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 1.48 2004/11/13 02:28:15 paulus 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 { 902 ccp_options *go = &ccp_gotoptions[f->unit]; 903 ccp_options no; /* options we've seen already */ 904 ccp_options try; /* options to ask for next time */ 905 906 memset(&no, 0, sizeof(no)); 907 try = *go; 908 909 #ifdef MPPE 910 if (go->mppe && len >= CILEN_MPPE 911 && p[0] == CI_MPPE && p[1] == CILEN_MPPE) { 912 no.mppe = 1; 913 /* 914 * Peer wants us to use a different strength or other setting. 915 * Fail if we aren't willing to use his suggestion. 916 */ 917 MPPE_CI_TO_OPTS(&p[2], try.mppe); 918 if ((try.mppe & MPPE_OPT_STATEFUL) && refuse_mppe_stateful) { 919 error("Refusing MPPE stateful mode offered by peer"); 920 try.mppe = 0; 921 } else if (((go->mppe | MPPE_OPT_STATEFUL) & try.mppe) != try.mppe) { 922 /* Peer must have set options we didn't request (suggest) */ 923 try.mppe = 0; 924 } 925 926 if (!try.mppe) { 927 error("MPPE required but peer negotiation failed"); 928 lcp_close(f->unit, "MPPE required but peer negotiation failed"); 929 } 930 } 931 #endif /* MPPE */ 932 if (go->deflate && len >= CILEN_DEFLATE 933 && p[0] == (go->deflate_correct? CI_DEFLATE: CI_DEFLATE_DRAFT) 934 && p[1] == CILEN_DEFLATE) { 935 no.deflate = 1; 936 /* 937 * Peer wants us to use a different code size or something. 938 * Stop asking for Deflate if we don't understand his suggestion. 939 */ 940 if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL 941 || DEFLATE_SIZE(p[2]) < DEFLATE_MIN_WORKS 942 || p[3] != DEFLATE_CHK_SEQUENCE) 943 try.deflate = 0; 944 else if (DEFLATE_SIZE(p[2]) < go->deflate_size) 945 try.deflate_size = DEFLATE_SIZE(p[2]); 946 p += CILEN_DEFLATE; 947 len -= CILEN_DEFLATE; 948 if (go->deflate_correct && go->deflate_draft 949 && len >= CILEN_DEFLATE && p[0] == CI_DEFLATE_DRAFT 950 && p[1] == CILEN_DEFLATE) { 951 p += CILEN_DEFLATE; 952 len -= CILEN_DEFLATE; 953 } 954 } 955 956 if (go->bsd_compress && len >= CILEN_BSD_COMPRESS 957 && p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) { 958 no.bsd_compress = 1; 959 /* 960 * Peer wants us to use a different number of bits 961 * or a different version. 962 */ 963 if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION) 964 try.bsd_compress = 0; 965 else if (BSD_NBITS(p[2]) < go->bsd_bits) 966 try.bsd_bits = BSD_NBITS(p[2]); 967 p += CILEN_BSD_COMPRESS; 968 len -= CILEN_BSD_COMPRESS; 969 } 970 971 /* 972 * Predictor-1 and 2 have no options, so they can't be Naked. 973 * 974 * There may be remaining options but we ignore them. 975 */ 976 977 if (f->state != OPENED) 978 *go = try; 979 return 1; 980 } 981 982 /* 983 * ccp_rejci - reject some of our suggested compression methods. 984 */ 985 static int 986 ccp_rejci(f, p, len) 987 fsm *f; 988 u_char *p; 989 int len; 990 { 991 ccp_options *go = &ccp_gotoptions[f->unit]; 992 ccp_options try; /* options to request next time */ 993 994 try = *go; 995 996 /* 997 * Cope with empty configure-rejects by ceasing to send 998 * configure-requests. 999 */ 1000 if (len == 0 && all_rejected[f->unit]) 1001 return -1; 1002 1003 #ifdef MPPE 1004 if (go->mppe && len >= CILEN_MPPE 1005 && p[0] == CI_MPPE && p[1] == CILEN_MPPE) { 1006 error("MPPE required but peer refused"); 1007 lcp_close(f->unit, "MPPE required but peer refused"); 1008 p += CILEN_MPPE; 1009 len -= CILEN_MPPE; 1010 } 1011 #endif 1012 if (go->deflate_correct && len >= CILEN_DEFLATE 1013 && p[0] == CI_DEFLATE && p[1] == CILEN_DEFLATE) { 1014 if (p[2] != DEFLATE_MAKE_OPT(go->deflate_size) 1015 || p[3] != DEFLATE_CHK_SEQUENCE) 1016 return 0; /* Rej is bad */ 1017 try.deflate_correct = 0; 1018 p += CILEN_DEFLATE; 1019 len -= CILEN_DEFLATE; 1020 } 1021 if (go->deflate_draft && len >= CILEN_DEFLATE 1022 && p[0] == CI_DEFLATE_DRAFT && p[1] == CILEN_DEFLATE) { 1023 if (p[2] != DEFLATE_MAKE_OPT(go->deflate_size) 1024 || p[3] != DEFLATE_CHK_SEQUENCE) 1025 return 0; /* Rej is bad */ 1026 try.deflate_draft = 0; 1027 p += CILEN_DEFLATE; 1028 len -= CILEN_DEFLATE; 1029 } 1030 if (!try.deflate_correct && !try.deflate_draft) 1031 try.deflate = 0; 1032 if (go->bsd_compress && len >= CILEN_BSD_COMPRESS 1033 && p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD_COMPRESS) { 1034 if (p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits)) 1035 return 0; 1036 try.bsd_compress = 0; 1037 p += CILEN_BSD_COMPRESS; 1038 len -= CILEN_BSD_COMPRESS; 1039 } 1040 if (go->predictor_1 && len >= CILEN_PREDICTOR_1 1041 && p[0] == CI_PREDICTOR_1 && p[1] == CILEN_PREDICTOR_1) { 1042 try.predictor_1 = 0; 1043 p += CILEN_PREDICTOR_1; 1044 len -= CILEN_PREDICTOR_1; 1045 } 1046 if (go->predictor_2 && len >= CILEN_PREDICTOR_2 1047 && p[0] == CI_PREDICTOR_2 && p[1] == CILEN_PREDICTOR_2) { 1048 try.predictor_2 = 0; 1049 p += CILEN_PREDICTOR_2; 1050 len -= CILEN_PREDICTOR_2; 1051 } 1052 1053 if (len != 0) 1054 return 0; 1055 1056 if (f->state != OPENED) 1057 *go = try; 1058 1059 return 1; 1060 } 1061 1062 /* 1063 * ccp_reqci - processed a received configure-request. 1064 * Returns CONFACK, CONFNAK or CONFREJ and the packet modified 1065 * appropriately. 1066 */ 1067 static int 1068 ccp_reqci(f, p, lenp, dont_nak) 1069 fsm *f; 1070 u_char *p; 1071 int *lenp; 1072 int dont_nak; 1073 { 1074 int ret, newret, res; 1075 u_char *p0, *retp; 1076 int len, clen, type, nb; 1077 ccp_options *ho = &ccp_hisoptions[f->unit]; 1078 ccp_options *ao = &ccp_allowoptions[f->unit]; 1079 #ifdef MPPE 1080 bool rej_for_ci_mppe = 1; /* Are we rejecting based on a bad/missing */ 1081 /* CI_MPPE, or due to other options? */ 1082 #endif 1083 1084 ret = CONFACK; 1085 retp = p0 = p; 1086 len = *lenp; 1087 1088 memset(ho, 0, sizeof(ccp_options)); 1089 ho->method = (len > 0)? p[0]: -1; 1090 1091 while (len > 0) { 1092 newret = CONFACK; 1093 if (len < 2 || p[1] < 2 || p[1] > len) { 1094 /* length is bad */ 1095 clen = len; 1096 newret = CONFREJ; 1097 1098 } else { 1099 type = p[0]; 1100 clen = p[1]; 1101 1102 switch (type) { 1103 #ifdef MPPE 1104 case CI_MPPE: 1105 if (!ao->mppe || clen != CILEN_MPPE) { 1106 newret = CONFREJ; 1107 break; 1108 } 1109 MPPE_CI_TO_OPTS(&p[2], ho->mppe); 1110 1111 /* Nak if anything unsupported or unknown are set. */ 1112 if (ho->mppe & MPPE_OPT_UNSUPPORTED) { 1113 newret = CONFNAK; 1114 ho->mppe &= ~MPPE_OPT_UNSUPPORTED; 1115 } 1116 if (ho->mppe & MPPE_OPT_UNKNOWN) { 1117 newret = CONFNAK; 1118 ho->mppe &= ~MPPE_OPT_UNKNOWN; 1119 } 1120 1121 /* Check state opt */ 1122 if (ho->mppe & MPPE_OPT_STATEFUL) { 1123 /* 1124 * We can Nak and request stateless, but it's a 1125 * lot easier to just assume the peer will request 1126 * it if he can do it; stateful mode is bad over 1127 * the Internet -- which is where we expect MPPE. 1128 */ 1129 if (refuse_mppe_stateful) { 1130 error("Refusing MPPE stateful mode offered by peer"); 1131 newret = CONFREJ; 1132 break; 1133 } 1134 } 1135 1136 /* Find out which of {S,L} are set. */ 1137 if ((ho->mppe & MPPE_OPT_128) 1138 && (ho->mppe & MPPE_OPT_40)) { 1139 /* Both are set, negotiate the strongest. */ 1140 newret = CONFNAK; 1141 if (ao->mppe & MPPE_OPT_128) 1142 ho->mppe &= ~MPPE_OPT_40; 1143 else if (ao->mppe & MPPE_OPT_40) 1144 ho->mppe &= ~MPPE_OPT_128; 1145 else { 1146 newret = CONFREJ; 1147 break; 1148 } 1149 } else if (ho->mppe & MPPE_OPT_128) { 1150 if (!(ao->mppe & MPPE_OPT_128)) { 1151 newret = CONFREJ; 1152 break; 1153 } 1154 } else if (ho->mppe & MPPE_OPT_40) { 1155 if (!(ao->mppe & MPPE_OPT_40)) { 1156 newret = CONFREJ; 1157 break; 1158 } 1159 } else { 1160 /* Neither are set. */ 1161 newret = CONFREJ; 1162 break; 1163 } 1164 1165 /* rebuild the opts */ 1166 MPPE_OPTS_TO_CI(ho->mppe, &p[2]); 1167 if (newret == CONFACK) { 1168 u_char opt_buf[CILEN_MPPE + MPPE_MAX_KEY_LEN]; 1169 int mtu; 1170 1171 BCOPY(p, opt_buf, CILEN_MPPE); 1172 BCOPY(mppe_send_key, &opt_buf[CILEN_MPPE], 1173 MPPE_MAX_KEY_LEN); 1174 if (ccp_test(f->unit, opt_buf, 1175 CILEN_MPPE + MPPE_MAX_KEY_LEN, 1) <= 0) { 1176 /* This shouldn't happen, we've already tested it! */ 1177 error("MPPE required, but kernel has no support."); 1178 lcp_close(f->unit, "MPPE required but not available"); 1179 newret = CONFREJ; 1180 break; 1181 } 1182 /* 1183 * We need to decrease the interface MTU by MPPE_PAD 1184 * because MPPE frames **grow**. The kernel [must] 1185 * allocate MPPE_PAD extra bytes in xmit buffers. 1186 */ 1187 mtu = netif_get_mtu(f->unit); 1188 if (mtu) 1189 netif_set_mtu(f->unit, mtu - MPPE_PAD); 1190 else 1191 newret = CONFREJ; 1192 } 1193 1194 /* 1195 * We have accepted MPPE or are willing to negotiate 1196 * MPPE parameters. A CONFREJ is due to subsequent 1197 * (non-MPPE) processing. 1198 */ 1199 rej_for_ci_mppe = 0; 1200 break; 1201 #endif /* MPPE */ 1202 case CI_DEFLATE: 1203 case CI_DEFLATE_DRAFT: 1204 if (!ao->deflate || clen != CILEN_DEFLATE 1205 || (!ao->deflate_correct && type == CI_DEFLATE) 1206 || (!ao->deflate_draft && type == CI_DEFLATE_DRAFT)) { 1207 newret = CONFREJ; 1208 break; 1209 } 1210 1211 ho->deflate = 1; 1212 ho->deflate_size = nb = DEFLATE_SIZE(p[2]); 1213 if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL 1214 || p[3] != DEFLATE_CHK_SEQUENCE 1215 || nb > ao->deflate_size || nb < DEFLATE_MIN_WORKS) { 1216 newret = CONFNAK; 1217 if (!dont_nak) { 1218 p[2] = DEFLATE_MAKE_OPT(ao->deflate_size); 1219 p[3] = DEFLATE_CHK_SEQUENCE; 1220 /* fall through to test this #bits below */ 1221 } else 1222 break; 1223 } 1224 1225 /* 1226 * Check whether we can do Deflate with the window 1227 * size they want. If the window is too big, reduce 1228 * it until the kernel can cope and nak with that. 1229 * We only check this for the first option. 1230 */ 1231 if (p == p0) { 1232 for (;;) { 1233 res = ccp_test(f->unit, p, CILEN_DEFLATE, 1); 1234 if (res > 0) 1235 break; /* it's OK now */ 1236 if (res < 0 || nb == DEFLATE_MIN_WORKS || dont_nak) { 1237 newret = CONFREJ; 1238 p[2] = DEFLATE_MAKE_OPT(ho->deflate_size); 1239 break; 1240 } 1241 newret = CONFNAK; 1242 --nb; 1243 p[2] = DEFLATE_MAKE_OPT(nb); 1244 } 1245 } 1246 break; 1247 1248 case CI_BSD_COMPRESS: 1249 if (!ao->bsd_compress || clen != CILEN_BSD_COMPRESS) { 1250 newret = CONFREJ; 1251 break; 1252 } 1253 1254 ho->bsd_compress = 1; 1255 ho->bsd_bits = nb = BSD_NBITS(p[2]); 1256 if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION 1257 || nb > ao->bsd_bits || nb < BSD_MIN_BITS) { 1258 newret = CONFNAK; 1259 if (!dont_nak) { 1260 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, ao->bsd_bits); 1261 /* fall through to test this #bits below */ 1262 } else 1263 break; 1264 } 1265 1266 /* 1267 * Check whether we can do BSD-Compress with the code 1268 * size they want. If the code size is too big, reduce 1269 * it until the kernel can cope and nak with that. 1270 * We only check this for the first option. 1271 */ 1272 if (p == p0) { 1273 for (;;) { 1274 res = ccp_test(f->unit, p, CILEN_BSD_COMPRESS, 1); 1275 if (res > 0) 1276 break; 1277 if (res < 0 || nb == BSD_MIN_BITS || dont_nak) { 1278 newret = CONFREJ; 1279 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, 1280 ho->bsd_bits); 1281 break; 1282 } 1283 newret = CONFNAK; 1284 --nb; 1285 p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, nb); 1286 } 1287 } 1288 break; 1289 1290 case CI_PREDICTOR_1: 1291 if (!ao->predictor_1 || clen != CILEN_PREDICTOR_1) { 1292 newret = CONFREJ; 1293 break; 1294 } 1295 1296 ho->predictor_1 = 1; 1297 if (p == p0 1298 && ccp_test(f->unit, p, CILEN_PREDICTOR_1, 1) <= 0) { 1299 newret = CONFREJ; 1300 } 1301 break; 1302 1303 case CI_PREDICTOR_2: 1304 if (!ao->predictor_2 || clen != CILEN_PREDICTOR_2) { 1305 newret = CONFREJ; 1306 break; 1307 } 1308 1309 ho->predictor_2 = 1; 1310 if (p == p0 1311 && ccp_test(f->unit, p, CILEN_PREDICTOR_2, 1) <= 0) { 1312 newret = CONFREJ; 1313 } 1314 break; 1315 1316 default: 1317 newret = CONFREJ; 1318 } 1319 } 1320 1321 if (newret == CONFNAK && dont_nak) 1322 newret = CONFREJ; 1323 if (!(newret == CONFACK || (newret == CONFNAK && ret == CONFREJ))) { 1324 /* we're returning this option */ 1325 if (newret == CONFREJ && ret == CONFNAK) 1326 retp = p0; 1327 ret = newret; 1328 if (p != retp) 1329 BCOPY(p, retp, clen); 1330 retp += clen; 1331 } 1332 1333 p += clen; 1334 len -= clen; 1335 } 1336 1337 if (ret != CONFACK) { 1338 if (ret == CONFREJ && *lenp == retp - p0) 1339 all_rejected[f->unit] = 1; 1340 else 1341 *lenp = retp - p0; 1342 } 1343 #ifdef MPPE 1344 if (ret == CONFREJ && ao->mppe && rej_for_ci_mppe) { 1345 error("MPPE required but peer negotiation failed"); 1346 lcp_close(f->unit, "MPPE required but peer negotiation failed"); 1347 } 1348 #endif 1349 return ret; 1350 } 1351 1352 /* 1353 * Make a string name for a compression method (or 2). 1354 */ 1355 static char * 1356 method_name(opt, opt2) 1357 ccp_options *opt, *opt2; 1358 { 1359 static char result[64]; 1360 1361 if (!ANY_COMPRESS(*opt)) 1362 return "(none)"; 1363 switch (opt->method) { 1364 #ifdef MPPE 1365 case CI_MPPE: 1366 { 1367 char *p = result; 1368 char *q = result + sizeof(result); /* 1 past result */ 1369 1370 slprintf(p, q - p, "MPPE "); 1371 p += 5; 1372 if (opt->mppe & MPPE_OPT_128) { 1373 slprintf(p, q - p, "128-bit "); 1374 p += 8; 1375 } 1376 if (opt->mppe & MPPE_OPT_40) { 1377 slprintf(p, q - p, "40-bit "); 1378 p += 7; 1379 } 1380 if (opt->mppe & MPPE_OPT_STATEFUL) 1381 slprintf(p, q - p, "stateful"); 1382 else 1383 slprintf(p, q - p, "stateless"); 1384 1385 break; 1386 } 1387 #endif 1388 case CI_DEFLATE: 1389 case CI_DEFLATE_DRAFT: 1390 if (opt2 != NULL && opt2->deflate_size != opt->deflate_size) 1391 slprintf(result, sizeof(result), "Deflate%s (%d/%d)", 1392 (opt->method == CI_DEFLATE_DRAFT? "(old#)": ""), 1393 opt->deflate_size, opt2->deflate_size); 1394 else 1395 slprintf(result, sizeof(result), "Deflate%s (%d)", 1396 (opt->method == CI_DEFLATE_DRAFT? "(old#)": ""), 1397 opt->deflate_size); 1398 break; 1399 case CI_BSD_COMPRESS: 1400 if (opt2 != NULL && opt2->bsd_bits != opt->bsd_bits) 1401 slprintf(result, sizeof(result), "BSD-Compress (%d/%d)", 1402 opt->bsd_bits, opt2->bsd_bits); 1403 else 1404 slprintf(result, sizeof(result), "BSD-Compress (%d)", 1405 opt->bsd_bits); 1406 break; 1407 case CI_PREDICTOR_1: 1408 return "Predictor 1"; 1409 case CI_PREDICTOR_2: 1410 return "Predictor 2"; 1411 default: 1412 slprintf(result, sizeof(result), "Method %d", opt->method); 1413 } 1414 return result; 1415 } 1416 1417 /* 1418 * CCP has come up - inform the kernel driver and log a message. 1419 */ 1420 static void 1421 ccp_up(f) 1422 fsm *f; 1423 { 1424 ccp_options *go = &ccp_gotoptions[f->unit]; 1425 ccp_options *ho = &ccp_hisoptions[f->unit]; 1426 char method1[64]; 1427 1428 ccp_flags_set(f->unit, 1, 1); 1429 if (ANY_COMPRESS(*go)) { 1430 if (ANY_COMPRESS(*ho)) { 1431 if (go->method == ho->method) { 1432 notice("%s compression enabled", method_name(go, ho)); 1433 } else { 1434 strlcpy(method1, method_name(go, NULL), sizeof(method1)); 1435 notice("%s / %s compression enabled", 1436 method1, method_name(ho, NULL)); 1437 } 1438 } else 1439 notice("%s receive compression enabled", method_name(go, NULL)); 1440 } else if (ANY_COMPRESS(*ho)) 1441 notice("%s transmit compression enabled", method_name(ho, NULL)); 1442 #ifdef MPPE 1443 if (go->mppe) { 1444 BZERO(mppe_recv_key, MPPE_MAX_KEY_LEN); 1445 BZERO(mppe_send_key, MPPE_MAX_KEY_LEN); 1446 continue_networks(f->unit); /* Bring up IP et al */ 1447 } 1448 #endif 1449 } 1450 1451 /* 1452 * CCP has gone down - inform the kernel driver. 1453 */ 1454 static void 1455 ccp_down(f) 1456 fsm *f; 1457 { 1458 if (ccp_localstate[f->unit] & RACK_PENDING) 1459 UNTIMEOUT(ccp_rack_timeout, f); 1460 ccp_localstate[f->unit] = 0; 1461 ccp_flags_set(f->unit, 1, 0); 1462 #ifdef MPPE 1463 if (ccp_gotoptions[f->unit].mppe) { 1464 ccp_gotoptions[f->unit].mppe = 0; 1465 if (lcp_fsm[f->unit].state == OPENED) { 1466 /* If LCP is not already going down, make sure it does. */ 1467 error("MPPE disabled"); 1468 lcp_close(f->unit, "MPPE disabled"); 1469 } 1470 } 1471 #endif 1472 } 1473 1474 /* 1475 * Print the contents of a CCP packet. 1476 */ 1477 static char *ccp_codenames[] = { 1478 "ConfReq", "ConfAck", "ConfNak", "ConfRej", 1479 "TermReq", "TermAck", "CodeRej", 1480 NULL, NULL, NULL, NULL, NULL, NULL, 1481 "ResetReq", "ResetAck", 1482 }; 1483 1484 static int 1485 ccp_printpkt(p, plen, printer, arg) 1486 u_char *p; 1487 int plen; 1488 void (*printer) __P((void *, char *, ...)); 1489 void *arg; 1490 { 1491 u_char *p0, *optend; 1492 int code, id, len; 1493 int optlen; 1494 1495 p0 = p; 1496 if (plen < HEADERLEN) 1497 return 0; 1498 code = p[0]; 1499 id = p[1]; 1500 len = (p[2] << 8) + p[3]; 1501 if (len < HEADERLEN || len > plen) 1502 return 0; 1503 1504 if (code >= 1 && code <= sizeof(ccp_codenames) / sizeof(char *) 1505 && ccp_codenames[code-1] != NULL) 1506 printer(arg, " %s", ccp_codenames[code-1]); 1507 else 1508 printer(arg, " code=0x%x", code); 1509 printer(arg, " id=0x%x", id); 1510 len -= HEADERLEN; 1511 p += HEADERLEN; 1512 1513 switch (code) { 1514 case CONFREQ: 1515 case CONFACK: 1516 case CONFNAK: 1517 case CONFREJ: 1518 /* print list of possible compression methods */ 1519 while (len >= 2) { 1520 code = p[0]; 1521 optlen = p[1]; 1522 if (optlen < 2 || optlen > len) 1523 break; 1524 printer(arg, " <"); 1525 len -= optlen; 1526 optend = p + optlen; 1527 switch (code) { 1528 #ifdef MPPE 1529 case CI_MPPE: 1530 if (optlen >= CILEN_MPPE) { 1531 u_char mppe_opts; 1532 1533 MPPE_CI_TO_OPTS(&p[2], mppe_opts); 1534 printer(arg, "mppe %s %s %s %s %s %s%s", 1535 (p[2] & MPPE_H_BIT)? "+H": "-H", 1536 (p[5] & MPPE_M_BIT)? "+M": "-M", 1537 (p[5] & MPPE_S_BIT)? "+S": "-S", 1538 (p[5] & MPPE_L_BIT)? "+L": "-L", 1539 (p[5] & MPPE_D_BIT)? "+D": "-D", 1540 (p[5] & MPPE_C_BIT)? "+C": "-C", 1541 (mppe_opts & MPPE_OPT_UNKNOWN)? " +U": ""); 1542 if (mppe_opts & MPPE_OPT_UNKNOWN) 1543 printer(arg, " (%.2x %.2x %.2x %.2x)", 1544 p[2], p[3], p[4], p[5]); 1545 p += CILEN_MPPE; 1546 } 1547 break; 1548 #endif 1549 case CI_DEFLATE: 1550 case CI_DEFLATE_DRAFT: 1551 if (optlen >= CILEN_DEFLATE) { 1552 printer(arg, "deflate%s %d", 1553 (code == CI_DEFLATE_DRAFT? "(old#)": ""), 1554 DEFLATE_SIZE(p[2])); 1555 if (DEFLATE_METHOD(p[2]) != DEFLATE_METHOD_VAL) 1556 printer(arg, " method %d", DEFLATE_METHOD(p[2])); 1557 if (p[3] != DEFLATE_CHK_SEQUENCE) 1558 printer(arg, " check %d", p[3]); 1559 p += CILEN_DEFLATE; 1560 } 1561 break; 1562 case CI_BSD_COMPRESS: 1563 if (optlen >= CILEN_BSD_COMPRESS) { 1564 printer(arg, "bsd v%d %d", BSD_VERSION(p[2]), 1565 BSD_NBITS(p[2])); 1566 p += CILEN_BSD_COMPRESS; 1567 } 1568 break; 1569 case CI_PREDICTOR_1: 1570 if (optlen >= CILEN_PREDICTOR_1) { 1571 printer(arg, "predictor 1"); 1572 p += CILEN_PREDICTOR_1; 1573 } 1574 break; 1575 case CI_PREDICTOR_2: 1576 if (optlen >= CILEN_PREDICTOR_2) { 1577 printer(arg, "predictor 2"); 1578 p += CILEN_PREDICTOR_2; 1579 } 1580 break; 1581 } 1582 while (p < optend) 1583 printer(arg, " %.2x", *p++); 1584 printer(arg, ">"); 1585 } 1586 break; 1587 1588 case TERMACK: 1589 case TERMREQ: 1590 if (len > 0 && *p >= ' ' && *p < 0x7f) { 1591 print_string((char *)p, len, printer, arg); 1592 p += len; 1593 len = 0; 1594 } 1595 break; 1596 } 1597 1598 /* dump out the rest of the packet in hex */ 1599 while (--len >= 0) 1600 printer(arg, " %.2x", *p++); 1601 1602 return p - p0; 1603 } 1604 1605 /* 1606 * We have received a packet that the decompressor failed to 1607 * decompress. Here we would expect to issue a reset-request, but 1608 * Motorola has a patent on resetting the compressor as a result of 1609 * detecting an error in the decompressed data after decompression. 1610 * (See US patent 5,130,993; international patent publication number 1611 * WO 91/10289; Australian patent 73296/91.) 1612 * 1613 * So we ask the kernel whether the error was detected after 1614 * decompression; if it was, we take CCP down, thus disabling 1615 * compression :-(, otherwise we issue the reset-request. 1616 */ 1617 static void 1618 ccp_datainput(unit, pkt, len) 1619 int unit; 1620 u_char *pkt; 1621 int len; 1622 { 1623 fsm *f; 1624 1625 f = &ccp_fsm[unit]; 1626 if (f->state == OPENED) { 1627 if (ccp_fatal_error(unit)) { 1628 /* 1629 * Disable compression by taking CCP down. 1630 */ 1631 error("Lost compression sync: disabling compression"); 1632 ccp_close(unit, "Lost compression sync"); 1633 #ifdef MPPE 1634 /* 1635 * If we were doing MPPE, we must also take the link down. 1636 */ 1637 if (ccp_gotoptions[unit].mppe) { 1638 error("Too many MPPE errors, closing LCP"); 1639 lcp_close(unit, "Too many MPPE errors"); 1640 } 1641 #endif 1642 } else { 1643 /* 1644 * Send a reset-request to reset the peer's compressor. 1645 * We don't do that if we are still waiting for an 1646 * acknowledgement to a previous reset-request. 1647 */ 1648 if (!(ccp_localstate[f->unit] & RACK_PENDING)) { 1649 fsm_sdata(f, CCP_RESETREQ, f->reqid = ++f->id, NULL, 0); 1650 TIMEOUT(ccp_rack_timeout, f, RACKTIMEOUT); 1651 ccp_localstate[f->unit] |= RACK_PENDING; 1652 } else 1653 ccp_localstate[f->unit] |= RREQ_REPEAT; 1654 } 1655 } 1656 } 1657 1658 /* 1659 * Timeout waiting for reset-ack. 1660 */ 1661 static void 1662 ccp_rack_timeout(arg) 1663 void *arg; 1664 { 1665 fsm *f = arg; 1666 1667 if (f->state == OPENED && ccp_localstate[f->unit] & RREQ_REPEAT) { 1668 fsm_sdata(f, CCP_RESETREQ, f->reqid, NULL, 0); 1669 TIMEOUT(ccp_rack_timeout, f, RACKTIMEOUT); 1670 ccp_localstate[f->unit] &= ~RREQ_REPEAT; 1671 } else 1672 ccp_localstate[f->unit] &= ~RACK_PENDING; 1673 } 1674 1675
