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;
36 static unsigned nmobile;
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_rxupdstats@ --- *
128 * Arguments: @peer *p@ = peer to update
129 * @size_t n@ = size of incoming packet
133 * Use: Updates the peer's incoming packet statistics.
136 static void p_rxupdstats(peer *p, size_t n)
138 p->st.t_last = time(0);
143 /* --- @p_encrypt@ --- *
145 * Arguments: @peer *p@ = peer to encrypt message to
146 * @int ty@ message type to send
147 * @buf *bin, *bout@ = input and output buffers
151 * Use: Convenience function for packet encryption. Forces
152 * renegotiation when necessary. Check for the output buffer
153 * being broken to find out whether the encryption was
157 static int p_encrypt(peer *p, int ty, buf *bin, buf *bout)
159 int err = ksl_encrypt(&p->ks, ty, bin, bout);
161 if (err == KSERR_REGEN) {
170 /* --- @p_decrypt@ --- *
172 * Arguments: @peer **pp@ = pointer to peer to decrypt message from
173 * @addr *a@ = address the packet arrived on
174 * @size_t n@ = size of original incoming packet
175 * @int ty@ = message type to expect
176 * @buf *bin, *bout@ = input and output buffers
178 * Returns: Zero on success; nonzero on error.
180 * Use: Convenience function for packet decryption. Reports errors
181 * and updates statistics appropriately.
183 * If @*pp@ is null on entry and there are mobile peers then we
184 * see if any of them can decrypt the packet. If so, we record
185 * @*a@ as the peer's new address and send a notification.
188 static int p_decrypt(peer **pp, addr *a, size_t n,
189 int ty, buf *bin, buf *bout)
193 int err = KSERR_DECRYPT;
198 T( trace(T_PEER, "peer: decrypting packet from known peer `%s'",
200 err = ksl_decrypt(&p->ks, ty, bin, bout);
204 T( trace(T_PEER, "peer: unknown source: trying mobile peers..."); )
206 if (!(q->spec.f & PSF_MOBILE)) continue;
207 if ((err = ksl_decrypt(&q->ks, ty, bin, bout)) == KSERR_DECRYPT) {
208 T( trace(T_PEER, "peer: peer `%s' failed to decrypt",
215 trace(T_PEER, "peer: peer `%s' reports success", p_name(p));
217 trace(T_PEER, "peer: peer `%s' reports decryption error %d",
226 a_warn("PEER", "-", "unexpected-source", "?ADDR", a, A_END);
230 T( trace(T_PEER, "peer: updating address for `%s'", p_name(p)); )
232 pa = am_find(&byaddr, a, sizeof(peer_byaddr), &f); assert(!f);
233 am_remove(&byaddr, p->byaddr);
237 a_notify("NEWADDR", "?PEER", p, "?ADDR", a, A_END);
241 if (p) p->st.n_reject++;
242 a_warn("PEER", "?PEER", p, "decrypt-failed",
243 "error-code", "%d", err, A_END);
251 /* --- @p_read@ --- *
253 * Arguments: @int fd@ = file descriptor to read from
254 * @unsigned mode@ = what happened
255 * @void *v@ = an uninteresting pointer
259 * Use: Reads a packet from somewhere.
262 static void p_read(int fd, unsigned mode, void *v)
271 /* --- Read the data --- */
275 n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
277 a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END);
281 /* --- If the packet is a greeting, don't check peers --- */
283 if (n && buf_i[0] == (MSG_MISC | MISC_GREET)) {
285 trace(T_PEER, "peer: greeting received from INET %s %u",
286 inet_ntoa(a.sin.sin_addr),
287 (unsigned)ntohs(a.sin.sin_port));
288 trace_block(T_PACKET, "peer: greeting contents", buf_i, n);
290 buf_init(&b, buf_i, n);
292 if (c_check(&b) || BLEFT(&b)) {
293 a_warn("PEER", "-", "invalid-greeting", A_END);
297 "?B64", buf_i + 1, (size_t)(n - 1),
303 /* --- Find the appropriate peer --- *
305 * At this stage, don't worry too much about whether we actually found it.
308 p = p_findbyaddr(&a);
313 "peer: packet received from `%s' from address INET %s %d",
314 p_name(p), inet_ntoa(a.sin.sin_addr), ntohs(a.sin.sin_port));
316 trace(T_PEER, "peer: packet received from unknown address INET %s %d",
317 inet_ntoa(a.sin.sin_addr), ntohs(a.sin.sin_port));
319 trace_block(T_PACKET, "peer: packet contents", buf_i, n);
322 /* --- Pick the packet apart --- */
324 if (p) p_rxupdstats(p, n);
325 buf_init(&b, buf_i, n);
326 if ((ch = buf_getbyte(&b)) < 0) {
327 a_warn("PEER", "?PEER", p, "bad-packet", "no-type", A_END);
330 switch (ch & MSG_CATMASK) {
332 if (ch & MSG_TYPEMASK) {
336 "unknown-type", "0x%02x", ch,
338 if (p) p->st.n_reject++;
341 buf_init(&bb, buf_o, sizeof(buf_o));
342 if (p_decrypt(&p, &a, n, MSG_PACKET, &b, &bb))
346 p->st.sz_ipin += BSZ(&b);
347 p->t->ops->inject(p->t, &bb);
350 a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
355 kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
358 switch (ch & MSG_TYPEMASK) {
361 T( trace(T_PEER, "peer: received NOP packet"); )
365 buf_put(p_txstart(p, MSG_MISC | MISC_PONG), BCUR(&b), BLEFT(&b));
370 p_ponged(p, MISC_PONG, &b);
373 buf_init(&bb, buf_t, sizeof(buf_t));
374 if (p_decrypt(&p, &a, n, ch, &b, &bb))
378 p_encrypt(p, MSG_MISC | MISC_EPONG, &bb,
379 p_txstart(p, MSG_MISC | MISC_EPONG));
384 buf_init(&bb, buf_t, sizeof(buf_t));
385 if (p_decrypt(&p, &a, n, ch, &b, &bb))
389 p_ponged(p, MISC_EPONG, &bb);
395 if (p) p->st.n_reject++;
399 "unknown-category", "0x%02x", ch,
403 a_warn("PEER", "-", "unexpected-source", "?ADDR", &a, A_END);
408 /* --- @p_txstart@ --- *
410 * Arguments: @peer *p@ = pointer to peer block
411 * @unsigned msg@ = message type code
413 * Returns: A pointer to a buffer to write to.
415 * Use: Starts sending to a peer. Only one send can happen at a
419 buf *p_txstart(peer *p, unsigned msg)
421 buf_init(&p->b, buf_o, sizeof(buf_o));
422 buf_putbyte(&p->b, msg);
426 /* --- @p_txend@ --- *
428 * Arguments: @peer *p@ = pointer to peer block
432 * Use: Sends a packet to the peer.
435 static void p_setkatimer(peer *);
437 static int p_dotxend(peer *p)
440 a_warn("PEER", "?PEER", p, "packet-build-failed", A_END);
443 IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
444 BBASE(&p->b), BLEN(&p->b)); )
445 if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b),
446 0, &p->spec.sa.sa, p->spec.sasz) < 0) {
447 a_warn("PEER", "?PEER", p, "socket-write-error", "?ERRNO", A_END);
451 p->st.sz_out += BLEN(&p->b);
456 void p_txend(peer *p)
458 if (p_dotxend(p) && p->spec.t_ka) {
459 sel_rmtimer(&p->tka);
464 /* --- @p_pingwrite@ --- *
466 * Arguments: @ping *p@ = ping structure
467 * @buf *b@ = buffer to write in
471 * Use: Fills in a ping structure and writes the packet payload.
474 static void p_pingwrite(ping *p, buf *b)
476 static uint32 seq = 0;
479 GR_FILL(&rand_global, p->magic, sizeof(p->magic));
480 buf_putu32(b, p->id);
481 buf_put(b, p->magic, sizeof(p->magic));
484 /* --- @p_pingdone@ --- *
486 * Arguments: @ping *p@ = ping structure
487 * @int rc@ = return code to pass on
491 * Use: Disposes of a ping structure, maybe sending a notification.
494 void p_pingdone(ping *p, int rc)
496 if (p->prev) p->prev->next = p->next;
497 else p->p->pings = p->next;
498 if (p->next) p->next->prev = p->prev;
499 if (rc != PING_TIMEOUT) sel_rmtimer(&p->t);
500 T( trace(T_PEER, "peer: ping 0x%08lx done (rc = %d)",
501 (unsigned long)p->id, rc); )
502 if (rc >= 0) p->func(rc, p->arg);
505 /* --- @p_pingtimeout@ --- *
507 * Arguments: @struct timeval *now@ = the time now
508 * @void *pv@ = pointer to ping block
512 * Use: Called when a ping times out.
515 static void p_pingtimeout(struct timeval *now, void *pv)
519 T( trace(T_PEER, "peer: ping 0x%08lx timed out", (unsigned long)p->id); )
520 p_pingdone(p, PING_TIMEOUT);
523 /* --- @p_pingsend@ --- *
525 * Arguments: @peer *p@ = destination peer
526 * @ping *pg@ = structure to fill in
527 * @unsigned type@ = message type
528 * @unsigned long timeout@ = how long to wait before giving up
529 * @void (*func)(int, void *)@ = callback function
530 * @void *arg@ = argument for callback
532 * Returns: Zero if successful, nonzero if it failed.
534 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
535 * if we get an answer within the timeout, or zero if no answer.
538 int p_pingsend(peer *p, ping *pg, unsigned type,
539 unsigned long timeout,
540 void (*func)(int, void *), void *arg)
548 b = p_txstart(p, MSG_MISC | MISC_PING);
553 pg->msg = MISC_EPONG;
554 b = p_txstart(p, MSG_MISC | MISC_EPING);
555 buf_init(&bb, buf_t, sizeof(buf_t));
556 p_pingwrite(pg, &bb);
558 p_encrypt(p, MSG_MISC | MISC_EPING, &bb, b);
573 if (p->pings) p->pings->prev = pg;
575 gettimeofday(&tv, 0);
576 tv.tv_sec += timeout;
577 sel_addtimer(&sel, &pg->t, &tv, p_pingtimeout, pg);
578 T( trace(T_PEER, "peer: send %s 0x%08lx to %s",
579 p_pingtype(type), (unsigned long)pg->id, p->spec.name); )
583 /* --- @p_greet@ --- *
585 * Arguments: @peer *p@ = peer to send to
586 * @const void *c@ = pointer to challenge
587 * @size_t sz@ = size of challenge
591 * Use: Sends a greeting packet.
594 void p_greet(peer *p, const void *c, size_t sz)
596 buf *b = p_txstart(p, MSG_MISC | MISC_GREET);
603 * Arguments: @peer *p@ = pointer to peer block
604 * @buf *b@ = buffer containing incoming packet
608 * Use: Handles a packet which needs to be sent to a peer.
611 void p_tun(peer *p, buf *b)
613 buf *bb = p_txstart(p, MSG_PACKET);
616 p_encrypt(p, MSG_PACKET, b, bb);
617 if (BOK(bb) && BLEN(bb)) {
619 p->st.sz_ipout += BLEN(bb);
624 /* --- @p_keyreload@ --- *
630 * Use: Forces a check of the daemon's keyring files.
633 void p_keyreload(void)
636 FOREACH_PEER(p, { kx_newkeys(&p->kx); });
639 /* --- @p_interval@ --- *
645 * Use: Called periodically to do tidying.
648 void p_interval(void)
651 FOREACH_PEER(p, { ksl_prune(&p->ks); });
654 /* --- @p_stats@ --- *
656 * Arguments: @peer *p@ = pointer to a peer block
658 * Returns: A pointer to the peer's statistics.
661 stats *p_stats(peer *p) { return (&p->st); }
663 /* --- @p_ifname@ --- *
665 * Arguments: @peer *p@ = pointer to a peer block
667 * Returns: A pointer to the peer's interface name.
670 const char *p_ifname(peer *p) { return (p->ifname); }
672 /* --- @p_setifname@ --- *
674 * Arguments: @peer *p@ = pointer to a peer block
675 * @const char *name@ = pointer to the new name
679 * Use: Changes the name held for a peer's interface.
682 void p_setifname(peer *p, const char *name)
685 p->ifname = xstrdup(name);
686 if (p->spec.tops->setifname)
687 p->spec.tops->setifname(p->t, name);
690 /* --- @p_addr@ --- *
692 * Arguments: @peer *p@ = pointer to a peer block
694 * Returns: A pointer to the peer's address.
697 const addr *p_addr(peer *p) { return (&p->spec.sa); }
699 /* --- @p_init@ --- *
701 * Arguments: @struct in_addr addr@ = address to bind to
702 * @unsigned port@ = port number to listen to
706 * Use: Initializes the peer system; creates the socket.
709 void p_init(struct in_addr addr, unsigned port)
712 struct sockaddr_in sin;
715 /* --- Note on socket buffer sizes --- *
717 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
718 * sizes I pass to @setsockopt@. I'm not putting special-case code here
719 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
723 if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
724 die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
726 sin.sin_family = AF_INET;
728 sin.sin_port = htons(port);
729 if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
730 die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
731 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
732 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
733 die(EXIT_FAILURE, "failed to set socket buffer sizes: %s",
736 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
737 sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0);
739 T( trace(T_PEER, "peer: created socket"); )
745 /* --- @p_port@ --- *
749 * Returns: Port number used for socket.
752 unsigned p_port(void)
755 size_t sz = sizeof(addr);
757 if (getsockname(sock.fd, &a.sa, &sz))
758 die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
759 assert(a.sa.sa_family == AF_INET);
760 return (ntohs(a.sin.sin_port));
763 /* --- @p_keepalive@ --- *
765 * Arguments: @struct timeval *now@ = the current time
766 * @void *pv@ = peer to wake up
770 * Use: Sends a keepalive ping message to its peer.
773 static void p_keepalive(struct timeval *now, void *pv)
776 p_txstart(p, MSG_MISC | MISC_NOP); p_dotxend(p);
777 T( trace(T_PEER, "peer: sent keepalive to %s", p->spec.name); )
781 /* --- @p_setkatimer@ --- *
783 * Arguments: @peer *p@ = peer to set
787 * Use: Resets the keepalive timer thing.
790 static void p_setkatimer(peer *p)
796 gettimeofday(&tv, 0);
797 tv.tv_sec += p->spec.t_ka;
798 sel_addtimer(&sel, &p->tka, &tv, p_keepalive, p);
801 /* --- @p_create@ --- *
803 * Arguments: @peerspec *spec@ = information about this peer
805 * Returns: Pointer to the peer block, or null if it failed.
807 * Use: Creates a new named peer block. No peer is actually attached
811 peer *p_create(peerspec *spec)
813 peer *p = CREATE(peer);
814 const tunnel_ops *tops = spec->tops;
818 p->byname = sym_find(&byname, spec->name, -1, sizeof(peer_byname), &f);
820 p->byaddr = am_find(&byaddr, &spec->sa, sizeof(peer_byaddr), &f);
822 p->byname->p = p->byaddr->p = p;
824 T( trace(T_PEER, "peer: creating new peer `%s'", spec->name); )
826 p->spec.name = (/*unconst*/ char *)SYM_NAME(p->byname);
828 p->spec.tag = xstrdup(spec->tag);
832 memset(&p->st, 0, sizeof(stats));
833 p->st.t_start = time(0);
834 if (!(tops->flags & TUNF_PRIVOPEN))
836 else if ((fd = ps_tunfd(tops, &p->ifname)) < 0)
838 if ((p->t = tops->create(p, fd, &p->ifname)) == 0)
840 T( trace(T_TUNNEL, "peer: attached interface %s to peer `%s'",
841 p->ifname, p_name(p)); )
843 if (kx_init(&p->kx, p, &p->ks, p->spec.f & PSF_KXMASK))
848 "?ADDR", &p->spec.sa,
850 if (!(p->spec.f & KXF_CORK)) {
851 a_notify("KXSTART", "?PEER", p, A_END);
852 /* Couldn't tell anyone before */
854 if (p->spec.f & PSF_MOBILE) nmobile++;
859 sel_rmtimer(&p->tka);
861 p->t->ops->destroy(p->t);
863 if (fd >= 0) close(fd);
865 am_remove(&byaddr, p->byaddr);
866 if (p->spec.tag) xfree(p->spec.tag);
868 sym_remove(&byname, p->byname);
874 /* --- @p_name@ --- *
876 * Arguments: @peer *p@ = pointer to a peer block
878 * Returns: A pointer to the peer's name.
881 const char *p_name(peer *p)
882 { if (p) return (p->spec.name); else return ("-"); }
886 * Arguments: @peer *p@ = pointer to a peer block
888 * Returns: A pointer to the peer's public key tag.
891 const char *p_tag(peer *p)
892 { return (p->spec.tag ? p->spec.tag : p->spec.name); }
894 /* --- @p_spec@ --- *
896 * Arguments: @peer *p@ = pointer to a peer block
898 * Returns: Pointer to the peer's specification
901 const peerspec *p_spec(peer *p) { return (&p->spec); }
903 /* --- @p_findbyaddr@ --- *
905 * Arguments: @const addr *a@ = address to look up
907 * Returns: Pointer to the peer block, or null if not found.
909 * Use: Finds a peer by address.
912 peer *p_findbyaddr(const addr *a)
916 if ((pa = am_find(&byaddr, a, 0, 0)) != 0) {
923 /* --- @p_find@ --- *
925 * Arguments: @const char *name@ = name to look up
927 * Returns: Pointer to the peer block, or null if not found.
929 * Use: Finds a peer by name.
932 peer *p_find(const char *name)
936 if ((pn = sym_find(&byname, name, -1, 0, 0)) != 0)
941 /* --- @p_destroy@ --- *
943 * Arguments: @peer *p@ = pointer to a peer
947 * Use: Destroys a peer.
950 void p_destroy(peer *p)
954 T( trace(T_PEER, "peer: destroying peer `%s'", p->spec.name); )
955 a_notify("KILL", "%s", p->spec.name, A_END);
958 if (p->spec.f & PSF_MOBILE)
964 p->t->ops->destroy(p->t);
966 sel_rmtimer(&p->tka);
967 for (pg = p->pings; pg; pg = ppg) {
969 p_pingdone(pg, PING_PEERDIED);
971 sym_remove(&byname, p->byname);
972 am_remove(&byaddr, p->byaddr);
976 /* --- @p_mkiter@ --- *
978 * Arguments: @peer_iter *i@ = pointer to an iterator
982 * Use: Initializes the iterator.
985 void p_mkiter(peer_iter *i) { sym_mkiter(&i->i, &byname); }
987 /* --- @p_next@ --- *
989 * Arguments: @peer_iter *i@ = pointer to an iterator
991 * Returns: Next peer, or null if at the end.
993 * Use: Returns the next peer.
996 peer *p_next(peer_iter *i)
1000 if ((pn = sym_next(&i->i)) == 0)
1005 /*----- That's all, folks -------------------------------------------------*/