* [RFA] MCS extension
@ 2010-12-18 17:56 Johannes Berg
[not found] ` <1292694998.3653.33.camel-8upI4CBIZJIJvtFkdXX2HixXY32XiHfO@public.gmane.org>
0 siblings, 1 reply; 4+ messages in thread
From: Johannes Berg @ 2010-12-18 17:56 UTC (permalink / raw)
To: Radiotap
[-- Attachment #1: Type: text/plain, Size: 1396 bytes --]
This is a request for adoption of a new version of the MCS extension.
I've split out the aMPDU extension since that seems more natural.
The MCS extension allows giving MCS information about a frame.
The normative text of this proposal follows (minus formatting):
--- begin normative text ---
MCS
Bit number
19
Structure
u8 known, u8 flags, u8 mcs
Required alignment
1
The MCS field indicates the MCS rate index as in IEEE_802.11n-2009.
The "known" field indicates which information is known:
| flag | definition
---------------------
| 0x01 | bandwidth
| 0x02 | MCS index known (in "mcs" part of the field)
| 0x04 | guard interval
| 0x08 | HT format
| 0x10 | FEC type
| 0xe0 | reserved
The "flags" field is any combination of the following:
| flag | definition
-----------------------------
| 0x03 | bandwidth - 0: 20, 1: 40, 2: 20L, 3: 20U
| 0x04 | guard interval - 0: long GI, 1: short GI
| 0x08 | HT format - 0: mixed, 1: greenfield
| 0x10 | FEC type - 0: BCC, 1: LDPC
| 0xe0 | reserved
--- end normative text ---
I've implemented this in mac80211 (the Linux 802.11 stack) and in
wireshark, both patches are attached.
Due to holidays, I suggest the following timeline:
* comment period until Jan. 15th
* tentatively adopt Jan. 22nd
* fully adopt end of January
I'm also preparing a separate aMPDU field -- see
http://www.radiotap.org/suggested-fields/aMPDU%20status
johannes
[-- Attachment #2: 014-mac80211-ht-rtap.patch --]
[-- Type: text/x-patch, Size: 2965 bytes --]
mac80211: add radiotap MCS information
From: Johannes Berg <johannes.berg-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
This adds the MCS information we currently get
from the drivers into radiotap.
Signed-off-by: Johannes Berg <johannes.berg-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
include/net/ieee80211_radiotap.h | 20 ++++++++++++++++++++
net/mac80211/rx.c | 17 +++++++++++++++++
2 files changed, 37 insertions(+)
--- wireless-testing.orig/net/mac80211/rx.c 2010-12-17 19:34:51.000000000 +0100
+++ wireless-testing/net/mac80211/rx.c 2010-12-18 18:46:22.000000000 +0100
@@ -85,6 +85,9 @@ ieee80211_rx_radiotap_len(struct ieee802
if (len & 1) /* padding for RX_FLAGS if necessary */
len++;
+ if (status->flag & RX_FLAG_HT) /* HT info */
+ len += 3;
+
return len;
}
@@ -193,6 +196,20 @@ ieee80211_add_rx_radiotap_header(struct
rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
put_unaligned_le16(rx_flags, pos);
pos += 2;
+
+ if (status->flag & RX_FLAG_HT) {
+ rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
+ *pos++ = IEEE80211_RADIOTAP_MCS_HAVE_MCS |
+ IEEE80211_RADIOTAP_MCS_HAVE_GI |
+ IEEE80211_RADIOTAP_MCS_HAVE_BW;
+ *pos = 0;
+ if (status->flag & RX_FLAG_SHORT_GI)
+ *pos |= IEEE80211_RADIOTAP_MCS_SGI;
+ if (status->flag & RX_FLAG_40MHZ)
+ *pos |= IEEE80211_RADIOTAP_MCS_BW_40;
+ pos++;
+ *pos++ = status->rate_idx;
+ }
}
/*
--- wireless-testing.orig/include/net/ieee80211_radiotap.h 2010-10-27 07:42:08.000000000 +0200
+++ wireless-testing/include/net/ieee80211_radiotap.h 2010-12-18 18:39:14.000000000 +0100
@@ -199,6 +199,8 @@ enum ieee80211_radiotap_type {
IEEE80211_RADIOTAP_RTS_RETRIES = 16,
IEEE80211_RADIOTAP_DATA_RETRIES = 17,
+ IEEE80211_RADIOTAP_MCS = 19,
+
/* valid in every it_present bitmap, even vendor namespaces */
IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE = 29,
IEEE80211_RADIOTAP_VENDOR_NAMESPACE = 30,
@@ -245,6 +247,24 @@ enum ieee80211_radiotap_type {
#define IEEE80211_RADIOTAP_F_TX_CTS 0x0002 /* used cts 'protection' */
#define IEEE80211_RADIOTAP_F_TX_RTS 0x0004 /* used rts/cts handshake */
+
+/* For IEEE80211_RADIOTAP_MCS */
+#define IEEE80211_RADIOTAP_MCS_HAVE_BW 0x01
+#define IEEE80211_RADIOTAP_MCS_HAVE_MCS 0x02
+#define IEEE80211_RADIOTAP_MCS_HAVE_GI 0x04
+#define IEEE80211_RADIOTAP_MCS_HAVE_FMT 0x08
+#define IEEE80211_RADIOTAP_MCS_HAVE_FEC 0x10
+
+#define IEEE80211_RADIOTAP_MCS_BW_MASK 0x03
+#define IEEE80211_RADIOTAP_MCS_BW_20 0
+#define IEEE80211_RADIOTAP_MCS_BW_40 1
+#define IEEE80211_RADIOTAP_MCS_BW_20L 2
+#define IEEE80211_RADIOTAP_MCS_BW_20U 3
+#define IEEE80211_RADIOTAP_MCS_SGI 0x04
+#define IEEE80211_RADIOTAP_MCS_FMT_GF 0x08
+#define IEEE80211_RADIOTAP_MCS_FEC_LDPC 0x10
+
+
/* Ugly macro to convert literal channel numbers into their mhz equivalents
* There are certianly some conditions that will break this (like feeding it '30')
* but they shouldn't arise since nothing talks on channel 30. */
[-- Attachment #3: 001-radiotap-mcs.patch --]
[-- Type: text/x-patch, Size: 7478 bytes --]
---
epan/dissectors/packet-radiotap-defs.h | 19 ++++++
epan/dissectors/packet-radiotap-iter.c | 4 +
epan/dissectors/packet-radiotap.c | 92 +++++++++++++++++++++++++++++++++
3 files changed, 114 insertions(+), 1 deletion(-)
--- trunk.orig/epan/dissectors/packet-radiotap-defs.h 2010-12-18 18:37:28.000000000 +0100
+++ trunk/epan/dissectors/packet-radiotap-defs.h 2010-12-18 18:37:54.000000000 +0100
@@ -198,6 +198,8 @@ enum ieee80211_radiotap_type {
IEEE80211_RADIOTAP_RTS_RETRIES = 16,
IEEE80211_RADIOTAP_DATA_RETRIES = 17,
+ IEEE80211_RADIOTAP_MCS = 19,
+
/* valid in every it_present bitmap, even vendor namespaces */
IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE = 29,
IEEE80211_RADIOTAP_VENDOR_NAMESPACE = 30,
@@ -244,4 +246,21 @@ enum ieee80211_radiotap_type {
#define IEEE80211_RADIOTAP_F_TX_CTS 0x0002 /* used cts 'protection' */
#define IEEE80211_RADIOTAP_F_TX_RTS 0x0004 /* used rts/cts handshake */
+
+/* For IEEE80211_RADIOTAP_MCS */
+#define IEEE80211_RADIOTAP_MCS_HAVE_BW 0x01
+#define IEEE80211_RADIOTAP_MCS_HAVE_MCS 0x02
+#define IEEE80211_RADIOTAP_MCS_HAVE_GI 0x04
+#define IEEE80211_RADIOTAP_MCS_HAVE_FMT 0x08
+#define IEEE80211_RADIOTAP_MCS_HAVE_FEC 0x10
+
+#define IEEE80211_RADIOTAP_MCS_BW_MASK 0x03
+#define IEEE80211_RADIOTAP_MCS_BW_20 0
+#define IEEE80211_RADIOTAP_MCS_BW_40 1
+#define IEEE80211_RADIOTAP_MCS_BW_20L 2
+#define IEEE80211_RADIOTAP_MCS_BW_20U 3
+#define IEEE80211_RADIOTAP_MCS_SGI 0x04
+#define IEEE80211_RADIOTAP_MCS_FMT_GF 0x08
+#define IEEE80211_RADIOTAP_MCS_FEC_LDPC 0x10
+
#endif /* IEEE80211_RADIOTAP_H */
--- trunk.orig/epan/dissectors/packet-radiotap-iter.c 2010-12-18 18:37:28.000000000 +0100
+++ trunk/epan/dissectors/packet-radiotap-iter.c 2010-12-18 18:37:54.000000000 +0100
@@ -48,7 +48,9 @@ static const struct radiotap_align_size
/* [IEEE80211_RADIOTAP_RX_FLAGS] = 14 */ { 2, 2 },
/* [IEEE80211_RADIOTAP_TX_FLAGS] = 15 */ { 2, 2 },
/* [IEEE80211_RADIOTAP_RTS_RETRIES] = 16 */ { 1, 1 },
- /* [IEEE80211_RADIOTAP_DATA_RETRIES] = 17 */ { 1, 1 }
+ /* [IEEE80211_RADIOTAP_DATA_RETRIES] = 17 */ { 1, 1 },
+ /* currently undefined = 18 */ { 0, 0 },
+ /* [IEEE80211_RADIOTAP_MCS] = 19 */ { 1, 3 }
/*
* add more here as they are defined in
* include/net/ieee80211_radiotap.h
--- trunk.orig/epan/dissectors/packet-radiotap.c 2010-12-18 18:37:28.000000000 +0100
+++ trunk/epan/dissectors/packet-radiotap.c 2010-12-18 18:52:52.000000000 +0100
@@ -161,6 +161,12 @@ static int hf_radiotap_ven_oui = -1;
static int hf_radiotap_ven_subns = -1;
static int hf_radiotap_ven_skip = -1;
static int hf_radiotap_ven_data = -1;
+static int hf_radiotap_mcs = -1;
+static int hf_radiotap_mcs_bw = -1;
+static int hf_radiotap_mcs_index = -1;
+static int hf_radiotap_mcs_gi = -1;
+static int hf_radiotap_mcs_format = -1;
+static int hf_radiotap_mcs_fec = -1;
/* "Present" flags */
static int hf_radiotap_present_tsft = -1;
@@ -180,6 +186,7 @@ static int hf_radiotap_present_db_antnoi
static int hf_radiotap_present_hdrfcs = -1;
static int hf_radiotap_present_rxflags = -1;
static int hf_radiotap_present_xchannel = -1;
+static int hf_radiotap_present_mcs = -1;
static int hf_radiotap_present_rtap_ns = -1;
static int hf_radiotap_present_vendor_ns = -1;
static int hf_radiotap_present_ext = -1;
@@ -206,6 +213,7 @@ static gint ett_radiotap_rxflags = -1;
static gint ett_radiotap_channel_flags = -1;
static gint ett_radiotap_xchannel_flags = -1;
static gint ett_radiotap_vendor = -1;
+static gint ett_radiotap_mcs = -1;
static dissector_handle_t ieee80211_handle;
static dissector_handle_t ieee80211_datapad_handle;
@@ -355,6 +363,28 @@ void proto_register_radiotap(void)
{0, NULL},
};
+ static const value_string mcs_bandwidth[] = {
+ { IEEE80211_RADIOTAP_MCS_BW_20, "20 MHz" },
+ { IEEE80211_RADIOTAP_MCS_BW_40, "40 MHz" },
+ { IEEE80211_RADIOTAP_MCS_BW_20L, "20 MHz lower" },
+ { IEEE80211_RADIOTAP_MCS_BW_20U, "20 MHz upper" },
+ };
+
+ static const value_string mcs_format[] = {
+ { 0, "mixed" },
+ { 1, "greenfield" },
+ };
+
+ static const value_string mcs_fec[] = {
+ { 0, "BCC" },
+ { 1, "LDPC" },
+ };
+
+ static const value_string mcs_gi[] = {
+ { 0, "long" },
+ { 1, "short" },
+ };
+
static const true_false_string preamble_type = {
"Short",
"Long",
@@ -479,6 +509,11 @@ void proto_register_radiotap(void)
"Specifies if the extended channel info field is present",
HFILL}},
+ {&hf_radiotap_present_mcs,
+ {"HT information", "radiotap.present.mcs",
+ FT_BOOLEAN, 32, NULL, RADIOTAP_MASK(MCS),
+ "Specifies if the HT field is present", HFILL}},
+
{&hf_radiotap_present_rtap_ns,
{"Radiotap NS next", "radiotap.present.rtap_ns",
FT_BOOLEAN, 32, NULL, RADIOTAP_MASK(RADIOTAP_NAMESPACE),
@@ -779,6 +814,29 @@ void proto_register_radiotap(void)
FT_INT32, BASE_DEC, NULL, 0x0,
"Transmit power in decibels per one milliwatt (dBm)", HFILL}},
+ {&hf_radiotap_mcs,
+ {"MCS information", "radiotap.mcs",
+ FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
+ {&hf_radiotap_mcs_bw,
+ {"bandwidth", "radiotap.mcs.bw",
+ FT_UINT8, BASE_DEC, VALS(mcs_bandwidth),
+ IEEE80211_RADIOTAP_MCS_BW_MASK, NULL, HFILL}},
+ {&hf_radiotap_mcs_gi,
+ {"guard interval", "radiotap.mcs.gi",
+ FT_UINT8, BASE_DEC, VALS(mcs_gi), IEEE80211_RADIOTAP_MCS_SGI,
+ "Sent/Received guard interval", HFILL}},
+ {&hf_radiotap_mcs_format,
+ {"format", "radiotap.mcs.format",
+ FT_UINT8, BASE_DEC, VALS(mcs_format), IEEE80211_RADIOTAP_MCS_FMT_GF,
+ "format", HFILL}},
+ {&hf_radiotap_mcs_fec,
+ {"FEC", "radiotap.mcs.fec",
+ FT_UINT8, BASE_DEC, VALS(mcs_fec), IEEE80211_RADIOTAP_MCS_FEC_LDPC,
+ "forward error correction", HFILL}},
+ {&hf_radiotap_mcs_index,
+ {"MCS index", "radiotap.mcs.index",
+ FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
+
{&hf_radiotap_vendor_ns,
{"Vendor namespace", "radiotap.vendor_namespace",
FT_BYTES, BASE_NONE, NULL, 0x0,
@@ -820,6 +878,7 @@ void proto_register_radiotap(void)
&ett_radiotap_channel_flags,
&ett_radiotap_xchannel_flags,
&ett_radiotap_vendor,
+ &ett_radiotap_mcs,
};
module_t *radiotap_module;
@@ -1420,6 +1479,39 @@ dissect_radiotap(tvbuff_t * tvb, packet_
}
break;
}
+ case IEEE80211_RADIOTAP_MCS: {
+ proto_item *it;
+ proto_tree *mcs_tree;
+ guint8 mcs_known, mcs_flags;
+ guint8 mcs;
+
+ if (!tree)
+ break;
+
+ mcs_known = tvb_get_guint8(tvb, offset);
+ mcs_flags = tvb_get_guint8(tvb, offset + 1);
+ mcs = tvb_get_guint8(tvb, offset + 2);
+
+ it = proto_tree_add_item(radiotap_tree, hf_radiotap_mcs,
+ tvb, offset, 3, FALSE);
+ mcs_tree = proto_item_add_subtree(it, ett_radiotap_mcs);
+ if (mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_BW)
+ proto_tree_add_uint(mcs_tree, hf_radiotap_mcs_bw,
+ tvb, offset + 1, 1, mcs_flags);
+ if (mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_GI)
+ proto_tree_add_uint(mcs_tree, hf_radiotap_mcs_gi,
+ tvb, offset + 1, 1, mcs_flags);
+ if (mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_FMT)
+ proto_tree_add_uint(mcs_tree, hf_radiotap_mcs_format,
+ tvb, offset + 1, 1, mcs_flags);
+ if (mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_FEC)
+ proto_tree_add_uint(mcs_tree, hf_radiotap_mcs_fec,
+ tvb, offset + 1, 1, mcs_flags);
+ if (mcs_known & IEEE80211_RADIOTAP_MCS_HAVE_MCS)
+ proto_tree_add_uint(mcs_tree, hf_radiotap_mcs_index,
+ tvb, offset + 2, 1, mcs);
+ break;
+ }
}
}
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFA] MCS extension
[not found] ` <1292694998.3653.33.camel-8upI4CBIZJIJvtFkdXX2HixXY32XiHfO@public.gmane.org>
@ 2011-01-21 10:08 ` Johannes Berg
[not found] ` <1295604481.3831.1.camel-8upI4CBIZJIJvtFkdXX2HixXY32XiHfO@public.gmane.org>
0 siblings, 1 reply; 4+ messages in thread
From: Johannes Berg @ 2011-01-21 10:08 UTC (permalink / raw)
To: Radiotap
On Sat, 2010-12-18 at 18:56 +0100, Johannes Berg wrote:
> This is a request for adoption of a new version of the MCS extension.
> I've split out the aMPDU extension since that seems more natural.
>
> The MCS extension allows giving MCS information about a frame.
Any notes on this? Nobody objecting to the split between MCS and a-MPDU
that I now did? :-)
johannes
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFA] MCS extension
[not found] ` <1295604481.3831.1.camel-8upI4CBIZJIJvtFkdXX2HixXY32XiHfO@public.gmane.org>
@ 2011-01-21 16:41 ` David Young
[not found] ` <20110121164137.GD24244-eZodSLrBbDpBDgjK7y7TUQ@public.gmane.org>
0 siblings, 1 reply; 4+ messages in thread
From: David Young @ 2011-01-21 16:41 UTC (permalink / raw)
To: Radiotap
On Fri, Jan 21, 2011 at 11:08:01AM +0100, Johannes Berg wrote:
> On Sat, 2010-12-18 at 18:56 +0100, Johannes Berg wrote:
> > This is a request for adoption of a new version of the MCS extension.
> > I've split out the aMPDU extension since that seems more natural.
> >
> > The MCS extension allows giving MCS information about a frame.
>
> Any notes on this? Nobody objecting to the split between MCS and a-MPDU
> that I now did? :-)
Thanks for the reminder. Radiotap emails keep slipping over my email
horizon. :-/
Looks good to me. Thanks for doing this.
Dave
--
David Young OJC Technologies
dyoung-eZodSLrBbDpBDgjK7y7TUQ@public.gmane.org Urbana, IL * (217) 278-3933
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFA] MCS extension
[not found] ` <20110121164137.GD24244-eZodSLrBbDpBDgjK7y7TUQ@public.gmane.org>
@ 2011-01-27 13:09 ` Johannes Berg
0 siblings, 0 replies; 4+ messages in thread
From: Johannes Berg @ 2011-01-27 13:09 UTC (permalink / raw)
To: Radiotap
On Fri, 2011-01-21 at 10:41 -0600, David Young wrote:
> On Fri, Jan 21, 2011 at 11:08:01AM +0100, Johannes Berg wrote:
> > On Sat, 2010-12-18 at 18:56 +0100, Johannes Berg wrote:
> > > This is a request for adoption of a new version of the MCS extension.
> > > I've split out the aMPDU extension since that seems more natural.
> > >
> > > The MCS extension allows giving MCS information about a frame.
> >
> > Any notes on this? Nobody objecting to the split between MCS and a-MPDU
> > that I now did? :-)
>
> Thanks for the reminder. Radiotap emails keep slipping over my email
> horizon. :-/
>
> Looks good to me. Thanks for doing this.
Thanks for looking, I got behind too. I've made the corresponding wiki
change now, and will go ahead and submit the patches I'd done.
Thanks! A-MPDU is next, and maybe those TX flags and retry things.
johannes
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-01-27 13:09 UTC | newest]
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2010-12-18 17:56 [RFA] MCS extension Johannes Berg
[not found] ` <1292694998.3653.33.camel-8upI4CBIZJIJvtFkdXX2HixXY32XiHfO@public.gmane.org>
2011-01-21 10:08 ` Johannes Berg
[not found] ` <1295604481.3831.1.camel-8upI4CBIZJIJvtFkdXX2HixXY32XiHfO@public.gmane.org>
2011-01-21 16:41 ` David Young
[not found] ` <20110121164137.GD24244-eZodSLrBbDpBDgjK7y7TUQ@public.gmane.org>
2011-01-27 13:09 ` Johannes Berg
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