iw: Add support for NL80211_ATTR_WIPHY_COVERAGE_CLASS

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@praha12.net>

diff --git a/info.c b/info.c
index 69af2164f81af49ef7020debb12a2f474c0d5448..1a1b5883e0cef3d56312d1d3bdf0bfe04641ff54 100644 (file)
--- 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/phy.c b/phy.c
index 8dd01aaab47085d0e8864b13531e60f4dc951b24..5a87024c0fef622da972a931f151d543bc86d8ce 100644 (file)
--- 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");