3 * $Id: peer.c,v 1.4 2001/02/16 21:40:24 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 1.4 2001/02/16 21:40:24 mdw
33 * Change key exchange message interface. Maintain statistics.
35 * Revision 1.3 2001/02/04 17:10:58 mdw
36 * Make file descriptors be nonblocking and close-on-exec.
38 * Revision 1.2 2001/02/03 22:40:29 mdw
39 * Put timer information into the entropy pool when packets are received
40 * and on similar events. Reseed the generator on the interval timer.
42 * Revision 1.1 2001/02/03 20:26:37 mdw
47 /*----- Header files ------------------------------------------------------*/
51 /*----- Static variables --------------------------------------------------*/
53 static peer *peers = 0;
56 /*----- Main code ---------------------------------------------------------*/
60 * Arguments: @int fd@ = file descriptor to read from
61 * @unsigned mode@ = what happened
62 * @void *v@ = an uninteresting pointer
66 * Use: Reads a packet from somewhere.
69 static void p_read(int fd, unsigned mode, void *v)
78 /* --- Read the data --- */
82 n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
84 a_warn("error reading socket: %s", strerror(errno));
88 /* --- Find the appropriate peer --- */
90 assert(a.sa.sa_family == AF_INET);
91 for (p = peers; p; p = p->next) {
92 if (p->peer.sin.sin_addr.s_addr == a.sin.sin_addr.s_addr &&
93 p->peer.sin.sin_port == a.sin.sin_port)
96 a_warn("packet from unexpected peer: %s:%u",
97 inet_ntoa(a.sin.sin_addr), (unsigned)ntohs(a.sin.sin_port));
101 T( trace(T_PEER, "peer: packet received from `%s'", p->name);
102 trace_block(T_PACKET, "peer: packet contents", buf_i, n); )
104 /* --- Pick the packet apart --- */
106 p->st.t_last = time(0);
109 buf_init(&b, buf_i, n);
110 if ((ch = buf_getbyte(&b)) < 0) {
111 a_warn("bad packet from `%s': no type byte", p->name);
114 switch (ch & MSG_CATMASK) {
116 if (ch & MSG_TYPEMASK) {
117 a_warn("unknown packet type from `%s'", p->name);
121 buf_init(&bb, buf_o, sizeof(buf_o));
122 if (ksl_decrypt(&p->ks, &b, &bb)) {
124 a_warn("couldn't decrypt inbound packet from `%s'", p->name);
129 p->st.sz_ipin += BSZ(&b);
130 tun_inject(&p->t, &bb);
133 a_warn("packet build failed");
137 kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
141 a_warn("bad packet from `%s': unknown packet type", p->name);
146 /* --- @p_txstart@ --- *
148 * Arguments: @peer *p@ = pointer to peer block
149 * @unsigned msg@ = message type code
151 * Returns: A pointer to a buffer to write to.
153 * Use: Starts sending to a peer. Only one send can happen at a
157 buf *p_txstart(peer *p, unsigned msg)
159 buf_init(&p->b, buf_o, sizeof(buf_o));
160 buf_putbyte(&p->b, msg);
164 /* --- @p_txend@ --- *
166 * Arguments: @peer *p@ = pointer to peer block
170 * Use: Sends a packet to the peer.
173 void p_txend(peer *p)
176 a_warn("packet build failed");
179 IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
180 BBASE(&p->b), BLEN(&p->b)); )
181 if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b),
182 0, &p->peer.sa, p->sasz) < 0)
183 a_warn("packet send to `%s' failed: %s", p->name, strerror(errno));
186 p->st.sz_out += BLEN(&p->b);
192 * Arguments: @peer *p@ = pointer to peer block
193 * @buf *b@ = buffer containing incoming packet
197 * Use: Handles a packet which needs to be sent to a peer.
200 void p_tun(peer *p, buf *b)
202 buf *bb = p_txstart(p, MSG_PACKET);
204 if (ksl_encrypt(&p->ks, b, bb))
206 if (BOK(bb) && BLEN(bb)) {
208 p->st.sz_ipout += BLEN(bb);
213 /* --- @p_interval@ --- *
219 * Use: Called periodically to do tidying.
222 void p_interval(void)
227 reload = km_interval();
228 for (p = peers; p; p = pp) {
236 /* --- @p_stats@ --- *
238 * Arguments: @peer *p@ = pointer to a peer block
240 * Returns: A pointer to the peer's statistics.
243 stats *p_stats(peer *p) { return (&p->st); }
245 /* --- @p_ifname@ --- *
247 * Arguments: @peer *p@ = pointer to a peer block
249 * Returns: A pointer to the peer's interface name.
252 const char *p_ifname(peer *p) { return (tun_ifname(&p->t)); }
254 /* --- @p_addr@ --- *
256 * Arguments: @peer *p@ = pointer to a peer block
258 * Returns: A pointer to the peer's address.
261 const addr *p_addr(peer *p) { return (&p->peer); }
263 /* --- @p_init@ --- *
265 * Arguments: @unsigned port@ = port number to listen to
269 * Use: Initializes the peer system; creates the socket.
272 void p_init(unsigned port)
275 struct sockaddr_in sin;
277 if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
278 die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
280 sin.sin_family = AF_INET;
281 sin.sin_addr.s_addr = INADDR_ANY;
282 sin.sin_port = htons(port);
283 if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
284 die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
285 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
286 sel_initfile(&sel, &sock, fd, SEL_READ, p_read, 0);
288 T( trace(T_PEER, "peer: created socket"); )
291 /* --- @p_port@ --- *
295 * Returns: Port number used for socket.
298 unsigned p_port(void)
301 size_t sz = sizeof(addr);
303 if (getsockname(sock.fd, &a.sa, &sz))
304 die(EXIT_FAILURE, "couldn't read port number: %s", strerror(errno));
305 assert(a.sa.sa_family == AF_INET);
306 return (ntohs(a.sin.sin_port));
309 /* --- @p_create@ --- *
311 * Arguments: @const char *name@ = name for this peer
312 * @struct sockaddr *sa@ = socket address of peer
313 * @size_t sz@ = size of socket address
315 * Returns: Pointer to the peer block, or null if it failed.
317 * Use: Creates a new named peer block. No peer is actually attached
321 peer *p_create(const char *name, struct sockaddr *sa, size_t sz)
323 peer *p = CREATE(peer);
324 T( trace(T_PEER, "peer: creating new peer `%s'", name); )
325 p->name = xstrdup(name);
328 memcpy(&p->peer.sa, sa, sz);
330 memset(&p->st, 0, sizeof(stats));
331 p->st.t_start = time(0);
332 if (kx_init(&p->kx, p, &p->ks))
334 if (tun_create(&p->t, p))
350 /* --- @p_name@ --- *
352 * Arguments: @peer *p@ = pointer to a peer block
354 * Returns: A pointer to the peer's name.
357 const char *p_name(peer *p) { return (p->name); }
359 /* --- @p_find@ --- *
361 * Arguments: @const char *name@ = name to look up
363 * Returns: Pointer to the peer block, or null if not found.
365 * Use: Finds a peer by name.
368 peer *p_find(const char *name)
371 for (p = peers; p; p = p->next) {
372 if (strcmp(name, p->name) == 0)
378 /* --- @p_destroy@ --- *
380 * Arguments: @peer *p@ = pointer to a peer
384 * Use: Destroys a peer.
387 void p_destroy(peer *p)
389 T( trace(T_PEER, "peer: destroying peer `%s'", p->name); )
395 p->next->prev = p->prev;
397 p->prev->next = p->next;
403 /* --- @p_first@, @p_next@ --- *
405 * Arguments: @peer *p@ = a peer block
407 * Returns: @peer_first@ returns the first peer in some ordering;
408 * @peer_next@ returns the peer following a given one in the
409 * same ordering. Null is returned for the end of the list.
412 peer *p_first(void) { return (peers); }
413 peer *p_next(peer *p) { return (p->next); }
415 /*----- That's all, folks -------------------------------------------------*/