docs: networking: convert radiotap-headers.txt to ReST

- add SPDX header;
- adjust title markup;
- mark code blocks and literals as such;
- adjust identation, whitespaces and blank lines where needed;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mauro Carvalho Chehab 2020-04-30 18:04:17 +02:00 committed by David S. Miller
parent 832619012c
commit 66d495d0a5
5 changed files with 57 additions and 49 deletions

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@ -95,6 +95,7 @@ Contents:
plip
ppp_generic
proc_net_tcp
radiotap-headers
.. only:: subproject and html

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@ -13,7 +13,7 @@ following format::
[ payload ]
The radiotap format is discussed in
./Documentation/networking/radiotap-headers.txt.
./Documentation/networking/radiotap-headers.rst.
Despite many radiotap parameters being currently defined, most only make sense
to appear on received packets. The following information is parsed from the

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@ -1,3 +1,6 @@
.. SPDX-License-Identifier: GPL-2.0
===========================
How to use radiotap headers
===========================
@ -5,9 +8,9 @@ Pointer to the radiotap include file
------------------------------------
Radiotap headers are variable-length and extensible, you can get most of the
information you need to know on them from:
information you need to know on them from::
./include/net/ieee80211_radiotap.h
./include/net/ieee80211_radiotap.h
This document gives an overview and warns on some corner cases.
@ -21,6 +24,8 @@ of the it_present member of ieee80211_radiotap_header is set, it means that
the header for argument index 0 (IEEE80211_RADIOTAP_TSFT) is present in the
argument area.
::
< 8-byte ieee80211_radiotap_header >
[ <possible argument bitmap extensions ... > ]
[ <argument> ... ]
@ -76,6 +81,8 @@ ieee80211_radiotap_header.
Example valid radiotap header
-----------------------------
::
0x00, 0x00, // <-- radiotap version + pad byte
0x0b, 0x00, // <- radiotap header length
0x04, 0x0c, 0x00, 0x00, // <-- bitmap
@ -89,64 +96,64 @@ Using the Radiotap Parser
If you are having to parse a radiotap struct, you can radically simplify the
job by using the radiotap parser that lives in net/wireless/radiotap.c and has
its prototypes available in include/net/cfg80211.h. You use it like this:
its prototypes available in include/net/cfg80211.h. You use it like this::
#include <net/cfg80211.h>
#include <net/cfg80211.h>
/* buf points to the start of the radiotap header part */
/* buf points to the start of the radiotap header part */
int MyFunction(u8 * buf, int buflen)
{
int pkt_rate_100kHz = 0, antenna = 0, pwr = 0;
struct ieee80211_radiotap_iterator iterator;
int ret = ieee80211_radiotap_iterator_init(&iterator, buf, buflen);
int MyFunction(u8 * buf, int buflen)
{
int pkt_rate_100kHz = 0, antenna = 0, pwr = 0;
struct ieee80211_radiotap_iterator iterator;
int ret = ieee80211_radiotap_iterator_init(&iterator, buf, buflen);
while (!ret) {
while (!ret) {
ret = ieee80211_radiotap_iterator_next(&iterator);
ret = ieee80211_radiotap_iterator_next(&iterator);
if (ret)
continue;
if (ret)
continue;
/* see if this argument is something we can use */
/* 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_RATE:
/* radiotap "rate" u8 is in
* 500kbps units, eg, 0x02=1Mbps
*/
pkt_rate_100kHz = (*iterator.this_arg) * 5;
break;
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_RATE:
/* radiotap "rate" u8 is in
* 500kbps units, eg, 0x02=1Mbps
*/
pkt_rate_100kHz = (*iterator.this_arg) * 5;
break;
case IEEE80211_RADIOTAP_ANTENNA:
/* radiotap uses 0 for 1st ant */
antenna = *iterator.this_arg);
break;
case IEEE80211_RADIOTAP_ANTENNA:
/* radiotap uses 0 for 1st ant */
antenna = *iterator.this_arg);
break;
case IEEE80211_RADIOTAP_DBM_TX_POWER:
pwr = *iterator.this_arg;
break;
case IEEE80211_RADIOTAP_DBM_TX_POWER:
pwr = *iterator.this_arg;
break;
default:
break;
}
} /* while more rt headers */
default:
break;
}
} /* while more rt headers */
if (ret != -ENOENT)
return TXRX_DROP;
if (ret != -ENOENT)
return TXRX_DROP;
/* discard the radiotap header part */
buf += iterator.max_length;
buflen -= iterator.max_length;
/* discard the radiotap header part */
buf += iterator.max_length;
buflen -= iterator.max_length;
...
...
}
}
Andy Green <andy@warmcat.com>

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@ -5211,7 +5211,7 @@ u32 ieee80211_mandatory_rates(struct ieee80211_supported_band *sband,
* Radiotap parsing functions -- for controlled injection support
*
* Implemented in net/wireless/radiotap.c
* Documentation in Documentation/networking/radiotap-headers.txt
* Documentation in Documentation/networking/radiotap-headers.rst
*/
struct radiotap_align_size {

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@ -90,7 +90,7 @@ static const struct ieee80211_radiotap_namespace radiotap_ns = {
* iterator.this_arg for type "type" safely on all arches.
*
* Example code:
* See Documentation/networking/radiotap-headers.txt
* See Documentation/networking/radiotap-headers.rst
*/
int ieee80211_radiotap_iterator_init(