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
);
741 p
->spec
.tag
= xstrdup(spec
->tag
);
745 memset(&p
->st
, 0, sizeof(stats
));
746 p
->st
.t_start
= time(0);
747 if (!(tops
->flags
& TUNF_PRIVOPEN
))
749 else if ((fd
= ps_tunfd(tops
, &p
->ifname
)) < 0)
751 if ((p
->t
= tops
->create(p
, fd
, &p
->ifname
)) == 0)
753 T( trace(T_TUNNEL
, "peer: attached interface %s to peer `%s'",
754 p
->ifname
, p_name(p
)); )
756 if (kx_init(&p
->kx
, p
, &p
->ks
, p
->spec
.kxf
))
761 "?ADDR", &p
->spec
.sa
,
763 if (!(p
->spec
.kxf
& KXF_CORK
)) {
764 a_notify("KXSTART", "?PEER", p
, A_END
);
765 /* Couldn't tell anyone before */
771 sel_rmtimer(&p
->tka
);
773 p
->t
->ops
->destroy(p
->t
);
775 if (fd
>= 0) close(fd
);
777 am_remove(&byaddr
, p
->byaddr
);
778 if (p
->spec
.tag
) xfree(p
->spec
.tag
);
780 sym_remove(&byname
, p
->byname
);
786 /* --- @p_name@ --- *
788 * Arguments: @peer *p@ = pointer to a peer block
790 * Returns: A pointer to the peer's name.
793 const char *p_name(peer
*p
) { return (p
->spec
.name
); }
797 * Arguments: @peer *p@ = pointer to a peer block
799 * Returns: A pointer to the peer's public key tag.
802 const char *p_tag(peer
*p
)
803 { return (p
->spec
.tag ? p
->spec
.tag
: p
->spec
.name
); }
805 /* --- @p_spec@ --- *
807 * Arguments: @peer *p@ = pointer to a peer block
809 * Returns: Pointer to the peer's specification
812 const peerspec
*p_spec(peer
*p
) { return (&p
->spec
); }
814 /* --- @p_findbyaddr@ --- *
816 * Arguments: @const addr *a@ = address to look up
818 * Returns: Pointer to the peer block, or null if not found.
820 * Use: Finds a peer by address.
823 peer
*p_findbyaddr(const addr
*a
)
827 if ((pa
= am_find(&byaddr
, a
, 0, 0)) != 0)
832 /* --- @p_find@ --- *
834 * Arguments: @const char *name@ = name to look up
836 * Returns: Pointer to the peer block, or null if not found.
838 * Use: Finds a peer by name.
841 peer
*p_find(const char *name
)
845 if ((pn
= sym_find(&byname
, name
, -1, 0, 0)) != 0)
850 /* --- @p_destroy@ --- *
852 * Arguments: @peer *p@ = pointer to a peer
856 * Use: Destroys a peer.
859 void p_destroy(peer
*p
)
863 T( trace(T_PEER
, "peer: destroying peer `%s'", p
->spec
.name
); )
864 a_notify("KILL", "%s", p
->spec
.name
, A_END
);
871 p
->t
->ops
->destroy(p
->t
);
873 sel_rmtimer(&p
->tka
);
874 for (pg
= p
->pings
; pg
; pg
= ppg
) {
876 p_pingdone(pg
, PING_PEERDIED
);
878 sym_remove(&byname
, p
->byname
);
879 am_remove(&byaddr
, p
->byaddr
);
883 /* --- @p_mkiter@ --- *
885 * Arguments: @peer_iter *i@ = pointer to an iterator
889 * Use: Initializes the iterator.
892 void p_mkiter(peer_iter
*i
) { sym_mkiter(&i
->i
, &byname
); }
894 /* --- @p_next@ --- *
896 * Arguments: @peer_iter *i@ = pointer to an iterator
898 * Returns: Next peer, or null if at the end.
900 * Use: Returns the next peer.
903 peer
*p_next(peer_iter
*i
)
907 if ((pn
= sym_next(&i
->i
)) == 0)
912 /*----- That's all, folks -------------------------------------------------*/