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 ((err
= ksl_decrypt(&q
->ks
, ty
, bin
, bout
)) == KSERR_DECRYPT
) {
207 T( trace(T_PEER
, "peer: peer `%s' failed to decrypt",
214 trace(T_PEER
, "peer: peer `%s' reports success", p_name(p
));
216 trace(T_PEER
, "peer: peer `%s' reports decryption error %d",
225 a_warn("PEER", "-", "unexpected-source", "?ADDR", a
, A_END
);
229 T( trace(T_PEER
, "peer: updating address for `%s'", p_name(p
)); )
231 pa
= am_find(&byaddr
, a
, sizeof(peer_byaddr
), &f
); assert(!f
);
232 am_remove(&byaddr
, p
->byaddr
);
236 a_notify("NEWADDR", "?PEER", p
, "?ADDR", a
, A_END
);
240 if (p
) p
->st
.n_reject
++;
241 a_warn("PEER", "?PEER", p
, "decrypt-failed",
242 "error-code", "%d", err
, A_END
);
250 /* --- @p_read@ --- *
252 * Arguments: @int fd@ = file descriptor to read from
253 * @unsigned mode@ = what happened
254 * @void *v@ = an uninteresting pointer
258 * Use: Reads a packet from somewhere.
261 static void p_read(int fd
, unsigned mode
, void *v
)
270 /* --- Read the data --- */
274 n
= recvfrom(fd
, buf_i
, sizeof(buf_i
), 0, &a
.sa
, &sz
);
276 a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END
);
280 /* --- If the packet is a greeting, don't check peers --- */
282 if (n
&& buf_i
[0] == (MSG_MISC
| MISC_GREET
)) {
284 trace(T_PEER
, "peer: greeting received from INET %s %u",
285 inet_ntoa(a
.sin
.sin_addr
),
286 (unsigned)ntohs(a
.sin
.sin_port
));
287 trace_block(T_PACKET
, "peer: greeting contents", buf_i
, n
);
289 buf_init(&b
, buf_i
, n
);
291 if (c_check(&b
) || BLEFT(&b
)) {
292 a_warn("PEER", "-", "invalid-greeting", A_END
);
296 "?B64", buf_i
+ 1, (size_t)(n
- 1),
302 /* --- Find the appropriate peer --- *
304 * At this stage, don't worry too much about whether we actually found it.
307 p
= p_findbyaddr(&a
);
312 "peer: packet received from `%s' from address INET %s %d",
313 p_name(p
), inet_ntoa(a
.sin
.sin_addr
), ntohs(a
.sin
.sin_port
));
315 trace(T_PEER
, "peer: packet received from unknown address INET %s %d",
316 inet_ntoa(a
.sin
.sin_addr
), ntohs(a
.sin
.sin_port
));
318 trace_block(T_PACKET
, "peer: packet contents", buf_i
, n
);
321 /* --- Pick the packet apart --- */
323 if (p
) p_rxupdstats(p
, n
);
324 buf_init(&b
, buf_i
, n
);
325 if ((ch
= buf_getbyte(&b
)) < 0) {
326 a_warn("PEER", "?PEER", p
, "bad-packet", "no-type", A_END
);
329 switch (ch
& MSG_CATMASK
) {
331 if (ch
& MSG_TYPEMASK
) {
335 "unknown-type", "0x%02x", ch
,
337 if (p
) p
->st
.n_reject
++;
340 buf_init(&bb
, buf_o
, sizeof(buf_o
));
341 if (p_decrypt(&p
, &a
, n
, MSG_PACKET
, &b
, &bb
))
345 p
->st
.sz_ipin
+= BSZ(&b
);
346 p
->t
->ops
->inject(p
->t
, &bb
);
349 a_warn("PEER", "?PEER", p
, "packet-build-failed", A_END
);
354 kx_message(&p
->kx
, ch
& MSG_TYPEMASK
, &b
);
357 switch (ch
& MSG_TYPEMASK
) {
360 T( trace(T_PEER
, "peer: received NOP packet"); )
364 buf_put(p_txstart(p
, MSG_MISC
| MISC_PONG
), BCUR(&b
), BLEFT(&b
));
369 p_ponged(p
, MISC_PONG
, &b
);
372 buf_init(&bb
, buf_t
, sizeof(buf_t
));
373 if (p_decrypt(&p
, &a
, n
, ch
, &b
, &bb
))
377 p_encrypt(p
, MSG_MISC
| MISC_EPONG
, &bb
,
378 p_txstart(p
, MSG_MISC
| MISC_EPONG
));
383 buf_init(&bb
, buf_t
, sizeof(buf_t
));
384 if (p_decrypt(&p
, &a
, n
, ch
, &b
, &bb
))
388 p_ponged(p
, MISC_EPONG
, &bb
);
394 if (p
) p
->st
.n_reject
++;
398 "unknown-category" "0x%02x", ch
,
402 a_warn("PEER", "-", "unexpected-source", "?ADDR", &a
, A_END
);
407 /* --- @p_txstart@ --- *
409 * Arguments: @peer *p@ = pointer to peer block
410 * @unsigned msg@ = message type code
412 * Returns: A pointer to a buffer to write to.
414 * Use: Starts sending to a peer. Only one send can happen at a
418 buf
*p_txstart(peer
*p
, unsigned msg
)
420 buf_init(&p
->b
, buf_o
, sizeof(buf_o
));
421 buf_putbyte(&p
->b
, msg
);
425 /* --- @p_txend@ --- *
427 * Arguments: @peer *p@ = pointer to peer block
431 * Use: Sends a packet to the peer.
434 static void p_setkatimer(peer
*);
436 static int p_dotxend(peer
*p
)
439 a_warn("PEER", "?PEER", p
, "packet-build-failed", A_END
);
442 IF_TRACING(T_PEER
, trace_block(T_PACKET
, "peer: sending packet",
443 BBASE(&p
->b
), BLEN(&p
->b
)); )
444 if (sendto(sock
.fd
, BBASE(&p
->b
), BLEN(&p
->b
),
445 0, &p
->spec
.sa
.sa
, p
->spec
.sasz
) < 0) {
446 a_warn("PEER", "?PEER", p
, "socket-write-error", "?ERRNO", A_END
);
450 p
->st
.sz_out
+= BLEN(&p
->b
);
455 void p_txend(peer
*p
)
457 if (p_dotxend(p
) && p
->spec
.t_ka
) {
458 sel_rmtimer(&p
->tka
);
463 /* --- @p_pingwrite@ --- *
465 * Arguments: @ping *p@ = ping structure
466 * @buf *b@ = buffer to write in
470 * Use: Fills in a ping structure and writes the packet payload.
473 static void p_pingwrite(ping
*p
, buf
*b
)
475 static uint32 seq
= 0;
478 GR_FILL(&rand_global
, p
->magic
, sizeof(p
->magic
));
479 buf_putu32(b
, p
->id
);
480 buf_put(b
, p
->magic
, sizeof(p
->magic
));
483 /* --- @p_pingdone@ --- *
485 * Arguments: @ping *p@ = ping structure
486 * @int rc@ = return code to pass on
490 * Use: Disposes of a ping structure, maybe sending a notification.
493 void p_pingdone(ping
*p
, int rc
)
495 if (p
->prev
) p
->prev
->next
= p
->next
;
496 else p
->p
->pings
= p
->next
;
497 if (p
->next
) p
->next
->prev
= p
->prev
;
498 if (rc
!= PING_TIMEOUT
) sel_rmtimer(&p
->t
);
499 T( trace(T_PEER
, "peer: ping 0x%08lx done (rc = %d)",
500 (unsigned long)p
->id
, rc
); )
501 if (rc
>= 0) p
->func(rc
, p
->arg
);
504 /* --- @p_pingtimeout@ --- *
506 * Arguments: @struct timeval *now@ = the time now
507 * @void *pv@ = pointer to ping block
511 * Use: Called when a ping times out.
514 static void p_pingtimeout(struct timeval
*now
, void *pv
)
518 T( trace(T_PEER
, "peer: ping 0x%08lx timed out", (unsigned long)p
->id
); )
519 p_pingdone(p
, PING_TIMEOUT
);
522 /* --- @p_pingsend@ --- *
524 * Arguments: @peer *p@ = destination peer
525 * @ping *pg@ = structure to fill in
526 * @unsigned type@ = message type
527 * @unsigned long timeout@ = how long to wait before giving up
528 * @void (*func)(int, void *)@ = callback function
529 * @void *arg@ = argument for callback
531 * Returns: Zero if successful, nonzero if it failed.
533 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
534 * if we get an answer within the timeout, or zero if no answer.
537 int p_pingsend(peer
*p
, ping
*pg
, unsigned type
,
538 unsigned long timeout
,
539 void (*func
)(int, void *), void *arg
)
547 b
= p_txstart(p
, MSG_MISC
| MISC_PING
);
552 pg
->msg
= MISC_EPONG
;
553 b
= p_txstart(p
, MSG_MISC
| MISC_EPING
);
554 buf_init(&bb
, buf_t
, sizeof(buf_t
));
555 p_pingwrite(pg
, &bb
);
557 p_encrypt(p
, MSG_MISC
| MISC_EPING
, &bb
, b
);
572 if (p
->pings
) p
->pings
->prev
= pg
;
574 gettimeofday(&tv
, 0);
575 tv
.tv_sec
+= timeout
;
576 sel_addtimer(&sel
, &pg
->t
, &tv
, p_pingtimeout
, pg
);
577 T( trace(T_PEER
, "peer: send %s 0x%08lx to %s",
578 p_pingtype(type
), (unsigned long)pg
->id
, p
->spec
.name
); )
582 /* --- @p_greet@ --- *
584 * Arguments: @peer *p@ = peer to send to
585 * @const void *c@ = pointer to challenge
586 * @size_t sz@ = size of challenge
590 * Use: Sends a greeting packet.
593 void p_greet(peer
*p
, const void *c
, size_t sz
)
595 buf
*b
= p_txstart(p
, MSG_MISC
| MISC_GREET
);
602 * Arguments: @peer *p@ = pointer to peer block
603 * @buf *b@ = buffer containing incoming packet
607 * Use: Handles a packet which needs to be sent to a peer.
610 void p_tun(peer
*p
, buf
*b
)
612 buf
*bb
= p_txstart(p
, MSG_PACKET
);
615 p_encrypt(p
, MSG_PACKET
, b
, bb
);
616 if (BOK(bb
) && BLEN(bb
)) {
618 p
->st
.sz_ipout
+= BLEN(bb
);
623 /* --- @p_keyreload@ --- *
629 * Use: Forces a check of the daemon's keyring files.
632 void p_keyreload(void)
635 FOREACH_PEER(p
, { kx_newkeys(&p
->kx
); });
638 /* --- @p_interval@ --- *
644 * Use: Called periodically to do tidying.
647 void p_interval(void)
650 FOREACH_PEER(p
, { ksl_prune(&p
->ks
); });
653 /* --- @p_stats@ --- *
655 * Arguments: @peer *p@ = pointer to a peer block
657 * Returns: A pointer to the peer's statistics.
660 stats
*p_stats(peer
*p
) { return (&p
->st
); }
662 /* --- @p_ifname@ --- *
664 * Arguments: @peer *p@ = pointer to a peer block
666 * Returns: A pointer to the peer's interface name.
669 const char *p_ifname(peer
*p
) { return (p
->ifname
); }
671 /* --- @p_setifname@ --- *
673 * Arguments: @peer *p@ = pointer to a peer block
674 * @const char *name@ = pointer to the new name
678 * Use: Changes the name held for a peer's interface.
681 void p_setifname(peer
*p
, const char *name
)
684 p
->ifname
= xstrdup(name
);
685 if (p
->spec
.tops
->setifname
)
686 p
->spec
.tops
->setifname(p
->t
, name
);
689 /* --- @p_addr@ --- *
691 * Arguments: @peer *p@ = pointer to a peer block
693 * Returns: A pointer to the peer's address.
696 const addr
*p_addr(peer
*p
) { return (&p
->spec
.sa
); }
698 /* --- @p_init@ --- *
700 * Arguments: @struct in_addr addr@ = address to bind to
701 * @unsigned port@ = port number to listen to
705 * Use: Initializes the peer system; creates the socket.
708 void p_init(struct in_addr addr
, unsigned port
)
711 struct sockaddr_in sin
;
714 /* --- Note on socket buffer sizes --- *
716 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
717 * sizes I pass to @setsockopt@. I'm not putting special-case code here
718 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
722 if ((fd
= socket(PF_INET
, SOCK_DGRAM
, 0)) < 0)
723 die(EXIT_FAILURE
, "socket creation failed: %s", strerror(errno
));
725 sin
.sin_family
= AF_INET
;
727 sin
.sin_port
= htons(port
);
728 if (bind(fd
, (struct sockaddr
*)&sin
, sizeof(sin
)))
729 die(EXIT_FAILURE
, "bind failed: %s", strerror(errno
));
730 if (setsockopt(fd
, SOL_SOCKET
, SO_RCVBUF
, &len
, sizeof(len
)) ||
731 setsockopt(fd
, SOL_SOCKET
, SO_SNDBUF
, &len
, sizeof(len
))) {
732 die(EXIT_FAILURE
, "failed to set socket buffer sizes: %s",
735 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
736 sel_initfile(&sel
, &sock
, fd
, SEL_READ
, p_read
, 0);
738 T( trace(T_PEER
, "peer: created socket"); )
744 /* --- @p_port@ --- *
748 * Returns: Port number used for socket.
751 unsigned p_port(void)
754 size_t sz
= sizeof(addr
);
756 if (getsockname(sock
.fd
, &a
.sa
, &sz
))
757 die(EXIT_FAILURE
, "couldn't read port number: %s", strerror(errno
));
758 assert(a
.sa
.sa_family
== AF_INET
);
759 return (ntohs(a
.sin
.sin_port
));
762 /* --- @p_keepalive@ --- *
764 * Arguments: @struct timeval *now@ = the current time
765 * @void *pv@ = peer to wake up
769 * Use: Sends a keepalive ping message to its peer.
772 static void p_keepalive(struct timeval
*now
, void *pv
)
775 p_txstart(p
, MSG_MISC
| MISC_NOP
); p_dotxend(p
);
776 T( trace(T_PEER
, "peer: sent keepalive to %s", p
->spec
.name
); )
780 /* --- @p_setkatimer@ --- *
782 * Arguments: @peer *p@ = peer to set
786 * Use: Resets the keepalive timer thing.
789 static void p_setkatimer(peer
*p
)
795 gettimeofday(&tv
, 0);
796 tv
.tv_sec
+= p
->spec
.t_ka
;
797 sel_addtimer(&sel
, &p
->tka
, &tv
, p_keepalive
, p
);
800 /* --- @p_create@ --- *
802 * Arguments: @peerspec *spec@ = information about this peer
804 * Returns: Pointer to the peer block, or null if it failed.
806 * Use: Creates a new named peer block. No peer is actually attached
810 peer
*p_create(peerspec
*spec
)
812 peer
*p
= CREATE(peer
);
813 const tunnel_ops
*tops
= spec
->tops
;
817 p
->byname
= sym_find(&byname
, spec
->name
, -1, sizeof(peer_byname
), &f
);
819 p
->byaddr
= am_find(&byaddr
, &spec
->sa
, sizeof(peer_byaddr
), &f
);
821 p
->byname
->p
= p
->byaddr
->p
= p
;
823 T( trace(T_PEER
, "peer: creating new peer `%s'", spec
->name
); )
825 p
->spec
.name
= (/*unconst*/ char *)SYM_NAME(p
->byname
);
827 p
->spec
.tag
= xstrdup(spec
->tag
);
831 memset(&p
->st
, 0, sizeof(stats
));
832 p
->st
.t_start
= time(0);
833 if (!(tops
->flags
& TUNF_PRIVOPEN
))
835 else if ((fd
= ps_tunfd(tops
, &p
->ifname
)) < 0)
837 if ((p
->t
= tops
->create(p
, fd
, &p
->ifname
)) == 0)
839 T( trace(T_TUNNEL
, "peer: attached interface %s to peer `%s'",
840 p
->ifname
, p_name(p
)); )
842 if (kx_init(&p
->kx
, p
, &p
->ks
, p
->spec
.f
& PSF_KXMASK
))
847 "?ADDR", &p
->spec
.sa
,
849 if (!(p
->spec
.f
& KXF_CORK
)) {
850 a_notify("KXSTART", "?PEER", p
, A_END
);
851 /* Couldn't tell anyone before */
853 if (p
->spec
.f
& PSF_MOBILE
) nmobile
++;
858 sel_rmtimer(&p
->tka
);
860 p
->t
->ops
->destroy(p
->t
);
862 if (fd
>= 0) close(fd
);
864 am_remove(&byaddr
, p
->byaddr
);
865 if (p
->spec
.tag
) xfree(p
->spec
.tag
);
867 sym_remove(&byname
, p
->byname
);
873 /* --- @p_name@ --- *
875 * Arguments: @peer *p@ = pointer to a peer block
877 * Returns: A pointer to the peer's name.
880 const char *p_name(peer
*p
)
881 { if (p
) return (p
->spec
.name
); else return ("-"); }
885 * Arguments: @peer *p@ = pointer to a peer block
887 * Returns: A pointer to the peer's public key tag.
890 const char *p_tag(peer
*p
)
891 { return (p
->spec
.tag ? p
->spec
.tag
: p
->spec
.name
); }
893 /* --- @p_spec@ --- *
895 * Arguments: @peer *p@ = pointer to a peer block
897 * Returns: Pointer to the peer's specification
900 const peerspec
*p_spec(peer
*p
) { return (&p
->spec
); }
902 /* --- @p_findbyaddr@ --- *
904 * Arguments: @const addr *a@ = address to look up
906 * Returns: Pointer to the peer block, or null if not found.
908 * Use: Finds a peer by address.
911 peer
*p_findbyaddr(const addr
*a
)
915 if ((pa
= am_find(&byaddr
, a
, 0, 0)) != 0) {
922 /* --- @p_find@ --- *
924 * Arguments: @const char *name@ = name to look up
926 * Returns: Pointer to the peer block, or null if not found.
928 * Use: Finds a peer by name.
931 peer
*p_find(const char *name
)
935 if ((pn
= sym_find(&byname
, name
, -1, 0, 0)) != 0)
940 /* --- @p_destroy@ --- *
942 * Arguments: @peer *p@ = pointer to a peer
946 * Use: Destroys a peer.
949 void p_destroy(peer
*p
)
953 T( trace(T_PEER
, "peer: destroying peer `%s'", p
->spec
.name
); )
954 a_notify("KILL", "%s", p
->spec
.name
, A_END
);
957 if (p
->spec
.f
& PSF_MOBILE
)
963 p
->t
->ops
->destroy(p
->t
);
965 sel_rmtimer(&p
->tka
);
966 for (pg
= p
->pings
; pg
; pg
= ppg
) {
968 p_pingdone(pg
, PING_PEERDIED
);
970 sym_remove(&byname
, p
->byname
);
971 am_remove(&byaddr
, p
->byaddr
);
975 /* --- @p_mkiter@ --- *
977 * Arguments: @peer_iter *i@ = pointer to an iterator
981 * Use: Initializes the iterator.
984 void p_mkiter(peer_iter
*i
) { sym_mkiter(&i
->i
, &byname
); }
986 /* --- @p_next@ --- *
988 * Arguments: @peer_iter *i@ = pointer to an iterator
990 * Returns: Next peer, or null if at the end.
992 * Use: Returns the next peer.
995 peer
*p_next(peer_iter
*i
)
999 if ((pn
= sym_next(&i
->i
)) == 0)
1004 /*----- That's all, folks -------------------------------------------------*/