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_encrypt@ --- *
127 * Arguments: @peer *p@ = peer to encrypt message to
128 * @int ty@ message type to send
129 * @buf *bin, *bout@ = input and output buffers
133 * Use: Convenience function for packet encryption. Forces
134 * renegotiation when necessary. Check for the output buffer
135 * being broken to find out whether the encryption was
139 static int p_encrypt(peer *p, int ty, buf *bin, buf *bout)
141 int err = ksl_encrypt(&p->ks, ty, bin, bout);
143 if (err == KSERR_REGEN) {
152 /* --- @p_decrypt@ --- *
154 * Arguments: @peer *p@ = peer to decrypt message from
155 * @int ty@ = message type to expect
156 * @buf *bin, *bout@ = input and output buffers
158 * Returns: Zero on success; nonzero on error.
160 * Use: Convenience function for packet decryption. Reports errors
161 * and updates statistics appropriately.
164 static int p_decrypt(peer *p, int ty, buf *bin, buf *bout)
166 if (ksl_decrypt(&p->ks, ty, bin, bout)) {
168 a_warn("PEER", "?PEER", p, "decrypt-failed", A_END);
176 /* --- @p_read@ --- *
178 * Arguments: @int fd@ = file descriptor to read from
179 * @unsigned mode@ = what happened
180 * @void *v@ = an uninteresting pointer
184 * Use: Reads a packet from somewhere.
187 static void p_read(int fd, unsigned mode, void *v)
196 /* --- Read the data --- */
200 n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
202 a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END);
206 /* --- If the packet is a greeting, don't check peers --- */
208 if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) {
210 trace(T_PEER, "peer: greeting received from INET %s %u",
211 inet_ntoa(a.sin.sin_addr),
212 (unsigned)ntohs(a.sin.sin_port));
213 trace_block(T_PACKET, "peer: greeting contents", buf_i, n);
215 buf_init(&b, buf_i, n);
217 if (c_check(&b) || BLEFT(&b)) {
218 a_warn("PEER", "-", "invalid-greeting", A_END);
222 "?B64", buf_i + 1, (size_t)(n - 1),
228 /* --- Find the appropriate peer --- */
230 if ((p = p_findbyaddr(&a)) == 0) {
231 a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END);
236 trace(T_PEER, "peer: packet received from `%s'", p->spec.name);
237 trace_block(T_PACKET, "peer: packet contents", buf_i, n);
240 /* --- Pick the packet apart --- */
242 p->st.t_last = time(0);
245 buf_init(&b, buf_i, n);
246 if ((ch = buf_getbyte(&b)) < 0) {
247 a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END);
250 switch (ch & MSG_CATMASK) {
252 if (ch & MSG_TYPEMASK) {
256 "unknown-type", "0x%02x", ch,
261 buf_init(&bb, buf_o, sizeof(buf_o));
262 if (p_decrypt(p, MSG_PACKET, &b, &bb))
266 p->st.sz_ipin += BSZ(&b);
267 p->t->ops->inject(p->t, &bb);
270 a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
274 kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
277 switch (ch & MSG_TYPEMASK) {
279 T( trace(T_PEER, "peer: received NOP packet"); )
282 buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b));
286 p_ponged(p, MISC_PONG, &b);
289 buf_init(&bb, buf_t, sizeof(buf_t));
290 if (p_decrypt(p, ch, &b, &bb))
294 p_encrypt(p, MSG_MISC | MISC_EPONG, &bb,
295 p_txstart(p, MSG_MISC | MISC_EPONG));
300 buf_init(&bb, buf_t, sizeof(buf_t));
301 if (p_decrypt(p, ch, &b, &bb))
305 p_ponged(p, MISC_EPONG, &bb);
315 "unknown-category" "0x%02x", ch,
321 /* --- @p_txstart@ --- *
323 * Arguments: @peer *p@ = pointer to peer block
324 * @unsigned msg@ = message type code
326 * Returns: A pointer to a buffer to write to.
328 * Use: Starts sending to a peer. Only one send can happen at a
332 buf *p_txstart(peer *p, unsigned msg)
334 buf_init(&p->b, buf_o, sizeof(buf_o));
335 buf_putbyte(&p->b, msg);
339 /* --- @p_txend@ --- *
341 * Arguments: @peer *p@ = pointer to peer block
345 * Use: Sends a packet to the peer.
348 static void p_setkatimer(peer *);
350 static int p_dotxend(peer *p)
353 a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
356 IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
357 BBASE(&p->b), BLEN(&p->b)); )
358 if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b),
359 0, &p->spec.sa.sa, p->spec.sasz) < 0) {
360 a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END);
364 p->st.sz_out += BLEN(&p->b);
369 void p_txend(peer *p)
371 if (p_dotxend(p) && p->spec.t_ka) {
372 sel_rmtimer(&p->tka);
377 /* --- @p_pingwrite@ --- *
379 * Arguments: @ping *p@ = ping structure
380 * @buf *b@ = buffer to write in
384 * Use: Fills in a ping structure and writes the packet payload.
387 static void p_pingwrite(ping *p, buf *b)
389 static uint32 seq = 0;
392 GR_FILL(&rand_global, p->magic, sizeof(p->magic));
393 buf_putu32(b, p->id);
394 buf_put(b, p->magic, sizeof(p->magic));
397 /* --- @p_pingdone@ --- *
399 * Arguments: @ping *p@ = ping structure
400 * @int rc@ = return code to pass on
404 * Use: Disposes of a ping structure, maybe sending a notification.
407 void p_pingdone(ping *p, int rc)
409 if (p->prev) p->prev->next = p->next;
410 else p->p->pings = p->next;
411 if (p->next) p->next->prev = p->prev;
412 if (rc != PING_TIMEOUT) sel_rmtimer(&p->t);
413 T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)",
414 (unsigned long)p->id, rc); )
415 if (rc >= 0) p->func(rc, p->arg);
418 /* --- @p_pingtimeout@ --- *
420 * Arguments: @struct timeval *now@ = the time now
421 * @void *pv@ = pointer to ping block
425 * Use: Called when a ping times out.
428 static void p_pingtimeout(struct timeval *now, void *pv)
432 T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); )
433 p_pingdone(p, PING_TIMEOUT);
436 /* --- @p_pingsend@ --- *
438 * Arguments: @peer *p@ = destination peer
439 * @ping *pg@ = structure to fill in
440 * @unsigned type@ = message type
441 * @unsigned long timeout@ = how long to wait before giving up
442 * @void (*func)(int, void *)@ = callback function
443 * @void *arg@ = argument for callback
445 * Returns: Zero if successful, nonzero if it failed.
447 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
448 * if we get an answer within the timeout, or zero if no answer.
451 int p_pingsend(peer *p, ping *pg, unsigned type,
452 unsigned long timeout,
453 void (*func)(int, void *), void *arg)
461 b = p_txstart(p, MSG_MISC | MISC_PING);
466 pg->msg = MISC_EPONG;
467 b = p_txstart(p, MSG_MISC | MISC_EPING);
468 buf_init(&bb, buf_t, sizeof(buf_t));
469 p_pingwrite(pg, &bb);
471 p_encrypt(p, MSG_MISC | MISC_EPING, &bb, b);
486 if (p->pings) p->pings->prev = pg;
488 gettimeofday(&tv, 0);
489 tv.tv_sec += timeout;
490 sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg);
491 T( trace(T_PEER, "peer: send %s 0x%08lx to %s",
492 p_pingtype(type), (unsigned long)pg->id, p->spec.name); )
496 /* --- @p_greet@ --- *
498 * Arguments: @peer *p@ = peer to send to
499 * @const void *c@ = pointer to challenge
500 * @size_t sz@ = size of challenge
504 * Use: Sends a greeting packet.
507 void p_greet(peer *p, const void *c, size_t sz)
509 buf *b = p_txstart(p, MSG_MISC | MISC_GREET);
516 * Arguments: @peer *p@ = pointer to peer block
517 * @buf *b@ = buffer containing incoming packet
521 * Use: Handles a packet which needs to be sent to a peer.
524 void p_tun(peer *p, buf *b)
526 buf *bb = p_txstart(p, MSG_PACKET);
529 p_encrypt(p, MSG_PACKET, b, bb);
530 if (BOK(bb) && BLEN(bb)) {
532 p->st.sz_ipout += BLEN(bb);
537 /* --- @p_keyreload@ --- *
543 * Use: Forces a check of the daemon's keyring files.
546 void p_keyreload(void)
549 FOREACH_PEER(p, { kx_newkeys(&p->kx); });
552 /* --- @p_interval@ --- *
558 * Use: Called periodically to do tidying.
561 void p_interval(void)
564 FOREACH_PEER(p, { ksl_prune(&p->ks); });
567 /* --- @p_stats@ --- *
569 * Arguments: @peer *p@ = pointer to a peer block
571 * Returns: A pointer to the peer's statistics.
574 stats *p_stats(peer *p) { return (&p->st); }
576 /* --- @p_ifname@ --- *
578 * Arguments: @peer *p@ = pointer to a peer block
580 * Returns: A pointer to the peer's interface name.
583 const char *p_ifname(peer *p) { return (p->ifname); }
585 /* --- @p_setifname@ --- *
587 * Arguments: @peer *p@ = pointer to a peer block
588 * @const char *name@ = pointer to the new name
592 * Use: Changes the name held for a peer's interface.
595 void p_setifname(peer *p, const char *name)
598 p->ifname = xstrdup(name);
599 if (p->spec.tops->setifname)
600 p->spec.tops->setifname(p->t, name);
603 /* --- @p_addr@ --- *
605 * Arguments: @peer *p@ = pointer to a peer block
607 * Returns: A pointer to the peer's address.
610 const addr *p_addr(peer *p) { return (&p->spec.sa); }
612 /* --- @p_init@ --- *
614 * Arguments: @struct in_addr addr@ = address to bind to
615 * @unsigned port@ = port number to listen to
619 * Use: Initializes the peer system; creates the socket.
622 void p_init(struct in_addr addr, unsigned port)
625 struct sockaddr_in sin;
628 /* --- Note on socket buffer sizes --- *
630 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
631 * sizes I pass to @setsockopt@. I'm not putting special-case code here
632 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
636 if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
637 die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
639 sin.sin_family = AF_INET;
641 sin.sin_port = htons(port);
642 if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
643 die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
644 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
645 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
646 die(EXIT_FAILURE, "failed to set socket buffer sizes: %s",
649 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
650 sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0);
652 T( trace(T_PEER, "peer: created socket"); )
658 /* --- @p_port@ --- *
662 * Returns: Port number used for socket.
665 unsigned p_port(void)
668 size_t sz = sizeof(addr);
670 if (getsockname(sock.fd, &a.sa, &sz))
671 die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
672 assert(a.sa.sa_family == AF_INET);
673 return (ntohs(a.sin.sin_port));
676 /* --- @p_keepalive@ --- *
678 * Arguments: @struct timeval *now@ = the current time
679 * @void *pv@ = peer to wake up
683 * Use: Sends a keepalive ping message to its peer.
686 static void p_keepalive(struct timeval *now, void *pv)
689 p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p);
690 T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); )
694 /* --- @p_setkatimer@ --- *
696 * Arguments: @peer *p@ = peer to set
700 * Use: Resets the keepalive timer thing.
703 static void p_setkatimer(peer *p)
709 gettimeofday(&tv, 0);
710 tv.tv_sec += p->spec.t_ka;
711 sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p);
714 /* --- @p_create@ --- *
716 * Arguments: @peerspec *spec@ = information about this peer
718 * Returns: Pointer to the peer block, or null if it failed.
720 * Use: Creates a new named peer block. No peer is actually attached
724 peer *p_create(peerspec *spec)
726 peer *p = CREATE(peer);
727 const tunnel_ops *tops = spec->tops;
731 p->byname = sym_find(&byname, spec->name, -1, sizeof(peer_byname), &f);
733 p->byaddr = am_find(&byaddr, &spec->sa, sizeof(peer_byaddr), &f);
735 p->byname->p = p->byaddr->p = p;
737 T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); )
739 p->spec.name = (/*unconst*/ char *)SYM_NAME(p->byname);
743 memset(&p->st, 0, sizeof(stats));
744 p->st.t_start = time(0);
745 if (!(tops->flags & TUNF_PRIVOPEN))
747 else if ((fd = ps_tunfd(tops, &p->ifname)) < 0)
749 if ((p->t = tops->create(p, fd, &p->ifname)) == 0)
751 T( trace(T_TUNNEL, "peer: attached interface %s to peer `%s'",
752 p->ifname, p_name(p)); )
754 if (kx_init(&p->kx, p, &p->ks, p->spec.kxf))
759 "?ADDR", &p->spec.sa,
761 if (!(p->spec.kxf & KXF_CORK)) {
762 a_notify("KXSTART", "?PEER", p, A_END);
763 /* Couldn't tell anyone before */
769 sel_rmtimer(&p->tka);
771 p->t->ops->destroy(p->t);
773 if (fd >= 0) close(fd);
775 am_remove(&byaddr, p->byaddr);
777 sym_remove(&byname, p->byname);
783 /* --- @p_name@ --- *
785 * Arguments: @peer *p@ = pointer to a peer block
787 * Returns: A pointer to the peer's name.
790 const char *p_name(peer *p) { return (p->spec.name); }
792 /* --- @p_spec@ --- *
794 * Arguments: @peer *p@ = pointer to a peer block
796 * Returns: Pointer to the peer's specification
799 const peerspec *p_spec(peer *p) { return (&p->spec); }
801 /* --- @p_findbyaddr@ --- *
803 * Arguments: @const addr *a@ = address to look up
805 * Returns: Pointer to the peer block, or null if not found.
807 * Use: Finds a peer by address.
810 peer *p_findbyaddr(const addr *a)
814 if ((pa = am_find(&byaddr, a, 0, 0)) != 0)
819 /* --- @p_find@ --- *
821 * Arguments: @const char *name@ = name to look up
823 * Returns: Pointer to the peer block, or null if not found.
825 * Use: Finds a peer by name.
828 peer *p_find(const char *name)
832 if ((pn = sym_find(&byname, name, -1, 0, 0)) != 0)
837 /* --- @p_destroy@ --- *
839 * Arguments: @peer *p@ = pointer to a peer
843 * Use: Destroys a peer.
846 void p_destroy(peer *p)
850 T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); )
851 a_notify("KILL", "%s", p->spec.name, A_END);
856 p->t->ops->destroy(p->t);
858 sel_rmtimer(&p->tka);
859 for (pg = p->pings; pg; pg = ppg) {
861 p_pingdone(pg, PING_PEERDIED);
863 sym_remove(&byname, p->byname);
864 am_remove(&byaddr, p->byaddr);
868 /* --- @p_mkiter@ --- *
870 * Arguments: @peer_iter *i@ = pointer to an iterator
874 * Use: Initializes the iterator.
877 void p_mkiter(peer_iter *i) { sym_mkiter(&i->i, &byname); }
879 /* --- @p_next@ --- *
881 * Arguments: @peer_iter *i@ = pointer to an iterator
883 * Returns: Next peer, or null if at the end.
885 * Use: Returns the next peer.
888 peer *p_next(peer_iter *i)
892 if ((pn = sym_next(&i->i)) == 0)
897 /*----- That's all, folks -------------------------------------------------*/