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 #define _DEFAULT_SOURCE
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <signal.h>
  12 #include <getopt.h>
  13 #include <ctype.h>
  14 #include <stdint.h>
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <sys/socket.h>
  18 #include <sys/fsuid.h>
  19 #include <fcntl.h>
  20 #include <time.h>
  21 #include <string.h>
  22 #include <asm/byteorder.h>
  23 #include <linux/tcp.h>
  24 #include <netinet/ip.h>
  25 #include <netinet/ip6.h>
  26 #include <netinet/in.h>
  27 #include <errno.h>
  28 #include <netdb.h>
  29 #include <sys/time.h>
  30 #include <arpa/inet.h>
  31 #include <linux/if_ether.h>
  32 #include <linux/icmp.h>
  33 #include <linux/icmpv6.h>
  34
  35 #include "bpf.h"
  36 #include "die.h"
  37 #include "dev.h"
  38 #include "sig.h"
  39 #include "config.h"
  40 #include "tprintf.h"
  41 #include "pkt_buff.h"
  42 #include "proto.h"
  43 #include "xmalloc.h"
  44 #include "csum.h"
  45 #include "sock.h"
  46 #include "geoip.h"
  47 #include "ring.h"
  48 #include "built_in.h"
  49
  50 struct ctx {
  51         char *host, *port, *dev, *payload, *bind_addr;
  52         size_t totlen, rcvlen;
  53         socklen_t sd_len;
  54         int init_ttl, max_ttl, dns_resolv, queries, timeout;
  55         int syn, ack, ecn, fin, psh, rst, urg, tos, nofrag, proto, show;
  56         int dport, latitude;
  57 };
  58
  59 struct proto_ops {
  60         int (*assembler)(uint8_t *packet, size_t len, int ttl, int proto,
  61                          const struct ctx *ctx, const struct sockaddr *dst,
  62                          const struct sockaddr *src);
  63         const struct sock_filter *filter;
  64         unsigned int flen;
  65         size_t min_len_tcp, min_len_icmp;
  66         int (*check)(uint8_t *packet, size_t len, int ttl, int id,
  67                      const struct sockaddr *src);
  68         void (*handler)(uint8_t *packet, size_t len, int dns_resolv,
  69                         int latitude);
  70 };
  71
  72 static sig_atomic_t sigint = 0;
  73
  74 static int assemble_ipv4(uint8_t *packet, size_t len, int ttl, int proto,
  75                          const struct ctx *ctx, const struct sockaddr *dst,
  76                          const struct sockaddr *src);
  77 static int assemble_ipv6(uint8_t *packet, size_t len, int ttl, int proto,
  78                          const struct ctx *ctx, const struct sockaddr *dst,
  79                          const struct sockaddr *src);
  80 static int check_ipv4(uint8_t *packet, size_t len, int ttl, int id,
  81                       const struct sockaddr *ss);
  82 static void handle_ipv4(uint8_t *packet, size_t len, int dns_resolv,
  83                         int latitude);
  84 static int check_ipv6(uint8_t *packet, size_t len, int ttl, int id,
  85                       const struct sockaddr *ss);
  86 static void handle_ipv6(uint8_t *packet, size_t len, int dns_resolv,
  87                         int latitude);
  88
  89 static const char *short_options = "H:p:nNf:m:b:i:d:q:x:SAEFPURt:Gl:hv46X:ZuL";
  90 static const struct option long_options[] = {
  91         {"host",        required_argument,      NULL, 'H'},
  92         {"port",        required_argument,      NULL, 'p'},
  93         {"init-ttl",    required_argument,      NULL, 'f'},
  94         {"max-ttl",     required_argument,      NULL, 'm'},
  95         {"bind",        required_argument,      NULL, 'b'},
  96         {"dev",         required_argument,      NULL, 'd'},
  97         {"num-probes",  required_argument,      NULL, 'q'},
  98         {"timeout",     required_argument,      NULL, 'x'},
  99         {"tos",         required_argument,      NULL, 't'},
 100         {"payload",     required_argument,      NULL, 'X'},
 101         {"totlen",      required_argument,      NULL, 'l'},
 102         {"numeric",     no_argument,            NULL, 'n'},
 103         {"latitude",    no_argument,            NULL, 'L'},
 104         {"update",      no_argument,            NULL, 'u'},
 105         {"dns",         no_argument,            NULL, 'N'},
 106         {"ipv4",        no_argument,            NULL, '4'},
 107         {"ipv6",        no_argument,            NULL, '6'},
 108         {"syn",         no_argument,            NULL, 'S'},
 109         {"ack",         no_argument,            NULL, 'A'},
 110         {"urg",         no_argument,            NULL, 'U'},
 111         {"fin",         no_argument,            NULL, 'F'},
 112         {"psh",         no_argument,            NULL, 'P'},
 113         {"rst",         no_argument,            NULL, 'R'},
 114         {"ecn-syn",     no_argument,            NULL, 'E'},
 115         {"show-packet", no_argument,            NULL, 'Z'},
 116         {"nofrag",      no_argument,            NULL, 'G'},
 117         {"version",     no_argument,            NULL, 'v'},
 118         {"help",        no_argument,            NULL, 'h'},
 119         {NULL, 0, NULL, 0}
 120 };
 121
 122 static const char *copyright = "Please report bugs to <netsniff-ng@googlegroups.com>\n"
 123         "Copyright (C) 2011-2013 Daniel Borkmann <dborkma@tik.ee.ethz.ch>\n"
 124         "Swiss federal institute of technology (ETH Zurich)\n"
 125         "License: GNU GPL version 2.0\n"
 126         "This is free software: you are free to change and redistribute it.\n"
 127         "There is NO WARRANTY, to the extent permitted by law.";
 128
 129 static const struct sock_filter ipv4_icmp_type_11[] = {
 130         { 0x28, 0, 0, 0x0000000c },     /* ldh [12]             */
 131         { 0x15, 0, 8, 0x00000800 },     /* jneq #0x800, drop    */
 132         { 0x30, 0, 0, 0x00000017 },     /* ldb [23]             */
 133         { 0x15, 0, 6, 0x00000001 },     /* jneq #0x1, drop      */
 134         { 0x28, 0, 0, 0x00000014 },     /* ldh [20]             */
 135         { 0x45, 4, 0, 0x00001fff },     /* jset #0x1fff, drop   */
 136         { 0xb1, 0, 0, 0x0000000e },     /* ldxb 4*([14]&0xf)    */
 137         { 0x50, 0, 0, 0x0000000e },     /* ldb [x + 14]         */
 138         { 0x15, 0, 1, 0x0000000b },     /* jneq #0xb, drop      */
 139         { 0x06, 0, 0, 0xffffffff },     /* ret #-1              */
 140         { 0x06, 0, 0, 0x00000000 },     /* drop: ret #0         */
 141 };
 142
 143 static const struct sock_filter ipv6_icmp6_type_3[] = {
 144         { 0x28, 0, 0, 0x0000000c },     /* ldh [12]             */
 145         { 0x15, 0, 5, 0x000086dd },     /* jneq #0x86dd, drop   */
 146         { 0x30, 0, 0, 0x00000014 },     /* ldb [20]             */
 147         { 0x15, 0, 3, 0x0000003a },     /* jneq #0x3a, drop     */
 148         { 0x30, 0, 0, 0x00000036 },     /* ldb [54]             */
 149         { 0x15, 0, 1, 0x00000003 },     /* jneq #0x3, drop      */
 150         { 0x06, 0, 0, 0xffffffff },     /* ret #-1              */
 151         { 0x06, 0, 0, 0x00000000 },     /* drop: ret #0         */
 152 };
 153
 154 static const struct proto_ops af_ops[] = {
 155         [IPPROTO_IP]    =       {
 156                         .assembler      =       assemble_ipv4,
 157                         .handler        =       handle_ipv4,
 158                         .check          =       check_ipv4,
 159                         .filter         =       ipv4_icmp_type_11,
 160                         .flen           =       array_size(ipv4_icmp_type_11),
 161                         .min_len_tcp    =       sizeof(struct iphdr) + sizeof(struct tcphdr),
 162                         .min_len_icmp   =       sizeof(struct iphdr) + sizeof(struct icmphdr),
 163                 },
 164         [IPPROTO_IPV6]  =       {
 165                         .assembler      =       assemble_ipv6,
 166                         .handler        =       handle_ipv6,
 167                         .check          =       check_ipv6,
 168                         .filter         =       ipv6_icmp6_type_3,
 169                         .flen           =       array_size(ipv6_icmp6_type_3),
 170                         .min_len_tcp    =       sizeof(struct ip6_hdr) + sizeof(struct tcphdr),
 171                         .min_len_icmp   =       sizeof(struct ip6_hdr) + sizeof(struct icmp6hdr),
 172                 },
 173 };
 174
 175 static void signal_handler(int number)
 176 {
 177         switch (number) {
 178         case SIGINT:
 179         case SIGQUIT:
 180         case SIGTERM:
 181                 sigint = 1;
 182         default:
 183                 break;
 184         }
 185 }
 186
 187 static void __noreturn help(void)
 188 {
 189         printf("astraceroute %s, autonomous system trace route utility\n", VERSION_STRING);
 190         puts("http://www.netsniff-ng.org\n\n"
 191              "Usage: astraceroute [options]\n"
 192              "Options:\n"
 193              " -H|--host <host>        Host/IPv4/IPv6 to lookup AS route to\n"
 194              " -p|--port <port>        Hosts port to lookup AS route to\n"
 195              " -i|-d|--dev <device>    Networking device, e.g. eth0\n"
 196              " -b|--bind <IP>          IP address to bind to, Must specify -6 for an IPv6 address\n"
 197              " -f|--init-ttl <ttl>     Set initial TTL\n"
 198              " -m|--max-ttl <ttl>      Set maximum TTL (def: 30)\n"
 199              " -q|--num-probes <num>   Number of max probes for each hop (def: 2)\n"
 200              " -x|--timeout <sec>      Probe response timeout in sec (def: 3)\n"
 201              " -X|--payload <string>   Specify a payload string to test DPIs\n"
 202              " -l|--totlen <len>       Specify total packet len\n"
 203              " -4|--ipv4               Use IPv4-only requests\n"
 204              " -6|--ipv6               Use IPv6-only requests\n"
 205              " -n|--numeric            Do not do reverse DNS lookup for hops\n"
 206              " -u|--update             Update GeoIP databases\n"
 207              " -L|--latitude           Show latitude and longitude\n"
 208              " -N|--dns                Do a reverse DNS lookup for hops\n"
 209              " -S|--syn                Set TCP SYN flag\n"
 210              " -A|--ack                Set TCP ACK flag\n"
 211              " -F|--fin                Set TCP FIN flag\n"
 212              " -P|--psh                Set TCP PSH flag\n"
 213              " -U|--urg                Set TCP URG flag\n"
 214              " -R|--rst                Set TCP RST flag\n"
 215              " -E|--ecn-syn            Send ECN SYN packets (RFC3168)\n"
 216              " -t|--tos <tos>          Set the IP TOS field\n"
 217              " -G|--nofrag             Set do not fragment bit\n"
 218              " -Z|--show-packet        Show returned packet on each hop\n"
 219              " -v|--version            Print version and exit\n"
 220              " -h|--help               Print this help and exit\n\n"
 221              "Examples:\n"
 222              "  IPv4 trace of AS with TCP SYN probe (this will most-likely pass):\n"
 223              "    astraceroute -i eth0 -N -S -H netsniff-ng.org\n"
 224              "  IPv4 trace of AS with TCP ECN SYN probe:\n"
 225              "    astraceroute -i eth0 -N -E -H netsniff-ng.org\n"
 226              "  IPv4 trace of AS with TCP FIN probe:\n"
 227              "    astraceroute -i eth0 -N -F -H netsniff-ng.org\n"
 228              "  IPv4 trace of AS with Xmas probe:\n"
 229              "    astraceroute -i eth0 -N -FPU -H netsniff-ng.org\n"
 230              "  IPv4 trace of AS with Null probe with ASCII payload:\n"
 231              "    astraceroute -i eth0 -N -H netsniff-ng.org -X \"censor-me\" -Z\n"
 232              "  IPv6 trace of AS up to www.6bone.net:\n"
 233              "    astraceroute -6 -i eth0 -S -E -N -H www.6bone.net\n\n"
 234              "Note:\n"
 235              "  If the TCP probe did not give any results, then astraceroute will\n"
 236              "  automatically probe for classic ICMP packets! To gather more\n"
 237              "  information about astraceroute's fetched AS numbers, see e.g.\n"
 238              "  http://bgp.he.net/AS<number>!\n");
 239         puts(copyright);
 240         die();
 241 }
 242
 243 static void __noreturn version(void)
 244 {
 245         printf("astraceroute %s, Git id: %s\n", VERSION_LONG, GITVERSION);
 246         puts("autonomous system trace route utility\n"
 247              "http://www.netsniff-ng.org\n");
 248         puts(copyright);
 249         die();
 250 }
 251
 252 static void __assemble_data(uint8_t *packet, size_t len, const char *payload)
 253 {
 254         size_t i;
 255
 256         if (payload == NULL) {
 257                 for (i = 0; i < len; ++i)
 258                         packet[i] = (uint8_t) rand();
 259         } else {
 260                 size_t lmin = min(len, strlen(payload));
 261
 262                 for (i = 0; i < lmin; ++i)
 263                         packet[i] = (uint8_t) payload[i];
 264                 for (i = lmin; i < len; ++i)
 265                         packet[i] = (uint8_t) rand();
 266         }
 267 }
 268
 269 static void __assemble_icmp4(uint8_t *packet, size_t len)
 270 {
 271         struct icmphdr *icmph = (struct icmphdr *) packet;
 272
 273         bug_on(len < sizeof(struct icmphdr));
 274
 275         icmph->type = ICMP_ECHO;
 276         icmph->code = 0;
 277         icmph->checksum = 0;
 278 }
 279
 280 static void __assemble_icmp6(uint8_t *packet, size_t len)
 281 {
 282         struct icmp6hdr *icmp6h = (struct icmp6hdr *) packet;
 283
 284         bug_on(len < sizeof(struct icmp6hdr));
 285
 286         icmp6h->icmp6_type = ICMPV6_ECHO_REQUEST;
 287         icmp6h->icmp6_code = 0;
 288         icmp6h->icmp6_cksum = 0;
 289 }
 290
 291 static void __assemble_tcp(uint8_t *packet, size_t len, int syn, int ack,
 292                            int urg, int fin, int rst, int psh, int ecn,
 293                            int dport)
 294 {
 295         struct tcphdr *tcph = (struct tcphdr *) packet;
 296
 297         bug_on(len < sizeof(struct tcphdr));
 298
 299         tcph->source = htons((uint16_t) rand());
 300         tcph->dest = htons((uint16_t) dport);
 301
 302         tcph->seq = htonl(rand());
 303         tcph->ack_seq = (!!ack ? htonl(rand()) : 0);
 304
 305         tcph->doff = 5;
 306
 307         tcph->syn = !!syn;
 308         tcph->ack = !!ack;
 309         tcph->urg = !!urg;
 310         tcph->fin = !!fin;
 311         tcph->rst = !!rst;
 312         tcph->psh = !!psh;
 313         tcph->ece = !!ecn;
 314         tcph->cwr = !!ecn;
 315
 316         tcph->window = htons((uint16_t) (100 + (rand() % 65435)));
 317         tcph->urg_ptr = (!!urg ? htons((uint16_t) rand()) :  0);
 318         tcph->check = 0;
 319 }
 320
 321 static int assemble_ipv4(uint8_t *packet, size_t len, int ttl, int proto,
 322                          const struct ctx *ctx, const struct sockaddr *dst,
 323                          const struct sockaddr *src)
 324 {
 325         uint8_t *data;
 326         size_t data_len, off_next = 0;
 327         struct iphdr *iph = (struct iphdr *) packet;
 328
 329         bug_on(!src || !dst);
 330         bug_on(src->sa_family != PF_INET || dst->sa_family != PF_INET);
 331         bug_on(len < sizeof(*iph) + min(sizeof(struct tcphdr),
 332                                         sizeof(struct icmphdr)));
 333
 334         iph->ihl = 5;
 335         iph->version = 4;
 336         iph->tos = (uint8_t) ctx->tos;
 337
 338         iph->tot_len = htons((uint16_t) len);
 339         iph->id = htons((uint16_t) rand());
 340
 341         iph->frag_off = ctx->nofrag ? IP_DF : 0;
 342         iph->ttl = (uint8_t) ttl;
 343
 344         iph->saddr = ((const struct sockaddr_in *) src)->sin_addr.s_addr;
 345         iph->daddr = ((const struct sockaddr_in *) dst)->sin_addr.s_addr;
 346
 347         iph->protocol = (uint8_t) proto;
 348
 349         data = packet + sizeof(*iph);
 350         data_len = len - sizeof(*iph);
 351
 352         switch (proto) {
 353         case IPPROTO_TCP:
 354                 __assemble_tcp(data, data_len, ctx->syn, ctx->ack, ctx->urg,
 355                                ctx->fin, ctx->rst, ctx->psh, ctx->ecn, ctx->dport);
 356                 off_next = sizeof(struct tcphdr);
 357                 break;
 358         case IPPROTO_ICMP:
 359                 __assemble_icmp4(data, data_len);
 360                 off_next = sizeof(struct icmphdr);
 361                 break;
 362         default:
 363                 bug();
 364         }
 365
 366         data = packet + sizeof(*iph) + off_next;
 367         data_len = len - sizeof(*iph) - off_next;
 368
 369         __assemble_data(data, data_len, ctx->payload);
 370
 371         iph->check = csum((unsigned short *) packet, ntohs(iph->tot_len) >> 1);
 372
 373         return ntohs(iph->id);
 374 }
 375
 376 static int assemble_ipv6(uint8_t *packet, size_t len, int ttl, int proto,
 377                          const struct ctx *ctx, const struct sockaddr *dst,
 378                          const struct sockaddr *src)
 379 {
 380         uint8_t *data;
 381         size_t data_len, off_next = 0;
 382         struct ip6_hdr *ip6h = (struct ip6_hdr *) packet;
 383
 384         bug_on(!src || !dst);
 385         bug_on(src->sa_family != PF_INET6 || dst->sa_family != PF_INET6);
 386         bug_on(len < sizeof(*ip6h) + min(sizeof(struct tcphdr),
 387                                          sizeof(struct icmp6hdr)));
 388
 389         ip6h->ip6_flow = htonl(rand() & 0x000fffff);
 390         ip6h->ip6_vfc = 0x60;
 391
 392         ip6h->ip6_plen = htons((uint16_t) len - sizeof(*ip6h));
 393         ip6h->ip6_nxt = (uint8_t) proto;
 394         ip6h->ip6_hlim = (uint8_t) ttl;
 395
 396         memcpy(&ip6h->ip6_src, &(((const struct sockaddr_in6 *)
 397                src)->sin6_addr), sizeof(ip6h->ip6_src));
 398         memcpy(&ip6h->ip6_dst, &(((const struct sockaddr_in6 *)
 399                dst)->sin6_addr), sizeof(ip6h->ip6_dst));
 400
 401         data = packet + sizeof(*ip6h);
 402         data_len = len - sizeof(*ip6h);
 403
 404         switch (proto) {
 405         case IPPROTO_TCP:
 406                 __assemble_tcp(data, data_len, ctx->syn, ctx->ack, ctx->urg,
 407                                ctx->fin, ctx->rst, ctx->psh, ctx->ecn, ctx->dport);
 408                 off_next = sizeof(struct tcphdr);
 409                 break;
 410         case IPPROTO_ICMP:
 411         case IPPROTO_ICMPV6:
 412                 __assemble_icmp6(data, data_len);
 413                 off_next = sizeof(struct icmp6hdr);
 414                 break;
 415         default:
 416                 bug();
 417         }
 418
 419         data = packet + sizeof(*ip6h) + off_next;
 420         data_len = len - sizeof(*ip6h) - off_next;
 421
 422         __assemble_data(data, data_len, ctx->payload);
 423
 424         return ntohl(ip6h->ip6_flow) & 0x000fffff;
 425 }
 426
 427 static int check_ipv4(uint8_t *packet, size_t len, int ttl __maybe_unused,
 428                       int id, const struct sockaddr *ss)
 429 {
 430         struct iphdr *iph = (struct iphdr *) packet;
 431         struct iphdr *iph_inner;
 432         struct icmphdr *icmph;
 433
 434         if (iph->protocol != IPPROTO_ICMP)
 435                 return -EINVAL;
 436         if (iph->daddr != ((const struct sockaddr_in *) ss)->sin_addr.s_addr)
 437                 return -EINVAL;
 438
 439         icmph = (struct icmphdr *) (packet + sizeof(struct iphdr));
 440         if (icmph->type != ICMP_TIME_EXCEEDED)
 441                 return -EINVAL;
 442         if (icmph->code != ICMP_EXC_TTL)
 443                 return -EINVAL;
 444
 445         iph_inner = (struct iphdr *) (packet + sizeof(struct iphdr) +
 446                                       sizeof(struct icmphdr));
 447         if (ntohs(iph_inner->id) != id)
 448                 return -EINVAL;
 449
 450         return len;
 451 }
 452
 453 static void handle_ipv4(uint8_t *packet, size_t len __maybe_unused,
 454                         int dns_resolv, int latitude)
 455 {
 456         char hbuff[NI_MAXHOST];
 457         struct iphdr *iph = (struct iphdr *) packet;
 458         struct sockaddr_in sd;
 459         struct hostent *hent;
 460         const char *as, *country, *city;
 461
 462         memset(hbuff, 0, sizeof(hbuff));
 463         memset(&sd, 0, sizeof(sd));
 464         sd.sin_family = PF_INET;
 465         sd.sin_addr.s_addr = iph->saddr;
 466
 467         getnameinfo((struct sockaddr *) &sd, sizeof(sd),
 468                     hbuff, sizeof(hbuff), NULL, 0, NI_NUMERICHOST);
 469
 470         as = geoip4_as_name(&sd);
 471         country = geoip4_country_name(&sd);
 472         city = geoip4_city_name(&sd);
 473
 474         if (dns_resolv) {
 475                 hent = gethostbyaddr(&sd.sin_addr, sizeof(sd.sin_addr), PF_INET);
 476                 if (hent)
 477                         printf(" %s (%s)", hent->h_name, hbuff);
 478                 else
 479                         printf(" %s", hbuff);
 480         } else {
 481                 printf(" %s", hbuff);
 482         }
 483         if (as)
 484                 printf(" in %s", as);
 485         if (country) {
 486                 printf(" in %s", country);
 487                 if (city)
 488                         printf(", %s", city);
 489         }
 490         if (latitude)
 491                 printf(" (%f/%f)", geoip4_latitude(&sd), geoip4_longitude(&sd));
 492 }
 493
 494 static int check_ipv6(uint8_t *packet, size_t len, int ttl __maybe_unused,
 495                       int id, const struct sockaddr *ss)
 496 {
 497         struct ip6_hdr *ip6h = (struct ip6_hdr *) packet;
 498         struct ip6_hdr *ip6h_inner;
 499         struct icmp6hdr *icmp6h;
 500
 501         if (ip6h->ip6_nxt != 0x3a)
 502                 return -EINVAL;
 503         if (memcmp(&ip6h->ip6_dst, &(((const struct sockaddr_in6 *)
 504                    ss)->sin6_addr), sizeof(ip6h->ip6_dst)))
 505                 return -EINVAL;
 506
 507         icmp6h = (struct icmp6hdr *) (packet + sizeof(*ip6h));
 508         if (icmp6h->icmp6_type != ICMPV6_TIME_EXCEED)
 509                 return -EINVAL;
 510         if (icmp6h->icmp6_code != ICMPV6_EXC_HOPLIMIT)
 511                 return -EINVAL;
 512
 513         ip6h_inner = (struct ip6_hdr *) (packet + sizeof(*ip6h) + sizeof(*icmp6h));
 514         if ((ntohl(ip6h_inner->ip6_flow) & 0x000fffff) != (uint32_t) id)
 515                 return -EINVAL;
 516
 517         return len;
 518 }
 519
 520 static void handle_ipv6(uint8_t *packet, size_t len __maybe_unused,
 521                         int dns_resolv, int latitude)
 522 {
 523         char hbuff[NI_MAXHOST];
 524         struct ip6_hdr *ip6h = (struct ip6_hdr *) packet;
 525         struct sockaddr_in6 sd;
 526         struct hostent *hent;
 527         const char *as, *country, *city;
 528
 529         memset(hbuff, 0, sizeof(hbuff));
 530         memset(&sd, 0, sizeof(sd));
 531         sd.sin6_family = PF_INET6;
 532         memcpy(&sd.sin6_addr, &ip6h->ip6_src, sizeof(ip6h->ip6_src));
 533
 534         getnameinfo((struct sockaddr *) &sd, sizeof(sd),
 535                     hbuff, sizeof(hbuff), NULL, 0, NI_NUMERICHOST);
 536
 537         as = geoip6_as_name(&sd);
 538         country = geoip6_country_name(&sd);
 539         city = geoip6_city_name(&sd);
 540
 541         if (dns_resolv) {
 542                 hent = gethostbyaddr(&sd.sin6_addr, sizeof(sd.sin6_addr), PF_INET6);
 543                 if (hent)
 544                         printf(" %s (%s)", hent->h_name, hbuff);
 545                 else
 546                         printf(" %s", hbuff);
 547         } else {
 548                 printf(" %s", hbuff);
 549         }
 550         if (as)
 551                 printf(" in %s", as);
 552         if (country) {
 553                 printf(" in %s", country);
 554                 if (city)
 555                         printf(", %s", city);
 556         }
 557         if (latitude)
 558                 printf(" (%f/%f)", geoip6_latitude(&sd), geoip6_longitude(&sd));
 559 }
 560
 561 static void show_trace_info(struct ctx *ctx, const struct sockaddr_storage *ss,
 562                             const struct sockaddr_storage *sd)
 563 {
 564         char hbuffs[256], hbuffd[256];
 565
 566         memset(hbuffd, 0, sizeof(hbuffd));
 567         getnameinfo((struct sockaddr *) sd, sizeof(*sd),
 568                     hbuffd, sizeof(hbuffd), NULL, 0, NI_NUMERICHOST);
 569
 570         memset(hbuffs, 0, sizeof(hbuffs));
 571         getnameinfo((struct sockaddr *) ss, sizeof(*ss),
 572                     hbuffs, sizeof(hbuffs), NULL, 0, NI_NUMERICHOST);
 573
 574         printf("AS path IPv%d TCP trace from %s to %s:%s (%s) with len %zu "
 575                "Bytes, %u max hops\n", ctx->proto == IPPROTO_IP ? 4 : 6,
 576                hbuffs, hbuffd, ctx->port, ctx->host, ctx->totlen, ctx->max_ttl);
 577
 578         printf("Using flags SYN:%d,ACK:%d,ECN:%d,FIN:%d,PSH:%d,RST:%d,URG:%d\n",
 579                ctx->syn, ctx->ack, ctx->ecn, ctx->fin, ctx->psh, ctx->rst, ctx->urg);
 580
 581         if (ctx->payload)
 582                 printf("With payload: \'%s\'\n", ctx->payload);
 583 }
 584
 585 static int get_remote_fd(struct ctx *ctx, struct sockaddr_storage *ss,
 586                          struct sockaddr_storage *sd)
 587 {
 588         int fd = -1, ret, one = 1, af = AF_INET;
 589         struct addrinfo hints, *ahead, *ai;
 590         unsigned char bind_ip[sizeof(struct in6_addr)];
 591
 592         memset(&hints, 0, sizeof(hints));
 593         hints.ai_family = PF_UNSPEC;
 594         hints.ai_socktype = SOCK_STREAM;
 595         hints.ai_protocol = IPPROTO_TCP;
 596         hints.ai_flags = AI_NUMERICSERV;
 597
 598         ret = getaddrinfo(ctx->host, ctx->port, &hints, &ahead);
 599         if (ret < 0)
 600                 panic("Cannot get address info!\n");
 601
 602         for (ai = ahead; ai != NULL && fd < 0; ai = ai->ai_next) {
 603                 if (!((ai->ai_family == PF_INET6 && ctx->proto == IPPROTO_IPV6) ||
 604                       (ai->ai_family == PF_INET  && ctx->proto == IPPROTO_IP)))
 605                         continue;
 606
 607                 fd = socket(ai->ai_family, SOCK_RAW, IPPROTO_RAW);
 608                 if (fd < 0)
 609                         continue;
 610
 611                 memset(ss, 0, sizeof(*ss));
 612                 ret = device_address(ctx->dev, ai->ai_family, ss);
 613                 if (ret < 0 && !ctx->bind_addr)
 614                         panic("Cannot get own device address!\n");
 615
 616                 if (ctx->bind_addr) {
 617                         if (ctx->proto == IPPROTO_IPV6)
 618                                 af = AF_INET6;
 619
 620                         if (inet_pton(af, ctx->bind_addr, &bind_ip) != 1)
 621                                 panic("Address is invalid!\n");
 622
 623                         if (af == AF_INET6) {
 624                                 struct sockaddr_in6 *ss6 = (struct sockaddr_in6 *) ss;
 625                                 memcpy(&ss6->sin6_addr.s6_addr, &bind_ip, sizeof(struct in6_addr));
 626                         } else {
 627                                 struct sockaddr_in *ss4 = (struct sockaddr_in *) ss;
 628                                 memcpy(&ss4->sin_addr.s_addr, &bind_ip, sizeof(struct in_addr));
 629                         }
 630                 }
 631
 632                 ret = bind(fd, (struct sockaddr *) ss, sizeof(*ss));
 633                 if (ret < 0)
 634                         panic("Cannot bind socket!\n");
 635
 636                 memset(sd, 0, sizeof(*sd));
 637                 memcpy(sd, ai->ai_addr, ai->ai_addrlen);
 638
 639                 ctx->sd_len = ai->ai_addrlen;
 640                 ctx->dport = strtoul(ctx->port, NULL, 10);
 641
 642                 ret = setsockopt(fd, ctx->proto, IP_HDRINCL, &one, sizeof(one));
 643                 if (ret < 0)
 644                         panic("Kernel does not support IP_HDRINCL!\n");
 645
 646                 if (ai->ai_family == PF_INET6) {
 647                         struct sockaddr_in6 *sd6 = (struct sockaddr_in6 *) sd;
 648
 649                         sd6->sin6_port = 0;
 650                 }
 651
 652                 break;
 653         }
 654
 655         freeaddrinfo(ahead);
 656
 657         if (fd < 0)
 658                 panic("Cannot create socket! Does remote "
 659                       "support IPv%d?!\n",
 660                       ctx->proto == IPPROTO_IP ? 4 : 6);
 661
 662         return fd;
 663 }
 664
 665 static void inject_filter(struct ctx *ctx, int fd)
 666 {
 667         struct sock_fprog bpf_ops;
 668
 669         enable_kernel_bpf_jit_compiler();
 670
 671         memset(&bpf_ops, 0, sizeof(bpf_ops));
 672         bpf_ops.filter = (struct sock_filter *) af_ops[ctx->proto].filter;
 673         bpf_ops.len = af_ops[ctx->proto].flen;
 674
 675         bpf_attach_to_sock(fd, &bpf_ops);
 676 }
 677
 678 static int __process_node(struct ctx *ctx, int fd, int fd_cap, int ttl,
 679                           int inner_proto, uint8_t *pkt_snd, uint8_t *pkt_rcv,
 680                           const struct sockaddr_storage *ss,
 681                           const struct sockaddr_storage *sd, struct timeval *diff)
 682 {
 683         int pkt_id, ret, timeout;
 684         struct pollfd pfd;
 685         struct timeval start, end;
 686
 687         prepare_polling(fd_cap, &pfd);
 688
 689         memset(pkt_snd, 0, ctx->totlen);
 690         pkt_id = af_ops[ctx->proto].assembler(pkt_snd, ctx->totlen, ttl,
 691                                               inner_proto, ctx,
 692                                               (const struct sockaddr *) sd,
 693                                               (const struct sockaddr *) ss);
 694
 695         ret = sendto(fd, pkt_snd, ctx->totlen, 0, (struct sockaddr *) sd,
 696                      ctx->sd_len);
 697         if (ret < 0)
 698                 panic("sendto failed: %s\n", strerror(errno));
 699
 700         bug_on(gettimeofday(&start, NULL));
 701
 702         timeout = (ctx->timeout > 0 ? ctx->timeout : 2) * 1000;
 703
 704         ret = poll(&pfd, 1, timeout);
 705         if (ret > 0 && pfd.revents & POLLIN && sigint == 0) {
 706                 bug_on(gettimeofday(&end, NULL));
 707                 if (diff)
 708                         timersub(&end, &start, diff);
 709
 710                 ret = recvfrom(fd_cap, pkt_rcv, ctx->rcvlen, 0, NULL, NULL);
 711                 if (ret < (int) (sizeof(struct ethhdr) + af_ops[ctx->proto].min_len_icmp))
 712                         return -EIO;
 713
 714                 return af_ops[ctx->proto].check(pkt_rcv + sizeof(struct ethhdr),
 715                                                 ret - sizeof(struct ethhdr), ttl,
 716                                                 pkt_id, (const struct sockaddr *) ss);
 717         } else {
 718                 return -EIO;
 719         }
 720
 721         return 0;
 722 }
 723
 724 static void timerdiv(const unsigned long divisor, const struct timeval *tv,
 725                      struct timeval *result)
 726 {
 727         uint64_t x = ((uint64_t) tv->tv_sec * 1000 * 1000 + tv->tv_usec) / divisor;
 728
 729         result->tv_sec = x / 1000 / 1000;
 730         result->tv_usec = x % (1000 * 1000);
 731 }
 732
 733 static int timevalcmp(const void *t1, const void *t2)
 734 {
 735         if (timercmp((struct timeval *) t1, (struct timeval *) t2, <))
 736                 return -1;
 737         if (timercmp((struct timeval *) t1, (struct timeval *) t2, >))
 738                 return  1;
 739
 740         return 0;
 741 }
 742
 743 static int __process_time(struct ctx *ctx, int fd, int fd_cap, int ttl,
 744                           int inner_proto, uint8_t *pkt_snd, uint8_t *pkt_rcv,
 745                           const struct sockaddr_storage *ss,
 746                           const struct sockaddr_storage *sd)
 747 {
 748         size_t i, j = 0;
 749         int good = 0, ret = -EIO, idx, ret_good = -EIO;
 750         struct timeval probes[9], *tmp, sum, res;
 751         uint8_t *trash = xmalloc(ctx->rcvlen);
 752         char *cwait[] = { "-", "\\", "|", "/" };
 753         const char *proto_short[] = {
 754                 [IPPROTO_TCP]           =       "t",
 755                 [IPPROTO_ICMP]          =       "i",
 756                 [IPPROTO_ICMPV6]        =       "i",
 757         };
 758
 759         memset(probes, 0, sizeof(probes));
 760         for (i = 0; i < array_size(probes) && sigint == 0; ++i) {
 761                 ret = __process_node(ctx, fd, fd_cap, ttl, inner_proto,
 762                                      pkt_snd, good == 0 ? pkt_rcv : trash,
 763                                      ss, sd, &probes[i]);
 764                 if (ret > 0) {
 765                         if (good == 0)
 766                                 ret_good = ret;
 767                         good++;
 768                 }
 769
 770                 if (good == 0 && ctx->queries == (int) i)
 771                         break;
 772
 773                 usleep(50000);
 774
 775                 printf("\r%2d: %s", ttl, cwait[j++]);
 776                 fflush(stdout);
 777                 if (j >= array_size(cwait))
 778                         j = 0;
 779         }
 780
 781         if (good == 0) {
 782                 xfree(trash);
 783                 return -EIO;
 784         }
 785
 786         tmp = xcalloc(good, sizeof(struct timeval));
 787         for (i = j = 0; i < array_size(probes); ++i) {
 788                 if (probes[i].tv_sec == 0 && probes[i].tv_usec == 0)
 789                         continue;
 790                 tmp[j].tv_sec = probes[i].tv_sec;
 791                 tmp[j].tv_usec = probes[i].tv_usec;
 792                 j++;
 793         }
 794
 795         qsort(tmp, j, sizeof(struct timeval), timevalcmp);
 796
 797         printf("\r%2d: %s[", ttl, proto_short[inner_proto]);
 798         idx = j / 2;
 799         switch (j % 2) {
 800         case 0:
 801                 timeradd(&tmp[idx], &tmp[idx - 1], &sum);
 802                 timerdiv(2, &sum, &res);
 803                 if (res.tv_sec > 0)
 804                         printf("%lu sec ", res.tv_sec);
 805                 printf("%7lu us", res.tv_usec);
 806                 break;
 807         case 1:
 808                 if (tmp[idx].tv_sec > 0)
 809                         printf("%lu sec ", tmp[idx].tv_sec);
 810                 printf("%7lu us", tmp[idx].tv_usec);
 811                 break;
 812         }
 813         printf("]");
 814
 815         xfree(tmp);
 816         xfree(trash);
 817
 818         return ret_good;
 819 }
 820
 821 static int __probe_remote(struct ctx *ctx, int fd, int fd_cap, int ttl,
 822                           uint8_t *pkt_snd, uint8_t *pkt_rcv,
 823                           const struct sockaddr_storage *ss,
 824                           const struct sockaddr_storage *sd,
 825                           int inner_proto)
 826 {
 827         int ret = -EIO, tries = ctx->queries;
 828
 829         while (tries-- > 0 && sigint == 0) {
 830                 ret = __process_time(ctx, fd, fd_cap, ttl, inner_proto,
 831                                      pkt_snd, pkt_rcv, ss, sd);
 832                 if (ret < 0)
 833                         continue;
 834
 835                 af_ops[ctx->proto].handler(pkt_rcv + sizeof(struct ethhdr),
 836                                            ret - sizeof(struct ethhdr),
 837                                            ctx->dns_resolv, ctx->latitude);
 838                 if (ctx->show) {
 839                         struct pkt_buff *pkt;
 840
 841                         printf("\n");
 842                         pkt = pkt_alloc(pkt_rcv, ret);
 843                         hex_ascii(pkt);
 844                         tprintf_flush();
 845                         pkt_free(pkt);
 846                 }
 847
 848                 break;
 849         }
 850
 851         return ret;
 852 }
 853
 854 static int __process_ttl(struct ctx *ctx, int fd, int fd_cap, int ttl,
 855                          uint8_t *pkt_snd, uint8_t *pkt_rcv,
 856                          const struct sockaddr_storage *ss,
 857                          const struct sockaddr_storage *sd)
 858 {
 859         int ret = -EIO;
 860         size_t i;
 861         const int inner_protos[] = {
 862                 IPPROTO_TCP,
 863                 IPPROTO_ICMP,
 864         };
 865
 866         printf("%2d: ", ttl);
 867         fflush(stdout);
 868
 869         for (i = 0; i < array_size(inner_protos) && sigint == 0; ++i) {
 870                 ret = __probe_remote(ctx, fd, fd_cap, ttl, pkt_snd, pkt_rcv, ss, sd,
 871                                      inner_protos[i]);
 872                 if (ret > 0)
 873                         break;
 874         }
 875
 876         if (ret <= 0)
 877                 printf("\r%2d: ?[ no answer]", ttl);
 878         if (ctx->show == 0)
 879                 printf("\n");
 880         if (ctx->show && ret <= 0)
 881                 printf("\n\n");
 882
 883         fflush(stdout);
 884         return 0;
 885 }
 886
 887 static int main_trace(struct ctx *ctx)
 888 {
 889         int fd, fd_cap, ifindex, ttl;
 890         struct ring dummy_ring;
 891         struct sockaddr_storage ss, sd;
 892         uint8_t *pkt_snd, *pkt_rcv;
 893
 894         fd = get_remote_fd(ctx, &ss, &sd);
 895         fd_cap = pf_socket();
 896
 897         inject_filter(ctx, fd_cap);
 898
 899         ifindex = device_ifindex(ctx->dev);
 900         bind_ring_generic(fd_cap, &dummy_ring, ifindex, false);
 901
 902         if (ctx->totlen < af_ops[ctx->proto].min_len_tcp) {
 903                 ctx->totlen = af_ops[ctx->proto].min_len_tcp;
 904                 if (ctx->payload)
 905                         ctx->totlen += strlen(ctx->payload);
 906         }
 907
 908         ctx->rcvlen = device_mtu(ctx->dev) - sizeof(struct ethhdr);
 909         if (ctx->totlen >= ctx->rcvlen)
 910                 panic("Packet len exceeds device MTU!\n");
 911
 912         pkt_snd = xmalloc(ctx->totlen);
 913         pkt_rcv = xmalloc(ctx->rcvlen);
 914
 915         show_trace_info(ctx, &ss, &sd);
 916
 917         for (ttl = ctx->init_ttl; ttl <= ctx->max_ttl && sigint == 0; ++ttl)
 918                 __process_ttl(ctx, fd, fd_cap, ttl, pkt_snd, pkt_rcv,
 919                               &ss, &sd);
 920
 921         xfree(pkt_snd);
 922         xfree(pkt_rcv);
 923
 924         close(fd_cap);
 925         close(fd);
 926
 927         return 0;
 928 }
 929
 930 int main(int argc, char **argv)
 931 {
 932         int c, opt_index, ret;
 933         struct ctx ctx;
 934
 935         setfsuid(getuid());
 936         setfsgid(getgid());
 937
 938         srand(time(NULL));
 939
 940         memset(&ctx, 0, sizeof(ctx));
 941         ctx.init_ttl = 1;
 942         ctx.max_ttl = 30;
 943         ctx.queries = 2;
 944         ctx.timeout = 2;
 945         ctx.proto = IPPROTO_IP;
 946         ctx.payload = NULL;
 947         ctx.dev = xstrdup("eth0");
 948         ctx.port = xstrdup("80");
 949         ctx.bind_addr = NULL;
 950
 951         while ((c = getopt_long(argc, argv, short_options, long_options,
 952                 &opt_index)) != EOF) {
 953                 switch (c) {
 954                 case 'h':
 955                         help();
 956                         break;
 957                 case 'v':
 958                         version();
 959                         break;
 960                 case 'u':
 961                         update_geoip();
 962                         die();
 963                         break;
 964                 case 'H':
 965                         ctx.host = xstrdup(optarg);
 966                         break;
 967                 case 'p':
 968                         if (ctx.port)
 969                                 xfree(ctx.port);
 970                         ctx.port = xstrdup(optarg);
 971                         break;
 972                 case 'n':
 973                         ctx.dns_resolv = 0;
 974                         break;
 975                 case '4':
 976                         ctx.proto = IPPROTO_IP;
 977                         break;
 978                 case '6':
 979                         ctx.proto = IPPROTO_IPV6;
 980                         break;
 981                 case 'Z':
 982                         ctx.show = 1;
 983                         break;
 984                 case 'N':
 985                         ctx.dns_resolv = 1;
 986                         break;
 987                 case 'f':
 988                         ctx.init_ttl = atoi(optarg);
 989                         if (ctx.init_ttl <= 0)
 990                                 help();
 991                         break;
 992                 case 'm':
 993                         ctx.max_ttl = atoi(optarg);
 994                         if (ctx.max_ttl <= 0)
 995                                 help();
 996                         break;
 997                 case 'b':
 998                         ctx.bind_addr = xstrdup(optarg);
 999                         break;
1000                 case 'i':
1001                 case 'd':
1002                         free(ctx.dev);
1003                         ctx.dev = xstrdup(optarg);
1004                         break;
1005                 case 'q':
1006                         ctx.queries = atoi(optarg);
1007                         if (ctx.queries <= 0)
1008                                 help();
1009                         break;
1010                 case 'x':
1011                         ctx.timeout = atoi(optarg);
1012                         if (ctx.timeout <= 0)
1013                                 help();
1014                         break;
1015                 case 'L':
1016                         ctx.latitude = 1;
1017                         break;
1018                 case 'S':
1019                         ctx.syn = 1;
1020                         break;
1021                 case 'A':
1022                         ctx.ack = 1;
1023                         break;
1024                 case 'F':
1025                         ctx.fin = 1;
1026                         break;
1027                 case 'U':
1028                         ctx.urg = 1;
1029                         break;
1030                 case 'P':
1031                         ctx.psh = 1;
1032                         break;
1033                 case 'R':
1034                         ctx.rst = 1;
1035                         break;
1036                 case 'E':
1037                         ctx.syn = 1;
1038                         ctx.ecn = 1;
1039                         break;
1040                 case 't':
1041                         ctx.tos = atoi(optarg);
1042                         if (ctx.tos < 0)
1043                                 help();
1044                         break;
1045                 case 'G':
1046                         ctx.nofrag = 1;
1047                         break;
1048                 case 'X':
1049                         ctx.payload = xstrdup(optarg);
1050                         break;
1051                 case 'l':
1052                         ctx.totlen = strtoul(optarg, NULL, 10);
1053                         if (ctx.totlen == 0)
1054                                 help();
1055                         break;
1056                 case '?':
1057                         switch (optopt) {
1058                         case 'H':
1059                         case 'p':
1060                         case 'f':
1061                         case 'm':
1062                         case 'i':
1063                         case 'd':
1064                         case 'q':
1065                         case 'x':
1066                         case 'X':
1067                         case 't':
1068                         case 'l':
1069                                 panic("Option -%c requires an argument!\n",
1070                                       optopt);
1071                         default:
1072                                 if (isprint(optopt))
1073                                         printf("Unknown option character `0x%X\'!\n", optopt);
1074                                 die();
1075                 }
1076                 default:
1077                         break;
1078                 }
1079         }
1080
1081         if (argc < 3 || !ctx.host || !ctx.port || ctx.init_ttl > ctx.max_ttl ||
1082             ctx.init_ttl > MAXTTL || ctx.max_ttl > MAXTTL)
1083                 help();
1084
1085         if (!device_up_and_running(ctx.dev))
1086                 panic("Networking device not up and running!\n");
1087         if (device_mtu(ctx.dev) <= ctx.totlen)
1088                 panic("Packet larger than device MTU!\n");
1089
1090         register_signal(SIGHUP, signal_handler);
1091         register_signal(SIGINT, signal_handler);
1092         register_signal(SIGQUIT, signal_handler);
1093         register_signal(SIGTERM, signal_handler);
1094
1095         tprintf_init();
1096         init_geoip(1);
1097
1098         ret = main_trace(&ctx);
1099
1100         destroy_geoip();
1101         tprintf_cleanup();
1102
1103         free(ctx.dev);
1104         free(ctx.host);
1105         free(ctx.port);
1106         free(ctx.bind_addr);
1107         free(ctx.payload);
1108
1109         return ret;
1110 }