usr.sbin/pppd/cbcp.c

   1 /*
   2  * cbcp - Call Back Configuration Protocol.
   3  *
   4  * Copyright (c) 1995 Pedro Roque Marques
   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 and that any documentation,
  10  * advertising materials, and other materials related to such
  11  * distribution and use acknowledge that the software was developed
  12  * by Pedro Roque Marques.  The name of the author may not be used to
  13  * endorse or promote products derived from this software without
  14  * specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  18  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  19  */
  20
  21 #ifndef lint
  22 static char rcsid[] = "$FreeBSD$";
  23 #endif
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <sys/types.h>
  28 #include <sys/time.h>
  29 #include <syslog.h>
  30
  31 #include "pppd.h"
  32 #include "cbcp.h"
  33 #include "fsm.h"
  34 #include "lcp.h"
  35 #include "ipcp.h"
  36
  37 /*
  38  * Protocol entry points.
  39  */
  40 static void cbcp_init(int unit);
  41 static void cbcp_open(int unit);
  42 static void cbcp_lowerup(int unit);
  43 static void cbcp_input(int unit, u_char *pkt, int len);
  44 static void cbcp_protrej(int unit);
  45 static int  cbcp_printpkt(u_char *pkt, int len,
  46                                 void (*printer)(void *, char *, ...),
  47                                 void *arg);
  48
  49 struct protent cbcp_protent = {
  50     PPP_CBCP,
  51     cbcp_init,
  52     cbcp_input,
  53     cbcp_protrej,
  54     cbcp_lowerup,
  55     NULL,
  56     cbcp_open,
  57     NULL,
  58     cbcp_printpkt,
  59     NULL,
  60     0,
  61     "CBCP",
  62     NULL,
  63     NULL,
  64     NULL
  65 };
  66
  67 cbcp_state cbcp[NUM_PPP];
  68
  69 /* internal prototypes */
  70
  71 static void cbcp_recvreq(cbcp_state *us, char *pckt, int len);
  72 static void cbcp_resp(cbcp_state *us);
  73 static void cbcp_up(cbcp_state *us);
  74 static void cbcp_recvack(cbcp_state *us, char *pckt, int len);
  75 static void cbcp_send(cbcp_state *us, u_char code, u_char *buf, int len);
  76
  77 /* init state */
  78 static void
  79 cbcp_init(iface)
  80     int iface;
  81 {
  82     cbcp_state *us;
  83
  84     us = &cbcp[iface];
  85     memset(us, 0, sizeof(cbcp_state));
  86     us->us_unit = iface;
  87     us->us_type |= (1 << CB_CONF_NO);
  88 }
  89
  90 /* lower layer is up */
  91 static void
  92 cbcp_lowerup(iface)
  93     int iface;
  94 {
  95     cbcp_state *us = &cbcp[iface];
  96
  97     syslog(LOG_DEBUG, "cbcp_lowerup");
  98     syslog(LOG_DEBUG, "want: %d", us->us_type);
  99
 100     if (us->us_type == CB_CONF_USER)
 101         syslog(LOG_DEBUG, "phone no: %s", us->us_number);
 102 }
 103
 104 static void
 105 cbcp_open(unit)
 106     int unit;
 107 {
 108     syslog(LOG_DEBUG, "cbcp_open");
 109 }
 110
 111 /* process an incomming packet */
 112 static void
 113 cbcp_input(unit, inpacket, pktlen)
 114     int unit;
 115     u_char *inpacket;
 116     int pktlen;
 117 {
 118     u_char *inp;
 119     u_char code, id;
 120     u_short len;
 121
 122     cbcp_state *us = &cbcp[unit];
 123
 124     inp = inpacket;
 125
 126     if (pktlen < CBCP_MINLEN) {
 127         syslog(LOG_ERR, "CBCP packet is too small");
 128         return;
 129     }
 130
 131     GETCHAR(code, inp);
 132     GETCHAR(id, inp);
 133     GETSHORT(len, inp);
 134
 135     if (len < CBCP_MINLEN || len > pktlen) {
 136         syslog(LOG_ERR, "CBCP packet: invalid length");
 137         return;
 138     }
 139
 140     len -= CBCP_MINLEN;
 141
 142     switch(code) {
 143     case CBCP_REQ:
 144         us->us_id = id;
 145         cbcp_recvreq(us, inp, len);
 146         break;
 147
 148     case CBCP_RESP:
 149         syslog(LOG_DEBUG, "CBCP_RESP received");
 150         break;
 151
 152     case CBCP_ACK:
 153         if (id != us->us_id)
 154             syslog(LOG_DEBUG, "id doesn't match: expected %d recv %d",
 155                    us->us_id, id);
 156
 157         cbcp_recvack(us, inp, len);
 158         break;
 159
 160     default:
 161         break;
 162     }
 163 }
 164
 165 /* protocol was rejected by foe */
 166 void cbcp_protrej(int iface)
 167 {
 168 }
 169
 170 char *cbcp_codenames[] = {
 171     "Request", "Response", "Ack"
 172 };
 173
 174 char *cbcp_optionnames[] = {
 175     "NoCallback",
 176     "UserDefined",
 177     "AdminDefined",
 178     "List"
 179 };
 180
 181 /* pretty print a packet */
 182 static int
 183 cbcp_printpkt(p, plen, printer, arg)
 184     u_char *p;
 185     int plen;
 186     void (*printer)(void *, char *, ...);
 187     void *arg;
 188 {
 189     int code, opt, id, len, olen, delay;
 190     u_char *pstart;
 191
 192     if (plen < HEADERLEN)
 193         return 0;
 194     pstart = p;
 195     GETCHAR(code, p);
 196     GETCHAR(id, p);
 197     GETSHORT(len, p);
 198     if (len < HEADERLEN || len > plen)
 199         return 0;
 200
 201     if (code >= 1 && code <= sizeof(cbcp_codenames) / sizeof(char *))
 202         printer(arg, " %s", cbcp_codenames[code-1]);
 203     else
 204         printer(arg, " code=0x%x", code);
 205
 206     printer(arg, " id=0x%x", id);
 207     len -= HEADERLEN;
 208
 209     switch (code) {
 210     case CBCP_REQ:
 211     case CBCP_RESP:
 212     case CBCP_ACK:
 213         while(len >= 2) {
 214             GETCHAR(opt, p);
 215             GETCHAR(olen, p);
 216
 217             if (olen < 2 || olen > len) {
 218                 break;
 219             }
 220
 221             printer(arg, " <");
 222             len -= olen;
 223
 224             if (opt >= 1 && opt <= sizeof(cbcp_optionnames) / sizeof(char *))
 225                 printer(arg, " %s", cbcp_optionnames[opt-1]);
 226             else
 227                 printer(arg, " option=0x%x", opt);
 228
 229             if (olen > 2) {
 230                 GETCHAR(delay, p);
 231                 printer(arg, " delay = %d", delay);
 232             }
 233
 234             if (olen > 3) {
 235                 int addrt;
 236                 char str[256];
 237
 238                 GETCHAR(addrt, p);
 239                 memcpy(str, p, olen - 4);
 240                 str[olen - 4] = 0;
 241                 printer(arg, " number = %s", str);
 242             }
 243             printer(arg, ">");
 244             break;
 245         }
 246
 247     default:
 248         break;
 249     }
 250
 251     for (; len > 0; --len) {
 252         GETCHAR(code, p);
 253         printer(arg, " %.2x", code);
 254     }
 255
 256     return p - pstart;
 257 }
 258
 259 /* received CBCP request */
 260 static void
 261 cbcp_recvreq(us, pckt, pcktlen)
 262     cbcp_state *us;
 263     char *pckt;
 264     int pcktlen;
 265 {
 266     u_char type, opt_len, delay, addr_type;
 267     char address[256];
 268     int len = pcktlen;
 269
 270     address[0] = 0;
 271
 272     while (len > 1) {
 273         syslog(LOG_DEBUG, "length: %d", len);
 274
 275         GETCHAR(type, pckt);
 276         GETCHAR(opt_len, pckt);
 277
 278         if (len < opt_len)
 279                 break;
 280         len -= opt_len;
 281
 282         if (opt_len > 2)
 283             GETCHAR(delay, pckt);
 284
 285         us->us_allowed |= (1 << type);
 286
 287         switch(type) {
 288         case CB_CONF_NO:
 289             syslog(LOG_DEBUG, "no callback allowed");
 290             break;
 291
 292         case CB_CONF_USER:
 293             syslog(LOG_DEBUG, "user callback allowed");
 294             if (opt_len > 4) {
 295                 GETCHAR(addr_type, pckt);
 296                 memcpy(address, pckt, opt_len - 4);
 297                 address[opt_len - 4] = 0;
 298                 if (address[0])
 299                     syslog(LOG_DEBUG, "address: %s", address);
 300             }
 301             break;
 302
 303         case CB_CONF_ADMIN:
 304             syslog(LOG_DEBUG, "user admin defined allowed");
 305             break;
 306
 307         case CB_CONF_LIST:
 308             break;
 309         }
 310     }
 311
 312     cbcp_resp(us);
 313 }
 314
 315 static void
 316 cbcp_resp(us)
 317     cbcp_state *us;
 318 {
 319     u_char cb_type;
 320     u_char buf[256];
 321     u_char *bufp = buf;
 322     int len = 0;
 323
 324     cb_type = us->us_allowed & us->us_type;
 325     syslog(LOG_DEBUG, "cbcp_resp cb_type=%d", cb_type);
 326
 327 #if 0
 328     if (!cb_type)
 329         lcp_down(us->us_unit);
 330 #endif
 331
 332     if (cb_type & ( 1 << CB_CONF_USER ) ) {
 333         syslog(LOG_DEBUG, "cbcp_resp CONF_USER");
 334         PUTCHAR(CB_CONF_USER, bufp);
 335         len = 3 + 1 + strlen(us->us_number) + 1;
 336         PUTCHAR(len , bufp);
 337         PUTCHAR(5, bufp); /* delay */
 338         PUTCHAR(1, bufp);
 339         BCOPY(us->us_number, bufp, strlen(us->us_number) + 1);
 340         cbcp_send(us, CBCP_RESP, buf, len);
 341         return;
 342     }
 343
 344     if (cb_type & ( 1 << CB_CONF_ADMIN ) ) {
 345         syslog(LOG_DEBUG, "cbcp_resp CONF_ADMIN");
 346         PUTCHAR(CB_CONF_ADMIN, bufp);
 347         len = 3;
 348         PUTCHAR(len, bufp);
 349         PUTCHAR(5, bufp); /* delay */
 350         cbcp_send(us, CBCP_RESP, buf, len);
 351         return;
 352     }
 353
 354     if (cb_type & ( 1 << CB_CONF_NO ) ) {
 355         syslog(LOG_DEBUG, "cbcp_resp CONF_NO");
 356         PUTCHAR(CB_CONF_NO, bufp);
 357         len = 2;
 358         PUTCHAR(len , bufp);
 359         cbcp_send(us, CBCP_RESP, buf, len);
 360         (*ipcp_protent.open)(us->us_unit);
 361         return;
 362     }
 363 }
 364
 365 static void
 366 cbcp_send(us, code, buf, len)
 367     cbcp_state *us;
 368     u_char code;
 369     u_char *buf;
 370     int len;
 371 {
 372     u_char *outp;
 373     int outlen;
 374
 375     outp = outpacket_buf;
 376
 377     outlen = 4 + len;
 378
 379     MAKEHEADER(outp, PPP_CBCP);
 380
 381     PUTCHAR(code, outp);
 382     PUTCHAR(us->us_id, outp);
 383     PUTSHORT(outlen, outp);
 384
 385     if (len)
 386         BCOPY(buf, outp, len);
 387
 388     output(us->us_unit, outpacket_buf, outlen + PPP_HDRLEN);
 389 }
 390
 391 static void
 392 cbcp_recvack(us, pckt, len)
 393     cbcp_state *us;
 394     char *pckt;
 395     int len;
 396 {
 397     u_char type, delay, addr_type;
 398     int opt_len;
 399     char address[256];
 400
 401     if (len > 1) {
 402         GETCHAR(type, pckt);
 403         GETCHAR(opt_len, pckt);
 404
 405         if (opt_len > len)
 406                 return;
 407
 408         if (opt_len > 2)
 409             GETCHAR(delay, pckt);
 410
 411         if (opt_len > 4) {
 412             GETCHAR(addr_type, pckt);
 413             memcpy(address, pckt, opt_len - 4);
 414             address[opt_len - 4] = 0;
 415             if (address[0])
 416                 syslog(LOG_DEBUG, "peer will call: %s", address);
 417         }
 418     }
 419
 420     cbcp_up(us);
 421 }
 422
 423 extern int persist;
 424
 425 /* ok peer will do callback */
 426 static void
 427 cbcp_up(us)
 428     cbcp_state *us;
 429 {
 430     persist = 0;
 431     lcp_close(0, "Call me back, please");
 432 }