5 * Communication with the peer
7 * (c) 2001 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Trivial IP Encryption (TrIPE).
14 * TrIPE is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * TrIPE is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with TrIPE; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Header files ------------------------------------------------------*/
33 /*----- Static variables --------------------------------------------------*/
35 static peer *peers = 0;
38 /*----- Tunnel table ------------------------------------------------------*/
40 const tunnel_ops *tunnels[] = {
54 /*----- Main code ---------------------------------------------------------*/
56 static void checktimers(void)
62 assert((*tt)->prev == tt);
67 /* --- @p_pingtype@ --- *
69 * Arguments: @unsigned msg@ = message type
71 * Returns: String to describe the message.
74 static const char *p_pingtype(unsigned msg)
76 switch (msg & MSG_TYPEMASK) {
79 return "transport-ping";
82 return "encrypted-ping";
88 /* --- @p_ponged@ --- *
90 * Arguments: @peer *p@ = peer packet arrived from
91 * @unsigned msg@ = message type
92 * @buf *b@ = buffer containing payload
96 * Use: Processes a ping response.
99 static void p_ponged(peer *p, unsigned msg, buf *b)
106 trace(T_PEER, "peer: received %s reply from %s",
107 p_pingtype(msg), p->spec.name);
108 trace_block(T_PACKET, "peer: ping contents", BBASE(b), BSZ(b));
111 if (buf_getu32(b, &id) ||
112 (magic = buf_get(b, sizeof(pg->magic))) == 0 ||
114 a_warn("PEER %s malformed-%s", p->spec.name, p_pingtype(msg));
118 for (pg = p->pings; pg; pg = pg->next) {
122 a_warn("PEER %s unexpected-%s 0x%08lx",
123 p->spec.name, p_pingtype(msg), (unsigned long)id);
127 if (memcmp(magic, pg->magic, sizeof(pg->magic)) != 0) {
128 a_warn("PEER %s corrupt-%s", p->spec.name, p_pingtype(msg));
131 p_pingdone(pg, PING_OK);
134 /* --- @p_read@ --- *
136 * Arguments: @int fd@ = file descriptor to read from
137 * @unsigned mode@ = what happened
138 * @void *v@ = an uninteresting pointer
142 * Use: Reads a packet from somewhere.
145 static void p_read(int fd, unsigned mode, void *v)
154 /* --- Read the data --- */
158 n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
160 a_warn("PEER - socket-read-error -- %s", strerror(errno));
164 /* --- Find the appropriate peer --- */
166 assert(a.sa.sa_family == AF_INET);
167 for (p = peers; p; p = p->next) {
168 if (p->spec.sa.sin.sin_addr.s_addr == a.sin.sin_addr.s_addr &&
169 p->spec.sa.sin.sin_port == a.sin.sin_port)
172 a_warn("PEER - unexpected-source INET %s %u",
173 inet_ntoa(a.sin.sin_addr), (unsigned)ntohs(a.sin.sin_port));
178 trace(T_PEER, "peer: packet received from `%s'", p->spec.name);
179 trace_block(T_PACKET, "peer: packet contents", buf_i, n);
182 /* --- Pick the packet apart --- */
184 p->st.t_last = time(0);
187 buf_init(&b, buf_i, n);
188 if ((ch = buf_getbyte(&b)) < 0) {
189 a_warn("PEER %s bad-packet no-type", p->spec.name);
192 switch (ch & MSG_CATMASK) {
194 if (ch & MSG_TYPEMASK) {
195 a_warn("PEER %s bad-packet unknown-type 0x%02x", p->spec.name, ch);
199 buf_init(&bb, buf_o, sizeof(buf_o));
200 if (ksl_decrypt(&p->ks, MSG_PACKET, &b, &bb)) {
202 a_warn("PEER %s decrypt-failed", p->spec.name);
207 p->st.sz_ipin += BSZ(&b);
208 p->t->ops->inject(p->t, &bb);
211 a_warn("PEER %s packet-build-failed", p->spec.name);
215 kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
218 switch (ch & MSG_TYPEMASK) {
220 T( trace(T_PEER, "peer: received NOP packet"); )
223 buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b));
227 p_ponged(p, MISC_PONG, &b);
230 buf_init(&bb, buf_t, sizeof(buf_t));
231 if (ksl_decrypt(&p->ks, ch, &b, &bb)) {
233 a_warn("PEER %s decrypt-failed", p->spec.name);
238 if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPONG, &bb,
239 p_txstart(p, MSG_MISC | MISC_EPONG)))
245 buf_init(&bb, buf_t, sizeof(buf_t));
246 if (ksl_decrypt(&p->ks, ch, &b, &bb)) {
248 a_warn("PEER %s decrypt-failed", p->spec.name);
253 p_ponged(p, MISC_EPONG, &bb);
260 a_warn("PEER %s bad-packet unknown-category 0x%02x", p->spec.name, ch);
265 /* --- @p_txstart@ --- *
267 * Arguments: @peer *p@ = pointer to peer block
268 * @unsigned msg@ = message type code
270 * Returns: A pointer to a buffer to write to.
272 * Use: Starts sending to a peer. Only one send can happen at a
276 buf *p_txstart(peer *p, unsigned msg)
278 buf_init(&p->b, buf_o, sizeof(buf_o));
279 buf_putbyte(&p->b, msg);
283 /* --- @p_txend@ --- *
285 * Arguments: @peer *p@ = pointer to peer block
289 * Use: Sends a packet to the peer.
292 static void p_setkatimer(peer *);
294 static int p_dotxend(peer *p)
297 a_warn("PEER %s packet-build-failed", p->spec.name);
300 IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
301 BBASE(&p->b), BLEN(&p->b)); )
302 if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b),
303 0, &p->spec.sa.sa, p->spec.sasz) < 0) {
304 a_warn("PEER %s socket-write-error -- %s",
305 p->spec.name, strerror(errno));
309 p->st.sz_out += BLEN(&p->b);
314 void p_txend(peer *p)
316 if (p_dotxend(p) && p->spec.t_ka) {
317 sel_rmtimer(&p->tka);
322 /* --- @p_pingwrite@ --- *
324 * Arguments: @ping *p@ = ping structure
325 * @buf *b@ = buffer to write in
329 * Use: Fills in a ping structure and writes the packet payload.
332 static void p_pingwrite(ping *p, buf *b)
334 static uint32 seq = 0;
337 GR_FILL(&rand_global, p->magic, sizeof(p->magic));
338 buf_putu32(b, p->id);
339 buf_put(b, p->magic, sizeof(p->magic));
342 /* --- @p_pingdone@ --- *
344 * Arguments: @ping *p@ = ping structure
345 * @int rc@ = return code to pass on
349 * Use: Disposes of a ping structure, maybe sending a notification.
352 void p_pingdone(ping *p, int rc)
354 if (p->prev) p->prev->next = p->next;
355 else p->p->pings = p->next;
356 if (p->next) p->next->prev = p->prev;
357 if (rc != PING_TIMEOUT) sel_rmtimer(&p->t);
358 T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)",
359 (unsigned long)p->id, rc); )
361 if (rc >= 0) p->func(rc, p->arg);
364 /* --- @p_pingtimeout@ --- *
366 * Arguments: @struct timeval *now@ = the time now
367 * @void *pv@ = pointer to ping block
371 * Use: Called when a ping times out.
374 static void p_pingtimeout(struct timeval *now, void *pv)
378 T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); )
379 p_pingdone(p, PING_TIMEOUT);
382 /* --- @p_pingsend@ --- *
384 * Arguments: @peer *p@ = destination peer
385 * @ping *pg@ = structure to fill in
386 * @unsigned type@ = message type
387 * @unsigned long timeout@ = how long to wait before giving up
388 * @void (*func)(int, void *)@ = callback function
389 * @void *arg@ = argument for callback
391 * Returns: Zero if successful, nonzero if it failed.
393 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
394 * if we get an answer within the timeout, or zero if no answer.
397 int p_pingsend(peer *p, ping *pg, unsigned type,
398 unsigned long timeout,
399 void (*func)(int, void *), void *arg)
407 b = p_txstart(p, MSG_MISC | MISC_PING);
412 pg->msg = MISC_EPONG;
413 b = p_txstart(p, MSG_MISC | MISC_EPING);
414 buf_init(&bb, buf_t, sizeof(buf_t));
415 p_pingwrite(pg, &bb);
417 if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPING, &bb, b))
433 if (p->pings) p->pings->prev = pg;
435 gettimeofday(&tv, 0);
436 tv.tv_sec += timeout;
437 sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg);
439 T( trace(T_PEER, "peer: send %s 0x%08lx to %s",
440 p_pingtype(type), (unsigned long)pg->id, p->spec.name); )
446 * Arguments: @peer *p@ = pointer to peer block
447 * @buf *b@ = buffer containing incoming packet
451 * Use: Handles a packet which needs to be sent to a peer.
454 void p_tun(peer *p, buf *b)
456 buf *bb = p_txstart(p, MSG_PACKET);
459 if (ksl_encrypt(&p->ks, MSG_PACKET, b, bb))
461 if (BOK(bb) && BLEN(bb)) {
463 p->st.sz_ipout += BLEN(bb);
468 /* --- @p_keyreload@ --- *
474 * Use: Forces a check of the daemon's keyring files.
477 void p_keyreload(void)
482 for (p = peers; p; p = p->next)
487 /* --- @p_interval@ --- *
493 * Use: Called periodically to do tidying.
496 void p_interval(void)
501 for (p = peers; p; p = p->next)
505 /* --- @p_stats@ --- *
507 * Arguments: @peer *p@ = pointer to a peer block
509 * Returns: A pointer to the peer's statistics.
512 stats *p_stats(peer *p) { return (&p->st); }
514 /* --- @p_ifname@ --- *
516 * Arguments: @peer *p@ = pointer to a peer block
518 * Returns: A pointer to the peer's interface name.
521 const char *p_ifname(peer *p) { return (p->t->ops->ifname(p->t)); }
523 /* --- @p_addr@ --- *
525 * Arguments: @peer *p@ = pointer to a peer block
527 * Returns: A pointer to the peer's address.
530 const addr *p_addr(peer *p) { return (&p->spec.sa); }
532 /* --- @p_init@ --- *
534 * Arguments: @struct in_addr addr@ = address to bind to
535 * @unsigned port@ = port number to listen to
539 * Use: Initializes the peer system; creates the socket.
542 void p_init(struct in_addr addr, unsigned port)
545 struct sockaddr_in sin;
548 /* --- Note on socket buffer sizes --- *
550 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
551 * sizes I pass to @setsockopt@. I'm not putting special-case code here
552 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
556 if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
557 die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
559 sin.sin_family = AF_INET;
561 sin.sin_port = htons(port);
562 if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
563 die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
564 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
565 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
566 die(EXIT_FAILURE, "failed to set socket buffer sizes: %s",
569 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
570 sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0);
572 T( trace(T_PEER, "peer: created socket"); )
575 /* --- @p_port@ --- *
579 * Returns: Port number used for socket.
582 unsigned p_port(void)
585 size_t sz = sizeof(addr);
587 if (getsockname(sock.fd, &a.sa, &sz))
588 die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
589 assert(a.sa.sa_family == AF_INET);
590 return (ntohs(a.sin.sin_port));
593 /* --- @p_keepalive@ --- *
595 * Arguments: @struct timeval *now@ = the current time
596 * @void *pv@ = peer to wake up
600 * Use: Sends a keepalive ping message to its peer.
603 static void p_keepalive(struct timeval *now, void *pv)
606 p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p);
607 T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); )
611 /* --- @p_setkatimer@ --- *
613 * Arguments: @peer *p@ = peer to set
617 * Use: Resets the keepalive timer thing.
620 static void p_setkatimer(peer *p)
626 gettimeofday(&tv, 0);
627 tv.tv_sec += p->spec.t_ka;
628 sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p);
631 /* --- @p_create@ --- *
633 * Arguments: @peerspec *spec@ = information about this peer
635 * Returns: Pointer to the peer block, or null if it failed.
637 * Use: Creates a new named peer block. No peer is actually attached
641 peer *p_create(peerspec *spec)
643 peer *p = CREATE(peer);
645 T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); )
647 p->spec.name = xstrdup(spec->name);
651 memset(&p->st, 0, sizeof(stats));
652 p->st.t_start = time(0);
653 if ((p->t = spec->tops->create(p)) == 0)
656 if (kx_init(&p->kx, p, &p->ks))
662 switch (p->spec.sa.sa.sa_family) {
664 a_notify("ADD %s %s INET %s %u",
666 p->t->ops->ifname(p->t),
667 inet_ntoa(p->spec.sa.sin.sin_addr),
668 (unsigned)ntohs(p->spec.sa.sin.sin_port));
671 a_notify("ADD %s %s UNKNOWN", spec->name, p->t->ops->ifname(p->t));
674 a_notify("KXSTART %s", spec->name); /* Couldn't tell anyone before */
679 sel_rmtimer(&p->tka);
680 p->t->ops->destroy(p->t);
687 /* --- @p_name@ --- *
689 * Arguments: @peer *p@ = pointer to a peer block
691 * Returns: A pointer to the peer's name.
694 const char *p_name(peer *p) { return (p->spec.name); }
696 /* --- @p_spec@ --- *
698 * Arguments: @peer *p@ = pointer to a peer block
700 * Returns: Pointer to the peer's specification
703 const peerspec *p_spec(peer *p) { return (&p->spec); }
705 /* --- @p_find@ --- *
707 * Arguments: @const char *name@ = name to look up
709 * Returns: Pointer to the peer block, or null if not found.
711 * Use: Finds a peer by name.
714 peer *p_find(const char *name)
717 for (p = peers; p; p = p->next) {
718 if (strcmp(name, p->spec.name) == 0)
724 /* --- @p_destroy@ --- *
726 * Arguments: @peer *p@ = pointer to a peer
730 * Use: Destroys a peer.
733 void p_destroy(peer *p)
737 T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); )
738 a_notify("KILL %s", p->spec.name);
741 p->t->ops->destroy(p->t);
743 sel_rmtimer(&p->tka);
745 for (pg = p->pings; pg; pg = ppg) {
747 p_pingdone(pg, PING_PEERDIED);
750 p->next->prev = p->prev;
752 p->prev->next = p->next;
758 /* --- @p_first@, @p_next@ --- *
760 * Arguments: @peer *p@ = a peer block
762 * Returns: @peer_first@ returns the first peer in some ordering;
763 * @peer_next@ returns the peer following a given one in the
764 * same ordering. Null is returned for the end of the list.
767 peer *p_first(void) { return (peers); }
768 peer *p_next(peer *p) { return (p->next); }
770 /*----- That's all, folks -------------------------------------------------*/