3 * $Id: peer.c,v 1.1 2001/02/03 20:26:37 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 1.1 2001/02/03 20:26:37 mdw
37 /*----- Header files ------------------------------------------------------*/
41 /*----- Static variables --------------------------------------------------*/
43 static peer
*peers
= 0;
46 /*----- Main code ---------------------------------------------------------*/
50 * Arguments: @int fd@ = file descriptor to read from
51 * @unsigned mode@ = what happened
52 * @void *v@ = an uninteresting pointer
56 * Use: Reads a packet from somewhere.
59 static void p_read(int fd
, unsigned mode
, void *v
)
68 /* --- Read the data --- */
71 n
= recvfrom(fd
, buf_i
, sizeof(buf_i
), 0, &a
.sa
, &sz
);
73 a_warn("error reading socket: %s", strerror(errno
));
77 /* --- Find the appropriate peer --- */
79 assert(a
.sa
.sa_family
== AF_INET
);
80 T( trace(T_PEER
, "packet from %s:%u",
81 inet_ntoa(a
.sin
.sin_addr
), (unsigned)ntohs(a
.sin
.sin_port
)); )
82 for (p
= peers
; p
; p
= p
->next
) {
83 T( trace(T_PEER
, "trying %s:%u",
84 inet_ntoa(p
->peer
.sin
.sin_addr
), (unsigned)ntohs(p
->peer
.sin
.sin_port
)); )
85 if (p
->peer
.sin
.sin_addr
.s_addr
== a
.sin
.sin_addr
.s_addr
&&
86 p
->peer
.sin
.sin_port
== a
.sin
.sin_port
)
89 a_warn("packet from unexpected peer: %s:%u",
90 inet_ntoa(a
.sin
.sin_addr
), (unsigned)ntohs(a
.sin
.sin_port
));
94 T( trace(T_PEER
, "peer: packet received from `%s'", p
->name
);
95 trace_block(T_PACKET
, "peer: packet contents", buf_i
, n
); )
97 /* --- Pick the packet apart --- */
99 buf_init(&b
, buf_i
, n
);
100 if ((ch
= buf_getbyte(&b
)) < 0) {
101 a_warn("bad packet from `%s': no type byte", p
->name
);
106 buf_init(&bb
, buf_o
, sizeof(buf_o
));
107 if (ks_decrypt(&p
->ks
, &b
, &bb
)) {
108 a_warn("couldn't decrypt inbound packet");
112 tun_inject(&p
->t
, &bb
);
114 a_warn("packet build failed");
116 case MSG_PRECHALLENGE
:
117 kx_prechallenge(&p
->kx
, &b
);
120 kx_challenge(&p
->kx
, &b
);
123 kx_response(&p
->kx
, &b
);
126 a_warn("bad packet from `%s': unknown packet type", p
->name
);
131 /* --- @p_txstart@ --- *
133 * Arguments: @peer *p@ = pointer to peer block
134 * @unsigned msg@ = message type code
136 * Returns: A pointer to a buffer to write to.
138 * Use: Starts sending to a peer. Only one send can happen at a
142 buf
*p_txstart(peer
*p
, unsigned msg
)
144 buf_init(&p
->b
, buf_o
, sizeof(buf_o
));
145 buf_putbyte(&p
->b
, msg
);
149 /* --- @p_txend@ --- *
151 * Arguments: @peer *p@ = pointer to peer block
155 * Use: Sends a packet to the peer.
158 void p_txend(peer
*p
)
161 a_warn("packet build failed");
164 IF_TRACING(T_PEER
, trace_block(T_PACKET
, "peer: sending packet",
165 BBASE(&p
->b
), BLEN(&p
->b
)); )
166 if (sendto(sock
.fd
, BBASE(&p
->b
), BLEN(&p
->b
),
167 0, &p
->peer
.sa
, p
->sasz
) < 0)
168 a_warn("packet send to `%s' failed: %s", p
->name
, strerror(errno
));
173 * Arguments: @peer *p@ = pointer to peer block
174 * @buf *b@ = buffer containing incoming packet
178 * Use: Handles a packet which needs to be sent to a peer.
181 void p_tun(peer
*p
, buf
*b
)
183 buf
*bb
= p_txstart(p
, MSG_PACKET
);
184 if (ks_encrypt(&p
->ks
, b
, bb
))
186 if (BCUR(bb
) > BBASE(bb
))
190 /* --- @p_interval@ --- *
196 * Use: Called periodically to do tidying.
199 void p_interval(void)
204 reload
= km_interval();
205 for (p
= peers
; p
; p
= pp
) {
213 /* --- @p_ifname@ --- *
215 * Arguments: @peer *p@ = pointer to a peer block
217 * Returns: A pointer to the peer's interface name.
220 const char *p_ifname(peer
*p
) { return (tun_ifname(&p
->t
)); }
222 /* --- @p_addr@ --- *
224 * Arguments: @peer *p@ = pointer to a peer block
226 * Returns: A pointer to the peer's address.
229 const addr
*p_addr(peer
*p
) { return (&p
->peer
); }
231 /* --- @p_init@ --- *
233 * Arguments: @unsigned port@ = port number to listen to
237 * Use: Initializes the peer system; creates the socket.
240 void p_init(unsigned port
)
243 struct sockaddr_in sin
;
245 if ((fd
= socket(PF_INET
, SOCK_DGRAM
, 0)) < 0)
246 die(EXIT_FAILURE
, "socket creation failed: %s", strerror(errno
));
248 sin
.sin_family
= AF_INET
;
249 sin
.sin_addr
.s_addr
= INADDR_ANY
;
250 sin
.sin_port
= htons(port
);
251 if (bind(fd
, (struct sockaddr
*)&sin
, sizeof(sin
)))
252 die(EXIT_FAILURE
, "bind failed: %s", strerror(errno
));
253 sel_initfile(&sel
, &sock
, fd
, SEL_READ
, p_read
, 0);
255 T( trace(T_PEER
, "peer: created socket"); )
258 /* --- @p_port@ --- *
262 * Returns: Port number used for socket.
265 unsigned p_port(void)
268 size_t sz
= sizeof(addr
);
270 if (getsockname(sock
.fd
, &a
.sa
, &sz
))
271 die(EXIT_FAILURE
, "couldn't read port number: %s", strerror(errno
));
272 assert(a
.sa
.sa_family
== AF_INET
);
273 return (ntohs(a
.sin
.sin_port
));
276 /* --- @p_create@ --- *
278 * Arguments: @const char *name@ = name for this peer
279 * @struct sockaddr *sa@ = socket address of peer
280 * @size_t sz@ = size of socket address
282 * Returns: Pointer to the peer block, or null if it failed.
284 * Use: Creates a new named peer block. No peer is actually attached
288 peer
*p_create(const char *name
, struct sockaddr
*sa
, size_t sz
)
290 peer
*p
= CREATE(peer
);
291 T( trace(T_PEER
, "peer: creating new peer `%s'", name
); )
292 p
->name
= xstrdup(name
);
295 memcpy(&p
->peer
.sa
, sa
, sz
);
297 if (kx_init(&p
->kx
, p
, &p
->ks
))
299 if (tun_create(&p
->t
, p
))
315 /* --- @p_name@ --- *
317 * Arguments: @peer *p@ = pointer to a peer block
319 * Returns: A pointer to the peer's name.
322 const char *p_name(peer
*p
) { return (p
->name
); }
324 /* --- @p_find@ --- *
326 * Arguments: @const char *name@ = name to look up
328 * Returns: Pointer to the peer block, or null if not found.
330 * Use: Finds a peer by name.
333 peer
*p_find(const char *name
)
336 for (p
= peers
; p
; p
= p
->next
) {
337 if (strcmp(name
, p
->name
) == 0)
343 /* --- @p_destroy@ --- *
345 * Arguments: @peer *p@ = pointer to a peer
349 * Use: Destroys a peer.
352 void p_destroy(peer
*p
)
354 T( trace(T_PEER
, "peer: destroying peer `%s'", p
->name
); )
360 p
->next
->prev
= p
->prev
;
362 p
->prev
->next
= p
->next
;
368 /* --- @p_first@, @p_next@ --- *
370 * Arguments: @peer *p@ = a peer block
372 * Returns: @peer_first@ returns the first peer in some ordering;
373 * @peer_next@ returns the peer following a given one in the
374 * same ordering. Null is returned for the end of the list.
377 peer
*p_first(void) { return (peers
); }
378 peer
*p_next(peer
*p
) { return (p
->next
); }
380 /*----- That's all, folks -------------------------------------------------*/