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>

1 files changed, 49 insertions, 0 deletions

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: