1/*
2 * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23/*
24 * multilink.c - support routines for multilink.
25 *
26 * Copyright (c) 2000-2002 Paul Mackerras. All rights reserved.
27 *
28 * Redistribution and use in source and binary forms, with or without
29 * modification, are permitted provided that the following conditions
30 * are met:
31 *
32 * 1. Redistributions of source code must retain the above copyright
33 *    notice, this list of conditions and the following disclaimer.
34 *
35 * 2. Redistributions in binary form must reproduce the above copyright
36 *    notice, this list of conditions and the following disclaimer in
37 *    the documentation and/or other materials provided with the
38 *    distribution.
39 *
40 * 3. The name(s) of the authors of this software must not be used to
41 *    endorse or promote products derived from this software without
42 *    prior written permission.
43 *
44 * 4. Redistributions of any form whatsoever must retain the following
45 *    acknowledgment:
46 *    "This product includes software developed by Paul Mackerras
47 *     <paulus@samba.org>".
48 *
49 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
50 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
51 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
52 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
53 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
54 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
55 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
56 */
57#include <string.h>
58#include <ctype.h>
59#include <stdlib.h>
60#include <netdb.h>
61#include <errno.h>
62#include <signal.h>
63#include <netinet/in.h>
64
65#include "pppd.h"
66#include "fsm.h"
67#include "lcp.h"
68#include "tdb.h"
69
70bool endpoint_specified;	/* user gave explicit endpoint discriminator */
71char *bundle_id;		/* identifier for our bundle */
72
73extern TDB_CONTEXT *pppdb;
74extern char db_key[];
75
76static int get_default_epdisc __P((struct epdisc *));
77static int parse_num __P((char *str, const char *key, int *valp));
78static int owns_unit __P((TDB_DATA pid, int unit));
79
80#define set_ip_epdisc(ep, addr) do {	\
81	ep->length = 4;			\
82	ep->value[0] = addr >> 24;	\
83	ep->value[1] = addr >> 16;	\
84	ep->value[2] = addr >> 8;	\
85	ep->value[3] = addr;		\
86} while (0)
87
88#define LOCAL_IP_ADDR(addr)						  \
89	(((addr) & 0xff000000) == 0x0a000000		/* 10.x.x.x */	  \
90	 || ((addr) & 0xfff00000) == 0xac100000		/* 172.16.x.x */  \
91	 || ((addr) & 0xffff0000) == 0xc0a80000)	/* 192.168.x.x */
92
93#define process_exists(n)	(kill((n), 0) == 0 || errno != ESRCH)
94
95void
96mp_check_options()
97{
98	lcp_options *wo = &lcp_wantoptions[0];
99	lcp_options *ao = &lcp_allowoptions[0];
100
101	if (!multilink)
102		return;
103	/* if we're doing multilink, we have to negotiate MRRU */
104	if (!wo->neg_mrru) {
105		/* mrru not specified, default to mru */
106		wo->mrru = wo->mru;
107		wo->neg_mrru = 1;
108	}
109	ao->mrru = ao->mru;
110	ao->neg_mrru = 1;
111
112	if (!wo->neg_endpoint && !noendpoint) {
113		/* get a default endpoint value */
114		wo->neg_endpoint = get_default_epdisc(&wo->endpoint);
115	}
116}
117
118/*
119 * Make a new bundle or join us to an existing bundle
120 * if we are doing multilink.
121 */
122int
123mp_join_bundle()
124{
125	lcp_options *go = &lcp_gotoptions[0];
126	lcp_options *ho = &lcp_hisoptions[0];
127	lcp_options *ao = &lcp_allowoptions[0];
128	int unit, pppd_pid;
129	int l, mtu;
130	char *p;
131	TDB_DATA key, pid, rec;
132
133	if (!go->neg_mrru || !ho->neg_mrru) {
134		/* not doing multilink */
135		if (go->neg_mrru)
136			notice("oops, multilink negotiated only for receive");
137		mtu = ho->neg_mru? ho->mru: PPP_MRU;
138		if (mtu > ao->mru)
139			mtu = ao->mru;
140		if (demand) {
141			/* already have a bundle */
142			cfg_bundle(0, 0, 0, 0);
143			netif_set_mtu(0, mtu);
144			return 0;
145		}
146		make_new_bundle(0, 0, 0, 0);
147		set_ifunit(1);
148		netif_set_mtu(0, mtu);
149		return 0;
150	}
151
152	/*
153	 * Find the appropriate bundle or join a new one.
154	 * First we make up a name for the bundle.
155	 * The length estimate is worst-case assuming every
156	 * character has to be quoted.
157	 */
158	l = 4 * strlen(peer_authname) + 10;
159	if (ho->neg_endpoint)
160		l += 3 * ho->endpoint.length + 8;
161	if (bundle_name)
162		l += 3 * strlen(bundle_name) + 2;
163	bundle_id = malloc(l);
164	if (bundle_id == 0)
165		novm("bundle identifier");
166
167	p = bundle_id;
168	p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
169	if (ho->neg_endpoint || bundle_name)
170		*p++ = '/';
171	if (ho->neg_endpoint)
172		p += slprintf(p, bundle_id+l-p, "%s",
173			      epdisc_to_str(&ho->endpoint));
174	if (bundle_name)
175		p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
176
177	/*
178	 * For demand mode, we only need to configure the bundle
179	 * and attach the link.
180	 */
181	mtu = MIN(ho->mrru, ao->mru);
182	if (demand) {
183		cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
184		netif_set_mtu(0, mtu);
185		script_setenv("BUNDLE", bundle_id + 7, 1);
186		return 0;
187	}
188
189	/*
190	 * Check if the bundle ID is already in the database.
191	 */
192	unit = -1;
193	tdb_writelock(pppdb);
194	key.dptr = bundle_id;
195	key.dsize = p - bundle_id;
196	pid = tdb_fetch(pppdb, key);
197	if (pid.dptr != NULL) {
198		/* bundle ID exists, see if the pppd record exists */
199		rec = tdb_fetch(pppdb, pid);
200		if (rec.dptr != NULL) {
201			/* it is, parse the interface number */
202			parse_num(rec.dptr, "IFNAME=ppp", &unit);
203			/* check the pid value */
204			if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
205			    || !process_exists(pppd_pid)
206			    || !owns_unit(pid, unit))
207				unit = -1;
208			free(rec.dptr);
209		}
210		free(pid.dptr);
211	}
212
213	if (unit >= 0) {
214		/* attach to existing unit */
215		if (bundle_attach(unit)) {
216			set_ifunit(0);
217			script_setenv("BUNDLE", bundle_id + 7, 0);
218			tdb_writeunlock(pppdb);
219			info("Link attached to %s", ifname);
220			return 1;
221		}
222		/* attach failed because bundle doesn't exist */
223	}
224
225	/* we have to make a new bundle */
226	make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
227	set_ifunit(1);
228	netif_set_mtu(0, mtu);
229	script_setenv("BUNDLE", bundle_id + 7, 1);
230	tdb_writeunlock(pppdb);
231	info("New bundle %s created", ifname);
232	return 0;
233}
234
235static int
236parse_num(str, key, valp)
237     char *str;
238     const char *key;
239     int *valp;
240{
241	char *p, *endp;
242	int i;
243
244	p = strstr(str, key);
245	if (p != 0) {
246		p += strlen(key);
247		i = strtol(p, &endp, 10);
248		if (endp != p && (*endp == 0 || *endp == ';')) {
249			*valp = i;
250			return 1;
251		}
252	}
253	return 0;
254}
255
256/*
257 * Check whether the pppd identified by `key' still owns ppp unit `unit'.
258 */
259static int
260owns_unit(key, unit)
261     TDB_DATA key;
262     int unit;
263{
264	char ifkey[32];
265	TDB_DATA kd, vd;
266	int ret = 0;
267
268	slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
269	kd.dptr = ifkey;
270	kd.dsize = strlen(ifkey);
271	vd = tdb_fetch(pppdb, kd);
272	if (vd.dptr != NULL) {
273		ret = vd.dsize == key.dsize
274			&& memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
275		free(vd.dptr);
276	}
277	return ret;
278}
279
280static int
281get_default_epdisc(ep)
282     struct epdisc *ep;
283{
284	char *p;
285	struct hostent *hp;
286	u_int32_t addr;
287
288	/* First try for an ethernet MAC address */
289	p = get_first_ethernet();
290	if (p != 0 && get_if_hwaddr(ep->value, p) >= 0) {
291		ep->class = EPD_MAC;
292		ep->length = 6;
293		return 1;
294	}
295
296	/* see if our hostname corresponds to a reasonable IP address */
297	hp = gethostbyname(hostname);
298	if (hp != NULL) {
299		addr = *(u_int32_t *)hp->h_addr;
300		if (!bad_ip_adrs(addr)) {
301			addr = ntohl(addr);
302			if (!LOCAL_IP_ADDR(addr)) {
303				ep->class = EPD_IP;
304				set_ip_epdisc(ep, addr);
305				return 1;
306			}
307		}
308	}
309
310	return 0;
311}
312
313/*
314 * epdisc_to_str - make a printable string from an endpoint discriminator.
315 */
316
317static char *endp_class_names[] = {
318    "null", "local", "IP", "MAC", "magic", "phone"
319};
320
321char *
322epdisc_to_str(ep)
323     struct epdisc *ep;
324{
325	static char str[MAX_ENDP_LEN*3+8];
326	u_char *p = ep->value;
327	int i, mask = 0;
328	char *q, c, c2;
329
330	if (ep->class == EPD_NULL && ep->length == 0)
331		return "null";
332	if (ep->class == EPD_IP && ep->length == 4) {
333		u_int32_t addr;
334
335		GETLONG(addr, p);
336		slprintf(str, sizeof(str), "IP:%I", htonl(addr));
337		return str;
338	}
339
340	c = ':';
341	c2 = '.';
342	if (ep->class == EPD_MAC && ep->length == 6)
343		c2 = ':';
344	else if (ep->class == EPD_MAGIC && (ep->length % 4) == 0)
345		mask = 3;
346	q = str;
347	if (ep->class <= EPD_PHONENUM)
348		q += slprintf(q, sizeof(str)-1, "%s",
349			      endp_class_names[ep->class]);
350	else
351		q += slprintf(q, sizeof(str)-1, "%d", ep->class);
352	c = ':';
353	for (i = 0; i < ep->length && i < MAX_ENDP_LEN; ++i) {
354		if ((i & mask) == 0) {
355			*q++ = c;
356			c = c2;
357		}
358		q += slprintf(q, str + sizeof(str) - q, "%.2x", ep->value[i]);
359	}
360	return str;
361}
362
363static int hexc_val(int c)
364{
365	if (c >= 'a')
366		return c - 'a' + 10;
367	if (c >= 'A')
368		return c - 'A' + 10;
369	return c - '0';
370}
371
372int
373str_to_epdisc(ep, str)
374     struct epdisc *ep;
375     char *str;
376{
377	int i, l;
378	char *p, *endp;
379
380	for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
381		int sl = strlen(endp_class_names[i]);
382		if (strncasecmp(str, endp_class_names[i], sl) == 0) {
383			str += sl;
384			break;
385		}
386	}
387	if (i > EPD_PHONENUM) {
388		/* not a class name, try a decimal class number */
389		i = strtol(str, &endp, 10);
390		if (endp == str)
391			return 0;	/* can't parse class number */
392		str = endp;
393	}
394	ep->class = i;
395	if (*str == 0) {
396		ep->length = 0;
397		return 1;
398	}
399	if (*str != ':' && *str != '.')
400		return 0;
401	++str;
402
403	if (i == EPD_IP) {
404		u_int32_t addr;
405		i = parse_dotted_ip(str, &addr);
406		if (i == 0 || str[i] != 0)
407			return 0;
408		set_ip_epdisc(ep, addr);
409		return 1;
410	}
411	if (i == EPD_MAC && get_if_hwaddr(ep->value, str) >= 0) {
412		ep->length = 6;
413		return 1;
414	}
415
416	p = str;
417	for (l = 0; l < MAX_ENDP_LEN; ++l) {
418		if (*str == 0)
419			break;
420		if (p <= str)
421			for (p = str; isxdigit(*p); ++p)
422				;
423		i = p - str;
424		if (i == 0)
425			return 0;
426		ep->value[l] = hexc_val(*str++);
427		if ((i & 1) == 0)
428			ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
429		if (*str == ':' || *str == '.')
430			++str;
431	}
432	if (*str != 0 || (ep->class == EPD_MAC && l != 6))
433		return 0;
434	ep->length = l;
435	return 1;
436}
437
438