mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-29 07:04:10 +08:00
mac80211: parse radiotap header earlier
We can now move the radiotap header parsing into ieee80211_monitor_start_xmit(). This moves it out of the hotpath, and also helps the code since now the radiotap header will no longer be present in ieee80211_xmit() etc. which is easier to understand. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg
John W. Linville
parent
a26eb27ab4
commit
73b9f03a81
@ -349,8 +349,6 @@ struct ieee80211_bss_conf {
|
||||
* @IEEE80211_TX_INTFL_RETRANSMISSION: This frame is being retransmitted
|
||||
* after TX status because the destination was asleep, it must not
|
||||
* be modified again (no seqno assignment, crypto, etc.)
|
||||
* @IEEE80211_TX_INTFL_HAS_RADIOTAP: This frame was injected and still
|
||||
* has a radiotap header at skb->data.
|
||||
* @IEEE80211_TX_INTFL_NL80211_FRAME_TX: Frame was requested through nl80211
|
||||
* MLME command (internal to mac80211 to figure out whether to send TX
|
||||
* status to user space)
|
||||
@ -402,7 +400,7 @@ enum mac80211_tx_control_flags {
|
||||
IEEE80211_TX_CTL_POLL_RESPONSE = BIT(17),
|
||||
IEEE80211_TX_CTL_MORE_FRAMES = BIT(18),
|
||||
IEEE80211_TX_INTFL_RETRANSMISSION = BIT(19),
|
||||
IEEE80211_TX_INTFL_HAS_RADIOTAP = BIT(20),
|
||||
/* hole at 20, use later */
|
||||
IEEE80211_TX_INTFL_NL80211_FRAME_TX = BIT(21),
|
||||
IEEE80211_TX_CTL_LDPC = BIT(22),
|
||||
IEEE80211_TX_CTL_STBC = BIT(23) | BIT(24),
|
||||
|
||||
@ -1035,103 +1035,6 @@ ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
|
||||
|
||||
/* actual transmit path */
|
||||
|
||||
/*
|
||||
* deal with packet injection down monitor interface
|
||||
* with Radiotap Header -- only called for monitor mode interface
|
||||
*/
|
||||
static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
|
||||
struct sk_buff *skb)
|
||||
{
|
||||
/*
|
||||
* this is the moment to interpret and discard the radiotap header that
|
||||
* must be at the start of the packet injected in Monitor mode
|
||||
*
|
||||
* Need to take some care with endian-ness since radiotap
|
||||
* args are little-endian
|
||||
*/
|
||||
|
||||
struct ieee80211_radiotap_iterator iterator;
|
||||
struct ieee80211_radiotap_header *rthdr =
|
||||
(struct ieee80211_radiotap_header *) skb->data;
|
||||
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
|
||||
int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
|
||||
NULL);
|
||||
u16 txflags;
|
||||
|
||||
info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
|
||||
IEEE80211_TX_CTL_DONTFRAG;
|
||||
|
||||
/*
|
||||
* for every radiotap entry that is present
|
||||
* (ieee80211_radiotap_iterator_next returns -ENOENT when no more
|
||||
* entries present, or -EINVAL on error)
|
||||
*/
|
||||
|
||||
while (!ret) {
|
||||
ret = ieee80211_radiotap_iterator_next(&iterator);
|
||||
|
||||
if (ret)
|
||||
continue;
|
||||
|
||||
/* see if this argument is something we can use */
|
||||
switch (iterator.this_arg_index) {
|
||||
/*
|
||||
* You must take care when dereferencing iterator.this_arg
|
||||
* for multibyte types... the pointer is not aligned. Use
|
||||
* get_unaligned((type *)iterator.this_arg) to dereference
|
||||
* iterator.this_arg for type "type" safely on all arches.
|
||||
*/
|
||||
case IEEE80211_RADIOTAP_FLAGS:
|
||||
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
|
||||
/*
|
||||
* this indicates that the skb we have been
|
||||
* handed has the 32-bit FCS CRC at the end...
|
||||
* we should react to that by snipping it off
|
||||
* because it will be recomputed and added
|
||||
* on transmission
|
||||
*/
|
||||
if (skb->len < (iterator._max_length + FCS_LEN))
|
||||
return false;
|
||||
|
||||
skb_trim(skb, skb->len - FCS_LEN);
|
||||
}
|
||||
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
|
||||
info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
|
||||
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
|
||||
info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
|
||||
break;
|
||||
|
||||
case IEEE80211_RADIOTAP_TX_FLAGS:
|
||||
txflags = le16_to_cpu(get_unaligned((__le16*)
|
||||
iterator.this_arg));
|
||||
if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
|
||||
info->flags |= IEEE80211_TX_CTL_NO_ACK;
|
||||
break;
|
||||
|
||||
/*
|
||||
* Please update the file
|
||||
* Documentation/networking/mac80211-injection.txt
|
||||
* when parsing new fields here.
|
||||
*/
|
||||
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
|
||||
return false;
|
||||
|
||||
/*
|
||||
* remove the radiotap header
|
||||
* iterator->_max_length was sanity-checked against
|
||||
* skb->len by iterator init
|
||||
*/
|
||||
skb_pull(skb, iterator._max_length);
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool ieee80211_tx_prep_agg(struct ieee80211_tx_data *tx,
|
||||
struct sk_buff *skb,
|
||||
struct ieee80211_tx_info *info,
|
||||
@ -1205,19 +1108,6 @@ ieee80211_tx_prepare(struct ieee80211_sub_if_data *sdata,
|
||||
tx->sdata = sdata;
|
||||
tx->channel = local->hw.conf.channel;
|
||||
|
||||
/* process and remove the injection radiotap header */
|
||||
if (unlikely(info->flags & IEEE80211_TX_INTFL_HAS_RADIOTAP)) {
|
||||
if (!__ieee80211_parse_tx_radiotap(tx, skb))
|
||||
return TX_DROP;
|
||||
|
||||
/*
|
||||
* __ieee80211_parse_tx_radiotap has now removed
|
||||
* the radiotap header that was present and pre-filled
|
||||
* 'tx' with tx control information.
|
||||
*/
|
||||
info->flags &= ~IEEE80211_TX_INTFL_HAS_RADIOTAP;
|
||||
}
|
||||
|
||||
/*
|
||||
* If this flag is set to true anywhere, and we get here,
|
||||
* we are doing the needed processing, so remove the flag
|
||||
@ -1559,6 +1449,89 @@ void ieee80211_xmit(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb)
|
||||
rcu_read_unlock();
|
||||
}
|
||||
|
||||
static bool ieee80211_parse_tx_radiotap(struct sk_buff *skb)
|
||||
{
|
||||
struct ieee80211_radiotap_iterator iterator;
|
||||
struct ieee80211_radiotap_header *rthdr =
|
||||
(struct ieee80211_radiotap_header *) skb->data;
|
||||
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
|
||||
int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
|
||||
NULL);
|
||||
u16 txflags;
|
||||
|
||||
info->flags |= IEEE80211_TX_INTFL_DONT_ENCRYPT |
|
||||
IEEE80211_TX_CTL_DONTFRAG;
|
||||
|
||||
/*
|
||||
* for every radiotap entry that is present
|
||||
* (ieee80211_radiotap_iterator_next returns -ENOENT when no more
|
||||
* entries present, or -EINVAL on error)
|
||||
*/
|
||||
|
||||
while (!ret) {
|
||||
ret = ieee80211_radiotap_iterator_next(&iterator);
|
||||
|
||||
if (ret)
|
||||
continue;
|
||||
|
||||
/* see if this argument is something we can use */
|
||||
switch (iterator.this_arg_index) {
|
||||
/*
|
||||
* You must take care when dereferencing iterator.this_arg
|
||||
* for multibyte types... the pointer is not aligned. Use
|
||||
* get_unaligned((type *)iterator.this_arg) to dereference
|
||||
* iterator.this_arg for type "type" safely on all arches.
|
||||
*/
|
||||
case IEEE80211_RADIOTAP_FLAGS:
|
||||
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
|
||||
/*
|
||||
* this indicates that the skb we have been
|
||||
* handed has the 32-bit FCS CRC at the end...
|
||||
* we should react to that by snipping it off
|
||||
* because it will be recomputed and added
|
||||
* on transmission
|
||||
*/
|
||||
if (skb->len < (iterator._max_length + FCS_LEN))
|
||||
return false;
|
||||
|
||||
skb_trim(skb, skb->len - FCS_LEN);
|
||||
}
|
||||
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
|
||||
info->flags &= ~IEEE80211_TX_INTFL_DONT_ENCRYPT;
|
||||
if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
|
||||
info->flags &= ~IEEE80211_TX_CTL_DONTFRAG;
|
||||
break;
|
||||
|
||||
case IEEE80211_RADIOTAP_TX_FLAGS:
|
||||
txflags = get_unaligned_le16(iterator.this_arg);
|
||||
if (txflags & IEEE80211_RADIOTAP_F_TX_NOACK)
|
||||
info->flags |= IEEE80211_TX_CTL_NO_ACK;
|
||||
break;
|
||||
|
||||
/*
|
||||
* Please update the file
|
||||
* Documentation/networking/mac80211-injection.txt
|
||||
* when parsing new fields here.
|
||||
*/
|
||||
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
|
||||
return false;
|
||||
|
||||
/*
|
||||
* remove the radiotap header
|
||||
* iterator->_max_length was sanity-checked against
|
||||
* skb->len by iterator init
|
||||
*/
|
||||
skb_pull(skb, iterator._max_length);
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
|
||||
struct net_device *dev)
|
||||
{
|
||||
@ -1646,8 +1619,11 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
|
||||
memset(info, 0, sizeof(*info));
|
||||
|
||||
info->flags = IEEE80211_TX_CTL_REQ_TX_STATUS |
|
||||
IEEE80211_TX_CTL_INJECTED |
|
||||
IEEE80211_TX_INTFL_HAS_RADIOTAP;
|
||||
IEEE80211_TX_CTL_INJECTED;
|
||||
|
||||
/* process and remove the injection radiotap header */
|
||||
if (!ieee80211_parse_tx_radiotap(skb))
|
||||
goto fail;
|
||||
|
||||
rcu_read_lock();
|
||||
|
||||
@ -1674,7 +1650,6 @@ netdev_tx_t ieee80211_monitor_start_xmit(struct sk_buff *skb,
|
||||
}
|
||||
}
|
||||
|
||||
/* pass the radiotap header up to xmit */
|
||||
ieee80211_xmit(sdata, skb);
|
||||
rcu_read_unlock();
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user