mac80211: Set basic rates while joining ibss network

This patch adds support to nl80211 and mac80211 to set basic rates when
joining/creating ibss network.

Original patch was posted by Johannes Berg on the linux-wireless posting list.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 54 insertions, 1 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index bfd7286488c7..9f4e64ed8b83 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -172,6 +172,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
         rcu_assign_pointer(ifibss->presp, skb);
 
         sdata->vif.bss_conf.beacon_int = beacon_int;
+        sdata->vif.bss_conf.basic_rates = basic_rates;
         bss_change = BSS_CHANGED_BEACON_INT;
         bss_change |= ieee80211_reset_erp_info(sdata);
         bss_change |= BSS_CHANGED_BSSID;
@@ -529,7 +530,7 @@ static void ieee80211_sta_create_ibss(struct ieee80211_sub_if_data *sdata)
                 sdata->drop_unencrypted = 0;
 
         __ieee80211_sta_join_ibss(sdata, bssid, sdata->vif.bss_conf.beacon_int,
-                                  ifibss->channel, 3, /* first two are basic */
+                                  ifibss->channel, ifibss->basic_rates,
                                   capability, 0);
 }
 
@@ -859,6 +860,7 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
                 sdata->u.ibss.fixed_bssid = false;
 
         sdata->u.ibss.privacy = params->privacy;
+        sdata->u.ibss.basic_rates = params->basic_rates;
 
         sdata->vif.bss_conf.beacon_int = params->beacon_interval;
 
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 9d753a02a2e4..c3c2be3f8a2c 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -387,6 +387,8 @@ struct ieee80211_if_ibss {
         unsigned long request;
         unsigned long last_scan_completed;
 
+        u32 basic_rates;
+
         bool timer_running;
 
         bool fixed_bssid;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index c65e67e9231c..41529aca794c 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -3955,6 +3955,55 @@ static int nl80211_join_ibss(struct sk_buff *skb, struct genl_info *info)
                 }
         }
 
+        if (info->attrs[NL80211_ATTR_BSS_BASIC_RATES]) {
+                u8 *rates =
+                        nla_data(info->attrs[NL80211_ATTR_BSS_BASIC_RATES]);
+                int n_rates =
+                        nla_len(info->attrs[NL80211_ATTR_BSS_BASIC_RATES]);
+                struct ieee80211_supported_band *sband =
+                        wiphy->bands[ibss.channel->band];
+                int i, j;
+
+                if (n_rates == 0) {
+                        err = -EINVAL;
+                        goto out;
+                }
+
+                for (i = 0; i < n_rates; i++) {
+                        int rate = (rates[i] & 0x7f) * 5;
+                        bool found = false;
+
+                        for (j = 0; j < sband->n_bitrates; j++) {
+                                if (sband->bitrates[j].bitrate == rate) {
+                                        found = true;
+                                        ibss.basic_rates |= BIT(j);
+                                        break;
+                                }
+                        }
+                        if (!found) {
+                                err = -EINVAL;
+                                goto out;
+                        }
+                }
+        } else {
+                /*
+                * If no rates were explicitly configured,
+                * use the mandatory rate set for 11b or
+                * 11a for maximum compatibility.
+                */
+                struct ieee80211_supported_band *sband =
+                        wiphy->bands[ibss.channel->band];
+                int j;
+                u32 flag = ibss.channel->band == IEEE80211_BAND_5GHZ ?
+                        IEEE80211_RATE_MANDATORY_A :
+                        IEEE80211_RATE_MANDATORY_B;
+
+                for (j = 0; j < sband->n_bitrates; j++) {
+                        if (sband->bitrates[j].flags & flag)
+                                ibss.basic_rates |= BIT(j);
+                }
+        }
+
         err = cfg80211_join_ibss(rdev, dev, &ibss, connkeys);
 
 out: