3 * Communication with the peer
5 * (c) 2001 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Trivial IP Encryption (TrIPE).
12 * TrIPE is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * TrIPE is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 /*----- Header files ------------------------------------------------------*/
31 /*----- Static variables --------------------------------------------------*/
33 static sym_table byname;
34 static addrmap byaddr;
37 /*----- Tunnel table ------------------------------------------------------*/
39 const tunnel_ops *tunnels[] = {
53 /*----- Main code ---------------------------------------------------------*/
55 /* --- @p_pingtype@ --- *
57 * Arguments: @unsigned msg@ = message type
59 * Returns: String to describe the message.
62 static const char *p_pingtype(unsigned msg)
64 switch (msg & MSG_TYPEMASK) {
67 return "transport-ping";
70 return "encrypted-ping";
76 /* --- @p_ponged@ --- *
78 * Arguments: @peer *p@ = peer packet arrived from
79 * @unsigned msg@ = message type
80 * @buf *b@ = buffer containing payload
84 * Use: Processes a ping response.
87 static void p_ponged(peer *p, unsigned msg, buf *b)
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));
99 if (buf_getu32(b, &id) ||
100 (magic = buf_get(b, sizeof(pg->magic))) == 0 ||
102 a_warn("PEER", "?PEER", p, "malformed-%s", p_pingtype(msg), A_END);
106 for (pg = p->pings; pg; pg = pg->next) {
112 "unexpected-%s", p_pingtype(msg),
113 "0x%08lx", (unsigned long)id,
118 if (memcmp(magic, pg->magic, sizeof(pg->magic)) != 0) {
119 a_warn("PEER", "?PEER", p, "corrupt-%s", p_pingtype(msg), A_END);
122 p_pingdone(pg, PING_OK);
125 /* --- @p_read@ --- *
127 * Arguments: @int fd@ = file descriptor to read from
128 * @unsigned mode@ = what happened
129 * @void *v@ = an uninteresting pointer
133 * Use: Reads a packet from somewhere.
136 static void p_read(int fd, unsigned mode, void *v)
145 /* --- Read the data --- */
149 n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
151 a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END);
155 /* --- If the packet is a greeting, don't check peers --- */
157 if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) {
159 trace(T_PEER, "peer: greeting received from INET %s %u",
160 inet_ntoa(a.sin.sin_addr),
161 (unsigned)ntohs(a.sin.sin_port));
162 trace_block(T_PACKET, "peer: greeting contents", buf_i, n);
164 buf_init(&b, buf_i, n);
166 if (c_check(&b) || BLEFT(&b)) {
167 a_warn("PEER", "-", "invalid-greeting", A_END);
171 "?B64", buf_i + 1, (size_t)(n - 1),
177 /* --- Find the appropriate peer --- */
179 if ((p = p_findbyaddr(&a)) == 0) {
180 a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END);
185 trace(T_PEER, "peer: packet received from `%s'", p->spec.name);
186 trace_block(T_PACKET, "peer: packet contents", buf_i, n);
189 /* --- Pick the packet apart --- */
191 p->st.t_last = time(0);
194 buf_init(&b, buf_i, n);
195 if ((ch = buf_getbyte(&b)) < 0) {
196 a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END);
199 switch (ch & MSG_CATMASK) {
201 if (ch & MSG_TYPEMASK) {
205 "unknown-type", "0x%02x", ch,
210 buf_init(&bb, buf_o, sizeof(buf_o));
211 if (ksl_decrypt(&p->ks, MSG_PACKET, &b, &bb)) {
213 a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
218 p->st.sz_ipin += BSZ(&b);
219 p->t->ops->inject(p->t, &bb);
222 a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
226 kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
229 switch (ch & MSG_TYPEMASK) {
231 T( trace(T_PEER, "peer: received NOP packet"); )
234 buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b));
238 p_ponged(p, MISC_PONG, &b);
241 buf_init(&bb, buf_t, sizeof(buf_t));
242 if (ksl_decrypt(&p->ks, ch, &b, &bb)) {
244 a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
249 if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPONG, &bb,
250 p_txstart(p, MSG_MISC | MISC_EPONG)))
256 buf_init(&bb, buf_t, sizeof(buf_t));
257 if (ksl_decrypt(&p->ks, ch, &b, &bb)) {
259 a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
264 p_ponged(p, MISC_EPONG, &bb);
274 "unknown-category" "0x%02x", ch,
280 /* --- @p_txstart@ --- *
282 * Arguments: @peer *p@ = pointer to peer block
283 * @unsigned msg@ = message type code
285 * Returns: A pointer to a buffer to write to.
287 * Use: Starts sending to a peer. Only one send can happen at a
291 buf *p_txstart(peer *p, unsigned msg)
293 buf_init(&p->b, buf_o, sizeof(buf_o));
294 buf_putbyte(&p->b, msg);
298 /* --- @p_txend@ --- *
300 * Arguments: @peer *p@ = pointer to peer block
304 * Use: Sends a packet to the peer.
307 static void p_setkatimer(peer *);
309 static int p_dotxend(peer *p)
312 a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
315 IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
316 BBASE(&p->b), BLEN(&p->b)); )
317 if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b),
318 0, &p->spec.sa.sa, p->spec.sasz) < 0) {
319 a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END);
323 p->st.sz_out += BLEN(&p->b);
328 void p_txend(peer *p)
330 if (p_dotxend(p) && p->spec.t_ka) {
331 sel_rmtimer(&p->tka);
336 /* --- @p_pingwrite@ --- *
338 * Arguments: @ping *p@ = ping structure
339 * @buf *b@ = buffer to write in
343 * Use: Fills in a ping structure and writes the packet payload.
346 static void p_pingwrite(ping *p, buf *b)
348 static uint32 seq = 0;
351 GR_FILL(&rand_global, p->magic, sizeof(p->magic));
352 buf_putu32(b, p->id);
353 buf_put(b, p->magic, sizeof(p->magic));
356 /* --- @p_pingdone@ --- *
358 * Arguments: @ping *p@ = ping structure
359 * @int rc@ = return code to pass on
363 * Use: Disposes of a ping structure, maybe sending a notification.
366 void p_pingdone(ping *p, int rc)
368 if (p->prev) p->prev->next = p->next;
369 else p->p->pings = p->next;
370 if (p->next) p->next->prev = p->prev;
371 if (rc != PING_TIMEOUT) sel_rmtimer(&p->t);
372 T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)",
373 (unsigned long)p->id, rc); )
374 if (rc >= 0) p->func(rc, p->arg);
377 /* --- @p_pingtimeout@ --- *
379 * Arguments: @struct timeval *now@ = the time now
380 * @void *pv@ = pointer to ping block
384 * Use: Called when a ping times out.
387 static void p_pingtimeout(struct timeval *now, void *pv)
391 T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); )
392 p_pingdone(p, PING_TIMEOUT);
395 /* --- @p_pingsend@ --- *
397 * Arguments: @peer *p@ = destination peer
398 * @ping *pg@ = structure to fill in
399 * @unsigned type@ = message type
400 * @unsigned long timeout@ = how long to wait before giving up
401 * @void (*func)(int, void *)@ = callback function
402 * @void *arg@ = argument for callback
404 * Returns: Zero if successful, nonzero if it failed.
406 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
407 * if we get an answer within the timeout, or zero if no answer.
410 int p_pingsend(peer *p, ping *pg, unsigned type,
411 unsigned long timeout,
412 void (*func)(int, void *), void *arg)
420 b = p_txstart(p, MSG_MISC | MISC_PING);
425 pg->msg = MISC_EPONG;
426 b = p_txstart(p, MSG_MISC | MISC_EPING);
427 buf_init(&bb, buf_t, sizeof(buf_t));
428 p_pingwrite(pg, &bb);
430 if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPING, &bb, b))
446 if (p->pings) p->pings->prev = pg;
448 gettimeofday(&tv, 0);
449 tv.tv_sec += timeout;
450 sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg);
451 T( trace(T_PEER, "peer: send %s 0x%08lx to %s",
452 p_pingtype(type), (unsigned long)pg->id, p->spec.name); )
456 /* --- @p_greet@ --- *
458 * Arguments: @peer *p@ = peer to send to
459 * @const void *c@ = pointer to challenge
460 * @size_t sz@ = size of challenge
464 * Use: Sends a greeting packet.
467 void p_greet(peer *p, const void *c, size_t sz)
469 buf *b = p_txstart(p, MSG_MISC | MISC_GREET);
476 * Arguments: @peer *p@ = pointer to peer block
477 * @buf *b@ = buffer containing incoming packet
481 * Use: Handles a packet which needs to be sent to a peer.
484 void p_tun(peer *p, buf *b)
486 buf *bb = p_txstart(p, MSG_PACKET);
489 if (ksl_encrypt(&p->ks, MSG_PACKET, b, bb))
491 if (BOK(bb) && BLEN(bb)) {
493 p->st.sz_ipout += BLEN(bb);
498 /* --- @p_keyreload@ --- *
504 * Use: Forces a check of the daemon's keyring files.
507 void p_keyreload(void)
510 FOREACH_PEER(p, { kx_newkeys(&p->kx); });
513 /* --- @p_interval@ --- *
519 * Use: Called periodically to do tidying.
522 void p_interval(void)
525 FOREACH_PEER(p, { ksl_prune(&p->ks); });
528 /* --- @p_stats@ --- *
530 * Arguments: @peer *p@ = pointer to a peer block
532 * Returns: A pointer to the peer's statistics.
535 stats *p_stats(peer *p) { return (&p->st); }
537 /* --- @p_ifname@ --- *
539 * Arguments: @peer *p@ = pointer to a peer block
541 * Returns: A pointer to the peer's interface name.
544 const char *p_ifname(peer *p) { return (p->ifname); }
546 /* --- @p_setifname@ --- *
548 * Arguments: @peer *p@ = pointer to a peer block
549 * @const char *name@ = pointer to the new name
553 * Use: Changes the name held for a peer's interface.
556 void p_setifname(peer *p, const char *name)
559 p->ifname = xstrdup(name);
560 if (p->spec.tops->setifname)
561 p->spec.tops->setifname(p->t, name);
564 /* --- @p_addr@ --- *
566 * Arguments: @peer *p@ = pointer to a peer block
568 * Returns: A pointer to the peer's address.
571 const addr *p_addr(peer *p) { return (&p->spec.sa); }
573 /* --- @p_init@ --- *
575 * Arguments: @struct in_addr addr@ = address to bind to
576 * @unsigned port@ = port number to listen to
580 * Use: Initializes the peer system; creates the socket.
583 void p_init(struct in_addr addr, unsigned port)
586 struct sockaddr_in sin;
589 /* --- Note on socket buffer sizes --- *
591 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
592 * sizes I pass to @setsockopt@. I'm not putting special-case code here
593 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
597 if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
598 die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
600 sin.sin_family = AF_INET;
602 sin.sin_port = htons(port);
603 if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
604 die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
605 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
606 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
607 die(EXIT_FAILURE, "failed to set socket buffer sizes: %s",
610 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
611 sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0);
613 T( trace(T_PEER, "peer: created socket"); )
619 /* --- @p_port@ --- *
623 * Returns: Port number used for socket.
626 unsigned p_port(void)
629 size_t sz = sizeof(addr);
631 if (getsockname(sock.fd, &a.sa, &sz))
632 die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
633 assert(a.sa.sa_family == AF_INET);
634 return (ntohs(a.sin.sin_port));
637 /* --- @p_keepalive@ --- *
639 * Arguments: @struct timeval *now@ = the current time
640 * @void *pv@ = peer to wake up
644 * Use: Sends a keepalive ping message to its peer.
647 static void p_keepalive(struct timeval *now, void *pv)
650 p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p);
651 T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); )
655 /* --- @p_setkatimer@ --- *
657 * Arguments: @peer *p@ = peer to set
661 * Use: Resets the keepalive timer thing.
664 static void p_setkatimer(peer *p)
670 gettimeofday(&tv, 0);
671 tv.tv_sec += p->spec.t_ka;
672 sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p);
675 /* --- @p_create@ --- *
677 * Arguments: @peerspec *spec@ = information about this peer
679 * Returns: Pointer to the peer block, or null if it failed.
681 * Use: Creates a new named peer block. No peer is actually attached
685 peer *p_create(peerspec *spec)
687 peer *p = CREATE(peer);
690 p->byname = sym_find(&byname, spec->name, -1, sizeof(peer_byname), &f);
692 p->byaddr = am_find(&byaddr, &spec->sa, sizeof(peer_byaddr), &f);
694 p->byname->p = p->byaddr->p = p;
696 T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); )
698 p->spec.name = (/*unconst*/ char *)SYM_NAME(p->byname);
702 memset(&p->st, 0, sizeof(stats));
703 p->st.t_start = time(0);
704 if ((p->t = spec->tops->create(p, &p->ifname)) == 0)
707 if (kx_init(&p->kx, p, &p->ks, p->spec.kxf))
712 "?ADDR", &p->spec.sa,
714 if (!(p->spec.kxf & KXF_CORK)) {
715 a_notify("KXSTART", "?PEER", p, A_END);
716 /* Couldn't tell anyone before */
722 sel_rmtimer(&p->tka);
724 p->t->ops->destroy(p->t);
726 am_remove(&byaddr, p->byaddr);
728 sym_remove(&byname, p->byname);
734 /* --- @p_name@ --- *
736 * Arguments: @peer *p@ = pointer to a peer block
738 * Returns: A pointer to the peer's name.
741 const char *p_name(peer *p) { return (p->spec.name); }
743 /* --- @p_spec@ --- *
745 * Arguments: @peer *p@ = pointer to a peer block
747 * Returns: Pointer to the peer's specification
750 const peerspec *p_spec(peer *p) { return (&p->spec); }
752 /* --- @p_findbyaddr@ --- *
754 * Arguments: @const addr *a@ = address to look up
756 * Returns: Pointer to the peer block, or null if not found.
758 * Use: Finds a peer by address.
761 peer *p_findbyaddr(const addr *a)
765 if ((pa = am_find(&byaddr, a, 0, 0)) != 0)
770 /* --- @p_find@ --- *
772 * Arguments: @const char *name@ = name to look up
774 * Returns: Pointer to the peer block, or null if not found.
776 * Use: Finds a peer by name.
779 peer *p_find(const char *name)
783 if ((pn = sym_find(&byname, name, -1, 0, 0)) != 0)
788 /* --- @p_destroy@ --- *
790 * Arguments: @peer *p@ = pointer to a peer
794 * Use: Destroys a peer.
797 void p_destroy(peer *p)
801 T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); )
802 a_notify("KILL", "%s", p->spec.name, A_END);
807 p->t->ops->destroy(p->t);
809 sel_rmtimer(&p->tka);
810 for (pg = p->pings; pg; pg = ppg) {
812 p_pingdone(pg, PING_PEERDIED);
814 sym_remove(&byname, p->byname);
815 am_remove(&byaddr, p->byaddr);
819 /* --- @p_mkiter@ --- *
821 * Arguments: @peer_iter *i@ = pointer to an iterator
825 * Use: Initializes the iterator.
828 void p_mkiter(peer_iter *i) { sym_mkiter(&i->i, &byname); }
830 /* --- @p_next@ --- *
832 * Arguments: @peer_iter *i@ = pointer to an iterator
834 * Returns: Next peer, or null if at the end.
836 * Use: Returns the next peer.
839 peer *p_next(peer_iter *i)
843 if ((pn = sym_next(&i->i)) == 0)
848 /*----- That's all, folks -------------------------------------------------*/