mdw@git.distorted.org.uk Git - tripe/blob - server/peer.c

   1 /* -*-c-*-
   2  *
   3  * Communication with the peer
   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 it under
  13  * the terms of the GNU General Public License as published by the Free
  14  * Software Foundation; either version 3 of the License, or (at your
  15  * option) any later version.
  16  *
  17  * TrIPE is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with TrIPE.  If not, see <https://www.gnu.org/licenses/>.
  24  */
  25
  26 /*----- Header files ------------------------------------------------------*/
  27
  28 #include "tripe.h"
  29
  30 /*----- Global state ------------------------------------------------------*/
  31
  32 sel_file udpsock[NADDRFAM];
  33
  34 /*----- Static variables --------------------------------------------------*/
  35
  36 static sym_table byname;
  37 static addrmap byaddr;
  38 static unsigned nmobile;
  39
  40 /*----- Tunnel table ------------------------------------------------------*/
  41
  42 const tunnel_ops *tunnels[] = {
  43 #ifdef TUN_LINUX
  44   &tun_linux,
  45 #endif
  46 #ifdef TUN_BSD
  47   &tun_bsd,
  48 #endif
  49 #ifdef TUN_UNET
  50   &tun_unet,
  51 #endif
  52   &tun_slip,
  53   0
  54 }, *tun_default;
  55
  56 /*----- Main code ---------------------------------------------------------*/
  57
  58 /* --- @p_pingtype@ --- *
  59  *
  60  * Arguments:   @unsigned msg@ = message type
  61  *
  62  * Returns:     String to describe the message.
  63  */
  64
  65 static const char *p_pingtype(unsigned msg)
  66 {
  67   switch (msg & MSG_TYPEMASK) {
  68     case MISC_PING:
  69     case MISC_PONG:
  70       return "transport-ping";
  71     case MISC_EPING:
  72     case MISC_EPONG:
  73       return "encrypted-ping";
  74     default:
  75       abort();
  76   }
  77 }
  78
  79 /* --- @p_ponged@ --- *
  80  *
  81  * Arguments:   @peer *p@ = peer packet arrived from
  82  *              @unsigned msg@ = message type
  83  *              @buf *b@ = buffer containing payload
  84  *
  85  * Returns:     ---
  86  *
  87  * Use:         Processes a ping response.
  88  */
  89
  90 static void p_ponged(peer *p, unsigned msg, buf *b)
  91 {
  92   uint32 id;
  93   const octet *magic;
  94   ping *pg;
  95
  96   IF_TRACING(T_PEER, {
  97     trace(T_PEER, "peer: received %s reply from %s",
  98           p_pingtype(msg), p->spec.name);
  99     trace_block(T_PACKET, "peer: ping contents", BBASE(b), BSZ(b));
 100   })
 101
 102   if (buf_getu32(b, &id) ||
 103       (magic = buf_get(b, sizeof(pg->magic))) == 0 ||
 104       BLEFT(b)) {
 105     a_warn("PEER", "?PEER", p, "malformed-%s", p_pingtype(msg), A_END);
 106     return;
 107   }
 108
 109   for (pg = p->pings; pg; pg = pg->next) {
 110     if (pg->id == id)
 111       goto found;
 112   }
 113   a_warn("PEER",
 114          "?PEER", p,
 115          "unexpected-%s", p_pingtype(msg),
 116          "0x%08lx", (unsigned long)id,
 117          A_END);
 118   return;
 119
 120 found:
 121   if (memcmp(magic, pg->magic, sizeof(pg->magic)) != 0) {
 122     a_warn("PEER", "?PEER", p, "corrupt-%s", p_pingtype(msg), A_END);
 123     return;
 124   }
 125   p_pingdone(pg, PING_OK);
 126 }
 127
 128 /* --- @p_rxupdstats@ --- *
 129  *
 130  * Arguments:   @peer *p@ = peer to update
 131  *              @size_t n@ = size of incoming packet
 132  *
 133  * Returns:     ---
 134  *
 135  * Use:         Updates the peer's incoming packet statistics.
 136  */
 137
 138 static void p_rxupdstats(peer *p, size_t n)
 139 {
 140   p->st.t_last = time(0);
 141   p->st.n_in++;
 142   p->st.sz_in += n;
 143 }
 144
 145 /* --- @p_encrypt@ --- *
 146  *
 147  * Arguments:   @peer *p@ = peer to encrypt message to
 148  *              @int ty@ message type to send
 149  *              @buf *bin, *bout@ = input and output buffers
 150  *
 151  * Returns:     ---
 152  *
 153  * Use:         Convenience function for packet encryption.  Forces
 154  *              renegotiation when necessary.  Check for the output buffer
 155  *              being broken to find out whether the encryption was
 156  *              successful.
 157  */
 158
 159 static int p_encrypt(peer *p, int ty, buf *bin, buf *bout)
 160 {
 161   int err = ksl_encrypt(&p->ks, ty, bin, bout);
 162
 163   if (err == KSERR_REGEN) {
 164     kx_start(&p->kx, 1);
 165     err = 0;
 166   }
 167   if (!BOK(bout))
 168     err = -1;
 169   return (err);
 170 }
 171
 172 /* --- @p_updateaddr@ --- *
 173  *
 174  * Arguments:   @peer *p@ = pointer to peer block
 175  *              @const addr *a@ = address to associate with this peer
 176  *
 177  * Returns:     Zero if the address was changed; @+1@ if it was already
 178  *              right.
 179  *
 180  * Use:         Updates our idea of @p@'s address.
 181  */
 182
 183 int p_updateaddr(peer *p, const addr *a)
 184 {
 185   peer *q;
 186   peer_byaddr *pa, *qa;
 187   int ix;
 188   unsigned f;
 189
 190   /* --- Figure out how to proceed --- *
 191    *
 192    * If this address already belongs to a different peer, then swap the
 193    * addresses over.  This doesn't leave the displaced peer in an especially
 194    * good state, but it ought to get sorted out soon enough.
 195    */
 196
 197   pa = am_find(&byaddr, a, sizeof(peer_byaddr), &f);
 198   if (f && pa->p == p)
 199     return (+1);
 200   else if (!f) {
 201     T( trace(T_PEER, "peer: updating address for `%s'", p_name(p)); )
 202     am_remove(&byaddr, p->byaddr);
 203     p->byaddr = pa; p->spec.sa = *a; pa->p = p;
 204     p->afix = afix(p->spec.sa.sa.sa_family); assert(p->afix >= 0);
 205     a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END);
 206     return (0);
 207   } else {
 208     q = pa->p; qa = p->byaddr;
 209     T( trace(T_PEER, "peer: swapping addresses for `%s' and `%s'",
 210              p_name(p), p_name(q)); )
 211     q->byaddr = qa; qa->p = q; q->spec.sa = p->spec.sa;
 212     p->byaddr = pa; pa->p = p; p->spec.sa = *a;
 213     ix = p->afix; p->afix = q->afix; q->afix = ix;
 214     a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END);
 215     a_notify("NEWADDR", "?PEER", q, "?ADDR", &q->spec.sa, A_END);
 216     return (0);
 217   }
 218 }
 219
 220 /* --- @p_decrypt@ --- *
 221  *
 222  * Arguments:   @peer **pp@ = pointer to peer to decrypt message from
 223  *              @addr *a@ = address the packet arrived on
 224  *              @size_t n@ = size of original incoming packet
 225  *              @int ty@ = message type to expect
 226  *              @buf *bin, *bout@ = input and output buffers
 227  *
 228  * Returns:     Zero on success; nonzero on error.
 229  *
 230  * Use:         Convenience function for packet decryption.  Reports errors
 231  *              and updates statistics appropriately.
 232  *
 233  *              If @*pp@ is null on entry and there are mobile peers then we
 234  *              see if any of them can decrypt the packet.  If so, we record
 235  *              @*a@ as the peer's new address and send a notification.
 236  */
 237
 238 static int p_decrypt(peer **pp, addr *a, size_t n,
 239                      int ty, buf *bin, buf *bout)
 240 {
 241   peer *p, *q;
 242   int err = KSERR_DECRYPT;
 243
 244   /* --- If we have a match on the source address then try that first --- */
 245
 246   q = *pp;
 247   if (q) {
 248     T( trace(T_PEER, "peer: decrypting packet from known peer `%s'",
 249              p_name(q)); )
 250     if ((err = ksl_decrypt(&q->ks, ty, bin, bout)) != KSERR_DECRYPT ||
 251         !(q->spec.f & PSF_MOBILE) || nmobile == 1) {
 252       p = q;
 253       goto match;
 254     }
 255     T( trace(T_PEER, "peer: failed to decrypt: try other mobile peers..."); )
 256   } else if (nmobile)
 257     T( trace(T_PEER, "peer: unknown source: trying mobile peers...") );
 258   else {
 259     p = 0;
 260     goto searched;
 261   }
 262
 263   /* --- See whether any mobile peer is interested --- */
 264
 265   p = 0;
 266   FOREACH_PEER(qq, {
 267     if (qq == q || !(qq->spec.f & PSF_MOBILE)) continue;
 268     if ((err = ksl_decrypt(&qq->ks, ty, bin, bout)) == KSERR_DECRYPT) {
 269       T( trace(T_PEER, "peer: peer `%s' failed to decrypt",
 270                p_name(qq)); )
 271         continue;
 272     } else {
 273       p = qq;
 274       IF_TRACING(T_PEER, {
 275         if (!err)
 276           trace(T_PEER, "peer: peer `%s' reports success", p_name(qq));
 277         else {
 278           trace(T_PEER, "peer: peer `%s' reports decryption error %d",
 279                 p_name(qq), err);
 280         }
 281       })
 282       break;
 283     }
 284   });
 285
 286   /* --- We've searched the mobile peers --- */
 287
 288 searched:
 289   if (!p) {
 290     if (!q)
 291       a_warn("PEER", "-", "unexpected-source", "?ADDR", a, A_END);
 292     else {
 293       a_warn("PEER", "?PEER", p, "decrypt-failed",
 294              "error-code", "%d", err, A_END);
 295       p_rxupdstats(q, n);
 296     }
 297     return (-1);
 298   }
 299
 300   /* --- We found one that accepted, so update the peer's address --- */
 301
 302   if (!err) {
 303     *pp = p;
 304     p_updateaddr(p, a);
 305   }
 306
 307 match:
 308   p_rxupdstats(p, n);
 309   if (err) {
 310     if (p) p->st.n_reject++;
 311     a_warn("PEER", "?PEER", p, "decrypt-failed",
 312            "error-code", "%d", err, A_END);
 313     return (-1);
 314   }
 315   if (!BOK(bout))
 316     return (-1);
 317   return (0);
 318 }
 319
 320 /* --- @p_read@ --- *
 321  *
 322  * Arguments:   @int fd@ = file descriptor to read from
 323  *              @unsigned mode@ = what happened
 324  *              @void *v@ = an uninteresting pointer
 325  *
 326  * Returns:     ---
 327  *
 328  * Use:         Reads a packet from somewhere.
 329  */
 330
 331 static void p_read(int fd, unsigned mode, void *v)
 332 {
 333   peer *p = 0;
 334   addr a;
 335   socklen_t sz;
 336   ssize_t n;
 337   int ch;
 338   buf b, bb;
 339 #ifndef NTRACE
 340   int ix = -1;
 341   char name[NI_MAXHOST], svc[NI_MAXSERV];
 342 #endif
 343
 344   /* --- Read the data --- */
 345
 346   QUICKRAND;
 347   sz = sizeof(addr);
 348   n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
 349   if (n < 0) {
 350     a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END);
 351     return;
 352   }
 353   IF_TRACING(T_PEER, {
 354     ix = afix(a.sa.sa_family);
 355     getnameinfo(&a.sa, sz, name, sizeof(name), svc, sizeof(svc),
 356                 NI_NUMERICHOST | NI_NUMERICSERV);
 357   })
 358
 359   /* --- If the packet is a greeting, don't check peers --- */
 360
 361   if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) {
 362     IF_TRACING(T_PEER, {
 363       trace(T_PEER, "peer: greeting received from %s %s %s",
 364             aftab[ix].name, name, svc);
 365       trace_block(T_PACKET, "peer: greeting contents", buf_i, n);
 366     })
 367     buf_init(&b, buf_i, n);
 368     buf_getbyte(&b);
 369     if (c_check(&b) || BLEFT(&b)) {
 370       a_warn("PEER", "-", "invalid-greeting", A_END);
 371       return;
 372     }
 373     a_notify("GREET",
 374              "?B64", buf_i + 1, (size_t)(n - 1),
 375              "?ADDR", &a,
 376              A_END);
 377     return;
 378   }
 379
 380   /* --- Find the appropriate peer --- *
 381    *
 382    * At this stage, don't worry too much about whether we actually found it.
 383    */
 384
 385   p = p_findbyaddr(&a);
 386
 387   IF_TRACING(T_PEER, {
 388     if (p) {
 389       trace(T_PEER,
 390             "peer: packet received from `%s' from address %s %s %s",
 391             p_name(p), aftab[ix].name, name, svc);
 392     } else {
 393       trace(T_PEER, "peer: packet received from unknown address %s %s %s",
 394             aftab[ix].name, name, svc);
 395     }
 396     trace_block(T_PACKET, "peer: packet contents", buf_i, n);
 397   })
 398
 399   /* --- Pick the packet apart --- */
 400
 401   buf_init(&b, buf_i, n);
 402   if ((ch = buf_getbyte(&b)) < 0) {
 403     a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END);
 404     return;
 405   }
 406   switch (ch & MSG_CATMASK) {
 407     case MSG_PACKET:
 408       if (ch & MSG_TYPEMASK) {
 409         a_warn("PEER",
 410                "?PEER", p,
 411                "bad-packet",
 412                "unknown-type", "0x%02x", ch,
 413                A_END);
 414         if (p) p->st.n_reject++;
 415         return;
 416       }
 417       buf_init(&bb, buf_o, sizeof(buf_o));
 418       if (p_decrypt(&p, &a, n, MSG_PACKET, &b, &bb))
 419         return;
 420       if (BOK(&bb)) {
 421         p->st.n_ipin++;
 422         p->st.sz_ipin += BSZ(&b);
 423         p->t->ops->inject(p->t, &bb);
 424       } else {
 425         p->st.n_reject++;
 426         a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
 427       }
 428       break;
 429     case MSG_KEYEXCH:
 430       if (!p) goto unexp;
 431       p_rxupdstats(p, n);
 432       kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
 433       break;
 434     case MSG_MISC:
 435       switch (ch & MSG_TYPEMASK) {
 436         case MISC_NOP:
 437           if (!p) goto unexp;
 438           p_rxupdstats(p, n);
 439           T( trace(T_PEER, "peer: received NOP packet"); )
 440           break;
 441         case MISC_PING:
 442           if (!p) goto unexp;
 443           p_rxupdstats(p, n);
 444           buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b));
 445           p_txend(p);
 446           break;
 447         case MISC_PONG:
 448           if (!p) goto unexp;
 449           p_rxupdstats(p, n);
 450           p_ponged(p, MISC_PONG, &b);
 451           break;
 452         case MISC_EPING:
 453           buf_init(&bb, buf_t, sizeof(buf_t));
 454           if (p_decrypt(&p, &a, n, ch, &b, &bb))
 455             return;
 456           if (BOK(&bb)) {
 457             buf_flip(&bb);
 458             p_encrypt(p, MSG_MISC | MISC_EPONG, &bb,
 459                       p_txstart(p, MSG_MISC | MISC_EPONG));
 460             p_txend(p);
 461           }
 462           break;
 463         case MISC_EPONG:
 464           buf_init(&bb, buf_t, sizeof(buf_t));
 465           if (p_decrypt(&p, &a, n, ch, &b, &bb))
 466             return;
 467           if (BOK(&bb)) {
 468             buf_flip(&bb);
 469             p_ponged(p, MISC_EPONG, &bb);
 470           }
 471           break;
 472       }
 473       break;
 474     default:
 475       if (p) p->st.n_reject++;
 476       a_warn("PEER",
 477              "?PEER", p,
 478              "bad-packet",
 479              "unknown-category", "0x%02x", ch,
 480              A_END);
 481       break;
 482     unexp:
 483       a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END);
 484       break;
 485   }
 486 }
 487
 488 /* --- @p_txstart@ --- *
 489  *
 490  * Arguments:   @peer *p@ = pointer to peer block
 491  *              @unsigned msg@ = message type code
 492  *
 493  * Returns:     A pointer to a buffer to write to.
 494  *
 495  * Use:         Starts sending to a peer.  Only one send can happen at a
 496  *              time.
 497  */
 498
 499 buf *p_txstart(peer *p, unsigned msg)
 500 {
 501   buf_init(&p->b, buf_o, sizeof(buf_o));
 502   buf_putbyte(&p->b, msg);
 503   return (&p->b);
 504 }
 505
 506 /* --- @p_txend@ --- *
 507  *
 508  * Arguments:   @peer *p@ = pointer to peer block
 509  *
 510  * Returns:     ---
 511  *
 512  * Use:         Sends a packet to the peer.
 513  */
 514
 515 static void p_setkatimer(peer *);
 516
 517 static int p_dotxend(peer *p)
 518 {
 519   socklen_t sasz = addrsz(&p->spec.sa);
 520
 521   if (!BOK(&p->b)) {
 522     a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
 523     return (0);
 524   }
 525   IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
 526                                  BBASE(&p->b), BLEN(&p->b)); )
 527   if (sendto(udpsock[p->afix].fd, BBASE(&p->b), BLEN(&p->b),
 528              0, &p->spec.sa.sa, sasz) < 0) {
 529     a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END);
 530     return (0);
 531   } else {
 532     p->st.n_out++;
 533     p->st.sz_out += BLEN(&p->b);
 534     return (1);
 535   }
 536 }
 537
 538 void p_txend(peer *p)
 539 {
 540   if (p_dotxend(p) && p->spec.t_ka) {
 541     sel_rmtimer(&p->tka);
 542     p_setkatimer(p);
 543   }
 544 }
 545
 546 /* --- @p_pingwrite@ --- *
 547  *
 548  * Arguments:   @ping *p@ = ping structure
 549  *              @buf *b@ = buffer to write in
 550  *
 551  * Returns:     ---
 552  *
 553  * Use:         Fills in a ping structure and writes the packet payload.
 554  */
 555
 556 static void p_pingwrite(ping *p, buf *b)
 557 {
 558   static uint32 seq = 0;
 559
 560   p->id = U32(seq++);
 561   GR_FILL(&rand_global, p->magic, sizeof(p->magic));
 562   buf_putu32(b, p->id);
 563   buf_put(b, p->magic, sizeof(p->magic));
 564 }
 565
 566 /* --- @p_pingdone@ --- *
 567  *
 568  * Arguments:   @ping *p@ = ping structure
 569  *              @int rc@ = return code to pass on
 570  *
 571  * Returns:     ---
 572  *
 573  * Use:         Disposes of a ping structure, maybe sending a notification.
 574  */
 575
 576 void p_pingdone(ping *p, int rc)
 577 {
 578   if (p->prev) p->prev->next = p->next;
 579   else p->p->pings = p->next;
 580   if (p->next) p->next->prev = p->prev;
 581   if (rc != PING_TIMEOUT) sel_rmtimer(&p->t);
 582   T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)",
 583            (unsigned long)p->id, rc); )
 584   if (rc >= 0) p->func(rc, p->arg);
 585 }
 586
 587 /* --- @p_pingtimeout@ --- *
 588  *
 589  * Arguments:   @struct timeval *now@ = the time now
 590  *              @void *pv@ = pointer to ping block
 591  *
 592  * Returns:     ---
 593  *
 594  * Use:         Called when a ping times out.
 595  */
 596
 597 static void p_pingtimeout(struct timeval *now, void *pv)
 598 {
 599   ping *p = pv;
 600
 601   T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); )
 602   p_pingdone(p, PING_TIMEOUT);
 603 }
 604
 605 /* --- @p_pingsend@ --- *
 606  *
 607  * Arguments:   @peer *p@ = destination peer
 608  *              @ping *pg@ = structure to fill in
 609  *              @unsigned type@ = message type
 610  *              @unsigned long timeout@ = how long to wait before giving up
 611  *              @void (*func)(int, void *)@ = callback function
 612  *              @void *arg@ = argument for callback
 613  *
 614  * Returns:     Zero if successful, nonzero if it failed.
 615  *
 616  * Use:         Sends a ping to a peer.  Call @func@ with a nonzero argument
 617  *              if we get an answer within the timeout, or zero if no answer.
 618  */
 619
 620 int p_pingsend(peer *p, ping *pg, unsigned type,
 621                unsigned long timeout,
 622                void (*func)(int, void *), void *arg)
 623 {
 624   buf *b, bb;
 625   struct timeval tv;
 626
 627   switch (type) {
 628     case MISC_PING:
 629       pg->msg = MISC_PONG;
 630       b = p_txstart(p, MSG_MISC | MISC_PING);
 631       p_pingwrite(pg, b);
 632       p_txend(p);
 633       break;
 634     case MISC_EPING:
 635       pg->msg = MISC_EPONG;
 636       b = p_txstart(p, MSG_MISC | MISC_EPING);
 637       buf_init(&bb, buf_t, sizeof(buf_t));
 638       p_pingwrite(pg, &bb);
 639       buf_flip(&bb);
 640       p_encrypt(p, MSG_MISC | MISC_EPING, &bb, b);
 641       if (!BOK(b))
 642         return (-1);
 643       p_txend(p);
 644       break;
 645     default:
 646       abort();
 647       break;
 648   }
 649
 650   pg->next = p->pings;
 651   pg->prev = 0;
 652   pg->p = p;
 653   pg->func = func;
 654   pg->arg = arg;
 655   if (p->pings) p->pings->prev = pg;
 656   p->pings = pg;
 657   gettimeofday(&tv, 0);
 658   tv.tv_sec += timeout;
 659   sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg);
 660   T( trace(T_PEER, "peer: send %s 0x%08lx to %s",
 661            p_pingtype(type), (unsigned long)pg->id, p->spec.name); )
 662   return (0);
 663 }
 664
 665 /* --- @p_greet@ --- *
 666  *
 667  * Arguments:   @peer *p@ = peer to send to
 668  *              @const void *c@ = pointer to challenge
 669  *              @size_t sz@ = size of challenge
 670  *
 671  * Returns:     ---
 672  *
 673  * Use:         Sends a greeting packet.
 674  */
 675
 676 void p_greet(peer *p, const void *c, size_t sz)
 677 {
 678   buf *b = p_txstart(p, MSG_MISC | MISC_GREET);
 679   buf_put(b, c, sz);
 680   p_txend(p);
 681 }
 682
 683 /* --- @p_tun@ --- *
 684  *
 685  * Arguments:   @peer *p@ = pointer to peer block
 686  *              @buf *b@ = buffer containing incoming packet
 687  *
 688  * Returns:     ---
 689  *
 690  * Use:         Handles a packet which needs to be sent to a peer.
 691  */
 692
 693 void p_tun(peer *p, buf *b)
 694 {
 695   buf *bb = p_txstart(p, MSG_PACKET);
 696
 697   QUICKRAND;
 698   p_encrypt(p, MSG_PACKET, b, bb);
 699   if (BOK(bb) && BLEN(bb)) {
 700     p->st.n_ipout++;
 701     p->st.sz_ipout += BLEN(bb);
 702     p_txend(p);
 703   }
 704 }
 705
 706 /* --- @p_keyreload@ --- *
 707  *
 708  * Arguments:   ---
 709  *
 710  * Returns:     ---
 711  *
 712  * Use:         Forces a check of the daemon's keyring files.
 713  */
 714
 715 void p_keyreload(void)
 716 {
 717   if (km_reload())
 718     FOREACH_PEER(p, { kx_newkeys(&p->kx); });
 719 }
 720
 721 /* --- @p_interval@ --- *
 722  *
 723  * Arguments:   ---
 724  *
 725  * Returns:     ---
 726  *
 727  * Use:         Called periodically to do tidying.
 728  */
 729
 730 void p_interval(void)
 731 {
 732   p_keyreload();
 733   FOREACH_PEER(p, { ksl_prune(&p->ks); });
 734 }
 735
 736 /* --- @p_stats@ --- *
 737  *
 738  * Arguments:   @peer *p@ = pointer to a peer block
 739  *
 740  * Returns:     A pointer to the peer's statistics.
 741  */
 742
 743 stats *p_stats(peer *p) { return (&p->st); }
 744
 745 /* --- @p_ifname@ --- *
 746  *
 747  * Arguments:   @peer *p@ = pointer to a peer block
 748  *
 749  * Returns:     A pointer to the peer's interface name.
 750  */
 751
 752 const char *p_ifname(peer *p) { return (p->ifname); }
 753
 754 /* --- @p_setifname@ --- *
 755  *
 756  * Arguments:   @peer *p@ = pointer to a peer block
 757  *              @const char *name@ = pointer to the new name
 758  *
 759  * Returns:     ---
 760  *
 761  * Use:         Changes the name held for a peer's interface.
 762  */
 763
 764 void p_setifname(peer *p, const char *name)
 765 {
 766   xfree(p->ifname);
 767   p->ifname = xstrdup(name);
 768   if (p->spec.tops->setifname)
 769     p->spec.tops->setifname(p->t, name);
 770 }
 771
 772 /* --- @p_addr@ --- *
 773  *
 774  * Arguments:   @peer *p@ = pointer to a peer block
 775  *
 776  * Returns:     A pointer to the peer's address.
 777  */
 778
 779 const addr *p_addr(peer *p) { return (&p->spec.sa); }
 780
 781 /* --- @p_init@ --- *
 782  *
 783  * Arguments:   @struct addrinfo *ailist@ = addresses to bind to
 784  *
 785  * Returns:     ---
 786  *
 787  * Use:         Initializes the peer system; creates the socket.
 788  */
 789
 790 void p_init(struct addrinfo *ailist)
 791 {
 792   int fd;
 793   int len = PKBUFSZ;
 794   int i;
 795   struct addrinfo *ai;
 796   unsigned port, lastport = 0;
 797   addr a;
 798   socklen_t sz;
 799
 800   for (i = 0; i < NADDRFAM; i++) udpsock[i].fd = -1;
 801
 802   for (ai = ailist; ai; ai = ai->ai_next) {
 803     if ((i = afix(ai->ai_family)) < 0) continue;
 804     if (udpsock[i].fd != -1) continue;
 805
 806     /* --- Note on socket buffer sizes --- *
 807      *
 808      * For some bizarre reason, Linux 2.2 (at least) doubles the socket
 809      * buffer sizes I pass to @setsockopt@.  I'm not putting special-case
 810      * code here for Linux: BSD (at least TCPv2) does what I tell it rather
 811      * than second-guessing me.
 812      */
 813
 814     if ((fd = socket(ai->ai_family, SOCK_DGRAM, 0)) < 0)
 815       die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
 816     assert(ai->ai_addrlen <= sizeof(a));
 817     memcpy(&a, ai->ai_addr, ai->ai_addrlen);
 818     if ((port = getport(&a)) == 0 && lastport) setport(&a, lastport);
 819     if (bind(fd, &a.sa, addrsz(&a)))
 820       die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
 821     if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
 822         setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
 823       die(EXIT_FAILURE, "failed to set socket buffer sizes: %s",
 824           strerror(errno));
 825     }
 826     fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 827     sel_initfile(&sel, &udpsock[i], fd, SEL_READ, p_read, 0);
 828     sel_addfile(&udpsock[i]);
 829     T( trace(T_PEER, "peer: created %s socket", aftab[i].name); )
 830     if (!port) {
 831       sz = sizeof(a);
 832       if (getsockname(fd, &a.sa, &sz)) {
 833         die(EXIT_FAILURE, "failed to read local socket address: %s",
 834             strerror(errno));
 835       }
 836       lastport = getport(&a);
 837     }
 838   }
 839
 840   sym_create(&byname);
 841   am_create(&byaddr);
 842 }
 843
 844 /* --- @p_port@ --- *
 845  *
 846  * Arguments:   @int i@ = address family index to retrieve
 847  *
 848  * Returns:     Port number used for socket.
 849  */
 850
 851 unsigned p_port(int i)
 852 {
 853   addr a;
 854   socklen_t sz = sizeof(addr);
 855
 856   if (getsockname(udpsock[i].fd, &a.sa, &sz))
 857     die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
 858   return (getport(&a));
 859 }
 860
 861 /* --- @p_keepalive@ --- *
 862  *
 863  * Arguments:   @struct timeval *now@ = the current time
 864  *              @void *pv@ = peer to wake up
 865  *
 866  * Returns:     ---
 867  *
 868  * Use:         Sends a keepalive ping message to its peer.
 869  */
 870
 871 static void p_keepalive(struct timeval *now, void *pv)
 872 {
 873   peer *p = pv;
 874
 875   p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p);
 876   T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); )
 877   p_setkatimer(p);
 878 }
 879
 880 /* --- @p_setkatimer@ --- *
 881  *
 882  * Arguments:   @peer *p@ = peer to set
 883  *
 884  * Returns:     ---
 885  *
 886  * Use:         Resets the keepalive timer thing.
 887  */
 888
 889 static void p_setkatimer(peer *p)
 890 {
 891   struct timeval tv;
 892
 893   if (!p->spec.t_ka)
 894     return;
 895   gettimeofday(&tv, 0);
 896   tv.tv_sec += p->spec.t_ka;
 897   sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p);
 898 }
 899
 900 /* --- @p_create@ --- *
 901  *
 902  * Arguments:   @peerspec *spec@ = information about this peer
 903  *
 904  * Returns:     Pointer to the peer block, or null if it failed.
 905  *
 906  * Use:         Creates a new named peer block.  No peer is actually attached
 907  *              by this point.
 908  */
 909
 910 peer *p_create(peerspec *spec)
 911 {
 912   peer *p = CREATE(peer);
 913   const tunnel_ops *tops = spec->tops;
 914   int fd;
 915   unsigned f;
 916
 917   p->byname = sym_find(&byname, spec->name, -1, sizeof(peer_byname), &f);
 918   if (f) goto tidy_0;
 919   p->byaddr = am_find(&byaddr, &spec->sa, sizeof(peer_byaddr), &f);
 920   if (f) goto tidy_1;
 921   p->byname->p = p->byaddr->p = p;
 922
 923   T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); )
 924   p->spec = *spec;
 925   p->spec.name = (/*unconst*/ char *)SYM_NAME(p->byname);
 926   if (spec->tag) p->spec.tag = xstrdup(spec->tag);
 927   if (spec->privtag) p->spec.privtag = xstrdup(spec->privtag);
 928   p->ks = 0;
 929   p->pings = 0;
 930   p->ifname = 0;
 931   p->afix = afix(p->spec.sa.sa.sa_family); assert(p->afix >= 0);
 932   memset(&p->st, 0, sizeof(stats));
 933   p->st.t_start = time(0);
 934   if (!(tops->flags & TUNF_PRIVOPEN))
 935     fd = -1;
 936   else if ((fd = ps_tunfd(tops, &p->ifname)) < 0)
 937     goto tidy_2;
 938   if ((p->t = tops->create(p, fd, &p->ifname)) == 0)
 939     goto tidy_3;
 940   T( trace(T_TUNNEL, "peer: attached interface %s to peer `%s'",
 941            p->ifname, p_name(p)); )
 942   p_setkatimer(p);
 943   if (kx_init(&p->kx, p, &p->ks, p->spec.f & PSF_KXMASK))
 944     goto tidy_4;
 945   a_notify("ADD",
 946            "?PEER", p,
 947            "%s", p->ifname,
 948            "?ADDR", &p->spec.sa,
 949            A_END);
 950   if (!(p->spec.f & KXF_CORK)) {
 951     a_notify("KXSTART", "?PEER", p, A_END);
 952     /* Couldn't tell anyone before */
 953   }
 954   if (p->spec.f & PSF_MOBILE) nmobile++;
 955   return (p);
 956
 957 tidy_4:
 958   if (spec->t_ka) sel_rmtimer(&p->tka);
 959   xfree(p->ifname);
 960   p->t->ops->destroy(p->t);
 961 tidy_3:
 962   if (fd >= 0) close(fd);
 963 tidy_2:
 964   am_remove(&byaddr, p->byaddr);
 965   if (p->spec.tag) xfree(p->spec.tag);
 966   if (p->spec.privtag) xfree(p->spec.privtag);
 967 tidy_1:
 968   sym_remove(&byname, p->byname);
 969 tidy_0:
 970   DESTROY(p);
 971   return (0);
 972 }
 973
 974 /* --- @p_name@ --- *
 975  *
 976  * Arguments:   @peer *p@ = pointer to a peer block
 977  *
 978  * Returns:     A pointer to the peer's name.
 979  */
 980
 981 const char *p_name(peer *p)
 982   { if (p) return (p->spec.name); else return ("-"); }
 983
 984 /* --- @p_tag@ --- *
 985  *
 986  * Arguments:   @peer *p@ = pointer to a peer block
 987  *
 988  * Returns:     A pointer to the peer's public key tag.
 989  */
 990
 991 const char *p_tag(peer *p)
 992   { return (p->spec.tag ? p->spec.tag : p->spec.name); }
 993
 994 /* --- @p_privtag@ --- *
 995  *
 996  * Arguments:   @peer *p@ = pointer to a peer block
 997  *
 998  * Returns:     A pointer to the peer's private key tag.
 999  */
1000
1001 const char *p_privtag(peer *p)
1002   { return (p->spec.privtag ? p->spec.privtag : tag_priv); }
1003
1004 /* --- @p_spec@ --- *
1005  *
1006  * Arguments:   @peer *p@ = pointer to a peer block
1007  *
1008  * Returns:     Pointer to the peer's specification
1009  */
1010
1011 const peerspec *p_spec(peer *p) { return (&p->spec); }
1012
1013 /* --- @p_findbyaddr@ --- *
1014  *
1015  * Arguments:   @const addr *a@ = address to look up
1016  *
1017  * Returns:     Pointer to the peer block, or null if not found.
1018  *
1019  * Use:         Finds a peer by address.
1020  */
1021
1022 peer *p_findbyaddr(const addr *a)
1023 {
1024   peer_byaddr *pa;
1025
1026   if ((pa = am_find(&byaddr, a, 0, 0)) != 0) {
1027     assert(pa->p);
1028     return (pa->p);
1029   }
1030   return (0);
1031 }
1032
1033 /* --- @p_find@ --- *
1034  *
1035  * Arguments:   @const char *name@ = name to look up
1036  *
1037  * Returns:     Pointer to the peer block, or null if not found.
1038  *
1039  * Use:         Finds a peer by name.
1040  */
1041
1042 peer *p_find(const char *name)
1043 {
1044   peer_byname *pn;
1045
1046   if ((pn = sym_find(&byname, name, -1, 0, 0)) != 0)
1047     return (pn->p);
1048   return (0);
1049 }
1050
1051 /* --- @p_destroy@ --- *
1052  *
1053  * Arguments:   @peer *p@ = pointer to a peer
1054  *
1055  * Returns:     ---
1056  *
1057  * Use:         Destroys a peer.
1058  */
1059
1060 void p_destroy(peer *p)
1061 {
1062   ping *pg, *ppg;
1063
1064   T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); )
1065   a_notify("KILL", "%s", p->spec.name, A_END);
1066   ksl_free(&p->ks);
1067   kx_free(&p->kx);
1068   if (p->spec.f & PSF_MOBILE) nmobile--;
1069   if (p->ifname) xfree(p->ifname);
1070   if (p->spec.tag) xfree(p->spec.tag);
1071   if (p->spec.privtag) xfree(p->spec.privtag);
1072   p->t->ops->destroy(p->t);
1073   if (p->spec.t_ka) sel_rmtimer(&p->tka);
1074   for (pg = p->pings; pg; pg = ppg) {
1075     ppg = pg->next;
1076     p_pingdone(pg, PING_PEERDIED);
1077   }
1078   sym_remove(&byname, p->byname);
1079   am_remove(&byaddr, p->byaddr);
1080   DESTROY(p);
1081 }
1082
1083 /* --- @p_mkiter@ --- *
1084  *
1085  * Arguments:   @peer_iter *i@ = pointer to an iterator
1086  *
1087  * Returns:     ---
1088  *
1089  * Use:         Initializes the iterator.
1090  */
1091
1092 void p_mkiter(peer_iter *i) { sym_mkiter(&i->i, &byname); }
1093
1094 /* --- @p_next@ --- *
1095  *
1096  * Arguments:   @peer_iter *i@ = pointer to an iterator
1097  *
1098  * Returns:     Next peer, or null if at the end.
1099  *
1100  * Use:         Returns the next peer.
1101  */
1102
1103 peer *p_next(peer_iter *i)
1104 {
1105   peer_byname *pn;
1106
1107   if ((pn = sym_next(&i->i)) == 0)
1108     return (0);
1109   return (pn->p);
1110 }
1111
1112 /*----- That's all, folks -------------------------------------------------*/