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