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 /*----- Main code ---------------------------------------------------------*/
42 * Arguments: @int fd@ = file descriptor to read from
43 * @unsigned mode@ = what happened
44 * @void *v@ = an uninteresting pointer
48 * Use: Reads a packet from somewhere.
51 static void p_read(int fd, unsigned mode, void *v)
60 /* --- Read the data --- */
64 n = recvfrom(fd, buf_i, sizeof(buf_i), 0, &a.sa, &sz);
66 a_warn("PEER - socket-read-error -- %s", strerror(errno));
70 /* --- Find the appropriate peer --- */
72 assert(a.sa.sa_family == AF_INET);
73 for (p = peers; p; p = p->next) {
74 if (p->peer.sin.sin_addr.s_addr == a.sin.sin_addr.s_addr &&
75 p->peer.sin.sin_port == a.sin.sin_port)
78 a_warn("PEER - unexpected-source INET %s %u",
79 inet_ntoa(a.sin.sin_addr), (unsigned)ntohs(a.sin.sin_port));
84 trace(T_PEER, "peer: packet received from `%s'", p->name);
85 trace_block(T_PACKET, "peer: packet contents", buf_i, n);
88 /* --- Pick the packet apart --- */
90 p->st.t_last = time(0);
93 buf_init(&b, buf_i, n);
94 if ((ch = buf_getbyte(&b)) < 0) {
95 a_warn("PEER %s bad-packet no-type", p->name);
98 switch (ch & MSG_CATMASK) {
100 if (ch & MSG_TYPEMASK) {
101 a_warn("PEER %s bad-packet unknown-type 0x%02x", p->name, ch);
105 buf_init(&bb, buf_o, sizeof(buf_o));
106 if (ksl_decrypt(&p->ks, MSG_PACKET, &b, &bb)) {
108 a_warn("PEER %s decrypt-failed", p->name);
113 p->st.sz_ipin += BSZ(&b);
114 tun_inject(&p->t, &bb);
117 a_warn("PEER %s packet-build-failed", p->name);
121 kx_message(&p->kx, ch & MSG_TYPEMASK, &b);
125 a_warn("PEER %s bad-packet unknown-category 0x%02x", p->name, ch);
130 /* --- @p_txstart@ --- *
132 * Arguments: @peer *p@ = pointer to peer block
133 * @unsigned msg@ = message type code
135 * Returns: A pointer to a buffer to write to.
137 * Use: Starts sending to a peer. Only one send can happen at a
141 buf *p_txstart(peer *p, unsigned msg)
143 buf_init(&p->b, buf_o, sizeof(buf_o));
144 buf_putbyte(&p->b, msg);
148 /* --- @p_txend@ --- *
150 * Arguments: @peer *p@ = pointer to peer block
154 * Use: Sends a packet to the peer.
157 void p_txend(peer *p)
160 a_warn("PEER %s packet-build-failed", p->name);
163 IF_TRACING(T_PEER, trace_block(T_PACKET, "peer: sending packet",
164 BBASE(&p->b), BLEN(&p->b)); )
165 if (sendto(sock.fd, BBASE(&p->b), BLEN(&p->b),
166 0, &p->peer.sa, p->sasz) < 0)
167 a_warn("PEER %s socket-write-error -- %s", p->name, strerror(errno));
170 p->st.sz_out += BLEN(&p->b);
176 * Arguments: @peer *p@ = pointer to peer block
177 * @buf *b@ = buffer containing incoming packet
181 * Use: Handles a packet which needs to be sent to a peer.
184 void p_tun(peer *p, buf *b)
186 buf *bb = p_txstart(p, MSG_PACKET);
189 if (ksl_encrypt(&p->ks, MSG_PACKET, b, bb))
191 if (BOK(bb) && BLEN(bb)) {
193 p->st.sz_ipout += BLEN(bb);
198 /* --- @p_interval@ --- *
204 * Use: Called periodically to do tidying.
207 void p_interval(void)
212 reload = km_interval();
213 for (p = peers; p; p = pp) {
221 /* --- @p_stats@ --- *
223 * Arguments: @peer *p@ = pointer to a peer block
225 * Returns: A pointer to the peer's statistics.
228 stats *p_stats(peer *p) { return (&p->st); }
230 /* --- @p_ifname@ --- *
232 * Arguments: @peer *p@ = pointer to a peer block
234 * Returns: A pointer to the peer's interface name.
237 const char *p_ifname(peer *p) { return (tun_ifname(&p->t)); }
239 /* --- @p_addr@ --- *
241 * Arguments: @peer *p@ = pointer to a peer block
243 * Returns: A pointer to the peer's address.
246 const addr *p_addr(peer *p) { return (&p->peer); }
248 /* --- @p_init@ --- *
250 * Arguments: @struct in_addr addr@ = address to bind to
251 * @unsigned port@ = port number to listen to
255 * Use: Initializes the peer system; creates the socket.
258 void p_init(struct in_addr addr, unsigned port)
261 struct sockaddr_in sin;
264 /* --- Note on socket buffer sizes --- *
266 * For some bizarre reason, Linux 2.2 (at least) doubles the socket buffer
267 * sizes I pass to @setsockopt@. I'm not putting special-case code here
268 * for Linux: BSD (at least TCPv2) does what I tell it rather than second-
272 if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
273 die(EXIT_FAILURE, "socket creation failed: %s", strerror(errno));
275 sin.sin_family = AF_INET;
277 sin.sin_port = htons(port);
278 if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
279 die(EXIT_FAILURE, "bind failed: %s", strerror(errno));
280 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
281 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len))) {
282 die(EXIT_FAILURE, "failed to set socket buffer sizes: %s",
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))
340 switch (p->peer.sa.sa_family) {
342 a_notify("ADD %s INET %s %u",
344 inet_ntoa(p->peer.sin.sin_addr),
345 (unsigned)ntohs(p->peer.sin.sin_port));
348 a_notify("ADD %s UNKNOWN", name);
351 a_notify("KXSTART %s", name); /* Couldn't tell anyone before */
362 /* --- @p_name@ --- *
364 * Arguments: @peer *p@ = pointer to a peer block
366 * Returns: A pointer to the peer's name.
369 const char *p_name(peer *p) { return (p->name); }
371 /* --- @p_find@ --- *
373 * Arguments: @const char *name@ = name to look up
375 * Returns: Pointer to the peer block, or null if not found.
377 * Use: Finds a peer by name.
380 peer *p_find(const char *name)
383 for (p = peers; p; p = p->next) {
384 if (strcmp(name, p->name) == 0)
390 /* --- @p_destroy@ --- *
392 * Arguments: @peer *p@ = pointer to a peer
396 * Use: Destroys a peer.
399 void p_destroy(peer *p)
401 T( trace(T_PEER, "peer: destroying peer `%s'", p->name); )
402 a_notify("KILL %s", p->name);
408 p->next->prev = p->prev;
410 p->prev->next = p->next;
416 /* --- @p_first@, @p_next@ --- *
418 * Arguments: @peer *p@ = a peer block
420 * Returns: @peer_first@ returns the first peer in some ordering;
421 * @peer_next@ returns the peer following a given one in the
422 * same ordering. Null is returned for the end of the list.
425 peer *p_first(void) { return (peers); }
426 peer *p_next(peer *p) { return (p->next); }
428 /*----- That's all, folks -------------------------------------------------*/