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 -------------------------------------------------*/