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 #pragma ident   "%Z%%M% %I%     %E% SMI"
  21 #define RCSID   "$Id: $"
  22
  23 #include <string.h>
  24 #include <ctype.h>
  25 #include <stdlib.h>
  26 #include <netdb.h>
  27 #include <errno.h>
  28 #include <signal.h>
  29 #include <netinet/in.h>
  30
  31 #include "pppd.h"
  32 #include "fsm.h"
  33 #include "lcp.h"
  34
  35 #ifdef HAVE_MULTILINK
  36 #include "tdb.h"
  37 #endif
  38 static const char rcsid[] = RCSID;
  39
  40 #define set_ip_epdisc(ep, addr) (       \
  41         ep->length = 4,                 \
  42         ep->value[0] = addr >> 24,      \
  43         ep->value[1] = addr >> 16,      \
  44         ep->value[2] = addr >> 8,       \
  45         ep->value[3] = addr             \
  46 )
  47
  48 #ifdef HAVE_MULTILINK
  49 bool endpoint_specified;        /* user gave explicit endpoint discriminator */
  50 char *bundle_id;                /* identifier for our bundle */
  51
  52 static int get_default_epdisc __P((struct epdisc *));
  53 static int parse_num __P((char *str, const char *key, int *valp));
  54 static int owns_unit __P((TDB_DATA pid, int unit));
  55
  56 #define process_exists(n)       (kill(0, (n)) == 0 || errno != ESRCH)
  57
  58 void
  59 mp_check_options()
  60 {
  61         lcp_options *wo = &lcp_wantoptions[0];
  62         lcp_options *ao = &lcp_allowoptions[0];
  63
  64         if (!multilink)
  65                 return;
  66         /* if we're doing multilink, we have to negotiate MRRU */
  67         if (!wo->neg_mrru) {
  68                 /* mrru not specified, default to mru */
  69                 wo->mrru = wo->mru;
  70                 wo->neg_mrru = 1;
  71         }
  72         ao->mrru = ao->mru;
  73         ao->neg_mrru = 1;
  74
  75         if (!wo->neg_endpoint && !noendpoint) {
  76                 /* get a default endpoint value */
  77                 wo->neg_endpoint = get_default_epdisc(&wo->endpoint);
  78                 if (wo->neg_endpoint)
  79                         dbglog("using default endpoint %s",
  80                                epdisc_to_str(&wo->endpoint));
  81         }
  82 }
  83
  84 /*
  85  * Make a new bundle or join us to an existing bundle
  86  * if we are doing multilink.
  87  */
  88 int
  89 mp_join_bundle()
  90 {
  91         lcp_options *go = &lcp_gotoptions[0];
  92         lcp_options *ho = &lcp_hisoptions[0];
  93         int unit, pppd_pid;
  94         int l;
  95         char *p;
  96         TDB_DATA key, pid, rec;
  97
  98         if (!go->neg_mrru || !ho->neg_mrru) {
  99                 /* not doing multilink */
 100                 if (go->neg_mrru)
 101                         notice("oops, multilink negotiated only for receive");
 102                 multilink = 0;
 103                 if (demand) {
 104                         /* already have a bundle */
 105                         cfg_bundle(0, 0, 0, 0);
 106                         return 0;
 107                 }
 108                 make_new_bundle(0, 0, 0, 0);
 109                 set_ifunit(1);
 110                 return 0;
 111         }
 112
 113         /*
 114          * Find the appropriate bundle or join a new one.
 115          * First we make up a name for the bundle.
 116          * The length estimate is worst-case assuming every
 117          * character has to be quoted.
 118          *
 119          * Note - RFC 1990 requires that an unnegotiated endpoint
 120          * discriminator value be equivalent to negotiating with class
 121          * zero.  Do not test ho->neg_endpoint here.
 122          */
 123         l = 4 * strlen(peer_authname) + 10;
 124         l += 3 * ho->endpoint.length + 8;
 125         if (bundle_name)
 126                 l += 3 * strlen(bundle_name) + 2;
 127         bundle_id = malloc(l);
 128         if (bundle_id == NULL)
 129                 novm("bundle identifier");
 130
 131         p = bundle_id;
 132         p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
 133         *p++ = '/';
 134         p += slprintf(p, bundle_id+l-p, "%s", epdisc_to_str(&ho->endpoint));
 135         if (bundle_name)
 136                 p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
 137         dbglog("bundle_id = %s", bundle_id+7);
 138
 139         /*
 140          * For demand mode, we only need to configure the bundle
 141          * and attach the link.
 142          */
 143         if (demand) {
 144                 cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
 145                 script_setenv("BUNDLE", bundle_id + 7, 1);
 146                 return 0;
 147         }
 148
 149         /*
 150          * Check if the bundle ID is already in the database.
 151          */
 152         unit = -1;
 153         tdb_writelock(pppdb);
 154         key.dptr = bundle_id;
 155         key.dsize = p - bundle_id;
 156         pid = tdb_fetch(pppdb, key);
 157         if (pid.dptr != NULL) {
 158                 /* bundle ID exists, see if the pppd record exists */
 159                 rec = tdb_fetch(pppdb, pid);
 160                 if (rec.dptr != NULL) {
 161                         /* it does, parse the interface number */
 162                         parse_num(rec.dptr, "IFNAME=ppp", &unit);
 163                         /* check the pid value */
 164                         if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
 165                             || !process_exists(pppd_pid)
 166                             || !owns_unit(pid, unit))
 167                                 unit = -1;
 168                         free(rec.dptr);
 169                 }
 170                 free(pid.dptr);
 171         }
 172
 173         if (unit >= 0) {
 174                 /* attach to existing unit */
 175                 if (bundle_attach(unit)) {
 176                         set_ifunit(0);
 177                         script_setenv("BUNDLE", bundle_id + 7, 0);
 178                         tdb_writeunlock(pppdb);
 179                         info("Link attached to %s", ifname);
 180                         return 1;
 181                 }
 182                 /* attach failed because bundle doesn't exist */
 183         }
 184
 185         /* we have to make a new bundle */
 186         make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
 187         set_ifunit(1);
 188         script_setenv("BUNDLE", bundle_id + 7, 1);
 189         tdb_writeunlock(pppdb);
 190         info("New bundle %s created", ifname);
 191         return 0;
 192 }
 193
 194 static int
 195 parse_num(str, key, valp)
 196      char *str;
 197      const char *key;
 198      int *valp;
 199 {
 200         char *p, *endp;
 201         int i;
 202
 203         p = strstr(str, key);
 204         if (p != 0) {
 205                 p += strlen(key);
 206                 i = strtol(p, &endp, 10);
 207                 if (endp != p && (*endp == 0 || *endp == ';')) {
 208                         *valp = i;
 209                         return 1;
 210                 }
 211         }
 212         return 0;
 213 }
 214
 215 /*
 216  * Check whether the pppd identified by `key' still owns ppp unit `unit'.
 217  */
 218 static int
 219 owns_unit(key, unit)
 220      TDB_DATA key;
 221      int unit;
 222 {
 223         char ifkey[32];
 224         TDB_DATA kd, vd;
 225         int ret = 0;
 226
 227         (void) slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
 228         kd.dptr = ifkey;
 229         kd.dsize = strlen(ifkey);
 230         vd = tdb_fetch(pppdb, kd);
 231         if (vd.dptr != NULL) {
 232                 ret = vd.dsize == key.dsize
 233                         && memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
 234                 free(vd.dptr);
 235         }
 236         return ret;
 237 }
 238
 239 static int
 240 get_default_epdisc(ep)
 241      struct epdisc *ep;
 242 {
 243         struct hostent *hp;
 244         u_int32_t addr;
 245
 246         if (get_first_hwaddr(ep->value, sizeof(ep->value))) {
 247                 ep->class = EPD_MAC;
 248                 ep->length = 6;
 249                 return 1;
 250         }
 251
 252         /* see if our hostname corresponds to a reasonable IP address */
 253         hp = gethostbyname(hostname);
 254         if (hp != NULL) {
 255                 addr = *(u_int32_t *)hp->h_addr;
 256                 if (!bad_ip_adrs(addr)) {
 257                         addr = ntohl(addr);
 258                         if (!LOCAL_IP_ADDR(addr)) {
 259                                 ep->class = EPD_IP;
 260                                 set_ip_epdisc(ep, addr);
 261                                 return 1;
 262                         }
 263                 }
 264         }
 265
 266         return 0;
 267 }
 268 #endif /* HAVE_MULTILINK */
 269
 270 /*
 271  * epdisc_to_str - make a printable string from an endpoint discriminator.
 272  */
 273
 274 static char *endp_class_names[] = {
 275     "null", "local", "IP", "MAC", "magic", "phone"
 276 };
 277
 278 char *
 279 epdisc_to_str(ep)
 280      struct epdisc *ep;
 281 {
 282         static char str[MAX_ENDP_LEN*3+8];
 283         u_char *p = ep->value;
 284         int i, mask = 0;
 285         char *q, c, c2;
 286
 287         if (ep->class == EPD_NULL && ep->length == 0)
 288                 return "null";
 289         if (ep->class == EPD_IP && ep->length == 4) {
 290                 u_int32_t addr;
 291
 292                 GETLONG(addr, p);
 293                 (void) slprintf(str, sizeof(str), "IP:%I", htonl(addr));
 294                 return str;
 295         }
 296
 297         c = ':';
 298         c2 = '.';
 299         if (ep->class == EPD_MAC && ep->length == 6)
 300                 c2 = ':';
 301         else if (ep->class == EPD_MAGIC && (ep->length % 4) == 0)
 302                 mask = 3;
 303         q = str;
 304         if (ep->class <= EPD_PHONENUM)
 305                 q += slprintf(q, sizeof(str)-1, "%s",
 306                               endp_class_names[ep->class]);
 307         else
 308                 q += slprintf(q, sizeof(str)-1, "%d", ep->class);
 309         c = ':';
 310         for (i = 0; i < ep->length && i < MAX_ENDP_LEN; ++i) {
 311                 if ((i & mask) == 0) {
 312                         *q++ = c;
 313                         c = c2;
 314                 }
 315                 q += slprintf(q, str + sizeof(str) - q, "%.2x", ep->value[i]);
 316         }
 317         return str;
 318 }
 319
 320 static int hexc_val(int c)
 321 {
 322         if (c >= 'a')
 323                 return c - 'a' + 10;
 324         if (c >= 'A')
 325                 return c - 'A' + 10;
 326         return c - '0';
 327 }
 328
 329 int
 330 str_to_epdisc(ep, str)
 331      struct epdisc *ep;
 332      char *str;
 333 {
 334         int i, l;
 335         char *p, *endp;
 336
 337         for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
 338                 int sl = strlen(endp_class_names[i]);
 339                 if (strncasecmp(str, endp_class_names[i], sl) == 0) {
 340                         str += sl;
 341                         break;
 342                 }
 343         }
 344         if (i > EPD_PHONENUM) {
 345                 /* not a class name, try a decimal class number */
 346                 i = strtol(str, &endp, 10);
 347                 if (endp == str) {
 348                         option_error("cannot parse endpoint class in \"%s\"",
 349                             str);
 350                         return 0;       /* can't parse class number */
 351                 }
 352                 str = endp;
 353         }
 354         ep->class = i;
 355         if (*str == 0) {
 356                 ep->length = 0;
 357                 return 1;
 358         }
 359         if (*str != ':' && *str != '.') {
 360                 option_error("invalid class/value separator '%c'", *str);
 361                 return 0;
 362         }
 363         ++str;
 364
 365         if (i == EPD_IP) {
 366                 u_int32_t addr;
 367                 i = parse_dotted_ip(str, &addr);
 368                 if (i == 0 || str[i] != 0)
 369                         return 0;
 370                 set_ip_epdisc(ep, addr);
 371                 dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 372                 return 1;
 373         }
 374         if (i == EPD_MAC &&
 375             get_if_hwaddr(ep->value, sizeof(ep->value), str) >= 0) {
 376                 ep->length = 6;
 377                 dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 378                 return 1;
 379         }
 380
 381         p = str;
 382         for (l = 0; l < MAX_ENDP_LEN; ++l) {
 383                 if (*str == 0)
 384                         break;
 385                 if (p <= str)
 386                         for (p = str; isxdigit(*p); ++p)
 387                                 ;
 388                 i = p - str;
 389                 if (i == 0) {
 390                         option_error("no valid hex digits in \"%s\"", str);
 391                         return 0;
 392                 }
 393                 ep->value[l] = hexc_val(*str++);
 394                 if ((i & 1) == 0)
 395                         ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
 396                 if (*str == ':' || *str == '.')
 397                         ++str;
 398         }
 399         if (*str != 0) {
 400                 option_error("too many bytes in value; max is %d",
 401                     MAX_ENDP_LEN);
 402                 return 0;
 403         }
 404         if (ep->class == EPD_MAC && l != 6) {
 405                 option_error("bad endpoint; MAC address must have 6 bytes");
 406                 return 0;
 407         }
 408         ep->length = l;
 409         dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 410         return 1;
 411 }