3 * $Id: peer.c,v 1.3 2001/02/04 17:10:58 mdw Exp $
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 /*----- Revision history --------------------------------------------------*
32 * Revision 1.3 2001/02/04 17:10:58 mdw
33 * Make file descriptors be nonblocking and close-on-exec.
35 * Revision 1.2 2001/02/03 22:40:29 mdw
36 * Put timer information into the entropy pool when packets are received
37 * and on similar events. Reseed the generator on the interval timer.
39 * Revision 1.1 2001/02/03 20:26:37 mdw
44 /*----- Header files ------------------------------------------------------*/
48 /*----- Static variables --------------------------------------------------*/
50 static peer
*peers
= 0;
53 /*----- Main code ---------------------------------------------------------*/
57 * Arguments: @int fd@ = file descriptor to read from
58 * @unsigned mode@ = what happened
59 * @void *v@ = an uninteresting pointer
63 * Use: Reads a packet from somewhere.
66 static void p_read(int fd
, unsigned mode
, void *v
)
75 /* --- Read the data --- */
79 n
= recvfrom(fd
, buf_i
, sizeof(buf_i
), 0, &a
.sa
, &sz
);
81 a_warn("error reading socket: %s", strerror(errno
));
85 /* --- Find the appropriate peer --- */
87 assert(a
.sa
.sa_family
== AF_INET
);
88 for (p
= peers
; p
; p
= p
->next
) {
89 if (p
->peer
.sin
.sin_addr
.s_addr
== a
.sin
.sin_addr
.s_addr
&&
90 p
->peer
.sin
.sin_port
== a
.sin
.sin_port
)
93 a_warn("packet from unexpected peer: %s:%u",
94 inet_ntoa(a
.sin
.sin_addr
), (unsigned)ntohs(a
.sin
.sin_port
));
98 T( trace(T_PEER
, "peer: packet received from `%s'", p
->name
);
99 trace_block(T_PACKET
, "peer: packet contents", buf_i
, n
); )
101 /* --- Pick the packet apart --- */
103 buf_init(&b
, buf_i
, n
);
104 if ((ch
= buf_getbyte(&b
)) < 0) {
105 a_warn("bad packet from `%s': no type byte", p
->name
);
110 buf_init(&bb
, buf_o
, sizeof(buf_o
));
111 if (ks_decrypt(&p
->ks
, &b
, &bb
)) {
112 a_warn("couldn't decrypt inbound packet");
116 tun_inject(&p
->t
, &bb
);
118 a_warn("packet build failed");
120 case MSG_PRECHALLENGE
:
121 kx_prechallenge(&p
->kx
, &b
);
124 kx_challenge(&p
->kx
, &b
);
127 kx_response(&p
->kx
, &b
);
130 a_warn("bad packet from `%s': unknown packet type", p
->name
);
135 /* --- @p_txstart@ --- *
137 * Arguments: @peer *p@ = pointer to peer block
138 * @unsigned msg@ = message type code
140 * Returns: A pointer to a buffer to write to.
142 * Use: Starts sending to a peer. Only one send can happen at a
146 buf
*p_txstart(peer
*p
, unsigned msg
)
148 buf_init(&p
->b
, buf_o
, sizeof(buf_o
));
149 buf_putbyte(&p
->b
, msg
);
153 /* --- @p_txend@ --- *
155 * Arguments: @peer *p@ = pointer to peer block
159 * Use: Sends a packet to the peer.
162 void p_txend(peer
*p
)
165 a_warn("packet build failed");
168 IF_TRACING(T_PEER
, trace_block(T_PACKET
, "peer: sending packet",
169 BBASE(&p
->b
), BLEN(&p
->b
)); )
170 if (sendto(sock
.fd
, BBASE(&p
->b
), BLEN(&p
->b
),
171 0, &p
->peer
.sa
, p
->sasz
) < 0)
172 a_warn("packet send to `%s' failed: %s", p
->name
, strerror(errno
));
177 * Arguments: @peer *p@ = pointer to peer block
178 * @buf *b@ = buffer containing incoming packet
182 * Use: Handles a packet which needs to be sent to a peer.
185 void p_tun(peer
*p
, buf
*b
)
187 buf
*bb
= p_txstart(p
, MSG_PACKET
);
189 if (ks_encrypt(&p
->ks
, b
, bb
))
191 if (BCUR(bb
) > BBASE(bb
))
195 /* --- @p_interval@ --- *
201 * Use: Called periodically to do tidying.
204 void p_interval(void)
209 reload
= km_interval();
210 for (p
= peers
; p
; p
= pp
) {
218 /* --- @p_ifname@ --- *
220 * Arguments: @peer *p@ = pointer to a peer block
222 * Returns: A pointer to the peer's interface name.
225 const char *p_ifname(peer
*p
) { return (tun_ifname(&p
->t
)); }
227 /* --- @p_addr@ --- *
229 * Arguments: @peer *p@ = pointer to a peer block
231 * Returns: A pointer to the peer's address.
234 const addr
*p_addr(peer
*p
) { return (&p
->peer
); }
236 /* --- @p_init@ --- *
238 * Arguments: @unsigned port@ = port number to listen to
242 * Use: Initializes the peer system; creates the socket.
245 void p_init(unsigned port
)
248 struct sockaddr_in sin
;
250 if ((fd
= socket(PF_INET
, SOCK_DGRAM
, 0)) < 0)
251 die(EXIT_FAILURE
, "socket creation failed: %s", strerror(errno
));
253 sin
.sin_family
= AF_INET
;
254 sin
.sin_addr
.s_addr
= INADDR_ANY
;
255 sin
.sin_port
= htons(port
);
256 if (bind(fd
, (struct sockaddr
*)&sin
, sizeof(sin
)))
257 die(EXIT_FAILURE
, "bind failed: %s", strerror(errno
));
258 fdflags(fd
, O_NONBLOCK
, O_NONBLOCK
, FD_CLOEXEC
, FD_CLOEXEC
);
259 sel_initfile(&sel
, &sock
, fd
, SEL_READ
, p_read
, 0);
261 T( trace(T_PEER
, "peer: created socket"); )
264 /* --- @p_port@ --- *
268 * Returns: Port number used for socket.
271 unsigned p_port(void)
274 size_t sz
= sizeof(addr
);
276 if (getsockname(sock
.fd
, &a
.sa
, &sz
))
277 die(EXIT_FAILURE
, "couldn't read port number: %s", strerror(errno
));
278 assert(a
.sa
.sa_family
== AF_INET
);
279 return (ntohs(a
.sin
.sin_port
));
282 /* --- @p_create@ --- *
284 * Arguments: @const char *name@ = name for this peer
285 * @struct sockaddr *sa@ = socket address of peer
286 * @size_t sz@ = size of socket address
288 * Returns: Pointer to the peer block, or null if it failed.
290 * Use: Creates a new named peer block. No peer is actually attached
294 peer
*p_create(const char *name
, struct sockaddr
*sa
, size_t sz
)
296 peer
*p
= CREATE(peer
);
297 T( trace(T_PEER
, "peer: creating new peer `%s'", name
); )
298 p
->name
= xstrdup(name
);
301 memcpy(&p
->peer
.sa
, sa
, sz
);
303 if (kx_init(&p
->kx
, p
, &p
->ks
))
305 if (tun_create(&p
->t
, p
))
321 /* --- @p_name@ --- *
323 * Arguments: @peer *p@ = pointer to a peer block
325 * Returns: A pointer to the peer's name.
328 const char *p_name(peer
*p
) { return (p
->name
); }
330 /* --- @p_find@ --- *
332 * Arguments: @const char *name@ = name to look up
334 * Returns: Pointer to the peer block, or null if not found.
336 * Use: Finds a peer by name.
339 peer
*p_find(const char *name
)
342 for (p
= peers
; p
; p
= p
->next
) {
343 if (strcmp(name
, p
->name
) == 0)
349 /* --- @p_destroy@ --- *
351 * Arguments: @peer *p@ = pointer to a peer
355 * Use: Destroys a peer.
358 void p_destroy(peer
*p
)
360 T( trace(T_PEER
, "peer: destroying peer `%s'", p
->name
); )
366 p
->next
->prev
= p
->prev
;
368 p
->prev
->next
= p
->next
;
374 /* --- @p_first@, @p_next@ --- *
376 * Arguments: @peer *p@ = a peer block
378 * Returns: @peer_first@ returns the first peer in some ordering;
379 * @peer_next@ returns the peer following a given one in the
380 * same ordering. Null is returned for the end of the list.
383 peer
*p_first(void) { return (peers
); }
384 peer
*p_next(peer
*p
) { return (p
->next
); }
386 /*----- That's all, folks -------------------------------------------------*/