mdw@git.distorted.org.uk Git - tripe/blob - proxy/tripe-mitm.c

   1 /* -*-c-*-
   2  *
   3  * An evil proxy for TrIPE
   4  *
   5  * (c) 2001 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Trivial IP Encryption (TrIPE).
  11  *
  12  * TrIPE is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * TrIPE is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with TrIPE; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 /*----- Header files ------------------------------------------------------*/
  28
  29 #include "config.h"
  30
  31 #include <assert.h>
  32 #include <errno.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <time.h>
  37
  38 #include <sys/types.h>
  39 #include <sys/time.h>
  40 #include <unistd.h>
  41 #include <fcntl.h>
  42
  43 #include <sys/socket.h>
  44 #include <netinet/in.h>
  45 #include <arpa/inet.h>
  46 #include <netdb.h>
  47
  48 #include <mLib/alloc.h>
  49 #include <mLib/dstr.h>
  50 #include <mLib/fdflags.h>
  51 #include <mLib/mdwopt.h>
  52 #include <mLib/quis.h>
  53 #include <mLib/report.h>
  54 #include <mLib/sel.h>
  55 #include <mLib/sub.h>
  56 #include <mLib/tv.h>
  57
  58 #include <catacomb/buf.h>
  59
  60 #include <catacomb/key.h>
  61
  62 #include <catacomb/mp.h>
  63 #include <catacomb/mprand.h>
  64 #include <catacomb/dh.h>
  65
  66 #include <catacomb/noise.h>
  67 #include <catacomb/rand.h>
  68 #include <catacomb/rc4.h>
  69
  70 #include "util.h"
  71
  72 /*----- Data structures ---------------------------------------------------*/
  73
  74 typedef struct peer {
  75   sel_file sf;
  76   dh_pub kpub;
  77   const char *name;
  78   struct filter *f;
  79 } peer;
  80
  81 typedef struct filter {
  82   struct filter *next;
  83   peer *p_from, *p_to;
  84   void (*func)(struct filter */*f*/, const octet */*buf*/, size_t /*sz*/);
  85   void *state;
  86 } filter;
  87
  88 typedef struct qnode {
  89   octet *buf;
  90   size_t sz;
  91 } qnode;
  92
  93 /*----- Static variables --------------------------------------------------*/
  94
  95 #define PKBUFSZ 65536
  96
  97 static sel_state sel;
  98 static peer peers[2];
  99 static unsigned npeer = 0;
 100 static key_file keys;
 101 static grand *rng;
 102
 103 #define PASS(f, buf, sz) ((f) ? (f)->func((f), (buf), (sz)) : (void)0)
 104 #define RND(i) (rng->ops->range(rng, (i)))
 105
 106 /*----- Peer management ---------------------------------------------------*/
 107
 108 static void dopacket(int fd, unsigned mode, void *vv)
 109 {
 110   octet buf[PKBUFSZ];
 111   peer *p = vv;
 112   int r = read(fd, buf, sizeof(buf));
 113   if (r >= 0) {
 114     printf("recv from `%s'\n", p->name);
 115     PASS(p->f, buf, r);
 116   }
 117 }
 118
 119 static void addpeer(unsigned ac, char **av)
 120 {
 121   key_packstruct kps[DH_PUBFETCHSZ];
 122   key_packdef *kp;
 123   struct hostent *h;
 124   struct sockaddr_in sin;
 125   int len = PKBUFSZ;
 126   peer *p;
 127   int fd;
 128   int e;
 129
 130   if (ac != 4)
 131     die(1, "syntax: peer:NAME:PORT:ADDR:PORT");
 132   if (npeer >= 2)
 133     die(1, "enough peers already");
 134   p = &peers[npeer++];
 135   p->name = xstrdup(av[0]);
 136   kp = key_fetchinit(dh_pubfetch, kps, &p->kpub);
 137   e = key_fetchbyname(kp, &keys, av[0]);
 138   key_fetchdone(kp);
 139   if (e)
 140     die(1, "key_fetch `%s': %s", av[0], key_strerror(e));
 141   if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
 142     die(1, "socket: %s", strerror(errno));
 143   fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 144   memset(&sin, 0, sizeof(sin));
 145   sin.sin_family = AF_INET;
 146   sin.sin_addr.s_addr = INADDR_ANY;
 147   sin.sin_port = htons(atoi(av[1]));
 148   if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
 149     die(1, "bind: %s", strerror(errno));
 150   memset(&sin, 0, sizeof(sin));
 151   sin.sin_family = AF_INET;
 152   if ((h = gethostbyname(av[2])) == 0)
 153     die(1, "gethostbyname `%s'", av[2]);
 154   if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
 155       setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)))
 156     die(1, "setsockopt: %s", strerror(errno));
 157   memcpy(&sin.sin_addr, h->h_addr, sizeof(sin.sin_addr));
 158   sin.sin_port = htons(atoi(av[3]));
 159   if (connect(fd, (struct sockaddr *)&sin, sizeof(sin)))
 160     die(1, "connect: %s", strerror(errno));
 161   sel_initfile(&sel, &p->sf, fd, SEL_READ, dopacket, p);
 162   sel_addfile(&p->sf);
 163 }
 164
 165 /*----- Fork filter -------------------------------------------------------*/
 166
 167 typedef struct forknode {
 168   struct forknode *next;
 169   filter *f;
 170 } forknode;
 171
 172 typedef struct forkfilt {
 173   const char *name;
 174   forknode *fn;
 175 } forkfilt;
 176
 177 static void dofork(filter *f, const octet *buf, size_t sz)
 178 {
 179   forkfilt *ff = f->state;
 180   forknode *fn;
 181   unsigned i = 0;
 182
 183   ff = f->state;
 184   for (fn = ff->fn; fn; fn = fn->next) {
 185     printf("fork branch %u of fork `%s'\n", i++, ff->name);
 186     PASS(fn->f, buf, sz);
 187   }
 188   printf("fork branch %u of fork `%s'\n", i++, ff->name);
 189   PASS(f->next, buf, sz);
 190 }
 191
 192 static void addfork(filter *f, unsigned ac, char **av)
 193 {
 194   forkfilt *ff;
 195   if (ac != 1)
 196     die(1, "syntax: filt:fork:NAME");
 197   ff = CREATE(forkfilt);
 198   ff->name = xstrdup(av[0]);
 199   ff->fn = 0;
 200   f->func = dofork;
 201   f->state = ff;
 202 }
 203
 204 static void nextfork(unsigned ac, char **av)
 205 {
 206   unsigned i, j;
 207   filter *f;
 208   forkfilt *ff;
 209   forknode *fn, **ffn;
 210   peer *p;
 211
 212   if (ac < 1)
 213     die(1, "syntax: next:NAME:...");
 214   for (i = 0; i < 2; i++) {
 215     p = &peers[i];
 216     for (f = p->f; f; f = f->next) {
 217       if (f->func != dofork)
 218         continue;
 219       ff = f->state;
 220       for (j = 0; j < ac; j++) {
 221         if (strcmp(av[j], ff->name) == 0)
 222           goto match;
 223       }
 224       continue;
 225     match:
 226       fn = CREATE(forknode);
 227       for (ffn = &ff->fn; *ffn; ffn = &(*ffn)->next)
 228         ;
 229       fn->f = f->next;
 230       f->next = 0;
 231       fn->next = 0;
 232       *ffn = fn;
 233     }
 234   }
 235 }
 236
 237 /*----- Corrupt filter ----------------------------------------------------*/
 238
 239 typedef struct corrupt {
 240   unsigned p_corrupt;
 241 } corrupt;
 242
 243 static void docorrupt(filter *f, const octet *buf, size_t sz)
 244 {
 245   corrupt *c = f->state;
 246   octet b[PKBUFSZ];
 247   memcpy(b, buf, sz);
 248
 249   while (!RND(c->p_corrupt)) {
 250     puts("corrupt packet");
 251     b[RND(sz)] ^= RND(256);
 252   }
 253   PASS(f->next, b, sz);
 254 }
 255
 256 static void addcorrupt(filter *f, unsigned ac, char **av)
 257 {
 258   corrupt *c;
 259   if (ac > 1)
 260     die(1, "syntax: filt:corrupt[:P-CORRUPT]");
 261   c = CREATE(corrupt);
 262   if (ac > 0)
 263     c->p_corrupt = atoi(av[0]);
 264   else
 265     c->p_corrupt = 5;
 266   f->state = c;
 267   f->func = docorrupt;
 268 }
 269
 270 /*----- Drop filter -------------------------------------------------------*/
 271
 272 typedef struct drop {
 273   unsigned p_drop;
 274 } drop;
 275
 276 static void dodrop(filter *f, const octet *buf, size_t sz)
 277 {
 278   drop *d = f->state;
 279
 280   if (!RND(d->p_drop))
 281     puts("drop packet");
 282   else
 283     PASS(f->next, buf, sz);
 284 }
 285
 286 static void adddrop(filter *f, unsigned ac, char **av)
 287 {
 288   drop *d;
 289   if (ac > 1)
 290     die(1, "syntax: filt:drop[:P-DROP]");
 291   d = CREATE(drop);
 292   if (ac > 0)
 293     d->p_drop = atoi(av[0]);
 294   else
 295     d->p_drop = 5;
 296   f->state = d;
 297   f->func = dodrop;
 298 }
 299
 300 /*----- Delay filter ------------------------------------------------------*/
 301
 302 typedef struct delaynode {
 303   unsigned flag;
 304   sel_timer tm;
 305   unsigned i;
 306   struct delay *d;
 307   octet *buf;
 308   size_t sz;
 309   unsigned seq;
 310 } delaynode;
 311
 312 typedef struct delay {
 313   unsigned max, n;
 314   unsigned long t;
 315   unsigned p_replay;
 316   filter *f;
 317   delaynode *q;
 318 } delay;
 319
 320 static void dtimer(struct timeval *tv, void *vv);
 321
 322 static void dinsert(delaynode *dn)
 323 {
 324   struct timeval tv;
 325   sel_timer *ta, *tb;
 326   unsigned long tdelta = RND(dn->d->t);
 327   gettimeofday(&tv, 0);
 328   TV_ADDL(&tv, &tv, 0, tdelta);
 329   assert(!dn->flag);
 330   sel_addtimer(&sel, &dn->tm, &tv, dtimer, dn);
 331   dn->flag = 1;
 332   for (ta = tb = sel.timers; ta; ta = ta->next) {
 333     ta = ta->next; if (!ta) break; assert(ta != tb);
 334     ta = ta->next; if (!ta) break; assert(ta != tb);
 335     tb = tb->next;
 336   }
 337   printf(" delay %lu usecs", tdelta);
 338 }
 339
 340 static void dsend(delaynode *dn, unsigned force)
 341 {
 342   delay *d = dn->d;
 343   delaynode *ddn;
 344   fputs(" send...\n", stdout);
 345   assert(dn->buf);
 346   PASS(d->f->next, dn->buf, dn->sz);
 347   fputs("delay ...", stdout);
 348   if (!force)
 349     dinsert(dn);
 350   else {
 351     xfree(dn->buf);
 352     dn->buf = 0;
 353     d->n--;
 354     if (dn->i < d->n) {
 355       ddn = &d->q[d->n];
 356       sel_rmtimer(&ddn->tm);
 357       sel_addtimer(&sel, &dn->tm, &ddn->tm.tv, dtimer, dn);
 358       dn->flag = 1;
 359       dn->buf = ddn->buf;
 360       dn->sz = ddn->sz;
 361       dn->seq = ddn->seq;
 362       ddn->buf = 0;
 363       ddn->flag = 0;
 364       printf(" move id %u from slot %u to slot %u", ddn->seq, ddn->i, dn->i);
 365     }
 366     { unsigned i; for (i = 0; i < d->n; i++) assert(d->q[i].buf); }
 367     fputs(" remove", stdout);
 368   }
 369 }
 370
 371 static void dtimer(struct timeval *tv, void *vv)
 372 {
 373   delaynode *dn = vv;
 374   printf("delay timer peer `%s' id %u slot %u",
 375          dn->d->f->p_from->name, dn->seq, dn->i);
 376   dn->flag = 0;
 377   dsend(dn, RND(dn->d->p_replay));
 378   fputc('\n', stdout);
 379 }
 380
 381 static void dodelay(filter *f, const octet *buf, size_t sz)
 382 {
 383   delay *d = f->state;
 384   delaynode *dn;
 385   static unsigned seq = 0;
 386
 387   fputs("delay", stdout);
 388   if (d->n == d->max) {
 389     dn = &d->q[RND(d->n)];
 390     printf(" force uid %u", dn->seq);
 391     sel_rmtimer(&dn->tm);
 392     dn->flag = 0;
 393     dsend(dn, 1);
 394     fputc(';', stdout);
 395   }
 396   dn = &d->q[d->n++];
 397   dn->seq = seq++;
 398   printf(" new id %u in slot %u", dn->seq, dn->i);
 399   dn->buf = xmalloc(sz);
 400   dn->sz = sz;
 401   memcpy(dn->buf, buf, sz);
 402   dinsert(dn);
 403   fputc('\n', stdout);
 404 }
 405
 406 static void adddelay(filter *f, unsigned ac, char **av)
 407 {
 408   delay *d;
 409   unsigned i;
 410
 411   if (ac < 1 || ac > 3)
 412     die(1, "syntax: filt:delay:QLEN[:MILLIS:P-REPLAY]");
 413   d = CREATE(delay);
 414   d->max = atoi(av[0]);
 415   if (ac > 1)
 416     d->t = strtoul(av[1], 0, 10);
 417   else
 418     d->t = 100;
 419   d->t *= 1000;
 420   if (ac > 2)
 421     d->p_replay = atoi(av[2]);
 422   else
 423     d->p_replay = 20;
 424   d->n = 0;
 425   d->q = xmalloc(d->max * sizeof(delaynode));
 426   d->f = f;
 427   f->state = d;
 428   f->func = dodelay;
 429   for (i = 0; i < d->max; i++) {
 430     d->q[i].d = d;
 431     d->q[i].i = i;
 432     d->q[i].buf = 0;
 433     d->q[i].flag = 0;
 434   }
 435 }
 436
 437 /*----- Filters -----------------------------------------------------------*/
 438
 439 static void dosend(filter *f, const octet *buf, size_t sz)
 440 {
 441   printf("send to `%s'\n", f->p_to->name);
 442   IGNORE(write(f->p_to->sf.fd, buf, sz));
 443 }
 444
 445 static void addsend(filter *f, unsigned ac, char **av)
 446 {
 447   if (ac)
 448     die(1, "syntax: filt:send");
 449   f->func = dosend;
 450 }
 451
 452 const struct filtab {
 453   const char *name;
 454   void (*func)(filter */*f*/, unsigned /*ac*/, char **/*av*/);
 455 } filtab[] = {
 456   { "send",     addsend },
 457   { "fork",     addfork },
 458   { "delay",    adddelay },
 459   { "drop",     adddrop },
 460   { "corrupt",  addcorrupt },
 461   { 0,          0 }
 462 };
 463
 464 static void dofilter(peer *from, peer *to, unsigned ac, char **av)
 465 {
 466   filter **ff, *f = CREATE(filter);
 467   const struct filtab *ft;
 468   if (ac < 1)
 469     die(1, "syntax: {l,r,}filt:NAME:...");
 470   f->next = 0;
 471   f->p_from = from;
 472   f->p_to = to;
 473   f->state = 0;
 474   for (ff = &from->f; *ff; ff = &(*ff)->next)
 475     ;
 476   *ff = f;
 477   for (ft = filtab; ft->name; ft++) {
 478     if (strcmp(av[0], ft->name) == 0) {
 479       ft->func(f, ac - 1, av + 1);
 480       return;
 481     }
 482   }
 483   die(1, "unknown filter `%s'", av[0]);
 484 }
 485
 486 /*----- Flooding ----------------------------------------------------------*/
 487
 488 typedef struct flood {
 489   peer *p;
 490   unsigned type;
 491   size_t sz;
 492   unsigned long t;
 493   sel_timer tm;
 494 } flood;
 495
 496 static void setflood(flood *f);
 497
 498 static void floodtimer(struct timeval *tv, void *vv)
 499 {
 500   flood *f = vv;
 501   octet buf[PKBUFSZ];
 502   size_t sz;
 503
 504   sz = RND(f->sz);
 505   sz += RND(f->sz);
 506   sz += RND(f->sz);
 507   sz += RND(f->sz);
 508   sz /= 2;
 509
 510   rng->ops->fill(rng, buf, sz);
 511   if (f->type < 0x100)
 512     buf[0] = f->type;
 513   puts("flood packet");
 514   PASS(f->p->f, buf, sz);
 515   setflood(f);
 516 }
 517
 518 static void setflood(flood *f)
 519 {
 520   struct timeval tv;
 521   gettimeofday(&tv, 0);
 522   TV_ADDL(&tv, &tv, 0, RND(f->t));
 523   sel_addtimer(&sel, &f->tm, &tv, floodtimer, f);
 524 }
 525
 526 static void doflood(peer *p, unsigned ac, char **av)
 527 {
 528   flood *f;
 529   if (ac > 3)
 530     die(1, "syntax: flood[:TYPE:MILLIS:SIZE]");
 531   f = CREATE(flood);
 532   f->p = p;
 533   if (ac > 0)
 534     f->type = strtoul(av[0], 0, 16);
 535   else
 536     f->type = 0x100;
 537   if (ac > 1)
 538     f->t = atoi(av[1]);
 539   else
 540     f->t = 10;
 541   if (ac > 2)
 542     f->sz = atoi(av[2]);
 543   else
 544     f->sz = 128;
 545   f->t *= 1000;
 546   setflood(f);
 547 }
 548
 549 /*----- Configuration commands --------------------------------------------*/
 550
 551 static void parse(char *p);
 552
 553 static void addflood(unsigned ac, char **av) {
 554   doflood(&peers[0], ac, av);
 555   doflood(&peers[1], ac, av);
 556 }
 557 static void addlflood(unsigned ac, char **av) {
 558   doflood(&peers[0], ac, av);
 559 }
 560 static void addrflood(unsigned ac, char **av) {
 561   doflood(&peers[1], ac, av);
 562 }
 563
 564 static void addfilter(unsigned ac, char **av) {
 565   dofilter(&peers[0], &peers[1], ac, av);
 566   dofilter(&peers[1], &peers[0], ac, av);
 567 }
 568 static void addlfilter(unsigned ac, char **av) {
 569   dofilter(&peers[0], &peers[1], ac, av);
 570 }
 571 static void addrfilter(unsigned ac, char **av) {
 572   dofilter(&peers[1], &peers[0], ac, av);
 573 }
 574
 575 static void include(unsigned ac, char **av)
 576 {
 577   FILE *fp;
 578   dstr d = DSTR_INIT;
 579   if (!ac)
 580     die(1, "syntax: include:FILE:...");
 581   while (*av) {
 582     if ((fp = fopen(*av, "r")) == 0)
 583       die(1, "fopen `%s': %s", *av, strerror(errno));
 584     while (dstr_putline(&d, fp) != EOF) {
 585       parse(d.buf);
 586       DRESET(&d);
 587     }
 588     fclose(fp);
 589     av++;
 590   }
 591 }
 592
 593 const struct cmdtab {
 594   const char *name;
 595   void (*func)(unsigned /*ac*/, char **/*av*/);
 596 } cmdtab[] = {
 597   { "peer",     addpeer },
 598   { "include",  include },
 599   { "filt",     addfilter },
 600   { "lfilt",    addlfilter },
 601   { "rfilt",    addrfilter },
 602   { "next",     nextfork },
 603   { "flood",    addflood },
 604   { "lflood",   addlflood },
 605   { "rflood",   addrflood },
 606   { 0,          0 }
 607 };
 608
 609 #define AVMAX 16
 610
 611 static void parse(char *p)
 612 {
 613   char *v[AVMAX];
 614   unsigned c = 0;
 615   const struct cmdtab *ct;
 616
 617   p = strtok(p, ":");
 618   if (!p || *p == '#')
 619     return;
 620   do {
 621     v[c++] = p;
 622     p = strtok(0, ":");
 623   } while (p && c < AVMAX - 1);
 624   v[c] = 0;
 625   for (ct = cmdtab; ct->name; ct++) {
 626     if (strcmp(ct->name, v[0]) == 0) {
 627       ct->func(c - 1, v + 1);
 628       return;
 629     }
 630   }
 631   die(1, "unknown command `%s'", v[0]);
 632 }
 633
 634 /*----- Main driver -------------------------------------------------------*/
 635
 636 static void version(FILE *fp)
 637   { pquis(fp, "$, TrIPE version " VERSION "\n"); }
 638
 639 static void usage(FILE *fp)
 640   { pquis(fp, "Usage: $ [-k KEYRING] DIRECTIVE...\n"); }
 641
 642 static void help(FILE *fp)
 643 {
 644   version(fp);
 645   putc('\n', fp);
 646   usage(fp);
 647   fputs("\n\
 648 Options:\n\
 649 \n\
 650 -h, --help              Show this help text.\n\
 651 -v, --version           Show the version number.\n\
 652 -u, --usage             Show terse usage summary.\n\
 653 \n\
 654 -k, --keyring=FILE      Fetch keys from FILE.\n\
 655 \n\
 656 Directives:\n\
 657   peer:NAME:LOCAL-PORT:REMOTE-ADDR:REMOTE-PORT\n\
 658   include:FILE\n\
 659   {,l,r}filt:FILTER:ARGS:...\n\
 660   next:TAG\n\
 661   {,l,r}flood:TYPE:MILLIS:SIZE\n\
 662 \n\
 663 Filters:\n\
 664   send\n\
 665   fork:TAG\n\
 666   delay:QLEN[:MILLIS:P-REPLAY]\n\
 667   drop[:P-DROP]\n\
 668   corrupt[:P-CORRUPT]\n",
 669         fp);
 670 }
 671
 672 int main(int argc, char *argv[])
 673 {
 674   const char *kfname = "keyring.pub";
 675   int i;
 676   unsigned f = 0;
 677   char buf[16];
 678
 679 #define f_bogus 1u
 680
 681   ego(argv[0]);
 682   for (;;) {
 683     static const struct option opt[] = {
 684       { "help",         0,              0,      'h' },
 685       { "version",      0,              0,      'v' },
 686       { "usage",        0,              0,      'u' },
 687       { "keyring",      OPTF_ARGREQ,    0,      'k' },
 688       { 0,              0,              0,      0 }
 689     };
 690     if ((i = mdwopt(argc, argv, "hvuk:", opt, 0, 0, 0)) < 0)
 691       break;
 692     switch (i) {
 693       case 'h':
 694         help(stdout);
 695         exit(0);
 696       case 'v':
 697         version(stdout);
 698         exit(0);
 699       case 'u':
 700         usage(stdout);
 701         exit(0);
 702       case 'k':
 703         kfname = optarg;
 704         break;
 705       default:
 706         f |= f_bogus;
 707         break;
 708     }
 709   }
 710   if (f & f_bogus) {
 711     usage(stderr);
 712     exit(1);
 713   }
 714   rand_noisesrc(RAND_GLOBAL, &noise_source);
 715   rand_seed(RAND_GLOBAL, 160);
 716   rand_get(RAND_GLOBAL, buf, sizeof(buf));
 717   rng = rc4_rand(buf, sizeof(buf));
 718   sel_init(&sel);
 719   if (key_open(&keys, kfname, KOPEN_READ, key_moan, 0))
 720     die(1, "couldn't open `%s': %s", kfname, strerror(errno));
 721   for (i = optind; i < argc; i++)
 722     parse(argv[i]);
 723   if (npeer != 2)
 724     die(1, "need two peers");
 725   for (;;)
 726     sel_select(&sel);
 727
 728 #undef f_bogus
 729 }
 730
 731 /*----- That's all, folks -------------------------------------------------*/