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| author | Johannes Berg <johannes@sipsolutions.net> | 2009-10-28 11:58:52 +0300 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2009-10-30 23:49:20 +0300 |
| commit | 6a86b9c78ebd0397eb953493c68ea9e194e7023c (patch) | |
| tree | 521d05f66acb338a23e3bf6aac077896ae5ca044 | |
| parent | 4d36ec58239eec44d77839ef6c25108efcbbb58c (diff) | |
| download | linux-6a86b9c78ebd0397eb953493c68ea9e194e7023c.tar.xz | |
mac80211: fix radiotap header generation
In
commit 601ae7f25aea58f208a7f640f6174aac0652403a
Author: Bruno Randolf <br1@einfach.org>
Date: Thu May 8 19:22:43 2008 +0200
mac80211: make rx radiotap header more flexible
code was added that tried to align the radiotap header
position in memory based on the radiotap header length.
Quite obviously, that is completely useless.
Instead of trying to do that, use unaligned accesses
to generate the radiotap header. To properly do that,
we also need to mark struct ieee80211_radiotap_header
packed, but that is fine since it's already packed
(and it should be marked packed anyway since its a
wire format).
Cc: Bruno Randolf <br1@einfach.org>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
| -rw-r--r-- | include/net/ieee80211_radiotap.h | 2 | ||||
| -rw-r--r-- | net/mac80211/rx.c | 26 |
2 files changed, 13 insertions, 15 deletions
diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h index 23c3f3d97779..9d3d86aaccbb 100644 --- a/include/net/ieee80211_radiotap.h +++ b/include/net/ieee80211_radiotap.h @@ -80,7 +80,7 @@ struct ieee80211_radiotap_header { * Additional extensions are made * by setting bit 31. */ -}; +} __packed; /* Name Data type Units * ---- --------- ----- diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index 5c385e3c1d1f..01df328530ad 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -95,10 +95,6 @@ ieee80211_rx_radiotap_len(struct ieee80211_local *local, if (len & 1) /* padding for RX_FLAGS if necessary */ len++; - /* make sure radiotap starts at a naturally aligned address */ - if (len % 8) - len = roundup(len, 8); - return len; } @@ -116,6 +112,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local, struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); struct ieee80211_radiotap_header *rthdr; unsigned char *pos; + u16 rx_flags = 0; rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len); memset(rthdr, 0, rtap_len); @@ -134,7 +131,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local, /* IEEE80211_RADIOTAP_TSFT */ if (status->flag & RX_FLAG_TSFT) { - *(__le64 *)pos = cpu_to_le64(status->mactime); + put_unaligned_le64(status->mactime, pos); rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT); pos += 8; @@ -166,17 +163,17 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local, pos++; /* IEEE80211_RADIOTAP_CHANNEL */ - *(__le16 *)pos = cpu_to_le16(status->freq); + put_unaligned_le16(status->freq, pos); pos += 2; if (status->band == IEEE80211_BAND_5GHZ) - *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM | - IEEE80211_CHAN_5GHZ); + put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ, + pos); else if (rate->flags & IEEE80211_RATE_ERP_G) - *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM | - IEEE80211_CHAN_2GHZ); + put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ, + pos); else - *(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_CCK | - IEEE80211_CHAN_2GHZ); + put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ, + pos); pos += 2; /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */ @@ -205,10 +202,11 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local, /* IEEE80211_RADIOTAP_RX_FLAGS */ /* ensure 2 byte alignment for the 2 byte field as required */ - if ((pos - (unsigned char *)rthdr) & 1) + if ((pos - (u8 *)rthdr) & 1) pos++; if (status->flag & RX_FLAG_FAILED_PLCP_CRC) - *(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADPLCP); + rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP; + put_unaligned_le16(rx_flags, pos); pos += 2; } |