1 /*
2 * multilink.c - support routines for multilink.
3 *
4 * Copyright (c) 2000-2001 by Sun Microsystems, Inc.
5 * All rights reserved.
6 *
7 * Copyright (c) 2000 Paul Mackerras.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms are permitted
11 * provided that the above copyright notice and this paragraph are
12 * duplicated in all such forms. The name of the author may not be
13 * used to endorse or promote products derived from this software
14 * without specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
17 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 */
19
20 #include <string.h>
21 #include <ctype.h>
22 #include <stdlib.h>
23 #include <netdb.h>
24 #include <errno.h>
25 #include <signal.h>
26 #include <netinet/in.h>
27
28 #include "pppd.h"
29 #include "fsm.h"
30 #include "lcp.h"
31
32 #ifdef HAVE_MULTILINK
33 #include "tdb.h"
34 #endif
35
36 #define set_ip_epdisc(ep, addr) ( \
37 ep->length = 4, \
38 ep->value[0] = addr >> 24, \
39 ep->value[1] = addr >> 16, \
40 ep->value[2] = addr >> 8, \
41 ep->value[3] = addr \
42 )
43
44 #ifdef HAVE_MULTILINK
45 bool endpoint_specified; /* user gave explicit endpoint discriminator */
46 char *bundle_id; /* identifier for our bundle */
47
48 static int get_default_epdisc __P((struct epdisc *));
49 static int parse_num __P((char *str, const char *key, int *valp));
50 static int owns_unit __P((TDB_DATA pid, int unit));
51
52 #define process_exists(n) (kill(0, (n)) == 0 || errno != ESRCH)
53
54 void
mp_check_options()55 mp_check_options()
56 {
57 lcp_options *wo = &lcp_wantoptions[0];
58 lcp_options *ao = &lcp_allowoptions[0];
59
60 if (!multilink)
61 return;
62 /* if we're doing multilink, we have to negotiate MRRU */
63 if (!wo->neg_mrru) {
64 /* mrru not specified, default to mru */
65 wo->mrru = wo->mru;
66 wo->neg_mrru = 1;
67 }
68 ao->mrru = ao->mru;
69 ao->neg_mrru = 1;
70
71 if (!wo->neg_endpoint && !noendpoint) {
72 /* get a default endpoint value */
73 wo->neg_endpoint = get_default_epdisc(&wo->endpoint);
74 if (wo->neg_endpoint)
75 dbglog("using default endpoint %s",
76 epdisc_to_str(&wo->endpoint));
77 }
78 }
79
80 /*
81 * Make a new bundle or join us to an existing bundle
82 * if we are doing multilink.
83 */
84 int
mp_join_bundle()85 mp_join_bundle()
86 {
87 lcp_options *go = &lcp_gotoptions[0];
88 lcp_options *ho = &lcp_hisoptions[0];
89 int unit, pppd_pid;
90 int l;
91 char *p;
92 TDB_DATA key, pid, rec;
93
94 if (!go->neg_mrru || !ho->neg_mrru) {
95 /* not doing multilink */
96 if (go->neg_mrru)
97 notice("oops, multilink negotiated only for receive");
98 multilink = 0;
99 if (demand) {
100 /* already have a bundle */
101 cfg_bundle(0, 0, 0, 0);
102 return 0;
103 }
104 make_new_bundle(0, 0, 0, 0);
105 set_ifunit(1);
106 return 0;
107 }
108
109 /*
110 * Find the appropriate bundle or join a new one.
111 * First we make up a name for the bundle.
112 * The length estimate is worst-case assuming every
113 * character has to be quoted.
114 *
115 * Note - RFC 1990 requires that an unnegotiated endpoint
116 * discriminator value be equivalent to negotiating with class
117 * zero. Do not test ho->neg_endpoint here.
118 */
119 l = 4 * strlen(peer_authname) + 10;
120 l += 3 * ho->endpoint.length + 8;
121 if (bundle_name)
122 l += 3 * strlen(bundle_name) + 2;
123 bundle_id = malloc(l);
124 if (bundle_id == NULL)
125 novm("bundle identifier");
126
127 p = bundle_id;
128 p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
129 *p++ = '/';
130 p += slprintf(p, bundle_id+l-p, "%s", epdisc_to_str(&ho->endpoint));
131 if (bundle_name)
132 p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
133 dbglog("bundle_id = %s", bundle_id+7);
134
135 /*
136 * For demand mode, we only need to configure the bundle
137 * and attach the link.
138 */
139 if (demand) {
140 cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
141 script_setenv("BUNDLE", bundle_id + 7, 1);
142 return 0;
143 }
144
145 /*
146 * Check if the bundle ID is already in the database.
147 */
148 unit = -1;
149 tdb_writelock(pppdb);
150 key.dptr = bundle_id;
151 key.dsize = p - bundle_id;
152 pid = tdb_fetch(pppdb, key);
153 if (pid.dptr != NULL) {
154 /* bundle ID exists, see if the pppd record exists */
155 rec = tdb_fetch(pppdb, pid);
156 if (rec.dptr != NULL) {
157 /* it does, parse the interface number */
158 parse_num(rec.dptr, "IFNAME=ppp", &unit);
159 /* check the pid value */
160 if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
161 || !process_exists(pppd_pid)
162 || !owns_unit(pid, unit))
163 unit = -1;
164 free(rec.dptr);
165 }
166 free(pid.dptr);
167 }
168
169 if (unit >= 0) {
170 /* attach to existing unit */
171 if (bundle_attach(unit)) {
172 set_ifunit(0);
173 script_setenv("BUNDLE", bundle_id + 7, 0);
174 tdb_writeunlock(pppdb);
175 info("Link attached to %s", ifname);
176 return 1;
177 }
178 /* attach failed because bundle doesn't exist */
179 }
180
181 /* we have to make a new bundle */
182 make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
183 set_ifunit(1);
184 script_setenv("BUNDLE", bundle_id + 7, 1);
185 tdb_writeunlock(pppdb);
186 info("New bundle %s created", ifname);
187 return 0;
188 }
189
190 static int
parse_num(str,key,valp)191 parse_num(str, key, valp)
192 char *str;
193 const char *key;
194 int *valp;
195 {
196 char *p, *endp;
197 int i;
198
199 p = strstr(str, key);
200 if (p != 0) {
201 p += strlen(key);
202 i = strtol(p, &endp, 10);
203 if (endp != p && (*endp == 0 || *endp == ';')) {
204 *valp = i;
205 return 1;
206 }
207 }
208 return 0;
209 }
210
211 /*
212 * Check whether the pppd identified by `key' still owns ppp unit `unit'.
213 */
214 static int
owns_unit(key,unit)215 owns_unit(key, unit)
216 TDB_DATA key;
217 int unit;
218 {
219 char ifkey[32];
220 TDB_DATA kd, vd;
221 int ret = 0;
222
223 (void) slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
224 kd.dptr = ifkey;
225 kd.dsize = strlen(ifkey);
226 vd = tdb_fetch(pppdb, kd);
227 if (vd.dptr != NULL) {
228 ret = vd.dsize == key.dsize
229 && memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
230 free(vd.dptr);
231 }
232 return ret;
233 }
234
235 static int
get_default_epdisc(ep)236 get_default_epdisc(ep)
237 struct epdisc *ep;
238 {
239 struct hostent *hp;
240 u_int32_t addr;
241
242 if (get_first_hwaddr(ep->value, sizeof(ep->value))) {
243 ep->class = EPD_MAC;
244 ep->length = 6;
245 return 1;
246 }
247
248 /* see if our hostname corresponds to a reasonable IP address */
249 hp = gethostbyname(hostname);
250 if (hp != NULL) {
251 addr = *(u_int32_t *)hp->h_addr;
252 if (!bad_ip_adrs(addr)) {
253 addr = ntohl(addr);
254 if (!LOCAL_IP_ADDR(addr)) {
255 ep->class = EPD_IP;
256 set_ip_epdisc(ep, addr);
257 return 1;
258 }
259 }
260 }
261
262 return 0;
263 }
264 #endif /* HAVE_MULTILINK */
265
266 /*
267 * epdisc_to_str - make a printable string from an endpoint discriminator.
268 */
269
270 static char *endp_class_names[] = {
271 "null", "local", "IP", "MAC", "magic", "phone"
272 };
273
274 char *
epdisc_to_str(ep)275 epdisc_to_str(ep)
276 struct epdisc *ep;
277 {
278 static char str[MAX_ENDP_LEN*3+8];
279 u_char *p = ep->value;
280 int i, mask = 0;
281 char *q, c, c2;
282
283 if (ep->class == EPD_NULL && ep->length == 0)
284 return "null";
285 if (ep->class == EPD_IP && ep->length == 4) {
286 u_int32_t addr;
287
288 GETLONG(addr, p);
289 (void) slprintf(str, sizeof(str), "IP:%I", htonl(addr));
290 return str;
291 }
292
293 c = ':';
294 c2 = '.';
295 if (ep->class == EPD_MAC && ep->length == 6)
296 c2 = ':';
297 else if (ep->class == EPD_MAGIC && (ep->length % 4) == 0)
298 mask = 3;
299 q = str;
300 if (ep->class <= EPD_PHONENUM)
301 q += slprintf(q, sizeof(str)-1, "%s",
302 endp_class_names[ep->class]);
303 else
304 q += slprintf(q, sizeof(str)-1, "%d", ep->class);
305 c = ':';
306 for (i = 0; i < ep->length && i < MAX_ENDP_LEN; ++i) {
307 if ((i & mask) == 0) {
308 *q++ = c;
309 c = c2;
310 }
311 q += slprintf(q, str + sizeof(str) - q, "%.2x", ep->value[i]);
312 }
313 return str;
314 }
315
hexc_val(int c)316 static int hexc_val(int c)
317 {
318 if (c >= 'a')
319 return c - 'a' + 10;
320 if (c >= 'A')
321 return c - 'A' + 10;
322 return c - '0';
323 }
324
325 int
str_to_epdisc(ep,str)326 str_to_epdisc(ep, str)
327 struct epdisc *ep;
328 char *str;
329 {
330 int i, l;
331 char *p, *endp;
332
333 for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
334 int sl = strlen(endp_class_names[i]);
335 if (strncasecmp(str, endp_class_names[i], sl) == 0) {
336 str += sl;
337 break;
338 }
339 }
340 if (i > EPD_PHONENUM) {
341 /* not a class name, try a decimal class number */
342 i = strtol(str, &endp, 10);
343 if (endp == str) {
344 option_error("cannot parse endpoint class in \"%s\"",
345 str);
346 return 0; /* can't parse class number */
347 }
348 str = endp;
349 }
350 ep->class = i;
351 if (*str == 0) {
352 ep->length = 0;
353 return 1;
354 }
355 if (*str != ':' && *str != '.') {
356 option_error("invalid class/value separator '%c'", *str);
357 return 0;
358 }
359 ++str;
360
361 if (i == EPD_IP) {
362 u_int32_t addr;
363 i = parse_dotted_ip(str, &addr);
364 if (i == 0 || str[i] != 0)
365 return 0;
366 set_ip_epdisc(ep, addr);
367 dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
368 return 1;
369 }
370 if (i == EPD_MAC &&
371 get_if_hwaddr(ep->value, sizeof(ep->value), str) >= 0) {
372 ep->length = 6;
373 dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
374 return 1;
375 }
376
377 p = str;
378 for (l = 0; l < MAX_ENDP_LEN; ++l) {
379 if (*str == 0)
380 break;
381 if (p <= str)
382 for (p = str; isxdigit(*p); ++p)
383 ;
384 i = p - str;
385 if (i == 0) {
386 option_error("no valid hex digits in \"%s\"", str);
387 return 0;
388 }
389 ep->value[l] = hexc_val(*str++);
390 if ((i & 1) == 0)
391 ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
392 if (*str == ':' || *str == '.')
393 ++str;
394 }
395 if (*str != 0) {
396 option_error("too many bytes in value; max is %d",
397 MAX_ENDP_LEN);
398 return 0;
399 }
400 if (ep->class == EPD_MAC && l != 6) {
401 option_error("bad endpoint; MAC address must have 6 bytes");
402 return 0;
403 }
404 ep->length = l;
405 dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
406 return 1;
407 }
408