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 /* --- @p_pingtype@ --- *
58 * Arguments: @unsigned msg@ = message type
60 * Returns: String to describe the message.
63 static const char *p_pingtype(unsigned msg)
65 switch (msg & MSG_TYPEMASK) {
68 return "transport-ping";
71 return "encrypted-ping";
77 /* --- @p_ponged@ --- *
79 * Arguments: @peer *p@ = peer packet arrived from
80 * @unsigned msg@ = message type
81 * @buf *b@ = buffer containing payload
85 * Use: Processes a ping response.
88 static void p_ponged(peer *p, unsigned msg, buf *b)
95 trace(T_PEER, "peer: received %s reply from %s",
96 p_pingtype(msg), p->spec.name);
97 trace_block(T_PACKET, "peer: ping contents", BBASE(b), BSZ(b));
100 if (buf_getu32(b, &id) ||
101 (magic = buf_get(b, sizeof(pg->magic))) == 0 ||
103 a_warn("PEER", "?PEER", p, "malformed-%s", p_pingtype(msg), A_END);
107 for (pg = p->pings; pg; pg = pg->next) {
113 "unexpected-%s", p_pingtype(msg),
114 "0x%08lx", (unsigned long)id,
119 if (memcmp(magic, pg->magic, sizeof(pg->magic)) != 0) {
120 a_warn("PEER", "?PEER", p, "corrupt-%s", p_pingtype(msg), A_END);
123 p_pingdone(pg, PING_OK);
126 /* --- @p_read@ --- *
128 * Arguments: @int fd@ = file descriptor to read from
129 * @unsigned mode@ = what happened
130 * @void *v@ = an uninteresting pointer
134 * Use: Reads a packet from somewhere.
137 static void p_read(int fd, unsigned mode, void *v)
146 /* --- Read the data --- */
150 n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
152 a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END);
156 /* --- If the packet is a greeting, don't check peers --- */
158 if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) {
160 trace(T_PEER, "peer: greeting received from INET %s %u",
161 inet_ntoa(a.sin.sin_addr),
162 (unsigned)ntohs(a.sin.sin_port));
163 trace_block(T_PACKET, "peer: greeting contents", buf_i, n);
165 buf_init(&b, buf_i, n);
167 if (c_check(&b) || BLEFT(&b)) {
168 a_warn("PEER", "-", "invalid-greeting", A_END);
172 "?B64", buf_i + 1, (size_t)(n - 1),
178 /* --- Find the appropriate peer --- */
180 assert(a.sa.sa_family == AF_INET);
181 for (p = peers; p; p = p->next) {
182 if (p->spec.sa.sin.sin_addr.s_addr == a.sin.sin_addr.s_addr &&
183 p->spec.sa.sin.sin_port == a.sin.sin_port)
186 a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END);
191 trace(T_PEER, "peer: packet received from `%s'", p->spec.name);
192 trace_block(T_PACKET, "peer: packet contents", buf_i, n);
195 /* --- Pick the packet apart --- */
197 p->st.t_last = time(0);
200 buf_init(&b, buf_i, n);
201 if ((ch = buf_getbyte(&b)) < 0) {
202 a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END);
205 switch (ch & MSG_CATMASK) {
207 if (ch & MSG_TYPEMASK) {
211 "unknown-type", "0x%02x", ch,
216 buf_init(&bb, buf_o, sizeof(buf_o));
217 if (ksl_decrypt(&p->ks, MSG_PACKET, &b, &bb)) {
219 a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
224 p->st.sz_ipin += BSZ(&b);
225 p->t->ops->inject(p->t, &bb);
228 a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
232 kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
235 switch (ch & MSG_TYPEMASK) {
237 T( trace(T_PEER, "peer: received NOP packet"); )
240 buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b));
244 p_ponged(p, MISC_PONG, &b);
247 buf_init(&bb, buf_t, sizeof(buf_t));
248 if (ksl_decrypt(&p->ks, ch, &b, &bb)) {
250 a_warn("PEER", "?PEER", "decrypt-failed", A_END);
255 if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPONG, &bb,
256 p_txstart(p, MSG_MISC | MISC_EPONG)))
262 buf_init(&bb, buf_t, sizeof(buf_t));
263 if (ksl_decrypt(&p->ks, ch, &b, &bb)) {
265 a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
270 p_ponged(p, MISC_EPONG, &bb);
280 "unknown-category" "0x%02x", ch,
286 /* --- @p_txstart@ --- *
288 * Arguments: @peer *p@ = pointer to peer block
289 * @unsigned msg@ = message type code
291 * Returns: A pointer to a buffer to write to.
293 * Use: Starts sending to a peer. Only one send can happen at a
297 buf *p_txstart(peer *p, unsigned msg)
299 buf_init(&p->b, buf_o, sizeof(buf_o));
300 buf_putbyte(&p->b, msg);
304 /* --- @p_txend@ --- *
306 * Arguments: @peer *p@ = pointer to peer block
310 * Use: Sends a packet to the peer.
313 static void p_setkatimer(peer *);
315 static int p_dotxend(peer *p)
318 a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
321 IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
322 BBASE(&p->b), BLEN(&p->b)); )
323 if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b),
324 0, &p->spec.sa.sa, p->spec.sasz) < 0) {
325 a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END);
329 p->st.sz_out += BLEN(&p->b);
334 void p_txend(peer *p)
336 if (p_dotxend(p) && p->spec.t_ka) {
337 sel_rmtimer(&p->tka);
342 /* --- @p_pingwrite@ --- *
344 * Arguments: @ping *p@ = ping structure
345 * @buf *b@ = buffer to write in
349 * Use: Fills in a ping structure and writes the packet payload.
352 static void p_pingwrite(ping *p, buf *b)
354 static uint32 seq = 0;
357 GR_FILL(&rand_global, p->magic, sizeof(p->magic));
358 buf_putu32(b, p->id);
359 buf_put(b, p->magic, sizeof(p->magic));
362 /* --- @p_pingdone@ --- *
364 * Arguments: @ping *p@ = ping structure
365 * @int rc@ = return code to pass on
369 * Use: Disposes of a ping structure, maybe sending a notification.
372 void p_pingdone(ping *p, int rc)
374 if (p->prev) p->prev->next = p->next;
375 else p->p->pings = p->next;
376 if (p->next) p->next->prev = p->prev;
377 if (rc != PING_TIMEOUT) sel_rmtimer(&p->t);
378 T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)",
379 (unsigned long)p->id, rc); )
380 if (rc >= 0) p->func(rc, p->arg);
383 /* --- @p_pingtimeout@ --- *
385 * Arguments: @struct timeval *now@ = the time now
386 * @void *pv@ = pointer to ping block
390 * Use: Called when a ping times out.
393 static void p_pingtimeout(struct timeval *now, void *pv)
397 T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); )
398 p_pingdone(p, PING_TIMEOUT);
401 /* --- @p_pingsend@ --- *
403 * Arguments: @peer *p@ = destination peer
404 * @ping *pg@ = structure to fill in
405 * @unsigned type@ = message type
406 * @unsigned long timeout@ = how long to wait before giving up
407 * @void (*func)(int, void *)@ = callback function
408 * @void *arg@ = argument for callback
410 * Returns: Zero if successful, nonzero if it failed.
412 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
413 * if we get an answer within the timeout, or zero if no answer.
416 int p_pingsend(peer *p, ping *pg, unsigned type,
417 unsigned long timeout,
418 void (*func)(int, void *), void *arg)
426 b = p_txstart(p, MSG_MISC | MISC_PING);
431 pg->msg = MISC_EPONG;
432 b = p_txstart(p, MSG_MISC | MISC_EPING);
433 buf_init(&bb, buf_t, sizeof(buf_t));
434 p_pingwrite(pg, &bb);
436 if (ksl_encrypt(&p->ks, MSG_MISC | MISC_EPING, &bb, b))
452 if (p->pings) p->pings->prev = pg;
454 gettimeofday(&tv, 0);
455 tv.tv_sec += timeout;
456 sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg);
457 T( trace(T_PEER, "peer: send %s 0x%08lx to %s",
458 p_pingtype(type), (unsigned long)pg->id, p->spec.name); )
462 /* --- @p_greet@ --- *
464 * Arguments: @peer *p@ = peer to send to
465 * @const void *c@ = pointer to challenge
466 * @size_t sz@ = size of challenge
470 * Use: Sends a greeting packet.
473 void p_greet(peer *p, const void *c, size_t sz)
475 buf *b = p_txstart(p, MSG_MISC | MISC_GREET);
482 * Arguments: @peer *p@ = pointer to peer block
483 * @buf *b@ = buffer containing incoming packet
487 * Use: Handles a packet which needs to be sent to a peer.
490 void p_tun(peer *p, buf *b)
492 buf *bb = p_txstart(p, MSG_PACKET);
495 if (ksl_encrypt(&p->ks, MSG_PACKET, b, bb))
497 if (BOK(bb) && BLEN(bb)) {
499 p->st.sz_ipout += BLEN(bb);
504 /* --- @p_keyreload@ --- *
510 * Use: Forces a check of the daemon's keyring files.
513 void p_keyreload(void)
518 for (p = peers; p; p = p->next)
523 /* --- @p_interval@ --- *
529 * Use: Called periodically to do tidying.
532 void p_interval(void)
537 for (p = peers; p; p = p->next)
541 /* --- @p_stats@ --- *
543 * Arguments: @peer *p@ = pointer to a peer block
545 * Returns: A pointer to the peer's statistics.
548 stats *p_stats(peer *p) { return (&p->st); }
550 /* --- @p_ifname@ --- *
552 * Arguments: @peer *p@ = pointer to a peer block
554 * Returns: A pointer to the peer's interface name.
557 const char *p_ifname(peer *p) { return (p->t->ops->ifname(p->t)); }
559 /* --- @p_addr@ --- *
561 * Arguments: @peer *p@ = pointer to a peer block
563 * Returns: A pointer to the peer's address.
566 const addr *p_addr(peer *p) { return (&p->spec.sa); }
568 /* --- @p_init@ --- *
570 * Arguments: @struct in_addr addr@ = address to bind to
571 * @unsigned port@ = port number to listen to
575 * Use: Initializes the peer system; creates the socket.
578 void p_init(struct in_addr addr, unsigned port)
581 struct sockaddr_in sin;
584 /* --- Note on socket buffer sizes --- *
586 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
587 * sizes I pass to @setsockopt@. I'm not putting special-case code here
588 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
592 if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
593 die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
595 sin.sin_family = AF_INET;
597 sin.sin_port = htons(port);
598 if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
599 die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
600 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
601 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
602 die(EXIT_FAILURE, "failed to set socket buffer sizes: %s",
605 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
606 sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0);
608 T( trace(T_PEER, "peer: created socket"); )
611 /* --- @p_port@ --- *
615 * Returns: Port number used for socket.
618 unsigned p_port(void)
621 size_t sz = sizeof(addr);
623 if (getsockname(sock.fd, &a.sa, &sz))
624 die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
625 assert(a.sa.sa_family == AF_INET);
626 return (ntohs(a.sin.sin_port));
629 /* --- @p_keepalive@ --- *
631 * Arguments: @struct timeval *now@ = the current time
632 * @void *pv@ = peer to wake up
636 * Use: Sends a keepalive ping message to its peer.
639 static void p_keepalive(struct timeval *now, void *pv)
642 p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p);
643 T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); )
647 /* --- @p_setkatimer@ --- *
649 * Arguments: @peer *p@ = peer to set
653 * Use: Resets the keepalive timer thing.
656 static void p_setkatimer(peer *p)
662 gettimeofday(&tv, 0);
663 tv.tv_sec += p->spec.t_ka;
664 sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p);
667 /* --- @p_create@ --- *
669 * Arguments: @peerspec *spec@ = information about this peer
671 * Returns: Pointer to the peer block, or null if it failed.
673 * Use: Creates a new named peer block. No peer is actually attached
677 peer *p_create(peerspec *spec)
679 peer *p = CREATE(peer);
681 T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); )
683 p->spec.name = xstrdup(spec->name);
687 memset(&p->st, 0, sizeof(stats));
688 p->st.t_start = time(0);
689 if ((p->t = spec->tops->create(p)) == 0)
692 if (kx_init(&p->kx, p, &p->ks))
700 "%s", p->t->ops->ifname(p->t),
701 "?ADDR", &p->spec.sa,
703 a_notify("KXSTART", "?PEER", p, A_END);
704 /* Couldn't tell anyone before */
709 sel_rmtimer(&p->tka);
710 p->t->ops->destroy(p->t);
717 /* --- @p_name@ --- *
719 * Arguments: @peer *p@ = pointer to a peer block
721 * Returns: A pointer to the peer's name.
724 const char *p_name(peer *p) { return (p->spec.name); }
726 /* --- @p_spec@ --- *
728 * Arguments: @peer *p@ = pointer to a peer block
730 * Returns: Pointer to the peer's specification
733 const peerspec *p_spec(peer *p) { return (&p->spec); }
735 /* --- @p_find@ --- *
737 * Arguments: @const char *name@ = name to look up
739 * Returns: Pointer to the peer block, or null if not found.
741 * Use: Finds a peer by name.
744 peer *p_find(const char *name)
747 for (p = peers; p; p = p->next) {
748 if (strcmp(name, p->spec.name) == 0)
754 /* --- @p_destroy@ --- *
756 * Arguments: @peer *p@ = pointer to a peer
760 * Use: Destroys a peer.
763 void p_destroy(peer *p)
767 T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); )
768 a_notify("KILL", "%s", p->spec.name, A_END);
771 p->t->ops->destroy(p->t);
773 sel_rmtimer(&p->tka);
775 for (pg = p->pings; pg; pg = ppg) {
777 p_pingdone(pg, PING_PEERDIED);
780 p->next->prev = p->prev;
782 p->prev->next = p->next;
788 /* --- @p_first@, @p_next@ --- *
790 * Arguments: @peer *p@ = a peer block
792 * Returns: @peer_first@ returns the first peer in some ordering;
793 * @peer_next@ returns the peer following a given one in the
794 * same ordering. Null is returned for the end of the list.
797 peer *p_first(void) { return (peers); }
798 peer *p_next(peer *p) { return (p->next); }
800 /*----- That's all, folks -------------------------------------------------*/