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