iw: Add support for controlling tx power for per station

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

To set a limit tx power of 20 dBm:
iw wlan0 station set <mac-addr> txpwr limit 20

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

Co-developed-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Ashok Raj Nagarajan <arnagara@codeaurora.org>
Signed-off-by: Balaji Pothunoori <bpothuno@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/station.c b/station.c
index 25cbbc3784496f8f5f91892091a88b3f0a8601a0..0454f878e69093501024f3a6fc7f1b453a8e7250 100644 (file)
--- a/station.c
+++ b/station.c
@@ -661,6 +661,7 @@ 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_airtime_weight;
+static const struct cmd *station_set_txpwr;
 
 static const struct cmd *select_station_cmd(int argc, char **argv)
 {
@@ -674,6 +675,8 @@ static const struct cmd *select_station_cmd(int argc, char **argv)
                return station_set_mesh_power_mode;
        if (strcmp(argv[1], "airtime_weight") == 0)
                return station_set_airtime_weight;
+       if (strcmp(argv[1], "txpwr") == 0)
+               return station_set_txpwr;
        return NULL;
 }
 
@@ -873,6 +876,72 @@ COMMAND_ALIAS(station, set, "<MAC address> airtime_weight <weight>",
        "Set airtime weight for this station.",
        select_station_cmd, station_set_airtime_weight);
 
+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];
+       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_U8(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_U16(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 dBm>]",
+       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,