astraceroute.c

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * Copyright 2011 - 2013 Daniel Borkmann.
   4  * Subject to the GPL, version 2.
   5  */
   6
   7 #define _BSD_SOURCE
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <signal.h>
  11 #include <getopt.h>
  12 #include <ctype.h>
  13 #include <stdint.h>
  14 #include <sys/types.h>
  15 #include <sys/stat.h>
  16 #include <sys/socket.h>
  17 #include <sys/fsuid.h>
  18 #include <fcntl.h>
  19 #include <time.h>
  20 #include <string.h>
  21 #include <asm/byteorder.h>
  22 #include <linux/tcp.h>
  23 #include <netinet/ip.h>
  24 #include <netinet/ip6.h>
  25 #include <netinet/in.h>
  26 #include <errno.h>
  27 #include <netdb.h>
  28 #include <sys/time.h>
  29 #include <arpa/inet.h>
  30 #include <linux/if_ether.h>
  31 #include <linux/icmp.h>
  32 #include <linux/icmpv6.h>
  33
  34 #include "bpf.h"
  35 #include "die.h"
  36 #include "dev.h"
  37 #include "sig.h"
  38 #include "config.h"
  39 #include "tprintf.h"
  40 #include "pkt_buff.h"
  41 #include "proto.h"
  42 #include "xmalloc.h"
  43 #include "csum.h"
  44 #include "sock.h"
  45 #include "geoip.h"
  46 #include "ring.h"
  47 #include "built_in.h"
  48
  49 struct ctx {
  50         char *host, *port, *dev, *payload, *bind_addr;
  51         size_t totlen, rcvlen;
  52         int init_ttl, max_ttl, dns_resolv, queries, timeout;
  53         int syn, ack, ecn, fin, psh, rst, urg, tos, nofrag, proto, show;
  54         int sd_len, dport, latitude;
  55 };
  56
  57 struct proto_ops {
  58         int (*assembler)(uint8_t *packet, size_t len, int ttl, int proto,
  59                          const struct ctx *ctx, const struct sockaddr *dst,
  60                          const struct sockaddr *src);
  61         const struct sock_filter *filter;
  62         unsigned int flen;
  63         size_t min_len_tcp, min_len_icmp;
  64         int (*check)(uint8_t *packet, size_t len, int ttl, int id,
  65                      const struct sockaddr *src);
  66         void (*handler)(uint8_t *packet, size_t len, int dns_resolv,
  67                         int latitude);
  68 };
  69
  70 static sig_atomic_t sigint = 0;
  71
  72 static int assemble_ipv4(uint8_t *packet, size_t len, int ttl, int proto,
  73                          const struct ctx *ctx, const struct sockaddr *dst,
  74                          const struct sockaddr *src);
  75 static int assemble_ipv6(uint8_t *packet, size_t len, int ttl, int proto,
  76                          const struct ctx *ctx, const struct sockaddr *dst,
  77                          const struct sockaddr *src);
  78 static int check_ipv4(uint8_t *packet, size_t len, int ttl, int id,
  79                       const struct sockaddr *ss);
  80 static void handle_ipv4(uint8_t *packet, size_t len, int dns_resolv,
  81                         int latitude);
  82 static int check_ipv6(uint8_t *packet, size_t len, int ttl, int id,
  83                       const struct sockaddr *ss);
  84 static void handle_ipv6(uint8_t *packet, size_t len, int dns_resolv,
  85                         int latitude);
  86
  87 static const char *short_options = "H:p:nNf:m:b:i:d:q:x:SAEFPURt:Gl:hv46X:ZuL";
  88 static const struct option long_options[] = {
  89         {"host",        required_argument,      NULL, 'H'},
  90         {"port",        required_argument,      NULL, 'p'},
  91         {"init-ttl",    required_argument,      NULL, 'f'},
  92         {"max-ttl",     required_argument,      NULL, 'm'},
  93         {"bind",        required_argument,      NULL, 'b'},
  94         {"dev",         required_argument,      NULL, 'd'},
  95         {"num-probes",  required_argument,      NULL, 'q'},
  96         {"timeout",     required_argument,      NULL, 'x'},
  97         {"tos",         required_argument,      NULL, 't'},
  98         {"payload",     required_argument,      NULL, 'X'},
  99         {"totlen",      required_argument,      NULL, 'l'},
 100         {"numeric",     no_argument,            NULL, 'n'},
 101         {"latitude",    no_argument,            NULL, 'L'},
 102         {"update",      no_argument,            NULL, 'u'},
 103         {"dns",         no_argument,            NULL, 'N'},
 104         {"ipv4",        no_argument,            NULL, '4'},
 105         {"ipv6",        no_argument,            NULL, '6'},
 106         {"syn",         no_argument,            NULL, 'S'},
 107         {"ack",         no_argument,            NULL, 'A'},
 108         {"urg",         no_argument,            NULL, 'U'},
 109         {"fin",         no_argument,            NULL, 'F'},
 110         {"psh",         no_argument,            NULL, 'P'},
 111         {"rst",         no_argument,            NULL, 'R'},
 112         {"ecn-syn",     no_argument,            NULL, 'E'},
 113         {"show-packet", no_argument,            NULL, 'Z'},
 114         {"nofrag",      no_argument,            NULL, 'G'},
 115         {"version",     no_argument,            NULL, 'v'},
 116         {"help",        no_argument,            NULL, 'h'},
 117         {NULL, 0, NULL, 0}
 118 };
 119
 120 static const char *copyright = "Please report bugs to <bugs@netsniff-ng.org>\n"
 121         "Copyright (C) 2011-2013 Daniel Borkmann <dborkma@tik.ee.ethz.ch>\n"
 122         "Swiss federal institute of technology (ETH Zurich)\n"
 123         "License: GNU GPL version 2.0\n"
 124         "This is free software: you are free to change and redistribute it.\n"
 125         "There is NO WARRANTY, to the extent permitted by law.";
 126
 127 static const struct sock_filter ipv4_icmp_type_11[] = {
 128         { 0x28, 0, 0, 0x0000000c },     /* ldh [12]             */
 129         { 0x15, 0, 8, 0x00000800 },     /* jneq #0x800, drop    */
 130         { 0x30, 0, 0, 0x00000017 },     /* ldb [23]             */
 131         { 0x15, 0, 6, 0x00000001 },     /* jneq #0x1, drop      */
 132         { 0x28, 0, 0, 0x00000014 },     /* ldh [20]             */
 133         { 0x45, 4, 0, 0x00001fff },     /* jset #0x1fff, drop   */
 134         { 0xb1, 0, 0, 0x0000000e },     /* ldxb 4*([14]&0xf)    */
 135         { 0x50, 0, 0, 0x0000000e },     /* ldb [x + 14]         */
 136         { 0x15, 0, 1, 0x0000000b },     /* jneq #0xb, drop      */
 137         { 0x06, 0, 0, 0xffffffff },     /* ret #-1              */
 138         { 0x06, 0, 0, 0x00000000 },     /* drop: ret #0         */
 139 };
 140
 141 static const struct sock_filter ipv6_icmp6_type_3[] = {
 142         { 0x28, 0, 0, 0x0000000c },     /* ldh [12]             */
 143         { 0x15, 0, 5, 0x000086dd },     /* jneq #0x86dd, drop   */
 144         { 0x30, 0, 0, 0x00000014 },     /* ldb [20]             */
 145         { 0x15, 0, 3, 0x0000003a },     /* jneq #0x3a, drop     */
 146         { 0x30, 0, 0, 0x00000036 },     /* ldb [54]             */
 147         { 0x15, 0, 1, 0x00000003 },     /* jneq #0x3, drop      */
 148         { 0x06, 0, 0, 0xffffffff },     /* ret #-1              */
 149         { 0x06, 0, 0, 0x00000000 },     /* drop: ret #0         */
 150 };
 151
 152 static const struct proto_ops af_ops[] = {
 153         [IPPROTO_IP]    =       {
 154                         .assembler      =       assemble_ipv4,
 155                         .handler        =       handle_ipv4,
 156                         .check          =       check_ipv4,
 157                         .filter         =       ipv4_icmp_type_11,
 158                         .flen           =       array_size(ipv4_icmp_type_11),
 159                         .min_len_tcp    =       sizeof(struct iphdr) + sizeof(struct tcphdr),
 160                         .min_len_icmp   =       sizeof(struct iphdr) + sizeof(struct icmphdr),
 161                 },
 162         [IPPROTO_IPV6]  =       {
 163                         .assembler      =       assemble_ipv6,
 164                         .handler        =       handle_ipv6,
 165                         .check          =       check_ipv6,
 166                         .filter         =       ipv6_icmp6_type_3,
 167                         .flen           =       array_size(ipv6_icmp6_type_3),
 168                         .min_len_tcp    =       sizeof(struct ip6_hdr) + sizeof(struct tcphdr),
 169                         .min_len_icmp   =       sizeof(struct ip6_hdr) + sizeof(struct icmp6hdr),
 170                 },
 171 };
 172
 173 static void signal_handler(int number)
 174 {
 175         switch (number) {
 176         case SIGINT:
 177         case SIGQUIT:
 178         case SIGTERM:
 179                 sigint = 1;
 180         default:
 181                 break;
 182         }
 183 }
 184
 185 static void __noreturn help(void)
 186 {
 187         printf("astraceroute %s, autonomous system trace route utility\n", VERSION_STRING);
 188         puts("http://www.netsniff-ng.org\n\n"
 189              "Usage: astraceroute [options]\n"
 190              "Options:\n"
 191              " -H|--host <host>        Host/IPv4/IPv6 to lookup AS route to\n"
 192              " -p|--port <port>        Hosts port to lookup AS route to\n"
 193              " -i|-d|--dev <device>    Networking device, e.g. eth0\n"
 194              " -b|--bind <IP>          IP address to bind to, Must specify -6 for an IPv6 address\n"
 195              " -f|--init-ttl <ttl>     Set initial TTL\n"
 196              " -m|--max-ttl <ttl>      Set maximum TTL (def: 30)\n"
 197              " -q|--num-probes <num>   Number of max probes for each hop (def: 2)\n"
 198              " -x|--timeout <sec>      Probe response timeout in sec (def: 3)\n"
 199              " -X|--payload <string>   Specify a payload string to test DPIs\n"
 200              " -l|--totlen <len>       Specify total packet len\n"
 201              " -4|--ipv4               Use IPv4-only requests\n"
 202              " -6|--ipv6               Use IPv6-only requests\n"
 203              " -n|--numeric            Do not do reverse DNS lookup for hops\n"
 204              " -u|--update             Update GeoIP databases\n"
 205              " -L|--latitude           Show latitude and longitude\n"
 206              " -N|--dns                Do a reverse DNS lookup for hops\n"
 207              " -S|--syn                Set TCP SYN flag\n"
 208              " -A|--ack                Set TCP ACK flag\n"
 209              " -F|--fin                Set TCP FIN flag\n"
 210              " -P|--psh                Set TCP PSH flag\n"
 211              " -U|--urg                Set TCP URG flag\n"
 212              " -R|--rst                Set TCP RST flag\n"
 213              " -E|--ecn-syn            Send ECN SYN packets (RFC3168)\n"
 214              " -t|--tos <tos>          Set the IP TOS field\n"
 215              " -G|--nofrag             Set do not fragment bit\n"
 216              " -Z|--show-packet        Show returned packet on each hop\n"
 217              " -v|--version            Print version and exit\n"
 218              " -h|--help               Print this help and exit\n\n"
 219              "Examples:\n"
 220              "  IPv4 trace of AS with TCP SYN probe (this will most-likely pass):\n"
 221              "    astraceroute -i eth0 -N -S -H netsniff-ng.org\n"
 222              "  IPv4 trace of AS with TCP ECN SYN probe:\n"
 223              "    astraceroute -i eth0 -N -E -H netsniff-ng.org\n"
 224              "  IPv4 trace of AS with TCP FIN probe:\n"
 225              "    astraceroute -i eth0 -N -F -H netsniff-ng.org\n"
 226              "  IPv4 trace of AS with Xmas probe:\n"
 227              "    astraceroute -i eth0 -N -FPU -H netsniff-ng.org\n"
 228              "  IPv4 trace of AS with Null probe with ASCII payload:\n"
 229              "    astraceroute -i eth0 -N -H netsniff-ng.org -X \"censor-me\" -Z\n"
 230              "  IPv6 trace of AS up to www.6bone.net:\n"
 231              "    astraceroute -6 -i eth0 -S -E -N -H www.6bone.net\n\n"
 232              "Note:\n"
 233              "  If the TCP probe did not give any results, then astraceroute will\n"
 234              "  automatically probe for classic ICMP packets! To gather more\n"
 235              "  information about astraceroute's fetched AS numbers, see e.g.\n"
 236              "  http://bgp.he.net/AS<number>!\n");
 237         puts(copyright);
 238         die();
 239 }
 240
 241 static void __noreturn version(void)
 242 {
 243         printf("astraceroute %s, Git id: %s\n", VERSION_LONG, GITVERSION);
 244         puts("autonomous system trace route utility\n"
 245              "http://www.netsniff-ng.org\n");
 246         puts(copyright);
 247         die();
 248 }
 249
 250 static void __assemble_data(uint8_t *packet, size_t len, const char *payload)
 251 {
 252         size_t i;
 253
 254         if (payload == NULL) {
 255                 for (i = 0; i < len; ++i)
 256                         packet[i] = (uint8_t) rand();
 257         } else {
 258                 size_t lmin = min(len, strlen(payload));
 259
 260                 for (i = 0; i < lmin; ++i)
 261                         packet[i] = (uint8_t) payload[i];
 262                 for (i = lmin; i < len; ++i)
 263                         packet[i] = (uint8_t) rand();
 264         }
 265 }
 266
 267 static void __assemble_icmp4(uint8_t *packet, size_t len)
 268 {
 269         struct icmphdr *icmph = (struct icmphdr *) packet;
 270
 271         bug_on(len < sizeof(struct icmphdr));
 272
 273         icmph->type = ICMP_ECHO;
 274         icmph->code = 0;
 275         icmph->checksum = 0;
 276 }
 277
 278 static void __assemble_icmp6(uint8_t *packet, size_t len)
 279 {
 280         struct icmp6hdr *icmp6h = (struct icmp6hdr *) packet;
 281
 282         bug_on(len < sizeof(struct icmp6hdr));
 283
 284         icmp6h->icmp6_type = ICMPV6_ECHO_REQUEST;
 285         icmp6h->icmp6_code = 0;
 286         icmp6h->icmp6_cksum = 0;
 287 }
 288
 289 static void __assemble_tcp(uint8_t *packet, size_t len, int syn, int ack,
 290                            int urg, int fin, int rst, int psh, int ecn,
 291                            int dport)
 292 {
 293         struct tcphdr *tcph = (struct tcphdr *) packet;
 294
 295         bug_on(len < sizeof(struct tcphdr));
 296
 297         tcph->source = htons((uint16_t) rand());
 298         tcph->dest = htons((uint16_t) dport);
 299
 300         tcph->seq = htonl(rand());
 301         tcph->ack_seq = (!!ack ? htonl(rand()) : 0);
 302
 303         tcph->doff = 5;
 304
 305         tcph->syn = !!syn;
 306         tcph->ack = !!ack;
 307         tcph->urg = !!urg;
 308         tcph->fin = !!fin;
 309         tcph->rst = !!rst;
 310         tcph->psh = !!psh;
 311         tcph->ece = !!ecn;
 312         tcph->cwr = !!ecn;
 313
 314         tcph->window = htons((uint16_t) (100 + (rand() % 65435)));
 315         tcph->urg_ptr = (!!urg ? htons((uint16_t) rand()) :  0);
 316         tcph->check = 0;
 317 }
 318
 319 static int assemble_ipv4(uint8_t *packet, size_t len, int ttl, int proto,
 320                          const struct ctx *ctx, const struct sockaddr *dst,
 321                          const struct sockaddr *src)
 322 {
 323         uint8_t *data;
 324         size_t data_len, off_next = 0;
 325         struct iphdr *iph = (struct iphdr *) packet;
 326
 327         bug_on(!src || !dst);
 328         bug_on(src->sa_family != PF_INET || dst->sa_family != PF_INET);
 329         bug_on(len < sizeof(*iph) + min(sizeof(struct tcphdr),
 330                                         sizeof(struct icmphdr)));
 331
 332         iph->ihl = 5;
 333         iph->version = 4;
 334         iph->tos = (uint8_t) ctx->tos;
 335
 336         iph->tot_len = htons((uint16_t) len);
 337         iph->id = htons((uint16_t) rand());
 338
 339         iph->frag_off = ctx->nofrag ? IP_DF : 0;
 340         iph->ttl = (uint8_t) ttl;
 341
 342         iph->saddr = ((const struct sockaddr_in *) src)->sin_addr.s_addr;
 343         iph->daddr = ((const struct sockaddr_in *) dst)->sin_addr.s_addr;
 344
 345         iph->protocol = (uint8_t) proto;
 346
 347         data = packet + sizeof(*iph);
 348         data_len = len - sizeof(*iph);
 349
 350         switch (proto) {
 351         case IPPROTO_TCP:
 352                 __assemble_tcp(data, data_len, ctx->syn, ctx->ack, ctx->urg,
 353                                ctx->fin, ctx->rst, ctx->psh, ctx->ecn, ctx->dport);
 354                 off_next = sizeof(struct tcphdr);
 355                 break;
 356         case IPPROTO_ICMP:
 357                 __assemble_icmp4(data, data_len);
 358                 off_next = sizeof(struct icmphdr);
 359                 break;
 360         default:
 361                 bug();
 362         }
 363
 364         data = packet + sizeof(*iph) + off_next;
 365         data_len = len - sizeof(*iph) - off_next;
 366
 367         __assemble_data(data, data_len, ctx->payload);
 368
 369         iph->check = csum((unsigned short *) packet, ntohs(iph->tot_len) >> 1);
 370
 371         return ntohs(iph->id);
 372 }
 373
 374 static int assemble_ipv6(uint8_t *packet, size_t len, int ttl, int proto,
 375                          const struct ctx *ctx, const struct sockaddr *dst,
 376                          const struct sockaddr *src)
 377 {
 378         uint8_t *data;
 379         size_t data_len, off_next = 0;
 380         struct ip6_hdr *ip6h = (struct ip6_hdr *) packet;
 381
 382         bug_on(!src || !dst);
 383         bug_on(src->sa_family != PF_INET6 || dst->sa_family != PF_INET6);
 384         bug_on(len < sizeof(*ip6h) + min(sizeof(struct tcphdr),
 385                                          sizeof(struct icmp6hdr)));
 386
 387         ip6h->ip6_flow = htonl(rand() & 0x000fffff);
 388         ip6h->ip6_vfc = 0x60;
 389
 390         ip6h->ip6_plen = htons((uint16_t) len - sizeof(*ip6h));
 391         ip6h->ip6_nxt = (uint8_t) proto;
 392         ip6h->ip6_hlim = (uint8_t) ttl;
 393
 394         memcpy(&ip6h->ip6_src, &(((const struct sockaddr_in6 *)
 395                src)->sin6_addr), sizeof(ip6h->ip6_src));
 396         memcpy(&ip6h->ip6_dst, &(((const struct sockaddr_in6 *)
 397                dst)->sin6_addr), sizeof(ip6h->ip6_dst));
 398
 399         data = packet + sizeof(*ip6h);
 400         data_len = len - sizeof(*ip6h);
 401
 402         switch (proto) {
 403         case IPPROTO_TCP:
 404                 __assemble_tcp(data, data_len, ctx->syn, ctx->ack, ctx->urg,
 405                                ctx->fin, ctx->rst, ctx->psh, ctx->ecn, ctx->dport);
 406                 off_next = sizeof(struct tcphdr);
 407                 break;
 408         case IPPROTO_ICMP:
 409         case IPPROTO_ICMPV6:
 410                 __assemble_icmp6(data, data_len);
 411                 off_next = sizeof(struct icmp6hdr);
 412                 break;
 413         default:
 414                 bug();
 415         }
 416
 417         data = packet + sizeof(*ip6h) + off_next;
 418         data_len = len - sizeof(*ip6h) - off_next;
 419
 420         __assemble_data(data, data_len, ctx->payload);
 421
 422         return ntohl(ip6h->ip6_flow) & 0x000fffff;
 423 }
 424
 425 static int check_ipv4(uint8_t *packet, size_t len, int ttl __maybe_unused,
 426                       int id, const struct sockaddr *ss)
 427 {
 428         struct iphdr *iph = (struct iphdr *) packet;
 429         struct iphdr *iph_inner;
 430         struct icmphdr *icmph;
 431
 432         if (iph->protocol != IPPROTO_ICMP)
 433                 return -EINVAL;
 434         if (iph->daddr != ((const struct sockaddr_in *) ss)->sin_addr.s_addr)
 435                 return -EINVAL;
 436
 437         icmph = (struct icmphdr *) (packet + sizeof(struct iphdr));
 438         if (icmph->type != ICMP_TIME_EXCEEDED)
 439                 return -EINVAL;
 440         if (icmph->code != ICMP_EXC_TTL)
 441                 return -EINVAL;
 442
 443         iph_inner = (struct iphdr *) (packet + sizeof(struct iphdr) +
 444                                       sizeof(struct icmphdr));
 445         if (ntohs(iph_inner->id) != id)
 446                 return -EINVAL;
 447
 448         return len;
 449 }
 450
 451 static void handle_ipv4(uint8_t *packet, size_t len __maybe_unused,
 452                         int dns_resolv, int latitude)
 453 {
 454         char hbuff[NI_MAXHOST];
 455         struct iphdr *iph = (struct iphdr *) packet;
 456         struct sockaddr_in sd;
 457         struct hostent *hent;
 458         const char *as, *country, *city;
 459
 460         memset(hbuff, 0, sizeof(hbuff));
 461         memset(&sd, 0, sizeof(sd));
 462         sd.sin_family = PF_INET;
 463         sd.sin_addr.s_addr = iph->saddr;
 464
 465         getnameinfo((struct sockaddr *) &sd, sizeof(sd),
 466                     hbuff, sizeof(hbuff), NULL, 0, NI_NUMERICHOST);
 467
 468         as = geoip4_as_name(&sd);
 469         country = geoip4_country_name(&sd);
 470         city = geoip4_city_name(&sd);
 471
 472         if (dns_resolv) {
 473                 hent = gethostbyaddr(&sd.sin_addr, sizeof(sd.sin_addr), PF_INET);
 474                 if (hent)
 475                         printf(" %s (%s)", hent->h_name, hbuff);
 476                 else
 477                         printf(" %s", hbuff);
 478         } else {
 479                 printf(" %s", hbuff);
 480         }
 481         if (as)
 482                 printf(" in %s", as);
 483         if (country) {
 484                 printf(" in %s", country);
 485                 if (city)
 486                         printf(", %s", city);
 487         }
 488         if (latitude)
 489                 printf(" (%f/%f)", geoip4_latitude(&sd), geoip4_longitude(&sd));
 490 }
 491
 492 static int check_ipv6(uint8_t *packet, size_t len, int ttl __maybe_unused,
 493                       int id, const struct sockaddr *ss)
 494 {
 495         struct ip6_hdr *ip6h = (struct ip6_hdr *) packet;
 496         struct ip6_hdr *ip6h_inner;
 497         struct icmp6hdr *icmp6h;
 498
 499         if (ip6h->ip6_nxt != 0x3a)
 500                 return -EINVAL;
 501         if (memcmp(&ip6h->ip6_dst, &(((const struct sockaddr_in6 *)
 502                    ss)->sin6_addr), sizeof(ip6h->ip6_dst)))
 503                 return -EINVAL;
 504
 505         icmp6h = (struct icmp6hdr *) (packet + sizeof(*ip6h));
 506         if (icmp6h->icmp6_type != ICMPV6_TIME_EXCEED)
 507                 return -EINVAL;
 508         if (icmp6h->icmp6_code != ICMPV6_EXC_HOPLIMIT)
 509                 return -EINVAL;
 510
 511         ip6h_inner = (struct ip6_hdr *) (packet + sizeof(*ip6h) + sizeof(*icmp6h));
 512         if ((ntohl(ip6h_inner->ip6_flow) & 0x000fffff) != (uint32_t) id)
 513                 return -EINVAL;
 514
 515         return len;
 516 }
 517
 518 static void handle_ipv6(uint8_t *packet, size_t len __maybe_unused,
 519                         int dns_resolv, int latitude)
 520 {
 521         char hbuff[NI_MAXHOST];
 522         struct ip6_hdr *ip6h = (struct ip6_hdr *) packet;
 523         struct sockaddr_in6 sd;
 524         struct hostent *hent;
 525         const char *as, *country, *city;
 526
 527         memset(hbuff, 0, sizeof(hbuff));
 528         memset(&sd, 0, sizeof(sd));
 529         sd.sin6_family = PF_INET6;
 530         memcpy(&sd.sin6_addr, &ip6h->ip6_src, sizeof(ip6h->ip6_src));
 531
 532         getnameinfo((struct sockaddr *) &sd, sizeof(sd),
 533                     hbuff, sizeof(hbuff), NULL, 0, NI_NUMERICHOST);
 534
 535         as = geoip6_as_name(&sd);
 536         country = geoip6_country_name(&sd);
 537         city = geoip6_city_name(&sd);
 538
 539         if (dns_resolv) {
 540                 hent = gethostbyaddr(&sd.sin6_addr, sizeof(sd.sin6_addr), PF_INET6);
 541                 if (hent)
 542                         printf(" %s (%s)", hent->h_name, hbuff);
 543                 else
 544                         printf(" %s", hbuff);
 545         } else {
 546                 printf(" %s", hbuff);
 547         }
 548         if (as)
 549                 printf(" in %s", as);
 550         if (country) {
 551                 printf(" in %s", country);
 552                 if (city)
 553                         printf(", %s", city);
 554         }
 555         if (latitude)
 556                 printf(" (%f/%f)", geoip6_latitude(&sd), geoip6_longitude(&sd));
 557 }
 558
 559 static void show_trace_info(struct ctx *ctx, const struct sockaddr_storage *ss,
 560                             const struct sockaddr_storage *sd)
 561 {
 562         char hbuffs[256], hbuffd[256];
 563
 564         memset(hbuffd, 0, sizeof(hbuffd));
 565         getnameinfo((struct sockaddr *) sd, sizeof(*sd),
 566                     hbuffd, sizeof(hbuffd), NULL, 0, NI_NUMERICHOST);
 567
 568         memset(hbuffs, 0, sizeof(hbuffs));
 569         getnameinfo((struct sockaddr *) ss, sizeof(*ss),
 570                     hbuffs, sizeof(hbuffs), NULL, 0, NI_NUMERICHOST);
 571
 572         printf("AS path IPv%d TCP trace from %s to %s:%s (%s) with len %zu "
 573                "Bytes, %u max hops\n", ctx->proto == IPPROTO_IP ? 4 : 6,
 574                hbuffs, hbuffd, ctx->port, ctx->host, ctx->totlen, ctx->max_ttl);
 575
 576         printf("Using flags SYN:%d,ACK:%d,ECN:%d,FIN:%d,PSH:%d,RST:%d,URG:%d\n",
 577                ctx->syn, ctx->ack, ctx->ecn, ctx->fin, ctx->psh, ctx->rst, ctx->urg);
 578
 579         if (ctx->payload)
 580                 printf("With payload: \'%s\'\n", ctx->payload);
 581 }
 582
 583 static int get_remote_fd(struct ctx *ctx, struct sockaddr_storage *ss,
 584                          struct sockaddr_storage *sd)
 585 {
 586         int fd = -1, ret, one = 1, af = AF_INET;
 587         struct addrinfo hints, *ahead, *ai;
 588         unsigned char bind_ip[sizeof(struct in6_addr)];
 589
 590         memset(&hints, 0, sizeof(hints));
 591         hints.ai_family = PF_UNSPEC;
 592         hints.ai_socktype = SOCK_STREAM;
 593         hints.ai_protocol = IPPROTO_TCP;
 594         hints.ai_flags = AI_NUMERICSERV;
 595
 596         ret = getaddrinfo(ctx->host, ctx->port, &hints, &ahead);
 597         if (ret < 0)
 598                 panic("Cannot get address info!\n");
 599
 600         for (ai = ahead; ai != NULL && fd < 0; ai = ai->ai_next) {
 601                 if (!((ai->ai_family == PF_INET6 && ctx->proto == IPPROTO_IPV6) ||
 602                       (ai->ai_family == PF_INET  && ctx->proto == IPPROTO_IP)))
 603                         continue;
 604
 605                 fd = socket(ai->ai_family, SOCK_RAW, IPPROTO_RAW);
 606                 if (fd < 0)
 607                         continue;
 608
 609                 memset(ss, 0, sizeof(*ss));
 610                 ret = device_address(ctx->dev, ai->ai_family, ss);
 611                 if (ret < 0 && !ctx->bind_addr)
 612                         panic("Cannot get own device address!\n");
 613
 614                 if (ctx->bind_addr) {
 615                         if (ctx->proto == IPPROTO_IPV6)
 616                                 af = AF_INET6;
 617
 618                         if (inet_pton(af, ctx->bind_addr, &bind_ip) != 1)
 619                                 panic("Address is invalid!\n");
 620
 621                         if (af == AF_INET6) {
 622                                 struct sockaddr_in6 *ss6 = (struct sockaddr_in6 *) ss;
 623                                 memcpy(&ss6->sin6_addr.s6_addr, &bind_ip, sizeof(struct in6_addr));
 624                         } else {
 625                                 struct sockaddr_in *ss4 = (struct sockaddr_in *) ss;
 626                                 memcpy(&ss4->sin_addr.s_addr, &bind_ip, sizeof(struct in_addr));
 627                         }
 628                 }
 629
 630                 ret = bind(fd, (struct sockaddr *) ss, sizeof(*ss));
 631                 if (ret < 0)
 632                         panic("Cannot bind socket!\n");
 633
 634                 memset(sd, 0, sizeof(*sd));
 635                 memcpy(sd, ai->ai_addr, ai->ai_addrlen);
 636
 637                 ctx->sd_len = ai->ai_addrlen;
 638                 ctx->dport = strtoul(ctx->port, NULL, 10);
 639
 640                 ret = setsockopt(fd, ctx->proto, IP_HDRINCL, &one, sizeof(one));
 641                 if (ret < 0)
 642                         panic("Kernel does not support IP_HDRINCL!\n");
 643
 644                 if (ai->ai_family == PF_INET6) {
 645                         struct sockaddr_in6 *sd6 = (struct sockaddr_in6 *) sd;
 646
 647                         sd6->sin6_port = 0;
 648                 }
 649
 650                 break;
 651         }
 652
 653         freeaddrinfo(ahead);
 654
 655         if (fd < 0)
 656                 panic("Cannot create socket! Does remote "
 657                       "support IPv%d?!\n",
 658                       ctx->proto == IPPROTO_IP ? 4 : 6);
 659
 660         return fd;
 661 }
 662
 663 static void inject_filter(struct ctx *ctx, int fd)
 664 {
 665         struct sock_fprog bpf_ops;
 666
 667         enable_kernel_bpf_jit_compiler();
 668
 669         memset(&bpf_ops, 0, sizeof(bpf_ops));
 670         bpf_ops.filter = (struct sock_filter *) af_ops[ctx->proto].filter;
 671         bpf_ops.len = af_ops[ctx->proto].flen;
 672
 673         bpf_attach_to_sock(fd, &bpf_ops);
 674 }
 675
 676 static int __process_node(struct ctx *ctx, int fd, int fd_cap, int ttl,
 677                           int inner_proto, uint8_t *pkt_snd, uint8_t *pkt_rcv,
 678                           const struct sockaddr_storage *ss,
 679                           const struct sockaddr_storage *sd, struct timeval *diff)
 680 {
 681         int pkt_id, ret, timeout;
 682         struct pollfd pfd;
 683         struct timeval start, end;
 684
 685         prepare_polling(fd_cap, &pfd);
 686
 687         memset(pkt_snd, 0, ctx->totlen);
 688         pkt_id = af_ops[ctx->proto].assembler(pkt_snd, ctx->totlen, ttl,
 689                                               inner_proto, ctx,
 690                                               (const struct sockaddr *) sd,
 691                                               (const struct sockaddr *) ss);
 692
 693         ret = sendto(fd, pkt_snd, ctx->totlen, 0, (struct sockaddr *) sd,
 694                      ctx->sd_len);
 695         if (ret < 0)
 696                 panic("sendto failed: %s\n", strerror(errno));
 697
 698         bug_on(gettimeofday(&start, NULL));
 699
 700         timeout = (ctx->timeout > 0 ? ctx->timeout : 2) * 1000;
 701
 702         ret = poll(&pfd, 1, timeout);
 703         if (ret > 0 && pfd.revents & POLLIN && sigint == 0) {
 704                 bug_on(gettimeofday(&end, NULL));
 705                 if (diff)
 706                         timersub(&end, &start, diff);
 707
 708                 ret = recvfrom(fd_cap, pkt_rcv, ctx->rcvlen, 0, NULL, NULL);
 709                 if (ret < (int) (sizeof(struct ethhdr) + af_ops[ctx->proto].min_len_icmp))
 710                         return -EIO;
 711
 712                 return af_ops[ctx->proto].check(pkt_rcv + sizeof(struct ethhdr),
 713                                                 ret - sizeof(struct ethhdr), ttl,
 714                                                 pkt_id, (const struct sockaddr *) ss);
 715         } else {
 716                 return -EIO;
 717         }
 718
 719         return 0;
 720 }
 721
 722 static void timerdiv(const unsigned long divisor, const struct timeval *tv,
 723                      struct timeval *result)
 724 {
 725         uint64_t x = ((uint64_t) tv->tv_sec * 1000 * 1000 + tv->tv_usec) / divisor;
 726
 727         result->tv_sec = x / 1000 / 1000;
 728         result->tv_usec = x % (1000 * 1000);
 729 }
 730
 731 static int timevalcmp(const void *t1, const void *t2)
 732 {
 733         if (timercmp((struct timeval *) t1, (struct timeval *) t2, <))
 734                 return -1;
 735         if (timercmp((struct timeval *) t1, (struct timeval *) t2, >))
 736                 return  1;
 737
 738         return 0;
 739 }
 740
 741 static int __process_time(struct ctx *ctx, int fd, int fd_cap, int ttl,
 742                           int inner_proto, uint8_t *pkt_snd, uint8_t *pkt_rcv,
 743                           const struct sockaddr_storage *ss,
 744                           const struct sockaddr_storage *sd)
 745 {
 746         size_t i, j = 0;
 747         int good = 0, ret = -EIO, idx, ret_good = -EIO;
 748         struct timeval probes[9], *tmp, sum, res;
 749         uint8_t *trash = xmalloc(ctx->rcvlen);
 750         char *cwait[] = { "-", "\\", "|", "/" };
 751         const char *proto_short[] = {
 752                 [IPPROTO_TCP]           =       "t",
 753                 [IPPROTO_ICMP]          =       "i",
 754                 [IPPROTO_ICMPV6]        =       "i",
 755         };
 756
 757         memset(probes, 0, sizeof(probes));
 758         for (i = 0; i < array_size(probes) && sigint == 0; ++i) {
 759                 ret = __process_node(ctx, fd, fd_cap, ttl, inner_proto,
 760                                      pkt_snd, good == 0 ? pkt_rcv : trash,
 761                                      ss, sd, &probes[i]);
 762                 if (ret > 0) {
 763                         if (good == 0)
 764                                 ret_good = ret;
 765                         good++;
 766                 }
 767
 768                 if (good == 0 && ctx->queries == (int) i)
 769                         break;
 770
 771                 usleep(50000);
 772
 773                 printf("\r%2d: %s", ttl, cwait[j++]);
 774                 fflush(stdout);
 775                 if (j >= array_size(cwait))
 776                         j = 0;
 777         }
 778
 779         if (good == 0) {
 780                 xfree(trash);
 781                 return -EIO;
 782         }
 783
 784         tmp = xcalloc(good, sizeof(struct timeval));
 785         for (i = j = 0; i < array_size(probes); ++i) {
 786                 if (probes[i].tv_sec == 0 && probes[i].tv_usec == 0)
 787                         continue;
 788                 tmp[j].tv_sec = probes[i].tv_sec;
 789                 tmp[j].tv_usec = probes[i].tv_usec;
 790                 j++;
 791         }
 792
 793         qsort(tmp, j, sizeof(struct timeval), timevalcmp);
 794
 795         printf("\r%2d: %s[", ttl, proto_short[inner_proto]);
 796         idx = j / 2;
 797         switch (j % 2) {
 798         case 0:
 799                 timeradd(&tmp[idx], &tmp[idx - 1], &sum);
 800                 timerdiv(2, &sum, &res);
 801                 if (res.tv_sec > 0)
 802                         printf("%lu sec ", res.tv_sec);
 803                 printf("%7lu us", res.tv_usec);
 804                 break;
 805         case 1:
 806                 if (tmp[idx].tv_sec > 0)
 807                         printf("%lu sec ", tmp[idx].tv_sec);
 808                 printf("%7lu us", tmp[idx].tv_usec);
 809                 break;
 810         }
 811         printf("]");
 812
 813         xfree(tmp);
 814         xfree(trash);
 815
 816         return ret_good;
 817 }
 818
 819 static int __probe_remote(struct ctx *ctx, int fd, int fd_cap, int ttl,
 820                           uint8_t *pkt_snd, uint8_t *pkt_rcv,
 821                           const struct sockaddr_storage *ss,
 822                           const struct sockaddr_storage *sd,
 823                           int inner_proto)
 824 {
 825         int ret = -EIO, tries = ctx->queries;
 826
 827         while (tries-- > 0 && sigint == 0) {
 828                 ret = __process_time(ctx, fd, fd_cap, ttl, inner_proto,
 829                                      pkt_snd, pkt_rcv, ss, sd);
 830                 if (ret < 0)
 831                         continue;
 832
 833                 af_ops[ctx->proto].handler(pkt_rcv + sizeof(struct ethhdr),
 834                                            ret - sizeof(struct ethhdr),
 835                                            ctx->dns_resolv, ctx->latitude);
 836                 if (ctx->show) {
 837                         struct pkt_buff *pkt;
 838
 839                         printf("\n");
 840                         pkt = pkt_alloc(pkt_rcv, ret);
 841                         hex_ascii(pkt);
 842                         tprintf_flush();
 843                         pkt_free(pkt);
 844                 }
 845
 846                 break;
 847         }
 848
 849         return ret;
 850 }
 851
 852 static int __process_ttl(struct ctx *ctx, int fd, int fd_cap, int ttl,
 853                          uint8_t *pkt_snd, uint8_t *pkt_rcv,
 854                          const struct sockaddr_storage *ss,
 855                          const struct sockaddr_storage *sd)
 856 {
 857         int ret = -EIO;
 858         size_t i;
 859         const int inner_protos[] = {
 860                 IPPROTO_TCP,
 861                 IPPROTO_ICMP,
 862         };
 863
 864         printf("%2d: ", ttl);
 865         fflush(stdout);
 866
 867         for (i = 0; i < array_size(inner_protos) && sigint == 0; ++i) {
 868                 ret = __probe_remote(ctx, fd, fd_cap, ttl, pkt_snd, pkt_rcv, ss, sd,
 869                                      inner_protos[i]);
 870                 if (ret > 0)
 871                         break;
 872         }
 873
 874         if (ret <= 0)
 875                 printf("\r%2d: ?[ no answer]", ttl);
 876         if (ctx->show == 0)
 877                 printf("\n");
 878         if (ctx->show && ret <= 0)
 879                 printf("\n\n");
 880
 881         fflush(stdout);
 882         return 0;
 883 }
 884
 885 static int main_trace(struct ctx *ctx)
 886 {
 887         int fd, fd_cap, ifindex, ttl;
 888         struct ring dummy_ring;
 889         struct sockaddr_storage ss, sd;
 890         uint8_t *pkt_snd, *pkt_rcv;
 891
 892         fd = get_remote_fd(ctx, &ss, &sd);
 893         fd_cap = pf_socket();
 894
 895         inject_filter(ctx, fd_cap);
 896
 897         ifindex = device_ifindex(ctx->dev);
 898         bind_ring_generic(fd_cap, &dummy_ring, ifindex, false);
 899
 900         if (ctx->totlen < af_ops[ctx->proto].min_len_tcp) {
 901                 ctx->totlen = af_ops[ctx->proto].min_len_tcp;
 902                 if (ctx->payload)
 903                         ctx->totlen += strlen(ctx->payload);
 904         }
 905
 906         ctx->rcvlen = device_mtu(ctx->dev) - sizeof(struct ethhdr);
 907         if (ctx->totlen >= ctx->rcvlen)
 908                 panic("Packet len exceeds device MTU!\n");
 909
 910         pkt_snd = xmalloc(ctx->totlen);
 911         pkt_rcv = xmalloc(ctx->rcvlen);
 912
 913         show_trace_info(ctx, &ss, &sd);
 914
 915         for (ttl = ctx->init_ttl; ttl <= ctx->max_ttl && sigint == 0; ++ttl)
 916                 __process_ttl(ctx, fd, fd_cap, ttl, pkt_snd, pkt_rcv,
 917                               &ss, &sd);
 918
 919         xfree(pkt_snd);
 920         xfree(pkt_rcv);
 921
 922         close(fd_cap);
 923         close(fd);
 924
 925         return 0;
 926 }
 927
 928 int main(int argc, char **argv)
 929 {
 930         int c, opt_index, ret;
 931         struct ctx ctx;
 932
 933         setfsuid(getuid());
 934         setfsgid(getgid());
 935
 936         srand(time(NULL));
 937
 938         memset(&ctx, 0, sizeof(ctx));
 939         ctx.init_ttl = 1;
 940         ctx.max_ttl = 30;
 941         ctx.queries = 2;
 942         ctx.timeout = 2;
 943         ctx.proto = IPPROTO_IP;
 944         ctx.payload = NULL;
 945         ctx.dev = xstrdup("eth0");
 946         ctx.port = xstrdup("80");
 947         ctx.bind_addr = NULL;
 948
 949         while ((c = getopt_long(argc, argv, short_options, long_options,
 950                 &opt_index)) != EOF) {
 951                 switch (c) {
 952                 case 'h':
 953                         help();
 954                         break;
 955                 case 'v':
 956                         version();
 957                         break;
 958                 case 'u':
 959                         update_geoip();
 960                         die();
 961                         break;
 962                 case 'H':
 963                         ctx.host = xstrdup(optarg);
 964                         break;
 965                 case 'p':
 966                         if (ctx.port)
 967                                 xfree(ctx.port);
 968                         ctx.port = xstrdup(optarg);
 969                         break;
 970                 case 'n':
 971                         ctx.dns_resolv = 0;
 972                         break;
 973                 case '4':
 974                         ctx.proto = IPPROTO_IP;
 975                         break;
 976                 case '6':
 977                         ctx.proto = IPPROTO_IPV6;
 978                         break;
 979                 case 'Z':
 980                         ctx.show = 1;
 981                         break;
 982                 case 'N':
 983                         ctx.dns_resolv = 1;
 984                         break;
 985                 case 'f':
 986                         ctx.init_ttl = atoi(optarg);
 987                         if (ctx.init_ttl <= 0)
 988                                 help();
 989                         break;
 990                 case 'm':
 991                         ctx.max_ttl = atoi(optarg);
 992                         if (ctx.max_ttl <= 0)
 993                                 help();
 994                         break;
 995                 case 'b':
 996                         ctx.bind_addr = xstrdup(optarg);
 997                         break;
 998                 case 'i':
 999                 case 'd':
1000                         free(ctx.dev);
1001                         ctx.dev = xstrdup(optarg);
1002                         break;
1003                 case 'q':
1004                         ctx.queries = atoi(optarg);
1005                         if (ctx.queries <= 0)
1006                                 help();
1007                         break;
1008                 case 'x':
1009                         ctx.timeout = atoi(optarg);
1010                         if (ctx.timeout <= 0)
1011                                 help();
1012                         break;
1013                 case 'L':
1014                         ctx.latitude = 1;
1015                         break;
1016                 case 'S':
1017                         ctx.syn = 1;
1018                         break;
1019                 case 'A':
1020                         ctx.ack = 1;
1021                         break;
1022                 case 'F':
1023                         ctx.fin = 1;
1024                         break;
1025                 case 'U':
1026                         ctx.urg = 1;
1027                         break;
1028                 case 'P':
1029                         ctx.psh = 1;
1030                         break;
1031                 case 'R':
1032                         ctx.rst = 1;
1033                         break;
1034                 case 'E':
1035                         ctx.syn = 1;
1036                         ctx.ecn = 1;
1037                         break;
1038                 case 't':
1039                         ctx.tos = atoi(optarg);
1040                         if (ctx.tos < 0)
1041                                 help();
1042                         break;
1043                 case 'G':
1044                         ctx.nofrag = 1;
1045                         break;
1046                 case 'X':
1047                         ctx.payload = xstrdup(optarg);
1048                         break;
1049                 case 'l':
1050                         ctx.totlen = strtoul(optarg, NULL, 10);
1051                         if (ctx.totlen == 0)
1052                                 help();
1053                         break;
1054                 case '?':
1055                         switch (optopt) {
1056                         case 'H':
1057                         case 'p':
1058                         case 'f':
1059                         case 'm':
1060                         case 'i':
1061                         case 'd':
1062                         case 'q':
1063                         case 'x':
1064                         case 'X':
1065                         case 't':
1066                         case 'l':
1067                                 panic("Option -%c requires an argument!\n",
1068                                       optopt);
1069                         default:
1070                                 if (isprint(optopt))
1071                                         printf("Unknown option character `0x%X\'!\n", optopt);
1072                                 die();
1073                 }
1074                 default:
1075                         break;
1076                 }
1077         }
1078
1079         if (argc < 3 || !ctx.host || !ctx.port || ctx.init_ttl > ctx.max_ttl ||
1080             ctx.init_ttl > MAXTTL || ctx.max_ttl > MAXTTL)
1081                 help();
1082
1083         if (!device_up_and_running(ctx.dev))
1084                 panic("Networking device not up and running!\n");
1085         if (device_mtu(ctx.dev) <= ctx.totlen)
1086                 panic("Packet larger than device MTU!\n");
1087
1088         register_signal(SIGHUP, signal_handler);
1089         register_signal(SIGINT, signal_handler);
1090         register_signal(SIGQUIT, signal_handler);
1091         register_signal(SIGTERM, signal_handler);
1092
1093         tprintf_init();
1094         init_geoip(1);
1095
1096         ret = main_trace(&ctx);
1097
1098         destroy_geoip();
1099         tprintf_cleanup();
1100
1101         free(ctx.dev);
1102         free(ctx.host);
1103         free(ctx.port);
1104         free(ctx.bind_addr);
1105         free(ctx.payload);
1106
1107         return ret;
1108 }