1 /* 2 * ccp.c - PPP Compression Control Protocol. 3 * 4 * Copyright (c) 1994-2002 Paul Mackerras. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. The name(s) of the authors of this software must not be used to 14 * endorse or promote products derived from this software without 15 * prior written permission. 16 * 17 * 3. Redistributions of any form whatsoever must retain the following 18 * acknowledgment: 19 * "This product includes software developed by Paul Mackerras 20 * <paulus (at) samba.org>". 21 * 22 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 23 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 24 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 25 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 26 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 27 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 28 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 29 */ 30 31 #define RCSID "$Id: ccp.c,v 1.50 2005/06/26 19:34:41 carlsonj Exp $" 32 33 #include <stdlib.h> 34 #include <string.h> 35 36 #include "pppd.h" 37 #include "fsm.h" 38 #include "ccp.h" 39 #include <net/ppp-comp.h> 40 41 #ifdef MPPE 42 #include "chap_ms.h" /* mppe_xxxx_key, mppe_keys_set */ 43 #include "lcp.h" /* lcp_close(), lcp_fsm */ 44 #endif 45 46 static const char rcsid[] = RCSID; 47 48 /* 49 * Unfortunately there is a bug in zlib which means that using a 50 * size of 8 (window size = 256) for Deflate compression will cause 51 * buffer overruns and kernel crashes in the deflate module. 52 * Until this is fixed we only accept sizes in the range 9 .. 15. 53 * Thanks to James Carlson for pointing this out. 54 */ 55 #define DEFLATE_MIN_WORKS 9 56 57 /* 58 * Command-line options. 59 */ 60 static int setbsdcomp __P((char **)); 61 static int setdeflate __P((char **)); 62 static char bsd_value[8]; 63 static char deflate_value[8]; 64 65 /* 66 * Option variables. 67 */ 68 #ifdef MPPE 69 bool refuse_mppe_stateful = 1; /* Allow stateful mode? */ 70 #endif 71 72 static option_t ccp_option_list[] = { 73 { "noccp", o_bool, &ccp_protent.enabled_flag, 74 "Disable CCP negotiation" }, 75 { "-ccp", o_bool, &ccp_protent.enabled_flag, 76 "Disable CCP negotiation", OPT_ALIAS }, 77 78 { "bsdcomp", o_special, (void *)setbsdcomp, 79 "Request BSD-Compress packet compression", 80 OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, bsd_value }, 81 { "nobsdcomp", o_bool, &ccp_wantoptions[0].bsd_compress, 82 "don't allow BSD-Compress", OPT_PRIOSUB | OPT_A2CLR, 83 &ccp_allowoptions[0].bsd_compress }, 84 { "-bsdcomp", o_bool, &ccp_wantoptions[0].bsd_compress, 85 "don't allow BSD-Compress", OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLR, 86 &ccp_allowoptions[0].bsd_compress }, 87 88 { "deflate", o_special, (void *)setdeflate, 89 "request Deflate compression", 90 OPT_PRIO | OPT_A2STRVAL | OPT_STATIC, deflate_value }, 91 { "nodeflate", o_bool, &ccp_wantoptions[0].deflate, 92 "don't allow Deflate compression", OPT_PRIOSUB | OPT_A2CLR, 93 &ccp_allowoptions[0].deflate }, 94 { "-deflate", o_bool, &ccp_wantoptions[0].deflate, 95 "don't allow Deflate compression", OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLR, 96 &ccp_allowoptions[0].deflate }, 97 98 { "nodeflatedraft", o_bool, &ccp_wantoptions[0].deflate_draft, 99 "don't use draft deflate #", OPT_A2COPY, 100 &ccp_allowoptions[0].deflate_draft }, 101 102 { "predictor1", o_bool, &ccp_wantoptions[0].predictor_1, 103 "request Predictor-1", OPT_PRIO | 1 }, 104 { "nopredictor1", o_bool, &ccp_wantoptions[0].predictor_1, 105 "don't allow Predictor-1", OPT_PRIOSUB | OPT_A2CLR, 106 &ccp_allowoptions[0].predictor_1 }, 107 { "-predictor1", o_bool, &ccp_wantoptions[0].predictor_1, 108 "don't allow Predictor-1", OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLR, 109 &ccp_allowoptions[0].predictor_1 }, 110 111 #ifdef MPPE 112 /* MPPE options are symmetrical ... we only set wantoptions here */ 113 { "require-mppe", o_bool, &ccp_wantoptions[0].mppe, 114 "require MPPE encryption", 115 OPT_PRIO | MPPE_OPT_40 | MPPE_OPT_128 }, 116 { "+mppe", o_bool, &ccp_wantoptions[0].mppe, 117 "require MPPE encryption", 118 OPT_ALIAS | OPT_PRIO | MPPE_OPT_40 | MPPE_OPT_128 }, 119 { "nomppe", o_bool, &ccp_wantoptions[0].mppe, 120 "don't allow MPPE encryption", OPT_PRIO }, 121 { "-mppe", o_bool, &ccp_wantoptions[0].mppe, 122 "don't allow MPPE encryption", OPT_ALIAS | OPT_PRIO }, 123 124 /* We use ccp_allowoptions[0].mppe as a junk var ... it is reset later */ 125 { "require-mppe-40", o_bool, &ccp_allowoptions[0].mppe, 126 "require MPPE 40-bit encryption", OPT_PRIO | OPT_A2OR | MPPE_OPT_40, 127 &ccp_wantoptions[0].mppe }, 128 { "+mppe-40", o_bool, &ccp_allowoptions[0].mppe, 129 "require MPPE 40-bit encryption", OPT_PRIO | OPT_A2OR | MPPE_OPT_40, 130 &ccp_wantoptions[0].mppe }, 131 { "nomppe-40", o_bool, &ccp_allowoptions[0].mppe, 132 "don't allow MPPE 40-bit encryption", 133 OPT_PRIOSUB | OPT_A2CLRB | MPPE_OPT_40, &ccp_wantoptions[0].mppe }, 134 { "-mppe-40", o_bool, &ccp_allowoptions[0].mppe, 135 "don't allow MPPE 40-bit encryption", 136 OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLRB | MPPE_OPT_40, 137 &ccp_wantoptions[0].mppe }, 138 139 { "require-mppe-128", o_bool, &ccp_allowoptions[0].mppe, 140 "require MPPE 128-bit encryption", OPT_PRIO | OPT_A2OR | MPPE_OPT_128, 141 &ccp_wantoptions[0].mppe }, 142 { "+mppe-128", o_bool, &ccp_allowoptions[0].mppe, 143 "require MPPE 128-bit encryption", 144 OPT_ALIAS | OPT_PRIO | OPT_A2OR | MPPE_OPT_128, 145 &ccp_wantoptions[0].mppe }, 146 { "nomppe-128", o_bool, &ccp_allowoptions[0].mppe, 147 "don't allow MPPE 128-bit encryption", 148 OPT_PRIOSUB | OPT_A2CLRB | MPPE_OPT_128, &ccp_wantoptions[0].mppe }, 149 { "-mppe-128", o_bool, &ccp_allowoptions[0].mppe, 150 "don't allow MPPE 128-bit encryption", 151 OPT_ALIAS | OPT_PRIOSUB | OPT_A2CLRB | MPPE_OPT_128, 152 &ccp_wantoptions[0].mppe }, 153 154 /* strange one; we always request stateless, but will we allow stateful? */ 155 { "mppe-stateful", o_bool, &refuse_mppe_stateful, 156 "allow MPPE stateful mode", OPT_PRIO }, 157 { "nomppe-stateful", o_bool, &refuse_mppe_stateful, 158 "disallow MPPE stateful mode", OPT_PRIO | 1 }, 159 #endif /* MPPE */ 160 161 { NULL } 162 }; 163 164 /* 165 * Protocol entry points from main code. 166 */ 167 static void ccp_init __P((int unit)); 168 static void ccp_open __P((int unit)); 169 static void ccp_close __P((int unit, char *)); 170 static void ccp_lowerup __P((int unit)); 171 static void ccp_lowerdown __P((int)); 172 static void ccp_input __P((int unit, u_char *pkt, int len)); 173 static void ccp_protrej __P((int unit)); 174 static int ccp_printpkt __P((u_char *pkt, int len, 175 void (*printer) __P((void *, char *, ...)), 176 void *arg)); 177 static void ccp_datainput __P((int unit, u_char *pkt, int len)); 178 179 struct protent ccp_protent = { 180 PPP_CCP, 181 ccp_init, 182 ccp_input, 183 ccp_protrej, 184 ccp_lowerup, 185 ccp_lowerdown, 186 ccp_open, 187 ccp_close, 188 ccp_printpkt, 189 ccp_datainput, 190 1, 191 "CCP", 192 "Compressed", 193 ccp_option_list, 194 NULL, 195 NULL, 196 NULL 197 }; 198 199 fsm ccp_fsm[NUM_PPP]; 200 ccp_options ccp_wantoptions[NUM_PPP]; /* what to request the peer to use */ 201 ccp_options ccp_gotoptions[NUM_PPP]; /* what the peer agreed to do */ 202 ccp_options ccp_allowoptions[NUM_PPP]; /* what we'll agree to do */ 203 ccp_options ccp_hisoptions[NUM_PPP]; /* what we agreed to do */ 204 205 /* 206 * Callbacks for fsm code. 207 */ 208 static void ccp_resetci __P((fsm *)); 209 static int ccp_cilen __P((fsm *)); 210 static void ccp_addci __P((fsm *, u_char *, int *)); 211 static int ccp_ackci __P((fsm *, u_char *, int)); 212 static int ccp_nakci __P((fsm *, u_char *, int, int)); 213 static int ccp_rejci __P((fsm *, u_char *, int)); 214 static int ccp_reqci __P((fsm *, u_char *, int *, int)); 215 static void ccp_up __P((fsm *)); 216 static void ccp_down __P((fsm *)); 217 static int ccp_extcode __P((fsm *, int, int, u_char *, int)); 218 static void ccp_rack_timeout __P((void *)); 219 static char *method_name __P((ccp_options *, ccp_options *)); 220 221 static fsm_callbacks ccp_callbacks = { 222 ccp_resetci, 223 ccp_cilen, 224 ccp_addci, 225 ccp_ackci, 226 ccp_nakci, 227 ccp_rejci, 228 ccp_reqci, 229 ccp_up, 230 ccp_down, 231 NULL, 232 NULL, 233 NULL, 234 NULL, 235 ccp_extcode, 236 "CCP" 237 }; 238 239 /* 240 * Do we want / did we get any compression? 241 */ 242 #define ANY_COMPRESS(opt) ((opt).deflate || (opt).bsd_compress \ 243 || (opt).predictor_1 || (opt).predictor_2 \ 244 || (opt).mppe) 245 246 /* 247 * Local state (mainly for handling reset-reqs and reset-acks). 248 */ 249 static int ccp_localstate[NUM_PPP]; 250 #define RACK_PENDING 1 /* waiting for reset-ack */ 251 #define RREQ_REPEAT 2 /* send another reset-req if no reset-ack */ 252 253 #define RACKTIMEOUT 1 /* second */ 254 255 static int all_rejected[NUM_PPP]; /* we rejected all peer's options */ 256 257 /* 258 * Option parsing. 259 */ 260 static int 261 setbsdcomp(argv) 262 char **argv; 263 { 264 int rbits, abits; 265 char *str, *endp; 266 267 str = *argv; 268 abits = rbits = strtol(str, &endp, 0); 269 if (endp != str && *endp == ',') { 270 str = endp + 1; 271 abits = strtol(str, &endp, 0); 272 } 273 if (*endp != 0 || endp == str) { 274 option_error("invalid parameter '%s' for bsdcomp option", *argv); 275 return 0; 276 } 277 if ((rbits != 0 && (rbits < BSD_MIN_BITS || rbits > BSD_MAX_BITS)) 278 || (abits != 0 && (abits < BSD_MIN_BITS || abits > BSD_MAX_BITS))) { 279 option_error("bsdcomp option values must be 0 or %d .. %d", 280 BSD_MIN_BITS, BSD_MAX_BITS); 281 return 0; 282 } 283 if (rbits > 0) { 284 ccp_wantoptions[0].bsd_compress = 1; 285 ccp_wantoptions[0].bsd_bits = rbits; 286 } else 287 ccp_wantoptions[0].bsd_compress = 0; 288 if (abits > 0) { 289 ccp_allowoptions[0].bsd_compress = 1; 290 ccp_allowoptions[0].bsd_bits = abits; 291 } else 292 ccp_allowoptions[0].bsd_compress = 0; 293 slprintf(bsd_value, sizeof(bsd_value), 294 rbits == abits? "%d": "%d,%d", rbits, abits); 295 296 return 1; 297 } 298 299 static int 300 setdeflate(argv) 301 char **argv; 302 { 303 int rbits, abits; 304 char *str, *endp; 305 306 str = *argv; 307 abits = rbits = strtol(str, &endp, 0); 308 if (endp != str && *endp == ',') { 309 str = endp + 1; 310 abits = strtol(str, &endp, 0); 311 } 312 if (*endp != 0 || endp == str) { 313 option_error("invalid parameter '%s' for deflate option", *argv); 314 return 0; 315 } 316 if ((rbits != 0 && (rbits < DEFLATE_MIN_SIZE || rbits > DEFLATE_MAX_SIZE)) 317 || (abits != 0 && (abits < DEFLATE_MIN_SIZE 318 || abits > DEFLATE_MAX_SIZE))) { 319 option_error("deflate option values must be 0 or %d .. %d", 320 DEFLATE_MIN_SIZE, DEFLATE_MAX_SIZE); 321 return 0; 322 } 323 if (rbits == DEFLATE_MIN_SIZE || abits == DEFLATE_MIN_SIZE) { 324 if (rbits == DEFLATE_MIN_SIZE) 325 rbits = DEFLATE_MIN_WORKS; 326 if (abits == DEFLATE_MIN_SIZE) 327 abits = DEFLATE_MIN_WORKS; 328 warn("deflate option value of %d changed to %d to avoid zlib bug", 329 DEFLATE_MIN_SIZE, DEFLATE_MIN_WORKS); 330 } 331 if (rbits > 0) { 332 ccp_wantoptions[0].deflate = 1; 333 ccp_wantoptions[0].deflate_size = rbits; 334 } else 335 ccp_wantoptions[0].deflate = 0; 336 if (abits > 0) { 337 ccp_allowoptions[0].deflate = 1; 338 ccp_allowoptions[0].deflate_size = abits; 339 } else 340 ccp_allowoptions[0].deflate = 0; 341 slprintf(deflate_value, sizeof(deflate_value), 342 rbits == abits? "%d": "%d,%d", rbits, abits); 343 344 return 1; 345 } 346 347 /* 348 * ccp_init - initialize CCP. 349 */ 350 static void 351 ccp_init(unit) 352 int unit; 353 { 354 fsm *f = &ccp_fsm[unit]; 355 356 f->unit = unit; 357 f->protocol = PPP_CCP; 358 f->callbacks = &ccp_callbacks; 359 fsm_init(f); 360 361 memset(&ccp_wantoptions[unit], 0, sizeof(ccp_options)); 362 memset(&ccp_gotoptions[unit], 0, sizeof(ccp_options)); 363 memset(&ccp_allowoptions[unit], 0, sizeof(ccp_options)); 364 memset(&ccp_hisoptions[unit], 0, sizeof(ccp_options)); 365 366 ccp_wantoptions[0].deflate = 1; 367 ccp_wantoptions[0].deflate_size = DEFLATE_MAX_SIZE; 368 ccp_wantoptions[0].deflate_correct = 1; 369 ccp_wantoptions[0].deflate_draft = 1; 370 ccp_allowoptions[0].deflate = 1; 371 ccp_allowoptions[0].deflate_size = DEFLATE_MAX_SIZE; 372 ccp_allowoptions[0].deflate_correct = 1; 373 ccp_allowoptions[0].deflate_draft = 1; 374 375 ccp_wantoptions[0].bsd_compress = 1; 376 ccp_wantoptions[0].bsd_bits = BSD_MAX_BITS; 377 ccp_allowoptions[0].bsd_compress = 1; 378 ccp_allowoptions[0].bsd_bits = BSD_MAX_BITS; 379 380 ccp_allowoptions[0].predictor_1 = 1; 381 } 382 383 /* 384 * ccp_open - CCP is allowed to come up. 385 */ 386 static void 387 ccp_open(unit) 388 int unit; 389 { 390 fsm *f = &ccp_fsm[unit]; 391 392 if (f->state != OPENED) 393 ccp_flags_set(unit, 1, 0); 394 395 /* 396 * Find out which compressors the kernel supports before 397 * deciding whether to open in silent mode. 398 */ 399 ccp_resetci(f); 400 if (!ANY_COMPRESS(ccp_gotoptions[unit])) 401 f->flags |= OPT_SILENT; 402 403 fsm_open(f); 404 } 405 406 /* 407 * ccp_close - Terminate CCP. 408 */ 409 static void 410 ccp_close(unit, reason) 411 int unit; 412 char *reason; 413 { 414 ccp_flags_set(unit, 0, 0); 415 fsm_close(&ccp_fsm[unit], reason); 416 } 417 418 /* 419 * ccp_lowerup - we may now transmit CCP packets. 420 */ 421 static void 422 ccp_lowerup(unit) 423 int unit; 424 { 425 fsm_lowerup(&ccp_fsm[unit]); 426 } 427 428 /* 429 * ccp_lowerdown - we may not transmit CCP packets. 430 */ 431 static void 432 ccp_lowerdown(unit) 433 int unit; 434 { 435 fsm_lowerdown(&ccp_fsm[unit]); 436 } 437 438 /* 439 * ccp_input - process a received CCP packet. 440 */ 441 static void 442 ccp_input(unit, p, len) 443 int unit; 444 u_char *p; 445 int len; 446 { 447 fsm *f = &ccp_fsm[unit]; 448 int oldstate; 449 450 /* 451 * Check for a terminate-request so we can print a message. 452 */ 453 oldstate = f->state; 454 fsm_input(f, p, len); 455 if (oldstate == OPENED && p[0] == TERMREQ && f->state != OPENED) { 456 notice("Compression disabled by peer."); 457 #ifdef MPPE 458 if (ccp_gotoptions[unit].mppe) { 459 error("MPPE disabled, closing LCP"); 460 lcp_close(unit, "MPPE disabled by peer"); 461 } 462 #endif 463 } 464 465 /* 466 * If we get a terminate-ack and we're not asking for compression, 467 * close CCP. 468 */ 469 if (oldstate == REQSENT && p[0] == TERMACK 470 && !ANY_COMPRESS(ccp_gotoptions[unit])) 471 ccp_close(unit, "No compression negotiated"); 472 } 473 474 /* 475 * Handle a CCP-specific code. 476 */ 477 static int 478 ccp_extcode(f, code, id, p, len) 479 fsm *f; 480 int code, id; 481 u_char *p; 482 int len; 483 { 484 switch (code) { 485 case CCP_RESETREQ: 486 if (f->state != OPENED) 487 break; 488 /* send a reset-ack, which the transmitter will see and 489 reset its compression state. */ 490 fsm_sdata(f, CCP_RESETACK, id, NULL, 0); 491 break; 492 493 case CCP_RESETACK: 494 if (ccp_localstate[f->unit] & RACK_PENDING && id == f->reqid) { 495 ccp_localstate[f->unit] &= ~(RACK_PENDING | RREQ_REPEAT); 496 UNTIMEOUT(ccp_rack_timeout, f); 497 } 498 break; 499 500 default: 501 return 0; 502 } 503 504 return 1; 505 } 506 507 /* 508 * ccp_protrej - peer doesn't talk CCP. 509 */ 510 static void 511 ccp_protrej(unit) 512 int unit; 513 { 514 ccp_flags_set(unit, 0, 0); 515 fsm_lowerdown(&ccp_fsm[unit]); 516 517 #ifdef MPPE 518 if (ccp_gotoptions[unit].mppe) { 519 error("MPPE required but peer negotiation failed"); 520 lcp_close(unit, "MPPE required but peer negotiation failed"); 521 } 522 #endif 523 524 } 525 526 /* 527 * ccp_resetci - initialize at start of negotiation. 528 */ 529 static void 530 ccp_resetci(f) 531 fsm *f; 532 { 533 ccp_options *go = &ccp_gotoptions[f->unit]; 534 u_char opt_buf[CCP_MAX_OPTION_LENGTH]; 535 536 *go = ccp_wantoptions[f->unit]; 537 all_rejected[f->unit] = 0; 538 539 #ifdef MPPE 540 if (go->mppe) { 541 ccp_options *ao = &ccp_allowoptions[f->unit]; 542 int auth_mschap_bits = auth_done[f->unit]; 543 int numbits; 544 545 /* 546 * Start with a basic sanity check: mschap[v2] auth must be in 547 * exactly one direction. RFC 3079 says that the keys are 548 * 'derived from the credentials of the peer that initiated the call', 549 * however the PPP protocol doesn't have such a concept, and pppd 550 * cannot get this info externally. Instead we do the best we can. 551 * NB: If MPPE is required, all other compression opts are invalid. 552 * So, we return right away if we can't do it. 553 */ 554 555 /* Leave only the mschap auth bits set */ 556 auth_mschap_bits &= (CHAP_MS_WITHPEER | CHAP_MS_PEER | 557 CHAP_MS2_WITHPEER | CHAP_MS2_PEER); 558 /* Count the mschap auths */ 559 auth_mschap_bits >>= CHAP_MS_SHIFT; 560 numbits = 0; 561 do { 562 numbits += auth_mschap_bits & 1; 563 auth_mschap_bits >>= 1; 564 } while (auth_mschap_bits); 565 if (numbits > 1) { 566 error("MPPE required, but auth done in both directions."); 567 lcp_close(f->unit, "MPPE required but not available"); 568 return; 569 } 570 if (!numbits) { 571 error("MPPE required, but MS-CHAP[v2] auth not performed."); 572 lcp_close(f->unit, "MPPE required but not available"); 573 return; 574 } 575 576 /* A plugin (eg radius) may not have obtained key material. */ 577 if (!mppe_keys_set) { 578 error("MPPE required, but keys are not available. " 579 "Possible plugin problem?"); 580 lcp_close(f->unit, "MPPE required but not available"); 581 return; 582 } 583 584 /* LM auth not supported for MPPE */ 585 if (auth_done[f->unit] & (CHAP_MS_WITHPEER | CHAP_MS_PEER)) { 586 /* This might be noise */ 587 if (go->mppe & MPPE_OPT_40) { 588 notice("Disabling 40-bit MPPE; MS-CHAP LM not supported"); 589 go->mppe &= ~MPPE_OPT_40; 590 ccp_wantoptions[f->unit].mppe &= ~MPPE_OPT_40; 591 } 592 } 593 594 /* Last check: can we actually negotiate something? */ 595 if (!(go->mppe & (MPPE_OPT_40 | MPPE_OPT_128))) { 596 /* Could be misconfig, could be 40-bit disabled above. */ 597 error("MPPE required, but both 40-bit and 128-bit disabled."); 598 lcp_close(f->unit, "MPPE required but not available"); 599 return; 600 } 601 602 /* sync options */ 603 ao->mppe = go->mppe; 604 /* MPPE is not compatible with other compression types */ 605 ao->bsd_compress = go->bsd_compress = 0; 606 ao->predictor_1 = go->predictor_1 = 0; 607 ao->predictor_2 = go->predictor_2 = 0; 608 ao->deflate = go->deflate = 0; 609 } 610 #endif /* MPPE */ 611 612 /* 613 * Check whether the kernel knows about the various 614 * compression methods we might request. 615 */ 616 #ifdef MPPE 617 if (go->mppe) { 618 opt_buf[0] = CI_MPPE; 619 opt_buf[1] = CILEN_MPPE; 620 MPPE_OPTS_TO_CI(go->mppe, &opt_buf[2]); 621 /* Key material unimportant here. */ 622 if (ccp_test(f->unit, opt_buf, CILEN_MPPE + MPPE_MAX_KEY_LEN, 0) <= 0) { 623 error("MPPE required, but kernel has no support."); 624 lcp_close(f->unit, "MPPE required but not available"); 625 } 626 } 627 #endif 628 if (go->bsd_compress) { 629 opt_buf[0] = CI_BSD_COMPRESS; 630 opt_buf[1] = CILEN_BSD_COMPRESS; 631 opt_buf[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, BSD_MIN_BITS); 632 if (ccp_test(f->unit, opt_buf, CILEN_BSD_COMPRESS, 0) <= 0) 633 go->bsd_compress = 0; 634 } 635 if (go->deflate) { 636 if (go->deflate_correct) { 637 opt_buf[0] = CI_DEFLATE; 638 opt_buf[1] = CILEN_DEFLATE; 639 opt_buf[2] = DEFLATE_MAKE_OPT(DEFLATE_MIN_WORKS); 640 opt_buf[3] = DEFLATE_CHK_SEQUENCE; 641 if (ccp_test(f->unit, opt_buf, CILEN_DEFLATE, 0) <= 0) 642 go->deflate_correct = 0; 643 } 644 if (go->deflate_draft) { 645 opt_buf[0] = CI_DEFLATE_DRAFT; 646 opt_buf[1] = CILEN_DEFLATE; 647 opt_buf[2] = DEFLATE_MAKE_OPT(DEFLATE_MIN_WORKS); 648 opt_buf[3] = DEFLATE_CHK_SEQUENCE; 649 if (ccp_test(f->unit, opt_buf, CILEN_DEFLATE, 0) <= 0) 650 go->deflate_draft = 0; 651 } 652 if (!go->deflate_correct && !go->deflate_draft) 653 go->deflate = 0; 654 } 655 if (go->predictor_1) { 656 opt_buf[0] = CI_PREDICTOR_1; 657 opt_buf[1] = CILEN_PREDICTOR_1; 658 if (ccp_test(f->unit, opt_buf, CILEN_PREDICTOR_1, 0) <= 0) 659 go->predictor_1 = 0; 660 } 661 if (go->predictor_2) { 662 opt_buf[0] = CI_PREDICTOR_2; 663 opt_buf[1] = CILEN_PREDICTOR_2; 664 if (ccp_test(f->unit, opt_buf, CILEN_PREDICTOR_2, 0) <= 0) 665 go->predictor_2 = 0; 666 } 667 } 668 669 /* 670 * ccp_cilen - Return total length of our configuration info. 671 */ 672 static int 673 ccp_cilen(f) 674 fsm *f; 675 { 676 ccp_options *go = &ccp_gotoptions[f->unit]; 677 678 return (go->bsd_compress? CILEN_BSD_COMPRESS: 0) 679 + (go->deflate? CILEN_DEFLATE: 0) 680 + (go->predictor_1? CILEN_PREDICTOR_1: 0) 681 + (go->predictor_2? CILEN_PREDICTOR_2: 0) 682 + (go->mppe? CILEN_MPPE: 0); 683 } 684 685 /* 686 * ccp_addci - put our requests in a packet. 687 */ 688 static void 689 ccp_addci(f, p, lenp) 690 fsm *f; 691 u_char *p; 692 int *lenp; 693 { 694 int res; 695 ccp_options *go = &ccp_gotoptions[f->unit]; 696 u_char *p0 = p; 697 698 /* 699 * Add the compression types that we can receive, in decreasing 700 * preference order. Get the kernel to allocate the first one 701 * in case it gets Acked. 702 */ 703 #ifdef MPPE 704 if (go->mppe) { 705 u_char opt_buf[CILEN_MPPE + MPPE_MAX_KEY_LEN]; 706 707 p[0] = opt_buf[0] = CI_MPPE; 708 p[1] = opt_buf[1] = CILEN_MPPE; 709 MPPE_OPTS_TO_CI(go->mppe, &p[2]); 710 MPPE_OPTS_TO_CI(go->mppe, &opt_buf[2]); 711 BCOPY(mppe_recv_key, &opt_buf[CILEN_MPPE], MPPE_MAX_KEY_LEN); 712 res = ccp_test(f->unit, opt_buf, CILEN_MPPE + MPPE_MAX_KEY_LEN, 0); 713 if (res > 0) 714 p += CILEN_MPPE; 715 else 716 /* This shouldn't happen, we've already tested it! */ 717 lcp_close(f->unit, "MPPE required but not available in kernel"); 718 } 719 #endif 720 if (go->deflate) { 721 p[0] = go->deflate_correct? CI_DEFLATE: CI_DEFLATE_DRAFT; 722 p[1] = CILEN_DEFLATE; 723 p[2] = DEFLATE_MAKE_OPT(go->deflate_size); 724 p[3] = DEFLATE_CHK_SEQUENCE; 725 if (p != p0) { 726 p += CILEN_DEFLATE; 727 } else { 728 for (;;) { 729 if (go->deflate_size < DEFLATE_MIN_WORKS) { 730 go->deflate = 0; 731 break; 732 } 733 res = ccp_test(f->unit, p, CILEN_DEFLATE, 0); 734 if (res > 0) { 735 p += CILEN_DEFLATE; 736 break; 737 } else if (res < 0) { 738 go->deflate = 0; 739 break; 740 } 741 --go->deflate_size; 742 p[2] = DEFLATE_MAKE_OPT(go->deflate_size); 743 } 744 } 745 if (p != p0 && go->deflate_correct && go->deflate_draft) { 746 p[0] = CI_DEFLATE_DRAFT; 747 p[1] = CILEN_DEFLATE; 748 p[2] = p[2 - CILEN_DEFLATE]; 749 p[3] = DEFLATE_CHK_SEQUENCE; 750 p += CILEN_DEFLATE; 751 } 752 } 753 if (go->bsd_compress) { 754 p[0] = CI_BSD_COMPRESS; 755 p[1] = CILEN_BSD_COMPRESS; 756 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits); 757 if (p != p0) { 758 p += CILEN_BSD_COMPRESS; /* not the first option */ 759 } else { 760 for (;;) { 761 if (go->bsd_bits < BSD_MIN_BITS) { 762 go->bsd_compress = 0; 763 break; 764 } 765 res = ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 0); 766 if (res > 0) { 767 p += CILEN_BSD_COMPRESS; 768 break; 769 } else if (res < 0) { 770 go->bsd_compress = 0; 771 break; 772 } 773 --go->bsd_bits; 774 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits); 775 } 776 } 777 } 778 /* XXX Should Predictor 2 be preferable to Predictor 1? */ 779 if (go->predictor_1) { 780 p[0] = CI_PREDICTOR_1; 781 p[1] = CILEN_PREDICTOR_1; 782 if (p == p0 && ccp_test(f->unit, p, CILEN_PREDICTOR_1, 0) <= 0) { 783 go->predictor_1 = 0; 784 } else { 785 p += CILEN_PREDICTOR_1; 786 } 787 } 788 if (go->predictor_2) { 789 p[0] = CI_PREDICTOR_2; 790 p[1] = CILEN_PREDICTOR_2; 791 if (p == p0 && ccp_test(f->unit, p, CILEN_PREDICTOR_2, 0) <= 0) { 792 go->predictor_2 = 0; 793 } else { 794 p += CILEN_PREDICTOR_2; 795 } 796 } 797 798 go->method = (p > p0)? p0[0]: -1; 799 800 *lenp = p - p0; 801 } 802 803 /* 804 * ccp_ackci - process a received configure-ack, and return 805 * 1 iff the packet was OK. 806 */ 807 static int 808 ccp_ackci(f, p, len) 809 fsm *f; 810 u_char *p; 811 int len; 812 { 813 ccp_options *go = &ccp_gotoptions[f->unit]; 814 u_char *p0 = p; 815 816 #ifdef MPPE 817 if (go->mppe) { 818 u_char opt_buf[CILEN_MPPE]; 819 820 opt_buf[0] = CI_MPPE; 821 opt_buf[1] = CILEN_MPPE; 822 MPPE_OPTS_TO_CI(go->mppe, &opt_buf[2]); 823 if (len < CILEN_MPPE || memcmp(opt_buf, p, CILEN_MPPE)) 824 return 0; 825 p += CILEN_MPPE; 826 len -= CILEN_MPPE; 827 /* XXX Cope with first/fast ack */ 828 if (len == 0) 829 return 1; 830 } 831 #endif 832 if (go->deflate) { 833 if (len < CILEN_DEFLATE 834 || p[0] != (go->deflate_correct? CI_DEFLATE: CI_DEFLATE_DRAFT) 835 || p[1] != CILEN_DEFLATE 836 || p[2] != DEFLATE_MAKE_OPT(go->deflate_size) 837 || p[3] != DEFLATE_CHK_SEQUENCE) 838 return 0; 839 p += CILEN_DEFLATE; 840 len -= CILEN_DEFLATE; 841 /* XXX Cope with first/fast ack */ 842 if (len == 0) 843 return 1; 844 if (go->deflate_correct && go->deflate_draft) { 845 if (len < CILEN_DEFLATE 846 || p[0] != CI_DEFLATE_DRAFT 847 || p[1] != CILEN_DEFLATE 848 || p[2] != DEFLATE_MAKE_OPT(go->deflate_size) 849 || p[3] != DEFLATE_CHK_SEQUENCE) 850 return 0; 851 p += CILEN_DEFLATE; 852 len -= CILEN_DEFLATE; 853 } 854 } 855 if (go->bsd_compress) { 856 if (len < CILEN_BSD_COMPRESS 857 || p[0] != CI_BSD_COMPRESS || p[1] != CILEN_BSD_COMPRESS 858 || p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits)) 859 return 0; 860 p += CILEN_BSD_COMPRESS; 861 len -= CILEN_BSD_COMPRESS; 862 /* XXX Cope with first/fast ack */ 863 if (p == p0 && len == 0) 864 return 1; 865 } 866 if (go->predictor_1) { 867 if (len < CILEN_PREDICTOR_1 868 || p[0] != CI_PREDICTOR_1 || p[1] != CILEN_PREDICTOR_1) 869 return 0; 870 p += CILEN_PREDICTOR_1; 871 len -= CILEN_PREDICTOR_1; 872 /* XXX Cope with first/fast ack */ 873 if (p == p0 && len == 0) 874 return 1; 875 } 876 if (go->predictor_2) { 877 if (len < CILEN_PREDICTOR_2 878 || p[0] != CI_PREDICTOR_2 || p[1] != CILEN_PREDICTOR_2) 879 return 0; 880 p += CILEN_PREDICTOR_2; 881 len -= CILEN_PREDICTOR_2; 882 /* XXX Cope with first/fast ack */ 883 if (p == p0 && len == 0) 884 return 1; 885 } 886 887 if (len != 0) 888 return 0; 889 return 1; 890 } 891 892 /* 893 * ccp_nakci - process received configure-nak. 894 * Returns 1 iff the nak was OK. 895 */ 896 static int 897 ccp_nakci(f, p, len, treat_as_reject) 898 fsm *f; 899 u_char *p; 900 int len; 901 int treat_as_reject; 902 { 903 ccp_options *go = &ccp_gotoptions[f->unit]; 904 ccp_options no; /* options we've seen already */ 905 ccp_options try; /* options to ask for next time */ 906 907 memset(&no, 0, sizeof(no)); 908 try = *go; 909 910 #ifdef MPPE 911 if (go->mppe && len >= CILEN_MPPE 912 && p[0] == CI_MPPE && p[1] == CILEN_MPPE) { 913 no.mppe = 1; 914 /* 915 * Peer wants us to use a different strength or other setting. 916 * Fail if we aren't willing to use his suggestion. 917 */ 918 MPPE_CI_TO_OPTS(&p[2], try.mppe); 919 if ((try.mppe & MPPE_OPT_STATEFUL) && refuse_mppe_stateful) { 920 error("Refusing MPPE stateful mode offered by peer"); 921 try.mppe = 0; 922 } else if (((go->mppe | MPPE_OPT_STATEFUL) & try.mppe) != try.mppe) { 923 /* Peer must have set options we didn't request (suggest) */ 924 try.mppe = 0; 925 } 926 927 if (!try.mppe) { 928 error("MPPE required but peer negotiation failed"); 929 lcp_close(f->unit, "MPPE required but peer negotiation failed"); 930 } 931 } 932 #endif /* MPPE */ 933 if (go->deflate && len >= CILEN_DEFLATE 934 && p[0] == (go->deflate_correct? CI_DEFLATE: CI_DEFLATE_DRAFT) 935 && p[1] == CILEN_DEFLATE) { 936 no.deflate = 1; 937 /* 938 * Peer wants us to use a different code size or something. 939 * Stop asking for Deflate if we don't understand his suggestion. 940 */ 941 if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL 942 || DEFLATE_SIZE(p[2]) < DEFLATE_MIN_WORKS 943 || p[3] != DEFLATE_CHK_SEQUENCE) 944 try.deflate = 0; 945 else if (DEFLATE_SIZE(p[2]) < go->deflate_size) 946 try.deflate_size = DEFLATE_SIZE(p[2]); 947 p += CILEN_DEFLATE; 948 len -= CILEN_DEFLATE; 949 if (go->deflate_correct && go->deflate_draft 950 && len >= CILEN_DEFLATE && p[0] == CI_DEFLATE_DRAFT 951 && p[1] == CILEN_DEFLATE) { 952 p += CILEN_DEFLATE; 953 len -= CILEN_DEFLATE; 954 } 955 } 956 957 if (go->bsd_compress && len >= CILEN_BSD_COMPRESS 958 && p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) { 959 no.bsd_compress = 1; 960 /* 961 * Peer wants us to use a different number of bits 962 * or a different version. 963 */ 964 if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION) 965 try.bsd_compress = 0; 966 else if (BSD_NBITS(p[2]) < go->bsd_bits) 967 try.bsd_bits = BSD_NBITS(p[2]); 968 p += CILEN_BSD_COMPRESS; 969 len -= CILEN_BSD_COMPRESS; 970 } 971 972 /* 973 * Predictor-1 and 2 have no options, so they can't be Naked. 974 * 975 * There may be remaining options but we ignore them. 976 */ 977 978 if (f->state != OPENED) 979 *go = try; 980 return 1; 981 } 982 983 /* 984 * ccp_rejci - reject some of our suggested compression methods. 985 */ 986 static int 987 ccp_rejci(f, p, len) 988 fsm *f; 989 u_char *p; 990 int len; 991 { 992 ccp_options *go = &ccp_gotoptions[f->unit]; 993 ccp_options try; /* options to request next time */ 994 995 try = *go; 996 997 /* 998 * Cope with empty configure-rejects by ceasing to send 999 * configure-requests. 1000 */ 1001 if (len == 0 && all_rejected[f->unit]) 1002 return -1; 1003 1004 #ifdef MPPE 1005 if (go->mppe && len >= CILEN_MPPE 1006 && p[0] == CI_MPPE && p[1] == CILEN_MPPE) { 1007 error("MPPE required but peer refused"); 1008 lcp_close(f->unit, "MPPE required but peer refused"); 1009 p += CILEN_MPPE; 1010 len -= CILEN_MPPE; 1011 } 1012 #endif 1013 if (go->deflate_correct && len >= CILEN_DEFLATE 1014 && p[0] == CI_DEFLATE && p[1] == CILEN_DEFLATE) { 1015 if (p[2] != DEFLATE_MAKE_OPT(go->deflate_size) 1016 || p[3] != DEFLATE_CHK_SEQUENCE) 1017 return 0; /* Rej is bad */ 1018 try.deflate_correct = 0; 1019 p += CILEN_DEFLATE; 1020 len -= CILEN_DEFLATE; 1021 } 1022 if (go->deflate_draft && len >= CILEN_DEFLATE 1023 && p[0] == CI_DEFLATE_DRAFT && p[1] == CILEN_DEFLATE) { 1024 if (p[2] != DEFLATE_MAKE_OPT(go->deflate_size) 1025 || p[3] != DEFLATE_CHK_SEQUENCE) 1026 return 0; /* Rej is bad */ 1027 try.deflate_draft = 0; 1028 p += CILEN_DEFLATE; 1029 len -= CILEN_DEFLATE; 1030 } 1031 if (!try.deflate_correct && !try.deflate_draft) 1032 try.deflate = 0; 1033 if (go->bsd_compress && len >= CILEN_BSD_COMPRESS 1034 && p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) { 1035 if (p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits)) 1036 return 0; 1037 try.bsd_compress = 0; 1038 p += CILEN_BSD_COMPRESS; 1039 len -= CILEN_BSD_COMPRESS; 1040 } 1041 if (go->predictor_1 && len >= CILEN_PREDICTOR_1 1042 && p[0] == CI_PREDICTOR_1 && p[1] == CILEN_PREDICTOR_1) { 1043 try.predictor_1 = 0; 1044 p += CILEN_PREDICTOR_1; 1045 len -= CILEN_PREDICTOR_1; 1046 } 1047 if (go->predictor_2 && len >= CILEN_PREDICTOR_2 1048 && p[0] == CI_PREDICTOR_2 && p[1] == CILEN_PREDICTOR_2) { 1049 try.predictor_2 = 0; 1050 p += CILEN_PREDICTOR_2; 1051 len -= CILEN_PREDICTOR_2; 1052 } 1053 1054 if (len != 0) 1055 return 0; 1056 1057 if (f->state != OPENED) 1058 *go = try; 1059 1060 return 1; 1061 } 1062 1063 /* 1064 * ccp_reqci - processed a received configure-request. 1065 * Returns CONFACK, CONFNAK or CONFREJ and the packet modified 1066 * appropriately. 1067 */ 1068 static int 1069 ccp_reqci(f, p, lenp, dont_nak) 1070 fsm *f; 1071 u_char *p; 1072 int *lenp; 1073 int dont_nak; 1074 { 1075 int ret, newret, res; 1076 u_char *p0, *retp; 1077 int len, clen, type, nb; 1078 ccp_options *ho = &ccp_hisoptions[f->unit]; 1079 ccp_options *ao = &ccp_allowoptions[f->unit]; 1080 #ifdef MPPE 1081 bool rej_for_ci_mppe = 1; /* Are we rejecting based on a bad/missing */ 1082 /* CI_MPPE, or due to other options? */ 1083 #endif 1084 1085 ret = CONFACK; 1086 retp = p0 = p; 1087 len = *lenp; 1088 1089 memset(ho, 0, sizeof(ccp_options)); 1090 ho->method = (len > 0)? p[0]: -1; 1091 1092 while (len > 0) { 1093 newret = CONFACK; 1094 if (len < 2 || p[1] < 2 || p[1] > len) { 1095 /* length is bad */ 1096 clen = len; 1097 newret = CONFREJ; 1098 1099 } else { 1100 type = p[0]; 1101 clen = p[1]; 1102 1103 switch (type) { 1104 #ifdef MPPE 1105 case CI_MPPE: 1106 if (!ao->mppe || clen != CILEN_MPPE) { 1107 newret = CONFREJ; 1108 break; 1109 } 1110 MPPE_CI_TO_OPTS(&p[2], ho->mppe); 1111 1112 /* Nak if anything unsupported or unknown are set. */ 1113 if (ho->mppe & MPPE_OPT_UNSUPPORTED) { 1114 newret = CONFNAK; 1115 ho->mppe &= ~MPPE_OPT_UNSUPPORTED; 1116 } 1117 if (ho->mppe & MPPE_OPT_UNKNOWN) { 1118 newret = CONFNAK; 1119 ho->mppe &= ~MPPE_OPT_UNKNOWN; 1120 } 1121 1122 /* Check state opt */ 1123 if (ho->mppe & MPPE_OPT_STATEFUL) { 1124 /* 1125 * We can Nak and request stateless, but it's a 1126 * lot easier to just assume the peer will request 1127 * it if he can do it; stateful mode is bad over 1128 * the Internet -- which is where we expect MPPE. 1129 */ 1130 if (refuse_mppe_stateful) { 1131 error("Refusing MPPE stateful mode offered by peer"); 1132 newret = CONFREJ; 1133 break; 1134 } 1135 } 1136 1137 /* Find out which of {S,L} are set. */ 1138 if ((ho->mppe & MPPE_OPT_128) 1139 && (ho->mppe & MPPE_OPT_40)) { 1140 /* Both are set, negotiate the strongest. */ 1141 newret = CONFNAK; 1142 if (ao->mppe & MPPE_OPT_128) 1143 ho->mppe &= ~MPPE_OPT_40; 1144 else if (ao->mppe & MPPE_OPT_40) 1145 ho->mppe &= ~MPPE_OPT_128; 1146 else { 1147 newret = CONFREJ; 1148 break; 1149 } 1150 } else if (ho->mppe & MPPE_OPT_128) { 1151 if (!(ao->mppe & MPPE_OPT_128)) { 1152 newret = CONFREJ; 1153 break; 1154 } 1155 } else if (ho->mppe & MPPE_OPT_40) { 1156 if (!(ao->mppe & MPPE_OPT_40)) { 1157 newret = CONFREJ; 1158 break; 1159 } 1160 } else { 1161 /* Neither are set. */ 1162 /* We cannot accept this. */ 1163 newret = CONFNAK; 1164 /* Give the peer our idea of what can be used, 1165 so it can choose and confirm */ 1166 ho->mppe = ao->mppe; 1167 } 1168 1169 /* rebuild the opts */ 1170 MPPE_OPTS_TO_CI(ho->mppe, &p[2]); 1171 if (newret == CONFACK) { 1172 u_char opt_buf[CILEN_MPPE + MPPE_MAX_KEY_LEN]; 1173 int mtu; 1174 1175 BCOPY(p, opt_buf, CILEN_MPPE); 1176 BCOPY(mppe_send_key, &opt_buf[CILEN_MPPE], 1177 MPPE_MAX_KEY_LEN); 1178 if (ccp_test(f->unit, opt_buf, 1179 CILEN_MPPE + MPPE_MAX_KEY_LEN, 1) <= 0) { 1180 /* This shouldn't happen, we've already tested it! */ 1181 error("MPPE required, but kernel has no support."); 1182 lcp_close(f->unit, "MPPE required but not available"); 1183 newret = CONFREJ; 1184 break; 1185 } 1186 /* 1187 * We need to decrease the interface MTU by MPPE_PAD 1188 * because MPPE frames **grow**. The kernel [must] 1189 * allocate MPPE_PAD extra bytes in xmit buffers. 1190 */ 1191 mtu = netif_get_mtu(f->unit); 1192 if (mtu) 1193 netif_set_mtu(f->unit, mtu - MPPE_PAD); 1194 else 1195 newret = CONFREJ; 1196 } 1197 1198 /* 1199 * We have accepted MPPE or are willing to negotiate 1200 * MPPE parameters. A CONFREJ is due to subsequent 1201 * (non-MPPE) processing. 1202 */ 1203 rej_for_ci_mppe = 0; 1204 break; 1205 #endif /* MPPE */ 1206 case CI_DEFLATE: 1207 case CI_DEFLATE_DRAFT: 1208 if (!ao->deflate || clen != CILEN_DEFLATE 1209 || (!ao->deflate_correct && type == CI_DEFLATE) 1210 || (!ao->deflate_draft && type == CI_DEFLATE_DRAFT)) { 1211 newret = CONFREJ; 1212 break; 1213 } 1214 1215 ho->deflate = 1; 1216 ho->deflate_size = nb = DEFLATE_SIZE(p[2]); 1217 if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL 1218 || p[3] != DEFLATE_CHK_SEQUENCE 1219 || nb > ao->deflate_size || nb < DEFLATE_MIN_WORKS) { 1220 newret = CONFNAK; 1221 if (!dont_nak) { 1222 p[2] = DEFLATE_MAKE_OPT(ao->deflate_size); 1223 p[3] = DEFLATE_CHK_SEQUENCE; 1224 /* fall through to test this #bits below */ 1225 } else 1226 break; 1227 } 1228 1229 /* 1230 * Check whether we can do Deflate with the window 1231 * size they want. If the window is too big, reduce 1232 * it until the kernel can cope and nak with that. 1233 * We only check this for the first option. 1234 */ 1235 if (p == p0) { 1236 for (;;) { 1237 res = ccp_test(f->unit, p, CILEN_DEFLATE, 1); 1238 if (res > 0) 1239 break; /* it's OK now */ 1240 if (res < 0 || nb == DEFLATE_MIN_WORKS || dont_nak) { 1241 newret = CONFREJ; 1242 p[2] = DEFLATE_MAKE_OPT(ho->deflate_size); 1243 break; 1244 } 1245 newret = CONFNAK; 1246 --nb; 1247 p[2] = DEFLATE_MAKE_OPT(nb); 1248 } 1249 } 1250 break; 1251 1252 case CI_BSD_COMPRESS: 1253 if (!ao->bsd_compress || clen != CILEN_BSD_COMPRESS) { 1254 newret = CONFREJ; 1255 break; 1256 } 1257 1258 ho->bsd_compress = 1; 1259 ho->bsd_bits = nb = BSD_NBITS(p[2]); 1260 if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION 1261 || nb > ao->bsd_bits || nb < BSD_MIN_BITS) { 1262 newret = CONFNAK; 1263 if (!dont_nak) { 1264 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, ao->bsd_bits); 1265 /* fall through to test this #bits below */ 1266 } else 1267 break; 1268 } 1269 1270 /* 1271 * Check whether we can do BSD-Compress with the code 1272 * size they want. If the code size is too big, reduce 1273 * it until the kernel can cope and nak with that. 1274 * We only check this for the first option. 1275 */ 1276 if (p == p0) { 1277 for (;;) { 1278 res = ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 1); 1279 if (res > 0) 1280 break; 1281 if (res < 0 || nb == BSD_MIN_BITS || dont_nak) { 1282 newret = CONFREJ; 1283 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, 1284 ho->bsd_bits); 1285 break; 1286 } 1287 newret = CONFNAK; 1288 --nb; 1289 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, nb); 1290 } 1291 } 1292 break; 1293 1294 case CI_PREDICTOR_1: 1295 if (!ao->predictor_1 || clen != CILEN_PREDICTOR_1) { 1296 newret = CONFREJ; 1297 break; 1298 } 1299 1300 ho->predictor_1 = 1; 1301 if (p == p0 1302 && ccp_test(f->unit, p, CILEN_PREDICTOR_1, 1) <= 0) { 1303 newret = CONFREJ; 1304 } 1305 break; 1306 1307 case CI_PREDICTOR_2: 1308 if (!ao->predictor_2 || clen != CILEN_PREDICTOR_2) { 1309 newret = CONFREJ; 1310 break; 1311 } 1312 1313 ho->predictor_2 = 1; 1314 if (p == p0 1315 && ccp_test(f->unit, p, CILEN_PREDICTOR_2, 1) <= 0) { 1316 newret = CONFREJ; 1317 } 1318 break; 1319 1320 default: 1321 newret = CONFREJ; 1322 } 1323 } 1324 1325 if (newret == CONFNAK && dont_nak) 1326 newret = CONFREJ; 1327 if (!(newret == CONFACK || (newret == CONFNAK && ret == CONFREJ))) { 1328 /* we're returning this option */ 1329 if (newret == CONFREJ && ret == CONFNAK) 1330 retp = p0; 1331 ret = newret; 1332 if (p != retp) 1333 BCOPY(p, retp, clen); 1334 retp += clen; 1335 } 1336 1337 p += clen; 1338 len -= clen; 1339 } 1340 1341 if (ret != CONFACK) { 1342 if (ret == CONFREJ && *lenp == retp - p0) 1343 all_rejected[f->unit] = 1; 1344 else 1345 *lenp = retp - p0; 1346 } 1347 #ifdef MPPE 1348 if (ret == CONFREJ && ao->mppe && rej_for_ci_mppe) { 1349 error("MPPE required but peer negotiation failed"); 1350 lcp_close(f->unit, "MPPE required but peer negotiation failed"); 1351 } 1352 #endif 1353 return ret; 1354 } 1355 1356 /* 1357 * Make a string name for a compression method (or 2). 1358 */ 1359 static char * 1360 method_name(opt, opt2) 1361 ccp_options *opt, *opt2; 1362 { 1363 static char result[64]; 1364 1365 if (!ANY_COMPRESS(*opt)) 1366 return "(none)"; 1367 switch (opt->method) { 1368 #ifdef MPPE 1369 case CI_MPPE: 1370 { 1371 char *p = result; 1372 char *q = result + sizeof(result); /* 1 past result */ 1373 1374 slprintf(p, q - p, "MPPE "); 1375 p += 5; 1376 if (opt->mppe & MPPE_OPT_128) { 1377 slprintf(p, q - p, "128-bit "); 1378 p += 8; 1379 } 1380 if (opt->mppe & MPPE_OPT_40) { 1381 slprintf(p, q - p, "40-bit "); 1382 p += 7; 1383 } 1384 if (opt->mppe & MPPE_OPT_STATEFUL) 1385 slprintf(p, q - p, "stateful"); 1386 else 1387 slprintf(p, q - p, "stateless"); 1388 1389 break; 1390 } 1391 #endif 1392 case CI_DEFLATE: 1393 case CI_DEFLATE_DRAFT: 1394 if (opt2 != NULL && opt2->deflate_size != opt->deflate_size) 1395 slprintf(result, sizeof(result), "Deflate%s (%d/%d)", 1396 (opt->method == CI_DEFLATE_DRAFT? "(old#)": ""), 1397 opt->deflate_size, opt2->deflate_size); 1398 else 1399 slprintf(result, sizeof(result), "Deflate%s (%d)", 1400 (opt->method == CI_DEFLATE_DRAFT? "(old#)": ""), 1401 opt->deflate_size); 1402 break; 1403 case CI_BSD_COMPRESS: 1404 if (opt2 != NULL && opt2->bsd_bits != opt->bsd_bits) 1405 slprintf(result, sizeof(result), "BSD-Compress (%d/%d)", 1406 opt->bsd_bits, opt2->bsd_bits); 1407 else 1408 slprintf(result, sizeof(result), "BSD-Compress (%d)", 1409 opt->bsd_bits); 1410 break; 1411 case CI_PREDICTOR_1: 1412 return "Predictor 1"; 1413 case CI_PREDICTOR_2: 1414 return "Predictor 2"; 1415 default: 1416 slprintf(result, sizeof(result), "Method %d", opt->method); 1417 } 1418 return result; 1419 } 1420 1421 /* 1422 * CCP has come up - inform the kernel driver and log a message. 1423 */ 1424 static void 1425 ccp_up(f) 1426 fsm *f; 1427 { 1428 ccp_options *go = &ccp_gotoptions[f->unit]; 1429 ccp_options *ho = &ccp_hisoptions[f->unit]; 1430 char method1[64]; 1431 1432 ccp_flags_set(f->unit, 1, 1); 1433 if (ANY_COMPRESS(*go)) { 1434 if (ANY_COMPRESS(*ho)) { 1435 if (go->method == ho->method) { 1436 notice("%s compression enabled", method_name(go, ho)); 1437 } else { 1438 strlcpy(method1, method_name(go, NULL), sizeof(method1)); 1439 notice("%s / %s compression enabled", 1440 method1, method_name(ho, NULL)); 1441 } 1442 } else 1443 notice("%s receive compression enabled", method_name(go, NULL)); 1444 } else if (ANY_COMPRESS(*ho)) 1445 notice("%s transmit compression enabled", method_name(ho, NULL)); 1446 #ifdef MPPE 1447 if (go->mppe) { 1448 BZERO(mppe_recv_key, MPPE_MAX_KEY_LEN); 1449 BZERO(mppe_send_key, MPPE_MAX_KEY_LEN); 1450 continue_networks(f->unit); /* Bring up IP et al */ 1451 } 1452 #endif 1453 } 1454 1455 /* 1456 * CCP has gone down - inform the kernel driver. 1457 */ 1458 static void 1459 ccp_down(f) 1460 fsm *f; 1461 { 1462 if (ccp_localstate[f->unit] & RACK_PENDING) 1463 UNTIMEOUT(ccp_rack_timeout, f); 1464 ccp_localstate[f->unit] = 0; 1465 ccp_flags_set(f->unit, 1, 0); 1466 #ifdef MPPE 1467 if (ccp_gotoptions[f->unit].mppe) { 1468 ccp_gotoptions[f->unit].mppe = 0; 1469 if (lcp_fsm[f->unit].state == OPENED) { 1470 /* If LCP is not already going down, make sure it does. */ 1471 error("MPPE disabled"); 1472 lcp_close(f->unit, "MPPE disabled"); 1473 } 1474 } 1475 #endif 1476 } 1477 1478 /* 1479 * Print the contents of a CCP packet. 1480 */ 1481 static char *ccp_codenames[] = { 1482 "ConfReq", "ConfAck", "ConfNak", "ConfRej", 1483 "TermReq", "TermAck", "CodeRej", 1484 NULL, NULL, NULL, NULL, NULL, NULL, 1485 "ResetReq", "ResetAck", 1486 }; 1487 1488 static int 1489 ccp_printpkt(p, plen, printer, arg) 1490 u_char *p; 1491 int plen; 1492 void (*printer) __P((void *, char *, ...)); 1493 void *arg; 1494 { 1495 u_char *p0, *optend; 1496 int code, id, len; 1497 int optlen; 1498 1499 p0 = p; 1500 if (plen < HEADERLEN) 1501 return 0; 1502 code = p[0]; 1503 id = p[1]; 1504 len = (p[2] << 8) + p[3]; 1505 if (len < HEADERLEN || len > plen) 1506 return 0; 1507 1508 if (code >= 1 && code <= sizeof(ccp_codenames) / sizeof(char *) 1509 && ccp_codenames[code-1] != NULL) 1510 printer(arg, " %s", ccp_codenames[code-1]); 1511 else 1512 printer(arg, " code=0x%x", code); 1513 printer(arg, " id=0x%x", id); 1514 len -= HEADERLEN; 1515 p += HEADERLEN; 1516 1517 switch (code) { 1518 case CONFREQ: 1519 case CONFACK: 1520 case CONFNAK: 1521 case CONFREJ: 1522 /* print list of possible compression methods */ 1523 while (len >= 2) { 1524 code = p[0]; 1525 optlen = p[1]; 1526 if (optlen < 2 || optlen > len) 1527 break; 1528 printer(arg, " <"); 1529 len -= optlen; 1530 optend = p + optlen; 1531 switch (code) { 1532 #ifdef MPPE 1533 case CI_MPPE: 1534 if (optlen >= CILEN_MPPE) { 1535 u_char mppe_opts; 1536 1537 MPPE_CI_TO_OPTS(&p[2], mppe_opts); 1538 printer(arg, "mppe %s %s %s %s %s %s%s", 1539 (p[2] & MPPE_H_BIT)? "+H": "-H", 1540 (p[5] & MPPE_M_BIT)? "+M": "-M", 1541 (p[5] & MPPE_S_BIT)? "+S": "-S", 1542 (p[5] & MPPE_L_BIT)? "+L": "-L", 1543 (p[5] & MPPE_D_BIT)? "+D": "-D", 1544 (p[5] & MPPE_C_BIT)? "+C": "-C", 1545 (mppe_opts & MPPE_OPT_UNKNOWN)? " +U": ""); 1546 if (mppe_opts & MPPE_OPT_UNKNOWN) 1547 printer(arg, " (%.2x %.2x %.2x %.2x)", 1548 p[2], p[3], p[4], p[5]); 1549 p += CILEN_MPPE; 1550 } 1551 break; 1552 #endif 1553 case CI_DEFLATE: 1554 case CI_DEFLATE_DRAFT: 1555 if (optlen >= CILEN_DEFLATE) { 1556 printer(arg, "deflate%s %d", 1557 (code == CI_DEFLATE_DRAFT? "(old#)": ""), 1558 DEFLATE_SIZE(p[2])); 1559 if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL) 1560 printer(arg, " method %d", DEFLATE_METHOD(p[2])); 1561 if (p[3] != DEFLATE_CHK_SEQUENCE) 1562 printer(arg, " check %d", p[3]); 1563 p += CILEN_DEFLATE; 1564 } 1565 break; 1566 case CI_BSD_COMPRESS: 1567 if (optlen >= CILEN_BSD_COMPRESS) { 1568 printer(arg, "bsd v%d %d", BSD_VERSION(p[2]), 1569 BSD_NBITS(p[2])); 1570 p += CILEN_BSD_COMPRESS; 1571 } 1572 break; 1573 case CI_PREDICTOR_1: 1574 if (optlen >= CILEN_PREDICTOR_1) { 1575 printer(arg, "predictor 1"); 1576 p += CILEN_PREDICTOR_1; 1577 } 1578 break; 1579 case CI_PREDICTOR_2: 1580 if (optlen >= CILEN_PREDICTOR_2) { 1581 printer(arg, "predictor 2"); 1582 p += CILEN_PREDICTOR_2; 1583 } 1584 break; 1585 } 1586 while (p < optend) 1587 printer(arg, " %.2x", *p++); 1588 printer(arg, ">"); 1589 } 1590 break; 1591 1592 case TERMACK: 1593 case TERMREQ: 1594 if (len > 0 && *p >= ' ' && *p < 0x7f) { 1595 print_string((char *)p, len, printer, arg); 1596 p += len; 1597 len = 0; 1598 } 1599 break; 1600 } 1601 1602 /* dump out the rest of the packet in hex */ 1603 while (--len >= 0) 1604 printer(arg, " %.2x", *p++); 1605 1606 return p - p0; 1607 } 1608 1609 /* 1610 * We have received a packet that the decompressor failed to 1611 * decompress. Here we would expect to issue a reset-request, but 1612 * Motorola has a patent on resetting the compressor as a result of 1613 * detecting an error in the decompressed data after decompression. 1614 * (See US patent 5,130,993; international patent publication number 1615 * WO 91/10289; Australian patent 73296/91.) 1616 * 1617 * So we ask the kernel whether the error was detected after 1618 * decompression; if it was, we take CCP down, thus disabling 1619 * compression :-(, otherwise we issue the reset-request. 1620 */ 1621 static void 1622 ccp_datainput(unit, pkt, len) 1623 int unit; 1624 u_char *pkt; 1625 int len; 1626 { 1627 fsm *f; 1628 1629 f = &ccp_fsm[unit]; 1630 if (f->state == OPENED) { 1631 if (ccp_fatal_error(unit)) { 1632 /* 1633 * Disable compression by taking CCP down. 1634 */ 1635 error("Lost compression sync: disabling compression"); 1636 ccp_close(unit, "Lost compression sync"); 1637 #ifdef MPPE 1638 /* 1639 * If we were doing MPPE, we must also take the link down. 1640 */ 1641 if (ccp_gotoptions[unit].mppe) { 1642 error("Too many MPPE errors, closing LCP"); 1643 lcp_close(unit, "Too many MPPE errors"); 1644 } 1645 #endif 1646 } else { 1647 /* 1648 * Send a reset-request to reset the peer's compressor. 1649 * We don't do that if we are still waiting for an 1650 * acknowledgement to a previous reset-request. 1651 */ 1652 if (!(ccp_localstate[f->unit] & RACK_PENDING)) { 1653 fsm_sdata(f, CCP_RESETREQ, f->reqid = ++f->id, NULL, 0); 1654 TIMEOUT(ccp_rack_timeout, f, RACKTIMEOUT); 1655 ccp_localstate[f->unit] |= RACK_PENDING; 1656 } else 1657 ccp_localstate[f->unit] |= RREQ_REPEAT; 1658 } 1659 } 1660 } 1661 1662 /* 1663 * Timeout waiting for reset-ack. 1664 */ 1665 static void 1666 ccp_rack_timeout(arg) 1667 void *arg; 1668 { 1669 fsm *f = arg; 1670 1671 if (f->state == OPENED && ccp_localstate[f->unit] & RREQ_REPEAT) { 1672 fsm_sdata(f, CCP_RESETREQ, f->reqid, NULL, 0); 1673 TIMEOUT(ccp_rack_timeout, f, RACKTIMEOUT); 1674 ccp_localstate[f->unit] &= ~RREQ_REPEAT; 1675 } else 1676 ccp_localstate[f->unit] &= ~RACK_PENDING; 1677 } 1678 1679
