From: Johannes Berg <johannes@sipsolutions.net>
To: Michael Wu <flamingice@sourmilk.net>,
John Linville <linville@tuxdriver.com>
Cc: linux-wireless@vger.kernel.org, Andy Green <andy@warmcat.com>
Subject: [patch 5/7] mac80211: improve radiotap injection
Date: Wed, 26 Sep 2007 17:53:18 +0200 [thread overview]
Message-ID: <20070926155434.915293000@sipsolutions.net> (raw)
In-Reply-To: 20070926155313.955049000@sipsolutions.net
This improves radiotap injection by removing the shortcut over TX handlers
that led to BUGS when injecting frames without setting a rate and also
resulted in various other quirks. Now, TX handlers are run but some
information that was present in the radiotap header is used instead of
automatic settings.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Andy Green <andy@warmcat.com>
---
Documentation/networking/mac80211-injection.txt | 32 +++
net/mac80211/ieee80211_i.h | 1
net/mac80211/tx.c | 195 ++++++++++++------------
3 files changed, 131 insertions(+), 97 deletions(-)
--- wireless-dev.orig/net/mac80211/tx.c 2007-09-26 17:45:46.507337342 +0200
+++ wireless-dev/net/mac80211/tx.c 2007-09-26 17:51:21.617337342 +0200
@@ -222,6 +222,9 @@ ieee80211_tx_h_check_assoc(struct ieee80
#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
u32 sta_flags;
+ if (unlikely(tx->flags & IEEE80211_TXRXD_TX_INJECTED))
+ return TXRX_CONTINUE;
+
if (unlikely(tx->local->sta_scanning != 0) &&
((tx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_MGMT ||
(tx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PROBE_REQ))
@@ -566,22 +569,27 @@ ieee80211_tx_h_rate_ctrl(struct ieee8021
{
struct rate_control_extra extra;
- memset(&extra, 0, sizeof(extra));
- extra.mode = tx->u.tx.mode;
- extra.ethertype = tx->ethertype;
-
- tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev, tx->skb,
- &extra);
- if (unlikely(extra.probe != NULL)) {
- tx->u.tx.control->flags |= IEEE80211_TXCTL_RATE_CTRL_PROBE;
- tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
- tx->u.tx.control->alt_retry_rate = tx->u.tx.rate->val;
- tx->u.tx.rate = extra.probe;
- } else {
+ if (likely(!tx->u.tx.rate)) {
+ memset(&extra, 0, sizeof(extra));
+ extra.mode = tx->u.tx.mode;
+ extra.ethertype = tx->ethertype;
+
+ tx->u.tx.rate = rate_control_get_rate(tx->local, tx->dev,
+ tx->skb, &extra);
+ if (unlikely(extra.probe != NULL)) {
+ tx->u.tx.control->flags |=
+ IEEE80211_TXCTL_RATE_CTRL_PROBE;
+ tx->flags |= IEEE80211_TXRXD_TXPROBE_LAST_FRAG;
+ tx->u.tx.control->alt_retry_rate = tx->u.tx.rate->val;
+ tx->u.tx.rate = extra.probe;
+ } else
+ tx->u.tx.control->alt_retry_rate = -1;
+
+ if (!tx->u.tx.rate)
+ return TXRX_DROP;
+ } else
tx->u.tx.control->alt_retry_rate = -1;
- }
- if (!tx->u.tx.rate)
- return TXRX_DROP;
+
if (tx->u.tx.mode->mode == MODE_IEEE80211G &&
(tx->sdata->flags & IEEE80211_SDATA_USE_PROTECTION) &&
(tx->flags & IEEE80211_TXRXD_FRAGMENTED) && extra.nonerp) {
@@ -611,19 +619,24 @@ ieee80211_tx_h_misc(struct ieee80211_txr
struct ieee80211_tx_control *control = tx->u.tx.control;
struct ieee80211_hw_mode *mode = tx->u.tx.mode;
- if (!is_multicast_ether_addr(hdr->addr1)) {
- if (tx->skb->len + FCS_LEN > tx->local->rts_threshold &&
- tx->local->rts_threshold < IEEE80211_MAX_RTS_THRESHOLD) {
- control->flags |= IEEE80211_TXCTL_USE_RTS_CTS;
- control->flags |= IEEE80211_TXCTL_LONG_RETRY_LIMIT;
- control->retry_limit =
- tx->local->long_retry_limit;
+ if (!control->retry_limit) {
+ if (!is_multicast_ether_addr(hdr->addr1)) {
+ if (tx->skb->len + FCS_LEN > tx->local->rts_threshold
+ && tx->local->rts_threshold <
+ IEEE80211_MAX_RTS_THRESHOLD) {
+ control->flags |=
+ IEEE80211_TXCTL_USE_RTS_CTS;
+ control->flags |=
+ IEEE80211_TXCTL_LONG_RETRY_LIMIT;
+ control->retry_limit =
+ tx->local->long_retry_limit;
+ } else {
+ control->retry_limit =
+ tx->local->short_retry_limit;
+ }
} else {
- control->retry_limit =
- tx->local->short_retry_limit;
+ control->retry_limit = 1;
}
- } else {
- control->retry_limit = 1;
}
if (tx->flags & IEEE80211_TXRXD_FRAGMENTED) {
@@ -785,9 +798,8 @@ ieee80211_tx_handler ieee80211_tx_handle
* with Radiotap Header -- only called for monitor mode interface
*/
static ieee80211_txrx_result
-__ieee80211_parse_tx_radiotap(
- struct ieee80211_txrx_data *tx,
- struct sk_buff *skb, struct ieee80211_tx_control *control)
+__ieee80211_parse_tx_radiotap(struct ieee80211_txrx_data *tx,
+ struct sk_buff *skb)
{
/*
* this is the moment to interpret and discard the radiotap header that
@@ -802,18 +814,11 @@ __ieee80211_parse_tx_radiotap(
(struct ieee80211_radiotap_header *) skb->data;
struct ieee80211_hw_mode *mode = tx->local->hw.conf.mode;
int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
+ struct ieee80211_tx_control *control = tx->u.tx.control;
- /*
- * default control situation for all injected packets
- * FIXME: this does not suit all usage cases, expand to allow control
- */
-
- control->retry_limit = 1; /* no retry */
- control->flags &= ~(IEEE80211_TXCTL_USE_RTS_CTS |
- IEEE80211_TXCTL_USE_CTS_PROTECT);
- control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT |
- IEEE80211_TXCTL_NO_ACK;
- control->antenna_sel_tx = 0; /* default to default antenna */
+ control->flags |= IEEE80211_TXCTL_DO_NOT_ENCRYPT;
+ tx->flags |= IEEE80211_TXRXD_TX_INJECTED;
+ tx->flags &= ~IEEE80211_TXRXD_FRAGMENTED;
/*
* for every radiotap entry that is present
@@ -846,19 +851,10 @@ __ieee80211_parse_tx_radiotap(
for (i = 0; i < mode->num_rates; i++) {
struct ieee80211_rate *r = &mode->rates[i];
- if (r->rate > target_rate)
- continue;
-
- control->rate = r;
-
- if (r->flags & IEEE80211_RATE_PREAMBLE2)
- control->tx_rate = r->val2;
- else
- control->tx_rate = r->val;
-
- /* end on exact match */
- if (r->rate == target_rate)
- i = mode->num_rates;
+ if (r->rate == target_rate) {
+ tx->u.tx.rate = r;
+ break;
+ }
}
break;
@@ -888,8 +884,19 @@ __ieee80211_parse_tx_radiotap(
skb_trim(skb, skb->len - FCS_LEN);
}
+ if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
+ control->flags &=
+ ~IEEE80211_TXCTL_DO_NOT_ENCRYPT;
+ if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
+ tx->flags |= IEEE80211_TXRXD_FRAGMENTED;
break;
+ /*
+ * Please update the file
+ * Documentation/networking/mac80211-injection.txt
+ * when parsing new fields here.
+ */
+
default:
break;
}
@@ -908,14 +915,17 @@ __ieee80211_parse_tx_radiotap(
return TXRX_CONTINUE;
}
-static ieee80211_txrx_result inline
+/*
+ * initialises @tx
+ */
+static ieee80211_txrx_result
__ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
struct sk_buff *skb,
struct net_device *dev,
struct ieee80211_tx_control *control)
{
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
- struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct ieee80211_hdr *hdr;
struct ieee80211_sub_if_data *sdata;
ieee80211_txrx_result res = TXRX_CONTINUE;
@@ -926,33 +936,31 @@ __ieee80211_tx_prepare(struct ieee80211_
tx->dev = dev; /* use original interface */
tx->local = local;
tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
-
+ tx->u.tx.control = control;
/*
- * set defaults for things that can be set by
- * injected radiotap headers
+ * Set this flag (used below to indicate "automatic fragmentation"),
+ * it will be cleared/left by radiotap as desired.
*/
- control->power_level = local->hw.conf.power_level;
- control->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
+ tx->flags |= IEEE80211_TXRXD_FRAGMENTED;
/* process and remove the injection radiotap header */
sdata = IEEE80211_DEV_TO_SUB_IF(dev);
if (unlikely(sdata->type == IEEE80211_IF_TYPE_MNTR)) {
- if (__ieee80211_parse_tx_radiotap(tx, skb, control) ==
- TXRX_DROP) {
+ if (__ieee80211_parse_tx_radiotap(tx, skb) == TXRX_DROP)
return TXRX_DROP;
- }
+
/*
- * we removed the radiotap header after this point,
- * we filled control with what we could use
- * set to the actual ieee header now
+ * __ieee80211_parse_tx_radiotap has now removed
+ * the radiotap header that was present and pre-filled
+ * 'tx' with tx control information.
*/
- hdr = (struct ieee80211_hdr *) skb->data;
- res = TXRX_QUEUED; /* indication it was monitor packet */
}
+ hdr = (struct ieee80211_hdr *) skb->data;
+
tx->sta = sta_info_get(local, hdr->addr1);
tx->fc = le16_to_cpu(hdr->frame_control);
- tx->u.tx.control = control;
+
if (is_multicast_ether_addr(hdr->addr1)) {
tx->flags &= ~IEEE80211_TXRXD_TXUNICAST;
control->flags |= IEEE80211_TXCTL_NO_ACK;
@@ -960,19 +968,23 @@ __ieee80211_tx_prepare(struct ieee80211_
tx->flags |= IEEE80211_TXRXD_TXUNICAST;
control->flags &= ~IEEE80211_TXCTL_NO_ACK;
}
- if (local->fragmentation_threshold < IEEE80211_MAX_FRAG_THRESHOLD &&
- (tx->flags & IEEE80211_TXRXD_TXUNICAST) &&
- skb->len + FCS_LEN > local->fragmentation_threshold &&
- !local->ops->set_frag_threshold)
- tx->flags |= IEEE80211_TXRXD_FRAGMENTED;
- else
- tx->flags &= ~IEEE80211_TXRXD_FRAGMENTED;
+
+ if (tx->flags & IEEE80211_TXRXD_FRAGMENTED) {
+ if ((tx->flags & IEEE80211_TXRXD_TXUNICAST) &&
+ skb->len + FCS_LEN > local->fragmentation_threshold &&
+ !local->ops->set_frag_threshold)
+ tx->flags |= IEEE80211_TXRXD_FRAGMENTED;
+ else
+ tx->flags &= ~IEEE80211_TXRXD_FRAGMENTED;
+ }
+
if (!tx->sta)
control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
else if (tx->sta->clear_dst_mask) {
control->flags |= IEEE80211_TXCTL_CLEAR_DST_MASK;
tx->sta->clear_dst_mask = 0;
}
+
hdrlen = ieee80211_get_hdrlen(tx->fc);
if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
@@ -984,11 +996,14 @@ __ieee80211_tx_prepare(struct ieee80211_
}
/* Device in tx->dev has a reference added; use dev_put(tx->dev) when
- * finished with it. */
-static int inline ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
- struct sk_buff *skb,
- struct net_device *mdev,
- struct ieee80211_tx_control *control)
+ * finished with it.
+ *
+ * NB: @tx is uninitialised when passed in here
+ */
+static int ieee80211_tx_prepare(struct ieee80211_txrx_data *tx,
+ struct sk_buff *skb,
+ struct net_device *mdev,
+ struct ieee80211_tx_control *control)
{
struct ieee80211_tx_packet_data *pkt_data;
struct net_device *dev;
@@ -1001,6 +1016,7 @@ static int inline ieee80211_tx_prepare(s
}
if (unlikely(!dev))
return -ENODEV;
+ /* initialises tx with control */
__ieee80211_tx_prepare(tx, skb, dev, control);
return 0;
}
@@ -1081,6 +1097,7 @@ static int ieee80211_tx(struct net_devic
return 0;
}
+ /* initialises tx */
res_prepare = __ieee80211_tx_prepare(&tx, skb, dev, control);
if (res_prepare == TXRX_DROP) {
@@ -1097,15 +1114,11 @@ static int ieee80211_tx(struct net_devic
sta = tx.sta;
tx.u.tx.mode = local->hw.conf.mode;
- if (res_prepare == TXRX_QUEUED) { /* if it was an injected packet */
- res = TXRX_CONTINUE;
- } else {
- for (handler = local->tx_handlers; *handler != NULL;
- handler++) {
- res = (*handler)(&tx);
- if (res != TXRX_CONTINUE)
- break;
- }
+ for (handler = local->tx_handlers; *handler != NULL;
+ handler++) {
+ res = (*handler)(&tx);
+ if (res != TXRX_CONTINUE)
+ break;
}
skb = tx.skb; /* handlers are allowed to change skb */
@@ -1857,7 +1870,7 @@ ieee80211_get_buffered_bc(struct ieee802
cpu_to_le16(IEEE80211_FCTL_MOREDATA);
}
- if (ieee80211_tx_prepare(&tx, skb, local->mdev, control) == 0)
+ if (!ieee80211_tx_prepare(&tx, skb, local->mdev, control))
break;
dev_kfree_skb_any(skb);
}
--- wireless-dev.orig/Documentation/networking/mac80211-injection.txt 2007-09-26 17:38:20.637337342 +0200
+++ wireless-dev/Documentation/networking/mac80211-injection.txt 2007-09-26 17:51:21.617337342 +0200
@@ -13,15 +13,35 @@ The radiotap format is discussed in
./Documentation/networking/radiotap-headers.txt.
Despite 13 radiotap argument types are currently defined, most only make sense
-to appear on received packets. Currently three kinds of argument are used by
-the injection code, although it knows to skip any other arguments that are
-present (facilitating replay of captured radiotap headers directly):
+to appear on received packets. The following information is parsed from the
+radiotap headers and used to control injection:
- - IEEE80211_RADIOTAP_RATE - u8 arg in 500kbps units (0x02 --> 1Mbps)
+ * IEEE80211_RADIOTAP_RATE
- - IEEE80211_RADIOTAP_ANTENNA - u8 arg, 0x00 = ant1, 0x01 = ant2
+ rate in 500kbps units, automatic if invalid or not present
- - IEEE80211_RADIOTAP_DBM_TX_POWER - u8 arg, dBm
+
+ * IEEE80211_RADIOTAP_ANTENNA
+
+ antenna to use, automatic if not present
+
+
+ * IEEE80211_RADIOTAP_DBM_TX_POWER
+
+ transmit power in dBm, automatic if not present
+
+
+ * IEEE80211_RADIOTAP_FLAGS
+
+ IEEE80211_RADIOTAP_F_FCS: FCS will be removed and recalculated
+ IEEE80211_RADIOTAP_F_WEP: frame will be encrypted if key available
+ IEEE80211_RADIOTAP_F_FRAG: frame will be fragmented if longer than the
+ current fragmentation threshold. Note that
+ this flag is only reliable when software
+ fragmentation is enabled)
+
+The injection code can also skip all other currently defined radiotap fields
+facilitating replay of captured radiotap headers directly.
Here is an example valid radiotap header defining these three parameters
--- wireless-dev.orig/net/mac80211/ieee80211_i.h 2007-09-26 17:38:20.567337342 +0200
+++ wireless-dev/net/mac80211/ieee80211_i.h 2007-09-26 17:51:21.617337342 +0200
@@ -122,6 +122,7 @@ typedef enum {
#define IEEE80211_TXRXD_RXIN_SCAN BIT(4)
/* frame is destined to interface currently processed (incl. multicast frames) */
#define IEEE80211_TXRXD_RXRA_MATCH BIT(5)
+#define IEEE80211_TXRXD_TX_INJECTED BIT(6)
struct ieee80211_txrx_data {
struct sk_buff *skb;
struct net_device *dev;
--
next prev parent reply other threads:[~2007-09-26 15:54 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-26 15:53 [patch 0/7] more mac80211 cleanups and fixes Johannes Berg
2007-09-26 15:53 ` [patch 1/7] mac80211: move sta_process rx handler later Johannes Berg
2007-09-26 15:53 ` [patch 2/7] mac80211: consolidate decryption more Johannes Berg
2007-09-26 15:53 ` [patch 3/7] mac80211: use RX_FLAG_DECRYPTED for sw decrypted as well Johannes Berg
2007-09-26 15:53 ` [patch 4/7] mac80211: remove ALG_NONE Johannes Berg
2007-09-27 1:03 ` Zhu Yi
2007-09-26 15:53 ` Johannes Berg [this message]
2007-09-26 15:53 ` [patch 6/7] mac80211: allow only one IBSS interface Johannes Berg
2007-09-26 15:53 ` [patch 7/7] mac80211: make userspace-mlme a per-interface setting Johannes Berg
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20070926155434.915293000@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=andy@warmcat.com \
--cc=flamingice@sourmilk.net \
--cc=linux-wireless@vger.kernel.org \
--cc=linville@tuxdriver.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.