usr.sbin/ppp/cbcp.c

   1 /*-
   2  * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * $FreeBSD$
  27  */
  28
  29 #include <sys/param.h>
  30
  31 #ifdef __FreeBSD__
  32 #include <netinet/in.h>
  33 #endif
  34 #include <sys/un.h>
  35
  36 #include <string.h>
  37 #include <termios.h>
  38
  39 #include "layer.h"
  40 #include "defs.h"
  41 #include "log.h"
  42 #include "timer.h"
  43 #include "descriptor.h"
  44 #include "lqr.h"
  45 #include "mbuf.h"
  46 #include "fsm.h"
  47 #include "throughput.h"
  48 #include "hdlc.h"
  49 #include "lcp.h"
  50 #include "ccp.h"
  51 #include "link.h"
  52 #include "async.h"
  53 #include "physical.h"
  54 #include "proto.h"
  55 #include "cbcp.h"
  56 #include "mp.h"
  57 #include "chat.h"
  58 #include "auth.h"
  59 #include "chap.h"
  60 #include "datalink.h"
  61
  62 void
  63 cbcp_Init(struct cbcp *cbcp, struct physical *p)
  64 {
  65   cbcp->required = 0;
  66   cbcp->fsm.state = CBCP_CLOSED;
  67   cbcp->fsm.id = 0;
  68   cbcp->fsm.delay = 0;
  69   *cbcp->fsm.phone = '\0';
  70   memset(&cbcp->fsm.timer, '\0', sizeof cbcp->fsm.timer);
  71   cbcp->p = p;
  72 }
  73
  74 static void cbcp_SendReq(struct cbcp *);
  75 static void cbcp_SendResponse(struct cbcp *);
  76 static void cbcp_SendAck(struct cbcp *);
  77
  78 static void
  79 cbcp_Timeout(void *v)
  80 {
  81   struct cbcp *cbcp = (struct cbcp *)v;
  82
  83   timer_Stop(&cbcp->fsm.timer);
  84   if (cbcp->fsm.restart) {
  85     switch (cbcp->fsm.state) {
  86       case CBCP_CLOSED:
  87       case CBCP_STOPPED:
  88         log_Printf(LogCBCP, "%s: Urk - unexpected CBCP timeout !\n",
  89                    cbcp->p->dl->name);
  90         break;
  91
  92       case CBCP_REQSENT:
  93         cbcp_SendReq(cbcp);
  94         break;
  95       case CBCP_RESPSENT:
  96         cbcp_SendResponse(cbcp);
  97         break;
  98       case CBCP_ACKSENT:
  99         cbcp_SendAck(cbcp);
 100         break;
 101     }
 102   } else {
 103     const char *missed;
 104
 105     switch (cbcp->fsm.state) {
 106       case CBCP_STOPPED:
 107         missed = "REQ";
 108         break;
 109       case CBCP_REQSENT:
 110         missed = "RESPONSE";
 111         break;
 112       case CBCP_RESPSENT:
 113         missed = "ACK";
 114         break;
 115       case CBCP_ACKSENT:
 116         missed = "Terminate REQ";
 117         break;
 118       default:
 119         log_Printf(LogCBCP, "%s: Urk - unexpected CBCP timeout !\n",
 120                    cbcp->p->dl->name);
 121         missed = NULL;
 122         break;
 123     }
 124     if (missed)
 125       log_Printf(LogCBCP, "%s: Timeout waiting for peer %s\n",
 126                  cbcp->p->dl->name, missed);
 127     datalink_CBCPFailed(cbcp->p->dl);
 128   }
 129 }
 130
 131 static void
 132 cbcp_StartTimer(struct cbcp *cbcp, int timeout)
 133 {
 134   timer_Stop(&cbcp->fsm.timer);
 135   cbcp->fsm.timer.func = cbcp_Timeout;
 136   cbcp->fsm.timer.name = "cbcp";
 137   cbcp->fsm.timer.load = timeout * SECTICKS;
 138   cbcp->fsm.timer.arg = cbcp;
 139   timer_Start(&cbcp->fsm.timer);
 140 }
 141
 142 #define CBCP_CLOSED     (0)     /* Not in use */
 143 #define CBCP_STOPPED    (1)     /* Waiting for a REQ */
 144 #define CBCP_REQSENT    (2)     /* Waiting for a RESP */
 145 #define CBCP_RESPSENT   (3)     /* Waiting for an ACK */
 146 #define CBCP_ACKSENT    (4)     /* Waiting for an LCP Term REQ */
 147
 148 static const char * const cbcpname[] = {
 149   "closed", "stopped", "req-sent", "resp-sent", "ack-sent"
 150 };
 151
 152 static const char *
 153 cbcpstate(unsigned s)
 154 {
 155   if (s < sizeof cbcpname / sizeof cbcpname[0])
 156     return cbcpname[s];
 157   return HexStr(s, NULL, 0);
 158 }
 159
 160 static void
 161 cbcp_NewPhase(struct cbcp *cbcp, int new)
 162 {
 163   if (cbcp->fsm.state != new) {
 164     log_Printf(LogCBCP, "%s: State change %s --> %s\n", cbcp->p->dl->name,
 165                cbcpstate(cbcp->fsm.state), cbcpstate(new));
 166     cbcp->fsm.state = new;
 167   }
 168 }
 169
 170 struct cbcp_header {
 171   u_char code;
 172   u_char id;
 173   u_int16_t length;     /* Network byte order */
 174 };
 175
 176
 177 /* cbcp_header::code values */
 178 #define CBCP_REQ        (1)
 179 #define CBCP_RESPONSE   (2)
 180 #define CBCP_ACK        (3)
 181
 182 struct cbcp_data {
 183   u_char type;
 184   u_char length;
 185   u_char delay;
 186   char addr_start[253]; /* max cbcp_data length 255 + 1 for NULL */
 187 };
 188
 189 /* cbcp_data::type values */
 190 #define CBCP_NONUM      (1)
 191 #define CBCP_CLIENTNUM  (2)
 192 #define CBCP_SERVERNUM  (3)
 193 #define CBCP_LISTNUM    (4)
 194
 195 static void
 196 cbcp_Output(struct cbcp *cbcp, u_char code, struct cbcp_data *data)
 197 {
 198   struct cbcp_header *head;
 199   struct mbuf *bp;
 200
 201   bp = m_get(sizeof *head + data->length, MB_CBCPOUT);
 202   head = (struct cbcp_header *)MBUF_CTOP(bp);
 203   head->code = code;
 204   head->id = cbcp->fsm.id;
 205   head->length = htons(sizeof *head + data->length);
 206   memcpy(MBUF_CTOP(bp) + sizeof *head, data, data->length);
 207   log_DumpBp(LogDEBUG, "cbcp_Output", bp);
 208   link_PushPacket(&cbcp->p->link, bp, cbcp->p->dl->bundle,
 209                   LINK_QUEUES(&cbcp->p->link) - 1, PROTO_CBCP);
 210 }
 211
 212 static const char *
 213 cbcp_data_Type(unsigned type)
 214 {
 215   static const char * const types[] = {
 216     "No callback", "User-spec", "Server-spec", "list"
 217   };
 218
 219   if (type < 1 || type > sizeof types / sizeof types[0])
 220     return HexStr(type, NULL, 0);
 221   return types[type-1];
 222 }
 223
 224 struct cbcp_addr {
 225   u_char type;
 226   char addr[sizeof ((struct cbcp_data *)0)->addr_start - 1];    /* ASCIIZ */
 227 };
 228
 229 /* cbcp_data::type values */
 230 #define CBCP_ADDR_PSTN  (1)
 231
 232 static void
 233 cbcp_data_Show(struct cbcp_data *data)
 234 {
 235   struct cbcp_addr *addr;
 236   char *end;
 237
 238   addr = (struct cbcp_addr *)data->addr_start;
 239   end = (char *)data + data->length;
 240   *end = '\0';
 241
 242   log_Printf(LogCBCP, " TYPE %s\n", cbcp_data_Type(data->type));
 243   if ((char *)&data->delay < end) {
 244     log_Printf(LogCBCP, " DELAY %d\n", data->delay);
 245     while (addr->addr < end) {
 246       if (addr->type == CBCP_ADDR_PSTN)
 247         log_Printf(LogCBCP, " ADDR %s\n", addr->addr);
 248       else
 249         log_Printf(LogCBCP, " ADDR type %d ??\n", (int)addr->type);
 250       addr = (struct cbcp_addr *)(addr->addr + strlen(addr->addr) + 1);
 251     }
 252   }
 253 }
 254
 255 static void
 256 cbcp_SendReq(struct cbcp *cbcp)
 257 {
 258   struct cbcp_data data;
 259   struct cbcp_addr *addr;
 260   char list[sizeof cbcp->fsm.phone], *next;
 261   int len, max;
 262
 263   /* Only callees send REQs */
 264
 265   log_Printf(LogCBCP, "%s: SendReq(%d) state = %s\n", cbcp->p->dl->name,
 266              cbcp->fsm.id, cbcpstate(cbcp->fsm.state));
 267   data.type = cbcp->fsm.type;
 268   data.delay = 0;
 269   strncpy(list, cbcp->fsm.phone, sizeof list - 1);
 270   list[sizeof list - 1] = '\0';
 271
 272   switch (data.type) {
 273     case CBCP_CLIENTNUM:
 274       addr = (struct cbcp_addr *)data.addr_start;
 275       addr->type = CBCP_ADDR_PSTN;
 276       *addr->addr = '\0';
 277       data.length = addr->addr - (char *)&data;
 278       break;
 279
 280     case CBCP_LISTNUM:
 281       addr = (struct cbcp_addr *)data.addr_start;
 282       for (next = strtok(list, ","); next; next = strtok(NULL, ",")) {
 283         len = strlen(next);
 284         max = data.addr_start + sizeof data.addr_start - addr->addr - 1;
 285         if (len <= max) {
 286           addr->type = CBCP_ADDR_PSTN;
 287           strncpy(addr->addr, next, sizeof addr->addr - 1);
 288           addr->addr[sizeof addr->addr - 1] = '\0';
 289           addr = (struct cbcp_addr *)((char *)addr + len + 2);
 290         } else
 291           log_Printf(LogWARN, "CBCP ADDR \"%s\" skipped - packet too large\n",
 292                      next);
 293       }
 294       data.length = (char *)addr - (char *)&data;
 295       break;
 296
 297     case CBCP_SERVERNUM:
 298       data.length = data.addr_start - (char *)&data;
 299       break;
 300
 301     default:
 302       data.length = (char *)&data.delay - (char *)&data;
 303       break;
 304   }
 305
 306   cbcp_data_Show(&data);
 307   cbcp_Output(cbcp, CBCP_REQ, &data);
 308   cbcp->fsm.restart--;
 309   cbcp_StartTimer(cbcp, cbcp->fsm.delay);
 310   cbcp_NewPhase(cbcp, CBCP_REQSENT);            /* Wait for a RESPONSE */
 311 }
 312
 313 void
 314 cbcp_Up(struct cbcp *cbcp)
 315 {
 316   struct lcp *lcp = &cbcp->p->link.lcp;
 317
 318   cbcp->fsm.delay = cbcp->p->dl->cfg.cbcp.delay;
 319   if (*cbcp->p->dl->peer.authname == '\0' ||
 320       !auth_SetPhoneList(cbcp->p->dl->peer.authname, cbcp->fsm.phone,
 321                          sizeof cbcp->fsm.phone)) {
 322     strncpy(cbcp->fsm.phone, cbcp->p->dl->cfg.cbcp.phone,
 323             sizeof cbcp->fsm.phone - 1);
 324     cbcp->fsm.phone[sizeof cbcp->fsm.phone - 1] = '\0';
 325   }
 326
 327   if (lcp->want_callback.opmask) {
 328     if (*cbcp->fsm.phone == '\0')
 329       cbcp->fsm.type = CBCP_NONUM;
 330     else if (!strcmp(cbcp->fsm.phone, "*")) {
 331       cbcp->fsm.type = CBCP_SERVERNUM;
 332       *cbcp->fsm.phone = '\0';
 333     } else
 334       cbcp->fsm.type = CBCP_CLIENTNUM;
 335     cbcp_NewPhase(cbcp, CBCP_STOPPED);          /* Wait for a REQ */
 336     cbcp_StartTimer(cbcp, cbcp->fsm.delay * DEF_FSMTRIES);
 337   } else {
 338     if (*cbcp->fsm.phone == '\0')
 339       cbcp->fsm.type = CBCP_NONUM;
 340     else if (!strcmp(cbcp->fsm.phone, "*")) {
 341       cbcp->fsm.type = CBCP_CLIENTNUM;
 342       *cbcp->fsm.phone = '\0';
 343     } else if (strchr(cbcp->fsm.phone, ','))
 344       cbcp->fsm.type = CBCP_LISTNUM;
 345     else
 346       cbcp->fsm.type = CBCP_SERVERNUM;
 347     cbcp->fsm.restart = DEF_FSMTRIES;
 348     cbcp_SendReq(cbcp);
 349   }
 350 }
 351
 352 static int
 353 cbcp_AdjustResponse(struct cbcp *cbcp, struct cbcp_data *data)
 354 {
 355   /*
 356    * We've received a REQ (data).  Adjust our reponse (cbcp->fsm.*)
 357    * so that we (hopefully) agree with the peer
 358    */
 359   struct cbcp_addr *addr;
 360
 361   switch (data->type) {
 362     case CBCP_NONUM:
 363       if (cbcp->p->dl->cfg.callback.opmask & CALLBACK_BIT(CALLBACK_NONE))
 364         /*
 365          * if ``none'' is a configured callback possibility
 366          * (ie, ``set callback cbcp none''), go along with the callees
 367          * request
 368          */
 369         cbcp->fsm.type = CBCP_NONUM;
 370
 371       /*
 372        * Otherwise, we send our desired response anyway.  This seems to be
 373        * what Win95 does - although I can't find this behaviour documented
 374        * in the CBCP spec....
 375        */
 376
 377       return 1;
 378
 379     case CBCP_CLIENTNUM:
 380       if (cbcp->fsm.type == CBCP_CLIENTNUM) {
 381         char *ptr;
 382
 383         if (data->length > data->addr_start - (char *)data) {
 384           /*
 385            * The peer has given us an address type spec - make sure we
 386            * understand !
 387            */
 388           addr = (struct cbcp_addr *)data->addr_start;
 389           if (addr->type != CBCP_ADDR_PSTN) {
 390             log_Printf(LogPHASE, "CBCP: Unrecognised address type %d !\n",
 391                        (int)addr->type);
 392             return 0;
 393           }
 394         }
 395         /* we accept the REQ even if the peer didn't specify an addr->type */
 396         ptr = strchr(cbcp->fsm.phone, ',');
 397         if (ptr)
 398           *ptr = '\0';          /* Just use the first number in our list */
 399         return 1;
 400       }
 401       log_Printf(LogPHASE, "CBCP: no number to pass to the peer !\n");
 402       return 0;
 403
 404     case CBCP_SERVERNUM:
 405       if (cbcp->fsm.type == CBCP_SERVERNUM) {
 406         *cbcp->fsm.phone = '\0';
 407         return 1;
 408       }
 409       if (data->length > data->addr_start - (char *)data) {
 410         /*
 411          * This violates the spec, but if the peer has told us the
 412          * number it wants to call back, take advantage of this fact
 413          * and allow things to proceed if we've specified the same
 414          * number
 415          */
 416         addr = (struct cbcp_addr *)data->addr_start;
 417         if (addr->type != CBCP_ADDR_PSTN) {
 418           log_Printf(LogPHASE, "CBCP: Unrecognised address type %d !\n",
 419                      (int)addr->type);
 420           return 0;
 421         } else if (cbcp->fsm.type == CBCP_CLIENTNUM) {
 422           /*
 423            * If the peer's insisting on deciding the number, make sure
 424            * it's one of the ones in our list.  If it is, let the peer
 425            * think it's in control :-)
 426            */
 427           char list[sizeof cbcp->fsm.phone], *next;
 428
 429           strncpy(list, cbcp->fsm.phone, sizeof list - 1);
 430           list[sizeof list - 1] = '\0';
 431           for (next = strtok(list, ","); next; next = strtok(NULL, ","))
 432             if (!strcmp(next, addr->addr)) {
 433               cbcp->fsm.type = CBCP_SERVERNUM;
 434               strcpy(cbcp->fsm.phone, next);
 435               return 1;
 436             }
 437         }
 438       }
 439       log_Printf(LogPHASE, "CBCP: Peer won't allow local decision !\n");
 440       return 0;
 441
 442     case CBCP_LISTNUM:
 443       if (cbcp->fsm.type == CBCP_CLIENTNUM || cbcp->fsm.type == CBCP_LISTNUM) {
 444         /*
 445          * Search through ``data''s addresses and see if cbcp->fsm.phone
 446          * contains any of them
 447          */
 448         char list[sizeof cbcp->fsm.phone], *next, *end;
 449
 450         addr = (struct cbcp_addr *)data->addr_start;
 451         end = (char *)data + data->length;
 452
 453         while (addr->addr < end) {
 454           if (addr->type == CBCP_ADDR_PSTN) {
 455             strncpy(list, cbcp->fsm.phone, sizeof list - 1);
 456             list[sizeof list - 1] = '\0';
 457             for (next = strtok(list, ","); next; next = strtok(NULL, ","))
 458               if (!strcmp(next, addr->addr)) {
 459                 cbcp->fsm.type = CBCP_LISTNUM;
 460                 strcpy(cbcp->fsm.phone, next);
 461                 return 1;
 462               }
 463           } else
 464             log_Printf(LogCBCP, "Warning: Unrecognised address type %d !\n",
 465                        (int)addr->type);
 466           addr = (struct cbcp_addr *)(addr->addr + strlen(addr->addr) + 1);
 467         }
 468       }
 469       log_Printf(LogPHASE, "CBCP: no good number to pass to the peer !\n");
 470       return 0;
 471   }
 472
 473   log_Printf(LogCBCP, "Unrecognised REQ type %d !\n", (int)data->type);
 474   return 0;
 475 }
 476
 477 static void
 478 cbcp_SendResponse(struct cbcp *cbcp)
 479 {
 480   struct cbcp_data data;
 481   struct cbcp_addr *addr;
 482
 483   /* Only callers send RESPONSEs */
 484
 485   log_Printf(LogCBCP, "%s: SendResponse(%d) state = %s\n", cbcp->p->dl->name,
 486              cbcp->fsm.id, cbcpstate(cbcp->fsm.state));
 487
 488   data.type = cbcp->fsm.type;
 489   data.delay = cbcp->fsm.delay;
 490   addr = (struct cbcp_addr *)data.addr_start;
 491   if (data.type == CBCP_NONUM)
 492     data.length = (char *)&data.delay - (char *)&data;
 493   else if (*cbcp->fsm.phone) {
 494     addr->type = CBCP_ADDR_PSTN;
 495     strncpy(addr->addr, cbcp->fsm.phone, sizeof addr->addr - 1);
 496     addr->addr[sizeof addr->addr - 1] = '\0';
 497     data.length = (addr->addr + strlen(addr->addr) + 1) - (char *)&data;
 498   } else
 499     data.length = data.addr_start - (char *)&data;
 500
 501   cbcp_data_Show(&data);
 502   cbcp_Output(cbcp, CBCP_RESPONSE, &data);
 503   cbcp->fsm.restart--;
 504   cbcp_StartTimer(cbcp, cbcp->fsm.delay);
 505   cbcp_NewPhase(cbcp, CBCP_RESPSENT);   /* Wait for an ACK */
 506 }
 507
 508 /* What to do after checking an incoming response */
 509 #define CBCP_ACTION_DOWN (0)
 510 #define CBCP_ACTION_REQ (1)
 511 #define CBCP_ACTION_ACK (2)
 512
 513 static int
 514 cbcp_CheckResponse(struct cbcp *cbcp, struct cbcp_data *data)
 515 {
 516   /*
 517    * We've received a RESPONSE (data).  Check if it agrees with
 518    * our REQ (cbcp->fsm)
 519    */
 520   struct cbcp_addr *addr;
 521
 522   addr = (struct cbcp_addr *)data->addr_start;
 523
 524   if (data->type == cbcp->fsm.type) {
 525     switch (cbcp->fsm.type) {
 526       case CBCP_NONUM:
 527         return CBCP_ACTION_ACK;
 528
 529       case CBCP_CLIENTNUM:
 530         if ((char *)data + data->length <= addr->addr)
 531           log_Printf(LogPHASE, "CBCP: peer didn't respond with a number !\n");
 532         else if (addr->type != CBCP_ADDR_PSTN)
 533           log_Printf(LogPHASE, "CBCP: Unrecognised address type %d !\n",
 534                      addr->type);
 535         else {
 536           strncpy(cbcp->fsm.phone, addr->addr, sizeof cbcp->fsm.phone - 1);
 537           cbcp->fsm.phone[sizeof cbcp->fsm.phone - 1] = '\0';
 538           cbcp->fsm.delay = data->delay;
 539           return CBCP_ACTION_ACK;
 540         }
 541         return CBCP_ACTION_DOWN;
 542
 543       case CBCP_SERVERNUM:
 544         cbcp->fsm.delay = data->delay;
 545         return CBCP_ACTION_ACK;
 546
 547       case CBCP_LISTNUM:
 548         if ((char *)data + data->length <= addr->addr)
 549           log_Printf(LogPHASE, "CBCP: peer didn't respond with a number !\n");
 550         else if (addr->type != CBCP_ADDR_PSTN)
 551           log_Printf(LogPHASE, "CBCP: Unrecognised address type %d !\n",
 552                      addr->type);
 553         else {
 554           char list[sizeof cbcp->fsm.phone], *next;
 555
 556           strncpy(list, cbcp->fsm.phone, sizeof list - 1);
 557           list[sizeof list - 1] = '\0';
 558           for (next = strtok(list, ","); next; next = strtok(NULL, ","))
 559             if (!strcmp(addr->addr, next)) {
 560               strcpy(cbcp->fsm.phone, next);
 561               cbcp->fsm.delay = data->delay;
 562               return CBCP_ACTION_ACK;
 563             }
 564           log_Printf(LogPHASE, "CBCP: peer didn't respond with a "
 565                      "valid number !\n");
 566         }
 567         return CBCP_ACTION_DOWN;
 568     }
 569     log_Printf(LogPHASE, "Internal CBCP error - agreed on %d !\n",
 570                (int)cbcp->fsm.type);
 571     return CBCP_ACTION_DOWN;
 572   } else if (data->type == CBCP_NONUM && cbcp->fsm.type == CBCP_CLIENTNUM) {
 573     /*
 574      * Client doesn't want CBCP after all....
 575      * We only allow this when ``set cbcp *'' has been specified.
 576      */
 577     cbcp->fsm.type = CBCP_NONUM;
 578     return CBCP_ACTION_ACK;
 579   }
 580   log_Printf(LogCBCP, "Invalid peer RESPONSE\n");
 581   return CBCP_ACTION_REQ;
 582 }
 583
 584 static void
 585 cbcp_SendAck(struct cbcp *cbcp)
 586 {
 587   struct cbcp_data data;
 588   struct cbcp_addr *addr;
 589
 590   /* Only callees send ACKs */
 591
 592   log_Printf(LogCBCP, "%s: SendAck(%d) state = %s\n", cbcp->p->dl->name,
 593              cbcp->fsm.id, cbcpstate(cbcp->fsm.state));
 594
 595   data.type = cbcp->fsm.type;
 596   switch (data.type) {
 597     case CBCP_NONUM:
 598       data.length = (char *)&data.delay - (char *)&data;
 599       break;
 600     case CBCP_CLIENTNUM:
 601       addr = (struct cbcp_addr *)data.addr_start;
 602       addr->type = CBCP_ADDR_PSTN;
 603       strncpy(addr->addr, cbcp->fsm.phone, sizeof addr->addr - 1);
 604       addr->addr[sizeof addr->addr - 1] = '\0';
 605       data.delay = cbcp->fsm.delay;
 606       data.length = addr->addr + strlen(addr->addr) + 1 - (char *)&data;
 607       break;
 608     default:
 609       data.delay = cbcp->fsm.delay;
 610       data.length = data.addr_start - (char *)&data;
 611       break;
 612   }
 613
 614   cbcp_data_Show(&data);
 615   cbcp_Output(cbcp, CBCP_ACK, &data);
 616   cbcp->fsm.restart--;
 617   cbcp_StartTimer(cbcp, cbcp->fsm.delay);
 618   cbcp_NewPhase(cbcp, CBCP_ACKSENT);    /* Wait for an ACK */
 619 }
 620
 621 extern struct mbuf *
 622 cbcp_Input(struct bundle *bundle __unused, struct link *l, struct mbuf *bp)
 623 {
 624   struct physical *p = link2physical(l);
 625   struct cbcp_header *head;
 626   struct cbcp_data *data;
 627   struct cbcp *cbcp = &p->dl->cbcp;
 628   size_t len;
 629
 630   if (p == NULL) {
 631     log_Printf(LogERROR, "cbcp_Input: Not a physical link - dropped\n");
 632     m_freem(bp);
 633     return NULL;
 634   }
 635
 636   bp = m_pullup(bp);
 637   len = m_length(bp);
 638   if (len < sizeof(struct cbcp_header)) {
 639     m_freem(bp);
 640     return NULL;
 641   }
 642   head = (struct cbcp_header *)MBUF_CTOP(bp);
 643   if (ntohs(head->length) != len) {
 644     log_Printf(LogWARN, "Corrupt CBCP packet (code %d, length %u not %zu)"
 645                " - ignored\n", head->code, ntohs(head->length), len);
 646     m_freem(bp);
 647     return NULL;
 648   }
 649   m_settype(bp, MB_CBCPIN);
 650
 651   /* XXX check the id */
 652
 653   bp->m_offset += sizeof(struct cbcp_header);
 654   bp->m_len -= sizeof(struct cbcp_header);
 655   data = (struct cbcp_data *)MBUF_CTOP(bp);
 656
 657   switch (head->code) {
 658     case CBCP_REQ:
 659       log_Printf(LogCBCP, "%s: RecvReq(%d) state = %s\n",
 660                  p->dl->name, head->id, cbcpstate(cbcp->fsm.state));
 661       cbcp_data_Show(data);
 662       if (cbcp->fsm.state == CBCP_STOPPED || cbcp->fsm.state == CBCP_RESPSENT) {
 663         timer_Stop(&cbcp->fsm.timer);
 664         if (cbcp_AdjustResponse(cbcp, data)) {
 665           cbcp->fsm.restart = DEF_FSMTRIES;
 666           cbcp->fsm.id = head->id;
 667           cbcp_SendResponse(cbcp);
 668         } else
 669           datalink_CBCPFailed(cbcp->p->dl);
 670       } else
 671         log_Printf(LogCBCP, "%s: unexpected REQ dropped\n", p->dl->name);
 672       break;
 673
 674     case CBCP_RESPONSE:
 675       log_Printf(LogCBCP, "%s: RecvResponse(%d) state = %s\n",
 676                  p->dl->name, head->id, cbcpstate(cbcp->fsm.state));
 677       cbcp_data_Show(data);
 678       if (cbcp->fsm.id != head->id) {
 679         log_Printf(LogCBCP, "Warning: Expected id was %d, not %d\n",
 680                    cbcp->fsm.id, head->id);
 681         cbcp->fsm.id = head->id;
 682       }
 683       if (cbcp->fsm.state == CBCP_REQSENT || cbcp->fsm.state == CBCP_ACKSENT) {
 684         timer_Stop(&cbcp->fsm.timer);
 685         switch (cbcp_CheckResponse(cbcp, data)) {
 686           case CBCP_ACTION_REQ:
 687             cbcp_SendReq(cbcp);
 688             break;
 689
 690           case CBCP_ACTION_ACK:
 691             cbcp->fsm.restart = DEF_FSMTRIES;
 692             cbcp_SendAck(cbcp);
 693             if (cbcp->fsm.type == CBCP_NONUM) {
 694               /*
 695                * Don't change state in case the peer doesn't get our ACK,
 696                * just bring the layer up.
 697                */
 698               timer_Stop(&cbcp->fsm.timer);
 699               datalink_NCPUp(cbcp->p->dl);
 700             }
 701             break;
 702
 703           default:
 704             datalink_CBCPFailed(cbcp->p->dl);
 705             break;
 706         }
 707       } else
 708         log_Printf(LogCBCP, "%s: unexpected RESPONSE dropped\n", p->dl->name);
 709       break;
 710
 711     case CBCP_ACK:
 712       log_Printf(LogCBCP, "%s: RecvAck(%d) state = %s\n",
 713                  p->dl->name, head->id, cbcpstate(cbcp->fsm.state));
 714       cbcp_data_Show(data);
 715       if (cbcp->fsm.id != head->id) {
 716         log_Printf(LogCBCP, "Warning: Expected id was %d, not %d\n",
 717                    cbcp->fsm.id, head->id);
 718         cbcp->fsm.id = head->id;
 719       }
 720       if (cbcp->fsm.type == CBCP_NONUM) {
 721         /*
 722          * Don't change state in case the peer doesn't get our ACK,
 723          * just bring the layer up.
 724          */
 725         timer_Stop(&cbcp->fsm.timer);
 726         datalink_NCPUp(cbcp->p->dl);
 727       } else if (cbcp->fsm.state == CBCP_RESPSENT) {
 728         timer_Stop(&cbcp->fsm.timer);
 729         datalink_CBCPComplete(cbcp->p->dl);
 730         log_Printf(LogPHASE, "%s: CBCP: Peer will dial back\n", p->dl->name);
 731       } else
 732         log_Printf(LogCBCP, "%s: unexpected ACK dropped\n", p->dl->name);
 733       break;
 734
 735     default:
 736       log_Printf(LogWARN, "Unrecognised CBCP packet (code %d, length %zd)\n",
 737                head->code, len);
 738       break;
 739   }
 740
 741   m_freem(bp);
 742   return NULL;
 743 }
 744
 745 void
 746 cbcp_Down(struct cbcp *cbcp)
 747 {
 748   timer_Stop(&cbcp->fsm.timer);
 749   cbcp_NewPhase(cbcp, CBCP_CLOSED);
 750   cbcp->required = 0;
 751 }
 752
 753 void
 754 cbcp_ReceiveTerminateReq(struct physical *p)
 755 {
 756   if (p->dl->cbcp.fsm.state == CBCP_ACKSENT) {
 757     /* Don't change our state in case the peer doesn't get the ACK */
 758     p->dl->cbcp.required = 1;
 759     log_Printf(LogPHASE, "%s: CBCP: Will dial back on %s\n", p->dl->name,
 760                p->dl->cbcp.fsm.phone);
 761   } else
 762     cbcp_NewPhase(&p->dl->cbcp, CBCP_CLOSED);
 763 }