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