| Current Path : /sys/net80211/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/net80211/ieee80211_radiotap.c |
/*-
* Copyright (c) 2009 Sam Leffler, Errno Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/net80211/ieee80211_radiotap.c 193761 2009-06-08 21:16:06Z sam $");
/*
* IEEE 802.11 radiotap support.
*/
#include "opt_wlan.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <net/bpf.h>
#include <net/if.h>
#include <net/if_llc.h>
#include <net/if_media.h>
#include <net80211/ieee80211_var.h>
static int radiotap_offset(struct ieee80211_radiotap_header *, int);
void
ieee80211_radiotap_attach(struct ieee80211com *ic,
struct ieee80211_radiotap_header *th, int tlen, uint32_t tx_radiotap,
struct ieee80211_radiotap_header *rh, int rlen, uint32_t rx_radiotap)
{
#define B(_v) (1<<(_v))
int off;
th->it_len = htole16(roundup2(tlen, sizeof(uint32_t)));
th->it_present = htole32(tx_radiotap);
ic->ic_th = th;
/* calculate offset to channel data */
off = -1;
if (tx_radiotap & B(IEEE80211_RADIOTAP_CHANNEL))
off = radiotap_offset(th, IEEE80211_RADIOTAP_CHANNEL);
else if (tx_radiotap & B(IEEE80211_RADIOTAP_XCHANNEL))
off = radiotap_offset(th, IEEE80211_RADIOTAP_XCHANNEL);
if (off == -1) {
if_printf(ic->ic_ifp, "%s: no tx channel, radiotap 0x%x",
__func__, tx_radiotap);
/* NB: we handle this case but data will have no chan spec */
} else
ic->ic_txchan = ((uint8_t *) th) + off;
rh->it_len = htole16(roundup2(rlen, sizeof(uint32_t)));
rh->it_present = htole32(rx_radiotap);
ic->ic_rh = rh;
/* calculate offset to channel data */
off = -1;
if (rx_radiotap & B(IEEE80211_RADIOTAP_CHANNEL))
off = radiotap_offset(rh, IEEE80211_RADIOTAP_CHANNEL);
else if (rx_radiotap & B(IEEE80211_RADIOTAP_XCHANNEL))
off = radiotap_offset(rh, IEEE80211_RADIOTAP_XCHANNEL);
if (off == -1) {
if_printf(ic->ic_ifp, "%s: no rx channel, radiotap 0x%x",
__func__, rx_radiotap);
/* NB: we handle this case but data will have no chan spec */
} else
ic->ic_rxchan = ((uint8_t *) rh) + off;
#undef B
}
void
ieee80211_radiotap_detach(struct ieee80211com *ic)
{
}
void
ieee80211_radiotap_vattach(struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
struct ieee80211_radiotap_header *th = ic->ic_th;
if (th != NULL && ic->ic_rh != NULL) {
/* radiotap DLT for raw 802.11 frames */
bpfattach2(vap->iv_ifp, DLT_IEEE802_11_RADIO,
sizeof(struct ieee80211_frame) + le16toh(th->it_len),
&vap->iv_rawbpf);
}
}
void
ieee80211_radiotap_vdetach(struct ieee80211vap *vap)
{
/* NB: bpfattach is called by ether_ifdetach and claims all taps */
}
static void
set_channel(void *p, const struct ieee80211_channel *c)
{
struct {
uint16_t freq;
uint16_t flags;
} *rc = p;
rc->freq = htole16(c->ic_freq);
rc->flags = htole16(c->ic_flags);
}
static void
set_xchannel(void *p, const struct ieee80211_channel *c)
{
struct {
uint32_t flags;
uint16_t freq;
uint8_t ieee;
uint8_t maxpow;
} *rc = p;
rc->flags = htole32(c->ic_flags);
rc->freq = htole16(c->ic_freq);
rc->ieee = c->ic_ieee;
rc->maxpow = c->ic_maxregpower;
}
/*
* Update radiotap state on channel change.
*/
void
ieee80211_radiotap_chan_change(struct ieee80211com *ic)
{
if (ic->ic_rxchan != NULL) {
struct ieee80211_radiotap_header *rh = ic->ic_rh;
if (rh->it_present & htole32(1<<IEEE80211_RADIOTAP_XCHANNEL))
set_xchannel(ic->ic_rxchan, ic->ic_curchan);
else if (rh->it_present & htole32(1<<IEEE80211_RADIOTAP_CHANNEL))
set_channel(ic->ic_rxchan, ic->ic_curchan);
}
if (ic->ic_txchan != NULL) {
struct ieee80211_radiotap_header *th = ic->ic_th;
if (th->it_present & htole32(1<<IEEE80211_RADIOTAP_XCHANNEL))
set_xchannel(ic->ic_txchan, ic->ic_curchan);
else if (th->it_present & htole32(1<<IEEE80211_RADIOTAP_CHANNEL))
set_channel(ic->ic_txchan, ic->ic_curchan);
}
}
/*
* Distribute radiotap data (+packet) to all monitor mode
* vaps with an active tap other than vap0.
*/
static void
spam_vaps(struct ieee80211vap *vap0, struct mbuf *m,
struct ieee80211_radiotap_header *rh, int len)
{
struct ieee80211com *ic = vap0->iv_ic;
struct ieee80211vap *vap;
TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
if (vap != vap0 &&
vap->iv_opmode == IEEE80211_M_MONITOR &&
(vap->iv_flags_ext & IEEE80211_FEXT_BPF) &&
vap->iv_state != IEEE80211_S_INIT)
bpf_mtap2(vap->iv_rawbpf, rh, len, m);
}
}
/*
* Dispatch radiotap data for transmitted packet.
*/
void
ieee80211_radiotap_tx(struct ieee80211vap *vap0, struct mbuf *m)
{
struct ieee80211com *ic = vap0->iv_ic;
struct ieee80211_radiotap_header *th = ic->ic_th;
int len;
KASSERT(th != NULL, ("no tx radiotap header"));
len = le16toh(th->it_len);
if (vap0->iv_flags_ext & IEEE80211_FEXT_BPF)
bpf_mtap2(vap0->iv_rawbpf, th, len, m);
/*
* Spam monitor mode vaps.
*/
if (ic->ic_montaps != 0)
spam_vaps(vap0, m, th, len);
}
/*
* Dispatch radiotap data for received packet.
*/
void
ieee80211_radiotap_rx(struct ieee80211vap *vap0, struct mbuf *m)
{
struct ieee80211com *ic = vap0->iv_ic;
struct ieee80211_radiotap_header *rh = ic->ic_rh;
int len;
KASSERT(rh != NULL, ("no rx radiotap header"));
len = le16toh(rh->it_len);
if (vap0->iv_flags_ext & IEEE80211_FEXT_BPF)
bpf_mtap2(vap0->iv_rawbpf, rh, len, m);
/*
* Spam monitor mode vaps with unicast frames. Multicast
* frames are handled by passing through ieee80211_input_all
* which distributes copies to the monitor mode vaps.
*/
if (ic->ic_montaps != 0 && (m->m_flags & M_BCAST) == 0)
spam_vaps(vap0, m, rh, len);
}
/*
* Dispatch radiotap data for a packet received outside the normal
* rx processing path; this is used, for example, to handle frames
* received with errors that would otherwise be dropped.
*/
void
ieee80211_radiotap_rx_all(struct ieee80211com *ic, struct mbuf *m)
{
struct ieee80211_radiotap_header *rh = ic->ic_rh;
int len = le16toh(rh->it_len);
struct ieee80211vap *vap;
/* XXX locking? */
TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
if (ieee80211_radiotap_active_vap(vap) &&
vap->iv_state != IEEE80211_S_INIT)
bpf_mtap2(vap->iv_rawbpf, rh, len, m);
}
}
/*
* Return the offset of the specified item in the radiotap
* header description. If the item is not present or is not
* known -1 is returned.
*/
static int
radiotap_offset(struct ieee80211_radiotap_header *rh, int item)
{
static const struct {
size_t align, width;
} items[] = {
[IEEE80211_RADIOTAP_TSFT] = {
.align = sizeof(uint64_t),
.width = sizeof(uint64_t),
},
[IEEE80211_RADIOTAP_FLAGS] = {
.align = sizeof(uint8_t),
.width = sizeof(uint8_t),
},
[IEEE80211_RADIOTAP_RATE] = {
.align = sizeof(uint8_t),
.width = sizeof(uint8_t),
},
[IEEE80211_RADIOTAP_CHANNEL] = {
.align = sizeof(uint16_t),
.width = 2*sizeof(uint16_t),
},
[IEEE80211_RADIOTAP_FHSS] = {
.align = sizeof(uint16_t),
.width = sizeof(uint16_t),
},
[IEEE80211_RADIOTAP_DBM_ANTSIGNAL] = {
.align = sizeof(uint8_t),
.width = sizeof(uint8_t),
},
[IEEE80211_RADIOTAP_DBM_ANTNOISE] = {
.align = sizeof(uint8_t),
.width = sizeof(uint8_t),
},
[IEEE80211_RADIOTAP_LOCK_QUALITY] = {
.align = sizeof(uint16_t),
.width = sizeof(uint16_t),
},
[IEEE80211_RADIOTAP_TX_ATTENUATION] = {
.align = sizeof(uint16_t),
.width = sizeof(uint16_t),
},
[IEEE80211_RADIOTAP_DB_TX_ATTENUATION] = {
.align = sizeof(uint16_t),
.width = sizeof(uint16_t),
},
[IEEE80211_RADIOTAP_DBM_TX_POWER] = {
.align = sizeof(uint8_t),
.width = sizeof(uint8_t),
},
[IEEE80211_RADIOTAP_ANTENNA] = {
.align = sizeof(uint8_t),
.width = sizeof(uint8_t),
},
[IEEE80211_RADIOTAP_DB_ANTSIGNAL] = {
.align = sizeof(uint8_t),
.width = sizeof(uint8_t),
},
[IEEE80211_RADIOTAP_DB_ANTNOISE] = {
.align = sizeof(uint8_t),
.width = sizeof(uint8_t),
},
[IEEE80211_RADIOTAP_XCHANNEL] = {
.align = sizeof(uint32_t),
.width = 2*sizeof(uint32_t),
},
};
uint32_t present = le32toh(rh->it_present);
int off, i;
off = sizeof(struct ieee80211_radiotap_header);
for (i = 0; i < IEEE80211_RADIOTAP_EXT; i++) {
if ((present & (1<<i)) == 0)
continue;
if (items[i].align == 0) {
/* NB: unidentified element, don't guess */
printf("%s: unknown item %d\n", __func__, i);
return -1;
}
off = roundup2(off, items[i].align);
if (i == item) {
if (off + items[i].width > le16toh(rh->it_len)) {
/* NB: item does not fit in header data */
printf("%s: item %d not in header data, "
"off %d width %zu len %d\n", __func__, i,
off, items[i].width, le16toh(rh->it_len));
return -1;
}
return off;
}
off += items[i].width;
}
return -1;
}