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