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 #if !defined(lint) && !defined(_lint)
  39 static const char rcsid[] = RCSID;
  40 #endif
  41
  42 #define set_ip_epdisc(ep, addr) (       \
  43         ep->length = 4,                 \
  44         ep->value[0] = addr >> 24,      \
  45         ep->value[1] = addr >> 16,      \
  46         ep->value[2] = addr >> 8,       \
  47         ep->value[3] = addr             \
  48 )
  49
  50 #ifdef HAVE_MULTILINK
  51 bool endpoint_specified;        /* user gave explicit endpoint discriminator */
  52 char *bundle_id;                /* identifier for our bundle */
  53
  54 static int get_default_epdisc __P((struct epdisc *));
  55 static int parse_num __P((char *str, const char *key, int *valp));
  56 static int owns_unit __P((TDB_DATA pid, int unit));
  57
  58 #define process_exists(n)       (kill(0, (n)) == 0 || errno != ESRCH)
  59
  60 void
  61 mp_check_options()
  62 {
  63         lcp_options *wo = &lcp_wantoptions[0];
  64         lcp_options *ao = &lcp_allowoptions[0];
  65
  66         if (!multilink)
  67                 return;
  68         /* if we're doing multilink, we have to negotiate MRRU */
  69         if (!wo->neg_mrru) {
  70                 /* mrru not specified, default to mru */
  71                 wo->mrru = wo->mru;
  72                 wo->neg_mrru = 1;
  73         }
  74         ao->mrru = ao->mru;
  75         ao->neg_mrru = 1;
  76
  77         if (!wo->neg_endpoint && !noendpoint) {
  78                 /* get a default endpoint value */
  79                 wo->neg_endpoint = get_default_epdisc(&wo->endpoint);
  80                 if (wo->neg_endpoint)
  81                         dbglog("using default endpoint %s",
  82                                epdisc_to_str(&wo->endpoint));
  83         }
  84 }
  85
  86 /*
  87  * Make a new bundle or join us to an existing bundle
  88  * if we are doing multilink.
  89  */
  90 int
  91 mp_join_bundle()
  92 {
  93         lcp_options *go = &lcp_gotoptions[0];
  94         lcp_options *ho = &lcp_hisoptions[0];
  95         int unit, pppd_pid;
  96         int l;
  97         char *p;
  98         TDB_DATA key, pid, rec;
  99
 100         if (!go->neg_mrru || !ho->neg_mrru) {
 101                 /* not doing multilink */
 102                 if (go->neg_mrru)
 103                         notice("oops, multilink negotiated only for receive");
 104                 multilink = 0;
 105                 if (demand) {
 106                         /* already have a bundle */
 107                         cfg_bundle(0, 0, 0, 0);
 108                         return 0;
 109                 }
 110                 make_new_bundle(0, 0, 0, 0);
 111                 set_ifunit(1);
 112                 return 0;
 113         }
 114
 115         /*
 116          * Find the appropriate bundle or join a new one.
 117          * First we make up a name for the bundle.
 118          * The length estimate is worst-case assuming every
 119          * character has to be quoted.
 120          *
 121          * Note - RFC 1990 requires that an unnegotiated endpoint
 122          * discriminator value be equivalent to negotiating with class
 123          * zero.  Do not test ho->neg_endpoint here.
 124          */
 125         l = 4 * strlen(peer_authname) + 10;
 126         l += 3 * ho->endpoint.length + 8;
 127         if (bundle_name)
 128                 l += 3 * strlen(bundle_name) + 2;
 129         bundle_id = malloc(l);
 130         if (bundle_id == NULL)
 131                 novm("bundle identifier");
 132
 133         p = bundle_id;
 134         p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
 135         *p++ = '/';
 136         p += slprintf(p, bundle_id+l-p, "%s", epdisc_to_str(&ho->endpoint));
 137         if (bundle_name)
 138                 p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
 139         dbglog("bundle_id = %s", bundle_id+7);
 140
 141         /*
 142          * For demand mode, we only need to configure the bundle
 143          * and attach the link.
 144          */
 145         if (demand) {
 146                 cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
 147                 script_setenv("BUNDLE", bundle_id + 7, 1);
 148                 return 0;
 149         }
 150
 151         /*
 152          * Check if the bundle ID is already in the database.
 153          */
 154         unit = -1;
 155         tdb_writelock(pppdb);
 156         key.dptr = bundle_id;
 157         key.dsize = p - bundle_id;
 158         pid = tdb_fetch(pppdb, key);
 159         if (pid.dptr != NULL) {
 160                 /* bundle ID exists, see if the pppd record exists */
 161                 rec = tdb_fetch(pppdb, pid);
 162                 if (rec.dptr != NULL) {
 163                         /* it does, parse the interface number */
 164                         parse_num(rec.dptr, "IFNAME=ppp", &unit);
 165                         /* check the pid value */
 166                         if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
 167                             || !process_exists(pppd_pid)
 168                             || !owns_unit(pid, unit))
 169                                 unit = -1;
 170                         free(rec.dptr);
 171                 }
 172                 free(pid.dptr);
 173         }
 174
 175         if (unit >= 0) {
 176                 /* attach to existing unit */
 177                 if (bundle_attach(unit)) {
 178                         set_ifunit(0);
 179                         script_setenv("BUNDLE", bundle_id + 7, 0);
 180                         tdb_writeunlock(pppdb);
 181                         info("Link attached to %s", ifname);
 182                         return 1;
 183                 }
 184                 /* attach failed because bundle doesn't exist */
 185         }
 186
 187         /* we have to make a new bundle */
 188         make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
 189         set_ifunit(1);
 190         script_setenv("BUNDLE", bundle_id + 7, 1);
 191         tdb_writeunlock(pppdb);
 192         info("New bundle %s created", ifname);
 193         return 0;
 194 }
 195
 196 static int
 197 parse_num(str, key, valp)
 198      char *str;
 199      const char *key;
 200      int *valp;
 201 {
 202         char *p, *endp;
 203         int i;
 204
 205         p = strstr(str, key);
 206         if (p != 0) {
 207                 p += strlen(key);
 208                 i = strtol(p, &endp, 10);
 209                 if (endp != p && (*endp == 0 || *endp == ';')) {
 210                         *valp = i;
 211                         return 1;
 212                 }
 213         }
 214         return 0;
 215 }
 216
 217 /*
 218  * Check whether the pppd identified by `key' still owns ppp unit `unit'.
 219  */
 220 static int
 221 owns_unit(key, unit)
 222      TDB_DATA key;
 223      int unit;
 224 {
 225         char ifkey[32];
 226         TDB_DATA kd, vd;
 227         int ret = 0;
 228
 229         (void) slprintf(ifkey, sizeof(ifkey), "IFNAME=ppp%d", unit);
 230         kd.dptr = ifkey;
 231         kd.dsize = strlen(ifkey);
 232         vd = tdb_fetch(pppdb, kd);
 233         if (vd.dptr != NULL) {
 234                 ret = vd.dsize == key.dsize
 235                         && memcmp(vd.dptr, key.dptr, vd.dsize) == 0;
 236                 free(vd.dptr);
 237         }
 238         return ret;
 239 }
 240
 241 static int
 242 get_default_epdisc(ep)
 243      struct epdisc *ep;
 244 {
 245         struct hostent *hp;
 246         u_int32_t addr;
 247
 248         if (get_first_hwaddr(ep->value, sizeof(ep->value))) {
 249                 ep->class = EPD_MAC;
 250                 ep->length = 6;
 251                 return 1;
 252         }
 253
 254         /* see if our hostname corresponds to a reasonable IP address */
 255         hp = gethostbyname(hostname);
 256         if (hp != NULL) {
 257                 addr = *(u_int32_t *)hp->h_addr;
 258                 if (!bad_ip_adrs(addr)) {
 259                         addr = ntohl(addr);
 260                         if (!LOCAL_IP_ADDR(addr)) {
 261                                 ep->class = EPD_IP;
 262                                 set_ip_epdisc(ep, addr);
 263                                 return 1;
 264                         }
 265                 }
 266         }
 267
 268         return 0;
 269 }
 270 #endif /* HAVE_MULTILINK */
 271
 272 /*
 273  * epdisc_to_str - make a printable string from an endpoint discriminator.
 274  */
 275
 276 static char *endp_class_names[] = {
 277     "null", "local", "IP", "MAC", "magic", "phone"
 278 };
 279
 280 char *
 281 epdisc_to_str(ep)
 282      struct epdisc *ep;
 283 {
 284         static char str[MAX_ENDP_LEN*3+8];
 285         u_char *p = ep->value;
 286         int i, mask = 0;
 287         char *q, c, c2;
 288
 289         if (ep->class == EPD_NULL && ep->length == 0)
 290                 return "null";
 291         if (ep->class == EPD_IP && ep->length == 4) {
 292                 u_int32_t addr;
 293
 294                 GETLONG(addr, p);
 295                 (void) slprintf(str, sizeof(str), "IP:%I", htonl(addr));
 296                 return str;
 297         }
 298
 299         c = ':';
 300         c2 = '.';
 301         if (ep->class == EPD_MAC && ep->length == 6)
 302                 c2 = ':';
 303         else if (ep->class == EPD_MAGIC && (ep->length % 4) == 0)
 304                 mask = 3;
 305         q = str;
 306         if (ep->class <= EPD_PHONENUM)
 307                 q += slprintf(q, sizeof(str)-1, "%s",
 308                               endp_class_names[ep->class]);
 309         else
 310                 q += slprintf(q, sizeof(str)-1, "%d", ep->class);
 311         c = ':';
 312         for (i = 0; i < ep->length && i < MAX_ENDP_LEN; ++i) {
 313                 if ((i & mask) == 0) {
 314                         *q++ = c;
 315                         c = c2;
 316                 }
 317                 q += slprintf(q, str + sizeof(str) - q, "%.2x", ep->value[i]);
 318         }
 319         return str;
 320 }
 321
 322 static int hexc_val(int c)
 323 {
 324         if (c >= 'a')
 325                 return c - 'a' + 10;
 326         if (c >= 'A')
 327                 return c - 'A' + 10;
 328         return c - '0';
 329 }
 330
 331 int
 332 str_to_epdisc(ep, str)
 333      struct epdisc *ep;
 334      char *str;
 335 {
 336         int i, l;
 337         char *p, *endp;
 338
 339         for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
 340                 int sl = strlen(endp_class_names[i]);
 341                 if (strncasecmp(str, endp_class_names[i], sl) == 0) {
 342                         str += sl;
 343                         break;
 344                 }
 345         }
 346         if (i > EPD_PHONENUM) {
 347                 /* not a class name, try a decimal class number */
 348                 i = strtol(str, &endp, 10);
 349                 if (endp == str) {
 350                         option_error("cannot parse endpoint class in \"%s\"",
 351                             str);
 352                         return 0;       /* can't parse class number */
 353                 }
 354                 str = endp;
 355         }
 356         ep->class = i;
 357         if (*str == 0) {
 358                 ep->length = 0;
 359                 return 1;
 360         }
 361         if (*str != ':' && *str != '.') {
 362                 option_error("invalid class/value separator '%c'", *str);
 363                 return 0;
 364         }
 365         ++str;
 366
 367         if (i == EPD_IP) {
 368                 u_int32_t addr;
 369                 i = parse_dotted_ip(str, &addr);
 370                 if (i == 0 || str[i] != 0)
 371                         return 0;
 372                 set_ip_epdisc(ep, addr);
 373                 dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 374                 return 1;
 375         }
 376         if (i == EPD_MAC &&
 377             get_if_hwaddr(ep->value, sizeof(ep->value), str) >= 0) {
 378                 ep->length = 6;
 379                 dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 380                 return 1;
 381         }
 382
 383         p = str;
 384         for (l = 0; l < MAX_ENDP_LEN; ++l) {
 385                 if (*str == 0)
 386                         break;
 387                 if (p <= str)
 388                         for (p = str; isxdigit(*p); ++p)
 389                                 ;
 390                 i = p - str;
 391                 if (i == 0) {
 392                         option_error("no valid hex digits in \"%s\"", str);
 393                         return 0;
 394                 }
 395                 ep->value[l] = hexc_val(*str++);
 396                 if ((i & 1) == 0)
 397                         ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
 398                 if (*str == ':' || *str == '.')
 399                         ++str;
 400         }
 401         if (*str != 0) {
 402                 option_error("too many bytes in value; max is %d",
 403                     MAX_ENDP_LEN);
 404                 return 0;
 405         }
 406         if (ep->class == EPD_MAC && l != 6) {
 407                 option_error("bad endpoint; MAC address must have 6 bytes");
 408                 return 0;
 409         }
 410         ep->length = l;
 411         dbglog("str_to_epdisc -> %s", epdisc_to_str(ep));
 412         return 1;
 413 }