release/src/router/ppp/pppd/multilink.c

   1 /*
   2  * multilink.c - support routines for multilink.
   3  *
   4  * Copyright (c) 2000 Paul Mackerras.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms are permitted
   8  * provided that the above copyright notice and this paragraph are
   9  * duplicated in all such forms.  The name of the author may not be
  10  * used to endorse or promote products derived from this software
  11  * without specific prior written permission.
  12  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  13  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  14  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  15  */
  16 #include <string.h>
  17 #include <ctype.h>
  18 #include <stdlib.h>
  19 #include <netdb.h>
  20 #include <errno.h>
  21 #include <signal.h>
  22 #include <netinet/in.h>
  23
  24 #include "pppd.h"
  25 #include "fsm.h"
  26 #include "lcp.h"
  27 #include "tdb.h"
  28
  29 bool endpoint_specified;        /* user gave explicit endpoint discriminator */
  30 char *bundle_id;                /* identifier for our bundle */
  31
  32 extern TDB_CONTEXT *pppdb;
  33 extern char db_key[];
  34
  35 static int get_default_epdisc __P((struct epdisc *));
  36 static int parse_num __P((char *str, const char *key, int *valp));
  37 static int owns_unit __P((TDB_DATA pid, int unit));
  38
  39 #define set_ip_epdisc(ep, addr) do {    \
  40         ep->length = 4;                 \
  41         ep->value[0] = addr >> 24;      \
  42         ep->value[1] = addr >> 16;      \
  43         ep->value[2] = addr >> 8;       \
  44         ep->value[3] = addr;            \
  45 } while (0)
  46
  47 #define LOCAL_IP_ADDR(addr)                                               \
  48         (((addr) & 0xff000000) == 0x0a000000            /* 10.x.x.x */    \
  49          || ((addr) & 0xfff00000) == 0xac100000         /* 172.16.x.x */  \
  50          || ((addr) & 0xffff0000) == 0xc0a80000)        /* 192.168.x.x */
  51
  52 #define process_exists(n)       (kill((n), 0) == 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         }
  75 }
  76
  77 /*
  78  * Make a new bundle or join us to an existing bundle
  79  * if we are doing multilink.
  80  */
  81 int
  82 mp_join_bundle()
  83 {
  84         lcp_options *go = &lcp_gotoptions[0];
  85         lcp_options *ho = &lcp_hisoptions[0];
  86         lcp_options *ao = &lcp_allowoptions[0];
  87         int unit, pppd_pid;
  88         int l, mtu;
  89         char *p;
  90         TDB_DATA key, pid, rec;
  91
  92         if (!go->neg_mrru || !ho->neg_mrru) {
  93                 /* not doing multilink */
  94                 if (go->neg_mrru)
  95                         notice("oops, multilink negotiated only for receive");
  96                 mtu = ho->neg_mru? ho->mru: PPP_MRU;
  97                 if (mtu > ao->mru)
  98                         mtu = ao->mru;
  99                 if (demand) {
 100                         /* already have a bundle */
 101                         cfg_bundle(0, 0, 0, 0);
 102                         netif_set_mtu(0, mtu);
 103                         return 0;
 104                 }
 105                 make_new_bundle(0, 0, 0, 0);
 106                 set_ifunit(1);
 107                 netif_set_mtu(0, mtu);
 108                 return 0;
 109         }
 110
 111         /*
 112          * Find the appropriate bundle or join a new one.
 113          * First we make up a name for the bundle.
 114          * The length estimate is worst-case assuming every
 115          * character has to be quoted.
 116          */
 117         l = 4 * strlen(peer_authname) + 10;
 118         if (ho->neg_endpoint)
 119                 l += 3 * ho->endpoint.length + 8;
 120         if (bundle_name)
 121                 l += 3 * strlen(bundle_name) + 2;
 122         bundle_id = malloc(l);
 123         if (bundle_id == 0)
 124                 novm("bundle identifier");
 125
 126         p = bundle_id;
 127         p += slprintf(p, l-1, "BUNDLE=\"%q\"", peer_authname);
 128         if (ho->neg_endpoint || bundle_name)
 129                 *p++ = '/';
 130         if (ho->neg_endpoint)
 131                 p += slprintf(p, bundle_id+l-p, "%s",
 132                               epdisc_to_str(&ho->endpoint));
 133         if (bundle_name)
 134                 p += slprintf(p, bundle_id+l-p, "/%v", bundle_name);
 135
 136         /*
 137          * For demand mode, we only need to configure the bundle
 138          * and attach the link.
 139          */
 140         mtu = MIN(ho->mrru, ao->mru);
 141         if (demand) {
 142                 cfg_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
 143                 netif_set_mtu(0, mtu);
 144                 script_setenv("BUNDLE", bundle_id + 7, 1);
 145                 return 0;
 146         }
 147
 148         /*
 149          * Check if the bundle ID is already in the database.
 150          */
 151         unit = -1;
 152         tdb_writelock(pppdb);
 153         key.dptr = bundle_id;
 154         key.dsize = p - bundle_id;
 155         pid = tdb_fetch(pppdb, key);
 156         if (pid.dptr != NULL) {
 157                 /* bundle ID exists, see if the pppd record exists */
 158                 rec = tdb_fetch(pppdb, pid);
 159                 if (rec.dptr != NULL) {
 160                         /* it is, parse the interface number */
 161                         parse_num(rec.dptr, "IFNAME=ppp", &unit);
 162                         /* check the pid value */
 163                         if (!parse_num(rec.dptr, "PPPD_PID=", &pppd_pid)
 164                             || !process_exists(pppd_pid)
 165                             || !owns_unit(pid, unit))
 166                                 unit = -1;
 167                         free(rec.dptr);
 168                 }
 169                 free(pid.dptr);
 170         }
 171
 172         if (unit >= 0) {
 173                 /* attach to existing unit */
 174                 if (bundle_attach(unit)) {
 175                         set_ifunit(0);
 176                         script_setenv("BUNDLE", bundle_id + 7, 0);
 177                         tdb_writeunlock(pppdb);
 178                         info("Link attached to %s", ifname);
 179                         return 1;
 180                 }
 181                 /* attach failed because bundle doesn't exist */
 182         }
 183
 184         /* we have to make a new bundle */
 185         make_new_bundle(go->mrru, ho->mrru, go->neg_ssnhf, ho->neg_ssnhf);
 186         set_ifunit(1);
 187         netif_set_mtu(0, mtu);
 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         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         char *p;
 244         struct hostent *hp;
 245         u_int32_t addr;
 246
 247         /* First try for an ethernet MAC address */
 248         p = get_first_ethernet();
 249         if (p != 0 && get_if_hwaddr(ep->value, p) >= 0) {
 250                 ep->class = EPD_MAC;
 251                 ep->length = 6;
 252                 return 1;
 253         }
 254
 255         /* see if our hostname corresponds to a reasonable IP address */
 256         hp = gethostbyname(hostname);
 257         if (hp != NULL) {
 258                 addr = *(u_int32_t *)hp->h_addr;
 259                 if (!bad_ip_adrs(addr)) {
 260                         addr = ntohl(addr);
 261                         if (!LOCAL_IP_ADDR(addr)) {
 262                                 ep->class = EPD_IP;
 263                                 set_ip_epdisc(ep, addr);
 264                                 return 1;
 265                         }
 266                 }
 267         }
 268
 269         return 0;
 270 }
 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                 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                         return 0;       /* can't parse class number */
 351                 str = endp;
 352         }
 353         ep->class = i;
 354         if (*str == 0) {
 355                 ep->length = 0;
 356                 return 1;
 357         }
 358         if (*str != ':' && *str != '.')
 359                 return 0;
 360         ++str;
 361
 362         if (i == EPD_IP) {
 363                 u_int32_t addr;
 364                 i = parse_dotted_ip(str, &addr);
 365                 if (i == 0 || str[i] != 0)
 366                         return 0;
 367                 set_ip_epdisc(ep, addr);
 368                 return 1;
 369         }
 370         if (i == EPD_MAC && get_if_hwaddr(ep->value, str) >= 0) {
 371                 ep->length = 6;
 372                 return 1;
 373         }
 374
 375         p = str;
 376         for (l = 0; l < MAX_ENDP_LEN; ++l) {
 377                 if (*str == 0)
 378                         break;
 379                 if (p <= str)
 380                         for (p = str; isxdigit(*p); ++p)
 381                                 ;
 382                 i = p - str;
 383                 if (i == 0)
 384                         return 0;
 385                 ep->value[l] = hexc_val(*str++);
 386                 if ((i & 1) == 0)
 387                         ep->value[l] = (ep->value[l] << 4) + hexc_val(*str++);
 388                 if (*str == ':' || *str == '.')
 389                         ++str;
 390         }
 391         if (*str != 0 || (ep->class == EPD_MAC && l != 6))
 392                 return 0;
 393         ep->length = l;
 394         return 1;
 395 }
 396