usr/src/cmd/cmd-inet/usr.bin/pppd/multilink.c

   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
  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
  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
 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
 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
 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 *
 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
 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
 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 }