4", no_argument, 0, '4'},
 282         {"ipv6", no_argument, 0, '6'},
 283         {"dev", required_argument, 0, 'd'},
 284         {"num-probes", required_argument, 0, 'q'},
 285         {"timeout", required_argument, 0, 'x'},
 286         {"syn", no_argument, 0, 'S'},
 287         {"ack", no_argument, 0, 'A'},
 288         {"urg", no_argument, 0, 'U'},
 289         {"fin", no_argument, 0, 'F'},
 290         {"psh", no_argument, 0, 'P'},
 291         {"rst", no_argument, 0, 'R'},
 292         {"ecn-syn", no_argument, 0, 'E'},
 293         {"tos", required_argument, 0, 't'},
 294         {"payload", required_argument, 0, 'X'},
 295         {"show-packet", no_argument, 0, 'Z'},
 296         {"nofrag", no_argument, 0, 'G'},
 297         {"totlen", required_argument, 0, 'l'},
 298         {"whois", required_argument, 0, 'w'},
 299         {"wport", required_argument, 0, 'W'},
 300         {"city-db", required_argument, 0, 'L'},
 301         {"country-db", required_argument, 0, 'K'},
 302         {"version", no_argument, 0, 'v'},
 303         {"help", no_argument, 0, 'h'},
 304         {0, 0, 0, 0}
 305 };
 306
 307 static struct sock_filter ipv4_icmp_type_11[] = {
 308         /* (000) ldh  [12] */
 309         { 0x28, 0, 0, 0x0000000c },
 310         /* (001) jeq  #0x800 jt 2 jf 10 */
 311         { 0x15, 0, 8, 0x00000800 },
 312         /* (002) ldb  [23] */
 313         { 0x30, 0, 0, 0x00000017 },
 314         /* (003) jeq  #0x1 jt 4 jf 10 */
 315         { 0x15, 0, 6, 0x00000001 },
 316         /* (004) ldh  [20] */
 317         { 0x28, 0, 0, 0x00000014 },
 318         /* (005) jset #0x1fff jt 10 jf 6 */
 319         { 0x45, 4, 0, 0x00001fff },
 320         /* (006) ldxb 4*([14]&0xf) */
 321         { 0xb1, 0, 0, 0x0000000e },
 322         /* (007) ldb  [x + 14] */
 323         { 0x50, 0, 0, 0x0000000e },
 324         /* (008) jeq  #0xb jt 9 jf 10 */
 325         { 0x15, 0, 1, 0x0000000b },
 326         /* (009) ret  #65535 */
 327         { 0x06, 0, 0, 0xffffffff },
 328         /* (010) ret  #0 */
 329         { 0x06, 0, 0, 0x00000000 },
 330 };
 331
 332 static struct sock_filter ipv6_icmp6_type_3[] = {
 333         /* (000) ldh [12] */
 334         { 0x28, 0, 0, 0x0000000c },
 335         /* (001) jeq  #0x86dd jt 2 jf 7 */
 336         { 0x15, 0, 5, 0x000086dd },
 337         /* (002) ldb  [20] */
 338         { 0x30, 0, 0, 0x00000014 },
 339         /* (003) jeq  #0x3a jt 4 jf 7 */
 340         { 0x15, 0, 3, 0x0000003a },
 341         /* (004) ldb  [54] */
 342         { 0x30, 0, 0, 0x00000036 },
 343         /* (005) jeq  #0x3 jt 6 jf 7 */
 344         { 0x15, 0, 1, 0x00000003 },
 345         /* (006) ret  #65535 */
 346         { 0x06, 0, 0, 0xffffffff },
 347         /* (007) ret  #0 */
 348         { 0x06, 0, 0, 0x00000000 },
 349 };
 350
 351 static void signal_handler(int number)
 352 {
 353         switch (number) {
 354         case SIGINT:
 355                 sigint = 1;
 356                 break;
 357         default:
 358                 break;
 359         }
 360 }
 361
 362 static void header(void)
 363 {
 364         printf("%s%s%s\n", colorize_start(bold), "astraceroute "
 365                VERSION_STRING, colorize_end());
 366 }
 367
 368 static void help(void)
 369 {
 370
 371         printf("\nastraceroute %s, Autonomous System (AS) trace route utility\n",
 372                VERSION_STRING);
 373         printf("http://www.netsniff-ng.org\n\n");
 374         printf("Usage: astraceroute [options]\n");
 375         printf("Options:\n");
 376         printf(" -H|--host <host>        Host/IPv4/IPv6 to lookup AS route to\n");
 377         printf(" -p|--port <port>        Hosts port to lookup AS route to\n");
 378         printf(" -i|-d|--dev <device>    Networking device, i.e. eth0\n");
 379         printf(" -4|--ipv4               Use IPv4 requests (default)\n");
 380         printf(" -6|--ipv6               Use IPv6 requests\n");
 381         printf(" -n|--numeric            Do not do reverse DNS lookup for hops\n");
 382         printf(" -N|--dns                Do a reverse DNS lookup for hops\n");
 383         printf(" -f|--init-ttl <ttl>     Set initial TTL\n");
 384         printf(" -m|--max-ttl <ttl>      Set maximum TTL (default: 30)\n");
 385         printf(" -q|--num-probes <num>   Number of max probes for each hop (default: 3)\n");
 386         printf(" -x|--timeout <sec>      Probe response timeout in sec (default: 3)\n");
 387         printf(" -S|--syn                Set TCP SYN flag in packets\n");
 388         printf(" -A|--ack                Set TCP ACK flag in packets\n");
 389         printf(" -F|--fin                Set TCP FIN flag in packets\n");
 390         printf(" -P|--psh                Set TCP PSH flag in packets\n");
 391         printf(" -U|--urg                Set TCP URG flag in packets\n");
 392         printf(" -R|--rst                Set TCP RST flag in packets\n");
 393         printf(" -E|--ecn-syn            Send ECN SYN packets (RFC3168)\n");
 394         printf(" -t|--tos <tos>          Set the IP TOS field\n");
 395         printf(" -G|--nofrag             Set do not fragment bit\n");
 396         printf(" -X|--payload <string>   Specify a payload string to test DPIs\n");
 397         printf(" -Z|--show-packet        Show returned packet on each hop\n");
 398         printf(" -l|--totlen <len>       Specify total packet len\n");
 399         printf(" -w|--whois <server>     Use a different AS whois DB server\n");
 400         printf("                         (default: /etc/netsniff-ng/whois.conf)\n");
 401         printf(" -W|--wport <port>       Use a different port to AS whois server\n");
 402         printf("                         (default: /etc/netsniff-ng/whois.conf)\n");
 403         printf(" --city-db <path>        Specifiy path for geoip city database\n");
 404         printf(" --country-db <path>     Specifiy path for geoip country database\n");
 405         printf(" -v|--version            Print version\n");
 406         printf(" -h|--help               Print this help\n");
 407         printf("\n");
 408         printf("Examples:\n");
 409         printf("  IPv4 trace of AS with TCP ECN SYN probe:\n");
 410         printf("    astraceroute -i eth0 -N -E -H netsniff-ng.org\n");
 411         printf("  IPv4 trace of AS with TCP SYN probe (this will most-likely pass):\n");
 412         printf("    astraceroute -i eth0 -N -S -H netsniff-ng.org\n");
 413         printf("  IPv4 trace of AS with TCP FIN probe:\n");
 414         printf("    astraceroute -i eth0 -N -F -H netsniff-ng.org\n");
 415         printf("  IPv4 trace of AS with Xmas probe:\n");
 416         printf("    astraceroute -i eth0 -N -FPU -H netsniff-ng.org\n");
 417         printf("  IPv4 trace of AS with Null probe with ASCII payload:\n");
 418         printf("    astraceroute -i eth0 -N -H netsniff-ng.org -X \"censor-me\" -Z\n");
 419         printf("  IPv6 trace of AS up to netsniff-ng.org:\n");
 420         printf("    astraceroute -6 -S -i eth0 -H netsniff-ng.org\n");
 421         printf("\n");
 422         printf("Note:\n");
 423         printf("  If the TCP probe did not give any results, then astraceroute will\n");
 424         printf("  automatically probe for classic ICMP packets! To gather more\n");
 425         printf("  information about astraceroute's fetched AS numbers, see i.e.\n");
 426         printf("  http://bgp.he.net/AS<number>!\n");
 427         printf("\n");
 428         printf("Please report bugs to <bugs@netsniff-ng.org>\n");
 429         printf("Copyright (C) 2011-2012 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,\n");
 430         printf("Swiss federal institute of technology (ETH Zurich)\n");
 431         printf("License: GNU GPL version 2\n");
 432         printf("This is free software: you are free to change and redistribute it.\n");
 433         printf("There is NO WARRANTY, to the extent permitted by law.\n\n");
 434         die();
 435 }
 436
 437 static void version(void)
 438 {
 439         printf("\nastraceroute %s, AS trace route utility\n",
 440                VERSION_STRING);
 441         printf("http://www.netsniff-ng.org\n\n");
 442         printf("Please report bugs to <bugs@netsniff-ng.org>\n");
 443         printf("Copyright (C) 2011-2012 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,\n");
 444         printf("Swiss federal institute of technology (ETH Zurich)\n");
 445         printf("License: GNU GPL version 2\n");
 446         printf("This is free software: you are free to change and redistribute it.\n");
 447         printf("There is NO WARRANTY, to the extent permitted by law.\n\n");
 448         die();
 449 }
 450
 451 static inline unsigned short csum(unsigned short *buf, int nwords)
 452 {
 453         unsigned long sum;
 454
 455         for (sum = 0; nwords > 0; nwords--)
 456                 sum += *buf++;
 457         sum = (sum >> 16) + (sum & 0xffff);
 458         sum += (sum >> 16);
 459
 460         return ~sum;
 461 }
 462
 463 static void assemble_data(uint8_t *packet, size_t len, const char *payload)
 464 {
 465         int i;
 466
 467         if (payload == NULL) {
 468                 for (i = 0; i < len; ++i)
 469                         packet[i] = (uint8_t) mt_rand_int32();
 470         } else {
 471                 int lmin = min(len, strlen(payload));
 472                 for (i = 0; i < lmin; ++i)
 473                         packet[i] = (uint8_t) payload[i];
 474                 for (i = lmin; i < len; ++i)
 475                         packet[i] = (uint8_t) mt_rand_int32();
 476         }
 477 }
 478
 479 static void assemble_tcp(uint8_t *packet, size_t len, int syn, int ack,
 480                          int urg, int fin, int rst, int psh, int ecn, int dport)
 481 {
 482         struct tcphdr *tcph = (struct tcphdr *) packet;
 483
 484         bug_on(len < sizeof(struct tcphdr));
 485
 486         tcph->source = htons((uint16_t) mt_rand_int32());
 487         tcph->dest = htons((uint16_t) dport);
 488         tcph->seq = htonl(mt_rand_int32());
 489         tcph->ack_seq = (!!ack ? htonl(mt_rand_int32()) : 0);
 490         tcph->doff = 5;
 491         tcph->syn = !!syn;
 492         tcph->ack = !!ack;
 493         tcph->urg = !!urg;
 494         tcph->fin = !!fin;
 495         tcph->rst = !!rst;
 496         tcph->psh = !!psh;
 497         tcph->ece = !!ecn;
 498         tcph->cwr = !!ecn;
 499         tcph->window = htons((uint16_t) (100 + (mt_rand_int32() % 65435)));
 500         tcph->check = 0;
 501         tcph->urg_ptr = (!!urg ? htons((uint16_t) mt_rand_int32()) :  0);
 502 }
 503
 504 /* returns: ipv4 id */
 505 static int assemble_ipv4_tcp(uint8_t *packet, size_t len, int ttl,
 506                              int tos, const struct sockaddr *dst,
 507                              const struct sockaddr *src, int syn, int ack,
 508                              int urg, int fin, int rst, int psh, int ecn,
 509                              int nofrag, int dport, const char *payload)
 510 {
 511         struct iphdr *iph = (struct iphdr *) packet;
 512
 513         bug_on(!src || !dst);
 514         bug_on(src->sa_family != PF_INET || dst->sa_family != PF_INET);
 515         bug_on(len < sizeof(struct iphdr) + sizeof(struct tcphdr));
 516
 517         iph->ihl = 5;
 518         iph->version = 4;
 519         iph->tos = (uint8_t) tos;
 520         iph->tot_len = htons((uint16_t) len);
 521         iph->id = htons((uint16_t) mt_rand_int32());
 522         iph->frag_off = nofrag ? IP_DF : 0;
 523         iph->ttl = (uint8_t) ttl;
 524         iph->protocol = 6; /* TCP */
 525         iph->saddr = ((const struct sockaddr_in *) src)->sin_addr.s_addr;
 526         iph->daddr = ((const struct sockaddr_in *) dst)->sin_addr.s_addr;
 527
 528         assemble_tcp(packet + sizeof(struct iphdr),
 529                      len - sizeof(struct iphdr), syn, ack, urg, fin, rst,
 530                      psh, ecn, dport);
 531
 532         assemble_data(packet + sizeof(struct iphdr) + sizeof(struct tcphdr),
 533                       len - sizeof(struct iphdr) - sizeof(struct tcphdr),
 534                       payload);
 535
 536         iph->check = csum((unsigned short *) packet,
 537                           ntohs(iph->tot_len) >> 1);
 538
 539         return ntohs(iph->id);
 540 }
 541
 542 /* returns: ipv6 flow label */
 543 static int assemble_ipv6_tcp(uint8_t *packet, size_t len, int ttl,
 544                              struct sockaddr_in *sin)
 545 {
 546         return 0;
 547 }
 548
 549 static void assemble_icmp4(uint8_t *packet, size_t len)
 550 {
 551         struct icmphdr *icmph = (struct icmphdr *) packet;
 552
 553         bug_on(len < sizeof(struct icmphdr));
 554
 555         icmph->type = ICMP_ECHO;
 556         icmph->code = 0;
 557         icmph->checksum = 0;
 558 }
 559
 560 /* returns: ipv4 id */
 561 static int assemble_ipv4_icmp4(uint8_t *packet, size_t len, int ttl,
 562                                int tos, const struct sockaddr *dst,
 563                                const struct sockaddr *src, int nofrag,
 564                                const char *payload)
 565 {
 566         struct iphdr *iph = (struct iphdr *) packet;
 567
 568         bug_on(!src || !dst);
 569         bug_on(src->sa_family != PF_INET || dst->sa_family != PF_INET);
 570         bug_on(len < sizeof(struct iphdr) + sizeof(struct tcphdr));
 571
 572         iph->ihl = 5;
 573         iph->version = 4;
 574         iph->tos = 0;
 575         iph->tot_len = htons((uint16_t) len);
 576         iph->id = htons((uint16_t) mt_rand_int32());
 577         iph->frag_off = nofrag ? IP_DF : 0;
 578         iph->ttl = (uint8_t) ttl;
 579         iph->protocol = 1; /* ICMP4 */
 580         iph->saddr = ((const struct sockaddr_in *) src)->sin_addr.s_addr;
 581         iph->daddr = ((const struct sockaddr_in *) dst)->sin_addr.s_addr;
 582
 583         assemble_icmp4(packet + sizeof(struct iphdr),
 584                        len - sizeof(struct iphdr));
 585
 586         assemble_data(packet + sizeof(struct iphdr) + sizeof(struct icmphdr),
 587                       len - sizeof(struct iphdr) - sizeof(struct icmphdr),
 588                       payload);
 589
 590         iph->check = csum((unsigned short *) packet,
 591                           ntohs(iph->tot_len) >> 1);
 592
 593         return ntohs(iph->id);
 594 }
 595
 596 static int assemble_packet_or_die(uint8_t *packet, size_t len, int ttl, int icmp,
 597                                   const struct ash_cfg *cfg,
 598                                   const struct sockaddr *dst,
 599                                   const struct sockaddr *src)
 600 {
 601         if (icmp)
 602                 return assemble_ipv4_icmp4(packet, len, ttl, cfg->tos, dst, src,
 603                                            cfg->nofrag, cfg->payload);
 604         else
 605                 return assemble_ipv4_tcp(packet, len, ttl, cfg->tos, dst, src,
 606                                          cfg->syn, cfg->ack, cfg->urg, cfg->fin,
 607                                          cfg->rst, cfg->psh, cfg->ecn,
 608                                          cfg->nofrag, atoi(cfg->port),
 609                                          cfg->payload);
 610 }
 611
 612 #define PKT_NOT_FOR_US  0
 613 #define PKT_GOOD        1
 614
 615 static inline const char *make_n_a(const char *p)
 616 {
 617         return p ? : "N/A";
 618 }
 619
 620 static int handle_ipv4_icmp(uint8_t *packet, size_t len, int ttl, int id,
 621                             const struct sockaddr *own, int dns_resolv)
 622 {
 623         int ret;
 624         struct iphdr *iph = (struct iphdr *) packet;
 625         struct iphdr *iph_inner;
 626         struct icmphdr *icmph;
 627         char *hbuff;
 628         struct sockaddr_in sa;
 629         struct asrecord rec;
 630         GeoIPRecord *gir;
 631
 632         if (iph->protocol != 1)
 633                 return PKT_NOT_FOR_US;
 634         if (iph->daddr != ((const struct sockaddr_in *) own)->sin_addr.s_addr)
 635                 return PKT_NOT_FOR_US;
 636
 637         icmph = (struct icmphdr *) (packet + sizeof(struct iphdr));
 638         if (icmph->type != ICMP_TIME_EXCEEDED)
 639                 return PKT_NOT_FOR_US;
 640         if (icmph->code != ICMP_EXC_TTL)
 641                 return PKT_NOT_FOR_US;
 642
 643         iph_inner = (struct iphdr *) (packet + sizeof(struct iphdr) +
 644                                       sizeof(struct icmphdr));
 645         if (ntohs(iph_inner->id) != id)
 646                 return PKT_NOT_FOR_US;
 647
 648         hbuff = xzmalloc(NI_MAXHOST);
 649
 650         memset(&sa, 0, sizeof(sa));
 651         sa.sin_family = PF_INET;
 652         sa.sin_addr.s_addr = iph->saddr;
 653
 654         getnameinfo((struct sockaddr *) &sa, sizeof(sa), hbuff, NI_MAXHOST,
 655                     NULL, 0, NI_NUMERICHOST);
 656
 657         memset(&rec, 0, sizeof(rec));
 658         ret = aslookup(hbuff, &rec);
 659         if (ret < 0)
 660                 panic("AS lookup error %d!\n", ret);
 661
 662         gir = GeoIP_record_by_ipnum(gi_city, ntohl(iph->saddr));
 663         if (!dns_resolv) {
 664                 if (strlen(rec.country) > 0 && gir) {
 665                         const char *city = make_n_a(gir->city);
 666
 667                         printf("%s in AS%s (%s, %s, %s, %f, %f), %s %s (%s), %s", hbuff,
 668                                rec.number, rec.country,
 669                                GeoIP_country_name_by_ipnum(gi_country, ntohl(iph->saddr)),
 670                                city, gir->latitude, gir->longitude,
 671                                rec.prefix, rec.registry, rec.since, rec.name);
 672                 } else if (strlen(rec.country) > 0 && !gir) {
 673                         printf("%s in AS%s (%s, %s), %s %s (%s), %s", hbuff,
 674                                rec.number, rec.country,
 675                                GeoIP_country_name_by_ipnum(gi_country, ntohl(iph->saddr)),
 676                                rec.prefix, rec.registry, rec.since, rec.name);
 677                 } else {
 678                         printf("%s in unkown AS", hbuff);
 679                 }
 680         } else {
 681                 struct hostent *hent = gethostbyaddr(&sa.sin_addr,
 682                                                      sizeof(sa.sin_addr),
 683                                                      PF_INET);
 684
 685                 if (strlen(rec.country) > 0 && gir) {
 686                         const char *city = make_n_a(gir->city);
 687                         printf("%s (%s) in AS%s (%s, %s, %s, %f, %f), %s %s (%s), %s",
 688                                (hent ? hent->h_name : hbuff), hbuff,
 689                                rec.number, rec.country,
 690                                GeoIP_country_name_by_ipnum(gi_country, ntohl(iph->saddr)),
 691                                city, gir->latitude, gir->longitude,
 692                                rec.prefix, rec.registry,
 693                                rec.since, rec.name);
 694                 } else if (strlen(rec.country) > 0 && !gir) {
 695                         printf("%s (%s) in AS%s (%s, %s), %s %s (%s), %s",
 696                                (hent ? hent->h_name : hbuff), hbuff,
 697                                rec.number, rec.country,
 698                                GeoIP_country_name_by_ipnum(gi_country, ntohl(iph->saddr)),
 699                                rec.prefix, rec.registry,
 700                                rec.since, rec.name);
 701                 } else {
 702                         printf("%s (%s) in unkown AS",
 703                                (hent ? hent->h_name : hbuff), hbuff);
 704                 }
 705         }
 706
 707         xfree(hbuff);
 708
 709         return PKT_GOOD;
 710 }
 711
 712 static int handle_packet(uint8_t *packet, size_t len, int ip, int ttl, int id,
 713                          struct sockaddr *own, int dns_resolv)
 714 {
 715         return handle_ipv4_icmp(packet, len, ttl, id, own, dns_resolv);
 716 }
 717
 718 static int do_trace(const struct ash_cfg *cfg)
 719 {
 720         int ttl, query, fd = -1, one = 1, ret, fd_cap, ifindex;
 721         int is_okay = 0, id, timeout_poll;
 722         uint8_t *packet, *packet_rcv;
 723         ssize_t err, real_len;
 724         size_t len, len_rcv;
 725         struct addrinfo hints, *ahead, *ai;
 726         char *hbuff1, *hbuff2;
 727         struct sockaddr_storage ss, sd;
 728         struct sock_fprog bpf_ops;
 729         struct ring dummy_ring;
 730         struct pollfd pfd;
 731
 732         mt_init_by_random_device();
 733
 734         memset(&hints, 0, sizeof(hints));
 735         hints.ai_family = PF_UNSPEC;
 736         hints.ai_socktype = SOCK_STREAM;
 737         hints.ai_protocol = IPPROTO_TCP;
 738         hints.ai_flags = AI_NUMERICSERV;
 739
 740         ret = getaddrinfo(cfg->host, cfg->port, &hints, &ahead);
 741         if (ret < 0) {
 742                 whine("Cannot get address info!\n");
 743                 return -EIO;
 744         }
 745
 746         for (ai = ahead; ai != NULL && fd < 0; ai = ai->ai_next) {
 747                 if (!((ai->ai_family == PF_INET6 && cfg->ip == 6) ||
 748                       (ai->ai_family == PF_INET && cfg->ip == 4)))
 749                         continue;
 750                 fd = socket(ai->ai_family, SOCK_RAW, ai->ai_protocol);
 751                 if (fd < 0)
 752                         continue;
 753
 754                 fd_cap = pf_socket();
 755
 756                 memset(&ss, 0, sizeof(ss));
 757                 ret = device_address(cfg->dev, ai->ai_family, &ss);
 758                 if (ret < 0)
 759                         panic("Cannot get own device address!\n");
 760
 761                 ret = bind(fd, (struct sockaddr *) &ss, sizeof(ss));
 762                 if (ret < 0)
 763                         panic("Cannot bind socket!\n");
 764
 765                 memset(&sd, 0, sizeof(sd));
 766                 memcpy(&sd, ai->ai_addr, ai->ai_addrlen);
 767
 768                 break;
 769         }
 770
 771         freeaddrinfo(ahead);
 772
 773         if (fd < 0) {
 774                 whine("Cannot create socket! Does remote support IPv%d?!\n",
 775                       cfg->ip);
 776                 return -EIO;
 777         }
 778
 779         len = cfg->totlen;
 780         if (cfg->ip == 4) {
 781                 if (len < sizeof(struct iphdr) + sizeof(struct tcphdr)) {
 782                         len = sizeof(struct iphdr) + sizeof(struct tcphdr);
 783                         if (cfg->payload)
 784                                 len += strlen(cfg->payload);
 785                 }
 786         } else {
 787                 if (len < sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) {
 788                         len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
 789                         if (cfg->payload)
 790                                 len += strlen(cfg->payload);
 791                 }
 792         }
 793
 794         if (len >= device_mtu(cfg->dev))
 795                 panic("Packet len exceeds device MTU!\n");
 796
 797         packet = xmalloc(len);
 798         len_rcv = device_mtu(cfg->dev);
 799         packet_rcv = xmalloc(len_rcv);
 800
 801         hbuff1 = xzmalloc(256);
 802         getnameinfo((struct sockaddr *) &sd, sizeof(sd), hbuff1, 256,
 803                     NULL, 0, NI_NUMERICHOST);
 804
 805         hbuff2 = xzmalloc(256);
 806         getnameinfo((struct sockaddr *) &ss, sizeof(ss), hbuff2, 256,
 807                     NULL, 0, NI_NUMERICHOST);
 808
 809         ret = setsockopt(fd, cfg->ip == 4 ? IPPROTO_IP : IPPROTO_IPV6,
 810                          IP_HDRINCL, &one, sizeof(one));
 811         if (ret < 0)
 812                 panic("Kernel does not support IP_HDRINCL!\n");
 813
 814         printf("AS path IPv%d TCP trace from %s to %s:%s (%s) with len %zu "
 815                "Bytes, %u max hops\n", cfg->ip, hbuff2, hbuff1, cfg->port,
 816                cfg->host, len, cfg->max_ttl);
 817
 818         printf("Using flags SYN:%d,ACK:%d,ECN:%d,FIN:%d,PSH:%d,RST:%d,URG:%d\n",
 819                cfg->syn, cfg->ack, cfg->ecn, cfg->fin, cfg->psh, cfg->rst,
 820                cfg->urg);
 821
 822         if (cfg->payload)
 823                 printf("With payload: \'%s\'\n", cfg->payload);
 824
 825         fflush(stdout);
 826
 827         xfree(hbuff1);
 828         xfree(hbuff2);
 829
 830         hbuff1 = hbuff2 = NULL;
 831
 832         enable_kernel_bpf_jit_compiler();
 833
 834         memset(&bpf_ops, 0, sizeof(bpf_ops));
 835         if (cfg->ip == 4) {
 836                 bpf_ops.filter = ipv4_icmp_type_11;
 837                 bpf_ops.len = (sizeof(ipv4_icmp_type_11) /
 838                                sizeof(ipv4_icmp_type_11[0]));
 839         } else {
 840                 bpf_ops.filter = ipv6_icmp6_type_3;
 841                 bpf_ops.len = (sizeof(ipv6_icmp6_type_3) /
 842                                sizeof(ipv6_icmp6_type_3[0]));
 843         }
 844
 845         bpf_attach_to_sock(fd_cap, &bpf_ops);
 846         ifindex = device_ifindex(cfg->dev);
 847         bind_rx_ring(fd_cap, &dummy_ring, ifindex);
 848         prepare_polling(fd_cap, &pfd);
 849
 850         timeout_poll = (cfg->timeout > 0 ? cfg->timeout : 3) * 1000;
 851
 852         for (ttl = cfg->init_ttl; ttl <= cfg->max_ttl; ++ttl) {
 853                 int icmp = 0;
 854                 is_okay = 0;
 855
 856                 if ((ttl == cfg->init_ttl && !show_pkt) ||
 857                     (ttl > cfg->init_ttl)) {
 858                         printf("%2d: ", ttl);
 859                         fflush(stdout);
 860                 }
 861 retry:
 862                 for (query = 0; query < cfg->queries && !is_okay; ++query) {
 863                         id = assemble_packet_or_die(packet, len, ttl, icmp, cfg,
 864                                                     (struct sockaddr *) &sd,
 865                                                     (struct sockaddr *) &ss);
 866                         if (ttl == cfg->init_ttl && query == 0 && show_pkt) {
 867                                 struct pkt_buff *pkt;
 868
 869                                 printf("Original packet:\n");
 870
 871                                 pkt = pkt_alloc(packet, len);
 872                                 hex_ascii(pkt);
 873                                 tprintf_flush();
 874                                 pkt_free(pkt);
 875
 876                                 printf("\n%2d: ", ttl);
 877                                 fflush(stdout);
 878                         }
 879
 880                         err = sendto(fd, packet, len, 0, (struct sockaddr *) &sd,
 881                                      sizeof(sd));
 882                         if (err < 0)
 883                                 panic("sendto failed: %s\n", strerror(errno));
 884
 885                         err = poll(&pfd, 1, timeout_poll);
 886                         if (err > 0 && pfd.revents & POLLIN) {
 887                                 real_len = recvfrom(fd_cap, packet_rcv, len_rcv,
 888                                                     0, NULL, NULL);
 889                                 if (real_len < sizeof(struct ethhdr) +
 890                                     (cfg->ip ? sizeof(struct iphdr) +
 891                                                sizeof(struct icmphdr) :
 892                                                sizeof(struct ip6_hdr) +
 893                                                sizeof(struct icmp6hdr)))
 894                                         continue;
 895
 896                                 is_okay = handle_packet(packet_rcv + sizeof(struct ethhdr),
 897                                                         real_len - sizeof(struct ethhdr),
 898                                                         cfg->ip, ttl, id,
 899                                                         (struct sockaddr *) &ss,
 900                                                         cfg->dns_resolv);
 901                                 if (is_okay && show_pkt) {
 902                                         struct pkt_buff *pkt;
 903
 904                                         printf("\n  Received packet:\n");
 905
 906                                         pkt = pkt_alloc(packet_rcv, real_len);
 907                                         hex_ascii(pkt);
 908                                         tprintf_flush();
 909                                         pkt_free(pkt);
 910                                 }
 911                         } else {
 912                                 printf("* ");
 913                                 fflush(stdout);
 914                                 is_okay = 0;
 915                         }
 916                 }
 917
 918                 if (is_okay == 0 && icmp == 0) {
 919                         icmp = 1;
 920                         goto retry;
 921                 }
 922
 923                 printf("\n");
 924                 fflush(stdout);
 925         }
 926
 927         close(fd_cap);
 928         close(fd);
 929
 930         xfree(packet);
 931         xfree(packet_rcv);
 932
 933         return 0;
 934 }
 935
 936 static void parse_whois_or_die(struct ash_cfg *cfg)
 937 {
 938         int fd;
 939         ssize_t ret;
 940         char tmp[512], *ptr, *ptr2;
 941
 942         fd = open_or_die(WHOIS_SERVER_SOURCE, O_RDONLY);
 943
 944         while ((ret = read(fd, tmp, sizeof(tmp))) > 0) {
 945                 tmp[sizeof(tmp) - 1] = 0;
 946                 ptr = skips(tmp);
 947                 ptr2 = ptr;
 948                 while (*ptr2 != ' ' && ptr2 < &tmp[sizeof(tmp) - 1])
 949                         ptr2++;
 950                 if (*ptr2 != ' ')
 951                         panic("Parser error!\n");
 952                 *ptr2 = 0;
 953                 cfg->whois = xstrdup(ptr);
 954                 ptr = ptr2 + 1;
 955                 if (ptr >= &tmp[sizeof(tmp) - 1])
 956                         panic("Parser error!\n");
 957                 ptr = skips(ptr);
 958                 ptr[strlen(ptr) - 1] = 0;
 959                 cfg->whois_port = xstrdup(ptr);
 960                 break;
 961         }
 962
 963         close(fd);
 964 }
 965
 966 int main(int argc, char **argv)
 967 {
 968         int c, opt_index, ret;
 969         struct ash_cfg cfg;
 970         char *path_city_db = NULL, *path_country_db = NULL;
 971
 972         check_for_root_maybe_die();
 973
 974         memset(&cfg, 0, sizeof(cfg));
 975         cfg.init_ttl = 1;
 976         cfg.max_ttl = 30;
 977         cfg.queries = 3;
 978         cfg.timeout = 3;
 979         cfg.ip = 4;
 980         cfg.payload = NULL;
 981         cfg.dev = xstrdup("eth0");
 982         cfg.port = xstrdup("80");
 983
 984         while ((c = getopt_long(argc, argv, short_options, long_options,
 985                 &opt_index)) != EOF) {
 986                 switch (c) {
 987                 case 'h':
 988                         help();
 989                         break;
 990                 case 'v':
 991                         version();
 992                         break;
 993                 case 'H':
 994                         cfg.host = xstrdup(optarg);
 995                         break;
 996                 case 'p':
 997                         if (cfg.port)
 998                                 xfree(cfg.port);
 999                         cfg.port = xstrdup(optarg);
1000                         break;
1001                 case 'n':
1002                         cfg.dns_resolv = 0;
1003                         break;
1004                 case '4':
1005                         cfg.ip = 4;
1006                         break;
1007                 case '6':
1008                         cfg.ip = 6;
1009                         break;
1010                 case 'Z':
1011                         show_pkt = 1;
1012                         break;
1013                 case 'N':
1014                         cfg.dns_resolv = 1;
1015                         break;
1016                 case 'f':
1017                         cfg.init_ttl = atoi(optarg);
1018                         if (cfg.init_ttl <= 0)
1019                                 help();
1020                         break;
1021                 case 'm':
1022                         cfg.max_ttl = atoi(optarg);
1023                         if (cfg.max_ttl <= 0)
1024                                 help();
1025                         break;
1026                 case 'i':
1027                 case 'd':
1028                         if (cfg.dev)
1029                                 xfree(cfg.dev);
1030                         cfg.dev = xstrdup(optarg);
1031                         break;
1032                 case 'q':
1033                         cfg.queries = atoi(optarg);
1034                         if (cfg.queries <= 0)
1035                                 help();
1036                         break;
1037                 case 'x':
1038                         cfg.timeout = atoi(optarg);
1039                         if (cfg.timeout <= 0)
1040                                 help();
1041                         break;
1042                 case 'S':
1043                         cfg.syn = 1;
1044                         break;
1045                 case 'A':
1046                         cfg.ack = 1;
1047                         break;
1048                 case 'F':
1049                         cfg.fin = 1;
1050                         break;
1051                 case 'U':
1052                         cfg.urg = 1;
1053                         break;
1054                 case 'P':
1055                         cfg.psh = 1;
1056                         break;
1057                 case 'R':
1058                         cfg.rst = 1;
1059                         break;
1060                 case 'E':
1061                         cfg.syn = 1;
1062                         cfg.ecn = 1;
1063                         break;
1064                 case 't':
1065                         cfg.tos = atoi(optarg);
1066                         if (cfg.tos < 0)
1067                                 help();
1068                         break;
1069                 case 'G':
1070                         cfg.nofrag = 1;
1071                         break;
1072                 case 'X':
1073                         cfg.payload = xstrdup(optarg);
1074                         break;
1075                 case 'l':
1076                         cfg.totlen = atoi(optarg);
1077                         if (cfg.totlen <= 0)
1078                                 help();
1079                         break;
1080                 case 'w':
1081                         cfg.whois = xstrdup(optarg);
1082                         break;
1083                 case 'W':
1084                         cfg.whois_port = xstrdup(optarg);
1085                         break;
1086                 case 'L':
1087                         path_city_db = xstrdup(optarg);
1088                         break;
1089                 case 'K':
1090                         path_country_db = xstrdup(optarg);
1091                         break;
1092                 case '?':
1093                         switch (optopt) {
1094                         case 'H':
1095                         case 'p':
1096                         case 'L':
1097                         case 'K':
1098                         case 'f':
1099                         case 'm':
1100                         case 'i':
1101                         case 'd':
1102                         case 'q':
1103                         case 'x':
1104                         case 'X':
1105                         case 't':
1106                         case 'l':
1107                         case 'w':
1108                         case 'W':
1109                                 panic("Option -%c requires an argument!\n",
1110                                       optopt);
1111                         default:
1112                                 if (isprint(optopt))
1113                                         whine("Unknown option character "
1114                                               "`0x%X\'!\n", optopt);
1115                                 die();
1116                 }
1117                 default:
1118                         break;
1119                 }
1120         }
1121
1122         if (argc < 3 ||
1123             !cfg.host || !cfg.port ||
1124             cfg.init_ttl > cfg.max_ttl ||
1125             cfg.init_ttl > MAXTTL ||
1126             cfg.max_ttl > MAXTTL)
1127                 help();
1128
1129         if (!device_up_and_running(cfg.dev))
1130                 panic("Networking device not up and running!\n");
1131         if (!cfg.whois || !cfg.whois_port)
1132                 parse_whois_or_die(&cfg);
1133         if (device_mtu(cfg.dev) <= cfg.totlen)
1134                 panic("Packet larger than device MTU!\n");
1135
1136         register_signal(SIGHUP, signal_handler);
1137
1138         header();
1139
1140         tprintf_init();
1141
1142         ret = aslookup_prepare(cfg.whois, cfg.whois_port);
1143         if (ret < 0)
1144                 panic("Cannot resolve whois server!\n");
1145
1146         if (path_country_db)
1147                 gi_country = GeoIP_open(path_country_db, GEOIP_MMAP_CACHE);
1148         else
1149                 gi_country = GeoIP_open_type(GEOIP_COUNTRY_EDITION,
1150                                              GEOIP_MMAP_CACHE);
1151
1152         if (path_city_db)
1153                 gi_city = GeoIP_open(path_city_db, GEOIP_MMAP_CACHE);
1154         else
1155                 gi_city = GeoIP_open_type(GEOIP_CITY_EDITION_REV1,
1156                                           GEOIP_MMAP_CACHE);
1157
1158         if (!gi_country || !gi_city)
1159                 panic("Cannot open GeoIP database! Wrong path?!\n");
1160
1161         GeoIP_set_charset(gi_country, GEOIP_CHARSET_UTF8);
1162         GeoIP_set_charset(gi_city, GEOIP_CHARSET_UTF8);
1163
1164         ret = do_trace(&cfg);
1165
1166         GeoIP_delete(gi_city);
1167         GeoIP_delete(gi_country);
1168
1169         tprintf_cleanup();
1170
1171         free(cfg.whois_port);
1172         free(cfg.whois);
1173         free(cfg.dev);
1174         free(cfg.host);
1175         free(cfg.port);
1176         free(cfg.payload);
1177         free(path_city_db);
1178         free(path_country_db);
1179
1180         return ret;
1181 }