[PATCH] iw: Add support for NL80211_ATTR_WIPHY_COVERAGE_CLASS

From: Luis R. Rodriguez
Date: Wed Feb 17 2010 - 20:42:52 EST


From: LukÃÅ Turek <8an@xxxxxxxxxxx>

New nl80211 attribute NL80211_ATTR_WIPHY_COVERAGE_CLASS allows setting
IEEE 802.11 coverage class, which is then used by drivers to calculate
slot time and ACK timeout for long distance links.

Two iw parameters are added: 'coverage' sets the coverage class
directly, while 'distance' is more user-friendly, as it allows to set
just the link distance and let iw do the necessary calculation itself.

Signed-off-by: Lukas Turek <8an@xxxxxxxxxxx>
---
info.c | 8 ++++++++
nl80211.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++--
phy.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 113 insertions(+), 2 deletions(-)

diff --git a/info.c b/info.c
index 69af216..1a1b588 100644
--- a/info.c
+++ b/info.c
@@ -156,6 +156,14 @@ static int print_phy_handler(struct nl_msg *msg, void *arg)
printf("\tRTS threshold: %d\n", rts);
}

+ if (tb_msg[NL80211_ATTR_WIPHY_COVERAGE_CLASS]) {
+ unsigned char coverage;
+
+ coverage = nla_get_u8(tb_msg[NL80211_ATTR_WIPHY_COVERAGE_CLASS]);
+ /* See handle_distance() for an explanation where the '450' comes from */
+ printf("\tCoverage class: %d (up to %dm)\n", coverage, 450 * coverage);
+ }
+
if (!tb_msg[NL80211_ATTR_SUPPORTED_IFTYPES])
goto commands;

diff --git a/nl80211.h b/nl80211.h
index 127a730..43aee23 100644
--- a/nl80211.h
+++ b/nl80211.h
@@ -3,7 +3,7 @@
/*
* 802.11 netlink interface public header
*
- * Copyright 2006, 2007, 2008 Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
+ * Copyright 2006-2010 Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
* Copyright 2008 Michael Wu <flamingice@xxxxxxxxxxxx>
* Copyright 2008 Luis Carlos Cobo <luisca@xxxxxxxxxxx>
* Copyright 2008 Michael Buesch <mb@xxxxxxxxx>
@@ -51,7 +51,7 @@
* %NL80211_ATTR_WIPHY_TXQ_PARAMS, %NL80211_ATTR_WIPHY_FREQ,
* %NL80211_ATTR_WIPHY_CHANNEL_TYPE, %NL80211_ATTR_WIPHY_RETRY_SHORT,
* %NL80211_ATTR_WIPHY_RETRY_LONG, %NL80211_ATTR_WIPHY_FRAG_THRESHOLD,
- * and/or %NL80211_ATTR_WIPHY_RTS_THRESHOLD.
+ * and/or %NL80211_ATTR_WIPHY_RTS_THRESHOLD, %NL80211_ATTR_WIPHY_TXPOWER.
* @NL80211_CMD_NEW_WIPHY: Newly created wiphy, response to get request
* or rename notification. Has attributes %NL80211_ATTR_WIPHY and
* %NL80211_ATTR_WIPHY_NAME.
@@ -299,6 +299,31 @@
* rate selection. %NL80211_ATTR_IFINDEX is used to specify the interface
* and @NL80211_ATTR_TX_RATES the set of allowed rates.
*
+ * @NL80211_CMD_REGISTER_ACTION: Register for receiving certain action frames
+ * (via @NL80211_CMD_ACTION) for processing in userspace. This command
+ * requires an interface index and a match attribute containing the first
+ * few bytes of the frame that should match, e.g. a single byte for only
+ * a category match or four bytes for vendor frames including the OUI.
+ * The registration cannot be dropped, but is removed automatically
+ * when the netlink socket is closed. Multiple registrations can be made.
+ * @NL80211_CMD_ACTION: Action frame TX request and RX notification. This
+ * command is used both as a request to transmit an Action frame and as an
+ * event indicating reception of an Action frame that was not processed in
+ * kernel code, but is for us (i.e., which may need to be processed in a
+ * user space application). %NL80211_ATTR_FRAME is used to specify the
+ * frame contents (including header). %NL80211_ATTR_WIPHY_FREQ (and
+ * optionally %NL80211_ATTR_WIPHY_CHANNEL_TYPE) is used to indicate on
+ * which channel the frame is to be transmitted or was received. This
+ * channel has to be the current channel (remain-on-channel or the
+ * operational channel). When called, this operation returns a cookie
+ * (%NL80211_ATTR_COOKIE) that will be included with the TX status event
+ * pertaining to the TX request.
+ * @NL80211_CMD_ACTION_TX_STATUS: Report TX status of an Action frame
+ * transmitted with %NL80211_CMD_ACTION. %NL80211_ATTR_COOKIE identifies
+ * the TX command and %NL80211_ATTR_FRAME includes the contents of the
+ * frame. %NL80211_ATTR_ACK flag is included if the recipient acknowledged
+ * the frame.
+ *
* @NL80211_CMD_MAX: highest used command number
* @__NL80211_CMD_AFTER_LAST: internal use
*/
@@ -387,6 +412,10 @@ enum nl80211_commands {

NL80211_CMD_SET_TX_BITRATE_MASK,

+ NL80211_CMD_REGISTER_ACTION,
+ NL80211_CMD_ACTION,
+ NL80211_CMD_ACTION_TX_STATUS,
+
/* add new commands above here */

/* used to define NL80211_CMD_MAX below */
@@ -653,6 +682,15 @@ enum nl80211_commands {
* rates based on negotiated supported rates information. This attribute
* is used with %NL80211_CMD_SET_TX_BITRATE_MASK.
*
+ * @NL80211_ATTR_FRAME_MATCH: A binary attribute which typically must contain
+ * at least one byte, currently used with @NL80211_CMD_REGISTER_ACTION.
+ *
+ * @NL80211_ATTR_ACK: Flag attribute indicating that the frame was
+ * acknowledged by the recipient.
+ *
+ * @NL80211_ATTR_WIPHY_TXPOWER: Target output power, specified in mBm ((100 * dBm) as
+ * some hardware allows finer granular power control than 1 dBm steps.
+ *
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
*/
@@ -798,6 +836,12 @@ enum nl80211_attrs {

NL80211_ATTR_TX_RATES,

+ NL80211_ATTR_FRAME_MATCH,
+
+ NL80211_ATTR_ACK,
+
+ NL80211_ATTR_WIPHY_TXPOWER,
+
/* add attributes here, update the policy in nl80211.c */

__NL80211_ATTR_AFTER_LAST,
@@ -831,6 +875,7 @@ enum nl80211_attrs {
#define NL80211_ATTR_AKM_SUITES NL80211_ATTR_AKM_SUITES
#define NL80211_ATTR_KEY NL80211_ATTR_KEY
#define NL80211_ATTR_KEYS NL80211_ATTR_KEYS
+#define NL80211_ATTR_WIPHY_TXPOWER NL80211_ATTR_WIPHY_TXPOWER

#define NL80211_MAX_SUPP_RATES 32
#define NL80211_MAX_SUPP_REG_RULES 32
diff --git a/phy.c b/phy.c
index 8dd01aa..5a87024 100644
--- a/phy.c
+++ b/phy.c
@@ -164,3 +164,61 @@ static int handle_netns(struct nl80211_state *state,
COMMAND(set, netns, "<pid>",
NL80211_CMD_SET_WIPHY_NETNS, 0, CIB_PHY, handle_netns,
"Put this wireless device into a different network namespace");
+
+static int handle_coverage(struct nl80211_state *state,
+ struct nl_cb *cb,
+ struct nl_msg *msg,
+ int argc, char **argv)
+{
+ unsigned int coverage;
+
+ if (argc != 1)
+ return 1;
+
+ coverage = strtoul(argv[0], NULL, 10);
+ if (coverage > 255)
+ return 1;
+
+ NLA_PUT_U8(msg, NL80211_ATTR_WIPHY_COVERAGE_CLASS, coverage);
+
+ return 0;
+ nla_put_failure:
+ return -ENOBUFS;
+}
+COMMAND(set, coverage, "<coverage class>",
+ NL80211_CMD_SET_WIPHY, 0, CIB_PHY, handle_coverage,
+ "Set coverage class (1 for every 3 usec of air propagation time).\n"
+ "Valid values: 0 - 255.");
+
+static int handle_distance(struct nl80211_state *state,
+ struct nl_cb *cb,
+ struct nl_msg *msg,
+ int argc, char **argv)
+{
+ unsigned int distance, coverage;
+
+ if (argc != 1)
+ return 1;
+
+ distance = strtoul(argv[0], NULL, 10);
+
+ /*
+ * Divide double the distance by the speed of light in m/usec (300) to
+ * get round-trip time in microseconds and then divide the result by
+ * three to get coverage class as specified in IEEE 802.11-2007 table
+ * 7-27. Values are rounded upwards.
+ */
+ coverage = (distance + 449) / 450;
+ if (coverage > 255)
+ return 1;
+
+ NLA_PUT_U8(msg, NL80211_ATTR_WIPHY_COVERAGE_CLASS, coverage);
+
+ return 0;
+ nla_put_failure:
+ return -ENOBUFS;
+}
+COMMAND(set, distance, "<distance>",
+ NL80211_CMD_SET_WIPHY, 0, CIB_PHY, handle_distance,
+ "Set appropriate coverage class for given link distance in meters.\n"
+ "Valid values: 0 - 114750");
--
1.6.3.3

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