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 KASSERT(th != NULL, ("no radiotap setup")); 106 107 /* radiotap DLT for raw 802.11 frames */ 108 bpfattach2(vap->iv_ifp, DLT_IEEE802_11_RADIO, 109 sizeof(struct ieee80211_frame) + le16toh(th->it_len), 110 &vap->iv_rawbpf); 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 static void 172 dispatch_radiotap(struct ieee80211vap *vap0, struct mbuf *m, 173 struct ieee80211_radiotap_header *rh) 174 { 175 struct ieee80211com *ic = vap0->iv_ic; 176 int len = le16toh(rh->it_len); 177 178 if (ieee80211_radiotap_active_vap(vap0)) 179 bpf_mtap2(vap0->iv_rawbpf, rh, len, m); 180 if (ic->ic_monvaps) { 181 struct ieee80211vap *vap; 182 TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) { 183 if (vap->iv_opmode == IEEE80211_M_MONITOR && 184 vap != vap0 && ieee80211_radiotap_active_vap(vap)) 185 bpf_mtap2(vap->iv_rawbpf, rh, len, m); 186 } 187 } 188 } 189 190 /* 191 * Dispatch radiotap data for transmitted packet. 192 */ 193 void 194 ieee80211_radiotap_tx(struct ieee80211vap *vap0, struct mbuf *m) 195 { 196 dispatch_radiotap(vap0, m, vap0->iv_ic->ic_th); 197 } 198 199 /* 200 * Dispatch radiotap data for received packet. 201 */ 202 void 203 ieee80211_radiotap_rx(struct ieee80211vap *vap0, struct mbuf *m) 204 { 205 dispatch_radiotap(vap0, m, vap0->iv_ic->ic_rh); 206 } 207 208 /* 209 * Dispatch radiotap data for a packet received outside the normal 210 * rx processing path; this is used, for example, to handle frames 211 * received with errors that would otherwise be dropped. 212 */ 213 void 214 ieee80211_radiotap_rx_all(struct ieee80211com *ic, struct mbuf *m) 215 { 216 struct ieee80211_radiotap_header *rh = ic->ic_rh; 217 int len = le16toh(rh->it_len); 218 struct ieee80211vap *vap; 219 220 /* XXX locking? */ 221 TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) { 222 if (ieee80211_radiotap_active_vap(vap)) 223 bpf_mtap2(vap->iv_rawbpf, rh, len, m); 224 } 225 } 226 227 /* 228 * Return the offset of the specified item in the radiotap 229 * header description. If the item is not present or is not 230 * known -1 is returned. 231 */ 232 static int 233 radiotap_offset(struct ieee80211_radiotap_header *rh, int item) 234 { 235 static const struct { 236 size_t align, width; 237 } items[] = { 238 [IEEE80211_RADIOTAP_TSFT] = { 239 .align = sizeof(uint64_t), 240 .width = sizeof(uint64_t), 241 }, 242 [IEEE80211_RADIOTAP_FLAGS] = { 243 .align = sizeof(uint8_t), 244 .width = sizeof(uint8_t), 245 }, 246 [IEEE80211_RADIOTAP_RATE] = { 247 .align = sizeof(uint8_t), 248 .width = sizeof(uint8_t), 249 }, 250 [IEEE80211_RADIOTAP_CHANNEL] = { 251 .align = sizeof(uint16_t), 252 .width = 2*sizeof(uint16_t), 253 }, 254 [IEEE80211_RADIOTAP_FHSS] = { 255 .align = sizeof(uint16_t), 256 .width = sizeof(uint16_t), 257 }, 258 [IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = { 259 .align = sizeof(uint8_t), 260 .width = sizeof(uint8_t), 261 }, 262 [IEEE80211_RADIOTAP_DBM_ANTNOISE] = { 263 .align = sizeof(uint8_t), 264 .width = sizeof(uint8_t), 265 }, 266 [IEEE80211_RADIOTAP_LOCK_QUALITY] = { 267 .align = sizeof(uint16_t), 268 .width = sizeof(uint16_t), 269 }, 270 [IEEE80211_RADIOTAP_TX_ATTENUATION] = { 271 .align = sizeof(uint16_t), 272 .width = sizeof(uint16_t), 273 }, 274 [IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = { 275 .align = sizeof(uint16_t), 276 .width = sizeof(uint16_t), 277 }, 278 [IEEE80211_RADIOTAP_DBM_TX_POWER] = { 279 .align = sizeof(uint8_t), 280 .width = sizeof(uint8_t), 281 }, 282 [IEEE80211_RADIOTAP_ANTENNA] = { 283 .align = sizeof(uint8_t), 284 .width = sizeof(uint8_t), 285 }, 286 [IEEE80211_RADIOTAP_DB_ANTSIGNAL] = { 287 .align = sizeof(uint8_t), 288 .width = sizeof(uint8_t), 289 }, 290 [IEEE80211_RADIOTAP_DB_ANTNOISE] = { 291 .align = sizeof(uint8_t), 292 .width = sizeof(uint8_t), 293 }, 294 [IEEE80211_RADIOTAP_XCHANNEL] = { 295 .align = sizeof(uint32_t), 296 .width = 2*sizeof(uint32_t), 297 }, 298 }; 299 uint32_t present = le32toh(rh->it_present); 300 int off, i; 301 302 off = sizeof(struct ieee80211_radiotap_header); 303 for (i = 0; i < IEEE80211_RADIOTAP_EXT; i++) { 304 if ((present & (1<<i)) == 0) 305 continue; 306 if (items[i].align == 0) { 307 /* NB: unidentified element, don't guess */ 308 printf("%s: unknown item %d\n", __func__, i); 309 return -1; 310 } 311 off = roundup2(off, items[i].align); 312 if (i == item) { 313 if (off + items[i].width > le16toh(rh->it_len)) { 314 /* NB: item does not fit in header data */ 315 printf("%s: item %d not in header data, " 316 "off %d width %zu len %d\n", __func__, i, 317 off, items[i].width, le16toh(rh->it_len)); 318 return -1; 319 } 320 return off; 321 } 322 off += items[i].width; 323 } 324 return -1; 325 } 326