6b746ddba220d81b90288dafaad657cc478558fb
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 %s malformed-%s", p
->spec
.name
, p_pingtype(msg
));
107 for (pg
= p
->pings
; pg
; pg
= pg
->next
) {
111 a_warn("PEER %s unexpected-%s 0x%08lx",
112 p
->spec
.name
, p_pingtype(msg
), (unsigned long)id
);
116 if (memcmp(magic
, pg
->magic
, sizeof(pg
->magic
)) != 0) {
117 a_warn("PEER %s corrupt-%s", p
->spec
.name
, p_pingtype(msg
));
120 p_pingdone(pg
, PING_OK
);
123 /* --- @p_read@ --- *
125 * Arguments: @int fd@ = file descriptor to read from
126 * @unsigned mode@ = what happened
127 * @void *v@ = an uninteresting pointer
131 * Use: Reads a packet from somewhere.
134 static void p_read(int fd
, unsigned mode
, void *v
)
143 /* --- Read the data --- */
147 n
= recvfrom(fd
, buf_i
, sizeof(buf_i
), 0, &a
.sa
, &sz
);
149 a_warn("PEER - socket-read-error -- %s", strerror(errno
));
153 /* --- If the packet is a greeting, don't check peers --- */
155 if (n
&& buf_i
[0] == (MSG_MISC
| MISC_GREET
)) {
157 trace(T_PEER
, "peer: greeting received from INET %s %u",
158 inet_ntoa(a
.sin
.sin_addr
),
159 (unsigned)ntohs(a
.sin
.sin_port
));
160 trace_block(T_PACKET
, "peer: greeting contents", buf_i
, n
);
162 buf_init(&b
, buf_i
, n
);
164 if (c_check(&b
) || BLEFT(&b
)) {
165 a_warn("PEER - invalid-greeting");
168 a_notify("GREET %s INET %s %u",
169 b64_encode(buf_i
+ 1, n
- 1),
170 inet_ntoa(a
.sin
.sin_addr
),
171 (unsigned)ntohs(a
.sin
.sin_port
));
175 /* --- Find the appropriate peer --- */
177 assert(a
.sa
.sa_family
== AF_INET
);
178 for (p
= peers
; p
; p
= p
->next
) {
179 if (p
->spec
.sa
.sin
.sin_addr
.s_addr
== a
.sin
.sin_addr
.s_addr
&&
180 p
->spec
.sa
.sin
.sin_port
== a
.sin
.sin_port
)
183 a_warn("PEER - unexpected-source INET %s %u",
184 inet_ntoa(a
.sin
.sin_addr
), (unsigned)ntohs(a
.sin
.sin_port
));
189 trace(T_PEER
, "peer: packet received from `%s'", p
->spec
.name
);
190 trace_block(T_PACKET
, "peer: packet contents", buf_i
, n
);
193 /* --- Pick the packet apart --- */
195 p
->st
.t_last
= time(0);
198 buf_init(&b
, buf_i
, n
);
199 if ((ch
= buf_getbyte(&b
)) < 0) {
200 a_warn("PEER %s bad-packet no-type", p
->spec
.name
);
203 switch (ch
& MSG_CATMASK
) {
205 if (ch
& MSG_TYPEMASK
) {
206 a_warn("PEER %s bad-packet unknown-type 0x%02x", p
->spec
.name
, ch
);
210 buf_init(&bb
, buf_o
, sizeof(buf_o
));
211 if (ksl_decrypt(&p
->ks
, MSG_PACKET
, &b
, &bb
)) {
213 a_warn("PEER %s decrypt-failed", p
->spec
.name
);
218 p
->st
.sz_ipin
+= BSZ(&b
);
219 p
->t
->ops
->inject(p
->t
, &bb
);
222 a_warn("PEER %s packet-build-failed", p
->spec
.name
);
226 kx_message(&p
->kx
, ch
& MSG_TYPEMASK
, &b
);
229 switch (ch
& MSG_TYPEMASK
) {
231 T( trace(T_PEER
, "peer: received NOP packet"); )
234 buf_put(p_txstart(p
, MSG_MISC
| MISC_PONG
), BCUR(&b
), BLEFT(&b
));
238 p_ponged(p
, MISC_PONG
, &b
);
241 buf_init(&bb
, buf_t
, sizeof(buf_t
));
242 if (ksl_decrypt(&p
->ks
, ch
, &b
, &bb
)) {
244 a_warn("PEER %s decrypt-failed", p
->spec
.name
);
249 if (ksl_encrypt(&p
->ks
, MSG_MISC
| MISC_EPONG
, &bb
,
250 p_txstart(p
, MSG_MISC
| MISC_EPONG
)))
256 buf_init(&bb
, buf_t
, sizeof(buf_t
));
257 if (ksl_decrypt(&p
->ks
, ch
, &b
, &bb
)) {
259 a_warn("PEER %s decrypt-failed", p
->spec
.name
);
264 p_ponged(p
, MISC_EPONG
, &bb
);
271 a_warn("PEER %s bad-packet unknown-category 0x%02x", p
->spec
.name
, ch
);
276 /* --- @p_txstart@ --- *
278 * Arguments: @peer *p@ = pointer to peer block
279 * @unsigned msg@ = message type code
281 * Returns: A pointer to a buffer to write to.
283 * Use: Starts sending to a peer. Only one send can happen at a
287 buf
*p_txstart(peer
*p
, unsigned msg
)
289 buf_init(&p
->b
, buf_o
, sizeof(buf_o
));
290 buf_putbyte(&p
->b
, msg
);
294 /* --- @p_txend@ --- *
296 * Arguments: @peer *p@ = pointer to peer block
300 * Use: Sends a packet to the peer.
303 static void p_setkatimer(peer
*);
305 static int p_dotxend(peer
*p
)
308 a_warn("PEER %s packet-build-failed", p
->spec
.name
);
311 IF_TRACING(T_PEER
, trace_block(T_PACKET
, "peer: sending packet",
312 BBASE(&p
->b
), BLEN(&p
->b
)); )
313 if (sendto(sock
.fd
, BBASE(&p
->b
), BLEN(&p
->b
),
314 0, &p
->spec
.sa
.sa
, p
->spec
.sasz
) < 0) {
315 a_warn("PEER %s socket-write-error -- %s",
316 p
->spec
.name
, strerror(errno
));
320 p
->st
.sz_out
+= BLEN(&p
->b
);
325 void p_txend(peer
*p
)
327 if (p_dotxend(p
) && p
->spec
.t_ka
) {
328 sel_rmtimer(&p
->tka
);
333 /* --- @p_pingwrite@ --- *
335 * Arguments: @ping *p@ = ping structure
336 * @buf *b@ = buffer to write in
340 * Use: Fills in a ping structure and writes the packet payload.
343 static void p_pingwrite(ping
*p
, buf
*b
)
345 static uint32 seq
= 0;
348 GR_FILL(&rand_global
, p
->magic
, sizeof(p
->magic
));
349 buf_putu32(b
, p
->id
);
350 buf_put(b
, p
->magic
, sizeof(p
->magic
));
353 /* --- @p_pingdone@ --- *
355 * Arguments: @ping *p@ = ping structure
356 * @int rc@ = return code to pass on
360 * Use: Disposes of a ping structure, maybe sending a notification.
363 void p_pingdone(ping
*p
, int rc
)
365 if (p
->prev
) p
->prev
->next
= p
->next
;
366 else p
->p
->pings
= p
->next
;
367 if (p
->next
) p
->next
->prev
= p
->prev
;
368 if (rc
!= PING_TIMEOUT
) sel_rmtimer(&p
->t
);
369 T( trace(T_PEER
, "peer: ping 0x%08lx done (rc = %d)",
370 (unsigned long)p
->id
, rc
); )
371 if (rc
>= 0) p
->func(rc
, p
->arg
);
374 /* --- @p_pingtimeout@ --- *
376 * Arguments: @struct timeval *now@ = the time now
377 * @void *pv@ = pointer to ping block
381 * Use: Called when a ping times out.
384 static void p_pingtimeout(struct timeval
*now
, void *pv
)
388 T( trace(T_PEER
, "peer: ping 0x%08lx timed out", (unsigned long)p
->id
); )
389 p_pingdone(p
, PING_TIMEOUT
);
392 /* --- @p_pingsend@ --- *
394 * Arguments: @peer *p@ = destination peer
395 * @ping *pg@ = structure to fill in
396 * @unsigned type@ = message type
397 * @unsigned long timeout@ = how long to wait before giving up
398 * @void (*func)(int, void *)@ = callback function
399 * @void *arg@ = argument for callback
401 * Returns: Zero if successful, nonzero if it failed.
403 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
404 * if we get an answer within the timeout, or zero if no answer.
407 int p_pingsend(peer
*p
, ping
*pg
, unsigned type
,
408 unsigned long timeout
,
409 void (*func
)(int, void *), void *arg
)
417 b
= p_txstart(p
, MSG_MISC
| MISC_PING
);
422 pg
->msg
= MISC_EPONG
;
423 b
= p_txstart(p
, MSG_MISC
| MISC_EPING
);
424 buf_init(&bb
, buf_t
, sizeof(buf_t
));
425 p_pingwrite(pg
, &bb
);
427 if (ksl_encrypt(&p
->ks
, MSG_MISC
| MISC_EPING
, &bb
, b
))
443 if (p
->pings
) p
->pings
->prev
= pg
;
445 gettimeofday(&tv
, 0);
446 tv
.tv_sec
+= timeout
;
447 sel_addtimer(&sel
, &pg
->t
, &tv
, p_pingtimeout
, pg
);
448 T( trace(T_PEER
, "peer: send %s 0x%08lx to %s",
449 p_pingtype(type
), (unsigned long)pg
->id
, p
->spec
.name
); )
453 /* --- @p_greet@ --- *
455 * Arguments: @peer *p@ = peer to send to
456 * @const void *c@ = pointer to challenge
457 * @size_t sz@ = size of challenge
461 * Use: Sends a greeting packet.
464 void p_greet(peer
*p
, const void *c
, size_t sz
)
466 buf
*b
= p_txstart(p
, MSG_MISC
| MISC_GREET
);
473 * Arguments: @peer *p@ = pointer to peer block
474 * @buf *b@ = buffer containing incoming packet
478 * Use: Handles a packet which needs to be sent to a peer.
481 void p_tun(peer
*p
, buf
*b
)
483 buf
*bb
= p_txstart(p
, MSG_PACKET
);
486 if (ksl_encrypt(&p
->ks
, MSG_PACKET
, b
, bb
))
488 if (BOK(bb
) && BLEN(bb
)) {
490 p
->st
.sz_ipout
+= BLEN(bb
);
495 /* --- @p_keyreload@ --- *
501 * Use: Forces a check of the daemon's keyring files.
504 void p_keyreload(void)
509 for (p
= peers
; p
; p
= p
->next
)
514 /* --- @p_interval@ --- *
520 * Use: Called periodically to do tidying.
523 void p_interval(void)
528 for (p
= peers
; p
; p
= p
->next
)
532 /* --- @p_stats@ --- *
534 * Arguments: @peer *p@ = pointer to a peer block
536 * Returns: A pointer to the peer's statistics.
539 stats
*p_stats(peer
*p
) { return (&p
->st
); }
541 /* --- @p_ifname@ --- *
543 * Arguments: @peer *p@ = pointer to a peer block
545 * Returns: A pointer to the peer's interface name.
548 const char *p_ifname(peer
*p
) { return (p
->t
->ops
->ifname(p
->t
)); }
550 /* --- @p_addr@ --- *
552 * Arguments: @peer *p@ = pointer to a peer block
554 * Returns: A pointer to the peer's address.
557 const addr
*p_addr(peer
*p
) { return (&p
->spec
.sa
); }
559 /* --- @p_init@ --- *
561 * Arguments: @struct in_addr addr@ = address to bind to
562 * @unsigned port@ = port number to listen to
566 * Use: Initializes the peer system; creates the socket.
569 void p_init(struct in_addr addr
, unsigned port
)
572 struct sockaddr_in sin
;
575 /* --- Note on socket buffer sizes --- *
577 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
578 * sizes I pass to @setsockopt@. I'm not putting special-case code here
579 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
583 if ((fd
= socket(PF_INET
, SOCK_DGRAM
, 0)) < 0)
584 die(EXIT_FAILURE
, "socket creation failed: %s", strerror(errno
));
586 sin
.sin_family
= AF_INET
;
588 sin
.sin_port
= htons(port
);
589 if (bind(fd
, (struct sockaddr
*)&sin
, sizeof(sin
)))
590 die(EXIT_FAILURE
, "bind failed: %s", strerror(errno
));
591 if (setsockopt(fd
, SOL_SOCKET
, SO_RCVBUF
, &len
, sizeof(len
)) ||
592 setsockopt(fd
, SOL_SOCKET
, SO_SNDBUF
, &len
, sizeof(len
))) {
593 die(EXIT_FAILURE
, "failed to set socket buffer sizes: %s",
596 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
597 sel_initfile(&sel
, &sock
, fd
, SEL_READ
, p_read
, 0);
599 T( trace(T_PEER
, "peer: created socket"); )
602 /* --- @p_port@ --- *
606 * Returns: Port number used for socket.
609 unsigned p_port(void)
612 size_t sz
= sizeof(addr
);
614 if (getsockname(sock
.fd
, &a
.sa
, &sz
))
615 die(EXIT_FAILURE
, "couldn't read port number: %s", strerror(errno
));
616 assert(a
.sa
.sa_family
== AF_INET
);
617 return (ntohs(a
.sin
.sin_port
));
620 /* --- @p_keepalive@ --- *
622 * Arguments: @struct timeval *now@ = the current time
623 * @void *pv@ = peer to wake up
627 * Use: Sends a keepalive ping message to its peer.
630 static void p_keepalive(struct timeval
*now
, void *pv
)
633 p_txstart(p
, MSG_MISC
| MISC_NOP
); p_dotxend(p
);
634 T( trace(T_PEER
, "peer: sent keepalive to %s", p
->spec
.name
); )
638 /* --- @p_setkatimer@ --- *
640 * Arguments: @peer *p@ = peer to set
644 * Use: Resets the keepalive timer thing.
647 static void p_setkatimer(peer
*p
)
653 gettimeofday(&tv
, 0);
654 tv
.tv_sec
+= p
->spec
.t_ka
;
655 sel_addtimer(&sel
, &p
->tka
, &tv
, p_keepalive
, p
);
658 /* --- @p_create@ --- *
660 * Arguments: @peerspec *spec@ = information about this peer
662 * Returns: Pointer to the peer block, or null if it failed.
664 * Use: Creates a new named peer block. No peer is actually attached
668 peer
*p_create(peerspec
*spec
)
670 peer
*p
= CREATE(peer
);
672 T( trace(T_PEER
, "peer: creating new peer `%s'", spec
->name
); )
674 p
->spec
.name
= xstrdup(spec
->name
);
678 memset(&p
->st
, 0, sizeof(stats
));
679 p
->st
.t_start
= time(0);
680 if ((p
->t
= spec
->tops
->create(p
)) == 0)
683 if (kx_init(&p
->kx
, p
, &p
->ks
))
689 switch (p
->spec
.sa
.sa
.sa_family
) {
691 a_notify("ADD %s %s INET %s %u",
693 p
->t
->ops
->ifname(p
->t
),
694 inet_ntoa(p
->spec
.sa
.sin
.sin_addr
),
695 (unsigned)ntohs(p
->spec
.sa
.sin
.sin_port
));
698 a_notify("ADD %s %s UNKNOWN", spec
->name
, p
->t
->ops
->ifname(p
->t
));
701 a_notify("KXSTART %s", spec
->name
); /* Couldn't tell anyone before */
706 sel_rmtimer(&p
->tka
);
707 p
->t
->ops
->destroy(p
->t
);
714 /* --- @p_name@ --- *
716 * Arguments: @peer *p@ = pointer to a peer block
718 * Returns: A pointer to the peer's name.
721 const char *p_name(peer
*p
) { return (p
->spec
.name
); }
723 /* --- @p_spec@ --- *
725 * Arguments: @peer *p@ = pointer to a peer block
727 * Returns: Pointer to the peer's specification
730 const peerspec
*p_spec(peer
*p
) { return (&p
->spec
); }
732 /* --- @p_find@ --- *
734 * Arguments: @const char *name@ = name to look up
736 * Returns: Pointer to the peer block, or null if not found.
738 * Use: Finds a peer by name.
741 peer
*p_find(const char *name
)
744 for (p
= peers
; p
; p
= p
->next
) {
745 if (strcmp(name
, p
->spec
.name
) == 0)
751 /* --- @p_destroy@ --- *
753 * Arguments: @peer *p@ = pointer to a peer
757 * Use: Destroys a peer.
760 void p_destroy(peer
*p
)
764 T( trace(T_PEER
, "peer: destroying peer `%s'", p
->spec
.name
); )
765 a_notify("KILL %s", p
->spec
.name
);
768 p
->t
->ops
->destroy(p
->t
);
770 sel_rmtimer(&p
->tka
);
772 for (pg
= p
->pings
; pg
; pg
= ppg
) {
774 p_pingdone(pg
, PING_PEERDIED
);
777 p
->next
->prev
= p
->prev
;
779 p
->prev
->next
= p
->next
;
785 /* --- @p_first@, @p_next@ --- *
787 * Arguments: @peer *p@ = a peer block
789 * Returns: @peer_first@ returns the first peer in some ordering;
790 * @peer_next@ returns the peer following a given one in the
791 * same ordering. Null is returned for the end of the list.
794 peer
*p_first(void) { return (peers
); }
795 peer
*p_next(peer
*p
) { return (p
->next
); }
797 /*----- That's all, folks -------------------------------------------------*/