1 /*- 2 * Copyright (c) 2009 Sam Leffler, Errno Consulting 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 /* 30 * IEEE 802.11 radiotap support. 31 */ 32 #include "opt_wlan.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/mbuf.h> 37 #include <sys/malloc.h> 38 #include <sys/endian.h> 39 #include <sys/kernel.h> 40 41 #include <sys/socket.h> 42 43 #include <net/bpf.h> 44 #include <net/if.h> 45 #include <net/if_llc.h> 46 #include <net/if_media.h> 47 48 #include <net80211/ieee80211_var.h> 49 50 static int radiotap_offset(struct ieee80211_radiotap_header *, int); 51 52 void 53 ieee80211_radiotap_attach(struct ieee80211com *ic, 54 struct ieee80211_radiotap_header *th, int tlen, uint32_t tx_radiotap, 55 struct ieee80211_radiotap_header *rh, int rlen, uint32_t rx_radiotap) 56 { 57 #define B(_v) (1<<(_v)) 58 int off; 59 60 th->it_len = htole16(roundup2(tlen, sizeof(uint32_t))); 61 th->it_present = htole32(tx_radiotap); 62 ic->ic_th = th; 63 /* calculate offset to channel data */ 64 off = -1; 65 if (tx_radiotap & B(IEEE80211_RADIOTAP_CHANNEL)) 66 off = radiotap_offset(th, IEEE80211_RADIOTAP_CHANNEL); 67 else if (tx_radiotap & B(IEEE80211_RADIOTAP_XCHANNEL)) 68 off = radiotap_offset(th, IEEE80211_RADIOTAP_XCHANNEL); 69 if (off == -1) { 70 if_printf(ic->ic_ifp, "%s: no tx channel, radiotap 0x%x", 71 __func__, tx_radiotap); 72 /* NB: we handle this case but data will have no chan spec */ 73 } else 74 ic->ic_txchan = ((uint8_t *) th) + off; 75 76 rh->it_len = htole16(roundup2(rlen, sizeof(uint32_t))); 77 rh->it_present = htole32(rx_radiotap); 78 ic->ic_rh = rh; 79 /* calculate offset to channel data */ 80 off = -1; 81 if (rx_radiotap & B(IEEE80211_RADIOTAP_CHANNEL)) 82 off = radiotap_offset(rh, IEEE80211_RADIOTAP_CHANNEL); 83 else if (rx_radiotap & B(IEEE80211_RADIOTAP_XCHANNEL)) 84 off = radiotap_offset(rh, IEEE80211_RADIOTAP_XCHANNEL); 85 if (off == -1) { 86 if_printf(ic->ic_ifp, "%s: no rx channel, radiotap 0x%x", 87 __func__, rx_radiotap); 88 /* NB: we handle this case but data will have no chan spec */ 89 } else 90 ic->ic_rxchan = ((uint8_t *) rh) + off; 91 #undef B 92 } 93 94 void 95 ieee80211_radiotap_detach(struct ieee80211com *ic) 96 { 97 } 98 99 void 100 ieee80211_radiotap_vattach(struct ieee80211vap *vap) 101 { 102 struct ieee80211com *ic = vap->iv_ic; 103 struct ieee80211_radiotap_header *th = ic->ic_th; 104 105 if (th != NULL && ic->ic_rh != NULL) { 106 /* radiotap DLT for raw 802.11 frames */ 107 bpfattach2(vap->iv_ifp, DLT_IEEE802_11_RADIO, 108 sizeof(struct ieee80211_frame) + le16toh(th->it_len), 109 &vap->iv_rawbpf); 110 } 111 } 112 113 void 114 ieee80211_radiotap_vdetach(struct ieee80211vap *vap) 115 { 116 /* NB: bpfattach is called by ether_ifdetach and claims all taps */ 117 } 118 119 static void 120 set_channel(void *p, const struct ieee80211_channel *c) 121 { 122 struct { 123 uint16_t freq; 124 uint16_t flags; 125 } *rc = p; 126 127 rc->freq = htole16(c->ic_freq); 128 rc->flags = htole16(c->ic_flags); 129 } 130 131 static void 132 set_xchannel(void *p, const struct ieee80211_channel *c) 133 { 134 struct { 135 uint32_t flags; 136 uint16_t freq; 137 uint8_t ieee; 138 uint8_t maxpow; 139 } *rc = p; 140 141 rc->flags = htole32(c->ic_flags); 142 rc->freq = htole16(c->ic_freq); 143 rc->ieee = c->ic_ieee; 144 rc->maxpow = c->ic_maxregpower; 145 } 146 147 /* 148 * Update radiotap state on channel change. 149 */ 150 void 151 ieee80211_radiotap_chan_change(struct ieee80211com *ic) 152 { 153 if (ic->ic_rxchan != NULL) { 154 struct ieee80211_radiotap_header *rh = ic->ic_rh; 155 156 if (rh->it_present & (1<<IEEE80211_RADIOTAP_XCHANNEL)) 157 set_xchannel(ic->ic_rxchan, ic->ic_curchan); 158 else if (rh->it_present & (1<<IEEE80211_RADIOTAP_CHANNEL)) 159 set_channel(ic->ic_rxchan, ic->ic_curchan); 160 } 161 if (ic->ic_txchan != NULL) { 162 struct ieee80211_radiotap_header *th = ic->ic_th; 163 164 if (th->it_present & (1<<IEEE80211_RADIOTAP_XCHANNEL)) 165 set_xchannel(ic->ic_txchan, ic->ic_curchan); 166 else if (th->it_present & (1<<IEEE80211_RADIOTAP_CHANNEL)) 167 set_channel(ic->ic_txchan, ic->ic_curchan); 168 } 169 } 170 171 #if 0 172 static void 173 dispatch_radiotap(struct ieee80211vap *vap0, struct mbuf *m, 174 struct ieee80211_radiotap_header *rh) 175 { 176 struct ieee80211com *ic = vap0->iv_ic; 177 int len = le16toh(rh->it_len); 178 179 if (vap0->iv_flags_ext & IEEE80211_FEXT_BPF) 180 bpf_mtap2(vap0->iv_rawbpf, rh, len, m); 181 /* 182 * Spam monitor mode vaps with unicast frames. Multicast 183 * frames are handled by passing through ieee80211_input_all 184 * which distributes copies to the monitor mode vaps to be 185 * processed above. 186 */ 187 if (ic->ic_montaps != 0 && (m->m_flags & M_BCAST) == 0) { 188 struct ieee80211vap *vap; 189 TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) { 190 if (vap != vap0 && 191 vap->iv_opmode == IEEE80211_M_MONITOR && 192 (vap->iv_flags_ext & IEEE80211_FEXT_BPF) && 193 vap->iv_state != IEEE80211_S_INIT) 194 bpf_mtap2(vap->iv_rawbpf, rh, len, m); 195 } 196 } 197 } 198 #endif 199 200 /* 201 * Distribute radiotap data (+packet) to all monitor mode 202 * vaps with an active tap other than vap0. 203 */ 204 static void 205 spam_vaps(struct ieee80211vap *vap0, struct mbuf *m, 206 struct ieee80211_radiotap_header *rh, int len) 207 { 208 struct ieee80211com *ic = vap0->iv_ic; 209 struct ieee80211vap *vap; 210 211 TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) { 212 if (vap != vap0 && 213 vap->iv_opmode == IEEE80211_M_MONITOR && 214 (vap->iv_flags_ext & IEEE80211_FEXT_BPF) && 215 vap->iv_state != IEEE80211_S_INIT) 216 bpf_mtap2(vap->iv_rawbpf, rh, len, m); 217 } 218 } 219 220 /* 221 * Dispatch radiotap data for transmitted packet. 222 */ 223 void 224 ieee80211_radiotap_tx(struct ieee80211vap *vap0, struct mbuf *m) 225 { 226 struct ieee80211com *ic = vap0->iv_ic; 227 struct ieee80211_radiotap_header *th = ic->ic_th; 228 int len; 229 230 KASSERT(th != NULL, ("no tx radiotap header")); 231 len = le16toh(th->it_len); 232 233 if (vap0->iv_flags_ext & IEEE80211_FEXT_BPF) 234 bpf_mtap2(vap0->iv_rawbpf, th, len, m); 235 /* 236 * Spam monitor mode vaps. 237 */ 238 if (ic->ic_montaps != 0) 239 spam_vaps(vap0, m, th, len); 240 } 241 242 /* 243 * Dispatch radiotap data for received packet. 244 */ 245 void 246 ieee80211_radiotap_rx(struct ieee80211vap *vap0, struct mbuf *m) 247 { 248 struct ieee80211com *ic = vap0->iv_ic; 249 struct ieee80211_radiotap_header *rh = ic->ic_rh; 250 int len; 251 252 KASSERT(rh != NULL, ("no rx radiotap header")); 253 len = le16toh(rh->it_len); 254 255 if (vap0->iv_flags_ext & IEEE80211_FEXT_BPF) 256 bpf_mtap2(vap0->iv_rawbpf, rh, len, m); 257 /* 258 * Spam monitor mode vaps with unicast frames. Multicast 259 * frames are handled by passing through ieee80211_input_all 260 * which distributes copies to the monitor mode vaps. 261 */ 262 if (ic->ic_montaps != 0 && (m->m_flags & M_BCAST) == 0) 263 spam_vaps(vap0, m, rh, len); 264 } 265 266 /* 267 * Dispatch radiotap data for a packet received outside the normal 268 * rx processing path; this is used, for example, to handle frames 269 * received with errors that would otherwise be dropped. 270 */ 271 void 272 ieee80211_radiotap_rx_all(struct ieee80211com *ic, struct mbuf *m) 273 { 274 struct ieee80211_radiotap_header *rh = ic->ic_rh; 275 int len = le16toh(rh->it_len); 276 struct ieee80211vap *vap; 277 278 /* XXX locking? */ 279 TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) { 280 if (ieee80211_radiotap_active_vap(vap) && 281 vap->iv_state != IEEE80211_S_INIT) 282 bpf_mtap2(vap->iv_rawbpf, rh, len, m); 283 } 284 } 285 286 /* 287 * Return the offset of the specified item in the radiotap 288 * header description. If the item is not present or is not 289 * known -1 is returned. 290 */ 291 static int 292 radiotap_offset(struct ieee80211_radiotap_header *rh, int item) 293 { 294 static const struct { 295 size_t align, width; 296 } items[] = { 297 [IEEE80211_RADIOTAP_TSFT] = { 298 .align = sizeof(uint64_t), 299 .width = sizeof(uint64_t), 300 }, 301 [IEEE80211_RADIOTAP_FLAGS] = { 302 .align = sizeof(uint8_t), 303 .width = sizeof(uint8_t), 304 }, 305 [IEEE80211_RADIOTAP_RATE] = { 306 .align = sizeof(uint8_t), 307 .width = sizeof(uint8_t), 308 }, 309 [IEEE80211_RADIOTAP_CHANNEL] = { 310 .align = sizeof(uint16_t), 311 .width = 2*sizeof(uint16_t), 312 }, 313 [IEEE80211_RADIOTAP_FHSS] = { 314 .align = sizeof(uint16_t), 315 .width = sizeof(uint16_t), 316 }, 317 [IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = { 318 .align = sizeof(uint8_t), 319 .width = sizeof(uint8_t), 320 }, 321 [IEEE80211_RADIOTAP_DBM_ANTNOISE] = { 322 .align = sizeof(uint8_t), 323 .width = sizeof(uint8_t), 324 }, 325 [IEEE80211_RADIOTAP_LOCK_QUALITY] = { 326 .align = sizeof(uint16_t), 327 .width = sizeof(uint16_t), 328 }, 329 [IEEE80211_RADIOTAP_TX_ATTENUATION] = { 330 .align = sizeof(uint16_t), 331 .width = sizeof(uint16_t), 332 }, 333 [IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = { 334 .align = sizeof(uint16_t), 335 .width = sizeof(uint16_t), 336 }, 337 [IEEE80211_RADIOTAP_DBM_TX_POWER] = { 338 .align = sizeof(uint8_t), 339 .width = sizeof(uint8_t), 340 }, 341 [IEEE80211_RADIOTAP_ANTENNA] = { 342 .align = sizeof(uint8_t), 343 .width = sizeof(uint8_t), 344 }, 345 [IEEE80211_RADIOTAP_DB_ANTSIGNAL] = { 346 .align = sizeof(uint8_t), 347 .width = sizeof(uint8_t), 348 }, 349 [IEEE80211_RADIOTAP_DB_ANTNOISE] = { 350 .align = sizeof(uint8_t), 351 .width = sizeof(uint8_t), 352 }, 353 [IEEE80211_RADIOTAP_XCHANNEL] = { 354 .align = sizeof(uint32_t), 355 .width = 2*sizeof(uint32_t), 356 }, 357 }; 358 uint32_t present = le32toh(rh->it_present); 359 int off, i; 360 361 off = sizeof(struct ieee80211_radiotap_header); 362 for (i = 0; i < IEEE80211_RADIOTAP_EXT; i++) { 363 if ((present & (1<<i)) == 0) 364 continue; 365 if (items[i].align == 0) { 366 /* NB: unidentified element, don't guess */ 367 printf("%s: unknown item %d\n", __func__, i); 368 return -1; 369 } 370 off = roundup2(off, items[i].align); 371 if (i == item) { 372 if (off + items[i].width > le16toh(rh->it_len)) { 373 /* NB: item does not fit in header data */ 374 printf("%s: item %d not in header data, " 375 "off %d width %zu len %d\n", __func__, i, 376 off, items[i].width, le16toh(rh->it_len)); 377 return -1; 378 } 379 return off; 380 } 381 off += items[i].width; 382 } 383 return -1; 384 } 385