[PATCH] iw: Add support for controlling tx power for per station

[PATCH] iw: Add support for controlling tx power for per station

[Balaji Pothunoori]

From: Ashok Raj Nagarajan <arnagara@codeaurora.org>

This patch allows userspace to set transmit power,
in mBm units, to a station associated to the AP.

To set a limit tx power of 2000 mBm:
iw wlan0 station set <mac-addr> txpwr limit 2000

To revert the user defined tx power for a station:
iw wlan0 station set <mac-addr> txpwr auto

iCo-developed-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Ashok Raj Nagarajan <arnagara@codeaurora.org>
Signed-off-by: Balaji Pothunoori <bpothuno@codeaurora.org>
---
 station.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/station.c b/station.c
index e1477ef..3cce617 100644
--- a/station.c
+++ b/station.c
@@ -651,6 +651,7 @@ COMMAND(station, del, "<MAC address> [subtype <subtype>] [reason-code <code>]",
 static const struct cmd *station_set_plink;
 static const struct cmd *station_set_vlan;
 static const struct cmd *station_set_mesh_power_mode;
+static const struct cmd *station_set_txpwr;
 
 static const struct cmd *select_station_cmd(int argc, char **argv)
 {
@@ -662,6 +663,8 @@ static const struct cmd *select_station_cmd(int argc, char **argv)
 		return station_set_vlan;
 	if (strcmp(argv[1], "mesh_power_mode") == 0)
 		return station_set_mesh_power_mode;
+	if (strcmp(argv[1], "txpwr") == 0)
+		return station_set_txpwr;
 	return NULL;
 }
 
@@ -813,6 +816,74 @@ COMMAND_ALIAS(station, set, "<MAC address> mesh_power_mode "
 	"Set link-specific mesh power mode for this station",
 	select_station_cmd, station_set_mesh_power_mode);
 
+static int handle_station_set_txpwr(struct nl80211_state *state,
+				    struct nl_msg *msg,
+				    int argc, char **argv,
+				    enum id_input id)
+{
+	enum nl80211_tx_power_setting type;
+	unsigned char mac_addr[ETH_ALEN];
+	unsigned int sta_txpwr = 0;
+	char *err = NULL;
+
+	if (argc != 3 && argc != 4)
+		return 1;
+
+	if (mac_addr_a2n(mac_addr, argv[0])) {
+		fprintf(stderr, "invalid mac address\n");
+		return 2;
+	}
+
+	NLA_PUT(msg, NL80211_ATTR_MAC, ETH_ALEN, mac_addr);
+	argc--;
+	argv++;
+
+	if (strcmp("txpwr", argv[0]) != 0)
+		return 1;
+	argc--;
+	argv++;
+
+	if (!strcmp(argv[0], "auto"))
+		type = NL80211_TX_POWER_AUTOMATIC;
+	else if (!strcmp(argv[0], "limit"))
+		type = NL80211_TX_POWER_LIMITED;
+	else {
+		printf("Invalid parameter: %s\n", argv[0]);
+		return 2;
+	}
+
+	NLA_PUT_U32(msg, NL80211_ATTR_STA_TX_POWER_SETTING, type);
+
+	if (type != NL80211_TX_POWER_AUTOMATIC) {
+		if (argc != 2) {
+			printf("Missing TX power level argument.\n");
+			return 2;
+		}
+
+		argc--;
+		argv++;
+
+		sta_txpwr = strtoul(argv[0], &err, 0);
+
+		if (sta_txpwr)
+		NLA_PUT_U32(msg, NL80211_ATTR_STA_TX_POWER, sta_txpwr);
+	}
+
+	argc--;
+	argv++;
+
+	if (argc)
+		return 1;
+
+	return 0;
+ nla_put_failure:
+	return -ENOBUFS;
+}
+COMMAND_ALIAS(station, set, "<MAC address> txpwr <auto|limit> [<tx power mBm>]",
+	NL80211_CMD_SET_STATION, 0, CIB_NETDEV, handle_station_set_txpwr,
+	"Set Tx power for this station.",
+	select_station_cmd, station_set_txpwr);
+
 static int handle_station_dump(struct nl80211_state *state,
 			       struct nl_msg *msg,
 			       int argc, char **argv,
-- 
2.7.4

Re: [PATCH] iw: Add support for controlling tx power for per station

[Johannes Berg]

On Thu, 2019-01-17 at 18:59 +0530, Balaji Pothunoori wrote:
> From: Ashok Raj Nagarajan <arnagara@codeaurora.org>
> 
> This patch allows userspace to set transmit power,
> in mBm units, to a station associated to the AP.
> 
> To set a limit tx power of 2000 mBm:
> iw wlan0 station set <mac-addr> txpwr limit 2000

I would prefer if this was *dBm*, rather than mBm, and be allowed to
take float values, i.e. this would become "limit 20".

johannes

Re: [PATCH] iw: Add support for controlling tx power for per station

[Balaji Pothunoori]

On 2019-01-25 18:05, Johannes Berg wrote:
> On Thu, 2019-01-17 at 18:59 +0530, Balaji Pothunoori wrote:
>> From: Ashok Raj Nagarajan <arnagara@codeaurora.org>
>> 
>> This patch allows userspace to set transmit power,
>> in mBm units, to a station associated to the AP.
>> 
>> To set a limit tx power of 2000 mBm:
>> iw wlan0 station set <mac-addr> txpwr limit 2000
> 
> I would prefer if this was *dBm*, rather than mBm, and be allowed to
> take float values, i.e. this would become "limit 20".
> 
> johannes

Johannes,

Curiously asking, existing txpower set for vap/phy interface will in mBm 
from user space.
why would you suggesting dBm for per peer txpower set?

Existing designs :
root@OpenWrt:~# iw | grep power
         dev <devname> set txpower <auto|fixed|limit> [<tx power in mBm>]
         phy <phyname> set txpower <auto|fixed|limit> [<tx power in mBm>]

Regards,
Balaji.

Re: [PATCH] iw: Add support for controlling tx power for per station

[Johannes Berg]

On Tue, 2019-01-29 at 17:55 +0530, Balaji Pothunoori wrote:
> 
> Curiously asking, existing txpower set for vap/phy interface will in mBm 
> from user space.
> why would you suggesting dBm for per peer txpower set?

Yeah :-(

I basically think it's a mistake. I don't know if we can fix it now
though.

johannes

[PATCH] iw: Add support for controlling tx power for per station

[Ashok Raj Nagarajan]

This patch allows userspace to set transmit power, in mBm units, to a
station associated to the AP.

To set a limit tx power of 2000 mBm:
iw wlan0 station set <mac-addr> txpwr limit 2000

To revert the user defined tx power for a station:
iw wlan0 station set <mac-addr> txpwr auto

Signed-off-by: Ashok Raj Nagarajan <arnagara@qti.qualcomm.com>
---
 station.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 69 insertions(+)

diff --git a/station.c b/station.c
index f3e3da8..8364593 100644
--- a/station.c
+++ b/station.c
@@ -569,6 +569,7 @@ COMMAND(station, del, "<MAC address> [subtype <subtype>] [reason-code <code>]",
 static const struct cmd *station_set_plink;
 static const struct cmd *station_set_vlan;
 static const struct cmd *station_set_mesh_power_mode;
+static const struct cmd *station_set_txpwr;
 
 static const struct cmd *select_station_cmd(int argc, char **argv)
 {
@@ -580,6 +581,8 @@ static const struct cmd *select_station_cmd(int argc, char **argv)
 		return station_set_vlan;
 	if (strcmp(argv[1], "mesh_power_mode") == 0)
 		return station_set_mesh_power_mode;
+	if (strcmp(argv[1], "txpwr") == 0)
+		return station_set_txpwr;
 	return NULL;
 }
 
@@ -731,6 +734,72 @@ COMMAND_ALIAS(station, set, "<MAC address> mesh_power_mode "
 	"Set link-specific mesh power mode for this station",
 	select_station_cmd, station_set_mesh_power_mode);
 
+static int handle_station_set_txpwr(struct nl80211_state *state,
+				    struct nl_msg *msg,
+				    int argc, char **argv,
+				    enum id_input id)
+{
+	enum nl80211_tx_power_setting type;
+	unsigned char mac_addr[ETH_ALEN];
+	unsigned int sta_txpwr = 0;
+	char *err = NULL;
+
+	if (argc != 3 && argc != 4)
+		return 1;
+
+	if (mac_addr_a2n(mac_addr, argv[0])) {
+		fprintf(stderr, "invalid mac address\n");
+		return 2;
+	}
+
+	NLA_PUT(msg, NL80211_ATTR_MAC, ETH_ALEN, mac_addr);
+	argc--;
+	argv++;
+
+	if (strcmp("txpwr", argv[0]) != 0)
+		return 1;
+	argc--;
+	argv++;
+
+	if (!strcmp(argv[0], "auto"))
+		type = NL80211_TX_POWER_AUTOMATIC;
+	else if (!strcmp(argv[0], "limit"))
+		type = NL80211_TX_POWER_LIMITED;
+	else {
+		printf("Invalid parameter: %s\n", argv[0]);
+		return 2;
+	}
+
+	NLA_PUT_U32(msg, NL80211_ATTR_STA_TX_POWER_SETTING, type);
+
+	if (type != NL80211_TX_POWER_AUTOMATIC) {
+		if (argc != 2) {
+			printf("Missing TX power level argument.\n");
+			return 2;
+		}
+
+		argc--;
+		argv++;
+
+		sta_txpwr = strtoul(argv[0], &err, 0);
+		NLA_PUT_U32(msg, NL80211_ATTR_STA_TX_POWER, sta_txpwr);
+	}
+
+	argc--;
+	argv++;
+
+	if (argc)
+		return 1;
+
+	return 0;
+ nla_put_failure:
+	return -ENOBUFS;
+}
+COMMAND_ALIAS(station, set, "<MAC address> txpwr <auto|limit> [<tx power mBm>]",
+	NL80211_CMD_SET_STATION, 0, CIB_NETDEV, handle_station_set_txpwr,
+	"Set Tx power for this station.",
+	select_station_cmd, station_set_txpwr);
+
 static int handle_station_dump(struct nl80211_state *state,
 			       struct nl_msg *msg,
 			       int argc, char **argv,
-- 
1.9.1