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", "?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_read@ --- *
128 * Arguments: @int fd@ = file descriptor to read from
129 * @unsigned mode@ = what happened
130 * @void *v@ = an uninteresting pointer
134 * Use: Reads a packet from somewhere.
137 static void p_read(int fd
, unsigned mode
, void *v
)
146 /* --- Read the data --- */
150 n
= recvfrom(fd
, buf_i
, sizeof(buf_i
), 0, &a
.sa
, &sz
);
152 a_warn("PEER", "-", "socket-read-error", "?ERRNO", A_END
);
156 /* --- If the packet is a greeting, don't check peers --- */
158 if (n
&& buf_i
[0] == (MSG_MISC
| MISC_GREET
)) {
160 trace(T_PEER
, "peer: greeting received from INET %s %u",
161 inet_ntoa(a
.sin
.sin_addr
),
162 (unsigned)ntohs(a
.sin
.sin_port
));
163 trace_block(T_PACKET
, "peer: greeting contents", buf_i
, n
);
165 buf_init(&b
, buf_i
, n
);
167 if (c_check(&b
) || BLEFT(&b
)) {
168 a_warn("PEER", "-", "invalid-greeting", A_END
);
172 "?B64", buf_i
+ 1, (size_t)(n
- 1),
178 /* --- Find the appropriate peer --- */
180 assert(a
.sa
.sa_family
== AF_INET
);
181 for (p
= peers
; p
; p
= p
->next
) {
182 if (p
->spec
.sa
.sin
.sin_addr
.s_addr
== a
.sin
.sin_addr
.s_addr
&&
183 p
->spec
.sa
.sin
.sin_port
== a
.sin
.sin_port
)
186 a_warn("PEER", "-", "unexpected-source", "?ADDR", &a
, A_END
);
191 trace(T_PEER
, "peer: packet received from `%s'", p
->spec
.name
);
192 trace_block(T_PACKET
, "peer: packet contents", buf_i
, n
);
195 /* --- Pick the packet apart --- */
197 p
->st
.t_last
= time(0);
200 buf_init(&b
, buf_i
, n
);
201 if ((ch
= buf_getbyte(&b
)) < 0) {
202 a_warn("PEER", "?PEER", p
, "bad-packet", "no-type", A_END
);
205 switch (ch
& MSG_CATMASK
) {
207 if (ch
& MSG_TYPEMASK
) {
211 "unknown-type", "0x%02x", ch
,
216 buf_init(&bb
, buf_o
, sizeof(buf_o
));
217 if (ksl_decrypt(&p
->ks
, MSG_PACKET
, &b
, &bb
)) {
219 a_warn("PEER", "?PEER", p
, "decrypt-failed", A_END
);
224 p
->st
.sz_ipin
+= BSZ(&b
);
225 p
->t
->ops
->inject(p
->t
, &bb
);
228 a_warn("PEER", "?PEER", p
, "packet-build-failed", A_END
);
232 kx_message(&p
->kx
, ch
& MSG_TYPEMASK
, &b
);
235 switch (ch
& MSG_TYPEMASK
) {
237 T( trace(T_PEER
, "peer: received NOP packet"); )
240 buf_put(p_txstart(p
, MSG_MISC
| MISC_PONG
), BCUR(&b
), BLEFT(&b
));
244 p_ponged(p
, MISC_PONG
, &b
);
247 buf_init(&bb
, buf_t
, sizeof(buf_t
));
248 if (ksl_decrypt(&p
->ks
, ch
, &b
, &bb
)) {
250 a_warn("PEER", "?PEER", "decrypt-failed", A_END
);
255 if (ksl_encrypt(&p
->ks
, MSG_MISC
| MISC_EPONG
, &bb
,
256 p_txstart(p
, MSG_MISC
| MISC_EPONG
)))
262 buf_init(&bb
, buf_t
, sizeof(buf_t
));
263 if (ksl_decrypt(&p
->ks
, ch
, &b
, &bb
)) {
265 a_warn("PEER", "?PEER", p
, "decrypt-failed", A_END
);
270 p_ponged(p
, MISC_EPONG
, &bb
);
280 "unknown-category" "0x%02x", ch
,
286 /* --- @p_txstart@ --- *
288 * Arguments: @peer *p@ = pointer to peer block
289 * @unsigned msg@ = message type code
291 * Returns: A pointer to a buffer to write to.
293 * Use: Starts sending to a peer. Only one send can happen at a
297 buf
*p_txstart(peer
*p
, unsigned msg
)
299 buf_init(&p
->b
, buf_o
, sizeof(buf_o
));
300 buf_putbyte(&p
->b
, msg
);
304 /* --- @p_txend@ --- *
306 * Arguments: @peer *p@ = pointer to peer block
310 * Use: Sends a packet to the peer.
313 static void p_setkatimer(peer
*);
315 static int p_dotxend(peer
*p
)
318 a_warn("PEER", "?PEER", p
, "packet-build-failed", A_END
);
321 IF_TRACING(T_PEER
, trace_block(T_PACKET
, "peer: sending packet",
322 BBASE(&p
->b
), BLEN(&p
->b
)); )
323 if (sendto(sock
.fd
, BBASE(&p
->b
), BLEN(&p
->b
),
324 0, &p
->spec
.sa
.sa
, p
->spec
.sasz
) < 0) {
325 a_warn("PEER", "?PEER", p
, "socket-write-error", "?ERRNO", A_END
);
329 p
->st
.sz_out
+= BLEN(&p
->b
);
334 void p_txend(peer
*p
)
336 if (p_dotxend(p
) && p
->spec
.t_ka
) {
337 sel_rmtimer(&p
->tka
);
342 /* --- @p_pingwrite@ --- *
344 * Arguments: @ping *p@ = ping structure
345 * @buf *b@ = buffer to write in
349 * Use: Fills in a ping structure and writes the packet payload.
352 static void p_pingwrite(ping
*p
, buf
*b
)
354 static uint32 seq
= 0;
357 GR_FILL(&rand_global
, p
->magic
, sizeof(p
->magic
));
358 buf_putu32(b
, p
->id
);
359 buf_put(b
, p
->magic
, sizeof(p
->magic
));
362 /* --- @p_pingdone@ --- *
364 * Arguments: @ping *p@ = ping structure
365 * @int rc@ = return code to pass on
369 * Use: Disposes of a ping structure, maybe sending a notification.
372 void p_pingdone(ping
*p
, int rc
)
374 if (p
->prev
) p
->prev
->next
= p
->next
;
375 else p
->p
->pings
= p
->next
;
376 if (p
->next
) p
->next
->prev
= p
->prev
;
377 if (rc
!= PING_TIMEOUT
) sel_rmtimer(&p
->t
);
378 T( trace(T_PEER
, "peer: ping 0x%08lx done (rc = %d)",
379 (unsigned long)p
->id
, rc
); )
380 if (rc
>= 0) p
->func(rc
, p
->arg
);
383 /* --- @p_pingtimeout@ --- *
385 * Arguments: @struct timeval *now@ = the time now
386 * @void *pv@ = pointer to ping block
390 * Use: Called when a ping times out.
393 static void p_pingtimeout(struct timeval
*now
, void *pv
)
397 T( trace(T_PEER
, "peer: ping 0x%08lx timed out", (unsigned long)p
->id
); )
398 p_pingdone(p
, PING_TIMEOUT
);
401 /* --- @p_pingsend@ --- *
403 * Arguments: @peer *p@ = destination peer
404 * @ping *pg@ = structure to fill in
405 * @unsigned type@ = message type
406 * @unsigned long timeout@ = how long to wait before giving up
407 * @void (*func)(int, void *)@ = callback function
408 * @void *arg@ = argument for callback
410 * Returns: Zero if successful, nonzero if it failed.
412 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
413 * if we get an answer within the timeout, or zero if no answer.
416 int p_pingsend(peer
*p
, ping
*pg
, unsigned type
,
417 unsigned long timeout
,
418 void (*func
)(int, void *), void *arg
)
426 b
= p_txstart(p
, MSG_MISC
| MISC_PING
);
431 pg
->msg
= MISC_EPONG
;
432 b
= p_txstart(p
, MSG_MISC
| MISC_EPING
);
433 buf_init(&bb
, buf_t
, sizeof(buf_t
));
434 p_pingwrite(pg
, &bb
);
436 if (ksl_encrypt(&p
->ks
, MSG_MISC
| MISC_EPING
, &bb
, b
))
452 if (p
->pings
) p
->pings
->prev
= pg
;
454 gettimeofday(&tv
, 0);
455 tv
.tv_sec
+= timeout
;
456 sel_addtimer(&sel
, &pg
->t
, &tv
, p_pingtimeout
, pg
);
457 T( trace(T_PEER
, "peer: send %s 0x%08lx to %s",
458 p_pingtype(type
), (unsigned long)pg
->id
, p
->spec
.name
); )
462 /* --- @p_greet@ --- *
464 * Arguments: @peer *p@ = peer to send to
465 * @const void *c@ = pointer to challenge
466 * @size_t sz@ = size of challenge
470 * Use: Sends a greeting packet.
473 void p_greet(peer
*p
, const void *c
, size_t sz
)
475 buf
*b
= p_txstart(p
, MSG_MISC
| MISC_GREET
);
482 * Arguments: @peer *p@ = pointer to peer block
483 * @buf *b@ = buffer containing incoming packet
487 * Use: Handles a packet which needs to be sent to a peer.
490 void p_tun(peer
*p
, buf
*b
)
492 buf
*bb
= p_txstart(p
, MSG_PACKET
);
495 if (ksl_encrypt(&p
->ks
, MSG_PACKET
, b
, bb
))
497 if (BOK(bb
) && BLEN(bb
)) {
499 p
->st
.sz_ipout
+= BLEN(bb
);
504 /* --- @p_keyreload@ --- *
510 * Use: Forces a check of the daemon's keyring files.
513 void p_keyreload(void)
518 for (p
= peers
; p
; p
= p
->next
)
523 /* --- @p_interval@ --- *
529 * Use: Called periodically to do tidying.
532 void p_interval(void)
537 for (p
= peers
; p
; p
= p
->next
)
541 /* --- @p_stats@ --- *
543 * Arguments: @peer *p@ = pointer to a peer block
545 * Returns: A pointer to the peer's statistics.
548 stats
*p_stats(peer
*p
) { return (&p
->st
); }
550 /* --- @p_ifname@ --- *
552 * Arguments: @peer *p@ = pointer to a peer block
554 * Returns: A pointer to the peer's interface name.
557 const char *p_ifname(peer
*p
) { return (p
->t
->ops
->ifname(p
->t
)); }
559 /* --- @p_addr@ --- *
561 * Arguments: @peer *p@ = pointer to a peer block
563 * Returns: A pointer to the peer's address.
566 const addr
*p_addr(peer
*p
) { return (&p
->spec
.sa
); }
568 /* --- @p_init@ --- *
570 * Arguments: @struct in_addr addr@ = address to bind to
571 * @unsigned port@ = port number to listen to
575 * Use: Initializes the peer system; creates the socket.
578 void p_init(struct in_addr addr
, unsigned port
)
581 struct sockaddr_in sin
;
584 /* --- Note on socket buffer sizes --- *
586 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
587 * sizes I pass to @setsockopt@. I'm not putting special-case code here
588 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
592 if ((fd
= socket(PF_INET
, SOCK_DGRAM
, 0)) < 0)
593 die(EXIT_FAILURE
, "socket creation failed: %s", strerror(errno
));
595 sin
.sin_family
= AF_INET
;
597 sin
.sin_port
= htons(port
);
598 if (bind(fd
, (struct sockaddr
*)&sin
, sizeof(sin
)))
599 die(EXIT_FAILURE
, "bind failed: %s", strerror(errno
));
600 if (setsockopt(fd
, SOL_SOCKET
, SO_RCVBUF
, &len
, sizeof(len
)) ||
601 setsockopt(fd
, SOL_SOCKET
, SO_SNDBUF
, &len
, sizeof(len
))) {
602 die(EXIT_FAILURE
, "failed to set socket buffer sizes: %s",
605 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
606 sel_initfile(&sel
, &sock
, fd
, SEL_READ
, p_read
, 0);
608 T( trace(T_PEER
, "peer: created socket"); )
611 /* --- @p_port@ --- *
615 * Returns: Port number used for socket.
618 unsigned p_port(void)
621 size_t sz
= sizeof(addr
);
623 if (getsockname(sock
.fd
, &a
.sa
, &sz
))
624 die(EXIT_FAILURE
, "couldn't read port number: %s", strerror(errno
));
625 assert(a
.sa
.sa_family
== AF_INET
);
626 return (ntohs(a
.sin
.sin_port
));
629 /* --- @p_keepalive@ --- *
631 * Arguments: @struct timeval *now@ = the current time
632 * @void *pv@ = peer to wake up
636 * Use: Sends a keepalive ping message to its peer.
639 static void p_keepalive(struct timeval
*now
, void *pv
)
642 p_txstart(p
, MSG_MISC
| MISC_NOP
); p_dotxend(p
);
643 T( trace(T_PEER
, "peer: sent keepalive to %s", p
->spec
.name
); )
647 /* --- @p_setkatimer@ --- *
649 * Arguments: @peer *p@ = peer to set
653 * Use: Resets the keepalive timer thing.
656 static void p_setkatimer(peer
*p
)
662 gettimeofday(&tv
, 0);
663 tv
.tv_sec
+= p
->spec
.t_ka
;
664 sel_addtimer(&sel
, &p
->tka
, &tv
, p_keepalive
, p
);
667 /* --- @p_create@ --- *
669 * Arguments: @peerspec *spec@ = information about this peer
671 * Returns: Pointer to the peer block, or null if it failed.
673 * Use: Creates a new named peer block. No peer is actually attached
677 peer
*p_create(peerspec
*spec
)
679 peer
*p
= CREATE(peer
);
681 T( trace(T_PEER
, "peer: creating new peer `%s'", spec
->name
); )
683 p
->spec
.name
= xstrdup(spec
->name
);
687 memset(&p
->st
, 0, sizeof(stats
));
688 p
->st
.t_start
= time(0);
689 if ((p
->t
= spec
->tops
->create(p
)) == 0)
692 if (kx_init(&p
->kx
, p
, &p
->ks
))
700 "%s", p
->t
->ops
->ifname(p
->t
),
701 "?ADDR", &p
->spec
.sa
,
703 a_notify("KXSTART", "?PEER", p
, A_END
);
704 /* Couldn't tell anyone before */
709 sel_rmtimer(&p
->tka
);
710 p
->t
->ops
->destroy(p
->t
);
717 /* --- @p_name@ --- *
719 * Arguments: @peer *p@ = pointer to a peer block
721 * Returns: A pointer to the peer's name.
724 const char *p_name(peer
*p
) { return (p
->spec
.name
); }
726 /* --- @p_spec@ --- *
728 * Arguments: @peer *p@ = pointer to a peer block
730 * Returns: Pointer to the peer's specification
733 const peerspec
*p_spec(peer
*p
) { return (&p
->spec
); }
735 /* --- @p_find@ --- *
737 * Arguments: @const char *name@ = name to look up
739 * Returns: Pointer to the peer block, or null if not found.
741 * Use: Finds a peer by name.
744 peer
*p_find(const char *name
)
747 for (p
= peers
; p
; p
= p
->next
) {
748 if (strcmp(name
, p
->spec
.name
) == 0)
754 /* --- @p_destroy@ --- *
756 * Arguments: @peer *p@ = pointer to a peer
760 * Use: Destroys a peer.
763 void p_destroy(peer
*p
)
767 T( trace(T_PEER
, "peer: destroying peer `%s'", p
->spec
.name
); )
768 a_notify("KILL", "%s", p
->spec
.name
, A_END
);
771 p
->t
->ops
->destroy(p
->t
);
773 sel_rmtimer(&p
->tka
);
775 for (pg
= p
->pings
; pg
; pg
= ppg
) {
777 p_pingdone(pg
, PING_PEERDIED
);
780 p
->next
->prev
= p
->prev
;
782 p
->prev
->next
= p
->next
;
788 /* --- @p_first@, @p_next@ --- *
790 * Arguments: @peer *p@ = a peer block
792 * Returns: @peer_first@ returns the first peer in some ordering;
793 * @peer_next@ returns the peer following a given one in the
794 * same ordering. Null is returned for the end of the list.
797 peer
*p_first(void) { return (peers
); }
798 peer
*p_next(peer
*p
) { return (p
->next
); }
800 /*----- That's all, folks -------------------------------------------------*/