ieee80211_output.c revision 119150
1/*- 2 * Copyright (c) 2001 Atsushi Onoe 3 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting 4 * 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 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * Alternatively, this software may be distributed under the terms of the 18 * GNU General Public License ("GPL") version 2 as published by the Free 19 * Software Foundation. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33#include <sys/cdefs.h> 34__FBSDID("$FreeBSD: head/sys/net80211/ieee80211_output.c 119150 2003-08-19 22:17:04Z sam $"); 35 36#include "opt_inet.h" 37 38#include <sys/param.h> 39#include <sys/systm.h> 40#include <sys/mbuf.h> 41#include <sys/malloc.h> 42#include <sys/kernel.h> 43#include <sys/socket.h> 44#include <sys/sockio.h> 45#include <sys/endian.h> 46#include <sys/errno.h> 47#include <sys/bus.h> 48#include <sys/proc.h> 49#include <sys/sysctl.h> 50 51#include <machine/atomic.h> 52 53#include <net/if.h> 54#include <net/if_dl.h> 55#include <net/if_media.h> 56#include <net/if_arp.h> 57#include <net/ethernet.h> 58#include <net/if_llc.h> 59 60#include <net80211/ieee80211_var.h> 61 62#include <net/bpf.h> 63 64#ifdef INET 65#include <netinet/in.h> 66#include <netinet/if_ether.h> 67#endif 68 69/* 70 * Send a management frame to the specified node. The node pointer 71 * must have a reference as the pointer will be passed to the driver 72 * and potentially held for a long time. If the frame is successfully 73 * dispatched to the driver, then it is responsible for freeing the 74 * reference (and potentially free'ing up any associated storage). 75 */ 76static int 77ieee80211_mgmt_output(struct ifnet *ifp, struct ieee80211_node *ni, 78 struct mbuf *m, int type) 79{ 80 struct ieee80211com *ic = (void *)ifp; 81 struct ieee80211_frame *wh; 82 83 KASSERT(ni != NULL, ("null node")); 84 ni->ni_inact = 0; 85 86 /* 87 * Yech, hack alert! We want to pass the node down to the 88 * driver's start routine. If we don't do so then the start 89 * routine must immediately look it up again and that can 90 * cause a lock order reversal if, for example, this frame 91 * is being sent because the station is being timedout and 92 * the frame being sent is a DEAUTH message. We could stick 93 * this in an m_tag and tack that on to the mbuf. However 94 * that's rather expensive to do for every frame so instead 95 * we stuff it in the rcvif field since outbound frames do 96 * not (presently) use this. 97 */ 98 M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT); 99 if (m == NULL) 100 return ENOMEM; 101 KASSERT(m->m_pkthdr.rcvif == NULL, ("rcvif not null")); 102 m->m_pkthdr.rcvif = (void *)ni; 103 104 wh = mtod(m, struct ieee80211_frame *); 105 wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_MGT | type; 106 wh->i_fc[1] = IEEE80211_FC1_DIR_NODS; 107 *(u_int16_t *)wh->i_dur = 0; 108 *(u_int16_t *)wh->i_seq = 109 htole16(ni->ni_txseq << IEEE80211_SEQ_SEQ_SHIFT); 110 ni->ni_txseq++; 111 IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_macaddr); 112 IEEE80211_ADDR_COPY(wh->i_addr2, ic->ic_myaddr); 113 IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid); 114 115 if (ifp->if_flags & IFF_DEBUG) { 116 /* avoid to print too many frames */ 117 if (ic->ic_opmode == IEEE80211_M_IBSS || 118#ifdef IEEE80211_DEBUG 119 ieee80211_debug > 1 || 120#endif 121 (type & IEEE80211_FC0_SUBTYPE_MASK) != 122 IEEE80211_FC0_SUBTYPE_PROBE_RESP) 123 if_printf(ifp, "sending %s to %s on channel %u\n", 124 ieee80211_mgt_subtype_name[ 125 (type & IEEE80211_FC0_SUBTYPE_MASK) 126 >> IEEE80211_FC0_SUBTYPE_SHIFT], 127 ether_sprintf(ni->ni_macaddr), 128 ieee80211_chan2ieee(ic, ni->ni_chan)); 129 } 130 131 IF_ENQUEUE(&ic->ic_mgtq, m); 132 ifp->if_timer = 1; 133 (*ifp->if_start)(ifp); 134 return 0; 135} 136 137/* 138 * Encapsulate an outbound data frame. The mbuf chain is updated and 139 * a reference to the destination node is returned. If an error is 140 * encountered NULL is returned and the node reference will also be NULL. 141 * 142 * NB: The caller is responsible for free'ing a returned node reference. 143 * The convention is ic_bss is not reference counted; the caller must 144 * maintain that. 145 */ 146struct mbuf * 147ieee80211_encap(struct ifnet *ifp, struct mbuf *m, struct ieee80211_node **pni) 148{ 149 struct ieee80211com *ic = (void *)ifp; 150 struct ether_header eh; 151 struct ieee80211_frame *wh; 152 struct ieee80211_node *ni = NULL; 153 struct llc *llc; 154 155 if (m->m_len < sizeof(struct ether_header)) { 156 m = m_pullup(m, sizeof(struct ether_header)); 157 if (m == NULL) { 158 /* XXX statistic */ 159 goto bad; 160 } 161 } 162 memcpy(&eh, mtod(m, caddr_t), sizeof(struct ether_header)); 163 164 if (ic->ic_opmode != IEEE80211_M_STA) { 165 ni = ieee80211_find_node(ic, eh.ether_dhost); 166 if (ni == NULL) { 167 /* 168 * When not in station mode the 169 * destination address should always be 170 * in the node table unless this is a 171 * multicast/broadcast frame. 172 */ 173 if (!IEEE80211_IS_MULTICAST(eh.ether_dhost)) { 174 /* ic->ic_stats.st_tx_nonode++; XXX statistic */ 175 goto bad; 176 } 177 ni = ic->ic_bss; 178 } 179 } else 180 ni = ic->ic_bss; 181 ni->ni_inact = 0; 182 183 m_adj(m, sizeof(struct ether_header) - sizeof(struct llc)); 184 llc = mtod(m, struct llc *); 185 llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP; 186 llc->llc_control = LLC_UI; 187 llc->llc_snap.org_code[0] = 0; 188 llc->llc_snap.org_code[1] = 0; 189 llc->llc_snap.org_code[2] = 0; 190 llc->llc_snap.ether_type = eh.ether_type; 191 M_PREPEND(m, sizeof(struct ieee80211_frame), M_DONTWAIT); 192 if (m == NULL) 193 goto bad; 194 wh = mtod(m, struct ieee80211_frame *); 195 wh->i_fc[0] = IEEE80211_FC0_VERSION_0 | IEEE80211_FC0_TYPE_DATA; 196 *(u_int16_t *)wh->i_dur = 0; 197 *(u_int16_t *)wh->i_seq = 198 htole16(ni->ni_txseq << IEEE80211_SEQ_SEQ_SHIFT); 199 ni->ni_txseq++; 200 switch (ic->ic_opmode) { 201 case IEEE80211_M_STA: 202 wh->i_fc[1] = IEEE80211_FC1_DIR_TODS; 203 IEEE80211_ADDR_COPY(wh->i_addr1, ni->ni_bssid); 204 IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost); 205 IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_dhost); 206 break; 207 case IEEE80211_M_IBSS: 208 case IEEE80211_M_AHDEMO: 209 wh->i_fc[1] = IEEE80211_FC1_DIR_NODS; 210 IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost); 211 IEEE80211_ADDR_COPY(wh->i_addr2, eh.ether_shost); 212 IEEE80211_ADDR_COPY(wh->i_addr3, ni->ni_bssid); 213 break; 214 case IEEE80211_M_HOSTAP: 215 wh->i_fc[1] = IEEE80211_FC1_DIR_FROMDS; 216 IEEE80211_ADDR_COPY(wh->i_addr1, eh.ether_dhost); 217 IEEE80211_ADDR_COPY(wh->i_addr2, ni->ni_bssid); 218 IEEE80211_ADDR_COPY(wh->i_addr3, eh.ether_shost); 219 break; 220 case IEEE80211_M_MONITOR: 221 goto bad; 222 } 223 *pni = ni; 224 return m; 225bad: 226 if (m != NULL) 227 m_freem(m); 228 if (ni && ni != ic->ic_bss) 229 ieee80211_free_node(ic, ni); 230 *pni = NULL; 231 return NULL; 232} 233 234/* 235 * Add a supported rates element id to a frame. 236 */ 237u_int8_t * 238ieee80211_add_rates(u_int8_t *frm, const struct ieee80211_rateset *rs) 239{ 240 int nrates; 241 242 *frm++ = IEEE80211_ELEMID_RATES; 243 nrates = rs->rs_nrates; 244 if (nrates > IEEE80211_RATE_SIZE) 245 nrates = IEEE80211_RATE_SIZE; 246 *frm++ = nrates; 247 memcpy(frm, rs->rs_rates, nrates); 248 return frm + nrates; 249} 250 251/* 252 * Add an extended supported rates element id to a frame. 253 */ 254u_int8_t * 255ieee80211_add_xrates(u_int8_t *frm, const struct ieee80211_rateset *rs) 256{ 257 /* 258 * Add an extended supported rates element if operating in 11g mode. 259 */ 260 if (rs->rs_nrates > IEEE80211_RATE_SIZE) { 261 int nrates = rs->rs_nrates - IEEE80211_RATE_SIZE; 262 *frm++ = IEEE80211_ELEMID_XRATES; 263 *frm++ = nrates; 264 memcpy(frm, rs->rs_rates + IEEE80211_RATE_SIZE, nrates); 265 frm += nrates; 266 } 267 return frm; 268} 269 270/* 271 * Add an ssid elemet to a frame. 272 */ 273static u_int8_t * 274ieee80211_add_ssid(u_int8_t *frm, const u_int8_t *ssid, u_int len) 275{ 276 *frm++ = IEEE80211_ELEMID_SSID; 277 *frm++ = len; 278 memcpy(frm, ssid, len); 279 return frm + len; 280} 281 282static struct mbuf * 283ieee80211_getmbuf(int flags, int type, u_int pktlen) 284{ 285 struct mbuf *m; 286 287 if (pktlen > MHLEN) 288 MGETHDR(m, flags, type); 289 else 290 m = m_getcl(flags, type, M_PKTHDR); 291 return m; 292} 293 294/* 295 * Send a management frame. The node is for the destination (or ic_bss 296 * when in station mode). Nodes other than ic_bss have their reference 297 * count bumped to reflect our use for an indeterminant time. 298 */ 299int 300ieee80211_send_mgmt(struct ieee80211com *ic, struct ieee80211_node *ni, 301 int type, int arg) 302{ 303#define senderr(_x) do { ret = _x; goto bad; } while (0) 304 struct ifnet *ifp = &ic->ic_if; 305 struct mbuf *m; 306 u_int8_t *frm; 307 enum ieee80211_phymode mode; 308 u_int16_t capinfo; 309 int ret, timer; 310 311 KASSERT(ni != NULL, ("null node")); 312 313 /* 314 * Hold a reference on the node so it doesn't go away until after 315 * the xmit is complete all the way in the driver. On error we 316 * will remove our reference. 317 */ 318 if (ni != ic->ic_bss) 319 ieee80211_ref_node(ni); 320 timer = 0; 321 switch (type) { 322 case IEEE80211_FC0_SUBTYPE_PROBE_REQ: 323 /* 324 * prreq frame format 325 * [tlv] ssid 326 * [tlv] supported rates 327 * [tlv] extended supported rates 328 */ 329 m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA, 330 2 + ic->ic_des_esslen 331 + 2 + IEEE80211_RATE_SIZE 332 + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)); 333 if (m == NULL) 334 senderr(ENOMEM); 335 m->m_data += sizeof(struct ieee80211_frame); 336 frm = mtod(m, u_int8_t *); 337 frm = ieee80211_add_ssid(frm, ic->ic_des_essid, ic->ic_des_esslen); 338 mode = ieee80211_chan2mode(ic, ni->ni_chan); 339 frm = ieee80211_add_rates(frm, &ic->ic_sup_rates[mode]); 340 frm = ieee80211_add_xrates(frm, &ic->ic_sup_rates[mode]); 341 m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *); 342 343 timer = IEEE80211_TRANS_WAIT; 344 break; 345 346 case IEEE80211_FC0_SUBTYPE_PROBE_RESP: 347 /* 348 * probe response frame format 349 * [8] time stamp 350 * [2] beacon interval 351 * [2] cabability information 352 * [tlv] ssid 353 * [tlv] supported rates 354 * [tlv] parameter set (IBSS) 355 * [tlv] extended supported rates 356 */ 357 m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA, 358 8 + 2 + 2 + 2 359 + 2 + ni->ni_esslen 360 + 2 + IEEE80211_RATE_SIZE 361 + 6 362 + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)); 363 if (m == NULL) 364 senderr(ENOMEM); 365 m->m_data += sizeof(struct ieee80211_frame); 366 frm = mtod(m, u_int8_t *); 367 368 memset(frm, 0, 8); /* timestamp should be filled later */ 369 frm += 8; 370 *(u_int16_t *)frm = htole16(ic->ic_bss->ni_intval); 371 frm += 2; 372 if (ic->ic_opmode == IEEE80211_M_IBSS) 373 capinfo = IEEE80211_CAPINFO_IBSS; 374 else 375 capinfo = IEEE80211_CAPINFO_ESS; 376 if (ic->ic_flags & IEEE80211_F_WEPON) 377 capinfo |= IEEE80211_CAPINFO_PRIVACY; 378 *(u_int16_t *)frm = htole16(capinfo); 379 frm += 2; 380 381 frm = ieee80211_add_ssid(frm, ic->ic_bss->ni_essid, 382 ic->ic_bss->ni_esslen); 383 frm = ieee80211_add_rates(frm, &ic->ic_bss->ni_rates); 384 385 if (ic->ic_opmode == IEEE80211_M_IBSS) { 386 *frm++ = IEEE80211_ELEMID_IBSSPARMS; 387 *frm++ = 2; 388 *frm++ = 0; *frm++ = 0; /* TODO: ATIM window */ 389 } else { /* IEEE80211_M_HOSTAP */ 390 /* TODO: TIM */ 391 *frm++ = IEEE80211_ELEMID_TIM; 392 *frm++ = 4; /* length */ 393 *frm++ = 0; /* DTIM count */ 394 *frm++ = 1; /* DTIM period */ 395 *frm++ = 0; /* bitmap control */ 396 *frm++ = 0; /* Partial Virtual Bitmap (variable length) */ 397 } 398 frm = ieee80211_add_xrates(frm, &ic->ic_bss->ni_rates); 399 m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *); 400 break; 401 402 case IEEE80211_FC0_SUBTYPE_AUTH: 403 MGETHDR(m, M_DONTWAIT, MT_DATA); 404 if (m == NULL) 405 senderr(ENOMEM); 406 MH_ALIGN(m, 2 * 3); 407 m->m_pkthdr.len = m->m_len = 6; 408 frm = mtod(m, u_int8_t *); 409 /* TODO: shared key auth */ 410 ((u_int16_t *)frm)[0] = htole16(IEEE80211_AUTH_ALG_OPEN); 411 ((u_int16_t *)frm)[1] = htole16(arg); /* sequence number */ 412 ((u_int16_t *)frm)[2] = 0; /* status */ 413 if (ic->ic_opmode == IEEE80211_M_STA) 414 timer = IEEE80211_TRANS_WAIT; 415 break; 416 417 case IEEE80211_FC0_SUBTYPE_DEAUTH: 418 if (ifp->if_flags & IFF_DEBUG) 419 if_printf(ifp, "station %s deauthenticate (reason %d)\n", 420 ether_sprintf(ni->ni_macaddr), arg); 421 MGETHDR(m, M_DONTWAIT, MT_DATA); 422 if (m == NULL) 423 senderr(ENOMEM); 424 MH_ALIGN(m, 2); 425 m->m_pkthdr.len = m->m_len = 2; 426 *mtod(m, u_int16_t *) = htole16(arg); /* reason */ 427 break; 428 429 case IEEE80211_FC0_SUBTYPE_ASSOC_REQ: 430 case IEEE80211_FC0_SUBTYPE_REASSOC_REQ: 431 /* 432 * asreq frame format 433 * [2] capability information 434 * [2] listen interval 435 * [6*] current AP address (reassoc only) 436 * [tlv] ssid 437 * [tlv] supported rates 438 * [tlv] extended supported rates 439 */ 440 m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA, 441 sizeof(capinfo) 442 + sizeof(u_int16_t) 443 + IEEE80211_ADDR_LEN 444 + 2 + ni->ni_esslen 445 + 2 + IEEE80211_RATE_SIZE 446 + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)); 447 if (m == NULL) 448 senderr(ENOMEM); 449 m->m_data += sizeof(struct ieee80211_frame); 450 frm = mtod(m, u_int8_t *); 451 452 capinfo = 0; 453 if (ic->ic_opmode == IEEE80211_M_IBSS) 454 capinfo |= IEEE80211_CAPINFO_IBSS; 455 else /* IEEE80211_M_STA */ 456 capinfo |= IEEE80211_CAPINFO_ESS; 457 if (ic->ic_flags & IEEE80211_F_WEPON) 458 capinfo |= IEEE80211_CAPINFO_PRIVACY; 459 if (ic->ic_flags & IEEE80211_F_SHPREAMBLE) 460 capinfo |= IEEE80211_CAPINFO_SHORT_PREAMBLE; 461 if (ic->ic_flags & IEEE80211_F_SHSLOT) 462 capinfo |= IEEE80211_CAPINFO_SHORT_SLOTTIME; 463 *(u_int16_t *)frm = htole16(capinfo); 464 frm += 2; 465 466 *(u_int16_t *)frm = htole16(ic->ic_lintval); 467 frm += 2; 468 469 if (type == IEEE80211_FC0_SUBTYPE_REASSOC_REQ) { 470 IEEE80211_ADDR_COPY(frm, ic->ic_bss->ni_bssid); 471 frm += IEEE80211_ADDR_LEN; 472 } 473 474 frm = ieee80211_add_ssid(frm, ni->ni_essid, ni->ni_esslen); 475 frm = ieee80211_add_rates(frm, &ni->ni_rates); 476 frm = ieee80211_add_xrates(frm, &ni->ni_rates); 477 m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *); 478 479 timer = IEEE80211_TRANS_WAIT; 480 break; 481 482 case IEEE80211_FC0_SUBTYPE_ASSOC_RESP: 483 case IEEE80211_FC0_SUBTYPE_REASSOC_RESP: 484 /* 485 * asreq frame format 486 * [2] capability information 487 * [2] status 488 * [2] association ID 489 * [tlv] supported rates 490 * [tlv] extended supported rates 491 */ 492 m = ieee80211_getmbuf(M_DONTWAIT, MT_DATA, 493 sizeof(capinfo) 494 + sizeof(u_int16_t) 495 + sizeof(u_int16_t) 496 + 2 + IEEE80211_RATE_SIZE 497 + 2 + (IEEE80211_RATE_MAXSIZE - IEEE80211_RATE_SIZE)); 498 if (m == NULL) 499 senderr(ENOMEM); 500 m->m_data += sizeof(struct ieee80211_frame); 501 frm = mtod(m, u_int8_t *); 502 503 capinfo = IEEE80211_CAPINFO_ESS; 504 if (ic->ic_flags & IEEE80211_F_WEPON) 505 capinfo |= IEEE80211_CAPINFO_PRIVACY; 506 *(u_int16_t *)frm = htole16(capinfo); 507 frm += 2; 508 509 *(u_int16_t *)frm = htole16(arg); /* status */ 510 frm += 2; 511 512 if (arg == IEEE80211_STATUS_SUCCESS) 513 *(u_int16_t *)frm = htole16(ni->ni_associd); 514 frm += 2; 515 516 frm = ieee80211_add_rates(frm, &ni->ni_rates); 517 frm = ieee80211_add_xrates(frm, &ni->ni_rates); 518 m->m_pkthdr.len = m->m_len = frm - mtod(m, u_int8_t *); 519 break; 520 521 case IEEE80211_FC0_SUBTYPE_DISASSOC: 522 if (ifp->if_flags & IFF_DEBUG) 523 if_printf(ifp, "station %s disassociate (reason %d)\n", 524 ether_sprintf(ni->ni_macaddr), arg); 525 MGETHDR(m, M_DONTWAIT, MT_DATA); 526 if (m == NULL) 527 senderr(ENOMEM); 528 MH_ALIGN(m, 2); 529 m->m_pkthdr.len = m->m_len = 2; 530 *mtod(m, u_int16_t *) = htole16(arg); /* reason */ 531 break; 532 533 default: 534 IEEE80211_DPRINTF(("%s: invalid mgmt frame type %u\n", 535 __func__, type)); 536 senderr(EINVAL); 537 /* NOTREACHED */ 538 } 539 540 ret = ieee80211_mgmt_output(ifp, ni, m, type); 541 if (ret == 0) { 542 if (timer) 543 ic->ic_mgt_timer = timer; 544 } else { 545bad: 546 if (ni != ic->ic_bss) /* remove ref we added */ 547 ieee80211_free_node(ic, ni); 548 } 549 return ret; 550#undef senderr 551} 552