1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #include <sys/types.h> 28 #include <sys/systm.h> 29 #include <sys/stream.h> 30 #include <sys/cmn_err.h> 31 #include <sys/ddi.h> 32 #include <sys/strsubr.h> 33 #include <sys/tsol/tnet.h> 34 35 #include <netinet/in.h> 36 #include <netinet/ip6.h> 37 38 #include <inet/common.h> 39 #include <inet/ip.h> 40 #include <inet/ip6.h> 41 #include <inet/mib2.h> 42 #include <inet/sctp_ip.h> 43 #include <inet/ipclassifier.h> 44 #include <inet/ip_ire.h> 45 #include "sctp_impl.h" 46 #include "sctp_asconf.h" 47 48 ssize_t 49 sctp_link_abort(mblk_t *mp, uint16_t serror, char *details, size_t len, 50 int iserror, boolean_t tbit) 51 { 52 size_t alen; 53 mblk_t *amp; 54 sctp_chunk_hdr_t *acp; 55 sctp_parm_hdr_t *eph; 56 57 ASSERT(mp != NULL && mp->b_cont == NULL); 58 59 alen = sizeof (*acp) + (serror != 0 ? (sizeof (*eph) + len) : 0); 60 61 amp = allocb(alen, BPRI_MED); 62 if (amp == NULL) { 63 return (-1); 64 } 65 66 amp->b_wptr = amp->b_rptr + alen; 67 68 /* Chunk header */ 69 acp = (sctp_chunk_hdr_t *)amp->b_rptr; 70 acp->sch_id = iserror ? CHUNK_ERROR : CHUNK_ABORT; 71 acp->sch_flags = 0; 72 acp->sch_len = htons(alen); 73 if (tbit) 74 SCTP_SET_TBIT(acp); 75 76 linkb(mp, amp); 77 78 if (serror == 0) { 79 return (alen); 80 } 81 82 eph = (sctp_parm_hdr_t *)(acp + 1); 83 eph->sph_type = htons(serror); 84 eph->sph_len = htons(len + sizeof (*eph)); 85 86 if (len > 0) { 87 bcopy(details, eph + 1, len); 88 } 89 90 /* XXX pad */ 91 92 return (alen); 93 } 94 95 void 96 sctp_user_abort(sctp_t *sctp, mblk_t *data) 97 { 98 mblk_t *mp; 99 int len, hdrlen; 100 char *cause; 101 sctp_faddr_t *fp = sctp->sctp_current; 102 sctp_stack_t *sctps = sctp->sctp_sctps; 103 104 mp = sctp_make_mp(sctp, fp, 0); 105 if (mp == NULL) { 106 SCTP_KSTAT(sctps, sctp_send_user_abort_failed); 107 return; 108 } 109 110 /* 111 * Create abort chunk. 112 */ 113 if (data) { 114 if (fp->isv4) { 115 hdrlen = sctp->sctp_hdr_len; 116 } else { 117 hdrlen = sctp->sctp_hdr6_len; 118 } 119 hdrlen += sizeof (sctp_chunk_hdr_t) + sizeof (sctp_parm_hdr_t); 120 cause = (char *)data->b_rptr; 121 len = data->b_wptr - data->b_rptr; 122 123 if (len + hdrlen > fp->sfa_pmss) { 124 len = fp->sfa_pmss - hdrlen; 125 } 126 } else { 127 cause = NULL; 128 len = 0; 129 } 130 /* 131 * Since it is a user abort, we should have the sctp_t and hence 132 * the correct verification tag. So we should not set the T-bit 133 * in the ABORT. 134 */ 135 if ((len = sctp_link_abort(mp, SCTP_ERR_USER_ABORT, cause, len, 0, 136 B_FALSE)) < 0) { 137 freemsg(mp); 138 return; 139 } 140 sctp_set_iplen(sctp, mp); 141 BUMP_MIB(&sctps->sctps_mib, sctpAborted); 142 BUMP_LOCAL(sctp->sctp_opkts); 143 BUMP_LOCAL(sctp->sctp_obchunks); 144 145 CONN_INC_REF(sctp->sctp_connp); 146 mp->b_flag |= MSGHASREF; 147 IP_PUT(mp, sctp->sctp_connp, fp->isv4); 148 149 sctp_assoc_event(sctp, SCTP_COMM_LOST, 0, NULL); 150 sctp_clean_death(sctp, ECONNABORTED); 151 } 152 153 /* 154 * If iserror == 0, sends an abort. If iserror != 0, sends an error. 155 */ 156 void 157 sctp_send_abort(sctp_t *sctp, uint32_t vtag, uint16_t serror, char *details, 158 size_t len, mblk_t *inmp, int iserror, boolean_t tbit) 159 { 160 161 mblk_t *hmp; 162 uint32_t ip_hdr_len; 163 ipha_t *iniph; 164 ipha_t *ahiph; 165 ip6_t *inip6h; 166 ip6_t *ahip6h; 167 sctp_hdr_t *sh; 168 sctp_hdr_t *insh; 169 size_t ahlen; 170 uchar_t *p; 171 ssize_t alen; 172 int isv4; 173 ire_t *ire; 174 irb_t *irb; 175 ts_label_t *tsl; 176 conn_t *connp; 177 cred_t *cr = NULL; 178 sctp_stack_t *sctps = sctp->sctp_sctps; 179 ip_stack_t *ipst; 180 181 isv4 = (IPH_HDR_VERSION(inmp->b_rptr) == IPV4_VERSION); 182 if (isv4) { 183 ahlen = sctp->sctp_hdr_len; 184 } else { 185 ahlen = sctp->sctp_hdr6_len; 186 } 187 188 /* 189 * If this is a labeled system, then check to see if we're allowed to 190 * send a response to this particular sender. If not, then just drop. 191 */ 192 if (is_system_labeled() && !tsol_can_reply_error(inmp)) 193 return; 194 195 hmp = allocb_cred(sctps->sctps_wroff_xtra + ahlen, 196 CONN_CRED(sctp->sctp_connp)); 197 if (hmp == NULL) { 198 /* XXX no resources */ 199 return; 200 } 201 202 /* copy in the IP / SCTP header */ 203 p = hmp->b_rptr + sctps->sctps_wroff_xtra; 204 hmp->b_rptr = p; 205 hmp->b_wptr = p + ahlen; 206 if (isv4) { 207 bcopy(sctp->sctp_iphc, p, sctp->sctp_hdr_len); 208 /* 209 * Composite is likely incomplete at this point, so pull 210 * info from the incoming IP / SCTP headers. 211 */ 212 ahiph = (ipha_t *)p; 213 iniph = (ipha_t *)inmp->b_rptr; 214 ip_hdr_len = IPH_HDR_LENGTH(inmp->b_rptr); 215 216 sh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr_len); 217 ASSERT(OK_32PTR(sh)); 218 219 insh = (sctp_hdr_t *)((uchar_t *)iniph + ip_hdr_len); 220 ASSERT(OK_32PTR(insh)); 221 222 /* Copy in the peer's IP addr */ 223 ahiph->ipha_dst = iniph->ipha_src; 224 ahiph->ipha_src = iniph->ipha_dst; 225 } else { 226 bcopy(sctp->sctp_iphc6, p, sctp->sctp_hdr6_len); 227 ahip6h = (ip6_t *)p; 228 inip6h = (ip6_t *)inmp->b_rptr; 229 ip_hdr_len = ip_hdr_length_v6(inmp, inip6h); 230 231 sh = (sctp_hdr_t *)(p + sctp->sctp_ip_hdr6_len); 232 ASSERT(OK_32PTR(sh)); 233 234 insh = (sctp_hdr_t *)((uchar_t *)inip6h + ip_hdr_len); 235 ASSERT(OK_32PTR(insh)); 236 237 /* Copy in the peer's IP addr */ 238 ahip6h->ip6_dst = inip6h->ip6_src; 239 ahip6h->ip6_src = inip6h->ip6_dst; 240 } 241 242 /* Fill in the holes in the SCTP common header */ 243 sh->sh_sport = insh->sh_dport; 244 sh->sh_dport = insh->sh_sport; 245 sh->sh_verf = vtag; 246 247 /* Link in the abort chunk */ 248 if ((alen = sctp_link_abort(hmp, serror, details, len, iserror, tbit)) 249 < 0) { 250 freemsg(hmp); 251 return; 252 } 253 254 if (isv4) { 255 ahiph->ipha_length = htons(ahlen + alen); 256 } else { 257 ahip6h->ip6_plen = htons(alen + sizeof (*sh)); 258 } 259 260 BUMP_MIB(&sctps->sctps_mib, sctpAborted); 261 BUMP_LOCAL(sctp->sctp_obchunks); 262 263 ipst = sctps->sctps_netstack->netstack_ip; 264 connp = sctp->sctp_connp; 265 if (is_system_labeled() && (cr = DB_CRED(inmp)) != NULL && 266 crgetlabel(cr) != NULL) { 267 int err; 268 boolean_t exempt = connp->conn_mac_exempt; 269 270 if (isv4) 271 err = tsol_check_label(cr, &hmp, exempt, ipst); 272 else 273 err = tsol_check_label_v6(cr, &hmp, exempt, ipst); 274 if (err != 0) { 275 freemsg(hmp); 276 return; 277 } 278 } 279 280 /* Stash the conn ptr info. for IP */ 281 SCTP_STASH_IPINFO(hmp, NULL); 282 283 CONN_INC_REF(connp); 284 hmp->b_flag |= MSGHASREF; 285 IP_PUT(hmp, connp, sctp->sctp_current == NULL ? B_TRUE : 286 sctp->sctp_current->isv4); 287 /* 288 * Let's just mark the IRE for this destination as temporary 289 * to prevent any DoS attack. 290 */ 291 tsl = cr == NULL ? NULL : crgetlabel(cr); 292 if (isv4) { 293 ire = ire_cache_lookup(iniph->ipha_src, sctp->sctp_zoneid, tsl, 294 ipst); 295 } else { 296 ire = ire_cache_lookup_v6(&inip6h->ip6_src, sctp->sctp_zoneid, 297 tsl, ipst); 298 } 299 /* 300 * In the normal case the ire would be non-null, however it could be 301 * null, say, if IP needs to resolve the gateway for this address. We 302 * only care about IRE_CACHE. 303 */ 304 if (ire == NULL) 305 return; 306 if (ire->ire_type != IRE_CACHE) { 307 ire_refrele(ire); 308 return; 309 } 310 irb = ire->ire_bucket; 311 /* ire_lock is not needed, as ire_marks is protected by irb_lock */ 312 rw_enter(&irb->irb_lock, RW_WRITER); 313 /* 314 * Only increment the temporary IRE count if the original 315 * IRE is not already marked temporary. 316 */ 317 if (!(ire->ire_marks & IRE_MARK_TEMPORARY)) { 318 irb->irb_tmp_ire_cnt++; 319 ire->ire_marks |= IRE_MARK_TEMPORARY; 320 } 321 rw_exit(&irb->irb_lock); 322 ire_refrele(ire); 323 } 324 325 /*ARGSUSED*/ 326 mblk_t * 327 sctp_make_err(sctp_t *sctp, uint16_t serror, void *details, size_t len) 328 { 329 330 mblk_t *emp; 331 size_t elen; 332 sctp_chunk_hdr_t *ecp; 333 sctp_parm_hdr_t *eph; 334 int pad; 335 336 if ((pad = len % SCTP_ALIGN) != 0) { 337 pad = SCTP_ALIGN - pad; 338 } 339 340 elen = sizeof (*ecp) + sizeof (*eph) + len; 341 emp = allocb(elen + pad, BPRI_MED); 342 if (emp == NULL) { 343 return (NULL); 344 } 345 346 emp->b_wptr = emp->b_rptr + elen + pad; 347 348 /* Chunk header */ 349 ecp = (sctp_chunk_hdr_t *)emp->b_rptr; 350 ecp->sch_id = CHUNK_ERROR; 351 ecp->sch_flags = 0; 352 ecp->sch_len = htons(elen); 353 354 eph = (sctp_parm_hdr_t *)(ecp + 1); 355 eph->sph_type = htons(serror); 356 eph->sph_len = htons(len + sizeof (*eph)); 357 358 if (len > 0) { 359 bcopy(details, eph + 1, len); 360 } 361 362 if (pad != 0) { 363 bzero((uchar_t *)(eph + 1) + len, pad); 364 } 365 366 return (emp); 367 } 368 369 /* 370 * Called from sctp_input_data() to add one error chunk to the error 371 * chunks list. The error chunks list will be processed at the end 372 * of sctp_input_data() by calling sctp_process_err(). 373 */ 374 void 375 sctp_add_err(sctp_t *sctp, uint16_t serror, void *details, size_t len, 376 sctp_faddr_t *dest) 377 { 378 sctp_stack_t *sctps = sctp->sctp_sctps; 379 mblk_t *emp; 380 uint32_t emp_len; 381 uint32_t mss; 382 mblk_t *sendmp; 383 sctp_faddr_t *fp; 384 385 emp = sctp_make_err(sctp, serror, details, len); 386 if (emp == NULL) 387 return; 388 emp_len = MBLKL(emp); 389 if (sctp->sctp_err_chunks != NULL) { 390 fp = SCTP_CHUNK_DEST(sctp->sctp_err_chunks); 391 } else { 392 fp = dest; 393 SCTP_SET_CHUNK_DEST(emp, dest); 394 } 395 mss = fp->sfa_pmss; 396 397 /* 398 * If the current output packet cannot include the new error chunk, 399 * send out the current packet and then add the new error chunk 400 * to the new output packet. 401 */ 402 if (sctp->sctp_err_len + emp_len > mss) { 403 if ((sendmp = sctp_make_mp(sctp, fp, 0)) == NULL) { 404 SCTP_KSTAT(sctps, sctp_send_err_failed); 405 /* Just free the latest error chunk. */ 406 freeb(emp); 407 return; 408 } 409 sendmp->b_cont = sctp->sctp_err_chunks; 410 sctp_set_iplen(sctp, sendmp); 411 sctp_add_sendq(sctp, sendmp); 412 413 sctp->sctp_err_chunks = emp; 414 sctp->sctp_err_len = emp_len; 415 SCTP_SET_CHUNK_DEST(emp, dest); 416 } else { 417 if (sctp->sctp_err_chunks != NULL) 418 linkb(sctp->sctp_err_chunks, emp); 419 else 420 sctp->sctp_err_chunks = emp; 421 sctp->sctp_err_len += emp_len; 422 } 423 /* Assume that we will send it out... */ 424 BUMP_LOCAL(sctp->sctp_obchunks); 425 } 426 427 /* 428 * Called from sctp_input_data() to send out error chunks created during 429 * the processing of all the chunks in an incoming packet. 430 */ 431 void 432 sctp_process_err(sctp_t *sctp) 433 { 434 sctp_stack_t *sctps = sctp->sctp_sctps; 435 mblk_t *errmp; 436 mblk_t *sendmp; 437 438 ASSERT(sctp->sctp_err_chunks != NULL); 439 errmp = sctp->sctp_err_chunks; 440 if ((sendmp = sctp_make_mp(sctp, SCTP_CHUNK_DEST(errmp), 0)) == NULL) { 441 SCTP_KSTAT(sctps, sctp_send_err_failed); 442 freemsg(errmp); 443 goto done; 444 } 445 sendmp->b_cont = errmp; 446 sctp_set_iplen(sctp, sendmp); 447 sctp_add_sendq(sctp, sendmp); 448 done: 449 sctp->sctp_err_chunks = NULL; 450 sctp->sctp_err_len = 0; 451 } 452 453 /* 454 * Returns 0 on non-fatal error, otherwise a system error on fatal 455 * error. 456 */ 457 int 458 sctp_handle_error(sctp_t *sctp, sctp_hdr_t *sctph, sctp_chunk_hdr_t *ch, 459 mblk_t *mp) 460 { 461 sctp_parm_hdr_t *errh; 462 sctp_chunk_hdr_t *uch; 463 464 if (ch->sch_len == htons(sizeof (*ch))) { 465 /* no error cause given */ 466 return (0); 467 } 468 errh = (sctp_parm_hdr_t *)(ch + 1); 469 sctp_error_event(sctp, ch); 470 471 switch (errh->sph_type) { 472 /* 473 * Both BAD_SID and NO_USR_DATA errors 474 * indicate a serious bug in our stack, 475 * so complain and abort the association. 476 */ 477 case SCTP_ERR_BAD_SID: 478 cmn_err(CE_WARN, "BUG! send to invalid SID"); 479 sctp_send_abort(sctp, sctph->sh_verf, 0, NULL, 0, mp, 0, 0); 480 return (ECONNABORTED); 481 case SCTP_ERR_NO_USR_DATA: 482 cmn_err(CE_WARN, "BUG! no usr data"); 483 sctp_send_abort(sctp, sctph->sh_verf, 0, NULL, 0, mp, 0, 0); 484 return (ECONNABORTED); 485 case SCTP_ERR_UNREC_CHUNK: 486 /* Pull out the unrecognized chunk type */ 487 if (ntohs(errh->sph_len) < (sizeof (*errh) + sizeof (*uch))) { 488 /* Not enough to process */ 489 return (0); 490 } 491 uch = (sctp_chunk_hdr_t *)(errh + 1); 492 if (uch->sch_id == CHUNK_ASCONF) { 493 /* Turn on ASCONF sending */ 494 sctp->sctp_understands_asconf = B_FALSE; 495 /* 496 * Hand off to asconf to clear out the unacked 497 * asconf chunk. 498 */ 499 if (ntohs(uch->sch_len) != 500 (ntohs(errh->sph_len) - sizeof (*errh))) { 501 /* malformed */ 502 dprint(0, ("Malformed Unrec Chunk error\n")); 503 return (0); 504 } 505 sctp_asconf_free_cxmit(sctp, uch); 506 return (0); 507 } 508 /* Else drop it */ 509 break; 510 default: 511 break; 512 } 513 514 return (0); 515 } 516