2 * demand.c - Support routines for demand-dialling.
4 * Copyright (c) 1996-2002 Paul Mackerras. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
18 * 3. The name(s) of the authors of this software must not be used to
19 * endorse or promote products derived from this software without
20 * prior written permission.
22 * 4. Redistributions of any form whatsoever must retain the following
24 * "This product includes software developed by Paul Mackerras
25 * <paulus@samba.org>".
27 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
28 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
29 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
30 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
32 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
33 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
36 #define RCSID "$Id: demand.c,v 1.17 2003/03/03 05:11:45 paulus Exp $"
44 #include <sys/param.h>
45 #include <sys/types.h>
48 #include <sys/resource.h>
50 #include <sys/socket.h>
62 static const char rcsid[] = RCSID;
74 unsigned char data[1];
77 struct packet *pend_q;
78 struct packet *pend_qtail;
80 static int active_packet __P((unsigned char *, int));
83 * demand_conf - configure the interface for doing dial-on-demand.
89 struct protent *protp;
91 /* framemax = lcp_allowoptions[0].mru;
92 if (framemax < PPP_MRU) */
94 framemax += PPP_HDRLEN + PPP_FCSLEN;
95 frame = malloc(framemax);
104 netif_set_mtu(0, MIN(lcp_allowoptions[0].mru, PPP_MRU));
105 if (ppp_send_config(0, PPP_MRU, (u_int32_t) 0, 0, 0) < 0
106 || ppp_recv_config(0, PPP_MRU, (u_int32_t) 0, 0, 0) < 0)
107 fatal("Couldn't set up demand-dialled PPP interface: %m");
110 set_filters(&pass_filter, &active_filter);
114 * Call the demand_conf procedure for each protocol that's got one.
116 for (i = 0; (protp = protocols[i]) != NULL; ++i)
117 if (protp->enabled_flag && protp->demand_conf != NULL)
118 if (!((*protp->demand_conf)(0)))
124 * demand_block - set each network protocol to block further packets.
130 struct protent *protp;
132 for (i = 0; (protp = protocols[i]) != NULL; ++i)
133 if (protp->enabled_flag && protp->demand_conf != NULL)
134 sifnpmode(0, protp->protocol & ~0x8000, NPMODE_QUEUE);
139 * demand_discard - set each network protocol to discard packets
145 struct packet *pkt, *nextpkt;
147 struct protent *protp;
149 for (i = 0; (protp = protocols[i]) != NULL; ++i)
150 if (protp->enabled_flag && protp->demand_conf != NULL)
151 sifnpmode(0, protp->protocol & ~0x8000, NPMODE_ERROR);
154 /* discard all saved packets */
155 for (pkt = pend_q; pkt != NULL; pkt = nextpkt) {
167 * demand_unblock - set each enabled network protocol to pass packets.
173 struct protent *protp;
175 for (i = 0; (protp = protocols[i]) != NULL; ++i)
176 if (protp->enabled_flag && protp->demand_conf != NULL)
177 sifnpmode(0, protp->protocol & ~0x8000, NPMODE_PASS);
181 * FCS lookup table as calculated by genfcstab.
183 static u_short fcstab[256] = {
184 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
185 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
186 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
187 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
188 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
189 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
190 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
191 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
192 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
193 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
194 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
195 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
196 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
197 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
198 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
199 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
200 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
201 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
202 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
203 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
204 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
205 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
206 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
207 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
208 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
209 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
210 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
211 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
212 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
213 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
214 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
215 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
219 * loop_chars - process characters received from the loopback.
220 * Calls loop_frame when a complete frame has been accumulated.
221 * Return value is 1 if we need to bring up the link, 0 otherwise.
234 if (!escape_flag && !flush_flag
235 && framelen > 2 && fcs == PPP_GOODFCS) {
237 if (loop_frame((unsigned char *)frame, framelen))
251 } else if (c == PPP_ESCAPE) {
255 if (framelen >= framemax) {
259 frame[framelen++] = c;
260 fcs = PPP_FCS(fcs, c);
266 * loop_frame - given a frame obtained from the loopback,
267 * decide whether to bring up the link or not, and, if we want
268 * to transmit this frame later, put it on the pending queue.
269 * Return value is 1 if we need to bring up the link, 0 otherwise.
270 * We assume that the kernel driver has already applied the
271 * pass_filter, so we won't get packets it rejected.
272 * We apply the active_filter to see if we want this packet to
276 loop_frame(frame, len)
277 unsigned char *frame;
282 /* dbglog("from loop: %P", frame, len); */
283 if (len < PPP_HDRLEN)
285 if ((PPP_PROTOCOL(frame) & 0x8000) != 0)
286 return 0; /* shouldn't get any of these anyway */
287 if (!active_packet(frame, len))
290 pkt = (struct packet *) malloc(sizeof(struct packet) + len);
294 memcpy(pkt->data, frame, len);
298 pend_qtail->next = pkt;
305 * demand_rexmit - Resend all those frames which we got via the
306 * loopback, now that the real serial link is up.
312 struct packet *pkt, *prev, *nextpkt;
317 for (; pkt != NULL; pkt = nextpkt) {
319 if (PPP_PROTOCOL(pkt->data) == proto) {
320 output(0, pkt->data, pkt->length);
336 * Scan a packet to decide whether it is an "active" packet,
337 * that is, whether it is worth bringing up the link for.
340 active_packet(p, len)
345 struct protent *protp;
347 if (len < PPP_HDRLEN)
349 proto = PPP_PROTOCOL(p);
351 if (pass_filter.bf_len != 0
352 && bpf_filter(pass_filter.bf_insns, p, len, len) == 0)
354 if (active_filter.bf_len != 0
355 && bpf_filter(active_filter.bf_insns, p, len, len) == 0)
358 for (i = 0; (protp = protocols[i]) != NULL; ++i) {
359 if (protp->protocol < 0xC000 && (protp->protocol & ~0x8000) == proto) {
360 if (!protp->enabled_flag)
362 if (protp->active_pkt == NULL)
364 return (*protp->active_pkt)(p, len);
367 return 0; /* not a supported protocol !!?? */